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my^i, 


Gift 
Dr •Maurice  Heppner 


THE  MEDICAL  STUDENT'S 


MANUAL  OF  CHEMISTRY 


BY 


R.  A.  WITTHAUS,  A.M.,  M.D. 

Professor  of  Ohemistiy.  Physics  and  Toxieolosy  in  Oomell  XJnlvenllar 


Sixtb  £t>ition 


NEW   YORK 
WILLIAM  WOOD   &  COMPANY 

MDCCCriX 


Ck>PTRIOHT,   1906 
Bt  WILLIAM  WOOD  &  COMPANY 


1  -^  ■/ 


PREFACE  TO  THE  PRESENT  EDITION. 

In  the  present  edition  the  section  on  chemical  physics  and  gen* 
eral  chemistry  has  been  entirely  rewritten  so  far  as  it  applies  to  the 
former  branch  of  the  subject,  and  has  been  rearranged  and  extended 
with  regard  to  the  latter.  These  extensions  have  been  necessary  to 
permit  of  proper  consideration  of  the  important  collateral  evidence 
upon  chemical  questions  which  has  been  supplied  by  physical  in- 
vestigations, and  which  now  constitutes  so  important  a  part  of  the 
foundation  of  chemical  principles. 

The  section  on  inorganic  chemistry,  which  had  been  condensed 
to  the  minimum  in  the  last  edition,  has  been  almost  bodily  tran- 
scribed therefrom.  The  main  purpose  of  this  section  is  to  supply 
certain  data  which  shall  serve  as  the  text  upon  which  to  discuss  the 
general  principles  of  chemistry.  It  is  the  opinion  of  the  author 
that  the  object  of  chemical  teaching  (except  to  advanced  students 
in  the  specialties)  should  not  be  to  lay  up  in  the  memory  of  the 
student  a  store  of  isolated  facts,  but  rather  to  train  his  mind  in  those 
general  principles  by  which  he  may  reason  out  chemical  problems 
for  himself.  If  a  teacher  of  chemistry  to  medical  students  aim 
merely  to  supply  them  with  chemical  facts,  he  and  they  are  fore- 
ordained to  disappointment,  but  if  the  student  be  led  to  "think 
chemistry,"  the  success  and  possible  extent  of  the  teaching,  both  in 
the  fundamentals  and  in  the  superstructure  of  organic  and  physio- 
logical chemistry,  which  can  be  attained,  will  be  surprising  and  de- 
lightful to  both  instructor  and  pupil.  And  in  this  connection  it 
must  be  said  that  the  order  of  consideration  of  the  several  subjects 
which  has  been  here  followed,  because  it  is  logical,  is  not  recom- 
mended in  the  teaching  of  students.  The  study  should  begin  with 
that  of  a  few  elements  and  compounds,  the  consideration  of  the 
general  physical  and  chemical  principles  being  taken  up  as  material 
for  their  discussion  is  supplied.  The  manner  of  such  arrangement 
must  be  left  to  the  judgment  of  the  instructor. 

The  section  on  organic  chemistry  has  been  rearranged  in  the 
light  of  further  information  upon  the  relationships  of  substances, 

(iii) 


0884G 


IV  PEEPACE    TO    THE    PRESENT    EDITION 

and  somewhat  extended.  The  prominence  given  to  this  branch  of 
the  subject  the  author  believes  to  be  justified,  notwithstanding  its 
intricacy  and  the  impossibility  of  teaching  it  satisfactorily  to  those 
not  well  grounded  in  general  chemistry,  because  of  the  intimate 
connection  of  organic  chemistry  with  physiology  and  with  modern 
pharmacy,  and  the  impossibility  of  the  comprehension  of  the  prob- 
lems of  animal  and  pharmaceutical  chemistry  without  the  possession 
of  an  adequate  knowledge  of  the  principles  of  organic  chemistry. 
In  this  section  is  included  that  portion  of  physiological  chemistry 
treating  of  the  properties  and  chemical  relationships  of  those  sub- 
stances whose  constitution  is  known,  which  are  of  physiological  in- 
terest, a  branch  of  the  subject  which  is  properly  within  the  domain 
of  pure  chemistry. 

The  section  on  physiological  chemistry  has  been  almost  entirely 
rewritten  and  greatly  enlarged.  The  pure  chemistry  of  the  substances 
which  are  here  of  interest,  and  whose  constitution  is  known,  having 
been  considered,  in  their  proper  places  in  the  classification,  in  the 
preceding  sections,  this  one  is  devoted  to  the  consideration  of  the 
proteins  and  other  substances  of  still  unknown  constitution,  but 
particularly  to  the  composition  of  the  tissues  and  fluids  of  the  body 
and  the  chemical  processes  occurring  therein.  This  subject  is  one 
to  which  a  vast  amount  of  study  is  now  being  devoted,  and  neces- 
sarily there  are  many  questions  still  under  discussion  and  undeter- 
mined. These  have  been  either  passed  over  in  silence  or  briefly 
referred  to  as  undetermined,  to  avoid  the  necessity  of  future  revi- 
sion of  the  student's  information. 

It  may  appear  to  some  that  an  apology  is  in  order  for  the  extent 
to  which  this  book  has  grown.  The  only  one  which  the  author  has 
to  offer  is  that  he  has  endeavored  to  keep  pace  with  the  growth 
of  the  subject,  and  of  its  appreciation  by  the  medical  profession. 
Nothing  has  been  discussed  which  cannot  and  should  not  be  taught 
to  medical  students,  and,  although  no  part  of  what  is  herein  con- 
tained should  be  omitted  in  the  proper  training  of  an  intended 
physician  of  the  present  day,  the  question  of  how  much  of  it  it  should 
be  the  province  of  the  medical  school  to  supply  is  debatable,  but 
not  here.    The  whole  can  be,  and  is,  covered  in  two  years. 

R.  A.  W. 

New  Tore,  August,  1906. 


PREFACE  TO  THE  FIRST  EDITION. 

In  venturing  to  add  another  to  the  already  long  list  of  chemical 
test-books,  the  author  trusts  that  he  may  find  some  apology  in  this, 
tbst  the  work  is  intended  solely  for  the  use  of  a  class  of  students 
whose  needs  in  the  study  of  this  science  are  peculiar. 

While  the  main  foundations  of  chemical  science — the  philosophy 
of  chemistry — must  be  taught  to  and  studied  by  all  classes  of  stu- 
dents alike,  the  subsequent  development  of  the  study  in  its  details 
must  be  moulded  to  suit  the  purposes  to  which  the  student  will  sub- 
sequently put  his  knowledge.  And  particularly  in  the  case  of  medi- 
cal students,  in  our  present  defective  methods  of  medical  teaching, 
should  the  subject  be  confined  as  closely  as  may  be  to  the  general 
truths  of  chemistry  and  its  applications  to  medical  science. 

In  the  preparation  of  this  Manual  the  author  has  striven  to  pro- 
duce a  work  which  should  contain  as  much  as  possible  of  those  por- 
tions of  special  chemistry  which  are  of  direct  interest  to  the  medical 
practitioner,  and  at  the  same  time  to  exclude,  so  far  as  possible, 
without  detriment  to  a  proper  understanding  of  the  subject,  those 
portions  which  are  of  purely  technological  interest.  The  descrip- 
tions of  processes  of  mannfactnre  are,  therefore,  made  very  brief, 
while  chemical  physiolojjy  and  the  chemistry  of  hygiene,  therapeutics 
and  toxicology  have  been  dwelt  npon. 

The  work  has  been  divided  into  three  parts.  In  the  first  part  the 
principles  of  chemical  science  are  treated  of,  as  well  as  so  much  of 
chemical  physics  as  is  absolutely  requisite  to  a  proper  understanding 
of  that  which  follows.  A  more  extended  study  of  physics  is  pur- 
posely avoided,  that  subject  being,  in  the  opinion  of  the  author, 
rather  within  the  domain  of  physiology  than  of  chemistry. 

The  second  part  treats  of  special  chemistry,  and  in  this  certain 
departures  from  the  methods  usually  followed  in  chemical  text -books 
are  to  be  noted.  The  elements  are  classed,  not  in  metals  and  metal- 
loids— a  classification  as  arbitrary  as  unscientific — but  into  classes 
and  groups  according  to  their  chemical  characters. 

In  the  text  the  formula  of  a  substance  is  used  in  most  instances 

(v) 


▼i  PREFACE    TO   THE    P1K8T    EDITION 

in  place  of  its  name,  after  it  has  been  described,  with  a  view  to  givingr 
the  student  that  familiarity  with  the  notation  which  can  only  be 
obtained  by  continued  nse. 

In  the  third  part  those  operations  and  manipnlations  which  will 
be  of  utility  to  the  student  and  physician  are  briefly  described,  not 
with  the  expectation  that  these  directions  can  take  the  place  of  actual 
experience  in  the  laboratory,  but  merely  as  an  outline  sketch  in  aid 
thereto. 

Although  the  Manual  puts  forth  no  claim  as  a  work  upon  ana- 
lytical chemistry,  we  have  endeavored  to  bring  that  branch  of  the 
subject  rather  into  the  foreground  so  far  as  it  is  applicable  to  medical 
chemistry.  The  qualitative  characters  of  each  element  are  given 
under  the  appropriate  heading,  and  in  the  third  part  a  systematic 
scheme  for  the  examination  of  urinary  calculi  is  given.  Quantitative 
methods  of  interest  to  the  physician  are  also  described  in  their  appro- 
priate places.  In  this  connection  the  author  would  not  be  understood 
as  saying  that  the  methods  recommended  are  in  all  instances  the  best 
known,  but  simply  that  they  are  the  best  adapted  to  the  limited 
facilities  of  the  physician. 

The  author  would  have  preferred  to  omit  all  mention  of  Troy  and 
Apothecaries'  weight,  but  in  deference  to  the  opinions  of  those  ven- 
erable practitioners  who  have  survived  their  student  days  by  half  a 
century,  those  weights  have  been  introduced  in  brackets  after  the 
Metric,  as  the  values  of    degrees    Fahrenheit    have  been   made   to 

follow  those  Centigrade. 

E.  A.  W. 

Buffalo,  N.  T.,  September  16,  1883. 


TABLE  OF  CONTENTS. 

PAGE 

CHEMICAL  PHYSICS— GENERAL  CHEMISTRY 1 

Time  ~  Space — Bfatter — Force — Chemistry 1-3 

General  Properties  of  Matter : 

Indestractibility  —  Impenetrability  —  Diyisibility  —  Inertia —  Motion  — 
Mass  and  Weight — Gravity  —  Apparent  Weight — Momentum  — 
Measure  of  Force  -—  Work — Energy — Density —  Specific  Weight  — • 
States  of  Matter — Cohesion 3-13 

Special  Properties  of  Solids,  Liquids  and  Gases 13 

Crystallization — Allotropy — Diffusion — Boyle- Mariotte  Law —  Mixture 

of  Gases — Absorption  of  Gases 13-21 

Physical  Actions  of  Chemical  Interest 21 

Heat: 

Temperature — Thermometers — Thermal  Unit — Changes  in  Volume  — 
Dalton  -  GayLussac  Law  —  Absolute  Temperature  —  Gheneral  Gas 
Law — Dynamic  Theory  of  Heat — Kinetic  Theory  of  Gases — 
Change  of  State — Fusion  —  Heat  of  Fusion  —  Solution  —  Vaporisa- 
tion —  Gases  and  Vapors  —  Equilibrium  —  Boiling —  Sublimation — 
Heat  of  Vaporization — Specific  Heat 21-33 

Light: 

Index  of  Refraction — Spectroscopy — Polarimetry  —  Chemical  Effects 

of  Light 34-39 

Electricity: 

Insulators  —  Conductors  —  Ions — Galvanic  Electricity  —  Electromotive 
Force  —  Quantity  —  Resistance  —  Ohm's  Law — Current  Density — 
Divided  Currents  —  Electrolysis  —  Polarization  —  Electrical  Units — 
Resistance  and  Conductance  —  Electromotive  Force  —  Work  — 
Heat— Power 39-4C 

Chemical  Phenomena 47 

Elements  —  Non- elementary  Substances  —  Compounds  —  Physical  Mix- 
tures—  Molecular  and  Atomic  Theories  —  Atomic  Weight — Mo- 
lecular Weight  —  Mol  —  Molecular  Volume  —  Molecular  Heat  — 
Valence — Symbols,  Formulce  and  Equations— -Electrolysis — Acids, 
Bases  and  Salts  —  Concentration  —  Osmotic  Pressure  —  Electrolytic 
Dissociation  —  Stoichiometry  —  Nomenclature  —  Radicals  —  Com- 
position and  Constitution  —  Chemical  Energy  —  Chemical  Equi- 
librium—  Reversible  Reactions  —  Velocity  of  Reaction  —  Mass 
Action  —  Phase  Rule  —  Thermochemistry — Classification  of  Ele- 
ments—Periodic Law 47-104 

(vii) 


viii  TABLE    OP    CONTENTS 

PAOB 

INORGANIC  CHEMISTRY 106 

Typical  Elements 105 

Hydrogen 105 

Oxygen 109 

Compounds  of  Hydrogen  and  Oxygen:    Water — Natural  Waters — 
Hydrogen  Peroxid 113-124 

Elements  which  form  no  Compounds 125 

Helium  —  Neon — Argon — Krypton  —  Xenon 125 

Acidulous  Elements 125 

Chlorin  Group 125 

Flnorin 126 

Chlorin 127 

Compounds  of  Chlorin 130-133 

Bromin 133 

Compounds  of  Bromin 234-135 

lodin 135 

Compounds  of  lodin 136-137 

SuLFi^H  Grovp 138 

Sulfur  138 

Compounds  of  Sulfur 139-147 

Selenium  and  Tellurium 147 

Nitrogen  Group 148 

Nitrogen 148 

AtmospHerie  Air 149 

Com  pouTids  of  Nitrogen 151-159 

Phosphorus 159 

Compounds  of  Phosphorus 165-169 

Arsenic  169 

Compounds  of  Arsenic 170-182 

Antimony  183 

Compounds  of  Antimony 183-187 

BoHOK  Group • 187 

Boron  and  its  Compounds 187 

CARFiON  Ohoup 188 

Carbon 188 

Silicon  and  its  Compounds 190-191 

Vanadium  Group 191 

Vanadium  —  Niobium  —  Tantalium 191-192 

MoLYBDENUK  Group       192 

Molybdenum — Tungsten  —  Osmium 192 

Amphoteric  Elements 198 

Gold  Group |93 

Gk>ld  and  its  Compounds ljpS-194 

Iron  Group ,  .    194 

Chromium  and  its  Compounds ,  194-195 

Manganese  and  its  Compounds 195-197 

Iron  and  its  Compounds 197-203 


TABLE    OF    CONTENTS  ix 

PAOB 

Uranium  Gboup 203 

Uranium  and  its  Compounds 203 

Lead  Group 204 

Lead  a^d  its  Compounds 204-208 

Bismuth  Group 209 

Bismuth  and  its  Compounds 209-211 

Tin  Group 211 

Titanium 211 

Zirconium 211 

Tin  and  its  Compounds 212-213 

Platinum  Group 213 

Palladium  — Platinum 213-214 

Rhodium  Group 213 

Hhodinm  —  Ruthenium  —  Iridium 213 

Basilous  Elements 215 

Sodium  Group 215 

Lithium  and  its  Compounds 215-216 

Sodium  and  its  Compounds 216-221 

Potassium  and  its  Compounds 222-230 

Cesium — Rubidium 230 

Silver  and  its  Compounds 230-232 

Ammonium  Compounds 232-234 

Thallium  Group 235 

ThaUium 235 

Calcium  Group 235 

Calcium  and  its  Compounds 235-238 

Strontium  and  its  Compounds 238  239 

Barium  and  its  Compounds 239-240 

Maonesium  Group 240 

Magnesium  and  its  Compounds 240-242 

Zinc  and  its  Compounds 242-245 

Cadmium 245 

Aluminium  Group 245 

Beryllium  —  Scandium  —  Gallium  —  Indium 246 

Aluminium  and  its  Compounds 245-248 

NicKKL  Group 249 

Nickel 249 

Cobalt 249 

Copper  Group 250 

Copper  and  its  Compounds 250-254 

Mercury  and  its  Compounds 254-261 

ORGANIC  CHEMISTRY 262 

Compounds  of  Carbon : 

Homologous  Series  —  Isomerism — Elementary  Organic  Analysis  — De- 
termination of  Molecular  Weights  —  Determination  of  Constitu- 
tion— Nomenclature  —  Classification  of  Organic  Compounds  .  .  202-272 


TABLE    OF   CONTENTS 

PAGB 

Open  Chain,  Aliphatic,  Acyclic,  or  Fatty  Compounds 272 

Htdbooarbons 272 

Saturated  Compounds — Methanx  Series 272 

Hydrooarbons 272-277 

Haloid  DerivatiTes 277-282 

Oxidation  Products 282 

Alcohols 284-298 

Aldehydes  and  Ketones 298-308 

Aldehyde- alcohols — Ketone-aloohols— Aldehyde-ketones  and  Oxy- 

aldehyde- ketones 308 

Carbohydrates 309-327 

Carboxylic  Acids 327-338 

Aleohol-aoids— Oxyaoids 838-346 

Aldehyde -aoids 346 

Ketone-acids 347-348 

Oxyaldehyde  and  Oxyketone  Acids •  • 348 

Simple  Ethers 348-351 

Acid  Anhydrids 361-368 

Esters  —  Compound  Ethers 368-370 

Sulfur  DerivatiTes  of  the  Parai&ns 370-376 

Organo- metallic  Compounds 376-376 

Nitrogen  Derivatives  of  the  Paraffins 376 

Nitroparaffins 376-377 

Amins  and  Ammonium  Derivatives 377-382 

Oxyamins  —  Hydramins  —  Diamins  —  Imins  —  Diimins 382-388 

Amidins  —  Amidoxims  —  Hydroxamio  Acids 388 

Guanidin  and  its  Derivatives 388-390 

Hydrazins  —  Hydrazids 390 

Nitrils — Cyanogen  Compounds 391-399 

Amids 399-406 

Thiourea  and  Thiooarbamie  Acid 406-406 

Compound  Ureas 406-408 

Nitrogen  Derivatives  of  Alcohols,  Aldehydes  and  Ketones  ....  408-410 

Nitrogen  Derivatives  of  Acids 410-422 

Phosphorus,  Antimony  and  Arsenic  DerivatiTes 422-423 

Unsaturated  Aliphatic  Compounds •  •   •  .  .   423 

Hydrocarbons 423-426 

Halogen  Derivatives 426 

Oxidation  Products  .  .   .   '  ' 426-431 

Sulfur  and  Nitrogen  Compounds 432 

Closed  Chain  Compounds — Cyclic  Compounds 433 

CaRBOCTCLIO  COMPOXTNDS 434 

Hexacarboctclio  Compounds — Aromatio  Substanoss 436 

Monobenzenic  Compounds 440 

Hydrocarbons 440-442 

Haloid  derivatives 442 

Phenols 443-451 

Quinones 451 

Aromatio  alcohols 462 


TABLE    OF    CONTENTS  xi 

PAOB 

Alphenols 453 

Aldehydes 453 

Ketones ••••»..    455 

Aromatic  Carbozylio  Aoids ••••••  456-464 

Phenylic  Ethers  — Glueosids 464-468 

Anyhydrids  and  Acid  Halids 468 

Aromatic  Sulfur  Derivatives  —  Sulfonic  Acids 469 

Nitrogen -containing  Derivatives  of  Benzene 470-486 

Htdroarohatio  Compounds 486 

Hydrocarbons 48G-489 

'  Hydroaromatic  Alcohols 489-491 

Hydroaromatic  Ketones  and  Acids 491-493 

Compounds  with  Condensed  Nuclei 493 

Condensed  Hydrocarbons 494-496 

Haloid  Derivatives  —  Orientation 49!> 

Phenols  —  Alcohols — Aldehydes  —  Ketones  —  Quinones  —  Carboxylio 

Acids 497-500 

Nitrogen  Derivatives  . 500 

DiPHENYL  and  its  DERIVATIVES 501 

DlPHENTL- PARAFFINS —DiPUENTL-OLEFINS—DlPHENYL-AOETTLBNXS    .    .     502 

Phenols  —  Alcohols  —  Ketones  and  Carboxy lie  Derivatives 503 

Nitrogen -containing  Derivatives 504-506 

Heteroctclio  Compounds 507 

Mononucleate  Heterocyclic  Compounds 509 

Five-membered  rings 509-516 

Siz-membered  rings 51C-537 

Condensed  Heterocyclic  Compounds 537 

Condensed  Nuclei  Containing  Oxygen  or  Sulfur  Members 539 

Condensed  Nuclei  Containing  a  Nitrogen  Member 539-544 

Phenyl- PYRiDYL — Dipyridyl  and  Pyridyl- pyrrole  Compounds  .  .  .    645 

Alkaloids 545-570 

Ptomains,  Leucomains  and  Toxins 570-573 

PHYSIOLOGICAL  CHEMISTRY 674 

Proteins 675 

Native  Albumins 583-591 

Proteids 591-595 

AlDuminoids 595-597 

Chemico- physiological  Processes 597 

Ferments  and  Enzymes 599-606 

Digestion 606 

Saliva 606-608 

Oastrio  Juice  and  Gastric  Digestion 608-625 

Pancreatic  Secretion  and  Digestion 626-631 

Intestinal  Secretions 632 

The  Bile 633-642 

Chemical  Changes  in  the  Intestine 642-649 


xii  TABLE    OF    CONTENTS 

PAGK 

The  Blood 649 

Plasma  and  Seram 650-656 

Blood  Corpnsoles 656-667 

The  Blood  as  a  Whole 667-669 

Blood  Seram  and  Bacterial  Action 669-675 

Physico-chemical  Examination  of  Blood 675-677 

Changes  in  Composition  of  the   Blood   in   Different  Parts  of  the 
Circulation 677-692 

Lymph  — Chyle— Transudates — Exudates 692-694 

Urine 694 

Physical  Characters 694-699 

Normal  Mineral  Constituents 699-706 

Normal  Organic  Constituents 706-733 

Abnormal  Constituents    .  .   .  , 733-758 

Urinary  Calcuu 758-761 

Milk 761-767 

APPENDIX 769-781 

INDEX 783 


SIGNS  AND  ABBREVIATIONS. 

The  figures  in  parentheses  indicate  the  page  upon  which  the  meaning  of  the 
sign  or  abbreTiation  is  described. 


Aq 

= Water  of  crystallization  (116). 

a 

^Coefficient    of    expansion     of 

C 

=Current  strength  (41 ) . 

gases. 

C 

=Component  (97). 

Wd 

=Speoific  rotary  power  for  sodium 

C* 

=Asymmetrio  carbon  atom  (313). 

light  (38). 

C.O.S.=Centimeter  :gram  :second  (6, 7) . 

atm 

= Atmospheric  pressure  (8).        ^ 

D 

=Den8ity  (9). 

b.p. 

=Boiling  point  (32) . 

E 

=Eleotromotive  force  (40)  t 

cal. 

=Gram  calorie  (20). 

EMF 

=ElectromotiTe  force  (40). 

cc 

=Cubic  centimeter  (1). 

F 

=Faraday  (72). 

o.c. 

=Cubic  ceutimeter. 

F 

= Degree  of  freedom  (94). 

c» 

=Cubio  centimeter. 

H.P. 

=Hor8e  power  (8) . 

cm' 

=Cubic  centimeter. 

K 

= Rational  calorie  (20). 

cm 

=Centimeter  (1). 

L 

=Liter  (2). 

cm* 

=Square  centimeter  (7). 

M 

=Molecule  (53). 

d 

=Dextrogyrous  (311,  313) • 

N 

=Normal  (65). 

d-fl 

=Racemic  (311,  313). 

N/IO 

=Tenth  normal,  etc. 

dm 

=Decimeter  (1). 

NDioo  =Normal  current  density  (43). 

f.p. 

=Fu8ing  point  (26). 

P 

= Weight  (9). 

gm 

=Gram  (6,  779). 

P 

=Pha«e  (93). 

i 

=Racemic  (311,  313). 

R 

=Re8i8tance  (41). 

i 

=l80  (274). 

R 

=A  cyclic  compound  (434). 

k 

= Velocity  constant  (91). 

8S 

=Standard  solution  (65). 

kg 

=Kilogram  (779). 

T 

= Absolute  temperature  (21). 

kg:cul=Large  calorie  (20). 

V 

= Volume  (9). 

kg:m 

I  =Kilogram: meter  (8). 

Vm 

=Molecular  volume  (58). 

km 

=Kilometer  (1,  778). 

Vs 

=Specific  volume  (9) . 

1 

=L8Bvogyrous  (311,  313). 

A 

= Ampere  (43). 

m 

=Meter  (1). 

C 

= Asymmetric  carbon  atom  (313). 

m 

=Meta  (438). 

r 

=Coulomb  (43). 

mm 

=Millimeter  (1). 

F 

=Force  (7). 

n 

=Indez  of  refraction  (34). 

J 

= Joule's  equivalent  (20). 

[n]D 

—Index  of  refraction  for  sodium 

K 

^Dissociation  constant  (75), 

light  (34). 

K 

= Kinetic  energy  (8). 

0 

=Ortho(438). 

'V 

=Kilojoule  (20). 

P 

= Weight  (8). 

Arc 

=Kilowatt  (44). 

P 

=Para  (438). 

Mw 

=Molecular  weight  (56). 

p/m 

=Per  thousand. 

P 

= Pressure. 

ppt. 

=Precipitate. 

T 

=Cryoscopic  constant  (68). 

r 

=Racemio  (311,  313). 

r 

=Volt(43). 

sec 

=Mean  solar  second  (1,  7). 

V 

=Mean  velocity  (5). 

sp.  gl 

r.=Specific  gravity  (8). 

w 

=Work  (8). 

t 

=Temperature  in  degrees  Centi- 

ff 

=Watt  (44). 

grad. 

wj 

=Joule  (8). 

t 

= Variation  of  temperature  (68)» 

(xiii) 


Xir                                    SieXs  AND  ABBSEVlATIOXs 
T           =V«itUM    •). 

«         «AM«teacioB  4 

0Br«f33^.  A  =Eq«rv«Las  ccaiaeszTitT  (75). 

cv        »8p«eiie  1m«s  at   iliif  ml-      7  =Di«oeaSfti fcMSaon  ,74). 

UM    H  .  V  =<roBMft£nCM«    ia    gnms    pei 
f         sAenUnr-oQorgzmTitjtCi.                              c«bw  ««B:i»cG»r    74-. 

i          KVfta't  Hoff^i  fMtor  '74/.  s  —  ?p>g^l>  wadsfCiTity  (41K 

I          «U«ftk,  »pa«.  diariT ■  (4).  X  =  Wav«  >B«tk  of  li^bt   36 1 . 

M         — ¥iM  (^j  ^  =XfluWfiIarc«BidnetiTitT  ^74). 

p         =sPrcMttf ,  B«cer. 

I          sTxflM.  +  =D»A^mjwm»    311.  313). 


«         —Ttloeitj.  —       ■^LgiumwM  (3U,  313). 

>        -M«.difl#r«M(7i). 


THE  MEDICAL  STUDENT'S 

MANUAL  OF  CHEMISTRY. 


CHEMICAL   PHYSICS-GENERAL   CHEMISTRY. 

Time  and  Space. — In  the  study  of  the  phenomena  affecting 
material  objects  we  have  to  do  with  the  elementary  concepts  of 
time  and  space,  only  in  so  far  as  we  have  occasion  to  measure  those 
fractions  thereof  which  come  within  human  comprehension. 

The  unit  of  time -measure  is  the  mean  solar  day,  which  is  the 
average  duration  of  the  intervals  between  366  successive  meridional 
transits  of  the  sun,  i.  e.,  apparent  days.  This  average  is  takeu 
because  apparent  days  are  not  exactly  equal  to  each  other.  For 
physical  and  chemical  investigations  this  unit  is  too  large,  and  the 
fraction  which  is  used  is  the  mean  solar  second  (sec.)  6A466  of  the 
mean  solar  day. 

Space,  or  that  fraction  thereof  of  which  we  have  knowledge,  may 
be  said  to  be  the  interval  between  any  two  or  more  locations.  The 
unit  of  measure  of  space  in  one  dimension,  length,  is  the  distance, 
at  the  temperature  of  melting  ice,  between  two  lines  upon  a  bar  of 
platiniridium  preserved  near  Sfevres,  in  Prance;  many  accurate  copies 
of  which  are  also  preserved  in  other  places.  It  is  the  fundamental 
unit  of  the  entire  system  of  metric  measures,  weights  and  coinage, 
and  of  numerous  scientific  units,  and  is  called  the  meter  (m.).  It 
was  intended  to  be  ToiroWoirof  the  earth^s  meridional  circumference, 
from  which  it  varies  very  slightly.  It  is  equal  to  39.37079  inches. 
This  unit  is  subdivided  decimally,  and  its  fractions  are  indicated  by 
the  Latin  numerals:  the  meter  contains  10  decimeters  (dm.),  100 
centimeters  (cm.),  and  1000  millimeters  (ram.)  (as  the  dollar  con- 
tains 10  dimes,  100  cents,  and  1000  mills) .  The  multiples  of  the  meter 
are  designated  by  the  Greek  numerals:  10  raeters=l  decameter,  100 
meters=l  hectometer,  and  1000  meters=l  kilometer. 

The  measures  of  space  in  two  dimensions,  area,  are  the  squares  of 
the  measures  of  length;  and  the  measures  of  spaee  in  three  dimen- 
sions, volume,  are  their  cubes.   A  cubic  decimeter  is  called  a  liter 

A  (1) 


2  MANUAL  OP    CHEMISTRY 

(L),  which  contains  1000  cubic  centimeters  (cc.,  or  c.c,  or  c.^, 
or  cm.^). 

Matter  and  Force. — ^As  we  only  become  cognizant  of  matter  by 
the  action  of  force  npon  it,  or  of  force  through  its  effects  upon  mat- 
ter, our  appreciations  of  each  are  so  interwoven  that  each  is  usually 
defined  in  terms  of  the  other.  This  "argument  in  a  circle"  may  be 
avoided  by  saying  that  matter  is  that  which  occupies  space.  A 
given  space  may  be  occupied  by  widely  varying  amounts  of  matter, 
from  the  trace  Of  highly  tenuous  vapor  in  a  barometic  vacuum  to  the 
most  compact  metal.  Even  the  interplanetary  spaces,  as  well  as  the 
spaces  between  the  molecules  (p.  4)  of  material  substances,  are  filled 
with  the  luminiferous  ether,  which,  although  extremely  subtile, 
must  be  considered  to  be  material.  The  amount  of  matter  in  unit 
space  determines  its  concentration  (p.  64).  If  this  amount  be  rela- 
tively large  the  form  in  which  the  matter  exists,  gas,  solution,  etc., 
is  said  to  be  concentrated,  if  relatively  small  it  is  said  to  be  dilute. 

In  popular  language  the  words  "matter"  and  "substance  "  are  used 
sjrnonyraously;  but  in  chemical  language  the  latter  word  has  a  more 
narrow  meaning.  A  substance  is  a  species  of  matter,  having  con- 
stant characters  and  properties  by  which  it  may  be  recognized,  and 
differentiated  from  other  substance  species,  irrespective  of  its  shape. 
Thus  sulphur,  water,  chalk  are  chemical  substances,  each  of  which, 
in  any  form  in  which  it  may  appear,  has  definite  qualities  by  which  it 
may  be  distinguished  from  all  other  species  of  substance. 

Force  is  that  which  produces,  or  tends  to  produce  motion,  or 
change  of  motion  of  matter. 

Different  species  of  force  differ  in  the  character  of  the  motion 
which  they  produce,  and  in  the  magnitude  of  the  quantities  of  matter 
upon  which  they  act;  from  gravitation,  which  acts  upon  all  bodies, 
even  to  the  greatest,  to  chemical  force,  which  acts  upon  the  most 
minute  particles,  the  atoms  (p.  5.*^).  Light,  heat,  sound,  electricity, 
mechanical  motion  are  other  species  of  force.  These  several  species 
are  convertible  one  into  the  other  in  certain  definite  quantitative 
relations;  as  when  mechanical  force  is  transformed  into  heat,  electri- 
city, light,  etc.  (pp.  9,  22). 

Chemistry. — The  simplest  definition  of  chemistry  is  a  modifica- 
tion of  that  given  by  Webster:  That  branch  of  science  which  treats 
of  the  composition  of  substances,  their  changes  in  composition, 
and  the  laws  governing  such  changes. 

A  bar  of  soft  iron  may  be  made  to  emit  light  when  heated,  or 
sound  when  caused  to  vibrate,  or  magnetism  when  under  the  influ- 
ence of  an  electric  current.  Under  the  influence  of  these  physical 
forces  the  iron  suffers  no  change  in  composition,  and,  on  cessation 
of  the  action  of  the  inciting  force  the  iron  returns  to  its  original 


GENERAL  PROPERTIES  OF  MATTER  3 

condition.  But  if  the  iron  be  heated  in  an  atmosphere  of  oxygen^ 
both  the  iron  and  a  part  of  the  oxygen  disappear,  and  a  new  sub- 
stance, a  new  chemical  species,  is  produced,  having  properties  of  ita 
own,  different  from  those  of  either  the  iron  or  the  oxygen.  In  this 
case  there  has  been  chemical  action,  causing  change  of  composition, 
as  the  new  substance  contains  both  iron  and  oxygen.  The  result  of 
such  action  is,  moreover,  permanent,  and  the  new  product  continues 
to  exist,  until  modified  by  some  new  manifestation  of  chemical  action. 
While  chemical  action  is  thus  different  in  its  results  from  the 
actions  of  physical  forces,  there  exists  the  most  intimate  relation 
between  them.  As  above  stated,  they  are  interconvertible.  The  line 
of  demarcation  between  chemical  actions  and  certain  physical  actions, 
such  as  solution,  although  distinct,  is  narrow.  Many  chemical 
actions  take  place  only  under  certain  physical  conditions,  such  as  of 
temperature;  or  are  provoked  by  physical  forces,  such  as  light. 
Indeed,  the  entire  structure  of  theoretical  or  general  chemistry  has 
among  its  most  secure  foundations  results  obtained  in  the  study  of 
chemical  physics,  which  is,  therefore,  a  most  important  collateral 
branch  of  chemistry  as  well  as  of  physics. 

GENERAL  PROPERTIES  OF   MATTER. 

Indestructibility. — The  result  of  chemical  .action  is  change  in  the 
composition  of  the  substance  acted  upon,  a  change  accompanied  by 
corresponding  alterations  in  its  properties.  Although  we  may  cause 
matter  to  assume  a  variety  of  different  forms,  and  render  it,  for  the 
time  being,  invisible,  yet  in  none  of  these  changes  is  there  the 
smallest  particle  of  matter  destroyed.  When  carbon  is  burned  in  an 
atmosphere  of  oxygen,  it  disappears,  and,  so  far  as  we  can  learn  by 
the  senses  of  sight  or  touch,  is  lost;  but  the  result  of  the  burning  is 
an  invisible  gas,  whose  weight  is  equal  to  that  of  the  carbon  which 
has  disappeared,  plus  the  weight  of  the  oxygen  required  to  burn  it. 

Impenetrability. — Athough  one  mass  of  matter  may  penetrate 
another,  as  when  a  nail  is  driven  into  wood,  or  when  salt  is  dissolved 
in  water,  the  ultimate  particles  of  which  matter  is  composed  cannot 
penetrate  each  other,  and,  in  cases  like  those  above  cited,  the  particles 
of  the  softer  substance  are  forced  aside,  or  the  particles  of  one 
substance  occupy  spaces  between  the  particles  of  the  other.  Such 
spaces  exist  between  the  ultimate  particles  of  even  the  densest  sub- 
stances. 

Divisibility. — All  substances  are  capable  of  being  separated  by 
mechanical  means  into  minute  particles.  Although  we  have  no  direct 
experimental  evidence  of  a  limit  to  this  divisibility,  we  are  warranted 
in  believing  that  matter  is  not  infinitely  divisible.    A  strong  argu- 


4  MANUAL    OF    CHEMISTRY 

ment  in  favor  of  this  view  is  that,  after  physical  subdivision  has 
reached  the  limit  of  its  power  with  compound  substances,  these  may 
be  further  subdivided  into  smaller,  dissimilar  quantities  by  chemical 
means.  The  limit  of  physical  subdivision  of  matter  is  the  molecule 
of  the  physicist,  the  smallest  quantity  of  matter  with  which  he 
has  to  deal,  the  smallest  quantity  that  is  capable  of  free  existence 
(pp.  52,  56). 

Inertia — is  that  negative  quality  of  matter  by  virtue  of  which  it 
cannot  of  itself  produce  any  change  in  the  condition  of  rest  or  of 
motion  in  which  it  may  be.  If  matter  be  at  rest  it  can  only  be  put  in 
motion  by  the  expenditure  of  work  upon  it,  and,  if  it  be  in  motion, 
such  motion  will  continue,  rectilinear,  uniform,  and  indefinite,  unless 
interfered  with  by  the  interposition  of  other  energy  (p.  7). 

Motion. — A  material  particle  is  a  body  of  such  small  relative 
magnitude  that  it  may  be  considered  as  being  concentrated  in  a 
point.  The  earth,  in  its  relations  to  the  solar  system,  is  a  material 
particle,  while  in  its  relation  to  smaller  objects  near  its  surface  it  is  a 
body  of  enormously  preponderating  magnitude. 

The  absolute  position  of  a  particle  in  space  cannot  be  fixed,  but 
its  relative  position,  usually  referred  to  as  its  position  may  be  fixed 
by  three  arbitrary  coordinates,  x,  y,  z;  as  the  position  of  the  balloon 
may  be  located  by  its  latitude,  longitude,  and  elevation  above  the 
sea -level. 

Motion  or  displacement  of  a  particle  is  a  change  in  its  position. 
The  velocity  (v)  of  motion  of  a  particle  is  the  rate  of  its  change  of 
position  in  a  given  direction,  expressed  in  space  or  distance  (Z),  and 

time  {t):  i.  e.,  v=y,  (I).  Velocity  is  uniform  when  the  spaces  trav- 
ersed in  equal  times  are  equal  to  each  other.  It  is  accelerated  when 
such  spaces  are  unequal;  positively  accelerated  when  they  become 
greater,  negatively  accelerated  when  they  become  less.  Motion  is 
uniformly  accelerated  when  the  rate  of  change  in  equal  times  is 
constant. 

The  following  are  Newton's  Laws  of  Motion :  I.  All  bodies  per- 
severe in  a  state  of  rest  or  in  a  state  of  uniform  motion  in  a  straight  line, 
except  in  so  far  as  they  are  made  to  change  that  state  by  the  action  of 
force,  II  a.  The  rate  at  which  the  velocity  of  a  particle  changes  is  parallel 
ayid  proportional  to  the  force  acting  upon  the  particle,  lib.  The  rate 
at  which  a  given  force  changes  the  velocity  of  a  particle  is  inversely 
proportional  to  the  mass  of  the  particle  (seep.  5).  III.  Action  is  equal 
to  reaction  and  in  a  contrary  direction, 

Tlie  first  law  is  a  statement  of  the  condition  of  inertia,  when  no 
for(»p  is  acting.  But  the  fact  that  a  particle  is  at  rest  does  not  imply 
that  no  force  is  acting  upon  it.    It  will  remain  at  rest  when  two  or 


GENERAL  PROPERTIES  OP  MATTER  5 

more  forces  are  acting  upon  it  in  snch  manner  that  their  algebraic 
snm  i&  zero;  when  the  forces  are  in  equilibrium. 

Any  constant  and  uniform  force,  acting  without  interference, 
produces  a  rectilinear  and  uniformly  accelerated  motion  of  the  par- 
ticle to  which  it  is  applied,  in  the  direction  of  action  of  the  force;  the 
amount  of  the  acceleration  being  proportionate  to  the  intensity  of  the 
force,  in  obedience  to  Ila  above. 

Uniformly  accelerated  motion  obeys  the  following  laws: 

Let  V  represent  the  velocity  at  the  end  of  time  t,  v    the  initial 

velocity,  and  a  the  acceleration,  then  a =—p  or,  if  v'=0,  as  it  does 

when  motion  begins  at  rest,  then  «=y,  (II).  That  is:  Tlte  velocities 
are  proportionate  to  the  times,  i.  e.,  1,  2,  3,  etc.  It  also  follows  that 
the  acquired  velocity  at  the  end  of  any  given  number  of  units  of 
time  is  v  =  at+v\  or,  if  t/=0;  v  =  at,  (III);  and  also  that  the  mean 
velocity  (F)  is  one-half  of  the  final  velocity,  plus  the  initial  velocity: 
V=Xat+v\  or,  if  v'=0;    V=Xat,  (IV). 

As  a=Y,  and  v=y;  0=-^,  (V).    That  is:    The  spouses  traversed 

are  proportionate  to  the  squares  of  the  times.  It  is  clear  also  that  the 
total  space  traversed  during  any  given  number  of  units  of  time  is  the 
same  as  would  have  been  traversed  with  a  tmiform  velocity,  equal 
to  the  mean  velocity  of  the  uniformly  accelerated  motion,  in  the  same 
number  of  units  of  time. 

It  may  also  be  demonstrated  that:  The  spaces  traversed  in  giv&n 
times  are  equal  to  one -half  of  the  acceleration,  multiplied  by  the  squares 
of  the  times:   l=Xat^,  (VI). 

Mass  and  Weight. — If  we  imagine  a  gun  so  mounted  that  its  re- 
coil may  take  place  without  friction  in  a  vacuum,  and  that  the  veloc- 
ity of  the  recoil  and  the  muzzle  velocity  of  the  projectile  may  be 
accurately  measured,  we  will  find  that  these  velocities  are  not  equal. 
As  here  one  and  the  same  force,  the  explosion  of  the  powder,  pro- 
duces both  motions,  they  should  be  in  all  respects  equal,  in  obedience 
to  Newton's  laws  Ha  and  III  (p.  4),  were  it  not  that  the  two  bodies 
have  different  masses  ;  and,  in  obedience  to  Newton's  law  lib,  if  the 
velocity  of  the  recoil  be  10  feet  per  second,  and  the  muzzle  velocity 
of  the  projectile  1,000  feet  per  second,  the  two  masses  are  inversely 
as  these  velocities,  i.  e.,  the  mass  of  the  projectile  being  1,  that  of 
the  gun  is  100. 

If  now  the  projectile  be  a  one-pound  shot,  the  weight  of  the  gun 
will  be  found  to  be  100  pounds,  i.  e.,  the  mass  is  proportionate  to  the 
vreight;  and  the  mass  of  a  body  is  usually  determined  by  ascertaining 
its  absolute  iveight,  i.  e.,  its  weight  in  a  vacuum.  But  mass  is  not 
weight,  for  if  we  could  transfer  the  experiment  with  the  gun  to  the 


6  MANUAL   OP    CHEMISTRY 

WQter  of  the  earth,  the  ratio  between  the  two  velocities  would  remain 
the  same,  bat  neither  gan  nor  the  projectile  would  have  any  weight. 
Weight  is  a  manifestation  of  the  attraction  of  gravitation  of  the  earth. 
Gravity. — All  material  particles  mutually  attract  each  other;  and 
the  foree  of  such  attraction  between  two  particles  is  directly  as  the 
product  of  their  masses,  m  and  m\  and  inversely  as  the  distance  /, 

which  separates  them:  — j — .     Between  three  or  more  particles  the 

attraction  exerted  upon  each  is  the  resultant  of  the  attractions  of  all 
of  the  others. 

A  body  may  be  considered  as  made  up  of  particles,  and  the  attrac- 
tion between  two  bodies  is  the  sum  of  all  the  attractions  between  the 
particles  of  which  they  are  composed.  These  attractions  may  be 
reduced  to  a  single  resultant,  exerted  between  two  points  which  are 
the  centers  of  mass,  or  of  inertia,  or  of  gravity  of  the  two  bodies. 
The  attraction  of  gravitation,  which  the  earth  exerts  with  surround- 
ing bodies,  is,  therefore,  a  force  which  is  manifested  as  weight  when 
not  fwe  to  cause  motion,  and,  when  free  to  do  so,  produces  motion 
of  the  lesser  mass  in  a  straight  line  toward  the  center  of  mass  of  the 
earth,  and,  as  the  force  of  gravity  is  constant  and  uniform,  such 
motion  is  uniformly  accelerated. 

The  force  of  gravity  has  served,  by  the  use  of  Atwood's  machine, 
for  the  study  of  uniformly  accelerated  motions.  It  has  been  deter- 
mined that  the  acceleration  of  gravity,  g,  which  varies  with  the  alti- 
tude and  the  latitude,  is  9.8048  meters  per  second  at  the  sea-level  and 
in  latitude  45°.  There  a  freely  falling  body  acquires  velocities  of 
9,8048,  19.6096,  29.4144,  etc.,  meters  per  second  in  1,  2,  3,  etc.,  sec- 
onds (Eq.  II,  p.  5);  and  traverses  4.9024,  9.8048,  14.7072,  etc., 
meters  during  1,  2,  3,  etc.  seconds  (Eq.  V). 

Apparent  Weight. — The  weight  of  a  body  as  determined  with  our 
balances  is  not  exactly  the  same  as  the  absolute  weight  if  the  weights 
and  the  boiiy  weighed  be  not  of  the  same  size.  All  bodies  weighed 
in  air  suffer  a  loss  of  absolute  weight  by  the  amount  of  the  weight  of 
the  air  which  they  displace.  Therefore,  if  the  body  weighed  be 
vahnuinous  and  light,  and  the  weights  heavy  and  small,  the  bouyant 
offtvt.  of  the  air  is  greater  upon  the  former  than  upon  the  latter,  and 
the  apparent  weight  of  the  former  is  by  so  much  less  than  its  abso- 
hUe  weight.  In  ordinary  chemical  operations  the  difference  between 
iibiiolute  and  apparent  weight  is  so  slight  that  it  is  neglected. 

lu  weighing,  pieces  of  brass,  platinum,  aluminum  or  quartz,  of 
<ijK>Anite  mass,  and  referred  to  a  standard,  are  used  as  weights.  The 
^uil  v*f  these  weights  is  the  gram,  gm.,  which  is  toW  of  the  weight 
xvf  ii  luass  of  platiniridium,  preserved  along  with  the  standard  meter 
k\K  IV  whose  weight  is  in  turn  equal  to  the  weight  of  one  cubic 


GENERAL  PROPERTIES  OF  MATTER  7 

decimeter  of  pure  water  at  4°C.     The  gram  is,  therefore,  the  weight 

of  one  cubic  centimeter  of  pure  water  at  4°C.     The  fractions  and 

multiples  of  the  gram  are  designated  in  the  same  manner  as  those  of 

the  meter.     (See  Table  II  in  the  Appendix.) 

Momentum. — Newton's  second  law  of  motion  (p.  4)  refers  to 

what  is  now  called  momentum.     The  power  of  producing  results,  of 

doing  work,  of  a  moving  body  depends  upon  both  its  mass  and  its 

velocity.     The  product  of  the  mass  of  a  moving  body,  multiplied  by 

ml  —— — 

its  velocity  is  its  momentum:  mv,  or  — ,  (VII). 

Measure  of  Force— C.  G,  S,  System. — The  measure  of  force  is 
also  derived  from  mass  and  velocity.  The  unit  of  measure  of  force  is 
that  force  which,  acting  upon  unit  mass  during  unit  time,  produces  a 

velocity  of  unit  distance  in  unit  time:   ^^="7"X-^=-^,  (VIII).    And, 

as  a  uniformly  accelerated  force  produces  at  the  end  of  the  first  unit 
of  time  a  velocity  equal  to  its  acceleration  (p.  5),  force  is  measured 
by  the  mass,  multiplied  by  the  acceleration:  F=ma. 

In  these  algebraic  expressions  any  values  may  be  chosen  for  the 
several  quantities;  the  mass  m  may  be  measured  in  grams,  kilos, 
pounds,  etc.;  the  distance  /  in  centimeters,  meters,  feet,  etc.;  and 
the  time  t  in  seconds,  minutes  or  hours. 

For  scientific  measurements  the  C.  G.  S.  system,  sometimes  erro- 
neously called  the  system  of  absolute  units,  has  been  universally 
adopted,  and  includes  units  for  the  measurement  of  a  great  variety  of 
quantities.  The  system  owes  its  name  to  the  selection  of  the  centi- 
meter, cm.,  the  gram,  gm.,  and  the  second,  sec,  as  the  units  respec- 
tively of  distance  (space  in  one  dimension),  mass  and  time.  From 
these  three  fundamental  units  all  others  are  derived.  Thus  the  unit 
of  area  is  the  square  centimeter,  cra^,  and  the  unit  of  volume  is  the 
cubic  centimeter,  cm^.  The  unit  of  momentum  is  the  momentum  of 
a  body  having  a  mass  of  one  gram,  moving  with  a  velocity  of  one 

.»       .  t     ,  ml     inn.Xoiii. 

centimeter  per  second;  i.  e.,y=     ^^^ — 

In  this  system  the  unit  of  force  is  called  the  dyne,  and  is  that 
force  which,  acting  upon  a  mass  of  one  gram  for  one  second,  gener- 

,      ..        I,  .•       1  1      •  w*t?     ml     ffm.Xcm. 

ates  a  velocity  of  one  centimeter  per  second;   i.  e.,  -y'=-^=    .  ^^  ^  ' 

The  dyne  is  nearly  equivalent  to  0.102=7iT,  the  weight  of  one  milli- 
gram. As  a  larger  unit  the  megadyne  =  dyne  X  W,  and  nearly 
equivalent  to  the  weight  of  1.02  kilo,  is  used.  The  C.  G.  S.  units  in 
many  cases  are  too  small  or  too  large  for  general  use,  and  for  techni- 
cal purposes  so-called  practical  units,  having  definite  relations  to  the 
C.  O.  S.  units,  have  been  adopted. 

In  the  English  system  the  unit  of  force  is  the  poundal,  which  is 


8  MANUAL    OP    CHEMISTRY 

that  force  which,  acting  upon  a  mass  of  one  pound  for  one  second, 
generates  a  velocity  of  one  foot  per  second.  It  is  equal  to  13,825 
dynes. 

Work. — To  cause  a  change  in  the  position  of  a  particle  requires 
an  exertion  which  is  called  work  (p.  4).  Energy  is  said  to  do  work, 
therefore,  whenever  it  initiates  or  arrests  motion,  or  changes  such 
motion,  or  maintains  it  in  opposition  to  the  effects  of  other  work.  If 
the  distance  through  which  a  particle  is  moved  be  doubled,  double 
the  amount  of  work  will  be  required  to  effect  the  change.  The  rela- 
tion of  work  to  unit  force  is  measured  by  the  space  through  which 

ml 

motion  is  effected:    W=Fl.   Or,  if  unit  force  be  F=y,  (Eq.  VIII, 

p.  7),  unit  work  is  W=-^,  and,  as  v=~ff  (Eq.  I);    W=mv^f  (IX). 

That  is,  work  is  equal  to  the  mass,  multiplied  by  the  square  of  the 
velocity. 

The  C.  6.  S.  unit  of  work  is  the  amount  of  work  done  by  unit 
force,  one  dyne  (p.  7),  working  through  unit  space,  one  centimeter, 

in  unit  time,  one  second,  and  is  called  the  erg:  Erg=^^^^™'  .    For 

most  purposes  the  erg  is  inconveniently  small,  and  a  multiple  thereof, 
10^  ergs,  called  the  joule,  W>,  is  generally  used.  For  technical  uses 
work  may  also  be  measured  in  foot-pounds,  or  kilogram-meters 
(kg:m.),  i.  e.,  the  work  required  to  raise  one  pound  through  one 
foot,  or  one  kilogram  through  one  meter  in  opposition  to  gravity. 
One  kg:m.  is  equal  to  9.81X10^  ergs. 

The  conception  of  work  takes  no  account  of  the  time  in  which  the 
work  is  done.    When  this  is  considered  the  result  is  known  as  power, 

and  is  measured  in  terms  of  unit  work  done  in  unit  time:    -r.    The 

C.  0.  S.  units  are  one  org  per  second:  erg:sec.,  and  the  watt,  which  is 
one  joule  per  sec:W/:sec.  The  technical  unit  is  the  horse  power 
(H.  P.),  which  is  550  foot-pounds  per  second.  The  French  ^^ force  de 
cheval"  is  75  kilogram -meters  per  second,  and  equal  to  542.48  foot- 
pounds per  second. 

Energy. — As  a  result  of  the  expenditure  of  work  upon  matter,  the 
latter  may  be  placed  in  a  relation  in  which  the  actual  performance  of 
work  ceases,  but  in  which  the  matter  has  acquired  a  position  from 
which  it  is  capable  of  doing  work.  Thus,  to  lift  a  stone  to  the  top  of 
a  wall  from  the  ground  requires  the  expenditure  of  a  definite  number 
of  foot-ponnds  of  work.  Supported  on  the  wall  the  stone  does  no 
work,  but  if  allowed  to  fall,  it  can  in  so  doing  develop  the  same 
number  of  foot-ponnds  of  work  as  wore  required  to  lift  it.  Energy 
includes  both  that  exertion  which  is  doing  work,  which  is  known  as 
actual  or   kinetic  energy,  and   that  capacity  to  do  work  which   is 


GENERAL  PROPERTIES  OF  MATTEB 


known  as  possible  or  potential  energy.  The  relative  amounts  of  the 
two  forms  change  constantly,  bnt  their  sum  is  a  constant  quantity; 
i.  e.,  energy^  like  matter^  van  neUhar  he  created  nor  destroiffd. 

One  form  or  variety  of  energy  miiy  be  converted  into  another^ 
and  when  such  coo  version  takers  place  thin-e  exist  definite  qnantita- 
live  relations  between  the  two  forms  or  varieties.  There  is  a  general 
tendency  toward  the  conversion  of  all  forms  and  varieties  of  energy 
into  the  one  form  of  heat,  which  in  turn  tends  to  diffuse  itself 
uniformly  throughout  all  matter.  This  tendency,  which  is  referred 
to  as  the  degradation  or  dissipation  of  energy,  must  lead,  if  con- 
tinned,  to  a  final  uniform  temperature  throughout  the  universe,  and 
the  consequent  cessation  of  all  physical  plienomena. 

There  is  no  general  quantitative  expression  of  potential  energy, 
except  by  difference.  But  for  kinetic  energy,  such  an  expression  may 
be  derived  from  comparison  with  a  capacity  to  do  work.  As  the 
work  performed  by  the  earth's  attraction  upon  a  freely  falling  body 
finds  its  expression  in  the  increase  of  kinetic  energy,  as  W=^mv^^  and 
as  the  mean  velocity  of  uniformly  accelerated  motion  beginning  at 
rest  is  one -half  of  its  final  velocity,  the  measure  of  kinetic  energy 
is  one-half  of  the  product  of  the  mass,   multiplied   by  the  square 


of  the  final  velocitv:   K^ 


or,  in  C.  O.  S.  units:  %  erg. 


=y  be- 


Density. — The  absolute  density  of  a  body  is  the  ratio  between  its 

P 
volume  and  its  weight,   and  is  obtained  by  the  formula  D=y*   iu 

which  D  is  the  density,  P  the  weight,  and  V  the  volume.  Clearly,  also 
P=^VD,  and  V=|- 

When  V  is  taken  as  the  unit  of  volume  the  equation  D- 

csomes  D  =  P;  i.  e.,  the  absolute  densitif  of  a  stthstance  is  the  weight  of 
Hftit  volume  of  that  stthsianee.  But  as  thr  wcij^ht  of  a  given  volume 
of  a  substance,  particularly  in  the  liquid  or  aeriform  state,  varies 
with  differences  of  temperature  and  of  pressure,  a  definite  temperature 
and  pressure  have  been  arbitrarily  selected  as  constituting  normal 
conditions*  The  temperature  is  0°C.,  and  the  pressure  that  of  a 
column  of  mercury  76  centimeters  high  at  45°  latitude.     As  one  liler 

oxygen  weighs  1.4291  grams,  and  one  liter  of  hydrogen  weighs 
1,0900  gram  under  normal  comlittons,  L4291  and  0.0900  are  the 
Absolute  densities  of  oxygen  and  hydrogen  respectively.  As  1  cc.  of 
air  weighs  .001293  gra.  under  normal  conditions,  the  absolute  density 
of  a  gas  for  1  cc.  may  be  obtained  by  multiplying  its  specific  gravity, 
air  1  (p,  10),  by  .001293.  Thus  the  specific  gravity  of  oxygen  being 
1.1054,  1  cc,  of  oxygen  weighs  1. 1054 X  .001293=. 001429  gms. 

Pressures  are  measured  either  by  the  height  of  a  column  of  mer- 
cury which  the  pressure  will  sustain  in  opposition  to  gravity,  in  cm. 


10  MANUAL    OF    CHEMISTRY 

or  mm.;  or  in  atmospheres,  one  atm.  being  the  pressure  which  will 
sustain  a  column  of  mercury  of  the  avei-age  height  of  the  barometer; 
i.  e.,  760  mm.  As  the  specific  gravity  (below)  of  mercury  is  13.6  at 
O^C,  1  cc.  of  mercury  weighs  13.6  gms.,  and  each  mm.  of  mercurial 
column  is  equivalent  to  a  pressure  of  1.36  gms.  per  sq.  cm.,  and  one 
atm.  of  pressure  is  equal  to  1033.6  gms.  per  sq.  cm. 

The  Specific  Weight,  or  Specific  Gravity,  or  Relative  Density  of 
a  substance  is  the  weight  of  a  given  volume  of  the  substance  as  com- 
pared with  the  weight  of  an  equal  volume  of  some  substance,  accepted 
as  a  standard  of  comparison,  under  like  conditions  of  temperature 
and  pressure.  The  sp.  gr.  of  solids  and  liquids  are  referred  to  water, 
and  are  usually  determined  at  15°C.  To  express  the  sp.  gr.  of  solids 
and  of  heavy  liquids,  the  weight  of  one  cc.  of  watrr  is  taken  as  the 
unit.  Thus  the  sp.  gr:  of  sulfuric  acid  being  1.84,  1  cc.  of  water 
weighing  1  gm.,  1  cc.  of  sulfuric  acid  weighs  1.84  gms.  For  light 
liquids  one  liter  of  water  is  the  unit.  Thus  1  L.  of  a  liquid  of  sp. 
gr.  1026  weighs  1026  gms.,  or  1.026  kg.  In  metric,  therefore,  the 
weight  of  1  cc,  or  of  1  L.  of  a  liquid  represents  its  specific  gravity. 

The  specific  gravities  of  aeriform  bodies  are  expressed  in  three 
different  ways.  They  are  usually  determined  with  reference  to  pure, 
dry  air  at  0°C.  and  76  cm.  Arbitrarily,  air  is  the  unit  referred  to 
when  the  term  "specific  gravity"  is  used  in  speaking  of  a  gas.  If 
the  molecular  weight,  H=l  (p.  56)  of  a  gas  be  known,  its  specific 
gravity  is  obtained  by  dividing  its  molecular  weight  by  28.728.  For 
<5ertain  purposes  hydrogen  is  taken  as  the  unit.  As  air  is  14.364 
times  heavier  than  hydrogen,  the  sp.  gr.  of  a  gas  (air=l),  multiplied 
by  14.364  gives  its  sp.  gr.  (hydrogen=l). 

In  the  third  form  of  expression  of  specific  gravities  of  gases, 
the  specific  gravity  of  oxygen  is  taken  as  32,  and  the  unit  is  a 
hypothetical  normal  gas,  which  is  32  times  lighter  than  oxygen. 
Expressed  in  terms  of  this  unit  the  specific  gravity  of  a  gas  is  called 
its  density,  and  is  32  for  oxygen  and  2.016  for  hydrogen.  The  den- 
sity (0=32)  may  be  derived  from  the  sp.  gr.  (air  =  l)  by  multiplying 
it  by  28.95.    Thus  the  sp.  gr.  of  oxygen:  1.1054X28.95=32.00. 

The  specific  volume  of  a  substance  (Vs)  is  the  reciprocal  of  its 

absolute  density:  Vs=-p-,  and  is  the  volume,  in  cc,  which  one  gram 

occupies  under  normal  conditions.  Thus  for  hydrogen:  .6doo^^=lllll 
cc,  or  11.11  L.,  for  oxygen:  .001^4^ ft  =699. 7  cc,  and  for  air: 
.i>6i\^t=17BA  cc 

Determination  of  Specific  Gravity. — If  the  substance  be  a  solid, 
heavier  than  water  and  insoluble  therein,  it  is  attached  by  a  fine 
platinum  wire  to  one  arm  of  the  balance,  and  weighed,  first  in  air 
and  then  in  water  (Fig.  1).    The  weight  in  air,  divided  by  the  loss 


GENERAL  PROPERTIES  OP  MATTER 


11 


Fio.  1. 


of  weight  in  water  (which  is  eqaal  to  the  weight  of  the  dis- 
placed water)  gives  the  specific  gravity.  If  the  substance  be  in 
powder,  the  operation  is  similarly  conducted,  except 
that  the  powder  is  placed  in  a  small  glass  or  plati- 
num bucket,  whose  weight  in  air  and  in  water  are 
known  and  subtracted  from  the  corresponding  total 
weights.  If  the  solid  be  lighter  than  water,  a  suffi- 
cient bulk  of  a  heavy  substance,  whose  specific  gravity 
is  known,  is  attached  to  it,  and  the  same  method 
followed,  the  loss  of  weight  of  the  heavy  substance 
in  water  being  subtracted  from  the  total  loss.  If 
the  substance  be  soluble  in  water  its  specific  gravity 
is  similarly  determined  with  reference  to  some  other 
liquid  in  which  it  is  insoluble,  and  whose  specific 
gravity  is  known.  The  specific  gravity  so  obtained, 
multiplied  by  that  of  the  liquid  used,  gives  the  specific  gravity 
of  the  solid. 

To  determine  the  specific  gravity  of  liquids  they  are  first  brought 
to  the  required  temperature,  usually  15°C.,  and  the  determination  made 
with  the  specific  gravity  balance,  the  hydrometer,  or  the  picnometer. 
The  operation  of  the  specific  gravity  balance  depends  upon  the 
principle  of  Archimedes:  that  a  body  completely 
immersed  in  a  liquid  is  subjected  to  an  upward 
pressure,  and  consequent  loss  of  weight,  equal  to 
the  weight  of  the  displaced  liquid.  The  essential 
part  of  the  balance  is  a  solid  glass  sinker,  whose 
volume  is  made  exactly  1  cc,  or  10  cc.  The  loss  of 
weight  of  this  sinker  when  immersed  in  a  liquiil, 
therefore,  gives  the  specific  gravity  of  the  liquiil 
directly  with  a  1  cc.  sinker,  and  by  moving  the  deci- 
mal point  one  place  to  the  left  with  one  of  10  cc. 

The  action  of  the  hydrometer,  which  is  also 
called  by  other  names,  such  as  urinometer,  lacto- 
meter, alcoholometer,  etc.,  according  to  adapta- 
tions of  its  graduation  to  special  uses,  is  based  upon 
the  fact  that  a  solid  whose  weight  is  less  than  that 
of  an  equal  volume  of  a  liquid  will  sink  in  the 
liquid  until  it  has  displaced  a  volume  thereof  whose 
weight  is  equal  to  its  own.  The  hydrometer^  is, 
therefoi'e,  an  instrument  to  determine  the  volume 
of  a  liquid  whose  weight  is  that  of  the  instrument. 
This  is  done  by  means  of  a  graduation, 
which  gives  the  specific  gravities  directly, 
upon  the  thin  stem  (Fig.  2)  of  the  spindle,  fiq.  2. 


12 


MANUAL   OP    CHEMISTRY 


which  IS  caused  to  float  upright  b}^  beiug  weighted  at  its  lower  end. 

Hydrometers  are  useful  for  rapid  determinations  in  which  scientific 

accuracy  is  not  required,  but  either  of   the   other  two  methods    is 

preferable. 

The  picnometer,  or  specific  gravity  bottle,  in  some  one  of  its  forms, 

gives  the  most  accurate  results.  The  usual  form  is  that  shown  in  Fig. 
3,  a  bottle  blown  in  thin  glass,  having  a  perforated 
stopper,  which,  when  completely  filled,  contains 
accurately,  a  certain  number  of  cc,  10,  25,  50» 
100,  or  1000,  at  15°,  and  whose  weight  is  known 
When  used,  the  bottle  is  completely  filled  with  the 
liquid  and  weighed.  The  weight  obtained,  minus 
that  of  the  bottle,  is  the  specific  gravity,  if  the 
bottle  contain  1000  cc,  iV  if  100  cc,  etc  If 
this  form  of  bottle  be  used  with  a  room  tempera- 
ture above  15°  (59°  Fahr.)  accurate  results  are 
not  obtained,  owing  to  the  expansion  of  the 
liquid  and  its  escape  and  evaporation  at  the  upper 
end  of  the  stopper.  To  avoid  this  inconve- 
nience, especially  with  volatile  liquids,  Sprengel's 
or  Ostwald's  picnometers  are  to  be  preferred,  or, 
better,  that  of  Riiber.  The  last  consists  of  a 
pipette,  B,  Fig.  4,  with  tubes,  b  and  rf,  of  small 

caliber,  and  of  exactly  20  cc.  capacity.     The  liquid  is  brought  to  the 

standard  temperature  in  the  vessel  A,  from  which  the  pipette  is  filled 

in  the  manner  shown  in  the  cut,  and  the  excess  drawn  off  with  filter 

paper  applied  at  the  end  of  h  un- 
til it  reaches  the  mark  on  d.    The 

pipette  is  then  placed  horizontally 

upon   one   pan    of    the   balance, 

and    the  tare    C,   whose    weight 

and  volume  both  equal  those  of 

B  when  filled  with  water,  is  placed 

on    the    other,   and    the    balance 

brought     into     equilibrium     by 

weights  in  one  or  the  other  pan. 
States    of    Matter.  —  Matter 

exists  in  the  three  forms  of  solid, 

liquid  and  gas   (or  vapor).    The 

term  fluid  applies  to  both  liquids 

and  gases;   the  former  being  dis- 
tinguished as  incompressible,  the 

latter  as  compressible  fluids  (pp. 

18,19).  PIG.*. 


FlO.  3. 


SPECIAL   PROPERTIES   OF    SOLIDS 


13 


Cohesion  is  the  force  by  which  molecules  of  the  same  kind  are 
held  together.  It  is  most  active  in  solids,  which  therefore  have 
definite  shape  and  magnitude.  In  liquids  it  is  much  less  active,  yet 
sufficient  to  maintain  a  definite  magnitude  of  the  liquid,  but  it  is 
in  part  overcome  by  gravity,  which  causes  the  liquid  to  assume  the 
shape  of  the  containing  vessel.  If  the  action  of  gravity  be  sus- 
pended, as  by  placing  a  drop  of  nitrobenzene  in  a  solution  of  salt  of 
the  same  specific  gravity,  cohesion  causes  the  liquid  to  assume  a 
spherical  shape.  In  gases  cohesion  is  almost  nil;  therefore,  the  shape 
and  volume  of  any  gas  are  those  of  the  containing  vessel.  Cohesion 
diminishes  with  the  addition  of  heat;  therefore,  by  adding  heat  to  a 
solid  it  is,  if  not  decomposed,  converted  into  a  liquid  and  then  into 
a  gas. 

SPECIAL  PROPERTIES  OP  SOLIDS,  LIQUIDS  AND  OASES. 

Crystallization.  —  Solid  substances  exist  in  two  forms,  amor- 
phous and  crystalline.  In  the  former  they  assume  no  geometric 
shape;  they  conduct  heat  equally  well  in  all  directions;  they  break 
irregularly;  and,  if  transparent,  allow  light  to  pass  through  them 
i*qnally  well  in  all  directions.  A  solid  in  the  crystalline  form  has 
a  definite  geometrical  shape;  conducts  heat  more  readily  in  some 
directions  than  in  others;  when  broken,  separates  in  certain  direc- 
tions, called  planes  of  cleavage,  more  readily  than  in  others;  and 
modifies  the  course  of  luminous  rays  passing  through  it  differently 
when  they  pass  in  certain  directions  than  when  they  pass  in  others. 

Crystals  are  formed  in  one  of  four  ways:  1.  An  amorphous  sub- 
stance, by  slow  and  gradual  modification,  may  assume  the  crystalline 
form;  as  vitreous  arsenic  trioxid  {q.  v.)  passes  to  the  crystalline 
variety.     2.  A   fused  solid,    on   cooling,    crystallizes;    as   bismuth. 


r3-«- 


7^ 


PlO.  5. 


3.  When  a  solid  is  sublimed  it  is  usually  condensed  in  the  form  of 
<Tystals.  Such  is  the  case  with  arsenic  trioxid.  4.  The  usual  method 
of  obtaining  crystals  is  by  the  evaporation  of  a  solution  of  the  sub- 
stanrt'.  If  the  evaporation  be  slow  and  the  solution  at  rest,  the 
orvsr.ils  are  large  and  well-defined.     If  the  crystals  separate  by  the 


14 


MANUAL   OP    CHEMISTRY 


sudden  cooling  of  a  hot  solution,  especially  if  it  be  ag^itated  dnring: 
the  cooling,  they  are  small. 

Most  crystals  may  be  divided  by  imaginary  planes  into  eqnal» 
symmetrical  halves.    Snch  planes  are  called  planes  of  symmetiy* 


1 
! 

1 
1 
1 
1 
1 
1 

A 

1      1 

1    ! 
1    ; 
1    1 

1 

Fio.  e. 

Thus  in  the  crystals  in  Fig.  5  the  planes  ab  ab,  ac  ac,  and  be  be  ar& 
planes  of  symmetry. 

When  a  plane  of  symmetry  contains  two  or  more  equivalent  linear 
directions  passing  through  the  center,  it  is  called  the  principal  plane 
of  symmetry;  as  in  Fig.  6  the  plane  ab  ab,  containing  the  equal 
linear  directions  aa  and  66. 

Any  normal  erected  upon  a  plane  of  s>Tnmetrj',  and  prolonged  in 
both  directions  until  it  meets  opposite  parts  of  the  exterior  of  the- 
crystal,  at  equal  distances  from  the  plane,  is  called  an  axis  of 
symmetry. 

The  axis  normal  to  the  principal  plane  is  the  principal  axis«. 
Thus  in  Fig.  6,  aa,  66,  and  cc  are  axes  of  symmetry,  and  cc  is  the- 
principal  axis. 

Upon  the  relations  of  these  imaginary  planes  and  axes  a  classifi- 
cation of  all  crystalline  forms  into  six  systems  has  been  based. 

I.  The  Cubic,  Regular,  or  Monometric  System. — The  crystals- 
of  this  system  have  three  equal  axes,  aa,  66,  cc.  Fig.  5,  crossing  each 
other  at  right  angles.  The  simple  forms  are  the  cube;  and  its  de- 
rivatives, the  octahedron,  tetrahedron,  and  rhombic  dodecahedron* 
The  crystals  of  this  system  expand  equally  in  all  directions  when 
heated,  and  are  not  doubly  refracting. 

II.  The  Right  Square  Prismatic,  Pyramidal,  Quadratic,  Tetrag- 
onal, or  Dimetric  System  contains  those  crj'stals  having  three  axes 
placed  at  right  angles  to  each  other — two  as  aa  and  66,  Fig.  6,  being- 
equal  to  each  other  and  the  third,  rr,  either  longer  or  shorter.  The 
simple  forms  are  the  right  square  prism  and  the  right  square  based 
octahedron.     The  crystals  of  this  system  expand  equally  only  in  two 


CRYSTALLIZATION 


15 


directiong  when  heated.    They  refract  light  donbly  in  all  directions, 
except  tbrongb  one  axis  of  single  refraction. 

III.  The  Rhombohedral  or  Hexagonal  System  includes  crystals 
having  four  axes,  three  of  which  aa,  aa,  aa.  Pig.  7,  are  of  equal 
length  and  cross  each  other  at  60°  in  the  same  plane;  to  which  plane 
the  fourth  axis,  cc,  longer  or  shorter  than  the  others,  is  at  right 
angles.  The  simple  forms  are  the  regular  six-sided  prism,  the 
regular  dodecahedron,  the  rhombohedron,  and  the  scalenohedron* 
These  crystals  expand  equally  in  two  directions  when  heated,  and 
refract  light  singly  through  the  principal  axis,  but  in  other  directions 
refract  it  doubly. 

IV.  The  Rhombic,  Right  Prismatic,  or  Trimetric  System.— The 
axes  of  crystals  of  this  system  are  three  in  number,  all  at  right  angles 
to  each  other,  and  all  of  unequal  length.  Fig.  6  represents  crystals 
of  this  system,  supposing  oa,  bb,  and  cc  to  be  unequal  to  each  other. 
The   simple  forms  are   the  right  rhombic  octahedron,   the  right 


Fig.  7. 


rhombic  prism,  the  right  rectangular  octahedron,  and  the  right  rec-- 
lingular  prism.  The  crystals  of  this  system,  like  those  of  the  two 
following,  have  no  true  principal  plane  or  axis. 

V.  The  Oblique,  Monosymmetric,  or  Monoclinic  System. — The 
crystals  of  this  system  have  tliree  axes,  two  of  which,  aa,  and  cc. 
Fig.  8,  are  at  right  angles;  the  third,  bh.  is  perpendicular  to  one  and 
oblique  to  the  other.  They  may  be  equal  or  all  unequal  in  length. 
The  simple  forms  are  the  oblique  rectangular  and  oblique  rhombic 
prism  and  octahedron. 


16  IIANUAL    OP    CHEMISTRY 

VI.  The  Doubly  Oblique*  Asymmetric,  Triclinic,  or  Anorihic 
System  contains  crystals  having  three  axes  of  unequal  length,  cross- 
ing each  other  at  angles  not  right  angles;  Fig.  8,  oa,  ftft,  and  cc  being 
unequal  and  the  angles  between  them  other  than  90°. 

The  crystals  of  the  fourth,  fifth,  and  sixth  systems,  when  heated, 
expand  equally  in  the  directions  of  their  three  axes.  They  refract 
light  doubly  except  in  two  axes. 

Secondary  Forms. — The  crystals  occurring  in  nature  or  produced 
artificially  have  some  one  of  the  forms  mentioned  above,  or  some 
modification   of  those   forms.      These   modifications,  or   secondary 


Fio.  8. 

forms,  may  be  produced  by  symmetrically  removing  the  angles  or 
edges,  or  both  angles  and  edges,  of  the  primarj'  forms.  Thus,  by 
progressively  removing  the  angles  of  the  cube,  the  secondary  forms 
shown  in  Fig.  9  are  produced. 

It  sometimes  happens  in  the  formation  of  a  derivative  form  that 
alternate  faces  are  excessively  developed,  producing  at  length  entire 
obliteration  of  the  others,  as  shown  in  Fig.  10.  Such  crystals  are 
said  to  be  hemihedral.  They  can  be  developed  only  in  a  system 
having  a  principal  axis. 

Isomorphism. — In  many  instaiu»os  two  or  more  substances  crystal- 
lize in  forms  identical  with  each  other,  and,  in  most  cases,  such 
substances  resemble  each  other  in  their  chemical  constitution.  They 
are  said  to  be  isomorphous.  This  identity  of  crystalline  form  does 
not  depend  so  much  upon  the  nature  of  the  elements  themselves,  as 
upon  the  structure  of  the  molecule.  The  protoxid  and  peroxid  of 
iron  do  not  crystallize  in  the  same  form,  nor  can  they  be  substituted 
for  each  other  in  reactions  without  radically  altering  the  properties  of 
the  resultant  compound.  On  the  other  hand,  all  that  class  of  salts 
known  as  alums  are  isomorphous.  Not  only  are  their  crystals  iden- 
tical in  shape,  but  a  crystal  of  one  alum,  placed  in  a  saturated 
solution  of  another,  grows  by  regular  deposition  of  the  second  upon 


CRYSTALLIZATION 


17 


its  surface.  Other  alums  may  be  subsequently  added  to  the  crystal,  a 
section  of  which  will  then  exhibit  the  various  salts,  layer  upon  layer. 
Dimorphism. — Although  most  substances  crystallize,  if  at  all,  in 
one  simple  form,  or  in  some  of  its  modifications,  a  few  bodies  are 
capable  of  assuming  two  crystalline  forms,  belonging  to  different 
systems.    Such  are  said  to  be  dimorphous.    Thus,  sulfur,  as  obtained 


Fig.  9. 

by  the  evaporation  of  its  solution  in  carbon  disulfid,  forms  octahedra, 
belonging  to  the  fourth  system.  When  obtained  by  cooling  melted 
sulfur  the  crystals  are  oblique  prisms  belonging  to  the  fifth  system. 
Occasional  instances  of  trimorphism,  of  the  formation  of  crystals 
belonging  to  three  different  systems  by  the  same  substance,  are  also 
known. 

Many  substances  on  assuming  the  crystalline  form,  combine  with 
a  certain  amount  of  water  which  exists  in  the  crystal  in  a  solid 
^•onibination.  Thus  nearly  half  of  the  weight  of  crystallized  alum 
is  water.  This  water  is  called  water  of  crystallization,  and  is  nec- 
<*ssary  to  the  maintenance  of  th(^  crystalline  form,  and  frequently 
to  the  color.  If  blue  vitriol  be  boated,  it  loses  its  water  of  crystal- 
lization, and  is  converted  into  an  amorphous,  white  powder.  Some 
crystals  lose  their  water  of  crystallization  on  mere  exposure  to  the 
^ir.  They  are  then  said  to  effloresce.  Usually,  however,  they  only 
lose  their  water  of  crystallization  when  heated  (p.  115). 

Allotropy. —  Dimorphism  apart,  a  few  substances  are  known  to 
exist  in  more  than  one  solid  form.      These  varieties  of  the  same 


^ 


Flu.  IJ. 


substance  exhibit  different  physical  properties,  while  their  chemical 
qnalities  are  the  same  in  kind,  but  differ  in  their  degrees  of  activity, 
^neh  modifications  are  said  to  be  allotropic.  One  or  more  allotropic 
modifications  of  a  substance  are  usually  crystalline,  the  other  or 
others  amorphous  or  vitreous.  Sulfur,  for  example,  exists  not  only 
in  two  dimorphous  varieties  of  crystals,  but  also  in  a  third,  allotropic 


18  MANUAL    OP    CHEMISTRY 

form,  in  which  it  is  flexible  and  amorphous.  Carbon  exists  in  three 
allotropic  forms:  two  crystalline,  the  diamond  and  graphite;  the  third 
amorphous. 

In  passing  from  one  allotropic  modification  to  another,  a  sub- 
stance absorbs  or  gives  out  heat. 

Liquids  when  subjected  to  pressure  diminish  in  volurfie  only  to 
a  trifling  extent:  mercury  by  0.000003  of  its  volume  per  atmosphere. 
When  the  pressure  is  released,  liquids  regain  their  original  volume. 
They  are  therefore  perfectly  elastic. 

Diffusion  of  Liquids — Dialysis. — If  a  liquid  be  carefully  floated 
upon  the  surface  of  a  heavier  liquid,  with  which  it  is  capable  of  mix- 
ing, as  brandy  upon  water,  two  distinct  layers  are  at  first  formed. 
But,  even  at  perfect  rest,  mixing  of  the  two  liquids,  in  opposition  to 
gravity,  will  begin  immediately,  and  progress  slowly  until  the  two 
liquids  have  diffused  into  each  other  to  form  a  single  liquid  whose 
composition  and  density  are  the  same  throughout. 

If,  in  place  of  bringing  the  two  liquids  into  direct  contact,  they 
be  separated  from  each  other  by  a  membrane  of  goldbeater's  skin, 
each  will  pass  through  the  membrane  into  the  other,  a  phenomenon 
called  osmosis,  but  they  do  not  pass  with  equal  rapidity.  Thus,  if 
the  two  liquids  be  alcohol  and  water,  one  part  of  alcohol  will  pass  in 
one  direction  while  4.2  parts  of  water  pass  in  the  other.  This  rela- 
tion, as  compared  with  water,  is  the  osmotic  equivalent  of  the  sub- 
stance, and  may  be  determined  not  only  for  liquids,  but  also  for 
solids  in  solution. 

If  a  layer  of  a  pure  solvent  (p.  27)  be  similarly  floated  upon  a 
solution  of  a  solid  in  the  same  liquid,  as  water  upon  a  solution  of 
sugar,  or  if  the  two  be  separated  by  a  membrane  of  parchment  paper, 
bladder,  or  other  permeable  membrane,  the  pure  solvent  will  pass 
into  the  solution,  and  the  dissolved  sugar  into  the  pure  solvent  until 
the  two  liquids  have  the  same  concentration,  i.  e.,  contain  the  same 
quantity  of  dissolved  substance  in  unit  volume  throughout.  (See 
solution,  p.  28.) 

Solids  in  solution  differ  in  the  rapidity  and  completeness  with 
which  they  undergo  osmosis,  or  dialyse.  Substances  which  crystallize, 
crystalloids,  dialyse  easily  and  with  relative  rapidity;  those  which 
do  not  form  crystals,  colloids,  do  not  dialyse,  or  do  so  with  extreme 
slowness.  Advantage  is  taken  of  this  difference  to  separate  crystal- 
loids from  colloids,  as  salt  from  albumin.  The  solution  of  the  two 
substances  is  placed  in  the  inner  vessel  of  a  dialyser  (Fig.  11), 
whose  bottom  consists  of  a  layer  of  parchment  paper,  and  the  outer 
vessel  is  filled  with  the  pure  solvent,  water,  which  is  frequently 
changed  as  the  crystalloid  collects  in  it.  Or  a  section  of  tubing 
made  of  parchment  paper,  bent  into  a  U  shape,  may  be  used  as  the 


SPECIAL   PROPERTIES    OF    GASES 


19 


I 


TlQ,  11. 


inner  vessel,  and  suspended  in  water.  Plates  of  porous  earthenware 
may  also  be  used  for  dialysis  of  liquids  whicti  would  attack  an  animal 
or  vegetable  membrane,  but  their  action  is  much  slower.  Semiper- 
meable membranes  are  membranes  whiah  are  permeable  to  certain 
dilfnsibte  substauees,  but  not 
to  others,  usually  permeable  to 
water  but  not  to  certain  sub- 
stances in  solution  in  it.  Bueli 
membranes  exist  in  animal  and 
vegetable  nature  and  are  formed 
artificially.  Pfeffer's  membrane 
is  obtained  by  placing  a  solu- 
tion of  eupric  sulfate  in  a  jar  of 
porous  earthenware,  which  is 
then  immersed  in  a  solution  of 
potassium  ferrocyanid.  A  deli- 
cate, gelatinous  film  of  eupric 
ferroeyanid  forms  in  the  walls 

of  the  jar  where  the  two  solutions  come  io  contact,  which  coustitutes 
th%  semipermeable  membrane,  permeable  to  water  and  to  saltpeter 
dissolved  in  water,  but  not  to  sugar  or  to  many  other  substances  in 
aqueous  solutiou.     (See  Osmotic  pressure,  p.  66.) 

Gases  when  subjected  to  pressure  dimiuish  in  volume  progres- 
sively to  an  amount  limited  only  by  their  passage  to  the  form  of 
liquid  (p.  29).  When  relieved  of  pressure  they  expand  to  an  unlmi- 
ited  extent.  They  have,  therefore,  the  volume  of  the  containing 
ve«sel,  upon  whose  walls  they  exert  a  pressure  corresponding  to  that 
to  which  tliey  are  themselves  subjected,  and  in  all  parts  of  which 
they  ha%'e  the  same  density. 

Boyle-Mariotte  Law. — If  any  gas,  maintained  at  a  constant  tem- 
perature,  be  contained  in  a  vessel  wiiose  capacity  may  be  altered,  as 
H  by  a  piston,  the  pressure  exerted  by  the  gas  is  found  to  be  doubled 
^^■niien  the  capacity  of  the  vessel  is  reduced  to  one -half;  and  corre- 
^HpHndirig  variations  of  pressure  are  observed  with  other  changes  in 
Hvolnme: 

^  7^^  femperaiure  remaining  the  sanu',  the  vohime  of  a  given  quantity 
&f  g»s  f>  inversely  as  the  prest^ure  (Boyle-Mariotte  Law).  Or:  v/>^^ 
tmstant.  And,  denoting  any  two  pressures  under  which  a  given 
Weight  of  gas  may  exist  by  pi  and  p2,  and  the  correspondiDg  volumes 
by  vi  and  V2,  as  pivi  and2>2V2,  both  equal  constant,  /JiVi^;?2V2  (p.  23) . 
It  ikbo  follows  that  the  density  of  a  gas  (pp.  9,  10)  is  proportionate  to 
*k€  T^ftaure. 

This  and  other  "gas  laws''  are  only  approximately  true,  although 
the  departure  from  them,  which  differs  with  different  gases,  is  very 


20  MANUAL    OF    CHEMISTRY 

slight  at  ordinary  pressures.  The  greater  the  pressure,  i.  e.,  the 
more  concentrated  the  gas,  the  wider  is  the  departure  from  the  rule; 
and  the  lower  the  pressure,  i.  e.,  the  more  dilute  the  gas,  the  smaller 
does  it  become,  and  the  nearer  does  the  gas  approach  to  the  state 
of  an  ideal  gas,  one  which  would  obey  the  law  exactly.    (See  p.  25.) 

Mixture  of  Gases. — In  agreement  of  what  has  been  said  above, 
if  a  vessel,  A,  containing  a  gas  under  any  given  pressure,  be  brought 
into  communication  with  another  vessel,  B,  of  equal  capacity,  in 
which  there  is  a  vacuum,  the  gas  will  instantly  fill  both  vessels 
equally,  and  in  each  the  pressure  will  be  one -half  the  original 
pressure. 

And  if  the  vessel  B,  in  place  of  being  vacuous,  contain  another 
gas,  between  which  and  the  gas  in  A  there  is  no  chemical  action,  and 
under  like  pressure,  the  pressure  in  each  will  remain  unaltered,  and 
particles  from  A  will  rapidly  pass  into  B,  and  also  from  B  to  A, 
until,  in  a  very  short  time,  this  interchange  of  particles  will  pro- 
duce a  condition  of  equilibrium,  and  both  A  and  B  will  contain  the 
same  relative  proportions  of  the  two  gases. 

In  a  mixture  of  gases  each  gas  retains  all  of  its  oicn  properties,  as 
if  the  other  or  others  were  not  present;  and  each  gas  is  unifortnly 
distributed  throughout  the  space  occupied, 

Dalton's  law  of  partial  pressures  and  the  third  law  of  absorp- 
tion (below)  ai'e  both  included  in  the  foregoing  statement.  The 
former  is  to  the  effect  that:  If  the  several  gases  composing  a  mixture 
and  the  mixture  all  have  the  same  temperature,  and  if  the  gases  sever- 
ally and  tlie  mixture  occupy  the  same  volume,  then  the  pressure  exerted 
hy  the  mixture  will  he  the  sum  of  the  pressures  exerted  by  the  several 
gases.  And  Vp=vipi+V2P2+V3P3+  .  .  .  .  The  pressure  of  each  gas 
in  the  mixture  is  called  its  partial  pressure. 

Diffusion  and  Effusion  of  Gases. — If,  in  place  of  bringing  two 
indifferent  gases,  of  different  densities  and  under  equal  pressures, 
into  direct  contact  with  each  other,  in  the  manner  above  referred  to, 
they  be  separated  by  a  porous  diaphragm,  mixture  takes  place  by 
diffusion  through  the  diaphragm,  but  more  slowly  and  unequally,  so 
that  the  pressures  upon  the  two  sides  of  the  diaphragm  become 
unequal.  That  gas  which  has  the  least  density  diffuses  the  most 
rapidly,  and  in  such  ratio  that:  The  quantities  of  gases  which  diffuse 
in  unit  time  are  inversely  as  the  square  roots  of  their  densities. 

Effusion  of  a  gas  is  its  passage,  not  through  a  porous  septum 
having  a  large  number  of  minute  pores,  but  through  a  single,  very 
small  opening  (0.013  mm.)  in  a  thin  metallic  plate.  Here  again 
the  velocities  of  efflux  of  several  gases  are  inversel}'  as  the  square 
roots  of  their  densities.  This  law  is  taken  advantage  of  in  an  appa- 
ratus for  the  rapid  determination  of  the  densities  of  gases. 


HEAT  21 

Absorption  of  Gases. — Physical  solution  (p.  27)  of  a  gas  in  a 
liquid  is  called  absorption.  The  absorption  of  gases  by  liquids  obeys 
the  following  laws: 

The  weight  of  a  gas  absorbed  by  unit  volume  of  a  given  liquid  is 
proportionate  to  the  gas  pressure  (Henry's  law). 

The  quantity  of  a  gas  absorbed  diminishes  with  increase  of  tem- 
perature. 

The  quantity  of  a  gas  which  a  liquid  can  absorb  is  independent  of 
the  nature  and  qtiantiiy  of  other  gases  which  it  may  already  hold  in^ 
solution. 

Some  solid  substances  also  absorb  certain  gases.  Sometimes  such 
absorption  is  a  physical  act,  when  it  is  referred  to  as  condensation 
or  absorption.  Thus  charcoal  condenses  about  90  times  its  volume  of 
ammonia.  In  other  cases  it  is  a  chemical  combination,  as  when 
caustic  potash  absorbs  carbon  dioxid. 


PHYSICAL  ACTIONS  OP  CHEMICAL  INTEREST. 

HEAT. 

The  Effects  of  Heat  upon  a  body  are  in  doing  internal  work:  to 
raise  its  temperature,  to  increase  its  volume,  to  change  its  state  of 
aggregation,  or  to  cause  atomic  rearrangement,  i.  e.,  chemical  change, 
or  in  doing  external  work:  in  exerting  pressure,  or  in  transmitting 
heat  to  surrounding  bodies. 

Temperature. — The  temperature  of.  a  body  is  the  extent  to  which 
it  can  impart  sensible  heat  to  surrounding  bodies.  It  is  not  to  be 
confounded  with  the  amount  or  quantity  of  heat  which  the  body  con- 
tains. A  block  of  ice  just  beginning  to  melt  and  the  same  weight 
of  water  just  beginning  to  freeze  have  the  same  temperature;  but 
heat  must  be  added  to  the  ice  to  continue  its  fusion  and  subtracted 
from  the  water , to  continue  its  solidification,  while  during  both  pro- 
cesses the  temperature  remains  the  same  in  each. 

Thermometers  are  instruments  for  the  measurement  of  temper- 
ature. They  are  usually  glass  tubes  having  a  bulb  blown  at  one 
end  and  closed  at  the  other,  the  bulb  and  part  of  the  tube  being  filled 
with  mercury  or  with  alcohol,  whose  contraction  or  expansion  indi- 
cates a  fall  or  rise  of  temperature.  The  alcoholic  thermometer  is  used 
for  measuring  low  temperatures,  and  the  mercurial  for  temperatures 
between— 40°  and  360°  C.  (680°  P.).  For  higher  temperatures 
instruments  called  pyrometers,  based  upon  the  expansion  or  variation 
of  electrical  conductance  (p.  42)  of  solids,  are  used. 

In  every  thermometer  there  are  two  fixed  points,  determined  by  ex- 
periment.  The  lower,  or  freezing  point,  is  fixed  by  immersing  the  in- 


22 


MANUAL    OP    CHEMISTRY 


— 100 


strnment  in  melting  ice,  and  marking  the  level  of  the  mercury  in  the 
tube  upon  the  glass  when  it  has  become  stationary.  The  higher,  or 
boiling  point,  is  similarly  fixed  by  suspending  the  instrument  in  the 
steam  from  boiling  water.  The  instrument  is  then  graduated  accord- 
ing to  one  of  three  scales :  the  Celsius,  or  Centigrad,  the  Fahrenheit, 
and  the  Reaumur.  The  freezing  point  is  marked  0°  in  the  Ceutigrad 
and  Reaumur  scales,  and  32®  in  the  Fahrenheit.  The  boiling  point 
is  marked  100®  in  the  Centigrad,  212°  in  the  Fahrenheit,  and  80°  in 
the  Reaumur  scale  (Fig.  12).  The  space  between  the  fixed  points  is 
divided  into  100  equal  degrees  in  the  Centigrad  scale,  into  180°  in 

the  Fahrenheit,  and  into  80°  in  the  Reau- 
mur. Five  degrees  Centigrad  are  there- 
fore equal  to  nine  degrees  Fahrenheit. 

To  convert  readings  in  one  scale  into 
terms  of  another  the  following  formula? 
are  used: 

Centigrad  to  Fahrenheit:  Multiply  by 
9,  divide  by  5,  and  add  32.  Example: 
50°C.  X  9  =  450  H-  5  =  90  +  32  =- 122°  = 
Ans. 

Fahrenheit  to  Centigrad:   Subtract  32, 
multiply  by  5,  and  divide  by  9.    Example: 
5°F.— 32=— 27X5  =  — 135  H- 9  =—15° 
=  Ans. 

The  Centigrad  scale  is  the  one  now 
exchisively  used  for  scientific  work. 

Measure  of  Heat-Thermal  Unit-Me- 
chanical Equivalent  of  Heat. — Heat  is 
measured  by  its  effect  in  raising  the  tem- 
perature of  a  given  weight  of  water 
through  a  given  number  of  degrees  of 
temperature.  Several  units  have  been 
used,  and,  unless  definitely  stated,  may  easily  lead  to  confusion. 

The  calorie,  or  therm,  or  gram-calorie  (eal.)  is  the  amount  of 
heat  required  to  raise  the  temperature  of  one  gram  of  water  from  0° 
to  1°C.  (or  from  4°  to  5°C.).  The  rational  calorie  (K)  is  the 
^ amount  of  heat  required  to  raise  the  temperature  of  one  gm.  of  water 
from  0°  to  100°  C,  and  is  nearly  equal  to  100  cal.  The  large  calorie, 
or  kilogram  calorie  (kg: cal.),  is  based  upon  the  raise  of  temperature 
of  one  kilogram  of  water  from  4°  to  5°  C,  and  is  equal  to  1000  cal. 

The  British  thermal  unit  is  the  amount  of  heat  required  to  raise 
the  temperature  of  one  pound  (Avdp.)  of  water  one  degree  Fahren- 
heit. And  still  another  unit  is  used,  based  upon  the  pound  of  water 
and  a  raise  of  temperature  of  one  degree  Centigrad. 


-32 


—  0 


^\ 


^\\6 


a  a  ^ 


PlO.  12. 


HEAT  23 

That  mechanical  motion  produces  heat,  and  that  heat  is  a  source 
of  mechanical  motion  are  well-known  facts.  It  has  also  been  experi- 
mentally demonstrated  that  a  certain  number  of  foot-pounds,  or  of 
ergs,  of  energy  produce  a  definite  number  of  calories  of  heat.  The 
numerical  relation  between  the  amounts  of  heat  and  of  mechanical 
motion  which  are  interconvertible  is  known  as  Joule's  equivalent 
(J).  It  was  first  determined  in  terms  of  the  British  thermal  unit  as 
772.55.  That  is,  the  amount  of  heat  required  to  raise  the  tempera- 
ture of  one  pound  of  water  one  degree  Fahrenheit  is  equivalent  to 
the  work  done  in  raising  772.55  pounds  through  one  foot;  i.  e., 
772.55  foot-pounds.  In  terms  of  Centigrad  degrees  and  kilogram - 
meters,  one  gram -calorie  is  equivalent  to  0.426  kilogram-meters.  In 
the  C.  G.  S.  system  one  gram-calorie  is  equal  to  4.18X10^  ergs,  or  to 
4.18  Joules  (p.  8). 

In  place  of  measuring  amounts  of  heat  in  calories  or  other  similar 
units,  they  may  be  expressed  in  terms  of  the  C.  G.  S.  system,  based 
upon  the  above  eiiuivalent,  in  kilojoules  (A:j),  equal  to  10^®  ergs. 
One  kilojoule  is  equal  to  239.1  gram -calories,  and  one  gram -calorie 
to  0.004183  kilojoules. 

We  will  use  gram -calories  or  kilojoules  in  expressing  amounts 
of  heat. 

Changes  in  Volume  Caused  by  Heat. — As  a  rule,  all  substances 
increase  in  volume  when  heated,  and  diminish  in  volume  on  losing 
heat.    There  are,  however,  some  exceptions  to  this  rule. 

Solids  and  liquids  change  only  slightly  in  volume  by  heating  or 
cooling.  Thus  the  coefficient  of  linear  expansion,  or  ratio  of  varia- 
tion in  length,  of  steel  is  .0000124,  and  the  coefficient  of  cubic 
expansion,  of  variation  in  volume  of  mercury  is  .00018  for  1°C. 
Water  on  being  cooled  contracts  until  its  temperature  is  4°C., 
between  which  and  0°  it  again  expands;  4°C.  is,  therefore,  the 
temperature  of  maximum  density  of  water. 

The  changes  in  volume  of  gases  by  heat  are  of  much  greater 
theoretical  importance  than  those  in  solids  and  liquids. 

We  have  seen  (p.  19)  that  the  volume  of  gas  varies  with  the 
pressure  in  obedience  to  the  law:  YP=consfavf.  Ti)is  is  only  true  if 
the  temperature  remain  constant.  With  variation  in  temperature  the 
volume  of  a  gas  varies  according  to 

The  Dalton-GayLussac  Law: — The  pressure  remaining  constant^ 
the  volume  of  a  gas  varies  directly  with  the  absolute  temperature  (see 
below).  And,  conversely,  if  the  volume  remain  constant,  the  pressure 
varies  directly  with  the  temperature. 

The  Law  of  Charles  is  to  the  effect  that  all  gases  have  the  same 
coefficient  of  expansion. 

All  gases,  when  cooled,  contract  by  t^t,  or  0.00367,  of  their 


24  MANUAL    OF    CHEMISTRY 

volume  for  each  diminution  of  temperature  of  tott  of  the  variation 
between  0°  and  100°.  The  coefficient  of  expansion  (a)  of  all  gases  t«, 
therefore,  .00367  per  degree  Centigrad,  and  is  the  same  whatever  the 
pressure  supported  by  the  gas.  Or,  the  temperature  remaining  con- 
stant: v  =  vo  (1+at),  in  which  v  is  the  volume  at  temperature  t,  a, 
the  coefficient  of  expansion  of  gases,  and  vo  the  volume  at  O^^C.  Or, 
introducing  the  numerical  value  of  a:  V  =  vo  (1  +.00367  t).  In  thi& 
statement  it  is  assumed  that  the  pressure  remains  constant,  and  the 
volume  varies.  If  the  volume  remain  constant,  the  pressure  varies, 
and:  p  =  Po  (1+at),  and|?=|)o  (l+.00367t),  in  which  p  is  the  pres- 
sure at  temperature  t,  and  Pq  the  pressure  at  0°. 

Absolute  Zero — Absolute  Temperature. — As  gases  contract  by 
T^T  of  their  volume  with  each  degree  of  diminution  of  temperature, 
unit  volume  of  gas  at  0°  on  continuous  cooling  would  occupy  zero 
volume  at  — 273°.  As  it  is  assumed  (p.  25)  that  at  that  temperature 
a  gas  contains  no  heat  — 273°  is  taken  as  the  absolute  zero,  and 
degrees  of  absolute  temperature  are  from  that  point:  T  =  273  +  t. 
Thus,  if  the  observed  temperature,  t,  be  54°C.  the  absolute  tempera- 
ture, T,  is  273+54=327.  No  gas  is  known  to  exist  at  so  low  a  tem- 
perature as  — 273°;  the  most  resistant,  hydrogen,  forms  a  liquid 
which  boils  at  — 252.5°,  and  this  temperature  can  only  be  slightly 
lowered  by  reducing  the  pressure.  The  lowest  temperature  yet 
attained  is  —263°. 

General  Gas  Law. — Considering  the  Boyle -Mariotte  and  Dalton- 
GayLussac  laws  jointly,  as  when  pressure  (or  volume)  and  tempera- 
ture both  vary,  the  two  equations  given  above ^may  be  combined  to: 
pv=|?oVo  (l+.00367t).     Or,  introducing  the  absolute  temperature: 

pv  =  ^Jp  T,  in  which  T  is  the  absolute  temperature,  t+273°. 

In  comparing  the  volumes  of  gases,  or  in  determining  the  relation 
of  their  weights  to  their  volumes,  these  are  reduced  to  normal  vol- 
ume, at  standard  temperature;  i.  e.,  0°C.,  and  standard  pressure; 
1.  e.,  that  of  76  cm.  of  mercury  at  45°  of  latitude  at  the  sea- level. 
These  are  also  referred  to  as  normal  conditions.     The  reduction  is 

made  by  the  formula:  vo=7g-rjTroo367l)'  ^^  which  vo  is  the  normal 
volume,  V  the  observed  volume  at  temperature  t,  and  p  the  observed 
pressure  in  cm.  of  mercury. 

Dynamic  Theory  of  Heat. — It  having  been  proven  that  heat  and 
mechanical  movement  are  convertible  one  into  the  other  in  certain 
definite  quantitative  relations,  it  may  be  considered  as  a  demonstrated 
fact  that  heat  is  a  form  of  energy  (p.  8).  And  as  energy  may  be 
potential  or  kinetic,  so  heat  energy  may  be  potential,  as  in  latent 
heat  (p.  26),  or  kinetic  as  in  sensible  heat.     Sensible  heat,  tempera- 


HEAT 


25 


tore,  is,  therefore,  a  mode  of  motion.  As  this  motion  is  one  of  io- 
visible  particles,  a  molei.uilar  njc^tion,  views  of  its  luiture  must  be 
theoretical.  It  is  asisiiruetl  that  the  motion  is  oscillatory^  or  vibra- 
liir>',  and  that  its  rapidity  and  aniiditiide  vary  with  tlie  amount  of 
heat;  that  the  hij,'fier  the  teiriperaliire  tlie  more  rapidly  do  the  mole- 
cules vibrate,  and  the  greater  the  length  of  their  paths.  This  view 
does  not  preclude  the  possibility  of  rotary  movements  of  the  mole- 
cules about  each  other  or  about  their  axes,  nor  yet  of  movements  of 
the  atoms  within  the  muleeules  (p.  53). 

Kinetic  Theory  of  Gases. — The  theory  stated  above  is  in  conso- 
nance with  all  oljserved  facts  coiiceriung  gaseous  bodies;  and  gases 
oflFer  the  best  material  for  Mie  development  of  the  ihei>ry,  on  account 
of  the  slight  cohesion  of  their  molecules  and  the  facility  with  wdiich 
they  may  be  appnniclied  to  or  sepnrat*:*d  from  each  otlier  by  vruMation 
of  pressure.  The  kint^tic  theory  of  gases  assumes  that  the  molecules 
of  gJises  are  sphericaK  perfectly  elastic,  extremely  small  in  compari- 
son to  the  spaces  by  which  they  are  separated,  and  in  constant  vibra- 
tory movement.  In  this  movement  they  occasionally  collide  with 
fh  other,  when,  by  virtue  of  their  perfect  elasticity  ajid  slight  cohe- 
sion, they  immediately  rebound  si>  that  their  total  path  becomes  a 
zigzag,  although  their  "free  path/'  i.  e.,  the  direction  and  distance 
ihriiugh  which  they  may  os(*ilIate  without  collision,  is  rectilinear,  and 
of  length  dependent  upon  the  prf»ximity  of  the  molecules;  i.  e.,  tlie 
pressore,  or  they  may  impinge  upon  the  walls  of  the  container^  and 
bound    therefrom,    and    in   this  w*ay  produce  pressure.     And    the 

sure  so  produced  is  proportionate  to  the  temperature  (p.  23)  be- 
cause the  rapidit\  of  oscillation,  and  therefore  the  number  of  impacts 
in  unit  time  increases  with  rise  of  temperature.  Conversely,  the  rapid- 
ity and  the  pressure  diminish  with  diminution  of  temperature,  and  it  is 
assumed  that  at  the  absolute  zero  it  ceases — there  is  no  heat. 

The  velocity  of  motion  of  all  the  molecules  in  a  given  volume  of 
gas  U  not  the  same.  By  collision  with  each  other  and  with  the  walls 
of  the  containing  vessel,  the  motion  of  some  of  the  molecules  is 
retarded,  so  tlmt  at  any  given  temperature  it  is  only  the  sum  of  the 
velocities  of  all  the  molecules  present,  or  their  average  velocity,  which 
is  a  constant  quantity. 

The  departure  in  the  action  of  gases  from  the  Boyle -Mariotte  law 
at  high  pressures  is  also  in  accordance  with  the  theory.  In  an  ideal 
gas,  one  which  w^ould  obey  the  low  accurately,  the  molecules  would 
b^  mathematical  points,  without  magnitude,  and  totally  without 
cohesion;  but,  although  extremely  small,  the  molecules  have  magni* 
lude.  and  their  cohesion,  although  slight,  is  not  nil,  and  conse- 
qneutly  at  each  collision  their  path  is  not  modified  as  it  would  be 
were  the  ideal  conditions  fulfilled:    and  as  the  molecules  are  closer 


26  MANUAL    OF    CHKMlJSTKY 

together,  and  consequently  more  frequently  in  collision,  the  smaller  the 
volume  of  unit  weight  of  gas,  i.  e.,  the  greater  the  pressure,  the  wid- 
est departure  from  the  law  would  be  anticipated  by  the  theory  at  high 
pressui-es,  where  it  is  found  to  occur  (p.  19).  Indeed,  a  formula  has 
been  constructed  for  the.  Boyle -Mariotte  law  (Van  der  WaaPs 
formula)  which  takes  into  account  the  magnitude  of  the  molecules 
and  their  cohesion,  and  expresses  the  actual  conditions. 

Change  of  State. — The  state  of  aggregation  of  matter  depends 
partly  upon  the  pressure  to  which  it  is  subjected,  but  principally 
upon  the  amount  of  heat  which  it  contains.  If  chemical  decomposi- 
tion does  not  occur,  when  heat  is  added  to  a  solid  the  motion  of  its 
molecules  becomes  more  rapid,  and  their  cohesion  becomes  less,  until 
the  solid  becomes  a  liquid.  With  the  addition  of  more  heat  the 
molecules  are  more  widely  separated,  their  cohesion  is  reduced  to  the 
minimum,  and  the  liquid  becomes  a  vapor.  The  reverse  order  of 
change  is  produced  by  abstraction  of  heat,  popularly  referred  to  as 
"cooling." 

Solids  assume  the  liquid  form  hy  fusion  or  by  solution. 

Fusion.— When  a  solid,  not  decomposed  by  heat,  is  sufficiently 
heated  it  fuses,  or  melts.  Substances  which  withstand  a  high  tem- 
I)erature  without  fusion  are  said  to  be  refractory.  Every  substance 
begins  to  fuse  at  a  certain  temperature,  which  is  always  the  same 
for  a  given  substance,  the  pressure  remaining  constant,  and  which 
remains  the  same  until  fusion  is  complete,  whatever  the  intensity  of 
the  heat  applied.  This  temperature  is  called  the  fusing  point  of  the 
substance,  and  is  one  of  the  characters  depended  upon  for  its  identi- 
fication, and  as  a  test  of  its  purity.  Some  substances  pass  by  imper- 
ceptible changes  of  gradual  softening  from  the  condition  of  solid  to 
that  of  liquid,  the  temperature  rising  the  while,  and  therefore  have 
no  true  fusing  point;   such  are  iron  and  glass.    (See  p.  29.) 

The  fusing  point  is  only  slightly  influenced  by  the  pressure. 
That  of  substances  which  contract  on  fusion  is  slightly  lowered  by 
increase  of  pressure,  and  that  of  those  which  expand  on  fusion  is 
slightly  raised. 

Heat  of  Fusion— Latent  Heat. — During  fusion  a  substance 
absorbs  heat,  and  during  the  opposite  process  of  solidification  it 
liberates  heat,  in  each  case  without  change  of  temperature.  The 
amount  of  heat  so  liberated  varies  with  different  substances,  and  is 
called  the  latent  heat  of  fusion  of  the  substance.  If  two  vessels, 
one  containing  a  pound  of  water  at  0°C.,  and  the  other  a  pound  of 
ice  also  at  0°C.,  be  both  immersed  in  a  large  vessel  containing  hot 
water,  the  two  smaller  vessels  will  absorb  equal  amounts  of  heat,  but 
when  the  ice  has  completely  melted  the  temperature  in  that  vessel 
will  be  O^'C,  while  that  in  the  other  vessel  will  be  79.3°C.;   therefore. 


HEAT  27 

iu  the  melting  of  the  ice  an  amount  of  beat  corresponding  to  79.3^ 
of  temperature  became  latent. 

Solution. — A  solid,  liquid  or  gas  is  said  to  dissolve,  or  to  form  a 
solution  in  a  liquid,  when  the  two  substances  form  a  homogeneous 
liquid.  The  molecules  of  the  dissolved  substance,  the  solute,  are 
assumed  to  be  uniformly  distributed  among  the  molecules  of  the 
liquid,  which  is  called  the  solvent. 

The  act  of  solution  may  be  a  purely  physical  process,  without 
chemical  action  between  the  solute  and  the  solvent,  in  which  case  it 
is  referred  to  as  physical  or  simple  solution ;  or  it  may  consist  of 
two  distinct  acts,  one  a  chemical  action  between  solute  and  solvent, 
and  the  other  the  physical  solution  of  the  new  substance  thus  pro- 
duced, in  which  case  it  is  called  chemical  solution.  A  physical  solu- 
tion contains  the  original  substance,  which,  if  a  solid,  can  be  recov- 
ered unchanged  by  evaporation  of  the  solution,  as  cupric  nitrate  from 
a  solution  of  that  salt,  however  obtained.  A  chemical  solution  is,  in 
fact,  a  physical  solution  of  the  new  substance  formed  in  the  reaction, 
as  cupric  nitrate  is  also  left  on  evaporation  of  a  solution  of  copper  in 
nitric  acid. 

(For  solution  of  gases,  see  Absorption,  p.  21;  and  for  solution  of 
liquids,  see  Mixture  of  Liquids,  p.  50.) 

The  quantity  of  a  single  solid  which  can  be  dissolved  in  a  pure 
solvent,  water  for  instance,  depends  upon  an  inherent  relation  be- 
tween solvent  and  solute,  called  the  solubility,  and  upon  the  tempera- 
ture. The  solubility  of  a  solid  is  one  of  its  distinguishing  characters, 
and  each  solid  has  a  definite  solubility  in  a  given  liquid  at  a  given  tem- 
perature. When  no  solvent  is  mentioned,  water  is  understood.  The 
solubility  is  roughly  qualified  by  the  terms  "freely,"  "readily,"  "spar- 
ingly," or  "slightly  soluble,"  and  "insoluble."  The  last  term  is  relative, 
as  few,  if  any,  solids  are  absolutely  insoluble;  it  is  applied  to  substances 
of  extremely  slight  solubility.  Numerical  expression  of  solubility  in 
parts  by  weight,  is  made  either  in  parts  of  the  solvent  required  to 
dissolve  one  part  of  the  solute,  or  in  parts  of  the  solute  contained  in 
100  parts  of  the  saturated  solution  (below),  or  in  parts  of  the  solute 
which  TOO  parts  of  the  solvent  will  dissolve.  Some  solids,  such  as 
calcium  chlorid,  are  so  readily  soluble  in  water  that  they  absorb  suffi- 
cient from  the  air  to  form  a  solution.  They  are  then  said  to  deli- 
quesce. On  the  other  hand,  calcium  sulfate  is  usually  ranked 
as  an  "insoluble"  substance,  its  solubility  being  0.254  parts  in  100 
at  35°. 

The  solubility  of  most  solids  increases  with  rise  of  temperature. 
With  some  the  increase  of  solubility  is  proportionate  to  the  rise  of 
temperature,  with  others  the  solubility  is  very  slightly  affected  by 
variation  of  temperature,  and  with  others  there  is  a  certain  tempera- 


28  MANUAL    OF    CHEMISTRY 

ture  of  maximum  solubility,  above  which  it  again  diminishes.     Thus 
35°  is  the  temperature  of  maximum  solubility  of  calcium  sulfate. 

A  solution  containing  as  much  of  the  solute  as  it  is  capable  of 
dissolving  at  the  existing  temperature  is  said  to  be  saturated.  If 
made  at  high  temperature  it  is  said  to  be  a  hot  saturated,  and  if  at 
the  ordinary  temperature  a  cold  saturated  soiution.  If  a  hot  satu- 
rated solution,  or  one  containing  more  solid  than  the  liquid  is  capable 
of  dissolving  at  a  lower  temperature,  be  cooled,  the  solid  usually  sep- 
arates in  the  crystalline  form.  But  if,  in  the  case  of  certain  sub- 
stances, such  as  sodium  sulfate,  the  solution  be  allowed  to  cool  while 
undisturbed,  no  crystallization  occurs,  and  the  solution  at  the  lower 
temperature  contains  a  larger  amount  of  the  solid  than  it  could  dis- 
solve at  that  temperature.  It  is  then  said  to  be  supersaturated.  If 
a  given  quantity  of  liquid  be  brought  in  contact  with  a  quantity  of 
solid  less  than  it  can  dissolve  at  the  existing  temperature,  the  solid 
dissolves  completely  to  form  an  unsaturated  solution ;  while  if  it  be 
in  contact  with  any  excess  of  the  solid,  such  excess  remains  undis- 
solved, and  has  no  influence  upon  the  solution  so  long  as  the  temper- 
ature remains  constant.  The  solubility  of  solids  is  also  influenced  by 
the  pressure,  but  to  so  trifling  an  extent  that  it  may  be  disregarded. 
Dilute  solutions  are  such  as  contain  very  small  quantities  of  the 
solutes,  and  the  more  dilute  they  are  the  more  nearly  do  they 
approach  the  condition  of  ideal  solutions;  i.  e.,  solutions  which 
would  obey  certain  very  important  laws,  as  an  ideal  gas  (p.  20)  would 
obey  the  Boyle -Mariotte  law.     (See  pp.  67,  73.) 

When  a  substance  is  acted  upon  by  two  immiscible  solvents 
(p.  50),  or  when  its  solution  in  one  such  solvent  is  agitated  with  the 
other  pure  solvent,  the  solute,  if  it  have  the  same  molecular  structure 
(pp.  52,  71)  in  both  solutions,  is  distributed  between  the  two 
solvents  in  the  ratio  of  its  solubility  in  each  at  the  existing  tem- 
perature, irrespective  of  differences  in  its  solubility  in  each,  and  of 
the  relative  volumes  of  the  two  solvents.  Thus,  if  varying  quantities 
of  iodin  be  dissolved  in  carbon  bisulfid  and  the  solutions  agitated 
with  water,  the  amounts  of  iodin  in  equal  volumes  of  the  two  solu- 
tions  will  be  in  the  proportion  of  1  in  the  water  to  420  in  the  bisulfide 
irrespective  of  the  absolute  amounts  of  the  solid  and  solvents  present. ' 
This  constant  ratio  between  the  concentrations  of  the  two  solutions 
is  called  the  coefficient  of  distribution.  If  more  than  one  solute  be 
present  under  these  conditions,  each  is  distributed  according  to  its 
own  coeflBcient  of  distribution,  as  if  the  other  or  others  were  not 
present. 

Congelation  is  the  passage  of  a  substance  from  the  liquid  to  the 
solid  form.  It  is  the  reverse  of  fusion,  and  takes  place  at  the  same 
fixed  temperature,  which  also  remains  constant  until  fusion  is  com- 


HEAT 


29 


plete.  This  temperature  is  called  the  freezing  point  of  the  subatauee. 
During:  eou gelation  au  amount  of  heat  et|ual  to  that  absorbed  during 
fusion  (p.  26)  is  liberated. 

The  freezing  point  of  a  liquid  holding  a  solid  iu  solution  18  lower 
than  that  of  tlie  pure  solvent.  The  amount  of  the  depression  is  pro- 
portionate to  the  quantity  of  the  solid  dissolvedi  and  varies  with  equal 
qauutities^  of  different  substances.  When  two  or  more  solids,  having 
un  chemical  action  upon  each  other,  are  in  sohiHon  in  the  saiue 
solvent,  the  freezing  point  is  lowered  by  an  amount  equal  to  the  sum 
of  the  depressions  which  each  would  produce  if  present  alone  (p.  G8). 

Superfusion,  or  Supercooling. — Liquids,,  when  in  small  volume^ 
in  the  absence  of  the  corresponding  solid,  and  kept  at  rest  or  in  very 
rapid  agitation,  may  be  cooled  several  degrees  behnv  their  freezing 
points  without  solidifying.  Thus  water,  free  fi-om  air,  may  be  cooled 
to  — 20*^  without  forming  ice.  On  moderate  agitation,  or  on  contact 
with  a  particle  of  the  solid,  solidification  takes  place  instantly,  the 
temperature  suddenly  rising  to  the  freezing  point  (p.  99). 

Vaporization.— The  passage  of  a  liquid  to  an  aeriform  state  may 
take  plaee  from  the  surface  of  the  liquid  onh%  when  the  process  is 
called  evaporation,  or  it  may  take  place  throughout  the  mass  of  the 
liquid,  when  it  is  called  ebullition,  or  boiling.  Another  difference 
between  the  two  processes  is  that  lioiling,  at  a  constant  pressure,  only 
occurs  at  a  certain  definite  temperature  (p.  32),  w^hile  evaporation 
takes  place,  with  varying  activity,  at  all  temperatures  above  very 
low  ones.  Thus  mercury  evaporates  at  all  temperatures  above  — 10^. 
Nor  is  evaporation  limited  to  liquids.  Solids  also  give  off  vapor,  as 
ice  does  at  as  low  a  temperature  as  — 30°.  Liquids  which  evaporate 
readily,  as  alcohol,  chloroform,  ether,  are  distinguished  as  volatile 
liquids ;  while  liquids  which  do  not  evaporate,  like  the  fixed  oils  and 
glycerol,  are  called  fixed  liquids. 

Gases  and  Vapors. — ^All  ai^riform  bodies  have  been  converted 
into  liquids  under  the  combined  influence  of  cold  and  pressure. 

Aeriform  bodies  exist  in  two  conditions,  dependent  upon  the 
temperature.  For  each  gas  there  is  a  certain  temperature,  different 
for  different  gases,  at  and  below  which  the  gas  can  be  converted  into 
a  liquid  by  sufficient  increase  of  pressure,  without  further  lowering 
of  temperature,  but  above  which  no  amount  of  pressure  will  cause 
liquefaction.  That  temperature  is  called  the  critical  temperature. 
At  temperatures  above  their  critical  temperatures  aeriform  bodies  are 
gases,  below  that  temperature  they  are  vapors.  When  the  substance 
is  at  it  si  (critical  temperature  there  is  a  certain  definite  pressure 
which  will  cause  its  liquefaction,  which  is  called  its  critical  pressure. 
For  example:  the  critical  temperature  of  carbon  dioxid  is  31,1^,  and 
its  critical  pi*essure  75.56  atm. 


30  MANUAL    OP    CHEMISTRY 

When  a  liquid  is  heated  in  a  sealed  glass  tube  of  sufficient 
streng^tb  to  withstand  the  high  pressure  attained,  a  temperature  is 
finally  reached  when  the  liquid  disappears,  and  the  tube  is  filled 
with  its  vapor,  which,  having  the  same  volume  and  weight  as  the 
liquid,  also  has  the  same  density.  The  temperature  at  which  this 
occurs,  190°  for  ether,  is  clearly  the  critical  temperature  of  the 
substance,  which  is  therefore  also  called  its  absolute  boiling  point 
(p.  24),  and  the  pressure  in  the  tube  is  its  critical  pressure.  There  is 
also  necessarily  a  critical  density,  i.  e.,  the  weight  of  unit  volume  of 
the  substance  at  its  critical  temperature  and  pressure. 

Equilibrium  between  Vapors  and  Liquids. — The  term  ^*  equi- 
librium" is  used  here,  and  in  general  in  chemistry  and  chemical 
physics,  to  indicate  a  condition  corresponding  to  the  mechanical 
"stable  equilibrium,"  i.  e.,  a  condition  to  which  the  system  tends  to 
return  if  it  be  disturbed. 

The  dynamic  theory  of  heat  (p.  24)  assumes  that,  in  their  move- 
ments, the  molecules  may  be  projected  beyond  the  free  surface  of  a 
liquid,  into  a  confined  space  above,  and  that,  continuing  their  motion 
as  vapor  molecules,  they  finally  may  return  to  the  liquid.  The  con- 
dition of  equilibrium  does  not,  therefore,  imply  that  the  passage  of 
molecules  from  the  liquid  to  the  vapor  (evaporation)  has  ceased,  but 
that  equilibrium  is  established  when,  evaporation  and  condensation 
continuing,  the  same  number  of  molecules  pass  in  unit  time  from 
the  liquid  to  the  vapor,  and  in  the  reverse  direction.  The  condition 
is  one  of  dynamic,  not  of  static  equilibrium. 

If  a  few  drops  of  ether  be  introduced  into  a  barometric  vacuum, 
the  liquid  instantly  disappears,  the  mercury  falls  in  the  tube  through 
a  certain  distance,  and  the  space  is  completely  filled  with  ether  vapor. 
The  molecules  in  the  liquid  ether,  by  reason  of  their  motion  (p.  25), 
are  therefore  under  a  certain  tension  or  pressure,  which  causes  them 
to  assume  the  form  of  vapor  when  external  pressure  is  released.  In 
this  condition,  i.  e.,  in  the  absence  of  any  excess  of  liquid,  the  vapor 
is  said  to  be  unsaturated,  and  it  then  behaves  like  a  gas,  and  its 
volume  is  inversely  proportionate  to  the  pressure  it  sustains. 

If  four  barometer  tubes,  containing  barometric  vacua  and  main- 
tained at  the  same  temperature,  be  taken  and  a  small  quantity  of 
different  volatile  liquids  introduced  into  each,  depressions  of  the 
mercury  will  be  observed  in  all,  but  they  will  not  be  equal.  There- 
fore the  vapor  tensions  of  different  liquids  differ. 

If,  now,  further  quantities  of  the  several  liquids  be  introduced, 
they  continue  to  volatilize,  and  the  mercury  continues  to  fall,  until 
a  certain  level  is  reached,  differing  with  the  several  liquids,  when 
the  depression  ceases,  and  at  the  same  time  an  excess  of  liquid 
remains  in  the  tube.    The  vapor  now,  in  the  presence  of  an  excess  of 


HEAT  31 

the  liquid,  is  said  to  be  saturated,  and  behaves  very  differently  from 
a  gas.  The  difference  between  the  height  of  the  mercury  in  the  tube 
and  that  of  the  barometer,  although  different  with  the  several  liquids, 
is  constant  for  each  liquid  at  a  constant  temperature,  and  is  the 
maximum  pressure,  or  vapor  tension  of  the  liquid. 

If,  in  place  of  introducing  different  kinds  of  liquid  into  different 
tubes,  maintained  at  the  same  temperature,  the  same  kind  of  liquid 
be  introduced  into  tubes  maintained  at  different  temperatures,  the 
depression  of  the  mercury  will  not  be  the  same  in  them.  Therefore, 
the  vapor  pressure  varies  at  different  temperatures  with  the  same  liquid. 
Thus  the  vapor  tension  of  water  is  4.6  mm.  at  0°,  and  525.5  mm.  at 
W;  that  of  ether  is  182.3  mm.  at  0°,  and  3898.0  mm.  at  90°. 

When  a  liquid  is  in  contact  with  its  saturated  vapor,  the  vapor 
tension  of  the  liquid  is  in  equilibrium  with  the  elastic  force  of 
the  vapor,  and  this  equilibrium  is  not  permanently  disturbed  by' 
change  of  volume;  for,  if  the  volume  be  diminished,  a  certain  quantity 
of  the  vapor  is  condensed  to  liquid,  and  if  the  volume  be  increased  a 
certain  proportion  of  the  liquid  is  vaporized,  and,  in  each  case,  in  such 
amount  as  to  maintain  the  pressure  constant  at  the  vapor  tension  of 
the  liquid  for  the  existing  temperature.  Saturated  vapors  do  not, 
therefore,  obey  the  Boyle -Mariotte  law.  If  a  saturated  vapor  be 
compressed,  a  portion  of  the  vapor  is  condensed,  and  if  the  pressure 
be  diminished,  a  portion  of  the  liquid  is  vaporized,  in  such  manner 
that,  the  temperature  remaining  constant,  the  elastic  force  and  the 
density  of  the  vapor  remain  constant.  The  passage  of  a  liquid  to 
the  form  of  vapor,  in  opposition  to  the  elastic  force  of  its  saturated 
vapor,  is  always  attended  by  absorption  of  heat,  and  the  perform- 
ance of  external  work,  as  is  the  case  in  a  steam  boiler. 

In  a  mixture  of  a  gas  and  a  saturated  vapor,  the  pressure  of  the 
mixture  is  equal  to  the  sum  of  the  pressures  which  each  would  exert 
if  it  occupied  the  space  alone.  Therefore,  when  a  liquid  is  vaporized 
into  an  indifferent  gas,  such  as  air,  evaporation  continues  until  the 
partial  pressure  (p.  20)  of  the  vapor  is  equal  to  the  vapor  tension 
at  the  existing  temperature.  (For  vapor  pressures  of  mixtures  of 
liquids,  see  p.  50.) 

When  two  communicating  vessels  are  each  partially  filled  with 
the  same  liquid  at  different  temperatures,  the  vapor  tension  is  the 
same  in  both  vessels,  and  is  that  corresponding  to  the  lower  tempera- 
tare.  Thus,  in  each  of  two  communicating  vessels  containing  water, 
one  at  0*^  and  the  other  at  100°,  the  vapor  pressure  is  4.6  mm., 
although  the  vapor  tension  of  water  at  100°  is  760  mm.  The 
tendency  to  restore  equilibrium  causes  rapid  evaporation  in  the 
warmer  vessel  and  condensation  in  the  cooler,  and  is  utilized  in  the 
process  of  distillation.   The  passage  of  a  vapor  to  the  form  of  liquid, 


32  MANUAL    OF    CHEMISTRY 

effected  as  above  indicated,  or  by  increase  of  pressure,  is  called 
condensation. 

Solutions  of  non- volatile  solids  have  lower  vapor  pressures  than 
the  pure  solvent,  and  the  amount  of  the  depression  is  proportionate 
to  certain  weights  of  the  solute  (p.  68). 

It  is  apparent  that  evaporation  is  favored  by  increase  of  tem- 
perature, by  diminution  of  pressure,  and  by  removal  of  the  vapor. 

Boiling. — When  heat  is  added  to  a  liquid  its  vapor  pressure 
increases  as  the  temperature  rises,  until  it  equals  the  pressure  sup- 
ported by  the  liquid,  when,  being  in  equilibrium  with  the  external 
pressure,  it  can  rise  no  further,  and  the  temperature  also  remains 
stationary.  Heat  now  added,  whatever  its  intensity,  ceases  to 
increase  the  temperature,  but  does  work  in  causing  the  liquid  to 
boil.  The  stationary  temperature  of  a  liquid  boiling  at  76  cm.  of 
atmospheric  pressure  is  its  boiling  point  (b.  p.).  It  is  always  the 
same  for  a  given  liquid,  but  differs  with  different  liquids,  and  is, 
therefore,  an  important  character  for  the  identification  of  liquids,  and 
as  a  test  of  their  purity. 

As  a  liquid  boils  when  its  vapor  pressure  equals  the  external 
pressure  which  it  sustains,  the  boiling  point  is  depressed  by  diminu- 
tion of  external  pressure,  and  raised  by  its  increase.  Thus  the  vapor 
tension  of  water  is  92  mm.  at  50°,  760  mm.  at  100°,  and  2  atm. 
(1520  mm.)  at  120.6°:  These  temperatures  are,  therefore,  the  boil- 
ing points  of  water  at  the  corresponding  pressures.  The  distillation 
of  liquids  at  reduced  pressures  is  frequently  resorted  to,  to  avoid 
chemical  actions  which  would  take  place  at  or  below  the  boiling 
point,  but  not  at  the  lower  temperature  attained  by  reducing  the  pres- 
sure; and  liquids  may  be  caused  to  exert  certain  actions  above  their 
boiling  points,  which  they  would  not  cause  at  lower  temperatures,  by 
heating  them  under  pressure. 

As  boiling  under  standard  atmospheric  pressure  occurs  only  when 
the  vapor  pressure  of  the  liquid  attains  76  cent.,  any  cause  which 
produces  diminution  of  the  vapor  pressure  delays  boiling,  and  raises 
the  boiling  point.  Such  a  cause,  we  have  seen,  exists  in  the  solution 
of  non-volatile  solids  in  the  liquid,  and,  therefore,  such  solutions 
have  higher  boiling  points  than  the  pure  solvents.     (See  p.  68). 

Sublimation. — Solids,  like  liquids,  have  vapor  pressures  which 
vary  with  the  temperature.  With  most  solids  this  pressure  is 
extremely  low  at  ordinary  temperatures,  but  with  others  it  attains 
the  normal  atmospheric  pressure  at  temperatures  not  far  removed 
from  the  fusing  point  of  the  solid.  Solids  of  the  latter  class,  such  as 
lodin  and  camphor,  give  off  vapor  at  ordinary  temperatures,  as  do 
liquids  below  their  boiling  points,  and  these  vapors  condense  in  part 
to  solids  upon  the  walls  of  a  closed  containing  vessel.   The  solids  are 


HEAT 


33 


I 


then  said  to  sublime,  and  the  condeased  solid  is  called  a  sublimate, 
ar,  if  in  crystalJiae  powder,  flowers.  The  temperature  at  which  the 
vapor  pressure  of  a  solid  equals  the  normal  atmospheric  pressure/ 
corresponding  to  the  boiling  point  of  a  liquid,  is  called  ils  sublima* 
tion  point,  and  is  usually  above  its  fusing  point.  Should  it  be  lower 
than  the  fusing  point,  the  solid  could  not  be  fused,  except  under 
increased  pressure. 

Heat  of  Vaporization. — We  have  seen  that  a  liquid,  in  passing 
to  the  form  of  vapor,  absorbs  a  definite  amount  of  heat,  the  tempera- 
ture remaining  constant  the  while.  The  amount  of  heat,  expi-essed 
in  calories,  so  required  to  convert  one  gram  of  the  liquid  into  vapor, 
at  the  same  temperature  as  the  liquid,  is  its  heat  of  vaporisation^  or 
latent  heat  of  vapor  (p.  26) »  It  varies  with  the  temperature,  and, 
for  all  liquids,  diminishes  with  increase  of  temperature.  Thus,  the 
heat  of  vaporization  of  water  is  606.5  ca!.  at  0*^,  and  535.9  cah  at 
100°,     (Seep.  22 J 

During  condensatiou,  a  vapor  liberates  an  amount  of  heat  equal 

to  that  which  it  absorbs  w^heu  vaporized  at  its  boiling  point.    This 

fact  is  utilized  to  transmit  heat  from  one  point  to  another  l^y  steam. 

Specific  Heat. — Equal  weights  of  all  substances  have  not  the 

same  thermal  capacity,  or  capacity  for  heat.  Or,  differently  expressed, 

it  requires  different  amounts   of  heat  to  raise    the  temperature  of 

equal  weights  of  different  substances  through  the  same  number  of 

degrees.    Thus,  if  equal  weights  of  water  and  of  mercury,  both  at  0°, 

illy  exposed  to  the  same  source  of  heat,  wiien  tke  water  has 

a  temperature  of  1"^,  the  mercury  will  have  a  temperature  of 

39*,  It,  therefore,  requires  30  times  as  much  heat  to  raise  unit 
weight  of  water  through  1^  as  it  does  to  raise  the  temperature  of  an 
eqnal  weight  of  mercury  equally.  The  unit  of  specific  heats  is  the 
kent  capacity  of  water,  i.  e.,  the  calorie  (p.  22),  which  is  the  amount 
of  beat  required  to  raise  the  temperature  of  one  gram  of  water  from 
i^  to  5'.    Thus  the  specific  heat  of  mercury  is  iiV=^  0.0333. 

It  follows  from  the  gas  law  (p.  58)  :  vp  =  RT,  that  if  the  tem- 
perature of  a  given  weight  of  gas  be  changed,  either  the  volume  or 
the  pressure  must  also  change.  One  factor  may,  however,  be  main- 
lined constant,  and  it  is  not  immaterial  in  the  determination  of  the 
•pacific  heats  of  gases  which  one  is  selected.  For  experimental 
(Miona  it  is  usually  the  specific  heat  at  constant  pressure,  Cp,  which 
it  determined.  If  the  determination  be  made  at  constant  volume,  e„, 
tbe  results  are  uniformly  lower,  owing  to  the  rise  of  temperature  pro* 
iuoed  by  the  increased  pressure  required  to  maintain  the  constant 
▼okme.  The  ratio  between  these  two  specific  heats:  T^==k,  is  differ- 
«it  with  different  gases.  It  is  L4016  for  air,  and  less  than  L667 
to  all  gases  examined. 


M  MANUAL   OP   CHEMISTRY 

LIGHT. 

• 

The  index  of  refraction  of  substances,  particularly  of  oils  and 
aromatic  organic  liquids,  is  frequently  utilized  for  their  identifica- 
tion,  and  has  furnished  data  for  the  determination  of  their  molecu- 
lar structure.  The  index  of  i-efraction  is  the  ratio  between  the  sine 
of  the  angle  of  incidence  and  the  sine  of  the  angle  of  refraction: 
n  =  *{^i  and  is  determined  with  an  instrument  called  a  refracto- 
meter,  or  with  a  suitably  constructed  spectrometer.  As  the  index 
of  refraction  varies  with  the  kind  of  light  used,  and  with  the  sp. 


gr.,  therefore  with  the  temperature,  yellow  (sodium)  light  is  used^ 
and  the  temperature  at  which  the  determination  is  made  is  noted 
in  brackets.  The  symbol  n  p  is  used  to  indicate  the  index  of  refrac- 
tion for  sodium  light. 

Spectroscopy. — A  beam  of  white  light,  in  passing  through  a 
prism,  is  not  only  refracted,  or  bent  into  a  different  i-ourse,  but  is 
also  dispersed,  or  divided  into  the  different  colors  which  constitute 
the  soectrum  (Fig,  13).  The  red  rays  being  the  least  deflected  are 
the  least  refrangible,  the  violet  rays  being  the  most  deflected  are 
the  most  refrangible. 

A  spectrum  is  of  one  of  three  kinds:  1.  Continuous,  consisting 
of  a  continuous  band  of  colors:  red,  orange,  yellow,  green,  blue, 
cyan-blue,  and  violet.  Such  spectra  are  produced  by  light  from 
white-hot  solids  and  liquids,  from  gas-light,  candle-light,  lime-light, 
and  electric  light.  2.  Bright-line  spectra,  composed  of  brisrht  lines 
upon  a  dark  ground,  are  produced  by  glowing  vapors  and  gases. 
3.  Absorption  spectra  consist  of  continuous  spectra.  »*msseil  by 
dark  lines  or  bands,  and  are  produced  by  light  paSv^ins  fhii>nsrh  a 
»>lid,  liquid,  or  gas,  capable  of  absorbing  certain  rays.  Examples 
of  bright-line  and  absorption  spectra  are  shown  in  Fig.  14,  p.  35. 


LIGHT 


35 


The  spectrum  of  sunlight  belongs  to  the  third  class.  It  is  not 
continuous,  but  is  crossed  by  a  great  number  of  dark  lines,  known 
a8  Fraunhofcr's  lines,  the  most  distinct  of  which  are  designated  by 
lettere  (No.  1,  Fig.  14). 

The  spectroscope  eonsists  of  four  essential, parts:  1st,  the  slit, 
a.  Pig.  15,  p.  36;   a  linear  opening  between  two  accurately  straight 


B«d.    Onuice,    YeUow.      Greeo. 


Glufi. 


Cyan- 
blue.    Violet 


FlO.  14,     I,  Soiw  ipectrum:   10  ftiirl  U,  Aii*drT*lloii  iispeetrft. 

and  parallel  knife-edges.  2d,  the  coUiniating  lens,  6;  a  biconvex  lens 
ID  who8c  principal  focus  the  slit  is  placed,  and  whose  olgect  it  is  to 
render  the  rays  tVoni  the  stit  parallel  hcmre  they  enter  the  prism. 
3d,  the  prism,  or  prisms,  r,  of  dense  glass,  usiinny  of  60^ ,  and  so  placed 
that  its  refracting  edge  is  paralli^I  to  the  slit.  4th.  nii  nliservinsr 
teleficope,  d,  so  arranged  as  to  receive  the  i-ays  as  they  emerge  from 


36 


MANUAL    OF   CHEMISTRY 


the  prisms*  Besides  these  parts  spectroscopes  are  usually  fitted  with 
some  arbitrary  graduation  ^  which  ser\'es  to  fix  the  location  of  lines 
or  bands  observed. 

In  direct  vision  spectroscopes  a  compound  prism  is  used,  so  made 
up  of  prisms  of  different  kinds  of  glass  that  the  emerging  ray  is 
nearly  in  the  same  straight  line  as  the  entering  ray. 

The  micro- spectroscope  (Fig.  16,  p.  37)  is  a  direct  vision  sx>ec- 
troscope  used  as  the  eye-piece  of  a  microscope.  With  it  the  spectm 
of  very  small  bodies  may  be  observed. 

As  the  spectra  produced  by  different  substances  ai^  characterized 
by  the  positions  of  the  lines  or  bands,  some  means  of  fixing  their 
location  is  required.     The  usual  method  consists  in  determining  their 

b 


FiG,  i;^ 


relation  to  the  principal  Fraunhofer  lines.  As,  however,  the  relative 
positions  of  these  lines  v^ary  with  the  nature  of  the  substance  of  which 
the  prism  is  made,  although  their  position  with  regard  to  the  colors 
of  the  speetrum  is  fixed,  no  two  of  the  arbitrary  scales  used  will  give 
the  same  reading. 

The  most  satisfactory  method  of  stating  the  positions  of  lines  and 
bands  is  in  wave-lengths.  The  lengths  of  the  waves  of  rays  of 
different  degrees  of  refrangibility  have  been  carefully  determined, 
the  unit  of  measurement  being  the  tenth -metre,  of  which  lO'** 
make  a  metre.  The  wave-lengths»=^,  of  the  principal  Fraunhofer 
lines,  are; 


A  ....  .  7604.00 

a 7185.00 

B  6867.00 

C  .  .  .  .  »  65S2.0I 


D  .  .  .  .  .  5B92.12 

E  6269.13 

b    5172.00 

F 4860.72 


G 4307.25 

H, 3968.01 

Ha 3933.00 


LIGHT 


37 


I 


The  scale  of  wave -lengths  can  easily  be  used  with  any  spectroscope 
liaving  ao  arbitrary  scale,  with  the  aid  of  a  cur%'e  constructed  by 
interpolation*  To  coostruct  siieh  a  eur^'Ci  paper  is  used  which  is 
ruled  into  sqnare  inches  and  tenths.  The  ordinates  are  marked  with 
a  scale  of  wave-lengths,  and  the  abscisses  with  tiie  arbitrary  scale  of 
the  instrument.  The  position  of  each  principal  Frauuhofer  line  is 
then  carefully  determined  in  terms  of  the  arbitrary  scale,  and  marked 
opon  the  paper  with  a  X  at  the  point  where  the  line  of  its  wave- 
length and  that  of  its  position  in  the  arbitrary  scale  cross  each  other. 
Throngh  these  X  a  curve  is  then  drawn  as  regularly  as  possible.  In 
noting  the  position  of  an  absorption -band,  the  position  of  its  centre 
in    the  arbitrary  scale  is   observed,  and   its  value  in  wave-lengths 

obtained  from  the  curve,  which,  of 
course,  can  only  be  used  with  the  scale 
and  prism  for  which  it  has  been  made. 
In  tlie  Zeiss  -  Abb/?  tn  ic  ros  pec  t  rose  ope 
(Fig.  16)  a  wave-length  scale.  Fig.  17, 
p,  38,  photographed  on  glass  and 
placed  at  N,  is  used  directly.  The 
numbers  on  the  scale  are  the  first  two 
figures  of  those  given  above. 

Polarimetry* — Light,  in  passing 
through  many  crystals  in  any  direction 
other  than  parallel  to  the  principal  axis 
(p.  14),  is  doubly  refracted,  or  bifurcated 
into  two  rays,  the  ordinary  and  extra- 
ordinary, of  equal  intensity.  In  then 
passing  through  a  second,  similar  crys- 
tal, these  rays  are  again  bifurcated, 
forming  four  rays,  which  are  of  equal 
iaten&ity  only  in  two  positions  of  the  second  crystal  with  reference 
to  the  first.  If  the  second  crystal  be  rotated  about  the  common  axis, 
two  of  the  rays  are  gradually  extinguished,  and,  on  further  rotation , 
they  reappear,  and  the  other  two  are  extinguished.  The  light  in 
(laisitig  through  the  first  crystal  has,  therefore,  been  modified  in  such 
manner  that  the  second  crystal  is  opaque  to  the  ordinary  ray  in  one 
position,  and  to  the  extraordinary  ray  in  a  position  opposite  to  the 
first*  Light  so  modified  is  said  to  be  polarized,  and  the  first  rryptal 
b  called  the  polarizer,  and  the  second  the  analyzer.  A  Nicol's  prism 
k  a  cr>^6tal  of  Iceland  spar,  so  cut  that  it  extinguishes  the  ordinary 
niy,  transmitting  only  the  extraordinary. 

If,  when  the  polarizer  and  analyzer  are  so  adjusted  as  to  extin- 
guijsh  a  ray  passing  through  the  former,  certain  substances  are 
broQgbt  between  them,  light  again  passes  throngh  the  analyzer;  and 


Fto    10, 


38 


MANUAL    OF    CHEMISTBT 


in  order  again  to  produce  extinction,  the  analyzer  must  be  rotated 
upon  the  axis  of  the  ray  to  the  right  or  to  the  left.  Substanc-es 
capable  of  thus  influencing  polarized  light  are  said  to  be  optically 
active.  If,  to  produce  extinction,  the  analyzer  is  turned  in  the  direc- 
tion of  the  hands  of  a  watch,  the  substance  is  said  to  be  dextrogyrous; 
it  in  the  opposite  direction,  IcevogyrGus. 

The  distance  through  which  the  analyzer  must  be  turned  depends 
upon  the  peculiar  power  of  the  optically  active  substance,  the  length 
of  the  column  interposed,  the  concentration,  if  in  solution,  and  the 
wave-length  of  the  original  ray  of  light.  The  specific  rotary  power 
of  a  substance  is  the  rotation  produced,  in  degrees  and  tenths,  by 


a 

B  C 

D 

1 

Bb 

P 

G 

. 

1 

niv 

dj     65 

«>; 

5S    !  i    a 

1  ;           % 

• 

40 

'1 , 

'f 



V  1 

1 

I  1 

1 

1 

J 

. 

!. 

FlO.  17. 


one  gram  of  the  substance,  dissolved  in  one  cubic  centimetre  of  a 
non -active  solvent,  and  examined  in  a  column  one  decimetre  long. 
The  specific  rotary  power  is  determined  by  dissolving  a  known 
weight  of  the  substance  in  a  given  volume  of  solvent,  and  observ- 
ing the  angle  of  rotation  produced  by  a  column  of  given  length. 
Then  let  p  =  weight  in  grams  of  the  substance  contained  in  1  cc. 
of  solution;  I  the  length  of  the  column  in  decimetres;  a  the  angle 
of  rotation  observed;    [a]  the  specific  rotary  power  sought,  we  have 


[a]  = 


pL 


In  most  instruments  monochromatic  light,  corresponding  to  the  D 
line  of  the  solar  spectrum,  is  used,  and  the  specific  rotary  power  for 
that  ray  is  expressed  by  the  sign  [^/Jd.  The  fact  that  the  rotation 
is  right-handed  is  expressed  by  the  si^n  -f,  and  that  it  is  left-handed 
by  the  sign  — . 

It  will  be  seen  from  the  above  formula  that,  knowing  the  value 
of  [a]D  for  any  given  substance,  we  can  determine  the  weight  of 
that  substance  in  a  solution  by  the  formula 


WdXT 


ELECTBICITY  39 

The  polarimeter  or  saccharometer  is  simply  a  peculiarly  con- 
structed polariscope,  used  to  determine  the  value  of  a. 

Chemical  effects  of  light. —  Many  chemical  combinations  and 
decompositions  are  much  modified  by  the  intensity,  and  the  kind 
of  light  to  which  the  reacting  substances  are  exposed.  Hydrogen 
and  chlorin  gases  do  not  combine,  at  the  ordinary  temperature,  in 
the  absence  of  light;  in  diffused  daylight  or  gaslight,  they  unite 
slowly  and  quietly;  in  direct  sunlight,  or  in  the  electric  light, 
they  unite  suddenly  and  explosively.  The  salts  of  silver,  used  in 
photography,  are  not  decomposed  in  the  dark,  but  are  rapidly 
decomposed  in  the  presence  of  organic  matter,  when  exposed  to 
sunlight. 

The  chemical  activity  of  the  different  colored  rays  of  which 
the  solar  spectrum  is  composed  is  not  the  same.  Those  which  are. 
the  most  refrangible  possess  the  greatest  chemical  activity  —  the 
grreatest  actinic  power.  The  visible  solar  spectrum  represents 
only  about  one -third  of  the  rays  actually  emitted  from  the  sun. 
Two -thirds  of  the  spectrum  are  invisible  as  light,  and  are  only 
recognizable  by  their  heating  effects,  or  by  chemical  decomposi- 
tions which   they  provoke. 


ELBCTBICITY. 

Certain  substances,  such  as  amber,  glass,  sealing-wax,  when 
rubbed  with  silk,  flannel,  etc.,  acquire  the  power  of  attracting  light 
bodies.    They  are  then  said  to  be  electrified. 

If  a  glass  rod  be  rubbed  with  silk  and  approached  to  a  pith  ball 
suspended  by  a  silk  thread  from  a  glass  support,  the  pith  ball  is 
first  attracted,  and,  after  a  short  contact  with  the  glass,  is  then 
repelled.  The  pith  ball  has  become  electrified  by  contact  with  the 
glass,  and  in  this  condition  the  two  bodies  repel  each  other.  But  if 
now  a  rod  of  sealing-wax  be  rubbed  with  flannel  and  approached  to 
the  electrifled  pith  ball,  the  rod  will  attract  the  ball.  In  this  state  the 
ball  is  repelled  by  the  electrifled  glass,  and  attracted  by  the  electrifled 
sealing- wax.  And,  similarly,  a  pith  ball  electrifled  by  contact  with 
the  electrifled  sealing-wax  will  be  repelled  by  the  wax  and  attracted 
by  the  glass  rod.  There  are,  therefore,  two  kinds  of  electricity,  one 
generated  in  glass  by  friction  with  silk,  called  vitreous  or  positive 
(  +  )  electricity,  the  other  generated  in  sealing-wax  by  friction  with 
flannel,  called  resinous,  or  negative  ( — )  electricity. 

Bodies  similarly  electrified  repel  each  other,  and  bodies  differently 
tUrfrified  attract  each  other. 

Insulators — Conductors— Ions.— If  two  metal  spheres,  supported 


40 


MANUAL  OP    CHEMISTRY 


upon  glass  rods,  and  placed  about  a  foot  apart,  be  charged,  one  with 
positive,  and  the  other  with  negative  electricity,  the  spheres  will 
attract  each  other,  but  each  will  retain  its  charge  in  dry  air.  If,  now, 
a  glass  rod  be  brought  in  contact  with  both  spheres  at  the  same  time, 
each  still  retains  its  charge  as  before.  But  if  a  brass  rod  be  used  in 
place  of  the  glass  one,  the  positive  and  negative  electricities  neu- 
tralize each  other,  and  both  spheres  lose  their  charges.  Glass  is  an 
insulator,  or  non-conductor  of  electricity;  brass  is  a  conductor. 
Conductors  are  of  two  kinds:  Conductors  of  the  first  order,  such  as 
metals,  conduct  electricity  without  themselves  suflfering  any  change, 
except  elevation  of  temperature.  Conductors  of  the  second  order, 
such  as  solutions  of  salts,  are  substances  from  which  their  con- 
stituents are  separated  by  the  passage  of  electricity  through  them. 
The  constituents  which  are  thus  separated  from  a  conductor  of  the 
second  order  are  called  ions  (pp.  43, 72) .  Another  distinction  between 
'the  two  orders  of  conductors  is  that  with  those  of  the  first  order  elec- 
trical energy  only  is  transported,  while  with  those  of  the  second  order 
matter  (the  tons)  is  also  transported. 

Galvanic  Electricity. — The  kinetic  energy  (p.  8)  which  is  devel- 
oped in  chemical  solution  of  a  metal  (p.  27)  is  manifested  in  part  as 
heat,  but  also  in  great  part  in  charging  the  metal  with  negative 
electricity,  and  the  solvent  with  positive  electricity.    Thus,  if  a  plate 


Zn 

+• 

— 

+  - 

■+ 

+ 

— 

+  - 

,+ 

+ 

— 

4-   - 

■-f 

+ 

— 

+   - 

+ 

Zn 

Cn 

+ 

— 

-{ — 

+ 

— 

+ 

— 

-t-  - 

+ 

— 

+ 

— 

+    - 

+ 

— 

+ 

— 

+  - 

+ 

— ' 

FiO.  18. 


FiO.  19. 


of  pure  zinc  be  immersed  in  pure  dilute  sulfuric  acid,  the  metal 
becomes  charged  with  negative  electricity,  and  at  the  same  time  a 
part  of  the  zinc  goes  into  solution,  its  ions  carrying  a  positive  charge 
to  the  surrounding  liquid  (Fig.  18).  This  action  continues  for  a 
very  short  time,  until  the  electric  charge  so  produced  balances  the 
"solution  pressure"  of  the  metal,  i.  e.,  its  tendency  to  dissolve 
(p.  70),  when  all  action  ceases.  If,  now,  a  plate  of  pure  copper  be 
also  immersed  in  the  acid,  the  solution  pressure  of  this  metal  being 
extremely  small,  the  copper  simply  becomes  charged  with  positive 
electricity,  and  the  surrounding  liquid  with  negative  electricity;  but 
no  further  solution  of  the  zinc  occurs  (Fig.  19).    If,  now,  the  two 


ELECTRICITY 


41 


+ 


Fj.j.  2iJ. 


metal  plates  be  connected  by  a  conducting  wire,  the  negative  elec- 
tricity of  the  zinc  and  the  positive  of  the  copper  neutralize  each  other 
along  the  conductor  (Pig.  20),  the  electric  charges  of  the  liquid 
reoombitie,  and  solution  of  the  zinc  again  begins,  attended  by  the 
Seoeration  of  constantly  renewed  electric  charges,  which  constantly 
tend  to  neutralize  each  other,  producing  an  electric  current,  which 
consists  of  the  passage  of  positive 
electricity  in  one  direction,  and  of 
negative  electricity  in  the  opposite 
direction. 

An  arrangement  of  metals  and 
olvent  such  as  that  deseribed  is 
called  a  galvanic  cell  or  element, 
and  a  combination  of  two  or  more 
is  a  galvanic  battery. 

An  electric  current  is  produced 
whenever  two  metals,  or  a  metal 
and  another  conducting  solid,  are 
immersed  in  a  liquid  in  which  the 

two  solids  have  different  solution  pressures,  or  when  two  plates  of 
the  same  kind  of  metal  are  immersed  in  two  liquids  in  which  the 
metal  has  different  solution  pressures,  and  either  floated  one  upon 

^the  other,  or  separated  only  by  a  porous  diaphragm.  The  metal 
faaTing  the  higher  solution  pressure  is  the  one  which  is  dissolved  in 
the  action  of  the  galvanic  element,  and  hence  is  the  position  of 
higher  potential  (p.  8).  The  other  plate  is  the  position  of  lower 
potential.  Any  wires  or  other  conductors  attached  to  the  plates  are 
called  poles,  or  leads,  or  electrodes.  The  entire  system  of  solvent, 
plates  and  outside  conductors  is  called  an  electric  or  galvanic  circuit. 
The  circuit  is  said  to  be  closed  when  there  is  no  break  in  its  con- 
tinnity,  and  the  current  is  free  to  pass.  It  is  said  to  be  open  when 
there  is  an  interruption  in  its  continuity,  when  the  current  ceases 
to  pass. 

The  positive  electrical  current  originates  at  that  plate  haviog  the 
eater  solution  pressure,  i.  e.,  the  higher  potential  (the  zinc  plate, 
'ig*  20),  which  is  therefore  called  the  generating,  or  positive  plate. 
It  flows  through  the  liquid  in  the  cell  to  the  plate  of  lower  iiotential 
(the  copper  plate),  which  is  therefore  called  the  collecting,  or  nega- 
tive plate.  From  the  colleetiug  plate  the  current  passes  through  the 
outside  conductors  of  the  circuit  toward  the  generating  plate.  As 
the    positive    current    leaves    the   cell    from    the   negative  plate,  the 

^electrode  connected  with  that  plate  is  of  higher  potential  than  that 
Dnnected  with  the  generating  plate,  and  therefore  we  have  the 
pparent  anomaly  that  the  pole  connected  with  the  negative  plate  is 


42  MANUAL   OP    CHEMISTRY 

called  the  positive  pole,  or  the  anode,  while  the  pole  connected  with 
the  positive  plate  is  called  the  negative  pole,  or  the  cathode,  or 
kathode.  The  positive  current,  therefore,  passing  from  the  position 
of  higher  potential  to  that  of  lower  potential,  in  many  respects 
resembles  the  flow  of  water  from  a  higher  to  a  lower  level,  or  the 
passage  of  heat  from  a  higher  to  a  lower  temperature.  The  negative 
current,  on  the  other  hand,  passes  from  lower  to  higher  potential. 
The  total  current  is  the  sum  of  the  passage  of  positive  charges  in  one 
direction  and  of  negative  charges  in  the  opposite  direction. 

Electromotive  Force — Quantity— Resistance. — As  the  galvanic 
current  is  produced  by  the  difference  of  solution  pressures  in  the 
solvent,  or  activating  liquid,  of  the  substances  composing  the  two 
plates,  the  greater  this  difference,  which  constitutes  the  difference  of 
potential  or  electromotive  force,  or  voltage  (E.  M,  F.,  or  E.)  of  the 
system,  is,  the  greater  will  be  the  quantity  of  electricity  produced, 
and  consequently,  other  things  being  equal,  the  greater  will  be  the 
strength  or  intensity  of  the  current,  i.  e.,  the  quantity  of  electricity 
passing  a  given  point  in  unit  time. 

We  have  seen  that  some  substances  conduct  electricity,  while 
others  do  not.  Conductors  also  differ  in  the  degree  of  facility  with 
which  they  allow  the  current  to  pass  through  them  when  they  are  of 
equal  length  and  of  equal  cross -section.  The  resistance  of  a  con- 
ductor is  the  degree  of  opposition  which  it  offers  to  the  passage  of 
the  current,  and  the  complement  of  the  resistance  is  the  conductance 
of  the  conductor.  Resistance  and  conductance  are  clearly  inversely 
proportionate  to  each  other.  They  depend  upon  four  factors:  1.  The 
special  property  of  conductivity  of  the  material;  2.  The  length  of 
the  conductor;  3.  Its  cross  section;  4.  The  temperature.  The 
resistance  is  directly  as  the  length,  and  inversely  as  the  cross -section 
of  the  conductor.  With  metals  it  is  increased,  and  with  salt  solutions 
it  is  diminished  by  elevation  of  temperature.  In  considering  the 
resistance  of  a  galvanic  circuit  we  have  to  deal  with  both  internal 
resistance,  i.  e.,  that  of  the  liquid,  or  liquids,  and  plates  composing 
the  elements,  and  external  resistance,  i.  e.,  that  of  the  conducting 
system  outside  of  the  battery. 

The  specific  resistance,  or  resistivity,  of  a  substance  is  the 
resistance  which  is  offered  by  a  column  of  the  substance  one  meter 
long  and  1  sq.  mm.  in  cross -section.  Thus,  if  the  resistivity  of  pure 
copper  be  taken  as  100,  that  of  silver  is  94.1,  that  of  platinum  is  567, 
and  that  of  mercury  is  5953.3.  The  specific  conductance,  or  con- 
ductivity (k)  of  a  substance,  is  the  conductance  of  a  column  of  the 
substance  one  centimeter  long  and  1  sq.  em.  in  cross -section. 

Ohm's  Law. — This  fundamental  eitipirieal  law  is  to  the  effect 
that:     The  current  strength  is  directly  proportionate  to  the  electro- 


ELECTRICITY  43 

motive   force,    and    inversely    proportionate    to   the   resistance.     Or: 

E  E 

C  =  -j^,  and  conseqaeutly:  R  =  -^  ,  and  E  =  RC,  also. 

Fall  of  Potential— Potential  Gradient— Current  Density. — ^As 
the  positive  current  flows  from  the  position  of  higher  to  that  of 
lower  potential,  the  potential  difference  is  a  constantly  diminishing 
quantity;  as  is  the  ^^head  of  water''  under  like  conditions.  This 
diminution  is  referred  to  as  the  fall  of  potential,  in  like  manner  as 
we  speak  of  a  ^^fall  of  temperature.''  The  amount  of  this  fall,  in 
units  of  electromotive  force  per  centimeter  of  conductor,  is  called  the 
potential  gradient.  It  is  determined  by  dividing  the  current  density 
by  the  conductivity. 

In  an  electric  circuit  the  current  is  the  same  in  every  cross -section 
of  the  circuit,  whether  its  several  parts  be  of  uniform  or  of  varying 
resistivity.  Consequently,  if  the  cross-section  of  a  portion  of  a  uni- 
form conductor  be  diminished,  a  larger  quantity  of  electricity  will 
have  to  pass,  per  unit  of  area  of  section,  in  the  constricted  part 
than  in  the  wider  part  of  the  conductor.  The  current  density  is  the 
current,  in  units  of  current  strength,  per  sq.  cm.  of  cross -section  of 
conductor. 

Divided  Currents. — If  a  conductor  be  divided  into  two  branches 
which  are  subsequently  reunited  at  another  point,  and  if  the  resist- 
ances of  the  two  branch  conductors  be  equal,  each  will  carry  one- 
half  of  the  current;  and,  if  the  resistance  of  one  branch,  A,  be  double 
that  of  the  other,  B,  A  will  carry  %  of  the  current  and  B  %:  If  a 
conductor  he  divided  info  two  or  more  branches  subsequently  reunited, 
the  current  is  divided  between  the  several  branches  in  inverse  ratio  to 
fheir  resistances. 

If  the  same,  undivided,  current  be  made  to  pass  successively 
through  two  or  more  pieces  of  apparatus;  lamps,  electrolytic  cells, 
etc.,  these  are  said  to  be  connected  in  series,  and  each  receives  the 
same  amount,  i.  e.,  the  whole  of  the  current.  If  two  or  more  pieces 
of  apparatus  be  introduced  in  the  course  of  as  many  branches  of  the 
current,  they  are  said  to  be  connected  in  parallel,  and  each  receives 
that  proportion  of  the  current  allowed  by  the  above  rule,  the  resist- 
ance of  the  apparatus  itself  entering  into  the  calculation. 

Electrolysis. — We  have  seen  (p.  40)  that  when  a  current  passes 
through  a  conductor  of  the  second  order  certain  constituents,  called 
ions,  are  separated  from  the  conductor.  This  occurs  with  all  liquids, 
whether  solutions  or  fused  solids,  which  are  conductors,  and  the 
process  is  called  electrolysis,  while  the  substance  acted  upon,  the 
conductor,  is  called  an  electrolyte.  The  ions  are  given  off,  one  at  each 
electrode,  and  entirely  unmixed  with  each  other.  Those  that  are 
given  oflf  at  the  positive  electrode,  or  anode,  being  attracted  thereby, 


44 


MANUAL    OF    CHEMISTRY 


are  charged  with  negative  electricity,  and  are  therefore  ekctroncga* 
tivc  ions,  or  anions  (  ai'a  =  iip,  '1(0  =  to  go).  Those  which  are  given 
off  at  the  negative  electrode,  or  cathode,  are  electropositive  ions, 
or  cations  ('caTa  =  down,  or  katioas).  Thus,  when  water  is  elee- 
trolyzed,  pure  hydrogen  h  given  off  at  the  negative  electrode,  and 
pure  otygen  at  the  positive  electrode;  and  when  hydroehlorie  acid 
solution  is  electrolyzed  pure  hydrogen  is  again  given  off  at  the  nega- 
tive electrode,  and  pure  chlorin  gas  at  the  positive.    (See  pp-62,  70). 

Polarization. — If  the  electrodes  of  a  battery  of  suflrcieut  electro- 
motive force  be  made  to  terminate  in  two  platinum  plates  which  are 
immersed  in  water  acidulated  with  sulfuric  acid,  the  positive  current 
passes  from  that  platinum  plate  which  is  the  anode  to  that  which  is 
the  cathode,  and  oxygen  is  separated  at  the  former  and  hydrogen  at 
the  latter.  By  adherence  and  penetration  of  these  gases  one  platinum 
electrode  becomes,  to  a  greater  or  lesser  extent,  practically  an  oxygen 
plate  and  the  other  a  hydmgen  plate,  and  if  now  the  connection  with 
the  battery  be  severed,  and  metallic  connection  made  between  the  two 
platinum  plates,  a  current  will  be  found  to  pass  in  the  opposite 
direction  to  that  of  the  battery.  This  current  is  called  a  polarization 
current,  and  the  electrodes  are  said  to  be  polarized.  This  polariza- 
tion  current  is,  of  course,  produced  even  when  the  electrodes  remain 
in  the  battery  circuit,  aud,  Howing  in  the  opposite  direction  to  the 
main  current,  tends  to  neutralize  and  weaken  the  latter.  The  accu- 
mulation of  gas,  or  deposition  of  metal  upon  the  plates  of  a  galvanic 
ceil  also  produces  a  polarization  current  in  the  battery  itself,  which 
is  one  of  the  causes  of  enfeeblement  of  a  non*  constant  form  of 
galvanic  element. 

Electrical  Units.^ — Quantitij, — ^In  accordance  with  a  law  discovered 
by  Faraday  (p.  71),  when  a  conductor  of  the  second  order  is  electro- 
lyzed by  the  passage  of  an  electrical  current  through  it,  the  quantities 
of  the  ions  separated  in  a  given  time  are  exactly  proportionate  to 
the  quantity  of  electricity  passing  through  the  conductor.  We  have 
therefore  in  the  mass,  or  weight,  of  some  selected  ion  separated  by  a 
current  in  unit  time  a  convenient  measure  of  electrical  quantity. 
The  unit  of  this  measure  is  called  the  Coulomb  (0),  which  is  the 
quantity  required  to  separate  0.0104  mgm.  of  hydrogen,  or  LI  175 
mgnis.  of  silver  in  one  second. 

Cttrrent  Strength. — This  is  the  quantity  of  electricity  passing 
through  a  conductor  in  unit  time.  The  unit  is  called  the  Ampere  (A)^ 
which  is  that  current  strength  which  carries  one  Coulomb  per  second. 
It  is  also  (below)  that  current  which  is  produced  by  an  electromotive 
force  of  one  volt  acting  through  a  resistance  of  one  ohm.  For  some 
purposes  the  ampere  is  inconveniently  large,  when  the  MiUiampere, 


or  ToVoT  ampfere,  is  used  as  the  unit. 


4 


A. 


ELECTRICITY 


45 


/ 


Voltameters  are  instruments  for  the  measurement  of  the  quantity 
(Coulombs)  of  electricity,  aad,  therefore,  also  of  the  current  streng^th 
(Amperes).  In  the  gas  voltameter  (Fig.  21)  the  mixture  of  hydrogen 
and  oxygen  (knaH*gas)  produced  by  the  electroly- 
sis of  dilute  sulfuric  acid  are  collected  together* 
and  the  coulombs  determined  from  their  united 
volume,  measured  iu  the  graduated  tube,  reduced 
to  normal  conditions.  A  current  of  one  ampere 
produces  10.44  cc.  of  knall-gas  per  minute.  The 
gas  voltameter  has  the  disadvantage  that  the 
platinum  electrodes  soon  become  polarized,  and 
the  back  cun-ent  is  a  source  of  error.  The  silver 
voltameter  gives  more  accurate  results*  It  con* 
sists  essentially  of  a  rod  of  pure  silver,  serving  as 
an  anode,  and  immei'sed  in  a  solution  of  silver 
cyanid  in  potassium  eyanid»  contained  in  a  plati- 
num or  silver  dish,  or  crucible,  which  constitutes 
the  cathode.  The  coulombs  or  amperes  are  calcu- 
lated from  the  weight  of  silver  deposited  upon  the 
cathode  in  a  given  time.  A  current  of  one  ampere 
deposits  .0671  gm.  of  silver  in  a  minute. 

Galvanometers  of  special  type,  called  am- 
meters (Fig.  22)  are  much  more  convenient  than 
voltameters,  as  the  ampil^res  are  rend  off  directly 
from  an  index  moving  over  a  graduated  scale. 

When  the  current  is  used  for  electrolysis^  in 
either  industrial  or  analytical  operations,  the  current  density  at  the 
electrodes  nuist  be  carefully  regulated.  It  is  the  ratio  of  the  current 
strength  to  the  surface  area  of  the  electrode  (p.  41),  and  is  expressed 
ia  terms  of  normal  density,  which  is  a  current  of  one  ampere,  and 
an  electrode  area  of  100  sq.  cent.,  expressed  by  the  symbol  NDioo, 

C  V  1CM1 

)Qal  to  — -g — -,  in  which  C  is  the  amperage,  and  S  the  electrode 

area.    The  current   density  is  the  same  at  the  two  electrodes  only 
when    these   have  equal  areas.     Sometimes    the   current   density  is 

expressed  in  terms  of  tlie  number  of 
amperes  per  square  decimeter  of  electrode 
surface,  expressed  by  the  symbol  D, 
equal  to  NDin^>o. 

Resistance  and  Conductance, — As 
mercury  is  easily  obtained  pure  and  has 
a  high  specific  resistance  (p.  42),  the 
unit  of  resistance  is  derived  from  that 
of  a  column  of  definite  magnitude  of  that 


FlO.  31. 


46  MANUAL    OP    CHEMISTRY 

metal.  The  Siemens'  unit  is  the  specific  resistance  of  mercury,  i.  e., 
the  resistance  at  0^  of  a  column  of  mercury  one  meter  long  and  1  sq. 
mm.  in  cross -section.  The  international  Ohm  is  now  in  more  general 
use,  and  is  the  resistance  at  0^  of  a  column  of  mercury  106.3  cent, 
long,  weighing  14.4521  gms.  and  having  a  uniform  cross -section, 
which  is  1  sq.  mm.  In  practice,  coils  of  insulated  wire  of  solid  metal, 
made  of  such  length  and  cross -section  as  to  equal  the  resistance  of 
the  above  standard,  ai'e  used.  The  Megohm,  for  the  measurement 
of  high  resistances,  is  1,000,000  ohms;  and  the  Microhm,  for  the 
measurement  of  small  resistances,  is  1660666  ohm. 

The  unit  of  conductance  is  the  Mho,  which  is  the  conductance  of 
a  body  having  the  resistance  of  one  ohm. 

Electromotive  Force. — The  unit  of  electromotive  force  is  the 
Volt  ( V) ,  which  is  that  electromotive  force,  which,  acting  steadily 
through  a  conductor  having  a  resistance  of  one  ohm,  will  produce  a 

current  of  one  ampere.   It  is  also  j^  of  the  electromotive  force  of  a 

normal  Clark  element,  functioning  at  15°;    or  j^jj  of    that    of    a 

normal  Weston  element  at  the  same  temperature.  . 

Voltmeters  are  galvanometers  of  high  resistance,  similar  in 
appearance  to  ammeters  (Fig.  22),  by  which  the  voltage  is  read  oflf 
directly  from  a  graduated  scale. 

Work — Heat— Power. — The  electrical  unit  of  work  or  heat  is 
the  volt :  coulomb,  which  is  the  work  done  or  heat  generated  by  one 
coulomb  over  a  fall  of  potential  of  one  volt.  One  volt  .-coulomb  i& 
equivalent  to  0.102  kg:m.,  and  to  0.24  therm. 

The  unit  of  electrical  power  is  the  Watt  (W),  or  volt: ampere^ 
i.  e.,  the  work  done  by  a  current  of  one  ampere  (one  coulomb  per 
second)  under  a  pressure  of  one  volt.  It  is  equal  to  yir  H.  P.,  or 
0.737  foot-pound  per  second,  and  to  tst  of  a  "force  de  cheval,"  or 
0.102  kg:m.  per  second. 

For  the  measurement  of  dynamo  currents  the  watt  is  too  small  a 
unit,  and  use  is  made  of  the  kilowatt  {Kw.),  or  1000  watts  as  the 
unit.  One  "electric  horse-power"  is  1.34  kilowatts,  and,  with  a 
pressure  of  100  volts  and  a  current  of  10  ampferes,  one  kilowatt  is 
equal  to  1.34  mechanical  horse -power. 

C,  G.  8,  Electric  Units.-— One  watt  being  equal  to  0.102  kg: m. 
per  second,  and  one  kg:m.  equal  to  9.81  X 10*^  ergs  (p.  8),  one  watt  ia 
equal  to  10^  ergs.  Prom  this  the  relation  of  other  "practical "  electri- 
cal units  to  C.  G.  S.  units  may  be  derived:  1  volt  =  %X10"2;  I 
ohm  =  viirX  10-« ;  1  amp&re  =  300  X 10"^ ;  and  1  coulomb  =  300 X 10^ 
electrostatic,  or  0.  6.  S.  units.  The  equivalents  in  electromagnetic 
units  are:  1  volt  =  108;  1  ohm  =  10»;  1  ampfere=10-^  and  1 
coulomb  =  10"^. 


CHEMICAL    PHENOMENA 


47 


CHEMICAL   PHENOMENA. 


Elements*^ — The  great  majority  of  material  substaaces  existing 
in  uatare,  or  produced  artificially,  may  be  so  decomposed  as  to  yield 
two  or  more  other  substances,  different  in  their  properties  from  tlie 
substance  from  which  they  originated^  and  from  each  otlxur;  and  in 
such  dacomposition  the  weight  of  each  of  the  products  separateb"  is 
less  than  that  of  the  original  substance,  which  latter  is,  however, 
equal  to  the  sum  of  the  weights  of  the  new  substances.  Thus,  if  we 
heat  216  grams  of  a  solid,  red  powder,  ujercuric  oxid,  it  disappears 
completeiy,  and  in  its  place  there  may  be  collected  16  grams  of  a 
colorless  gas,  and  2rX)  grams  of  liquid,  metallic  mercury.  Or,  if 
18.016  grams  of  water  be  decomposed  by  electrolysis,  there  may  be 
collected  16  grams  of  the  same  kind  of  gas,  oxygen,  as  was  obtained 
from  the  mercuric  oxid,  and  2.016  grams  of  a  mncb  lighter,  inflam- 
luable  gas,  hydrogen.  Although  mercury,  oxygen  and  hydrogen  may 
be  obtained  fi'om  many  sources,  they  have  never  been  split  np  to 
yield  two  other  dissimilar  substances.  They  are  simple,  or  elementary 
tBubstances,  or  elements:  i.e.,  fiubstftnres  whirh  eminot  by  any  fcn&wn 
neans  he  spift  up  htfo  ofhfr,  disisimUar,  mbsfanrfs, 

Alt  hough  hundreds  of  thousands  of  different  species  of  material 
substance  are  known  to  exist,  but  eighty  of  these  are  elements  (list 
p.  55:    see  also  p.  103). 

Non-elementary  Substances. — Mechanical  Mixtures,^ — All  mate* 
rial  substances  which  are  not  wholly  elementary  are  made  up  of 
elements,  or  compounds  (below),  or  both,  aggregated  together  in  one 
of  three  different  conditions:  as  mechanical  mixtures,  as  chemical 
compounds,  or  as  physical  mixtures  (p.  54). 

Speaking  strictly,  only  elementary  substances  are  homogeneonSt 
e.,  alike  in  all  their  parts,  down  to  the  most  minute  particles. 
beir  atoms.  Speaking  relatively,  mechanical  mixtures  are  hetero* 
geueoQSf  while  compounds  and  physical  mixtures  are  homogeneous. 

lu  mixtures,  whether  meehanieal  or  physical,  the  constituent 
ftubstances  retain  their  individual  properties  unaltered  in  kind,  and 
they  may  be  mingled  in  any  qnantitative  proportions,  except  that  in 
fiimple  solutions,  which  are  physical  mixtures,  such  proportions  are 
I'Oti fined  within  definite  limits.    Therein  they  differ  from  compounds. 

The  particles  of  which  a  mechanical  mixture  is  composed,  if 
snfRciently  different  in  appearance,  may  be  distinguished  from  each 
other  by  vision,  somelimes  with  the  unaided  eye.  as  the  particles  of 
Ifeldspnr.  mica  and  quartz,  of  which  granite  is  comt>osed,  or  micro- 
eopically,  as  the  particles  of  an  intimate  mixture  of  two  finely 
div^ided  powders  of  different  cohM*s.  The  ingredients  of  a  mechanical 
tDixtare  may  also  be  separated  from  each  other  without  the  expendi- 


48 


MANUAL   OF    CHEMISTRY 


tore  of  much  work,  by  physical  or  mechauical  means.    Thus,  the 

particles  of  iron  may  be  removed  with  a  magnet  from  the  most  inti- 
mate mixture  of  finely  powdered  iron  and  sulfur;  or,  the  ingredients 
of  a  medicinal  "  mixture  "  may  be  separated  by  the  centrifuge.  With 
mechanical  mixtures  chemistry  has  no  concern  until  after  their 
separation  into  their  constituents,  and  only  with  these  as  elements 
or  compounds. 

Compounds. — Many  substances,  when  examined  as  to  their  com- 
position, are  found  to  consist  of  two  or  more  elements,  always 
combined  in  the  same  proportion,  the  constituent  elements  differing 
essentially  in  their  properties  from  the  original  substance.  Such 
substances  are  chemical  compounds.  Thus,  when  water  is  decom- 
posed, as  by  electrolysis,  it  always  yields  88.81  per  cent,  by  weight, 
of  the  gaseous  supporter  of  combnstion:  oxygen,  and  11,19  per  cent 
of  the  inflaoimable  gas:  hydrogen.  And  when  common  salt  is 
decomposed  it  is  found  to  consist  of  39.4  per  cent  of  a  white,  soft, 
metal:  sodium,  and  60.6  per  cent  of  a  yellowish,  suffocating  gasi 
chlorin.  And  similarly,  a  vast  number  of  compounds  have  been 
examined  J  and  eacli  has  always  been  found  to  consist  of  the  same 
elements  in  the  same  proportions, 

These  facts  are  summarized  in  the  Law  o!  Definite  Proportions : 
The  reiatfve  tveights  of  thmentar^j  aubsfanees  in  a  compound  are  defi' 
nite  and  invanabh. 

But  something  more  than  a  definite  proportion  of  the  constituent 
elements  is  necessary  to  constitute  a  compound.  When  water  is 
electrolyzed,  and  the  products  are  collected  separately,  one  volume  of 
oxygen  is  obtained  for  every  two  volumes  of  hydrogen  {or  in  the 
proportions  by  weight  given  above) .  But  if  the  products  be  collected 
in  the  same  vessel  a  mixture  of  the  two  gases,  known  by  the  German 
name  of  "knall-gas,*'  is  obtained,  which  has  always  the  same  definite 
composition  as  the  water  from  which  it  was  derived.  But  if  equal 
weights  of  "knall-gas"  and  of  water  vapor  be  examined  they  will  be 
found  to  differ  widely  in  their  properties.  If  examined  at  110°  both 
will  have  the  same  appearance »  as  transparent,  colorless  gases,  and 
each  can  be  demonstrated  to  be  homogeneous.  But  if  they  be  cooled 
to  90*^,  the  water  vapor  will  condense  entirely  to  liquid  water,  while 
the  knall  -gas  will  remain  gaseous.  Or,  if  each  be  brought  into  a 
diffusion  apparatus  for  a  short  time,  at  a  temperature  maintained 
above  100°,  the  water  vapor  which  passes  through  will  be  identical 
in  every  respect  to  that  which  does  not,  while,  with  the  knall-gas, 
that  portion  of  the  gas  which  diffuses  will  exhibit  the  properties  of 
hydrogen,  while  that  which  does  not  will  have  the  properties  of 
oxygen.  Or,  if  an  electric  spark  be  passed  through  the  water  vapor 
and  through   the  knall -gas,  it  produces  a  violent  explosion  in  the 


I 
I 


I 


CHEMICAL    PHENOMENA 


49 


latter,  bat  no  effect  in  the  former.  The  knaJl-gas  is  a  physical  mix- 
ture of  hydrogen  and  oxygen,  the  vapor  of  water,  a  chemical  com- 
pound of  the  same  in  the  same  proportions.  The  compouftd  has 
properties  of  its  omi^  distinct  from  those  of  the  constituenf  elements. 

While  a  given  compound  alwaj's  contains  the  same  elements  in 
the  mme  proportions,  elements  may  combine  with  each  other  in  more 
than  one  proportion.  Thus  oxygen  and  nitrogen  combine  with  each 
other  in  five  different  ratios.  In  the  five  compounds  thus  formed  the 
two  elements  bear  to  each  other  the  following  relations  by  weight: 

In  the  first,  14  parts  of  nitrogen  to  8  of  orygen. 

In  the  second,  H  parts  of  nitrogen  to  8X2  —  16  of  oxygen* 

In  the  thif^,  14  parts  of  nitrogen  to  8X3  =  24  of  oxygen. 

In  the  fourth,  H  part  a  of  oitrogpn  to  8Xi  =  32  of  oxygen. 

In  the  fifth,  14  parts  of  nitrogen  to  SXS^'iO  of  oxygen. 

tod  similar  simple  ratios  are  found  to  exist  in  the  compounds  formed 
whenever  two  elements  combine  with  each  other  in  more  than  one 
ntio.  These  facts  are  generalized  in  the  Law  of  Multiple  Propor- 
tions: WJten  two  elements  eomhine  with  each  other  to  form  more  than 
me  compound,  the  resnlting  romitoitiifls  contain  simple  mnUiple  propor- 
tions  of  one  element  as  eompnrfd  with  a  constant  tiHatititfj  of  the  other*    I 

If  the  proportions  in  which  elements  comlnue  together,  in  accord- 
with  the  above  laws,  be  compared  with  each  other,  it  is  found 
that  the  mathematical  axiom  that  "Hiiugs  which  are  equal  to  the  same 
thiag  are  eqnal  to  each  other"  hcdds  good.  For  example:  70.9  parts 
of  chlorin  combine  with  40,1  parts  of  calcium,  and  16  parts  of 
oxygi^n  also  combine  with  40.1  parts  of  calcium;  therefore^  70.9  parts 
of  chlorin  combiue  with  IG  parts  of  oxygeu,  or  the  two  elements 
combine  in  the  proportion  of  some  simple  multiples  of  70.9  and  16. 
This  relation  is  expressed  in  the  Law  of  Reciprocal  Proportions: 
Tht  ptrndtrahle  quantities  tu  which  stth stances  unite  nith  the  same 
tub$iance  express  the  relation,  or  a  simple  mtdtiple  thereof,  in  which 
tkeif  unite  with  each  other.  This  law  applies  to  reactioos  between 
componnds  as  well  as  to  combinations  of  elements. 

Physical  Mixtures. — Mixtnres  of  gases»  of  vapors,  of  gases  and 
npors  (p.  29),  of  liquids,  and  sometimes  of  solids,  and  solutions,  are 
physical  mixtures.    They  differ  from  mechanical  mixtnres  in  that 

!j  are  homogeneous,  in  the  sense  that  the  proportions  of  the  con- 
itneats  are  the  same  in  all  parts  of  the  mixture;  and  in  that  the 
•eparation  of  the  constituents  of  a  physical  mixture  requires  the 
upenditure  of  a  notably  greater  amount  of  work  than  is  required  to 
product*  the  like  result  with  a  mechanical  mixture. 

Mixtures  of  gases  (p.  20}  and  of  unsaturated  vapors  (p.  30)  may 
he  made  in  any  proportions,  and  in  them  each  constitueat  retains  its 


50  MANUAL    OF    CHEMISTRY 

owu  properties  as  if  the  other  were  not  present.  The  mixing  is  not 
attended  by  elevation  of  temperature,  unless  there  be  chemical  action 
between  the  constituents,  when  the  temperature  usually  rises,  although 
in  some  cases  it  falls  (p.  97). 

Some  few  pairs  of  liquids  mix  together  in  all  proportions,  as  do 
alcohol  and  water,  or  ether  and  carbon  bisulfid.  But  more  usually 
there  is  a  limit  to  the  proportion  of  one  liquid  which  another  will 
dissolve.  If  small  proportions  of  ether  be  gradually  added  to  water 
and  the  mixture  be  agitated,  the  ether  at  first  dissolves  in  the  water » 
forming  a  homogeneous  liquid,  and  this  continues  until  the  water 
becomes  saturated  with  ether,  when  two  layers  appear,  the  lower 
water  saturated  with  ether,  the  upper  ether  saturated  with  water. 
On  further  addition  of  ether,  the  water  layer  diminishes  to  disap- 
pearance, during  which  time  the  condition  of  saturation  of  each 
liquid  with  the  other  persists.  On  continuing  the  addition  of  ether,  a 
more  and  more  dilute  solution  of  water  in  ether  is  obtained. 

The  adjective  "immiscible"  as  applied  to  two  liquids  is  not 
absolute,  but  is  used  in  speaking  of  two  liquids,  like  ether  and  water, 
which  separate  into  two  layers  after  agitation,  provided  one  be  not 
present  in  great  excess,  each  being,  when  so  separated,  a  saturated 
solution  of  the  other. 

Of  the  physical  properties  of  mixtures  of  liquids  only  one,  the 
mass,  is  strictly  "additive":  the  weight  of  a  mixture  is  the  sum  of 
the  weights  of  its  components.  The  quantitative  value  of  all  other 
physical  characters  of  a  mixture  of  liquids,  volume,  specific  gravity, 
specific  heat,  color,  refractive  index,  etc.,  vary  slightly,  but  only 
slightly,  from  the  algebraic  sum  of  those  of  the  constituents.  Thus, 
when  alcohol  and  water  are  mixed,  a  condensation  occurs,  which 
varies  in  amount  with  the  proportions,  and  is  at  the  maximum  with 
52.3  volumes  of  alcohol  to  47.7  volumes  of  water,  which  make,  not 
100  volumes,  but  96.35  volumes.  Frequently  a  physical  character 
possessed  by  a  liquid,  e.  g.,  specific  rotary  power,  is  modified  to  a 
varying  extent,  otherwise  than  by  mere  dilution,  by  admixture  of 
another  liquid  not  possessed  of  this  property.  Possibly  these  depar- 
tures depend  upon  the  occurrence  of  some  degree  of  chemical  combina- 
tion, as  would  appear  to  take  place  in  the  case  of  the  alcohol  and 
water  above,  in  which  the  proportions  named  are  about  those  which 
would  be  required  by  the  composition  of  one  molecule  of  alcohol  to 
three  molecules  of  water  (p.  52) ;  and  in  which  the  mixing  is  attended 
by  slight  elevation  of  temperature  (p.  98). 

The  vapor  pressure  of  a  mixture  of  two  liquids,  A  and  B, 
depends,  not  only  upon  the  vapor  pressures  of  two  liquids,  but  also 
upon  the  solubility  of  the  vapor  of  A  in  the  liquid  B,  and  that  of  the 
vapor  of  B  in  A.    When  the  two  liquids  are  practically  insoluble  in 


CHEMICAL    PHENOMENA  51 

each  other,  as  water  and  carbon  bisulfid,  the  vapor  pressure  of  the 
mixture  is  very  nearly  the  snm  of  the  vapor  pressures  of  the  con- 
stituents at  the  same  temperature.    When  the  two  liquids  are  soluble 
in  each   other  to  a  certain  degree,  as  ether  and   water,  the   vapor 
pressure  of  the  mixture  is  much  smaller  than  the  sum  of  those  of  the 
two  liquids.    In  the  case  of  ether  and  water  it  is  less  than  that  of  the 
ether  alone.    When  two  liquids  mix  in  all  proportions,  as  water  and 
alcohol,  the  vapor  pressure  of  the  mixture  is  intermediate  between 
those  of  the  constituents;   and  in  such  a  mixture  the  vapor  pressure, 
and  consequently  the  boiling  point,  varies  with  the  proportions  of 
the  two  constituents.    On  heating  such  a  mixture  at  constant  pres- 
sure, and   condensing   the   vapor   (distilling  it),  the   first   products 
condensed  will  contain  a  larger  proportion  of  the  more  volatile  con- 
stituent, and  the  less  volatile  will  accumulate  in  the  liquid  mixture, 
whose  vapor  pressure  will  therefore  fall,  and  whose  boiling  point  will 
consequently  rise.    This  is  taken  advantage  of  to  separate  two  liquids 
of  different  boiling  points  by  "fractional  distillation."    But  complete 
separation  by  this  means  is  possible  only  when  the  vapor  of  one 
liquid  is  readily  soluble  in  the  other  liquid,  but  the  vapor  of  the 
second  is  difficultly  soluble  in  the  first.    Only  in  this  case  is  the  fall 
of  vapor  pressure  continuous;  under  other  conditions,  the  variation  of 
vapor  pressure  is  not  represented  by  a  straight  line,  but  by  a  curve, 
ia  consequence  of  which  either  the  distillate  or  the  residual  liquid 
remains  a  mixture.    In  no  ease  can  separation  by  fractional  distilla- 
tion be  effected  with  any  degree  of  completeness  by  a  single  opera- 
tion; repeated  "fraetionings"  are  required. 

Mixtures  of  solids  are  usually  mechanical  mixtures  (p.  47),  but 
in  some  instances  tlie  particles  of  solid  mixtures  are  so  intimately 
intermingled  that  the  products  are  referred  to  as  solid  solutions. 
Indeed,  when  one  constitnerit  predominates  largely,  there  is  reason  to 
believe  that  "dissociation  "  may  occur,  as  in  dilute  liquid  solutions 
(p.  70) .  Isomorphous  mixtures  are  crystals  obtained  by  evapora- 
tion of  mixed  solutions  of  isomorphous  compounds  (p.  16),  such  as 
the  alums,  which  crystals  contain  the  several  salts,  homogeneously 
distribnted  throughout,  and  in  any  proportions.  Metallic  alloys, 
fflaRses.  and  probably  dyed  fibers  are  solid  solutions. 
For  liqnid  solutions,  see  pp.  27,  28. 

Combination  of  gaseous  elements  by  volume. — The  laws  of 
definite  proportions,  of  multiple  proportions,  and  of  reciprocal  pro- 
portions, also  known  as  the  laws  of  Richter,  Dalton  and  WenzeU 
respectively  (pp.  48,  49),  refer  to  proportions  by  weight  in  which 
♦elements  unite  to  form  compounds. 

When  the  proportions  by  volume  in  which  gaseous  elements  com- 
bine to  form  compounds  are  compared  with  each  other  and  with  the 


MANUAL   OF   CHEMISTRY 


volames  of  the  gases  produced,  all  at  the  same  temperature  and  pres- 
sure, simple  relations  are  also  found  to  exist,  which  are  expressed  in 
the  laws  of  GayLussac; 

First. — There  exists  a  simple  relation  between  the  volumes  of  gases 
whirh  f'ombine  with  each  other. 

SeroHfL — There  exists  a  simple  relation  between  the  sum  of  the 
vohtmes  of  the  constituent  gaseSy  and  the  volume  of  the  gas  formed  hy 
their  union.    For  example: 

1  volum©  chlorin  unites  with  1  volume  hydrogen  to  form  2  volumes  hydrochloric 

acid. 
1  volume  oxy^-en  aiiites  with  2  volumes  hydrogen  to  form  2  volumes  vapor  of 

water. 
1  volume  nitrogen  unites  with  3  volumes  hydrogen  to  form  2  volumes  ammoniii. 
1  volume  oxygen  aniteo  with  1  volume  nitrogen  to  form  2  volumes  nitric  o%id. 
1  volume  oxygen  unites  with  2  volumes  nitrogen  to  form  2  volumes  nitrous  oxid. 

It  will  be  noted  that  hydrog^en  combines  with  eblorin,  oxygen  and 
nitrogen  in  the  respective  proportions  by  vohime  of  1:1,  2:1  and  3:1. 
Also,  that»  while  the  volume  of  the  compound  of  hydrogen  and 
chlorin  is  equal  to  the  sum  of  the  volumes  of  the  componeutSt  iu  the 
formation  of  the  compound  with  oxygen  there  is  a  condensation  in 
volume  of  one-third,  and  of  that  with  nitrogen  of  one-half. 

Molecular  and  Atomic  Theories. — Postulate  of  Avogadro,  or  of 
Ampere, — In  explanation  of  the  facts  just  cited  (as  well  as  of  many 
others),  it  is  assumed  that  matter  is  not  infinitely  divisible,  that  there 
is  a  certain  smallest  qmmtiltf  of  anf/  snbstance  whirh  can  exist  in  the 
free  state,  which  is  called  the  molecule.  With  regard  to  compoond 
substances  (p.  48),  this  is  more  than  a  mere  assumption,  for,  con- 
sidering the  smallest  quantity  of  a  compound,  however  small  it  may 
be,  it  still  retains  the  properties  of  the  compound,  but  it  contains  at 
least  two  smaller  magnitudes,  of  substances  whose  properties  differ 
from  those  of  the  compound,  i.  e.,  those  of  the  elements  of  which  it 
is  composed,  and,  therefore,  it  cannot  itself  be  infinitely  small.  The 
molecule  of  hj-'drochloric  acid  contains  both  hydrogen  and  chlorin, 
and,  however  small  it  may  be,  the  whole  must  be  greater  than  either 
of  its  parts,  and  it  must  therefore  ha%^e  a  definite  magnitude. 

Almost  simultaneously,  in  1811  and  1812,  Avogadro  and  Ampere 
based  upon  the  facts  described  in  the  laws  of  GayLussac  the  postu- 
late that  egual  rohtmes  of  all  gases,  mtder  Ulce  conditions  of  tempera- 
ture and  pressure,  eontaiit  ei^ual  numbers  of  molecules. 

This  is  usually  referred  to  as  the  "law"  of  Avogadro,  or  of 
Ampere.  It  has,  however,  not  the  force  of  a  scientific  ^4aw/'  which, 
like  the  laws  above  quoted,  is  simply  a  generalized  statement  of  a 
series  of  observed  and  proven  facts.  This  statement,  being  based 
upon  the  nndemonstrable  assumption  of  the  existence  of  molecules,  is 


CHEMICjiL    PHENOMENA 


53 


DO  more  capable  of  proof  than  is  the  postulate  of  Eac!id»  that  "a 
straight  Hoe  may  be  drawn  between  any  two  points."  But  this  postu- 
late of  Avogadro  has  proven  itself  to  be  of  enormous  utility  in  the 
development  of  both  chemistry  and  physics;  and  its  close  and  uniform 
accordance  with  the  results  of  both  physical  and  chemical  investiga- 
tions, and  with  the  modern  kinetic  theory  of  gases  lends  it  addi- 
tional support. 

Applying  the  postulate  of  Avogadro  to  the  laws  of  GayLussac,  we 
may  translate  the  first  three  combinations  given  in  the  table  on  page 
52,  into  the  following  r 

1  molecttle  ehlorin  tmitea  with  1  mole<3iile  hydrogeD,  to  farm  2  mole- 
cules hydrochloric  acid.  * 

1  molecule  oxygen  niniteB  with  2  moleoules  hydro gen^  to  form  2  mole* 
ctiles  vapor  of  water. 

1  molec'uJe  nitrogen  unites  with  3  moleeules  hydrogen,  to  form  2 
moleeules  ammonia. 

But  the  ponderable  quantities  in  which  these  combinations  take 
I»lace  are: 

35.5  ehlorin  to « 1  hydrogen. 

16     oxygen  to , .2  hydrogen. 

14     nitrogen  to 3  hydrogen. 

as  aingle  molecules  of  hydrogen,  oxygen  and  nitrogen  are  in 
these  combinations  subdivided  to  form  2  molecules  of  hydrochloric 
i,  water  and  ammonia,  it  follows  that  these  molecules  must  each 
main  two  equal  quantities  of  hydrogen,  oxygen  and  nitrogen,  less 
in  size  than  the  molecules  themselves.  And,  further,  as  in  these 
bgtances  each  molecule  contains  two  of  the  smaller  quantities,  or 
atoms,  the  relation  between  the  weights  of  the  molecnles  must  also 
be  the  relation  between  the  weights  of  the  atoms,  and  we  may  there- 
fore express  the  combinations  thus: 

1  atom  ehlorin  weighing  35.5  unitea  with  1  atom  hydrogen  weighing  1  j 
I  atom  oiygen  weighing  16  unites  with  2  atoms  hydrogen  weighing  2; 
1  atom  nitrogen  weighing  14  unites  with  3  atoms  hydrogen  weighing  3j 

and  eousequently,  if  the  atom  of  hydrogen  weighs  1,  that  of  ehlorin 
teighs  35.5,  that  of  oxygen  16,  and  that  of  nitrogen  14, 

AssQRiing,  then,  the  existence  of  molecules  and  atoms,  the  distinc^ 
between  them  may  be  expressed  in  the  following  definitions: 

A  molecHle  (M)  is  the  smallest  quantitij  of  any  substance  that  c€m 
ttiif  in  (he  free  state. 

The  molecules  of  all  substanees  are  made  up  of  atoms,  upon  whose 
nature,  number  and  arrangement  with  regard  to  each  other  the  prop- 
trtiej  of  the  substance  depend.   In  elementary  substances  the  atoms 


S4 


MANUAL    OF    CHEMISTRY 


are  all  of  Ibe  same  kiud.    The  molecules  of  cominjuiid  substances 
contain  at  least  two  atoms  diffen^nt  in  kind. 

An  atom  i.v  the  smnihsi  quatifitif  uf  an  elementary  substance  which 
can  enter  info  the  comjmnttion  of  tt  molecule. 

The  word  "atom"'  ean  only  bts  used  in  speaking  of  an  elementary 
fiubstance,  and  then  only  as  a  constituent  of  a  moleenle  or  while 
passing  throngh  a  chemical  reaction.  When  liberated »  atoms  usually 
unite  to  form  other  molecules,  although  there  are  a  few  elements 
whose  molecules  consist  of  single  atoms. 

lu  the  light  of  the  molecular  and  atomic  theories  the  distiuctioo 
between  mechanical  mixtures,  physicid  mixtures  and  compounds  may 
be  made  a»ore  briefly  than  by  the  statements  on  pp.  47,  4H,  by  saying 
that  tlie  first  are  mixtures  of  masses*  the  second  mixtures  of  mole- 
cules, and  tlie  third  compounds  of  atoms. 

Atomic  Weight. — The  atoms  of  the  several  elements  have  definite 
relative  weightSi  and  upon  the  accurate  determination  of  these  all 
methods  of  quantitative  cheniical  analysis  depend.  (See  Stoicldome- 
try»  p.  78.)  Clearly,  as  the  atomic  weights  are  relative^  the  weight 
of  one  atom  of  any  element  may  be  selected  as  the  unit  or  base  in 
terms  of  which  the  weights  of  the  atoms  of  other  elements  may  be 
expressed.  Formerly  the  unit  adopted  was  the  weight  of  one  atom  of 
the  lightest  kuowu  substance,  hydrogen,  and  the  atomic  weight  of  au 
clement  represented  the  weight  of  one  atom  of  that  element  as  com- 
pared with  the  weight  of  one  atom  of  hydrogen. 

But  the  determination  of  the  atomic  weight  of  an  element  depends 
upon  accurate  analj'ses  of  compounds  of  that  element,  and  hydrogen, 
unfortunately,  forms  compounds  amenable  to  accurate  analysis  with 
but  few  other  elements.  Oxygen,  on  the  other  hand,  forms  compounds 
with  a  great  number  of  other  elements,  and  determinations  of  atomic 
weights  have  usually  been  made  with  reference  to  oxygen  in  the  first 
instance.  If  expressed  in  terms  of  H^l,  therefore,  their  accuracy 
depends  upon  tlie  correctness  of  the  determination  of  the  ratio  be- 
tween the  atomic  weights  of  oxygen  and  of  hydrogen,  which,  accord- 
ing to  the  most  recent  determination,  is  H:0::ir  15.88  or  0:H::16: 
l.CM}8.  But  this  ratio  cannot  be  considered  as  being  definitely  de- 
cided; therefore,  to  avoid  the  necessity  of  a  rcralculatiou  of  all  atomic 
weights  witii  increased  accuracy  of  the  determination  of  the  ratio  O:  H, 
chemists  have  agreed  that  the  atomic  weight  of  oxygen  be  taken  as 
the  Viase  of  tlie  system  at  lf>.  In  this  system  the  atonnc  weight  of 
hydrogen  becomes  1.008,  oc  for  ordinary  purposes  1.01.  An  inci- 
dental advantage  of  this  system  is  that  the  atomic  w^eights  are  more 
frequently  integral  numbers  than  with  the  system  in  which  H^=  1,  as 
wnll  be  seen  in  the  following  table,  in  which  both  systems  are 
given : 


ELEMENTS 


55 


ELEMENTS 


Namx 

Symbol 

0-16 

H=l 

Namx 

Symbol 

0-16 

H-1 

Aetinium  .   .    . 

Ac 

1  Molybdenum    . 

Mo 

96. 

95.3 

Alaminium 

Al 

27.*1  ' 

26.9  * 

1  Neodymium  .   . 

Nd 

143.6 

142.5 

ADtiinonj 

Sb 

120.2 

119.3 

1  Neon 

Ne 

20. 

19.9 

Argon     .   . 

A 

39.9 

39.6 

Nickel    .   .    .   . 

Ni 

58.7 

58.3 

Arsenic  .   . 

As 

75. 

74.4 

Nitrogen   .   .   . 

N 

14.04 

13.93 

B»rium  .   . 

Ba 

137.4 

136.4 

Osmium     .   .   . 

Os 

191. 

189.6 

fiismuth    . 

Bi 

208.5 

206.9 

Oxygen  .... 

0 

16.000 

15.88 

Boron     .   . 

B 

11. 

10.9 

Palladium     .   . 

Pd 

106.5 

105.7 

Bromin  .   . 

Br 

79.96 

79.36 

Phosphorus  .   . 

P 

31. 

30.77 

Cadmium  .   . 

Cd 

112.4 

111.6 

Platinum  .   .   . 

Pt 

194.8 

193.3 

Cesium      .   . 

Cs 

132.9 

131.9 

Potassium     .   . 

K 

39.15 

38.85 

Calcium     .   . 

Ca 

40.1 

39.7 

Praseodymium. 

Pr 

140.5 

139.4 

Carbon  .   . 

C 

12. 

11.91 

Radium      .   .   . 

Ra 

225. 

223.3 

Cerium  .    . 

Ce 

140.25 

139.2 

Rhodium  .   .    . 

Rh 

103. 

102.2 

Chlorin  .    . 

CI 

35.45 

35.18 

Rubidium  .   .   . 

Rb 

85.5 

84.9 

Chromium 

Cr 

52.1 

51.7 

Ruthenium   .   . 

Ru 

101.7 

100.9 

Cobalt    .   . 

Co 

59. 

58.55 

Samarium     .   . 

Sm 

150.3 

149.2 

Columbium 

Cb 

94. 

93.3 

Scandium  .   .   . 

Sc 

44.1 

43.8 

Cepper  .   . 

Cu 

6:^.6 

63.1 

Selenium  .   .   . 

Se 

79.2 

78.6 

Erbium  .   . 

Er 

106. 

164.8 

Silicon  .... 

Si 

28.4 

28  2 

Europium 

Eu 

1.51.79 

150.58 

Silver     .... 

Ag 

107.93 

107.11 

Plaorin  .   . 

K 

19. 

18.9 

Sodium  .... 

Na 

23.05 

22.88 

Gadolinium 

Gd 

156. 

154.8 

Stroutium     .   . 

8r 

87.6 

86  94 

Gallium     .   . 

Gft 

70. 

69.5 

Sulfur    .... 

8 

32.06 

31.82 

Germanium 

Go 

72  5 

72. 

Tantalinm    .   . 

Ta 

183. 

181.6 

Glucinium 

Gl 

9.1 

9.03 

Tellurium .   .   . 

Te 

127.6 

126.6 

Gold   .   .    . 

Au 

197.2 

195.7 

Torbium    .   .    . 

Tb 

160. 

158.8 

Helium  . 

Ho 

4. 

4. 

Thallium  .   .   . 

Tl 

204.1 

202.6 

Hjdrofcen 

H 

1.008 

1.000 

Thorium    .   .    . 

Th 

232.5 

230.8 

Indium  .  . 

In 

115. 

114  1 

Thulium    .   .    . 

Tm 

171. 

169.7 

lodin  .... 

r 

I2a.97 

126.01 

Tin 

Sn 

119. 

118.1 

Iridium  .   . 

Ir 

193. 

191. r> 

Titanium  .   .    . 

Ti 

48.1 

47.7 

Iron    .   .   . 

Fe 

55  9 

55.5 

Tunsrsten  .    .   . 

W 

184. 

182.6 

Krypton 

Kr 

81. K 

81.2 

Uranium    .    .    . 

U 

238  5 

236.7 

Lanthanum 

La 

138.9 

137.9 

Vanadium     .   . 

V 

51.2 

50.8 

Lead  .   .   . 

Pb 

206.9 

205.35 

Xenon    .... 

Xe 

128. 

127. 

Lithium     . 

Li 

7.03 

6.98 

Ytterbium     .   . 

Yb 

173. 

171.7 

Magnesium 

Mg 

24.36 

24.18 

Yttrium     .   .   . 

Yt 

89. 

88.3 

Manganese 

Mn 

55. 

54.6 

Zinc 

Zn 

65.4 

64.9 

Mercury    . 

Hg 

200. 

198.5 

Zirconium     .   . 

Zr 

90.6 

89.9 

In  some  eases  the  results  of  analyses  are  such  as  would  agree  with 
two  values  as  the  atomic  weight  equally  well.  In  this  ease  we  can 
decide  which  is  the  correct  value  by  the  law  of  Dulong  and  Petit: 
The  product  of  the  specific  heat  (p.  33)  of  any  solid  element  into  its 
atomic  weight  is  approximately  a  constant  number.  This  number, 
known  as  the  atomic  heat,  varies  between  5.39  and  6.87.  When  the 
chemical  relations  indicate  either  one  of  two  numbers  as  the  atomic 
weight,  that  one  is  selected  which,  when  multiplied  by  the  specific 
heat,  gives  an  atomic  heat  within  the  above  limits. 

The  atomic  heats  of  those  elements  which  exist  in  two  or  more 
allotropic  modifications  (p.  17)   vary  in  the  several  forms,  and  at 


56 


MANUAL    OF    CHEMISTRY 


different  temperattires,  and  fall  outside  of  the  above  liiDits.  Thus  the 
atomic  heat  of  crystallized  boron  is  2.11  at — 39.6^»  aud  3.99  at 
233*2^,  while  that  of  amorphous  boron  is  2.81;  that  of  the  diamond 
is  0.76  at  —50.5°,  and  5.51  at  985"^,  while  that  of  graphite  is  1.^7  at 
—50.3°,  and  5.60  at  978°. 

Molecular  Weight. — We  have  seen  (p.  53)  that  in  the  formation 
of  hydroehloric  aeid,  water  and  ammonia,  the  molecules  of  hydrogen 
each  contribute  one*half  of  their  material  to  the  formation  of  each  of 
the  several  new  molecules.  The  molecules  of  hydrogen  must,  there- 
fore, contain  at  least  two  atoms  each;  and  it  can  also  be  shown  that 
the  molecules  of  chlorin»  oxygen,  nitrogen  and,  in  fact,  of  most 
other  elements  also  contain  at  least  two  atoms  each.  There  are  excep- 
tions, however,  in  the  eases  of  several  metals,  whose  molecules  con- 
sist of  single  atoms. 

Taking  the  weight  of  one  atom  of  hydrogen  as  the  basis  of  mo- 
lecular as  well  as  of  atomic  weights  the  molecular  weight  (MW)  of  a 
SHbHtanee  in  the  weight  of  its  moleeule  as  compared  with  the  weight  of 
an  atom  of  hijdrogen.  It  is  immaterial  to  this  definition  what  the 
absohite  weight  of  the  hydrogen  atom  may  be,  or  whether  it  is  con- 
sidered as  weighing  1.000  or  1.008.  The  molecular  weight  is  also, 
obviously » the  sura  of  the  weights  of  the  atoms  making  up  the  molecule, 

A  ready  method  for  determining  the  molecular  weights  of  sub- 
stances existing  or  obtainable  in  the  aeriform  state  is  based  upon  the 
postulate  of  Avogadro.  The  specific  gravity  of  a  gas  or  vapor 
referred  to  hydrogen  is  the  weight  of  any  given  volume  as  compared 
with  the  weight  of  an  eqiial  volume  of  hydrogen  (p.  10),  But  equal 
volumes  contain  equal  numbers  of  molecules  {p.  52),  aud  the  relation 
of  weights,  the  sp.  gr.,  of  the  whole  is  the  same  for  any  equal  frac- 
tions, down  to  the  molecules,  and  therefore  this  specific  gravity  is  the 
weight  of  a  molecule  of  the  gas  as  compared  with  that  of  a  molecule 
of  hydrogen;  and  as  the  molecule  of  hydrogen  contains  two  atoms, 
while  one  atom  is  the  unit  of  comparison,  it  follows  that  fht  specific 
gravity  of  a  ga^i  compared  with  hijdrogen,  mnliipUed  hy  two^  is  its 
moleeular  weight. 

The  same  principle  is  more  directly  applied  by  the  use  of  the 
density  of  gas  (p.  10)  in  place  of  its  sp.  gr.  (H=^l).  The  density  of 
a  gas  or  vapor  (02^^32)  is  its  molecular  weight  (H  ^  1.008).  By  this 
method,  also,  the  molecular  weight  is  directly  referred  to  the  system 
of  atomic  weights  in  which  0=^32,  H  =  1.008,  etc.  {p.  55),  and  the 
moleeular  weights  of  hydrogen,  oxj^gen,  hydrochloric  acid,  and  water 
are  found  to  be  2.016,  32,  36.458  and  18.016,  respectively. 

If  the  absolute  density  (p.  9)  of  a  gas  be  known,  its  molecular 
weight,  or  density,  is  obtained  by  dividing  this  by  the  absolute  den- 
sity of  the  normal  gas  {p.  10) .    As  the  normal  gas  is  assumed  to  be  32 


MOLECULES 


67 


times  lighter  than  oxygen,  and  1  L,  of  oxygen  at  0°  and  76  cent, 
weighs  1,4291  gms.  the  absolute  density  of  the  normal  gas  for  Ice.  is 

"3^^  or  .00004466  gra.    Therefore  the  weight  of  a  liter  of  gas  at 

0**  and  76  cent.,  divided  by  .04466,  is  its  molecular  weight.    Thns  for 

chlorin^^^  =  70.9.    Or  the  determination  may  be  made  with  any 

Yoltime  of  gas,  V  in  ce.,  at  any  temperature,  t  in  C°,  and  any  pres- 
sure, p  in  cent.  Eg,  by  aseertaining  its  weight,  P  in  gms.,  by  the 
(273  +  t)P     ^j^^^  ^^^^^   oxygen  at  15° 

288  X  .6773 


formnla:  M  =  6232 


p  V 


cent,  weigh  0.6773  gm.;   therefore  M  =  6232 


and  76 
=  31.99. 


76X500 

When  a  substance  cannot  be  volatilized  uuehanged,  its  molecular 
weight  may  be  determined  from  certain  properties  of  its  solutions, 
which  will  be  considered  under  the  head  of  ^* Osmotic  Pressure*'  (p,  66). 
Gram-molecule  —  Moh  —  That  quantity  of  a  substance  whose 
weight  is  represented  by  its  molecular  weight  expressed  in  grams  is 
called  a  gram-molecule,  or  mol ;  as  32  gms.  oxygen,  70.9  gms, 
cblorin,  18.016  gms*  water. 

The  mol  is  a  quantity  both  theoretically  and  practically  important. 
We  have  now  to  consider  it  in  connection  with  certain  facts  already 
referred  to. 

Molecular  VoIume.'^The  molecular  volume  of  a  gas  or  liquid 
is  the  volume  occupied  by  one  mol  of  the  substance  under  normal 
t'onditions. 

According  to  the  postulate  of  Avogadro  (p.  62),  equal  molecular 
freights  (mols)  of  all  gases  must  occupy  the  same  volume,  at  the 
«atne  temperature  and  pressure,  or,  in  other  w^ords:  the  moleeular 
Mume  (Vm)  of  gases  is  a  constant  quantitij.  The  molecular  volume 
<>f  a  gas  is  the  product  of  its  specific  volume  (Vs),  i.  e.,  the  vol- 
ume in  cc.  which  1  gm.  occupies  at  0"^  and  76  cm.  (p.  10),  and  its 
molecular  weight*   Thus 


W«icbt  of  1  L  in  jcmi. 
at  0°  unci  70  em. 

Hydropen  .   *   .  .  •  0.08988   .  . 

Oxygen 1,4291     ,  . 

Nitrogen    .....  1,2507     .  . 


Vb. 
,  11,111       . 
.        &D9.7  . 
.       799.5  . 


Mvr, 

.    2,016  , 

32.000  < 

.  28.080  . 


VbXMw.  in  L. 
.    .  22.399 
,    .  22.390 
.    .  22.450 


The  vohime  occupied  by  1  mol  of  a  gas  at  O'^  and  76  cm.  is  22.4 
liters.  Consequently  the  weiglit,  p,  of  any  given  volume  of  gas,  v,  in 

liters,  reduced  to  normal  conditions  is:  p^  ~'^a~^  ^^^  ^^^  volume, 

.^  22  4  p 

in  liters,  of  any  given  weight  of  gas  isr  v=-^^  . 

When  considering  molecular  quantities  of  gases  the  equation  of 


68  MANUAL    OF    CHEMISTRY 

the  general  gas  law:  vp=  '^^^T  (p.  24)  may  be  written:    vp  =  RT, 

in  which  R  is  a  constant,  depending  upon  the  units  chosen,  but  not 
upon  the  nature  of  the  gas.  As  1  inol  of  a  gas  occupies  22.4  liters  at 
0°  and  1  atni.  pressure,  if  it  be  compressed  to  the  volume  of  one 
liter  at  0°,  the  value  of  po  would  become  22.4  atm.,  and  that  of  v©  =1. 

The  value  of  R  =  ^  would  then  be  ^^^^=.0821,  and  vp=.0821T; 

(vp^ liter: atm.),  a  formula  which   is   used   in    many  calculations, 

.0821T  ,  .0821T 

e.  g.,  v  =  -y-,  andp=     ,^— . 

Unsaturated  vapors  behave  like  gases  (p.  30),  and  one  mol  of  the 
unsaturated  vapor  of  any  substance  therefore  occupies  22.4  liters  at 
0°  and  1  atm.,  or  exerts  a  pressure  of  22.4  atm.  at  0°  if  compressed 
to  the  volume  of  1  liter.  The  hypothesis  that  the  unsaturated  vapor 
of  a  substance  which  cannot  be  vaporized  without  decomposition 
would  obey  the  same  laws  if  it  could  exist  is  borne  out  by  facts. 

08*^  IT 

From  the  formula:   p='—^ —  the  pressure,  p,  may  be  calculated  for 

a  mol  of  any  substance,  presuming  its  volume  to  be  compressed  or 
expanded.  Thus,  if  we  imagine  1  gm.  of  the  hypothetical  vapor  of 
cane-sugar  to  occupy  a  volume  of  100  cc.  at  15.5°,  a  condition  which 
would  correspond  to  that  existing  in  a  1  per  cent  solution  of  sugar,  the 
volume  which  would  be  occupied  by  1  mol  (Ci2H220ii  =  342)  would 

0821T 

be  342X100,  or,  34.2  liters.    Then  the  equation  p  =  '—^ —  would   be- 

0821X288  5 
come  p^=' — 342 — ^  =  0.692   atm.      This   value   corresponds    quite 

closely  to  the  observed  osmotic  pressure,  0.684  atm.,  of  a  1  per  cent 
solution  of  sugar  at  the  same  temperature  (see  p.  70). 

The  molecular  volumes  of  liquids  and  of  their  saturated  vapors 
vary  with  the  composition  of  the  substance,  and  bear  fixed  relations 
to  their  critical  temperature,  pressure  and  density  (p.  29). 

The  Molecular  Heat  of  a  substance  is  the  product  of  its  specific 
heat  (p.  33)  and  its  molecular  weight.  For  solids  the  molecular  heat 
is  equal  to  the  sum  of  the  atomic  heats  (p.  55)  of  the  elements  con- 
tained in  the  molecule.  Thus  the  atomic  heat  of  hydrogen  is  2.3,  and 
that  of  oxygen  is  4.0,  from  which  the  calculated  molecular  heat  of  ice 
is  2.3  X  2  +  4  =  8.6,  while  the  observed  specific  heat  of  ice  is  0.474, 
and  0.474X18.016  =  8.54. 

The  molecular  heats  of  gases  at  constant  pressure  (p.  33)  dimin- 
ish with  diminishing  temperature,  and  appear  to  converge  towards 
6.3  at  the  absolute  zero. 

The  Molecular  Heat  of  Vaporization  of  a  liquid  is  the  amount  of 
heat,  expressed  in  calories,  required  to  convert  1  mol  of  the  substance 
into  vapor  at  the  same  temperature  as  the  liquid  (p.  33),  and  is  the 


VALENCE  59 

product  of  the  heat  of  vaporizatiou  and  the  molecular  weight.  Thus 
for  water  at  100°  it  is  535.9X18.016  =  9,654.8  cal.  The  quotient 
obtained  by  dividing  the  molecular  heat  of  vaporization  by  the  abso- 
lute boiling  point  is  approximately  constant  at  22.  Thus  for  water: 
9654.8  H- 373  =  25.8.  This  value  is  departed  from  widely  by  sub- 
titauces  whose  molecular  structure  differs  in  the  liquid  and  gaseous 
states. 

Valence  or  atomicity. — It  is  known  that  the  atoms  of  different 
elements  possess  different  powers  of  combining  with  and  of  replac- 
ing atoms  of  hydrogen.     Thus: 

1  atom  of  chlorin  combines  with  1  atom  of  hydrogen. 
1  atom  of  oxygen  combines  with  2  atoms  of  hydrogen. 
1  atom  of  nitrogen  combines  with  3  atoms  of  hydrogen. 
1  atom  of  carbon   combines  with  4  atoms  of  hydrogen. 

The  valence,  atomicity,  or  equivalence  of  an  element  is  the 
saturating  power  of  one  of  its  atoms  as  compared  with  that  of 
one  atom  of  hydrogen. 

Elements  may  be  classified  according  to  their  valence  into  — 

Univalent  elements,  or  monads CI' 

Bivalent  elements,  or  dyads O" 

Trivalent  elements,  or  triads B'" 

Quadrivalent  elements,  or  tetrads €!▼ 

Quinquivalent  elements,  or  pentads P^ 

Sexvalent  elements,  or  hexads Wvi 

Elements  of  even  valence,  i.  e.,  those  which  are  bivalent,  quad- 
rivalent, or  sexvalent,  are  sometimes  called  artiads ;  those  of  uneven 
valence  being  designated  as  perissads. 

In  notation  the  valence  is  indicated,  as  above,  by  signs  placed 
to  the  right  and  above  the  symbol  of  the  element. 

But  the  valence  of  the  elements  is  not  fixed  and  invariable. 
Thus,  while  chlorin  and  iodiu  each  combine  with  hydrogen,  atom 
for  atom,  and  in  those  compounds  are  consequently  univalent, 
they  unite  with  each  other  to  form  two  compounds  —  one  containing 
one  atom  of  iodin  and  one  of  chlorin,  the  other  containing  one 
atom  of  iodin  and  three  of  chlorin.  Chlorin  being  univalent,  iodin 
is  obviously  trivalent  in  the  second  of  these  compounds.  Again, 
phosphorus  forms  two  chlorids,  one  containing  three,  the  other  five 
atoms  of  chlorin  to  one  of  phosphorus. 

In  view  of  these  facts,  we  must  consider  either:  1,  That  the 
valence  of  an  element  is  that  which  it  exhibits  in  its  most  saturated 
compounds,  as  phosphorus  in  the  pentachlorid,  and  that  the  lower 
compounds  are  non  -  saturated,  and  have  free  valences;  or  2,  that 
the  valence   is  variable.     The   first  supposition  depends  too  much 


60 


MANUAL    OF    CHEMISTRY 


upon  the  cbances  of  discovery  of  compounds  in  which  the  element 
has  a  higher  valence  than  that  which  might  be  considered  the  max- 
imum to*day.  The  second  supposition  —  notwithstanding  the  fact 
that,  if  we  admit  the  possibility  of  two  distinct  valences,  we  must 
also  admit  the  possibility  of  others  —  is  certainly  the  more  tenable 
and  the  more  natural.  In  speaking,  thirefore^  of  (he  vaJencf  of  an 
element,  tee  must  not  consider  it  as  an  absolute  quaiify  of  its  atoms^ 
but  simply  as  their  combining  power  in  the  partirnlar  class  of  com- 
pounds under  consideration*  Indeed,  compounds  are  known  in  whose 
molecules  the  atoms  of  one  element  exhibit  two  distinct  valences* 
Thus,  ammoniiira  cyanafce  contains  tw^o  atoms  of  nitrogen:  one  in 
the  amoionium  group  is  quinquivalent,  oue  in  the  acid  radical  is 
trivaleut. 

"  When  an  element  exhibits  diflferent  valences,  these  differ  from 
each  other  by  two.  Thus,  phosphorus  is  trivalent  or  quinquivalent; 
platinum  is  bivalent  or  quadriviileut. 

The  chemical  equivalent,  or  equivalent  weight,  of  an  element 
is  the  weight  of  that  element  capable  of  combiuing  with  unit  weight 
of  hydrogen  (or  <?hlorin).  It  is,  therefore,  its  atomic  w^eight  divided 
by  its  valence.  We  have  seen  (p,  53)  that  35.5  parts  by  weight  of 
chlorin  combine  with  1  part  by  weight  of  hydrogen,  16  of  oxygen 
with  2  of  hydrogen,  and  14  of  Bitrogen  with  3  of  hydrogen. 
Chlorin  being  univalent,  oxygen  bivalent  and  nitrogen  trivalent, 
their  equivalent  weights  are,  therefore,  respecti\^ely :  35.5  -5-  1  =  35,5, 
16-i-2  =  8,  and  14 H- 3 --4. 67.    (See  also  p.  64j 

A  gram-equivalent  (gm,:eq,)  of  an  element  is  a  quantity  of  that 
element  whose  weight  in  grams  is  equal  to  its  molecular  weight 
divided  by  its  valence*  Thus  23.05  gms.  of  sodium,  and  65.4^-2^^ 
32,7  gms.  of  zinc^  are  gram  equivalents  of  those  metals. 

Symbols,  Formulae,  Equations. —  Symbols  are  conventional 
abbreviations  of  the  names  of  the  elements,  whose  purpose  it  is  to 
introduce  simplicity  and  exactness  into  descriptions  of  chemical  ac- 
tions. They  consist  of  the  initial  letter  of  the  Latin  name  of  the  ele- 
ment, to  which  is  usually  added  one  of  the  other  letters.  If  there  be 
more  than  two  elements  whose  names  begin  with  the  same  letter,  the 
single -letter  symbol  is  reserved  for  the  coinraonest  element.  Thus, 
we  have  ten  elements  whose  names  begin  with  C;  of  these  the  com- 
monest is  Carbon,  whose  symbol  is  C;  the  others  have  double-letter 
symbols,  as  Chlorin,  CI;   Cobalt,  Co;  Copper,  Cu  (Cuprum),  etc. 

These  symbols  do  not  indicate  simply  an  indeterminate  quantity^ 
but  represent  one  afoni  of  the  corresponding  element. 

When  more  than  one  atom  is  spoken  of,  the  number  of  atoms 
which  it  is  desired  to  indicate  is  written  either  before  the  symbol 
or,,  in   small   figures,   after  and   below  it.     Thus,  H  indicates  one 


I 
I 


I 
I 


EQUATIONS 


61 


itom  of  hydrogen;    2C1,  two  atoms  of  chloriu;    C4,  four  atoms  of 
csarbon,  etc. 

What  the  symbol  is  to  the  elemeDt,  the  formula  is  to  the  com- 
pound. By  it  the  number  and  kind  of  atoms  of  which  the  molecule 
of  a  gubstance  is  made  up  are  indicated.  The  Biraplcst  kind  of 
forniulie  are  what  are  known  as  empirical  formulae,  which  indicate 
oaly  the  kind  and  number  of  atoms  which  form  the  compound.  Thus, 
HCl  indicates  a  molecule  composed  of  one  atom  of  hydrogen  united 
with  one  atom  of  chlortn;  5II2O,  five  molecules,  each  composed  of 
two  atoms  of  hydrogen  and  one  atom  of  oxygen »  the  number  of 
molecules  being  indicated  by  the  proper  numeral  placed  before  the 
formula,  in  which  place  it  applies  to  all  the  symbols  following  it. 
»iDetime8  it  is  desired  that  a  numeral  shall  ai>ply  to  a  part  of  the 

bols  only,  in  which  case  they  are  enclosed  in  parentheses j   thus, 
AI2  (S04)a  means  twice  Al  and  three  times  SO4. 

For  other  varieties  of  formuh^,  see  pp.  85,  86. 

Equations  are  combinations  of  fonnulte  and  algebraic  signs  so 
arranged  as  to  indicate  a  clipmi^'al  reaction  and  its  results.  The  signs 
used  are  the  plus  and  equality  signs;  the  former  being  equivalent  to 
"and,"  and  the  second  meaning  *^ have  reacted  upon  each  other  and 
have  produced."  The  substances  entering  into  the  reaction  are  placed 
before  the  equality  sign,  and  the  products  of  the  reaction  after  it; 
tbus,  the  equation 

2KHO+Ha80|=K2SO*  I  2H,0 

means,  when  translated  into  ordinary  language:  two  molecules  of 
otash,  each  composed  of  one  atom  of  potassium,  one  atom  of  hydro- 
en,  and  one  atom  of  oxygen,  and  one  molecule  of  sulfuric  acid, 
iposed  of  two  atoms  of  hydrogen,  one  atom  of  sulfur,  and  four 
'^  atoms  of  oxygen,  have  rmeted  vpon  fach  of  her  and  have  produced  one 
molecule  of  potassium  sulfate,  composed  of  two  atoms  of  potassium, 
me  atom  of  sulfur,  and  four  atoms  of  oxygen,  and  two  molecules 
^of  water,  each  composed  of  two  atoms  of  hydrogen  and  one  atom 
of  oxygen. 

As  no  material  is  ever  lost  or  crfutfd  in  a  refjefion,  the  nmnher  of 
fmeh  kind  of  atom  orrnrriny  before  the  equality  sign  in  an  equation 
musi  always  be  the  same  as  that  oecurring  after  it.  In  writing  equa- 
tions, they  should  always  be  proved  by  examining  whether  the  half  of 
the  equation  before  the  equality  sign  contains  the  same  number  of 
each  kind  of  atom  as  that  after  the  equality  sign.  If  it  does  not,  the 
; equation  is  incorrect. 

The  word  "reaction**  is  used  in  chemistry  with  two  distinct  mean- 
ings:   As  applying  to  the  actiou  mentioned  above,  it  refers  to  the 
lOmtual   action  of   two   subetauces  upon   each  other.     In  the  other 


62  MANUAL    OF    CHEMISTRY 

meaning  it  refers  to  the  action  of  substances  upon  certain  organic 
pigments.  Thus,  the  reaction  of  a  substance  is  acid,  when  it  turns 
blue  litmus  red;  alkaline,  when  it  turns  reddened  litmus  blue,  and 
neutral,  when  it  has  no  action  upon  either  blue  or  red  litmus. 

Chemical  reactions  in  the  former  sense  are  either:  1.  Combina- 
tions, also  called  syntheses,  in  which  elements  or  simpler  compounds 
unite  to  form  more  complex  molecules,  as  when  2H2+02=2H20;  2. 
Decompositions,  also  called  analyses,  processes  the  reverse  of  combi- 
nations, as  when  2H2O  =  2H2+02;  and  3.  Double  decompositions,  or 
matatheses,  when  two  substances  mutually  react  upon  each  other 
with  formation  of  new  substances,  as  when  2KHOH-H2S04=K2S04+ 
2H2O.  Special  varieties  of  these  several  kinds  of  reaction,  which  are 
sufficiently  distinctive,  have  received  distinguishing  names,  such  as 
condensations,  etc.,  and  will  be  considered  later.  There  also  occur, 
notably  with  the  compounds  of  carbon,  instances  of  atomic  rear- 
rangement, or  transposition,  in  which  the  composition  remains  the 
«ame,  but  the  constitution  (p.  84)  is  changed:  as  when  ammonium 
isocyanate,  0:C:N.NH4  is  converted  into  urea,  H2N.CO.NH2. 

Electrolysis. — We  have  seen  (p.  44)  that  when  hydrochloric  acid 
is  electrolyzed,  hydrogen  is  given  oif  at  tlie  negative  pole,  and  is 
therefore  electropositive,  while  chlorin  is  given  off  at  the  positive 
pole,  and  is  therefore  electronegative.  But  if  a  compound  of  chlorin 
and  sulfur  be  electrolyzed,  chlorin  is  given  off  at  the  negative  elec- 
trode, and  is  therefore  electropositive.  Chlorin  is  consequently  elec- 
tropositive to  sulfur,  and  electronegative  to  hydrogen. 

The  results  of  electrolysis  of  binary  compounds  of  many  elements 
have  shown  that  oxygen  is  electronegative,  and  the  alkali  metals  (p. 
215)  are  electropositive  to  all  other  elements  with  which  they  form 
binary  compounds.  If  the  elements  be  arranged  in  an  electro- 
chemical series,  with  oxygen  at  the  electronegative  end,  and  cesium 
at  the  electropositive  end,  and  if  the  other  elements  be  placed  in  the 
series  in  such  positions  that  each  will  be  between  oxygen  and  all 
other  elements  toward  which  it  is  electronegative,  it  will  be  found 
that  hydrogen  will  occupy  a  position  about  midway  between  the  two 
ends,  but  nearer  to  the  electronegative,  and  that  the  elements  of 
the  acidulous  class  (p.  101)  will  be  placed  between  hydrogen  and 
oxygen,  while  the  metals  will  be  placed  to  the  electropositive  side  of 
hydrogen. 

Arbitrarily,  elements  electronegative  to  hydrogen  are  considered  as 
the  electronegative  elements,  those  electropositive  to  hydrogen  as  electro- 
positive elements, 

A  similar  separation  takes  place  in  the  electrolysis  of  compounds 
containing  more  than  two  elements,  one  element  being  liberated  at 
one  pole  and  the  remaining  group  of  elements   separating  at  the 


ACIDS,  BASES  AND  SALTS  63 

other.  This  primary  decomposition  is  generally  modified,  as  to  its 
final  products,  by  subsequent  chemical  reactions,  called  secondary 
actions.  When,  for  example,  a  solution  of  potassium  sulfate  is  elec- 
trolyzed,  the  liquid  surrounding  the  positive  electrode  becomes  acid 
in  reaction,  and  gives  off  oxygen.  At  the  same  time  the  liquid  at  the 
negative  side  becomes  alkaline,  and  gives  off  a  volume  of  hydrogen 
double  that  of  the  oxygen  liberated.  In  the  first  place  potassium 
sulfate,  which  consists  of  potassium,  sulfur  and  oxygen,  yields  on 
primary  separation  electropositive  potassium,  which  separates  at  the 
negative  pole;  and,  an  electronegative  group  of  sulfur  and  oxygen, 
which  goes  to  the  positive  pole:  2K2S04  =  2K2+2S04.  The  potas- 
sium liberated  immediately  decomposes  the  surrounding  water,  form- 
ing caustic  potash,  to  which  the  alkaline  reaction  is  due,  and  hydro- 
gen, which  is  liberated:  2K2H-4H20  =  4KHO+2H2.  The  sulfur- 
oxygen  group  at  the  positive  pole  also  immediately  reacts  with  water  to 
form  sulfuric  acid,  and  oxygen  is  liberated :  2S04+2H20=2H2S04+02; 
one  molecule  of  oxygen  being  liberated  for  every  two  of  hydrogen. 
(Seep.  70.) 

In  the  electrolysis  of  an  oxacid  (below)  that  group  which  is 
primarily  separated  at  the  positive  electrode  is  called  the  residue  of 
the  acid.    (See  p.  84.) 

Acids,  Bases  and  Salts. — All  ternary  and  quartenary  mineral 
substances  have  one  of  three  functions.  The  function  of  a  substance 
is  its  chemical  character  and  relationship,  and  indicates  certain  gen- 
eral properties,  reactions  and  decompositions  which  all  substances 
having  the  same  function  possess  and  undergo  alike.  Function  corre- 
sponds to  the  "family"  of  zoological  and  other  scientific  classifica- 
tions, as  lesser  groups  of  the  same  function  correspond  to  the 
"genera,"  and  individual  chemical  substances  to  the  "species."  Thus 
in  mineral  chemistry  we  have  acids,  bases  and  salts ;  and  in  organic 
chemistry  alcohols,  aldehydes,  acids,  esters,  etc. 

An  acid  is  a  compound  of  an  electronegative  element  or  residue  ivith 
hydrogen,  which  hydrogen  it  can  part  with  in  exchange  for  an  electro- 
positive element,  without  formation  of  a  base.  An  acid  has  also  been 
defined  as  a  compound  body  tvhich  evolves  water  by  its  action  upon  pure 
caustic  soda  or  potash.  This  latter  definition  is  undesirable  in  view  of 
the  existence  of  certain  zinc  and  aluminium  compounds  (pp.  240,  245) 
No  substance  which  does  not  contain  hydrogen  can,  therefore,  be 
called  an  acid.  (For  other  definitions  of  acids,  bases  and  salts,  see 
p.  77.) 

The  basicity  of  an  acid  is  the  number  of  replaceable  hydrogen  atoms 
in  its  molecule, 

A  monobasic  acid  is  one  containing  a  single  replaceable  atom  of 
hydrogen,  as  nitric  acid,  HNO3:   a  dibasic  acid  is  one  containing  two 


64 


MANUAL    OF    CHEMISTRY 


6uch  replaceable  atoms,  as  sulfuric  acid,  H2SO4;   a  tribasic  acid  is 

one  containing  throe  replaceable  hydrogen  atoms,  as  phosphoric  acid, 
H^FOi,  Poly  basic  acids  are  such  as  contain  more  than  one  atom  of 
replaceable  hydrogen.  H 

Hydracids  are  acids  containing:  no  oxygen;  oxacids  or  oxyacids 
contain  both  hydrogen  and  oxygen. 

The  term  base  is  regarded  by  many  authors  as  applicable  to  any 
compound  body  capable  of  neutralizing  an  acid.  It  is,  however,  more 
consistent  with  modern  views  to  limit  the  application  of  the  name  to 
RHch  ternary  compound  SHhstances  as  are  vapfibie  of  entering  into 
double  decomposition  with  acids  to  form  salts  and  water.  They 
may  be  considered  as  one  or  more  molecules  of  water  in  which  one- 
half  of  the  h^'drogen  has  been  replaced  by  an  electropositive  element 
or  radical;  or  as  compounds  of  such  elements  or  radicals  with  one  or 
more  gi'oups,  OH.  Being  thus  considered  as  derivable  from  water, ■ 
they  are  also  known  as  hydroxids.  They  have  the  general  formula, 
Mii(OH)«,  They  are  monatomic,  diatomic,  triatomic,  etc.,  accord- 
ing as  they  contain  one,  two,  three,  etc,  groups  oxhydryl,  or  hy- 
droxyl  (Oil).  As  acids  having  one,  two  or  three,  etc.,  atoms  of  re- 
placeabh?  hydrogen  are  designated  as  monobasic,  dibasic,  or  tribasic 
acids»  etc.,  so  bases  having  one  replaceable  hydroxyl  are  spoken 
of  as  monacid  bases,  those  having  two  as  diacid  bases,  etc. 

The  atomicitif  of  a  compound  is  the  number  of  hydroxtjts  in  its  mole- 
cule, which  it  tmtif  lose  by  their  combi nation  with  the  hydrogen  of 
acids.  Bases  are  said  to  be  monatomic,  mooohydric  or  monacid; 
diatomic,  dihydric  or  diacid,  etc.,  according  as  the  number  of  their 
hydroxyls  is  one,  two,  etc. 

Thiobases,  or  hydrosulfids,  are  componnds  in  all  respects 
resembling  the  bases,  except  that  in  them  the  oxygen  is  replaced  by 
sulfur. 

An  equivalent  of  an  acid  or  base  is  a  quantity  thereof  equal  to 
one  molecule,  divided  by  the  basicity  or  acidity;  or  that  propor- 
tionate Quantity  of  its  molecular  weight  which  contains  only  one 
basic  hydrogen  atom  or  only  one  acid  displaceable  hydroxyl.  Thus*  a 
molecule  and  an  equivalent  of  caustic  potash,  KHO,  both  weigh 
56.16;  a  molecule  of  sulfuric  acid,  H2SO4,  weighs  98.08,  and  an 
equivalent  49.04, 

A  gram -equivalent  (gra:eq.)  of  any  substance  is  a  quantity  thereof 
whose  weiglit  is  that  of  its  equivalent,  expressed  in  grams. 

Equivalents  and  gram -equivalents  of  ions  (p.  72)  are  quantities 
thereof  corresponding  to  the  same  values  of  elements  or  com- 
pounds. 

Concentration. — By  the  ** concentration"  or  "strength"  of  a  solu- 
tion is  understood  the  amount  of  the  solute  in  unit  volume  of  the 


NORMAL   SOLUTIONS 


65 


solution  (not  of  the  solvent).  Various  utilts  are  used  for  the 
expression  of  concentration  r 

In  percentage  solutionsi  strictly,  both  solvent  and  solnte  are 
taken  in  parts  by  weight.  Thus,  a  4  per  cent  solution  of  sodium 
ehlorid  is  made  with  4  gms.  NaCl  and  96  gms.  H2O.  Volume:  per 
cent  solutions  are  usually  more  eonveuieot:  A  4  per  cent  solution  of 
sodium  ehlorid  is  made  by  dissolving  4  gms.  NaCl  in  a  volume  of 
water  such  that  the  finished  sulutiou  measures  KX)  cc.  The  difference 
between  per  cent  and  v  per  cent  solutions  is  more  marked  with  solvents 
other  than  water.  While  per  cent  solutions  are  independent  of  tem- 
perature, v  per  cent  solutions  have  the  concentration  indicated  only 
at  the  temperature  for  which  they  are  made,  which  is  usually  18°C. 

Norma]  solutions  are  of  two  kinds:  Molecular-nDrmal,  which 
contain  one  gram -molecule  in  a  liter  of  solution,  and  Equivalent- 
normalt  which  contain  one  gram -equivalent  in  a  liler.  Thus,  one 
Uter  of  M-N  solution  of  sulfuric  acid  contains  98.08  gms,  H2HO4,  and 
one  liter  of  Eq-N  solution  4^.04  gms.  Usually  "normar"  solutions 
ire  molecular-normal,  except  solutions  used  in  volumetric  analysis, 
which  are  equivalent -normal,  whole  or  fraetiouaL    Decinorinal  solu* 

tions  (iq)  contain  1^  gm:moL  or  gmreq.  per  liter,  etc.    Standard 

solutions  are  sohitions  of  some  fixed  volume-concentration,  which 
may  Ue  of  any  value  desired  for  the  use  intended. 

A  theoretical  measure  of  couf^entration,  frequently  used  in  elec- 
tTolytic  calculations,  and  designated  by  the  symbol  »?,  is  in  gram- 
*qtiivalents  in  one  ec,  although  tiiis  degree  of  concentration  very 
'rtquently  cannot  be  actualh'  attained, 

SqU^  are  sub.^tanres  fornif'd  by  the  sttbstitutlon  of  ehciroposHive ,  or 
ks^fkns,  elenumts  for  a  pari  or  all  of  the  replaeeahif  hydrogen  of 
n^ids.  They  are  formed,  therefore,  when  bases  and  acids  enter  into 
iouiile  decomposition.  They  are  not,  as  was  formerly  supposed, 
tormed  by  the  union  of  a  metallic  with  a  non-metallic  oxid,  but,  as 
stated  above,  by  the  substitution  of  one  or  more  atoms  of  an  element 
<>r radical  for  the  liydrogen  of  the  acid.  Tlius»  the  compound  formed 
^Xthe  action  of  sulfuric  acid  upon  slaked  lime  is  not  SOaCaO,  but 
Ci80i,  formed  by  the  interchange  of  atoms: 


Hr- 


— Ca 


and  not 


S.1 


S1— = 


It  is,  therefore,  calcium  sulfate,  and  not  sulfate  of  lime. 

As  salts  are  produced  by  double  decomposition  between  acids  and 
k<li08,  the  latter  play  as  much  part  in  the  formation  of  salts  as  do  the 
former,  and  we  may  also  consider  the  salts  as  substances  formed  by 

0 


66  MANUAL    OF    CHEMISTRY 

the  substitution  of  add  residues  (p.  84)  for  a  part  or  all  of  the 
hydroxy  I  of  bases. 

It  will  be  seen  from  the  above  that  in  some  salts  the  hydrogen  of 

the  acid  is  only  partly  replaced,  as  in  baking  soda:  OC\Qg*.     Such 

salts  are  called  bi  salts  or  acid  salts.  There  exist,  also,  salts  in 
which  a  portion  of  the  hydroxyl  of  the  bases  is  retained.  Such  sajts 
are  called  basic  salts,  e.  g.,  basic  lead  nitrate  NOsPbOH.    (See  p.  83.) 

The  term  salt,  as  used  at  present,  applies  to  the  compounds  formed 
by  the  substitution  of  a  basylous  element  for  the  hydrogen  of  any 
acid;  and  indeed,  as  used  by  some  authors,  to  the  acids  themselves, 
which  are  considered  as  salts  of  hydrogen.  It  is  probable,  however, 
that  eventually  the  name  will  be  limited  to  such  compounds  as  corre- 
spond to  acids  whose  molecules  contain  more  than  two  elements. 
Indeed,  from  the  earliest  times  of  modern  chemistry  a  distinction  has 
been  observed  between  the  haloid  salts,  i.e.,  those  the  molecules  of 
whose  corresponding  acids  consist  of  hydrogen,  united  with  one  other 
element,  on  the  one  hand;  and  the  oxysalts,  the  salts  of  the  oxacids, 
i.  e.,  those  into  whose  composition  oxygon  enters,  on  the  other  hand. 
This  distinction,  however,  has  gradually  fallen  into  the  background, 
for  the  reason  that  the  methods  and  conditions  of  formation  of  the 
two  kinds  of  salts  are  usually  the  same  when  the  basylous  element  be- 
longs to  tliat  class  usually  designated  as  metallic. 

There  are,  however,  important  differences  between  the  two  classes 
of  compounds.  There  exist  compounds  of  all  of  the  elements  corre- 
sponding to  the  hydracids,  binary  compounds  of  chlorin,  bromin» 
iodin  and  sulfur.  There  is,  on  the  other  hand,  a  large  class  of  ele- 
ments the  members  of  which  are  incapable  of  forming  salts  corre- 
sponding to  the  oxacids.  No  salt  of  an  oxacid  with  any  one  of  the 
elements  usually  classed  as  metalloids  (excepting  hydrogen)  has  been 
obtained. 

Haloid  salts  may  be  formed  by  direct  union  of  their  constituent 
elements;  oxysalts  are  never  so  produced. 

Osmotic  Pressure. — We  have  seen  (p.  18)  that  if  water  be  floated 
upon  the  surface  of  a  solution  of  sugar,  diffusion  begins  at  once,  and 
continues  until  the  solution  and  the  solvent  constitute  a  sugar  solu- 
tion of  uniform  concentration  throughout.  If,  in  place  of  bringing- 
the  solution  and  the  solvent  into  direct  contact,  they  be  separated  by 
placing  the  sugar  solution  in  a  porous  earthenware  jar  in  which  a 
Pfeffer's  semi-permeable  membrane  (p.  19)  has  been  formed,  and 
which  is  closed  and  fitted  with  a  manometer,  and  the  jar  be  then 
immersed  in  water,  the  passage  of  the  water  will  be  unimpeded,  while 
that  of  the  sugar  will  be  arrested.  As  the  water  passes  in,  but  the 
sugar  remains,  the  pressure  in  the  jar  increases  to  a  definite  point. 


OSMOTIC    PRESSURE 


67 


when  it  remains  statiouary.  At  this  point  the  pressure  exerted  by  the 
water  which  has  entered  is  in  eqiuhbrium  with  that  exerted  by  the 
sii^ar  loulet^ules  in  their  endeavor  to  escape,  and  is  the  measure  of 
the  osmotic  pressure  of  the  solution.  Solutions  having  the  same 
osmotic  pressure  are  said  to  be  isosmotic. 

This  pi*essure  follows  laws  similar  to  those  which  govern  gas 
pressures  (pp.  19-23):  It  increases  with  the  concentration.  With  a 
1  per  cent  solution  of  sugar  it  is  0.704  atm.»  with  a  2  per  cent  solu- 
tion, 1.337  atm.,  with  a  4  per  cent  solution  2.739  atm.^  and  with  a  S 
per  cent  solution  4,046  atra.,  the  pressures  increasing  very  nearly  iu 
the  pn»portion  1:2:4:6.  Therefore,  the  osmotic  pressure  is  propor- 
tionate  to  the  concentration,  or  in  verse  Itf  proportionute  to  the  volume  in 
which  a  given  quantittf  of  the  substance  is  dissolved.  This  corresponds 
to  the  Boyle* Mar iotte  law  of  gases;  vp  =  constant.  Further,  we  have 
§eea.  pp.  19,  25,  that  at  high  pressures  gases  do  not  rigorously  obey 
the  Boyle -Mar  iotte  law,  and  similarly,  it  has  been  found  that  the 
osmotic  pressures  of  concentrated  solutions  (measured  indirectly) 
vary  in  precisely  tlie  same  manner  from  those  calculated  in  obedience 
the  rule* 

The  osmotic  pressure  increases  with  rise  of  temperature.  Thus, 
with  a  1  per  cent  solution  of  sugar  it  is  0.664  atm.,  at  6.8°;  0.684 
tlm.  at  15.5"*,  and  0.716  atm.  at  32°;  from  which  the  pressure  at  0° 
wottld  be  0.65  atm.  These  values  correspond  very  nearly  to  the  for* 
maU:  P=0.65  (1 +.00367  0,  in  which  the  temperature  coemcient 
,00367  is  the  same  as  in  the  gas  formula.  Therefore,  osmotic  pressure 
i»  proportionate  to  the  absolute  innperatur^.  That  is,  it  obeys  the 
Daltori'GayLussac  law  (p.  23),  and  consequently  Vj3  — RT,  as  in  the 
geun-al  gas  law  (p.  24). 

Further,  if  342.22  gras.,  one  gm;mol.,  of  sugar  be  dissolved  in 
,22,1  liters  of  water,  the  solution  is  one  of  1.532  per  cent,  and,  as  the 
motic  pressure  of  a  1  per  cent  solution  is  0.65  atm.  at  0*^,  that  of 
the^m:mol.  solution  in  22.4  is  one  atm*  (0.996).  This  corresponds 
with  the  fact  that  the  pressure  of  a  gm:moL  of  gas  occupying  22.4 
Jiteni  is  one  atm.  (p.  57).  Aod  it  has  been  shown  by  indirect 
roi'tlioda  that  solutions  of  other  substances  containing  1  gm:mol.  in 
22.4  liters  exert  an  osmotic  pressure  of  one  atm.  Therefore,  equal 
lecates  of  different  substances^  when  dis.solved  in  equal  volumes  of 
*«oIvent,  exert  equal  osmotic  pressures.  Or,  in  the  words  of  Van^t 
Hoff:  Isosmotic  solutions  contain  the  same  fiumber  of  molecules  of 
diiiol^f^  substance  in  a  gimi  volume,  at  a  given  tern  pent  tare  ^  mid  the 
«^r  is  the  same  as  in  an  equal  volume  of  a  perpct  gas  at  the  same 
perature  and  pressure.  This  is  in  conformity  with  the  postulate  of 
Avo(fadm  (p.  52),  and  consequently,  the  osmoUe  pressure  is  the  same 
<^the  gas  pressure  would  be  if  the  solvent  were  removed,  and  the  dis- 


MANUAL.    OF    CHEMI8TEY 


solmd  subsiance  occupied  the  same  volume ^  in  the  gaseous  state,  at  the 

same  temperature,  ^ 

Therefore,  the  osmotic  pressure  of  a  solution  may  be  used  to™ 
determine  the  molecular  weight  of  the  solute,  in  the  same  way  that 
the  density  of  a  gas  or  vapor  is  used  for  that  purpose.  But  thd^ 
accurate  determination  of  osmotic  pressure  is  attended  with  experi-" 
mental  difficulties,  and,  therefore,  the  principle  is  applied  in  indirect 
methods.  Two  such  are  in  common  use,  both  based  upon  the  prin- 
ciple that,  as  the  osmotic  pressure  increases  with  the  concentration, 
it  tends  to  oppose  any  diminution  of  the  volume  of  the  dissoh^ed 
substance,  as  gas  pressure  opposes  the  contraction  of  volume  of  a 
gas.  When  a  solution  is  cooled,  a  point  is  reached  when  the  solvent 
begins  to  separate  as  a  solid,  leaving  the  solute  in  the  nnfrozen 
solvent,  thus  diminishing  the  volume  of  the  former,  and,  therefore, 
by  virtue  of  increased  osmotic  pressure  the  freezing  point  of  the 
solution  is  lower  than  that  of  the  pure  solvent  (p,  29),  On  the  other 
hand,  contraction  of  the  volume  of  the  dissolved  substance  is  pro* 
duced  by  driving^  oflf  the  solvent  by  evaporation  or  by  boiling,  and 
here  again  the  osmotic  pressure  opposes  the  concentration,  and,  there- 
fore, the  vapor  pressure  of  a  solution  is  lower  at  any  given  tempera- 
ture than  that  of  the  pure  solvent  (p,  31),  and 
the  boiling  point  of  the  former  is  consequently 
higher  than  that  of  the  latter  {p.  32).  The  de- 
pression of  the  freezing  point  of  a  solution  and 
the  elevation  of  its  boiling  point  are,  therefore, 
measures  of  the  osmotic  pi-essure,  and,  indirectly, 
they  afford  the  means  of  determining  the  tnole<i^l 
ular  weight  of  the  solute.  " 

Before  the  discovery  of   the  laws  of  osmotic 
pressures,  it  had  been  learned  empirically  that  if 

\[r  the  amount  by  which  the  freezing  point  of  a  solu- 

ji  W  tion  containing  a  fixed  quantity*  of  the  solute  (]■ 

gm.  in  100  cc.)  is  lowered  be  multiplied  by  the 
molecular  weight  of  the  solute,  a  constant  quan- 
tity is  obtained  for  each  solvent.  This  is  known 
as  the  Law  of  Raoult«  and  is  equivalent  to  the 
statement  that  equhnolecuhtr  quantities  of  different 
sabstances  dissoited  in  a  given  advent  produce  the 
same  depression  of  the  freezing  point  of  the  solu- 
tion. The  constant  above  referred  to  is  18.5  for 
water,  39  for  glacial  acetic  acid,  and  50  for 
benzene  as  solvents. 

The  usual  form  of  the  apparatus  used  for  the 
Fia.  2s.  determination  of  molecular  weights  by  this  '^cryos- 


OSMOTIC    PRESSUEE 


69 


eopie  method"  is  shown  in  Fig.  23,  in  which  A  is  the  vessel  contain- 
ing the  solvent,  to  which  the  sohite  is  subsequently  added  through 
the  lateral  tube,  and  which  also  contains  a  wire  stirrer*  D  is  a  very 
delicat^e  (BeekmaDD)  thernionieter;  and  C  is  the  vessel  containing 
the  cooling  mixture,  whose  temperature 
should  be  about  5"^  below  that  of   the  || 

solvent.  The  freezing  point  of  the  sol* 
vent  is  first  accurately  determined,  and 
again  after  addition  of  a  known  weight 
of  the  substance.    The  molecular  weight 

is  obtained  by  the  formula i  M=  TXj-, 

m   which    T   is    the    constant   for    the 

solvent  used,  p  the  weight  of  tbe  sub- 

itance  in  solution,  and  t  the  observed 

depression    of    the    freezing    point    in 

degrees    centigrad.    The  difference    be- 
tween   the    freezing    point   of    certain 

liquids  and  that  of  water  is  represented 

by  the   symbol   A,     Thus,   for   normal 
Wood,  4—0.56°. 

Molecular  weights  may  also  be  deter- 
mined from  the  depression  of  the  vapor 
prpAsui*es  of  solutions;  but,  owing  to 
eiperimeutal  difficulties,  the  consequent 
elevation  of  the  boiling  points  is  resorted 
U)iu  preference.  The  elevation  of  tem- 
perature is  proportionate  to  the  quantity  of  substance  dissolved,  if  it 
be  Qon-volatile.  If  molecular  quantities  be  considered,  equal  eleva- 
tiong  are  observed  witli  solutions  containing  equal  gm  :  mols.  of 
different  substances  in  the  same  volume  of  solvent.  And  with  different 
*<>lv^rits  the  elevations  are  equal  when  the  same  quantity  of  substance 
w  dissolved  in  equal  gm  :mols.  of  the  several  solvents* 

For  the  determination  of  molecular  weights  from  boiling  point 
elevation,  Beekmaun's  apparatus  is  customarily  used.  Tlie  boiling 
8«*k,  A  (Fig.  24)  has  a  platinum  wire  fused  into  the  bottom,  and  is 
Partly  filled  with  glass  pearls  and  angular  fragments  of  platinum  (to 
^timrt',  quiet  boiling),  ami  is  surrounded  by  a  glass  steam  jacket,  B. 
^fjfli  A  and  Ei  are  fitted  with  return  condensers,  Ki  and  K-i,  and  the 
IhMTnotneter  is  fitted  as  shown  in  the  figure.  The  boiling  flask,  with 
"Stoppers  in  both  openings,  is  first  weighed.  The  solvent  is  then  intro- 
Jaccil  to  the  level  show^i,  the  stopper  is  replaced,  and  the  flask  aod 
(•oiiteuts  reweighed.  The  difference  is  the  weight  of  solvent  used 
Tb^  apparatus   is  then   mounted   as  showu   in  the    figure,  and   the 


FlQ.  24. 


70  MANUAL  OF    CHEMISTRY 

boiling:  point  of  the  solvent  is  determined.  A  known  weight  of  the 
substance  is  then  introduced  into  the  boiling  flask,  and  the  boiling 
point  of  the  solution  is  determined.    The  molecular  weight  is  obtained 

by  the  formula:  Mw  =  100  c.^  (f~t)^  ^^  which  Mw  is  the  molecular 
weight;  c,  a  constant  called  the  "molecular  elevation  of  boiling 
point  of  the  solvent";  g,  the  weight  of  substance  used;  O,  the 
weight  of  solvent  used;  ti,  the  boiling  point  after  addition  of  the 
substance;  and  t,  the  boiling  point  of  the  solvent.  The  value  of  c  is 
obtained  from  the  heat  of  vaporization  (p.  33)  of  the  solvent,  by  the 

0.02  T* 
formula:    c  =  -^-^^ — ,  in  which  T  is  the  absolute  boiling  point  of  the 

solvent  and  h  its  heat  of  vaporization  at  its  boiling  point.    Thus,  for 

0  02^  r  373^* 

water:    c= -^gg-g-^— =5.2;   for  ethyl  alcohol  it  is  11.5;    for  ether, 

21.2;  for  acetic  acid,  25.3;   and  for  chloroform,  36.6. 

As  the  osmotic  pressure  obeys  the  gas  laws,  and  as  the  gas  pres- 
sure may  be  calculated  by  the  formula:  />t  =  (lX.00367t)  po  (p.  24), 
so  the  theoretical  osmotic  pressure  may  be  obtained,  in  atmospheres, 
by  the  same  formula,  in  which  pi  is  the  osmotic  pressure  at  tempera- 
ture t,  and  Po  the  osmotic  pressure  of  a  1  per  cent  solution  at  0°. 
The  value  of  po  may  be  obtained  from  the  molecular  weight,  as  it 
is  1  atm.  with  a  solution  containing  1  gm:mol.  in  22.4  liters,  or 

224  224  « 

y.  Thus,  for  sugar  ^^4^22^^'^'^^^  ^"^'  if  t  =  15.5°;  pt  =  1.057X 
0.6545  =  0.692  atm.    (See  also  p.  57.) 

We  have  seen,  p.  30,  that  when  a  liquid  and  its  saturated  vapor 
are  in  equilibrium,  the  vapor  pressure  of  the  liquid  is  balanced  by 
the  elastic  force  of  the  vapor;  and  that  a  similar  equilibrium  is 
established  between  a  solid  and  its  saturated  vapor  in  sublimation 
(p.  32).  Now  when  a  solid  is  in  contact  with  its  unsaturated  solu- 
tion, the  former  diffuses  through  the  latter  until  the  solution  becomes 
saturated  (p.  28)  at  a  given  temperature.  The  process  is  then  ended, 
and  there  is  equilibrium  between  the  osmotic  pressure  of  the  solution 
and  that  quality  of  the  solid  which  corresponds  to  the  vapor  pressure 
of  a  liquid.  This  quality  is  called  the  solution  pressure  of  the 
substance,  and  is  equal  to  the  osmotic  pressure  of  its  saturated 
solution. 

As  the  kinetic  theory  of  gases  is  based  upon  the  phenomena 
expressed  by  the  gas  laws  (p.  24),  and  as  osmotic  pressure  obeys 
these  laws,  the  kinetic  theory  of  gases  may  also  be  applied  to  sub- 
stances in  solution,  with  possibly  some  modifications,  which  have, 
however,  not  been  observed,  due  to  collisions  between  the  molecules 
of  the  solute  with  those  of  the  solvent. 

Electrolytic    Dissociation — Ionization — The    observed    osmotic 


ELECTROLYTIC    DISSOCIATION 


71 


lores  of  aqueous  solutions  of  some  substances  agree  very  closely 
with  those  calculated  from  the  gns  law,  but  with  othev  substuuces  iu 
aqueous  solution  the  observed  usTootle  pressui-e  is  bigber  thau  that 
calculated,  and  the  ratio  of  departure  varies  with  different  substauces, 
and  increases  with  the  dilution  of  the  solution.  Those  substances 
which  follow  the  rule  in  the  osmotic  pressure  of  their  aqueous  solu- 
tions are  not  conductors  of  electricity^  and  are  not  electmlyzed  by 
the  galvanic  current.  Those  winch  depart  from  the  rule  form  solu* 
tions  iu  which  they  are  electrolyzed  b^'the  passage  of  the  current,  and 
which  are  conductors  of  the  second  order;  the  conductivity  of  the 
solution  being  the  greater,  the  wider  the  departure  from  the  rule  in 
osmotic  pressure.  These  facts  formed  the  original  foundation  of  the 
theory  of  electrolytic  dissociation  of  Arrhenius,  which  is  further 
strengthened  by  other  facts. 

The  earlier  researches  of  Faraday  (1834)  led  to  the  discovery  of 
the  laws  governing  electrolysis  which  now  bear  his  name.  The  first 
of  these  is  the  effect  that  eleetroltj^h  does  not  occur  mileHS  the  deciro- 
Iffte  is  a  conduetor. 

If  a  current  be  passed  through  several  voltameters  {Fig,  21 »  p.  45) 
nf  different  resistances,  and  having  electronics  of  different  metals,  and 
<liffcring  in  size,  connected  in  series  (p.  43)  in  the  same  circuit,  the 
sHme  volume  of  knall-gas  will  collect  in  each  iu  the  same  time. 
This  is  in  obedience  to  Faraday's  second  law,  usuall}"  referred  to  as 
the  first;  The  energij  of  electrolyftc  action  i'.v  the  sam€  in  ail  parts  of 
a  drcuit. 

If  a  number  of  vessels,  fitted  with  platinum  electrodes,  and  filled 
with  solutions  of  salts  of  different  metals,  be  connected  in  series  iu 
the  same  circuit,  the  weigh t.s  of  the  several  metals  deposited  upon  the 
several  cathodes  will  not  be  equal  to  each  other.  Thus,  if  in  a  given 
time  the  current  deposits  107,93  mgrris,  of  silver,  in  the  same  time  it 
will  havT  deposited  32,7  mgms.  of  zinc,  31.8  nigrns.  of  chopper,  and 
65.7  nigms.  of  gold  from  solutions  of  the  salts  of  those  metals. 
These  are  thf?  proportions  of  the  equivalent  weights  of  the  several 

.neUls:     Ag  =  '-^'  =  107.93;   Z.,  ="-|^=32.7;     C«  =  '';'' =  31.8; 

This  i?  in  accordance  with  the  third  law  of 


Aa  =  ^2  =  65.7 


Paniday,  usually  referred  to  as  the  second;  Mi?  amonnts  nf  different 
Muhgtanefs  deposited  by  the  snmf  qitantity  of  eleetrifify  are  propor- 
ticnatf  to  their  rhemieat  Hpiivalent  n'ffghfs. 

The  electrochemical  equivalent  of  a  substance  is  the  weight  in 
grams  of  that  snl>stance  separated  by  o?ie  coulomb  of  electricity,  or 
bv  11  curi*ent  of  one  ampere  in  a  second.  Thus  the  electrochemical 
equivalent  of  hydrogen  is  0.(KXM>1043,  that  of  silver  is  0.0011175, 
ete.  (p.  45)- 


72 


JAL   OP   CHEMISTRY 


As  one  coulomb  deposits  0.0011175  gm,  of  silver  per  second,  it 
would  require  to  deposit  one  gram -equivalent  (107.93  gmsj  per  second 

107  93 

r-7jT7—g  =  96,581  coulombs,  or  ia  round  numbers  96,600  coulombs. 

This  quantity  of  electricity  is  called  a  Faraday,  and,  as  the  same 

quantity  of  electricity  is  required  to  deposit  a  gram -equivalent  of  any 
other  snbstance,  Faraday- s  laws  may  be  summed  up  in  the  statement: 
(hie  Faraday,  of  96,600  coulombs  of  eleeirkittf,  is  required  to  deposit 
one  grain -equimlent  of  any  substanre.  fl 

The  name  ion  was  first  applied  by  Faraday  to  the  primary™ 
products  of  electrolysis;  and  those  which  separate  at  the  positive 
electrode,  or  anode,  are  called  anions,  while  those  which  separate  at 
the  negative  electrode,  or  cathode,  are  called  cations.  Thus,  potassium 
sulfate  yields  the  cation  K,  and  the  anion  SO4.  Cations  are  desig- 
nated by  the  plus  sign,  anions  by  the  minus  sign.    Thus:  K^SOi^^ 

K  K  +  SO4,  or,  better,  the  cations,  as  well  as  their  valences,  are 
designated  by  the  proper  nomber  of  dots  plaeetl  after  the  symbol » 
thus,  H\  Ca"*,  and  the  anions  similarly  by  prime  marks,  thus,  0H\ 
804^',  and  AsO^''^''.  Hydrogen,  the  metah,  and  basic  radieals  are 
cations;    hydroxyl  and  the  acid  residues  are  anions. 

According  to  the  earlier  views  of  electrolysis,  the  decomposition! 
of  the  molecule  into  its  ions  was  considered  to  be  a  result  of  thef 
action  of  the  galvanic  current.  According  to  the  theory  of  Arrhenius,^ 
dissociation  into  ions,  or  ionization,  occurs  when  the  electrolyte  is 
dissolved.  A  solution  of  potassium  chlorid  contains  not  only  the 
molecular  KCl,  but  also  the  cation  K*  and  the  anion  Cl',  and  the 
action  of  the  current  is  to  separate  these,  already  liberated,  ions  at 
the  respective  electrodes.  It  is  assumed  that  the  hydrogen  and 
metallic  ions  are  cliarged  with  positive  electricity,  and  the  hydroxyl 
and  acid-residue  ions  with  negative  electricity,  and  the?'efore  (p.  39) 
the  former  are  attracted  to  the  negatively  charged  cathode,  and  the 
latter  to  the  positively  charged  anode.  fl 

Nothwithstaudiug  the  apparent  violence  of  the  assumption  that  a' 
substance  having  such  energetic  action  upon  water  as  is  shown  by 
potassium  (p.  222),  can  exist  in  aqueous  solution,  which  assumption 
can  only  be  reconciled  with  observed  facts  by  the  further  supposition 
that  in  the  ionic  form  potassium  constitutes  an  allotropic  modifica- 
tion (p,  17)  differing  from  that  in  the  atomic  or  molecular  forms, 
the  theory  of  electrolytic  dissociation  on  so  In  f  ion  is  now  generally 
accepted.  Moreover,  it  not  only  offers  reasons  for  the  occurrence  of 
certain  observed  facts,  which  it  is  difficult  to  explain  otherwise,  but 
is  also  of  great  service  in  the  consideration  of  the  reactions  utilized 
in  qualitative  analysis. 

We  have  seen  that,   according  to   the   kinetic   theory  of  gases 


1 
I 


ELECTEOLYTIC    DISSOCIATION 


78 


(p.  25),  the  partic^les  of  a  gas  are  in  constant  tnotioii,  and  that  the 
pressure  of  the  gas  is  proportionate  to  the  number  of  impacts  of  the 
movitig  partieles   upon   the   walls  of   the  containing  vessel  in   unit 
time,  and  therefore  to  the  rapidity  of  the  motion  (dependent  upon 
temperature),    and  to   the   number   of   particles   contained    in   unit 
vohime.    We  have  also  seen  (p.  G7)  that  osmotic  pressure  obeys  the 
same  laws  as  gas  pi*essure»  and  it  may  therefore  be  assumed  that  in  a 
dilute  solution  the  particles  of  the  solute  are  in  motion  among  the 
particles  of  the  solvent  in  the  same  manner  as  are  the  particles  of  a 
gas,  and  that  osmotic  pressure  is  also  proportionate  to  the  number 
of  particles  in  unit  volume,  and  to  the  rapidity  of  the  motion  of  the 
particles.     We  have  already  seen  tliat  osmotic  pressure  is  propor- 
tionate to  the  concentration ,  and  to  the  absolute  temperature  { p.  67 ) . 
Therefore,  if  the  osmotic  pi*essure  at  constant  temperature  be  greater 
than  that  corresponding  to  the  concentration,  i.  e.,  the  number  of 
particles  in  unit  volume,  supposing  the  solute  to  be  present  in  the 
molecular  form,  as  we  have  seen  (p.  71)  is  the  case  in  solutions  of 
electrol\i;es,  but  not  in  solutions  of  non- electrolytes,  it  follows  that, 
while  the  solutions  of  the  latter  contain  a  number  of  particles  equal 
to  the  number  of  introduced  molecules,  those  of  the  former  contain 
a  p-eater  number  of  particles.   This  would  be  the  case  if  a  solution 
of  potassium  chlorid,  for  example,  contains  not  only  the  introduced 
molecules  KCl,  but   also   more  or  less  of  the  dissociated  ions   K' 
and  Cr. 

But  the  degree  of  departure  from  obedience  to  the  law  of  osmotic 
pttssure  is  not  the  same  for  all  electrolytes,  from  which  it  may  be 
inferred  that  the  degree  of  electro  I  tf  tic  dissoeiafion  in  solittion  is  not  the 
Mmc,  oilier  things  being  equal ^  with  different  electrolytes. 

If  we  express  the  concentration  of  a  solution  in  gram  r  equivalents 
cubic  centimeter  (p.  65}  hy  ^  (the  concentration  in  gram requi va- 
ts per  liter,  equivalent -noi-mal  solution,  would  then  be  1000^), 
ftiid,  assuming  that  dissociation  is  not  complete,  if  we  express  the 
^raetioQ  which  is  dissociated  by  y,  then  y  will  be  the  degree  of  dis- 
sociation, i,  e.,  the  number  of  molecules  dissociated,  or  the  number 
of  either  anions  or  cations  liberated.    The  coefficient  of  dissociation 
the  ratio  of  the  dissociated  molecules  to  the  whole  number  of  mole- 
introduced  into  the  solution. 
One  method  of  determining  the  degree  of   dissociation   is  from 
Uie  degree  of  departure  from  obedience  to  the  law  of  osmotic  pres- 
The  number  of  ions  (n)  fiirmed  on  dissociation  of  a  molecule 
*|wndsupon  the  relative  valences  of  the  constituent  atoms  or  groups, 
i^,  potassium  ehlorid,  KCl,  yields  two  ions,  K"  and  CV ;  zinc  sulfate 
two  ions,  Zn"  and  SO/';    potassium  sulfate  three  ions,  K*,  K' 
•fid  80i";    potassium  phosphate  four  ions,  K',  K\  K'  and  PO4'''. 


74  MANUAL    OF    CHEMISTRY 

mt  ^.        «  observed  osmotic  preRSure   .     ,  %»#.»,*«*. 

The  ratio  of  ^ii^,-at^8-,i3tirpr-S«re  '«  ^^°°'^°  ««  ^an't  Hoff's  factor 
and  is  designated  by  the  symbol  /;  whose  value  is  equal  to  unity 
with  non- electrolytes,  and  is  less  than  unity  with  electrolytes.  If 
each  molecule  yields  two  ions  i  =  l+y;    if  three  ions  i  =  l+2y,  and 

if  n  ions  i  =  1+  (n — l)y;  from  which  y  =  ^^.  The  value  of  y,  which 

would  be  unity  with  complete  dissociation,  approaches  that  value  as 
dilution  of  the  solution  becomes  greater.  Thus,  with  potassium 
chlorid  at  a  dilution  of  1000^=1.0  the  value  of  r  =  0.748;  at 
100017  =  0.1,  y =0.853;  at  1000i7=0.01,  y  =  0.934;  at  1000i7= 0.001, 
y =0.973;  at  1000i7  =  0.0001,  y  =  0.987,  and  we  may  assume  that  at 
100017  =  i,  y  would  =  1.0.  Therefore,  the  degree  of  dissociation  in- 
creases with  the  dilution  of  the  solutian. 

The  relation  between  conductance  and  electrolysis,  no  liquid 
being  a  conductor  unless  it  be  an  electrolyte,  nor  an  electrolyte  unless 
it  be  a  conductor,  points  to  a  causative  relation  between  the  two 
phenomena.  The  definite  electrical  relations  of  the  ions  to  the 
electrodes,  and  the  fact  that  ions  are  never  separated  from  the  liquid 
except  at  the  electrodes,  also  point  in  the  same  direction,  and  all  lead 
to  the  now  generally  accepted  view  that  the  ions  are  the  conductors  of 
the  current,  and  that,  becoming  electrified  in  the  manner  above 
indicated,  they  are  transferred  by  repulsion  from  one  electrode,  and 
attra(ition  by  the  other,  carrying  their  charges  to  the  electrode  whose 
polarity  is  opposite  to  their  own.  If  this  be  true  there  must  exist  a 
relation  between  the  conductivity  (p.  42)  of  a  solution  and  the  degree 
of  dissociation  of  the  contained  electrolyte:  the  conductivity  is  directly 
proportionate  to  the  number  of  free  ions  present. 

Taking  as  a  unit  of  conductivity,  f,  that  of  a  body  a  column  of 
which  I  cm,  long  and  1  cm.^  in  cross -section  has  a  resistance  of 
1  ohm  (p.  46),  the  conductivity  of  a  body  of  the  same  magnitude 

having  a  resistance  R  will  be:    '^  =  r^-    The  equivalent  conductivity 

of  an  electrolyte  in  solution,  designated  by  A,  jg  the  conductivity  of  a 
column  1  cm.  long,  and  1  cm.^  in  cross -section,  containing  1  gm:eq. 

of  the  electrolyte  in  1  cc,  or  A  =  — -.    The  molecular  conductivity, 

designated  by  /*,  differs  from  the  equivalent  conductivity  in  that  the 
concentration  of  the  solution  is  1  mol  per  cc,  in  place  of  1  gmreq. 
per  cc.  Clearly  the  values  of  A  and  /*  are  the  same  when  the  equiva- 
lent and  molecular  weights  are  the  same.  The  values  of  A  as  deter- 
mined for  potassium  chlorid  have  been  found  to  be:  at  1000i7=^1.0, 
A  =  98.2;  at  100017  =  0.1.  A  =  111.9;  at  10()0i7  =  0.01,  A=  122.5;  at 
100017  =  0.001,  A  =  127.6;  and  at  IOOO17  =  0.0001,  A  =  129.5;  from 
which  it  has  been  calculated  that  at  100(;i7  =  Jr,  A   would   =131.2. 


ELECTROLYTIC    DISSOCIATION  75 

Therefore,  the  equivalent  conductivity  increases  proportionately  with  the 
dilution;  and  we  have  here  a  second,  independent  means  of  deter- 
mining the  degree  of  dissociation.  If  we  compare  the  value  of  ^  for 
IOOO17  =  i  obtained  by  this  method  with  the  values  given  above,  by 
the  factor  -,  we  obtain  the  very  concordant  values:   131.2,  131.1, 

131.1,  131.1  and  131.2.  Clearly,  the  value  of  y  can  be  calculated  from 
that  of  A  at  any  dilution  by  dividing  the  latter  by  its  value  for 

100017= 1. 

The  degree  of  dissociation  is  increased  by  elevation  of  temperature. 
The  temperatures  usually  selected  for  determinations  are  18°  and  25°. 
At  the  same  temperature  and  dilution  the  degree  of  dissociation  varies 
greatly  with  different  substances.  The  dissociation  constant  of  a 
substance,  designated  by  K,  is  the  measure  of  its  tendency  to  dis- 
sociation. If  17  represent  the  total  concentration,  i.  e.,  the  number  of 
gm:eq.  of  a  binary  electrolyte  in  1  cc,  and  y  the  fraction  thereof 
which  is  ionized,  then  yn  is  the  number  of  anions,  and  the  number  of 
cations  in  1  cc,  and  17(1  —  y)  is  the  number  of  undissociated  molecules. 

Prom  these  values  the  dissociation  constant  is  J5r= -tj— -y.    The  value 

of  K  is  a  measure  of  the  chemical  activity,  or  ^^ strength  "  of  a  substance. 
The  conductivity  of  acids,  and  the  influence  of  dilution  thereupon, 
differ  notably  with  different  acids.  Thus  the  values  of  A  at  the  dilu- 
tions of  100017=1.0;  1000^7=0.1;  1000i7=0.01,  and  1000^7=0.001  are 
respectively  for  hydrochloric  acid:  301,  351,  370  and  377;  for  sul- 
furic acid:  198,  225,  308  and  361:  and  for  acetic  acid  1.32,  4.60, 
14.03  and  41;  showing  that  hydrochloric  acid  is  highly  ionized,  even 
in  the  more  concentrated  solutions,  sulfuric  acid  only  becomes  so  on 
dilution,  and  the  degree  of  ionization  of  acetic  acid  is  small  even  at 
the  higher  dilutions.  While  certain  chemical  reactions,  such  as  the 
solution  of  metals,  the  esterification  of  alcohols,  and  the  hydrolysis 
of  sugars  are  brought  about  by  each  of  these  acids,  the  time  occu- 
pied in  the  reaction  is  the  shortest  with  hydrochloric  acid,  and  the 
longest  with  acetic  acid.  Therefore  hydrochloric  acid  is  the  "strong- 
est" of  the  three  acids  mentioned,  and  acetic  acid  is  the  "weakest"; 
and  the  strength  of  an  acid  is  proportionate  to  its  degree  of  dissociation , 
t.  e.,  to  the  number  of  free  ions  contained  in  its  solution.  And  the 
same  is  also  true  of  bases. 

The  variation  of  conductivity  with  dilution  is  also  utilized  to 
determine  the  basicity  of  acids.  Almost  all  acids  form  soluble  sodium 
salts.  If  the  molecular  conductivity  of  solutions  of  these  be  deter- 
mined at  a  dilution  of  1  mol  in  32  liters,  and  again  at  a  dilution  of 
1  mol  in  1,024  liters,  the  increase  in  conductivity  with  dilution  will  be 
found  to  be  very  nearly  constant  with  sodium  salts  of  acids  of  like 


7t) 


MANUAL    OF    CUEMISTRY 


basicity,  but  different  with  those  of  acids  of  varying  basicity.  The 
mean  difference,  represented  by  ^,  is:  for  monobasic  acids  ^=1X10.4 
=10.4;  for  dibasic  acids  A=2X9. 5^19,0;  for  tri basic  acids  ^=3X 
10,1=30,2;  for  tctrabasic  acids  A=4X  10.3=41.1,  and  for  pentabasic 
acids  ^^^5X10^50.1.  This  method  is  applicable  in  all  cases  except 
when  the  acid  is  so  weak  that  its  sodium  salt  is  hydrolysed  (p»  116)^ 
by  water  sufficiently  to  render  the  solution  alkaline.  ■ 

It  is  not  to  be  inferred  from  what  has  been  said  abo%'^e  that»  upon 
solution  of  an  electrolyte,  a  certain  proportion  of  the  molecules  are 
ionized  and  remain  so,  and  that  the  remainder  of  the  substance  con-fl 
tinues  in  its  molecular  condition;  but  rather  that  a  condition  of 
dj'namie  equilibrium  is  reached,  similar  to  that  between  a  liquid  and 
its  saturated  vapor  (p.  30),  in  which  ionization  and  recombination  of 
ions  to  moleciiles  continue,  the  changes  in  one  direction  being  equal 
to  those  in  the  other,  so  that  their  algebraic  sura  is  zero.  The  ions 
are  also  assumed  to  be  in  constant  motion,  as  are  the  molecules 
(p.  70),  and  liable  to  collision  with  each  other,  followed  by  their 
recombination.  It  is  only  when  the  ions  come  within  the  electric 
field  between  the  electrodes  that  they  acquire  the  continued  motion- 
toward  their  opposite  electrodes  under  the  influence  of  the  electric 
charges.  The  degree  of  dissociation  also  remains  constant  for  the 
existing  temperature  and  dilution,  notwithstanding  the  removal  of 
ions  by  evolution  of  gases,  deposition  of  metals,  etc,  until  the 
extremely  high  dilution  is  reached  when  ionization  is  complete,  and  y 
equals  iinity.  Ions  when  thus  separated  at  the  electrodes  either  imme- 
diately resume  the  molecular  condition,  or  enter  into  secondary  reac* 
lions  (p.  63).  M 

We  have  seen  that  when  an  aqueous  solution  of  an  acid  is  eiec-  ™ 
trolysedp  hydrogen  is  always  given  off  at  the  cathode.  Although  h^^- 
drogen  exists  in  innumerable  compounds  other  than  acids,  it  is  only 
from  them  that  it  is  so  separated,  and  only  from  them  when  in  solu- 
tion. That  this  hydrogen  does  not  originate  from  the  water  is  shown 
by  the  fact  that  perfectly  pure  water  is  neither  a  conductor  nor  an 
electrolyte.  It  is  only  in  solutions  of  acids  (or  in  solutions  of  acid 
salts  or  esters,  which  still  retain  acid  properties),  therefore,  that 
hydrogen  exists  in  the  ionized  form,  as  hydrion-  Hydrion  also 
differs  from  molecular  or  atomic  hydrogen  in  other  respects.  It  is 
only  known  in  solution,  while  molecular  hydrogen  is  almost  insoluble 
in  water.  It  reddens  litmus  and  is  replaceable  by  metals,  properties 
not  possessed  by  either  atomic  or  molecular  hydrogen .  Similarly,  when 
solutions  of  bases  are  electrolyzed  hydroxy K  OH,  is  always  produced 
as  a  primary  product  at  the  anode.  And,  here  again,  although 
hydroxyls  exist  in  many  compounds  other  than  those  having  basi^fl 
properties,  it  is  only  from  solutions  of  these  that  hydroxyl  is  thus 


ELECTROLYTIC    DISSOCIATION^ 


7f 


separated,  as  only  their  solutions  contain  the  ion,  hydroxidion.  And 
hydroxidion  differs  further  from  hydroxjl  in  that  it  is  only  known  in 
solatian,  that  it  blues  reddened  litmus,  and  that  it  is  replaceable  by 
aeid  residues.  Now,  omitting  the  action  of  the  galvanic  current,  and 
invoking^  the  theory  of  Arrhenius  that  solutions  of  acids  and  boses 
pntain  the  free  ions,  and  remembering  that  ionization  is  not  complete, 
I  may  write  the  equation  representiug  the  neutralization  of  an  acid, 
Syd**ochloric»  by  a  base,  caustic  potash,  thus: 

ruB'  I  rjCr-f  ^(l-Y)flCl-h')^K'  I  7'jOH'-fi?(l-7)KOH^yi7K^  1  TirCl'-l-t, 
{1--K)KC1  +  7'?H*  I  7rK)H'+ij(l-7)H20 


hat  is,  the  anion  ehloridion  and  the  cation  potassion  unite  to 
form  potassium  chlorid,  while  the  cation  hydrion  and  the  anion 
bydroxidion  unite  to  form  water;  and,  while  the  molecular  acid  and 
hiise  are  replaced  by  the  molecular  salt  and  water,  the  i^ume  kinds  of 
ioDs  are  present  after  the  neutraUzation  as  existed  in  the  solution 
previous  thereto. 

Upon  the  facts  above  stated  may  be  based  definitions  of  acids, 
bases  and  salts,  which  are  more  concise  than  those  ^iven  on  pp.  63,  65, 
An  acid  is  a  com  pott  ml  yielding  hydrion  on  elect  rolysia* 
A  base  is  a  compound  yielding  hydroxidinn  on  ekrtrolysis, 
A  mil  is  a  compound  formed  by  the  union  of  the  anion  of  an  aeid 
and  thf  cation  of  a  base. 

In  the  light,  also»  of  the  theory  of  electrolytic  dissociation  on  solu- 
tion, the  language  of  the  laws  of  Berthollct,  which  are  generalized 
stitements  of  facts  which  are  the  nnderlying  principles  of  almost  all 
of  the  reactions  utilized  in  qualitative  inorganic  analysis,  may  be 
ttiodified  with  advantage.    These  laws  are  usually  thus  stated: 

1.  When  solutions  of  two  substances  which  can  read  with  each 
^i^fr  to  produce  a  substance  insoluble  in  the  solve ni  are  brouyM 
^Hhr,  such  ijisoluble  substance  is  formed,  and  separates  as  a 
frecipitate. 

2.  When  solutions  of  two  substances  which  can  react  with  each  other 
^  prottuce  a  suhstanre  which  is  gaseous  or  volatile  at  the  iemperatnre 
*^fthe  reaction  are  brought  together^  such  gaseous  or  volatile  substance 
**  priHhiced^  and  escapes  as  a  gas  or  vapor. 

Thf  substances  here  under  consideration  are  acids,  bases  and  salts, 
^hieh  are  electrolytes,  and  whose  solutions  therefore  contain  the  free 
'onj!.  When  a  solution  of  sodium  chlorid  is  added  to  a  solution  of 
stiver  nitrate,  the  insoluble,  and  therefore,  non- ionized  silver  chiorid 
Wpftrates,  and  the  solution  contains  sodium  nitrate:  NaCI  +  AgNOa 
"AgCl+NaNOa,  or,  from  the  point  of  view  of  ionization,  the 
ttioD  ehloridion  unites  with  the  cation  argention  to  form  the  insolu- 


78  MANITAL    OF    CHEMISTRY 

ble,  molecular  silver  ehlorid,  and  the  solution,  after  the  reaction, 
contains  molecular  sodium  nitrate,  along  with  sodion  and  nitranion: 
Na*  I  Cl'+Ag- 1  N03'=AgCl+Na*  I  NO3'.  This  property  of  chloridioa 
is  manifested  whatever  may  be  the  cation  with  which  it  is  associated, 
whether  it  be  hydrion  or  any  metallic  ion.  It  is,  however,  a  property 
peculiar  to  chloridion,  and  is  not  manifested  by  chlorin  in  the  molec- 
ular form  or  in  any  form  of  combination,  whether  molecular  or  ionic. 
Thus  the  reaction  does  not  occur  between  solutions  of  silver  nitrate 
and  sodium  chlorate,  although  the  latter  contains  chlorin,  because  on 
solution  it  does  not  produce  chloridion  but  the  compound  ion  chloran- 
ion:  Na'  |  CIO3'.  Similarly,  when  a  solution  of  cupric  sulfate  and  one 
of  caustic  potash  are  mixed,  the  cation  cu prion  and  the  anion  hy- 
droxidion  unit  to  form  the  insoluble,  molecular  cupric  hydroxid: 
Cu"  I  S0/'+2K-  I  0H'=K2"  I  SO/'+CuH202;  and  this  reaction  of 
cuprion  is  manifested  whatever  may  be  the  anion  with  which  it  is 
associated.  Again,  when  solutions  of  caustic  potash  and  ammonium 
ehlorid  are  brought  together  at  a  moderately  elevated  temperature, 
the  unstable  ammonium  hydroxid  which  would  otherwise  result  from 
the  cation  ammonion  and  the  anion  hydroxidion  is  decomposed  to 
water  and  gaseous  ammonia:  K*  |  OH'+NH*'  |  Cr=K*  |  C1'+NH4*  I 
OH'=K'  I  C1'+H20+XH3.  Therefore,  the  properties  of  the  ions  are 
manifested  irrespective  of  the  nature  of  the  ions  of  opposite  polarity 
with  which  they  are  associated. 

As  solution  is  a  necessary  preliminary  to  the  formation  of  pre- 
cipitates, and  as  these  are  produced  by  the  combination  of  ions  when- 
ever such  union  can  produce  a  molecule  insoluble  in  the  solvent 
present,  and  as  ions  may  be  removed  from  solutions  of  electrolytes, 
not  only  by  precipitation  of  insoluble  products,  but  also  by  escape  of 
gaseous  or  volatile  products,  the  laws  of  Berthollet  may  be  united  in 
the  statement:  When  two  ions  may  unite  to  form  a  molecule  insoluble 
in  the  solvent,  or  gaseous  or  volatile  at  the  existing  temperature,  such 
insoluble,  gaseous,  or  volatile  substance  is  produced  and  removed  from- 
the  solution  by  precipitation  or  evolution. 

Stoichiometry  {(jtolx€iov  =  sm  element;  fi€Tpov  =  a  measure) — in 
its  strict  sense  refers  to  the  law  of  definite  proportions,  and"  to  its- 
applications.  In  a  wider  sense,  the  term  applies  to  the  mathematics- 
of  chemistry,  to  those  mathematical  calculations  by  which  the  quanti- 
tative relations  of  substances  acting  upon  each  other,  and  of  the 
products  of  such  reactions  ai'c  deteniiiiied. 

A  chemical  reaction  can  always  be  expressed  by  an  equation, 
which,  as  it  represents  not  only  the  nature  of  the  materials  involved, 
but  also  the  number  of  molecules  of  each,  is  a  quantitative  as  well  as 
a  qualitative  statement. 

Let  it  be  desired  to  determine  how  much  sulfuric  acid  will  be  re- 


CHEMICAL    COMBINATION  79 

qnired  to  completely  decompose  100  parts  of  sodium  nitrate,  and  what 
will  be  the  nature  and  quantities  of  the  products  of  the  decomposi- 
tion.  First  the  equation  representing  the  reaction  is  constructed: 

H,804  +  2NaN03  =  NaaSO*  +  2HN08 

Snlfaric  add.  Sodhun  nitrate.  Disodic  sulfate.  Nitric  acid. 

which  shows  that  one  molecule  of  sulfuric  acid  decomposes  two  mole* 
cules  of  sodium  nitrate,  with  the  formation  of  one  molecule  of  sodium 
sulfate  and  two  of  nitric  acid.  The  quantities  of  the  different  sub- 
stances are,  therefore,  represented  by  their  molecular  weights,  or 
some  multiple  thereof,  which  are  in  turn  obtained  by  adding  together 
the  atomic  weights  of  the  constituent  atoms: 

H2SO4         +         2NaN03         =         Na2804         -f         2HNOs 

1.01X2=  2.02    23.05X1=23.05  23.05X2=46.10      1.01X1=  1.01 

32.06X1=32.06    14.04X1=14.04  32.06X1=32.06    14.04X1=14.04 

16     X4=64.00     16      X3=48.00  16      X4=64.00    16      X3=48.00 

98.08  85.09X2=170.18      142.16  63.05X2=126.10 

Consequently,  98.08  parts  H2SO4  decompose  170.18  parts  NaNOg, 
and  produce  142.16  parts  Na2S04,  and  126.10  parts  HNOs.  To  find 
the  result  as  referred  to  100  parts  NaNOs,  we  apply  the  simple 
proportion : 

170.18  :  100::  98.08  :  57.63— 67. 63=part8  H2SO4  required. 
170.18  :  100::142.16  :  83.53—83.53=     "     NaaSOi  produced. 
170.18  :  1001:126.10  :  74.10—74.10=     **     HNO3  " 

As  in  writing  equations  (see  p.  61),  the  work  should  always  be 
proved  by  adding  together  the  quantities  on  each  side  of  the  equality 
sign,  which  should  equal  each  other:  98.08+170.18  =  268.26  = 
142.16+126.10  =  268.26,  or  57.63+100=157.63  =  83.53+74.10  = 
157.63. 

Ill  determining  quantities  as  above,  regard  must  be  had  to  the 
pnrity  of  the  reagents  used,  and,  if  they  be  crystallized,  to  the 
amount  of  water  of  crystallization  (see  p.  17)  they  contain. 

Let  it  be  desired  to  determine  how  much  crystallized  cupric  sulfate 
can  be  obtained  from  100  parts  of  sulfuric  acid  of  92  per  cent  strength. 
As  copric  sulfate  crystallizes  with  five  molecules  of  water  of  crystalli- 
Mtion,  the  reaction  occurs  according  to  the  equation: 

H28O4         -f         CuO        -f         4H2O  =  CuS045Aq. 

Snlfnrie  add.  Cuprlr  oxid.  Water.  Cnprie  sulfate. 

63.6  1.01X2=2.02                      63.6X1=63.60 

1.01X2=  2.02            16.0  16      X1=1C.00                      32.06X1=32.06 

32.06X1=32.06  16      X4=64.00 

16      X4=64.00  18.02X6=90.10 

98.08  79^6  18!02X4=72.08  249.76 

98.08+79.6+72.08=249.76 


80  MANUAL    OF    CHEMISTRY 

98.08  parts  of  100  per  cent  H2SO4  will  produce,  therefore,  249.76 
parts  of  crystallized  cupric  sulfate.  But  as  the  acid  liquid  used  con- 
tains only  92  parts  of  true  H2SO4,  in  100;  100  parts  of  such  acid 
will  yield  234.27  parts  of  crystallized  sulfate,  for  98.08:92:: 249.76: 
234.27. 

In  gravimetric  quantitative  analysis  the  substance  whose  quan- 
tity is  to  be  determined  is  converted  into  an  insoluble  compound, 
which  is  then  purified,  dried  and  weighed,  and  from  this  weight  the 
desired  result  is  calculated. 

Let  the  problem  be  to  determine  what  percentage  of  silver  is  con- 
tained in  a  silver  coin.  Advantage  is  taken  of  the  formation  of  the 
insoluble  silver  chlorid.  A  piece  of  the  coin  is  chipped  oflf  and 
weighed:  weight  of  coin  used  =  2.5643  grams.  The  chip  is  then  dis- 
solved in  nitric  acid,  forming  a  solution  of  silver  nitrate.  From  this 
solution  the  silver  is  precipitated  as  chlorid,  by  the  addition  of  hydro- 
chloric acid,  according  to  the  equation: 

AgNOa  +  HCl         =        AgCl  +  HNO3 

Silver  nitrate.  Hydrochloric  acid.    Silver  chlorid.  Nitric  acid. 

107.93X1=107.93  1.01  107.93  1.01X1=    1.01 

14.04X1=    14.04  35.46  35.45  14.04X1=14.04 

16      X3=   48.00  16       X  3  =  48.00 


169.97  36.46  143.38  63.05 

169.97  +  36.46  =  206.43  =  143.38  -f-  63.05 

The  silver  chlorid  is  collected,  dried  and  weighed: 

Weight  of  coin  used 2.5643  grams 

Weight  of  AgCl  obtained 3.0665      *' 

as  143.38  grams  AgCl  contain  107.93  grams  Ag  — 143.38:107.93:: 
3.0665:2.3080  —  2.5643  grams  of  the  coin  contain  2.3080  grams  of 
silver,  or  90  per  cent— 2. 5643: 100::  2.3080:90. 

Nomenclature. — The  names*  of  the  elements  are  mostly  of  Greek 
derivation,  and  have  their  origin  in  some  prominent  property  of  the 
substance.  Thus, phosphorus,  <^5»  light,  and  <t>€p€Lv,  to  hear.  Some  are 
of  Latin  origin,  as  silicon,  from  silex,  flint;  some  of  Gothic  origin, 
as  iron,  from  iarn;  and  others  are  derived  from  modern  languages, 
as  potassium  from  pot-ash,  Ver>'  little  system  has  been  followed  in 
naming  the  elements,  beyond  applying  the  termination  inm  to  the 
metals,  and  m  or  on  to  the  non-metals;  and  even  to  this  rule  we  find 
such  exceptions  as  a  metal  called  manganese  and  a  non-metal  called 
sulfur. 

The  names  of  compound  substances  were  formerly  chosen  upon  the 

•For  rules  soyemiug  orthography  and  pronunciation  of  chemical  terms,  see  Appendix  A. 


CHEMICAL    COMBINATION 


81 


same  system,  or  rather  lack  of  system ^  as  those  of  the  elements.  So 
loQgas  the  number  of  eompoimds  with  which  the  chemist  had  to  deal 
remained  small,  the  use  of  these  fimeiful  appellations,  conveying  no 
more  to  the  mind  than  perhaps  some  unimportant  quality  of  the  sub- 
stances to  which  they  applied,  gave  rise  to  comparatively  little  incon- 
venienee.  In  these  later  days,  however,  when  the  number  of 
eompotinds  known  to  exist,  or  whose  existence  is  shown  by  approved 
tliPor>'  to  be  possible,  is  practicaily  infinite,  some  systematic  method 
of  Ufiinenclature  has  become  absolutely  necessary. 

Th^  principle  of  the  s^fstem  of  nomenelature  at  present  nsed  is  thai 
iht  name  shall  convey  ike  eomposifiim  and  character  of  the  substancf^ 

Compounds  consisting  of  two  elements,  or  of  an  element  and  a 
radical  only,  binari/  com pou fids,  are  designated  by  compound  names 
made  up  of  the  name  of  the  more  electro- positive,  followed  by  that 
of  the  more  electro -negative,  in  which  the  termination  id  has  been 
*iubstitated  for  the  termination  in,  on,  ogen,  tffjeji,  orns,  it(m,  and  in\ 
For  example:  the  compound  of  potassium  and  cliloriu  is  called  potas- 
mm  chlorid,  that  of  potassium  and  oxygen  potassium  oxiV/,  that  of 
potassium  and  phosphorus  potassium  phosphi¥. 

lo  a  few  instances  the  older  name  of  a  compound  is  used  in  prefer- 
«aoe  to  the  one  which  it  should  ha%^e  under  the  above  rule,  for  the 
wagon  that  the  substance  is  one  which  is  typical  of  a  number  of  other 
iabfitances,  and  tlierefore  deserving  of  exceptional  pmminence.  Such 
are  ammonia,  NH^j    water,  H2O. 

When,  as  frequently  happens,  two  elements  unite  with  each  other 
lo  form  more  than  one  compound,  these  are  usually  distinguished 
froiu  each  other  by  prefixing  to  the  name  of  the  element  varying  in 
amount  the  Greek  numeral  corresponding  to  the  number  of  atoms  of 
tliat  element,  as  compared  with  a  fixed  number  of  atoms  of  the  other 
element. 

Thus,  in  the  series  of  compounds  of  nitrogen  and  oxygen,  most  of 
'^hicli  contain  two  atoms  of  nitrogen,  N2  is  the  standard  of  compari- 
0^1  and  consequently  the  names  are  as  follows : 

N;jO  ^  NUrogen  monoxide 

NO   {=  N2O2)  ^  Nitrogen  diox'id. 
NiOi  =^  Nitrogen  fnoxid, 

NOi  (=  NjO*)  =  Nitrogen  ^f  ^roxid. 
N2O5  =  Nitrogen  penfoxid* 

Another  method  of  distinguishing  two  compounds  of  the  same 
two  elements  consists  in  terminating  the  first  word  in  ous  in  that 
<^nipoand  which  contains  the  less  proportionate  quantity  of  the  more 
deeh'o- negative  element,  and  in  ic  in  that  containing  the  greater  pro- 
rf>rtioii;  thus; 
6 


82  MANUAL    OF    CHEMISTRY 

SO2  =  Sulf upotw  oxid. 
SOa  =  Sulfario  oxid. 

Hg2Cl2  (2Hg  :  2C1)  =  Mereurotw  chlorid. 
HgCl2    (2Hg  :  4CI)  =  Mercuric  chlorid. 

This  method,  although  used  to  a  certain  extent  in  speaking  of  com- 
pounds composed  of  two  elements  of  Class  III  (see  p.  101),  is  used 
chiefly  in  speaking  of  binary  compounds  of  elements  of  different 
classes. 

In  naming  the  oxacids  the  word  acid  is  used,  preceded  by  the  name 
of  the  electro -negative  element  other  than  oxygen,  to  which  a  prefix 
or  suffix  is  added  to  indicate  the  degree  of  oxidation.  If  there  be  only 
two,  the  least  oxidized  is  designated  by  the  suffix  ous,  and  the  more 
oxidized  by  the  suffix  tr,  thus: 

HNO2  =  Nitroiw  acid. 
HN03  =  Nitric  acid. 

If  there  be  more  than  two  acids,  formed  in  regular  series,  the  least 
oxidized  is  designated  by  the  prefix  hypo  and  the  suffix  ous;  the  next 
by  the  suffix  ous;  the  next  by  the  suffix  ic;  and  the  most  highly 
oxidized  by  the  prefix  per  and  the  suffix  ic;  thus: 

HCIO  =  HypochloTOus  acid. 
HCIO2  =  ChloroM*  acid. 
HCIO3  =  Chloric  acid. 
HCIO4  =  Perchlonc  acid. 

Certain  elements,  such  as  sulfur  and  phosphorus,  exist  in  acids 
which  are  derived  from  those  formed  in  the  regular  way,  and  which 
are  specially  designated. 

The  names  of  the  oxysalts  are  derived  from  those  of  the  acids  by 
dropping  the  word  acid,  changing  the  termination  of  the  other  word 
from  ous  into  ite,  or  from  ic  into  ale,  and  prefixing  the  name  of  the 
electro -positive  element  or  radical;   thus: 

HNOo  KNO2 

Nitroti«  acid.  Potassium  nitrify. 

HNO3  KNO3 

Nitric  acid.  Potassium  nitraff. 

HCIO  KCIO 

Hypochlorouf  acid.  Potassiom  hypochlon^«. 

Acids  whose  molecules  contain  more  than  one  atom  of  replace- 
able hydrogen  are  capable  of  forming  more  than  one  salt  with  electro- 
positive elements,  or  radicals,  whose  valence  is  less  than  the  basicity 
of  the  acid.  Ordinary  phosphoric  acid,  for  instance,  contains  in  each 
molecule  three  atoms  of  basic  hydrogen,  and  consequently  is  capable 


CHEMICAL   COMBINATION  83 

of  forming  three  salts  by  the  replacement  of  one,  two,  or  three  of  its 
hydrogen  atoms,  by  one,  two,  or  three  atoms  of  a  univalent  metal. 
To  distinguish  these  the  Greek  prefixes  mono,  di,  and  iri  are  used,  the 
termination  ium  of  the  name  of  the  metal  being  changed  to  tc,  thus: 

H2KPO4  =  ifonopot«88ic  phosphate. 
HK2PO4  =  Z>ipota88ic  phosphate. 
K3PO4     =  IVipotasstc  phosphate. 

The  first  is  also  called  dt'Aydropotassic  phosphate,  and  the  second, 
Ajfdrodipotasstc  phosphate. 

In  the  older  works,  salts  in  which  the  hydrogen  has  not  been 
entirely  displaced  are  sometimes  called  bisalts  (bicarbonates),  or  acid 
salts;  those  in  which  the  hydrogen  has  been  entirely  displaced  being 
desig^nated  as  neutral  salts. 

Some  elements,  such  as  mercury,  copper,  and  iron,  form  two  dis- 
tinct series  of  salts.  These  are  distinguished,  in  the  same  way  as  the 
acids,  by  the  use  of  the  suffix  ous  in  the  names  of  those  containinj? 
the  less  proportion  of  the  electro -negative  group,  and  the  suffix  ic  in 
those  containing  the  greatest  proportion,  e.g.: 

(Cii2)804 (ISO4  :  2Cu)  =  Cuprous  sulfate. 

Cii804 (2SO4 :  2Cu)=Cuprkj  sulfate. 

PeS04 (2SO4  :  2Fe)  =  Ferrous  sulfate. 

(Pea)  (804)3 (3SO4  :  2Fe)  =  Ferric  sulfate. 

The  names,  basic  salts,  subsalts  and  oxy salts  have  been  applied 
indifferently  to  salts,  such  as  the  lead  subacetates,  which  are  com- 
pounds containing  the  normal  acetate  and  the  hydroxid  or  oxid  of 
M;  and  to  salts  such  as  the  so-called  bismuth  subnitrate,  which  is 
a  nitrate,  not  of  bismuth,  but  of  the  univalent  radical  (Bi'''O'0^ 

By  double  salts  are  meant  such  as  are  formed  by  the  substitution 
<»f  different  elements  or  radicals  for  two  or  more  atoms  of  replacea- 
We  hydrogen  of  the  acid,  such  as  ammonio-magnesian  phosphate, 
^i^g'  (NH4)'. 

In  naming  the  cations,  the  termination  ion  is  added  to  the  stem  of 
the  name  of  the  metal,  the  Latin  name,  if  it  exist,  being  used;  but 
*orfton,  not  natrion,  and  potassion,  not  kalion.  Ionized  hydrogen  is 
called  hydrion.  The  names  of  the  anions  are  derived  from  those  of 
the  corresponding  salts  by  changing  the  terminations  from  id  to  idion, 
^'ttS^^=9ulfidi(m;  ite  to  osion,  e.  g.,  SO3  ^=mlfosion;  and  ate  to 
«»um,  e.  g.,  S04=^8ulf anion;  except  CO3''  is  called  carbanion.  The 
•nion  OH  is  called  hydrozidion.  When  ions  of  different  valence  are 
derived  from  the  same  substance  they  are  distinguished  by  the  corre- 
sponding Greek  numerals.  Thus  the  electrolysis  of  H2SO4  proceeds  in 
two  stages,  first  H2S04  =  H'  |  B^Oi'=  monosnlf anion,  then  HS04  = 
R'\S04'=disulf anion. 


u 


MANUAL    OF    t'HEMlSTEY 


Radicals* — Many  uorapounds  contain  groups  of  atoms  whieb  pass 
from  one  compound  to  another,  and,  in  many  react  Ions,  behave  like 
elementary  atoms.  Such  groups  are  called  radicals,  or  compound 
radicals. 

Marsh  gas  has  the  composition  CH4.  By  acting  upon  it  in  suitable 
ways  we  can  cause  the  atom  of  carbon,  accompanied  by  three  of  the 
hydrogen  atoms,  to  pass  into  a  variety  of  other  compounds,  such  as 
(CHa)Cl,  (CH3)OH,  {CttO-O,  C.II3O2  (CH-,).  Marsh  gas,  therefore, 
consists  of  the  radical  {CH3)  combined  with  an  atom  of  hydrogen: 
(CH:.)'H. 

It  is  especially  among  the  compounds  of  carbon  that  the  existence 
of  radicals  conies  into  promiuent  notice.  They,  however,  occur  in 
inorgauic  substances  also.  Thus  the  nitric  acid  molecule  consists  of 
the  radical  NO2,  combined  with  tfie  group  OH. 

Like  the  elements,  the  radicals  possess  differeut  valences,  depend- 
ing upon  the  number  of  unsatisfied  valences  which  they  contain. 
Thus  the  radical  (CH3}  is  nnivaient,  because  three  of  the  four  valences 
of  the  carbon  atom  are  satisfied  by  atoms  of  hydrogen,  leaving  oue 
free  valence.  The  radical  (PO)  of  phosphoric  acid  is  trivalent,  be- 
cause two  of  tiie  five  valences  of  the  phosphorus  atom  are  satisfied  by 
the  two  valences  of  the  bivalent  oxygen  atom,  leaving  thi'ee  free 
valences. 

In  notation  the  radicals  are  usually  enclosed  in  brackets  as  above, 
to  indicate  their  nature.  The  names  of  nnivaient  radicals  terminate 
in  y I  or  m  gen;  thusr    (CHa)^=  methyl;    {CN)^eyauogen. 

The  terras  radhMil  and  frsidne  arc  not  synonymous.  In  speaking 
of  acids  their  radicals  are  obtained  by  the  subtraction  of  a  number  of 
hydroxy  Is  equal  to  the  basicity  of  the  acid.  Thus:  HNO3  —  HO  ^ 
NO3;  H2SO4— 2HO  =  S02;  HaPOi  — 3H0=-P0.  The  rmdue  is 
that  which  remains  after  removal  of  the  basic,  or  replaceable,  hydro- 
gen ,  Thus :  HNO3  —  H  =  XO3 ;  H28O4  —  lit  =  SOi ;  H:iP04  —  H:i  = 
PO4.  (See  Electrolysis,  p.  71.)  The  anhydrids  tsee  p.  Ill  are  de- 
rived from  acids  by  removal  of  water.  Thus :  2HNO3  —  H2O  =  N2O5; 
H8S04  -"  H2O  =  SO3;  2H:iP04  —  3H2O  --  PAs. 

Composition  and  Constitution. — The  characters  of  a  compound 
depend  not  only  upon  the  kind  and  number  of  its  atoms,  but  also 
upon  the  manner  in  which  they  are  attached  to  each  other.  There 
are,  for  instance,  two  substances,  each  having  the  empirical  formula 
C2H4O21  one  of  which  is  a  strong  acid,  the  other  a  neutral  ester.  As 
the  molecule  of  each  contains  the  same  number  and  kind  of  atoms, 
the  differences  in  their  properties  must  be  due  to  differences  in  the 
manner  in  which  the  atoms  are  linked  together. 

The  composition  of  a  compound  is  the  number  and  kind  of  atoms 
caniained  in  Us  molecuU;  and  is  shown  by  its  empirical  formula > 


CHEMICAL    COMBINATION 


85 


Th^  conxHtuthn  of  a  compound  Ls  (he  UHntber  and  kind  of  atoms 
and  their  rtlations  to  each  other ^  within  its  moltcule;  and  h  sh&iru  hy 
it  a  ruthnnl  formula, 

A  rational  formula  is  one  which  partly  or  completely  indicates  the 
eonstitntioD  of  the  body*  Rational  fonnuht*  are  either  typical  or 
graphic.  In  the  system  of  typical  formulae  all  substances  are  oon- 
fiidered  as  being  so  constituted  that  their  rational  fornmliB  may  be 
referred  to  one  of  three  classes  or  typcs^  or  to  a  combination  of  two 

these  types.  These  three  classes,  being  named  after  the  most 
QOQ  substance  occurring  in  each,  are  expressed  thus: 


Tbe  hjrdroeen 

The  Wiit«r 

Tb«  «miiioiii& 

typ«. 

type. 

lyim. 

1} 

i}o 

H  ] 
H 
H  . 

N 

1:} 

i;}". 

Hal 

N, 

etc., 

etc., 

et< 

it  being  considered  that  the  formula  of  any  substance  of  known  con- 
ititQtJon  can  be  indicated  by  substituting  the  proper  element,  or  radi- 
cal, for  one  or  more  of  the  atoms  of  the  type,  thus: 


I  B  {^  H      N        Ca  / 

H  ] 


(CO)" 


►Nz 


oiie     AleohoL 


Eth^Lamln, 


CftlHnm 
cblorid. 


Sulfurir 
acid. 


Ureii. 


Tjrpical  formula?  are  of  great  service  in  the  classification  of  com- 
pound substances,  as  well  as  to  indicate,  to  a  certain  degree,  their 
fiatnre  and  the  method  of  the  reactions  into  which  they  enter*  Thus 
In  the  case  of  the  two  substances  mentioned  above,  as  both  having  the 
wmpofiition  CJIiOa,  we  find  on  examination  that  one  contains  the 
group  (CHs)',  while  the  other  contains  the  group  (C2H3O)',  The  dif- 
fereuee  in  their  constitution  at  once  becomes  apparent  in  their  typical 

fcmul*e,  %^)'}0  and    ^^■^'^^'}  O,  indicating  diflferences  in  their 

properties,  which  we  find  upon  experiment  to  exist.  The  first  sub* 
*lauce  is  neutral  in  reaction  and  possesses  no  acid  properties;    it 

clofiely  resembles  a  salt  of  an  acid  having  the  formula  ^       h}^-  *^^^ 

««<K>nd  substance,  on  the  other  hand,  has  a  strongly  acid  reaction, 
wd  markedly  acid  properties,  as  indicated  by  the  oxidized  radical  and 
tlif  extra -radical  hydrogen.  It  is  capable  of  forming  salts  by  the 
wbstitutiou  of  an  atom  of  a  univalent,  basylous  element  for  its  single 

r?pl«eeable  atom  of  hydrogen:      '^^^a}  ^' 


86  MANUAL   OF    CHEMISTRY 

Although  typical  formulae  have  been  and  still  are  of  great  service, 
many  cases  arise,  especially  in  treating  of  the  more  complex  organic 
substances,  in  which  they  do  not  sufficiently  indicate  the  relations 
between  the  atoms  which  constitute  the  molecule,  and  thus  fail  to 
convey  a  proper  idea  of  the  nature  of  the  substance.  Considering, 
for  example,  the  ordinary  lactic  acid,  we  find  its  composition  to  be 

CaHcOa,  which,  expressed  typically,  would-be  ^  '  *  jj^  f  ^2,  a  constitu- 
tion supported  by  the  fact  that  the  radical  (C3H4O)''  may  be  obtained 
in  other  compounds,  as  ^  ^  cuf-  '^^^^  constitution,  however,  can- 
not be  the  true  one,  because  in  the  first  place,  lactic  acid  is  not  di- 
basic, but  monobasic;  and  in  the  second  place,  there  is  another  acid, 
called  hydracrylic  acid,  having  an  identical  composition,  yet  differing 
in  its  products  of  decomposition.  These  differences  in  the  properties 
of  the  two  acids  must  be  due  to  a  different  arrangement  of  atoms 
in  their  molecules,  a  view  which  is  supported  by  the  sources  from 
which  they  are  obtained  and  the  nature  of  their  products  of  decom- 
position. 

To  express  the  constitution  of  such  bodies  graphic  formulae  are 
used,  in  which  the  position  of  each  atom  in  relation  to  the  others  is 
set  forth.  The  constitution  of  the  two  lactic  acids  would  be  expressed 
by  graphic  formulae  in  this  way: 

/H  /H 

C--H  C-H 

\H  I \0— H 


/H  and  p/H 

\0-H  Y\H 


or,  CH3  CH2OH 

I  I 

CH.OH  and  CHo 

I  I 

CO.  OH  CO.  OH 

Ordinary  Hydracrylic 

lactic  acid.  acid. 

Graphic  formulae  are  usually  still  further  abbreviated,  bonds  being 
indicated  by  dots;  thus:  CH3.  CHOH.  COOH,  and  CH2OH.  CH2. 
COOH. 

Chemical  Kntrgy — Affinity — Displacement — Stability. —  Chemi- 
cal energy  frequently,  but  less  properly,  spoken  of  as  chemical  force 
or  chemism,  is  that  form  of  energy  by  which  the  atoms  are  held 
together  in  the  molecule,  and  by  which,  under  suitable  physical  con- 


CHEMICAL    ENERGY 


8T 


ditiODS,  the  attachmuuts  and  urrangeioent  of  atoms  are  t^b angled.  It 
may  be  potential,  i.  e.,  latent,  as  in  the  molecules  of  carbon  and  oxy- 
gen, autl  i-apiilile  of  eon  version  into  kinetic,  or  active  energy,  as  in 
the  umDifestatioQ  of  heat  in  their  union  to  form  carbon  dioxid. 

The  atoms  of  different  elements  do  not  exhibit  the  same  tendency 
to  enter  into  combination  with  the  alcHn.*^  <»f  a  driven  eh^inent*  Thns 
chlorin  and  oxygen  readily  eomhiHi*  wiih  Lydrogt^u,  wliile  the  rnetals, 
except  the  alkaline  metals  and  palladiinii,  do  not  do  so  at  at).  Oxygen 
eaters  into  combination  with  all  of  the  other  elements  except  tiiioriu 
and  the  elements  of  the  argon  group,  while  the  last-named  form  no 
compound  with  any  other  element.  Snch  differences  in  lendrncy  to 
union  were  known  to  the  alchemists,  who  referred  to  them  as  differ- 
ences  in  the  degree  of  affection  or  antagonism  of  the  substances 
toward  eneh  other,  and,  as  no  cause  is  as  yet  known  for  the  varia- 
tions, beyond  the  surmise  that  they  may  be  due  to  differences  in 
electrical  or  other  attraetioUi  they  are  still  referred  to  by  saying  that 
the  elements  have  strong  or  weak  affinity. 

Frequently  when  an  element  is  bruuglit  in  contact  with  a  com* 
pound  the  fi^e  element  displaces  one  of  those  contained  in  the  com* 
I»omid;  as  when  chlorin  is  in  eon  tact  with  sodium  lodid,  sodium 
<;hlorid  is  formed  and  iodin  liberated:  2NaI  +  CI2  =  2NaCI  +  I2. 
This  ig  ascribed  to  the  greater  affinity  of  chlorin  {p,  99). 

There  are  also  differences  in  the  degree  of  permanence  of  com- 
pounds under  the  inflnenee  of  slight  variations  in  physical  condi- 
tious.  Thus,  of  the  two  compounds  of  hydrogen  and  oxygen,  one, 
^ater,  is  dissociated  only  (p.  90)  at  very  iiigli  temperatures,  while 
the  other,  hydrogen  peroxid,  is  decon)]>^>sed  by  very  slight  heating. 
Tbejte  variations  are  referred  to  by  s:i\  ing  that  certain  compounds 
Hre  stable,  others  labile,  or  unstable*  The  stability  of  the  compound 
*Hends  upon  the  affinities,  the  proportions,  and  the  arrangement  of 
the  atoms  in  the  mole^'ule  (p,  98). 

Chemical  Equilibrium.^Wheu  two  or  more  substances  are 
hrought  together,  their  association  constitntes  a  chemical  system* 
*^  tliis  system  an  action  may  be  set  up,  which  will  proceed  to  a 
^'trtain  point,  and  then  eease.     The  system   is  then  said  to  be  in 

Pwmical  equilibrium.  As  in  meehanical,  so  in  chemical  equilibrium 
wJ« condition  of  rest  does  not  imply  that  no  force  is  in  action,  but 
*^4t  the  forces  acting  neutralize  each  other  in  such  manner  that 
^li^ir  algebraic  sum  is  zero;   the  condition   is  one  of  dynamic  eqni- 

As  the  "physical**  conditions  of  concentration,  pressure  and 
^^mp^rntnre  exert  great  influence  upon  the  occurrence  and  extent  of 
<^hr»mi(^al  changes,  these  must  be  taken  into  account  along  with 
ifflaity;  and  the  ^* physical*'  phenomena  of  solution,  and  changes  of 


88 


MANUAL    OF    CHEMISTRY 


state  of  aggregation  must  also  be  considered  along  with  changes  of 
composition  in  the  consideration  of  chemical  equilibrium.  ^ 

Equilibrium  in  a  system  all  parts  of  which  have  the  same  physical^' 
properties  and  the  same  chemical  composition  (p,  49),  as  in  a  solution 
or  in  a  mLxture  of  liquids  or  of  gases,  is  distinguished  as  homo- 
geneous equilibrium ;  while  hcterogeocous  equilibriuin  occurs  in  a 
system  the  parts  of  which  are  separated  by  bounding  surfaces,  as 
when  solids  and  liquids,  or  immiscible  liquids  are  in  contact. 

Distinction  must  also  be  made  between  real  and  apparent  equilib- 
rium. In  a  state  of  real  equilibrium  there  is  no  change  of  relations, 
liowever  slight  or  however  slow,  so  long  as  the  conditions  of  con- 
eeotration,  pressure  and  temperature  remain  constant,  and  changes 
which  are  caused  by  variations  in  these  conditions  take  place  regularly 
and  continuously.  Thus,  in  a  system  composed  of  a  solution  in 
contact  with  excess  of  the  solute,  variations  in  the  proportions  of  the 
solute  in  the  solution  take  place  regularly  with  variations  of  tempera- 
ture. Moreover,  in  this  case  the  same  condition  of  equilibrium  ifi_ 
reached,  whether  it  be  approached  from  one  side  or  from  the  other.B 
Thus,  a  solution  at  a  giveu  temperature  contains  the  same  proportion 
of  solute,  whether  it  be  obtained  by  addition  to  an  unsaturated  solu- 
tion, or  by  deposition  from  a  supersaturated  solution.  In  a  condition  of 
apparent  equilibrium  it  is  probable  that  change  is  contiuuousiy  taking 
place,  although  frequently  with  such  extreme  slowness  that  it  escapes 
observation,  even  at  constant  concentration,  temperature  and  pres- 
sure. Such  changes  as  are  caused  by  variations  in  these  conditions 
in  apparent  equilibrium  may,  within  certain  limits,  occur  with  regu- 
larity, but  beyond  these  limits  a  sudden  and  more  or  less  violent 
change  takes  place,  after  which  the  relations  which  existed  previously 
are  not  restored  b}^  a  return  to  the  original  conditions.  Thus,  in  a 
system  consisting  of  water  and  a  mixture  of  hydrogen  and  oxygen > 
with  moderate  variation  of  temperature  and  pressure  there  are  slight 
and  regular  variations  in  the  amount  of  oxygen  dissolved  in  the 
water,  but  at  a  certain  elevation  of  temperature  a  sudden  combination 
of  the  gases  to  form  water  takes  place  and,  on  cooling,  the  gases 
do  not  reappear.  H 

The  condition  of  chemical  equilibrium  is  one  corresponding  to 
that  of  stable  mechanical  equilibrium,  i.  e,,  a  condition  to  which  the 
system  tends  to  return  when  the  equilibrium  is  disturbed.  This 
general  proposition  is  known  as  the  theorem  of  Le  Chatelier,  and  is 
thus  expressed  by  Ostwaldr  //  n  s*fskm  in  equilibrium  is  subjected 
to  a  eonstruini  by  which  the  equilibrium  is  shifted,  a  reaction  takes 
place  which  opposes  the  constraint ^  t\  e.,  one  by  which  its  effect  is 
partly  destroyed. 

Thus,  when  the  temperature  of  a  system  in  equilibrium  is  raised^ 


CHEMICAL    ENERGY 


that  reaction  takes  place  which  is  aecompanied  by  absorption  of  heat 
(p»  97).  and,  conversely,  when  the  temperature  is  lowered  that 
reaction  occurs  which  is  accompanied  by  an  evolntion  of  heat.  This 
is  known  as  Van't  Hoff's  la\^  of  movable  equilibrium. 

When  the  pressure  upon  a  system  in  equilibrium  is  increased »  an 
action  takes  place  which  is  accompanied  by  diminution  in  volume, 
and  when  the  pressure  is  diminished,  an  action  occurs  which  is 
attended  with  an  increase  in  volume. 

VV^hen  the  volume  of  a  system  in  equilibrium  is  diminished,  the 
{iressure  is  increased,  and  an  action  occurs  tending  to  relieve  the 
pressure,  and  when  the  volume  is  increased  the  pressure  is  diminished, 
and  an  action  takes  place  tending  to  raise  the  pressure. 

Reversible  Reactions.— Many  reactions  are  known  to  occur   in 

which  displacements  may  be  bi-ought  about  in  opposite  directions. 

Clearly  in  these  some  influence  other  than  affinity  must  determine  in 

which  direction  the  reaction  will  occur.    8uch  are  called  reversible 

reactions,  or  reversed  actions.    Thus,  if  iron  be  heated  in  an  atmos- 

l>here  of  vapor  of  water,  the  iron  displaces  the  hydrogen  of  the  water, 

which  is  liberated,  and  combines  with  the  oxygen  to  form  oxid  of 

irou  (p.  105).    If,  on  the  other  hand,  oxid   of  iron  be  heated   in  an 

atmosphere  of  hydrogen,  the  hydrogen  displaces  the  iron,  which  is 

Uberateil,  and  combines  with  the  oxygen  to  form  w*ater  (p.  198). 

The  reaction  may  take  place,  therefore,  according  to  the  following: 

^nation,  read  either  from  left  to  right,  or  from  right  to  left: 


Ifon* 


-h 


8H3O 

Water. 


SPeoO* 


Trifenie  t*troxid. 


8H2 
HydroffOD. 


If  we  start  with  pure  iron  and  vapor  of  water  the  reaction  wiil 
prowed  according  to  the  equation  read  from  left  to  right  until  the 
proportion  of  hydrogen  and  water  vapor  present  has  reached  a  certain 
ratio,  when  the  action  will  cease,  and  the  system  will  be  in  equilib- 
rium. Starting  with  pure  oxid  of  iron  and  hydrogen,  on  the  other 
^**od,  the  reaction  will  proceed  according  to  the  equation  read  from 
•"igtit  to  left,  and  will  cease  when  the  ratio  of  hydrogen  to  water 
^'^m  will  have  acquired  the  same  value  as  that  reached  in  the  first 
instaoct*.  As  the  condition  of  equilibrium  reached  in  the  two  cases  is 
^»^  same  when  prodoeed  by  proceeding  in  either  direction,  it  is  one  of 
^^  ^qailibrium,  and,  as  might  be  expected,  if  a  mixture  of  iron  and 
oxid  of  iron  be  heated  in  an  atmosphere  composed  of  hydrogen  and 
^*^kT  vapor  in  the  proportion  reached  in  either  of  the  two  former 
f^^ntrtious,  no  change  whatever  will  occur. 

Ill  any  of  the  above  experiments,  mixtures  of  iron  and  oxid  of  iron 
i^  Hiiy  proportions  may  be  used  without  influencing  the  results  in  the 
•iishtest.    The  direction  which  the  reaction  will  take  to  reach  the 


90 


BIANUAL    OF    CHEMISTBY 


3UtH 


eonditioQ  of  equilibrium  is,  therefore,  uut  determined  by  the  relative 
amounts  of  the  solid  substances  present,  but  by  the  ratio  of  the  two 
gaseous  constituents  of  the  system.  Moreover,  for  a  given  ratio  of 
hydro^^en  to  water  vapor,  the  rea<5tioii  wit!  always  proceed,  if  they  be 
not  in  the  ratio  of  eqoilibrium,  iu  the  same  direction,  w^jatever  may 
be  the  weight  or  mass  of  either  the  gas  or  the  vapor  present.  The 
dire<:*tion  of  the  reaction  is,  therefore,  not  determined  by  the  mam  of 
eitlier  the  hydrogen  or  water  vapor  present,  but  by  its  nmcfufratiotK^t 
And  this  ex  phi  ins  wiiy  a  solid,  insoluble  substance  lias  no  influence™ 
upon  the  direction  which  a  reversible  I'eaclion  will  take.  As  solids 
vary  in  volume  only  slightly  with  variations  of  temperature  and 
pressure,  and  as,  when  mixed,  they  form  only  nieehauical  mixtures 
(p,  47),  which  are  heterogeneous,  they  do  not  vary  in  concentration;  ■ 
but  gases  and  liquids,  which  form  homogeneous,  physical  mixtures 
(p,  49),  and  whose  volumes  are  notably  modified  by  variations  in 
pressure  and  temperature,  also  vary  correspondingly  in  concentra- 
tion, not  only  under  the  influence  of  those  "physical"  conditions,  butj 
also  according  to  the  proportions  in  which  the3^  are  mixed. 

Dissociation. — Vapor  of  water  when  heated  at  10013*^  begins 
decompose  into  its  constituent  elements,  and  the  proportion  of  water^ 
decomposed  increases  with  rise  of  temperature  in  snch  manner  that 
at  2500'^  degrees  half  of  the  water  present  is  split  into  a  mixture  of 
hydrogen  and  oxygen,  Tliis  phenomenon,  w^hich  is  referred  to  as 
dissociation,  is  not  peculiar  to  water  vapor,  and  many  other  sub-^| 
stances  are  similarly  decomposed  at  more  or  less  elevated  tempera- 
tures, the  extent  of  the  decomposition  increasing  with  elevation  of 
temperature  and  with  diminution  of  pressure.  The  reaction  is  also  a 
reversible  one;  in  the  case  of  water  2H2O  <  ^  2H2H-02,  and,  on 
diminution  of  temperature  or  increase  of  pressure,  reeombi nation 
occurs  iu  the  sense  of  the  equation  read  from  right  to  left.  Neither 
the  decomposition  nor  the  recombination  occurs  suddenly,  _— 

By  dissociation  the  number  of  molecules  in  unit  volume  at  con*H 
staut  volume  is  increased,  therefore;  at  constant  pressure  the  volume 
increases  and  the  density  diminishes.    The  extent  of  dissociation  may 
be  computed  from  the  diminution  of  density  at  constant  pressure,        ■ 

Dissociation  is  in  accordance  with  the  kinetic  theory  of  gases 
{p.  25).  The  velocity  of  motion  of  the  molecules  increases  with  rise 
of  temperature^  and  the  same  cause  produces  increase  of  velocity  offl 
atomic  motion  within  the  molecule,  until  what  may  be  termed  the 
centrifugal  energy  of  the  atoms  exceeds  the  chemical  force  of  affinity, 
and  the  molecule  is  disrupted.  But  as  the  velocity  of  molecular  and 
atomic  motion  of  all  the  molecules  present  is  not  the  same,  some  ^ 
e0Qape  decomposition.  ^ 

Velocity  of  Reaction^— Under  given  conditions  of  concentration, 


VELOCITY    OF    REACTION 


91 


terop^rature  and  pressure,  every  chemical  reaction  requires  the  lapse 
of  a  definite  time  for  its  completion.  UsunlJy  this  is  shorty  but  some- 
limes,  as  in  atmospheric  oxidations,  quite  exteudt;d,  and  sometimes,  as 
in  conditions  of  appareiit  eqnilibriurii,  too  long  fur  measurcTnent. 

Thf  time  requhed  for  a  fjiveti  chemical  naclioH   is  ahvtrifn  abbrf- 
riatrd    by   itwrease  of   temperatHre.      Therefore,    heat    is  applied  to 
€x;>edite  a  reaction;    and  to  calm  a  too  turbulent  reaction  it  is  con* 
ducted   with   artificial    cooling.     Although  it  is  pr<j}>able  that  in   a 
uysteni  composed  of  two  or  more  eoustitueuts  capable  of  reacting 
with  each  other,  such  reaction  occurs  with  varying  degrees  of  slow- 
ness at  all    temperatures    consistent    with    the    njintitenanee    of   the 
gaseouH  or  liquid  state  of  aggregation,  it  frequently  htippt^jis  that  it 
takes    place    with   sensible   rapidity  only  within    certain    ranges    of 
temperaint^.    This  is  true  of  many  combinations  and  decompositions, 
au<!,  notably,  of  the  chemical  proaesses  occurring  in  living  organisms. 
In  H  system  composed  of  a  large  mass  of  material,  tlie  ccmiponents  of 
which    unit^    with    liberation    of    heat,    the    condition    of    apparent 
equilibrium  is  violently  disturln^d  throughout  the  mass  by  the  appli- 
cation of  sufficient  heat  to  start  the  reaction  at  a  single  point   in  the 
mixture;    as  when  a  mixture  of  hydrogen  and  oxygen  is  "exploded" 
by  the  passage  of  the  electric  spark, 

D**terminations  of  reaction  velocity  have  been  made  principally 
witli  organic  sulistances,  in  reactions  which  take  place  with  sufficient 
ftlowness,  and  where  the  necessary  eondilious  can  be  fulfilled.  Clearly, 
from  what  precedes,  such  determinations  must  be  made  isotherm  ally, 
i.  e,>  at  constant  teuiperatnre,  and  the  reactions  selected  mnsi  be  irre- 
vemble,  or  nearly  so. 

Prom  experiments  with  the  inversion  of  cane-sugar  (p,  318).  a 
feai'tioM  which  is  irreversible,  and  progresses  aci:ordi ug  to  tlje  equa- 
tion? tTioHyiOn  +  H^jO^^CflllriOfi  +  CoHioOfl,  and  the  slow  progress  of 
^hich  can  be  measured  with  the  polariscope,  it  has  been  deterndned 
Ibat  n  cofistanf  fracfhn  of  thf^  HuMtancf  is  decomposed  during  each 
«»e7  rt/  tipne,  and  that  the  velocity  of  reaction  is  proportionate  to  the 
<f>i^Mtt  ration  of  the  sub  nt  a  nee, 

ftom  this  and  other  mvestigatidns  it  has  been  determined  that 
fOrevi*ry  reaction,  at  a  given  temperature  and  concentration,  there  is 
*  '^♦'fimte  velocity  constant,  which  is  designated  by  the  symbol  k. 
Tlif  value  of  k  may  be  defined  as  the  number  of  mols  of  a  substance 
which  lire  produced  (or  decomposed)  in  one  minute  by  the  interaction 
^'  (or  with  production  of)  one  luol  each  of  the  constituents  (or 
PMnct^),  in  a  volume  of  one  titer,  in  an  apparatus  so  coustructed  as 
to  be  isothermal,  and  so  that  the  substance  or  snbstanees  undergoing 
Action  may  be  maintained  at  constant  concentration,  and  that  the 
pwidncts  of  the  reaction  may  be  constantly  removed. 


92 


MANUAL    OP    CHEMISTRY 


Mass  Action *^The  example  of  a  reversible  reaction  given  abov^ 
was  one  in  a  beterog^ent^ous  system,  couipo^ed  of  solids  and  gases. 
As  an  example  of  a  reaction  of  this  kind  oeenrring  in  a  bomogeoeou^ 
system »  a  solntion,  we  may  consider  that  represented  by  the  following 
equation  i 


CB3.C00H 

Aoelie  acid. 


4- 


Etbylie  alcohol. 


CH3.COO(C;Hfi) 

Ethyl  «vetAte. 


H.O. 

Water. 


1 


If  we  start  with  ethyl  alcohol  and  acetic  acid,  the  reaction  will 
proceed  according  to  the  equation,  read  from  left  to  right;  but  if  we^  J 
start  with  ethyl  acetate  and  water  it  will  proceed  from  right  to  left.  ™ 
In  neither  ease,  however,  will  it  be  complete.  If  one  jnol  each  of  the 
reacting  substances  have  been  used,  real  equilibrium  will  have  been 
established  and  the  reaction  will  have  ceased  when  the  composition  of 
the  mixture  has  become:  %  mol  acetic  acid,  %  mol  alcohol,  %  moi 
ethyl  acetate  and  %  mol  water.  This  statement  is  not  to  be  taken  as 
meaning  that  when  this  relation  is  attained  no  further  action  occurs, 
but  that  the  changes  in  one  direction  have  become  equal  in  unit  time  ta 
those  ill  the  opposite  direction;  the  equilibrium  being  dynamic,  not 
static. 

If  we  designate  any  two  or  more  substances  bearing  similar 
relations  to  each  other  to  those  between  acetic  acid  and  alcohol  by 
A+B  +  .  .  ,  ,  and  any  two  or  more  other  substances,  bearing  the 
same  relations  to  A+B+,  .  .  as  those  which  exist  betweeu  acetic  H 
ai'id  and  alcohol  cm  the  one  hand,  and  ethyl  acetate  and  water  on  the-  ™ 
other  by  X+Y+.  .  .  ,  and  supposing  these  to  he  contained 
in  a  homogeneous  system,  then  the  above  equation  may  be  expressed 
generally : 

A+B4-.   .    .    t:=-^    X+Y+.    .   . 


Invoking  now  the  kinetic  theory  of  gases  as  applied  to  solutionSr 
(pp.  25,  70):  that  the  particles  of  A+B+.  .  .  and  X+Y.  . 
whether  molecules  or  ions,  are  in  constant  motion ,  the  activity  of 
which  is  proportionate  to  the  absolute  teiuperatore^  at  a  given 
temperature  the  collisions  betw^een  the  particles  A+B+,  .  .  ,  and 
between  X  +  Y+.  .  .  will  be  the  more  numerons  tlie  greater  the 
numl>er  of  particles  present  in  unit  space,  i,  c,  the  greater  the  con- 
centration. And  assuming  further  that  collisions  between  such 
particles  are  the  prerequisite  of  their  reaction  with  each  other,  it 
follows  tliat  the  velocity  of  the  reaction  between  A+B+.  .  .  is* 
proportionate  to  the  product  of  their  concentrations,  and  similarly 
with  regard  to  the  velocity  of  the  reaction  between  X+Y  +  *  .  - 
Then  if  we  express  the  concentration,  in  mols  in  a  liter,  of  A,  B,  X^ 
Y   by   Ca,   Cb,   Cx   and   Cy,   the    velocity   of    reaction,    v,    betweea 


1 


I 


MASS    ACTION 


93 


A+B+.  .  .  will  be  v^kCaCb  .  ,  .  ,  in  which  k  is  the  velocity 
u^t^nt  for  the  reaction  and  the  temperature;  and  the  velocity,  v^ 
W  the  reaction  between  X+Y+.  .  .  will  be  v'^k'CxCy  .  .  .  ,  in 
which  k'  is  the  velocity  constant  for  this  reaction  and  the  same 
temperature.  Neither  the  value  of  v,  nor  that  of  v^  is  observable  fn 
&ach  a  system,  but  the  difference  between  them  is,  if  any  reaction 
occur.  If  no  action  takes  place,  then  v  — v'^^0.  or  v^— v^0»  and 
then  kCaCb   .    .    ,  =k'CxC,. 

This  is  equivalent  to  the  statement  that:  Whrn  hi  ft  homogeneous 
system  composed  of  reacting  stihsianrfu  and  their  protlnrt^s  of  reaction 
at  (t  tjiven  temperature,  the  prod  net  of  the  concentrations  of  the  reacting 
siiKKtances  and  (he  velocity  constant  of  their  react ioti  is  equal  to  the 
aduct  of  the  conrenfrations  of  the  products  of  reaction  and  the  Vf- 
Uciiy  constant  of  their  react wn^  the  tiystem  is  in  real  equilibrium, 
m^d  no  reaction  occurs. 

But  if  any  reaction  do  occur,  its  velocity,  V,  will  be  the  difference 
between  the  velocities  of  any  two  possible  reversible  reactions,  either 
V=v— v'=kaCb  .  .  — k'C\CV.  .  ,or  V=v'— v  =  k'CxCy  .  .  — 
VC»Ch  •  .  .  Which  is  equivalent  to  the  statement  that:  \Mien  the 
tm  prfHhtcts  above  referred  to  are  not  equal,  a  reaction  occurs,  which 
proeffds  towards  and  to  the  estahUshmeni  of  such  equality  and  equi- 
lihrkm* 

The  two  italicized  statements  constitute  the  law  of  Guldberg:  and 
Wimge,  or  the  law  of  mass  action,  the  latter  rather  a  misnomer,  as 
tbe  direction  of  the  action  does  not  depend  upon  the  relative  masses, 
hu  upon  the  relative  concentrations. 

Heterogeneous  Equilibrium  —  Phase  Rule.— A  heterogeneous 
system  consists  of  two  or  more  parts,  each  of  which  is  homogeneous 
*Q  itself  but  different,  physically  or  chemically,  from  the  other  or 
others,  the  several  parts  being  separated  from  each  other  by  bound- 
ing surfaces.  8uch  parts  are  called  phases  of  the  system,  represented 
^*y  the  symbol  P.  As  gases  and  vapors  mix  with  each  other  in  any 
I>n)portions  and  constitute  a  homogeneons  mixture,  there  can  be  but 
**oe  guseous  phase  in  any  system;  and  as  a  solution,  whatever  the 
Dumbin*  and  amounts  of  the  solutes,  is  also  in  itself  homogeneous, 
«uy  single  liquid^  either  pure  or  acting  as  a  solvent,  can  constitute 
^it  one  phai^e  of  a  system  in  equilibrium.  But  of  immiscible  liquids 
^^i  solids  a  system  may  contain  any  number  of  pliases.  On  the 
^'"^t"  hand,  the  same  substance  may  constitute  more  than  one  phase 
*^'*R,vstem.  Thus  ice,  water  and  vapor  of  water,  being  spaeially  dis- 
tinct from  each  other,  wdien  together  constitute  a  three-phase  system. 
The  conditions  of  equilibrium  in  a  system  such  as  that  last  men- 
tioned are  three:  concentration  (volume),  temperature  and  pressure. 
We  have  seen  (p.  57)  that  equilibrium  in  a  gas  depends  upon  these 


94  MANUAL   OF    CHEMISTRY 

conditions,  for  by  transposition  of  the  equation  vp  =  RT  we  have 

Y==R»  in  which  R  is  a  constant.    It  has  also  been  shown  that  the 

volumes  of  liquids  and  solids  are  modified  by  variations  in  tempera- 
ture and  pressure  in  the  same  manner  as  gases,  although  to  a  much 
less  extent;  therefore  equilibrium  in  these  depends  upon  the  same 
conditions  as  that  in  gases.  Now  in  the  above  equation  the  values  of 
any  two  of  the  three  variables  v,  p,  and  T  may  be  fixed  arbitrarily, 
but  when  they  have  been  chosen  the  third  is  thereby  made  definite. 
This  is  expressed  by  saying  that  a  one-phase  system,  a  gas,  a  liquid, 
or  a  solid,  possesses  two  degrees  of  freedom,  represented  by  the 
symbol  P.  The  degrees  of  freedom  of  a  system  are  the  number  of  the 
variants,  concentration,  pressure  and  temperature  which  must  be  arbi- 
trarily fixed  in  order  that  the  condition  of  the  system  may  be  defined. 
They  are  also  expressed  by  saying  that  the  system  is  invariant,  uni- 
variant,  bivariant,  etc.,  according  to  their  number.  Clearly,  the 
conditions  of  equilibrium  in  a  one -phase  system  are  those  of  homo- 
geneous equilibrium.  Heterogeneous  equilibrium  may  exist  only  in 
systems  containing  two  or  more  phases. 

We  have  also  seen  that  in  a  two -phase  system,  such  as  that  made 
up  of  a  liquid  and  its  saturated  vapor,  only  one  of  the  three  variables 
can  be  chosen  arbitrarily,  for  (p.  31)  if  the  temperature  be  arbitrarily 
fixed,  any  variation  of  the  volume  will  be  attended  by  evaporation  or 
condensation,  i.  e.,  an  action  tending  to  restore  the  disturbed  equilib- 
rium, in  such  manner  that  the  pressure  remains  constant,  and  a 
similar  action  will  maintain  a  constant  volume  if  the  pressure  be 
changed.  Therefore  a  system  composed  of  two  phases  of  the  same 
chemical  substance  has  only  one  degree  of  freedom,  and  when  that 
is  chosen  the  other  two  become  definite.  It  has  also  been  shown  that 
increase  of  pressure  slightly  diminishes  the  volume  of  liquid  water, 
and  at  the  same  time  correspondingly  lowers  the  freezing  point. 
Therefore  the  system  ice: water  also  has  but  one  degree  of  freedom. 
It  can  be  stated  in  general  terms  that  the  number  of  degrees  of  freedom 
diminishes  with  the  increase  of  the  number  of  phases  present.  And  if 
this  be  true,  the  addition  of  a  third  phase  to  the  last  system  should 
produce  one  having  no  degree  of  freedom,  and  the  system  ice  .water: 
vapor  can  only  exist  in  equilibrium  at  one  definite  volume,  pressure 
and  temperature.  This  is  found  to  be  the  case  at  a  temperature  of 
0.0076°C.  and  a  pressure  of  4.6  nini.  of  mercury.  This  invariable 
point  is  the  only  one  at  which  the  three  phases  ice: water: vapor  can 
exist  in  stable  equilibrium  together,  and  it  is  called  the  triple  point 
of  water.  If  the  temperature  be  raised  the  ice  disappears,  and  if  it  be 
lowered  the  water  disappears.  If  the  pressure  be  raised  the  vapor 
disappears,  and  if  it  be  lowered  the  water  disappears.    Every  sub- 


MASS    ACTION 


95 


I  n1 


has  its  triple  point,  near  to,  but  not  at,  its  fusing  point.  Bat 
application  of  heat  to  the  three-phase  system  ice: water:  vapor  at 
its  triple  point,  or  the  withdrawal  of  heat  therefrom,  does  not  cause 
immediate  conversion  into  a  two -phase  system.  If  heat  be  added 
constant  volome  it  causes  a  portion  of  the  ice  to  melt,  i.  e.,  S  —  >  L 
(solid  to  liquid),  thereby  becoming  latent,  without  rise  of  tempera- 
ture. But  as  the  ice  melts  it  contracts  in  volume,  causing  diminution 
of  pressure,  which  brings  about  the  passage  of  some  ice  to  the  form 
of  vapor,  8 — >  V,  so  that  the  sum  of  the  effect  of  addition  of  heat 
is  ^ — >L+V,  and  the  abstraction  of  heat  causes  the  reverse  change, 
L+V^^>S.  Therefore,  at  temperatures  above  the  triple  point  the 
solid  cannot  exist,  and  at  temperatures  below  that  point  either  system 
S— L  or  S — V  may  exist  at  first,  and  which  of  the  two  will  remain 
n  abstraction  of  heat  at  constant  volume  will  depend  upon  the  rel- 
ative amounts  of  L  and  V  present.  With  suVjstances  which  expand 
on  mdtiug,  which  is  the  more  usual  case,  the  conditions  are  some- 
what different.  The  addition  of  heat  at  the  triple  point  causes  the 
solid  to  melt,  as  in  the  former  case,  S  — >  L,  but  the  solid  expanding 
on  fusion  causes  increase  of  pressure  and  condensation  of  vapor,  i.  e.^ 
V — >L,  so  that  the  sum  of  the  first  action  of  heat  is  S  +  V — >L; 
t&d  whether  the  system  finally  resulting  will  be  S  +  L  or  V+L 
depends  upon  the  relative  amounts  of  H  and  V  present.  In  so  far  the 
condition  of  equilibrium  is  influenced  by  the  relative  masses  of  the 
phases  present,  but  it  is  not  otherwise  influenced  by  either  their  abso- 
IqUj  or  relative  masses.    The  witlidrawal  of  lieat  causes  the  opposite 

If  we  start  with  the  two-phase  system  water:  vapor,  and  diminish 
the  t*f!iiperature,  the  latter  will  fall  notably  below  that  of  the  triple 
point,  without  the  formation  of  the  third  phase,  iee.  This  condition 
of  ii01>erf usion  (p.  29)  is  an  instance  of  suspended  tratisformation, 
^hich  frequently  occurs,  the  system  being  then  in  a  condition  of 
f<inilibriura  which  is  designated  as  metastable.  A  new  phase  in  not 
[fintml  immediately  tr/ww  the  conditioHS  of  fhe  sifntfrn  heeomf  such  that 
*i»m$lence  is  possible,  except  it  be  already  present.  Thus  the  m eta - 
fiiAhJH  condition  of  su perfused  water  is  immediately  converted  into  a 
eondifion  of  stable  equilibrium,  with  rise  of  temperature  and  forma- 
n  of  ice,  by  contact  with  ice. 

In  the  above  we  have  considered  equilibrium  in  a  system  all  of 
1086  phases  have  the  same  composition.  When  the  several  phases 
differ  in  composition,  the  question  becomes  morr  (♦nmplex.  Taking  as 
fin  example  the  reversible  reaction  represented  by  the  equation: 


CaCOs  <= 

Cftldtmi  ctkrboiuite. 


CftO 


CO, 
CurboQ  dioxid. 


MANUAL   OP   CHEMISTRY 

if  we  start  with  CaCOa  at  the  ordinary  temperatnre  and  pressure  no 
reaetion  occurs,  but  on  raising  the  temperature  a  reaction  takes 
place  according^  to  the  equation  read  frotn  left  to  right  untile  at  a 
definite  temperature  tx,  and  a  definite  pressure  px»the  ratio  between 
C-aOOa  and  CaO+COs  has  become  fixed.  Or,  if  we  start  from 
CaO+COs,  then  CaCOs  will  be  formed,  in  the  sense  from  right  tofl 
left  of  the  equation,  until  at  tx  and  px  the  same  ratio  between  CaCOs 
and  Ca+C02  is  attained  as  in  the  first  instance.  The  eqinlibriuni  is 
therefore  real.  ^^ 

Let  ns  suppose  that  the  rea<^tion  has  proceeded  in  either  sense  to 
tx  and  px  in  a  closed  vessel,  wliose  vol n me  can  be  changed  at  will. 
The  system  will  then  be  one  of  three  phases,  two  solid  and  one 
gaseous.  If  now,  maintain ing^  tx  constau^  the  volume  of  the  vessel 
be  increased,  a  further  change  from  left  to  right  will  occur,  to  such 
extent  that  px  also  remains  constant,  and  if  the  volume  be  dimin- 
ished at  tx,  a  reaction  occurs  from  right  to  left,  also  to  such  extent 
that  px  remains  constant.  As  tx  and  px  maintain  their  constant 
ratio  for  any  arbitrarily  chosen  value  of  volume,  the  system  is  one  of 
one  degree  of  freedom,  wherein  it  differs  from  the  other  three-phase 
system  of  ice  iwat^er: vapor,  which  is  invariant.  ^ 

The  condition  of  effiulihrufm  depends  not  onlij  upon  the  numbfr  of 
phases  prfseiif,  hni  uUo  upon  the  nnmbfr  of  components.  The  com- 
ponents of  a  system  are  not  all  of  the  chemical  species  present,H, 
whether  elements  or  compounds,  but  only  such  of  these  as  can 
undergo  independent  variation  of  coucentratiou  iu  the  several  phases. 
Therefore,  the  elements  constituting  a  compound  are  never  considered 
as  components  of  a  system.  In  systems  containing  more  than  one 
component  ffiere  is  a  certain  degree  of  liberty  in  the  selection  of 
what  substances  shall  be  considered  as  components^  but  it  is  not  the 
nuiure,  but  the  number  of  components  which  is  of  iniportanee,,  and 
this  remains  constant  whatever  the  method  of  selection.  The  simplest 
method  of  determining  the  number  of  components  is  that  suggested 
by  Ostwald,  which  presupposes  that  the  chemical  composition  of  each 
phase  present  is  known:  fl 

If  each  of  all  of  the  phases  present,  taken  as  a  whole,  has  one 
and  the  same  composition,  the  system  contains  one  component  or  is 
of  the  first  order.  E.g.,  ice:  water :  vapor  of  water.  If  two  phases  must 
be  mixed  iu  suitable  proportion,  or  combined,  to  obtain  the  eomposi- 
tiou  of  a  third  phase,  the  system  contains  two  components,  or  is  of 
the  second  order.  E.g.,  CaCO:^:0aO:<JO2,  in  which  CaO+C02=CaC03. 
And  if  three  phases  or  constituents  are  necessary  to  obtain  the  com- 
position of  another  phase,  the  system  contains  three  componeuts,  or 
is  of  the  third  order.  Such  a  system  of  two  phases  and  three  com- 
ponents is  formed  by  shaking  together  chloroform  (CHCI3),  water 


THEEMOCHEMIKTRY 


97 


(H3O)  and  acetic  acid  (C2H4O2).  As  CHCI3  and  H2O  are  "immis- 
cible," but  each  soluble  in  the  other,  on  agitation  and  separation 
thejform  two  layers,  the  upper  99.2  per  cent  H2O  and  0.8  per  cent 
CHCb,  and  the  lower  99  per  cent  CHCI3  and  1  per  cent  H-O.  If 
loetic  aeid,  which  is  miscible  in  all  proportions  with  both  H2O  and 
CHCI3,  be  agitated  with  the  above  system,  it  is  partitioned  between  the 
two  layers*  forming  after  separation,  two  liquid  phases  each  con- 
tmlng  HiO,  CHCla  and  C2n402  in  different  proportions. 

Again  comparing  the  two  three-phase  systems,  ice: water: vapor 
and  CaCOsrCaOiCOs,  we  have  seen  that  the  latter  has  one  degree  of 
freedom  more  than  the  former,  and  it  also  contains  one  more  com- 
ponent.  The  numher  of  degrees  of  freedmn  hi  a  sijstem  iner eases  with 
t\i  number  of  components. 

These  relations  are  concisely  and  definitely  expressed  in  the 
Phase  Rule  of  Gibbs: 


FH-F^C+2 


or 


p  =  C4^2  — P 


ia  which  P  denotes  the  number  of  phases,  F  the  number  of  degrees 
of  freedom,  and  C  the  number  of  components.  Thus,  in  the  system, 
ice; water  P^=2,  C^l/.  F  =  l;  in  that,  ice: water: vapor,  P— 3, 
C=l.<,  F=0?  in  that  CaCO^rCaOiCO.,  P=3,  C=2/.  F=l;  and 
iath«tCHCh:H20:C2H40i,  P--2,  C--3a  F=3. 

When  the  number  of  components  reaehes  four  there  may  be  four 
degrees  of  freedom,  as  in  the  system  P=2,  C^4/.  F=4.  This 
MOttsitates  a  greater  number  of  variables  than  the  three  above  men- 
tioned. These  independent  variables  are  found  in  varying  couceutra- 
tioni  of  the  several  components,  or  in  the  partial  pressures  of  gaseous 
wmjvonents. 

Thcf mo-chemistry. — Thermodynamics  is  that  branch  of  science 
which  treats  of  the  relations  of  heat  to  nieehanical  energy;  thermo- 
chemistry has  to  do  with  the  closely  allied  relations  between  heat 
iod  chemical  energy.  The  two  fundamental  laws  of  thermodynamics 
ire  aljsio  applicable  in  thermo- chemistry: 

1.  Tlie  apparent  loss  of  enerfjy  in  a  closed  system  is  always  accom- 
pQnitd  b^  (he  generation  of  an  amount  of  heat  iijhich  is  exactly  equiirn- 
imt  iherfto, 

2.  Heat  rannoi  pass  of  itself  from  a  cold  to  a  hot  body^  nor  can 
it  be  to  transferred  mthmd  the  expendifure  of  an  equivalent  amount 
iff  ^ork. 

Chemical  reactions,  including  "physieal"  solution,  are  always 
attended  with  a  transformation  of  energy  from  potential  to  kinetic, 
or  the  reverse.  The  kinetic  energy  sometimes  beeomes  manifest  an 
flectricity  or  light,  but  most  frequently  as  heat.  In  some,  exothermic 
etioQs  heat  is  generated,  and  in  other,  cndothermic  reactions  heat 
f 


98  MANUAL  OP    CHEMISTRY 

is  absorbed  from  surrounding  bodies,  which  are  correspondingly 
cooled,  and  in  both  eases  to  a  definite  amount  of  heat  per  mol  of 
substance,  or  substances,  involved  in  the  reaction.  This  definite 
amount  of  heat,  measured  in  gram : calories  or  kilojoules  (p.  22),  is 
designated  as  positive  (  +  )  when  heat  is  liberated  in  exothermic 
reactions,  and  as  negative  ( — )  when  absorbed  in  endothermie 
reactions. 

The  act  of  solution  is  attended  with  a  thermal  effect,  either 
positive  or  negative.  The  heat  of  solution  of  a  substance  is  the 
amount  of  heat  generated  or  absorbed  in  the  solution  of  one  gram  of 
the  substance  in  a  large  quantity  of  water.  The  heat  of  solution  of 
gases  and  liquids  is  always  positive.  Thus,  for  chlorin  it  is  +4290 
cal.,  and  for  hydriodic  acid  +18630  cal.;  for  ethylic  alcohol  it  is 
+2000  cal.,  and  for  sulfuric  acid  +17850  cal.  The  heat  of  solution 
of  solids  is  sometimes  positive,  as  +12500  for  potassium  hydroxide 
but  most  frequently  negative,  as  — 1180  for  sodium  chlorid.  The 
heat  of  precipitation  of  difficultly  soluble  solids  is  the  negative  value 
of  their  heat  of  solution,  and  is  the  greater  the  more  difficultly  soluble 
the  substance  is.  Thus,  for  silver  chlorid,  bromid  and  iodid:  +15800, 
+20200,  and  +26600  cal.  respectively. 

The  heat  measurable  in  a  given  chemical  reaction  is  not  entirely 
the  result  of  the  reaction  itself,  and  is  not,  therefore,  a  measure  of 
the  "affinities"  of  the  substances  involved,  but  is  the  algebraic  sum 
of  a  number  of  factors,  some  positive,  others  negative,  of  physical 
and  chemical  character:  the  energy  required  to  split  the  molecule 
into  atoms,  the  combination  of  the  liberated  atoms  to  form  new 
molecules;  the  condensation  of  gases  or  vapors  to  liquids,  the  vapor- 
ization, solution  or  precipitation  of  products,  the  diminution  of  the 
number  of  molecules  in  unit  volume,  and  the  performance  of  external 
work. 

Usually  chemical  combinations  are  exothermic,  as  when  two 
molecules  of  hydrogen  and  one  molecule  of  oxygen  combine  to  form 
one  molecule  of  water  136,800  grarcal,  or  572  hj  of  heat  are  liberated. 
This  is  expressed  by  the  equations:  2H2+02=2U20+2X 68,400  cal, 
or  2H2+02=2H20+2X286  I'j.  But  some  combinations  are  endo- 
thermie, as  when  hydrogen  and  iodin  combine  to  form  hydriodic  acid: 
H2+l2=2HI— 2X6097  cal. =  —2X25  kj. 

Exothermic  reactions,  once  started,  continue  without  the  further 
addition  of  heat  energy,  sometimes  violently,  as  in  the  case  of  2H2  + 
02  =  2H20.  Endothermie  reactions  require  the  continued  supply  of 
heat  for  their  continuance.  The  greater  the  amount  of  heat  generated 
in  an  exothermic  reaction  the  more  readily  will  it  occur,  and  the  more 
stable  will  be  the  product.  Compounds  whose  formation  is  endother- 
mie are  formed  with  difficulty,  and  are  less  stable  than  a  mixture  of 


THEIIMOCHEMISTRY 


99 


their  constituents,  and  tlierefore  prone  to  decomposition.  For  this 
reasou  hydriodic  acid  is  used  in  organic  chemistry  as  a  source  of 
nttseent  hydrogen,  as  a  reducing  agent  (p.  108).  Compounds  whose 
formation  is  exotbennic  are  decomposed  by  the  addition  of  siiffifient 
liwt»  as  in  the  dissociation  of  vapor  of  water  and  other  vapors  end 
piHs  (p,  90).  The  decomposition  of  compounds  whose  formation  is 
endothermic  is  attended  by  evohition  of  heat,  as  in  the  decomposition 
of  nitrates  and  chlorates.  In  such  reactions  any  heat  imparted  from 
OQtside  serves  only  to  incite  the  decomposition. 

The  heat  of  fornaation  of  a  compound  is  the  heat  efFeet»  positive 
or  negative,  obf^erved  or  calculated »  attending  the  formatioti  of  one 
mol  of  the  compound  from  its  elements.  Thus  the  heat  of  formation 
of  water  is  +  68,400  cal,  that  of  hydriodic  acid  —6,097  caL 

The  heat  of  formation  of  compounds,  other  than  the  heats  of  com- 
bastion,  must  usually  lie  determined  indirectly.  Thus  the  heat  of 
formation  of  hydrogen  peroxid  cannot  be  directly  measured,  but  the 
heat  effect  of  the  formation  of  water  from  hydrogen  and  oxygen  can 
be,  HB  well  as  that  of  the  decomposition  of  hydrogen  peroxid  to  water 
and  oxygen.  The  former  is  represented  by  the  equation  (1):  2H2+ 
03=2H2O  +  2X68,40^)  cal,  and  the  latter  by  the  equation  (2)  t  2H2- 
0s=2H2OXO-i  + 2X23,193  cal.  Equation  2  may  be  transposed  to 
nead  (3) :  2H2O  +  Ou  =  2H^.02  —  2  X 23 ,193  cal ,  and,  adding  together 
equations  1  and  3  we  have:  2H2+ 20n^2H20L>  + 2X45,207.  The 
balof  formation  ot  hydrogen  peroxid  is,  therefore,  45,207  gm:cal, 
f>r  189  kj. 

When  a  mol  of  a  compound  is  decomposed^  the  heat  effect  is  equal 
l^iU  beat  of  formation,  hut  of  opposite  sign. 

The  heat  of  combustion  of  a  substance  is  the  amount  of  heat 
Hbfrated  by  the  complete  burning  of  one  mol  of  the  substance  in  an 
wce«R  of  pure  oxygen  under  pressure.  This  value  has  been  directly 
detirrained  for  a  great  number  of  organic  substances,,  by  burning 
kaowu  weights  in  a  cahrimefric  bmnb,  contained  in  a  tmter*calor- 
'wetfr,  where  the  heat  generated  is  measured  by  the  rise  of  the  tem- 
perature of  the  known  weight  of  water* 

The  heat  of  reaction  is  the  heat  effect,  positive  or  negative,  pro- 
d«ioed  in  any  reaction.  It  is  equal  to  the  sum  of  the  heats  of  forma- 
tion of  the  substances  produced,  minus  the  sum  of  the  heats  of  forma- 
hoij  of  the  substances  reacting.     Thus   the   heat  of   formation    of 

Irohromic  acid  is  8,369  cal,  and  that  of  hydrochloric  acid  is  21^997 

The  heat  of  reaction  of  2llBr  +  Cl^^  2HC1  +  Brs  is,  therefore, 

JX(21,997  — 8.369)  =  2X13, 628.    The  heat  of  reaction  may  also  be 

obtaiaed  from  the  heats  of  comViustion,   as  the  heat  of  reaction  is 

eqnul  to  the  sum  of  the  heats  of  combastion  of  the  reacting  suh- 

itmoeSt  minus  the  sum  of  the  heats  of  combnstion  of  those  formed. 


100 


MANUAL    OF    CHEMISTRY 


Thus  the  heats  of  combustion  of  acetic  acid,  ethylic  alcohol,  aod 
ethyl  acetate  are  respectively  2,100,  3,400  aud  5,540  cal,  and  there- 
fore the  heat  of   the  reaction  CHa.COOH  +  CH:,.CH2OH=CHa.CO0j 

(C2H5)  +  H20  is  (2, U>0+  3,400)  — (5,640  +  0)=  — 40  caL  ■ 

As  a  rule,  that  reaction  between  several  substances  present  in  a 
system  will  occur  which  will  result  in  the  formation  of  the  compound 
having  the  g:reatest  heat  of  formation.  Thus  the  heats  of  formation 
of  the  hydrogen  compounds  of  the  halogens  arer  for  HF+ 38,495 
cal,  for  HCl  +  21,997  cal,  for  HBr  +  8,369  cal,  and  HI— 6,097  cal, 
which  explains  why  reactions  such  as  2HBr+Cl2^2HCl+Br2  occur. 
Yet  these  reactions  do  not  proceed  to  completion;  they  are  reversible 
to  a  certain  extent  in  obedience  to  the  law  of  mass  action. 

The  heat  of  reaction  between  a  given  pair  of  substances  is  not  the 
game  at  all  temperatures  of  the  reaction  if  the  substances  be  gaseous 
or  liquid.  It  varies  with  the  specific  heats  of  the  substances  involved 
in  such  manner  that  the  excess  of  the  molecular  heats  of  the  reacting 
substances  over  the  molecular  heats  of  the  products  represents  the 
increase  of  the  heat  of  reaction  for  each  degree  of  temperature  eleva- 
tion»  But  as  in  solid  substances  the  molecular  heats  arc  additive, 
i.  e,,  the  sum  of  the  atomic  heats,  the  heat  of  reaction  between  solid 
substances  is  independent  of  the  temperature.  ' 

When  solutions  of  salts  are  mixed  there  is  no  heat  effect  unless 
a  precipitate  or  a  volatile  compound  is  formed,  i.  e.,  unless  the  ions 
unite  to  form  an  electrically  neutral  molecule.  The  heat  effect  pro-  | 
doced  by  the  union  of  two  ions  to  form  a  neutral  molecule  is,  of 
course,  always  the  same  for  the  same  two  kinds  of  ion,  and,  there- 
fore, the  heat  of  netitralization  between  strong  acids  and  strong 
bases  in  dilute  solution  is  a  constant  quantity,  viz.,  13,700  cal,  pro- 
vided tliey  do  not  form  precipitates,  because  the  ionic  reaction  which 
is  common  to  all  is  H"+0H'=H20,  or  (H'aq.,OH'aq.)  =  13J00 
cal»  in  which  aq  represents  a  large  quantity  of  water.  With  weak 
acids  or  bases,  which  are  less  completely  dissociated,  the  heat  of 
neutralization  is  greater  or  less  than  13^700  caL  Thus,  with  potassium 
or  sodium  hydroxid  and  acetic  acid  it  is  13,400  cal,  with  the  same 
bases  and  phosphoric  acid  it  is  14,830  caK  and  with  ammonium 
hydroxid  and  hydrochloric  acid  it  is  12^300  caL  The  difference 
between  these  values  and  13,700  cal  is  the  heat  of  dissociation  of 
the  weak  acid  or  base,  which  may  be  positive  or  negative:  +300  cal 
for  acetic  acid,  ^-1,130  cal  for  phosphoric  acid,  and  +1,400  cal  for 
ammonium  hydroxid.  j 

Classification  of  the  Elements, — The  elements  are  best  classified 
according  to  rf*seuiblances  in  their  chemical  properties.  We  will 
adopt  such  a  classification,  based  upon  the  nature  of  the  oxids  and 
the  existence  or  nonexistence  of  oxj'salts: 


i 


CLASSIFICATION    OP   ELEMENTS  101 

Class  I.  Typical  Elements. 
Hydrogen.  Oxyg^en. 

Although  these  two  elements  differ  notably  in  their  properties, 
they  are  here  classed  as  typical  elements^  because  together  they  form 
the  basis  of  our  classification;  they  both  play  important  parts  in  the 
formation  of  acids;  neither  would  find  a  suitable  place  elsewhere  in 
the  chissification;  and  they  may  also  be  considered  as  typical  from 
the  point  of  view  of  ionization,  as  they  form  the  characterizing  ions 
of  acids  and  bases,  hydrion  and  hydroxidion. 

Class  II. 

Elements  iehich  form  no  compounds: 
Helium,  neon,  argon,  krypton,  xenon. 

Class  III.  Acidulous  Elements. 

Elements  whose  oxids  unite  with  water  to  form  acids,  never  to  form 
Ixues,    Which  do  not  form  oxysalts. 
Group      I. — Flnorin,  chlorin,  brorain,  iodin. 
Group     II. — Sulfur,  selenium,  tellurium. 
Group  III. — Nitrogen,  phosphorus,  arsenic,  antimony. 
Group   IV. — Boron. 
Group     V. — Carbon,  silicon. 
Group  VI. — Vanadium,  niobium,  tantalium. 
Group  VII. — Molybdenum,  tungsten,  osmium. 

Elements  of  this  class  are  also  called  non-metals,  in  contradis- 
tinction  to  those  of  classes  IV  and  V,  which  are  collectively  called 
metals.  They  are  also  referred  to  as  electronegative  elements, 
because  they  are  electronegative  to  hydrogen,  although  they  are  all 
electropositive  to  oxygen,  and  individual  members  are  also  electro- 
positive to  others  of  the  class  (p.  62).  On  electrolysis  of  compounds 
containing  acidulous  elements  or  oxygen,  and  metals  or  hydrogen, 
the  former  are  usually  found  in  the  anion,  the  latter  in  the  cation,  as 
H'K'  I  SO4".  But  this  is  not  invariably  the  case.  Thus,  on  elec- 
trolytic separation  of  a  solution  of  sodium  sulfantimonite  elementary 
antimony  is  deposited  at  the  cathode. 

Class  IV.  Amphoteric  Elements. 

Elements  whose  oxids  unite  with  water,  some  to  form  bases,  other 
U  form  acids.    Which  form  oxysalts. 

Group       I.^Oold. 

Group      II. — Chromium,  manganese,  iron. 


102  MANUAL   OP   CHEMISTRY 

Group     HI. — Radium,  thorium,  uranium. 

Group    IV. — Lead. 

Group      V. — Bismuth. 

Group    VI. — Titanium,  germanium,  zirconium,  tin. 

Group  VII. — Palladium,  platinum. 

Group  Vin. — Rhodium,  ruthenium,  iridium. 

The  amphoteric  and  basylous  elements  are  the  metals  or  electro- 
positive elements,  and  have  these  properties  in  common :  they  form 
oxysalts,  and  are  separated  as  cations  on  electrolysis  of  such  salts. 

Class  V.     Basylous  Elements. 

Elements  whose  oxids  unite  with  water  to  form  hoses,  never  to  form 
acids.    Which  form  oxysalts. 

Group        I. — Lithium,    sodium,   potassium,   rubidium,    cesium, 

silver. 
Group      II. — Thallium . 
Group     III. — Calcium,  strontium,  barium. 
Group     IV. — Magnesium,  zinc,  cadmium.. 

Group      V. — Beryllium,  aluminium,  scandium,  gallium,  indium. 
Group    VI. — Nickel,  cobalt. 
Group   VII. — Copper,  mercury. 
Group  Vin. — Yttrium,  lanthanum,  cerium,  praseodymium,  neody- 

mium,  samarium,  gadolinium,  terbium,  thulium, 

ytterbium. 

This  class  includes  the  more  strongly  electropositive  metals. 

In  classes  III,  IV  and  V  the  elements  are  subdivided  into  groups, 
the  members  of  which  have  common  distinctive  characters,  and  are 
more  or  less  closely  allied-  to  each  other.  In  classes  III  and  V  the 
resemblances  between  individuals  of  groups  occurring  first  in  the  list 
are  the  most  marked,  and  are  more  close  than  those  between  members 
of  groups  placed  lower  down. 

Periodic  Law. — If  the  elements  be  arranged  in  a  continuous  series 
in  the  numerical  order  of  their  atomic  weights:  H,  He,  Li,  Be,  etc., 
it  will  be  found  that  elements  having  similar  properties,  in  them- 
selves and  in  their  compounds,  will  be  separated  from  each  other  by 
regular  but  increasing  spaces  or  "periods."  Thus  the  members  of  the 
group  F,  CI,  Br,  I,  will  be  separated  by  7,  17,  17  spaces,  and  the 
members  of  the  group  Li,  Na,  K,  Rb,  Cs  by  7,  7,  17,  17  spaces.  If 
now  these  periods  be  arranged  in  parallel  columns,  as  shown  in  the 
table  on  page  103  for  example,  it  will  be  found  that  elements  having 
similar  properties  will  fall  in  the  same  (horizontal)  line.  It  will  be 
observed,   however,  that  in  order  to  attain  this  result  it  has  been 


PERIODIC    LAW 


103 


H 
1.006 

U 
7.08 

Na 

23.06 

K 

Rb 
85.4 

Cs 
183. 

—  -    - 

Ca 
40.1 

8r 

87.6 

Ba 

137.4 
La 
138 

Ra 
225 

-- 

Ce 
140 

Th 
882.5 

Pr 
140.5 

Nd 
143.6 

Sa 
150.3 

En 
151.7 

U 
288.5 



Od 
156 

Tb 
160 

Ho 
162 

Er 
166 

Tm 
171 

Ac 
f 

1 

Yx 

173 

Se 
44.1 

Yt 
89 

Tl 
48.1 

Zr 

90.7 

V 
51.2 

Nb 
94 

Ta 
183 



Cr 
52  1 

Mo 
96 

W 

184 

Mn 
55 

Fe 
55.0 

Ra 
101.7 

Os 
191 
Ir 
193 

i 

59 

Rh 
103 

Ni 

Pd 
106 

Pr 
194.8 

Be 

9.1 

63.6 

Ak 
107.93 

An 
197.2 

Mg 

24.36 

Zn 
65.4 

Cd 
112.4 

Kg 
200.3 

Tl 
204.1 

B 

11 

•       Al 
27.1 

Oa 
70 

In 
114 

1               1 

C 
12 

Si 
28.4 

Ge 
72.5 

8n 
118.5 

Pb 
206.9 

Bl 
208.5 

1                  ' 

i 

7_ i 

1 

N 

14.04 

P 
31 

As 

75 

Sb 
120.2 



O 
16 

S 
32.06 

S« 
79.1 

127.6 

He 

4 

F 
19 

CI 

Br 
70.96 

I 

Ne 

20 

A 

89.9 

Kr 

81.8 

X 

128 

inM?essar>'  to  reverse  the  order  of  three  pairs  of  elements:  A  and  K, 
Co  :ind  Ni,  and  Te  and  I;  but  with  these  alterations  the  periodicity 
of  recurrence  of  related  elements  will  be  particularly  noticeable  by 


104  MANUAL    OF    CHEMISTBT 

comparing:  the  first  two  and  last  four  of  the  horizontal  lines  of  thd 
table  with  the  previoos  classification  of  elements.  This  connection 
between  the  periodicity  of  the  atomic  weights  of  the  elements  and 
their  chemical  relationships  is  expressed  in  the  Periodic  law  of  Men- 
delejeff:  The  properties  of  elements,  the  constitution  of  their  com- 
pounds, and  the  properties  of  the  latter  are  periodic  functions  of  the 
atomic  weights  of  the  elements.  But  the  law  is  not  absolute,  and, 
apart  from  the  necessity  of  transpositions  to  adapt  it  to  the  obvious 
relationships  mentioned  above,  the  separation  into  different  groups  of 
such  closely  related  elements  as  Cu  and  Hg,  Cr,  Mn  and  Fe,  and  Co 
and  Ni,  and  the  grouping  together  of  such  dissimilar  elements  as  Cu, 
Ag  and  Au  are  not  in  accordance  with  observed  fact. 

It  will  be  observed  that  the  series  is  complete,  with  but  a  single 
break,  between  H  =  1.008  and  Nd  =  143.6,  but  that  above  that  point 
the  breaks  are  numerous.  When  the  earlier  tables  were  constructed 
(about  1870)  the  breaks  were  more  numerous,  but  have  been  in  part 
filled  by  the  discovery  of  then  unknown  elements,  such  as  scandium, 
germanium,  and  the  entire  argon  group.  It  may,  therefore,  be 
expected  that  other  breaks,  still  existing,  may  be  filled  by  the  dis- 
covery of  other  new  elements  of  very  high  or  very  low  atomic  weights. 
In  this  connection  it  may  be  noted  that  there  is  some  reason  for  the 
belief  that  a  third  element  may  exist  between  H  and  He,  and  that 
there  may  be  another  period  of  three  elements,  of  lower  atomic 
weights  than  that  of  hydrogen. 


INORGANIC  CHEMISTRY. 


CLASS  I.— TYPICAL  ELEMENTS. 


HYDROGEN  —  OXYGEN. 


Although,  in  a  strict  sense,  hydrogen  is  regarded  by  most 
chemists  as  the  one  and  only  type -element  —  that  whose  atom  is 
the  unit  of  atomic  and  molecular  weights  —  the  important  part 
which  oxygen  plays  in  the  formation  of  those  compounds  whose 
nature  forms  the  basis  of  our  classification,  its  acid-forming  power 
in  organic  compounds,  and  the  differences  existing  between  its  prop- 
erties and  those  of  the  elements  of  the  sulfur  group,  with  which  it  is 
usually  classed,  warrant  us  in  separating  it  from  the  other  elements 
and  elevating  it  to  the  position  it  here  occupies. 

HYDROGEN. 

Symbol  =  H  —  Univalent  —  Atomic  weight  =  1  (1.008  —  0  =  16) — 
Molecular  weight  =  2  (2.016— 0  =  32)  — /Sp.  gr.  =  0.06926A— One 
litre  weighs  0.0899  gram  — 100  cubic  inches  weigh  2.1496  grains  — 
1  gram  measures  11.16  litres  —  I  grain  measures  46.73  cubic  inches 
— Name  derived  from  v^p= water,  and  y^vvaAa=l  produce — Discovered 
hy  Cavendish  in  1766. 

Occurrence. — Occurs  free  in  volcanic  gases,  in  fire-damp,  occluded 
in  meteorites,  in  the  gases  exhaled  from  the  lungs,  and  in  those  of 
the  stomach  and  intestine.  In  combination  in  water,  hydrogen 
gulfid,  ammoniacal  compDunds,  and  in  many  organic  substances. 

Preparation. — (1)  By  electrolysis  of  water,  H  is  given  off  at 
the  negative  pole.     Utilized  when  pure  H  is  required. 

(2)  By  the  dissociation  of  water  at  very  high  temperatures. 

(3)  By  the  decomposition  of  water  by  certain  metals.     The  alkali 

metals  decompose  water  at  the  ordinary  temperature: 

Naa  -f  2H2O  =  2NaH0  +  Hj 

Sodium.  Water.  Sodium  hydrozid.  Hydrogen. 

Some  other  metals,  such  as  iron  and  copper,  effect  the  decompo- 
sition only  at  high  temperatures: 

3Fe2  +  8H2O         =         2Fe304  +  8H2 

Iron.  Water.  Triferric  tetroxid.  Hydrosen. 

(105) 


MAKUAL    OF    CHEMISTRY 


(4)  By  decomposition  of  water,  pasi^ed  over  red-hot  coke: 


C 


+ 


2H2O 
W»ter. 


or  at  a  higher  temperature: 


C 

Carbon. 


+ 


H2O 

Wttter- 


C(>2 

Carbon  ilioxid. 


CO  4- 

OarboD  munoxid. 


2Ha 
Hydrojcen. 


Hj 
HydrojEen. 


(5)  By  decomposition  of  mineral  acids,  in  the  presence  of  water 
by  zinc  and  certain  other  metals: 


Zn 

7Ane. 


H.SOj       -f      i:H:0      =       ZnSOi       +       Hj      +      arH.O 
Sulfuric  Acltl.  Whter.  Ztue  sulfAte.        Hydrocen.  Wnter. 


The  water  serves  to  dissolve  the  zinc  sulfate.  Chemically  pui*© 
zinc,  or  zinc  whose  surface  has  been  covered  with  an  alloy  of  zinc 
and  mercury,  does  not  decompose  the  acid  unless  it  forms  part  of 
a  galvanic  battery  whose  cinniit  is  closed.  The  zincs  of  galvanic 
batteries  are  therefore  covered  with  the  alloy  mentioned  — are  amal- 
gamated—  to  prevent  waste  of  zinc  and  acid. 

This  is  the  method  nsnally  resorted 
to  for  obtaining  H.  The  gas  so  ob- 
tainedt  is,  however,  contaminated  with 
small  quantities  of  other  gases,  hydro- 
gen phosphid,  sulfid  and  arsenid. 

Hydrogen,  carbon  di- 
oxid,  hydrogen  sulfid,  and 
other  gases  produced  hy 
the  action  of  a  liquid  upon 
a  solid  at  ordinary  tniiper- 
atures,  are  best  prepared  in 
one  of  the  forms  of  appa* 
ratus  shown  in  Pigs.  25* 
2G  and  27, 

The  solid  material  is 
placed  in  the  larger  bottle 
(Fig.  25),  or,  over  a  layer  of  broken  glass  about  five  centimeters 
thick,  in  the  bottle  a  (Pig,  26),  The  liquid  reagent  is  from  time 
to  time  introduced  by  the  funnel  tube^  Fig*  25;  or  the  bottle  &, 
Pig.  26,  is  filled  with  it.  The  wash -bottles  are  partially  filled  with 
water  to  arrest  any  liquid  or  solid  impurity.  The  ai^paratns,  Figs. 
26  and  27,  have  the  advantage  of  being  always  ready  for  use.  When 
the  stopcock  is  open  the  gas  escapes.  When  it  is  closed  the  internal 
pressure  depresses  the  level  of  the  liquid  in  a  into  the  layer  of  broken 
glass,   and   the   action    is   an^sted,    Kipp-s  apparatus.   Fig,   27.    is 


Fto    25. 


another  convenient  form  of  constant  apparatus. 
is  placed  in  the  central  bulb. 


The  solid  reagent 


HYDROGEN 


107 


Fio.  an. 


(6)  By  heating  together  a  mixture  of  zinc  dust  and  dry -slacked 
lime: 

Zn          -f          CaEaO.         =  ZnO         -f         CaO          +         Hi 

Ziue,                  Chldnm  hydroxld.  Zinc  oxid.            CnJek  moai>zid.          Hydroitn. 

Properties. — PhpaiatL — Hydrogen  is  a  colorless,  odorless »  taste- 
less gras;  14.47  times  lighter  than  air,  being  the  lightest  siibstauee 
known.  The  weight  of  a 
litre,  0,0Hii!6  gram*  is  called 
a  cri  tb  ( *ip^H = barleycorn ) . 
(From  this  the  weight  of  a 
litre  of  any  ga^  may  be 
ealcnlnted  by  multiplying 
half  its  molecnlar  weight 
by  .(m06.  It  is  nlmost  in- 
Rolable  in  water  and  alco- 
hol. It  conducts  heat  and 
♦•lectricity  better  than  any 
<»ther  gas.  In  obedience 
to  rbe  law:  The  dif fusi- 
bility of  two  gases  varies  inversely  as  the  square  roots  of  their 
densities*  it  is  the  most  rapidly  diffusible  of  gases.  The  rapidity 
with  which  this  rliifiision  takes  place  renders  the  use  of  hydrogeii, 
which  has  been  kept  for  even  a  short  time  in  gas-bags  or  gasometers, 
dangerous.  It  is  liquefied  at  — 240"*  (  —  400''  F.) 
under  a  pressure  of  13,3  atm.  The  liquid  is  clear 
and  colorless,  boils  at — 253^,  only  20°  above  the 
absolute  zero,  and  has  a  sp.  gr.  of  0.068, 

Certain  metals  have  the  power  of  absorbing  large 
quantities  of  hydrogen »  which  is  then  said  to  be 
occluded,  Palladiuin  absorbs  980  vol- 
umes ot  the  gas  when  used  as  the  neg- 
ative electrode  in  the  electi'olysis  of 
water.  The  occluded  gas  is  driven  off 
by  the  application  of  heat,  and  possesses 
great  eheniical  activity,  similar  to  that 
which  it  has  when  in  the  nascent  state. 
This  latter  quality,  and  the  fact  that 
heat  is  liberated  during  the  occlusion, 
would  seem  to  indicate  that  the  gas  is 
contahied  in  the  metal^  not  in  a  raere 
physical  state  of  condensation,  but  in 
chemical  combination . 
ChtmicuL — Hydrogen  exhibits  uo  great  tendency  to  combine  with 
■  oilier  elements  at  ordinary  temperatures.     It  combines  explosively, 


fia.  t7. 


108 


MANUAL    OF    CHEMISTRY 


however,  with  chlorin  under  the  influence  of  sunlight,  and  with 
fluorin  even  in  the  dark.  It  does  not  support  combustion,  but,  when 
iguited,  bnrnH  with  a  pale  blue  and  very  hot  flame;  the  result  of  the 
combination  being  water.  Mixtures  of  hydrogen  and  oxygen  ex- 
plode violently  on  the  approach  of  flame,  or  by  the  passage  of  the 
electric  spark,  the  expl fusion  being  caused  by  the  sudden  expansion 
of  the  vapor  of  water  formed,  under  the  influence  of  the  heat  of  the 
reaction.  In  a  mixture  of  hydrogen  and  oxygen  at  the  ordinary 
temperature  forraatiou  of  water  takes  place  with  extreme  slowness 
(p.  91).  If  a  piece  of  platinum  foil  be  introduced  into  the  mixture 
combination  oecui's  with  sensible  rapidity,  and,  if  the  platinum  be 
finely  divided,  the  rapidity  of  the  combination  is  such  that  the  metal 
becomes  incandescent,  and  explodes  the  mixture.  The  platinum  here 
is  said  to  be  a  catalyser,  i.e.,  a  substance  by  whose  presence  the 
velocity  of  a  reaction  is  accelerated,  Oatalj^sers  are  also  called 
contact  agents.  Many  compounds  containing  oxygen  give  up  that 
element  when  heated  in  an  atmosphere  of  hydrogen: 


CuO 

Cnprte  oi!d. 


Hydrogen, 


copper. 


Water* 


The  removal  of  oxygen  from  a  compound  is  called  a  reducHon 
or  deoxidalion.  In  a  broader  sense  the  term  reduction  is  applied  tr* 
any  diminution  in  the  relative  quantity  of  the  electro-negative 
factor  in  a  compound.  Thus  mercuric  chku-id,  HgCl^j  (Hg  200:  CI 
71)  is  redured  to  merenrous  chlorid,  Hg^Cl-j  ( Hg  200 r   CI  35*5). 

At  the  instant  that  H  is  liberated  from  its  compounds  it  has  a 
deoxidizing  power  similar  to  that  which  ordinary  H  possesses  only 
at  elevated  temperatures,  and  its  tendency  to  combine  with  other 
elements  is  greater  than  under  other  conditions.  The  greater 
energy  of  H,  and  of  other  elements  as  well,  in  this  nascent  state, 
may  be  thus  explained.  Free  H  exists  in  the  form  of  molecules, 
each  one  of  which  is  composed  of  two  atoms,  but  at  the  instant  of 
its  liberation  from  a  compound,  it  is  in  the  form  of  individual  atoms, 
and  that  portion  of  force  required  to  split  up  the  molecule  into 
atoms,  necessary  when  free  H  enters  into  reaction,  is  not  required 
when  the  gas  is  in  the  nascent  state. 

In  its  physical  and  chemical  properties,  this  element  more  closely 
resembles  those  usually  ranked  as  metals  than  it  does  those  forming 
the  class  of  non-metals,  among  which  it  is  usually  placed.  Its  con- 
ducting power,  as  well  as  its  relation  to  the  acids,  which  may  be 
considered  as  salts  of  H,  tend  to  separate  it  from  the  non-metals. 

Anal3^ical  Characters. — (1)  Burns  with  a  faintly  blue  flame, 
which  deposits  water  on  a  cold  surface  brought  over  it;  (2)  Mixed 
with  oxygen,  explodes  on  contact  with  flame,  producing  water. 


OXYGEN 


109 


OXYGEN* 

8ifmhol  =  0 — Bivalent  —  Atomic  weight  ^^15,B7  (16);  molecular 
w$igkt^31J4  m)~Sp.gr  =hlOm3  A  (calculated  =  1.10SS};  15.95 
H;  »p,  gr,  of  liquid  =0.9181  —  One  Hire  weighs  1.429  grams;  100 
cubic  inches  weigh  34,27  grains  —  Name  derived  from  oiv'i^acidf  aad 
ycvmw=J  prmluce — Discovered  hy  Mayow  in  1674  ^  rediscomred  by 
Priestley  in  1774. 

Occurrence.— Oxygen  is  the  most  abundant  of  the  elements.  It 
exists  free  in  atmospheric  air;  in  combination  in  a  great  number 
of  enbstances,  mineral,  vegetable,  and  aniraai. 

Preparation,^  (1)  By  heating  certain  oxids: 

2HgO  =  2Hp:  -h  02 

Msreario  ozid,  blerc  nry.  Oxjcvn, 

too  grams  of  mercuric 


This  was  the  method  used  by  Priestley. 
oxid  produce  5.16  litres  of  oxygen: 

3Mn02  —  MujO* 


MftiiffAnete  dioxid. 


TrimuiKiiQic  t<*troxld. 


+        o, 

0x72^11, 


The  black  oxid  of  manganese  is  heated  to  redness  in  an  iron  or 
eliiy  retort  (Scheele,  1775);  and  1*X)  grams  yield  8.51  litres  of 
oxyg«?n. 

(2)  By  the  electrolysis  of  water,  acidulated  with  sulfuric  acid, 
O  is  given  off  at  the  positive  pole. 

(3)  By  the  action  of  sulfuric  acid  upon  certain  compounds  rich 
io  O:  manganese  dioxide  potassium  dichromate,  and  plumbic  peroxid: 

SMnOa         4         2H,SOi        =        2Mn80j         +       Sn.O      +        Oj 
UHttfMiM*  dldxkL  StLlfuric  Acid,  Mnnjeaiiotu  sulfate.  Water.  Oxyeva. 

100  grams  of  manganese  dioxid  produce  12.83  litres  of  O* 

(4.)  By  decomposing  H2SO4  at  a  red  beat,  2H2S04=2S02  + 
2HiO  +  O2. 

(5)  By  the  decomposition  by  heat  of  certain  salts  rich  in  0: 
alkaline  permanganates,  nitrates^  and  chlorates. 

The  best  method,  and  that  usually  adopted,  is  by  heating  a 
niixture  of  potassium  chlorate  and  manganese  dioxid  in  equal  partis, 
inotlerately  at  first  and  more  strongly  toward  the  end  of  the  reaction. 
the  chlorate  gives  up  all  its  O  (27.33  litres  from  100  grams  of  the 
salt)^  according  to  the  equation: 


2KCI03 


PotB 


2KC1 
«ium  ehlorid. 


303 

Ox78«ll> 


Al   the   end    of   the   operation    the   manganese   dioxid   remains, 

"mtly  unchanged, 
A  small  quantity  of  free  chloriu  usually  exists  in  the  gas  pro- 


110 


MANUAL    OF    CHEMISTRY 


duced  by  this  reaction .  If  the  oxygen  is  to  be  used  for  inhalation^ 
the  chlorin  should  be  removed  by  allowing  the  gas  to  stand  o\^ei- 
water  for  24  hours. 

When  heat  is  required  for  the  generation  of  gases  the  operation  is 
<.'ondueted  in  retorts  of  glass  or  metal,  or  in  the  apparatus  shown  in 
Fig.  28.     If  the  gas  be  colleeted  over  water  the  disengagement  tube 


.Flo   28. 

must  be  withdrawn  from  tlie  water,  before  the  source  or  heat  i>f 
removed.  Neglect  of  this  preeautiou  will  cau8e  an  explosion,  by  the 
the  entrance  of  water  into  the  hot  flask,  by  the  contraction  of  thtt 
gas  contained  in  it,  on  partial  cooling. 

(6)   By  the  action  of  water  upon  sodium  peroxid  : 

-f 


2N112O2 


2HiO 

Water, 


4NaH0  + 

Sodium  hydroxid. 


O2 

Oxygen. 


(7)  By  the    mutual    decomposition    of   potassium    permanganate 
and  hydrogen  peroxid,  in  the  presence  of  sulfuric  acid: 


HnOj 

Hfdroffen  peroxid. 


Pota«sium  fxTrnftneaiiiktc. 


3H2SO4 

Sulfuric  Rcid. 


2MtiS04 
Mft.iig»D{)U8  sulfate. 


-I- 


4H.0 

Wiitpr. 


=         K5SO4 
Potiutttium  ttuLfrnta, 

3O2 

Oxy^n. 


One  kilo  H2O2  (3  per  cent)  and  500  ee.  dilute  H2SO4  (1:5)  ai-e 
placed  in  the  generating  flask  and  56  grams  K-iMn^Oi^,  dissolved  in 
H2O,  art'  gradually  added.  With  these  quantity's  20  litres  0  are 
oVjtained, 

(8)  By  the  action  of  dilute  hydrochlorie  acid  upon  a  mixture  of  2, 


OXYGEN 


111 


parts  barium  peroxid,  1  part  inun^iMiese  dioxid,  and  1  part  plaster  of 
Paris*  compresscHl  into  cubes  nljc*nt  ll^  t»ent*  square. 

Methods  6,  7,  and  8  have  the  advantage  that  heat  is  not  required > 
iind  the  forms  of  apparatus,  Figi5,  25»  2ti  aad  27,  may  be  used.        ' 

Properties, — Phtjitiatl.^Oxyi^f'n  is  a  eolorless,  odorless,  tasteless 
5jii»,  tjuhible  in  water  in  the  proimrtiou  of  7.08  ec\  in  1  litre  of  water 
lit  14-8*  (58.6°  FJ,  somewhat  more  soluble  in  absolute  aleohoL  It 
liquefies  at  — 140°  (—220*'  F,)  under  a  pressure  of  300  atmospheres. 
Liquid  oxygeu  boils  at^l^7.4*'  (—294.5''  F.)  at  the  ordinary  pres* 
sure.     The  sp,  gr.  of  liquid  oxygen  is  0.9787. 

Chemical. —  Oxygen  is  eharaeterized,  eiieinieally,  by  the  strong" 
tendency  which  it  exhibits  to  enter  into  eonibination  with  other  ele- 
toeDts.  It  forms  binary  compounds  with  all  elements  except  Huorin 
and  bromin.  With  most  elements  it  unites  directly,  especially  at 
€?levated  temperatures.  In  many  instances  this  union  is  attended  by 
the  nppearaoce  of  light,  and  always  by  the  extrication  of  heat.  The 
InmiDous  union  of  O  with  another  element  constitutes  the  familiar 
phenomenon  of  combustion,  and  is  the  principal  source  from  which 
we  obtain  so-called  artificial  heat  and  light.  A  body  is  said  to  ho 
combustible  when  it  is  capable  of  so  energetically  combining  with 
the  oxygen  of  the  air  as  to  liberate  light  as  well  as  heat.  Gases  an> 
naid  to  be  supporters  of  combustion^  when  combustible  subsfanc^s 
will  unite  with  them,  or  wilh  some  of  their  coiistitnents,  the  uiiina 
being  attended  with  the  appearance  of  heat  and  light.  The  distinc- 
tion I>etween  combustible  sul)stances  and  supporters  of  combustion 
is,  however,  one  of  mere  convenience.  The  action  taking  place  be* 
tween  the  two  substances,  one  is  as  much  a  party  to  it  as  the  other. 
A  j*?t  of  air  burns  in  an  atuTOsphere  of  coal-gas  as  readily  as  a  jet  of 
roal*gas  burns  in  air. 

An  oxidation  is  a  chemical  action  in  which  oxygen  combines 
with  an  clement  or  a  compound.  The  burning  of  coal:  C+U^CQ 
nr  C + 02^=^02 ;  and  the  formation  of  acetic  acid  from  alcohoh 
rC?H#O+02=C2H4O'i+nt;O.  are  oxidations.  In  a  broader  sense  the 
rord  ^'oxidation''  is  sometimes  used  as  tlie  opposite  to  "reduction" 
(p.  62)  to  apply  to  any  increase  in  the  relative  quantity  of  the  electro- 
negative element  in  a  compound.  Thus  the  conversion  of  FeClj  (Fc 
1 12: CI  142)  into  Fe^Cle  fFe  112:(1  213)  may  be  referi-ed  to  as  an 
oxidiilion,  altliough  it  is,  more  properly,  a  chlorination. 

The  compounds  of  oxygen— the  oxids — are  divisible  into  three 
groups: 

1 ,  Anhydrids.^Oxids  capable  of  coujbiniiig  with  water  to  form 
<fri''x.  Thus  sulffinc  nnhyjdrid,  SO3,  unites  with  water  to  form 
Bulfurir  acid,  Hai^Oi. 

Th(*  term  anhydrid  is  not  limited  in  application  to  binary  com- 


n2 


MANUAL    OF    CHEMISTKV 


I 


pounds,  but  applies  to  aoy  substaoce  capable  of  combiuing  with  water 
to  form  an  acid.      Thus  the  eumpouod  CjHeOa  is  known  as  acetic 
anhydrid,  because  it  combines  with  water  to  form  acetic  acidt  CiHtjO;!  m 
+H20=2C2H402.     (See  conipoujids  of  arsenic  and  sulfur  J  | 

2.  Basic  oxids  are  such   as  combine  with  water  to  form  bases. 
Thus  calcium  oxid,  CaO,  unites  with  water  to  form  calcium  bydroxid,  _ 
CaHaOa.  | 

3.  Saline,  neutral  or  indifferent  oxids  are  such  as  are  neither 
aeid  nor  basic  in  character.  In  some  instances  they  are  essentially 
neutral,  as  in  the  case  of  the  protoxid  of  hydrogen,  or  water.  lu 
other  cases  they  are  formed  hy  the  union  of  two  other  oxids,  one 
basic,  the  other  acid  in  quality,  such  as  the  red  ox  id  of  lead,  PV^aOi, 
formed  by  the  union  of  a  mole<]ule  of  the  acidulous  peroxid,  PbOs, 
with  two  of  the  basic  protoxid,  PbO.  It  is  to  oxids  of  this  character  ■ 
that  the  term  -^saline''  properly  applies.  f 

The  process  of  respiration  is  very  similar  to  combustion,  and  as 
oxygen  gas  is  the  best  supporter  of  combustion,  so,  in   the  diluted  ^ 
form  in  which  it  exists  in  atmospherie  air,  it  is  not  only  the  best,  but  ■ 
the  only  supporter  of  animal  respiration.     (See  Carbon  dioxid.) 

Analytical  Characters, —  1.  A  glowing  match-stick  bursts  into 
flame  in  free  oxygen.  2.  Free  O,  when  mixed  with  nitrogen  dioxid, 
produces  a  brown  gas. 

Ozone. — Ailotropic  oxygen. — Air  through  which  discharges  of 
static  electricity  have  been  passed,  and  oxygen  obtained  by  the  de- 
composition of  water  (if  electrodes  of  gold  or  platinum  be  used), 
have  a  peculiar  odor,  somewhat  resembling  that  of  sulfur,  which  is 
due  to  the  conversion  of  a  part  of  the  oxygen  into  ozone. 

Ozone  is  produced:  1.  By  the  decomposition  of  water  by  the  bat- 
tery, 2.  By  the  slow  oxidation  of  phosphorus  in  damp  air.  3.  By 
the  action  of  concentrated  sulfuric  aeid  upon  barium  dioxid.  4,  By 
the  passage  of  silent  electric  discharges  through  air  or  oxygen. 

In  the  preparation  of  ozonized  oxygen  the  best  results  are 
obtained  by  passing  a  slow  current  of  oxygen  through  an  apparatus 
made  entirely  of  glass  and  platinum,  cooled  by  a  current  of  cold 
water,  and  traversed  by  the  invisible  discharge  of  an  induction  coil. 

Pure,  liquid  ozone  has  been  obtained  by  sulijeeting  ozonized 
oxygen  to  the  temperature  of  liquid  oxygen  at  the  atmospheric 
pressure.  It  is  a  dark  blue  liquid,  almost  opaque  in  layers  2  mm. 
thick,  which  is  not  decomposed  at  the  ordinary  temperature,  but 
converted  into  a  bluish  gas.     It  boils  at  —119°   (— 182.2°F.). 

When  oxygen  is  ozonized  it  contracts  sliglitly  in  volume,  and 
when  the  ozone  is  removed  from  ozonized  oxygen  by  mercury  or 
potassium  iodid  the  volume  of  the  gas  is  not  diminished.  These 
facts,  and  the  great  chemical  activity  of  ozone^  have  led  chemists 


I 

I 


I 


I 


WATER 


115 


to  regard  it  as  condensed  oxyfr^n;  the  molecnle  of  ozone  beings 
represented  thus  (000),  while  that  of  ordinary  oxygen  is  (00). 

Ozone  is  very  sparingly  soluble  in  water,  more  soluble  in  the 
preseace  of  hypophosphites,  insoluble  in  solutions  of  acids  add 
alkalies.  In  the  presence  of  moisture  it  is  slowly  converted  into 
toygen  at  100^  (212'"  FJ,  a  cbangre  wbieh  takes  place  rapidly  and 
corat»leteIy  at  237°  (459°  PJ  It  is  a  powerful  oxidant;  it  decom- 
poses solutions  of  potassinm  iodid  with  formation  of  potassium 
hjilroiid,  and  liberation  of  iodin;  it  oxidizes  nil  metals  except  gold 
and  platinum,  in  the  presence  of  moisture;  it  decolorizes  indigo  and 
other  organic  pigments,  and  acts  rapidly  upon  rubber,  cork,  and  other 
organic  substances. 

Analytical  Characters. ^1.  Neutral  litmus  paper,  impregnated 
with  solution  of  i>otassiuai  iodid,  is  turned  blue  when  exposed  to  air 
t'ODtaining  ozone.  The  same  litmus  paper  without  iodid  is  not  aflFected, 
2.  Jlaaganous  sulfate  solution  is  turned  brown  by  ozone.  3.  Solu- 
tions of  thallous  salts  are  colored  yellow  or  brown  by  ozone.  4. 
Paper  impregnated  with  Ircsh  tincture  of  natural  (unpurified)  gnai- 
acara  is  colored  blue  by  ozone.  5.  Paper  impregnated  with  solution 
<'f  mauganons  sulfate,  or  lead  hydroxid,  or  palladium  chlorid  is  col- 
ored dark  brown  or  black  by  ozone.  C.  Metallic  silver' is  blackened 
h  ozone. 

When  inhaled*  air  containing  0.07  gram  of  ozone  per  litre  causes 
intense  eoryza  and  haemoptysis.  It  is  probable  that  ozone  is  by  no 
ni^Mi*  as  constant  a  constituent  of  the  atmosphere  as  was  formerly 
«nppofted.     (See  Hydrogen  difixidj 


COMPOUNDS  OF  HYDROGEN  AND  OXYGEN. 

T^o  are  known— hydrogen  oxid  or  water,  H2O  i  hydrogen  peroxid 
or  oiygenated  water,  H2O2. 

WATER. 

E^—Molemlar  weighf=lS  8p.  gt\=l— Vapor  density =0.B21S  Aj 

^kHtaUd='0. 6234— fhnifumtion  dheovered  by  PrhstUy  in  1780 — 1  c€. 
v^hhs  1  irm.  tff  4"^  and  0.999  gm,  (tt  16""— 1  eithiv  inch  weighs  252.6 
Smm  at  eO*"  F. 

Occurrence. — In  unorganized  nature  HoO  exists  in  the  gaj^eons 
form  in  atraospherie  air  and  in  volcanic  gases;  in  the  liquid  fonn 
Ten  abundantly;   and  as  a  solid  in  snow,  ice,  and  hail. 

As  water  of  crystallization  it  exists  iu  definite  proportions  in  eer- 
Itta  ei^BtalB,  to  the  maintenance  of  whose  shape  it  is  necessary. 


114  MANUAL    OP    CHEMISTRY 

In  the  organized  world  H2O  forms  a  constituent  part  of  every 
tissue  and  fluid. 

Formation. — Water  is  formed:  1.  By  union,  brought  about  by 
elevation  of  temperature,  of  one  vol.  0  with  two  vols.  H. 

2.  By  burning  H,  or  substances  containing  it,  in  air  or  in  0. 

3.  By  heating  organic  substances  containing  H  to  redness  with 
cupric  oxid,  or  with  other  substances  capable  of  yielding  O.  This 
method  of  formation  is  utilized  to  determine  the  amount  of  H  con- 
tained in  organic  substances. 

4.  When  an  acid  and  a  hydroxid  react  upon  each  other  to  form  a 
salt: 

H2SO4  +  2KH0  =  K2SO4  +  2M,0 

Sulforie  acid.  Potassium  hydroxid.  Potassium  sulfate.  Water. 

5.  When  a  metallic  oxid  is  reduced  by  hydrogen: 


CiiO        +        H2 

= 

Cu 

4- 

H2O 

Cupric  oxid.          Hydrogen. 

Copper. 

Water. 

6.  In  the  reduction  and  oxidation  of  many  organic  substances. 

Pure  H2O  is  not  found  in  nature.  When  required  free  from 
ordinary  impurities  it  is  separated  from  suspended  matters  by  filtra- 
tion, and  from  dissolved  substances  by  distillation. 

Properties. — Physical. — With  a  barometric  pressure  of  760  mm. 
H2O  is  solid  below  0''  (32°  F.) ;  liquid  between  0°  (32°  P.)  and  100° 
(212°  P.) ;  and  gaseous  above  100°  (212°  P.).  When  H2O  is  enclosed 
in  capillary  tubes,  or  is  at  complete  rest,  it  may  be  cooled  to  — 15° 
(5°  P.)  without  solidifying.  If,  while  at  this  temperature,  it  be 
agitated,  it  solidifies  instantly,  and  the  temperature  suddenly  rises  to 
0°  (32°  P.).  The  melting-point  of  ice  is  lowered  0.0075°  (0.0135° 
P.)  for  each  additional  atmosphere  of  pressure. 

The  boiling-point  is  subject  to  greater  variations  than  the  freezing- 
point.  It  is  the  lower  as  the  pressure  is  diminished,  and  the  higher  as 
it  is  increased.  Advantage  is  taken  of  the  reduced  boiling-point  of 
solutions  in  vacuo  for  the  separation  of  substances,  such  as  cane 
sugar,  which  are  injured  at  the  temperature  of  boiling  H2O.  On  the 
other  hand,  the  increased  temperature  that  may  be  imparted  to  liquid 
H2O  under  pressure  is  utilized  in  many  processes  in  the  laboratory  and 
in  the  arts,  for  effecting  solutions  and  chemical  actions  which  do  not 
take  place  at  lower  temperatures.  The  boiling-point  of  H2O  holding 
solid  matter  in  solution  is  higher  than  that  of  pure  H2O,  the  degree 
of  increase  depending  upon  the  amount  and  nature  of  the  substance 
dissolved.  On  the  other  hand,  mixtures  of  H2O  with  liquids  of  lower 
boiling-point  boil  at  temperatures  less  than  100°  (212°  P.).  Although 
the  conversion  of  water  into  water -vapor  takes  place  most  actively  at 
100°  (212°  P.),  water  and  ice  evaporate  at  all  temperatures. 


WATER 


115 


Water  is  the  best  solvent  we  have,  and  aets  in  some  instances  as 
8  giniple  solvent,  in  others  as  a  ohemiiial  solvent. 

Vapor  of  water  is  colorless,  transparent,  and  invisible.  Sp,  gr. 
0.62^54  A  or  9  H.  A  litre  of  vapor  of  water  weighs  0.8064.  The 
latent  heat  of  vaporization  of  wat'-r  is  536.5-,  that  is^  as  ninch  heat 
is  required  to  vaporize  1  kilo,  of  water  at  100''  as  would  suffice  to 
raise  536*5  kilos,  of  water  1^  in  temperature.  In  passing  from  the 
liquid  to  the  gaseous  state*  water  expands  1,696  times  in  volume, 

CA^mi'm/,-^ Water  may  be  shown  to  consist  of  1  voL  O  and  2 
Toig,  H,  or  8  by  weight  of  O  and  1  by  weight  of  H,  either  by 
inaJysis  or  synthesis. 

Analysis  is  the  reducing  of  a  compound  to  its  constituent 
parts  or  elements. 

Synthesis  is  the  formation  of  a  compound  from  its  elements. 
Anarfial  synthesis  is  one  in  which  a  complex  eompound  is  produced 
fmiii  a  simpler  one,  but  not  from  the  elements. 

Water  may  be  resolved  into  its  constituent  gases;  1.  By  elee- 
txvlym  of  acidulated  water;  H  being  given  off  at  the  negative  and 
0  at  the  positive  pole.  2.  By  passiut;  vapor  of  H2O  through  a 
plitintim  tube  heated  to  whiteness,  or  through  a  porcelain  tube 
heated  to  about  1,100°.  The  dccom|>ositiou  of  a  compound  gas  or 
tEpar  by  elevation  of  temperature  is  flailed  dissociation,  3.  By  the 
•ction  of  the  alkali  nietals.  Hydrogen  is  given  off.  and  the  metallic 
hydrnxid  remains  in  solution  in  an  excess  of  FLiO.  4.  By  passing 
viipor  of  H2O  over  red-hot  iron.  Oxid  of  iron  remains  and  11  is 
given  off. 

Water  combines  with  oxids  to  form  new  eomponnds*  some  of 
whifh  are  aeids  and  others  bases,  known  as  hydroxids. 

A  hydroxid  is  a  compound  formed  by  the  replacement  of  half 
of  the  hydrogen  of  water  by  another  element  or  by  a  radicah 

A  hydrate  is  a  compound  containing  chemically  combined 
w*tcr.  The  aet  of  union  of  a  substance  with  water  is  referred  to  as 
hydration. 

Tbi*  hydroxids  of  the  electro* negative  elements  and  radicals  arc 
acids;  most  of  those  of  the  electro -positive  elements  and  radicals 
liW'  basic  hydroxids. 

Certain  substances,  in  crystallizing,  combine  with  a  definite  pro- 
portion of  water,  which  is  known  as  water  of  crystallization,  and 
whose  presenee,  although  necessary  to  the  maintenance  of  ccrtiiin 
pt^ical  characters,  such  as  color  and  erystalline  form,  does  not 
roodify  their  chemical  reactions.  In  many  instances  a  portion  of  the 
w*ter  of  cryi^tallization  may  be  driven  off  at  a  comparatively  low 
rrm[)cmtnre,  while  a  higher  temperature  is  required  to  expel  the 
remainder.     This  latter  is  known  as  i«rater  of  constitution. 


116 


MANUAL    OF    CHEMISTKY 


The  eymbol  Aq  (Latin,  aqua)  is  frequently  used  to  designate  the 
water  of  crystallization,  the  water  of  constitution  beingr  indicated  by 
H2O.  Thus  MgSOi,  HsO+BAq  represents  nmgnesiom  sulfate  with 
one  molecule  of  water  of  constitution  and  six  molecules  of  water  of 
crj'sialiization .  We  consider  it  preferable,  however^  as  the  distinc- 
tion between  water  of  crystallization  and  water  of  constitution  in 
many  salts  is  only  one  of  degree  and  not  of  kind,  to  use  the  symbol 
Aq  to  designate  the  sum  of  the  two-   thus,  MgSOi+TAq. 

Water  decomposes  the  ehlorids  of  the  second  class  of  elements 
(those  of  carbon  only  at  high  temperatures  and  under  pressure). 
Thus  phosphorous  triehlorid  forms  phosphorous  and  hydrochloric 
acids  t  PCI3  +  3H2O  =  H3PO3  +  3HCK  A  decomposition  attended 
with  absorption  of  water  is  called  hydrolysis ► 

Natural  Waters* — Natural  waters  which  appear  to  the  sens^es  to 
be  fit  for  drhiking  are  called  potable  waters,  in  contradistinction 
to  such  as  are,  from  their  taste  and  appearance,  obviously  unfit  for 
that   use. 

Potable  waters  may  be  classified,  according  to  their  origin,  into 
four  groups  : 

Meteoric  waters :  rain  water  and  melted  snow.  These  ai"e  the 
purest  natural  waters  if  uncontaminated  ]  they  contain  very  small 
quantities  of  solids,  and  are  highly  aerated.  Rain  water  falling 
duriTig  the  first  part  of  a  shower  is  less  pure  than  that  which  falls 
subsequently.  In  districts  where  notable  quantities  of  coal  which 
contains  sulfur  are  burnt,  rain  water  contains  more  sulfates,  ammo* 
uiacal  salts,  nitrates  and  nitrites  than  elsewhere. 

Surface  waters :  the  waters  of  rivers,  lakes  and  ponds.  These 
are  mixtures,  in  varying  proportions,  of  rain  water,  spring  water 
and  the  drainage  of  the  surrounding  land.  They  vary  greatly  in 
natural  purity,  and  are  frequently  contaminated  by  sewage  and 
other  refuse* 

Ground  waters :  water  which  permeates  the  superficial  strtitnm 
aliove  the  uppermost  impermeable  rock*  This  is  the  water  obtained 
in  suiface  wells  and  in  driven  wells.  Its  quality  depends  upon  %vhat 
is  in  and  on  the  stratum  in  which  the  well  is  dug;  a  driven  well  in  a 
sandy  stratum  remote  from  habitations  yields  an  excellent  water, 
while  the  water  of  a  well  near  a  privy  vault  or  a  defective  sewer  is 
more  or  less  diluted  sewage.  In  limestone  districts  ground  water  is 
hard.  — 

Deep  waters :  spring  waters  and  those  of  artesian  wells.        ^ 

Spn'ttg  wfifer  is  rain  water  which,  having  percolated  through  a 
portion  of  the  earth's  crust  (in  which  it  may  also  have  been  subjected 
to  pressure),  has  become  charged  with  solid  and  gaseous  matter, 
varying  in  kind  and  quantity  according  to  the  nature  of  the  strata 


WATER 


117 


> 


through  which  it  has  percolated,  the  duration  of  contact,  and  the 
pressure  to  which  it  was  subje^H  during  such  contact. 

Spring  waters  from  igneous  roi*ks  and  from  the  older  sedimentary 
formatious  are  fresh  and  sweet,  and  any  spring  water  may  be  eonsid* 
en-d  such  who5;e  temperature  is  less  than  20*^  {68^  FJ,  and  wiiiefi 
does  not  euutaiu  more  than  40  parts  in  100,00(J  of  solid  matter;  pro- 
vided that  a  large  proportion  of  the  solid  matter  does  not  consist  of 
•Its  having  a  URidlcinal  action »  and  that  sulfurous  gases  and  sulfide 
'in  absent. 

Artesian  wells  are  artificial  springs,  produced  by  boring  in  a  low- 
lyiflg  district,  until  a  pervious  layer,  between  two  impervions  strata, 
isttfaehed;  t!ie  uuterop  of  the  system  being  in  an  adjacent  elevated 
region. 

Impurities  in  Potable  Waters, — A  water  to  be  fit  for  dinnking 
PQr|K>ses  should  beeool,  limpid  mid  odorless;  it  should  have  an  agree- 
tWe  taste,  iieitlier  flat,  salty,  nor  sweetish,  and  it  should  dissolve 
•Ottp  readily,  wit  lion  t  formation  of  any  Hoceulent  precipitate  But, 
while  it  is  safe  to  condemn  a  water  w^hich  does  not  possess  the  above 
irs,  it  is  by  no  ujeans  safe  to  regard  all  waters  which  do 
them  as  beyond  suspicion.  The  must  dangerous  of  all  con- 
taminations of  drinking  waters  is  by  admixture  of  sewage,  which 
maybe  present  in  a  water  in  quantity  sufficient  to  lender  it  unfit  for 
nse  and  the  water  yet  retain  all  of  tlie  eliaiactcrs  of  a  good  water 
above  refen-ed  to.  To  determine  whether  a  water  is  really  fit  for 
driukmg  a  chemical  analysis  is  neeessury,  and  a  bacteriological  exansi- 
wation  is  desirable.  For  the  methods  of  chemieu!  analysis  the  student 
ill  referred  to  treatises  on  that  subject.  The  constituents  usually 
fclermiued,  and  the  interpretation  of  the  results,  are  as  follows: 

Total  Solidst — The  amount  of  solid  material  dissolved  in  potable 
waters  varies  from  4.3  to  M  in  1W,000  (2.5  to  29,2  grains  per  IT,  S. 
|tl);  and  a  water  containing  more  than  the  latter  quantity  is  to  be 
i'ondemned  on  that  account  alone. 

Chlorlds. — The  presence  of  the  ehlortds  of  the  alkaline  metals,  in 
Viantitics  not  suflBeient  to  be  detectable  by  the  taste,  is  of  no  irn- 
pwtanee  j^r  *^ ;  but  in  connection  w^ith  the  prescience  of  organic  im- 
pwity,  a  determination  of  the  amount  of  chlorin  affords  a  ready 
tti^thod  of  indicating  the  probable  source  of  the  organic  eontaniioa- 
l*oa.  As  vegetable  organic  nuitter  brings  with  it  but  small  quantitica 
^Ichloridfi,  while  animal  contami nations  are  rich  in  those  compouuds, 
Ite  nr(;sence  of  a  large  amount  of  chlorin  serves  to  indicate  that 
organic  impurity  is  of  animal  origin.  Indeed,  when  time  pi*esses,  aa 
^riijg  an  epidemic,  it  is  best  to  rely  upon  determinations  of  chlorin, 
aod  condemn  all  waters  containing  more  than  1.7  in  100,000  (1  grain 
pei"  l\  S,  gal.)  of  that  element. 


118  MANUAL    OP    CHEMISTRY 

Hardness. — The  greater  part  of  the  solid  matter  dissolved  in 
natural  fresh  waters  consists  of  the  salts  of  calcium,  accompanied  by- 
less  quantities  of  the  salts  of  magnesium.  The  calcium  salt  is 
usually  the  bicarbonate  or  the  sulfate;  sometimes  the  chlorid,  phos- 
phate, or  nitrate. 

A  water  containing  an  excess  of  calcareous  salt  is  said  to  be 
hard,  and  one  not  so  charged  is  said  to  be  soft.  If  the  hardness  be 
due  to  the  presence  of  the  bicarbonate  it  is  temporary,  if  due  to  the 
sulfate  it  is  permanent.  Calcium  carbonate  is  almost  insoluble  in 
pure  water,  but  in  the  presence  of  free  carbonic  acid  the  more  sol- 
uble bicarbonate  is  dissolved.  But,  on  the  water  being  boiled,  it  is 
decomposed,  with  precipitation  of  the  carbonate.  As  calcium  sul- 
fate is  held  in  solution  by  virtue  of  its  own,  albeit  sparing,  solu- 
bility, it  is  not  deposited  when  the  water  is  boiled. 

The  hardness  is  now  usually  reported  in  terms  of  calcium  car- 
bonate, CaCOa,  either  in  grains  per  gallon  or  parts  in  100,000.  It 
is  also  sometimes  reported  in  "degrees,"  which  represent  grains  of 
CaCOa  per  imperial  gallon.  Very  soft  waters  contain  about  SCaCOa 
in  100,000,  and  hard  waters  15  or  over.  Usually  a  water  containing 
more  than  20CaCO3  in  100,000  is  considered  too  hard  for  domestic 
use,  unless  softened  by  boiling.  But  a  water  is  not  to  be  con- 
demned solely  because  its  hardness  exceeds  this  limit,  because  in 
certain  limestone  districts  all  waters  are  very  hard. 

Waters  which  owe  their  hardness  to  excess  of  magnesium  salts, 
cause  intestinal  disturbances  in  those  not  habituated  to  them. 

Organic  Matter. — Technically,  organic  impurities  in  a  water  con- 
sist of  vegetable  or  animal  matters  containing  nitrogen.  We  have 
seen  that  the  quantity  of  chlorin  affords  an  indication  as  to  whether 
the  organic  impurity  found  to  be  present  is  of  vegetable  or  of  animal 
origin.  Animal  organic  contamination  has  its  origin  in  sewage,  and 
its  presence  consequently  indicates  that  the  water  is,  or  may  at  any 
moment  become,  the  means  of  transmitting  water-borne  diseases, 
such  as  typhoid  and  cholera. 

The  nitrogenous  substances  in  feces  and  urine  consist  of  albumi- 
nous bodies,  cr>'stalline  organic  compounds  (such  as-  urea,  leucin, 
etc.)  and  ammoniacal  salts.  By  the  action  of  micro-organisms, 
which  exist  in  the  soil  and  in  water,  the  albuminous  and  crj'stalline 
compounds  are  gradually  converted  into  ammonium  compounds, 
which  are  subsequently  oxidized  by  atmospheric  or  dissolved  oxygen, 
aided  by  bacterial  influence,  to  nitrites  and  later  to  nitrates.  Conse- 
quently the  amount  of  sewage  contamination,  and  the  degree  in  which 
such  contamination  has  been  subsequently  modified,  can  be  inferred 
from  quantitative  determinations  of  the  nitrogen  present  in  the  sev- 
eral forms  referred  to. 


WATER 


119 


In  the  usual  process  of  water  aualysis  the  following  factors  are 
deteriniDed  quantitatively: 

A.  Albuminoid  ammonia,  which  represents  the  nitrogen  present 
in  albuminous  and  crystalline  combinatioo, 

B.  Free  ammonia,  which  represents  the  araraoniacal  compounds. 

C.  Nitrogen  in  nitrates  and  nitrites »  and  D.  Nitrites. 

II  a  water  yield  no  albuminoid  limmouia  it  is  organically  pure, 
«ven  if  it  contain  much  free  annnouiu  and  eh  lor  ids*  If  it  contain 
from  .02  to  .05  milligrams  per  litre  (.002  to  ,005  in  100,000)  it  is 
still  quite  pure.  When  the  albuminoid  ammonia  reaches  0.1  railligr. 
p«r  litre  (.01  in  100,000)  the  water  is  to  be  looked  upon  with  sus- 
picion; and  it  is  to  be  condemned  when  the  proportion  reaches  0.15 
(.015  in  100,000).  When  free  ammonia  is  also  present  in  consid- 
erable quantity,  a  water  yielding  0.05  (.005  in  100,000)  of  albumi* 
lioid  ammonia  is  to  be  looked  upon  with  snspieion. 

Nitrates  and  nitrites  are  present  in  rain  water  in  quantities  less 
thau  0.5  parts  in  100,tX)0,  calenhited  as  nitrogen.  When  the  amount 
exceeds  this,  these  salts  are  considered  as  indicating  previous  con- 
tamination  by  organic  matter  which  has  been  oxidized  and  whose 
iiitro^n  has  been  to  some  extent  converted  into  nitrites  and  nitrates. 

The  quantity  of  nitrites  in  good  waters  does  not  exceed  .002  in 
100,000  when  they  are  present.  A  larger  quantity  is  considered  as 
iudicatiug  previous  organic  contaminatit»:  . 

In  some  processes  it  is  sought  to  measure  the  organic  contiimina* 
tion  by  the  amount  of  oxygen  consumed  in  their  oxidation  by  po- 
tessinm  permanganate.  As  these  results  take  no  account  of  other 
otidations  which  may  take  place  they  are  not  reliable. 

Poisonous  Metals,  —  Natural  waters  containing  notable  quan- 
tities of  iron  compounds  belong  to  the  class  of  chalybeate  mineral 
T^^Aters.  Contact  with  metallic  iron  does  not  contaminate  water.  In 
totricts  where  copper  deposits  exist  the  waters  sometimes  contain 
copper,  and  the  waters  of  some  streams  contain  arsenic. 

Lead  in  drinking  water  has  been  a  prolific  source  of  chronic  lead 
»isoniag.  As  lead  is  only  dissolved  by  water  after  oxidation,  con- 
ditions favoring  oxidation  of  the  metal  favor  its  solution.  Such 
^fiditions  are:  the  presence  of  nitrates,  a  highly  aerated  condition 
«t  the  water,  alternate  wetting  and  drying  of  the  surface  of  the  metal, 
the  absence  of  sulfates  and  carbonates,  and  the  presence  of  much 
^bonic  acid  dissolved  under  pressure  (soda  water).  8ulfates  and 
Wbcmates  prevent  solution  by  the  format  ion  of  a  protecting  coating 
^' an  insoluble  salt.  As  a  rule,  the  purer  the  water  the  more  liable 
*t  is  to  dissolve  lead  when  brought  in  contact  with  that  raetat,  espe- 
titlly  if  the  contact  occur  when  the  water  is  at  a  high  temperature, 
<Jrwhen  it  lasts  for  a  long  period. 


taw 

■901 


J20 


MANUAL    OF    CUEMISTEY 


Bacteriological  Examination  of  Water.— lu  recent  years  mucb 
attention  has  been  given  to  the  examination  of  natural  waters  b3" 
bacteriological  methods,  plate  cultures  on  gelatin,  cultures  in  blood 
serum  and  on  potatoes,  and  experiments  on  animals.  Although  in 
some  instances  pathogenic  bacteria  ha%^e  been  found  in  water,  and 
although  in  the  future  valuable  results  will  probably  be  obtained  by 
these  methods,  the  chief  reliance  in  determining  the  quality  of  a 
drinking-water  is  still  to  be  placed  upon  the  older  chemical  processes. 

Purification  of  Water, — The  artificial  means  of  rt-ndcring  a  raore 
or  less  contaminated  water  tit  fc^r  use  are  of  five  kinds:  Distillation, 
subsidence^  filtration,  precipitation,  and  boiling. 

Distillation  is  resorted  to  in  the  laboratory  to  obtain  very  pure 
water,  also,  on  a  larger  scale,  to  purify  driuking  water.  When  dU- 
tilled  water  is  to  be  used  for  drinkiug  it  should  be  aerated  and  chai-ged 
with  salts  to  the  extent  of  about  0.03  gram  each  of  calcium  bicarbo- 
nate and  sodium  chlorid  to  the  litre. 

In  filtration  suspended  impurities  are  removed  more  or  less  com- 
pletely by  passing  the  water  through  a  porous  material.  In  filter 
beds,  used  to  filter  large  quantities  of  water,  sand  is  the  filtering 
loaterial  used,  either  alone  or  eominned  with  charcoal  or  spongy  iron. 
In  domestic  filters,  treating  small  quantities  of  water,  the  filtering 
material  is  quartz  sand,  charcoal,  porous  stone,  or  uuglazed  earthen- 
ware or  porcelain.  Whatever  may  be  the  size  or  construction  of  the 
filter,  it  nmst  be  cleaned  periodically.  If  this  be  neglected  the  tiiter 
ceases  to  purify  the  water^  and  becomes  itself  a  source  of  contamina- 
tion. The  usual  method  of  cleaning  is  by  reversing  the  current 
through  the  filter  until  the  washings  come  away  clear.  Dissolved 
organic  matter  is  in  part  removed  by  oxidation  io  filtration  through 
sand  filter  beds  several  feet  in  thickness,  or  through  much  thinner 
layers  of  charcoal  or  porous  iron.  Typhoid  and  cholera  germs  pass^ 
although  in  greatlv  diminished  numbers,  through  all  filters  excepj 
tliose  made  of  uuglazed  porcelain. 

Precipitation  methods  were  formerly  used  only  to  soften  tenipor 
artly  hard  waters.  One  method  consists  in  the  addition  of  lime  water 
in  quantity  ju,st  sufficient  to  convert  the  soluble  calcium  bicarbonate 
present  into  the  insoluble  carbonate.  At  present  precipitation 
methods  are  also  used,  in  combination  with  subsidence  and  filtration, 
to  remove  organic  iuipurities  ;  alum  or  a  ferric  salt  is  udded,  an 
excess  being  avoided,  to  form  a  gelatinous  precipitate  which  caiTies 
the  impurities  down  with  it  mechanically  as  it  settles  when  the  water 
is  left  at  rest  in  the  subsidence  tanks;  the  water  is  drawn  off  from 
above  the  deposit  to  the  filters,  after  a  proper  interval.  Precipitation 
and  subsidence  are  thus  used  to  diminish  the  work  reqnii*ed  of  the 
filters. 


I 


WATER 


121 


rai: 

re 
pel 
to 


The  purification  of  water  by  boilings  can  only  be  carried  on  on  a 
small  scale.  It  is  very  useful,  however,  to  soften  temporarily  bard 
watefis  Hod,  particularly,  to  sterilize  infected  waters.  Fur  tlie  latter 
pnriwse  the  boiling  must  be  continued  actively  for  at  least  twenty 
aiiimtes  in  a  vessel  closed  except  for  a  steam  outlet,  which  is  to  be 
Slopped  with  a  plug  of  cotton  when  the  vessel  is  taken  off  to  cooK 

Natural  Purification  of  Water. —The  water  of  brookgi,  riverbi, 
and  lakes  which  have  been  contatuinated  by  sewage  and  other  organic 
inipurity  becomes  gradually  puritied  by  natural  processes.  Sus- 
pended particles  are  deposited  upon  the  bottom  and  sides  of  the 
stream,  more  or  less  rapidly,  according  to  their  gravity  and  the 
rapidity  of  the  current.  The  bicarbonatea  of  calcium,  magnesium » 
id  iron  gradually  lo^e  carbon  dioxid,  and  are  precipitated  as  car- 

uates,  which  mecbanicaliy  carry  down  dissolved  as  well  as  sus- 
pended impurities.  The  decompositions,  oxidations,  and  reductions 
to  which  organic  matters  are  subject  under  the  iufluence  of  atraos- 
plierie  and  dissolved  oxygen  and  bacterial  action  bring  about  their 
gradual  mineralization  by  conversion  into  ammonia  and  then  into 
nitrate^*  The  processes  of  nutrition  of  aquatic  plant  life  absorb 
dissolved  organic  inipurity,  as  well  as  the  products  of  decomposition 
of  nitrogenized  substances.  This  natural  purification  proceeds  the 
more  rapidly  the  more  contact  with  air  is  favored. 

Mineral  Waters* — Under  this  bead  are  classed  all  waters  which 
ai^  of  therapeutic  or  industrial  value,  by  reason  of  the  quantity  or 
nature  of  the  dissolved  solids  which  they  contain;  or  which  have  a 
temperature  greater  than  20°  (68°  F.). 

The  composition  of  mineral  watei's  varies  greatly,  according  to  the 
nature  of  the  strata  or  veins  through  which  the  water  passes,  and  to 
tht»  conditions  of  pressure  and  previous  composition  under  which  it  is 
*n  contact  with  these  deposits. 

Although  a  sharply  defined  classification  of  mineral  waters  is  not 
;io3»ible,  one  which  is  nsefuli  if  not  accurate,  may  be  made,  based 
'i|K»u  the  predominance  of  some  constituent,  or  constituents,  which 
^Jnpart  to  the  water  a  w^ell -defined  therapeutic  value.  A  classifica- 
tinn  which  has  been  generally  adopted  includes  five  classes: 

h  Aciiluloua  waters ;  whose  value  depends  upon  dissolved  ear- 
^»Qic  acid.  They  contain  but  small  quantities  of  solids,  principally 
the  biearbonates  of  sodium  and  calciniu  and  sodium  chlorid. 

lb  Alkaline  tmters  ;  which  contain  quantities  of  the  bicarbonates 
ff  sodium,  potassium,  lithium,  and  calcium,  sufficient  to  comranni- 
cftte  to  them  an  alkaline  reaction,  and  frequently  a  soapy  taste  ; 
either  naturally,  or  after  expulsion  of  carbon  dioxid  by  boilings 

III.  Chaitfhiate  waters  ;  which  contain  salts  of  iron  in  greater 
Pfn[»f»rtion   than  4  parts   in   100,000.     They  contain    ferrous   bicar- 


122 


MANUAL    OF    CHEMISTRY 


bonate,  sulfate,  crenate,  and  apocreuate,  calcium  carbonate,  sulfatea 
of  potassiuTu,  sodium,  calcium,  ma^esium,  and  alumiuinin,  notable 
quantities  of  sodium  cblorid,  and  frequently  small  amoubts  of 
arsenic.  They  have  the  taste  of  iron  and  are  usually  t'lear  n^  tiiey 
emerge  from  the  earth.  Those  containing  ferrous  bicarbonate  de* 
posit  a  sediment  on  standing,  by  loss  of  carbon  dioxid,  and  formatioa^ 
of  ferrou8  carbonate.  ^M 

IV.  SaHne  imters ;  which  contain  nentral  salts  in  considerable 
quantity.  The  nature  of  the  salts  which  they  contain  is  so  diverse 
that  the  group  may  well  be  subdivided :  ^M 

a^  CMorin  waters ;  which  contain  large  quantities  of  sodium 
cblorid,  accompanied  by  less  amounts  of  the  chlorids  of  potassium, 
calcium,  and  magnesium.  8ome  are  so  rich  in  sodium  cblorid  that 
they  are  not  of  service  as  therapeutic  agents,  but  are  evaporated  to 
yield  a  more  or  less  pure  salt.  Any  natural  water  containing  more 
than  W}  parts  in  100,00(J  of  sodinni  ehlorid  belongs  to  this  class, 
provided  it  do  not  contain  substances  more  active  in  their  medicinal 
action  in  such  proportion  as  to  warrant  its  classification  eJsewhere* 
Waters  containing  more  than  l,5tX)  parts  in  100,000  are  too  concen- 
trated for  internal  admiuistration, 

fi*  Sulfate  Witters  arc  actively  purgative  from  the  presence  of 
considerable  proportions  of  the  sulfates  of  sodium,  calcium,  and 
magnesium.  Some  contain  large  quantities  of  sodium  sulfate,  with 
mere  traces  of  the  calcium  and  magneeinni  salts*  while  in  others  the 
proportion  of  the  sulfates  of  magnesium  and  calcium  is  as  high  as 
3,000  parts  in  100,000  to  *J,OfH}  parts  in  100,000  of  sodium  sulfate. 
They  vary  much  in  concentration;  from  5<X)  to  nearly  6,000  parts  of 
total  solids  in  100,000.  They  have  a  salty,  bitter  taste,  and  vary^ 
much  in  temperature.  H 

y.  Bromin  and  iodin  waters  are  such  as  contain  the  bromids  or 
iodids  of  potassium,  sodium,  or  magnesium  in  sufficient  quantity  to 
communicate  to  them  the  medicinal  properties  of  those  salts. 

V.  Sidfurous  water,'^;  which  hold  hydrogen  sulfid  or  metallic 
sulfids  in  solution.  They  have  a  disagreeable  odor  and  are  usually 
warm.     They  contain  20  to  4(X)  parts  in  100,000  of  total  solids.       fl 

PhysiologicaL— Water  is  taken  into  the  body  both  as  a  liquid 
and  as  a  constituent  of  every  article  of  food;  the  amount  ingesttd 
by  a  healthy  adult  being  2.25  to  2.75  litres  {2%  to  3  quarts)  per 
diem.  The  greater  the  elimination  and  the  drier  the  natni'e  of  the 
food  the  greater  is  the  amount  of  H^O  taken  in  tlie  liquid  form. 

Water  is  a  constituent  of  every  tissue  and  tlnid  of  the  body,  vary- 
ing  from  0.2  per  cent,  in  the  enamel  of  the  teeth  to  99.5  per  cent,  iu 
the  perspiration  and  saliva.  It  constitutes  about  60  per  cent*  of  the 
weight  of  tbe  i>ody. 


HYDliOGEX    DIOXID 


123 


The  consistency  of  the  vHrious  parts  does  not  depend  entirely  upon 
the  relative  proportion  of  solids  and  H-iO,  hui  is  iriflueueed  by  the 
nature  of  the  solids.  The  blood,  althouijh  liquid  in  the  ordinary  sense 
of  the  terra,  contains  a  less  proportional  amount  of  H2O  than  does  the 
tissne  of  the  kidneys,  and  al>out  Ihe  same  pn>pf>rtion  as  the  tissue  of 
the  heart.  Although  the  bile  and  mucus  are  not  as  rtoiil  as  I  lie  bl*uul, 
they  contain  a  larger  proportion  of  H2O  to  solids  than  does  that  liquid. 
Water  is  discharged  by  the  kidneys,  intestines,  skin,  and  jndmo- 

nary  surfaces.     The  quantity  dischari^ed  is  |^reat**r  than  tbat  ingested; 

the  excess  being  formed  in  the  body  by  the  oxidalinn  of  I  lie  H  of  its 

organic  ^constituents. 


h 


HYDROGEN   DIOXID. 

HYDHOaEN     PEKOXID — OXYGENATED    WATER. 

1 ,455  —  Dhvovered  htj 


Kh  —  Molecular  weight  =  34 — Sp,  gi\ 

Wmml  in   1818. 

Exists  naturally  in  very  minute  quantity  in  rain-water,  in  air,  and 
in  the  saliva. 

This  snbstiince  may  be  obtained  in  a  state  of  purity  by  accurately 
fi'llowing  the  process  of  Thenard,  It  may  also  be  obtained,  mixed 
witli  a  large  quantity  of  11 2O,  by  the  action  of  dilute  mineral  acids  on 
barium  peroxid:  Ba02+ll-j804  =  BaSO^  +  H2O2.  It  is  also  formed 
in  j^mall  quantity  during  the  slow  oxidation  of  many  elements  and 
compounds,  such  as  1\  Pb,  Zn,  Cd,  Al,  alcohol,  ether  and  the  essences. 

It  ig  prepared  industrially  of  10-12  volume  streugfth  by  gradually 
lidding  barium  peroxid  to  dilute  hydrofluoric  acid  solntion,  the  mix- 
ture being  maintained  at  a  low  temperature  and  constantly  agitated; 
*»r»  in  still  greater  concentration  by  the  action  of  dilute  acids  on 
**oditim  peroxid,  care  being  had  to  prevent  heating  of  the  mixture: 
Na20s  +  2HCl=2NaCl+H2O3.  Hydrogen  peroxid  is  also  formed 
Hen  sodium  peroxid  is  dissolved  in  water:  Na202+2H20— 2NaHO 

The  pure  substance  is  a  colorless,  syrupy  liquid,  which,  when 
P^^nrt'd  into  H.iO,  sinks  under  it  before  mixing*  It  has  a  disagreeable 
^^tallic  taste,  somewhat  resembling  that  of  tartar  emetic.  When 
^ken  into  the  mouth  it  produces  a  tingling  sensation,  increases  the 
^^  (it  saliva,  and  bleaches  the  tissues  with  which  it  comes  in  eon- 
M,  It  is  still  liquid  at— 30*"  (—22°  F.).  It  is  very  unstable,  and, 
^^^n  ill  darkness  and  at  ordinary  temperature,  is  gradually  decom- 
P<>M,  At  20°  (68°  F.)  the  decomposition  takes  place  more  quickly 
t»J  nt  100^  (212^  PJ  rapidly  and  with  effervescence.  The  dilute 
^oWjtnce,  however,  is  comparatively  stable,  and  may  be  boiled  and 
«^€ii  distilled  without  suffering  decomposition.     Yet  it  is  liable  to 


MANUAL    OF    CHEMISTRY 


explosive  decomposition  when  exposed   to  summer   temperature   m 
closed  vessels.  ,    ,.| 

Hydrngeti  peroxid  acts  both  as  a  reducing  and  an  oxidizing  ageot,* 
Arsenic,  sulflds,  and  snlfiir  dioxid  are  oxidized  by  it  at  the  e^pens^r 
of  half  its  oxygen.  When  it  i&  brought  in  contact  with  silver  oxid 
both  substances  ai*e  violently  de(?omposed,  water  and  elementary 
silver  iH^niaiuing.  By  cprtaiu  substanees,  such  as  gold,  platinnni^ 
and  charcoal  in  a  state  of  fine  division,  fibrin,  or  manganese  dioxid, 
it  is  decomposed  with  evolution  of  oxygen;  the  deeomposiiig  agent 
remaining  unchanged. 

The  pore  substance,  when  decomposed,  yields  47*1  times  its  vol- 
ume of  oxygen;    the  dilute  15  to  20  volumes. 

In  dilute  solution  it  is  used  as  a  bleaching  agent  and  in  the  reno- 
vation of  old  oil-paintings.  It  is  an  energetic  disinfectant  and  anti- 
septic, and  is  extensively  used  in  surgery.  "Ozonic  ether"  is  a  mix- 
ture of  et hylic  ether  and  dilute  hydrogen  peroxid. 

Analytical  Characters.  —  1.  To  a  solution  of  starch  a  few  drops 
of  cadmium  iodid  solution  are  added,  then  a  amali  quantity  of  the 
fluid  to  be  tested,  aud,  fiually,  a  drop  of  a  sohition  of  ferrous  sul- 
fate. A  blue  color  is  produced  in  the  i»resence  of  hydrogen  peroxid, 
even  if  the  solution  contain  only  0.05  milligram  per  litre. 

2.  Add  freshly -prepared  tincture  of  guaiaeura  and  a  few  drops  of 
a  cold  infusion  of  malt.     A  blue  color  — 1  in  2,000,000. 

3.  Add  to  the  liriuid  a  few  flrops  of  potassium  dichromate  and 
a  little  dilute  sulfuric  acid,  atid  agitate  with  ether.  The  ether 
assumes  a  brilliant  blue -violet  color. 

4.  Add  to  6  cc.  of  the  liquid  sulfuric  acid*  iodid  of  zinc,  starch- 
paste,  two  drops  of  a  2  per  cent,  solution  of  eupric  sulfate,  and  a 
little  one-half  per  cent,  solution  of  ferrous  sulfate,  in  the  order 
named.     A  blue  color. 

5.  Add  a  trace  of  acetic  acid,  some  ^  naphthylamiu  and  solid 
sodium  chlorid.  After  a  short  time  a  blue  or  blue- violet  color,  and 
after  some  hours  a  floeeulent  ppt.  of  the  same  color. 

Atmospheric  Hydrogen  Dioxid**— It  has  been  claimed  that 
atmospheric  air,  rain-water,  snow,  and  hoar* frost  constantly  con- 
tain small  quantities  of  hydrogen  peroxid;  the  amount  iu  rain-water 
varying  from  0.0008  to  0.05  part  in  100,^X1.  The  most  i*ecent 
experiments  bearing  uptm  the  supposed  presence  of  ozone  and 
hydrogen  peroxid  iu  atmospheric  air  seem,  however,  to  justify  the 
belief  that  those  substances,  if  present  in  ait*  at  all,  are  not  met  with 
in  the  amounts  and  with  the  constancy  that  have  been  claimed. 
According  to  this  latter  view  the  appearances  from  whieh  the  pres- 
ence of  ozone  and  hydrogen  peroxid  has  been  inferred  are  not  caused 
bv  those  substances,  but  by  nitrous  acid  and  the  oxids  of  nitrogen. 


1 
I 


FLUORIN 


125 


CLASS  U— ELEMENTS  WHICH  FORM  NO  COMPOUNDS, 
HKLirM.      NEON.      ARGOX.      KRYPTON.      XENON. 

The  elements  of  this  group  have  been  recently  discovered,  aud 
extiil  iu  air  ami  in  certain  minerals.  As  they  form  no  cotniiounds, 
tlnnr  atomic  weights  are  not  known,  tdthongh,  from  their  moleeular 
heaU,  there  is  reason  to  believe  that  their  molecular  symbols  are  He, 
etc,  not  Hej,  etc. 

Argon,  the  most  alnindant  of  the  elass,  was  discovered  by 
lUyltiigh  and  Ramsay  in  1894  in  air,  in  whieh  it  exist.s  in  the  pro- 
portiun  of  0/J  in  100  by  volunie,  and  1.2  per  cent  by  weight.  It  is  a 
triioiiparent,  color  less,  odorlcs»s,  tasteless  gas;  sp.  ^r*^=19.i)41;  Mw.^^ 
38 J*  At  the  Dormal  pressure  it  liquefies  at  — ISG-O"^,  forming  a 
colorless  liquid  of  sp^  gr.  1.5.  It  solidities  at  — 11)0^.  It  is  sparingly 
soluble  iu  water;  4.05  iu  100.  It  is  obtained  from  atmospheric  air 
as  n  residue  bj  causing  the  other  constitneoits  to  euter  into  combina- 
tion. When  rarified  it  gives  a  characteristic  spectrum  of  many  lines 
with  the  induction  spark, 

Hehum  owes  its  nanie  to  the  fact  that  its  existence  in  the  sun's 
atnifijAphere  was  recognized  by  the  characteristic  line  D:i  of  the  solar 
fipf'.'trum  before  it  was  discovered  as  a  terrestrial  element.  It  exists 
in  certain  rare  uranium  minerals,  and  iu  some  spring  waters.  It  is  a 
v^»^^  light  gas:   Mw.^4. 

The  other  members  of  the  class:  Ncon:Mw.=20;  Krypton; 
Mw,— 81.8;  and  Xenon:  Mw.^128,  have  been  found  in  small  amount 
in  the  I'esidiie  of  evaporation  of  liquefied  air. 


CLASS  III— ACIDULOUS  ELEMENTS. 

Eiemencs  aU  of   wfaoae  Hydrates  are  Acids^  mad  which  do  not  form  Salts  with 


K 


the  Oxa<;ids. 


L    CIILORIN   GROUP. 

PLUORIN.      CHLORIN.      BROMIN,      lODIN. 


Tlje  eleoients  of  this  group,  known  as  the  halogens^  closely 
fetetuble  each  other  iti  their  chemical  properties  and  in  the  structure 
^nd  properties  of  their  compounds,  flnorin  differing  more  from  the 
other  three  than  these  do  from  each  other.  They  are  univalent  in 
IhH  great  majority  of  the  compounds  into  whose  formation  they  enter^ 
ftltlioiigh  they  are  sometimes  trivalent,  as  in  ICln.  With  hydrogen 
^^^}i  forms  an  acid  compound,  composed  of  one  volume  of  the  halogen 
'ii  rtie  gaseous  state  with  one  volume  of  hydrogen.  AH  mineral 
wid«  into  whose  composition  they  enter  are  monobasic.    Fluor  in  is  a 


126  MANUAL    OF    CHEMISTRY 

gas,  liquefiable  with  diflSculty,  chlorin  an  easily  liquefiable  gas,  bromin 
a  liquid,  and  iodin  a  solid  at  the  ordinary  temperature  and  pressure. 
The  relations  of  their  compounds  to  each  other  are  shown  in  the 
following  table: 


HP  

HCl  CI2O  CI2O4  HCIO         HCIO2  HCIO3  HCIO4 

HBr  HBrO  HBrOa  HBrOi 

HI  I2O4  HIO  HIO2  HIO3  HIO4 

Hydro-ie  Monozid.  Tetrozid.  Hypo-  -ons  acid.  -ie  acid.  Per-ie 

acid.  008  acid.  aeid. 

The  heats  of  formation  of  the  halogen  hydracids  diminish  from 
fluorin  to  iodin:  HF= +38,495  cal;  HCl  = +21,997  cal;  HBr=+ 
8,368  cal;  and  HI= — 7,217  cal,  and  the  elements  displace  each  other 
from  their  binary  compounds  in  the  same  order,  i.  e.,  the  fluorin 
compounds  are  the  most  stable  and  those  of  iodin  the  least  so.  In 
the  oxygen  compounds  the  conditions  are  reversed.  Fluorin  forms 
no  oxygen  compound,  and  of  the  other  three  the  order  of  stability  is: 
iodin,  chlorin,  bromin.  The  heats  of  formation  of  the  -ic  acids  are: 
HI03= +55,950  cal;  HC103= +23,910;  and  HBr03=  + 12,194  cal. 
The  heats  of  neutralization  of  hydrochloric,  hydrobromic  and  hydriodic 
acids  are  normal:  13,700  cal;  that  of  hydrofluoric  acid  is  abnormal: 
16,270  cal.  Therefore,  hydrofluoric  acid  is  a  weaker  acid  than  the 
others,  being  less  perfectly  dissociated  (p.  100). 

FLUORIN 

Symbol  =  F— Atomic  iveight  =19  (0=16:  19;  H=l:  18.85)— Sp. 
gr,  1.265  A  {calculated=l.S16)— Discovered  by  Sir  E.  Davy  in  1812. 

Fluorin  has  been  isolated  by  the  electrolysis  of  pure,  dry  HF  at — 
23°  (—9.4°  F.).  It  exists  in  nature  chiefly  in  Fluor  Spar,  CaF2, 
and  in  cryolite,  AI2F6  (NaF)6. 

It  is  a  gas,  colorless  in  thin  layers,  greenish  yellow  in  thick  layers. 
It  decomposes  H2O,  with  formation  of  HF  and  ozone.  In  it  Si,  B, 
As,  Sb,  S,  and  I  fire  spontaneously.  With  H  it  detonates,  even  in  the 
dark.  It  attacks  organic  substances  violently.  The  apparatus  in 
which  it  is  liberated  must  be  made  of  platinum  or  fluor-spar.  It 
forms  compounds  with  all  other  elements  except  oxygen. 

Hydrogen  Fluorid. — Hydroflnoric  ar?rf  =  HF  —  Molecular  weight 
=  20.  Hydrofluoric  acid  is  obtained  by  the  action  of  an  excess  of 
sulfuric  acid  upon  fluor-spar  or  upon  barium  fluorid,  with  the  aid  of 
gentle  heat:  CaF2+H2S04=CaS04+2HF.  If  a  solution  be  desired, 
the  operation  is  conducted  in  a  platinum  or  lead  retort,  whose  beak  is 
connected  with  a  U-shaped  reoeivor  of  the  same  metal,  which  is 
cooled  and  contains  a  small  quantity  of  water. 


(5HL0HIN 


127 


The  pure  acid  is  a  colorless  liquid,  whidi  boils  at  19*^  (67°F  J  ulkI 

iSoHdities  at-'l'*   (30.2'*  PJ.     Sp.  gv.  0.985  at  12''  (53.6"  FJ.     The 

iqaeous  acid  is  a  colorless  liquid,   hig^hly  acid  aad  corrosive,   aud 

having  a  penetrating  odor.    Great  care  irrnst  be  exercised  that  neither 

the  solution  uor  the  gas  cooie  in  contact  with  the  skin,  as  they  pro- 

duc-e  painful  ulcers  which  heal  with  diflienlty,  aud  also  constitutional 

^Sjinptoms  which  may  last  for  days.     The  inhalation  of  air  containing 

ry  small  quantities  of  HP  has  caused  permanent  los.s  of  voice,  and 

ID  two  cases,  death.     When  the  acid  has  acetdentally  cotnc  in  contact 

I  frith  the  skin  the  part  should  be  washed  with  dihitc  solution  of  pot- 

f Ash,  and  the  vesicle  w^iifh  forms  sliould  be  opened. 

Both  the  gaseous  acid  and  its  aolutioti  remove  the  silica  from  glass, 
a  property  utilized  in  etchiu«j  ujkju  tlnit  substance,  the  parts  upon 
which  no  action  is  desired  bein£j  ])roLected  by  a  coating  of  wax- 

The  presence  of  fluorin  in  a  compound  is  detected  by  redncing  the 
substance  to  powder,  moistening  it  with  sulfuric  acid  in  a  platinum 
crucible,  over  which  is  placed  a  slip  of  glass  prepared  as  above.  At 
^the  end  of  half  an  hour  the  wax  is  removed  from  the  glass,  which 
ill  be  found  to  be  etched  if  the  substance  examined  contained  a 
duorid. 

CHLORIN* 

Sumbol^Cl—Aiomic  weight=3rj.5  (0=16:35. 45;H  ==^  1:35.17)— 
Molecular  Hmght=^ll  8p.  .<?r. ^2.4502  A — One  litre  weighs  3,17  grams 
— 100  cubic  inches  weigh  16.3  grains — Name  derived  from  x^*^P^^^ 
ftlloicish  green — Discovered  hij  Svhrele  in  1774, 

Occurrence. — Only  in  combination,  most  abundantly  in  sodium 
cblorid. 

Preparation.^d)  By  heating  together  manganese  dioxid  and 
hydrochloric  acid  (Seheele):   MnO'.+4nCl^MnCl2+2H20+Cl2. 

This  and  similar  operations  are  nsuiilly  conducted  in  ao  apparatus 
BUch  as  that  sliown  in  Fig.  29.  The  earthenware  vessel  A  (which  on 
a  uinatl  scale  may  be  replaced  by  a  glass  Hask)  is  two -thirds  filled 
with  htmps  of  manganese  dioxid  of  the  size  of  hazelnuts  and  adjusted 

th«*  water  bath;    hydrochloric  aeid  is  poured  in  through  the  safety- 

11  be  <ind  the  liath  treated.     The  dist^ugagcd  gas  is  caused  to  bubble 

through  the  smiUl  Quantity  of  water  in  B,  is  then  dried  by  passage 

>ver  the  fragments  of  calcium  chlorid  in  C,  and  is  finally  collected  by 

lis  placement  of  air  in  the  vessel  D. 

When  the  vessel  A  has  become  half  filled  with  liquid  it  is  best  to 

i^decant  the  solution  of  manganons  chlorid,  wash  the  i-emaining  oxid 

rith  water  aud  begin  anew.     A  kilo  of  oxid  yields  257.5  litres  of  €'L 

In  a  modification  of  this  ]irocess»  which  permits  of  the  more  easy 
•vcovery  of  the  mangfinest^   <li*)xid,  nitric   acid    is   used    along  with 


MANUAL    OF    CHEMIflTRY 


bydrochlorki.      The  reaction  i?:    !>HCl+2HNO;i+Mn02=Mii(XO:,). 

+2H2O+CI2.  Tlie  MtiO-  and  HNO3  are  recovered  by  beating  tbe 
Tnaugfanese  nitrate  to  190°  {374"'  F.)  and  treating  the  vapor  Avith  air 
and  steam.  The  reactions  are:  Mii(NO3)2^MnO2H-Nj04  and  N^^O^ 
+H:iO+0=2HNOa. 

(2)  By  the  action  of  manganese  dioxid  upon  hydrochloric  acid  in 
the  presence  of  snifuric  acid*  man»anous  sulfate  being  also  formed; 
Mu02+2HCl+H280,=MnS04+2Ht.O+Cl,.  The  same  quantity  of 
chlorin  is  obtained  as  in  (1),  with  the  use  of  half  the  amount  of 
hydrochloric  acid. 

(3)  By  heating  a  mixture  of  one  part  each  of  mang^anese  dioxid 
and  sodium  chlorid,  with  three  parts  of  sulfuric  acid.     Hydrochloric 


Fio,  2». 

acid  and  sodium  sulfate  are  first  formed:  H2B04+2Niiri^Xa2S04+ 
2HC1;  and  the  acid  is  immediately  decomposed  by  either  of  the  reac- 
tions indioftted  in  (1)  and  (2),  according  as  sulfuric  acid  is  or  is  not 
present  in  excess. 

(4)  By  the  action  of  potassium  dichromate  upon  hydrochloric 
acid;  potassium  and  chromic  chlorids  beingr  also  formed:  K2C^i07+ 
14Hcl=2KCl+Cr'iCU+7H20+3Ck.  Two  parts  of  powdered  dichro- 
mate are  heated  with  17  parts  of  acid  of  sp.  gr.  1.16;  100  grams  of 
the  salt  yielding  22.5  litres  of  CL 

(5)  A  convenient  method  of  obtaining  chlorin  on  a  laboratory 
scale  is  by  the  use  of  "chlorin  cubes."  These  are  made  by  pressing 
together  1  part  of  plaster  of  Paris  and  4  parts  of  chlorid  of  lime 
(q.  v.),  cutting  into  small  cubes  and  drying.     The  cubes  are  used  in 


CHLOKIN 


129 


I 


one  of  the  forms  of  constant  apparatus  {Pigfs,  25,  26,  27),  with  dilute 
hydroohloric  acid,  CI  being  evolved  at  the  ordiuary  temperature. 

When  a  slow  evolution  of  Cl»  extending  over  a  considerable  period 
of  time,  is  desired,  as  for  ordinary  disinfection,  uioistened  eh  lor  id  of 
lime  is  exported  to  the  air,  the  ealeiuni  bypoehlorite  beini,^  JeeoinpoBed 
by  tlie  atnuispherie  carbon  dioxid.  If  a  more  rapid  evolution  of  gas 
be  desired,  the  ohlorid  of  lime  is  moistened  with  dilute  hydrochlorie 
acid  in  place  of  with  water. 

(6)  By  the  action  of  potassium  chlorate  upon  hydrochloric  acid 
CI  is  liberated,  slowly  at  the  ordinary  temperature,  more  rapidly  at 

temperature  of  the  water- bath  :  ^^. 

-f      4HC1       —       Ch       -f      C\^h      +      2KC1       +       2H-,0. 

Bjrdruchloric  rkjorin.  <'hl*irln  Po(Mii»iuin  Water. 

lu-Ui.  tetroxid.  ehlutid. 

(7)  Chlorin  is  obtained  iudustrially  in  the  manufacture  of  caustic 
by  the  electrolysis  of  NaCL 

(8)  In  Deacon's  pn)cess  eupric  oxid  is  used  as  a  **  contact  substance*' 
fi>  oxidize  hydrochloric  acid.  The  reactions  are;  20uCI'>=Cu2Clt*+ 
Ch,  then,  Cu2Cl'j+0.j=2CuO+Cli..  and.  finally,  20uO+4HC1^2Cnn.i 
+2H2O.  As  the  O  is  derived  from  air  the  CI  obtained  is  largely 
dilnted  with  N\ 

(9)  In  the  Holvay,  Weldon  and  Mond  processes  CI  is  derived  from 
magnesium  ohlorid  by  tbc  reaction:   2MgClL'+02^2Mg:0  +  2Cl'i* 

Propertic8.^P/M/^?<YfJf. — A  gi'ceiHsh  yellow  gas»  at  the  ordinary 
tetoperatnre  and  pressure j  it  has  a  penetrating  odor,  and  is,  even 
when  highly  diluted,  very  irritatiufj  to  the  respiratory  passages. 
Being  soluble  in  HjO  to  the  extent  of  one  volume  to  three  volumes  of 
the  solvent,  it  must  be  collected  by  displacement  of  air,  as  shown  in 
Fi^.  29.  A  saturated  arincons  sohititm  of  (1  is  known  to  chemists 
as  chlorin  water,  and  in  pbarmafv  as  aqua  chlori  (U.  8.),  Liquor 
elikxri  (Br.)-  It  should  bleach,  but  not  redden,  litmus  paper^ 
Fntlf^r  a  pressure  of  6  atmospheres  r\i  0*^  {^2^  F,),  or  8%  atmospheres 
at  IS""  (53.6''  FJ,  CI  becomes  an  oily,  yellow  liquid,  of  sp.  ^i\  1.33; 
and  boiling  at^33.6°  {— 28,5°F.).  Liquid  ehlorin,  transported  in 
lead* lined  steel  cyliudei-s,  is  now  an  article  of  commerce. 

CkrmicaL — (^hlorin   exhibits  a   great    tendency  to    combine   with 

oClier  elements,  with  oil  of   wbieb,  except  F,  O,  X,  and  t\  it  unites 

jreetly,  frequently  with    evolution  of   light    as  well    as   beat,   and 

letinies  with  an  explosion.  With  H  it  combines  slowly,  to  form 
liydrocliloric  acid,  under  the  inflnencc  of  diffuse  daylight,  and  vio- 
lently in  direct  sunlight,  or  in  highly  actinic  artificial  lights,  A 
candle  bums  in  CI  with  a  faint  HaTne  and  thick  smoke,  its  H  com- 
bimnc  vi*J>  ^1'*^  ^'^*  while  carbon  1  becomes  free. 


■    otUe 


130  MANUAL    OP    CHEMISTRY 

At  a^redhieat  CI  decomposes  H2O  rapidly,  with  formation  of 
hydrochloric,  chloric,  and  probably  hypochlorons  acids.  The  same 
change  takes  place  slowly  under  the  influence  of  sunlight,  hence 
chlorin  water  should  be  kept  in  the  dark  or  in  bottles  of  yellow 
glass. 

In  the  presence  of  H2O,  chlorin  is  an  active  bleaching  and  disin- 
fecting agent.  It  acts  as  an  indirect  oxidant,  decomposing  H2O, 
the  nascent  O  from  which  then  attacks  the  coloring  or  odorous 
principle. 

Chlorin  is  readily  fixed  by  many  organic  substances,  either  by 
addition  or  substitution.  In  the  first  instance,  as  when  CI  and 
olefiant  gas  unite  to  form  ethylene  chlorid,  the  organic  substance 
simply  takes  up  two  or  more  atoms  of  chlorin:  C2H4+Cl2=C2H4Cl2. 
In  the  second  instance,  as  when  CI  acts  upon  marsh  gas  to  produce 
methyl  chlorid:  CH4+Cl2=CH3Cl+HCl,  each  substituted  atom  of 
CI  displaces  an  atom  of  H,  which  combines  with  another  CI  atom  to 
form  hydrochloric  acid. 

Hydrogen  Chlorid  —  Hydrochloric  Acid  —  Muriatic  Acid  — 
Acidum  Hydrochloricum  (U.  S.;  Br.) — HCl — Molecular  weight=^ 
36.5— /8p.  gr.  1.259  A— A  litre  weighs  1.6293  gram. 

Occurrence. — In  volcanic  gases  and  in  the  gastric  juice  of  the 
mammalia. 

Preparation.— (1)  By  the  direct  union  of  its  constituent  elements. 

(2)  By  the  action  of  sulfuric  acid  upon  a  chlorid,  a  sulfate  being 
at  the  same  time  formed:   H2S04+2NaCl=Na2S04+2HCl. 

This  is  the  reaction  by  which  the  HCl  used  in  the  arts  is  produced, 

(3)  Hydrochloric  acid  is  also  formed  in  a  great  number  of  reac- 
tions, as  when  CI  is  substituted  in  an  organic  compound. 

Properties. — Physical. — A  colorless  gas,  acid  in  reaction  and  tasto^ 
having  a  sharp,  penetrating  odor,  and  producing  great  irritation  when 
inhaled.  It  becomes  liquid  under  a  pressure  of  40  atmospheres  at  4** 
(39.2°  F.)  Its  critical  temperature  is  52""  (125.6''  F.)  nnd  its  critical 
pressure  83  atmospheres.  It  is  very  soluble  in  H2O,  one  volume  of 
which  dissolves  480  volumes  of  the  gas  at  O""  (32°  P.) 

Chemical. — Hydrochloric  acid  is  neither  combustible  nor  a  sup- 
porter of  combustion,  although  certain  elements,  such  as  K  and  Na, 
burn  in  it.     It  forms  white  clouds  on  eonta(;t  with  moist  air. 

Solution  of  Hydrochloric  Acid. — It  is  in  the  form  of  aqueous 
solution  that  this  acid  is  usually  employed  in  the  arts  and  in  phar- 
macy. It  is,  when  pure,  a  colorless  liquid  (yellow  when  impure), 
acid  in  taste  and  reaction,  whose  sp.  gr.  and  boiling-point  vary 
with  the  degree  of  concentration.  When  heated,  it  evolves  HCl, 
if  it  contain  more  than  20  per  cent,  of  that  gas,  and  H2O  if  it  con- 


CHLORIN 


131 


A  solution  oontainiQgr  20  per  cent,  boils  at  111^  (232^  FJ , 
is  of  sp.  gr.  1*099,  has  the  composition  HC1+8H20»  and  distils 
uuchaoged. 

Commercial  muriatic  acid  is  a  j^ellow  liquid;  sp.  gr.  about  1.16; 
^wntains  32  per  cent.  HOI;  and  contains  ferric  chloride  sodium  chlorid; 
Ind  arsenical  compounds.  ^ 

Addum  hydroi'hlorkum  is  a  colorless  liquid,  contaiuing  small 
qnantities  of  impurities.  It  contains  3L9  percent,  HCl  and  its  8p. 
ijr.  i^lJG  (U.  8,;  Br.)  The  dilute  acid  is  the  above  diluted  with 
water.  Sp.  gr.  L049  =  10  per  eent  HCl  (U.  8,);  sp.  gr.  1.052  = 
10.5 per  cent.  HCl  (Br.) 

0.  P.  {chemimJhj  pure)  acid  is  usually  the  same  as  the  strong 
annaceutical  acid  and  far  from  pure  (see  belo%v).  The  strongest 
Motion  has  a  sp.  gr.  of  1.20  and  contains  40.8  per  cent.  HCl. 
Hydroc^hloric  acid  is  classed,  along  with  nitric  and  sulfuric  acids, 
as  one  of  three  strong  mineral  acids.  It  is  decomposed  by  many 
dmentfi,  with  formation  of  a  eblorid  and  liberation  of  hydrogen: 
2HCl+Zn:=ZuCl2+H2.  With  oxids  and  hydroxids  of  the  metals  it 
♦nt^rs  into  double  decomposition,  forming  H2O  and  a  chlorid:  CaO+ 
2Ha==CaCl,+  H20  or  CaHi>02+2HCl^CaCl,+2H,0. 

Oxidizing  agents  deeonipose  HCl  with  liberation  of  CL  A  raix- 
Hiri'  of  hydrochloric  and  nitric  acids  in  the  proportion  of  three 
laukTules  of  the  former  to  one  of  the  hitter  (18  cc.  HNO3:  82  cc. 
Iir'Uolii,),  is  the  acidnnn  nitrohydrochloricum  (U,  8.;  Br.),  or 
dquaregia.  The  latter  UHUie  alludes  to  its  power  of  dissolving  gold, 
by  com  hi  nation  of  the  nascent  CI,  which  it  liberates,  with  that  metal. 
*o  form  the  soluble  auric  chlorid  (p.  193). 

Impurities.— A  chemically  pure  solution  of  tliis  acid   is  cxcced- 

ittgly  rare.      The  impurities  usual I3-  present   are:    Sul/urous  acid— 

hydrogen  snlfid  is  given  off  when  the  acid  is  poured  upon  zine;   Sul- 

fyricacid — a  white  precipitate  is  formed  with  barium  chlorid;  Chlorin 

colors  the  acid  yellow;   Ijead  gives  a  black  color  when  the  acid  is 

treated  with  hydrogen  sulfid;   Iron — the  acid  gives  a  red  color  with 

aojnjoniiim  thiocyanatc;  Arsenic^the  method  of  testing  by  hydrogen 

wilfid  is  not  sufficient.     If  the  acid  is  to  be  used  for  toxicological 

analvgis,  a  litre »  diluted  with  half  as    much  H2O.  and  to  which  a 

fmall  quantity  of  potassium  chlorate  has  l>een  added*  is  evaporated 

orer  the  water  bath  to  400  cc;  25  (*c.  of  sulfuric  acid  are  then  added, 

and  the  evaporation  continued  until  the  liquid  measures  about  100  cc. 

This  in  introduced   into  a  Marsh  apparatus  and  must  produce  no 

aumyr  during  an  hour. 

Chlorids, -^A  few  of  the  chlorids  are  liquid,  SnCl*,  SbCh;  the 
remainder  are  solid,  crystalline  and  more  or  less  volatile.  The  me- 
tallic chlorids  are  soluble  in  water,  except  AgCI  and  HggCh*  which 


132 


MANUAL    OF    CHEMlSTRr 


are  insoluble,  and  PbCl2,  and  CusCh^  which  are  sparingly  soluble. 
The  chlorids  of  the  iion- metals  are  decomposed  by  H^O. 

The  chlorids  are  formed:  (1)  By  the  direct  union  of  the  elements: 
P  +  Cl5  =  PCl5;  (2)  By  the  action  of  ehlorin  upon  a  heated  mixture 
of  oxid  and  carbon:  AlaOa  +  SC  +  SCh^AlaCU+SCO;  (3)  By  solu- 
tion of  the  metal,  oxid,  hydroxid,  or  carbonate  in  HCl:  Zn  +  2HC1=^ 
Z0CI2+H2;  (4)  By  double  decomposition  between  a  solution  of  a 
chlorid  and  that  of  another  salt  whose  metal  forms  an  insoluble 
chlorid :  AgNOa  +  NaCl  ^ AgCl  +  NaNO:, . 

Chloridion^ Analytical  Characters. —  Solutions  of  hydrocliloric 
acid  and  of  chlorids  contain  the  ion,  chloridiou  Cl',  which  gives  the 
following  reactions:  (1)  With  AgNOa  a  white,  floeculeot  ppt.,  insoL 
in  HNOa,  soL  in  NH4HO.  (2)  With  Hg2  (NOa)^,  a  white  ppt..  which 
turns  black  with  NH4HO, 

Toxicology*— Poisons  and  Corrosives,— ^4  poison  is  ant/  sub- 
sfancr  which,  being  in  solutiou  iw,  or  aciing  rhemicaU^  upon  the  bloody 
may  produce  death  or  serions  bodiJtj  harm. 

A  corrosive  is  a  snhstnnce  capable  of  prodtteing  death  bif  its  chemi* 
cal  art  ion  upon  a  tissue  with  which  if  romfS  in  dirrrt  cotttart. 

The  corrosives  act  mneli  more  energetically  when  concentrated 
than  when  dilute;  and  when  the  dilution  is  great  they  have  no  dele- 
terious action.  The  degree  of  concentration  in  which  the  true  poisons 
are  taken  is  of  little  inflnenee  upon  their  action. 

Under  the  above  deliuitions  the  strong  mineral  acids  act  as  corro* 
sives  rather  than  as  poisons.  They  produce  their  injurious  results  by 
destroying  the  tissues  with  which  they  come  in  eontaet,  and  will  cause 
death  as  surely  by  destroying  a  large  surface  of  skin  as  when  they 
are  taken  into  the  stomaeh. 

The  symptoms  of  corrosion  by  the  mineral  acids  begin  immedi- 
ately, during  the  act  of  swallowing*  The  chemical  action  of  the  acid 
upon  every  part  with  which  it  comes  in  contact  causes  acute  burning 
pain»  extending  from  the  month  to  the  stomach  and  intestine,  referred 
chiefly  to  the  epigastrium.  Violent  and  distressiug  vomiting  of  dark, 
tarry,  or  "  coffee  -  ground/'  highly  acid  material  is  a  prominent 
symptom.  Eschars,  at  first  white  or  gray,  later  brown  or  black,  ai'e 
formed  where  the  acid  has  come  in  contact  with  the  skin  or  mucous 
raerahrane.  Respiration  is  labored  and  painful,  partly  by  pressure 
of  Hie  abdominal  muscles,  but  also,  in  the  ease  of  hydrochloric  acid, 
from  entrance  of  the  irritating  gas  into  the  respiratory  passages. 
Death  may  occur  within  twenty -four  hours,  from  collapse;  moi-e 
sutldenlj^  from  perforation  of  large  blood-vessels,  or  from  peritonitis; 
or  after  several  weeks,  secondarily,  from  starvation,  due  to  closure  of 
the  pylorus  by  inflammatory  thickeniug,  and  destruction  of  the  gastrio 
glands. 


BROMIN 


133 


ft 


The  object  of  tbe  treatment  in  corrosion  by  the  niineral  acids  is  to 
neutralize  the  acid  and  convert  it.  into  a  harmless  salt.  For  this  pur- 
pose the  best  agent  is  magnesia  (magnesia  usta),  suspended  in  a  small 
qtiautityof  water,  or  if  this  be  not  at  hand,  a  strong  solution  of  soap. 
rhalk  and  the  earbonates  and  bicarbonates  of  sodinni  and  potassium 
should  not  be  given,  as  they  generate  large  volumes  of  gas.  The 
sempings  of  a  plastei'ed  waD,  or  oil,  are  entirely  useless.  Any  attempt 
ait  tht*  introduction  of  a  tube  into  the  oesophagus  is  attended  with 
cjjiuger  of  perforation,  except  in  the  earliest  stages  of  the  intoxication. 

Compounds  of  Chlorin  and  Oxygen. — Two  compounds  of  chlorin 
and  oxygen  are  known.  They  are  both  very  unstable^  and  prone  to 
sudden  and  violent  decomposition. 

P  Chlorin  Monoxid.— CI2O — Bl^Hijimchlorouii  anhtfdrid  or  oxiti,  is 
formed  by  the  action,  below  20*^'  (68°  F.),  of  dry  CI  upon  precipi- 
Uted  mercuric  oxid:  HgO+2Cl2^HgCl2+CI^O. 

On  contact  with  E-jO  it  forms  hypochlorous  acid,  HC10»  which 
^  owing  to  its  instability,  is  not  used  industrially,  although  the  hypo- 
H  eUcvrites  of  Ca,  K,  and  Na  are. 

■  Chlorin  Tetroxid — Vhlorin  pemxhi,   CljOi — 135— is    a  violeutly 

H  ffxplosive  body,  produced  by  the  action  of  sulfuric  acid  upon  potas- 
H  Slum  chlorate.  Below — 20*^  ( — ^4°  F.)  it  is  an  orange -colored  litjuid, 
^b|kove  that  temperature  a  >ellow  gas.  It  explodes  violently  when 
^^Vnited  to  a  temperature  below  lOO"^  (212"^  F.),  There  is  no  corre- 
sponding hydrate  known,  and  if  it  be  brought  in  contact  with  an 
alkaline  hydroxid,  a  mixture  of  chlorate  and  chlorite  is  formed. 

Besides  the  above,  two  oxacids  of  V\  are  known,  the  anhydrids 
eofTi'«ponding  to  which  have  not  been  isolated. 

Chloric  Acid— HC10:t^ — 84.5^ — obtained,  in  aqueous  solution,  as 
m  strongly  acid,  yellowish,  syrupy  liquid,  by  decomposing  its  barium 
salt  by  the  proper  quantitity  of  sulfuric  acid. 

Perchloric  Acid— H(:104 — 1W.5 — ^is  the  most  stable  of  the  series. 
It  is  obtained  by  boiling  potassiuTU  chlorate  with  hydrofluosilicie 
arid.  d«H*anting  the  cold  fluid,  cvaporatiug  until  white  fumes  appear, 
decanting  from  time  to  time,  and  finally  distilling.  It  is  a  colorless, 
oily  liquid;  sp.  gr.  1,782;  which  explodes  on  contact  %Tith  organic 
snbataiices  or  charcoal. 


BROMIN* 


Bromum,  U.  S.,  Br. — %i«6o/=Br. — Aiomie  wehjht^=SO — (0=16: 
79.96;  H=l:  79 M)—Mohcular  fveight=WOSp,  gi\  of  Uqnid^ 
3.1872  at  0*^;  of  rfri>t*r=5,52  A-^Freezinrj  ;>oiJ*^=  — 24.5°  (—12.1'' 
f^) — Boiling  /*mitf=63*^  {145,4^  I'.)— JVrt/«e  derived  from  Pp^f*^^^ 
Mirmtk — Discovered  hij  Baiard  In  1826, 


134  MANUAL    OF    CHEMISTRY 

Occurrence. — Only  in  combination,  most  abundantly  with  Na 
and  Mg  in  sea  water  and  the  waters  of  mineral  springs. 

Preparation. — It  is  obtained  from  the  mother  liquors,  left  by  the 
evaporation  of  sea  water,  and  of  that  of  certain  mineral  springs,  and 
from  sea  weed.  These  are  mixed  with  sulfuric  acid  and  manganese 
dioxid  and  heated,  when  the  bromids  are  decomposed  by  the  CI  pro- 
duced, and  Br  distils. 

Properties.— PAystca/. — A  dark  reddish -brown  liquid,  volatile  at 
all  temperatures  above— 24.5°  ( — 12.1°  F.);  giving  off  brown-red 
vapors  which  produce  great  irritation  when  inhaled.  Soluble  in 
water  to  the  extent  of  3.2  parts  per  100  at  15°  (59° P.);  more 
soluble  in  alcohol,  carbon  disulfid,  chlorofonn,  and  ether. 

Chemical, —  The  chemical  characters  of  Br  are  sirailnr  to  those 
of  CI,  but  less  active. — With  H2O  it  forms  a  crystalline  hydrate  at 
0°(32°  F) :  Br5H20.  Its  aqueous  solution  is  decomposed  by  exposure 
to  light,  with  formation  of  hydrobromic  acid. 

It  is  highly  poisonous. 

Hydrogen  Bromid — Hydrobromic  acid — Acidum  hydrobromi- 
cum  dil.  (U.  S,)  =  HBr-'  Moleailar  weight=  SI  — Sp,  gr.  =  2.71 
A—A  litre  weighs  3.63  grams— Liquefies  a< -^69°  (— 92°.2  F.)  — 
Solidifies  a<— 73° (—99.4°  F.). 

Preparation. — This  substance  cannot  be  obtained  from  a  bromid 
as  HCl  is  obtained  from  a  chlorid.  It  is  produced,  along  with 
phosphorous  acid,  by  the  action  of  H2O  upon  phosphorus  tribro- 
mid:  PBr3+3H20=H3P03+3HBr;  or  by  the  action  of  Br  upon 
paraffin. 

Properties. — A  colorless  gas;  produces  white  fumes  with  moist 
air;  acid  in  taste  and  reaction,  and  readily  soluble  in  H2O,  with 
which  it  forms  a  hydrate,  HBr2H20.  Its  chemical  properties  are 
similar  to  those  of  HCL 

Bromids  closely  resemble  the  chlorids  and  are  formed  under 
similar  conditions.  They  are  decomposed  by  chlorin,  with  forma- 
tion of  a  chlorid  and  liberation  of  Br:2KBr+Cl2=2KCl+Br2.  The 
metallic  bromids  are  soluble  in  H2O,  except  AgBr  and  HgoBrz,  which 
are  insoluble,  and  PbBro,  which  is  sparingly  soluble.  The  bromids 
of  Mg,  Al,  Ca  are  dtM»omposed  into  oxid  and  HBr  on  evaporation 
of  their  aqueous  solutions. 

Bromidion — Analjrtical  Characters.— Solutions  of  hydrobromic 
acid  and  of  bromids  contain  the  anion  Br^  which  gives  the  following 
reactions:  (1)  With  AgNOa,  a  yellowish  white  ppt.,  insoluble  in 
HNO3,  sparingly  soluble  in  NH4HO.  (2)  With  chlorin  water  a  yellow 
solution  which  communicates  the  same  color  to  chloroform  and  to 
starch -paste. 


lODIN  135 

Hypobromous  Acid — HBiO 97 — is  obtained,  in  aqaeous  solu- 
tion, by  the  action  of  Br  up)on  mercuric  oxid,  silver  oxid,  or  silver 
nitrate.  When  Br  is  added  to  concentrated  solution  of  potassium 
hydroxid  no  h3rpobromite  is  formed,  but  a  mixture  of  bromate  and 
bromid,  having  no  decolorizing  action.  With  sodium  hydroxid, 
however,  sodium  hypobromite  is  formed  in  solution;  and  such  a 
solution,  freshly  prepared,  is  used  in  Knop's  process  for  determin- 
ing urea  (q.  v.). 

Bromic  Acid — HBrOa — 129— has  only  been  obtained  in  aqueous 
solution,  or  in  combination.  It  is  formed  by  decomposing  barium 
bromate  with  an  equivalent  quantity  of  sulfuric  acid :  Ba  (Br03)2+ 
HjS04=2HBrO3+BaSO4.  In  combination  it  is  produced,  along  with 
the  bromid,  by  the  action  of  Br  on  caustic  potassa  :  3Br2+6KHO= 
KBr03+5KBr+3H2O. 

Pcrbromic  Acid— HBr04 — 145 — is  obtained  as  a  comparatively 
stable,  oily  liquid,  by  the  decomposition  of  perchloric  auid  by  Br, 
and  concentrating  over  the  water- bath. 

lODIN. 

ledum  (U.  S.;  Br.)— Symbol^I-- Atomic  weight=l21  (0=16: 
126.97;  IL=\i\2&. 01)— Molecular  weight =254— 8p.  gr,  of  solid = 
4.948;  of  vapor=S.7}6  A'-Fuses  at  113.6°  (236.5''  F.)— Boils  at 
175®  (347°  F,) — Name  derived  from  litArp=violet — Discovered  by 
<}ourtoi8  in  1811. 

Occurrence. — In  combination  with  Na,  K,  Ca,  and  Mg,  in  sea- 
^ater,  the  waters  of  mineral  springs,  marine  plants  and  animals. 
Cod-liver  oil  contains  about  37  parts  in  100,000. 

Preparation. — It  is  obtained  from  the  ashes  of  sea-weed,  called 
^h>  or  varech.  These  are  extracted  with  H2O,  and  the  solution 
evaporated  to  small  bulk.  The  mother  liquor,  when  separated  from 
the  other  salts  which  crystallize  out,  contains  the  iodids,  which  are 
decomposed  by  CI,  aidf^d  by  heat,  and  the  liberated  iodin  is  condensed. 

Properties. — Physical. — Blue-gray,  crystalline  scales,  having  a 
metallic  luster.  Volatile  at  all  temperatures,  the  vapor  having  a 
violet  color  and  a  peculiar  odor.  The  density  of  vapor  of  iodin,  at 
^ne  atmosphere  of  pressure  and  at  temperatures  between  its  boiling 
P^int  and  about  500°  is  254  (0=32),  corresponding  to  the  molecular 
^^rmuhi  I2  (p.  56),  but  above  that  temperature  the  density  dimin- 
'«hea,  until  at  1,500°  it  has  fallen  to  127,  corresponding  to  the  molec- 
ular formula  I,  where  it  remains  constant.  Molecular  iodin  is,  there- 
fore, dissociated  by  heat  (p.  90).  Iodin  is  very  sparingly  soluble  in 
w;iff»r.  hut  the  aqueous  solution,  standing  over  excess  of  iodin,  con- 


136 


MANUAL    OF    CHEMISTRY 


tiniies  to  dissolve  it  by  reasOQ  of  the  formatiou  of  hydrladie  acid, 
8>Uitiotis  of  hydriodie  acid  aad  of  metallic  iodids  dissolve  notably 
larger  qaaiitities  of  iodin  than  does  pure  water,  proba'jly  beeau^e  of 
trie  formation  of  the  ion  I3'*  Iodin  is  very  soluble  in  4*coholj  etiier, 
elilorofortn,  benzene  and  carbon  bisnIM.  With  the  three  last  named 
solvents  the  solutions  are  vio!et»  with  others  brown  in  eolor* 

Chemical,— In  its  chemical  characters  I  resembles  CI  and  Br,  but 
is  less  active.  It  decomposes  Hi«0  slowly  and  is  a  weak  bleacliiu^ 
and  oxidizing:  agent.  In  presence  of  water,  it  decomposes  hydrogen 
sulfid  with  formation  of  hydriodie  acid,  and  liberation  of  snlfnr. 
It  does  not  combine  directly  with  oxygen,  but  does  with  ozone 
PotassinQa  hydroxid  solntion  dissolves  it»  with  formation  of  potas^ 
sinm  iodid,  and  some  hypoiodite.  Nitric  acid  oxidizes  it  to  iodic 
acid.  With  ammonium  hydroxid  solution  it  forms  the  explosive 
nitrogen  iodid. 

Toxicology. — Taken  internally,  iodin  acts  both  as  a  local  irritant 
and  as  a  true  poison.  It  is  disubarged  as  an  alkaline  iodid  by  the 
urine  and  perspiratian,  and  when  taken  in  large  quantity  it  appears 
io  the  faeces. 

The  poison  should  be  removed  as  rapidly  as  possible  by  the  use  of 
the  stomach  pump  and  of  emetics.  Farinaceous  substances  may  also 
be  given. 

Hydrogen  Iodid — Hydriodie  acid — HI — Mohunlar  weight ^^127, 80 

Preparation,^ — By  the  deeompositiou  of  phosphorus  triiodid  by 
water:  PLi+SH^O^HaPO^^+^HI.  Or,  in  sokition  by  passing  hydro- 
gen sulfid  through  water  holding  iodin  in  snspeusion;  HgS+Ig= 
2HI+S. 

Properties — A  colorless  gas,  forming  white  fumes  on  eon 
with  air,  and  of  strongly  acid  reaction.  Under  the  influence  of  cohl 
and  pressure  it  forms  a  yelhiw  liquid,  which  solidilies  at  — 55^  ( — 07"^ 
P.),  Water  dissolves  it  to  the  extent  of  425  volumes  for  each  volnnie 
of  the  solvent  at  K)"*  (50''  FJ. 

It  is  partly  decomposed  into  its  elements  by  heat,  Mix»-d  witli  O 
it  is  decomposed,  even  in  the  dark,  with  ft»rmation  of  H2O  and  liber- 
ation of  L  Under  the  influence  of  sunlight  the  gas  is  slowly  decom- 
posed, although  its  solutions  are  not  so  affected,  if  they  be  free  from 
un\  Chloriu  and  bromin  decompose  it,  with  liberation  of  iudin. 
With  many  metals  it  forms  iodids.  It  yields  up  its  H  readily  and  is 
used  in  organic  chemistry  as  a  source  of  that  element  in  the  nascent 
state. 

Iodids  are  formctl  under  the  same  conditions  as  the  chlorids  and 
br  unids,  which  they  resemble  in  their  properties.    The  metallic  iodids 


^ 

1 


JS^ 


I 


^ 


lODIN 


137 


Are  aolable  in  water^ — except  Agl^  ^gzh,  which  are  insoluble, 
aod  Pbl^,  which  is  very  slig'htly  soluble.  The  ioilijs  of  the  earth 
metals  are  decora  posed  into  ox  id  and  HI  on  evaporation  of  their 
aqaeous  solntions.  Chlorin  decomposes  the  iodids  as  it  does  the 
bromide. 

lodidion — ^Analytical  Characters.— Solutions  of  hydriodie  aeid  or 

of  iodids  contain  iodidion,  I^,  which  forras  a  yellow  ppt.,  insol,  in 

HNO3  and  in  NHiIIO,  with  A^'NOa.    Brown  solutions  of  excess  of 

iodlu  in  HI  or  KI  contain  triodtdion,  I3',  which,  as  iodin  is  removed 

from  the  solution,  is  decomposed  into  F+I3.     Aqueous  or  alcoholic 

solutions  of  free  iodin,  not  of  iodidion,  color  starch  paste  dark  blue 

or  black,  and  chloroform  or  carbon  bisulfid  violet.    The  same  colors 

are  produced  with  solutions  of  iodids  after  liberation  from  them  of 

free  iodin  by  fumingr  HNO:i  or  chlorin  water.    At  about  100"^  starch 

iodid  is  dissociated  and  decolorized,  the  color  returning  on  cooling. 

Chlorids  of  Iodin *^C*hlorin  and  iodin  combine  with  eacli  other  in 
two  piTiportions  r  Iodin  monochlorid,  or  protochlorid — ICl  is  a  red- 
brown,  oily,  puugent  liquid,  formed  by  the  action  of  dry  CI  upon  I, 
ami  flistilling  at  100^'  (212T.).  Iodin  trichlorid,  or  perchlorid— 
ICh  is  a  yellow,  crystalline  solid,  havioii:  an  astringent,  acid  taste 
8iid  a  penetrating  odor;  very  volatile;  its  vapor  irritating;  easily 
soluble  in  water.  It  is  formed  by  saturating  H>0  holding  I  in*sns- 
pension  with  CI,  and  adding  concentrated  sulfuric  acid.  ICln  has 
^^mi  used  as  an  antiseptic. 

Oxacids  of  Iodin.— The  ln'st  known  of  these  arc  the  liighest  two 
of  the  scries — iodic  and  periodic  acids. 

Iodic  Acid — niOji — 17(>,8r>  is  formed  as  an  iodate,  whenever  I  is 
ussah'f'd  in  a  solution  of  an  alkaline  hydi^xid;  Io+6KHO=KI03+ 
.>K1t3H20.  As  the  free  acid,  by  the  action  of  strong  oxidizing 
»;TDtjj,  such  as  nitric  acid,  or  fhloric  acid,  upon  I;  or  by  passing  CI 
for^onie  time  through  H2O  holding  I  in  suspension. 

Iodic  acid  appears  in  white  crystals,  decomposable  at  170^  (338*^ 
P.),  and  quite  soluble  in  H2O,  the  solution  haviug  an  acid  reaction, 
and  tt  bitter,  astringent  taste. 

It  is»  an  energetic  <rxidizing  agent,  yielding  up  its  O  readily,  with 
reparation  of  elementary  I  or  of  IIL  It  is  used  as  a  test  for  the 
preseocc  of  morphin  (q.  r  j. 

Periodic  Acid— }1I0|— 19h85— is  formed  by  the  action  of  CI 
Upon  an  alkaline  solution  of  sodium  lodatc.  The  sodium  salt  thus 
obtattied  is  dissolved  in  nitric  acid,  treated  with  silver  nitrate,  and 
the  refruhing  silver  pcriodatc  is  then  decomposed  with  IhO,  From 
the  solution  the  acid  is  obtained  in  colorless  crystals,  fusible 
•t  130**  (266*  PJ,  very  soluble  in  water,  and  readily  decoTuposable 
by  heat. 


138  MANUAL    OF    CHEMISTRY 


'  n.  SULFUR  GROUP. 

SULFUR.      SELENIUM.      TELLURIUM. 

The  elements  of  this  group  are  bivalent  in  most  of  their  com- 
pounds, in  some  they  are  quadrivalent  or  hexavalent.  With  hydrogen 
they  form  compounds  composed  of  one  volume  of  the  element,  in  the 
form  of  vapor,  with  two  volumes  of  hydrogen  —  the  combination 
being  attended  with  a  condensation  in  volume  of  one-third.  Mineral 
acids  in  which  they  occur  are  dibasic.  They  are  all  solids  at  ordi- 
nary temperatures.  The  relation  of  their  compounds  to  each  other  is 
shown  in  the  following  table: 

H28  SOo  8O3  H2SO2  H2SO3  H2SO4 

HzSe  Se02  SeOa  HjSeOa  H2Se04 

H2Te  Te02  TeOa  H2Te08  ^2Te04 

Hydro-ic  acid.  Dioxid.  Trioxid.  Hypo-ous  acid.  -ous  acid.  -ic  acid. 


SULFUR. 


o 


8ymbol  =  S^ Atomic  weight  =  32(0  =  16: 32.06;  H  =  l:31.8)— 
Molecular  weight  =^64: — 8p.  gr,  of  vapor  =2,22  A — Fuses  at  114^ 
(23?.2°  F.)— Boils  at  447.3°*  (837°  F.). 

Occurrence.  —  Free  in  crystalline  powder,  large  crystals,  or 
amorphous,  in  volcanic  regions.  In  combination  in  sulflds  and  sul- 
fates, and  in  protein  substances. 

Preparation. — By  purification  of  the  native  sulfur  or  decomposi- 
tion of  pyrites,  natural  sulfids  of  iron. 

Crude  sulfur  is  the  product  of  the  first  distillation.  A  second 
distillation,  in  more  perfectly  constructed  apparatus,  yields  refined 
sulfur.  During^  the  first  part  of  the  distillation,  while  the  air  of 
the  condensing  chamber  is  still  cool,  the  vapor  of  S  is  suddenly  con- 
densed into  a  fine,  crystalline  powder,  which  is  flowers  of  sulfur, 
sulfur  sublimatum  (U,  S,),  Later,  when  the  temperature  of  the 
condensing  chamber  is  above  114°,  the  liquid  S  collects  at  the  bot- 
tom, whence  it  is  drawn  off  and  cast  into  sticks  of  roll  sulfur. 

Properties. — Physical. — Sulfur  is  usually  yellow  in  color.  At 
low  temperature,  and  in  minute  subdivision,  as  in  the  precipitated 
milk  of  sulfur,  sulfur  praecipitatum  ( U.  S.),  it  is  almost  or  quite 
colorless.  Its  taste  and  odor  are  faint  but  characteristic.  At  114° 
(237.2°  F)  it  fuses  to  a.  thin  yellow  liquid,  which  at  150°-160° 
(302°- 320°  F.)  becomes  thick  and  brown;  at  330°- 340°  (  62G- 
642.2°  F.)  it  again  becomes  thin  and  light  in  color;  finally  it  boil^, 
giving  off  brownish  yellow  vapor  at  a  temperature  variously  stated 


SULFUR  139 

*etwcea  440°  (824''  P.)  and  448°  (838.4°  P.).  Tf  heated  to  about 
400**  (752°  F.)  and  suddenly  cooled,  it  is  converted  into  plastic  sul- 
idr,  which  may  be  moulded  into  any  desired  form.  It  is  insoluble 
in  water,  sparingly  soluble  in  aniliu,  phenol,  benzene,  petroleum 
ether,  and  chloroform;  readily  soluble  in  sulfur  chlorid,  S2CI2,  and 
carbon  di^ulfid.  It  dissolves  in  hot  alcohol,  and  crystallizes  from  the 
^solution,  on  cooling,  in  white  prismatic  crystals.  It  is  dimorphous. 
When  fused  sulfur  crystallizes  it  does  so  in  oblique  rhombic  prisms. 
Its  solution  in  carbon  disulfid  deposits  it  on  evaporation  in  rhombic 
octahedra.  The  prismatic  variety  is  of  sp.  gr.  1.95  and  fuses  at  120° 
(248°  F.)-,  the  sp.  gr.  of  the  octahedral  is  2.05  and  its  fusing  point 
114.5°  (238°  P.).  The  prismatic  crystals,  by  exposure  to  air,  become 
opaque,  by  reason  of  a  gradual  conversion  into  octahedra. 

Chemical. — Snl:ur  unites  readily  with  other  elements,  especially 
^t  liigli  temperatures.  Heated  in  air  or  O,  it  bums  with  a  blue  flame 
to  sulfur  <lioxid,  SO2.  In  II  it  burns  with  formation  of  hydrogen  sulfid, 
H2S.  The  compounds  of  S  are  similar  in  constitution,  and  to  some 
extent  in  chemical  properties,  to  those  of  O.  In  many  organic  sub- 
stances S  may  replace  O,  as  in  thiocyanic  acid,  CNSH,  corresponding 
to  cyanic  acid,  CNOH.  Such  compounds  are  designated  by  the 
syllable  ihio ;  the  syllable  sulfa,  in  the  name  of  a  compound,  indicates 
that  it  contains  the  bivalent  group,  SO2. 

Sulfur  is  used  principally  in  the  manufacture  of  gunpowder;  also 
to  some  extent  in  making  sulfuric  acid,  sulfur  dioxid,  and  matches, 
and  for  the  prevention  of  fungoid  and  parasitic  growths. 

Hydrogen  Monosulfid — Sulfhydric  acid — Hydrosulfuric  acid — 
Sulfuretted  hydrogen — H2S — Molecular  weight=S4 — 8p,gr, =1,19  A. 

Occurrence. — In  volcanic  gases;  as  a  product  of  the  decomposition 
of  organic  substances  containing  S;  in  solution,  in  the  watei*s  of 
»me  mineral  springs;  and,  occasionally,  in  small  quantity,  in  the 
Sases  of  the  intestine.  It  is  produced  from  proteins  and  other 
organic  substances  containing  S  by  microbic  action  (sulfhydric 
fermentation). 

Preparation. —  (I)  By  direct  union  of  the  elements;  either  by 
'>nrning  S  in  H,  or  by  passing  H  through  molten  S. 

(2)  By  the  action  of  nascent  II  upon  sulfuric  acid,  if  the  mixture 
*^®come  heated.     (See  Marsh  test  for  arsenic.) 

(•3)  Bv  the  action  of  HCl  upon  antimony  trisulfid:  Sl)2S3+6IICl= 
2SbCl3+3H2S. 

(4)  By  the  action  of  dilute  sulfuric  acid  upon  ferrous  sulfid:  FeS 
+H^SO|=FeS04+H2S.  This  is  the  method  generally  used.  The 
*^  slionld  be  purified  by  passage  over  dry  calcium  chlorid,  then 
through  a  tube,  20  cent,  long,   loosely  filled  with  solid  iodin,  and. 


140 


MANUAL    OF    CHEMISTRY 


finally,  through  a  solutiou  of  potassium  sulM.     The  purpose  of  the 
iodin  is  to  arrest  traces  of  hydrogen  arsenid,  which  may  be  present. 

(5)  By  the  action  of  HCl  upou  r-aleium  sulfid:  €'aS+2HCl-^ 
CaCl2+ 11:^8. 

Properties.^ — PhtjsmtL — ^A  colorless  gas  having  the  odor  of  rotten 
eggs  and  a  disgusting  taste;  soluble  iu  H^^O  to  the  extent  of  3.23 
parts  to  1  at  15°  {59°  FJ  ;  soluble  hi  alcohol.  Under  17  atmospheres 
pressure,  or  at  — 74°  ( — 101.2°  FJ  at  the  ordinary  pressure,  it  lique- 
fies;  at  —85.5°  {—122°  FJ  it  forms  white  crystals. 

Chemical, — Burns  in  air  with  formation  of  sulfur  dioxid  and  water: 
2H2S+302=2802+2H.>0.  If  the  supply  of  oxygen  be  deficient,  H2O 
is  formed,  and  sulfur  liberated:  2H2S  +  02'=2H20  +  S2.  Mixtures  of 
II-i8  and  air  or  O  explode  on  coutaet  with  flame.  Solutions  of  the  gas 
when  exposed  to  air  become  oxidized  with  deposition  of  S.  Such 
sohitious  should  be  made  with  boiled  Yi-zO,  and  kept  in  bottles  which 
are  completely  filled,  atut  well  corked.  Oxidizing  agents,  CI,  Br,  and 
I  remove  its  H  witli  deposition  of  S.  Hydrogen  sulfid  and  sulfur 
dioxid  mutually  decompose  each  other  into  water,  pentathionic  acid 
and  sulfur:  4802+3H->8=2H'jO+IL.S,0«+S2. 

When  the  gas  is  passed  through  a  solution  of  an  alkaline  by- 
droxid  its  8  disphices  the  O  i^f  the  hydroxid  to  form  a  sulfhydrate: 
H28  +  KHO=H20-fKHS.  With  solutions  of  metallic  salts  H2S 
usually  relinquishes  its  S  to  the  metal:  CUSO4+H28— CuS+H^SO^, 
a  property  which  renders  it  of  great  value  in  analytical  chemistry. 

Physiological, — Hydrogen  sulfid  is  produced  in  the  intestine  by 
the  decomposition  of  protein  substances  or  of  taurochloric  acid; 
it  also  occurs  sometimes  in  abscesses,  and  in  the  urine  in  tu1»ercu* 
losis,  variola,  and  cancer  of  the  bladder.  It  may  also  reach  the 
bladder  by  diffusion  fiM>m  the  rectum. 

Toxicology- — An  animal  dies  almost  immediately  in  an  atmos- 
phere of  pure  IhjS,  and  the  diluted  gas  is  still  rapidly  fataL  An 
atmosphere  containing  1  i>er  cent  may  be  fatal 
individuals  habituated  to  its  presence  can  exist 
c*ontainiug  3  per  cent.  E%Tn  when  highly  diluted 
d.ition  of  low  fever,  and  care  is  to  be  taken  that 
lories  in  which  it  is  used  shall  not  become  contaminated  with  it.  Its 
toxic  powers  are  due  primarily,  if  not  entirely,  to  its  power  of 
reducing  and  combining  with   the  blood  ^coloring  matter. 

The  form  in  which  hydrogen  snlfid  generally  produces  deleterious 
effects  is  as  a  constituent  of  the  gases  emanating  froni  sewers,  privies, 
burial  vaults,  etc.  These  give  rise  to  either  slow  poisoning,  as  when 
r?wer  gases  are  admitted  to  sleeping  and  other  apartments  by  de- 
fective plumbing,  or  to  sudden  poisoning,  as  when  a  person  enters  a 
vault  or  other  locality  containing  the  noxious  atmosphere. 


to  man,  although 
in  an  atmosphere 
it  produces  a  coii- 
tbe  air  of  In  bora- 


> 


SULFUR 


141 


The  treatment  should  consist  in  promotingr  the  inhalation  of  pure 
|«r,  artificial  respiration,  cold  affustons,  and  the  admrnistration  of 
|:64ia]u]ant.s. 

Lfter  death  the  blood  is  found  to  be  dark  in  color,  and  give^the 
^tnim  shown  in  Fig.  30»  due  to  snlf haemoglobin. 
Sulfids  and  Hydrosulfids, — These  coniponiids  bear  the  snme 
relation  to  snlfnr  that  the  oxids  and  hydroxide  i1o  to  *ixygen.  The 
t^TQ  snlfids  of  ari^enic,  AsaSrt  and  As^Sr*,  cori'efipond  to  the  two  oxids, 
AssOi  and  AS2O5,  and  the  potassium  hydrosnlfid,  KHS,  corresponds  to 
the  hydroxid,  KHO. 

Many  metallic  suHkls  occur  in  natuif,  and  arc  inipiirtaut  ores  of 
the  metals,  as  the  sulfids  of  zinc,  mercury,  cobalt,  nickel,  and  iron* 
They  are  formed  artificially,  eitlicr  by  direct  union  of  the  elements  at 
elevated  temperatures,  as  in  the  case  of  iron:  Fe+S^^FeS;  or  by 
reduction  of  the  corresponding  sulfate,  as  in  the  case  of  calcium: 
lCaSO*+2C=CaS'f2C02. 

The  sulfids  are  insoluble  in  Hl*0,  except  those  of  the  alkali  metals. 
Many  of  the  sulflds  are  soluble  in  alkaline  liquids,  and  behave  as 

Kii  Be      D         rii      F  3  H 

mmmm 

Fig   3t> 

thio-anhydnds,  forming  thio- salts,  corresponding  to  the  oxysalts, 
ThuH  potassium  arsenate,  K^AsO^i  and  tbioarseuate,  K3ASS4;  anti- 
inonate,  KaSbOi,  and  thioautinionate,  K:i8b84. 

The  metallic  sulfids  are  deeon) posed  when  heated  in  air,  usually 
with  the  formation  of  sulfur  dioxid  and  the  metallic  oxid;  sometimeii 
with  the  fonualion  of  the  sulfate;  and  sometimes  with  the  liberation 
of  the  metal,  and  the  formation  of  sulfur  dioxid,  The  strong  mineral 
acids  det'orapose  tlie  sulfids  with  formation  of  hydrogen  nionosulfid. 

Analytical  Characters . — Htftfrogfti  Stf  J  fid.  —  ( I )  Bl  acke  1 1  s  \m  pe  r 
mois5tened  with  lead  acetate  solution,  (2)  Has  an  odor  of  rotten 
egg*** 

Snlfith.  —  il)  Heated  in  the  oxidizing  flame  of  the  blowpipe,  give 
a  blue  flamr  and  odor  of  8O2.  (2)  With  a  mineral  acid  give  off  US 
(exc*ept  liulflds  of  Hg.  An,  and  Pt), 

Hydrogen  Polysulfids. — Several  other  compounds  of  S  and  H, 
eorr»*!^ponding  to  tbc  polysulfids  of  K,  Na,  and  Ca,  are  known.  The 
tn^Hit  fttuhle  i&  hydrogen  pentasutlid,  US:^,  which  can  only  exist  in 
the  absence  of  water  and  at  low  temperatures. 


142  MANUAL    OF    CHEMISTRY 

Sulfur  and  the  Halogens.— But  one  eomponnd  of  S  and  Ct 
exists:  Sulfurous  chlorid,  S2CI2,  formed  when  S  is  distilled  in  an 
atmosphere  of  CI.  It  is  a  yellow,  fuming  liquid,  used  as  a  solvent 
for  S.     Several  oxyehlorids  are  also  known. 

Bromin  in  contact  with  excess  of  S  forms  a  red  liqnid  which 
consists  principally  of  S2Br2. 

The  iodid,  S2I2,  is  obtained  by  heating  together  32  parts  8  and 
127  parts  I.  It  is  a  steel-gray,  crystalline  substance,  fusible  at  60^ 
(140°  F.),  insoluble  in  water;  and  has  been  used  in  medicine- 
Sulfur  Dioxid. — Sulfurous  oxid,  or  anhydrid — Acidum  sulfuro- 
sum  (U.  S.  ;  Br.) — SO2 — Molecular  w€ighi:=Q^ — 8p.  gr,  of  gag== 
2.213  ;  of  liquid=lAd— Boils  at  —10''  (14°  F.);  solidifies  at  —75*^ 
(— 103°-F.). 

Occurrence. — In  volcanic  gases  and  in  solution  in  some  mineral 
waters. 

Preparation. — (1)  By  burning  S  in  air  or  O. 

(2)  By  roasting  iron  pyrites  in  a  current  of  air. 

(3)  During  the  combustion  of  coal  or  coal-gas  containing  S  or 
its  compounds. 

(4)  By  heating  sulfuric  acid  with  copper:  2H2S04+Cu=CuS04+ 
2H2O+SO2. 

(5)  By  heating  sulfuric  acid  with  charcoal:  2H2S04+C=2S02+ 
CO2+2H2O. 

(6)  By  decomposing  calcium  sulfite,  made  into  cubes  with  plaster 
of  Paris,  by  HCl,  at  the  ordinary  temperature. 

When  the  gas  is  to  be  used  as  a  disinfectant  it  is  usually  obtained 
by  reaction  (1);  in  sulfuric  acid  factories  (2)  is  used;  (3)  indicates 
the  method  in  which  atmospheric  SO2  is  chiefly  produced  ;  in  the 
laboratory  (4)  and  (6)  are  used  ;  (5)  is  the  process  directed  by  the 
U.  S.  and  Br.  Pharmacopoeias. 

Properties. — Physical, — A  colorless,  suffocating  gas,  having  a 
disagreeable  and  persistent  taste.  Very  soluble  in  H2O,  which  at  15^ 
(59°  P.)  dissolves  about  40  times  its  volume  (see  below) ;  also  soluble 
in  alcohol.  At  — 10°  (14°  F.)  it  forms  a  colorless,  mobile,  transpar- 
ent liquid,  by  whose  rapid  evaporation  a  cold  of  — 65°  ( — 85°  F.)  is 
obtained.  Liquid  SO2  packed  in  sealed  tins  or  in  syphons,  is  now 
a  commercial  article. 

Chemical,  Sulfur  dioxid  is  neither  combustible  nor  a  supporter  of 
combustion.  Heated  with  H  it  is  decomposed:  S02+2H2=S+2H20. 
With  nascent  hydrogen,  H2S  is  formed:  S02+3U2=H2S+2H2O. 

Water  not  only  dissolves  the  gas,  but  combines  with  it  to  form  the 
true  sulfurous  acid,  IL.SO3.  With  solutions  of  metallic  hydroxids  it 
forms   metallic  sulf/es:    S02+KHO  =  KHS03;     or  S02+2KHO  = 


SULFUR  143 

KSSO3+H2O.     A  hydrate  having  the  composition  H2SO3,  8H2O  has 
been  obtained  as  a  crystalline  solid,  fusible  at  +4°  (39.2°  P.). 

Sulfur  dioxid  and  sulfurous  acid  solution  are  powerful  reducing 
agents,  being  themselves  oxidized  to  sulfuric  acid:  S02+H20+0= 
H2S04;  or  H2S03+0=H2S04.  It  reduces  nitric  acid  with  formation 
of  sulfuric  acid  and  nitrogen  tetroxid:  S02+2HN03=H2S04+N204. 
It  decolorizes  organic  pigments,  without,  however,  destroying  the 
pigment,  whose  color  may  be  restored  by  an  alkali  or  a  stronger  acid. 
It  destroys  KSi  acting,  in  this  instance,  not  as  a  reducing  but  as  an 
oxidizing  agent:  4S02+3H2S=2H20+H2S506+S2.  With  CI  it  com- 
bines directly  under  the  influence  of  sunlight  to  form  dulfuryl  chlorid 

(S02)''Cl2. 

Analytical  Characters. — (1)  Odor  of  burning  sulfur. 
(2)  Paper  moistened  with  starch  paste  and  iodic  acid  solution 
turns  blue  in  air  containing  1  in  3,000  of  SO2. 

Sulfur  Trioxid — Sulfuric  oxid  or  anhydrid — SO3 — Molecular  weight 
=80— Sp,  gr.  1.95. 

Preparation.— (1)  By  union  of  SO2  and  O  at  250°-300°  (482°- 
572®  P.')  or  in  presence  of  spongy  platinum. 

(2)  By  heating  sulfuric  acid  in  presence  of  phosphoric  anhydrid: 

H2SO4+P205=S03+2HP03. 

(3)  By  heating  dry  sodium  pyrosulf ate :   Na2S207=Na2S04+S03. 

(4)  By  heating  pyrosulfuric  acid  below  100°  (212°F.),  in  a  retort 
fitted  with  a  receiver,  cooled  by  ice  and  salt:  H2S207==H2S04+S03. 

Properties. — White,  silky,  odorless  erj-stals  which  give  off  white 
fumes  in  damp  air.  It  unites  with  H2O  with  a  hissing  sound,  and 
elevation  of  temperature,  to  form  sulfuric  acid.  When  dry  it  does 
not  redden  litmus. 

Sulfur  trioxid  exists  in  two  isomeric  (see  isomerism)  modifications, 
being  one  of  the  few  instances  of  isomerism  among  mineral  substances. 
The  a  modification,  liquid  at  summer  temperature,  solidifies  in  color- 
less prisms  at  16''  (60.8''  P.)  and  boils  at  46°  (114.8''  P.).  The  P 
isomere  is  a  white,  crystalline  solid  which  gradually  fuses  and  passes- 
into  the  a  form  at  about  50°  (122°  F.) 


Oxacids  of  Sulfur. 

H2SO2  Hyposulfurous  acid.  H2S2O7  Pyrosulfuric  acid. 

H28O3  Sulfurous  acid.  H2S2O6  Dithionic  acid. 

H2SO4  Sulfuric  acid.  HsSjOe  Trithionio  acid. 

HiSjOj  Persulfuric  acid.  IIjS^Oo  Tetrnthionic  ncid. 

HjSoOa  Thioaulfuric  acid.  H2S50«  Pentatliionic  acid. 


144 


MANUAL    OF    CHEMISTRY 


Hyposulfurous  Acld^-H 3803—66.^ — Hydrosulfurous  acid — Is  an 
onstable  body  known  only  in  solution,  obtained  by  the  action  of  zinc 
upon  solution  of  sulfurons  acid.  It  is  a  powerful  bleaching  and  de- 
oxidizing agent, 

SuMurous  Acid— H^SO:! — 82. —  Although  sulfurons  acid  has  not 
been  isolated,  it,  in  all  probability,  exists  in  the  acid  solution,  formed 
when  sulfur  dioxid  is  dissolved  in  waterr  S02+H20=S03H2.  Its 
saltSg  the  sulfites,  are  well  defined.  From  the  existence  of  certain 
organic  derivatives  (see  sulfonie  aeids)  it  would  seem  that  two  iso- 
meric modifications  of  the  acid  may  exist.  They  are  distinguished  as 
the  symmfirieaJl  in  which  the  S  atom  is  qnadi'ivalent. 


o=s 


OH 
OH' 


and  the  nnsymmefrical^  in  which  the  S  at<jui  is  hexavalent. 

H 


s : 


OH 


Sulfites. — The  sulfites  are  decomposed  by  the  stronger  acids,  with 
evolution  of  sulfur  dioxid.  Nitric  acid  oxidizes  them  to  sulfates. 
The  sulfites  of  the  alkali  nielals  are  soluble,  and  are  active  reducing 
agents. 

The  anal3rtical  characters  of  the  sulfites  (sulfosion)  arer  (1) 
With  HCl  they  give  off  SO2.  (2)  With  zinc  and  HCl  they  give  off 
H2S*  (3)  With  AgNO:j  tliey  form  a  white  ppt.,  soluble  in  excess  of 
sulfite,  and  depositing  metallic  Ag  when  the  mixture  is  boiled.  (4) 
With  Ba  (N0:i)2  they  form  a  white  ppt.,  soluble  in  HCL  If  chlorin 
water  be  added  to  the  solution  so  formed  a  white  ppt.,  insoluble  in 
acids,  is  produced^ 

Sulfuric  Acid — Oil  of  Vitriol —Acid  um  sulfuricum  (U.  S,;  Br  J 

Preparation.  —  (1)  By  the  union  of  sulfur  trioxid  and  water: 
S0.+H^0==n,S04. 

(2)  By  the  oxidation  of  8O2  or  of  S  in  the  preseuce  of  water; 
2B02+2H20+02=2HnS04;  or  S2+2H.>0+30o=2H2804. 

The  manufacture  of  H2SO4  may  be  said  to  be  the  basis  of  all 
chemical  industry,  as  there  are  but  few  processes  in  chemical  tech- 
nology into  some  part  of  which  it  does  not  enter.  The  method  fol- 
lowed at  present,  the  result  of  gradual  improvement,  may  be  divided 
into  two  stages:  (1)  the  formation  of  a  dilute  acid;  (2)  the  con- 
centration of  this  product. 

The  first  part  is  carried  on  in  immense  chambers  of  timber,  lined 
with  lead,  aud  furnishes  an  acid  having  a  sp,  gr.  of  1.55,  and  con- 
taining 65  per  cent  of  tnie  sulfuric  acid,  H2SO4.  Into  these  cham- 
bers  SOtii  obtained   by  burning  sulfur,  or   by  roasting  pyrites,   is 


1 


SULBTR 


143 


i 


* 


driven,  along  with  a  large  excess  of  air.  In  the  chambers  it  conieg 
in  contact  with  nitric  acid,  at  the  expense  of  which  it  is  oxidized 
to  H2S04»  while  nitrogen  tetroxid  (red  fumes)  h  formed:  SO2+ 
2HN03=H2S04+N204.  Were  this  the  only  reaction,  the  disposal 
I  the  red  fnmes  would  present  a  serious  difficulty  and  the  amount 
f  nitric  acid  consumed  would  be  very  great.  A  second  rcnctiou 
occurs  between  the  red  fumes  and  H2O,  which  is  injected  in  tho 
form  of  steam,  by  which  nitric  acid  and  nitrogen  dioxid  are  prr»- 
dneed  :  3N204+2H20=4IiN03H-2NO.  The  nitrogen  dioxid  in  turn 
combines  with  O  to  produce  the  tetroxid,  which  then  regenerates 
a  further  quantity  of  nitric  acid,  and  so  on.  This  series  of  reac- 
tions is  made  to  go  on  continuously,  the  nitric  acid  being  con- 
stantly regenerated,  and  acting  merely  as  a  carrier  of  O  from 
the  air  to  the  SOu,  in  such  manner  that  the  sum  of  the  reactions 
may  be  represented  by  the  following  equation:  2SO2+2H2O+O2— 
2H2SO4. 

The  acid  is  allowed  to  collect  in  the  chambers  until  it  has  the  sp, 
^*  1.55,  when  it  is  drawn  off.  This  chamber  add,  although  used  in 
a  few  industrial  processes,  is  not  yet  strong  enough  for  most  pur- 
I>oees.  It  is  concentrated,  first,  by  evaporation  in  shallow  leaden 
pans*  until  its  sp.  gr,  reaches  1.746.  At  this  point  it  begins  to  act 
npOQ  the  lead,  and  is  transferred  to  platinum  stills,  where  the  con- 
centration is  completed. 

Varieties. ^Sulfuric  acid  is  met  with  in  several  conditions  of 
concentration  and  purity: 

(1)  The  commercial  oil  of  vitriol,  largely  used  in  tnanufacturing 
processes,  is  a  more  or  less  deeply  colored,  oily  liquid,  varj'itig  in  sp, 
j»T.  from  1.833  to  1.842,  and  in  coneentration  from  93  per  cent  to 
1>9%  per  cent  of  tnie  II-SO4. 

(2)  C*  P,  acid^^Acidum  sulfuricum  (V,  S,;  Br.),  of  sp.  gr, 
l.ft4,  colorless  and  eomparatively  pure  (see  IjcIow), 

(3)  Glarittl  stflfttric  ttrid  is  a  hydnile  of  the  composition  H2S0j, 
H:^*  iJometinics  called  hihijiiraftd  sulfuric  acid,  which  crystallizes  in 
rlinmbic  prisms,  fusible  at  +8.5°  (47.3°  FJ  when  an  acid  of  sp.  gr. 
I,7ft8  is  cooled  to  that  temperature. 

(4)  Ac.  sttlf.  dii.  (U.  8.;  BrJ  is  a  dilute  acid  of  sp,  gr.  LOGO 
and  eontaining  between  9  and  10  per  cent.  H2SO4  (U.  S,),  or 
of  ^p*  gr.  1,094,  containing  between  12  and  13  per  cent.  H2SO4 
(Br.). 

Properties. — Pkifj^icaL — A  colorless,  heavy,  oily  liquid;  sp,  gr. 
1  M2  at  12°  (53.7'"  F.);  crystallizes  at  10.5''  (50.9T.);  boils  at  338'' 
(640.4** P.).  It  is  odorless,  intensely  acid  in  taste  and  reaction^  and 
highly  corrosive.     It  is  non*  volatile  at  ordinarj^  temperatures.     Mix* 


146  MANXAL    OF    CHEMISTRY 

tur^s  of  the  aoiJ  with  H2O  have  a  lower  boiliug  point,  and  lower  sp. 
^r.  as  tlie  pru^Hjrtiou  of  H2O  increases. 

(7(ki/<«V«</. — At  a  nnl  heat  vapor  of  H2SO4  is  partly  dissociated 
iulo  Si.>'j  and  lliO:  or,  in  the  presence  of  platinum,  into  SO2,  H^O 
and  O.  When  heateil  with  S,  C,  P,  Ilg,  Cu,  or  Ag,  it  is  reduced 
with  toniuitiou  of  SO2. 

Sulfuric  acid  has  a  great  tendency  to  absorb  H2O,  the  union  being 
uttcudt^l  with  elevation  of  temperature,  increase  of  bulk,  and  diminu- 
tion of  sp.  gr.  of  the  acid,  and  contraction  of  volume  of  the  mixture. 
Thivc  (>arts,  by  weight,  of  acid  of  sp.  gr.  1.842,  when  mixed  with 
one  part  of  H-A^  prvnluce  an  elevation  of  temperature  to  130°  (266° 
KJ,  aud  the  tx^sulting  mixture  occupies  a  volume  1-6  less  than  the 
sum  of  the  volumes  of  the  constituents.  Strong  H2SO4  is  a  good 
desiccator  of  air  or  gases.  It  should  not  be  left  exposed  in  uncovered 
vessels,  lest  by  increase  of  volume  it  overflow.  When  it  is  to  be 
diluli^^l  with  lUO,  the  acid  should  be  added  to  the  H2O  in  a  vessel  of 
1 1)  In  jijhiss,  to  avoid  the  projection  of  particles,  or  the  rupture  of  the 
Nwsscl  It  is  by  virtue  of  its  affinity  for  H2O  that  H2SO4  chars  or 
\ich\drates  orgauio  substances.  Sulfuric  acid  is  a  powerful  dibasic 
acid. 

The  v'ommen*ial  acid  is  very  impure.  The  colorless  so-called  C.  P. 
m-ul  iiia\  als\>  contain:  PbS04,  which  forms  a  black  ppt.  when  the 
dilute  acid  is  nvalcd  with  H2S;  SO2,  which  gives  off  H2S  when  the 
diluic  acid  is  added  to  Zu;  As,  which  appears  as  a  mirror  when  the 
diluic  acul  is  examined  by  Marsh's  test;  oxids  of  nitrogen,  which 
rojimiuuicalc  a  ivd  or  pink  color  to  pure  brucin. 

SulUtca.  Sulfuric  acid  being  dibasic,  there  exist  two  sulfates  of 
ilk'  univalcnl  mclals:  HKSO4  and  K2SO4,  and  but  one  sulfate  of 
lai  h  l»ivalcul  metal:  CaS04.  The  sulfates  of  Ba,  Ca,  Sr,  and  Pb  are 
iu.M»luMc.  i»r  very  sparingly  soluble,  in  H2O.  Other  sulfates  are  soluble 
ui  llji>,  {^\\i  all  aiv  insoluble  in  akohol. 

Analytical  Characters. — Because  of  the  dibasic  character  of  sul- 
turu*.  acid  »ls  solutions  and  those  of  its  salts  may  contain  two  kinds 
v»r  auivni:  SO| '  iu  dilute  solutions  of  the  acid  and  in  solutions  of 
neutral  sulfates,  and  SO4H'  in  concentrated  solutions  of  the  acid 
{\\.  iO  anvl  iu  si>lutious  of  acid  sulfates.  In  the  following  analytical 
ivailious  it  IS  iunuaterial  which  anion  is  present  if  the  reaction  be 
ojil.N  Mlitfhtlv  aeiil,  because  then,  as  SO4"  is  removed  by  combination 
Willi  I  he  cations  Ba",  Pb",  or  Ca",  the  anion  SO4H'  is  decom- 
jKvied  to  SOi"  \-\V;  but  when  the  solution  is  strongly  acid  a  small 
l^>iv»jK»riK»u  of  SO4II'  may  remain  unprecipitated. 

^  I  >  Uarium  chlorid  (or  nitrate) ;  a  white  ppt.,  insol.  in  dil.  acids. 
\\w  ppt...  dried  aud  heated  with  charcoal,  forms  BaS,  which,  with  HC1» 
v^fc\v'«»  s^H  ILS.    (2)   Plumbic  acetate  forms  a  white  ppt.,  insol.  in  diL 


SELENroM    AND    TELLURIUM  147 

acids.  (3)  Calcium  chlorid  forms  a  white  ppt.,  either  immediately 
or  apou  dilution  with  two  volumes  of  alcohol:  insol.  in  dil.  HCl 
or  HNOa. 

Toxicology. — Sulfuric  acid  is  an  active  corrosive,  and  may  be,  if 
taken  in  sufficient  quantity  in  a  highly  diluted  state,  a  true  poison. 
The  concentrated  acid  causes  death,  either  within  a  few  hours,  by 
corrosion  and  perforation  of  the  walls  of  the  stomach  and  oesoph- 
aps,  or,  after  many  weeks,  by  starvation,  due  to  destruction  ot 
the  gastric  mucous  membrane  and  closure  of  the  pyloric  orifice  of 
the  stomach. 

The  treatment  is  the  same  as  that  for  corrosion  by  HCl  (see 
papel32). 

Pcrsulfuric  Acid. — H2S2O8— 194 — is  formed  by  the  electrolysis  of 
concentrated  sulfuric  acid:  2H2S04=H2S208+H2  ;  or  by  the  action  of 
hydrogen  peroxid  on  sulfuric  acid  :  2H2S04+H202=H2S208+2H20. 
It  crystallizes  at  0°  in  long,  transparent  needles.  The  corresponding 
anhydrid.  S2O7,  is  formed  by  the  action  of  high  tension  electric  cur- 
rents in  a  mixture  of  dry  SO2  and  O. 

Thiosulfuric  Acid. — Hyposulfurous  acid — H2S2O3 — 114 — may  be 
considered  as  sulfuric  acid,  H2SO4,  in  which  one  atom  of  oxygen  has 
been  replaced  by  one  of  sulfur.  The  acid  itself  has  not  been  iso- 
lated, being  decomposed,  on  liberation  from  the  thiosulfates,  into 
solfur,  water,  and  sulfur  dioxid  :  H2S203=S+S02+H20. 

Pyrosulfuric  Acid.— Fuming  sulfuric  acid — Nordhausen  oil  of 
fiiriol — Disulfuric  hydrate — H2S2O7 — Molecular  weight=17S — Sp,  gr, 
=L9-Boil8  at  52.2°  (126°  F), 

Preparation. — By  distilling  ferrous  sulfate;  and  purification  of 
the  product  by  repeated  crystallizations  and  fusions,  until  a  sub- 
stance fusing  at  35°  (95°  P.)  is  obtained. 

Properties. — The  commercial  Nordhausen  acid,  which  is  a  mix- 
ture of  H2S2O7  with  excess  of  SO3,  or  of  H2SO4,  is  a  brown,  oily 
liquid,  which  boils  below  100°  (212°  P-)  giving  off  SO3;  and  is  solid 
or  liquid  according  to  the  temperature.  It  is  used  chiefly  as  a  sol- 
vent for  indigo,  and  in  the  anilin  industry. 


SELENIUM   AND   TELLURIUM. 

Se— 78.5     Te— 126. 

These  are  rare  elements  which  form  compounds  similar  to  those 
of  sulfur.  Elementary  selenium  is  used  in  some  forms  of  electrical 
apparatus. 


148 


MANUAL    OP    CHEMISTRY 


m.  NITROGEN  GROUP. 

NITROGEN — PHOSPHORUS— ARSENIC — ^ANTIMONY. 

The  elements  of  this  group  are  trivalent  or  quinqaivalent,  occa- 
sionally univalent.  With  hydrogen  they  form  non-acid  compounds, 
composed  of  one  volume  of  the  element  in  the  gaseous  state  with 
three  volumes  of  hydrogen,  the  union  being  attended  with  a  conden- 
sation of  volume  of  one -half. 

Bismuth,  frequently  classed  in  this  group,  is  excluded,  owing  to 
the  existence  of  the  nitrate  Bi(N03)3.  The  relations  existing  between 
the  compounds  of  the  elements  of  this  group  are  shown  in  the  follow- 
ing table: 


NH3, 
PH3. 

AsHs, 
8bH3, 

N2O, 

NO 

N2O3,             NO2, 
P2O3,               - 
AsjOs,           — 
Sb203,        SbaO* 

N2O5. 
P2O5, 
A82O6, 
SbjOs, 

H3PO2, 

Hyd- 
rid. 

Mon- 
oxid. 

Di- 
oxid 

Trl- 
oxid. 

Tetr- 
oxid. 

Pent- 
oxid. 

Hypo-OQS 
acid. 

H3PO3, 
H3A8OS, 

H4P2O6, 
H4A82O5, 

t 

HNO2, 

HA8O2, 
HSb02, 

H3PO4, 

H3A8O4, 

fl38b04, 

H4P2O7, 
H4A82O7, 

H48b207, 

HNO3, 
HPO3, 
HA8O3, 
HSbOa, 

-ons 
acid. 

Pyro-oua 
acid. 

Meta-ons 
acid. 

-Ic 
acid. 

Pyro-ic 
acid. 

Meta-ic 
acid. 

While  the  hydrogen  compounds  of  the  halogens  are  strong  aciu^, 
and  those  of  the  sulfur  group  are  weak  acids,  NH3  is  strongly  basic 
(see  hydrazin,  hydroxylamiu  and  hydrazoic  acid,  pp.  151,  152),  PHs 
is  weakly  basic,  and  AsHa  and  SbHa  are  neutral.  Oxids  of  the  types 
N2O,  NO  and  NO2  are  neutral,  those  of  the  types  N2O3  and  N2O5  are 
anhydrids.  The  oxyacids  vary  in  basicity:  the  types  H3PO2,  HNO2 
and  HNO3  are  monobasic,  H3PO2  dibasic,  H3PO4  tribasic,  and  H4P2O5 
and  H4P2O7  tetrabasic. 

NITROGEN. 

Azote— Symbol=^— Atomic  weight  =  14:  (0  =  16:14.04;  H=l: 
IS. 93)— Molecular  weight  =  2S—Sp.  gr, =0,9701— One  litre  weighs 
1.254  grams — Name  from  viVpov^nitre,  y^y€(ri^-=source ;  or  from  i, 
privative  i^F^Ufe — Discovered  by  Mayoiv  in  1669. 

Occurrence. — Free  in  atmospheric  air  and  in  volcanic  gases.  In 
combination  in  the  nitrates,  in  ammoniacal  compounds  and  in  a  great 
number  of  animal  and  vegetable  substances. 

Preparation.  — (1)  By  removal  of  O  from  atmospheric  air;  by 
burning  P  in  air,  or  by  passing  air  slowly  over  red-hot  copper.  It  is 
contaminated  with  CO2,  H2O,  etc. 


NITROGEN 


149 


(2)  By  passing:  Gl  through  excess  of  ammoniom  hydroxid  solo- 
tion.  If  ammonia  be  not  Tnaintained  in  excess,  the  CI  reacts  with 
the  ammoninm  cliloritl  formed,  to  produce  the  explosive  oitrogen 
f^lorid. 

(3)  By  heating  ammonium  nitrite  (NH^)N02:  or  a  mixture  of 
ammonium  chlorid  and  potassium   nitrite. 

Properties, — A    colorless,    odorless,    tasteless,    non- combustible 
Ha;    not   a   supporter  of   combustion;     very   sparingly   soluble    in 

It  is  very  slow  to  enter  into  combination,  and  most  of  its  com- 
pounds ar^  very  prone  to  decomposition,  which  may  occur  expio- 
sively  or  slowly.  Nitrogen  eomhines  directly  with  O  under  the 
infiuence  of  electric  discharges;  and  with  H  under  like  conditions, 
and,  directly,  during  the  decomposition  of  uitrogenized  organic  sub- 
iianoes.  It  combines  directly  with  magnesium,  boron,  vanadium, 
and  titanium. 

Nitrogen  is  not  poisonous,  but  is  incapable  of  supporting  respi- 
ralioo. 


Atmospheric  Air.— The  alchemists  considered  air  as  an  element, 
until  Mayow,  in  1669,  demonstrated  its  complex  nature.  It  was  not, 
however,  until  1770  that  Priestley  repeated  the  work  of  Mayow;  and 
that  the  compound  nature  of  nn\  and  tlie  charaeters  of  its  con* 
slttui^nts  were  made  generally  known  by  the  labors  (1770-1781)  of 
Prift*»tley,  Rutherford,  Lavoisier,  and  Cavendish.  The  older  chemists 
ittu^  the  terms  gas  and  air  as  synonymous. 

Composition. — Air  is  not  a  chemical  compound,  but  a  mechanical 
mtxture  of  O  and  N,  with  smaller  quantities  of  other  gases.  Leaving 
oal  of  consideration  vapor  of  water  and  small  quantities  of  other 
^iisies.  except  0.03  of  carbon  dioxid,  air  consists  of  20.95  O  and 
79.02  N  (including  argon),  bj'  volume  ;  or  about  23  O  and  77  N,  by 
weigrht  ;  proportions  which  vary  but  very  slightly  at  different  times 
and  places;  the  extremes  of  the  proportion  of  O  found  having  been 
30.908  and  20.099. 

That  air  is  not  a  compound  is  shown  by  the  fact  that  the  pro- 
portion of  its  constituents  does  not  represent  a  relatiou  between 
their  atomic  weights,  or  between  any  multiples  thereof  ;  as  well  as 
bj  the  solubility  of  air  in  water.  Were  it  a  compound  it  would 
have  a  definite  dcgi^ee  of  solubility  of  its  own,  and  the  dissolved 
fpm  woald  have  the  same  composition  as  when  free.  But  each  of 
ft*  constituents  dissolves  in  H2O  according  to  its  own  solubility, 
and  air  dissolved  in  H2O  at  14.1*^  (57.4'^  F.)  consists  of  N  and  O, 
not  in  the  proportion  given  above,  but  in  the  proportion  of  66.7fi 
to  33.24. 


150  MANUAL    OF    CH£MISTBY 

Besides   these   two    main   constituents,    air  contains   about 
thousandths  of  its  bulk  of  other  substances;  vapor  of  water,  carl 
dioxid,  ammoniacal  compounds,  hydrocarbons,  ozone,  oxids  of  nil 
gen,  and  solid  particles  held  in  suspension. 

Vapor  of  Water. — Atmospheric  moisture  is  either  visible,  as 
fog^s  and  clouds,  when  it  is  in  the  form  of  a  finely  divided  liquid; 
invisible,  as  vapor  of  water.  The  amount  of  H2O  which  a  gi 
volume  of  air  can  hold,  without  precipitation,  varies  according  to 
temperature  and  the  pressure.  It  happens  rarely  that  air  is  as  hig 
charged  with  moisture  as  it  is  capable  of  being  for  the  existing  t 
perature.  The  fraction  of  saturation,  or  hygrometric  state,  or  r 
tive  humidity  of  the  atmosphere  is  the  percentage  of  that  quantity 
vapor  of  water  which  the  air  could  hold  at  the  existing  temi)era1 
and  pressure  which  it  actually  does  hold.  Thus  air  with  a  humi< 
of  100  is  saturated,  and  a  diminution  of  temperature  or  of  press 
would  cause  precipitation;  but  an  increase  of  temperature  or  of  p 
sure  would  cause  a  diminution  of  humidity.  Ordinarily  air  conti 
from  66  to  70  per  cent,  of  its  possible  amount  of  moisture.  If 
quantity  be  less  than  this,  the  air  is  dry,  and  causes  a  parched  sei 
tion,  and  the  sense  of  "stuffiness"  so  common  in  furnace -hei 
houses.  If  it  be  greater,  evaporation  from  the  skin  is  impeded, 
the  air  is  oppressive  if  warm. 

The  actual  amount  of  moisture  in  air  is  determined  by  passii 
known  volume  through  tubes  filled  with  calcium  chlorid;  wl 
increase  in  weight  represents  the  amount  of  H2O  in  the  volume  of 
used.  The  humidity  is  determined  by  instruments  called  hygr< 
eters,  hygroscopes  or  psychrometers. 

Carbon  Dioxid. — The  quantity  of  carbon  dioxid  in  free  air  va 
from  3  to  6  parts  in  10,000  by  volume.     (See  Carbon  dioxid.) 

Ammoniacal  Compounds. — Carbonate,  nitrate,  and  nitrite 
ammonium  occur  in  small  quantity  (0.1  to  6.0  parts  per  millioi 
NH3)  in  air,  as  products  of  the  decomposition  of  nitrogenized  org 
substances.     They  are  absorbed  and  assimilated  by  plants. 

Nitric  and  Nitrous  acids,  usually  in  combination  with  ammoni 
are  produced  either  by  the  oxidation  of  combustible  substances  < 
taining  N,  or  by  direct  union  of  N  and  H2O  during  discharge! 
atmospheric  electricity.  Rain-water,  falling  during  thunder-show 
has  been  found  to  contain  as  much  as  3.71  per  million  of  HI 

Sulfuric  and  Sulfurous  acids  occur,  in  combination  with  J 
in  the  air  over  cities,  and  manufacturing  districts,  where  they 
produced  by  the  oxidation  of  S,  existing  in  coal  and  coal-gas. 

Solid  particles  of  the  most  diverse  nature  are  always  preser 
air  and  become  visible  in  a  beam  of  sunlight.  Sodium  chlori 
almost  always  present,  always  in  the  neighborhood  of   salt  wi 


NITROGEN 


151 


Air  oon tains  myriads  of  gerois  of  vegerahle  orgatiisms,  mould,  eh-., 
which  are  pi-opagated  by  the  transportation  of  these  germs  by  air* 
currents. 

Compounds  of  Nitrogen  and  Hydrogen. — Three  are  known: 
Ammonia,  XH;r;  Hydrazine  N.:H4;  and  Hydrazoic  acid,  X^H;  us 
wt?ll  US  suits  e*irrt*spondiiif^  to  two  hydroxids. 

Ammonia.  —  Hf/dmtffn  nitrUl^  VolafUe  alkali — NHu — Moleeuhir 
treujhf^MSp,  ^r.— 0.589  A—JAquefifs  af  —40°  (—40°  F.)^Boiis 
ni  —33.7"  (—28.7''  F.)—8omips  at  —lo""  (—103''  F.)— A  litre 
u'*ighft  0,7655  grain. 

Preparation. — (1)   By  union  of  inisueiit  H  with  X, 

(2)  By  decomposition  of  organic  matter  eontaining  N,  either 
spontaneously  or  by  destruetive  distiliatioii, 

(3)  By  heating  solution  of  amnmnium  hydroxid:  NH4H0^^NHj+ 
HjO, 

PropcTtics,— 'l*hy$ tea i, — A  ct^lorlfss  gas,  having  a  pnugent  odor, 
and  an  acrid  taste.  It  is  very  soluble  in  HjO^  1  vtdnme  of  wldeh  at 
0°  (32''  F.)  dissolves  1050  vols.  XHa,  iind  at  15''  (alt"^  FJ,  727  vols. 
NHti,  Alcohol  and  ether  also  disscdve  it  readily.  Lkpiid  animfuiia  is 
«  colorless,  mobile  fluid,  used  in  ice  machines  for  producing  artificial 
Md,  the  liquid  absorbing  a  great  ansount  of  heat  in  volatilizing. 

ChmticaL~At  a  red  heat  amnHinia  is  decouipo.s<Al  into  a  mixture 
^Jf  N  and  H,  occupying  double  the  volume  of  the  original  gas.  It  is 
similarly  decomposed  hy  the  prolonged  passage  through  it  of  dis- 
charges of  electricity.  It  is  not  readily  i'ombuKtible,  yet  it  burns  in  an 
iitinosphere  of  O  with  a  yellowish  tiarue.  Mixtures  of  XHa  with  O, 
nitrogen  monoxid,  or  nitrogen  dioxid,  explode  on  eontaet  with  fiame. 

The  solution  of  annnonia  in  H:;0  constitutes  a  strongly  alkaline 
liqnid,  know^n  as  aqua  ammontse,  which  is  possessed  of  strongly  basic 
J>ro|f)erties.  It  is  neutralized  by  acids  with  the  formation  of  crystal- 
line salts,  which  are  also  fonned,  without  liberation  of  hydrogen,  by 
dir^ot  nnion  of  gaseous  NH3  with  acid  vapors.  The  animoniacal  salts 
«ia»lthe  alkaline  base  in  aqua  ammonite  are  compounds  of  a  radical, 
*nimonium,  NHi^  which  forms  compounds  corresponding  to  those  of 
NaKsinm  or  sodinm.  The  compound  formed  by  the  union  of  txin- 
JifMiiH  and  water  is  ammonium  hydroxid,  X^H4liO  :  NH:i+lLjO= 
^'H^HO  ;  and  that  formed  by  the  nnion  of  hydrochloric  acid  and 
«f"Tnonia  is  ammonium  chlorid,  NH4CI:   NHa+HCl=NH4CL 

A  Very  delicate  test  for  ammonia  is  Nessler's  reagent.  This  is 
ttiBile  by  dissolving  35  grn.  of  potassium  iodid  and  13  gm.  of  mercuric 
eWorld  in  800  cc.  H^jO.  A  cold,  saturated  solution  of  mercuric 
**Worirl  is  then  added,  drop  by  drop,  until  the  red  precipitate  formed 
^'^^  longer  i^dissolves  on  agitation;  160  gm.  of  potassium  hydroxid 


152 


MANTJAL    OF    CHEMISTRY 


are  theu  dissolved  in  the  liquid,  which  is  finally  made  up  to  1000  < 
It  gives  a  yellow  color  with  a  mere  trace  of  NH:i,  and  a  red -brown 
preeipitrtte  with  a  larger  amount. 

Hydrazin — Diamid — lI-N.NHs — is  obtained  by  heating  its  liy*l| 
droxid  with  ao hydrous  BaO,  or  by  decomposing  its  ehlorbydrate  with  "' 
sodium  inethylate.  It  is  a  liquid,,  b.p*  113. 5*^,  which  does  not  attack 
ghiss,  sp.  gr.  1.014.  Mixes  with  water  and  with  alcohols.  It  is  quite 
stable,  and  only  decomposes  at  350^ :  3N2H4=N:i+4NH3.  It  is  a  power- 
ful reducing  agent,  and  reacts  violently  with  easily  reducible  ox  ids  and 
with  oxidizHig  agents  It  ignites  in  chlorin,  and  burns  in  air  with  a 
blue  flame.  It  forms  a  hyth-oxid  and  salts,  corresponding  to  those  of 
ammonium,  in  which  one  X atom  is  quinquivalent:  HtiN.N  11:^011.  Thefl 
hydroxid  is  obtained  by  distilling  the  sulfate  with  KHO  in  an  appara- 
tus entirely  of  silver.  It  is  a  colorless  liquid  which  when  cold  attacks 
cork  and  rubber,  and  glass  when  heated.  It  mixes  with  water  or  alcohol 
in  all  proportions,  hut  not  with  ether.  It  is  an  extremely  powerful 
reducing  ngeut:  II;;N.NHaOH  +  02  =  Ni:+3HjO,  and  explodes  with 
easily  reducible  oxids.  The  sulfate,  from  wliicb  the  hydrate  is  obtained^ 
is  formed  in  several  reactions,  mostlj-  with  organic  compounds,  as  from 
triazoacetic  acid,  and  from  gnaoidin  (q.  v.).    It  is  an  active  poison, 

Hydrazoic   Acid^Azoimid — X3II — is    a    sul>stance    recently    ob«^ 
tained  from  benzoyl -azoimid,  wiiicb,  although  containing  the  same' 
elements  as  ntnmouia,  is  rlistinctly  acid  in  character.    It  is  a  eoloi^ess 
liquid,  boiling  at  37*^   (98.C°F.),  bavifig  a  very  pungent  and   un- 
pleasant  odor.     It   is   extremely   unstable    and    explodes    with    great 
violence.    It  reacts  with  metals,  oxids,  and  hydroxids,  as  does  hydro-H 
chloric  acid,  to  form  nitrids,  which,  like  the  free  acid,  are  very  explo- 
sive.   It  is  a  very  active  poison. 

Hydroxylamin — NH2HO— 33.— The  amins  and  amids  (q.  v,)  areH 
compounds  derived  from  ammonia  by  tlie  sul)stitution  of  radicals  for 
a  pari  or  all  of  its  hydrogen.     This  substance,  Avliicb  is  intermediate 
in  composition  between  aninioiiia  and  anunonium  hydroxide  may  ba^ 
crmsidei'cd  as  ammonia,  one  of  whose   hydrogen  atoms  has  been  re- 
placed by  the  radical  hydroxyl,  HO.    It  is  obtained  in  aqueous  solu- 
tion by  the  union  of  nascent  hydrogen  with   nitrogen  dioxid:  N0+ 
H;t=NH2H0;   or  by  the  action  of  nascent  hydrogen  upon  nitric  acid: 
HN03+3H2^2HtiO+NH2HO.     Hydroxylamin  has  been  obtained  iu 
colorless,  hygroscopic    crystals,  fusing  at  33°  (91.4°  F.).  by  syste- 
matic rcctLfication  of  the  methyl  alcohol  solution  under   diminished 
pressure,  and  by  distillation  of  the  2n  double  salt,  ZnCb,  2NHuOH 
with  anilin.     Its  aqueous  solution,  which  probably  contains  the  cor-  M 
responding  hydroxid,  NHgO,  HO,  is  strongly  alkaline  and  behaves  m 
with  regard  to  acids  as  does  ammonium  hydi'oxid  solution,  forming 
salts  corresponding  to  those  of  ammonium.     Thus  hydroxyl  -  ammo- 


KITROGEN 


153 


ninm  chlorid,  XH^OCl,  crystallizes  in  prisms  or  tables,  fusible  at 
100"^  (212°  FJ,  and  decompoHed  into  HCU  H.'O  and  NH4C!  at  a 
slightly  bigber  temperature.  It  is  a  very  powerful  reducing  agent. 
Hydroxy lamraoninm  chlorid  has  been  used  in  the  treatment  of 
I'utaneons  disorders.  It  is  an  actively  toxic  agent,  (-*(mvertiug  oxy- 
haemoglobin  into  nietba^inoglobin. 

Compounds  of  Nitrogen  with  the  Halogens, — Nitrogen  Chlorid 
— NCI3 — 120.5 — is  formed  by  the  action  of  excess  of  CI  ojion  NH:{  or 
an  araraoniaeal  compound.  It  is  an  oily,  light-yellow  li^ptid  ;  sp.  gr. 
1.653;  has  been  distilled  at  71*'  (159.8  FJ.  When  heated  to  96^ 
(2(H,8'^P.),  when  subjected  to  concussion,  or  when  brought  in  eon- 
tact  with  phosphorus,  alkalies  or  greasy  niattei^^  it  is  decomposed, 
with  a  vmlent  explosion,  into  one  volume  N  and  three  volumes  CI, 

Nitrogen  Bromid. — ^NBra^254-^has  been  obUiined  as  a  reddish- 
brown,  syrupy  liquid,  very  volatile,  and  resend>ling  the  chlorid  in  its 
properties,  by  the  action  of  potassium  broinid  upon  nitrogen  eblorid. 
Nitrogen  lodid, — NI3 — 305 — When  iodin  is  lironp'hl  in  contact 
*ith  ammoniTin]  bydroxid  solution,  a  dark  brown  or  black  powder, 
highly  explosive  when  dried,  is  formed.  This  substance  varies  in 
t'omposition  according  to  the  conditions  under  which  the  action 
"^urs;  soraetimes  the  iodid  alone  is  formed;  under  other  circum- 
stam-os  it  is  mixed  with  compounds  containing  N,  I,  and  H. 

Oxids  of  Nitrogen. — Five  are  known,  forming  a  regular  series: 
K2O,  NO,  N2O3,  N2O4,  X'jO^.  Of  these  two,  the  trioxid,  N2O3,  and 
pentoxid»  NaOsi  are  anhydrids. 

Nitrogen  Monoxid. — Nitrous  oxid — IjuigMng  gas — Nitrogen  pro- 
hrid  —  X  L*0  —  Mo  If  c  H  la  r  we  tg  h  t  ^  44 —  Sp.  r/  r .  =  1 . 5  2  7  A — Fh  sea  a  t 
-mf{—UST.)— Boils  o/— 87°  (— 124''  F.)—Disrorfrfti in  lllBhy 

Preparation. — By  heating  ammonium  nitrate:  {NIl4)N0a=NM0+ 
2IliO.  To  obtain  a  pure  product  theiie  sliould  be  no  ammonium 
<*Horid  present  (as  an  impurity  of  the  nitrate),  and  the  beat  should 
^'applied  gradually,  nnd  not  allowed  to  exceed  250°  (482*"  Fj,  and 
^^^  gas  formed  should  he  passed  through  wash -bottles  eoutaining 
^'^^lintn  bydroxid  and  ferrous  sulfate. 

Properties,  —  PltysifoL  —  A  colorless,  odorless  gas,  huving  a 
'h  taste;  soluble  in  H2O;  more  so  in  alcohol.  Under  a  pres- 
et 30  atmospheres,  at  0"*  {32*^  F.).  it  forms  a  colorless,  mobile 
l^qtiid  which,  when  dissolved  in  carbon  disulfid  and  evaporated  in 
^<^ffo,  produces  a  cold  of  —140°  (—220''  FJ . 

OifmicaL — It  is  decomposed  by  a  red  heat  and  hy  the  continuous 
pa**ag€  of  electric  sparks.  It  is  not  conjbustible,  but  is,  after 
W)-gen»  the  best  supporter  of  combustion  known. 


154  MANUAL    OF    CHEMISTKY 

Physiological. — Althongh,  owing  to  the  readiness  with  which 
N2O  is  decomposed  into  its  constituent  elements,  and  the  nature  and 
relative  proportions  of  these  elements,  it  is  capable  of  maintaining 
respiration  longer  than  any  gas  except  oxygen  or  air,  an  animal  will 
live  for  a  sliort  time  only  in  an  atmosphere  of  pure  nitrons  oxid. 
When  inhaled,  diluted  with  air,  it  produces  the  effects  first  observed 
by  Davy  in  1799:  first  an  exhilaration  of  spirits,  frequently  accom- 
panied by  laughter,  and  a  tendency  to  muscular  activity,  the  patient 
sometimes  becoming  aggressive;  afterward  there  is  complete  anaes- 
thesia and  loss  of  consciousness.  It  has  been  much  used,  by  dentists 
especially,  as  an  anaesthetic  in  operations  of  short  duration,  and  in 
one  or  two  instances  anaesthesia  has  been  maintained  by  its  use  for 
nearly  an  hour. 

A  solution  in  water  under  pressure,  containing  five  volumes  of 
the  gas,  is  sometimes  used  for  internal  administration. 

Nitrogen  Dioxid. — Nitric  oxid — NO — Molecular  weight=30 — Sp. 
^r.=1.039  A— Discovered  by  Hales  in  1772. 

Preparation. — By  the  action  of  copper  on  moderately  diluted 
nitric  acid  in  the  cold:  3Cu+8HN03=3Cu(N03)2+4H20+2NO;  the 
gas  being  collected  after  displacement  of  air  from  the  apparatus. 

Properties. — A  colorless  gas,  whose  odor  and  taste  are  unknown; 
very  sparingly  soluble  in  H2O;  more  soluble  in  alcohol.  The  sp.  gr.  of 
the  gas  has  been  determined  at — 100°  ( — 148°F.)  and  has  been  found 
to  be  same  as  at  the  ordinary  temperature.  This  fixes  the  molecular 
weight  at  30  and  gives  the  formula  NO,  which  is  difficult  to  reconcile 
with  the  theory  of  valence.  Were  the  formula  doubled  the  consti- 
tution of  this  gas  could  be  thus  expressed  :  0=N — N=0.  (See 
Nitrogen  tetroxid.) 

It  combines  with  O,  when  mixed  with  that  gas  or  with  air,  to 
form  the  reddish  brown  nitrogen  tetroxid.  It  is  absorbed  by  solu- 
tion of  ferrous  sulfate,  to  which  it  communicates  a  dark  brown  or 
black  color.  It  is  neither  combustible  nor  a  good  supporter  of  com- 
bustion, although  ignited  C  and  P  continue  to  burn  in  it,  and  the 
alkaline  metals,  when  heated  in  it,  combine  with  its  O  with  incan- 
<1escence. 

Nitrogen  Trioxid. — Nitrous  anhydrid — N2O3 — 76 — Is  prepared  by 
the  direct  union  of  nitrogen  dioxid  and  oxygen  at  low  temperatures, 
or  by  decomposing  liquefied  nitrogen  tetroxid  with  a  small  quantity 
of  H2O  at  a  low  temperature:  4N02+H20=2HN03+N203.  It  is  k 
dark  indigo-blue  liquid,  which,  boiling  at  about  0°  (32°  F.),  is  partly 
decomposed.     It  solidifies  at  —82°  (—115.6°  F.) . 


NITROGEN  155 

Nitrogen  Tetroxid. — Nitrogen  peroxid — Hyponiiric  acid — Nitrous 
fumes— ^20a  — Molecular  weight=92— Boils  at  22°  (71.6° -F.)  — 
Solidifies  at  9°  (15.8°  F.). 

Preparation. — (1)  By  mixing  one  volume  O  with  two  volumes 
NO;   both  dry  and  ice-cold. 

(2)  By  heating  perfectly  dry  lead  nitrate,  O  being  also  produced: 
2Pb(N03)2=2PbO+4N02+02. 

(3)  By  dropping  strong  nitric  acid  upon  a  red-hot  platinum  sur- 
face. 

Properties. — When  pure  and  dry,  it  is  an  orange-yellow  liquid  at 
the  ordinary  temperature;  the  color  being  darker  the  higher  the 
temperature;  the  gas  is  red- brown,  but  becomes  colorless  at  about 
500°  (932°  P.).  The  red  fumes,  which  are  produced  when  nitric 
acid  is  decomposed  by  starch  or  by  a  metal,  consist  of  N2O4,  mixed 
with  N2O3.  The  sp.  gr.  of  the  gas  varies  with  the  temperature  and 
pressure.  Values  varying  from  29.23  to  39.9  have  been  obtained 
(H=l).  The  molecular  formula,  NO2,  calls  for  sp.  gi\  23;  N2O4  for 
46.  These  variations  are  due  to  the  fact  that  the  gas  is  dissociated 
(p.  90)  at  comparatively  low  temperatures.  The  formula  N2O4  has 
been  fixed  as  the  correct  one  by  the  method  of  Raoult  (see  p.  68). 
It  dissolves  in  nitric  acid,  forming  a  dark  yellow  liquid,  which  is  blue 
or  green  if  N2O3  be  also  present.  With  SO2  it  combines  to  form  a 
solid,  crystalline  compound,  which  is  sometimes  produced  in  the 
manufacture  of  H2SO4.  This  substance,  which  forms  the  lead  cham- 
ber crystals,  is  a  substituted  sulfurous  acid,  nitrosulfonic  acid, 
NO2SO2OH  (see  sulfonic  acids).  A  small  quantity  of  H2O  decom- 
poses N2O4  into  HNO3  and  N2O3,  which  latter  colors  it  green  or  blue. 
A  larger  quantity  of  H2O  decomposes  it  into  HNO3  and  NO.  By 
bases  it  is  transformed  into  a  mixture  of  nitrite  and  nitrate: 
2NO2+2KH0=KN02+KN03+H20. 

It  is  an  energetic  oxydant,  for  which  it  is  largely  used.  With 
certain  organic  substances  it  does  not  beliave  as  an  oxydant,  but 
becomes  substituted  as  an  univalent  radical;  thus  with  benzene  it 
tfomis  nitro- benzene:   C6H5(N02). 

Toxicology. — The  brown  fumes  given  off  during  many  processes, 
in  which  nitric  acid  is  decomposed,  are  dangerous  to  life.  All  such 
operations,  when  carried  on  on  a  small  scale,  as  in  the  laboratory, 
^should  be  conducted  under  a  hood  or  some  other  arrangement,  by 
which  the  fumes  are  carried  into  the  open  air.  When  in  industrial 
processes  the  volume  of  gas  formed  becomes  such  as  to  be  a  nuisance 
when  discharged  into  the  air,  it  should  be  utilized  in  the  manufacture 
of  H2SO4,  or  absorbed  by  H2O  or  an  alkaline  solution. 

An  atmosphere  contaminated  with  brown  fumes  is  more  dangerous 


156 


MANUAL    UF    CHEMISTRY 


than  one  containing  CI,  as  the  presence  of  the  latter  is  more  imme- 
diately annoying.  At  first  there  is  only  coughing,  and  it  is  only  two 
to  four  hours  later  that  a  diffleiilty  in  breathing  is  felt,  death  occur- 
ring in  ten  to  fifteen  hours.  At  the  autopsy  the  luugfs  are  found  to 
be  extensively  disorganized  and  filled  with  black  fluid. 

Even  air  containing  small  quantities  of  brown  fumes,  if  breathed 
for  a  long  time,  produces  chronic  disease  of  the  respiratory  organs. 
To  prevent  suuh  aecideuts,  thorough  ventilation  in  locations  where 
brown  fumes  arc  liable  to  be  formed  is  imperative.  In  cases  of  spill- 
ing nitric  acid,  safety  is  to  be  sought  in  retreat  from  the  apartment 
until  the  fumes  have  been  I'cplaeed  by  pure  air  from  without. 

Nitrogen  Pentoxid, — Nfirir  anhpdrtd — N2O5 — MoUcular  weigh t=^ 
lOS—Fitses  at  30^  {HB''  F.)—Bons  at  47''  (IIG.G'^  F J . 

Preparation,— (1)  By  decomposing  diy  silver  nitrate  with  dry 
CI  in  an  apparatus  entirely  of  glass :  4AgN03+2Cl2"4AgCl+ 
2N2O5+O2. 

(2)  By  removing  water  from  fuming  nitric  acid  w*ith  phosphorus 
pentoxid :   6HN0:i+  P-Or,=2H;iP04+3N205. 

Properties.^Prismatic  crystals  at  temperatures  above  30^  (86*^ 
Fj.  It  is  very  unstable,  being  decomposed  by  a  heat  of  50^  (122^ 
F.);  on  contact  with  H2O,  with  which  it  forms  nitric  acid;  and  even 
spontaneously.  Most  substances  w^hich  combine  readily  with  O 
remove  that  element  from  N2O5. 

Nitrogen  Acids, ^Three  are  known,  either  free  or  in  combination, 
corresponding  to  the  three  oxids  containing  uneven  numbers  of  O 
atoms: 

NuO  -fH.O— 2HNO— HypOHitrous  acid. 
'  N20a+HiO=2HNO-— Nitruus  iii^id, 

N:t05+H20=2HNOj— Nitncj  aeid. 


Hyponitrous  Acid  —  HNO^- 31  — Known  only  in  combination. 
Sodium  hji)onitrite  is  formed  by  the  action  of  sodium  upou  sodium 
nitrate,  or  nitrite:  NaN03+4Na+2H20^NaNO+4NaHO.  Silver 
hyponitrite  is  formed  by  n^dnction  of  sodium  nitrate  by  nascent  H 
and  decomposition  with  silver  nitrate. 

Nitrous  Acid — MttitnifroHa  acid — HNO2 — 47 — ^bas  not  been  iso- 
lated, although  its  salts,  the  nitrites,  are  well-defined  compounds: 
M'NO-or  M''(N02)2. 

The  nitrites  occur  in  nature,  in  small  quantity,  in  natural  waters, 
whei*e  they  result  from  the  decomposition  of  nitrogenous  organic  sub- 
stances; also  in  saliva.  They  are  produced  by  heating  the  corre- 
sponding nitrate,  either  alone  or  in  the  presence  of  a  readily  oxidizable 
metnl,  such  as  lead.     Solutions  of  the  nitrites  are  readily  decomposed 


NITROGEX 


i: 


by  the  mineral  acids,  with  evolution  of  brown  fumes.  They  take  up 
oxygen  readily  and  are  hence  used  as  reducing  agents.  Solutions  of 
pota^isium  permanganate  are  instantly  decolorized  by  nitntes,  A 
uiijtture  of  thin  starch  paste  and  zinc  iodid  solution  is  colored  bine 
by  nitrites,  which  decompose  the  iodid,  liberating  the  iodin.  A  solu- 
tion of  metapheiiyleudiatniu,  in  the  presence  of  free  acid,  is  colored 
brown  by  very  minute  traces  of  a  nitrite,  the  color  being  due  to  the 
jation  of  triamido*azobenzene  (Bismark  brown}. 

Nitric  Acid,  Aquafortis — Ilfjdrofjen  nifrttfe — Acidum  nitricum 
—U.S.;  Br.— I1X0j-'(]3. 

Preparation, —  (1)  By  the  direct  union  of  its  constituent  elements 
finder  the  influence  of  electric  discharges. 

(2)  By  the  decomposition  of  an  alkaline  nitrate  by  strong  H2SO4. 
With  moderate  heat  a  portion  of  the  acid  is  liberated.  2NaN03+ 
H2SOi=XaHS04+NaNOa+HXO:t.  and  at  a  higher  teniperatnre  the 
remainder  is  given  off:  NaN03+XaliSO.i=Na2S04+HN03.  This  is 
the  reaction  used  in  the  mannfactui'e  of  HXO3- 

Varicties, — Commercial — a  yellowish  liquid,  impure,  and  of  two 
degrees  of  concentration:  single  aquafortis ;  sp.  gr.  about  1.25=39% 
HXO3;  and  double  aquafortis;  sp.  gr.  about  1.4^=64%  HXO:». 
Fuming — a  reddish  yellow  liquid,  more  or  less  free  from  impurities; 
charged  with  oxids  of  nitrogen.  Sp.  gr.  about  1.5.  Used  as  a!i 
oxidizing  agent.  €.  P. — a  colorless  liquid,  sp.  gr.  L522,  which 
should  respond  favorably  to  the  tests  given  below.  Aeidum  nitri- 
cum, U.  S.;  Br.— a  colorless  acid,  of  sp.  gr.  1.42=70%  HNO3. 
Acidum  nitricum  dilutum,  IT.  S.;  Br. — the  last  mentioned,  diluted 
With  H'^O  to  sp.  gr.  1.059=109!?  HXOj  (U.  8.),  or  to  sp.  gr.  1.101= 
17.44%  HXO,  (Br  ). 

Properties* — PhijsfeaL — ^The  pure  aeid  is  a  eolorless  liquid:  sp. 
gr.  1.522:  boily  at  86°  (186.8°  F.};  solidifies  at  —40°  (— 40°F.); 
^ves  off  white  fumes  in  damp  aii';  and  has  a  strong  acid  taste  and 
reaction.  The  sp.  gr,  and  boiling  point  of  dilute  acids  vary  with  the 
eoneentration.  If  a  strong  acid  be  distilled,  the  boiliug*point  grad- 
ually rises  from  8G°  {186.8''  FJ  until  it  reaches  123°  (253.4°  F.), 
wbeu  it  remains  eonstant,  the  sp,  gr.  of  distilled  and  distillate  being: 
1.42=70%  HNO3.  If  a  weak  acid  be  taken  orig'inally  the  boiliugr 
point  rises  until  it  liecomes  stationary  at  the  same  point. 

ChemkaL — When  exposed  to  air  and  light,  or  when  strongly 
heAted,  HNOa  is  decomposed  into  Nj04;  H2O  and  O.  Nitric  aeid  is 
a  valuable  oxydant;  it  converts  I,  P,  S,  C»  B,  and  Si  or  their  lower 
oxids  into  their  highest  oxids;  it  oxidizes  and  di*stroys  most  organic 
substances,  although  with  some  it  forms  products  of  substitution. 
Most  of  the  metals  dissolve  in  HNO3  as  nitrates^  a  portion  of  the 


158  MANUAL    OF    CHEMISTRY 

acid  being  at  the  same'time  decomposed  into  NO'arid  H207'4HN03+ 
')Ag=3AgN03+NO+2H20.  The  chemical  activity  of  HNO3  is  much 
reduced,  or  even  ahuost  arrested,  when  the  intei*vention  of  nitrous 
acid  is  prevented  by  the  presence  of  carbamid.  The  so-called  ''noble 
metals,"  gold  and  platinum,  are  not  dissolved  by  either  HNO3  or 
HCl,  but  dissolve  as  chlorids  in  a  mixture  of  the  two  acids,  called 
aqua  regia.  In  this  mixture  the  two  acids  mutually  decompose  each 
other  according  to  the  equations  :  HN03+3HCl=2H20+NOCl+Cl2 
and  2HN03+6HCl=4H20+2NOCl2+Cl2  with  formation  of  nitrosyl 
chlorid,  NOCl  and  bichlorid,  NOCI2,  and  nascent  CI;  the  last  named 
combining  with  the  metal.  Iron  dissolves  easily  in  dilute  HNO3,  but 
if  dipped  into  the  concentrated  acid,  it  is  rendered  passive,  and  does 
not  dissolve  when  subsequently  brought  in  contact  with  the  dilute 
acid.  This  passive  condition  is  destroyed  by  a  temperature  of  40^ 
(104°  P.)  or  by  contact  with  Pt,  Ag  or  Cu.  When  HNO3  is  decom- 
posed by  zinc  or  iron,  or  in  the  porous  cup  of  a  Grove  battery,  N2O3 
and  N2O4  are  formed,  and  dissolve  in  the  acid,  which  is  colored  dark 
yellow,  blue  or  green.  An  acid  so  charged  is  known  as  nitroso-nitric 
acid.     Nitric  acid  is  monobasic. 

Impurities. — Oxids  of  nitrogen  color  the  acid  yellow:  H2SO4  gives 
a  white  ppt.  with  BaCk;  CI,  a  white  ppt.  with  AgNOs;  and  Pe  a  red 
color  with  ammonium  thiocyanate.  Dilute  the  acid  with  two  volumes 
of  water  before  testing.  Salts  leave  a  solid  residue  when  the  acid  is 
evaporated  in  platinum. 

Nitrates. — The  nitrates  of  K  and  Na  occur  in  nature.  Nitrates 
are  formed  by  the  action  of  HNO3  on  the  metals,  or  on  their  oxids  or 
carbonates.  They  have  the  composition  M'NOs,  M''(N03)2  or  M'" 
(N03)3,  except  certain  basic  salts,  such  as  the  sesquibasic  lead- 
nitrate,  Pb  (N03)2,  2PbO.  With  the  exception  of  a  few  basic  salts, 
the  nitrates  are  all  soluble  in  water.  When  heated,  they  fuse  and  act 
as  powerful  oxidants.  They  are  decomposed  by  H2SO4  with  libera- 
tion of  HNO3. 

Analytical  Characters. — As  the  nitrates  are  all  soluble,  there  is 
no  precipitation  reaction  for  the  anion  NO3'',  and  recourse  is  had  to 
color  reactions:  (1)  Add  an  equal  volume  of  concentrated  H2S04r 
cool,  and  float  on  the  surface  of  the  mixture  a  solution  of  FeS04. 
The  lower  layer  becomes  gradually  colored  brown,  black,  or  purple,, 
beginning  at  the  top. 

(2)  Boil  in  a  test-tube  a  small  quantity  of  HCl,  containing" 
enough  sulflndigotic  acid  to  communicate  a  blue  color,  add  the  sus- 
pected solution  and  boil  again;   the  color  is  discharged. 

(3)  If  acid,  neutralize  with  KHO,  evaporate  to  dryness,  add  to 
the  residue  a  few  drops  of  H2SO4  and  a  crystal  of  brucin  (or  some 
sulfanilic  acid) ;  a  red  color  is  produced. 


PHOSPHORUS  159 

(4)  Add  H2SO4  and  Cu  to  the  suspected  liquid  and  boil,  browa 
fumes  appear  (best  visible  by  looking  into  the  mouth  of  the  test  tube) . 

(5)  A  solution  of  diphenylamin  in  concentrated  H2SO4  (.01  grm. 
in  100  cc.)  is  colored  blue  by  nitric  acid.  A  similar  color  is  produced 
by  other  oxidizing:  ajjents. 

(6)  To  0.5  cc.  nitrate  solution  add  one  drop  aqueous  solution  of 
resorcinol  (10%),  and  1  drop  HCl  (15%),  and  float  on  the  surface  of 
2  cc.  concentrated  H2SO4;  a  purple-red  band. 

Toxicology. — Although  most  of  the  nitrates  are  poisonous  when 
taken  internally  in  sufficiently  large  doses,  their  action  seems  to  be 
due  rather  to  the  metal  than  to  the  acid  radical.  Nitric  acid  itself  is 
one  of  the  most  powerful  of  corrosives. 

Any  anim&l  tissue  with  which  the  concentrated  acid  comes  in  con- 
tact is  rapidly  disintegrated.  A  yellow  stain,  afterward  turning 
to  dirty  brownish,  or,  if  the  action  be  prolonged,  an  eschar,  is  formed. 
When  taken  internally,  its  action  is  the  same  as  upon  the  skin,  but 
owing  to  the  more  immediately  important  function  of  the  parts,  i» 
followed  by  more  serious  results  (unless  a  large  cutaneous  surface  be 
destroyed). 

The  symptoms  following  its  ingestion  are  the  same  as  those  pro- 
duced by  the  other  mineral  acids,  except  that  all  parts  with  which  the 
acid  has  come  in  contact,  including  vomited  shreds  of  mucous  mem- 
brane, are  colored  yellow.  The  treatment  is  the  same  as  that  indi- 
cated when  H2SO4  or  HCl  have  been  taken,  i.  e.,  neutralization  of 
the  corrosive  by  magnesia  or  soap,  and  dilution. 

PHOSPHORUS. 

Symbol=P— Atomic  weight=31  (0=16;31;  H=l : 30.74)— iifo7ec- 
ular  tceight^=124k  (P4) — 8p.gr.  of  vapor=4 .2904  A-— Name  from  <l>^ 
=lfght,  4>^piix=I  bear — Discovered  by  Brandt  in  1669 — Phosphorus 
(U.  S.;  Br.). 

Occurrence. — Only  in  combination;  in  the  mineral  and  vegetable 
worlds  as  phosphates  of  Ca,  Mg,  Al,  Pb,  K,  Na.  In  the  animal 
kingdom  as  phosphates  of  Ca,  Mg,  K  and  Na,  and  in  organic  com- 
bination. 

Preparation. — From  bone-ash,  in  which  it  occurs  as  tricalcic 
phosphate.  Three  parts  of  bone -ash  are  digested  with  2  parts  of 
strong  H2SO4,  diluted  with  20  volumes  H2O,  when  insoluble  calcie 
Fulfate  and  the  soluble  monocalcic  phosphate,  or  " superphosphate, '^ 
are  formed:  Ca3(P04)2+2H2S04=H4Ca(P04)2+2CaS04.  The  solu- 
tion of  superphosphate  is  filtered  off  and  evaporated,  the  residue  is 
mixed  with  about  one -fourth  its  weight  of  powdered  charcoal  and 


MANUAL 


lEMISTBY 


sand,  and  the  mixture  heated,  first  to  redness,  finally  to  a  white  heat, 
in  earthenware  retorts,  whose  heaks  dip  under  water  in  snitablo 
receivers.  During  the  fii*st  part  of  the  heating  the  monocalcie  phos- 
phate is  converted  into  metaphosphate  :  CaHi(P04)2=Ca(P03)2+ 
2H2O;  which  is  in  turn  reduced  by  the  charcoal,  with  formation  of 
carbon  monoxid  and  liberation  of  phosphonis,  while  the  calcium  is 
combined  as  silicate:   2Ca(PO;j)2+2SiO2+5C2=2Ca8iOa+10CO+P4. 

A  direct  electric  process  has,  in  great  part,  replaced  the  above 
industrially.  A  mixture  of  phosphate,  carbon  and  flux  is  heated  in  a 
closed  electric  furnace  provided  wnth  a  condenser.  The  process  is 
continuous  and  avoids  the  use  of  Hi'SO^, 

The  crude  product  is  purified  by  fusion,  first  under  a  solution  of 
1  teaching  powder,  next  under  ammoniacat  H2O,  and  finally  under 
water  containing  a  small  quantity  of  H^iSO^  and  potassium  diehroniate. 
It  is  then  strained  through  leather  and  cast  into  sticks  nnder  warm 
H2O. 

Properties,^ — PA i^^rm?.— Phosphorus  is  capable  of  existing  in  four 
allotropie  forms: 

(1)  Ordinary,  or  yellow  variety,  in  which  it  usually  occurs  in  com* 
merce.  This  is  a  yellowish,  translucid  solid,  of  the  consistency  of 
wax.  Below  0°  {32°  P.)  it  is  brittle;  it  fuses  at  44.3°  (111.7"  F.) ; 
and  boils  at  290°  (554°  F.)  in  an  atmosphere  not  capable  of  acting 
upon  it  chemically.  Its  vapor  is  colorless;  sp.  gr.^4.5A — 65  H  at 
1040°  (1940''  FJ.  It  volatilizes  below  its  boiling  point,  and  H2O 
Iwiled  upon  it  gives  off  steam  charged  with  its  vapor.  Exposed  to 
air  it  gives  off  white  fumes  and  produces  ozone.  It  is  luminous  in 
the  dark.  It  is  insoluble  in  H2O;  sparingly  soluble  iu  ah^ohol,  more 
soluble  in  ether;  soluble  in  carbon  disulfid,  and  in  the  fixed  and 
volatile  oils.  It  crystallizes  on  evaporation  of  its  solutions  in  octa- 
hedrod  or  dodecahedrfe,     8p.  gr.  1.83  at  10^  (50°  F.), 

(2)  m^ite  phoiiphorus  is  formed  as  a  white »  opaque  pellicle  upon 
the  surface  of  the  ordinary  variety,  when  this  is  exposed  to  light 
under  aerated  H2O.  Hp.gr,  1.515  at  15°  (59°F.).  When  fused  it 
reproduces  ordinary  phosphorus  without  loss  of  weight. 

(3)  Black  variHy  is  formed  when  ordinary  phosphorus  is  heated 
to  70°  (158°  F.)  and  t^uddeuly  cooled. 

(4)  Red  variety  is  produced  from  the  ordinary  by  maintaining  it 
at  from  240°  (464°  FJ  to  280''  (536°  F.)  for  two  or  three  days,  m 
an  atmosphere  of  carbon  dioxid;  and,  after  cooling,  washing  out  th^ 
unaltered  yellow  phosphorus  with  carbon  disulfid.  It  is  also  formed 
upon  the  surface  of  the  yellow  variety,  Tivhen  it  is  exposed  to  direct 
sunlight. 

It  is  a  reddish,  odorless,  tasteless  solid,  which  does  not  fume  in 
air,  nor  dissolve  in  the  solvents  of  the  yellow  variety.     Sp.  gr,  2.1, 


PHOSPHOBtrS 


» 


Heated  to  500''  (932"^  F  J  with  lead,  in  the  absence  of  air.  it  dissolves 
in  the  moltcm  metal,  from  which  it  separates  on  coolingr  in  violet- 
hlack,  rbomboh^drat  crystals,  of  sp.  gx\  2.34.  If  prepared  at  250° 
(482*  F.)  it  fuses  below  that  temperature,  and  at  260°  (500°  F.) 
is  transformed  into  the  yellow  variety,  which  distils.  The  crystal- 
line product  does  not  fuse.  It  is  not  luminous  at  ordinary  tem- 
peratures. 

Ch^micaL — The  most  prominent  property  of  P  is  the  readiness 
uritlt  which  it  combines  with  O,  The  yello^w  variety  ig^nit4?s  and 
tiurns  with  a  bright  fiame  if  heated  in  air  to  60°  (140"^  P.),  or  if 
exposed  in  a  finely -divided  state  to  air  at  the  ordinary  temperature; 
with  formation  of  P2O3;  PiO:,-  IljPOa,  or  H11PO4,  according  as  0  is 
present  in  excess  or  not,  and  according  as  the  air  is  dry  or  moist. 
The  temperature  of  ignition  of  yellow  P  is  so  low  that  it  must  be 
preserved  under  boiled  water.  By  directing  a  f current  of  O  upon  it, 
r  may  be  burned  under  H/J,  heated  abo%^e  45'^  {IVf  PJ.  The  red 
variety  combines  with  0  much  less  readily,  and  may  be  kept  in  eon- 
fAct  with  air  without  danger. 

The  luminous  appearance  of  j-ellow  P  is  said  to  be  due  to  the 
formation  of  ozone.  It  does  not  occur  in  pure  O  at  the  ordinary 
trtnperature,  uor  in  air  under  pi*essnre^  nor  in  the  absence  of 
moisture,  nor  in  the  presence  of  miiiate  quantities  of  carbon  disulfid, 
oil  of  turpentine,  alcohol,  ether,  naphtha,  atid  many  gases. 

Yellow  phosphorus  burns  in  CI  with  formation  of  PCb  or  PCI5, 
rding  as   P  or   CI    is  present   in   excess.     Both  yellow  and  red 

ieties  combine  directly  with  CI,  Br,  and  I. 

Phosphorus  is  not  aetcd  on  by  11(1  or  cold  HiS04.  Hot  H-SO4 
oxidizes  it  with  formation  of  phosphorous  acid  and  sulfur  dioxid: 
Pi-r6H2S04  — 4KiPOn+6S02.  Nitric  acid  oxidizes  it  violently  to 
phosphoric  acid  and  nitrogen  di-  and  tetr-oxids:  12HNOa+P4= 
4H^P04+4N204+4NO. 

Phosphorus  is  a  reducing  agent.  When  immersed  in  cupric  sul* 
fate  solution,  it  becomes  covered  with  a  coating  of  metallic  copper.  In 
silver  nitrate  solution  it  produces  a  blaek  deposit  of  silver  phospbid. 

The  principal  uses  of  phosphorus  are  in  making  matches,  rat 
I)ai.Hte  and  phosphor  bronze. 

Toxicology, — The  red  variety  differs  from  the  other  allotropic 
forms  of  phosphorus  in  not  being  poisonous,  probably  owing  to  its 
ittsolnbility,  and  in  being  little  liable  to  cause  injury  by  burning. 

The  burns  produced  by  yellow  pbospborus  are  more  serious  than 
a  like  deatmction  of  cutaneous  surface  hy  other  substances.  A  burn- 
ing fragment  of  P  adheres  tenaciously  to  the  skin,  into  which  it 
burrows.  One  of  the  products  of  the  combustion  is  me ta phosphoric 
•irid   (q»  vj   which,    being  absorbed,    gives  rise  to  true    poisoning. 

L 


162 


MANUAL    OF    CHEMISTRY 


Burns  by  P  should  be  washed  immediately  with  dilute  javelle  water^ 
liq.  mdm  ehlorinat^,  or  solution  of  ehlorid  of  lime.  Yellow  P  should 
never  be  allowed  to  eome  iu  eootaet  will^  the  skiu,  except  it  be  under 
cold  water. 

Yellow  P  is  one  of  the  most  insidious  of  poisons.  It  is  taken  or 
administered  usually  as  "ratsbane"  or  mateh- heads.  The  fonuer  is 
frequently  starch  paste^  charged  with  phosphorus;  the  latter,  in  the 
ordinary  sulfur  match,  a  mixture  of  potassium  chlorate,  very  fiue 
sandf  phospliorns,  and  a  coloring  matter.  The  symptoms  in  acute 
phosphorus- poisonuig  appear  with  greater  or  less  rapidity,  according 
to  the  dose,  and  the  presence  or  absence  in  the  stomach  ol  substances 
which  favor  its  absorption.  Their  appearance  may  be  delayed  for 
days,  but  as  a  rule  they  appear  within  a  few  hours.  A  disagreeable 
garlicky  taste  iu  the  mouth,  and  heat  in  the  stomach  are  first  observed, 
the  latter  gradually  developing  into  a  burning  pain,  accompanied  by 
vomiting  0f  dark-colored  matter,  which »  when  shaken  in  the  dark,  is 
phosphoresceut ;  low  temperature  and  dilatation  of  the  pupils.  In 
some  cases,  death  follows  at  this  point  suddenly,  without  the  appear- 
ance of  any  further  marked  symptoms.  Usually,  however,  the 
patient  rallies,  seems  to  be  doing  well,  until,  suddenly,  jaundice 
makes  its  appearance,  accompauied  by  retention  of  urine,  and  fre* 
quently  delirium,  followed  by  coma  and  death. 

There  is  no  known  chemical  antidote  to  phosphorus.  The  treat- 
ment is,  therefore,  lifuitcd  to  the  removal  of  the  unabsorbed  portions 
of  the  poison  by  the  action  of  an  emetic,  ziuc  or  copper  sulfate,  or 
apomorphin,  as  expeditiously  as  possible,  and  the  administration  of 
French  oil  of  turpentine — the  older  the  oil  the  better — a^  a  physio- 
logical antidote.  The  use  of  fixed  oils  or  fats  is  to  be  avoided,  as 
they  favor  the  absorption  of  the  poison,  by  their  solvent  action. 
The  prognosis  is  very  unfavorable. 

Analysis. — ^Wheu,  after  a  death  supposed  to  be  caused  bj*  phos- 
phorus, chemical  evidence  of  the  existence  of  the  poison  in  the  body, 
etc.,  is  desired,  the  investigation  nuist  be  made  as  soon  after  death 
as  possible,  for  the  reason  that  the  element  is  rapidly  oxidized,  and 
the  detection  of  the  higher  stages  of  oxidation  of  phosphorus  is  of  no 
value  as  evidence  of  the  administration  of  the  element,  l>ecanse  they 
are  normal  constituents  of  the  body  and  of  the  food. 

The  detection  of  elementary  phosphorus  in  a  systematic  toxieo- 
logical  analysis  is  connected  with  that  of  prussie  acid,  alcolml,  ether^ 
chloroform,  and  other  volatile  poisons.  The  substances  under  ex- 
amination are  diluted  with  H^O^  acidulated  with  tartaric  acid  and 
lieated  over  a  sand-bath  in  the  flask  n  (Fig.  31)^  This  tiask  is  con- 
nected with  a  CO'2  generator,  c ,  whose  stopcock  is  closed,  and  with  a 
Liebig's  condenser,  e,  which    is   in  darkness  (the  operation  is  best 


PHOSPHORJS 


16a 


conducted  in  a  dark  room),  and  so  placed  as  to  deliver  the  distillate 
into  the  flask,/.  The  odor  of  the  distillate  is  noted.  In  the  presence 
of  P  it  is  usually  alliaceous.  The  condenser  is  also  observed.  If,  at 
the  point  of  greatest  condensation,  a  luminous  ring  be  observed  (in 
the  absence  of  all  reflections),  it  is  proof  positive  of  the  presence  of 
unoxidized  phosphorus.     The  absence,  however,  of  that  poison  is  not 


Fio.  81. 


to  l)€  inferred  from  the  absence  of  the  luminous  ring  (see  above).  If 
this  fail  to  appear,  when  one -third  the  fluid  contents  of  the  flask  a 
have  distilled  over,  the  condenser  is  disconnected,  and  in  its  place  th(> 
absorbing  apparatus,  Pig.  32,  partly  filled  with  a  neutral  solution  of 
silver  nitrate,  is  adjusted  by  a  rubber  tube,  and  a  slow  and  con- 
stant stream  of  CO2  is  caused  to  traverse  the  apparatus  from  c 
(Fi^.  31).  If,  during  continuation  of  the  distillation,  no  black 
deposit  be  formed  in  the  silver  solution,  the  absence  of  P  may  be 


164 


MAKXAL     OF    CHEMISTRY 


Pia.  32. 


inferred.     If  a  black  deposit  be  formed,  it  must  be  further  examined 
to  determine  if  it  be  silver  phosphid.     For  this  purpose  the  apparatus 

showD  ill  Pig.  33  is  used.  In  tlie  bottle  a 
hydrogen  is  generated  from  pure  Zu  and  H^SO^^ 
the  gas  passing  through  the  dryiug-tube  h,  filled 
with  fragraents  of  CaCUs  and  out  through  the 
platinum  tip  at  r;  d  and  e  are  pineh* corks. 
When  the  apparatus  is  filled  with  H,  d  is 
closed  until  the  fuunel*tube  /  is  three-quarters 
filled  with  the  liquid  from  a  ;  then  e  is  closed 
and  d  opened,  aud  the  black  silver  deposit, 
which  has  beeu  collected  on  a  filter  and  washed, 
is  thrown  into  /;  e  is  then  sliglitly  opened  and 
the  escaping  gas  ignited  at  c,  the  size  of  the 
flame  being  regulated  by  e.  It  the  deposit 
contain  P,  the  flame  will  have  a  green  color; 
and,  when  examined  with  the  spectroscope,  will 
give  the  spectrum  of  bright  bands  shown  in 
Fig.  34. 

Chronic  phosphorus  jjoisoning,  or  Lurifer  disease^  occurs  amoni^ 
operatives  engaged  in  the  dipping,  drying,  and  packing  of  phos- 
phorus matches.     Those  engaged  in  the  maun  fact  are  of  phosphorus 

itself  are  not  so  affected.  Sickly 
women  and  children  are  most 
subject  to  it.  The  cause  of  the 
disease  has  beeu  ascribed  to  the 
presence  of  arsenic,  and  to  the 
formation  of  ox  ids  of  phos* 
phorus,  and  of  ozone.  The  pro- 
gress of  the  disorder  is  slow,  aiid 
its  culminating  nianifestation  is 
the  destruction  of  one  or  both 
maxillte  by  necrosis. 

The  frequency  of  the  disease 
may  be  in  some  degree  dimin- 
ished hy  thorough  ventilation  of 
the  shops,  by  frequent  ivnshiug 
of  the  face  and  mouth  with  a 
weak  solution  of  sodium  carbon- 
ate, by  exposing  oil  of  turpentine  in  saucers  iu  the  workshops,  aud 
particularly  by  keeping  the  teeth  in  repair.  None  of  these  methods, 
however,  effect  a  perfect  prevention,  which  can  only  be  attained  by 
the  substitution  of  the  red  variety  of  phosphonis  for  the  yellow 
in  this  industrj'. 


FlO.  33. 


PH0HPH0KU8 


16G 


I 


Hydrogen  Phosphids**— Gaseous  hydrogen  phosphid— Phosphin 
— Fhosphonia,  Phospkamin,  PH^ — 34— a  colorless  gas,  liaviDg  a  strong 
alliaceoQS  odor,  which  is  obtaioed  pure  by  decomposing  phospho- 
ninm  iodid,  PH4I,  with  H2O.  Mixed  with  H  and  vapor  of  P2H4,  it 
is  produced,  as  a  spontaneously  inflammable  gas,  by  the  action 
of  hot,  concentrated  solution  of  potassium  hydroxid  on  P,  or  by 
decomposition  of  calcium  pbosphid  by  H2O.  It  is  highly  poison- 
ous. After  death,  the  blood  is  found  to  be  of  a  dark  violet  color, 
and  also  to  have»  in  a  great  measure,  lost  its  power  of  absorbing 
oxygen. 

Liquid  hydrogen  phosphid — P2H4— 66— is  the  substance  who^e 
vapor  communicates  to  PH3  its  property  of  igniting  on  contact  witli 
air.  It  is  separated  by  passing  the  spontaneously  inflammable  PH3 
through  a  bulb  tube,  surrounded  by  a  freezing  mixture. 


A  A  Be 

n 

1 

IL 

F 

& 

1 

II 
1 

4^ 

^^^1 

1  1  1  1 

J 

11 

^^^^^ 

1. 

1 

Flo.  34- 


■  It  is  a  colorless,  heavy  liquid,  which  is  decomposed  by  exposure 

■  to  Hunlight,  or  to  a  temperature  of  m""  (86''  F.). 

■  Solid  hydrogen  phosphid— P4H2 — 126 — is  a  yellow  solid,  formed 
p      when  PsHi  is  (leconi posed  by  suuliglit.     It  is  not  phossphoresceut  and 

•    only  i gii  i  tes  « t  1 60 ''  ( 320°  F . ) . 

■  Compounds  of  Phosphorus  with  the  Halogens  —  Phosphorus 
"     TricHloni--Pr):j — VHSr — Is  obtHiiied  by  h«'ating  P  in  a  liiiiited  supply 

of  CI*     It  is  a  colnrless  liquid;  sp.  gr.  1,61;  has  an  irritating  odor; 

Ifotiies  ill  air:  I>im1s  at  76*^  (169°  F.}.  Water  decomposes  it  with 
formation  nf  HjPOa  and  HCl. 
Phosphorus  Pentachlorid — PCls — 208.5 — is  formed  when  P  is 
burnt  in  excess  of  t*l.  It  is  a  light  yellow,  crystalline  solid  :  gives 
off  irritating  fumes:  and  is  decomposed  by  H2O. 
Phosphorus  Oxychlorid — POCb— 153.5 — is  formed  by  the  action 
of  a  limited  qnautity  of  II2O  on  the  pentachlorid:  PClfi+H20— POCU 
+2HCL  It  is  a  colorless  liquid:  sp.  gr,  LOT;  boils  at  110'"  (230°  F) ; 
aod  »olidi6es  at  -lO"*  (  +  14'"  FJ. 

With  bromtn  P  forms  componnds  similar  in  composition  and 
properties  to  the  chlorin  componnds.  With  iodin  it  forms  two  com- 
pounds, Pil«  and  PTri.  With  fluorin  it  forms  two  compounds,  PFj 
and  PF5,  the  former  liquid^  the  second  gaseous. 


166  MANUAL    OP    CHEMISTRY 

Oxids  of  Phosphorus.— Two  are  known:  P2O8  and  P2O6. 

Phosphorus  Trioxid. — Phosphorous  anhybrid^  Phosphorous  oxid — 
P2O3— 110 — is  formed  when  P  is  burned  in  a  very  limited  supply  of 
perfectly  dry  air,  or  O.  It  is  whit«,  flocculent  solid,  which,  on  ex- 
posure to  air,  ignites  by  the  heat  developed  by  its  union  with  H2O  to 
form  phosphorous  acid. 

Phosphorus  Pentoxid. — Phosphoric  anhydrid,  Phosphoric  oxid. 
— P2O5 — 142 — is  formed  when  P  is  burned  in  an  excess  of  dry  O.  It 
is  a  white,  flocculent  solid,  which  has  almost  as  great  a  tendency  to 
combine  with  H2O  as  has  P2O3.  It  absorbs  moisture  rapidly,  deli- 
quescing to  a  highly  acid  liquid,  containing,  not  phosphoric,  but 
metaphosphoric  acid.     It  is  used  as  a  drying  agent. 

Phosphorus  Acids. — Six  oxyacids  of  phosphorus  are  known  : 


Hypophosphorons  acid  : 

/0--H 
0=P— H 

\H 

Phospborons  acid: 

/O-H 
0=P-0— H 
\H 

Phosphoric  acid  : 

/0-H 

0=P-0— H 

\0-H 

/O— H 
0=P-0— H 

I^rrophosphoric  acid  : 

)o 

0=P— 0-H 
\0-H 

Metaphosphoric  acid  : 

/O-H 

o=p=o 

XO— H 
0=P-0-H 

Hypophosphoric  acid  : 

)"> 

P-O-H 
\0-H 

Only  those  H  atoms  which  are  connected  with  the  P  atoms 
through  O  atoms  are  basic.  Hence  H3PO2  is  monobasic;  H3PO3  is 
dibasic;  H3PO4  is  tri basic;  H4P2O7  is  tetrabasic;  HPO2  is  monobr.sio, 
and  H4P2O6  is  tetrabasic.  Pyrophosphorous  acid,  0=P^(0H)4  is 
only  known  in  an  organic  derivative,  acetyl -pyrophosphorous  acid  : 
O=P^H.0(C2H30).(0H)2;  and  metaphosphorous  acid,  0=P= 
O.OH  is  unknown. 

Hypophosphorous  Acid. — H3PO2 — 66 — is  a  crystalline  solid,  or, 
more  usually,  a  strongly  acid,  colorless  syrup.  It  is  oxidized  by  air 
to  a  mixture  of  H3PO3  and  H3PO4. 


PHOSPHORUS 


167 


The  hypophosphites,  as  well  as  the  free  acid,  are  powerful  reduc- 
ing agents. 

Phosphorous  Acid^HjPOa — 8- — is  formed  by  deeomposition  of 
phosphorus  trichlorid  by  water:  PCI:i+3H:iO— HsPOa+'iHCl.  It  is  a 
highly  acid  syrup,  is  deeo!iiposed  by  heat^  and  is  a  stroui^  redaciiig 
ageut. 

Phosphoric  Acid-^ Orthophosphoric  (wid — Comnwn  or  trib^fsk  phos- 
phoric  atiil — ^Acidom  phosphoricum  (U.S,;  Br.) — ^II^iPOi — 98 — does 
not  occur  fi^e  in  nature,  but  is  widely  disseniinated  iu  combination, 
in  the  pbosphates,  in  the  three  kingdoms  of  nature. 

It  is  prepared:  (1)  By  converting  bone  pliospbate,  Ca3(P04)2  iuto 
the  eorres]>onding  lead  or  barium  salt,  Pba(P04)-or  Ba:f(P04)2,  and 
decomposing  the  former  by  US,  or  the  latter  by  HjSOi.  (2)  By 
oxidizing  P  by  dilute  HKO3,  aided  by  heat.  The  operation  should  be 
<*ondueted  with  caution,  and  heat  gradually  applied  by  the  sand  bath. 
It  is  best  to  use  red  phosphorus.  This  is  the  process  directed  by  tlie 
U.  S.  and  Br.  Pharm. 

The  concentrated  ufid  is  a  colorless,  transparent,  syrupy  liquid; 
still  containing  H-^O,  whielj  it  gives  off  on  exposure  over  H^SOi^  leaving 
ihe  pure  acid,  in  transparent,  deliquescent,  prismatic  crystals.  It  is 
decomposed  by  heat  to  form,  fii-st,  pyrophosphoric  acid,  then  meta- 
phosphoric  acid.     It  i.s  tribasie. 

If  made  from  arsenical  phosphorus,  and  eomraerciid  phosphorus 
is  arsenical  unless  nuide  liy  the  electrolytic  method  {p.  160),  it  iii^  con- 
taminated with  arsenic  acid,  whose  presence  may  be  recognized  by 
Marsh's  test  (q.  v.).  The  anid  should  not  respond  to  the  indigo  and 
ferrous  sulfate  tests  for  HNO3, 

Ortho-acids  are  those  in  which  the  number  of  hydroxyls  equals 

the  valence  of  the   acidulous  elements.      Thus  orthophosphoric  acid 

is  P(OH)s;    orthocarbonii!    acid,   (MUH)*.       Sometimes,    as    in    the 

«a«e   of  phosphorus,  when  tijis  acid  is  not  known,   that  in  which 

the  number  of   hydroxyls   most    nearly   equals    the  valence  of   the 

ftddiilous  clen^ent  is,  improperly,  railed  the  ortho-a(*id. 

Phosphates. — Pliosplnrric  at:id  lK*ing  tribasic,  the  phosphates  have 
t b e  e 0  m  p o s i  t  i  o n  M'H.POi ;  M'2llP04 ;  M':iP04 ;  M'' ( II2PO4 ) t; ; 
^\\Yi?Oi)r.  M^(P04)2;  M'M'POi;  and  M'^'POi-  The  mono- 
WH«lli<!  salts  are  all  soluble  and  are  strongly  acid.  Of  the  dime  tabic 
**lt8,  those  of  the  alkali  metals  only  ai-e  soluble  and  their  solutions 
*•*  hintly  alkaline;  the  others  am  unstable,  and  exhibit  a  marked 
tendr'Dcv  to  transformation  into  monometallic  or  trimetallic  salts. 
^l»**  normal  phosphates  of  the  alkali  metals  are  the  only  soluble  tri- 
wjetallio  phosphates.  Their  solutions  are  strongly  alkaline,  and  they 
^fP  deeom posed  even  by  weak  acids; 


168 


MANUAL    OF    CHEMISTRY 


N»3pOt 

+ 

COjHj 

HNa^PO^ 

+ 

HNaCOa 

THsodle 

CftrboniQ 

DiMdie 

MoDotodle 

add. 

phoBvhmte. 

eArboDmt«. 

All  the  monometallic  phosphates,  except  those  of  the  alkali  raetals, 
are  decomposed  by  ammonium  hj^droxid,  with  precipitation  of  the 
corresponding  tri metallic  salt. 

Analytical  Characters. — (1)  With  ammoniaeal  solutioa  of  silver 
nitrate,  a  yellow  precipitate,  (2)  With  solution  of  ammoninm 
molybdate  in  HNO3,  a  yellow  precipitate.  (3)  With  magnesia  mix- 
ture.* a  white,  crystalline  precipitate,  soluble  in  acids,  insoluble  in 
amnioninra  hydroxid, 

Pyrophosphoric  Acid — H4P207 — 178. — ^When  phosphoric  acid  (or 
hydro -disodic  phosphate)  is  maintained  at  213*^  {415.4*^  P,),  two  of 
its  raoleenles  unite,  with  the  loss  of  the  elements  of  a  molecule  of 
water:   2H3P04^=H4p207+H20,  to  form  pyrophosphoric  acid. 

Mctaphosphoric  Acid — Glarial  phosphoric  acid — HPOs^^SO — is 
formed  by  heating  H:iP04  or  H4P2O1  to  near  redness:  HgPOi^HPO.i 
+H2O;  or  H4P2O7— 2HPO3+H2O.  It  is  usually  obtained  from  bone 
phosphate;  this  is  first  converted  into  ammonium  phosphate ^  which 
is  then  subjected  to  a  red  heat. 

It  is  a  white,  glassy,  transparent  solid,  odorless  and  acid  in  taste 
and  reaction.  Slowly  deliquescent  in  air,  it  is  very  soluble  in  H2O, 
although  the  solution  takes  place  slowly,  and  is  accompanied  by  a 
peculiar  crackling  sound.  In  constitution  and  basicity  it  resembles 
HNO3. 

The  metaphosphates  are  capable  of  existing  in  five  poljTueric  modi- 
fications (see  polymerisrn):  ^louo-  di~  tri*  tetra-  and  hexmeta-  phos- 
phates: M'POa;  M'2(P03)-  and  M'iPOa)^;  M'aiPOa)^;  M^CPOa)^ 
and  M^(P0:,)4;  and  M'«{PO:,)fi. 

Hypophosphoric  Acid~n4P2O0: — 162. — ^Wheu  phosphorus  is  ex- 
posed to  moist  air  a  strongly  acid  liquid  is  slowly  formed,  known  as 
phosphatic  acid.  This  is  a  mixture  of  phosphorous,  phosphoric  and 
hypophosphoric  acids.  The  last  named  is  separated  from  the  others 
by  taking  advantage  of  the  sparing  solubility  of  its  acid  sodium  salt; 
this  is  then  converted  into  the  lead  salt,  which  is  decomposed  by  H28, 
and  the  liberated  acid  concentrated.  It  has  not  been  cry s tall izt^tl. 
It  is  quite  stable  at  the  ordinary  temperature,  but  slowly  decomposes 
to  a  mixture  of  phosphorous  and  pyrophosphoric  acids.  It  is  qnadri- 
basic.  It  may  l>e  considered  as  formed  by  the  union  of  a  mole- 
cule of  phosphoric  acid  and  one  of  phosphorous  acid,  with  loss  of 
H2O1  HrtPO4+H,PO3=H4P3Ofi+H20. 

Action  of  the  Phosphates  on  the  Economy, — ^The  salts  of  phos- 

•  M;a<3<*  by  disaolvjinf  11  |>l.s.  cryf^ttiHizeiil  umKnesiuin  chlorld  atii]  28  pts.  aramoniiuii  chlorfd  in 
130  pt*.  wtter,  iMldinc  70  pts,  dilute  nmtinntiintn  hydroxlil  {f%K  gr.  0  96)  und  iltpHiig  After  two  daj-s. 


ARSENIC 


169 


phoric  acid  are  important  constitiients  of  aoimal  tiesnee,  and  give 
rine^  when  taken  internally,  in  reasonable  doseSt  to  no  nntoward 
symptoms.  The  acid  itself  may  act  deleteriously,  by  virtue  of  its  acid 
reaction.  Meta-  and  pyrophosphoric  acids,  even  when  taken  in  the 
form  of  neutral  salts,  have  a  distinct  action  (the  p^TO  being:  the  more 
active)  upon  the  motor  ganglia  of  the  heart,  producing  diminution  of 
the  blood* pressure,  and,  in  comparatively  small  doses,  death  from 
cessation  of  the  heart's  action. 


ARSENIC. 

8ymbol=AE— Atomic  weighf=75  (0=16:75j  U=lt74 A)— Mohc- 
ular  weight^^)0  (As*) — 8p,  gr\  of  solid;  crysfaUitie^5,75,  amorphous 
=4.71;   ofvapor=l0.6A  at  860''  (1580''  F, }-- Name  from  dp^^iK6v= 

Occurrence, — Free  in  small  quantity;  in  combination  as  arsenids 

of  Pe,  Co,  and  Ni,  but  most  abundantly  in  the  sulfids,  orpiment  and 
realgar,  and  in  arsenical  iron  pyrites,  or  niispickel. 

Preparation. — (l)By  heating  mispiokel  in  clay  cylinders,  which 
communicate  with  sheet  iron  condensing  tubes, 

(2)  By  heating  a  mixture  of  arsenic  trioxid  and  charcoal;  and 
purifying  the  product  by  resnblimation. 

Properties.^ — Pkyskid. — ^A   brittle,    crystalline,    steel-gray   solid, 

having  a  metallic  lui^tf^r,  or  a  dull,  black,  amorphous  powder.     At  the 

ordinary  pressure,  and  without  contact  of  air,  it  volatilizes  without 

fusion  at  \^if  (356°  F.) ;   under  strong  pressure  it  fuses  at  a  dull  red 

heat.     Its  vrpor  is  yellowish,  and  has  the  odor  of  garlic.     It  is  insol- 

tible  in  H^O,  and  in  other  liquids  unless  chemically  alfei-cd. 

C^fmicfi /.-^Heated  iu  air  it  is  cou verted  into  the  trioxid,  and 
ignites  somewhat  below  a  red  heat.  In  0  it  burns  with  a  brilliant, 
hlimh' white  light.  In  dry  air  it  is  not  altered,  but  in  the  preseuf^e 
•"♦f  moisture  its  surface  becomes  tarnished  by  oxidation.  In  H2O  it  is 
«lowly  oxidized,  a  portion  of  the  oxid  dissolving  in  the  water.  It 
<*ombities  readily  with  Ci,  Br,  I,  and  S,  and  with  most  of  the  metals, 
^^^i^h  H  it  only  combines  when  that  element  is  iu  the  naseent  state, 
"ttrm,  concentrated  H2SO4  is  decomposed  by  As,  with  formation  of 
^'■^i  AsjOa,  and  HjO.  Nitric  acid  is  readily  decomposed,  giving  up 
^^^^U>Xhe  iiiTm^tion  of  arsenic  acid.  With  hot  HCl,  arsenic  tri- 
chlorid  is  formed.  When  fused  with  potassium  hydroxid,  arsenic  is 
^^idized,  H  is  given  off,  and  a  mixture  of  potassium  arsenite  and 
^i^nid  remains,  which  by  greater  heat  is  converted  into  arsenic, 
^hich  volatilizes,  and  potassium  arsenate,  which  remains. 

Elementary  arsenic  enters  into  the  composition  of  fly  poison  and  of 


170    ;  MANUAL    OF    CHEMISTRY 

shot,  and  is  used  in  the  manufacture  of  certain  pigments  and  fire- 
works. 

Compounds  of  Arsenic  and  Hydrogen. — Two  are  known  :  the 
solid  AS2H  (f )  and  the  gaseous,  AsHs. 

Hydrogen  Arsenid — Arsin — Arseniuretted  or  arsenetted  hydrogen 
— Arsenia — Arsenamin — AsHa — Molecular  weight=7S — 8p.  gr,=2.695 
A'-'Liquefies  at  —40''  (—40''  F. ) . 

Formation. — (1)  By  the  action  of  H2O  upon  an  alloy,  obtained 
by  fusing  together  native  sulfid  of  antimony,  2  pts. ;  cream  of  tartar, 
2  pts.;  and  areenic  trioxid,  1  pt. 

(20  By  the  action  of  dilute  HCl  or  H2SO4  upon  the  arsenids  of 
Zn  and  Sn.  This  is  practically  the  same  as  3,  nascent  hydrogen 
being  formed  bv  the  action  of  the  metal  upon  the  acid. 

(3)  Whenever  a  reducible  compound  of  arsenic  is  in  presence  of 
nascent  hydrogen.     (See  Marsh  test.) 

(4)  By  the  action  of  H2O  upon  the  arsenids  of  the  alkali  metals. 

(5)  By  the  combined  action  of  air,  moisture  and  organic  matter 
upon  arsenical  pigments. 

(6)  By  the  action  of  hot  solution  of  potassium  hydroxid  upon 
reducible  compounds  of  As  in  the  presence  of  zinc. 

Properties. — Physical. — A  colorless  gas  ;  having  a  strong  allia- 
ceous odor;  soluble  in  5  vols,  of  H2O,  free  from  air. 

Chemical. T-lt  is  neutral  in  reaction.  In  contact  with  air  and 
moisture  its  H  is  slowly  removed  by  oxidation,  and  elementarj'  As 
deposited.  It  is  also  decomposed  into  its  elements  by  the  passage 
through  it  of  luminous  electric  discharges;  and  when  subjected  to  a 
red  heat.  It  is  acted  on  by  dry  O  at  ordinary  temperatures  with  the 
formation  of  a  black  deposit,  which  is  at  first  solid  hydrogen  arsenid, 
later  elementary  As.  A  mixture  of  AsHa  and  O,  containing  3  vols. 
O  and  2  vols.  AsHs,  explodes  when  heated,  forming  AS2O3  and  H2O. 
If  the  proportion  of  O  be  less,  elementary  As  is  deposited. 

The  gas  burns  with  a  greenish  fiame,  from  which  a  white  cloud  of 
ai*senic  trioxid  arises.  A  cold  surface,  held  above  the  flame,  becomes 
coated  with  a  white,  crystalline  deposit  of  the  oxid.  If  the  fiame  be 
cooled,  by  the  introduction  of  a  cold  surface  into  it,  the  H  alone  is 
oxidized,  and  elementary  As  is  deposited.  Chlorin  decomposes  the 
gas  explosively,  with  formation  of  HCl  and  arsenic,  or  arsenic  tri- 
chlorid,  if  the  CI  be  in  excess.  In  the  presence  of  H2O,  arsenous  and 
arsenic  acids  are  formed.  Bromin  and  iodin  behave  similarly,  but 
with  less  violence. 

All  oxidizing  agents  decompose  it  readily;  H2O  and  arsenic  tri- 
oxid being  formed  by  the  less  active  oxidants,  and  H2O  and  arsenic 
acid  by  the  more  active.     Solid  potassium  hydroxid  decomposes  the 


AESENIC 


171 


^^B  partially,  and  becomes  coated  with  a  dark  deposit,  which  seems 
to  be  elementary  arseuic.  Solutions  of  the  alkaline  hydroxids  absorb 
nnd  decompose  it;  H  is  given  off  and  an  alkaline  arsenite  remains 
in  the  solution.  Many  metals,  when  heated  in  HaAs,  decompose  it 
with  formation  of  a  metallic  arsenid  and  liberation  of  hydroijen. 
Solution  of  silver  nitrate  is  reduced  by  it ;  elementary  silver  is  de* 
posited*  and  the  solution  contains  silver  arsenite. 

Although  Hi:S  and  llaAs  decompose  each  other  to  a  great  extent, 
with  formation  of  arsenic  trisulfidt  in  the  pi'csence  of  air,  the  two 
gwaes  do  not  act  upon  each  other  at  the  ordinary  temperature,  even 
in  the  direct  sunlight,  either  dry  or  in  the  presence  of  n^O,  when  air 
is  absent.  Hence  in  making  HjS  for  use  in  toxicological  analysis^ 
materials  free  from  As  must  be  used  ;  or  the  H28  must  be  purified  as 
described  on  p.  139, 

Compounds  of  Arsenic  with  the  Halogens.^ — Arsenic  Trifluorid 

— ^AaPi— 132,— A  colorless,  fnmiog  liquid,  boiling  at  63""  (US'^F.), 
^ibtained  by  distilling  a  mixture  of  AssOs,  H2SO4,  and  fluorspar.  It 
attacks  glass. 

ArsenicTrichlorid— AsCls — 181.5. — Obtained  by  distilUng  a  mix- 
ture of  As-iOj,  II-SO^*  and  XaCl,  using  a  well -cooled  receiver. 

It  is  a  colorless  liquid,  boils  at  134°  (273°  F.),  fumes  when  ex- 
posed to  the  air,  and  volatilizes   readily  at   temperatures  below  its 
ImiUng  point.     Its  formation  innst  be  avoided  in  processes  for  the 
chemico- legal  detection  of  arsenici  lest  it  be  volatilized  and  lost.     It 
formed  by  the  action  of  HCl,  even  when  comparatively  dilute,  upon 
AsaO^at  the  temperature  of  the  water- bath;   but»  if  potassium  chlo- 
rate be  added,  the  trioxid  is  oxidixed  to  arsenic  acid,  and  the  forraa- 
liott  of  the  chlorid  thus  prevented.     Arsenic  trioxid,  when  fused  with 
«odiafu    nitrate,    is   converted    into   sodium    arsenate,   which    is    not 
volatile.     If,  however,  small  rjuantities  of  chlorids  be  present,  AsCb 
w  formed.     It  is  !n>'hly  poisonous. 

Arsenic  Tribromid — AsBr;i — 315.— Obtained  by  adding  powdered 
A*  to  Br,  aiid  distilling  the  product  at  220°  (428''F.).  A  solid, 
colorless,  crystalUne  body,  fuses  at  20°-25°  (68''-77°  F/),  boils  at 
220*  (428*^  F.) ,  and  is  decomposed  by  H^jO. 

Arsenic Triiodid — Arsenii  iodidum,  U.  S. — ABI3 — 456, — Formed 
'yiicltiing  As  \*)  a  solution  of  I  in  carbon  bisulfid,  or  by  fusing  to- 
Wher  As  and  I  in  proper  proportions.  A  brick -i-ed  solid »  fusthld 
*od  volatile.  Soluble  in  a  large  quantity  of  H^O.  Deuoni posed  1>y 
*8rnall  ^|uauti^y  of  H-0  into  III,  AS-O3,  IIsO  and  a  residue  of  x\sl:i. 

[Compounds  of  Arsenic  and  Oxygen.  —  Two  are  known:   AsjOs 
*»<»  X^h^ 
Probably  the  gray  substance  formed  by  the  action  of  moist  air  on 
•"Hientarj'  arsenic  is  a  lower  oxid. 


172 


MANUAL    OF    CHEMISTRY 


Arsenic  Trioxid  —  Argenous  anhydrid  —  Arsenous  oxid  —  White 
arsenic — Arsenic — Amenotis  acid — Acidum  arseniosum,  U*  S.;  Br. 
— AS2O3— 198. 

Preparation. — (1)  By  roastmg  the  native  sulfids  of  arsenic  in  a 
current  of  air. 

(2)  By  burning  arsenie  in  air  or  oxygen. 

Properties* — FkysicuL — It  occurs  in  three  forms t  crystallized  or 
'* powdered,'*  vilreous,  and  porcdainous ,  When  freshly  fosed,  it  ap- 
pears in  colorless  or  faintly  yellow,  translucent,  vitreous  masses, 
having  no  visible  crystalline  structure.  Shortly,  however,  these 
masses  become  opaque  upon  the  surface,  and  preseut  the  appearance 
of  porcelain.  This  change  slowly  progresses  toward  the  center  of  the 
iiiasSt  which,  however,  remains  vitreous  for  a  long  time.  When 
arsenic  trioxid,  is  sublimed,  if  the  vapoi*s  be  condensed  upon  a  cool 
surface,  it  is  deposited  in  the  form  of  brilliant  octahedral  crystals, 
which  are  larger  and  more  perfect  the  nearer  the  teraperature  of  the 
condensing  surface  is  to  180°  (356°  FJ.  When  sublimed  under 
slightly  increased  pressure,  or  in  an  atmosphere  of  Sds  right  rhom- 
bic prisms  occur  among  the  octahedra.  It  is  therefore  tlimc^rphous. 
The  crystalline  variety  may  be  converted  into  the  vitreous,  by  keeping 
it  for  some  time  at  a  teraperature  near  its  point  of  volatilization. 

Although  AsoOa  is  heavier  than  water,  when  thmwn  upon  tliat 
liquid  a  large  part  of  the  crystalline  powder  floats,  and  a  part  t*f  that 
which  sinks  at  first  subsequently  rises.  This  is  due  to  adhesion  of 
air  to  the  particles  of  the  solid.  The  same  phenomenon  renders  the 
solution  of  AS2O3  in  water  slow  and  irregular.  The  vitreous  variety 
is  more  readily  soluVjle  than  the  crystalline.  The  taste  of  arsenic 
trioxid  in  solution  is  very  faintj  at  first  sweetish,  afterward  very 
slightly  metallic.  The  solid  is  almost  tasteless.  It  is  odorless.  In 
aqueous  solution  it  has  a  faintly  acid  reaction.  The  sp.  gr,  of  the 
vitreous  variety  is  3.785;  that  of  the  crystalline,  3.G8!*. 

Vhfmicnl.^lts  solutions  are  acid  in  reaction,  and  probably  contain 
the  true  arsenous  acid,  HsAsOri.  They  are  neutralized  by  bases,  wilh 
formation  of  arscnites.  Solutions  of  sodium »  or  potassium  hydroxid, 
ur  carbonate  dissolve  it,  with  formation  of  the  eori'csponding  arsenite. 
It  is  readily  reduced,  with  separation  of  As,  Avhen  heated  with  hydro- 
gen, carbon,  and  potassium  cyanid,  and  at  lower  teraperatnres  by 
more  active  reducing  agents.  Oxidizing  agents,  such  as  HXO3,  the 
chlorin  oxyacids,  chromic  acid,  convert  it  into  arsenic  pentoxid  or 
arsenic  acid,  Its  solution,  acidulated  with  HCl  and  boiled  in  presence 
of  copper,  deposits  on  the  metal  a  gray  film,  composed  of  an  alloy  of 
Cn  and  As. 

Arsenic  Pentoxid^.-lr5fii«V  anhydrid — Arsenic  oxid — AS2O5— 230 
—is  obtained  by  heating  arsenic  acid  to  redness.  _  It  is  a  white,  amor- 


ARSENIC 


liri 


phons  aolid»  wLicli,  when  exposed  to  the  air,  slowly  absorbs  moisture. 
It  is  fusible  at  a  dull  red  heat,  and  at  a  slightly  higher  temperature 
decomposes  to  AS2O3  and  Oj.  It  dissolves  slowly  in  HjO,  forraiug^ 
arseaic  acid,  HaAs04. 

Arsenic  Acids, — The  oxyaeids  of  ar^senic  form  a  series,  eorre- 
spondiug  to  that  of  the  oxyafids  of  phosphorus,  exijept  that  the  hypo- 
ardeQOQs  and  hypoarsenic  acids  are  unknown,  and  pjTo-  and  inetar- 
senous  acids  are  known  in  their  salts: 


Araenous  acid: 


/O— H 
O^Aa— 0— H 

Pyroarse  nou  s  ae  id :  O  q  _  jt 

.0— H 


Arsenic  acid: 


/O-H 

0=Ab— O— H 

\0— H 

0=A»-<^-H 
\n 


\A8 


Metareenona  acid :  0=A8— D^H 


Pyroaraenio  acid:  y^ 

0=As— O— H 

\0— H 

/O— H 
Metarsenir!  acid:  O^^Ag=0 


Arsenous  Acid,— HaAsO^t — 126 — exists  in  aqueous  solutions  of 
the  trioxid,  although  it  has  not  beeu  separated.  ConespoudiriK  to 
it  are  important  salts,  called  arsenites,  whieh  iiave  the  ;jeneral  for- 
mnlfla  H>r2AsO.'{,  HM^'AsOat,  HiM^'lAsOal^.  Pyro-  aud  luetarsenous 
acids  are  only  knowu  in  combination. 

Arsenic  Acid — Orfhoftrs^'ufc  acid — H:iA.s(>4^l42 — is  obtained  by 
oxidizing:  AS2O3  with  HNOa  in  the  preseuee  of  H2O:  a\820:<H-2H20  + 
2HN03=2HriAs04+N203,  A  similar  oxidation  is  also  effected  by  CI, 
aqua  re^a»  and  other  oxidants. 

A  sympyt  colorless,  strongly  acid  solution  is  thus  obtained,  which, 
at  15^  (59**  F.)»  becomes  semi-solid,  from  the  fonnation  of  transpar- 
ent crystals,  containing  1  Aq.    These  crystals,  wliieh  are  very  soluble 
and  deliquescent,    lose    tiieir   Aq   at    100'^    (212"^  F,),  and    furm   a 
white,  pasty  mass,   composed  of   minute  white,  anhydrous  needles. 
At  higher  temperatures  it  is  converted  into  II4AS2O7,  IlAsOj,  aud 
A»jOj.     In  presence  of  nascent  II  it  is  decuui posed  into  U-O  aud 
A«H3.     It  is  reducible  to  II:iAsO:i  l>y  8O2. 

The  action  of  Hi^S  upmi  acid  solutions  of  arsenic  acid,  or  of  the 
arsenates,  varies  with  the  rapidity  of  the  action  and  the  temperatni-i^ 
•t  ^hich  it  occurs.  With  a  slow  enrrent  of  iljS,  at  a  low  tcinpera- 
t'lPf*,  no  precipitate  is  formed,  aud  the  solution  remains  colorless, 
l-uder  these  conditions  thioxyarsenic  acid>  HaAsOsS,  is  formed: 
Uu\>i04+H2S=H:iAsSOa+H20.  By  a  further  action  of  H2S,  arsenic 
P^nrjiflulfid  is  formed:  2H-}As03S+3H2H=As2S5+6Il20.  If  the  cur- 
'^"t  of  H2S  l>e  very  slow,  the  thioxyarsenic  acid  produced  is  decom- 
po«ecl  ac^rdiufiT  to  the  equation:   2HjAsO:iS=As20a+3H20+Sa  and 


174  MANUAL    OF    CHEMISIRY 

the  precipitate  then  produced  consists  of  a  mixture  of  AS2S3,  AsjSs 
andS. 

Like  phosphoric  acid,  arsenic  acid  is  tribasic;  and  the  arsenates. 
resemble  the  phosphates  in  composition,  and  in  many  of  their  chemi- 
cal and  physical  properties. 

Pyroarsenic  Acid — EUAS2O7 — 266. — Arsenic  acid,  when  heated  ta 
160°  (320°F.),  is  converted  into  compact  masses  of  pyroarsenic  acid: 
2H3As04=H4As207+H20.  It  is  very  prone  to  revert  to  arsenic  acid, 
by  taking  up  water. 

Metarsenic  Acid— HAsOs— 124.— At  200^-206°  (392^-403^  P.) 
II4AS2O7  gradually  loses  H2O  to  form  metarsenic  acid:  H4AS2O7- 
=2HAs03+H20.  It  forms  white,  pearly  crystals,  which  dissolve 
readily  in  H2O,  with  regeneration  of  H3ASO4.     It  is  monobasic. 

Compounds  of  Arsenic  and  Sulfur.  —  Arsenic  Bisulfid — Red 
snlfid  of  arsenic — Realgar — Red  orpiment — Ruby  sulfur — Sandcrraeh — 
AS2S2 — 214 — occurs  in  nature,  in  translucent,  ruby -red  crystals.  It 
is  also  prepared  by  heating  a  mixture  of  AS2O3  and  S.  As  so  ob- 
tained it  appears  in  brick-red  masses. 

It  is  fusible,  insoluble  in  H2O,  but  soluble  in  solutions  of  the 
alkaline  sulfids,  and  in  boiling  solution  of  potassium  hydroxid. 

Arsenic Trisulf id . —  Orpiment — Auriplf/mentum  —  Yellow  sulfid  of 
arsenic — King^s  yellow — AS2S3 — 246  —  occurs  in  nature  in  brilliant 
golden  yellow  flnkes.  Obtained  by  passing  H2S  through  an  acid 
solution  of  AS2O3;  or  by  heating  a  mixture  of  Ai  and  S,  or  of  AsaOa 
and  S  in  equivalent  proportions. 

When  formed  by  precipitation,  it  is  a  lemon -yellow  powder;  or  ia 
orange-yellow,  erystailine  masses,  when  prepared  by  sublimation. 
Almost  insoluble  in  cold  H2O,  but  sufficiently  soluble  in  hot  H2O  to 
ronnnunicate  to  it  a  distinct  yellow  color.  By  continued  boiling  with 
IliO  it  is  decomposed  into  H2S  and  AS2O3.  Insoluble  in  dilute  HCl; 
but  readily  soluble  in  solutions  of  the  alkaline  hydroxids,  carbonates,, 
and  sulfids.     It  volatilizes  when  heated. 

Nitric  acid  oxidizes  it,  forming  H3ASO4  and  H2SO4.  A  raixtni*e 
of  HCl  and  potassium  chlorate  has  the  same  effect.  It  corresponds, 
in  constitution  to  AS2O3,  and  like  it,  may  be  regarded  as  an  an- 
hydrid,  for  although  thioarsenous  acid,  H3ASS3,  has  not  been  sepa- 
rated, the  thioai'senites,  pyro-  and  meta-thioarsenites  are  well- 
characterized  compounds. 

Arsenic  Pentasulfid — AS2S5 — 310 — is  formed  by  fusing  a  mixtnre 
of  AS2S3  and  S  in  proper  proportions,  and,  by  the  prolonged  action 
of  H2S,  at  low  temperatures,  upon  solutions  of  the  arsenates. 

It  is  a  yellow,  fusible  solid,  capable  of  sublimation  in  absence  of 
air.  There  exist  well-defined  thioarsenates,  pyro-and  meta-thia 
arsenates. 


ARSENIC 


175 


Action  of  Arsenical  Compounds  Upon  the  Animal  Economy. 

The  poisoDous  nature  of  many  of  the  arstmical  compounds  has 
beeu  known  from  remote  antiquity,  and  it  is  probable  that  more 
murders  have  been  eoraraitted  by  their  use  than  by  that  of  all  other 
toxic  substances  combined.  Even  at  the  present  time  —  notwith- 
tttauding  the  fact  that,  suspicion  once  aroused,  the  deteetion  of 
arsenic  in  the  dead  body  is  certain  and  comparatively  easy — ^crim- 
inal arsenical  poisoning  is  still  (|uite  common,  especially  in  rural 
districts. 

The  poison  is  usually  taken  by  the  mouth,  but  it  has  also  been 
itttroduced  by  other  channels;  the  skin,  either  uninjured  or  abraded, 
the  rectum,  vagina,  and  male  u  ret  lira.  The  forms  in  which  it  has 
hem  taken  are:  (1)  Elementary  arsenic,  which  is  not  poisonous  so 
long  as  it  remains  such.  In  contact  with  water,  or  with  the  saliva^ 
liowever,  it  is  converted  into  an  ox  id,  which  is  then  dissolved,  and, 
\*^m^  capable  of  absorption,  produces  tlae  ^characteristic  effects  of  the 
■irsenical  compounds.  Certain  fly-papers  and  fly-poisons  contain  As, 
fl  portion  of  which  has  been  oxidized  by  the  action  of  air  and 
fnoJKtnre.  (2)  Hydrogen  arsenid,  tlie  most  actively  poisonous  of 
the  inorofanic  compounds  of  arsenic,  has  been  the  cause  of  several 
**<*«' i dental  deaths,  among  others,  that  of  the  chemist  Ochlen,  who 
•^i^l  in  consequence  of  having  inhaled  the  gas  while  experimenting 
^it.h  it,  In  other  cases  death  has  followed  the  inhalation  of  hy- 
drogen, made  from  zinc  and  sulfuric  acid  eoutaminated  with  arsenic. 
13)  Arsenic  trioxid  is  the  compound  most  frequently  used  by  crim* 
tnala.  .  It  has  been  given  by  every  channel  of  entrance  to  the  circu* 
«tion;  in  some  instances  concealed  with  great  art,  in  others  merely 
^*^W  in  suspension  by  stirring  in  a  transparent  iluid,  given  to  an 
^titoxicatM  person.  If  the  poison  have  been  in  quantity,  and  nndis- 
***Ived^  it  may  be  found  in  the  stumach  after  death,  in  the  form  of 
*'^ht-fiided  crystals,  more  or  less  worn  by  the  action  of  the  solvents 
^•th  which  it  has  come  in  contact.  (4)  Potassium  arsenite^  the 
'**'tive  substance  in  ^*Fowler^s  solution,^*  although  largely  used  by  the 
'•^il.v  ill  malarial  districts  as  an  ague*cure,  has,  so  far  as  the  records 
*o<*w,  produced  but  few  eases  of  fatal  poisoning.  (5)  Sodium 
•r«enite  is  sometimes  used  to  clean  metal  vessels,  a  practice  whose 
natiirHl  results  are  exemplified  in  the  death  of  an  individual  who 
'^t^tik  beer  from  a  pewter  mug  so  cleaned;  and  in  the  serious  illness 
^^  340  (rhildren  in  an  English  iustitution,  in  which  this  material  had 
*^n  URed  for  cleaning  the  water -boiler.  (6)  Arsenic  acid  and 
^senates. — -The  acid  itself  h^s.  so  far  as  we  know,  been  directly  fatal 
*<^tiooTie.  The  cases  of  death  nnd  illness,  however,  which  hnvc  been 
Pi*t  to  the  account  of  the  red  anil  in  dyes,  are  not  due  to  them  directly » 


176 


MANUAL    OP    CHEMI8TEY 


I 


but  to  orseaical  residues  remaining  in  them  as  the  result  of  defective 
processes  of  manufacture,  (7)  Sulfids  of  arsenic— Poisoning  by 
these  is  generally  due  to  the  use  of  orpiment,  introduced  into  articles 
of  food  as  a  coloring  matter,  by  a  combination  of  fraud  and  stu- 
pidity»  in  mistake  for  turmeric,  (S)  The  arsenical  greens*-^Scheele's 
green,  or  cupric  arsenite,  and  Hchweinforth  grcim,  or  euprie  aeeto- 
raetarsenite  (the  latter  commonly  known  in  the  United  States  as 
Paris  green*  a  name  applied  in  Europe  to  one  of  the  anilin  pig- 
ments). These  substances,  although  rarely  administered  with  mur- 
derous intent,  have  been  the  cause  of  death  in  a  great  number  of 
cases.  m 

The  arsenical  pigments  may  also  produce  disastrous  results  by^ 
'* accident;*'  by  being  incorporated  in  ornamental  pieces  of  confection- 
ery; by  being  used  in  the  coloring  of  textile  fabincs,  fi*om  which  they 
may  be  easily  rubbed  off;  froni  their  use  for  the  destruction  of  insects, 
and  by  being  used  in  the  manufacture  of  wall -paper.  Many  instances 
of  chronic  or  subacute  arsenical  poisoning  Imve  resulted  from  inhab- 
iting rooms  hung  with  paper  whose  whites,  reds,  or  greens  were  pro- 
duced by  arsenical  pigments.  From  sueh  paper  the  poison  is  dissemi- 
nated in  the  atmospliere  of  the  room  in  two  waysr  either  as  an 
impalpable  powder,  meebanieally  detached  from  the  paper  and  flt»atiug 
in  the  air,  or  by  their  decomposition,  and  the  consequent  diffusion  of 
volatile  arsenical  compounds  in  the  air. 

The  treatment  in  acute  arsenical  poisoning  is  thesame^  whatever 
may  be  the  form  in  which  the  poison  has  been  taken,  if  it  have  been 
taken  by  the  mouth.  The  first  indication  is  the  removal  of  any  unab- 
sorbed  poison  from  the  alimentary  canal,  If  vomiting  liavi?  not 
occurred  froju  the  effects  of  the  toxic,  it  should  be  induced  by  the 
administration  of  zine  sulfate,  or  by  mechanical  means.  When  thofl 
stomach  has  been  emptied^  the  chemical  antidote  is  to  be  administered, 
with  a  view  to  the  transformation,  iu  the  stomach,  of  any  remaining 
arsenical  compound  into  the  insoluble,  and  therefore  innocuous,  fer- 
rous arsenate.  To  prepare  the  antidote,  a  solution  of  ferric  sulfate^ 
Ltq.  ffrri  tersuipJifttia  (V ,  H.)^^Liq,  ferri  perstdphafis  (Br)  is  to  be 
diluted  with  three  volumes  of  water,  antl  treated  with  aqua  ammonim 
in  slight  excess.  The  precipitate  formed  is  then  collected  upon  a 
muslin  filter,  and  washed  with  water  untU  the  washings  are  nearly 
tasteles^s.  The  contents  of  the  filter — Ffrri  oxidum  htjdratmn  (U.  S,)^ 
Fif'ri  peroxidum  humidtdn  (Br.)  are  to  be  given  moist,  in  repeated 
doses  of  one  to  two  teaspoonsful,  until  an  amount  of  the  hydrate 
equal  to  20  times  the  weight  of  white  arsenic  taken  has  been  ad- 
ministered. Dialyzed  iron  may  be  given  while  the  hydrate  is  iu 
preparation,  or  whenever  the  materials  for  its  preparation  are  not 
obtainable. 


I 


AESENIC 


177 


Precautions  to  be  taken  by  the  Physician  in  cases  of  Suspected 

Poisoning* 

It  will  rarely  happen  that  in  a  case  of  suspected  homicidal  poison- 
iDg  hy  arsenic,  or  by  other  poisous,  tlie  physician  in  charge  will  be 
willing  or  competent  to  conduct  the  chemical  analysis,  upon  whicb, 
prol>ably,  the  conviction  or  acquittal  of  the  accused  will  mainly  depend. 
li^on  his  knowledge  and  care,  however,  the  success  or  futility  of  ilvi 
ohemist's  labors  depends  in  a  great  measure. 

It  is,  as  a  rule,  the  physician  who  first  suspects  foul  play;  and 
while  it  is  undoubtedly  his  duty  to  avoid  any  public  manifestation  of 
hiissaspicion,  it  is  as  certainly  his  duty  toward  his  patient  and  toward 
the  community,  to  satisfy  himself  as  to  the  truth  or  falsity  of  his 
finspieion  by  the  application  of  a  simple  test  to  the  excreta  of  the 
patient  during  life,  the  result  of  which  may  enable  him  to  prevent  a 
('rime,  or,  failing  that,  take  the  first  step  toward  the  punishment  of 
tlie  criminal. 

la  a  case  in  which,  from  the  s>^mptoms,  the  physician  suspects 
poisoning  by  any  substance,  he  should  himself  test  the  urine  or 
f»C€8,  or  both,  and  govern  his  treatment  and  his  actions  toward  the 
patient,  and  those  surrounding  the  patient,  by  the  results  of  his 
examination.  Should  the  case  t^*rminate  fatally,  he  should  at  onco 
<*oimnunicate  his  suspicions  to  the  prosecuting  officer,  and  require  a 
post-mortem  investigation,  w^iich  shonkl,  if  at  all  possible,  be  con- 
ducted in  the  presence  of  the  chemist  who  is  to  conduct  the  analysis. 
Fw,  be  the  physician  as  skilled  as  he  may,  there  are  odors  and 
•Ppearanees,  observalde  in  many  eases  at  the  opening  of  the  body, 
ft»ll  of  meaning  to  the  toxicological  chemist,  which  arc  ephemeral, 
*Dd  whose  bearing  uix>n  the  case  is  not  readily  recognized  by  those 
»ot  thoroughly  ext>ericneed. 

Cases  frequently  arise  in  which  it  is  impossible  to  bring  the  ehem- 
wtupon  the  ground  in  time  for  the  autopsy.  In  sneh  cases  the  phy- 
sician should  remember  that  that  portion  of  the  poison  remaining  in 
Ui^  alimentary  tract  (we  are  speaking  of  true  poisons)  is  but  the 
JWidue  of  the  dose  in  excess  of  that  which  has  been  necessary  to'pro- 
ottca  death;  and,  if  the  processes  of  eliinination  have  been  active, 
*w^Pe  may  remain  no  trace  of  the  poison  in  the  alimentary  canal, 
*hile  it  still  may  be  detectable  in  the  deeper- seated  organs.  The 
V^mn  may  also  have  been  administered  by  another  channel  than  the 
"wnth,  in  which  event  it  may  not  reach  the  stomach. 

For  these  reasons  it  is  not  sufficient  to  send  the  stomach  alone  for 
aoalygig.  The  chemist  should  also  receive  the  entire  intestinal  canal, 
th*?  liver,  the  spleen,  one  or  both  kidneys,  a  piece  of  muscular 
tittae  from   the   leg,  the   brain,   and  any  urine  that  may  remain 

12 


178 


MANUAL    OF    CHEMISTRY 


in  the  bladder.  The  intestinal  eanal  should  be  removed  and 
sent  to  the  chemist  mthont  having  been  opened^  and  with  ligatures, 
enclosing  the  contents,  at  the  two  ends  of  the  stomach  and  at  the 
lower  end  of  the  intestine.  The  brain  and  alimentary  canal  are  to  be 
placed  in  separate  jars,  and  the  otbcr  viscera  in  another  jar  together; 
the  nrine  in  a  vial  by  itself.  All  of  these  vessels  are  to  be  new  and 
clean,  and  are  to  be  closed  by  new  corks,  or  by  glass  stoppers,  or 
covers  {not  zine  screw* caps),  which  are  then  coated  with  paraffin  (not 
sealing-wax),  and  so  fastened  with  strings  and  seals,  that  it  is  impos* 
sible  to  open  the  vessels  without  cutting  the  strings  or  bi'caking  the 
seals.  Any  vomited  matters  are  to  be  preserved.  If  the  physiciaa 
fail  to  observe  these  precautions,  lie  has  probably  made  the  breach  in 
the  evidence  through  which  the  criminal  will  escape,  and  has  at  the 
outset  defeated  the  aim  of  the  analysis. 

Analytical  Characters  of  the  Arsenical  Compounds. — Arsenous 
Compounds*— {!)  H-iS,  a  yellow  color  in  neutral  or  alkaline  liquids; 
a  yellow  ppt.  in  acid  liquids.  The  ppt.  dissolves  in  solutions  of  the 
alkaline  hydroxids,  carbonates  and  sulf hydrates;  but  is  scarcely 
affected  by  IlCl.     Hot  HXO3  decomposes  it. 

(2)  AgNOsi  in  the  presence  of  a  little  XIIiHO,  gives  a  yellow 
ppt.  This  test  is  best  applied  by  placing  the  neutral  arsenical  solu- 
tion in  a  porcelain  capsule,  adding  neutral  solution  of  AgNOa*  and 
blowing  upon  it  over  the 
stopper  of  the  NH-iHO  bottle, 
moistened  with  that  reagent. 

(3)  Cn804  under  the  same 
conditions  as  in  (2)  gives  a 
yellowish  green  ppt. 

(4)  A  small  quantity  of 
solid  AS2O3  is  placed  in  the 
poiijt  a  of  the  tube,  Fig.  35; 
above  it,  at  ^,  a  splinter  of 
recently  ignited  charcoal;  h  is 
first  heated  to  redness,  tlitn 

ff;  the  vapor  of  AS2O3,  passiug  over  the  hot  charcoal,  is  reduced,  and 
elementary  As  is  deposited  at  c  in  a  metallic  ring.  The  tube  is  then 
cut  between  a  and  c,  the  larger  piece  held  with  d  uppermost  and 
heated  at  e  ;  the  deposit  is  volatilized,  the  odor  of  garlic  is  obser\-ed, 
and  bright,  octahedral  crj^stals  (Fig,  37)  appear  in  the  cool  part  of 
the  tube. 

(5)  Reinsch  Test.^ — The  suspected  liquid  is  acidulated  with  one- 
sixth  its  bulk  of  IICl.  Strips  of  electrotype  copper  are  immersed  in 
the  liquid,  which  is  boiled.  In  the  presence  of  an  arsenous  com- 
pound, a  gray  or  bluish  deposit  is  formed  upon  the  Cu*     A  similar 


ARSENIC 


179 


I 


r 


deposit  is  produced  by  other  substances  (S,  Au,  Pt»  Bi»  Sb,  Hg),  To 
complete  the  test  the  Cu  is  removed,  wasbt'tl,  and  dried  between  folds 
of  filter  paper,  without  removing^  the  deposit.  The  copper,  with  its  ad- 
herent film,  is  rolled  into  a  cylinder,  and  introduced  into  a  dry  piece 
of  Bohemian  tubing,  about  one-fourth  inch  in  diameter  and  six  inches 
long,  which  is  held  at  the  angle  shown  in  Fi;^.  36  and  heated  at  the 
point  eoDtaining  the  copper.  If  the  deposit  consist  of  arsenic,  a 
white  deposit  is  formed  at  n,  which  contjiins  brilliant  specks,  aud, 
when  examioed  with  a  niaguifler,  is  fonnd  to  consist  entirely  of 
minute  octahedral  crystals  {Fig.  37). 

If  the  stain  upon  the  copper,  formed  in  the  fii'st  part  of  the  reac- 
tion, have  been  caused  bj"  S,  Au»  Pt,  or  Bi,  no  sublimate  is  produced 
during  the  subsequent  heating  in  the  glass  tube,  as  the  product  of 
oxidatiou  of  sulfur  is  gaseous,  Au  and  Pt  are  neither  oxidized  nor 
volatilized,  and  Bi  is  oxidized,  but  its  oxid  is  not  volatile.  Subli- 
mates are,  however,  formed  from  deposits  caused  by  Sb  or  Hg,  which 


Fi(l.M. 


PIO.  37. 


differ  from  that  produced  by  arsenic  in  the  following  respects:  That 
from  Sb  consists  of  Sb^O^,  which,  although  isodiraorphous  with  As-iOj, 
does  not  crystallize  under  these  conditions,  except,  sometimes,  to 
form  prismatic  crj^stals  at  the  heated  part  of  the  tube,  or  an  occa- 
fflonal  octahedral  crystal  beyond.  The  sublimate  is  entirely,  or 
ihoost  entirely  amorphous,  or  granular,  possibly  containing  one  or 
two  octahedral  crystals,  whose  borders  are  darker  than  those  of 
A»Oj.  The  sublimate  from  Hg  consists  of  mieroscopic  globules  of 
th<!  liquid  metaL  Reinsch*s  reaction  is,  therefore,  a  test  for  anti- 
roony  aud  mercurj^  as  well  as  for  arsenic. 

The  advantages  of  this  test  are:  it  may  be  applied  in  the  presence 
^'f  organic  matter,  to  the  nrine  for  instance  \  it  is  easily  conducted  ; 
^^i  its  positive  results  are  not  misleading,  if  the-  test  be  carrhd  to 
^mpktion.  These  advantages  render  it  the  most  suitable  method  for 
l>hy8ieiau  to  use,  during  the  life  of  the  patrfut.  It  should  not  be 
'I  itfler  death  by  the  physician,  as  by  it  copper  is  introdured  into 
the  mibstanceB  under  examination,  which  may  subsequently  interfere 
oiwJy  with  the  analysis.     The  purity  of  the  Cn  and  IK 'I  must  be 


180 


MANUAL    OF    CHEMISTBY 


proved  by  a  blank  testing  before  use.  Reinscli's  test  is  not  as  deli- 
cate as  Marshes,  and  it  only  reacts  slowly  and  imperfectly  when  tiie 
arsenic  is  in  the  higher  stage  of  oxidation,  or  in  presence  of  oxidizing 
agents, 

(6)  Marsh's  test  is  based  npon  the  formation  of  AsHa  when  a 
reducible  eoiopound  of  arsenic  h  in  presence  of  nascent  H;  and  the 
subsequent  decomposition  of  the  arsenical  gas  by  heat,  with  separa- 
tion of  elementary  ai-senic. 

The  apparatus  used  (Fig.  38)  consists  of  a  glass  generating  vessel, 
a,  of  abont  150  cc.  capacity, provided  with  a  funnel-tube  having  u 
stop -cock,  and  a  lateral  outlet,  either  fitted  in  with  a  cork,  or,  better, 
ground  in.  The  lateral  outlet  is  connected  with  a  tube,  b,  filled  with 
fragments  of   calcium   chlorid ;     which  in  turn    connects   with    the 


FlO.  38. 

Bohemian  glass  tube  cc,  which  should  be  about  0.5  cent,  in  diam" 
eter,  and  abont  80  cent.  long.  The  tube  is  protected  by  a  tnbe  of 
wire  gauze,  within  which  it  is  adjusted  in  the  furnace  as  shown  in 
the  figure.  The  other  end  of  cc  is  bent  downward,  and  dips  into  a 
solution  of  silver  nitrate  in  the  test -tube,  d. 

The  vessel  a  is  first  charged  with  about  25  grams  of  an  alloy 
of  pure  granulated  zinc,  with  a  small  quantity  of  platinum.  The 
apparatus  is  then  connected  gas-tight,  and  the  funnel  tube  about 
half  filled  with  H2SO4,  diluted  with  an  equal  bulk  of  H2O,  and  cooled. 
By  opening  tbe  stopcock,  the  acid  is  brought  in  contact  with  the  ziuc 
in  small  quantities,  in  such  a  manner  that  during  the  entire  testing 
bubbles  of  gas  pass  through  d  at  the  rate  of  60-80  per  minute. 
After  fifteen  minutes  the  burner  is  liglrted,  and  the  heating  continued, 
during  evolution  of  gas  from  zinc  and  H2BO4,  for  an  hour.  At  the 
end  of  that  time,  if  no  stain  have  formed  in  cc  beyond  the  burner,  the 
zinc  and  acid  may  be  considered  to  be  pure,  and  the  suspected  solu- 
tion, which  must  have  been  previously  freed  from  organic  matter  and 
from  tin  and  antiniouy,  is  introduced  slowly  through  the  funnel -tube. 


ARSENIC 


181 


If  arsenic  be  present  in  the  substance  examined,  a  hair-brown  or 
gray  deposit  is  formed  in  the  cool  part  of  ev  beyond  the  heated  part. 
At  the  same  time  the  contents  of  d  are  darkened  if  the  amount  of  As 
present  is  so  great  that  all  the  AsII:i  produced  is  not  decomposed  in 
the  heated  portion  of  vc. 

To  distinguish  the  stains  produced  by  arsenical  compounds  from 
I  the  similar  ones  produced  by  antimony  the  following  differences  are 
noted  : 


I 


The  Arsemcal  Stain, 

F^rBi,  —  U  farther  removed  from  the 
licAted  portion  of  tlie  tube^  and,  if 
mall  in  quaotity,  is  double  —  the  irBt 
tiair-brown,  tlie  second  steel-gray. 

Sttond.  —  Volatilizes  readily  when 
iHBted  in  ail  atmosphere  of  hydrop^eo, 
being  deposited  farther  along  in  the 
tobe.  The  estcuping  gas  has  the  odor 
of  gmrlic. 

Tktrtt.  ^  When  eantionsly  heated  in  a 
SBTfvnt  of  axygeu,  bnlliant,  white, 
ttetabedral  crystals  of  arsenic  trloxid 
are  deposited  farther  along  in  the  tube, 
Fomrth,  —  Instiintly  soluble  in  solu- 
tion of  sodium  hypochlorite. 

f\fih,  —  Slowly  dispolvt'd  by  solution 
«f  smnioninm  sulf hydrate  ;  more  rap- 
Hlly  wbi»n  warmed. 

Xuik,  — The  solution  obtained  in  fire 
Irmfvs,  on  evaporation  ovt^r  the  water- 
teUi,  a  bright  yellow  residue. 

Sff«i«A,  — The  residue  olitained  in 
••<  ts  soluble  in  aqua  ammonitt',  but 
»wluble  in  hydfoehloric  acid. 

Kiif\»ih.  —  ts  soluble  in  warm  nitric 
*<i4;  t!ii»  solution  on  evaporation  yields 
ivbit^  refidue,  which  turns  brick-red 
wttD  moistened  with  silver  nitrate 
Hiliition. 

.Vmf}(«— III  not  dissolved  by  a  solu* 
ttoit  of  ttannotis  eblorid. 


The  Antinu^nial  Stain, 

Firsi.  — Is  quite  near  the  heated  por- 
tion of  the  tube.  A  second  stain  is  also 
usually  formed  in  front  of  the  heated 
part  of  the  tube. 

Second,  —  Requires  a  much  higher 
temperature  for  its  volatilization  ;  fuses 
before  volatilising.  Escaping  gas  has 
no  alliaceous  odor. 

T//i><f.  — No  crystals  formed  by  heat* 
ing  in  oxygen,  but  an  amorphous,  whit« 
subiimate  (see  p.  179 J. 

Fourth, — Insoluble  in  solution  of 
sodium    hypochlorite. 

Fifth.  —  Dissolves  quickly  in  solution 
of  ammonium  sulfbydrate. 

Sijcth.  — The  solution  obtained  in  five 
leaves,  on  evaporation  over  the  water- 
bath,  au  orange- red  residue. 

Seventh. --The  residue  obtained  in 
six  is  insoluble  in  aqua  ammoniie,  but 
soluble  tn  hydroehlorio  acid, 

Eiffhth, — Is  soluble  in  warm  nitric 
acid;  the  solution  on  evaporation  yields 
a  white  residue,  which  is  not  colored 
when  moistened  with  silver  nitrate 
solution, 

2^inth,  —  Dissolves  slowly  in  solution 
of  stannous  chlorid. 


The  silver  solution  in  d  is  tested  for  arsenous  aeid,  by  floating: 
Ql^on  its  surface  a  layer  of  diluted  NHiHO  solution,  which,  in  the 
pnaence  of  arsenic,  produces  a  yellow  (not  brown)  band,  at  the  point 
^^  junction  of  the  two  lif|nids. 

In  place  of  bending  the  tube  c  downward,  it  may  be  bent  upward 
and  drawn  out  to  a  fine  opening.  If  the  escaping  gas  be  then  ignited, 
'^^  baatinie;  of  the  tube  being  diseontinued,  a  white  deposit  of  Ag^Oa 


182  MANUAL    OF    CHEMISTRY 

may  he  collected  on  a  glass  surface  held  above  the  flame  ;  or  a  brown 
deposit  of  elementary  As  upon  a  cold  (porcelain)  shrface  held  in  the 
flame. 

In  place  of  generating  nascent  hydrogen  by  the  action  of  Zn  on 
H2SO4,  it  may  be  produced  by  the  decomposition  of  acidulated  H2O 
by  the  battery,  in  a  Marsh  apparatus  especially  modified  for  that 
purpose. 

In  another  modification  of  the  Marsh  test  the  AsHs  is  decomposed, 
not  by  passage  through  a  red-hot  tube,  but  by  passing  through  a 
tube  traversed  by  the  spark  from  an  induction  coil. 

(7)  Fresenius' and  Von  Babo's  test.  —  The  sulfid,  obtained  in 
(1),  is  dried,  and  mixed  with  12  parts  of  a  dry  mixture  of  3  pts. 
sodium  carbonate  and  1  pt.  potassium  cyanid,  and  the  mixture 
brought  into  a  tube,  drawn  out  to  a  fine  opening,  through  which  a 
slow  current  of  CO2  is  allowed  to  pass.  The  tube  is  then  heated  to 
redness  at  the  point  containing  the  mixture,  when,  if  arsenic  be 
present,  a  gray  deposit  is  formed  at  the  constricted  portion  of  the 
tube ;  which  has  the  characters  of  the  arsenical  stain  indicated  on 
p.  181. 

(8)  Place  a  small  crystal  of  sodium  sulfite  in  a  solution  of  0.3-0.4: 
gram  of  stannous  chlorid  in  pure  HCl,  sp.  gr.  1.13.  Float  the  liquid 
to  be  tested  on  the  surface  of  this  mixture.  If  As  be  present  a  yellow 
band  is  formed  at  the  junction  of  the  two  liquids,  and  gradually 
increases  upwards. 

Arsenic  Compounds. — (1)  H2S  does  not  form  a  ppt.  in  neutral 
or  alkaline  solutions.  In  acid  solutions  a  yellow  ppt.,  consisting 
either  of  AS2S3  or  AS2S5,  or  a  mixture  of  the  sulfids  with  free  S,  is 
formed  only  after  prolonged  passage  of  H2S  at  the  ordinary  tempera- 
ture, more  rapidly  at  about  TO""  (ISS""  F.). 

(2)  AgNOs,  under  the  same  conditions  as  with  the  arsenous  com- 
pounds, produces  a  brick-red  ppt.  of  silver  arsenate. 

(3)  CUSO4  under  like  circumstances  produces  a  bluish  green  ppt. 
Arsenic  compounds  behave  like  arsenous  compounds  with  the  tests 

4,  6  and  7  for  the  latter. 

Method  of  Analysis  for  Mineral  Poisons. — In  cases  of  suspected 
poisoning  a  systematic  course  of  analysis  is  to  be  followed  by  which  the 
presence  or  absence  of  all  the  more  usual  poisons  can  be  determined. 
The  most  advantageous  process  for  this  purpose  is  that  of  Fresenius 
and  Van  Babo,  somewhat  modified,  in  which  the  animal  and  vegetable 
substances  are  disintegrated  and  oxidized  by  a  mixture  of  HCl  and 
KCIO3,  and  in  which  arsenic  and  antimony,  if  present,  are  separated 
before  application  of  the  Marsh  test.  For  descriptions  of  the 
methods,  which  are  somewhat  intricate,  the  student  is  referred  to 
more  comprehensive  works. 


ANTIMOXV 


183 


ANTIMONY. 

Symbol=Hb  {Latin:  stiMum)— Atomic  ufeight=l20  {0=16:  120; 
H=l :  lid .04} "Moiecular  weight=(1  )—Sp.  gr,=6ATo—Fuses  at  450"* 
(842^  P.). 

Occurrence. — ^Fi-^e  in  smalt  quantity;   principally  iu  the  trisiilfid. 

Preparation, — The  native  sulfid  (black  or  crude  aiitimoBy)  is 
roasted,  and  then  reduced  by  heating  with  charcoal. 

Properties.— P/i?/s«ca/. — A  bluish  gray,  brittle  solid,  having  a 
naetalUe  luster;  readilj'  crystallizable;  tasteless  and  odorless;  voU- 
tillze^  at  a  red  heat,  and  may  be  distilled  in  an  atmosphere  of  H, 

Chemical. — Is  not  alttn-ed  by  dry  or  moist  air  at  ordinary  teinpera- 
ttires.  When  sufficiently  heated  in  air,  it  burns,  with  formation  of 
SbiOi,  as  a  white,  crystailine  solid.  It  also  combines  directly  with 
CI,  Br,  I,  S,  and  many  metallic  elements.  It  combines  with  II  under 
the  same  circumstances  as  does  As.  Cold  dilute  H2S04  does  not  affect 
it ;  the  hot  concentrated  acid  forms  with  it  antinionyl  sulfate 
(SbOJaSOi  and  8O2.  Hot  HCl  dissolves  it,  when  finely  divided,  with 
evolation  of  H.  It  is  readily  oxidized  by  HNO3,  with  formation  of 
HaSbOi  or  Sbj04.  Aqna  regia  dissolves  it  as  SbCls,  or  SbCIs*  Solu- 
tions of  the  alkaline  hydroxids  do  not  act  on  it. 

The  element  does  not  form  salts  with  the  oxyacids.     There  are, 

however,  compounds,  formed  by  the  substitution  of  the  group  antimo* 

nyl  (SbO) ,  for  the  basic  hydrogen  of  those  acids.    (See  Tartar  emetic) . 

It  enters  into  the  composition  of  type  metal,  anti-friction  metals, 

and  britaonia  nietal. 

Hydrogen  Antimonid — Stibin — A ntimotiin retted  hyilrogen — Stih- 
amin — Sfihonia — SbH^ — 123. — It  is  produced^  mixed  with  H,  when  a 
reducible  compound  of  Sb  is  in  presence  of  nascent  H.  It  is  obtained 
in  larger  amount  by  decomposing  an  alloy  of  400  parts  of  a  2% 
*odiam  amalgam,  and  8  parts  of  freshly  reduced,  and  dried  Bb,  by 
fi^,  in  a  current  of  COa^ 

It  is  a  colorless,  odorless,  combustible  gas,  subject  to  the  same 
Compositions  as  AsH.i;  from  which  it  differs  in  being  by  no  means 
w  poisonous,  and  in  its  action  upon  silver  nitrate  solution.  The 
*mai('Hl  gns  acts  upon  tlie  silver  salt  aecording  to  the  equation: 
<»A?N03+2AsH3+H2=Ag2+2Ag2HAsO:t+6nNO,.  and  the  precipitate 
rortiied  is  elementary  silver,  while  Ag^IlAsO:!  remains  in  the  solution. 
Itt  the  case  of  SbHa  the  reaction  is  3Ag\();,+Rl>H3=3HN03;+SbAga, 
•U  of  the  Sb  being  precipitated  in  the  bbick  silver  antimonid. 

Chlorids  of  Antimony. — Antimony  Trichlorid — Protnchhrid  or 
^^^n  of  aniiniony — SbCls— 2*26.5— is  obtained  by  passing  dry  CI  over 
•"^noeas  of  SbjSa;  by  dissolving  SbaSa  in  HCl;  or  by  distilling  mix- 


MAl^UAL    OF    CHEAilSTRV^ 


tures,  either  of  SbsSa  and  mercuric  elilorid,  or  of  Sb  aud  mercuric 
eblorid,  or  of  antimouyl  pyrosiilfate  aud  sodium  ehlorid. 

At  low  temperatures  it  is  a  solid,  crystalliue  body;  at  the  ordinary 
tL*mperature  a  yellow,  semi -solid  mass,  resembliug  butter;  at  73.2** 
(164°  FJ  it  fuses  to  a  yellow,  oily  liquid,  which  boils  at  223^ 
(433,4°  FJ.  Obtained  by  a  solution  of  Sb^Sa  in  HCl  of  the  usual 
strength ^  it  forms  a  dark  yellow  solution,  wiiich,  when  concentrated 
to  sp.  gr.  1.47,  constitutes  the  Liq.  Antimonii  chUrhU  (Br J. 

It  absorbs  moisture  from  air,  and  is  soluble  in  a  small  quantity  of 
IliO;  with  a  larger  (luaiitity  it  is  dfM^omposed,  with  precipitation  of  a 
white  powder,  powder  of  Algaroth,  whose  composition  is  SbOCl  if 
cold  H-O  be  used,  and  Sb405C32  if  the  H^iO  be  boiling.  In  H2O 
containing  15  per  cent,  or  more  HCl,  SbCla  is  soluble  without  decom- 
position. 

Antimony  Pentachlorid—SbCU— 297.5 —  is  formed  by  the  action 
of  CI,  in  excess,  upon  Sb  or  SbCl3. 

It  is  a  fuming,  colorless  liqirid.  With  a  small  quantity  of  H2O, 
and  by  evaporation  over  H2SO4,  it  forms  a  hydrate,  SbCl54H20\  which 
uppears  in  transparent,  deliquescent  crystals.  With  more  H4J,  a 
eryshilline  oxychlorid,  SbOCl.u  is  formed^  and  with  a  still  greater 
quantity,  a  white  precipitate  of  orthonntimouie  acid,  n3Sb04. 

Compounds  ol  Antimony  and  Oxygen.^ — Three  are  known,  Sb^Oa, 
8b204  and  Sb^Os. 

Antimony  Trioxid — A  n fhiwnoirs  an h ijilrkl  —  OxitJ  of  a ttttmony — 
Antimonii  oxidum  (U.  S,;  Br.) — SbjO:; — 28H — occurs  in  nature^ 
and  is  prepared  artificuilly  by  decomposing  the  oxychlorid;  or  liy 
heating  Sb  in  air. 

It  cryslallizes  in  prisms  or  in  octahedra,  and  is  isodimorphons 
with  AsaOs,  or  is  an  amorphous^  iusoluhle,  tasteless,  odorless  powder; 
white  at  ordinary  temperatures,  hut  yellow  wben  heated.  It  fnses 
readily,  and  may  be  distilled  in  absence  of  oxygen.  Heated  in  air,  it 
burus  like  tinder,  and  is  eouvertt?d  into  Sbi;04. 

It  is  reduced,  with  separation  of  8b,  when  huatcd  with  charcoal, 
or  in  H.  It  is  also  readily  oxidized  by  HNO3,  or  potassium  perman- 
ganate. It  dissolves  in  IT  CI  as  SbCb;  in  Nordhausen  sulfuric  acid, 
from  which  solution  brilliant  crystalline  plates  of  antimouyl  pyrosnl- 
fate,  (SbOJaS^O;,  separate;  and  in  solntious  of  tartaric  acid,  ami  of 
hydropotassic  tartrate  (see  Tartar  emetic).  Boiling  solutions  of  idka- 
line  hydi'oxids  convert  it  into  antimonic  acid. 

Antimony  Pentoxid — AntitKonic  a}iltt/dnd — Sb2O5^^320^is  ob- 
tained by  heating  nietantimonie  acid  to  dull  redness.  It  is  an  amor- 
phons,  tasteless,  odorless,  pale  lemon -yellow  colored  solid;  very  spar- 
ingly soluble  iu  water  and  in  acids.  At  a  red  heat  it  is  decomposed 
into  Sb'iOi  and  O. 


4 


I 


ANTIMONY 


1851 


I 
I 

I 


Antimony  Antimonate — Intermediate  oiid — Diantimmdc  tetroxid 
— Sl>.»04^3(J4 — ocoiirs  in  nature  aud  is  formed  when  the  oxids  or 
hydrates  of  Sb  are  strongly  lieated,  or  when  the  lower  stages  of  oxi- 
dation or  ihi^  sulfids  are  oxidized  by  HNO3,  or  by  fnsion  with  sodium 
nitrate.  It  is  soluble  in  II.iO  ;  but  is  decomposed  by  HCl,  hydro- 
potassic  tartrate,  and  potash. 

Antimony  Acids, — The  normal  antimonous  acid,  H:s8b03,  corre- 
sponding io  H3PO3,  is  unknown;  but  the  series  of  antimonic  acids: 
ortho,  H:tSb04;  pyro,  H4Sb207;  aud  luetai  HSbOa,  is  ccunplete,  either 
in  the  form  of  salts,  or  in  that  of  the  free  acids.  There  also  exists, 
in  its  sodium  salt,  a  derivative  of  the  lacking  antimonous  acid:  met- 
antimonous  acid,  HSbO-2. 

The  compound  stunctimes  used  in  medicine  under  the  name  irffahed 
diaphoretic  antimoinj  is  potassium  nietautimonate,  united  with  an 
excess  of  the  pentoxid:  2KSbOy,  8l>20:w  The  hydropotassie  pyroan- 
timouate,  KiiH^Sbi^OrCJAq  is  a  vabialilc  reagent  for  tlie  sodium  com- 
ponnds.  It  is  obtained  by  calciniug;  a  mixture  of  one  part  of  antimony 
with  four  parts  potassium  nitrate,  aud  fusing  the  product  with  its 
own  weight  of  potassium  carbonate. 

Sulfids  of  Antimony. — Antimony  TrisuHid — Sfisqiiitntljid  of  unii- 
mnny — Bhtrk  anfimonff — Antimooii  sulfidum  (U.  S.) — Antimonium 
nigrum  (BrJ — SbiS:i — 33fJ^'is  the  chief  ore  i>f  antimony;  aud  is 
formed  when  1128  is  passed  through  a  solution  of  t:irtar  <  nuli'*. 

The  native  sulfid  is  a  sreel-gray,  crystalline  solid;  the  artificial 
pi^Klttct,  an  orange-red»  or  brownish  red,  amorphous  powder.  The 
crude  antimony  of  counnerce  is  in  conical  loaves,  prepared  by  simple 
fusion  of  the  native  sulfid.  It  is  soft,  fusible,  readily  pulverized,  and 
has  a  bright  metallic  luster. 

Heated  in  air,  it  is  decomposed  into  SO2  and  a  lu-owu,  vitreous, 

more  or  less  traus|*arent   mass,  comijoscd  of  varying  prniiortions  of 

oxld  and  oxysullidi?,  known  as  crocus,  or  liver,  or  glass  of  antimony. 

SbjSn  is  an  anhyrid,  corresponding  to  which  are  salts  kuown  as  thio- 

«ntimonites,  having  the  general  fonnuhi  M'^HSbSy.     If  an  excess  of 

^^^n  be  boiled  with  a  solotiou  of  potash  or  soda,  a  liquid  is  obtaiued, 

^Wch  eontains  an  alkaline  thioantimonite,  aud  an  excess  of  Sb2S3. 

IfthiR  sohition  be  filtered,  aud  decompf>sed  by  an  acid  while  still  hot, 

^^  orange* col ored»  hui orphous  precipitate  is   produced,  wbieh  is  the 

Antimonium  sulfuratum  (U,  8,;  BrJ,  aud  consists  of  a  mixture,  in 

waning  proportions,  of  SbjSa  and  SbsOa-     If,  hywev<*r,  the  solution 

^  allowed   to   cool,   a   brown,   volumiuons,    amorphous   precipitate 

^P«imtf*s,  which  consists  of  antimony  trisulfid  and  trioxid,  potassium 

^fMium  snlfid,  and  alkaline  thioautimouite  in  varying  proportions; 

fiad  U  known  as  Kcrmes  minerah     If  now  the  solution  from  which 

^M  Kermes  has  heen  separated,  be  decomposed  with  H'jS04  a  reddish 


186  MANUAL    OF    CHEMISTKV 

yellow  substance  separates,  which  is  the  golden  sulfuret  of  antimony, 
and  consists  of  a  mixture  of  SbsSa  and  Sb2S5.  The  precipitate  obtained 
when  HcS  acts  upon  a  solution  of  an  antimonial  compound  is,  accord- 
ing to  circumstances,  Sh-zSz  or  Sb2S5,  mixed  with  free  S.  By  the 
action  of  HCl  on  Sb2S3,  H2S  is  produced. 

Antimony  Pentasulfid — Sb2S5 — 400 — is  obtained  by  decomposing 
an  alkaline  thioantimonate  by  an  acid.  It  is  a  dark  orange-red,  amor- 
phous powder,  readily  soluble  in  solutions  of  the  alkalies,  and  alkaline 
sulfids,  with  which  it  forms  thioantimonates. 

An  oxysulfid,  SbeSeOa,  is  obtained  by  the  action  of  a  solution  of 
sodium  thiosulfate  upon  SbCk  or  tartar  emetic.  It  is  a  fine  red  pow- 
der, used  as  a  pigment,  and  called  antimony  cinnabar  or  antimony 
vermilion. 

Action  of  Antimony  Compounds  on  the  Economy.  —  The  com- 
X)ound8  of  antimony  are  poisonous,  and  act  with  greater  or  less 
energy  as  they  are  more  or  less  soluble.  The  compound  which  is 
most  frequently  the  cause  of  antimonial  poisoning  is  tartar  emetic 
(q.  v.),  which  has  caused  death  in  a  quantity  of  three  grains,  in 
divided  doses,  although  recovery  has  followed  the  ingestion  of  half 
an  ounce  in  several  instances.  Indeed,  the  chances  of  recovery 
seem  to  be  better  with  large,  than  with  small  doses,  probably  owing 
to  the  more  rapid  and  complete  removal  of  the  poison  by  vomiting 
with  large  doses.  Antimonials  have  been  sometimes  criminally  ad- 
ministered in  small  and  repeated  doses,  the  victim  dying  of  exhaus- 
tion. In  such  a  case  an  examination  of  the  urine  will  reveal  the 
cause  of  the  trouble. 

If  vomiting  have  not  occurred  in  cases  of  acute  antimonial  poi- 
soning it  should  be  provoked  by  warm  water,  or  the  stomach  should 
be  washed  out.  Tannin  in  some  form  (decoction  of  oak  bark,  cin- 
chona, nutgalls,  tea)  should  then  be  given,  with  a  view  to  rendering 
any  remaining  poison  insoluble. 

Medicinal  antimonials  are  very  liable  to  contamination  with 
arsenic. 

Analytical  Characters  of  Antimonial  Compounds.  —  (l)  With 
HoS  in  acid  solution:  an  orange-red  ppt.,  soluble  in  NH4HS  and  in 
hot  HCl. 

(2)  A  strip  of  bright  copper,  suspended  in  a  boiling  solution  of 
an  Sb  compound,  acidulated  with  HCl,  is  coated  with  a  blue-gray 
deposit.  This  deposit  when  dried  (on  the  copper),  and  heated  in  a 
tube,  open  at  both  ends  yields  a  white,  amorphous  sublimate  (see  No. 
5,  p.  178). 

(3)  Antimonial  compounds  yield  a  deposit  by  Marsh's  test,  sim- 
ilar to  that  obtained  with  arsenical  compounds,  but  differing  in  the 
particulars  given  above  (see  No.  6,  p.  181). 


BORON  187 


IV.    BOEON  GROUP. 

BORON. 

8ynibol=B— Atomic  w€ight=ll  (0=16:11;  H=l :  10.91)— Ifofe- 
eular  weight=22  {1)=Isolated  by  Davy  in  1807. 

Boron  occurs  in  natare  in  the  borates  of  Ca,  Mg,  and  Na,  princi- 
pally as  sodium  pyroborate  (borax).  It  constitutes  a  group  by  itself; 
it  is  trivalent  in  all  of  its  compounds;  it  forms  but  one  oxid,  which 
is  the  anhydrid  of  a  tribasic  acid;  and  it  forms  no  compound 
with  H. 

It  is  separable  in  two  allotropic  modifications.  Amorphous 
boron  is  prepared  by  decomposition  of  the  oxid,  by  heating  with 
metallic  potassium  or  sodium.  It  is  a  greenish  brown  powder; 
sparingly  soluble  in  H2O;  infusible;  and  capable  of  direct  union  with 
CI,  Br,  O,  S,  and  N.  Crystallized  boron  is  produced  when  the  oxid, 
chlorid  or  flnorid  is  reduced  by  AI.  It  crystallizes  in  quadratic 
prisms;  more  or  less  transparent,  and  varying  in  color  from  a  faint 
yellow  to  deep  garnet-red;  very  hard;  sp.  gr.  2.68.  It  burns  when 
strongly  heated  in  O,  and  readily  in  CI;  it  also  combines  with  N, 
which  it  is  capable  of  removing  from  NH3  at  a  high  temperature. 

Boron  Trioxid. — Boric  or  boradc  awftydind— B2O3 — 70 — is  obtained 
by  heating  boric  acid  to  redness  in  a  platinum  vessel.  It  is  a  trans- 
parent, glass-like  mass,  used  in  blowpipe  analysis  under  the  name 
vitreous  boric  acid. 

Boric  Acids.  —  Boric  Acid  —  Boradc  acid  —  Orthoboric  acid  — 
Acidum  boricum  (U.  S.) — H3BO3  —  62 — occurs  in  nature;  and  is 
prepared  by  slowly  decomposing  a  boiling,  concentrated  solution  of 
borax,  with  an  excess  of  H2SO4,  and  allowing  the  acid  to  crystallize. 

It  forms  brilliant,  crystalline  plates,  unctuous  to  the  touch;  odor- 
less; slightly  bitter;  soluble  in  34  parts  H2O  at  10""  (50°  F.) ;  soluble 
in  alcohol.  Its  solution  reddens  litmus,  but  turns  turmeric  paper 
brown.  When  its  aqueous  solution  is  distilled,  a  portion  of  the  acid 
passes  over. 

Boric  acid  readily  forms  esters  with  the  alcohols.  When  heated 
with  ethylic  alcohol,  ethyl  borate  is  formed,  which  burns  with  a 
green  flame.  Heated  with  glycerol,  a  soluble,  neutral  ester  is 
formed,  known  as  boroglycerid,  and  used  as  an  antiseptic. 

If  H3BO3  be  heated  for  some  time  at  80°  (176°  F.),  it  loses  H2O 
nnd  is  converted  into  metaboric  acid,  HBO2.  If  maintained  at  100° 
(212°  F.)  for  several  days,  it  loses  a  further  quantity  of  H2O,  and  is 
Cf>nv<.*rted  into  tetraboric  or  pyroboric  acid,  H2B4O7,  whose  sodium 
salt  is  borax. 


188 


MANUAL    OF     CHEMISTRY 


V,  CAKBON  GROUP, 

CARBON —  SILICON. 

The  elements  of  this  group  are  bivalent  or  quadrivalent.  The 
saturated  oxid  of  eaeh  is  the  anhydrid  of  a  dibasic  acid.  They  are 
both  combustible,  and  eaeh  oeeiirs  iu  three  allotropic  forms. 


CARBON, 

Bumbol^C— Atomic  weighi=l2  (0=16:12  j  U^l:ll.9) —MoJe- 
cuhir  weigkt-^24  (T). 

OGcurrence, — Free  in  its  three  allotropic  forms  :  The  diamond 
in  octahedral  crystals  ;  in  alluvial  sand,  clay,  saudstone,  and  cou- 
glomerate  ;  graphite,  in  amorphous  or  imperfectly  crystalliut^  furms; 
amorphous,  in  the  different  varieties  of  anthracitt^  and  biluminons 
coal,  jet,  etc.  In  combination,  it  is  very  widely  distributed  in  the 
so-called  orj^'anic  substances. 

Properties. ^Diamond, — The  crystals  of  diamond,  which  is  al* 
most  pure  carbon,  are  usually  colorless  or  yellowish,  but  may  be  bine, 
^'rceu,  pink,  brown  or  black.  It  is  the  hardest  substance  known, 
autl  the  one  which  refracts  li^'ht  the  most  stroagrly.  Its  index  uf 
rtvfraction  is  2.47  to  2.70.  It  is  brittle;  a  bad  conductor  of  heat  and 
ot'  deetricity;  sp.  gr.  O.uO  to  3.ao.  When  very  strongly  heated  in  air 
it  burns,  witliout  blackening,  to  carbon  dioxid. 

Graphite  is  a  ffuin  of  carbon  almost  as  pure  as  the  diamond, 
capable  of  crystallizing  in  hexagonal  plates;  sp.  gr.  2.2;  dark  gray  in 
color;  opaque;  soft  enough  to  be  scratched  by  the  nail;  and  a  good 
conduetor  of  electricity.  It  is  also  known  as  black  lead  or  plum- 
bago. It  has  been  obtained  artiiicially,  by  allowing  molten  cast- iron, 
eoutainiijg  an  excess  of  carbon,  to  eool  slowly,  and  dissolving  the 
iniu  in  IICl.  When  oxidized  with  potassium  rhlorate  nnd  nitric  aeid 
it  yields  graphitic  acid,  CuIIjO:,. 

Amorphous  carbon  is  met  with  in  a  great  variety  of  forms,  nat- 
ural and  artificial,  in  all  of  which  it  is  black  ;  sp.  gr.  l.G-2,0;  more 
or  less  porous;  and  a  conductor  of  electricity. 

Anthracite  coal  is  hard  and  dense  ;  it  does  not  flame  when  burn- 
ing ;  is  difficult  to  kindle,  but  gives  great  heat  with  a  suitiible 
draught,  It  contains  8(M)0  per  cent,  of  carbon.  Bituminous  rual 
differs  from  anthracite  in  that*  when  burning,  it  gives  off  gases, 
which  produce  a  flame.  Some  varieties  are  quite  soft,  while  others, 
such  as  jet,  are  hard  enough  to  assume  a  high  polish.  It  is  usually 
compact   in   texture,    and   very  frequently   contains   impressions   of 


I 


^ 


CARBON 


189 


leaves,  and  other  parts  of  plants.  It  c*ontains  about  75  per  cent,  of 
carbon . 

Charcoal,  carbo  ligni,  U.  S.,  is  obtained  by  bnrning  woody  fiber, 
with  an  insufficient  supply  of  air.  It  is  brittle  and  sonorous;  has  the 
form  of  the  wood  from  which  it  was  obtained,  and  retains  all  the 
mineral  matter  pre.seut  in  the  woody  tissue.  Its  sp.  gr.  is  about  1.57. 
It  has  the  power  of  condensing  within  its  pores  odorous  substances 
and  large  quantities  of  gases  ;  90  volumes  of  ammonia,  55  of  hy- 
drogen sulfid,  9.25  of  oxygen.  This  property  is  taken  advantage  of 
in  a  variety  of  ways.  Its  power  of  absorbing  odorous  bodies  renders 
it  vahiable  as  a  disinfecting  and  filtering  agent,  and  in  the  preven- 
tion of  putrefaction  and  fermentation  of  certain  liquids.  The  efficar*y 
of  ehai*coal  as  a  filtering  material  is  due  also,  in  a  great  measure,  to 
the  oxidizing  action  of  the  oxygen  condensed  in  its  pores;  indeed,  if 
charcoal  be  boiled  with  dilute  HCl,  dried,  and  heated  to  redness,  the 
oxidizing  action  of  the  oxygen,  which  it  thus  condenses,  is  very 
energetic. 

When  small  strips  of  wood  are  heated  to  redness  in  a  current  of 
vapor  of  carbon  disulfide  or  of  hydrocarbons,  metallic  carbon  is  pro- 
duced. This  is  very  sonorous,  and  is  a  very  good  conductor  of  heat 
and  of  electricity.  The  filaments  in  incandescent  electric  lamps  are 
prepared  from  vegetable  parchment  or  bamboo  fiber  in  a  similar 
manner. 

Lamp-black  is  obtained  by  incomplete  combustion  of  some  res- 
inous or  tarry  substance,  or  natural  gas,  the  smoke  or  soot  from 
which  is  directed  into  suitable  condensing  chambers.  It  is  a  light, 
amorphous  powder,  and  contains  a  notable  quantity  of  oily  and  tarry 
material «  from  which  it  may  be  freed  by  heating  in  a  covered  vessel. 
It  is  used  in  the  manufacture  of  printer's  ink. 

Coke  is  the  substance  remaining  in  gas  retorts,  after  the  distil- 
lation of  bituminous  coal,  in  the  manufacture  of  illuminating  gas. 
It  18  a  hard,  grayish  substance,  usually  very  porous,  dense,  and 
sonorous*  When  iron  retorts  are  used,  a  portioii  of  the  gaseous 
products  are  decomposed  by  contact  with  the  hot  iron  surface,  upon 
which  there  is  then  deposited  a  layer  of  very  hard,  compact,  grayish 
carbon,  which  is  a  good  conductor  of  electricity. 

Animal  charcoal  is  obtained  by  calcining  animal  matters  in  closed 
vessels.  If  prepared  from  bones  it  is  known  as  bone-black,  carbo 
animalis,  U.  8.;  if  from  ivory,  ivory  black.  The  latter  is  used  as  a 
pigment,  the  former  as  a  decoloriziug  agent.  Bones  yield  about  60 
per  cent,  of  bone-black,  which  contains,  besides  carbon,  nitrogen 
and  the  phosphates  and  other  miu^^ral  substanees  of  the  boues.  It 
pofi9e$8es  in  a  remarkable  degree  the  power  of  absorbing  coloring 
matters.     When  its  decolorizing  power  is  lost  by  saturation  with  pig- 


190  MANUAL    OP    CHEMISTRY 

mentary  bodies,  it  may  be  restored,  although  not  completely,  by  cal- 
cination. For  certain  purposes  purified  animal  charcoal,  i.  e.,  freed 
from  mineral  matter,  carbo  animalis  purificatus,  U.  S.,  is  required, 
and  is  obtained  by  extracting  the  commei-cial  article  with  HCl,  and 
washing  it  thoroughly.  Its  decolorizing  power  is  diminished  by  this 
treatment.  Animal  charcoal  has  the  power  of  removing  from  a  solu- 
tion certain  crystalline  substances,  notably  the  alkaloids,  and  a 
method  has  been  suggested  for  separating  these  bodies  from  organic 
mixtures  by  its  use. 

All  forms  of  carbon  are  insoluble  in  any  known  liquid. 

Chemical, — All  forms  of  C  combine  with  O  at  high  temperatures, 
with  light  and  heat.  The  product  of  the  union  is  carbon  dioxid  if  the 
supply  of  air  or  O  be  sufficient;  but  if  O  be  present  in  limited  quan- 
tity, carbon  monoxid  is  formed.  The  affinity  of  C  for  O  renders  it  a 
valuable  reducing  agent.  Many  metallic  oxids  are  reduced,  when 
heated  with  C,  and  steam  is  decomposed  when  passed  over  red-hot  C: 
HoO+C=CO+H2.  At  elevated  temperatures  C  also  combines  directly 
with  S,  to  form  carbon  disulfid.  With  H,  carbon  also  combines 
directly,  under  the  influence  of  the  voltaic  arc. 

For  Compounds  of  Carbon,  see  page  262. 


SILICON. 

Symbol=Si— Atomic  mighi=2S  (0=16:28.4;  H=l:28.17)— Jfo- 
Ucular  weighi=56  (t) — Discovered  by  Davy,  1807 — Name  from  silex= 
flint. 

Also  known  as  silicium ;  occurs  in  three  allotropic  forms :  Amor- 
phous silicon,  formed  when  silicon  chlorid  is  passed  over  heated  K  or 
Na,  is  a  dark  brown  powder,  heavier  than  water.  When  heated  in 
air,  it  burns  with  a  bright  flame  to  the  dioxid.  It  dissolves  in  potash 
and  in  hydrofluoric  acid,  but  is  not  attacked  by  other  acids.  Graphi- 
toid  silicon  is  obtained  by  fusing  potassium  fluosilicate  with  alumin- 
ium. It  forms  hexagonal  plates,  of  sp.  gr.  2.49,  which  do  not  burn 
when  heated  to  whiteness  in  O,  but  may  be  oxidized  at  that  tem- 
perature, by  a  mixture  of  potassium  chlorate  and  nitrate.  It  dis- 
solves slowly  in  alkaline  solutions,  but  not  in  acids.  Crystallized 
silicon,  corresponding  to  the  diamond,  forms  crystalline  needles, 
which  are  only  attacked  by  a  mixture  of  nitric  and  hydrofluoric 
acids. 

Silicon,  although  closely  related  to  C,  exists  in  nature  in  compara- 
tively few  compounds.  It  has  been  caused  to  form  artificial  combina- 
tions, however,  which  indicate  its  possible  capacity  to  exist  in  sub- 
stances corresponding  to  those  C  compounds  commonly  known  as 


SILICON  191 

organic,  e.  g.,  silicichloroform  and  silicibromoform,  SiHCla  and 
SiHBrd. 

Hydrogen  Silicid — SiH4 — 32 — is  obtained  as  a  colorless,  insoluble, 
spontaneously  inflammable  gas,  by  passing  the  current  of  a  galvanic 
battery  of  twelve  cells  through  a  solution  of  common  salt,  using  a 
plate  of  aluminium,  alloyed  with  silicon,  as  the  positive  electrode. 

Silicon  Chlorid — SiCU — 170 — a  colorless,  volatile  liquid,  having 
an  irritating  odor;  sp.  gr.  1.52;  boils  at  59°  (138.2°  F.);  formed 
when  Si  is  heated  to  redness  in  CI. 

SilicicOxid — Silicic  anhydrid — Silex — Si02 — 60— is  the  most  im- 
portant of  the  compounds  of  silicon.  It  exists  in  nature  in  the  differ- 
ent varieties  of  quartz,  and  in  the  rocks  and  sands  containing  that 
mineral,  in  agate,  carnelian,  flint,  etc.  Its  purest  native  form  is  rock 
crystal.  Its  hydrates  occur  in  the  opal,  and  in  solution  in  natural 
waters.  When  crystallized,  it  is  fusible  with  difficulty.  When  heated 
to  redness  with  the  alkaline  carbonates,  it  forms  silicates,  which 
solidify  to  glass-like  masses,  on  cooling.  It  unites  with  H2O  to  form 
a  number  of  acid  hydrates.  The  normal  hydrate,  H4Si04,  has  not 
been  isolated,  although  it  probably  exists  in  the  solution  obtained  by 
adding  an  excess  of  HCl  to  a  solution  of  sodium  silicate.  A  gelati- 
nous hydrate,  soluble  in  water  and  in  acids  and  alkalies,  is  obtained 
by  adding  a  small  quantity  of  HCl  to  a  concentrated  solution  of 
sodium  silicate. 

Hydrofluosilicic  Acid — H2SiPe — 144 — is  obtained  in  solution  by 
passing  the  gas  disengaged  by  gently  heating  a  mixture  of  equal  parts 
of  fluorspar  and  pounded  glass  and  6  pts.  H2SO4  through  water;  the 
disengagement  tube  being  protected  from  moisture  by  a  layer  of  mer- 
cury.    It  is  used  in  analysis  as  a  test  for  K  and  Na. 

Silicon  Carbid  —  SiC — is  produced  by  the  action  of  a  powerful 
electric  current  upon  a  mixture  of  coke  and  aluminium  silicate.  It 
forms  blue  crystals,  is  very  hard,  and  is  used  as  a  polishing  agent 
under  the  name  Carborundum. 


VI.     VANADIUM  GROUP. 

VANADIUM — NIOBIUM— TANTALUM. 

The  elements  of  this  group  resemble  those  of  the  N  group,  but 
are  usually  quadrivalent. 

Vanadium — V — 51.2 — a  brilliant,  crystalline  metal;  sp.  gr.=r).5; 
which  forms  a  series  of  oxids  similar  to  those  of  N.  No  salts  of  V 
are  known,  but  salts  of  vanadyl  (VO)  are  numerous,  and  are  used  in 
the  manufacture  of  anilin  black. 


192  MANXAL    OF    CHEMISTRY 

Niobium  (Columbium) — Nb— 94 — a  bright,  steel-gray  metal;  sp. 
gr.  7.06;  which  burns  in  air  to  Nb205  and  in  CI  to  NbCls;  not  attacked 
by  acids. 

Tantalum — Ta^l83 — closely  resembles  Nb  in  its  chemical  char- 
acters. 

VII.     MOLYBDENUM   GROUP. 

MOLYBDENUM— TUNGSTEN— OSMIUM . 

The  position  of  this  group  is  doubtful;  and  it  is  probable  that  the 
lower  oxids  will  be  found  to  be  basic  in  character,  in  which  case  -the 
group  should  be  transferred  to  the  third  class. 

Molybdenum — Mo— 96— a  brittle  white  metal.  The  oxid  M0O3, 
molybdic  anUydridy  combines  with  H2O  to  form  a  number  of  acids; 
the  ammonium  salt  of  one  of  which  is  used  as  a  reagent  for  H3PO4; 
with  which  it  forms  a  conjugate  acid,  phosphomolybdic  acid,  used  as  a 
reagent  for  the  alkaloids. 

Tungsten — Wolfram — W — 184 — a  hard,  brittle  metal;  sp.  gr. 
17.4.  The  oxid,  WO3,  tungstic  anhydrid,  is  a  yellow  powder,  forming 
with  H2O  several  acid  hydrates;  one  of  which,  metatvngstic  acid,  is 
used  as  a  test  for  the  alkaloids,  as  are  also  the  conjugate  silicotung- 
siic  and  phosphofungstic  acids.  Tissues  impregnated  with  sodium 
iuvgsfate  are  rendered  uninflammable. 

Osmium — Os — 191 — occurs  in  combination  with  Ir  in  Ft  ores; 
combustible  and  readily  oxidized  to  OSO4.  This  oxid,  known  as  osmic 
acid,  forms  colorless  crystals,  soluble  in  H2O,  which  give  off  intensely 
irritating  vapors.  It  is  used  as  a  staining  agent  by  histologists,  and 
also  in  dental  practice. 


GOLD 


193 


I 


CLASS  tV*— AMPHOTERIC  ELEMENTS. 

Blements  whote  Oxids  unite  witli  W»ter«  aome  to  form  BaaeSf  otMers  to  form 
Acids ;   wbich  form  Oxyialts. 

The  elemeots  of  this  class  are  intenuediate  between  the  acidulous 
and  the  basylous  elements^  uut  only  in  tiie  ohemical  relations  of  their 
oxids,  bat  also  in  the  produets  of  their  electrolytic  dissociation. 
While  the  acidulous  elemeuts  usually  exist  iu  ionized  soliitious  in 
anions,  which  may  be  siiaple  or  conipouud,  aud  the  basyloua  elemeuls 
exist  ouly  ia  eatioot^,  which  are  always  simple,  the  amphoteric  elements 
mny  exist  iu  either  anion  or  cation .  When  they  occur  in  catiorjs  the 
ions  are  almost  always  simple,  as  triauriou,  Au'*\  diferrion,  Fe  , 
plambion,  Pe*\  etc.,  although  rarely  they  are  compound,  as  diurauy- 
lion*  UOs*'*  When  they  occur  in  anions  these  are  invariably  com- 
poaud«  as  dichroraanion,  Cr207",  permangauion,  MnOi",  ferrocya- 
nidion.  Fe(CN)e'''',  etc. 


L     GOLD   GROUP. 

GOLD. 

Symbol  =  Au  {A arum)  —  Atomic  weight  =  197  (0  =  16;.197,2; 
H=l:  195.63)— 3fr>/mi/<(r  /m^Af  =  394  (I)— Sp.  i^r  =  19.258-19.367 
—Fuses  at  V2(nf  (2192''  P.). 

Gold  forms  two  series  of  compounds;  iu  one»  AuCI,  it  is  univa- 
lent; in  the  other,  AuCla,  trivaleut.  Its  hydroxid,  auric  acidj  Au- 
(OH)ji«  corresponds  to  die  oxid,  AuaO.i.    Its  oxysaUs  are  unstable. 

It  is  yellow  or  red  by  reflected  light,  green  by  transmitted  light, 
reddish  purple  when  finely  divided;  not  very  tenacious;  softer  than 
silver;  very  malleable  and  ductile.  It  is  not  acted  on  by  H2O  or  air, 
at  any  temperature,  nor  by  any  single  acid.  It  combines  directly  with 
CK  Br,  I,  P,  Sb,  As  and  Hg.    It  dissolves  in  uitromuriatic  acid. 

Aurous  Chlorid — AuCl — is  produced  when  auric  chlorid  is  heated 
lO  18.>°  (365°  P.). 

Auric  Chlorid— Gold  frrr/Jorff/—AuCl:t^303.G— obtained  by  dis- 
iotvitig  Au  in  aqua  regia,  evaporating  at  100°  (212°  F.),  and  purify- 
ii*fir  ^>'  crystallization  from  H2O.  Deliquescent »  yellow  prisms,  very 
sol  able  iu  H2O,  alcohol  and  etlierj  readily  decomposed,  with  separa- 
tion of  Au,  by  contact  with  P,  or  with  reducing  agents.  Its  sohition, 
treated  with  the  ch  lor  ids  of  tin,  deposits  a  purple  double  stannatc  of 
Sn  aud  Au,  called  -^purple  of  Cmsius.^^  With  alkaline  chlorids  and 
with  the  chlorids  of  many  organic  nitrogenous  bases  it  forms  crystal- 
line chloraurates,  which  are  salts  of  hydrochlorauric  acid,  HAuCU, 
ftcich  as  sodium  chloraurate,  NaAuCli. 


194  MANUAL    OF    CHEMISTRY 

Analytical  Characters. — (1)  With  H2S,  from  neutral  or  acid  soln- 
tion:  a  blackish  brown  ppt.  in  the  cold;  insolable  in  HNO3  and  in 
HCl;  soluble  ill  aqua  regia,  and  in  yellow  NH4HS.  (2)  With  stan- 
nous chlorid  and  a  little  chlorin  water,  a  purple-red  ppt.,  insoluble  in 
HCl.  (3)  With  ferrous  sulfate:  a  brown  deposit,  which  assumes  the 
luster  of  gold  when  dried  and  burnished. 

.II.     IRON   GROUP. 

CHROMIUM— MANGAlSESE — IRON. 

The  elements  of  the  group  form  two  series  of  compounds.  In  one 
they  are  bivalent,  as  in  Fe^'CU  or  Mn''S04,  while  in  the  other  they 
are  quadrivalent;  but  when  quadrivalent,  the  atoms  do  not  enter  into 
combination  singly,  but  grouped,  two  together,  to  form  a  hexavalent 

rFe=-|  ▼* 
unit      I      I,  as  in  (Fe2)'^Cle,  (Cr2)^03.    They  form  several  oxids;  of 

which  the  oxid  MO3  is  an  anhydrid,  corresponding  to  which  are  acids 
and  salts.     Most  of  the  other  oxids  are  basic. 


CHROMIUM. 

Symbol  =Cr^  Atomic  weight  =,52  {0=16:52.1;  H=l:51.69)  — 
Molecular  weight=104i.l2  (?) — 8p.  gr. =6.8 — Discovered  byVattqHelin, 
1797 — Name  from  XP«fMi  =  color. 

Occurs  in  nature  principally  as  chrome  ironstone,  a  double  oxid  of 
Cr  and  Pe.  The  element  is  separated  with  difficulty  by  reduction  of 
its  oxid  by  charcoal,  or  of  its  chlorid  by  sodium.  It  is  a  hard,  crys- 
talline, almost  infusible  metal.  Combines  with  O  only  at  a  red  heat. 
It  is  not  attacked  by  acids,  except  HCl;  is  readily  attacked  by  alka- 
lies. 

Chromic  Oxid — Sesquioxid,  or  green  oxid  of  chromium — Cr203 — 
152.2 — obtained,  amorphous,  by  calcining  a  mixture  of  potassium 
dichromate  and  starch,  or,  crystallized,  by  heating  neutral  potassium 
chromate  to  redness  in  CI. 

It  is  green;  insoluble  in  H2O,  acids  and  alkalies;  fusible  with 
difficulty,  and  not  decomposed  by  beat;  not  reduced  by  H.  At  a  red 
heat  in  air,  it  combines  with  alkaline  hydroxids  and  nitrates,  to  form 
chromat,es.  It  forms  two  series  of  salts,  the  terms  of  one  of  which 
are  green,  those  of  the  other  violet.  The  alkaline  hydroxids  separate 
a  bluish-green  hydrate  from  solutions  of  the  green  salts,  and  a  bluish- 
violet  hydrate  from  those  of  the  violet  salts. 


MANGANESE  195 

Chromium  green,  ov  emerald  green,  is  a  green  hydrate,  formed 
by  decomposing  a  double  borate  of  eliromiiim  and  potassium  by  H2O* 
It  is  used  in  the  arts  as  a  substitute  for  the  arsenical  greens,  and  is 
non -poisonous. 

Chromic  Anhydrid — Acidum  chromicum  (U.  S.) — C1O3 — 100 — 
is  formed  by  decomposing  a  solution  of  potassium  dichromate  by 
excess  of  H2SO4,  and  crystallizing. 

It  crystallizes  in  deliquescent,  crimson  prisms,  very  soluble  in  H2O 
and  in  dilute  alcohol.  It  is  a  powerful  oxidant,  capable  of  igniting 
strong  alcohol. 

The  true  chromic  acid  has  not  been  isolated,  but  salts  are  known 
which  cori'espond  to  three  acid  hydrates:  H2Cr04  =  chromic  acid; 
H2Cr207=dichromic  acid ;  and  H2Cr30io=trichromic  acid. 

Chlorids. — Two  chlorids  and  one  oxychlorid  of  chromium  are 
known.  Chromous  chlorid,  CrCb,  is  a  white  solid,  soluble,  with  a 
blue  color,  in  H2O.  Chromic  chlorid,  (Cr2)Cle,  forms  large  red 
crystals,  insoluble  in  H2O  when  pure. 

Sulfates. — Atnolet  sulfate  crystallizes  in  octahedra,  (Cr)2(S04)3+ 
15  Aq,  and  is  very  soluble  in  H2O.  At  100°  it  is  converted  into  a 
green  salt,  (Cr)2(S04)3+5  Aq,  soluble  in  alcohol;  which,  at  higher 
temperatures,  is  converted  into  the  red,  insoluble,  anhydrous  salt. 
Chromic  sulfate  forms  double  sulfates,  containing  24  Aq,  with  the 
alkaline  sulfates.     (See  Alums.) 

Analytical  Characters. — Chromous  Salts. — (1)  Potash:  a  brown 
ppt.  (2)  Ammonium  hydroxid:  greenish  white  ppt.  (3)  Alkaline 
sulfids:  black  ppt.     (4)  Sodium  phosphate:  blue  ppt. 

Chromic  Salts. — (1)  Potash:  green  ppt.;  an  excess  of  precipitant 
forms  a  green  solution,  from  which  Cr203  separates  on  boiling.  (2) 
Ammonium  hydroxid:  greenish-gray  ppt.  (3)  Ammonium  sulfhy- 
drate:  greenish  ppt. 

Chromater. —  (1)  H2S  in  acid  solution:  brownish  color,  changing 
to  green.  (2)  Ammonium  sulfhydrate:  greenish  ppt.  (3)  Barium 
thlorid:  yellowish  ppt.  (4)  Silver  nitrate:  brownish  red  ppt.,  soluble 
itt  HNO3  or  NH4HO.  (5)  Lead  acetate:  yellow  ppt.,  soluble  in  potash, 
insoluble  in  acetic  acid. 


MANGANESE. 

B^nibol=^JilLn— Atomic  weight=55  (0=16:55;  H=l : 54.56)— ilfo- 
Mir  iret^*f=110  {1)—8p.  flrr.=7.138-7.206. 

Occurs  chiefly  in  pyrolusite,  Mn02,  hausmanite,  MuaOi,  braunite, 
^DtOa,  and  manganite,  Mn20a,  H2O.  A  hard,  grayish,  brittle  metal; 
^ible  with  difficulty;  obtained  by  reduction  of  its  oxids  by  C  at  a 


106 


M-Us'L'AL    OF    CIIEMISTKr 


1| 


white  heat.     It  is  not  readily  oxidized  by  cold,  dry  air;   but  is  super-" 
fieially  oxidized  when  heated.     It  decomposes  H2O,  iiberatiag  H,  and 
dissolves  in  dilute  acids. 

Oxids. — Manganese  forms  six  ox  ids,  or  eompounds  representing' 
them:  Mangaoous  oxid,  MiiO;  nianganoso-manganic  oxid,  Mn:jO:; 
manganic  oxid,  Mn-iO^;  permanganic  oxid,  MnO-j,  and  permangaric 
anhydrid,  MuaO-,  are  known  free.  Manganic  anhydrid,  MiiOa,  has 
not  been  isolated.  MiiO  and  Mn^-Oa  are  basic;  ]Mn304  and  Mn02  are 
indifferent  oxids;  and  Mn03  and  M02O7  are  anhydrids,  correspondiTtg 
to  the  manganates  and  permanganates. 

Permanganic  oxid — Mftngmiese  tUortd,  or  hhick  ()i*i(Z— Mangani 
oxidum  nigrum  (U.  8 J  ;  Manganesii  ox.  nig.  (Br.) — M11O2— 86— 
exists  in  nature  as  pyrolusite,  the  prineipa!  ore  of  manganese,  in 
steel  gray,  or  brownish  black,  imperfectly  crystalline  masses. 

At  a  red  heat  it  loses  12  per  cent,  of  O:  3MnO2=Mnn04+O2:  and 
at  a  white  heat,  a  further  quantity  of  O  is  given  off:  2Mnj04= 
6MnO+02.  Heated  with  H2SO4,  it  gives  oflf  O,  and  forms  manga- 
nous  sulfate;  2Mn02+2n'2SO.|=2MnS04+2HiO+02.  With  HC!  it 
yields  mangauous  chlorid,  H3O  and  CI:  Mn02+4HCl  =  MnCl2+ 
2H2O+CI2,     It  is  not  acted  on  by  HNOa.  M 

Chlorids.^ — Two  ehlorids  of  Mu  are  known:   manganous  chlorid.^" 
MnCl2»  a  pink,  deliquescent,  soluble  salt,  occurring,  mixed  with  ferric 
chloride  in  the  waste  liquid  of  the  preparation  of  CI;   and  manganic 
chlorid,  Mn2ClB. 

Salts  of  Manganese.— Manganese  forms  two  series  of  salts: 
Manganous  salts,  containing  Mn^';  and  manganic  salts,  containing 
(Mu'i)^^i  the  former  are  colorless  or  pink,  and  soluble  in  water;  the 
latter  are  unstable.  H 

Manganous  Sulfate— Mangani  sulfas  (U,  S.)— MnSOi+nAq — 
ISO+iilS^-is  formed  by  the  action  of  H-SOi  ou  Mn02.  Below  C^ 
(-'2.8^  P.)  it  crystallizes  with  7  Aq,  and  is  isomorpbous  with  ferrous 
sulfate;  between  7^-20°  {44.6^-68°  F.)  it  forms  crystals  with  5  Aq, 
and  is  isomorpbous  with  cupric  sulfate;  between  20°-30°  (68°-86°  FJ 
it  crystallizes  with  4  Aq.  It  is  rose -colored,  darker  as  the  proportion 
of  Aq  increases,  soluble  in  H2O,  insoluble  in  alcohol.  With  the  ^ 
alkaline  sulfates  it  forms  double  salts,  with  6  Aq.  ^ 

Analytical  Characters.— Manganous. —  (1)  Potash:  white  ppt.» 
turning  brow^i.  {2)  Alkaline  carbonates:  white  ppts.  (3)  Ammo- 
nium sulfbydrate:  flesh  -  colored  ppt.,  soluble  in  acids,  sparingly  soluble 
in  excess  of  precipitant.  (4)  Potassium  ferrocyanid;  faintly  reddish 
white  ppt.,  in  neutral  solution;  soluble  in  HCl.  (5)  Potassium 
cyauidt  rose-colored  ppt.  forming  brown  solution  with  excess.  m§ 

Manganic  — {1)  H2B:  ppt.  of  sulfur,  (2)  Ammonium  sulf hydrate: 
flesh -colored  ppt.    (3)  Potassium  ferrocyauid:  greenish  ppt.    (4)  Po- 


IBON  197 

Kitun  ferricyanid:  brown  ppt.  (5)  Potassium  cyanid:  light  brown 
ppt. 

Hakqanates — are  green  salts,  whose  solutions  are  only  stable  in 
presence  of  excess  of  alkali,  and  turn  brown  when  diluted  and  acidu- 
lated. 

Permanganates — form  red  solutions,  which  are  decolorized  by 
80j,  other  reduciuif  agents,  and  many  organic  substances. 


IRON. 

}fmhol  ==  Pe  {Femim)  —  Atomic  teeight^56  ( 0  ^  16 :  56  ;  H= 
l:bb.oQ)^Malecular  umgkt=lll.S  (!)— >S/>.  g r.=l. 25-7 S— Fuses  at 
1600**  (2912'*  F.)— Name  from  the  8amn,  iren. 

Occurrence,— Free,  in  small  quantity  only,  in  platinum  ores  and 
meteorites.  As  Fe-iOa  in  red  hiBmatite  and  specular  iron;  as  hydrates 
of  FegOa  in  brawn  hmmatite  and  oiJiitH'  iron;  as  FeaO^  in  magnetic 
iram;  as  FeCOa  in  spathic  irtm,  chi^  iroustone  and  bog  ore;  and  as 
FeSa  in  pyrites.  It  is  also  a  tionstituent  of  most  soils  and  clays, 
exists  in  many  mineral  waters »  and  in  the  red  blood  pigment  of  ani- 
mals. 

Preparation. — In  working  the  ores,  reduction  is  first  effected  in  a 

hhist  furnace,  into  which  alternate  layers  of  ore,  coal  and  limestone 

are  fed  from  the  top,  w^hile  air  is  forced  in  from  below.     In  the  lower 

part  of  the  furnace  CO2  is  produced,  at  the  expense  of  the  coal; 

higher  up  it  is  reduced  by  the  incandescent  fuel  to  CO,  which,  at  a 

still  higher  point,  rednees  the  ore.     The  fused  metal,  so  liberated^ 

<'oUects  at  the  lowest  point,  under  a  layer  of  slag;  and  is  drawn  off  to 

be  cast  as  pig  irmi.     This  product  is  then  purified,  by  burning  out 

impurities,  in  the  process  known  as  pnfldling. 

Pure  fro9i  is  prepared  b}'  reduction  of  ferrous  chlorid,  or  of  ferric 
♦iJtid,  by  H  at  a  temperatm^  approaching  redness. 

Varieties*^ — Cast  iron  is  a  brittle,  white  or  gray,  crystalline  metal, 
''^mHij^ting  of  FeSn-DOfr^;  C  1-4.5%:  and  Si,  P,  S,  and  Mn.  Af^  pig 
♦^N,  it  is  the  product  of  the  blast-furnace, 

Wrought^  or  bar  iron,  is  a  fibrous,  tough  metal,  freed  in  part  from 
^f  imimrities  of  cast  iron,  by  refining  and  puddiiHg, 

^eel  is  Fe  combined  with  a  quantity  of  C,  less  than  that  existing 
'^'  c«iat  iron,  and  ^eater  than  that  in  bar  iron.  It  is  prepared  by 
**"wiitoff<?n;  which  cousists  in  causing  bar  iron  to  combine  with  C; 
^'W'tlie  Bessemer  mef  1ml;  w-hich,  as  now  used,  consists  in  burning 
"^^'Cout  of  molten  cast  iron,  to  which  the  proper  proportion  of  C  is 
tkea  added  in  the  shape  of  spiegel  eisen,  an  iron  rich  in  Mn  and  C, 
The  purest  forms  of  commercial  iron  are  those  used  in  piano- 


19:  MANUAL    OF    CHEMISTRY 

strings,  the  teeth  of  carding  machines  and  electro  magnets;  known  as 
soft  iron. 

Reduced  iron — Ferrum  reductum  (U.  S.) — Fer.  redactum  (Br.) 
— is  Fe,  more  or  less  mixed  with  Pe203  and  Fe304,  obtained  by  heat- 
ing Fe203  in  H. 

Properties. — Physical. —  Pure  iron  is  silver  white,  quite  soft; 
crystallizes  in  cubes  or  octahedra.  Wrought  iron  is  gray,  liard,  very 
tenacious,  fibrous,  quite  malleable  and  ductile,  capable  of  being 
welded,  highly  magnetic,  but  only  t-eraporarily  so.  Steel  is  j^ray,  very 
hard  and  brittle  if  tempered,  soft  and  tenacious  if  not,  permanently 
magnetic. 

Chemical, — Iron  is  not  altered  by  dry  air  at  the  ordinary  tem- 
perature. At  a  red  heat  it  is  oxidized.  In  damp  air  it  is  converted 
into  a  hydrate,  iron  rust,  Tinplate  is  sheet  iron,  coated  with  tin; 
galvanized  iron  is  coated  with  zinc,  to  preserve  it  from  the  action  of 
damp  air. 

Iron  unites  directly  with  CI,  Br,  I,  S,  N,  P,  As,  and  Sb.  It  dis- 
solves in  HCl  as  ferrous  chlorid,  while  H  is  liberated.  Heated  with 
strong  H2SO4,  it  gives  off  SO2;  with  dilute  H2SO4,  H  is  given  off  and 
ferrous  sulfate  formed.  Dilute  HNO3  dissolves  Fe,  but  the  concen- 
trated acid  renders  it  passive,  when  it  is  not  dissolved  by  either  con- 
centrated or  dilute  HNO3,  until  the  passive  condition  is  destroj'^ed  by 
contact  with  Pt,  Ag  or  Cu,  or  by  heating  to  40°  (104°  F.). 

Compounds  of  Iron. — Oxids. — Three  oxids  of  iron  exist  free: 
FeO;  Fe203;  Ff^Ov. 

Ferrous  Oxid. — Prof  arid  of  iron — FeO — 72 — is  formed  by  heating 
Fe203  in  CO  or  CO2. 

Ferric  Oxid. — Sesquioxid  or  peroxid  of  iron — Colcothar — Jeweler^ s 
rouge — Venetian  red — Fe203 — 160 — occurs  in  nature  (see  above),  and 
is  formed  when  ferrous  sulfate  is  strongly  heated,  as  in  the  manu- 
facture of  pyrosulfnric  acid.  It  is  a  reddish,  amorphous  solid,  is  a 
weak  base,  and  is  decomposed  at  a  white  heat  into  O  and  Fe304. 

Magnetic  Oxid — Black  oxid — Ferri  oxidum  magneticum  (Br.) — 
Fe304 — 232 — is  the  natural  loadstone,  and  is  formed  by  the  action  of 
air,  or  steam,  upon  iron  at  high  temperatures.  It  is  probablj'  a  com- 
pound of  ferrous  and  ferric  oxids  (FeO,  FeoOs),  as  acids  produce  with 
it  mixtures  of  ferrous  and  ferric  salts. 

Hydrates. — Ferrous. — When  a  solution  of  a  ferrous  salt  is  de- 
composed by  an  alkaline  hydroxid,  a  greenish -white  hydroxid, 
FeH202,  is  deposited;  which  rapidly  absorbs  O  from  the  air,  with 
formation  of  ferric  hydroxid. 

Ferric. — When  an  alkali  is  added  to  a  solution  of  a  ferric  salt,  a 
brown,  gelatinous  precipitate  is  formed,  which  is  the  normal  ferric 
hydroxid  (Fe)2H606  =  Ferri   peroxidum   hydratum   (U.   S.)  ;    Fer. 


IRON 


199 


perox.  humidum  (Br J.  It  is  oot  fonnod  iu  the  presence  of  fixed 
<ir^aijiL'  aeid^s,  or  of  sugar  in  siifficieat  quantity.  If  preserved  ooder 
HiOr  it  is  partly  oxidized,  forming  an  oxyliydrate  which  is  incapable 
uf  furmiu^  ferrous  arsenate  with  AsiO;?. 

If  the  hydroxid  (Fes)  H«0,^  be  dried  at  1(X)^  (212''  F.),  it  loses 
2H:»0,  and  is  converted  into  (Fej)02,  HaO^*  wliieh  is  the  Ferri  ptroxi- 
dum  hydmtum  (Br.). 

If  the  norraal  hydroxid  be  dried  in  vacuo,  it  is>  converted  into 
(Fe2)jHiiOfl,  and  this,  when  boiled  for  some  horn's  with  11  iO,  is  con* 
verted  into  the  colloid  or  modified  hydrate  (Fe-jH-O*  {?},  whieh  is 
I>rick-red  in  color,  almost  insokibh'  in  HNOa  and  HCl,  gives  no 
Prussian  blue  reaction,  and  forms  a  turbid  solution  with  acetic  acid. 
If  recently  pi^eripitated  ferric  hydroxid  be  dissolved  in  solntion  of 
ferric  ehlorid  or  acetate,  and  subjected  to  dialysis,  alniost  all  the  acid 
passes  out,  leaving  in  the  dialyzer  a  dark  red  solution,  which  prob- 
ably cont^ains  this  colloid  hydrate,  and  which  is  instantly  coagulated 
by  a  trace  of  H2SO4,  by  alkalies,  many  salts,  and  by  heat;  dialyzed 
iron. 

Ferric  Acid. — HoFeO*, — Neither  the  free  acid  nor  the  oxid,  FeOa» 
h  known  in  the  free  state;  the  ferrates,  however,  of  Na,  K»  Ba,  Sr, 
iind  Ca  are  known. 

Siilfids.  —  Ferrous  SMlfid—Proiosulfid  of  irmi  —  FeS  —  88  —  is 
formed  : 

(1)  By  heating  a  mixture  of  finely-divided  Fe  and  S  to  redness; 
(2)  by  pressing  roll -sulfur  on  white-hot  iron;  (3)  in  a  hydrated  con* 
4ilioQ,  FeS,  H2O.  by  treating  a  solution  of  a  ferrous  salt  with  an 
Valine  sulf hydrate. 
The  dry  snlfid  is  a  brownish,  brittle,  magnetic  solid,  insoluble  in 
H3O,  soluble  in  acids  with  evolution  of  H2B.  The  hydrate  is  a  black 
powder,  which  absorbs  O  from  the  air,  turning  yellow,  by  formation 
<»f  FetrOti,  and  liberation  of  S.  It  occurs  in  the  fa?ee8  of  pei^ons 
taking  chalybeate  waters  or  preparations  of  iron. 

Ferric  Sulfid  —  Sesquisulfid — ^Fe-iSa — 208 — occurs  in  nature  in 
ft>pper  pyriifM,  and  is  formed  when  the  disulfid  is  heated  to  redness. 

Ferric  Disulfid — PeS-j — 120 — occurs  in  the  white  and  yt'How  Mar- 
Unlp^riffift,  used  in  tbe  manufacture  of  H2SO1.  When  heated  in  air* 
it  Is  decomposed  into  SO2  and  mitgnctk  pyrites  :  3FeS2+202=Fe3S4-|- 
2J<07. 

Chlorids*  —  Ferrous  Chlorid  —  Protochlorkl  — FeClg— 126.9  —  is 
l»Muced:  (1)  by  passing  dry  HCl  over  rcd*hot  Fe;  (2)  by  hcatiuir 
f^rrifi  phlorid  in  H;  (3)  as  a  hydrate,  FeCl2.  4H2O,  by  dissolving 
'^*' in  HCL 

Th»»  anhydrous  conipouud  is  a  yellow,  crystalline,  volatile,  and 
^«fy  soluble  solid.      The  hydrated  is  in  gi'eeuish,   oblique  rhombic 


200 


MANUAL    OF    CHEMISTRY 


h(9 

"1 


prisms,  deliquescent  and  very  soluble  in  H2O  and  alcohol.     When 
heated    in    air  it   is   converted   into   ferric    chlorid,    and    an    oxy- _ 
ehlorid.  H 

Ferric  Chlond — SesquicMorid—Perchlorid—Fttri  chlondum  (U. 
Sj^Fe-iCU— 324»7^ — is  produced,  in  the  anhydrouis  form,  by  heating 
Pe  in  CL  As  a  hydrate,  FesCla,  4H2O,  or  FeaCle,  6H2O,  it  is  formed : 
(1)  by  solution  of  the  anhydrous  coiupound;  (2)  by  dissolving  Fe  ii 
aqua  regia;  (3)  by  dissolving  ferric  hydroxid  in  HCl ;  (4)  by  the 
action  of  CI  or  of  HNO3  on  solution  of  ferrous  chlorid.  It  is  by  th€ 
last  tnethod  that  the  pharmaceutical  product  is  obtained. 

The  anhydrous  compound  forms  reddish -violet,  ci'j^stalline  plates, 
very  deliquescent.  The  hydrates  form  yellow,  nodular,  imperfectly 
crystalline  masses,  or  rhombic  plates,  very  sohible  iu  H2O,  soluble  in 
alcohol  and  ether.  In  sohition,  it  is  converted  into  FeCb  by  reducing 
agents.  The  Liq,  ferri  chloridi  (U.  S,)=Liq.  fen  pcrchloridi  (Br.) 
is  an  aqueous  solution  of  this  compound,  containing  excess  of  aoid..^ 
The  Tinct.  fer.  chlon  {U.  S.)  and  Tinct,  fer,  perchl.  (Br J  are  thdl 
solution,  diluted  with  alcohol,  and  contain  ethyl  chlorid  and  ferrous 
chlorid. 

Bromids. — Ferrous  Bromid — FeBi*2 — 215.9 — is  formed  by  thf 
action  of  Br  on  excess  of  Fe,  in  presence  of  H2O. 

Ferric  Bromid^Fe^Brg — 591,7 — is  prepared  by  the  action  of  ex-i 
cess  of  Br  on  Fe. 

lodids.— Ferrous  lodid— Ferri  iodidum  (II.  S.;  Br.)— -Feh— JWJ.f"* 
— is  obtained,  with  41120,  by  the  action  of  I  upon  excess  of  Fe  in  the 
presence  of  warm   H2O.     When  anhydrous,   it  is  a  white  powder; 
hydrated,  it  is  in  green  crystals.     In  air  it  is  rapidly  decomposed,^- 
more  slowly  in  the  presence  of  sugar.  H 

Ferric  lodld — Fenle— 873 — is  formed  by  the  action  of  excess  of  I 
on  Fe. 

Salts  of  Iron, — Sulfates. "-^Ferrous  Sulfate — Prot4>st4lfaie — ^Green 
vitriol— Copperas— Ferri  sulfas  (U.S.;  Br.)— FeSOi+TAii— 152+ 
126 — is  formed:  (1)  by  oxidation  of  the  sulfid,  FeiiS*,  formed  in 
the  manufacture  of  H^SO^;   (2)  by  dissolving  Fe  in  dilute  H^BOi,        fl 

It  forms  green,  efflorescent,  oblique  rhombic  prisms,  quite  soluble^ 
in   H2O,   insoluble    in   alcohol.     It    loses   6   Aq  at    lOO*"   (212''  FJ 
(Ferr,  sulL  exstccatuSy  U,  S.);  and  the  last  Aq  at  about  300 "^  (572 
F,),     At  a  red  heat  it  is  decomposed  into  Fe^Oa;  SO2  and  8O3.     By 
exposure  to  air  it  is  gradually  converted  into  a  basic  ferric  sulfate 
(Fe2){S04):i,  rjFeoOn. 

Ferric  Sulfates  are  quite  numerous,  and  are  formed  by  oxidations 
of  ferrous  sulfate  under  different  conditions.  The  normal  sulfat^,^ 
(Fe^)(SOt)n,  is  formed  by  treating  solution  of  FeSOi  with  HNOi, 
and  evaporating,  after  addition  of  one  molecule  of  H28O4  for  each 


1 


1 


IKON 


201 


two  moIeciileB  of  FeSOi.  The  Liq,  fer.  tersulfatis  (U,  S,),  contains 
this  salt.     It  is  a  yellowish  white,  amorphous  solid. 

Of  the  many  basic  ferric  sulfates,  the  only  one  of  medical  in- 
terest is  Monsers  salt,  5(Fe2)(S04)3+4Fe203,  which  exists  in  tho 
Liq.  ferri  snbsulfatis  (U.  SJ  and  Liq,  fer- pcrsulfatis  (Br.).  Its 
solution  is  decolorized,  and  forms  a  white  deposit  with  excess  of 
H2SO4. 

Nitrates*— Ferrous  Nitrate — Fe  (NOa)^— ^179.1 — a  greenish,  un- 
stable salt,  formed  by  double  decomposition  between  barium  nitrate 
and  ferrous  sulfate;  or  by  the  action  of  HNOa  on  FeS, 

Ferric  Nitrates.  —  The  ftormal  nifraie — ( Fes )(N0:i)6— 484.2— iB 
obtained  in  solution  by  dissolving  Fe  in  HNO3  of  sp.  err.  1.115:  or 
by  dissolving  ferric  hydroxid  in  HNO:j,  It  therefore  exists  in  the 
Liq.  ferri  niiraiis  (U.  8.),  It  crystallizes  in  rhombic  prisms  with  18 
Aq,  or  in  cubes  with  12  Aq. 

Several  basii^  nitrates  are  known,  all  of  which  are  uncrystaltizable, 
and  by  their  pi-esence  (as  when  Fe  is  dissolved  in  HNO3  to  satura- 
tion) prevent  the  crystallization  of  the  normal  salt. 

Phosphates,— Triferrous  Phosphate — Feg ( PO4 )2— 358.=A  white 
precipitate,  formed  by  adding  diaodie  phosphate  to  a  solution  of  a 
ferrous  salt,  in  presence  of  sodium  acetate.  By  exposure  to  air  it 
turns  blue;  apart  being  converted  into  ferric  phosphate,  The/errt 
phosphas  (Br.)  is  such  a  mixture  of  the  two  salts.  It  is  insoluble  in 
H2O;  sparingly  soluble  in  XIjO  containing  carbonic  or  acetic  acid* 

It  is  probably  this  phosphate,  capable  of  turning  blue,  which 
sometimes  occurs  in  the  lungs  in  phthisis^  in  blue  pus,  and  in  long- 
buried  bones. 

Ferric  Phosphate — (Pe^)(P04)2 — 302 — is  produced  by  the  action 
of  an  alkaline  phosphate  on  ferric  chlorid.  It  is  soluble  in  HCl, 
HNO3,  citric  and  tartaric  acids,  insoluble  in  phosphoric  acid  and  in 
solution  of  disodir  phosphate.  The  ferri  phosphas  (U.  S.)  is  a 
compound,  or  mixture  of  this  salt  with  disodic  citrate,  which  is  sol- 
rsble  in  water. 

There  exist  quite  a  number  of  basic  ferric  phosphates. 

Ferric  Pyrophosphate — ^{Fe2)2(p207)3 — 746 — is  precipitated  by 
decomposition  of  a  solution  of  a  ferric  compound  by  sodium  pyro- 
phosphate; an  excess  of  the  Na  salt  dissolves  the  precipitate  when 
warmed,  and,  on  evaporation,  leaves  the  scales  of  a  double  salt, 
(Fe-)-  (P207)3,  Nan (PitOt) 2+20  Aq. 

The  ferri  pyrophosphas  (U.  S.)  is  a  mixture  of  ferric  pyrophos- 
phate, trisodie  citrate,  and  ferric  citrate. 

Acetates. — Ferrous  Acetate — Fe(C2H302)2 — ^174-^18  formed  by 
decomposition  of  ferrous  sulfate  by  calcium  acetate,  in  soluble,  silky 
needles. 


202 


MANUAL    OP    CHEMISTRY 


Ferric  Acetates. — The  normal  salt  (Fe2)(C2HaO'i)6»  is  obtained  hy 
adding  slight  excess  of  ferric  sulfate  to  lead  acetate,  and  deeantiug 
lifter  twenty -four  hours.  It  is  dark -red,  uiicrystallizalde,  very  &ol- 
tible  ill  aleohol,  and  in  H2O.  If  its  solution  be  heated  it  darkens 
suddenly,  gives  off  aeetie  acid,  and  contains  a  basic  acetate.  Wben 
boiled,  it  loses  all  its  acetic  aeid,  and  deposits  ferric  hydrate.  When 
heated  in  closed  x'cssels  to  KK)"^  (212^^  FJ,  and  ti^eated  with  a  trace  of 
mineral  acid,  it  deposits  the  modified  ferric  hydrate. 

Ferrous  Carbonate — PeCOs  — Spathic  iron — clay  irmtstone — bog 
ore — 116— occurs  as  an  ore  of  iron,  and  is  obtained,  in  a  hydrated 
form,  by  adding  an  alkaline  carbonate  to  n  ferrous  salt.  It  is  a 
greenish,  amorphous  powder,  wbir-h  on  exposure  to  air  turns  red  by 
formation  of  ferric  hydrate;  a  rhangc  whi^-h  is  retarded  by  the  pi-es- 
ence  of  sugar,  hence  the  addition  of  that  substance  in  the  fern  car- 
bonas  saccharatos  {U.S.;  BrJ.  It  is  insoluble  in  pure  H2O,  but 
soluble  in  H2O  containing  carbonic  acid,  probably  ns  ferrous  bicar- 
bonate, H^FeiCO^)^,  in  which  form  it  occurs  iu  chalybeate  waters. 

Ferrous   Lactate— Ferri    lactas    (U.   SJ— Fe(r:,Hr.O:/)2+3  Aq— 
234+rj4 — is  formed  when  iron  filings  are  dissolved  in  lactic  acid.     It 
crystallizes  in  greenish  yellow  needles;  soluble  in  H2O;  insoluble  in* 
alcnboi ;  permanent  in  air  when  dry. 

Ferrous  Oxalate— Ferri  oxalas  (U.  8.)  FeCj04+2Aq— 144+36— is 
a  yellow,  crystalline  powder  j  sparingly  Boluble  iu  H2O;  formed  by 
4lissolving  iron  filings  in  .solution  of  oxalic  acid. 

Tartrates  —  Ferrous  Tartrate  —  FeC4H40a+2Aq  —  204+36.  —  A 
white,  crystalline  powder;  formed  by  dissolving  Fe  in  liot  cooeeu* 
trated  solution  of  tartaric  acid. 

Ferric  Tartrate— Fe2(C4li40<j)3+3Aq— 556+54.— A  dirty  yellow, 
amorphous  mass,  obtained  by  dissolving  recently  precijntated  ferric 
hydroxid  iu  tartaric  acid  solution,  and  evaporating  below  59 "^  (122° 

fV). 

A  number  of  double  tartrates,  contjiiniug  the  group  (Fc^jOe)'  are 
also  known.  Such  are:  Ferrico-ammonic  tartrate=  ferri  et  ammonii 
tartras  (U.  S.),  (C4H40(j)2(Fe202),{NIl4>^+4AQ,  aud  Fcrrico-potassic 
tartrate  =  ferri  et  potassii  tartras  ( U .  S . ) ,  ( (^i+HiOa )  •>  ( Fe202 )  K^. 
They  are  prepared  by  dissolving  recently  precipitated  ferric  bydroxid 
in  hot  solutioas  of  the  hydro- alkaline  tartrate.  They  only  react  with 
terrt>cyanid8  and  thioeyauates  aftei'  addition  of  a  mineral  acid. 

Citrates.— Ferric  Cifa^ate— Ferri  citras  (U.  8.)— (Fes)  (C6H507)2+ 
6Aq — 490+108— is  in  garnet-colowd  scales,  obtained  by  dissolving 
terric  hydrate  in  solution  of  citric  acid,  and  evaporating  the  solution 
lit  about  a)"  (140°  F.).  It  loses  3Aq  at  120''  (248^^  F.),  and  the 
r#tUttinder  at  150°  (302°  F.).  If  a  snudl  quantify  of  ammonium 
kiydraxid  l>e  added,  before  the  evaporation,  the  product  consists  of 


\ 


URANIUM  203 

the  modified  citrate=£eiTi  et  ammonii  citras  (U.  S.),  which  only 
reacts  with  potassium  ferrocyanid  after  addition  of  HCl. 

The  various  citrates  of  iron  and  alkaloids  are  not  definite  com- 
pounds. 

Ferric  Ferrocyanid— Prussian  blue — (Fe2)2(FeC6N6)3+18Aq  — 
860+324 — is  a  dark -blue  precipitate,  formed  when  potassium  ferro- 
cyanid is  added  to  a  ferric  salt.  It  is  insoluble  in  H2O,  alcohol  and 
dilute  acids  ;  soluble  in  oxalic  acid  solution  (blue  ink) .  Alkalies 
turn  it  brown. 

Ferrous  Ferricyanid — Turnbull's  blue — Fe8(Fe2Ci2Ni2)+nAq — 
592+nl8 — is  a  dark  blue  substance  produced  by  the  action  of  potas- 
sium ferricyanid  on  ferroug  salts.  Heated  in  air  it  is  converted  into 
Prussian  blue  and  ferric  oxid. 

Analytical  Characters. — Ferrous — ^Are  acid;  colorless  when  an- 
hydrous, pale  green  when  hydrated;  oxidized  by  air  to  basic  ferric 
compounds.  (1)  Potash:  greenish  white  ppt. ;  insoluble  in  excess; 
changing  to  green  or  brown  in  air.  (2)  Ammonium  hydroxid; 
greenish  ppt.;  soluble  in  excess;  not  formed  in  presence  of  ammo- 
niaeal  salts.  (3)  Ammonium  sulfhydrate  :  black  ppt.;  insoluble  in 
excess;  soluble  in  acids.  (4)  Potassium  ferrocyanid  (in  absence  of 
ferric  salts):  white  ppt.;  turning  blue  in  air.  (5)  Potassium  ferri- 
cyanid: blue  ppt.;  soluble  in  KHO;  insoluble  in  HCl. 

Ferric — Are  acid,  and  yellow  or  brown.  (1)  Potash,  or  ammo- 
nium hydroxid:  voluminous,  red-brown  ppt.;  insoluble  in  excess. 
(2)  Hydrogen  sulfid,  in  acid- solution  :  milky  ppt.  of  sulfur;  ferric 
reduced  to  ferrous  compound.  (3)  Ammonium  sulfhydrate  :  black 
ppt.  ;  insoluble  in  excess  ;  soluble  in  acids.  (4)  Potassium  ferro- 
cyanid: dark  blue  ppt.;  insoluble  in  HCl;  soluble  in  KHO.  (5)  Po- 
cassium  thiocyanate:  dark -red  color;  prevented  by  tartaric  or  citric 
acid  ;  discharged  by  mercuric  chlorid.  (6)  Tannin  :'  blue -black 
color. 


HI.     URANIUM   GROUP. 

URANIUM. 

8ymbol=llr— Atomic  iceight=2S9.lJ  (0=16:239.5;  H=l:237.6) 
— 8p.  gr,=18A— Discovered  by  Klaproth  (1789). 

This  element  is  usually  classed  with  Fe  and  Cr,  or  with  Ni  and 
Co.  It  does  not,  however,  form  compounds  resembling  the  ferric;  it 
forms  a  series  of  well-defined  uranates,  and  a  series  of  compounds  of 
the  radical  nranyl  (UO)'.  Standard  solutions  of  its  acetate  or 
nitrate  are  used  for  the  quantitative  determination  of  H3PO4. 


204 


MANUAL.    OF    CHEMISTRY 


IV.     LEAD   GROUP. 


LEAD. 


I 


Symbol  =  Pb  { Plumbum )  —  Atomic  weight  —  207  ( 0  —  16 :  206.9 ; 
n=l:2Q5M}— Molecular  weight— 414  {1)—Sp.  gr.^UAib—Fmes 
(d  325''  (en""  ¥,)— Name  from  loed=  heavy  (Sajrm), 

Lead  is  usually  classed  with  Cd,  Bi,  or  Cq  and  Hg.  It  difiPers, 
however,  from  Bi  in  being  bivalent  or  quadrivalent,  but  not  triva- 
lent,  and  in  forming  no  componnds  resembling  those  of  Ijismnthyl 
(BiO);  from  Cd,  in  the  nature  of  its  O  compounds;  and  from  Cu  and 
Jig  m  forming  no  compounds  similar  to  the  mereurous  and  cuprous 
salts.  Indeed,  the  nature  of  the  Pb  compounds  is  such  that  the 
element  is  best  classed  in  a  group  by  itself,  which  finds  a  place  io 
this  class  by  virtue  of  the  existence  of  potassium  plumbate. 

Occurrence.-=^Its  most  abundant  ore  is  galena,  PbS.  It  also 
occurs  in  white  lead  ore,  PbCOa,  in  anglesite,  PbS04»  and  in  horn 
lead,  PbCl2, 

Preparatton.—^alena  is  first  roasted  with  a  little  lime.  The  mix 
ture  of  PbO,  PbS,  and  PbSOi  obtained  is  strongly  heated  in  a  rever* 
beratory  furnace,  when  SO2  is  driven  off.  The  impure  work  lead,  so 
formed,  is  purified  by  fusion  in  air,  aud  removal  of  the  film  of  oxids 
of  Sn  and  Sb.  If  the  ore  be  rich  in  Ag,  that  metal  is  extracted,  by 
taking  advantage  of  the  greater  fusibility  of  an  alloy  of  Pb  and  Ag,  ^ 
than  of  Pb  alone;    and  subsequent  oxidation  of  the  remaining  Pb.       H 

PropertieSi — PhtfsicaL — ^It  is  a  bluish  white  metal;  brilliant  upon 
freshly  cut  surfaces 5  very  soft  and  pliable;  not  very  malleable  or 
ductile;  crystallizes  in  octahedra;  a  poor  conductor  of  electricity;  a 
better  conductor  of  heat.  When  expanded  by  heat  it  does  not,  on 
cooling,  return  to  its  original  volume. 

Chemical . — When  exposed  to  air  it  is  oxidized,  more  readily  and 
completely  at  high  temperatures.  The  action  of  H^jO  on  Pb  varies 
with  the  conditions.  Pure  nnaii^rated  Hl»0  has  no  action  upon  it.  By 
the  combined  action  of  air  and  moisture  Pb  is  oxidized,  and  the  oxid 
dissolved  in  the  HoO,  leaving  a  metallic  surface  for  the  continuance 
of  the  action.  The  solvent  action  of  H^jO  upon  Pb  is  increased,  owing 
to  the  formation  of  basic  salts,  by  the  presence  of  nitrogenized  organic 
substances,  nitrates,  nitrites,  and  chlorids.  On  the  other  hand,  car- 
bonates, sulfates,  and  phosphates»  by  their  tendency  to  form  insoluble 
coatings,  diminish  the  corroding  action  of  H2O.  Carbonic  acid  in 
small  quantity,  especially  in  presence  of  carbonates,  tends  to  preserve 
Pb  from  solution,  while  H2O  highly  charged  with  it  {soda  water) 
dissolves  the  metal  readily.     Lead  is  dissolved,  as  a  nitrate,  by  HNOa, 


I 


LEAD 


H2SO4,  when  cold  nm\  moderately  concentrated,  does  not  affect  it;  but, 
when  heated,  dissolves  it  the  more  readily  as  the  acid  is  more  concen- 
trated. It  is  attacked  by  HCI  of  sp,  g^r.  IA2,  especially  if  heated. 
Acetic  acid  dissolves  it  as  acetate,  or,  in  the  presence  of  CO2,  con- 
verts it  into  white  lead. 

Oxids* — Lead  Monoxid — Pro^jrM^Massicot— JLitharge — Plum- 
bi  oxidum  (U.  8.;  Br.) — PbO — 222.9^^is  prepared  hy  heating  Ph,  or 
its  carbonate,  or  nitrate,  in  air.  If  the  product  have  been  fused,  it  is 
litharge;  if  not,  massicot.  It  forms  copper -colored,  mica-like  plates, 
or  a  yellow  powder;  or  crystallizes,  from  its  sMlntiou  in  soda  or 
potash,  in  white,  rhombic  dodecahedra,  or  io  rose-eolorfid  enbes.  It 
foses  near  a  red  heat,  and  volatilizes  at  a  white  heat;  sp.  gr.  9,277- 
9.5.     It  is  sparingly  solubJe  in  H-jO,  forming  an  alkaline  solution. 

Heated  in  air  to  3(X)°  {572°  FJ  it  is  oxidized  to  minium.  It  is 
readily  reduced  by  II  or  C.  With  CI  it  forms  PbCl^  and  O.  It  is  a 
strong  base;  decomposes  alkaline  salts,  with  liberation  of  the  alkali. 
It  dissolves  in  HNO3,  and  in  hot  acetic  acid,  as  nitrate  or  acetate. 
When  ground  up  with  oils  it  saponifies  the  glycerol  ethers,  the  Pb 
combining  with  the  fat^y  acids  to  form  Pb  soaps,  one  of  which,  lead 
oleatCf  is  the  emplastruni  plombi  (U.  S.;  Br.).  It  also  combines 
with  the  alkalies  ami  earths  to  form  plumbites.  Calcium  plumbite» 
CaPi>203,  is  a  crystalline  sail,  formed  by  heating  PbO  with  milk  of 
lime,  and  used  in  solution  as  f  hair  dye. 

Plumboso-plumbic  Oxid — RM  oj^id — Minium — Red  lead— PbitOi 
— 6S4.7 — is  prf*pared  Ijy  heating  massicot  to  BU)""  (572^  FJ  in  air. 
It  ordinarily  has  the  composition  Pb:(04,  and  has  been  ctmsidered  as 
composed  of  Pb02,  2PbO;  or  as  a  basic  lead  salt  of  plnnibic  acid, 
HOjPb,  PbO.  An  orange -colored  variety  is  formed  when  lead  ear- 
W:nte  is  heateil  to  300^  (572*'  FJ. 

It  is  a  bright  red  powder,  sp.  gr.  8.62,  It  is  converted  into  PbO 
*lieu  strongly  heated,  or  by  the  action  of  reducing  agents.  HXO3 
<!t"»>gie8  its  color  to  brown,  dissolving  PbO  and  leaving  PbO:>.  It  is 
decomposed  by  HCI,  with  formation  of  PbCis,  H2O  and  CI. 

I-cad  Dioxid. — Peroxide  or  puce  oxklf  or  brown  ond^  or  hlnoxid  of 
i^nd-^plfi^^jjic  awAi^r/m/— Pb02^238.9'— is  prepared,  either  by  dis- 
Mviug  the  PbO  out  of  red  lead  by  dilute  HNOj,  or  by  passing  a 
canr^nt  of  CI  through  H-iO,  holding  lead  carbonate  in  suspension. 

Il  i«  a  dark,  reddish  brown,  amorphous  powder;  sp.  gr.  8,903- 
f-^^;  insoluble  in  H-iO.  Heated,  it  loses  half  its  O,  and  is  converted 
^^^'^  PbO.  It  is  a  valuable  oxidant.  It  absorbs  SO-j  to  form  FbSOi. 
^f  ''ombines  with  alkalies  to  form  plumbates,  Mi*PbO,i. 

Plumbic  Acid. — H^PbOa — 256.9 — forms  crystalline  plates,  at  the 
T'^'lectrode,  when  alkaline  solutions  of  the  Pb  salts  are  decomposed 
"y  ft  Weak  current. 


206  MANUAL    OF    CHEMISTRY 

Lead  Sulf id— Galena — PbS — 238.9 — exists  in  nature.  It  is  also 
formed  by  direct  union  of  Pb  and  S;  by  heating  PbO  with  S,  or 
vapor  of  CS2;  or  by  decomposing  a  solution  of  a  Pb  salt  by  H2S  or 
an  alkaline  sulfid. 

The  native  sulfid  is  a  bluish  gray,  and  has  a  metallic  luster;  sp.  gr. 
7.58;  that  formed  by  precipitation  is  a  black  powder;  sp.  gr.  6.924. 
It  fuses  at  a  red  heat  and  is  partly  sublimed,  partly  converted  into  a 
subsulfate.  Heated  in  air  it  is  converted  into  PbSO^,  PbO  and  SO2. 
Heated  in  H  it  is  reduced.  Hot  HNO3  oxidizes  it  to  PbSOi.  Hot  HCl 
converts  it  into  PbCh.    Boiling  H2SO4  converts  it  into  PbSOi  and  SO2. 

Lead  Chlorid— PbCl2 — 277.9— is  formed  by  the  action  of  CI  upon 
Pb  at  a  red  heat;  by  the  action  of  boiling  HCl  upon  Pb,  and  by 
double  decomposition  between  a  lead  salt  and  a  chlorid. 

It  crystallizes  in  plates,  or  hexagonal  needles  ;  sparingly  soluble 
in  cold  H2O,  less  soluble  in  H2O  containing  HCl;  more  soluble  in  hot 
H2O,  and  in  concentrated  HCl. 

Several  oxychlorids  are  known.  Cassel,  Paris,  Verona,  or 
Turner's  yellow  is  PbCk,  7PbO. 

Lead  lodid— Plumbi  iodidum  (U.  S.;  Br.)— Pblg— 460.09— is 
deposited,  as  a  bright  yellow  powder,  when  a  solution  of  potassium 
iodid  is  added  to  a  solution  of  Pb  salt.  Fused  in  air,  it  is  converted 
into  an  oxyiodid.  Light  and  moisture  decompose  it,  with  liberation 
of  I.  It  is  almost  insoluble  in  H2O,  soluble  in  solutions  of  ammo- 
nium  chlorid,  sodium  hyposulfite,  alkaline  iodids,  and  potash. 

Salts  of  Lead. — Nitrates.— Lead  Nitrate — Plumbi  nitras  (U.  S.; 
Br.)— Pb(N03)2— 330.9— is  formed  by  solution  of  Pb,  or  of  its  oxids, 
in  excess  of  HNO3.  It  forms  anhydrous  crystals  ;  soluble  in  H2O. 
Heated,  it  is  decomposed  into  PbO,  0  and  NO2. 

Besides  the  neutral  nitrate,  basic  lead  nitrates  are  known,  which 
seem  to  indicate  the  existence  of  nitrogen  acids  similar  to  those  of 
phosphorus;  Pb3(NO.i)2 — orthonitrate ;  and  Pb2N207 — pjrronitrate. 

Lead  Sulfate— PbS04- 302.9— is  formed  by  the  action  of  hot, 
concentrated  H2SO4  on  Pb;  or  by  double  decomposition  between  a 
sulfate  and  a  Pb  salt  in  solution.  It  is  a  white  powder,  almost  insol- 
uble in  H2O,  soluble  *in  concentrated  H2SO4,  from  which  it  is  de- 
posited by  dilution. 

Lead  Chromate — Chrome  yellow— PbCr04— 323.3— is  formed  by 
deeomposiner  Pb(N03)2  with  potassium  chromate.  It  is  a  yellow, 
amorphous  powder,  insoluble  iu  H2O,  soluble  in  alkalies. 

Acetates. — Neutral  Lead  Acetate — Salt  of  Saturn — Sugar  of 
Lead— Plumbi  acetas  (U.  S.;  Br.)— Pb(C2H302)2+3Aq— 324.9+54- 
— is  formed  by  dissolving  PbO  in  acetic  acid;  or  by  exposing  Pb  in 
oontaot  with  acetic  acid  to  air. 

It  crystallizes  in  large,  oblique  rhombic  prisms,  sweetish,  with  a 


LEAD 


'207 


metallic  after-taste;  soluble  in  H2O  aud  alcohol;  its  solutions  being 
acid.  Id  air  it  effloresces,  aud  is  superficially  converted  into  car- 
bonate. It  fuses  at  75. r>^'  (167.9*^'  F  J ;  loses  Aq  and  a  part  of  its 
acid  at  lOO*^  (212*^  FJ,  fonninpr  the  sesquibasie  acetate,  2[Pb- 
(C2H302)JPb(OH)2;  at  280*"  (536*^  F.)  it  enters  into  true  fosion, 
and,  at  a  sligbtly  higher  temperature,  is  decomposed  into  CO2;  Pb, 
and  acetone.  Its  aqueous  solution  dissolves  PbO,  with  formation  of 
basic  acetates. 

Scxbasic  Lead  Acetate— Pb(C2H302) OH,  2PbO— 728.7— is  tha 
main  constituent  of  Goulard's  extract=Liq.  plumbi  subacetatis  {U. 
8,;  Br.),  and  is  formed  by  boiling  a  solution  of  the  neutral  ncetate 
with  PbO  in  fine  powder.  The  solution  becomes  milky  on  addition 
of  ordinary  H^f),  from  formation  of  the  sulfate  and  carbonate. 

Lead  Carbonate — PbCOa — 266.9 — occtirs  in  nature  as  cerusite; 
and  is  formed,  as  a  white,  insoluble  powder,  when  a  solution  of  a  Pb 
compound  is  decomposed  !>y  an  alkaline  carbonate,  or  by  passing  CO2 
_tiirough  a  solution  contain intj  Pb. 

The  plumbi  carbonas  {U.  S.;  Br.),  or  white  lead  or  ceruse,  is  a 
sic  carbonate  (PbCOrs)^,  PbH^Os — 774.7 — mixed  with  varyiijt^  pro- 
portions of  other  basic  carbonates.  It  is  usually  prepared  by  the 
action  of  CO2  on  a  solution  of  the  snbacetate,  prepared  In"  the  action 
of  acetic  acid  on  Pb  and  PbO*  It  is  a  heavy,  white  powder,  iTisolublc 
in  H2O,  except  in  the  presence  of  CO2;  soluble  in  acids  with  effer* 
veseence;  and  decomposed  by  heat  into  CO2  and  PbO.  White  lead 
enters  into  the  composition  of  almost  all  oil-paints,  being  used  to 
dilate  other  pigments.  The  darkening  of  oil-paintings  is  dne  to  the 
formation  of  the  black  lead  snlfid  l>y  atmospheric  H^S. 

Analytical  Characters*— (1)  Hydrogen  snlfid,  in  acid  solution:  a 
!daek  ppt,;  insoluble  in  alkaline  sulfids,  and  in  cold,  dilute  acids. 
(2)  Ammonium  sulfhydrate  :  blark  ppt.;  insoluble  in  excess.  (3) 
Hydrochloric  acid:  white  ppt.,  in  not  too  dilute  solution;  soluble  in 
boiling  H2O.  (4)  Ammonium  hydroxid  :  white  ppt.;  insoluble  in 
excesa.  (5)  Potash:  white  ppt.;  soluble  in  excess,  especially  when 
beated.  (6)  Sulfuric  acid:  white  ppt.;  insoluble  in  weak  acids,  sol- 
uble in  solution  of  ammonium  tartrate,  (7)  Potassium  iodid:  yel- 
low ppt.;  sparingly  sohihle  in  boiling  H2O;  soluble  in  large  excess. 
(8)  Potassium  cbromate  :  yellow  ppt. ;  soluble  in  KHO  solution. 
(f>)   Iron  or  zinc  separate  the  element  from  solution  of  its  salt«. 

Action  on  the  Economy. — All  the  soluble  compounds  of  Pb,  and 
those  which,  although  not  soluble,  are  readily  convertible  into  soluble 
^compounds  by  H2O,  air,  or  the  digestive  fluids,  are  actively  poi- 
fHifions.  Some  are  also  injurious  by  their  local  action  upon  tissues 
with  which  they  come  in  contact;  such  are  the  acetate,  and,  in  less 
decree*  the  nitrate* 


MANUAL    OF    CHEMISTRY 


The  chronic  form  of  lead  intoxication,  painter's  colic,  etc., 
purely  poisonous,  and  is  produced  by  tlie  continued  absorption  of 
rainute  quantities  of  Pb,  either  by  the  skin,  lungs,  or  stoinaeh.  The 
acute  form  presents  symptoms  referable  to  the  local,  as  well  as  to  the 
poisonous,  action  of  the  Pb  salt,  and  is  usually  caused  by  the  inges- 
tioo  of  a  single  dose  of  the  acetate  or  carbonate. 

Metallic  Pb,  although  probably  not  poisonous  of  itself^  causes 
chronic  lead -poisoning  by  the  readiness  with  which  it  is  convertible 
into  cdmpounds  capable  of  absorption.  The  principal  sources  of 
poisoning  by  metallic  Pb  are:  the  contamination  of  drinking  water 
which  has  been  in  contact  with  the  metal  (see  p.  119);  the  use  of 
articles  of  food,  or  of  chewing  tobacco,  which  has  been  packed  in  tin- 
foil, containing  an  excess  of  Fb;  the  drinking  €»f  beer  or  other  bev- 
erages whirh  have  been  in  contact  with  pewter;  or  the  handling  of 
the  metal  and  its  alloys. 

Almost  all  the  compounds  of  Pb  may  produce  painter's  colic. 
The  carbonate,  in  painters,  artists,  manufacturers  of  white  lead,  and 
in  persons  sleeping  in  newly- painted  rooms j  the  oxids,  in  the  manu* 
factures  of  glass,  pottery,  sealing-wax,  and  litharge,  and  by  the  use 
of  lead -glazed  pottery;  by  other  compounds,  by  the  iulialation  of  the 
dust  of  cloth  factories,  and  by  the  use  of  lead  hair- dyes. 

Acute  lead* poisoning  is  of  by  no  means  as  common  occurrence  as 
the  chronic  form,  and  usually  terminates  in  recovery.  It  is  caused 
by  the  ingestion  of  a  single  large  dose  of  the  acetate,  snbacetate,  car- 
bonate, or  of  red  lead.  In  such  cases  the  administration  of  mag- 
nesium sulfate  is  intlicateJ;  it  enters  into  double  decomposition  with 
Pb  salt  to  form  the  insoluble  PbSOi. 

Lead,  once  absorbed,  is  eliminated  very  slowly,  it  becoming  fixed 
by  combination  with  the  proteins,  a  form  of  combination  which  is 
rendered  soluble  by  potassium  iodiiL  The  channels  of  elimination 
are  by  the  perspiration,  urine  and  bile. 

In  the  analysis  for  mineral  poisons  the  major  part  of  the  Pb 
is  precipitated  as  PbS  in  the  treatment  by  ITsS.  The  PbS  remains  _ 
upon  the  filter  after  extraction  with  ammonium  sulfhydrate.  It  ■ 
is  treated  with  warm  HCl,  which  decolorizes  it  by  transforming 
the  sulfid  into  chlorid.  The  PbC)2  thus  formed  is  dissolved  in  hot 
H2O,  from  which  it  crystallizes  on  cooling.  The  solution  still  con- 
tains PbClL-  in  sufficient  quantity  to  respond  to  the  tests  for  the 
metal. 

Although  Pb  is  not  a  normal  constituent  of  the  body,  the  every- 
day methods  by  which  it  may  be  introduced  into  the  economy,  and 
the  slowness  of  its  elimination,  are  such  as  to  render  the  greatest 
caution  necessary  in  drawing  conclusions  from  the  detection  of  Pb  in 
the  body  after  death. 


I 


I 
I 


BTSMFTH 


209 


V,    BISMUTH   GROUP. 


BISMUTH. 


Spmbol=Bi—Atmnk  wpight=20S.u  {0=16:208.5;  H==l:206.8)— 
Mohcuhtr  w€ight=420  (!)  —Sp,  ijt\=9.fjll-^.dS5— Fuses  at  268"* 
(514.4^  FJ. 

This  element  is  usually  classed  with  Sb;  by  some  writers  amoDg 

the  metals,  by  others  in  the  phosphorits  group.     We  are  led  to  class 

Bi  iu  our  third  class,  and  in  a  group  akme,  because:   (1)  while  the 

so-called  salts  of  Sb  are  not  salts  of  the  element,  but  of  the  radical 

(S1»0)',  antimony},  Bi  enters  into  saline  combination,  not  only  iu  the 

radical  bismuthyl  (BiO)',  but  also  as  an  element;   (2)  while  the  com- 

ponuds  of  the  elements  of  the  N  group  in  which  those  elements  are 

quinquivalent  are,  as  a  rule,  more  stable  than  those  in  which  they  are 

trivaleut,   Bi  is  trivalent  in  all  its  known  conipounds  except  one, 

which  is  very  unstable,  in  which  it  is  quinquivalent;   (3)  the  hydrates 

of  the  N  group  are  strongly  acid,  and  their  etvrresponding  salts  are 

stable  and  well  defined;  but  those  hydrates  of  Bi  which  are  acid  are 

Imt  feebly  so,  and  the  bismuthates  are  unstable;   (4)  no  compound  of 

Biand  TI  is  known. 

Occurrence. — Oecui's  principally  free,  also  as  Bi^Oa  and  BisSj, 
Properties. — Crystallizes  in  brilliant,  mettdlic  rhombohedra;  hard 
and  brittle. 

It  ia  only  superficially  oxidized  in  cold  air.  Heated  to  redness  in 
«ir,  it  becomes  coated  with  a  yclhuv  film  of  osid.  In  H2O,  containing 
^'Oj,  it  forms  a  crystalline  subcarbcuiate.  It  combines  directly  with 
^X  Br  and  I.  It  dissolves  in  hot  H2SO4  as  sulfate,  and  iu  HNO3  as 
ttitmte. 

It  is  usually  contaminated  with  As,  fnnn  which  it  is  host  purified 
^  heating  to  redness  a  mixture  of  powdered  bismuth,  potassium 
carbonate,  soap  and  charcoal,  under  a  layer  of  charcoal.  After  an 
^^tir  the  mass  is  cooled;  the  button  is  separated  and  fused  until  its 
*Qrfaee  begins  to  be  coated  with  a  yellowish  brown  oxid. 

Oxids* — Four  oxids  are  known;   Bi-202,  Bi^Oj,  Bi204,  and  BiaOs. 

Bismuth  Trioxid  —  Binm  a  f  hons  oj-itl  —  Protoxid  —  B bOa — 465 — is 
fenn^d  by  heatitjg  Bi.  or  its  nitrate,  carbonate  or  hydrate.  It  is  a 
N<*  yellow,  insoluble  powder;  sp.  gr,  8,2;  fuses  at  a  nr'd  heat;  solublo 
i^  HCl  HNO.T  and  II-jSO^  and  in  fused  potash. 

Hydrates, — Bismuth  forms  at  least  four  hydrates. 

Bismuthous  Hydroxid — Bill303 — 259.5 — is  formed,  as  a  white 
pr^ipitata,  when  potash  or  ammonium  hydroxid  is  added  to  a  cold 


210 


MANUAL    OF    CHEMISTKY 


solution  of  a  Bi  salt.     When  dried  it  loses  H2O,  and  is  converted  into 
Bismuthyl  hydroxid  (BiO)HO. 

Bismuthic  acid — (BiO^IHO — 257*5 — is  deposited,  as  a  red  pow- 
der, wbiiii  CI  is  passed  through  a  boiling  solution  of  potash,  Liokliog 
bismuthous  hydroxid  in  suspeusion.  When  heated  it  is  eon  verted 
into  the  pentoxid,  BisO^. 

Pyro bismuthic  Aeid — H^Bj-jOt — 533 — is  a  dark  brown  powdef, 
preeipitated  tnym  sohition  of  bisroiUh  nitrate  by  potassium  uyaiiid. 

Bismuth  Trichlorid^ — lihnitithons chloritl — ^BiCJa — 314.9^ — ^is  formed 
by  heating  Bi  in  CI;  by  distilling  a  mixture  of  Bi  and  inereuric 
chlorid;  or  by  distilling  a  solution  of  Bi  in  aqua  regia.  It  is  a  fus- 
ible, volatile,  deliquescent  solid;  soluble  in  dihite  HCL  On  eootaet 
with  HjO  it  is  deeomposed  with  fonnatiou  of  bismuthyl  chlorid, 
(BiO)Cl,  or  pearl  white. 

Bismuth  Nitrate— BiCNOs) a+ 5  Aq— 394.5+90— obtained  by  dis- 
solving Bi  in  IINO3.  It  crystallizes  in  large,  colorless  prisms;  at 
150°  (302°  FJ,  or  by  contact  witli  H2O,  it  is  converted  into  bis- 
muthyl nitrate;   nt  260''  (500''  FJ  into  Bi203. 

Bismuthyl  NittBle—Tnsiutntte  or  HHhitilmie  of  bumuth — Fiake 
whUe—Bismuthi  subnitras— (U.  S.;  Br.)  — (BiO)N03HiO— 304.5— 
is  formed  by  deeomposing  a  sohition  of  Bi(N0a)3  with  a  large  quantity 
t*f  H2O.  It  is  a  white,  hea%^y,  faintly  acid  powder;  soluble  to  a 
nlight  extent  in  H2O  when  freshly  precipitated,  the  solution  depositing 
it  again  on  standing.  It  is  decomposed  by  pure  H2O,  but  uot  by  H2O 
eontaining  -^  ammonium  nitrate.  It  usually  contains  1  Aq.  which 
it  loses  at  100°  (212^  FJ  Bismuth  subuitrate,  as  well  as  the  sub- 
carbonate,  is  liable  to  contaminatiou  with  ai'senie^  which  accompanies 
bismuth  in  its  ores.  1 

Bismuthyl  Carbonate^ — Bismuth  subc€irbonate — ^  Bismuthi  sub- 
carbonas  (U.  S.)  Bismuthi  carbonas  (Br.)  — (BiO^CCbHiO  —  527 
^-is  a  white  or  yellowish,  amorphous  i>owder,  formed  when  a  solution 
of  an  alkaline  carbonate  is  added  to  a  solution  of  Bi(XOa)a.  It  is 
odorless,  tasteless,  and  insoluble  hi  HjO  and  in  alcohol. 

When  heated  to  100°  (212°  FJ,  it  loses  II2O,  and  is  converted 
into  (BiO}>C03.  At  a  higher  temperature  it  is  further  decomposed 
into  Bi'iOa  and  CO2. 

Analytical  Characters. — (!)  Water:  white  ppt*,even  in  presence 
of  tartaric  aeid,  but  not  of  HNO,i,  HCl,  or  H2S04.  (2)  Hydrogen 
sulfide  black  ppt.,  insoluble  in  dilute  acids  and  in  alkaline  sulfide. 
(3)  Ammonium  sulfliydrate;  black  ppt.,  insoluble  in  excess.  (4) 
Potash  soda,  or  ammonia :  white  ppt,,  insoluble  in  excess^  and  in 
tartaric  acid;  turns  yellow  when  the  liquid  is  boiled,  (5)  Potassium 
ferroeyanid:  yellowish  ppt.,  insoluble  in  HCl.  (G)  Potassium  ferri* 
cyauid:    yeUowish   ppt«,   soluble   in   HCl.      (7)    Infusion  of   galls: 


1 


J 

,4 


TITANIUM    AND    ZIRCONIUM  211 

oraDge  ppt.  (8)  Potassinm  iodid:  brown  ppt.,  soluble  in  excess. 
(9)  Reacts  with  Beinsch's  test  (g.  v.),  but  gives  no  sublimate  in  the 
glass  tube. 

Action  on  the  Economy.— Although  the  medicinal  compounds  of 
bismuth  are  probably  poisonous,  if  taken  in  suf&cient  quantity,  the 
ill  effects  ascribed  to  them  are  in  most,  if  not  all  cases,  referable  to 
contamination  with  arsenic.  Symptoms  of  arsenical  poisoning  have 
been  frequently  observed  when  the  subnitrate  has  been  taken  inter- 
nally, and  also  when  it  has  been  used  as  a  cosmetic.  Bismuth  sub- 
nitrate  is  frequently  administered  by  physicians  in  cases  of  arsenical 
poisoning,  not  recognized  as  such  during  life. 

When  preparations  of  bismuth  are  administered,  the  alvine  dis- 
charges contain  bismuth  sulfid,  as  a  dark  brown  powder. 


VI.     TIN   GROUP. 

TITANIUM — ZIRCONIUM — TIN. 

Ti  and  Sn  are  bivalent  in  one  series  of  compounds,  SnCla,  and 
quadrivalent  in  another,  SnCU.  Zr,  so  far  as  known,  is  always 
quadrivalent.  Each  of  these  elements  forms  an  acid  (or  salts  corre- 
sponding to  one)  of  the  composition  of  H2MO3,  and  a  series  of  oxy- 
salteof  the  composition  of  M*^(N03)4. 

TITANIUM. 

8yfnbol=Ti — Atomic  weight=^S—8p.  gr,=5,3. 

Occurs  in  clays  and  iron  ores,  and  as  Ti02  in  several  minerals. 
Titanic  anhydrid,  TiOa,  is  a  white,  insoluble,  infusible  powder,  used 
in  the  manufacture  of  artificial  teeth;  dissolves  in  fused  KHO,  as 
potassium  titanate.  Titanium  combines  readily  with  N,  which  it 
absorbs  from  air  when  heated.  When  NH3  is  passed  over  red-hot 
TiOj,  it  is  decomposed  with  formation  of  the  violet  nitrid,  TiN2. 
Another  compound  of  Ti  and  N  forms  hard,  copper- colored,  cubical 
^^fystals. 

ZIRCONIUM. 

8yinbol=Zr — Atomic  weight=S9 — Sp,  flrr.=4.15. 

Oecnrs  in  zircon  and  hyacinth.  Its  oxid,  zirconia,  Zr02,  is  a 
^hit«  powder,  insoluble  in  KHO.  Being  infusible,  and  not  altered 
^7  exposure  to  air,  it  is  used  in  pencils  to  replace  lime  in  the  calcium 

light. 


MANUAL    OP    CHEMISTRY 

TIN. 

Sijmhol^Sn  iStannmn) —Atamic  weight  =  11S.5  (0=16:118.5; 
M=l:lll ,5b)— Molecular  umght=2'd5A  {1)—8p.  ^r. =7. 285-7.293— 

Fuses  at  22S°  (442.4°  FJ. 

Occurrence. — As  tinstone  (SHO2)  or  cassiterite,  and  in  stream 
tin. 

Preparation, — The  commercial  metal  is  prepared  by  ro  as  ting  the 
ore,  extracting  with  H2O,  redneiug  the  residue  by  healinj?  with  ohar- 
<5oal,  and  retining. 

Pure  tin  is  obtained  by  dissolving  the  metal  in  HClj  filtering; 
evaporating;  dissolving  the  residue  in  H2O:  decomposing  with  am- 
monium <*arbouate;   and  rediK^iug  the  oxid  with  ehareoaL 

Properties, — A  soft,  malleable,  bluish  white  metal;  bnt  slightly 
tenacious;  emits  a  peculiar  sound,  the  tin-cry,  when  bent.  A  good 
conductor  of  heat  and  electricity.  Air  affects  it  but  little,  except 
when  it  is  heated;  more  rapidly  if  Sn  be  allayed  with  Pb.  It  oxidizes 
slowly  iu  H*iO;  more  rapidly  in  the  preseuce  of  sodium  chlorid.  Its 
presence  with  Pb  accelerates  the  action  of  H2O  upon  the  latter.  It 
dissolves  in  HCl  as  SnCb.  In  presence  of  a  small  qnantitj*  of  H^O, 
HNO3  converts  it  into  metastannic  acid.  Alkaline  solutions  dissolve 
it  as  met  a  Stan  nates.     It  combines  directly  with  CI,  Br,  I,  S,  P  and  As. 

Tin  plates  are  thin  sheets  of  Fe,  coated  with  Sn.  Tin  foil  con* 
sists  of  thin  lamimB  of  Sn,  frequently  alloyed  with  Ph.  Copper  and 
iron  vessels  are  tinned  after  brightening,  by  contact  with  molten  Su. 
Pewter,  bronze,  bell  metal,  gun  metal,  britannia  metal,  speculnm 
metal,  type  metal,  solder,  and  fusible  metal,  contain  Sn. 

Oxids. —  Stannous  Oxtd^- Pro foxki  —  SnO  — KM. 5 — obtained  by 
heating  the  hydroxid  or  oxalate  without  contact  of  air.  It  is  a  white, 
amorphous  powder,  soluble  in  acids,  and  in  hot,  concentrated  solution 
of  potash »     It  absorbs  O  readily. 

Stannic  Oxid^ — Binoxtd  of  tin — SnOi, — 150,r> — occurs  usitive  m 
tinstone  or  cassUerUet  and  is  formed  wbf^n  Su  or  SnO  is  heated  in  air. 
It  is  used  as  a  polishing  material,  under  the  name  of  putty  powder. 

Hydrates. — -  Stannous  Hydroxid  —  SnH202 — 152.5  —  is  a  white 
precipitate,  formed  by  alkaline  hydroxids  and  carbonates  in  solutions 
of  SnCltj. 

Stannic  Acid — H^SnOg — 168.5 — is  formed  by  the  action  of  alka- 
line hydroxids  on  solutions  of  SnCU.  It  dissolves  in  solutions  of  the 
alkaline  hydroxids,  forming  stannates* 

Metastannic  Acid — HiSuaOn — TTO.rj^-is  a  white,  insoluble  pow- 
der, formed  by  acting  on  Sn  wnth  HNO3. 

Chlorids.  —  Stannous  Chlorid  —  ProtocMorid  —  Tin  crystals — 
SnCl2+2Aq— 189.4+36  — is  obtained  by  dissolving  Sn  in  HCl.     It 


TIN  213^ 

crystallizes  in  colorless  prisms;  soluble  in  a  small  quantity  of  H2OV 
decomposed  by  a  large  quantity,  unless  in  the  presence  of  free  HCl,. 
with  formation  of  an  oxychlorid.  Loses  its  Aq  at  100°  (212°  P.), 
In  air  it  is  transformed  into  stannic  chlorid  and  oxychlorid.  Oxidiz- 
ing and  chlorinating  agents  convert  it  into  SnCU.  It  is  a  strong 
reducing  agent. 

Stannic  Chlorid — Bichlorid — Liquid  of  Libavius — SnCU — 260.3 — 
is  formed  by  acting  on  Sn  or  SnCk  with  CI,  or  by  heating  Sn  in 
aqua  regia.  It  is  a  fuming,  yellowish  liquid;  sp.  gr.  2.28;  boils  at 
120°  (248°  F.). 

Analytical  Characters. — Stannous. — (1)  Potash  or  soda  :  whiter 
ppt.;  soluble  in  excess;  the  solution  deposits  Sn  when  boiled. 
(2)  Ammonium  hydroxid:  white  ppt;  insoluble  in  excess;  turns 
olire- brown  when  the  liquid  is  boiled.  (3)  Hydrogen  sulfid:  dark 
brown  ppt.;  soluble  in  KHO,  alkaline  sulfids,  and  hot  H2O.  (4) 
Mercuric  chlorid:  white  ppt.,  turning  gray  and  black.  (5)  Auric 
chlorid:  purple  or  brown  ppt.,  in  presence  of  small  quantities  of 
HXO3.     (6)  Zinc:  deposit  of  Sn. 

Stannic. — (1)  Potash  or  ammonia:  white  ppt.;  soluble  in  ex- 
cess. (2)  Hydrogen  sulfid:  yellow  ppt.;  soluble  in  alkalies,  alkaline 
sulfids,  and  hot  HCl.  (3)  Sodium  hyposulfite:  yellow  ppt.,  when 
heated. 

Vn.     PLATINUM   GROUP. 

PALLADIUM.      PLATINUM. 

Vin.     RHODIUM  GROUP. 

RHODIUM.      RUTHENIUM.      IRIDIUM 

The  elements  of  these  two  groups,  together  with  osmium,  are 
Qsoallj  classed  as  ** metals  of  the  platinum  ores."  They  all  form 
hydrates  (or  salts  representing  them)  having  acid  properties.  Os- 
tniom  has  been  removed,  because  the  relations  existing  between  its 
eomponnds,  and  those  of  molybdenum  and  tungsten,  are  much  closer 
than  those  which  they  exhibit  to  the  compounds  of  these  groups. 
The  separation  of  the  remaining  platinum  metals  into  two  groups  is 
based  upon  resemblances  in  the  composition  of  their  compounds,  as 
shown  in  the  following  table. 

CHLORIDS. 

PdCli PtCla  RhCl2 RuCb t 

PdCU PtCU  RUCI4 IpCU 

...... Rh2Clfl Ru2Cl(,    ....  Ir2Cl» 


214  MANUAL    OP    CHEMISTRY 

OXIDS. 

PdO PtO  RhO RuO IrO 

RhsOs EU2O3 ItjOj 

Pd02 Pt02  RhOj EuOa Ir02 

RhOa RUO3 IrOa 

RuOi 


PLATINUM. 

Syfnbol=Pt— Atomic  weight=19^.8  (0=16:194.8;  H=l:193.25) 
—Molecular  iceight=390  (1)—8p.  flrr.=21. 1-21.5. 

Occurrence. — Free  and  alloyed  with  Os,  Ir,  Pd,  Rh,  Ru,  Fe,  Pb, 
An,  Ag,  and  On. 

Properties. — The  compact  metal  has  a  silvery  luster;  softens  at 
a  white  heat;  may  be  welded;  fuses  with  difficulty;  highly  malleable, 
ductile  and  tenacious.  Spongy  platinum  is  a  grayish,  porous  mass, 
formed  by  heating  the  double  chlorid  of  Pt  and  NH4.  Platinum 
black  is  a  black  powder,  formed  by  dissolving  PtCk  in  solution  of 
potash,  and  heating  with  alcohol.  Both  platinum  black  and  platinum 
sponge  are  capable  of  condensing  large  quantities  of  gas,  and  act  as 
indirect  oxidants. 

Platinum  is  not  oxidized  by  air  or  O;  it  combines  directly  with  CI, 
P,  As,  Si,  S,  and  C;  is  not  attacked  by  acids,  except  aqua  regia,  in 
which  it  dissolves.  It  forms  fusible  alloys  when  heated  with  metals  or. 
reducible  metallic  oxids.  It  is  attacked  by  mixtures  liberating  CI, 
and  by  contact  with  heated  phosphates,  silicates,  bydroxids,  nitrates, 
or  carbonates  of  the  alkaline  metals. 

Platinic  Chlorid — Tetrachlorid  or  perchlorid  of  platinum — PtCU 
— 336.6 — When  Pt  is  dissolved  in  aqua  regia  and  the  solution  is 
evaporated,  red,  deliquescent  crystals  of  hydrochloroplatinic  acid, 
H2PtCle,  are  obtained.  These,  when  heated  in  chlorin,  yield  yellow, 
non- deliquescent  crystals  of  platinic  chlorid,  PtCU.  Hydrochloro- 
platinic acid  is  a  strong  dibasic  acid,  the  platinum  being  in  the  anion, 
which  forms  crystalline  chloroplatinates  with  the  alkaline  metals, 
NH4,  and  a  great  number  of  nitrogenous  organic  bases.  The  forma- 
tion of  the  K  and  NH4  salts  is  utilized  to  test  for  those  cations,  and 
the  formation  of  the  organic  compounds  is  resorted  to  for  the  identi- 
fication and  analysis  of  these  bases. 


UTHIUM  215 


CLASS  v.— BASYLOUS  ELEMENTS. 

Elements  whose  Oxids  unite  with  Water  to  form  Bases;  never  to  form  Acids. 

Which  form  Ozysalts. 

The  elements  of  this  class  are  essentiall}'  basic  and  electropositive. 
In  solutions  of  their  compoands  they  never  occur  in  an  anion,  simple 
or  compound,  but  always  constitute  simple  cations. 


I.     SODIUM   GROUP. 

Alkali  Metals. 

UTHIUM — SODIUM— POTASSIUM— RUBIDIUM — CESIUM — SILVER. 

Each  of  the  elements  of  this  group  forms  a  single  chlorid,  M'Cl, 
and  one  or  more  oxids,  the  most  stable  of  which  has  the  composition 
M'lO.  They  are,  therefore,  univalent.  Their  hydroxids,  M^'HO,  are 
more  or  less  alkaline  and  have  markedly  basic  characters.  Silver 
resembles  the  other  members  of  the  group  in  chemical  properties, 
although  it  does  not  in  physical  characters. 

The  name  "alkali,"  first  applied  to  "potash"  from  wood  ashes 
(p.  225)  is  now  used  to  designate  substances  which  are  strongly  basic, 
are  alkaline  in  reaction,  and  saponify  fats.  The  caustic  alkalies  are 
the  hydroxids  of  E  and  Na,  the  carbonated  alkalies  are  their  car- 
bonates.  Volatile  alkali  is  ammonium  hydroxid  or  carbonate. 

LITHIUM. 

8ymbol=U— Atomic  weig1ii=l  (0=16:7.03^  H=l:6.97)— JtfbZc- 
^hrwnghi=\A:  {1)—8p.  gr, =0.589— Fuses  at  180°  (356°  P.)— Dw- 
^tred  by  Arfvedsan  tn  1817 — Name  from  Xtd«o5=8tony. 

Occurrence. — Widely  distributed  in  small  quantity;  in  raanymin- 
^kand  iniiieral  waters;  in  the  ash  of  tobacco  and  other  plants;  in 
tte  milk  and  blood. 

Properties. — A  silver- white,  ductile,  volatile  metal;  the  lightest 
^^the  solid  elements;  burns  in  air  with  a  crimson  flame;  decomposes 
HjO  at  ordinary  temperatures,  without  igniting. 

Lithium  Chlorid. — LiCl — 43.5 — crystallizes  in  deliquescent,  regn- 
'^P  octahedra;   very  soluble  in  H2O  and  in  alcohol. 

Lithium  Bromid  —  Lithii  bromidum  —  (U.  8.) — LiBr— 87  — is 
Conned  by  decomposing  lithium  sulfate  with  potassium  bromid;  or  Vjy 
f^^^nrating  a  solution  of  HBr  with  lithium  carbonate.  It  crystallizes 
*^  very  deliquescent,  soluble  needles. 

Lithium  Carbonate — Lithii  carbonas  (U.  S.;  Br) — Li2C03 — 74 — . 


21 C 


MAKTAL     OF    CHEMISTRY 


is  a  white,  sparingly  soluble^  alkaline,  amorphous  powder      With 
uric  acid  it  forms  lithium  urate  (q.  v.). 

Analytical  Characters, —  (1)  Aiiiraouium  carbonates  white  ppt.  ia 
concentrated  solutions;  not  in  dilnte  solnttons,  or  in  presence  o" 
ainmoniacal  salts.  (2)  Sodium  phosphate;  white  ppt.  in  neutral  or 
alkaliut^  solution;  soluble  in  acids  and  in  solutions  of  ammoniacal 
salts.  {3)  It  cokirs  the  Bunsen  Hame  i-ed;  and  exhibits  a  spectrum 
of  two  Hues— A=6705  and  6102  (Pig.  14,  No.  4,  p.  35). 


I 


SODIUM, 

iSVmto?— Na  (Natrium)— Atomic  weight^23  (O=16:23.05p 
11=1  t22,Sl)— Molecular  iveighf^AH  {f}—Sp.  gr.=0ST2— Fuses  at\ 
95.6°  (204.1°  F,}— Boils  at  742°  {1368°  F,)— Discovered   by  Dav^,] 

Occurrence. — ^As  chlorid,  very  abundantly   and    widely    distrib- 
uted; also  as  carbonate,  nitrate,  sulfate,  borate,  etc.  fl 

Preparation.^ — By  heatiiit^  a  mixture  of   dry  sodium   carbonate," 
chalk,  and  charcoal  to  whiteness  in  iron  retorts.    It  is  now  manu- 
factured by  the  electrolysis  of  fused  NaHO. 

Properties* — A  silver -white  metal,  rapidly  tarnished,  and  coated 
with  a  yellow  film  in  air,    Waxy  at  ordinary  temperatures;   volatile 
at  a  white  heat,  forming  a  colorless  vapor,  which  bums  in  air  with  a^ 
yellow  flame.  V 

It  oxidizes  in  air,  and  is  usually  preserved  under  naphtha.  It  buras 
with  a  yellow  flame.  It  combines  directly  with  CI,  Br»  I,  S,  P,  As, 
Pb  and  Hn.  It  decomposes  water  with  evolution  of  hydrogen?  Na2+ 
2H20^2NaHO  +  H2.  Because  of  this  and  other  similar  reactions, 
metallic  'sodium »  either  as  such  or  in  the  diluted  form  of  sodium 
amalgam,  is  largely  used  to  effect  reductions, 

Oxids« — Two  oxids  are  known  :  Sodium  monoxid  —  Na20  —  a  ^ 
grayish  white  mass;  formed  when  Na  is  burnt  in  dry  air,  or  by  the  ™ 
action  of  Na  on  NaHO.  Sodium  dioxid^Na202— a  white  solid, 
formed  when  Na  is  heated  in  dry  air  to  200°  {392*^  Fj.  Sodium 
dioxid,  or  pcroxid,  is  now  manufactured  by  oxidizing  the  fused  metal 
in  dry  air  or  oxygen,  and  is  used  as  a  bleaching  and  oxidizing  agent. 
It  is  a  yellowish  white,  amorphous,  very  hygroscopic  powder.  If  the 
temperature  be  kept  low  it  dissolves  in  dilute  acidSj  forming  a  strong 
solution  of  hydrogen  peroxid:  Na202+2HCl=2NaCl+H202.  With 
water  it  produces  a  great  elevation  of  temperature  and  liberates 
nascent  oxygen;  2Na202+2H20  =  4NaHO+02.  With  magnesium 
sulfate  it  forms  magnesium  peroxid,  a  non-alkaline  oxydantr  Na202+ 
MgS04^Na2S04+Mg02. 


SODIUM 


2r 


Sodium  Hydroxid—Sodhtm  Jiffdraie—CBusiic  Soda— Soda  (F^S.) 
— Soda  caustica  (BrJ^-XallO— 40 — is  formed;  (1)  Wheo  IhJJ  is 
decomposed  by  Na;  (2)  by  decomposing  sodic  carbonate  by  caleinm 
lijrdroxid-  Na-COji-f  CaH2oWcOaCa+2NaHO  (soda  by  lime) ;  (3)  in 
the  same  manner  as  ia  (2),  using  barium  liydroxid  in  place  of  Ihne 
(soda  by  baryta).  It  frequently  contains  eousiderable  quantities  of 
As.  (4)  Caustic  soda  is  now  largely  manufactured  by  electrolytic 
dec^jiu posit  ion  of  NaCl.  Tbe  Castner  process  is  tbe  one  usually 
adopted.  In  it»  by  a  rocking  arrangement,  mercury,  as  tbe  cathode, 
first  takes  np  tbe  liberated  sodium,  and  is  then  brought  in  contact 
with  a  suitable  quantity  of  water.  The  reactions  are:  2NaCl^Na2+ 
n-2,  and  Na2+2H20=2NaHO+H2.     {See  CblorinJ 

It  is  an  opaque,  white,  fibrous,  brittle  solid;   fusible  below  red* 

nesg;  sp*  gr.  2*00;  very  soluble  in  H2O,  forming  strongly  alkaline 

and  caustic  solutions  (soda  lye  and  liq,  sodae).     When  exposed   to 

sir,  solid  or  in  solution,  it  absorbs  H^O  and  CO2,  and  is  converted 

into  carbonate.     Its  solutions  attack  glass. 

Sodiunn  Chlorid — Common  salt — Sea  salt — Table  salt — Sodii 
chloridum  (U.  S.;  Br,) — NaOt — 58,. r> — t*ccum  very  abundantly  in 
•lature,  deposited  in  the  solid  form  as  rock  salt;  in  solution  in  all 
DHtural  waters^  especially  in  sea  and  mineral  spring  waters;  iu  sus- 
pension in  the  atmosphere;  and  as  a  constituent  of  almost  all  animal 
aiid  vefjetable  tissues  and  fluids.  It  is  formed  in  an  infinilc  variety 
^f  chemical  reactions.  It  is  obtained  from  rock  salt,  or  from  the 
iter«  of  the  sea,  or  of  saline  springs;  and  is  the  source  from  which 
•IltfaeNa  compounds  are  usually  olitalned,  directly  or  indirectly, 

It  erj'stallizes  in  anhydrous,  white  cubes,  or  octahedra;  sp.  gr, 
-0T8;  fuses  at  a  red  heat,  and  crystallizes  on  cooling;  sensibly  vola- 
Meata  whit^  heat:  quite  soluble  iu  H2O.  the  solubility  varying  but 
'^'ightly  with  the  variations  of  tjemperature.  Dilute  solutions  yield 
^Iro^wt  pure  ice  on  freezing.  It  is  precipitated  from  concentrated 
^"luiioMs  by  HCL  It  is  insoluble  in  absolute  alcohol;  sparingly  sol- 
'">l<?in  dilate  spirit.  It  is  decomposed  by  HiSOt  with  fornmtion  of 
Hriaml  sodium  sulfate:   2NaCl+H2SOi=2HCl+Na2S04, 

Sodium  Bromid—  Sodii  bromidum  ( U.  8. ) —  NaBr  —  103  —  is 
'f^nijed  by  dissolving  Br  in  solution  of  KaHO  to  saturation;  evapo- 
f'tiug;  calcining  at  dull  redness;  redissolving,  Altering,  and  crystiil- 
liiirjg.  It  crystallizes  in  auh3'drous  cubes;  quite  soluble  in  H2O, 
^'oble  in  alcohol. 

Sodium  lodid — Sodii  iodidum  (U.  8 J — Nal — 150 — is  prepared 
4  lii^ting  together  H2O,  Fe,  and  I  in  flue  powder;  filtering;  addling 
in  ^'qaivalent  quantity  of  sodium  sulfate,  and  some  slacked  lime, 
Ming,  Jecanting  and  evaporating.  Crystallizes  in  anhydrous  cubes; 
^^  soluble  in  H2O;   soluble  in  alcohol. 


^18 


MANUAL    OF    CHEMISTEY 


Sodium  Nitrate — Cubic  or  Chili  saltpeter — Sodii  nitras  (U,  S.) ; 
Sodee  nitras  (BrJ^NaN03^85— oeciirs  In  natuml  deposits  in  Chili 
and  Pern.  It  <'r>!stallizes  in  anhydrous,  deiiquesceut  rhombohedra; 
coolin's'  and  somewhat  bitter  in  taste;  fuses  at  310*^  (590°  P.);  very 
soluble  in  H2U.  Heated  with  H2SO4,  it  is  decomposed,  yielding 
HNOj  and  hydrosodic  sulfate:  H2S04'fNaN03=aNaS04-hHNOH. 
This  reaction  is  that  used  for  obtaiiiiiifir  HNOa. 

Sulfates,^Monosodic  Sulfate — HtjdroHodic  sulfate — Acid  ^^odiitm 
^itifate — Bistilfate  —  HNaSO* — ^120 — crystalliKes  lu  loii^,  four-sided 
prisms;  is  unstable  and  decoiuposed  by  air,  H-iO  or  alcohol,  into 
H2SO4  and  Na2S04«  Heated  to  dnll  redness  it  is  converted  into  so- 
dium pyrosulfatc,  Na^jS-jO?,  corresponding  to  Nordhausen  sulfuric 
acid. 

Disodic  Sulfate — Sodk  sulfate — Nettiral  sffdium  sulfate — Glauber's 
salt— Sodii  sulfas  {U.  S.);  sodae  sulfas  (Br.)— NaaSO^+^Aq— 142 
+  n  18 — ^occurs  in  nature  in  solid  deposits,  and  in  solution  in  natural 
waters.  It  is  obtained  as  a  secondary  product  in  the  manufacture  of 
HCl,  by  the  action  of  H2SO4  on  NaCl,  the  decomposition  occurring 
according  to  the  equation:  2NaCI+H2S04==^Nai>804+2  HCl,  if  the 
temperature  be  raised  sufficiently.  At  lower  temperatures,  the  mono- 
sod  ic  salt  is  produced,  with  only  half  the  yield  of  HCI:  NaClH- 
H2S04=NaHS04+HCL 

It  crystallizes  with  7  Aq,  from  saturated  or  supersaturated  solu- 
tions at  5°  (41°  FJ;  or,  more  usually,  with  10  Aq»  As  usually  met 
with  it  is  in  large,  colorless,  oblique,  rhombic  prisms  with  10  Aq; 
which  effloresce  in  air,  and  gradually  lose  all  their  Aq.  It  fuses  at 
33°  (9L4°  FJ  in  its  Aq,  which  it  gradually  loses.  If  fused  at  SS"" 
(91.4°  F.),  and  allowed  to  cool,  it  remains  Hquid  in  supermturated 
solution,  from  which  it  is  deposited,  the  entire  mass  becoming  solid, 
on  contact  with  a  small  particle  of  solid  matter.  It  dissolves  in  HCl 
with  considerable  diminution  of  temperature, 

Sodium  Sulfite— Sodii  sulfis  (U.  SJ— NaaSOaH- 7  Aq  — 126+ 
126^ — is  formed  by  passing  8O2  o%'er  crystallized  NaaCOa.  It  crj'stab 
lizes  in  efflorescent,  oblique  prisu)s;  quite  soluble  in  H2O,  forming  an 
alkaline  solution.     It  acts  as  a  reducing  agent. 

Sodium  Thiosulfate — SodiHm  kifpfmiljite — Sodii  hyposulfis  (U. 
S.) — NajSaOa+S  Aq — 158+90  —  is  obtained  by  dissolving  S  in  hot 
concentrated  solution  of  Na^SOri,  and  crystallizing. 

It  forms  large,  colorless,  efflorescent  prisms;  fuses  at  45°  (113° 
F  J ;  very  soluble  in  H2O,  insoluble  in  alcohol.  Its  solutions  pre- 
cipitate alumina  from  solutions  of  Al  salts,  without  precipitating  Fe 
or  Mn;  they  dissolve  many  compounds  insoluble  in  H^O;  cuprous 
hydroxid,  iodids  of  Pb,  Ag  and  Hg,  sulfids  of  Ca  and  Pb.  It  acts  as 
a  disinfectant  and  antiseptic.     H2SO4  decomposes  Na^SaOs  according 


■ 


BODITTM 


no 


totheeqtiatioD:  Na..S,0^i+HL^804=Na2S04+S02+S+HaO;  and  most 
other  acids  behave  similarly.  Oxalic,  and  a  few  other  acids »  decom- 
pose the  thiosulfate  with  tormaticm  of  H^S  as  well  as  SO2  and  8. 

Silicates. — Quite  a  number  of  silicates  of  Na  ai'c  known.  If  siVum 
and  Na-iCOa  be  fused  togetlier,  the  residue  extracted  with  H-iO,  and 
the  solution  evaporated,  a  trauspareut,  glass -like  mass,  soluble  in 
warm  water»  remains;  this  is  soluble  glass  or  water  glass.  Exposed 
to  air  in  contact  with  stone,  it  becomes  insoluble^  and  forms  an  iui- 
f>ei*raeable  coating. 

Phosphates. —  Trisodic  Phosphate — Bftsir  stxihim  phosphaif — 
Na3p04+12  Aq— 164+21(i— is  obtained  by  adding  NallO  to  disodic 
phosphate  solution,  and  crystallizing.  It  forms  six-sided  prisms; 
qaite  soluble  in  H2O.  Its  solntiou  is  alkaline^  and.  on  exposure  to 
air,  absorbs  CO-j,  with  formation  of  HNa^FO*  and  Naai'O.j. 

Disodic  Phosphsite^^ Hydt^o-tlisodic  phosphaie—Nfuiral  smlhim 
phosphite — Phosphate  of  soda — Sodii  phosphas  (U,  SJ;  sodae  phos- 
phas  (Br.) — IINa2P04+r2  Aq — 142  +  216 — is  obtainefl  by  couvertiug 
tricaleic  phosphate  into  monocalcic  phosphate,  and  decomposing  that 
salt  with  sodium  carlinnate:  Ca(PO,H,),+2Na2CO:«=CaCO.i+II,0  + 
€O2+2HNa2P04. 

Below  30°  (86"^  F.)  it  crystallizes  in  obliqne  rhombic  prisms,  with 
12  Aq;  at  33°  (91.4''  F.)  it  crystallizes  with  7  Aq.  The  salt  with 
12  Aq  effloresces  iu  air,  and  parts  with  o  Aq;  and  is  very  solnble  iu 
HiO.  The  salt  with  7  Aq  is  not  effloi-escent,  and  less  soluble  iu  H2O. 
Its  solutions  are  faintly  alkaline. 

Monosodic  Phosphate  ^ArrVi  sodium  phosphate  —  n2NaP04  + 
Aq — 120+18 — erystallizcs  iu  rhombic  prisms;  forming  acid  solntions. 
At  100'-  (212°  FJ  it  loses  Aq;  at  2iJ(f  (392°  F.)  it  is  eon  verted  into 
acid  pyrophosphate,  Na^ILjP.O:;  and  at  204°  (399,2°  F.)  into  the 
metaphosphate,  NaPO:i. 

Sodiunn  Arsenites.— The  disodie  arsenite,  NasHAsOa,  is  obtained 
»s  a  vis«.*ons  mass  by  fnsiug  together  1  molectnle  of  AS2O3  and  2  mole- 
cuIp^  of  Na-jOOa  without  contact  of  air.  The  mouosodie  arsenite, 
NaH^AsOa,  is  fornu'd  wlien  an  aqueous  snlution  of  Na:!C03  is  boiled 
with  As'iOu.  By  prcilun^rcl  Ijoiling  this  U  converted  into  the  pyro- 
ur^eiiite,  Na2H:iAs:<Oii»  and  tliis  into  the  metarsenite,  NaAs02,  by 
I>rftg!*e8sive  loss  of  water,  Sudium  arsenites  exist  in  embalniiug 
liquids  and  an^  used  in  dyeing. 

Sodium  Arsenates* — The  tLree  arsenates,  NaHiAsOj,  Na-jHAsO* 
and  NaaAsOi  corresponding  to  the  phosphates,  are  known,  and  are 
Ii9ed  iu  dyeing  processes, 

Disodic  Tefaraborate  —  Sodium  pyroborate  — Borate  of  sodium  — 
Borax— T*Var— Sodii  boras  (U.SJ;  Borax  (BrJ— NaaBiOr+lO  Aq 
— 202+180 — is  prepared  by  boiling  boric  acid  with  NavCOa  and  cr>'8- 


220 


MANITAL    OF    CHEMISTRY 


taltiziDg,  It  crj'stallizes  in  hexagonal  prisms  with  10  Aq;  permanent*^ 
io  moist  air,  but  efflorescent  in  dry  air;  or  in  re^ilar  oetahedra  with 
5  Aq,  permanent  in  dry  air.  Either  form^  when  heated,  fuses  in  ita. 
Aq,  swells  considerably;  at  a  red  heat  becomes  anhydrous;  and,  on 
coolino:^  leaves  a  transparent,  g^lass-Hke  mass.  When  fused  it  is 
eapable  of  dissolving  Tiiany  metallic  oxids,  forniiug  variously  colored 
masses,  henee  its  nse  as  a  flux  and  in  blow -pipe  analysis. 

Sodium  Hypochlorite — NaClO — 74.5 — only  kuowu  in  sohitiou— 
Liq.  sodae  chloratse  ( l\  S, ;  Br.)  or  Labarraque's  solution — ob- 
taiued  by  deeoniposing  a  solution  of  eblorid  of  lime  by  Nu:;COj.  It 
it  a  valuable  souree  of  CU  and  is  used  as  a  bleaehitig  aud  disinfecting 
iifjeut. 

Sodium  Chlorate  — Sodii  chloras  (U.  8J— NaClO.i  —  100.(>^is 
laannfactured  iudustrialiy  by  treating  milk  of  lime  with  CI.  The 
solution  of  i-aleinm  ehlorid  and  chlorate  so  obtained  is  treated  with 
Na^SOi,  after  removal  of  part  of  tbe  CaClj  by  eoucentration  and 
cooling  to  12°  idS.G''  ¥.).  The  NaClOa  and  NaCl  formed  are  sepa- 
rated by  taking  advantage  of  the  gi*eater  solubility  of  the  former. 
NaClOy  is  soluble  in  its  own  weight  of  Hi»0  at  20""  (68°  F.), 

Sodium  Manganat€—Na2Mu04 +10  Aq— 164  +  180 — faintly  col- 
ored crystals,  forming  a  green  solution  with  H^O — Condy*s  green 
disinfectant* 

Sodium  Permanganate — Na2Mn208^ — 282 — pi*e pared  in  the  same^ 
way  as  the  K  salt  {q.  rj,  which  it  resembles  in  its  properties.  It 
enters  into  the  composition  of  Condy's  fluid,  aud  of  '*chlorozonc/* 
which  contains  NasMniOe  and  NaClO. 

Sodium  Acetate— Sodii  acetas  (U.  S.);    Sodse  acetas  (Br.)  — 
NaC2HiiO;!+3  Aq  — 82+. 34^*  crystallizes  in  large,   colorless   prisras; 
acid  and  bitter  in  taste;    quite  soluble  in  H2O,  soluble  in  alcohol; 
loses  its  Aq  in  dry  air,  and  absorbs  it  again  from  moist  air.     Heated: 
with  soda  lime,  it  yields  marsh  gas.     The  anhydrous  salt,  heated  with 
II2SO4,  yields  glacial  acetic  acid. 

Carbonates. — Three  are  known:  NajCOa,  HNaCOa,  and  HsNa*-^ 
(003)3. 

Di 3 odic  Carbo n ate — Ne n  i m  I  Cft  rho a  a  te~SoiUt — S  al  soda — Wash- 
ing  Soda=-Soda  crystals — Sodii  carbonas  (U.  P.);  Sodae  earbonas 
(BrJ—NaaCOy+lO  Aq— 100+ ISO— industrially  the  m«xst  important 
of  the  Na  compounds,  is  nianufactured  by  LebhuR-'s  or  Solvay's  pi-o- 
cesses;   or  from  cnjoiite^  a  native  fluorid  of  Xa  and  AL 

Leblanc's  process,  in  its  present  form,  consists  of  three  distinct 
processes:  (1)  The  conversion  of  NaCl  into  the  sulfate,  by  decom- 
position by  H2SO4.  (2)  The  conversion  of  the  sulfate  intoearlx)nate, 
by  heating  a  mixtnre  of  the  sulfate  with  calcium  carbonate  and  char- 
coaL     The  product  of  this  reaction,  known  as  black  ball  soda,  is  ai 


I 
I 
I 


I 

I 

I 


SODIUM 


221 


niixtare  of  sodium  carbonate  with  charcoal  and  calcinm  snlfid  and 
oxid.  (3)  The  purification  of  the  product  obtained  in  (2),  The 
ball  black  is  broken  up,  disintegrated  by  Hteatii,  and  lixiviated.  The 
solution  on  evaporation  yields  the  soda  salt  or  soda  of  commerce. 

Of  late  yeai*s  Leblanc's  process  has  been  in  great  part  replaced 
by  Solvay-g  method,  or  the  ummoHiu  prnvess,  which  is  more  eco- 
nomical, and  yields  a  purer  product.  In  this  process  sodium  clilorid 
and  Hoimonium  bicarbonate  react  upon  each  other,  with  production  of 
the  sparingly  soluble  sodium  bicarbonate,  and  the  very  soluble  am- 
monium chlorid.  The  sodium  bicarbonate  is  then  simply  eoUceted, 
dried,  and  heated,  when  it  is  decomposed  into  Na-iCO:],  H2O,  and  OO2. 
Sodium  carbonate  is  also  made  from  cryolite,  a  double  fluorid  of  sodium 
and  alumininni  found  in  rireeuland.  This  is  heated  with  limestone 
when:  AljNa,jFi2+GCat;03-=6CaPj+6C02+NaflAl'iOf;.  The  sodium 
alnminate  is  extracted  with  water  and  the  solution  treated  with  carbon 
dioxid  (obtained  in  the  first  reaction)  when  :  Na6Al206+3H.iO+ 
3C02=3Na2C03+Al2(OH)6. 

The  anhydrnus  carbouate,  SodVi  carhonas  exskcainst  (\J.  S.), 
KavCCi,  is  formed,  as  a  white  powder,  by  calcining  the  crystals.  It 
fuses  at  dull  redness,  and  gives  off  a  little  CO2.  It  combines  with  and 
dissolves  in  H/J  with  elevation  of  temperature. 

The  crystalliuc  sodium  carbonate,  Na2CO:i+10xVq,  forms  large 
rhombic  crystals,  which  effloresce  rapidly  in  dry  air ;  fuse  in  their 
Aq  at  :W  (93,2°  F J ;  are  soluble  in  H-O,  most  abundantly  at  38"* 
(100.4^  F,).     The  solutions  are  alkaline  in  reaction, 

Monosodic  Carbonate — Hfjiironodii'  airhoHafe — Bicarbonate  of 
30da — Acid  rarbmmff  (if  sodn — Vkhtj  suit — Sodii  bicarbonas  (U,  S.) 
— ^Sodse  bicarbonas  (Br J — NaHCOa — 84 — exists  in  solution  in  many 
mineral  waters.  It  is  obtained  by  the  action  of  CO2  upon  the  disodic 
Knit  in  the  presence  of  H2O;  or,  as  above  described,  by  the  Solvay 
method. 

It  crystallizes  in  rectangular  prisms,  anhydrous  and  permanent  in 
dry  air.  lu  damp  air  it  gives  off  CO2,  and  is  converted  into  the 
sesquicaibonate,  Na4ll2(CO:j)3.  When  heated  it  gives  off  CO2  and 
II2O,  and  leaves  the  disudic  carbonate.  Quite  soluble  iu  w^ater; 
abuve  70°  (158°  F.)  the  solution  gives  off  CO2.  The  solutions  are 
alkaline. 

Analytical  Characters- — (1)  Hydrofluosilicic  acid  :  gebitiuous 
ppt.,  if  not  too  dilute.  (2)  Potassium  pyroantimonate,  iu  uentral 
sointiou,  and  in  absence  of  metals  other  than  K  and  Li:  a  white, 
flocculent  ppt,;  becoming  crystalline  ou  standing*  (3)  Periodic  acid 
in  excess:  white  ppt.,  iu  not  loo  dilute  solutions.  (4)  Colors  Uie 
BoDsen  flame  yellowy  and  shows  a  brilliant  double  line  at  A=^589r> 
and  5889  (Fig.  14,  No,  2,  p.  35. 


Of>9 


MANUAL    OF     CnEMISTRY 


POTASSIUM. 

Symbol  =  K  (Kalium)— Atomic  t^eig/i^  =  39  (0=16:39.15  ;  H^ 
lim.S^)— Molecular  tceight^lS  (i)Sp,  gr.=0M5— Fuses  at  62. S"* 
{144.5^  F.)~Boih  at  667°  (1233'*  ¥,)—IHscQV€red  by  Davy,  1807— 
Namts  from  pot  ash^  and  KaU=a8hes  (Arabic).  J 

Potassium  silicates  are  widely  distributed  m  ro<?ks  and  minerals. 
The  ash  of  plants  eontain  about  10  per  cent,  of  potiissium  carbonate, 
and  this  was  formerly  the  chief  source  of  the  K  compounds.     Almost 
all   of  these  are  now  derived  from  tlie  deposits  of  carnallite:  Kl^I,™ 
MgC!2+6Aq»  and  allied  minerals  at  Stassfurt  in  Germany.  f 

It  ia  prepared  by  a  process  snnilar  to  that  followed  in  obtaining 
Na;  is  a  silver^white  metal;  brittle  at  0^  (32"^  F.);  waxy  at  15°  (59'' 
F.) ;  fuseg  at  62,5°  (144.5°  FJ  ;  distils  in  green  vapors  at  a  red  heat, 
eondensitig  in  cubic  crj'stals.  It  is  also  obtained  by  electrolysis  of 
fnsed  KHO. 

It  is  the  only  metal  which  oxidizes  at  low  temperatures  in  dry  air» 
iu  which  it  is  rapidly  coated  with  a  white  layer  of  oxid  or  hydroxid, 
and  frequently  ignites,  burniui:j  with  a  violet  flame.  It  must,  there- 
fore* be  kept  under  naphtha.  It  decomposes  H^O*  or  ice,  with  great^ 
energy,  the  heat  of  the  reaction  igniting  the  liberated  H.  It  com-™ 
liines  with  CI  with  incandescence,  and  also  unites  directly  with  S,  P, 
As,  Sb,  and  Sn.     Ileated  in  COj  it  is  oxidized,  and  liberates  C  ^ 

Oxids. — Three  are  known:  K.iO:  K-0-;  and  K-^Oi.  ^ 

Potassium  Hydroxid^Polassium  hydrate — Potash — Potassa — 
Cotnmou  cmtsfk— Potassa.  (U.  S J— Potassa  caustica  (Br.) — ^KHO 
— 56^-is  obtained  by  processes  similar  to  those  used  in  manufacturing: 
NaHO.  It  is  purified  by  solution  in  alcohol,  evaporation  and  fusion 
in  a  silver  basin,  and  casting  in  silver  moulds — potash  by  alcohol ; 
it  is  then  free  from  KOI  and  K2SO4,  but  contains  small  quantities  of 
K2CO3,  and  frequently  As. 

It  is  usually  met  with  in  cylindrical  sticks,  hard,  white,  opaque, 
and  brittle.  The  KHO  by  alcohol  has  a  bluish  tinge,  and  a  smoother 
surface  than  the  common;  sp,  gr.  2.1;  fuses  at  dull  redness;  is  freely 
soluble  in  H2O,  forming  a  strongly  alkaline  and  caustic  liquid;  less 
soluble  in  alcohol.  In  air,  solid  or  in  solution,  it  absorbs  H2O  and 
CO2,  and  is  converted  into  K2CO3.  Its  solutions  dissolve  CI,  Br» 
I,  S,  and  P.  It  decomposes  the  ammoniacal  salts,  with  liberation  ^ 
of  NH3;  and  the  salts  of  many  of  the  metals,  with  formation  offl 
a  K  salt,  and  a  metallic  hydroxid.  It  dissolves  the  proteins,  and, 
when  heated,  decomposes  them  with  formation  of  leucin,  ty rosin, 
etc.  It  oxidizes  the  carbohydrates  with  formation  of  potassium 
oxalate  and  carbonate.  It  decomposes  the  fats  with  formation  of 
soft  soaps. 


I 


POTASSIUM 


f  223 


Sulfids* — Five  are  known:  KS,  K-jS-j^  KSti,  K2S4,  and  E2S5;  also 
a  i^alfbydrater   KHS, 

Potassium  Monosulfid — K2H — 110 — is  formed  by  the  action  of 
KHO  on  KH8.  Potassium  Disulfid^ — KzS-^ — 142 — is  an  oran^re- 
oolored  solid,  formed  by  exposing  an  alcoholic  solution  of  KHS  to  the 
air.  Potassium  Trisullid — K^Sa — 174^ — a  brownish  yellow  mass^ 
obtained  by  fusing  together  K2COri  and  S  in  the  proportion:  4K^C0j+ 
10S=SO4K2+3K2Sy+4CO2.  Potassium  Pentasulfid— KqSs— 238— 
ta  formed,  as  a  brown  mass,  when  K^COa  and  8  are  fused  together  in 
the  proportion:  4K2C03+16  8==4C02+3K285+K2804.  Uver  of  Sul- 
fur— hepar  sulfuris — potassii  sulfuratum  (U.  8.;  Br.) — is  a  mixture 
ot  K2S3  and  K^Sr,. 

Potassium  Sulfhydrate — KH8^ — 72 — is  formed  by  saturating  a 
W)lution  of  KHO  with  H.i8, 

Potassium  Chlorid — *S(d  digestivum  %/rji^K€l~74.5--exists  in 
nature,  either  pure  or  mixed  with  otht-r  ehlorids;  principally  as  car- 
aallite,  KCl,  MgCl2+6  Aq.  It  crystallizes  in  anhydrous,  permanent 
cubes,  soluble  in  H2O. 

Potassium  Bromid — Potassii  bromidum  CU.  S.;  Br.)— KBr-- 
U^is  formed  either  by  decomposing  FeBra  by  K2CO3,  or  by  dissolv- 
ing Br  in  solution  of  KHO.  lu  the  latter  ease  the  bromate  formed  is 
^averted  into  KBr,  by  calcination.  It  crystallizes  in  anhydrous 
<iuhe8  or  tables;  has  a  sharp,  salty  taste;  very  soluble  in  H2OT  spar- 
ingly 80  in  alcohol.  It  is  decomposed  by  CI  with  liberation  of  Br. 
Potassium  lodid^-Potassii  iodidum  (U.  S.;  Br,) — KI — 166 — is 
obtained  by  saturating  KHO  solution  with  I,  evaporating,  and  calcin- 
i^l?  the  resulting  mixture  of  iodid  and  io^at^  with  charcoaL  It  fre- 
<iuentiy  contains  iodat^  and  earbonate.  It  crystallizes  in  cubes, 
tnmsparent  if  pure;  permanent  in  air;  anliydrous;  soluble  in  H2O 
and  ia  alcohol.  It  is  decomposed  by  CI,  HNOaand  HNO2,  with  liber- 
atjou  of  L  It  combines  with  other  iodids  to  form  double  iodids.  Its 
*f*laiioD8  dissolve  indin  and  many  raetallie  iodids. 

Potassium  Nitrate— Nitre — Saltpeter — Potassii  nitras  (U.  S.); 
Potasssc  nitras  (Br,)— KNO3 — 101 — oiicurs  in  nature,  and  is  pro- 
'I'Ji^^l  artificially,  as  a  result  of  the  decomposition  of  uitrogenized 
*'^gauie  substances.  It  is  usually  obtained  by  decomposing  native 
NaJJOa  by  boiling  solution  of  K^jCO^  or  KCl. 

h  orvjitalHzes  in  six-sided,  rhombic  prisms,  grooved  upon  the 
*^Urfaet»;  soluble  in  H2O,  with  depression  of  temperature;  more  sol- 
^hkiu  H2O  containing  NaCl;  very  sparingl 3^  soluble  in  alcohol;  fuses 
*t  350^  (662°  F.)  without  decomposition;  gives  off  O,  and  is  con- 
vmed  into  nitrite  V>elow  redness;  more  strongly  heated,  it  is  dfi'om- 
P^  into  N,  0,  and  a  mixture  of  K  oxids.  It  is  a  valuable  oxidant 
•thigh  temperatures.     Heated  with  charcoal  it  deflagrates. 


MANUAL    OF    CHEMISTRY 


Gtiii powder  is  an  intimate  mixture  of  KNO^  with  S  and  C,  in  snch 
proportion  that  the  KXOa  yields  all  the  O  required  for  the  eombustiou 
of  the  8  and  C. 

Potassium  Hypochlorite — KCIO — 90.5 — is  formed  in  sohition  l:>y 
imperfect  sutui'atiou  of  a  cooled  solution  of  KHO  with  hypoehloroiis 
acid.     An  impure  solution  is  used  in  bleaching:  Javelle  w^ater* 

Potassium  Chlorate — ^Potassii  chloras  (U.S.) — Fotassse  chloras 
(Br.) — KCIO3 — 122.5 — ii*  prepared:  (1)  bypassing  CI  tbrough  a  hoIu- 
tion  of  KHO;  (2)  liy  passing  CI  over  a  mixture  of  milk  of  lime  and  J 
KCl,  heated  to  GO''  (140°  F  J  ;  (3)  by  eleetrolysis  of  KCL  By  elee- 
trulytie  uftiou  the  KCi  is  split  into  its  ions:  2KC1^2K  +  2C1;  tbeise, 
by  seeondary  reaelions  with  H-0»  prodiiee  KCIO:  Ki*+2H20=2KHO  + 
His  ^nd  2KHO+C]2=2KC10  +  Hj,  and  at  the  temperature  generated, 
the  KCIO  yields  KCIO3:  2KeiO+n20=KC103+KCI+H2,  It  crys- 
tallizes in  transparent,  anhydrous  plates*  soluble  in  H2O;  sparingly 
soluble  in  weak  alcohol. 

It  fuses  at  400''  (752''  F.).  If  further  heated,  it  is  decomposed 
into  KCJ  and  perchlorate,  and  at  a  still  higher  temperature  the  per- 
chlorate  is  deiM>mposed  into  KCI  and  O:  2KC10;;=KC104+KCi+0'j, 
ami  KC104^KCH-202*  It  is  a  valuable  source  of  O,  and  a  more 
active  oxidant  than  KN0;r,  When  mixed  with  readily  oxidizable  sub- 
stauees,  C,  S,  P,  sugar,  tauniu,  resius,  etc.,  the  mixtures  explode 
wheu  subjected  to  shock.  With  strong  H^SOj  it  gives  off  Cl'j04,  an 
explosive  yellow  gas.  It  is  decomposed  by  HNO:i  with  formation  of 
KNOx,  KCIO4,  aud  liberation  of  tl  and  O-  Heated  with  HCl  it  gives 
oflf  a  mixture  of  CI  aud  Cl^O^,  the  latter  acting  as  an  energetic  oxi- 
dant in  solutions  in  which  it  is  generated* 

Sulfates « — Dipotassic  snliate— Potasshtm  sulfate — Potassii  sul- 
fas (U.  8 J — Potassae  sulfas  (Br.) — K^S04~174 — occurs  native;  in 
the  ash  of  many  plants;  aud  in  solution  in  mineral  waters.  It  crj^s- 
tallizes  in  right  rhombic  prisms;  hard;  permanent  in  air;  salt  and 
bitter  in  taste;  soluble  in  H2O. 

Monopotassic   Sulfate*  —  Ht^dropatassic  sulfate  —  Acid  sulfate —  1 
KHSO4— 136 — ^is    formed  as   a   by-product   in    the   manufacture  of  j 
nXOi.     When  heated  it  loses  IIjO,  and  is  converted  into  the  pyro- 
sulfate,  K282O7,  wliich,  at  a  higher  temperature,  is  decomposed  into 
K2SO4  and  SOa. 

Dipotassic  Sulfite— Fri/aA\s^/r  .^«//^£— Potassii  sulfis  (U.  S.)  — 
K2S0;j — 158 — is  formed  by  saturating  solution  of  K2CO3  wnth  SO2, 
and  evaporating  over  H28O4.  It  crystallizes  in  oblique  rh<mibo- 
hedra;  soluble  in  H2O.  Its  solution  absorbs  O  from  the  air,  with 
formation  of  K28O4. 

Potassium  Dichromate — Birliromatf  of  potash -^PotBSuii  bi- 
chromas  ( U .  S. )  — Potassae  bichromas  { Br, )  — K^CriOr  —  294*8  —  is 


POTASSIUM 


22r> 


Hf^med  by  heating  a  mixture  of  ckronip  h'on  ore  with  KNOa,  orK^COa 
Bin  air;  extracting  with  H2O;  ueutralizing  with  dilute  H2SO4;  and 
Htvaporatiog.  It  forras  large,  reddish -orange  colored  prismatic  crys- 
Htais;  soluble  in  HjO;  fuses  below  redness,  and  at  a  liigiier  tempera- 
Bfture  is  decomposed  into  0,  potassium  ehromate,  and  chromic  oxid. 
Heated  with  HCl,  it  gives  off  CI. 

Potassium  Permanganate ^Potassii  permanganas  (U.  S.); 
Potass^  pcrmaoganas  (Br  J — KjMuiiOB — 314— is  obtained  by  fusing 
a  mixture  of  manganese  dioxid,  KHO,  and  Kt^IOa,  and  evaporating 

■  the  solution  to  crystallization;  K-jMnOi,  and  KCl  are  first  formed^  on 
boiling  with  II::0,  the  mauganate  is  decomi>osed  into  K2Mn20»,  KHO 
and  M11O2. 

I  It  crystallizes  in  dark  prisms,  almost  black,  with  greenish  reflec- 
tions, which  yield  a  red  powder  when  broken.  Soluble  in  H2O, 
communicating  to  it  a  red  color,  even  in  very  dilute  solution.  It  is  a 
locwt  valuable  oxidizing  agent.  With  organic  matter  its  solution  is 
turned  to  green,  by  the  formation  of  the  manganate,  or  deposits  the 
l)rown  sesquioxid  of  manganese,  according  to  the  nature  of  the  or- 
ganic substance.  In  some  instances  the  reaction  takes  place  best  in 
lh€  cold,  in  others  under  the  influence  of  heat;  in  some  better  in  acid 
iiolutioDs,  in  others  in  alkaline  sohitions.  Mineral  reducing  agents 
act  more  rapidly.  Its  oxidizing  powers  render  its  solutions  valmible 
w  disinfectants. 

Potassium  Acetate— ^Potassii  acetas  {U.  8.);  Potassae  acetas 
(Br,)— KCsHjOs — 110 — exists  in  the  sap  of  plants;  and  it  is  by  its 
cilcimition  that  the  major  part  of  the  carbonate  of  wood  ashes  is 
formed.     It  is   prepared  by  neutralizing  acetic  acid  with  Iv^COa  or 

It  forms  crystalline  needles,  deliquescent,  and  veiy  soluble  in  Hl>Oj 
^'Wtesohdile  in  alccdjol.     Its  solutions  are  faintly  alkaline. 

Carbonates. — Dipotassic  Carbonate — Potassic  Carbonate  ^  Salt 
of  tartar — Pearl  ash^Potassii  carbonas  (U.  S.)  ;  Potassae  car- 
bonwIBr.) — K-jCO^ — 1*^8 — exists  in  mineral  waters,  and  in  the  ani- 
mal etjionomy.  It  is  prepared  industrially,  in  an  impure  form,  known 
•«  potash  or  pearlash^  from  wood  ashes,  from  the  molasses  of  beet 
wgar,  «nd  from  the  native  Stassfurth  chlorid.  It  is  obtained  pure  by 
<l^<^>mpi)sing  the  monopotassic  salt,  purified  by  several  recrystalliza 
tioBjs,  by  heat;  or  by  calcining  a  potassium  salt  of  an  organic  acid. 
Thug  eream  of  tartar,  mixed  with  nitre  and  heated  to  redness,  yields  a 
Wa<)k  mixture  of  C  and  K2CO3,  called  black  flux;  on  extracting  which 
*itli  HiO,  a  pare  carbonate,  known  as  salt  of  tartar,  is  dissolved* 

Attbydroas,  it  is  a  white,  granular,  deliquescent,  very  soluble  pow- 
d<?r.  At  low  temperatures  it  ci'ystallizes  with  2Aq.  Its  solution  is 
*lkaline. 

15 


220 


MANUAL     OF    CHEMISTRY 


Monopotassic  Carbonate — Hydropotassic  carhonaie — Bicarbonate 
— Potassii  bicarbonas  (U.  SJ  ;  Potassae  bicarbonas  (Br.) — HKCOs 
— 100 — is  obtained  by  dissolv^ing  K^C'Oa  rii  H^O,  and  satiiratiug  the 
solution  with  CO2.  It  crystaiJizes  in  oblique  rhombit*  prisms,  miioh 
less  soluble  than  the  carbonate.  In  solution,  it  is  gradually  converted 
into  the  dipotassic  salt  when  heated,  when  brought  ioto  a  vacuum,  or 
when  treated  with  an  inert  gas.  The  solutions  are  alkaline  in  reaction 
and  in  taste,  but  are  not  eaustie. 

The  substanee  used  iti  baking,  under  the  name  salaeratus,  is  thi» 
or  the  corresponding  Na  salt,  usually  the  latter.  Its  extensive  use  in 
some  parts  of  the  country  is  undoubtedly  in  great  measure  the  cause 
of  the  prevalence  of  dyspepsia.  When  used  alone  in  baking,  it 
**  raises"  the  bread  by  decomposition  into  carbon  dioxid  and  dipo- 
tassic (or  disodie)  carbonate,  the  latter  producing  disturbances  of 
digestion  by  its  strong  alkaline  reaction* 

Monopotassic  OxaJBtc—Hydropofassic  oxalnte — Blnoxalate  of  pot- 
ash— KIIC^04— '128  —  forms  transparent,  sohible,  acid  needles.  It 
occurs  along  with  the  quadroxalate  HKC204»  H2C20.i+2Aq,  in  salt  of 
lemon  or  salt  of  sorrel,  used  in  straw  bleaching,  and  for  the  removal 
of  ink -stains,  etc.  It  closely  resembles  Epsom  salt  in  appearance, 
and  has  been  fatally  mistaken  for  it.  ■ 

Tartrates.— Dipotassic  Tartrate — Pofassictartrfde — Soluble  tartar 
—Neutral  tartrate  of  potash — Potassii  tartras  (U.  S.) — Potassse  tar- 
tras  (Br.) — K2C4H.iOg^-22G — ^is  prepared  by  nentralizing  the  hydropo- 
tassie  salt  with  potassium  carbonate.  It  forms  a  white,  crystalline 
powder,  very  soluble  in  H2O,  the  solution  being  dextrogyrons, 
D*]r>=+28.48°;  soinble  in  alcohol.  Acids,  even  acetic,  decompose 
its  solution,  with  precipitation  of  the  monopotassic  salt. 

Monopotassic  Tartrate — Hj/dropotassic  tariratf — Cream  of  tartar 
—Potassii  bitartras  (U.  8. )— Potass^  bitartras  (Br.)— HKC^H^Oft 
— 188. — During  the  fermentation  of  grape  juice,  as  the  proportion  of 
alcohol  increases,  crystalline  crusts  collect  in  the  cask.  These  consti- 
tute the  crude  tartar,  or  argol,  of  commerce,  which  is  composed,  in 
great  part,  of  monopotassic  tartrate,  with  some  calcium  tartrate  and 
coloring  matter.  The  crude  product  is  purified  by  repeated  crystalli- 
zation from  boiling  H2O,  decolorizing  with  animal  charcoal,  digesting 
the  purified  tartar  with  HCl  at  20°  (68°  FJ,  washing  with  cold  H2O, 
and  crystallizing  from  hot  H^O. 

It  crystallizes  in  hard,  opaque  (translucent  when  pure),  rhombic 
prisms,  which  have  an  acidulous  taste,  and  are  very  sparingly  soluble 
in  n^O,  still  less  soluble  in  alcohoL  Its  solution  is  acid,  and  dis- 
solves many  nietallic  oxids  with  formation  of  double  tartrates.  When 
boiled  with  antimony  trioxid,  it  forms  tartar  emetic. 

It  is  used  in  the  household,  combined  with  monosodic  carbonate* 


POTASSroM 


221 


in  baking,  the  two  substances  reacting  upon  each  other  to  form 
Bochelle  salt,  with  liberation  of  carbon  dioxid. 

Baking  Powders  are  now  largely  used  as  substitutes  for  yeast  ta 
^raise"  biscuits,  cakes,  etc.  Their  action  is  based  upon  the  decom- 
position of  HNaCOs  by  some  salt  having  an  acid  reaction,  or  by  a 
weak  acid.  In  addition  to  the  bicarbonate  and  flour,  or  cornstarch 
(added  to  render  the  bulk  convenient  to  handle  and  to  diminish  the 
rapidity  of  the  reaction),  they  contain  cream  of  tartar,  tartaric  acid, 
alum,  or  acid  phosphates.  Sometimes  ammonium  sesquicarbonate  is 
used,  in  whole  or  in  part,  in  place  of  sodium  carbonate. 

The  reactions  by  which  the  CO2  is  liberated  are: 


1.  HKC4H40e      +       NaHCOa      =      NaKC4H406      + 
Monopotaule  Monoaodie  Sodium  potaaaiom 

tartrate.  carbonate.  tartrate. 


H2O       -h       CO2 
Water.  Carbon 

dioxid. 


2.  H2C4H4O.      + 
Tartaric  add. 

2NaHC08      =      Na2C4H406      +     2H2O 
Monosodio             .Disodie  tartrate.             Water, 
carbonate. 

+       2CO2 
Carbon 
dioxid. 

3. 

Al3(804)3.K2S04 

Alnininliutt 
potaatiom  alum. 

-h       6NaHC03 
Monoaodie 
carbonate. 

= 

K28O4        + 

Dipotasaic 
anlfate. 

3Na2S04    + 
Diaodie 
anlfate. 

+         AhHeOe 

Alnmininm 

hydroxid. 

+ 

Ill 

4. 

Al2(S04)3,(NH4)2S04    +    6NaHC03 

Alominium                           Monoaodie 

ammonium  alum.                      carbonate. 

= 

(NH.),SO«    + 
Diammonic 
sulfate. 

3Na2S04    + 
Diaodie 
sulfate. 

+        AljHaO. 

Alnmininm 

hydroxid. 

+ 

5. 

Al,(804)s      + 

Alnmininm 
■nlfate. 

eNaflCOs      =      3Na2S04 
Monoaodie                    Diaodie 
carbonate.                    sulfate. 

+      AljHeOe 
Aluminium 
hydroxid. 

+       6CO2 
Carbon 
dioxid. 

6. 

NaH2P04       + 
phosphate. 

NaHCOs       =    NajHPO^ 
Monoaodie                    Disodie 
carbonate.                phosphate. 

+         H2O 

Water. 

t-         CO2 

Carbon 
dioxid. 

Sodium  Potassium  Tartrate — Rochelle  salt — 8el  de  seignette 
Potassii  ct  sodiitartras  (U.  S.)— Soda  tartarata  (Br.)— NaKC4H4- 
Oi+4Aq — 210+72 — is  prepared  by  saturating  monopotassic  tartrate 
with  disodie  carbonate.  It  crystallizes  in  large,  transparent  prisms, 
which  effloresce  superficially  in  dry  air  and  attract  moisture  in  damp 
air.  It  fuses  at  70°-80°  (158-176°  F.),  and  loses  3Aq  at  100°  (212° 
P.) .     It  is  soluble  in  1.4  parts  of  cold  H2O. 

Potassium  Antimonyl  Tartrate — Tariarated  antimony — Tartar 
emetic — Antimonii  et  potassii  tartras  (U.  S.) — Antimonium  tar- 
taratum  (Br.)— (SbO)KC4BU06+XAq— 331.6— is  prepared  by  boil- 


228 


CHEMISTRY 


hig  a  tiiixtare  of  3  pts.  S\>iOa  and  4  pts.  HKC^ITiOu  in  n-jO  for  an 
hour,  filtering,  and  allowing  to  crystallize.  When  required  pure,  it 
mn8t  be  made  from  pure  materials. 

It  ery  stall  izes  in  transparent,  sol  able,  rig^ht  rhombic  octahedra, 
whieh  turn  white  in  air.  Its  solutions  are  acid  in  reactiou,  have  &^J 
nauseating  metalhc  taste,  and  are  precipitated  by  alcohol.  The  cr}'&*^H 
tals  contain  %  Aq,  which  they  lose  entirely  at  100'^  (212^^  F.),  and, 
parfially,  by  exposure  to  air.  It  is  deeomposed  by  the  alkalies,  alka- 
line earths,  and  alkaline  carbonates,  with  precipitation  of  Sb203.  The 
precipitate  is  redissolvcd  by  excess  of  soda  or  potash,  or  by  tartaric 
acid.  HCi,  H28O.1  and  HXOa  precipitate  con'espouding^  antimony! 
compounds  from  solutions  of  tartar  emetic.  It  converts  mereurie  into 
raercurous  ehlorid.  It  forms  double  tartrates  with  the  tartrates  of 
the  alkaloids. 

Potassium  Cyanid — Potassii  cyanidum  (U.  8.) — KCN— 65 — is 
obtained  by  heating  a  mixture  of  potassium  ferrocyanid  and  dry 
K2CO3,  as  long  as  effervescence  continues;  decanting^  and  erystiil- 
lizing. 

It  is  usually  met  with  in  dull,  white,  amorphous  masses.  Odorlesa 
when  dry,  it  has  the  odor  of  hydrocyanic  acid  when  moist.  It  is  deli- 
quescent, and  very  soluble  in  Hi*0;  almost  insoluble  in  alcohol.  Its 
solution  is  acrid  and  bitter  in  taste,  witii  an  after- taste  of  hydrocyanic 
acid.  It  is  very  readily  oxidized  to  the  cyanate,  a  property  which 
renders  it  valuable  as  a  reducing  agent.  Solutions  of  KCN  dissolve 
I,  AgCl,  the  eyauids  of  Ag  and  An,  and  many  metallic  oxids. 

It  is  actively  poisonous,  and  produces  its  effects  by  decomposition 
and  liberation  of  hydrocyanic  acid  {q.  r.}. 

Potassium  Ferrocyanid  — Yellow  prussiate  of  potash  —  Potas- 
sii ferrocyanidum  (U,  Sjj  Potassse  pnissias  flava  (Br.)  — 
K|[Fe{CN}6]+  3  Aq— 367.9+54.— This  salt,  the  source  of  the  other 
cyanogen  compounds,  is  manufactured  by  adding  nitrogenous  organic 
matter  (blood,  bones,  hoofs,  leather,  etc.)  and  iron  to  K2CO3  iu 
fusion;  or  by  other  processes  in  which  the  N  is  obtained  from  the 
residues  of  the  purification  of  coal  gas,  from  atmospheric  air,  or  from 
ammoniacal  compounds. 

It  forms  soft,  flexible,  lemon -yellow  crystals,  permanent  in  air  at 
ordinary  temperatures.  They  begin  to  lose  Aq  at  Gu"^  (140°  FJ,  and 
become  anhydrous  at  100*^  {212*^  Fj.  Soluble  in  H2O;  insoluble  in 
alcohol,  which  precipitates  it  from  its  aqueous  solution.  When  cal- 
cined with  KHO  or  K2CO3,  potassium  cyanid  and  cyanate  are  formed, 
and  Fe  is  precipitated.  Heated  with  dilute  HiS04,  it  yields  an  insol- 
uble white  or  blue  salt,  potassium  sulfate,  and  hydrocyanic  acid.  Its 
solutions  form»  with  those  of  many  of  the  metallic  ssdts,  iiisobihlc 
ferrocyanids;  those  of  Zd,  Pb,  and  Ag  are  white,  cupric  ferrocyanid 


'4 


POTASSIUM 


229 


'»   iiialogany- colored,  ferrons  ferrocyanid  is  bluish  white,  ferric  ferro- 
_   auid,  Prussian  blue,  is  dark  blue.     Blue  ink  is  a  solution  of  Prus- 
piii.ti  blue  in  a  solution  of  oxalit*  acid. 

I         Potassium  Ferricyanid — Red  prussiate  of  potash— K^Fea (ON)  12 
r — €>a7J — is  prepared  by  aetiug  upon  ibe  ferroeyauid  with  chloriiij  or, 
t:ter,  by  heating  the  white  i*esidtie  of  the  aetiou  of  HtjSO^  upon 
tassium  ferrocyanid,  in  the  preparation  of  hydrocyanic  acid»  with  a 
Liture  of  1  vol.  HNO;i  and  20  vols.  H:>0;   the  hlne  product  is  di- 
;t<fd  with  H2O,  and  potassium  ferrocyanid,  the  solution  filtered  and 
rvaporated-     It  forms  red,  oblique  rhombic  prisms,  almost  insoluble 
in  alcohol.     With  solutions  of  ferrous  salts  it  gives  a  dark  blue  pre- 
cipitate, TurnbulFs  blue. 

Analytical  Characters. — (1)   Platinicchlorid,  in  presence  of  HCl: 
yellow- ppt,,  KuPtClfs;   cr>'stalline  if  slowly  formed;   sparingly  soluble 
inHsO,  mueh  less  so  in  alcohol.     (2)  Tartaric  aeid  in  not  too  dilute 
^^lutiou:   white  ppt.;   soluble  in  alkalies  and  in  concentrated  acids. 
^P)  Hydrofluosilicie  acid:   translucent,  gelatinous  ppt.;  forms  slowly ; 
BOliible  in  strong  alkalies,     (4)  Perchloric  aeiil:    white  ppt.;   spar- 
ingly soluble  in  H2O;    insoluble  in  alcohol.     (.1)    Phosphoraolybdic 
J^cid:  white  ppt.;   forms  slowly.      (6)   Colors  the  Runsen  flame  violet 
(the  color  is  only  observable  through  blue  glass  in  the  presence  of 
Na).  and  exhibits  a  spectrum  of  tw^o  bright  lines:  ^^  7860  and  4045 
(Pig.  14,  No.  3,  p.  35). 

Action  of  the  Sodium  and  Potassium  Compounds  on  the 
Economy, — The  hydroxids  of  Na  and  K,  antl  iu  a  less  degree  the 
Hfljonates,  disintegrate  animal  tissues,  dead  or  living,  with  which 
tt»ey  come  in  contact,  and,  by  virtue  of  this  action,  act  as  powerful 
caustics  upon  a  living  tissue.  Upon  the  skiu,  they  produce  a  soapy 
'*^ling,  and  in  the  mouth  a  soapy  taste.  Like  the  acids,  they  cause 
^th,  either  immediately,  by  corrosion  or  perforation  of  the  stomach; 
^f.  secondarily,  after  weeks  or  months,  by  closure  of  one  or  both 
<>Pemngs  of  the  stomach,  due  to  thickening,  consequent  upon  inflam- 
tWition, 

The  treatment  consists  iu  the  neutralization  of  the  alkali  by  an 
"^Jd,  dilute  vinegar.  Neutral  oils  and  milk  are  of  service,  more  by 
•^ftMrn  nf  their  emollient  action  than  for  any  power  they  have  to 
^^tttralize  the  alkali,  by  the  formation  of  a  soap,  at  the  temperature 
^  the  body. 

The  otlier  compounds  of  Na,  if  the  acid  be  not  poisonous,  are 
^Ihout  deleterious  action,  unless  taken  in  excessive  quantity.  Com- 
^^^cisait  has  produced  paralysis  and  death  in  a  dose  of  half  a  pound. 
Thf  ueutrnl  salts  of  K,  on  the  contrary,  are  by  no  means  without  true 
I'^i^DotiJs  action  when  taken  internally,  or  injected  subcutaneously, 
^^ sufficient  quantities;    causing  dyspua:*u,  convulsions,  arrest  of  the 


230  MANUAL    OF    CHEMISTRY 

heart's  action,  and  death.  In  the  adnit  hnman  subject,  death  has 
followed  the  ingestion  of  doses  of  15-30  gms.  of  the  nitrate,  in  several 
instances;  doses  of  8-60  gms.  of  the  sulfate  have  also  proved  fatal. 

Cesium — Symbol=Cs — Atotnic  weight  =133;  and  Rubidium — 
8ymhol=Rh — Atomic  toeight^S^A — are  two  rare  elements,  discovered 
in  1860  by  Kirchoff  and  Bunsen  while  examining  spectroscopically  the 
ash  of  a  spring  water.  They  exist  in  very  small  quantity  in  lepidolite. 
They  combine  with  O  and  decompose  H2O  even  more  energetically 
than  does  E,  forming  strongly  alkaline  hydroxids. 


SILVER. 

Symbol  =Ag(Argentum)  --Atomic  w€ight  =  108  (0  =  16:107.93; 
B=l:107. 07)— Molecular  weight  =  216  {1)—8p.  flrr.  =10.4-10.54  — 
Fuises  at  1,000''  (1,832''  F.). 

Although  silver  is  usually  classed  with  the  ^^  noble  metals,'*  it 
differs  from  Au  and  Pt  widely  in  its  chemical  characters,  in  which  it 
more  closely  resembles  the  alkaline  metals. 

When  pure  Ag  is  required,  coin  silver  is  dissolved  in  HNO3  and 
the  diluted  solution  precipitated  with  HCl.  The  silver  chlorid  is 
washed,  until  the  washings  no  longer  precipitate  with  silver  nitrate: 
and  reduced,  either  (1)  by  suspending  it  in  dilute  H2S04  in  a  plati- 
num basin,  with  a  bar  of  pure  Zn,  and  washing  thoroughly,  after 
complete  reduction;  or  (2)  by  mixing  it  with  chalk  and  charcoal 
(AgCl,  100  parts;  C,  5  parts;  CaCOa,  70  parts),  and  gradually  intro- 
ducing the  mixture  into  a  red-hot  crucible. 

Silver  is  a  white  metal  ;  very  malleable  and  ductile  ;  the  best 
known  conductor  of  heat  and  electricity.  It  is  not  acted  on  by  pure 
air,  but  is  blackened  in  air  eont^iining  a  traoe  of  H2S.  It  combines 
directly  with  01,  Br,  I,  S,  P,  and  As.  Ilot  Hl>S04  dissolves  it  as  sul- 
fate, and  HNO3  as  nitrate.  The  caustic  alkalies  do  not  affect  it.  It 
alloys  readily  with  many  metals;  its  alloy  with  Cu  is  harder  than  the 
\m\v  metal. 

Silver  seems  to  exist  in  a  number  of  allotropic  modifications,  be- 
sidcH  that  in  which  it  is  ordinarily  met  with.  In  one  of  these  it  is 
brilliant,  metallic,  bluish  green  in  color,  and  dissolves  in  H2O,  form- 
ing a  dt»ep  red  solution;  in  another  it  has  the  color  of  burnished  gold, 
when  dry;  and  in  still  another  it  lias  also  a  bluish  green  color,  but  is 
iu8oluble  in  water.  Very  dilute  mineral  acids  immediately  convert 
the^e  modifications  into  normal  gray  silver,  without  evolution  of  any 

Oxids.  — Three   oxids  of   silver  are  known:   Ag40,   Ag20,   ani 


SILVER  231 

Silver  Monoxid — Protaxid — ^Argenti  oxidum — (U.  S.  ;  Br.) — 
AgiO — ^231.8 — ^formed  by  precipitating  a  solution  of  silver  nitrate 
^th  potash.  It  is  a  brownish  powder  r  faintly  alkaline  and  very 
slightly  soluble  in  H2O ;  strongly  basic.  It  readily  gives  up  its 
oxygen.  On  contact  with  ammonium  hydroxid  it  forms  a  fulmi- 
nating powder. 

Silver  Chlorid — ^AgCl — 143.4 — formed  when  HCl  or  a  chlorid  is 
added  to  a  solution  containing  silver.  It  is  white;  turns  violet  and 
black  in  sunlight ;  volatilizes  at  260°  (500°  F.) ;  sparingly  soluble  in 
HCl;  soluble  in  solutions  of  the  alkaline  chlorids,  thiosulfates,  and 
€yanids,  and  in  ammonium  hydroxid.  It  crystallizes  in  octahedra  on 
exposure  of  its  ammoniacal  solution. 

Silver  Bromid — AgBr  —  and  lodid — ^Agl — are  yellowish  pre- 
cipitates, formed  by  decomposing  silver  nitrate  with  potassium  bromid 
and  iodid.  The  former  is  very  sparingly  soluble  in  ammonium  hy- 
droxid, t^e  latter  is  insoluble. 

SUver  Nitrate  — Argenti  nitras  (U.  S.;  Br.)— AgNOg— 169.9 
— is  prepared  by  dissolving  Ag  in  HNO3,  evaporating,  fusing,  and 
recrystallizing.  It  crystallizes  in  anhydrous,  right  rhombic  plates; 
soluble  in  H2O.  The  solutions  are  colorless  and  neutral.  In  the 
presence  of  organic  matter  it  turns  black  in  sunlight. 

The  salt,  fused  and  cast  into  cylindrical  moulds,  constitutes  lunar 
caustic,  lapis  infemalis;  argenti  nitras  fusa  (U.  8.).  If,  during 
fusion,  the  temperature  be  raised  too  high,  it  is  converted  into  nitrite, 
O,  and  Ag;  and  if  sufficiently  heated  leaves  pure  Ag. 

Dry  CI  and  I  decompose  it,  with  liberation  of  anhydrous  HNO3. 
It  absorbs  NH3,  to  form  a  white  solid,  AgNOa,  3NII3,  which  gives  up 
its  NH3  when  heated.  Itti  solution  is  decomposed  very  slowly  by  H, 
with  deposition  of  Ag. 

Silver  Cyanid— Argenti  cyanidum— (U.  S.)— AgCN — 133.9— 
is  prepared  by  adding  KCN  or  HCN  to  a  solution  of  AgNOs.  It  is  a 
white,  tasteless  powder;  gradually  turns  brown  in  daylight;  insoluble 
in  dilute  acids;  soluble  in  ammonium  hj'droxid,  and  in  solutions  of 
ammoniacal  salts,  cyanids,  or  thiosulfates.  The  strong  mineral  acids 
decompose  it  with  liberation  of  HCN. 

Analytical  Characters. —  (1)  Hydrochloric  acid:  white  flocculent 
ppt.;  soluble  in  NH4HO;  insoluble  in  HNO3.  (2)  Potash  or  soda: 
brown  ppt.;  insoluble  in  excess;  soluble  in  NH4HO.  (3)  Ammonium 
hydroxid,  from  neutral  solutions:  brown  ppt.;  soluble  in  excess.  (4) 
Hydrogen  sulfid  or  ammonium  sulfhydrate:  black  ppt. ;  insoluble  in 
NH4HS.  (5)  Potassium  bromid:  yellowish  white  ppt.;  insoluble  in 
acids,  if  not  in  great  excess  ;  soluble  in  NH4HO.  (6)  Potassium 
iodid;  same  as  KBr,  but  the  ppt.  is  less  soluble  in  NH4HO. 

Action  on  the  Economy. — Silver  nitrate  acts  both  locally  as  a 


232  MJkSCJkL,    *:iP    •IHEXESESZ' 

'*r^tTr)0W9^.  tmd  ^r^&Hiiii!aiI?  m  k  ztib:  ^laeii.     Ds  laeil  aetmo.  is  jne 

'\v^  «^pfirii:;oa  't^  «»ii»ziusitar7  Xz.  'wbnsR  •isgosnaiL  eaoas  s  biaek 
*rAuu  ^TU^  :ih^rarifta  ^^f  fr^e  Ev*>u  '^txieii  acta  a*  a  <^aaAie.     W^«n 

.i#*ciAa.     T}u*^  ritoe  '^nli^raCifia  -iif  "^  Arn.  f>h«iHrv^  in  choee  to  wiun 

<vf  "Thi*^  lar>r,  asi  tlu^  ifariKaco^  »  #)iM«r7««L  afrhnwigfa  it  b  less  b&fiHSK^ 
la  iafjenufcl  ^rspuia. 

la  jirate  pwMOia^  fay  »ihr<^  aicrsD!'.  safism  eUoni  or  wkitir  of 
^^ZZ  ^hf^nSd  he  jsrrea ;  aduL  cf  tfa^  case  be  ie«L  biefixe  Ae  ij  ■jiliHiw  of 
enfmm^Mk  mk^  far  adra&e^.  <iiKtitt. 

AMMOiOUli  COICPOCKDSl 

• 

The  AMomoman  Theory. — Ahboogb  tb#  ndsesi  anmooiiim^ 
\fl^^  has  pffTjpbaMj  tMrrer  been  isolated,  its  extstimee  in  tbe  ammo- 
ri.Lieal  erj«arpooBd«  h  uXmtM  oDiv-enallj  admined.  Tbe  ammooinm 
hypfjiihem  »  baaed  efaiefly  npfm  the  foUo^viDs  facts:  (1)  tfae  elose 
reaemUaoee  fd  the  ammr/niaeal  nalts  to  thot&e  of  K  and  Xa:  (2)  when 
ammr^nia  fsa*  and  an  aeid  fpui  eome  together,  thej  unite,  miikami  libera- 
turn  of  h^drog^M^  to  form  an  ammoniacal  salt;  (3)  the  diatomie  an- 
brdridii  nnite  dirf!:fi}y  with  dry  ammonia  with  formatkm  of  the 
;immoniam  aalt  of  an  amido  a^'id: 

i¥h         -K  2NH^  =  ^50,.XHl•'XH4) 

(4)  when  Holntion^  of  the  ammoniacal  salts  are  subjected  to  elec- 
troly«ii«,  a  mixture,  having  the  r-omfx^ition  NHa+H  is  given  oflf  at 
the  negative  pf>le;  (5)  amalgam  of  KrHliuin,  in  contact  with  a  concen- 
trated Bolation  of  ammonium  chlorid,  inr'reases  much  in  volume,  and 
IH  converted  into  a  light,  Hoft  masH,  having  the  luster  of  mercury. 
ThiH  ammonium  amalgam  in  decomposed  gradually,  giving  off  am- 
monia and  hydrogen  in  the  proportion  NH3+H;  (6)  if  the  gases 
Nlla+n,  given  off  by  decomposition  of  the  amalgam,  exist  there  in 
Himple  Hohition,  the  liV)erated  II  would  have  the  ordinary  properties  of 
that  element.  If,  on  the  other  hand,  they  exist  in  combination,  the 
H  would  exhibit  the  more  energetic  affinities  of  an  element  in  the 
naHcent  state.     The  hydrogen  so  liberated  is  in  the  nascent  state. 

Ammonium  Hydroxid — Caustic  ammonia  —  NH4HO  —  35  —  has 
never  been  isolated,  pro})ably  owing  to  its  tendency  to  decomposition; 
NH4HO=NH3+Il20.  It  is  considered  as  existing  in  the  so-called 
aqueous  solutions  of  ammonia.     These  are  colorless  liquids;  of  less 


AMMONIUM    COMPOUNDS 


gp,  gr,  than  H-jO;  strongly  alkaline;  and  having  the  taste  and  odor 
of  ammonia,  which  gas  they  give  off  on  exposure  to  air,  and  more 
rapidJy  when  heated.  They  ai'e  neutralized  by  acids,  with  elevation 
of  temperature  and  formation  of  ammoniacal  snlts*  The  Aqua  aro- 
niomae(U,  SJ  and  Liq.  ammoniac  (Br.)  are  siieh  sohitions, 

Sulfids— Fonr  are  known:  (NH4}2S,  (NHJ^S-,  {NIl4):^S4,  and 
(XH4)2S5;  as  well  as  a  snlfhydrate  {NH4)HS. 

Ammonium  Sulfhydrate — NH4HS — 51 — is  formed,  in  solution, 
by  saturating  a  solution  of  NHiHO  with  H^S;  or,  anhydrous,  by 
mixing  equal  volumes  of  dry  NII3  and  dry  H-S. 

The  anhydrous  compound  is  a  colorless,  transparent,  volatile  and 
soluble  solid.  The  solution,  when  freshly  prepared,  is  colorless,  but 
»oon  becomes  yeUow  from  oxidation,  and  formation  of  ammonium 
disulfid  aud  thiosnlfate,  and  finally  deposits  sulfur. 

The  snlfids  and  hydrosulfid  of  anuuoninm  are  also  formed  during 
the  decompusition  of  protein  bodies,  and  exist  in  the  gases  formed  in 
burial  vanlts,  sewers,  etc* 

Ammonium  Chloride  Sal  ammoniac — Ammonii  chloridum  (U. 
S.;  BrJ — NHiCl— 53.5 — is  obtained  from  the  aninioniaeid  water  of 
Effts  works.  It  is  a  traushund,  filu*ous,  elastic  solid;  salty  in  taste, 
Mntral  in  reaction;  volatile  without  fusion  or  decomposition;  soluble 
in  H2O.  Its  solution  is  neutral,  but  loses  NHa  and  bccoines  aeid 
when  boiled, 

Aniaiouinm  chlorid  exists  in  small  quantity  in  the  gastric  juice  of 
the  sheep  and  dog;    also  in  the  perspiratiiui,  urine,  saliva  ami  tears. 

Ammonium  Bromid — Ammonii  bromidum  {U.  8.)^(NH4)Br 
~"^8— is  formed  either  by  combining  NHa  nud  FTBr;  by  decomposing 
^**rron9  bromid  with  NH4HO;  or  by  double  decomposition  between 
KBfand  (NH4)'iS04.  It  is  a  white,  granular  powder,  or  crvstallizes 
n»  larjje  prisms,  which  turn  yellow  on  exposure  to  air;  quite  soluble 
1^  H2O;   volatile  without  decoTu  posit  ion. 

Ammonium  lodid — Ammonii  iodidum  (U.  S,)— XIJ4I—145— is 
'^rrrietl  by  union  of  equal  volumes  of  NH:i  and  HI;  or  by  double  de- 
^'ompoKition  of  KI  aud  (NHiJi'SO^.  It  crystallizes  in  deliquescput, 
^^*7  soluble  cubes. 

Ammonium  Nitrate — ^Ammonii  nitras — (U.  S.) — (NH/)NOa^80 
"^**  pi-f^pared  by  neutralizing  HXO:i  with  ammonium  hj^droxid  or  ear- 
"^*M*te,  It  crystallizes  in  flexible,  anhydrous,  six-sided  prisms;  very 
•^luble  in  IlsO,  with  considcralile  diminution  of  temperature;  fuses 
*n50°  (302''  P.),  and  decomposes  at  210°  (410°  F.),  with  formation 
^f  mtpousoxid:  (NHjN03=N->O+2H20.  If  the  heat  be  suddenly 
%'Iie<l,  or  allowed  to  surpass  S^O"*  (482""  FJ,  NH^,  NO,  and  N2O  are 
^^nned.     When  fused  it  is  an  active  oxidant. 

Sulfates*  —  Diammonic    Sulfate  —  Ammimic   sulfate  —  Ammonii 


234 


MANUAL    OF    CHEMISTRY 


sulfas  (U,  S.)— (NH4)jS04— 132— is  obtained  by  collectingr  the  dis- 
tillatt*  from  a  mixtiii*e  of  ammoniaeal  gas  liquor  and  lime  in  H^SOi. 
It  forms  anhydrous,  soluble,  rhombic  crystals;  fuses  at  140°  (284°  F, ) , 
and  is  de<ioinposed  at  200°  (392''  F.)  into  NHa  and  H(NH«)SOi. 

Monoammonic  Sulfate — Ht^droammoHh  sidfate — Bistilfate  of  am* 
moHia-^R(Slli)^04—lli>—\s  formed  by  the  action  of  H-SO4  on 
{NH4)2SOi.  It  crystallizes  in  right  rhombic  prisms,  soluble  in  H2O 
and  in  alcohoL 

Ammonium  Acetate— (NH 4}  C'iH:{02 — 77 — is  formed  by  satnratingf 
acetic  acid  with  NH3,  or  with  aninioTiium  carbonate.  It  is  a  white, 
odorless,  very  soluble  solid;  fuses  at  86'^  (186.8'^  FJ,  and  gives  off 
NH3;  then  acetic  acid,  aud  finally  acetamid.  Liq.  ammonii  acetatis 
=  Spirit  of  Mindererus  is  mi  aqoi'ous  solution  of  this  sulL 

Carbonates.— Diammonic  Carbonate ^ — Ammonic  varboHate—Xeu - 
tra!  ammofifUM  carhonaff — (NHj)2C0a+Aq — 96+18 — has  been  ob- 
taiued  as  a  white  crystalline  solid.  In  air  it  is  rapidly  decomposed 
into  NH3   and  H(NH|)C0;^ 

Monoammonic  Carbonate— Hijdrmimmomc  carbonate — Acid  ear- 
honafp  of  ammonhi — H(NH4)C03 — 79 — is  prepared  by  saturating  a 
sotution  of  NH4IIO  or  ammonium  ssesquicarbonate  with  CO2.  It  crys- 
tallizes in  large,  rhombic  prisms;  quite  soluble  in  H2O.  At  60^ 
(14U''  FJ  it  is  decomposed  into  Nlii  and  COj. 

Ammonium  Sesquicarbonate-^  Sal  volatile™  Preston  salts  — 
Ammonii  csirbonas  (U.  S.);  Ammoniec  carbonas  (Rr.) — NILHCOa 
+NH4COJN  112—157^-18  p>reparefl  Ity  heating  a  mixture  of  NH4CI  or 
^NHiliSO^  and  chalk,  and  condensing  the  product.  It  crystallizes  in 
rhombic  prisms;  has  an  ammoniaeal  odor  and  an  alkaline  reaction; 
soluble  in  II2O.  By  exposure  to  air  or  hy  heating  its  solution,  it  is 
decomposed  into  H2O,  NHa,  and  H{NH4)C03,  It  is  not  a  pure  salt, 
but  a  mixture  of  niouoamraonic  carbonate  and  ammonium  carbamate. 

Analytical  Characters, — (1)  Entirely  volatile  at  high  tempera- 
tures. (2)  Heated  with  KHO,  the  amraoniacal  compounds  give  off 
NH.;i,  recognizable r  {a)  by  changing  moist  red  litmus  to  blue^  (h)  by 
its  odor;  {c)  by  forming  a  white  i-lond  on  contact  with  a  glass  rod 
moistened  with  HCl.  (3)  With  platiuic  chlorid:  a  yellow,  crystalline 
ppt.  (4)  With  hydrosodic  tartrate,  in  moderately  concentrated  and 
neutral  solution:  a  white  crystalline  ppt. 

Action  on  the  Economy. — ^  Solutions  of  the  hydroxid  and  car- 
bonate act  upon  animal  tissues  in  the  same  way  as  the  correspoudingf 
Na  and  K  compounds.  They,  moreover,  disengage  NH3,  which  causes 
intense  dyspnoea,  irritation  of  the  air- passages,  aud  suffocation. 

The  treatment  indicated  is  the  neutralization  of  the  alkali  by  a 
dilute  acid.  Usually  the  vapor  of  acetic  acid  or  of  dilute  HCl  must 
be  administered  by  inhalation. 


I. 


\ 


THALLIUM-CALCIUM  235 

n.     THALLIUM  GROUP. 

THALLIUM. 

8ymbol=Tl— Atomic  weight=204:  (0=16:204.1;  H=l:202.48)— 
Sp.  gr. =11. 8-11. 9— Fuses  at  294""  (Sei""  F.)— Discovered  by  Crookes 
(1861). 

A  rare  element,  first  obtained  from  the  deposits  in  flues  of  sul- 
furic acid  factories,  in  which  pyrites  from  the  Hartz  were  used.  It 
resembles  Pb  in  appearance  and  in  physical  properties,  but  differs 
entirely  from  that  element  in  its  chemical  characters.  It  resemble?' 
Au  in  being  univalent  and  trivalent,  but  differs  from  it,  and  resem- 
bles the  alkali  metals  in  being  readily  oxidized,  in  forming  alums,  and 
in  forming  no  acid  hydrate.  It  differs  from  the  alkali  metals  in  th^ 
thallic  compounds,  which  contain  Tl''  ^\  It  is  characterized  spectre 
scopically  by  a  bright  green  line — A.=5349. 


ni.     CALCIUM   GROUP. 
Metals   of   the   Alkaline    Earths. 

CALCIUM — STRONTIUM— BARIUM. 

The  members  of  this  group  are  bivalent  in  all  their  compounds; 
each  forms  two  oxids:  MO  and  MO2;  each  forms  a  hydroxid,  having 
well-marked  basic  characters. 

CALCIUM. 

8ymbol=Cei— Atomic  weight=iO  (0=16:40;  R=l -.39. 68)— Mole- 
cular weight=:80  (?) — Sp.  gr, =1.984:'— Discovered  by  Davy  in  1808 — 
Name  from  calx=lime. 

Occurs  only  in  combination,  as  limestone,  marble,  chalk  (CaCOs), 
gypsum,  selenite,  alabaster  (CaS04),  and  many  other  minerals.  In 
bones,  egg-shells,  oyster-shells,  etc.,  as  Ca3(P04)2  and  CaCOa,  and 
in  many  vegetable  structures. 

The  element  is  obtained  by  electrolysis  of  fused  CaCk,  or  by  heat- 
ing Gala  with  Na.  It  is  a  hard,  yellow,  very  ductile,  and  malleable 
metal;  fusible  at  a  red  heat;  not  sensibly  volatile.  In  dry  air  it  is 
not  altered,  but  is  converted  into  CaH202  in  damp  air ;  decomposes 
H2O;  burns  when  heated  in  air. 

Calcium  Monoxid — Quick  Lime — Lime — Calx  (U.  S.;  Br.)-^ 
CaO — 56 — is  prepared  by  heating  a  native  carbonate  (limestone); or. 


236 


MANUAL     OF    CHEMISTHY 


when  required  pure,  by  heatiEg  a  carbonate^  prepared  by  precipi- 
tation , 

It  occurs  iu  white  or  grayish,  amorphous  masses;  odorless;  alka- 
line, caustic;  almost  infusible;  sp.  gr,  2.3.  With  H2O  it  gives  off 
^eat  heat  and  is  converted  into  the  hydroxid  (slaking).  In  air  it 
becomes  air-slaked,  falling  into  a  white  powder,  having  the  compo- 
sition CaCOa,  CaHiOo. 

Calcium  Hydroxid— Slaked  lime— Calcis  hydras  {Br<) — CaH-Oi 
— ^74— is  formed  by  the  aetiou  of  H2O  on  CaO,  If  the  quantity  of 
H2O  used  be  one* third  that  of  the  oxid,  the  hydroxid  relbains  as  a 
dry,  white,  odorless  powder ;  alkaline  in  taste  and  reaction  ;  more 
soluble  in  cold  than  in  hot  H2O.  If  the  quantity  of  HjO  be  greater, 
u  creamy  or  milky  iiqutd  remains,  cream,  or  milk  of  lime;  a  solu- 
tion holding  an  excess  in  suspension.  W^ith  a  sufficient  quantity  of 
IT'iO  the  hydroxid  is  dissolved  to  a  clear  sohition,  which  is  lime  virater 
— Liquor  calcis  (U.  S.;  Br.).  The  solnhility  of  CaHsOs  is  dimin- 
ished by  the  presence  of  alkalies,  and  is  increased  by  sugar  or  man- 
nite;  Liq.  calc,  saccharatus  (BrJ;  Syrupus  calcis  (U.  S.).  Sola- 
tious  of  CaHsOa  absorb  CO2  with  formation  of  a  white  deposit  of 
CaCOa. 

Calcium  Carbid  —  CmCs — is  formed  by  the  action  of  a  very  high 
temperature  upon  a  mixture  of  quick  lime  and  carbon.  It  is  an 
amorphous  grayish  substance,  M^hi<*h  is  decomposed  by  water,  yielding 
acetylene  gas:  CaC2+2H20==CtiH2+Ca(OH)2.  One  kilo.  CaCs  yields 
440  litres  C2Q2. 

Calcium  Chlorid— Calcii  chloridum  {U.  R. ;  Br.)— CaCb— lil— is 
obtained  by  dissolving  marble  in  HCh  CaCOa+2HCl=CaCl2+H::0+ 
CO2.  It  is  bitter,  deliquescent,  very  soluble  iu  H2O;  crystallizes  witli 
6Aq,  which  it  loses  when  fused,  leaving  a  white,  amorphous  mass, 
used  as  a  drying  agent. 

Chloride  of  Lime-^Bleaching  powder— <*alx  chlorata  (U.  S,; 
Br.)^s  a  white  or  yellowish,  hygroscopic  powder,  prepared  by 
passing  CI  over  CaH^O^,  maintained  in  excess.  It  is  Vuttf^r  and  acrid 
in  taste;  soluble  in  cold  H2O;  decomposed  by  boiling  H2O,  and  by 
the  weakest  acids,  with  liberation  of  CL  It  is  decomposed  by  CO2, 
with  formation  of  CaCOa,  and  liberation  of  hypochlorous  acid,  if  it 
be  moist;  or  of  CI,  if  it  be  dry.  A  valuable  disinfectant.  The  ■' avail- 
able chloriu"  is  the  amount  liberated  by  acids,  and  should  exceed  35%, 

Bleaching  powder  was  formerly  considered  as  a  mixture  of  calcium 
chlorid  and  hypochlorite,  formed  by  the  reaction  '  2CaO+2Cl.F^ 
CaCb+Ca(CI0)2T  but  it  is  more  probable  that  it  is  a  definite  com- 
pound having  the  formula  CaCl(OCl),  which  is  decomposed  by  H2O 
into  a  mixture  of  CaCl-  and  Ca(C10)2;  and  by  dilute  HNO3  or  llSOi 
with  formation  of  HCIO. 


CALCIl'M 


t23r 


or 


Calcium  Sulfate — 011804^-136— ^oeeur^^  in  nature  as  anhydrite  ; 
and  with  2Aq  in  gypsum,  alabaster,  Mhnite  ;  and  in  solution  in 
aatoral  waters.  Terra  alba  is  groiind  gypsntn.  It  crystallizes  with 
2Aq  in  right  rhonii>ie  prisms;  sparingly  solnble  in  H2O,  more  soluble 
in  H2O  containing  free  acids  or  chlorids.  When  the  hydrated  salt 
(gJT^tim)  is  heated  to  80°  (176"^  F.),  or,  more  rapidly,  between  120'^- 
130^  (24H''-266°  Fj,  it  loses  its  Aq  and  is  rnn verted  into  a  white, 
opaque  mass,  which,  when  ground,  is  plaster  of  Paris. 

The  setting  of  plaster  when  mixed  with  H2O,  is  due  to  the  eon- 
Tersion  of  the  anhydrous  into  the  crystalline,  hydrated  salt.     The 
ordinary  plastering  should  never  be  used  in  hospitals,  as,  by  reason 
its  irregularities  and   porosity,  it    soon  beeomes  saturated  with 
tllptie    germs,   and  cannot   be  thoroughly  purified    by  disinfectants. 
Plaster  surfaces  may,  however »  be  rendered  dense,  and  be  highly  pol- 
ished, so  as  to  be  smooth  aud  impermeable,  by  adding  glue  and  alum, 
or  an  alkaline  silicate  to  the  water  used  in  mixing, 

Phospbatcs.--Thi-ee   are   known:    Ca3(P04)2;   Ca2(HP04)2,  and 
CaUlnPOJs. 

Tricalcic  Phosphate — Tribastc  or  7itHtr<iI  phosphate — Bone  phos- 
phate—Calcit  phosphas  praecipitatus  (U,  S.) — Calcis  phosphas 
(BrJ— Ca3{P04)'i— 310 — oeeut*s  in  nature,  in  soils,  guano,  nyproUtes, 
pbobphorit-e,  in  all  plants,  aud  in  every  animal  tissue  and  fluid.  It  is 
oltUiined  by  dissolving  bone- ash  in  HCl,  filtering,  and  precipitating 
vith  NHjHO;  or  by  double  decomposition  between  CaChand  an  alka- 
line phosphate.  When  freshly  precipitated  it  is  gelatinous;  when 
^O't  a  light,  white,  amorphous  powder ;  almost  insoluble  in  pure 
11:0;  soluble  to  a  slight  extent  in  H2O  containing  ammoniacal  salts, 
^r  KaCl  or  NaNOa ;  readily  soluble  in  dilute  acids,  even  in  H2O 
charged  with  carbonic  acid.  It  is  deeoraposed  l)y  H2SO4  into  CaSO^ 
^^i  Ca(H2P04)2.  Bone-ash  is  an  impure  form  of  CaaCPOi)^,  ob- 
tttiiied  by  calcining  bones,  aud  used  iu  the  manufacture  of  P  and  of 
^"ipf^rphosphate. 

Dicalcic  Phosphate— Ca2fHP04)2+2Aq— 272+36— is  a  crystal- 
!'»**.  in.soluble  salt;  formed  by  double  decomposition  between  CaCla 
^*Ki  BNa^F^O^  in  acid  solution. 

Monocalcic  Phosphate  ^  ^ceel  calcium  phosphate  —  Superphos- 
Phatcof  lime^'Ca(H2P04)5r— 234^ — exists  iu  braiu  tissue,  and  in  those 
^^iiiiul  liquids  whose  reaction  is  acid.  It  is  also  formed  when 
*^(P0i)2  is  dissolved  in  an  aeid,  aud  is  uianufactured  for  use  as  a 
"^Ottre.  by  decomposing  bone-ash  with  IJ28O4,  It  crystallizes  iu 
P^y  plates;  very  soluble  in  H2O.     Its  solutions  aie  acid. 

Cilctum  Carbonate— CaCOa— 100— the  most  abundant  of  the 
iiitoral  <'*ofT) pounds  of  €a,  exists  as  limestone,  ealcspar,  chalk,  marble^ 
Mand  spur,  and  arragonite;  and  forms  the  basis  of  corals,  shells  of 


238  MANUAL    OF    CHEMISTRY 

crastacea  and  of  molluscs,  etc.     Otoliths,  which  occur  in  the-  internal 
ear,  parotid  calculi,  and  sometimes  vesical  calculi  consist  of  CaCOa. 

Precipitated  chalk — Calcii  carbonas  praecipitata  (U.  S,  ;  Br.)t 
— is  prepared  by  precipitating  a  solution  of  CaCl2  with  one  of  Na2C03^ 
Prepared  chalk — Creta  prseparata  (U.  S.  ;  Br.) — is  native  chalk, 
purified  by  grinding  with  H2O,  diluting,  allowing  the  coarser  par- 
ticles to  subside,  decanting  the  still  turbid  lilquid,  collecting  and 
drying  the  finer  particles.  A  process  known  as  elutriation  or  levi- 
gation. 

It  is  a  white  powder,  almost  insoluble  in  pure  H2O;  much  more 
soluble  in  H2O  containing  carbonic  acid,  the  solution  being  regarded 
as  containing  monocalcic  carbonate  H2Ca(C03)2.  At  a  red  heat  it 
yields  CO2  and  CaO.    It  is  decomposed  by  acids  with  liberation  of  CO2. 

Calcium  Oxalate  —  Oxalate  of  lime — CaC204 — 128 — exists  in  the 
sap  of  many  plants,  in  human  urine,  and  in  mulberry  calculi,  and  i» 
formed  as  a  white,  crystalline  precipitate,  by  double  decomposition,, 
between  a  Ca  salt  and  an  alkaline  oxalate.  It  is  insoluble  in  H20^ 
acetic  acid,  or  NH4HO;  soluble  in  the  mineral  acids  and  in  solution 
of  H2NaP04. 

Analj^cal  Characters. — (1)  Ammonium  sulfhydrate:  nothing, 
unless  the  Ca  salt  be  the  phosphate,  oxalate  or  fluorid,  when  it  form& 
a  white  ppt.  (2)  Alkaline  carbonates:  white  ppt.;  not  prevented  by 
the  presence  of  ammoniacal  salts.  (3)  Ammonium  oxalate:  white 
ppt.,  insoluble  in  acetic  acid;  soluble  in  HCl  or  HNO3.  (4)  Sulfuric 
acid:  white  ppt.,  either  immediately  or  on  dilution  with  three  volume* 
of  alcohol;  very  sparingly  soluble  in  H2O,  insoluble  in  alcohol;  sol- 
uble in  sodium  thiosulfate  solution.  (5)  Sodium  tungstate  :  dense 
white  ppt.,  even  from  dilute  solutions.  (6)  Colors  the  flame  of  the 
Bunsen  burner  reddish -yellow,  and  exhibits  a  spectrum  of  a  number 
of  bright  bands,  the  most  prominent  of  which  are:  A.=6265,  6202, 
6181,  6044,  5982,  5933,  5543,  and  5517. 


STRONTIUM. 

Symbol^Sr—Atomic  weight=S7.5  (0=16:86.9;  R=l:S7.6)—8p, 
flfr.=2.54. 

An  element,  not  as  abundant  as  Ba,  occurring  principally  in  the 
minerals  strontianite  (SrCO-)  and  cehstine  (SrS04).  Its  compounds 
resemble  those  of  Ca  and  Ba.  Its  nitrate  is  used  in  making  red  fire. 
The  iodid  and  the  lactate  are  used  in  medicine. 

Analsrtical  Characters. — (1)  Behaves  like  Ba  with  alkaline  car- 
bonates and  Na2HP04.  (2)  Calcium  sulfate:  a  white  ppt.,  which 
forms  slowly;  accelerated  by  addition  of  alcohol.     (3)  The  Sr  cott.- 


BARIUM  231) 

pounds  color  the  Bunsen  flame  red,  or,  as  observed  throngh  blue 
grlass,  purple  or  rose  color.  The  Sr  flame  gives  a  spectrum  of  many 
bands,  of  which  the  most  prominent  are:  A=6694,  6664,  6059,  6031,^ 
4607. 

BARIUM. 

8ymbol=Ba.— Atomic  weight=137. 5  (0=16: 137.4 ;H=1:  136.3)  — 
Molecular  weight=27S, 6  {1)Sp.  flFr.=4.0— Discovered  by  Davy,  1808 
— Name  from  i3apv?=heavy. 

Occurs  only  in  combination,  principally  as  heavy  spar  (BaS04) 
and  uniherite  (BaCOa).  It  is  a  pale  yellow,  malleable  metal,  quickly 
oxidized  in  air,  and  decomposing  H2O  at  ordinary'  temperatures. 

Oxids. — Barium  Monoxid — Baryta — BaO — 153.4 — is  prepared  by 
calcining  the  nitrate.  It  is  a  grayisly-v/bite  or  white,  amorphous, 
caustic  solid.  In  air  it  absorbs  moisture  and  CO2,  and  combines  with 
H2O  as  does  CaO. 

Barium  Dioxid — Barium  peroxid — Ba02 — 169.4  —  is  prepared  by 
heating  the  monoxid  in  0.  It  is  a  grayish-white,  amorphous  solid. 
Heated  in  air  it  is  decomposed:  Ba02=BaO+0.  Aqueous  acids  dis- 
solve it  with  formation  of  a  barytic  salt  and  H2O2. 

Barium  Hydroxid — BaH202 — 171.5 — is  prepared  by  the  action  of 
H2O  on  BaO.  It  is  a  white,  amorphous  solid,  soluble  in  H2O.  Its 
aqueous  solution,  baryta  water,  is  alkaline,  and  absorbs  CO2,  with 
formation  of  a  white  deposit  of  BaCOa. 

Barium  Chlorid— BaCl2+2  Aq— 208.3+36— is  obtained  by  treat- 
ing BaS  or  BaCOs  with  HCl.  It  crystallizes  in  prismatic  plates,  per- 
manent in  air,  soluble  in  H2O. 

Barium  Nitrate— Ba(N03)2 — 261.4  —  is  prepared  by  neutralizing- 
HNO3  with  BaCOa.     It  forms  octahedral  crystals,  soluble  in  H2O. 

Barium  Sulfate — BaSOi — 233.4 — occurs  in  nature  as  heavy  spar, 
and  is  formed  as  an  amorphous,  white  powder,  insoluble  in  acids,  by 
double  decomposition  between  a  Ba  salt  and  a  sulfate  in  solution.  It 
is  insoluble  in  H2O  and  in  acids.  It  is  used  as  a  pigment,  permanent 
white. 

Barium  Carbonate — BaCOa — 197.4 — occurs  in  nature  as  witherite,. 
and  is  formed  by  double  decomposition  between  a  Ba  salt  and  a  car- 
bonate in  alkaline  solution.  It  is  a  heavy,  amorphous,  white  powder,, 
insoluble  in  H2O,  soluble  with  effervescence  in  acids. 

Analsrtical  Characters. — (1)  Alkaline  carbonates:  white  ppt.,  in 
alkaline  solution.  (2)  Sulfuric  acid,  or  calcium  sulfate:  white  ppt., 
insoluble  in  acids.  (3)  Sodium  phosphate:  white  ppt.,  soluble  in 
HN0.1.  (4)  Colors  the  Bunsen  flame  greenish -yellow,  and  exhibits 
a  spectrum  of  several  lines,  the  most  prominent  of  which  are:  A=6108„ 
6044,  5881,  5536.  • 


240 


MANUAL    OP    CHEMISTRY 


Action  on  tiie  Economy. — The  oxids  and  hydroxid  act  as  corro- 
sives, by  virtue  of  their  alkalinity,  and  also  as  true  poisons.  All 
soluble  compounds  of  Ba,  and  those  which  are  readily  converted  into 
soluble  compounds  in  the  stomachy  are  actively  poisonous.  Soluble 
sulfids,  followed  by  emetics,  are  indicated  as  antidotes.  The  sulfate, 
notwithstanding  its  insolubLiity  in  water,  is  poisonous  to  some  animals. 


IV.     MAGNESIUM   GROUP. 

MAGNESIUM — ZINC— CADMIUM. 

Each  of  these  elements  forms  a  single  oxid — a  corresponding  basic 
hydroxid,  and  a  series  of  salts  in  which  its  atoms  ai-e  bivalent. 

The  existence  of  potassium  zincate,  ZnOiK-j,  obtainable  by  tlie 
action  of  zinc  hydroxid  and  potassium  hydroxid  upon  each  other: 
Zn(OH)2+2KnO=Zn02K2+2H2O  would  seem  to  require  the  trans- 
ferral  of  zinc  to  the  amplioterie  class;  the  Zu  (OH) 2  in  tlie  above  reac- 
tion fulflUing  the  requirements  of  the  second  definition  of  acids  (see 
p.  63).  Potassium  zincate  should,  however,  be  considered  rather  as  a 
double  oxid  of  zinc  and  potassium:  ZnOKoO  or  Zu.OK.OK,  than  as 
a  true  salt  for  the  following:  reasons:  (1)  It  is  also  produced  by  the 
reaction:  Zn+2KHO=Zn02K2+H2,  in  which,  if  ZnOaK^  be  a  salt, 
KHO,  the  most  distinctly  basic  substance  known,  must  be  considered 
to  be  an  acid.  (2)  In  the  electrolysis  of  Z11O2K2  the  Zn  and  K  go  to 
the  negative  pole,  and  the  O  to  the  positive,  while  in  the  electrolysis 
of  true  ternary  salts,  such  as  KjSOi,  the  oxygen  accompanies  the  other 
electro-negative  element  to  the  positive  pole,  the  metal  going  alone  to 
the  negative.  Moreover,  the  zincates  are  nustable  bodies,  and  the 
most  prominent  function  of  Zn(0H)2  is  that  of  a  base,  as  in  the 
reaction  Zn(OH)2+H2SO4=ZnS04+2H02.  (See  Aluminium,  p.  245}, 


MAGNESIUM, 

8ymbol=Mg—Atomie  ireigJit=24  (0=16:24.36;  R— 1:24. 17}— 
Molecular  wfight=4H  iU—iSp.  i?r  =1.75— Puses  at  1000^  (1832°  F.) 
— Diseoverfid  b*f  Davtj\  1808, 

Occurs  as  carbonate  in  dolmnife  or  magnesian  limeiitone,  and  as 
silicate  in  mku,  asbestos,  soapstonf,  inefrschaiimf  talc,  and  in  other 
minerals.  It  also  accompanies  Ca  in  the  forms  in  which  it  is  found 
iu  the  animal  and  vegetable  worlds. 

It  is  prepared  by  heating  its  chlorid  with  Na,  or  by  electrolysis  of 
the  fused  chlorid.  It  is  a  hard,  light,  malleable,  ductile,  white  metal. 
It  burns  with  great  brilliancy  when  heated  in  air  (magnesium  light), 


MAGNESIUM 


241 


may  be  distilled  in  H.  The  flash  light  nsed  by  photogrraphers  is 
a  mixtm-e  of  powdered  Mg  with  an  oxidizing  agent,  KClOa  or  KNO3* 
It  decomposes  vapor  of  H2O  when  heated;  reduces  CO2  with  the  aid 
of  heat,  and  combines  directly  with  CI,  S,  P,  As  and  N,  It  dissolves 
in  dilute  a<iids,  bnt  is  not  afifeeted  by  alkaline  solutions. 

Magnesium  Oxid —Calcined  magnesia — Magnesia  (U.  S.  ;  Br.) 
— M*r<> — 40 — 'is  obtained  by  ealciiiing:  the  earbonates,  hydroxide  or 
nitratt^.  It  is  a  light,  bulky,  tasteless,  odorless,  amorphous,  w^hite 
powder;  alkaline  in  reaction;  almost  insoluble  in  H2O;  readily  sol- 
\ible  with  on  t  effervescenee  in  acids* 

Magnesium  Hydroxid— MgH202 — 58 — occurs  in  nature,  and  is 
formed  when  a  solntion  of  a  Mg  salt  is  precipitated  with  cx(*ess  of 
XaHO,  in  absence  of  ammoniacal  salts.  It  is  a  heavy,  white  powder, 
i'r<iolable  in  H2O;  absorbs  CO2. 

Magnesium  Chlond— MgCl^ — 95 — is  formed  when  MgO  or  MgCOa 
is  dissolved  in  HCl.  It  is  an  exceedingly  deliquescent,  soluble  suit* 
stance,  which  is  decomposed  into  HCl  and  MgO  when  its  aqueous 
aolntions  are  evaporated  to  dryness.  Like  all  the  soluble  Mg  cora- 
ponnds  it  is  bitter  in  taste,  and  acconiiJiinics  the  sulfate  and  bicar- 
boate  in  the  hitter  tratfrs. 

Magnesium  Sulfate — Epsom  salt — Seidlitz  ay/?/— Magnesii  sulfas 
lU.  s;)— Magnesiae  sulfas  (BrJ—MgSOi+TAq— 120+ 12G— exists 
in  solution  in  sea  water  and  in  tlic  waters  of  many  mincnil  springs, 
^8t»ecially  those  known  as  bitter  waters.  It  is  formed  l)y  the  action 
"f  HaSO*  on  MgCOs.  It  crystallizes  in  right  rhombic  prisms;  bitter, 
*Hglitly  effervescent,  and  quite  sohiljle  in  HjO.  Heated,  it  fuses  and 
mdnaWy  loses  GAq  up  to  132^  (269.6°  ¥.};  the  last  Aq  it  loses  at 
210^410°  F.). 

Phosphates. — Resemble  those  of  Ca  in  their  e'onstitntion  and 
P'*oiH?rties,  and  accompany  tliem  in  the  situations  in  which  they  occur 
"i  the  animal  body,  but  in  much  smaller  quantity. 

Magnesium  also  forms  double  phosphates,  constituted  by  the 
>^«Witntion  of  one  atom  of  tlie  liivalent  metal  for  two  of  the  atoms 
<*f  basie  hydrogen,  of  a  molecule  of  phosphoric  acid,  and  of  an  atom 
^''alkiiUne  metal,  or  of  an  ammonium  group,  for  the  remaining  basic 

Ammonio-Magnesian  Phosphate^Triple  phosphate — Mg(NHi}- 
^4+6Aq — 137+ 108-^ is  produced  wixen  an  alkaline  phosphate  and 
*^HiHO  ai'e  added  to  a  solution  containing  Mg.  When  heated  it  is 
converted  into  magnesium  pyrophosphate,  Mg','P:jOT,  in  which  form 
«*P0|  and  Mg  are  usually  weighed  in  quantitative  analysis. 

Carbonates.— Magnesium  Carbonate — Neutral  mrhonate — MgCOa 
^S4— exists  native  in  magnesitf,  and,  combined  with  CaCO^,  in  doh- 
"*^'^  It  cannot  be  formed,  like  other  carbonates*  by  decomposing 
le 


242  MANUAL    OF    CHEMISTRY 

a  Mg  salt  with  an  alkaline  carbonate,  but  may  be  obtained  by  passing- 
CO2  through  H2O  holding  tetramagnesie  tricarbonate  in  suspension. 

Trimagnesic  Dicarbonate  —(MgC03)2MgH202+2Aq— 226+36— 
is  formed,  in  small  crystals,  when  a  solution  of  MgSOi  is  precipitated 
with  excess  of  Na2C03,  and  the  mixture  boiled. 

Tetramagnesie  Tricarbonate — Magnesia  alba — Magnesii  carbo* 
nas  (U.  S.)— Magnesiae  carbonas  (Br.)— (MgC03)3MgH202+3Aq— 
310+54 — occurs  in  commerce  in  light,  white  cubes,  composed  of 
a  powder  which  is  amorphous,  or  partly  crystalline.  It  is  prepared 
by  precipitating  a  solution  of  MgSOi  with  one  of  Na2C03.  If  the 
precipitation  occur  in  cold,  dilute  solutions  (Magnesiae  carbonas  Icevis, 
Br.),  very  little  CO2  is  given  off;  a  light,  bulky  precipitate  falls,  and 
the  solution  contains  magnesium,  probably  in  the  form  of  the  bicar- 
bonate Mg(HC03)2.  This  solution,  on  standing,  deposits  crystals  of 
the  carbonate,  MgCOa+SAq.  If  hot  concentrated  solutions  be  used, 
and  the  liquid  be  then  boiled  upon  the  precipitate,  CO2  is  given  off, 
and  a  denser,  heavier  precipitate  is  formed,  which  varies  in  compo- 
sition, according  to  the  length  of  time  during  which  the  boiling  is 
continued,  and  to  the  presence  or  absence  of  excess  of  sodium  car- 
bonate. The  pharmaceutical  product  frequently  contains  (MgC08)4, 
MgH202+4H20,  or  even  (MgC03)2,MgH202+2H20.  All  of  these 
compounds  are  very  sparingly  soluble  in  H2O,  but  much  more  soluble 
in  H2O  containing  ammoniacal  salts. 

Analj^ical  Characters. —  (1)  Ammonium  hydroxid  :  voluminous, 
white  ppt.  from  neutral  solutions.  (2)  Potash  or  soda:  voluminous, 
white  ppt.  from  warm  solutions,  prevented  by  the  presence  of  NH4 
salts,  and  of  certain  organic  substances.  (3)  Ammonium  carbonate: 
slight  ppt.  from  hot  solutions  ;  prevented  by  the  presence  of  NH4 
salts.  (4)  Sodium  or  potassium  carbonate:  white  ppt  ,  best  from  hot 
solution;  prevented  by  the  presence  of  NH4  compounds.  (5)  Disodic 
phosphate:  white  ppt.  in  hot,  not  too  dilute  solutions.  (6)  Oxalic 
acid:  nothing  alone,  but  in  presence  of  NH4HO,  a  white  ppt.;  not 
formed  in  presence  of  salts  of  NH4. 

ZINC. 

8yn(bol=Zu— Atomic  tmV/«<  =  65  (O  =16:65.4  ;  H  =1:64.88)— 
Molecular  weight=6o—Sp.  gr. =6,862-7. 215— Fuses  at  415°  (779°  F.) 
—Distils  at  1040°  (1904°  F.). 

Occurs  principally  in  calamine  (ZnCOs) ;  and  blende  (ZnS) ;  also 
as  oxid  and  silicate;  never  free.  It  is  separated  from  its  ores  by 
calcining,  roasting,  and  distillation. 

It  is  a  bluish -white  metal;  crystalline,  granular,  or  fibrous;  quite 
malleable  and  ductile  when  pure.     The  commercial  metal  is  usually 


ZINC  243 

brittle.     At  130''-150°  (266°-302°  P.)  it  is  pliable,  and  becomes  brit- 
tle again  above  200°-210°  (392^10°  P.). 

At  500®  (932°  P.)  it  burns  in  air,  with  a  greenish -white  flame, 
and  gives  off  snowy -white  flakes  of  the  oxid  {lana  philosophica;  nil 
album;  pampholix).  In  moist  air  it  becomes  coated  with  a  fllm  of 
hydrocarbonate.     It  decomposes  steam  when  heated. 

Pure  H2SO4  and  pure  Zn  do  not  react  together  in  the  cold.     If  the 

acid  be  diluted,  however,  it  dissolves  the  Zn,  with  evolution  of  H, 

and  formation  of  ZnSOi,  in  the  presence  of  a  trace  of  Ft  or  Cu.     The 

commercial  metal  dissolves  readily  in  dilute  H2SO4,  with  evolution  of 

H,  and  formation  of  ZnSOi,  the  action  being  accelerated  in  presence 

of  Ft,  Cu,  or  As.      Zinc  surfaces,  thoroughly  coated  with  a  layer  of 

an  amalgam  of  Hg  and  Zn,  are  only  attacked  by  H2SO4  if  they  form 

part  of  closed  galvanic  circuit;  hence  the  zincs  of  galvanic  batteries 

are  protected  by  amalgamation.     Zinc  also  decomposes  HNO3,  HCl, 

and  acetic  acid.     Zinc  dissolves  in  strong  solutions  of  the  caustic 

alkalies  with  evolution  of  hydrogen  and  formation  of  double  oxids 

(zincates)  :    Zn+2KHO=Zn02K2+H2.      It   also  decomposes   many 

metallic  salts  in  solution  with  deposition  of  the  metal. 

When  required  for  toxicological  analysis,  zinc  must  be  perfectly 
free  from  As,  and  sometimes  from  P.  It  is  better  to  test  samples 
until  a  pure  one  is  found,  than  to  attempt  the  purification  of  a  con- 
taminated metal. 

Zinc  surfaces  are  readily  attacked  by  weak  organic  acids.  Vessels 
of  galvanized  iron  or  sheet  zinc  should  therefore  never  be  used  to  con- 
tain articles  of  food  or  medicines. 

Zinc  Oxid — ^Zinci  oxidum  (U.  S.;  Br.) — ZnO — 81.4 — is  prepared 
«ther  by  calcining  the  precipitated  carbonate,  or  by  burning  Zn  in  a 
cnrrent  of  air.  An  impure  oxid,  known  as  tutty,  is  deposited  in  the 
floes  of  zinc  furnaces,  and  in  those  in  which  brass  is  fused.  When 
obtained  by  calcination  of  the  carbonate,  it  forms  a  soft,  white,  taste- 
'ws,  and  odorless  powder.  When  produced  by  burning  the  metal,  it 
occurs  in  light,  voluminous,  white  masses.  It  is  neither  fusible, 
volatile,  nor  decomposable  by  heat,  and  is  completely  insoluble  in 
neutral  solvents.  It  dissolves  in  dilute  acids,  with  formation  of  the 
corresponding  salts. 

It  is  used  in  the  arts  as  a  white  pigment  in  place  of  lead  car- 
JwDate,  and  is  not  darkened  by  H2S. 

Zinc  Hydroxid — ZnH202 — 99.4 — is  not  formed  by  union  of  ZnO 
andHjO;  but  is  produced  when  a  solution  of  a  Zn  salt  is  treated 
^th  KHO.  Preshly  prepared,  it  is  very  soluble  in  alkalies,  and  in 
whtions  of  NH4  salts. 

Zinc  Chlorid — Butter  of  zinc— Zinci  chloridum  (U.  S.;  Br.) — 
ZnCl2+Aq— 136.3+18— is  obtained  by  dissolving  Zn  in  HCl,  or  by 


244 


MANUAL    OF    CHEMISTRY 


heating  Zn  in  CI.  It  is  a  soft,  white,  very  deliquescent,  fusible,  vola- 
tile mass;  very  soluble  in  H2O,  somewhat  less  so  in  aI(*oboL  Its 
solution  has  a  baruiDg,  metallic  taste;  destroys  vegetable  tissues;  dis- 
solves silk;  and  exerts  a  strong  dehydi*ating  action  upon  organic  sub- 
stances ill  general. 

In  dihite  solntion  it  is  used  as  a  disinfectant  and  antiseptic  (Bur- 
neti-s  flnid) ,  as  a  preservative  of  wood  and  as  an  embabniog  injection. 

Zinc  Sulfate— White  vitriol^Zinci  sulfas  (U.S.;  Br.)— ZnS04+ 
7}Aq — 161,4  + nl8^s  formed  when  Zn,  ZnO,  ZnS,  or  ZuCO^  is  dis- 
solved in  diluted  HaSOi.  It  crystallizes  below  30^  (KfJ''  F. )  with  7  Aq ; 
atSQ*"  (SO'' F.)  with  6  Aq;  between  40*'-50''  (104''-122*'  F.)  with 
5  Aq;  at  0*^  (32*^  FJ  from  concentrated  acid  sohition  with  4  Aq. 
From  a  Iwiling  solution  it  is  precipitated  by  concentrated  Hi!S04  with 
2  Aq;  from  a  saturated  solution  at  KK)''  {212''  FJ  with  1  Aq;  and 
anhydrous^  when  the  salt  with  1  Aq  is  heated  to  238^  (4G0''  P.). 

The  salt  usnally  met  with  is  that  with  7  Aq,  which  is  in  large, 
colorless,  four- sided  prisms;  efflorescent;  very  soluble  in  II^O,  spar- 
ingly soluble  in  weak  alcohol.  Its  solutions  have  a  strong,  styptic 
taste:  coagnhitc  albumen  when  added  in  moderate  quantity,  the  coag- 
ulnm  dissolving  in  an  excess;  and  form  insoluble  precipitates  with 
the  tannins. 

Carbonates. — Zinc  Carbonate — ZnCOa — 125.4 — occurs  in  nature 
as  eahimine.  If  an  alkaline  carbonate  be  added  to  a  solution  of  a  Zn 
salt,  the  neutral  carbonate,  as  in  the  cnse  of  Mg,  is  not  formed,  but 
an  oxycarbonate,  nZnCO:u  n7,ull'jCh  [Zinci  earbonas  (U.  S.;  Br,)], 
whose  compositiou  varies  with  the  conditions  under  which  it  is  formed. 

Analytical  Characters. — (1)  K,  Xa  or  XH^  hydroxid:  white  ppt., 
soluble  in  excess.  (2)  Carhouate  of  K  or  Na:  white  ppt.,  in  absence 
of  NH4  salts.  (3)  Hydrogen  snlM,  in  neutral  solntion:  white  ppt* 
In  presence  of  an  excess  of  a  mineral  acid,  the  formation  of  this  ppt. 
is  prevented,  unless  sodium  acetiite  he  also  present.  (4)  Ammonium 
sulfhydrate  :  white  ppt.,  insoluble  in  excess,  in  KHO,  NII4HO,  or 
acetic  acid  ;  solnhle  in  dilute  mineral  acids.  (5)  Ammonium  car- 
bonate :  white  ppt.,  solnhle  in  excess,  (6)  Disodic  phosphate,  in 
absence  of  NH^  salts  :  white  ppt,,  soluble  in  acids  or  alkalies.  (7) 
Potassium  ferrocyanid:  white  ppt,,  insoluble  in  HCl. 

Action  on  the  Economy,— All  the  compounds  of  Zn  which  are 
solnhle  in  the  digestive  fluids  behave  as  true  poisons;  and  solutions 
of  the  chlorid  (in  common  use  by  tinsmiths,  and  in  disinfect) ngf  fluids)       1 
have  also  well -marked  corrosive   properties.     When  Zn  compounds 
are  taken,  it  is  almost  invariably  by  mistake  for  other  substances:  th<      jj 

sulfate  for  Epsom  salt,  and  solutions  of  the  chlorid  for  various  liquids ^ 

such  as  gin,  fluid  magnesia,  vinegar,  etc. 

Metallic  zinc  is  dissolved  by  solutions  containing  NaCl,  or  organL^^^ 


CADMIUM— ALUMINIUM 


245 


CADMIUM. 


^acids,  for  wbich  reason  articles  of  food  kept  in  vessels  of  galvanized 
iron  become  contaniinated  with  zinc  compounds,  and,  if  eaten,  pro- 
duce more  or  less  intense  symptoms  of  intoxication.      For  the  same 
reason  materials  intended  for  analysis  in  cases  of  supposed  poisonings 
^mhgmld  ftever  he  packed  in  jars  dosed  by  zinc  caps, 

U        89mbol=Cd—Aimtic  weight=in.o  (0=16:112.4;  H=l:111.5)— 
■^  MohcHlar  wehjhi^ni,B—Sp.  i?r  =8.604— F«m  ai  227.8''  (442''  F.) 
—B*Hh  at  Smf  {KiSO"*  F.). 

■  A  white  metal,  malleable  and  ductile  at  low  temperature,  brittle 
when  heated;  which  aceoni panics  Zn  in  certain  of  its  ores.  It  resem* 
hies  zinc  in  its  physical  as  well  as  its  chemical  characters.  It  is  used 
in  certain  fnsible  alloys,  and  its  iodid  is  used  in  photography. 

Analytical  Characters, — Hydrogen  sulfid:  bright  yellow  ppt.; 
insoluble  in  NHilltS,  and  in  dilute  acids  and  alkalies,  soluble  in  boil- 
ing HNO3  or  HCL 


V.     ALUMINIUM  GROUP, 

BERYLLIUM^ — ALU3HINIUM — SCANDIUM^ — GALLIUM — INDIUM. 

These  elements  form  one  series  of  compoduds,  con-csponding  to 
the  ferric,  containing  the  group  (Ma)"'*,  but  no  compounds  eorrespond- 
iiig  to  the  ferrous  M"  and  the  Ni  and  Co  salts  are  known.  Indeed^ 
^^^irtain  organic  compounds,  such  as  aluminium  acetylacetonate, 
AM05H7O2)3,  seem  to  contain  single,  trivalent  atoms  of  the  metal. 
The  existence  of  the  ahirainates,  snch  as  K2AI2O4,  would  seem  to  place 
iluTnimum  in  the  amphoteric  class.  These  compounds,  which  are 
formed  bv  tlie  reactions  :  Alj(0H),s+2KH0  =  KoAbO*  +  4H2O,  and 
AI:+2KHO+2H30=K2Al204+3H2,  are  double  oxids  rather  than 
iMlU.  They  resemble  the  zincates  and  what  has  been  said  concerning 
compounds  (see  p.  240}  applies  also  to  the  aluminates. 


ALUMINIUM. 

9jimhol  =  Al— Atomic  weight=^  (0  =  16:27.1;    H=l;26.88)~ 
tolmhr  weight^o'y  (!)— Np.  (jr.=2M-2,61—Fusfs  at  about  700° 
1(1292°  F.) — Name  from  alnmen^ahtm — IJiscovered  by  WoMer,  1827. 

Occurrence* — Exceedingly  abundant  in  the  clays  as  sitimte.  Also 
'^^  f(i(hpar,  mica,  and  fiarncf^  topaz,  and  emerald.  As  a  flunrirl  \n 
*^'*^«»  and  as  a  hydroxid  in  heauxite. 


246  MANUAL    OF    CHEMISTRY 

Preparation. — (1)  By  decomposing  vapor  of  alnminium  chloric! 
by  Na  or  K  (Wohler).  (2)  Aluminium  hydroxid,  mixed  with  sodium 
chlorid  and  charcoal,  is  heated  in  CI,  by  which  a  double  chlorid  of 
Na  and  Al  (Na2Al2Cl8)  is  formed.  This  is  then  heated  with  Na, 
when  Al  and  NaCl  are  produced.  (3)  These  "chemical  methods" 
have  been  replaced,  in  the  industrial  preparation  of  aluminium,  by 
the  electrolytic  method,  in  which  a  mixture  of  cryolite  and  beauxite 
is  treated  in  an  electric  furnace. 

Properties. — Physical, — A  bluish -white  metal;  hard;  quite  mal- 
leable, and  ductile,  when  annealed  from  time  to  time;  slightly  mag- 
netic; a  good  conductor  of  electricity;  non- volatile;  very  light,  and 
exceedingly  sonorous. 

Chemical. — It  is  not  affected  by  air  or  O,  except  at  very  high  tem- 
peratures, and  then  only  superficially.  If,  however,  it  contain  Si,  it 
burns  readily  in  air,  forming  aluminium  silicate.  It  does  not  decom- 
pose H2O  at  a  red  heat;  but  in  contact  with  Cu,  Pt,  or  I,  it  does  so 
at  100°  (212°  F.).  It  combines  directly  with  B,  Si,  CI,  Br,  and  I. 
It  is  attacked  by  HCl,  gaseous  or  in  solution,  with  evolution  of  H, 
and  formation  of  AI2CI6.  It  dissolves  in  alkaline  solutions,  with 
formation  of  aluminates,  and  liberation  of  H.  It  alloys  with  Cu  to 
form  a  golden  yellow  metal  (aluminium  bronze) . 

Aluminium  Oxid — Alumina — AI2O3 — 102.2  —  occura  in  nature, 
nearly  pure,  as  corundum,  emery,  ruby,  sapphire,  and  topaz;  and  is 
formed  artificially,  by  calcining  the  hydrate,  or  ammonia  alum,  at  a 
red  heat. 

It  is  a  light,  white,  odorless,  tasteless  powder  ;  fuses  with  diffi- 
culty; and,  on  cooling,  solidifies  in  very  hard  crystals.  Unless  it 
has  been  heated  to  bright  redness,  it  combines  with  H2O,  with  eleva- 
tion of  temperature.  It  is  almost  insoluble  in  acids  and  alkalies. 
II2SO4,  diluted  with  an  equal  bulk  of  H2O,  dissolves  it  slowly  as 
(AI2)  (804)3.  Fused  potash  and  soda  combine  with  it  to  form  alu- 
minates.    It  is  not  reduced  by  charcoal. 

Aluminium  Hydroxid — Aluminium  hydrate — Aluminii  hydras 
(U.  S.) — AI2II0OC— 136.2— is  formed  when  a  solution  of  aluminium 
salt  is  decomposed  by  an  alkali,  or  alkaline  carbonate.  It  constitutes 
a  gelatinous  mass,  which,  when  dried,  leaves  an  amorphous,  translncid 
mass;  and,  when  pulverized,  a  white,  tasteless,  amorphous  powder. 
When  the  liquid  in  which  it  is  formed  contains  coloring  matters, 
these  are  carried  down  with  it,  and  the  dried  deposits  are  used  as 
pigments,  called  lakes. 

When  freshly  precipitated,  it  is  insoluble  in  H2O;  soluble  in 
acids,  and  in  solutions  of  the  fixed  alkalies.  When  dried  at  a  tem- 
perature above  50°  (122°  F.),  or  after  24  hours'  contact  with  the 
mother  liquor,   its  solubility  is  greatly  diminished.     With  acids  it 


ALUMINIUM 


forms  salts  of  alamiuiiirii;  inid  with  alkalies,  aluminates  of  the  alka- 
li ue  metal.  Heated  to  near  redtiess,  it  is  decomposed  iato  Al-jOa,  and 
II2O.  A  soluble  modi tieat ion  is  obtained  by  dialyzinj^  a  solution  of 
Al:£HeO«  in  AI^CIa,  or  by  heating  a  dilute  solution  of  alumiuiuni  aee- 
tate  for  24  hours. 

Aluminates  are  for  the  juost  part  eryslalliue»  soluble  compounds, 
obtained  by  Uie  ac^tion  of  uietallte  oxids  or  liydroxids  upon  iiluniiua. 
Potassium  aluminate,  K:'Al204  4- 3Aq.  is  iurmed  b\  dissohint^ 
recently  precipitated  aluminium  hydroxid  in  potash  solution.  It 
forms  white  crystals,  very  soluble  in  H^O,  insoluble  iu  alcohol; 
caustic  and  alkaUue.  By  a  large  quantity  of  li>0  it  is  deconiptisrd 
ioto  nhiniiuiuui  hytlroxid    and  a  more  alkaline  salt,  KtjAliOo. 

Sodium  Aluminate. — The  alnmiriate  NaoAI-Ofi  is  formed  when 
cryolite  is  heated  with  calcium  carbonate  (see  sodium  carhouate) . 
Another  salt,  having  the  composition  NaoAUOti,  is  prepared  by  heat- 
ing to  redness  a  mixture  of  1  pt.  sodium  carbonate  and  2  pis  id'  a 
uative  ferruginous  aluminium  hydrate  (beauxite).  Both  salts  are 
Bolnble  in  H2O,  and  are  decomposed  by  carbonic  acid,  with  precipita* 
tion  of  ahi minium  hydroxid. 

Aluminium  Chlorid — Al^Cle — 266.9 — is  prepared  by  passing  CI 
over  a  mixture  of  AiiOa  and  C,  heated  to  redness,  or  by  heating  clay 
in  a  mixture  of  gaseous  HCI  and  vapor  of  CS2. 

It  crystallizes  in  colorless,  hexagonal  prisms;  fusible;  vohitile; 
deliquescent;  very  soluble  in  H2O  and  in  alcohol,  From  a  hot,  eon* 
centraled  solution,  it  separates  in  prisms  with  12Aq.  At  very  high 
l^'tuperatnres  AI2CI0  appears  to  be  dissociated  into  2AICI3. 

The  disinfectant  called  chloralum  is  a  solution  of  impure  AliCJe. 
Aluminium    Sulfate — Aluminii    sulfas   (U.   S,)~(Al2)  (80»)3+ 
18Aq— :H2.2  +  324 — is  obtained  by  dissolving  Al2HB0fl  iu  H280i^   or 
(iudtistrially)  by  heating  clay  with  HjSO*, 

It  crystallizes,  with  difficulty,  in  thin,  flexible  plates;  soluble  in 
B2O;  ver>*  sparingly  soluble  in  alcohol.  Heated,  it  fuses  in  its  Aq, 
whiolj  it  frraduaily  hises  up  to  2<X)^  (392°  FJ,  when  a  white,  amor* 
phiHis  powder »  (Al-:)  (SO^)^!  remains:  this  is  decomposed  at  a  red 
''**t,  leaving  a  residue  ot  pure  alumina. 

Alums  —  are  double  sidfates  of  the  alkaline  metals,  and  th© 
Wjther  sulfates  of  this,  or  the  iron  group.  VVlien  crystallized, 
%  ha%^e  the  general  formula:  {M-j)''*  (80i)r*,  R^SO^+24Aq,  in 
^kwh  (M)  may  be  (Pe^)*  (Mns),  (Crj),  (Al2)i  or  (Ga^);  and  R2  may 
^  ^,  Na2,  Eb2,  C83,  Tlsi  or  (NH^)2.  They  are  isomorphous  with 
^h  other* 

Abmcn  (IT.  8,)— Ali(804)3,  K2SO*+24Aq— 51G.5+432— is  man- 
'"'^red  from  '*alum  shale/^  and  is  formed  when  solutions  of  the 
•^ateg  of  Al  and  K  are  mixed  in  suitable  proportion. 


248 


MANUAL    OF    CHEMISTRY 


It  eiystallizea  in  large,  transparent,  regular  octabedra^  has  a 
sweetish,  astringent  taste,  and  is  readily  soluble  in  H^O*  Heated,  it 
fuses  in  its  Aq  at  92  "^  (197.6^  F.) ;  and  gradnally  loses  45.5  per  cent, 
of  its  weight  of  H2O ,  as  the  temperature  rises  to  near  redness.  The 
product^  known  as  burnt  alum  =  Elumen  exsiccatum  (U,  8.),  is 
(AD^CSOJa,  K2SO1,  and  is  slowly,  but  completely,  soluble  in  20-30 
pis.  H2O.  At  a  bright  red  heut,  8Ch  and  O  are  given  off,  and  Al^Oj 
and  potassium  sulfate  remain;  at  a  higher  temperature,  potassium 
alumiuate  is  formed.  Its  solutions  are  acid  in  reaction;  dissolve  Zo 
and  Fe  with  evolution  uf  II;  and  deposit  AI:;HflOfi  when  treated  with 
ammonium  bydroxid, 

Alumen  (Br.)— Al2(S04)3.  (NHi)2S04+24Aq— 474.2+432— is  the 
compound  now  usually  met  with  as  alum,  both  in  this  eouutry  and  in 
Eugbiud.  It  dillers  from  potash  alum  in  being  more  soluble  in  II2O, 
between  20—30°  (68^-86°  FJ,  and  less  soluble  at  other  temperatures; 
and  in  the  action  of  beat  upon  it.  At  92°  {197.6'^  FJ  it  fuses  in 
its  Aq;  at  205°  (401°  F.),  it  loses  its  ammonium  sulfate,  leaving  a 
white,  hygroscopic  substance,  very  slowly  and  incompletely  soluble 
in  H2O*  More  strongly  heated,  it  leaves  alumina.  Alum  is  used  in 
dyeing,  and  in  purification  of  water  by  precipitation. 

Silicates— are  very  abundant  in  the  different  varieties  of  day^ 
feldspar,  alhite,  htbrmhritt,  mica,  etc.  The  clays  are  hydra  ted  alu- 
minium silicates,  more  or  less  coutaniioalt^d  with  alkaline  and  earthy 
salts  ami  iron,  to  which  lust  certain  clays  owe  tht'ir  color.  The  purest 
is  kaolin,  or  porcelain  clay,  a  white  or  grayish  powder.  They  are 
largely  used  iti  the  manufacture  of  the  different  varieties  of  bricks^ 
terra  cotta,  pottery,  and  porcelain,  Forcehtru  is  made  from  the  purer 
clays,  mixed  with  suud  iiud  feldspar;  the  former  to  prevent  shrinkage, 
the  latter  to  bring  the  mixture  into  partial  fusion,  and  to  render  the 
product  translucent.  The  fashioned  articles  are  subjected  to  a  first 
baking.  The  porous,  baked  clay  is  then  coated  with  a  glaze,  usually 
composed  of  oxid  of  lead,  sand  and  salt.  Duriug  a  second  baking 
the  glaze  fuses,  and  coats  the  article  witii  a  bard,  impermeable  layer. 
The  coarser  articles  of  pottery  are  glazed  by  throwing  sodium  ehlorid 
into  the  fire;  tbe  salt  is  volatilized,  and  on  contact  witli  the  hot  alu* 
minium  silicate,  deposits  a  coating  of  the  fusible  sodium  silicate^ 
which  hai'dens  on  cooling. 

Analytical  Characters*— (1)  Potash,  or  soda:  white  ppt.,  soluble 
in  excess.  (2)  Ammonium  bydroxid:  white  ppt.,  almost  insoluble  in 
excess,  especially  in  presence  of  amnioniacal  salts.  (3)  Sodium  phos- 
phate: white  ppt.,  readily  soluble  in  KIIO  and  NaHO,  but  not  in 
NHiHO;  soluble  in  mineral  acids,  but  not  in  acetic  acid.  (4)  Blow* 
pipe — on  charcoal  docs  not  fuse,  and  moistened  with  cobalt  nitrate 
solution  turns  dark  .^ky-bluc. 


NICKEL— COBALT 


24U 


VI.     NICKEL   GROUP. 

NICKEL^ — COBALT . 

These  two  elements  bear  some  resemblance  chemically  to  those  of 
the  Fe  group?  from  which  they  differ  in  forraiu^,  so  fai*  as  known, 
no  com  pounds  similar  to  the  ferrates,  ehromates,  and  manganates, 
UDlei^s  the  barium  eobaltite,  described  by  Rousseau,  be  such.  They 
form  compounds  corresponding  t^  FegOa,  but  those  corresponding  to 
the  ferric  salts  are  either  wanting  or  exceedingly  unstable. 

NICKEL, 

8ymhol=m=Alomic  might— dH  fO=16:58.7;  H=i : 58.22 )—fifp. 
^.=8.637. 

Occurs  in  eorabi nation  with  S.  and  with  S  and  As. 
It  is  a  white  metal,  hard,  slightly  magnetic,  not  tarnished  in  air. 
GfTtnan  silver  is  an  alloy  of  Ni,  Vn,  and  Zn.     Nickel  is  now  exten- 
aively  used  for  plating  upon  other  metals,  and  for  the  manufacture  of 
dishes,  etc.  for  use  in  the  laboratory.     Its  salts  ai-e  green. 

Kickelous  Sulfate — NiSOj— is  obtained  by  dissolving  the  metal. 
hyjroxid  or  carbonate  in  HjSO<.  It  forms  green  crystiils  with  7  Aq. 
wild  eombines  with  (NH^J'^SOi  to  form  a  double  sulfate,  used  in  the 
uickel- plating  bath,  for  wliieh  use  it  must  be  free  from  K  or  Na. 

Analytical  Characters.— (1)  Ammonium  sulfhydrate:  black  ppt.; 
lOKoluble  in  excess.  (2)  Potash  or  soda:  apple -green  ppt,.  in  ab- 
^Dce  of  tartaric  acid;  insoluble  in  excess.  (3)  Ammonium  hydroxid; 
apple-green  ppt.;  soluble  in  excess;  forming  a  viob^t  solutionywhich 
<l*?lM>sits  the  apple -green  hydrate,  when  heated  wnth  KHO. 


COBALT. 

Hi/mbol=^Co—Atomk'  wetght=m(0=m.59;  R=b9M)— 8p.gr  = 

^.H.7.  ^ 

Occm-sj  in  combination  with  As  and  S.  Its  salts  are  i-ed  when 
"yJratfd,  and  usually  b!ae  when  anhydrous.  Its  phosphate  is  used 
****  blue  pigment. 

Analytical  Characters. — {1)  Ammonium  sulfhydrate:  black  ppt.; 
i^Mulile  in  excess.  (2)  Potash:  blue  ppt.;  turns  red,  slowly  iu  the 
*^5*"lt  finickly  when  heated;  not  formed  in  the  cold  in  the  presence  of 
^"* salts.  (3)  Ammonium  hydroxid:  blue  ppt.;  turns  red  iu  ab- 
■^•J*^  of  air,  green  in  its  presence. 


2j0 


MANUAL    UF    CHEMISTRY 


VII.     COPPER   GROUP. 


COPPER — MERCURY. 


Each  of  these  elements  forms  two  series  of  componnds.      One 

eoutains  compounds  of  the  bivalent  group  \^^^/ J  or  (Hg2)'',  which 

are  designated  by  the  termination  ous ;  the  other  contains  compounds 
of  single,  bivaieut  atoms  Cu'  or  Hf^'\  w^i^^i  are  designated  by  the 
termination  ic. 


COPPER. 


Sij  m  h  n  J^^  C  u    ( Cnp  r  it  m )  — A  to  m  k   we  ig  /fl 

a 27  {D—Sp} 


1  r  6 3 .  09 )  —  Mole v u  la  r  tv f  ig h  t 
at  1091^  (1996°  F.).\ 

Occurrence. -^It  Is  found  free,  in  (*r3i 
sometimes  of  grea^jize;  also  as  sulfid,  co 
and  bhii^k  ox  id  ;  auS  busie  carbonate,  mt^ 

Properties .  — physical ,  — A  yel  lo  wish  - 


finely  divided  ;  v 
duetor  of  beat  a 
characteristic  odoj 

Chemical, — It 
but,  when  heated 
becomes  coated  wH 
carbon^ 
dissol\'e\it 
HNO3  wi 
tion  o 
and  mo 
format 
quently  with 

Oxids.— I 
—143.2  — is 
or  a  mixtufajof 


malleaule 
eleetriei 


ductile » 
has  a  pf 


r63    (0=16:63.6;    H= 
jr.  =  8.914-8.952— FttSf* 

ils  or  amorphous  massde, 
yrifeH  ;  oxid,  rtifty  ore 

m^al;  dark -brown  when 
tenacious;   a  good  con- 
metallic  taste,  and  a 


unaiteil 
rednesi 
browi 
t  air,  a 
mat  ion 
of  Cu{N4)2a1, 
s  form  with  it 
by  NI 


ordinary  temperatut^; 

CuO.      In  damp  air  it 

id;  a  green  film  of  basic 

asic  chlorid.     Hot  H2SO4 

SO^j.     It   is  dissolved   by 

NO;  and  by  HCl  with  libera* 

^uble  salts,  in  presence  of  air 

0»  in  presence  of  air,  with 


tion 


It   combines   directly   with   CI,    fre- 


It  is  dissolved 
lue  solution, 
t^^ 

xid — Suboxid  or  red  ox  id  of  copper — (CuojO 
bj'\;alciuing  a  mixture  of  (Cu-)Cl3  and  NaaCOa; 
nS  anON^^u.     It  is  a  red  or  yellow  powder;   per- 
manent  in   ftir;    sp\  gr.   5.749-6.093;    fuses   at  a  red   heat;    easily 
reduced  by  (Xor  H.\  Heated  in  air  it  is  converted  into  CuO. 

Cupric  Oxia^^^jmxul  or  black  oxid  of  copper  —  CuO  —  79.6  —  is 
prepared  by  heating  Cu  to  dull  redness  in  air;  or  by  calcining 
CuiNOala;  or  by  prolonged  boiling  of  the  liquid  over  a  precipitate, 
produced  by  heating  a  solution  of  a  cupric  salt,  in  presence  of 
ghicose,  with  KHO.  By  the  last  method  it  is  sometimes  pnnhiced 
in  Tnimmer's  test  for  glucose,  when  an  excessive  quantity  of  CuSOi 
has  been  used. 


\ 


COPPER  251 

It  is  a  black,  or  dark  reddish -brown,  amorphous  solid;  readily 
reduced  by  C,  H,  Na,  or  K  at  comparatively  low  temperatures.  When 
heated  with  organic  substances,  it  gives  up  its  O,  converting  the  C 
into  CO2,  and  the  H  into  H2O:  C2H60+6CuO=6Cu+2C02+3H20; 
a  property  which  renders  it  valuable  in  organic  analysis,  as  by  heat- 
ing a  known  weight  of  organic  substance  with  CuO,  and  weighing 
the  amount  of  CO2  and  H2O  produced,  the  percentage  of  C  and  H 
may  be  obtained.     It  dissolves  in  acids  with  formation  of  salts. 

Hydroxids.— Cuprous  Hydroxid—(Cu)2H202(f)— 160.4  (f)— is 
formed  as  a  yellow  or  red  powder  when  mixed  solutions  of  CuSO* 
and  KHO  are  heated  in  presence  of  glucose.  By  boiling  the  solution 
it  is  rapidly  dehydrated  with  formation  of  (Cu2)0. 

Cupric  Hydroxid — CUH2O2 — 97.6 — is  formed  by  the  action  of 
KHO  upon  solution  of  CUSO4,  in  absence  of  reducing  agents  and  in 
the  cold.  It  is  a  bluish,  amorphous  powder:  very  unstable,  and 
readily  dehydrated,  with  formation  of  CuO. 

Sulfids. —  Cuprous  Sulfid — Subsulfid  or  protosulfid  of  copper — 
CU2S — 159.2 — occurs  in  nature  as  copper  glance  or  chalcosine,  and  in 
many  double  sulfids,  pyrites. 

Cupric  Sulfid — CuS — 95,6 — is  formed  by  the  action  of  H2S,  or  of 
NH4HS,  on  solutions  of  cupric  salts.  It  is  almost  black  when  moist, 
greenish -brown  when  dry.  Hot  HNO3  oxidizes  it  to  CUSO4;  hot 
HCl  converts  it  into  CuCk,  with  separation  of  S,  and  formation  of 
H28.  It  is  sparingly  soluble  in  NH4HS,  its  solubility  being  increased 
by  the  presence  of  organic  matter. 

Chlorids. —  Cuprous  Chlorid — Subchlorid  or  protochlond — (CU2) 
CI2 — 198.1 — is  prepared  by  heating  Cu  with  one  of  the  chlorids  of 
Hg;  by  dissolving  (Cu2)0  in  HCl,  without  contact  of  air;  or  by  the 
action  of  reducing  agents  on  solutions  of  CUCI2.  It  is  a  heavy,  white 
powder;  turns  violet  and  blue  by  exposure  to  light;  soluble  in  HCl; 
insoluble  iu  H2O.  It  forms  a  crystallizable  compound  with  CO;  and 
its  solution  in  HCl  is  used  in  analysis  to  absorb  that  gas. 

Cupric  Chlorid — Chlorid  or  deutochlorid — CuCh — 134.5 — is  formed 
by  dissolving  Cu  in  aqua  regia.  If  the  Cu  be  in  excess,  it  reduces 
OuCh  to  (Cu2)Cl2.  It  crystallizes  in  bluish-green,  rhombic  prisms 
with  2  Aq;  deliquescent;   very  soluble  in  H2O  and  in  alcohol. 

Cupric  Nitrate — Cu(N03)2 — 187.6 — is  formed  by  dissolving  Cu, 
CuO,  or  CuCOa  in  HNO3.  It  crystallizes  at  20°-25°  (68°-77°  P.) 
with  3  Aq;  below  20°  (68°  F.)  with  6  Aq,  forming  blue,  deliquescent 
needles.     Strongly  heated,  it  is  converted  into  CuO. 

Cupric  Sulfate — Blue  vitriol — Blue  stone — Cupri  sulfas  (U.  S.; 
Br.)— CuS04+5Aq— 159.6+90— is  prepared:  (1)  by  roasting  CuS; 
(2)  from  the  water  of  copper  mines;  (3)  by  exposing  Cu,  moistened 
with  dilute  H2SO4,  to  air;    (4)  by  heating  Cu  with  H2SO4. 


CHEMISTRY 

As  ordinarily  erystallizeil,  it  is  in  fine,  blue,  oblique  prisms;  solu- 
ble ill  H2O;  insoluble  in  aleoliol;  effloreseent  in  dry  air  at  15"^  (59^ 
F.),  losing  2  Aq.  At  100°  (212^^  F.)  it  still  rftains  1  Aq,  which  it 
loses  at  230^  (446*^  F.),  leaving  a  whitt%  amorpbous  powder  of  the 
anhydrous  salt,  which,  on  taking  up  H2O,  resumes  its  bine  color. 
Its  solutions  are  bine,  acid»  styptie,  and  metallic  in  taste. 

When  NII^HO  is  added  to  a  solution  of  CuS04t  ^  IVlnish- white 
precipitate  falls,  which  redissolves  in  excess  of  the  alkali,  to  form  a 
deep  blue  solution.  Strong  alcohol  floated  over  the  surface  of  thrs^ 
solution  separates  long,  right  rhombic  prisms,  having  the  (composi- 
tion CnS04,4Nn:t+Fl20,  which  are  very  soluble  in  HjO.  This  solu- 
tion constitutes  ammonio-sulfate  of  copper  or  aqua  sapphiritia. 

Cupric  Arsenite — Scheele's  green  —  Mineral  green — is  a  mix- 
ture of  cupric  arsenite,  HCuAsOa,  and  hydroxid;  prepared  by  adding 
potassium  arsenite  to  sohition  of  CuSOj.  It  is  a  grass -green  powder,, 
insoluble  in  H^O;  soluble  in  NH4HO,  or  in  acids.  Exceedingly 
poisonous. 

Schweinfurt  Green  —  Mitis  green  or  Paris  green  —  is  the  most 
frequently  used,  and  the  most  dangerous  of  the  cnpro -arsenical  pig- 
ments* Ik  is  prepared  by  adding  a  thin  paste  of  neutral  cupric 
acetate  with  Hi^O  to  a  boiling  solution  of  arsenous  acid,  and  con- 
tinuing the  boiling  during  a  further  addition  of  acetic  acid.  It  is 
an  insoluble,  green,  crystalline  powder,  having  the  composition 
(C2Ha02)2Cn+3Cu(AsOo)2,  and  is  therefore  cupric  aceto-metarsenite. 
It  is  decomposed  by  prolouged  boiling  in  H-jO,  by  aqueous  sohitions 
of  the  alkalies,  and  by  the  mineral  acids. 

Carbonates. — The  existence  of  cuprous  carbonate  is  doubt fuL 
Cupric  carbonate — CnCO.i  —  exists  in  nature,  but  has  not  been  ob- 
tained artificially.  Dicupric  carbonate — CnC0,4,CuHiO2^ exists  in 
nature  as  malachite.  When  a  solution  of  a  cupric  salt  is  decomposed 
by  an  alkaline  carbonate,  a  bluish  precipitate,  having  the  composition 
CnC03,CuILj02+ H^jO,  is  formed,  which,  on  drying,  loses  HiiO,  nnd 
becomes  greeny  it  is  used  as  a  pigment  under  the  nanic  mineral 
green.  Tricupric  carbonate  —SeHquiearhfrnate  of  eoppfv —  2  ( CnCOa ) , 
CuH202^ — exists  in  nature  as  a  b!ne  mineral,  called  azurite  or  moun- 
tain blue,  and  is  prepared  by  a  secret  process  for  use  as  a  pigment 
known  as  blue  ash. 

Acetates. —  Cupric  Acetate — Dmcffate  — CnjstaU  af  Ymus — Cupri 
acetas  (U.  S.)—Cn(C-H302)-+Aq— 181.6+18— is  formed  when  CnO 
or  verdigris  is  dissolved  in  acetic  acid;  or  by  decomposition  of  a 
solution  of  CnSOi  by  Pb(C2Ha02)2.  It  crystallizes  in  large,  bhiish- 
green  prisms,  w^hich  lose  their  Aq  at  140'*  (284''F.).  At  24O°-2G0° 
(464*^-500*^  P.)  they  are  decomposed  with  liberation  of  glacial  acetic- 
acid. 


COPPEB 


253 


Basic  Acetates. — Verdigris— U  a  substance  prepared  by  exposing 
to  air  piles  composed  of  alternate  layers  of  grape -skins  and  plates 
of  copper,  and  removing  the  bluish -green  coating  from  the  copper. 
It  is  a  miKture,  in  varying  proportions,  of  three  different  sub- 
stanees:  ( C2H:jO^)jCu2H202+5Aq;  [(t^H30j)2Cu]2,CuH202+5Aq;  and 
(C2H:,0::)2Cu,2(Cun,02). 

Analytical  Characters. —  Cuprous — are  very  unstable  and  readily 
converted  into  cnpric  compounds.  (1)  Potash:  white  ppt.;  turning 
brownish.  (2)  Ammonium  hydroxid,  in  absence  of  air:  a  colorless 
liquid;  turns  blue  in  air. 

CUPRIC  —  are  wliite  when  anhydrous;  when  soluble  in  H-^O  they 
form  blue  or  green,  acid  solutions.  (1)  Hydrogen  sulfid:  black  ppt.^ 
insoluble  in  KHS  or  NaH*S;  sparingly  soluble  in  NH4HS;  soluble  in 
hot  concentrated  UNOu  and  in  KCN.  {2}  Alkaline  siilf hydrates: 
same  as  H2S,  (3)  Potash  or  soda:  pale  blue  ppt.;  insoluble  in 
excess.  If  the  solution  be  heated  over  the  ppt*,  the  latter  contracts 
and  turns  black.  (4)  Ammonium  hydroxid,  in  small  quantity:  pale 
blue  ppt.;  in  larger  quaotity:  deep  blue  solution,  (5)  Potassium  or 
sodium  carbonate:  greenish- blue  ppt.;  insoluble  in  excess;  turning 
black  when  the  liquid  is  boiled.  (6)  Ammonium  carbonate:  pale 
bine  ppt.;  soluble  with  deep-blue  color  in  excess.  (7)  Potassium 
cyanid:  greenish -yellow  ppt.;  soluble  in  excess.  (8)  Potassium  fer- 
rocyanid:  chestnut* brown  ppt.;  insoluble  in  weak  acids;  decolorized 
by  KHO.     C9)  Iron  is  coated  with  metaliie  Cn. 

Action  on  the  Economy, — ^The  opinion,  formerly  universal  among 
toxicologists,  tliat  all  the  compounds  of  copper  are  poisonous,  has 
been  much  modified  by  later  researches.  Certain  of  the  copper 
compounds,  such  as  the  sulfate,  having  a  tendency  to  combine  with 
protein  and  other  animal  substances,  produce  synrptoms  of  irrita- 
tion by  their  direct  local  action,  when  brought  in  contact  with  the 

^Crastrc  or  intestinal  mucous  membrane.     One  of  the  eharaeteristic 
Bymptonis  oP  such  irritation  is  the  vomiting  of  a  greenish  matter, 

'which  develops  a  blue  color  upon  the  addition  of  NH4HO. 

Cases  are  not  wanting  in  which  severe  illness,  and  even  death,  has 
followed  the  use  of  food  which  has  been  in  contact  with  imperfectly 
tinned  copper  vessels.  Cases  in  which  nervous  and  other  symptoms 
referable  to  a  truly  poisonous  action  have  occurred.  As,  however,  it 
has  also  been  shown  that  non- irritant,  pure  copper  compounds  may 
be  taken  in  considerable  doses  with  impunity,  it  appears  at  least 
probable  that  the  poisonous  action  attributed  to  copper  is  due  to 
other  substances.  The  tin  and  solder  used  in  the  manufacture  of 
copper  utensils  contain  lead,  and  in  some  cases  of  so-called  copper- 

*poisoning,   the  symptoms  have  been  such  as  are  as  consistent  wuth 
lead- poisoning  as  with  copper -poisoning.     Copper  is  also  notoriously 


2rA  MANUAL    OF    CHEMISTRY 

liable  to  contamination  with  arsenic,  and  it  is  by  no  means  im- 
probable that  componnds  of  that  element  are  the  active  poisonous 
agents  in  some  cases  of  snpposed  copper-intoxication.  Nor  is  it 
improbable  that  articles  of  food  allowed  to  remain  exposed  to  air  in 
copper  vessels  should  undergo  those  peculiar  changes  which  result 
in  the  formation  of  poisonous  substances,  such  as  the  sausage-  or 
cheese -poisons,  or  the  ptomains. 

The  treatment,  when  irritant  copper  compounds  have  been  taken, 
should  consist  in  the  administration  of  white  of  egg  or  of  milk,  with 
whose  proteins  an  inert  compound  is  formed  by  the  copper  salt. 
If  vomiting  do  not  occur  spontaneously,  it  should  be  induced  by  the 
usual  methods. 

The  detection  of  copper  in  the  viscera  after  death  is  not  without 
interest,  especially  if  arsenic  have  been  found,  in  which  case  its 
discovery  or  non- discovery  enables  us  to  diflferentiate  between  poison- 
ing by  the  arsenical  greens,  and  that  by  other  arsenical  compounds. 
The  detection  of  mere  traces  of  copper  is  of  no  significance,  because, 
although  copper  is  not  a  physiological  constituent  of  the  body,  it  is 
almost  invariably  present,  having  been  taken  with  the  food. 

Pickles  and  canned  vegetables  are  sometimes  intentionally  greened 
by  the  addition  of  copper;  this  fraud  is  readily  detected  by  inserting 
a  large  needle  into  the  pickle  or  other  vegetable;  if  copper  be  present 
the  steel  will  be  found  to  be  coated  with  copper  after  half  an  hour's 
contact. 

MERCURY. 

Symbol=Rg  (Hydrargyrum)-' Atomic  weight=200  (0=16:200.3; 
R=l:  198  J)— Molecular  tveight=19S.7—8p.  gr.  of  liquid=lS,59e  ;  of 
vapor=e.97— Fuses  at  —38.8°  (—37.9°  F.)— Boils  at  358°  (676.4** 
F.). 

Occurrence. — Chiefly  as  cinnabar  (HgS);  also  in  small  quantity 
free  and  as  chlorid. 

Preparation. — The  commercial  product  is  usually  obtained  by 
simple  distillation  in  a  current  of  air:  HgS+02=Hg+S02.  If  re- 
quired pure,  it  must  be  freed  from  other  metals  by  distillation,  and 
agitation  of  the  redistilled  product  with  mercurous  nitrate  solution, 
solution  of  Fe2Cle,  or  dilute  HNO3. 

Properties. — Physical, — A  bright  metallic  liquid  ;  volatile  at  all 
temperatures.  Crystallizes  in  octahedra  of  sp.  gr.  14.0.  When  pure, 
it  rolls  over  a  smooth  surface  in  round  drops.  The  formation  of  tear- 
shaped  drops  indicates  the  presence  of  impurities. 

Chemical. — If  pure,  it  is  not  altered  by  air  at  the  ordinary  tem- 
perature, but,  if  contaminated  with  foreign  metals,  its  surface  be- 
comes dimmed.     Heated  in  air,  it  is  oxidized  superficially  to  HgO.    It 


MEBCUKY 


255 


!oes  not  decompose  IIsO.  It  combines  directly  with  CI,  Br,  I,  and  S. 
It  alloys  readily  with  most  metals  to  form  amalgams.  It  amalga- 
mates with  Fe  and  Pt  only  with  difficulty.  Hot»  concentrated,  H2SO4 
dissolves  it,  with  evolution  of  SO2,  and  formation  of  HgSO^.  It  dis- 
solves in  cold  HNO3,  with  formation  of  a  nitrate. 

Elementary  mercury  is  insoluble  in  IIl»0,  and  probably  in  the 
digestive  liquids.  It  enters,  however,  into  the  formation  of  three 
medicinal  agents:  hydrargyrum  cum  creta  (U.  S.;  Br.);  massa  hy- 
drargyri  (U.  Sj^pilula  hydrargyri  (BrJ;  and  unguentum  hydrar- 
gyri  (U.  S,;  Br.),  all  of  which  owe  their  efficacy,  not  to  the  metal 
itself,  but  to  a  certain  proportion  of  oxid,  produced  during  their 
manufacture.  The  fact  that  blue  mass  is  more  active  than  mercury 
with  chalk  is  due  to  the  greater  proportion  of  oxid  coniained  in  the 
former.  It  is  also  probable  that  absorption  of  vapor  of  Hg  by  cuta- 
neous surfaces  is  attended  by  its  coo  version  into  HgCL>. 

Oadds. — Mercurous  Oxid^Protoxid  or  hhtek  oxid  of  mervitri/ — 
(Hg^)O — 416.6 — is  obtained  by  adding  a  solution  of  (IIg2)(N03)2  to 
an  ezcesa  of  solution  of  KHO.  It  is  a  brownish  l>laek,  tasteless 
powder;  very  prone  to  decomposition  into  HgO  and  Tig.  It  is  con- 
verted into  (Hg:>)Cl2  by  HCl;  and  by  other  acids  into  the  corre- 
sponding mercurous  salts. 

It  is  formed  l*y  the  action  of  CHH2O2  on  mercurous  compounds, 
aud  exists  in  black  wash. 

Mercuric  Oxid -^ Red ^  or  hhituid  of  ftterenrif  —  Hydrargyri  oxi- 
<lum  flavum  (U.S.;  Br.) — Hydrargyri  oxidum  rubrum  (U.S.;  Br.) 
'  H\*i> — 21Ck^  —  is  prepared  by  two  methods:  (1)  l>y  calcininjj  Hg- 
(^0;i)'^,  as  long  as  brown  fumes  are  given  off  {Hifdr.  oritK  rnhr.)i 
oti  (2)  by  precipitating  a  sohiHon  of  a  mercnric  salt  by  excess  of 
KHO  (Hydr,  oxid.  ffaviim).  Tlie  products  obtained,  although  the 
same  in  composition,  differ  in  pliysical  (characters  and  in  the  activity 
**f  Hieir  chemical  actions.  That  obtained  by  (1)  is  red  and  crystalline; 
t*iat  obtained  by  (2)  is  yellow  aud  amorphous.  The  latter  is  much 
the  uiot*e  active  in  its  chemical  and  medic inal  actions. 

It  is  very  sparingly  soluble  in  II2O,  the  solution  having  an  alka- 
1^^  !i*action,  aud  a  metallic  taste.  It  exists  both  in  solution  ami 
*^  suspension  in  yellow  wash*  prepared  by  the  action  of  CaH20:i 
^^  a  mercuric  compound. 

ExiK)sed  to  light  and  air,  it  turns  black,  more  rapidly  in  presence 
*^^  ofganie  matter,  giving  off  0,  and  liberating  Hg:HgO=^Hg-f  O. 
'Meeomposes  the  cblorids  of  many  metallic  elements  in  solution » 
^^*h  fonnation  of  a  metallic  oxid  and  mercuric  oxychlorids.  It 
^'^'uhiues  with  alkaline  chlorids  to  form  soluble  double  chlorids, 
^ftll^l  chloromercurates  or  chlorhydrargyrates ;  and  forms  similar 
^^iftpouuds  with  alkaline  iodids  and  bromids. 


256 


iNUAL    OF    CHEMISTRY 


Sulfids*— Mercurous  Sulfid— (Hg2)  S — 432.6 — a  veiy  unstable 
compound,  foniied  by  the  action  of  H-jS  on  mercnrons  salts. 

Mercuric  Sulfld  —  Red  sulfid  of  mercury  —  Cinnabar— Vcrmil' 
ion — Hydrargyri  sulfidum  rubrum  (U.  S.)~HgS  —  232.3 — exists 
in  nature  in  amorphous  red  masses,  or  in  red  crystals,  and  is  the 
chief  ore  of  Hg*  If  Hgr  and  S  be  ground  up  together  in  the  cold, 
or  if  a  solution  of  a  mercuric  salt  be  completely  decomposed  by 
H2S,  a  black  sulfid  is  obtained,  which  is  the  i^thiops  mineralis  of 
the  older  pharmacists. 

A  red  sulfid  is  obtained  for  use  as  a  pigment  (vermilion),  by 
agitating  for  some  hours  at  GO'"'  (140'^  P.)  a  mixture  of  Hg,  S,  KHO, 
and  H:iO.  It  is  a  fine,  red  powder,  which  turns  brown,  and  finally 
black,  when  heated.  Heated  in  air,  it  burns  to  8O2  and  Hg,  It 
is  decomposed  by  strong  H-SO4,  but  not  by  HXOa  or  IICK 

Chlorids. —  Mercurous  Chlorid — Proforhlorid  or  ^nild  chlorkl  of 
wpvcnnj  —  Calomel  —  Hydrarg3rri  chloridum  mite  (U.  H.)  —  Hydrar- 
gyri subchloridum  (BrJ  — (Hg^)Cl2 — 471,5— is  now  princiimlly 
obtained  by  nnitual  decomposition  of  NaCl  and  (Hg2)804.  Mer* 
curie  sulfate  is  fiirst  obtained  by  beating  together  2  pts.  Hg  and 
3  pts.  H2SO4;  the  product  is  then  caused  to  combine  with  a  quantity 
of  Fig  equal  to  that  first  used,  to  form  (Hg*j)S04;  which  is  then  mixed 
with  dry  NaC!,  and  the  mixture  heated  in  glass  vessels,  couueeted  with 
condensing  chambers;  2NaCl  +{Hg2)S0j  =  Na2S04  +(Hg2)Cl2. 

In  practice,  varying  quantities  of  HgCIs  are  also  formed,  and 
must  l>e  removed  from  the  product  by  washing  with  boiled,  distilled 
H2O,  uutil  the  washings  no  longer  precipitate  with  NII^FIO,  The 
presence  of  HgCb  in  calomel  may  be  detect ed  by  the  formaiiou  of  a 
black  stain  upon  a  bright  copper  surface,  immersed  in  the  calomel, 
moistened  with  alcohol;  or  by  the  production  of  a  black  color  by  H2S 
in  H2O  which  has  been  in  contact  with  and  filtered  from  calomel  so 
contaniinated. 

Calomel  is  also  formed  in  a  number  of  other  reactions:  (1)  By  the 
action  of  CI  upon  excess  of  Hg.  (2)  By  the  action  of  Hg  upon 
Pe2Clfl.  (3)  By  the  action  of  HCl,  or  of  a  chlorid,  upon  (Hg2)0,  or 
upon  a  mercurous  salt.  (2)  By  the  action  of  reducing  agents,  in- 
cluding Hg,  upon  HgCU*. 

Calomel  crystallizes  in  nature,  and,  when  sublimed,  in  quadratio 
prisms.  When  precipitated  it  is  deposited  as  a  heavy,  amorphous, 
white  powder,  faintly  yellowish*  and  producing  a  yellowish  mark  when 
rubbed  upon  a  dark  surface.  It  sublimes,  without  fusing,  between 
420''  and  mf  (78S°-932°  P.),  is  insoluble  in  cold  H2O  and  in  alco- 
hol; soluble  in  boiling  H2O  to  the  extent  of  1  part  in  12,000.  When 
boiled  with  H^O  for  some  time,  it  suffers  partial  decomposition,  Hg  is 
deposited  and  HgCla  dissolves. 


4 
4 


MERCUBV 


2r)7 


I 


p 


tbotigh  Hg:2Cl2  is  insoluble  iu  H2O,  in  dilute  HC!  and  in  pepsin 
^olutioti,  it  is  dissolved  at  tlie  body  temperature  iu  an  aqueous  solu- 
tion of  pepsin  acidulated  with  HCK 

When  exposed  to  lights  ealomel  becomes  yellow,  theu  gray,  owiug 
4o  partial  deeom position,  witli   liberation  of    Hg   and    fonnation  of 
UgCh:  (Hir2)Cl2=ng+HgCI>.     It  is  converted  into  HgCb  by  CI  or 
aqua  r€gia:  (Hg2)Cl2+Cl2=2HgCl2,     In  the  presence  of  H2O,  I  con- 
verts it  into  a  mixture  of  HgCLj  and  Hgh:  (Hg2)Cl2+I>=HgCl2+ 
Hgla.     It  is  also  converted  into  Ht,^Cl2  hy  HCl  and  by  alkaline  ehlor- 
ids:  (Hg2)Cl2^HgCl2+Hg.     This  change  occurs  in  the  stomach  when 
calomel  is  taken  iuterually,  and  that  to  such  an  extent  when  large 
quantities  of  NaCl  are  taken  with  tlie  food,  that  calomel  eauuot  be  used 
iQ  naval  practice  as  it  may  be  with  patients  who  d<»  !iot  snbj^ist  npf»n 
salt  provisions.     It  is  converted  by  KI  into  (Hg2)l2:    (Hg2)Cl2+2KI 
=2KCl+(Hg2)l2;   which  is  then  decomposed  by  excess  of  KI  into 
II g  and  Hgl'ii  the  latter  dissolvitjg:    (IIg2)Iir=Hg+IIgl2.     Solutions 
of  the  sulfates  of   Na,   K  aod   NHi  dissolve  notable  quantities  of 
(Hgi)Cl2*     The  hydroxids  and  carbonates  of  K  and  Na  decompose  it 
with  formation   of    (IIg2)0:    (Hg2)CU  +  Na2C03={Hg2)0  + CO2+ 
2NaCl;   and  the  (Hg2)0  so  formed  is  deeomposed  into  HgO  and  Hg, 
U  alkaline  chlorids  be  also  present,  they  react  upon  the  HgO  so  pro- 
duced, with  formation  of  HgC!2. 

Mercuric  Chlorid — Perrhlorid  or  hifhlond  of  mereunj — Corrosive 
sublimate — Hydrargyri  chloridum  corrosivum  (U.  S.);  Hydrargyri 
pcfchloridum  ( Br. ) — HgCl2— 271.2 — ^is  prepared  by  heating  a  mixture 
«f  5  pts.  dry  HgSOi  with  5  pts,  dry  NaCl,  aiul  I  pt.  Mn02  in  a  glass 
▼«i8el  communicating  with  a  condensing  clianiber. 

It  crystallizes  by  Biibliinatiou  in  octahedra^  and  by  evaporation  of 
it«  solutions  in  flattened,  right  rhombic  prisms;  fuses  at  265*^'  (500'^ 
F.),  and  boils  at  about  295°  (SG-l"  PJ;  soluble  in  H2O  and  in 
alcohol;  very  soluble  in  hot  HCl,  the  solution  gctatiuizing  on  cooling, 
lu  solutions  have  a  disagreeable,  aeid,  styptic  taste,  and  are  highly 
poiRoaous.  Although  HgClj  is  heavier  than  water  (sp.  gr.=5.4) 
.tkeu  the  crystalline  powder  is  thrown  upon  water  a  portion  floats 
some  time. 

It  is  easily  reduced  to(Hg2)Cl2  and  Hg,  and  its  aqueous  solutions 
*r»!  so  decomposed  when  exposed  to  light;  a  change  which  is  retarded 
^  the  presence  of  NaCl.  Heated  with  Hg,  it  is  converted  into 
'Bg5)Cl2,  When  dry  HgCla^  or  its  solution,  is  heated  with  Zn,  Cd, 
Ni|  Fe,  Pb,  Cu,  or  Bi,  those  elements  remove  part  or  all  of  its  CI, 
*ith  separation  of  (Hg2)Cl2  or  Hg.  Its  solution  is  deconi posed  by 
B38,  with  separation  of  a  yellow  sulfochlorid,  which,  with  au  excess 
^f  the  gas,  is  converted  into  black  HgS.  It  is  soluble  without  de- 
*«njpo8ition  in  BSOu  HNO3,  and  HCL     It  is  decomposed  by  KHO  or 


258 


MANUAl.    OF    CHEMISTRY 


an      ' 


NaHO,  with  separation  of  a  brown  oxyehlorid  if  the  alkaline 
hydroxid  be  in  limited  quantity;  or  of  the  orange -colored  HgO  if  it 
be  in  excess.  A  similar  decomposition  is  elfectcd  by  CaH^Oo  anf 
MgH202;  which  does  not,  however,  take  place  in  presence  of  an" 
alkaline  chlorid,  or  of  certain  organic  mattei^i*,  such  as  sugar  and 
gnra.  Many  organic  siibstaiices  decompose  it  into  (Hg2)Cl'2  or  Hg| 
especially  under  the  influence  of  sunlight.  Thus  in  sunlight  it  is." 
reduced  by  oxalic  acid,  which  is  itself  oxidized  to  carbon  dioxid: 
2HgCl2+C204H3— Hg2Cl2+2C02+2HCl.  For  this  reason  it  behaves 
as  au  oxidant :  2HgCl2+H20— Hg2Cl2+2HCl+0.  Albumen  formfi 
with  it  a  white  precipitate,  which  is  insoluble  in  H^O,  but  soluble  in 
an  excess  of  fluid  albumen  and  in  solutions  of  alkaline  ehlorids.  It 
readily  combines  with  metallic  ehlorids,  to  form  solulile  double 
ehlorids,  called  chloromercurates  or  chlorhydrargyrates.  One  of 
these,  obtained  in  flattened,  rhombic  prisms,  by  the  cooling  of  a  boil* 
iug  solution  of  HgCh  and  NH^Ci,  has  the  composition  Ilg(NH4)2* 
Cla+Aq,  and  was  formerly  known  as  sal  alemhrofh  or  sal  sapientiw. 
It  is  a  very  energetic  germicide. 

Mercurammonium  Chlorid^ — Merrnry  ckloramidid — Infusihlf  white 
preripiiaff^ — Ammonhded  mercury  —  Hydrargyrurn  ammoniatum  (U. 
8.;  Br.) — NH^IIgCl — ^251.8 — is  prepared  by  adding  a  slight  excess  of 
NIIjIIO  to  a  solution  of  HgClj.  It  is  a  white  powder,  insoluble  in 
alcohol,  ether,  and  cold  EL^O:  decomposed  by  hot  H2O,  with  separa- 
tion  of  a  heavy,  yellow  powder.  It  is  entirely  volatile,  without 
fasten .  The  f us ihU  white  precipitate  is  formed  in  small  crystals  when 
a  solution  containing  equal  parts  of  HgGl^  and  NH^Ol  is  decomposed 
by  NaiCOa.     It  is  inercurdiammonium  chlorid,  XH2Hg,NIl4Cl2. 

Iodids,^"Mercurous  lodid — Protoiodid  or  yellow  iodid  —  Hydrar- 
gyri  iodidum  viride  (U,  S,;  Br,)^ — Hg2l2 — 654.3^ — is  prepared  by 
grinding  together  200  pts,  Hg  and  127  pts.  I  with  a  little  alcohol, 
until  a  green  paste  is  formed.  It  is  a  greenish -yellow,  amorphous 
powder,  insoluble  in  H2O  and  in  alcohol.  When  heated,  it  turns 
brown,  and  volatilizes  completely.  When  exposed  to  light,  or  even 
after  a  time  m  the  dark,  it  is  decomposed  into  Hgia  and  Hg.  The 
same  deeomposition  is  brought  about  instantly  by  KI;  more  slowly 
by  solutions  of  alkaline  cblorids^  and  by  HCl  when  heated.  NHifiO 
dissolves  it  with  separation  of  a  gray  precipitate. 

Mercuric  Iodid— Binimiid  or  red  iodid — Hydrargyri  iodid um  ru^ 
brum  (U.  S.;  Br.) — Hgl2 — 454 — is  obtained  by  double  decompositioi] 
between  HgOl^  and  KI,  care  being  had  to  avoid  too  great  au  excess 
the  alkaline  iodid,  that  the  soluble  potassium  iodhydrargyrate  rafl 
not  be  formed. 

It  is  sparingly  soluble  in  H2O;  but  forms  colorless  solutions  wit 
alcohol.     It  dissolves  readily  in  many  dilute  acids,  and  in  solutions  or 


^ 


MERCITRY 


259 


araraoniacal  salts,  alkaline  elilorids,  and  mercuric  salts;  and  in  solu- 
tions  of  alkaiiae  iodids.  Iron  and  copper  convert  it  into  (H^s)!^* 
then  into  Hg.  The  hydroxids  of  K  and  Na  decompose  it  into  oxid  or 
oxyiodid,  and  combine  with  another  portion  to  form  iodhydrargyrates, 
which  dissolve,  NH4HO  separates  from  its  solution  a  brown  powder, 
and  forms  a  yellow  solution,  which  deposits  white  fioeks* 

Mercuric  Cyanid  —  Hydrargyri  cyanidum  (U.  S.) — HgfCN)2 — 
252*3 — is  best  prepared  by  heating  together,  for  a  quarter  of  an  hour^ 
potassium  fennx^yanid,  1  pt. ;  ngSOi,  2  pts.;  and  H20»  8  pts,  It 
<-r>*stallizes  in  qnadrangular  prisms;  soluble  in  8  pts.  of  H2O,  much 
less  soluble  in  alcohol ;  highly  poisonous.  When  heated  dry  it 
blackens,  and  is  decomposed  into  (CN)2and  Ilg;  if  heated  in  pres* 
cnce  of  HmO  it  yields  IICN,  Jig,  CO-,  and  KHa.  Hot  concentrated 
TlSOi,  and  HCl,  HBr,  III,  and  11-8  in  the  cold  decompose  it,  with 
liberation  of  IICN.     It  is  not  decomposed  by  Hlknlies. 

Nitrates. — Thei^  exist,  besides  the  normal  nitrates;  (ng3}(NO:t)2, 

Hg(XO:i)v%  three  basic  mercnrous  nitrates,  three  basic  mercnric 

ites*  and  a  mercnroso-men^uric  nitrate, 

Mercurous   Nitrate— (Ilgs)  (X03)2+2Aq—524.G+36— is   formed 

when  excess  of  Hg  is  digested  with  HNOa*  diluted  with  %  vol.  H2O; 

until  short,  prismatic  crystals  separate. 

It  effloresces  in  air;  fuses  at  70°  (158°  F.);  dissolves  in  a  small 
quantity  of  hot  HjO,  but  with  a  larger  quantity  is  decomposed  with 
separation  of  the  vellow,  basic  trimercuric  nitrate, HgCNOa) 2, 2HgO+ 
Aq.  ^ 

Dimercurous  Nitrate  — (Hg^JCXOa)-:,  Hg'iO+Aq— 941.2+18  — is 
formed  by  acting  upon  the  preceding  salt  with  cold  Ht-0  until  it  turns 
l^mon -yellow;  or  by  extracting  with  cold  H-jO  the  residne  of  eviipo- 
fation  of  the  product  obtained  by  acting  upon  excess  of  Hg  with  con- 
centrated HNO3. 

Trimcrcurous  Nitrate  — {Hg2)2(NO:f ) 4,  Hg^O+SAq —1465.8+54 
Ha  obtained  in  large,  rhombic  prisms,  when  excess  of  Hg  is  boiled 
^th  HNO3,  diluted  with  6  pts,  H2O,  for  5^  hours,  the  loss  by  evap- 
^Wion  being  made  up  from  time  to  time. 

Mercuric  Nitrate— Hg( NO3) 2— 324.3— is  formed  when  Hg  or  HgO 
^  disBolved  in  excess  of  HNO3,  and  the  solution  evaporated  at  a 
B^tle  heat.  A  sjTupy  liquid  is  obtained,  which,  over  quicklime,  de- 
\m\ii  large,  deliquescent  crystals,  having  the  composition  2[Hg- 
kWOilJ+Aq,  while  there  remains  an  uncrystallizable  liquid,  Hg- 
^S0,)i+2Aq. 

This  Rait  is  soluble  in  H2O,  and  exists  in  the  Liq,  hydrargyri  ni- 
[|^»ti8  (U.  S.),  Liq.  hydrargyri  nitratis  acidus  (BrJ;  in  the  voUi- 
*tHo  standard  solution  used  in  iJf'hig's  process  for  urea;  and  prob- 
•My  in  ctYriwf  oinimf^ni^Vng.  hydrar.  nitratis  (U*  8,;  Br.), 


260 


MANUAL    OF    CaEMISTR^ 


Dimercuric  Nitrate^ Kg (X03)j,  H^+Aq—540,6-^is  formed 
M'lieii  IlgO  is  dissolved  to  stituratioD  iu  liot  HNOa,  diluted  with  1  vol. 
HuO;  aud  crystallizes  on  eooliug.  It  is  decomposed  by  H2O  into 
trimcrcuric  nitrate.  Hg(N03)2t  2HgO,  and  lIg{N0a)2. 

Hexamercuric  Nitrate — Hg(N03)2,  5HgO~  1405.8 — m  formed  aa! 
a  red  powder,  by  the  action  of  H2O  on  tri mercuric  nitrate. 

Sulfates. — Mercurous  Sulfate— (PIg2) SO* — 495.4 — is  a  white, 
erj^stallini:  powder,  formed  by  gently  lieatiug  togetlier  2  pts.  llg  and 
3  pts.  H'2804,  and  eausing  the  product  to  combine  with  2  pts.  H^'. 
liuated  with  XaCl  it  forms  {fIg;>)Cl2. 

Mercuric  Sulfate—Hydrargyri  sulfas  (BrJ—HgSO^— 296.3— id?.] 
obtained  by  heating  together  H^g  and  HaSO*,  or  Hg,  H2SOi,  and 
HNO3.  It  is  a  white,  crystalline,  anhydrous  powder^  whieli,  on  con- 
tact with  11^0,  is  decomposed  with  formation  of  trimercuric  sulfate, 
llgSOi,  211gO;  a  yellow,  insoluble  powder,  known  as  turpcth  min- 
eral—Hydrargyri  subsulfas  flavus  (U.  Sj. 

Analytical  Characters,  —  Mercurous.— (1)  Hydrochloric  acid: 
white  ppt-;  insoluble  in  H2O  and  in  acids;  turns  black  with  XIUHO; 
when  boiied  with  HCI»  deposits  Hg,  while  HgCI-i  dissolves.  (2)  Hy- 
drui^eo  sulfld:  black  ppt,;  insoluble  in  alkaline  snltliydrates,  in  dilute 
acids,  and  in  KCN;  partly  soluble  in  boiling  HNOj,  (3)  Potash: 
bhick  ppt.;  insoluble  in  excess,  (4)  Potassium  iodid:  greenish  ppt.; 
converted  by  excess  into  Hg,  which  is  deposited,  and  Hgis,  which  dis" 
solves. 

Mercuric,^ (1)  Hydrogen  sulfid:  black  ppt.  If  the  reagent  be 
slowly  added,  the  ppt.  is  first  white,  then  orange*  finally  black,  (2) 
Anmionium  snlf hydrate;  black  ppt.;  insoluble  in  excess,  except  in 
the  presence  of  organic  matter.  (3)  Potash  or  soda:  yellow  ppt.i 
insoluble  in  excess.  (4)  Ammonium  hydroxid;  white  ppt.;  soluble  in 
great  excess  and  in  solutions  of  NH4  salts.  (5)  Potassium  carbonate: 
red  ppt.  (6)  Potassium  iodid  r  yellow  ppt.,  rapidly  turning  to  sab 
moil  color,  then  to  red;  easily  soluble  in  excess  of  KI.  or  iu  great 
excess  of  mercuric  salt.  (7)  Stannous  chlorid,  in  small  quantity: 
white  ppt.;  in  larger  quantity:  gray  ppt,;  and  when  boiled:  deposit  of 
ghibnles  of  Hg. 

Action  on  the  Economy, — Mercury,  in  the  metallic  form,  is  with- 
out action  upon  the  animal  economy  so  long  as  it  remains  such.  On 
t*otit}ict,  however,  with  alkaline  chlorids  it  is  converted  into  a  soluble 
di>uble  chlorid,  and  this  the  more  readily  the  gi^ater  the  degree  of 
subdivision  of  the  metal.  The  mercurials  insoluble  in  dilute  HCl  are 
also  inert  until  they  are  converted  into  soluble  compounds. 

Mercuric  chlorid,  a  substance  into  which  many  other  compounds 
of  Ug  are  converted  when  taken  into  the  stomach  or  applied  to  the 
skio»  not  only  has  a  distinctly  corrosive  action,  by  virtue  of  its  ten- 


4 


MERCURY  261 

dency  to  unite  with  protein  bodies,  but,  when  absorbed,  it  produces 
well-marked  poisonous  eilects,  somewhat  similar  to  those  of  arsenical 
I>oi80Ding.  Indeed,  owing  to  its  corrosive  action,  and  to  its  greater 
solubility  and  more  rapid  absorption,  it  is  a  more  dangerous  poison 
than  AS2O3.  In  poisoning  by  HgCk,  the  symptoms  begin  sooner 
after  the  ingestion  of  the  poison  than  in  arsenical  poisoning,  and 
those  phenomena  referable  to  the  local  action  of  the  toxic  are  more 
intense.  But  the  entire  duration  of  the  poisoning  is  greater,  In  fatal 
cases,  death  usually  occurs  in  5  to  12  days. 

The  treatment  should  consist  in  the  administration  of  white  of 
egg,  not  in  too  great  quantity,  and  the  removal  of  the  compound 
formed,  by  emesis,  before  it  has  had  time  to  redissolve  in  the  alkaline 
chlerids  contained  in  the  stomach. 

Absorbed  Hg  tends  to  remain  in  the  system  in  combination  with 
protein  bodies,  from  which  it  may  be  set  free,  or,  more  properly, 
brought  into  soluble  combination,  at  a  period  quite  removed  from  the 
date  of  last  administration,  by  the  exhibition  of  alkaline  iodids. 

Mercury  is  eliminated  principally  by  the  saliva  and  urine,  in  which 
it  may  be  readily  detected.     The  fluid  is  faintly  acidulated  with  HCl, 
uid  in  it  is  immersed  a  short  bar  of  Zu,  around  which  a  spiral  of 
dentist's  gold  foil  is  wound  in  such  a  way  as  to  expose  alternate  sur- 
faces of  Zn  and  An.     After  24  hours,  if  the  saliva  or  urine  contain 
Hg,  the  An  will  be  whitened  by  amalgamation;  and,  if  dried  and 
Wted  in  the  closed  end  of  a  small  glass  tube,  will  give  off  Hg,  which 
condenses  in  globules,  visible  with  the  aid  of  a  magnifier,  in  the  cold 
Partot  the  tube. 


262 


MANUAL    OP    CHEMISTRY 


ORGANIC    CHEMISTRY. 
COMPOUNDS  OF  CARBON. 


In  the  beginning  of  the  nineteenth  century  chemistry  was  dividi*<1 
into  the  two  sections  of  inorganic  and  organic.  The  former  ti'^^ated.^ 
of  the  prodnctsof  the  mineral  woHd,  the  hitter  of  substances  proih)oe<l 
In  organizfd  bodies,  vegetable  or  animal.  This  subdivision,  originally 
made  upon  the  supposition  that  organic  substances  eonid  only  be  pro- 
duced by  'Hital  processes/'  is  retained  only  for  convenience  and  be- 
cause of  the  great  number  of  the  carbon  compounds. 

When  it  was  found  that  organic  substances  were  made  up  of  a 
very  few  elements ,  and  that  they  all  contained  carbon,  Gmelin  pro- 
posed to  consider  as  organic  substances  all  such  as  contained  more 
than  one  atom  of  0;  bis  object  in  thus  limiting  the  mioimum  number 
of  C  atoms  being  that  substances  containing  one  atom  of  C,  such  as 
carbon  dioxid  and  marsh  gas,  are  formed  in  the  mineral  kingdom, 
and  consequently,  according  to  then  existing  views,  could  not  be  con- 
sidered as  orgame.  Such  a  distinction,  still  adhered  to  in  text*books 
of  very  recent  date,  of  neeesstty  leads  to  most  incongruous  results. 
Under  it  the  first  terms  of  the  homologous  series  (see  p.  264)  of  satu- 
rated hydrocarbons,  CH^,  alcohols,  CH|0,  acids,  CHsO^t  and  all  their 
derivatives  are  classed  among  tniiieral  substances,  while  all  the  higher 
terms  of  the  same  series  are  organic.  Under  it  iirea»  CON2H4,  the 
chief  product  of  excrctiou  of  the  animal  body,  is  a  mineral  substance, 
but  ethene,  C2H4,  obtaiued  from  the  distillation  of  coal,  is  organic. 

The  idea  of  organic  chemistry  conveyed  by  the  definition:  "that 
branch  of  the  science  of  chemistry  which  treats  of  the  carbon  com- 
pounds containing  hydrogen,"  is  still  more  fantasttc.  Under  it  hy- 
drocyanic acid,  CNH,  is  *■  organic,^'  but  the  cyan  ids,  CNK,  are 
** mineral."  Oxalic  acid,  C2O4H2,  is  ^* organic,"  and  potassium  hy- 
droxid,  KHO,  uuquestiouablj^  ^^mineraL"  If  these  two  act  upon 
each  other  in  the  proportion  of  90  parts  of  the  former  to  ^^  of  the 
latter,  the  ''organic"  raonopotassie  oxalate,  C2O4HK,  is  formed,  bnt 
if  the  proportion  of  KHO  be  doubled,  other  conditions  remaining  the 
same,  the  'hnineral"  dipotassic  oxalate,  €204X2,  is  produced.  Simi- 
larly one  of  the  sodium  carbonates,  NaaCOa,  is  " mineral  j"  the  other^ 
NaHCOs,  is  ** organic." 

The  notion  that  organic  substances  could  only  be  formed  by  some 
mysterious  agency,  manifested  only  in  organized  beings,  was  finally 
exploded  by  the  labors  of  Wohler  and  Kolbe.  The  former  obtained 
urea  from  ammonium  cyauate  {1828};  while  the  latter,  at  a  subse- 


COMPOUNDS    OP    CARBON  263 

qaent  period,  formed  acetic  acid,  using  in  its  preparation  only  such 
unmistakably  mineral  substances  as  coal,  sulfur,  aqua  regia,  and 
water.  Since  Wohler's  first  synthesis,  chemists  have  succeeded  not 
only  in  making  from  mineral  materials  many  of  the  substances  pre- 
viously only  formed  in  the  laboratory  of  nature,  but  have  also  pro- 
duced a  vast  number  of  carbon  compounds  which  were  previously 
unknown,  and  which,  so  far  as  we  know,  have  no  existence  in 
nature. 

At  the  present  time,  therefore,  we  must  consider  as  an  organic 
substance  any  compound  containing  carbon,  whatever  may  be  its  origin 
and  whatever  its  properties. 

Organic  chemistry  is,  therefore,  simply  the  chemistry  of  the  car- 
bon compounds.  In  the  study  of  the  compounds  of  the  other  ele- 
ments, we  have  to  deal  witU  a  small  number  of  substances,  relatively 
speaking,  formed  by  the  union  with  each  other  of  a  large  number  of 
elements.  With  the  organic  substances  the  reverse  is  the  case. 
Although  compounds  have  been  formed  which  contain  C  along  with 
«aeh  of  the  other  elements,  the  great  majority  of  the  organic  sub- 
stances are  made  up  of  C,  combined  with  a  very  few  other  elements; 
H,  O,  and  N  occurring  in  them  most  frequently. 

It  is  chiefly  in  the  study  of  the  carbon  compounds  that  we  have  to 
deal  with  radicals  (see  p.  84).  Among  mineral  substances  there 
are  many  whose  molecules  consist  simply  of  a  combination  of  two 
atoms.  Among  organic  substances  there  is  none  which  does  not 
contain  a  radical:  indeed,  organic  chemistr>'  has  been  defined  as  ^*the 
chemistry  of  compound  radicals.'' 

The  atoms  of  carbon  possess  in  a  higher  degree  than  those  of  any 
other  element  the  power  of  uniting  with  each  other,  and  in  so  doing 
of  interchanging  valences.  Were  it  not  for  this  property  of  the  C 
atoms,  we  could  have  but  one  saturated  compound  of  carbon  and 
hydrogen,  CH4,  or  expressed  graphically: 

H 

I 
H— C— H 

I 
H 

There  exist,  however,  a  great  number  of  such  compounds,  which 
differ  from  each  other  by  one  atom  of  C  and  two  atoms  of  H.  In 
these  snbstances  the  atoms  of  C  may  be  considered  as  linked  together 
in  a  continuous  chain,  their  free  valences  being  satisfied  by  H  atoms, 
thns: 

H  H   H  H   H   H    H 

I  II  III' 

H-C— H  H-C— C— H  H— C-C-C-C-H 

I  II  I      I      I      I 

H  H  H  H   H   H   H 


264 


MANUAL    OF    CHEMISTRY 


Homologous  Series. — It  will  be  obsei-ved  that  these  formulie' 
differ  from  each  other  by  CH2,  or  some  iiiultiple  of  CH2,  more  or  less. 
In  exaiiiitiiug  numbers  of  organic  substances  which  are  closely  related 
to  each  other  in  their  properties,  we  find  that  we  (ran  arran^je  the 
great  majority  of  them  in  series,  each  terra  of  which  d Lifers  from  the 
one  below  it  by  C'llg;  such  a  series  is  called  an  homologous  scries^ 
It  will  be  readily  understood  that  such  an  arrangement  in  series  vastl>' 
facilitates  the  remembering  of  the  composition  of  organic  bodies.  1 11 
the  following  table,  for  example,  arc  given  the  saturated  hydrocar- 
bons, and  their  more  immediate  derivatives.  At  the  head  of  eaeb 
vertical  column  is  an  algebraic  formula,  which  is  the  general  formula 
of  the  entire  series  below  it;  n  being  eqtial  to  the  numerical  position 
in  the  series.  j 

HOMOLOGons  sehIes. 


AleohoU, 

AldehyduB 

And>, 

Ketones, 

OnHM.-h.O 

CnH.iO 

ChH^O. 

OnHa^O           J 

CH, 

CH4O 

CHaO 

CO2H2 

- 

C,He 

CjHoO 

C3H1O 

C.O,H, 

■    .    i 

CiHa 

CiH,0 

CsH^O 

C.OjHe 

CjH^O 

C^H.a 

C4Hi„0 

CiH^O 

C^OjHb 

C^HgO 

CfiHis 

C5H,,0 

CsHioO 

CfiOifHio 

CsHioO 

CttHi* 

C.HuO 

CoH,,0 

C,0:H,2 

.... 

C:Hi, 

e-H,«o 

V^UuO 

CtOoHh 

CsHiB 

C«Hi.O 

CaHiaO 

C^O^Hio 

...» 

C»Hffo 

C»H',i,0 

.   •    I   . 

CgOiHii 

*              *             •               *u 

C|»H23 

C10H22O 

.... 

Cit^OaHio 

*     *     *     » 

C,,Ha4 

.... 

.    .    •    . 

.    •    .    * 

CuHid 

.    .   .    . 

.    ■   •   * 

CiaO^Ha, 

•    »    •    - 

C,jH,e 

.    «    .   « 

<■    .   »   • 

.  .  .  , 

CnHao 

.    .   .    - 

.... 

CuOoH.a 

*   ,   .   . 

But  the  arrangement  in  homologous  series  does  more  for  us  than 
this.     Tlie  properties  of  substances  in  the  same  series  are  similar,  or^S 
vary  in  regular  gradation  according  to  their  position  in  the  series.^" 
Thus,  in  the  series  of  monoatomie  alcohols  {see  al>ove)  each  member 
yields  on  oxidation,  first  an  aldehyde,  then  an  acid.     Each  yields  tt 
series  of  compound  ethei's  by  the  action  of  acids  upon  it.     The  boil- 
ing-points of  ethylic  alcohol  and  its  seven  superior  homologues  aiHi^idf 
78,3'',  97.4^  116,8°    137^  157^  176"*,  195°,  from  which  it  will  he^ 
seen  that  the  boiling -point  of  any  one  of  them  can  be  determined,, 
with  a  maximum  error  of  less  than  1°,  by  taking  the  mean  of  those 
of  its  neighbors  above  and  below.     In  this  w^ay  we  may  predict,  to 
some  extent,  the  properties  of  a  wanting  member  in  a  series  before  its 
discovery,  ^M 

The  terms  of  any  homologous  series  must  all  have  the  same  con-™ 


COMPOUNDS    OF    CAEBON 


265 


stitutlont  i*  e.»  their  constltueut  atoms  must  bti  similarly  arranged 
within  the  molecule,    (Seep.  84 J 

Isomerism — Metamerism — Polymerism, —  Two  suhsiances  are 
said  to  he  i^omeri(\  or  to  he  homerts  of  mrh  othei\  when  they  have 
the  same  perceniuge  composition.  It,  for  iustauct%  we  analyze  acetic 
acid,  formic  aldehyde  and  methyl  formate,  we  find  that  eaeh  body 
consists  of  C,  O  aud  H,  in  tlie  foUowiug  proportions: 

Carbon 40  =12 

Oxygen 53.3E    —     16 

Hydrogen 6.67    —      2 

laO.OQ  30 

This  identity  of  percentage  composition  may  occur  in  two  ways. 
The  three  substances  may  each  contain  tiie  same  number  of  each  kind 
of  atom  in  a  molecnie;  or  they  may  contain  in  their  several  molecules 
the  same  kinds  of  atoms  in  multiple  proportions.  In  the  above  ex- 
ample each  substance  may  have  the  forjnnla,  CH2O;  or  one  may  have 
that  formula  and  the  others,  CoH^Oj,  CsHbOs,  C4Hg04,  C5H10O5,  etc. 

When  two  or  more  std^stanccs  hare  the  same  percentage  com- 
pagilioH  and  the  same  fuotecidar  weight  they  are  said  to  be  meta- 
meric^  When  they  have  the  same  percentage  eomposifion  and  their 
fmolecular  weights  are  simple  multiples  of  (he  loicesf  molecular 
weight  represented  hg  that  percentage  composition  ^  theij  are  said  to 
be  polymeric. 

Other  conditions  of  isomerism  will  be  considered  later  (see  space 
isamerism^  p.  311,  and  place  isomerism,  pp.  339,  436). 

In  order  to  determine  the  composition  (the  empirical  formula)  of 
an  organie  substance^  two  factors  are  tlierefore  necessary  :  the  per- 
centage composition  and  the  njolecuhir  weight. 

Elementary  Organic  Analysis. — The  first  step  iu  an  analysis  to 
determine  the  composition  of  an  organic  substa«nce  is  a  qualitative 
analysis  to  identify  the  elements  existing  in  the  molecule.  This 
Laving  been  done,  the  quantitative  analysis  is  next  in  order* 

The  simplest  case  is  where  the  substance  is  a  hydroearbon,  i.  e., 

a  compound  of  carbon  and   hydrogen  only.     The  determination   of 

both  elements  is  made  in  one  ofveration,  by  taking  advantage  of  the 

fart  that  when  a  compound  containing  carbon  and  hydrogen  is  heated 

^itlv  cuprie  oxid  all  the  carbon  is  converted  into  CO2,  and  all  the 

Mrogen  into  H2O.     Thus,  if  C2H60+6CuO=2C02+3H20+6Cn,  46 

parts  of  alcohol  will  produce  88  pts.  of  carbon  dioxid  and  54  pts.  of 

^ater.    The  apparatus  required  eonsists  of  a  tube  of  difflcnltly  fusible 

Klaas,  called  a  combustion  tube,  about  60  cent,  long,  drawn  out  to  a 

I'^iiit  and  closed  at  one  end,  a  "combustion  furnace,"  iu  which  this 

wbe  may  be  heated,  aud  the  absorbing  apparatus  referred  to  below. 


266 


MANUAL    OF    CHEMISTRY 


A  weighed  quantity  of  the  substance  of  which  a  "combustion  "  is  to  be 
made  (sealed  in  a  small  glass  bulb  if  liquid)  is  placed  in  the  closed 
end  of  the  combustion  tube,  a  Fig.  39,  along  with  the  requisite  quan- 
tity of  recently  ignited  cupric  oxid,  leaving  space  for  the  passage  of 
the  gases  produced.  The  tube  is  then  placed  in  the  furnace  and  its 
open  end  connected  with  a  U  tube,  6,  filled  with  fused  CaCU,  or  with 
fragments  of  pumice  moistened  with  concentrated  H2SO4,  whose 
weight  has  been  determined,  and  whose  purpose  it  is  to  absorb  the 
H2O  produced.  This  fii'st  U  tube  is  connected  with  a  "Liebig's  bulb" 
containing  a  strong  solution  of  KIIO,  c,  and  this  in  turn  with  another 
U  ttibe  in  all  respects  similar  to  the  first,  d,  both  c  and  d  having  been 
previously  weighed.  The  purpose  of  c  is  to  absorb  the  CO2  produced, 
that  of  d  to  retain  water  carried  over  from  c  by  the  current  of  gas. 
The  combustion  tube  is  then  carefully  heated  until  the  evolution  of 
gases  ceases,  when  the  closed,  drawn-out  end  of  the  tube  is  broken 
and  connected  with  a  gasometer  containing  pure,  dry  oxygen,  a  cur- 


\ 


FlO.  39. 

rent  of  which  is  passed  slowly  through  the  apparatus  to  bring  the  last 
portions  of  the  products  of  combustion  into  the  absorbing  apparatus. 
Finally  the  U  tubes  and  the  KHO  bulb  are  again  weighed.  The 
increase  in  weight  of  h  is  the  weight  of  H2O  produced,  every  9  parts 
of  which  represent  1  part  of  H.  The  increase  in  weight  of  c  and  d 
is  the  weight  of  CO2  produced,  every  44  parts  of  which  represent  12 
parts  of  C.  If  the  substance  analyzed  contain  N,  CI,  Br  or  I,  a  heated 
•column  of  pure  metallic  Cu  is  interposed  toward  the  open  end  of  the 
combustion  tube,  to  reduce  any  oxids  of  N  produced  to  N,  and  to 
retain  the  CI,  Br  or  I.  If  the  substance  contain  S,  a  layer  of  lead 
peroxid  is  similarly  placed  to  retain  the  S  as  PbS04. 

If  the  substance  consist  of  C,  H  and  O,  the  C  and  H  are  deter- 
mined in  the  manner  above  described,  and  the  difference  between  the 
sum  of  their  weights  and  that  of  the  substance  burnt  is  the  amount 
of  O. 

Nitrogen  is  most  readily  determined  by  the  method  of  Ejeldahl. 
A  known  w^eight  of  the  substance  is  dissolved  by  heating  it  in  concen- 
trated H2SO4.     Potassium  permanganate  is  then  added  until  the  mix- 


COMPOUNDS    OF   CAEBON 


267 


tnre  is  green.  The  N  contained  in  the  substance  is  thus  converted 
into  ammonia.  The  strongly  acid  liquid  is  diluted,  rendered  alkaline 
by  addition  of  NaHO,  and  the  NH3  is  distilled  over  into  a  ri-ceiver 
containing  a  known  quantity  of  acid.  The  amount  of  NH3  produced 
is  caleulat>ed  from  the  amount  of  acid  neutralized,  and  every  17  parts 
of  NH3  represent  14  parts  of  N.  In  the  analysis  of  nitro-  and  cyano- 
gen compounds  sugar  is  added,  and  in  that  of  nitrates,  benzoic  acid. 

Two  other  methods  of  determining  N  are  in  general  user  That  of 
Dumas,  in  which  the  substance  is  burnt  in  a  manner  very  similar  to 
that  above  described,  and  the  N  produced  is  collected  and  measured. 
The  weight  of  N  is  then  calculated  from  the  volume,  with  the  neces- 
sary corrections  for  variations  of  temperature  and  i>ressure.  In  the 
method  of  Will  and  Varrentrap  the  N  of  the  compound  is  converted 
into  NH3  by  heatiug  with  a  caustic  alkali,  and  the  aujount  of  Nlly  is 
determined  as  in  Kjeldahrs  method*  For  the  details  of  these  pro- 
and  for  methods  of  determination  of  other  elements  in  organic 
^eompotinds  the  student  is  referred  to  works  on  quantitative  analysis, 
8ach  as  that  of  Fresenius.  The  details  of  the  directions  must  be 
rigidly  nb served  to  avoid  error. 

Determination  of  Molecular  Weights, — ^The  percentage  compo- 
sition having  been  determined » the  simplest  corresponding  ratio  of  the 
atoms  in  the  molecule  is  obtained  by  dividing  the  jiercentage  of  each 
element  by  its  atomic  weight.  Thus  if  analyses  be  made  of  formic 
aldehyde^  acetic  acid,  methyl  formate,  lactic  acid  nnd  ^hiccse,  the 
results  in  each  case  will  be : 


Carbon  .... 
Oxygen.  .    .   . 


40.00  per  cent. -t- 12  =  3-33=1 
6.67     '*      *'     ■+■    l  =  a,07^2 

rKi.:j3    **     '*   -i_!6  =  a.33=i 


und  the  simplest  empirical  formula  of  all  of  the  substanees  mentioned 
is  therefore  CH^O,  The  molecular  weight  of  formic  aldehyde  is  30; 
its  fttrniula  ia  therefore  CFI^O  (12+2+16).  The  molecular  weights 
of  acetic  acid  and  of  methyl  formate  are  60:  they,  therefore,  each 
bave  the  formula  C2H4O2.  The  molecidar  weight  of  lactic  acid  is  90 
and  that  of  glucose  180:  the  formula  of  the  former  is,  therefore, 
C8H«03,  and  that  of  the  latter  CJirjOe, 

If  the  substance  be  one  which  can  be  vaporized  without  decompo- 
fiition,  its  molecular  weight  ia  derived  from  its  specific  gravity  as 
referred  to  hydrogen  in  the  manner  already  described  {p.  56 )\  The 
process  for  determining  the  specific  gravity  now  generally  adopted  is 
that  of  Victor  Meyer.  (See  Ganot's  Physics,  15th  Am.  Eld.,  p.  381, 
or  other  works  upon  that  subject.)  If  the  substance  be  one  which 
cannot  be  vaporized  without  ileeoniposition,  its  molecular  weight  mny 
naaally  be   determined   by  the    treezing  or   boiling   point   methods 


268 


MANUAL     OF    CHEMISTRY 


referred  to  on  pp.  G8,  69.  In  some  cases  ueitber  of  these  phj^sical 
methods  are  applicable.  Then  cht/siiical  methods  must  be  resorted  to. 
These  consist  in  produeins  derivatives,  which  are  then  analyzed  and 
the  results  thns  obtained  compared  with  the  formula  deducible  from 
the  analysis  of  tlie  original  eomponnd.  These  methods  are  sometimes 
exeeediiigly  complicated,  in  other  cases  very  simple.  When  the  sub- 
stance is  a  base  or  an  acid  it  is  converted  into  a  mineral  ester  or  into 
a  salt,  and  the  combined  mineral  acid  or  metal  is  determined.  For 
example:  Acetic  acid  and  lactic  acid  both  have  the  percentage  com- 
position C=40-00  per  cent,  H^6.67  per  cent,  0=53,33  per  cent, 
corresponding  to  the  formula  CH-jO,  or  some  multiple  thereof.  The 
atomic  weight  of  silver  is  107.7*  If  the  two  acids  are  converted  into 
their  silver  salts,  and  the  amount  of  silver  in  each  determined,  the 
acetate  will  be  found  to  contain  64.6  per  cent  of  silver,  and  the 
lactate  54.8  per  cent.  If  both  acids  are  monobasic  the  former  per- 
centage of  silver  corresponds  to  the  for  nulla  C2H302Ag,  and  the  latter 
to  the  formula  CaHsOaAg.  The  basicity  of  the  acid  is  determined 
from  the  increase  of  molecular  conductivity  of  solutions  of  its  sodium 
salt  on  dilution,  by  the  method  referred  to  ou  p.  75. 

Determination  of  Constitution* — The  identity  and  pmperties  of 
organic  compounds  depend  not  only  upon  their  composition^  L  e.»  the 
number  and  kind  of  atoms  composing  the  molecule,  but  also  upon 
their  constittdion,  i*  e.,  the  arrangement  of  the  atoms  in  the  molecule 
{see  p.  84).  The  constitution  of  a  substance  is  determined  by  a 
study  of  the  methods  of  its  formation,  of  the  products  of  its  decom- 
position, and  of  the  substances  produced  by  the  introduction  of  other 
elements  or  groups  into  its  molecule.  A  statement  of  the  more 
important  principles,  and  one  or  two  exam  pies ,  must  suffice  here,  the 
subject  being  further  developed  in  the  sequel. 

The  carbon  atom  is  quadrivalent  in  almost  all,  if  not  in  all  organic 
compounds.  In  the  few  in  which  it  is  considered  as  bivalent,  as  iu 
carbon  monoxid,  CO,  and  the  isonitrils,  (C2H5) — N  — C,  the  oxygen 
may  be  considered  to  be  quadrivalent,  and  the  nitrogen  quinquiva* 
lent,  in  which  case  the  carbon  would  be  quadrivalent. 

The  carbon  atoms  may  unite  with  each  other  in  three  ways: 
(1)  Two  carbon  atoms  raaj^  exchange  a  single  valence  in  their  union « 
forming  a  hexavaleut  group, =  C — C=;  (2)  they  may  unit  with  ex- 
change of  two  valences,  forming  a  quadrivalent  group,  ^C^C=; 
or,  (3)  they  may  unite  with  exchange  of  three  valences,  forming  a 
bivalent  group,  — C^C — .  These  are  referred  to  as  single,  double 
and  treble  linkages,  respectively. 

Those  compounds  in  which  all  of  the  linkages  are  single,  and  in 
which  all  of  the  possible  valences  of  the  constituent  atoms  are  satisfied 
are  saturated  compounds.    No  other  atom  or  radical  can  be  intro- 


COMPOUNDS    OF    CABBON 


269 


'dueed  into  a  saturated  Miolecule  except  by  substitution,  i,  e.,  by 
cflusiDg  the  iotroduced  atom  or  radical  to  take  tlie  place  of  some 
cither,  or  others,  of  equivalent  valence,  siinultaueousiy  removed.  Thus, 
when  chloroform  (itself  a  sobgtitiited  derivative  of  marsh  gas,  CH4) 
is  converted  into  carbon  tetrachloride  (be  remaining  hydrogen  is 
removed  as  hydrochloric  acid:   CHChi  +  Cl2^CCl4  + HCl. 

Only  snch  substances  as  contain  two  carbon  atoms  donbly  or 
trebly  linked,  =C^C=  or  — C^C — ,  are  usually  considered  as 
unsaturated  compounds,  Sucb  compounds  may  be  mc»dified  both  by 
substitution  and  by  addition,  i.  t\,  by  breaking  out  the  double  or 
treble  linkages  and  the  introduction  of  two  new  univalents,  or  one 
bivalent,  for  each  linkage  so  liberated.  Thus,  ethylene  yields  ethylene 
chlorid  by  addition:  HiCiCH.  +  Cl.^ClH.C.CHiCl;  or,  by  substitu- 
tion and  addition,  carbon  hexachlorid:  H2C:CH2+5Cl2=Cl3C.CCl3+ 
4HCL  (See  also  pp.  273,  284,)  But  compounds  in  which  all  of  the 
carbon  atoms  are  singly  interlinked  may  also  form  products  of  addi- 
tion, and  in  this  sense  are  unsaturated,  if  they  contain  a  double 
linkage  between  a  carbon  atom  and  a  bivalent.  Thus,  the  aldehydes 
and  ketones  form  alcohols  as  addition  products  with  hydrogen: 


^O  >0H 


and 


0:CC  tH2=^        >CC 


In  the  reactions  referred  to  above  in  which  chlorin  is  substituted 
for  hydrogen,  it  is  not  only  added  to  the  molecule  operated  upon,  but 
also  removes  hydrogen  by  combining  w^ith  it,  and  bence  two  atoms  of 
chlorin  are  required  for  each  atom  of  hydrogen  removed.  Similarly, 
when  O  removes  H-i,  in  oxidations,  two  atoms  of  oxygen  are  required 
for  each  two  atoms  of  hydrogen  removed,  as  when  alcohol  is  oxidized 
to  acetic  acid:  C2HflO+02=C2H^02+H20.  Consequently  in  oxidations 
an  even  number  of  hydrogen  atoms  is  always  removed.  The  tendency 
to  the  formation  of  water  is  so  strong  that  in  reactions  in  which  two 
or  more  hydroxyl  groups  should  unite  with  the  same  carbon  atom, 
water  almost  invariably  splits  off  and  oxygen  unites  doubly  with  the 
r»irhoo*  Thus  caustic  potash  does  not  act  upon  ethidene  chlorid  to 
pt^mluce  a  glycol  according  to  the  equation  CH3.CHCl2  +  2KHO  = 
VHi  rH(0H):;+2KCI,  but  to  produce  an  aldehyde  according  to  the 
eM"Htion,  CH3.CHCl2+2KHO=CH3.CHO+Il20+2KCL 

Exceptions  to  this  rule  occur  when  the  carbon  atom  is  linked  to 
n  nor  her  carbon  atom  contained  in  a  highly  oxidized  or  halid  group, 
ft  14  111  the  compounds: 

COOH  CCla  COOH 


'/OH 
"*"\0H 


Oljroxallje  u'id« 


T,L/OH 


CblorjiJ  hydnit«. 


l/OH 

r\oH 

COOH 

MhoahIk-  acid. 


270 


MANUAL    OP    CHEMISTRY 


Usually  when  an  atom  or  group  replaces  another  in  a  compound 
it  occupies  the  position  vacated  by  that  which  is  removed,  as  when 
alcohol  is  formed  by  the  action  of  caustic  potash  upon  ethyl  iodid: 
CH3.CH2l  +  KHO=CH3.CH20H  +  KI.  There  is  an  exception  to 
this  rule  when  an  unsaturated  compound  may  yield  either  another 
unsaturated  compound  in  obedience  to  the  rule  or  an  isomeric  satu- 
rated compound  in  violation  to  it,  the  more  stable  saturated  com- 
pound is  formed.  Thus  the  hydration  of  vinyl  bromid,  CH2:CHBr, 
does  not  produce  vinyl  alcohol,  CH2 :  CHOH,  but  its  isomere :  aldehyde, 
CH3.CHO.  Indeed,  unsaturated  compounds  are  frequently  converted 
into  saturated  isomeres  by  intramolecular  transposition  of  atoms  by 
mere  application  of  heat. 

The  genesis  of  ethylic  alcohol  from  the  action  of  caustic  potash 
upon  ethyl  iodid:  CH3.CH2l  +  KHO=CH3.CH20H  +  KI,  shows  that 
the  alcohol  contains  the  univalent  group  CH2OH,  which,  on  oxida- 
tion, may  lose  two  atoms  of  hydrogen  with  formation  of  either  one 
of  the  two  univalent  groups  CHO,  or  COOH;  which  occur  in  the 
products  of  oxidation  of  ethylic  alcohol:   aldehyde  and  acetic  acid. 

The  groups  CH2OH,  CHO  and  COOH,  referred  to  above,  are 
examples  of  the  so-called  characterizing  groups  which  exist  in  the 
molecules  of  different  classes  of  substances.  The  following  are  the 
more  commonly  recurring  characterizing  groups,  and  the  classes  of 
substances  in  which  they  occur: 


(CHjOH)' 

_     H\c/H 

in  primary  alcohols,  called  meihaxylf 

(CHOH)" 

-  HO/^- 

' '  secondary  alcohols, 

(COH)'" 

=    iC.OH 

**  tertiary  alcohols, 

(CHO)' 

=  o=c<H 

**  aldehydes, 

(CO)" 

=  0:C: 

**  ketones,  called  carbonyl,* 

(COOH)' 

=  0=C<OH 

**  acids,  csAled  carboxyl, 

(SOjOH)' 

=  0)8<0H 

**  sulfonic  acids, 

(80,)" 

=  »«= 

**  sulfones. 

(NH,)' 

=  H2:N. 

"  amido  compounds, 

(NH)" 

=  H.N: 

'*  imido  compounds, 

(NO,)' 

-8>- 

**  nitro  compounds, 

(NO)' 

=  0:N. 

**  nitroso  compoundB. 

*Thii  sronp  also  exiiti  in  other  compounds,  as  in  the  aldehydes  and  aeldi  in  the  manner  indf* 
eated  in  the  text,  and  in  compounds,  such  as  carbonyl  chlorid,  COCls,  urea.  NHs.CO.NHa,  etc. 


COJIPOUNDS    OF    CAKBON 


271 


Nomenclature  of  Organic  Compounds. — Tlie  vast  nnmli^^r  ntid 
Vpreat  variety  of  structure  of  organic  compounds  make  it  difficult  to 
devise  a  system  of  nomenclature  which  will  apply  to  the  more  com- 
plex derivatives  without  producing  names  which  are  most  complicated 
and  difficult  of  pronunciation.  Indeed,  in  view  of  the  constantly 
increasing  number  of  cai'bon  compounds,  no  complete  system  of  no- 
tnenelature  is  as  yet  possible.  The  most  recent  attempt  to  formulate 
one  is  that  of  the  Geneva  Commission  of  1892.  In  this  system  the 
names  of  the  hydrocarbons  serve  as  the  roots  from  wliieh  the  names 
of  their  derivatives  are  constructed  by  the  addition  of  syllables  indi- 
cating the  function  (see  p.  63)  of  the  substance.  Thus  the  alcohols 
ir«  indicated  by  the  syllable  ol,  the  aldehydes  by  at,  the  ketones  by  on, 
Taiid  the  acids  by  the  word  acid.  The  •*  Geneva"  name  of  ethylic  alco- 
hol would  be  ethanot,  that  of  acetic  aldehyde  ethanal  and  that  of 
etic  acid  ethan-arid.  These  names  have  not  come  into  general  use. 
In  the  nomenclature  generally  followed  the  name  of  a  substance 
is  made  up  of  the  name  of  that  of  the  class,  or  "function,"  to  which 
the  substance  belongs,  as  acid,  {ilcohol,  hfone,  fster,  etc.,  to  which 
are  added  a  qualifying  word  derived  from  the  origin  of  the  body,  as 
lartic  acid,  acetic  acid,  etc.,  or  from  its  composition,  as  mefhylk  aleo- 
Fhol,  fihylic  ether,  etc.,  and  the  names  of  any  radicals  which  ha%'e  been 
fintroduced  into  the  molecule  of  the  parent  compound.  Thus  the 
name  of  the  substance  COOH.CII2  (NH.CHjj)  is  mefhyl-amido'acetic 
acid,  in  which  '^acetic  acid'^  indicates  that  it  is  derived  from  acetic 
acid,  COOH.CH3,  the  syllable  amido  that  NH2  has  been  substituted 
for  H  in  the  CH3  of  the  acid,  and  methyl  that  CH3  has  been  substi- 
tuted for  H  in  NHj. 

The  names  of  the  uuivalent  radicals  terminate  in  yl,  as  methyl 
(CHa)',  *thyl  (C^Hr,)',  acHyi  (C2H:jO)',  etc.  Those  of  bivalent  radi- 
cals termiuate  in  em,  as  methylene,  (CH2)",  ethidene  (C-^Ht)'',  etc, 
and  those  of  the  trivalent  radicals  in  enyl  or  in  ine,  as  meihenyl  or 
methine  (CH)"',  rthenyl  or  rthine  (CoHj)"',  etc. 

Classification  of  the  Carbon  Compounds.  —  The  hydrocarbons, 
consisting  of  carbon  and  liydrogen  only,  constitute  the  framework  of 
the  classification  adopted,  all  other  ciirbon  comptmnds  being  consid- 
ered as  derivable  from  the  hydrocarbons  by  substitution  nr  by 
addition. 

Carbon  compounds  are  divided  into  two  great  c lasses,  differenti- 
ated by  the  mangier  iu  which  the  carbon  atoms  are  linked  together: 

A,  Open  Chain  Compounds,  also  called  avyelir^fafifj,  or  aliphatic 
(aX<i^^^fat)  compounds.  In  these  coniponnds  tb^  t-arbon  atoms 
are  attached  to  each  other  in  an  open  or  arborescent  chain,  in  which 
two  or  more  carbon  atoms  are  linked  to  but  one  other  carbon  atom, 
as  in  the  com  pounds: 


272  MANUAL    OP    CHEMISTRY 

H   H   H   H   H   H 
^       I      I      I      I      i      I  /CHt.CHa 

H— C— C— C—C— C— C— H  CHa.CHi.CH 

I      I      I      I      I      I  \CH3 

H   H   H   H   H   H 

In  the  hydrocarbons  of  this  class  the  number  of  hj'drogen  atoms, 
or  this  number,  plus  the  number  of  univalent  atoms  that  can  be  in- 
troduced into  the  molecule  by  addition,  is  equal  to  twice  the  number 
of  carbon  atoms  plus  two. 

B.  Closed  Chain  Compounds,  also  called  cyclic  or  aromatic  com- 
pounds. These  compounds  contain  one  or  more  closed  chains^  rings, 
or  nuclei  in  which  each  carbon  atom  is  linked  to  at  least  two  other 
carbon  atoms,  or  their  equivalent,  as  in  the  compounds: 

H  Ha  H       H 

I  II  I 

C  0  H    H    H    H  C 

^\  /Mill  /%   .      , 

H— C        0— H        H2=C        C— C— C— C— H       H— C        C        C— H 

I         II  I         I     I      I      >  >l  I         I 

I         II  I         I     H  H    H  II  I         I 

H-C        0— H  H2=C       C=H2  H— C        C        C— H 

\/  \/  \^  \^ 

C  N  CO 

I  I  II 

H  H  H       H 

Benzene.  Coniin.  Naphthalene 

The  closed  chain  compounds  are  subdivided  into  two  classes: 

I.  Carhocyclic  compounds,  in  which  the  ring  or  rings  consist  of 
carbon  atoms  exclusively,  as  in  benzene  and  naphthalene,  and 

II.  Heterocyclic  compounds,  in  which  atoms  of  elements  other  than 
carbon  enter  into  the  composition  of  the  ring,  as  in  coniin. 


i 


CUMPOCTNDS 


273 


OPEN  CHAIN,  ALIPHATIC,  ACYCLIC  OR  FATTY 
COMPOUNDS. 


HYDROCARBONS. 

Six  series  are  knowti : 

A,  Methane,  or  Paraffin  Series,  These  are  saturated  com- 
pounds and  have  the  algebraic  foriuula,  CnHon^s.  Their  names  ter- 
minate ia  "ane.**  e.  g..  Butane,  CIIa.CHo.CHa.CHa. 

Bt  Olefin  Series^  containing  two  doubly -linked  carbon  atoms. 
<jeneral  formula  Cnll-M.  Their  names  terminate  in  "ene,"  e.  g., 
Batene,  CHirCH.CH2.CHa. 

C»  Acetylene  Series,  containing  two  trebly* linked  carbon  atoms. 
Algebraic  formula,  C»H2ii-2.  Their  names  terminate  in  '4ue,''  e.  g.# 
Propine,  CHfCXHa. 

D*  Diolefin  Series,  contaioing  two  pairs  of  doubly -linked  car- 
bon atoms.  Algebraic  formnia,  CnH^n-^s,  isomeric  with  the  members 
of  the  acetylene  series.  Their  names  terminate  in  "diene,"  e,  g., 
Propadiene,  CHs:C:CH.. 

E,  Olefin-acetylene  Series,  containing  both  doubly-  and  trebly- 
linked  carbon  atoms.  Gent'ral  formula,  Cnlhn~4'  Their  names  ter- 
minate  in  "one/'  eg,,  Butone,  H^CiCH.CCH. 

F,  Diacetylene  Series,  containing  two  pairs  of  trebly- linked 
carbon  atoms.  Algpbnvic  fonrnihi,  CrJi2«-6.  Their  names  are  con- 
straeted  by  prefixing  the  sylhible  "di"  to  the  name  of  the  hydrocar- 
bon of  series  C,  from  which  they  are  derivable  by  fusion  and  elimi- 
nation  of  U*  or  its  equivalent,  e.  g.,  Diacctyleoe,  HCiC.C-CH.  The 
sixth  terms,  of  which  there  are  two  isomeres:  Dipropargyl,  HCfC.CHs.- 
CHa.GCe.    and    Dimethyl   diacetylene,    R.C.CiC.ClC.Cn^,   are    iso- 

^^th  benxene,  the  most  important  of  the  closed  chain  Lydro- 


SATURATED  COMPOUNDS  — METHANE  SERIES. 

HYDROCARBONS. 

The  satitrated  hydrocarbons  at  present  known  extend  in  unbroken 
series  from  methane,  CHji,  to  tetracosane,  C24H50;  and  above  that 
somr  members  are  known  as  high  as  dimyricyl,  Co«iHi22.  The  alge- 
braic formula  of  the  series  is  CnH2»4^2.  They  are  called  paraffins 
beeaose  of  their  great  stabilitj^  (parwm=little,  affinift:=SLf^nity) ;  and 
1^ 


I 


274  MANUAL    OF    CHEMISTRY 

also  alkanes.     They  are  also  considered  as  the  hydrids  of  the  alco- 
holic radicals,  C»H2n+i,  methyl,  ethyl,  etc.,  which  are  called  alkyls. 

In  the  higher  terms  of  the  series,  above  the  third,  there  exist  two 
or  more  isomeres,  increasing  progressively  in  number  with  an  in- 
creasing number  of  carbon  atoms.  Thus  there  are  three  having  the 
empirical  formula,  C5H12: 

(1)  CH3.CH2.CH2.CH2.CH3,  (3)  CHaX 

(2)  CHaXpTT  pxr    pxT  ^„^  CH3— C.CHj. 
CH3/^^-^^2.CH3,               and,                    ^^^y 

Hydrocarbons  and  their  derivatives  having  the  "unbranched" 
structure  shown  in  formula  (1)  above,  are  designated  as  "normal" 
compounds;  those  derived  from  (2)  are  called  "iso"  compounds; 
and  those  derived  from  (3)  "meso"  compounds. 

The  number  of  possible  isomeres  increases  rapidly  with  an  in- 
creasing number  of  carbon  atoms.  It  has  been  calculated  that  the 
number  of  possible  isomeres  with  increasing  values  of  n  are  as 
follows  : 


n  =  l 

n  =  2 

n=3 

n  =  4 

n  =  5 

n  =  6 

1 

1 

1 

2 

3 

5 

n  =  7 

n  =  8 

n  =  9 

n  =  10 

n=ll 

n  =  12 

9 

18 

35 

75 

159 

357 

Many  of  these  hydrocarbons  exist  in  nature,  in  petroleum,  and  in 
the  gases  accompanying  it.  They  may  be  produced  by  the  follow- 
ing general  reactions: 

(1)  By  the  action  of  finely-divided  zinc,  silver  or  copper,  or  of 
sodium  either  alone,  at  elevated  temperatures,  or  in  the  presence  of 
H2O,  upon  the  corresponding  iodids  :  2C2H5l+Zn2+2H20— ZnH202+ 
ZUI2+2C2H6,  or,  2C2H5l+Na2=2NaI+C4Hio. 

(2)  By  electrolysis  of  the  corresponding  fatty  acid  :  202H402= 
2CO2+C2H6+H2. 

(3)  By  the  action  of  the  organo-zincic  derivative  upon  the  iodid 
of  the  alcoholic  radical,  upon  the  corresponding  olefin  iodid,  or  upon 
the  allylic  iodid  (p.  426). 

(4)  By  the  action  of  highly  concentrated  hydriodic  acid  at  275°- 
300°  (527°~572°  F.)  upon  hydrocarbons  of  the  ethene  and  ethine 
series,  upon  alcohols,  amins,  etc.  This  is  a  method  of  hydrogenation 
applicable  in  many  other  cases.  See  p.  186. 

(5)  By  the  destructive  distillation  of  many  organic  substances. 
General  Properties. — They  are  gaseous,  liquid,  or  solid,  and  have 
sp.  gr.  and  boiling  points  increasing  with  the  number  of  C  atoms. 
The  first  four  members  are  gaseous  at  the  ordinary  temperature,  those 
above  C15H32  are  crystalline  solids;  the  intermediate  ones  are  color- 
less liquids.     They  are  lighter  than  H2O,  neutral,  insoluble  in  H2O, 


HYDROCARBONS  275 

soluble  in  alcohol,  ether,  and  in  liquid  hydrocarbons.    Their  odor  is 
faint  and  not  nnpleasant. 

Chlorin  and  broinin  decompose  them,  with  formation  of  products 
of  substitution.  They  are  inflammable  and  bum  with  a  luminous 
flame.    Nitric  acid  forms  nitro- derivatives  with  the  higher  terms. 

The  formulae  given  above  (p.  274)  show  that  these  hydrocarbons  are 
made  up  of  groups:  — HC3,  called  methyl,  =CH2,  methylene,  =CH, 
xnethenyl  or  methine,  and  =C  atoms,  all  of  the  free  valences  of  each 
of  which  are  satisfied  by  attachment  to  other  C  atoms.   In  the  molecu- 
lar structure  of  their  derivatives,  these  several  fractions  of  the  hydro- 
carbons are  modified,  according  to  their  valence -capacity,  by  substitu- 
tion or  by  interpolation.    Thus,  by  substitution  the  groups:   — CHBr2, 
=CO,  and  =CC1  are  derived  from  — CH3,  =CH2,  and=CH  respec- 
tively, and  by  interpolation  the  groups — CH20H,=CH0H,  and=COH. 
Methyl  Hydrid — Methane — Marsh-gas — Light  carhuretted  hydrO' 
gtn — Fire-damp — CEU — 16 — is  given  off  in  swamps  as  a  product  of 
decomposition  of  vegetable  matter,  in  coal  mines,  and  in  the  gases 
issuing  from  the  earth  in  the  vicinity  of  petroleum  deposits.     It  is 
also  fonned  during  putrefaction  of  protein  bodies  and  fermentation  of 
carbohydrates.    *  From    these  origins   it   exists   in    intestinal   gases, 
sometimes  to  the  extent  of  26.5  per  cent.     Coal-gas  contains  it  in 
tbe  proportion  of  36-50  per  cent.     It  may  be  prepared  by  strongly 
Wting  a  mixture  of  sodium  acetate  with  sodium  hydroxid  and  quick- 
lime.   Its  complete  synthesis,  which  is  of  theoretic  interest,  may  be 
effected  in   several  ways:    (1)   Carbon  disulfid  is  first  produced  by 
passing  vapor  of  sulfur  over  coal,  heated  to  redness  :   C+S2=CS2. 
This  may  either  be  passed,  along  with  hydrogen  sulfid,  over  red- 
Wcop])J»r,  when:  CS2+2H2S+8Cu=CHi+4Cu2S,  or,  (2)  it  may  be 
^•onverted  into  carbon  tetraehlorid  by  the  reaction:  CS2+3Cl2=CCU+ 
^b;  and   this  reduced  by  nascent  hydrogen:    CCU+4H2^CH4+ 
fHCl.    (3)  Carbon  monoxid,  prepared  by  heating  carbon  in  a  lim- 
ited quantity  of  air,  is  reduced  by  hydrogen  when  the  two  are  treated 
^ththe  induced  electric  current:   CO+3H2=CH4+H20.     (4)  Alu- 
iDinium  carbid  is  decomposed  by  water  according  to  the  equation: 
CjAl4+i2H20=3CH4+2Al2(OH)6. 

It  is  a  colorless,  odorless,  tasteless  gas;  very  sparingly  soluble  in 

B2O;  8p.  gr.  0.559A.     At  high  temperatures,  it  is  decomposed  into  C 

•nd  H.    It  burns  in  air  with  a  pale  yellow  flame.     Mixed  with  air  or 

0  it  explodes  violently  on  contact  with  flame,  producing  water  and 

carbon  dioxid;  the  latter  constituting  the  after-damp  of  miners.     It 

iinot  affected  by  CI  in  the  dark,  but,  under  the  influence  of  diffuse 

daylight,  one  or  more  of  the  H  atoms  are  displaced  by  an  equivalent 

qoantity  of  CI.     In  direct  sunlight  the  substitution  is  accompanied 

by  an  explosion. 


276 


MANUAL    OF    CHEMISTRY 


Petroleum-— Crude  petruleiiRi  varies  in  <*oIor  from  a  faintly  j-el* 
lowish  tinge  to  a  dark  brown,  n*^arly  blfiok,  with  greenish  refleetiot]?. 
The  lighter-colored  varieties  are  limpid,  and  the  more  highly  colored 
of  the  eonst^tency  of  thin  syrup.  The  sp.  gr,  varies  from  0.74  to 
0.92.  Crude  petroleums  consist  of  normal  paraffins  (the  lowest  terms 
of  the  series  being  found  in  the  gase.*^  accompanying  petroletmi  aitd 
held  in  solution  by  the  oil  under  the  pressure  it  supports  in  naturnl 
pockets),  besides  hydrocarbons  of  the  olefin »  paraffene,  and  benzene 
series.  They  also  contain  varjing  quantities  of  sulfur  compounds, 
which  communicate  a  disgusting  odor  to  some  oils. 

The  crude  oil  is  highly  inflammable,  usually  highly  colored,  and 
is  prepared  for  its  multitudinous  uses  in  the  arts  by  the  processes  of 
distillation  and  refining.  The  products  of  lowest  boiling  point  are 
usually  consumed,  but  are  sometimes  condensed. 

The  principal  products  of  petroleum  are  :  Cyniogene,  boils  at  O*' 
(32^  P.),  used  in  ice  machines;  Rhigolene,  a  highly  inflammable 
liquid,  sp.  gr.  about  0.60,  boils  at  about  20*^  (68*^  PJ,  used  to  pro- 
duce cold  by  its  rapid  evaporation.  Petroleum  ether,  boils  at  40°-70^ 
(104'''158''  F.),  used  as  a  solveut.  Gasolene,  boils  from  45 '^  (113°  FJ 
to  76°  (168.8*^  P.),  used  as  a  fuel  and  for  the  mannfaetui'c  of  *'atp 
gas."  Naphtha,  divided  into  three  grades,  C,  B,  and  A,  boils  from 
82.2"*  {180''  F.)  to  148.8°  (300°  F J,  used  as  a  solvent  for  fats,  etc., 
and  in  the  manufacture  of  ^- water  gas."  Soraetimes  called  '■  safety 
oil."  Benzine,  or  benzolene,  boils  from  148°  (298°  F.)  to  160'' 
(320°  F,)»  used  as  a  sdlvcnt  in  making  paints  and  varnishes.  The 
most  important  prrKlnct  of  petroleum  is  tliat  portion  which  distils 
between  176°  (349°  FJ  and  218°  (424^  P.),  and  which  constitutes 
kerosene  and  other  oils  used  for  burning  in  lamps.  An  oil  to  be 
safely  used  for  burning  in  lauips  sliould  not  "flash,"  or  give  off  in- 
flammable vapor,  below  37.4°  (100°  P  ),  und  should  not  bum  at 
temperatures  below  149°  (3TO°  P.).  The  better  grades  of  kerosene 
have  a  flash  point  of  from  110°  F,  to  150°  F. 

Prom  the  residue  remaining  after  the  separation  of  the  kero- 
sene, many  other  products  are  obtained.  Lubricating  oils,  of  too 
high  boiling-point  for  use  in  lamps.  Paraffin,  a  white,  crj'stalliTie 
solid,  fusible  at  45°-65°  (113°-149°  F.},  which  is  used  in  the  arts  for 
a  variety  of  purposes  formerly  served  by  wax,  such  as  the  manufac- 
ture of  candles.  In  the  laboratory  it  is  very  useful  for  coating  the 
glass  stoppers  of  bottles,  and  for  other  purposes,  as  it  is  not  affected 
by  acids  or  by  alkalies.  It  is  odorless,  tasteless,  insuhible  in  H2O 
and  in  cold  alcohol;  soluble  in  boiling  ah^ohol  and  in  ether,  fatty  and 
volatile  oils  and  mineral  oils.  It  is  also  obtaiucd  by  the  distillation 
of  certain  varieties  of  coal,  and  is  found  in  nature  in  fossil  wax  or 
ozocerite. 


HALOID    DERIVATIVES    OF    THE    PARAFFINS 


277 


I 


The  proJin^ta  ^Liawn  as  vaseline,  cosmolinc,  etc.,  are  mix- 
tures of  purafBa  aud  the  heavier  petroleum  oils.  Their  consistency 
depends  apou  the  relative  proportion  of  the  higher  paraffins,  of 
increasing  fusing -point,  which  they  contain,  froio  the  oily  petro- 
latum liquidum  (U,  SJ,  to  the  hard  petrolatum  durum  (U.  SJ. 
Like  petroleum  itself,  its  various  commercial  derivatives  are  not 
definite  compounds ,  but  mixtures  of  the  hydrocarbons  of  this  series. 

HALOID    DERIVATIVES   OF     THE   PARAFFINS. 

i 

By  the  action  of  CI  or  Br,  up(*u  the  paraffins,  or  by  the  action  of 
HCl,  HBr  or  HI  upon  the  corresponding  hydroxids,  the  monoliydric 
alcohols  (p.  286),  compounds  are  ohttiined  iu  which  one  of  the  H  atoms 
of  the  hydrocarbon  has  been  replaced  by  an  atom  of  Ul,  Br  or  I; 
CjH«+Br2=C2H5Br+HBr,  or  C2H50H+HC1-=C2H5(J1+H20.  Or  they 
are  more  readily  obtained  by  the  action  of  the  phosphorus  halids,  or  of 
the  halogen  in  presence  of  phosphorus  upon  the  ujonuhydrie  alcohols: 
Cai,CH30H+PCU-=€H3.CH2Cl+POCt3+HCL  These  monohalogen 
paraffins^  or  haloid  ethers,  or  haloid  esters  (p.  358),  or  alkyl  halidSt 
may  also  be  considered  as  the  chlorids,  etc.,  of  the  alcoholic  radicals, 
methyl,  etc. 

These  compounds  are  of  great  service  for  the  introduction  of  their 
alkyls  mto  other  molecules.  Thus,  benzene  aud  methyl  chlorid  form 
metliyl  benzene:    CeHe+CHsCl^CeHs.CHa+HUl. 

Caustic  potash  or  soda  in  alcoholic  solution  splits  oflf  the  halogen 
«ftd water,  with  formation  of  an  unsaturated  hydrocarbon:  CHa^CH^Br 
+KH0=CH2:CHn+KBr+H2O.  Heated  with  aqueous  potash  the 
Haloid  esters  produce  the  corresponding  alcohols:  CHa.CHsBrH-KHO 
=CH:i.CHjOH  +  KBr.  Heated  with  alcoholic  solution  of  potassium 
cranidat  100*",  the  haloid  esters  produce  the  alkyl  cyanids:  CHa-CHal 
^K<.^X=CH3.CHj.CN+KI  (p.  393).  They  also  combine  with  am- 
BJonia  to  form  amins  (p.  379):    CHsCl+NHa^^CHa.NH^.Cl 

By  the  further  action  of  the  halogen  upon  the  paraffin,  products  of 
H'Rher  substitution  are  formed.  Thus,  from  methane :  methylene  chlorid, 
^'SiCl-,  methenyl  chlorid,  CHCI3,  aud  carbon  tetrachlorid,  CCI4*  In 
tb'  dihalogen  paraffins  above  the  first  the  two  halogen  atoms  may  be 
^^^ehed  either  to  different  or  to  the  same  carbon  atom.  The  former 
•^•ass  may  be  considered  as  the  neutral  haloid  esters  of  the  glycols,  or 
*mric  alcohols  (pp.  294,  363):  CH2CI2X7H2CI2,  as  the  monohalogen 
Paraffins  are  the  haloid  esters  of  the  monohydric  alcohols.  They  are 
^otained  by  the  action  of  the  halogens  upon  the  olefins  (p.  424): 
'^B3iCH2+l2=CH2l.CH2l,  and  from  them  the  glycols  are  obtained. 
Aflose  dihalogen  paraffins  in  which  the  two  halogen  atoms  are  attached 
^  the  same  carbon  atom,  are  known  as  aldehyde  halids  if  the  carbon 


278 


MANUAL    OF    CHEMISTKY 


atom  be  terminal  as  in  CH3.CH2.CHCI2,  and  as  ketone  halids  if  it  be 
intermediate,  as  in  CH3.CCI2.CH3,  from  the  resemblance  of  their  struc- 
tare  to  those  of  the  aldehydes  and  ketones(pp.  300,  307)  respectively, 
and  from  the  fact  that  they  are  obtained  by  the  action  of  phosphorus 
halids  upon  those  substances:  CH3.CHO+PCl5=^CH3.CHCl2H-POCb, 
and  CH3.CO.CH3+PCl5=CH3.CCh.CH,+  POCl3,  The  two  classes  are 
also  disfiiigiiished  as  symmetrical  and  un symmetrical  dihalids. 

Nascent  hydrogen  reduces  all  of  the  halogen  derivatives  to  the 
parent  hydrocarbon:  CHCl3+3H3=CH*+3HCL 

Methyl  Chlorid — CH^Ct^OO.S — is  a  colorless  gas,  slightly  soluble 
in  H2O,  and  having  a  sweetish  taste  and  odor.  It  is  prepared  com- 
mercially by  heating  trimetliyljinnnoninm  chlorid  {obtiuned  by  dis- 
tilling beet  sugar  molasses):  3N(CH:j)3HCl:=2CH3Cl+2K(CH»)3+ 
NH2CH3+HOL  Ir  may  be  mnden^ed  to  a  liquid  which  boils  at  — 22^ 
( — 7.6'^  FJ,  in  whieb  form  it  is  used  in  i(*e  mac^hine^,  as  a  spray  in 
neuralgia,  and  as  an  aniFsthetic;  for  the  latter  uses  either  alone  or 
mixed  with  CHCls^CJiioO,  or  Cillr.Cl.  It  burns  wilh  a  greenish 
flame. 

Dichlormethane — Methene  chlorid — Methylene  chlorid— Chloro- 
mcthyl — Monochlof methyl  chlond— Cll^Clt; — So — is  <>btained  by  the 
action  of  CI  upon  CH^,  and  by  the  reduction  of  CHL'b  by  nascent 
hydrogen. 

It  is  a  colorless,  oily  liquid^  boils  at  40°  (104°  Fj;  sp.  gr.  1.36 
its  odor  is  similar  to  that  of  chloroform;  it  is  very  slightly  soluble  in 
H2O  and  is  not  inflaumiable.  It  has  been  used  as  an  anesthetic,  but 
has  been  discarded  as  being  less  safe  than  chloroform, 

Trichlormethane — ^Methenyl  chlorid — Formyl  chlorid^-Dichlor- 
methyl  chlorid— Chloroform— Chloroformum  (U.  8,;  Br. )— CHCli 
^-120  5^is  obtained  by  heati^ng  in  a  eapaeious  still,  35-40  litms  (9-11 
galL)  of  H2O,  adding  5  kilos  (11  lbs,)  of  recently  slacked  lime  and 
10  kilos  (22  IbsJ  of  chlorid  of  lime;  2,5  kilos  (4  qts.)  of  alcohol  are 
then  added  and  the  temperature  quickly  raised  until  the  product 
begins  to  distil,  when  the  fire  is  withdrawn,  heat  being  again  applied 
toward  the  end  of  the  reaction.  The  crude  chloroform  so  obtained  is 
purified,  first  by  agitation  with  H2SO4  then  by  mixing  with  alcohol 
and  recently  ignited  potassiuna  carbonate,  and  distilling  the  mixture. 

Chloroform  is  now  extensively  manufactured  by  the  action  of 
bleaching  powder  upon  acetone,  the  reaction  being  expressed  by  the 
equation  :  2CO(CH3)2  +  6CaCi(0CI)  =  2CHCLi  +  2Ca(HO)3  +  (CH3- 
COO)2Ca+3CaCl2. 

It  is  best  obtained  pure  by  heating  chloral  hydrate  with  an  alkali: 
C2HCb(OH)2+KHO=CHCl3+HCOOK  +  H.O. 

It  is  a  colorless,  volatile  liquid^  having  a  strong,  agreeable,  ether- 
eal odor^  and  a  sweet  taste;   ap.  gr.  1,497;  very  sparingly  soluble  in 


u 


HALOID    DERIVATIVES   OF    THE    PARAFFINS 


279 


H2O;  miscible  with  Bl<r*ohol  atiil  etlier  m  ull  proportions;  boils  at 
60,8*^  (141.4*^  FJ.  It  is  a  good  solvent  for  umny  substances  iusol- 
uble  in  Fl-iO,  such  as  phosphorus,  iodio,  fats,  resins^  caoiitclioue, 
gutta-percha  and  the  alkidoids. 

It  ignites  with  diffirnlty,  but  bnrns  from  a  wick  with  a  smoky,  red 
ftame,  bordered  with  green.  It  is  not  ai^ted  on  by  H-8O4,  except  after 
long  contact,  when  HCl  is  given  off.  In  direct  suiiliglit  CI  couveits 
it  into  CCI4  and  HCL  The  alkalies  in  aqneoos  solution  do  not  act 
upon  it,  but  when  heated  with  them  in  alcoholic  solution,  it  is  decora- 
posed  with  forniation  of  chlorid  and  formate  of  the  alkaline  inetah 
CHCl3+4KHO=II.COOK+3KCl+2H20.  When  perfectly  pure  it  is 
not  altered  by  exi>osnre  to  light;  but  if  it  contain  compounds  of  N» 
even  in  very  minute  quantity,  it  is  gradually  decomposed  by  solar 
action  into  HCU  CI  and  othf*r  substances.  When  used  as  an  anaesthetic 
chloroform  should  not  be  colored  by  agitation  with  concentrated, 
colorless  sulfuric  acid,  and  should  color  the  latter  only  faintly  yellow, 
or  not  at  all;  and  when  it  is  evaporated  the  remaining  film  of  mois- 
ture should  have  no  taste  or  odor  other  than  those  of  chloroform. 

Analytical  Characters. — {1)  Add  a  Itttle  alcoholic  solution  of 
potash  and  2-3  drops  of  auilin  and  warm:  the  disagi'ceable  odor  of 
isobenzonitril  (q.  v.)  is  produced.  (2)  Vapor  of  CHCb,  when  passed 
through  a  red-hot  tube,  is  decomposed  with  formation  of  HCI  and 
CI,  the  former  of  which  is  recognized  by  the  production  of  a  white 
ppt.,  soluble  in  ammonium  hydroxid,  in  an  acid  solution  of  silver 
nitrate.  This  test  does  not  afford  reliable  results  when  the  substance 
tested  contains  a  free  acid  and  chlorids.  (3)  Dissolve  about  0.01  gm, 
of  P  naphtbol  in  a  small  quantity  of  KHO  solution,  warm,  and  add 
the  suspected  liquid;  a  blue  color  is  produced,  (4)  Add  about  0.3 
grm.  resorcinol  in  solution,  and  3  gtts,  KaHO  solution  and  boil 
strongly.  In  the  presence  of  CFIClri  a  yellowish -red  color  is  produced^ 
and  the  liquid  exhiliits  a  beautiful  yellow -green  fluorescence, 

Toxicology.^ — The  action  of  chloroform  varies  as  it  is  taken  by  the 
stomach  or  by  inhalation.  In  the  former  case,  owing  to  its  insolu- 
bility, but  Uttle  is  absorbed,  and  the  principal  action  is  the  local  irri- 
tation of  the  mucous  surfaces.  Recovery  has  followed  a  dose  of  four 
ounces,  and  death  has  been  caused  by  one  drachm,  taken  into  the 
stomach »  Chloroform  vapor  acts  much  more  energetically,  and  seems 
to  owe  its  potency  for  evil  to  it^  paralyzing  influence  upon  the  res- 
piratory nerve  centers,  and  upon  the  cardiac  ganglia.  While  persons 
suflfering  from  heart  disease  are  particularly  susceptible  to  the  para- 
lyzing effect  of  chloroform  vapor,  there  are  many  cases  recorded  of 
death  from  the  inhalation  of  small  quantities,  properly  diluted,  in 
which  no  heart  lesion  wtis  found  upon  a  post-mortem  examination. 
Chloroform  is  apparently  not  altered  in  the  system. 


280 


MANUAL  OF  rriEMiSTny 


No  chemical  antidote  f or  cliloraforni  is  known.  When  it  has  been 
swallowed,  stomaeh -lavage  and  emetiej^  are  iiidieatrd;  when  taken 
by  inhalation,  a  free  circulation  of  air  ahonld  be  eslablisbed  ab(mt  the 
face;  artificial  respiration  and  the  application  of  the  induced  current 
to  the  sides  of  the  neek  and  epigastrium  should  be  resorted  to. 

The  nature  of  the  poison  is  usually  revealed  at  the  autopsy  by  it» 
peculiar  odor,  which  is  most  noticeable  on  opening  the  cranial  and 
thoracic  cavities.  In  a  toxicological  analysis,  chloroform  is  to  be 
sought  for  especially  in  the  lungs  and  blood.  These  are  placed  in  a 
flask;  if  acid,  neutralized  with  sodium  carbonate,  and  subjected  to 
distillation  at  the  temperature  of  the  water- bath.  The  vapors  are 
passed  through  a  tube  of  difficultly  fusible  glass;  at  first  the  tube  is 
heated  to  redness  for  about  an  inch  of  its  length,  and  test  No,  2 
applied  to  the  issuing  gas.  The  tube  is  then  allowed  to  cool,  and  the 
distillate  collected  in  a  pointed  tube,  from  the  point  of  which  any 
CHCI3  is  removed  by  a  pipette  and  tested  according  to  Nos.  1,  3  and 
4  above. 

Carbon  Tetrachlorid — Ghlorocarbon — CCU — 154 — is  formed  by  the 
prolonged  action,  in  sunlight,  of  CI  upon  CH3CI  or  CHClj;  or  more 
rapidly ♦  by  passing  CI,  charged  with  the  vapor  of  carbon  disullid, 
Ihrough  a  red-hot  tube,  and  purifying  the  product. 

It  is  a  colorless,  oily  liquid,  insoluble  in  H^O;  soluble  in  alcohol 
and  in  ether;  sp,  gr.  1.56;  boils  at  78°  (172.4'^  F.).  Its  vapor  is 
decomposed  at  a  red  heat  into  a  mixture  of  the  dichlorid,  C^CU,  tri- 
chloride CjClfl,  and  free  CI. 

Methyl  Bromid— rCHsBr — 95. — A  colorless  liquid;  sp.  gr.  1.664; 
boils  at  13"^  (55.4°  P.);  formed  by  the  combined  action  of  P  and 
Br  on  methyl  liydroxid. 

Tribrommethane  — Dihromomeihijl  b  ro  mid  —  Met  hen  yl  hromid — 
Formal  hromid — Bromoforin— CUBr^.Br^ — 253^is  prepared  by  grad- 
ually adding  Br  to  a  cold  solution  of  KHO  in  methyl  alcohol  until 
the  liquid  begins  to  be  colored;  and  i;ectifying  over  CaCl2. 

A  colorless,  aromatic,  sweet  liquid;  sp.  ^.  2,13;  boils  at  150°— 
152*'  (302'^-306''Fj;  solidifies  at —9''  (15.8*^.);  sparingly  soluble  in 
H2O;  soluble  in  alcohol  and  ether.  Boiled  with  alcoholic  KHO  it  i» 
decomposed  in  the  same  way  as  is  CHCI3, 

Its  physiological  action  is  similar  to  that  of  CHCla.  It  occurs  as 
an  impurity  of  commercial  Br»  accompanied  by  carbon  tetrabroniid, 
CBn. 

Methyl  lodid— CH3I— 142— a  colorless  liquid,  sp.  gr.  2,237;  boila 
at  45°  (113^  F.);  burns  with  difflculty,  producing  violet  vapor  of 
iodin.  It  is  prepared  by  a  process  similnr  to  that  for  obtaining  the 
broraid,  and  is  used  in  the  anilin  industry, 

Triiodome thane  —  Dnodomtfhtjl  iodld -^ Mfihenyl  iodid  —  Formal 


HALOID    DERIVATIVES    OF    THE    PARAFFINS 


281 


fftdid — Iodoform  —  lodoformum,  U.S. —  CHI2I — 394,  — Formed  like 
CHCI3  aiid  OHBr:u  by  the  coiubiDed  action  of  KHO  and  tbe  habgeu 
iipoti  aleobol;  it  is  also  produced  by  the  action  of  I  upon  a  great 
fiiimber  of  organic  substances,  and  is  usually  prepared  by  beating  a 
niijchire  uf  nlkaline  carbonate,  H2O,  I  and  etbylic  alcohol,  and  purify* 
lug  the  prodin*t  by  rerrystalHzation  from  alcohol.  It  is  also  produced 
fi'oin  acetone  by  making  a  solution  containing  50  gm.  KI,  6  gm. 
acetone,  and  2  gni.  NaHO  in  2  L.  H2O  and  gradually  adding  a  dilute 
solution  of  KCIO3. 

Iodoform  is  a  solid,  crystalUzing  in  yellow,  hexagonal  plates, 
which  melt  at  120*^  (248^^  F.),  It  maybe  sablinied,  a  portion  being 
de<*oniposed.  It  is  insoluble  in  water,  acids  and  alkaline  solutions; 
fiohible  in  alcohol,  ether,  carbon  disulfide  and  the  fatty  and  essential 
oils;  the  Bohitious,  when  exposed  to  the  light,  undergo  decomposition 
and  assume  a  violet-red  color.  It  has  a  sweet  taste,  and  a  peculiar, 
jieuetrating  odor,  reseiribliiig,  when  the  vapor  is  largely  diluted  with 
air,  that  of  saffron.  When  heated  with  potash  a  portion  is  decom- 
posed into  formate  and  iodid,  while  another  portion  is  carried  off 
unaltered  with  the  aqueous  vapor.  It  contains  96.7%  of  its  weight 
of  iodin. 

Ethyl  Chlorid — Iltfdrochioric  or  mutiittic  ether — C2H5CI — 64,5. — 
A  roiorless,  ethereal  liquid;  boils  at  11°  (51.8°  F.);  obtained  by 
parsing  gaseous  IICI  through  etbylic  alcoliol  to  saturation,  and 
distiilitig  over  the  water-bath.  It  is  now  used  to  prmluce  cold  by 
spraying.     Tlie  liquid  and  vapor  are  readily  infiamrnable.  * 

By  the  continued  action  of  CI  in  the  sunshine  upon  ethyl  chlorid, 
or  upon  etbene  chlorid,  Oillt.Cb,  a  white,  crystalline  solid,  Hexa- 
chlorethanc  or  carbon  trichlorid,  C^CIe,  is  produced.  It  is  insol- 
uble in  H2O,  soluble  in  alcohol  and  in  ether,  has  an  aromatic  odor, 
fus<*8  at  IfW'*  (^(f  F.),  and  boils  at  182''  (359.6°  F.). 

Ethyl  BTomid—Iifftlt'obromic  ether  —  C^H^Br  **  109 — A  colorless^ 
rtliereal  liquid;  boils  at  40.7^  (105.3^  FJ  obtained  by  the  combined 
action  of  P  and  Br  on  etbylic  alcohol*  It  is  now  extensively  used  as 
an  anaBsthetic  in  minor  surgery. 

Ethyl  Iodid — Hydrhdiv  ether — C2H5I — 156 — ^is  prepared  by  placing 
abeolnte  alcohol  and  P  in  a  vessel  surrounded  by  a  freezing  tnixture 
and  gradually  adding  I,  When  the  action  has  ceased,  the  liquid  is 
decanted,  distilled  over  the  water* bath  and  the  distillate  washed  and 
rectified. 

It  is  a  colorless  liquid;  boils  at  72.2*^  (162*^  F.);  has  a  powerful, 
ethereal  odor;  burns  with  difficulty.  It  is  largely  used  in  the  anilin 
industry* 

[See  also  Esters  of  Glycols,  p.  363 J 


282 


MANUAL    OF    CflEMISTKY 


OXIDATION  PRODUCTS    OK   THE   PARAFFINS. 


Many  important  and  varied  classes  of  compounds  are  derivable 
from  the  paraffins  by  oxidation: 

One  of  these  may  be  considered  as  derived  from  the  hydrocarbon 
by  the  introduction  of  an  oxygen  atom  between  two  of  its  hydrocar- 
bon groups.  Thus  from  the  hydrocarbon  butane,  CH3.CH2.CH2.CH3 
we  may  derive  the  oxids  CH3.CH2.O.CH2.CH3  and  CH3.O.CH2.CH2.- 
CH3.  These  are  the  true  oxids  of  the  alkyls,  and  are  known  as  simple 
and  mixed  ethers,  according  as  the  oxygen  atom  is  symmetrically  or 
unsym metrically  introduced.  Or,  in  other  classes  of  compounds,  an 
oxygen  atom  may  be  interpolated  as  in  the  ethers,  and  one  or  more 
of  the  hydrocarbon  groups  may  be  also  oxidized.  In  this  manner 
compounds  of  very  diverse  nature  are  derived:  Esters,  such  as  ethyl 
acetate,  CH3.CO.O.CH2.CH3;  acid  anhydrids,  or  acidyl  oxids,  such 
as  acetic  anhydrid,  CH3.CO.O.CO.CH3;  certain  acids,  such  as  digly- 
oollic  acid,  COOH.CH2.O.CH2.COOH,  and  certain  dihydric  alcohols, 
such  as  diethylene  glycol,  CH2PH.CH2.O.CH2.CH2OH.  It  will  be 
more  convenient  to  consider  these  several  classes  of  (compounds  after 
having  discussed  the  other  oxidation  products. 

Pour  other  classes  are  more  closely  related  to  each  other.  They 
may  be  considered  as  being  derived  from  the  hydrocarbons  in  one  of 
two  ways;  either 

(1)  By  the  interpolation  or  substitution,  or  both,  of  an  oxygen 
atom  or  atoms  in  one  of  the  groups  CH3,  CH2,  or  CH  of  the  parent 
hydrocarbon  (see  formute  on  p.  283).     Thus: 

(Ho :C.H)' becomes  (H2:C.0.H)';    (0:C.H)'or  (0:C.O.H)' 
(H.C.H)"        *'         (H.C.O.H)"or  (C:0)  "   and 
(CH)'"  **         (C.O.Hr 

and  by  the  oxidation  of  a  single  group  in  the  hydrocarbon:   isopen- 
tane;  (CH3)2:CH.CH2.CH3  the  following  products  may  he  obtained: 


(CH3)2 
II 

CH 
I 
CH2 

I 
H2:C.0.H 
Primary 
Alcohol. 
Isobatyl 
Carbinol. 


(CH3)2  (CH3)2 


CH 
I 
CH2 

I 
0:C.H 
Aldehyde. 

Valeral- 
dehyde. 


CH 
I 
CH2 

I 
0:C.O.H 
Acid. 

Isovaler- 
ianic  Acid. 


(CH3)2 
II 

CH 

I 
H.C.O.H 

I 
CH3 

Secondary 

Alcohol. 

Methyl 

isopropyl 

Carbinol. 


(CH3)2 
II 

CH 

I 

C:0 
I 

CH3 
Ketone. 

Methyl 
isopropyl 
Ketone. 


(CH3)2 
II 

C.O.H 

I 
CH2 

I 
CH3 

Tertiary 
A  leohol. 
Dimethyl 

ethyl 
Carbinol. 


(2)  Or  these  compounds  may  be  considered  as  produced  by  the  sub- 
stitution of  hydroxyls  (OH),  for  one  or  more  of  the  hydrogen  atoms 
of  the  hydrocarbon,  it  being  remembered  that  when  a  substance  is  thus 


OXIDATION   PRODUCTS  OF  THE  PARAFFINS 


283 


Xirodaced  in  which  two  hydroxyls  are  attached  to  the  same  carbou 
atom,  water  separates,  except  under  the  circumstances  referred  to  on 
ptLge  269.  Thus  from  the  hydrocarbon:  propane,  CH8.CH2.CH3,  the 
following  products  may  be  derived  by  substitution  in  a  single  hy- 
drocarbon group  : 

CH3.CH2.C^Q|j=Primary  alcohol; 

CH3.CH2.C^^g  j^— H20=CH3.CH2.C^Q=Aldehyde ; 

CH3.CH2.C:(OH)3  -H20=CH3.CH2.C^Q^=Acid; 
■      CH3.(CH.OH).CH3=Secondary  alcohol; 

CH3.(C :  [0H]2 )  .CH3— H20=CH3.(C  :0).CH3=Ketone. 

When  the  number  of  hydroxyls  substituted  in  each  hydrocarbon 
^rroup  exceeds  one,  the  number  of  derivatives  increases  rapidly  with 
mn  increasing  number  of  C  atoms  in  the  parent  hydrocarbon.  Thus 
the  second  term  of  the  series,  CH3.CH3,  yields  nine  derivatives: 


I. 

II. 

m. 

OHjOH 

1 
CH, 

0H(0H)2               0:C.H 
1              -H20=      1 
CH3                            CH3 

C(0H)3               0:C.OH 
1           -H20=       1 
CH3                        CH, 

Bthylie 
Aleohol. 

Acetic 
Aldehyde. 

Aeetio 
Aeid. 

IV. 

V. 

VI. 

CH2OH 
CH2OH 

CH(0H)2 
CH2OH 

0:O.H 
-H20=        1 

HaiC.OH 

CH(0H)2                0:C.H 
1               -2H20=      1 
CH(0H)2                 0:C.H 

ethylene 
Glycol. 

Olycolyl 
Aldehyde. 

GlyoxaL 

vn 

VIII. 

IX. 

C(OH), 

1           — H20= 
CH2OH 

0:C.OH 

1 
H2:C.0H 

C(0H)3                0:C.OH 

-H20=       1                C(0H)3                 0:C.O 
CH(0H)2             HC^QH     ^(^gj^                 Q.^^ 

QlyeolUe 
Aoid. 

Qlyoxylio                                           Oxalic 
Add                                                Add. 

There  are  twenty -nine  possible  derivatives  of  the  third  hydro- 
carbon, CH3.CH2.CH3. 

The  four  classes  of  oxidation  products  under  consideration  are 
therefore  : 

A.  The  alcohols,  subdivided  into  (a)  Primary,  containing  the 
j^up— C<^Q^;  (6)  Secondary,  containing  the  group  =0<^Qg;  and  (c) 
Tertiary,  containing  the  group=C.OH; 

B.  The  aldehydes,  containing  the  group  — C<^jj ; 

C.  The  ketones,  containing  the  group=C=0;  and 

D.  The  carboxylic  acids,  conttiining  the  group  carboxyl :  — C<(oH' 


mi 


MANiTAL    OF    CHEMISTRY 


The  aldehydes  and  ketones  of  this  series  contain  no  double  link- 
ages between  carbon  ntoms,  and,  in  that  sense,  are  saturated  com- 
pounds,  but  they  form  pi't>ducts  of  addition,  and  in  that  sense  are 
unsaturated  (p.  269).    Thus 

2CH3.C^^+02==2CH3.C^g*^  orCH3,C^^+H2  =  CH3.c/™.  or 

CHs,C^g+NaHS0a  =  CH3.CH<^^^^j^,^.  or  CHaX^^  +  NH^ -:CH3.CH<^^^^_. 

and  CHa.CO.CH3  +  H2=CH3,CHOH.CH3,  But  it  is  not  to  be  in- 
ferred from  the  presence  of  a^^C^O  fifroup  in  a  molecule  that  the 
substance  can  form  products  of  addition  by  the  breaking  out  of  the 
double  linkage  between  C  and  O.  as  in  some  of  the  above  reactions. 
Many  compounds  containing  C0»  such  as  the  earboxylic  acids,  con- 
taining (0:C.Ori)^  do  not  do  so* 


ALCOHOLa— HYDEOCARBON    HYDROXIDS. 

These  substances  are  mainly  characterized  by  their  power  of 
entering  into  double  decomposition  with  acids  to  form  neutral  com- 
pounds, called  esters,  water  being  at  the  yiimi^  time  formed  at  the 
expense  of  both  alcohol  and  acid.  They  are  the  hydroKids  of  hy- 
drocarbon radicals,  the  alkyls,  and  as  such  resemble  the  metallic 
hydroxids,  while  the  esters  are  the  counterparts  of  the  metallic 

(C,H.Jo+(C,H30)}o=(Cg^O|}o+«}o 
Ethrl  lisrdroxfd.      Ac«ttc  ncid.       Etbyl  ac«tate.    Water. 


K|o+(C.H.O)|o_(C..H.O>Jo+HJo 


Fotuiiam    Acetic  ibcid. 
bydroxid. 


K 

Pot&Miam 


Water. 


Or  they  may  be  regarded  as  substances  derived  from  the  hydro- 
carbons by  the  substitution  of  one  or  more  hydroxyls  for  one  or  more 
hydrogen  atoms.  Alcohols  containing  one  OH  are  designated  as 
monoatomic  or  monohydricj  those  containing  two  OH  groups  are 
diatomic  or  dihydric,  etc.: 


CHjOH 

I 
CHa 

I 
CHj 

Propylle 
AkohoL 


CH3OH 

I 

I 
CH2OH 

Propyl 
Glycol, 
Moaoatomlo.  Diatomic. 


CH2OH 

I 

ceoH 

I 

CHjOH 

Qlycerol, 
Tri&tomie. 


CH2OH 

I 
{CH0H)2 
I 
CH.OH 

Ery  th  rol, 
T«tratomlc. 


CH2OH 

(CH0H)3 
I 
CH2OH 

ArAbftf*, 
FentAtomic. 


CHiOH 

I 
(CHOH)* 

i 
CH2OH 

MaDBitol, 
Hexmtomie. 


MONOATOMIC,  OR  MONOHYDRIC   ALCOHOLS. 


Beginning  with  the    third    member  of   the   series,  an  increasing 
number  of   isomei-es  of    the   higher   terms   are   known. 


ALCOHOLS— HYDROCARBON    HYDROXIBS 


285 


L  Some  of  tbesf*  alcohols  yield  on  oxidation ^  first,  an  aldeliyde 
containing  the  g^roup  (CHO)'  and  then  an  acid  containing  the  group 
(COOH)\  both  aldehyde  and  acid  containing  the  same  number  of 
carbon  atoms  as  the  alcohol.  These  alcohols  contain  the  character- 
izing gnmp  (CH^OH)",  and  are  called  primary  alcohols,  e.  g,,  ethylic 
aleohol:   CH3.CH2OH. 

IL  Other  raonoatomic  alcohols  yield  on  oxidation,  not  an  aldehyde 
or  an  acid,  but  a  ketone^  containing  the  group  (CO)''  and  the  same 
number  of  carbon  atoms  as  the  alcohol.  These  alcohols  contain  the 
characterizing  group  (CHOH)",  and  are  called  secondary  alcohols, 
or  isoalcohots,  e.  g.,  Isopropyl  alcohol:   CHa.CyHOH.CHa 

IIL  Still  other  alcohols  yield  on  oxidation  either  two  or  more 
acids,  or  an  acid  and  a  ketone,  whose  molecules  contain  a  less  number 
of  carbon  atoms  than  Hie  alcohol  from  which  they  were  derived. 
These  alcohols  contain  the  characterizing  gi-oup  (COH)"^,  and  are 
called  tertiary  alcohols,  e.  g.,  Tertiary  butyl  alcohol,  (CHsJa^  COH. 

The  monohydric  alcohols  are  also  the  hydroxids  of  the  alkyls 
(p.  274). 

Nomcnclaturc-^Names  of  alcohols  terminate  in  ol;  and  the  ter- 
mination ol  is  reserved  for  the  names  of  alcohols  and  of  phenols. 
The  "Geneva**  names  of  the  monohydric  alcohols  are  derived  from 
those  of  the  corresponding  hydnn-arbons  by  the  snbsfifution  of  the 
syllable  0/  for  the  terminal  ei  Thus  H.CH-jOH  is  Muthanol;  CHg.CHs- 
OH  ethanol;  CHa.CH2.CH20H,l-propanol;  ClI:,,CHOH,CH:i, 2 -pro- 
panoic etc. 

Kolbe*s  system  of  naming  the  monoatomic  alcohols  is  more  gener- 
ally followed.  It  refei-s  the  names  of  the  higher  alcohols  back  to  that 
of  the  first,  n.CH:;OH,  which  is  called  carbiool;  the  names  of  the 
radicals  conl;a!n''d  m  the  superior  homologues  being  prefixed  to  the 
word  ^^carhitior'  in  the  construction  of  their  names.  Thus  the  graphic 
forroul«e  and  carbinol  names  of  the  eight  possible  amylic  alcohols  are 
as  follows: 


Primary, 

(1)  CHa.CH,.CH2.CHj.CH20H 

Batyl  CarbltHJl. 
iNormfil  hmyUc  aJcsotiol) 

(2)  ^g')CH.CH..CHjOH 

t$oh%ityl  Cjirblnol. 

(Amy lie  lilcohol  of 

ftfrmtintatlonj 


(3) 


)CH.CH,OH 


CH, 

ScKTundAry  bntji  Ciirblno]. 
( Aetive  Amy  tic  nltrcihtil). 

CHsN 
(4)  CHr-C.CHiOH 

T«rtiiiry  butyl  Carbltiol. 


Blethrl  CftrblnoL 

Methyl  u  propyl  C*rblnoL 

(7)  CH,\^g^\cHOH 

Methyl  i**>pn>i>yl  Cftrbinol. 
Tertiarij. 

CHA 

(8)  ca^— C.OH 

Dimethyl  «tb]rt  C&rbiaol. 


286  MANUAL    OF    CHEMISTRY 

Of  the  above,  numbers  1,  5  and  6  are  derived  from  the  normal 
paraffin  (1,  page  274);  numbers  2,  3,  7  and  8  from  the  isoparaffin 
(2),  and  number  4  from  the  mesoparaffin  (3). 

Primary,  secondary  and  tertiary  alcohols  of  this  series,  containing^ 
less  than  nine  carbon  atoms,  may  be  distinguished  from  each  other  by 
conversion  into  nitrolic  acids  (p.  376).  The  three  classes  of  alcohols 
also  differ  in  the  facility  with  which  they  yield  esters  (p.  358)  with 
organic  acids.  Primary  alcohols  are  rapidly  esterified  in  large  amount^ 
secondary  alcohols  in  less  proportion,  and  more  slowly;  tertiary  alco- 
hols very  slowly  and  to  a  maximum  amount  of  about  7  per  cent. 

General  Methods  of  Formation. — (1)  By  the  action  of  freahly 
precipitated,  moist  silver  hydroxid  upon  the  haloid  esters:  C2H5T+ 
AgHO=C2H50H+AgI. 

(2)  By   the   saponification   of    their   esters    by   caustic   potash: 

C2H302.C2H5+KHO=C2H5.0H+C2H302K. 

(3)  Primary  alcohols  are  produced  by  the  reduction  of  aldehydes^ 
acid  chlorids,  or  anhydrids  (pp.  299,  352,  351) :  C2H5.CHO+H2= 
C2H5.CH2OH,  or  C2H5.C0C1  +  2H2  =  C2H6.CH20H+HC1,  or  (CHs- 
C0)20  +  2H2=CH3.CH20H+CH3.COOH. 

(4)  Bv  the  action  of  nitrous  acid  upon  the  primary  amins  (p.  379) ; 
CH3.CH2.NH2+HN02=CH3.CH20H+N2+H20. 

(5)  Secondary  alcohols  are  formed  by  the  reduction  of  ketones: 
CH3.CO.CH3+H2=CH3.CHOH.CH3. 

General  Reactions. — (1)  The  monohydric  alcohols  react  with 
metallic  Na  or  K  to  form  double  oxids,  called  alcoholates :  2CH3.CH2- 
OH+Na2=H20+2CH3.CH2.0.Na. 

(2)  When  heated  with  acids  tliey  form  esters  (p.  358):  CH3.CH2- 
OH  +  H2S04=  CH3.CH2.HSO4  +  H2O,  or  2CHn.(^H>0H  +  H2S04= 
(CH3.CH2)2S04+2H20. 

(3)  When  heated  with  hydracids  they  form  alkyl  halids:  CH3.CH2- 
0H+HC1=:CH3.CH2C1  +  H20;  which,  in  turn,  when  reduced  by 
nascent  hydrogen,  regenerate  the  parent  hydrocarbon:  CH3CH2CI  + 
H2=CH3.CH3+HC1. 

(4)  Their  products  of  oxidation  vary  according  as  they  are  primary, 
secondary  or  tertiary  (see  above):  Primary:  2CH3.CH20H  +  02= 
2CH3.CHO+2H2O,  andCH3.CH20H+02=CH3.COOH+H20:  *S^rf>«ci- 
ary;2CH3.CnOH.CH3+0>=2CH3.CO.CH3+2H20;T6'Wmri/;2(CH3)3.- 
COH+302==2CH:uCO.CH3  +  2H.COOH+2H20,  then  CH3.CO.CH3= 
202=CH3.COOH+C02+H20,  and  2H.(X)()H+02=2C02+2H20. 

Methyl  Hydroxid — Carbinol — Pf/roxyllr  tipirit — Methylic  alcohol 
—  Wood  spirit — H.CH20H=32 — may  he  formed  from  marsh -gas^ 
CH3H,  by  first  converting  it  into  the  iodid,  and  acting  upon  this  with 
potassium  hydroxid:  CH3l+KHO=KI-hH.CH20H.  It  is  usually  ob- 
tained by  the  destructive  distillation  of  wood.    The  pure  hydroxid  can 


ALCOHOLS— HV'DROCABBON    HTDROXID8 


287 


^ 


only  be  obtained  by  tlecomposing  a  crystalline  cmnponnd,  such  as 
methyl  oxalate*,  aud  rectityiiig^  tlu*  product  uutil  the  boiling* point  is 
eonsiaut  at  66.5*^  (Idl.T*^  F.  ).  Pure  raethyl  alcohol  is  a  colorless 
liquid,  having  an  ethereal  aud  alcoholic  odor»  and  a  sharp,  buriiiug 
taste:  sp.  gr  0,814  at  0*";  boils  at  aC.5''  (151,7''  P.);  burns  witli  a 
paJe  rtaine,  gi%4ng  less  heat  than  that  of  ethylic  alcohol  j  mixes  with 
water, alcohol, and  ether  in  all  proportions;  is  a  good  solvent  of  resinous 
ifubstaQces,  and  also  dissolves  sulfur,  phosphorus,  potnsh,  and  soda. 

Methyl  hydroxid  is  not  affected  by  exposure  to  air  nnder  ordinary 
cireumstances,  but  in  the  presence  of  platinum -black  it  is  oxidized^ 
with  formation  of  the  corresponding  aldehyde,  formaldehyde,  and 
aeid,  formic  acid.  Hot  HNOa  decomposes  it  with  formation  of  nitrous 
fumes,  formic  acid  and  methyl  nitrate.  It  is  acted  upon  by  IIoSOi  in  the 
same  way  as  ethyl  alcohol.  The  organic  acids  form  methyl  esters  with  it. 

Methylated  spirit  is  ethyl  alcohol  containing  one-ninth  its  vol- 
ume of  wood  spirit. 

Ethyl  Hydroxid — ^Ethylic  alcohol — Methyl  carbinol — Vinic  alco- 
hol—Alcohol—Spints  of  wine— CH3.CH2OH— 4G. 

Preparation. — Industrially  alcohol  and  alcoholic  liquids  are  ob- 
taiiied  from  substances  rich  in  starch  or  glucose. 

The  manufacture  of  alcohol  consists  of  three  distinct  processes: 
(1)  the  conversion  of  starch  into  sugar;  (2)  the  fermentation  of  the 
saccharine  liquid;  (3)  the  separation,  by  distillation,  of  the  alcohol 
formed  by  fermentation. 

The  raw  materials  for  the  first  process  are  malt  and  some  sub- 
stance (grain,  potatoes,  rice,  corn,  etc.)  containing  starch.  Malt  is 
barley  which  has  been  allowed  to  germinate,  and,  at  the  proper  stage 
of  gerrainatiion,  roasted.  During  this  growtli  tliere  is  developed  in 
the  barley  a  peculiar  nitrogenous  principle  called  diastase  (p,  605), 
The  starchy  material  is  mixed  with  a  suitable  quantity  of  malt  and 
water,  and  the  mass  maintained  at  a  temperature  of  G5'''-70^ 
(H9°-158^  P.)  for  two  to  three  liours,  during  which  the  diastase 
npidly  converts  the  starch  into  dextrin,  and  this  10  turn  into  mal- 
tose and  glucose  (p.  322). 

Thf*  saccharine  fluid,  or  wort,  obtained  in  the  first  process*  is 
drmwn  off»  cooled,  and  yeast  is  added.  As  a  result  of  the  growth  of 
tbe  yeast -plant,  a  complicated  series  of  chemical  changes  take  place, 
tbe  principal  one  of  which  is  tlie  splitting  up  of  the  glucose  into 
carbon  dioxid  and  alcohol  r  CflniMOo=2C3HsOH+2C02.  There  are 
formed  at  the  same  time  small  quantities  of  glycerol,  succinic  acid, 
aud  propylic,  butylic,  and  amylic  alcohols  (p.  600). 

An  aqueous  fluid  is  thus  obtained  which  contains  3-15  per  cent  of 
alcohol.  This  is  then  separated  hy  the  tliird  process,  that  of  distil- 
lation  and   rectification.    The  apparatus  used  for  this  purpose  has 


MANUAL    OF    CHEMISTRY 


been  so  far  perfected  that  by  a  siogle  distillation  an  alcohol  of  90-95 
per  L*ent  eaii  be  obtaiDed, 

III  some  oases  alcohol  is  prepared  from  fluids  rich  in  glucose,  such 
as  grape -jotce,  molasses*  syrup,  etc.  In  such  cases  the  first  process 
beeotoes  nnneoessary. 

Coniiuercial  alcohol  always  con  talus  H2O,  aud  when  pure  or 
absolute  alcohol  is  required,  the  coumiereial  product  tiiust  be  mixed 
with  some  hygroscopic  solid  substance,  such  as  quicklime,  from 
which  it  is  distilled  after  having  remained  in  contact  twenty -four 
hours. 

An  interesting  total  synthesis  of  alcohol  is  from  calcium  carbid, 
water  and  hydrogen.  Acetylene  is  formed  by  the  action  of  water 
upon  calcium  carbid,  CaCa  +  2H2O  =  CuILjOo  +  C2H2  ;  vapors  of 
acet^li'tie  aud  water,  heated  together  to  325°  (617°  FJ  unite  to  form 
«ildehyde»  C'jll2+H20^CnO,Cna ;  and  nascent  hydrogen  converts 
aldL'hyde  into  alcohol,  CH0.CH3+H2=CH2OH.CHn' 

Properties.— AUmJioI  is  a  thin,  colorless,  transparent  liquid,  hav- 
ing a  spirituous  odur  and  a  sharp,  burning  taste;  sp.  gr,  0.8095  at 
0"^,  0,7939  at  15^  (39°  Fj;  it  boils  at  TS.;3^  (173.3''  F.),  and  solidi- 
fies at  —130.5''  (—202.9°  F. ) .  At  temperatures  below  —90°  (—130'' 
F.)  it  is  viscous.  It  mixes  with  water  in  all  proportions,  the  union 
beintf  attended  by  elevation  in  temperature  and  contraction  in  volume 
(after  cooling  to  the  original  temperature).  It  also  attracts  moistore 
from  the  air  to  such  a  degree  that  absolute  alcohol  only  remains  such 
for  a  very  short  time  after  its  preparation.  It  is  to  this  power  of 
attracting  H2O  that  alcohol  owes  its  preservative  power  for  animal 
substances.  It  is  a  very  useful  solvent,  dissolving  a  number  of  gases, 
many  mineral  and  organic  acids  and  alkalies,  most  of  the  ehlorids 
and  carbonates,  some  of  the  nitrates,  and  the  essences  and  resins. 
The  sulfates  are  insoluble  in  alcohol.  Alcoholic  solutions  of  fixed 
niediciual  substances  are  called  tinctures  i  those  of  volatile  principles, 
spirits. 

The  action  of  oxygen  upon  alcohol  varies  according  to  the  con- 
ditions. Under  the  influence  of  energetic  o^tidants,  such  as  chromic 
acid,  or,  when  alcohol  is  burned  in  the  air,  the  oxidation  is  rapid 
and  complete,  and  is  attended  by  the  extrication  of  much  heat,  and 
the  formation  of  carbon  dioxid  and  water:  C2HfiO+302^2C02+ 
3H'iO.  Mixtures  of  air  and  vapor  of  alcohol  explode  upon  contact 
with  tiame.  If  a  less  active  oxidant  be  used,  such  as  platinum -black, 
or  by  the  action  of  atnjospheric  oxygen  at  low  temperatures,  a  simple 
oxidation  of  tlie  alcoholic  radical  takes  place,  with  formation  of  acetic 
aeid:  CHa.CIIuOH  +  O2  =^  CHa.COOn+HsO,  a  reaction  which  is 
utilized  in  the  nmnufactui'e  of  acetic  acid  and  vinegar.  If  the  oxida- 
tion be  still  further  limited,  aldehyde   is   formed  :   ^CH^j.CH^OH  + 


ALCOHOLS  —  HYDROCARBON    HYDROXmS 


289 


I 

I 


,=2CH3,CnO+2n^O.  Il:  vupur  of  elcobul  he  passed  tbrougli  a 
tube  filled  with  platinum  sponge  and  heated  to  redness,  or  if  a  coil 
of  heated  platinum  wive  be  introduced  into  an  atmosphere  of  alcohol 
vapor,  the  prodniitsof  oxidation  are  quite  numerous:  among  them  ore 
water,  ethylene »  aldi-hyde,  acetylene,  carbon  monoxid,  and  acetaL 
Heated  platinum  wire  introdueed  into  vapor  of  aleohol  (continues  to 
^low  by  the  heat  resulting  from  the  oxidation,  a  fact  which  has 
been  utilized  in  the  thermocautery. 

Chlorin  and  bromin  act  energetically  upon  aleoliol,  producing  a 
number  of  chlorinated  and  b ruminated  derivatives,  the  final  products 
being  chloral  and  hromal  (p.  HO").  If  the  action  of  CI  be  moderated ^ 
aldehyde  and  IICl  are  first  produced.  lodin  acts  quite  slowly  in  the 
cold,  but  old  snlutiousof  I  in  alcohol  (Tr.  iodin.)  are  found  to  contain 
HI,  ethyl  iodid,  and  other  imperfectly  studied  produet^si.  In  the 
presence  of  an  alkali,  I  acts  upon  alcohol  to  protiuce  iodoform.  Po- 
tAS»ium  and  sodium  dissoh-e  in  alcohtd  with  evolution  of  H;  upon 
cooling,  a  white  solid  crystallizes,  which  is  the  double  oxid  of  ethyl 
and  the  alkali  metal,  and  is  known  as  potassium  or  sodium  ethylate 
or  alcoholate.  Nitric  aeid,  aided  by  a  gentle  heat,  acts  violently 
upon  alcohol,  producing  nitrous  ether,  brown  fumes,  and  prod  nets  of 
oxidation.  (For  the  action  of  other  acids  upon  alcohol  see  the  cor- 
responding esters  and  the  ethers.)  The  hydroxids  of  the  alkali 
metals  dissolve  in  alcohol^  but  react  upon  it  slowly;  the  solution  turns 
brown  and  contains  an  acetate.  If  alcohol  be  gently  heateil  with 
HNO3  and  nitrate  of  silver  or  of  mercury,  a  gray  precipitate  falL^, 
which  is  silver  or  mercury  fulminate. 

Varieties. — It  octnirs  in  ditTerent  degrees  of  concentration:  absc- 
lute  alcohol  is  pure  alcohoU  CsReO.  It  is  not  purchasable,  and  must 
be  made  as  required.  The  so-called  absolute  alcohol  of  the  shops  1 1 
rarely  stronger  than  98  pt^r  cent.  Alcohol  (U.  S,),  sp,  gr.  0.820, 
contains  94  per  eeut.  by  volume,  and  spiritos  rectificatus  (BrJ,  sp. 
gr,  0.S38,  contains  84  per  cent.  This  is  the  ordinary  rectified  spirit 
used  in  the  arts.  Alcohol  dilutum  {U,  Sj^Spiritus  tenuior  (Br J, 
ap,  gr,  0.920,  used  in  the  prt^i^aration  of  tinctures,  contains  53  percent. 
It  i«  of  about  the  siime  strength  as  the  proof  spirit  of  commerce. 

Analytical  Characters, — (1)  Ileated  with  a  small  quantity  of  boIu- 
lion  of  potassium  dichromate  and  H'i^04,  the  liquid  assumes  an 
emeriild- green  color,  and,  if  the  quantity  of  OjIIsO  be  not  very 
amall,  the  peculiar  fruity  odor  of  aldehyde  is  developed.  (2)  Warmed 
aad  treated  with  a  few  drops  of  potash  solution  and  a  small  quantity 
of  iodin,  an  alcoholic  liquid  deposits  a  ytdlow,  crystalline  ppt,  of 
iodoform,  either  immediately  or  after  a  time.  (3)  If  HNO3  be  addinl 
to  a  liquid  containing  CjHuO,  nitrous  ether,  recognizable  by  its  odor, 
ia  given  off.     If  a  solution  of  mercurous  nitrate  with  excess  of  HNO3 


10 


290  MANUAL    OF    CHEMISTRY 

be  then  added,  and  the  mixture  heated,  a  further  evolution  of  nitrous 
ether  occurs,  and  a  yellow-gray  deposit  of  fulminating  mercury  is 
formed,  which  may  be  collected,  washed,  dried,  and  exploded.  (4) 
If  an  alcoholic  liquid  be  heated  for  a  few  moments  with  H2SO4  diluted 
with  H2O  and  distilled,  the  distillate,  on  treatment  with  H2SO4  and 
potassium  permanganate,  and  afterward  with  sodium  thiosulfate, 
yields  aldehyde,  which  may  be  recognized  by  the  production  of  a  vio- 
h  t  color  with  a  dilute  solution  of  fuchsin. 

None  of  the  above  reactions,  taken  singly,  is  characteristic  of 
alcohol. 

Alcohol  is  determined  quantitatively  in  simple  mixtures  of  alcohol 
and  water  by  determining  the  specific  gravity  and  referring  to  tables 
constructed  for  the  purpose.  In  alcoholic  beverages  100  cc.  of  the 
sample  is  distilled  until  75  cc.  have  passed  over,  the  distillate  is  then 
made  up  to  100  cc.  with  water,  and  the  sp.  gr.  determined. 

Alcoholic  Beverages. — These  may  be  divided  into  four  classes: 

I. — Those  prepared  by  the  fermentation  of  malted  grain — beers, 
ales  and  porters. 

n. — Those  prepared  by  the  fermentation  of  grape  juice — wines. 

ni. — Those  prepared  by  the  fermentation  of  the  juices  of  fruits 
other  than  the  grape — cider,  fruit-wines. 

IV. — Those  prepared  by  the  distillation  of  some  fermented  sac- 
charine liquid — ardent  spirits. 

Beer,  ale  and  porter  are  aqueous  infusions  or  decoctions  of  malted 
grain,  fermented  and  flavored  with  liops.  They  contain  all  of  the 
soluble  constituents  of  the  grain  and  hops,  plus  dextrins,  maltose, 
glucose,  alcohol  and  carbon  dioxid.  Their  alcoholic  content  varies 
from  1.5  to  9  per  cent  absolute  alcohol  by  weight.  They  contain  a 
considerable  proportion  of  nitrogenous  material  (0.4  to  1  percent  N), 
and  succinic,  lactic  and  acetic  acids.  The  most  serious  adulterations 
of  malt  liquors  consist  in  the  use  of  artificial  glucose  to  furnish  a  part 
of  the  alcohol,  and  in  the  use  of  strychnin,  picrotoxin,  picric  acid,  or 
other  bitter  principles  as  substitutes  for  hops. 

Wine  is  fermented  grape -juice.  The  expressed  juice,  called  the 
must,  contains  much  glucose,  the  fermentation  of  which  is  set  up  by 
yeast-plants  growing  upon  the  grape-skins.  In  red  wines  the  color  is 
produced  by  solution  of  the  coloring  matter  of  the  skins  in  the  accu- 
mulating alcohol.  The  same  agency  causes  the  precipitation  of  a  part 
of  the  hydropotassic  tartrate,  to  which  the  grape  or  wine  owes  its  tart- 
ness. Sweet  wines  are  made  from  grapes  rich  in  glucose,  and  by  arrest- 
ing the  fermentation  before  the  sugar  has  been  completely  decomposed. 
"Dry"  or  "brut"  wines,  which  are  not  sweet,  are  fermented  to  com- 
pletion. "Light"  wines  are  such  as  contain  less  than  12  per  cent  of 
alcohol,  although  they  sometimes  contain   as  much  as  16  per  cent. 


ALCOHOLS  — HYDROCARBON    HYDR0XID8  291 

They  are  the  products  of  temperate  climates,  and  include  the  clarets^ 
Sauternes,  Burgundies,  the  Rhine,  Moselle,  Australian,  Oreek  and 
Hungarian  wines,  and  the  wines  of  the  northern  portions  of  Spain,. 
Italy  and  the  United  States.  The  champagnes  also  belong  to  this  class,. 
and  are  sparkling  from  the  escape  of  carbon  dioxid,  produced  by  a^ 
secondary  fermentation  in  the  bottles,  and  held  in  solution  by  its  own 
pressure.  "Heavy"  wines  are  those  whose  alcoholic  strength  is  greater 
than  12  per  cent,  usually  14  to  25  per  cent.  They  are  the  products  of 
warm  climates,  and  include  the  sherries  of  the  south  of  Spain,  the 
ports  of  Portugal,  the  Marsalas  of  the  south  of  Italy,  the  Madeiras^ 
and  the  wines  of  southern  California.  The  adulteration  of  real  wine  is 
practically  limited  to  the  addition  of  coloring  matters,  and  to  "forti- 
fication" by  the  addition  of  alcohol  or  brandy.  Liquids  are  also 
manufactured  to  imitate  wines,  which  contain  no  grape-juice. 

Cider  is  the  fermented  juice  of  the  apple,  and  contains  from  3.5 
to  7.5  per  cent  of  alcohol. 

Spirits  are  prepared  by  fermentation  and  distillation.  They  differ 
from  beers  and  wines  in  containing  a  larger  percentage  of  alcohol,  35  to 
50  per  cent,  and  in  not  containing  any  of  the  non- volatile  constituents 
of  the  grains  or  fruits  from  which  they  are  prepared.  They  are  yellow 
in  color  when  stored  in  white  oak  casks  the  interior  of  which  has  been 
burnt,  and  colorless  or  faintly  yellow  when  kept  in  unburnt  casks. 
Besides  alcohol  and  water  they  contain  acetic,  butyric,  valerianic  and 
cenanthic  esters,  to  which  they  owe  their  flavor.  They  include :  brandy, 
sp.  gr.  0.929-0.934,  made  by  distilling  wine;  rum,  sp.  gr.  0.914-0.926, 
made  by  distilling  molasses;  and  whiskies  and  gins,  made  by  ferment- 
ing and  distilling  grains,  wheat,  rye,  barley  or  maize.  The  peculiar 
flavor  of  Scotch  and  Irish  whiskies  is  derived  from  the  smoke  of  a  peat 
Are;  that  of  gin  is  produced  by  distilling  from  juniper  berries. 
In  making  "straight"  whisky  the  distillate  is  not  completely  defusel- 
ated  (p.  292),  and  by  slow  oxidation  the  remaining  fusel  produces  the 
esters  to  which  the  spirit  owes  its  flavor.  Hence  when  newly  made  it 
i»  neither  palatable  nor  wholesome,  but  in  about  three  years  in  wood 
the  fusel  has  been  in  great  part  removed  by  oxidation,  the  whisky  is 
"ripe,"  and  continues  to  improve  with  age.  In  making  "blend" 
whisky  the  distillate  is  completely  defuselated  to  "neutral  spirit,"  and 
the  product  is  made  to  imitate  aged  whisky  more  or  less  closely  by 
addition  of  esters,  "beading  oil"  and  other  chemicals. 

Propyl  Hydroxid— Ethyl  carbinol — Primary  propyl  alcohol — 
CH3.CH2.CH2OH — 60 — is  produced,  along  with  ethylic  alcohol,  dur- 
ing: fermentation,  and  obtained  by  fractional  distillation  of  marc 
brandy,  from  cognacyil,  huile  de  nmrc  (not  to  be  confounded  with  oil 
of  wine),  an  oily  matter,  possessing  the  flavor  of  inferior  brandy, 
which  separates  from  marc  brandy,  distilled  at  high  temperatures; 


202 


MANUAL    OF    CHEMISTRY 


n 
4 


and  from  the  residaes  of  manufacture  of  alcohol  from  beet -root, 
grain,  molasses,  etc.  It  h  a  colorless  liquid,  has  a  hot  alcoholic 
taste,  and  a  fi'uity  odor;  boils  at  96, 7"^  (206.1'^FJ;  and  is  miscible 
with  water.  It  has  not  been  put  to  any  use  in  the  arts.  Its  iDtoxi- 
eating  and  poisonous  actions  are  ^eater  than  those  of  ethyl  alcohol - 
It  exists  iu  small  quantity  in  cider. 

Butyl  Alcohols—CjHiiOH— 74.— The  four  butyl  alcohols  theoi^eti- 
cally  possible  are  known  to  exist : 

Propyl  Carbinol — Primary  normal  butyl  alcohol — Buiyi  alcohol 
offermenta(hH^CR'd.Clh.C}h^CTi^OU-—is  formed  in  small  quan- 
tities during  alcoholic  fermentation,  and  may  be  obtained  by  repeated 
fractional  distillation  from  the  oily  liquid  left  in  the  rectification  of 
vinic  alcohol.  It  is  a  colorless  liquid;  boils  at  116, 8*^  (245.8°  FJ, 
It  is  more  actively  poisonous  than  ethyl  or  methyl  alcohol. 

Isopropyl  Carbinol  — Isobutyl  alcohol— ^Ha/CH.CH^OH  —  oc- 
curs in  the  fusel  oil  obtained  in  the  products  of  fermentation  and 
distillation  of  beet -root  molasses.  It  is  a  colorless  liquid,  sp.  gr. 
0,8U32;   boils  at  108.4°  (219.1°  F.). 

Ethyl-methyl  Carbinol  —  Secondary  butyl  alcohol  —  Butplene 
%firaie— *^^^"gH;)>CHOH— a  liquid  which  boils  at  99°  (210.2°  F.). 

Trimcthyl  Carbinol— Tertiary  butyl  alcohol,  CHj— COH— a  crystal- 

line  solid  which  fuses  at  25"^  (77^  FJ,  and  boils  at  82°  (179.6°  F.). 

Amylic  Alcohols — CsHixOH — 88.-=-The  eight  amyl  alcohols  theo- 
retically possible  {see  p.  285)  are  known.  The  substance  usually 
known  as  amylic  alcohol,  potato  spirit,  fusel  oil,  alcohol  amylicuni 
{BrJ,  is   the  primary  alcohol,  qj|^/ CH.  CH2.  CllaOlI,  with  lesser 

quantities  of  other  alcohols,  differing  in  nature  and  amount  with  the 
grain  used,  and  the  conditions  of  the  fermentation  and  distillation, 
each  kind  of  "spirit "  furnishing  and  containing  a  peculiar  fuseL 

In  the  process  of  manufacture  of  ardent  spirits  the  fusel  oil  aecu-' 
mulates  in  great  part  in  the  still,  but  much  of  it  distils  over,  and  is 
more  or  less  completely  removed  from  the  product  by  the  proeess  of  ^J 
defuselation*  ^M 

Bpirits  properly  freed  of  fusel  oil  give  off  no  irritating  or  foul  ^' 
fumes  when  hot.     They  are  not  colored  red  when  mixed  with  three 
parts  CsHflO  and  one  part  strong  H2SO4.     They  are  not  colored  red 
or  black  by  ammoniacal  silver  nitrate  solution.     When  150  parts  o€ 
the  spirit,  mixed  with  1  part  potash,  dissolved  in  a  little  H2O,  are* 
evaporated  down  to  15  parts,  and  mixed  with  an  equal  volume  oC 
dihite  H2SO4,  no  offensive  odor  should  be  gfiven  off.  ^m 

While  young  spirits  owe  their  i-ough  taste,  and,  in  great  measure  J9' 
their  intoxicating  qualities  to  the  presence  of  fusel  oil,  it  is  a  populaC 


4 


^j_ 


ALCOHOLS  —  HYDROCARBON    HYDROXIDS 


293 


Amyl  alcohol- c{i;;)CH.CH2,Cn.0H— is  the 


error  that  a  whiBky  would  be  improved  by  enmplete  removal  of  all 
products  except  ethyl  alcohol.  Tlie  improveiiieot  of  a  spirit  by  age 
is  due  to  chemical  changes  in  the  small  amount  of  fusel  n4ained  in  a 
properly  manufactured  product,  and,  were  this  absent,  the  spirit 
would  deteriorate  rather  than  improve  by  age. 

The  individual  ainylie  alcohols  have  the  following  characters  : 
Butyl  carbinol;  normal  amylic  alcohol,— CH:,.CH2.CH2.CHj.CHt;On 
— is  a  colorless  licjuid,  boils  at  137°  (278,6^  FJ.  Obtained  from 
normal  butyl  alcohol,  or  from  normal  amylamin.  It  yields  normal 
valerianic  acid  on  oxidation 

Isobutyl  Carbinol 

principal  constituent  of  the  fusel  oil  from  ^rain  and  potatoes.  It 
is  obt^iined  from  the  last  Tuilky  products  of  rectification  of  ak-oholic 
liquids.  Tbcse  are  shaken  with  lijO  to  remove  ethyl  alcohol,  the 
supernat^int  oily  fluid  is  decanted,  dried  by  contact  with  fused  calcium 
chlorid.  and  distilled;  that  portion  which  passes  over  between  128° 
and  132°  (262.4"-2G0.6'' F.)  beinj?  collected. 

It  is  a  colorless,  oily  liquid,  has  an  acrid  taste  and  a  peculiar  odor, 
first  not  unpleasant,  afterward  nauseating  arul  provocative  of 
ere  headache.  It  boils  at  131.4'^  (2:]G.5'"' F.),and  crystallizes  at 
—20°  (4°  PJ;  sp.  ^r.  0.8184  at  15°  (5°  F.).  It  mixes  with  alcohol 
and  ether,  but  not  with  water.  It  burns  with  a  pale  blue  flame  when 
.•ttfRciently  heated. 

When  exposed  to  air  it  oxidizes  very  slowly;  quite  rapidly,  how- 
ever, in  f'ontai^t  with  platinum* black,  forming  iso valerianic  acid.     The 
^tmi*  acid,  along:  with  other  substances^  is  produced  by  the  action  of 
the  more  powerful  f»xidants  npfui  atnyl  ah'ob<jL     Chlorin   attacks  it 
vTierfiretieaily,  forming  amyl  chli>rid,   IICl,  and  other  chlorinated  de- 
rivatives.    Sulfuric  acid  dissolves  in  amyl  alcohol,  with  formation  of 
limyURiilfiirir  a<nd,  SO^Ct'rJlii)!!,  corresponding  to  ethyl -sulfuric  acid 
(|».359).    It  also  forms  similar  acids  with  phosphoric,  oxalic,  citric,  and 
*«rtarie  acids.     Its  esters,  when  dissolved  in  ethyl  alcohol,  have  the 
^sff  ntid  odor  of  various  fruits,  and  are  used   in   the   preparation  of 
*ftilic!Hl  fruit -essences.     Amyl  ah^ohol   is  also  used  in  analysis  as  a 
***lvent,  particularly  fi»r  certain   alkaloids,  and  in   pharmacy  for  the 
8*'tillciHl  production  of  valerianic  acid  and  the  valerianates. 

Diethyl  Carbinol  — ^^3^h!/*^H^^"1^  produced  by  the  action 
^'  H  mixture  of  zinc  and  ethyl  iodid  on  ethyl  formate,  with  the 
*olM*M]ueiit  addition  of  H2O.  It  is  a  liquid  which  boils  at  115.5^ 
(24ir  FJ. 

Methyl-propyl  Carbinol— cHs—CHa—CH^/CHOH— a  liquid,  boil- 

'^^^?«l  II?*. 5"^  (245,3°  F,),  obtained  by  the  hydro|?enation  of  methyl- 
Pix^pylic  acetone. 


294  MANUAL    OF    CnEMISTRY 

OFT  \ 

Methyl-isopropyl  Carbinol —  /(.jj^v  _.Qg  ^CHOH — obtained  by  the 

hydrogenation  of  methyl -isopropylic  acetone;  or  by  the  action  of  hy- 
driodic  acid  upon  amylene,  and  the  action  of  moist  silver  oxid  upon 
the  product  so  obtained.  It  is  a  colorless  liquid,  sp.  gr.  0.829  at  0^ 
(32''  F.) ,  having  a  pungent,  ethereal  odor;  boils  at  112.5°  (234.5°  P.) , 
soluble  in  H2O  and  in  alcohol. 

Ethyl-dimethyl  Carbinol — Tertiary  amy  lie  alcohol —Amylene  hy- 
CHaX 
t^ra^e— CH3  — CH2-COH— is  a  liquid  which  solidifies  at  —12°  (10.4° 

CHs/ 
P.)  and  boils  at  102.5°  (216.5°  P.);   formed  by  the  action  of  zinc 
methyl  upon  propionyl  chlorid,  or  by  decomposition  of  tertiary  sulf- 
amylic  acid  by  boiling  H2O.     The  nitrite  of  this  alcohol  has  been  used 
as  a  substitute  for  amyl  nitrite. 

Cctyl  Hydroxid—06/y Zic  alcohol— Ethal—GwRs^OR— 2^2— is  oh- 
tained  by  the  saponification  of  spermaceti  (its  palmitic  ester).  It  is 
a  white,  crystalline  solid;  fusible  at  49°  (120.2°  F.)  ;  insoluble  in 
H2O;  soluble  in  alcohol  and  ether;  tasteless  and  odorless. 

Ceryl  Hydroxid— C27H55OH— 396— and  Miricyl  Hydroxid— CaoHei- 
OH — 438— are  obtained  as  white  crystalline  solids;  the  former  from 
China  wax;  the  latter  from  beeswax,  by  sponification. 


DIATOMIC,    OR    DIHTDRIC    ALCOHOLS;    GLYCOLS. 

The  paraffin  glycols  are  derived  from  the  paraffins  by  the  substi- 
tution of  two  hydroxy  Is  for  two  H  atoms.  They  bear  the  same  rela- 
tion to  the  monoatomic  alcohols  that  the  diacid  bases  bear  to  the 
inonacid  bases.  They  are  diprimary,  disecondary,  primary-secondary, 
etc.,  according  as  they  contain  groups  CH2OH  ;  CHOH,  or  COH. 
Their  "  Geneva "  names  are  derived  from  those  of  the  parent  hydro- 
carbons by  the  substitution  of  the  syllable  ^^diol"  for  the  terminal  e; 
and  they  are  distinguished  as  «,  P,  y,  8,  etc.,  according  as  the  hy- 
droxyls  occupy  1:2,1:3,1:4,1:5,  etc.,  positions.  Thus  the  primary- 
secondary  glycol  CH2OH.CH2.CHOH.CH3,  is  iS-butandiol  (p.  340). 

As  the  monohydric  alcohols  are  regarded  as  the  hydroxids  of  the 
univalent  alkyls  (p.  284),  so  the  dihydric  alcohols  are  considered  as 
the  hydroxids  of  bivalent  hydrocarbon  radicals:  (C2H4)'^  (OH)?, 
which  are  called  alkylens. 

They  may  be  obtained  from  the  neutral  haloid  esters  by  heating 
with  silver  acetate:  C2H4l2+2AgC2H302=2AgI  +  C2H4  (C2H302)2,  and 
saponification  of  the  ester  so  formed  by  caustic  potash:  C2H4  (C2H3- 
02)2+2KHO=C2H4  (OH)2+2KC2H302  (see  p.  363). 

While  the  monoatomic  alcohols  are  only  capable  of  forming  a  sin- 
gle ester  with  a  monobasic  acid,  the  glycols  are  capable  of  forming 
two  such  esters:  CH2OH,  CH2(C2H302)'  and  C2H4:  (C2H302)'2. 


ALCOHOLS  — HYDBOCARBON    HYDBOXIDS  295 

Methene  Glycol,  which  would  have  the  eomposition  H2C<^oHi  ^^ 
not  known  (p.  269).  Its  haloid  esters  are,  however,  known,  A  con- 
densation product  corresponding  to  it  exists  as  methene  dimethylate, 
^s^XOCHs*  ^^  called  methylal  and  formal,  as  a  thin  liquid,  boiling 
at  42  (107.6°  P.),  soluble  in  alcohol,  ether,  and  water,  sp.  gr.  0.855; 
formed  by  oxidizing  methyl  alcohol  with  H2SO4  and  Mn02.  It  has 
been  used  as  a  medicine. 

Ethene  Glycol — Ethylene  glycol,  or  alcohol,  or  hydroxid— 
CHsOH 

I         — 62. — This,  the  best  known  of  the  glycols,  is  prepared  by  the 
CH2OH 

action  of  dry  silver  acetate  upon  ethylene  bromid.  The  ester  so  ob- 
tained is  purified  by  redistillation,  and  decomposed  by  heating  for 
some  time  with  bai-ium  hydroxid. 

It  is  a  colorless,  slightly  viscous  liquid;  odorless;  faintly  sweet; 
«p.  gr.  1.125  at  0°  (32°  F.) ;  boils  at  197°  (386.6°  P.) ;  sparingly  sol- 
uble in  ether;  very  soluble  in  water  and  in  alcohol. 

It  is  not  oxidized  by  simple  exposure  to  air,  but  on  contact  with 

platinum -black  it  is  oxidized  to  glycolic  acid;  more  energetic  oxidants 

transform  it  into  oxalic  acid.     Chlorin  acts  slowly  upon  glycol  in  the 

cold;  more  rapidly  under  the  influence  of  heat,  producing  chlorinated 

and  other  derivatives.     By  the  action  of  dry  HCl  upon  cooled  glycol, 

a  product  is  formed,  intermediate  between  it  and  ethylene  chlorid,  a 

CH2OH 

neutral  compound — ethene  chlorhydrin,    I         ,  which  boils  at  130° 

CHfCl 

<266°P.). 

TBIATOMIC,   OB    TBIHYDBIC    ALCOHOLS;    GLYCEBOL8. 

These  are  derived  from  the  paraffins  by  the  substitution  of  three 
hydroxyls  for  three  hydrogen  atoms,  linked  to  different  carbon  atoms. 
The  simplest  triprimary  glycerol,  which  would  have  the  formula: 
CH(CH20H)3,  is  unknown.  The  simplest  known  representative  of 
the  class  is  the  ordinary  glycerine,  more  properly  called  glycerol* 
which  is  diprimary-secondary.  The  relations  of  the  monoatomic,  di- 
atomic, and  triatomic  alcohols  to  each  other  and  to  the  parent  hydro- 
carbon are  shown  in  the  following  formulae: 

CH3  CH3  CH2OH  CHaOH 

CH2  CHa  CHa  CHOH 

I  I  -  I  I 

CH3  CHaOH  CH2OH  CHaOH 

Propane,  Propyl  aleohol.  Propyl  glycol.  Olyeerol. 

The  Geneva  names  of  the  glycerols  are  derived  from  those  of  the 
hydrocarbons  by  the  substitution  of  the  syllable  ^Hriol"  for  the  ter- 
minal e.     Thus  glycerol  is  propantrioL 


296 


MANUAL.    OF    CHEMISTKY 


They  are  obtained  by  the  saponification  of  their  esters,  either 
those  existing  in  natnre  or  those  produced  artificially. 

They  combine  with  acids  to  form  three  series  of  esters,  known 
generically  as  raonoglyccrids,  diglycerids,  and  triglycerids,  formed 
by  the  combination  of  one  molecule  of  the  alcohol  with  one,  two»  or 
three  molecnles  of  a  monobasic  acid.  The  names  of  the  individual 
esters  terminate  in  in,  and  have  a  prefix  indicating  the  number  of 
aeid  residues.  Tbus:CjH5(0H)2.C2HiO2  is  monacetinj  GlislOH) 
(02H302)2  is  diacetin,  and  CaHs  (CsHaOzh  is  triacetin  (p.  364). 

Glycerol — Glycerin— Propenyl  alcohol  —  Glycerinum  (U.  S.) — 
CaHsCOHla— 92™-was  first  obtained  as  a  secondary  product  in  the 
manufacture  of  lead  plaster;  it  is  now  produced  as  a  by-product  in 
the  manufacture  of  soaps  and  of  steai-iu  caudles.  It  exists  free  in 
palm-oil  and  in  other  vegetable  oils.  It  is  produced  in  small  quan- 
tity during  alcoholic  fermentation^  and  is  consequently  present  in 
wine  and  beer.  It  is  much  moi-e  widely  disseminated  in  its  esters, 
the  neutral  fats,  in  the  animal  and  vegetable  kingdoms. 

It  has  been  obtained  by  partial  synthesis,  by  heating  a  mixture  of 
allyl  tribromid,  silver  acetate  and  acetic  acid,  and  saponifying  the 
triacettu  so  obtained.  Also  by  total  synthesis,  by  reduction  of  dioxy- 
acetone  (p,  310}  by  sodium  amalgam  iu  presence  of  aluminium  sul- 
fater    CH20H.CO.CH20H  +  H2=CH20H.CHOH.CH20H. 

Glycerol  obtained  by  saponification  of  fats,  and  purified  by  dis- 
tillation iu  a  current  of  superheated  steam,  known  as  "distilled  tjly- 
eerin,"  is  reasonably  pure.  The  only  impurities  likely  to  be  present 
are  water,  and  sometimes  arsenic. 

Glycerol  is  a  colorless,  odorless,  syrupy  liquid,  has  a  sweetish 
taste;  sp.  gr.  1.26  at  15"^  (59"^  P.),  Although  it  cannot  usually  be 
caused  to  crystallize  by  the  application  of  the  most  intense  cold,  it 
does  so  sometimes  under  imperfectly  understood  conditions,  forming- 
small,  white  needles  of  sp.  gr.  1.268,  and  fusible  between  17°  and  18** 
{62.6^  and  64.6"^  P.).  It  is  soluble  in  all  proportions  in  water  and 
alcohol,  insoluble  in  ether  and  in  chloroform.  It  is  a  good  solvent 
for  a  number  of  mineral  and  organic  substances  (glycerites  and  gly- 
eeroles) .  It  is  not  volatile  at  ordinary  temperatures.  When  impure 
glycerol  is  heated,  a  portion  distils  unaltered  at  275^-280'^  (527*^- 
536°  F.),  but  the  greater  part  is  decomposed  into  aemlein,  acetic  acid» 
carbon  dioxid,  and  combustible  gases.  It  may  be  distilled  unchanged 
in  a  current  of  superheated  steam  between  285°  and  315°  ( 545^^-599*^ 
F.).  Pure  glycerol  distils  unchanged  at  290°  at  a  pressure  of  75G 
mm.»  and  at  180°  at  20  mm. 

Concentrated  glycerol,  when  heated  to  150°  (302°  F.)  ignites  and 
burns  without  odor  and  without  leaving  a  residue,  and  with  a  pale 
blue  flame*     It  may  also  be  burnt  from  a  short  wick. 


^ 


ALCOHOLS  — HYDHOCARBON    HYDROXIDS 


297 


Glycerol  is  readily  oxidized,  yielding  diffei-eot  produtits  with  differ- 
ijBnt  degrees  of  oxidation.  Platinum -black  oxidizes  it,  with  formation  ^ 
tnally,  of  H2O  and  COj.  Oxidized  by  manganese  dioxid  and  H2SO4, 
it  yields  CO2  and  formic  acid.  If  a  layer  of  glycerol  dibited  with  an 
equal  volume  of  H2O  be  floated  on  the  surface  of  HNO3  of  sp,  gr.  1,5, 
a  mixture  of  several  acids  is  formed:  oxalic,  C204H^;  glyceric,  C3Hfi04, 
formic,  CH2O2;  glycollie,  C^H^Oa;  gIyoxylic»  CjHiO^;  and  tartaric. 
CiHeO(t.  When  glycerol  is  heated  with  potassium  hydroxid,  a  mix* 
tare  of  potassium  acetate  and  formate  is  produced.  When  glycerol, 
diluted  with  20  volnraes  of  H2O,  is  heated  with  Br;  CO^t  bromoform^ 
glyceric  acid,  and  HBr  are  produced.  Phosphoric  anhydrid  removes 
the  elements  of  H2O  from  glycerol,  with  formation  of  acrolein 
(p.  427).  A  similar  action  is  effected  by  heating  with  H2SO4,  or  with 
monopotassic  sulfate.  Heated  with  oxalic  acid,  glycerol  yields  CO2 
and  formic  acid. 

The  presence  of  glycerol  in  a  liquid  may  be  detected  as  follows: 
Add  NaHO  to  feebly  alkaline  reaction,  and  dip  into  it  a  loop  of  Pt 
wire  holding  a  borax  bead;  then  heat  the  bead  in  the  blow -pipe  flame, 
which  is  colored  green  if  the  liquid  contain  riu  of  glycerol. 

The  glycerol  used  for  medicinal  purposes  should  respond  to  the 
following  tests:    (1)  its  sp.  gr*  should  not  vary  much  from  that  given 

^ above;  (2)  it  should  not  rotate  polarized  light;  (3)  it  should  not  turn 
brown  when  heated  with  sodium  nitrate;  (4)  It  should  not  be  colored 
by  H*S;  (5)  when  dissolved  in  its  own  weight  of  alcohol,  containing 
one  per  cent,  of  H-SOj,  the  solution  should  be  clear;  (6)  when  mixed 
w^ith  an  equal  volume  H2804»  of  sp.  gr.  1.83,  it  should  form  a  limpid, 
brownish  mixture,  but  should  not  give  off  gas. 


POLYATOMIC,  OR  POLYHYDBIC  ALCOHOLS. 


Tctratomic  Alcohols  contain  four  hydroxyls.  The  best  known  is: 
E  ry  t h  ro  1  —  Eryihrite  —  Phycite  —  Erijfhroglun'n  —  CH2OH.- 
(CUOH)2.CH201I  — which  is  a  product  of  decomposition  of  erythrin, 
C^oHaOm,  which  exists  in  the  lichens  of  the  genus  rocella.  It  erystal- 
lir#»s  in  large,  brilliant  prisms;  very  soluble  in  H2O  and  in  hot  alco- 
hol, almost  insoluble  in  ether;  sweetish  in  taste;  its  solutions  neither 
affect  polarized  light,  nor  reduce  Fehliug's  solution »  nor  are  capable 
of  fermentation.  Its  watery  solution,  like  that  of  sugar,  is  capable 
of  diBdolving  a  considerable  quantity  of  lime,  and  from  this  solution 
alcohol  precipitates  a  definite  compound  of  erythrite  and  calcium. 
By  oxidation  with  platinum*black  it  yields  erytbroglucic  acid,  CiH^Os. 
With  fuming  HNOa  it  forms  a  tetranitro  compound,  which  explodes 
under  the  hammer. 

Pentatomic,   or   Pcntahydric  Alcohols — Pentites — contain  flv# 


298  MANUAL    OF    CHEMISTRY 

hydroxyls.  The  only  member  of  the  group  known  to  exist  in  nature 
is  the  simplest  C5H7(OH)6,  called  adonite,  obtained  from  Adonis 
vemalis.  Other  members  of  the  series  are  obtained  by  reduction  of 
the  corresponding  aldopentoses  (p.  310). 

Hexatomic,  or  Hexahydric  Alcohols — Hexites — contain  six  hy- 
droxyls. They  are  closely  related  to  the  sugars  (p.  311),  which  they 
resemble  in  their  properties,  although  they  do  not  reduce  Fehling's 
solution,  and  are  not  fermented  by  yeast.  They  are  obtained  by  re- 
duction of  the  corresponding  glucoses,  aldohexoses  and  ketohexoses 
(p.  314).     Three   hexites  occur   in  nature: 

Mannitol  —  Jfanm^e— CH2OH.  (CHOH) 4. CH2OH— constitutes  the 
greater  part  of  manna,  and  also  exists  in  a  number  of  other  plants. 
It  is  also  produced  during  the  so-called  mucic  fermentation  of  sugar, 
and  during  lactic  fermentation.  It  crystallizes  in  long  prisms,  odor- 
less, sweet;  fuses  at  166°  (330.8°  F.)  and  crystallizes  on  cooling; 
boils  at  200°  (396°  P.),  at  which  temperature  it  is  converted  into 
mannitan,  C6H12O6;  soluble  in  H2O,  very  sparingly  in  alcohol. 
When  oxidized  it  yields  first  mannonic,  then  mannosaccharic  acid 
(p.  346),  and  finally,  oxalic  acid.  Organic  acids  combine  with  it  to 
form  esters. 

Sorbitol — Sorbite  —  occurs  in  mountain -ash  berries.  It  forms 
crystals,  soluble  in  water. 

Dulcitol  —  Dulcite — MelampyrUe  —  Dulcose  —  Dulcin  —  exists  in 
melampyrum  nemorosutn.  It  forms  colorless,  transparent  prisms, 
fuses  at  182°  (359.6°  F.),  is  odorless,  faintly  sweet,  neutral  in  reac- 
tion,, and  optically  inactive.  It  is  subject  to  decompositions  very 
similar  to  those  to  which  mannite  is  subject,  yielding  dulcitan, 
CeHi'iOs. 

Heptatomic,  Octatomic  and  Nonatomic  Alcohols,  containing 
respectively  seven,  eight  and  nine  hydroxyls,  are  also  known. 

All  polyatomic  alcohols  in  solutions  alkalized  with  caustic  soda, 
when  agitated  with  benzoyl  chlorid,  form  insoluble  benzoic  esters, 
and,  under  proper  conditions,  the  separation  is  quantitative,  a  fact 
which  is  utilized  for  their  separation.  The  diamins  (p.  385)  behave 
similarly  with  benzoyl  chlorid. 

ALDEHYDES    AND    KETONES. 

The  pure  aldehydes  and  ketones,  containing  only  CHO  or  CO  and 
hydrocarbon  groups,  are  to  be  considered  rather  as  the  second  prod- 
ucts of  oxidation  of  the  paraffins  than  as  the  first  products  of  oxi- 
dation of  the  alcohols,  primary  or  secondary.  WTiile  the  distinction 
is  not  material  with  the  aldehydes  derivable  from  the  monoatomic 
alcohols,  it  is  so  with  similar  derivatives  of  alcohols  of  higher  atom- 


ALDEHYDES   AND    KETONES  299 

icity  and  with  the  ketones,  which  raa}^  be  either  pure  aldehydes  or 
ketones,  or,  if  they  retain  alcoholic  groups,  substances  of  mixed 
function :  aldehyde -alcohols  and  ketone -alcohols.  Thus  from  the 
hydrocarbons  the  following  may  be  derived: 

2(CH3.CH3)+02=2(CHs.CH20H)  =        Alcohols— C„  Hjn  +  2O, 

CH3.CH3-h02=H20-hCH3.CHO  =        Aldehydes— Cn  HjuO, 

CHi.CH3-h202=2H20  -f-CHO.CHO  =        Glyoxals-Cn  H2n-202, 

CH3.CH2.CH3-f  02=HaO-f-CH3.CO.CH3  =        Ketones— C„  Hjn  O, 

and  from  the  alcohols  not  only  the  above,  but  also  substances  such  as 

2(CHaOH.CH,OH)+02=2H20-h2( CHO.CH2OH )=Glycolyl  aldehyde, 
2(CH20H.CHOH.CHaOH)-f02=2H20-h2(CHO.CHOH.CH20H)=Glycerol  aldehyde, 
2(CHaOH.CHOH.CH20H)-h02=2H20-h2(CH20H.CO.CH20H)  =Glycerol  ketone. 

The  aldehydes  and  ketones  are  isomeric  with  each  other  and  also 
with  the  allyl  alcohols,  CH2:CH.CH20H,  and  the  methylene  oxids, 
(CH2),:0. 

Both  aldehydes  and  ketones  contain  the  carbonyl  group  CO,  which 
in  the  ketone  is  united  to  two  alkyls,  CH3.CO.CH3;  and  in  the  alde- 
hyde to  one  alkyl  and  a  hydrojjou  atom,  CH3.CO.H. 

Because  of  the  presence  of  this  oxygen  atom,  doubly  linked  to 
carbon,  both  aldehydes  and  ketones  form  addition  products  with 
hydrogen,  the  former  to  produce  primary,  and  the  latter  secondary 
alcohols:  CH3.CHO+H2=CH3.CH20H,  audCH3.CO.CH3+H2=CH3.- 
CHOH.CH3.  Tin-  aldehydes,  in  which  the  C:0:  is  in  a  terminal 
^roup,  also  form  other  addition  products  mentioned  below. 

Aldehydes  and  ketones  are  acted  upon  by  phosphorus  pentaehlorid 
to  form  compounds  iu  which  oxygen  is  replaced  by  the  halogen.  Thus 
acetic  aldehyde  yields  ethidene  chlorid,  or  dichlorethane :  CH3.CHO 
-f-PCl5=CH3.CHCl2  +  POCl3;  and  acetone  yields  P  dichlorpropane : 
CH3.CO.CH3+PCl5=CH3.CCl2.CH3+POCl3. 

All  aldehydes  and  ketones  condense  with  hydroxylamin  to  form 
oxims  (p.  409):  CH3.CHO  +  NH2.0H=CH3.CH:N.OH  +  H20,  and 
with  phenylhydrazin  to  form  hydrazones  and  osazones  (p.  485).  Both 
of  these  reactions  are  extensively  used  for  the  identification  of  sub- 
stances containing  the  C:0:  group. 

The  aldehydes  and  ketones  may  be  considered  as  derivatives  of 

formic  aldehyde,  O  :  C^jj,  alkyls  being  substituted  for  one  H  atom  only 
in  the  aldehydes:  0:C<(h^',  and  for  both  in  the  ketones:  0:C<(cHa- 

ALDEHYDES. 

The  name  "aldehyde"  is  a  contraction  of  "alcohol  dehydrogeu- 
atnm/'  derived  from  the  method  of  formation  of  these  bodies  by 
removal  of  hydrogen  from  alcohol. 


300 


MANUAL    OP    CHEMISTRY 


The  aldehydes  are  formed:  (1)  By  the  limited  oxidation  of  the 
correspondmg\leoliols:  2CH3.CH20H+02^2CH3.CHO+2HnO;  (2) 
By  the  action  of  nascent  hydrogen  upon  the  corresponding  acidyl 
chlorids  (p.  352),  or  anhydrids  {p.  351):  CH3.C0.C1+H2^CH3.- 
CHO  +  nCl,  or  (CH3.CO)20+2H2--2CH3.CHO+H20;  (3)  By  the 
distillation  of  a  mixture  of  calcium  formate  and  the  Ca  salt  of  the 
(corresponding  aeid:  (H.COO)2Ca+(CH3.COO)2Ca— 2C03Ca+2CH3.- 

cno. 

The  aldehydes,  being  intermediate  between  the  alcohols  and  aeids^ 
are  readily  converted  into  the  former  by  the  action  of  re<inciog  agents: 
CH:i,Cn6  +  H2  =  CHn.CH20H;  or  into  the  latter  by  oxidation: 
20n3.CH0+O2  =  2CH3.C00H.  The  facility  with  which  the  alde- 
hydes are  oxidized  renders  them  active  reducing  agents. 

They  combine  with  the  monometallic  alkaline  sulfites  to  form  crys- 
talline com  pounds,  whose  formation  is  frequently  resorted  tn  for  their 
separation  and  purification:  CH3.CHO+SO3HNa^^CH3.CH(^30^jlj^^ 

They  unite  directly  with  ammonia  to  produce  crystal  I  im-  coni- 
pciunds  cMiled  aldehyde  ammonias  (p.    409):     CH3.CHO -h  NH3  =^ 

CHaCH 


HO 
\NM, 


Chlorin  and  brorain  displace  the  hydrogen  of  the  aldehydic  group 
with  formation  of  aeidyl  chlorids  or  bromids;  t'Ha.CHO  +  Cb^ 
CH:!  C0.C1+HCL  The  oxj^gen  of  the  same  group  may  also  be  dis* 
placed  by  chlorin^  by  the  action  of  phosphorus  pentachlorid*  with 
formation  of  paraffin  dichlorids;  CH3.CHOH-PCl5=^CH3.CHCl2+ 
POCIa.  By  indirect  means  compounds  nmy  also  be  obtained  in  which 
the  hydrogen  of  the  hydrocarbon  group  is  substituted  by  chlorin,  as 
chloral  is  obtained  from  ethylic  alcohoh  CH3,CH20H+'4Cl2=CCl3.- 
CHO+5HCL 

The  aldehydes  polymerize  readily,  forming  cyclic  compounds,  as  tri- 
oxymethylene  is  formed  by  formic  aldehyde  r  3H,CH0— O^cHslo/CHj* 
Or  two  aldehyde  molecules  may  condense,  by  union  through  carbon 
atoms,  to  form  oxyaldehydes  (p.  308),  as  aldol  is  formed  by  conden- 
sation of  acetic  aldehyde:  2CH3.CHO=CHa.CHOH.CH2.CHO. 

Hydrocyanic  acid  combines  with  the  aldehydes  (and  ketones)  to 
produce  oxycyanids,  or  nitriis  of  the  oxyacids:  CH3.CH0+HCN= 
CHa.CHs^^^j^^  which,  in  turn,  are  decomposable  by  acids  or  alkalies 
with  formation  of  the  «-oxyacids  (p.  «^0)- 

Formaldehyde ^lbr»ij^^  hydrid — ^H.CHO — 30^8  formed  when 
air  charged  with  vapor  of  raethylic  alcohol  is  passed  o%^er  an  incan- 
descent platinum  wire.  It  is  also  produced  by  the  dry  distillation  of 
calcium  formate:  {H.COO)2Ca=CaC03+H.COH.  By  strong  cooling. 
it  condenses  to  a  colorless  liquid,  which  boils  at-^21'^  ( — 5.8°  F,).    It 


.h-^ 


ALDEHYDES    AND    KETONES 


901 


I 
I 

I 
I 


has  a  sharp,  penetrating  odor,  and  is  an  active  germicide.  It  is  exten- 
sively used  as  an  antiseptic  and  disinfectaut,  either  in  the  gaseons 
form  or  in  aqueous  solution.  The  commercial  formaline  is  a  40  per 
cent  solution* 

Formic  aldehyde  is  probably  produced  as  an  intermediate  product 
in  plant  nutrition,  when  carbon  dioxid  is  decomposed  by  the  green 
pigment,  chlorophyll*  under  the  influence  of  sunlight,  with  liberation 
of  oxygen:  CO2  +  H2O— H*CH0  +  02i  and  when  so  produced  it  may 
readily  polymerize  to  form  hexoses  (p.  311)  r  GH.CHO^CeHisOo. 

Formaldehyde  polymerizes  with  great  readiness  by  moderate  eleva- 
tion of  temperature  to  form  paraformaldehyde,  or  trioxy  in  ethylene, 

^\CH*!o/^^-'  ^'^ich  is  also  obtained  as  a  crystalline  substance, 
fusing  at  152""  (305.6''  F,),  insoluble  in  H^iO.  alcohol  and  ether,  by 
distilling  glycollie  acid  with  HgSOi,  or  by  the  action  of  silver  oxalate 
or  oxid  on  methene  iodid:  CH2I2+ Ag20=H.CHO  +  2AgI. 

Formic  aldehyde  reacts  with  a  great  variety  of  substances,  and,  in 
reactions  at  elevated  temperatures  may  advantageously  be  replaced  by 
the  solid  trioxymethylene,  which  is  then  dissociated.    Like  all  aide- 

hydes  (and  it  is  doubly  an  aldehyde  ^  0:C\^j|j,  it  is  an  active  reduc- 
ing agent.  With  caustic  alkalies  it  forms  methyl  alcohol  and  a  for- 
mate: 2HXHO  +  NaHO^H.OH20H+H,COONa,  or,  in  thepi-esence 
of  CuO,  a  formate  and  hydrogen:  H.CH0  +  NaH0=H,C00Na+H2- 
Calcium  hydroxid  and  other  basic  hydroxids,  by  prolonged  contact, 
cause  its  polymerization  to  formose  (p.  314):  6H.CHO=C<jHi20fl. 
With  ammonia  it  forms  hexamethylene  tetramin  (p.  409)  j  and  with 
ammoniacal  salts  it  forms  a  variety  of  complex  amins  and  nitrils 
(pp.  380,  393). 

An  extremely  valuable  property  of  formic  aldehyde  is  the  facility 
with  which  it  parts  with  it^  oxygen  atom,  by  reason  of  which  it 
readily  enters  into  condensations,  uniting  other  molecule-remainders 
throogh  the  bivalent  group  OH^. 

A  cotidensaiion  is  the  formation  of  a  new  moleaih  hy  the  union  of 
Ike  remainders  of  two  or  more  others ^  teith  the  splitting  off  of  water, 
alcohol,  or  some  other  snhsiance.  A  condensation  differs  from  a  poly- 
fHerizafioH  in  that  in  the  latter  nothing  is  split  off,  and  all  the  sub- 
atances  involved  are  polymeres  of  each  other.  Sometimes  condensa- 
ttons  are  effected  by  simple  contact  of  the  reacting  substances  at  more 
or  less  elevated  temperatures j  but,  more  usually,  the  presence  of  an- 
otfaer  substance,  acting  as  a  contact  agent,  is  required.  Substances 
acting  in  this  manner  are  quite  numerous,  and  are  called  condensing 
agents*  Probably  the  most  important  are  aluminium,  ferric  and  zinc 
eblorids,  hydrochloric  and  sulfuric  acids*  sodium  acetate  and  ethylate, 
pyrtdin,  and  piperidin. 


302  MANUAL    OF    CHEMISTRY 

As  examples  of  the  simplest  condensations  with  formic  aldehyde- 
we  may  mention  the  two  following:  With  alcohols  it  condenses  ta. 
produce  formals(p.  306):  2H.CH20H+H.CHO=CH3.0.CH2.0.CH8 
+H2O.  With  secondary  amins  (p.  377)  it  condenses  to  form  alkyl 
diamins  (p.  380):  2R'2NH+H.CHO=:R'2N.CH2.NR/2+H20;  an  ac- 
tion which  is  particularly  marked  with  aromatic  amins  (p.  470) : 
2C6H5.NH2+  H.  CHO=  CeHs.NH.  CH2.  NH.CeHs  +  H2O.  Other  in- 
stances of  the  condensing  action  of  formic  aldehyde  will  be  con- 
sidered later. 

The  presence  of  formic  aldehyde,  which  is  now  frequently  added  to 
milk  and  other  articles  of  food,  may  be  recognized  by  the  following 
reactions,  after  distillation,  if  necessary:  (1)  Heat  with  0.5  cc.  di- 
methylaniliu  and  a  few  drops  H2SO4  on  the  water-bath  for  half  an 
hour;  add  excess  of  alkali;  expel  excess  of  dimethylanilin  with  a  cur- 
rent of  steam;  filter;  place  the  filter  in  a  porcelain  capsule  and 
moisten  it  with  acetic  acid;  add  a  trace  of  lead  peroxid,  and  warm:  an 
intense  blue  color  (p.  503).  (2)  Add  the  liquid  (distillate)  to  an  equal 
volume  of  aqueous  solution  of  anilin  (3:1000):  a  white  ppt.  (3)  Dis- 
solve 0.01  morphin  hydrochlorid  in  1  cc.  concentrated  H2SO4,  and  mix 
two  drops  of  this  and  suspected  solutions:  an  intense  rose- violet  color. 

Acetaldehyde— Acetic  Aldehyde— .4 r^^^y/  hydrid—CRz.CHO—^Ar 
— is  formed  in  all  reactions  in  which  alcohol  is  deprived  of  H  without 
introduction  of  0.  It  is  prepared  by  distilling  from  a  capacious  retort, 
connected  with  a  well-cooled  condenser,  a  mixture  of  H2SO4,  6  pts.; 
H2O,  4  pts.;  alcohol,  4  pts.,  and  powdered  manganese  dioxid,  6  pts. 
The  product  is  redistilled  from  calcium  chlorid  below  50°  (122°  P.). 
The  second  distillate  is  mixed  with  two  volumes  of  ether,  cooled  by  a 
freezing  mixture,  and  saturated  with  dry  NH3;  there  separate  cr3's- 
tals  of  aldehyde  ammonia,  CHs.CHn^qh",  which  are  washed  with 
ether,  dried  and  decomposed  in  a  distilling  apparatus,  over  the  water- 
l^Mtli,  with  tlie  i)n)per  quantity  of  dilute  H2SO4;  tlie  distillate  is  finally 
dried  over  ealeiinn  clilorid  and  rectified  below  35°  (95°  F.). 

Acetic  aldehyde  is  also  formed  by  heating  acetylene  with  vapor  of 
water:   CH:  CH+H20=CH3.CHO  (p.  288). 

Aldehyde  is  a  colorless,  mobile  liquid;  has  a  strong,  suffocating 
odor;  sp.  gr.  0.790  at  18°  (64.4°  F.) ;  boils  at  21°  (69.8°  F.) ;  soluble 
in  all  proportions  in  water,  alcohol  and  ether.  If  perfectly  pure,  it 
may  be  kept  unchanged;  but  if  an  excess  of  acid  have  been  used  in 
its  preparation,  it  gradually  decomposes.  When  heated  to  100°  (212*^ 
F.),  it  is  decomposed  into  water  and  crotonic  aldehyde. 

Ill  the  presence  of  nascent  H,  aldeh\de  takes  up  H2,  and  regen- 
erates alcohol.  CI  converts  it  into  avolyl  chlorid,  C2H3O.CI,  and 
f)ther  products.  Oxidizing  agents  convert  it  into  acetic  acid.  At 
the   ordinary  temperature  H2SO4;   HCl;   and    SO2  convert  it  into  a 


ALDEHYDES    AND    KETONES  C03 

colorless  liquid  called  paraldehyde  (C2H40)8,  which  boils  at  124° 
(255.2°  P.),  and  is  more  soluble  in  cold  than  in  warm  water.  The 
same  reagents,  acting  upon  aldehyde  at  temperatures  below  0°  (32°  P. ) 
convert  it  into  metaldehyde  ((32H40)«.  When  heated  with  potassium 
hydi'oxid,  aldehyde  becomes  brown,  a  brown  resin  separates,  and 
the  solution  contains  potassium  formate  and  acetate.  If  a  watery 
solution  of  aldehyde  be  treated,  first  with  NH3  and  then  with  H2S,  a 
solid,  crystalline  base,  thialdin,  C6H13NS2,  separates.  It  also  forms 
crj'stalline  compounds  with  the  alkaline  bisnlfites.  It  decomposes 
solutions  of  silver  nitrate,  separating  the  silver  in  the  metallic  form, 
and  under  conditions  which  cause  it  to  adhere  strongly  to  glass. 

Vapor  of  aldehyde,  when  inhaled  in  a  concentrated  form,  produces 
asphyxia,  even  in  comparatively  small  quantity.  When  diluted  with 
air  it  is  said  to  act  as  an  anaesthetic.  When  taken  internally  it 
causes  sudden  and  deep  intoxication,  and  it  is  to  its  presence  that  the 
iBrst  products  of  the  distillation  of  spirits  of  inferior  quality  owe  in  a 
great  measure  their  rapid,  deleterious  action. 

Trichloraldehyde  —Trichlor acetyl  hydrid — Chloral — CCI3.CHO  — 
147.5 — is  one  of  the  final  products  of  the  action  of  CI  upon  alcohol, 
and  is  obtained  by  passing  dry  CI  through  absolute  alcohol  to  satu- 
ration; applying  heat  toward  the  end  of  the  reaction,  which  requires 
several  hours  for  its  completion.  The  liquid  separates  into  two 
layers;  the  lower  is  removed  and  shaken  with  an  equal  volume  of 
concentrated  H2SO4  and  again  allowed  to  separate  into  two  layers; 
the  upper  is  decanted;  again  mixed  with  H2SO4,  from  which  it  is 
distilled;  the  distillate  is  treated  with  quicklime,  from  which  it  is 
a^ain  distilled,  that  portion  which  passes  over  between  94°  and  99° 
(20i.2°-210.2°  P.)  being  collected.  It  sometimes  happens  that 
chloral  in  contact  with  H2SO4  is  converted  into  a  modification,  in- 
soluble in  H2O,  known  as  metachloral;  when  this  occurs  it  is  washed 
with  H2O,  dried  uml  heated  to  180°  (356°  F.),  when  it  is  converted 
into  the  soluble  variety,  which  distils  over. 

The  formation  of  chloral  from  alcohol  does  not  progress  according 
to  the  simple  equation:  CH3.CH20H+4Cl2=CCl3.CHO+5HCl,  but 
passes  through  several  stages.  First,  fho  alcohol  is  oxidized  to  alde- 
hyde: CH3.CH20H+Cl2=CH3.CHO+2HCI.  This  reacts  with  alcc^liol 
to  produce  acetal  (p.  306)-  CH3.CHO+2CH3.CHoOH=CH3.CH  (OC2- 
H5)j+H20.  This  is  then  converted  into  trichloracctal:  CH3.CH- 
(OC2H5)2+3Cl2=CCl3.CH(OC2H5)2+3HCl.  This,  by  the  action  of 
the  hydrochloric  acid  formed  in  the  last  reaction,  yields  chloral  alco- 

holateand  ethyl  chlorid:  CCl3.CH(OC2H5)2+HCl=CCl3.CH<(o^2H5 
-f-CsHsCl.  And  from  the  former  chloral  is  liberated  by  sulfuric  acid: 
CCl3.CH<^OX:2H6+H2S04=CCl3.CHO  +  (C2H5)HS04+H20. 


MANUAL    OF    CHEMISTKY 

Chloral  is  a  eolorless  liquid^  unctuous  to  the  touch;  has  a  pene- 
tratiog  odor  and  an  acrid,  caustic  taste;  sp.  gr.  1.502  at  18°  (64.4" 
FJ;  boils  at  97''  (206,6''  FJ»  very  soluble  iu  water,  alcohol,  and 
ether  ;  dissolves  CI,  Br,  I,  S,  and  P*  Its  vapor  is  highly  iiritatiog. 
It  distils  without  alteration. 

Although  chloral  has  not  been  obtained  by  the  direct  substitution 
of  CI  for  H  in  aldehyde,  its  reactions  show  it  to  be  au  aldehyde.  It 
forms  erystalliue  compounds  with  the  bisulfttes;  it  reduces  solutions 
of  silver  nitrate  in  the  presence  of  NHa;  NHa  and  H2S  form  with  it  a 
compound  similar  to  thiakliu;  with  nascent  H  it  regenerates  alde- 
hyde; oxidizing  agents  convert  it  into  trichloracetic  acid.  Alkaline 
solutions  decompose  it  with  formation  of  chloroform  and  a  formate. 

With  a  small  quantity  of  H^O  chloral  forms  a  solid,  crystalline 
hydra te»  heat  being  at  the  same  time  liberated.  This  hydrate  has  the 
composition  C^jIICbO.HaO*  and  its  constitution,  as  well  as  that  of 
chloral  itself,  is  indicated  by  the  formula* : 


CHi 

I 

CHO 
Ald<.'byde. 


CCI3 
I 
CHO 

Trtchlorald«*h3rd« 


CCl, 
I 

CH(0H)2 

Cblnrm)  hydrftto. 


I 


Chloral  Hydrate^— Chloral  (U.S.) — is  a  white,  crystalline  solid; 
fuses  at  57''  (134.6°  P.)^  boils  at  m°  (208.4°  F.),  at  which  tempera- 
ture it  suffers  partial  decomposition  into  chloral  and  H2O;  volatilizes 
slowly  at  ordinary  temperatures;  is  very  soluble  iu  H2O;  neutral  in 
reaction;  has  an  ethereal  odor,  and  a  sharp,  pung^ent  taste.  Concen- 
trated H2SO4  decomposes  it  with  formation  of  chloral  and  chloralid. 
HNO3  converts  it  into  trichloracetic  acid.  When  pure  it  gives  no 
precipitate  with  silver  nitrate  solution,  and  is  not  browned  by  con- 
tact with  concentrated  H28O4,  Under  the  influence  of  sunlight  it  is 
violently  decomposed  by  potassium  chlorate,  which  oxidizes  it  in  part 
to  trieblorncetic  aeid;  ehlorin,  phosgene  gas,  earljon  dioxid,  and 
chloroform  are  given  off,  and  after  a  time,  crystals  of  potassium  tri- 
chloracetate  separate  from  the  cooled  mixture, 

Chlonil  also  combines  with  alcohol,  with  elevation  of  tem- 
perature, to  form  a  solids  crystalline  body— chloral  alcoholate: 
CCl3CH^^Q_^^2^ 

Action  of  Chloral  Hydrate  upon  the  Economy. — Although  it 
was  the  ready  decomposition  of  chloral  into  a  formate  and  chloroform 
which  first  suggested  its  use  as  a  hypnotic  to  Liebreich,  and  although 
this  decomposition  was  at  one  time  believed  to  occur  in  the  body 
under  the  influence  of  the  alkaline  reaction  of  the  blood,  more  recent 
investigations  have  shown  that  the  formation  of  chloroform  from 
chloral  in  the  blood  is,  to  say  the  least,  highly  improbable,  and  that 


ALDEHYDES    AND    KETONES 


305 


has,  in  common  mtli  umny  otht^r  chlorinated  derivatives  of 
series,  the  property  of  acting  directly  upon  the  nerve- centers. 

Neither  the  urine  nor  the  expii-ed  aii-  contains  chloroform  when 
loral  is  taken  internally;  aud  when  taken  in  large  doses,  chloral 
Happears  in  the  urine.  The  fact  that  the  action  of  chloral  is  pro- 
longed for  a  longer  period  than  that  of  the  other  ctiloriiiated  deriva- 
tires  of  the  fatty  series  is  probably  due,  in  a  great  measure,  to  its 
less  volatiiity  and  le2;;8  rapid  eliniiuation. 

When  taken  in  overdose,  chloral  acts  as  a  poison,  and  its  use  as 
8ti^h  is  rapidly  increasing  as  acquaintance  with  its  powcr^s  becomes 
more  widely  disseminated.  A  strong  aqueous  solution  is  frequently 
added  by  criminals  to  intoxicants  to  deprive  their  victims  of  con- 
soiousness  (knock-out  drops). 

No  chemical  antidote  is  known.  The  treatment  should  he  directed 
to  the  removal  of  any  chloral  remaining  in  the  stomach  by  the 
syphon,  and  to  the  maintenance  or  restoration  of  respiration. 

In  fatal  cases  of  poisoning  by  chloral  that  substance  may  be 
detected  in  the  blood,  urine,  and  cunt  eats  of  the  stomach  by  the 
foUowing  method:  the  liquid  is  rendered  strongly  alkaline  with  po- 
tassium hydroxid;  placed  in  a  flask^  which  is  warmed  to  50°-60° 
(122*^-140°  F.),  and  through  which  a  slow  curi-ent  of  air,  heated 
to  the  same  temperature,  is  ninde  to  pass;  the  air,  after  bubbling 
through  the  liquid,  is  tested  for  chloroform  by  the  methods  described 
on  page  279.  As  chloral  distils  with  vapor  of  water  from  acid  solu- 
tions, and  as  it  gives  tlic  same  reactions  as  chloroform,  except  the 
flaoreseence  with  the  rcsorcinul  reaction  (p,  -79),  Ihe  presence  of 
chloral  as  such  can  only  be  positively  demonstrated  by  extraction  of 
the  crystals  of  the  hydrate  by  ether,  and  spontaneous  evaporation  of 
the  ethenml  solution. 

Bromal — CBnuCHO — 281.— A  colorless,  oily,  pungent  liquid;  sp» 
^.  3.34;  boils  lit  IT^i""  {341.6°  F.);  neutral;  soluble  in  il^O,  alcohtil, 
mod  ether.  It  combines  with  H^O  to  form  bromal  hydrate,  CBra* 
CIKOH):;;  large  transparent  crystals;  soluble  in  H2O;  decomposed 
by  alkalies  into  bromoform  and  a  formate.  Produces  anesthesia 
witboQt  sleep;  very  poisonous. 

Thioaldehydes.— By  the  action  of  H2S  on  aldehyde  in  the  pres- 
eoee  of  HCl  two  products  are  obtained,  having  the  composition 
(CHjCHS)^,  known  as  «t  and  /?  TrithioacetaMehyde.  The  former 
is  in  large  prismatic  crystals,  fusible  at  101°  (213.8°  F.),  the  latter  in 
long  needles,  fusible  at  125''-126°(257°-258.8°  F.). 

Propaldehyde  —  Propionic  aldehyde  —  (  H^.  C  Hi.  CHO —  58  —  ob- 
tained by  the  general  reaction  from  proiiyhc  alcohol .  is  a  colorless 
liquid,  resembling  acetic  aldehyde;  boils  at  40^  (120.2'  FJ. 

Narmal  Butaldehyde— Butyric  aldehyde— UH^j.CH^CHa. CHO— 
20 


306  MANUAL    OF    CHEMISTRY 

72— is  an  oily  liquid,  boiling  at  73°  (163.2°  P.).  Its  trichlorinated 
<lerivative,  Trichlorbutaldehyde,  or  Butyric  chloral,  CCl8.CH2.CH2.- 
CHO — is  the  substance  whose  hydrate  is  used  as  a  medicine  under  the 
name  croton  chloral  hydrate.  It  is  a  colorless  liquid,  b.p.  160°,  ob- 
tained by  the  action  of  CI  an  acetaldehyde. 

Acetals — Formals. — These  are  ester-like  bodies  (p.  358)  corre- 

sponding  to  the  hypothetical  aldehyde  hydrates:  CHa.CHs^Qg,  which 

are  themselves  incapable  of  existence,  except  they  contain  a  halogen,  as 

in  chloral  hydrate:  CCIs-CH^^qq.    The  acetals  have  the  general  for- 

mula:  R^'.CH^^Qjj',  and  the  formals  the  structure:  CH2\oR'»  ^^  ^^^^'^ 
R''  represents  an  alkyl.  The  acetals  are  produced  by  oxidation  of  the 
alcohols  by  Mn02  and  H2SO4.  Thus,  6CH3.CH20H+02=2CH3.CH- 
(OC2H5)2+4H20,  and  by  other  methods.  The  formals  are  formed  by 
(condensation,  in  presence  of  H2SO4,  or  of  Fe2Cl6,  of  alcohols  and 
formic  aldehyde:  2CH8.CH20H+H.CHO=CH3.CH2.0.CH2.0.CH2.- 
CH3+H2O. 

The  formation  of  acetals  and  formals  is  utilized  in  the  preparation 
of  certain  aldehydes,  such  as  glyceric  aldehyde.  By  hydrolysing 
agents,  as  by  heating  with  aqueous  HCl,  they  are  split  into  their  com- 
ponents: CH3.CH(O.C2H6)2+H20=CH3.CHO+2CH8.CH20H. 

Methylal— Formal— CH2<(3chJ~76— is  formed  by  distUling  a 
mixture  of  Mn02,  methyl  alcohol,  H2SO4  and  H2O.  It  is  a  colorless 
liquid;  sp.  gr.  0.8551  at  17°  (62.6°  F.);  boiling  at  42°  (107.6°  F.); 
soluble  in  H2O,  alcohol,  and  oils.  It  has  a  burning,  aromatic  taste, 
and  an  odor  resembling  those  of  chloroform  and  acetic  acid.  It  has 
been  used  as  a  hypnotic. 

Acetal— CH3.CH<^^^H6— I^^a  colorless  liquid,  boils  at  lO*"" 
(219.2°  F.),  sp.  gr.  0.8314;  sparingly  soluble  in  H2O,  readily  in  al- 
cohol; obtained  by  heating  a  mixture  of  aldehyde,  alcohol  and  glacial 
acetic  acid,  or  in  the  same  manner  as  formal,  using  ethylic  in  place  of 
methylic  alcohol. 

Dialdehydes — containing  two  CHO  groups,  such  as  Glyoxal — 
CHO.CHO,  are  also  known.  Glyoxal  is  formed  by  the  limited  oxidii- 
tiou  of  acetic  aldeliyde  by  nitric  acid:  CH3.CHO+02=CHO.CHO 
+1120.  But  \'c  has  not  been  obtained  pure,  containing  oxalic  and 
formic  acids  as  impurities.  It  is  very  soluble  in  water,  and  has  the 
eliemieal  properties  common  to  the  aldehydes.  By  the  action  of  hy- 
drolysing agents,  such  as  BaH202,  or  CaH202,  one  aldehyde  group  is 
oxidized  to  a  carboxyl,  and  the  other  is  reduced  to  a  methoxyl: 
CHO.CHO+H20=CH20H.COOH.  When  warmed  with  ammonia 
and  formic  aldehyde  it  produces  glyoxalin  by  condensation  (p.  514). 


KETONES    OR    ACETONES  307 

'x  KETONES  OR  ACETONES. 

The  ketones,  or  acetones,  contain  the  group  C:0:,  linking  two 

hydrocarbon  groups;  or  they  may  be  considered  as  derived  from  the 

hydrocarbons  by  substitution  of  0  for  H2  in  a  CH2  group.    The  mono- 

ketones  contain  one  CO  group,  the  diketones  two,  etc.    The  (CO)'' 

g^ronp  also  occurs  in  the  aldehydes,  in  which,  however,  it  is  linked 

with  H,  (OrC.H)'',  and  in  the  carboxyl  group,  in  which  it  is  linked 

with  OH,  (OiC.OH)'',  in  both  cases  occupying  a  terminal  position. 

while  in  ketones,  ketonic  acids,  etc.,  its  position  is  intermediate. 

Ketones  are  symmetrical  if  the  two  alkyls  united  by  CO  are  similar, 

ansymmetrical  if  they  are  different: 

CH3 
CH3  I 

I  CO 

COOH  CO  I 

I  I  CH, 

CH,  CH3  I 

CH3 
Aeetle  acid.  Dimethyl  ketone  Methyl-ethyl  ketone, 

(acetone). 

Ketones  are  isomeric  with  and  closely  allied  to  the  aldehydes,  from 
which  they  differ  chiefly  in  that:  (1)  They  are  not  so  easily  oxidized, 
do  not  reduce  alkaline  solutions  of  silver  salts,  and,  on  oxidation, 
split  at  the  CO  group  to  form  a  carboxylic  acid  or  acids,  or  ketones, 
of  less  carbon  content:  CH8.CO.CH3+202=CH3.COOH+C02+H20; 
(2)  Nascent  hydrogen  converts  them  into  secondary  alcohols  by  addi- 
tion: CH3.CO.CH3+H2=CH3.CHOH.CH3.  (3)  The  ketones  do  not 
polymerize;  (4)  Only  those  ketones  which  contain  a  methyl  group 
form  crystalline  compounds  with  alkaline  bisulfites. 

The  monoketones  are  produced:  (1)  By  oxidation  of  the  secondary 
alcohols:  2CH3.CHOH.CH3+02=2CH3.CO.CH3+2H20;  (2)  By  dis- 
tillation of  the  calcium  salts  of  the  fatty  acids:  Ca(CH3.COO)2=CH3.- 
CO.CHa+CaCOs;  (3)  By  decomposition  of  ketonic  acids  (p.  347): 
CH3.CO.CH2.COOH=C02+CH3.CO.CH3;  (4)  By  the  interaction  of 
ziuc  alkyls  (p.  375)  and  acidyl  halids  (p.  352) :  Zn(CH3)2+2CH3.CO.- 
Cl=2CH3.CO.CH3+ZnCl2;  (5)  By  the  action  of  sodium  upon  a  mix- 
ture of  acidyl  and  alkyl  halids:  CH8.CO.Cl.+CH3l=CH3.CO.CH8+ 
NaCl+Nal. 

Dimethyl  Ketone — Acetone — Acetylmethylid — Pyroacetic  ether  or 
spirit — CO^cHa — 58 — is  formed  as  one  of  the  products  of  the  dry 
distillation  of  the  acetates;  by  the  decomposition  of  the  vapor  of 
acetic  acid  at  a  red  heat ;  by  the  dry  distillation  of  sugar,  tartaric 
acid,  etc.;  and  in  a  number  of  other  reactions.  It  is  obtained  by 
distilling  dry  calcium  acetate.  It  is  also  formed  in  large  quantity  in 
the  preparation  of  anilin. 


308 


MANUAL    OF    CHEMISTRY 


It  is  a  limpid,  colorless  liquid;  sp.  gr.  0.7921  at  18°  (64.4°  P.); 
boils  at  56°  (132.8° P.);  soluble  in  H2O,  alcohol  and  ether;  has  a 
peculiar  ethereal  odor  and  a  burning  taste;  is  a  good  solvent  of 
resins,  fats,  camphor,  gun-cotton;  readily  infla^mmable.  It  forms 
crystalline  compounds  with  the  alkaline  bisulfites.  CI  and  Br,  in  the 
presence  of  alkalies,  convert  it  into  chloroform  or  bromoform;  CI 
alone  produces  with  acetone  a  number  of  chlorinated  products  of  sub- 
stitution. Certain  oxidizing  agents  transform  it  into  a  mixture  of 
formic  and  acetic  acids;  others  into  oxalic  acid. 

Acetone  has  been  found  to  exist  in  the  blood  and  urine  in  certain 
pathological  conditions,  and  notably  in  diabetes.  The  peculiar  odor 
exhaled  by  diabetics  is  produced  by  this  substance,  which  has  also 
been  considered  as  being  the  cause  of  the  respiratory  derangements 
and  coma  which  frequently  occur  in  the  last  stages  of  the  disease. 

That  acetone  exists  in  the  blood  in  such  cases  is  certain:  it  is  not 
certain,  however,  that  its  presence  produces  the  condition  designated 
as  acetonsemia.  It  can  hardly  be  doubted  that  the  acetone  thus  ex- 
isting in  the  blood  is  indirectly  formed  from  diabetic  sugar,  and  it  is 
probable  also  that  a  complex  acid,  known  as  ethyldiacetic,  CcHgOsH,  is 
formed  as  an  intermediate  product. 

See  aromatic  ketones. 

Diketones,  containing  two  CO  groups,  such  as  CHa.CO.CO.CHs* 
triketones,  such  as  CH3.CO.CO.CO.CH3,  and  tetraketones,  snch  as 
CH3.(CO)4.CH8,  are  also  known. 

ALDEHYDE-ALCOHOLS,    KETONE -ALCOHOLS,    ALDEHYDE- KETONES, 
AND    OXYALDEHYDE-KETONES. 

These  bodies  are,  as  the  names  indicate,  substances  of  mixed  func- 
tion. The  known  oxyaldehyde- ketones,  aldehyde -ketones,  and  such  of 
the  aldehyde-  and  ketone -alcohols  as  contain  hydrocarbon  groups  are 
neither  numerous  nor  important.  The  following  formulse  indicate 
their  structures 


CHO 

I 
CO 

I 
CH20H 

Oxyaldebyde- 

ketone. 

Oxypyroracemio 

aldehyde. 


CHO 
I 
CO 

I 
CH3 

Aldehyde- 
ketone. 
Methyl 
Qlyozal. 


CHO 

I 
CHOH 

I 

CaHs 
Aldehyde- 
alcohol. 
AldoL 


CH2OH 

I 
CO 

CH3 

Ketone 
aloohoL 
AeetoL 


The  aldehyde -alcohols,  such  as  aldol  and  glycolyl  aldehyde: 
CH2OH.CHO,  are  called  oxyaldehydes ;  and  the  ketone-alcohols  such 
as  acetol  are  called  ketols. 


i 


ALDEHYDE  -  ALC0HOL8-KET0NE-  ALCOHOLS,  ETC. 


309 


I 


CAKB0HYDRATE8. 

The  definition  of  tlie  term  carbohydrate  as  "a  substance  of  un- 
known constitution  composed  of  carbon,  hydrogen  and  oxygen,  in 
which  the  oxygen  and  hydrogen  are  in  the  same  proportion  as  in 
water"  was  self-destmctive  so  soon  as  the  constitution  of  these  sub- 
stances should  become  known,  as  it  now  has.  Yet  the  first  words  of 
the  definition  were  necessary  to  exclude  substances  such  as  acetic  acid, 
CsH<02t  which  would  otherwise  accord  with  the  definition,  yet  were 
never  considered  as  carbohydrates.  But»  while  the  sugars  and 
starches  have  been  thus  removed  from  the  ** miscellaneous"  residuum 
of  our  chemical  classification,  they  are  still  conveniently  referred  to 
as  carbohydrates  in  physiological  chemistry. 

The  simplest  of  the  carbohydrates  are  oxyaldehydes  or  ketols  in 
which  all  the  groups,  other  than  the  aldehyde  or  ketone  gi^oups,  are 
primary  or  secondary  alcoholic  groups;  and  the  more  complex  con- 
sist of  two  or  more  molecules  of  the  simpler  forms,  united  with 
elimination  of  water. 

The  carbohydrates  are  classified  into: 

Monosaccharids,  or  Monoses  —  which  do  not  yield  any  other 
sugar  or  sugars  by  the  action  upon  them  of  dilute  acids  (glucose, 
tmclose,  galactose,  etc  J; 

Disaccharids,  or  Saccharobioses — which,  under  the  influence  of 
dilute  acids,  take  up  H2O  and  yield  two  other  sugar  molecules  (sac- 
charose, lactose,  maltose,  etc.); 

Trisaccharids,  or  Saccharotrioses — which,  under  the  same  in- 
floenee,  take  up  2H2O  and  yield  three  other  sugar  molecules;   and 

Polysaccharids — which,  under  the  same  influence,  take  up  more 
than  2H2O,  and  yield  more  than  three  sugar  molecules  (starches, 
irniiis,  celluloses,  etc.). 

The  disaccharids,  trisaccharids  and  polysaccharids  may  be  consid- 
ered as  produced  by  the  fusion  of  two  or  more  monosaccharid  mole- 
cules with  elimination  of  one  or  more  molecules  of  water. 

Those  carbohydrates  which  contain  the  ketone  group,  CO,  are 
called  ketoses.  those  containing  the  aldehyde  group,  CHO»  aldoses. 
The  names  of  all  carbohydrates  terminate  in  ose. 


MONOSACCHARIDS-^MONOSES. 

Monosaccharids  are  dioses,  trioses*  tetroses,  pentoses,  hexoseSt 
lieptoses,  octoses  or  nonoses  according  ns  they  contain  from  two  to 
nine  carbon  atoms.    (See  table  on  next  page.) 

The  monosaccharids  are  neutral  substances,  sweet,  odorless,  white, 
insoluble  in  ether,  sparingly  soluble  in  alcohol,  and  readily  soluble  in 


310 


MANUAL    OP    CHEMISTRY 


^ater.  Like  all  aldehydes  and  ketones,  they  are  readily  oxidized,  and 
in  their  oxidation  act  as  reducing  agents.  It  is  upon  this  quality  that 
the  several  "reduction  tests,"  such  asTrommer's,  Fehling's,  Barfoed's, 
Boettger's  Mulder- Neubauer's,  etc.,  are  based.  Another  quality  of 
the  monosaccharids,  utilized  for  their  separation  and  identification,  is 
that  they  all  give  crystalline  precipitates  of  substances  called  osazones 
when  their  solutions,  acidulated  with  acetic  acid,  are  heated  with 
phenyl -hydrazin,  C6H6.H:N.N:H2.  The  trioses,  hexoses  and  nonoses 
are  capable  of  alcoholic  fermentation,  the  others  are  not.  Most  of 
the  monosaccharids  are  optically  active. 

Aldoses, 
CHO        CHO         CHO  CHO  CHO  CHO  CHO  CHO 

I  I 

CH2OH    CHOH 

i: 


(CHOH)2 
HjOH    CH2OH 


CHO 
(CH0H)3 
CH2OH 


CHO 

(CH0H)4 
I 
CH2OH 


CHO 
(CH0H)5 
CH2OH 


(CHOH)e    (CHOH)t 
I  I 

CH2OH       CH,OH 


Ketoses, 

CH2OH    CH2OH 

I  I 

CO  CO 

I        I 

CH2OH    CHOH 

I 
CH2OH 

DiofM.      Trioses.     TetroJes. 


CH2OH 

I 
CO 


CH20H      CH20H 


CH30H  CH20H 

I  I  I  I 

CO  CO  CO  CO 

I  I  I  I  I 

(CHOH)  2    (CHOH)3  (CH0H)4  (CH0H)6  (CHOH)« 

I  I  I  I  I 

CH2OH       CH2OH  CH2OH  CH2OH  CH,OH 

Pentoses.        Hexoses.  Heptosee.  Oetosas.  Nonoaee. 


DIOSES,    TBIOSES,   TETBOSES  AND  PENTOSES. 

Glycolyl  aldehyde,  CH2OH.CHO,  is  the  only  diose  possible.  It  is 
produced  by  the  action  of  baryta  water  upon  brora-acetaldehyde. 

Of  the  two  possible  trioses  Glyceric  aldehyde  is  obtained  by  start- 
ing from  acrolein  acetal.  This  is  oxidized  to  glyceric  acetal:  2CH2:- 
CH.CH(O.C2H5)2+202+2H20=2CH20H.CHOH.CH(O.C2H6)2;  which 
is  then  hydrolized:  CH20H.CHOH.CH(O.C2H5)2+H20=CH20H.- 
CHOH.CHO+2CH3.CH2OH.  Glycerol  ketone,  or  dioxyacetone,CH2.- 
OH.CO.CH2OH,  has  also  been  obtained  synthetically.  The  aldehyde 
and  ketone  are  formed  together  when  glycerol  is  oxidized  by  dilute 
nitric  acid. 

Similarly  erythrose  is  a  mixture  of  the  two  tetroses,  CHO.- 
(CHOH)2.CH20H  and  CH2OH.CHOH.CO.CH2OH,  formed  by  oxida- 
tion of  erythrol  by  dilute  nitric  acid. 

The  pentoses  hitherto  described  are  all  aldo- pentoses,  CiHs- 
<0H)4.CH0,  although  keto-peutoses  probably  also  exist.  When 
distilled  with  hydrochloric  or  dilute  sulfuric  acid  they  yield  furfurole: 

^CH:CH 

a  reaction  which 


/^ 


CHO.(CHOH)3.CH20H=3H20+CHO.C^ 

is  utilized  for  their  quantitative  determination.    Arabinose  is  a  pen- 


CH.O 


iLLDEHYDE-ALCOHOLS— KETONE-AIiCOHOLS,  ETC. 

tOi^e  obtained  by  tlie  atitioii  of  dilute  sulfuric  acid  upou  cherry  gum. 
Xylose,  or  wood  sugar,  is  produced  by  boiling  wood-guna  with  dilute 
acid,  Ribose  is  a  synthetic  product.  Rhamnose,  or  Isodulcite, 
Chinovose,  and  Fucose  are  methyl -pentoses:  CHa.{CH0H)4.CH0, 
obtaiued  by  the  decooi position  of  certaiu  glucosids  or  from  sea  weeds. 
'These  pentoses  result  from  the  hydrolysis  of  peutosaues,  polysacehar- 
ids  oecurring  as  gums  in  plauts.  Pentoses  have  also  been  found  in 
the  urine,  particularly  in  diabetes  and  after  the  use  of  certain  fruits 
containing  peutosanes.  They  are  also  among  the  products  of  decom- 
position of  certain  uucleoproteids.  Pentoses,  when  warmed  with 
hydrochloric  acid  in  presence  of  phloroglucin,  give  a  fine  red  color, 
and  a  sharp  absorption  band  near  the  Na  line. 


HEXOSES— GLUCOSES . 

In  this  class  are  included  some  wTll-known  sugars,  such  as  glucose 
and  fructose,  which  occur  free  in  the  vegetable  world.  They  exist  in 
€ther-like  combination  in  many  of  the  glucosids  {p.  465), 

They  are   mostly  sweet,  crystalliuc   substances,  very  soluble   in 

water,  and  diflficnltly  soluble  in  alcohol.     They  are  formed  by  {!)  the 

, liydrolysis  of  the  di-  and  polysacdiarids:    Ci2H220n  +  n-0=2CaHi20fl; 

(2)    b3'  oxidation   of   the  correspundiug   hexatomic  alcohol;     (H)   by 

reduction  of  the  lactones  of  the  mouucarboxylic  acids  (p,  368). 

They  exhibit  the  usual  reactions  of  the  alcohols  and  those  of  the 
laidehydes  or  ketones,     Oo  reduction  they  produce  hexatomic  alcohols; 
Isnd  on  oxidation  they  yield  nionocarboxylic  acids.    Their  alcoholic  hy- 
drogen is  replaceable  by  certain  metals  with  formation  of  sacchar- 
atea,  corresponding  to  the  alcoholates  (p.  286).     With  acids   they 
yield  esters.    They  form  osazoncs  with  phenylhydrazin.     Some  are 
very  prone  to  alcoholic  fermentation:  CBHi20ei=2C2H60+2C02,  while 
otbers  readily  undergo  lactic  fei-mentation :  CcHi20B=2CHne03.    Being 
L polyatomic  alcohols ^  the  hexoses  form  insoluble  benzoic  esters  when 
|tbeir  alkaline  solutions  are  shaken  with  benzoyl  chlorid  (p.  298). 

Of  the  described  hexoses,  mannose,  glucose,  gulose,  idose,  galac- 
[tose  and  talose  are  aldoses;  fructose  and  sorbinose  are  ketoses. 

Optical   Activity.^ — All  of  the   hexoses  exist  in   three  isomerids, 

liifering  from  each  other  in  their  action  upon  polarized  light.     One 

>f  tfaeae  rotates  the  plane  of  polarization  to  the  rigfht,  and  is  desig- 

itad  as  the  dextro-,  or  d-compound;  another  is  laevogyrous  and  is 

leaignated  as  the  la*vo-,  or  1-compound,  while  the  third  is  inactive, 

^mnd  is  disting-uisiied  hy  tlie  sytiibol  (d  +  O- 

Stereoisomerism,  or   Space  Isomerism, — The  grapljic  formuJa) 

idioate  the  structure  of  the  molecule  only  partially;    they  show  that 

atoms  in  the  molecule  are  attached  to  some  of  their  fellows 


312  MANUAL    OF    CHEMISTRY 

more  closely  than  to  others,  but  they  give  no  indication  of  the  posi- 
tions which  the  atoms  occupy  in  space  with  regard  to  each  other. 

H\ 
The  expression      C— 0— H,  the  most  completely  detailed  graphic 

H/  I 

representation  of  that  group,  indicates  at  the  most  that  the  two  hy- 
drogen atoms  are  attached  to  one  side  of  the  carbon  atom,  while  the 
hydroxyl  is  attached  to  another.  Stereochemistry  is  that  branch  of 
chemistry  treating  of  the  relations  of  the  atoms  to  each  other  in  space. 
It  has  been  greatly  developed  in  recent  years  and  affords,  among  other 
things,  the  fii*st  rational  explanation  of  the  cause  of  the  differences  in 
the  optical  activity  of  the  hexoses,  as  well  as  of  lactic  and  tartaric 
acids,  and  of  many  other  substances. 

If  we  suppose  that  differences  in  the  relative  positions  which 
atoms  or  groups  attached  to  carbon  atoms  occupy  with  relation  to 
each  other  produce  different  compounds  (see  Place  Isomerism,  p.  339, 
Orientation,  p.  436);  and  if  we  also  suppose  that  the  four  valences 
of  the  carbon  atom  act  in  a  plane-*  and  at  right  angles  to  each  other,  a 
vast  number  of  space -isomerids  of  the  di-  and  poly -substituted  de- 
rivatives of  the  aliphatic  hydrocarbons  would  exist,  no  representatives 
of  which  are,  however,  known.  For  example,  marsh -gas  would  yield 
two  isomerids  of  each  of  the  types:  CH2X2,  CH2XY  and  CH(X)2Y, 
and  three  isomerids  of  the  type  CHXYZ,  in  which  X,  Y,  and  Z  rep- 
resent any  three  univalent  atoms  or  radicals,  thus: 

H  H  H  H  H  H 

II  I  I  '  I 

CI— C— CI,  CI— C— H,    Br-C— CI,  H-<J— CI,  CI— C— CI.  CI— C— Br  ; 

II  I  I  I  i 

H  CI  H  Br  Br  CI 

Type  CH2X2.  Type  CH2XY.  Type  OHX2Y. 

H  H  H 

I  I  I 

CI— C— I,  I— C— Br,  and  Br— C— CI 

I  I  I 

Br  CI  I 

Type  CHXYZ. 

But  only  one  representative  of  each  of  these  types  is  known. 
Therefore  the  usual  graphic  representation  of  the  valences  of  the 
carbon  atom  as  above,  while  convenient,  is  not  spatially  consistent  with 
fact,  and  the  four  valences  of  the  carbon  atom  are  not  exerted  in 
one  plane. 

The  suggestion  of  Van't  Hoff  (following  the  somewhat  similar 
idea  of  Eekul^)  that  the  valences  of  the  carbon  atom  are  represented 
by  considering  it  as  occupying  the  iuterior  of  a  regular  tetrahedron, 
the  solid  angles  of  which  indicate  the  direction  of  its  valences  (Fig. 
40,  A),  taken  in  connection  with  the  hypothesis  of  an  asymmetric 
carbon  atom,  affords  a  rational  explanation  of  the  facts  just  cited, 


ALDEHYDE-ALCOHOLS— KET0NE-ALC0H0L8,  ETC. 


313 


♦       ^      <$► 


^ 


8 


and  of  the  differences  in  the  optical  properties  of  the  substances  men- 
tioned. 

Admitting  the  regular  tetrahedron  to  represent  the  arrangement  of 
the  valences  of  the  carbon  atom,  it  follows  that  all  carbon  atoms,  two 
of  whose  valences  are  satisfied 
by  the  same  kind  of  univalent 
atom  or  group,  and  the  other 
two   by  two  constant  but  dis- 
similar univalents,   must    be 
symmetrical.     The  two  similar 
univalents    must    occupy    the 
summits  at  the  extremities  of 
some  one  crest,  and  the  only 
possible  variation  in   arrange- 
ment  of   the   other   two  is  in 
their  position  with   regard  to 
this  crest.      Thus   B   and   C, 
Fig.  40,  although  dissimilar  in 
the  position  in  which  they  are 
placed,  become  perfectly  sym- 
metrical  when    either   one    is 
rotated  through   180   degrees. 
But  when  all  four  of  the  car- 
bon valences   are   satisfied  by 
different    univalents    two    ar- 
Tang^ments  are  possible,  pro- 
ducing two  molecular  groups 
'Which    are    unsymmetrical    in 
whatever  position  they  may  be 
placed.     Thus  D  and  E,  Fig. 
^*  are  unsymmetrical   in  the 
positions  in  which  they  are  re- 
PPeaented,  and  remain  so,  however  their  positions  may  be  changed. 
-A  carbon   atom  attached  to  four  different  univalents  is  called  an 
•^ynunetric  carbon  atom.    In  graphic  formulsB  asymmetric  carbon 
^tonaa  are  designated  by  the  italic  0,  or  by  an  asterisk,  C*.     Sub- 
staiices  containing  an  asymmetric  carbon  atom  exist  in  three  optical 
isoQi^i^g.  dextrogyrous  (d),  IcBvogyrous  (1),  and  optically  inactive,  or 
'^^^^mtc  (d+1  or  i,  orr). 

The  structure  of  the  four  isomeric  tartaric  acids  (p.  344)  was  first 

^^Plained  under  the  hypothesis  of  the  asymmetric  carbon  atom.    Ltt 

u  be  assumed  that  two  asymmetric  carbon  atoms,  with  their  attached 

^^^P8  or  atoms,  exert  a  "directing  influence"  upon  each  other,  and 

that,  being  attached  to  each  other  at  one  point  only,  they  are  capable 


Q-COOH    B>H       |-0H 


-CH,OH 


Fio.  40. 


314  MANUAL    OF    CHEMISTRY 

of  rotating  independently  about  a  common  axis  (a,a.  Fig.  40,  G),  such 
rotation  would  then  occur  in  obedience  to  the  directing  influence  until 
a  condition  of  equilibrium  is  reached,  in  which  position  the  atoms 
would  remain.  Assuming  this  position  to  be  that  shown  in  P,  G, 
and  H,  Fig.  40,  with  the  two  COOH  groups  in  like  relation,  then  the 
three  unsymmetrical  arrangements  shown  in  the  figure  are  possible. 
The  first  represents  the  structure  of  dextro- tartaric  acid,  G  that  of 
laevo- tartaric  acid,  and  H  that  of  meso-tartaric  acid,  while  racemic 
acid  is  a  combination  of  dextro-  and  Isbvo- tartaric  acids. 

The  tetrahedron  representation  of  the  carbon  valences  adapts  itself 
well  also  to  the  explanation  of  certain  isomerids  of  the  ethylene  series, 
in  which  two  carbon  atoms  are  doubly  linked  together.  In  these  the 
two  carbon  atoms  being  linked  together  at  two  points  (I  and  K,  Fig. 
40)  cannot  be  considered  as  being  capable  of  rotation,  and,  if  the  two 
other  valences  of  each  carbon  atom  are  satisfied  by  the  same  two  dis- 
similar univalents,  two  positions  are  possible:  I,  in  which  the  like 
univalents  are  directed  to  the  same  side,  called  the  "plane  symmetri- 
cal configuration,"  and  K,  in  which  they  are  directed  towards  opposite 
sides,  called  the  "axially  symmetrical  configuration." 

Formose  is  a  synthetic  hexose,  obtained  by  polymerization  of 
formic  aldehyde:  6H.CHO=C6Hi206.  Acrose  is  similarly  obtained 
from  glyceric  aldehyde:  3CH20H.CHO=C6Hi206;  or  by  the  action  of 
barium  hydroxid  upon  acrolein  bromid:  2CH2Br.CHBr.CHO+2Ba- 
H202=C6Hi206+2BaBr2. 

Mannose  is  obtained,  as  d-,  1-,  and  d+1,  mannoses  by  oxidation  of 
the  corresponding  mannitols. 

Glucose  —  Grape  Sugar  —  Dextrose  —  Liver  Sugar  —  Diabetic 
Sugar — d-Glucose  occurs  in  many  sweet  fruits  and  vegetable  juices, 
and  in  honey,  accompanied  by  fructose;  and,  in  the  animal  world,  in 
the  contents  of  the  intestine,  liver,  bile,  thymus,  heart,  lungs,  blood, 
and,  in  small  quantity,  in  the  urine.  Pathologically,  it  appears  in  the 
saliva,  perspiration,  faeces,  and,  in  largely  increased  amount,  in  the 
blood  and  urine  in  diabetes  mellitus.  It  is  produced  by  the  decompo- 
sition of  the  polysaccharids  and  of  many  of  the  glucosids,  and  is  manu- 
factured on  a  large  scale  by  the  action  of  boiling  dilute  H2SO4  upon 
starch.  The  commercial  product  so  obtained  is  either  an  amorphous, 
white  solid  (grape  sugar),  containing  about  60%  of  true  glucose, 
along  with  dextrins  and  the  unfermentable  isomaltose,  or  gallisin, 
C12H22OU  ;  or  a  thick,  colorless  syrup  (glucose),  containing,  be- 
sides the  above,  a  minute  quantity  of  a  nitrogenous  body  which 
exerts  a  solvent  action  upon  coagulated  albumin  at  the  body  tem- 
perature. 

d'Olucose  has  been  produced  synthetically  by  the  reduction  of  the 
lactone  of  d-gluconic  acid  (p.  343). 


ALDEHYDE- ALCOHOLS  —  KETONE- ALCOHOLS,  ETC.  315 

It  crystallizes  from  its  aqaeous  solutions  at  the  ordinary  temper- 
atnre  with  difficulty  in  white,  opaque,  spheroidal  masses  containing 
lAq,  which  fuse  at  86^  and  lose  the  Aq  at  110^.  From  its  concen- 
trated aqueous  solution  at  30^  to  35^,  or  from  its  alcoholic  solution  it 
crystallizes  in  hard,  anhydrous,  crystalline  crusts,  which  fuse  at  146^. 
It  is  soluble  in  all  proportions  in  hot  water,  is  very  soluble  in  cold 
water,  and  soluble  in  alcohol.  It  is  less  sweet  and  less  soluble  than 
<»ne  sugar.  Its  aqueous  solutions  are  dextrogyrous:  [a]D=+52.6°  in 
boiled  solutions.  Freshly  prepared  cold  aqueous  solutions  have 
nearly  double  that  rotary  power  at  first,  the  value  of  [a]  d  gradually 
falling  to  52.6°  in  about  twenty -four  hours.  Its  osazone,  d-glucosa- 
sone,  crystallizes  in  needles,  fusible  at  205°.  Its  solutions  dissolve 
baryta  and  lime,  with  which,  as  with  potash,  soda,  and  the  oxids  of 
Pb  and  Cu,  it  forms  saccharates. 

I'Olucose  is  formed  by  reduction  of  the  lactone  of  1-gluconic  acid. 
It  is  in  all  respects  similar  to  d- glucose  except  that  it  fuses  at  143°, 
and  its  solutions  are  IsBVogyrous  [a]D= — 51.4°. 

d-^l'Olucose  is  formed  by  reduction  of  d+l-gluconic  lactone; 
or  by  union  of  d-  and  1-glucose.  Its  solutions  are  optically  inac- 
tive. 

Galactose  is  also  known  in  its  three  modifications,  d- Galactose 
is  produced  by  the  hydrolysis  of  milk  sugar  and  of  certain  gums.  It 
crystallizes  more  readily  than  glucose,  is  very  sparingly  soluble  in 
cold  alcohol,  has  a  specific  rotary  power  of  [a]D=+83.33°,  and  fuses 
at  160°.  By  reduction  it  yields  dulcite,  and  by  oxidation  galactonic 
acid,  CH2OH.  (CH0H)4.C00H,  and  mucic  acid,  COOH.  (CH0H)4. 
COOH.  Cerebrose,  obtained  by  the  hydrolysis  of  cerebrin,  a  con- 
stituent of  nerve  tissue,  is  identical  with  galactose. 

Fructose,  a  ketohexose,  exists  in  the  three  modifications.  d-Fmc- 
lose — LcBvulose — Fruit  sugar — forms  the  uncrystallizable  portion  of 
the  sugar  of  fruits  and  of  honey,  in  which  it  is  associated  with  glu- 
cose; it  is  produced  artificially  by  the  prolonged  action  of  boiling 
nvater  upon  inulin,  a  polysaccharid;  also,  along  with  an  equal  quan- 
tity of  glucose,  as  one  of  the  constituents  of  invert  sugar,  by  the 
decomposition  of  cane  sugar  ;  and  from  d-glucosazone.  It  crys- 
tallizes with  gi-eat  difficulty,  fuses  at  95°,  is  very  soluble  in  water, 
and  insoluble  in  absolute  alcohol.  Although  called  d -fructose,  be- 
cause of  its  formation  from  d-glucosazone,  it  is  strongly  Isbvo- 
rotary:  [a]D= — 71.4°.  It  is  less  readily  fermentable  than  glucose, 
which  it  equals  in  the  readiness  with  which  it  reduces  cupro- 
potassic  solutions.  With  phenylhydrazin  it  yields  d-glucosazone 
(p.  485). 

Sorbinose,  also  a  ketohexose,  occurs  in  the  berries  of  the  moun- 
tain ash.     It  does  not  ferment.     Its  osazone  fuses  at  164°. 


316  MANUAL    OP    CHEMISTRY 

DISACCHARIDS — SACCHAROBIOSES . 

Disaccharids  consist  of  two  molecules  of  moDOsaecharids,  united 
with  elimination  of  H2O.  So  far  as  is  known  they  are  all  derived 
from  the  hexoses,  and  their  formula  is  consequently  C12H22OU.  They 
are  all  capable  of  yielding  two  hexose  molecules  by  hydrolysis: 
Ci2H220u+H20=2CJ3i206,  a  change  which  is  called  "inversion."  The 
union  of  the  two  monosaccharid  molecules  is  either  through  the  alde- 
hyde, ketone,  or  alcoholic  groups.  Of  the  three  most  important  disac- 
charids, saccharose,  lactose  and  maltose,  the  first  named  has  no  reduc- 
ing power,  and  yields  no  osazone  with  phenylhydrazin.  It  therefore 
contains  no  aldehyde  or  ketone  group.  When  heated  with  acetic 
anhydrid  to  160°  it  forms  an  octacetyl  ester,  Ci2Hi403(O.C2B[30)8.  It 
therefore  contains  eight  hydroxyls.  When  hydrolyzed  it  yields  d-glu- 
cose  and  d- fructose  (laevogyratory).  Prom  the  above  facts  we  may 
infer  that  saccharose  is  derived  from  the  two  hexoses  named,  united 
through  the  aldehyde  and  ketone  groups,  a  constitution  which  may  be 
represented  by  the  formulsB: 

CH20H.CO.(CHOH)2.CHOH.CH20H  CH0.(CH0H)4.CH,0H 

d-FraetoM.  d*GIaooM. 


CH20H.CH.(CHOH)2.C.CH20H.         CH.(CH0H)4.CH, 
Saechnrosa. 

Lactose  and  maltose  both  cause  reduction  and  yield  osazones.  On 
hydrolysis  the  former  yields  d- glucose  and  galactose,  and  the  latter 
only  d-glucose.  They  each  consequently  retain  an  aldehyde  (or 
ketone)  group,  and  their  constitution  may  probably  be  represented 
thus: 

'  CH20H.CHOH.CH.(CHOH)2.CH.O.CHo.(CHOH)4.CHO         and 

/0\ 
CHO.(CHOH>4.CH2   CH2.(CHOH)4.CHO 

The  disaccharids  are  hydrolyzed  by  boiling  with  very  dilute  acids, 
or  even  with  water,  and  by  several  enzymes  such  as  diastase,  eraulsin, 
invertin,  ptyalin,  trypsin  and  pepsin. 

Saccharose  —  Cane  Sugar  —  exists  in  many  roots,  fruits  and 
grasses,  and  is  produced  from  the  sugar-cane,  Sacchartim  officifiamm, 
sorghum.  Sorghum  saccharatum,  beet,  Beta  vulgaris,  and  sugar-maple, 
Acer  saccharinum. 

For  the  extraction  of  sugar  the  expressed  juice  is  heated  in  large 
pans  to  about  100°  (212°  P.);  milk  of  lime  is  added,  which  causes 


ALDEHYDE- ALCOHOLS  -  KETONE- ALCOHOLS,  ETC. 

he  precipitation  of   albumin,  wax,  calcic  phosphate,  etc.;   the  clear 
1  iqoid  is  drawn  off,  and  'Melinied"^  by  passing  a  current  of  COa  through 
it 5  the  clear  liquid  is  agaiu  drawn  off  and  evaporated,  during  agita- 
tion, to  the  crystallizing  point;   the  product  is  drained,  leaving  what 
"is  termed  raw  or  muscovado  sugar,  while  the  liquor  which  drains  off 
is  molasses.     The  su^ar  so  obtained  is  purified   by  the  process  of 
^* refining,"  which  consists  essentially  in  adding  to  the  raw  sugar,  in 
solution,  albumen  in  some  form,  which  is  then  coagulated;  filtering 
first  through  canvas,  afterward  through  animal  charcoal;   and  evapo- 
rating the  clear  liquid  in  '■  vacuum -pans, ^^'it  a  temperature  not  exeeed- 
ting   72^    (161.6^^   F.),   to    tlie  crystallizing   point.     The   product  is 
allowed  to  crystallize  in  earthen  moulds;  a  saturated  solution  of  pure 
sugar  is  poured  upon  the  crystalline  mass  iu  order  to  displace  the 
uncrystallizable  sugar  which  still  remains,  and  the  loaf  is  finally  dried 
in  an  oven.     The  liquid  displaced  as  above  is  what  is  known  as  sugar- 
house  syrup. 

Pure  sugar  should  be  entirely  soluble  in  water;  the  solution  should 
not  turn  brown  when  warnn^d  with  dilute  pot^issium  hydrosid  solu- 
tion; should  not  reduce  Fehliug's  solution,  and  should  give  no  pre- 
cipitate with  ammonium  oxalate. 

Bcct-sogar  is  the  same  as  cane-sugar,  except  that,  as  usually  met 
with  in  commerce,  it  is  lighter,  bulk  for  bulk.  Sugar<candy,  or 
rock-candy,  is  cane-sugar  allowed  to  crystallize  slowly  from  a  concen- 
trated solution,  without  agitation.  Maple-sugar  is  a  partially  refined, 
but  not  decolorized  variety  of  cane-sugar. 

Saccharose  crystallizes  in  small,  white,  monoclinic  prisms;  or,  as 
sugar-eandy,  in  large,  yellowish,  transparent  crystals;  sp.  gr.  1,606, 
It  is  very  soluble  in  water,  dissulviug  in  about  one -third  its  weight 
of  cold  water,  and  more  abundantly  in  hot  water.  It  is  insoluble  in 
absolute  alcohol  or  ether,  and  its  solubility  in  water  is  progressively 
diminished  by  the  addition  of  aleohuL  Aqueous  solutions  of  cane- 
sugar  are  dextrogyrous,  [ff]D^=+66.5°, 

When  saccharose  is  heated  to  1C0°  (320'^  F.)  it  fuses,  and  the 
liquid,  on  cooling,  solidifies  to  a  yellow,  transparent^  amorphous  mass» 
known  as  barley-sugar ;  at  a  slightly  higher  temperature,  it  is  decom- 
posed into  glucose  and  la*vulosan;  at  a  still  higher  temperature,  H2O 
is  given  off,  and  the  glucose  already  formed  is  converted  into  glu- 
cosati;  at  about  200'^  (,192°  F.)  the  evolution  of  II-^O  is  more  abnn- 
dant,  and  there  remains  a  brown  material  known  as  caramel,  or 
burnt  sugar;  a  tasteless  substance^  insoluble  in  strong  alcohol,  but 
soluble  in  H2O,  or  in  aqueous  alcohol,  and  used  to  communicate  color 
to  spirits;  finally,  at  higher  temperatures,  methyl  hydrid  and  the  two 
oxids  of  carbon  are  given  off;  a  brown  oil,  acetone,  acetic  acid,  and 
aldehyde  distil  over;  and  a  carbonaceous  residue  remains. 


< 


318  MANUAL    OF    CHEMISTRY 

If  saccharose  be  boiled  for  some  time  with  H2O,  it  is  converted 
into  inverted  sugar,  which  is  a  mixture  of  glucose  and  fructose: 
Ci2H220u+H20=C6Hi206+CeHi206.  With  a  solution  of  saccharose 
the  polarization  is  dextrogyrous,  but,  after  inversion,  it  becomes 
laevogyrous,  because  the  left-handed  action  of  the  molecule  of  fruc- 
tose produced,  [a]D=  —  71.4°,  is  only  partly  neutralized  by  the  right- 
handed  action  of  the  glucose,  [a]D=+52.6°.  This  inversion  of  cane 
sugar  is  utilized  in  the  testing  of  samples  of  sugar.  On  the  other 
hand,  it  is  to  avoid  its  occurrence,  and  the  consequent  loss  of  sugar, 
that  the  vacuum -pan  is  used  in  refining — its  object  being  to  remove 
the  H2O  at  a  low  temperature. 

With  potassium  chlorate,  sugar  forms  a  mixture  which  detonates 
when  subjected  to  shock,  and  which  deflagrates  when  moistened  with 
H2SO4.  Concentrated  H^04  blackens  it.  Dilute  HNOa,  when  heated 
with  saccharose,  oxidizes  it  to  saccharic  and  oxalic  acids. 

When  moderately  heated  with  liquor  potasssB,  cane-sugar  does  not 
turn  brown,  as  does  glucose;  but  by  long  ebullition  it  is  decomposed 
by  the  alkalies,  much  less  readily  than  glucose,  with  formation  of 
acids  of  the  fatty  series  and  oxalic  acid. 

With  the  bases,  saccharose  forms  definite  compounds  called  suc- 
rates  (improperly  saccharates,  a  name  belonging  to  the  salts  of  sac- 
charic acid).  With  Ca  it  forms  five  compounds.  Calcium  hydroxid 
dissolves  readily  in  solutions  of  sugar,  with  formation  of  a  Ca  com- 
pound, soluble  in  H2O,  containing  an  excess  of  sugar. 

During  the  process  of  digestion,  probably  in  the  small  intestine, 
cane-sugar  is  inverted. 

Lactose — Milk  Sugar — Lactine—Saccharum  lactis  (U.  S.,  Br.) 
— occurs  in  the  milk  of  the  mammalia,  in  the  amniotic  fluid  of  cows, 
and  in  the  urine  of  women  towards  the  end  of  gestation  and  during 
lactation.  It  may  be  obtained  from  skim -milk  by  coagulating  the 
casein  with  a  small  quantity  of  H2SO4,  filtering,  evaporating,  redis- 
solving,  decolorizing  with  animal  charcoal,  and  recrystallizing. 

It  forms  prismatic  crystals;  sp.  gr.  1.53;  hard,  transparent, 
faintly  sweet,  soluble  in  6  parts  of  cold  and  2.5  parts  of  boiling 
H2O;  soluble  in  acetic  acid;  insoluble  in  alcohol  and  in  ether.  Its 
solutions  are  dextrogyrous  [a]D=-f52.5°.  The  crystals,  dried  at 
100°  (212''  F.),  contain  lAq,  which  they  lose  at  150°  (302°  F.). 

Lactose  is  not  altered  by  contact  with  air.  Heated  with  dilute  min- 
eral acids  or  with  strong  organic  acids,  it  is  converted  into  galactose. 
HNO3  oxidizes  it  to  mucic  and  oxalic  acids.  A  mixture  of  HNO3 
and  H2SO4  converts  it  into  an  explosive  nitro- com  pound.  With 
organic  acids  it  forms  esters.  With  soda,  potash  and  lime  it  forms 
compounds  similar  to  those  of  saccharose,  from  which  lactose  may  be 
recovered  by  neutralization,  unless  tliey  have  been  heated  to  100*^ 


ALDEHYDE-ALCOHOLS— KETONE-ALCOHOL8,  ETC.  319 

(212°  P.),  at  which  temperature  they  are  decomposed.  It  reduces 
Fehliug's  solution,  and  reacts  with  Trommer's  test.  Its  osazone  fuses 
at  200°  (392°  F.). 

In  the  presence  of  yeast,  lactose  is  capable  of  alcoholic  fermenta- 
tion, which  takes  place  slowly,  and,  as  it  appears,  without  previous 
transformation  of  the  lactose  into  glucose  aud  galactose.  On  contact 
with  putrefying  proteins  it  enters  into  lactic  fermentation. 

The  average  proportion  of  lactose  in  different  milks  is  as  follows: 
Cow,  5.5  per  cent.;  mare,  5.5;  ass,  5.8;  human,  5.3;  sheep,  4.2; 
goat,  4.0.     It  is  converted  into  galactose  by  the  pancreatic  secretion. 

Maltose — is  formed,  along  with  dextrins,  during  the  conversion 
of  starch,  or  of  glycogen,  into  sugar  by  the  action  of  diastase  (in 
malting  grain),  and  of  the  enzymes  of  the  saliva  and  the  pancreatic 
juice.  It  is  also  an  intermediate  product  in  the  hydrolysis  of  starch 
by  dilute  sulfuric  acid.  Maltose  crystallizes  in  hard,  white  needles 
aggregated  into  crusts.  It  is  less  soluble  in  alcohol  than  is  glucose^ 
and  has  a  much  higher  dextrogyratory  power  [a]  d=+ 137°.  It  re- 
duces Fehliug's  solution.  It  is  hydrolyzed  by  boiling  with  dilute 
acids,  yielding  only  d-glucose.  It  is  fermentable.  Its  osazone  fuses 
as  206°.     Nitric  acid  oxidizes  it  to  d- saccharic  acid. 

Isomaltose — OalUsin — is  formed  along  with  maltose,  in  the  action 
of  diastase,  saliva,  or  pancreatic  juice,  or  of  boiling  dilute  acids,  on 
starch,  and  exists  in  beer  and  artificial  glucose.  It  is  also  formed  by 
the  prolonged  action  of  strong  HCl  on  d-glucose.  It  is  very  soluble  in 
water,  very  sweet,  and  does  not  ferment,  or  does  so  very  slowly.  Its 
osazone  forms  yellow  needles,  which  fuse  at  150°  (302°  F.),  and  are 
rather  soluble  in  hot  water. 


TRISACCHARIDS. 

Several  members  of  this  group  have  been  obtained  from  different 
vegetables.  They  have  the  formula  C18H32O16.  The  best  known  are 
Raffinose,  or  Melitose,  which  occurs  in  eucalyptus -manna,  in  cotton 
fieeil,  aud  in  beet -sugar  molasses;  and  Melecitose,  from  the  manna 
of  Pinus  larix. 

POLYS  ACCHARIDS. 

The  starches,  gums,  and  celluloses,  which  form  this  class,  have 
the  empirical  formula  CeHioOs,  but  their  molecular  weights  are  much 
greater  than  that  represented  by  that  formula.  They  are  very  widely 
distributed  in  vegetable  nature.  On  hydrolysis  they  are  finally  de- 
composed to  monosaccharids,  for  the  most  part  hexoses,  although 
some  of  the  gums  yield  pentoses. 


320 


MANUAL    OF    CHEMISTRY 


Starch — Amylum^the  most  imporlaut  member  of  the  group,  ex- 
ists in  the  roots,  stems,  and  seeds  of  all  plants;  and  is  obtaiued  com- 
mercially from  rice,  potatoes,  and  maize.  It  is  a  white  powder,  eon- 
sisting  of  granules  which  are  roiiud,  ovoid  or  irregular  in  outline, 
and,  in  some  cases,  marked  with  a  central  spot  or  line,  called  the 
hilum,  and  with  concentric  rings.  Differences  in  the  shape,  size  and 
markings  of  the  granules  are  utilized  to  identify  the  vegetable  from 


Fia.  41,    A,  wb<»*t-8tftrich ;  B,  OAt-starch;   C,  make-Jitarch:  ij»,  potato  atAirh.     X  300  dlnmeten. 

which  the  starch  was  obtained.  Some  of  the  commoner  forms  are 
shown  in  Fig.  41.  Air-dried  starch  contains  18%  of  water,  of  which 
it  loses  8%  in  vaeno,  and  the  remainder  only  at  145^  (293°  P.). 
Starch  is  insohible  in  cold  water  and  in  alcohot*  If  15  to  20  parts 
of  Hi»0  be  gradually  heated  with  one  part  of  starch,  the  granules 
swell  at  about  35^  (131''  F.),  and  at  HO"*  (176''  F.)  they  have  lost 
their  structure,  have  swelled  to  thirty  times  their  original  volume, 
and  have  formed  a  homogeneous,  translucent,  gelatinous  mass*  com- 
monly known  as  starch  paste.     This  hydrated  starch  consists  of  an 


ALDEHYDE  ALCOHOLS  —  KETONE -ALCOHOLS.  ETC 


321 


^^^BuBOluble  portion,  starch  cellulose,  and  a  soluble  portioD,  granufosci 
^^^nOr  soluble  starch.  Graoulose  forms  an  opalescent  solutioti  in  water, 
^^^frora  wbich  it  is  precipitated  as  a  white  powder  by  alcohol.  Its  soiii- 
H  tioQs  are  strongly  dexto^yrous,  [flE]D^+207'^  (aboot).  By  prolonged 
H  boiling  with  water,  or,  more  rapidly,  by  boiling  dilute  mineral  acids, 
■^  or  by  the  action  of  di astatic  eozj^mes,  soluble  starch  is  converted  into 
^^K^extrins,  maltose,  and  finally,  d- glucose.  Dry  heat  causes  the  starch 
^^V grannies  to  burst,  with  fonnation  of  dextrin.     A  dilute  solution  of 

■  iodin  produces  a  violet-blue  color  with  starch,  whether  dry,  bydrated, 

■  or  in  solution.  The  color  is  discharged  by  heat,  but  reappears  on 
H  cooling.  Concentrated  IIXO3  dissolves  starch  in  the  cold,  forming  a 
H  nitro- product,  called  xylodin,  or  pyroxam,  which  is  insoluble  in  water, 
H      8oluble  in  a  mixture  of  alcohol  and  ether,  and  explosive. 

H  Glycogen — Animal    Starch — occurs   in    the   liver,   the  placenta, 

H  white  blood  corpuscles,  pns  cells,  young  cartilage  cells,  mnscular 
H  tissue  and  many  embryonic  tissnes,  also  in  many  molluscs.  It  is 
H  best  obtained  fi*oni  liver  tissne,  by  extraction  with  hot  water  and 
H  precipitation  by  alcohol,  after  separation  of  protein  bodies  by  potas- 
H  sium  iodhydrargyrate  and  acetic  acid.  It  is  a  snow* white,  floury 
H  powder,  amorphous,  tasteless,  and  odorless;  soluble  in  water,  forming 
H  an  opalescent  solntion,  insoluble  in  alcohol  or  ether.  Its  solutions 
H  are  strongly  dextrogyrous^  Md=  +  196.6'^.  Glycogen  is  converted 
H  into  dextrins,  maltose,  and,  nltimately,  d-glucose  by  the  action  of 
H  boiling  dilute  acids,  and  by  the  salivary,  pancreatic  and  hepatic  dias- 
H  tatic  enzyrnes.  Glycogen  is  colored  wine -red  by  iodin,  the  color  being 
H  discharged  by  heat  and  returning  on  cooling.  Its  solutions  dissolve, 
H       but  do  not  reduce  cupric  liydroxid. 

H  Other  starches  are:  Paramylum,  occurring  in  certain  infusoria; 

H  Ltchenin,  in  lichens  and  mosses;  and  Inulin,  in  the  roots  of  dahlia, 
H      chicory  and  other  plants. 

H  Gums — are  amorphous,  translucent  substances  occnrring  in  many 

H  plants.  They  are  insoluble  in  alcohol  and  in  ether.  With  water  some 
B      of  them,  the  true  gums,  form  clear  solntions;  while  others,  the  vega- 

■  table  mucilages,  swell  np  to  sticky  masses  which  cannot  be  filtered 
through  paper.  On  boiling  with  dilute  H-2804  the  gnras  yield 
d-glucose,  galactose,  or  l-arabinose.  Nitric  acid  oxidizes  them  to 
mncte,  oxalic  and  sacebaric  acids. 

The  commoner  members  of  the  group  ai-er  Arabin,  the  chief  con- 
stttneiit  of  gum  arabic  (acacia)  and  gum  senega^  and  Bassorin,  the 
chief  ingredient  of  gum   tragacanth»  Bassora  gum,,  and   plum  and 
L      cberr>'  gnms. 

H  Dextrin — British   gum — a   snbstance   resembling   gnra   arabic   in 

W  appearance  and  in  many  properties,  is  obtained  by  one  of  tliree 
K      methods  :    (1)  by  subjecting  starch  to  a  dry  heat  of  175^  (347''  FJ; 

1        ■ 


322 


MANUAL    OF    CHEMISTRY 


(2)  by  heating  starch  with  dilute  H2SO4  to  90°  (194°  P.)  until  a  drop 
o€-the  liqaid  gives  only  a  wiue-red  eolor  with  iodin;  neutralizing  with 
ofitafe,^filter4tt*6V -concentrating,  precipitating  with  alfvohol;  (3)  by  the 
bea§ftl<WMt(ftta6t^<fttffeli^rcS:t>fef  maltKupon  h^^drated  starch.  As  soon 
fl^M  i«C#^fa.^^4lf^M^tili|^'liliylAf>ftl«9^  to  boiling 

rtiij>A^flyiy?W"«-**iii^ft^Mi^;j^^'''  ."-^ni'sij^  oiUil&alb  ^o  nojjoa  t.«,    , 

^■llMf>i4 lit ttiflt'iTi  W>>^>*J¥4ivirf*Ml^ 111 \^f /  ftslq«^kif Wn V »4^rf f*|-ittj^> jrf^g^§e*J '  1*^ 
^hihlft^g^Htfti  l«^bi^.<i^^  Myyii^^^ii^^i^  Itfe  a^IlJ^it1tt&areia^t^yt^ul9 

colored  wine'R^«<N[>4^<jfefl«  ;11;^te><^§ito4^tJ^*Hii<?di'«feJ4iWi]&smtti^^^ 
^##(^'lftteM^ri^    /i-i^vrl    Mfli    ifi    8'inf>oo — doiBiZ    lBmmA'—ri^20D\lD 

p^gL ^tf^ ] '''Mkn^ni^  ^iowilt^'%'m*^)Ji^^lOO)fii**ir^''J*t^^ 

te^tMS^xtf ii¥ 9a^'4^\*oloi%if  %^na4} •  t or* ^«^ictt*Mt5«J^  Tjte »^!^ta^3« 
llbv^rj^^^nt^Ht^  P»^tV*fJ^TA*oe'4^^M^^^flUtttef>'H2i*OV|I^Wta^^ 
*Hii|0^*;*W^cJiWg  ^i^nj^*«tmfv /C'Jiiviljift  9d1  yd  htiB  .Bbi^m  ^Inlib  gniliod 

r)()((^-2H2oOio)  :    that    thi.s    is    first^'^^nl^^i4f4(Hb<imt-1'V>f!y^         '^hi-mi 

formation  of  maltose,  of  which  tho  final  resiflt.f^fii%lkfd|^  ^^j^r^miSiM 
bj^ J^thef^^^iyi RWP**  89'jfiJi1>!drj8  3ii9onl8UB*iJ  .enoriqionui  ^la — zmuD 
nuoB  igjB'w  lUVfF    .*nd1if  m  hija  UHUi'Asi  ni  ^kfiiioenj  9*ia  vadT    *glaalq 
-fia^v  9dt  ,^f«ftB.i>fhfVrt^ft4MMn^  tt6fsf%f*fbl),iriiii3'*^'eift  ,aisdi  I0 

r  .tfv         .Soltibla  Btartsli,.  ,       Wetter.  AckxoddfJ^trlii.       ..        MnltOB«,     ..  .  . 

I'mna  od  jorfna*)  rTurfT?  k^H'iv.m  7H'>jI8  oj  qu  iUy^a  ^t^'^Bltoum  dldal 
^^''iaeltlJlOTe^fe//0»Wlil~f(^(tWnh^^^^^^  ii^eti>hl«qit^iss(i^imdl 

Mii*mv^itliSi^tjJ|i«0ir^/i%  ^l^l*i''^itli.|if<*»ld»lJnnKl*i%f.^M<?|ilpteDt3*p*ffi3hi 
purer,  unsized  papers,  in  cotton »  oB^^ii^  tlii^l*kfr^a^p«ntl*I|gr«i^Qfi'««i0i 
ttfftt>  ^ih . ^j ilVkmdni^rf^^'^^  fimn^M^nMiih^i m^^^[mmi'fi'^\iptnm]ki'ni %  i t li 
HBC^HW*l^^rfci<*tdf4nwtA^ddWP«rt>ff|t,  (^l^e'^Jui-iiJiKiMifirt^  ^►^*b«t 
^tllioAFtrilqlth^  wmt<^  Hifl^silii  sldlp#o^fiflMe  t4itsr!ft*(|ii^i&blQtoiit?^fl(9 
derived,  is  ins<jluhle  in  the  usnnl  solventt>,  but  solnlile  in  J^(^lilrkiMd# 

eriiVe|«tdMfe  "t4rAfftf§*<f^Par^^e9^"i9^alS«#wi*isfTblftfl 


ALDEHYDE* ALCOHOLS—  KETONE- ALCOHOLS,  ETC. 


32a 


Tolame  of  H2O,  wiishiog  thoroughly,  aud  drying.  It  is  a  tough  ma- 
terial resembling  animal  paiirhinent. 

Gun-cotton — Pyroxylin— is  abtained  by  dipping  pure  cotton  in  a 
cold  mixtm-e  of  one  part  of  HXO3  and  two -thirds  of  H28O4  for  from 
three  to  ten  niiniites,  washing  thoroughly,  and  drying.  It  consists 
of  hexanitroeellnlose,  Ci2Hu(0.NO2)604t  is  violently  explosive*  and  is. 
insoluble  iu  a  mixture  of  alcohol  and  ether. 

Soluble  pyroxylin^ is  obtained  by  acting  on  cotton  with  a  warm 
mixture  of  twenty  parts  of  nitre  and  thirty  parts  of  concentrated 
H2SO4,  washing  and  drying.  It  consists  of  penta-  and  tetra-nitro- 
cellulose,  is  soluble  in  a  mixture  of  alcohol  and  ether,  and  is  used  in 
the  preparation  of  collodion.  Explosive  gelatin,  or  smokeless  pow- 
der, is  a  desiccated  mixture  of  nitro- glycerol  and  collndinn.  Celluloid 
is  a  mixture  of  guu-i*»>it<>n  and  cauipiior,  combined  by  pressure. 

Tests  for  Carbohydrates, — A.  Fnf^fttrole  Reacfions — dependent 
upon  the  lorruatiou  of  furfurole  by  the  dehydrating  action  of  concen- 
trated H'iSOi  upon  carboliydrates  (p.  509). 

Molhch's  Reaction. — To  1  cc»  of  the  solution  add  two  drops  of  a 
15  per  cent  alcoholic  solution  of  ^ — naphthol,  and  float  the  mixture 
a^utB^ucentrated  H-jHOi*  A  deep  violet  hand  forms  at  the  junction  of 
fhll*II[fW^s?*^^'iiiiHtitMi  of  water  produces  a  bluish  violet  ppt,,  soluble 
^?\i\n,\m*^'^i^(^'tm3'Wn\Xum  with  a  yellow  color.  Thymol  may  be 
ftsM^b^ii*^  iV'^J^'fatriAlMl.-Wtft  fife  color  is  then  carmine'red.  Invw 
lftg^ii¥i*>nLiPaitHhKii.  MmimilmAim  oJ  toiv 

^A^V^WWA\h9\^^\^Mk^^l^^  'riulxim  ytil  bun  .boxim  mn  srioiloloa 
iite^  do  not  r.act  with  the  for^Fj^li^^P'lVffll^Yli^^li^rt^  ^^  '^^I^ 


324 


MANUAL    OF    CHEMISTRY 


chlorid  forms  insoluble  white  ppts.  of  beuzoyl  esters  in  solutions  of 
carbohydrates  containing  eausHc  soda.  »Siinilar  insoluble  benzoyl 
derivatives  are  formed  by  polyatomic  alcohols  and  by  diamins  (p.  298), 

C.  Aldehyde  and  Ketone  Reactions, — These  reactions  depend  upon 
the  presence  in  the  carbohydrates  of  the  CHO  or  CO  group,  and  are 
eonsequently  given  by  cane-sugar,  noo-reducing  dextrins  and  starch, 
which  do  not  contain  such  groups,  only  after  their  hydrolysis  by 
boiling  with  dilute  acids;  but  are  given  by  other  substances  contain- 
ing ketone  or  aldehyde  groups. 

1.  Copper  Rednction  Tests. — These  and  other  reduction  tests  are 
produced  not  only  by  aldoses  and  ketoses,  but  also  by  other  reducing 
agents.  Therefore,  such  substances,  as  well  as  albumin,  must  be 
excluded  before  these  tests  are  resorted  to.  This  may  be  accomplished 
by  Pocke's  method,  by  boiling  10  cc.  of  the  liquid  (urine)  with  5  ce.  of 
CuSO*  solution  (1:10),  filtering,  adding  2  cc,  Na^CO^  solution  (1:10) 
to  the  cool  filtrate,  and  filtering  again  after  standing. 

Trommer's  Reaction  is  the  earliest  form  of  reduction  test  for  sugar. 
It  consists  in  adding  about  one-eighth  of  NaHO  or  KHO  solution 
(1:10)  to  the  dilute  saccharine  liquid,  then  two  to  three  drops  of 
OuS04  solution  (1:10)  and  heating  the  blue  liquid  just  to  boiling.  A 
yellow  ppt.  is  formed,  which  becomes  darker  and  reddish  on  boiling. 

Fehling-s  Test. — The  reagent  must  be  kept  in  two  solutions,  which 
are  to  be  mixed  immediately  before  use.  If  the  reagent  be  made  in  a 
single  solution  it  is  prone  to  self-reduction.  Solution  I  consists  of 
34,653  gms.  of  crystallized  CUSO4,  dissolved  in  water  to  500  cc;  and 
11^  of  130  gms.  of  Rochelle  salt  dissolved  to  500  ec.  in  NaHO  solution 
of  sp,  gr,  1.12.  When  required  for  use  equal  volumes  of  the  two 
solutions  are  mixed,  and  the  mixture  diluted  with  four  volumes  of 
water.  A  few  cc.  of  this  liquid  are  heated  to  boiling,  and  the  saccha- 
rine liquid  (urine)  added  in  small  portions,  the  contents  of  the  test- 
tube  being  heated  short  of  boiling,  but  not  boiled,  after  each  addition. 
A  reducing  sugar  produces  a  yellow  or  red  ppt.,  which  forms  more  or 
less  rapidly  according  to  the  amount  of  sugar  present.  The  liquid 
should  not  be  boiled  after  addition  of  urine,  as  creatinin  and  uric  acid 
may  reduce  by  boiling,  Qlucuronates  and  glycosurates  also  reduce. 
There  are  many  modifications  of  this  test^  in  which  potassium  tartrate, 
mannite,  glycerol,  etc.,  are  used  in  place  of  Rochelle  salt,  but  they 
present  no  advantages  over  the  above.  Favtfs  solutiofi  is  a  modified 
Fehling,  containing  a  notable  n mount  of  ammonia.  It  has  the  advan- 
tage for  quantitative  work  (p,  751)  that  the  blue  color  is  more  sharply  j 
disf'harged  on  total  reduction,  but  it  is  open  to  the  objection  that  the 
ppt.  is  soluble  in  the  ammoniacal  liquid. 

Barfoed^s  Rfaetion  is  a  modified  Fehling;  the  reagent  being  a  solu- 
tion of  0.5  gm,  of  eupric  acetate  and  1  cc.  of  acetic  acid  in  100  cc.  of 


ALDEHYDE- ALCOHOLS  -  KETONE- ALCOHOLS,    ETC. 


325 


I 


» 


I 


water.  It  is  reduced  by  glucose  in  the  cold  aod  more  rapidly  ou 
heating.  It  is  not  reduced  by  dextrine,  saccharose  or  lactose,  and 
serves  to  distinguish  the  last  named  sugar  from  glucose, 

2.  Bi^'imufh  Rfduciion  Tes(s,~Bo€t(ger^ s  tei^t  may  be  applied  either 
in  the  manner  originally  indicated,  or  in  Nifhinder^s  or  Almht's  modi- 
fications. Equal  portions  of  the  liquid  are  placed  in  two  test  tubes, 
to  each  of  which  enough  solution  of  Na2C0a  is  added  to  make  the 
reaction  distinctly  alkaline,  and  to  one  a  little  powdered  bismuth  sub- 
nitrate,  and  to  the  other  a  little  powdered  litharge  are  added.  The 
contents  of  the  two  tubes  are  then  heated  to  boiling,  when,  if  the 
bismuth  powder  becomes  black  and  the  litharge  remains  unchanged, 
the  presence  of  a  reducing  sugar  raaj^be  inferred.  The  purpose  of  the 
litharge  is  to  guaM  against  error  from  the  presence  of  sulfur  com- 
pounds, which  blacken  both  the  bismuth  and  lead  powders.  Niflamhr's 
salution  is  made  by  adding  4  gms.  of  Rochelle  salt,  2  gms.  of  bismuth 
subnitrate  and  10  gms.  of  caustic  soda  to  90  cc.  of  water,  boiling, 
cooling  and  filtering.  To  use  the  test  1  cc.  of  the  reagent  is  added  to 
the  liquid  and  the  mixture  boiled,  when  a  reducing  sufjar  caufcies  the 
formation  of  a  gray  or  black  ppt.  A  parallel  testing  with  litharge  is 
alfio  required.  An  affirmative  result  is  obtained  with  urine  in  the 
absence  of  sugar  when  large  doses  of  qninin  have  been  taken,  but  uric 
aeid  and  creatinin  do  not  react,  and  therefore  this  reaction  is  prefer- 
able to  the  copper  reduction  tests,  although  glucuronates  react  with  it. 

3.  Reduction  of  Other  Metallk  Compounds. — Many  other  tests  for 
aldoses  and  ketoses  have  been  used,  based  upon  the  reduction  of  metal- 
lic salts  other  than  those  of  copper  and  bismuth:  auric  chlorid,  nickel 
sulfate,  mercuric  salts,  molybdates,  ferric  salts,  iodic  acid,  silver  ni- 
trate, lead  salts  and  potassium  dichroniate*    Of  these  the  only  one 
iwesenting  any  advantage  over  the  copper  and  bismuth  tests  is  Knapp^s 
iDercaric  cyanid  reaction,  which  gives  a  sharper  end  reaction,  and  is 
therefore  preferable  to  the  Fehling  for  quantitative  determinations, 

4.  Reduction  of  Organic  Compounds. — The  Mulder  -  Neuhaner  test, 
hosed  upon  the  reduction  of  indigo -blue;  that  of  Vogel,  in  which  lit- 
'^Qs  is  substituted  for  indigo;  the  A^eumann-  ^Vender  reaction,  based 
^'Pon  the  decolorization  of  methylene  blue,  and  the  reactions  of 
'^*'^^r,  Quirini  and  Hoppe-Seyhr,  based  upon  the  reduction  of 
^^honitropropiolie  acid  to  indigo  are  not  preferable  to  the  copper  or 
hutnuth  reduction  tests. 

5.  OsaMone  Reaction, — The  phenylhydrazin  test,  or  Fischer^ s,  or 
^^^9kr*8  test  depends  upon  the  formation  of  osazones  by  all  monosac- 
'-'lariilsanddisaccbarids  containing  CO  or  CHO  groups  (p,  485).  To 
^f^cc,  of  the  liquid  (urine)  in  a  test  tube,  add  0,5  gra.  phenylhy- 
^fszin  hydrochlorid  and  1  gm.  sodium  acetate,  and  cause  the  powders 
*o  dissolve  by  warming,  and,  if  necessary,  the  addition  of  water,  and 


326  MANUAL    OF    CHEMISTRY 

leave  the  test  tube  in  a  boiling- water  bath  for  one  hour,  after  which 
cool  it  by  immersion  in  cold  water.  If  a  ketose  or  aldose,  whether 
hexose  or  pentose,  or  a  glucuronate  be  present  a  yellow  ppt.  is  formed, 
usually  crystalline,  which  should  be  collected  and  examined  microscop- 
ically. Needle-shaped  crystals  are  formed  by  glucose,  fructose,  maltose 
and  glucuronic  acid.  The  osazones  of  glucose  and  fructose  are  one 
and  the  same  substance.  The  several  osazones  have  different  fusing 
points:  that  of  glucuronic  acid,  114°-115°;  of  isomaltose,  150°-153°; 
of  arabinose,  159°;  of  galactose,  193°;  of  glucose  and  fructose,  204°- 
205°,  and  of  maltose,  206°.  To  determine  the  fusing  point  the  ppt. 
is  collected,  dissolved  in  hot  alcohol,  the  solution  filtered  and  evapo- 
rated, the  crystals  dried  over  H2SO4,  placed  in  a  small  closed  tube 
attached  to  the  bulb  of  a  thermometer  by  a  pasted  slip  of  paper,  and 
heated  in  a  paraffin  bath,  the  temperature  being  noted  when  the  mate- 
rial fuses.   Aldehydes  and  ketones  also  form  hydrazones. 

6.  VillierS'Fayolle  Reaction. — This  reaction  and  the  following 
permit  of  the  distinction  between  monaldoses  and  monoketoses.  A 
solution  of  fucbsin  which  has  been  decolorized  by  sulfur  dioxid 
(Schiff's  reagent)  is  immediately  turned  red  by  aldehydes  and  by  mon- 
aldoses, such  as  glucose  (and  invert  sugar),  and  galactose,  but  not  by 
ketones  or  monoketoses,  such  as  fructose  and  sorbinose.  The  disac- 
charids,  saccharose,  maltose  and  lactose  produce  no  color  at  first,  but 
after  a  few  days  they  become  hydrolysed  and  the  color  appears, 
increasing  in  intensity. 

7.  SeliwanojSTs  Reaction,  or  ConradVs  reaction,  is  given  by  keto- 
hexoses,  such  as  fructose  and  sorbinose,  and  by  those  disaccharids 
which  yielji  ketoses  on  hydrolysis,  as  cane-sugar  (and  invert  sugar), 
raffinose  and  inulin.  The  reaction  consists  in  the  formation  of  a  red 
pigment,  which  is  precipitated,  and  is  soluble  in  alcohol  with  a  red 
color,  when  the  liquid  is  boiled  with  resorcinol  and  HCl. 

8.  Berg^s  Reaction, — Aldoses  are  oxidized  by  bromin  to  form  acids 
which  give  an  intense  yellow  coloration  with  very  dilute  and  slightlj- 
acid  Fe2Cl6  solution,  but  ketoses  do  not.  From  0.2  to  0.3  gm.  of  the 
sugar,  solid  or  in  concentrated  solution,  is  heated  10  minutes  to  60°- 
70°  with  10  cc.  of  freshly  prepared  saturated  bromin  water,  and  then 
rapidly  heated  to  the  boiling  point  to  expel  excess  of  bromin.  The 
colorless  solution  is  tested  with  10  cc.  of  a  reagent  made  by  adding 
to  100  cc.  of  water  four  drops  of  FeoCle  solution,  sp.  gr.  1.45,  and 
two  drops  of  HCl,  sp.  gr.  1.17.  Sugars  containing  no  CHO  give  little 
or  no  color.    Arabinose,  glucose  and  galactose  give  strong  reactions. 

9.  Fermentation  Test. —  Brewers*  yeast  and  compressed  yeast, 
which  consist  principally  of  Sacchnromyces  cerevisice,  cause  alcoholic 
fermentation  of  the  d-hexoses  easily,  but  do  not  ferment  the  1-hex- 
oses  or  pentoses.    And,  as  this  yeast  secretes  invertin  and  maltase,  it 


j 


CARBOXYLIC    ACIDS  327 

also  causes  alcoholic  fermentation  of  saccharose  and  maltose  immedi- 
ately, and  of  lactose  very  slowly.  The  polyoses  and  glncosids  only 
ferment  after  hydrolysis  by  boiling  ¥rith  dilute  acids.  Pure  cultures 
of  8.  apiculaius  and  8.  membrancefaciens  secrete  no  invertin  or  mal- 
tase,  and  therefore  do  not  ferment  saccharose  or  maltose.  For  quali- 
tative testing  the  evolution  of  gas  under  the  influence  of  yeast  is  taken 
as  evidence  that  fermentation  has  occurred.  Three  Smith's  fermenta- 
tion tubes  are  used,  each  containing  a  little  compressed  yeast,  one 
filled  with  the  liquid  to  be  tested,  the  second  with  pure  water,  and  the 
third  with  a  dilute  solution  of  glucose,  and  the  three  are  put  in  a 
warm  place  over  night.  If  gas  collects  in  the  first  and  third  tubes,  but 
not  in  the  second,  the  liquid  contains  sugar;  if  gas  collects  in  the  third 
only  it  does  not;  under  any  other  circumstances  the  yeast  is  at  fault. 
For  methods  of  quantitative  determination  of  glucose,  see  p.  750. 

CARBOXYLIC  ACIDS. 

These  compounds  are  the  fourth  products  of  oxidation  of  the 
paraffins  (p.  283).  and  contain  the  characterizing  group  of  atoms 
OrC.OH  (carboxyl).  They  are  either  pure  acids,  containing  only 
the  carboxyl  and  hydrocarbon  groups;  or  alcohol -acids,  containing 
also  the  groups  CH2OH,  CHOH  or  COH;  or  aldehyde-acids,  contain- 
ing GHO;  or  ketone -acids,  containing  CO;  or  of  still  more  complex 
function,  containing  two  or  more  of  the  above  groups. 

The  most  important  of  the  pure  acids  are  those  of  the  acetic 
(C»H2h02),  and  oxalic  (C«H2ii-204)  series,  the  former  of  which  are 
monobasic,  the  latter  dibasic.  Other  pure  acids  of  higher  basicity  are 
also  known  in  which  the  carboxyl  groups  are  substituted  ^or  hydro- 
gen atoms  in  the  hydrocarbon.  The  following  are  examples  of  such 
acids: 


CH2.COOH 

1 

CH:(C00H)2 

CH:(COOH)a 

CH.COOH 
1 

1 
CH:(C00H)2 

CH.COOH 

1 

CHj.COOH 

CH:(COOH)j 

TrieftrballyUc 

Dimalonio 

Propenjrl-pentaearbozylle 

add. 

Mid. 

Mid. 

PARAFFIN  MONOCABBOXYLIC  ACIDS — VOLATILE  FATTY  ACIDS  —  ACETIC 
SERIES — SERIES    CifH2M02 

The  lowest  terms  of  the  series  are  volatile  liquids,  the  highest  are 
solids  and  exist  in  their  glycerol  esters  in  the  fats;  hence  the  name  of 
volatile  fatty  acids.  The  solid  acids,  the  tenth  and  higher  of  the 
series,  cannot  be  distilled  without  decomposition  except  in  superheated 
steam. 


328 


MANUAL    OF    CHEMISTRY 


As  the  liydrocarboQs^  may  be  eoosidered  as  the  hydrids  of  the 
alkyls  (p,  274),  aud  the  akohols  as  their  hydroxids  (p.  284),  so  the 
acids  may  be  considered  as  the  hydroxids  of  the  acidyls :  the  acid  or 
oxidized  radicals.    Thus  acetic  acid  is  acetyl  hydroxid,  {CH,).CO)OH. 

These  acids  may  be  obtained: 

(1)  By  oxidation  of  the  corresponding  alcohol  or  aldehyde:  C2H5.- 
CH20H+02=C2H5.COOH+naO,  or  2CH:,.CHO+02--2CH..COOH; 

(2)  By  decomposition  of  the  dicarboxylic  acids  (p.  334),  with  elimi- 
nation of  carbon  dioxid:  C0On,COOH=H,CO0H+CO2,  and  COOH.- 
CIi2.COOH=CIl3.COOH+C02i  (3)  By  the  action  of  carbon  mon- 
oxid  upon  an  alkaline  hydroxid  or  alcoholate :  CO  +  NaHO  = 
ILCOONa,  aud  CO+C2H5X>.Na=C2Hr,.COONa;  (4)  From  the  nitrils, 
or  hydrocyanic  esters  (p,  393),  by  the  action  of  acids  or  alkalies  in 
the  presence  of  water:  HCN  +  H2O  +  KHO  =  H.COOK  +  NH3,  or 
CH:,.CX+2n20+HCI^CH3.COOH+NH4Cl.  Tbis  eoustitutes  a  gen- 
eral method  for  the  introduction  of  carboxyl,  starting  from  the  haloid 
derivatives  of  the  hydrocarbon  (p.  277).  This  is  converted  into  the 
cj-anid,  or  nitril  {p.  393)  by  heating  with  aleoholie  potassium  cyanid: 
BrCH2.CH3+KCN=CNCH2.Cn,+  KBr,  or  BrCH2.CH2Br+2KCN= 
CX.CH2.CH2.CN4-2KBr;  aud  the  cyanid  is  then  converted  into  the 
acid  by  elimination  of  the  nitrogen  as  ammonia,  and  the  substitution 
of  OOH  in  its  place  by  the  action  of  aeids  or  of  alkalies:  CN.CH2.- 
t^H:i-hHCl+2n20=c6on.CH2.CH3+NH.iCl,  or  CK.CH2,CH2.CN+ 
2KHO+2H20=COOK,CH2,CH2.COOK+2NH:,  (pp,  335,  337,  428). 

These  acids  form  esters  (p.  358)  with  aluobols,  in  the  presence  of 
HCl  or  H28O4,  to  absorb  the  water  formed:  CH^t.COOH+CHa.CHs- 
OH==CH:i,CO0(C2H5)+H2O.  With  halogens  they  form  halid  acids 
{p.  330):  CHa,COOH+Cl2^CH2CLCOOH+HCL  With  phosphorus 
halids  they  form  aeidyl  halids  or  anhydrlds  (p.  351):  CH3.COOH  + 
PCls=CH3.0O.Cl+p6cb-fHCl,  aud  2bH;5.COOH+PCl5"  (CH3CO)2- 
0+POCl3^-2HCl.  Their  ammonium  salts,  when  heated,  split  off 
water  to  form  amids  (p.  400)  and  nitrils  (p.  393):  CHs.COOCXHi) 
=CH:^C0.NH^+H'20  and  CH..COO(NH4)^CH3.CN+2H20, 

Formic  Acid— H.COOH.— Although  it  is  the  first  term  of  this 
series,  formic  acid  differs  from  its  superior  liomologues  in  several 
respects:    (1)   It  is  not  a  pure  acid,  but  an  aldehyde -acid,  the  single 

carbon  atom  forming  part  of  both  groups:'  0:C<^u  ;  (2)  The  halo* 
gens  do  not  convert  it  into  halid*formic  (or  carbonic)  acids,  but  split 
it  to  carbon  dioxid  and  the  hydracid:   H.COOH+Ci2==CO.+2HCl; 

(3)  By  elimination  of  water  it  yields  carbon  monoxid:  H.COOH^= 
CO+H2O;  (4)  It  produces  no  aeidyl  halid  oranhydrid  corresponding 
to  those  of  its  superior  honiologues* 

It  occurs  in  the  btniies  of  ants  and  of  other  insects,  and  in  the 


CABBOXYLTC    ACTDS 


329 


blood,  bile»  perspiration  aod  muscular  fluid  of  mammalia.  It  is  pro- 
duced b.v  oxidation  of  sugar,  starch,  gelatin,  albumin,  etc;  in  the 
fermentation  of  diabetic  urine;  by  the  action  of  potash  upon  chloro- 
form: CHCl3+4KHO=H,COOK+3KCl+2H20;  by  the  action  of 
hydrating  agents  upon  its  uitril,  hydrocyanic  acid  (p.  391):  HCN+ 
2H20=H,COO(NH4)i  and  by  decomposition  of  oxalic  acid  in  the 
presence  of  glycerol  at  about  100^  COOH.COOH^H.COOH+COit. 

It  is  a  colorless  liquid  of  acid  taste  and  penetrating  odor,  b.  p.  100°, 
crystallizes  at  0°,  miscible  with  water.  It  is  decomposed  by  mineral 
acids  to  carbon  monoxid  and  water:  H.COOH^^CO+H^O;  by  oxi- 
dizing agents  to  carbon  dioxid  and  water:  2H.COOH+02^2H20+ 
2CO2;  and  by  caustic  alkalies  to  a  carbonate  and  hydrogen :  H,COOH 
-f  KHO=KHC03+H2.    It  reduces  the  salts  of  Au,  Ag,  and  Hg. 

Acetic  Acid — Acefffl  Hydrojcid — Avidum  areiicum  (U,  S.^Br.)^ — 
CH3-COOH — is  formed  by  the  general  methods,  and  (1)  by  the  action 
of  carbon  dioxid  on  sodium  methyl:  COs+NaCHjr^CHs.COONa;  and 
(2)  by  the  oxidation  of  many  organic  substances:  start*h,  sugar, 
gelatin,  fibrin,  cellulose,  tartaric  and  citric  acids,  etc.  CommerciaUy 
it  is  obtained  as  acetic  acid  and  as  vinegar.  As  the  former  it  is 
produced  by  the  dry  distillation  of  wood,  in  which  four  products  are 
obtained:  charcoal,  remaining  in  the  retort,  an  illnminating  gas,  a 
tarry  liquid,  wood-tar,  and  an  acid  liquid,  "crude  wood  vinegar"  or 
"pyroxylic  spirit."  The  last  is  a  highly  complex  liquid,  containing 
acids  of  this  series,  methyl  acetate,  and  cyclic  compounds.  It  is  redis- 
tilled fractionally,  the  first  portions  being  used  as  a  source  of  methylic 
alcohol  (p,  286),  and  the  later  portions  of  acetic  acid.  In  these  the 
acid  is  cou verted  into  sodium  acetate,  which,  after  calcination,  is 
decomposed  by  H2SO4,  and  the  liberated  acetic  acid  distilled  off.  The 
product  so  obtained,  the  commercial  acid,  contains  36  per  cent  of 
true  acetic  acid,  sp.  gr.  1.047. 

Vinegar  is  obtained  by  the  indirect  atmospheric  oxidation  of 
various  alcoholic  liquids,  containing  less  than  10  per  cent  of  ethyl 
alcohol,  under  the  influence  of  the  gniwth  of  a  true  ferment,  Bueierium 
acefi^  or  "mother  of  vinegar,"  with  free  access  of  air.  It  contains 
from  5  to  10  per  cent  of  acetic  acid. 

Pure  acetic  acid,  called  glacial  acetic  acid,  is  obtained  by  dis- 
tilling dry  sodium  acetate  with  a  slight  excess  of  H2SO4.  It  is  a  color- 
less liquid,  b.  p.  119°,  crystallizes  to  an  ice -like  mass  at  17°,  sp.  gr. 
1*0497  at  20°,  having  an  acid  taste  and  tlie  odor  of  vinegar,  and 
causing  vesication  when  applied  to  the  skin.  Glacial  acetic  acid  on 
dilution  with  water  contracts  until  the  sp.  gi\  becomes  1.0754  with  a 
dilation  of  77  per  cent  of  acid^  corresponding  to  a  hydrate:  CII;!.- 
COOH+H2O,  and  on  further  dilution  the  sp.  gr.  diminislies  until  at 
50  per  cent  it  is  the  same  as  that  of  the  glacial  acid.    Acetic  neid  is  a 


330  MANUAL    OP    CHEmSTBY 

good  solvent  for  many  organic  substances,  and  is  itself  soluble  in 
water  and  in  alcohol  in  all  proportions. 

Vapor  of  acetic  acid  burns  with  a  pale -blue  flame  and  is  decom- 
posed at  a  red  heat.  Glacial  acetic  acid  only  decomposes  calcium  car- 
bonate in  the  presence  of  water.  Hot  H2SO4  blackens  and  decomposes 
it,  SO2  and  CO2  being  given  off.  Solutions  of  potassium  acetate,  when 
electrolyzed,  yield  ethane,  C2H6.  Under  ordinary  circumstances  chlorin 
acts  upon  acetic  acid  slowly,  more  actively  under  the  influence  of 
sunlight,  to  form  the  three  products  of  substitution  mentioned  below. 

Acetates  are  soluble  in  water,  except  basic  ferric  acetate.  Potas- 
sium acetate,  heated  with  arsenic  trioxid,  forms  cacodyl  oxid  (p.  422). 
Calcium  acetate,  when  heated  alone,  yields  acetone  (p.  307);  and 
with  calcium  formate,  aldehyde  (p.  300). 

Monochloracetic  acid  is  a  solid,  f.  p.  62°,  b.  p.  186°,  obtained, 
along  with  acetyl  ehlorid,  by  the  action  of  chlorin  upon  acetic  anhy- 
drid:  (CH3.CO)20+Cl2=CH2Cl.COOH+CH3.COCl.  Dichloracctic 
acid  is  a  colorless  liquid,  b.  p.  190°,  obtained  by  heating  chloral  with 
aqueous  potassium  cyanid:  CCl3.CHO+H20+KCN=CHCl2.COOH+ 
KCl+HCN.  Trichloracetic  acid  is  an  odorless,  strongly  vesicant, 
crystalline  solid,  f.  p.  46°,  b.  p.  195°,  obtained  by  oxidation  of  chloral 
hydrate  by  nitric  acid:  2CCI3.CH  (OH)2+02=2CCl8.COOH+2H20. 
These  three  acids  are  extremely  useful  synthetic  agents  because  of 
the  facility  with  which  the  halogen  is  replaced  by  O,  OH,  NH2,  etc. 
Thus  by  hydrolysis  monochloracetic  acid  yields  glycoUic  acid: 
CH2Cl.COOH+H20=CH20H.COOH+HCl;  dichloracetic  acid  yields 
glyoxylic  acid:  CHCl2.COOH+H20=CHO.COOH+2HCl;  and  tri- 
chloracetic acid  yields  oxalic  acid:  CCl3.COOH+2H20=COOH.- 
C00H+3HC1.  With  ammonia  monochloracetic  acid  yields  amido- 
acetic  acid:    CH2Cl.COOH+NH3=CH2NH2.COOH. 

Mono-,  di-  and  tribromo-,  and  iodoacetic  acids  are  also  known. 

Superior  Homologues  of  Acetic  Acid. — Considering  acetic  acid 
as  the  first  term  of  this  series,  by  reason  of  the  peculiarities  of  formic 
acid  above  referred  to,  the  superior  homologues  may  be  considered 
as  alkyl- acetic  acids,  which  may  be  monoalkylic,  as  propionic,  or 
raethylacetic  acid:  CH3.CH2.COOH,  dialkylic,  as  isobutyric,  or  di- 
methylacetic  acid:  (CH3)2:CH.COOH,  or  trialkylic,  as  pivalic,  or 
trimethylacetic  acid:    (CH3)3  :  C.COOH. 

Propionic  Acid — Methylacetic  acid — CH3.CH2.COOH — is  formed 
by  the  action  of  caustic  potash  upon  sugar,  starch  and  gum;  during 
acetic  fermentation;  in  the  distillation  of  wood;  during  the  putre- 
faction of  peas,  beans,  etc.;  by  the  oxidation  of  normal  propylic 
alcohol,  etc.  It  is  best  prepared  by  heating  ethyl  cyanid  with  potash 
until  the  odor  of  the  ester  has  disappeared ;  the  acid  is  then  liberated 
from  its  potassium  compound  by  H2SO4  and  purified. 


CARBOXYLIC    ACIDS  331 

It  is  a  colorless  liquid,  sp.  gr.  0.996,  b.  p.  140°,  solidifies  at 
— ^36.5°,  odor  and  taste  like  those  of  acetic  acid,  mixes  with  water 
and  alcohol.   Its  salts  are  crystalline  and  soluble. 

While  there  exists  only  one  of  each  monohalogen  substitution 
product  of  acetic  acid,  there  exist  a  greater  number  with  the  higher 
homologues,  which  differ  with  the  position  of  the  introduced  halogen 
atom.  Thus  with  propionic  acid  two  are  known :  CH3.CHCI.COOH, 
alpha monochloropropionicacid) and  CH2CI.CH2.COOH,  betamono- 
chloropropionic  acid  (p.  340).  These  acids  are  best  obtained  by  the 
action  of  the  hydracids  upon  lactic  and  hydracrylic  acids  respectively 
(pp,  341,  342) :  CH3.CHOH.COOH+HBr=CH3.CHBr.COOH+H20, 
and  CH20H.CH2.COOH+HCl=CH2Cl.CH2.COOH+H20.  Because  of 
the  reducing  power  of  HI  (p.  99)  ^  iodopropionic  acid  may  also  be 
obtained  from  glyceric  acid  (p.  342):  CH20H.CHOH.COOH+3HI= 
CHaI.CH2.COOH+2H20+l2.  The  P  acids  are  also  obtained  by  the 
action  of  hydracids  upon  the  unsaturated  acrylic  acid:  CH2:  CH.COOH 
+HI=CH2l.CH2.COOH.  By  the  action  of  bromin  upon  propionic 
acid  a  monobromopropiQnic  acid  is  formed,  if  the  Br  be  not  in 
excess,  when  the  oa  dibromopropionic  acid,  CH3.CBr2.COOH  is 
formed.  Lactic  and  hydracrylic  acids  are  formed  from  the  monohalid 
propionic  acids  by  reactions  the  i-everse  of  those  given  above.  The 
P  bromo-  and  iodo  acids  form  adipic  acid  with  finely  divided  silver: 
2CH2Br.CH2.COOH+Ag2=COOH.  (CH2)4.COOH+2AgBr.  With  am- 
monia they  form  amido  propionic  acid:  CH2Br.CH2.COOH+NH8= 
CH2NH2.CH2.COOH+HBr.  Dihalid  acids,  oa,  )3)3,  and  a)3,  with  like 
or  unlike  halogens,  are  also  known. 

Butyric  Acid— Ethylacctic  Acid— CH3.CH2.CH2.COOH— exists 
in  milk,  perspiration,  muscle,  spleen,  contents  of  stomach  and  large 
intestine,  faeces,  and  guano;  in  butter,  particularly  when  rancid;  in 
certain  fruits  and  in  yeast.  It  is  formed  in  the  decomposition  of 
many  animal  and  vegetable  substances,  and  particularly  by  butyric 
fermentation  of  carbohydrates  in  presence  of  proteins.  This  fermenta- 
tion occurs  in  two  stages:  First  lactic  acid  is  produced  from  the 
carbohydrates:  C6Hi206=2C3H603,  and  this  is  decomposed  according 

to:    2C3H603=C4H802+2C02+2H2. 

Butyric  acid  is  a  colorless,  mobile  liquid,  having  a  disagreeable, 
persistent  odor  of  rancid  butter,  and  a  sharp,  acid  taste;  soluble  in 
water,  alcohol,  ether,  and  methyl  alcohol;  boils  at  164°  (327.2°  P.), 
distilling  unchanged;  solidifies  in  a  mixture  of  solid  carbon  dioxid  and 
ether;  sp.  gr.  0.974  at  15°  (59°  F.) ;  a  good  solvent  of  fats.  It  is  not 
acted  oxx  by  cold  H2SO4  or  HNO3.  Hot  HNO3  oxidizes  it  to  succinic 
acid:  2CH3.CH2.CH2.COOH+302=?COOB[.CH2.CH2.COOH+2H20. 
Dry  CI  in  sunlight,  and  Br  under  heat  and  pressure  form  several 
products  of  substitution.    The  butyrates  are  soluble  in  water. 


332 


MANUAL    OP    CHEMISTRY 


Butyric  acid  is  formed  in  the  intestine,  by  the  process  of  fermen- 
tation mentioned  above,  at  the  expense  of  those  portions  of  the 
carbohydrate  elements  of  food  which  escape  absorption,  and  is  dis- 
charged with  the  fffices  as  ammouium  bntyrate. 

Isobutyric  Acid  — Dimethylacetic  acid— <^.jj^;;CH.COOH  — boils 

at  155*^  (311°  FJ,  has  been  found  in  human  fa?ces.  It  corresponds 
to  isobutyl  alcohol,  from  which  it  is  produced  by  oxidation. 

Valerianic  Acids — CiH&.COOH — 102. — Corresponding  to  the  four 
primary  amy  lie  alcohols,  there  are  four  possible  amy  lie  or  valerianic 
acids: 

Norinal  Valerianic  Acid  —  Propyl •  acetic  acid  —  Butyl  -  formic 
acid  — is  obtained  by  the  oxidation  of  normal  amylic  alcohol.  It  is  an 
oily  liquid,  boils  at  185^  (365*^  F.),  and  has  an  odor  resembling  that 
of  hiifyrip  acid. 

Ordinary  Valerianic  Acid — ^  Isopropyl -acetic  acid  —  Deiphinic 
tft'id—  Phorf'trir  acid — Isnralerie  aeid^ I sohnttjl -formic  iirid — Acidum 
valenanicunri  (Br. ).^ — This  acid  exists  in  the  oil  of  the  porpoise,  and 
in  valerian  root  and  in  ang^elica  root.  It  is  forraed  during^  putrid 
fermentation  or  oxidation  of  proteins.  It  occurs  in  the  urine  and 
fa?ces  in  typhoid,  variola,  and  acute  atrophy  of  the  liver.  It  is  also 
formed  in  a  variety  of  chemical  reactions »  and  notably  by  the  oxida- 
tion  of  amy  lie  alcohol, 

Tlie  ordinary  valerianic  acid  is  an  oily»  colorless  liquid,  having  aa 
odor  of  old  cheese,  and  a  sharp,  acrid  taste.  It  solidifies  at  — 51^ 
(—59.8°  F,};  boils  at  173°-175°  (343.4°-347^  F,);  sp.  gv,  0.9343- 
0,9465  at  20''  (68°  FJ;  burns  with  a  white,  smoky  flame.  It  dis- 
solves in  30  parts  of  water,  and  in  alnobol  and  ether  in  all  proportions* 
It  dissolves  phosphorus,  camphor  and  certain  resins, 

Mcthyl-ethyl-acetic  Acid— boils  at  ITo""  (347°  F,),  It  contains 
an  asymiuetric  oarhon  atom  and  exists  in  two  optically  opposed  modi- 
fications (p.  311). 

Trimethyi-acetic  Acid  — P4v(tHc  acid  —  is  a  crystalline  solid* 
which  fuses  at  35,5°  (96°  FJ  and  boils  at  163.7°  (326.7°  F.);  spar- 
ingly soluble  in  H2O;  obtained  by  the  action  of  mercuric  cyanid 
upon  tertiary  butyl  iodid. 

Caproic  Acids — Eexylic  acids— CrMn.COOll  —  116. — There  exist 
seven  isoraeres  having  the  com  position  indicated  above,  some  of  which 
have  been  prepared  from  butter,  cocoa -oil  and  cheese,  and  by  decom- 
position of  amyl  cyanid,  or  by  oxidation  of  hexyl  alcohol. 

The  acid  obtained  from  butter,  in  which  it  exists  as  a  glyceric 
pst^r»  is  a  colorless,  oily  liquid,  boils  at  205°  (401°  FJ  ;  sp.  gr.  0.931 
at  15*^  (59°  Fj ;  has  an  odor  of  perspiration  and  a  sharp,  acid  taste; 
is  very  sparingly  soluble  in  water,  but  soluble  in  alcohol.  It  is  the 
normal  hexylic  acid:   CH3,(CH2)^.COOH. 


CAKBOXYLIC    ACIDS 


333 


(Enanthylic  Acid— ffepiyUc  (icifl—CoHui.COOH— 130— exists  in 
spirits  tlistiJled  from  riee  and  maize,  and  is  formed  by  the  action  of 
HNO3  on  fatty  snbstances,  espeeinlly  <*ai!>tor-oil.  It  is  a  eolorless  oil; 
sp.  gr.  0.9167;   boils  at  212''  (413.G°  F.). 

Caprylic  Acid—  CMijlic  acid  —  C7II 15 . COOH  —  144  —  accoinpan ies 
oaproic  acid  in  butler,  cocoa-oil,  etc.  It  is  a  solid;  fuses  at  15*^  (59*^ 
PJ;   boils  at  236°  {457°  F.);   almost  insoluble  in  H2O. 

Pclargonic  Acid — Noniflk  (whl — CgHi7,C00H^ — 158, — A  colorless 
oil,  solid  below  10°  (SO""  Fj  ;  boils  at  260''  (500°  F.) ;  exists  iu  oil  of 
greranium,  and  is  formed  by  the  action  of  HNO3  on  oil  of  rue. 

Capric  Acid^Becylie  Acid—{\Hrj.COOIl — 172— exists  in  butter, 
cocoa -oil,  etc.,  associated  with  caproic  and  caprylic  acids  in  their 
glyceric  esters,  j^nd  in  the  residues  of  distillation  of  Scotch  whisky,  as 
amyl  caprate.  It  is  a  white,  crystalline  solid;  melts  at  27.5*^  (81.5** 
P.);  boils  at  273°  (523,4''  P.), 

Laurie  Acid— Lanro$tearic  cicid— CnHsa.COOH — 200 — is  a  solid, 
fasible  at  43.5^  (110.3*^  F.);  obtained  from  laurel  berries,  cocoa- 
butter  and  other  vegetable  fats. 

Myristic  Acid— CiaH27.COOH— 228,— A  crystalline  solid,  fusible 
at  54^  (129.2^  Fj  ;  existing  in  many  vegetable  oils,  cow's  butter  and 
spermaceti » 

Psdmitic  Acid-- EthttUc  acid— CiiMm  COOH — 256— exists  in  palm- 
oU,  in  combination  when  the  oil  is  fresh,  and  free  when  the  oil  is  old; 
it  also  enters  into  the  composition  of  nearly  all  animal  and  vegetable 
fats.  It  is  obtained  from  the  fats,  palm-oil,  etc.,  by  saponification 
with  caustic  potash  and  subsequent  decomposition  of  the  soap  by  a 
strong  acid.  It  is  also  formed  hy  the  action  of  caustic  potash  in  fu* 
iioD  upon  eetyl  alcohol  (ethal) ,  and  by  the  action  of  the  same  reagent 
upon  oleic  acid. 

Palmitic  acid  is  a  white,  crystalline  solid;  odorless,  tasteless; 
lighter  than  H^O,  in  which  it  is  insoluble;  quite  soluble  in  alcohol 
and  iu  ether;  fuses  at  62°  (143.6°  F  J  j  distils  unchanged  with  vapor 
of  water. 

Margaric  Acid — C'kjHsii.COOH — ^270 — formerly  supposed  to  exist 
as  a  glycerid  in  all  fats,  solid  and  liquid.  What  had  been  taken  for 
inargaric  acid  was  a  mixture  of  90  per  cent,  of  palmitic  and  10  per 
cent-  of  stearic  acid.  It  is  obtained  by  the  action  of  potassium  hy- 
droxid  upon  cetyl  cyanid,  as  a  white,  crystalline  body;  fusible  at 
59.9**  (140^^  FJ, 

Stearic  Acid — CnHas.COOH  —  284  —  exists  as  a  glycerid  in  all 
solid  fats  and  in  many  oils,  and  also  free  to  a  limited  extent. 

To  obtain  it  pure  the  fat  is  saponified  with  an  alkali,  and  the  soap 
decomposed  by  IICl;  the  mixture  of  fatty  acids  is  dissolved  iu  a  large 
qnantity  of  alcohol,  and  the  boiling  solution  partly  precipitated  by 


334 


MANUAL    UF    CHEMISTBY 


the  additioa  of  concentrated  solution  of  bariam  acetate.  The  pre- 
cipitate is  collected,  washed  and  decomposed  by  HCI;  the  stearic  acid 
whiuh  separates  is  washed  and  recrystallized  from  alcohol.  The  pro- 
cess is  repeated  nntit  the  product  fuses  at  70°  (158°  FJ.  Stearic 
acid  is  formed  from  oleic  acid  (p.  429)  by  the  action  of  iodin  under 
pressure  at  270'^-280'*  (SIS'^-SSG^  F.). 

Pure  stearic  acid  is  a  colorless,  odorless,  tasteless  solid;  fusible  at 
70°  (158*^  FJ:  unctuous  to  the  touch;  insoluble  in  H^O,  very  soluble 
4n*ak*ohol  and  in  ether.  The  alkaline  steamtes  are  soluble  in  H^Oi 
those  oft?tf,'%it^%«a  W/tM>^^!*HIti'ble. 


.T^lftt^^af^  ^>lrH?l^TTftvAiri|i*^Hif^^^  in   the    intestine   during 

tWnil^ej^fti^  'Hii'Hm,  ^^^nWmir'o^^miikl  is  decomposed  bv  the 
?#t,i(*^4f  it^'^^t&fe«^^»M^e?iir^*it^ffr^A^  and    glycerol. 

%i^^aiifeT^^#irf^lid&*tetf^BlklM^  puti^fying 

proteins.  f^    ^'^-^'^    S^SSi^o... 

.bii«ric^l^«gfr-HOlpfii,V?%(^l^^^ 

rtl^^^^MV^yiti^^  a^^^'Jktewy^for^oIveM^M  W  t^lFif  Vi,  an^ 
in  small  quantity  in  butter.     It  is  n  ci^^flt^^^^Wd.?m:fr^ 

hna  t*t1iud  g'woo  »sIio  ^IdBle^QT  y.nBm  ni  sniJaixs  ;(.%  °S,e£l)  ^i-c  ^a 

iLldHieya  adMeadbi  dwl^*iMe.i6f^  4\^^M^m^^^ifiifMm9  M  ^ 
tOdUdgSdufiflpB  dliofb«nn&lill^iteit*t^i^if#<>h^^t^>  %^  ^lOiflt^*^'^  Hf^^tAt 

mrfd  iji»et]»feffereit«tete1gfiJ0^fe  J««9#i«H*iw#sfcp^.4jfe^*<yie!qMStt|»  i^6fii 

loo^ftbti&iiifle  4A(itQ(**giw^t'4lt'-(^li6M#  f^fr 

acids,  and  from  the  five  hexanes  nine  acids;  all  ot"  wlhtfl^  jft^^Rrftftfltf. 
JEhef9terffecuia»if<lbQctcb<4<>tf  f^*ite*ftl^ViediyPfle  fll'i'^riWl#  l^lSfti^Pand 
4Mii)tdncffliaoldaiio»r©iitipa^tM4i^tt^iii^  ftirrfmifo^:^^  «Oi'H  narit  lenf^gil 
•loqav  dJiw  be^giiBifouo  eVmlh  \{.1  ^^Ml)  "td  in  adeul  n^rfls  al  buB 

rUOH.CH,.CH-,.COOH  COOR\  1^1  aw   la 

iaire  o*  beaoqqng  v.hemio^— OTS-— HOOO.EeHjilTfTtl^^ 

-^tri  inui^^f^q'^%  HoilDa  ^di  rJ^H^^ftB^H^l^  Jl  .M9fl'«l'i«^<W'^4^1n^D 
ie  sldienl  r^bod  euiiiMajjtft   l^.i^  hj^o  noqu  bixrrtb 

bio  A  ohB^fZ 


I 


Mtthjl->5urcinir  neUl. 

8lai?9  —  ^8S  —  HOOO.erHr,')- 


uif.  nlJiyieus  oftBe  diKydric  alcohols  (p.  294). 


mWifiilm^%\l^ '4#4Siftf  t}«&fflRRPbT^>-ic 


CARBOXYLIC    ACIDS 


^ 


The  acids  of  this  series  may  be  obtahietl:  (1)  By  the  oxidation  of 
the  corresponding  ilipriniary  alcohols  (p.  294),  dialdehydes  (p.  306), 
primary  oxyaldehydes  (p.  308),  primary  oxyaeids  (p.  S'iS) ,  aldehyde 
aeidis  (p.  346),  parafTin  monocarboxylic  acuds  (p.  327),  olefin  mono- 
carboxylic  acids  (p.  428)  or  paraffins  (p,  282). 

(2)  By  the  reduf'tiou  of  the  olefin  diearboxylic  acids  (p,  430), 

(3)  By  the  action  of  silver  upon  the  mouoiodo  or  monobromo 
ii«j^WM8t?*2©rOH2  C(:M>H+SAi?-^2A^ 

lajiacfr?.  {tCiHn^  tinj^^s4 1  *^  f^  N  w^  1 1 1  (tiib  nje)  fl>ff  v '  fw^  ^^irid  n  ^^i  du^ 

l^pl388tTi*^fi  vHa^iofftria  8J  .bixoib  bael  dim  vib  b^tjrinlh?  si  Ji  mihIw 

^a3JBe^tei#(ft^^dltM^^>ii*flieiP3i^}4s-iA^ffa-Tiheit^^^ 

ing  to  the  attaebment  of  the  earlrf+^^li>g**MQf^.OiJl>^l^lc^iifl^a(iid'»tl& 

%eMio4tPWhir^Hl^^#0  k'rtid^^dtfWiW  ktlf^lJl^fiM^ap'^Wtoti^eisAbon 

^Mm  t#e-p^SMrmt'*^*yflifioslAi  it>4>^fl>l*">t\l0  oWttsl!'i?>f  6H}4mfi  antfiWtitiff 

^^;C]XloOft^O^Kl?I^M[tob4^  Unf  Ji'^ior!  ^f  I  raft  *^ff:  a^dw 

sljdfi2)B  V\^^i4h^C't\t4PferW^f^i^ftrPi#W*!^l  ^tlS^'4e?^borftlH«?^<^^i 
atoms  the  acids  are  deeltJ4t»i^^W^fti*(A  WA*^fiWl'i^'^niAiV^i<irt^^|9.B3.%W 


]iT#tfFea'=af*fft^alW«xf^^^ 

actioQ  of  an  alkaline  hv4roxid  in  fusion  upon  sawdugt.     The  ^ftftflS 

%\mm  #|fi!g^imi&^a^^fli^"?M  ffltp^^^M^ftida^'k'cAtim^^^iaw  tb^ 
^ffiv¥ie(|V%Aiiii'iW^w'?il^w^fr  ^a.fer^vftt' to'  iteMm^&ia^ifflflM 

fil^'ce^?   ^te#Hir-^1^til':'"^u^HP/^^(?.;^'t?  thH  *iitSio?f' ot^Pit'di^^^a 
3r«i<«r  to'Hli''illtaril]fe'«6Pma^is  ^ 

io  its  Aq;   at  110^-132^  (23tf^^.(?^V^y  It^^yMWife-^^fe  W/^fi^ 


336 


MANUAL    OF    CnEMTSTRY 


drous  form,  wliile  a  portion  is  decompoged;  above  160*^  (320°  F.) 
the  deconi  posit  ion  is  more  extensive;  Hi-O,  CO^*  CO,  and  foruiif  acid 
are  produced,  while  a  portion  of  the  aeid  is  sublimed  imehaiigetl.  It 
dissolves  in  15,5  parts  of  water  at  10^  (50°  FJ;  the  preseiiee  of 
HNOa  increases  its  sohibility.  It  is  quite  soluble  in  alcohol.  It  has 
a  sharp  taste  and  an  acid  reaction  in  solution. 

Oxalic  acid  is  readily  oxidized;  in  watery  solution  it  is  converted 
into  COl>  and  H2O,  slowly  by  simple  exposure  to  air,  more  rapidly  in 
the  presence  of  platiuum^blnok  or  of  the  salts  of  platinum  and  gold, 
under  the  influence  of  sunlight,  or  when  heated  with  HXO3,  mangan- 
ese dioxid,  chromic  acid,  Br»  CI,  or  hypoehtorons  acid.  Its  oxidation, 
when  it  is  triturated  dry  with  lead  dioxide  is  sufficiently  active  to  heat 
the  mass  to  redness.  H2S04»  HhP04  and  other  dehydrating  agents 
decompose  it  into  II jO,  CO  and  CO2. 

Analytical  Characters. — (l)  lu  neutral  or  alkaline  solution:  a 
white  ppt.  with  a  solution  of  Ca  salt.  (2)  Silver  nitrate:  a  white 
ppt.,  soluble  in  HXOa,  and  in  NH4HO.  The  ppt.  does  not  darken 
when  the  fluid  is  boiled,  but  when  dried  and  heated  on  platinum  foil, 
it  explodes.  (3)  Lead  acetate, in  solutions  not  too  dilute:  a  white 
ppt*,  soluble  in  HNO:i,  insoluble  in  acetic  aeid. 

Toxicology- — Although  certain  oxalates  are  constant  constituents 
of  vegetable  food  and  of  tlje  humaij  body,  the  acid  itself,  as  well  as 
monopotassic  oxalate,  is  a  violent  poison  wheti  taken  internally,  act- 
ing bot!i  locally  as  a  corrosive  upiin  the  tissues  with  which  it  comes 
in  contact  and  as  a  true  poison,  the  predominance  of  either  action 
dependiug  upon  the  conceutratiou  of  the  solution.  Dilute  solutions 
may  produce  death  without  pain  or  vomiting,  and  after  symptoms 
reseuibliug  those  of  narcotic  poisoning.  Death  has  followed  a  dose 
of  4  gm.  of  the  solid  aeid,  and  recovery  a  dose  of  30  gm.  in  solution. 
When  death  occurs,  it  may  be  almost  instantaneously^  usually  within 
half  an  hour;  sometimes  after  weeks  or  months,  from  secondary 
causes. 

The  treatment,  which  must  be  as  expeditious  as  possible,  consists 
in  the  administration, /r,s/,  of  lime  or  maguesia,  or  a  soluble  salt  of 
Ca  or  Mg,  suspended  or  dissolved  in  a  small  quantity  of  H2O  or  mu- 
cilaginous fluid;  afterward,  if  vomiting  have  not  occurred  sponta- 
neously, and  if  the  symptoms  of  corrosion  have  not  been  severe,  an 
emetic  may  be  given.  Tiie  alkaline  carbonates  are  of  no  value  iu 
cases  of  oxalic -acid  poison  iug,  as  the  oxalates  which  they  form  are 
soluble  and  almost  as  poisonous  as  the  acid  itself.  The  ingestion  of 
water,  or  the  administration  of  warm  water  as  an  emetic,  is  contra- 
indicated  when  the  poison  has  been  taken  in  the  solid  form  (or  where 
doubt  exists  as  to  what  form  it  was  taken  in),  as  they  dissolve,  and 
thus  favor  the  absorption  of  the  poison. 


CAEBOXVLIC    ACIDS 


337 


I 


Malonic  Acid  ^-^  CH2<f (^-OOll  —  ^'^  ^^  product  of  the  oxidation  at 
malie  aeid  (p.  344) »  or  of  nonoal  propyl  glyeol.  It  is  best  obtained 
by  the  general  method  4,  p,  335,  Monoehloraeetic  aeid  is  converted 
into  cyano- acetic  acid  by  heating  in  alkaline  solution  with  KCNs 
CHsCLCOOH-f  KCN=CN.CH2.C00H  +  K:cI.  The  cyano-acid  is 
then  hydrolysed  by  heating  with  KHO  or  HCl,  thus:  CN.OHo,- 
COOH+2H3O-=C00H.CH2.COOH  +  NH3.  It  forms  large  pris- 
matic crystals,  solnble  in  water,  alcohol  and  ether;  fnsible  at  132^^ 
(269.6^  F.).  and  decomposed  at  about  150°  (302°  FJ  into  acetic 
aeid  and  earlion  dioxid.  Bt'cause  of  the  position  of  the  CH-j  group, 
between  two  CO  groups,  malonic  aeid  18  nllied  to  the  0  kc tonic  acids 
(p.  347),  and  its  esters  undergo  synthetic  reactions  similar  to  those 
of  acetoacetic  ester  (p.  360). 

Cih—cmm 

Succinic  Acid —  |  — 118  —  exists  in  amber,  coal,  fossil 

CHj— CCK)H 
wood»  and  iu  small  quantity  in  animal  and  vegetable  tissues.  Its 
presence  has  been  detected  in  the  normal  uriue  after  the  use  of  fruits 
and  of  asparagus,  in  the  parenchymatous  fluids  of  the  spleen,  thyroid, 
and  thymus,  and  in  the  fluids  of  hydrocele  and  of  hydatid  cysts.  It 
is  also  formed  in  small  quantity  during  alcoholic  fermentation ;  as  a 
product  of  oxidation  of  many  fats  and  fatty  acids;  and  by  synthesis 
from  ethylene  eyanid:CN.(CH.)2,CN+4H20=-COOH.(CH2)-2.COOH+ 
2NH3.  It  may  also  be  obtained  by  dry  distillation  of  amber,  or  by  the 
ferraentation  of  malic  acid  {p,  344). 

It  crystallizes  in  large  prisms  or  hexagonal  plates,  which  are  color- 
less, odorless,  permanent  iu  air,  acid  in  t^iste,  soluble  in  water,  spar- 
iogly  so  in  ether  and  in  cold  alcohol.  It  fuses  at  180"^  (356°  FJ,  and 
distilfi  with  partial  decomposition  at  23r>'^  (455*^  F.).  It  withstands 
tbe  action  of  oxidizing  agents.  Reducing  agents  convert  it  into  the 
corresponding  acid  of  the  fatty  series,  butyric  acid.  With  Br  it  forms 
products  of  substitution,  H2SO4  is  without  action  upon  it.  Phos- 
pboric  auhydrid  removes  H2O  and  converts  it  into  succinic  an- 
hydrid,  C4H403. 

Isosuccinic  Acid  —  3Mhif  I -malonic  acid  —  CH3  .CH<^  cooR  —  ^^ 
formed  by  the  action  of  hydrating  agents  upon  a  cyanopropionic  acid. 
It  forms  prismatic  erystals,  fusible  at  130*^  (266*^  F.),  and  is  decom- 
posed at  higher  temperatures  into  propionic  acid  and  carbon  dioxid, 

Glutaric  Acid— C00FL(CH2)aX00n— iV'onwa/  Pifrotartaric  acid 
— the  next  superior  homologue  of  succinic  acid,  is  formed  by  rednc- 

ttiou  of  «  oxyglutarie  acid  (p.  344).  It  crystallizes  in  large  plates, 
rtry  soluble  in  water,  which  fuse  at  27"^  (206.4  ^'FJ.  The  corre* 
ipouding  amido-acid  is  one  of  the  products  of  decomposition  of  pro- 
Itio  bodies* 


P 


338  MANUAL    OF    CHEMISTRY 

The  p3rrotartaric  acid  obtained  by  the  action  of  heat  on  tartaric 
acid  is  methyl-succinic  acid,  COOH.CH(CH3).CH2.COOH,  which 
may  also  be  produced  synthetically  by  the  action  of  nascent  H  upon 
itaconic  acid,  COOH.C(:CH2).CH2.COOH,  as  weU  as  by  other 
methods.  It  fuses  at  112°  (233.6°  P.),  and  forms  rhombic  prisms, 
very  soluble  in  water,  alcohol,  and  ether. 

Adipic  Acid— COOH.(CH2)4.COOH— is  a  product  of  the  action 
of  nitric  acid  on  fats:  Pimclic  acid,  COOH.(CH2)5.COOH,  and 
Suberic  acid,  C00H.(CH2)e.C00H— are  similarly  obtained  from 
€ork.  Azelaic  acid,  CoHieOi,  Sebacic  acid,  CioHisOi,  Brassylic  acid, 
CUH20O4,  and  Rocellic  acid,  C17H32O4,  also  belong  to  this  series. 

PARAFFIN    TRI-,   TETRA-,   AND    PBNTA-CARBOXYLIC    ACIDS. 

Tricarboxylic  Acids  in  which  more  than  one  carboxyl  are  at- 
tached to  the  same  carbon  atom  exist  only  in  their  esters.  The 
simplest  of  these:  Methenyl  tricarboxylic  ester,  CH(COO.C2H5)3,  is 
a  crystalline  solid,  fusing  at  29°  (84.2°  F.),  and  boiling  at  253° 
(487.4°  F.). 

Tricarballylic  Acid— CH2.  (COOH)  .CH(COOH)  .CH2(C00H)— in 
which  the  carboxyls  are  attached  to  different  carbon  atoms,  is  a  more 
stable  compound.  It  exists  in  unripe  beets  and  in  the  vacuum  pan 
residues  of  beet -sugar  works.  It  is  formed  by  a  variety  of  reactions, 
as  by  heating  tribromhydrin  with  potassium  cyanid  and  decomposing 
the  cyanid  with  potash:  CH2Br.CHBr.CH2Br+3kCN=CH2CN.- 
CHCN.CHoCN  +  3KBr,  and  CH2CN.CHCN.CH2CN  +  6H2O  =  CH2- 
COOH.CH.COOH.CH2COOH  +  3NH3.  It  forms  rhombic  prisms 
soluble    in  water,  fusible  at  164''  (327.2°  F.). 

Camphoronic  Acid — ouiP  trimethyl- tricarballylic  acid — (CH3)2C- 
(COOH).(CH3)C(COOH).CH2(COOH)— is  a  product  of  oxidation  of 
camphor  (q.  v.). 

Dimalonic  Acid— eCoH/^^-^^\COOH— ^^^  simplest  of  the 
tetracarboxylic  acids,  is  a  crystalline  solid,  fusible  at  168°  (334.4° 
F.).  On  further  heating  it  yields  ethylene  succinic  acid:  (COOH)2- 
CH.CH(COOH)2=COOH.CH2.CH2.COOH+2C02. 

Propenyl-pentacarboxylic  acid— C3H3(COOH)5 — is  also  known. 


ALCOHOL-ACIDS— OXYACIDS. 

These  acids  contain,  besides  the  carboxyl  group,  one  of  the 
groups  CH2OH,  CHOH,  or  GOH,  which  characterize  the  primary, 
secondary,  and  tertiary  alcohols.  They,  therefore,  have  the  function 
of  alcohols,  primary,  secondary,  or  tertiary,  as  well  as  that  of  acids: 


AIXOHOL^  ACIDS-OX  YACIDS 


33D 


CH^on 

OOOE 


)H 


eiyeolUe  Add 


CH3 

CHOH 

COOH 

(nrfreoudiUT)- 


II 
COH 

COOH 

a  OxTiiobntrrte  MldE 


They  may  be  considered  as  derived  either  from  the  di-  and  poXya- 
tomie  alcohols  (glycols,  glycerols »  etc.)  by  incomplete  oxidation,  as 
COOH.CHiOn  from  CnoOII.CH^OH;  or  from  the  pure  acids  by  mh- 
EtitutioD  of  OH  for  H  atoms  in  the  remainiug  hydrocarbon  groups, 
as  CH2OH.CH2*CK2.0OOH  ;   CUmOH.CHOH.CHoX'OOH,  and  CH2- 

■     OH,CHOH.CnOH.C0OII  from  CH3.CH2.CH2.COOH. 
The  bfu^icitij  of  these  acids  is  represented  by  the  number  of  car- 
boxyl  groups  which  they  contain,  their  atomicity  by  the  number  of 
hydroxyls.     Thus  CHoOH. CHOH. COOH  is  monobasic  and  triatoraic. 

^The  algebraic  formula  of  the  several  monobasic  series  are  C-Ha-Oa; 
CwM2m04,CnIl2n05r  ctc,  thosc  of  the  dibasic  series  C»H3i.-20&»C«H2«-20et 
elc.;  and  those  of  the  tribasic  series  CnU^^^ih.CHB.^n^Os,  etc. 


OSTACETIC    SERIES-       C»H2k03. 


The  acids  of  this  series  contain  one  carboxyl  and  one  alcoholic 
group.  They  are,  therefore,  monobasic  and  diatom ie,  and  may  be 
considered  as  derived  from  the  glycols  by  oxidation  of  one  CH2OH 
group,  or  from  the  acids  of  the  acetic  series  by  substitution  of  OH  for 
H  in  a  hydroearl»on  group  (oxyaeetic). 

They  are  formed:  (1)  By  the  limited  oxidation  of  the  correspond- 
ing glycols  or  oxyaldehydes:  CH20n.CH20H+O2^CH2OH.CO0H+ 
H2O,  or,  2CH2OH.CH0+0n=2CH4JH.C0OH;  (2)  By  the  action  of 
nascent  hydrogen  upon  the  aldehyde  or  ketone  aeids  (p*  346),  or  upon 
the  acids  of  the  oxalic  series:  CHO.COOH  +  H.^CHsOH.COOH,  or, 
CH».CO  C0OH+H2=CHa.CH0H.C00H,  or,  COOH.COOH+2H2-= 
CO2OH.COOH+H2O  ;  (3)  By  heating  the  monohalogen  fatty  acids 
with  silver  or  potassium  hydroxids.  or  with  water:  CH2CI.COOH+ 
KUO=CH20H.COOH  +  KCl.  or.  CH2C1.C00H  +  H,0=HC1  +CH2- 
on. COOH;  (4)  From  the  aldehydes  and  ketones,  by  their  conver- 
aion,  first  into  oxyeyanids  by  the  action  of  hydrocyanic  acid:  CH3.- 

and  the  action  upon  these  of  acids  or 


CHO+HCN=Cna.CH<^f/N, 

r/OH 


alkalies:  CHa.CHC  eN+2H20-^CH3.CH0H,C00H+NH3. 

Isomeres — Position  or  Place  Isomery, — Considering  the  oiy- 
bntyric  acids  as  derived  from  normal  and  isobutyric  acids  by  substi- 
totion  of  one  OH  for  a  hydrogen  atom  in  a  hydrocarbon  group,  the 
toUowing  five  derivatives  are  possible  i 


340 


MANUAL    OF    CHEMISTRY 


OH3 

I 
CH2 

I 
CH2 

I 
COOH 

Normal 

Butyric 

acid. 


I. 
CH3 

I 
CH2 

I  I 

CHOH    CH, 


in. 

CHjOH 


n. 

CH3 

I        I 

CHOH    CHj 

I  I 

CHs 


H3C    CH3 

\/ 
CH 


IV. 
H3C    CH2OH 

\/ 
CH 


I 

COOH    COOH 
Alpha        BeU 


Oxy. 

bntyrie 

acid. 


Oxy 

bntyrie 


COOH 

Gamma 
Oxy- 

bntyrio 
add. 


COOH  COOI 


Iiolmtyrie 
add. 


BeU 
Oxyiaobntyrie 
add. 


V. 
H,C    CH3 
\/ 
COH 

I 
COOH 


Alpha 

Oxyisobutyrie 

add. 


While  III,  IV,  and  V  are  obviously  different  in  molecular  struc- 
ture from  each  other  and  from  I  and  II,  in  that  the  latter  contain  the 
group  CHOH,  while  the  former  contain  the  groups  CH20H,CH,  and 
COH,  the  only  difference  between  I  and  II,  whose  molecules  are  com- 
posed of  identical  groups,  is  in  the  position  or  place  of  the  alcoholic 
hydroxyl  with  reference  to  the  carboxyl  group.  Place  isomeres  of 
this  kind  are  distinguished  by  designating  that  in  which  the  second 
substituted  group  (in  this  case  the  OH)  is  attached  to  the  carbon 
atom  contiguous  to  the  first  as  the  alpha,  or  1- compound,  and  the 
others  by  the  succeeding  Greek  letters,  or  by  the  numerals  in  the 
order  of  the  removal  of  the  position  of  the  second  substitution.  Thus 
II  above  is  Beta  oxybutyric  or  2-oxybutyric  acid.  (See  Orientation, 
p.  436.) 

The  a,  P,  y,  and  S  acids  differ  in  their  products  of  dehydration: 
The  a  acids  yields  cyclic  double  esters,  called  lactids,  by  elimination 
of  H2O  from  two  molecules  of  the  acid  (p  368).  The  j9  acids  are 
converted  into  unsaturated  acids  by  loss  of  H2O  from  one  molecule  of 
the  acid:  CH20H.CH2.COOH  =  CH2:CH.COOH+H20.  The  y  and  « 
acids,  and  those  of  greater  carbon  content,  are  converted  into  simple 
cyclic  esters,  called  lactones,  by  elimination  of  H2O  from  a  single 
molecule  of  the  acid  (p.  368). 

By  further  oxidation  tlie  primary  oxyacids  containing  CH2OH 
yield \aldehyde  acids:  2CH20H.Co6n+02  =  2CHO.COOH+2H20, 
and  then  dibasic  acids:  2CHO.COOH+02  =  2COOH.COOH;  the  sec- 
ondary acids,  containing  CHOH,  yield  ketone  acids:  2CH3.CHOH.- 
COOH+02=2CH3.CO.COOH+2H20,  and    the   tertiary  acids,   con. 

CH  \ 

tainiug  COH,  yield  ketones,  carbon  dioxid  and  water  :  2(>h^J)C0H.- 
COOH+02=2CH3.CO.CH3+2C02+2H20. 

The  hydrogen  of  their  carboxyl  group  may  be  replaced  to  form 
salts,  esters,  or  amids ;  and  the  hydroxyl  of  their  alcoholic  group 
may  be  replaced  by  alkali  metals,  alkyls,  or  acidyls.  In  other  words, 
they  behave  as  acids  and  as  alcohols. 

Oxyformic  Acid — Carbonic  acid— 0C(0H)2. — Although  this  acid 
does  not  exist  free,  but  is  decomposed  as  soon  as  liberated  into  CO2 
and  H2O  (p.  269),  its  salts,  the  carbonates,  are  well  known  and  quite 


ALCOHOL-ACrOS— OXYArins 


911 


I 


CH20H 

/OH 

1         - 

CH2 

=    OC 

COOH 

\0H 

OljcolUc  acid, 

C&rboDle  seld. 

Stable.      Tie  position  of  this   acid   in   this   series   is   an  apparent 

anomaly,  as  it  is  dibasic,  not  monobasic  like  the  other  terms  of  th© 

series*     But  if  we  bear  in  raind  that  the  basic  nature  of  the  H  atom 

in  a  hydroxyl  depeuds  upon  its  close  union  with  a  CO  group  {or  some 

^         other  electro  negative  group),  it  is  evident  that  the  two  H  atoms  in 

■      the  inferior  homologue  of  glycollic  acid,  being  similarly  united  to  the 

B     same  CO  group,  must  he  equally  basic  : 

H  Indeed,  carbonic  acid  is  not  an  alcohol  acid,  but  a  pure  acid,  as  it 

H     contains  no  alcoholic  group. 

f  Esters   are   also    known   corresponding   to   orthocarbonic    acid: 

C(OH)4,  although  the  acid  itself  is  unknown. 

Glycollic  Acid — Oxyacetic  acid— CH2OH. COOH— is  formed  by 
the  oxidation  of  glycol,  by  the  action  of  nitrous  acid  upon  glycocoll, 
and    by  the   action   of  KHO   upon   monochioracetie  acid,  or  upon 

^     glyoxal,  CHO.CHO.  * 

B  It  forms  deliquescent  acicnlar  crystals,  very  soluble  in  water,  alco- 

hol and  ether.  It  fuses  at  80""  (176'^  F.).  It  is  oxidized  by  HNO3  to 
■  oxalic  acid. 
L.actic  Acids — Oxypropionic  acids — Alpha  oxypropionic  acid — 
Eihidene  lactic  acid — CHaX-HOILCOOPl^is  formed  from  milk  sugar, 
cane  sugar,  gum  and  starch  by  hictic  fermenfalion,  induced  by  the 
lactic  acid  bacillus.  It  consequent^-  exists  in  many  soured  products, 
saeh  as  soured  milk,  sour*krout,  fermented  beet-juice,  and  the  waste 
liqnors  of  starch  works  and  of  tanneries.  It  is  formed  in  the  stomach 
daring  digestion  of  carbohydrates.  It  is  prepared  by  allowing  a  mix- 
ture of  cane  sugar,  tartaric  acid,  rotten  cheese,  skim  milk  and  chalk 
to  ferment  for  ten  days  at  35^  (95°  PJ.  It  has  also  been  obtained 
br  oxidation  of  alpha  propylene  glycol  :  CH3.CH0H.CH30H+O2^= 
Cfti.CHOHCOOH+HnO. 

Lactic  acid  of  fermentation  is  a  colorless,  or  yellowish,  synipy 
liqnid:  sp.  gr.  l,2iri  at  20'^  (GS'^F/);  soluble  in  water,  alcohol  and 
ether.  It  does  not  distil  without  decomposition,  but  when  heated  it 
yields  lactid  (p.  368),  carbon  monoxid,  aldehyde  and  water.  Oxid- 
fzing  agents  convert  it  into  pyroraceniie  acid:  CH3.CO.COOH;  or, 
if  tnore  eiierjjetie,  split  it  up  into  acetic  acid  and  carbon  dioxidr 
CHa.CnOH,COOH+02=CH3,COOH  +  C02+H20.  Heated  to  130"* 
(266^  F.)  with  dilute  sulfuric  acid  it  splits  into  aldehyde  and  formic 
aeid:  CH3.CHOH.COOH  =  CRaCHO+H  COOH.  Hydriodic  acid 
redacei^  it  to  propionic  actd;  but  hydro bromic  acid  converts  it  into 
«*broinoproplonic  acid. 


342  MANUAL    OF    CHEMISTRY 

'  Ethidene  lactic  acid  contains  an  asymmetric  carbon  atom  (p.  312)  : 
CH3.C*H0H.C00H;  and  that  produced  by  lactic  fermentation  is 
optically  inactive  (d+1).  The  dextro  acid,  also  known  as  sarcolactic 
or  paralactic  acid,  is  best  obtained  from  Liebig's  meat  extract;  and 
is  also  produced  by  allowing  Penicillium  glaucum  to  grow  in  a  solu- 
tion of  inactive  ammonium  lactate.  It  exists  in  muscular  tissue  after 
death  and  during  contraction,  and  in  the  spleen,  lymphatic  glands, 
thymus,  thyroid,  blood,  bile,  transudates,  in  the  perspiration  in  puer- 
peral fever,  and  in  the  urine  after  violent  exercise,  in  yellow  atrophy 
of  the  liver  and  in  phosphorus  poisoning,  either  free  or  in  com- 
bination. The  acid  in  muscular  tissue  probably  originates  from 
glycogen. 

Laevolactic  Acid  is  formed  by  the  growth  of  Bacillus  addi  lae- 
volacfici  in  a  solution  of  cane  sugar. 

Ethylene  Lactic  Acid — Beta  oxypropionic  acid  —  Hydracrylic 
acid— CH2OH.CH2.COOH— the  third  form  of  lactic  acid,  is  formed 
by  the  action  of  moist  silver  oxid  upon  )8-iodo-  or  ^-chloropropionic 
acid;  by  the  saponification  of  ethylene  cj'anhydrin;  or  by  the  oxida- 
tion of  the  corresponding  glycol.  It  is  a  thick,  uncrystallizable 
syrup,  which  is  converted  by  dehydration  into  acrylic  acid  CH2OH.- 
CH2.COOH=CH2:CH.COOH+H20.  On  oxidation  it  yields  oxalic 
acid  and  carbon  dioxid:  2(CH20H.CH2.COOH) +502  =  2(COOH.- 
COOH ) +2CO2+4H2O . 

Oxybutyric  Acids. — Five  isomeres  are  possible  (p.  340).  Beta 
oxybutyric  acid— CH3.C*HOH.CH2.COOH,  is  formed  by  the  action 
of  sodium  amalgam  upon  acetoacetic  ester  (p.  360)  CH3.CO.CH2.- 
€OOH+H2  =  CH3.CHOH.CH2.COOH.  The  IsBvo-acid,  a  colorless 
«yrup,  readily  soluble  in  water,  alcohol  and  ether,  occurs,  accom- 
panied by  acetoacetic  acid,  in  the  blood  and  urine  in  severe  cases  of 
diabetes. 

Alpha  Oxycaproic  Acid— CH3.(CH2)3.CHOH.COOH— is  leucic 
acid,  obtained  by  oxidizing  leuciu  (p.  414)  by  nitrous  acid. 

HIGHER  MONOCAKBOXYLIC   OXYACIDS. 

Representatives  of  the  following  series  are  known: 
Dioxymonocarboxylic  Series,  Glyceric  Series — C«H2i.04. — The 
acids  of  this  series  bear  the  s^me  relation  to  the  glycerols  that  those 
of  the  oxyacetic  series  bear  to  the  glycols.  Glyceric  acid,  CH2OH.- 
C*HOH.COOH,  is  an  uncrystallizable  syrup  obtained  by  the  limited 
oxidation  of  glycerol. 

Trioxymonocarboxylic  Series — C«H2«05 — of  which  erythritic,  or 
«rythroglucic  acid:  CH20H.(CHOH)2.COOH,  derived  from  erythrol 
(p.  297)  is  the  first  term. 


i 


WOL-ACTDS^OXYACTDS 


343 


Tetroxymonocarboxylic  Series — C»H2».0« — are  obtained  by  oxida- 
tion of  the  aldopetitoses  (p.  310). 

Pentoxymonocarboxylic  Scrics^ — C«H2«0t — are  obtained  by  oxi- 
dation of  the  hexahydric  alcohols  and  aldohexoses.  Synthetically, 
they  are  produced  from  the  aldopentoses,  by  their  conversion  into 
nitrils  of  the  oxyacids  by  CNH,  and  the  action  upon  these  of  HCl, 
thus  1-arabinose  CH20H.(CHOH)3.CHO  yields  l-glucononitril,  Clh- 
rOH.(CHOH)3.CH(0H)CN»and  this  yields  1- gluconic  acid.  CH^OH.- 
(CHOH)4.C00H. 

These  acids  are  very  unstable  when  free,  easily  losing  water  to 
form  lactones  (p.  368).  They  readily  unite  with  phenylhydrazin  to 
turm  phenylhydrazids,  such  as  gluconophenyl  hydrazid:  CHgOH.CCH- 
OH)4.CO.NH.NH.CeH5.  which  crystallize  in  characteiistic  forms  (pp, 
311.  485)*  They  form  numerous  space  isomeres.  Their  lactones 
eated  with  sodium  amalgam,  take  up  H^  and  produce  the  corre- 
r«poDding  aldohexoses:  thus  glueonolactone  yields  ghicose. 

Mannonic  Acids— CsHef OH) 5.CUOH.— The  three  acids,  d-,  I*, 
and  (d+l)»  derived  from  the  corresponding  mannitols,  yield  the  cor- 
respondiog  dibasic  mannosaccharic  acids  on  oxidation.  They  are 
syrupy  liquids,  which  are  converted  into  their  lactones  by  evaporation 
of  their  solutions.  On  heating  d-  and  l*mannonic  acids  with  quin- 
olin  to  140"^  (284^  F J,  they  are,  in  part,  converted  into  d-  and  1- 
i^lucouie  acids.  By  this  action  and  the  subsequent  conversion  of 
glaconolactone,  referred  to  above,  glucose  may  be  synthetically  ob- 
tained from  mannitoL 

Gluconic  Acids  — CIT20H.(CriOH)4.COOH— The  d-,  1,  and 
(d+1)  acids  are  known.  By  oxidation  they  yield  the  corresponding 
saccharic  acids.  The  lactones  yield  d-,  1-,  and  (d+l)  glucose  by 
reduction.  d-(tht€onic  acid,  also  known  as  dextronic  or  maltonic 
acid,  is  a  syrup  which  forms  a  crystalline  lactone  on  evaporation  of 
iU(  solution.  It  is  formed  by  oxidizing  dextrose,  dextrin,  starch,  cane 
sagar,  or  maltose  by  chlorin  or  bromin  water. 

Acids  belonging  to  the  still  higher  series  C«H2«Ofi,C«H2nOo,  and 
C^H^^Oio,  corresponding  to  the  heptoses,  oetoses  and  nonoses  (p.  309) 
are  also  known  • 

MONOXYDICARBOXTTLIC    SEE  I  ES-*C«H  2^-205. 


The  acids  of  this  series  contain  two  carboxyls  and  one  alcoholic 
g^^up.  They  are,  therefore,  dibasic  and  triatomic»  and  may  be  con- 
sidered as  derived  from  the  glycerols  by  oxidation  of  both  CHaOH 
groups.  They  may  also  be  considered  as  derived  from  the  paraffin 
dicarboxylic  acids  (oxalic  series),  above  the  first,  by  substitution  of 
OH  for  H  in  a  hydrocarbon  group,  in  the  jsame  manner  as  the  acids 


344 


MANUAL    OF    THEMISTRY 


of  the  oryacetic  series  are  derived  from  those  of  the  aeetic  series 

(p.  339). 

Tartronic  Acid  — Oxymalonic  acid  — COOH.CHOH.COOH— is 

formed   by   the   action   of   moist  silver   uxid   upon    monoehloro*  or 
mooobrorao-malooie  acid»  or  by  oxidation  of  glycerol  by  potassium 
perraanganate.      It  crystallizes    in  large   prisms,  readily  soluble  in 
water,  alcobol,  and  ether,  and  fusible  at  IM"*  (363.2*^  FJ. 

Malic  Acid  — Oxysuccinic  acid— COOHXlH^.C^HOH.COOH- 
existg  in  three  mod ifteat ions.  The  l{f^vo-aeid  exists  free,  and  in  com- 
bination with  K»  Na,  Ca,  Mg,  and  organic  bases  in  apples,  pears, 
and  similar  fruits,  and  in  the  berries  of  the  mountain  ash  and  in 
gooseberries.  The  inacti%^e  (d+1),  acid  may  be  obtained  from  mono- 
bromo-snccinie  acid  by  the  action  either  of  moist  silver  oxid,  of  dilute 
HCl,  of  dilute  NaHO,  or  even  of  boiling  water;  and  by  several  other 
methods.  The  dextro-acid  is  obtained  by  the  reduction  of  dextro* 
tartaric  acid  by  hydriodic  acid. 

The  natural  malic  acid  crystallixes  in  prismatic  needles;  odorless; 

acid  in  taste?   fusible  at  100°  (212^  F.);    deliquescent;   very  soluble 

in  water  and  in  alcohol.     Heated  to  140*^  (284°  F.)  it  loses  water 

with  formation  of   fumaric  acid,  COOH.CH:CH.COOH,      At  180"* 

CH.CO\ 

(356   F.)  it  yields  water,  fumaric  acid  and  nialelc  anhydrid,  II  O. 

CH.coy 

Reducing  agents  convert  it  iutx>  succinic  acid.     The  malates  ai-e  oxi- 
dized to  carbonates  in  the  bod3\ 

Oxyglutaric  Acid  exists  in  the  two  isomeres:  ft  oxyglntarie  acid, 
COOFLCH(On).CH2.CH2.COOH,  which  occm*s  in  molasses,  crystal- 
lizes with  diflficulty*  and  fuses  at  72*^  (161, 6"^'  F.);  and  ^oxyglutaric 
acid,  COOH.CH2.CHOH.CH2.COOH,  which  fuses  at  95°  (203°  F.). 

DIOXYDICARBOXYLIC   ACIDS— C«Ha»-206. 

Tartaric  Acids —  Dioxyethylene  Succinic  Acids.  —  There  exist 
four  acids  having  the  composition  C^HoOe,  which  are  readily  convert- 
ible one  into  the  other.  They  are:  DextrO'tarfarir,  or  ordhwrff  tar- 
taric acid ;  hrvo-t^trtfrnc  aeid;  mesotarfarlc,  or  antitarfarir  acid;  and 
racemic,  or  paratartanc  acid.  The  first  three  of  these  are  stei'eo iso- 
meres, due  to  the  presence  of  two  asymmetric  carbon  atoms  in  the 
molecule,  whose  molecnlar  stnicture  has  been  discussed  under  the 
head  of  space  isomery  (p.  312).  Mesotartaric  acid,  which  is  opti- 
cally inactive,  has  a  molecular  structure  differing  from  those  of  the  d- 
and  1-  acids »  into  which  it  cannot  be  split.  Racemic  acid,  also  opti- 
cally inactive,  is  the  (d+l)  acid,  and  can  be  readily  decomposed  into 
them  or  separated  from  a  mixture  of  them. 

Dextro- tartaric  Acid — Ordinary  tartarie  acid — Acidum  iartaricuM 


I 


ALCOHOL- ACIDS— ox  YACTD8  315 

(U.  S.;  BrJ — occurs,  both  free  and  in  combination,  in  the'sap  of  the 

vine  and  in  many  other  vegetable  juices  and  fruits,  particnlarly  in 
grape-juiee.  Althongh  this  is  probably  the  only  tartaric  acid  existing 
in  nature,  all  four  varieties  may  occur  in  the  commercial  acid,  being 
formed  during  the  process  of  manufacture.  Tartaric  acid  is  obtained 
in  the  arts  from  hydropotassic  tartrate,  or  cream  of  tartar  (p,  290). 

The  ordinary  tartaric  acid  crystallizes  in  large  prisms;  very  sol- 
nble  in  H2O  and  in  alcohol;  acid  in  ta^te  and  inaction.  Heated  witli 
water  at  165°-175°  (329'''-347°  P.)  it  is  converted  into  mesotartarie 
and  racemic  acids.  It  fuses  at  170°  (338°  P.) ;  at  180°  (356°  F.)  it 
loses  H2O,  and  is  gi*adually  converted  into  an  arihydrid;  at  200°-2in° 
(392°-410*^'  FJ  it  is  decomposed  with  torraatiori  of  pyruvic  acid» 
CSH4O3  (p.  347)  t  and  pyrotartaric  acid,  C'sH^O*,  (p.  338);  at  higher 
temperatures  CO2,  CO,  HjO,  hydrocarbons  and  charcoal  are  produced. 

Tartaric  acid  is  attacked  by  oxidizing  agents  with  formation  of 
CO2,  H2O,  and,  in  some  instances,  formic  and  oxalic  acids.  Certain 
reducing  agents  convert  it  into  malic  and  succinic  acids.  With  fmn- 
ing  HNO3  it  forms  a  dinitro*eompound,  which  is  very  unstable,  and 
which,  when  decomposed  below  36°  (96.8*^  F.)»  yields  tartaric  acid. 
It  forms  a  precipitate  with  lime-water,  soluble  in  an  excess  of  H^O. 
In  not  too  dilute  solution  it  forms  a  precipitate  with  potassium  sulfate 
'Solution.  It  does  not  precipitate  with  the  salts  of  Ca.  When  heated 
with  a  solution  of  auric  chlorid  it  precipitates  the  gold  in  the  metallic 
form. 

When  taken  into  the  economy,  as  it  frequently  is  in  the  form  of 
tartrates,  the  greater  part  is  oxidized  to  carbonic  acid  (carbonates); 
jbat,  if  taken  in  sufficient  quantity,  a  portion  is  excreted  unchanged 
In  the  urine  and  perspiration.  The  free  acid  is  poisonous  in  large 
doses.  The  acids  and  its  salts  are  largely  used  in  pharmacy  and  in 
dyeing. 

Lavo-tartaric  —  forms  crystals  similar  to  those  of  the  dextro  acid, 
but  having  opposite  hemihedral  facets  (p,  16),  so  that  the  crystals  of 
•one  acid  resemble  the  reflection  of  those  of  the  other  in  a  mirror. 
I  Racemic  Acid — (f?+0  Tartaric  add — is  produced  when  cowcen- 
'trated  solutions  of  equal  quantities  of  d-  and  1- tartaric  acids  are 
mixed.  It  is  formed  by  oxidation  of  dulcitol  and  of  manoitol.  It  is 
obtained  by  the  action  of  moist  silver  oxid  up*tn  dibromo  succinic 
Pacid.-COOH.CHBr.CrTBr.COOIH-  2AgH0  ^  COOH.CHOH.CHOH.- 
'C00H+2AgBr;  and  by  several  other  synthetic  methods.  It  crys- 
tallizes in  rhombic  prisms,  less  soluble  in  water  than  ordinary  tartaric 
.acid,  and  fuses  at  205°  (410°  F.). 

'  Mesotartarie  Acid— Inactive  Tartaric  acid — is  obtained  by  oxida* 
tion  of  erythrol;  or  by  heating  dextrotartaric  acid  with  water  at  165^ 
(329°  F.)  for  two  days. 


346  MANUAL    OP    CHEMISTRY 

HIGHER    DICARBOXYLIO    OXTACIDS. 

The  carbohydrates,  on  oxidation  with  nitric  acid,  3rield  tetroxy^ 
dicarboxylic  acids:  C00H.(CH0H)4.C00H.  Among  these  are: 
mannosaccharic  acids,  derived  from  the  mannonic  acids  (p.  343) ; 
saccharic  acids ;  and  mucic  acid.  Of  the  three  saccharic  acids  the 
d-acid  is  the  best  known.  It  is  produced  by  oxidation  of  many  car- 
bohydrates, including  cane  sugar  and  grape  sugar,  by  nitric  acid,  and 
by  the  action  of  bromin  water  on  glucuronic  acid  (p.  348).  Nascent 
H  reduces  it  to  glucuronic  acid.  It  forms  a  syrup  or  a  deliquescent 
solid,  which,  on  standing,  changes  to  a  crystalline  lactone.  Macic 
acid  is  produced  by  the  oxidation  of  dulcitol,  milk  sugar,  and  the 
gums.  It  is  a  white  solid,  almost  insoluble  in  cold  water  and  in 
alcohol,  which  fuses  at  210°  (410°  F.).  When  heated  it  loses  CO2 
and  forms  pyromucic,  or  furfurane  monocarhoxylic  acid  (p.  510). 

Pentoxydicarboxylic  acids  are  also  known,  of  which  the  type  is 
pentoxypimelic  acid:  C00H.(CH0H)5.C00H. 

OXYTRICARBOXYLIC    ACIDS— C«H2i.-407. 
/CH2.COOH 

Citric  Acid — HO.C— COOH  exists  in  the  juices  of  many  fruits, 

\CH2.COOH 

lemon,  strawberry,  currant,  and  in  small  quantity,  as  calcium  citrate, 
in  cow's  milk.  It  is  obtained  commercially  from  lemon  juice.  If 
crystallizes  in  large,  rhombic  prisms,  very  soluble  in  water  and  in 
alcohol.  It  fuses  at  100°  (212°  F.);  at  175°  (347°  F.)  it  is  decom- 
posed with  loss  of  water  and  formation  of  aconitic  acid  (p.  431) ;  and 
at  a  higher  temperature  CO2  is  given  off  and  citraconic  and  itaconic 
acids  are  produced.     In  the  body  its  salts  are  oxidized  to  carbonates. 


ALDEHYDE- ACIDS. 

These  are  substances  having  both  aldehyde  and  acid  functions^ 
and  containing  the  groups  CHO  and  COOH.  The  simplest  of  th^ 
•class  is  formic  acid,  already  referred  to  as  the  first  term  of  the  acetiC5 
series  (p.  328),  iu  which,  however,  the  carbon  atom  is  common  to  the 

two  groups:   0:C\^Qj:j 

Glyoxylic  Acid — CHO. COOH — when  produced  unites  with  water 
to  form  a  hydrate;  (0H)2:CH.C00H,  corresponding  to  chloral  hy- 
drate (p.  304)  :(OH)2:CH.CCl3.  This  is  a  thick  syrup,  or  it  forms 
rhombic  prisms.  It  is  produced  by  heating  dichloracetic  acid  with 
water  at  230°  (446°  F.)  :  CHCl2.COOH+H20=CHO.COOH+2HCl. 
It  has  the  reducing  power  and  other  properties  of  the  aldehydes. 


KET0NE-ACID8  347 

KETONE -ACID& 

These  conipoands  contain  both  the  ketonic  and  carboxyl  groups, 
CO  and  COOH. 

The  monoketone-monocarboxylic  acids  contain  one  CO  and  one 
COOH.  According  as  the  CO  group  occupies  the  position  adjacent 
to  the  carboxyl,  or  further  removed  therefrom,  these  acids  are  desig- 
nated as  a,  )8,  y,  etc.;  thus  CH3.CH2.CO.COOH=a,  CH3.CO.CH2.- 
COOH=)8,  etc. 

The  a,  y,  S,  etc.,  acids  are  much  more  stable  than  the  ^- acids,  and 
may  be  obtained  by  oxidation  of  the  corresponding  secondary  alcohol 
acids.  The  a  acids  are  derivable  from  formic  acid  by  substitution  of 
acidyls  for  the  extra -carboxylic  hydrogen:   (CH3.C0).C00H. 

Pyruvic  Acid — Pyroracemic  acid — CH3.CO.COOH — is  formed  by 
oxidation  of  a-oxypropionic  acid  :  2CH3.CHOH.COOH+02=2CH3.- 
CO.COOH+2H2O.  It  is  also  formed  by  distillation  of  tartaric  acid  : 
COOH.CHOH.CHOH.COOH=CH3.CO.COOH+C02+H20. 

The  j8-ketone  acids  are  more  unstable,  and  are  decomposed  by 
heat  with  formation  of  ketone  and  carbon  dioxid:  COOH.CH2.CO.- 
CH3=C02+CH3.CO.CH3.  Their  esters  are,  however,  quite  stable, 
and  are  employed  in  many  syntheses.  The  P  acids  bear  the  same 
relation  to  acetic  acid  that  the  a  acids  do  to  formic  acid:  (CH3.CO).- 
CH2.COOH.     . 

Aceto-acetic  Acid — CH3.CO.CH2.COOH — may  be  obtained  as  a 
thick,  strongly  acid  liquid  by  saponification  of  its  esters.  Heat  de- 
composes it  into  acetone  and  carbon  dioxid,  according  to  the  equation 
driven  above.  Aceto-acetic  acid  accompanies  ^-oxybutyric  acid  and 
acetone  in  the  urine  in  diabetes.     (See  Aceto-aoetic  ester,  p.  360). 

Lacvulinic  Acid— fi-aceiylpropionic  cicid— CH3.CO.CH2.CH2.COOII 
— is  obtained,  along  with  formic  acid,  by  boiling  fructose,  or  cane- 
sugar,  with  dilute  H2SO4,  and  also  similarly  from  pseudomucin :  CH2- 
OH.CO.(CHOH)3.CH20H  =  CH3.CO.CH2.CH2.COOH  +  H.COOH  + 
H2O.  It  crystallizes  in  plates,  f.  p.  33.5°,  hygroscopic,  very  soluble  in 
water,  alcohol  and  ether.    By  reduction  it  yields  normal  valerianic  acid. 

Diketone-monocarboxylic  acids,  such  as  CH3.CO.CO.COOH,  are 
also  known,  as  well  as  triketone  monocarboxylic  acids,  and  mono-, 
di-,  and  triketone  dicarboxylic  acids.  Aldehyde-ketone  acids,  such 
as  CHO.CO.COOH,  also  exist. 

MesoxaUc  Acid— Dioxymalonic  acid— Ho)>^<(^^g— is  the  mono- 
ketone- dicarboxylic  acid,  COOH.CO.COOH,  combined  with  water  in 
the  same  manner  as  chloral  hydrate  and  glyoxylic  acid  (see  above  and 
pp.  304,  346).  Esters  are  known  corresponding  to  both  forms: 
oxymalonic  esters.  CO:  (COO. 02X15)2,5  and  dioxymalonic  esters, 
C(0H)2:  (COO. 02115)2.     Mesoxalic  acid  is  obtained  by  the  action  of 


348  MANUAL    OF    CHEMISTRY 

boiling  barium  hydroxid  upon  dibromomalonic  acid:  C00H.CBr2.- 
COOH+Ba(OH)2=COOH.C(OH)2.COOH+BaBr2,  or  upon  aUoxan 
(mesoxalylurea).  It  crystallizes  in  prisms,  very  soluble  in  water, 
fusible  at  115°  (239°  P.)  On  evaporation  of  its  aqueous  solution  it 
decomposes  into  carbon  monoxid,  water  and  oxalic  acid;  at  higher 
temperatures  it  yields  carbon  dioxid  and  glyoxylic  acid. 

OXYALDBHYDB  AND  OXYKBTONB  ACIDS. 

These  acids  contain  alcoholic  groups,  CH2OH,  CHOH,  or  COH  in 
addition  to  carboxyl  and  either  the  aldehyde  or  ketone  group,  CHO 
or  CO. 

Glucuronic  Acid  — CHO.  (CHOH) 4. COOH  — is  a  derivative  of 
glucose:  CHO.(CHOH)4.CH20H.  It  is  a  syrup  which  passes  into  a 
crystalline  lactone  on  warming.  It  occurs  in  the  urine  in  small  quan- 
tity normally,  in  combination  with  phenol,  skatole  and  indole,  and 
with  camphors,  chloral  and  other  substances  when  these  are  present. 

SIMPLB   BTHERS. 

These  substances  have  been  referred  to  (p.  282)  as  the  simplest 
products  of  oxidation  of  the  hydrocarbons.  The  term  ether  was  for- 
merly applied  to  any  substance  produced  by  the  action  of  an  acid 
upon  an  alcohol.  Such  products  belong,  however,  to  two  distinct 
classes: 

(1)  The  simple  ethers,  or  ethers,  which  are  the  oxids  of  the  hy- 
drocarbon radicals,  and  the  counterparts  of  the  metallic  oxids,  bearing^ 
the  same  relation  to  the  alcohols  that  the  metallic  oxids  do  to  their 
hydroxids: 


CH3.CH2\o 
CH3.CH2/" 

CHa.CHzXo 

Ethyl  oxld. 

Ethyl  hydroxid. 

Potassium 

Potatslam 

(Ether.) 

(Alcohol). 

oxid. 

hydroxid. 

(2)  The  compound  ethers,  now  called  esters,  which  are  the 
products  of  the  reaction  between  an  acid  and  the  alcohol,  the  latter 
behaving  as  a  basic  hydroxid  (p.  284).  They  are  the  counterparts  of 
the  metallic  salts: 

CH3.CH2.0\gQ  CH3.CH2.0\g()  KO\^q  KO\q^ 

MoDoethylie  Diethylio  Monopotasaie  Dipotasiie 

sulfate-  anlfate.  snlfate.  ■tdfate. 

(Ester-aeid.)  (Neutral  ester.)  (Acid  salt.)  (Neutral  salt.) 

Mixed  ethers  differ  from  simple  ethers  in  that  they  contain  differ- 
ent, in  place  of  similar,  alkyls,  as  methyl-ethyl  oxid:  CH3.O.CH2.- 
CH3. 


i 


SIMPLE    ETHERS 


349 


Simple  and  mixed  ethers  are  formed:  (1)  Bv  interaftioti  ijf  the 
aleobols  and  alkyl -sulfuric  acide.  Thus  methyl -snlfiirie  aeid  und 
ethylic  alcohol  form  methyl-etLyl  oxid:  S02\oh  "^H-CsHs.O.H^ 
CaH5.O.0H3+S02i(OH)2.  (2)  By  the  aetioii  of  alkyl  halidn  upou 
sodium  aleoholates:  CH,.Cl+C2H5.0,Na=NaCl+C2H5.0.CII..  (a) 
By  the  aetiou  of  silver  oxid  upon  alkyl  halids;   2C2H5l+Agf20— 2AgI 

+  0(1%H5)2. 

Methyl  oxid — CHa.O.CHa— 46  —  isomerie  with  ethyl  alcohol,  is 
obtaiDed  by  the  aetion  of  silver  oxid  upou  raetbyl  iodid.  or  by  the 
action  of  H^SO^  and  borie  aeid  upon  methyl  aleohol.  It  is  a  colorless 
^as,  has  au  ethereal  odor,  bums  with  a  pale  tlame,  liquefies  at  — 36° 
(—32,8"*  P.),  and  boils  at  —21°  (—5.8°  P.),  is  soluble  in  H2O, 
HsSOj  and  ethylie  aleohoL 

Ethyl  Oxid — Ethtjlic  ether— 'Sulfuric  ether — ^^Jther  foriier  (U.S.); 
^(her  purus  (Br J — C2H5.0.Ci!H5.^ — In  the  mauufaeture  of  ether  a 
mixture  is  made  of  5  pts.  of  90%  alcohol  and  9  pts.  of  eonceutrated 
Hs^SOi,  in  a  vessel  snrrouuded  by  cold  water,  This  mixture  is  iutro- 
dueed  into  a  retort,  into  which  a  slow  stream  of  alcohol  is  allowed  to 
flow  during  tlie  remainder  of  the  process.  Fleat,  so  regulated  as  not 
to  exceed  HO'^  (284'^  P.)»  is  then  applied  to  the  retort,  which  is  eon- 
Dected  with  a  well -cooled  condenser,  and  contiuued  until  the  tempera- 
tare  rises  above  the  point  indicated.  The  distillate  contains  ether, 
alcohol,  water  and  dissolved  gases,  notably  8(>j.  It  is  shaken  with 
water  containing  potash  or  lime,  and  the  ether  decanted  off.  The 
product  is  "washed  ether /^  For  further  purification  it  is  treated  with 
calcium  chlorid,  or  recently  burnt  lime,  with  which  it  is  left  in  con- 
tact for  24  hours,  and  from  which  it  is  then  distilled. 

In  the  conversion  of  alcohol  into  ether,  sulfoviuic  or  ethyl -sulfuric 
acid  behaves  as  a  ^-contact  substance'*  and  serves  to  carry  an  ethyl 
radical  from  one  alcohol  molecule  to  another,  with  formation  of  water 
and  regeneration  of  sulfuric  acid.  In  the  first  stage  of  the  reaction 
ethyl-sulfuric  acid  is  formed  by  the  action  of  H12SO4  upon  alcohol, 
molecule  for  molecule:  H2804+C2H5.OU =11204- C2n5.H804.  The 
ethyl-sulfnrie  acid  then  reacts  with  another  nu>lecule  of  alcohol, 
aecording  to  the  general  reaction  (1)  for  the  formation  of  ethers,  to 
form  ether  and  sulfuric  acid:  C2n5.HB04  + OjIls^OH  =  H2SO1  + 
(C2H5)20.  It  would  seem,  therefore,  that  a  given  quantity  of  H28O4 
4K>tild  convert  an  unlimited  amount  of  ah'ohol  into  ether*  But  the 
gradual  accumulation  of  the  H^jO  formed  in  the  first  stage  of  the 
reaction,  and  the  ojcurrence  of  secondary  reactions  in  practice  limit 
the  amount  of  ether  produced  to  about  four  or  five  times  the  bulk  of 
meid  used. 

Ether  is  a  colorless  liquid  ;  has  a  sharp,  burning  taste,  and  a  pe- 
culiar, tenacious  odor,  characterized  as  ethereal.      8p.  gr.  0.723  at 


350  MANUAL    OP    CHEMISTRY 

12.5°  (54.5°  P.);  it  boils  at  34.5°  (94.1°  F.).  Its  tension  of  vapor 
is  very  great,  especially  at  high  temperatures;  and  it  is  exceedingly 
volatile.  Water  dissolves  one-ninth  its  weight  of  ether.  Ethylie 
and  methylic  alcohols  are  miscible  with  it  in  all  proportions.  Ether 
is  an  excellent  solvent  of  many  substances  not  soluble  in  water  and 
alcohol.  The  resins  and  fats  are  readily  soluble  in  ether.  The  salts 
of  the  alkaloids  and  many  vegetable  coloring  matters  are  soluble  in 
alcohol  and  water,  but  insoluble  in  ether,  while  the  free  alkaloids  are 
for  the  most  part  soluble  in  ether,  but  insoluble,  or  very  sparingly 
soluble,  in  water. 

Ether  is  highly  inflammable;  and  bums  with  a  luminous  flame. 
The  vapor  forms  with  air  a  violently  explosive  mixture.  It  is  denser 
than  air,  through  which  it  falls  and  diffuses  itself  to  a  great  dis- 
tance ;  caution  is  therefore  required  in  handling  ether  in  a  locality  in 
which  there  is  a  light  or  fire,  especially  if  the  fire  be  near  the  floor. 

Pure  ether  is  neutral  in  reaction.  H2SO4  mixes  with  it,  with 
elevation  of  temperature,  and  formation  of  sulfovinic  acid.  With  sul- 
furic anhydrid  it  forms  ethyl  sulfate.  HNO2,  aided  by  heat,  oxidizes  it 
to  carbon  dioxid  and  acetic  and  oxalic  acids.  Ether,  saturated  with 
HCl  and  distilled,  yields  ethyl  chlorid.  CI,  in  the  presence  of  H2O, 
oxidizes  it,  with  formation  of  aldehyde,  acetic  acid,  and  chloral. 
In  the  absence  of  H2O,  however,  a  series  of  products  of  substitution 
are  produced,  in  which  2,  4,  and  10  atoms  of  H  are  replaced  by  a  cor- 
responding number  of  atoms  of  CI.  These  substances  in  turn,  by 
substitution  of  alcoholic  radicals,  or  of  atoms  of  elements,  for  atoms 
of  CI,  give  rise  to  other  derivatives. 

Alkylen  Oxids — Ethers  of  Glycols. — The  oxids  of  the  univalent 
hydrocarbon  radicals,  the  alkyls,  correspond  to  the  mouohydric  alco- 
hols; and  similarly  the  oxids  of  the  bivalent  hydrocarbon  radicals, 
whicli  latter  are  called  alkylens,  correspond  to  the  dihydric  alcohols, 
or  glycols.  Two  classes  of  these  ethers  are  known:  A.  Acyclic  alco- 
hol-ethers of  the  types:  CH20H.CH2.0.C2H5=glycol-ethyl  ether; 
C2H5.0.CH2.CH2.0.C2H5=glycol-diethyl  ether,  and  CH2OH.CH2.- 
O.CH2.CH20H=diethylene-glycol  ether;  and  B.  Cyclic  ethers  of 
several  types,  included  among  the  heterocyclic  compounds,  the  sim- 

CH2K 
plest  of  which  is:   Ethylene  Oxid — I     yO — which  is  prepared   by 

CHo 

the  action  of  caustic  potash  on  ethylene  ehlorhydrin  (p.  363):  CH2- 
0H.CH2C1+KH0=(CH2)20+KC1+H20.  It  is  a  volatile  liquid,  boils 
at  13.5^  (54.3°  F.),  is  neutral  in  reaction  and  mixes  with  water.  It 
unites  with  H2O  to  form  glycol,  and  with  HCl  to  regenerate  ethylene 
ehlorhydrin.    Nascent  H  converts  it  into  ethyl  alcohol. 

Two  classes  of  ethers  are  also  derivable  from  the  glycerols: 


ACID    ANHYDRIDS  351 

A.  Acyclic  ethers,  such  as  mono-,  di-  and  triethylins:   CH2OH.- 

CHOH.CH20(C2H8);  CH20H.CHO(C2H5).CH20(C2H5):   and  CH2O- 

(C3H6).CHO(G2H5).Gfi30(G2H5);    and    B.    Cyclic  ethers,  such   as 
CH3.GH.GHs 

glycerol  ether:  0     0    0,  and  glycid,  or  epichlorhydrin  alcohol: 

GH2.CH.CHs 
•  CHs 
0\  I  ,  corresponding  to  epichlorhydrin  (p.  364). 

CH .  CHsOH 


ACID   ANHYDRIDS. 

The  acyclic  ethers  of  the  glycols  and  glyceix)l8,  referred  to  above, 
are  properly  included  in  that  class  of  oxidation  products  of  the  paraf- 
fins derivable  from  the  hydrocarbons  by  both  interpolation  of  an  oxy- 
gen atom  between  two  hydrocarbon  groups  and  the  oxidation  of  one 
or  more  such  groups  (p.  282).  The  esters,  which  are  also  included  in 
the  same  class,  will  be  considered  later  (p.  358). 

Another  group  of  the  same  class  are  the  acid  anhydrids.  These 
substances  may  be  considered  as  being  derived  from  the  paraffins  by 
interpolation  of  an  oxygen  atom  symmetrically,  and  the  oxidation  of 
the  two  neighboring  GH2  groups  to  GO  groups.  Thus  acetic  anhydrid 
may  be  derived  from  normal  butane:  CH3.CO.O.CO.CH3  from 
CH8.CH2.CH2.CH3. 

The  acid  anhydrids  are  also  the  oxids  of  the  acid  radicals  (acidyls) ; 
and  bear  the  same  relation  to  the  acids  that  the  simple  ethers  bear  to 
the  alcohols: 

CH3.COOH  CH3.CH2OH  » 

Ae«tio  add.  Ethylie  alcohol. 

CHj.COXn  CHs.CHjX^ 

CH3.CO/"  CHa.CHj/^ 

Aeetie  anhydrid.  Ethylie  ether. 

The  acid  anhydrids  of  the  monobasic  acids  are  produced  by  the 
action  of  the  acidyl  chlorids  upon  anhydrous  salts:  C2H3O.OK+C2- 
H30.C1=(C2H30)20+KC1;  or  by  the  action  of  phosphorus  oxychlorid 
upon  the  alkali  salts  of  the  acids.  In  this  method  of  formation  the 
acidyl  chlorid  is  first  produced:  2C2H30.0K+POCl8=2C2H80.Cl+ 
POsE+ECl;  and  this  acts  upon  an  excess  of  the  salt  according  to 
the  above  equation.   Formic  acid  produces  no  anhydrid. 

Acetic  Anhydrid-— (C2H80)20 — is  a  pungent  liquid  which  boils 
at  137°  (278.6°  P.).  It  is  formed  by  the  general  methods  and 
also  by  heating  lead  acetate  with  carbon  disulfid  at  165°  (329°  P.). 
It  serves  for  the  introduction  of  the  radical  acetyl  into  other 
molecules. 


352  MANUAL    OP    CHEMISTRY 

Mixed  anhydrids  of  the  fatty  acids,  corresponding  to  the  mixed 
€thers,  and  containing  two  different  acidyls,  are  also  known,  but  on 
heating  are  split  into  two  anhydrids:  2CH3.CH2.CO.O.CO.CH3= 
(CH3.CH2.CO)20  +(CH3.CO)20. 

Acid  peroxids  of  the  acetic  series,  containing  two  interpolated 
oxygen  atoms,  such  as  CH3.CO.O.O.CO.CH3,  exist,  but  are  very 
unstable. 

Anhydrids  of  oxalic  and  malonic  acids  are  unknown,  but  succinic 

CH2.COK 
acid  readily  forms  an  anhydrid :    I  J)0.    The  oxyacids  on  loss  of 

CH2.CO 

H2O  tend  to  form  lactids  or  lactones  rather  than  anhydrids. 


XaDYL   HALIDS. 

These  compounds,  also  known  as  halid  anhydrids,  are  the  halo- 
gen compounds  of  the  acidyls.  They  are  produced:  (1)  by  the  action 
of  the  phosphorus  halids  upon  the  acids  or  their  salts:  SCHs.COOH 
+PCl3=3CH3.COCl  +  P03H3;  or  2CH3.COOK+POCl3=2CH8.COCl 
+PO3K+KCI;  orCH8.COOH+PCl5=CH3.COCl+POCl3+HCl;  (2) 
by  the  action  of  phosgene  upon  the  acids,  or  their  salts:  COCk+CHs.- 
COOH=CH3.CO.Cl+C02+HCl;  (3)  by  the  action  of  phosphorus 
pentoxidupon  the  acids  in  presence  of  hydrochloric  acid:  3CH3.COOH 
+3HC1+P205=3CH3.C0.C1+2P04H3;  or,  (4)  by  the  action  of 
chlorin  upon  the  aldehydes:  C]2+CH3.C0.H=CH3.C0.C1+HC1. 

Acetyl  Chlorid — CH3.CO.CI — is  a  colorless,  pungent  liquid,  which 
boils  at  55°  (131°  F.).  It  is  decomposed  by  water  with  formation  of 
acetic  and  hydrochloric  acids.  With  acetic  acid  it  forms  acetic  anhy- 
drid.   It  is  used  to  produce  acetyl  derivatives. 

OXIDS   OP    CARBON. 

The  two  oxids  of  carbon  are  also  anhydrids  in  that  they  combine 
with  water  to  produce  acids,  or,  what  amounts  to  the  same  thing, 
with  KHO  to  form  the  K  salts,  thus  : 

CO  4-  KHO  =  H.COOK 

Carbon  Potasiinm  Potassium 

monoxld.  hydroxid.  formate. 

CO2  -h  KHO  =  0:C<^^| 

Carbon  Potassium  Monopotastia 

dio^d.  hydroxid.  carbonate. 

Carbon  Monoxid — Carbonous  oxid — Carbonic  oxid — CO — 28 — is 
formed:    (1)  By  burning  C  with  a  limited  supply  of  air.     (2)   By 


OXIDS    OF    CARBON 


353 


mig  dry  carbon   dioxitl  over  red-hot   t:lian;oal,     {3)  By  heating 
"eialie  acid  with  stilfiiric  aeid:    CiOilli^HiO+CO+CO-i;    and  pass- 
ing the  gas  throngh  sodiutn  liydroxid  to  separate  COj,    (4)  By  b<!ating 
potassium  ferrocyanid  with  112804. 

It  is  a  colorless,  tasteless  gns:  sp.  gr.  0.9678A;  very  spftringly 
soluble  ill  IhO  and  in  alcohol.  It  burns  in  air  with  a  blue  flame  to 
CO'i*  and  it  fornix!  explosive  mixtures  with  air  and  oxygen.  It  is  a 
valuable  reducing  agent,  and  is  used  for  the  reduction  of  metallic 
osids  at  a  red  heat,  Aramoniaeal  solutions  of  the  cuprous  salts 
absorb  it  readily.  Being  non-satnrated,  it  unites  readily  w*ith  O  to 
form  CO2,  and  with  CI  to  form  COCI2,  the  latter  a  colorless,  snffo- 
cating  gas,  known  as  phosgene,  or  carbonyl  chlorid,  which  is  of 
service  in  the  formation  of  acid  ehlorids  and  anbydrids  (p.  352)  and 
in  a  variety  of  other  syntheses. 

Toxicology, — Carbon  niouoxid  is  an  exceedingly  poisonous  gas, 
and  is  the  chief  toxic  constituerjt  of  the  gases  given  off  from  bhist* 
farnaces,  from  defective  flues,  from  open  coal  or  charcoal  fires  and  of 
illaminating  gas. 

Poisoning  by  CO   may  occur  in  several  ways.    By  inhalation  of 
the  gases  discharged  from  blast- furnaces  and  from  copper- furnaces, 
rhe  former  containing  25  to  32  per  cent  and  the  latter  13  to  19  per 
cent,  of  CO.     By  the  fumes  given  off  from  charcoal  burned  in  a  con- 
fined space,  which  consists  of  a  mixture  of  the  two  oxids  of  carbon, 
the  dioxid  predominating  largely,* especially  when  the  combustion  is 
most  active.      The  following  is  the  composition  of  an  atmosphere 
produced  by  burning  charcoal  in  a  confined  space,  and  which  proved 
rapidly  fatal  to  a  dog:  oxygen,  19  J9;  nitrogen,  76.62^  carbon  dioxid, 
4<61;   carbon  monoxid,  0,54;   marsh-gas,  0.(>4.     Obviously  the  dele- 
terious effects  of  charcoal-fumes  are  more  rapidly  fatal  in  proportion 
as  the  combustion  is  imperfect  and  the  room  small  and  ill- ventilated. 
A  fruitful  source  of  CO  poisoning,  sometimes  fatal,  but  more  fre- 
quently producing  languor,  headache  and  debility,  is  to  be  found  in 
the  stoves,  furnaces,  etc.,  used  in  heating  our  dwellings  and  other 
buildinge,  especially  ivhen  the  fuel  is  anthracite  coal*     This  fuel  pro- 
duces in  its  combustion,  when  the  air  supply  is  not  abundant,  consid- 
erable quantities  of  CO,  to  which  a  further  addition  may  be  made  by 
the  reduction  of  the  dioxid,  also  formed,  in  passing  over  red-hot  iron. 
Of  late  years  cases  of  fatal  poisoning  by  illuminating  gas  are  of 
very  frequent  occurrence.    The  most  actively  poisonous    ingredient  of 
illuminating  gas   is  CO,   which  exists  in  ordinary  coal-gas   in    the 
proportion  of  4  to  7.5  per  cent,  and  in  water-gas,  made  by  decom- 
poBUXU  superheated  steam  by  passage  over  red-hot  coke,  and  sub- 
sequent charging  with  vapor  of  hydrocarbons,  in  the  large  proportion 
of  30-35  per  cent* 


23 


i 


354 


MANtTAL   OF    CnEMTSTRY 


I 


The  method  iu  which  CO  produces  its  fatal  effects  is  by  form  in  gr 
With  the  blood-coloring  matter  a  compound  which  is  more  stable  than 
oxyht^moglobin,  and  thus  causing  asphyxia  by  destroying  the  power 
of  the  blood  corpuscles  of  carr>4ng  0  from  the  air  to  the  tissnes.B 
This  compound  of  CO  and  hirmoglobin  is  quite  stable,  and  hence  the 
symptoms  of  this  form  of  poisoning  are  very  persistent,  lasting  until 
the  place  of  the  eoloring-matter  thus  rendered  useless  is  supplied  byB 
new  formation.     The  prognosis  is  very  inifavorable  when  the  amount 
of  the  gas  inhaled  has  been  at  all  considerable,  the  treatment  usu* 
ally  follovs^ed,  f.  f.,  artificial  respiration  and  inlialation  of  O,  restoring 
the  altered  coloring  matter  very  slowly.     There  would  seem  to  be  no 
form  of  poisoning  in   whieh   transfusion  of  blood   is   more  directly 
iridieated  than  in  that  by  CO,  but  it  has  been  found  to  be  detrimental  J 
rather  than  beneficial,  ™ 

Detection  after  death* — The  blood  of  those  asphyxiated  by  CO  is 
persistently  bright-red  in  color.  When  suitably  diluted  and  examined 
with  the  speetroseope,  it  presents  an  absorption  spectrum  (No.  6* 
fig,  43,  p.  661)  of  two  bands  similar  to  that  of  oxyheeraoglobin  (No, 
3,  ^g.  43^,  but  in  which  the  two  bands  are  more  equal  and  somewhat 
nearer  the  violet  end  of  the  spectrum.  Owing  to  the  greater  stability 
of  the  CO  compound,  its  spectrnni  may  be  readily  distinguished  from 
that  of  the  0  ccmipound  by  the  addition  of  a  reducing  agent  (an  am- 
moDiaeal  solution  of  ferrous  tartrate),  which  changes  the  spectrum 
of  oxyhfemoglobiu  to  the  single-babd  spectrum  of  haMiioglobin  (No. 
1,  fig.  43) »  while  that  of  the  CO  compouod  remains  unaltered,  or^ 
only  fades  partially.  ■ 

If  a  solution  of  caustic  soda  of  sp.  gr.  1.3  be  added  to  normal 
blood,  a  black,  slimy  mass  is  formed,  whicli,  when   spread  upon  a 
white  plate,  has  a  greenish-brown  color.     The  same  reagent  added  to 
blood  altered  by  CO  forms  a  firmly  clotted  mass,  which  in  thin  layersn 
upon  a  white  surface  is  bright  red  in  cfilor.  | 

A  piece  of  gun-cotton  upon  which  platinum-black  has  been  dusted 
fires  in  air  containing  2.5  iu  1,000  of  CO. 

Carbon  Dioxid — Carbonic  anhydrid — ^Carbonic  acid  gas — COa 
44 — ^is  obtained:  (1)   By  burning  C  in  air  or  O.    (2)  By  decomposing 
a  carbonate  (nmrblc^^^CaCOa)  by  a  mineral  acid  (HCl  diluted  with  aii^ 
equal  volume  of  H2O).  ■ 

At  ordinary  temperatures  and  pressures  it  is  a  colorless,  suffo* 
eating  gas;  has  an  acidulous  taste;  sp.  gr,  1.529  A;  soluble  in  ai» 
equal  volume  of  H2O  at  the  ordinary  pressure,  much  more  soluble  »^ 
the  pressure  increases.  Soda  water  is  a  solution  of  carbonic  acid  i'^ 
H2O  under  increased  pressure.  When  compressed  to  the  extent  of 
38  atmospheres  at  0°  (32°  F);  50  atm.  at  15°  (59°  F.);  or  73  atm- 
at  30°  (86°  F.)  it  forms  a  transparent,  mobile  liquid,  by  whose  evapo* 


OXIDS    OP    CARBON  355 

rati- on.  when  the  pressure  is  relieved,  sufficient  cold  is  produced  to 
goLm^ify  a  portion  into  a  snow-like  mass,  which,  by  spontaneous 
eva.;M)oration  in  air,  produces  a  temperature  of  — 90°  ( — 130°  F.). 

Oarbon  dioxid  neither  bums  nor  does   it  support  combustion. 

\ri:a€n  heated  to  1,300°  (2,370°  F.),  it  is  dissociated  into  CO  and  O. 

A  similar  decomposition  is  brought  about  by  the  passage  through  it 

of      electric  sparks.     When   heated  with  H   it  yields   CO  and  H2O, 

Wl3en  K,  Na,  or  Mg  is  heated  in  an  atmosphere  of  CO2,  the  gas  is- 

deocmposed  with  formation  of  a  carbonate  and  separation  of  carbon. 

WTaen  caused  to  pass  through  solutions  of  the  hydroxids  of  Na,  K, 

C»,  or  Ba,  it  is  absorbed,  with  formation  of  the  carbonates  of  those 

metals,  which,  in  the  case  of  the  last  two,  are  deposited  as  white 

precipitates.      Solution  of  potash  is  frequently  used  in  analysis  to 

absorb  CO2,  and  lime  and  baryta  water  as  tests  for  its  presence.     The 

hydroxids  mentioned  also  absorb  CO2  from  moist  air. 

Atmospheric  Carbon  Dioxid. — Carbon  dioxid  exists  in  free  country 
air  in  the  proportion  of  about  four  parts  in  10,000.  Its  sources  are 
froM:  (1)  Respiration.  Expired  air  contains  about  4.5  per  cent  CO2. 
(2)  Combustion  of  fuel,  illuminating  gas,  etc.  A  burner  consuming 
three  cubic  feet  of  illuminating  gas  per  hour  produces  as  much  CO2 
as  is  formed  by  the  respiration  of  seven  human  beings.  In  a  confined 
space  respiration  and  combustion  vitiate  the  air  in  two  ways:  by  addi- 
tion of  carbon  dioxid  and  by  removal  of  oxygen,  as  the  CO2  is  produced 
*t  the  expense  of  atmospheric  oxygen.  By  the  other  methods  of  its 
^Hgin  it  is  merely  added  to  the  air,  whose  oxygen -content  remains 
nearly  unaltered.  (3)  Fermentation.  For  every  liter  of  alcohol  pro- 
^Qced  384  liters  of  CO2  are  added  to  the  air.  (4)  Tellural  sources, 
such  as  volcanic  fissures,  volcanoes,  spring  waters.  (5)  Manufactur- 
^^S  operations,  such  as  lime-burning,  cement  and  brick- making,  iron 
furnaces,  etc.  (6)  In  coal  mines  the  after-damp  contains  a  volume  of 
^^  equal  to  that  of  the* fire-damp  exploded. 

Notwithstanding  the  large  amounts  of  CO2  discharged  into  the 
^^inosphere  from  these  several  sources,  and  it  is  estimated  that  the 
^paount  is  sufficient  to  double  the  atmospheric  CO2- content  in  about 
^^Shty  years,  no  increase  in  the  normal  proportion  of  CO2  in  free  air 
*^^  been  observed.  This  is  due  to  the  constant  removal  of  CO2  from 
tl^e  air  by  plants,  the  green  pigment  of  which,  chlorophyll,  decomposes 
^^  under  the  influence  of  sunlight,  retaining  the  carbon  in  organic 
^^mbination,  and  returning  oxygen  to  the  air. 

Action  on  the  Economy. — An  animal  introduced  into  an  atmos- 
P'liere  of  pure  CO2  dies  almost  instantly,  and  without  entrance  of  the 
Kas  into  the  lungs,  death  resulting  from  spasm  of  the  glottis,  and 
^usequent  apnoea. 

When  the  proportion  of  0  is  not  diminished,  the  poisonous  action 


356 


MANUAL    OF    CHEMISTRY 


of  CO2  is  not  as  manifest,  in  equal  quantities,  as  when  the  air  is 
poorer  in  oxygen.  An  anifnal  will  die  rapidly  in  an  atraospliere  com- 
posed of  21  per  cent.  O,  59  per  cent.  N,  and  20  per  cent.  CO2  by  vol- 
ume; but  will  live  for  several  hours  in  an  atraosphere  whose  compo- 
sition is  40  per  eent.  O,  37  per  cent.  X.  23  per  cent.  CO2.  If  CO2  be 
added  to  normal  air,  of  coni-se  the  relative  quantity  of  O  is  slightly 
diminished,  while  its  absolute  quantity  remains  the  same.  This  is 
the  condition  of  affairs  existing  in  nature  wlien  the  gas  is  discharged 
into  the  nir.  Under  these  circumstances  an  addition  of  10-15  per  cent, 
of  CO2  renders  an  air  rapidly  poisonous,  and  one  of  5-S  per  cent,  will 
cause  the  death  of  small  animals  more  slowly.  Even  a  less  pro- 
portion than  this  may  become  fatal  to  an  individual  not  habituated. 

When  present  in  large  proportion,  CO2  prodnees  immediate  loss  of 
muscular  power,  and  death  without  a  struggle;  when  more  dilute,  a 
sense  of  irritation  of  the  larynx,  drowsiness,  pain  in  the  head,  giddi- 
ness, gradual  loss  of  muscular  power,  and  death  in  coma. 

If  the  CO2  present  in  air  be  produced  by  resinration,  or  com- 
bustion, the  proportion  of  O  is  at  the  same  time  diminished,  and 
much  smaller  absolute  and  relative  amounts  of  the  poisonous  gas  will 
produce  the  effects  mentioned  above.  Thns»  an  atmosphere  con- 
taining in  volumes  19.75  per  cent.  0,  74.25  per  cent.  N,  6  per  cent. 
CO2,  is  much  more  rapidly  fatal  than  one  composed  of  21  per  cent. 
O,  59  per  cent.  N,  20  per  cent.  CO2.  With  a  corresponding  redue- 
tion  of  0,  5  per  cent,  of  CO2  renders  an  air  sufficiently  poisonous  to 
destroy  life;  2  per  cent,  produces  severe  suffering;  1  per  cent,  causes 
great  discomfort,  while  0.1  per  cent.,  or  even  less,  is  recognized  by  a 
sense  of  closeness. 

The  treatment  in  all  cases  of  poisoning  by  COt  consists  in  the 
inhalation  of  pure  air  (to  which  an  excess  of  O  may  be  added),  aided, 
if  necessary,  l)y  artificial  respiration,  the  cold  douche,  galvanism,  and 
friction. 

Detection  of  Carbon  Dioxid  and  Analysis  of  Confined  Air. — ^Car- 
bon  dioxid,  or  air  containing  it,  causes  a  white  precipitate  when 
caused  to  bubble  through  lime  or  baryta  water.  Normal  air  contains 
enough  of  the  gas  to  form  a  scum  upon  the  surface  of  these  solutions 
when  exposed  to  it. 

It  was  at  one  time  supposed  that  air  in  which  a  candle  continued 
to  bum  was  also  capable  of  maintaining  respiration.  This  is,  how- 
ever»  by  no  means  necessarily  true.  A  candle  introduced  into  an 
atmosphere  in  which  the  normal  proportion  of  0  is  contained,  burns 
readily  in  the  presence  of  8  per  cent,  of  CO-j;  is  perceptibly  dulled  by 
10  percent.;  is  usually  extinguished  with  13  percent.;  always  ex- 
tinguished with  16  per  cent.  Its  extinction  is  caused  by  a  less  pro- 
portion of  CO2,  4  per  cent.,  if  the  quantity  of  O  be  at  the  same  time 


■ 


OXIDS    OF    CAKBON 


357 


liminished.  Moreover;  a  contaminated  atmosphere  may  not  eontaiu 
enough  CO2  to  extinguish ^  or  perceptib].y  dim  the  flame  of  a  caudle, 
and  at  the  same  time  contain  enough  of  the  monoxid  to  render  it 
fatally  poisonous  if  inhaled. 

The  presence  of  CO2  in  a  gaseous  mixture  is  determined  by  its 
absorption  by  a  solution  of  potash;  its  quantity  either  by  measuring 
the  diminution  in  bulk  of  the  gas,  or  by  noting  the  increase  in  weight 
of  an  alkaline  solution. 

To  determine  the  proportions  of  the  various  gases  present  in  air 
the  apparatus  shown  in  Fig,  42  is  used.  A  is  an  aspirator  of  knowii 
capacity,  filled  with  water  at  the  beginning  of  the  operation.  It  con- 
nects by  a  flexible  tube  from  its  upper  part  with  an  absorbing  appa- 
ratos  consisting  of  a,  a  U*shaped  tube  containing  fragments  of 
pmnice -stone,  moistened  with  H2SO1;  by  the  increase  in  weight  of 
this  tube  the  weight  of  watery  vapor  in  the  volume  of  air  drawn 
through  by  the  aspirator  is  determined;  h,  a  Liebig^s  bulb  filled  with 
a  solution  of  potash;  c,  a  U-tuhe  filled  with  fragments  of  pumice 
moistened  with  HoSO*;  h  and  e  are  weighed  together  and  their  in- 
crease in  weight  is  the  weight  of  CO2  in  the  volume  of  air  operated 


uu*  Every  gram  of  increase  in  weight  represents  0.50G0T  litre,  or 
31.60356  cubic  inches;  £?  is  a  tube  of  diflicultly  fusible  glass,  filled 
with  black  oxid  of  copper  and  heated  to  redness;  e  is  a  U-tube  filled 
with  pumice  moistened  with  H28O4;  its  increase  in  weight  represents 
H*0  obtained  from  decomposition  of  CH4.  Every  gram  of  increase 
in  weight  of  e  represents  0.444  gram,  or  0.621  litre,  or  38.781  cubic 
inches  of  niarsh-gas;  /  and  g  are  similar  to  b  and  e,  and  their  increase 
IQ  weight  represents  CO2  formed  by  oxidation  of  CO  and  Clh  in  d. 


358 


MANUAL    OP    CHEMISTRY 


From  this  the  amount  of  CO  is  thus  calculated:  First,  2.75  gramn 
are  deducted  from  the  increase  of  weight  of  /  and  g  for  each  gram  of 
CHi  found  by  e;  of  the  remainder,  every  gram  repi*esents  0.6364 
gram,  or  0.5085  litre,  or  31.755  cubic  inches  of  CO.  The  air  is 
drawn  through  the  apparatus  by  opening  the  stopcock  of  A  to  such 
an  extent  that  about  thirty  bubbles  a  minute  pass  through  5. 

As  the  proportion  of  CO2  in  air  is  determinable  readily  and 
accurately,  its  determination  in  a  confined  air  is  depended  upon  to 
judge  of  the  respirability  of  the  air  and  the  degree  of  perfection  of 
the  methods  of  ventilation  used.  For  these  purposes  an  air  is  con- 
demned as  vitiated  if  it  contain  more  than  six  parts  in  10,000  of  COs. 


ESTERS— COMPOUND  ETHERS. 


As  the  alcohols  resemble  the  mineral  bases,  and  the  organic  acids 
resemble  those  of  mineral  origin,  so  the  esters  are  similar  in  constitu- 
tion to  the  salts,  being  formed  by  the  double  decomposition  of  an  alco- 
hol with  an  acid,  mineral  or  organic,  as  a  salt  is  formed  by  doable 
decomposition  of  an  acid  and  a  mineral  base,  the  radical  playing  the 
part  of  an  atom  of  corresponding  valence  : 


PotMsium  hydxozid. 


(NCMJO 
Nitric  acid. 


(C2H5)' 
H 

Bthjrl  hydroxid 
(alcohol). 


}" 


5i}o    - 


(NO2) 

H 
Nitric  Mid 


Water. 

Water. 


(N0^1}0 
PotMiinm  nitraf. 

(NO,n^ 

Ethyl  nitrate 
(nitric  ether). 


Therefore  the  esters  are  substances  derived  from  acids  by  partial  or 
complete  substitution  of  an  alkyl  or  alkyls  for  the  basic  hydrogen  of 
the  acid. 

Some  of  the  esters  still  contain  a  portion  of  the  acid  hydrog^en 
which,  being  replaceable  by  another  radical  or  by  a  metal,  commu- 
.nicates  acid  qualities  to  the  substance,  which  is  at  the  same  time  an 
ester  and  a  true  acid.  Such  esters  are  the  counter -parts  of  the  acid 
salts.  Or  di-  and  polyhydric  alcohols,  in  combining  with  acids  of 
inferior  basicity,  may  form  esters  which  still  retain  alcoholic  hydro- 
xyls,  and  which  are,  therefore,  alcohol-esters. 


ESTERS    OP    THE    MONOHYDRIC    ALCOHOLS. 


These  esters  are  produced: 

(1)  By  the  action  of  the  acid  upon  the  alcohol: 


H2SO4+CHS.CH2- 


ESTERS -COMPOUND    ETHERS 


359 


OH=CH3,CH2,HS04+HnO;  or  H2gOi+2CH3.CH20H=(CH3.CH3)r 
SO4+2H2O. 

(2)  By  the  action  of  the  correspoiidiug  haloid  esters  upon  the 
silver  salt  of  the  acid  :  AgX03+C2H5l=AgI+C2H5.NOx. 

(3) By  the  action  of  the  aeidyl  elilorida  upon  the  sodium  deriva- 
tives of  the  alcohols,  atid  in  some  instanees  upon  the  alcohols  them- 
selves :  CsHiO .01+  C2H5.0.Na=NaCl+ C2H:v02.C2H5. 

All  esters  are  decomposed  into  aeid  and  alcohol  by  the  action  of 
water  at  hi^h  temperatures,  or  of  caustic  potash  or  soda  :  (U2H5)N03 
+KHO=KN03+i2HftHO. 

As  this  deeoraposition  is  analogous  t-o  that  utilized  in  the  manu- 
facture of  soap  (p.  366),  it  is  known  as  saponification,  and  whenever 
an  e^ter  is  so  decomposed  it  is  said  to  be  saponified-  When  the  de- 
composition is  effected  by  H2O  the  free  acid  and  the  alcohol  ai*e 
formed,  and  it  is  known  as  hydrolysis  (p*  116):  (C2H6)C2H302+ 
H2O=02H5.HO+H.C2HriO2.  This  reaction  is  reversible  and  therefore 
does  not  proceed  to  completion.  Startiiij?  with  the  ester  it  is  saponi- 
fied according  to  the  equation  until  equilibrium  is  estahlished.  but 
starting  with  alcohol  and  acid  the  reaction  prot^eeds  according  to  the 
equation  read  from  right  to  left  until  the  same  condition  is  reached. 

Ethyl   NitrsLtc— Nitric   t/A^r— q%*; }0— S)L— A  colorless  liquid; 

has  a  sweet  taste  and  bitter  after -taste;  sp.  gr.  1.112  at  17°  (62.6^ 
F.);  boils  at  85*^  (185*^  F,);  gives  off  explosive  vapors.  Prepared 
by  distilling  a  mixture  of  HNO3  and  ^^2HftO  in  the  presence  of  urea. 

Ethyl  UitritG— Nitrons  ethfr—Q,^^^} 0—75— is  prepared  by  di- 
recting nitrous  fumes  into  alcohol,  contained  in  a  retort  connected 
with  a  well -cooled  receiver. 

It  is  a  yellowish  liquid;  has  an  apple -like  odor,  and  a  sbarp, 
sweetish  taste:  sp,  gr,  0,947;  boils  at  18"^  (64.4°  F.);  gives  off  in- 
flammable vapor;  very  sparingly  soluble  in  H2O;  readily  soluble  in 
alcohol  and  ether.    It  is  decomposed  by  warm  H^'O  and  by  alkalies. 

Ethyl  Sulfates— (C2Hfi)nS04=M//y/  snlfuric  or  SHlfovinic  acid 
and  {C-lW-SOA—Ethtji  std/ate— Sulfuric  ether. 

Moooethylic     sulfate  ~  Ethyl  •  sulfuric 
formed  as  an  intermediate  product  in  the  manufacture  of  ethylic  ether 
It  is  a  colorless,  syrupy,  highly  acid  liquid;   sp.  gr.  I.''il6;     soluble  in 
water  and  alcohol  in  all  proportions^  insoluble  in  ether. 

It  decomposes  slowly  at  ordinary  temperatures,  more  rapidly  when 
heated.  When  heated  with  alcohol,  it  yields  ethylic  ether  and  HiiSOi, 
When  heated  with  H'jO,  it  yields  alcoliol  and  H-jyOi.  It  fonuB  crys- 
talline salts,  kntjwu  as  sulfovinates,  or  sulfethylates,  one  of  which, 
sodium  sulfovinatc  (CjH,'i)NaSOi,  has  been  used  in  medicine.  It  is 
a  white,  deliqueBcent  solid;   soluble  in  H:>0. 


adrf  — ^'^^fio)sO.-i8 


360 


MANUAL    OF    CHEMISTRY 


Ethyl  Sulfate —  (C2H5)2S04 — the  true  sulfuric  ether,  is  obtaiued 
by  passing  vapor  of  SO3  iato  pure  ethylic  ether,  thoroughly  cooled. 
It  is  a  colorless,  oily  liquid;  has  a  sharp,  burning  taste,  and  the  odor 
of  peppermint;  sp,  gr,  1.120,  It  cannot  be  distilled  without  decom- 
position.    With  H2O  it  forms  sulfovinic  acid. 

Stilfurous  and  Hyposulfurous  Esters.^These  compounds  have 
recently  assumed  medical  interest  from  their  relationship  to  mer- 
captau,  sulfonal  and  a  number  of  aromatic  derivatives  used  as 
medicines. 

There  exist  two  isomeric  sulfurous  acids  (p,  144),,  both  of  which 
yield   neutral   esters,   but   only  one   of   which,    the   unsymmetrical, 


\on 


forms  acid  esters.    These  acid  esters  are  known  as  sulfonic 


acids.  (See  Aromatic  sulfonic  acids,  raercaptan,  sulfones,  sulfonal.) 
Diethyl  Sulfite— (C-iHfJ^SOa — is  produced  by  the  action  of  thionyl 
ehlorid  on  ahsolnte  alcohol :  SOCl2+2C2H5HO^S03(C2H5)2+2H(T 
It  is  a  colorless  liquid,  having  a  powerful  odor:  sp,  gr,  1.085,  boils 
at  161°  (321. 8"^  FJ,  H2O  decomposes  it  into  alcohol  and  sulfnrons 
acid. 

Ethyl   Sulfonic    Acid— S02<(o^*— is  formed  by  the   action   of 

ethyl  iodid  on  potassium  sulfite:  C2H5H-S03K2=C2H5.S020K+KL 
It  forms  salts  and  esters. 

Sulfinic    Acids— are    the    acid    esters    of    hyposulfurous    acid 

/FT 

SO\OH,  ^^^^^  ^^^  analogous  to  the  sulfonic  acids. 

Ethyl   Acetate  —  Acetic    ether  —  -ffither  aceticus  **^  ( U .    S . )  — 

C^H  J  0*^1^  obtained  by  distilling  a  mixture  of  sodium  acetate,  alco- 
hol and  H'iSOi;  or  by  passing  carbon  dioxid  through  an  alcoholic 
solution  of  potassium  acetate. 

It  is  a  colorless  liquid,  has  an  agreeable,  ethereal  odor:  boils  at 
74*"  (165.2°  F.) ;  sp.  gr.  0.92  at  IS""  (59''  FJ  ;  soluble  in  6  pts,  water, 
aud  iu  all  proportions  in  methyl  and  ethyl  alcohols  and  in  ether;  a 
good  solvent  of  essences,  resius,  cuiitharidiu,  morphin,  gun  cotton, 
and  in  general  of  substances  solnble  iu  ether;  burns  with  a  yellowish- 
white  flame,  Chloriu  acts  energetically  upon  it,  producing  products 
of  substitution,  varying  according  to  the  intensity  of  the  light  from 

C4HflCl202  to    C4C1^02. 

Ethyl  Accto-acetate  —  Aceto-acetic  ester  — CHa. CO. CHjCOO- 
(CaHs) — is  the  most  important  representative  of  the  class  of  0-ketunie 
iicid  esters  (p.  347),  which  arn  important  syrJtlii^ic  reagents.  It  is 
prepared  by  dissolving  6  pts.  of  metallic  sodium  in  200  pts.  of  anhy- 
drous ethyl  acetate,  distilling  off  the  excess  of  the  ester,  mixing  the 
residue  with  50  per  cent  acetic  acid  iu  slight  excess,  decanting  the 
oil  which  separates,  and  fractioning. 


ESTERS  — COMPOUND    ETHERS 


361 


The  fonnatiofi  of  aeeto -acetic  ester  in  this  process  occurs  in  sev- 
eral reaetiotis,  the  siim  of  which  may  be  expressed  by  the  equation  r 
2OH3.OOO  (C2H5)  =  Cn^i.CO.CHa.COO  (CoH:.)  +  CHrj.CH^OH  :  two 
molecules  of  ethyl  acetate  forming  one  moleenle  of  aeeto-acetie  ester 
and  one  of  ethylic  alcohoL  In  one  stage  of  the  reaction  sodium  acts 
upon  ethyl  acetate  to  form  ethyl  acetyl -sodacetate,  sodium  ethyl  ate 
and  hydrogen:  2CH3.COO(C2H5)  +Xa2=CH,.CO.CHNa.COO(C2H5) 
+C2H5.0*Na+H3.  In  another,  sodium  ethylate  acts  upon  ethyl  ace- 
tate to  form  ethyl  acetyl -sodacetate  and  ethylic  alcohol:  2CH:^.C00' 
a\H&)  +  C-Hs.O.Na^  CH3.  CO.CHNa.COOCO-H,)  +  2CHa.  CH2OH; 
and^  when  the  operation  is  properly  coudue ted,  little  or  no  hydrogen  is 
evolved,  because  that  produced  in  the  above  reaction  acts  with  sodium 
upon  ethyl  acetate  to  form  sodium  ethylate:  CH.i.COOiOjHr,) +Na2+ 
H2=2C2H5.0.Na.  The  aceto*acetic  ester  is  liberated  from  its  sodium 
derivative  by  acetic  acid:  CH:i.CO,CHNa.COU(l'i:H:i}  +  CHy.C0OH^ 
CHa.COONa+CHa.CO.CH-i.t  00{r2H5) . 

Aceto -acetic  ester  is  a  colorless  liquid,  having  a  pleasant  odor, 
b.  p.  181*^,  almost  insoluble  in  water »  and  much  more  stable  than  tlie 
free  acid.    It  is  colored  violet  by  Fe2Cl6* 

Malonic  Ester— Neutral  ethyl  malonate— COO(C2H5).CH2.COO^ 
(C2H5) — IS  obtained  by  the  action  of  llVi  upon  potassium  eyaini- 
acetate,  or  malonic  acid,  and  alcohol:  CH^CN.COOK+SCHs.ClL- 
OH+HW=KC1+NH3+COO(C2H,).CH>.COO(C,II5).  or  CQOH.- 
CH3.COOH+2CH3.CH20H"COO(C2H5) J JHsCOOd^H^)  +2H2O,  It 
is  a  colorless  liqnid,  b.  p.  198^,  sp.  gr.  1.07,  insoluble  iu  water  and 
in  alkaline  solutions. 

When,  as  in  the  cases  of  aceto-acetic  and  nmlonie  esters,  an  fster  is 
r^ferrfd  io  wifhmd  deHignnUon  of  the  contained  alkpl,  the  neutral  ethyl 
ester  is  always  understood . 

The  estei*s  of  the  ketonic  acids  and  neutral  malonic  ester  have  this 
in  common,  that  they  contain  a  OH2  group  between  two  CO  gronp^j, 
and  because  of  such  position  this  CH2  group  is  more  labile  than  the 
same  group  otherwise  placed,  as  in  hydrocarbons »  acids,  aldehydes, 
etf^.  Its  hydrogen  is  removable  to  produce  products  of  substitution 
and  of  condensation.  By  the  successive  action  of  sodium  and  alkyl 
halids  upon  these  esters,  many  products  of  substitution  are  obtained. 
First  an  atom  of  Na  replaces  a  H  atom:  CH:t.CO.CeNa.COO{C2H5} 
and  COO(C2H5).CHNa.OOO(C2Hr>).  The  second  H  atom  in  CHNa 
cannot  be  directly  replaced  by  Na.  Bnt  by  the  action  of  an  alkyl 
halid  the  alkyl  replaces  the  Na  atom:  CH3.C0.CH(CHa).C00(C.H.'i) 
and  COO(C2H5).CH(CH3).COO(C2H5),  and  in  the  compounds  so 
formed  the  second  hydrogen  atom  is  replaceable  by  Na:  CHn.CO.rXa- 
(rH3).COO(C2H5)*  and  COO  (C2H5).  CNa(CH3).C00(C,Hf.}  and, 
finally,  id  these  the  Na  is  replaceable  by  alkyls:   CH:j,CO.C(CH3)2.- 


362 


MANUAL    OF     CHEMISTRY 


COOCOiHs)  and  COO(C2H5).C(CH3)2.COO(C2H5).  The  compoiiiids 
so  obtained  are  the  mouo*  and  dialkylie  aceto- acetic  and  malonie 
esters* 

The  mooo*  and  dialkylie  aceto -acetic  esters  and  the  origioal  ^ 
ketonie  esters,  are  not  simply  saponified  by  heating  with  dilute  alka- 
lies,  as  is  nsnal  with  estei^,  but  are  decomposed  in  two  ways:  In  the 
ketonie  decomposition  they  split  at  the  COO  g^ronp  to  form  ketones: 
€H3.CO.CH2.COOCC2H6)+2KHO=CH3.CO.CH3+C03K2+CH3.CH- 
OH;  and  in  the  acid  decomposition  they  split  at  the  CO  group  t^ 
form  an  acetate  and  a  salt  of  a  mono-  or  dialkylie  acetic  acid  (p.  330) : 
CHs.CO.C  {CH3)2.C00(C2H5)  +  2KH0  =  CH^^COOK  +  (CH3)3.CH.- 
COOK+CH3.CH2OH, 

The  mono-  and  dialkyl  malonie  esters*  which  are  the  esters  of  the 
superior  homologues  of  malonie  acid  of  the  isosncciuic  type  (p.  337), 
are  similarly  obtained  by  the  successive  action  of  sodium  and  alkyl 
halids  upon  malonie  ester.  When  hydrolysed  or  heated  they  do  not 
undergo  the  ketonie  decomposition,  but  only  the  acid  decomposition^ 
splitting  off  CO2  and  forming  mono-  or  dialkyl  acetic  acids:  COO- 
(C^Hsl.C  {CH3)2.COO  (C2H5)  +2H20=  (CHa)..  CH.COOH  +  CO2  + 
2CHa.CH20H.  The  above  reactions  are  utilized  to  obtain  both  mono- 
and  dicarboxylic  acids. 

The  esters  of  the  P  ketonie  acids  are  converted  by  nascent  hydro- 
gen  into  ^   oxyacids.     Tjins  aceto- acetic    ester  yields  ^  oxy butyric] 
ester:   CH3.CO!cH2.COO(C2e5)  +  H2--CH3.CHok.CH2.COO(C2H5), 

Of  the  many  condensation  reactions  of  these  esters  we  may  men- 
tion two:  We  have  seen  (p,  301)  that  formic  aldehyde,  H.CHO, 
readily  parts  with  its  O  to  form  condensed  products.  With  aceto* 
acetic  ester  it  forms  methylene  aceto -acetic  ester:  H3C:C<^0q  q^^   *\ 

or  methylene  diaceto- acetic  ester:  '^' H^aM/^^-C^sXlH^^^^^^ 

Similarly  with   malonie  ester  it  forms  methylene   dimalonic  ester: 

iSH:!8oc>CH.CH2.CH(^gg{§g;.      Aceto -acetic    ester    condenses 

with  urea  to  form  methyluracil,  and  malonie  acid  to  form  malonyl- 
urea  each  of  which  constitutes  an  important  stage  in  a  s>ni thesis  of 
uric  acid  {p.  529). 

The  inferior  homolog^ie  of  aceto -acetic  acid,  forinyl  acetic  acid, 
has  not  the  ketonie  structure,  nXX>.CH2.C00H,  but  the  unsaturated 
constitution.  H0.CH:CH.C00H.  Its  Na  compound,  NaH.CH:CH.* 
COONa,  is  formed  by  dropping  a  mixture  of  formic  and  acetic  esters 
upon  Ka  under  ether.  This  and  the  eoiTesponding  ethyl  ester  are 
used  in  several  condenfsation  syntheses  of  cyclic  compounds. 

Amyl   Nitrate— (^|j^;}0— obtained   by   distilling   a   mixture    of 


ESTERS— COMPOUND    ETHEBS 


863 


HNO3  and  amjiic  nboho!  in  the  preseuce  of  a  arnall  quantity  of  urea. 
It  is  a  colorless,  oily  liquid;  sp.  gr.  0:994  at  10°  {50°  F.) ;  boils  at 
US°  (298,4''  F.)  with  partial  decomposition. 

Amyl  Nitrite— Aniyl  nitris  (U.  SJ— CsHu  [*^~1^'^~P^^P^^^^ 
by  directing  nitrous  f nines  into  amyl  alcohol »  contained  in  a  retort 
heated  over  a  water -bath;  purifying  the  distillate  by  washing  with 
an  alkaline  solution,  and  rectifying. 

It  is  a  slightly  yellowish  liquid;  sp,  gr,  0,877;  boils  at  95*^  (20.3*' 
F, ) .  Its  vapor,  which  is  orange-  colored,  explodes  when  heated  to  260** 
(500*^  F.).  It  is  insoluble  in  water  ;  soluble  in  alcohol  in  all  propor- 
tions. Alcoholic  solution  of  potash  decomposes  it  slowly,  with  forma- 
tion of  potassium  nitrite  and  ethyl  and  amyl  ox  ids.  When  dropped 
upon  fused  potash,  it  ignites  and  yields  potassium  valerianate* 

Amyl  Acetate — Pear  oil^- {^^jj^j  |0 — is  prepared  by  distilling  a 

mixture  of  sulfuric  acid,  amylic  alcohol  and  potassium  acetate.  It 
has  the  odor  of  pears,  is  insoluble  in  water,  soluble  in  alcohol;  and 
boils  at  125"^  (257^^  F.).  It  is  used  as  a  flavoring  ageut  and  as  a  sol- 
vent for  celluloid. 

Cetyl  Palmitatc— Cetin— ^^(^^li^ }  O"'*®^^'^  ^^^  ^^^^^  constit- 
uent of  spermaceti=cetaccum  (U*  S.,  Br  J,  which,  besides  cetin, 
contains  esters  of  palmitin,  stearic,  myristie,  and  laurostearie  acids; 
and  of  the  alcohols:  lethol,  CrjHssO;  methol,  CiJl:m<>;  ethol,  CieHstO, 
and  stethoU  CieHgeO, 

Melissyl  Palmitate  — il/*^?muy— *^J."^^^^  jO-- 67 G.— Beeswax  con- 

8t&ts  mainly  of  two  substances;  ccrotic  acid,  C27H5nO.OH,  soluble  in 
boiling  alcohol,  and  oielissyl  palniitate,  in  soluble  iti  that  liquid. 
China  wax  consists  chiefly  of  ceryl  cerotate,  C27H5:iO'2(tVH55), 


ESTERS     OF     DIHYDRIC     AIX'OHOLS     OR  GLYCOLS. 

The  glycols  behave  as  diacid  bases  and  form  with  the  monobasic 
acids  basic  and  also  neutral  esters: 


CHjOfl 

I 
CHjOH 


CH2.00C*CHj 

I 
CH2OH 

Olftol  mono-jieeUte. 


CH2.OOC.CH1 

I 
CH..0OC.CH, 


The  haloid  esters  of  the  glycols  are  also  basic  or  neutral.  The 
basic  compouuds  are  the  glycol  halohydrins,  e.  g,,  CH-iOILCHiCl^ 
Ethylene  chlorhydrin,  produced  by  the  action  of  the  hydracids  upon 
the  glycols,  or  upon  ethylene  oxid  and  its  homologues. 

The  neutral  haloid  esters  are  among  the  haloid  derivatives  of  the 


SM 


MANUAL    OF    CHEMISTRY 


paraffins,  liig^her  than  the  first  (pp.  277-281).  They  are  produced  by 
(1)  the  substitution  of  the  halogen  in  the  paraflfin  or  in  the  mono- 
halogen  paraffin;  thus  ethyl  ehlorid  :  CH3.CH2C1  yields  ethylt-ue 
ehlorid;  CHnCLCH-jCl;  (2)  by  addition  of  the  halogens  to  the  olefins 
(p.  424),  tlms  ethylene:  CH2:  CH^  yields  ethylene  bieblorid;  CH:iCL^ 
CH^Ct;  (3)  by  the  action  of  the  hydracids  upon  the  monohalogen 
olefins,  or  upon  the  glycols,  or  upon  the  glycol  chiorhydrins.  Thus 
ethylene  bieblorid  is  obtained  frona  ethylene  nionoehlorid;  (^nChCH3; 
ethylene  glycol:  CH2OH.CH2OH;  or  ethylene  chlorhydrin:  CH2OH.- 
CH2CI.  By  this  latter  method  two  isomeres:  OHCJ2.CH3  and  CHr 
CLCH2CI  may  be  produced. 

The  neutral  haloid  esters  of  the  glycols  are  the  starting  points  in 
the  preparation  of  the  glycols:  CH2Br.CH2Br+2AgHO=2AgBr+ 
CH2OH.CH2OH.  Nascent  hydrogen  converts  them  into  the  paraffins: 
CH2ClXH2Cl+2H2=2Hi;i+CH3.CHa. 

Ethylene  Chlorid— Elayl  chlorid— Dutch  liquid— CH2eLCH2Cl- 
is  obtained  by  passing  ethylene  thmngh  a  retort  in  which  chlorin  is 
generated.  It  is  a  colorless,  oily  liquid,  has  a  sweetish  taste  and  an 
ethereal  odor;  boils  at  84"'  (183.2^^  F.).  It  is  capable  of  fixing  other 
atoms  of  chlorin  by  substitution  to  form  a  series  of  compounds,  the 
most  highly  chlorinated  of  which  is  carbon  tri chlorid,  CsC'l^. 


I 


I 

I 


ESTERS     OF    THE    TRIHYDRIC    ALCOHOLS    OR     GLYCEROLS  —  GLYCERIDS. 

The  glycerols  behave  as  triacid  bases,  forming  three  series  of 
esters  with  the  monobasic  acids.  These  esters  are  the  mono*,  di-, 
and  triglycerids.  Moreover,  as  two  of  the  hydroxyls  of  the  alcohol 
are  in  the  primary  groups  CH2OH,  while  the  third  is  in  the  secondary 
group,  CHOH,  there  are  two  isomeres  of  each  mono-  and  diglyeerid 


I 


Ca2-  C20.3U3 
I 
CHOH 

I 
CHjOH 

a-Uonaeetin. 


CHaOH 
I 

I 
CH:.OH 


CHj.CaHaOa 
I 
CHOH 

1 

CH..C;;HjO. 


CHa-CyHaOj 

} 

CH.C2H30:, 

I 

CHjOH 
^9  rJiiveetin. 


CHs^CjHjOa 

I 

CH.CiH.Oj 
I 

CH^.CsrljOi 

Trincctla. 


The  haloid  esters  are  known  as  the  glycerol  halohydrins.     Of  the 

glycerol  esters  of  mineral  oxyaeids  those  of  nitric  and  phosphoric 
acids  are  of  interest. 

Glycerol   trinitrate — Nitroglycerine— Glonoln — C3H5{N03)3 — iB 

formed  by  the  action  of  a  mixture  of  H-SO4  and  HNO3  upon  glycerol. 
It  is  an  odorless,  yellowish  oil;  has  a  sweetish  taste;  sp.  gr.  1.6;  in- 
soUible  in  water,  soluble  in  alcohol  and  in  elher;  not  volatile;  crys- 
tallizes in  prismatic  needles  when  kept  for  some  time  at  O"^  (32*^  F J ; 


fuses  again  at  8°  (46.4°  F.).    When  suddenly  heated,  or  when  sub* 


I 

I 


ESTERS -COMPOUND    ETHERS 


365 


0  shock  it  is  explosively  decomposed  into  C02;N;H20  and  O. 
Alkalies  saponify  it  to  glycerol  and  a  nitrate. 

Nitroglycerol  is  mixed  with  diatomaeeous  earth  and  with  other 
inert,  absorhent  substances  in  dynamite  and  in  other  high  explosives; 
and,  combined  wtlh  Ditroeetlulose,  it  forms  *Vsniokeless  powder," 

It  is  used  in  medicine  as  a  cardiac  stinuilaut,  and,  in  overdose,  is 
an  active  poison,  producing  effects  somewhat  similar  to  those  caused 
by  strychnin. 

Glycero-phosphoric  Acid — C^HsCOH )2.0. PO3H2 — is  the  mono- 
glycerid  of  phosphoric  acid.  It  is  a  proiluct  of  decomposition  of  the 
lecithins,  or  phosphorized  fats  (p.  367),  or  may  be  formed  by  mixing 
glycerol  and  metaphosphoric  acid.  It  is  a  thick  syrup,  which  is  de- 
composed into  glycerol  and  phosphoric  acid  when  heated  with  water* 
It  is  a  dibasic  acid. 

Glycerol  Esters  of  Organic  Acids. — The  triacid  glycerol  esters 
of  the  acids  of  the  acetic  and  acrylic  series  containing  an  even  number 
of  carbon  atoms  occur  in  the  animal  and  vegetable  fats  and  oils. 

Tnbutyrin—C3H5(O.C4H70) 3— 302— exists  in  butter.  It  may  also 
be  obtained  by  heating  glycerol  with  butyric  acid  and  TI2SU4.  It  is  a 
pungent  liquid,  very  prone  to  decomposition,  witii  liberation  of 
butyric  acid* 

Tricaproin  —  C^Hs  ( O .  C^HyO )  3  —  386  —  Tricaprylin  —  C3H5  ( O .  Cb- 
Hi^OJa-^TO — andTricaprin — €3H3{O.CiuHiiiO)3 — 554 — exist  in  small 
quantities  in  milk,  butter,  and  cocoa  butter. 

Tripalmitin— CaHsCO.CiftHijiO),-} — 806^— exists  in  most  animal  and 
vegetable  fats,  notably  in  palm  oil.  It  may  also  be  obtained  by  heat- 
ing glycerol  wnth  8  to  10  times  its  weight  of  palmitic  acid  for  8  hours 
at  250°  (482'"^  P.).  It  forms  crystalline  plates,  very  sparingly  soluble 
in  alcohol,  even  when  boiling;  very  soluble  in  ether.  It  fuses  at  50° 
(122^  P.),  and  solidifies  again  at  4V  (114.8°  F.). 

Trimargarin — ^r3H5(O.CnH3aO)3 — 848— has  probably  been  ob^ 
tained  artificially  as  a  crystalline  solid,  fusible  at  60°  (140°  F.),  so* 
lidifiable  at  52°  (125.6*^  F.).  The  substance  formerly  described  under 
this  name  as  a  constituent  of  aniuial  fats  is  a  mixture  of  tripalraitin 
and  tristearin. 

Tristearin — C3H5(O.Ci8H350)3 — 890 — is  the  most  abundant  con- 
stituent of  the  solid  fatty  substances.  It  is  prepared  in  large 
quantities  as  an  industrial  product  in  the  manufacture  of  stearin 
candles,  etc,  hut  is  obtained  free  from  tripalmitin  only  with  great 
difficulty » 

In  as  pure  a  form  as  readily  obtainable,  it  forms  a  hard,  brittle, 
crystalline  mass^  fusible  at  G8°  (154.4''  FJ,  solidifiable  at  61*"  (141.8'^ 
P.);  soluble  in  boiling  alcohol,  almost  insoluble  iu  cold  alcohol, 
readily  soluble   in  ether. 


366  MANUAL    OP    CHEMISTRY 

Triolein — C3B[5(O.Ci8H330)3 — 884 — exists  in  varying  quantity  ia 
all  fats,  and  is  the  predominant  constituent  of  those  which  are  liquid 
at  ordinary  temperatures.  It  may  be  obtained  from  animal  fats  by 
boiling  with  alcohol,  filtering  the  solution,  decanting  after  twenty- 
four  hours'  standing;  freezing  at  0°  (32°  F.),  and  expressing. 

It  is  a  colorless,  odorless,  tasteless  oil;  soluble  in  alcohol  and 
ether,  insoluble  in  water;   sp.  gr.  0.92. 

The  Neutral  Oils  and  Fats  are  mixtures  in  varying  proportions 
of  the  triglycerids  of  the  acids  of  the  acetic  and  acrylic  series,  princi- 
pally tripalmitin,  tristearin,  and  triolein.  The  first  two  of  these  are 
solid  at  the  ordinary  temperature  and  the  last  liquid.  In  the  oils  the 
last  predominates,  in  the  fats  the  former.  In  the  cold  the  oils  be- 
come solid  (fats),  and,  on  heating,  the  fats  become  oils.  The  fats 
and  oils  are  usually  odorless,  white  or  yellow,  unctuous  to  the  touch, 
and  produce  a  translucent  stain  upon  paper.  They  are  insoluble  in 
and  lighter  than  water,  readily  soluble  in  ether,  petroleum  ether,  ben-  . 
zene,  and  many  other  organic  solvents.  Although  the  oils  do  not 
mix  with  water,  and  promptly  rise  to  its  surface  after  having  been 
agitated  with  it,  an  oil  may  remain  suspended  for  a  long  time;  sus- 
pended in  very  minute  globules  in  an  aqueous  liquid,  if  bile,  pan- 
creatin,  albumen,  or  other  emulsifying  agents  be  present.  Such  a 
mixture,  sometimes  practically  permanent,  is  called  an  emulsion. 

Like  other  esters  the  fats  and  oils  are  hydrolyzed  or  saponified 
when  heated  with  steam  or  with  a  caustic  alkali.  The  alcohol, 
glycerol,  is  liberated,  and,  if  steam  be  used,  the  fatty  acid  also;  while 
if  an  alkali  be  used  a  soap  is  formed,  which  is  a  salt  of  the  fatty  acid. 
The  sodium  soaps  are  hard,  those  of  potassium  soft.  Castile  soap  is 
a  sodium  soap,  made  from  olive  oil.  Yellow  soap  is  made  from  tal- 
low or  other  animal  fat,  and  contains  about  one -third  of  its  weight 
of  rosin.     Lead  plaster  is  lead  soap. 

The  fixed  oils  are  so  called  to  distinguish  them  from  the  volatile 
oils,  more  properly  called  essences,  which  are  also  unctuous  to  the 
touch,  and  render  paper  translucent,  but  which  are  hydrocarbons, 
not  esters. 

The  vegetable  oils  form  three  classes  :  (1)  The  non-drying,  or 
greasy  oils,  which  remain  liquid  and  greasy  on  exposure  to  air. 
Olive  oil  aud  peanut  oil  are  representatives  of  this  class.  (2)  Drying 
oils,  which  dry  and  become  hard  when  exposed  to  air.  These  oils, 
which  contain  linoleic  acid  (p.  430),  are  used  in  making  paints. 
Linseed,  hemp,  poppy,  and  sunflower  oils  are  drying  oils.  (3)  Semi- 
drying  oils  are  intermediate  between  the  other  two  classes,  and  are 
more  or  less  drying:.  In  this  class  are  cottonseed,  sesame,  rape  seed, 
and  castor  oils.  The  animal  oils,  used  for  dressing  leather,  as  lubri- 
cants and  for  illumination,   are  fish  oils,  whale,  and  porpoise  oil. 


ESTERS   OP   POLYHYDRIC    ALCOHOLS,    ETC.  367 

neat's  foot  oil,  lard  oil,  aud  tallow  oil.  Cod  liver  oil  contains,  be- 
sides the  glycerids  of  oleic,  myristic,  palmitic,  and  stearic  acids, 
small  quantities  of  those  of  butyric  and  acetic  acids.  It  also  contains 
certain  biliary  principles,  a  phosphorized  fat,  traces  of  iodin  and 
bromin,  probably  in  organic  combination,  a  peculiar  fatty  acid  called 
gadinic  acid,  a  brown  substance  called  gadinin,  and  two  alkaloidal 
bodies  :  asellin,  C25H32N4,  and  morrhuin,  C19H27N3.  Sperm  oil  is 
not  a  true  oil,  but  a  liquid  wax;  it  contains  no  glycerids,  but  consists 
mainly  of  esters  of  the  higher  monoatomic  alcohols. 

Lecithins  —  Phosphorized  Fats. — These  substances  are  widely 
distributed  in  animal  and  vegetable  tissues  and  fluids,  and  are  par- 
ticularly abundant  in  the  yolks  of  eggs,  brain,  and  nerve  tissue, 
semen,  and  blood -corpuscles  and  plasma,  where  they  probably  serve 
as  material  for  the  formation  of  the  more  complex  phosphorized 
bodies  such  as  protagon  and  the  nucleins.  The  lecithins  are  colorless 
or  yellowish,  imperfectly  crystalline  solids,  of  a  waxy  consistency, 
and  very  hygroscopic.  They  do  not  dissolve  in  water,  but  swell  up 
in  it  like  starch.  They  are  soluble  in  chloroform,  in  benzene,  and  in 
hot  alcohol  and  hot  ether.  Prom  alcoholic  solutions  they  crystallize 
in  fine  needles.  When  heated  with  baryta  water  or  with  acids  they 
are  decomposed  into  glycero- phosphoric  acid  (p.  365),  cholin  (p.  383) , 
and  a  fatty  acid,  usually  palmitic  or  stearic.  The  lecithins  are  there- 
fore derivatives  of  glycero -phosphoric  acid,  in  which  the  two  remain- 
ing hydroxyls  of  the  glycerol  are  replaced  by  fatty  acid  residues,  and 
one  of  the  two  remaining  basic  hydrogen  atoms  of  the  phosphoric  acid 
is  replaced  by  the  basic  radical  of  cholin,  which  is  a  quartemary  am- 
monium : 

//(OH3)3 

/O.N.CHo.CHo.OH 
0:P— OH 

\O.CH2.CH(C,8H3r>02).CH2(CioH3l02) 

Stearyl'Palmityl  lecithin. 

From  the  above  formula  it  will  be  seen  that  the  lecithins  may 
anite  with  acids,  through  the  remaining  OH  of  the  cholin,  or  with 
bases,  through  the  remaining  basic  H  of  the  phosphoric  acid,  to  form 
salts.  The  lecithins  differ  from  each  otliei*  in  the  nature  of  the  fatty 
acids  entering  into  their  composition.  Distearyl- ,  dioleyl-  and  stearyl- 
palmityl  lecithins  are  known. 

ESTERS  OP  POLYHYDRIC  ALCOHOLS,  AND  OF  ALDO-  AND  KETO- 

ALCOHOLS 

The  superior  alcohols  form  esters  with  the  pure  acids  in  the  same 
manner  as  does  glycerol.  Tetra-acetyl  erythrol:  C4H6( 0211302)4, 
Tetra-nitro    erythrol:    C4H«(N03)4;     Hexacetyl    mannitol:     CoHo- 


368 


MANUAL    OF    CHEMISTRT 


(CjHsO'i)^  and  Hcxanitro  mannitol:    C«Hri{N03)e  are  examples  of 

&{ieh  compounds. 

The  bexosos  also  form  esters  with  mineral  and  organic  acids. 
Thus  diacetic  glucose,  CflHio04(C02.CHa)2,  is  formed  as  a  very  bitter 
solid,  very  soluble  in  water,  alcohol  and  ether,  by  the  at'tion  of  aeetic 
anhj^drid  upon  glucose,  Thls^  heated  with  acetic  anhydrid  at  IW^, 
furnishe.s  triacetic  glucose,  C(}Ha03{CO'j.CHd}3,  which,  in  turn,  is 
converted  into  tetracetic  glucose,  CeU80i(C02.CH3)4t  by  the  actioa 
of  acetic  anhydi-id  at  160°. 

Acctochlorhydrose—CHO.  (CH.C02.CH3)4.CHiCl— is  formed  by 
heating  d-glnt*ose  with  acetyl  ehlorid:  CeHrjOe+^C^HaO.Cl^Cn  Hi^- ^J 
OijCl+SHCl+HsO.  It  is  a  colorless,  odorless,  bitter  seini-soHd,  insoK  ^H 
uble  in  water^  soluble  in  alcohol  and  in  ether.  It  reduces  Feh]ing*a 
solution.  Heated  in  presence  of  water,  it  regenerates  glucose. 
Heated  with  potassium  pheuate,  it  forms  glucosyl  pbenate,  or  phenol- 
glucosid,  CHO.  tCH.C02.CHa)4.CH,CI  +  (:gH5X>.K.+  4H20=CHO,- 
(CHOH)4CHl>.O.C6H5+KCH-4CH3.COOH,  the  simplest  of  the  glu- 
cosids,  substaneee  frequently  referred  to  as  esters  of  ghicosc,  but 
which  are  more  properly  composite  ethers  containing  glucose  and 
phenolic  residues,  united  by  oxygen  (p.  465). 


ESTERS    OP    OXTACIDB^ — LACTIDS    AND    L.ACTONES. 

The  oxyaeids  not  only  form  esters  with  the  alcohols  in  the  same 
manner  as  the  pare  aeids,  but,  being  themselves  both  alcohol  and 
acid,  they  produce  cyclic  esters,  in  the  formation  of  which  thej'  play 
the  part  of  alcohol  as  well  as  that  of  acid.  The  lactids  are  formed  by 
the  interaction  of  two  oxyacid  niolecnles,  each  performing  the  functions 
of  both  alcohol  and  acid.  The  lactones »  which  are  formed  only  by  the 
y  and  higher  oxyaeids,  are  produced  from  a  single  molecnle  of  the  acid, 
whose  carboxyl  and  alcoholic  gi-onps  interact  with  each  other*  The 
following  formnlaa  will  indicate  the  genesis  of  the  lactids  and  lactones: 


CH,OH 

I  + 

COOH 


coon 
CH2OH 


OlrcoUifl  Kcld. 


CH.,roo 

I     "     I 
COO.CH2 


GlypolHd 
(Lnctid.) 


COOH 
[ 
a  CHa 

I 

I 
7  CH2OH 


cooi 

I 

a  CH2 
I 

I 
7CH3 


7,-Oiy butyric    %  Butyrotactoti* 

acid.  (Lfccton©.) 


The  y  lactones  are  formed  from  the  y  monohalogen  acids  :    (1)  by 

distillation  :  COOH.OH2.CH2.CH3Cl=COO.(Je2,CH2.0H2+HCI;    (2) 
by  boiling    with    H2O.    KHO    or    K2C03:COOH.CH2.CH2.CH2CI+ 

KHO^H20+KCl+COO.CH2.CH3.CHa. 


I 


ESTERS    OF    OXYACmS 


369 


By  redaction  the  higher  iactoues  yield  aldo-hexoses.    Thus  d-gln- 
is  produced  by  the  reduction  of  the  lactone  of  d- gluconic  acid: 


TOO. 


.(CH0H)4 


HOH)4.CH2+H2=0 
carboxyltc   acids  readily  lose  water  and  are  converted  into  lactones 
(p,  343). 

Acylation — Determination  of  Hydroxy  1,  etc, — The  formation  of 
esters  by  the  introduction  of  acidyls,  referred  to  as  acylation,  is 
utilijsed  to  determine  the  number  of  aieoholic  or  phenolic  {p.  443) 
hydroxy  is  contained  in  a  molecule.  The  acidyls  usually  resorted  to 
for  this  purpose  are  acetyl,  CHn.CO,  and  benzoyl  (pp.  456,  468), 
CbHs.CO;  and  the  reactions  most  frequently  employed  are  those 
between  the  substance  examined  and  the  oxid  or  eh  lor  id  of  the  acidyl. 
Thus  morphia,  which  contains  two  hydroxy  Is,  one  alcoholic  and  one 
phenolic*  and  acetic  anhydrid  produce  diacetyl^morphtu:  C17H17NO- 
(OH)2+(CH3.CO)20=CitHi7NO(0,OC.CH3)3  +  H20  ;  phenol  and 
acetyl  chlorid  produce  phenyl  acetate:  C(jHs.0H+CHa.C0Cl=C(jH5.- 
COCCIIt+HCI;  and  methyl  alcohol  and  benzoyl  chlorid  produce 
methyl  benzoatei  H.CH20H+C6ns.COCl=-C(iH5.COO(CHa)-hHCL 
The  H2O  produced  when  the  anhydrid  (or  acid)  is  used,  and  the  HCl 
with  the  chlorid,  interfere  with  the  completeness  of  the  reaction  (see 
below),  and  to  remove  them  the  operation  is  conducted  in  the  presence 
of  anhydrous  sodium  acetate  in  the  former  case,  and  of  an  alkali 
or  pyridin  (p,  518)  in  the  latter.  In  some  instances  where  the  forma- 
tion of  HoO  or  HCl  must  be  avoided,  and  that  of  SH2  is  immaterial, 
thioacetic  acid,  CHa.COHH,  is  used  to  "acetylize/' 

Certain  precautions  are  necessary  in  applying  acylation.  The  H 
of  the  ^oujvs  NH,  NH2  and  SH  are  also  replaceable  by  acidyls  (see 
dJamins,  p.  385),  hence  if  present  they  must  be  taken  into  account. 
In  some  instances  secondary  reactions  intervene.  Thus  tartaric  acid, 
allhouffh  containing  four  hydroxyls,  only  two  of  which  are,  however, 
non-carboxylie,  takes  up  four  molecules  of  acetyl  chlorid,  because  of 
the  secondary  dehydrating  action  of  the  latter:  2CH.t.COCH-H20^ 
CH3X'0}20-t-2HCl,  and  diacetyl  tartaric  anhydrid  is  formed: 


CHOH.COOH 

1 
CHOH.COOH 


+4CH3.C0C1=^  I 


CH0{C0.CH3).C0v         CHaXOv 
=^  I  >n-u  N 


CH0{C0XH3).C0^        CH3.C0 


/ 


0+ 


V 


0+4HC1. 


This  may  be  avoided  by  '* protecting''  the  labile  groups.  Thus  di- 
acetyl tartaric  ester  is  formed,  and  only  two  molecules  of  acetyl 
chlorid  enter  into  the  reaction,  if  tartaric  esters  be  used  in  place  of 
the  free  acid: 

CHOH.COOCCsHs)  CHO{CO.CH3).COO(C2Hjj) 

I  +2CH3.C0C1^  I  -j-2HCi. 

CH0H.C00(C2Hi)  CHO(CO.CHa),COO(C2H5) 


370  MANUAL    OP    CHEMISTRY 

The  process  of  alkylation,  i.  e.,  the  replacement  of  H  in  OH  by 
alkyls  to  form  esters,  has  more  limited  application.  Alkyls  may 
replace  the  H  of  OH  in  carboxyl  COOH,  in  the  methoxyl  group  of  the 
primary  alcohols,  CH2OH,  and  in  the  phenolic  hydroxyl,  CeHs.OH, 
but  not  in  the  secondary  and  tertiary  alcoholic  groups  CHOH  and 
OOH.  Therefore,  alkylation  may  sometimes  be  resorted  to  to  differ- 
entiate the  latter  hydroxyls  from  the  former. 

Sometimes  direct  esteriflcation  of  alcohol  and  acid  may  serve  to 
determine  carboxylic  hydroxyl  in  the  absence  of  methoxyl  or  phenolic 
hydroxyl.  But  as  this  reaction  is  a  reversible  one,  and  is  therefore 
not  complete  (p.  89),  it  can  only  be  resorted  to  when  means  are 
adopted  to  remove  one  of  the  products  and  thus  prevent  the  estab- 
lishment of  equilibrium  until  the  reaction  is  completed.  Usually  it  is 
the  water  which  is  removed  by  dehydrating  agents  such  as  KHSO4. 
Thus  the  reaction  between  tartaric  acid  and  ethyl  alcohol:  COOH.- 
(CH0H)2C00H+  2CH3.CH20H<==>COO(C2H5).  (CH0H)2.C00- 
(C2H5)+2H20  may  be  made  to  progress  from  left  to  right  by  re- 
moving the  water  formed,  by  passing  a  current  of  dry  HCl  through 
an  alcoholic  solution  of  the  acid.  Or  the  formation  of  water  may 
be  avoided  by  using  a  salt  of  the  acid  whose  cation  forms  an 
insoluble  compound  with  a  halogen,  and  a  haloid  ester.  Thus  with 
silver  formate  and  methyl  iodid:  H.COOAg+CHsI^H.COOCCHs) 
+AgI. 

Phenolic  hydroxyl  may  be  distinguished  from  that  of  carboxyl 
by  the  fact  that  the  esters  produced  by  the  latter  are  readily  bydro- 
lyzed  by  alkalies,  but  the  phenolic  esters  are  not.  The  alkyls  of 
alkyl  halids  not  only  readily  replace  the  hydrogen  of  NH,  NH2, 
and  SH,  but  may,  in  aromatic  compounds,  become  directly  linked  to 
carbon. 

The  number  of  carboxyls  in  an  acid,  its  basicity,  may  be  de- 
termined either  by  the  electric  conductivity  of  solutions  of  its  sodium 
salt  (p.  75),  or  by  determination  of  its  molecular  weight  and  the 
percentage  of  metal  in  its  salts,  usually  the  silver  salt,  or  by  titration 
with  normal  alkali. 

SULFUR   DERIVATIVES   OF   THE   PARAFFINS 

As  the  mineral  sulfids  and  sulf hydrates  correspond  to  the  oxids 
and  hydoxids,  so  there  exist  thioethers  and  thioalcohols,  which  are 
the  counterparts  of  the  simple  ethers  and  of  the  alcohols,  as  well 
as  thioaldehydes,  thioketones  and  thioacids.  Moreover,  as  sulfur 
may  be  quadrivalent  or  hexavalent,  as  well  as  bivalent,  there  exist 
other  important  compounds,  the  sulfoxids,  sulfones  and  sulfonic 
acids,  which  have  no  oxygen  analogues. 


SULFUR  DERIVATIVES  OF  PARAFFINS 


371 


The  followiiijf  formuloe  will  serve  to  illustrate  the  relations  of  the 


oxygen  and  tliio  eonipuoiitJs: 


CHjOH 

I 

Ithjlie  Alcohol. 

CH28H 

I 

CHi 
KilurUe  ihioAleohoL 


/CH2.CH, 


O 


\CH2.CH3 
Etiiri  ozid. 


8 


\CH,XH, 


COOH 

CHj 
Acetic  acld« 

COSH 

I 
CH, 

ThloftcetSe  acid. 


/O.CHj.CHj 

CHjXH 

\0,CH2,CHi 
AeeUl. 

/8.CH2.CH, 
CHi,CH 

\8  CHj.CH, 


Thiocthers,  or  Sulfids  —  are  produced  by  processes  correspoDding 
to  those  by  which  the  ethers  are  formed  ^  (1)  by  distilling  salts  of 
etliyl- sulfuric  acids  with  potassium  sulfide  2KS04.C2H5+K28^S- 
(C2Hi)2+2K2SO^;  (2)  by  the  action  of  alkyl  halids  upon  potassium 
sulBil:  2CHaCl  +  K2S=S(CH3)2+2KCl;  (3)  by  the  action  of  phos- 
phonig  peiitasitlfid  upon  the  oxygen  ethers:  40(C2H5)2+P2S5=S{C2- 
Hs)j+2(C2H5)3P02»S2.  The  last  is  a  general  method  by  which  the 
thio  com  pounds  may  be  obtained  from  the  corresponding  oxygen 
<soraj>oimds,  the  secondary  products  being  thiophosphoric  esters. 

Tlie  thioethers  are  colorless  hc|uids,  insoluble  in  water,  soluble  in 
tlcohot  and  ether,  of  disagreeable  odors.  They  contrast  with  the  oxy- 
gen others  chiefly  in  their  additive  power,  dependent  upon  the  greater 
valence  capacity  of  sulfur-  Thus  they  combine  with  alkyl  iodids  to  form 
*ulhne  iodids,  or  sulfonium  todids,  in  which  the  sulfur  is  quudriva- 
l^ut:  S(C-;H5)2+C2H5l=LS(C2H5)3:  and  on  oxidation  they  yield  snl- 
fcxidsruid  sulfoncs,  in  which  the  sulfur  is  quadrivalent  and  bexavalent. 

Thioalcohols — Mercaptans— are  formed:  (1)  by  the  action  of  po- 
^a^MnaiKulfbydnitc  upon  alkyl  halids:  KHS  +  CHa/cH.Cl^CHa.CHa- 
**^n+KCI;  {2}  by  distilling  the  salts  of  the  acid  alkyl  sulfates  with 
porwHiiim  su I f hydrate :  K8O4 ( C2H:J  +  KHS  =  CHa.CH2SH  +  K2SO4 ; 
ajul  (3)  by  rlie  action  of  phosphorus  pentasulfid  upon  the  alcohol. 

The  rhi<i»lcohols  differ  in  some  of  their  general  inactions  from  the 

•leohols:   While  the  H  of  the  OH  of  alcohols  can  only  be  replaced  by 

K  and  Xa  among  the  metals,  the  II  of  SH  may  be  replaced  hy  the 

iewvy   metals   as   well.     Tlius   with   mercuric   oxidr    2CH3.CH2SH  + 

flgO  =  (CH3.CH2S)2Hg+H20,     Such  metallic  compounds  are  called 

mercaptids*  and  the  name  ^*mercaptan^^  {mfrnfrittm  mptans),  is  due 

the  formation  of  mercury  mercaptid.    Owing  to  the  greater  valence 

pacity  of  sulfur,  the  thioalcohols  do  not  yield  thioaldehydcs  and 

ioacids  on  oxidation.     By  limited  oxidation    mercaptans,  or  mer- 

ptids,  form   disullids:    4CH3.CH20H  +  02=2CH3.CH2.8.S.CH2.' 

+  2H3O;    and  by  more  active   oxidation  alkyl   sulfonic   acids; 

2CHt,CH2SH+203--2  >8( 

O^     XqH 


372 


MANUAL    OF    CKEMlSTRr 


Ethyl  mercaptan— Ethyl  suifhydrate—Thioalcohol— CHaXH2.- 

SH — is  prepared  iudustrially,  as  the  first  step  in  the  formatiou 
of  sulfoiial,  by  the  fit-st  of  the  geoeral  inethmk  given  above.  It  in 
a  colorless  liquid,  sp,  gv,  0.8325,  boils  at  36.2°  (97.2°  P.),  has  an 
intensely  disagreeable  odor,  burns  with  a  blue  flame,  is  neutral  in 
reaction^  sparingly  soluble  in  water,  soluble  in  alcohol  and  in  ether* 
dissolves  I,  S  and  P.  Potassium  and  sodium  act  npon  mereaptan  as 
they  do  upon  aletjhol,  replacing  the  extra -radical  hydrogen  to  produce 
mercaptids*  or  thioethylates,  corresponding;  to  the  ethylates. 

There  also  exist  mono-  anil  di'thioglycols,  currespoiiding  to  the 
dihydrie  alcohols  (p,294).  One  of  these,  monothioethylene  glycol: 
C2H4»OH,SH»  yields  isethionic  acid  on  oxidation  (see  below). 

Suifoxids  and  Sulfones  —  are  prodncts  of  oxidation  of  the  sulfide. 
in  which  the  sulfur  is  quadrivalent  or  hexavalent; 


Ethyl  &umd. 


>s 


Ethyt  folfaxid. 


4 


Other  products  of  oxidation  of  thio-eompoumls,  containing  the 
gronp  (80^)'^  attached  to  a  hydrocarbon  group,  are  also  called 
sulfones  (see  below). 

Sulfonic  Acids  —  are  acids  containing  the  group  (O2S.OH)'  at- 
tached to  n  hydrocarbon  group,  ^he  sulfonic  acids  of  this  series 
are  formed  by  oxidation  of  the  mercaptans:  by  the  action  of  the 
parfifRn  iodids  upon  the  alkaline  sulfites;  or  by  the  action  of  sulfuric 
aeid  upon  alcohols,  etliers,  etc.  (see  Aromatic  Sulfonic  Acids).  They 
may  be  considered  as  being  derived  from  the  unsyra metrical  sulfurous 
acid  (p.  144)  by  replacement  of  the  H  atom  by  an  alkyl;  and  are 
isomeric  with  the  moiioalkyl  sulfites  (formula  below),  from  which 
they  are  distinguished  by  the  fact  that  the  latter,  being  esters,  are 
saponified  by  alkalies,  which  the  former  are  not. 

The  thioglycols  on  oxidafimi  also  3  ield  sulfonic  acids.  Isethionk 
acid,  C2H1.OH.SO3H,  mentioned  above,  is  a  thick  liquid,  whose 
amido  derivative  is  taurin  (see  Araido* acids). 

In  tlie  thiosulfonjc  acids»  which  only  exist  iu  their  salts  and 
esters,  the  oxygen  in  tlie  hydroxyl  of  the  sulfonic  acids  is  replaced 
by  sol  fur. 

Sulfinic  acids  bear  the  same  relation  to  hydrosnlfnraus  acid 
that  the  sulfonic  acids  do  to  the  unsymmetrical  sulfurous  acid: 


O/'^XOH 

Un83rmiiit*l'ri<»al 


0\q/  C2H5 
0/^\0H 
Etby]  AalfonW 
lulil. 


Mono**thyl'i!« 
siilflte 


Hydroial  foroiu 
mc\d. 


Etbyl  tiilllnlc 
Arid, 


Thioaldchydcs  and  their   Sulfoncs.— The  simple    thioaldehyde^ 
ai*e  not  known,  owing  to  the  tendency  to  polymerize  which  they  po&' 


SULFUR    DERIVATIVES    OF    THE    PARAFFINS 


373 


Bess  to  a  still  more  marked  dugree  than  the  ahlehydes  (p.  300).  The 
trithioaldehydes  and  their  isiilfooes  are  odorless,  colorless  solids. 
^  Trithioformaldehyde,  or  parathioformaldehydei  crystalUsses  in 
needles,  insoluble  in  water,  f.  p,  216^^,  aatl  forms  crystalline  com- 
pounds with  AgNOa  aud  PtCl4.  It  is  produced:  (1)  by  the  action  of 
nascent  H  upon  carbon  bisnlfld:   3CS:!+6H2=(CH>H)3+3SH2;     (2) 

I  by  heating  methylene  diiodid  with  Na^S:    3CH2l2+3Na2S^(CH2S)3 
+6NaI;    (3)  by  the  action  of  H2S  on  formic  aldehyde:  3H.CH0+ 
3H2S=(CH2S)3+3H20;     (4)   by  the  reduction  of  thiocyanic  acid: 
aCNSH  +  6H2=(CH2S)3+3NH3. 
p^  The  relations  of  these  compounds  are  shown  by  the  formulf^:  I 


I 
I 


O-Cv^H     ^-"^XH  °\0H„0/™"      ^\CH,.8/^^*   °"^Ch'.8o'/ *^0« 


Thlofonnle 
atd«K7de. 


Triform- 
&]dflhjrde« 


Trlthlofom* 


Trlai«thyleD« 


In  triinethylene  trisulfone  the  SO2  groups  influence  the  included 
CH2  groups  in  the  same  manner  as  do  the  CO  groups  10  the  ketonic 
aod  raalonic  esters  (p.  361);  their  H  atoms  are  similarly  replaceable 
by  Na,  and  this  by  alkyls. 

Thioacetals — Mercaptals — are  produced  by  the  action  of  paraffin 
iodids  upon  alkali  mereaptids,  or  by  the  action  of  HCl  upon  a  mix- 
ture of  aldehyde  and  mercaptan.  By  oxidation  they  yield  sulfones, 
whose  methylene  hydrogen  may  be  replaced  by  alkyl  groups  : 


.      di«thrleUi«r 


Metkylfltie 
mere«pial« 


Metbjrliane  dletlijfl 
■Blfone. 


HXp/SOa.CjHj 
CH3/^\802,CaHfc 

Ethldene  dicithjl 
sulfono. 


Thioketones. — The  simple  thioketones,  (CH3)2:CS,  corresponding 
to  the  acetones,  (CH3)2:CO,  are  not  known.   But,  when  P2S5  acts  upon 

acetone,  dithioketonc,  (CH3)2:C<^  ^C:  (CH3)2  is  produced  as  a  yellow 

liquid,  b.  p.  184°,  which  is  reduced  by  nascent  hydrogen  to  isopropyl 
mercaptan:  (CH:i)2rCH.SH.    By  the  action  of  H2S  upon  a  mixture  of 

/S.C(CHj)2v 
&C€tone  and  HCl/trithioacetonc,  (CH3)2C  /S,  is  produced. 

Mercaptols  and  their  Sulfones. — The  mercaptols  are  substances 
^hich  maybe  considered  as  derived  from  the  ketones  bJ^substitlltion  of 
^wo  thioalkyl  groups  for  the  oxygen.    Thus  acctone-cthyl  mercaptoU 


CH. 


\n/ 


^>f  dithioethyl-dimethyl  methane^        yCv 


S.C2H5 


is   derivable   from 


one,  CHa.CO.CHs.    They  are  formed  by  the  action  of  HCl  upon  a 
laixture  of  acetone  and  mercaptan  r    CH3.CO.CH3  +  2CH3.CH:.SH  = 

<t%),:C;(S.C2H5)-^+H.O.      Or   sodium    ethylthiosulfate,   which    itj 
decomposed  by  mineral  acids,  with  formation  of  uiercaptau:  C2H5S.* 


374  MANUAL    OF    CHEMISTRY 

S03Na+H20=NaHS04+CH3.CH2SH,  may  be  used  in  place  of  the 
thioalcobol.  Ethyl  mercaptol  is  a  mobile  liquid,  of  not  unpleasant 
odor,  b.  p.  190°,  manufactured  as  a  step  in  the  production  of 
sulfonal.  The  sulfones  are  obtained  from  the  mercaptols  by  oxidation. 

Sulfonal — Acetone  Diethyl  Sulfone — Disulfethyl'dimeihyl methane 
— (CH3)2:C:  (S02C2H6)2— is  obtained  by  oxidizing  ethyl  mercaptol  by 
potassium  permanganate.  It  crystallizes  in  thick,  colorless  prisms, 
difficultly  soluble  in  cold  water  or  alcohol,  readily  soluble  in  hot  water 
or  alcohol,  and  in  ether,  benzene  and  chloroform.  It  fuses  at  126° 
(226.8°  F.)  and  boils  at  300°  (572°  F.),  suflPering  partial  decomposition. 

Sulfonal  contains  two  ethyl  groups,  trional  contains  three,  and 
tetronal  four.  Their  hypnotic  power  increases  with  the  number  of 
ethyl  groups  which  they  contain.  Other  "sulfonals"  are  obtainable 
from  the  corresponding  mercaptols  by  methods  similar  to  the  above. 
Among  these  is  acetone  dimethyl  sulfone,  which  contains  no  ethyl 
group,  and  has  no  hypnotic  action.  The  relations  of  these  com- 
pounds is  shown  by  the  following  formulae  : 

CHa/^XSOs.CjHs  CaHj/^NSOz.CjHs  C2H5/ ^ \SO2.C2H5  CHs/^XSOj.CHa 
Sulfonal.  Trional.  Tetronal.  Acetone  dimethyl 

sulfone. 

Ichthyol.-ris  the  Na  salt  of  a  complex  sulfonic  acid,  having  the 
empirical  formula  C28H36S306Na2,  obtained  by  the  distillation  and 
purification  of  an  ozocerite  (a  mineral  pitch).  It  is  a  dark  brown, 
pitchlike  mass,  having  a  disagreeable  odor,  soluble  in  water  and  in 
glycerol. 

Thioacids  and  their  Thioanhydrids. —  In  the  thioaeids  of  the 
acetic  series  the  sulfur  is  substituted  for  the  oxygen  in  the  hydroxy  1. 
Thioacetic  acid,  CH3.CO.SH,  is  formed  by  the  action  of  phosphorus 
pentasulfid  upon  acetic  acid. 

Thiolactic  Acid— CH3.CHSH.COOH— is  formed  by  the  continued 
heating  of  ethyl-a-chloropropionate  with  potassium  hydrosulfid,  and 
decomposition  of  the  ester:  CH3.CHCl.COO(C2H5)-+KHS+H20= 
CH3.CHSH.COOH+OH3.CH2OH+KCI.  It  crystallizes  in  needles, 
f.  p.  142°.  It  and  the  P  acid:  CH2SH.CH2.COOH  are  of  interest  in 
connection  with  cystin  (p.  421). 

Thioacids  derivable  from  Carbonic  acid. —  Five  of  these  com- 
pounds are  known  in  their  derivatives,  although  the  free  acids  are 
unknown,  or  very  unstable.      The  formulsB  of   the  free   acids   are: 

C^\OH'  CO\SH'  CS\OH'  ^S\OH»  ^^^  ^^\SH. 

Carbon  Disulfid  —  CS2 — bears  the  same  relation  to  sulfothiocar- 
bonic  acid,  CS<('qh,  and  to  trithiocarbonic  acid,  CS^q^,  that  carbon 
dioxid  bears  to  carbonic  acid   (p.  340).     It  is  prepared  by  passing 


ORGANO-METALLIC    COMPOUNDS 


375 


vapor  of  S  over  C  heated  to  redness,  is  partly  purified  hy  rectifit^a- 
tion,  aud  obtained  pure  by  redistillation  over  mercurie  ehlorid. 

It  is  a  colorless  liquid.  When  pure  it  has  a  peculiar,  but  not 
disa^eeable  odor,  the  nauseating  odor  of  the  commereial  product 
being  due  to  the  presence  of  another  sulfurated  body;  boils  at  47^ 
(IIB-G*^  FJ;  sp.  gr,  1.293;  very  volatile.  Its  rapid  evaporation  in 
vacuo  produces  a  cold  of  — 60*^  ( — 76*^  F.).  It  does  not  mix  with 
H2O,     It  refracts  light  strongly. 

It  is  highly  inflamroable,  and  burns  with  a  bluish  flame,  giving: 
off  CO2  and  SO2;  its  vapor  forms  highly  explosive  mixtures  with 
air,  which  detonate  on  contact  with  a  glass  rod  heated  to  250** 
(482°  Fj.  Its  vapor  forms  a  mixture  with  nitrogen  dioxid,  which, 
when  ignited,  burns  with  a  brilliant  flame,  rich  in  actinic  rays, 

A  substance  also  exists,  intermediate  in  composition  between  COj 
and  CSa,  known  as  carbon  oxysulfid,  CSO,  which  is  an  inflammable, 
colorless  gas,  obtained  by  decomposing  potassium  thiocyanate  with 
dilute  H2SO4. 

Toxicology. — Workmen  engaged  in  the  manufacture  of  CS-,  and 
in  the  vulcanization  uf  rubber,  as  well  as  others  exposed  to  the  vapor 
of  tiie  disulfid,  are  subject  to  a  form  of  chronic  poisoning  which  may 
be  divided  into  two  stages*  The  first,  or  stage  of  excitation,  is 
marked  by  headache,  vertigo,  a  disagreeable  taste,  and  cramps  in  the 
legs.  The  patient  talks,  laughs,  sings,  and  weeps  immoderately,  and 
sometimes  becomes  violently  delirious.  In  the  second  stage  the  patient 
becomes  sad  and  sleepy,  sensibility  diminishes,,  sometimes  to  the 
extent  of  complete  ana?thesia,  espeeinlly  of  the  lower  extremities,  the 
lieadache  becomes  more  intense,  the  appetite  is  greatly  impairedi 
and  there  is  general  weakness  of  the  limbs,  which  terminates  in 
paralysis, 

ORGANO -METALLIC    COMPOUNDS. 


These  are  compounds  of  organic  radicals  with  metallic  elements, 
the  best  known  being  those  of  the  alkyls  with  zinc  and  mercury. 

Zinc-mcthyl,or  Zinc  Mcthid— (CH3)2Zu,  and  Zinc-ethyl,  or  Zinc 
Ethid— (C2H:>)2Zn— are  formed  by  heating  to  130''-150''  methyl  or 
ethyl  iodid  with  excess  of  zinc  amalgam »  and  distilling  without  con- 
tact of  air.  They  are  colorless  liquids,  the  former  b.  p.  46^^,  sp.  gr. 
1.386,  the  latter  h,  p.  US'",  sp.  gr.  1J82.  On  contact  of  air  they 
Ignite  and  burn»  giving  oflF  dense  clouds  of  ZnO.  By  the  moderated 
action  of  air  they  produce  solid  oxyalkylates:  Zn^  q  ^^j  »  or  alcohol- 

ates:  Zn^Q^^uJ.    The  former  are  also  produced,  along  with  hydro- 
carbons, by  the  action  of  zinc -alkyls  upon  alcohols:    CCH3)2Zn  + 


376 


MANUAL     OF    CHEMISTEV 


H,CH20H=CH:t.O.Zu.CH3+CH^:   aii<l  are  decomposed  by  water  with 

formation  of  hydrocarbons  and  primary  alcohols:  Cn3.0.Zn.CIl3H- 
2n20=ZoH2O2+HXH20H+Cei.  With  the  halogens  the  ziuc  alkyls 
react  violently  to  form  alkyl  halidsr  (Cll3)2Zn+2Bro=2CH:,Br+ 
ZnBra.  They  unite  with  sulfur  dioxid  to  produce  zinc  alkyl -sulfinates 
(p.  372):   tCi*H5)2Zu+SO2=(O:S:(o'^0^Zn.    With  aeidyl  chlorids 

and  aldehydes  they  form  complex  compounds,  which  are  decomposed 
by  water  to  form  ketones,  or  tertiary  or  secondary  alcohols. 

NITROGEN    DERIVATIVES    OF  THE  PARAFFINS. 

Speaking  strictly,  the  onl3"  nitrogen  derivatives  of  the  paraffins  are 
the  nitril8»  derived  from  the  paraffins  by  subsitution  of  N  for  H3,  as 
CHa.CN,  from  CH3.CH:j  and  the  diazo  paraffins,  (N2)''CH.CHa,  but 
the  compounds  derivable  from  the  paraffins  and  from  their  oxidation 
prodncts  by  substitution  of  nitrogen  containing  groups,  NO2,  NO, 

NH2t  NH,  NOH, N:N ,  and  =N.N^,  are  numerous,  varied 

and  important. 

NITROPARAFFINS. 

The  univalent  group  (NO2)  is  designated  by  the  syllable  nitro  in 

the  names  of  compounds  containing  it. 

The  mooonitroparaffins — isomeric  with  the  nitrons  esters  (p.  S59) , 
are  derived  from  the  paraffins  by  the  substitution  ol  NO2  for  an  atom 
of  hydrogen,  and  are  distinguished  as  primfiry,  serondary  and  ter- 
iinrtj,  in  the  same  manner  as  the  corresponding  alcohols  (p.  283) 
according  as  the  NO2  is  united  to  CH2»  or  OH,  or  0.  They  are  formed 
by  the  action  of  the  alkyl  iodids  upon  silver  nitrite:  CHuI+AgNOs^ 
Agl+CHaNOo. 


I 


They  are  isomeric  with  the  nitrous  esters:  CH^.CHs.N^q—  monotii- 
troethane,  and  CH3.CH2.OX:  O^^Ethyl  nitrite.  These  isoraeres  may  be 
distinguished  by  the  action  of  KHO,  which  saponifies  the  esters :  CiH^.- 
ONiO+KHO=KON:0+CH3.CH20H.  but  has  no  action  upon  the 
nitropa  raffing. 

Nascent  hydrogen  converts  them  first  into  hydroxy lara  in  com- 
pounds (p.  152)  r  CH3.N02+2H2=CH3.NH.OH+H20.  which  are  in 
turn  further  reduced  to  monamins,  or  amidoparaffins :  CH3,NH.OH+ 
H2^NH2.CH3+H20. 

Nitrous  acid  converts  the  primary  nitroparaffins  into  nitrolic 
adds,  as  ethyl-nitroUc  acid,  CHs.C^J^Qpji  the  liquid  assuming  a  red 
color.  The  same  agent  converts  the  secondary  nitroparaffins  into 
pseudonitrols,  as  propyl  pseodonitrol,  cHa/^\No'»  ^^^  liquid  be- 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  377 

eoming  blue*  Upon  the  tertiary  yitro paraffins  uitroiis  acid  has  no 
action*  These  reactioDs  are  utilized  to  distiogiiish  primary,  s^eeond- 
ary,  and  tertiary  alcohols  from  each  other.  The  alcohol  is  first 
converted  into  an  iodid,  which  is  then  digitilled  with  AgNCh.  The 
distillate  is  then  treated  with  KHO  and  KNO2,  and  dilute  H2BO1  is 
added. 

AMINS    AND    AMMONIUM    DERIVATIVES. 

The  am  ins  are  eoraponnds  derived  from  ammonia  by  the  snbsti- 
tution  of  alky  Is  for  a  part  or  all  of  its  hydrogen. 

They  are  classified  into  monamins^  derived  from  a  single  molecule 
of  ammonia,  diamins,  derived  from  two  such  molecules,  and  triamins, 
derived  from  three, 

MONAMINS    AND    THEIR    DERIVATIVES. 

The  monainins  are  primoryp  secondary,  or  tertiary,  as  one,  two» 
or  three  of  the  hydrogen  atoms  of  ammonia  have  been  replaced. 
They  are  also  distinguished  as  amtn,  imin,  and  nitril  bases.  Whcn^ 
in  secondary  or  tertiary  amins,  the  substituted  radicals  arc  alike  the 
amins  are  designated  as  simple,  when  the  radicals  are  different  the 
amins  are  mixed.  The  primary  manamins,  eontainiiig  the  group 
NH'i ,  are  am i d o >paraf f i n s ;  while  the  secon da ry ,  co n t ai  ri  i  t j  g  t  h e  ^vo n  p 
NH,  are  imido-paraffins.   The  monarains  have  the  algebraic  formula, 

A  nomenclature  similar  to  the  above  is  also  used  in  speaking  of 
nitrogen  in  other,  more  complex,  organic  compounds.  It  is  said  to  hf 
in  primary  combination,  or  as  amid,  or  amin  nitrogen,  when  in  the 
amido,  or  amino  group  (NHo)',  in  secondary  combination,  or  as 
imid,  or  imin  nitrogen,  when  in  tlip  imido,  or  imin,  group  (NH)",  and 
in  tertiary  combination,  or  as  nitril  nitrogen,  when  in  the  form  N'". 
A20-.  diazo-,  and  hydrazo-  nitrogen  is  in  the  forms — N:N — and 
=X.N=. 

The  monamins  are  sometimes  called  compound  ammonias,  from 
Ifaeir  resemblance  to  ammonia  in  their  chemical  properties,  as  well  as 
from  their  origin.  They  combine  with  water  to  produce  quartcrnary 
ammonium  hydroxids,  similar  in  constitution,  alkalinity,  and  basicity 
to  ammonium  hydroxid;  and  with  acids,  without  elimination  of 
hydrogen,  to  form  salts,  similar  to  the  ammoniacal  salts. 

The  aliphatic  monarains  are  the  most  simply  constituted  of  a  great 
variety  of  nitrogen  derivatives,  including  the  primary  monamids  (p* 
399),  the  diamids,  such  as  urea,  and  the  vegetable  alkaloids  (p.  545), 
whi4*b  have  this  in  common  with  the  amins,  that  they  are  basic  in  char* 


378   ^  MANUAL    OP    CHEMISTRY 

acter,  and,  in  combining  with  acids,  form  salts  in  the  same  manner  as 
ammonia  does,  i.  e.,  by  change  of  the  nitrogen  valence  from  three  to 
five,  and,  consequently,  without  elimination  of  hydrogen.  As  the 
hydroxids  and  salts  of  such  basic  nitrogen -carbon  compounds  are 

addition  products:  N''' (CH3) 3+ H20=HO.N^^fcH3) 3 »  ^^e  bases  them- 
selves are  in  this  sense  unsaturated  compounds  (p.  269). 

/H                       /H  /H  /CHs 

N— H            H2=N— H  N— H  H2=N--CH, 

\H                       \CaH3O2  \CH3  \C1 

Ammonia.                 Ammonium  Monomethyl-  Dimethylammo- 

ftceUte.  amin.  niamehlorid. 

NH2  NH2  CHj  CHj 

II  /\  /\ 

CO  CO  H2C        CHj  HjC        CH, 

I  l-#H3  II  II 

NH,  N-NOs  H2C        CH2  HjC        CH, 

\/  \/ 

N  N 

I  /\ 

H  01    H, 

UrM.  Una  nitrate  t  Piperidin.  Piperidin  hydroelilorid. 

The  naming  of  these  compounds  has  been  the  subject  of  much 
discussion.  As  the  substances  formed  by  the  union  of  ammonia  with 
acids  are  regarded  as  salts  of  ammonium,  not  of  ammonia,  so  these 
compounds  are  not  salts  of  urea,  piperidin,  morphin,  etc.,  but  salts 
of  hypothetical  bases,  containing  a  quinquivalent  nitrogen  atom, 
which  in  the  free  base  is  trivalent.  The  names:  ureium  nitrate,  piper- 
idium  chlorid,  morphium  sulfate,  etc.,  are  therefore  the  analog^^es  of 
ammonium  acetate  and  dimethylammonium  chlorid.  For  the  ehlorin, 
bromiu,  and  iodin  compounds  the  names:  piperidin  hydrochlorid, 
morphin  hydrobromid,  quinin  hydroiodid,  etc.,  may  be  conveniently 
retained,  they  being  regarded  as  the  free  bases,  plus  hydrogen,  plus 
the  halogen.  The  following  formulae  indicate  the  constitution  of  the 
amiuss  and  their  hydroxids  and  salts: 


N— H 

/CH3 

N— C2H5 

\H 

\H 

Ethylamin. 
(Primary). 

Methyl- 

ethylamin. 

(Secondary). 

/CH3 

N— CH3 

(CH3)4N.OH 

(CaH5)4N.Cl 

\CH3 

Trimelhyl- 

Tetrametbyl 

Tetrethyl 

amin. 

ammoDiom 

ammonium 

(Tertiary). 

hydroxid. 

ehiorid. 

The  primary  monamins,  the  hydraniins,  and  the  diainins  (p.  385) 
may  also  be  considered  as  derived  from  the  monohydric  and  dihydric 
alcohols  by  substitution  of  NH2  for  OH.    (See  also  p.  382) : 

CH3  CH3  CH2OH  CH,OH  CHoNH, 

III  !  I 

CH2OH       CH0NH2     CH2OH  CH2NH2         CH2NH2 

Alcohol.  Monamin.         Glycol.  Hydramin.  Diamln. 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS 


379 


The  primary  roonamins  are  formed:  (1)  by  distilling  the  iso- 
cyanic  esters  with  caustic  potash:  CO:N.C2nB+2KHO=NH2,C2H3+ 
COnKs;  (2)  by  heating  the  alkyl  ioditls^  or  the  nitric  eaters,  with 
alcoholic  ammonia:  C2H5l  +  KH3=NH-i.C2Hr.+ HT,  or  C^Hr^NOa  + 
NH3=NH2.C2H5+HN03;  (3)  by  the  actioii  of  nascent  H  In  alcoholic 
solution  upon  the  nitrils  (p.  393)  i  CH3.CN+2H2=NH2.C2H5;  {4)  by 
the  af*tion  of  nascent  II  upon  the  nitroparaffins:  CHa.NO^+SH^^NHs- 
€H.T+2H20;  (r>)  from  the  monaniids  (p.  400)  of  the  fatty  seriea 
monamins,  containing  one  atom  of  carbon  less  than  the  amid,  are 
formed  by  the  action  of  bromin  and  potassinm  hydroxid.  The  reac- 
tion occurs  in  two  stages.  Fii*st  a  broiiiid  is  produced:  C2H5.CO.- 
NII^+Brs-fKHO^CoHs.CO.NHBr+KBr+HaO,  which  is  in  turn 
converted  into  the  arain  with  loss  of  the  carbonyl  group:  C^Hb.CO*- 
NHBr+3KHO=CjIl5.Nn2+CO,K:i+HuO+KBr;  (G)  l.y  redu.?tion  of 
aldoxims  and  keiuxims  {410). 

The  secondary  monamins  are  formed,  as  intermediate  products, 
by  the  action  of  the  alkyl  iodids  upon  the  primary  monamins  in  the 
presence  of  excess  of  ammonia.  The  alkyl -nmmoninm  iodid  is  first 
produced:  NlI^.t^Hs+C-IIJ^NniCaHs)-!!!,  and  this  reacts  with  the 
ammonia:  NH(C2H.)3FiI  +  NH:^=-XII(C'iH,)3+NHJ.  The  final  prod- 
ucts of  the  reaction  are  the  tetramujonium  iodids :    N(C2ll5)iI* 

The  tertiary  monamins  are  obtained  by  tlic  dry  distiUation  of  the 
quarternary  ammonium  hydroxids^  iodids,  or  ehlorids:  N(C-jH5)4l  = 
N(  Calls Jri+CjII.'il;  or  by  heating  the  primary  or  secondary  amins  ivith 
excess  of  potassium  alkvl  sulfate:  NH(CH:,)2+CHaK,S04=N(C2ll5):« 
+  KHSO4. 

The  alkalinity  and  solubility  in  water  of  the  primary  monamins 
are  greater  than  those  of  tlie  secondary,  and  those  of  the  secondary 
greater  than  those  of  the  tertiary. 

The  primary  aud  secondary  amins  react  with  esters  of  the  mtmo-car- 
b<ixylie  acids  to  form  alcohols  and  primary  or  secondary  am  ids  (p.  400), 
Thus  methylamin  and  methyl  acetate  produce  ethyl  alcohol  and  aceta- 
mid:  H2NXH3  +  CHa.COO(CHa)  =  CHa.0H2OH  +  H2N.(CO.eUa). 
With  esters  of  dicarboxylic  acids  primary  monamins  produce  mono - 
or  dialkyl  diamids  (p,  406);  secondary  monamins  produce  esters  of 
alkyl  amic  acids  (p.  4(12),  alcohols  being  formed  in  lioth  cases;  and 
tertiary  monamins  are  ncjt  acted  upon.  Thus  oxalic  ester  produces 
dimethyloxamid  with  methylamin,  and  dimethyloxamic  ester  with  di- 
inethylamin:  2H2N,(lI:,  +  (bo(C2Hf^)-COO(r2H^)=H:,C.HN.CO.CO.- 
KHX'H.i-f  2CH:i.CH20H,  and  HN:  (CHy)n+COO(C2H5)  COOCCsHs) 
=  (CHa)2N.CO.COO(C2ll5)+CH3.CH20H,  These  last  reactions  are 
titilized  in  Hof mannas  method  of  separating  primary,  secondary  and 
tertiary  annns.  as  the  diamids  produced  are  soluble  in  water,  but  the 
amic  esters  are  not. 


380 


MANUAL    OF    CHEMISTBY 


Formic  aldehyde  eondeuses  with  priiiuiry  am  ins  to  form  cyclie 
amins,  with  secondary'  am  ins  to  form  alkyl  duimiiis  (p,  386),  and  has 
no  action  upoa  tertiary  amins.  As  the  boiling  points  of  these  products 
and  of  the  tertiary  amins  differ  widely,  this  reaction  is  also  utilized  to 
sepanite  the  amins.  Formic  aldehyde  with  methylamiii  produces  tri- 
metliyl  trimethylene-amiu;  and  with  dimethykmiu,  tetrauiethyl  me- 
thylene  diamin:     3H2NXH3+3H.CHO--H2C<^^[cSI;ch:)n(CH^ 

3H,0;   andi:HX(CH3)2+HX110=(CHs)2N.CHn.N(CH3')2+H20. 

Mor<^  rapid  methods  of  distinguishing  nitril,  imid  and  amid  nitro- 
gen in  the  amins,  and  other  similar  basic  substances,  ai'c  based  upon 
their  varying  beliavior  with  certain  cyclic  aeidyls.  Thus  benzene 
sulfoehlorid,  CflHs.SO^Cl  (p.  469),  in  the  presence  of  alkali  has  no 
action  npou  tertiary  amins;  with  secondary  amins  it  forms  insoluble^ 
oily  or  tiolid  prodncts,  which  precipitate;  and  with  primary  amins  it 
produces  phenylsnifoamids  which  remain  in  sohition  in  the  alkali,  but 
are  precipitated  by  addition  of  HCl  as  ci'ystalline  solids,  having' 
definite  fusing  points. 

A  slight  elevation  of  temperature  (to  50°)  causes  the  decomposition 
of  ammonium  nitrite  with  evolution  of  free  nitrogen:  (NH4)N02^= 
N2+2H2O,  Similarly  nitrous  acid  and  primary  amins  enter  into  double 
decomposition  with  liberation  of  the  nitrogen  of  both,  and  formation  of 
alcohols^  either  primary, secondary  or  tertiary :  HjN.CH:i+HX02^N2+ 
H.CHiOH  +  HsO.  This  I'eaction  is  common  to  the  amido  group,  NH2,  in 
almost  all  aliphatic  compounds,  and  the  liberation  of  free  nitrogen  by 
the  action  of  nitnuis  acid  is  utilized  to  detect  the  presence  of  this 
group  in  such  compounds.  The  amido  group  in  cyclic  compounds  be* 
haves  differently  with  nitrons  acid,  forming  azo*  or  diazo  compounds^ 
containing  the  bivalent  azo  group  — N:N —  (p.  481)  *  and  occasional  in- 
stances of  similar  behavior  with  aliphatic  compounds  arc  met  with,  as 
in  the  formation  of  the  azo-fatty  acids:  (N:N)CH.COOH,  Nitrous 
anid  with  the  secondary  amins,  containing  the  imido  group,  XH,  forms 
nitroso  amins^  containing  the  nitroso  group  ^'NO).  Thus  dimetbylaTnin 
forms nitrosodimethyl  amin :  HN(CH:i)2+nN(X>^NO.X(Cll:;}2+H20. 

Or  the  existence  of  amido  or  imido  groups  and  their  number,  in 
both  aliphatic  and  cyclie  compounds,  may  be  determined  by  acylation 
or  alkylation  (p.  369),  an  amido  group  taking  np  two  acidyls  or 
aJkyls,  and  an  imido  group  but  one. 

The  primary  monaniins,  when  warmed  with  chloroform  and  alco- 
holic potash,  yield  carbylamins,  isocyanids,  or  tsonitrils  (p,  394): 
NH2.C2H,+CHCb+3KHO  =  CN,C2H5+3KCl+3H20.  (See  Chloro- 
form, test  1,  p.  279  J 

When  ethereal  solutions  of  primary  monamins  and  of  carbon  disnl- 
fid  are  evaporated,  a  residue  is  obtained  which,  when  heated  in 
aqueous  solution  with  AgNOa,  or  Pe^Cle,  or  Hg€l2  forms  a  sullid  of  the 


NITROGEN    DERIVATIVES    f»F    THE    PARAFFINS 


381 


metal  and  a  ''mustard  i>il/'  liaviug  a  pun^f-nit  odor.  This  is  Hoff- 
mail's  test  for  primary  moiiamins  (see  p.  379), 

The  hydrocdilorids  of  the  amiim  and  of  many  other  basic  carbon* 
nitrogen  compounds  in  which  the  nitroffen  behaves  as  it  does  in  am- 
motiia  in  the  formation  of  salts,  also  resemble  ammonium  chlorid  in 
that  they  form  crystalline,  and,  frequently,  dlfficiiltly  soluble  chloro- 
platinates  witli  PtCU.  Thus:  inethylamin  chloroplatioate,  (HjCN^* 
Hy)'jPtCl6.  These  eoiiipoundSj  along  with  the  crystalline  chloraurates: 
(HtC.NH3)AnCb,  and  pierates:  (H,iC.NH3}O.C6H2(N02)3,  which  are 
also  formed  by  sneli  carbon -nitrogen  compounds,  are  largely  utilized 
for  their  separation,  identitication  and  analysis. 

There  also  exist  am  ins  of  the  type  R^NiR/',  such  as  methylene- 
inethylamin:  CHu.N:CILi*  v^^hich  are  formed  by  the  action  of  formic 
aldehyde  upon  the  annus:  CH:i.NHj+Il.CH0=CII:,.N:CH:;+H20. 
(See  also  diamins,  p.  385  J 

Methylamin — yhthyiia — ^TI'iN.CHa — is  a  colorless,  intlammuble 
gas,  having^  a  fishy,  ammoniacal  odor.  Very  sqluble  iu  water  {1,154 
volumes  in  one  at  12.5*^) »  forming  a  highl.v  caustic  and  alkaline  soln- 
tion.  It  neutralizes  acids  with  formation  of  methyl  aujuK>uiuui  salts, 
which  are  soluble  in  water.  Its  eldoroplatiuate  crystallizes  iu  yellow 
scales,  soluble  in  water,  insoluble  iu  alcohol  r  its  chloraurate  iu  yellow 
needles,  soluble  iu  water,  alcohid  and  ether, 

Dimethylamin  — />/wf/Ai//m— HX(CH:i)'j-^is  a  liquid  below  7.2°, 
has  an  ammoniacal  odor,  and  is  very  soluble  in  water.  Its  chloro- 
platiiiate  forms  yellow  needles. 

TrifnethylaTnin—TrhuHhtfUa- — N(CH:j)a — is  formed  by  the  action 
of  methyl  iodid  upon  NH;f,  and  as  a  product  of  decomposition  of  many 
organic  substances.  It  occurs  naturally  in  combination  in  cod-liver 
oil,  ergot,  ehenopodiuui*  yeast,  guano,  and  many  tlowers.  It  is  an 
oily  Hipiid  below  9"^',  having  a  fishy  odor,  alkaline,  solubh?  in  water, 
alcohol  and  ether.  Its  chloroplatinate  crystallizes  in  octahedra, 
lusolublu  in  alcohol. 

T!ie  three  niethyhimius  were  first  obtained  from  herring-piekle. 
Tbeyare  formed  as  early  products  of  putrefaction  (*f  fish,  starch -paste, 
brain-  and  tnuscular  tissue,  and  proteins,  along  with  ethylamiu  and 
dietliylamin.  The  counnercial  '*trituethylamin  *'  obtained  by  dry  dis- 
tillatioti  of  distillery  waste,  is  a  mixture  of  the  three  methylaniins  in 
about  the  pn>pf>rtions:  40,  50  and  10  per  cent. 

Ethylamin— ILiN.CH-i.Cfl:^— is  a  mobile  liquid,  b.  p.  18°,  wIjIcIi 
expels  riuirnouia  from  ammouiacsU  salts. 

Propylamine H:.N.CnL^.Cn:i.(;H:,'-is  also  a  liquid^  b.  p.  49'',  ob- 
tained from  propionitriL  The  medicinal  substance  called  rhhrid  q/ 
Mtcalia  is  not  this  ainin.  but  its  isomei'e»  trimethylamiu. 

Tetramethyl-ammonium  Hydroxid— HO.N{CII;0t— is  a  quarter- 


382  MANUAL    OP    CHEMISTRY 

nary  ammonium  hydroxid,  corresponding  to  ammonium  hydroxid, 
and  is  obtained  by  decomposing  the  iodid,  IN(CH3)4,  which  is  formed 
by  the  action  of  methyl  iodid  upon  trimethylamin.  It  is  a  crystalline, 
deliquescent,  caustic  solid,  not  volatile  without  decomposition.  Like 
other  carbon -nitrogen  hydroxids  and  hydramins,  it  absorbs  carbon 
dioxid  from  the  air. 

Tetrethyl-ammonium  Hydroxid — HO.N(C2H5)4 — forms  strongly 
alkaline,  deliquescent  needles,  and  has  been  used  as  a  solvent  for 
uric  acid. 

There  are  also  primary  monamins  corresponding  to  the  secondary 
and  tertiary  alcohols  (p.  283),  which  are  monamins  containing  iso-  or 
meso-alkyls  (p.  274),  and  are  called  carbinamins.  Those  correspond- 
ing to  the  secondary  alcohols  are  obtained  (1)  by  reduction  of  the 
ketohydrazones  (p.  410),  (2)  by  reduction  of  the  ketoxims  (p.  410), 
and  (3)  by  the  action  of  P  alkyl  iodids  upon  ammonia.  Thus  iso- 
propylamin,  or  dimethylcarbinamin,  is  obtained  (1)  from  dimethyl- 
acetone  hydrazone:  (CH3)2:C:N.NH.C6H5+2H2=(CH3)2:CH.NH2 
+C6H5.NH2;  (2)  from  acetoxim:  (CH3)2:C:NOH+2H2=(CH3)2: - 
CH.NH2+H2O;  and  (3)  from  fi  iodopropane  and  ammonia:  CH3.- 
CHI.CH3+2NH3=(CH3)2:CH.NH2+NH4l. 

OXYAMINS    (hydramins),    DIAMINS,    IMINS    AND    DIIMINS. 

The  primary  monamins  may  be  considered  as  being  derived  from 
the  monoatoraic  alcohols  by  the  substitution  of  theamido  group,  NH2, 
for  the  hydroxyl.  From  the  dihydric  alcohols,  the  glycols,  two  classes 
of  amido  compounds  may  be  similarly  derived.  One  of  these,  the 
oxyamins,  hydroxamins,  or  hydramins,  contain  a  single  amido  group, 
and  retain  an  alcoholic  hydroxyl.  In  the  diamins  both  hydroxyls  are 
replaced  by  amido  groups.  The  oxyamins  are  primary,  secondary  and 
tertiary  in  the  same  manner  as  the  monamins: 


CH20H 

1 

CH2OH 

CH2NH2 

1 

CH2(OH).CH2\ 

NH 

CH2(OHVCH2\ 
CH2<OH).CH2— N 

CH20H 

CH2NH2 

CH2NH2 

CH2(OH).CH2/ 

CH2(OH).CH2/ 

Glycol. 

Oxyethyl- 

Methylene 

Dioxyethylene- 

Trioxethylene- 

amin. 

diamin. 

amin. 

amln. 

The  primary  oxyamins  are  produced:  (I)  by  the  action  of  airimonia 
upon  thehalohydrins:  CH20H.CH2Cl+NH3=CH20H.CHoNH2+HCl; 
(2)  by  the  action  of  H2SO4  upon  the  unsaturated  amins.  Thus  vinji- 
amin  yields  oxyethylamin:  CH2:CH.NH2+H20=CH20H.CH2NH2;  (3) 
Primary,  secondary  and  tertiary  oxyamins  are  formed  by  the  union  of 
ammonia  with  alkylen  oxids:  (CH2)20+NH3=CH20H.CH2NH2;  or 
2(CH2)20+NH3=(CH20H.CH2)2NH;  or  3(CH2)20+NH3=(CH2- 
OH.CH2)3N. 


]SnTROGEN    DERIVATIVES    OF    THE    PARAFFINS 


383 


Cholin  —  TrbmthyUxethylammonium  hydroxid  —  Bilineurin  —  Sin- 

cihtm   OH 
ealin  —  I  /         — occurs  in  hops,  in  fungi,  in  certain  seeds,  iu 

CH,.N=(CHah 
the  human  piacenta,  in  bile,  in  the  yoiks  nf  eg^s*  and  iu  the  <.*erebro- 
[spinal  fluid  iu  epilepsy  and  other  organic  diseases  of  the  nervous  syBtern. 
I  It  is  a  constituent  of  the  lecithins  (p.  3B7) .   It  is  formed  synthetit^aliy  (as 
itschlorid)  by  the  union  of  ethylene  chlorhydrin  and  trim e thy lainiuL 
CH,OH  CH2OH    CI 

I  +    N(CH3)a==^         I  / 

CH3CI  CH3— N=(CH3)3 

It  is  produced  during  the  first  forty -eight  hours  (»f  putrefaction  of 
animal  tissues,  from  the  deeomposition  of  the  lecithins,  and  flirninishes 
from  the  third  day,  when  other  ptomaTos  (neundin,  pntrescin,  cada* 
verin)  increase  in  amount.  When  heated,  it  splits  up  into  glycol  and 
triroethylamin.    Nitric  acid  converts  k  into  muscariu. 

It  is  a  thick  s.vnip,  soluble  iu  H^O  and  in  alcohol,  and  strongly 
alkaline  in  reaction.  Even  in  dilute  aqueous  solution  it  prevents  the 
coagulation  of  albumin  and  redissolves  coagulated  albumin  and  fibrin. 
It  is  a  strong  base;  attracts  CO2  from  the  nir;  forms  with  HCl  a  salt, 
soluble  in  alcohol,  which  er^'stallizes  in  plates  and  needles,  resembling 
those  of  cholesterin.  Its  chloropktinate  is  purified  witlj  (Hfliculty ;  its 
chloroaurate  readily.    It  is  poi.sonous  only  in  large  dua>efci. 

Aman itin  —  Trimeth y hxethylidinea mmon tmu    h ydroxid  — Isocholin 

CHj  OH 

—  I  X        — is  au  isomere  of  cholin,  existing  along  with  mus- 

CHOH.X=(CH:,)a 

cariQ  (see  below)  iu  Agariais  muscarius.     It  is  produced  by  raethyl- 

ation  of   aldehydeammonia :    CHa.CHOH.NH-i.     By  oxidation    with 

HJ^Os  it  >ie!ds  muscarin. 

CIIiOU     OH 

Muscarin —  I  /  — is    related  to  cholin,   neurin   and 

CHOH.N=(CHab 
amanitiu,  from  which  it  may  be  obtained  by  oxidation. 

It  occurs  in  nature  iu  Agaricuif  muscarius^  and  is  produced  during 
putrefactive  decomposition  of  proteins. 

The  free  base  occurs  in  very  deliquescent,  irregular  crystals,  or»  if 
not  perfectly  dry,  a  colorless,  odorless,  and  tasteless,  but  strongly 
alkaline  syrup;  readily  soluble  in  all  proportions  in  water  and  in 
alcohol;  very  sparingly  soluble  in  chloroform;  insoluble  iu  ether,  It 
is  a  more  powerful  base  than  ammonium  hydroxid.  When  decom- 
po6ed  it  yields  trimethylamin.  Its  ediloroplatinate  crystallizes  iu  octa* 
bedra.     Its  chlorid  forms  colorless,  brilliant,  deliquescent  needles. 

When  administered  to  animals,  muscarin  causes  increased  secre- 
tion of  saliva  and  tears;  vomiting;  ev^UL-uaticm  of  f^ces,  at  first  solid, 
later  liquid ;  contraction  of  the  pupils,  almost  to  the  extent  of 
closure:  diminution  of  tlie  rapidity  of  the  pulse;  interference  with 
reispiration  and  locomotion;  gradual  sinking  of  the  heart's  action  and 


384 


UAL    OF    CHEMISTRY 


as  that  whii^h  would  be  derived  from  elioliri; 


respirutioii;   tiiid  death.    Atro(»i!i  prevents  tlie  «ctioa  of  nuiscarin  and 

diminishe.s  its  iuteiisitv  when  already  established. 

CHa        OH 

base  resembling  eholin,  for  which  reason  it  is  considered  here,  al* 
thoui?h  its  proper  place  is  as  a  derivative  of  viuylamin  (q.  v.).  It 
has  been  obtained  from  brain  tissue  and  from  the  suprarenal  eapsule, 
probably  as  a  product  of  decomposition  of  protagon.  It  is  produced 
from  cholin  by  boiling  with  baryta  water.  The  same  body  is  one  of 
the  alkaloids  produced  by  the  putrefaetion  of  muscular  tissue,  and  is 
endowed  witli  poisonous  qualities,  reseinbUug,  but  less  intense  than, 
those  of  muscarin, 

Betains  —  are  lactams  (p.  412)  of  hH»othetieal  substances,  such 

cn.oH 
I         /OH       by  oxida- 

COOH 
tion  of  the  methoxyl  group  to  a   'i*rboxyl:    I         /OH      .    Although 

this  substance,  containing  both  carboxyl  and  basic  hydroxyl,  is  uo- 
knowu,  the    eorresptonding    betaln  aldehyde  and  ehlorid  are   known 

(see  formuhe  below). 

COOH    OH 
The  betaitis  have   the  general  formula:    i        X      ,  in  which  R" 

may  be  any  bivalent  hydrocarbon  radical^  and  in  which  the  three 
remaining  nitrogen  valences  may  be  satisfied  by  univalent  radicals 
or  by  a  trivaleut  radical.     Or  the  arrangement  of  the  valences  may 

COO" 

be  reversed,  as  in  nieotic-methvl  betaiui     1  I 

(CnHi)''=X-CB,. 

Betai'n — Trimdhyhareiic  hetmn—Oj-yneurin—OxychoUn — Lycin — 

COO 
Trimdhul-glucovoll —  I     \  — ^was   first  obtained    from   beet- 

CH.— N=(CR3)3 

juice  (Beta  vulgaris).  It  exists  in  beet-sugar  molasses,  in  cotton- 
seed, and  iu  malt.  It  is  formed  by  several  synthetic  methods,  e.  g., 
by  the  action  of  methyl  iodid  upon  amido-acetic  acid  (p.  413): 
COOH  coo 

I  TaCH3l=3HH- 1      \  ;  or  by  the  interaction  of  mono- 

€H,.NH2  CH3-N=CCH3)3. 

COOH  COO 

chloracetic  acid  and  trimethvlamin;  I        +N(CH3h=  |      \  -f-HCK 

CH.Cl  CHs-'N^fCHj)! 

Betain  crystallizes  in  large,  deliquescent  crystals,  with  one  mole- 
cule of  water  of  crystallization,  very  soluble  in  water  and  in  alcohol. 
It  is  decomposed  by  heat  with  evolution  of  trimethvlamin,  a  fact 
which  is  utilized  to  obtain  that  substance  from  beet -molasses.  It  is 
strongly  basic  and  forms  crystalline  salts.  Its  chloraurate  is  crys- 
talline and  very  sparingly  soluble  in  cold  water. 


NITBOGEN    DERIVATIVES    OF    THE    PARAFFINS 


385 


The  relations  of  the  oxyamin  bases  are  shown  in  the ,  following 


formolaB: 


(CHa), 


CH| 
CHs 

i 


\ 


OH 

Xtbyl-trimeUiyl 
unmonlnm 
Ikydnudd 


COH 

CHs 


N 
(CH,),OH 

B«UXb 


CHsOH 
CHt 

^\ 
(CH,),OH 

OhoUn. 


COOH 

I 
CH, 

I 

N 

(CHj),Cl 

B«UXn 
liydroehloiAd. 


CH) 

CHOH 

I 

^\ 
(CH,)3  0H 

Itoebolin. 
(Amanltia). 

COO, 


CHs 

N— -* 

(CH3), 
B«Uln. 


CHsOH 

I 

CHOH 

(CHj)3  0H 

MllMAllB. 


CHs 

L 
'     I 

N 

^\ 

(CH,),OH 

Naoila. 


HiN.CHj.CHi.CHi.NHi 


^^XCHs.CHj/^^ 


Diamins — are  primary,  secondary,  and  tertiary,  as  they  contain 

two  groups  NH2,  or  two  groups  NH,  or  two  N  atoms: 

/CHs.CH,\ 

N-CHs.CHs— N 

\CHa.CH^ 

Tiimethylene  diamin.  Diethylene  dUmin.  Triethylene  diamin. 

The  primary  diamins  only  are  acyclic  compounds.  They  have  the 
algebraic  formula:  N2CnH2n+4;  the  secondaiy,  N2CnH2n+2;  and  the 
tertiary,  N2CnH2n.  The  secondary  and  tertiary  diamins  are  not  known 
beyond  the  ethylene  compounds  and  are  cyclic  compounds  (see 
Piperazin). 

The  primary  diamins  are  obtained  (1)  by  the  reduction  of  the 
olefin  dicyanids.  Thus  ethylene  cyanid  yields  tetramethylene  diamin: 
CN.CH2.CH2.CN+4H2=H2N.CH2.CH2.CH2.CH2.NH2;  (2)  as  hydro- 
bromids,  by  heating  the  olefin  bromids  with  alcoholic  ammonia  to 
100°  underpressure:  BrCH2.CH2Br+2NH3=H3Br::N.CH2.CH2.N:: 
HaBr;  (3)  by  reduction  of  the  dinitroparaffins:  NO2CH2.CH2NO2+ 
6H2=H2N.CH2.CH2.NH2+4H20. 

The  diamins  form  crystalline,  insoluble  benzoyl  derivatives  when 
shaken  in  alkaline  solution  with  benzoyl  chlorid,  a  property  which 
they  share  with  polyatomic  alcohols  and  hexoses. 

Among  the  diamins  are  included  several  of  the  products  of  putre- 
faction known  as  ptoma'ins. 

Bthylenediamin — H2N.(CH2)2.NH2 — is  a  strongly  alkaline  liquid, 
boUing  at  116.5°  (241.7°  P.).     With  acetyl  chlorid  it  forms  diacetyl- 

CHa.NH.CO.CH3 
ethylene  diamin,  I  ,  which  is  decomposed  by  heat  with 

CH3.NH.CO.CHs 
formation  of  a  cyclic  amidin  base  (p.  388),  ethylene-ethenyl  amidin, 

CHs.NHv 
or  lysidin,  I  ^C.CHa  (p.  514). 

CHs.N    ^ 
25 


hbt 


MANUAL    OF    CHEMISTRY 


Trimethylenediamin  —  H2N,(OH2)3.NH2  —  is  said  to  have  been 
obtained  fmm  the  coltiires  of  the  comma  bacillus.  It  has  been  ob- 
tained synthetically  by  the  second  method  given  on  p.  385,  It  is  an 
jilkaline  iiquid,  boiling  at  135''  (275"  F.). 

Tetraniethyknediamin—  Putrescin  —  H2N,  (CH2)  «.NH3  —  is  pro- 
duced, along  with  the  cudaveriu,  during  the  putrefaction  of  muscnhir 
tissue,  interna!  organs  of  man  and  animals,  and  of  fish,  and  in  the 
culture  media  of  the  comma  bacillus  from  three  days  to  four  months. 
The  free  base  is  a  colorless  liquid  (solid  below  27°)  having  a  seminal 
odor,  which  absorbs  CO2  from  the  air  and  unites  with  acids  to  form 
erystalliue  salts »     It  is  not  actively  poisonous. 

P  entam  ethyl  en  ediamin^ —  Cadaverin  —  H2N.  (CH2)5  .NH2 —  is  iso- 
meric with  neuridin  and  is  produced  dnring  the  later  stages  of  puti*e- 
factkm  of  many  animal  tissues,  the  eholiu  disappearing  «s  this  and 
the  other  diamins  are  formed.  The  free  base  is  a  clear  syrupy  liquid, 
having  a  strong  disagreeaVile  odor,  resembling  that  of  couim,  boils  at 
175°,  and  fumes  in  air.  It  absorbs  CO2  rapidly,  with  formation  of  a 
crystalline  carbonate.  Its  salts  are  crystalline.  The  ehlorid  on  dry 
distillation  is  deeoraposed  into  ammonium  ehlorid  and  piperidin 
(p.  519). 

Hcxaniethylenedianiin'— H2N,{CH2)6.NH2 — is  formed  during  pu- 
trefaction of  muscular  tissue  and  pancreas.  It  is  a  crystalline  solid, 
fusing  at  40"*  (irM^°  F.)  and  boiling  at  195°  (383°  F. ) .  ^ 

Neuridin — CsHuN-i — a  diamin  of  nndeterniined  constitution,  iso- 
meric with  cadaverin,  is  produced,  along  with  cholin  {p.  383) »  during 
the  earlier  stages  of  putrefaetioii,  particuhirly  of  gelatiuoid  sub- 
stances, and  increases  in  quantity  as  putrefaction  advances,  while  the 
quantity  of  cholin  diminishes.  The  free  base  is  a  gelatinous  sub- 
stance, having  a  very  marked  seminal  odor,  readily  soluble  in 
water,  insoluble  in  alcohol  and  in  ether.  Its  ehlorid  is  crystal  line 
and  very  soluble  in  water.  It  seems  to  be  nou- poisonous  when 
pure, 

Saprin — CiHieN^—an other  diamin  of  undetermined  constitution. 
has  been  obtained  from  putrid  spleens  and  livers  after  three  weeks' 
putrefaction. 

Mydalein  is  still  another  putrid  product  of  undetermined  compo- 
sition, but  probably  a  diamin  containing  four  or  five  carbon  atoms, 
which  forms  a  difficultly  crystallizable,  hygroscopic  ehlorid,  which  is 
actively  poisonous.  Five  milligrams  administered  hjiiodermically  to 
a  cat  causes  death  after  profuse  diarrhoea  and  secretion  of  saliva,  vio- 
lent convulsions,  and  paralysis,  beginning  with  the  extremities  and 
extending  to  the  muscles  of  respiration. 

Other  diamins,  in  which  alkyls  are  substituted  for  the  remaining 
H  of  NH2,  are  formed  by  condeusatiou  of  secondary  amins  with  formic 


NITEOGEN    DERIVATIVES    OF    THE    PARAFFINS  387 

\ 

"aldehyde:  2tCn,),XIl+H.CHO=(CH3)2:N.CH*i.N:  (CHa)2+H4:)  and 
in  them  the  alkyls  may  be  like  or  unlike.  And  still  other  diainidoparaf* 
fins,  or  diamius  in  which  one  amido  group  is  attadied  to  a  terminal 
carbon  atom,  and  the  other  to  an  intermediate  one,  are  kn<nvn;  such 
as  1,  4  diamido  peutane:   CH3.CH(NH2).CH2.UH2.CH2.NH2. 

The  imins,  also  called  imids  (but  see  p.  408),  are  formed  by  the 
eubstitutiou  of  bivaleut  hydroearl>on  f!:roups  for  two  hydrogen  atoms 
in  a  single  molecule  of  ammonia ;  or  they  may  bo  considered  as  derived 
from  the  dibydrie  alcohols  by  substitution  of  the  iniiu  group,  (NH)^^ 
for  both  hydroxyls"  the  diimtns»  also  called  diamids,  by  the  substi- 
tution of  two  such  groups  for  four  hydrogen  atoms  in  two  molecules 
of  ammonia.  These  compoundt^  are  cyclic^  and  include  some  important 
members  of  the  aromatic  series. 

When  the  diammonium  clilorids  are  heated  ammonium  chlorid  is 
split  oflf,  and  an  imin  or  a  diimin  is  formed.  Thus  pipcridin  (p.  519) 
is  produced  from  pentamethylene  diamin;  and  piperazin  (p,  522) 
from  ethylene  diamin: 

Cm3N,CH,,CHi,CH2.CHaXH2.m3CI  =  NH4Cl+Cm2N<^^g*;^g^ 
2CIH3N  .CH2  XHa  .NH3C1=2NH4C1  +  Cm2N<^^^J  ;^|^])nH2C1 

CIt.2v 

Spcrmin^^CsHsN — probably   ethylene-imin,  I     ^NH,    has   been 

obtained  from  semen,  testicles,  ovaries,  prostatBi  thyrtid,  pancreas, 
and  spleen.  Its  phosphate  forms  crystals,  known  as  Leyden, 
Bottcher's,  or  Charcot's  crystals,  which  are  met  with  in  anatomical 
^^preparations  preserved  in  alcohol,  in  dried  semen,  in  sputa  and  nasal 
etions,  in  the  blood,  spleen,  and  other  organs  of  leucocythiemics 
'and  anffimies,  and  in  fasces.  A  substance,  probably  identical  with 
spermin,  is  also  found  in  the  cultures  of  the  comma  bacillus  on  beef* 
broth.  The  free  base  forms  crystals,  which  rapidly  absorb  carboa 
^dioxid  from  air,  are  readily  soluble  in  water  and  in  alcohol,  insoluble 
ether,  and  strongly  alkaline  in  reaction.  The  Charcot  crystals  are 
>Iuble  in  alcohol,  ether  and  chloroform,  difficultly  soluble  in  water^ 
'infiily  soluble  in  dilute  acids  or  alkalies. 

Glucosamins.^ — As  the  primary  monarains,  the  hydramins  and  the 
diamins  may  be  considered  as  derived  from  the  monohydric  and  diliy- 
dric  alcohols  by  substitution  of  NH2  for  OH  (p.  378),  so  similar  com* 
poQtidfl  may  be  derived  from  the  aldoses  and  ketoses  (p.  30y}. 

Chitosamin,  probably  d-glucosamin,  CH20H.(CHOH)3.CHNH2.- 
CHO,  was  first  extracted  from  chitiu  {p.  597),  and  from  certain  fungi. 
It  has  also  been  obtained  from  urine,  and  exists  in  protein  combina- 
tion, probably  in  an  amidopolysacoharid  form  (p.  309),  and  in  glyco- 
prot^ids   (p.  594).     It   forms    small,  colorless   crystals,  f.  p.   110°, 


388  MANUAL    OP    CHEMISTRY 

permanent  when  dry,  but  decomposing  in  solution,  dextrogyrousta]D 
=+44°.  It  forms  crystalline  salts  with  acids,  is  not  fermentable,  and 
is  converted  by  HNO2  into  a  nonfermentable  hexose,  C6H12O6,  called 
chitose.  It  reduces  the  salts  of  Ag,  Cu  and  Bi  to  the  same  extent  as 
does  glucose.  IsogluMsamin,  CH2NH2.CO.(CHOH)8.CH20H,  is  ob- 
tained, as  a  IflBvogyrous,  uncrystallizable,  reducing  syrup,  by  reduc- 
tion of  glucososazone  (p.  485).  Acrosamin  is  a  reducing,  optically 
inactive  glucosamin,  obtained  by  the  reduction  of  acrososazone. 

AMIDINS— AMIDOXIMS— HYDROXAMIC    ACIDS. 

The  amidins  contain  both  the  amido  group,  NH2,  and  the  imido 
group,  NH,  and  have  the  general  formula:  B'C^2^\  in  which  R  is 
any  univalent  hydrocarbon  radical. 

They  are  formed  by  heating  the  nitrils  (p.  393)  with  ammonium 
chlorid.  Thus  acetonitril  yields  acetamidin :  CHs.C  |  N+NH4C1= 
HCl+CHa.C^jJ^'.    They  are  also  formed  by  action  of  HCl  upon  the 

amids.  Indeed,  they  may  be  considered  as  being  derived  from  the 
amids  (p.  399)  by  substitution  of  NH  for  the  carbonyl  oxygen  : 

CHs.C^O^',  acetamid  :  CHs.C^h'*  acetamidin.     The  amidins  are 

monacid  bases,  very  unstable  when  free. 

The  amidoxims  are  derived  from  the  amidins  by  substitution  of 
OH  for  hydrogen,  e.  g.,  CHa.C^jj  oH»  ethenylamidoxim.  They  are 
very  unstable  compounds,  formed  by  the  action  of  hydroxylamin 
upon  nitrils  or  upon  amidins  (p.  409). 

Hydroxamic  acids  contain  the  oxim  group,  N.OH,  while  the 
amido  group  of  the  amidin  is  replaced  by  hydroxyl :  CHs.C^^g* 
acetohydroxamic  acid. 

GUANIDIN   AND    IIS    DERIVATIVES. 

Guanidin — Carbotriamin — CHsNa — was  first  obtained  by  oxidation 
of  guanin  (p.  534).  It  is  formed  (1)  by  heating  ethyl  orthocarbonate 
with  ammonia:  C(OC2H5)4+3NH3=HN:C:  (NH2)2+4CH3.CH20H; 
(2)  from  cyanogen  iodid  and  ammonia:  CNI+2NH3=HN:C:  (NH2)2 
+HI;  (3)  as  hydrochlorid  from  cyauaraid  and  ammonium  chlorid: 
CN.NH2+NH4C1=C1H2;N:C:(NH2)2.  Substituted  guanidins  may 
be  obtained  by  method  (3)  by  using  hydrochlorids  of  primary  amins: 

CN.NH,+H,N<CH3^HN:C<NH,g^^g^Cl 
Guanidin,  containing  the  group  .C^NH^  ^^  ^^  amidin.    It  may  also 


NITROGEN    DERIVATIVES    OP   THE    PARAFFINS  389 

be  considered  as  a  triamin,  derived  from  three  ammonia  molecules, 
HsN — C^I^^  It  is  related  to  amidocarbonic  acid,  to  urea  and  to 
psendonrea,  as  is  indicated  by  the  formnlaB: 

^^/NH,       o=C<NH.      ^^e<g|»      0=C<^» 

Chumldin.  Urea.  PseodoiirM.         Amido  earbonie 

•eid. 

It  is  a  crystalline  solid,  which  absorbs  CO2  and  H2O  from  the  air, 
andforms  crystalline  salts.  It  is  one  of  the  sources  from  which. hydrazin 
and  its  hydroxid  and  sulfate  are  most  conveniently  obtained.   It  is  first 

converted  into  nitroguanidin,  HN:C<^jjh^^     ^\    This  is  then  reduced 

.NHlNHj) 
in  presence  of  H2SO4  to  amidoguanidin  sulfate, HN :  G<C    #^3         which 

^N  — HSO4 

is  then  hydrolyzed  with  formation  of  ammonia,  carbon  dioxid  and 
hydrazin  sulfate:  H2N.N^h|'o^. 

Methyl-guanidin  —  Methyluramin— HN:C(NH2)NH(CH3)— was 
first  obtained  by  the  oxidation  of  creatin  and  of  creatinin  (see  below). 
It  has  also  been  obtained  as  a  product  of  putrefaction  of  muscular 
tissne  at  a  low  temperature  in  closed  vessels,  when  it  probably  results 
from  the  decomposition  of  creatin.  It  is  a  colorless,  crystalline,  deli- 
qnescent,  strongly  alkaline  substance,  and  is  highly  poisonous. 

The  relation  of  guanidin  and  methyl-guanidin  to  each  other  and 
to  creatin  and  creatinin  is  shown  by  the  following  formulsB: 

^^-^\NHa  *^-^\N(CH3)  .CH2.COOH 

Onanidin.  CreatiD. 

Hv-r/NH,  /NH CO 

^^•"^\NH(CH3)  HN=C<  I 

\N(CH3)CH2 
Methyl-guanidin.  Creatinin. 

Creatin — Methyl-guanidin  acetic  acid — C4H9N802+Aq — is,  as  is 
shown  by  the  above  graphic  formula,  a  complex  amido-acid  (p.  411). 
It  is  a  normal  constituent  of  the  juices  of  muscular  tissue,  brain, 
blood,  and  amniotic  fluid.  It  is  formed  synthetically  by  the  union 
of  methyl  glycocoU  (p.  414),  and  cyanamid  (p.  398) :  CH2(NH.CH8).- 

COOH+NC.NH2=HN=C<JJ^^H3).CH2.COOH. 

It  is  best  obtained  from  the  flesh  of  the  fowl,  which  contains  0.32 
per  cent.,  or  from  beef-heart,  which  contains  0.14  per  cent.  It  is 
soluble  in  boiling  H2O  and  in  alcohol,  insoluble  in  ether;  crystallizes 
in  brilliant,  oblique,  rhombic  prisms;  neutral;  tasteless;  loses  Aq  at 
100°  (212°  F.) ;  fuses  and  decomposes  at  higher  temperatures.  When 
long  heated  with  H2O,  or  treated  with  concentrated  acids,  it  loses 
H3O,  and  is  converted  into  creatinin.     Baryta  water  decomposes  it 


390  MANUAL    OP    CHEMISTRY 

into  sarcosin  and  urea.  It  is  not  precipitated  by  silver  nitrate,  ex- 
cept when  it  is  in  excess  and  in  presence  of  a  small  quantity  of  po- 
tassium hydroxid.  The  white  precipitate  so  obtained  is  soluble  in 
excess  of  potash,  from  which  a  jelly  separates,  which  turns  black, 
slowly  at  ordinary  temperatures,  rapidly  at  100°  (212°  P.).  A  white 
precipitate,  which  turns  black  when  heated,  it  also  formed  when  a 
solution  of  creatin  is  similarly  treated  with  mercuric  chlorid  and 
potash. 

Creatinin  —  Methyl -guanidin  acetic  lactam  —  C4H7N3O  — 113  —  a 
product  of  the  dehydration  of  creatin,  is  a  normal  and  constant  con- 
43tituent  of  the  urine  and  amniotic  fluid,  and  also  exists  in  the  blood 
and  muscular  tissue. 

It  crystallizes  in  oblique,  rhombic  prisms,  soluble  in  H2O  and  in 
hot  alcohol,  insoluble  in  ether.  It  is  a  strong  base,  has  an  alkaline 
taste  and  reaction;  expels  NH3  from  the  ammoniacal  salts,  and  forms 
well-defined  salti^,  among  which  is  the  double  chlorid  of  zinc  and 
creatinin  (C4H7N30)2ZnCl2,  obtained  in  very  sparingly  soluble, 
oblique  prismatic  crystals,  when  alcoholic  solutions  of  creatinin  and 
zinc  chlorid  are  mixed. 

Cruso-creatinin — C5HgN40 — is  an  orange -yellow,  crystalline  solid, 
alkaline  in  reaction;  Xantho-creatinin — C5H19N4O — is  in  yellow  crys- 
talline plates;  Amphi-creatinin— C9H19N7O4 — forms  yellowish -white 
prismatic  crystals.  These  are  basic  substances,  forming  crystalline 
ohlorids,  and  belonging  to  the  class  of  Icucomains,  which  include 
l)Hsic  nitrogen  compounds  produced  by  physiological  processes.  (See  p. 
oTl.)  They  are  obtained  from  the  juices  of  muscular  tissue,  and  from 
Liebig^s  meat  extract,  in  which  they  accompany  creatin  and  creatinin. 

H  YDRAZINS — H  YDR  AZIDS . 

The  hydrazins  are  derivatives  of  hydrazin  or  diamidogen,  H2N.NH2 
(p.  152),  by  substitution  of  aliphatic  or  aromatic  radicals,  alcoholic, 
phenolic  or  acid,  for  one  or  more  of  the  hydrogen  atoms  in  the  same 
way  as  the  amins  are  derived  from  ammonia.  There  are,  therefore, 
primary,  secondary,  tertiary  and  quarternary  hydrazins;  and  they  may 
be  symmetrical,  as  C2H5.HN.NH.C2H5  and  C6H5.HN.NH.C2I15.  or 
unsymmetrical,  as  C6H5.HN.NH2  and  (C2H5)2N.NH2.  The  aliphatic 
hydrazins  are  obtained  from  the  alkyl- ureas,  by  conversion  into 
nitroso- amins,  and  reduction.  Most  of  the  hydrazins,  some  of  which 
are  of  considerable  interest,  are  derivatives  of  phenyl -hydrazin,  CeHs.- 
HN.NH2,  and,  containing  a  cyclic  chain  Cello.  These  will  be  considered 
among  the  aromatic  compounds.  The  hydrazids,  corresponding  to  the 
amids,  contain  acidyls. 


NITROGEN    DEEIVATIVKS    OP    TOE    PARAFFINS 


3U1 


KITRILS— 'CYANOGEK    COMPOUNDS, 

Thesp  *inhstaiices  may  be  considered  either  as  compounds  of  the 
univalent  radit-al  cyanogen  (CN)',  or  as  paraffins,  CriH2ii+2i  in  which 
three  atoiii.s  of  hydrogen  have  l>een  replaced  by  the  trivaleut  N''''  atom, 
hence  mtrils,  compounds  of  N  with  the  trivaleut  radicals  CnH-in-i. 

Hydrogen  Cyanid— Fonnonifril — Cijftnogen  htfdrid — Hydrocyanic 
acid  — Prussic  acid  —  HC:N  —  exists  ready  formed  in  the  juice  of 
cassava,  and  is  formed  by  the  action  of  H2O  upon  bitter  almonds* 
cherry -laurel  leaves,  and  other  veij^etabie  products  containing  amyg- 
dalin,  a  gincosid,  which  is  decomposed  into  i^lucose,  benzoic  aldehyde 
(p.  466),  and  hjdrocyanic  acid,  wheu  warmed  with  water.  It  is  also 
formed  in  a  great  number  of  reactions;  by  the  passage  of  the 
electric  discharge  through  a  mixture  of  acetylene  and  nitrogen: 
HC  :  CH  +  Xo^^  2110  :  N ;  by  the  action  of  chloroform  on  ammonia: 
NH3  +  CHCl3=  3HC1  +  HCN;  by  the  distillation  of.  or  the  action  of 
HNO3  upon,  many  organic  substances;  by  the  decomposition  of 
<?yanid8  (see  Nitrils,  below). 

It  is  always  prepared  by  the  decomposition  of  a  eyanid  or  a 
ferrocyanid,  usually  by  acting  upon  potassium  ferrocyanid  with 
dilute  sulfuric  aeid^  and  distilling.  Its  preparation  in  the  pun- 
form  is  an  operation  attended  with  the  most  serious  danger,  and 
should  only  be  attempted  by  those  well  trained  in  chemical  manip- 
ulation. For  medical  uses  a  very  dilute  acid  is  required;  the  acid, 
hydro  cyan  i  cum  dil.  (U,  8.  Br  J  contains,  if  freshly  and  properly 
prepared,  two  per  cent,  of  anhydrous  acid.  That  of  the  French 
Codex  is  much  stronger  —  ten  per  cent. 

The  pure  acid  is  a  colorless,  mnbile  liquid,  has  a  penetrating  and 
xjharactcristic  odor;  sp,  gr,  0,705H  at  1"^  (44,6'^  F  J  ;  crystallizes  at 
—IS"*  (5°  PJ;  boils  at  26.5°  (79.7''  P.);  is  rapidly  decomposed  by 
exposure  to  light.  The  dilute  arid  of  the  U.  S.  l\  is  a  colorless 
liquid,  having  the  odor  of  the  acid;  faintly  acid,  the  reddened  litnjus 
returning  to  blue  on  exposure  to  air;  sp,  gr.  0.997;  10  grams  of 
the  acid  should  react  without  excess  w^ith  1.27  gram  of  silver  nitrate. 
The  dUute  acid  deteriorates  on  exposure  to  light,  although  more 
slowly  than  the  concentrated;  a  trace  of  phosphoric  acid  added  to 
the  solution  retards  the  decomposition. 

Most  strong  acids  decompose  HCN.  The  alkalies  enter  into  double 
decomposition  with  it  to  form  cyaoids.  It  is  decomposed  by  CI  and 
Br,  with  formation  of  cyanogen  chlorid  or  bromid.  Nascent  H  con- 
verts it  into  methylamin,  With  aldehydes  and  ketones  it  forms 
cyanhydrins  as  additive  products  (p.  397).  The  pu.e  acid  or  its  con- 
centrated solutions  readily  polymerize  on  contact  with  KCN  to  form 
i^olored  polymeres  and  one  which  is  crystalline  and  colorless.  (See 
Amido-malouonitril,  p.  395.) 


MIta 


392 


3IANUAL    OF    CHEMISTRY 


Anal3rtical  Characters. — (1)  With  silver  nitrate:  a  dense,  white 
ppt.;  which  is  not  dissolved  on  addition  of  HNO3  to  the  Liquid,  bnt 
dissolves  when  separated  and  heated  with  concentrated  HNO3;  solo* 
ble  in  solntions  of  alkaline  cyan  ids  or  thiosul  fates.  (2)  Treated 
with  NH4HS,  evaporated  to  dryness,  and  ferric  chlorid  added  to  the 
residue:  a  blood-red  color,  which  is  discharged  by  mercuric  chlorid. 
(3)  With  potash  and  then  a  mixtnre  of  ferrous  and  ferric  sulfates: 
a  greetiish  ppt.,  which  is  partly  dissolved  by  HCl,  leaving  a  pure 
dark -blue  precipitate.  (4)  Heated  with  a  dilute  solution  of  picric 
acid  and  then  cooled  :  a  deep* red  color.  (5)  Moisten  a  piece  of 
filter- p^per  with  a  freshly  prepared  alcoholic  solution  of  guaiac;  dip 
the  paper  into  a  very  dilute  sohition  of  CnS04,  and,  after  drjiug, 
into  the  liquid  to  be  tested.  In  the  presence  of  HCN  it  assumes  a 
deep -bh^  color.  (6)  Add  a  few  drops  of  potassium  nitrite  solution, 
then  two  or  three  drops  of  ferric  chlorid  solution,  and  enough  dilute 
H2SO4  to  turn  the  color  to  yellow.  Heat  just  to  boiling;  cool,  add 
a  few  drops  of  NH4HO,  filter,  and  add  to  the  filtrate  a  few  drops 
of  dilute,  colorless  amnioniura  sulf hydrate:  a  violet  color,  changing 
to  bine,  then  to  green  and  yellow  (p.  399). 

Toxicology.  —  Hydi'Ofiyanie  acid  is  a  violent  poison,  whether  it  be 
inhaled  as  vapor,  or  swallowed,  either  in  the  form  of  dilute  acid,  of 
soluble  cyanid,  or  of  the  pharmaceutical  preparations  containing  it, 
such  as  oil  of  bitter  almonds  and  cherrj^-laurel  water;  its  action  being 
more  rapid  wiien  taken  by  inhalation  or  in  aqueous  solution  than  in 
other  forms.  When  the  medicinal  acid  is  taken  in  poisonous  dose, 
its  lethal  effect  may  seem  to  be  prodoced  instantaneously;  nevertheless, 
several  respiratory  efforts  usually  are  mode  after  the  victim  seems  to 
be  dead,  and  instances  are  not  wanting  in  which  there  was  time  for 
considerable  voluntaiy  motion  between  the  time  of  ingestion  of  the 
poison  and  unconsciousness.  In  the  great  majority  of  cases  the 
patient  is  either  dead  or  fully  under  the  influence  of  the  poison  on 
the  anival  of  the  physician,  who  should,  however,  not  neglect  to 
apply  the  proper  remedies  if  the  faintest  spark  of  life  remain. 
Chemical  antidotes  are,  owing  to  the  rapidity  of  action  of  the  poison, 
of  no  avail,  althongh  possibly  chlorin,  recommended  as  an  antidote 
by  many,  may  have  a  chemical  action  on  that  j>ortion  of  the  acid 
already  absorbed.  The  treatment  indicated  is  directed  to  the  main* 
tenance  of  respiration;  cold  douche,  galvanism,  artificial  respiration, 
until  elimination  has  removed  the  poison.  If  the  patient  survive 
an  hour  after  taking  the  poison,  the  prognosis  becomes  very  favor- 
able; in  the  first  stages  it  is  exceedingly  unfavorable,  unless  the 
quantity  taken  has  been  very  small. 

In  eases  of  death  from  hydrocyanic  acid  the  odor  of  the  poison 
may  be  observed  in  the  apartment,  or  upon  opening  the  body.     In 


NITHOGEN    DERIVATIVES    OF    THE    PAKAFPINS 


393 


I 


I 


I 


cases  of  suicide  or  accident,  Ihe  vessel  from  wbicU  the  poison  has 
been  taken  will  usually  be  foiiiKl  near  the  body,  although  the  absence 
of  such  vessel  is  uot  proof  Ihat  the  ease  is  one  of  homieide. 

Notwithstanding  the  volatility  and  instability  of  the  poison,  its 
presence  has  been  detected  two  months  after  death,  although  the 
chances  of  separating:  it  are  certainly  the  better  the  sooner  after 
death  the  analysis  is  made.  The  search  for  hydroeyanic  acid  is 
combined  with  that  of  phosphorus;  the  part  of  the  distillate  con- 
taining the  more  volatile  products  is  examined  by  the  tests  given 
above.  It  is  best,  when  the  presence  of  free  hydrocyanic  acid  is 
suspected,  to  distil  at  first  without  acidnlating.  In  cases  of  sus- 
pected homicide  by  hydrocyanic  acid,  the  stomach  should  never  be 
opened  until  immediately  before  the  analysis. 

Cyanogen  Chlorids. — Two  polymeric  chlorids  are  known  i  Cyano- 
gen chlorid,  CNCl,  formed  by  the  action  of  CI  upon  anhydrous  HCN 
or  upon  HgCCNJa  in  the  dark.  It  is  a  colorless  gas,  condensing 
to  a  liquid  at  15^  (59°  P.);  intensely  irritating  and  poisonous. 
Tricyanogen  chlorid,  CaNsCla,  is  formed,  as  a  crystalline  solid,  when 
anhydrous  HON  is  acted  upon  by  CI  in  sunlight.  It  fuses  at  146°. 
(8ee  Cyanidin,  p.  537.) 

Cyanids. — The  most  important  of  the  simple  metallic  cyanids  are 
those  of  K  and  Ag  (pp.  228,  231,  also  p.  398). 

Nitrils. — ^The  hydrocyanic  esters  of  the  univalent  alcoholic  radi- 
cals are  called  acid  nitrils,  because  of  their  formation  from  the  am  ids 
(p.  400),  by  the  reaction  given  under  (3)  below.  Hydrocyanic  acid, 
bi*ing  produced  from  forraanxid,  isfornionttril ;  methyl  cyanid,  derived 
from  aeetamid,  is  acetonitril,  etc.  They  are  also  derivable  from  the 
ammonium  salt  of  the  acid  by  elimination  of  the  elements  of  two 
molecules  of  water.  Their  forraulro  maj^  be  derived  from  those  of  the 
acids  by  substitution  of  N  for  the  trivaleut  OOH  of  the  carboiyl. 
They  are  not  to  be  confounded  w^ith  the  acidyl  cyanids,  which  are  the 
nitrils  of  the  ketonic  acids  (p.  398). 

The  nitrils  are  produced:  (1)  By  heating  the  haloid  esters  (p. 
277)  with  alcoholic  solution  of  potassium  cyanid  at  100°:  CH3.CH2I 
+:iCN  =  CIi'j.CH2.CN+KL  (2)  By  distilling  a  mixture  of  potas- 
aiam  cyanid  and  the  potassium  salt  of  a  monoalkyl  sulfate.  Thus, 
ethyl  cyanid  is  produced  from  potassium  ethylsulfate:  KCN+8O4.* 
C^Hs.K^KaSOi+C^jHi.CN,  (3)  By  complete  dehydration,  by  the 
action  of  P2O6,  of  the  amnioniacal  salt  of  the  acid,  or  of  its  amid 
(p.  400).  Thus  acetonitril  is  obtained  from  ammonium  acetate: 
CIIi.COO(NH4)=-CPl3.CN+2H20;  or  from  aeetamid:  CH3.CO.NH2 
=CH3.CN+H20.  (4)  By  the  action  of  oeidyl  chlorids  upon  silver 
c^'anate.  Thus,  with  acetyl  chlorid,  methyl  cyanid  is  formed; 
CXOAg+CIIa.CO.Cl -=  AgCl+C02+CH3.CN. 


394 


MANITAL    OP    CHEMISTRY 


The  nitrils  eotnbine  with  naHcetit  hydrugeu  to  form  priniary 
amins.  Thus  aeetoiiitril  forms  ethylamiii:  CH3.CN+2H'_*=C2H5.XH2, 
Hydmting  agents  nnjvert  them  iuto  the  iiiumouium  salts  of  the  eor- 
responding  acids.  Thus  ainnioniurn  propiouate  is  derived  from  ethyl 
€yanid:  r2rT:.CX+2n20=C-iH:>.COO(NIl4).  Or,  when  acted  upon  by 
concentrated  sulfuric  acid,  hydrogen  peroxid,  or  concentrated  Irv  dro* 
chloric  acid,  they  take  up  one  molecule  of  water  and  form  amids 
(p,  4t»0).  Thus  aeetonitril  forms  acetamid;  CH3.CN+H20  =  CH3.- 
CO.NHs.  The  nitrils  al»ove  aeetonitril  readily  polymerize  to  form 
alkyl  paratriazitis  (p.  537). 

Methyl  Cyanid— Acctonitril^CHa.CN — is  a  colorless  liquid,  h.  p. 
81.6°,  having  an  agreeable  odor,  sparingly  soluble  io  water,  obtained 
by  distilling  amnjoiuuni  acetate  or  aectamid  with  P2O5. 

The  isocyanids»  carbylamins,  rir  carbamins  are  isoraeres  of  the 
nitrils,  which  differ  frora  the  latter  in  constitution  in  that,  in  the 
nitrils,  the  nitrogen  is  trivalent,  and  tlie  alkyl  group  is  in  union  with 
carbon,  e.  g.,  methyl  cyanid,  N=C'^CH;j,  >vhile  in  the  carbylnmins 
the  nitrogen  is  quinquivalent,  and  the  alkyl  is  in  union  with  nitrogen, 
e,  g.,  methyl  isocyanid,  C^N — Clin.  The  difference  iu  constitution 
between  the  nitrils  (alkyl  cyanids)  and  the  alkyl  isocyanids  is  shown 
by  the  difference  iu  their  behavior  with  hydrating  agents.  While  the 
cyanids  yield  the  ammonium  salts  of  the  corresponding  acids;  CEIa.* 
l'H2.CN  +  2H20=CiT:i.CHt..COO(Nn4),  the  isocyanids  are  split  into  a 
lirirnary  nmin  and  ftunnie  acid:  CH:H.CH:..NC+2H20=Cfi3.CH2,XH2 
+  I1.C00H. 

The  isocyanids  are  formed:  (1)  by  the  action  of  a  primary  mona- 
inin  on  chloroform  in  the  presence  of  caustic  potash.  Thus  methyl 
isocyanid  is  derived  from  metbylamiu  :  CH3..\nij+CHCl3=3HCl+ 
NC.CHa.  (pp.  279,  380);  (2)  by  the  action  of  alkyl  iodids  upon  silver 
cyanid:  CHal+AgCN^Agl+NCCHa. 

Methyl  Isocyanid — Mefhyl  carbifhim in — IsoaceionifHl — CH3.NC — 
is  a  colorless  liquid,  b.  p.,  58^,  having  a  disagreeable  odor,  and  giv 
lug  off  highly  poisonous  vapor.     It  is  fonned  by  the  reactions  given 
above,  and  is  said  to  exist  in  the  venom  of  toads. 

Phenyl  Isocyanid — Isobenzonitril — C0H5.NC — is  a  colorless  liquid, 
not  boiling  without  decomposition,  having  an  intensely  disagreeable 
odor,  whose  formation  is  utilized  in  a  test  for  chloroform  (p.  279). 

Both  nitrils  and  isonitnls  combine  with  the  hydracids  to  form 
<?rystalline  salts,  decomjiosable  by  water;  the  latter  much  more  en- 
ergetically  than  the  former.  They  are  all  volatile  liquids;  the  nitrils 
having  ethereal  odors  when  pure,  the  isonitrils  odors  which  are  very 
powerful  and  disagreeable. 

Nitrils  of  Dicarboxylic  Acids. — Two  nitrils  are  derivable  from  each 
acid  of  this  series,  one  being  an  u(^id  nitril,  or  nitrilic  acid,  the  other  a 


NITR03EN    DERIVATIVES    OF    THE    PARAFFINS  395 

dinitril,  or  dicyanid.  T\vj  iiitrilic  acids  are  cyano-fatty  acids,  aud  the 
dinitrils,  beyond  the  first,  are  the  alkylen  dicyanids.  Correspouding 
to  nialoaie  acid  there  exists  also  a  cyauomalonic  ester,  iu  which  the 
CN  is  substituted  in  the  CH2  group.    (See  p.  361)  : 

COOH  CN  CN  COOCCaHs) 

II  II 

CHj  CH2  CH2  CH.CN 

I  I  I  I 

COOH  COOH  CN  COOCCsHfi) 

Malonle  add.       Oyanoacetic  acid.    Methylene  cyanld.       Cyanomalonic  ester. 

The  nitrilic  acid  of  oxalic  acid  is  only  known  in  its  esters;  its  di- 
nitril  is  dicyanogen,  which  differs  from  the  alkylen  dicyanids,  which 
are  its  superior  homologues,  in  containing  no  hydrocarbon  group. 

Cyano-fatty  Acids — include  not  only  the  nitrilic  acids,  in  which 
the  CN  is  in  a  terminal  group,  but  also  compounds  such  as  a  cyano- 
propionic  acid,  CH2.CHCN.COOH. 

The  nitrilic  acids  are  obtained  from  the  monochloro- fatty  acids: 
CH2Cl.COOH+KCN=CH2CN.COOH+KCl.  When  heated  they  are 
decomposed  tonitrils  and  carbon  dioxid:  CH2CN.COOH=CH3.CN+ 
CO2.  By  acids  and  alkalies  they  are  hydrated  to  dicarboxylic  acids: 
CH2CN.COOH+2H20=COOH.CH2.COOH  +  NH3.  With  ammonia 
they  produce  amids  (p.  400).  Thus  cyanacetamid  is  formed  from 
cyanacetic  acid:  CH2CN.COOH+NH3=CN.CH2.CONH2+H20. 

Dicyanogen — CN.CN — is  prepared  by  heating  mercuric  cyanid, 
and  is  also  formed  by  passing  an  electric  arc  between  carbon  points 
in  an  atrgosphere  of  nitrogen. 

It  is  a  colorless  gas,  has  a  pronounced  odor  of  bitter  almonds: 
sp.  gr.,  1.8064  A.  It  burns  in  air  with  a  purple  flame,  giving  off  N 
and  CO2.  It  is  quite  soluble  in  water,  but  the  solutions  soon  turn 
brown,  and  then  contain  ammonium  oxalate  and  formate,  urea,  and 
hydrocyanic  acid.  The  brown  color  is  due  to  the  formation  of  azul- 
mic  acid,  C4Hr,Nr,0. 

The  alkylen  dicyanids  are  obtained :  ( 1 )  from  the  alkylen  bromids : 
CH2Br.CH2Br  +  2KCN  =  CN.CHo.CH2.CN  +  2KBr;  (2)  by  dehy- 
dration  of  the  amids  of  cyano-fatty  acids:  CN.CH2.CO.NH2=CN.CH2.- 
CN+H2O.  By  nascent  hydrogen  they  are  converted  into  diarains  (p. 
385);   and  by  hydrolysis  into  dicarboxylic  acids  (p.  335). 

Malononitril— }f ethylene  cyanid — CN.CH2.CN — is  obtained  from 
cyanacetamid  by  (2)  above.  It  would  be  isomeric  with  the  unknown 
cyanoform,  CH(CN)3.  The  crystalline  polymere  of  hydrocyanic  acid 
(p.  391)  is  presumed  to  be  amido-malononitril,  as  it  splits  on  hydroly- 
sis to  amidoacetic  acid,  carbon  dioxid  and  ammonia:  CN.CH(NH2).- 
CN+4H20=CH2(NH2)  .COOH+CO2+2NH3. 

Nitrils  of  Carbonic  and  Thiocarbonic  Acids. — These  constitute 
the  oxygen  and  sulfur  compounds  of    cyanogen.    Thus  cyanic  acid 


39C  MANUAL    OP    CHEMISTK/ 

is  the  nitril  of  carbonic  acid:  C08H(NH4y=CONH+2H20,  and 
thiocyanic  acid  that  of  thiocarbonic  acid  :  C02SH(NH4)=CSNH+ 
2H2O. 

Three  structural  formuIsBof  these  compounds  are  possible:  N=C.- 
OH,  0=C=N.H,  and  C^N.OH.  The  first  structure  is  that  of  the 
normal  cyanic  and  thiocyanic  acids,  the  second  that  of  the  isocyanates 
and  isothiocyauates,  the  third  that  of  fulminic  acid. 

Cyanic  Acid — NC.OH — is  obtained  by  distillation  of  cyanuric 
acid,  or,  in  its  salts,  by  calcining  the  cyanids  in  presence  of  an  oxi- 
dizing agent,  or  by  the  action  of  dicyanogen  upon  solutions  of  the 
alkalies  or  alkaline  carbonates. 

It  is  a  colorless  liquid,  only  stable  below  0°  (32°  P.) ;  has  a  strong 
x)dor,  resembling  that  of  formic  acid;  and  is  soluble  in  water;  gives 
off  an  irritating  vapor;  is  vesicating  to  the  skin;  and  is  changed  by  ex- 
posure to  air  into  its  polymere,  cyamelid,  a  white,  porcelain -like  solid. 

Cyanuric  Acid — Tricyanic  acid — Trioxycyanidin  (p.  537) — HO.- 

^\N=C(OH)/N  —  is  produced  by  dry  distillation  of  uric  acid;  by 
the  action  of  heat  or  of  CI  upon  urea;  by  heating  tricyanogen  chlorid 
or  bromid  with  water  or  with  alkalies.  It  forms  colorless  crystals,  odor- 
less, almost  tasteless,  feebly  acid,  rather  soluble  in  water.  It  is  tribasic. 
It  may  be  dissolved  in  strong  H2SO4  or  HNO3  without  decomposition, 
but,  when  boiled  with  acids  or  alkalies,  it  is  decomposed  into  carbon 
dioxid  and  ammonia;    and,  when  distilled,  into  cyanic  acid. 

The  ordinary  potassium  and  ammonium  cyanates  are  regarded  as 
isocyanates,  salts  of  isocyanic  acid,  or  carbimid,  OrCrNfi.  The 
ammonium  salt,  0:C:N(NH4),  is  converted  into  its  isomere,  urea, 
H2N.CO.NH2,  by  evaporation  of  its  solution.  The  isocyanic  esters 
serve  for  the  generation  of  the  alkyl  ureas  (p.  406). 

Fulminic  Acid — Carbyloxim — C=N.OH — is  a  strongly  acid  sub- 
stance, having  the  odor  and  poisonous  qualities  of  hydrocyanic  acid, 
whose  Ag  and  Hg  salts  are  formed  by  the  action  of  nitrous  acid  upon 
alcohol  and  silver,  or  mercuric,  nitrate.  Mercuric  fulminate,  or 
fulminating  mercury,  crystallizes  in  white,  soluble  needles,  and  ex- 
plodes violently  upon  shock.  It  is  used  in  percussion  caps,  primers 
and  cartridges.  Silver  fulminate  is  more  violently  explosive  than 
the  mercurial  salt.  Fulminating  gold  is  not  a  fulminate,  but  auro- 
amidoimid,  Au(NH)NH2+3H20. 

Fulminuric  Acid — CN.CH(N02).C^nh  —  metameric  with  cya- 
nuric, and  polymeric  with  cj'anic  and  isocyanic  acids,  is  a  deriva- 
tive of  tartronic  acid,  COOH.CHOH.COOH  ;  whose  alkali  salts  are 
formed  by  boiling  solutions  of  alkaline  chlorids  with  mercuric 
fulminate. 

Thiocyanic  Acid — Sulfocyanic  acid — Cyanogen  sulfhydrate — N= 


r^SITROGEN    DERIVATIVES    OF    THE    PARAFFINS 


397 


C.SH — is  obtained  by  decomposition  of  its  salts,  which  are  formed  by 
boiliog  solutions  of  the  cyauids  with  sulfur;  by  the  action  of  dieya- 
*  nogen  upon  the  metallic  sulfide ^  and  in  several  other  ways. 

The  free  acid  is  a  colorless  liquidi  crystallizes  at  ^^12.5*^  (9.5°  FJ , 
acid  in  reaction.  The  proininent  reaction  of  the  acid  and  of  its  salts 
is  the  formation  of  a  deep -red  color  with  the  ferric  salts;  the  color 
being  discharged  by  mercuric  chlorid  sohition. 

Thiocyanates  exist  in  the  human  saliva  and  in  the  stomach -con- 
tents, in  small  amount.     The  free  acid  is  poisonous. 

Isothtocyanic  Esters — Mnstard  oUa — Isothiocyanic  acid,  SrC:- 
NH,  is  not  known  in  the  fi*ee  state.  Its  esters  are  called  mustard 
oils,  from  the  most  important  of  the  class,  allyl  isothiocyanate 
(p.  432),  which  is  the  essential  oil  of  mustard. 

The  mustard  oils  are  obtained  :  (1)  by  mixing  ether  solutions  of 
primary  arains  and  carbon  dtsulfid,  and  evaporating  the  solutions,  the 
arain  salts  of  alkyl  dithiocarbamic  acids  are  formed  (p.  405)  r  CS2+ 

2C3H$.XH2~SC\  flfT^H,.r^H.\-  ^^  boiling  aqueous  solutions  of  these 
with  AgNOs,  Fe2Clfl  or  HgCls*  the  metallic  sulflds  are  precipitated, 
and  hydrogen  sulfid  and  the  mustard  oils  are  formed,  the  latter  dis- 
tilling over.     The  reaction  takes  place  in  two  stages  : 


ap/NH.CjHft 
**^\S(NH,.C5H5) 

EtbylftwcDoniaiii 
cthjrit  h  i  Dcmr  bacn  Hie . 

^**^\SAg 


Agm,=S€(^f^^^     + 


8Uv«r 
nltrftte. 


aiKer 
ethsrldtthiocii  rb  am  ait« . 


NO,.N^^'g^,  and 

Ethylnmniouium 


^         AgtS    +    HaS 


-h     2SC:N.CjHs 
Ethyl  lao«yAti*l«. 


Hoffmann'  s  test  for  the  primary  amins  (p,  380)  is  based  upon 
I  these  reactions. 

The  mustard  oils  are  liquids,  insoluble  in  water,  giving  oflf  vapors 
of  penetrating  odor  and  irritating  to  the  eyes.  When  heated  with 
water  under  pressure  to  200^  {392°  F,},  or  with  hydrochloric  acid  to 
100°  (212*^  F.),  they  are  decomposed  into  carbon  dioxid,  hydrogen 
sulfid  and  amins  r  8C:N.C2Hs+2H20=C02+SH:>+NIl2.C2H5.  Heat- 
ing with  dilute  H2SO4  decomposes  them  into  amins  and  carbon  oxy- 
sulfid,  COS.  With  nascent  hydrogen  thej-  yield  thioformaldehyde 
and  a  primary  amiu:  8C:N,C2H5+2H2=H.CSH+NH2.C2H&.  Heated 
with  monocarboxylic  acids  they  form  carbon  oxysulfid,  esters,  and 
inonamids  (p.  399)  :  SC: N.CiH5+2CH3. COOK— COSH- CHa. COO. • 
CaH^+NHs.CHa.CO.  Their  alcoholic  solutions,  when  boiled  with 
HgO,  yield  isocyanic  esters,  which  are  converted  by  water  into  the 
corresponding  compound  ureas. 

Nitriis  of  the  Oxyacids.— The  nitrils  of  the  a -acids  of  the  oxy- 
neetic  series  (p.  339)  are  also  called  cyanhydrins,  or  oxycyanids,  and 
b^ar  the  same  relation  to  the  acids  as  exists  between  the  acids  of  the 
acetic  series  and  Mieir  nitr"' 


398 


MANUAL 

OF 

CHEMISTRY 

CH3.COOH 

CH3.CN 

Acetic  Mid. 

Aeetonitril. 

CH3.CHOH.COOH 

CH3.CHOH.CN 

o-laetie  add. 

Lactic  nitril. 

They  axe  formed  as  additive  products  between  hydrocyanic  acid 
and  the  aldehydes  and  ketones:  HCN+CH3.CHO=CH3.GHOH.CN, 

and  HCN+CH3.CO.CH3=cH3/C\OH.  By  hydration  they  yield  the 
corresponding  acid  and  ammonia  :  CH3.CHOH.CN+2H20=CH3.- 
CHOH.COOH+NH3.  These  reactions  are  utilized  in  the  synthesis 
of  the  oxy acids  (p.  339). 

Nitrils  of  the  Ketone  Acids. — These  are  the  cyanids  of  the 
acidyls,  as  the  nitrils  are  the  cyanids  of  the  alkyls,  and  are  formed 
by  heating  the  acidyl  chlorids  with  silver  cyanid.  Thus  acetyl  cyanid 
is  produced  from  acetyl  chlorid  :  CH3.CO.Cl+AgCN=CH3.CO.CN+ 
AgCl;  or  by  dehydration  of  the  aldoxims  (p.  409)  of  the  a-aldehyde 
ketones.  Thus  oximido- acetone  yields  acetyl  cyanid:  CH3.CO.CH:- 
N.OH=CH3.CO.CN+H20.  They  are  unstable,  and  are  decomposed 
by  water  into  hydrocyanic  acid  and  their  corresponding  acids:  CH3.- 
CO.CN+H20=CH3.COOH+CNH. 

Cyanamid — CN.NH2— is  the  nitril  of  carbamic  acid  (p.  402): 
OC:NH2.0.NH4.— 2H20=CN.NH2.  It  is  formed  by  the  action  of 
cyanogen  chlorid  upon  ammonia:  CNC1+2NH3=NH4C1+CN.NH2; 
or  by  the  action  of  thionyl  chlorid  upon  urea:  NH2.CO.NH2+SOCU 
=CN.NH2+S02+2HC1.  It  forms  colorless  crystals,  soluble  in  water, 
alcohol  or  ether.  Corresponding  to  it  are  substituted  cyanamids^ 
which  may  be  formed  by  using  a  primary  amin  in  place  of  ammonia 
in  the  above-mentioned  method  of  preparation:  CNCI+2NH2.CH3 
=NH3.CH3.C1+CN.NHCH3.    Heated  with  ammonium  chlorid  it  forms 

guanidinhydrochlorid:  CN.NH2+NH4C1=H3C1N.C^^H,-  Hydrating 
agents  convert  it  into  urea:   CN.NH2+H20=H2N.CO.NH2. 

Metallocyanids. — The  metallic  compounds  of  cyanogen,  the  cya- 
nids, may  be  divided  into  three  classes:  (1)  the  simple  cyanids,  such 
as  potassium,  silver,  or  mercuric  cyanid.  which  resemble  in  consti- 
tution and  general  characters  the  ohlorids,  bromids  and  iodids;  (2) 
the  double  cyanids,  such  as  AgK(CN)2,  or  HgK2(CN)4,  which  are 
constituted  like  other  double  salts.  These  salts  have  crystalline 
forms  and  solubilities  of  their  own,  independent  of  those  of  the  sim- 
ple cyanids  of  which  they  are  made  up.  They  are  readily  decomposed 
by  cold  acids,  with  liberation  of  hydrocyanic  acid  ;  (3)  compound 
cyanids,  or  metallocyanids,  in  which  the  cyanogen  groups  are  more 
intimately  attached  to  the  metal,  in  such  manner  that  the  ordinary 
analytical  characters  of  the  metals  are  completely  masked;  and  when 
they  are  decomposed  by  cold  acids  hydrocyanic  acid  is  not  liberated. 


NITROGEN    DERIVATIVES    OP    THE    PARAFFINS  399 

but  a  complex  metallohydrocyanic  acid,  corresponding  in  constitution 
to  the  salt.  The  metals  entering  into  the  composition  of  the  metal- 
locyanids  are  iron  (ferro-  and  ferricyanids),  cobalt  (cobalticyanids), 
and  platinum  (platinocyanids) ;  also  chromium  and  manganese  in  the 
ic  form. 

The  metallocyanids  are  considered  as  derivatives  of  two  hypotheti- 
cal acids,  polymeres  of  hydrocyanic  acid:  dihydrocyanic  acid  and  tri- 
hydrocyanic  acid  (see  Paratriazin,  p.  537) ,  which,  in  the  hydrometallo- 
eyanic  acids  and  their  salts,  are  combined  with  the  constituent  metal » 
with  loss  of  hydrogen,  as  shown  in  the  following  formulae: 

H— C=N  H-C=N C— H 

II  I  II 

N=C— H  N=CH— N 

Dihydrocyanic  mcid.  Trihydrocyanic  acid. 

p^/CsNa.Kj                           *,®\C3N3.K2  px/C.Na.H 

'®\C3N3.K2                            ^'-/CsNa.K  ^XC^Na.H 
^^NCaNs.Kj 

Potassiam                                        Potassium  Hydroplatinocyanie 

ferrocyanid.                                      feiricyanid.  acid. 

Hydronitroprussic  Acid — Pe(CN)5(NO)H2 — contains  the  nitroso 
gp"oup  NO,  and  is  produced  when  potassium  ferrocyanid  is  acted  upon 
by  uitric  acid.  Its  sodium  salt,  sodium  nitroprussid,  is  formed  by 
ueutralizing  the  acid  with  sodium  carbonate.  It  forms  brilliant  red 
prisms;  and  is  used  as  a  test  for  sulfids,  with  which  it  forms  a  violet 
color.    (See  test  No.  6,  Hydrocyanic  acid,  p.  391.) 


AMIDS. 

These  compounds  are  similar  in  constitution  totheamins  (p.  377,) 
from  which  they  differ  in  that  the  radicals  substituted  in  ammonia  are 
acidyls  in  place  of  alkyls:    N^^^•^°^  ^^CO.cn^),^^  ^^^^  ^^^^^ 

Like  the  amins  they  are  classified  into  monamids,  diamids,  tri- 
amids,  according  as  they  are  derived  from  one,  two  or  three  molecules 
of  ammonia. 

Mixed  amids  are  also  known,  produced  by  the  substitution  of  acid 
radicals  for  the  remaining  hydrogen  of  the  primary  and  secondary 
amins,  e.  g.,  diethyl  acetamid:  CH3CO(C2H5)2N. 

MONAMIDS — AMIC    ACIDS — IMIDS. 

Like  the  monamins,  the  monamids  are  primary,  secondary,  or 
tertiary,  as  they  contain  one,  two  or  three  substituted  radicals. 

The  primary  monamids  corresponding  to  the  monocarboxylic  acids 
may  also  be  considered  as  being  derived  from  those  acids  by  substi- 


400  MANUAL    OP    CHEMISTRY 

tution  of  NH2  for  the  OH  of  the  group  COOH;  as  the  amius  are 
derivable  from  the  alcohols  by  substitution  of  NH2  for  OH  iu  CH2OH, 
CHOH  or  COH.  Thus  acetamid,  CH3.CO.NH2  is  derived  fi-om  acetic 
acid,  CH3.CO.OH. 

The  primary  monamids  are  formed:  (1)  by  the  action  of  heat 
upon  the  ammonium  salt  of  the  acid,  with  elimination  of  the  elements 
of  one  molecule  of  water:  CH3.COO(NH4)=H20+CH3.CO.NH2.  It 
will  be  remembered  that  the  nitrils  (p.  393)  are  derived  from  the 
amraoniacal  salts  by  elimination  of  two  molecules  of  water:  CH3.- 
COO(NH4)=2H20+CH3.CN;  (2)  by  addition  of  H2O  to  the  uitrils. 
Thus  hydrogen  peroxid  in  alkaline  solution  converts  acetonitril  into 
acetamid:  2CH3.CN+2H202=2CH3.CO.NH2+02;  (3)  by  the  action 
of  ammonia  upon  esters.  Thus,  ethyl  acetate  and  ammonia  produce 
acetamid  and  ethylic  alcohol:  CH3.COO(C2H5)+NH3=CH8.CO.- 
NH2+CH3.CH2OH;  (4)  by  the  action  of  an  acidyl  chlorid  upon  dry 
ammonia.  Thus,  acetamid  is  produced  by  acetyl  chlorid:  CH3.CO.- 
CI+2NH3  =NH4C1+CH8.C0.NH2. 

The  secondary  monamids  are  obtained:  (1)  by  the  action  of  acidyl 
chlorids  upon  the  primary  monamids.  Thus,  diacetamid  is  produced 
from  monacetamid:  CH3.CO.NH2+CH3.CO.Cl=HCl+(CH8CO)2NH; 
(2)  by  the  action  of  hydrochloric  acid  upon  the  primary  monamids  at 
high  temperatures  ;  2(CH8.CO.NH2)+HCl=NH4Cl+(CH3CO)2NH. 

The  tertiary  araids  of  this  series  have  been  imperfectly  studied. 
Some  have  been  obtained  by  the  action  of  acidyl  chlorids  upon  me- 
tallic derivatives  of  secondary  amids:  (CH3.CO)2NaN+CH3.CO.CI= 
(CH3.CO)3N+NaCl;  or  by  the  union  of  anhydrids  and  nitrils  at  200® 
(392°  F.) :  CH3.CN+(CH3.CO)20=(CH3.CO)3N. 

The  primary  monamids  of  the  fatty  acids  are  Solid,  crystallizable, 
neutral  in  reaction,  volatile  without  decomposition,  mostly  soluble  in 
alcohol  and  ether,  and  mostly  capable  of  uniting  with  acids  to  form 
compounds  similar  in  constitution  to  the  ammouiacal  salts:  H2N.CO.- 
CH3+HN03=(H3N.CO.CH3)N03.  They  are  capable  of  uniting  with 
H2O  to  form  the  ammoniaeal  salts  of  the  corresponding  acids:  H2N.- 
CO.CH3+H20=CH3.COO(NH4),  and  with  the  alkaline  hydroxids  to 
form  the  metallic  salts  of  the  corresponding  acids  and  ammonia: 
H2N.CO.CH3+KHO=CH3.COOK+NH3.  They  are  converted  into 
amius  containing  one  atom  of  carbon  less  than  themselves  by  the 
action  of  bromin  and  alkali  (p.  379).  The  secondary  monamids, 
containing  two  radicals  of  the  fatty  series,  are  acid  in  reaction,  and 
their  remaining  atom  of  extra -radical  hj'drogen  may  be  replaced  by 
an  electro -positive  atom. 

Formamid— CHO.NH2 — 45 — is  a  colorless  liquid,  soluble  in  H2O 
and  in  alcohol,  boils  at  192M95°(377.6°-385°  F.),  suffering  partial 
decomposition,  obtained  by  heating  ethyl  formate  with  an  alcoholic 


AMIDS    OF    DICARBOXYLIC    ACIDS 


f  401 


ition  of  araraonia,  or  by  tlie  dry  distillatiou  of  mnnioiiiinii  formate, 
lit  is  decomposed  by  debydratiiig  ageuts,  witb  furmutiini  of  bydro- 
eyanic  actd:     H2N(H.CO)=IICX+n20.     Mercury  formamid  is  ob- 
tained in  solution   by  gently  heating  fresbly* precipitated   merenric 
oxid  with  H2O  and  formaraid. 

Under  tbe  name  chloral  am  id  a  componnd,  formed  by  the  union  of 

''OH 

r^bloral  and  formamtd,  and  having  tbe  eonstitution,  CCl3.CH<  .^-ji  ^.^iq^ 

'"has  been  used  as  a  hypnotic.  It  forms  colorless,  odorless,  faintly 
bitter  crystals*  fusible  at  115°  (239°  FJ»  sparingly  soluble  in  water. 
It  is  decomposed  by  alkalies,  chloroform  and  ammonia  being  among 
the  products  of  the  decomposition.     It  is  not  affected  by  acids. 

Chloralimid — CCU-C^h    —is  another  related  derivative,  formed 

by  the  action  of  ainmoTiium  aeelate  upon  chloral  hydrate,  or  by  heat- 
ing chloral  ammonia.  It  is  a  crystalline  solid,  sparingly  soluble  in 
water,  readily  soluble  in  ether  and  in  alcohol.  When  beatt^d  to  180'^ 
(365°  F.)  it  is  decomposed  into  chloroform  and  formamid. 

Acetamid — CII;j.CO.NHL'^-is  (djtained  by  heatiug,  under  pressure, 
a  mixture  of  ethyl  acetate  and  ammonium  hydroxid,  and  purifying  by 
cll^tillation.  It  is  solid,  crystalline,  very  soluble  in  H2O,  alcohol,  and 
ether;  fuses  at  82''  (179.6°  F.);  boils  at  222°  (43L6°P.)  ;  has  a 
i^weetish,  cooling  taste,  and  an  odor  of  mice.  Boiling  potassium  by 
^droxid  solution  decomposes  it  into  potassium  aeetate  and  ammonia. 

Bphoric  anhydrid  deprives  it  of  H2O,  and  forms  with  it  acetonitril 
or  methyl  cyanid :  n,X.C0.rHi--CH3.CN+H>0. 

Alkyl-amids — are  eompounds  similar  in  sfrueture  to  the  seeondary 
and  tertiary  monamins  and  monamids,  but  containing  both  alkyls  and 
acidyls.  They  are  furme^l:  (1)  by  the  a**tion  of  esters  upon  amins. 
Thus  ethylacetamid  is  formed  from  ethyl  acetate  and  ctl]\lamin: 
CHa.COOaWf,)  +  H2X. (C2H5)  =  (CHa.CO) .HN. (C2H.O  +  C^llv-OH  ; 
(2)  from  acidyl  balids  nnd  uminsr  Cll.J'Od-f  21^2^^((^H:,)  =  (^H3.- 
^0)-H^^  (CWr.)  +  riHnN((^2H:J  :  and  2HX:  ((^11:.)^+ riUrOCI  = 
(CHj.rO).X^U^H:J2+t1H2N:fr2H5Ks  (3)  from  the  isoeyanids  and 
ffttty acids:  2CH3.COOH+CN\CH3=(H.CO) .HN.CH3+  (0Ha.CO)2O. 


AMIDS    OF    DICARBOXYLIC    ACIDS. 

As  the  hydramins,  the  diamins  (p.  382)  and  the  irains  (p.  387) 
arc  all  derivable  from  the  dihydric  alcobolri,  by  snbgtitntion  of  NIl^ 
f4>r  OH  in  tbe  firnt,  of  2NHa  for  201i  in  the  second,  and  of  Nil  for 
20H  in  the  bii^t,  so  amic  acids,  diamids,and  imids  are  correspondingly 
derived  from  the  dicarboxylio  acids: 

COOH  CONH3  CONH:t  CDs 

1  I  I 

COQH  COOH  CONH2 

Oxalic  Acid.  OxAtnlc  ncid,  Ol*mi(i. 

as 


I  )nh 

CO'^ 
Oximld. 


402  MANUAL    OP    CHEMISTRY 

and,  recognizing   that  carbonic   acid  is   a   pnre  dicarboxylic  acid, 
although  not  a  member  of  the  oxalic  series,  we  have: 

0C<8i  KSh  0^<Sk  OC:NH 

Carbonic  acid.  C&rbamic  acid.  Carbamid.  Carbimid. 

Carbamic  Acid — Amidoformic  Acid — H2N.CO.OH — is  not  known 
in  the  free  state,  being  decomposed  into  CO2  and  NH3,  but  ammonium 
carbamate  is  formed  whenever  ammonia  and  carbon  dioxid  are  in  con- 
tact: C02+2NH3=H2N.CO.O(NH4),  and  it  therefore  exists  in  com- 
mercial ammonium  carbonate,  and  is  formed  by  oxidation  of  many 
carbon -nitrogen  compounds,  notably  amido- acids,  in  alkaline  solu- 
tion. It  exists  normally  in  the  blood  and  urine,  and  is  formed  in  the 
system  as  an  intermediate  product  between  amido-acids  and  urea.  It 
is  obtained  by  directing  dry  ammonia  and  carbon  dioxid  into  cold 
absolute  alcohol,  as  a,  white,  crystalline  precipitate. 

The  esters  of  carbamic  acid,  called  urethans,  are  more  stable  than 
its  salts.  They  are  formed  by  the  action  of  ammonia  upon  the  car- 
bonic esters:  OC:  (OC2H5)2+NH8=?=H2N.CO.O(C2H5)+CH3.CH20H; 
and  by  the  action  of  cyanogen  chlorid  upon  alcohols:  CNCI+2CH3.- 
CH20H=H2N.CO.O(C2H5)  +  CH3.CH2Cl.  Ethyl  urethan,  produced 
by  the  above  reactions,  forms  thin,  large,  transparent  plates,  f.  p. 
50°,  b.  p.  184°,  very  soluble  in  water  and  in  alcohol.  It  is  used  as  a 
hypnotic,  either  alone  or  combined  with  chloral  in  uralium,  or  somnal. 
Phenyl  urethan,  H2N.CO.O(C6H5),  is  a  light,  white  powder,  almost 
insoluble  in  water,  very  soluble  in  alcohol,  which  is  used  as  an  anti- 
pjTetic  under  the  name  euphorine. 

Carbamyl  Chlorid— [7rm  OAZortV?— H2N.CO.CI— is  formed  by  the 
interaction  of  carbonyl  chlorid  and  ammonium  chlorid  at  400°: 
COCl2+NH4Cl=H2N.CO.Cl+2HCi.  It  is  a  crystalline  solid,  f.  p. 
50°,  b.  p.  61°,  at  which  latter  temperature  it  dissociates  to  cyanic 
and  hydrochloric  acids:  H2N.C0.C1=NC0H+HC1,  and  the  former 
polymerizes  to  cyammelid  (p.  396). 

One  or  both  of  the  H  atoms  of  carbamyl  chlorid  may  be  replaced 
by  alkyls  to  form  urea  chlorids,  which  are  produced  by  the  action  of 
carbonyl   chlorid  upon  the  monarain   hydroehlorids:    C1H3N.(C2H5) 

+COCl2=(C2H5)HN.CO.Cl+2HCl,orClH2N:(CH3)2+COCl2=(CH3)2 
N.C0.C1+2HC1. 

Carbamyl  chlorid  and  the  urea  chlorids  are  decomposed  by  water 
to  CO2  and  ammonium  chlorid  or  amin  hydroehlorids:  H2N.CO.CI+ 
H20  =  C02+NH4C1,  or  (CH3)HN.CO.Cr+H20=C02+ClH3N.CH3. 
They  form  urethans  with  alcohols :  H2N.C0.C1+CH3.CH20H=H2N.- 
CO.O(C2H5)+HCl.  With  amins  they  form  alkvl  ureas  (p.  406): 
H2N.CO.Cl+H2N.(C2H5)=H2N.CO.NH(C2Hr,)+HCl.  In  presenceof 
AI2CI6  they  form  aniids  with  benzene  and  with  phenol  ethers  (p.  446). 


AMIDS    OP    DICARBOXYUC    ACIDS 


403 


Oxamic  Acid— COOH.COXHa — and  itg  Biiperior  homologues  are 

lined  by  OMrefnIly  distiltintj  tLie  moiioamnioiiium  salt  of  tlie  acid: 
COOH,COO(XUi)=COOHXOXH2+H20,  a  method  of  formatiou 
corresponding  to  thoi^e  hy  which  the  monamids  and  diamids  are  pro- 
duced. Or  their  salts  are  formed  by  the  action  of  alkalies  upon  the 
imins.  Thus  suecinatnic  acid  is  formed  from  succinimid:  cH^!co/^H 
H-KHO  =  H2N.CO.CH2.CH2.COOK. 

Malonamic  Acid  is  unknown,  altliough  its  ethyl  ester:  CONII2.- 
rH2.COO{C2H5),  is  known.  Succinamic  Acid,  CONH2.CH2.CH2,- 
COOH,  is  obtained  as  described  above.  Its  aniido  derivatives  are  the 
HJ!i^paragins  (p.  419). 

Aeids  also  exist,  either  as  sueh  or  in  their  esters,  in  which  one  or 
both  of  the  H  atoms  in  NH2  of  carbamic,  oxaniie  acid,  etc.,  is  or  are 
replaced  bj  alkyls.  Such  are  ethyloxamicaoid,  COOIIX'ONH(C2H5)» 
and  diethyloxamic  ester,  COOlCaH^)  .CON(C2H5)2.  These  compounds 
correspond  to  the  anilie  acids  of  the  cyclic  series,  such  as  oxanilic 
acid  (p.  480):   COOH.CONHduHn). 

The  primary  diamids  only  are  acyclic  corapouufls  (see  diamine, 
p,  385).  They  are  formed:  (l)  by  the  action  of  ammonia  upon  the 
neutral  esters.  Thus  ethyl  oxalate  yields  oxamid:  C00(C2H.'i).C00- 
(C»Ib)+2NH:i=CONH2.CONH2+2CH:i.Cn20Hj  (2)  by  heating  the 
neutral  aniraonium  salt  of  the  corresponding  acid.  Thus  ammonium 
[carbonate  yields  carbamide  OCr  {ONH4)2=H2N.CO.NH2  +  2Il20. 

Carbamid — Urea^H2N.CO.Xn2 — exists  in  the  urine  of  mammalia, 
and,  in  smaller  quantity,  in  the  excrement  of  birds,  fishes  and  some 
reptiles;  also  in  the  mammalian  blood,  chyle,  lymph,  liver,  spleen, 
lun^,  brain,  vitreous  and  aqueous  humors,  saliva,  perspiration,  bile. 
Til  ilk,  amniotic  and  allantoTc  fluids,  and  in  serous  fluids* 

Urea  is  formed  by  the  methods  given  above;  also,  (1)  as  a 
product  of  decomposition  of  uric  acid,  usually  b}'  oxidation.  Thus 
nitric  acid  oxidizes  uric  acid  to  urea  and  alloxan:  2CfiH4N40a+ 
2H2O+O2  =  200X014 +2C4H2N2O4.  (2)  By  the  hydrolysis  of  ereatin. 
Thus  urea  and  sarcosin  are  formed  by  the  action  of  KHO  iii>on 
ereatin;  C4HBXaO2+H30  =  C0X2H4+C3H7XO2*  (3)  By  the  action 
of  carbon  yl  eh  lor  id  upon  dry  ammonia:  COCl2  +  2NH3=CON2H4  + 
2HCL  (4)  By  the  action  of  barium  hydroxid  upon  guanidin  (p.  388), 
or  upon  the  hexon  bases,  lystn  and  arginin,  products  of  decomposi- 
tion of  the  proteins  (p.  417).  (5)  By  atomic  transposition  of  its 
iMomere,  ammonium  isoeyanate,  hy  heat:  0:C:X.XH4=H2X.CO.XH2. 
(0)  By  the  action  of  ammonia  upon  phosgene  or  upon  urea  chlorids: 
COi1H-4XH3=H2X,CO.XH2H-2Xn4CU  or  H2X.(X>.CI+2XH:J=^2X.- 
^O.NH2+XH4CL  (7)  By  lieatiug  ammonium  carbamate  to  130**: 
KbX.CO.OXHi=H2XXT).NH2+El20.  (H)  By  the  action  of  ammonia 
upon  nrethan:  n2X\CO.O(C2H6)+XH«=-H2X.CO.XH2+CHa.CH20H, 


404  JCAXTAL    OF    rHEaCSTBT 

Urea  CTTStftllisea  in  loa^  rfaombie  needL^  or  prLsms.  It  is  color- 
l/tsuk  and  odorteM.  and  ha^  a  r^oolin^  ta;»&e.  aoraewiiat  resembling  that 
of  ^Icpeter.  It  U  nencral  in  reaiMdoa,  aliiioagh  basie  in  charaeter; 
iK>lable  in  one  part  of  water,  in  ftTe  parts  al  cold  alndiol,  and  in  one 
part  of  baling  aieohol,  apartngij  aoinble  in  amjlie  akobol  and  in 
acetie  ^ther.  and  still  leaa  isolnble  in  ether.   It  fuses  at  132°. 

When  heated  a  few  degrees  aboTe  its  fusing  point  urea  appears 
to  Vioil.  from  escape  of  XHj.  and  is  decomposed  at  aboat  140°  with 
formation  of  ammelid  fp.  337).  CsHtN^Oi;  biuret  (p.  407),  CJOs- 
y/H,  and  eyannric  aeid  (pp.  396.   337) *  C^HsNiO^  according  to 

the  e/juation:  8HjN.CO  ^^,=Hl^.c(^^^'(OH)/^'  + H,^^ 

COXHj^HOX-f  ^lerSfll/^+eXHa+HiO.    The  ammelid  formed  is 

farther  h jdrolysed  bj  eontinned  heating  to  CTannrie  acid  and  ammonia : 
i;jH4NV>»+HjO=CjHaX303-rXtti.  and  finally  at  this  temperature  a 
dry  Molid  residae  remains,  which,  dissolTed  in  water,  gives  the  biuret 
THB^'ioxi  with  CnSOt  and  KHO  (p.  407).  On  continuing  the  heat  to 
9\ffmi  la^/"  the  biaret  is  also  decomposed  with  evolution  of  ammonia, 
leaving  cyanuric  acid  as  the  sole  solid  residue:  3CiH5N302=2C3H3Nj- 
0;»  +  3Nlh.  Finally,  if  cyannrie  aeid  be  heated  with  alkalies  it  is 
itlowly,  bnt  completely,  hydrolysed  to  carbon  dioxid  and  ammonia: 
<;aH»XjjO:>+3H20=3cb2+3XH3.  Folin's  quantitative  method  for  urea 
(p.  714),  in  which  the  required  temperature  is  attained  by  boiling 
31^^*12,  6Aq,,  b.  p.  160^,  is  based  upon  these  decompositions. 

I)ilfitc  arincouK  solutions  of  urea  are  not  decomposed  by  boiling, 
but  if  tlic  HoliiMon  be  concentrated,  or.  if  the  boiling  be  prolonged, 
or  the  temperature  raiHcd  above  100°  by  pressure  or  otherwise,  urea 
iH  \mr\\y  or  completely  hydrolysed  to  CO2  and  NH3:  H2N.CO.NH2+ 
Il20  =  C02  +  2NHrj.  Many  hydrolysing  agents,  such  as  dilute  acids 
or  alkalies,  Kall202  and  BaCl2  at  a  boiling  temperature,  BaCOa  at 
ISC^,  and  certain  bacteria  and  enzymes  bring  about  the  same  deeom- 
poHition,  which  is  that  which  occurs  in  "fermenting"  urine. 

NitrouH  acid  decomposes  urea,  as  it  does  all  aliphatic  amins  and 
amidH,  with  evolution  of  the  nitrogen  from  both  acid  and  amid  as 
free  nitrogen:  n2N.CO.NH2  +  2HN02=C02+2N2+3H20.  A  similar 
decomposition,  but  yielding  half  as  much  nitrogen  per  mol  of  urea,  is 
effected  by  direct  or  indirect  oxidants,  such  as  alkaline  solutions  of 
hypochlorites  and  hypobromites,  chlorin,  etc.:  2H2N.CO.NH2+3O2 
=2(^02  + 2N2  +  4II2O. 

With  formic  aldehyde  urea  forms  a  product,  probably  of  condensa- 
tion, whose  constitution  is  still  undetermined,  which  separates  as  a 
white,  crystalline,  almost  insoluble  solid  when  excess  of  formalin  is 
added  to  solutions  of  urea  containing  a  little  HCl.  When  added  to  a 
concentrated   solution    of    furfurole  and   HCl,    solid    urea,    or   urea 


i 


THIOUKEA    AND    THIOCARBAMIC    ACIDS 


405 


Blbttto,  forms  a  yellow  soluliuii,  cliaugiug  iu  eolor  to  green,  blue  and 
tiiteBSe  purple* violet;  and  after  a  time  the  mixture  thickens  and 
blackens  (Schiff's  reaction).  Urea  and  amidoacetic  acid,  when  fused 
together,  combine,  in  part,  to  form  urie  acid:  8H2N.CO.NH2H-CH2- 
NH2.COOH=C5H4N403+2H20  +  3NH,3  (pp.  407,  529).  With  phenyl- 
hydrazin,  area  in  acetic  acid  solution  condenses  to  pheuylsemicar* 
bazid:  HjN.CO.KHs+HaN.NH.CflHs^H^N.CO.NH.NH.CfiH^+NHa, 
a  white,  sparingly  soluble,  crystalline  solid,  f.  p.  170°.  With  phos- 
photnngstic  acid,  urea  forms  a  compound  of  such  solubility  that  a 
precipitate  is  formed  if  the  proportion  of  urea  be  greater  than  2  per 
cent,  but  none  if  it  be  less  (p.  716).  Urea  is  not  precipitated  from 
aqueous  solutions  containing:  BaCb  and  BaH202  by  a  mixture  of 
alcohol  and  ether  1:2  (p.  715). 

Urea  forms  definite  compounds,  not  only  with  acids,  but  also 
with  certain  salts  and  oxids.  Urea  nitrate  —  H2N.CO.NH3.NO3  — 
forms,  in  whitt*  crystals,  when  a  concentrated  solution  of  urea  is 
treated  with  nitric  acid  in  the  cold.  It  is  much  less  soluble  than 
urea,  especially  in  presence  of  an  excess  of  nitric  acid.  It  is  decom- 
posed by  evaporation  of  its  solutions.  Urea  oxalate— <JOr{NHa ) 3:0*- 
Cj  —  separates  as  a  fine,  crystalline  powder,  from  mixed  concentrated 
aqueous  solutions  of  urea  and  oxalic  acid.  Its  solution  may  be  evap- 
orated without  decomposition. 

When  solutions  containing  molecular  weights  of  urea  and  so- 
dium chlorid  are  evaporated,  prismatic  crystals,  containing  CON2H4, 
NaCl  +  HsO  are  obtained.  Urea  fonns  several  compounds  with 
mercuri*^  oxid.  Of  thesf>,  the  compound  (CON2IIV):;,  4HgO,  con- 
taining 72  pai'ts  of  HgO  for  10  parts  of  urea,  is  formed  as  a  white, 
amorphous  precipitate  when  a  dilute  solution  of  mercuric  nitrate  is 
gradually  added  to  a  dilute,  alkaline  solution  of  urea,  and  the  excess 
of  acid  neutralized  from  time  to  time. 


THIOUREA    AND   THIOCARBAJHIC   ACIDS. 

The  thio- compounds,  corresponding  to  cm'bamic  acid  (p.  402) 
and  to  urea,  in  w^hich  oxygen  is  replaced  by  sulfur,  exist  either  in 
iLeir  own  forms  or  in  their  derivatives.     Thus: 


ThIo«ftrb«inic  acid.      Snlfocarbunlc  »eid.   DltMocftrbamlc  Kcid. 


0:C 


Tbloareft. 


Thiocarbamic  acid  and  sulfocarbamic  acid  are  known  only  in 
their  esters.  Dithiocarbamic  acid  may  be  obtained  by  decomposition 
of  it»  ammonium  salt,  which  is  produced  by  the  action  of  ammonia  in 

alcoholic  solution  upon  carbon  disulfid  :   CS2  +  2NH3  =  S ;  Cs.  nh,. 


406  MANUAL    OF    CHEMISTBt 

Similarly,  the  arain  salts  of  the  alkyl-dithiocarbainic  acids  are  formed 
by  the  action  of  the  primary  amins  upon  carbon  disolfid  (p.  380). 
Thiourea    is   obtained    by   heating    ammonium    isothiocyanate: 

8:C:N(NH4)=S:C\jjU^,  as  urea  is  obtained  from  the  isocyanate 
(p.  403).  It  is  also  formed  by  the  action  of  hydrogen  sulfid  upon 
cyanamid  (p.  398):  H2S+CN.NHj=S:C<(jJ||.    It  is  decomposed  by 

boiling  acids  or  alkalies  into  COs,  NH3,  and  HsS.  It  forms  salts,  and 
alkyl,  phenyl  and  acidyl  derivatives  similar  to  those  of  urea.  By  addi- 
tion with  alkyl  halids  thiourea  forms  salts  of  alkyl  thiopseudoureas, 
corresponding  to  pseudourea  (p.  389),  which  are  used  in  certain  cyclic 

syntheses  (p.  523):  H2N.CS.NH2+C2H5C1=HN:C<^^^^\. 

COMPOUND   UREAS. 

These  compounds,  which  are  exceedingly  numerous,  may  be  con- 
sidered as  derived  from  urea  by  the  substitution  of  one  or  more 
alcoholic  or  acid  radicals  for  hydrogen  atoms. 

Those  containing  alcoholic  radicals,  alkyl   ureas,  such  as'  ethyl 

urea,  C0<^^'(^h6»  *^  obtained:  (1)  By  the  action  of  primary  or 
secondary  amins  upon  isocyanic  esters:  NH2.C2H5+0:C:N.C2H5  = 
CO:(NH.C2H5)2.  (2)  By  heating  the  isocyanic  esters  with  water, 
the  amins  and  carbonic  acid  being  formed  as  intermediate  products: 
OC:N.C2H5+H20=NH2.C2H5+C02,  and  OC:N.C2H5+NH2.C2H5= 
€0:(NH.C2H5)2.  (3)  By  condensation  of  amins  with  urea  chlorid(p.402). 
Those  containing  acid  radicals  have  received  the  distinctive  name 
of  ureids.  Of  these,  some  are  monureids,  derived  from  a  single 
molecule  of  urea,  others  diureids,  derived  from  two  molecules.  Some 
of  the  monureids  are  open  chain  compounds,  but  the  most  important, 
of  them,  and  all  the  diureids  except  carbonyl  diurea  are  cyclic  com- 
pounds, derivatives  of  glyoxalin,  pyrimidin  or  cyanidin.    Thus  there 

CH2OH 
are  two  ureids,  corresponding  to  glycollic  acid,  I  :  one,  hydanto'ic 

COOH 

acid,  an  open  chain  ureid:   COn^j^jj^qu^qooH'    ^^®  other,  hydantom, 

.NH.CHo 
a  cyclic  compound:    C0\         I 

^NH.CO 

Only  the  acyclic  ureids  will  be  here  considered,  the  cyclic  ones 
will  be  referred  to  as  derivatives  of  their  parent  substances. 

The  monacidyl  monureids,  containing  a  single  acidyl,  are  formed 
by  the  action  of  acidyl  chlorids  or  anhj^drids  upon  iirea.  Thus 
acetyl-urea  is  obtained  with  acetyl  chlorid:  CH3.CO.CI+NH2.CO.- 
NH2  =  H2N.CO.NH  (CO.CH3)  +  HCi,  or  with  acetic  anhydrid  : 
(CO.CH3)2,0  +  2NH2.CO.NH2  =  2NH2.CO.NH(CO.CH3)  +  H2O. 


COMPOUND    UREAS 


407 


Mixed  urcids,  containing  an  alkyl  and  an  aeidyl,  are  t'ornifd  in  like 
mauuer  from  alkyl-ureas.  Thus  methyl-urea  and  acetyl  chlorid  form 
metbyi-acetyl-nrea:  CH3.NH.CO.NH2  +  CHa^COXl  ^Clia.NH.CO.- 
NHCCO.CHa)^-!!^^!-  Such  mixed  nreids  are  also  formed  by  the 
actioQ  of  bromin  and  potassinm  hydroxid  upon  the  araids,  by  reac- 
tions comparable  wiUi  those  wliicli  produce  the  monamins  (p,  379). 
Thus  metliyl-aeetyl-urea  is  formed  from  acetaraid:  2Cn:{.CO.NH2+ 
Bi^+2KHO=CH3.Hx\.CO.NH(CO.CH:i)+2KBr+2H.iO. 

The  diacidyl-ureids  are  formed  by  the  aetion  of  phosgene  (car- 
bnoyi  chlorid)  upon  the  amids.  Thus  acetamid  yields  diaeetvl-urea: 
2CHaX'O.NH.  +  COCl2-(CHa.CO)HN,CO.NH(CH:i,CO)+2HCL 

Allophanicacid—II:iN.CO,XILCOOH— the  simplest  of  the  acyclic 
iDonareids,  is  that  of  carbonic  acid,  HO. CO. OH,  and  is  known  only 
in   its  esters. 

Biuret— HsN.CO.NH. CO. NH2— is  both  the  amid  of  allophanic 
acid,  and  the  mouureid  of  carbarn ic  acid,  H2N.CO.OH.  It  is  formed 
by  heatiufj  the  allophanic  esters  with  ammonia;  H2N.CO.NH.COO- 
(C2H5)  +NH:i=H2N.CO.NH.CO-NH2+(^H3.CH,on  •  by  condensation 
of  area  and  carbaraic  acid:  H2N.CO.NH2+HO,CO.NH2^H2N.CO> 
NH . CO . N H2+ HjO ;  a u d  by  h eat i n f?  urea  to  abtni  1 1 50°  r  2H2N .  CO . NHa 
=H2NX'O.NH.CO.NH2-f  NH:i.  When  furt.lier  heated  it  is  itself  decom- 
posed to  eyamiric  acid  and  ammonia:  3C2Hr.N302=2C3H3N:iOii+3NH3- 
It  forms  crystals,  soluble  iu  water,  f,  p,  190^.  It  is  chiefly  of  interest  in 
connection  with  the  biuret  reaction,  which  consists  in  the  formation 
of  a  red -violet  liquid  when  biuret  is  heated  with  a  dilute  solution  of 
CnSO*  alkalized  with  KHO  {see  Fehlin^j's  test}.  The  reaction  is  due 
to  the  formation  of  a  compound,  Cu[NH2(OH).CO.NH.CO.NH2- 
(OH)K]2,  which  has  been  obtained  iu  red  crystals.  Or  NiSOi  may 
be  used  iu  place  of  CuSOi,  iu  which  case  an  orange -colored  liquid  is 
produced.  The  biuret  reaction  is  given  by  many  substances  other 
than  biuret,  such  as  malouamid,  oxamid,  aspartic  diamid,  albumins, 
aibumoses,  peptones,  etc.,  and  is  considered  to  be  proof  of  the  presence 
in  the  substance  giving  it  of  two  amido-carbonyl  groups,  CONH2, 
attached  to  each  other,  or  to  N  or  C;  as  in: 


CONHs 

I 
CONH, 

Oxftmld. 


HN 


^CONHa 

"^CONHa 

Biuret . 


/CONH, 
HaC<; 

^CONHj 

Malonamld. 


The  reaction  is  also  given  by  glycoeol  amid  and  sarcosin  amid^ 
which  contain  the  grouping:   HaN.CHa.CCNHa  (p.  678). 

Hydantoic  Acid— -Ghfco lit rie  A ri rf— H2N . CO . N H A^ H2, COO H— the 
next  superior  bomologue  of  allophanic  acid,  is  the  acyclic  mouureid 
of  glycollic  acid,  CH20H.C00PI.  and  is  obtained  as  its  Ba  snlt  by 
hydration  of  the  corresponding  eyelie  monureid,  hydantoin,  by  BaH2- 
Oj  (p,  515).    It  is  alao  formed  by  condensation  of  urea  and  amido- 


408 


MANUAL    OF    CHEmSTEY 


acetic  acid  at  120^H2^^CO.NH:i+Cf^2NH2.eOOH--H2N.CO,NH.- 
CHi,COOH  +  NHa.    {See  also  p.  405 J 

Oxaluric  Acid— H2N.CO.NH.CO.COOH— is  the  acyclic  monureid 

of  oxalic  aeid,  and  is  obtained  in  its  salts  by  hydration  of  those  of 

the  cyclic  monoreid,  oxalylurea  (p.  515).  The  free  acid  is  a  white, 
crystallioe  powder,  sparingly  soluble  in  water.  It  is  easily  further 
hydrolysed  to  urea  and  oxalic  acid  by  heating  with  alkalies,  or  even 
with  water.    Its  ammoDinni  salt  exists  in  the  urine  in  small  amount. 

Carbonyl  Diurea— H2N.CO.NH.CO  JIN.CO.NH2— the  only  acyclic 
diureid,  is  formed  by  the  union  of  two  nrea  molecules,  with  loss  of 
H2,  by  the  carbonyl  group,  l>rougbt  about  by  the  action  of  carbouyl 
chlorid  upon  urea:  2H2N.CO.NH2  +  COCl2=CO(HN.CO.NH2)2+ 
2HC1,  It  is  a  spariutjiy  soluble,  crystalline  powder,  whiclj  is  split  by 
beat  into  cyauuric  acid  aud  amiuoiiia:   C;jHBN403=CyH;jNa03+ NHa* 

Imids  are  compounds  derivable  either  by  substitution  of  an  acidy- 
len  for  H2  in  a  sin^ic  NH:t  moleinile,  or  by  substitution  of  the  iuiid 
group,  NH,  for  (OH)2  in  the  carboxylsof  a  dicarboxylic  acid  (p.  401). 
They  are  obtained  l»y  the  complete  dehydration  of  the  ainmuniura 
salts  of  the  neids,  or  siniihirly  from  the  amic  acids  (see  pp.  400,  402). 
Thus  mouoammonic  siiirciuate,  or  succioamic  acid  yields  suceiiiiujid: 


CH2.COOH 

I 


CH^^.CO 


\. 


CH2.COOH      CH2.CO. 


\ 


NH+UvO. 


The  imids,  therefore,  except  carbimid,  correspouJiug  to  carbonic 
acid»  which  is  isocyauic  acid,  0:C:N.H  (p.  396) »  are  heterocyclic 
compounds.  The  imids,  when  acted  upon  by  alkalies  or  baryta  water^ 
produce  the  salts  of  the  amic  acids.  Thus  succiuimid  and  caustic 
potash  form  potassium  succiuamate. 


I 


NITROGEN   DERIVATIVES  OP  ALCOHOLS,    ALDEHYDES  AND   KETONES. 

Nitro  derivatives  of  the  alcohols,  aldehydes,  and  ketones  in  which 
the  NO2  is  substituted  for  OH  or  for  O,  such  as  CHi.CHaCNOi)  aud 
CH3.CH(N02)2  aud  CH-[.C{N02)2^CH:f  are  mono-  or  dinitro-paniffius 
(p.  376).  Besides  these,  nItro  alcohols  are  alj^o  knosvn,  iu  wiiieh 
the  NO2  is  substituted  in  a  hydrocarbon  group»  e.  g.,  nitro  ethyl 
alcoholf  OH2(N€>2).CH20H,  wliich  may  also  be  considered  as  nitro- 
hydrin,  corresponding  to  the  chlorbydrin,  CflsCKCIUOH. 

Amido-alcohols,  such  as  amido  ethyl  alcohol,  or  oxethylamin, 
CH2{NH2),CH20H,  may  also  he  considered  as  derived  from  the 
ji:lycols  by  substitution  of  NHj  for  OH.  These  are  the  oxyamins,  hy- 
droxumhis,  kifdrfimins,  or  oxijnmin  bases^  among  which  are  choHu  and 
neurin  (p.  :]82).  By  further  substitution  of  NH2  for  OH  they  be- 
come diamins  (p.  385)* 


NITROGEN    DERIVATIVES    OF    ALCOHOLS,    ETC 


409 


Aldehyde  -  ammonia— ^^/r/t?f«e  hydrojcamia—CRs.CEC^^^ — iso- 
meric with  ethylene  liydroxamiii,  (;H2{NH2).CH20H,  may  be  i'oii- 
sidered  as  an  ainido  ethyl  alcohol  iu  which  the  XU2  ia  tiubstituted  for 
H  in  the  methoxyl  group,  CH3.CH(NH2)OH.  It  is  obtaiued  by  the 
action  of  dry  NHu  upon  an  ethereal  solution  of  aeetie  aldehyde; 
CPI:,.eHO  +  NH3=CHa.CH(NH2)OIL  It  is  a  erystalHne  solid,  spar- 
ingly soluble  in  wat«r,  alkaline,  f.  p.  SO"^. 

The  corresponding  eoniponnd  derivable  from  formic  aldehyde: 
H.CH(NH2)0H,  is  not  known;  i)nt  when  formaldehyde  aud  ammonia 
react  hcxamethylene  tetramin,  (rH-JttN4t  is  produced:  GH.CHO  + 
4XHM={t'H2)tfX4  +  6H20,  Tins  is  a  crystalline  solid,  %'ery  solnble  iu 
water,  which  dec^omposes  when  heated,  and  behaves  as  a  mooacid 
ba$^.  It  is  decomposed  by  weak  acids  and  by  acid  saltg,  in  the 
reverse  manner  to  its  formation,  with  liberation  of  formic  aldehyde, 
a  reaction  which  is  probably  caused  by  the  acid  sodium  phosphate  of 
the  urine,  and  explaijis  its  action  as  a  urinary  antiseptic,  for  which 
purpose  it  is  used  under  the  names /^rmm  and  nrotrophK 

Amido  aldehydes,  such  as  amido  acetaldehyde^  CHaCNHaJ.CHO, 
are  also  known. 

Acetonamins* — The  action  of  ammonia  U|>on  acetone  eanses  a 
condensation  of  two  or  three  molecules  of  acetone  with  one  of  ammo- 

per     rT'O  PH\ 

nia,  with  formation  of  diacetonamin :  '  ^'(oh  )  ^^^^NHa,  a  colorless 
liquid;   and  triacetonamin  :  OC'.qu^\qJ(^jj\/NH,  a  crystalline  solid, 

f.  p.  40°,  Alkyl  derivatives  of  these  are  formed  when  amins  are  used 
in  place  of  ammonia,  Amido  acetones,  or  amido  ketones,  such  as 
CH.itA'O.CH2(NH2)t  amido  acetone^  are  also  known. 

Aldoxims,  and  ketoxims  or  acetoxims  are  isomeric  eompouuds 
derivable  from  the  aldehydes  and  ketones  by  substitution  of  the 
oxim  group,  ^N.OH,  for  oxyg-eu.  As  the  aldehydes  and  ketones  are 
derivatives  of  formic  aldehyde  by  substitution  of  alkyls  for  H,  so  th« 
aldoxims  and  ketoxims  are  referalde  to  carboxim,  the  oxim  of  formic 
aldehyde: 


0€ 


/H 


Fnriaaldphjdf. 

\H 
CftrtM^xiiTK 


HON:C^ 


Dlm«tby1  ketone. 


HON:CC 


/CH3 


Ketoxlm 


AMaxim. 

They  are  formed  by  the  action  of  hydroxylarain  upon  aldehydes  or 
ketones  in  alkaline  solution,  the  aldoxims  more  readily  than  the 
ketoxims.  Thus  acetaldoxim  is  obtained  from  acetic  aldehyde:  CU3,- 
CHO+HONH2  =  CH,.CH:NOIl  +  H20,  and  acctoxim  from  dimethyl 
ketone:   CH r. CO. CHri+HONHa^CHf. r(NOH)  CH.+HiO. 

The   aldoxims   are   colorless   liquids,   miscible    with   water;     the 


410 


MANUAL    OF    CHEMISTRY 


ketuxims  crystalline  solids,  soluble  in  water.  Carboxim,  or  formoxim, 
ll.CH:NOH»  b.  p.  84 '^^  polymtjrizesj  spontaneously  to  trif ormoxim ; 
and  is  detjomposed  by  boiling  water  to  hydroeyauie  acid  and  water. 

Na:seeut  hydrogen  reduees  both  aldoxinis  and  ketoxims  to  amins, 
those  from  the  akloxims  being  amins  of  primary  alcohols  and  those 
from  the  ketoxims,  amins  of  secondary  alcohols:  CHa.CH:NOH+2H2 
=CH3.CH2NH+H20,  and  CH3.C{NOH).CH3+2H2=CH^.CHNH2.- 
CH3+H2O.  These  reactions  constitute  a  general  method  for  obtaining 
amins  (pp.  379,  382),  Both  aldoxims  and  ketoxims  are  hydrolysed  to 
their  parent  substances  by  boiling  with  acids:  CH^.CHrNOH+H^O 
=CH3.CHO+HOKH2»  and  CH3.C(NOH).CHy+H20  =  CH:i.eO.CH3 
+HONH2. 

The  principal  difference  between  aliphatic  aldoxims  and  ketoxims 
is  in  their  behavior  towards  acidyl  halids  and  anhydrids,  with  which 
the  former  produce  nitrils,  and  the  latter  esters.  Thus  with  acetal- 
doxim:  CH3.CH:NOH+CH3.COCl=CH3.CN+CHi.COOH  +  HCl,  or 
€H3.CH:NOH+(CH3.CO)20=CH3.CN+2CH3.COOH;  and  with  ace- 
toxim:  (CH3)2C:NOH+CH3.COCl  =  CH,.COO[N:C:(CH3}2]  +  HCl, 
or  (CH,)2C  :  NOH  +{CHri.OO).>0  =  CHn.COO  [X:C:  (CEa)^]  +  CH3.- 
€00 H.  Acetyl  ehlorid  and  anhydrid  cause  atomic  I'earrangeraent 
with  acyclic  and  some  higher  aliphatic  ketoxims,  to  form   phenyl  or 

alkyl  amids:  ^(;^;)C:NOH=ch^;^o/NH. 

Aldehyde  hydrazones  and  ketone  hydrazones  are  compounds  cor- 
responding to  tlie  aldoxims  and  ketoxims,  formed  by  condensation  of 
the  aldehydes  and  ketones  w^ith  phenyl  hydrnzin  (p.  484),  the  biva- 
lent remainder  of  which »  ^N.NH.CeHsT  i^  substituted  for  oxygen. 
They  are  obtained  by  the  action  of  piieuylhydrnzin  upon  the  aldehyde 
or  ketone  in  ethereal  solutions ;  OHa.i  ■HO+HsN.XH.CeHs-CHa.CH:  - 
(N,NH.CoH§)  +  HnO,  or  (CH3)2:CO+H2N.NHX'aHr>=(CH3);t:C:  (X.- 
NH.CflH5)  +  H.O. 

NITROGEN    DERIVATIVES   OP   ACIDS* 


The  nitrogen  derivatives  of  the  pure  carboxylic  acids  are  numer- 
ous and  varied.  They  may  be  divided  into  two  classes:  (1)  Those  in 
which  nitrogen  or  a  nitrogen -containing  group  is  substituted  in  the 
carboxyl  for  OOH  or  for  OH,  and  (2)  those  in  which  the  substitution 
is  in  a  hydrocarbon  group.  The  first  class  includes  the  uitrils,  ami- 
dins,  hydroxamie  acids,  amidoxims,  nitrolie  acids  and  amids,  which 
have  already  been  considered,  and  the  hydrazids,  which  are  com- 
pounds hearing  the  same  relation  to  the  hydrazins  (p.  390)  that  the 
amids  do  to  the  amins. 

The  following  are  included  in  the  second  class: 

Nitro-acids,  such  as  nitro-acetic  acid,  CH2(N02).COOH,  are  ue- 


NITROGEN    DERIVATIVES    OF    ACIDS 


411 


stable  compounds,  usaally  existing  only  in  tlieir  esters  and  salts.  As 
E  salt^  they  are  obtained  by  the  action  of  potassium  nitrite  upon  the 
saltsof  the  monochlor- fatty  acids:  CH2Cl.COOK+KN02=CH2(N02)  .- 
OOOK-fKCl.  They  are  readily  hydrolysed  to  nitroparaffins  and  a 
carbonate :  CH2(N02)  .COOK+H20=CH3.N02+KHC03. 

Monamido-acids  are  much  more  stable,  and  include  a  number  of 
aabstanees  of  physiological  interest.  They  are  derived  from  the  fatty 
acids  by  substitution  of  one  NH2  for  a  hydrogen  atom  in  a  hydrocar- 
bon group.  In  this  position  the  attachment  of  the  amido  group  is 
much  firmer  than  it  is  in  the  primary  monamids,  in  which  it  replaces 
the  hydroxyl.  The  amids  are  easily  converted  into  ammonium  salts 
by  boiling  water:  H2N.CO.CH8+H20=CH3.COO(NH4);  while  the 
amido  acids  are  not  acted  upon. 

Prom  the  pure  carboxylic  acids  (p.  327),  amic  acids  (p.  401), 
or  amids  (p.  399)  amido-acids  are  derivable  by  substitution  of  NH2 
for  OH  or  for  H: 


CH3 

I 
COOH 

Acetic  acid. 


CH3 

C0(NH2) 
AeeUmid. 


CHsCNHa) 

I 

coon 

Amido-acetic  acid. 


COOH 

I 

CHj 

I 

COOH 
lialonic  add. 


COCNHj) 

CHa 

COOCCjHs) 
Malonamie  ester. 


COCNHa) 

CHa 

I 

COCNHa) 
Malonamid. 


COOH 

CHCNHa) 
I 

COOH 
Amido-malonie  add. 


Prom  the  monocarboxylic  oxyacids  (p.  339),  oxyamids  are  de- 
Tived  by  substitution  of  NH2  for  OH  in  COOH;  amido -acids  of  the 
same  series  by  its  substitution  for  H  in  a  hydrocarbon  group ;  and 
.jimido- acids  of  the  acetic  series  by  its  substitution  for  OH  in  a  CHOH 
or  a  CH2OH  group: 


CHa 

CHOH 

COOH 

a  ozypropionie 

(lactic)  acid. 

CHa(NHa) 

CHOH 

COOH 

Amido-laetic 
acid. 


CH2OH 

I 
CHa 

COOH 

fi  oxy propionic 
(hydracrylic)  acid. 

CHj 

♦CH(NHa) 

COOH 

a  amldo-propionic 
acid. 


CHa 

I 
CHOH 

I 
CO(NHa) 

Lactamid 
ioxyamid), 

CHaCNHa) 

I 
CHa 

I 
COOH 

/3  amido-propionle 
arid. 


The  first  amido  -  acid  of  the  fatty  series,    amido-formic  acid, 
NHa.CO.OH,  is  carbamic  acid   (p.  402).     The  third  and  superior 


412 


MANUAL    OF    CHEMISTRY 


terms  of  the  series  form  place  isomeres,  according  to  the  position  of 
the  NH2  group,  eorrespoiidiiiK  t^^  the  oxynetds  and  sitoilarly  desig- 
nated (p.  340)  as  a^  A  y«  titc,  or  l-»  2%  3*»  etc.  Those  acids  in  which 
the  NH2  is  not  attached  to  the  terminal  C  atom  contain  an  as\Tnmetric 
C*,  and  therefore  exist  iu  optical  isomeres.  The  fatty  amido- 
acids  are  also  known  as  glycocolls  or  alanins.  They  are  obtained  : 
(1)  By  the  action  of  ainmouia  npon  the  mooochloro  acids.  Thus 
amido- acetic  acid  is  obtained  from  raouochloracetic  acid  :  CHjCl.- 
COOH+NH3=CH2(NH2)XOOH+HCL  (2)  By  reduction  of  the 
nitro- acids.  Thus  nitroacetic  ester,  CHaiNOal.COO.CsHs,  yields 
aniido*acetie  ester.  (3)  By  the  action  of  nascent  hydrogen  upon  the 
cyan-fatty  acids:  CN,COOH+2Hn=CH2(NH2),COOH, 

The  araido -acids  are  crystalline  solids,  most  of  which  are  sweet  in 
taste,  soluble  in  water,  insoluble  in  alcohol  or  in  ether,  neutral  ia 
reaction.  As  they  contain  both  amido  and  earboxyl  groups,  they 
have  both  basic  and  acid  functions.  With  acids  they  form  ammonium 
salts.  They  form  stable  metallic  salts  with  bases,  but  their  esters 
are  unstable.  The  esters  retain  their  basic  function  and  form  more 
stable  hydrochlorids.  Stable  compounds  are,  however,  produced  by 
the  replacement  of  their  amido  hydrogen,  either  by  acidyis  or  by 
alky  Is.  The  acidyl  compounds,  such  as  acetyl  amido-acetic  acid. 
CHj.NH(C2HaO).CO0H,  are  formed  by  the  action  of  acidyl  chlorids 
upon  the  amido-acida;  and  the  alkyl  derivatives,  such  as  methyl  gly- 
cocoll,  CH2.NH(CH3).COOH.  by  the  action  of  amius  upon  haloid 
fatty  acids.  On  dehydration  the  amido- acids  behave  like  Ihe  oxy- 
acids  (pp.  340,  368),  which  are  also  both  basic  and  acid.  The  a  acids 
on  dehydration  yield  cyclic  anhydrids,  which  are  ketopiperazinSr , 
(p.  522)  and  which  on  hydration  yield,  not  two  molecules  of  the  acid, 
but  a  dipeptid  (p.  416),  The  y  and  ^  acids  yield  cyclic  esters,  called 
lactams,  corresponding  to  the  lactones.  The  resemblance  of  these- 
compounds  is  shown  by  the  following  formula?: 


I 
COOH 

Amido- ftceUo 
acid. 


CHj.NH.CO 

I  ! 

CO.  NH.CHa 

GlycocoU 
BUihydrid. 


CHa,OH 

COOH 

OlyroUk 
Acid, 


CH2.COO 

I  I 

COO  —  CHi 

Gljeollld 


CH2NH1 
I 
CHa 


I 

COOH 

y  mmido'bntjric 

^id. 


CH2NH 

i 

CHa 

I        ^ 
CH3 

I 
CO  . 

y  btitjTo* 


CHj.OH 

CH2 

I 
CHa 

COOH 

7  ojcybutyric 
acid. 


CHj  '^ 
I 
CHs 

I 
CHa 

I 
COO 

7  butyro- 
lacfunt. 


The  formation  of   the  lactams  is  another  instance  of   the  pro- 
duction  of    closed   chain    from    open    chain    compounds    (pp.    368, 


NITROGEN    DEBIVATFinES    OF    ACIDS 


413 


387).     Delta  valcrolactam  is  the  cyclic  a  keto-piperidin,  or  a-oxy- 
piperidiu  (p.  519) : 

CHiNH  Hi 

G 
/  \ 


CHj 

I 
CHa 

t 

9  yaleroliktftam. 


N 
H 


I 

/    \ 

I  I 

HiC    a    CO 

\   / 

N 

H 


By  dry  distillation  the  amido  acids  are  split  to  atiuos  and  carbon 
dioxid:  CH2Ne2.COOH=CH:i.XH2+C02.  When  heated  with  hydri- 
odic  acid  at  200°  they  are  reduced  to  fatty  acids:  CHiXH2.CO0H+ 
H2^=CHruCOOH+NH3.  Amido  acids  of  the  acetic  and  oxalic  series  are 
converted  into  the  corresponding  monochlor  acid  by  nitrosyl  chlorid: 
CH2NH2.COOH  +  NOCl=CH,CLCOOH+N2+H20,  Nitrons  acid  acts 
upon  the  a*amido  acids  aecitrdiiis?  to  the  reaction  characteristic  of  the 
amido  gronp  (p.  380),  convettititc  them  into  oxyacids,  with  evolution 
of  fi-ee  nitrogen;  CH2NHj.C00H  +  HN02=CH2OH.CU0H  +  N2  + 
H2O.  This  conversion  Af  amido  into  oxyacids,  which  probably  occurs 
in  the  animal  orgmiism,  is  referred  to  as  deamidation, 

Annido-acetic  Acid— Glycocoll —  Gh/ein — Ghjrnktmie  acid — Gelatin 
gugar — CH2.NH2.<-**>OH^ — was  first  obtained  by  tlie  action  of  HiSO^ 
npon  gelatin.  It  is  formed  by  the  action  of  KHO  upon  glne;  and, 
nynthetically.  by  the  methods  given  above  and  by  the  union  of  formic 
aldehyde,  hydrocyanic  aeid  and  water:  H.€HO  +  HCN+H20=CH2- 
(jrH2)*C00H,  It  is  produced*  along  with  benzoic  acid,  in  the  decom- 
position of  hippuric  acid  (p*  479);  as  a  product  of  decomposition  of 
glycocholie  acid;  and  by  the  action  of  hydriodic  acid  npon  nric  aeid 
(p.  530).    It  occurs  uncombiued  in  the  muscle  of  the  scallop. 

It  appears  as  large,  colorless^  transparent  crystals;  has  a  sweet 
taste;  fuses  at  170°  (338^  P,);  sparingly  soluble  in  cold  water; 
much  more  soluble  in  warm  water;  insoluble  in  absolute  alcohol 
and  in  ether. 

It  forms  crystalline  salts  with  acids,  which  are  decomposed  at  a 
boiling  tempeniture.  Nitric  acid  oxidizes  it  to  glyeollic  acid.  It  is  very 
resistant  to  oxidation  by  K2Mn20«  in  acid  solution,  but  in  alkaline  solu- 
tion or  in  its  esters  it  is  readily  oxidized  to  urea:  2CH2NH2,COOH+ 
303=H2N.CO.NH2'f  3CO2+3H2O.  from  which  it  is  presumed  that  the 
free  acid  does  not  exist  as  such,  but  as  a  lactam.  Its  aeid  function  is 
more  marked;  it  expels  carbonic  and  acetic  acids  from  calcium  car- 
l>onate  and  lead  acetute.  It  dissolves  eupric  hydroxid  in  alkaline  solu* 
tioOt  and  there  is  no  reduction  on  boiling  the  solution;   but  on  addi* 


414 


MANUAL    OP    CHEMISTRY 


tioii  of  alcohol  to  the  cold  solution,  blue  crystalline  needles  of  copper 
glyeolamate  separate.  With  ferric  elilorid  it  gives  an  intense  red 
color,  which  is  discharged  by  aeids,  and  restored  by  ammonia.  With 
phenol  and  sodium  hypochlorite  it  gives  a  blue  color*  as  does  ammo- 
nia. It  forms  esters  aud  amids.  Its  methylic  ester  is  isomeric  with 
sarcosin.  Heated  under  pressure  with  benzoic  acid  it  forms  hippnrie 
acid.  Fused  with  urea  it  forms  glycolylurca  (p.  515)  and,  ultimately, 
uric  acid.  Glyeocoll  may  be  separated  from  other  amido  acids  by 
crystallization  of  the  hydrochlorid  of  its  ethyl  ester. 

Methyl-glycocoU—  Sarcosin^-^CHi.XJKOHal.rOOH  —  isomeric 
with  alanin,  the  methyl  ester  of  glyeocoll,  and  hictaraid,  is  not  known 
to  exist  as  such  in  animal  nature,  but  it  may  be  obtained  from  crea- 
tin  {p.  389)  by  the  action  of  barium  hydroxid: 


^^'^\NiCH,).CH,.CO0H   "^  ^^^ 


=    CHa.NH(CH3).COOH  +  HjN.CO.NH,. 


It  is  formed  by  the  action  of  methylamin  upon  nionochloracetic  acid: 
CH2CLCOOH+CRvH2N--CH2.NH(0Ha).COOH+HCl. 

It  crystallizes  in  colorless,  transparent  prisms  ;  very  soluble  in 
water;  sparingly  soluble  in  alcohol  and  ether*  Its  aqueous  solution 
is  not  acid,  and  has  a  sweetish  taste.  It  foriufe  salts  with  acids,  but  it 
is  not  known  to  form  metallic  salts.  It  unites  withcyanamid  to  form 
creatin  (p.  389)  ;  and  with  cyanogen  chlorid  to  form  methyl- 
hydantom  (p.   515). 

Amido-proptonic  Acids — ^Alanins — Two  are  known  *  «  alanin» 
CH<j.CH(NH2).C00H,  formed  by  the  reduction  of  ^  nitroso- propionic 
acid;  and  P  alanin,  CHsiNHa). €112.00011,  formed  either  by  the 
reduction  of  ^  nitroso -propionic  acid,  or  by  the  action  of  ammonia 
upon  P  iodo- propionic  acid.  Neither  is  known  to  exist  in  nature. 
Nitrous  acid  converts  the  two  alanins  into  the  corresponding  lactic  acids. 

Amido-butyric  Acids-™C4H«N02 — and  Amido-valerianic  acids — 
C^HiiNOo — are  mainly  of  tlicoretic  interest.  Alpha  aniido-n-valen- 
anic  acid,  CIIa.CH2.CH2.CH(NH2).C00H,  is  a  product  of  oxidation 
of  coniin.  Delta  amido-n-valerianic  acid— Butalanin,  CH^CNHj),- 
(CH2)3.C00H,  occurs  in  the  pancreas,  and  is  formed  as  a  product  of 
decomposition  of  flhrin  and  of  certain  proteids. 

Amido-caproic  Acids — Leucins, — Twenty -nine  isomeric  amida 
acids  are  derivable  from  the  seven  eaproic  acids;  and  this  number  is 
still  further  increased  by  the  fact  that  in  many  of  these  the  introduc- 
tion of  the  amido  group  renders  a  carbon  atom  asymmetric  (see  far- 
itiola  of  o.  amido -propionic  acid,  p.  411).  The  leucin,  which  is  of 
physiological  interest  as  a  product  of  decomposition  of  the  proteins,  is 
the  inactive  a  amido-isobutyl-acetic  acid,  (CH3)2:CH.CH2.*CH- 
(NH2).C00H,  as  is  demonstrated  by  its  synthetic  formation  from 


NITROGEN    DERIVATIVES    OF    ACIDS 


415 


isovaleric  aldehyde,  (CH3)2:CH,CH2.CHO.  The  corresponding  dextro- 
aeid  has  been  obtained  by  the  action  of  Penieiliium  glaucum  upon  the 

I  inactive   acid;    and   the   laevo*   acid,    known  as  "vegetable  lenein" 

^from  the  vegetable  globulin,  eonglntin. 

"Aoimal  leucin'^  is  produced,  accoinpanied  by  tyrosin  (p.  478), 

•in  the  decomposition  of  proteins  by  boiling  with  dihite  acids  or  alka- 

'lies,  by  fusion  with  caustic  alkalies,  by  putrefaction,  and  by  trypsin 
digestion.  It  appears  to  exist  also  as  a  normal  constituent  of  the 
pancreas,  spleen,  thymus,  lymphatic  and  salivary  glands,  liver   and 

I  kidneys.  Pathologically  the  quantity  of  lenciu  is  much  increased  in 
the  liver  in  diseases  of  that  organ,  in  typhus  and  iu  variola;  iu  the 
bile  in  typhus;  in  the  blood  in  leuka3mia,  and  in  yellow  atrophy  of 
the  liver;  in  the  urine  in  yellow  atrophy  of  the  liver,  in  typhus,  in 
variola,  and  in  phosphorus  poisoning;  in  choleraic  discharges  from 
the  intestine;  in  pus;  in  the  fluids  of  dropsy  and  of  atheronintous 
cysts.    (See  p.  756.) 

Leuein  crystallizes  from  alcohol  in  soft,  pearly  plates,  lighter  than 
water,  and  somewhat  resembling  cholesterol ;  sometimes  in  rounded 
masses  of  closely  gronped,  radiating  needles.  Pure  leuein  is  spar- 
ingly soluble  in  water,  almost  insoluble  in  alcohol  and  ether,  but 
readily  soluble  iu  hot  water  or  alcohol.  When  impure  it  is  more 
soluble.  It  is  odorless  and  tasteless,  and  its  solutions  are  neutral. 
It  dissolves  readily  in  acids  and  alkalies,  forming  crystalline  com- 
pounds with  the  former.  It  fuses  and  sublimes  at  170°  (338*^  F.) 
without  decomposition,  but  at  a  slightly  higher  temperature  is  decom- 
posed into  amylamin  and  carbon  dioxid. 

When  heated  with  hydriodic  acid  utider  pressure  the  leucins  are 
decomposed  into  atnmonia  and  tlie  **orresponding  caproic  acids.  By 
nitrous  acid  they  are  oxidized  to  the  corresponding  oxycaproic,  or 
leucic  acids«  CeHtL^Oa  (p.  342),  with  elimination  of  water  and  of 
nitrogen.  Hot  solutions  of  leuein  form  precipitates  with  hot  solu* 
tions  of  cupric  acetiite*  They  dissolve  cupric  hydroxid,  but  do  not 
reduce  it  on  boiling.  When  boiled  with  solution  of  neutral  lead  ace- 
tate and  carefully  neutralized  with  ammonia,  they  deposit  brilliant 
crj^tals  of  a  compound  of  leuein  and  lead  oxid.  When  HNO3  is 
slowly  evaporated  in  contact  with  leuein  on  platinum  foil  a  colorless 
residue  remains,  which,  wiien  warmed  with  NaHO  solution,  turns 
yellow  or  brown,  and  on  further  concentration,  forms  oily  drops, 
which  do  not  adhere  to  the  platinum  {Scherer's  reaction).  Solution 
of  leuein,  when  heated  with  solution  of  mercurous  nitrate,  liberates 
metallic  mercury  (Hofmeister's  reaction). 

Polypeptids— are  products  of  tryptic  digestion  of  proteins,  inter- 
niediate  between  the  peptones  and  amido- acids.  They  have  been 
obtained  synthetically  by  methods  which  show  them  to  be  constitnt-ed 


416 


MANUAl.    OF    CHEMISTBY 


1 


by  siibstitiitioii  of  aTiiido-ackl  radieals  for  H  in  NH2  of  the  a-amido- 
nv'ids.  Tlir-y  are  dipeptids,  containing  one  such  radical,  or  tri-,  tetra-, 
pentapeptids,  eootaiuino:  two,  three  and  fonr,  1 

Glycylglycin — is  tht^  siiuplest  of  these  eonipounds.  It  is  obtained 
synthetically  by  hydrolysis  of  glycoeoll  anhydrid,  or  diaeipiperazin 

HN.CH3.CO 
(pp.  412,  522) :       I  I     +  H2O  =  H.N.CH2,CO,NH.CH2.COOH., 

Similarly    other    dipeptids    containing    like    radicals:    alanylalani 
leucylleucin,  are  obtained  from  other  diacipiperazins. 

Another  method  of  synthesis  permits  of  the  formation  of  ''mixed** 
polypeptids,  as  well  as  of  those  containing  like  radicals:  By  the, 
action  of   chloraeetyl   chlorid    upon   a-aknin,   chloi'acetyl-ahuiiu   ii 

formed:  hSX^^^^'*^^^  +  *^'*^'^^-^^^^**^^'^=cich,xo.h^^ 

HCl.     This  is  amidated  by  ammonia  to  glycylalanin:  qk^u..  cq  jIs 

of  synthesis  also  permits  of  the  fornnitjon  of  tri-,  tetra-,  and  penta 
peptids  by  repetition  of  the  processes.  Thus  glyeoeoll  and  chloraeetyl 
ehlorid  yield  chloraeetyl  glycin:  Hi>N.c;H2.tX>On+(1CH2.CO.Cl= 
CiCH2.0O.HN.0H2XH)0H  +  HCl;  and  this  is  amidated  by  ammonia_ 
to  glycylglycin  :  ClCHs.OO  HN.t  H2.1X)OH+2NH3=n2N.CH2.CO.« 
HN.CHa.COOH+KH^Cl.  Olyeylglyein  with  chloraeetyl  chlorid  yields 
chloraeetyl -glycylglycin:  H2N.t'H.jAX>.HX  J^H2.COOII  +  ClCH2^CO.- 
^l=^ClCH2.c6.HNX^HL*.CO,H^^CII::XX)OH+H^l;  which  is  ill  turn 
amidated  by  ammonia  to  diglycylglycin :  C1CH2X'(>.HN.CH2X^0,- 
HN.rH2  (OOH  +  2NH3=H>N  CHs.OCJHNXHj.CO.HXX"^  COOH 
+  XHid;  and  so  mi  by  i=ineeessive  steps  to  tetraglycylglycin :  H2N.- 
(Cn2.CO.HX)4.0H2,i'<->OH.  i^irtius-  base,  a  jirodnct  of  tryptic  diges- 
tion, is  probably  hexaglycylglycin  ester^  H2N.(CH2X'O.NH)6X^H2*- 

These  syntheses  indicate  the  great  reactivity  of  the  amido  groo^^ 
in  these  compounds,  because  of  which,  also,  numerous  products  of 
substitution  arc  known,  and  the  esters/like  those  of  the  parent  amido* 
acids,  tend  to  form  cyclic  products  of  condensation.    Diglycylglyein 
forms  a  condensed  product  wliich  gives  the  biuret  reaction,  which  i^| 
also  given  by  triglycylglycio  and  the  higher  polypeptide*  ^^ 

Polypeptids  are  also  formed  with  other  amido -acids,  aspartic  acid, 
cystin,  phenylalanine  tyrosin,  and  w^ith  prolin  (p,  511).  JH 

Diamido   Fatty  Acids. — These   compounds   contain    two    ainidci^ 
groups,  attached  to  two  different  carbon  atoms.    Attempts  to  obtain 
diamido  acetic  acid,  t'H  (NH2)2. COOH  have  been  unsuccessful,  and  it 
is  assumed  that  in  these  acids  the  two  NH2  groups  are  always  attache 
to  different  carbon  atoms,  although  the  same  prohibition  in  this  regai 


NITBOGEN    DERIVATIVKS    OF    ACIDS 


417 


I 


not  in  general  apply  to  the  NH2  group  as  it  does  to  the  OH 
group  (p.  269),  as  in  shown  by  the  existenee  of  urea  and  gnanidiiK 
The  lowest  term  of  the  series  in  diamidopropionie  acid;  above  this 
there  may  exist  isomeres,  inereasiug  in  number  with  increase  in  the 
number  of  carbon  atoms,  dependent  npon  the  relative  positions  of  Ihe 
amido  groups  to  tlie  earbfixyl. 

They  are  formed  as  hydrobromids,  by  the  action  of  ammonia  upon 
the  corregpondint^  dibromo  fatty  acids.  Thus  a-^  dibromopropionic 
acid  yields  ^-ff  diamidopropionie  acid  hydrobromid:  C'HiBr^CHBr.' 
COOH+2NH.--CH.NH:;Br.CHNH3Br.cboH.  Froin  the  hydrobro- 
mids  or  hydrochlorids  the  free  acids  are  liberated  by  an  equivalent 
i^mouut  of  AgHO*  They  are  also  obtained  by  a  rather  intricate  synthesis, 
beginning  with  alkyl-malouic  derivatives  of  phthalimid  (p.  477). 

They  are  syrnps,  or  very  hygroscopic  crystals;  strongly  alkaline 
and  basic,  absorbing  OO2  from  air,  and  forming  crystalline  salts. 
With  benzovl  chlorid  thev  form  mono-  and  dibenzovl  derivatives » 
»ome  of  which  exist  in  nature.  They  form  crystalline  precipitates 
with  phosphotungstic  acid,  containing  an  asymmetric  carbon  atom; 
they  exist  in  optical  isomeres. 

The  dianiido  acids  are  chiefly  of  interest  in  connection  with  the 
hejcon  bases,  which  are  basic  substances  formed  during  the  develop- 
ment of  lupine  seeds »  and  by  hydrolysis  of  proteins  and  of  protamins 
(p.    588) ,  containing  six  carbon  atoms,  and  either  being  themselves,  or 
J^teldiug  on  decomposition,  acids  of  this  class:    Arginin,  CgHuNiOij^  a 
d&r*i  vative  of  diamidovalerianic  acid  (below),  lysin,  C6HuN'202»  which  is 
•  dimuidocaproTc  acid  (below),  and  histidin,  UeHgNriOs,  wdiicb  is  prob- 
•^'y  a  glyoxalin  derivative  (p.  516).    The  name  hexone  is  applied  to 
*ll     lasic,  nitrogenons  €e  compounds  formed  under  the  above  condi- 
H  tiotig^  and  includes  lencin  as  well  as  the  hexon  bases. 
ft        iDiamidopropionic  Acid — CH2NH2.CHNH2.COOH — is  obtained  as 
Hrtj^x^e   indicated.      Gaseous   HNO2   converts   it    into   glyceric   acid: 
^^3  J^H^CHNH2.C00H  +  2HN0i=  CH.OHCHOH.COOH  +  2N2  + 
1^   **fl^tO,  while  the  less  intense  action  of  AgNOs  converts  it  into  isoserin 
(p.  420):   CH2NH2.CHNH..COOH+AgN02=CHjNH2.CHOH.COOH 
+>^3+AgH0. 

t>iamidobotyric  Acids. — Two  are  possible,  derived  from  the  nor- 
®^^  butyric  acid,  and  two  from  the  iso  acid.  The  ^-y  normal  acid; 
CH->JH...CH2,CHNH2.COOH,  has  been  obtained  synthetically. 

l^iamido valerianic  Acids. ^ — Fourteen  are  possible »  derivable  from 
the  four  valerianic  acids.  Of  these  the  a-^normal  acid:  CH2NH2.- 
CHi.CH',.CHXPT2.C00H,  which  has  also  been  obtained  synthetically. 
i«  the  base  ornithin,  as  is  proven  by  its  method  of  synthesis,  and  by 
the  tact  that  nnder  the  influence  of  bacterial  action  it  forms  putres- 
m :  CH2NH2.CH2.CH2,CHNn,.COOn  =  HuNCII^CHjCH^CHj.- 
27 


I 


418  MANUAL    OF    CHEMISTRY 

NH2+CO2.  Ornithin  was  first  obtained  by  hydrolysis  of  its  dibenzoyl 
derivative,  omithuric  acid,  which  occurs  in  the  urine  of  hens  fed 
with  benzoic  acid  (p.  480).  Another  diamidovalerianic  acid  has  been 
obtained  synthetically,  which,  being  optically  inactive,  is  probably 
the  racemic  form  of  ornithin,  which  is  itself  dextrogjTous  [a]D=+ 
7.85°. 

Arginin — C6H14N4O2 — is  the  most  abundant  of  the  hexon  bases. 
It  was  first  obtained  from  the  seeds  of  Lupinus  albus^  in  which  it 
exists  preformed,  and  from  which  about  3.5  per  cent  can  be  ex- 
tracted by  water.  Subsequently  it  was  found  to  be  produced,  in 
larger  proportion  than  lysin  or  histidin,  by  hydrolysis  of  proteins 
and  protamins  by  boiling  with  HCl+SnCU,  and  also  by  tryptic  diges- 
tion of  fibrin. 

The  constitution  of  arginin  is  established  by  its  decomposition 
products  and  synthesis.  When  hydrolysed  by  BaH202,  it  yields  urea 
and  ornithin:  C6Hi4N402+H20=H2N.CO.NH2+CH2NH2.CH2.CH2. - 
CHNH2.COOH.  Conversely,  it  is  obtained  by  partial  synthesis 
from  ornithin  and  cyanamid:  CH2NH2.CH2.CH2.CHNH2.COOH+ 
CN.NH2=C6Hi4N402.  This  synthesis  closely  resembles  that  by  which 
creatin  (methylguanidin  acetic  acid)  is  produced  from  methyl- 
amidoacetic  acid  and  cyanamid:  CH2NH(CH3).COOH+CX.NH2= 
HN:C<^N(CHs).CH2.C00H-  -^.mong  the  products  of  oxidation  of  argi- 
nin by  various  oxidants  are:  a-amidovalerianic  acid:  CH8.CH2.CH2.- 
CHNH2.COOH;  y-guanidinbutyricacid:  HN:C<^jjh^qij^  ^g^  ^^^  qqq^; 
ethylene -succinic  acid:  COOH.CH2.CH2.COOH ;  and  guanidin: 
HN:C:(NH2)2.     The   structural   formula   of    arginin    is    therefore: 

HN:C<(nh!cH2.CH2.CH2.CHNH2.cooh»  a^d  it  is  a-amido-S-guanidin 
valerianic  acid.  It  may  also  be  considered  as  a  product  of  condensa- 
tion of  urea  and  a-8. diamidovalerianic  acid:jj^j^^CO+CH2NH2.CH2.- 

CH2.CHNH2.COOH=^N^C.NHCH2.CH2.CH2.CHNH2.COOH+H20. 

Arginin  crystallizes  in  plates  or  prisms,  f.  p.  207°,  odorless, 
slightly  bitter,  strongly  alkaline,  absorbs  CO2  from  air,  precipitates 
oxids  from  solutions  of  metallic  salts,  and  expels  NH3  from  ammonia- 
cal  salts,  easily  soluble  in  water,  almost  insoluble  in  alcohol. 

Diamidocaproi'c  Acids. — There  are  forty -nine  possible  diamido 
acids  derivable  from  the  seven  caproie  acids.  Of  these  lysin,  one  of  the 
hexon  bases,  is  thea-€-normal  acid:  CH2NH2.CH2.CH2.CH2.CHNH2.- 
COOH,  as  is  shown  by  its  conversion  into  pentamethylene  diamin 
(cadaverin)  by  bacterial  action:  CH2NH2.(CH2)3.CHNH2.COOH  = 
H2N.(CH2)5.NH2+C02;  and  by  its  synthesis  from  y-cyanopropyl- 
malonic  ester:   NC.(CH2)3.CH(COO.C2H.02.   It  is  probable  that  lysin 


Pbouen  derivatives  of  acids 


419 


may  form  a  giiauidiii  dinivative,  toiruilar  to  argiiiio,  but  it  is  still 
uukuowiK  On  the  otiier  hand,  its  dibenzoyi  derivative,  lysuric  acid, 
correeponding  to  uniithuric  and  hippuric  acids,  has  been  obtained  by 
the  action  of  benzoyl  chlorid  upon  lysin. 

The  supposed  hexon  base  lysatinin  is  a  mixture  of  arginin  andf 
lysin. 

Amido-dicarboxylic  Acids  are  derived  from  the  dicarboxylic  acids 
by  substitution  of  NII2  it)  a  hydrocarbon  group.  The  lowest  term  is 
therefore:  Amido-malonic  Acid— COOH.C^HNHi.COOH— a  syn- 
thetic product,  obtained  by  tlie  reduction  of  uitroKoujalonie  acid: 
COOHXH(NO).COOH  +  2H2^COOIi.CHNH2,COOH  +  HtjO,  which 
decomposes  easily  to  aniido- acetic  acid  and  carbon  dioxid:  UOOH.- 
CHNH2.COOH--CH3NH2.COOH  +  CO2. 

Amido-succinic  Acid  —  Aspartic  Acid— COOH.t'*HNH2*CH2.- 
COOH. — The  la^vo  acid  is  produced  during  tryptic  digestion  of  pro- 
teins, and  is  a  product  of  their  hydrolysis  by  dikite  acids.  It  exists 
tD  beet-root  vinasse.  and  is  obtained  from  many  vegetable  substances 
as  a  product  of  decomposition  of  its  amid,  asparagiu.  It  crystallizes  in 
rhombic  prisms,  difficnttly  soluble  in  cold  water,  readily  soluble  in  hot 
water*  Nitnms  acid  converts  it  into  1- malic  acid:  C'OOH.C*HNH2.- 
CH2.COOH  +  HNO2  ^COOH.C*HOH,CH2.C0OH  +  N2  +  H2O.  It 
forms  a  crystalline  compound  with  cupric  oxid,  which  is  soluble  in 
hot  water,  but  almost  insoluble  in  cold  water. 

Asparagins,— Amido-succinamic  Acids, —Amido-succinic  Amids* 
— Two  mo  nam  ids  are  derivable  from  aspartic  acid  or  from  sueciuamie 
acid  (p,  403):  a-asparagin,  CONHs^C^HNHo.CHo.COOH,  and  /3- 
asparagin,  COOH.C^HNHu.CH^.COXHa,  each  of  which  occurs  in 
optical  isomeres.  The  ^-amid  exists  in  both  d-  and  1- forms  in  many 
plants,  in  asparagus  and  in  the  sprouts  of  vetches,  beans  and  peas. 
The  Inform,  which  predominates  in  nature,  crystallizes  in  prisms, 
sparingly  soluble  in  water^  odorless,  faintly  nauseous  in  taste,  faintly 
acid  in  reaction.  The  d-^-amid  is  also  formed  by  heating  maleic  anhy- 

CH.CO 


drid  (p,  430) »  with  alcoholic  ammonia: 


"N 


0+2NH3=COOH.' 


ch.cq/ 

CHNH2.CH2.CONH2*  Asparagins  enter  into  unstable  combination 
with  both  bases  and  acids.  Hydrolysed  by  acids  or  alkalies  they  form 
aspartic  acid:  COOH.CHNH2.CH2  CO^'H2+H20=COOH.CHNH2.- 
CH2,COOH^-NH3.  Niti'ons  acid  converts  them  into  malic  acid: 
COOH.CHNH2.CH2.CONH2+2HN02=COOH.CHOH.CH2.COOH  + 
2N2+2H,0, 

Amido-glutaric  Acid,— Glutaminic  Acid.— The  d-acid,  which  ac- 
companies aspartic  acid  as  a  product  of  decomposition  of  the  proteins 
and  in  the  vegetables  mentioned,  is  the  d-a-acid:    COOH,CH2.CH2.- 


420 


MANUAL   OP    CHEMISTRY 


C*HNII  ..COOU.  The  /?-acid,  COOH.CHaX'HNHaXHs.COOH,  wbieh 
would  uot  form  ojitieal  isouieres,  does  not  api>^ar  to  exist.  The  a-at-id 
crystallizes  iu  rhonibic  octahedra,  soluble  in  but  water,  insoluble  iu 
alcohol  and  ether.  The  d-aeid  is  produced  by  hydrolysis  of  proteius 
by  acids;  but  the  i-aeid  is  fornied  when  Ball^Oj  is  the  hydrolysiug 
agent.  It  forms  a  crystalline  eompouud  with  H€l,  which  is  almost 
insoluble  in  the  concentrated  acid.  It  forms  a  crystalline  copper  salt. 
Glutaniin,  or  a-amidoglutaric-i-amid:  COOIl.CHi.CH2.C*UNH2.- 
CONH-i,  in  the  i-foroi,  accompanies  asparagin  in  the  vegetables  in 
which  it  occurs. 

M on amido-oxy acids — are  derivable  from  oxy acids  by  substitution 
of  NH2  for  H  in  a  hydrocarbon  group,  or  far  alcoholic  OH  in  acid^ 
containing  more  than  one  such  group. 

Amido-lactic  Acids, — ^Amido-glyceric  Acids. — Corresponding  to 
glyceric  acid:  CII:;.0H.C'*'I10FI>C00H,  are  two  monamido  acids: 
ci^CH20H.C*HNH>.(  OOH,  and  ^^-CHaNHs.C^nOH.COOH.  The 
former  is  also  amidohydracrylic,  or  a-amido-/^-oxypropionic  acid, 
and  the  latter  amido-lactic,  or  «-oxy-^-amidopropionic  acid*  The 
ii'amido  acid  is  serin,  a  product  of  decomposition  of  scricin  and  fibroin, 
constituents  of  silk,  and  of  other  proteids.  It  has  been  obtained  syu- 
thetieaUy  from  glycollic  aldehyde  and  hydrocyanic  acid:  CHsOII,- 
CHO+UNH+nsO^CILiOH.CHNHs.COOH,  Another  total  synthesis 
is  from  formic  ester  and  hippuric  ester  (p.  479),  which  are  first  eon- 
densed  to  formylhippuric  ester:  H.COCXCaHfl)  +CH>(NH/C0.C6HfJ  .- 
COOCCWs)  =CHO,CH(NH.CO.CflH5)X:O0(C2H5)  +CH3.CH2OH; 
this  is  then  reduced  to  nionobenzoyl- serin  ester,  which  by  hydrohsls 
yields  serin:  CH,OH.CH{NH.CO.CflH5).COO(C2H5)  +  2n26=  CH,- 
OH.CHNH2.COOH+CflH5.COOH+CH3.CH20H.  The  )3-acid  is  iso- 
serin,  obtained  by  the  action  of  ammonia  upon  ^-ehlorlaetic  acid: 
€H2CKCHOH.COOH+NH3  =  CH2NH2.C*HOH.COOH+HCL  Serin 
on  reduction  by  HI  yields  ordinary  alanin:  CHjOH.CHNH2.COOH  + 
H^i^CHa.CHNH^.COOH+H^O,  while  isoserin  yields  /?-amidopropiouie 
acid:  CH2NH2.CHOHCOOH+H2=CH2NH2.CH2.COOH+H20.  By 
the  action  of  nitrous  acid  both  are  converted  into  glyceric  acid: 
CHiOILCHNH2.COOH+HN02-=CH20H.CHOH.COOH  +  N2+H20 

ci  -  A  mi  do-y-oxy  valerianic  Acid  is  formed  from  hydrocyanic  acid 
and  secondary  aldol:  CKH+CH3.CHOH  GH^.CHO+HsO^CHs.C*- 
HOH.CH2.C*HNH2.COOH. 

Glucosamic  Acid  —  Tetroxy  *a  *  amidocaproic  Acid  —  CH2OH ,  - 
(CH0H}3.CHNH.i.C00H— corresponding  to  glueosamin  (p.  387), 
has  been  obtained  from  cartilage. 

Amido  acids  corresponding  to  the  aldehyde  acids  and  the  ketone 
acids  are  not  known,  although  <i-amido-acetoacctic  ester:  CH3.CO** 
CHNH3.COO(C2H5),  has  been  obtained. 


NITROGEN    DERIVATIVES    OF    ACIDS 


421 


Amido-thioacids. — The  fallowing  amido  tlerivatives  of  thioacids 
are  of  physiological  interest: 

Amido-isethionic  Acid, — ^Amido-ethylsulfonic  Acid, — Taurin, — 

CHj.NHj 

CH2NH2.CH2SO3H — or  I       I      the  araido  derivative  of  isethionic,  or 
CHiSOs 

ox.vethyl  sulfonic  acid  (p.  372),  CH2OH.CH2SO3H,  occurs  in  bile,  in 
combination  with  cholic  acid,  as  taurocholic  acid,  from  which  it  may 
be  obtained  by  decomposition  by  HCL  It  is  also  produced  by  deconipo- 
flition  of  auiido-sulfopropionic  acid,  a  product  of  oxidation  of  protein 
cystin:  COOH.CHNH2-CH2S03H=C02+CH2NH2.CHjS03H.  It  is 
formed  synthetically  by  beating  together  chlorethylsulfonic  acid  and 
ammonia:  CH2C1.CH2S03H+NH3-=CH2NH.A  HiSO^H+HCl;  or  by 
heating  ammonium  oxethylsulfonate:  CH20H.CH2*80:i(NH4)— CH3- 
NH2.CH2.8O3H  +  H2O. 

Taurin  crystallizes  in  large,  oblique  rhombic  prisms,  soluble  in 
water,  insoluble  in  alcohol  and  ether.  It  appears  in  the  urine  partly 
in  its  own  form,  and  partly  c{*mbiiied  with  carbamic  acid  as  taurocar* 
bamic  acid:  H2N.0O.NHCn2.CH2SOaH.  It  also  combines  with 
sodium  cholate  to  form  taurocholic  acid  (p.  640).  It  differs  from  other 
amido  acids  in  that  it  forms  no  salts  with  acids,  and  forms  neither 
benzoyl  nor  acetyl  derivative,  which  facts  point  toward  the  cyclic 
salt  constitution  shown  in  the  second  formula  above.  Its  acid  function 
is  more  marked.  It  forms  compounds  with  metallic  oxids.  That  of 
mercury  is  formed  by  boiling  tannu  j^olutinn  with  freshly  precipitated 
'^mercuric  oxid,  aud  is  white  and  insoluble*  Taurin  and  cyanamid 
combine  to  form  taurocyanamin,  or  tauroglyeocyanamiti,  cor- 
responding  to  creatin    (p.    m9)i     CH2NH2.CH2SO3H  +  HsN.CN^^ 

HN:C<^j^fj*(>U,  (^U^gQ^j|.  Nitrous  acid  converts  it  into  isethionic  acid: 
CH2NH2.CH2SbaH+nN02=CH20II.CH2SO:^H+N2+H.O.  Its  sulfur 
is  not  split  off  by  boiling  alkaline  solutions,  but  it  is  by  fusion  with 
caustic  potash :  CH2NH2.CH2SOaH  +  2KH0  =  CH3.CO0HH-K2HO3  + 
XHa+H2. 

Amido-thiolactic  Acids*  — Of  the  two  possible  thioacids  corre- 
sponding to  serin  and  isoserin  {p.  420)  that  derivable  from  the  former 
and  from  hydracrylic,  or  ^- lactic,  acid,  is  known  as  cystein,  which  is 

Ia-amido — y3-thiolactic  acid  (formula,  p.  422),  Cyste'in  is  obtained 
by  the  action  of  nascent  hydrogen  upon  cystin,  and  is  formed  by  an 
additional  step  to  the  synthesis  of  serin;  the  benzoyl-seriu  ester  {p. 
420)  is  converted  into  eystein  by  P2S5.  When  oxidized  by  Br,  it 
prodacea  cystcic  acid,  or  a-amido  —  ^-sulfopropionic  acid,  which^ 
|ytfaoa^h  containing  both  sulfonic  and  carboxyl  groups,  is  monobasic. 
X^y^teif^  forms  benzoyl  and  alkyl  and  phenyl  derivatives,  the  latter  by 
substitution   for  II  in   SIL     Although  eystcin   is  not   produced  by 


^i 


422  MANUAL    OF    CHEMISTRY 

hydrolysis  of  proteins,  in  which  the  S  exists  in  eystin,  not  in  cystein, 
it  is  eliminated  in  a  "protected"  form  of  combination  by  dogs  after 
administration  of  benzene  halids.  These  compounds,  in  which  tbe 
phenylene-halid  group  takes  the  place  of  H  in  HS,  and  acetyl  is  sub- 
stituted for  H  in  NH2,  are  called  mercapturic  acids.  Cysteic  acid  by 
loss  of  CO2  forms  taurin. 

Cystin,  which  is  a-diamido — jS-dithiodilactic  acid,  occurs  in  uri- 
nary sediments  and  calculi,  and  is  formed  by  hydrolysis  of  many  pro- 
teins, in  greatest  abundance  from  hair,  horns,  hoofs,  and  is  similarly 
produced  in  the  system  and  appears  in  the  urine  in  "cystinuria."  It 
crystallizes  in  thin,  six-sided  plates,  insoluble  in  water,  alcohol, 
ether,  or  acetic  acid,  soluble  in  mineral  acids  and  alkalies. 

CH2SH.CH2.COOH  CH2SO3H.CHNHj.COOH 

Serin.  Oyiteic  acid. 

CHaSH.CHNH2.COOH  HOOC.CHNH2.CH2S.SCH2.CHNH5.OOOH 

Cystein.  Cyrtin. 

CH2SO3H.CH2NH2  CH2S  (C6H4 .  Br  KCHNH(C0.0H3  ).COOH 

Tanrin.  Brommereapturie  acid. 


PHOSPHORUS,  ANTIMONY,  AND  ARSENIC  DERIVATIVB& 

Many  organic  compounds,  similar  to  those  containing  nitrogen,  in 
which  that  element  is  replaced  by  phosphorus,  antimony,  or  arsenic, 
are  known.     Of  these  only  a  few  arsenic  derivatives  require  mention. 

Dimethyl  Arsin — (CH3)2HA8 — corresponding  to  dimethyl  arain, 
(CH3)2HN,  is  a  colorless  liquid,  having  an  intensely  disagreeable 
odor,  which  iprnites  spontaneonsly  in  air.  It  may  be  considered  as 
the  hydrid  of  a  radical,  (GH3)2As,  which,  from  the  disagreeable  odor 
and  intensely  poisonous  action  of  all  of  its  compounds,  has  received 
the  name  cacodyl  ('fa'fos=evil).  As  the  amins  are  considered  as 
derived  from  ammonia  by  substitution  of  alkyl  groups  for  the 
hydrogen,  so  the  compounds  of  which  this  is  a  type  are  derived  from 
the  corresponding  hydrogen  compounds  of  phosphorus,  antimony,  and 
arsenic,  and  are  called  phosphins,  stibins,  and  arsins. 

The  parent  substance  of  the  arseno- organic  compounds  is  a 
fuming,  foul-smelling  liquid,  obtained  by  distilling  a  mixture  of 
arsenic  trioxid  and  potassium  acetate,  and  called  fuming  liquid  of 
Cadet.  The  principal  constituent  of  this  is  cacodyl  oxid,  or  alkarsin^ 
(CH3)2As/^»  a  liquid  which  boils  at  120''  (248''  F.),  insoluble  in  water, 
soluble  in  alcohol  and  in  ether.  Cacodyl,  or  dicacodyl,  (CH3)2  As.- 
As(CH3)2  is  a  colorless,  insoluble  liquid,  which  boils  at  170°(338°P.), 
and  ignites  spontaneously  in  air.     Cacodyl  and  all  of  its  compounds 


UNSATURATED    ALIPHATIC    COMPOUNDS  41!3 

are  ezceediugly  poisopons,  especially  the  cyanid,  an  ethereal,  volatile 
liquid  the  presence  of  whose  vapor  in  air,  even  in  minnte  traces,  pro- 
daces  symptoms  referable  both  to  arsenic  and  to  cyanogen.  Prob- 
ably minnte  quantities  of  arsins  are  formed  during  the  putrefaction 
of  cadavers  embalmed  with  arsenical  liquids. 

UNSATURATED    ALIPHATIC   COMPOUNDS. 

In  this  class  are  included  all  open  chain  carbon  compounds  in 
which  two  carbon  atoms  exchange  more  than  one  valence  (p.  268). 
As  the  saturated  compounds  consist  of  the  members  of  the  first, 
or  methane,  series  of  hydrocarbons  and  their  derivatives,  so  the  un- 
saturated compounds  are  the  remaining  series  of  open  chain  hydro- 
carbons and  their  unsaturated  derivatives  (p.  273). 

HYDROCARBONS,  ETHENE,  OR  OLEFIN  SERIES. 

The  members  of  this  series  contain  two  atoms  of  carbon  less  than 
the  corresponding  terms  of  the  methane  series.  They  may  be  modi- 
fied by  addition,  behaving  as  bivalent  radicals,  as  well  as  by  substitu- 
tion.    Their  "  Geneva  "  names  terminate  in  cnc. 

Ethene — Ethylene — Olefiant  gas  —  Olefin  — Elayl — Heavy  carbu- 
retted  hydrogen — CH2:CH2 — is  formed  by  the  dry  distillation  of  fats, 
resins,  wood,  and  coal,  and  is  a  valuable  constituent  of  illuminating 

It  is  formed  synthetically:  (1)  By  heating  a  mixture  of  alcohol, 
H2SO4  and  sand.  In  this  reaction  ethyl -sulfuric  acid  is  formed  and 
decomposed:  C2H5.HS04=H2S04+CH2:CH2.  (2)  By  the  action  of 
<»n8tic  potash  upon  ethyl  bromid:  CH8.CH2Br+KHO=KBr+H20+ 
CH2:CH2.  (3)  By  heating  together  acetylene  and  hydrogen,  or  by 
the  action  of  nascent  hydrogen  upon  copper  acetylid  :  CH:CH+H2= 
CH2:  CH2,  or  C2Cu2+2H2=CH2:  CH2+2CU.  (4)  By  heating  methylene 
iodid  with  copper:  2CH2l2+2Cu=CH2:CH2+2Cul2.  (5)  By  the 
action  of  sodium  or  of  zinc  upon  ethylene  chlorid  or  bromid:  CH2CI.- 
CH2Cl+Na2=CH2:CH2+2NaCl,  or  CH2Br.CH2Br+Zn=CH2:CH2+ 
ZnBr2. 

It  is  a  colorless  gas,  tasteless,  lias  a  faint  odor  of  salt  water,  spar- 
ingly soluble  in  water.  Its  critical  temperature  is  13°  (55.4°  F.) ;  its 
critical  pressure  60  atmospheres.     It  boils  at  — 105°  ( — 157°  F.). 

It  burns  with  luminous  flame,  and  forms  explosive  mixtures  with 
air.  By  long  contact  with  a  red-hot  surface  it  is  decomposed  into 
acetylene,  methane,  ethane,  a  tarry  product,  and  carbon.  It  unites 
with  hydrogen  to  form  ethane,  C'oHe;  with  oxygen  it  unites  explo- 
sively on  approach  of  flame,  to  form  carbon  dioxid  and  water.     It 


MANUAL    OF    CHEMISTRY 

combiDes  with  hydrobromic  and  hydriodic  acids  to  form  ethyl  broraid» 
CaH^Br,  and  ethyl  iodid,  C2H5I.  It  combiiies  with  sulfuric  acid  to 
form  ethyl -sulfuric  acid:  CH3  :CH2+H2S04^C2H5.HS04.  Mixtures 
of  ethene  and  ehloriii  explode^  with  copious  deposition  of  carbon,  on 
approach  of  flame.  In  diffuse  daylight  they  unite  glowly,  with  sepa- 
ration of  an  oily  liquidi  ethylene  chlorid,  or  dutch  liquid*  CH3CL- 
CH2CK  to  whose  formation  the  name  "olefiant  gas"  is  due  (p.  304). 
The  same  compound  is  formed  when  ethene  is  passed  through  a  mix- 
ture of  MnOa,  XaCl,  H2SO4,  and  H2O*  When  passed  through  alka- 
line solution  of  potassium  perraangauate,  it  is  oxidized  to  oxalic  acid 
and  water:  2CH2:CH2+502=2COOH.COOH+2H20;  or,  by  careful 
oxidation  by  dilute  sohition  of  the  same  agent,  it  forms  ethene  glycol : 
2CHoiCH2+2H20+Oi=2CH20H.CH20H  (p.  295). 

When  inhaled,  diluted  with  air,  ethene  produces  effects  somewhat 
similar  to  those  of  nitrous  oxid. 

T  wo  groupings  of  (C2H4)  "are  possible, — CH2.CH2—,andCH3.CH=^, 
the  former  produced  by  the  breaking  of  the  double  bond  between  the 
carbon  atoms  in  ethene,  the  latter  by  double  substitution  in  ethane. 
Compounds  containing  the  groupiiig-'CH2-CH2^are  designated  as 
ethylene  or  ethene  compounds,  e.  g,,  ethylene  chlorid,  ClCHg.- 
CH2CI,  b.  p.  84*^,  those  containing  the  grouping  CH3.CH=  are  called 
ethldene  or  ethylidene  compounds,  e.  g,,  ethidene  chlorid,  CHs^- 
CHCls,  b.  p.  5S°. 

Hoinologues  of  Ethene,— The  superior  homolognes  of  ethene 
exist  in  coal  gas  and  coal  tar.  They  are  formed  by  the  methods  1 
and  2,  used  for  the  preparation  of  ethene,  but  starting  from  the  cor- 
responding superior  monoatomic  alcohol,  The  lower  terms  are  gas- 
eous, the  higher  liquid  at  the  ordinary  temperature.  They  undergo 
reactions  similar  to  those  of  ethene,  and  in  addition »  readily  poly- 
merize under  the  iutluence  of  sulfuric  acid,  ginc  chlorid  and  other 
substances. 


ETHINE,    OR    ACETYLEKE    SERIES. 

Acetylene — Ethine — HC  :  CH^ — exists  in  coal  gas,  and  is  formed  in 
the  decomposition,  by  heat  or  otherwise,  of  many  organic  substances. 
It  is  formed:  (1)  By  passing  an  electric  arc  in  an  atmosphere  of 
hydrogen:  2C+H2—CH  :CH.  This  is  the  only  known  synthesis  of  a 
hydrocarbon  direetl}'  from  the  elements,  (2)  By  the  action  of  water 
upon  calcium  carbid  ;  C2Ca+2H20=HC  :  CH+CaH202.  This  method 
is  used  industrially  for  the  preparation  of  acetyleue  for  use  as  an  ilUi- 
minating  gas.  (8)  By  beating  chloroform,  broraoform  or  iodoform 
with  sodium,  copper,  silver  or  zinc:  2CHCl3-f  3Na2=6Na01+HC  :  CH. 
(4)  By  heating  ethylene  broraid  with  caustic  potash.     The  reaction 


UNSATURATED    ALIPHATIC    COMPOUNDS 


425 


f occurs  in  two  phases,  vinyl  bromid  beiug  formed  as  an  intermediate 
product :  CH2Br,CH2Br  +  KHO  =  CHBrrCHs  +  EBr  +  H/0,  and 
CHBr:CH2+KH0=CH  :CH+KBr+H20. 

Acetylene  is  a  colorless  gas,  rather  soluble  in  water,  having  a  pe- 
culiar, disagreeable  odor,  that  which  is  observed  when  a  Bunsen 
burner  burns  within  the  tube.  It  is  liquefied  by  a  pressure  of  48 
atmospheres  at  0°  (32°  F.).  It  forms  explosive  mixtures  with  air  or 
oxygen.  In  contact  with  a  red -hot  surface,  and  in  al>seuce  of  air,  it 
polymerizes  to  benzene  3C2H2=CflH6,  an  action  which  accounts  for 
the  presence  of  benzene  in  gas  tar,  and  which  is  of  great  interest  iu 

.  connection  with  the  relations  between  the  open  chain  and  the  closed 

I  compounds  (p.  433).  Nascent  hydrogen  converts  aeetyleoe  into 
etheue,  C^Hi,  and  then  into  ethane,  C2H6.  Under  the  influence  of  the 
electric  discharge,  it  combines  with  nitrogen  to  form  hydrocyanic 
acid:    C2H2+N2=2CXH.     It  combines  with  HCl    and  with   HI    to 

(form  ethidene  chlorid,  CHfj.CHClo,  or  iodid,  Cn3.CHl2.  Mixed 
with  chlorin  it  detonates  violently  iu  diffuse  daylight.  The  hydro- 
gen atoms  of  acetylene  may  be  replaced  l>y  metals  to  form  accty- 
lids,  or  carbids.  Sodium  and  calcium  acetylids  ai'e  stal)le  at 
high  temperatures ^  but  are  decomposed  by  water  with  formation 
of    acetylene.      Silver    and    copper    acetylids    are    highly    explo- 

Irive  when  dry,  and  explosions  which  have  occurred  when  illumi- 
nating gas  was  in  contact  with  brass  or  copper  were  probably  due 
to  the  formation  of  the  latter.  The  formation  of  copper  acety- 
Hd,  which  separates  as  a  blood •  red  precipitate  when  acetylene  is 
conducted  through  a  solution  of  cuprous  chlorid,  is  utilized  as  a  test 
for  the  presence  of  acetylene.  Acetylene  mercuric  chlorid,  CV 
(Hg€l)2t  separates  as  a  nou- explosive,  white  preeipitate  when  aeety- 
leoe is  passed  through  a  solution  of  mercuric  chlorid. 


DIOLEPIN    AND    SUPERIOR    SERIES, 

The  diolefins  are  isomeric  with  the  hydrocarbons  of  the  acetylene 
series,  containing  two  double  linkages,  in  place  of  one  triple  linkage* 
Thus  allene.  or  allylcnc,  CH2:C:CH'2,  is  isomeric  with  propine,  or 
propylene.  CH  i  C.CH3, 

Trimethyl-cthylene  —  Penten e  — .4 my  kne—  Vahren e —  ( CH;j ) 2 :  C :  - 
CH.CHs^is  a  colorless,  mobile  liquid,  boiling  at  39 "^  (102.2"  FJ, 
obtained  by  heating  alcohol  with  a  concentrated  solution  of  zinc 
chlorid.  It  is  used  as  an  aiHPsthftic,  and  in  the  preparation  of  ter- 
tiar>-  amylic  alcohol  (p.  21*4).    Higher  series,  p.  273. 

Olefin  Terpenes — Terpcnogcns.^  While  most  essential  oils  and 
other  aromatic  substances  are  rlc»sed  chain  compounds,  some  ethereal 
oils  L'ontain  or  yield  unsaturated,  open  chain  hydrocarbons,  alcuhuis, 


426 


MANUAL    OF    CHEMISTRY 


aldehydes  or  acids.  Araou^  the  hydrocarbons  are  myrcene,  and  an- 
hydrogeraniol,  CioHiu,  the  former  obtained  from  bay- oil »  the  latter 
from  oil  of  geranium.  Isoprene,  a  product  of  distillation  of  eaoot- 
ehone,  a  liquid  boiling  at  37°  (98.6°  F.)»  is  probably  methyl- divinyli 


CH,\, 


C.CH:CH2 


UNSATURATED    HALOGEN    DERIVATIVES. 


d 


These  cannot  be  formed  directly,  because  addition  products,  such  &b 
ethylene  chlorid,  are  formed  in  preference:  CH-jrOHs+Cls^CH-CL- 
I'lIjC!.  Bnt,  by  indirect  methods,  halogen  derivatives  of  both  ole- 
fins and  acetylenes  have  been  obtained,  such  as  vinyl  chlorid,  CHa:* 
€HCl»  and  vinyl  bromid,  CHi'iCITBr.  The  pmpylene  derivatives  are 
a  CH3.CH:CHCI,  p  CH3.CC1:CH2,  or  y  CH3CI.CH^CH3,  according  to 
the  position  of  the  substitution.  fl 

Tlie   y   derivative;*   are   the  allyl  halids,  corresponding  to  allylic 
alcohol.    Allyl  iodide  CnirLCH:Cll2.  and  bromid  are  frequently  used 
in  syntheses.    They  are  prepared  by  the  aetiou  of  hydriodic  acid,  or 
of  iodin  and  phoKphorus  upon   glycerol:    CHiOH.CHOH.CPl-iOH+ _ 
3HI^CH,rCH:Cn.i+3HL^O-fl2,    aud  CH20H.(^HOH.CH20H+PBrsJ 
^Cn-J^r.CH :  t;H2+n^iPOB+Br3. 

Convs|)ondiiig  to  allyl  iodid,  but  referable  to  propylene,  are 
propargyl  iodid  and  chlorid,  CH:C.CH2l  and  CHC.CHaCl,  the 
hitter  i)roduced  by  the  action  of  phosphorus  ti*ichlorid  upon  pro- 
pargyl  alcohol  (p.  427). 


I 


UNSATURATED  OXIDATION  PRODUCTS  OF  UNSATURATED   HYDROCARBONi 

Like  the  paraffins,  the  olefins,  acetylenes,  diolefios,  etc.,  yield 
alcohols,  aldehydes,  ketones,  acids,  oxids  and  esters  (p,  282), 

Vinyl  Alcohol— Cn2.CH. OH— the  simplest  of  the  olefin  alcohols, 
is  known  only  in  a  mercury  compound.  Although  the  radical,  vinyl, 
CH^tCH,  is  known  in  other  compounds  {see  Neurin,  p.  r384),  there 
is  utouiie  transposition,  with  formation  of  aldeliyde,  CH3CHO,  under 
coudUious  in  which  vinyl  alcohol  uiight  be  formed. 

Allyl  Alcohol— CH2: OH. CII2OII— is  formed:  (1)  By  the  action^ 
of  sodium  upon  dichlorhydriu:  CH2CLCHCLCH2OH  +  Naa  ^  CHst^ 
OH.rH20H+2NaCl;  (2)  by  heatincr  allyl  iodid  with  water:  CH2: 
CH.CHil+H^O^CH^  :CH.CH20n  +  ni;  (3)  by  reduction  of 
acrolein  by  nascent  hydrogen :  CRy,  CH.CH04-H2=CH2:  CH.CH2OH; 
(4)  by  heating  glycerol  with  formic  acid,  which  first  forms  a  glycerol 
ester,  which  then  splits  to  allylic  alcohol,  carbon  dioxid  and  water: 
CH20n.CHOII.CH2{OOC.H)=CH20H,CH:CH2+C02+H20.  Oxalic 
acid,  which  yields  formic  acid,  may  be  used  in  place  of  the  latter. 


UNSATURATED    ALIPHATIC    COMPOUNDS 


427 


It  is  a  colorless,  mobile  liquid,  solidifies  at  — *50°  (  — 58°  FJ, 
boils  at  97"*  (206. 6''  PJ.  sp.  ^r.  0.8507  at  25°  (77^  F,),  soluble  in 
water,  has  an  odor  reBenibliog  the  oombined  odors  of  alcohol  and 
essence  of  mustard,  burns  with  a  lamiiious  iiame.  It  is  isomeric 
with  propylic  aldehyde  and  with  acetone.  Oxidizing  agents,  such  as 
silver  oxid,  convert  it  first  into  the  correspondino^  aldehyde*  acrolein, 
then  into  the  acid,  acrylic  acid*  It  does  not  unite  readily  with 
hydrogen,  but,  in  presence  of  nascent  H,  union  takes  place  slowly, 
with  formation  of  normal  projjyl  alcohol.  It  forms  products  of 
addition  with  ehlorin,  lu-omin  and  iodiu,  similar  to  those  derived 
from  glycerol.  Substitution  couiponnds  have  also  been  obtained, 
such  as  «  bromallyl  alcohol,  CHj :  CBr.CH20H,  derived  fi*oni  /3  di- 
bromo-propylene,  CHj:  CBr.CH^Br. 

Propargyl  Alcohol  — CH-  C.CH2OH  — first  of  the  acetylene 
alcohols,  is  formed  by  the  itction  of  caustic  potash  upon  abronirtllyl 
alcohol :    CH,:CBr.CH20H  +  KHO  =  CH  '■  C.CIT2OH  +  KBr  +  HjO. 

Rhodinol  — C10H20O  — b.  p.  114°;  geraniol.  Ci.iHihO,  b.  p.  120''; 
and  linalool,  CuJluJiO,  b.  p.  lOH^ai^e  diolefin  alcohols,  which  are  the 
chief  constituents  of  the  essential  oils  of  rose,  geranium,  pelargonium, 
lavender,  bergamot,  etc. 

Acrylic  Aldehyde- Acrolcm  —  CHo^CH.CHO  — the  first  of  the 
series  of  olefin  aldehydes,  is  the  substance  which  (nuises  the  disagree- 
able odor  developed  when  fats  or  oils  are  overheated.  It  is  formed  : 
(1)  By  oxidation  of  alhiic  alcohol;  (2)  by  distilling  glycerol  with 
strong  H28O4  or  with  KHSO^r  CH20H.CHOH,CH20H=CH2:CH.- 
CHO  +  2HsO. 

Acrolein  is  a  colorless  liquid,  having  a  pungent  odor,  and  giving 
aflf  a  vapor  which  is  intensely  irritating;  sp.  gr.  0.841  at  20° 
(68  °F.),  boils  at  52''  (125.6°^F.),  soluble  in  2-3  parts  of  water. 
Oxidizing  agents  convert  it  into  acrylic  acid.  Nascent  hydrogen 
rednees  it  to  allyl  alcohol.  It  does  not  combine  with  alkaline  bisul- 
ilteift*  It  reduces  animoniacal  silver  nitrate  solution  as  does  acetic 
'  aldehyde.  It  suffers  change  even  when  kept  in  closed  vessels,  and 
dppiisits  a  white,  flocculent  material,  which  is  called  disacryl, 
while  form  if/,  acetic  and  acrylic  acids  are  also  produced. 

Croton  Aldehyde  — CH:i.CH:Cil.CHO.— By  the  aftion  of  diffuse 
daylight  upon  a  itiixture  'if  acetic  aldehyde,  H^O  and  HCl,  mi  oily 
lii|nid  is  slowly  fornicd,  which  consists  chiefly  of  aldol,  ur  l^oxy- 
butyraldehyde,  ClbuCllOILCH^AlIO.  This,  when  heuted,  is  de* 
cdfupcjsed  into  rrotou  aldehyde  and  water:  CHii*CH0H.tH2.CHU  = 
CHaX'H:CH.CnO  +  H,0. 

Croton  aldehyde  is  a  colorless  liquid;  boils  at  105^  (221*^  F,), 
gives  oflf  hi^Hily  irntr.ting  vaptirs:  sp.  ^r.  1.033  at  0^  (32^  F.).  It 
i«  reduced  by  nascent  II  to  crotonyl  alcohol,  Cn;;.Cli:ClLCIl'iOH. 


428 


MANUAL   OP   CHEMISTRY 


Propargyl  Aldehyde  — CH  ;  C.CHO — is  an  acetylene  aldehyde, 
a  liquid,  wbiuh  boils  at  39''  (138, 2"^  Fj. 

Citronellal*  CiuHtgOi  b.  p.  104"^,  is  an  olefin  aldehyde,  existing  in 
citronella  and  otlier  essential  oils.  Geranial,  CioHwO,  b.  p.  226*^,  is 
a  diolefin  aldehyde  existing  in  lomon  oil,  and  formed  from  geraniol. 

Mesityl  Oxid,  (CH3)2C:CH,CO.CE3,  and  Phorone,  (CH3)tiC  : 
CH.CO,CH:C(CH3)2t  are  examples^  respectively,  of  olefin  and 
diolefin  ketones.  They  are  prod  need  together  by  the  aetion  of 
dehydrating  agents,  su(?h  as  H^jSOi  and  Z0CI2,  upon  aeetone.  Mesityl 
oxid  is  a  liquid,  boiling  at  130°,  and  having  the  odor  of  peppermint. 
Phorone  is  a  solid,  fusing  at  28^,  and  boiling  at  196°.  Methyl- 
heptenone,  (CHsJaCiCH.CHs.CHs.CO.CHa,  another  olefin  ketone,  is 
a  liquid  having  a  penetrating  odor,  boiling  at  173°,  which  exists  in, 
or  is  produced  from,  many  essential  oils. 

Oleic  Acids. — The  acids  of  this  series  are  monocarboxylic  acids 
derived  from  the  olefins,  and  contain  two  atoms  of  hydrogen  less 
tlmn  the  corresponding  terras  of  the  acetic  series.  They  are  formed: 
(1)  By  oxidation  of  their  eorresponding  alcohols  or  aldehydes.  Thns 
allylie  alcohol,  CH-tCH.CH.OH,  or  acrolein,  CEsrCH.CHO,  yield 
acrylic  acid,  CH2:CH.C00H;  (2)  by  the  action  of  alcoholic  KHO 
upon  the  mo  no  halogen  fatty  acids.  Thus  P  monobrorao  propionic 
acid  yields  acrylic  acid:  CH2Br.CH2.COOH  +  KHO -- CH2  :  CH.- 
COOH  +  KBr  +  H2O;  (3)  by  dehydration  of  acids  of  the  oxy acetic 
series.  Thus  ethylene  lactic  acid  (P  oxypropionic.  p.  342)  forms 
acrylic  acid  when  heated:  CH20H.CH2.COOH  =  CH2:CHXX)OH + 
H2O;  (4)  from  the  allyl  halids  {p.  426),  by  conversion  into  eyanids 
and  saponification.  Thus  crotonic  acid  is  obtained  from  allyl  iodid: 
CH2:Cn.CH2l  +  KCN  =  CH2:Cn.CH2CN  +  KI,  and  CH2:CH  CH2- 
CN  +  2H20  +  HCl  =  CH2:CH,CH2.COOH  +  NH4Cl  (p.  328). 

The  oleic  acids  combine  with  the  hydracids  to  form  monohalogen 
fatty  acids,  the  halogen  assuming  the  position  furthest  removed  from 
the  carboxyl.  Thus  acr>^lic  acid  and  hydr iodic  acid  form  fi  iodo 
propionic  acid:  CH2:CH.C00H  +  HI  =  CH2LCH2.C00H.  Heated 
with  caustic  alkalies  to  100*^,  they  form  oxy  acids.  Thns  acrylic  acid 
forms  a  lactic  acid:  CH2:CH.C00H  +  KHO  =  CH3.CHOH.COOK. 
But,  when  fused  with  caustic  alkalies,  they  are  decomposed  into 
fatty  acids,  with  loss  of  H.  Thus  acrylic  acid  yields  formic  and 
acetic  acids:  CH2:CH.COOH+2KHO -^ H.COOK+CH3.COOK+H2. 
The  Py  acids,  i,  e.,  those  in  which  the  double  bond  is  between  the 
^  and  7  positions,  as  in  ethidene  propionic  acid,  CH:j.CH:CH,CHa. 
COOH,  when  heated  with  HjS04  form  lactones  (p.  368). 

Acrylic  Acid — CHstCH.COOH — -is  best  obtained  by  oxidizing 
acrolein  with  silver  oxid.     It  is  a  liquid  below  7^  (44.6°  FJ,  boils 


UNSATL^tATED    ALIPHATIC    COMPOUNDS 


429 


at  140°  (281'^  FJ,  mixes  with  water,  aud  has  an  odor  like  that  of 
acetic  aeid. 

Crotonic    Acids. — Three    crotonic    acids    are    known,    two    of 
which  are  space  isomerids  (pp.  311,  430 )r  Ordinary  crotonic  acid, 


CHj.  >COOH 


a  crystalline   solid,  fusible  at  72^   {161.6''  F  J ; 


isocrotonic  acid,         y 


\n.n/ 


C:C 


\ 


COOH 
H 


,  a  liquid  boiling  at  75''  (167'^  F.), 


and  mcthacrylic  acid,  CH2:C<^qj£^  ,  a  crystalline  solid,  f.  p,  16°, 
b.  p.  160". 

Angelic  Acid— ci3)>C:C<(?^^— is  a  crystalline  solid,  f.  p.  45°, 
b.  p.  185^,  having  an  aromatic  odor,  soluble  in  water,  alcohol  and 
ether.  It  exists  free  in  angelica  root,  and,  in  its  esters,  in  oil  of 
cumin  and  in  oil  of  anthemis,    Tiglic  acid — Methyl-crotonic  acid  — 

CH3.CH:C\^(-H3  ^"'isomeric  with  angelic  aeid,  exists  as  a  glycerid  in 
croton  oiU  and,  as  its  amyl  ester,  in  oil  of  cuinin.  It  is  a  crystalline 
solid,  f.  p,  60°,  b.p^  1S>^^ 

Hypogscic  Acid  —  C15H2D.COOH  —  accompanies  arachic  acid 
(p.  334;  as  its  glycerid,  in  peanut  oil.  It  is  a  crystalline  solid, 
f.p,  33°,  b.  p.  236°. 

Oleic  Acid  — CH3.(CH2)7.CH:CH.{CH2)7.COOH  — exists  as  its 
glyceric  ester  in  fats  and  fixed  oils,  and  is  obtained  in  an  impulse 
form,  on  a  large  scale,  as  a  by-product  in  the  manufacture  of  stearin 
candles. 

Pure  oleic  acicl  is  a  white,  pearly,  crystalline  solid,  fuses  at  14° 
(57.2°  FJ,  odorless,  tastrcless,  soluble  in  alcohol  and  in  ether,  insol- 
uble in  water,  sp.  gr.  0.808  at  19°  (66:2°  F.),  and  neutral  in  reaction. 
Exposed  to  air^  the  liquid  acid  absorbs  oxygen,  and  beconies  yellow, 
rancid  in  taste  and  odor,  acid  in  reaction,  and  incapable  of  solidifi* 
cation  on  cooling.  Nitric  acid  oxidizes  it,  with  formation  of  the 
lower  fatty  acids  and  sebacic  acid,  CioHisOj.  Heated  to  200° 
(392°  F.)  with  excess  of  caustic  potash,  it  is  split  into  palmitic  and 
acetic  acids:  CigHa^Oa  +  2KH0  -=  CieHnO-K  +  CsHjjO^K  +  H^.  The 
oIeat4?s  of  the  alkaline  metals  are  soft,  soluble  soaps;  those  of  the 
earthy  metals  are  insoluble  in  water.  The  action  of  iodin  and  of 
bromin  upon  oleic  acid  is  utilized  in  the  analysis  of  fats  and  oils. 
At  the  ordinary  temperature  the  fatty  acids,  including  pulontic  and 
ateuric,  are  not  aifected  by  iodin,  but  the  double  boud  in  oleic  acid 
ia  broken,  and  one  molecule  of  oleic  acid  combiues  with  two  atoraa 
of  iodin.  Under  like  conditions  each  molecule  of  linoleic  acid  (see 
below)  takes  up  four  atoms  of  iodin.  The  amount  of  iodin  which  a 
given  weight  of  a  fat  or  oil  can  combine  with  will  increase  with  its 
tenure  of   oleic^  or,  particularly,  of   linoleic  acid.      '^Hubrs   iodin 


dMfe 


430  MANUAL    OF    CHEMISTRY 

number"  of  a  fat  or  oil  is  the  quantity  of  iodiu  which  100  grama 
of  the  substance  can  take  up  under  the  conditions  of  the  process, 
and  is  an  important  factor  for  its  identification. 

Elaidic  Acid  —  C17H33.OOOH  —  is  an  isomere  of  oleic  acid,  pro- 
duced from  it  by  the  action  of  nitrous  acid.  It  is  a  crystalline  solid, 
fusible  at  51°  (123.8°  F.).  Its  formation  is  utilized  to  distinguish 
non-drying  from  drying  oils  (p.  366).  The  former,  containing  oleic 
acid,  solidify  when  acted  on  by  nitrous  acid;  the  latter,  containing 
linoleic  acid,  do  not. 

RicinoleicAcid— CH3.(CH2)5.CHOH.CH2.CH:CH.(CH2)7.COOH 
—  is  an  unsaturated  oxyacid,  which  exists  as  its  glyceric  ester  in 
castor  oil. 

Linoleic  Acid  —  C17H31.COOH  —  is  an  unsaturated,  pure  acid, 
containing  two  atoms  of  hydrogen  less  than  oleic  acid.  It  exists 
as  its  glyceric  ester  in  the  drying  oils,  which  dry  and  solidify  on 
exposure  to  air. 

Propargylic  Acid — Propiolic  Acid  —  CH-C.COOH — correspond- 
ing to  propargylic  alcohol,  is  an  example  of  an  acetylene  monocar* 
boxylic  acid.  It  is  a  liquid,  having  the  odor  of  acetic  acid.  Sorbic 
acid,  CH3.CH:CH.CH:CH.C00H,  is  a  diolefin  monocarboxylic  acid, 
derived  from  parasorbic  acid,  whi(»h  is  an  unsaturated  oxyolefin  acid 
occurring  in  the  berries  of  the  mountain  ash. 

Olefin  dicarboxylic  Acids.  —  The  acids  of  this  series  contain  two 
atoms  of  hydrogen  less  than  the  corresponding  acids  of  the  oxalic 
series,  and  they  consequently  bear  the  same  relation  to  those  acids 
that  the  acids  of  the  oleic  series  bear  to  those  of  the  acetic  series. 

Esters  of  three  acids  having  the  composition  C2H2(COOH)2  are 
known.     The  free  acid  corresponding  to  one  of   these,   methylene 

malonic  ester,  CH2:C\^qqq(q^H5)'  ^^  ^^^^   known.     The  other  two, 
fumaric    and    malei'c    acids,    are    "  space    isomerids  "    ( p.     314) . 
Fumaric  acid  is  considered  to  have  the  axial  symmetric  structure: 
H.C.COOH 

II  ,  because  it  does  not  yield  an  anhvdrid,  and  because,  on 

HOOC.C.H 

oxidation,  it  yields  racemic  acid,  while  maleic acid  has  the  plane  sym- 
metrical structure,  because,  owing  to  the  closer  proximity  of  the  car- 

H.C.COOH  H.C.COv 

boxyls,      II  ,  it  readily  forms  an  anhydrid,       II       /O,  and  be- 

H.C.COOH  H.C.CO^ 

cause  on  oxidation  it  yields  inactive,  or  meso-tartaric  acid  (see  p. 

313  and  Fig. 40,  ibid.). 

Fumaric  acid  exists  free  in  many  plants,  notably  in  Iceland  moss. 

Fumaric  and  maleu^  acids  are  readily  converted  one  into  the  other  by 

simple  heating,  and  the  two  are  produced  together  by  the  action  of 


i 


UNSATURATED   ALIPHATIC   COMPOUNDS  431 

heat  upon  malic  acid  (p.  344),  or  by  boiling  solutions  of  monobromo- 
saccinic  acid  (p.  337). 

Famaric  acid  crystallizes  in  small  prisms,  almost  insoluble  in 
cold  water,  which  sublime  at  200*^  (392*^  F.).  Maleic  acid  fuses  at 
130*"  (266*"  F.),  and  boils  at  160°  (320°  F.).  Both  fumaric  and 
maleic  acids  are  converted  into  succinic  acid  by  nascent  hydrogen. 

Five  unsaturated,  open  chain  acids  are  known  having  the  formula 
C3H4(COOH)2,  the  next  superior  homologues  of  fumaric  and  maleic 
acids.  One  of  these,  ethidene  malonic  acid,  is  only  known  in  its  es- 
ters CH3.CH:C<^coo[c2h1)-  The  structural  formulae  of  the  others  are: 

H.C.COOH  H.C.COOH  CH2:C.C00H  CHj.COOH 

II  II  I  I 

COOH.CCCHa)  (CH3)C.C00H  CH-.COOH  CH 

CH.COOH 

MMAConie  aeid  Citraeonio  aeid  Itaeonlc  acid  OlnUconie  aeid. 

(Methyl-fomaric).  (Methyl-malele).  (Methylene  tneeinic). 

Mesaconic  acid  is  formed  by  heating  citraconic  or  itaconic  acid 
with  water  at  200°  (392°  F.).  It  is  difficultly  soluble  in  water,  and 
fuses  at   202°   (395.6°  F.).     Citraconic  acid   is  obtained  from  its 

H.C.COv 
anhydrid,         II      /O,  formed  in  the  distillation  of  citric  acid,  by 

beating  with  water.  Easily  soluble  in  water,  f.  p.  80°  (176°  F.). 
Itaconic  acid  is  similarly  obtained  from  its  anhydrid,  a  product  of 
distillation  of  aconitic  acid,  f .  p.  161°  (320.2°  F. ) .  Glutaconic  acid  is 
formed  by  the  action   of  barium   hydroxid  upon  coumalic  acid,  an 

a-pyrone  monocarboxylic  acid  (p.  517):    OC\cH.Qg^C.COOH.     It 

fuses  at  132°  (269.6°  F.). 

Aconitic  Acid— C00H.CH2.C(C00H) : CH.COOH— is  an  olefin 
tricarboxylic  acid.  It  exists  as  its  Ca  salt  in  a  number  of  plants, 
including  aconitum,  equisetum,  sugar-cane  and  beet-root.  It  is 
formed  by  heating  citric  acid  (p.  346),  either  alone  or  with  HCl  or 
H2SO4.  It  is  also  obtained  synthetically  from  a  mixture  of  acetic 
and  oxalic  esters.  It  forms  crystalline  plates  or  prisms,  soluble  in 
water,  alcohol,  and  ether,  fuses  at  191°  (375.8°  F.).  Heat  decom- 
poses it  into  itaconic  acid  and  CO2.  Nascent  hydrogen  reduces  it  to 
tricarballylic  acid  (p.  338). 

Allyl  Oxid— A%/tc  f><Af»—(CH2:CH.CH2)20— is  an  example  of 
the  unsaturated  ethers.  It  exists  in  small  quantity  in  crude  essence 
of  garlic,  and  is  formed  by  the  action  of  allyl  iodid  upon  sodium- 
allyl  oxid.  It  is  a  colorless  liquid,  having  the  odor  of  garlic,  insol- 
uble in  water,  boiling  at  82°  (179.6°  F.).  Mixed  ethers  are  also 
known,  such  as  propargyl  ethyl  ether,  CH:  C.CH2.O.CH2.CH3. 


432 


MANUAL     OF    CHEMISTRY 


UNSATURATED   SULFUR    AND   NITROQEN   COMPOUNDS. 

Allyl  Sulfi(i-^(CH2:CH.CH2)2S — corresponding  to  the  oxid,  is  the 

priocipal  constituent  of  volatile  oil  of  garlic^  obtained  by  distilling 
garlic  with  water.  It  is  formed  by  the  action  of  alcoholic  solution  of 
potassium  snlfid  npon  ally!  iodid*  It  is  a  colorless  oil,  lighter  than 
water,  soluble  in  alcohol  and  in  ether,  boils  at  140°  (280°  F.), 

Ally!  Isothiocyanate— J/ff5^(/r^  c?f/— S:C:X,CH2.CH:CH2— is  the 
chief  constituent  of  volatile  oil  of  mustard,  and  of  radish  oil.  It  is 
prepared  artificially  by  distilling  allyl  broniid  or  iodid  with  potat^sium 
or  silver  thiocyaoate:  SrCiN.Ag+CHal.CH^CH^^SiCiN.CHs.CH:* 
CHs+AgL  It  does  not  exist  preformed  in  the  mustard  seeds,  but  is 
prodnced  by  the  decomposition  of  a  glocosid,  potassium  myronate 
(p.  467),  in  the  presence  of  water  under  the  influence  of  an  enzym, 
also  contained  in  the  seeds,  called  myrosin.  The  action  takes  phu-e 
at  O""  (32''  FJ,  but  not  at  temperatures  above  40""  (104°  F,).  Tlio 
activity  of  myrosin  is  also  impaired  by  the  presence  of  acetic  acid 
(vinegar).  The  pungent,  rubefacient  and  vesicant  actions  of  mns- 
tard  are  due  to  mustard  oil. 

Pure  allyl  isothiocyanate  is  a  colorless  oil»  sp.  gr.,  1.015  at  20° 
(68°  FJ,  boils  at  150°  {302°  F.),  has  a  penetrating,  pungent  odor, 
sparingly  soluble  in  water »  very  soluble  in  alcohol  and  in  ether.  Ex- 
posed to  air  it  gradnally  turns  brownish -yellow^  and  deposits  a  resi* 
noid  material.  Heated  with  HCI  or  with  H2O,  it  is  decomposed  into 
carbon  dioxid,  hydrogen  sulMand  allyl^amin:  S:C:N.CH.i.CH:CH2+ 
2H20=C02+SH2+NH2.CH2.CH:CH2. 

Allyl -amin  is  the  superior  homologue  of  vinyi-amin,  which  is 
capable  of  uniting  with  sulfur  dioxid  and  water  to  produce  taurin  or 
amido-isethionic   acid   (p.  421)  ;    NH2.CHiCH2+S02+H30=NHt,. 


n 


CLOSED    CHAIN    COMPOUNTJS 


433 


I 

I 


CLOSED  CHAIN  COJrPOlTNDS— CYCLIC  COMPOUNBS. 

These  compounds,  which  include  many  importaut  natural  products, 

and  a  practically   unlimited  number   of  synthetic  compounds,  differ 

from  the  members  of   the  open  chain  series  in  that   they  contain  a 

^ronp  of  more  than  two  atoms  united  together  by  exchange  of  va* 

lences  in  such  a  manner  as   to  form  a  closed  chain,  or  ring,  or 

nucleus.     If  all  the  atoms  so  united  are  carbon  atoms  the  Bubstauce 

belongs  to  the  carbocyclic  class;   if  an  element  other  tlian  carbon 

enters  into  the  formation  of  the  ring  the  substance  is  heterocyclic. 

Some  closed  chain  compounds  are  produced   by  the  interaction 

of  two  open  chain  compounds,  as  in  the  formation  of  certain  diamins 

(p.  385)  and  compound  ureas  (p.  406).    Others,  such  as  the  lactids 

(p,  368),  lactones  (pp,  368,  412),  and  lactams  {p.  413),  are  produced 

by  internal  reaction  in  an  open  chain   molecule*     But  the  principal 

method  of  formation  of  closed  chain  compounds  is  by  polymerizMtion. 

lu  some  cases  this  takes  place  at  comparatively  low  temperatures,  hh 

in  the  formation  of  trioxymethylene  from  formaldehyde  (p,  ^iOl),  and 

of  the  polymeric  thioaldehydi's  and  their  snlfones  (p,  373). 

Among  the  instances  of  formation  of  cyclic  from  acyclic  com- 
fminds  there  is  one  of  polymerization  at  a  high  temperature  which  is 
f^t  special    interest  as   bearing  upon  the  constitution  of  the  cyclic 
<?f^mpounds.      The  central  figure  of    the  carbocyclic    compounds  is 
benzene,  CeHe,  which  is  obtained  principally  from  gas* tar.     Coal  gas 
<^Qtains  acetylene,  C2H2,  and  it  is  easy  to  conceive  that  one  or  two 
<*f    the  bonds   uniting  the   two  carbon  atoms  in  acetylene  may  be 
Joasened  under  the  influence  of  heat,  and  that  a  molecule  of  benzene 
^8iy  be  produced  by  fusion  of  three  molecules  of  acetylene  :   3C2H3= 
^VBe.    The  product  so  obtained  is  neither  dipropargyl,  HCfC.CHs.- 
CH2,C:CH,  nor  dimetliyl  diaeetylene,  H3C.C  •  C.C  :  C.CHa  (p.  273), 
but  another  substance,  the  nature  of  whose  substituted  derivatives 
iuditates  that  the  six  hydrogen  atoms  are  of  equal  value,  and  there- 
fore similarly  attached  to  carbon  atoms;  and,  there  being  three  bisub- 
stituted  derivatives  {p.  436),  to  at  least  three  different  carbon  atoms, 
Tbeae  conditions  can  only  be  fulfilled  by  a  cyclic  structure  of  the 
molecule  of  benzene  and  its  derivatives  (p. 435).     Pyridin  also,  which 
Jjas  a  prominence  among  the  heterocyclic  compounds  corresponding 
ta  that  of  benzene  among  the  carbocyclic,  has  been  obtained  from 
acetylene  and  hydrocyanic  acid  by  a  fusion  very  similar  to  that  by 
which  acetylene  alone  forms  benzene  :  2C2H2+HCN=CfiH5N.     It  is 
alao  formed  by  the  action  of  heat  upon  substances  containing  nitro- 
gen as  well  as  carbon  (p.  517) 
2« 


434 


MANUAL    OF    CHEMISTRY 


CAKBOCYCLIC    COMPOUNDS. 

Carbocyclic  compouods  are  known  containiog  from  three  to  seven 
carbon  atoms  in  a  ring.  Compounds  are  also  known  containing  a 
mueh  larger  nnraber  of  carbon  atoms,  but  these  are  formed  by  fusion 
or  union  of  two  or  more  rings  of  six  carbon  atoms  or  less,  or  by  the 
attachment  of  an  open  chain  grouping  tipon  a  closed  chain  one 
(p.  439).  The  hexacarbocyclic  compounds  are  far  more  numeron» 
and  important  than  the  others. 

The   mononnelear  carbocyelic    hydrocarbons   have  algebraic  for- 
mulae varying  from  C^Hsi,  to  Ci,H2*_«,  and  are  isomeric  with  the  un-  ^ 
saturated  open  chain  hydrocarbons   (p.  273),     Those  of  the  series*^| 
C#.H2«  are  known  as  polymethylencs,  being  considered  as  formed  by 
the  union  of  a  number  of  methylene  groups*  CH2.     Thus  hexahydro- 

<CH    CH*  \. 
Ch'  CH2  /CJH2.     But  the  chemical 

relations  of  the  polymethylenes  to  the  saturated  hydrocarbons  is 
closer  than  that  to  their  isomeres,  the  olefins,  because,  containing  iiD 
double  linkages,  they  cannot  be  modified  by  addition  without  disrup- 
tion of  the  ring.  So  long  as  the  cyclic  formation  is  maintained,  the 
polymethylenes  are  saturated  compounds,  as  are  the  paraffins.  For 
this  reason  their  "Geneva"  names  are  the  same  as  those  of  the  paraf- 
fins of  like  carbon  content,  to  which  is  prefixed  the  syllable  *'cyclo,** 
and  they  are  known  generically  as  cycloparaffins ;  or  the  symVjol  R 
is  used  in  place  of  the  syllable  "eyclo."  The  hydrocarbons  of  the 
series  C«H2«-2,  isomeric  with  the  acetylenes  and  diolefln,*,  are  referable 
to  the  latter,  not  to  the  former,  as  tbey  cannot  contain  a  triple  link- 
age in  the  ring.  But,  containing  only  one  double  linkage,  tbey  are 
more  closely  related  to  the  olefins.  Therefore  tetrahydrobenzcne, 
CH^CH^XhO^^-^  isomeric  with  hexadiene,  CH2:CH.CH2.CH2.CH:- 
CH2,  containing  but  one  double  linkage,  is  cyclo-hexene,  or  R» 
hexene,  Similarly  dihydro benzene,  CHx^^^jj^'^h'^CH,  is  a  cyclo- 
diolefin :  R-hexadiene  j  and  benzene  a  cyclotriolefin  :  R-hexatrienc. 
The  cycloparaffins  are  formed  by  the  action  of  sodium  upon  the 

dibromoparaflins.     Thus  trimethylene  is  obtained  from  trimethvlene 

/Clh 
broraid:  CH2Br.CH2.CH2Br+Na2=Cn2     I     +2NaBr. 

Tri',  tetra-, penta-,  and  hepta-carbocyclic  hydrocarbons,  and  their 

numerous  derivatives,  uotubly  acids  and  ketones,  are  known.  Tbey 
are  m>t  as  yet,  however,  of  medical  interest,  except  that  certain 
tetra-,  and  pt-uta-i-uinpounds  are  among  the  decomposition  products 
of  certain  alkaloids* 


HEXACAEBOCYCLIC    COMPOUNDS 


435 


HEXAOAEBOdYCLIO    COMPOUNDS  —  AROMAllC 
SUBSTANCES. 

These  compoands,  which  are  very  numerous  and  important,  all 
contain  a  group  of  six  carbon  atoms,  to  which  are  attached  six,  eight » 
ten  or  twelve  univalents,  or  their  equivalent.  As  the  simplest  repre- 
sentative of  the  class  is  benzene,  CeHe,  and  as  all  of  these  bodies  may 
be  derived  from  benzene,  directly  or  indirectly,  and  yield  that  hydro- 
carbon on  decomposition,  the  aromatic  substances  may  be  considered 
as  derivatives  of  benzene.  This  being  the  case,  the  constitution  of 
benzene  itself  is  of  great  importance,  and  has  been  the  subject  of 
much  study.  Several  schematic  representations  of  the  structure 
of  the  benzene  molecule  have  been  suggested,  the  most  demonstrative 
of  which  are  the  hexagonal  form  of  Kekul6,  the  prismatic  form  of 
Ladenburg,  and  the  diagonal  form  of  Clans: 


H 

I 
C 

^\ 
H— C         C— H 


H— C         C— H 

\/ 
C 

I 
H 

Hexagonal. 


y 


H 

i 


H— C 


H— C 


\ 


\ 


C-H 


\ 
C-H 


Pritmatie. 


C 

I 
H 

Diagonal. 


In  the  hexagonal  formula  the  carbon  atoms  exchange  one  and  two 
valences  alternately,  each  being  attached  to  two  others;  in  the  pris- 
matic  form  each  carbon  atom  is  attached  to  three  others  by  single 
valences;  and  in  the  diagonal  form  the  hexagon  is  retained,  but,  in 
place  of  double  linkages,  a  central  linkage  between  all  the  carbon 
atoms  is  substituted.  All  of  these  formulas  represent  the  equivalence 
of  the  carbon  atoms,  and  the  constitution  of  isomeres  equally  well 
(see  below).  The  prismatic  formula  cannot  be  modified  to  represent 
a  constitution  of  the  additive  derivatives  of  benzene,  such  as  dihydro- 

beozene,  CH^ch!ct '^CH,  and  tetrahydrobenzene,CH^CH!cHl /CH2. 

Neither  the  prismatic  nor  the  diagonal  formula  admits  double  linkages 
between  carbon  atoms  in  the  ring.  That  these  exist  is  shown,  how- 
ever, by  the  formation  of  the  additive  products  mentioned,  by  the 
formation  of  anhydrids  from  ortho- derivatives  only  (see  below),  and 
by  certain  physical  properties.     Moreover,  the  hexagonal  formula  ac- 


436 


MANUAL    OF     CHEMISTBY 


cords  well  with  tlie  tetrahedral  representation  of  tlie  valences  of  the 
carbon  atom  (p,  312),  the  six  tetrahedra  being  alternately  united  by 
edges  and  apexes  in  benzene,  and  bj^  apexes  in  hexabydrobeuzene. 
For  these  (and  other)  reasons,  chemists  have  very  generally  adopted 
the  hexagonal  expression,  although  it  still  leaves  soraething  to  be 
desired.  The  figure  of  a  hexagon  is  nsed  in  chemical  writings  to  rep- 
resent the  benzene  ring.  If  used  alone  it  represents  a  moleenle  of 
benzene,  CeHc;  and  to  represent  the  prodnetsof  snbstitntion  the  sym- 
bols of  the  substituted  group  are  written  in  the  proper  position, 
thus  : 

COOH 


Beuusne^ 


Beiuoic  fteid. 


Phlhailc  ftuUydrtd. 


Isomery  of  Benzeoc  Substitution  Products. — (1)  The  six  atoms 

of  hydrofjfn  in  benzene  are  of  equal  value.  There  exists  but  one 
mono -substituted  derivative  of  benzene  containing  any  given  univa- 
lent; one  chlorobenzene,  CeHsCl,  one  nitro-benzene,  C«H5(N02),  one 
amido -benzene,  CeH5(NH2),  one  benzoic  acid,  CiiHf,.COOH,  etc. 
Therefore,  benzene  is  symmetrical  in  strncture,  and  its  hydrogen 
atoms  equal  eaeh  other  in  value,  as  do  those  of  methane,  while  those 
of  pyridiu  (p,  509)  are  not  all  of  like  value, 

2.  Any  hydrogen  aloni  selerted  (n  the  benzene  ring  is  symmetrically 
placed  in  rfftrfnee  to  two  pairs  of  hgdrogen  atomH,  and  to  the  Rtxth 
hydrogen  atom  individnallg.  With  all  di-,  tri-,  and  tetra- substituted 
derivatives  oi  benzene,  containing  like  substituted  univalents,  there 
are  three  isonieres.  Three  diehloro-,  three  triehloro*,  and  three 
tetrachloro- benzenes,  etc,  and  in  no  instance  are  more  than  three 
known.  There  is  but  one  explanation  of  the  facts  mentioned  above, 
namely,  that  the  different  bi-,  tri-,  and  tetra -derivatives  are  pro- 
duced by  differences  iu  the  relative  positions  of  the  substituted 
groups,  by  differences  in  "  orientation/'  as  among  the  aliphatic  com- 
pounds, the  several  oxyacids  are  "*  place  isomeres"  of  each  other 
(p.  339). 

The  hexagonal  formula  of  benzene  is  very  convenient  for 
showing  the  structure  of  the  several  isomeres.  For  this 
purpose  the  carbon  atoms  are  numbered,  beginning,  for 
convenience,  at  the  top  and  proeeeding  clockwise* 

It  has  been  demonstrated  that  in  some  of  the  bisubsti- 
tuted  derivatives  the  two  substituted  groups  are  attached 
to  adjacent  carbon  atoms,  i*  e,^  to  1-2,  2-3,  3-4,  4-5,  5-6,  or  6-1, 


HEXACABBOCYCLIC    COMPOUNDS 


437 


Clearly  for  each  carbon  atom  there  is  a  pair  of  adjacent  positions,  as 
1-2  and  1-6,  2*1  and  2-3,  etc*,  which  are  equivalent  to  each  other.* 
In  other  bisubstituted  derivatives  it  may  be  shown  that  the  twcf 
substituted  groups  are  attached  to  carbon  atoms,  separated  from  each 
other  by  one  carbon  atom  on  one  side  and  by  three  on  the  other,  an 
arrangement  which  renders  the  hexagon  unsymmetricaL  Such  posi- 
tions ai*e  1-3,  2-4,  3-5,  4-6,  5-1,  and  (i-2.  Or,  for  each  carbon  atom 
there  is  a  pair  of  equivalent  unsymmetrical  positions,  as  1-3  and  1*5, 
etc.  There  remains  but  one  other  arrangement  possibk%  the  sym- 
metrical, or  diagonal,  1-4,  2-5,  3-6.  With  the  tri-  and  tetra-substi- 
tated  derivatives  there  are  also  three  possible  arrangements:  the  adja- 
cent, vicinal,  or  consecutive,  as  1-2-3,  2-3-4;  1-2-3-4,  or  2-3-4-5; 
the  unsymmetrical,  as  1-2-4,  3-4-6;  1-2-3-5,  or  3-4-5-1;  and  the 
symmetrical,  as  1-3-5,  2-4-6;  1-2-4-5,  or  3-4-6-1.  Compounds  in 
which  the  substitution  is  adjacent  are  desiguated  as  ortho-com- 
pounds (  V^'^^='straight),  or,  in  writings  by  the  abbreviation  o-,  or 
by  the  figures  1-2,  etc,  Thus  C<jH4(OIi)2ii,3>,  o-diphetiol.  Unsym- 
metrical compounds  are  designated  as  meta-compounds  (/^^I'^-after), 
or,  abbi-eviated,  m-,  or  by  the  figures,  l-3»  etc.:  e.  g.,  CaHa- 
{Br)3u-*-4?,  ni'tribromobenzene.  8y mujetrical  compounds  are  desig- 
nated as  para-compounds  (^apa- beside),  abbreviated  p-,  or  l-4»  etc.: 
c.  g.,  C6H2(NH2)iii*»^-5>,  p-tetraamido- benzene.  Or»  to  illustrate  by 
the  formuhe  of  the  di-  and  tetra-chloi'o benzenes  : 


ri 


a 


Symuiiitric«), 


*KoTS. — Th«  pHneilMil  objection  to  th«  hexAKODA]  formnU  of  bentetie  (mnd  stated  bj  KftkalA 
\\ti  ti  tbftt  ihtMt  two  po«iUoD«  Are  not  entirely  «qiiivjileiit,  at  In  the  position  I-S  th^p  i^roapini 

C— C— ,  whU*  In  10  It  In — C— C— .  md  that  conaequenily  there  should  be  two  ortho  deriv»tiTei» 
wlifle  but  one  is  known.  The  student  iM  referred  to  more  extended  works  for  m  di»eu«4ion  of  tliU 
«obJ«rt. 


\ 


438 


MANUAL    OF    CHEMISTRY 


In  the  bisnbstituted  derivatives  it  is  immaterial  whether  the  twf>  • 
substituted  groups  are  of  the  same  kind  or  different.     But  when,  ici 
a  trisubstituted  derivative,  the  substituted  groups  are  not  the  same 
in  kind,  the  number  of  possible  isomeres  is  increased.     Thus  there 
are  six  possible  chloro-dibromobenzenes  ( formulae  1  to  6  below),  o^ 
which  two  (1  and  2)  are  derived  from  orthodibromobenzene,G8H4£rfti.»> 
three  (3,  4,  and  5)  from  metadibromobenzene,  C8H4:Br2(i.3).  and  on^ 
(6)  from  paradibromobenzene,  C6H4:Br2(r.4).    The  number  of  possible 
trisubstituted  derivatives  is  increased  to  ten  when  all  three  substituted 
groups  are  of  different  kind. 


(NO,) 


CI 

1 

2 

3 

Orthodibromo* 

Orthodibromo- 

Metadibromo* 

metachloro. 

parachloro. 

orthochloro. 

Bp       CI 


OH 


(NO2) 


CI 

Br 

4 

Metadibromo- 

parachloro. 

5 
Metadibromo- 
allometachloro. 

6 

Paradibromo- 
metachloro. 

Ill  naming  these  derivatives,  the  characterizing  group  of  the 
T)arent  substance  is  given  the  position  1  in  the  hexagon,  the  prefix 
"ortho"  is  applied  to  the  name  of  the  group  occupying  one  of  the 
ortho  positions  2  and  6,  "meta"  to  that  occupying  one  of  the  meta 
positions  3  and  5,  and  "para"  to  that  occupying  the  para  position  4. 
Thus  the  substance  having  the  formula  7  above  is  orthonitro-meta- 
bromo-phenol.  But  another  substance  is  known,  not  identical  with 
this,  having  the  formula  8  above,  in  which  the  nitro  group  occupies 
the  second  ortho  position,  6.  To  distinguish  substances  such  as 
these,  the  designation  "allortho"  is  given  to  the  position  6,  and  the 
designation  "allometa"  to  the  position  5.  Thus  the  substance  having 
the  fonnula  8  is  metabromo-allorthonitro-phenol.  When  formulae 
are  used  the  numerals  corresponding  to  the  position  of  substitution, 
enclosed  in  brackets,  are  placed  after  the  symbols.  Thus  7  is  writ- 
ten: C6H3(OH)(N02)[.i  Br[3i,  and  8:  C«H:,(OH)Bn,i  (N02)r6i. 


HEXACARBOCYCLIC    COMPOUNDS  439 

Classification  of  Aromatic  Substances. — The  benzene  deriva- 
tives may  be  classified  into  five  classes  : 

A.  Componnds  containing  a  single  benzene  nnclens,  unmodified 
except  by  substitution  for  hydrogen.  Monobenzenic  compounds.  In- 
cludes benzene  aud  its  homologues,  and  the  phenols,  alcohols,  acids, 
etc.,  derived  from  them. 

B.  Compounds  containiug  a  single  benzene  nucleus  in  which  one 
(or  more)  of  the  double  bonds  has  been  converted  into  a  single  one, 
thus  adding  two,  four,  or  six  valences  to  the  carbon  ring.  Monohy- 
drobenzenic  compounds.  Includes  the  cyclohexadienes,  cyclohexenes, 
and  cyclohexanes  (p.  434),  and  their  derivatives,  among  which  are 
the  t^rpenes  and  camphors. 

C.  Compounds  containing  two  (or  more)  benzene  nuclei,  or  ben- 
zene and  pentacarbocyclic  rings,  fused  together,  and  having  two  car- 
bon atoms  in  common.  Includes  indene,  fluorene,  naphthalene,  an- 
thracene, and  phenanthrene  and  their  derivatives.  Compounds  with 
condensed  nuclei. 

D.  Compounds  containing  two  (or  more)  benzene  rings,  directly 
united  by  loss  of  two  H  atoms.     Diphenyl  and  its  derivatives. 

E.  Compounds  containing  two  (or  more)  benzene  nuclei,  united 
by  aliphatic  groups.     Includes  di-  and  polyphenyl  paraffins,  olefins 

and  acetylenes  and  their  derivatives. 

The  following  formulae  will  serve  to  indicate  the  diflPerences  in 
constitution  of  the  several  classes : 

CH,  Ha  H        H 


I 

c  c 


i  i 


»-C  C— H  H2C  CH2  H— C  C         C— OH 

I  li  II  I  II  I  . 

,ia-C  C— H  H2C  CHa  H— C         C  C-H 

\  /  \  /  %/  \  ^ 

c  c  c      c 

I  "  i  Jr 

H  Ha  H         H 

(A)  (B)  (C) 

Hfthyl  benzeiM.  Hexahydrobenzene.  jS  Naphthol. 

HH     HH  HH         HH 

I   I      I   I  II  II 

c=c     C=C  C=C        c=C 

^ij.C      C.C      C.(NHa)   H-C      C-C-C      C— H 
%        ^      \        ^  %         ^      B2    \         ^ 

C— C     C-C  C— C         C-C 

I   I      I   I  II         II 

HHHH  HH         HH 

(D)  (E) 

pt^DUmido-diphenyL  Diphenyl-metbaiM. 


440 


MANUAL    OF    CHEMISTRY 


A.    MONOBENZENIC  COMPOUNDS. 

HYDROCARBONS. 

Benzene  —  Benzol  —  C^Hfi — (not  to  be  confounded  with  benzine^ 
a  mixture  of  hydrocarbons  of  the  series  CitHw+,,  obtained  from 
petroleum^— p.  276)  does  not  exist  in  nature.  It  is  obtained,  pure, 
by  deeoni posing  benzoic  acid  by  heating  with  slaked  lime:  CeHs,- 
COOH+CaHL>Oj  =  CaC03+CoH6+n20.  It  is  produced  in  the 
distillation  of  eoal,  and  exists  in  coat  tar,  from  which  it  is  obtained 
for  use  in  the  arts. 

Coal  tar,  or  gas  tar,  is  a  very  complex  mixture,  containing  forty 
or  fifty  substances  — hydrocarbons,  phenols  and  bases  —  and  is  the 
crude  material  from  which  many  important  substances  are  obtained, 
lu  working  it,  it  is  first  distilled,  four  fractions  being  colleet^sd; 
(1)  Light  oil  distilling  below  IdO"^  (302°  P,)r  (2)  mrbatic  oil,  or 
mtddie  oH,  distilling  below  230°  (446°  P\).  Contains  phenols  and 
naphthalene*  (3)  Betivif  oil,  or  cnttsote  oil,  distilling  below  270^ 
(518*^  F.),  Furnishes  naphthalene,  (4)  Oreen  oil,  or  anthracene  0f7, 
distilling  above  270°.  Contains  anthracene  and  other  solid  hydro- 
carbons.  Tlie  residue  in  the  still  h  pitch.  The  light  oil  con tn ins 
lienzene,  tohnnje  and  xylene,  with  some  thiophene,  phenols,  pyridin, 
and  heavy  oils.  It  is  further  purified  to  yield  vniious  grades  of 
cominercijd  ''benzol,''  the  best  of  which  contains  about  70  per  cent. 
of  benzetic.  and  24  per  cent,  of  toluene,  with  some  xylene,  euraene 
and  thiophene. 

Pure  benzene  is  a  colorless  liquid,  having  an  ethereal  odor,  crjs- 
tallizing  at  5.4^  (41.7°  F.),  boiling  at  80.5''  (17G.9°  PJ,  sp.  gr.  0.86 
at  15°  (59°  FJ,  immiscible  with  water,  mixing  with  alcohol  and 
ether.  It  dissolves  I,  S,  P^  resins,  cnoutehoue,  guttapercha,  fats  and 
many  alkaloids.     It  is  inflammable,  and  burns  with  a  smoky  fiame. 

Benzene  unites  directly  mih  CI  or  Br  to  form  products  of  addition 
or  of  substitution.  Free  CI  acts  only  slowly  upon  benzene  alone,  but 
the  action  is  much  accelerated  by  the  presence  of  certain  chlorids. 
particularly  FeaCltj.  The  corresponding  I  derivatives  can  only  be 
obtained  indirectly,  Sulfuric  acid  combines  with  it  to  form  benzene 
sulfonic  acid,  CgHs.BOsH.  Nitric  acid  converts  it  into  nitro-benzene, 
CffH^.NO^t  or,  if  fuming  HNO3  is  used  and  the  mixture  hoi  Jed,  into 
a  mixture  of  the  three  diuitro-benzenes,  CaH4(N02)2.  It  is  reduced 
to  hcxahydrobenzene  by  hydr iodic  acid. 

Homologues  of  Benzene.^  These  may  be  considered  as  alky!- 
beuzeues,  formed  by  the  substitution  of  alkyl  groups  for  an  equivalf^nt 
number  of  hydrogen  atoms  in  benzene.     The  usual  general  melhud 


\ 


MONOBENZENIC    COMPOUNDS 


441 


of  thfiT  formation  indicates  the  constitution:  they  are  ohtainofl  by 
treating  a  niixture  of  bromobenzene,  ether,  and  flie  bromid  or  iodid 
of  the  corresponding  alcoholic  radical  with  godiora.  Thus  mono- 
bromo' benzene  and  methyl  bromid  yield  methyl -benzene,  or  toluene: 
Cett^Br  +  CH:,Br  +  Naj  =  2XaBr  +  CoH^.CH.f  They  are  also  formed 
by  the  action  of  the  alkyl  chlorids  upon  the  inferior  honiolognes  in 
presence  of  AlijClu,  or  of  ZuCbi  or  Fe2Cl<i.  Thus  benzene  and  methyl 
cMorid  form  toluene:  CoH5  +  CHuCl  =  CoHs-CHa  +  HCL  This  is  a 
general  method  frequently  used  for  the  introduction  of  alicyls  into 
aromatic  compouuds,  and  probably  depends  upon  the  formation  of 
intermediate  organo- metallic  compciuuds  (p.  375).  There  are  numer- 
ous other  methods  for  their  production.  The  superior  homologues 
of  benzene  include  many  isumercs.     Thus  there  are: 


l-CrHi,  i.e.,  CflH&(CHj)-Metliyl -benzene, 

4-C#Hio,  i.e.,  three  C^H^ICH  3)2-0-,  m-^  and  p- Dim  ethyl -benzenes, 

C«H5(  CsHft  I'Ethy  1  *  benzene, 
8-CtHi2>  i.  e.,  three  CnH3(CH:i)3-o-i  tn-,  and  p-Triniethyl*beDzeneBt 

three  CftH4(CH3)tCjHr,)-o-,  m-,  and  p- Methyl -ethyl  beDzeneB, 
CflHst  CaH?  )-Propy  1  -  bi^-nzene, 
CflE.-,(  C;(Hr )- 1  Bopropy!- benzene, 
l&-^ioHu,  i,e,,  three  C,iH.:{CFI;i)4  o^  m-.  and  p-Tetramethyt  benzenes, 
three  CoHv(C2H(i)t-o-|  m  ,  and  p -Diethyl -benzenes, 
three  CdH:i(CH:i)2  (C^Hft)-©-,  m-,  and  p  Diraethylethyl- benzene b, 
three  CflH4(CH:i){CaH7)-o-,  m-,  and  p-Mftbylpropyi-benzenes^ 
three  CtH^fCHj )(C:iH7)-'C>-, tu-, and p-Metbyliaopropyl- benzenes, 
four  CiiHfi(C4Hft)-Butyl- benzenes. 

The  homolognes  of  benzene  ai-i*  acted  upon  by  reagents  in  the 
game  manner  as  benzene  itself.  In  addition »  the  lateral  chain  may  be 
acted  upon.  Benzene  is  not  acted  npon  notably  by  oxidizing  agents 
ttnless  they  be  sufficiently  powerful  to  disrupt  the  molecule^  But 
oxidants  such  as  dilute  nitric  acid,  or  the  chromic  niixture,  oxidize 
the  lateral  chain  in  the  homologues  of  benzene*  with  formation  of 
carboxylic  acids.  Thus  methyl -benzene,  CctHs.CHa,  yields  benzoic 
acid.  CsTIvCOOH. 

Tolnenc — Toluol  ^Methyl-bcnzenc  —  CoHs.CHa — exists  in  the 
products  of  distillation  of  coal,  wood,  etc.»  and  is  a  constituent  of 
commeiMjial  benzene.  It  is  formed  synthetically  by  the  general  meth* 
ods  given  above;  or  may  be  obtained  pure  by  decomposition  of  one  of 
the  toluic  acids  by  lime. 

It  is  a  colorless  liqnid,  boils  at  110,3°  (230.5°  PJ,  does  not  BO- 
lidify  at  —20''  (—4°  P.),  sp.  gr.  0.872  at  15°  (59°  FJ,  does  not  mix 
with  water*  but  mixes  with  alcohol,  ether  and  carbon  bisnifid. 

Xylenes — Xylols — C^Hio. — Fonr  isomeres  ai-e  possible  and  are 
jLOOwa:  ethyl-benzene,  C0H5.C2H5 — and  ortho-  (1 — 2),  meta-  (1^ — 3), 


442  MANUAL   OF    CH£MISTBY 

and  para-  (1 — 4),  dimethyl-benzenes,  C6H4(CH3)2.  Ethylbenzene  is 
a  colorless  oil,  b.  p.  134°,  obtained  by  fractional  distillation  of  ani- 
mal oil.  The  tbree  dimethyl  benzenes  exist  in  coal  tar  and  in  the 
commercial  xylene,  b.  p.  139°,  70  9fc  consisting  of  metaxylene,  and 
paraxylene  being  present  in  very  small  amount.  Mesitylene,  formed 
by  distilling  acetone  or  allylene  with  H2SO4,  is  p-trimethylbenzene. 
Cymene,  a  liquid  having  a  pleasant  odor,  present  in  several  ethereal 
oils,  is  p-methylisopropyl- benzene.  It  is  formed  by  the  action  of 
methyl  iodid  upon  p-bromo  isopropyl- benzene  in  presence  of  Na. 

MONOBENZENIC    HYDROCARBONS    WITH    UNSATURATED    LATERAL 

CHAINS. 

These  are  similar  in  constitution  to  the  homolognes  of  benzene, 
except  that  the  lateral  chains  are  olefins  or  acetylenes,  in  place  of 
paraffins. 

Styrolene  —  Cinnamene  —  Bthylenebenzene  —  Phenylethene  — 
C6H5.CH:CH2 — exists  ready  formed  in  essential  oil  of  styrax.  It  is 
also  formed  by  decomposition  of  cinnamic  acid  (p.  457),  or,  syn- 
thetically, by  the  action  of  a  red  heat  upon  pure  acetylene,  a  mixture 
of  acetylene  and  benzene,  or  a  mixture  of  benzene  and  ethylene.  It 
is  a  colorless  liquid,  has  a  penetrating  odor,  recalling  those  of  ben- 
zene and  naphthalene,  and  a  peppery  taste;  boils  at  143°  (289.4°  F.) ; 
soluble  in  all  proportions  in  alcohol  and  water ;  neutral  in  reaction. 

Phenyl-acetylene — Acetenyl  -  benzene  —  CeHs. C  *:  CH — is  formed 
by  heating  aeetophenone  chlorid  with  KHO  in  alcoholic  solution.  It 
is  a  colorless  liquid,  of  an  aromatic  odor,  boils  at  140°  (284°  F.). 

HALOID    DERIVATIVES. 

By  the  substitution  of  atoms  of  CI,  Br  and  I  for  the  hydrogen  of 
the  principal  and  lateral  chains  in  benzene  and  its  superior  homo- 
lognes, a  great  number  of  subtances  are  obtained,  many  of  them 
forming  isomeric  groups. 

The  chlorobenzenes  are:  Monochlorobenzene :  CeHsCl,  liquid,  b. 
p.  132°,  sp.  gr.  at  0°-1.128°;  obtained  by  the  action  of  CI  upon 
CeHe  in  the  cold,  in  presence  of  a  little  I.  Orthodichlorobenzene : 
C6H4Cl2(i..),  liquid,  b.  p.  ITQ"",  sp.  gr.  1.328  at  0°;  obtained  by  the 
action  of  CI  upon  CoHe.  Metadichlorobenzene :  C6H4Cl2(i.3),  liquid, 
b.  p.  172°,  sp.  gr.  1.307  at  0°;  obtained  indirectly.  Paradichloro- 
benzene:  C6H4Cl2(w)»  crystalline,  f.  p.  56.4,°  b.  p.  170°,  is  the  prin- 
cipal product  of  the  action  of  CI  on  CeHe  in  presence  of  I.  Metatri* 
chlorobenzene :  CeH3Cla(,.c..4)»  crystals,  f.  p.  17°,  b.  p.  213°.  Paratri- 
chlorobenzene :    CoHaCUd-ss;,    crystals,    f.    p.    (j3.4°,    b.    p.    208°. 


PHENOLS 


443 


Mctatetrachlorobenzene :  CfiH2CUui.-i5),  crystals,  f.  p.  50°,  b.  p.  246 

Paratctrachlorobenzene;  C(jH:;UUa-»-*5i,  crystals,  f.  p.  l'J7°,  b.  p.  245 

Benzyl  chlorid — C6lIr.CH2CI — is  an  example  of  the  siibstitutum 
of  a  halogen  in  the  lateral  chain  of  a  superior  honiologue  of  benzene. 
It  is  obtained  1>y  the  action  uf  ehlorio  upon  boiling  tolut-ne;  or  nf 
PCI50U  beuzylic  alcohoL  It  is  a  colorless  liquid^  boils  at  176°  (348.8'^ 
P.),  and  «rives  off  pnngent  vapors  wbi«h  excite  the  lachrymal  secre- 
tion. It  is  readily  oxidized  to  benzoic  aldehyde  or  benzoic  ur'u],  and 
serves  for  the  introdn<*tio«  of  the  radical  benzyl  into  other  niolecnies. 
The  radical  of  benzylic  alcohol  (CoH.^.CH-),  (p.  452)  is  called  benzyl; 
that  of  benzoic  aeidi  (CflHr,.CO),  benzoyl  (p.  456)*  The  prronpj* 
C'eHs,  called  phenyl  and  CeHi,  called  phenylen,  behave  as  rndicals, 
corresponding  to  the  alkyls  (p*  274)  and  alky  lens  (p.  294)  respectively, 

BENZENIC  OXYGEN    COMPOUNDS. 

derivatives  of  benzene  containing  oxygen  include,  bedsides 
alcohols,  aldehydes,  ketones,  acids,  ethers,  and  anhydrids,  c-or- 
responding  to  those  of  the  open  chain  series,  a  class  of  hydroxids, 
the  phenols,  of  which  there  are  no  aliphatic  prototypes. 


PHENOLa 

In  the  phenols  the  hydroxy  1  is  substituted  for  the  hydrogen  of  the 
benzene  ring,  while  in  the  alcohols  the  substitution  occurs  in  a  lateral 
chatti.  Thus  phenol  is  CoHs.OH;  beuzylic  alcohol,  CfiHs.CH^OH. 
All  six  of  the  hydrogen  atoms  of  benzene  may  be  thus  replaced  to 
form  monohydric  phenols,  dihydric  phenols,  etc. 

In  their  properties  the  phenols  differ  from  the  alcohols  by  more 
nearly  approaching  the  character  of  the  acids.  On  oxidation  they  do 
not  furnish  aldehydes  or  acids;  they  do  not  divide  into  water  and 
hydrocarbon  under  the  influence  of  dehydrating  agents  ;  they  do  not 
react  with  acids  to  form  esters;  they  combine  directly  with  CI  and  Br 
to  form  products  of  substitution;  they  form  witli  the  metallic  elementj§ 
eonsponnds  more  stable  than  similar  compounds  of  the  true  alcohols, 

The  tertiary  aliphatif'  alcohols  are  those  which  most  closely  resem- 
ble the  phenols.    They  both  contain  the  group  C.OH,  triply  linked  to 

other  carbon  atoms;  (ji^q^j^^C.OH,  and  Zhc/^-*^^-  ^^"^^  **^^y  **1^^ 
n.-iiemble  each  other  in  that  each  is  only  slowly  and  imperfectly  esteri- 
fied  when  heated  to  150*^  with  acetic  acid.  But,  while  the  tertiary 
alcohols  are  readily  attacked  by  phosphorus  pentachlorid,  with  forma* 
lion  of  alkyl  chlorids:  {Clh)%  \  C.OH+PCU^(CIIj)a  l  C.Cl  +  POCMa 
-fHCl;  that  reagent  displaces  the  hydroxyl  of  the  phenols  only  im- 


MANUAL    OP    CHEMISTRY 


are 


perfectly,  or  not  at  all.    The  products  of  the  reaction  with  phenol  are 
either  phenyl  phosphoric  tetrachlorid:   C6H5.0H+PCU=C6H5,OPC' 
+  HC1;   or  a  mixture  of  monochlorobenzeue  with  either  diphenyl  ph 
phoric  acid:   4Cen5.0n+PCl5=2C«H5Cl  +  P04H(CJl5)2 +  3HC1,  or 
triphenyl  phosphate:  4C0Hfi.OH+PCU=C«H5CI+PO4{C6H5)3+4Ha 
Tlte  [atter  alone  is  produced  by  the  action  of  phosphorus  oxychiori 
on  phenol:   3C6H:>,OH  +  POCl3=P04(CeH5):«+3nCL 

The  phenols  occur  in  nature  in  small  quantities  only;   some  in  the 
vegetable  world,  and  some  iu  combination  as  ester  sulfuric  acids  ii 
the  urine.     They  are  mostly  products  of  distillation  of  wood,  co«l^ 
etc- 

MONOATOMIC — MONOHYDEIC  PHENOLS, 

The  monoatomic  phenols  are  produced:  (1)  by  fusing:  the  cot- 
responding  sulfonic  aeids  with  caustic  alkali  :  CsHs.SOaK+KHO^ 
CflHs^OH+K-iSOa',  (2)  by  decomposition  of  the  diazo- compounds  (p* 
481)  by  boiling  with  water:  C6H5.N:N.HS04+H20=C6H5.0H+N5+ 
H2SO4;  (3)  the  higher  phenols  are  produced  by  heating  phenol  with 
ZnCls  and  the  alcohols,  a  phenolic  ether  being  also  formed.  Thus 
phenol  and  methylic  alcohol  yield  cresol  and  methyl-phenyl  ether: 
2C6H5.0H+2H.CH20H=CgHi.OH.CH3+C6H5.0.CH3+2H20. 

The  phenols  are  reduced  to  hydrocarbons  by  heating  with  ziii'* 
dust.  Their  ring-hydrogen  is  readily  replaceable  by  other  elemental 
or  groups  to  form  haloid,  nitro,  amido  derivatives,  etc.  Their  hy- 
droxy! hydrogen  is  also  readily  replaceable  by  alkyls  to  produce 
ethers,  by  Na,  K,  and  Ca  to  produce  phenates,  and  by  acidyls  to  pro^ 
duce  phenyl  esters  (p.  446).  The  phenols  combine  with  the  dia» 
compounds  to  produce  azo*  and  diazo  dyes,  and  with  phthalic  acid 
to  produce  phthalenis. 

Phenol — Bcnzophenol — Phenyl  kydroxid — Phefiic  acid — Carbolic 
acid — CfiHs.OH^ — exists  in  considerable  quantity  in  coal-  and  wood- 
tar,  and  in  small  quantity  in  castoreura  and,  in  combination,  in  the 
urine.     It  is  produced  in  the  intestine. 

It  is  formed  :  (1)  by  fusing  sodium-phenyl  sulfid  with  excess  lafl 
alkali  :  CoHs.NaS+NaHO^CeHs.OH+NasS;  (2)  by  heating  phen  ™ 
iodtd  and  potassium  hydroxid  at  320°  (608"*  FJ:  CeiH5l+KH0= 
CeHs.OH+KI;  (3)  by  heating  together  salicylic  acid  and  quicklime; 
CoH4  0H.COOH+CaH202=CeHr.OII  +  CaC03+H20;  (4)  by  totiil 
synthesis  from  acetylene^  through  benzene  (p.  433),  and  its  sulfonic 
acid;  (5)  by  decomposition  of  the  phenylic  esters  by  alkalies.  Thus 
salol  yields  phenol  and  salicylic  acid:  CflH4,OH.C06(C6Hi)+KHO= 
CflH5.0H+C6H4.0H.COOK  ;  (6)  by  dry  distillation  of  benzoin. 
"Synthetic  phenol,"  prepared  by  method  {4},  is  now  manufactured. 
"Carbolic  acid"  is  obtained  from  the  "middle  oil"  of  gas  tar  (p.  440) 


iGi4^ 


PHENOLS 


445 


It  is  purified  by  conversion  into  potassium  pbenate,  Cells^OK,  which 
is  rrystallized,  decomposed  by  HCl,  and  the  liberated  phenol  recrys- 
tallized  and  distilled. 

Phenol  is  extensively  used,  not  only  as  an  antiseptic,  hut  also  in 
the  inannfactnre  of  numerous  derivatives,  including  medicinal  com- 
pounds, dyes  and  explosives. 

Phenol  crystallizes  in  long,  colorless  needles,  fuses  at  43"^  {109.4** 
P.),  boils  at  183^  (361.4°  FJ,  sp.  gr.  1.084  at  0^  (32°  Fj,  has  a 
characteristic  odor,  and  an  acrid,  burning  taste,  soluble  in  15  parts 
of  water  at  20^  (68°  FJ,  very  soluble  in  alcohol  and  in  ether,  neutral 
in  reaction.     It  may  be  distilled  wirhotit  decomposition. 

Its  vapor  is  reduced  to  benzene  by  heating  with  Zn,  It  combines 
with  H28O4  to  form  <>-,  and  p*phenol  sulfonic  acids.  With  HNO3  it 
forras  2-4-6-trinitropheno!,  Heated  with  sulfuric  and  oxalic  or 
arsenic  acid,  it  yiekis  severa!  triphenyl- methane  dyes,  among  which 
are  corallin,  rosolic  acid,  peoniu,  azulin,  aurin,  and  pheniein. 

Analytical  Characters — (1)  Its  pecnliarodor.     (2)   Mix  with  one 
qnarter  volume  of  NHiHO:   add  two  drops  of  sodium  hypochlorite 
solution,  and  warm:  a  blue  ur  i,n"eeu  color.     Add  IICl  to  acid   reac- 
tion: turns  red.     (3)  Add  two  drops  of  the  liquid  to  a  little  HCl, 
and  then  a  drop  of  HNO3;  a  purple  red  color.     (4)   Boil  with  HNO3 
&o  long  as  red  fumes  are  given  off,  neutralize  with   KHO:  a  yellow, 
€5ry8talline  precipitate,    (0)  Heat  with  Mil  Ion's  reagent:  a  yellow  ppt., 
forming  a  red  solution  iu  HNO3,    (6)  With  solution  of  FeSU4:  a  lilac 
cooler.     (7)  Add  excess  of  bromin  water:  a  yellowish -white  preeipi- 
t^*te.     This  compound,  tribromophenol,  CnH-BruOIT,.  is  the  form  in 
"^^""hich  phenol  is  quantitatively  determiued;   100  parts  of  it  correspond 
I   t>o  29.8  parts  of  phenol.     (8)  Moisten  a  pine  shaving  with  the  liquid, 
frl^en  with  HCl,  to  which  a  trace  of  KClO.i  has  been  added  immedi- 
«^t;^ly  before  use,  and  expose  to  sunlight :  a  fine  blue  color.     The  test 
»^honld  be  tried  also  with  a  solution  of  phenol,  and  with  the  acid 
«^l^ne,  as  only  certain  varieties  of  pine  are  suitable.     (Pine-shaving 
^■^^s^^f'tion .     See  also  Pyrrole.) 

Toxicology.— Carbolic  acid  is  an  active  poison  and  corrosive*  It 
."*is  caused  death  in  a  dose  of  1.5  gram.  The  average  duration  of 
f  »%tiftl  ea^es  is  2-8  hours.  Death  may  occur  in  3^5  minutes  from  col- 
l^!ip.  It  causes  a  burning  sensation,  soon  followed  by  intense  pain 
Hid  cauterization  of  all  parts  with  which  it  comes  in  contact.  The 
r^f:»i  11^  which  it  produces  is  at  first  white,  after  a  few  minutes;  later  it 
I  ■^^'^•iiji  ^]^i,*|jp^  j^nj^  when  the  eschar  separates,  a  brown  stain  remains, 
_^^^Htcli  persists  for  many  days.  Vomiting  usually  occurs,  the  vomited 
^^^i^tters,  as  well  as  the  breath,  having  the  odor  of  carbolic  acid.  The 
^^^tient  soon  becomes  unconscious,  and  death  is  from  collapse  or  in 
^"^iia.     The  urine,  normal  in  color  when  first  voided,  soon  beeonies 


MANUAL    OP    CHEMISTRY 


olive -green,  brown,  or  eveu  black  in  color.  The  treatment  consists 
in  admmistration  of  albumen,  saccbanited  lime,  sodium  sulfate,  or 
strong  alcohol,  followed  by  lavage. 

Phenates. — Carholates, — Tbe  hydroxyl  hydrogen  of  phenol  is  re- 
placeable by  certain  metals  and  by  alkyls  to  form  phenatcs  and 
phenyl  ethers.  When  phenol  atid  KHO  are  heated  together,  potas- 
sium phenate,  CeiHsOK,  is  formed.  This,  when  treated  in  alcoiioUc 
solntion  with  HgCl2,  produces  merciiric  phenate,  (C6H50)2Hg,  a 
yellow,  crystalline  solid  which  has  been  nsed  in  medicine. 

Phenol  Esters. — The  H  of  the  OH  of  phcntd  is  replaceable  by 
either  a  iky  Is  or  acidyls.  With  the  former  phenol  plays  the  part  of  an 
acid,  and  therefore  the  resulting  compounds  are  the  phenol  esters, 
C(»rresponding  to  t!jc  metallic  phenates.  But,  although  plienol  is  not 
an  alcohol,  the  radical  plienyl  (CaHs)'  of  which  it  is  the  hydroxid,  is 
in  all  respects  equivalent  to  the  alkyls,  of  which  the  monohydric  alco* 
hois  are  the  hydroxids.  Therefore  the  phenol  esters,  such  as  CsHs.O,- 
CH3,  are  also  the  phenyl  ethers  (p.  464),  The  phenyl  esters,  on  the 
other  hand,  may  be  considered  as  derivable  from  plieuol  by  substitu- 
tion of  acidyls  for  hydroxyl  hydrogen:  CrH^.O.  (OCCHa) ,  or  as 
derivable  from  the  acids  by  snbstitution  of  phenyl  for  carboxyl  hydro- 
gcTJi  CH3.COO(CgHr,).  The  phenyl  esters  are  formed  by  the  action 
of  the  acidy!  rhlorids  npon  the  phenols,  or  upon  their  metallic  deriva- 
tives: CflH5.OH+CHa.0OCl=CH3,CO2.CflH5  +  HCl,  or,  C6H5.OK  + 
CH;i.COCl=Cri;i.CO.C6H5+KCl,  as  the  aliplmtii'  esters  are  formed 
by  the  action  of  acidyl  halids  upon  the  alcohols  or  npon  the  aleohol- 
ates  {p.  359), 

Cresols— Cresylols — Cresylic  acids — Benzylic  or  cresylic  phe* 
nols— CgH^x  015' — 108,— Of  the  three  possible  componnds,  two,  the 
para  and  ortlio,  accompany  phenol  in  coal-tar,  from  which  they  may 
be  separated  by  fractional  distillation.  They  are  more  readily  oh* 
tained  pure  from  toluene.  Creolin — an  antiseptic  less  x>oisonous  thaD 
phenolt  consists  chiefly  of  cresols,  Lysol  is  impure  paracresol,  mixed 
with  fat  and  saponified. 

Creasote  —  Creasotum  (U.  S.)  —  is  a  complex  mixture  containing 
phenol,  cresol,  creasol,  CgHiuO^,  guaiacol,  C7H8O2  (see  pyrocateehol), 
and  other  substances,  obtained  from  wood -tar,  and  formerly  extensively 
used  as  an  antiseptic*  It  is  an  oily  liquid,  colorless  when  freshly 
prepared,  but  becoming  brownish  on  exposure  to  lifrht.  It  has  a  hum* 
iug  taste  and  a  strong,  peculiar  odor.  It  boils  at  203*^  {♦197.4'^  FJ, 
and  does  not  solidify  at  —27^  (— 16.G°F.). 

Xenots — Xylenols. — Theoretically  there  are  six  possible  xenols 
Tvhiclj  ai*e  dimethyl  phenols*  CuTIaCCHaj^OH  ,  two  derivable  from 
orthoxylene,  three  from  metaxylene  and  one  from  paraxylene.     They 


PHENOLS 


447 


bave  all  b^en  produced  synthetically.  There  are  also  three  possible 
ateiioU  which  are  ethyl  phenoISt  C.6H4(C2H5)OH. 

Thymol^ — 3-Methyl'6^isopropyl  phenol  — €ymylic  phenol —  CVH3- 
(OH)ii>(CIia)(jj(C3H7)c«j, — exists,  aticompaiiyiiig  cymene  and  thymene, 
CioHifl,  in  esseoee  of  thyme,  from  whieh  it  is  obtained,  It  is  also 
prepared  synthetically  from  cuminic  aldehyde,  C(iH4(CHO)fi)(C3H7)(4}. 

It  crystallizes  iti  large,  transparent,  rhombohedral  tables;  hns  a 
peppery  tastCi  and  an  agreeable,  aromatic  odor.  It  fuses  at  44^  (111.2° 
P.),  and  boils  at  230°  (446^  F.);  is  sparingly  soluble  in  water,  very 
soluble  in  alcohol  and  etlier.  With  the  alkalies  it  forms  definite  eom- 
pouDds,  which  are  very  soluble  in  water.  Its  reactions  are  very  sim- 
ilar to  those  of  phenoL 

Thymol  is  an  excellent  deodorizing  and  antiseptic  agent,  possess- 
ing the  advantage  over  phenol  of  having  itself  a  pleasant  odor, 

Aristol  is  diiodo-thyraol,  a  dibenzenic  rorapound,  produced  by  the 
action  of  a  solution  of  I  in  KI  upon  an  aqueous  solutinn  of  thymol  in 
the  presence  of  KHO,  It  is  an  inodurons,  yelluwish-red  powder, 
insoluble  in  H2O,  very  sparingly  soluble  in  alcohol,  readily  soluble  in 
ether  and  in  chloroform.  It  is  decomposed  by  heat  and  by  light  and 
\b  said  to  be  a  non* poisonous  antiseptic, 

Carvacrol—2-M ethyl  -  5-isopropyl  phenol  —  CeHa ( OH ) (., (CH^}^.)- 
(CaH7)(5> — an  isomere  of  thymol,  exists  in  many  essential  oi!s,  and  is 
obtained  by  the  aclion  of  lodin  upon  camphor;  by  tlie  action  of  pot- 
ash in  fusion  upon  cymene  sulfonic  acid.  CioHiitSOjH;  or  by  a 
transposition  of  the  atoms  of  another  isomere,  carvel,  which  exists  in 
caraway  oU.  It  is  an  oil,  boiling  at  233'"-235''  (451.4'^-455"  FJ. 
Heated  with  P2O&,  it  yields  orthocresoL 


SUBSTITUTED    PHENOLS. 

Phenol  is  a  inonosnbstituted  derivative,  and  hence  still  contains 
five  H  atoms  which  may  be  replaced  by  other  elements  or  radicals^  to 
produce  di-  or  tri*  or  poly -substituted  derivatives  of  benzene,  which 
will  be  ortho.  meta  or  para,  etc.,  according  to  the  relations  of  the 
introduced  groups  to  the  OH,  already  existing  in  pbenoli  or  to  the 
C^2m-¥\  and  OH  groups  in  its  superior  homologues. 

Chlorophenols. — The  three  mouoehlorinated  componnds  nre  ob- 
tainable from  the  corresponding  chloranilins.  Orthochlorophenol 
(1—2)  is  a  colorless  liquid,  boils  at  175^^-176''  (347''-348.8^  F,), 
converted  into  pyrocatechol  by  KHO.  Mctachlorophenol  (1—3)  is  a 
liquid,  boiling  at  214°  (417,2*^  FJ,  KHO  converts  it  into  resorcinol, 
Parachlorophenol  (1 — 4)  is  a  crystalline  solid,  fusible  at  37°  (98.6^ 
FJ ,  converted  into  quinol  by  fusion  with  KHO.  Di-,  tri-,  and 
penta-chlorophenols  are  also  known. 


448 


MANUAL    OF    CHEMISTRY 


Bromophcnols  correspond  io  method  of  formation  and  properties 
^vith  the  CI  derivatives.  2-4-6  Tribromophenol — CflH2.OH.Br3 — is 
the  precipitate  formed  ou  adding  bromin  water  to  phenol  solution.  It 
forms  white  cryatals,  fusing  at  92°  (197.6°  FJ,  insoluble  in  water, 
25oluHIe  in  alcohol  and  ether.  It  is  used  as  an  antiseptic  in  diphtheria 
noder  the  name  BromoL  Paramouochlorophenol  and  orthomono- 
hroinoplienol  have  been  used  for  the  same  purpose. 

lodophenols  are  formed  b^^  the  action  of  iodiu  and  K2S  upon 
phenol  in  the  presence  of  excess  of  alkali,  or  from  the  correspond! nfr 
amidophenols.  Like  the  chlorin  and  hromiii  derivatives,  they  yield 
the  corresponding  diphenol  by  the  actkm  of  KlIO  in  fusion.  A  tri* 
iodophenol,  formed  by  the  action  of  solution  of  I  in  KS  upon  an 
alkaline  solution  of  phenol,  has  been  proposed  as  a  substitute  for 
iodoform  under  the  name  annidalin.     (See  also  pp.  459»  464,  472,) 

DIATOMIC,    OR    DIHYDRIG    PHENOLS. 

Diatomic  phenols  are  derived  from  the  benzenic  hydrocarbons  by 
the  substitution  of  two  (OH)  e:ronps  for  two  atoms  of  hydrogen. 
In  obedience  to  the  laws  of  substitution  already  discussed,  three 
such  compounds  exist,  corresporuliug  to  each  hydrocarbon, 

P  yro  c  atecho  I — Pif  roea  t  fc  hi  a — ihtfp  km  i  r  tt  cid —  Ort  h  od  ioxy  -htn  zeti  e 
— CbH4(OH)2(i.3>  is  obtained  from  catechin  or  from  raorintannie  acid 
by  dry  distillation;  also  by  the  action  of  KHO  on  orthochlor-  or 
orthoiodo-plicnol,  or  by  decomposing  its  methyl  ether,  guaiacol,  by  HI 
at  200"^  (392'^  F.).  It  crystallizes  in  short,  square  prisms;  fuses  at 
104''  (219. 2'^  F.),  and  boils  at  243.5''  (473.9"  FJ.  Readily  soluble 
in  water,  alcohol,  and  ether.  Its  aqueous  solution  gives  a  dark  green 
eolor  with  Pe^Cle  solution,  changing  to  violel  on  addition  of  NH4HO, 
NaHCOg,  f>r  tartaric  acid.     Its  acid  sulfuric  ester  exists  in  the  urine. 

Monomethyl  -  pyrocatechuic  Ether  —  Guaiacol — t*<sH«,OH,- 
(OCII:i)r„— exists  in  beech -wood  tar,  from  which  an  impure  (6CK90%) 
guaiacol  is  obtained  as  a  yellowish  liquid,  sp.  gr.  1.133,  boiling  at 
206'^-'207°,  by  distillation.  Pure  gnaiacol  is  obtained  from  this  by 
i*rysta!lization  at  low  temperature;  by  heating  pyrocateehol  with  potas- 
sium-methyl  sulfate  and  KHO;  also  from  vanillin  (p.  454),  and  from 
veratrol.  It  is  a  crystalline  solid,  fuses  at  SS""  (91.4°  F.),  boils  at  205** 
(401^^  F.},  soluble  in  50  parts  of  water.  Guaiacol  is  used  in  the  treat- 
ment of  phthisis  both  on  account  of  its  germicidal  action,  and  upon  the 
theory  that  it  forms  compounds  with  the  toxalbumins  (q,  v. )»  which 
are  readily  eliminated.  It  is  also  used  in  numerous  forms  of  combi* 
nation  :  in  its  carbonic  esters,  as  styracol^cinnamyl-gnaiacol,  as 
benzosol"bcnzoyl- guaiacol,  as  thiocol=guaiacol -potassium  salfoQ> 
ate,  and  in  combination  with  salicylic  acid. 


I 


PHENOLS 


449 


I 


* 


Dimethyl-pyrocatechuic  Ether  — Vcratrol  —  CqUa ( OCHj) ^^.a,  —  is 
an  oil,  crystallizing  at  15"^  (59*^  PJ»  fonni^d  by  distillitig  veratrie 
acid  (p,  460),  or  by  acting  upon  the  potassium  salt  of  guaiaeol  with 
methyl  iodid. 

Resorcinal  —  E^sorcin  — Metadioxtj -bemene — C0H4(OH)9,,.3j  is  ob- 
tained by  the  action  of  fus^^d  KHO  on  raetachlor-  or  iodopbeuol. 
It  is  also  prepared  by  dry  distillation  of  extract  of  Brazil  wood. 

It  forms  short»  thick,  colorless  and  odorless,  rhombi^i  prisms. 
Fuses  at  104°  {219.2°  FJ,  and  boils  at  271°  (510.8°  F.).  It  is  very 
soluble  in  water*  alcohol,  and  ether.  Its  aqueous  solution  is  iieutnU 
in  reaction,  and  intensely  sweet.  With  FejCU  its  solutions  assume  a 
dark -violet  color,  which  is  discharged  by  XHiIIO.  Its  amtnonineai 
solntiou,  by  exposure  to  air,  avssumes  a  pink  »'olt>r,  changing  to  bn*wn 
and,  on  evaporation,  green  and  dark  blue.  Heated  with  phthalic 
anbydrid  at  195*"  {383°  PJ  it  yields  fluorescein  (p.  451).  It  dis- 
solves in  fuming  n-S04,  forming  an  orange -red  solution,  which  bo- 
comes  darker,  changes  to  greenish -black,  then  to  pure  blue,  and 
finally  to  purple  on  being  warmed. 

Resorcinol,  heated  witli  sodinni  nitrite  and  H^O  to  about  150° 
(302^  F.)  yields  a  blue  pigment  known  an  lacmoid,  whicli  behavcB 
like  litmus  with  aeids  and  alkalies,  but  is  more  sensitive. 

Quinol  —  ITffdroqu  fnone  —  Paradionj  -  hfnzeu  e  —  CaH4  { 0  H )  s  u.  4)  in 
formed  by  fusing  paraiodo-pljen*il  with  KHO  at  180°  (356°  F.), 
by  dry  distillation  of  oxysalieylie  aeid  or  of  quintc  acid^  and  by  tho 
action  of  reducing  agents  on^'qninone  It  forms  colorless,  rhombic 
prisftls,  whieh  fuse  at  160°  {336.2'^  F.).  Rcinlity  soluble  in  watei\ 
alcrohol.  or  ether.  Its  aqueous  sola  t  ion  is  turned  red -brown  by  NII4- 
HO.     Oxidizing  agents  convert  it  into  quinoue. 

OTsinol—Orsin—DimefaflifiXfj  to!ftetie—Ctili'A(VB'A),,, ( OH ) „. { OH )  „ 
— a  homologneof  reson-inol,  exists  in  nature  in  those  lichens  which  are 
used  as  sources  of  arehil  and  litmus  {Rocvlhi  tiHcforla,  etc.).  It  crys- 
tallizes in  six-sided  prisms;  is  sweet;  readily  stdable  in  water,  alco- 
hoK  or  ether;  fuses  at  G8°  (136.4'^  F.),  Its  aqueous  solution  is  col- 
ored violet-blue  by  Fe^Cl^.  It  unites  with  NH.f  to  ft»rni  a  compound 
which  absorbs  O  from  the  air,  and  is  converted  into  orcein,  C;!!;- 
XO3;  a  dark-red  or  purple  body,  which  is  the  chief  constituent  of  the 
dye-stuff  known  as  archil,  cudbear,  French  purple,  and  litmus. 


TRUTOMIC,    OH    TRIHYDRIC    PHENOLS. 

Phloroglucin  —  €fiH3(OH)3,i,3,5>'^is  obtained  by  the  action  of 
potash  upon  phloretin,  quereitrin,  maelurin,  cntechin,  kino,  etc*  It 
CTT^tallizes  in  rhombic  prisms,  eonlaining  2x\q;  is  very  sweet;  and 
very  Jioluble  in  water,  alcohol,  and  ether. 


450 


MANUAL    OF    CHEMISTRY 


PyTOgBllol—PijrogalUe  acid — CtiHi(OR)^^l.:,.^) — is  formed 
gallie  acid  (p.  461)  is  heated   to  200^  (392"  F.).     It  crystallizesTir 
white    needles-    neutral    in    reaction  ;    very    sohible   in  water;  very, 
bitter;  fnses  at  132''  (238°  FJ;  boils  at  210''  (410°  FJi  poisonous. 
Its  most  valuable  property  is  that  of  absorbing  oxygen,  for  whieli"J 
purpose   it  is  used  in  the  laboratory  in  the  form  of  a  solution  of 
potassium  pyrogallnte. 

When  pyrogallol  is  heated  with  half  its  weight  of  phthalic  an-^ 
hydriti  for  several  hours  at  190''-200°  (374'*-392'' F.)  it  yields  pyro- 
gallol  phthalein,  or  gallein,  a  brown -red  powder  (or  green  crystals) 
which  dissoh^es  with  a  brown  color  in  neutral  solutions,   the  color  j 
changing  to  red  with  a  faint  exeess  of  alkali, 

Oxyhydroquinone"C6H3(OH)3<M.4)— is  produced  by  fusing  qni- 
none  with  KHO.      It  is  crystalline,  fuses  at  140°  (284°  F,),  very, 
soluble  in  water  and  in  ether. 


UNSATtTRATED    PHENOLS. 

These  are  derived  from  the  benzenic  hydrocarbons  with  unsatu- 
rated lateral  chains  (p.  442)*  Olefiu  monoxybenzeues,  dioxyheu- 
zeneSf  trioxybenzenes,  and  a  tetroxy benzene  are  known.  They  ar 
aromatic  oils  of  high  boiling  points,  many  derived  from  variou»| 
plants.  Included  in  this  class  are:  Chavlcol,  p-Allyl  phenol — CeHi- 
OH,{CH2*CH:UHa)<4> — occurs  in  an  oil  from  certain  peppers,  Ita 
isomere,  p-Propenyl  phenol,  C6H4.0H.{CH:CH.CH3)ui»  is  p-anol, 
whose  methylie  ether,  C«H4.0(Cn3).(CH:CH,CH3),4>,  p-propcnyl 
antsol^  or  anethol,  exists  in  the  oils  of  anise,  estragon  and  fenneL 
Among  the  diphenols  is  cugenol,  C6H3.(CH2.CH:CH2)li)(OCH3)<3>- 
(OH)u,,  allyl  3-4-guaidcol,  an  essential  oil  from  piraeuta,  eugenia, 
and  certain  peppers.  The  corresponding  dimethyl  compound  exists 
in  bay-oil.     Safrol,  Allyl  3-4  pyrocatechol  methylene  ether,  CHa:^ 

CH.CH2\       y^—O/     *•  is  present  in  oil  of  sassafras,  and   oil 

illicinm.     Apiol,  from  oil  of  parsley,  is  a  complex  methylene  ether» 
corresponding  to  allyl  tetraoxybenzene,  CeH,(OH)4.CH3.CH:CH3. 


PHENOL    DYES. 


Aurin*^CiflHi403i  and  Rosolic  acid— C2oHi603^ — are  substances  ex- 
isting in  the  dye  obtained  by  the  action  of  oxalic  acid  upon  phenol  in 
presence  of  H2SO4,  known  as  corallin,  or  poconin,  which  coninanni- 

cates  to  silk  or  wool  a  fine  yellow -red  color, 

Aurin  crystallizes  in  fine,  red  needles  from  its  solution   in   HC^l. 


QUIN0NE8 


451 


I 

I 


It  is  insoluble  in  H2O,  but  soluble  in  HCl,  alcohol,  and  glacial  acetic 
acid.     It  forms  a  colorless  compound  with  potassium  bisnllite. 

Pbthalcins.— Tliese  substances  are  produced  by  heating  the  phe- 
nols with  phihalic  anhydrid,  C(jH4(CO)20,  water  being  at  the  sum© 
time  eliminated. 

Their  constitution  is  that  of  a  benzene  nucleus,  two  of  whose  H 
atoms  have  been  replaced  by  two  acetone  groups  (CO),  whose  remain- 
ing valences  attach  them  to  two  phenol  groups  by  exchange  with  an 
atom  of  hydrogen    (see  p.  504), 

Thus  phenol-phthalem,  the  simplest  of  the  group,  has  the  con- 

Btitution,  CtjH4(^Q0__(3*fj;J^(OH)!  Phenol -phthalein  is  a  yellow,  crys- 
talliue  powder,  insoluble  in  water,  but  soluble  in  alcohoL  Its  alco- 
holic solution,  perfectly  colorless  if  neutral,  assumes  a  brilliant  ma- 
genta-red in  the  presence  of  an  alkali.  This  property  renders 
phenol -phthalein  very  valuable  as  an  indicator  of  reaction, 

Resorcinoi-phthalem  —  Fluorescein  —  CaoHioOs  —  bears  the  same 
relation  to  resoreiuol  that  phenol- phthalein  does  to  phenol,  and  is 
obtained  from  resorcinol  by  a  corresponding  method.  It  is  a  dark- 
brown  crystalline  powder*  which  dissolves  in  ammonia  to  form  a  red 
Bolution,  exhibiting  a  most  brilliant  green  fluorescence*  A  tetra- 
bronjo-derivative  of   fluorescein   is  used   as  a  dye  under  the  name 


» 


QUINONES. 

The  quinones  are  benzene  derivatives  in  which  two  atoms  of 
kj'drogen  are  replaced  by  two  oxygen  atoms.  The  attachment  of 
the -0,0-  group  is  either  ortho-  or  para-,  never  raeta-.  Ortho- 
quinones  of  the  polybenzenie  series,  such  as  P  naphthoquinone  and 
anthraquinone  (p.  499),  are  well-known  corapounds,  but  the  mono- 
beozenic  ortho  -  quinones  are  only  known  in  their  derivatives. 

The  monobenzenic  para-qui nones  may  be  considered  either  as 
peroxids,  the  bonds  of  the  benzene  ring  remaining  intact  (Formula  I), 

or  they  may  be  considered  as  ring- 
ketones  (Formula  II),  in  which 
the  two  CO  groups  form  a  part  of 
an  oxidized  hydroaroraatic  ring 
(p,  486),  The  former  view  is  fa- 
vored by  the  facts  that  the  qui- 
nones are  strong  oxidizing  agents, 
as  are  the  peroxids  in  general, 
and  that  they  yield  monosubsti- 
tuted  derivatives  by  replacemt*nt 
of  their  oxygen  by  univalents,  as  benzoquinone  forms  p-dioxybeu' 


O 

/\ 

HC         CH 

II  II 

HC         CH 

\/ 

C 

It 

0 

(ID. 


452 


MANUAL    OF    CHEMISTBY. 


^/CH:CHV 


zene,  (H0)C^qh"q|j^C(0I1)  oq  rediietioii»  and  prndiclilorobenzeiie, 
ClC^CH.CH^CCl,  by  the  action  of  PCI5.     On  tJie  other  hand,  the 

existence  of  the  C0=  group  in  the  quinones  is  indicated  by  the 
fact  that  they  readily  form  oxims  with  hydroxy  lam  in,  a  reaction 
characteristic  of  compounds  containing   00^   (p.   299),  as  benzo- 

quiQone  forms  quinone  dioxim,  HO  XCs^qjj'^^jj^CN.OH;  and  if,  by 

reason  of  its  oxidation  of  phenylhj'drazin,  benzoqninone  forms  no 
pheuylhydrazone  (p.  485)  such  compounds  are  formed  by  the  naph- 
thoquinones. 

The  quinones  form  a  number  of  derivatives,  by  the  introduction 
of  alkyl,  halogen,  amido*,  nitro,  etc.»  groups  for  their  hydrogen  or 
oxygen.  Among  these  are  the  anils,  formed  by  sabstitntion  of 
=N.CeH5  for  0,  from  which,  in  turn,  an  important  series  of  blue 
and  green  dyes,  the  indoanilin  or  indulin  dyes  are  derived, 

Quinone  —  Benzoquinone  —  C6H4:\   I— is  formed  by  the  action 


\ 


o 


of  oxidants  upon  a  v«triety  of  p-benzeoe  derivatives,  but  best  by 
limited  oxidation  of  quinic  acid.  It  crystallizes  in  golden-yellow 
prisms,  f.  p.  116°  (240.8^  FJ,  sublimes  at  ordinary  temperatures, 
sparingly  sohible  in  cokl  water,  readily  soluble  in  hut  water,  alcohol 
and  ether.  It  has  a  peculiar,  pungent  odor,  stimulates  the  lachrymal 
secretion,  and  irritates  the  skin.  Reducing  agents  convert  it  into 
quLuoL 

AR05L4TIC    ALCOHOLS. 

The  alcohols  (p.  284)  corresponding  to  this  series  of  hydrocarbons 
are  isomeric  with  the  phenols.  They  contain  the  characterizing  group 
of  the  primary  alcohols,  CH-iOHj  once  if  the  alcohol  be  monoatomic, 
twice  if  diatomic,  et-c.,  and  they  yield  on  oxidation,  first  an  aldehyde 
and  then  an  acid.  Thus:  C«H.%.CHiiOH  ^  benzylie  alcohol;  CbH$.- 
CHO^ benzoic  aldehyde;   CeHr^COOH^^  benzoic  acid. 

They  are  capable  of  yielding  isomeric  products  of  further  sub- 
stitution, ortho,  para,  or  raeta. 

Benzylic  Alcohol  ^ — ^Benzolc  Alcohol — ^Benzyl  Hydrate — CoHj.- 
CH2OB. —  does  not  exist  in  nature,  and  is  of  interest  chiefly  as 
corresponding  to  two  important  compounds,  benzoic  acid  and 
benzoic  aldehyde  (oil  of  bitter  almonds) .  It  is  obtained  by  the  action 
of  potassium  hydroxid  upon  oil  of  bitter  almonds,  or  by  slowly 
adding  sodium  amalgam  to  a  boiling  solution  of  benzoic  acid. 

It  is  a  colorless  liquid;  boils  at  206,5*^  (403.7°  P  J ;  has  an  aro- 
matic odor-  is  insoluble  in  water,  soluble  in  all  proportions  in  alcohol, 
ether,   and   carbon   bisulfid.     By  oxidation    it   yields,   first,    benzoic 


ALDEHYDES 


453 


aldehyde,  Cells. CHOj  and  afterward,  benzoic  acid,  CeHs.COOH. 
By  the  same  means  it  may  be  made  to  yield  products  similar  to  those 
obtained  from  the  alcohols  of  the  saturated  hydroearbous. 

Secondary  and  tertiary  aromatic  alcohols  are  also  known,  such 
as  phenyi-methyl  carbinol.  Calls, CHOH.CH.i^  and  phcnyl-diniethyl 
carbinoU  C6H5.COH(CH3)2  (p.  285).  The  secondary  alcohols  yield 
I  ketones  on  oxidation  (p.  455). 

Di-  and  tri-hydric  alcohols,  such  as  the  xylylcne  glycols,  CoHi- 
|(CH20H)2  (p,  294),  and  mesitylene  glycerol,  CnH3.(CH20H)3(i.,.5)» 
f^r^  also  known,  as  well  as  alcohols  with  unsaturated  lateral 
chains,  such  as  cinnamic  alcohol*  CfiHo.CHrCHXJHaOH,  which 
txscurs  as  its  cinnamic  ester  in  storax.  It  oxidizes  to  cinnamic  aide- 
liyde  (p.  454)  and  cinnamic  acid  (p.  457). 


ALPHENOLS,  OE  OXYPHENYL  ALCOHOLS. 

These  substances  are  intermediate  in  funetiou  between  the  alcohols 
And  the  phenols,  and  contain  both  substituted  groups  OH  and 
CH2OH. 

Saligenin — o-Oiyhenzylk  Akohol — CeHix^Qn''     —is obtained  from 

salicin  (p.  467)  in  largre,  tabular  crystals-    quite  soluble  in  alcohol, 
'  water,  and  ether.    Oxidizing  agents  convert  it  into  salicylic  aldehj'de, 
which   by  further  oxidation  yields  salicylic  acid.     It  is  also  formed 
by  the  action  of  nascent  hydrogen  on  salicylic  aldehyde. 


ALDEHYDES, 


H        The  aromatic  aldehydes  (p*  299)  are  the  first  product-s  of  oxidation 
W  of  the  aromatic  alcohols.     Monaldehydes  containing  one  CHO  ^roup 
and  dialdehydes  containing  %vfo  such  groups  are  known. 

The  monaldehydes  are  formed;    (1)  By  oxidation  of  the  alcohols; 

^  (2)  by  decomposition  of  the  alcohol  bichlorids  by  water:   CoHs^CHCla 

■  +  H2b  =  CoH5,CHO  +  2HC1.      (3)  By  oxidation  of  the  alcohol  mono* 

^  chlorids  by  lead  nitrate:   C^Hb-CH^CI  +  0  =CeH5.CH0  +  HCL     (4) 

By  the  action  of  ehromyl  dilorid,  Cr02Cl2,  upon  the  hydrocarbons, 

and  decomposition  of  the  addition  compound  by  water. 

Benzoic  Aldehyde  —  Benzoyl  hydrid— C0H5.CHO  —  is  the  main 
constituent  of  oil  of  bitter  ahnonds,  although  it  does  not  exist  in 
in  the  almond  (see  p.  466).  It  is  formed,  along  with  hydrocyanic 
acid  and  glucose,  by  the  action  of  water  upon  amygdalin.  It  is 
also  formed  by  the  general  methods  given  above;  by  the  dehydration 
of  benzylic  alcohol;  by  the  dry  distillation  of  a  mixture  in  molecular 
proportions  of  calcium  benzoate  and  formate;   by  the  action  of  nas- 


451 


MANUAL   OP   CHEMISTBT 


cent  hydrogen  upon  benzoyl  cyanid,  etc.     It  is  obtained  from  bitter 

almonds.     The  crude  oil  contains,  besides  benzoic  aldehyde,  hydro- 
eyanic  and  benzoic  acids  and  benzoyl  cyan  id. 

-  It  is  a  colorless  oil,  having  an  acrid  tast*  and  the  odor  of  bitter 
almonds;  sp.  gr.  1.050;  boils  at  179.4°  (354.9°  F.);  soluble  in  30 
parts  of  water,  and  in  all  proportions  in  alcohol  and  ether.  Oxidiz- 
ing agents  convert  it  into  benzoic  acid,  a  change  which  occurs  by 
mere  exposure  to  air.  Nascent  h.vdrogen  converts  it  into  benzylic 
alcohol.  With  CI  and  Br  it  forms  benzoyl  chlorid  or  broinid.  H^SOi 
dissolves  it  when  heated,  forming  a  purple-red  color,  which  tun]!? 
black  if  more  strongly  heated.  It  forms  a  series  of  products 
substitution,  haloid,  nitro,  amido,  etc. 

When  perfectly  pure,  benzoic  nldehyde  exerts  no  deleterious  action 
when  taken  internally;  owing,  however,  to  the  diffitmlty  of  com- 
pletely removing  the  hydrocyanic  acid,  the  substances  usually  sold  as 
oil  of  hitter  (dmonds,  ratafia,  and  almond  flavor^  are  almost  alwa^iv 
poisonous,  if  taken  in  sufficient  qnan ti ty.  They  may  contain  as 
ranch  as  10*15  per  cent,  of  hydrocyanic  acid,  although  said  to  be 
*^ purified."  The  presence  of  the  poisouons  substances  njay  be  de- 
tected by  the  tests  gi%^en  on  page  392. 

Salicylic  Aldehyde — SaJkifl  htfdrid — 8*ilkylal — Salicylous  acid — 
(i'Oxtfbenzaldehyde  —  CflIl4(0H)  (CHO)^,!  —  exists  iu  the  flowers  of 
i^pircBa  ulmaria,  and  is  the  principal  ingredient  of  the  essential  oil 
of  that  plant.     It  is  l>est  obtained  by  oxidizing  salicin  (p.  467), 

It  is  a  colorless  oil;    turns  red  on  exposure  to  air;   has  an  agree- 
able, aromatic  odor,  and  a  sharp,  burning  taste;   sp.  gr.   1,173  at 
13.5"*  (56. 3"^  FJ:    boils  at  196, 5"^  (385.7°  F.);    soluble  in   wat 
more  so  in  alcohol  and  in  ether. 

It  is,  as  we  should  suspect  from  its  origin,  a  substance  of  mixed 
function,  possessing  the  characteristic  properties  of  aldehyde  and 
phenol.  It  produces  a  great  number  of  derivatives,  some  of  which  are 
salts  or  esfceis,  such  as  p-methoxybenzaldehyde,  or  anisic  aldehyde, 
CoH4{CHO}(OCH:j),,h  a  product  of  oxidation  of  anethol  (p.  430). 

Vanillin— Methylprotocatechuic  Aldehyde  —  m  *  Methoxy -  p-oxy* 
benzaldehyde  —  C0H3.CHO. {O.CHa)r3)(OH)r,  — a  methylated  dioxy* 
benzaldebyde,  is  the  odoriferous  principle  of  vanilla.  It  is  produced 
artificially  by  oxidation  of  coniferin,  Ci6H220gt  a  glucosid  occurring  in 
coniferous  plants  (p.  466).  It  crystallizes  in  needles,  fuses  at  80^ 
(176°  F.),  is  sparingly  soluble  in  water,  readily  soluble  in  alcohol 
or  ether.  It  has  a  pungent  taste  and  a  persistent  odor  of  vanilla. 
On  exposure  to  air  it  becomes  partly  oxidized  to  vanillic  acid^ 
CgHaOi. 

Cinnamic  Aldehyde  —  0  Phenyl- acrolein  —  C0H5-CH :  CH ,OHO— 
is  an  -example  of  the  aromatic  aldehydes  with  unsaturated    lateral 


at 


^ 


AROMATIC    CARBOXYLIC    ACIDS  455 

ehaiDs,  It  is  the  chief  constituent  of  oil  of  cioDamonj  and  is  a 
colorless,  aromatic  oil,  boiling  at  247^  (470.6°  FJ.  It  oxidizes 
readily  to  cinnamic  acid  (p.  457). 


KETONES- 

The  aromatic  ketones  (p.  307)  are  produced  by  the  oxidation  of 
the  secondary  aromatic  alcohols  (p.  453)  ;  2C6H6.CHOH.CH3+02= 
2H20+2CflH5.CO.CH3i  or  by  the  action  of  caustic  potash  upon  the 
aromatic  0  ketone -car  boxy  lie  acids  {p,  464):  C0H5.CO.CH2.COOH  + 
2KH0  =  CfiHs.CO.CHa  +  H2O  +  K2CO3.  Monokctones,  dikctoncs 
and  triketones,  containing  one,  two  and  three  lateral  chains  with 
CO  grroups,  are  known.  The  monokctones,  also  called  phenones, 
consist  of  a  closed  chain  hydrocarbon  group  united  to  an  open  chain 
one  by  the  g'roup  (CO)^'.  They  may  also  be  considered  as  benzene, 
into  which  fatty  acid  radicals  have  been  substituted  for  hydi-ogcn 
(see  p.  504). 

Phcnyl-methyl  Ketone — Acetyl  benzene — AcetophenQne — Hyp- 
none — C«Hg.CO,CH:j — is  obtained  by  distilling  a  mixture  of  calcium 
benzoate  and  acetate;  by  the  action  of  zinc-methyl  upon  benzoyl 
chlorid;  or  by  the  action  of  acetyl  chlorid  or  bromid  upon  benzene 
tn  the  presence  of  aluminium  chlorid.  It  forms  large  crystalline 
plates,  fusible  at  20^  (68"^  F.).     It  has  been  used  as  a  hypnotic, 

Acctophcnone  Oxim  —  CaHs.!':  (N.OH)  .CH3 —  is  isomeric  with 
acetanilid,  CeHfi.NH(CO.CHH),  and  is  converted  into  that  substance 
by  the  action  of  concentrated  II2BO4  (p.  475). 


AROMATIC    CARBOXYLIC   ACIDS. 

All  six  of  the  hydrogen  atoms  of  benzene  are  replaceable  by 
carboxyl  groups,  with  formation  of  monoearboxylic  acids,  dicarboxylic 
acids,  etc.  There  are  also  three  series,  o-,  m-,  and  p-,  of  the  bi-, 
tri-,  and  tetracarboxylic  acids,  and  of  the  monoearboxylic  acids 
above  the  first.  These  acids  may  be  obtained  by  oxidation  of  the 
corresponding  alcohols,  or  aldehydes,  where  these  are  known.  Like 
the  aliphatic  aeids,  they  may  be  considered  as  being  derived  from 
the  hydrocarbons  by  substitution  of  hydroxyl  and  oxygen  for  hydro- 
gen  in  a  lateral  chain  (p,  2B2). 

MONOCARBOXYLIC    AROMATIC    ACIDS — BENZOIC    SERIES* 

These  acids  are  formed  by  many  methods,  among  which  the  most 
important  are;  (1)   By  oxidation  uf  the  lateral  chain  in  hydrocarbons 


456 


MANUAL    OF    CHEMISTRY 


homologous  with  benzene.  Thus  toluene  yields  benzoio  acid:  2C6H5.- 
CH3+a02=  2CeH5.COOH+2H20;  (2)  by  oxidation  of  the  correspond- 
ing alcohols  and  aldehydes;  (3)  by  the  action  of  sodiura  and  carbon 
dioxid  upon  the  raonobroinobeiizenes:  CflH5Br+0O2+2Na==NaBr+ 
CflHs.COONa ;  (4)  by  deciimposition  of  the  aromatic  acid  nitrils  by 
acids  or  alkalies  (pp.  328,428):  CeH5,CN+KHO+H2O=0ftH5XOOK+ 
NHa*  (5)  By  fusion  of  the  aromatic  sulfonic  acids  with  sodium  form- 
ate: CoH&.S03Ka  +  H,COONa-=C6H5.COOXa+  NaHSOa. 

The  acids  of  this  series  form  many  derivatives.  In  some  of  these 
the  carboxyl  is  modified,  leaving  either  the  radical  benzoyl,  C0H5.CO, 
as  in  benzamid,  C0HG.CO.NH2,  or  the  trivalent  group  bcnzenyl, 
CflHs.C,  as  in  benzenyl-amidin,  CeH^.C^^^".  In  others  the  substi- 
tution occurs  in  the  benzene  ring,  as  in  the  oxy-,  halogen-,  and 
nitro- benzoic  acids,  etc.,  e.g.  anthranilic»  or  o-amido-ben^oic  acid, 
CeH4.COOH,,,(NH2)<«). 

Benzoic  Acid  —  CeHg-COOH — exists  in  benzoin,  tohi  balsam,  cas- 
toreum,  and  in  several  resins.  It  is  obtained  by  the  general  methods 
given  above;  also  fi*om  benzoin,  and  from  the  urine  of  herbivorous 
animals.  The  urine  contains  hippuric  acid  (p.  479),  which,  on  de- 
composition, yields  benzoic  acid.  Conversely,  when  benzoic  acid  is 
taken  into  the  body  in  moderate  doses  it  is  eliminated  as  hippnric  acid. 

Benzoic  acid  crystallizes  in  white,  transparent  plates,  odorless, 
sparingly  soluble  in  cold  water,  readily  soluble  in  hot  water,  in  alcohol 
and  in  ether j  fuses  at  120''  (248*"  F J,  boils  at  250° (482*"  F.),  and  sub- 
limes at  temperatures  below  its  boiling  point.  Benzoic  acid  is  not 
attacked  hy  HNOa.  Heated  with  lime,  it  yields  benzene  and  cal- 
cium carbonate:  C«H,.COOH  +  CaH202  =  CfiHfl  +  CaCOa  +  H20.  The 
benzoates  are  all  solublt?,  the  least  soluble  being  the  ferric  salt. 

Homologues  of  Benzoic  Acid.^ — These  are  of  two  kinds  :  (1) 
Those  in  which  the  carboxyl  and  hydrocarbon  groups  replace  different 
hydrogen  atoms,  the  alkyl* benzoic  acids,  as  cumic  acid,  or  p-isopro- 
pyl  benzoic  acid,  aH4.(C3H7)(.>(COOH)<4>.  (2)  Those  in  which  the 
carboxyl  is  separat^jd  from  the  benzene  ring  by  a  hydrocarbon  group, 
the  phenyl  fatty  acids,  as  phenyl-acetic  acid,  C15H5.CH2.COOH.  In 
the  terras  above  the  first  of  this  series  there  are  place  isomeres  accord- 
ing to  the  distance  from  the  ring  in  which  the  carboxyl  is  introduced. 
Thus  ^  phenyl-propionic  acid*  C^Hs.CH^^Qg^  ,  and  fi  phenyl-pro- 
pionic  acid,  CaH5.CH2.CH2.COOH. 


POLYCARBOXTLIC    AKOMATIC    ACIDS. 

The  di-,  tri-,  tetra-,  penta-,  and  hexa-carboxylic  aromatic  acids 
are  derived  from  benzene  by  substitution  of  from  two  to  six  car- 


AROMATIC    CARBOXYLIC    ACIDS 


457 


boxy  Is  for  hydrogen  atoms.  Of  the  superior  homologues  there  exist 
a  number  of  isomeres,  increasing  with  the  nninber  of  carbon  atoms, 
according  as  the  carboxyls  are  attached  to  the  benzene  ring^  as  in  the 
phthalie  acids»  or  are  contained  in  lateral  chains,  as  in  phenyl- 
malonic  acid,  CeHi.ClKCOOH)^,  and  varying  further  by  diJferences 
in  orientation  either  in  the  benzene  or  the  lateral  chains. 

Phthalie  Acids  — CeHJCOOID-j^Ortho-,  meta-,  and  para- 
ph thalie  acids  are  produced  by  oxidation  of  the  corresponding 
bisubstituted  benzene  derivatives,  and  serve  by  their  formation  to 
determiuc  whether  a  given  componnd  is  o-,  ra-,  or  p*. 

Phthalie  Acid — Benzene -o-dicarboxylic  acid— CflTl4(COOH)2(c.a; 
— is  obtained  :  (1)  indostriaily  by  oxidation  of  naphthalene  or  tetra- 
chlorouaphthalene,  for  use  in  the  manufacture  of  the  phthaknn  dyes; 
(2)  by  oxidation  of  o-xylene,  o-toluic  acid,  etc;  (o)  by  direct  union 
of  carbon  monoxid  with  salicylic  acid  :  CcHi-OILCOOII  +  t^O^CeHj- 
(€0011)2;   or  with  resorcinoh   C6H4(OH)2+2CO=C6HaC0OH)2. 

Phthalie  acid   crystallizes   in  prisms,   sparingly  soluble    in    cold 

,  water,  readily  soluble  in  hot  water,  alcohol,  and  ether,  fuses  at  213^ 

'  (415,4^  F.).    Heated  with  CaHaO^^  it  is  decomposed    into   benzem^ 

and  COj.     Nascent   hydri>gen  converts  it  into  hydrophthalic  acids 

(p.  492).     It  is  the  only   phthalie  acid  which  yields  an  anhydrid. 

Isophthalic  Acid^^ — Benzene-m-dicarboxylic  acid — CfiH^iCOOII  )'2* 
tt.D — is  fornjed  by  oxidation  of  m-xylene,  m-toluic  acid,  and  other 
rn-beuzene  bisubstituted  derivati%''es.  It  crystallizes  in  fine  needles, 
sparingly  soluble  in  water,  soluble  in  alcohol .  fuses  and  sublimes 
above  30(>°  (572'^  FJ. 

Tcrcphthalic  Acid^ — Benzene-p-dicarboxylic  acid^CaH^  ( COOH )  2- 
H.41 — is  formed  by  oxidation  of  p-xylene,  p-tohnc  acid,  and  other 
p-benzene  bisubstituted  derivatives.  It  is  insoluble  in  water,  alcohol, 
and  etlier,  and  sublimes  without  melting. 


UNSATURATED    AROMATIC    CARBOXYLIC    ACIDS. 

Phenyl-olefin  carboxylic  Acids—In  some  of  these  acids  the  car- 
iKixyl  is  attached  to  tlie  benzene  ring,  as  in  o-vinyl-benzoic  acid, 
COOH.C6ll4.(CH:CH2)(3).  In  those  best  known  the  carboxyl  is  in 
the  lateral  chain.  They  are  obtained  by  oxidation  of  the  correspond- 
ing alcohols  or  aldehydes  (pp.  453,  454). 

Phcnyl-acrylic  Acids — Two  are  known  ;  Atropic  acid,  »  Phenyl- 
acrylic  acid,  CelU-Cv^cn.^  ,  a  product  of  decomposition  of  tropic 
acid  (p.  463);  and  cinnamic  acid,  ^  phenyl-acrylic  acid,  CeHs.CH:* 
CH.COOH,  which  exists  in  several  balsams  and  resins,  and  is  pro- 
duced in  the  decomposition  of  certain  alkaloids.  It  is  also  formed 
from  benzoic  aldehyde  by  the  action  of  acetyl  chlorid:  CH:j.C0.C1+ 


458 


MANUAL    OP    CHEM18TBY 


CfHB.CH0  =  CttH5.CnrCH.C00H  +  HCl;  oi%  with  tlie  iutermediate 
formatioQ  of  phenyl -^-oxypropionie  acid,  by  the  acttion  of  sotliuin 
acetate  in  preseoce  of  aeetic  aohydrid:  C6ll5.CHO+CH3AOOXa  = 
CfiH5.CHOH.CH2,COONa,  and  CeH:.CHOH.CU2.COONa=CfiavCH:- 
€H.COONa+H20^  It  crystallizes  in  prisms,  fuses  at  WS^  (211  A""  F.). 
sparingly  soluble  in  cold  water,  readily  soluble  in  hot  water.  Oxidizing 
agents  convert  it  intu  benzoic  aldehyde  and  benzoic  acid.  It  com- 
bines with  hydrogen  to  form  hydrocinnamic,  or  ^  phenyl-propionic 
acid,  CeHs.CHo.CHo.COOH.  Nitric  acid  converts  it  into  a  mixture 
of  o-  and  p-nitro-cinnamic  acids,  the  former  of  which  is  the  starting 
point  in  a  synthesis  of  indigo. 

On  heating  with  H^O  or  HCl,  atropic  acid  is  converted  into  two 
polymeric  isatropic  acids«  or  diatropic  acids,  (CgHgO^)?. 

Piperic  Acid,  obtained  l>y  decomposition  of  piperin  by  heating 
with  alcoholic  KHO,  is  3-4- Methylene- dioxy-cinnamenyb acrylic  acid: 


/0-C 


C.CH:CH.CH:CH.COOH. 


\0- 


—  CH^ 


I 


Phenyl-propiolic  acid=CiiH5.C  :  CCOOH — is  a  phcnyl-acetylcnc 

carboxylic  acid,  produced  by  the  action  of  carbon  dioxid  upon  pheuyl- 
acetylene:  C,n.v(^  i  CH+COo^CeHs.C  ■  C.COOH.  Its  o-nitro  de- 
rivative forms  isatin  (p.  541)  when  boiled  with  alkalies* 


PHENOL  CARBOXYLIC  ACIDS  AND  THEIR   ESTERS. 

These  compounds  ha%^e  both  hydroxyl  and  carboxyl  attached  to 

the  benzene  ring.  They  have  the  functions  of  phenol  and  of  acid. 
They  are  formed:  (1)  by  fusing  the  snlfobenzoic  acids  with  alkalies: 
CBH4(COOH)SOaH+KHO=S03HK+C6H4(COOU}(OH),  (p,  444). 
Also  similarly  from  the  haloid  acids:  C6H4.Br.COOn+KHO^C6H4.- 
OH,COOII+KBr  •  (2)  by  fusion  of  the  homologues  of  phenol  with 
caustic  potash, the  methyl  of  the  liydrocarljon  lateral  chain  is  oxidized 
to  carboxyl;  (3)  by  oxidation  of  the  phenol -aide  by  deg  by  fusion  with 
caustic  alkalies;  (4)  by  saponification  of  their  esters,  produced  by 
oxidizing  the  sulfuric  or  phosphoric  esters  of  the  homologQes  of  phe- 
nol; (5)  by  heating  the  phenols  with  carbon  tetrachlorid  and  caustic 
potash  :  CfiH5.0H+CCU+4KHO=CoH4X>H.COOH  +  2H20+4KC1; 
(6)  by  the  action  of  carbon  dioxid  upon  the  sodium  phenates:  2C6H5.- 
O.Na+C02=CfiH4.0.Na.COONa+Ur]s.OH. 

Di-,  tri->  and  tetra- carboxylic  oxyacids  are  known.  But  the  best 
known  of  the  oxyacids  arc  monocarboxylic,  and  monoxy-,  dioxy-,  and 
trioxy-,  corresponding  to  the  phenols  of  like  hydroxyl  content. 


PHENOL   CAKBOXYLIC   AClUii   AND    THEIE   ESTERS 


MONOXY-MONOCARBOXYLIC    ACIDS. 


Oxybcnzoic  Acids  — CaEg. OH. COOH. —  Of  the  three  isomeric 
acids  the  meta-,  f.  p.  200°  (392*'  ¥.),  and  the  para-,  f,  p.  210° 
(410*''  P.),  acids  are  obtained  by  the  action  of  KHO  on  the  corre- 
8poudiug  bromobenzoic  acids. 

Salicylic  Acid— o-Oxybenzoic  Acid  — f.  p.  155°  Oil"*  F.), 
occui*s  free,  accompanied  by  salicylic  aldehyde  (p.  454),  in  SpircEa 
ulmaria  and,  as  its  methylic  ester,  in  oil  of  wintergreen.  It  is  also 
formed  hy  decomposition  of  salicin,  coumarin  or  indigo.  It  is  pro- 
duced synthetically  by  the  above  reactions  and,  iodustrialJy,  by 
heating  sodium  phcnate  in  a  current  of  carbon  dioxid.  The  reaction 
18  not  CcHs.ONa  +  COs^CeHi.OH.COONa,  but  2CaH5.0Xa+ COa^ 
C1H5.OH  +  OoHi.ONa.COONa. 

Salicylic  acid  crystallizes  in  prisms  or  needles,  sparingly  soluble 
in  cold  water,  readily  soluble  in  hot  water,  alcohol  and  ether,  sweet 
and  acid  in  taste.  When  heated,  it  distils  in  part  unchanged,  while 
a  part  loses  oxygen  and  yields  siilol  and  xantbone,  CiaHioOj;  or  salol, 
carbon  dioxid  and  water  (see  below).  With  CI  and  Br  it  forms  pro- 
ducts of  substitution,  With  fuming  HNO3  it  forms  a  nitro-acid  and, 
finally,  picric  acid.  With  ferric  chlorid  it  gives  a  fine  violet  color. 
Nascent  hydrogen  causes  rupture  of  the  ring,  with  formation  of 
pimelic  acid  (p*  338)  as  a  final  product.  Salicylic  acid  and  its  salts 
and  esters  are  used  as  antiseptics  and  as  antirheumatics. 

Phenyl  Salicylate  — Salol—CflEi, OH, COO (CgHv)  — is  formed  by 
heating  salicylic  acid  to  220°  (428°  FJ:  2CflH4X>e,COOH  =  CflH4.- 
OH.COO(CflH5)+ 00^+ H2O:  also  by  the  action  of  POCI3  on  a 
mixture  of  salicylic  acid  and  phenol.  It  is  a  white,  crj^stalline  pow* 
der,  faintly  aromatic  in  taste  and  odor,  almost  insoluble  in  water, 
soluble  in  alcohol,  ether  and  benzene,  fuses  at  43^^  (110°  Fj.  It  is 
not  decomposed  by  weak  aetds^  but  is  saponified  by  alkalies  to  form 
salicylic  acid  and  phenol;  hence  it  passes  unchanged  through  the 
stomach  to  be  decomposed  in  the  intestine:  CVH4.0H.COO{C6H5)  + 
H2O  ^CcHi.OH.COOFI  +  CflHfi.OH. 

Acetol  Salicylate  —  Salacetol  —  C6H4,OH.COO(CHL^CO.CH3)  — 
the  ester  of  the  keto- alcohol,  acetol  (p.  308)*  is  formed  by  the  action 
of  monochloraeetone  on  sodium  salicylate.  It  crystallizes  in  plates > 
spariugly  soluble  in  water,  readily  soluble  in  alcohol,  fusible  at  71^ 
(159.8°  FJ.  It  is  saponified  by  alkalies  with  formation  of  acetol 
and  salicylic  acid,  and  is  hence  substituted  for  salol  as  a  medicine 
when  the  formation  of  phenol  is  undesirable.  Like  acetol  and  its 
other  esterSj  it  reduces  Fehling^s  solution. 

The  superior  honiologucs  of  the  salicylic  acids  are  either  alkyl  sub- 
stituted derivatives  of  the  oxybenzoie  acids  or  oxy phenyl  fatty  acids: 


460 


MANUAL    OF    CHEMISTRY 
iXX>H  COOH 


CHa.COOH 


CH3 

OH 

o-SalksyUe 

Orthozyiwrstoliiie 

•dd. 

acid. 

Mid. 

Paraoxyphenylacetic  acid  and  paraoxyphenylpropionic  acid» 
C6H4(OH)(.,  (CH2.CH2.COOH)(4),  the  latter  also  called  hydroparacou- 
marie  acid,  exist  in  the  urine  in  ** alkaptonuria,"  accompanied  by 
paraoxyphenylglycoUic  acid,  C6H4(OH)c.)(CHOH.COOH)(4,,  and  the 
dioxycarboxylic  acids  mentioned  below.  They  are  products  of  de- 
composition of  protein  material. 


DI-   AND   TRIOXYMONOCARBOXYLIC   ACmS. 

Dioxycarboxylic  Acids. —  The  six  isomeres  corresponding  to  the 
three  diphenols  are  known,  as  well  as  numerous  alkyl  derivatives, 
such  as  vanillic,  isovanillic  and  veratric  acids,  which  are  derived  from 
protocatechuic  acid.  The  relations  of  these  acids  are  shown  by  the 
following  formulae: 


PYROCATECHOL,. 
OH 


a  =  3.4-Diozybenzoic. 

=  Protocatechnio. 
/)  =  2.3-Diox7benzoic, 


OH 


0 


COOH 
YanUlie  acid. 


RESORCINOL. 
OH 


OH 


*  -  Resorcylie, 

=  3  5-Dioxyb6nM>ic, 

P  -  Resorcylie, 

^  2.4-Dioxy benzoic. 

y  Resorcylie, 

=  2.6-Dioxybenzoic. 


0(CH3) 


COOH 
Isovanillic  acid. 


OH 

2.5--Diozy  benzoic, 
=  Gentisinic. 
=  Uydroqainone-ear 
boxy  lie. 


0(CH,) 

0(CH,) 


0 

COOH 
Veratric  acid. 


PHENOL   CARBOXYLIC   ACIDS   AND  THEIK    ESTERS 


461 


Protocatechuic  Acid— 3,4'Dioxybenzoic  Acid— CdHaC COO H) ur 
(011)3^.41 — exists  in  the  fruit  of  the  star -anise,  aud  is  produced  from 
many  resins  by  fusion  with  KHO.  It  is  forojed  by  fusion  of  dibro- 
mobenzoic  acid,  and  other  similar  derivatives,  with  KHO. 

The  superior  homQlogucs  of  dioxycarboxylic  acids  are  either 
dioxytoluic  acids,  etc.,  such  as  orselltnic  acid,  or  dioxy-phenyl  fatty 
acids,  such  as  homogetitisinie  acid: 


CH..CLXJH 


HO 


CHa 

'  Oneiliiilc-  ^  Uomofeutisiaie. 


CHa.CHOH.COOH 


OH 


OH 

S ,  4-Dioxypheny  1  •  AC«t  I  v .      3.4^  Dtoiyp  hanr  1  'laetle . 
=  Homoprotocfttechaio<     -»  Uroleueic  if} 


Homogentisinic  acid,  or  glycosuria  acid,  exists  in  the  urine  iu 
'* alkaptonuria,'*  probably  aeeonipanied  by  homoprotocatechuic  and 
uroleucic  acids,  as  well  as  by  the  mouoxy*monocarboxylic  acids 
mentioned  above. 

Trioxycarboxylic  Acids. ^ Three  of  the  six  possible  acids  are 
known t  two  derived  from  pyrogallol,  one  from  phlorogluein  (p.  449). 

Gallic  Acid —  CtfH2{l'OOH)ci)(OH)3r3.4,st' — exists  in  nature  in  cer- 
tain leaves,  seeds  and  fruits.  It  is  best  obtained  from  nut-galls,  which 
contain  its  glucosid,  gallo- tannic  acid.  It  is  formed  when  bronio- 
protr>eatechuic  acid  is  fused  with  eaustic  potash.  It  crystallizes  in 
long,  silky  needles  with  lAq,  odorless,  acidulous  iu  taste,  sparingly 
soluble  in  cold  water,  very  soluble  in  hot  water  and  in  alcohol.  Its 
solutions  are  acid.  When  heated  to  210-215°  it  yields  CO2  and  pyro- 
gallol (p.  450).  Its  solutions  reduce  th*-  salts  of  silver  and  of  gold; 
they  do  not  precipitate  gelatin  nor  the  salts  of  the  alkaloids,  as  does 
tannin;   and  they  give  a  bhie-hlack  precipitate  with  Fe2Cl(j. 

Tannins — Tannic  Acids  —  are  substances  of  vegetable  origin, 
principally  derived  from  leaves,  barks  and  seeds.  They  are  amor* 
phous,  soluble  in  water,  astringent^  capable  of  precipitating  albumin, 
of  forming  imputreseible  compounds  with  the  gelatinoids  (leather), 
and  give  green  or  blue  colors  with  the  ferric  salts. 

Pure  tannic  acid  has  been  obtained  by  removal  of  water  from 
gallic  acid:  2C7HejOs=CiiHio08+H20;  it  is,  therefore,  digallic  acid. 
It  exists  in  gall-nuts,  excrescences  produced  upon  oak  trees  by  the 
punctures  of  certain  insects  (gallo-taunie  acid).  It  is  colorless, 
amorphous,  odorless,  very  soluble  in  water,  less  so  in  alcohol,  almost 
insoluble  in  ether.  It  forms  a  dark-blue  liquid  (ink)  with  solutions 
of  ferric  salts  or,  after  exposure  to  air,  with  ferrous  salts. 


462  MANUAL    OF    CHEMISTRY 

Caffetannic  Add,  CaoHigOie,  exists  in  saline  combination  in  coffee 
and  Paraguay  tea.  It  colors  the  ferric  salts  green,  precipitates  the 
salts  of  qninin  and  cinchoniu,  but  not  tartar  emetic  or  gelatin,  as 
tannic  acid  does.  It  yields  caffeic  add,  or  3-4-dioxycinnamic  add, 
C9H8O4,  on  decomposition.  Cadioutannic  add,  obtained  from  ca- 
techu, is  soluble  in  water,  alcohol  and  ether.  It  precipitates  gelatin, 
but  not  tartar  emetic,  and  colors  ferric  salts  grayish -green.  Monn- 
tannic  add,  or  madurin,  CisHioOe,  is  a  yellow,  crystalline  substance, 
obtained  from  fustic.  It  is  more  soluble  in  alcohol  than  in  water. 
Its  solutions  precipitate  greenish -black  with  ferric  salts,  yellow 
with  lead  acetate,  brown  with  tartar  emetic  and  yellowish-brown 
with  cupric  sulfate.  Quercitannic  add.  CigHieOio,  is  the  tannin  of 
oak  bark.  It  is  a  red  powder,  sparingly  soluble  in  water,  which 
forms  a  violet-red  precipitate  with  ferric  salts.  Quinotannic  add 
exists  in  cinchona  barks,  in  combination  with  the  alkaloids.  It  is 
light  yellow,  soluble  in  water,  alcohol  and  ether,  astringent,  but  not 
bitter  in  taste.  It  is  colored  green  by  ferric  salts.  Dilute  H2SO4 
decomposes  it  with  formation  of  quina  red,  an  amorphous  substance, 
which  yields  protocatechuic  and  acetic  acids  on  further  decompo- 
sition. 

ALCOHOL-,   ALDEHYDE-,   AND    KETONE-CARBOXYLIC   AROMATIC 
ACIDS;    AND    THEIR   ESTERS. 

The  aromatic  alcohol-adds  are  of  two  classes:  (1)  alcohol-car- 
boxylic  adds,  in  which  the  group  CH2OH  is  attached  to  the  benzene 
ring,  and  (2)  phenyl-paraffin  alcohol-adds,  which  contain  either 
ClhOH;   CHOH  or  (CHO)''' in  a  lateral  chain. 

The  three  oxymethyl- benzoic  acids  are  the  best  known  of  these 
acids,  and  of  these  the  o-acid.  C6H4(COOH)ro(CH20H)ra.,  a  whit^ 
powder,  fusible,  with  decomposition,  at  118°  (244.4°  F.),  produced  bjr 
the  action  of  boiling  alkalies  upon 

Phthalid  — C6H4<(c%l/0— its  lactone  (p.  3G8),  which  is  formedt 

by  several  reactions,  as  by  the  reduction  of  phthalic  anhydrid  hy 
nascent  hydrogen.  Phthalid  crystallizes  in  needles,  fusible  at  73^ 
(163.4°  F.),  sparingly  soluble  in  cold  water,  rather  soluble  in  hoti^ 
WAter.  Reducing  agents  convert  it  into  orthotoluic  acid;  oxidizing" 
agents  into  phthalic  acid.  It  forms  a  number  of  substituted  phthal^ 
iUa,  among  which  is  meconiu  (see  also  p.  504). 

Meconin  —  5-6-Dimethyloxyphthalid  —  (CH30)2(5.6>C6H2<^cH2iV<^ 
— th^  lactone  of  meconinic  acid,  and  the  earliest  known   lactone, 
t'xi»U»    in    opium,    and    is    also    formed    by   the    notion    of    reducing" 
agcutK  upon  narcotin.     It  is  also   formed  by  reduction  of  the  corre- 


AROMATIC    ACIDS    AND    THEIR    ESTERS 


463 


I 


npondmg  aldehyde-acid,  opianic  acid,  {CHiOsOaHoxp^Q^,  a  product 
of  decomposition  of  narcotin  and  of  hydrastin.  Mecoiiiii,  or  opianyl, 
is  a  iieuta-al,  nou-poisooous,  crystailiiie  substance,  which  gives  a  fine 
green  L'olor,  uhanging  to  red  after  24  hours,  with  H2SO4. 

The  phenyl- paraffin  alcohol-adds  may  be  considered  as  derived 
from  the  aliphatic  oxyacids  (p.  338)  by  substitution  of  phenyl,  CoHji, 
or  phenylen,  OeHj,  for  hydrogen  in  the  alcohol  or  hydrocarbon 
groups.  They  are  mono*  or  di-carboxylic  and  mono- or  dioxy-,  aud, 
in  the  higher  terms,  «»,  0,  etc, 

Phenylglycollic  Acid— Mandelic  Acid— CaHsC^HOH.COOH— is 

the  lowest  term  of  the  series,  and  exists  in  three  optical  isomeres. 

The  inactive  acid  is  formed  by  the  action  of  nascent  hydrogen  upon 

benzoic  akiehyde,  CaHs.CHO,  or  upon    benzoyl -formic   acid,  CcH^* 

CO, coon.     Oxidizing  agents   convert  it   first  into  benzoyl -formic 

seid  and  then  into  benzoic  acid. 

Phenyllactic  Acids— a  and  /?phcnyllactic  acids.  CflHr,.COH<^^^H, 

«ncl  CoHsX'Hs.CHOH.COOH,  and  «  and  fi  phenylhydracylic  acids, 

OoE5.C*H<(^^^e^  «"^   CflH5.C*H(f^^^^^*^^",  are  known  (p,    341). 

«  phenyllactic  acid,  or  atrolactic  acid,  is  formed  by  oxidation  of 

**■  -   j:>heuylpropionic  arid  (p.  456) ;    or  by  total  synthesis  through  methyl- 

I>li^nyl  ketone  (p.  455).    This  is  first  converted  into  diehlorethylbeu- 

«5e«-fc^"by    phosphorus   pentaehlorid:    CttH5.CO.CH3+PCl6=POCl:,+ 

s*CCl2.CH3^    which   is  converted   into  nietliylbenzoyl  cyauhydriu 


potassium  cyanid:  C6H5.CCl2.CH3+KCN+H:iO=UH5X'OH(^eN 
"»^  ^^SCl+HCl,  and  this  by  cold  concentrated  hydrochloric  acid  into 
«^t:**^lactic  acid:  C«H,vCOH<(^^^+2H20  +  HCl  =  CijH5.C0H<^gg^>j,+ 
-^^^  ^^i^CK  This  synthesis  is  of  interest  as  being  a  step  in  the  total  syn- 
^*^^isis  of  the  isomere  of  atrolactic  acid,  tropic  acid,  and  of  atropin. 

«»-phenylhydracrylie  acid  is  tropic  acid,  the  inactive  modification 

^^    "^Fhich  is  a  product  of  decomposition  of  a  tropin  and  hyoscyamin, 

^^    i^  formed  synthetically  from  atropic  acid  {p.  457),  or  from  atrolac- 

I   ^^^^       acid.     The    latter    is   first   dehydrated   to   atropic   acidi     CuHs.- 

^^^B<fpJ^i^=CeHBXT(I![];^^T  +  ILiO,    which   is   then   converted    into 


^\COOH" 


\COOH 


^  ^hlorhydratropic,  ora*phenyl*0-chloropropiouic  acid,  and  this  is  hy- 


**^*^ted  to  tropic  aeid:  CfiH5XH<f;^>f]+H.O-QH5.CH(J^^{^+HCL 


^1  The  dioxy-alcohol  acids  are  derived  from  the  acids  of  the  glyceric 

■  *^f  leg  ( p.  342 ) .  as  a  phenylglyceric  acid,  CH2OH  C  ( (aHrJ  Oil  .COOH , 

^1  The  dicarboxylic  alcohol-acids  are  tither  benzyl-  or  phcnyl-alcO'^ 

H  ^01  tcids  such  as  benzyl-tartronic  acid,  {C0H5.CH2)  .COH:  (COOH)^; 

^B^  ^^  phenylen   oxydicarboxylic  acids,  such   as  carbomatidelic  acid. 


464 


MA>n:AIi    OP    CHEMISTRY 


C^m  \^>^0H^COOH'    ^^^  pheiiylene  acids  readily  form  phthalid  acids 
(laolfMi«6t)  mort  stable  thau  themselves,  such  as  phthalid-acetic  acid, 


C,KU 


.cu—o 


^  CHCtlOH,  ■ 

Tbe  aromatic  aldehyde  acids  contain  the  carboxyl  and  aldehyde 
gtoitpi  MmAtA  to  the  benzene  ring,  as  in  optanic  acid  (above). 

te  iht  ktti»De  acids  the  ketone  group  (CO)'^  is  necessarily  in  a 
llltril  chftitt.  In  some  of  these  acids  the  ketone  and  carboxyl  groups 
mtt  itk  diff&iiftit  lateral  ehaiDs,  as  in  aceto-benzoic  acid,  C0H4  ^  co  CH  * 
)>al  id  cnot^t  of  them  the  two  groups  are  in  the  same  chain,  and  are 
^  /S»  y,  tj|c.»  aeeording  to  the  removal  of  the  CO  from  the  COOH 
fiiMtti.  Thus  bcnroyl  -  formic  acid,  CaHs-CO/COOH,  is  «,  and 
beoroylaMlic  acid,  CcHs.CO.CH^.COOH,  is  0, 

Beside  the  above  there  are  also  known:  Phenyl-alcohol-ketone 
acicla«  suoh  as  bcnzoyl-glycoUic  acid,CVH5.C0.CH€>ILC00H ;  phenyl- 
<|ikch>ne-«cids,  such  as  bcnzoyi-pjn-oraccinic  acid,  C6H5,CO.CH2.CO.- 
iXH>U,  ph^nyi-ketone-dicarboxylic  acids,  such  as  benzoyl-malonic 

acid,   iVtb.CX),CH]{C00H)2;      and     phcnylen-ketone-dicarboxylic 

''CO. COOH 


acidtt  *uch  as  phthalonic  acid,  OeHis^^QQ^ 


PHENYLIC  ETHERS  — GLUCOSIDS. 


4 


I 


Th^  ox  ids  of  the  aromatic  series^  corresponding  to  the  aliphatic 
«tlieri»  (p.  *M6),  and  containing  two  cyclic  hydrocarbon  groups  united 
by  au  oxygvu  atom,  properly  beloug  among  the  dibeuzenic  compounds 
(p*  439).  but  arc  more  couveniently  considered  here* 

Phenyl  Ether — Diphenyl  Oxid  — (CoHsJaO — is  formed  by  heatiog 
pheuol  wilh  ulinniiiium  ehlorid,  or  with  ziuc  chlorid:  2CaHs.0H  =  Ce' 
Us  i>A  uUa+  H'jOi  ami  by  other  more  circuitous  methods.  It  crystal- 
ll4c»  in  loug  needles,  having  the  odor  of  geranium,  soluble  in  alcohol 
aud  iu  cHier.  Correspooding  to  it  are  a  number  of  derivatives, 
(oruvcd  h\  Kubstitutiou  of  various  univalents  for  the  remaining  phe- 
ttol  hvdnigtu,  ■ 

The  mixed  oxids,  containing  a  phenyl  and  an  alkyl  group,  are  the" 
phwuvl  I'thern  or  phenol  esters,  derived  from  phenol  (p.  446).    They 
iMTv  foruit*d  by  lunitiug  metallic  plienatcs  with  alkyl  halids:    C«H5.0,K 
MMljl^rttllA-CKCHa+KI,  as  the  aliphatic  *Uhers  are  produced  fro 
iMv44ilho  nlcoliolates  and  alkyl  balids  (p.  340). 

Mothyl  phenyl  Ether — Anisol — Cfllls.CCHy — is  a  colorless,  thii 
N^'.Kil.  ^mhIj*  nt  TfrJ^  {303.6°  F.)  without  decomposition.    Sulfuric  aci 
>  a,  with  formation  of  methyl-phenol  sulfonic  acid, 
vt  phenyl  Ether  — Phenetol  —  C6H5.0.C2H5^ is   a  colorless 
^Nui^'  uu  aromatic  odor.   It  boils  at  172°  (34X.6°  P.). 


uJ 


PHENYLIC    ETHER8-GLUC0SIDS 


465 


GLUC081DS. 


I 


The  name^^gliicosid'^  was  first  applied  to  ceitfiin  natural  products, 
some  of  which  are  the  active  constituents  of  inedicinal  plants,  which, 
oil  decomposition   by  dilute  mineral   acids,  yield   glucose  and  some 
other  substance.     Subsequently,  it  was  fnnnd  Uiat  the  sugars  derived 
from  some  of  these  substances  differ  from  glucose  ;   some  are  pen- 
toses,   others    hexoses;     some    rnonosat^ebarids^   others   disaecharids; 
some  aldoses,  others  ketoses.     On  the  other  hand,  the  second  product 
of  deconipositiou  has   been  of  the  most  varied  character,  phenols, 
alphenols,  alcohols,  oxyphcnok,  niouobeiizeoii!  or  dibenzenic,  but,  in 
ill!  those  natural  glucosids  which  have  been  investigated,  alwa>s  a 
^'velic  compound,  containing  a  phenolic  or  an  alcoholic  group.     The 
^lucosids  have  nsually  been  regarded  as  estera  of  glucose,  etc.,  since 
the  alcoholic  character  of  the  sugars  has  been  i*ecognixed,  but,  as 
the  union  of  the  sugar  and  benzeuic  components  is  tlirouf^li  an  oxygen 
aforn,  and  not  by  replacement  of  the  hydrogen  of  a  carboxyl,  they 
Jtre  more  properly  regarded  as  ethers  (p.  348),  formed  by  union  of 
^u     aldose  or  ketose  remainder  with  one  of  a  phenolic  or  alcoholic 
t>^nzenic  compound,  with  cliniiuaLiou  of  lijO.      The  constitution  of 
th^    glucosids  cannot,  however,  be  considered  as  established,  :is  no 
^atrnrwl  glueosid  has  been  obtained  syntbctically,  although  tlie  prod- 
^ct^of  decomposition  of  some  are  comparatively  simple  compounds. 
^^     is  to  be  supfKJsed  that  the  union  takes  phice  through  the  aldehyde 
S^'^>up,   as   the    glucosids  do   nut  reduce  Feh ling's  solution  and    do 
^^t    form  osazones.     They  pnbably  contain  some  such  grouping  as: 

^H2OH.(CH0H)3.CH- — -CH.O.B,  in  which  B  represents  the  beo- 
^^iiic  component. 

The  glueosid?;  are  decomposed  (bydrojyzed)  by  heating  with  dilute 

^^i<is,  or,  at  very  slightly  elevated  ti'mprraturcs,  by  certjiin  enzyiues, 

*^^-'h   as    emolsin*  wliich  exists   in   almonds,   myrosin,  in    mnstard 

&***^ds,  the  invertin  of  malt,  and  salivarj'  and  intestinal  enzymes*  They 

ft^e  very  slowly  hydrolyzed  by  heating  with  water  under  pressure,  if 

^^  all;   and  only  a  few  of  them  aiv  decomposed  by  alkalies. 

The  glucosids  3  idding  pentoses  on  hydrolysis  are  more  properly 
^^ignated  pentosids. 

Phenyl  Glueosid — Glucosyl  phenatc — CflHii05.0.CftHA — is  tlie 
Mtriplfst  of  the  glucosids,  and  is  an  artificial  product,  formed  by  mix- 
ing  alcoholic  so!uti(uis  of  aceto<*hlorbydrose  (p.  368)  and  potastiiiuu 
phenate,  (^HO.(CILCO,.CH:i)4.CIl2n+  CflHr-.O.K  +  4^,>0  =  CHO,- 
(CHOH)4.^1i^.O.CoH^.+KCl+4CHa.COOIl.  It  forms  soluble,  crys- 
t'^lline  needles,  fusible  at  172'',  and  is  decomposed  by  emulsin  into 
j^hicose  and  phenol. 


466 


MANUAL    OF    CHEMI8TKY 


Among  the  more  importaDt  of  the  natural  g^lticosids  are  the  fol- 
lowing : 

i^sculin — CisHkjOb — whi^'.h  exists  in  the  rinds  of  horse-chestnuts. 

It  forms  colorless  crystals,  sparingly  soluble  in  water,  the  solutions 

having  a  brilliant  blue  Jluoresoence,  even  when  very  dilute.     It  forms 

a  yellow  solution  with  HNO:j»  which  becomes  deep  blood-red  on  super- 

saturation  with  ammonia.     It  is  decomposed  by  dilute  mineral  acids, 

or  by  emulsin,  into  glucose  and  aesculetin,  CgHeO*,  which  is  prob- 

>CH:CH 

ably  a  diox  v  *  derivative  of  coumarin  { p .  539) :  CeH2  { OH )  2x         '    * 

^O — CO 

Amygdalin — CsoH^rNOn — exists  in  the  bitter  almond,  in  the  ker- 
nels of  peach-  and  plum -pits,  apple-  and  pear -seeds,  and  a  great 
variety  of  other  plants.  It  crystallizes  in  colorless  prisms  with  3Aq, 
easily  soluble  in  water,  insoluble  in  ether,  odorless,  and  bitter.  It  is 
decomposed  by  dilute  mineral  acids,  or  by  emulsin,  into  two  mole 
cules  of  glucose  and  one  each  of  benzoic  aldehyde  and  hydrocyanic 
acid:  C2oH27NOn+2H20--2C5H70(OH)5+C6H5.CHO+CNH,  By  the 
action  of  alkalies,  particularly  by  heating  with  BaHsO?,  amygdalin 
yields  amygdalic  acid,  C20H28O13,  of  which  amygdalin  appears  to  be 
tbenitril:  C6H70(0H)4.O.0fiHTO(OH)3.O.CH(CflH5)CN,  and  this,  on 
splitting  off  of  the  sugar,  tirst  forms  the  nitril  of  mandelic  acid 
(p.  463):  CtiH5.CHOH.CN,  the  subsequent  decomposition  of  which 
into  C5H&.CH0  and  HON  is  evident.  Amygdalin  itself  is  non-[>oi- 
souous,  but  its  ready  decomposition*  with  formation  of  the  extremely 
poisonouH  hydrorynuic  acid,  is  a  prolific  source  ot  cyanic  poisoning 

Coniferin — CitiH220a — is  a  glucosid  occurring  in  the  inner  bark 
(cambium)  of  coniferous  pknts,   and  in  Jt^sparagiis  and  the  sugar- 
beet.     It   crystallizes    in    silky,  white   needles,  sparingly  soluble  in 
water,   faintly  bitter.      With  phenol  and  concentrated  hydro^Morie 
acid  it  assumes  an  intense  blue  cnhir  (pine- shaving  reaction,  p.  445). 
It   is   decomposed   by  emulsin    into   glucose   and   coniferyl  alcohol, 
which  is  a  hydroxvl-oxvmethvi    ciunamvl    alcohol    (n.   453)  :    CHa- 
_fj  /C6ll3.CH:CH,CH20H.    By  oxidation  with  chromic  acid  it  foi-ms 
glucovanillin,  UGHii05.0.CflH3(OCH;t)CHO,  which  is  decomposed  by3 
emiUsin    into    ghicose    and    vanillin:    methylnrrvfof'jitcchuic  aldehyde 
(p.  454).    Glucovanillin»  containing   an    aldehyde  group,   forms   a 
crj-stalline  compound  with  phenylhydrazin,  and  an  oxim.    By  further 
oxidation  it  forms  glucovanillic  acid,  and  by  reduction,  the   corre- 
sponding alcolfol. 

Daphnlnp  CifiHujOs,  occurs  in  the  bark  of  Daphne  mezereum^  and 
other  species  of  Daphne.  It  crystallizes  in  colorless  prisms,  bitter  anl 
astringent,  sparingly  soluble  in  water  and  in  ether,  soluble  in  alco- 
hol. It  is  colored  *>luish  by  ferric  chlorid.  It  is  decomposed  into  glu- 
cose and  daphnetin,  CuHdOi,  isomeric  with  fesculetin  (above).    Daph* 


4 

n 
4 


'4 

1    ! 

I 


PHENYLIC    ETHEKS-GLUCOSmS 


407 


netin  has  been  shown  to  be  a  dioxycoamanu,  having:  the  hydroxyU 
iu  the  positions  1»  2,  by  its  synthesis  by  t^ooileu«ation  of  pyrogallol 
(p.  450)  and  malic  acid:   C6H-t(OH)j»^,..3>+COOH.CHa.CHOH,COOH 

,0(3,  -  CO 


=H.COOH+2H2O+CeH2(0n)2a.: 


CHu) 


I 


H         Digitalis  Glucosids. — The  active  BubstaDce  of  digitalis  consists, 
in  part  at  least,  of  a  gliieosid,  or  glucosids,  probably  accompanied  by 

t  products  of  decomposittou,  but  the  chemistry  of  these  compounds 
requires  further  investigation.  Digitonin,  C27H440i3(f ),  is  the  most 
Abundant  constituent  of  the  ■* amorphous  digitalins,"  and  has  little  or 
no  therapeutic  value.  It  is  an  amorphous »  white  solid,  very  sol- 
uWe  in  water,  which  crystallizes  from  its  alcoholic  solutions.  It  is 
clcjcomposed  by  dilute  hydrochloric  acid  into  digitoncini  or  digito- 
^enin,  Ci^^04,  glucose  and  galactose.  Digitalin,  (OsHhO^)*.!!), 
separates  in  amorphous  or  nodular  masses  from  it^  alcoholic  solution. 
On  decomposition  it  yields  digitaliresin,  CifiRjaO-j,  glucose  and  digi- 
t3.1ose,  C7H14O5.  It  has  the  physiological  action  of  digitalis  upon  the 
ti**iirt,  and  is  the  principal  constituent  of  "HoraoUe's  digitalin." 
Digitostin,  C2iH3207(!).  crystallizes  in  fine  needles,  insoluble  in  water» 
soluble  in  hot  alcohol  and  in  chloroform.  It  is  the  most  actively 
poisonous  of  the  digitalis  glucosids,  and  is  the  chief  constituent  of 
Nativellc"  s  digitalin."  Digitalin  gives  a  color- react  ion  which  is  not 
sriven  by  digitoxin  :  it  forms  a  golden-yellow  or  brownish  solution 
^Uh  concentrated  H2SO4,  which  becomes  violet-red  by  the  action  of 
Wnain-vapor. 

Indican — ^C^aHniNOiT — is  a  glucosid  occurring  in  the  indigo  plant. 
It  16  a  yellow  or  light  brown  syrup,  which  cannot  be  dried  without 
df^eomposition,  bitter  and  disagreeable  in  taste,  acid  in  reaction »  and 
soluble  in  water,  alcohol  and  ether.  It  is  very  prone  to  decomposi- 
tion. Even  slight  heating  decomposes  it  into  leucin,  indicanin,  C20- 
H&NO12,  and  indiglucin,  CoHjoOo.  A  characteristic  decomposition  is 
tbiit  by  which  it  yields  indigo- blue  (p.  542)  and  indiglucin,  along 
with  other  products:   2C2<!H:,iNOn+4H20=Ci<iHioN202+6CfinM06. 

Myronic  Acid,  CioHu*N8'jOiot  exists  in  the  seeds  of  black  mustard 
as  its  K  salt,  which  is  hydrolyzed  by  myrosin  (p.  465)  into  glucose, 
mOyl  isothioeyanate  (p.  432)  and  KHSO4. 

Phloridzin.C'iiliiiOio,  occurs  in  the  root -bark  of  apple  and  other 
fruit  trees.  When  ingested  it  causes  glycosuria*  It  is  hydrolyzed  by- 
boiling  with  dilute  acids,  or  even  with  water,  into  a  crystalline,  dex- 
tro^yrons  hexose,  phlorodc,  and  phlorctin,  Cir.HuOsi  which  is  further 
d«*co  in  posed  by  hot  alkalies  into  phloroglucin  and  phlorctic»  or  p-oxy- 
hydratropic  acid :  CrjH4(0H)  .C2H4.COOH. 

Salicin — C13H1KO7 — occurs  in  willow^  l>ark.  It  is  a  white*  crys- 
tailine  sabstance^  insoluble  iu  ether,  soluble  in  water  and  in  alcohol. 


L 


488 


MANUAL    OF    CHEMISTRY 


very  bitter  iu  taste.     Concentrated  H2SO4  colors  it  intensely  red,  the 

color  being  discharged  by  addition  ol  water.  It  is  decomposed  by 
emulsiii,  by  saliva,  or  by  mineral  arids  into  glucose  and  saligeniu 
(p.  453).  When  taken  into  the  economy  it  is  converted  into  salicylic 
aldehyde  and  acid,  which  are  elinuuated  iu  the  orine*  PopuUn,  a 
glucosid  from  poplar  bark,  is  benzoyl -salicin. 

Solanin  —  C42Ha7NOi5(f ) — is  a  glacosid  having  basic  properties^, 
ati  alkaloid -glueosid,  occurring  iu  a  variety  of  planfs  of  the  genust 
Sfdannm.     It  crystallizes  in  white,  silky  needles,  arrid  aud  bitter  irk_ 
taste,  insoluble  in  water,  sparingly  soluble  iu  alcohol  and  in  ether.    Bv^ 
the  action  of  hot  dilute  acids  it  is  decomposed  into  glneose  and  sv 
basic  substance,  solanidin. 

ANHYDRIDS    AND    ACID    HALIDS. 

The  aromatic  acidyls  form  oxids,  or  anhydrids,  and   haloid  com^« 
pounds,  corresponding  to  those  of  the  aliphatic  acidyls,  and  produce^-    -d 
by  similar  methods  (pp.  351,  352). 

B e nzo ic  Anh y dri d^ —  ( t'ells .  CO )  2O — is  f 0 rmed  fi-o ra  ben zoy  1  ch  1  ori^  J 
by  several  methods:  as  by  a  reaction  between  benzoyl  chlorid  aa^  d 
silver  benzoate:  CeHs.CO.Cl+Cgtb.COOAg  =  (€6H5.CO)2  0+AgC^L-J. 
It  is  a  crystalline  solid,  f .  p.  42°,  b,  p.  360°. 

Phthalic  Anhydrid — C\(H4(0O)2:O--being  formed  from  a  dieaii^™*' 
boxylic  acid,  is  produced  from  a  single  molecule  of  the  acid,  wit-^-^  h 
eliraioation  of  Hl»0.  It  is  formed  by  fusing  phthalic  acid.  It  snt^^' 
limes  in  needles^  f.  p.  128°  (262.4'^  P.);  sparingly  soluble  in  coM^  d 
water,  soluble  in  hot  water,  with  regeneration  of  the  acid,  verj^  so-  ^' 
uble  in  alcohol  and  in  ether.  It  combines  with  phenols  to  for:^cxi 
phthaleiDs  (p.  451). 

Benzoyl  Chlorid— CaHs. CO. CI  — was  the  first  obtained  of  ttzm^ 
acidyl  halids.  It  is  formed  by  the  action  of  hydrochloric  acid  upcz^*^ 
benzoic  acid,  in  presence  of  phosphorus  pentoxid  :  CeHa.COOH— "^^^ 
HCl=C6H5.CO.Cl+HaOj  or  by  the  action  of  chloriu  upon  benzcs-^  i^ 
aldehyde:  Cfle5.CHO+Cl2=HCl+CaH5.CO.Cl;  or,  along  with  aceti  ^'^ 
chlorid,  by  the  action  of  chlonn  upon  benzyl  acetate  :  CHi.OO^^^' 
(CH2.CflH5)+2Clt=Con5.CO.Cl+CHa.CO.Cl+2HCl.  The  two  ehlc^  ^ 
ids  are  separated  by  fractional  distillation. 

Benzoyl  chlorid  is  a  colorless  lL(]nid;  b.  p.  198**;   having  a  pen^  ^' 
trating  odor.      With  silver  (or  mercuric)  cyanid  it  forms  benzc^J^ 
cyanid:    C,jHi>.C0.Gl+AgCX=CifH5.C0.CN+AgCl.     It  acts  readi  I-^ 
upon  the  polyatomic  alcohols  aud  upon  the  hexoses,  when  shaktr^ 
with  their  solutions  iu  presence  yf  eaustic  soda.     Witn   the   hexo^r^-^ 
peutabenzoyl  compounds  are  fornied^  and  crystallize  out:   CHO.C^H<s' 
(OH)5  +  5C«E5  C0.C!^CU0.C5Hb(0.C0.C6H5)5  +  5HCL     This  h  J* 
reaction  utilized  for  the  isolation  of  hexoses  and  polyatomic  alcohols* 


AROMATIC   SITLFTJR- DERIVATIVES— SULFONIC    ACtilS 

A  similar  rea^tion^  similarly  utilized,  occurs  with  the  diaraius,  iu 
which  insoluble,  crystalline,  dibenzoyi  compouuds  are  formed:  C2H4- 
(NH2)si+2CeH5.CO.Cl=C2H4(NH.c6.CeH5)2+2HCi. 


I 


AROMATIC   SULFUR-DERIVATIVES— SULFONIC    AQOS. 

Maay  thio-aromatic  compounds  are  kaowu,  as  thiophenol.  C^Hs.' 
SH,  phenyl  salfid,  (CflH5)2S,  and  thio-bcnzoic  acid.  CiiHa.COSH. 

But  the  most  important  of  the  aromatic  compounds  cootaining  sul- 
fur are  the 

Sulfonic  Acids  (p,  372),  monobasic  acids  cootaining  the  group 
SO3H,  formed  by  the  union  of  the  aromatic  hydrocarbon,  or  deriva- 
tive, with  H2SO4  with  elimination  of  OH  from  the  acid  and  H  from 
the  aromatic  compound,  a  process  called  "snlfonation";  CitHii+Us- 
SOi=C«H5.S03H+H20,  The  aromatic  and  polybenzeuic  sulfonic 
acids  are  formed  much  more  readily  than  the  correspondiug  aliphatic 
acids,  and,  being  acid  and  soluble^  are  largely  used  as  d^'cs.  They 
are  usually  produced  by  the  action  of  fuming  H28O4  upon  the  aro- 
matic compound,  with  or  without  the  aid  of  heat. 

The  sulfonic  acids  arc  not  decomposed  by  boiling  with  alkaline  solu- 

t:ions,  but  their  salts,  when  fused  with  caustic  alkalies,  yield  phenols; 

CeH^.SOsK  +  KHO  =  C«H5.0H  +  K.BOa.      Distilled   with   potassium 

ojramd   they   yield   nitrila:    CoHs.SOaX  +  KCN^  CbHsX'N  +  Ka^Oj. 

l^^y  the  action  of  PCI5  they  are  converted  into  their  chlorids,  e,  g, 

t^Hs.SO^Cl,  which  may  be,  in  turn,  converted   into  sulfinic  acids, 

^ulfones,  etc.    They  are  easily  soluble  in  water,  aud  may  be  separated 

^^"om  their  solutions,  as  sodium  salts,  by  the  addition  of  NaCL 

Benzene^nionosolfonic  Acid — CGH5.S0:in — is  formed  by  dissolv* 
•^^^5  benzene  in  weak  fuming  sulfuric  acid  at  a  slightly  elevated  tem- 
t*^rature,  and  diluting  with  H3O.  It  crystallizes  in  extremely  soluble, 
^ ^liquescent  plates  with  1%  Aq.  By  the  action  of  PCls  upon  benzene 
'*^«nosulfonates,  benzene  sulfochlond  is  produced:  CBH5.S0aK+ 
E^C:!I.=C6H5.802€l+KCl+POCl3,  This  is  an  oily  liquid,,  b.  p.  246'', 
^liiuh  is  a  valuable  reagent  for  amins  and  amido  compounds 
vi:*p.380,  412). 

Three  benzene-disulfonic  acids — CM^  ( SOaH  )2 — ortho- ,  meta-  and 
I       ^'^ta-,  are  known,  also  one  benzene-trisulfonic  acid  —  CoHafHOalDa. 
I  Three  tolucnc-sulfonic  acids  — CBH4(CIIa).S03H  — ortho-,  meta- 

^  ^iid  para-,  have  been  obtained.  By  the  action  of  a  mixture  of  ordinary 
H  *^d  fuming  sulfuric  acids  upon  toluene  at  a  temperature  not  exceed- 
^1  ^^g  lOO"^  (212°  FJ,  a  mixture  of  the  ortho-  and  para-  acids  is  pro- 
^^  inred.  When  this  is  treated  with  PCI5,  it  is  converted  into  a  mixture 
^*  «>f  para-  and  ortho  -  toluene  sulfonic  chlorids  —  CflHi.CHa.SOjCL 
^m        The  ortho -chlor id,  when  acted  on  by  dry  ammonia  and  ammonium 


470  MANUAL    OP    CHEMISTRY 

carbonate,  is  converted  into  ortho  -  toluene  sulfamic! — CeHi.CH).- 
SO2NH2.  This  product,  when  oxidized  by  potassium  permanganate, 
is  converted  into  benzoyl-sulfonic  imid — C6H4.CO.SO2NH  —  or  sac- 
charin—  an  odorless,  crystalline  powder,  having  great  sweetening 
power,  its  sweet  taste  being  still  detectable  in  a  dilution  of  1-50,000. 
Sparingly  soluble  in  water  and  in  ether,  readily  in  alcohol.  Its 
solutions  are  acid  in  reaction.  When  heated  with  NasCOs  it  is 
carbonized  and  gives  off  the  odor  of  benzene.  It  is  not  attacked  by 
H2SO4. 

Another  series  of  sulfonic  derivatives  is  obtained  from  the  phenols. 
Among  them  is: 

Ortho  -  phenol  sulfonic  Acid  —  Sozolic  acid — Aseptol — CeH*.- 
(0H)ri)(S03H)(a) — which  is  prepared  by  the  action  of  cold  concentrated 
H2SO4  upon  phenol.  It  is  a  reddish,  syrupy  liquid,  soluble  in  HjO 
in  all  proportions,  has  a  faint  and  not  disagreeable  odor.  It  prevents 
fermentation  and  putrefaction,  and  is  a  non -poisonous,  non-irritant 
antiseptic.  The  salts  of  this  and  the  corresponding  para-  and  meta- 
acids  have  been  used  as  antiseptics  and  insecticides,  under  the  name 
of  sulfo-carbolates,  e,  g.  Sodii  sulfo-carbolas  (U.  S.). 

Phenylsulfuric  Acid— Monophenyl  Sulfate— ^*^|io/SOa— iso- 
meric with  the  phenol  mouosulfonic  acids,  and  corresponding  to 
the  acid  ethyl  sulfuric  ester,  ethylsulfuric  acid  (p.  369),  is  the  acid 
phenyl  sulfuric  ester  which  exists  in  its  salts  in  the  urine,  and  is 
the  type  of  numerous  similar  compounds,  the  "ester  sulfates" 
(p.  728),  which  are  formed  in  the  economy  from  substances  con- 
taining a  phenolic  hydroxy!.  The  potassium  salt  of  the  acid  is 
obtained  by  the  action  of  potassium  pyrosulfate  upon  potassium 
pheuate:  S207K2+C6H5.0K=C6H5.0.S03K+S04K2.  The  free  acid 
decomposes  rapidly. 


NITROGEN-CONTAINING    DERIVATIVES    OF    BENZENE. 

The  nitrogen  derivatives  of  benzene  are  very  numerous,  of  great 
variety  of  structure,  and  include  among  their  number  several  sub- 
stances of  great  industrial  value. 

They  may  be  classified  into  five  principal  groups:  (1)  The  nitro- 
compounds, derived  from  other  benzenic  compdunds  by  substitution 
of  NO2  for  H,  and  the  nitroso-compounds,  containing  the  nitroso 
group,  NO;  (2)  The  hydroxylamin  compounds,  containing  the 
group  — N<^2  ,  and  their  nitroso  derivativ3S;  (3)  the  amido-  and 
imido- compounds,  containing  NH2  and  NH,  the  aromatic  amins, 
amids,  and   amido-acids,  and  their  derivatives;    (4)  the   azo-  and 


NITROGEN  -  CONTAINING    DERIVATIVES    OF    BENZENE 


471 


diazo-compounds  aDd  their  numerous  derivatives,  coutaiuing  the 
grouping  — N^N-^;  (5)  the  hydrazins,  oontaiDiiig  the  groupiug 
^JS — a^,  and   their  nitroso  derivatives. 


I 


NITRO-    AND    NITROSO -COMPOUNDB 

Nitro-benzencs.— These  contain  the  nitro  group  directly  attached 
to  the  carbon  of  the  benzene  ring.  They  are  produced  by  the  action 
of  fuming  HNOa,  or  a  mixture  of  HNO;j  and  H2SO4,  upon  the  hydro- 
carbons: CflHfi+HNOrt^CfiHs.NOo+HsO.  They  are  yellow  liquids, 
sparingly  soluble  in  water.  Their  uiost  important  property  is  their 
ready  reduction,  first  to  hydroxy lamin  compounds:  CflH5.N02+2Ha 
—  CeHs.NH.OH  +  H^O;  and  then  to  amido- compounds:  C0H5.NH,- 
0H+  H2=C«H5.NH>+  HoO  (p.  473). 

Mono-nitro-benzene — Nitro-benzol^Nitro-benzcne— Essence  of 
Mirbane  — '  t\jH5.N02  —  is  obtained  by  the  moderated  action  of  fu- 
ming HNO.'j,  or  of  a  mixture  of  HNOa  and  Il^SO-t  on  benzene. 

It  is  a  yellow,  sweet  liquid,  with  an  odor  of  bitter  almonds;  sp. 
jr.  1,209  at  15°  (59''  P J  ;  boils  at  218"^  (415,4"  FJ;  almost  insol- 
uble in  water;  very  soluble  in  alr^ohol  and  in  ether.  Concentrated 
FI2SO4  dissolves,  and,  when  boiling,  decomposes  it.  Boiled  with 
f timing  HNO3,  it  is  converted  into  dinitro-benzenes*  It  is  converted 
into  a  n  i  1  i  n  by  red  ue  i  n  g  a  ge  n  ts . 

It  has  been  used  in  perfumery  as  arfifieia!  essence  of  bifier  al- 
'»9%^^nds;  but  as  inhalation  of  its  vapor,  even  largely  diluted  with  air, 
<5«i^nses  headache,  drowsiness,  diflRculty  of  respiration,  cardiac  irregu- 
I^r'ity,  loss  of  muscular  power,  convulsions,  aud  coma,  its  use  for 
t:h«t  purpose  is  to  be  condemned.  Taken  internally,  it  is  an  active 
Ix:*i8on. 

Xitro-benzene  may  be  distingulslied   from  oil  of  bitter  almonds 

^  t>«*nzoic  aldehyde)  by  n'jS()4,  whicli  does  not  color  the  fonner;   and 

^y    the  action  of  acetic  acid  and  iron  filings,  which  convert  nitro- 

^^mzf^ne  into  anilin,  whose  presence  is  detected  by  the  reactions  for 

^*»^t  substance  (p.  474). 

Dinitrobenzenes,  —  The  three  dinitrobenzenes   are   produced  by 

^^^*^iling  the  mono-nitro  compound  with  fuming  HNO3.     The  meta- 

^^■"lapound  predomi nates,  and  may  be  separated  by  fractional  erys- 

^llization    from   alcohol.     It  crystallizes   in   plates,   fusible  at   90^ 

^  19^°  pj^  and  is  used  in  the  preparation  of  certain  dyes,  and  of  ex- 

■^^Oaives,  such  as  roburite,  sicherheit,  etc.     The  gases  resulting  from 

'^^t  explosives  are  poisonous. 

Kitrotoluenes.  —  CeHi.CHs^NOs — The  o-  and  p-  compounds  are  pro- 
^Uo^d  together  by  nitration  of  toluene,  and  exist  in  the  commercial 
^^tro- benzene.     They  may  be  separated  by  fractional  distillation,  the 


472 


MANUAL.    OP    CHEMISTRY 


o-  compound  boiliD^  at  218"*  (424.4°  F,),  and  the  p-  at  230°  (446'' 
P.).  By  reduction  they  yield  the  eorrespouding  t^tlnidins,  largely 
used  in  the  eulor  industry. 

Nitro-phcnols  —  Mononitro- phenols  —  CflH4(N02)OH  —  ( 1  —  2) , 
(1  —3)  and  (1—4)  are  formed  hy  the  aetion  of  HNO3  on  C^Hs^OH. 
The  ortho  compound  (1 — 2)  erystallixes  in  large  yellow  ueedlus,  spar- 
ingly soluble,  and  capable  of  distillation  with  steam.  The  meta  and 
para  cornponads  are  both  colorless,  uon- volatile,  (crystalline  bodies. 
ML'thyl  chlorid  converts  nitrophenols  iuto  the  corresponding  nitro* 
anisols»  CttH4X)CH3.N02,  and  ethyl  iodid  intti  nitrophenetols,  CesHi- 
OC-iH^.NO'j,  which  by  reductiou  yield  anisidins  and  phenetidins 
(p  477K  Two  dinitro-phenols,  Cena.OIKNO^)-,.-!^,  and  ('^H^^OH* 
(N0.:)j(3-6.are  obtained  by  the  action  of  stroug  niEric  acid  on  phenol 
or  on  ortho-  or  para*monooitro  phenol.  They  are  both  solid, 
crystalline  substances,  converted  by  further  nitration  into  picric 
acid . 

Trioitro^phenols— €ftH2(N02)30H.— Two  are  known;  (1)  Picric 
acid^^Carbazotic  acid — ^Trinitro^phenic  acid — (NO2)  in  2 — 4 — 6.  It 
is  formed  by  nitration  of  phenol,  or  of  1 — 2 — 4  or  1 — 2 — 6  dinitro- 
phenols,  and  also  by  the  action  of  HNOi  on  indigo,  silk,  wool,  resins, 
etc.  It  crystallizes  in  yellow  plates  or  prisms,  odorless,  intensely  bitter 
(fl-i^po?  ^  bitter) ;  acid  in  i^eaction;  sparingly  soluble  in  water,  very 
soluble  in  alcohol,  ether,  and  benzene;  it  fuses  at  122.5^  (252.5  F.), 
and  may,  if  heated  with  caution,  be  sublimed  unchanged;  but,  if 
heated  suddenly  or  in  quantity,  it  explodes  with  violence.  It  be- 
haves as  a  monobasic  acid,  forming  salts,  which  are  for  the  most  part 
soluble,  yellow,  crystalline*  and  decomposed  with  explosion  when 
heated. 

Picric  acid  colors  silk  and  wool  yellow.  It  is  used  as  a  reagent 
for  the  alkaloids,  with  many  of  which  it  forms  crystal  line  precipitates, 
as  it  also  docs  with  many  other  substances.  It  is  sometimes  added 
to  beer  and  to  other  food  articles,  to  communicate  to  them  either  a 
bitter  taste  or  a  yellow  color.  Its  solutions  give  yellow,  crystalline 
precipitates  with  K  salts;  green  precipitates  with  amnioiuacal  CuSO*; 
and  an  intense  red  color  when  warmed  with  alkaline  KCN  solution. 
It  is  poisononsi 

Nitro-cresols^ — CaHa.CHa.OH.NOs.^The  o-  and  p-  compounds 
are  known.  They  are  readily  converted  into  the'  corresponding  di- 
nitro  compounds,  CaH2.CH3.OH.  (N02)2.  The  2-6  dinitro  compound 
is  used  as  a  dye  in  the  form  of  its  sodium  salt,  under  the  name  17c- 
ioria  orange^  of  saffron  surrogate.     It  is  poisonous. 

The  nitroso-phenots  are  obtained  by  the  action  of  nitrous  acid 
upon  the  phenols;  or  by  the  action  of  hydroxylammoniuni  chlorid 
upon  the  quinones. 


NITEOGEN- CONTAINING    DEBIVATrVES    OF    BENZENE 


473 


p-Nitroso-phenol— Qainoxim— C«IT4.(0IT)„(NO)  4j,   or 
/O 
CftHi<r  I       — (pp*  388,  409),  crystallizes   in    needles,   and   explodes 

fwhen     heated-      Dinitroso  -  rcsorcmol  —  C«H-(on)ij3,(NO)a4  6>  is  a 
brown,  explosive  substance,  used  as  a  green  dye,  solid  grren. 

Nitro-acids,  sueh  as  o-,  m-,  and  p-nitro-benzoic  acids,  CsH*- 
COOH.NOa,  etc.,  are  known,     Tlxey  yield  amido-acids  by  redaction. 


HTBROXYLAMIN    COMPOUNDS. 

Componnds  derived  from  hydroxy  lain  in  by  substitution  of  phenyl 
or  alkyl- phenyls  for  extra*  hydroxy  I  hydrogen  are  formed  as  inter- 
mediate products  of  reduction  of  the  nitro-benzenes  (pp.  471,  483), 

Phenylhydroxylamin  — CflHfMN\  II  —is  an  intermediate  product 

of  reduction  between  nitro-benzene  and  amido-benzene  r  :  Calls. NO2+ 

2H2=C«H6.N(g^  +  H20,  and  G6H5,N02+3H2=C6H5,NH2+2H20,    It 

is  readily  oxidized  to  nitroso -benzene  and  other  products,  and  it  re- 
duces Fehliug's  solution  and  ammoniaeal  AgNOs  solution.  Mineral 
acids   cause   its   intramolecular   rearrangement   to  p-aniido-phenol: 

CftH5*N<^H^=CflH^(On)„,(NH2),4>*      With  nitrous   acid   it   forms   a 

nitroso  derivative:  CeHs.Nx^^^jQ.     It  is  a  crystalline  solid;  f,  p.  81*^; 

and  forms  a  crystalline,  colorless  hydroehlorid. 


AMIDD  -  COMPOUNDS, 

The  amido*benzenes  are  the  counterparts  of  the  aliphatic  primary 
monamins  (p,  377),  They  are  obtained  by  reduction  of  the  corre- 
sponding nitro- compounds.  The  reaction  is,  with  moderate  reduction, 
cot  so  simple  as  is  expressed  by  the  equation:  CoH5.N02+3H:;  = 
C»Hft.NH2+ 2H2O,  but  several  important  intermediate  products  are 
formed  (pp.  471,  483  and  above). 

Anilin  — ArDido-benzene  —  AmMo-henzol — Phenylaniin  — Kymiol 
— Crisiallin  —  Cells-NH^  —  exists  in  small  quantity  in  coal-tar,  and 
is  one  of  the  products  of  the  destructive  distillation  of  indigo.  It  is 
prepared  by  the  reduction  of  nitro- benzene  by  hydrogen:  C6H5.(N02) 
-h 3H2^=  CeHs ( KH2 )  +  2 H2O  ( see  abo v e ) ;  the  h y droge n  be i n g  1  i be ra te d 
in  the  nascent  state  in  contact  with  nitro-benzene  by  the  action  of 
iron  filings  on  acetic  acid. 

Pare  anilin  is  a  colorless  liquid;  has  a  peculiar,  aromatic  odor, 
and  an  acrid,  burning  taste;  sp.  gr,  1.02  at  le""  (60.8''  P) ;  boils  at 
1»*,8^  (364.6''  F.);  crystallizes  at  — 8"*  (17.6°  F.};    soluble  in  31 


474  MANUAL    OF    CHEMISTRY 

parts  of  cold  water,  soluble  in  all  proportions  in  alcohol,  ether, 
carbon  bisulfld,  etc.  When  exposed  to  air  it  turns  brown,  the  color 
of  the  commercial  ^^ aniline  oil,"  and,  finally,  resinifies.  It  is  neu- 
tral in  reaction.  Oxidizing  agents  convert  it  into  rosanilin  (p.  505), 
from  which  blue,  violet,  red,  green,  or  black  derivatives  are  obtained. 
CI,  Br,  and  I  act  upon  it  violently  to  produce  products  of  substitu- 
tion. Concentrated  H2SO4  converts  it,  according  to  the  conditions, 
into  sulfanilic,  or  p-amido  -  benzene  sulfonic  acid,  C6H4(NH2)(s), 
(S03H)u),  or  disulfanilic  acid,  or  anilin  2-4  disulfonic  acid,  CeHa- 
(NH2)(i),(S03H)2(..4).  With  acids  it  unites,  after  the  manner  of 
ammonia,  to  form  salts,  most  of  which  are  crystallizable,  soluble  in 
water,  and  colorless,  although  by  exposure  to  air,  especially  if  moist, 
they  turn  red.  The  sulfate  has  been  used  medicinally.  Potassium 
permanganate  oxidizes  it  to  nitro- benzene.  Heated  with  H2SO4  and 
glycerol  it  produces  quinolin,  and  substituted  quinolins  may  be  ob- 
tained by  a  similar  reaction  from  substituted  anilins. 

Anilin  itself,  when  taken  in  the  liquid  form  or  by  inhalation,  is 
an  active  poison,  producing  symptoms  similar  to  those  caused  by 
nitro -benzene  (p.  471).  Its  salts,  if  pure,  seem  to  have  but  slight 
deleterious  action. 

Anilin  may  be  recognized  by  the  following  reactions:  (1)  With 
a  nitrate  and  H2SO4:  a  red  color;  (2)  cold  H28O4  does  not  color  it 
alone;  on  addition  of  potassium  dichromate,  a  fine  blue  color  is 
produced,  which,  on  dilution  with  water,  passes  to  violet,  and,  if 
not  diluted,  to  black.  (3)  With  calcium  hypochlorite:  a  violet  color; 
(4)  heated  with  cupric  chlorate:  a  black  color;  (5)  heated  with  mer- 
curic chlorid:  a  deep  crimson  color;  (6)  in  very  dilute  solution 
(1:250,000),  anilin  gives  a  rose  color  with  chlorid  of  lime,  followed 
by  ammonium  sulfhydrate. 

Toluidins  —  C6H4(CH3)  (NH2). —  Three  toluidins,  o-,  m-,  and  p-, 
are  known  as  the  superior  homologues  of  anilin.  They  occur  in 
commercial  anilin  and  play  an  important  part  in  the  production  of 
anilin  colors,  (p.  506). 

Xylidins — Amido-xylenes  —  C6H3(CH3)2(NH2). —  Six  compounds 
of  this  compositiqn  are  known:  two  derived  from  ortho-xylene,  three 
from  meta-xylene,  and  one  from  para-xylene.  Five  of  them  exist 
in  commercial  xylidin. 

The  toluidins  and  xylidins  yield  products  of  substitution  and 
addition  similar  to  those  of  anilin. 

Carbodiimids  are  substances  having  the  general  formula  C^jJ^,  in 

which  RR  are  two  univalent  radicals,  usually  belonging  to  the  aromatic 
series.  They  are  prepared  from  the  sulfureids,  by  loss  of  the  ele- 
ments of  carbon  oxysulfid,  COS,  by  the  action  of  heat  or  of  oxj^dants. 


i 


KITROGEN- CONTAINING    DEErV^ATIVES    OF    BENZENE         475 


Derivatives  of  Anilin* — By  the  subsstitutton  of  other  mdieals  or 
elements  for  the  remaiuiog  hydrogen  atoius  of  the  benzene  nut^leus, 
or  for  the  hydrogen  atoms  of  the  araido  group,  NH2,  a  great  number 
of  derivatives,  inehiding  many  isomeres,  are  produced. 

Chloranilins. — Three  monochloranilins  are  known,  of  which  two, 
ortho-  (1 — 2)  and  meta-  (1—3).  are  liquid.  The  other,  para-  (1 — 4). 
is  solid  and  crystalline. 

Four  dichloranilins.  1—2—4,  1— 2--5,  1—3—5,  and  1—3—4, 
are  known,  all  solid  and  crystalline. 

Two  trichloranilins,  1 — ^2 — 4 — 6  and  1 — 2 — 4 — 5,  are  known,  both 
solid  and  crystal  line* 

The  corresponding  bronnanilins  are  also  known;  also  a  tctra- 
bromanilin^  1—2-^3— 4^-6,  and  a  pentabromanilin,  CoiNH^JBrs. 

Of  the  possible  iodanilins,  but  four  have  been  described:  Meta- 
moniodanilin  { 1 — 3  ) ;  paramoniodanilin  (  1 — i  ) ;  the  diiodanilin 
(1—2—4);   and  the  triiodanilin  (1— 2— 4— G). 

Nitranilins.^The  tlu-ce  isomeres,  ortho-,  nneta-,  and  paramooo- 
nitranilios,  C6Hi(NHj)(X02),  are  formed  by  imperfect  reduction  of 
the  dinitro- benzenes. 

Two  dinitranilins,  CflH3{NH2)(N02)2  (1—2—4)  and  {1—2—6), 
are  known. 

A  swingle  trinitranilin,  CeH2(NH2)(N02)3  (1— 2— 4— G),  has  been 
obtaiued  by  the  action  of  alcoholic  ammonia  upon  tlic  ethylic  or 
metuyhc  ester  of  pierie  acid.     It  is  also  called  picramid. 

Anilids,— These  are  compounds  in  which  one  of  the  H  atoms  of 
the  amido  group  has  been  replaced  by  an  acid  radical.  Or  they 
may  also  be  considered  as  am  ids,  whose  remaining  hydrogen  has 
been  more  or  less  i-e placed  by  phenyl »  CqR-,, 

Acetanilid^Antifebrio — Phenyl-acetamid — CeHsCXH.CO.CHa)— 
is  obtained  either  by  heating  together  anilin  and  glacial  acetic 
acid  for  several  hours,  or,  better,  by  the  action  of  acetyl  chlorid 
on  anilin.  It  forms  colorless,  shining,  crystalline  scales;  fuses  at 
112.5''  (234.5°  F.),  and  volatilizes  nnelmnged  at  295^  (563°  F.), 
It  is  sparingly  soluble  in  cold  water,  soluble  in  hot  water  and  in 
alcofaoL 

When  acetanilid  is  heated  with  an  equal  weight  of  ZnCl3i  Hav- 
anilin,  a  colored  substance  having  a  fine  green  fluorescence,  nnd 
soluble  in  warm  dilute  IICl,  is  produced. 

By  herbivorous  aninuiis  acetanilid  is  eliminated  as  para-amido 
phenol,  CflH4(OH)<,>(NH2)«4);  by  caruivorons  animals  partly  in  that 
form,  but  mostly  as  orthoxy-carbanil,  (^(jH4(N.r.0)a)(0H),a}. 

Acetanilid  and  its  derivatives  in  the  urine  respond  to  the  indo- 
phenol  reaction  :  Boiled  a  few  minntes  with  HCl,  a  colorless 
fiolution  is  formed,  which,  on  addition  of  II2O  and  solution  of  phenol 


476 


MANUAL    OF    CHEmSTRY 


in  cliloriuated  lime  sol  a  t  ion »  assumes  a  turbid,  dirty  red  color,  and 
on  addition  of  ammonia  an  indigo- blue  (^olr^r. 

By  tLe  fiirtlier  substitution  of  a  group  (CH3)  in  acetanilid,  methyl- 
acetantlid,  or  exalgine,  CeHs^NCCHiO.CsHsO,  is  produced.  It  is 
formed  by  the  action  of  methyl *iodid  upon  sodium  aeelauilid,  CeHs.- 
NNa.C-iHsO.  It  is  a  crystalline  solid,  sparingly  soluble  in  H^jO, 
readily  in  dilute  alcohoL     Its  odor  is  faintly  aromatic. 

Three  acettolutds,  C6H4\xH^(C2H30)»  ortho-,  meta-,  and  para-, 
are  also  known.  The  para-  and  raeta-  eorapounds  seera  to  be  almost 
inert,  while  the  ortho-  compound  is  highly  poisonous. 

The  "auilin  dyes*^  now  so  extensively  used,  even  those  made  from 
anilin,  are  not  compounds  of  anilin,  but  are  salts  of  bases  formed 
from  it,  themselves  colorless,  called  rosauilins  (see  p.  505), 

Phenylamins  —  Phenyleoediannins,  etc. — Anilin  is  the  simplest 
representative  of  a  large  class  of  substances.  It  may  be  considei*ed 
as  benzene  in  which  H  has  been  replaced  by  NH2,  thus:  CfiHs.NHj. 
Its  superior  homologues,  derivable  from  the  superior  homologues  of 
benzene,  each  have  at  least  three  isoaieres,  ortho-,  meta-,  and  para-, 
according  to  the  orientation  of  the  groups  NH2  and  C»*Hw,+,,  Anilin 
may  also  be  considered  as  ammonia  in  which  H  has  been  replaced 
by    phenyl,   CcHr,,   thus   being   a   primary   monamin   (see    p.    377), 

*g^'|N.     The  remaining  two  H  atoms  may  be  replaced  by  other 

radicals  to  form  an  almost  inlinite  variety  of  secondary  and  tertiary 
phenylamins,  precisely  as  in  the  case  of  the  aliphatic  monamius. 
Possibly  some  of  the  plomaTns  are  phenylamius.    Mydin,  C«HuXO, 

for  example,  is  supposed  to  be  oxyphenyl  ethylamin^  CiiHi<^^fj^  q^  . 

NH2.  It  is  a  powerful  base,  strongly  alkaline,  has  an  araraoniacal 
odor,  is  a  strong  reducing  agent,  is  uon- poisonous,  and  is  produced 
after  continued  putrefaction  at  low  temperatures. 

Again,  it  is  clear  that,  considering  anilin  as  amido- benzene^  the 
substitution  of  NH2  is  not  limited  to  the  introduction  of  one  such 
group.  There  may  be  three  phenylenediamins,  C6n4(NH2)2,  nrtho-, 
meta-,  and  para-,  three  triamido  benzenes  *  C6H3(NH2)3,  etc. 

Meta-phenylenediamin  is  converted  into  triamido  azobenzene, 
Bismark  brown,  by  nitrous  acid,  and  is,  therefore,  used  as  a  test 
for  nitrites  in  water. 

Phenyl  car  by  lamin  —  Phenyl  Isocyanid  —  Isobenzonitril  — 
CeH^.N  i  C — (p,  394)  is  formed  when  chloroform  is  heated  with  anilin 
and  caustic  potash  in  alcoholic  solution  {p.  279).  It  is  a  liquid, 
having  a  most  persistent,  disagreeable  odor.  Nascent  hydrogen  con- 
verts it  into  methyl  anilin.  Heated  to  220°  (428*^  F.),  it  is  converted 
into  its  isomere,  benzonitril,  or  cyanobenzene,  CeHg.CN,  which  is  a 


t 


NITROOEN- CONTAINING    DERIVATU'ES    OF    BENZEKK 


477 


liquid   liaviug  an  odor  of  bitter  almonds j   also  formed  by  distilling 
potassium  benzene  sulfonate  with  potassium  eyauid. 

Amido-phenols  — CtjH4x^ifH2 — Three   are   known,   ortho-,   meta-, 
and  para-»  obtained  by  the  action  of  reducing  agents  upon  the  corre- 
sponding   nitro-eora pounds.     Their    methylic    ethers,    CeRi^^i^H-^ 
are  known  as  anisidins ;  and  their  ethylie  ethers,  CdH4<^j^g'   *    as 

phenettdins* 

By  the  action  of  glacial  acetic  acid  npon  parapheuetidin,  an  aceto- 
derivative,  para-acetophenetidin,  CfiH^(OC2Hr,)ur.(NH.C'iH:iO)u),  is 
formed.  It  is  used  as  au  antipyretic,  under  the  name  phcnacctine, 
and  is  a  colorless,  odorless,  tasteless  powder,  sparingly  soUihle 
in  H2O,  readily  soluble  in  alcohol,  fuses  at  135°,  Its  hot  aqueous 
sohiHon  is  colored  violet,  changing  to  ruby -red,  by  chlorin  water. 
The  corresponding  anisidiu,  para-acetoanisidin»  CfiHilOi'Hs)^,)  (NH.- 
C^aO),4,,  methacetine,  has  also  been  used  as  a  therapeutic  agent. 
It  crystallizes  m  while*  shining,  tasteless,  odorless  scales,  fuses  at 
127°,  sparingly  soluble  in  H2O,  n^adily  soluble  in  alcohoL  It  responds 
to  the  indophenol  reaction  (p.  475). 

Aromatic  acid  amids  are  formed  by  methods  similar  to  those  by 
which  the  aliphatic  araids  are  produced,  and  resemble  them  in  their 
reactions  (p.  400).  Thus  benzamid,  or  benzoyl  amid,  CaHr^.UO.NHo^ 
is  formed  by  the  action  of  benzoyl  ehlorid  upon  ammonia,  OfiHf..CO.- 
€1+NH3=HC1+C6H5.C0.NH2»  as  a  crystalline  solid,  fusible  at  130'', 
or  by  the  action  of  urea  ehlorid  (p.  402)  upon  benzene  in  presence  of 
aluminium  ehlorid:  H2N.CO.Cl+CeHe=CeH5XO.NH2+HCL  Two 
formulae  of  benzamid  are  possible:  the  amid  formula,  C0H5.CO.NH2, 
and  the  imid  formula,  CoHfj.COHrNH.  Derivatives  corresponding  to 
each  are  known. 

and 


Phthalamid— CeHi    (^qJ^ji;',  phthalamic  acid,  CoH*    (x?nh  * 
phthalimid,  C«H4    ^o    NH  are  obtained  from  phthalic  anhydrid* 


The 


last  named  may  be  indirectly  condensed,  through  its  imid  II,  with 
the  fatty  acids  to  produce  compounds  which  serve  as  starting  points 
in  syntheses  of  diamido  fatty  acids  {p.  417). 

The  aromatic  amido-acids  greatly  exceed  the  aliphatic  (p.  411) 
in  number  and  variety.  They  are:  (I)  Amido-phenyl  acids »  which 
may  be  considered  either  as  arorjuitic  acids,  in  which  a  ring  hydro- 
gen atom  {or  atoms)  has  been  reiilaced  by  NH2;  or  as  aliphatic  acids, 
ia  which  amido -phenyl  (CJIi.NllLO'  has  replaced  H  iu  a  hydrocarbon 
group;  (2)  phenyl-amldo  acids,  considered  either  as  aromatic  acids, 
in  which  NH2  replaces  II  in  a  hydroearlion  group  of  a  hiteral  chain, 
or  as  amido -aliphatic  acids,  in  which  phenyl  (CoHs)^  has  been  substi- 


478  MANUAL    OP    CHEMISTRY 

hited  for  H  in  a  hydrocarbon  group;  (3)  anilido-acids — aliphatic 
amido-acids  in  which  phenyl  has  been  substituted  for  H  in  NHj. 
In   this   class  are   included    the   anilids  of    the  dicarboxylic   acids 

(p.  473),  e.  g.,  oxanilic  acid,  0C(^^^'^;  (4)  amic  acids  (p.  401), 

derived  from  the  dicarboxylic  aromatic  acids  by  substitution  of 
NH2  for  OH  in  one  carboxyl  group.  Besides  these  there  are 
amido-acids  referable  to  1  and  3,  in  which  the  radical  benzoyl, 
GeHs.CO,  takes  the  place  of  phenyl,  GeHs.  The  structure  of  these 
several  acids  is  shown  by  the  following  formulae: 

CH2.COOH  CH,.CH(NH2).COOH       NH.CH<^^^^       COOH 


NH2  f  1  r  1  I  iCONHt 


r\ 


KJ 


(1) 

(2) 

(8) 

<4) 

o-Amido-phenyl 
M«tloadd. 

/3  Phenyl,  a  unido- 
propionie  add. 

aAnUido- 
propionic  acid. 

PhthaUunic 
add. 

Those  aromatic  amido-acids  in  which  the  amido  group  is  attached 
to  the  ring  do  not  yield  raonochlor- acids  by  treatment  with  NOCl,  but 
those  in  which  the  NH2  is  in  a  lateral  chain  do,  as  do  also  the  amido- 
acids  of  the  acetic  and  oxalic  series  (p.  413). 

Amido-phenyl  Acids,  of  which  anthranilic,  or  o-amido-benzoic 
acid,  C6H4(COOH)(x)(NH2)(2),  is  the  type,  are  formed  by  reduction 
of  the  corresponding  nitro- benzoic  acids.  Nitrous  acid  converts  them 
into  the  corresponding  oxyacids.  Thus  anthranilic  acid  yields  sali- 
cylic acid.  The  o- acids  exhibit  a  great  tendency  to  the  formation  of 
lactams  (p.  412),  some  of  which  are  indigo  derivatives,  as  oxindole. 

/CHo.COco 
the  lactam  of  o- amido -phenyl  acetic  acid,  C6H4\^       ^l_    ,    and   diox- 


-NH 


(a) 


/CHlOHjCO.x) 
indole,  the  lactam  of  o-amido-mandelic  acid,  C6n4\  I        ,  (p. 

NH:a; 

541).     Isalin,  a  product  of  oxidation  of  indigo,  is  the  lactam  of  o- 

/C0.00(., 
amido-benzoyl-formic    acid,    C6H4\        1^  The   amido-cinnamic 

NH(a) 

acids  are  closely  related  to  quinolin  (p.  543). 

Phenyl-alanin  (p.  414),  is  a  phenyl-amido  acid:  i^-phenyl-a- 
amido-propionic  acid  (formula  above),  which  exists  in  certain  lu- 
pines, and  is  a  product  of  decomposition  of  the  proteins.  Its  corre- 
sponding p-oxyphenyl  derivative  is 

Tyrosin  —  p-Oxyphenyl  alanin  —  (IIO)u)CcH4.CH2.CH(NH2) .- 
COOH — one  of  the  earliest  kno^vn  products  of  protein  decomposition. 


NITBOGEN-CONTAINTNa    DERIVATIVES    OF    BENZENE 


479 


Tyrosin  is  formed  from  proteins,  partieularly  frora  casein,  by  the 
action  of  proteolytic  enzjTnes,  and  during  piUrefaetion,  and  is  also 
formed  from  them  by  boiling  with  HCl  or  H2BO4,  or  by  fusion  with 
KHO,  alwaj'B  accompanied  by  lenein  (p.  414).  It  exists  normally  in 
the  intestine,  and  pathologically  in  the  urine  (q.  v.).  It  has  been 
formed  synthetically,  from  phenyl-acetaldehyde»  C0H5.CH2.CHO,  by 
conversion  into  phenyl *alanin.  CflH5.CH2.CH(NH2)*CUOH  and  p- 
amido'phenyl-a^alanin,  CflH4(NH2)u..CH2.CHNH2.COOH.  It  (crystal- 
lines in  silky  needles,  arranged  iti  stelhite  hundles,  very  sparingly 
^nble  in  cold  water,  soluble  in  150  parts  of  hot  water,  more  soinbl© 
in  the  presence  of  acids  or  of  alkalies,  insoluble  in  alcohol  and  in 
ether.  It  unites  with  acids  and  bases  to  form  salts.  When  heated  it 
tuTUB  brown  and  gives  off  the  odor  of  phenol;  when  heated  to  270*^ 
(518*^  P.),  it  is  decomposed  into  CO2  and  oxyphenylethyl-amin, 
C$H4{OH).CH2.CH2.NH2.  %vluch  sublimes. 

With  HsSOi,  and  slightly  warmed,  it  dissolves  with  a  transient 
red  color;  the  solution,  cooled,  diluted,  neutralized  with  BaCOs,  and 
filtered,  gives  a  violet  color  with   FesCla  (Piria*s  reaction).     When 
moistened  with  HNO:i  and  slowly  evaporated,  it  leaves  a  yellow  resi- 
due, which  forms  a  deep  reddish -yellow  color  with  NallO  (Srherer'a 
reaction).     Heated  with  water  and  a  few  drops  of  Millon's  reagent  it 
^ives  a  red  liquid,  and  forms  a  red  precipitate  (Hofraann^s  reaction). 
fioiled  with  a  mixture  of  1  vol.  formal  in,  45  vols.  H2O,  and  55  vols. 
-HaSOi,  it  gives  a  green  color  (Denig^s).    Il  gives  the  diazo  reaction. 
p-Amidopbcnyl-a-alanin— NH2(,)CflH4.Cri2.CH  ( NH3) .  UOOH— pro- 
diimced  by  reduction  of  p-nitrophenyl-alanin,  is  both  a  pheuyl-amido 
^«:^ci  an  amido-phenyl  acid. 

Anilido  Acids  derived  from  the  monocarboxyiic  acids  are  produced 

^^^^    the  action  of  the   monochlor-acids  upon  anilin,  as  the  aliphatic 

^^■"*=»  ido-acids   are  obtained   from   ammonia  (p.  412).      Thus   mono- 

«^^i  1  <»racetic  acid  and  anilio  yield  anilido -acetic  acid,  or  phenyl  gly- 

^«*^=olU  CH2CLLX>OH+CsHs.NH2=C«H5.NH.CPl2A:oOH  +  HrL 

Hippuric  Acid — Benzoyl^amido-acetic  acid — Benzoyl  glycocoll 

~        ^^sHs.CO.NH.CELiXKiOH — is  similarly  obtained  from   monochior- 

^^^^Tic  acid  and  benzamid:   CIl2CLCOOH+C«H5.CO.NH2=CcHs.CO.- 

^^*i.CH3.C00H+HCL     It  is  also  formed  by  the  action  of  benzoyl 

*^*^lc3rid  upon   glycocoll  in  the  presence  of   sodium   hydroxid  r  CH2- 

vlSI^2).COOH-fCijHfi.CO.Cl=C6n5.CO.Cn2.NH.COOH+HCl.     Hip- 

^^'i^ic  acid  exists  in  the  urine  of  the  herbivora;  and  in  human  urine  in 

^*i^    daily  quantity  of  0.29-2.84  grams,  and  in  larger  amount  when 

^^xoic  acid,  cinnamic  acid  and  other  aromatic  substances  are  taken. 

^^  Crystallizes  in  prisms,  colorless,  odorless,  bitter,  sparingly  soluble 

^^  water,  readily  soluble  in  alcohol,  fuses  at  187°  (368,6"  F.).    When 

heated  with  acids  or  alkalies  it  is  decomposed  into  benzoic  acid  and 


i 


480 


MANUAL    OF    CHEMISTBT 


glyeocolL    Oxidizing  agents  convert  it  into  benzoic  acid,  benzamid 
and  carbon  dioxid.     When  heated  alone  it  gives  off  a  sublimate  of 
benzoic  acid  and  the  odor  of  hydi'ocyanic  acid.    Its  ferric  salt  is  insol 
uble,  and  is  formed  as  a  brown  precipitate  when  Fe2Cl6  is  added  to 
its  solution.    Heated  with  lime  it  forms  benzene  and  ammonia. 

Hippnrie  acid  is  the  type  of  a  class  of  acids  derived  from  the 
aliphatic  monaniidoand  diamido  acids,  and  from  certain  aromatic  aniido 
acids  by  substitntiou  of  cyclic  acidyls  for  one  hydrogen  atom  in  the 
NH2  groups.  Some  of  these  are  synthetic  products,  whose  fonnatiou 
is  utilized  for  the  separation  and  identification  of  amido  acids,  and  are 
prrMlnced  by  the  action  in  alkaline  solution  of  benzoyl  chlorid,  benzoic 
anhydrid,  phenyl  sulfoehloridj  CtsHs-BOiCl,  /3-naphtha!in  sulfochloridt 
CioH7,80:.Cb  4-nitrotoluol— 2-sulfonic  acid,  CeHj.CH^.NOauj.SOaHca., 
etc.,  upon  the  anudo  acids. 

Others,  socli  as  hippuric  acid  itself,  occur  iu  nature:  Omithuric 
Acid  — Dibenzoyl-diamido  valerianic  Acid — CH2(NH.0O.CflH5).CII;n- 
CH2. CH(NH. CO. CoH5).COOH— occurs  in  the  urine  of  hens  fed  with 
beozr>ic  acid.  It  forms  crystals,  f,  p,  182"^,  almost  insoluble  iu  watt^r, 
acid  iu  reaction.  Its  Ba  salt  is  very  soluble  in  water.  Heated  with  IlLl 
it  splits  to  benzoic  acid  and  benzoylornithin,  which  latter,  on  further 
hydrolysis,  splits  to  benzoic  acid  and  ornithin  (p.  417). 

Lysuric  Acid — Dibenzoyl-diamido  caproic  Acid — is  the  corre- 
spoudiug  acid  obtained  synthetically  from  lysin  and  benzoyl  ehlorid. 
It  is  not  known  to  occur  iu  nature.  Its  Ba  salt  forms  crystals,  almost 
insoluble  in  water,  whose  formation  is  utilized  to  separate  lysin  from 
argiuin  (p.  417). 

Anilic  Acids  are  anilido  acids  cotTesponding  to  the  diearboxylic 
acids.  They  may  be  considered  as  being  formed  by  substitution  of 
the  univalent  remainder  of  the  acid  for  H  iu  aniliu,  and  therefore  as 
aniHds  (p,  475) ;  or  by  substitution  of  phenyl  for  H  iu  the  NH2  group 
of  the  amic  acids  {pp.  402,  411).  Thus  oxanilic  scid,  CrtH5.NH.CO.- 
COOH,  corresponds  to  oxalic  acid,  COOH.COOH,  aud  to  oxamic 
acid,  CONH^.COOH. 

Carbanilic  Acid— 0:Cx^^tjjqjj^— the  anilie  acid  corresponding  to 
carbonic  and  carbamic  acids,  and  isomeric  with  phenyl  urethau 
(p.  4n2)^  i'^  not  known  iu  the  free  state.  Its  esters,  how^ever,  ai-e 
known  as  phenyl  urethans.  A  gi-eat  number  of  phcnyl-urea  and 
phenyl^guanidin  derivatives  are  also  known. 

Related  to  the  amido  acids  are  the  hydroxamic  acids  and  th© 
anil  acids. 

Hydroxamic  Acids  are  derivable  from  the  imid  formula  of  benz 
amid  (p.  477)  by  substitution  of  OH  for  H  iu  the  imid  grronp. 
Thus  benzhydroxamlc  acid,  CflHs.C^^Q^  ,  corresponds  to  beDzamid, 


4 
4 


4 


NITROGEN-CONTAINING    DERIVATIVES  OF    BENZENE 


481 


C.^^Qfl.     Botli   H  atoms  Id  the  OH  groups  are  rt^plaeeablts  by 
tyla  to  form  esters.     Amidoxims  (p.  388)  are  derived   from  the 
frdroxamic  acids  by  substitution  of  XHa  for  0H»  e.  g.,  benzeoyl- 
lidoxim,  C(jH5.C<^^Uj  , 

^^  Anil  Acids  are  auilin  derivatives  of  the  ketone -carboxylic  acids 
^B.  347),  formed  by  the  union  of  anilin  and  the  acid,  with  elhiiina- 
^B>n  of  water.  Thus  aiiilin  and  pyrDracemic  acid  yiehl  anil-pyro- 
Plcemic  acid:  C^5.NH2+CH3.CO.boOH--H20+CflH5.NrC(CH3).- 
COOH. 


I 


DIAZO,    DIAZOAMIDO,    AND    A20     COMPOUNDS. 


Diazo  compounds  contain  the  group  * — N:N — ,  united  by  one 
bond  to  an  arouiHtie  group,  and  by  the  other  to  an  acid  radical. 

Diazoaraido  compounds  contain  the  group  — N:N.NH — ,  united  to 
two  aromatic  groups, 
^H    Azo  compounds  contain  the  group  ^ — N:N — .united  to  two  aro- 
^Ratic  hydrocarbon  groups,  or  to  one  aromatic  and  one  aliphatic  hy- 

S'^roearbon  group. 
Diazo  Compounds—are  derivatives  of  diazobenzene,  CbHs-NtNH, 
hich  is,  however,  only  known  in  compounds  in  whieh  the  iniid  li  has 
been  replaced  by  acidyls  or  halogens,  or  of  other  cyclic  com  pounds 
having  the  structure  R.N:N.X,  in  which  R  is  a  cyclie  hyilroearbon 
radical  and  X  an  aeidyl  or  a  halogen.  These  diazo  compounds  are 
very  unstable,  decomposing  explosively  on  slight  elevation  of  tem- 
perature or  by  shock.  They  are  therefore  rarely  isolated  in  their  own 
form  of  crystalline  solids,  but,  on  the  other  hand,  their  instability,  or 
reactivity,  renders  their  formation  as  intermediate  products  very  ser- 
viceable in  the  formation  of  synthetic  products,  and  in  the  manufac- 
ture of  the  "azo  dyes,"  which  include  most  of  the  so-called  **auilin 
colors."  Their  uttlitj^  in  this  regard  depends  upon  the  facility  with 
which  the  diazo  group,  .N:NX  is  displaced  by  other  univalents,  such 
as  OH,  H,  CN,  and  halogens. 

The  diazo  compounds  are  produced  by  the  action  at  low  temperature 
of  HNO2  upon  the  salts  of  the  aromatic  primary  amins.  Thus  anilin 
chlorid  yields  diazobenzene  chlorid:  CaHr^.NHHCl+HNOs^CeH^.Nr - 
NCI+2H2O.  But  if  the  temperature  be  allowed  to  rise  the  action  pro- 
ceeds further,  with  elimination  of  N  nnd  formation  of  a  phenol: 
C«H5.N:NCl+H20=CeH5.0H+N2+HCl;  the  sum  of  the  reactions 
upon  the  am  in  being  then  the  same  as  that  of  HNO2  upon  the  aliphatic 
primary  amins  (p.  380),  i.  e.,  the  substitution  of  OH  for  NH2,  thus 
(;«H5.NH2+HN02=^CfiH5.0H+N2+H20.  This  method  of  formation 
and  decomposition  of  the  fliazo  compounds  is  frequently  utilized  for 
the  introduction  of  hydroxy  1  into  aromatic  molecules*  starting  either 


482  MANUAL    OP    CHEMISTRY 

from  the  hydrocarbou  or  intermediate  forms  of  nitro  or  amido  deriva- 
tives. The  process  is  referred  to  as  diazotizing.  A  similar  decompo- 
sition is  effected  by  simply  boiling  aqaeous  solutions  of  diazo  com- 
pounds: C6H3.N:N.HS04+H20=C6H5.0H+N2+H2S04. 

The  replacement  of  the  diazo  group  by  H,  with  formation  of  the 
hydrocarbon,  is  effected  by  boiling  with  strong  alcohol,  which  u 
oxidized  to  aldehyde:  C6H5.N:N.HS04+CH3.CH20H=C6H6+Ni+ 
H2SO4+CH3.CHO.  The  hydracids  bring  about  the  substitution  of 
halogen  for  the  diazo  group,  with  formation  of  a  monohalid:  GeEU.- 
N:N.HS04+HI=C6H5l  +  N2+H2S04.  A  similar  decomposition  b 
effected  by  CU2CI2,  and  by  PtCU  or  PtBr4.  Diazobenzene  chlorid  in 
presence  of  CuS04  is  converted  by  KCN  into  diazobenzene  cyanid, 
which  then  splits  off  N  to  form  cyanobenzene:  C6H6.N:N.C1+KCN= 
C6H5.N:N.CN+KC1,  and  C6H5.N:N.CN=C6H5.CN+N2. 

Notwithstanding  the  instability  of  the  attachment  of  the  diazo  groap, 
the  diazo  compounds  also  enter  into  reactions  in  which  the  N  is  not  split 
off.  Thus  nascent  hydrogen  reduces  the  diazo  salts  to  phenylhydrazin 
salts  (p.484):  C6H5.N:N.S03K+H2=C6H5.HN.NH.S03K.  Withsub- 
stances  containing  the  grouping — CH2.CO — the  diazo  compounds  react 
in  alkaline  solution  to  form  hydrazoiies  (p.  485),  in  which,  however, 
the  hydrazone  group  replaces  H2,  not  O.  Thus  with  the  malonic  ester: 
C6H5.N:N.C1+H2C:  (COOC2H5)2=C6H5.HN.N:C;  (COOC2H5)a+Ha 

With  the  primary  amins,  whether  aliphatic  or  aromatic,  the  diazo 
compounds  form  diazoamido-  or  disdiazoamido  compounds  (below). 
With  the  phenols  the  diazo  salts  do  not  produce  azoxy  compounds  (p. 
483) ,  but  first  diazo  oxy  compounds :  CeHs.X :  N.HS04+C6H5.0H=C«- 
H5.N :  N.O.C6H5+H2SO4,  which  suffer  atomic  transposition  to  form  oxy- 
azo  compounds:  C6H5.N:N.C6H4.0H,  as  do  the  diazoamido  compounds 
(below). 

Diazoamido  and  Disdiazoamido  Compounds. —  The  diazoamido 
compounds,  containing  the  group  — N:N.NH —  united  to  two  aro- 
matic groups,  are  formed  by  the  action  upon  each  other  of  diazo 
salts  and  primary  or  secondary  arains  in  equal  molecular  proportion. 
Thus  diazoamido  benzene,  C6H5.N:N.NH.C6H5,  is  formed,  as  a  yel- 
low, crystalline,  explosive  solid,  insoluble  in  water,  soluble  in  hot 
alcohol,  by  the  action  of  diazobenzene  nitrate,  or  chlorid,  upon 
anilin:  C6H5.N:NCH-NH2.C6H6  =  C6H5.N:N.NH.C6H5+HC1. 

The  most  notable  property  of  these  substances  is  their  transfor- 
mation, by  intramolecular  rearrangement,  into  the  isomeric  p-azo- 
amido  compounds.  Thus  diazoamido  benzene  becomes  p-azo-amido 
benzene,  C6H5X:NC6H4.(NH2)(4).  This  intramolecular  transposition 
takes  place  slowly  in  the  presence  of  traces  of  anilin  salts,  at  the 
ordinary  temperature. 

The  disdiazoamido  compounds,  containing  the  group  — N:N.NH.- 


NITROGEN -CONTAINING    DERIVATIVES   OF   BENZENE 


483 


N:N^ — ,  are  formed  under  the  same  eoudittoiis  as  the  diazoamido 
eum(Kiunds,  except  that  two  molecules  of  the  diazo  salt  are  taken 
toroueof  tbearain:  2CBH&.N:NCl+NH2,CJB[5=C&H5.N;N.N(CoHfl).- 
N:N,GiH,+2HCl, 

Azo  Compounds* — The  azo  compounds  contain  the  same  grronp, 
— ^N:N — ,  as  the  diazo  compounds,  but  they  differ  from  the  latter  in 
that  the   two  valences  are  both   satisfied   by  hydrocarbon  groups; 
either  both   aromatic,  as   in   azobenzene,    CoHs.NrN.Cens,    or  one 
aromatic  and  one  aliphatic,  as  in  beozene  azo-methane,  CivFU.NiN.- 
CHa.     They  are  "mixed,**  *^ symmetric,**  and  "nnsyni metric,**  accord- 
ing as  they  contain  an  aromatic  and  an  aliphatic  group,  or  two  like 
aromatic  groups,  or  two  unlike  aromatic  groups.     In  designating  the 
orientation  of  substituted  groups  the  — N:N —  attachments  are  con- 
sidered as  occupying  the  (1)  position  in  both  hydrocarbon  gi-oups, 
^B.ud  the  positions  of  substitution  in  one  ring  are  indicated  by  2,  3, 
^tc.,  and  those  in  the  other  by  2',  3\  etc. 

The  azo  compounds  are  formed:  (1)  By  moderate  reduction  of 
m:M  itro-aromatie  compounds  in  alkaliue  solution.  The  reaction  takes 
B>^ace  in  two  stages,  an  azoxy  compound  being  first  formed  and  then 
^^■^rther  reduced.     Thus  nitro-benzene  forms,  fimt  azoxybenzene,  then 

a^obenzene:  2C«H5.N02+3H2=C6H5.N^— IN.CeH^+SHaO,  and  then 

CVHj.N/^N.CfiHr,  +  H'^  ^  CbH5.N : N.CaH^  +  H^O.      The    reduction 
^'^^^dily  progresses  fort  her  ^  and  always  does  so  in  acid  solutions,  with 
formation,  first  of  a  hydrazo  produetfp,  484),  and  finally  an  amido 
^^rivative   (pp,  471,  473).     Thus  azobeuzene  forms,  first,  hydrazo- 
^nzcnc,  or  symmetrical  diphenyl  hydra^^in,  and  then  anilin:  CeHs- 
^'  :X.CnHf>+H2=C«Hr,.NrLNILC«Hr>,    and   CnH^.XH.XH.CflHs+Hs-- 
-C'j^Hs.XHu-     (2)   By  reduction  of  the  azoxy  compounds.     (3)  The 
*Uiido  derivatives  of  the  azo  hydrocarbons  are  technically  manufac- 
tured by   molecular   rearrangement   of   the   diazoamido   compounds 
^P.  482),  or  (4)   by  acting  upon  the  tertiary  anilins,  or  upon  the  m- 
^iiamins,  with  diazo  salts. 

The  azo  compounds  are  much  more  stable  than  the  diazo  com- 
Pounds.  The  hydrocarbons,  such  as  azo  benzene,  CflHs.NrN.CtHs^ 
^^  highly  colored  crystalline  solids,  which  are  not  basic,  and  do  not 
•cl  as  dyes.  They  are  sparingly  soluble  in  water,  readily  solnb?^  in 
alcohol  and  in  ether.  Their  most  important  derivatives  are  the 
*»riido-azo  compounds,  which  are  highly  colored  and  strongly  basic, 
cn«talline  solids,  whose  solutions  have,  however,  no  dyeing  power. 
But  they  combine  readily  with  salt -forming  groups,  notably  to  form 
iDlfonie  acids,  which  constitute  many  of  the  moat  extensively  used 
*aoilin  dyes." 

P'Amido-azobenzene  —  CeH^.N : N.  (CftHi )  (NHa) cii  —  prepared  by 


3 


484 


MANUAL    OF    CHEMISTEY 


the  methods  given  above,  is  the  stariing  point  in  the  nianufacttire  of 
several  yellow,  orange,  and  hrown  "diazo  dyes."  and  of  the  '^inulioci 
dyes,"    It  forms  yellow  needles,  fusing  at  123°  (253.4'^  FJ. 


idily" 


HYDEAZIN    COMPOUNDS. 

The  aromatic  hydrazins  are  derived  from  diamid,  HaX.XHi  (l 
152),  by  substitution  of  hydroearbon  or  other  aromatic  radicals  fo^ 
one  or  more  of  the  hydrog^en  atoms  (p,  390). 

Hydrazo  -  benzene  —  sym.  Diphenyl  -hydrazin  —  C(jHr,.  XH.  NH,  - 
CsH-,— is  obtained  by  moderate  reduction,  as  with  zinc  dust  or  sodinu 
amalgam,  of  azobenzene:    C6H5.N:N.Cttnf.+  HM=C6a^.NH.NH.Ca 
It  forms  colorless  crystals,  having  the  odor  of  camphor,  flisible 
132*^,  insoluble  in  water,  soluble  in  alcohol  and  in  ether.    It  readily 
oxidizes  to  azobenzene.    Strong  reducing  agents  break  it  up  into  twa 
molecules  of  anilin.    It  is  not  basic;  but,  when  treated  with  strong 
acids,  it  suffers  molecular  rearrangement,  with  formation  of  benzid 
or  p,,rdianiido-diphenyl  (p-  502),  NH2u^C8H4.CftH4.XH2u)* 

The  unsynnmetrical  hydrazins  rej<einble  each  other  in  their  prop 
erties  and  methods  of  formation,   but  differ  fnmi   the  symmetric 
compounds,  notably  in  that,  containing  the  — ^NH.NH?  group,  tb« 
are  monacid  Vjases,  forming  salts  corresponding  to  those  of  ammonia/ 

Phenylhydrazin — CflH5.NH.NH2^is  formed  by  reduction  of  the 
diazo  salts,  of  the  diazo-amido  compounds,  or  of  the  nitroso-amins. 
Thus  stannous  chlorid  and  diazobeuzene  elilorid  yield  phenylhydrazin 
hydrochlorid  :  C6H5X;NC1  +  2SnCl2  +  4HC1  ^C6H:.,XH^XHoa  + 
2SnCl^.  Zine  dust  and  acetic  acid  decompose  dinzoamido- benzene 
into  phenylhydrazin  and  anilin  :  CoH5.N:X.XH.CtilI&+2H2^<^oH5,- 
NH.NH2+NH2  Cells. 

Phenylhydrazin  is  a  yellow  oil,  which  crystallizes  at  23^  (73,4**  FJ, 
and  boils  al  242°  (467.6°  FJ  with  partial  decomposition,  or  at  120* 
(248°  F,),  without  decomposition,  under  12  mm.  pressure.  It  M- 
^duces  Fehliug's  solntion,  or  when  boiled  with  CuSOi  it  liberates 
nitrogen  and  forms  benzene.  Sodium  displaces  the  imid  H  to  fora 
a  sodinm  phenylhydrazin:  CsH&.XaN.XHs.  The  alkyl  halids  can 
substitution  of  a  Iky  is  for  both  amid  and  imid  H,  forming  a  and 
pheoylalkyl  hydrazins.  One  of  the  latter,  /3 rnethyl-phenylhydraziii» 
CoHs.XH.XH.CH^,  is  an  intermediate  product  in  the  formation  of 
antipyrin  from  phenylhydrazin.  Heated  to  200°  (392°  Fj  witli 
fuming  HCl,  phenylhydrazin  is  converted  into  p  phenyleoc-diamin: 
CeH^NHNHi—  NH..C6H4.XH2,  M 

Phcnyl-hydrazones  and  Osazones, — ^A  most  important  action  c^B 
phenylhydrazin  is  that  with  aldehydes  and  ketones,  and  with  aldo* 


orm^ 

id^ 


NTTROQEN- CONTAINING    DERIVATIVES    OF    BENZENE 


485 


* 


and  keto- alcohols,  aod  aldehyde  and  ketone  acids  and  their  esters, 
in  which  the  bivalent  remainder  =  N*NH ,06115  takes  the  place  of 
oxygen  in  the  aldehyde  or  ketone  group,  with  the  formation  of 
phenyl-hydrazones  and  osazones,  in  much  the  same  manner  as  the 
aldoxims  and  ketosims  are  formed  from  the  aldehydes  and  ketones 
(pp*  409,  410).  The  formation  of  these  derivatives  is  utilized  to 
ideotify  the  aldehydes  and  ketones  and,  notably ^  the  aldoses  and 
ketoses  (p*  310,  also  "phenylhydi'azin  reaction**). 

The  phenyl -hydrazones  and  osazones  are  formed  by  a  variety  of 
methods,  usually  by  heating  the  aldehj^de  or  ketone  compound  with 
phenylhydrazin  hydroehlorid  in  presence  of  sodium  acetate*  In  the 
formation  of  the  aldchydrazones  and  ketohydrazones  the  reaction 
takes  place  with  elimination  of  water  aceording  to  the  equations: 
CH3.CH2.CHO+H2X.NHXT6H5=CH3XH2.CH:X.NH,C5H5+H20,and 
CH3X^O.CHa+H2N.NH.CoH5=CH3.C:(N.Nn.C«Hr.).Cn3+H20. 

The  osazones  of  the  aldoses  and  ketoses  differ  from  their  hydra- 
zones  in  that  in  the  former  two  :N.NH.CctH5  groups  are  introduced 
iuto  the  sugar  molecule ^  while  the  latter  contain  but  one  such  group. 
The  reaction  of  their  formation  takes  phice  in  three  stages.    Thus 
with  glucose  and  fructose  respectively  (pp,  314,  315):    In  the  first 
stage  the  hydrazoue  is  formed:   CHO.CCHOH)4X^H20H+H2X.NH,- 
Car.=CH(:N.NHX6a0.(CHOH)iX^H2OH+H,O,  and  CHjOHX^O.- 
(CriOH)3X"n,OIT  +  H2N,NHX:«H,  =  CH2OHXU  :  N.NHxyis) .  (CH- 
OH)iX^H20H+ni!0,    In  the  second  stage  the  CH2OH  group  or  the 
CHOH  adjoining  the  position  of  first  substitution  is  dehydrated  to 
^^0  or  CO,  with  formation  of  ammonia  and  anillu:   CH(:N.NHXV 
H5).(CHOH)4.CH20H+H2N,NHXyi5=ClI(:N\NH.aHfi)X^O.(CH- 
OH)3  CHjOH+NHa-f  CUI5.NH2,    and   CH.0HX:N.NHXW5).(CH- 
OH)3X^H20H  +  H2N.NHX^flH,  =  CUOX(:N.NHX^eH&).(CHOH)8.- 
>^B20H+NH3+CVH,v.NH3.    In  the  third  stage  the  second   :N.NH.- 
I  ^^VHs  group  replaces  the  O  in  CO  or  CHO.    Thus,  CH(  :N.NHX«H5)  .- 
CO,(CHOH):^CH20H  +  H2N.NHX^6H>  =  CH(:N.NH.CgH5).C(:N.- 
>^HXijHf,).(CHOH)3CB20H+H20.andCHO.C(:N.NHX;oH5)XCH- 
Oa)3.CH20II  +  H2K.NU.C«Hf.-CH{:N.NHXW5)X>(:N.NHXflH5).- 
<CHOH)3X^H20n+H20. 

Comparison  of  the  above  formnlae  of  the  final  products  from  glu- 
cose and  from  fructose  shows  them  to  be  identical;  and,  indeed, 
iliiccjse  and  fructose  yield  one  and  the  same  osazone^  called  gtticosa- 
*one.  And»  as  glueosazone  on  reduction  yiehls  fnictosamiu :  CH- 
(^^NHXdHf,)X^(rN.NHX\IIrJXCIIOH)3X^H20H  +  3H2  +  H20  =  H2- 
N-CH2X0.(CH0H)3X'H20H+2C6H,'i.Nn2+NH3,  and  this  is  con- 
verted into  fructose  by  nitrous  acid:  H2N.CH2X^OXCHOH)aXH2- 
0U+HNO2=^CH2OH.CO.(CHOH)3X:il2OII  +  N2+  H2O,  we  may  con- 
vert glucose  into  fructose  by  passing  through  the  common  osazone. 


486  MANUAL    OF    CHEMISTBY 

The  phenyl -hydrazones  are  also  utilized  in  the  formation  of  con- 
densed heterocyclic  compounds.     Thus  acetone  phenyl  hydrazone, 

CH3.C  iN.NH.CeHs  CHs.C.NHv 

I  is  converted  into  a  methyl  indole  (p.  640),        II      /• 

CH3  CH    ' 

C6H4,  by  loss  of  NH3. 

Acid  Derivatives  of  Phenylhydrazin. — A  g^^at  number  of  com- 
pounds are  known,  formed  by  the  substitution  of  acid  radicals  for 
the  amid  or  imid  hydrogen  of  phenylhydrazin.  These  oomponnds 
bear  the  same  relation  to  phenylhydrazin  that  the  anilids  bear  to 
anilin,  and  some  of  them  have  been  used  as  antipyretics,  e.  g., 
fi  acetophenyl  -  hydrazid  —  Hydracetin  —  CeHs.NH.NH.CO.CHs- 
formed  as  a  white,  crystalline,  tasteless,  and  odorless  -powder,  spar- 
ingly soluble  in  water,  by  the  action  of  acetyl  chlorid  or  of  acetic 
anhydrid  upon  phenylhydrazin.  It  is  the  active  ingredient  of  an 
antipyretic  called  pyrodin. 


B.     HYDROAROMATIC   COMPOUNDS  WITH  A   SINGLE 

NUCLEUS. 

The  hydroaromatic  compounds  may  be  considered  as  derived  from 
the  benzenic  by  rupture  of  one  or  more  of  the  double  linkages  of  the 
benzene  ring  (p.  435),  by  which  the  valence  of  the  nucleus  is 
changed  from  six  to  eight,  ten  or  twelve. 

HYDROCARBONS. 

Hexahydrobenzenes  —Cyclohexanes—Naphthenes.— These  com- 
pounds, of  which  hexahydrobenzene,  H2C<^ciij'cH^y^CH2,  is  the 
simplest,  and  the  parent  substance  of  the  hydroaromatic  compounds, 
exist  in  Russian  petroleum,  in  coal  tar,  and  in  "rosin -oils."  They 
are  isomeric  with  the  olefins,  from  which  they  may  be  distinguished 
by  the  fact  that  they  do  not  combine  with  bromin. 

Tetrahydrobenzenes  —  Cyclohexenes  — Naphthylenes —  of  which 

the  lowest  term  is  tetrahydrobenzene.  H2C<^ch^*ch2^CH,  exist  in 

rosin -oils. 

Dihydrobenzenes — Cyclohexadienes — of  which  the  first  member 

IS  dihydrobenzenc,  HC^^^qh^.ch/^H,  probably  exist  in  many  of  the 

natural  products  called 

Terpenes. — Most  of  the  volatile,  or  essential  oils,  or  essences,  ob- 
tained by  distillation  of  various  plants  with  steam,  consist  of  hydro- 
carbons having  the  formula  CioHie,  and  most  of  the  camphors  and 


HYDROAROMATIC    HVDROCARBONS 


487 


resins  are  alcoholic  or  ketonift  derivatives  of  these  hydrocarbons.  A 
few  of  the  essential  oils,  having  the  formula  CsHa,  are  known  as 
hemiterpcncSi  or  olefin  terpenes*  and  are  ttnsatnrated  aliphatic 
compounds  (p.  425),  Some  of  the  aromatic  terpeiies  also  are  poly- 
meres,  having  the  formulae  xCCsHa).  Although  the  constitution  of 
the  aromatic  terpenes  is  not  completely  established^  they  are  hydro- 
aromatic  hydrocarbons  of  which  th©  camphors  are  alcohols  or  ketones. 
The  terpenes  form  benzenic  compounds  by  oxidation.  With  the 
halogens  they  form  addition  products,  which  not  ouly  serve  for  their 
classification,  but  also  for  their  conversion  into  alcohol -camphors. 
With  nitrosyl  chlorid,  NOCl,  they  form  well-defined  nitroso-chlorids, 
.as  dipentcne  nitroso-chiorid,  CioHifl(NO)Cl,  which  serve  for  their 
identification,  and  for  the  preparation  of  basic  and  other  derivatives. 
The  true  terpenes  and  their  derivatives  are  arranged  in  two 
<;lasses:    (1)  The  Terpan  grmtp,  and  (2)  the  Campkan  group. 

The  terpans    are  capable  of  taking  on  four  bromin  atoms,  and 
therefore  have  two  double  linkages*     It  is  assumed  that  in  them  the 
^n  carbon  atoms  are  arranged  in  a  hexacarbon  ring,  with  two  lateral 
\  2     3  8 

■  7    i/-^.4    a/ 

<2hains  in  the  p-  position  to  each  other,  thusr    C— C<^        ^C— C^  , 

c-c  c 

6     d  ID 

«ind  that  two  of  the  ten  bonds  are  double.  The  hydrocarbons  are, 
therefore,  dihydrocymcnes  (p.  442).  The  carbon  atoms  ai'e  num- 
bered as  above  to  indicate  the  positions  of  the  double  linkages,  which 
vary  in  the  dilferent  isonun-es*  The  positions  of  double  linkage  are 
marked  by  the  Greek  capital  ^,  followed  by  the  numbers  of  tlie  carbon 
atoms  from  which  the  attachment  proceeds: 

Limoncne— A,,e>Dihydrocymene— CH3.C^^^J^*)C*^ 

(probably)  exists  in  three  optical  isomeres  :  d-limonene;  b.  p, 
175**  (347°  FJ;  Md=  + 106.8°;  a  liquid  having  the  odor  of 
lemons,  existing  in  many  essential  oils,  such  as  those  of  orange, 
bergamot*  dill,  etc. :  Mimoncnc;  b.  p.  ITS'"  {347''  F.) ;  [«(]o=  —105°; 
occurs  in  the  oils  of  peppermint,  fir  and  pine  needles.  [d+l]-limon- 
cne,  dipentcne,  or  cinene;  b.  p.  175°  (347°  F.);  occurs  in  oil  of 
wormseed,  and  is  produced  by  the  action  of  a  heat  of  25O°-30O° 
upon  limonenes,  pineno  and  camphene,  and  therefore  exists  in  tur- 
pentine oil  produced  at  high  temperatures,  such  as  the  Russian  and 
Swedish,  The  limonenes  are  liquids  having  the  odor  of  lemons, 
and  combining  with  bromin  to  produce  solid  tetrabromids  having 
the  same  optical  action  as  the  parent  hydrocarbons. 

Other  terpaos  are:   Tcrpinolenc;  f.  p.  75°;  formed  when  terpin 
hydrate,  terpineol,  or  cineol  is  heated  with  dilate  HaiiO*,  or  by  the 


488 


iJUAL    OF    CHEMISTRY 


I 


action  of  the  concentrated  acid  on  pinene.  Sylvestrene;  b.  p,  176** 
[a]D= +66.32"^;  occurs  in  Swedish  and  Russian  turpentine.  Ter* 
pinene;  b,  p,  180°;  is  formed  when  dipentene,  terpin,  phellandrene, 
terpineol  or  cineol  is  heated  for  some  time  with  dilute  alcoholic 
H2SO4,  or  by  the  action  of  the  concentrated  acid  on  pinene,  or  by 
the  action  of  formic  acid  on  linalool  (p.  427) <  It  is  not  converted 
into  other  terpens  by  acids,  and  does  not  yield  a  bromin  derivative, 
but  forms  a  nitroso-cklorid.  Phellandrene ;  b.  p.  170'';  exists  in  d- 
and  1 -modifications.  It  has  the  same  negative  qualities  as  ter^fl 
pinene.  Mcnthcnc,  CioHi«,  is  a  hydroterpan,  formed  by  acting  upon 
potassium  pheuale  with  menthyl  chlorid;   b.p.  167°, 

The  members  of  the  camphan  group  are  capable  of  taking  up 
two   bromin  atomSi  and   are  considered   as   probably  containing   a 

dihydrobenzene   ring  with   a  —  c—    group   linking  the  p-positiona 

internally,  as  in  the  probable  formula  of 

/CH.  -  Clh\ 

Caniphene  —  CH3—C-(CH3.C.CH3)-CH— which  is  a  solid;   f.  p^ 
\CH  =  Cfl  /  »  K-( 

43°  (109.4^F.)j  b.  p.  160^  (320°  P.);   nD=1.45ol4  (54^);  (p.  M)i 

known    in   d-,   l-,   and   [d+l]    modifications*     It    exists   in   Ceylon 

citronella  oil,  and  is  produced  by  the  action  of  dehydrating  agentoA 

upon  its  alcohol,  Borneo-camphor  (p.  491).    It  forms  a  dibroinid.       ^ 

Pinene — C10H16 — is  the  principle  constituent  of  oil,  or  essence  of 
turpentine,  and  exiiits  also  in  many  other  essential  oils.  It  is  a  color- 
less liquid;  b.  p,  155°;  sp.  gr.  0.858  (20°);  no^L46553  (21°).  It 
exists  in  three  optical  isomeres:  d-pincne;  [a]D=17^;  predominates 
in  American  oil  of  tm-pendne;  l-piiienc;  [«]r>^  —  40.3'';  in  the 
French  oil.  Pinene  combines  with  broniiu  to  form  a  dibroinid;  it, 
therefore,  contains  one  double  linkage.  Wlieu  dry  HCI  gas  is  passed 
through  pinene,  well  cooled,  a  white,  crystalliTje  substance,  fusing  at 
125°,  and  having  the  odor  of  camphor^  separates.  This  is  d-pinene 
hydrochloride  C10H17CI,  or  "artificial  camplior."  H 

Turpentine  is  a  yellowish -white^  semi-solid  substance,  having  bl^ 
balsamic  odor,  which  exudes  from  incisions   in  the  bark  of   Finns 
pubtstris,  P.  tmin,  and  other  Coniferm,  and  which  may  be  taken  as 
the  type  of  a  nnmber  of  other  similar  products.     These  substances,  ^ 
when  distilled  with  steam,  yield  two  products,  one  a  solid,  yellow  oiS 
brown  residue,  a  stearoptene,  sneh  as  rosin  or  colophany ;  the  other 
a  volatile,  oily  liquid,  an  eleoptene,  such  as  oil,  or  essence,  of  tur- 
pentine.    Oil  of  turpentine  is  insoluble  in  water,  mixes  with  alcohol 
and  with  ether,  and  dissolves  phosphorus,  snlfur  and  cnoutchoucj 
When  exposed  to  the  air  it  is  oxidized  to  gummy,  aldehydal  products,^ 
which  finally  harden,  hence   its  use  as  a  drier  in  the  manufacture 
of  paints  and  varnishes.     On  contact  with  HNOa,  its  oxidation  i&j 


HYDROAROMATIC    ALCOHOLS 


489 


«<>     Tiolent  as  to  cause  ig^nition.   HgSOi  also  acts  upon  it  energetically » 

fitzh  formation  of  a  number  of  polymeres. 
Hydroterpenes  are  naphthenes  (p.  ^SS)  obtained  by  decomposi- 
^Ob  of  certain  natural  alcohol -camphors.     Thus  hexahydrocymene, 
iCXH<;^gj;gg=>CH.CH(gg;,  18  derived  from  menthol  (p,  490), 

HYBROAROMATIC    ALCOHOLS. 

The  hydroaroniatic  alcohols  are,  for  the  most  part^  "ring  alco- 
hols/' and  contain  either  CHOH  or  COH»  as  a  part  of  the  ring» 
although  in  some,  as  in  some  of  the  terpan  alcohols  (p.  490),  the 
alcoholic  group,  which  may  then  also  be  CH2OH,  is  contained  in  the 
lateral  chain.  These  alcohols  may  be  obtained  by  reduction  of  the 
corresponding  ketones  {p,  491),  or  of  other  aromatic  orhydruaromatie 
compounds.  Several  of  them,  such  as  quercite,  iuosite  and  some  of 
the  camphors,  are  natural  product s» 

Quinite  —  HOHC  (^cH^'cS)  <^HOH  -  ^Tid    phloroglucite  — 

H0HC\no^V.oQjryCH2  — are    rednctiou    products   of    the  phenols, 


XCfla.CHOH/^ 

quinol,  HOC^^JJ;^g^COH,  and  phlorogluciu,  HOC^eH^COHX'^ 
respectively  (p,  449), 

Quercite  — H2C<^eHon:cHOH/^^  pentatomic  alcohol,  ob- 

tained from  acorns.  It  is  a  sugar- like  substance,  but  is  not  affected 
by  alkalies,  does  not  ferment,  and  does  not  reduce  Fehling's  solution. 
P.p.  235^    Mo=+Ma6°. 

Inosite  —  CBH5(0H)fl^  metameric,  though  not  related,  to  the 
glucoses,  is  a  ht*xatoinic  aletihul,  whirli  exists  in  three  optical 
modifications.  The  inactive  modification  exists  in  the  liquid  of 
muscular  tissue,  in  the  lungs,  kidneys,  liver,  spleen,  brain  and  blood; 
in  traces  in  normal  nrine,  and  increased  in  Bright's  disease,  in  dia- 
betes, and  after  the  use  of  drastics  in  uraemia;  in  the  contents  of 
hydatid  cysts;  in  beans  and  peas,  and  in  certain  other  seeds  and 
leaves.  It  crystallizes  in  needles,  usually  arranged  in  cauliflower- like 
masses,  has  a  sweet  taste,  is  readily  soluble  iu  water,  sparingly  soluble 
in  alcohol,  insoluble  in  absolute  alcohol  and  in  ether.  It  does  not 
ferment,  is  not  colored  by  alkalies,  and  does  not  reduce  Fehling's 
solution.  Wlien  heated  to  170''  (338°  F.)  with  HI,  it  is  decomposed 
into  phenol,  diiodophenol  and  benzene.  When  treated  with  HNO:<, 
evaporated  to  near  dryness,  the  residue  moistened  with  NH4HO  and 
CaCb,  and  again  evaporated,  a  rose -red  residue  is  left  (Scherer's 
reaction).  Mercuric  nitrate  produces  in  solutions  of  inosite  a  yellow 
precipitate,  which,  on  cautious  heating,  turns  red.  The  color  dis- 
appears on  cooling  and  reappears  on  heating  (Gallois'  reaction ). 


490 


MANUAL   OP   CHEMISTKY 


Dambonite,  a  supposed  glucositl  (ji.  4^5)  obtamed  from  an 
Afrieati  L-aouk^houe,   is  the  dimethyl  ether  of  Wnosite  (danibose). 

Tlie  terpan  alcohols  are  derivatives  of  hexahydrocymene,  or 
menthan  (p,  489),  H3CXH(^;v^;;^J{;)CH.CH<^^^^  CioH^o;  or  oj 
menthene,  CioHig;  or  of  menthadiene,  CioHio;  diflfericg  from  meatbaa* 
by  the  iDtroduetion  of  one  and  two  double  bonds  respectively.  They 
are  monaeid,  diacid^  etc.»  aecording  to  the  number  of  hydroxy  Is  sub- 
stituted for  hydrogen*  Among  them  are  menthol  and  terpin  and  its 
hydrate. 

Menthol  —  Oxyhexahydrocymene  —  HaC.CH<(^H!xu!^^^GH.. 

CH<^Qjj^-^is  a  monaeid  menthan  alcohol.     It  is  the  chief  constituent 

of  oil  of  peppermint.  It  crystallizes  in  prisms^  fusible  at  42^  (107.6° 
FJ,  sparingly  soluble  in  water,  i*eadily  soluble  in  alcohol,  ether 
and  carbon  bisulfid,  atid  iu  acids.  Corresponding  to  it  are  a  series  of 
menthyl  esters. 

Terpin s.^ — There  are  two  diaeid  menthan  alcohols,  in  which  the 
hydroxyls  occupy  the  1,8  positions  (p.  487).  The  formula  of  cis- 
terpin,  the   parent   substance   of   terpin    hydrate   and   of   cineoU 


r 

I 


DOW  considered   as   being 


>C<  >C<    /OH 

HO^     VHj.CH/     \c=\CH3)a 


while   ia^ 


trans-terpin  the  positions  of  the  CH3  and  OH  attached  to  C(l)  are 
reversed,  Cis-terpin  is  obtained  by  dehydration  of  terpin  hydrate, 
and  also  from  [d+l]-limonene  dihydrochlorid  (p.  487).  It  is  crys- 
talline, fuses  at  104°  (219.2°  F.),  and  boils  at  258"^  (496,4°  FJ. 
It  absorbs  water  eagerlv  to  form  terpin  hydrate.  Gaseous  HCl,  or 
PCI3,  converts  it  into  [d+l]-limouene  hydrochloride 

Terpin  Hydrate  — CMHig(0H)2+ H2O  —  is  formed  when  oil  of 
turpentine  remains  long  iu  contact  with  water,  more  rapidly  in 
presence  of  alcohol  and  dilute  HNO3;  also,  similarly,  from  pinene 
and  from  limonene.  It  forms  rhombic  crystals*  fusible  at  117*^ 
(242,6°  FJ,  with  loss  of  H2O  and  conversion,  slowly,  into  terpin. 
It  is  easily  soluble  in  alcohol,  sparingly  soluble  in  water,  chloroform 
and  ether.     It  is  used  as  an  expectorant, 

Cineol  —  Eucalyptol  —  Ciania(0H)2  —  another  diaeid  menthan  al- 
cohol, is  obtained  from  the  leaves  of  Enmlyptns  globulus,  and  also 
exists  in  wormseed  oil  {Oleum  eimr)  aud  in  other  volatile  oils.  It  is 
a  colorless  oil,  having  a  camphor-like  odor;  sp.  gr,  0.93  at  15^; 
b.  p,  176^;  nD  =  1.4559;  soluble  in  alcohol,  sparingly  soluble  in 
water.  Dry  HCl  gas  passed  through  its  petroleum  ether  solution 
separates  white  scales  ok'  cucalypteol,  CioHig.2HC1,  which  is  decom- 
posed by  water  with  regeneration  of  cnienl. 

Tcrpineols  are  monacid  menthene  alcohols.    The  ^1,  {OH)<i)ter- 


1 


4 


^ 


HYDROAROilATIC    KETONES    AND    ACIDS 


491 


pineol  is  formed  by  removal  of  2H2O  from  terpiu  hydrate.  It  is  a 
solid;  f,  p.  35°  (95""  F.).  When  boiled  with  dilute  acida  it  forms 
carvacrol  (p.  447),  and  the  ketone,  carvoiie  (below).  It  forms  dipen- 
tene  when  heated  with  KH8O4. 

Borncol  —  Camphol  —  Borneo  Camphor  —  CioHihO  —  a  monacid 
alcohol,  is  the  best  known  of  the  camphan  alcohols.  It  exists  in 
three  optical  modifications j  the  d-bomeol  being  the  one  usually  met 
with,  and  obtained  from  Drt/obalanops  camphora.  The  d-  and  1- 
raodifications  are  both  formed  by  hydrogen ation  of  laurel  camphor. 
It  forms  small,  friable  crystals;  has  an  odor  recalling  those  of  laurel 
camphor  and  of  pepper,  and  a  hot  taste;  is  insoluble  in  water,  readily 
soluble  in  aleohol,  ether,  and  acetic  acid;  fuses  at  203^  (397.4^  P.); 
hoih  at  212*'  (413.6'*  P.) .  It  is  oxidized  to  laurel  camphor  by  HXO3. 
Heated  with  KH804»  it  is  decomposed  into  campheue  (p.  488)  and 
H2O. 

HYDROAROMATIC  KETONES  AND  ACIDS. 

The  hydroaromatic  ketones  are  "ring  ketones, ^^  the  CO  group 
forming  a  part  of  the  ring.  They  are  formed:  (1)  by  reduction  of 
the  corresponding  aromatic  phenols;  (2)  by  oxidation  of  the  secon- 
dary ring-alcohols;  (3)  by  condensation  of  the  esters  of  the  aliphatic 
ketone  acids  (p.  347),  or  of  the  ketones.  The  terpan  and  camphan 
ketones  exist  in  nature.  The  ketones  form  ketoxims  with  hydroxyl- 
amin  (p.  409),  and  hydrazones  with  phenyl  bydrazin  (p.  485),  which 
serve  for  their  identification. 

Pimelin'kctonc-H:H2<^^^H';cH2/^  ^^^  simplest  of  the  hy- 

droaromatic  ketones.     It  is  an  oil,  having  the  odor  of  peppermint;  b, 
p.  155^  ;   formed  by  electrolytic  reduction  of  phenol;   by  oxidation  of 

bcxahydrophenol,  CHax^oHaXHs/CHOH;  or  by  distUlation  of  cal- 

einm  pimelate,  CH2<^cS:ch!:co'/^^  ^P-  ^^^'"    Its«>^™  f«^ses  at  88°, 

The  terpan  ketones,  or  ketohydro-p-cymenes,  are  formed  by 
oxidation  of  the  corresponding  secondary  alcohols  (p.  489). 

Mcnthone^ — CioHigO — (CO-3) — is  a  ketomenthan,  existing  in  oil 
of  peppermint.  It  is  known  in  two  optical  isomeres  :  1-menthone  is 
formed  by  oxidizing  menthol,  and  is  converted  into  d-metithone  by 
contact  with  H2HO4.  B.  p.  206"^  ;  Wd=  —28°  and  +28^  l-Men- 
thoxim  fuses  at  59°. 

Thujone^Tanacetonc — and  Pulcgone — CioHiaO,  are  ketomen- 
thenes,  the  former,  b,  p.  200°,  existing  in  tansy  and  thuja  oils;  the 
latter,  b.  p.  221°,  in  "polei-oils." 

Carvone — Carvol— CioHhO^is  a  ketonncnthadiene,  known  in 
tliree  optical  isomeres,  which  boil  at  225°.     d-Carvol  exists  in  cumin 


492 


MANUAL    OF    CHEMISTRY 


and  dill  oils;  [a]D=+62*'.    Heattfd  with  KHO,  it  is  converted  into 

its  isomere  earvacrol  (p.  447),  The  three  carvoxims  are  formed 
either  by  the  action  of  hydroxy  lamia  upon  the  corresponding  car- 
vones»  or  by  the  action  of  boiling  KHO  upon  the  three  limonene 
nitrosoehlorides  (p>  487), 

d-Campbor — Common  camphor — Laurel  camphor — Japan  cam- 
phor— CiaHiaO — is  the  most  important  of  the  camphan  ketones.  It 
in  obtained  from  the  camphor  tree  {lAtitrus  camphora) ^  and  is  formed 
artificially  by  oxidation  of  borneol  or  of  camphene.  It  forms  trans- 
lucent, friable  crystals;  hot  and  bitter  in  tast€»  ai*omatic;  sparingly 
soluble  in  water,  quite  soluble  in  acetic  acid,  methylic  and  ethylic 
alcohols,  and  the  oils;  f.  p.  175"^  (347°  P.);  b,  p.  204^  (399.2''  F.); 
sp*  gr,  0.985;  sublimes  at  all  temperatures;  Md^^  +44.22. 

It  ignites  readily,  and  burns  with  a  luminous  flame.  Cold  HNO3 
dissolves  it,  and  H2O  precipitates  it  unchanged  from  the  solution. 
Hot  HNO3,  or  potassium  permanganate,  oxidizes  it  to  d -camphoric 
acid.  Distilled  with  P2O5  it  yields  eymene,  CioHu.  Reducing  agents 
convert  it  into  borneol.  Heated  w^ith  iodin,  it  is  converted  into  ear- 
vacrol (p.  447).  Bromin  unites  w^ith  it  to  form  ruby -red  er>nstals  of 
an  unstable  compound,  CioHi40Br2,  which,  when  heated,  fuse  and 
give  off  HBr^  leaving  an  amber -colored  residue,  which,  on  recrystal- 
lization  from  boiling  alcohol,  leaves  long,  hai'd,  rectangulai*  crystals 
of  monobromo-camphor,  CioHisOBr;  f .  p.  76°;  soluble  in  alcohol 
and  in  ether. 

l"Camphor  is  obtained   from  the  oil  of  Matriraria  jjostkinm 
[alo^   ^44.22°.      [d+ l]-Camphor  exists  in  the  essential  oils 
rosemary,  sage,  lavender  and  origanum,  or  is  formed  by  mixing  d- 
and  1-  camphors,  or  by  oxidation  of   [d+l] -borneol,  or  of   [d+1]- 
camphene.    F,  p.  179°, 

Hydroaromatic  Carboxylic  Acids.  —  A  great  number  of  these 
acids  are  known,  some  pure  acids,  others  oxy-  or  ketonic  acids,  con- 
taining from  one  to  six  carboxyl  groups  ^  and  hexahydro-^  tetrahydro- 
and  dihydro-.     The  most  important  are: 

Quinic  Acid  —  Hexahydro-tetraoxybenzoic  Acid  —  CcHt(OH)4.- 
COOH  —  which  exists,  combined  with  the  alkaloids,  in  cinchona 
barks,  also  in  coffee  beans  and  in  other  plants.  It  forms  hanl, 
transparent  prisms,  soluble  in  water  and  in  alcohol;  fuses  at  160*^; 
Iffivogyrous.  On  distillation,  it  yields  phenol,  hydroquiool,  benzoic 
acid  and  salicylic  aldehyde.    Hydr iodic  acid  reduces  it  to  benzoic  acid. 

Tercbic  Acid  —  C7H10O4 — f.  p.  175°;  and  Terpenylic  Acid  — 
CeHi^Oi  — f*  p.  90*^,  are  oxidation  products  of  oil  of  turpentine, 
obtained,  the  former  with  HNO3,  the  latter  with  chromic  acid  mixture. 

Camphoric  Acids— C«Hn(CO0H)2.— The  d-,  1-,  and  [d+l]-acids 
ai'c  know^u.     d-Camphoric  acid  is  produced  by  oxidizing  common 


»ho^i 


COMPOUNDS  WITH    CONDENSED    NUCLEI  493 

cHjamphor  by  heating  with  HNO3.  It  forms  colorless,  odorless 
needles,  soluble  in  alcohol,  ether  and  boiling  water;  f.  p.  187®; 
[a]o=  +49.7°.  By  further  oxidation  it  yields  camphoronic  acid, 
or  trimethyl-tricarballylic  acid  (p.  338). 

Resins — are  generally  the  products  of  oxidation  of  the  hydro- 
carbons allied  to  pinene;  are  amorphous  (rarely  crystalline);  insol- 
uble in  water;  soluble  in  alcohol,  ether,  and  essences.  Many  of  them 
contain  acids. 

They  may  be  divided  into  several  groups,  according  to  the  nature 
of  their  constituents:  (1)  Balsams,  which  are  usually  soft  or  liquid, 
and  are  distinguished  by  containing  free  cinnamic  or  benzoic  acid, 
e.  g.,  benzoin,  liquidambar,  Peru  balsam,  styrax,  balsam  tolu;  (2) 
oleo-resins  consist  of  a  true  resin  mixed  with  an  oil,  e.  g..  Burgundy 
and  Canada  pitch,  Mecca  balsam,  and  the  resins  of  capsicum,  copaiba, 
eubebs,  elemi,  lupulin;  (3)  gum-resins,  mixtures  of  true  resins  and 
gums,  e.  g.,  aloes,  ammoniac,  asafcediia,  euphorbivm,  galbanum, 
guaiac,  myrrh,  olibanum,  scammony;  (4)  true  resins,  hard  substances 
containing  neither  essences,  gums  nor  aromatic  acids,  e.  g.,  resin, 
copal,  dammar,  jalap,  lac,  sandarac;  (5)  fossil  resins,  e.  g.,  amber ^ 
asphalt,  osocerite. 


C.     COMPOUNDS   WITH  CONDENSED   NUCLEI. 

These  compounds  contain  two  or  more  benzene  rings,  or  one  or 
more  benzene  rings  and  a  pentacarbocyclic  ring,  fused  together  in 
such  manner  that  the  adjacent  rings  have  two  carbon  atoms  in  com- 
mon. The  parent  hydrocarbons  of  these  compounds  are  :  indene, 
fluorene,  naphthalene,  anthracene,  phenanthrene,  chrysene,  and 
picene 


H 

H 

H 

H         H 

C 

C 

C 

C          C 

^  \ 

/  \             /  \ 

^  \  /  \ 

HC         C CH 

HC          C C 

CH 

HC          C          CH 

1           II         II 
HC         C        CH 

1           II         II 
HC          C        C 

I 
CH 

1           II            1 
HC          C          CH 

\  /  \  / 

\  /  \/  \  ^ 

\/   \^ 

C         C 

C         C 

C 

c       c 

H         Ha 

H        H2 

H 

H         H 

Indene. 

Fluorene 

Naphthalene. 

H           H          H 

H 

H 

H   H 

C           C           C 

C= 

=C 

C=C 

^  \    / 

\    /% 

/ 

\ 

^         X., 

HC           C 

C          CH 

HC 

c 

-0               CH 

1             II 

II           1 

\ 

^ 

"^  y 

HC          C 

C          CH 

C- 

_'"' 

c-c 

%/   \ 

/    \  ^ 

H 

"  \ 

/      H 

c       c 

J          C 

C 

=c 

H         I 

I         H 

H 

H 

Anthi 

aeene. 

PhenAntbrene. 

494  MANUAL   OP    CHEMI8TBY 

The  derivatives  of  these  hydrocarbons  are  similar  in  their  general 
properties  to  the  benzene  derivatives,  with  some  differences  in  orien- 
tation. Chrysene,  C18H12,  and  picene,  C22HU,  are  naphthalene-phen- 
anthrenes  (p.  496).  Most  of  these  hydrocarbons  form  crystalline 
addition  products  with  picric  acid. 


CONDENSED  HYDROCARBONS. 

These  hydrocarbons  accompany  benzene  in  coal-tar.  Naphtha- 
lene and  anthracene  are  obtained  from  this  source  industrially. 

Indene — C9H8 — (constitution,  p.  493) — exists  in  the  fraction  of 
coal-tar,  distilling  between  176°  and  182°.  It  has  also  been  obtained 
synthetically.  Indene  derivatives  can  also  be  produced  from  naph- 
thalene derivatives,  one  benzene  ring  being  converted  into  a  penta- 
carbocyclic  ring  (see  formulsB,  p.  493).  Indene  is  the  hydrocarbon 
corresponding  to  indole,  which  contains  NH  in  place  of  the  CH2 
group  (p.  538).  It  is  an  oil;  b.  p.  17S°;  sp.  gr.  1.04  at  15°.  At  a  red 
heat  two  molecules  of  indene  unite,  with  loss  of  4H,  to  form  chrysene 
(p.  496).  By  reduction  indene  is  converted  into  hydrindene,  C6H4: 
(CH2)3;  an  oil;  b.  p.  177°. 

Fluorene  —  Diphenylene  Methane  —  C13H10  —  exists  in  the  frac- 
tion of  distillation  of  heavy  coal-tar  oils,  distilling  between  300° 
and  320°.  It  is  also  formed  by  the  action  of  red  heat  upon  diphenyl 
methane  (C6H5)2CH2,  and  from  other  diphenyl  and  phenanthrene 
derivatives.  It  crystallizes  in  colorless  leaflets,  having  a  violet  fluor- 
escence; f.  p.  113°;  b.  p.  295°;  very  soluble  in  ether  and  in  benzene, 
sparingly  soluble  in  alcohol.  Its  picric  acid  compound  forms  red 
needles,  f .  p.  81°. 

The  constitutional  formula  of  fluorene  is  given  on  p.  493.  It  may 
be  considered  as  formed  by  fusion  of  two  benzene  rings  and  on** 
pentaearboeyelic  ring,  with  absorption,  consequently,  of  all  but  one 
of  the  carbon  atoms  of  the  latter.  Or  it  may  be  considered  as 
diphenylene  methane,  i.  e.,  methane  in  which  2H  are  replaced  by  two 

CoH4x 
phenylene   groups,    externally   united:     I       ^CH2.      It    is,    indeed, 

closely  related  to  other  diphenylene  compounds,  in  which  the  CH2 
group  is  replaced  by  other  bivalents,  as  by  O,  S,  and  NH,  in  di- 
phenylene oxid,  sulfid  and  imid  (carbazole,  p.  538).  Other  fluorene 
derivatives  are  also  known  containing  both  diphenylene  and  diphenyl 
(p.  501)  groups,  or  two  diphenylenes,  as  diphenylene- diphenyl- 
ethylenc,  (C6H4)2C:C(C6H5)2,  and  bidiphenylene  ethane,  (C6H|)2- 
CH.CH(C6H4)2. 

Naphthalene — CioHg  —  is  obtained  commercially  from  the  fraction 


J 


CONDENSED    HYDROCARBONS 


495 


of  coal-tar  distillation  passing  betweeo  ISC^  and  300*^,  It  crystallizes 
in  shilling  plates;  f.  p.  79"^;  b.p.  218^;  volatile  at  all  temperatures, 
^ving  off  a  peculiar,  tarry  odor  (white  tar,  inoth- balls);  sparingly 
soluble  in  cold  alcohol,  readily  soluble  in  hot  akohoJ,  ether  and 
benzene.  It  is  used  in  the  arts  in  the  preparntion  of  phtbalic  acid 
and  its  derivatives,  of  the  naphthols,  etc.,  and  of  a  great  number  of 
naphthalene  dyes,  for  the  carburation  of  water-gas,  and  against 
^  moths.     Its  picric  acid  compound  fuses  at  149°. 

Naphthalene  is  undoubtedly  formed  in  the  distillation  of  coal  by 
condensation  of  lower  bydroearbous  under  the  influence  of  heat,  a 
formation  which  may  be  imitated  by  conducting  a  mixture  of  benzene 
vapor  with  acetyleue,  or  with  ethylene,  through  a  tube  heated  to 
redness.  With  ethylene,  cinnamene  (p.  442)  is  formed  as  an  inter- 
mediate product.  Naphthalene  derivatives  are  also  formed  by  con- 
densation of  several  mouobeuzenic  derivatives  with  unsaturated  lateral 
chains.     Tbns  anaphthol  is  produced  from  phenyl -isocrotouic  acid: 

.CH  —  CH  .CH  =  CH 

CflHs^  I     =CoH4<  I     +H2O;    and   naphthalene   itself   is 

HOOC.CH2  \c(OH):Ce 

formed   when    phenylbutyiene    vapcir   is    passed    over   heated    lime: 

/CH— CH 
CaH5.CH2.CH2.CH:GH2  =  C0H4  1^     +  2H2.      Oxidizing  agents 

convert  naphthalene  into  naphthoqninones  (p.  499),  and  into  benzcne- 
carboxylic  acids,  among  others  into  phtbalic  acid,  CtiH4(COOH)2* 
Sulfuric  acid  forms  with  it  sidfojiic  acids. 

Naphthalene  Homologues  ^  formed  by  substitution  of  a  Iky  Is  for 
hydrogen,  exist  in  coal-tar,  and  are  formed  by  the  action  of  alkyl 
iodids  or  bromids  upon  naphthateue  in  presence  of  Al^Clfl. 

Accnaphthene — 1,  B — (or  peri-,  p.  497)  Ethylene  naphthylcne, 

yfCHauk 

CioH«:\  I        ,  is  formed  when  «  ethyl-naphthalene  is  passed  through 

a  red-hot  tube,  and  also  exists  in  coal-tar.  By  oxidation,  nitration, 
etc.,  it  yields  a  series  of  peri -naphthalene  derivatives. 

Hydronaphthalenes  and  their  substitution  products  are  derived 
from  naphthalene  by  rupture  of  one  or  more  of  the  double  bonds, 
in  the  same  manner  as  the  hydmaromatic  compounds  are  deri%*ed 
from  benzene  (pp.  498.  486). 

Anthracene— CxiHio — is  obtained  commercially  from  the  ^*  green 
oiP'  of  coal*tar,  distilling  al>ove  270"^;  and  is  used  in  the  manufac- 
ture of  alizarin  dyes  (arttftc^ial  madder).  It  is  formed  from  benzene 
and  acetylene,  or  methylene  bromid,  in  presence  of  AlsClo.  It  crys- 
tallizes in  colorless  plates,  having  a  fine  blue  fluorescence;  f.  p.  213"^; 
b.p.  351^;  sparingly  soluble  in  benzene  and  in  carbon  bisnltid,  which 
are  its  best  solvents.  Oxidizing  agents  convert  it  into  anthraquiuone. 
Its  picric  acid  compound  forms  red  needles,  f.  p.  138"^, 


496  MANUAL    OF    CHEMISTBT 

The  constitution  of  anthracene,  given  on  p.  493,  is  proven  by 
the  formation  of  anthraquinone,  which  is  diphenylene  diketone: 
C6H4:  (CO)2:C6H4,  in  which  the  internal  bond  is  liberated. 

Phenanthrene  —  CuHio — isomeric,  with  anthracene,  aceompaDies 
that  hydrocarbon  in  coal-tar.  It  is  also  formed  by  condensation  of 
many  benzene  compounds  when  their  vapor  is  passed  through  a 
red-hot  tube.  It  crystallizes  in  colorless  plates;  f.  p.  99°;  b.  p  340*^; 
sublimes  readily  at  lower  temperatures;  soluble  in  benzene,  ether 
and  hot  alcohol,  the  solutions  having  blue  fluorescence.  Oxidizing 
agents  convert  it  into  phenanthroquinone  (p.  499).  Its  picric  acid 
compound  forms  yellow  needles,  f .  p.  144°. 

Phenanthrene  is  closely  related  to  fluorene  (p.  494) ,  and  to  diphenyl 

(p.  501) .    It  is  considered  as  diphenyl,  HC^cH.CH/C.C^^|;gg)CH, 

in  which  the  two  ortho  positions  (o)  are  united  by  the  group  — CH: 
CH — ,  while  fluorene  is  diphenyl  in  which  the  same  positions  are 
united  by  the  group  — CH — . 
CeHi  — CH 

Chrysene-I  II    —  f.  p.   250°;    b.  p.   448°  — and  Picene- 

CioHe — CH 
CioHe — CH 

I  !l^  — f.  p.  364  ;  resemble  phenanthi-ene  in  structure,  except 

CioHo — CH 

that  they  contain  one  and  two  double  naphthalene  rings  respectively 
in  place  of  benzene  nuclei.    They  exist  in  the  coal-tar  residues. 

HALOID    DERIVATIVES  — ORIENTATION. 

The  complex  character  of  the  nuclei  in  these  hydrocarbons  indi- 
cates the  possible  existence  of  a  greater  number  of  isomeres  than 
are  met  witli  iu  the  monobenzenic  series. 

With  indene  different  products  are  obtained  by  substitution  in 
the  benzene  ring  and  in  the  three  pentol  positions.  The  former  are 
designated  by  the  abbreviations  Bz,  the  latter  by  the  Greek  letters 
a,  /?,  y.     Thus  l-Bz-brom- indene: 

Br  H  COOH  H         CI 


C 

c                 c 

Ca        Ca 

^l\ 

P  ^a\                   /a%  p 

^8\   /!% 

HC2           C CH 

HC          C C          CH 

/3HC7          C          2CHj9 

1      Bz    II             II 

1            II             II           1 

1              II              1 

HC3          C            CH 

HC          C            C         CH 

/3HC6          C          3CC1/5 

V/  \y/P 

/3  V/  \     /    \<^^P 

\5/   \4^ 

c       c 

C           C            C 

Co        Co 

H          H2 

H        7H2          H 

H          H 

Bz  -Brom-indene. 

o-Pluorenic  acid. 

1.  3-DiclLlomaphtholene. 

Bi- substituted  derivatives  are  o-,  m-,  and  p-  in  the  benzene  ring, 
and  a,  /3,  y  in  the  pentol  ring.  Several  chlorindones  are  known,  up 
to  perchlorindone :    C6CU:C3Cl20. 


PHENOLS,    ALCOHOLS,    ALDEHYDES,    ETC. 


497 


There  are  three  distinct  positions  of  monosubstitution  in  the 
floorcne  nnclens;  (1)  the  four  positions  in  the  benzene  rings  nearest 
to  the  pentol  ring,  designated  as  «  ;  (2)  the  four  positions  furthest 
removed  therefrom,  designated  as  P,  and  (3)  the  single  position  in  the 
pentol  ring,  designated  as  y.    A  dibromid  and  a  tribromid  are  known. 

The  naphthalene  halids  and  other  products  of  substitntion  have 
been  better  studied.  There  are  two  positions  of  monosubstitntion, 
the  four  «  positions  nearest  to  the  fusion  of  the  two  rings,  and  the 
four  fi  positions,  furthest  removed  therefrom.  Both  «  and  ^3  ftuorids, 
ehlorids,  broniids,  and  iodids  are  kuown.  There  are  ten  possiVde  iso- 
meres  of  eaeh  bisubstituted  derivative.  These  are  distinguished  by 
using  the  numerals  attached  to  the  several  positions  as  given  above, 
or  by  the  use  of  prefixes,  as  follows  :  1,  2 -ortho,  1,  3-meta,  1,  4- 
para,  1,  5-aua,  1,  6-epi,  1,  7-kata»  1,  8-peri,  2,  3*allortho,  2, 
€-amphi,  2,  7-pros.  The  ten  possible  dichlorids  are  known.  In  all 
there  are  75  possible  naphthalene  chlorids,  of  which  26  are  known, 
and  as  many  bromids,  etc. 

In  anthracene  there  are  three  positions  of  monosubstitution :  the 
four  a  positions  nearest  to  the  uniting  groups  in  the  benzene  rings; 
the  four  jS  positions  furthest  removed  therefrom;  and  the  two  y,  or 
'''meso''  {  ^ms.),  positions  in  the  uniting  groups  (see  below).  The 
7  mono-  and  di-chlorin  and  bromin  compounds  are  formed  in 
preference. 


H 


/IHC7 


8\/m 
C 


CH3 
C     Y 


H 


8.\/l\ 

C       2CH  /9 


C  C       3CH  /J 

a  C  C       7     C  a 

H  CH3       H 

i.  (or  y)  Dlm«thjrl  Anthracene. 


H    H  H     H 

/  \  /  \ 

HC  C— C  CH 

C— C  C— C 

Htt    \  /Ha 

c=c 

H^    /3C00H 


In  phenanthrene  there  are  five  positions  of  monosubstitution  : 
one  in  eaeh  of  the  o-,  01-,  m-,  nn-,  p-,  and  pi-  positions  of  the 
diphenyl  (p.  501),  the  two  remaining  ni- positions  of  the  dipheny], 
designated  as  «,  and  the  two  positions  in  the  connecting  group, 
-C:C-,  designated  as  fi.  Chlorids  are  known  as  high  as  the  octo- 
chlorid,  and  bromids  as  high  as  the  heptabromid. 


PHENOLS,    ALCOHOLS,    ALDEHYDES,    KETONES,    QUINONES, 
CARBOXYLIC   ACIDS. 

The  phenols,  particularly  those  of  naphthalene,  the  oxynaph- 
thalenes,  or  naphthols,  are  the  most  important  of  those  compounds. 
The  naphthols  exist  in  coal-tar,  and  are  also  manufactured  sjTitheti- 


498 


MANUAL    OF    CHEMI8TBS 


cally  by  the  methods  iadicated  below.  They  readily  form  ethers,  and 
with  ammonia  they  produce  the  corresponding^  eaphthylamins.  Both 
naphtbols  are  nsed  medicinally  as  antiseptics, 

a-Naphthol  --  CitiH:.  ( OH )^  —  is  obtuined  by  heating  phenyl- 
isocrotonit;  acid  (p.  495);  also  by  boiling  an  aqueous  solution  of 
diazonaphthalcne  nitrate  with  nitrous  acid,  or  by  fusing  a -naphtha- 
lene-sulfonic  acid  with  KHO. 

It  crystallizes  in  colorless  prisms;  f,  p.  95*^  (203*^  F.);  b,  p.  280^ 
(536°  F.);  nearly  insoluble  in  water,  soluble  in  alcohol  and  in  ether; 
is  easily  volatile,  and  has  the  odor  of  phenoL  It  gives  a  transient 
violet  color  with  Fe^jCle  and  a  hypochlorite.  With  nitrous  acid  it 
forms  2,  1  and  4,  1  nitroso-naphthols*  Potassium  chlorate  and  hy- 
drochloric acid  oxidize  it  to  diehloro- naphthoquinone.  Nascent 
hydrogen  (sodium  and  alcohol)  reduce  it  to  ar-tetrahydronaphthol 
(below).     Its  acetate  fuses  at  46°  (114.8°  Fj. 

/5-Naphthol^ — CioH7(OH}^ — is  prepared  industriall}^  by  fusion  of 
sodium  ^-naphthalene -sulfonates  with  NaHO,  for  use  in  the  manu- 
facture of  a  number  of  dyes,  among  which  are  Cannpobello  yellow 
and  the  tropeolins.  It  crystallizes  in  colorless,  silk^t^  plates,  which 
turn  dark  in  daylight;  has  a  faint  phenol- like  odor,  and  a  sharp^ 
burning  taste  ;  f.  p.  123°  (253.4°  F.);  b.  p.  286°  (514.8° PJ;  spar- 
ingly soluble  in  water,  readily  soluble  in  alcohol  and  in  ether.  It 
gives  a  greenish  color  with  Fe2Clfi.     Its  acetate  fuses  at  70°  (158°  F,). 

Substituted  Naphtbols. — Both  naphthoic  form  a  great  number  of 
derivatives  by  suljstituHon  of  other  groups  for  hydrogen  atoms. 
Many  of  these  are  important  dyes.  Thus  Martius  yellovir  is  the  Na 
salt  of  2,  4'dinitro-a- naphthoic  a  poisonous  pigment  sometimes  used 
to  color  butter  and  cninfeetionery.  Naphthol  yellow  is  the  dipotas* 
sium  salt  of  dinitro-i-naphthol-S- sulfonic  acid.  The  naphthols  com- 
bine  easily  with  the  diaxo-  and  azoM*ompounds  {p.  481)  to  form  a 
number  of  azo-naphthol  derivatives,  several  of  which  are  important 
dyes,  as  the  naphthol  oranges  and  Bicberich  scarlet.  A  great  va- 
riety of  naphthol-sulfonic  acids  have  also  been  prepared  for  use  in 
the  color  industry,  m  in  the  preparation  of  the  various  ponceau  and 
Bordeaux  dyes.  These  sulfonic  acids,  being  basic  by  their  OH 
group  and  acid  by  the  HSOs  gi'onp,  form  lactone-like  compounds 
(p.  368},  whifih  are  called  sultones. 

Tetrahydro naphthols  are  formed  by  the  introduction  of  four  H 
atoms  into  one  of  the  benzene  rings,  by  the  aetion  of  nascent  hydro- 
gen upon  the  naphthols*  If  the  hydrogenation  occur  in  the  ring 
containing  the  OH,  one  product  is  obtained,  designated  by  the  pi*efix 
ac-,  whereas  if  it  occur  in  the  other  ring  a  different  substance  is  pro- 
duced»  designated  by  the  prefix  ar-* 

Anthraphenols.  —  Three  monopheuols,   Ci4H9(OH),  are  known: 


■ 


PHENOLS,    ALCOHOLS,    ALDEHYDES,    ETC. 


499 


I 
I 


A  aod  i9  anthrols,  which  behave  like  pheuols  and  iiapIiHiols;  and  itis- 
(or  y)  oxyanthracene,  or  anthranol  (p,  497),  which  is  readily  oxi- 
dized to  anthraquiBone  (below).  Two  Bz-dioxyanthraccneSt  OH.- 
CeHa:  (CH)2:C6H3.0H,  called  chrysazol  and  rufol,  are  also  known. 
Alcohols  of  this  series  are  known;  some  primary;  as  the 
Naphthyl  Alcohols ---CioHt.CHoOH— which  are  formed  by  th6 
action  of  nitrons  acid  upon  the  corresponding  arains  (p.  286).  The 
a  alcohol  fuses  at  50°;  the  P  boils  at  80"", 

C  H 

Fluorcne  Alcohol— I '   *)5CH.0H— f.  p.  153^  is  formed  by  re- 

doction  of  flnorene  ketone  (below). 

Naphthyl  Aldehydes — C10H7.CHO — arc  obtained  by  oxidation  of 
the  alcohols.     Tlie  ^  aldehyde  boils  at  2D1'';  the  1^  fuses  at  59''. 

The  ketones  are  either  ring  ketones,  such  as  those  of  iodene  and 
flaoreQe^  or  the  CO  group  is  in  a  lateral  chain,  as  in  the  naphthalene 
ketonea. 

T^-Indone — CcHi:  Wq/CH — is  known  in  its  CI  and  Br  derivatives; 
also  a  and  P  hydrindooes.  C0H4 :  <(co ')>CH2  and  CfiH,:<(eH!/CO. 

Fluorcne  Ketone  —  Diphenylenc  Ketone — I      yCO---f.  p.  84  , 

is  formed  by  oxidation  of  fluorene  with  chrdmie  acid  mixture,  and 

C0H4.COOH 
ako  from  diphenic  acid,  I 

Naphthyl-methyl  Ketone~('i(iHT.CO.CH:r— is  formed  by  the  ac- 
tion of  acetyl  chlorid  upon  naphthalene  in  pwsenee  of  AI2CI0. 

Both  aldehydes  and  ketottes  for^  oxims  and^  hydrazones  (pp.  409* 
485). 

Quinones.  —  Naphthalene,  anthracene  and  phenanthrene  readily 
yield  quinones  (p,  451),  some  of  which  are  technicaUy  prepared  by 
oxidizing  the  hydrocarbons  in  acetic  acid  solution  by  chromic  acid; 
or  from  the  dioxy-  or  diamido-componnds. 

Naphthoquinones* — ^Oxidationof  naphthalene  produces  a  naphtho- 
quinone, CinHo:02.,.4i,  which  crystallizes  in  yellow  needles,  fusible  at 
125*^.  The*i-^  qnioone,  CinHn;02<f,»>,  is  formed  by  oxidation  of  fi 
amido-^i-naphthol,  and  crj^stalHzes  in  red  needles,  fusible  at  115*^. 
Both  tiapbthoquinones  form  oxiras  and  hydrazones,  some  of  which 
are  used  in  the  color  industry.  / 

Anthraquinonc  — Diphenylene  Diketone — C0H4:  (CO)2:CflH4—  is 
commercially  manufactured  by  oxidation  of  anthracene.  It  foiTus 
yellow  needles;  f.  p.  285°;  b,  p,  382^.  It  forms  an  oxim  with  hydrox- 
rlamin,  and  sulfonic  acids  with  U2SO1,  as  well  as  chlorin,  bromia 
and  oxy-  derivatives. 


500 


MANTJAL    OF    CHEMISTEY 


Alizarin — 1,  3*Dioxyanthraqutnone — C6H4:  (CO)2:C8H2i  (OH) 2^ 

is  prepared  industrially  by  the  action  of  fused  NaHO  opoa  anthra* 
quinoue-moQosulfonic  acid,  and  is  also  formed  by  fusion  of  several 
other  anthraquiuone  derivatives  with  caustic  alkalies.  It  is  the  color* 
ing  principle  of  madder  (Rubta  Unetoria),  aod  the  artificial  product 
has  now  completely  displaced  madder  in  dyeing- 

Purpurin— 1, 2, 4'Trtoxyanthraquinone— CgH4:  (CO)2:CflH:(OH)3 
—  is  another  constituent  of  madder,  also  obtained  artificially  by  oxi- 
dation of  alizarin,  or  from  tribronio*anthraq|Mone. 

Both  alizarin  and  purpurin  form  nitroxVaiU  amido-  substitution 
products  which  are  also  used  as  dyes;  alizar?|Jorange,  blue  and  brown. 

Several  oxyniethylanthraquinones  are 
tive    drugs.     Chrysophanic,  or  rhcic  ac^ 
rhubarb,  cascara,  goa- powder,  is  dioxyr 
(C0)2  :  CeH,CH3  I  {0H)2.       Reducing 
chyrsarobin,    CaoHaeOTi?),    which    also\ 
finally  into  methylanthraquinone,     Emoi 
frtifif/ttla    and    in    rhubarb,    is    trioxymc 
(CO')2:C6.CTI:i;(OTl);, 

Carboxylic  Acids.'^xV  great  varie^ 


fcive  principles  of  purga- 
which  exists  in  senna, 
fhylanthraquinone.  CsHi; 
kits  convert  it,  first  into 
Jcists  in  goa- powder,  aud 
which  exist  in  Rhamnns 
ianthraquinone,    C^H*:  - 


indene,  hydriodeue| 
tut  ion  of  COO  a 
Naphthalene 
coon  — are    form^ 
fuses  at  160'';   the^ 
acids.     They  forn 
amido-,  etc,  amoc 
OtLt^OOH,  which^ 
The  rfbphthakne\ 
(p.  49^,   the 
dicaU>ox^ic  EC  4 
(CI 


orene, 
ps  ft>r 
car 
by   h 
at  182 
great  v 
hich  are 
lily  deccH 
and 
known    bell 
rnied  by  tlie 


if  lidds  are  derivable  from 
d  phenauthrene  by  suhsti- 


hthoic  Acids — CioH:- 

fh^    uitrils.     The   «  aeiA 

lolognes  are  naphthyl-fatty 

ihstitntiou  products,  uiUv-  , 

oNcarboxylic  acids,  Ciofl(-  - 

water  and  laelones  (p.  368  )  , 

xylic  acids  are  very  niniieroti> 

hthalic,  or   1,  8-naphthalcn« 

tion  of  acenaphthene,  OiuHe  =  * 


acids, 
CmHT.SOs 
the  latter  prl 
are  converted 


Ifonlc   Acids,   corresponding  to  the  carbW^**' 

nowli.   The  a-  and  /?- naphthalene  monosulfonic  a<'id^' 

ed  by  the  action  of  sulfuric  acid  on  naphtbaleu^* 

^  ig  when  the  action  occurs  at  160"^.    These aci<i^ 

toehlurids:  CiuHtSOsCI,  by  PCU. 

NITROGEN   DERIVATIVES. 


NaphthaleneT'^anthracene,  and  phenanthrene  form  a  number  rf 
nitro,  amido,  azo,  and  hydrazin  derivatives,  of  which  only  a  tew  ot 
the  naphthalic  compounds  require  brief  mention. 

Naphthylamins— Aniidonaphthalenes— CioHt.NHa.    Both  a  aud  ? 


DIPHENYL    AND    ITS    DERIVATIVES 


601 


^mponnds  are  foriutHl  by  rt'diietion  of  tlit*  f'orres ponding  nitro- 
' naphthalenes,  Cn)ll7.N02;  or  by  the  action  of  ammonia  npon  the 
naphthois  in  presence  of  zineehlorid:  CioH7.0H+NH3=CimH7.NH2+ 
H2O,  the  latter  a  method  of  forraatiou  which  is  not  realized  with  the 
amidobenzenes  (p.  473),  The  o,  amin  cryBtallizes  in  flat  needles; 
f.  p.  50°  (122''  P.) ;  b.  p.  300''  (572''  PJ;  insoluble  in  water,  soluble 
in  alcohol  and  ether j  becomes  red  on  exposure  to  air;  has  a  per* 
fiisteut  and  disagreeable  odor.     On  moderate  oxidation  it  forms  a 

blue  compoundi  oxynaphthylamin,  CioHaCqu^;  on  more  complete  oxi- 
dation <^  naphthoquinone.  The  ^  amin  crystallizes  in  plates;  f .  p.  112*^ 
t  (233.6''  FJ ;  b.  p.  294''  (561.2"  F.) ;  dissolves  in  hot  water,  forming 
a  blue -fluorescent  solution.  On  oxidation  it  forms  phthalic  acid. 
Tctrahydro  /^-naphthylamiti,  CioHn.NHs,  is  a  very  active  mydriatic. 

Several    naphthylamin- sulfonic   acids   are    manufactured    in    the 
color  industry,  as  well  as  diazo-  and  azonaphthalene  compounds. 


I 


D.     DIPHENYL  AND   ITS    DERIVATIVES. 

Diphenyl»  CflHs.CflHs*  is  the  type  of  the  hydrocarbons,  known  as 
phenylbcnzenes,  formed  by  the  snbstitntion  of  phenyl,  tejluyL  benzyl, 
PtL\,  for  atoms  of  hydrogen  in  benzene  (see  formula  of  p'>-diamido- 
diphenyl,  p.  439).  Thus  we  have,  besides  diphcnyl,  toluyl-benzene^ 
<AtU.C6H4.CH3,  diphcnyl-bcnzenc,  CnH^:  (C6H5)2,  and  triphenyl- 
henzcne,  C«H;«  :  (CeH5)3»  These  hydrocarbons  are  the  parent  sub- 
stances of  a  great  number  of  substitution  pi-odncts-  The  monosub- 
stitnted  conipoonds  are  o*,  m-,  or  p-,  with  reference  to  the  point  of 
^^uon  of  the  benzene  rings.  In  the  hi-  and  polysubstituted  deriva* 
*^»ves  the  substituents  may  be  introduced  into  the  same  or  into  differ- 
^^l  rings.  Bi- substitution  of  bivalent  groups  for  H2  in  the  0-02- 
^*^itions  produces  compounds  belonging  to  other  series  of  our 
'^'ossification.  Thus  flnoreue  and  phenaothrene  (p,  493)  are  deriva- 
^^^frora  diphenyl  by  substitution  of -C'H 2-  and  of  -CH.CH^  respect- 
^^^Ij' in  the  0*02-  positions.  Diphenylene  oxid  and  aulfld  and  ear- 
**«^zole(p.  538)  are  similarly  derivable  from  diphenyl  by  substitution 
^t  0,  s,  and  NH. 

Diphcnyl^Phcnyibenzene — CftH5.C«H,^ — exists  in  small  quantity 
*^  gas -tar.  It  is  formed  by  the  action  of  sodium  upon  monobromo- 
Wene:  2CaHfiBr+Na2=CtiH&.CoH5+2NaBr;  or  by  passing  benzene 
^apor  through  a  red-hot  tube;  or  by  the  interaction  of  diazoben- 
*ene  chlorid  and  benzene  in  presence  of  aluminium  chlorid:  CGHji.- 
NrXCl+  CeH<j=CflH5.CGH&+  HCI+N3.     It  crystallizes  in  large  plates; 


tp,  70^  (158''F.};  b,  p.  254' 
mid  and   in   amylic  alcohol. 


(489.2"*  FJ;  soluble  in  glacial  acetic 
Nascent   hydrogen   converts    it   into 


502 


MANUAL    OF    CHEMISTRY 


tetrahydro'diphenyl,  C12H14.     With  methylene  eWorld,  in  presence  of 

AisClfi  it  forms  fluoretie:  lVH5.C«H5+CH2Cb=Ceij7cH^6H4+2HCU 
Difluor-diphenyl,  C6ll4F.CftH4F,  is  a  white,  crystalline  powder^  used 
as  an  antispasmodic  under  the  name  antitussin. 

Amido-diphenyls,  toluyls,  etc.,  can  be  obtained  by  reduction  of 
the  corresponding  nitro-corapounds*  One  of  these,  benzidin,  or 
p^'diamido-diphenyl  (formula  p.  439),  is  a  product  of  technical  ini* 
portance,  which  is,  however,  manufactured  by  reduction  of  azoben* 
zene  in  acid  solution.  Azobenzene,  CflHg.N:N.CcHr,,  first  forms  hy- 
drazobenzene,  CflHs.NH.NH.C^jHs  (p.  483)\  which  by  further  hydro- 
geuation  and  transposition,  yields  henzidin,  NH2u].C6H4/C6H4.NHi. . 
Benzidin  serves  for  tlie  inanufaetnre  of  a  niiniber  of  azo  dyes,  which 
are  sulfonic  or  carboxylic  acids,  or  their  salts.  Among  these  benzi- 
din dyes  are  Con^o* yellow  and  Con^o-red. 

Oxydiphenyls  are  the  phenols  of  these  hydrocarbons,  and  are 
formed  by  fusing  the  benzenic  phenols  with  KHO.  The  hexaoxv- 
diphenyl  derived  from  pyrogallol  {p.  450)  yiekis  a  quinone  (p.  451) 
whose  methylic  ester  is  ccerulignone,  O^iCjaHflCOCHa)**  the  amido 
derivatives  of  which  form  a  number  of  blue,  violet  and  black  dyes. 


3 


E.     DIPHENYL- PARAFFINS,    DIPHENYL-OLEFINS. 
DIPHENYL-ACETYLENES. 

The  hydrocarbons  of  this  series  may  be  considered  as  deriv 
from  the  aliphatic  hydrocarbons  by  substittition  of  two  (or  more 
phenyl  groups  for  hydrogen  ; 

CoHs^CHa— Phenyl -m©tliiiiie=Tolu©iie=^Methyl-beii««ne  (p.  441). 

CflHs.CHs.CftHs— Dipheoyl  ^niethane^==  Benzyl -benzene  {formuls  p.  439). 
(CpjH5)2'CH.C,»Hs—Tripb6nyl -methane. 
(C«H5)2 : 81  :(C»Hs)3—TBtra phenyl -flilieon  (C  eompoiind  nnknown). 

CeUs.CHi.CHj^CflHfl— Sym.  Diphenyl -ethane=Dibeczyl. 
(C*Hs)a:CH.CH3— Unaym.  Diphenyl-ethane. 

CeHa.CHiCH.CuHs— Syra.  DiphenyUethyl©ne=8tilb©ne. 

CttHft.C^C.CtHs— Dipheny!-acetylene=ToJane. 

Diphenyl  -  methane — Benzyl -ben  zene — is  produced  by  the  actloc:' 
of  benzyl  chlorid  upon  benzene  in  presence  of  aluminium  chlorid: 
CflH5.CH2.Cl+CeHfl=CflH5.CH2.C6H5+HCl.    It  is  a  crystalline  soli<l; 
f.  p,  27'*  {80.6°  F.);  b.  p,  262''  (503. 6"^  F J ;  soluble  in  alcohol,  ether, 
and  chloroform;  has  an  odor  resembling  that  of  the  orange. 

Triphenyl-mcthane^"is  formed  by  the  action  of  chloroform  upon 
benzene  in  presence  of  aluminium  chlorid:  3C*6H(j+CHCl3=(C6n5)!: 
€H.CeHa+3HCl.     It  is  a  crystalline  solid;  f .  p,  92*"  (197.6''  F.) ;  b.  p 


PHENOLS,  ALCOHOLS,  KETONES,  ETC. 


503 


360  (680  F.);  soluble  iii  ether  ijtitl  in  ijililm-ofurui.  It  is  converted 
into  a  trinitro*denvative  by  fuming  HNO:r;  and  this,  in  turn,  is  con- 
verted by  nascent  H  into  leuco-pararosanilin,  CH.(C«H4.NH2)3* 

Stilbene— Toluylene— Sym.  Diphenylethyleoe  —  is  formed  by 
distillation  of  benzyl  snlM-  by  reduction  of  benzoic  aldehyde;  or  by 
distillation  of  the  phenylic  esters  of  fumaric  (p.  430)  or  cinnatnio 
(p.  457)  aeids«  It  forms  large,  glistening  prisnis  or  plates;  f.  p. 
124°  (255.2*"  P.)  ;  b.  p.  306''  (582.8"^  F.}.  It  forms  a  number  of 
haloid  and  other  derivatives. 

Tolanc — Diphcnyl- acetylene — ^is  formed  by  the  action  of  KHO 
npon  stilbene  bromid.     It  is  a  crystalline  solidj  f.  p,  60"^  {140"^  F;), 

Diphenyl-diacctyleoe  —  CdHs.C^C.C^CCoHs  —  is  formed  by 
moderate  oxidation  of  copper  phenyl- ace tylid,  CflHr,.C=C.Cu.C^O,- 
CttHs,  as  a  crystalline  solid;  f.  p.  88°  (190.4''  Fj.  Its  o,  02-dinitro- 
derivative  is  converted  into  indigo -blue  (p.  542)  by  reduction. 


PHENOLS.   ALCOHOLS.    KETONES,    AND    CARBOXYLIC    DERIVATrVES. 

Phenolic  derivatives  of  these  hydrocarbons  are  known,  which 
contain  hydroxyls  in  one  or  more  of  the  phenyl  groups. 

Diphenyl  Carbinol— Benzhydrol— CeH^.CHOHX'eHs— is  the  sira* 
plest  alcohol  of  this  series.  It  is  formed  in  colorless  crystals;  f.  p. 
6S^\  b.  p.  298^;  by  reduction  of  benzophenone  with  sodium  amal- 
gam. CftH5.CO.CeH5  +  H2  =  CeH&.CHOH.CeHs.  Its  tctramcthyl- 
dianiido-  derivative,   CHOH<^^^j^^^^Jqjj'^j^,  forms  colorless  crystals, 

^hich  dissolve  in  acetic  acid  with  an  intense  blue  color.  It  is 
formed  by  the  action  of  lead  peroxid  and  acetic  acid  upon  tetra- 
methyl- diamido-diphenyl  methane,  which  is  produced  by  heating 
dimethyl  aoilin  with  formaldehyde  and  a  little  sulfuric  acid  :   2C6H5.- 

N(CH3)2+H.CHO==CH2    e;S;:NlcS  These    reactions  are 

used  as  a  test  for  formaldehyde. 

Triphenyl  Carbinol,  (CftHR)aC.OH,  and  diphenyl-m-toluyl  car- 
binol,  (CoH5)-:C(OH),CaHi.CH3.3>,  are  alcohols,  whose  trianiido- 
derivatives  are  pararosanilin  and  rosanilin.  They  are  formed  by 
oxidation  of  the  hydrocarbons.  They  form  nitro*  and  auiido- deriva- 
tives of  technical  importance. 

The  benzophenones,  the  ketones  of  this  series »  correspond  to  the 
phenones  (p.  455) »  from  which  they  differ  in  containing  two  phenyls 
in  place  of  one;  and  they  bear  the  same  relation  to  the  benzoic  acids 
that  the  acetones  (p.  307)  do  to  the  fatty  acids.  They  are  produced 
by  oxidation  of  the  hydrocarbons  ;  by  the  action  of  P2O5  upon  a 
mixture  Of  a  benzene  hydrocarbon  and  a  benzoic  acid;    or   by  the 


MANUAL    OF    CHEMISTRY 


actioo  of  phosgene  or  of  an  acidyl  cblorid  upon  benzene  in  presence 
of  aliimioiurn  i4ilori<!. 

Benzophcnone  —  Diphenyl-kctone— CeHsX'O.CflHs — forms  large 
rhombie  prisms?  f.  p.  48°  (118.4°  P.);  b.  p.  305°(581°  FJ;  soluble 
in  alcohol  and  ether.  Sodinra  amalgam  reduces  it  to  benzhydrol, 
or  diphenyl  carbinol,  (CoH5)2:CH.OH.  Benzopbenone  is  the  parent 
sabstanee  of  a  great  number  of  substitution  products,  some  of  which 
are  used  in  the  color  industry. 

Benzoin — CoH5.CH(OH).CO.CflH5 — which  exists  in  crude  oil  of 
bitter  almonds,  is  a  keto- alcohol  corresponding  to  hydrobenzoin,  or 
toluylene  glycol,  CoH&.CH{OH).CH(OH).CsH:.,  which  is  formed  by 
the  action  of  nascent  H  upon  benzoic  aldehyde  (p.  453). 

Benzil — Dibenzoyl — C^Hs/CO.CO.CoHa — is  a  dike  tone,  obtained 
by  the  action  of  moist  silver  oxid  upon  stilbene  bromid, 

Carboxylic  acids  derived  from  the  diphenyl- methanes,  such  as 
benzoyl-benzoic  acids,  CfiHf,.CO.C6H4.COOH,  and  acids  derived  from 
stilbene  and  from  diphenyl -diacetylene  ai-e  known.  But  few  of  the 
carboxylic  acids  derivable  from  triphenylmethanes  are  known,  owing 
to  their  tendency  to  lose  water  and  form  lactones.  Among  these 
lactones  are  the  phthalems  and  numerous  other  dyes,  such  as  rosolic 
acid  and  the  aurines. 

The  phthaiids  of  this  class  may  be  considered  as  derived  from 

phthalid  (p.  462) ^  CeiIl4\cH2ra)/^'  which  is  the  lactone  of  o-oxyme- 
thylbenzoic  acid,  CaH4<^(^u^qh^^^  ,  by  substitution  of  phenyl  for  hydro- 
gen in  the  CH2  group.  Thus  diphenyl  phthalid,  obtained  by  oxidation 
of  triphenyl  methane  o -carboxylic  acid,  C6H4ycH(C#H8)s(,}'  ^*^  ^^^ 
constitution!  C6H4\^''Ji-^0        .    The  phthalems  have  been  eonsid- 

C(3l  =  {CdHr)2 

ered  as  oxyphenyl  ketonic  derivatives  of  phthalic  acid,  as  indicated 
on  p.  451,  or  as  lactones  derivable  from  phthalid  by  substitution  of 

oxyphenyl  groups.     Thus  phenol  phthaleTn,  CfiH4\    J^O 


C,.,  =  (C»H4.0H)j. 


NITROGEN -CONTAINING   DERIVATIVES. 


Among  the  great  number  of  nitro-  and  amide -derivatives  of  theee 
hydrocarbons  the  most  important  are  the  araido- derivatives  of  tri- 
phenyl-carbinol  (p.  503).  From  those  in  which  two  or  three  of  the 
araido  groups  occupy  the  para  positions  with  regard  to  the  C(OH} 
group,  or  from  their  alkyl  derivatives,  a  number  of  important  dyes, 
red,  green,  violet,  blue,  and  brown,  are  manufactured. 

p-Am ido-tripheny Imethane —  ( CeHs) 2 :  CH . Ceiii. NHsu) — is  formed 


NITROGEN -CONTAINING    DERIVATIVES 


50^ 


})j  the  action  of  beiizhrtlro!  upon  anilin  elilorid  in  presence  of 
zine  cblorid.  The  corresponding  earbinol  forms  salts  which  have  no 
coloring  power, 

pi-Diamido-triphenylnnethane — C6H5.CH:  (CoH4.NH2(4j2 — is  pro- 
duced by  the  interaction  of  anilin  chlorid  and  benzoic  aldehyde  in 
presence  of  zinc  chlorid,  and  by  other  methods.  The  base  is  a  yellow > 
imperfectly  crystalline  solid,  insoluble  in  water,  soluble  in  alcohol  and 
in  benzene;  which  forms  bine  salts.  The  con-espouding  carbiool, 
CeHft.C(OH):  (C6H4.NH2r4j)2  forms  a  chlorid  which  is  a  reddish-violet 
dye. 

p2-Tetramethyl  -  diamido  -  triphenylmethane  —  CeHs-CH :  [CoHi.- 
N(CU3)2(4>]2 — is  manufactured  by  the  action  of  sulfuric  or  hydro- 
chloric acid  upon  benzoic  aldehyde  and  dimethyl- anilin.  It  and  its 
earbinol  are  almost  colorless  bases,  which  form  salts  which  are 
brilliant  green  dyes,  leucomalachite  green  and  malachite  green»  or 
bitter  almond-oil  green. 

Triamido-triphenyl  methanes  and  their  alkyl  derivatives  (see 
below)  are  known  as  leucanilins  (Xeuic(k= white)  from  the  fact  that, 
while  some  of  their  derivatives  are  brilliantly  colored,  they  are  color- 
less, or  nearly  so.  By  oxidation  they  yield  carbinols,  formed  by  the 
Bubstitutiou  of  OH  for  H  in  the  connecting  group  CH,  known  as 
rosanilins,  which  are  powerful  triacid  bases,  whose  salts  are  the  dyes 
referred  to.  The  most  important  industrially  are  those  having  at 
least  two  amido- groups  in  para  positions.  Their  constitution  is 
indicated  by  the  following -formulae  : 


— NHj         HjN- 


0 


NHa 


-NH2 


(o-LeiiPanllinK 


I— Trlwoldo-triphtnyl  metbAne 


fisN 


NHi 


'-0 


I 
NH2 

PfTrlAmJlcla-trlphi^oLyl  meth&zif 


-KH'i 


NHs 

pj'TiiAmido-dlplietifl-tii'tolttyl  melhuie 
(L«acanilln). 


or^  by  a  diflferent  form  of  expression  for  the  corresponding  carbin- 
ols;   the  rosanilins: 


506  MANUAL    OF    CHEMISTRY 

/  CeHi .  NH2(4)  /CflH*  .NH2(4) 

HO.C-CflH4.NH2(4)  HO  C— C6H4.NH2(4) 

\C8H4  .NHac)  \C»H4  .NH2C3) 

/C»H4  .NH2(4)  /C»H4  .NH2(4) 

HO.C— C«H4  .NH2(4)  HO.C— C»H4  .NH2(4) 

\C5H4.NHa(4)  \CeH3.CH3(3).NH,u) 

Of  these  the  ps-triphenyl,  and  the  pa-diphenyl-m-toluyl  earbin- 
ols  and  their  methyl,  ethyl,  benzyl,  and  phenyl  derivatives  are  ex- 
tensively used  in  the  color  industry.  Fuchsine,  anilin  red,  or 
magenta  consists  chiefly  of  the  acetate  or  hydrochlorid  of  pa-tri- 
amido-diphenyl-m-tolnyl  carbinol,  or  rosanilin.  It  is  manufactured 
by  oxidation  of  "anilin  oil"  (p.  474),  which  is  a  mixture  of  anilin, 
and  o-  and  p-toluidin,  by  heating  with  a  mixture  of  nitro-benzene, 
hydrochloric  acid,  and  iron  filings.  Formerly  arsenic  acid  was  used 
as  an  oxidant,  when  the  fuchsin  was  obtained  as  a  poisonous  arsenite. 
Puchsin  forms  green  crystals,  having  a  metallic  luster,  soluble  in 
water  and  in  alcohol,  to  which  it  communicates  a  bright-red  color. 
This  color  is  discharged  by  sulfurous  acid,  and  regenerated  by  alde- 
hydes, and  such  a  decolorized  magenta  solution  is  used  as  a  reagent 
for  the  detection  of  aldehydes  (Schiff's  reagent). 

By  the  action  of  methyl  iodid  upon  fuchsin  a  number  of  methyl- 
ated derivatives  are  obtained,  which  are  violet  dyes,  such  as  crystal 
violet,  Hofmann's  violet,  dahlia,  etc.  By  further  methylation  of 
the  violets,  green  dyes  are  formed,  as  the  iodin  greens,  and  aldehyde 
green.  By  substitution  of  phenyl  in  place  of  methyl,  a  number  of 
blue  dyes,  as  Lyons  blue,  soluble  blue  and  alkali  blue  are  ob- 
tained. Pyoktanin -blue,  dahlia,  is  penta-  and  hexa-methyl  para- 
rosanilin  hydrochlorid,  produced  from  dimethyl  anilin.  It  is  a  violet 
powder,  soluble  in  water  and  very  diffusible,  non -poisonous  and 
used  internally  as  an  antiseptic.  Pyoktanin-yellow,  used  medici- 
nally for  the  same  purposes  as  the  bine,  is  the  hydrochlorid  of  imido- 

tetramethyl-diaraido-diphenyl  methane,  HX:C(^^;;n*;^:|cH')!-  '^ri- 
phenyl  -  pararosanilin,  HO.C  i  ( C6H4.NH.C6H5  )3,  is  the  base  of  a 
number  of  blue  dyes,  among  which  is  methyl  -  blue,  the  sodium  salt 
of  its  trisulfonic  acid,  which  has  been  used  locally  in  diphtheria. 
It  is  poisonous,  and  has  caused  death  by  its  administration  m  mis- 
take for  methylene -blue  (p.  'ylO) , 


HETEROCYCLIC    COMPOUNDS 


507 


HETEROCYCLIC    COMPOUNDS. 


These  compounds  differ  from  the  earbocyclic  in  that  they  contain 
elements  other  than  carbon  as  constituents  of  the  nuclei.  They 
form  series  parallel  to  the  earbocyclic,  from  which,  indeed,  they  may 
be  considered  as  being  derived  by  substitution  in  the  rings.  Thus 
thiophene  corresponds  to  pentole,  pyridin  to  benzene,  and  quiuolin 
to  naphthalene: 


HC- 


-CH 


HC  CH 

\    / 

C 

H2 
Pentole. 


HC- 

II 
HC 


-CH 

II 
CH 


\    / 
S 

Thiophene. 


H 
C 

/  % 
HC  CH 

II  I 

HC  CH 

\   ^ 

C 

H 

Benzene. 

H 
C 

/    \ 
HC  CH 

II  I 

HC  CH 

N 

Pyridin. 


II 
C 
/'    \     / 
HC  C 


CH 


HC  C  CH 

\    /    \    ^ 
C  C 

H  H 

Naphthalene. 

H  H 

C  C 

-/    \    /    \ 
HC  C  CH 

I  II  I 

HC  C  CH 

%    /    \    ^ 
C  N 

H 
Qoinolin. 


The  elements  which  can  be  thus  introduced  into  a  cyclic  nucleus 
are  few  ;  oxygen,  sulfur,  selenium,  phosphorus  and  nitrogen  being 
the  only  ones  now  known  to  enter  into  such  formation,  and  of  these 
the  nitrogen -containing  compounds  are  far  the  most  numerous  and 
the  most  important.  The  facility  with  which  the  N  atom  takes  the 
place  of  the  methine  group, —  CH  =,  in  the  benzene  ring  is  to  be 
anticipated  from  their  equivalence.  Pyridin  also  resembles  benzene 
in  its  general  characters,  and,  on  the  other  hand,  the  five  membered 
compounds,  furfurane,  thiophene  and  pyrrole,  have  general  charac- 
ters similar  to  those  of  benzene,  from  which  they  may  be  considered 
as  being  derived  by  substitution  of  the  bivalents  O,  S,  and  NH  for 
one  of  the  three  acetylenes, —  CH:CH — ,  of  benzene.  The  number 
of  hetero- atoms  which  may  be  contained  in  the  nucleus  is  not 
limited  to  one,  and  five  and  six  membered  rings  containing  as  many 
as  four  nitrogen  atoms,  the  tetrazoles  and  tetrazins,  are  known. 

A  classification  of  the  heterocyclic  compounds  requires  many 
subdivisions,  because  of  the  great  number  and  variety  of  these  sub- 
stances, due  to  the  presence  of  one  or  more  atoms  of  one  or  more 


SOS 


MAXtJAL    OP    CHEMISTRY 


of  the  elements  above  mentioned,  in  three,  four,  five  or  six  mem- 
bered  rings,  contained  in  mono-,  di-,  ti*i-,  or  tetra- nucleate  aiole- 
cales,  in  which,  also»  differences  in  the  ring-valeuce  are  caused  by- 
differences  in  internal  linkage*  A  broad  classification  may,  however, 
be  here  followed »  somewhat  similar  to  that  for  the  aromatic  sub- 
stances (p.  439). 

A.  Mono -nucleate  compounds:  containing  a  single  nucleus.    These 
may  be  subdivided  into:  (a)  Substances  eontaiaing  three *membered 

rings;    such    as    ethylene   oxid,    _  L/0*  suldd, 
l>NH. 


HiC 


/^ 


H;.C 


>. 


and    imid, 


(b)  Four -mem  bered 
H2C-O  HaC— O 

I     I      ,  thetin,      1 
H2C — CH3  I12C' 


compound?,    such    as    trimethylene 

I  ,  and  trimethvleue  imid,      1     I     . 
S  H:C— NH 

HC=CH 


oxid, 


\r 


Ic)  Pive-membered  substances,  such  as  furfurane,      I  ^O.thi- 


>NH. 


HC=^CHv  HC=CHv 

opheoe,     I         yS,  and  pyrrole,      I         yl 

HC-CH=CH 
(d)  Six-membered  compounds,  such  as  pyridin,     Ih  I    ,  pi- 

HC" — CH^N 
HjC-CHa— CHs  N=N-CH 

peridin,      I  I      ,  and  sym.  tetrazin,      I  II    . 

H2C-CHV--NH  HC^N-N 

The  five-  and  six-membered  compounds  are  much  more  numerous- 

and  important  than  the  three-  and  four-membei'ed, 

B.  Condensed  compounds,  containing  two  or  more  rings,  usnall^ 
five-  or  six*meinbered,  of  which  at  least  one  is  heterocyclic,  fused 
together,  and  having  two  carbou  atoms  in  common.  These  com- 
pounds, which  correspond  to  the  condensed  benzeuic  compounds 
(p.  493),  include  the  indole,  quinolin,  anthraquinolin,  quinuquinoliu, 
and  diphenylene  derivatives, 

C.  Compounds  containing  two  (or  more)  nuclei,  one  at  least  hete- 
rocyclic, united  directly  without  fusion,  corresponding  to  the  di- 
phenyls,  and  iuL-luding  phenyl- pyridyl,  dipjTidyl,  pyridyl- pyrrole ♦ 
and  pjTidyl-piperidyl  derivatives. 

D.  Compounds  containing  two  (or  more)  nuclei,  one  at  least 
heterocyclic,  united  by  aliphatic  groups,  corresponding  to  the 
diphenyl- paraffins,  and  including  the  ^*  ester* alkaloids"  such  as 
atropin,  cocain,  etc. 

In  a  more  detailed  classification  the  members  of  the  several  classses- 
are  subdivided  into  the  groups  of  mono-,  di-,  tri-,  and  tctrahetero- 
atomic  compounds,  according  as  they  contain  one,  two,  three  or  four 
atoms  other  than  carbon,  of  like  or  different  kinds,  in  the  ring. 


HETEROCYCLIC    COMPOUNDS 


509 


A,— MONONUCLEATE  HETEROCYCLIC  COMPOUNDS. 


FIVE    MBMBEHED  RINGS. 

The  parent  substances  of  these  compounds  ai^e  fnrfnrane.  thio- 
phene,  and  pyrrole*  (see  p.  508). 

The   heterocyclic  rings  differ  from   the   carbocyclic   in  that  the 
»Tera]  carbon  atoms  ai'e  not  equal  in  value,  and  therefore  two  dif- 
ferent   nioDosnbstituted   deriva- 


rHC 

II 
HC 


-CH^ 


CH 
O 


H 
C 

^'HC  CH^ 

II  I 

HC  CH 

a'\    /a 

N 
Pyrldin. 


tives  exist  for  the  five  membered 

rings  containing  a  single  hetero- 

atom»    such   as   fnrfnrane,    and 

three   such    compounds    in    six 

membered  rings,  such  as  pyri- 

din,  according   to   the   position 

of   substitution    with    reference 

to  the  hetero-atom.     These  positions  are  distinguished  by  the  first 

three   letters   of  the  Greek  alphabet,  as  shown  iu   the  margin,  or, 

sometimes  by  numbers.      The  positions  «  and  ^\  and  ^  and  js'  are 

of  equal  value. 

HC— CHv 

Furluranc-^    I  yO — exists  in  the  product  of  distillation  of 

HC=^CH^ 

pine  and  fir  wood,  and  is  also  formed  by  distillation  of  barium  pyro* 

HC — CHjv 

mucate  (below),  and  from  dihydrofurfurane,     II  ^0»  a   product 

He — CHj 

of  reduction  of  erythrol  (p.  297).  It  is  a  liquid;  b.  p.  32°  (89,6"* 
Fj;  having  a  peculiar  odor.  Its  vapor  colors  a  pine  shaving  moist- 
ened with  HCl  green  (pp.  445,  510). 

HC=C-CHO 
tt-Furf  uraldchyde — Furfurole — Forole —     I      """^^    ^Is  produced 

HC^CH— O 

by  the  dry  distillation  of  sugar  or  of  wood;  by  the  distillation  of 
these  substances,  or  of  bran,  carbohydrates  or  glucosids  with  dilute 
H2SO4;  by  the  action  of  the  concentrated  acid  upon  carbohydrates; 
and  by  distilling  pentoses  (p.  323),  or  gluouronic  acid  (p.  348)  with 
HCL  It  is  a  colorless  liquid;  agreeable  in  odor;  b.  p.  162^; 
soluble  in  water  and  in  alcohoL  Being  an  aldehyde,  it  undergoes  the 
reactions  common  to  those  substances.  In  concentrated  solution, 
with  urea  and  a  trace  of  acid,  it  is  colored  yellow,  changing  to  blue, 
to  violet  and  to  purple,  and  finally  fading,  with  formation  lyf  a  black 
precipitate  (Schiff's  reaction).  It  produces  a  red  color  with  anilin,  a 
very  sensitive  reaction  for  its  presence.     Paper  moistened  with  anilin 


*Th«  ttittji.1  apelllnB  is  pjttoI,  furfqroL  fndnl.    The  tonnlDal  » 1i  nmed  beojia»  thoit  labitBDMC 
mr*  neither  iileoholi  nor  pbenoli,  for  whoia  nainei  the  t«riiilii«non  ol  ie  retenred. 


Pyrrole — ^|    ^   ^NH — exists  in  coal-tar  and  accompanies   the 


510  MANUAL    OP    CHEMISTRY  ^ 

acetate  solution  is  used.    Pettenkofer's  reaction  for  the  biliary  salts, 
etc.,  depends  upon  the  formation  of  furfurole. 

HC=:C--COOH 
a-Furfuranc  Carboxylic  Acid — Pyromucic  acid —    I      "^^ —      — 

HC^CH— O 

the  acid  corresponding  to  furfurole,  is  produced  from  that  substance 
by  oxidation,  also  by  distillation   of   mucic  and   isosaccharic   acids 
(p.  346).     It  is  a  solid;  f.  p.  134°  (273.2°  P.). 
HC=CH. 
Thiophene —    I         j)S — and   its   superior   homologues,  methyl- 

thiophenes,  etc.,  occur  in  gas- tar,  and  accompany  the  various  prod- 
ucts, benzene,  etc.,  obtained  from  it.  It  is  a  colorless  liquid;  b.  p. 
84°  (111.2° P.);  which  is  so  nearly  that  of  benzene,  80.6°,  that  the 
two  substances  cannot  be  separated  by  distillation.  With  sulfuric 
acid  and  isatin  it  gives  a  fine  blue  color,  due  to  formation  of  indo- 
phenin.  Sulfuric  acid  alone  is  colored  brown  by  thiophene,  which  it 
absorbs;  and  thiophene  may  be  recovered  from  the  solution  by  neu- 
tralization and  distillation. 
HC=CHv 

HC=CH 

pyridin  bases  (p.  517)  in  oil  of  Dippel.  It  is  formed  in  a  grreat  variety 
of  reactions,  as  by  the  action  of  baryta  at  150°  (303°  F.)  upon 
albumins,  by  the  dry  distillation  of  gelatin  or  of  ammonium  saccha- 
rate,  etc.  It  is  a  colorless,  oily  liquid,  having  the  odor  of  chloro- 
form; b.  p.  131°  (267.8°  P.).  Being  a  secondary  amin,  it  has  basic 
properties,  and  its  imid  hydrogen  is  readily  replaced  by  other  atoms 
or  groups.  A  pine  shaving  moistened  with  HCl  is  colored  flame -red 
by  pyrrole  (the  pine-shaving  reaction;  see  also,  Phenol,  p.  445).  It 
also  yields  an  indigo -blue  color  with  H2SO4  and  isatin.  Heated  with 
dilute  acids  it  gives  off  ammonia,  and  a  red  powder  (pyrrole  red)  is 
deposited.    • 

The  homologous  pyrroles,  methyl -pyrroles,  etc.,  have  reactions 
similar  to  those  of  pyrrole. 

Haemopyrrole  —  CgH^N  —  probably    a    methyl    propyl    pyrrole, 

^      ~\ 
H7C3.C  -CH 

coloring -matter  (p.  664),  and  of  chlorophyll  derivatives.  It  is  an  oil 
sparingly  soluble  in  water,  having  a  faecal  odor,  and  gives  a  strong 
pyrrole  reaction.  On  exposure  to  air  it  soon  turns  red,  apparently 
with  formation  of  urobilin. 

Haematinic  Acids — C8H9NO4  and  CgHgOs — are  derivatives  of 
haemopyrrole,  the  former  an  imid  and  the  latter  an  anhydro  acid, 
both  monocarboxylic. 

Pyrrole  and  its  homologues  form  series  of  substitution  products: 


H3C.  C=CH 


^NH,  is  a  product  of  reduction  of  derivatives  of  the  blood 


FIVE    MEMBEHED    IIETEROfYCLIC    RIN'GS 


511 


I 

r 


I 


• 


haloid,  nitro*,  azo-,  carboxylic,  etc.  Among  these  is  tetriodo pyrrole, 
or  iodol,  CJ4NH,  formed  as  a  brown  powder  by  acting  upon  pyrrole 
with  an  ethereal  solution  of  iodin,  and  used  in  surgery  as  a  sub- 
stitute for  iodoform,  over  which  it  has  the  advantage  of  being 
odorless. 

Hydropyrrolc    Derivatives — Nascent    hydrogen    combines    with 

CH  :CH 
pyrrole  to  form*  first  dihydropyrrole,  or  pyrrolin,  1  yNH»    an 

alkaline  liquid,  soluble  in  water;  b.  p.  91°;  and,  finally,  tetrahydro- 

pyiToletOr  pyrrolidin,  or  tctrametbylene-imin,   I  yNH,  which 

CH2.CH2 

bears  the  same  relation  to  pyrrole  that  piperidtn  does  to  pyridin 
(p*  519).  Pyrrolidin  resembles  piperidin  in  its  reactions,  and  also 
forms  an  addition  product  with  methyl  iodid.  It  is  formed  by  heating 
tetramethyleue-diamin  hydrochlorid  (p.  386)  :H2N.{CH2)4.NH2:HC1  = 
NH4OH- (0112)4: NH,  and  constitutes  the  nucleus  of  the  hygrins 
(p.  548)  and  one  of  those  of  nicotin  (p,  551).  It  is  a  strongly  alka- 
line liquid;  b.  p.  87*^.    Among  the  derivatives  of  pyrrolidin  is  pyrroli- 

done,  or  butyrolactam,  I  ^)NH,  a  simple  cyclic  imid  derived  from 

Y-amidobutyric  acid  (p,  414). 

a  Pja-ollidin  Carboxylic  Acid— Prolin — is  a  product  of  hydroly- 
sis, by  HCl  or  by  tryptic  digestion,  of  casein  and  gelatin,  in  which  it 
probably  exists  as  a  dipeptid,  constituted  by  substitution  of  the  radi- 
cal of  a-aniido-isocaproic  acid  for  the  imid  hydrogen  of  the  cyclic 
compound: 


HjC 


^CH.CHa*CH.CO.N<f 


HaN  HOOC 


/ 


I 
CHj.CHi' 


This  com  pond,  leucylprolin^  has  been   obtained  synthetically  from 
-pyi'ollidin  carboxylic  acid  and  a-bromisoeapronyl  chlorid  (p,  416). 


AZOLES    AND    THEIR     DERIVATIVES. 


H  The  azoles  are  derivable  from  furfurane,  thiopheiie  and  pyrrole 

H    by  substitution  of  one  or  more  N  atoms  for  methine  groups  in  the  five 

H    memhered  ring.    They  are  distinguished,   according  to  their  parent 

"    substances,  into  furazoles,  thioazoles,  pyi^oazolcs  and  selenazoles, 

there  being  nine  possible  of  each  class,  or  they  may  be  considered  as 

derived  from  pyrrole  by  snbstitutifm  of  further  hetero  atoms  in  the 

ring.    They  are  further  distinguished  as  monazolcs,  diazolcs,  tria- 

2olc8  and  tctrazoles,  according  to  I  lie  number  of  introduced  N  atoms. 

Thus  the  formulae  of  pyrrole  and  of  the  nine  pyrroazoles  are: 


S12 


BiANUAL    OP    CHEMISTRY 


HC CH      L4]HC CH[3]       HC N 

II         II 
HC        CH 

\    / 

N 
H 


[5]HC        Nb] 

N[i] 
H 


Pjrrol6. 


N- 


-N 


HC       CH 
\    / 

N 

H 
i3-/S'-Diaw)le. 


o-Monaxole. 

HC N 

II  II 

N        CH 

\   / 

N 

H 

a^-/9-Diazole. 


HC        CH 

\   / 

N 

H 

/3-Moiiazole. 


HC N 

II  II 

N        N 

\    / 

N 

H 

a'-a-/3-Trlaw>le. 


HC CH 

II         II 

N        N 

\   / 

N 

H 

a-a^-Diuole. 

N N 

II         II 

N        CH 

\    / 

N 

H 

tt-/S-/S'-Trlarole. 


HC ^N 

II  II 

HC       N 

\   / 

N 

H 

a-/^DiMole. 

N N 

II         II 

N       N 

\    / 

N 

H 
Tetruole. 


Corresponding  to  each  of  these  compounds  there  are  numerous 
derivatives,  formed  by  substitution,  or  by  modification  of  internal 
linkages  and  addition. 

Monazoles. — The  monazoles,  containing  N  and  one  other  hetero 
:atom  in  the  ring,  which  are  known  are:  two  furomonazoles  (N  and 
O),  a  and  P,  two  thiomonazoles  (N  and  S),  a  and  P,  two  pyrromon- 
azoles  (N  and  N),  a  and  P,  and  one  selenmonazole  (N  and  Se),  P. 
In  the  a- monazoles  the  two  hetero  atoms  are  in  adjoining  positions,  as 
in  a-monazole  above;  and  in  the  /3-monazoles  they  are  separated  by 
a  C  atom,  as  in  ^-monazole  above.  The  azolesof  medical  interest  are 
the  two  pyrromonazoles  and  their  derivatives. 

Pyrro-<i-monazolc  —  Pyrazole  —  is  obtained  by  starting  from 
acetyl  acetone  and  hydrazin  hydrate,  which  by  condensation  yield  3, 
5-diraethyl  pyrazole  :  CH3.CO.CH2(CO.CH3)+ H2N.NH3OH  = 
^N C.CH3 


HN 


C(CH3):CH 


I         +3H2O.     This  is   then  oxidized  to  3,    5 -pyrazole 


-dicarboxylic  acid,  which  is  decomposed  by  heat  to  pyrazole  and  car- 
bon dioxid.  It  forms  crystalline  needles,  f.  p.  70°,  soluble  in  water, 
alcohol  and  ether,  has  the  odor  of  pyridin,  is  bitter,  neutral,  and  a 
weak  monacid  base. 

The  positions  of  substituted  groups  in  the  derivatives  of  pyrazole 
are  indicated  by  numbers,  beginning  with  the  imid  N,  as  shown  in 
the  formula  of  a-monazole  above.  The  most  important  of  these 
-derivatives  are  antipyrin  and  its  congeners. 

Pyrazole  is  reduced  by  sodium  to  dihydrop3rrazole,  or  pyrazolin 
(formula  below),  corresponding  to  which  are  three  types  of  ketonic 
■derivatives,  or  pyrazolonSi,  one  of  which  contains  a  single  imid  N, 
the  others  two  each. 


HC— CH 

HoC— CH 

H2C— CH 

HC=CH 

HC— CO 

II      II 

i      II 

1       II 

1      1 

11       1 

HC     N 

H2C     N 

OC     N 

OC   NH 

HC    NH 

\  / 

\/ 

\/ 

\/ 

\/ 

N 

N 

N 

N 

N 

H 

H 

H 

H 

H 

Pyrazole. 

Pyrazolin. 

I.  Pyrazolon 

II.  AntipyriB 

ni.  laopynxolon 

type. 

type. 

type. 

FIVE    MEMBEBED    HETEROCYCLIC    RINGS 


513 


The  pyrazoloiis  are  obtained  from  tlu*  hydrazoues  (p,  485)  of  tlie 
esters  of  the  ^  ketone  acids  {p.  360)  by  elimiimtioD  of  alcohol,  or  by 
the  action  of  phenylhydraziu  upou  these  esters  theujiselves.  Tims 
l-phcnyl-3-methyl-pyrazolon  La  formed  either  from  phenylhydra- 
zooeacetoacetic  ester: 


COOCCsHs) 

CH, 

I 
C:N.NH.C«H« 

CHs 


HjC        C  .CHa 


OC       N 

\    / 

N 
CnHs 


CaHfi.OH 


or  from  aceto- acetic  ester  and  phenylhydrazin: 


COOlCaH* 


HsC- 


CHa 

I 
CO 

CH, 


HiN.NH.CH*       ^ 


i.CHs 


OC        N 
\    / 
N 
CflHs 


+      CHs.OH+HjO. 


H        Antipyrin — l-Phenyl-2;3-dimcthyl   Pyrazolon  — (fonnnla  below) 

W — is  formed,  us  its  hydroiodid,   by  heating  1,  S-pheuylinethyl  pyra- 

xoloti,  formed  by  the  seeond  reaetioii  given  above,  with  methyl  iodid 

and  niethylic  ah*ohol   to   lOif  (212'^   F.)   in  seided  vessels.     In  this 

^      reaction  the  I-pyrazolou  type  is  maintained  in  the  pTOduct  of  addi- 

H  tion,  but  on  splitting  off  HI  to  liberate  the  free  base  the  antipyrin 

iyi>e  is  produced: 


HtC  —  C.CH3 

!       II 
OC       N 

\/ 

N 

l-pb*iiyl-3-iji*thyl 
pjfmzoloii. 


H2C  -  C.CHt 

I     11  /CH3 
OC     N>r 

N 
C.H5 

lodoEDiethsrlAtQ. 


HC  ^  C.CHi 

I         I 
OC        N,CHj 

\  / 

N 

CflHa 
Antlpyrtii, 


Antipyrin  forms  colorless,  odorless  scales,  somewhat  bitter  in  taste; 
f,  p,  110.5*^  (230,9°  FJ.  A  mixture  of  equal  parts  of  autipyrin  and 
antifebrin  (f.  p.  112.5°)  fuses  at  45''  {113"  F,).  Antipyrin  is  readily 
soluble  in  water,  alcohol  and  chloroform,  less  soluble  in  ether.  With 
nitrous  acid  or  the  nitrites  (sp,  a^tli.  nitr.),  in  the  presence  of  free 
acid,  it  forma  a  green,  crystalline,  sparingly  soluble  nitro -derivative, 
which  is  poisonons.  Its  solution  is  colored  deep  red* brown  by  Fe2Cl6, 
the  color  being  discharged  by  H^SO*.  Nitrous  acid  colors  its  solutions 
bright  green,  and  on  heating  tiie  mixture,  ufter  addition  of  a  drop 
of  fuming  nitric  acid,  the  color  changes  to  light-red,  then  to  blood- 
33 


5U  MANUAL    OP    CHEMISTRY 

red,  and  finally  a  pnrple  oil  is  deposited.  Addition  of  a  drop  d 
fuming  nitric  acid  to  cold,  concentrated  solution  of  antipyrin  caiues 
precipitation  of  small,  green  crystals.  Antipyrin  is  strongly  basie, 
and  some  of  its  salts  are  used  in  medicine:  Salipyrin  is  antipyrin 
salicylate.  It  is  formed  by  the  action  of  the  acid  and  the  base  upon 
each  other  at  100®  (212°  P.).  It  is  a  white,  crystalline  powder, 
almost  insoluble  in  water. 

Toljrpyrin  —  1-toluyl-  2,  3 -dimethyl  p3rrazolon  —  is  obtained  ia 
the  same  manner  as  antipyrin,  using  p-toluyl-hydrazin  in  place  of 
phenyl -hydrazin,  and  contains  toluyl,  CeHi.CHa  in  place  of  phenyl. 
It  forms  colorless  crystals;  f.  p.  136°  (276.8°  F.);  and  has  a  physio- 
logical action  similar  to  that  of  antipyrin. 

Pyrro  -^-  monazole  — ^-Pyrazole — Imidazole  —  Glyoxalin  — (for- 
mula below) — contains  the  group  N.C.N,  which  is  also  met  with  in 
urea  and  in  pyrimidin  and  its  derivatives  (p.  521).  Of  the  several 
known  methods  of  its  formation,  the  simplest  is  by  heating  glyoxal 
(p.  306)  with  ammonia  and  formic  aldehyde:  CHO.CHO+2NH3+ 
.CH:N 


H.CHO=HN<^  ^  J[^+3H20;    or,  similarly,  from  glyoxal  and  am- 


^CH:CH 

monia  alone,  in  which  reaction  part  of  the  glyoxal  is  first  hydrolysed 
to  formic  acid  and  formic  aldehyde:  CH0.CH0+H20=H.C00H-1- 
H.CHO.  Glyoxalin  forms  pearly  plates,  soluble  in  water  and  in 
ether,  f.  p.  89°,  strongly  alkaline,  and  having  a  faint  fishy  odor. 

The  orientation  of  the  substitution  products  of  glyoxalin  and  of 
its  di-  and  tetrahydro  derivatives  is  indicated  by  letters  or  numbers 
as  shown  in  the  formula)  below,.  The  n  alkyl  and  phenyl  glyoxalins 
are  the  best  known  of  the  simpler  derivatives,  and  are  more  strongly 
basic  than  the  corresponding  pyrazole  compounds.  The  two  possible 
dihydroglyoxalins  and  tetrahydroglyoxalin  are  known  only  in  their 
derivatives : 

/3HC  —  Na     [4]HC  —  N[3]  HzC  —  NH  HC  —  NH  HjC  —  NH 

11         11                 II         II                   I           I  11          I                        II 

7HC        CHfi  [6]HC       CH[2]  H2C        CH  HC        CH2  HjC         CH, 

\/                   \/                   \/  \/                        \/ 

N                         N                         N  N                              N 

H"                       H[i]  H                              H 

QlyoMlin.  a-Dihydroglyoxalins-^  Tetrahydio- 

(Olyoxalidins).  slyoxalin. 


Lysidin,— /A-Methyl-a-glyoxalidin— N\^  _         J^_  ,    is    obtained 


^C(CH3).NH 
T^  I 

^CH2 CH,' 

by   heating   diacetylethylene   dianiin:     (CH3.CO)HN.CH2.CH2.HN.- 

(C0.CH3)=  I  ^C.CHs+CHa.COOH,  or,  to  better  advantage,  by 

heating  ethylene -diammonium  clijorid  with  sodium  acetate  (p.  385). 


FIVE    ilEMBERED    HETEROCYCLIC    RINGS 


515 


> 


I 


It  Ls  a  deliquescent »  crystalline  solid,  f.  p.  105*^,  which  forms  crystal- 
line  salts  with  acids.  Its  urate  is  the  most  soluble  known  coropotind 
of  uric  acid,  being  soluble  in  6  pts.  of  water* 

Among  the  ketohydroglyoxalins  are  some  which  are  derivatives 
of  urea  or  of  uric  acid: 

Hydantoln^  —  Glycolylurea  -*-  2,  5*dlketotetrahydrogiyoxalin  — 
(formula  below)  is  the  siraplest  of  the  cyclic  naonureids  (p.  406) »  and 
is  formed  by  the  action  of  HI  upon  allantoTn,  or  upon  alloxan ie  acid. 
It  is  converted  into  the  corresponding  open  chain  compound,  liydau- 
toic,  or  glycoluric  acid,  HjN  CO.NH.CH2.COOH,  by  heating  with 
BaHaOj.  .^.^ 

Corresponding  to  hydantoin  are  a  number  of  substituted  hydan- 
toms,  constituted  by  substitution  of  alkyls  for  H  in  the  several  posi- 
tions. The  ^- compounds  are  formed  by  heatiuj?  the  monoalkyl  amido- 
acids  with  urea.    Thus  urea  and   sareosln  yield  ^'metliyihydantoin; 


HiN.CO.NH2+CH2(NH.CH,).COOH=HN 


CO.N.CHa 

I 
CO.CHa 


+  NH3+H2O. 


HaC  —  NH         HaN.CO.NHHC  —  NH        HO.HC  —  NH        OC  —  NH 


I  I 

OC       CO 

\  / 

N 
H 

Hjrd&tiioTii. 


OC  CO 

\   / 

N 
H 

Allatitotn. 


I  I 

OC        CO 

\  / 

N 
H 

Allntittirie  licid. 


f  I 

OC        CO 

\  / 

N 

H 


AUantoVn,  —GlyoxyJdiurcid^( formula  above) — ^a  derivative  of 
hydantoin,  occurs  in  the  allantoic  fluid  of  the  fow,  in  the  urine  of 
mucking  calves,  of  dogs  and  cats  fed  on  meat,  of  children  during  the 
ftrst  few  days  of  life,  of  adults  after  adrahiistration  of  tannin,  and  of 
pregnant  women;  also  in  beet  juice.  It  is  also  formed  during  autoly- 
sis of  pancreas,  liver  and  spleen.  It  is  obtained  by  oxidation  of  uric 
acid  by  lead  peroxidr  20fiH4N40:.+2n20+02-=2C|H6N403+2C03,  or, 
RyntheHcally  from  glyoxylic  acid  and  nrear  CHO.COOH+2H2N.CO.- 
>CO.NH 

NH3=HN<       I  +2H2O. 

It  crystallizes  in  prisms,  sparingly  soluble  in  cold  water,  readily 
soluble  in  hot  water  and  in  alcohol.  On  reduction  by  HI  it  yields 
hydantoin  and  urea.  Healed  with  alkalies  it  is  decomposed  into  am- 
monia and  carbonic,  oxalic  and  acetic  acids;  glyoxylic  acid  being  prob- 
ably first  formed  and  decomposed.  Warmed  with  BaH202,  or  with 
PbOi,  it  splits  off  urea  and  forms  allanturic  acid  (formula  above), 

Oxalylurea,— Parabanic  Acid— 2,  4,  5-triketotetrahydroglyoxalin 
—  (formula  above)  is  formed  by  oxidation  of  nrie  acid  or  of  alloxan 
hy  HNO3;  or  synthetically  by  the  action  of  POCb  or  PCI3  on  a  mix - 
tnr©    of    oxalic    acid    and    urea:     COOH.COOH  +  HsN.CO.NHz^ 


516 


MANUAL    OF    CHEMISTRY 


HN 

by 


CO.NH 


CO.CO 


I    +2H2O.    Its  salts  are  converted  into  oralurates  (p* 


water. 

Histidin — CfiH»N302 — one  of  the  bexon  bases  (p.  417),  is  pro- 
duced by  hydrolysis  of  proteins.  It  crystallizes  in  rhombic  plates  or 
needles,  sparingly  soluble  in  water,  insoluble  in  alcohol  and  ether, 
dextrorotary.  It  is  only  faintly  alkaline,  but  expels  CO2  from  A^ 
and  Cn  carbonates.  By  oxidation  by  KaMuaOg  in  alkaline  solution 
yields  HON,  CO2  and  NRa,  but  it  is  not  attacked  by  KiMnoOg+H-SOi 
When  boiled  with  BaH^Oa  it  does  not  give  off  NH3.  It  does  not  giv^ 
the  biuret  i-eactiou.  It  contains  two  H  atoms  replactuible  by  metala 
and  it  forms  two  series  of  salts  with  acids.  Nitrous  acid  separates  one 
N  atom  as  free  nitr-ogeu,  and  it  forms  one  substitution  product  with 
/3- naphthalene  sulfonic  acid;  but  two  of  its  N  atoms  are  capable  of 
salt  formation.  It  therefore  contains  one  NH2  and  one  NH,  and  thf 
third  N  is  tertiary.  When  heated  it  gives  off  CO2,  and  leaves  a  com! 
pound  CsfliXa.KHa,  and  therefore  it  contains  a  COOH.  The  small 
proportion  of  H  indicates  a  closed  chain  nucteus»  and  its  reactions, 
indicate  two  double  linkages  in  the  ring.  It  gives  the  Weidel  reaci 
tion  faintly  (p,  524).  When  diazobenzenc- sulfonic  acid  (CoHs.NiNt 
SO3H,  or  sulfauilic  acid  and  KNO2:  the  diazo  reaction,  p.  743)  ifl 
added  to  a  solution  of  histidin  in  Na2C03,  a  coloring  matter  is  formed 
which  is  orange  in  acid  solution  and  dark  cherry -red  in  alkaline  solu- 
tion. The  only  other  product  of  protein  hydrolysis  w^hich  gives  this 
reaction  is  tyrosin  (p.  478).     Histidin  is  a  derivative  of  glyoxalin, 

„CH.NH 

whose  constitution  is  probably  N 


1 


N;H  :C.CH,XHNHa.COOH' 


SIX    MEMBERED    RINGS. 


4 


Six    membered    heterocyclic   compounds 
oxygen,  sulfur  and  nitrogen  in  the  nucleus: 


are   known,   containing ^ 


H  Hi 

C  C 

^   \  /   \ 

IC          CH  HC          C.CH3 

I           II  II            II 

XI          CH  HC          CH 

\   /  \   / 

O  8 

ft-Prron*.       ^-M«tb;lpetithloph«n«. 


H 
C 

/  \ 

HC  CH 

II  I 

HC  CH 

\   / 
N 

Pyrldln. 


H, 

C 

/   \ 

HaC  CHt 

I  I 

HfC  CHj 

\    / 

N 
H 

Piperidin. 


The  oxygen  and  sulfur  compounds  are  neither  numerous  nor  i'^' 
portant.  Some  of  the  former  are  products  of  condensation  of  di' 
phatic  com  pounds,  8*  lactones  and  S*anhydrids  (p.  368)* 


SIX    MEMBEBED    HETEROCYCLIC    RINGS 


517 


Pyrone  (y}—Pyrocomane-Os^^^^^^J^CO—i&  an  oxidized  deriva- 
Kto  of  7  furane,  produced  frora  comenic  acid  by  the  action  of  heat 
constituting  the   nucleus   of  comenic,  chelidonic»  and  meeonie 

Comenic  acid— CsH202(OH).COOH— is  produced  by  the  action 
Df  hot  H2O,  of  dilute  acids,  or  of  broniin  water  upon  nieconic  acid. 
It  crystallizes  in  yellowish  prisms,  rather  soluble  in  H2O.  It  is  mono- 
basic.   It  is  decomposed  by  heat  into  CO2  and  pyrone. 

Chelidonic  acid — C5Hl>02(€OOH)'j  — exists  in  ehelidonium,  m 
combination  with  the  alkaloids  sangutnarin  and  chelidonin.  It  is  a 
crystalline  solid  and  a  dibasic  acid.  Heat  converts  it  into  comenic 
acid,  which  in  turn  yields  pyrone. 

Meconic  acicl--'C5H02(OH){COOH)2 — is  peculiar  to  opium,  in 
which  it  exists  in  combination  with  a  part,  at  least,  of  the  alkaloids. 
It  crystaJlizes  in  small  prismatic  needles ;  acid  and  astringent  in 
taste;  loses  its  Aq  at  120*^  (24B^  P.);  quite  soluble  in  water,  soluble 
in  alcohol,  sparing^ly  soluble  in  ether. 

With  ferric  eh  lorid  it  forms  a  blood -red  color,  which  is  not  dis- 
charged by  dilute  acids  or  by  mercuric  ehlorid;  but  is  discharged 
by  stannous  ehlorid  and  by  the  alkaline  hypochlorites. 

PYEIDIN    BASES    AND    THEIR    DERIVATIVES, 

The  pyridin  bases,  closely  related  to  the  vegetable  alkaloids  (p, 
545)  as  well  as  to  some  of  the  basic  substances  formed  during  putre- 
faction, were  first  obtained  from  oil  of  Dippcl,  or  bone-oil  (Oleum 
unimale),  an  oil  produced  during  the  dry  distillatiou  of  bones,  horns, 
etc*,  and  as  a  by-product  in  the  manufacture  of  ammoniaeal  com- 
ponnds  from  those  sources.  They  also  occur  in  coal-tar,  naphtha, 
commercial  ammonia,  methylie  spirit  and  fusel  oil.  They  are  formed 
gynthetically  :  (  1  )  By  heating  the  aldehyde -ammonias  (p.  409) 
alone,  or  with  aldehydes  or  ketones;  (2)  Prom  pyrrole  by  the 
action  of  K  or  Na  in  presence  of  methylene  iodid,  etc;  (3)  By 
oxidation  of  hexahydro pyridine,  piperidins;   also  by  other  methods. 

The  pyridin  bases  are  colorless  liquids  of  peculiar,  penetrating 
odor.  The  superior  homologues  are  metameric  with  the  anilins. 
They  are  strong  triacid  bases,  and  behave  like  tertiary  monarains. 
Oxidizing  agents  do  not  attack  pyridin,  nor  the  nucleus  of  its  supe- 
rior homologues,  but  the  lateral  chains  of  the  picolins,  etc.,  are 
readily  oxidized,  with  formation  of  carbopyridic  acids.  Reducing 
agents  convert  them  into  piperidins  (p.  519),  They  react  with  sev- 
eral of  the  general  reagents  for  the  alkaloids  (p.  548).  The  two 
most  nearly  characteristic  properties  of  the  p>Tidin  bases  are:  (1) 
the  formation  of  chloroplatinates  such  as  (C5H5N.HCl)2PtCl4,  which 


518  MANUAL    OP    CHEMISTRY 

on  boiling:  with  water,  lose  two  molecules  of  HCl  to  form  "modified 
salts''  such  as  (C5H5N)2PtCU  (Anderson's  reaction),  and,  (2)  the 
formation  of  crystalline  addition  products,  alkyl-|)3nridinium  iodids, 

such   as   CsHsN^i    '  on    contact    of   their   alcoholic   solutions  with 

alkyl  iodids. 

/CH'CH\ 

Pyridin — HC^^h.CH^^ — ^^  obtained  from  oil  of  Dippel,  or 
from  piperidin.  It  boils  at  115°  (239°  F.),  mixes  with  water  in  all 
proportions,  is  strongly  alkaline  in  reaction.  Its  hydrochlorid  is 
crystalline,  but  deliquescent.  Its  chloroplatinate  fuses  at  240°  (464*^ 
F.).  When  reduced  by  sodium  and  alcohol,  it  forms  piperidin,  or 
hexahydropjrridin ;  and  when  reduced  by  hydriodic  acid,  normal 
pentane,  CH3.CH2.CH2.CH2.CH3. 

Pyridin  Homologues — Alkyl  Pyridins  —  are  substitution  prod- 
ucts containing  alkyl  groups  for  H.  Owing  to  the  inequality  in 
value  of  the  several  G  atoms  of  pyridin  (p.  509),  the  number  of 
substituted  derivatives  is  greater  than  with  benzene.  There  are  three 
mouosubstituted  derivatives,  six  each  of  the  bi-  and  tri* substituted, 
three  tetra-,  and  one  penta- substituted. 

Methyl-pyridins — Picolins — C5H4N(CH3) — The  three  pioolins, 
a,  fi  and  7,  exist  in  oil  of  Dippel,  and  have  been  formed  synthetically. 
Their  b.  p.'s  are  130°,  143°,  and  144°. 

Lutidins  —  Three  ethyl  pyridins,  C5H4N(C2H5),  are  known,  ^ 
b.p.  148°,  ^,  b.p.  166°;  and  7.  b.p.  165°.  Of  the  six  possible 
dimethyl  -  p3rridins,  C5H3N(CH3)2,  four  are  known,  three  of  which 
exist  in  bone  oil. 

Collidins  —  CsHnN  —  There  are  twenty -two  possible  collidins,  of 
which  twelve  are  known.  Of  these  several  are  products  of  decom- 
position of  vegetable  alkaloids,  or  exist  in  oil  of  Dippel,  or  are  pro- 
duced during  putrefaction.  Conjrrin,  a  basic  substance  produced  by 
boiling  coniin  (p.  549)  with  ZnCU,  is  a-propyl-pyridin.  /9-propyl- 
pyridin  is  produced  from  nicotin  by  passing  its  vapor  through  a 
red-hot  tube.  Aldehydin  is  1,  4-methyl-ethyl-pyridin,  formed  by 
heating  aldehyde -ammonia  in  alcoholic  solution  to  120°  (248°  F.). 
and  from  other  aldehyde  compounds;  and  exists  also  in  the  products 
of  rectification  of  alcohol.  An  oily  ptomain  produced  during  putre- 
faction of  gelatin  in  presence  of  pancreas  is  a  collidin  of  undetermined 
constitution. 

Parvolins  —  CgHisN.— Theory  indicates  the  existence  of  57  par- 
volins,  of  which  five  are  known.  One  of  these  is  a  ptomain,  produced 
during  putrefaction  of  mackerel  and  of  horse-flesh.  It  is  an  oily 
substance,  slightly  soluble  in  water,  having,  when  fresh,  the  odor  of 
hawthorn -blossoms,  but  becoming  brown  and  resinous  on  exposure 
to  air.  ;.^. 


SIX    MEMBERED    HETEKOCYCLIC    RINGS 


519 


Coridins— CioHir.N. — Out'  of  the  eoridins  lias  been  obtained  as 
a  product  of  putrefaction  of  fibrin  and  of  jellyfish  during  several 
months.  It  is  an  alkaliue  oil,  which  has  a  poisonous  aetion  similar 
to  that  of  curari.  The  pyridin  bases  in  general  exert  a  paralyzing 
action  upon  the  central,  and  to  a  less  degree  npon  the  peripheral 
nervous  system.     The}"  are  the  antagonists  of  strychnin. 

Besides  the  alkyl-pyridins  a  number  of  phcnyl-pyridins  (p,  545) 
and  pyridins  containing  unsaturated  lateral  chains,  such  as  vinyl- 
pyridin,  CsHiNCC^Hi),  are  known. 

Pyridin  Carboxylic  Acids. — These  acids,  which  bear  the  same 
relation  to  pyridin  that  the  benzoic,  phthalic,  etc.,  acids  bear  to 
l>eazene,  are  formed  by  oxidation  of  the  alkyl-pyridins.  As  moat  of 
the  alkaloids  contain  pyridin  nuclei  with  lateral  chains,  they  yield 
pyridin -carboxylic  acids  upon  sufficient  oxidation.  Thus  pyridin- 
^-monocarboxylic  acid,  or  ^-picolinic  acid,  C&H^NCCOOH),,),  is  nico- 
tinic acid,  formed  by  oxidation  of  nicotin,  of  pUocarpin,  as  well  as 
of /3-picolin.  The  «  acid  is  formed  by  oxidation  of  a-picolin.  The 
-y  acid,  isonicotinic  acid,  is  formed  by  oxidation  of  S-pieolin,  and  of 
many  of  its  derivatives.  Pyridin- 1,  2- di carboxylic  acid,  C5H3N- 
(COOH )>,,.,>,  is  qoinolinic  acid,  formed  by  oxidation  of  quinolin, 
mud  pyridin -2,  S-dicarboxylic  acid  is  cinchomeronic  acid,  formed 
fcy  oxidation  of  einchonin,  cinchonidiu  and  qninin. 

Hydropyridins  —  Pipcridins  ^^  are  compounds  produced  from  the 
pyridins  by  the  action  of  nascent  hydrogen.  Four  isomeric  dihy- 
'^iropyridins  are  known  in  their  derivatives:  M-a;  /?-y;  a.0;  and  «-y. 
Of  the  several  tetrahydro pyridins  whose  existence  is  possible  the  best 
bnowti,  in  its  derivatives,  is  the  *i«  compound,  called  piperideln, 
"^rhich  polymerizes  readily  to  dipipcridein  with  splitting  out  of  the 
x^maining  double  linkage.    It  is  a  split  product  of  the  betel  alkaloids. 

Piperidin  —  Hcxahydropyridin  —  H2C  \ch^;ch!  )  NH  —  which   is 

produced  by  saponification  of  piperin  (p.  550)  by  heating  with  alco- 

liolic  KHO,  and  is  also  formed  by  reduction  of  pyridtn,  or  by  heating 

't>€ntametbyleBe-diamin  hydrochloride     It  is  a  colorless  liquid;   b.  p, 

106°   (222.8°   P.);    having  an   odor  like   that  of  pepper;    readily 

«olnble   in   water   and   in   alcohol.      Oxidizing   agents    rupture   the 

piperidin  ring,  with  formation  of  aliphatic  compounds.     When  heated 

^th   methyl   iodid    is  converted    into   methylpiperidio   hydroiodid, 

Piperidin  and  methyl -piperidin  are  particularly  of  interest  as 
l)eing  the  nuclei  of  a  number  of  vegetable  alkaloids.  Thus  coniin  is 
ttpropyl-pipcridin,  and  tropin  and  ecgonin,  the  basic  nuclei  of  the 
atropie  and  eocaln  alkaloids,  are  derivatives  of  methyl -piperidin 
(gee  pp.  552,  555). 


520 


MANUAL    OP    CHEMISTRY 


AZINS    AND    TitElR    DERIVATIVES. 

The  azins  are  compounds  bearing  the  same  relation  to  pyridin  that 
the  azoles  bear  to  pyrrole  (p,  511).  i.  e.,  they  are  derived  from  pyri- 
din by  substitution  of  further  hetero-atoms  in  the  ring.  Oxygen, 
sulfur  aud  nitrogeu  are  the  only  elements  known  to  enter  into  such 
ring  formation .  When  bnt  one  hetero*atom  exists  in  the  ring  in 
addition  to  the  pyridin  N,  the  substance  is  a  derivative  of  an  oxazin 
if  it  be  O,  of  a  thiazin  if  it  be  S,  and  of  a  diazin  if  it  be  N;  aud 
there  are  three  of  each  class, — ortho,  meta  and  para.  Nuclei  also  exist 
containing  more  than  two  hetero -atoms,  O,  S,  or  N»  in  a  six  mem- 
bered  ring»  and,  as  these  may  be  like  or  unlike,  such  compounds  ar^H 
very  numerous  and  of  great  variety. 

The  oxazins  aud  thiazlns  are  only  known  in  their  derivatives.   All 
azins  enter  into  the  constitution  of  condensed  nuclei  with  benzenifl 
and  with  each  other,  particularly  the  paraoxazins  and  the  parathiazins,^ 
which  occur  in  highly  complex  nuclei,  which  may  consist  of  as  many 
as  seven  rings,   in  compounds  used  as  blue,   violet,   red  and  black 
dyes,    such   as   naphthol-bloe,   Nile-blue*    Lauth's    violet,  thionyl » 
black,  the  safranins  and  indulins,  methylcne-blue,  etc.  H 

Thionin,  or  Lauth's  violet^  is  the  p-amido  derivative  of  a  three- 
ring  nucleus,  the  middle  of  which  is  parathiazin:  H«2N,CeH3x^j^^Cfl* 
Ha,NH2,  p-amido  thiazin.  The  tetraniethyl  dtrivntive  of  this,  as  its 
chlorid,  is  methylenc-blue :  (eH3)2N,C«H3<^|^K'flH3:N  ^(CHsJaCl. 
which  is  formed  by  the  oxidation  of  dinietbyl-p-pheuylenediamiu, 
H2N.C«H4,N(CH3)2,  by  FetjCU,  in  H2S  solution.  A  blue  powder,  spar- 
ingly soluble  in  water,  which  is  used  as  a  dye,  as  a  bacterial  stain, 
and  medicinally  as  an  antipyretic  and  antiperiodic.  ^ 


A  tetrahydro-paraoxyazin    ring  also  exists  in   morphin  and    m ' 

a  product  of    their 


O 


CH,.CHA 


\CH,.CH2X 


NH, 


codein,  and  in  morpholin 
decomposition.  | 

Diazins,  —  There  exist  three  isomeric  diazins— ortho,  meta  and 
para — which  are  thin  colorless  oils,  soluble  in  water,  ah.'ohol  and, 
ether,  insoluble  in  petroleum  ether,  neutral  in  reaction 


H 

H 

COOM 

H 

C 

C 

N 

C 

N 

/4%. 

/4\ 

/\ 

/\ 

/\ 

HC5     3CH 

HC5    3N 

HC       CH 

HCK)C,C       CH 

HaC       CHi 

II          1 
HC6    2N 

II          1 
HC6    2CH 

II        1 
HC       CH 

11         1 
HC       N 

H2C       CHj 

V 

\1^ 
N 

N 

M 

V 

H 

OrthwllMlm. 

Metudiuln. 

ParR^iuiD. 

HexAhydro* 

*  Pyridlaiia. 

Pyrimmn. 

Fyrniiji, 

dWrboxyUc  odd. 

SIX    HEMBERED    HETEKOCYCLIC    KINGS 


521 


Orthodiazin — Pyridiazin— is  obtained  by  beating  the  4,  5-dicar- 

l)oxylic  add  {formuliB  p.  520):  b4H2N2(COOH)2^C4H4N2+2C02, 
which  is  itself  obtaioed  from  the  tetracarboxylic  acid,  a  product  of 
oxidation  of  pheuazone  (below),  It  has  a  pyridin-like  odor,  b*  p. 
208"'.    Forms  an  insoluble,  erystalliae  compound  with  AuCla. 

Metadiazin— Pyrimldin— is  obtained  by  starting  from  4 -methyl- 
uraeiL  This  is  first  converted  by  POCb  into  4* methyl -2,  ti-diehlor- 
pyrinjidin,  which  is  then  reduced  by  ziuc  dust  to  4-methylpyrimidin, 
which  is  then  oxidized  to  the  carboxylic  acid,  and  this  is  decomposed 
by  heat  into  pyrimidin  and  carbon  dioxLd; 


CHa 


CHs 


CHa 


COOH 


H 


C 
HC       NH 

C                       G 

/  \         y  \ 

HC       N            BC       N 

C 

/\ 

HC       N 

C 

/  \ 

HC       N 

1         1 
OC       CO 

\  / 

N 
H 

f-jnethyl. 

->       II         1      ->     II         1 
CIC       CCI         HC        CH 
\^                 \^ 

N                      N 

-->      !!       1 
HC       CH 

V 

>        II         1 
HC       CH 

V 

4-methyl"2,  fl-           ♦-mothyl- 
dlchlorf^rlmldin.        pyrimidin. 

Pyrimiditi-4- 
(^arboxylJc  aeid. 

PiHmi^iii, 

The  free  base  is  an  oil,  b,  p.  124^,  having  a  penetrating,  narcotic 
odor,  which  forms  a  nitrate  and  a  liydrochlorid,  both  of  which  are 
completely  volatile  below  100*^.  It  forms  crystalline  compounds  with 
HgCUt  AuCb,  and  picric  acid,  but  not  with  CuSOi. 

Paradiazin^Pyrazin — is  obtained  by  condensation  of  amido  acet- 

aldehyde  by  mercuric  chlorid:  2H2NCH2,CHO+2HgCl2=N<^eH:CH/^ 
+  Hg2Cl2+2HCl+2H20,  It  has  a  faint  heliotrope  odor.  B.  p.  118°. 
Frotji  concentrated  aqueous  solution  it  deposits  crystals,  f.  p,  53° » 
which  are  extremely  volatile.  It  forms  a  crystalline  compound  with 
CuSO*.  Pyrazin  and  its  homologues  are  produced  during  ferinenta- 
tion,  and  exist  in  fusel  oils  and  in  eomniereial  aujylic  alcohol. 

The  three  diazins  form  condensed  products  with  benzene,  the 
benzorthodiazins:  cinnolin  and  phthalazin,  the  benzometadiazins 
and  the  benzoparadiazlns,  all  eonstitnted  by  the  fusion  of  one  ben- 
zene and  one  diazin  ring;  and  also  products  of  further  condensation, 
containing  a  greater  number  of  rings,  such  as  phenazone; 


H        H 

H        H 

C         C 

C         C 

H     H              H 

H 

^\  /  \ 

/\  ^\ 

c=c          c  = 

=  C 

HC        C        CH 

HC        C        N 

/    \     / 

\ 

1          If         1 

1          1         II 

HC             C-C 

CH 

HC         C        N 

HC        C        N 

\       ^        \ 

^ 

%  /  \^ 

\/%  / 

C-C             C 

^C 

C         N 

C         C 

H      \       / 

H 

H 

H        H 

N=N 

CinnoiJn. 

Phtlifctazin. 

Pb«tift«oiie. 

522 


MANUAL     OF    CHEMISTRY 


From  these,  as  well  as  from  the  diazhis  themselves,  many  com- 
pouiiils  are  derived  by  substitution,  aud  by  breaking  out  of  double 
linkages  and  addition.  The  derivatives  of  orthodiazin  and  of  para- 
diazin  are  not  of  present  medical  interest ♦  except  the  following:  fl 

Hcxahydro-pyrazin — Piperazin — Diethylene  IHamin —     I  I 

H^CCHa.NH 

— may  be  obtained  by  reduction  of  para-diaziu,  but  is  manufactured 
from  diphenyl-diethylene  diamiu,  C©H5.N<^(^*H!!cHa/^'*-'«^^'  which  is 
obtaiut^d  by  the  actiou  of  ethyleue  bromid  upon  anilin.  It  crystallizes 
in  nolorless  needles;  f.  p.  104"^;  b.  p.  145*^;  soluble  in  water,  aud 
deliquescent.  It  is  strongly  alkaline  and  basic,  and  absorbs  carbon 
dioxid  from  air.  It  forms  a  soluble  compound  with  uric  acid  and  isj 
used  niediciually  as  a  solvent  for  uric  acid  in  lithiasis. 

Kcto-  or  Acipiperazins  are  ketonie  derivatives  of  piperazin,  ani 

HN.CH2.CO 
auhydrids  of  the  monamido  acids.    2,  S-Diacipiperazin,      I  I    , 

glyeoeoll   anhydrid  (p.  412).    It  is  obtained  by  evaporation   of  ai 
aqueous  solution  of  glycocoll  ester:  2CH2N  H2.  COO  (Calif,  )=CiH6N20i1 
+2C2H5.OII.  It  crystallizes  in  plates,  sparingly  soluble  in  water,  faintly 
basic.    This  aud  other  Hcipiperazins  yield  polypeptide  on   bydratioD 
(p.  415).    The  leucinimid  obtained  by  decomposition  of  albumins  by! 
acids  and  by  tryptic  digestion  of  globiu,  is  3,  6-dibutyl-2,  5-diacipi- 

HN  CH(C|Ho).CO 
perazin.  or  leucin  anhydrid,     I  I    ,  which  on  hj^dratiou  opens 

to  the  dipeptid  leucylleucin,  C4H0  CHXH2.CO.NH.CiHB.COOH.  f 

Pyrimidin  Derivatives*^ — The  pyrimidin,  or  myazin  compounds 
which  are  of  medical  interest  are  not  referable  directly  to  pyrimidin, 
or  metadiazin  itself,  but  to  the  hydropyrimidins  (formula  p.  523),  of 
%vhicb  they  are  ring  ketone  derivatives,  most  of  which  contain  the 
gi^ouping  N.CO.N,  which  also  exists  in  urea.  They  include  uric  acid 
and  its  derivatives,  the  xaiithiu  bases,  and  most  of  the  cyclic  ureids 
(p.  406).    They  are  divided  into  two  groups:  h 

I.  Compounds  containing  a  single  hydropyrimidin  ring,  more  arij 
less  modified  by  snbstitntiou.  This  class  iuclndes:  (a)  The  uracil  X" 
group,  {h}  The  malonylurea  group,  (e)  The  guanids. 

II.  The  purin  group. — Compounds  containing  a  hydropyrimidvxar 
nucleus  with  a  glyoxalin  ring  fused  upon  it.    These  compounds  won. !♦- 
be  more   properly  classified  among  the  condeused  heterocyclic  cotxT 
pounds  (p.  537),  but  are  more  conveniently  considered  here. 

The  positions  of   orientation   in  the    pyrimidin    ring   have   be< 
designated  in  several  different  ways,  which  has  led  to  no  little  co^m  - 
fusion.     The  notation  which  will  be  adopted  here  is  that   in  whi<^A 
numbers  are  used,  and  in  which  the  two  nitrogen  atoms  occupy  tli< 


:j 


SIX    MEMBERED    HETEROCVOLtO    RINGS 


523 


I 


1  and  3  positions,  us  in  tho  folkiwitig  fornniltr  i>f  [\viitijiiliu  auil  t»f 
mraeil: 


H(4)  H 

C  C 

/  \  /  \ 

(5}HC         N(3)         HaC         N 
II 


C 


H 
C 

HC'       NH       HnC         NH 

I  I..        „   I  L 


(6)HC         CH{2)      HjC         CH  H.C         CHj  HjC         CH, 

\^                      \^  \/                 \/ 

N                           N  N                       N 

(1)  H                        H 

pyrimWIn.  pyriinidlo.                pirJmUUn. 


(UHN— C0(6) 

I  I 
(2)OC    CH(5) 

I  II 
r3)HN-CH(4) 


2,  6-M«Dlketotet- 
ralijrdropyriijj' 
i<Iln  ( Uracil) 


While  the  above  hexagonal  expressions  are  most  in  conformity 
with  those  of  other  e>eli<j  t-omponndsi,  and  are  on  that  ground  prefer- 
able  to  the  quadrilateral  expression  of  the  f*>rmula  of  uraeij,  the 
latter  form  was  adopted  for  the  uiiieyl,  urie  acid  and  xanthin  deriva- 
tives before  their  relationship  to  pyrimidiu  was  recognized,  and  have 
since  come  into  such  universal  use  that  we  feel  reluctantly  cum  pel  led 
to  make  use  of  them  for  these  rum  pounds* 

I  a.  The  Uracil  Group. — Tiie  physiologically  interesting  members 

of  tbis  group  are  2,  6-diketo  derivatives  of  the  unknown  tetraliydn> 

pyrimidiu,  sometimes  referred  to  as  oxypyrimidin  derivatives,  a  term 

"whieb  more  properly  applies  tu  eon i pounds  containing  a  phefioiic  or 

siecoDdary  alcoholic  OH  as  a  lateral  chain. 

Uracil — C4HtN20'2~2,  6- ^  4-dikctotetrahydropyrimidin— was  fiist 
obtained  as  a  product  of  decomposition  of  yeast -nucleic  acid,  and 
Xater  from  other  nucleic  acids.  It  is  also  formed  from  thymin  in 
^mtolysis  of  pancreas^  and  is  probably  widely  disseminated  in  animal 
organisms.  It  has  been  obtained  synthetically:  Hydrounieil,  the 
^corresponding  hexahydropyrimidin  derivative,  is  first  obtained,  either 
Mj>t  heating  together  urea  and  /^-amidopropionic  acid:   H2N.CO,XH2+ 

UN. CO,  NH 
€Z7B,NH2.CH2.COOH=    I  I      +NH:j  +  H30,    or,    more     readily, 


and 


acrylic     acid 


H2N.C0.NHa+CHa:CH.C00H= 

This  latter  reaction  constitutes  a  general  method 


^«-om     urea 
^  1^*C0,  NH 

.r^  I        +H20 

OC.CH3.CH, 

c*^  ftvnthesis  of  uracil  derivatives,  starting  from  various  unsaturated 
^<^id8,  known  as  Fischtti"  and  Roeder*s  method.  The  hydrnuraeil  is 
tl^en  converted  into  a  bromin  derivative,  which  is  debrorainated  by 

HN.CO.NH 

^ytiain:    C4H;iN202Br+C5Hr,N=    I         \    +Ciai5NHBr.     Another 

OC.CHrCH 

'^tieral    method   of   synthesis  of   the  uracil   compounds   is   that   of 

W^heeler  and  Johnson,  based  upon  the  fact  that  alkylpseudotliioureas 

'1^.  406)  readily  condense  with  ketonic  acid  esters  (p.  360)  to  furm 


524 


MANUAL    OF    CHEMISTBY 


alkylmercaptoketopjTimidins,  which  are  split  by  boiling  with  HCl  of 
HBr  to  ketopyriinidins  and   iiiercaptau.     Thus  etbylpseudothioureaj 
and  sodium  formylauetic  ester  (p.  362)  condense  to  2-etliyliuercapto- 
C-ketopyrimidin,    which    is  decomposed  by  HBr  to  uracil  and  mer- 

captan:    HN;C\^?=^„ +Na0.CH;CH.C00(O2HrJ=     I  I 

HN.C(S*CiHjt):N  HN.CO.NH 

+C2H5.0H+NaHO,and  I  I    +H20=    I         I     +C1H5.SH. 

CO  CH ^-CH  OC.CH:CH 

Uracil  crystallizes  in  rosettes  of  needles,  easily  soluble  in  hot 
water,  difficultly  in  cold  water,  almost  insoluble  in  akohol  and  ether, 
easily  sohil>le  in  ammonia.  It  does  not  form  compounds  with  HCl  or 
HNOa,  nor  a  ppt.  with  phosphotuii^stic  aeid.  With  AgfNOa  alone  it 
does  not  ppt.,  but  on  addition  of  NH4HO  a  gelatinous  ppt.  is  formed, 
soluble  in  exeess.  It  also  forms  a  ppt.  with  Hg{N03)2.  It  gives  the 
Weidel  reaction,  which  consists  of  the  production  of  a  red  or  purple 
color  when  chlorin  water  and  a  trace  of  HNOh  are  evaporated  with 
the  substaiiee,  and  the  residue  is  exposed  to  ammonia.  This  reaction, 
is  characteristic  of  certain  pyrimidin  compounds  (see  Xanthin,  p.  o32). 
Two  niethyluraeils  are  knowu. 

4-Mcthyluracil — (formula  p.  525) — the  earliest  known  of  the  ura- 
cil compounds,   is  formed  by  the  condensation  of  acetoacetie  ester] 

HN.CCNH 
with  urea;    CH3.CO.CH2.COO(C2H5)+H2N.CO.NH2^     I         I        + 

OC.CHiC.CHa 

CsHr,.0HH-H20,  a  reaction  which  constitutes  one  of  the  steps  in  a 
synthesis  of  uric  aeid  (p.  529),  It  ia  also  formed  by  Fischer  and 
Roeder's  method  by  starting  from  crotonic  acid,  CH:i,CH:CH*COOH; 
and  by  Wheeler  and  Johnson^s  method  by  starting  from  methylpseu- 
dothiourea  and  acetoacetie  ester.  It  crystallizes  in  needles  from  hot 
water,  and  is  difficultly  soluble  in  alcohol.  It  dissolves  in  NaHO  or 
KHO,  forming  crystallizable  salts.  By  further  methylation  it  yields 
dimethyl*  and  trimethyl- uracil.  It  also  forms  chlorin,  nitro,  amido 
and  phenyl  derivatives,  and  carboxylic  acids. 

Thymin^ — 5 -Methyluracil  — (formula  p,  525) — is   a  product  of 
decomposition  of  thymus -nucleic  acid.    It  is  formed  synthetically  by: 
Fischer    and    Roeder's    method,    starting    from    methylacrylic    acid,  ( 
CH2:C(CHa).CO0H;   and  by  Wheeler  and  Johnson's  method,  start- 
ing from    methylpsendothiourea   and  sodium  formylpropionic  esler,] 

HaCy^^-^O^H.  It  crystallizes  in  quadratic  or  six-sided  prisms; 
fuses  and  sublimes  at  250°;  is  difficultly  solnble  in  cold  water,  easily 
in  hot  water,  less  soluble  in  alcohol  and  ether.  It  is  neither  dis- 
tinetly  acid  nor  basic.  Its  aqueous  solution  ppts.  with  Hg(N03)2;  with 
HgC]2  only  after  addition  of  NaHO  to  slight  alkalinity,  and  with  AgNOi 
only  after  addition  of  NHiHO.    It  decolorizes  bromin  water,     Oo 


SIX    MEMBERED    nETEROCYCLIC    RINGS 


525 


nitration  and  subsequent  reduction  it  jields  a  compound  which  gives 
the  Weidel  reat^tiou.    It  is  pptd.  by  pluKspbotungstie  aeid. 

4-PhcnyluraciI-"CjH3N2i>2.CijH5— is  formed  by  condensation  of 
urea  and  bciizoyliicetie  ester,  CH2(C0,CGH:,)XX>0(Cin:.) ;  by  Fischer 
and  Boeder's  method^  titartiiig^  from  eitinamic,  or  /3-phenyhierylic 
aeid.  CH(CoHa):CtLCOOH;  and  by  Wheeler  and  Johnson's  method, 
starting  from  methylpseudothionrea  and  sodium  beiizoylacetate.  5- 
Phenyluraeil  is  also  known. 

Cytossn  —  6  -  amido  -  2-keto  -  ^  4,  6-dihydropyrimidin — (formula 
below) — obtained  from  thymus -nueleic  acids,  herring  and  sturgeon 
melt,  pan<.*reas,  yeast  and  wheat,  is  not  properly  a  uraeil  derivative, 
as  it  does  not  contain  two  CO  groups,  and  it  is  a  dihydro  pyriniidin, 
nut  a  tetrahydropyrimidin^  derivative.  It  is  obtained  synthetically  by 
Wheeler  and  John  son  ^s  method:  2*ethylmereapto-G-ketopyrimidin  is 
obtained  as  described  above  (uraeil).  This  is  then  converted  by  PCU 
into  2-ethyiraercapto-6-chlorpyrimidin,  which  with  alcoholic  animo- 

N.C(S.e,H5);N 
Ilia  produces 2-ethyln3ercapto-6-amidopyrimidin:    II      _  L+N- 


CChCH- 


=CH 


It 


N.C(S.C3H6):N 

I  Ha=tl  I     +HC1,  and  this  is  split  by  HBr  into  eytosin  and 

^m      CNH2,CH=-CH 

■  N.C(S.Cam):N  N.CO.NH 

■reaptan:   II  I     +H20=-         II         I    +C2avSH, 

■^  CNH3.CH=CH  HjN.CCHiCH 

Cytosin  crystallizes  in  pearly  plates,  difficnltly  soluble  in  water. 

forme  a  hytlrobromid,  cldorophitinate,  picrate,  nitrate  and  two 
sulfates,  which  are  all  crystalline.  It  is  pptd.  by  phosphotungstic 
acid,  by  AgNOa,  and  by  BaH'202  in  excess.  It  gives  the  Weidel  reac- 
tion, although  it  contains  but  one  CO.  Nitrous  acid  converts  it  into 
uracil;  C4Hr,N30+HN02=^(Ml4N202+No+H20,  asguanin  is  converted 
into  xanthin,  and  adcnin  into  hypoxantbin  (p.  534).  When  oxidized 
by  BaMnaOi*  it  yields  biuret  and  oxalic  acid:   U4H5NnO+H20 4-202^= 

The  relations  of  the  uracils  and  eytosin  are  shown  in  the  follow^- 
ing  formulflB: 


HN— CO 

I      I 
OC    CH 

I      II 
HN-CH 


-CO 

I 
CH 


HN- 

I 
OC 

I 
HN-C.CHa 

4'Methyliirftr'tl. 


HH^CO 

t        I 

OC    CXHs 

I      II 
HN-CH 

ThTniln. 


N==C.NHa 

I      I 
OC 


CH 


I 


HN— €H 


Jb.  The  Malonylurea  Group* — The  members  of  this  group  are  tri- 
or tetraketo-hexahydropyrimidin  compounds,  all  of  which  are  deriva- 
ble from  malonylurea  by  substitution  in  the  CH2  group  of  malonie 
acid  (see  malonie  esters^  p.  361).  The  three  principal  members  of 
the  group  are: 


526,  MANUAL    OP    CHEMISTRY 

HN-CO  HN— CO  HN-CO 

II  II  II 

OC    CH2  OC    CHOH  OC    CO 

II  II  II 

HN-CO  HN— CO  HN— CO 

Malonylorea.  Tartronylurea.  Metozalylorea. 

Malonylurea  —  Barbituric  Acid  — 2,  4,  6-Triketohexahydropy- 
rimidin — C4H4N2O3 — is  produced"  by  the  action  of  POCI3  upon  a  mix- 
ture of  urea  and  malonic  acid:  3H2N.CO.NH2+3COOH.CH2.COOH 

HN.CO .  NH 
+2POCl3=3    I  I    +2POiH3+6HCl.    It  is  also  formed  by  the 

OC.CH2.CO 

action  of  concentrated  H2SO4  on  alloxantin  (p.  527).  It  crystallizes 
with  4  Aq.,  is  efflorescent,  sparingly  soluble  in  cold  water,  readily 
soluble  in  hot  water.  It  behaves  as  a  dibasic  acid.  It  is  decomposed  by 
boiling  alkalies:  C4H4N203+3H20=COOH.CH2.COOH+2NH3+C02. 
In  malonylurea  the  hydrogen  atoms  of  the  CH2  group  exhibit  the 
same  mobility  that  they  do  in  malonic  ester  (p.  361),  and  are  replace- 
able by  sodium,  which  is  in  turn  replaceable  by  alky  Is.    Thus  dime- 

thylmalonylurea,  OC<^j^j£.CO/^(^^3)2,  may  be  produced  either  by 
the  successive  action  of  Na  and  CH3I  upon  malonylurea,  or  by  the 
action  of  POCI3  upon  urea  and  diraethylmalonic  acid.  The  last 
named  acid  is  produced  when  dimethylmalonylurea  is  hydrolysed  by 
KHO.    Dimethylmalonylurea  is  isomeric  with  malonyldimethylurea, 

OC<(n(CH3);co/CH2,  obtained  by  the  action  of  POCI3  upon  malonic 

acid  and  dimetliylurea.  Diethylmalonylurea,  0C<^J^h'(-q^C(C2H5)2, 
is  similarly  obtained,  and  has  been  used  as  a  hypnotic  under  the 
name  veronal. 

The  following  derivatives  of  malonylurea,  also  produced  by  sub- 
stitution in  the  CH2  group,  are  of  interest  in  connection  with  a  syn- 
thesis of  uric  acid  (formulae,  p.  529):  Nitromalonylurea,  formed  by 
the  action  of  fuming  HNO3  upon  malonylurea,  behaves  as  a  tribasic 
acid.  Amidomalonylurea  is  formed  by  the  reduction  of  nitromalonyl- 
urea by  HI.  It  yields  murexid  (p.  527)  when  boiled  with  ammonia; 
and  is  converted  into  alloxan  (p.  527)  by  nitrous  acid.  It  is  the  par- 
ent of  a  number  of  derivatives,  called  uramils,  constituted  by  substi- 
tution of  alkyls  for  the  amid  or  imid  hydrogen.  Pseudouric  acid» 
which  differs  from  uric  acid  by  +H2O,  is  formed  by  heating  amido- 
malonylurea with  urea  at  180°,  or,  as  a  salt,  by  heating  urea  with 
potassium  cyanate.  By  dehydration,  by  heating  with  oxalic  acid  to 
145°,  or  by  boiling  with  concentrated  HCl,  it  is  converted  into  uric 
acid.  Methylpseudouric  acids  are  obtained  similarly  from  the  corre- 
sponding uramils,  and  serve  for  the  synthesis  of  methvlxanthins 
(p.  533). 


SIX    MEMBERED    HETEROCYCUC    RINGS 


627 


Tartronylurea—  Dialuric  Acid — 2,  4>  6-tnketo-5-oxyhcxahydro- 
pyrimidia^ — C4H4N2O4 — h  produced,  aluii^r  witii  oxjihirit^  aekl  (p.  408) , 
by  reduetiou  of  alloxan,  it  containing  a  secondary  alc*oliolic  group  in 
the  5  position,  where  alloxan  contains  a  k».*tone  gronp  (formulae 
526)*  It  is  converted  by  nitrons  acid  into  allantoin  (p,  515),  By 
cposure  l"o  air  and  nioistnre  tartronylurea  forms  alloxantin,  C^jsH^Ni* 
J7,  in  whieh  rec^etion  probably  one  mulecule  of  tartrouylorea  is  oxi- 
dized to  alloxan,  whicli  eondeuses  with  a  second  niolecnle  of  tartronyl- 
urea. AUoxantin  is  also  formed  by  reduction  of  alloxan,  and  by 
oxidation  of  uric  acid.  It  forms  sparins:ly  soluble  erystals,  whieh 
turn  red  on  exposure  to  air.  Murexid  is  the  animonimn  salt  of  the 
unknown  purpuric  acid,  CgHaNrjOe,  derived  from  alloxantin  by  sub- 
stitution of  NH  for  O,  and,  like  that  substance,  containing  two 
hydropyrimidin  nuclei.  It  is  produced  by  heating  alloxantin  with 
NH3,  or  by  evaporating  nitric  acid  on  uric  acid,  and  adding  ammonia 
to  the  residue  (murexid  test,  p.  530),  The  product  of  the  Weidel 
reaction,  in  which  chlorin  water  with  a  trace  of  HNO3  is  used  as  an 
oxidant  (p.  524),  is  also  probably  murexid,  Murexid  crystallizes  in 
ehort,  red  prisms,  having  a  greenish  reHection,  and  forming  a  red 
powder  when  ground.  It  is  difficultly  soluble  in  cold  water,  insoluble 
in  alcohol  and  ether. 

Alloxan — Mesoxalylurea — 2,  4,  5,  6-Tetraketohexahydropyrimi* 
din — L'4H3N204 — is  a  product  of  the  limited  oxidation  of  uric  acid, 
alloxantin,  or  murexid.     Uric  acid  oxidized  by  dilute  HNOy  at  60°  to 


ENCO.C.NH 


70    yields  alloxan  and  urea:       I 


CO+HaO+O^     I 


HN.CO.NH 


OC.NH.C.NH^  OCXO.CO 

+  H2N,OO.NH2.  It  has  been  found  in  the  intestinal  mucus  in  diar- 
rhoea. It  fornts  priitmatic  crystals,  readily  soloble  in  water»  which 
turn  red  in  air,  are  acid  in  reaction,  and  stain  the  skin  red.  Reduc- 
ing agents  convert  it  into  alloxantin;    and  by   oxidation  it  yields 

HN.CO.NH  HN.CO. 

oxahlurea:       I         I    +0=    I       ^NH  +  COj.     When    heated   with 

BallsOs  the  cyclic  nucleus  is  broken,  and  alloxanic  acid  is  formed: 
HK.CONH 

I         I    +H20==H2N.CO.NH.CO.CO.COOH. 
OC.COX'O 

le.  The  guanids  are  derivatives  of  malonylguanid,  which  is 
2-imido-4,  6-dikctohexahydropyrimidin,  and  is  formed 
by  the  interaction  of  guanidin  and  malonic  ester;   COO- 

/NH3      HN,CfNH).NH 
(C^5).CH2.COO(O^Ir.)+HN:C<        --     I     ^  I     + 


HN— 00 
I      I 
HN.C    CHa 

I      I 
HN— CO 


KEt       OC.CH2  — CO 

2C2Hf^.OH.    The  derivatives  are  formed,  as  are  those  of 
malonic  ester,  and  of  nmlonylurea,  by  substitntion  in  the  CH:;  gnmp. 
11.  The  purin  group. — ^The  compounds  of  this  group,  which  in- 


528  MANUAL    OF    CHEMISTRY 

eludes  uric  acid,  the  xanthin  bases,  caffeiu,  etc.,  are  derivatives  of 
purin,  whose  molecule  consists  of  a  pyriinidin  ring,  with  a  glyoxalia 
ring  fused  upon  it  at  the  4  and  5  positions: 

HC NH 

II  C  N=CH  (1)N=CH(6) 

II        ^  \  II  II 

N— C  N  HC    C N  (2)HC    C(5)— NH(7) 

Hi  ^H         "'         li     1  >H        -  II     II-  >H(8) 

%   /  N— C— NH  (3)N— C(4) N(9) 

N 
the  last  of  which  is  the  formula  now  generally  adopted. 

Some  of  the  derivatives  are  referable  to  purin  itself,  others  to  th^^^" 
methylpurins,  in  which  CH3  is  substituted  for  H  in  one  or  more  0:^^ 
the  positions,  2,  6,  8,  and  7  or  9. 

Purin — C5H4N4 —  is  obtained  by  starting  from  uric  acid  (1).   Thi^^ 
is  converted  by  POCI3,  first  into  8-keto-2,  6-dichlorpurin  and  therr»- 
into  2,  6,  8-trichlorpurin  (2).    By  the  action  of  HI  and  PHJ  this  i^^- 
converted  into  2,  6-diiodopurin  (3),  which  by  boiling  with  zinc  in  ai:^ 
atmosphere  of  CO2  yields  purin  (4) : 

HN-CO  N=CC1  N=CI  N=CH 

II  II  II  II 

00    C.NHv  010    O.NHv  10    C.NHv  HC    C.NHv 

I      II         >C0  II      II         >C01  II      II        >H  II     II        >CH 

HN~C.NH^  N— C.N-^  N— 0  .  N  ^  N— C.N^ 

(1)  (2)                               (3)  (4) 

Purin  crystallizes  in  small  needles,  f.  p.  212°,  very  soluble  iwr»- 
cold  water  and  in  warm  alcohol.  It  is  neutral  in  reaction,  but  form  ^ 
salts  with  both  acids  and  bases.  Its  solutions  ppt.  with  AgNO^^  « 
phosphotungstic  acid  and  tannin;  not  with  KI,  Nessler's  reagent  o  "■" 
K4Fe(CN)6.  It  withstands  oxidizing  agents.  Its  reaction  with  Br  i  ^ 
characteristic;  in  its  solution  in  concentrated  HCl,  Br  forms  a  fim  ^ 
reddish  yellow,  crystalline  mass,  soluble  on  warming,  and  crystalli^^" 
ing  again  on  cooling. 

Uric  Acid — Lit  hie  Acid — 2,6,8-Triketopurin — (formula  1,  aboveJP** 

C5H4N4O3 — occurs  in  the  urine  of  man  and  of  the  carnivora,  in  con *' 

bination,  chiefly  as  its  disodic  salt;  in  the  urine  of  the  herbivera,  i  -^ 
which  ordinarily  it  is  replaced  by  hippuric  acid,  when,  in  early  li^^*^ 
and  during  starvation,  they  are,  for  the  time  being,  practically  cac  ^' 
nivora;  in  some  urinary  calculi,  in  the  so-called  "chalky  deposits,"  c=^'' 
"tophi,"  in  the  joints  of  the  gouty;  very  abundantly  in  the  excr^^*" 
tions  of  serpents,  tortoises,  birds,  molluscs  and  insects,  and  S^n 
guano;  in  smaller  amount  in  the  blood  and  tissues.  It  is  be^^^ 
obtained  from  guano  or  from  the  solid  urine  of  serpents,  which  co^""^- 
sists  almost  entirely  of  ammonium  urate. 

Uric  acid   is  obtained  synthetically:    (1)    From  monochloracet /^ 


i 


SIX    MEMBERED    HETEROCYCLIC    RINGS 


529 


acid  and  urea.  Monochloracetic  acid  is  converted  into  malonic  acid 
(p.  337);  this  is  then  condensed  with  urea  to  malonylurea  (p.  526, 
and  5  below) ;  this  by  HNO3  to  nitromalonylurea  (6) ;  this  by  reduc- 
tion to  amidomalonylurea  (7) ;  this  by  condensation  with  urea  to 
pseudouric  acid  (8) ;   and  this  by  dehydration  to  uric  acid  (9) : 


H2N 

I 

oc 

I 

H,N 


COOH 

I 

CHa  > 

I 
COOH 


HN-CO 

I  I 
OC    CH.NHa 

I  I 
HN-CO 

(7) 


HN— CO 

OC    CH2         — > 

I      I 
HN— CO 

(5) 

HN— CO 

I      I 
OC    CH.NH.CO.NH2 

I    I 

HN-CO 

(8) 


HN— CO 

I       I 
OC    CH.NOa 

I       I 
HN-CO 

(6) 


HN— CO 

I       I 
->  OC    C.NHv 

I     II       >co 

HN— C.NH^ 
(9) 

<2)  Prom  acetoacetic  ester  and  urea:  4-Methyluracil  is  first  obtained 
from  acetoacetic  ester  and  urea  (p.  524,  and  10  below) .  By  the  action 
of  fuming  HNO3  and  H2SO4  this  is  converted  into  the  5-nitro-4-car- 
boxylic  acid  (11);   this  by  heat  to  5-nitrouracil  (12);   this  by  reduc- 
tion to  a  mixture  of  5-amidouracil  (13),  and  5-oxyuracil,  or  isobar- 
bituric  acid  (14) ;   the  former  of  which  is  converted  into  the  latter  by 
<JiIiate  acids.    By  oxidation  with  bromin  water  5-oxyuracil  yields  4,  5- 
dioxyuracil,  or  isodialuric  acid  (15),  which  in  presence  of  concen- 
trated H2SO4  condenses  with  urea  to  uric  acid  (16) : 


HN- — CO 

OC       CH   - 

^^ C.CH3 

(10) 

aN^ — CO 

^       C.OH 


HN— CO 

I      I 
OC    C.NO2    — 

I   II 

HN-C.COOH 
(11) 

HN— CO 

I      I 
->         OC    C.OH 

I      II 
OC— C.OH 

(15) 


EN— CO 

I      I 
OC    C.NO2 

I   II 

HN— CH 
(12) 


HN— CO. 

I      I 
OC    C.NH2 

I   II 

HN— CH 

(13) 

HN— CO 


-f 


H2N 
H2N 


CO 


OC    C.NHv 

I    II      >co 

HN— C.NH^ 
(16) 


C3)  From  amidoacetic  acid  and  urea,  by  heating  glycocoU  with 

^^^esfi  of  urea  to  200^-230°:  3H2N.CO.NH2+CH2NH2.COOH= 

**^-C0.C.NHv 

cJ^  .     II       >CO+2H20+3NH3. 
^^.NH.C.NH/ 

When  pure,  uric  acid  crystallizes  in  small,  colorless,  rhombic, 

^^tangular  or  hexagonal  plates,  or  in  rectangular  prisms.    As  crys- 

^llized  from  the  urine,  it  is  more  or  less  colored  by  the  urinary  pig- 

^^Hts,  and  the  angles  of  the  crystals  are  rounded  to  produce  lozenge 

^*^«fcpe8,  which  are  arranged  in  bundles,  crosses  or  daggers.   It  is  very 


530 


MANUAL    OF    CHEMISTRY 


sparinifly  soluble  in  water,  requiring  36,480  parts  of  pure  water  for 
its  solotion  at  18°*    In  ordioary  distilled  water  it  is  more  soluble^  1: 
15,000  cold,  aud  1:1,900  boiling.    It  is  soluble  in  1,900  parts  of  a  2 
per  cent  solution  of  urea,  insoluble  iu  alcohol  and  ether.    Cold  HC'l 
dissolves  it  more  readily  than  water,  aud  on  standing  deposits  it  iu  j 
colorless  rectangular  plates.    Its  aqueous  solution  is  acid  to  litmus,' 
but  tasteless  and  odorlt^ss,'  It  nhi*  dissolves  unchanged  in  concen- 
trated H2SO1,  and  is  depositt^d  from   the  solution  on   dilution    with, 
water.    It  dissolves  in  KHO  and  NaHO  solutions  with  formation  of| 
urates. 

Uric  acid  is  decomposed  by  heat,  yielding  as  final  products  ammo- 
nia, earbou  dioxid,  urea  and  hydrocyanic  and  cyanuric  acids.     Nas- 
cent hydrogen  reduces  it  to  xauthiu  (p.  532).     With  CI,  Br,  or  I  at 
ofdiiiary  temperatures  it  forms  oxalic  and  parabanie  acids,  alloxan 
and  ammonium  cyanate.     Heated  with  CI  it  yields  cyanuric  acid  and 
HCL    It  dissolves  iu  cold  HNO3,  with  effervescenee  and  formation  of 
alloxan,  alloxantin  and  ureaj   with  hot  HNO:!  parabanie  acid  is  pro- 
duced.   A  yellow  or  red  residue  remains  when  HXO3  is  evaporated  on 
uric  acid,  and  this  assumes  a  fine  red-violet   or  purple  color  when 
moistened,  iu  the  cold,  with  NH4HO,  NaHO  or  KHO  (murexid  reao* 
tion).    On  heating  with  concentrated  ITCl  to  170*^  uric  acid  is  deenni-j 
posed  to  glycoeoU,  ammonia  and  carbon  dioxid:   CsH^NiOa+SHsO^j 
CH2NH2.COOII+3C02+3NHa,  and,  as  ammonia  and  carbon  dioxid] 
are   the  products  of  hydrolysis  of  urea,    this  deeoTupoiriiHon    is  the! 
reverse  of  the  syutltesis  described   above  (p.  529).     When   oxidizedj 
by  lead  peroxid  uric  acid  yields  allautoTn,  carbon  dioxid,   in-ea   anill 
oxalic   acid,    two   distinct   reactions   occurring   at    the   same   time: 


HN.CO.CNH 


\r 


2     I  If  >C0^  2H.OH-02=2 

OC.NH^C.NH^  OC- 


HN.CO.CU.NH.CO.NH3, 


I 
-NH 


+2CO2  and 


HN.CCC.NH. 

I  II  >C04-3n-.0+On=2H.N.rO,NH,-hCOOn,COOH+COi. 

OC.NH.e.NH^ 

Certain  bacteria  decompose  uric  acid  according  to  the  equation: 
CsH+N^Os-f  2H20-f  03=3C02+2H.N.CO.NH2.  Uric  acid  is  decom- 
posed by  sodium  hypobrouiite,  giving  off  47  percent  of  its  nitrogen 
in  the  cold,  or  the  whole  when  heated.  It  reduces  the  salts  of  copper 
on  prolonged  boiling  in  alkaline  solution.  Tliexanthin  bases  (p.  531) 
and  uric  acid  are  pptd.  by  a  mixture  of  equal  volumes  of  a  13  per 
cent  solution  of  CuSO  and  a  50:100  solution  of  NaHSOa  (Kriiger- 
Wolff  reagent),  which  does  not  ppt.  urea.  Uric  acid  is  pptd,  from 
solutions  containing  magnesia  mixture,  by  ainmoniacal  AgXOa,  as 
silver- magnesium  urate.  It  is  pptd.,  as  ammonium  urate,  by  com- 
plete saturation  of  its  solutions  with  NH4CL 


SIX    MEMBERED    HETEROCYCLIC    RINGS 


531 


I 


Uric  acid  behaves  as  a  dibasic  acid.    The  Eiouometallic  salts  are 
formed  by  dissolving  the  acid  in  solutions  of  the  metallic  carbonates, 
or  by  treating  solutions  of  the  dimetallic  salts  with  carbon  dioxid. 
The  dimetallic  salts  are  formed  by  dissolving  the  acid  in  solutions 
of  the  metallic  hydroxids,  free  from  carbonate.     Mono-aninionium 
urate,  C&H3N|03{NH4)»  exists  in  the  solid  urines  of  the  lower  animals, 
and  in  nrinarj"  sediments  and  calenli.     It  is  very  sparingly  soluble 
in  water.     Dipotassic  urate   is  alkaline  in  taste,  absorbs  CO2  from 
the  air,  and  is  soluble  lu  44  parts  of  cold  H2O.     Disodic  urate  fonns 
nodular  masses,  soluble  in  77  parts  of  cold  water,  and  absorbs  CO2 
from  the  air.     It  is  probably  in  this  form  of  combination  that  uric 
acid  exists  normally  in  the  unue,    Monosodic  urate  is  much  less 
soluble,   requiring  1,200  parts  of  water  for  its  solution.     It  exists, 
generally  amorphous,  in  urinary  sediments  (amorphous  urates)  and 
calculi,  and  in  the  arthritic  deposits  of  the  gouty »  sometimes  beauti- 
fully crystalline.     Monocalcic    urate,   soluble  in   603  parts  of  cold 
water,  also  occurs  occasionally  in  urinary  sediments  and  calculi,  and 
in  "chalk   stones,"     Monolithic   urate,  CsH^N^OaLi,  crystallizes    in 
needles,  soluble  in  60  parts  of  wat(*r  at  oO*"  {122°  F.),  or  in   368 
j^RTts  at  19"^  (68,2°  PJ.     It  is  chiefly  with  a  view  to  the  foniiation 
of  this,  the  most  soluble  of  the  monometallic  urates,  that  the  salts 
<:>:£  lithium  are  given  to  patients  snflferiug  from  the  uric  acid  diathesis. 
TT  wo  snlts  of   uric  acid   with   organic  bases  are  still   more  soluble. 
«r-^ iperazin    urate   (p.  522)   dissolves    in    50   parts   of   water   ot    17^ 
C  ^32.6*  F.)  and  lysidin  urate  (p.  514)  in  6  parts  of  water. 

Mcthyluric  Acids* — The  four  H  atoms  of  uric  acid  are  replaceable 
^'^  methyl  groups,  forming  three  mono-,  four  di-,  two  tri*,  and  one 
t^  ^rametbyluric  acids.  These  compounds,  in  which  the  CH3  is 
a  <:  Cached  to  X,  luay  be  considered  as  superior  bomologues  of  uric 
11^:*  id,  or  as  derivatives  of  the  corresponding  metbylpuriiis  (p.  528). 
T'liiey  ai-e  obtained  by  the  action  of  methyl  iodid  upon  urates,  or  from 
atTaer  methylated  pnrin  compounds,  notably  the  methylpseudouric 
ft^^ids,  and  are  used  in  certain  syntheses. 

The  Xanthin,  Alloxuric,  Punn,  or  Nuclein  Bases— form  a  series 
o^  which  nrif  acid  is  the  most  highly  oxidized  member,  and  which, 
\Weiiric  acid,  are  purin  derivatives: 


Uric  acidt 
Xanthin. 

BypoxEothin, 
Guanin, 


CfiHiN+Oa 


HeteroxantliiD^ 

ParaxantiJn, 

Tbeobromin, 

TheophyUiu, 

CaJlein, 

Epigiianm, 


C6H3(CH,)N40i 

C5H3fCHj),N«02 

CsH(CH3)3N|0, 

C4H4(CH3)NaO 


Of  the  substances  named  in  the  first  column,  xanthin,  hypoxanthin 
and  guanin  are,  like  uric  acid,  ketopurins,  also  called   oxypurinSj 


532 


MANUAL    OP    CHEMISTRY 


while  adenia  contains  no  oxygen;  and  gaanin  and  adenin  farther 
differ  from  xanthin  and  hypoxanthin,  in  that  they  contain  an  amido 
group.  Those  in  the  second  column  are  methyl  derivatives  of  xanthin 
or  of  guanin,  to  which  they  bear  the  same  relation  that  the  methylorie 
acids  do  to  uric  acid.  Besides  the  substances  above  enumerated, 
carnin,  C7H8N4O3  and  cpisarkin,  C4H6N3O  (!)  probably  belong  in 
this  class.  Adenin,  guanin,  hypoxanthin  and  xanthin  are  products 
of  decomposition  of  nucleic  acids  (p.  592),  which  are  themselves 
products  of  decomposition  of  nucleoproteids  (p.  591).  The  relations 
of  the  xanthin  bases  to  each  other  and  to  uric  acid  are  shown  in  the 
following  formulae: 


HN-CO 

I     I 
OC    C.NHv 

HN-CNH^ 

Uric  acid. 
2.  6.  8-Triketopurin. 

H3C.N-CO       CH3 

I        I       / 
OC    C.N. 

I      II     iCH 
HN— C.N^ 
Pnraxanthin. 
1,  7-Dimethyl- 
2.  G-diketopurin. 


HN-CO 

I      I 
OC    C.NHv 

I     II        >CH 
HN— C  .  N  ^ 
Xanthin. 
2,  ©-Diketopurin. 

Hx\— CO 

I        I        /CH3 
OC    C.N< 
I      II     >CH 
HaC.N-C.N^ 
Theobromln. 
3.  7-Dim©thyl- 
2.  6-diketoparin. 


H3C.N— CO 

I    I 

OC    C.NHv 

I      II        >CH 
HN— C  .  N  ^ 

l-Metliyl-2.  6- 
diketopurin. 

H3C.N-CO 

I        I 

OC    C.NH. 


H3C.N-C  .  N 
Theophyllin. 
1,  3-DimethyI- 
2,  0-diketopurin, 


^CH 


HN-CO 

I  I  /CH, 
OC    C.N<C 

I  II  >CH 
HN-CN^ 

HeteroTanthii 
T-Methyl-ie^iktlr 

ft 


HjC.N— CO 


y^^ 


OC    c 

I   II 

HsC.N— C.N 

Caffeia. 

1.  3.  7-Trinwlhyl- 

2,  «-<dlketoporin. 


HN-CO 

I  I 
HC    C.NH 

II  II 

N— C  .  N 


CH 


Hypoxanthin. 
6-Ketopurin. 


HN— CO 

I      I 
H2N.C    C.NH 


CH 


II      II         ^' 
N— C.N^ 
Quanin. 
2-Araido-6-ketopurin. 


HN— CO 

I  I      / 
H2N.C    C.NC 

II  II      > 
N— C.N^ 


Epigunnin. 

7-Methyl-^-»mido- 

tf-ketopurin. 


CH3 
CH 


N=C.NH2 

I  I 

HC    C.NH. 

II  II         )CH 
N— C  .  N  ^ 

Adenin. 
G-Amidoporin. 


Xanthin — Xanihic  Acid  —  Urous  Acid — 2,  6-Dikctopurin — 2,  6- 
JXoxypiirin — C5H4N4O2 — occurs  in  a  rare  form  of  vesical  calculus, 
in  the  pancreas,  spleen,  liver,  thymus,  kidneys,  brain,  and  in  the 
melt  of  fishes.  It  is  a  normal  constituent  of  the  urine  in  small 
amount.  Xanthin,  hypoxanthin,  guanin  and  adenin  are  products 
of  decomposition  of  the  uucleius  (p.  592). 

Xanthin  is  obtained  synthetically,  either  by  the  deamidation  of 
guanin  by  nitrous  acid  (p.  535);  or  by  Fischer's  method,  which,  in 
its  variations,  permits  of  the  formation  of  the  several  xanthin  bases 
from  uric  acid  through  the  chloropurins.  In  the  formation  of  xanthin, 
uric  acid  is  converted  into  2,  6,  8-trichloropurin  (1)  by  POCI3.  By 
heating  with  excess  of  sodium  ethylate  this  is  converted  into  2,  6- 
diethoxy-8-chloropurin  (2).  This  is  saponified  by  HCl  to  2,  6- 
diketo-8-chloropurin  (3),  which  is  then  reduced  by  HI  to  xanthin  (4) 


SIX    MEUBERED    HETEROCYCLIC    RINGS 


533 


1    1 

N=C  OCJI5 
1       1 

HN— CO                    HN-CO 

1       1                             II 

Cl.C     LV.NH. 
It     11        >.C] 
N~-C .  N  ^ 

(1) 

C2HSO.C    CNHv 

11    II      >^ci 

N— C  .  N  ^ 

(2) 

OC    C.NHv              OC    C.NH 

1      II         >C,C1        1      II 
HN— C  .  N  ^           HN— C  .  N 
(3)                                (4) 

\ 


I 


CH 


Xauthin  and  hypoxaiitliiu  are  also  formed  in  small  amount  by  the 
direct  reduction  of  iirie  acid  by  nascent  formic  acid.  By  methylation 
xanthin  yields  theobromiu  and  cafifein. 

It  is  usually  amorphous,  but  may  form  crystalline  plates.     It  is 
very  sparingly  soluble  in  water,  1:14,500  at  16  degrees,  1:1,400  at 
100  degrees;  insoluble  in  alcohol  or  ether;  readily  soluble  in  alkalies. 
Its  aramoniactil  solution  gives  a  gelatinous  ppt.  with  AgNO:i,    If  dis- 
solved  in  HNOa,  and   the  solution   evaporated,    it   leaves  a  yellow 
regidoe  which,  with  NaHO,   turns  reddish -yellow,   then  purple- red 
(xanthin  reaction).     It  gives  the  Weidel  reaction  (p.  524),     As  this 
reaction  is  given  with   uracil,   cytosin,   urie  acid,   xanthin,   all    the 
met hylxan thins,   and  alloxan,   but  not   by  hypoxanthiu,  guanin  or 
3denin,  it  would  seem  to  be  characteristic  of  those  pyriinidin  com- 
]30unds  which  contain  the  group  N.CO.N,  and  notably  of  those  con- 
tiAining  two  ketone  gi'oups,  although  cytosin  contains  but  one  such 

t^oup. 
Methybcanthins  —  1-Methylxanthiu,    T-methylxanthin,    or   hete- 
roxanthin,  and  1,  7-dimethylxanthin,  or  paraxanthin  occur  in  small 
Quantities  in  the  urine.    With  the  xanthin  reaction  1-methylxanthin 
firives  an  orange  color;    the  others  are  negative*     Theobroniin,  or 
3,  7-dimethylxanthin,  occurs  in  the  seeds  of  Theabroma  cacao  in  the 
f>roportion  of  about  2  per  cent.     It  is  a  crystalline  powder,  bitter  in 
t^«te;    difficultly  soluble   in   water,  alcohol,  ether  and   chloroform; 
Soluble  in  acids,  with  which  it  forms  salts;   soluble  in  NH4HO,     By 
Partial  demethylation  it  yields  heteroxanthin.     With  AgNOa  it  forms 
^    crystalline  ppt*,  which,  heated  with  methyl   iodid,  yields  caffein. 
*heobromin   and  caffein  have  both  been   obtained  synthetically  by 
Methylation   of   xanthin,   formed  by  oxidation  of  gnanin   (p.  534). 
"^^heophyllin,  or  1,  3-dimethylxanthin,  occurs  in  tea  extract.     It  is 
'^rmed  from  1,  3*dimethylnric  acid,  and  is  manufactured  for  use  as  a 
I       ^i^retic,  from  uric  acid.     Caffein^  or  thein,  or  gnaranin,  or  1,  3,  7- 
k    ^^methylxanthin,  exists  in  coffee,  tea,  Paraguay  tea,  guarana  and 
H    *>ther  plants,  and  may  be  produced  from  1,  3,  7-trimetliylurie  acid. 
B    It  ciystallizes  in  long,  silky  needles;    faintly  bitter;    soluble  in  75 
H     P<»rt8  of  water  at  15  degrees;  less  soluble  in  alcohol  and  ether.    With 
I     UXOi,  evaporation,  and  addition  of  NH4HO  it  gives  a  purple  color. 
I  Hypoxanthin  —  Sarkin  —  6-Kctopurin — ft-  Oxifpurin  —  CsH^NiO — 

■     ^ars  as  a  constituent  of   the   nueleins  in   the  same   situations  as 
^laatbin;  also  in  notable  amount  in  the  blood  of  leukemia,  and  in  the 


534  MANUAL    OP    CHEMISTRY 

melt  of  salmon  and  carp;  also  in  numerous  seeds  and  pollen  of  plants. 
It  is  a  product  of  the  decomposition  of  nucleins  by  acids,  bj  peptie 
and  tryptic  digestion,  and  by  putrefaction. 

Hypoxanthin  is  obtained  synthetically,  either  by  deamidation  of 
adenin  by  nitrous  acid  (adenin,  p.  535) ;  or  by  Fischer's  method  from 
uric  acid  through  2,  6,  8-trichloropurin  (xanthin,  p.  532),  (1).  This 
is  converted  into  2,  8-dichloro-6-ketopurin  (2)  by  KHO;  and  this  is 
reduced  by  HI  and  PBUI  to  hypoxanthin  (3) : 

N=C.C1  HN— CO  HN— CO 

II                                     II  II 

Cl.C    C.NH.  Cl.C    C.NHv  HO    C.NHv 

II     II        >.C1                 II     II        >C.C1  11     II        >CH 

N— C  .  N  ^                        N— C  .  N  ^  N— C  .  N  ^ 

(1)  (2)  (3) 

It  crystallizes  in  small,  colorless  needles;  soluble  in  900  parts  of 
cold  water,  or  in  75  parts  of  boiling  water;  soluble  in  acids  and  in 
alkalies.  Its  ammoniacal  solution  forms  a  ppt.  with  AgNOa.  Fum- 
ing HNO3' oxidizes  it  to  nitroxanthin.  It  does  not  give  the  Weidd 
reaction.  When  acted  upon  by  zinc  and  HCl,  and  then  treated  with 
excess  of  alkali,  it  forms  a  ruby -red  solution,  which  turns  brown-red 
(Kossel's  reaction). 

Guanin — 3-Amido-6-ketopurin — occurs  abundantly  in  guano,  and 
as  the  principal  constituent  of  the  excrement  of  spiders;  in  less  amount, 
as  a  constituent  of  guanylnucleic  acid  (p.  693),  in  the  spleen,  liver, 
pancreas,  in  the  melt  of  the  salmon,  in  the  scales  and  swimming 
bladders  of  certain  fishes,  in  normal  urine  in  traces,  in  the  blood  in 
leukaBmia;  and  in  the  young  leaves  and  pollen  of  certain  plants. 

Guanin  is  produced  synthetically  in  two  ways :  By  Fischer's  method, 
proceeding  as  in  the  synthesis  of  hypoxanthin  (above)  to  the  forma- 
tion of  2,  8-dichloro-6-ketopurin  (1).  This  is  converted  by  heating 
with  alcoholic  ammonia  at  150°  into  2-amido-8-chloro-6-ketopuriD 
(2) ;  which  is  reduced  by  HI  to  guanin: 

HN— CO  HN— CO  HN— CO 


.     C    C.NH.  H2N.C    C.I    _ 

>C.C1  II     II        >C.C1  II     II        ^E 

N— C.N^  N-C.N^  N— C.N^ 


Cl.C    C.NH.  HjN.C    C.NHv  H2N.C    C.NHv 

^r«  r«i  II      II  ^r"  r\  ii      ii  >CH 


(1)  (2)  (3) 

By  Traube's  synthesis,  starting  from  cyanoacetic  ester  (4)  and 
guanidin  (5),  which  condense  to  cyanoacetic  guanid  (6).  This,  by 
union  of  the  amid  and  cyanogen  groups,  forms  an  amidin,  and  the 
six-membered  ring  closes  to  2,  4-aiamido-6-oxypyrimidin  (7).  This, 
by  addition  of  NaN02  to  solution  of  the  base,  forms  a  rose-colored 
isonitroso  compound,  neither  basic  nor  acid,  which  on  reduction  by 


SIX    MEMBEBED    HETEBOOTCLIC    BING8  535 

HiS  forms  2,  4,  5-triamido-6-oxypyriii]idiii  (8),  which  is  a  strong 
diacid  base,  and  which,  on  boiling  with  strong  formic  acid,  forms 
gnanin  (9): 

HN  COOCCaHc)  HN— CO  N=C.OH 

II  I  II  II 

HjN.C  CHa  H2N.C    CHa  HaN.C    CH 


L„ 


HaN  CN  HaN    CN  N-C.NHa 

(5)  (4)  (6)  (7) 


N=C.OH  HN— CO  HN— CO 

II  II  II 

HaN.C    C.NHa  HaN.C    C.NH^  OC    C.NHv 

II     II  II     II        >CH  I      II        >CH 

N— C.NHa  N— C  .  N  ^  HN— C  .  N  ^ 

(8)  (9)  (10) 

Qnanin  is  deamidated  by  nitrous  acid  with  formation  of  xanthin 
(10): 

HN.CO.C.NH.  HN.CO.C.NH. 

I  II        >CH4-HN0a=  I  11         ^CH-hNa+HaO; 

HaN.C  :N— C  .  N  ^  OC.NH.C  .  N  ^ 

and  xanthin,  in  turn,  may  be  methylated  to  theobromin  and  caffein. 
Ouanin  is  oxidized  by  E2Mn208+HGl,  with  formation  of  guanidin 
and  oxalylurea : 

HN.CO.C.NH.  HaN  CO.NHv 

I  11        >CH4-30-hHaO=  |  +1  >CO-fCOa. 

HaN.C  :N-C .  N  ^  HaN.C  :NH  CO.NH^ 

Quanin  is  a  white  or  yellowish,  amorphous  and  odorless  powder: 
almost  insoluble  in  water,  alcohol  and  ether;  readily  soluble  in  acids 
and  alkalies.  It  forms  crystalline  ppts.  with  silver  nitrate  and  with 
picric  acid.  It  gives  the  xanthin  reaction  with  HNOs  and  NaHO; 
bat  it  does  not  respond  to  the  Weidel  reaction. 

Adenin— 6-Amidopurin — C5H5N6 — exists,  in  nucleic  acids,  widely 
disseminated  in  nucleated  cells,  most  abundantly  in  carp-melt  and  in 
the  thymus  gland.  It  occurs  in  the  blood  and  urine  in  leukaemia,  and 
also  exists  in  yeast  and  abundantly  in  tea  leaves. 

It  is  formed  synthetically  by  Fischer's  method:  By  the  action  of 
POCla  upon  potassium  urate  2,  6-dichloro-8-ketopurin  (1)  is  pro- 
duced. This  is  converted  into  2-chloro-6-amido-8-ketopurin  (2) 
by  NHa.  This  is  converted  by  POCla  into  2,  8-dichloro-6-amidopurin 
(3) ;   which  is  reduced  by  HI  to  adenin  (4) : 

N=C.C1  N=C.NHa  N=C.NHa  N=C.NHa 

CI.C    C.NHv  Cl.C    C.NH.  Cl.C    C.NHv  HC    C.NH 


„        >C0  II     II         >C0  II     I!        >CI         II     II        > 

•c.nh/  n-c.nh/  n-c.n^  n-c.n<^ 

(I)  (2)  (3)  (4) 


536 


MANUAL    CP    CHEMISTRY 


As  guaDiu  is  deaojidated  to  xanthiii,  so  adeuiti,  on  deamidation^ 
yields  liypoxauthiu : 


N:C(NH2).C.NH. 
I 


CH:N 


C,N 


CHfHNO. 


HNXO.C.NH^ 

I  II 

CH:N.C,N 


XH+Na+HaO. 


I 


Adeiiiti  crystallizes  in  nacreous  plates,  or  in  long  yeedles,  with:! 
3Aq,  which  they  lose  at  KXJ"^,  althongh  they  suddenly  become  opaque 
at  53^,  a  property  characteristic  of  adenin.  Very  soluble  in  hot 
water,  it  requires  1,086  parts  of  cold  water  for  its  solution; 
insoluble  in  cold  alcohol,  ether  and  chloroform;  readily  soluble 
ill  acids  and  alkalies,  with  which  it  forms  compounds.  Its  solu- 
bility in  ammonia  is  less  than  that  of  hypoxanthin,  but  greater 
thau  that  of  guanin.  It  forms  crystalline,  difficultly  soluble  com- 
pounds with  silver  Tiitrate  and  with  picric  acid.  It  is  not  reddened^— 
by  wanniug  with  HNOa  and  moistening  the  residue  with  alkali;  doellH 
not  respond  to  the  Weidel  reaction,  but  behaves  like  hypoxanthiu 
towards  Kossel's  reaction. 

Carnin^UrUHNiOa — ^is  obtained  from  Liebig^s  meat  extract,  and 
has  also  been  found  in  the  muscular  tissue  of  fishes  and  frogs,  and 
in  the  urine.  It  is  isomeric  with  the  dimethyluric  acids.  It  foruis 
chalky,  microscopic  crystals,  readily  soluble  in  hot  water,  sparingly 
soluble  in  cold  water,  insoluble  in  alcohol  and  ether.  It  forms  com* 
pounds  with  acids  and  with  alkalies,  similar  to  those  of  hypoxanthiu* 
Chlorin,  bromiu  and  nitrous  acid  convert  it  into  hypoxaothin,  with 
elimination  of  the  elenieuts  of  acetic  acid.  It  does  not  respond  to  the^ 
Weidel  reaction.  H 

Epiguafiin — CeHrNrAi. — ^Besides  7-methylxauthin,  which  isbetero* 
xanthiu,  and  7-niethyluric  acid,  similar  derivatives  of  hypoxanthiu, 
guanin  and  adenin  have  also  been  obtained  synthetically.     7*Methyl* 
guanin  is  epiguaniu,  which  occurs  in  minute  quantity  in  the  nnne.^H 
Episarkin  is  possibly  identical  with  epiguanin.  ^| 

Triazins — are  compounds  containing  three  nitrogen  atoms  in  a 
fiix-membered  ring: 


H 
C 

^  \ 

C        N 

I  II 
C  N 
/ 


N 

1.2.  3-Trt«zin, 
Orthotriwiin. 


N^CH 

I  1 
N    CH 

II  11 


N=CH 

I  I 
N    CH 

II  II 
HC— N 


1,  2,  4-Triittlii. 


N^CH 

I    I 

HC  N 
II  II 
N— CH 


1.3.  .'i-TriKilM, 
PjirwtrinK^n, 
Cyuiiidhj. 


The  parent  ortho-  and  meta- com  pounds  are  not  known,  but  muuv 
of  their  derivatives  have  been  obtained,  none  of  which  is,  however,  of 

medical  interest. 


CONDENSED    HETEROCYCLIC    COMPOUNDS 


537 


Para-,  or  y-triazin,  also  called  cyanidin,  is  the  still  imidcutified 
trihj'drocyaii iti  aeid,  which  is  the  parent  substance  of  certain  metal- 
loeyanitls  {p,  398) ,  and  of  the  cyanuric  compounds  (p.  396) ,  Although 
hytlrocyanic  aeid,  pore  or  in  concentrated  suhition,  polymerizes 
n^adily  in  contact  of  alkalie.s^  of  KCN,  etc.,  the  product  has  not  the 
constitution  of  cyauidiu^  but  that  of  aniidomalonic  nitril:  CN.CH- 
(XH.;),CN.  TIr'  trichloro  derivative  is,  however,  known,  as 
tricyanogen  ehlorid  {p.  393} »  and  the  corresponding  bromid  and 
iodid  are  aL^o  known.  The  idkyl  cyanidins  are  the  polymeres  of  the 
fatty  acid  nitrils  above  acetonitriL  Phenyl  and  phenyl -alkylcyanidins 
are  also  known,  of  which  triphenylcyanidin,  or  cyanophenin,  C3N3 
(CfiHrt):!,  was  the  first  obtained  of  the  compounds  of  this  class;  formed 
by  the  action  of  benzoyl  ehlorid  upon  potassium  cyanate:  3CN0K+ 
3C6H5.COCl=CaN:,(CflH5)3+3KCl+3C02.  It  is  also  formed  by  the 
action  of  sodium  upon  a  mixture  of  monoiodo- benzene  and  trieyanogen 
ehlorid:    C3X,Cl:(+3C«H5l+3Xa2=C3N-,(CaH5)3+3NaI+3NaCi. 

Trioxycyanidin  nniy  exist  either  in  the  enol  form  (1)  or  in  the 
ketone  form  (2),  The  former  is  the  probable  constitutinn  of  cyanuric 
acid  (p,  396).  Corresponding  to  cyanuric  acid  are  a  number  of  alkyl, 
acidyl  and  amido  derivatives.  Among  the 
last  named  are  ammcUd  (3),  ammelin  (4) 
and  melamin  (5),  which  are  mono-,  di-  Hnd 
triamidocyanidiu  respectively;  ca<*h  of  which 
forms  a  number  of  derivatives  by  substitution 
of  alkyls  for  H  in  NH2.  Ammelid  is  one  of 
the  products  of  the  action  of  heat  upon  nrea  (p.  404).  Melarain  is 
obtaintjd  by  the  action  of  KHO  on  mclam^  CsHtNut  which  is  pro- 
dnced  by  heating  ammonium  thiocyauate  to  300^,  Melamin  is  hydro- 
lysed  by  long  heating  with  acids  or  alkalies,  first  to  ammcHn,  then  to 
ammelid,  and  finally  to  cyanuric  acid. 


N==C.OH 

I  I 
HO.C    N 

II  II 
N— C.OH 

(1) 


HN— CO 

I       t 
OC     NH 

I       I 

HN— CO 

(2) 


N=C.OH 

I  1 
HOX    N 

II  If 
N— C.KHa 

(3) 


N=:C.OH 

I  I 
HsN.C    N 

II  II 
N-C.NHa 

(4) 


N=C.NHa 
I 


BjN.C    N 


N— C.NHa 
(5) 


CONDENSED  HETEROCYCLIC  COMPOUNDS. 


Theae  compounds,  which  are  more  tiumerous  thrin  the  correspond* 
lag  carbocyclie  compiJUiid.s  (p.  493),  Uiuy  im  considered  as  being 
derived  from  the  hitter  by  substitution  of  N  for  methine,  =CH — , 
or  of  O,  S,  or  NH  in  a  bivalcuL  position,  or,  as  in  the  ease  of 
iso-indole  (p.  538),  by  substitution  and  modification  of  internal  link- 


538 


MANUAL    OP    CHEMISTRY 


age.  The  number  of  these  substances  is  still  further  increased  by 
the  existence  of  four  ringed -compounds,  such  as  the  anthraquinolins 
and  indigo-blue  (p.  542).  The  formulae  below  are  those  of  some 
of  the  nitrogen  derivatives,  in  which  indole  and  isoindole  may 
be  considered  as  derived  from  indene  (p.  493):  carbazole  from 
fluorene;  quinolin,  iso-quinolin  and  naphthydrin  from  naphthalene: 
acridin  and  the  anthrapyridins  from  anthracene;  and  phenanthridin 
from  phenanthrene: 


H 
C 

HCa       c- 


I    Bz.   II  Py 
HC2 


-CH/S 


C  CHa 

\i/   \   / 

C  Nn 

H  H 

Benso-pyrrole. 

(Indole). 


H 
C 
^   \ 
HC  C CH2 

I  II  I 

HC  C         N 

\   /   \   ^ 
C  C 

H  H 

Iso-indole. 


H  H 

C  C 

^  \  /   \ 

HC  C C  CH 

T      II      II      I 

HC  C         C  CH 

%  /  \  /   \  ^ 

C  N  C 

H  H  H 

Diiihenylene-imid. 
(Carbazole). 


H  H 

C  C7 

^4\     /\ 
HC3         C  CH/J 

^1    Bz.   II    Py.    I 
fiC2         C  CHa 

%!/    \    ^ 
C  N 

H 

Benzo-pyridin. 
(Quinolin). 


H  H 

C  C 

^  \    /   \ 
HC  C  CH 

I  II  I 

HC  C  N 

%    /    \    ^ 
C  C 

H  H 

IBO-Qolnolin. 


H  H 

C  C 

^   \    /   \ 

HC  C  CH 


C 

\    /    \    ^ 

N  N 

Naphthydrin. 


I 
CH 


HC 

I 

HC 


H  H  H 

C  C  C 

^    \    /    \    /   \ 


C 

II 

c 


c 

H 


N 


CH 

II  I 

C  CH 

C 
H 


Acridin. 


H  H  H 

C  C  C 

/   \   X    \   /    % 

HC  C  C  CH 

I  II  II  I 

HC  C  C  N 

\    /    \    /    \    ^ 

C  C  C 

H  H  H 

a-Anthrapyridin. 


HC 


H  H  H 

C  C  C 

^   \    /    \_/  \, 


CH 


HC  C  C  CH 

\   /    \    /   \    /' 
C  C  N 

H  H 

^Anthrapyridin. 


H    H  H    H 

C=C  C^C 

/  \  /  \ 

HC  C  C  CH 

\  /  \  / 

C-C  C-C 

H      \  /       H 

N=C 

H 

Phenanthridin. 


CONDENSED    HETEROCYCLIC    COMPOUNDS  539 


CONDENSED   NUCLEI   CONTAINING    OXYQEN    OR   SULFUR 

MEMBERS. 

Of  these  we  will  consider  only  a  few  of  the  oxygen  compounds: 
Coumarone  —  Benzofurfurane — (formula  below)— is  formed  by 
the  action  of  EHO  upon  the  coumarins,  and  is  the  parent  substance 
of  two  series  of  substitution  derivatives,  o,  and  P. 

Coumarin,  and  isocoumarin  and  their  alkyl  and  phenolic  deriva- 
tives, e.g.  umbelliferone,  aesculetin,  daphnetin,  hesperetin,  exist  in 
different  vegetables  (pp.  466,  467) .  Coumarin  is  the  odorous  principle 
of  Tonka  beans,  and  also  exists  in  a  variety  of  other  vegetables.  It  is 
formed  by  the  action  of  acetic  anhydrid  and  sodium  acetate  upon 
salicylic  aldehyde.  It  forms  crystalline  needles;  f.p.  67°;  soluble  in 
water,  alcohol  and  ether.  Coumarin  and  isocoumarin  are  benzo- 
derivatives  of  a-pyrone  (p.  516) : 

H  H  H  H         H 

C  C  C  C  C 

^  \  ^   \   /  \  ^   \   /   \ 

HC  C CH  HC  C  CH  HC  C  CH 

I             II           II  I             II             I  I             II            I 

HC           C          CH  HC          C          CO  HC           C          O 

\   /   \   /  %   /  \  /  %   /   \   / 

CO  CO  c         c 

H  H  HO 

Coam:irone.  Conmarin.  Iso-coiimariu. 

Benzo-  and  dibenzo-7-pyrones,  the  latter  called  xanthones,  exist 
in  several  natural  yellow  dyes  of  vegetable  origin,  as  those  from 
quercetin  and  chrysin. 


CONDENSED    NUCLEI    CONTAINING    A    NITROGEN    MEMBER. 
BENZOPYRROLE    AND    ITS    DERIVATIVES  —  INDIGO    COMPOUNDS. 

Indole— Benzopyrrole — (formula  p.  538) — is  produced:  (1)  by 
distilling  oxindole  over  zinc-dust;  (2)  by  heating  o-nitro-cinnamic 
acid  (p.  458)  with  potash  and  iron  filings,  or  by  similar  reduction 
of  other  unsaturated  o-nitro  substitution  products  of  benzene  (3) 
by  the  interaction  of  calcium  formate  and  phenylglycocoU  (p. 
478) .  It  is  one  of  the  products  of  puti^efaction  of  the  proteins  by 
ansBrobic  bacteria,  and  is  formed  in  the  intestine  during  pancreatic 
digestion  of  those  substances.  It  is  partly  eliminated  with  the  faeces 
and  partly  reabsorbed,  appearing  in  the  urine  in  sulfoconjugate  com- 
bination. It  crystallizes  in  large,  shining,  colorless  plates,  having 
the  disagreeable  odor  of  naphthylamin.  It  is  a  weak  base,  and  its 
salts  are  decomposed  by  boiling  water.  Its  aqueous  solution,  acidu- 
lated with  HCl,  is  colored  rose-red  by  KNO2.    By  fusion  with  KHO 


540 


MANUAL    OF    CHEMISTRY 


it  yields  aoilio.  It  gives  the  ^' pine -shaving  reaction"  (p.  510)*  It 
forms  a  eompoimd,  erystalUzing  in  red  needles,  with  picric  acid. 

Indole  Homotogues  —  Derivatives  of  indole  are  produced  by 
snbstitution  either  in  the  benzene  or  in  the  pyrrole  ring.  The  posi- 
tions are  disttngnished  as  Bz.  1,  2,  3,  4  and  Py.n,  «.  and  ^  (see 
formula  p.  538).  The  alicyl  indoles,  the  superior  homologues  of 
indole,  are  formed;  (1)  by  heating  anilin  with  compounds  containing 
the  group  CO.CH2CL     Thus  chloracetone  and  anilin  yield  a. methyl- 

indole :  CH2CtCOX^H3+C6H5,NH2  =  C6H4<^^rH^^^ 

(2)  by  heating  the  phenyl hydrazones  (p.  486)  of  the  ketones^  alde- 
hydes or  ketone  acids  with  ZnCls.  Thus  ?«,  a-dimethylindolc  is 
obtained  from  acetone  -  phenyl-  methyl  -  hydrazoue  :    Ceils. N  (CH3); 

N:C0::fi^=C«U<;;;^^f)>C.CH,+NH3. 

The  best  known  alkyl  indoles  are  those  in  which  the  alkyl  group 
is  in  the  pyrrole  ring.  They  dissolve  in  concentrated  acids,  and  are 
precipitated  unaltered  from  the  solutions  by  dilution  with  water. 
Fused  with  KHO,  they  yield  potassium  salts  of  indole- carboxylic 
acids.  Their  hydrogen  may  be  replaced  by  aeidyls  or  by  the  diazo 
group.  They  give  the  '*  pine -shaving  reaction,"  and  form  red, 
crystalline  compounds  with  picric  acid. 

Indole-^-acetic  acid. — The  product  of  putrefaction,  which  also 
exists  in  normal  urine,  described  as  skatole  carboxylic  acid,  is  not 
that  substance,  but  its  isomere,  indole-j3-rteetic  acid  (formula  below). 
It  produces  an  intense  violet  color  with  HOI  and  dilute  Fei^Cle  solution. 

Tryptophane  —  Proteinochronwgen  —  Indole -/?-0-amidopropionic 
Acid— 


H 

0 

/\ 

HC      C C.CH2 

XOOH 

1        II         II 

HC      C        CH 

\  /\/ 

C        N 

H       H 

lDdc»le-^iic«t]c  neld. 

H 
C 


HC 

I 
HC 


CH3.NH2 


i 
COOH 


C        CH 
/  \/ 

C         N 
H        H 

Tryptophan©* 

is  a  product  of  decomposition  of  proteins  by  energetic  decomposing 
agents  such  as  BaH202,H2SOi,  tryptic  digestion  and  putrefaction,  but 
not  by  peptic  digestion.  With  Br  or  CI  it  forms  a  red -violet  pigment, 
called  protdoochromc.  It  crystallizes  in  shining  plates,  easily  soluble 
in  hot  water,  difficultly  in  cold  water  or  alcohol.  When  heated  it 
yields  indole  and  skatole.  It  gives  the  Adamkiewicz  reaction.  Its 
solution  on  a  pine  shaving,  previously  moistened  with  HCl,  and  sub- 
sequently washed  and  dried,  gives  a  purple  color  (pyrrole  reaetinn). 
By  aneerobic  putrefaction  it  yields  indole~^-propionic  acid;  and  by 


3NDENSEB   HETEROCYCLIC   COMPOUNDS 


S41 


®robic  putrefactiou  indolt'-^-aeetie  acid,  and  indole.    It  is  tlie  parent 
substance  of  tlie  kynurie  acid  found  in  tlie  nrtiie  of  dogs  (p*  544). 
i3.McthyMndolc  —  Skatole—CftH4<(j[T^l'^'^^CH— exists  in  fasces, 

in  which  it  exceeds  the  indole  in  amount.  It  is  formed  during  putre- 
faction of  the  proteins,  or  by  the  action  U[ton  theoi  of  KHO^  in 
fusion;  also  by  the  reduction  of  indigo.  It  is  best  obtained  syntheti- 
cally   by    heating    propidene^phenylbj^drazone    with    zinc    ehlorid : 

CsHs.NH.N: CH.CH2,CH3  =  CHi^N^H^^/CH+NHa.     It  crystallizes 

in  brilliant  plates;  f.p.  95*^  {203°  Fj;  insoluble  in  water,  soluble  in 
alcohol  and  in  ether;  distils  with  vapor  of  wat(=^r;  has  a  strong  faecal 
odor.  Its  solution  in  concentrated  HCl  is  violet.  Its  HtjSOi  solution 
is  colored  deep  purple  when  heated.  Skatole,  like  indole,  is  in  part 
reabsorbed  from  the  intestine,  and  appears  in  the  urine,  combined 
with  sulfuric  and  glucuronic  acids. 

Iso- indole— (formula,  p.  538)— is  formed  by  the  action  of  alco- 
holic ammonia  upon  brom-acetophenone  (p,  455).  It  crystallizes  in 
colorless,  siJky  plates;  f.  p.  195°;  insoluble  in  water,  soluble  in 
alcohol »  ether  and  benzene. 

Indoxyl  — iS-Oxyindole  — C6H4<(Sfl3i^CH  — not  to  be  con- 
founded with  oxindole  (below)  ,  is  a  phenolic  derivative  of  indole, 
obtained  from  indigo-blue  by  fusion  with  KHO  without  contact  of 
air;  or  from  its  a-carboxylic  acid,  indoxylic  acid.  It  is  a  very 
unstable,  oily  substance,  soluble  in  water,  and  readily  oxidized  to 
indigo-blue  (p.  542).      It  readily  combines  with  sulfuric  acid  or  the 


which  is 


e—O— S:Oa 

sulfates  to  form  indoxyl-sulfuric  acid,  C6H4C  \ 

^NH— CH  OH 

the  uroxanthtn,  or  urinary  indican,  existing  in  the  urine,  and  formed 
from  indole.  Acids  decompose  it,  with  formation  of  indoxyl,  which 
is  converted  into  indigo -blue  by  Pe^Clo  (see  Urine), 

Oxindole  —  CeHi^xfj^^CO  —  the  lactam  of  o-amido -phenyl  acetic 

acid  (p.  478),  is  obtained  from  dioxindole  by  reduction  with  sodium 
amalgam  in  acid  solution;  or  by  reduction  of  o-nitrophenyl -acetic 
acid.  It  crystallizes  in  easily  sohible^  colorless  needles;  f,  p.  120^. 
In  moist  air  it  oxidizes  to  dioxindole.  It  reduces  ammoniacal  silver 
nitrate  solution.     It  combines  with  acids  and  bases. 

Dioxindole— Hydriodic  Acid— C6H4<(^h^^^CO— is  the  lactam 

o-amido-mandclic  acid  (p.  478),  and  is  formed  by  the  action  of  Na 
on  isatiu  suspended  in  water.  It  forms  yellow  prisms,  soluble  in 
water,  and  combines  with  acids  and  bases. 

Isatin  —  CoH^C^f^rij  ;C0^— the  lactam  of  o*amido -benzoyl *formic 
acid  (p.  478),  is  formed  by  (vxidation  of  indigo-bhie  by  HNO3;  by 
oxidation  of  oxindole  or  of  dioxindole;  and  by  other  methods.    I*;  crys- 


542 


MANUAL    OF    CHEMISTRY 


tallizes  in  shiniEg,  transparent,  red -brown  prisms,  odorless,  sparingly 
soluble  in  water,  readily  soluble  in  aleohoL     On  further  oxidation  it 

CO 


yields  isatoic  acid«  CeH4 


\ 


N.COOH 


With  hydroxylamin  it  forms  isa- 


^C— NOH 
toxim,  CfiHiC  '\        j  which  is  also  formed  by  the  action  of  nitrons 

^N=COH 

acid  upon  oxiuclole* 

Indigo  -  blue  — Indigotin — GuHi^  j^^y  C :  C'C^^C^^—  constitutes 

the  grreater  part  of  commercial  indigo.  It  does  not  exist  preformed 
in  nature,  but  many  plants ^  particularly  Indigotifera  Unctoria  and 
Jantis  tincioria,  contain  a  yellow  glucosid,  iudiean  (p,  467),  which 
on  beating  with  dilute  acids,  or  probably  by  enzymic  action  on  ex- 
posure to  air  in  preseuce  of  wat*.-r»  is  decomposed  into  a  sugar  and 
indig:o-blue.  Commercial  indigo  contaius  20  to  90  per  cent,  of 
indigo -blue,  which  may  be  separated,  ueariy  pure,  by  cautious  sub- 
limation. It  is  formed  in  several  reactions,  e.g.,  by  oxidation  of 
indoxyi  by  FcjClfl  and  HCl;  from  o-nitro-cinnamie  acid  by  two 
methods?  by  fusiug  phenyl *glyeoc oil  (p*  478)  with  KHO-  or  by 
heating  o-nitro*ac-etopheuone  (p.  455)  with  zinc  dust.  It  forms 
pnrple-red,  metallic,  shining  prisms  or  pktes,  odorless,  tasteless, 
neutral,  soluble  in  hot  auilin.  hot  oil  of  turpentine,  and  melted 
paraffin,  insoluble  in  the  usual  solvents.  When  heated  it  is  in 
part  converted  into  a  dark- red  vapor,  and  partly  decomposed  into 
anilin  and  otlier  products.  In  the  preseuee  of  aqueous  alkaline 
solutions,  reducing  agents  convert   indigo -blue   into   indigo- white, 

or  di-indoxyl,  CfiH4<^NH5^C— C^t!:!^^  which  dissolves  in  the 

alkali.  This  substance  absorbs  oxygen  from  the  air  rapidly,  with 
regeneration  of  indigo -blue.  In  absence  of  air  it  may  be  precipitated 
froui  its  alkaline  solution  by  HCl,  as  a  white,  crystalline  powder, 
insoluble  in  water,  but  soluble  in  alcohol  and  ether,  forming  yellow 
solutions.  When  oxidized,  as  by  warming  with  dilute  HNO3,  indigo- 
blue  is  converted  into  isatin,  whose  dilute  solutions  ai^  also  yellow. 
Hence  the  decoloration  of  indigo -blue  solution  is  utilized  as  a  test 
both  for  oxidising  (HNO3)  and  for  reducing  ( Mulder -Neubauer  test 
for  glucose)  substances. 

Indigo- sulfonic  Acids.  —  Indigo -blue  dissolves  slowly  in  concen- 
trated sulfuric  acid,  to  a  green  solution,  from  which  water  precipitates 
a  blue  powder,  soluble  in  water ^  but  insoluble  in  dilute  acids.  This 
is  indigo-monosulfonic  or  phoenicin- sulfonic  acid,  CiftH&NiOs.SOaH, 
which  forms  purple -red  salts,  soluble  in  water.  With  fuming  (Nord- 
hausen)  sulfuric  acid,  indigo-diaulfoniC)  sulfiodylic^  or  sulfindigotic 
acid,  CiflH8N202(S03H)a>  is  formed »  whose  K  and  Na  salts  are  also 
s*>luble  in  water,  and  are  met  with  in  commerce  as  pastes  called 
indigo-carmlne. 


C0NBEN8ED  HETEROCYCLIC  COMPOUNDS 


543 


Dtbenzo- pyrrole — Diphenyl  imid — Carbazole^-C formula  p.  538) — 
exists  in  crtide  anthraeene,  and  is  formed  by  passing  dipheujiamin 
through  a  red- hot  tube,  and  from  other  dipheuyl  derivatives.  It 
is  a  erystalliue  solid;  f.  p.  238°;  soluble  hi  akohol  and  in  toloene. 
It  is  a  weak  base,  gives  the  pine -shaving  reaetion,  and  the  blue  color 
with  isatiu  and  H2SO1,  and  forms  a  pierate  fusible  at  182^. 


QUmOLIN    AJn>    ISO-QUINOLIN    AND    THEIR    DERIVATIVES. 

The  quinolin,  or  benzo-pyxidin  bases  accorapany  the  pyridin 
bases  (p.  517)  in  bone -oil,  and  like  those  substances,  are  closely 
related  to  the  vegetable  alkaloids.  Qninolin,  the  parent  substance  of 
the  group,  was  first  obtained  by  distilling  quinin  and  cinehonin  with 
lime. 

Chemically  the  quinolins  are  also  related  to  the  naphthalenes 
(p.  494) t  and  are  formed  by  similar  synthetic  methods.  Thus 
quinoliQ    is    formed     from   allyl-anilin  :    C(iH5.NH.CH2.CH:Cn^  =^ 

manner  as  naphthalene  is  formed 

Quinolin  and  its  derivatives  may 


CeHi 


/N    :CH 
\CH:CR 


+2H2,  in  the  same 


CfH4<^^^;;;  +  CH3.CO.CHa:=CeH4^^ 


from  phenyl -butylene  (p.  495) 
also  be  produced  synthetically  r  (1)  From  o-amido-benzenie  cam* 
pounds  containing  an  oxygen  atom  in  the  second  lateral  chain. 
Thus  o-amido- benzoic  aldehyde  and  acetone  yield  a-methyl-quinolin: 

,CH:CH 

I  +2H2O.   (2)  Bvheat- 

N    :C(CHa) 

ing  the  anilins  with  glycerol  and  HsSO*,  in  presence  of  an  oxidizing 

agent,  such  as  nitro- benzene  ;    C6H5,NH2+CH20H,CHOH.CH20H^ 

XHiCH 
CeH4\        I    +3H2O+H2.     (3)    By  the   action  of    aldehydes   upon 

anilins  in  presence  of  H38O4  or  HCK     Thus  a -methyl -quinolin  is  ob- 
tained  from  anilin  and  acetic   aldehyde  :    CeH6.NH2+2CHO.CH3= 
XHrCH 

The  quinolin  bases  are  liquids  of  penetrating  odor,  sparingly  sol* 
Uble  in  water,  readily  soluble  in  alcohol  and  in  ether.  They  are 
strong  triacid  bases,  and  form  salts  and  ammonium-like  compounds. 
XH:CH 

Quinolin— C6H4<^        I   —is  a  mobile  liquid ;  b.  p.  238°  (460.4*' 

PJ;  becoming  rapidly  brown  on  exposure  to  air;  has  an  intensely 
icrid  and  bitter  taste,  and  an  odor  somewhat  like  that  of  bitter 
almonds:   sparingly  sohible  in  water,  readily  sohible  in  alcohol  and 


elts  dichroniate  crystallizes  in  yellow  needles 
\y  soluble  in  water, 



f.  p.  165^;  very 


Ui 


MANUAL    OF    CHEMISTRY 


Quinolin  Homologues. — Qmoolin  is  the  Eucleus  of  a  vast  number 

of  products  of  substitution,  among  which  are  many  isomeres,  due  to 
difYereuees  in  orientation,  according  as  the  substitution  oceui's  in  the 
0-,  m-,  or  p-  position  in  the  benzene  ring,  or  in  the  ^s  ^t  or  -y  posi- 
tiou  in  the  pyridin  not*  (gee  formula,  p.  538),  Thus  there  are  seven 
methyl-qyinolins*  or  lepidins,  etc. 

Quinoliu  is  of  medical  interest  chiefly  in  connection  with  the  vege- 
table alkaloids  of  which  it  is  the  nucleus  (p.  556).  Certain  synthetic 
basic  anlvstuuees  coutaining  the  fjuinolin  nucleus  have  also  been  used 
in  medicine^  in  saline  combination,  as  antiperiodies  and  antipyreti* 
Among  these  are  thallin,  ethyl-thallin  and  kairin. 

>CH:CH 


y^ 


<i*OxyquinoHn — Carbostyril — C^H^^^ 


I       —is 

iC.OH 


the    lactam 


o-araido-einnamif^  acid,  formed  by  reduction  of  o-nitro-cinnamie  ester. 
Kynuric  Acid — Kynurenic  Acid' — CK1H7NO3— has  been  found  in  the 
urine  of  dogs  only.  It  is  increased  in  amount  of  dog*s  urine,  and  ap- 
pears in  rabbit^s  urine  after  administration  of  tryptophane  (p.  540). 
It  has  been  obtained  synthetically  by  a  method  which  shows  it  to  be 


1 


/ 


C{OH):C.COOH 


N= 


I 
-CH 


When  heated 


7-oxy-j9-quinolin  carboxylic  acid :   C6H4\ 

it  splits  off  CO3,  and  forms  kynurin,  ory-oxyqutnolin.  It  forms  crystals, 
insoluble  in  water,  soluble  in  hot  alcohol.     It^  Ba  salt  crystallizes  in 
triangular  plates.     Heated  with  HCH-KClOa  to  dryness,  it  leaves  a 
reddish  residue  which  turns  green  with  ammonia  (Jaffe^s  reaction).    ^| 
/GH:CH  ^ 

Iso-qyinolin — CeH^  I    — differs  from  quinoliu    in   that  the 

^  \CH:N 

attaehmeut  of  the  benzene  and  the  pyridin  rings  is  by  the  ^  and  y 
position.^  of  the  latter  in  iso-quinolin,  and  by  the  «  and  fi  positions 
in  quinoliu  (see  formnlfp^  p.  538).    It  accompanies  quinolin  in  coal- 
tar,  and  is  the  nucleus  of  some  of  the  opium  alkaloids  {p,  565).    Il|fl 
resembles  quinolin  in  its  properties,    F.  p.  23°;   b.  p.  240.5*^.  ^" 

Hydroquinolins. — Compounds  corresponding  to  dihydroquinolins 
are  known.    Tetrahydroquinolins   are  formed,  by  hydration  of  the 
pyridin  ring,  Ity  the  actiiui  of  nascent  hydrogen  on  qninolins,    Decd*_^ 
hydroquinolin^    CVIihN,    corresponding    to    pi  per  id  in     (p*    519),  >8^| 
formed  by  beating  quinolin  with  hydriodie  aeid  and  pliosphorus. 

Higher  Condensed  Heterocyclic  Compounds — Acridin — Ci3H»N 
(p.  538)^-a  three -ringed  hetei*ocyclic  compound,  exists  in  coat  tar. 
It  and  its  homologucs  are  produced  by  heating  acidyl  derivatives  of 
diphenylamin  with  ZnCI^.  Other  three-  and  frmr*ringed  compounds 
are  produced  by  condetrsation  of  aldehydes  with  naphthylamin  and 
anthramiu,  as  quinolin  is  produced  from  anilin.  Naphthalinolin  is  a 
four- ringed  nur*leus  of  two  benzene  rings  fused  upon  one  of  naph- 
thydrin  (p.  538), 


PHENYL- pyRlDYL,  DIPYRIDYL    COMPOUNDS,  ETC. 


545 


I 


PHENYL- PYRIDYL,   DIPYRIDYL.  AND   PYRIDYL- 
PYRROLE   COxMFOUNDS. 

These  compounds  (p.  508)  contain  two  nuclei,  one  at  least  hetero- 
cyclic, united  together  by  loss  of  two  liydrogen  atoms. 

Phenyl-pyridyls,  or  phenyl*pyridlns  (p.  519)  consist  of  one  or 
more    phenyl     groups    substituted     in    pyridin,    7- Phenyl *pyridylj 

N%CH^CH./^ — ^%CH-CI1  :J*^^»  ^^  ^^^^  ^^  ^^^  ^  ^^^  ^  compounds, 
and  diphenyl-  and  tetraphenyl-pyridins,  are  known. 

7,  >-DipyridyI— Ns^cH-CH/<^— C^CH^H/-^  formed  by  the 
action  of  sodium  upon  pjTidin.  It  forms  colorless  needles;  f.  p. 
114°;  which  yield  isonicotinic  acid  (p,  519)  on  oxidation.  The  a-^ 
and  P'fi  dipyridyls  are  formed  by  oxidation  of  the  phenanthrolins, 
and  both  yield  nieotinte  acid  on  oxidation.  A  fourth,  probably  a -a, 
is  formed  by  passing  vapor  of  pyridiu  through  a  red-hot  tube.  The 
^ipjTidyls  take  up  nascent  hydrogen  to  form  subtitances,  CioHnNs, 
isomeric  with  nieotin,  and  resembling  that  alkaloid  (p.  551)  closely 
in  chemical  properties  and  in  physioh>gical  action.  The  one  obtained 
from  P'P  dipyridyl  is  a  very  soluble  and  highly  poisonous  liquid, 
c?alled  nicotidin.  That  from  7-7  dipyridyl  is  a  crystalline  solid,  sol- 
uble in  water,  less  actively  poisonous  than  nicotin,  and  called  iso- 
«^icotin, 

The  pyridylvpyrroles  are  formed  by  union  of  a  pyridin  and  a 
I^jrrole  ring,  as  the  dipyridins  are  formed  by  union  of  two  pyridin 


riii^,       a* Pyridin -^- pyrrole,    HC 


tutes   the    nucleus  of   nicotin  (p.  551)* 

^-  p.  72^ 


iC— Of  I    ,    consti- 

It  is   a   crystalline   solid; 


ALKALOIDS. 

Vntil  the  constitution  of  all  the  substances  grouped  under  this 
shall  have  been  determined,  the  limitations  of  the  application  of 
^^  name  can  be  only  provisional.  It  was  first  applied  to  the  few 
alkali- like  substances  first  obtained  from  vegetable  products,  the 
^^getable  bases  morphin,  narcotiu,  veratrin,  strychnin.  Afterwards 
*^  application  was  extended,  and  at  the  same  time  made  more  precise, 
^  include  organic,  nitrogenized  substances,  alkaline  in  reaction,  and 
^pable  of  combining  with  acids  to  form  salts  in  the  same  way  as  does 
^monia.  This  limitation  is,  however,  too  broad,  as  it  classes  the 
aliphatic  amins,  and  other  similar  bodies,  with  the  true  alkaloids, 
^hicbare  cyclic.    All  substances  generally  classed  as  alkaloids,  whose 

35 


546  MANUAL    OP    CHEMI8TBY 

coDstitation  has  been  determined,  contain  at  least  one  nitrogen- 
containing  heterocyclic  ring,  except  theobromin  and  caffem,  which 
are  not  true  alkaloids,  bat  pnrin  bases  (p.  533).  Almost  all  alka- 
loids of  known  constitution  contain  the  pyridin  ring,  more  or  less 
modified  by  hydrogenation,  either  alone  or  in  qninolin  or  isoqninolio. 
Therefore,  until  recently,  alkaloids  were  considered  to  be:  basic  sob- 
stances  containing  the  pyridin  ring.  But  the  hygrins,  alkaloids 
existing  in  coca  leaves,  are  derivatives,  not  of  pyridin,  but  of  pjr- 
rolidiu  (p.  511),  a  five-membered  nucleus.  So  far  as  is  now  known, 
no  alkaloid  contains  more  than  one  nitrogen  atom  in  one  and  the  same 
ring.  Therefore,  provisionally,  it  may  be  stated  that  the  alkaloids 
are  basic  substances  derived  from  heterocyclic  nuclei  containing  bnt 
one  nitrogen  atom  in  any  nucleus.  Under  this  definition  pyridin 
and  qninolin  and  their  homolognes  are  alkaloids,  as  well  as  indole, 
and  other  basic  pyrrole  compounds. 

Some  of  the  alkaloids,  nicotin,  coniin,  spartem  and  arecolin  are 
liquid,  volatile,  and  contain  C,  N  and  H.  Most  of  them,  to  the  num- 
ber of  more  than  a  hundred,  are  solid,  crystalline,  only  partiallj 
volatile  without  decomposition,  if  at  all,  and  contain  C,  N,  H  and  0. 
Most  of  the  alkaloids  are  very  sparingly  soluble  in  water,  althongb 
some  are  readily  soluble;  but  soluble  in  alcohol,  ether,  petroleum- 
ether,  chloroform,  benzene  or  amylic  alcohol.  Their  salts,  on  the 
other  hand,  are,  for  the  most  part,  soluble  in  water,  but  insoluble  in 
the  other  solvents  mentioned,  except  alcohol,  in  which  they  are 
soluble.  They  are  laevogyrous,  except  quinidin,  cinchonin,  coniin, 
narcotin  and  pilocarpin,  which  are  dextrogyrous.  Usually  their 
rotary  power  is  diminished  by  combination  with  acids,  although  with 
quinin  the  reverse  is  the  case.  Free  narcotin  is  laevogyrous,  its 
salts  are  dextrogyrous.  Most  of  the  alkaloids  are  bitter  in  taste,  and 
alkaline  in  reaction. 

The  naming  of  the  salts  of  the  alkaloids  has  been  the  subject  of 
no  little  discussion.  In  obedience  to  the  rules  of  orthography 
adopted  (see  Appendix)  the  names  of  the  alkaloids  are  made  to 
terminate  in  tn,  although  in  non-chemical  writings  the  termination 
ine  is  still  usual,  and  the  older  termination  ia  is  occasionally  met 
with.  As  most  of  the  alkaloids  are  tertiary  amins  and  some  second- 
ary amins,  they  combine  with  acids  in  the  same  manner  that  ammonia 
does,  that  is,  without  elimination  of  water  or  of  hydrogen,  and  by 
change  of  the  nitrogen  valence  from  trivalent  to  quinquivalent: 

2H3 ':  N+H2804=(H3  I  N:h^^^ 
Ammonia.       Snlforic  acid.       Ammonium  sulfate. 


2[(C,7Hi«03)  :  N]+H2S04=[(C,7Hi903)  iNOa^gg^ 
Morphia.       Snlfaric  acid.       Morphium  loUate. 


ALKALOIDS 


647 


Therefore  these  salts  do  not  contain  morphin,  CnHiaOaN'''''.  as  a  euL- 
stitute  for  the  hydrogen  of  the  acid,  but  the  hypothetieal  morphium 
(Ci7H2oOaN'')',  as  the  aramoniacal  salts  are  Dot  salts  of  ammonia,  NH;j» 
but  of  aniraoninna,  NH*.  The  compounds  formed  by  the  onion  of  mor- 
phin  and  other  alkaloids  with  the  hydracids,  HCl,  HBr,  HI,  may 
properly  and  conveniently  be  referred  to  as  inorphio  hydrochlorid  (not 
hydrochlorate )  hydrobromid,  hydroiodid,  etc,  they  bein^  considered, 
not  as  salts  of  those  acids,  but  as  compounds  in  which  one  of  the 
valences  of  the  quinquivalent  uitmgen  atom  is  satisfied  by  hydrogen 
and  another  by  ehlorin, 

JIany  of  the  alkaloids  behave  like  esters,  and  are  hydrolyzed  by 

baryta  or  the  caustic  alkalies,  or  by  minerfll  acids,  into  two  com* 

ponents,  one  a  base,  the  other  an  acid,  the  latter  usually  cyclic  and 

nitrogenous.      On  the  other  hand,  concentrated   HCl   removes  Hl^O 

from  those  alkaloids  containing  more  than  one  hydroxyl^  converting 

them  into  apo-alkaloids,  as  morphin  is  converted  into  apomorphin. 

Other  alkaloids,   containing  methoxyl  groups   (OCHa),   when  acted 

upon  by  concentrated  HCl,   are  modified  by  replacement  of  OH  for 

the  methoxyl  groups.     Reducing  agents  with  alkaloids  whose  nuclei 

contain  double  bonds,  form  hydro -bases,  as  piperidin  is  derived  from 

pyridin.     Distillation  with  zinc-dust  causes  removal   of   the  lateral 

<^hains  from  the  oxygen -containing  alkaloids,  with  liberation  of  pyridin 

or  quinolin.     Oxidizing  agents  form  carboxylic  acids,  or  decompose 

the  alkaloid  into  an  ecid  and  a  base,  or  cause  the  union  of  two  mole- 

c^ules  of  the  alkaloid  witli  loss  of  hydrogen. 

t     Separation  of  Alkaloids  from  Organic  Mixturcs*^^The  separation 
t  an  alkaloid  from  an  organic  mixture  (contents  of  stomach,  viscera » 
te.)  in  a  condition  of  purity  sufficient  to  permit  of  its  identification, 
*«5   one  of  the  most  difficult  tasks  of  the  toxicologist,  and  not  to  be 
attempted  in  a  case  liable  to  be  the  subject  of  legal  inquiry  except  by 
*>ne  thoroughly  competent.     The  pi'ocesses  usually  followed  are  modi- 
L  fieations  of  that  originany  used  by  8tas,  of  which  the  most  exhaus- 
pttve  is  the  method  of  Dragendorff.     They  depend  upon  diflPerences  in 
^TO  solubilities  of  the  several  alkaloids  and  of  their  salts  in  water  or 
^cohol,  and  in  various  solvents  immiscible  with  water.     The  alkaloid 
**  first  extracted  as  a  tartrate,  sulfate  or  hydrochlorid  by  water  or 
alcohol,  acidulated  with  the  appropriate  acid,  and  the  extract  purified 
^>  a  clear,  acid,  watery  solution.     This  acid  solution  is  then  succes- 
**v«Iy  shaken  with  the  immiscible  solvents,  such  aa  ether,  petroleum - 
^her,   benzene,    chloroform,    amylic  alcohol   and  acetic   ether,   the 
•olventfi  being  separated  from  the  aqueous  solution,  and  each  evap- 
^med  by  itself.     During  this  treatment  the  alkaloids  are  held  in  the 
■<l^eoa8   solution »   while  the  other  solvents  extract  impurities   and 
^Hskin  glucosidal  and  acid  poisons.      The  watery  solution  is  now 


» 


548 


MANUAL    OF    CHEMISTRY 


rendered  alkaline,  wliich  causes  liberation  of  the  alkaloid  from  itt  ,, 
saline  eombination,  and  is  again  snccesjsively  agitated  with  the  ut^M 
miscible  solvents  named,  tliey  bein^  each  individnally  separated  froi^^ 
the  aqneous  liqnid  and  evaporated.  Each  solvent  extracts  tho*e 
alkaloids  which  it  is  capable  of  dissolving,  and  they  are  sooght  f< 
by  the  suitable  tests  in  the  appropriate  residues.  Thus  strychnin 
extracted  by  benzene,  and  niorphin  by  amylic  alcohol.  The  detail 
of  the  process,  which  are  quite  elaborate,  must  be  carefully  observei 
and  the  student  is  referred  to  special  treatises  upon  the  subject. 

General    Reactions    of    the   Alkaloids.  —  A    great    number 
** general  reagents '"  for  alkaloids  have  been  suggested,  of  which  onl; 
the  more  important  can  be  here  mentioned: 

Fotaah,  soda,  ammonia,  Ume,  baryta  and  magnfsia  precipitate  th 
alkaloids  from  solutions  of  their  salts. 

Fhosphomoitfbdic  and  forms  a  precipitate  which  is  bright-yellor 
with  anilin,  niorphin,  veratrin,  aconitin»  enietin,  atropin,  hyoseyamin, 
thein,   theobromin,   coniin   and  nicotin;    brownish -yellow  with  nar*; 
cotin,  codein,  and  piperin;    yellowish -white  with  quinin,   einehoiiii 
and  strychnin;  yolk-yellow  with  brucin  (DeVry*s,  or  Sonnenschein*i 
reagent). 

Potassium   iodhydrnrgyrate    gives    a    yellowish    precipitate  witli 
f^lkaloida!  solutions  which  are   acid,   neutral  or  faintly  alkaline  ii 
reaction  (Mayer's  reagent). 

Classification  of  the  Alkaloids. — The  alkaloids  of  known,  or  par 
tially  known  constitution,  can  be  classified  according  to  the  nocKi 
which  they  contain: 

A.  Pyrrolidin  Alkaloids, — The  hygrins, 

B.  Pijridin  Alkaloids. — Trigonelliu,  pilocarpin  (T). 

C.  PiperideiH  (tetrahydropyridin)  Aikaloidii. — Arecolin,  arecaidii 
y-conicein  (f),  pseudopelietierin,  pelletierin  (?). 

D.  Piperidin  Alkaloids. —  Coniin,  conhydrin,  arecam,  juvaciD] 
piperiu, 

E.  P^rrolidin-pyridin  Alkaloids. — Nicotin. 
P.   Pyrrolidin -piperidin  Alkaloids. — Tropan  Alkaloids. — AtropiDi 

hyoscyamin,  hyoscin  (T),  eegonin,  cocain,  cinnarayl-cocain,  a-traxil 
lin,  ^-truxiliin,    benzoyl -eegonin,  tropacocatn. 

G.  Quinolin  Alkaloids. —  Cinchona  alkaloids,  strychnos  alka 
loids(T). 

H.  Isoquinolhi  Alkaloids. —  Papaverin,  narcotio,  narcein  (!) 
hydrastin,  berberin  {?). 

L  Phenanthrene  Alkaloids .—yLorphin,  codein,  thebain. 

X,  Alkaloids  of  unknown  constitution. 

Ptjrrolidin  Alkaloids,— Hy grin,  CgHisNO,  and  Cuzcohygrin,  Cir 
HaiN20,  are  poisonous  alkaloids,  occurring  in  the  leaves  of  Etythraif 


ALKALOIDS 


549 


hn  coca.  The  former  is  1 -methyl -2- acetouylpyrrolidiii  (1,  below), 
and  the  latter  is  derived  from  it  by  the  substitution  of  another 
pyrrolidin  ring  for  H  in  CH3,  aud  is  therefore  jiynu  di-1-metbylpyrrol- 
idyl  acetone, 

PyrkUn    Alkaloids. — TrigonelHn,  CtHtNO^   (2,    below),   a  non- 
pK)isonous,  cryslalUue  alkaloid,  which  oceurs  iu  fenugreek,  peas  and 
liemp«    is   identical    with    the   synthetic    methyl    betain  {p,   384)   of 
liicotinic^  or  pyndin-^-monocarboxylic  acid  (3) : 


CH 

H 

/  \ 

C 

H2C CHi 

HC        C— CO                /   \ 

1           1 

1          tl 

HC        CXOOH 

HaC        CH.CHaXO.CHa 

HC        CH 

1          II 

\/ 

\  / 

HC        CH 

N 

^ — -0 

%  / 

CH3 

CHj 

N 

(1) 

(2) 

(3) 

The  jaborandi  alkaloids,  pilocarpin,  C11HMN2O2,  pilocarpidin^ 
CioHi4Ni202,  and  jabortn,  C22H32N4O4,  probably  belong  in  this  group, 

ripendein  Alkaloids, —  Arecaidin,  C7H11XO2,  one  of  the  four 
alkaloids  of  the  betel -nut,  ia  the  ^-nionocurboxylie  acid  of  t^ -methyl- 
tetrahydropyridin ;  and  arecolin,  C^HnNOa,  another  alkaloid  from 
the  same  plant,  is  its  methyl  ester. 

Of  the  four  alkaloids  from  pomegranate — pelletierin,  CsHi^NO,  iso- 
pelletierin,  CgHisNO,  methylpelletierin,  CallnNO,  and  pseudopel- 
Ictierin,  CuHisNO,— the  only  one  whose  constitution  is  known  is  the 
last  named^  which  is  n -methyl -2 -acetonyltetrahydropyridin. 

IPiperidm  Allaloid.^. — ^The  alkaloids  known  to  contain  a  single 
piperidin  ring  as  a  nucleus  are  the  five  alkaloids  of  Conium  nmvtdatum , 
coniin,  CuHnN,  conhydrin,  CgHivNOi  comcein,  CwHl^N,  tt-methyl- 
coni'in,  CglTi^N,  and  pseudoconhydrin,  CgHnNO^    and  two  of  the  four 

^  betel -nut  alkaloids;  arccam,  C7H11NO2,  and  guvacin,  CoHsNOa* 
Coniin — CgHnN — is  one  of   the  most  simply  constituted  of  the 
natural  vegetable  alkaloids,  and  was  the  first  to  be  produced  syuthet- 
ically.     It  is  a  colorless,  oily  liquid;   has  an  acrid  taste  aud  a  dis- 
lagreeable,  peoetrating  odor;   sp.gr.  0.844;   can  be  distilled  when  pro- 
tected from  air;   b.p.  166*^,    Exposed  to  air  it  resinifies.    The  natural 
alkaloid    is  d-coniin»   Md^Io.T'^.     It  is  very  sparingly  soluble   in 
■water,  but  is  more  soluble  in  cold  than  in  hot  water;   soluble  in  all 
■proportions   in    alcohol,   easily  soluble   in   ether,   and    in    fixed  and 
volatile  oils. 

I       Its  vapor  at  ordinary  temperatures  forms  a  white  cloud  when  in 

^eontact  with  a  glass  rod  moistened  with  HCl,  as  does  NHg,     It  forms 

salts  which  crystallize  with  difficulty.    Chlorin  and  bromin  combine 

ith  it  to  form  crystallizable  compounds;   iodiu  in  alcoholic  solution 


550  MANUAL    OP    CHEMI8TBY 

forms  a  brown  precipitate  in  alcoholic  solntions  of  coniin,  which  is 
soluble  without  color  in  an  excess.  Ethyl  and  methyl  iodids  combiDe 
with  it  to  form  crystallizable  compounds;  iodin  in  alcoholic  soIntioD 
forms  a  brown  precipitate  in  alcoholic  solutions  of  coniin,  which  u 
soluble  without  color  in  an  excess.  Ethyl  and  methyl  iodids  combine 
with  it  to  form  ethyl-  and  methyl -coniin  hydriodids. 

It  has  been  obtained  synthetically  from  a-picolin  by  reactions 
which  show  it  to  be  a -propyl  piperidin.  The  relations  of  pyridin, 
piperidin,  and  coniin  are  shown  by  the  following  formulae : 

H  H,  H, 

C  C  C 

/\  /\  /\ 

HC        CH  H2C        CH2  HjC        CH, 

II         I  II  II 

HC        CH  H2C        CH2  HjC        CHCjHt 

\^                                    \/  \/ 

N                                         N  N 

H  H 

Pyridin.                                    Piperidin.  Coniin. 

Analytical  Characters. — (1.)  With  dry  HCl  gas  it  turns  red- 
dish-purple,  and  then  dark-blue.  (2)  Aqueous  HCl  of  sp.  gr.  1.12 
evaporated  from  coniin  leaves  a  green-blue,  crystalline  mass.  (3) 
With  iodic  acid:  a  white  ppt.  from  alcoholic  solutions.  (4)  With 
H2SO4  and  evaporation  of  the  acid:  a  red  color,  changing  to  green, 
and  an  odor  of  butyric  acid.  (5)  When  mixed  with  commereial 
nitrobenzene  a  fine  blue  color  is  produced,  changing  to  red  and 
yellow. 

Paraconim — CgHisN— is  a  synthetical  product  closely  resembling: 
coniin,  obtained  by  first  allowing  butyric  aldehyde  and  an  alcoholic 
solution  of  ammonia  to  remain  some  months  in  contact  at  30 
(86°  F.),  when  dibutyraldin  is  formed:  2(C4H8O)+NH3=C8Hi7N0+ 
H2O.  The  dibutyraldin  thus  obtained  is  then  heated  underpressure 
to  150M80''  (302''-356''  F.),  when  it  loses  water,  and  forms  para- 
conim: C8Hi7NO^C8Hi5N+H20.  A  synthesis  which,  in  connection 
with  the  decompositions  of  paraconiin,  shows  its  rational  formula  to 

be  ^^*^^^''Jn. 

Pipcrin — C17H19NO3 — isomeric  with  morphin,  and  occurring  in 
black  and  white  pepper,  crystallizes  in  large  prisms;  f.  p.  12S  ; 
almost  insoluble  in  water,  readily  soluble  in  alcohol  and  in  ether.  It 
is  a  weak  base,  without  alkaline  reaction,  and  only  forming  very 
unstable  salts  with  concentrated  acids.  It  is  one  of  the  alkaloids 
whose  complete  synthesis  has  been  accomplished,  and  is  quite  directly 
derived  from  piperidin,  of  which  it  is  an  n-acidyl  derivative.  When 
piperin  is  heated  with  alcoholic  soda,  it  is  hydrolysed  into  piperic 
acid,  C12H10O4  (p.  458),  and  piperidin.  It  is  therefore  piperidin 
piperate,  or  piperidin-3,  4-methylene-dioxy-cinnamyl-acrylate : 


ALKALOIDS 


551 


Pyrldln. 


C 

H,C  CH, 

I  I 

HaC  CHj 

\   / 


Plp«H«Ilii. 


H3C 


CH> 


/ 


\ 


'\ 


c— O^ 


CHj 


CH 


io. 


CH:CH.  CH: 

Plperin. 


P^rroHdin-pyridin  Alkalmds  are  representad  by 

Nicotin — C10H14N2 — whioh  exists  in  tobacco  in  the  proportioQ  of 
2-8  per  cent.  It  is  a  co!orlesa,  oily  liquid,  which  turns  brown  on 
exposure  to  air,  has  a  burning,  caustic  taste,  and  a  disair^eeable, 
penetrating  odor.  It  distils  at  250°  (392°  F.);  burns  with  a  lumi- 
nous flame;  sp,  gr.  1,027  at  15"^  (59°  PJ;  is  very  soluble  in  water, 
alcohol,  the  fatty  oils,  and  ether.  The  last-named  fluid  removes  it 
from  its  aqueous  solution  when  the  two  are  shaken  together.  It 
absorbs  water  rapidly  from  moist  air.  Its  salts  are  deliquescent,  and 
crystallize  with  difficulty.  The  natural  alkaloid  is  1 -nicotin.  The 
i-nicotin  has  been  obtained  by  total  synthesis,  through  /?*amidopyridin. 
Prom  this  1 -nicotin  is  produced  by  the  action  of  tartaric  acid. 

The  oxidation  of  nicotin  produces  nicotinic,  or^monocarbopyridic, 
acid  (p.  519).  When  distilled  with  zinc  chlorid  and  lime  it  yields 
pyrrole,  ammonia,  methylamin,  hydrogen,  and  pyridin  bases.  When 
heated  to  250°  (482°  F.)  it  yields  a  collidin  along  with  other  products. 
By  limited  oxidation  it  produces  a  substance,  C10H10N2,  foimerly 
considered  as  isodipyridlo,  but  shown  to  be  /3-pyTidiQ-ii-methyl»a- 
pyrrole, 


HC 


/' 


CH=CH. 


^CH     — CH 


^N 


— CH^         \NfCH3)CH 


of  which  nicotin  is  the  tetrahydro,  or  pyrrolidin  derivative— 


HC: 


/CH^CH*^  ^CHf      — OH3 

>C-CH<  I     . 

^  ^N(CH9)-CHa 


^N   — CH^ 


Analytical  Characters. — (1)  Its  ethereal  solution,  added  to 
an  ethereal  solution  of  iodin,  separates  a  reddish -brown,  resinoid  oil, 
which  gradually  becomes  crystalline.  (2)  With  HCl,  a  violet  color. 
(3)   With  HNO3,  an  orange  color. 

Toxicology. — Nicotin  is  a  very  active  poison.  The  free  alkaloid 
is  probably  capable  of  causing  death  in  doses  of  two  to  three  drops. 
It  was  the  first  alkaloid  to  be  separated  from  the  cadaver  in  a  case  of 
homicide.  Most  cases  of  poisoning  frora  nicotin  are  due  to  tobacco, 
frequently  resulting  from  its  use  in  eneraata.     When  administered  to 


552 


MANUAL    OP    CHEMISTBr 


dogs  in  doses  of  two  to  four  drops,  its  effects  begin  within  half  « 
minute  to  two  minutes,  and  death  ensues  within  one  to  five  minutes. 
In  man  tobacco  or  its  decoction  causes  nausea,  vertigo,  dilatation  of 
the  pupils,  vomiting,  syncope,  diminution  of  the  rapidity  and  force  of 
the  heart.  With  large  doses  there  are  no  subjective  symptoms,  tbe 
victim  falls  unconscious  instantly,  and  dies  within  five  minutes,  with- 
out convulsions,  and  with  very  few  or  only  one  deep  sighing  respira- 
tory act.  The  I-nicotin  has  double  the  toxic  power  of  d-nicotin,  and 
the  two  forms  differ  in  the  nature  of  the  action  produced. 

Pyrrolidin-piperidin  Alkaloids — Trapan  Alkaloids. — The  alkaloids 
of  this  group,  most  of  which  are  est^r- alkaloids,  including  the  atropic 
alkaloids,  atropin,  hyoscyamin,  and  hyoscin,  and  the  coca  alkaloids, 
ecgonin,  cocain,  cinnamyl-cocain,  a-  and  i^-truxillins,  benzoylecgonin 
and  tropacocain,  are  derivatives  of  tropan  (1),  then -methyl  derivative 
of  nortropan  (2),  both  of  which  are  known,  as  well  as  many  of  their 
compounds  other  than  alkaloids: 


HjC 


HjC 


c 
/  \ 

HC        CH2 

I  I       ^ 

H3C.N  CH2 
\/ 

c 


H2C— CH CH2 

I  I 

N.CH3  CH2 

H2C— CH CH2 


(1) 


H, 

C 

/  \ 

XI2C — IxC  CH2 

I  I 

HN        CH, 

\  / 
H2C -C 


HfC— CH— CHs 

I      I         I 
NH     CHs 

HfC— CH— CHi 


(2) 


Nortropan  may  be  considered  as  formed  by  condensation  of  a 
pyrrolidin  ring  and  a  piperidin  ring,  having  the  group  =CH.NH.CH= 
in  common.  The  following  tropan  derivatives  are  of  interest  in 
connection  with  the  syntheses  of  atropic  and  coca  alkaloids. 

Tropidin — (formula  below) — is  adehydrotropan,  first  obtained  as 
a  product  of  decomposition  of  atropin,  and  later  of  cocain,  thus  indi- 
cating the  relationship  of  the  two  alkaloids.  It  has  been  obtained  by 
total  synthesis,  starting  from  synthetic  glycerol  (p.  296),  through 
allyl  broraid  (p.  426),  trimethylene  bromid,  trimethylene  cyauid, 
glutaric  acid  (p.  337),  to  suberone  (formula  below).  Prom  suberone 
to  tropidin  many  steps  are  required,  the  principal  intermediate  pro- 
ducts being  cycloheptene  (2),  cycloheptatriene,  and  a -methyl  tropidin: 


H2C.CH2.CO 

I 

CH2 
I 
H2CCH2  •  CH2 

Sul>erone. 


H2C.CH2.CH 

II 
CH 

I 
H2C.CH2.CH2 

Cycloheptene. 


H2C.CH CH 

I  II 

N.CH3   CH 

I  I 

HoC.CH CH2 

Tropidin. 


Tropin — (formula  p.  553) — 4-Tropan  Alcohol — is  formed,  through 
its  space  isomere,  ^-tropin,  by  conversion  of  tropidin  into  a  dibromo 


ALKALOIDS 


553 


adtlitiuo  product,  and  splitting  off  of  Br2  and  addition  of  H2O  hy 
Wating  with  H28O4  at  200°,  Tropin  is  the  alcohoJic  component  of 
atropin,  hyoscyamin  and  the  tropins,  and  of  which  ecgonin  (p.  556) 
^the  earboxylic  acid. 

Atropin — i-Tropin  tropate — CnHz^NOa.  —  Belladonna,  strarao- 
ninm,  hyo8cyamiis  and  dnboisia  contain  five  alkaloids:  atropio, 
hyoscyamin,  hyogcin,  scopolamin  and  belladonaiuj  of  which  the  first 
two  are  optical  isomeres  of  each  other. 

Atropin  forms  colorless,  silky  needles,  sparingly  soluble  in  cold 
water,  more  readily  in  hot  water,  very  soluble  in  chloroform.  It  is 
odorless,  has  a  disagreeable,  persistentj  bitter  taste.  Both  tropin  and 
tropic  acid  (see  below)  contain  an  asymmetric  earboo  atom.  The 
tropin  in  atropin  is  i-tropin»  and  the  acid  is  d- tropic  acid.  Both 
natural  and  synthetic  atropins  are  optically  inactive.  Atropin  is  dis- 
tinctly alkaline,  and  iientralizes  acids  with  formation  of  salts.  The 
sulfate  is  a  white,  crystalline  powder,  readily  soluble  in  water. 

Atropin  is  the  type  of  the  "ester  alkaloids'^  saponiliable  into  an 
acid  and  an  alcoholic  component.  When  it  is  acted  npon  by  BaHaOa  at 
60"*,  or  by  NaHO  or  HCI  at  120M30''.  it  is  saponified,  after  the 
manner  of  an  ester,  into  tropic,  or  a-pbenylhydracrylie  acid  (p.  463)  > 
CeHs.CHYQi^  Qjj»  and  a  secondary  cyclic    alcohol,   tropin   (formula 

below).  But  if  the  action  be  prolonged  the  tropic  acid  is  further 
decomposed  into  a-phenylacrylic,  or  atropic,  and  isatropie  acids 
(p.  457).  And  if,  diinug  the  action  of  HCI,  the  temperature  rises  to 
180*^,  the  tropin  loses  water,  and  is  converted  into  tropidin. 

The  total  synthesis  of  atropin  has  been  accomplished;  the  tropin 
component  having  been  obtained  in  the  manner  indicated  on  p.  552, 
and  tropic  acid  by  the  synthesis  described  on  p.  463.  Tropin  and 
tropic  acid  readily  combine  to  form  atropin:  CgHi5NO+CtiHio03= 
OnHiaNOa+HaO.  The  relation  of  atropin  to  its  progenitors  is  shown 
in  the  following  formnlro: 


HaC.CH CH3 

I  I 

I        I 

HaC  *  CH CHg 


HsCXH CH 

I  II 

N.CHa   CH 

HaCCH CHa 

Tropidin. 


HaCCH CH, 

I  I 

N.CHa    CHOH 
I  I 

H2C.CH CHi 

Tropin. 


HOOC.CH- 


H 
C 

^\ 
-C        CH 


I  I 

CH.OH  HC 


Trople  Aeid. 


CH 


/ 


u 


HaC.CH 

I 
N.CHj 

I 
HaC.CH— 


-CHs 

I 
CH.OOC.CH 


-CH, 


H 
C 

^\ 
-C  CH 

I  I  !! 

CH..OH  HC  CH 

%/ 
C 

H 


Tropin  tropAt^r-Alropla. 


554  MANUAL    OP    CHEMISTRY 

Analytical  Characters. — (1)  K  a  fragment  of  potassium  di- 
chromate  be  dissolved  in  a  few  drops  of  H2SO4,  the  mixture  warmed, 
a  fragment  of  atropin  and  a  drop  or  two  of  H2O  added,  and  the 
mixture  stirred,  an  odor  of  orange-blossoms  is  developed.  (2)  A 
solution  of  atropin  dropped  upon  the  eye  of  a  cat  produces  dilatafion 
of  the  pupil.  (3)  The  dry  alkaloid  (or  salt)  is  moistened  with  fuming 
HNO3  and  the  mixture  dried  on  the  water-bath.  When  cold,  it  is 
moistened  with  an  alcoholic  solution  of  KHO:  a  violet  color,  which 
changes  to  red  (Vitali).  (4)  If  a  saturated  solution  of  Br  in  HBr 
be  added  to  a  solution  of  atropin,  a  yellow  precipitate  is  fonned, 
which  rapidly  becomes  crystalline,  and  which  is  insoluble  in  acetic 
acid,  sparingly  soluble  in  H2SO4  and  HCl. 

Toxicology. — The  clinical  history  of  atropic  poisoning  is  divisible 
into  two  stages,  the  first  one  of  delirium,  in  which  the  prominent 
symptoms  are  dryness  of  the  throat,  thirst,  difficulty  of  deglutition 
and  spasms  upon  swallowing  liquids,  face  at  first  pale,  afterwards 
highly  reddened,  pulse  extremely  rapid,  eyes  prominent,  brilliant, 
with   widely -dilated   pupils,  complete   paralysis   of  accommodation, 
disturbances  of  vision,  attacks  of  giddiness  and  vertigo,  with  severe 
headache,  followed  by  delirium,  occasionally  silent  or  muttering,  but 
usually  violent,  noisy  and  destructive,  accompanied  by  the  most  fan- 
tastic delusions  and  hallucinatious.     Usually  the  urine  is  retained, 
and  the  body  temperature  is  above  the  normal.     The  delirium  grad- 
ually subsides,  and  the  second  stage,  that  of  coma,  is  established,  with 
slow,  stertorous  respiration,  and  gradually  failing  pulse,  until  death 
occurs   from  respiratory  or  cardiac   paralysis,  or  sometimes   in  an 
attack  of  syncope  during  apparent  amelioration.     In  some  cases,  the 
patient  rapidly  becomes  comatose  at  the  outset,  and  the  symptoms  of 
the  first  stage  are  manifested  as  the  coma  diminishes.     The  treatment 
should  consist  of  lavage  of  the  stomach,  and  morphin  may  be  given 
cautiously  during  the  period  of  violent  excitement.     In  the  second 
stage,  the  treatment  is  the  same  as  in  morphin  poisoning.    Pilocarpin 
may  be  given,  in  not  too  large  doses,  to  stimulate  the  secretion  of 
saliva.     Atropic    poisoning    leaves   no    characteristic    post-mortem 
lesions. 

Hyoscyamin  —  C17H23NO3 — isomeric  with  atropin,  predominates 
in  Uyoscyamus  nigevy  and  in  mandragora.  It  differs  from  atropin 
principally  in  being  laevogyrous,  [a]D= — 20.3°,  and  on  saponifica- 
tion it  yields  1- tropic  acid  and  i- tropin.  It  is  converted  into 
atropin  very  easily,  by  heat,  or  by  addition  of  alkali  to  its  alcoholic 
solution. 

Apoatropin — Atropamin — Tropin  atropate — CnHaiNOa — is  formed 
by  the  action  of  dehydrating  agents,  H2S04,P205,  etc.,  on  atropin  or 
hyoscyamin,  by  splitting  off  of  H2O  from  the  acid  component,  thus  con- 


ALKALOIDS 


65S 


verting  the  residue  of  the  saturated  tropic  acid  into  that  of  the 
UQsaturated  atropic  aeid.  By  Iieat  it  is  converted  into  its  isomere, 
bcUadonnin^  an  alkaloid  vviiicli  accompanies  atropiu  in  belladoiiua. 
Hyoscin  and  scopolamin,  CnH-iNO*,  are  two  isomeric,  mydriatic 
alkaloids,  «ccompaiiying  atropin  in  belladonna.  The  latter  on  decom- 
position yields  tropic  acid  and  scopolinp  CsHisNOq,  which  is  closely 
related  to  tropin,  C«Hi5N0, 

Tropeins^are  eater -like  derivatives  of  tropin  with  acids,  similar 
to  atropin.  Many  such  have  been  formed  with  organic  acids,  benzoic, 
salicylic,  etc.  That  formed  with  mandelic  acid  (p.  463)  is  known  as 
homatropinp  CgHi4N,00C.CH(0H).CflHi>,  and  is  used  as  a  mydriatic 
having  a  less  prolonged  action  than  atropin.  Only  those  tropems 
whose  acid  radicals  contain  an  alcoholic  hydro xyl  Lave  a  mydriatic 
action. 

Ecgonin — C&H15NO3 — an  alkaloid  existing  in  Eryfhroxijlon  coca^ 
and  the  parent  substance  of  cocaTu  and  other  coca  alkaloids,  is  4-oxy- 
tropan-5-monoearboxylic  acid  (p.  556).  By  the  action  of  dehydrat- 
ing agents  upon  ecgonin  the  al<M>bolic  OH  and  an  H  atom  are  split  off, 
and  anhydroecgonin,  CalluXOa,  is  formed,  which,  by  splitting  off  of 
CO2  from  the  carboxyl,  forms  tropidin.  Ecgonin,  being  both  basic 
and  acid,  forms  esters  and  salts,  and  numerous  products  of  derivation 
other  than  cocaln.  When  acted  upon  by  a  mixture  of  methyl  iodid 
and  benzoic  anhydrid,  ecgonin  is  converted  into  cocaln.  Or  by  sub- 
stitution of  other  alkyl  iodids  for  that  of  methyl,  other  alkaloids, 
homologous  with  cocain,  are  obtained  (see  formuhe  below). 

Cocain — CnHnNO* — the  most  important  of  the  coca  alkaloids,  is 
closely  related  chemically  to  atropin.  It  crystallizes  in  large  four-  or 
six-sided  prisms;  f.  p.  98*^;  sparingly  soluble  in  water,  readily  isoluble 
ID  alcohol,  ether  and  chloroform;  somewhat  bitter  at  first,  bnt 
causing  paralysis  of  the  sense  of  taste  afterwards;  strongly  alkaline. 
Its  hydrochlorid,  used  as  a  local  anaesthetic,  crystallizes  in  prismatic 
needles,  readily  soluble  in  water. 

When  boiled  with  water,  cocaiu  is  hydrolysed  into  bcnzoylecgonin, 
CifiHinNOi,  and  methylic  alcohol.  If  the  hydrolysis  be  effected  by 
BaH202,  or  by  concentrated  mineral  acids,  it  is  more  complct'3,  and 
ecgonin,  benzoic  acid  and  methylic  alcohol  are  formed.  Cocain  is, 
therefore,  the  methyl  ester  of  bcnzoylecgonin ,  and  ecgonin  is  tropin - 
5-monocarboxylic  acid: 


Hvr.CH- 


'Cn 


N.rrij     CH 

f  I 

HjC.CH CH2 

Tropidin, 


I 
N.CHj 

I 


-C.COOH 

II 

CH 
I 
-CH. 


Anh  y  d  rrK*p  Ko  n  In , 


H3C.CH- 

I 


-€H, 


N.CHs 


HiC.CH- 


Tropin. 


556 


MANUAL     OF    CHEM18TKY 


-rH.COOH 


I  1 

N.CHa      CHOH 

I  I 

H;C.CH CHa 

Eeconln. 
TroptD'S-Cfirboxylie  Mid. 


HaCXH- 

I 


-CH.COO.CHa 


N.CHa       CHOCO.CtH* 
^  I  I 

Coca  in. 
Methyl  beiuoylfNCiKOQftte. 


Analvtical  Characters.— (1)  Pierk*  aeid  forms  a  yellow  ppt.  in 
coBceotrated  solutions.  (2)  A  solutiou  of  iodiii  in  KI  sohition  gives 
a  fine  red  precipitate  in  a  solution  eontaiuiiig  1  to  10,000  of  cocam. 
(3)  Wben  cocam  liydroclilorid  is  heated  with  eouwiitrated  H2SO4 
until  white  fumes  are  given  off  abundaotly,  and  potassium  iodate  is 
added  to  the  still  hot  liquid,  abundant  violet  vapors  are  given  off,  and 
the  liquid  bet^omes  deep  red -violet,  changing  to  brilliant  green,  then 
to  pink,  and  finally  to  pure  blue*violet.  (4)  Potassium  permanganate 
produces  a  violet,  crystalline  ppt.  (5)  A  5  per  cent*  solution  of 
chromic  acid  produces  an  orange- colored  ppt.,  which  immediately 
redissolves.  but,  after  addition  of  HOI,  remains  permanent.  (6)  If 
cocam  hydryehh>rid  be  mixed  dry  with  HgaCb,  the  white  mixture  in 
moi^t  air  turns  gray  or  black*     Pilocarpin  gives  the  same  reaction. 

Pilocarpin — CnHieNjO-j  —  occurK  in  jaborandi,  along  with  two 
other  alkaloids,  jaborin,  0221132X404 (!) ,  and  pilocarpidin,  CinHi4X202, 
and  an  essential  oil,  consisting  principally  of  pilocarpenCp  CioHi^.  It 
is  colorless,  erj'stalline,  readily  sohible  in  water,  alcohol,  ether  and 
chloroform.  It  is  converted  by  heat  into  jaborin;  and  by  HNO3  or 
HCl  into  a  mixture  of  jaborin  and  jaborandin,  C10H12N2O3.  Like 
piperin,  atropin,  eocaia»  etc.,  it  is  ethereal  in  character  and  is  decom- 
posed into  CO2,  methylamin,  butyric  acid,  and  pyridin  bases  by  KHO 
or  NaHO.  When  oxidized  by  potassium  permanganate  it  yields 
P3fridin-tartronicacid»  C5H4N.C  :  {0H)(CO0H>2,  and  this,  on  further 
oxidation,  nicotinic  acid,  C&H4N.COOH.  When  its  hydrochlorid  is 
heated  to  20i.)^,  in  presence  of  H2O,  it  takes  up  water  and  is  decom- 
posed into  pilocarpidin  and  met  by  lie  alcohoL  Conversely,  pilocarpin 
is  produced  by  the  action  of  methyl  iodid  upon  pilocarpidin. 
Although  the  constitution  of  pilocarpin  is  not  established,  the  above 
and  otiier  reactions  indicate  that  it  contains  the  pyridin  ring,  to 
which  the  (cyclic  group,  ChHuNO^,  is  attached  in  the  ^  position;  and 
that  it  is  methyl- pilocarpidin. 

QuinoUn  Alkaloida — Cinchona  Alkaloids*— Althongh  by  no  means 
so  complex  a  substance  as  opium,  cinchona  hark  contaius  a  gr«at 
number  of  substances:  guhiin,  cinehonin,  qninidin^  cinchonidin ,  ariein^ 
ffuinip,  qmnoiamiie  and  qHtnovfe  fwfds;  rivrhona-red,  etc.  Of  these 
the  most  important  arc  quiniu  and  cinclionin. 

Quinin  — Quinina  (U.  SJ— C2oH34N202+n  Aq-'a24+ttl8— exists 
in  the  bark  of  a  variety  of  trees  of  the  genera  Cinchona  and  Chinas 


4 


ALKALOIDS 


557 


rary  eonsiderably  in  their  richness  in  this  alkaloid.  The 
nples  of  calisaja  bark  contain  from  30  to  32  parts  per  1»000 
of  the  sulfate;  the  intermediate  grades  4  to  20  parts  per  1,000 j 
inferior  grades  of  bark  contain  from  mere  traces  to  6  parts  per 
1,000. 

It  is  known  in  three  different  states  of  hydration,  with  1,  2,  and  3 
Aq,  and  anhydrons.  The  anhydrous  form  is  an  amorphous^  resinous 
substance,  obtained  by  evaporation  of  solutions  in  auhydrons  alcohol 
or  ether.  The  first  hydrate  is  obtained  in  crystals  by  exposing  to 
air  recently  precipitated  and  well -washed  quiuin.  The  second  by 
preetpitating  by  ammonia  a  solntion  of  quinin  sulfate,  in  which  H 
has  been  previously  Ubenited  by  the  action  of  Zu  upon  Il-iSO^;  it  is 
a  greenish,  resinous  body,  which  loses  H2O  at  150°  (302"^  FJ.  The 
third,  that  to  which  the  following  remarks  apply,  is  formed  by  pre- 
cipitating solutions  of  quiuin  salts  with  ammonia. 

It  crystallizes  in  hexagonal  prisms;  very  bitter;  fuses  at  57° 
(134.6°  F.};  loses  1  Aq  at  100^*  (212°  FJ,  and  the  remainder  at  125° 
(257'^  FJ;  becomes  colored,  swells  up,  and,  finally,  burns  with  a 
smoky  flame.  It  does  not  sublime.  It  dissolves  in  2,2(X)  |its.  of  cohl 
water,  in  763  of  hot  water,  very  soluble  in  alcohol  and  chloroform; 
soluble  in  amyl  alcohol,  benzene,  fatty  and  essential  oils,  and  ether. 
Its  aleoholie  solution  is  powfrfnlly  Ifevogyrous,  [(/]p^=^ — 270.7°  at  18° 
(61,4"  F.),  which  is  diminished  by  increase  of  temperature,  but  in- 
creased by  the  presence  of  acids. 

Analytical  Characters.— (1)  Dilute  H2SO4  dissolves  quinin 
in  colorless  but  fluorescent  solution  (see  below).  (2)  Solutions  of 
i^uinin  salts  turn  green  when  treated  with  chlorin -water  and  then 
with  ammouiura  hydroxid.  (3)  Chlorin  passed  through  water  hold* 
ing  quiuin  in  suspension  forms  a  red  solution.  (4)  Solution  of 
quinin  treated  with  chlorin -water  and  then  with  fragments  of  po- 
tassium ferrocyauid   becomes  pink,  passing  to  red. 

Sulfate — Diiiidftftf—Quininm  sulfas  (U.  SJ  — Quiniae  sulfas 
(Br.)— S04(C2idir-N-On)2+7Aq— 746-f  126— crystallizes  in  prismatic 
needles;  very  light;  intensely  bitter;  phosphorescent  at  100°  (212° 
F.);  fuses  readily;  loses  its  Aq  at  120'^  (248^  F.),  turns  red,  and 
finally  carbonizes;  effloresces  in  air,  losing  6  Aq;  soluble  in  740  pts. 
of  water  at  13''  (55.4"*  F),  in  30  pts.  of  boiling  water,  and  60  pts.  of 
alcohol.  Its  solution  with  alcoholic  solution  of  iodin  deposits  bril- 
liant green  crystals  of  iodoquinin  sulfate. 

Hydrosulfate— Quininec  bisulfas  (U.  S.)^-S04H(C2oH25N202)  + 
7  Aq  — 422+126— is  formed  when  the  sulfate  is  dissolved  in  excess 
of  dilute  H2SO4.  It  crystallizes  in  long,  silky  needles,  or  in  short, 
rectangular  prisms;  soluble  in  10  pts.  of  water  at  13°  (59*^  F.).  Its 
solutions  exhibit  a  marked  fluorescence,  being  colorless,  but  showing  a 


558 


ilANUAL    OF    CHEMISTEY 


I 


fine  pale -blue  color  when  illmuinated  by  a  bright  light  against  a 
dark  background. 

By  the  action  of  alkalioe  hydroxids  upon  qninin,  formic  acidj 
quiuolin  (p.  543),  and  pyridiu  bases  (p.  517)  are  produced. 

Coneeutrated  HCl  at  MO'^-l^O"*  (284°-302''  F.)  deeoniposes  qumm 
with  separatioD  of  ojethyl  ulxiorid  and  formation  of  apoquinioi  Ci»- 
IT22X2O2,  an  amorphous  base*  H 

Oxidizing  agents  produce  from  qninin  oxalic  acid  and  pyridin  ear- 
boxy  lie  aeidis,  notably  pyridin-2,  S -di  car  boxy  Uc.  or  cinchomeronic, 
acid,  CsHsNtCOOFDai  which  are  also  formed  by  oxidation  of  ein- 
chonin, 

Althongh  cinchonin  differs  from  quiuin  in  composition  by  CH2O, 
and  althongh  the  decompositions  of  the  two  bases  show  them  both  to 
be  related  to  the  quinolin  and  pyridin  bases,  attempts  to  convert  cin- 
chcnin  into  quinin  have  resulted  only  in  the  formation  of  other 
products,  among  which  is  an  isomere  of  quinin ,  oxycinchonin. 

Methylquinini  C2qH24N202CH3»  is  a  base  which  has  a  curare-like 
action .  ■ 

Cinchonin— Cinchonina  (U.  Sj— C10H23N2O — 294— occurs  in  Pe- 
ruvian bark  to  the  amount  of  from  2  to  30  pts.  per  1.000.  It  crys- 
tallizes without  x\q  in  colorless  prisms;  fuses  at  150*^(302^F.) ;  soluble 
in  3,810  pts.  of  water  at  10"^  (50*^  F.),  in  2,500  pts.  of  boiling  water; 
in  140  parts  of  alcohol,  and  in  40  pts.  of  chloroform.  The  salts  of 
cinchonin  resemble  those  of  qninin  in  composition;  are  quite  soluble 
in  water  and  in  alcohol;  are  not  fluorescent;  are  permanent  in  air;  _ 
and  are  phosphorescent  at  100°  (212°  F.).  ■ 

Quinidin  and  Quinicin— are  bases  isomeric  with  qninin  ;  the 
former  occurring  in  cinchona  bark,  and  distinguishable  from  quinin 
by  its  strong  dextrorotary  power;  the  second  a  product  of  the  action 
of  heat  on  quinin,  not  existing  in  cinchona.  ^ 

Cinchonidin— a  base,  isomeric  with  cinchonin,  occurring  in  cer*B 
tain  varieties  of  barkj  lasvogyrous.     At  130''  (266^^  F.),  H2SO4  con- 
verts it  into  another  isomere,  cinchonicin.  m 

Constitution  of  Cinchona  Alkaloids — The  constitution  of  no^ 
cinchona  alkaloid  has  yet  been  completely  detcrniined.  Enough  has, 
however,  been  ascertained  to  show  that  cinchonin  and  quinin  con- 
tain a  quinolin  nucleus,  united  to  another  cyclic  nuelens,  containing 
the  second  N  atom,  and  which  is  probably  a  modified  piperidin.  The 
difference  between  the  empirical  formula  of  cinchonin,  CittHaNjO* 
and  of  qninin  t  C20H24N2O21  is  CH2O  in  favor  of  the  latter,  which 
would  represent  the  substitution  of  methoxyl,  CHr^O,  for  H,  When 
cinchonin  and  qninin  are  oxidized  b^-  chromic  acid  they  yield  tw^ 
quinolin -earboxylie  aeids  also  differing  from  each  other  by  CH2O. 
Cinchonin  yields  einchoninic  acid,  which  is  known  to  be  y- quinolin 


ALKALOIDS 


559 


carboxylic  acid;  while  quinin  yields  quinic  acid,  which  has  been 
shown  to  be  the  methyl -phenol  ether  of  p-oxyquinolin- 7- carboxylic 
acid  (see  formnlee  below).  Therefore  the  group  CH2O,  by  which 
cinchonin  and  quinolin  differ,  exists  in  the  quinolin  ring,  and  the 
"second  half,"  or  the  portion  of  the  molecule  other  than  the  quinolin 
ring,  is  the  same  in  the  two  alkaloids.  This  is  further  proven  by  the 
fact  that  on  decomposition  by  PGI5  and  subsequent  treatment  with 
alcoholic  KHO,  cinchonin  yields  lepidin,  C10H9N,  the  next  superior 
homologue  of  quinolin,  C9H7N,  while  quinin  yields  p-methoxy- lepidin, 
CioH«(OCH3)N,  and  the  other  product  of  the  decomposition  is  one 
and  the  same  substance  from  either  alkaloid,  a  substance  which  has 
been  called  meroquinene,  C9H15NO2,  which  on  treatment  with  HgCk 
and  HCl  is  converted  into  ^-ethyl-7-methyl-pyridin,  and  whose  prob- 
able constitution  is  expressed  by  the  formula  given  below.  So  far  as 
determined,  therefore,  the  formulee  of  cinchonin  and  of  quinin  are 
those  here  given,  the  arrangement  of  the  group  CioHi5(OH)N 
remaining  to  be  determined : 


H       COOH 

1        1 

c     c 
^\  /\ 

HC        C        CH 

1         II         1 
HC        C        CH 

YY 

1 

H       COOH 

CH3O.C        C       CH 
1         II         1 
HC        C        CH 

\/   \^ 

C       N 
1 

H    CHa. COOH 

\/ 

C 
/\    /H 
H2C        C^ 

"^CHrCHj 

H2C       'CHa 

N 

H 

H 

1 
H 

Cinehoninie  add. 
(7-<iainolin  ear* 
bozyUc  acid). 

Qnlnieaeid.  OMeth- 

oz7qainoIin-7-ear- 

boTjUc  acid). 

MeroQuinene  (f) 

CHa 

1 

H       CioH,5(OH)N 

HC       C        CH           CB 

1         II         1 
HC        C        CH 

\-^  \^ 
C        N 

1 

H       CioHi6(OH)N 

1 
C 

HC       C-CH2.CH3 

1         II 
HC        CH 

Y 

1      i 

c     c 

^\  /\ 

[3O-C        C        CH 

1         II          1 

HC        C        CH 

\/   \^ 

C       N 
1 

A 

1 
H 

Ihylrmethjlwrrldln. 

Cinchonin. 

Quinin. 

Alkaloids  of  the  Loganiacese — Strychnos  Alkaloids. — This  group 
includes  strychnin  and  brucin  and  their  alkyl  derivatives,  and  the 
curare  alkaloids. 

Strychnin  —  C21H22N2O2 — exists  in  the  seeds  and  bark  of  different 
varieties  of  Strychnos,  notably  Strychnos  nux-vomica. 

It  crystallizes  on  slow  evaporation  of  its  solutions  in  orthorhombic 


560 


MAmJAL    OF    CHEMISTRY 


prisras;  very  sparingly  soluble  in  water  and  in  strong  alcohol;  soluble 
in  5  parts  of  chloroform.  Its  aqiieons  solution  is  intensely  bitter,  the 
taste  being  perceptible  in  a  solution  eoutainmg  1  part  in  200,000. 

It  is  a  powerful  base^  nentralizes  and  dissolves  in  concentrated 
H2SO4  without  coloration,  and  precipitates  many  metallic  oxidti  from 
solutions  of  their  salts.  Its  salts  are  mostly  crystallizable,  solnble  in 
w^ater  and  in  alcohol,  and  intensely  bitter.  The  acetate  is  the  most 
soluble.  The  neutral  Rulfate  crystallizes,  with  7  Aq,  in  rectangular 
prisms.  Methyl  and  ethyl  tod  ids  react  with  stryehnin  to  produce 
methyl  or  ethyl strychnium  iodids»  white,  crystalline  substances, 
producing  au  action  on  the  economy  similar  to  that  of  curare.  Heated 
with  fuming  HNO3,  strychnin  yields  pi(*rie  acid.  Heated  with  barjta 
water  to  130"^,  it  yiehls  isostrychnic  acid,  (^oyHiaN-iO.COOH;  and 
when  treated  with  sodium  alcoholatr,  strychnic  acid,  by  addition  of] 
H2O.  By  boiling  with  concentrated  hydriodic  acid  and  red  phos 
phorus  it  is  converted  into  desoxystrychnin,  CiiiH2r,X20,  which  is 
further  reduced  by  electrolysis  to  dihydrostrychnolin,  C-jiHiaNi. 
Htrycliuin  itself,  by  electrolysis,  forms  two  bases,  tetrahydro- strych- 
nin, C^in^tjN^jOi:,  and  strychnidin,  CjiH-iNtiO.  But  little  is  known 
id  the  constitution  of  stryehnin,  which  is,  however,  probably  a  de- 
rivative of  tetrahydroquinolin. 

Analytical  Characteks. — (1)  Dissolves  in  concentrated  H2SO4, 
without  color,     Tlic  sohitiou  deposits  strychnin  when   diluted  with^ 
water,  or  when  neutralized  with  magnesia  or  an  alkali.      (2)   If  a 
fragment  of   potassium  dichromate   {or  other  substance  capable  of 
yiekliug  nascent  oxygen)  be  drawn  through  a  solution  of  strychnin  in 
H2SO4,  it  is  followed  by  a  streak  of  color;   at  first  blue  (very  transi- 
tory and    frequently  not    observed),   then    a    brilliant  violet,  whii'h 
slowly  passes  to  rose -pink,  and  finally  to  yellow.     Reacts  with  tootttt 
grain  of  strychnin.     (31  A  dilute  solution  of  potassium  dichromate 
forms  a  yellow,  crystalline  ppt.  in  strychnin  solutions,  which,  when 
washed  and  treated  with  concentrated  H^SOi,  gives  the  play  of  colors, 
indicated  in  2.     {4}  If  a  solution  of  stryelinin  be  evaporated  mi  a  bit:^ 
of  platinum  foil,  the  residue  moistened  with  concentrated  H^SO*,  the^ 
foil  couneeted  with  the  +  pole  of  a  single  Urove  cell,  and  a  plat  in nn*^ 
wire  from  the  —  pole  brought  in  contact  with  the  surface  of  the  acid,^ 
a  violet  color  appears  upon  the  surface  of  the  foil.     (5)  Strychnic^ 
and  its  salts  are  intensely  bitter,     (6)  A  solution  of  strychnin  intro — 
dneed   under  the   skin  of   the  back  of  a   frog   causes  difficulty  0 
respiration  and  tetanic  spasms,  which  are  aggravated  by  the  slighter 
irritation,  and  twitching  of  the  muscles  during  the  intervals  betwee 
the  convulsions.   With  a  small  frogj  ts-J-ott  grain  of  strychnium  acetate 
will  produce  tetanic  spasms  in  ten  minutes.     White  mice,  14  to  1^ 
days  old,  are  even  more  susceptible  to  the  action  of  strj'chnin  thao 


I 
I 


fi — 


ALKALOIDS 


S61 


frogs.  (7)  Solid  strychnin,  moistened  witb  a  solution  of  iodic  acid  in 
H2SO4,  prodiiees  a  j^ellow  cfjlor,  elmnging  to  brick-red,  and  then  to 
vititet-red.  (8)  Moderately  con t!cnt rated  ONO;*  colors  stryclniin  yellow 
in  the  cold.  (9)  A  warm  solntion  of  strychnin  in  dihite  HNO:i  pro- 
dnces  a  scarlet -red  color  on  addition  of  a  little  KiUOs*  A  drop  or  two 
of  ammonia  chaug:es  this  to  brown.  On  evaporation  to  dryness,  a 
green  residue  remains,  which  forms  a  green  solution  in  water,  changes 
to  orange -brown  with  KHO,  and  returns  to  green  with  HNO3. 

Toxicology. —  Strychnin  produces  a  sense  of  suffocation,  thirst, 
tetanic  spasms,  usually  opisthotonos,  sometimes  emprosthotonos,  oc- 
casionally vomiting,  contraction  of  the  pupils  during  the  spasms, 
and  death,  either  by  asphyxia  during  a  paroxysm,  or  by  exhaustion 
daring  a  remission.  The  symptoms  appear  in  from  a  few  minutes  to 
an  hour  after  taking  the  poison,  usually  in  less  than  twenty  minutes; 
and  death  in  from  five  minutes  to  six  hours,  nsuaily  within  two  hours. 
Death  has  been  caused  by  %  grain,  and  recovery  has  followed  the 
taking  of  20  grains. 

The  treatment  should  consist  in  bringing  the  patient  under  the 
influence  of  chloral  hydrate  or  of  chloroform,  and  then  washing  out 
the  stomach.  The  patient  should  be  kept  as  quiet  as  possible,  as 
the  slightest  unexpected  irritation  will  produce  a  spasm. 

Strychnin  is  one  of  the  most  stable  of  the  alkaloids,  and  may 
remain  for  a  long  time  in  contact  with  putrefying  organic  matter 
without  suffering  decomposition. 

Brucin  —  C2:iH3oN2C>4+  4Ar|—  394  +72  —  accompanies  strychnin. 
It  forms  oblique  rhomboidal  prisms,  which  lose  their  Aq  in  dry  air. 
Sparingly  soluble  in  H-^O,  readily  soluble  in  alcohol,  chloroform,  and 
amyl  alcohol  j  intensely  bitter.  It  is  a  powerful  base  and  most  of 
its  salts  are  soluble  and  crystalline.  Its  action  on  the  economy  is 
similar  to  that  of  strychnin,  but  much  less  energetic. 

Analytical  Characteks.  —  ( 1 )  Concentrated  IINO3  colors  it 
bright  red,  soon  passing  to  yellow;  stannous  chlorid,  or  colorless 
NH4H8,  changes  the  red  color  to  violet.  (2)  Chlorin- water,  or  CI, 
colors  brucin  bright  red,  changed  to  yellowish -brown  by  NH4HO. 

Curarin^ — C3eH35N(T)-^  is  an  alkaloid  obtainable  from  the  South 
American  arrow* poison,  curare,  or  woorara.  It  crystallizes  in  four- 
sided,  coloriess  prisms,  which  are  hygroscopic,  faintly  alkaline »  and 
intensely  bitter. 

Curarin  dissolves  in  H2SO41  forming  a  pale- violet  solntion,  which 
slowly  changes  to  red.  If  a  crystal  of  potassium  dichromate  be 
drawn  through  the  H2SO4  solution,  it  is  followed  by  a  violet  colora- 
tion, which  differs  from  the  similar  color  obtained  with  strj'chniu 
under  similar  circumstances,  in  b^ing  more  permanent,  and  in  the 
absence  of  the  following  pink  and  yellow  tints. 
M 


MANUAL    OP    CHEMISTRY 


prof 


Isoqiunolin  and  PMnanthrenf'  Alkalohh.—The  opium,  Hydrastis, 
berberis  and  eorydalis  alkaloids  are  id  eluded  in  these  groups.  Of  the 
opium  alkaloids,  papaveriti,  uarcotio  aud  narcem  are  certainly  deriva- 
tives of  isoquiuolin.  Morphin  and  codein,  on  the  other  baud,  do  not 
contain  the  isoqiiiiiolin  nucleus,  but  a  pbenanthrene  nucleus;  having 
nitrogen*eontainiiig  ring  condensed  upon  it.  But  until  the  consti 
tion  of  these  two  alkaloids  is  established  with  more  completeness 
is  not  desirable  to  separate  them  from  their  congeners  {see  p,  565). 

Opium  Alkaloids* —  Opium  is  the  dried  juice  obtained  by  makinir 
incisions  in  the  unripe  capsules  of  the  poppy,  Fapaver  somnifemm. 
It  is  of  exceeding  complex  composition,  and  contains  meconic  (p.  517) 
lactic  and  sulfuric  acids,  with  which  the  alkaloids  are  in  combinatio] 
meconin   (p.  462),  gum,  caoutchouc,  wax,  sugar,  resins,  etc.,  aud  a 
number  of   alkaloids.     Some  twenty  alkaloids   have    been  obtain 
from  opium,  but  of  these  several  are  probably  produced  by  the  p 
cesses  of  extraction.      The  most  important  of  the  natural  alkaluids" 
and  the  average  percentage  in  which  they  exist  in  opium  of  good 
quality  are:    raorphin,  10%;  narcotin,  6%;   papaverin,  1%;  codeii)» 
0,S%-    narceiu,  0,2%;   and  thebaln.  0.15%, 

Morphin—  Morphina  (U.  SJ  —  CiTHiuNOa+Aq— 285+18  — cry 
tallizes  in  colorless  prisms j  odorless,  but  very  bitter;  it  fuses  at  120*, 
losing  its  Aq.    More  strongly  heated,  it  swells  up,  becomes  carboDkjH 
izptl,  and  finally  burns.    It  is  soluble  in  1,000  pts,  of  cold  water,  l^ 
400  pts.  of  boiling  water;   in  265  pts.  of  alcohol  of  90  per  cent.  '&^ 
10^,  and  in  33  pts,  of  boiling  alctdiol  of  the  same  strength;   in  3*^^ 
pts*  of  cold  amyl  alcohol,  much  more  soluble  in  the  same  liquid  warxJ^i 
almost  insoluhle  in  aqueous  ether;   rather  more  soluble  in  alcohc^^^^ 
ether;   almost  insoluhle  in  benzene;    soluble  in  2,500  pts.  of  chlo  ^*^' 
form  at  9°,  and  in  45  pts.  at  56*^,    All  the  solvents  dissolve  morp' 
more  readily  and  more  copiously  when  it  is  freshly  precipitated 
solutions  of  its  salts  than  vvht*n  it  has  become  crystalline,  

Morphin  combines  with  acids  to  form  crystallizable  salts,  of  wlfc-^  ^^ 
the  hydrochloride  sulfate  and  acetate  are  used  in  medicine*  If  n^^^^ 
phin  be  heated  for  some  hours  with  excess  of  HCl,  under  pressu:^^' 
to  150°  (302°  FJ.  it  loses  water,  and  is  converted  into  a  new  bas-^H 
apomorphin,  Ci7HnN02.  ^^ 

By  heating  together  acetic  anhydrid  and  morphin,  acety Imorpl"* ^^^ 
CnHi«(C2aiO)N03,  and  diacctylmorphin,  CnHn(C2HaO)2N03,  ^^ 
formed.  The  latter  is  used  as  a  medicine  under  the  name  hfr€f^fi^ 
Similarly  substituted  butyryl-,  benzoyl-,  auccinyl-,  camphor 
methyl-,  and  ethyl- morphin,  are  also  known.  The  last  uanied 
used  medicinally  under  the  name  dnmin. 

Morphin  is  readily  oxidized  and  is  a  strong  reducing  agent. 
reduces  the  salts  of  gold  and  silver  in  the  cold.     It  is  oxidized  by«t- 


,11 


"1 


ALKALOIDS 


563 


well  as  bv  nitre 


I 


I 


I 


I 


mosplieric  oxygen  when  it  is  in  alkaliue  .sol ut ion 
aeid,  potassiuia  peniiaiio^anate,  potasisium  ferrieyauid^  or  aminouiaeal 
eiiprie  sulfate^  with  tlm  foruiatioii  of  a  uoti- toxic  conipoiiad  which  has 
received  th**  names,  pseudomorphin,  oxymorphin,  oxydimorphin, 
and  dehydromorphin  (<-i7NimN03)2,  whose  molec^nle  consists  of  two 
morphin  molecules,  nnited  with  loss  of  H-i.  Morphin-sulluric  acid, 
properly  morphylsulfuric  acid,  or  monftmorphifl  stdfafe,  OigH^NU^.O.- 
SOjH.  corresponds  to  ethyl  snlfnrie  aeid  and  phenyl  sulfuric  aeid, 
and  is  obtained  by  the  same  method  as  the  latter  componud  (p.  470) 
from  morphin.  It  contains  H2O  loss  than  loorphiom  sulfate,  from 
which  it  differs  in  that  the  acidyl  is  attaehed  through  a  hydroxy  I, 
whereas  in  the  salt  it  is  attached  to  the  nitrogen.  When  morphin  is 
adrainstered  it  appears  in  the  urine  as  psendomorphin,  and  also  pro- 
bably as  morphylsulfuric  acid,  both  of  which  are  non -toxic.  When 
morphin  is  distilled  with  powdered  zinc?,  tlie  principal  product  of  the 
reaction  is  phenanthreue,  accompanied  by  ammonia,  trimethylamin, 
pyrrole,  pyridin,  and  a  product  having  the  form n hi  CnHuN,  probably 
phenanthrene  -  qninolin . 

The  salts  of  morphinm  are  crystalline.  The  acetate  is  a  white 
erystalline  powder,  soluble  in  12  parts  of  water,  which  decomposes 
CD  exposure  to  air,  with  loss  of  acetic  acid.  The  chlorid  is  less  sol* 
uble,  but  more  permanent  than  the  acetate.  The  i?ulfute  is  the  form 
in  which  morphin  is  the  most  frequently  used  in  medicine.  It 
is  a  very  light,  crystalline,  feathery  powder ;  odorless,  bitter,  and 
neutral  in  reaction.  It  dissolves  in  24  parts  of  whaler.  Its  solutions 
deposit  morphin  as  a  white  precipitate  on  addition  of  an  alkali.  The 
crysUls  contain  5  Aq,  which  they  lose  at  130°  (266  FJ. 

Akalttical  Characters. — (I)  It   is  colored   orange,  changing 
to  yellow,  by  HXO3.     {2}  A  neutral  solution  of   a  morphinm  salt 
j?ives  a   blue  color  with  neutral    sohition  of   ferric  chlorid.     (3)  A 
soladoii  of  molybdic  acid  in  H2SO4  (Frcihde's  reagent)  gives  with 
riiorphin   a  violet   color,  changing   to   blue,  dirty  green,  and   faint 
pink.    Water  discharges  the  color.     (4)   Take  two  test-tubes.     Into 
One  (a)   put  the  solution  of  morphin,  into  the  other  (b)  an  equal 
Hnlk  of   H2O.     Add   to  each  a   granule  of  iodic  acid  and  agitate; 
<i  becomes  yellow  or  brow^n,  b  remains  colorless.      To  each  add  a 
small  drop  of  chloroform  and   agitate:   the  CHCla  in  a  is  colored 
"Violet,  that  in  h  remains  colorless.     Float  some  very  dilute  am  mo- 
il ium  hydroxid  solution  on  the  surface  of  the  liquid  in  «;  a  brown 
^and  is  formed  at  the  junction  of  the  layers.     (5)  Moisten  the  solid 
'naterial  with  HCl  to  which   a  small   quantity  of  H2SO4  has  been 
^dded,  and  heat  in  an  air  oven  at  110°  until  HCl  is  expelled:  a  violet- 
Colored  liquid  residue  remains*     Add  to  this  a  drop  or  two  of  water 
containing  a  little  HCl,  and  neutralize  with  powdered  sodium  bicar* 


S64 


MANUAL    OF    CHEMISTRY 


r 


bonate  in  slight  excess^   a  piyk  or  rose  color  is  produced,  most  dia- 

tioctly  visible  oti  the  bubbles.  Add  a  drop  of  water  and  a  drop  or  two 
of  aleoholie  solutiou  of  iodia:  a  green  color  is  de%^eloped.  This  reac- 
tion, knowu  as  the  Pellagri  test,  is  based  upon  the  conversion  of 
morphiii  into  apomorphiu,  and  cousequently  reacts  with  that  alkaloid. 
(6)  Moisten  the  solid  with  concentrated  H2SO4,  aud  heat  cautiously 
until  white  fonies  begin  to  be  given  off,  cool  and  touch  the  liquid  with 
a  glass  rod  moistened  with  dilnte  HNOa:  a  fine  blue -violet  color, 
changing  to  red  and  then  to  orange*  If  the  H2SO4  contains  oxids  of 
nitrogen,  as  it  usually  does,  a  violet  tinge  will  be  produced  before 
ftdditiou  of  HNO3,  but  then  becomes  much  more  intense.  This  reac- 
tion, known  as  the  Hnseniaun,  may  be  applied  by  allowing  the  solid 
to  remain  in  contact  with  H2SO4  for  fifteen  to  eighteen  hours  in  plaee 
of  heating.  (7)  Marquis^  reagent  (3  ec.  concentrated  H2S04H-2gtt, 
formalin)  gives  a  brilliant  red -violet  color.  These  are  the  most 
important  tests  for  morphin,  and  affirmative  results  with  all  of  them 
prove  the  presence  of  that  alkaloid.     There  are  many  others. 

Codein—Codeina  (IT.  S.)—CiHH2iN0.T+Aq— 299+18— crystallizes 
in  large  rhombic  prisms,  or  from  ether,  without  Aq,  in  octahedra; 
bitter;  soluble  in  80  pts,  cold  water;  17  pts.  boiling  water;  very 
soluble  in  alcohol,  ether,  chloroform,  benzene;  almost  insoluble  in 
petroleum -ether. 

Codein  is  the  methyl  ether  of  morphin,  or  its  superior  homologut^t 
and  resembles  that  alkaloid  in  some  of  its  reactions;  thus  under 
similar  eirenmstances  both  form  apornorphin;  and  morphiu  may  be 
converted  into  codein  by  the  action  of  methyl  iodid  in  the  presence  ^^f 
KHO.  Codein,  howe%*er,  only  contains  one  OH  group,  and  fornjs  » 
monoaeetyl  derivaiive  with  acetyl  chlorid,  while  morphin  producfS  & 
diaeetyl  compound. 

Narcein  —  C2jH2TN08+2Aq— 463+36— crystallizes  in  bitter,  pri^** 
niatic  needles;  sparingly  soluble  in  water,  alf*ohol,  and  amyl  ak'oliol; 
insoluble  in  ether,  benzeue,  and  i>etroleum -ether. 

Narcotin  —  C22H2;iNO:— 413  —  crystallizes  in  transparent  pristfl-^' 
almost  insoluble  in  water  and  in  petroleum -ether;  soluble  in  nkolm^ 
ether,  benzene,  and  chloroform.  Its  salts  are  mostly  uncrystalUz^^^^' 
unstable,  and  readily  soluble  in  water  and  in  alcohol, 

Narcotin   is  decomposed   by  Il-O  at    140°  {284''  FJ,  by  dil»^* 
H28O4,  or  by  baryta,  with  formation  of  opianic  acid»  CioHiuOs,  ^^^ 
hydrocotarnin,  CioHiaXOn.     Rediiciug  agents  decompose  it  into  br 
drocotarnin  and  meconin,  CioHio04»      Oxidizing   agents  convert  i*| 
into  opianic  acid  and  cotamin,  Ci2HKiN03. 

Papaveriii^'C2oH2iN04^ crystallizes  in  prisms;  almost  insoln^ftj 
in  water,  easily  soluble  in  chloroform  and  in  hot  alcohol.  It  "^l 
optically  inactive.     It  forma  a  colorless  solution  with  coneentrat€4| 


1 


ALKALOIDS 


565 


I 


^ 
I 


H'iSOi,  whif^li  turns  dark-violet  when  heated.  Acetic  anhydrid  lias 
no  action  upon  it. 

Thebain  —  Paramorphin  —  CieH^jiNOa — 311 — crystallizes  in  white 
plates;  tasteless  when  pure;  insoluble  in  water,  soluble  in  alcohol, 
ether  and  benzene. 

Apomorphin  — CnHnNO:*— is  used  hypodermically  as  an  emetic 
ID  the  shape  of  the  chlorid.  It  is  obtained  by  scaling  morpbin,  with 
an  excess  of  strong  HCl*  in  a  thick  glass  tube,  and  beating  the 
whole  to  140°  (252'^  F.)  for  two  to  three  hours.  It  is  obtained 
also  by  the  same  process  from  codem*  The  free  alkaloid  is  a  white, 
amorphous  solid,  difficultly  soluble  in  water.  The  chlorid  forms 
colorless,  shining  crystals,  which  have  a  tendency  to  assume  a  green- 
ish tint  on  exposure  to  light  and  air.  It  is  odorless^  bitter  and 
neutral;  soluble  in  6.8  parts  of  cold  water. 

Relations  and  Constitution  of  the  Opium  Alkaloids.— The  al* 
kaloids  of  opium  may  ha  arranged  in  two  groups:  (I)  lueluding 
those  which  are  strong  bases,  are  highly  poisonous,  and  contain  three 
or  four  atoms  of  oxygen;  (II)  those  which  are  weak  bases  and  eon* 
tain  four  to  nine  oxygen  atoms.  So  far  as  known,  the  alkaloids  of 
the  first  group  contain  the  phenanthrene-pyridin  nucleus,  while  those 
of  the  second  group  are  derivatives  of  isoquinolin.  The  six  principal 
alkaloids  above   mentioned    are   equally   divided    between    the   two 

groups: 

I.  11. 

Papaverin C-ioH^iNOi 

Narcotm CjiH^jNOt 

Nftrcetn GsaHjfNOs 


Morphin CnHiBNOg 

rodipin Ci^H^iNOa 

Theb&in CiftHnNOa 


Papaverin  was  first  recognized  as  an  isoquinolin  derivative.  On 
oxidation  of  papaverin  by  potassium  permanganate,  papaveraldin, 
CaHi^NOs,  is  fonned.  This,  on  fusion  with  caustic  potash,  yields 
veratrie  acid,  which  is  3»  4 -dimethoxy- benzoic  acid,  CflHs.COOH; 
(OCHa)«3.4»,  and  dimethoxyisoqninolin,  the  eonstitution  of  the  latter 
being  established  by  its  further  deeom position  into  metahemipinic 
««id  and  a-jS-y-pyridin- tricarboxylic  acid.  The  relations  of  papaverin 
^d  its  products  of  decomposition  are  shown  by  the  following  formula: 


BiCO-C 
HiOO-C 


H         H 

\  /  \ 

C  CH 

II  I 

C  N 

N  /  \  / 

c       c 

I      I 

H         H 

DimetHoxylio- 
guliioUa. 


CCK>H 

I 


/ 


HC 

II 

HC 


\ 


CH 

I 

C— OCH, 


C 

I 
OCHj 

Vfi'Mit ric  arid, 
(3,  4  mmethoxy^beniolc  mdd). 


H 

/   \ 
HaCO-C  C— COOH 

H3CO— 0  C— COOH 

V 

I 
H 

Metahrmipink  acid, 
(4, 5'Diiiiethoxy-o-phthKlk  MldK 


566 


MANUAL    OP    CHEMISTRY 


H         H 

I  I 

C  C 

^  \  /  \ 
HjCO— C  C  C- 


-CH, 

I 


H3CO— C  C  N     HC  CH 

\  /  \  ^ 
C  C 

II 

H         H  HC  C— OCH3 

\  ^ 
C 


H 

I 
C 

/  \ 
HOOC~C  CH 

II  I 

HOOC-C  N 

\   ^ 
C 

COOH 


Ac 


H3 

P»p«Terln,  (Tetnm«thoz7-b«iizjl*a-iioqiii]iolin).  o-/5-7-PyrMiB-trtBarboryUe  add 

Narcotin,  C22H23NO7,  is  converted  by  oxidation  into  opianic  acid, 
C10H10O5  (p. 463),  and  cotamin,  C12H15NO4.  By  hydrolysis  it  yields 
opianic  acid  and  hydrocotamin,  C12H15NO8;  and  by  reduction,  meco- 
nin,  C10H10O4  (p.  462),  and  hydrocotamin.  Narcotin,  therefore, 
contains  the  nuclei  of  opianic  acid,  or  of  meconin,  and  of  hydro- 
cotamin. The  constitution  of  opianic  acid  is  known,  as  well  as 
that  of  its  reduction  product,  meconin,  but  that  of  hydrocotamin 
is  not  completely  established.  It  is,  however,  a  derivative  of  iso- 
quinolin,  containing  one  of  the  three  methoxy  gp'oups  (CH3O)  which 
exist  in  narcotin,  and  a  bivalent  group  —  O.CH2.O  —  attached  to 
the  benzene  ring;  and  a  methyl  group,  united  to  the  N  atom  in 
the  pyridin  ring. 

Narcein,  C23H27NO8,  is  formed  by  the  action  of  caustic  potash  upoa 
narcotin  iodomethylate :  C22H23NO7.CH3I  +  KHO  =  KI  +  C23H27NO8. 
Narcein  apparently  does  not  contain  an  isoquinolin  grouping,  that 
which  exists  in  narcotin  having  been  broken  in  the  above  method  of 
formation  in  such  manner  that  the  N  is  in  a  lateral  chain  in  narcein. 

Morphin,  C17H19NO3,  and  codei'n,  C18H21NO3,  are  closely  related. 
Codein  is  produced  by  the  action  of  methyl  iodid  upon  morphin- 
potassium :  C17H18KNO3+CH3I  =  KI+Ci7Hi8(CH3)N03.  It  is,  there- 
fore, methyl-morphin.  By  the  further  action  of  methyl  iodid  upon 
code'in  in  alcoholic  solution,  codein  methyl  iodid,  Ci8H2iN03:CH3l. 
is  produced,  and  this,  when  warmed  with  KHO,  is  converted  into 
methyl-morphin  methine,  C17H19NO3:  CH.CH3.  The  last-named 
substance  is  decomposed  by  acetic  anhydrid  into  methyldioxyphenan- 

threneand  oxethyl-dimethyl-amin:  Ci7Hi9N03:CH.CH3=Ci4H8\o.cS> 

/CH3 
H-  N— CH3  ;  and  other  morphin  and  codem  derivatives  are  sim- 

\CH2.CH2.OH 

ilarly  decomposed,  with  formation,  on  the  one  hand,  of  a  non-nitro- 
genized  oxy-phenanthrene  compound,  and,  on  the  other,  an  oxyani'n 
or  a  trialkyl-amin.     Upon   these  facts,  it  is  concluded,  that  the 


ALKALOIDS  567 

codein  molecules  consist  of  an  ozyphenanthrene  group, 

CHs 

I 

N 
frbich  is  fused  a  nitrogenized    group,  H2C         .    It  is  also 

H2C 
\  / 
o 

Cognized  that  the  two  hydroxyls  are  in  the  same  phenanthrene  ring, 
ad  that  one  of  them  is  phenolic,  the  other  alcoholic;  also  that  one 
'methyl  group  is  attached  to  the  nitrogen  atom.  The  disposal  of  the 
hydrogen  and  hydroxyls  in  the  phenanthrene  nucleus  and  the  position 
of  attachment  of  the  nitrogenized  group  above  referred  to  remain 
undetermined.  Two  formulae  of  constitution  of  morphin  have  been 
proposed,  either  of  which  is  in  consonance  with  the  known  facts: 

OH 

I  OH 

C  I 

/  \  c 

HOHC  CH  /  \ 

I  I  HOHC         CH 

HoC  0  II 

\  ^  \  0-HC         C 

C  CHa  I  \  ^  \ 

II  H2C  C  CH 

O  C  CHa  I  I  II 

/   \   /   \   /  HaC  C  CH 

HaC  C  C  \  /  \   / 

I  II  I  H3C— N— HC  C 

HaC  C  CH  II 

\   /   \   ^  HaC  CH 

N  C  \    ^ 

I  I  C 

CHs      H  H 

U)  (n) 

The  formula  of  codein  is  derived  from  either  formula  by  substitu- 
tion of  CHs  for  H  in  the  phenolic  OH;  that  of  apomorphin  by 
removal  of  H2O. 

ThebainjCwHaNOa,  is  decomposed  by  acetic  anhydrid  in  a  manner 
quite  aualogous  to  the  decomposition  of  morphin,  above  referred  to, 
but  yielding  a  dimethoxy- phenolic  derivative  of  phenanthrene,  called 
thebaol,  and  methyl-oxethyl-amin :  Ci9H2iN03+H20=(CH80)20i4H7.- 

/fl 
OH+N— CH3  Like  morphin  and  codein,  it  is  therefore  a 

\CHa.CHa.OH 
phenanthrene -pyridin  derivative. 

Toxicology  of  Opium  and  its  Derivatives. —  Opium,  its  prepara- 
tions and  the  alkaloids  obtained  from  it  are  all  active  poisons.  The 
alkaloids  have  not  all  the  same  action.  In  soporific  effects,  beginning 
with  the  most  powerful,  they  rank  thus:  narcotin,  morphin,  codein; 
in  tetanizing  action:  tbebain,  papaverin,  narcotin,  codein,  morphin; 
in  toxic  action:  thebain,  codein,  papaverin,  narcein,  morphin,  narcotin. 


668 


MANUAL    OF    CHEMISTRY 


The  symptoms  set  in  in  from  ten  minutes  to  three  hours,  eieep- 
tioiially  "immediately,''   or   only   after   eighteen    hoars.      They  are 
divisible  into  Lhree   peiiuJs:  (1)  a  stage  of  excitement,  marked  hj 
great  physical  activity,  loQnsKuty  and  imaj^inative  power;   is  of  short] 
duration i   longest  in  opinni  habitues,  a!>sent  with  large  doses;  (2)  aJ 
period  of  sopor,  in  which  there  are  diminished  sensibility,  weariness,  1 
contracted  pupils,  pale  face,  livid  lips,  drowsiness,  increasing  tode^p) 
sleepi  from  which,  however,  the  patient  may  l^e  roused,  and  whea  so 
roused  is  coherent  in  speech.     This  stage  merges  insensibly  into  the 
third,  that  of  coma.     The  patient  can  no  longer  be  aroused,  even  by 
violent  means.     The  face  is  pale»  the  lips  cyanosed,  the  muscular 
system  completely  relaxed,  the   reflexes  abolished,  the  pupils  con- 
tracted greatly,  and  insensible  to  light,  the  pulse  slow,   irregalar, 
compressible,    and   finally    imperceptible,   the   respiration  more  and 
more  infrequent,  stertorous,  shallow,   and  accompanied  by   mucous  i 
rales.     Retention  of  urine  begins  early  in  the  poisoning*     The  usual ' 
duration  of   a  fatal   poisoning  is   from    six   to   twenty -four  hoars. 
Deaths  have  occurred  in  forty-five  minutes  and  in  three  days. 

The  minimum  lethal  dose  for  a  non- habituated  adult  is  pi-obablfl 
3  to  4  grains.  Young  children  are  \ery  susceptible.  Tolerance  to  aj 
i-emarkable  degree  is  established  by  habit,  both  in  children  and  ia] 
adults,  and  instaoces  are  reported  in  which  i>0  to  6U  grains  have  becaj 
taken  daily,  without  toxic  effects,  by  moiT>hin- takers. 

The  treatment  should  consist  in  washing  out  the  stomach  with  a 
dilute  solution  of  potassium  permanganate,  leaving  about  500cc.  in 
the  stomach,  and  in  maintaining  the  respiration.  In  the  first  or  sec- 
ond stage  the  ** ambulatory  treatment'*  should  be  adopted  to  preveDt,| 
if  possible,  the  establishment  of  the  third  stage.  If  this  stage  developi^ 
the  main  reliance  is  to  be  placed  in  maintaining  the  respiration  bfl 
artificial  methods,  until  the  poison  has  been  eliminated.  Strong  coffee, 
or  cafifeTn,  by  the  mouth  or  rectum  are  of  benefit.  The  same  cannot 
be  said  of  atropin.    The  urine  should  be  drawn  by  the  catheter. 

The  opiates    leave  no   post-mortem   lesions,  except  such  as  ar 
usually  observed  after  death  from  asphyxia,  i.e.,  congestion  of  the 
vessels  of  the  brain  and  meninges,  and  of  the  lungs,  and  a  dark,  fluid 
condition  of  the  blood. 

Afkahids  of  unknown   con.siiiufitjji. — Of  the  numerous   alkaloidijfl 
whose  constitution  is  insufficiently  known  to  permit  of  their  classifl- 
cation,  only  a  few  can  be  here  briefly  considered: 

Alkaloids  of  the  Aconites.— Tlie  diff'erent  species  of  AconifHm 
cuutaiu  probably  a  number  of  alkaloids,  but  our  knowledge  of  them 
is  as  yet  extremely  iinperftff*t.  Plie  substances  described  as  ticfynitiiu 
Ujcockmiu^  napellin  arc  impure.  It  appears,  however,  that  the  prin- 
cipal alkahuds  of  AconiUfm  naptllm  and  of  A,  ferox,  although  differ-: 


Ln 

"I 

lOt 

[irtfl 
th«f 


ALKALOIDS 


56D 


ing  from  each  other,  are  both  compounds  formed  by  the  union  of 
acooin,  C^oHiiNOn,  with  the  radical  of  benzoic  acid  in  the  former^ 
and  with  that  of  veratric  aeid  in  the  latter. 

Aconitin  —  Acetylbenzoyl-aconin  —  CMH39(CH-j.CO)(CttIi.>.CO) 
XOji  ^  the  principal  alkaloid  of  A.  napeUns,  is  a  erystalline  solid, 
almost  insohible  in  water,  and  very  bitter.  It  is  decomposed  by  II2O 
at  140*^  (284°  P J  and  by  KHO  into  acouin  and  acetic  and  benzoic 
acids.     It  is  very  poisouons, 

Pscudo-aconitin — C:ieH49NOi2— occnrs  hi  A.  ffrox.  It  is  a  ciys- 
taU^ne  sotid,  having  a  burning  taste,  and  is  extrenaely  poisonous.  On 
decomposition  by  H2O  at  140*^  (284*^  P.)  it  yields  aconin  and  veratric 
acid. 

Japaconitin— CflflHg8N202i — has  been  obtained  from  the  root  of  A. 
japanicum^  and  is  a  crystalline  solid  which  is  decomposed  by  alkalies 
into  benzoic  acid  and  japaconin,  C2!eH4iNOio. 

The  color  reactions  described  as  characteristic  of  •^aconitine" 
are  not  due  to  the  alkaloid. 

Toxicology. — Aconite  and  "aconitine'^  have  been  the  agents  used 
in  quite  a  number  of  honiicidai  poisonings. 

The  symptoms  usually  manifest  themselves  within  a  few  iniuntcs; 

^  sometimes  are  delayed  for  an  hour.  There  is  numbness  and  tingling^ 
'4rst  of  the  month  and  fauces,  later  becoming  generaL  There  is  a 
sense  of  dryness  and  of  constrictiiHi  in  the  throat.  Persistent  vum- 
itiug  usually  occurs,  but  is  absent  in  some  eases.  There  is  dimin- 
ished sensibility,  with  numbness,  great  muscular  feebleness,  giddi* 
uess,  loss  of  speech,  irregularity-  and  failure  of  the  heart's  action. 
Death  may  result  from  shock  if  a  large  dose  of  the  alkaloid  be  taken, 
but  more  usually  it  is  by  syncope. 

The  treatment  should  be  directed  to  the  removal  of  unabsorbed 
poison  by  the  stonuich-punip,  and  w^ashing  out  of  the  stomach  with 
iafusiou  of  tea  liolding  powdered  charcoal  in  suspension.  Stimulants 
hould  be  freely  administered. 

Alkaloids    from    other    Sources.  —  Ergotin  —  C50H52N2O3 —  and 

Eobolin    are   two   brown,    amorphous,   faintly   bitter,   and   alkaline 

r^Ikaloids  obtained  fnnn  ergot.     They  are  nuidily  soluble  in  water  and 

^c>rin  amorphous  salts.     The  medicinal  prepurations  known  as  ergotin 


not  the  pure  alkaloid. 

Colchicin  — CiTHiuNOji^- occurs  in  all  portions  of  Colckicum 
^^fumnale  and  other  members  of  the  same  genus.  It  is  a  yellowish- 
^bite,  gummy,  amorphous  substance,  having  a  faintly  aromatic  odor 
•^Ocl  a  persistently  bitter  taste.  It  is  slowly  but  completely  sol u bit*  in 
^ater,  forming  faintly  acid  solutions.  It  forms  salts  which  are,  how- 
ever, very  unstable. 

Concentrated   IINOa^   or»   preferably,   a  mixture  of   H2SO4,  and 


570 


MANUAL    OP    CHEMISTHY 


1 


NaNOsi  colors  colehiciu  blue-violet.    If  the  solution  be  theu  diluH 
with   H"iO,  it  becomes  yellow,  and  on   addition   of  NaHO   solutiour 
briek  -  red . 

Veratrtn ^Veratrina,  U,  S.— C32H52N2O8  —  occurs    in    Vernirnm 
officinalis  ^^Amgrcpa  offirinnfis,  acconipaiiied  by  Sabadillin  —  OjoHa 
N2O5 — Jervin^ — C30H46N2O3 — find  other  alkaloids.     The  .substance 
which  the  name  Veratrina»  U.  S.,  applies  is  not  the  pnre  alkaloid 
but  a  mixture  of  those  occurring  in  the  plant* 

Concentrated  H2SO4  dissolves  veratrin,  formingr  a  yellow  solution, 
tumiug  orange  in  a  few  moments,  and  then,  in  about  half  an  bon»\ 
bright  carmine -red.      Concentrated  HCl  forms  a  colorless  solution^ 
with  veratrin,  which  turns  dark-red  when  cautiouijly  heated.  ^M 

Physostigmin  — Eserin  — Ciali-iiNsOa  —  is  an  alkaloid  existing  in 
the  Calabar  bean,  Phfisostigmn  teneftosHm.  It  is  a  colorless,  amor- 
pbouB  solid,  odorless  and  tasteless,  alkaline  and  difficultly  soluble  iu 
water.  It  neutralizes  acids  completely,  with  formation  of  iastelea 
salts.  Its  salicylate — Physostigminse  salicylas,  U.  S. —  forms  shor 
colorless,  prismatic  crystals,  sparingly  soluble  iu  water. 

Concentrated   IT2SO4  forms  a  yellow  solution  with   physostigml 
or  its  salts,  which  soon  turns  olive -green.    Coueentratcd  HXO3  fovmi 
with  it  a  yellow  solution.     If  a  solution  of  the  alkaloid  iu  H2SO4  ^e 
neutralized  with  NH+HO,  and  the  mixture  warmed,  it  is  gradnallj- 
colored  red,  reddish -yellow,  green,  and  blue.  ^ 

Emetin  —  C2SH40N3O5 — an  alkaloid  existing  in  ipecacttanha  which 
crystallizes  iu  colorless  needles  or  tabular  crystals,  slightly  bitter  aud^ 
acrid;  odorless,  and  sparingly  soluble  in  water. 

It  dissolves  in  concentrated  H28O4,  forming  a  green  solutionj 
which  gradually  changes  to  yellow.  With  Prohde's  i-eagent  it  giv€s\ 
a  red  color,  which  soon  changes  to  yetlowish-gi'een  and  then  to  green. 


m 

] 

be 

L'll 


PTOMAINS,    LEUCOMAINS  AND   TOXINS. 

The  name  ptomtnu,  derived  from  frriL^  (^Hhat  which  has  fallen* 
i.e.,  a  corpse),   was  first  suggested  by  Selmi  in  1878  to  apply  to  a 
substance,  or  class  of  substances,  first  distinctly  recognized,  although 
not  isokted,  by  liiiu,  which  are  produced  by  saprophytic  bacteria frtjw 
proteins  during  putrefaetifni.     The  ptonuuns  are  sometimes  referrto 
to  as  '^animal  alkaloids/^  a  term  which   is  misleading,  as  they  B^ 
produced  from  vegetable  as  well  as  from  animal  proteins,  and  but  f^^ 
of  them  are  alkaloids  in  the  present  acceptation  of  the  term  (p.  545) 
The  great  majority,  and  those  the  best  known,  are  monamins,  dianiio^' 
guanidins,  hydramins,  betains,  or  amido  acids.    The  term  "ptomaine 
does  not  therefore  apply  to  the  members  of  a  distinct  class  of  chen 


FTOMAINS,    LEUCOMAINS    AND    TOXINS 


571 


L'ompoi!  ids,  but  to  the  ba<.^terial  origin  of  substaiirc\s  belonging  to 
several  distinct  chemical  classes  aud  also  obtainable  by  otber  iiiethods, 
having  iu  common  otily  the  two  qualities  that  they  are  basic  and  con- 
tain nitrogen.  But  soine  ptomains  are  true  alkaloids.  Some  of  the 
superior  honiologues  of  pyridiu  (p.  518)  are  putrid  products,  A  base 
OgHiiN,  isomeric  with  coUidin,  formed  during  putrefaction  of  jelly- 
fish, on  oxidation  yields  nicotinic  acid»  CnH4N(C00II) »  whieh  is  also 
similarly  produced  from  nicoliu  (p.  551),  and  also  forms  a  chloro- 
platinate  and  an  iodomethylate  which  have  the  characteristic  proper- 
ties of  the  like  compounds  produced  from  the  pyridin  bases  (p.  517) 
and  vegetable  alkaloids.  Other  basic  substances  obtained  from  brmvn 
cod -liver  oil,  and  probably  formed  by  a  modified  putrefaction,  are 
hydropyridiu  derivatives  (p.  519).  Among  these  are  a  dihydrohitidin, 
CiHiiN,  a  dihydrocollidin,  CgHi^N,  and  a  complex  hydropyiidic 
oxyacid,  called  morrhuie  acid,  HO^C^Hr.N.CaHfl.COOH.  Indole  and 
skatole,  products  of  putrefaction,  also  come  within  the  deliuition  of 
alkaloids. 

Owing  to  the  wide  variations  iu  the  r-heniieal  constitution  of  the 
ptomains,  they  possess  no  characters  by  which  they  can  be  distin- 
guished as  a  class.  Some  are  strongly  alkaline  and  busic»  others  only 
feebly  so.  Some  are  liquid,  oily  and  volatile,  others  fixed  and  crystal- 
line. Some  are  very  prone  to  oxidation,  and  are  active  reducing 
agents*  others  are  quite  stable.  For  the  same  reason,  no  analytical 
method  is  possible  by  which  vegetable  alkaloids  and  ptomaliis  cnii  be 
separated  from  each  other  en  nmsse,  nor  are  any  r*^JU?tious  known  to 
which  all  ptoroains  respond  while  vegetable  alkaloids  do  not,  or  the 
reverse;  nor  are  such  reactions  to  be  expected.  Certain  classes  of 
ptomains  may  be  identified  or  separated  from  vegetable  alkaloids,  but 
not  alK  Thus  thnse  which  are  diamins  may  be  separated  by  forma- 
tion of  their  benzoyl  derivatives  {p.  385),  but  only  a  few  ptomains 
are  diamins.  Those  ptomains  which  are  reducing  agents  give  a  blue 
color  with  a  mixture  of  ferric  chlorid  and  potassium  ferricyanid  but  all 
ptomams  do  not  reduce,  and  some  vegetable  alkaloids,  sneb  as  morphin 
and  veratrin,  do.  It  was  feared  that  the  existence  of  ptomains,  whose 
formation  begins  shortly  after  death,  and  also  occurs  during  life, 
might  render  the  detection  of  vegetable  poisons  in  the  cadaver  impos- 
sible. Such  fears  were  by  no  means  gronndless,  as  there  is  abundant 
evidence  that  ptomains  have  been  mistaken  for  vegetable  alkaloids  in 
cheraico -legal  analyses.  It  is,  however,  possible  to  positively  and  cer- 
tainly predicate  the  existence  or  non-existence  in  a  cadaver  of  a  given 
vegetable  alkaloid,  provided  it  have  a  sufficient  immber  of  character- 
izing reactions,  but  it  can  only  be  done  after  a  thorough  and  con- 
scientious examinati<m  by  all  physiological  and  chemical  reactions. 

The  name  leucomatn  is  applied  to  basic  nitrogenous  substances. 


572 


MANUAL    OF    CHEMISTKY 


I 


I 


such  as  the  pnrin  and  pyrimidiu  bases,  which  are  produced  in  living: 
vertebrate   organisms.     But,   as    sonje    leiieouiiims,    sueh    as  cholin^ 
tyrosiUj  aud  betaitij  are  also  ptomaius,  being  produced  by  saprophytic , 
bacteria,  the  Hue  of  distinction  cannot  be  sharply  drawn. 

Toxins. — The  name  'Hoxin  *^  was  first  used  by  Briegeti  and  bj'  himl 
applied  to  poisonous  ptomains  and  other  toxic,  basic,  nitrogenous 
substances,  obtained  from  the  culture  media  of  pathogenic  bacteria  or 
from  animal  organisms.     Such  are  the  four  basic  substances  obtained^ 
from  the  eu[ture  media  of  the  tetanus  bacillus:   Tetanin»  UiaHuNiOi,  | 
a  yellow,  strongly  alkaline  syrup;   Tctanotoxin,  C5H11X  ( ? ),  a  volatile 
oil;    Spasmotoxin  and  another  unnamed  base  of  undetermined  com-  ^ 
positioQ,   all  of  which   fonn   deliquescent   hydroehlurids,    and    very^ 
soluble,  crystalline  platioochlorids.     These  bases,  when  injected  into 
animals,  cause  clonic  or  tonic  convulsions  of  great  intensity,  termi- 
nating in  death.     But  it  has  been  shown  that  the  cultures  from  which 
these  basic  substances  are  obtainable,  after  filtration  through  porcelain^ 
are  vastly  more  toxic  than  the  combined  bases.     These  therefore  can 
only  constitute  a  small  fraction  of  the  active  material  produced  by  the 
bacilli,  and  the  more  virulent,  nou*i)asic  product  is  a  toxin  in  the 
more  modern  sense. 

In  this  latter  sense  the  toxins  are  poisouous  substances  of  unknown  * 
chemical  composition  produced  by  bacteria  or  other  cells.  They  are 
uot  products  of  decomposition  of  the  proteins,  as  are  the  ptomains, 
but  synthetic  products,  secretions,  as  it  were,  of  the  bacteria.  They 
are  not  all  members  of  the  same  chemical  class.  Some,  the  extracel- 
lular toxins,  so  called  because  they  pass  in  great  part  into  the  culture 
media,  have  many  resemblances  to  the  albnmoses  (p.  612).  They  are 
nou -crystalline,  soluble  in  water,  and  diulysable,  are  precipitated  by 
alcohol  and  by  ammonium  sulfate,  and  lose  their  virulence  wheufl 
heated.  The  toxins  of  diphtheria  and  tetanns  lieloug  to  this  class. 
But  little  is  known  of  the  properties  of  the  intracellular  toxins,  wbii^h 
are  largely  retained  in  the  bacterial  cells  until  these  are  destroyed, 
except  that  they  do  not  dialyse,  and  are  more  resistant  to  hent  thai 
the  extracellular  toxins.  The  toxins  of  typhoid,  tubercle  and  glauder 
belong  to  this  sccood  class. 

The  toxalbuniins  are  substances  obtained  from  certain  seeds  01 
secreted  by  animals,  which  are  highly  toxic,  and  have  the  genera^ 
properties  of  albumoses  or  of  globulins.  They  therefore  differ  froii 
the  toxins  solely  in  that  they  are  not  of  bacterial  origin,  and,  further*  — 
more,  they  resemble  bacterial  poisons  more  closely  than  vegetable 
alkaloids  in  their  actions,  particularly  iu  the  latent  period  precedrti  ^ 
the  manifestatiou  of  their  effects.  _ 

The  best  studied  of  the  vegetable  toxalbuniins   is  ricin,  whrcJ 
exists  io  the  castor -oil  bean  {Rkinns  rommnnh) ,  being  contained  \n\ 


?d.fl 
an^ 

3 


PTOMAINS,    LEUCOMaInS    AND    TOXINS  573 

the  press-cake,  but  not  in  the  oil.  It  is  extracted  by  10  per  cent 
NaCl  solution,  from  which  it  is  salted  out  by  saturation  with  MgS04. 
It  is  neutral  in  reaction,  is  precipitated  by  alcohol,  gives  the  biuret 
reaction,  and  is  destroyed  by  heat.  Its  lethal  dose  for  rabbits  is  0.04 
mgm.  per  kilo.  Other  toxalbumins  are:  abrin,  from  jequirity  {Abrus 
precatorius) ;  crotin,  from  the  seeds  of  Croion  iiglium;  phallin,  from 
various  toadstools  {Amanita) ,  and  the  toxic  constituents  of  the  venoms 
of  serpents  and  of  the  poisonous  secretions  of  spiders  and  insects. 


574 


MANUAL    OF    CHEMISTRy 


PHYSIOLOGICAL   CHEMISTRY. 


The  adjentive  '^physiolugicar'  is  here  used  in  its  proper  sense. 
Physiology  (<^t;t7toXti7o?=disuoiirsing  of  uature)  is  defioed  as  "the  sum 
of  scientific  knowledge  concerning  the  functions  of  living  things," 
Chemistry  has  been  defined  as -^hat  branch  of  science  which  treats 
of  the  composition  of  substances »  their  changes  in  composition,  and 
the  laws  governing  such  changes."  Therefore  physiological  ehem- 
istry  has  to  do  with  the  composition  and  changes  in  composition  of 
living  things,  whether  they  be  in  a  normal  or  in  an  abnormal  condition. 
The  medical  tendency  to  distinguish  between  ■'  physiological  '*  and 
"  pathological "  chemistry,  the  former  being  considered  as  a  branch  of 
physiology »  and  the  latter  as  a  division  of  pathology,  besides  in- 
%^olving  a  solecism,  is  nndesirable  for  four  reasons  ;  (1)  The  methods 
by  which  tissues  and  fiuids  are  obtained  from  otherwise  normal  ani- 
mal bodies  for  investigation  are  frequently  such  that  they  establish  a 
pathological  condition,  and  the  extent  to  which  the  material  so 
obtained  is  thus  modified  from  the  norraal  must  always  be  taken  into 
consideration  in  interpreting  the  results.  {2)  A  solution  of  a  doubt- 
ful question  in  normal  physiological  chemistry  is  frequently  obtained 
by  establishing  a  pathological  condition,  or  by  taking  advantage  of 
one  occurring  as  a  result  of  disease  or  accident,  and  comparing  the 
composition  of  a  tissue  or  fluid  under  these  conditions  with  those 
from  a  normal  subject.  (3)  Pathological  chemical  composition  and 
processes  are  variations,  either  qualitative  or  quantitative,  from  the 
normal,  and  can  therefore  only  be  studied  by  comparison  with  the 
normal,  hence  the  study  of  "physiological"  and  '* pathological'* 
chemistry  must  go  hand  in  hand.  (4)  The  substances  most  nearly 
concerned  in  the  functions  of  life  are  of  the  most  complex  chemical 
constitution,  and  their  study  requires  a  high  degree  of  chemical 
kuowledge^  patience  and  ingenuity,  The  phytriulogical  cheniist  mutit 
be  a  thoroughly  trained  chemist,  equipped  with  sufficient  medical 
knowledge  for  the  study  of  this  chemical  specialty,  not  a  physiologist 
or  a  pathologist  who  dabbles  in  chemistry. 

Vegetable  physiological  chemistry  is  particularly  of  interest  to  the 
agriculturist,  animal  physiological  chemistry  to  the  veterinarian  and 
the  physician.     Only  the  latter  branch  will  be  here  considered. 

The  subject  maybe  divided  into  two  sections:    (1)   the  study  of' 
the   properties,   physical   and    chemical,   of   the   various    substances 
(proximate  principles)  which  occur  in  living  bodies;    (2)  that  of  the 
chemical   changes,   chemical   processes,  which   take   place  in  living 
organisms,  which  ubviuusly  involves  l«c  consideration  of  the  couiposi* 


PROTEINS 


575 


tion,  and  the  variations  tberein  io  health  and  disease  of  animal  tissues 
and  fluids.  The  first  division  is  a  part  of  pure  chemistry,  and  has  been 
considered  in  the  preceding:  pages,  except  in  so  far  as  it  relates  to  the 
albuminous  substances,  or  proteins,  which  being  still  of  undetermined 
constitution  find  no  certain  place  in  the  classification  of  organic  com- 
pounds,  and,  on  the  other  hand,  being  intimately  associated  with  the 
chemical  processes  of  life,  may  be  suitably  considered  here. 

PROTEINS. 


Representatives  of  this  class  of  substances  are  never  absent  from 
living  animal  or  vegetable  cells,  to  whose  "life"  they  are  indispensable. 
They  are  for  the  most  part  uncrystallrzable,  although  the  hfenioglobins 
crystallize  readily,  as  do  certain  vegetable  proteins,  and  the  true  albu- 
mins may  be  obtained  in  crystals.  8ome  are  soluble  in  pure  water, 
others  only  in  the  presence  of  other  substances,  and  others  are 
insoluble  in  water.  They  are  insoluble  in  alcohol,  ether,  chloroform 
or  benzene.  With  the  exceptions  of  the  peptones  and  some  albumoses, 
they  dialyse  only  very  slightly,  or  not  at  all;  they  are  typical  '* colloids" 
(p,  18).  They  retain  foreign  substances,  such  as  coloring  matters^ 
mineral  salts,  etc,  with  great  tenaey,  whether  in  their  solutions  or 
when  separated  therefroni,  and  have  not,  therefore,  been  obtained 
"aah-free."  They  are  lasvogyrous*  except  the  nucleoproteids,  which 
are  dextrogyrous.  They  are  composed  of  carbon,  hydrogen,  oxygen 
and  nitrogen.  Most  of  them  also  contain  sulfur,  and  sc^me  contain 
phosphorus;  others,  iron,  copper,  or  iodin.  Their  molecular  weights 
are  very  large,  probably  greater  tijan  10,000.  Their  constitution  is 
unknown,  and  no  substance  has  as  yet  been  obtained  synthetically 
which  is  identical  with  a  natural  protein,  although  substances  have 
been  thus  produced  having  many  of  the  properties  of  gelatins  or 
albumoses.  The  native  albumins  are  neutral  and  non -ionized  in  their 
solutions,  but  they  may  become  ionized,  and  behave  both  as  bases  and 
acids,  in  the  presence  of  other  ions, 

CoaguIation.^ — All  native  albumins  are  separated  as  solids  or 
semisolids  when  their  very  faintly  acid  solutions,  containing  minute 
quantities  of  salts,  are  heated.  This  separation  is  called  coagulation, 
and  the  coagulated  albumin  is  said  to  be  denaturizcd,  because  it  has 
been  so  changed  that  it  cannot  be  again  brought  into  its  original  form 
of  solution.  Certain  proteins,  such  as  the  histons  (p,  587),  may  be 
eoagnlated  by  heat  without  being  denaturizcd,  i,e,,  they  may  be  redis- 
solved  in  their  own  form.  Albumins  may  also  be  denaturized  without 
being  coagulated.  This  occurs  when  heat  is  applied  to  their  alkaline 
or  strongly  acid  solutions  j  when  alkali-  or  acid -albuminates  are  formed, 
which,  although  denaturized  from  the  parent  albumin,  remain  in  solu- 


576 


MANITAL    OF    CHEMISTRY 


tioii.  With  faintly  acid  reaction  the  eortg^latioii  is  complete.  The 
temperature  at  which  coagulation  takes  place  varies  with  different 
albumins,  but  is  fairly  constant  for  each  individual  protein,  and  is^^ 
referred  to  as  its  coagulation  temperature,  which  is  one  of  the  faetor^H 
for  its  identification.  The  coagulation  temperature  is,  however, 
affected  by  the  amount  of  salts  present,  the  most  favorable  concentra- 
tion being  about  1  per  cent  of  sodium  ehJoridi  and  to  a  greater  extent 
by  the  presence  of  certain  nitrogenous  com  pounds »  such  as  cholin, 
pyridin,  anilin  and  nrea.  Solid  albumins,  unaltered  and  soluble  in 
their  original  form,  may  be  obtained  by  evaporation  of  their  solutions 
^t  temperatures  below  their  coagulation  temperatures. 

Denaturization  and  coagrnlation  are  also  caused  by  agencies  other 
than  heat:  by  long  agitation  or  even  prolonged  standing  of  solntious 
of  the  albumius;  by  agitation  of  such  solntious  with  ether  or  chloro- 
form; by  tlie  mineral  acids,  particularly  nitric  acid;  by  certnin 
metallic  salts,  snch  as  HgCla,  PbCC^HaO-)-,  OnSOi,  PenClfi,  or  K+Fe- 
(CN)fl,  the  last  in  the  presence  of  acetic  aeid;  by  "alkaloid  reagents,*^ 
snch  as  tannin,  phosphotuugstic  and  phosphomolybdic  acids,  tungst^tes 
potassium  iod-hydrarg>Tate,  or  iodobismuthate  in  acid  solution;  bj 
ebloral,  picric  aeid,  salicylsulfonic  acid,  trichloracetic  aeid,  and  phenol^ 
Formic  aldehyde  produces  denaturization  without  coagulation  if  tb0 
reaction  be  acid  or  alkaline. 

Certain  native  albunains,  snch  as  fibrinogen,  myosin,  and  gluten- 
casein,  are  also  converted  into  denatnrized  products,  not  returnable  to 
the  original  form,  by  contact  with  porous  substances,  or  by  the  action  — 
of  enzymes.  ■ 

Precipitation. — 'When  alcohol  is  added  to  an  albuminous  solution 
the  albumin  is  precipitated,  without  immediately  suffering  other 
change,  and  may  be  redissolved  in  its  primitive  form.  But  by  pro- 
longed contact  with  alcohol  it  suffers  denaturization  and  coagulation. 

Native  albumins  and  albnnioses  are  precipitated  unchanged  froni 
their  solutions  by  the  addition  thereto  of  certain  neutral  salts,  either  in 
the  solid  form  or  in  saturated  solution.     Tbis  method  of  precipitation 
(which  is  also  resorted  to  in  the  soap  industry)  is  known  as  salting^ 
out.    Ammonium  sulfate  and  zinc  sulfate  are  the  most  efficient  agents 
for  this  purpose,  and  precipitate  all  native  albumins  and  albumoses 
completely,  while  sodium  ehlorid,  sodium  sulfate,  magnesium  sulfate, 
etc.,  precipitate  only  certain  classes  of  proteins.     The  quantity  of   a 
given  salt,  i.  e. » the  concentration  of  the  salt  solution,  which  is  require^ 
to  precipitate  the  several  proteins  is  quite  constant  for  each  specie 
but  varies  with  different  species.    The  more  complex  the  protein  (aD<J 
therefore  the  greater  its  molecular  weight),  the  more  readily  it  is  salted 
out.     Thus  fibrinogen  may  be  completely  precipitated  by  half  saturfl* 
tion  in  neutral  solution  with  the  less  active  sodium  ehlorid,  while  Ji 


p^H) 


denteroalbiimose  requires  complete  saturation  with  the  more  active 
ammonium  sulfate  in  acid  solution  for  eornplete  precipitation.  An 
acid  read  ion  favors  salting  out  to  such  an  extent  that  the  differentia- 
tions referred  to  below  are  only  observed  in  iieutra]  solutions.  Each 
species  of  albumin  or  aibumose  requires  the  addition  of  a  certain  pro- 
portion of  salt  to  its  solution  before  precipitation  begins,  and  for  each 
there  is  definite  coneentration  at  whieh  precipitation  is  complete,  and 
beyond  which,  of  course,  increase  of  concentration  produces  no  effect. 
These  upper  and  lower  limits  are  constant  for  any  givcTi  species,  the 
lower  somewhat  less  so  than  the  upper,  and  are  utiliised  for  the  identi- 
ficatioQ  and  separation  of  the  several  species.  For  the  determination 
of  these  limits  varying:  graduated  qnautities  of  a  neutral,  cold  saturated 
gohition  of  the  salt  are  added  to  samples  of  fixed  volume  (2  cc.)  of 
the  protein,  the  mixtures  diluted  to  tixed  volutne  (10  cc),  agitated» 
^d  allowed  to  stand  for  a  half  hour.  The  lower  limit  is  hctweeu  the 
ncentration  of  the  most  dilute  sample  in  whieh  turl>idity  is  produced 
and  the  one  next  below  which  remains  clear.  The  turbid  samples  are 
then  filtered,  and  the  filtrates  treated  with  a  small  additional  quantity 
(0.1  ee.)  of  the  salt  solution.  The  upper  limit  is  between  the  con* 
centration  of  the  most  concentrated  filtrate  in  which  this  addition 
causes  turbidity,  and  that  next  above  which  remains  clear.  Both 
limits  are  more  closely  determined  by  further  experiment  within  the 
limits  thus  ascertained.  Thus  the  upper  and  lower  limits  of  fibrinogen 
with  ammonium  sulfate  are  1.6  and  2.6  respectively,  and  those  of 
irnm  albumin  are  6.4  and  9.0,  whieh  means  that  in  a  solution  of 
serum  albumin,  water  and  saturated  salt  solution,  in  10  cc.  of  which 
there  are  contained  6.4  ce.  of  saturated  salt  solution,  pif?cipitation 
V»egins;  and  in  one  containing  9  ec.  of  saturated  salt  solution  in  10  cc, 
precipitation  is  complete.  The  limits  are  also  expressed  in  percentages 
-of  Baturated  salt  solution ;  thus  64  per  cent  and  90  per  cent  for  serum 
albumin. 

Although  the  proteins  pn?cipitated  by  salting  out  are  not  denatur- 
d,  and  may  be  redissolvcd  unchanged  from  their  primitive  form, 
liejr  tenaciously  retain  a  portion  of  the  salt,  which  cannot  be  separated 
ydial^^sis;  and  in  some  cases  they  retain  the  anion  in  a  form  of  eoni- 
iuation  from  whieh  the  acid  cannot   be  removed   by  water.     Thus 
rum  albumin  fornis  a  sulfate  with  the  anion  of  ammonium  sulfate. 
Color  Reactions. — The  color  reactions  of   the   proteins  are   not 
liar  to  them,  but  depend  upon  the  existence  in  them  of  certain 
pmie  groupings  which  also  occur  in  other  substances.    While,  Ihere- 
they  do  not  serve  for  the  identification  of  the  proteins  unless 
en  collectively,  they  are  of  notable  interest  as  indicating  the  exist- 
in  those  protein  molecules  which  respond  to  a  given  reaction,  of 
grouping  which  that  reaction  characterizes. 

37 


578 


MANUAL    OF    CHEMISTRY 


XanihoproUic  Reaeihn^ — If  a  solid  protein  be  moistened  with  con- 
(•eutrated  IINO:i,  a  yellow  eolur  is  ])rodiiced  whieli,  on  addition  of 
NH4HO,  chan^^es  to  orange,  oi%  ou  additiou  of  NallO,  to  reddish* 
browu.  With  solutions  of  native  albumins  a  white  coagalum  is  pro 
dueed  in  the  eold,  which  later  heoomes  yellow.  This  reaetion  depeu( 
upon  the  presence  of  the  tyrosin  grouping,  or  that  of  indole, 

MUlon^s  Reaviion, — A  purple -red  color  when  a  solid  protein 
warmed'  with  Milton's  reagent  to  about  70^.  With  sohitions  of  proteini 
a  white  coagnlum  is  formed  io  the  eold,  whieh  assumes  the  red  color 
when  warmed.  The  reagent  is  made  by  dissolving,  by  the  aid  of  heat» 
1  pt.  of  Hg  in  3  pts.  of  HNOa,  sp.gr. 1.42,  dihitiug  with  2  vols.  H2O, 
and  decanting  after  24  hours  It  contains  mereurous  and  nien'urie  ni- 
trates and  some  nitrons  acid.  This  reaction  is  usually  ascribed  to  the 
presence  of  a  single  phenolic  hydroxyL  But  the  color  given  by  phenoi 
cresol,  salicylic  acid,  etc,  is  a  red-orange,  rather  than  the  purple 
of  the  proteius,  and  the  two  uaphthols  give  a  yellow  color,  withou 
any  tinge  of  red.  It  is  also  said  that  the  introduction  of  a  second  0 
changes  the  color  to  yellow,  but  the  color  with  hydrnquiuoue  is  not 
be  distinguished  from  that  with  phenol,  Tyrosin,  which  contains  hot 
phenol  and  amido  groups,  reacts  frankly  with  Millon's  reagent,  and 
the  similar  reaction  of  the  proteins  is  probably  due  to  presence 
them  of  the  tyrosin  grouping. 

The  Bittref  Efftdimt. — A  violet  or  red  color  with  an  excess  of  KflO 
or  NaHO  and  a  few  drops  of  a  2  per  cent  solution  of  CuSOi  and  heat* 
With  the  native  albumins  the  color  is  blne-viulet  or  i-ed* violet,  au* 
-with  the  albnnioses,  peptones  and  higher  polypeptids  distinctly  red 
The  reaction  is  given  by  compounds  containing  two  CO.NIIa  groups 
or  one  such  group  and  one  CII^NHa  group  (p.  407),  and  sceias  to 
depeud  upon  the  existence  of  the  polypeptid  groups  (p.  415)  in  the 
protein  molecule.  This  is  the  only  one  of  the  color  reactions  to 
which  the  simplest  of  the  proteins  respond. 

Adamkiewiez  Reaction, — If  glyoxylic  acid  (obtained  in  solution  t>I 
reducing  a  solution  of  oxalic  acid  by  sodium  amalgam)  be  added  to  • 
solution  of  a  protein,  the  solution  floated  upon  the  surface  of  conce^"^* 
trated  H2SO4,  and  the  mixture  heated,  a  ring  of  color  is  produced  ^ 
the  junction  of  the  layers,  red,  green »  then  violet,  and  the  whcrJ® 
liquid  becomes  violet  when  the  layers  are  mixed.  The  reactic^^ 
depends  upon  the  presence  of  the  tryptophane  group  (p,  540),  and  ^ 
not  given  by  gelatin. 

Liehermann's  Reactimi. — The  protein,  freed  from  fat  byextracticF 
with  ether  and  hot  alcohol,  is  dissolved  by  boiling  in  eoucentrat 
HCl  to  which  a  drop  of  concentrated  H2SO4  has  been  added,  forming 
a  deep  violet-blne  solution.     This   is  probably  also  a  tr}T>tophan^ 
reaction. 


•o- 

I 


^^^^^^^^^^^^r  PROTEINS  ^^^r  57a 

^^^   MoHsh's  Reaciion  (p*  323}  is  giveu  by  proteins  coutaiDing  a  car- 

I  bob^'drate  gruop. 

I  Decompositions. — Tlie  study  of  the  decomposition  products  of  the 
prott*ins  by  oxidizing  aguuts,  by  fusion  with  mineral  alkaHes,  by  boil- 
ing with  dihite  aeids  or  alkalies,  by  the  aetion  of  proteolytic  eiizymeSt 

■  by  those  of  other  hydrolysing  agencies^  and  by  other  meaii:s,  is  of  great 

■  mtei*est«  being  tlie  means  by  whieh  knowledge  of  the  tioustitutioD  of 
these  complex  molecules  must  be  sought  for.  By  the  action  of  the 
le^s  energetic  of  these  decomposing  agents  compounds  are  obtained 
which  are  of  more  complex  structure  than  those  produced  by  more 
active  agencies,  although  the  simpler  produets  of  decomposition  may 
also  accompany  thoHe  of  higher  molecular  weight,  as  by-products  of 
less  complete  decompositious,  The  more  complex  products  represent 
in  their  '* radicals  "  certain  "  gi*onpings/'  or  "atomic  complexes,"  which, 
we  have  every  reason  to  believe,  constitute  integral  parts  of  the  pro- 
tein moleenlar  structure,  as  the  esters  are  constituted  of  the  "atomic 
complexes"  of  the  acid  and  alcohol. 

Active  oxidizing  agents  attack  the  protein  molecule  profoundly, 
yielding  pn)ducts  which  are  for  the  most  part  far  removed  from  the 

I  original  substance,  and  which  are  themselves  products  of  decora  posi- 
tion of  the  'Vatomic  complexes"  above  referred  to;  acids  and  aldehydes 
of  the  fatty,  oxalic  and  benzoic  series  and  their  uitrils,  including 
hydrocyanic  acid,  ketones,  amido  acids,  carbon  dioxid,  and  amraonia. 

fWith  HXO3  various  nitro  derivatives  are  ol>taiued,  and  with  CI,  Br 
and  I  halid  derivatives.  By  oxidation  with  K^Mu^Oh  an  acid,  oxyproto- 
sulfonic,  containing  the  sulfonic  group,  is  formed,  and  by  continued 

^ oxidation  peroxypro tonic  acid*    In  oxidation  with  BaMu20«  guanidin 
l«  one  of  the  products. 

Fusion  with  caustic  alkalies  also  causes  deep  decomposition,  the 
products  being  ammonia,  mercaptan,  fatty  acids,  amido  fatty  acids, 
ty rosin,  indole  and  skatole. 

By  boiling  with   dilute  mineral  acids,  or  with   HCl+SnCla,   the 

Proteins  are  hydrolysed  with  formation  of  hydrogen  sulfid,  ethyl  sulfid 

«tici   ammonia  as  simple   products,   and   amido   acids,   hexon   bases 

(r>.  417),  pyrrolidin  and  oxypyrollidin  carboxylic  acids  (p.  511),  and 

^'^olanoidins,  the  last  named  being  also  products  of  decomposition  of 

^h^  melanins,  substances  to  which  the  hair  and  other  dark  portions  of 

^lie  body  owe  their  color.     The  amido  acids,  including  serin,  ty rosin 

and  eystin,  produced   in  this  and  other  hydrolytie   decompositions 

P^^bably  exist  in  the  proteins  as  poly  pep  t  ids,  formed  by  the  union  of 

1,     *ev^ral  amido  acid  complexes  (p*  415). 

m         Considering  the  nitrogen  which  is  split  off,  in  more  or  less  complex 

*    combination,  on  hydrolysis  of  proteins  by  boiling  with  dilute  acids,  it 

Ippears  to  have  existed  in  the  parent  protein  in  five  forms  of  combi- 


580 


MANUAL    OF    CHEMISTRY 


iiatioD,  eorrespondiaff  to  five  classes  of  decompositiou  products:  (ll 
Easily  separable,  so*ealled  atQuio* nitrogen,  given  off  as  XHj;  (2) 
Urea  forming  nitrogen,  in  the  guanidin  remainder  of  argioin  (p.  418) ; 
(3)  Basic  nitrogen,  or  diamido  nitrogen,  contained  in  basic  iiiti'ogeu 
Goinpoands,  precipitable  by  phosphotungstic  acid;  (4)  Monaniido 
nitrogen,  in  monaniido  acids;  (5)  Hnmiis  nitrogen,  in  humus -like 
melanoidins,  dark -colored,  aniorphons^  nitrogenous  remainders,        ^^ 

The  quantitative  distribution  of  nitrogen  in  these  five  groups  dif^^ 
fers  in  different  proteins:    (1)   is  entirely  absent  in  protamins;   1-2 
per  cent  in  gelatin;   5-10  per  cent  in  other  animal  proteins;    13-20 
per  cent  in  vegetable  proteins.     (2)  In  protamins  22-44  per  cent; 
histons  12-13  per  cent;   in  gelatin  8  per  cent;   in  other  proteins  2- 
per  cent.     (3)   In  protamins  63-88  per  cent;    in   histons    35-42 
cent;    in  other  animal  proteins  15-25  per  cent;    in  vegetable  prote 
5-37  per  cent.     (4)  The  greater  part  of  the  nitrogen,  55-76  per  ceut^ 
in  proteins  other  than  protamins  is  in  this  form.     (5)  Varies  within 
wide  limits. 

The  sulfur,  the  amount  of  which  varies  greatly  in  different  protein4^| 
is  given  off  on  hydrolysis  as  cystin,  cystem,  a-thiolactic  acid,  nier- 
captaus  and  ethyl  sulfid. 

The  nitrogen -contaiuing  products  of  hydrolysis  of  proteins  may  Iw 
thus  classified: 

I.  Aliphatic.     A.  Containing  no  sulfur: 

(1)  Guanidin  remainder.  H2N,C:NH^(+ornithin=argiDin) ; 

(2)  Monobasic  nionamido  acids:    glycocoU,  alanin,  amido-valer-. 
iauic  acid,  leucin,  serin; 

(3)  Dibasic  monaniido  acids:   aspartic  and  ghitamic; 

(4)  Monobasic  diamido  acids:   ornithin,  lysin; 
B.  Containing  nitrogen  and  sulfur;   Cystin,  cystein; 
TI.  Carboeyclic;    phenylaraidopropionic  acid»  tyrosin; 
IIL  Heterocyclic:   A.  Pyrrole  derivatives:  pyrrolidin  and  oxypyr-     ^ 

rolidiu  carl >oxy lie  acids; 

B,  Glyoxalin  derivatives  (?):    liistidin; 

C.  Indole  derivatives:   indole,  skatole,  tryptophane.  __ 
AH  proteins  except  the  protamins  and  some  of  the  peptonea  eontain 

sulfur.    One  fraction  of  this,  referred  to  as  ^Moosely  combined-'  sulfur -:»- 
is  given  off  as  hydrogen  sulfid  by  boiling  with  alkaline  solntions.    LXT 
is  this  fraction  which  causes  the  formation  of  a  brown  or  black  color*^^ 
or  even  a  black  precipitate,  when  a  protein  is  heated  with  a  solutio^cz: 
of  caustic  alkali  in  presence  of  lead  acetate,  in  the  ^'sulfur  test^fc 
the  proteins.     The  second  fraction  is  not  separable  in  this  manu^" 
but  only,  as  a  sulfate,  by  fusion  with  saltpetre  and  sodinm  carbonat* 
or,  as  a  snlfid,  by  fusion  with  caustic  potash.     The  ratio  of  loo?f*l^ 
combined  sulfur  to  total  sulfur  varies  notably  in  different  proteins 


valer- 
typyr-^ 


PROTEINS 


581 


;  from  %  in  sertun  albumin  to  f  in  hEeino^lobio.  It  wonld  appear  from 
this  eonstaut  difference  in  separability  of  different  portions  of  snlfur 
from  proteins  that  the  molecules  of  these  substances  rnnst  contain  at 
least  two  atoms  of  snlfur  in  different  forms  of  combination.  This 
coDclnsion,  is,  however,  invalidated  by  the  fact  that  both  cystin  and 
cystein  only  give  off  one- half  of  their  sulfur,  and  that  very  slowly »  by 
boiling  with  alkaline  solutions,  yet  the  two  atoms  of  sulfur  in  cystin 
are  symmetrically  combined,  and  the  molecule  of  cystem  contains  but 
one  sulfur  atom. 

Many  proteins,  not  only  the  glyeoproteids  {p.  594),  but  also  true 
albumins,  as  egg  albumin,  serum  albumin,  serum  globulin,  the 
nucleoproteids,  etc.,  react  with  MoHsch's  reagent  (p.  323),  and,  on 
hydrolysis,  split  off  a  carbohydrate  group,  which  is  an  amido -sugar » 
usually  glucosamin,  0HO.CHNH2.(CHOH)a.CH:iOH  (p.  387),  prob- 
ably existing  in  the  protein  as  a  polysaccharid  complex.  Some  of  the 
nucleoproteids  yield  a  pentose  group,  others  hi?vuliuie  acid.  Other 
proteins,  as  casein,  myosin,  and  fibrinogen  yield  no  carbohydrate. 

The  decomposition  of  proteins  by  the  proteolytic  enzymes,  pepsin, 
trypsin  and  papain,  consists  of  a  series  of  hydrolyses  and  results,  first 
in  the  formation  of  albnmoses  and  peptones,  and  later,  by  trypsin 
particularly,  of  polypeptids,  amido  acids,  hexon  bases,  tryptophane, 
amins,  diarains  and  ammonia.  These  changes  occur  in  the  processes 
of  digestion,  and  will  be  discussed  later. 

Putrefaction  is  the  decomposition  of  dead  protein  material  under 
the  influence  of  certain  baeteria,  attended  by  the  evolution  of  more  or 
less  fetid  products.  In  order  that  it  may  occur,  certain  conditions  are 
necessary:  (1)  The  preseuce  of  living  bacteria,  or  of  their  germs; 
(2)  the  presence  of  moisture;  (B)  a  temperature  between  5"^  and  90°; 
(4)  an  atmospheric  condition  suitable  to  the  growth  of  the  bacteria. 
Some  of  the  several  species  of  bacteria  which  cause  putrefaction  are 
flBrobic,  i.  e.,  they  require  the  presence  of  air  for  their  development, 
while  others  are  anaerobic,  i.  e.,  they  thrive  best  in  the  absence  of 
oxygen.  The  first  products  of  putrefaction  are  the  same  as  those 
produced  by  proteolytic  enzymes:  albumoses  and  peptones.  The  later 
pi^ducts  vary  with  the  conditions  under  which  putrefaction  occurs. 
The  most  prominent  are:  (1)  Inorganic  products  sueh  as  N,  H,  H2S,- 
NHa,  and  simple  organic  compounds  such  as  CO2  and  hydrocarbons; 
(2)  acids  of  the  fatty,  oxalic  and  lactic  series;  (3)  amido  acids,  such 
as  a-amidovaleriauic  acid  and  leucin;  (4)  aliphatic  monamins,  as 
trimethylamin;  diamius,  as  pntresciu,  from  arginiu,  and  cadaverin, 
from  lysin;  and  hydramins,  as  eholio,  muscarin  and  neuriu;  (5) 
aromatic  products,  among  which  are:  (n)  tyrosin  and  its  derived  prod- 
nets,  phenol,  eresol,  p-oxyphenylacetic  acid,  and  p-oxyphenylpropi- 
onto  acid;  (b)  indole,  skatole,  skatole-carboxylic  acid,  and  skatoleacetie 


582  MANUAL    OF    CHEMISTRY 

acid,  derived  from  the  tryptophane  complex;  (c)  phenylamidopropionic 
acid  and  its  derivatives,  phenylethylamin,  phenylacetic  acid,  and 
phenylpropionic  acid;  {d)  ptomains  of  undetermined  constitution, 
belonging  to  the  aromatic  series;  pyridin  derivatives.  Under  certain 
imperfectly  defined  conditions  buried  protein  material  does  not  undergo 
ordinary  putrefaction,  but  is  converted  into  a  substance  resembling 
tallow,  and  called  adipocere,  which  consists  chiefly  of  ammonium 
palmitate,  stearate  and  oleate,  calcium  phosphate  and  carbonate,  and 
an  undetermined  nitrogenous  substance. 

Classification  of  Proteins. — A  chemical  classification  of  proteins, 
based  upon  their  constitution,  is  at  present  manifestly  impossible, 
and  any  other  classification  can  be  only  tentative,  and  probably  tem- 
porary. For  a  provisional  classification  some  of  the  proteins  arrange 
themselves  naturally  in  fairly  well-defined  groups,  according  to  their 
products  of  decomposition  and  their  solubilities,  while  others,  of  quite 
diverse  characters,  must  be  still  arranged  in  the  miscellaneous  group 
of  the  "albuminoids."  Probably  the  Hammarsten-Cohnheim  classifi- 
cation is  the  most  satisfactory  for  the  present: 

A.  True,  or  Native  Albumins : 

a.  Albumins — soluble  in  pure  water;  coagulated  by  heat.  Serum 
albumin,  ovialbumin,  lactalbumin. 

6.  Olobulins — insoluble  in  pure  water,  soluble  in  dilute  solutions 
of  neutral  salts;  coagulated  by  heat.     Serum  globulins,  oviglobnlins, 
lactoglobulin,  cell  globulins,  vegetable  globulins. 
.       c.  Coagulating  Albumins — yielding   coagulated   products    by   the 
action  of  enzymes.     Fibrinogen,  myogen,  myosin,  glutenprotein. 

d.  Nucleoalbumins — almost  insoluble  in  pure  water,  or  in  solutions 
of  neutral  salts,  easily  soluble  in  slight  excess  of  alkalies;  contain 
phosphorus;  on  peptic  digestion  yield  pseudonucleins.  Casein,  vitel- 
lins,  phytovitellins,  mucin -like  nucleoalbumins. 

e.  Histons — contain  35-42  per  cent  of  their  nitrogen  as  basic 
nitrogen. 

d.  Protamins — contain  63-88  per  cent  of  their  nitrogen  as  basic 
nitrogen. 

The  histons  and  protamins  do  not  exist  as  such  in  nature,  but  are 
most  conveniently  classified  in  this  group. 

B.  Derived  Albumins: 

a.  Albuminates — insoluble  in  water  or  in  salt  solution,  except  in 
presence  of  acid  or  alkali;  derived  from  native  albumins  by  the  action 
of  acids  or  alkalies.     Acid -albuminates,  alkali -albuminates. 

b.  Albumoses — Propeptones — soluble  in  dilute  salt  solutions,  pre- 
cipitated by  cold  HNO3,  redissolved  on  heating. 


NATIVE    ALBUMINS 


583 


e.  Peptones — very  soluble  iu  wuttn%  readily  dialysable,  give  Done 
of  the  protein  reactions  except  the  biuret  reaetion. 

d.  Coagukiied  alhumins—wi^ohMe  iu  water  and  in  salt  solutions; 
obtained  from  native  albumins  by  tlie  action  of  beat,  of  strong  mineral 
acids,  or  of  enzymes,  and  do  not  regenerate  the  parent  protein.  Coag- 
alated  albumins  and  globulins  and  ibriu. 

C.  Proteids, 

a.  H(€moglobinb — decomposable  into  an  albumin  and  a  crj'stalline 
pigment  or  chromogen. 

b,  Nuchoproteids — yield  nucleic  acids  and  native  albumins  on 
decomposition,     Nncleobiston,  etc, 

f.  Ohjcoprofeids — dtHjoniposable  into  a  reducing  substance  and  a 
native  albumin.     Mucin,  mucoids,  phosphoglycoproteids. 

D.  AlbuminoidS'^prot.eins  not  included  in  one  of  the  above  classes. 
Keratins,  collagen,  elastin,  spongiu,  fibroin,  amyloid^  albumoid,  reti- 
culin,  ichtliylepidin,  etc, 

NATIVE   ALBUMINS. 


Albumins — are  soluble  in  water,  in  dilute  salt  solutions,  and  in 
dilute  acids  and  alkalies.  They  are  coagulated  by  heat,  by  eKcess  of 
mineral  acids,  and  by  certain  metallic  salts.  They  are  salted  out  by 
NaCl  and  MgSO*  only  in  acid  solution,  but  are  precipitated  by  (NH4)3- 
8O4  in  neutral  solution,  in  wbich  the  limits  are  6.4  and  9.0  (p,  577). 
They  are  capable  of  crystaltizaiion.  On  hydrolysis  they  yield  6,34- 
8.53  per  cent  of  their  nitrogen  a.s  ammonia,  67. 8  per  cent  as  monamido 
nitrogen,  and  21.3  per  cent  as  diamido  nitrogen.  They  yield  1.5-2.0 
per  cent  of  tyrosin,  and  0.29-2.53  per  cent  of  cystin,  and  contain 
a  larger  proportion  of  sulfur,  1.6-2.2  per  cent,  than  other 
prot^eins  except  the  keratins.  (See  Scrum  a(bumin  under  Blood, 
Urine;   Lactalbumin,  under  Milk,  and  Ovialbumin  (p.  584). 

Globulins^are  insoluble  iu  pure  water;  soluble  in  dilute  salt 
solutions,  and  in  very  dilute  acids  or  alkalies.  They  are  preeipitated 
from  these  solutions  by  dilution  with  a  large  quantity  of  water,  by 
dialysis  (See  Serum  globulin,  p.  652),  by  dilute  mineral  acids  and  by 
acetic  acid,  or  by  CO2.  An  excess  of  COz,  however,  redissolves  the 
precipitate.  Tliey  are  completely  salted  out  by  saturation  with  MgHO*; 
only  partly  by  saturation  with  NaCL  Their  limits  with  (NH4)2S04 
are  2,9  and  4.6.  The  precipitates  obtained  by  salting,  soluble  at  first, 
[become  coagulated  and  insoluble  ou  standing.  They  arc  coagulated 
by  heat.  They  have  not  been  crystallized.  On  hydrolysis  they  yield 
8,9  per  cent  of  their  nitrogen  as  ammonia,  68.3  per  cent  as  monamido 
nitrogen,  and  24.9  per  cent  as  diamido  oitrogen.     They  yield  3  per 


584 


MANUAL    OF    CHEMISTRY 


cent  of  tyrosin,  and  1.5  per  cent  of  cystin,  and  contain  less  sulfur 
tban  do  the  albumins,  0.97  per  cent  {See  Blood,  Uriue»  Milk)*  ^m 

White  of  Egg* — The  "white  "  or  '*albuioen  *^  of  hetis*  eggs  cousists^l 
of  a  yellowish  fluid,  eneloaed  in  a  delieate  network  of  connective  tis- 
sue  (keratin).  The  fluid  portion,  separated  by  beating  and  ftltration 
thronuh  muslin,  is  alkaline,  sp.gr.  1.045,  and  coagulates  to  a  dense, 
opaque,  white  mass  when  heated.  But  if  the  egg^s  have  been  soaked  in 
a  solution  of  eaustie  alkali  for  three  days,  the  "white"  remains  trans- 
parent when  heated.  This  is  due  to  the  formation  of  an  alkalialbumin, 
which  is  also  obtained  without  alkaline  treatment  from  the  eggs  ot^M 
nesting  birds,  and  is  called  "tata- albumen,"  Egg  albumen  contains ^^ 
80OSS0  p/m  of  water,  and  120-200  of  solids,  which  latter  contain 
100-130  proteins,  3-7  salts,  and  traces  of  fat,  lecithins,  cholesterol, 
and  a  carbohydrate.  The  proteins  of  w^hite  of  egg  are  at  least  live  in 
number:  67  per  cent  of  the  100-130  above  referred  to  consist  of  two 
oviglobulinsi  coagulated  at  57.5°  and  67*^,  partly  precrpitable  by 
dilution  with  water,  and  completely  by  salting  with  MgS04.  There 
are  three  ovialbumins,  diifering  in  coagulation  temperatures:  C>T°,..^| 
72°,  and  82°;  and  in  specific  rotary  power:  [a]D=  —25.8°,  — 34.2**,^^ 
and  — 42.5°,  all  of  which  are  lower  than  the  value  of  [ajn  tor  serum 
albumin,  -^62.6°  to  — 64.6°.  These  ovialbumins  also  differ  from  serum 
albumin  in  that  they  appear  in  the  urine  w^hen  injected  into  the  circu- 
lation, which  serum  albumin  does  not  do  in  health,  Ovialburain  may 
be  caused  to  crystallize  in  needles  by  removal  of  globulins  from  per- 
fectly fresh  egg  albumen  by  partial  salting  with  (Nn4)2S04,  slow 
evaporation  of  the  solution  at  the  ordinary  temperature,  and  recrystal- 
lizatiou.  The  carbohydrate  al.iove  referred  to  appears  to  exist  in  the 
form  of  a  glyeoproteid,  containing  15  per  cent  of  t^arliohydrate,  and 
I.IB  per  cent  of  sulfur.  Ovomucoid  is  a  pseodopeptone,  constituting 
about  10  per  cent  of  the  proteins  of  white  of  egg.  It  is  not  preeipi* 
tated  by  mineral  acids,  except  phosphotungstic  acid,  and  is  obtained, 
after  removal  of  the  albumins  and  globulins  by  heat  and  acetic  acid^ 
by  precipitation  with  alcohol. 

The  classes  of  vegetable  albumins  and  vegetable  globulins  ar 
not  sharply  differentia  ted »  as  the  latter  are  not  entirely  insoluble  it 
pure  w^ater.     Both  are  coagulated  by  heat.     The  effect  of  NaCl  npoi 
solutions  of  vegetable  globulins  also  varies  with  the  proportion  of  s« 
added;   a  small  amount  causing  a  precipitate,  which  redis.solves  in 
larger  proportion,  and  is  again  precipitated  by  a  further  additioa    ^«z>i 
salt.    Wheat  flour  contains  0.26  to  0,30  percent  of  protein  coagnliktfc'Je 
by  heat,  and  1.55  to  1.90  per  cent  of  protein  Timtfrial  not  so  coa^«3- 
lable.     Conglutin,  a  protein   obtained    from    the    lupines    and   fro ^3? 
almonds,  has  most  nearly  the  character  of  the  globulins,  being  solut>/^ 
in  salt  solutions  of  5  to  10  per  cent,  and  precipitable  therefrom   ^J 


NATIVE    ALBUMINS 

dilatioE   with  water.    A  similar   globuliu   accorapaaies   legumin  ia 
peas. 

Coagulating  Albymtns — exist  in  nature  in  solution,  and  change  to 
a  coagulated  product  "spontaneously,"  i.  e.,  by  a  process  the  nature 
of  whicb  is  imperfectly  understood,  but  which  is  usually  attributed  to 
enzyme  action.  Certainly  coagulation  of  these  substances  occurs  by  a 
different  process  from  that  which  brings  about  the  coagulation  of 
albumins  and  globulins  by  heat,  mineral  acids,  etc. 

The  most  important  member  of  this  group  is  fibrinogen,  the  pre- 
curser  of  fibrin,  which  will  be  considered  under  '* Blood'*  (p.  651)* 

When  muscular  tissue,  freed  from  blood,  and  immediately  after 
death,  is  expressed,  a  liquid  is  obtained  which  is  called  the  nnuscle- 
plasma,  and  the  remaining  solid  is  the  moscle-stroma.  The  liquid, 
on  standing,  separates  into  a  coagulutn  of  myogen-fibrin  and  myosin- 
fibrin,  and  a  liquid,  the  muscle-serum.  While  the  nmscle- plasma  is 
neutral  or  faintly  alkaline,  the  muscle -senim  is  arid  in  reaction. 
Myogen-fibrin  is  formed  by  coagulation  of  a  protein,  myogen,  existing 
in  solution  in  the  plasma.  The  formation  of  muscle  -  fibrin  is  com  par* 
able  with  the  formation  of  fibri?i  from  fibrinogen  in  coagulation  of 
the  blood,  and,  corresponding  to  the  fibrinoglobnlin  produced  from 
fibrinogen,  but  in  larger  amount,  a  portion  of  the  myogen  fibrin 
remains  in  the  senim  as  soluble  myogen-fibrin. 

Myogen  is  obtained  from  muscle -plasma,  after  removal  of  myosin 

(below)  by  addition  of  (NH^)■J80|  to  28  per  cent  and  filtration*  by 

further  addition  of  (NHiJ^SO^  to  near  saturation.     The  precipitated 

^soluble  myogen-fibrin  is  then  removed,  after  washing  with  saturated 

CNH4)2S04  solution,  by  resolutiou  in  water,  and  coagulation  at  40'^ 

Cfttid  filtration. 

Myogen  is  soluble  in  water,  from  which  it  is  completely  precipitated 
l:>y  saturation  with  (NH.s);!K04,  and  partly  by  NaCl  or  MgSOi*  It  is 
civilly  partly  precipitated  by  alcohol,  and  not  by  dialysis.  Acetic  acid 
«md  mineral  acids  convert  it  into  acid-albnminate,  and  it  is  only 
^zi^xecipitated  by  CO*j  in  presence  of  neutral  salts.  It  is  therefore  more 
c*losely  allied  to  the  albumins  than  to  the  globulins.  It  coagulates  at 
t*.fcout  60*^.  Soluble  inyogL-u- fibrin  is  precipitated  by  dialysis,  coagu- 
l«».te8  at  40°,  and  is  gradually-  converted  into  the  insoluble  form  in 
f>x^sence  of  neutral  salts,  Myogen  constitntea  about  80  per  cent  of 
t^lxe  proteids  of  rausele- plasma. 

Myosin,   the  second    protein  of   rausele -plasma,   constitutes  the 

'■^^wuaining  20  per  cent  of   its  total  proteins,  and  is  precipitated   by 

p^^rtial  saturation  with   (XH|)2^04  to  28  per  cent.     It  is  not  soluble 

*^^    pure  water,  but  soluble  in  dilnte  salt  solutions,  from  wlricli  it  is 

I^**^^ci  pita  ted  by  dilution  with  water,  by  dialysis,  and  by  CO3,  in  wliich 

^^spects  it  resembles  the  globulins.     It  is  almost  completely  precij)- 


586 


MANUAL    OF    CHEMISTRY 


itated  by  alcohol,  and  by  dilute  acids  or  alkalies.  Greater  quantities 
of  acid  or  alkali  eouvurt  it  into  allmmiiiafces.  It  begins  to  coagulate 
at  35^  aud  does  so  completely  at  50'^,  When  coagulated  it  coustitutes 
myosin -fibririp  Whether  or  no  the  foruiaUon  of  muscle  fibrins  has  a 
causative  relation  to  the  phenoujenoii  of  post-mortem  rigidity  is 
uncertain.  Myosin -like  proteins,  having  the  same  coagulation  tem- 
perature as  nmscle  myosin,  have  also  been  obtained  from  other  tissues, 
spleen,  thymus,  leucocytes,  etc. 

Gluten-protein  is  a  precursor  of  gluten,  existing  in  wheat  and 
other  grains,  which  has  the  characters  of  a  globulin,  and  is  supposed 
to  form  gluten  hy  enzyme  action. 

Nucleoalbumins,  also  called  phosphoglobulins,  from  their  phos- 
phorus content  and  their  rest*inblaiicc  Ut  the  globnlins,  include  casein 
(see  Milk,  p.  763),  ovivitclliu,  ichthulin  and  phytovitellins.  They 
contain  phosphorus,  0.43  per  cent  in  ichthulin,  0,85  per  cent  in  casein, 
and  5.19  per  cent  in  ovivitcllin,  and  also  traces  of  iron.  They  behave 
as  acids,  are  almost  insoluble  in  water,  soluble  in  very  weak  alkaline 
solutions,  very  sparingly  soluble  iti  dilute  salt  solutions,  and  are  not 
coagulated  by  heat.  On  peptic  digestion  they  yield  para-  or  pseudo- 
nucleins  as  amorphous,  sparingly  soluble  residues,  which  contain  the 
major  part,  if  not  the  whole  of  the  phosphorus.  They  resemble  the 
nueleoproteids  and  the  glycoproteids,  but  differ  from  the  former  in  that 
they  yield  no  xanthin  bases  on  decomposition,  and  from  the  latter  in 
that  they  yield  no  reducing  substance  under  like  conditions* 

The  yolk  of  hens'  eggs  contains  572-515  p/m  of  water,  and  485-428 
p/m  of  solids.  The  latter  consist  of  213-228  p/m  of  fats,  156-158  of 
proteins,  84-107  of  lecithins,  4-17  of  cholesterin,  and  33  of  salts, 
besides  cerebri n  and  a  coloring  matter,  a  lutein.  In  the  asb  the  K 
salts  exceed  the  Na  salts;  the  Ca  salts  are  present  in  notably  large 
amount,  12-13  per  cent  of  the  ash;  and  the  amount  of  phosphoric 
acid  is  also  large,  64-67  per  cent.  The  principal  protein  is  ovivitellin, 
a  nucleoalbnmin,  whose  pseudonnclein  is  avivitellic  acid,  which  con- 
tains 9.88  percent  of  phosphorus  and  0.57  percent  of  iron  in  organic 
combination;  yields  small  quantities  of  arginin  and  histidin  on  decom- 
position, and  gives  the  Millon  and  biuret  reactions.  Ovivitellin  has 
not  been  obtained  free  from  lecithins,  which  may  indicate  that  the 
two  substances  exist  in  chemical  combination,  as  a  Iecithalbumin» 
although  this  is  uncertain. 

The  eggs  of  fish  (carp)  contain  a  nucleoalbnmin,  called  ichthulin, 
which  on  decoraposition  by  alkalies  yields  a  pseudonnclein,  ichthtilinic 
acid,  which  contains  10.34  per  cent  of  phosphorus,  but  no  iron.  In 
a  crystalline  form  it  constitntes  the  yolk -platelets. 

The  phytovitellins,  or  phytoglobulins,  occurring  in  the  vegetable 
world,  are  related  both  to  the  globulins  and  to  the  caseins.    Thev  are 


NATn'E    ALBUMINS 


587 


ijiii  character,  being  preci  pi  tilted  by  acids,  altliougli  soluble  in 
fXfSess;  aod  soluble  ia  dilute  alkalies,  from  which  sol ut ions  they  are 
precipitated  by  dilution  with  water,  atid  by  dialysis.  In  dilute  sohititJii 
they  coagulate  at  75°,  but  in  concentrated  solution  only  iu  part,  or  ;-r 
a  more  elevated  temperature.  In  dilute  solution  they  are  coagulated 
by  HNO3,  but  the  coagulum  redii^solves  in  excess  or  on  heating.  They 
give  the  protein  color- reactions,  including  a  red  color  with  the  biuret 
reaction.  They  form  crystals  quite  readily.  That  from  Para  nuts 
crystallizes  in  oetahedra,  containing  Ca  and  Mg,  and  is  one  of  tlie 
constituents  of  the  aleurone  corpuscles^  which  are  granules  having 
the  appearance  of  those  of  starch,  but  giving  a  brown  color  with  iodin, 
which  occur  in  Para  and  other  nuts.  Legumin  occurs  in  peas,  bean?, 
etc.  It  contains  0.35  per  cent  of  phosphorus;  on  i>cptic  digestion  it 
yields  a  psendonnclem  containing  1.83  per  cent  of  phosplHU'us;  and  it 
forms  a  solution  in  water  which  gelatinizes  when  heated.  Edestin 
is  a  crystalline  phytovitellin  obtained  from  various  seeds,  notably 
those  of  hemp.  Gluten  is  a  protein  material  existing  in  wheat,  whieli 
remains  insoIuVde  and  forms  a  soft,  bnt  tough,  elastic  paste  when  the 
flour  is  kneaded  in  a  stream  of  water  on  a  fine  sieve.  It  constitutes  78 
per  cent  of  the  total  proteids  of  wheat.  It  is  made  up  of  at  least  four 
coraponeuts.  The  most  abundant  of  these,  gluten-caseitit  or  glutenin, 
is  a  phytovitellin  which  remains  as  an  insoluble  residue  on  extraction 
of  gluten  with  alcohol.  The  others,  gliadin,  mucedin,  and  gluten- 
fibrin,  differ  principally  in  their  solubility  in  water  and  iu  alcohol  of 
different  degrees  of  concentration.  Maize  contains  a  protein,  called 
zein,  which  resembles  gluten -fibrin,  but  is  not  identical  with  it.  It 
is  insoluble  in  water,  but  soluble  in  alcohol,  and  in  dilute  alkaline 
solutions. 

Histons— are  obtained  by  decomposition  of  hapmoglobins  and  of 
nucleoproteids,  or  as  addition  products  by  union  of  protamins  with 
albumins.  They  are  therefore  intermediate  between  the  protamins  and 
the  other  proteins,  and  closely  related  to  the  former.  Neither  histons 
nor  protamins  are  "native  albumins"  in  the  sense  that  they  exist  in 
nature  in  their  own  form,  but  they  are  well -characterized  proteins, 
which  form  conjponent  parts  ot  more  complex  protein  molecules  which 
exist  in  nature.  The  histons  are  distinguished  from  other  proteins 
chiefly  by  two  properties  dependent  upon  each  other:  their  large  con- 
tent of  hexon  bases,  and  the  basic  character  of  the  entire  molecule. 

The  histons  are  soluble  in  water,  from  which  they  are  precipitated 
by  a  small  quantity  of  ammonia,  the  precipitates  being  soluble  in  excess, 
except  arnmoniacal  salts  be  present,  when  they  persist.  Some  histons 
do  not  conform  entirely  to  the  above  (p.  588).  They  are  readily  sol- 
able  in  acids.  They  are  not  coagulated  by  heat  in  pure  aqueous  solu- 
tinn,  but  in  presence  of  salts  they  are  coagulated »  but  not  denaturized^ 


588 


MANUAL    OP    CHEMISTRY 


as  the  coagulum  is  soluble  in  acida,  not  as  iieid- albuminate,  but  as 
histoQ.  They  are  preeipitatt;d  by  HNOa,  but  resemble  the  albumoses 
rathtf  thau  the  albumins  in  that  the  precipitate  is  redissolved  on 
heating.  They  contain  sulfur,  but  no  phosphorus.  They  give  the 
xanthoproteic  and  biuret  reaetions,  but  not  the  Millou.  They  contain 
no  carbohydrate  component.     They  have  not  been  crystallized. 

They  resemble  the  protamins  in  that  with  solutions  of  albumins 
they  form  precipitates  which  are  soluble  in  acids  or  alkalies;  iu  that 
they  form  precipitates  with  phosphotungstic  acid  and  other  alkaJoid 
rengents  in  solutions  of  neutral  or  faiutiy  aikaliue  reaction,  while  the 
true  native  albumins  only  do  so  in  acid  liquids;  and  in  their  strongly- 
basic  character  and  high  nitrogen  content,  a  large  proportion  of  which, 
as  much  as  40  per  cent»  separates  as  basic  nitrogen  on  hydrolysis. 
Both  histous  and  protaraius  have  pronounced  toxic  action,  causing 
first  acceleration  and  then  arrest  of  respiration,  and  marked  diminu- 
tion of  bh>od  pressure. 

The  described  histous  are:  Globin»  the  "albumin  component"  of 
hfemoglobin  {see  Blood,  p.  660) ,  Histon  occurs  in  its  nucleic  acid 
salt  as  the  nucleohiston  (p.  591)  of  the  leucocytes  ol  the  thymus,  and 
other  glands,  from  which  it  is  split  by  hydrolysing  with  BaH202  or 
dilute  HCL  It  is  strongly  basic^  readily  combines  with  acids,  and  is 
precipitated  from  its  salts  by  amniouiai  iu  an  excess  of  which  it  is  not 
soluble.  Parahiston^  also  in  the  form  of  a  nucleate,  accompanies 
histon,  the  salts  of  the  two  bases  apparently  existing  in  combination, 
as  they  are  in  definite  proportion  iu  the  uuclein  derived  from  nucleo- 
histon; Salmon  is  a  histon  from  the  spermatozoa  of  the  salmon; 
Scombron,  one  from  those  of  the  mackerel,  whose  precipitate  by 
ammonia  is  not  redissolved  by  excess;  and  Arbacion,  one  from  th© 
testicles  of  the  sea-urchin,  which  is  only  iucompletely  precipitated  by 
ammouia. 

Protamins. — These  substances,  which  are  regarded  as  the  simplest 
of  the  proteins,  have  been  obtained  only  from  the  melt  (spermatozoa) 
of  fishes,  in  which  they  exist  combined  with  nucleic  acids  (p»  592). 
They  contain  no  sulfur,  but  much  nitrogen  and  little  carbon.  Their 
products  of  decomposition  are  much  fewer  in  number  than  those  of 
the  proteins  in  general,  yet  they  have  many  of  the  general  reactions 
and  properties  of  the  proteins.  They  are  alkaline,  basic,  nitrogenous 
substances,  which  can  be  salted  out  of  their  solutions  by  NaCl  or 
{NH4)2S04  with  more  or  less  facility.  They  give  the  biuret  reaction 
brilliantly,  but  not  the  Adamkiewicz,  and,  with  the  exception  of 
cyclop terin,  not  the  Millon  reaction.  They  form  salts  with  acids^ 
which  are  soluble  in  water ^  insoluble  in  alcohol  and  in  ether,  of  which 
the  sulfate,  pi  crate  and  platinochlorid  are  ntilized  for  their  extraction 
and  purification.     They  are   not   coagulated   by  heat.     Solutions  of 


4 


* 


c 


DERIVED    ALBUMINS 


589 


their  salts  are  precipitated  in  neutral  or  even  alkaline  soliitioiis  by 
phosphotmigstic,  toii£^8tic%  and  piin-ie  atnds,  and  by  <*brotimtes  and 
ferroeyanids.  Probably  tbeir  must  chnraeteristLc  rt'uetion  fs  tlie  forma- 
tion of  preeipitates  of  histones  (p.  387)  from  annnoniaral  solutions 
of  albumins  or  of  primary  albiimoses.  On  hydrolysis  by  bulling  dilute 
ncids^  or  by  tryptic  digestion  they  yield,  tirst  iH'ptune-like  substances, 
oalled  protones,  which  are  Iflevoijyrous,  and  give  the  biuret  renetiotj, 
but  do  not  form  histon  precipitates  with  albumins  in  mnmtmiaeal 
solution.  Later  more  simple  substance?^  are  obtained,  nmuny:  wliieli 
the  hexon  bases,  particularly  arginin,  predominate  greatly,  along  v ith 
vei-y  small  quantities  of  monainido  acids,  tryptophatieand  'A-j)yrrolidin 
<'arboxyiie  acid.  A  large  proportion  of  tlieir  total  nitmgen,  63-88 
percent,  is  basic.  The  described  protamins  are:  Salmin,  C'-Mdl^rNnOg, 
I  from  saltnou  rnelt^  and  Clupein,  from  the  melt  of  the  herring,  wei"© 
supposed  to  be  identical,  but,  as  they  form  different  nucleates  they  are 
distiuet  substances  (p.  591).  On  hydrulysis  they  yii'ld  82-84  per  cent 
of  arginiu,  with  a  little  aniidovaleriaiiit!  aei<l:  Scombrin,  IV^HviNirjOg, 
from  the  melt  of  the  nuiekerel;  Sturin,  (^aiHjiXiTOut  fi'om  the  melt  of 
the  sturgeon,  which  yields  all  three  hexon  bases,  13  per  eent  liistidii:. 
58  per  cent  arginin,  12  per  eent  lysin,  and  an  nndctiMinint'd  mcmntiiido 
acid;  Accipcnsedn,  Ca^'-.HTsNiKOar  related  to,  i>ut  not  identical  with 
fitunn,  from  another  speeies  of  sturgeon;  and  Cyclopterin  tVom  the 
melt  of  the  lump- fish,  which  yields  C3  per  e^^nt  of  arjjinin.  but  n^i 
lysin  or  histidin,  and  8  per  cent  of  tyrosin,  atid  gives  the  Millun  reae- 
tion.  Cyclopterin  also  differs  from  other  protamins  in  containing: 
sulfur. 

The  pmtamina  are  obtained  from  the  melt,  previously  washed  with 
alcohol -ether,  by  extraction  with  1-2  per  cent  H-iSOi,  pt'ecipitafeion 
with  aIe4>hol,  and  purification  by  repeated  solution  in  water  and 
precipitation  with  alcohol,  and  by  conversion  into  the  picrate  or 
platioochlorid. 

DERIVED   ALBUMINS. 


Albuminates. — Native  albumins  dissolve  in  very  dilute  acids  or 
alkalies  without  immediate  change,  but  with  more  concentrated  acids 
or  alkalies,  or  by  prolonged  contact  with  Uiore  dilute  solutions,  the 
native  albumins  behave  as  bases  and  acids,  beeonje  denaturized,  and 
form  acid-  or  alkali -albuniimites.  The  degree  of  concentration  of  acid 
required  to  produce  tlie  combination  is  greater  than  tliat  necessary  for 
alkalies,  but  a  mineral  acid  of  too  great  concentration  causes  coagula- 
tion. The  formation  of  alkali -albuminate  is  also  hitjdt^red  by  too 
^eat  eon  rent  rat  iun  of  the  alkali.  In  the  formation  of  tlie  albuminates 
the  protein  solution  is  converted  into  a  more  or  less  thick,  transparent 


590 


MANUAL    OF    CHEMISTRY 


all 


jelly  (Liederkiihn's  jelly),  wbase  formation  is  accelerated  by  heat. 
The  traospareut  '*tata*albnmen''  obtained  from  alkalized  hens*  eggs 
is  an  alkali-albnmiiiate  (p*  5B4).  Albuminates  are  soluble  iu  dilute 
aeids  or  alkalies,  but  insoluble  in  water  or  iu  solotiousof  neutral  salts. 
They  are  therefore  precipitated  from  their  solutions  by  neutralization. 
Their  solutions  are  not  coagulated  by  heat. 

The  formation  of  alka!i*albnmiimtes  is  attended  by  loss  of  nitrogen 
{as  KHa)*  and  of  sulfur  (as  II2S),  and  therefore,  while  aeid- albumi- 
nate may  be  converted  into  alkali -albuminate  by  addition  of  alkali, 
the  reverse  change  cannot  be  effected.     Aeid -albuminates  are  precip-^ 
ituted  by  very  small  quantities  of  neutral  salts,  the  quantity  of  salt" 
required  being  the  less,  the  smaller  the  amount  of  aeid  present.    Dur- 
ing the  gradual   neutralization  of  a  strongly  aeid  solution  of  acid- 
albuminate  a  precipitate  is  jilternately  formed  and  redissolved,  and 
finally  remains  permanent,  because  of  alternate  precipitation  by  th 
salt  produced   by  neutralization  of   the  aeid,  and  resolution   in   th© 
excess  of  aeid.     Alkali* albuminates  are  also  precipitated  by  neutral 
salts,  bat  it  requires  very  much  larger  quantities  of  the  salt  to  produce 
the  result  than  with  acid -albuminates.    The  fact  that  native  albumins  ™ 
are  only  coagulated  by  heat  iu  faintly  aeid  solutions  is  explainable^ 
upon  the  theory  that  the  already  den  atari  zed  aeid -albuminate  is  readily 
separated  by  the  small  quantity  of  salt  preseut,  while  the  alkali -albu- 
minate, although  denaturized,  remains  uucoagulated   in  presence  of 
mueii  larger  amouut  of  salts. 

The  formation  of  aeid* albuminates    is   much  accelerated   by  the 
presence  of  pepsin,  and  constitutes  the  first  step  in  the  process  o; 
gastric  protein  digestion,  which  process  also  rapidly  proceeds  further, 
with  formation  of  albumoses  and  peptones,  and  even  of  more  simple 
substances. 

A  form  of  acid -albuminate,  called  syntonin,  is  prod  need  from  the 
proteins  of  muscular  tissue  (p.  585)  by  the  action  of  RCl  of  2  pru  by 
prolonged  contact,  or  by  short  contact  of  the  same  acid  in  presenceA 
of  pepsin.  ^ 

Albumoses  and  Peptones  are  products  of  digestion,  aud  will  be 
considered  under  that  head. 

Coagulated  Albumins — are  produced  from  some  of  the  previously 
described  proteins,  either:  (1)  by  heat,  (2)  by  alcohol  in  presence  of 
neutral  salts.  If  the  contact  with  alcohol  be  of  short  duration  the 
protein  is  precipitated^  and  may  be  redissolved;  if  the  contact  be 
prolonged  it  is  coagidated  and  permanently  altered;  (3)  by  long 
agitation  of  their  solutions;  (4)  by  the  action  of  certain  enzymes,  h 
But  little  is  known  of  the  nature  of  the  change,  or  of  the  chemical  | 
characters  of  the  products.  These  are  white  substauces  (fibrin,  hard- 
boilod  white  of  egg)   insoluble  iu  water,  or  in  solutions  of  neutral 


t 

I 


PROTEIDS 


591 


I 


salts,  or  iu  dilnte  acids  or  itlkalifs  at  the  ordinary  teraperature. 
Tbey  are  Boluble  by  couverisioii  into  acid-  or  alkati -albumins  by 
corii!entrated  acids  or  alkalies,  or  by  the  same  when  dilute  if  aidtid 
by  beat.  They  are  acted  uprm  by  digestive  enzymes  and  converted 
iuto  albumoses  and  peptoneH.  Although  coagulated  album ius  are 
usually  artificial  products,  except  fibrin  naturally  coagfulated,  proteins 
having  similar  properties  are  met  with  in  the  liver  and  in  other 
glands. 

PROTEIDS. 

The  proteins  of  this  class  ai*e  conjugate  compounds,  consist iug  of 
a  native  albumin  united  with  some  other  well-defined  ^* prosit hetic" 
group  (prosthetic=added).  Thus»  besides  an  albumin,  the  ht^mo- 
globins  on  decomposition  yield  a  crystalline  pigment,  the  nncleopro- 
teids  a  nucleic  acid,  and  the  glyeoproteidi?  a  reducing  carbohydrate* 
Haemoglobins.— {see  Blood,  p.  659), 

Nucleoprotcids — are  compounds  intimately  connected  with  the 
processes  of  cell -life,  which  occur  principally  in  glandular  organs: 
liver,  pancreas,  thyuius,  kidneys,  adrenal  glands,  mammary  glands, 
etc.,  existing  chiefly  in  the  uell-nucleus,  but  also  in  the  protoplasin. 
They  are  distinctly  acid  in  function,  are  sohilrle  iu  water  and  in  dilute 
salt  solutions,  very  soluble  iu  alkalies,  from  which  solutions  they  may 
be  salted  out  by  neutral  salts.  Their  albumin  component  is  coagulated 
by  heat,  by  mineral  acids,  and  by  alkaloid  reagents*  Their  solutions 
are  dextrogyrous,  while  those  of  other  proteins  are  Itevogyrous,  the 
left  rotation  being  due  to  the  nucleic  acid  component.  They  give 
the  color  reactions  of  the  proteins. 

The  nncleoproteids  arc  decomposed  by  heating  with  dilute  acids^ 
or  by  peptic  digestion,  into  the  products  of  hydrolysis  of  an  albumin, 
and  a  ^*true  nnelein.**  By  continued  decomposition  the  nuclein  is 
decomposed  into  a  further  quantity  of  albumin  product  and  a  nucleic 
acid;  and  by  still  further  dectnnpositiou  the  nucleic  acid  is  split  into 
Xanthiu  and  uracil  bases,  a  phosphorus  acid  and  a  carbohydrate.  The 
nucleoprotcids  of  the  melt  of  fishes  are  more  simply  constituted  than 
those  from  mammalian  tissues,  and  do  not  yield  a  nuclein  as  an  inter- 
mediate product,  but  are  directly  split  into  a  protamin  or  histon  and 
a  nucleic  acid.  These  are,  therefore,  protamin  or  histon  nucleates. 
Balmin  nucleate  contains  18.81  per  cent  nitrogen,  and  7.55  per  cent 
phosphorus;  clupein  nucleate,  21.07  percent  nitrogen,  and  6.08  per 
at  phosphorus. 

The  best  known  of  the  nucleoprotcids  is  nucleohiston,  which  is 
obtained  from  the  leucocytes  of  the  thymus,  lymphatic  glnitds,  spleen 
and  testicles,  and  from  spermatozoa*  WlRHAlry  it  is  a  white  powder, 
soluble  in  water^  in  concentrated  acetic  and  mineral  acids,  in  solutions 


592 


MANUAL    OF    CHEMISTRY 


of  alkalies,  and,  when  freshly  precipitated,  in  solutions  of  NaCl  or 
MgSOi;  insoluble  in  alcohol,  methylic  alcohol  or  dilute  acetic  acid. 
It  eontaios  S.025  per  cent  phosphorus,  and  0.701  per  cent  sulfur.  Its 
solutions  are  dextrogyrous,  [tf]D=+37.5°.  When  hydrolysed  by  I 
lieating  with  BaH^Oj  or  dilute  HCl  it  yields  histon  (p.  587)  and  a 
nuclei n,  called  leuconudcin.  It  is  decomposed  by  aicohoHe  KHO, 
jieldiij^an  albumin  and  thymonueleic  acid  (p.  593).  Nucieohiston, 
or  tlie  leuconuclein  derived  frou)  it,  is  supposed  to  play  an  important 
part  in  tlie  coag^ulation  of  the  blood  (p.  GG9). 

Nucleins  are  obtained  as  insr^bible  or  sparingly  soluble  residues 
on  peptic  digestion  of  the  iiucleoiiroteids.  They  contain  4-7  per  cent 
of  phosphorus,  and  traces  of  iron.  They  are  colorless,  amorphous, 
very  sparingly  soluble  iu  water,  nicMieratety  soluble  in  dilute  alkalies, 
insoluble  in  alcohoi  and  iu  dilute  aculs,  not  dissolved  by  peptic  diges- 
tion, but  dissolved  by  tryptic  digestion.  They  beliave  as  rather  strong 
acids.  They  give  the  Millon  and  biuret  renctions,  and  readily  take  up 
basic  dyes  from  aqueous  or  alcoholic  solutions.  They  are  coagulated 
by  heat.  They  are  more  strongly  dextrogyrous  than  the  nucleoproteids. 

On  hydrolysis  by  boiling  dilute  acids  they  yield  albumin  products 
and  ueulcic  acids,  which  latter  are  further  decomposed,  yielding 
xanthin  and  uracil  bases,  a  carbohydrate  and  metaphosphoric  acid. 
Inversely,  compounds  having  the  properties  of  nucleins  are  produced 
by  precipitating  solutions  of  albumins  with  nucleic  acids.  As  they 
still  contain  albumins,  they  do  not  differ  essentially  from  the  nueleo- 
proteids,  but  are  rather  to  be  considered  as  nncleoproteids  more  rich 
in  phosphorus,  poorer  in  nitrogen,  and  more  strongly  acid  than  the 
native  nncleoproteids,  and  as  transition  products  between  the  nncleo- 
proteids and  the  nucleic  acids. 

Nucleic  Acids— also  called  fi hc let nk  acids,  are  products  of  decom- 
position of  imcleoproteids  by  alkalies,  either  directly  or  through  the  i 
nucleins.  They  are  amorphous,  white,  sparingly  soluble  in  water, 
easily  soluble  in  alkalies;  insoluble  in  alcohol  and  in  ether.  They  are 
precipitated  from  their  solutions  by  mineral  acids,  including  pbos- 
photuugstie,  by  alcohol,  and  by  (Nn4)2S04  in  presence  of  acetic  acid, 
but  not  by  acetic  acid  alone,  except  guauylic  acid.  Their  solutions! 
form  precipitates  (of  nnclt^ius)  with  acid  solutions  of  albumins.  They 
give  the  xanthoproteic  and  Adamkiewicz  reactions,  but  not  the  biuret 
or  Millon.     They  are  dibasic  acids,  forming  acid  and  neutral  salts. 

On  hydrolysis  the  nucleic  acids  yield  xanthin  and  uracil    bases, 
phosphoric  acid,  and  a  carbohydrate  as  final  products.     All  of  the| 
four  xanthin  bases  have  been  obtained  from  nucleic  acids.  It  is  believed 
that  there  exists  a  distinct  nucU^ic  acid  corresponding  to  each  xanthin 
base,   a  xanthylic,   a  hypoxanthylic   (mrrtjlir),  a  guanylic,  and  an  ( 
adenylic  acid,  although   but  one  of   these,  guanylic  acid,  has  been 


PR0TEID3 


503 


obtained  in  a  condition  of  purily.  An,  however,  certain  niicleoproteids 
on  hydrolysis  yield  more  than  one  xanthin  base,  and  aoine  as  many  as 
three,  it  is  possible  that  nucleic  acids  may  exist,  whose  molecules  coo- 
tain  more  than  one  xanthin  base.  Nor  does  tlie  hj^drolysis  of  the 
nucleoproteids  or  nucleic  acids  proceed  to  the  final  result  in  a  single 
stage.  From  the  parent  nucleoproteid  a  nucleic  acid  is  first  split  off, 
designated  as  an  a-acid,  which  is  very  sparingly  soluble,  and  whose 
solutions  gelatinize  if  tliey  contain  5  per  cent  or  more  of  the  acid. 
By  the  action  of  KIIO  about  two* thirds  of  the  totiil  xauthiu  bases  are 
split  olf,  and  a  0-ucid,  probably  an  inferior  polyinere,  is  obtained, 
which  is  more  soluble  than  tijea-acid  {but  see  gnanylic  acid,  below), 
arid  whose  solutions  do  not  gelatinize.  By  the  continued  action  of  the 
alkali  this  acid  splits  off  the  remainder  of  the  xauthiu  bases  and 
eytosin  (p.  525),  leavingthymic  acid,  which  then,  by  further  hydrolysis, 
yields  thy m in  {p.  524)*  a  carbohydrate,  phosphoric  acid,  and  other 
undetermined  products.  The  carbohydrate  coun>onent  is  most  fre- 
quently a  pentose,  giving  Tollens'  reaction  (p,  323),  sometimes  a 
hexose;  and  sometimes  hevulinic  acid  (p.  347)  is  the  carbohydrate 
representative.  Thymic  acid  is  quite  soluble  in  water,  and  is  not 
precipitated  by  mineral  acids.  Its  solutions  form  precipitates  in  acid 
solutions  of  albumins. 

Two  guanylic  acids,  C44Hfi6NLiiP40:u,  are  obtained  from  the  puu- 
creas:  the  a- acid,  easily  soluble  in  cold  water,  contains  6.65  per  cent 
phosphorus  and  15.38  per  I'cut  nitrogen.  By  the  action  of  alkalies 
it  splits  off  a  pentose,  1 -xylose,  and  forms  ^- guanylic  acid,  soluble  in 
hot  water,  less  soluble  in  cold  water,  routainiug  7.64  per  cent  phos- 
phorus and  18.21  per  cent  nitrogeu,  which  appears  to  beau  ester  of  a 
polyglyeerophosphoric  acid.  By  hydrolysis  it  yields  four  molecules 
of  guauin,  three  of  pentr>se,  aud  three  of  glycerol  for  each  four  atoms 
of  phosphorus,  but  no  other  xanthin  base  and  no  pyrimidin  derivative. 
In  it  P:N::4:9.5. 

Two  thymoTiuclcic  acids,  (*4oH,'^NiiPiO.50,  have  been  obtaiued  from 
the  tliynnis,  t*)  one  of  which  the  nnr'leic  acids  fnmi  the  melt  of  stur- 
ge<m,  salmon  and  herring  ai'e  closely  rehited,  if  they  be  not  ideuticaL 
They  yiehl  23  per  cent  P-jO,^.  and  P:  N  ::  4: 14,  They  are  hydrolysed  by 
beating  with  water,  yielding  adeniu,  guaniu  and  thymic  acid;  and, 
on  deeper  hydrolysis  by  rL>S(>t,  guaniu,  adeuiti,  thymin,  cytosiu,  aud 
Iftfvulinic  acid,  but  no  carbohydrate. 

The  two  principal  nucleic  acids  of  vegetalde  origin,  triticonucleic 
acid,  CuHfijXiuP^O:?!,  from  wheat,  ami  yeast  nucleic  acid,  mt\  if  not 
identical,  t-losely  related,  Ou  hydrolysis  by  acids  they  both  yitdd  one 
tnoleenle  each  of  adenin,  guaniu  and  cytosiu,  two  of  uracil,  and  three 
of  peulose  for  each  four  atoms  of  phosphorus.  Yeast  nucleic  acid  is 
also  said  to  yield  a  hexose. 
38 


394 


MANUAL    OF    CHEMISTBY 


Glycoproteids — are  proteins  which  ou  hydrolysis  by  dilute  mineral 
acids  yield  a  notable  qiiaotity  of  a  substance  capable  of  redutung 
Fehling:*s  solution,  but  no  xanthin  base.  Because  of  their  carbohydrate 
content  these  substances  contain  a  smaller  proportion  of  nitrogen  and 
of  carbon,  and  a  larger  proportion  of  oxygen  than  other  proteins. 
They  include  the  mucins  and  mecoids,  the  distinction  between  which 
is  not  sharply  drawn.  They  exist  in  the  saliva,  bile»  nasal  mucus, 
vaginal  mucus,  cornea,  vitreous,  tendons,  cartilage,  umbilical  cord, 
and  the  fluid  of  ovarian  cysts. 

When  dry  they  are  white  or  gray»  soluble  in  mnch  water,  to  acid 
solutions,  which  are  not  coagulated  by  heat.  In  presence  of  a  trace 
of  alkali  the  solution  assumes  a  viscous,  stringy  character,  which  is 
more  pronounced  with  the  mucins  than  with  the  mucoids,  this,  and 
some  differences  in  the  conditions  of  precipitation,  being  the  only  dis- 
tinctions between  the  two.  If  the  alkaline  solution  be  heated  the  proteids 
dissolve  as  alkali- albuminate.  The  glycoproteids  are  precipitated 
from  their  aqueous  or  cold  alkaline  solutions  by  acetic  acid,  the  pre- 
eipitate  being  insoluble  in  excess  of  acid.  They  are  also  precipitated 
by  alcohol.  They  are  insoluble  in  dilute  acids,  but  if  they  be  heated 
with  dilute  mineral  acids,  they  dissolve  as  acid -albuminates  or  alba- 
moses,  the  liquid  turns  brown,  and  is  capable  of  reducing  Fehliug's 
solution.  Tliey  are  dissolved  very  slowly  by  peptic  or  tryptic  digestion. 
On  hydrolysis  they  yield  30-37  per  cent  of  a  carbohydrate,  which  is 
usually  glncosamin  (p.  387),  which  probably  exists  in  the  parent 
substance  as  a  nitrogenous  polysaccharide 

Cartilage  contains  a  mucoid,  called  chondromucoid»  which  on 
hj'drolysis  by  dilute  mineral  acids  yields  albumin  products  and  nn 
ester -sulfuric  acid,  called  chondroitin- sulfuric  acid^  or  chondroitic 
acid.  This  acid  exists  in  cartilage  and  in  urine,  and  has  the  empirical 
formula,  Cisn27N80i7.  On  hydrolysis  it  first  splits  otf  H2SO4  and 
yields  chondroitin,  C1KH27NOU,  a  gummy,  monobasic  acid,  which  on 
further  hydrolysis  splits  off  acetic  acid,  and  yields  chondrosin, 
C12H21NO11,  also  a  gummy,  monobasic  acid,  soluble  in  water »  which 
reduces  Pebling-s  solution  more  energetically  than  does  glucose,  and 
is  dextrog>'rous.  On  further  hydrolysis  chondrosin  fields  a  tetra- 
oxyamidocaproic  acid,  CfiHisXOe,  and  an  undetermined  carbohydrate 
component.  Chondroitin -sulfuric  acid  is  a  white,  amorphous  powder, 
very  soluble  in  water,  as  are  its  salts.  Its  neutral  solutions  are  precip- 
itated by  SnCla,  PbOPb(C:iH302)2.  Fe^Cle,  and  alcohol.  Solutions  of  its 
alkali -metal  salts  cause  precipitates  in  solutions  of  albumins  or  of 
gelatin. 

The  fluid  of  ovarian  cysts  contains  a  pathological  glycoproteid, 
called  metalbumiti,  or  pscudomucio,  which  forms  a  viscid,  stringy 
solution,  which  becomes  opalescent,  but  does  not  coagulate,  on  being 


* 


ALBUMINOIDS 


r>95 


heated,  and  is  precipitated  by  alcohol,  Ijut  wbieli  differs  from  sulutiuiis 
of  other  glycoproteids  in  not  being  precipitated  by  acetic  acid.  Paral- 
butnin,  also  from  ovarian  cysts,  is  apparently  a  mixtnre  of  psendo- 
mnein  with  albumins. 

ALBUMINOIDS. 

The  albuminoids  are  proteins  which  are  insoluble  in  the  neutral 
BolventB  of  the  albumins  or  proteids.  They  can  only  be  dissolved  after 
undergoing  chemical  change.  They  are  of  denser  consistency  than 
the  other  proteins^  and,  while  the  albumins  and  proteids  are  constit- 
uents of  the  nutrient  fluids  or  of  the  nuclei  or  protoplasm  of  the  cells, 
the  albuminoids  occur  in  skeletal,  connective,  and  epidermal  tissues. 
The  albuminoids  are  also  much  more  resistant  than  other  proteins  to 
10  action  of  decomposing  agents,  but,  when  decomposed,  they  yield 
he  same  kind  of  decomposition  products  as  do  the  other  proteins, 
accept  that  certain  groups,  such  as  the  tyrosin  and  indole  complexes, 
Wre  absent,  while  other  groups  are  produced  in  larger  amount. 

Keratins — are  the  albuminoids  most  closely  allied  to  the  albnmios. 
jideed,  they  are  sometimes  classed  as  true  albumins,  because  of  the 
iarge  proportion  of  sulfnr  which  they  contain;  the  presence  in  tliem 
►f  a  carbohydrate  component;  and  the  occurrence  among  their  prod- 
lets  of  decomposition  of  arginin,  tyrosin  and  plienylalanin,  the  first  of 
rhich  contains  the  guanidin  remainder  and  the  last  represents  the 
mdole  complex,  which  are  present  in  the  albumins,  but  usually  absent 
the  albuminoids. 

The  keratins  occur  in  epidermis,  hair,  nails,  horn,  hoofs,  feathers, 
jortoise- shell,  and  other  epidermic  tissues,  in  brain  and  nerve  tissue 
xieuro- keratin)^  and  in  the  membranes  of  eggs.  They  vary  in  com- 
sition:  Hair  keratin  contains  16.80  to  17.14  per  cent  nitrogen  and 
to  5  per  cent  sulfur;  and  neurokeratin  11.46  per  cent  nitrogen  and 
^7  per  cent  sulfur.  The  maximum  of  sulfur  is  in  the  keratin  of 
Txrann  hair,  which  yields  up  a  portion  of  its  sulfur  very  readily,  form- 
^  H28  even  with  boiling  water,  a  fact  which  is  utilized  in  lead  and 
ter  metallic  hair  dyes.  The  keratins  are  amorphous,  insoluble  in 
^^ter,  alcohol,  ether,  acids,  gastric  juice,  or  trjT>sin,  slowly  soluble 
alkalies.  When  heated  with  water  under  pressure  to  150*^*200**, 
<5y  dissolve,  but  do  not  gelatinize.  They  give  the  xanthoproteic 
td  Mil  Ion  reactions,  sometimes  imperfectly.  Horn  and  hair  on 
't5om position  yield  alanin,  a-amidovalerianic  acid,  leucin,  aspartic 
'td,  serin,  tyrosin,  arginin,  lysin,  phenylalanin,  and  a*pyrollidin 
ifboxylic  acid  as  nitrogenous  split  products.  Most,  if  not  all,  of  the 
*^lfur  is  obtained  as  cystin:  from  horn  6.8  per  cent,  and  from  human 
Wr  13.92  per  cent. 

Albumoid  is  a  substance  intermediate  between  the  keratins  and 


696 


MANUAL    or    CHEMISTRY 


the  albumins,  obtained  from  traclieal  cartilages.     It  is  soluble  in 
trie  juice,  but  in  other  respects  resembles  tlie  keratins. 

Collagen — is  the  principal  constituent  of  eonnective  tissues,  bon 
(liSseTn),  tendons  and  cartilage.  In  the  last  named  it  exists  in 
binatiou  with  cbondroitin  sulfates  {p.  594).  When  dry  it  is  amof^ 
phoiis,  yellowish,  hard,  aud  iosoluble  in  water,  or  dilute  acids  or 
alkalies.  W^hen  macerated  with  cold  dilute  acids  it  becomes  pliable. 
The  tannins  combine  with  collagen  to  form  a  tough,  hard,  iajpnt 
cibie  niateriiil,  which  constitutes  leather.  Collagen,  when  heated  wilj 
dilute  acids,  or  with,  water  under  pressure,  is  converted  into  gelat 
which  appears  to  be  a  hydrate  of  the  parent  substance.  Glue  is  i 
impure  form  of  gelatin.  Gelatin  is  amorphous,  yellowish,  hard,  britrl^ 
swells,  but  does  not  dissolve,  in  cold  water,  and  at  30°  forms  a  soli 
tion  with  water,  which  solidifies  to  a  jelly-like  mass  on  cooling,  au 
liquifies  when  warmed.  Gelatin  and  collagen  give  the  xanthoproteic 
and  biuret  reactions,  but  not  the  Mil  Ion  or  Adamkiewiez,  Vfhe 
liydrolysed  by  acids  they  yield  the  usual  decomposition  products  of  ih 
proteins,  except  that  they  yield  no  tyrosin,  indole,  or  cystin.  Th^ 
do,  however,  contain  sulfur,  and  also  an  aromatic  eomplex  in  sma 
amount,  as  they  yield  0,4  per  cent  of  phenylalanin.  They  yifl 
glycocoll  in  large  amount,  16,5  per  cent,  and  smaller  quantities 
alanin,  leucin  and  other  monamido  acids  and  diaraido  acids  (2:5] 
cent  argiuin).  They  contain  no  carboljydrate  component.  Collagpil 
if  previously  heated  with  water  to  70°,  and  gelatin  are  dissolved  bj 
peptic  or  tryptic  digestion  with  formation  of  gelatoses  and  gelatin- 
peptones,  which  are  diffusible^  and  during  whose  formation  a  considt-r- 
able  amount  of  glyeocoJl  separates.  These  digestion  products  of  gelatin 
are  not  identical  with  those  derived  from  the  true  albumins  (p.  619),^ 
aud  gelatin  is  capable  of  only  partially  replacing  albumins  in  a  dietai; 
Isinglass,  a  colorless,  transparent  gelatin  from  the  swimming  bladJefl 
of  certain  fishes,  and  gelatin  made  from  cartilage  differ  from  ordiuai; 
gelatin  in  being  completely  soluble  in  water.  They  contain  chondroiti^ 
sulfates  as  well  as  gelatin. 

Elastin — occurs  in  elastic  tissues,  notably  the  ligamentum  nuclia»._ 
When  dry  it  is  a  yellow  powder,  insoluble  in  neutral  solvents,  on 
slowly  soluble  in  boiling,  concentrated  KHO,  or  concentrated  HjSC 
soluble  in  hot  HCl.  It  contains  0,27-0.66  per  cent  of  sulfur,  which  I 
completely  split  off  by  NallO.  It  gives  the  xanthoproteic.  biurH. 
Millon  and  Adarakiewicz  reactions  after  solution  by  NaHO,  Ou 
hydrolysis  it  yields  notable  quantities  of  leucin,  45  per  cent,  smaller 
araonuts  of  other  monamido  acids,  ami  very  small  quantities  of  tyrci^in. 
0.25  per  cent,  and  of  diaoiido  acids  0.3  per  cent,  but  no  indole  or 
skatole.  By  the  action  of  proteolytic  enzymes  it  jnekls  two  albumoses, 
both  soluble  iu  water,  one,  protoelastose,  preeipitable  by  heat,  by 


CHEMICO-PHYSIOLOGICAL    PROCESSES 


597 


mineral  acid^,  or  by  acetic  acid  aud  fermcyuiiid,  the  other,  deutero* 
slastose,  nut  so  precipitable, 

Otlier  aibuiniiioids  tire:    Reticulin.  from  connective  tissues,  iiitefe*- 

liaai  itJiKHJUs  uientbraoe,  liver,  spleeu,  kidneys,  Itiui^s;   contains  phus- 

[jhoruis.     Spongin   is  the  principal   org^auic  eonstitneut  of  sponges. 

Lonchiolin  is  the  albuminoid  of  the  shells  of  iiiuUnses,  Fibroin  and 

(sericin  are  tlie  principal  constituents  of  raw  silk.    Kornein  is  obtained 

rum  coral  zoiiphytes,     Ichthylcpidin  exists,  alon^j  with  eollagen,  in 

liih  scales.  Chitin  eoostitutes  the  orgaoKi  portion  of  the  hard  parts  of 

isects  and  crustaceans.    It  probably  is  not  a  protein,  but  a  nitroge- 

aous  polysaccharide  whose  product  of  hydrolysis  is  glucosamine  or 

Bhitoseamin. 

Amyloid^is  a  purely  pathological  producD  which  appears  as  the 

?ra  amtflttcea^  resembling  starch  granules  in  gross  appearance,  or 

osited  in  masses  in  amyloid  degeneration  of    the  pareneiiyma  of 

le  liver,  kidneys,  spleen,  etc.     It  is  white,  amorphous,  insoluble, 

tcept  in  concentrated  acids  and  alkalies,  and  only  slowly  dissolved  by 

jptic  or  tryptic  digestiun.    It  gives  all  of  the  protein  eohn'  reactions. 

in  hvtlrolysts  it  yields  3.9  per  cent  tyroain,  leucin  and  aspartie  and 

flutaiuie    acids.     It    contains   no  carbohydrate  component,  but  does 

contain  a  ehondroitin  sulfuric  acid  complex.     It  is  colored  brown -red 

jy  iodin,  changing  to  violet  on  addition  of  H2SO4;    and  is  colored 

}right-red  by  eosin,  rose -red  by  anilin  violet,  and  red  by  anilin  green, 

Melanins — are  dark-colored  substances  occurring  in  hair,  choroid, 

'iris,  akin  of  the  negro,  and  in  melanotie  tumors.     The  melanoidins 

which  remain  in  the  hniaus  fraetinn   (p.  580)  on  decomposition  of 

[proteins  are  related  to  thera,  and  their  percentage  composition  is  sim- 

lilar  to  those  of  the  proteins.     They  are  eertaiidy  protein  derivatives, 

[if  they  be  not  albuminoids.     Some  contain  sulfur  and  iron,  others  do 

llint.     Their  content  of  nitrogen  varies   from  8.5  to   12.3  per  cent, 

|f>f  sulfur  from  0  to  10  per  cent,  and  of  iron  from  U  to  2.7  per  cent. 

IWhen  dry  they  are  l)rown  or  black,  amorphous,  insoluble  in  neutral 

l8ol vents,  and  in  dilute  acids;  soluble  in  coneentrated  acids,  and  readily 

[eoluhle  in  alkalies.     They  do  not  give  the  protein   color  reactions. 

pndole  and  skatole  have  been  obtained  as  products  of  their  hydrolysis. 

l)ut  neither  tyrosin  or  other  amido  acids. 


CHEMICO-PHYSIOLOGICAL   PROCESSES. 


One  of  the   most  striking  differences  between  unorganized  and 

^organized  nature  is  that  in  the  farmer  those  changes  which  occur  are 

almost  entirely  physical,  while  in  the  latter  they  are  essentinJly  cheni* 

leal.    Water  passes  through  the  conditions  of  solid,  liquid  and  vapor» 


598  MANUAL    OF    CHEMISTRY 

the  rocks  are  eroded,  the  air  varies  in  temperature  and  moves  from 
place  to  place,  all  physical  changes,  but  neither  water,  rock  nor  air 
suffers  change  of  composition.  But  in  vegetable  and  animal  bodies 
changes  in  composition  are  constant  and  essential  to  life;  the  atoms 
of  carbon,  hydrogen,  nitrogen  and  oxygen  are  in  constant  passage 
from  one  form  of  combination  to  another.  Indeed  life  may  be  sa^ 
to  consist  of  chemical  reactions;  and  the  physical  processes  and  eon- 
ditious  of  and  in  the  bodies  of  vegetables  or  animals  occur  or  exist 
that  these  reactions  may  take  place. 

Energy,  like  matter,  is  indestructible,  and  cannot  be  created. 
The  sum  of  potential  and  kinetic  energy  in  the  universe  is  immutable. 
The  relative  proportions  of  the  two  forms  of  energy  is  constantlj 
varying.  Every  chemical  change  involves  the  conversion  of  poten- 
tial into  kinetic  energy,  or  the  reverse.  The  atoms  of  carbon  and 
oxygen  uncombined  with  each  other,  are  endowed  with  a  definite 
amount  of  potential  energy,  which  is  converted  by  their  union  into 
a  definite  and  equivalent  amount  of  kinetic  energy,  which  is  mani- 
fested and  is  measurable  as  heat,  which  may  in  turn  be  converted 
iuto  other  forms  of  energy.  Once  united,  the  carbon  and  oxygen 
have  lost  the  potential  energy  which  they  possessed  while  ununited, 
and,  as  energycannot  be  created,  they  can  only  recover  it  by  some 
secjond  reaction  in  which  an  equivalent  quantity  of  kinetic  energy 
becomes  potential  in  separating  the  atoms  once  more.  This  cyck 
may  be  mathematically  expressed  by  the  equations:  C+O2+ potential 
=  C02+kinetic,  and  C02+kinetic  =  C+02  + potential.  As  animal 
bodies  are  constantly  converting  potential  energy  into  the  kinetic 
forms  of  heat,  motion,  etc.,  they  must  be  supplied  with  potential 
energy  from  without,  which,  in  its  turn,  has  been  derived  from  some 
form  of  kinetic  energy. 

The  source  of  this  energy  is  the  kinetic  energy  of  the  sun's  rayg. 
The  green  parts  of  plants  owe  their  color  to  the  presence  of  a  pig- 
ment called  chlorophyll,  which  is  only  present  in  leaves  and  stems 
exposed  to  sunlight.  In  the  daytime,  and  while  exposed  to  sunlight, 
plants  absorb  carbon  dioxid  from  the  air  and  give  off  oxygen;  daring 
the  night  they  absorb  oxygen  and  evolve  carbon  dioxid;  but  in  very 
much  less  quantity.  Plants  also  absorb  water  and  ammonia.  Prom 
these  comparatively  simple  substances  the  plants  form  carbohydrates 
and  proteins  under  the  influence  of  the  kinetic  energy  of  the  snn's 
rays,  which  thereby  becomes  potential.  In  the  animal  body  the  ca^ 
bohydrates  and  proteins  are  converted  into  carbon  dioxid,  water  and 
urea  (the  last-named  yields  ammonia  by  fermentation)  and  their 
potential  energy  becomes  kinetic.  The  tissues  of  the  plant  are, 
directly  or  indirectly,  the  food  of  the  animal,  and  the  excreta  of  the 
animal  constitute  the  food  of  the  plant.     The  chemical  processes  ia 


FERMENTS    AND    ENZYMES 


599 


the  vegetable  ai'e  essentially  syothetic,  pirodticing  complex  substances 
from  simpler  forms  of  combination;  but  analytic  processes  also  occur 
in  vegetables,  as  tbat  whicli  results  in  the  evolution  of  oxygen,  above 
referred  to.  The  processes  of  animal -nature  are,  on  the  other  hand, 
essentially  analytic,  complex  combinations  being  reduced  to  simpler 
forms;  but  synthetic  processes  also  occur  in  animai  bodies,  as  in  the 
formation  of  hippuric  and  the  ester -sulfuric  acids. 

The  composition  of  various  articles  used  as  foods,  the  effects 
npon  them  of  different  methods  of  preparation,  and  the  relative 
proportions  in  which  the  several  components  shonki  be  contained 
in  properly  adjusted  dietaries,  are,  like  the  composition  of  air  under 
varying  conditions,  important  subjects  of  inquiry  for  the  hygienic 
chemist.  In  this  place,  however,  we  will  content  ourselves  with  the 
statement  that  the  nxaterials  required  for  the  chemical  processes 
taking  place  iu  the  body,  and  contributing  to  the  growth  or  repair 
of  the  tissues,  and  to  the  production  of  kinetic  energj%  are  of  six 
classes:  (1)  Oxygen,  (2)  water,  (3)  mineral  salts,  (4)  carbohydrates, 
(5)  fat,s,  (6)  proteins.  Of  these,  oxygen,  water  and  salts  pass 
into  the  system  by  the  physical  processes  of  diffusion  and  absorption, 
without  the  necessity  of  any  preliminary  chemical  treatment.  But 
the  fats,  the  carbohydrates,  and,  notably,  the  proteins,  require  chemi- 
cal modification  from  the  forms  in  which  they  are  taken  into  the 
mouth  before  they  can  be  absorbed.    This  is  the  purpose  of  digestion. 

Chemical  processes  occurring  in  the  body  may  therefore  be  divided 
into  the  two  classes  of  preparatory  aud  essential.  The  former  in- 
cluding the  processes  preparatory  to  absorption  which  occur  in  the 
alimentary  canal;  the  latter  the  metabolism  of  the  tissues,  cells,  and 
fluids  of  the  body. 

FERMENTS   AND    ENZYMES. 

Bince  the  historic  researches  of  Pasteur,  and  until  quite  recently, 
the  name  ferment  has  been  applied  to  certain  microorganisms:  mould 
fungi,  yeast  fungi  and  bacteria,  which  by  their  growth  cause  definite 
chemical  changes  in  certain  substances  contained  in  the  media  in 
which  they  develop.  En^mes  are  more  or  less  hypothetical  sub- 
stances, some  of  which  are  derived  from  the  microorganisms  above 
referred  to,  all  produced  by  living  cells,  aud  exert  their  characteristic 
actions.  There  is  at  present  a  tendency  to  use  the  terms  ferment  and 
enzyme  synonymously  to  apply  to  the  latter,  which  is  to  be  regretted, 
even  if  all  ferments  be  shown  to  act  by  producing  enzymes,  as,  if  fol- 
lowed, it  causes  a  useless  multiplication  of  names  on  the  one  hand, 
and,  on  the  other,  leaves  the  important  class  of  organized  ferments 
generically  nameless. 


600 


MANUAL    OP    CHEMISTRY 


Alcoholic  fermentation  as  cooducteJ  by  brewers  and  distillers  is 
tlie  result  of  the  oi^^tabolH?  pniepsses  in  the  growth  of  the  yeast  plant, 
duriug  which  glucose  is  cutisiuued  and  earbuu  dioxul  and  alcohol  are 
eliminated,  Breivers^  yeast  is  a  fungus,  8a€charom}f€4s  cerevma^ 
which  forms  rounded  or  elongated  wlU,  whijse  j^realefet  diameter  is 
8-10  ^  and  whieli  i>ropugatei>  by  buddiug.  Two  varieties  of  thi^ 
plant  exist,  corresponding  to  the  "low  yeast,"  which  sinks  to  the  bot- 
tom of  the  fermenting  liquid,  and  the  "high  yeast,"  which  rises  to  the 
surface.  Vinons  fermentation  is  usually  produced  by  S.  elipsoUUus, 
but  also  by  S.  apicidaftts  and  8,  rasteuriiuius,  which  exist  upon  tlie 
skins  of  grapes  and  other  fruits.  S.  cereviHki  produces  alcoholic 
fermentation  not  only  of  glucose,  but  also  of  sarchurose  and  maltose, 
which  involves  the  preliininury  inversiun  of  these  disaccharids.  Cer- 
tain other  yeasts  behave  differently  with  sugars  other  than  glucose: 
8.  apiculaius  does  not  ferment  (invert)  either  maltose  or  saccharose; 
8,  ociosporns  and  8.  memhraitaftu'ifns  ferment  maltose  but  not  sac- 
charose; ^\  Marjriantts  and  8,  LutUvitfii  ferment  saccharose  but  not 
maltose*  Of  the  monosaccharids  ouly  the  dextro  sugars  contaiuiDg 
Ca  or  a  multiple  thereof  are  fermentable.  Glyceric  aldehyde  and  the 
d-hexoses  are  fermented  by  yeast;  the  1-hexoses,  pentoses,  hfptoses  and 
ostoses  are  not.  The  disacfdiarids,  saccharose,  lactose  and  maltose, 
and  the  trisaccharid,  raflinose,  only  ferment  after  inversion. 

The  most  frivorable  temperature  for  the  action  of  yeast  is  24°.  At 
55°H}D°  the  life  of  the  plant  is  destroyed.  It  is  also  killed  by  micrnbic 
poisons,  such  as  chloroform,  thymol,  toluol,  carbolic  acid,  boric  acid, 
mercuric  eblorid,  etc.  The  action  is  also  arrested  by  accunuilation  of 
the  product  when  the  proportion  of  aleoliol  reaches  20  per  cent.  Ethyl 
alcohtd  is  by  no  means  the  only  product  of  yeast  fennentation; 
aldehyde,  normal  pro py lie,  isobutylie  and  isoamylic  alcohols,  oenan- 
thy  lie  ester,  isobntylene  glycol,  glycerol,  acetic  and  succinic  acids,  and 
furfurole  are  alsc*  formed. 

Certain  mould  fungi  also  cause  alcoholic  fermentation.  Thus  Mucor 
inucah,  M.  ajiernaita,  M,  racefm^sns,  Amylomyces  Ronxii  produce 
alcohol  not  only  from  glucose  but  also  from  dextrins  and  from 
liydrated  starch  when  growing  submerged  in  the  liquid.  EuroHnm 
orkm  is  an  aspergillus  used  by  the  Japanese  to  ferment  rice  in  the 
preparation  of  "sake,^' 

The  selective  action,  above  referred  to,  which  yeast  and  other  fer- 
ments exhibit  toward  optical  isomeres  has  been  explained  (Fischer) 
by  the  supposition  that  the  enzymes  by  which  their  action  is  prodaeed 
(below)  themselves  possess  a  stereochemical  configuration  (p.  311) 
which  permits  of  their  adaptation  with  a  sugar  w^hose  conformation  is 
receptive,  but  not  with  its  stereoisomere,  the  spatial  arrangement  of 
w^hose  parts  is  obstructive  to  such   interunion.     A  similar  selective 


4i 


FERMENTS    AND    ENZYMES 


601 


f 


action  is  exertetl  by  eertaiu  niould  fungi,  such  as  PeniciUitim  glaucum 
(the  comraun  blue  mould)  and  Aspergillus  niger^  wbosse  selective  power 
is  ntiliased  for  the  sepa radon  of  one  optically  active  modiiieatiou  from 
a  raeemic  form.  Tlnis  wheu  these  nioukis  are  grown  upou  iuaetive 
aTniuonium  huitutc  otilv  the  dextrolactate  remains.  They  also  exert  a 
selective  action  between  other  stereoisomeres.  Thus  in  a  mixture 
of  fu marie  and  maleie  acids  they  eonsurae  the  former  and  leave 
the   latter. 

Bacterial  ftrmcntations  occur  iti  great  variety.  The  slimy  material 
koowii  popularly  as  "mother  of  vinegar"  is  formed  of  Barierium  aceti, 
which  iu  its  growtli  eauses  acetous  fermentation  in  weak  alcoliolic 
liquid.s,  by  oxidizing  ethylic  alcuhol  to  acetic  acid.  Butylic  fermen- 
tation is  produced  by  Baeilhis  hniiflieus,  which  splits  glycerol,  mono- 
saccharids,  disaccluirids,  dextrin,  and  starch  with  formation  of  nonnal 
butyl  ali'ohol  and  small  quantities  of  is<ibntyi  alcohoK  Possil)ly  the 
formation  of  the  higher  alcohols  in  *irdiuary  alcoholic  fermcntatiun  may 
bedu*/to  the  presence  of  this  and  other  bacteria  iu  the  yeast.  Butyric 
fermentation  is  set  up  by  a  variety  of  bacteria,  notably  by  BiH-illits 
amt/Iohttrtet\  which  exists  in  soils,  river  waters,  hay,  etc.,  and  in  the 
iutestine.  The  formation  of  butyric  acid  is  sometitnes  directly  fnmi 
the  carbohydrate:  C0H12O0— C4H8O2+2CO2+2H2,  and  sonretimes  witli 
intertnediate  formation  of  lactic  acid:  CeHrjOo^^'^C^HeOi,  Lactic 
fermentation  is  produc^ni  by  a  number  of  species  of  bacreria.  In  tlit* 
souring  of  niilk,  in  which  the  lactose  is  first  hydrolysed,  and  its  con- 
stituents then  split  to  lactic  acid,  Bfteilhis  acitU  iadivi  is  usually  the 
most  active.  It  produces  the  raceniie  acid,  alnng  with  formic  and 
acetic  acids,  alcohol,  carbon  dioxid  and  hydrogen.  The  growth  of 
this  bacterium  is  most  active  at  35^-45*^,  and  is  arrested  by  slight 
excess  of  free  acid.  Therefore  a  better  yield  is  obtained  iu  presence 
of  raCO't  to  neutralize  tlie  acids  formed.  It  also  causes  lactic  fermen- 
tatinn  of  glucose  and  of  saccharose.  Bacterium  cali  rommmie  causes 
lactic  fermentation  of  both  glucose  and  saccljarose,  and  produces 
d-lactii!  acid.  The  typhoid  bacillus  ferments  glucose  but  not  saccha- 
rose, and  produces  1-  and  r- lactic  o<*ids.  Mixed  lactic  and  alcoholic 
fennentations  are  set  up  by  lactic  at  1  alc«diolic  ferments  growing  in 
the  same  medium.  Thus  in  the  manufacture  uf  *'kcfir,"  an  alcoholic 
beverage  made  from  milk,  BariUus  ettifntsints  nnd  SacrharonufPK^  kSfir 
ai'e  simultaneously  in  action.  The  ammoniacal  fermentation  of  urine, 
in  which  urea  is  hydrolysed  to  carbon  dioxid  and  ammonia  by  the 
action  of  Microcwrns  urfw,  is  one  case  of  a  great  variety  of  bacterial 
fermeutatitjus  of  niin^genous  materiuU  including  putrefaction,  the 
nitritication  of  natural  waiters,  etc..  which  result  in  the  decomposition 
of  complex  molecules  to  tlie  simpler  forms  in  which  nitrogen  ami  car*^ 
bon  may  be  utilized  as  plant -food.    It  is  highly  probable  that  diseases 


602  MANUAL    OP    CHEMISTRY 

of   bacterial  origiu  are  the  mauifestatious  of   the  action  of  specific 
poisons,  formed  as  fermentation  products  by  the  bacteria. 

Sucrase — Maltase — Zymase. — It  has  been  long  known  that  a  fil- 
tered extract  of  certain  yeasts  made  with  thymob'sed  water  is  capable 
of  inverting  cane-sngar,  and  that  similar  extracts  from  other  yeasts 
hydrolyse  both  saccharose  and  maltose.    From  which  it  may  be  inferred 
that   certain   yeasts   produce  a  non- organized  substance,  soluble  in 
water,  which  is  capable  of  inverting  saccharose,  and  which  is  called 
invertin,  or  invertase,  or  sucrase;    and   that  other  yeasts  secrete, 
besides   sucrase,    another   similar   material,    called    xnaltase,   which 
hydrolyses  maltose.     But,  although  the  chief  function  of  yeast  ia  the 
production  of  alcohol,  no  soluble  substance  is  obtainable  from  it  by 
mere   extraction   with   water,  which  causes   alcoholic  fermentation. 
Quite  recently  Buchner,  by  grinding  yeast  with  fine  sand  and  kieselgnhr, 
by  which  treatment  the  yeast  cells  are  ruptured,  and  then  subjecting 
the  mass  to  great  pressure,  obtained  a  liquid  which,  after  thorough 
filtration,  readily  produces  alcohol  and  carbon  dioxid  from  saccharose. 
This  liquid  therefore  contains,  besides  the  sucrase  above  mentioned, 
another  soluble  substance,  called  zymase,  capable  of  splitting  glucost 
to  alcohol  and  carbon  dioxid.     And,  as  this  latter  agent  can  only  be 
obtained  after  rupture  of   the  yeast  cells,  it  may  be  considered  as 
demonstrated    that  these   cells   produce   two   kinds   of  active  sub- 
stance, one,  the  sucrase  or  maltase,  which  it  excretes  to  perform  its 
function  in  the  medium  external  to  the  cell,  and  the  other,  the  zymase, 
which  acts  within  the  cell. 

Sucrase  exists  in  all  Saccharamyces  capable  of  fermenting  cane- 
su^jar  (not  in  S.  octosporus^  S.  memhrancefaciens^  or  S,  apiculatns),  in 
man}'  mould  fungi  {Penicillium  glaucnm,  Aspergillus  niger,  A.  oryza, 
Miicor  racemosus,  etc.),  in  certain  cells  of  germinating  seeds  of  higher 
plants,  in  the  bodies  of  bees,  and  in  the  intestinal  mucous  membrane 
and  liver  of  higher  animals.  An  active  preparation  of  sucrase  is 
obtained  by  Osborne's  method:  500  gm.  of  yeast  are  rubbed  up  with 
500  cc.  of  96  per  cent  alcohol,  and  the  mixture  allowed  to  stand  24 
hours.  The  alcohol  is  then  filtered  off  and  the  residue  macerated  in 
500  cc.  of  chloroform  water  for  six  days  at  30°-35°.  The  aqueous 
liquid  is  then  filtered  into  96  per  cent  alcohol,  and  the  flocculent 
precipitate  washed  with  absolute  alcohol,  and  dried  in  vacuo  over  sul- 
furic acid.  The  product  still  contains  a  notable  quantity  of  salts, 
which  may  be  in  great  part  removed  by  frequent  agitation  of  20  gms. 
of  the  material  with  500  cc.  of  water,  treatment  with  ammonia  to 
precipitate  earthy  phosphates,  filtration,  dialysis,  concentration  to 
small  volume  in  vacuo  at  30°,  reprecipitation  by  alcohol,  and  drying 
in  vacuo. 

Sucrase  hydrolyses  saccharose  and  raffinose,  but  neither  maltose 


FERMENTS   AND    ENZYMES 


nor  lactose.  In  the  dry  state  it  may  be  heated  to  160^  without 
deterioratioti,  but  when  moist  it  is  slowly  destroyed  at  45*^,  It  acts 
iwosi  etier^etieally  at  55'^.  A  small  quantity  of  acid  favors  its  action, 
but  larger  amouots  impede  it»  as  do  alkalies  in  small  amount. 

Maltase  exists  in  yeasts  (not  iu  S.  Marxianus  or  *S\  Lndwigii)  and 
in  mould  fuuiji,  and  is  widely  disseminated  in  the  animal  economy^  in 
saliva,  intestinal  Juice,  pancreas,  liver,  lungs,  lymphatic  glands,  spleen^ 
kidneys,  testicles,  blood,  urine,  and  bile.  It  is  best  obtained  from 
maize  by  extraction  with  water  containing  alcohol  and  tartaric  acid, 
and  precipitation  by  alcohol.  Maltase  obtained  from  yeast  and  those 
of  animal  origin  differ  in  certain  of  their  actions,  thus  the  former 
saponifies  a -methyl  glucosid,  which  the  latter  do  not.  Chloroform 
hinders  the  action  of  maltase,  but  is  indifferent  to  sucrase  and  to  most 
of  the  agents  of  this  class. 

Zymase  is  unstable  in  solution,  but  retains  its  activity  when  the 
extract  is  evaporated  to  dryness  in  vacuo  at  20*^^25°,  Or  the  pre- 
cipitate formed  in  its  aqueous  solution  by  alcohol  may  be  similarly 
dried.  It  acts  best  at  22°,  and  iu  solutions  containing  16  ptr  cent  of 
sugar.  Small  quantities  of  acids  arrest  its  action,  which  is  favored  by 
small  quanf  ities  of  alkalies.  Its  action  is  also  arrested  by  hydrocyanic 
acid  and  by  formic  aldehyde. 

Enzymes. — Sucrase,  maltase  and  zymase  are  representatives  of  a 
numerous  class  of  agents  which  play  important  roles  in  vegetable  and 
animal  life,  and  which  are  called  enzymes,  or  zymases,  or  soluble 
ferments.  The  general  characteristic  of  these  agents  is  that  they  are 
capable  of  causing  change  in  a  large  amount  of  the  materials  upon 
which  they  exert  their  specific  actions,  while  they  themselves  i-emain 
unaltered.  Thus  it  is  claimed  that  pepsin  can  digest  aOO^OOO  times 
its  weight  of  fil>rin,  and  be  recovered,  still  active,  from  the  solution. 
They  are  soluble  in  water  and  in  glycerol,  and  are  precipitated  from 
these  solutions  by  alcohol,  or  by  salting  out  from  aqueous  solution  by 
ammonium  sulfate.  Prolonged  cotitact  with  alcohijl  destroys  the 
activity  of  most  enzymes,  but  not  of  all.  For  each  there  is  a  definite 
temperatnre  which  is  the  "temperature  optima"  at  which  the  action  is 
most  energetic;  and  all  are  destroyed  at  TS'^-SO^.  Each  produces  its 
best  action  only  in  a  medium  of  a  certain  reaction.  Thus  pepsin  acts 
welt  only  in  an  acid  liquid,  trypsin  only  in  one  which  is  alkalint*.  The 
action  of  all  enzymes  is  hindered  by  accumulation  of  their  i>roducts. 
The  presence  of  certain  substances,  most  of  which  are  poisonous  to  the 
higher  animals  and  all  of  whieh  are  destructive  to  the  organized  fer- 
ments, inhibit  the  action  of  enzymes.  Such  are  mercuric  clilorid, 
CMrbolic  acid,  hydrocyanic  acid,  etc.  The  action  of  most  enzymes  is 
hydrolytic  in  character,  as  iu  the  splitting  of  di-  and  polysacfharids, 
the  saponification  of  fats,  the  decomposition  of  urea,  and  tlie  spiilting 


6M 


MANUAL    OF    CHEMISTRY 


of  the  gfhicosids,  but  there  are  .soiiiP  wlHi*h  produce  oxidations,  as 
laccase  and  tyrosinase,  or  simple  decompositions,  as  zymase;  indeed, 
there  appears  to  be  no  limit  to  the  possibilities  of  their  actions.  Their 
actions  do  not  proceed  to  completion,  at  least  in  some  cases,  and  there- 
fore it  is  theoretically  prol>able  that  the  reactions  are  reversible  (p.  89). 
In  fact,  in  the  action  of  maltase  upon  maltose  it  has  been  shown  that 
when  a  certain  proportion  of  glucose  has  been  produced  the  action 
ceases,  and  that  if  glucose  be  then  removed  the  hydrolysis  of  maltose 
contiiines,  but  if  glucose  be  added  umltose  is  produced.  The  lallei* 
action  is  clearly  synthetic,  and  it  is  also  probable  that  the  synthetic 
formation  of  hippurie  acid  in  the  kidney  is  due  to  enzyme  action. 
Some  enzymes  are  produced  iu  cells  from  which  they  are  excreted  to 
act  in  the  surrounding  media,  as  sucrase  and  pepsin;  others  act  withia 
the  cells  iu  which  they  are  produced,  as  zymase  and  the  several  anto- 
lytic  enzymes.  Enzymes  iu  general  decompose  hydrogen  peroxid  with 
liberation  of  oxygen,  but»  as  a  temperature  of  6i>'''  destroys  this  power, 
frequently  without  affecting  the  characteristic  action  of  the  enzyme, 
the  deeorn  posit  ion  of  hydrogen  peroxid  may  be  due  to  fortngn  sub- 
stances, although  such  cannot  be  the  case  with  colloidal  platinum 
(below).  Certain  cells  produce,  not  the  enzyme  itself  but  a  precnrser, 
a  zymogen,  or  proenzym,  from  winch  the  euzyuje  is  developed  by 
secondary  action.  Thus  pepsin  and  thrombin  are  foruied  from  pep- 
sinogen and  prothrombtu*  Most  enzymes  ujay  be  extracted  by  water, 
to  which  thymol  or  chloroform  is  added  to  prevent  bacterial  action, 
or  by  glycerol.  Another  method  of  their  separation  from  a q neons 
solution  is  by  the  formation  therein  of  a  precipitate  of  calcium  phos- 
phate, or  other  indifferent  insoluble  substance,  which  carries  the 
enzyme  down  mechanically.  The  precipitate  is  then  washed,  dissolved 
iu  dilute  hydrochloric  acid,  and  the  solution  subjected  to  dialysis. 

Concerning  the  chemical  nature  of  the  enzymes  nothing  is  known 
with  certainty,  as  no  enzyme  has  yet  been  obtained  in  a  condition 
approaching  purity.  It  has  been  supposed  that  they  are  proteins, 
from  their  instability,  their  precipitation  by  salting  and  by  alcolml, 
the  apparent  nitrogen  content  of  some  of  them,  and  their  nou-diffnsi- 
bility.  Bat  it  is  by  no  means  certain  that  some  at  least  of  them 
contain  any  nitrogen.  It  has  been  suggested  (Arthus)  that  they  are 
not  individual  substances,  but  conditions  of  some  existent  substance 
or  substances.  This  view  is  supported  by  the  discovery  by  Bredig' 
and  V.  Berneck  of  "mineral  enzymes."  If  an  electric  arc  be  passed 
between  platinum  points  under  water  a  dark -brown  ^* colloid  solution  '' 
IS  obtained,  containing  metallic  platinum  in  a  state  of  extremely  fine 
subdivision.  This  colloid  platinum  exhibits  the  action  of  an  enzyme  in 
decomposing  hydrogen  peroxid  energetically  and  in  very  large  amount, 
and  such  action  is  modified  by  various  agencies  in  the  same  waj^sas  is 


^ 


FERMENTS    AND    ENZYMES 


605 


tliat  of  an  enzyme.  Tbere  is  a  tfiiiperature  optima,  and  complete  arret^t 
of  tbe  action  hy  heat,  a  diiniimtioii  of  aetioii  with  increase  of  alkalinity , 
and  airest  of  action  by  hydrocyanic  acid.  Moreover,  very  fiuely 
divided  platinum,  osmium,  iridium,  or  silver  briug  about  the  inversion 
of  cane-suK^ar  at  elevated  teraperatnres. 

Whatever  nniy  be  the  nature  of  the  enzymes,  whether  they  are  def- 
inite and  distinct  chemical  individuals,  or  peculiar  physical  conditions 
of  certain  well -defined  substances  which  are  inert  in  tliis  regard  under 
other  conditions,  it  is  certain  that  soluble  products  are  obtainable  from 
certain  cells  which  are  capable  of  being:  conceotrated  to  a  certain 
degree,  although  not  as  yet  separable  iu  a  pure  form,  and  which  exert 
powerful  and  well-deiined  actions.  It  is  therefore  eouvenieut,  pro- 
visionally at  all  events,  to  speak  of  these  substances  as  if  they  were 
definite  entities.  There  seems,  however,  to  exist  a  tendency  to  abuse 
the  privilege  of  this  rather  easy  method  of  explaining  chemical  actions 
observed  in  living  beings,  and  to  immediately  name  a  new  enzyme  as 
the  cause  of  any  unexplained  or  newly  discovered  decomposition. 

In  naming  an  enzyme,  tbe  rule  is  adhered  to  as  far  as  possible  of 
giving  it  tije  name  of  tije  substance  w^hich  it  acts  upon,  modified  by 
changing  the  termination  to  me;  as  amylase,  raaltase,  urease,  etc. 
To  this  rule  we  have,  however,  exceptions,  such  as  pepsin,  amylopsiu, 
emulsin,  etc. 

The  enzymes  are  classified  according  to  the  nature  of  their  actions 
and  that  of  the  substances  acted  upon: 

1.  Amiflolifdr  enziftnes — which  hydrolyse  starch  through  the  stages 
of  aniylodextrin,  erythrodoxtrins,  and  aehroodextrins  to  maltose,  an 
aetitm  frequently  referred  to  as  diastatic.  These  enzymes  are  widely 
distributed  in  nature.  Prominent  among  them  are  the  amylase,  or 
diastase  produced  dnringr  the  germinatioji  t>f  grain,  and  the  diastatic 
enzymes  of  tlie  saliva  and  pancreatic  secretion.  In  this  class  are  also 
included  enzymes  which  hydrolyse  carbohydrates  more  or  less  closely 
nllied  to  starch:  the  hepatic  enzyme  which  converts  glycogen  into 
glucose,  ccllulasc,  whi^di  bydrolyscs  cellulose,  inulase,  which  converts 
innlin  into  fructose,  et»\ 

2.  Inrerinsfs — which  hydrolyse  disactdiarids,  or  the  trisaccharid 
raffinose,  to  their  constituent  monosaccharids.  They  are  sucrase, 
maltase  nnd  lactase.  Tnvertitig  enzymes  arc  not  active  in  the  salivary, 
gastric  or  paniTcatic  scrretions,  but  are  iu  the  intestinal  juice. 

3.  IJpoJffiir  fnzifmeji  —  which  saponify  fats  to  fatty  arids  and 
glycerol.  Lipases  exist  in  many  vegetables,  Rtriints,  PfijMv*t\  hemp 
seeds,  maize,  riKudd  fungi ,  etc.,  nnd  in  the  gastric  and  i>ani"rcatic 
accretions. 

4.  Profpobffie  fuztfrnts — whirdi  cause  the  hydroiytic  decomposition 
of  albumins  to  albumoses,  peptones^  and  simpler  compounds.     They 


606 


MANUAL    OF    CHEMISTRY 


include  pepsin*  trypsin,  the  papayotin  of  Carka  papaya^  and  the  auto* 
lytic  enzymes  which  exist  in  various  organs  and  cause  their  aseptic 
autolytie  digestion  after  death. 

5.  Glurosid- if  putting  euzymes — such  as  cmulsin,  which  bydrolyses 
amygdalin  to  glucose,  benzoic  aldehyde  and  hydrocyanic  acid»  and 
myrosin,  which  splits  potassium  rayronate  to  glucose,  allyl  isothio- 
cyanate  and  potassium  sulfate. 

6.  Oxidmes — ^which  cause  oxidations.  The  best  kuown  of  these  is 
laccase,  which  causes  the  oxidation  of  laccol,  an  oily  liquid  possessed 
of  poisonous  qualities,  obtained  from  the  Japanese  lac  tree,  to  a  hard, 
brilliant,  black  pigment.  Laccase  also  occurs  in  raany  other  plants; 
beets,  carrots,  potatoes,  asparagus,  grasses,  apples,  etc.  It  also 
oxidizes  aromatic  compounds  containing  two  0H»  or  an  OH  and  an 
NH2  group  in  ortlio  or  para  positions.  Thus  it  converts  hydroquinone 
and  para-amidophenol  into  qui  none.  Tyrosinase,  which  also  occurs 
in  many  plants,  heets,  potatoes,  dahlia,  fungi,  etc.,  causes  oxidation 
of  tyrosin  with  formation  of  red  and  black  derivatives,  and  also 
oxidizes  other  phenolic  compounds.  Laccase  has  no  action  upon 
tyrosin.  Oenoxydasc,  which  causes  the  oxidation  and  precipitatiou 
of  the  coloring  matters  of  French  and  Italian  wines.  Numerous  other 
oxidases  have  been  named  as  the  causes  of  oxidations  occurring  in 
animal  V>ndies;  although  their  existence  cannot  be  said  to  have  been 
demonstrated.  Such  are  the  glycolytic  enzymes  said  to  cause  the 
oxidation  of  glucose  in  the  liver  and  blood,  oxidases  in  the  liver  and 
splet*n  causing  oxidation  of  xanthiu  and  hypoxantbin  to  uric  acid. 
others  oxidizing  benzoic  and  salicylic  aldehydes  to  the  corresponding 
acids,  still  others  oxidizing  the  tartrates,  citrates  and  nialates  to  car- 
bonates, etc. 

7.  Coagnhiting  enzymes — ^ which  bring  about  the  formation  of  fil>rin 
and  of  myogen  and  myosin  fibrin,  and  the  coagulation  of  casein. 

8.  Ureases — which  cause  the  hydrolysis  of  urea  to  carbon  dioxid 
and  ammonia,  are  produced  by  3fr(?r(?rr>cri^5  urea\  B<teffrinm  urete,  Bncih 
his  flffcrfscfiis,  and  nmnerons  other  bacteria.  Micrororcns  urtd  also 
causes  the  hydrolysis  of  hippuric  acid  to  glycocoll  and  benzoic  acid. 

Numerous  other  enzymes  have  been  named  as  causing  decomposi- 
tion of  nucleic  acids,  the  conversion  of  cystin  into  taurin,  the  con- 
version of  amido  acids  to  araids,  the  dcamidation  of  guanin  and 
ad  en  in,  etc.,  etc. 

DIGESTION. 

SALIVA. 

The  saliva  is  a  mixture  of  the  secretions  of  several  glands:  The 
submaxillary  saliva,  which  may  be  obtained  by  inserting  a  cannla  in 
Wharton's  duct,  is  a  clear,  thin,  colorless,  slightly  viscid,  frothy* 


4 


i 


i 


SAUVA 


alkaline  liquid;  sp,  gr,  1002  to  1003;  containing  3.6  to  4.5  p/m  of 
solids.  These  solids  consist  of  mucin,  a  trace  of  albunjiii»  a  diastatic 
enzyine,KCl,NaCl,Na2HP04.Mg2H2CPO^)2.NaHC03,CaH2(COa)2,  and 
KCNS.  In  the  dog,  the  saliva  obtained  .by  nerve -excitation  differs 
according  to  the  nerve  supply  which  is  irritated:  the  chorda  tympani, 
or  cerebral  saliva  contains  12  to  14  p/ra  of  solids ;  sp.  gv.  1(X^4  to 
1005.6;  is  more  abundant  and  contains  less  mucin  than  the  sympa- 
thetic saliva*  which  contains  16  to  28  p/m  of  solids;  sp*  gr.  1007.5  to 
1018. 

The  sublingual  saliva  is  clear,  viscid,  alkaline,  and  contains 
mucin,  a  diastatic  enzyme  and  potassium  thioeyanate. 

The  parotid  saliva,  which  may  be  obtained  by  a  canula  inserted 
into  Steno's  duct,  is  a  thin  liquid,  usually  alkaline,  bnt  sometimes 
neutral,  or  even  faintly  acid^  sp.  gr.  1003  to  1012.  It  contains  5  to 
16  p/m  of  solids,  among  which  are  a  small  quantity  of  albumin  and 
a  diastatic  enzyme,  but  no  mucin.  Potassium  thioeyanate  is  some- 
times  present. 

Mixed  saliva  consists  of  the  above,  plus  the  secretions  of  the 
mucous  glands.  It  is  colorless,  tasteless,  odorless,  opalescent,  frothy, 
slightly  viscid;  and  cloudy  fi*om  the  presence  of  epithelium,  mucus 
corpuscles,  leptothrix,  and  food  particles.  On  exposure  to  air  it  be- 
comes more  cloudy  and  covered  by  a  pellicle,  which  consists  of  calcinm 
carbonate.  Its  reaction  is  alkaline,  the  average  alkalinity  being  equal 
to  0.8  p/m  of  Na2C03,  and  diminishing,  sometimes  to  acidity,  after 
meals.  Sp.  gr.  1002  to  1008.  It  contains  5  to  10  p/m  of  solids,  of 
which  the  organic  constituents  are  albumin,  mucin,  urea,  thioeyanate, 
and  two  enzymes,  ptyalin  and  maltase.  According  to  an  analysis  of 
Haramerbacher,  it  has  the  composition  :  Water:  994,2;  mucus  and 
epithelium:  2.2;  soluble  organic  constituents:  1.4;  thioeyanate:  0.04; 
salts:  2.2.  The  composition  of  the  ash  in  1,000  parts  is:  K20-457.2; 
Na30-95.9  ;  CaO  and  traces  of  Pe2O3-5O.ll  ;  MgO-1.55;  SO3-63.8  ; 
P2O5-I88.48  ;   CF183.52. 

Saliva  enz3mics. —  The  saliva  contains  two  enzymes:  one  amylo- 
lytic,  converting  hydrated  stanch  into  maltose  and  iso- maltose  (p. 
319),  which  exists  in  human  saliva  at  all  ages,  but  not  in  the  saliva 
of  the  carnivora,  known  as  ptyalin.  The  other  maltase,  present  in  the 
saliva  in  small  amount  only,  which  converts  maltose  into  glucose. 
Ptyaliu  has  not  been  obtained  in  a  condition  of  purity.  Gautier's 
method  gives  the  product  most  nearly  approaching  purity:  the  saliva 
is  treated  with  a  large  quantity  of  strong  alcohol ;  the  precipitate  is 
collected  and  redissolved  in  water;  albumins  are  precipitated  by 
mercuric  chlorid  and  separated  by  filtration;  the  excess  of  mercury 
is  removed  by  hydrogen  sulfid;  the  salts  are  removed  by  dialysis; 
and  the  ptyalin  again  precipitated  by  alcohol. 


608  MANUAL    OP    CHEMISTRY 

The  activity  of  the  amylolytic  action  of  saliva  is  directly  pro- 
portionate to  the  quantity  of  the  enzymes  present.  The  most  tayo^ 
able  reaction  is  a  very  faintly  acid  one,  due  to  carbonic  acid,  and 
the  activity  is  diminished  by  either  an  alkaline  reaction  or  an  add 
one  due  to  mineral  acids.  The  action  is  completely  arrested  by  the 
presence  of  0.03  p/m  of  HCl.  The  most  favorable  temperature  is 
40°  (104°  F.).  The  accumulation  of  its  products  interferes  with  the 
continuance  of  the  action,  and  it  is  therefore  more  rapid  and  exten- 
sive when  it  takes  place  in  a  dialyser  than  when  it  occurs  in  a  glass 
vessel.  On  the  other  hand,  it  is  favored  by  the  presence  of  peptones. 
The  presence  of  0.05  p/m  of  HgClo  arrests  the  action,  and  a  like 
result  is  produced  by  5  p/ra  of  MgS04,  while  0.25  p/m  of  the  latter 
salt  favors  the  action. 

The  total  quantity  of  saliva  secreted  in  24  hours  has  not  been 
directly  determined  in  the  human  subject.  It  is  estimated  at  from 
600  to  1,500  cc.  During  mastication  1  gram  of  salivary  gland  pro- 
duces 13  grams  of  saliva  per  hour.  The  quantity  is  increased  by 
pilocarpin  and  by  eserin,  and  diminished  by  atropin.  Many  metallic 
salts  are  eliminated  by  the  saliva,  e.  g.,  those  of  mercury  and  po- 
tassium, and  the  bromids  and  iodids;  others  do  not  appear  in  the 
saliva,  e.  g.,  the  salts  of  iron.  The  quantity  is  pathologically  in- 
creased in  poisoning  by  the  soluble  mercurials,  the  mineral  acids  and 
alkalies;  in  neurotic  conditions,  and  in  inflammatory  diseases  of  the 
mouth.  It  is  diminished  in  febrile  diseases,  in  diabetes,  sometimes 
iu  nephritis,  and  under  violent  psychic  emotions.  In  diabetes  the 
saliva  contains  sugar  in  about  54  per  cent  of  the  cases  examined. 

Salivary  calculi  are  rarely  met  with,  varying  in  size  from  mere 
granules  to  masses  weighing  18.6  grams.  They  consist  principally 
of  calcium  carbonate,  with  some  tricalcie  phosphate,  and  from  50  to 
368  p/m  of  organic  matter. 

GASTRIC    JUICE    AND    GASTRIC    DIGESTION. 

While  at  rest,  in  the  intervals  between  digestion,  the  stomach 
contains  only  a  thick,  slimy,  neutral,  or  even  alkaline  liquid,  the 
gastric  mucus,  or  succus  pyloricus,  so-called  because  it  is  the 
product  of  glands  located  principally  at  the  pj'loric  end.  The  trne 
gastric  juice  is  produced  only  during  digestion,  or  by  stimulation  of 
the  secreting  glands,  the  fundus,  or  pepsin  glands,  by  "chemical"  or 
^*psy(;hic"  action.  The  gastric  juice  of  man  has  been  obtained  free 
from  saliva  iu  one  case  only,  that  of  a  boy  of  five  years  having  an 
oesophageal  stricture  and  a  gastric  fistula  (Hornborg).  Mixed  with 
saliva,  it  has  been  obtained  iu  cases  of  traumatic  (Beaumont),  or 
surgical  (Richet)  gastrostomy.  From  animals  it  may  be  obtained  pure 
by  the  establishment  of  gastric  and  oesophageal  fistulae. 


OASTBIC    JUICE    AND    GASTRIC    DIGESTION 


609 


The  gastric  juice  is  a  elighUy  cloudy,  almost  eolorless  liriuiJ,  sp, 
gr.  1001  to  1010,  having  an  acid  tuf^te  and  a  strongly  acid  reaction. 
It  deposits  a  sediment,  whie:^h,  unmixed  with  food  particles,  contains 
gland  cells  and  nuclei,  mucus  corpuscles  and  altered  cylindrical 
epithelintii. 

[According  to  an  analysis  by  Schmidt  of  human  gastric  jnice, 
mixed  with  some  saliva,  it  contains:  Water  -90.44,  solids  -0.56,  free 
hydrochloric  acid,  0.25,  The  solids  consist  of :  organic  substances 
(pepsin,  etc.)  -0.32,  NaClH).14,  KCl-0.05,  CaCh -0.006.  phosphates 
of  Ca,  Mg,  and  Fe  -0,015.  Among  the  organic  constituents  are  a 
■  small  quantity  of  a  nucleoproteid,  a  mucin,  a  thiocyanate  and  albu- 
I  nose  (f),  and  two  or  possibly  three  enzymes,  pepsin,  pseudopcpsin 
I  and,  it  is  chiimed  by  some  and  deuied  by  others,  a  saponifying 
I    enzyme,  a  lipase, 

I  The  chief  function  of  the  stomach  is  to  serve  as  a  receptacle  in 

P    which  the  food  may  he  stored »  and  mixed  by  the  action  of  the  ninscu- 

lar  coats  of  the  organ,  both  orifices  being  closed  the  while  by  con- 

»  traction  of  the  sphincters.  In  the  stomach  the  proteins  nre  to  a 
considerable  ext-ent  converted  into  sobible  and  absorbable  products, 
but  neither  for  this  nor  for  other  use  is  the  stomach  an  essential  orgnn. 

I  The  solution  of  the  proteins  is  accomplished  more  thoroughly  and 
more  rapidly  by  tryptic  digestion  in  the  intestine,  which  in  fact  termi- 
nates the  process  begun  in  the  stomach,  but  not  completed  therein  iu 
the  tiujc  daring  which  the  food  remains  subject  to  gastric  action. 
Indeed  dogs,  after  ablation  of  the  stomach,  may  live  for  years  in  per- 
feet  nutrition  and  passing  normal  ffeees,  the  only  departure  from  the 
normal  in  them  being  that,  because  of  the  absence  of  the  receptacle, 
they  take  food  in  smaller  quantities  and  more  frequently,  and  that 
^Krith  time  the  intestine  becomes  dilated.  Another  function  of  the  gas- 
tric secretion,  claimed  by  some  to  be  its  most  important  utility,  is  the 
destruction  of  bacteria,  taken   in  with  the  food  and  drink,  by  the 

Jj^rermicidal  action  of  the  acid. 
It  is  now  established  that  the  free  acid  of  the  normal,  unmixed 
S^astric  juice  is  hydrochloric  acid.  During  digestion  lactic  acid  or 
l>utyric  or  acetic  acid  may  be  present.  They  are,  however,  not 
I>roducts  of  secretion,  but  are  derived  from  constituents  of  the  food. 
Tr*he  amount  of  hydrochloric  acid  present  varies  in  different  animals, 
^nd,  within  narrower  limits  in  the  same  animal  at  different  times. 
The  gastric  juice  of  the  dog  contains  from  2  to  6  p/m,  that  of  the  eat 
^tiout  5  p/m.-  The  proportion  usually  accepted  as  present  in  human 
Gastric  juice  is  2  to  3  p/ra;   but  in  Hornborg's  case  it  w^as  found  to 

t'^^ry  from  3.65  to  5.66  p/m,  the  mean  of  which  is  4MS  p/m. 
The  exact  mechanism  of  the  formation  of  the  gastric  hydrochloric 
^id  is  unknown.    That  it  is  derived  from  the  chlorids  of  the  blood 
30 


610 


MANUAL    OF    CHEMISTRY 


the     , 


is  most  probable,  although  it  ma}*  result  from  decomposition  of  chlo- 
rinated am  ids,  which  have  been  foiind  to  exist  in  g-land  tissues.  A 
fat^t  which  supports  the  supposition  of  the  derivation  from  the 
ehlorids  is  that  if  dogs  be  given  a  diet  from  which  chlorids 
exchided  the  hydrochloric  acid,  after  a  time,  ceases  to  be  forme* 
while  pepsin  continnes  to  be  secreted;  and  if  now  the  animal  be 
^iven  bromids,  iodids»  or  chlorids,  the  g^astrie  juice  will  contain 
hydrobromie,  hydriodict  or  hydrochloric  acid,  as  the  case  may  be. 
The  most  probable  supposition  with  regard  to  the  method  of  forma- 
tion of  the  acid  from  the  chlorids  is  that  it  is  produced  by  chemical 
action,  the  chlorids  being  decomposed  by  the  free  carbon  dioxid  (or 
carbonic  acid)  in  the  blood,  by  mass  action,  according  to  the  equation: 
2NaCl+0O2+H2O=Na2CO:,+2HCI;  or  it  may  be  the  result  of  de- 
composition of  calcium  chlorid  by  thedisodic  phosphate  of  the  blood: 
2Na2HP04+3CaCk=Ca:,(P04)2+2HCl+4NaCL  The  former  reaction 
is  the  more  probable,  because  of  the  generation  of  alkali,  mentioned 
below,  during  stomach  digestion.  The  reaction:  2NaCH-C02+H2- 
O^^Na2COa+2HCl  implies  the  formation  of  a  quantity  of  alkali 
equivalent  to  the  amount  of  acid  generated,  which  should  manifest 
itself  somewhere  in  the  system  to  a  degree  proportionate  to  the  quan- 
tity of  acid  formed  at  different  times*  It  is  supposed  that  the  alkali 
thus  produced  enters  into  combination  with  the  lecithalbumins  which 
exist  in  gland  cells.  Whether  this  is  the  ease  or  not,  it  is  knowa 
that  the  acidity  of  the  urine  varies  inversely  with  the  activity  of 
hydrochloric  acid  formation;  and  that  the  urine  may  even  become 
alkaline  during  the  greatest  activity  of  stomach  digestion  and  in 
hyperchlorhydria. 

Pepsin  and  Pepsi  no  gen,*"  Pepsin  exists  in  the  gastric  juiee  ot 
all  vertebrates,  and  at  all  ages,  except  that  it  is  not  secreted  by  sod- 
ling  pigs  or  puppies.  It  has  not  been  obtained  in  a  condition  ot 
purity,  the  nearest  approach  thereto  being  the  product  of  Peckel- 
liaring's  method:  The  gastric  juice,  collected  from  dogs  having 
cesophageal  and  gastric  fistula?,  is  filtered  and  dialysed  at  near  0  for 
20  hours.  The  precipitate  formed  is  collected  by  the  centrifuge  and 
nitration,  washed  with  water  and  dried  over  H28O4.  A  further  portion 
is  obtained  by  precipitation  by  half  saturation  with  ammonium  sul- 
fate, and  removal  of  salt  by  dialysis.  The  united  pi*ecipitate5  are 
dissolved  in  0.2  per  cent  HCl,  reprecipitated  by  dialysis  and  dried  over 
H2SO4.  A  less  pure  prodtict  is  obtained  by  Bnicke's  method:  Tb^ 
mncouR  membrane  is  extracted  with  water  containing  phosphoric acio; 
the  filtered  extract  is  treated  with  lime  water;  the  precipitate  f^' 
tricalcic  phosphate  containing  the  pepsin,  which  it  carries  doi^ 
mechanically,  is  dissolved  in  dilute  hydrochloric  acid,  and  the  solution 
freed  from  salts  by  dialysis.    For  digestion  experiments  an  eitrfif* 


GASTRIC   JUICE    AND    GASTEIC    DIGESTION 


611 


I 


I 


I 


made  by  maceratiug  the  uuieous  nieujbraue  in  glycerol  contain iug 
1  p/m  of  HCl  aud  filtered  after  8-14  tlays»  may  be  used.  Pepsin  is 
soluble  in  water  and  in  glycerol,  from  which  it  may  be  precipitated 
by  aleohoL  It  does  not  give  the  albumio  reactions.  It  is  precipitated 
by  half  saturation  with  ammonium  sulfate.  It  does  not  dialyse.  In 
aqueous  solution  its  activity  is  rapidly  destroyed  by  boiliug,  more 
glowly  in  ueutral  solution  at  55°,  iu  acid  solution  at  65"^,  at  70"^  in 
pi-esenee  of  peptones,  and  quite  rapidly  even  at  38^0°  in  presence  of 
ver>'  small  quantities  of  alkaline  carbonates.  When  dry  it  may  be 
heated  to  100°  without  deroui position.  The  characteristic  property  of 
pepsin  is  that  it  dissolves  albumins,  with  formation  of  albumoses  and 
peptones,  in  acid,  but  not  in  ueutral  or  alkaline  solutions. 

Pepsinogen,  or  propepsin,  is  the  zymogen  from  which  pepsin  is 
formed  by  contact  with  hydrochloric  acid,  and  is  probably  produced 
by  the  chief  cells  of  the  fundus  glands.  The  raucous  membrane  of 
the  fasting  stomaeb  yields  to  dilute  hydrochloric  acid  an  actively 
digesting  extract,  e\^en  after  treatment  with  1  %  sodium  carbonate 
soUitioD,  at  40^,  which  very  rapidly  destroys  the  activity  of  pepsin, 
but  acts  only  very  slowly  upon  pepsinogen.  It  has  been  supposed 
that  pepsinogen  and  hydi'ochloric  acid  combine  chemically  together 
to  form  a  definite  compound,  the  active  material  of  the  gastric  juice, 
which  has  been  called  pepsohydrochloric  acid. 

As  has  been  stated  above,  the  characteristic  reaction  of  pepsin  is 
its  power  of  dissolving  albumins  in  acid  solution.  If  a  fragment  of 
coagulated  white  of  egg  be  immersed  in  HCl  of  2-4  p/m  at  40'^  it  is 
nat  affected,  but  if  a  trace  of  pepsin  be  also  present,  the  edges  of  the 
fragment  are  soon  rounded,  and  the  material  becomes  transparent, 
and  finally  dissolves.  A  similar  effect  is  produced  more  rapidly  and 
at  a  lower  temperature  (20*^)  with  fibrin.  A  similar  action,  but 
slower,  occurs  with  acids  other  than  hydrochloric,  diluted  strong  acids 
acting  better  than  weak  acids.  Taking  the  digestive  power  of  pepsin 
with  HCl  as  1,000,  that  with  HNOa,  H28O4,  lactic,  acetic  and  butyric 
acids  is  932,  909,  603,  396  and  336  respectively.    While  hydrochloric 

Jacid  is  the  most  highly  dissociated  of  these  acids,  the  digestive  power 
*>f  the  other  acids  is  not  proportionate  to  their  electrical  conductivity, 
although  that  of  the  organic  acids  is  much  lower  than  that  of  the 
*»iceral  acids.  The  rapidity  of  the  action  is  also  affected  by  other 
couditions:  it  is  more  rapid  if  the  products  of  the  action  be  removed 
^y  dialysis  than  if  they  be  allowed  to  accumulate;  and  it  is  less 
'^pid  in  presence  of  salicylic  acid,  metallic  salts,  alkaloids,  phenol, 

.     **^lfate8,  or  of  alcohol  in  greater  proportion  than   10  per  cent.    The 

h  tnost  favorable  temperature  is  40*^,  and  the  most  advantageous  pro- 

B  T>ortion  of  HCl  about  2.5  p/m. 

^       Another  enzyme,  called  pseudo  pepsin,  is  secreted  at  the  pyloric 


I 


612 


MANTTAI.    GF    CHEMISTRY 


end  of  the  stomach,  and  probably  also  at  the  cardiac  end*    It  differs 

from  pepsiti  in  that  it  acts  not  only  in  an  acid  liquid  but  also  iu  one 
which  is  faintly  alkaline,  and  in  that  it  produces^  tryptophane  as  ou^_ 
of  the  products  of  its  prolonged  action,  which  pepsin  does  not  do.      ^M 

The  conversion  of  albumin  into  peptone  is  by  no  means  a  simple 
process.  The  protein,  behaving  as  a  base,  first  enters  into  combination 
with  the  hydrocliloric  acid,  to  form  an  acid  albnminate.  The  amount 
of  acid  so  combined  with  the  protein  is  from  5  to  15  per  cent  of  the 
weight  of  the  latter,  the  proportion  being  smaller  with  the  native 
albumins  and  greater  with  their  products  of  hydrolysis,  which,  it  may 
be  assumed,  contain  a  greater  number  of  basic  hydroxyls.  The  acid  in 
combination  in  acid  albuminates  and  with  albnmoses  is  referred  to  as 
'Mooscly  combined,"  or  -^protein  "  hydrochloric  acid.  The  acid  albumin 
then  undergoes  gradual  cleavage,  producing  numerous  products  of 
progressively  diminishing  molecular  weight,  diminishing  proportion- 
ate carbon  content  (because  of  the  addition  of  water  in  hydrolysis 
and.  iuereasiug  diffusibility  as  the  decomfjosition  advaiices  througl 
the  album oses,  until  the  final  products,  the  peptones,  are  reached.  The 
formation  of  acid  albumiiuites  as  an  intermediate  stage  in  the  trans; 
formation  of  native  or  coagulated  proteins  into  albumoses  is,  boweve: 
not  essential,  and,  while  acid  albnmiuates  do  not  occur  iu  the  stomach 
in  complete  absence  of  albumoses,  the  latter  may  be  present  when  no 
acid  albnininate  can  be  detected.  Tins  may  be  due  either  to  the  eon* 
version  of  acid  albuminate  into  albumose  immediately  upon  its  frn 
mation,  or  to  its  non -formation.  The  latter  view  is  more  probabi, 
the  true  one,  as  the  transformation  of  acid  albuminate  into  albumose 
does  not  occur  rapidly.  It  is  also  claimed  that  acid  albuminates  aoJ 
primary  albumoses  may  be  formed  together  as  split  products  of  tbe 
parent  protein,  that,  in  other  words,  acid  albuminates  are  parallel 
products  with  the  primary  albumoses. 

In  the  several  stages  of  hydrolytic  decomposition  it  becomes  evident 
that  the  protein  molecule  contains  two  uusymmetrical  fractions  which 
behave  differently  towards  proteolytic  enzymes  and  other  solvents. 
One  of  tliese  readily  hydrolyses  to  soluble  products,  while  the  other 
resists  the  action  of  enzymes  and  acids  much  more  olistinately,  Th^ 
more  readily  soluble  fraction  is  designated  as  the  henii  groupi  ^^^ 
more  resistant  as  the  anti  group.  On  decomposition  the  anti  com^ 
pounds  yield  larger  quantities  of  diamido  acids  than  do  those  of  ^® 
hemi  group. 

Intermediate  between  the  acid  albuminates  and  the  peptones  a 
series  of  substances,  called  albumoses  or  propeptones,  are  fornJ^* 
Prom  the  different  pi-oteins  different  allninKiscs  are  derived.  Tli^ 
proteoses  are  derived  from  the  true  albumins  and  from  the  alboW''" 
components  of  the  proteids;  the  gelati noses «  Iceratinoses,  etc  fr^'ii 


GASTRIC    JUICE    AND    GASTRIC    DIGESTION 


I 


the  albimimoids.  It  is  also  highly  probable  that  each  species  of 
albatDin  furnishes  an  individual  series  of  proteose.  These  are  desig- 
nated as  globulinoses,  vitellinosesi  fibrinoses,  caseinoseS)  etc., 
according  to  their  origin. 

All  albnmoses,  except  heteroalbumose,  are  soluble  in  water,  all 
are  soluble  in  hydrochlorie  acid  aschlorkls,  whose  solutions  are  highly 
dissoeiated.  They  are  precipitated  by  potassium  ferroeyauid  and 
acetic  acid,  by  nitric  acid  either  in  watery  solution  or  in  solutions 
saturated  with  sodium  chlorid,  and  by  phosphotungstic  acid  and  other 
alkaloid  reagents,  the  precipitates  in  all  cases  being  dissolved  by  heat 
and  reappearing  ou  cooling.     They  all  give  the  xanthoproteic  and 

■  Adamkiewncz  reactions,  and  a  red  color  with  the  biuret  reaction^  ex- 
^U0pt  protoalbumose,  which  gives  a  violet.  The  best  studied  of  the 
^Pilbtimoses  are  tlie  fibri noses,  which  are  conveniently  obtained  from 

■*Witte*s  peptone,"  a  product  of  artificial  peptic  digestion  of  fibrin, 
which  contains  very  little  true  peptone,  and  consists  chiefly  of  fibri- 
Doses  with  some  mucinoses. 

»The  first  dissolved  products  derived  from  the  iund  albumins,  or 
formed  directly  from  the  albumins,  are  known  as  primary  albumoses. 
They  are  of   three  kinds:    protoalbumose,  derived    from    the    liemi 
group,  and  heteroalbumose  and  glucoalbumose  from  the  anti  group. 
The  heteroalbumoses  are  the  albumoses  most  nearly  related    to  the 
native  albumins.     Besides  these  albumoses  there  is  produced  at  this 
stage  an  insoluble  residue  of  antialbumid,  which  is  difficultly  soluble, 
even   by  tryptic   digestion.     Glucoalbumose    differs    from   the  other 
primary  albumoses  in  the  important  respects  that  it  contains  a  car* 
bohydrate  component  and  therefore  responds  to  the  Molisch  reaction, 
Trhicb  the  others  do  not^  and  that  it  is  not  salted  out  frotn  neutral 
Eolation  by  one -half  saturation  with  ammonium  sulfate,  but  only  by 
complete  saturation  witli  that  salt.    It  is,  however,  classed  as  a  primary 
nlbumose,  being  a  direct  derivative  of   the  acid  albumin  or  native 
albumin.     Heteroalbumose  and  protoatbumose   differ   from   the  sue- 
oeeding  products,  the  secondary  albumoses,  principally  in  being  less 
cJiffusible,  and  in   their  behavior  towards  nitric  acid,  and    towards 
ammonium  sulfate.    Nitric  acid  in  the  cold  precipitates  these  primary 
albumoses  from  simple  aqueous  solution,  but  the  secondary  albunmses 
only  in  the  presence  of  salts,  if  at  all.    Ammonium  sulfate  precipitates 
these  primary  albumoses  completely  when  added  to  half  saturation, 
l>ut  the  secondary  albumoses  are  only  precipitated  by  greater  com^en- 
B  tration  of  the  salt,  up  to  saturation  in  some  cases.     Both  heteroal- 

■  bqmoses  and  protoalbumoses  are  salted  out  by  sodium  chlorid,  the 
tormer  from  neutral  soltitiou,  the  latter  only  in  presence  of  acid.  The 
Uiniti;  of  each  with  ammonium  sulfate  are  2.6  and  4.4  in  neutral  soln- 

d  1.2  and  4.3  in  acid  solution*     They  form  precipitates  with 


614  MANUAL    OF    CHEMISTRY 

cupric  sulfate  or  acetate,  and  with  protamins  and  histons.    They  con- 
tain no  carbohydrate  component. 

Heteroalbumose  (from  fibrin)  is  very  sparingly  soluble  in  water, 
easily  soluble  in  hydrochloric  acid,  and  partly  precipitable  from  this 
solution  by  dilution;  soluble  in  alkalies;  and  does  not  dialyse  from 
neutral  solutions,  and  only  very  slightly  from  those  which  are  alkaline. 
It  is  partly  coagulated  at  55°-60®  in  presence  of  small  qaantities  of 
salts.  The  coagulum  is  soluble  by  increased  heat,  and  in  its  own  form 
in  dilute  hydrochloric  acid  or  caustic  soda;  it  is  not  denatnrized.  It 
is  salted  out  completely  from  acid  solutions  by  half  saturation  with 
sodium  chlorid.  It  is  precipitated  by  alcohol  at  a  concentration  of  32 
per  cent  alcohol,  a  property  which  is  utilized  for  its  separation  from 
protoalbumose,  which  is  still  soluble  in  alcohol  of  80  per  cent.  On 
decomposition  it  yields  6.45  per  cent  of  its  nitrogen  as  ammonia, 
57.40  per  cent  as  monamido  nitrogen,  and  38.93  per  cent  as  diamido 
nitrogen.  Among  its  decomposition  products  are  lencin  and  glycocoU 
in  large  amount,  but  only  traces  of  tyrosin,  and  no  indole  or  skatole. 
It,  however,  contains  an  aromatic  complex,  probably  phenylalanin. 
On  further  peptic  or  tryptic  digestion  it  produces  deuteroalbnmoses  A 
and  B  and  traces  of  C,  and  peptone  B. 

Protoalbumose  (from  fibrin)  is  very  easily  soluble  in  water,  and 
dialyses  more  than  heteroalbumose.  It  is  only  salted  ont  by  sodium 
chlorid  on  complete  saturation  in  acid  solution.  It  is  soluble  in  80 
per  cent  alcohol.  It  is  not  coagulated  by  heat.  The  precipitates  which 
it  forms  with  tannin  and  other  alkaloid  reagents  are  soluble  in  excess 
of  the  precipitant.  On  decomposition  it  yields  7.14  per  cent  of  its 
nitrogen  as  ammonia,  68.17  per  cent  as  monamido  nitrogen,  and  24.42 
per  cent  as  diamido  nitrogen.  Among  its  decomposition  products  are 
little  leucin,  no  glycocoll,  but  much  tyrosin,  tryptophane,  indole  and 
skatole.  On  further  peptic  or  tryptic  digestion  it  produces  ranch 
deuteroalbumose  A  and  peptone  B,  but  no  deuteroalbumose  C  or 
peptone  A. 

Glucoalbumose,  also  known  as  deuteroalbumose  ^,  denieroal 
bumose  BIT,  and  synalbumose,  is  not  precipitated  from  neutral  solu- 
tion, along  with  the  other  primary  albumoses,  by  50  per  cent  satn- 
ration  with  ammonium  sulfate,  but  only  by  complete  (95  per  cent) 
saturation,  along  with  some  of  the  secondary  albumoses,  in  deutero 
fraction  B  (below),  from  which  it  is  separable  by  alcohol,  which  first 
precipitates  out  deuteroalbumose  BI  at  35  per  cent,  and  then  glucoal- 
bumose at  60-70  per  cent,  leaving  the  other  deuteroalbumoses  in  solu- 
tion. It  is  the  only  albumose  containing  a  carbohydrate  component, 
and  the  sole  precursor  of  peptone  A.  It  not  only  gives  a  brilliant 
Molisch  reaction,  but  an  osazone,  f.  p.  182°-185*^,  has  been  obtained 
from  it.     It  contains  but  little  loosely  combined  sulfur. 


GASTKIC    JUICE    AKD    GASTRIC    DIGESTION 


615 


Ao  albumose  obtained  from  Witters  peptone,  known  as  deuteroal^ 
bumose  A^,  is  also  probably  a  primary  product.  It  is  precipitated 
from  neutral  solution  by  sodium  eblorid  and  by  copper  salts.  Its 
limits  with  ammonium  sulfate  are  4  and  5.6. 

The  primary  albumoses  on  further  peptic  digestion  yield  secondary 
albumoses,  also  called  deutcroalbamoscs,  which  are  soluble  in  water 
and  diffuse  more  ihnn  the  primary  albumoses,  but  less  than  the  pep- 
tones. They  give  the  xanthoproteic  aud  biuret  reactions  and,  except 
deuteroalbumose  C,  the  Millon  reaction.  Exceptini:  glucoal bumose, 
they  contain  no  carbohydrate  component  and  therefore  do  not  give  the 
Molisch  reaction.  They  are  not  precipitated  by  copper  salts.  They 
are  only  precipitated  by  nitric  acid  in  presence  of  salts,  if  at  all.  They 
are  not  salted  out  by  50  per  cent  saturation  with  ammonium  sulfate  in 
neutral  solution,  but  on  increasing  the  concentration,  aud  finally 
acidulating,  they  are  divided  into  three  "fractions,"  which  are  them- 
selves mixtures,  except  probably  the  last. 

Deutero  fraction  A^  derived  chiefly  from  the  hemi  ir>*oup,  but  also 
from  the  anti  group,  is  precipitated  from  neutral  solution  by  62  per 
cent  saturation  with  ammonium  sulfate.  Its  limits  with  this  salt  are 
5.4  and  6.2  in  neutral  solutiou,  and  4.7  and  5.9  in  acid  solution.  On 
treatment  with  70  per  cent  alcohol  this  fraction  is  divided  into  two 
parts:  deuteroalbymose  A,  which  goes  into  solution,  and  thioal- 
bumose,  which  remains  insoluble.  The  former  contains  0.8  per  cent 
sulfur,  and  the  latter  2.97  per  cent,  of  which  the  major  part  is  in  the 
loosely  combined  condition. 

Deutero  fniction  II,  derived  almost  entirely  from  the  anti  group,  but 
also  from  the  hemi  group,  is  precipitated  from  nentral  solution  by  95 
per  cent  saturation  with  ammonium  sulfate.  Its  limits  with  that  salt 
are  7.2  aud  9.5  in  neutral  solution,  and  6.3  and  7.7  in  acid  solution. 
By  alcohol  this  fraction  is  divided  into  three  parts.  One,  deutero* 
albumose  B  I,  insoluble  in  35  per  cent  alcohol,  constitutes  the  major 
part  of  the  secondary  albumoses  from  fibrin.  It  contains  no  loosely 
combined  sulfur.  The  second  part  is  glucoalbumose,  or  deoteroal- 
butnose  B  II,  which  is  precipitated  by  alcohol  at  60-70  per  cent.  The 
third  part,  which  is  still  soluble  in  alcohol  at  80-90  per  cent,  is  itself 
a  mixture  containing  two  albumoses,  deuteroalbumose  B  Ills 
deuteroalbumose  B  III^,  both  of  which  give  the  xanthoproteic, 
biuret  and  Millon  reactions,  but  not  the  Molisch,  and  a  raelanoidin- 
like  substauce,  peptomelanin,  which  gives  none  of  these  reactions. 

Deuteroalbumose  C»  derived  in  small  quantity  and  entirely  from 
the  anti  group  in  the  case  of  fibrin,  is  only  precipitated  by  ammonium 
sulfate  at  complete  saturation  and  acidulation  with  sulfuric  acid  satu- 
rated with  that  salt.  It  is  soluble  in  60-70  per  cent  alcohol.  It  appears 
to  contain  no  sulfur.    It  gives  the  xanthoproteic  and  biuret  reactions, 


616 


MANUAL    OF    CHEMISTRY 


but  not  the  Molis«h.  It  yields  neither  indole  nor  skatole  an  decompo- 
sition.  It  produces  no  peptone,  and  appears  to  be  intermediate  between 
those  substances  and  the  other  albumoses  in  eoustitution» 

The  formation  of  albumoses  iti  peptic  digestion  at  the  body  temper- 
ature begins  quite  soon.  With  serum  albutnin  primary  albumoses  and 
acid  albuminates  begin  to  be  formed  in  leiss  tlmn  nine  minutes,  and  in 
26  minutes  with  egg  albumin  the  solution  contains  not  only  hetero- 
and  protoalbumose,  but  also  deuteroalbumose  B.  In  this  early  stage^ 
and  during  the  formation  of  primary  albumoses,  other  products  are 
split  off,  in  small  quantity  at  first,  but  increasing  to  a  proportion 
which  subsequently  remains  constant,  which  are  much  simpler  in  con- 
stitution than  the  albumoses.  These  products,  which  are  formed  more 
abundantly  towards  the  final  stages  of  prolonged  peptic  and  try^ptic 
digestion,  are  called  peptoids  (p.  617} . 

In  the  period  during  which  the  food  remains  in  the  stomach,  usually 
about  four  hours,  the  secondary  and  even  the  primary  albumoses 
formed  are  to  some  extent  absorbed*  although  their  absorption  is  much 
more  difficult  than  that  of  the  peptones.  In  this  time  peptic  digestion 
proceeds  only  to  the  formation  of  secondary  albumoses  and  peptoids. 
Peptones  are  either  not  formed  or  are  only  produced  in  very  small 
amount.  But  by  prolonged  peptic  digestion  at  the  body  temperature 
in  v'lfro  not  only  are  peptones  produced »  but  the  decomposition  proceeds 
still  further,  and  the  final  products  are  qualitatively  the  same  as  those 
formed  by  the  more  energetic  trj^ptic  digestion,  except  that  tryptophane 
is  not  produced. 

The  name  peptone  is  now  applied  to  all  products  of  decomposition 
of  proteins  which  cannot  be  salted  out,  either  from  acid,  neutral  or 
alkaline  reaction,  by  ammonium  sulfate  or  other  salts,  and  which  give 
the  biuret  reaction,  whatever  may  be  their  chemical  nature.  Among 
them  are  compounds  which  are  extremely  soluble  in  water,  hygroscopic, 
crystallizable,  highly  diffusible,  are  not  precipitated  by  nitric  acid  evea 
from  solutions  saturated  with  salts,  nor  by  the  usual  precipitants  of  the 
albumins  except  phosphotungstic  aud  phosphomolybdic  acids,  mercuric 
chlorid,  tannin,  picric  acid  and  alcohol.  With  the  biuret  reaction  tbey 
give  a  distinct  red  color. 

The  mixture  of  peptones  resulting  from  peptic  digestion  was  for- 
merly  considered  as  an  individual  substance,  known  as  Kut^hne's 
amphopcptone,  from  its  origin  from  both  hemi  aud  auti  groups.  The 
deuteroalbnraoses  A  and  B  from  fibrin  yield  peptones,  deuteroalburaose 
C  does  not.  The  product  from  deuteroalbumoses  A,  BI,  and  Bill, 
undoubtedly  a  mixture,  is  known  as  peptone  B*  It  is  soluble  in  96 
per  cent  alcohol,  gives  the  Milton  reaction »  is  not  precipitated  by 
iodopotassium  iodid  solution  in  saturated  ammonium  sulfate  solution, 
and  contains  no  carbohydrate  component,  and  therefore  does  not  give 


: 


JASTRIC    JUICE    AND    GASTRIC    DIGESTION 


617 


the  Moliscli  rt^aetioii.  Peptone  A,  derived  from  glucoalbumose  (deutero- 
aibuiaose  BII),  is  insoluble  in  96  per  ceut  aleoliol,  is  precipitated  by 
the  iodopotassic  solution,  contains  a  carbohydi*ate  compuneat,  and 
llfives  a  brilliant  Molisch  reaction. 

Probably  the  only  peptones  which  have  been  obtained  as  chemical 
individuals  are  the  fibrin  and  ^lutin  peptoues  of  Siegfried,  The  pcp- 
ain-ftbrin-pcptones,  ^,  C^iIiuNtiOo,  and  /3,  C2iH3eN(jOi0i  are  acids,  ca- 
pable of  expelling  CO2  from  carbonates  to  form  salts,  exert  constant 
IflBvoratation,  and  give  both  biuret  and  MiUon  reactions.  The  ^  pep- 
tone can  yield  the  o.  compound  by  loss  of  water.  They  are  amphopep- 
tones  in  the  meaning  of  Knehne  in  that  on  tryptic  dij^estion  they  yield 
antipeptones  (p*  629). 

The  peptoids  give  off  ammonia  when  heated  with  magnesia,  and 
are  the  near  precursors  of  the  end  products  of  tryptic  and  prolonged 
peptic  digestion.  They  are  distingnLshed  from  the  peptones  by  not 
giving  the  biuret  reaction.  The  polypeptids  {p.  415),  which  still  give 
the  biuret  reaction,  are  probably  intermediate  products  between  deu- 
I teroalbumoses  and  paptoids,  Arginiu  (p,  418),  and  albamin,  a 
dthexoseamin,  Ci2H2^Ni03,  are  among  the  decomposition  products  of 
the  peptoids.  By  still  longer  continued  peptic  digestion  the  follow- 
ing end  products  have  been  obtained:  amidovaleriauic  aeid»  leueiu, 
glutamic  and  aspartic  aeids»  lysin,  cystin,  pntresein,  eadaveriu,  ty rosin, 
pheaylalanin,  oxyphenylethylamiu,  and  skatosin. 

The  changes  above  described  may  be  expressed  for  the  fibrinoses 
in  the  tabular  form  of  the  scheme  on  p.  618. 

Peptic  digestion  exerts  the  following  actions  upon  substances 
other  than  the  native  albumins:  Milk  is  "curdled"  by  the  gastric 
juice,  a  change  which  consists  in  the  separation  of  the  ^*enrd^' 
(cheese)  and  "whey."  The  former  is  derived  from  the  nucleoalbnmiu 
casein,  which  exists  in  the  milk  as  its  soluble  neutral  tricalcic  salt. 
This  effect  has  been  ascribed  to  the  action  of  an  enzyme,  called  chy- 
mosin,  or  rennin,  derived  from  a  proenzym,  chymosinogcn,  supposed 
to  be  secreted  by  the  fundus  ghmds.  Cbymosin  has,  however,  not 
been  obtained  free  from  pepsin,  and  the  two  enzymes  are  in  all  likeli- 
hood one  and  the  same.  The  curdling  of  milk  is  merely  the  first  stage 
in  the  digestion  of  casein,  attended,  in  the  case  of  this  particular  pro- 
tein, by  the  separation  of  a  temporarily  insoluble  product.  The  calcium 
casein  is  split  into  a  small  quantity  of  an  albumose-like  protein, 
called  whey-albumin,  and  a  solul>le  calcium  paracasein,  which  latter, 
combining  with  soluble  calcium  salts,  produces  the  curd,  insoluble  in 
liquids  of  nearly  neutral  reaction.  The  paracasein  so  formed  is  itself 
a  nucleo*  album  in,  and  is  split  hy  further  peptic  digestion  into  its 
paranuclein,  which  remains  insolul>le,  and  its  albumin  component 
which  is  then  converted  into  primary  and  secondary  albumoses,  etc., 


618 


MANUAL    OP    CHEMISTRY 


Native  or  Coagulated  Albumins 
^  V  ^ 


I 


Primary  Albumoses. 
Pptd.  by  cold  HNO3  in 
H2O  8oln. ;  pptd.  by  CuSOi ; 
salted  out  by  X  satn. 
w.  (NH4)2SOi,  except 
glucoalbumose. 


Acid  albuminates 
V 


V 

I 

V 
Antialbumid. 

Insol.  by  peptic  diges- 
tion, difficultly  by  tryp- 
tic. 


V 
Peptaids. 

Give  off  NH3  w.  MgO  and 
heat.  Give  no  biuret  re  - 
action. 


ffemi  Group. 
Easily  sol.  by  enzTmes. 


V 

Anti  Oroup 

Difficultly  sol.  by  enzymes. 


Protoalhumoses, 
Very  sol.  H2O;  sol.  80% 
alcohol;  only  salted  out 
by  complete  satn.  w.  NaCl 
in  acid  soln.;  no  carbo- 
hydrate. 

Y 


I 

Y 
Glucoalbumoses . 
Sol.  H2O;  insol.  60 ?& 
alcohol ;  only  sal^^ed  out 
fr.  neutr.  soln.  by  95% 
satn.  w.  (N  114)2804; 
contain  carbohydrate. 

V 

I 

V 
Peptone  A. 

Insol.  96%  alcohol;  con- 
tains carbohydrate. 


Secondary  Albumoses.— "Sot  salted  out  by  50% 
satn.  w.  (NH4)2S04,  but  are  at  higher  cone; 
pptd.  by  HNO3  only  in  pres.  of  salts,  or  not  at  all; 
not  pptd.  CUSO4. 


Heteroalbumoses, 
Almo<tt  insol.  H20;  pptd. 
by  alcohol  32%;  salted 
fr.  acid  soln.  by  X  s^tn. 
w.  (NH4)2S04;  no  carbo- 
hydrate. 

V 


V  V 

Deutero  fraction  A. 
Pptd.  fr.  neutral  soln.  by 
62%  satn.  w.  (NH4)2S04. 

V 


I 

V 

Deutero  fraction  B. 
Pptd.  fr.  neutral  soln.  by 
95%     satn.    w.    (NH4)2- 
SO4. 

V 


Deutero  fraction  C. 
Only  pptd.  fr.  acid  soln. 
by    complete    satn.      w. 

iNH4)2S04. 


I 


I 

V 
Deutero - 
alhumose  A. 
Contains  0.8% 
S;     sol.     70% 
alcohol. 
V 
I 


I 

Y 
Thio- 
albumose. 
Contains  2.97 
%    S;    insol. 
70%  alcohol. 
V 
I 


I 

Y 

Deutero- 

albumose  BI, 

Insol.  35% 

alcohol. 

V 


I 


Y 

Deutero- 

albumose  Bill. 

Sol.  80% 

alcohol. 

V 


Y 

Deutero- 

albumose  C. 


Peptones  B.  (Peptones  and 
Sol.  96%  alcohol;  peptoids  can- 
no  carbohydrate;  not  be  salted 
give  biuret.  out.) 


V 

Peptoids. 

Do  not  give  biuret. 


GASTKIC    JUICE    AND    GASTRIC    DIGESTION 


G19 


in  the  same  iimuaer  as  the  imtive  Hlbnmins.    Tht*  proteids  are  split  iu 

like  innuner,  tbeir  nlbTiniiu  eomiJt»uentj^  sufferio^  the  same  changes  as 

the  uative  albumins.    The  nuclcins  ileriwd  from   the  mRleupniteiiia 

are  not  acted  upon  by  peptic  digestion.    Of  the  albuminoids  ouJy  (hpI- 

lagen  (or  its  derivative,  gelatin)   and  elastin  art^  aeted  npnn  by  the 

gastric  juice,  and  upon  them  its  action  is  slow.    They  are  converted 

into  proto-  and  deutero*gelatoses  and  clastoses,  but  they  yield  no 

^hetero  product,  which  offers  an  exphmatiou  for  the  fact  that  these 

tlbuniinoids  cannot  completely  supply  the  place  of  native  albumins  in 

the  dietary.    Animal  cell  membranes  and   connective  tissues,  being 

*tQade  up  of  keratins  and  elastin  or  collagen  in  varying  proportions, 

I  are  acted  upon  according  to  their  tenure  in  these  constituents.    The 

I  connective  tissue  of  the  pannicnlus  la  in  great  part  dissolved,  and  the 

fat  liberated.    Whether  or  no  the  stomach  produces  a  lipase,  or  gas- 

trosteapsiu,  which  sapouifles  fats,  is  a  mooted  question.  The  diastatie 

action  of  the  salivary  ptyalin  continues  in  the  stomach,  particularly 

in  the  interior  of  difficultly  permeable  masses  of  starehy  food,  until 

the  acidity  of  the  gastric  juice  has  overcome  the  alkalinity  of  the 

tnaterial  acted  upon.    How  soon  this  occurs  is  not  definitely  known, 

but  it  certainly  does  not  occur  inunediately,  and  some  time»  probably 

from  twenty  minutes  to  half  an  hour,  is  required  for  the  secretion 

.of  a  suMcient  amount  of  acid  to  cause  its  presence  uncomblned.    As 

(soon  as  the  reacHon  becomes  acid  the  amylolytic  action  ceases. 

The  duration  of  stomach  digestion  dilfers  iu  different  animals.  In 
the  herbivora,  particularly  the  ruminants,  the  stomach  is  never  empty, 
except  after  prolonged  starvation,  while  in  the  earuivora  the  organ 
may  be  completely  emptied  in  two  hours  after  a  meaL  In  man  the 
average  period  of  stomach  digestion  is  from  four  to  six  houi*s.  From 
the  stomach  the  chyrnCp  the  semi -pasty,  acid  product  of  salivary 
and  peptic  action  upon  the  food,  passes  to  the  duodenum. 

The  observed  abnormal  variations  in  composition  of  the  gastric 
juice  relate  principally  to  the  free  acid.  Free  hydrochloric  acid  may 
be  absent  (anachlorhydria)  in  neurasthenic  conditions,  in  chronic  gas- 
tritis, in  carcinoma  of  the  stomach,  and  in  the  secondary  stage  o( 
corrosion  by  mineral  acids  or  alkalies.  It  may  be  present  in  sub- 
normal quantity  (hypoehlorhydria)  in  subacute  or  chronic  gastritis, 
ulcer  of  the  stomach,  dilatation,  and  the  earlier  stages  of  carcinoma. 
Or  the  amount  may  be  greater  than  the  normal  (hyperchlorhydria) 
in  neurasthenic  patients,  or,  sometimes,  in  carcinoma.  When  the 
amount  of  free  hydrochloric  acid  is  subnormal,  fermentative  changes, 
usually  prevented  by  the  antifermentative  and  antiseptic  action  of  the 
pepsohydrocbloric  acid,  are  set  up,  with  the  formation  of  lactic  and 
even  of  acetic  and  butyric  acids,  with  liberation  of  hydmgen  and 
consequent  eructations  of  gas  and  heartburn.     These  organic  acids 


620 


MANUAL    OF    CHEMISTHy 


rany  also  treciiiently  be  present  in  the  stomach,  having  been  introduced 
with  the  food^  lactic  acid  exists  in  sour-krout^  in  pickles,  and  in  all 
kinds  of  bread;  acetic  acid  is  the  acid  of  vinegar;  and  free  bntyric 
aeid  tnay  be  present  in  butter.  It  appears  t^  have  been  demonstrated 
that  in  most  eases  of  carcinoma  of  the  stomach  lactic  acid  is  present 
in  the  stomach  contents  in  greater  amount  than  can  be  accounted 
for  by  the  test -meals  which  have  been  nsed.  Pepsin  is  very  rarely 
absent,  only  after  complete  destruction  of  the  pepsin  glands  by  the 
action  of  coiToaives.  Abnormal  constituents,  not  introduced  by  the 
month,  may  also  be  present:  urea  and  ammonium  carbonate  in 
uraemia,  acetone  in  acetonnria,  the  constituents  of  the  Vdood,  or  ' 
htematini  as  the  result  of  hcniorrJmge  into  the  stomach,  and,  fre- 
quently»  the  constituents  of  the  bile,  by  regurgitation;  also  arsenic 
and  morphin  when  they  have  been  taken  in  poisonous  dose  by  chan- 
nels of  absorption  other  than  the  month. 

Examination  of  Stomach  Contents. — Usually  it  is  desirable  to 
obtain  the  gastric  secretion  as  free  as  possible  from  the  constituents 
of  food  articles.  With  this  object  the  stomach  contents  are  collected 
after  the  stomach  has  l>een  washed  out»  and  the  secretion  of  gastric 
juice  stimulated  by  a  "test-meal.*'  Many  such  have  been  recom- 
mended, of  which  probably  the  most  serviceable  is  that  of  Boas,  con- 
sisting of  a  tablespoonful  of  rolled  oats  and  a  quart  of  water,  boiled 
down  to  a  pint,  to  which  a  little  salt  may  be  added.  The  stomach 
contents  are  collected  one  hour  after  the  meal  has  been  taken, 

Total  Acidity- — Pour  factors  may  contribute  to  the  acid  reaction 
of  the  gastric  contents:  free  hydrui'ldoric  acid,  hydnu'hh>ric  aeid  in 
pmtein  combination  (see  below),  organic  acids,  and  acid  salts.  The 
sum  of  these,  or  of  such  of  them  as  may  be  present,  constitute  the 
total  acidity.  This  is  determined  by  titrating  5  or  10  cc.  of  the  nnfil- 
tered  gastric  contents  with  NIO  (one-teuth  normal)  caustic  soda  solu- 
tion, using  phenol  plithalein  as  an  indicator.  As  each  cc.  of  the  N/10 
alkali  corresponds  to  0,00365  gm.  of  HCl,  the  number  of  ec.  of  alkali 
used,  mnltiplied  by  0.03G5  (if  10  cc,  of  gastric  contents  have  been 
used)  gives  the  percentage  of  total  acidity,  expressed  in  terms  of 
hydrochloric  acid/  Another  form  of  expression  is  sometimes  used, 
i.  e.,  the  number  of  cc.  of  N/lD  caustic  soda  solution  required  to 
neutralize  100  ec.  of  the  material.  This  is  obtained^  if  10  cc.  of  ma- 
terial are  used,  by  multiplying  the  number  of  cc.  of  N/lO  alkali 
required  to  neutralize,  by  10.  The  normal  total  acidity  after  a  Boas 
meal  is  0.15  to  0.30%  HCl,  which  is  equivalent  to  40  to  80  cc. 
N/10  NaHO. 

Presence  of  Free  Acids. ^The  next  step  is  to  determine  whether 
any  of  the  total  acidity  is  due  to  free  acids,  and  if  it  is  to  what  acid 
or  acids.      This   is   accomplished    by   the    use    of  indicators,    sub- 


GASTRIC    JUICE    AND    GASTRIC    DIGESTION 


621 


stances  giving  diflftrrent  eolors  with  uertaiii  classes  of  acid  or  alkaline 
substanues.  The  red  color  of  alkaline  phenol phthaleln^  used  as  an 
indicator  above,  is  discharged  by  all  foor  factors  con tribu ting  to  the 
acidity  of  the  gastric  conteuts,  therefore  it  is  used  in  determining  the 
total  acidity.  Congo  red  forms  an  orange-yellow  solution  in  alcohol, 
wliioh,  when  largely  diluted,  is  turned  blue  by  a  drop  or  two  of  a 
.001  per  cent  solution  of  HCl,  or  by  other  free  mineral  acids,  or  by 
organic  acids  if  present  in  sufficient  quantity,  but  not  by  acid  salts. 
If*  therefore  a  few  drops  of  the  gastric  contents  give  a  blue  color 
with  a  dnip  or  two  of  dilute  eongo-red  solution,  a  free  acid  is  prcscut. 

To  detect  free  hydrochloric  acid  an  indicator  must  be  used  which 
will  react  with  mineral  acids,  but  not  with  organic  acids  or  with  acid 
salts.  Several  have  been  suggested,  of  which  the  following  are 
desirable:  (1)  Tlie  pkhroglucin-vanUihi  reaction — Phloroglucin  and 
vanillin  are  dissolved  in  alcohol  in  the  proportion  of  2  gm.  of  the 
former  and  1  gni.  of  the  latter  in  100  cc.  of  the  solvent  (Gunzburg\s 
reagent),  A  few  drops  of  the  filtered  gastric  contents  and  the  same 
quantity  of  the  freshly  ^prepared  reagent  are  mixed  in  a  porcelain 
dish,  and  e%'aporated  on  the  water  bath:  In  the  presence  of  free  min- 
eral acids  a  brilliant  scarlet  color  is  produced,  beginukig  at  the  upper 
border.  Delicacy=,05  p/m  HCL  Not  interfered  with  by  albumoses 
or  peptones.  (2)  Eesorrin- sugar — The  reagent  (Boas'  reagent)  is 
made  by  dissolviug  5  gm.  of  resoreinol  and  3  gni*  of  sugar  in  100  cc. 
of  dilute  alcohol,  and  is  used  in  the  same  manner  as  the  pbloroglncin- 
vanillin  reagent,  giving  a  rose -red  color  with  free  mineral  acids. 
Delicacy = . 05  p/m  HCl .  ( 3 )  Dimethyl  - amido  - uzohenzfn e  —  ( Topf er* s 
test)  forms  a  yellow  alcoholic  solution,  which  turns  red  with  free 
mineral  acids.  Delicacy=.02  p/m  HCL  This  and  other  similar  testa 
are  applied  by  simply  mixing  a  few  drops  of  the  indicator  with  a 
like  qtaintity  of  tlie  contents.  Papers  colored  with  the  several  indi- 
cators are  sometimes  used,  but  they  are  not  as  delicate  as  the 
Bolutious. 

Negative  results  of  these  tests  with  a  sample  of  gastric  contents 
nf  unktwwn  origin  do  not  prove  that  the  stomach  is  not  secreting  the 
normal  quantity  of  hydrochloric  acid  {see  Quantitative,  below). 
Such  samples  are  met  with  to  which  double  the  amount  of  HCl 
Bormally  present  may  be  added,  and  not  reveal  its  presence  upon 
application  of  the  tests. 

Quantitative  Determination  of  HCL— Chlorin  may  exist  in  the 
^stric  coutents  during  digestion  of  usual  food  articles  in  three  forms 
of  combination:  as  free  hydrochloric  acid,  as  "loosely  combined'^ 
acid,  and  as  chlorids,  all  of  which  must  be  taken  into  consideration, 
along  with  the  acid  salts  and  organic  acids^  in  determining  the 
amount  of  HCl  produced  by  the  stomach.      By  ■■loosely  combined 


622  MANUAL    OF    CHEMISTRY 

HCl "  is  meant  that  portion  of  the  free  HCl  secreted  by  the  stomach 
which  has  entered  into  combination  with  the  proteins  to  form  acid- 
albumins;  and  the  "effective  HCl"  is,  clearly,  the  sum  of  the  free 
and  the  loosely  combined.  The  quantity  of  acid  that  can  be  thus 
combined  is  considerable.  Thus  100  gm.  of  each  of  the  following 
food  articles  can  take  up  the  amounts  of  HCl  stated,  in  grams  : 
Cheese  -1.3  to  2.6,  meat  -1.6  to  2.2,'  milk  -0.42,  bread  -0.3  to  0.7, 
beer -0.15. 

Of  the  several  methods  which  have  been  devised,  probably  the 
most  desirable  are  those  of  Topfer  and  of  Martins  and  Liittke,  some- 
what modified,  the  former,  based  upon  the  use  of  indicators,  being 
the  more  rapid  of  the  two,  the  latter,  based  upon  chlorin  determina- 
tions in  part,  the  more  accurate. 

Topfer^s  Method. — Three  samples  of  10  cc.  each  are  separately 
titrated  with  N/10  NaHO  solution;  in  (1)  using  phenol phthalein  as 
an  indicator,  and  carrying  the  addition  of  alkali  to  a  distinct  red,  not 
to  faint  pink  as  is  usual.  This  gives  the  total  acidity  (A),  made  up 
of  free  HCl  (L),  protein  HCl  (C),  and  organic  acids  and  salts  (0). 
In  (2)  alizarin  is  used  as  an  indicator,  to  pure  violet.  This  gives  the 
acidity  due  to  (L+O),  and,  therefore  the  result  of  (2),  subtracted 
from  that  of  (1),  leaves  the  value  of  (C)=protein  HCl.  In  the  third 
sample  (3)  dimethyl -amido-azobenzene  is  used  as  an  indicator,  to 
yellow.  This  gives  the  value  of  (L)  alone,  i.  e.,  free  hydrochloric  acid. 
If  the  value  of  (O)  be  desired,  it  may  be  obtained  by  subtracting  the 
result  of  (3)  from  that  of  (2).  In  each  of  the  above  titrations  the 
number  of  cc.  of  alkaline  solution  used,  multiplied  by  0.0365,  gives 
the  result,  expressed  in  percentage  of  HCl. 

Martius  and  Liittke^ s  Method, —  Four  samples  of  10  cc.  each  of 
the  filtered  material  are  taken.  In  (1),  the  total  chlorin  (T)  is  deter- 
mined either  volumetrically  with  a  N/10  solution  of  AgNOa  and 
thiocyanate  as  an  indicator,  or,  preferably,  gravimetrically,  by  the 
usual  methods.  The  result,  expressed  in  terms  of  HC1=(T),  consists 
of  free  HCl  (L),  protein  HCl  (C),  and  chlorin  in  chlorids  (F).  In 
the  second  10  cc.  (2),  the  chlorids^  (F)  are  determined  by  evaporating 
to  dryness,  incinerating  at  dull  redness,  redissolving  in  water,  and 
determination  of  HCl  as  in  (l).  The  effective  HCl  (L+C)  is  deter- 
mined by  subtracting  (F)  from  (T).  In  the  third  sample  (3),  the 
total  acidity  (A)  is  determined  by  titration  with  N/10  NaHO  solution 
and  phenolphthale'in.  The  acidity  due  to  organic  acids  (O)  is  arrived 
at  by  subtracting  (L+C)  from  (A).  In  the  fourth  sample  (4)  the 
free  HCl  (L)  is  directly  determined  by  titration  with  N/10  NaHO, 
using  diraethyl-amido-azobenzene  as  the  indicator.  Finallj-,  the 
value  of  (C)  is  obtained  by  subtracting  (L)  from  (L+C). 

Morner  and  ISjoqvist'S  Method. — By  this  motliod   the  quantity-  of 


GASTRIC    JUICE    AND    GASTRIC    DIGESTION 


623 


"effective  HCl"  can  be  deterruiiied  iiir>re  expeditiously  tiian  by  Martins 
an  J  Liittke-s  method,  aod  as  aeeurutely.  It  is  based  upon  tlie  fact 
that  if  the  gastric  juice  be  evaporated  viith  BaCOa,  and  the  residue 
incinerated,  both  free  and  protein  bydroebloric  acid  form  BaCbi 
while  the  organic  acids  arc  destroyed,  and  neither  the  acid  Halts  nor 
the  chlorids  enter  into  consideration.  Pure,  pulverized  BaCOs  is 
added  to  10  cc.  of  the  gastric  contents,  and  evaporated  to  dryness. 
The  residue  is  moderately  ignited  until  white,  and  extracted  with  hot 
water-  To  the  filtered  extract  (about  50  cc*)  an  equal  volniue  of  94 
per  cent  alcohol  and  0.75  cc.  of  a  10  per  cent  solution  of  sodium 
acetate  in  dilute  acetic  acid  are  added,  and  the  barium  determioed  by 
titration  with  a  solution  of  potassintn  dichromate  containing  8,5  gm* 
p/L,  standardized  with  a  N/lO  solution  of  BaCla,  and  using  paper 
impregnated  with  tetramethyldiamidobenzeue  as  an  indicator,  the  end 
reaction  being  the  formation  of  a  blue  color  in  one  minute.  If  the 
K2Cr207  sohition  and  the  N/10  BaCI^  solutions  are  equivalent,  the 
amount  of  hydrochloric  acid  is  obtained  by  multiplying  the  number  of 
cc,  used  by  0.00405. 

Lactic  Acid. — The   presence  of   lactic  acid   is   detected   Ijv  :    (1 ) 

rfflemann's  reagent ,  which  consists  of  a  solution  of  FetiCU  and  plienol 

diluted  to  an  amethyst- blue  color,  which   is  changed  to  yellow  by 

lactic  acid.     In  order  to  avoid  error  by  the  action  of  other  substances 

which  have  a  like  action    upon    the   reagent,  10  cc.  of  the  filtered 

gastric  contents  are  agitated  with  ether,  and   the  ethereal   extract 

separated  and  agitated  with  the  reagent;   or»it  may  be  evaporated* 

the  residue  dissolved  in  water,  and  the  solution  added  to  the  reagent. 

(2)  Bouii^  method,  which  is  more  reliable,  and  wiiich  depends  upon 

the  formation  of  aldehyde  from  lactic  acid  by  the  action  of  oxidants 

(p.    341),    and    the   behavior    of   aldehyde    with    Nessler\s   solution 

(p.  151),     Ten  cc.  of  the  contents  are  treated  with  excess  of  BaCOa^ 

and  evaporated  to  dryness  on  the  water  bath,  to  a  syrup ;    this  is 

treated  with  dilute  H3PO4*  heated  to  boiling,  cooled,  and  extracted 

with  ether  by  agitation.     The  separated  ethereal  extract  is  evaporated 

and  the  residue  extrncted  with  water.     The  aqueous  solution  is  then 

mixed  with  5  cc.  H2SO4  and  a  little  MuOa,  and  distilled,  the  distillate 

being  received  in  a  eyliuder  containing  Ncssler^s  reagent,  which  is 

turned  yellow,  or  deposits  a  yellow*red   precipitate,   if  aldehyde   be 

preseut.     Or  the  distillate  may  be  received  in  a  N/lO  normal  solution 

of  iodin,  with  which  aldehyde  forms  iodoform,  recognizable  by  its 

odor,  or  by  the  formatiou  of  a  yellow,  crystalline  precipitate,  if  the 

Quantity  be  suffic  irot. 

The  iodin  I'eaction  is  utilized  for  quantitative  determioation.  The 
ilistillHtion  with  H^SO*  and  Muih  is  conducted  in  a  current  of  air,  and 
coutiuued  until  four- fifths  of  the  material  have  distilled  over.  Tlir  dis- 


624  MANUAL    OP    CHEMI8TBY 

tillate  is  heated  with  20  ee.  normal  KHO  solution  and  20  cc.  K.'lO 
iodin  solation,  agitated  and  allowed  to  stand  a  few  minutes.  The 
amount  of  unused  iodin  remaining  is  then  determined  by  addition  of 
20  cc.  HCl,  sp.  gr.  1.018,  and  titration  with  N/10  sodium  thiosolfate 
solution,  using  starch  paste,  added  near  the  end  of  the  titration,  as 
an  indicator.  The  number  of  cc.  of  iodin  solution  used  in  the  forma- 
tion of  iodoform,  multiplied  by  0.003388,  gives  the  quantity  of  lactic 
acid. 

The  presence  of  butyric  acid  may  be  recognized  by  extracting 
10  cc.  with  50 cc.  of  ether  by  agitation,  evaporating  spontaneously, 
and  adding  a  few  drops  of  water  and  some  solid  CaGl2  to  the  solution, 
when  oily  drops  separate,  and  the  characteristic  odor  of  butyric  acid 
is  developed.  The  quantity  of  volatile  acids,  butyric  and  acetic,  may 
be  ascertained  by  determining  the  total  acidity  in  one  sample  of 
10  cc.  by  the  method  given  above;  evaporating  another  sample  of  10 
cc.  to  a  syrup,  redissolving  in  water,  and  determining  the  acidity  of 
the  solution.  The  difference  between  the  two  determinations  is  the 
acidity  due  to  volatile  acids. 

Pepsin  and  Pepsinogen. — If  free  HCl  be  present  the  gastric  con- 
t  mts  are  examined  for  the  presence  of  pepsin  by  placing  about  .05 
gin.  of  coagulated  white  of  egg,  cut  into  discs  or  cubes,  in  25  cc.  of 
tlio  material,  which  is  then  kept  at  38-40°.  Digestion  should  be 
complete  in  about  three  hours,  or  the  edges  of  the  fragments  rounded 
perceptibly  in  less  time.  If  no  free  HCl  be  present,  pepsinogen  is 
tested  for  as  above,  five  drops  of  dilute  HCl  having  been  added  to  the 
material.  Sliould  the  result  be  negative,  200  cc.  of  N/lO  HCl  should 
be  introduced  into  the  stomach,  the  contents  of  which  are  removed 
in  half  an  hour  and  tested  as  above. 

No  quantitative  method  of  determining  pepsin  is  possible  at 
present.  Comparisons  of  the  degrees  of  activity  of  a  given  sample  of 
gastric  contents  with  some  pharmaceutical  pepsin  may  be  made  by 
adding  5  cc.  of  the  former  and  0.5  gm.  of  the  latter  in  two  tubes  to 
10  ce.  of  a  1%  solution  of  serum  albumin  containing  3  p/m  of  HCl, 
and  after  24  hours  determining  the  amount  of  albumin  remaining 
undigested,  by  the  usual  methods  (p.  738). 

Sometimes  it  is  desirable  to  test  the  stomach  contents  for  the 
products  of  digestion.  This  is  done  as  follows:  The  filtered  con- 
tents are  accurately  neutralized  with  dilute  NaHO,  using  litmus  as  an 
indicator;  if  syntonin  be  present,  it  will  form  a  precipitate,  soluble 
in  excess  of  acid  or  of  alkali.  The  liquid,  freed  from  syntonin,  is 
acidulated  with  very  dilute  acetic  acid,  and  an  equal  volume  of  satu- 
rated NaCl  solution  is  added,  and  the  mixture  heated  to  boiling;  a 
coagulation  indicates  the  presence  of  native  albumins.  A  part  of 
the  filtrate  is  tested  for  primary  albumoses  by  addition  of  HNO3  and 


PANCREATIC    SECRETION    AND    DIGESTION 


625 


I 


I 


heating;  a  precipitate  in  the  cold,  wliieli  disappears  witli  lieat,  and 
returns  on  cooling,  indieates  their  presence.  Another  portion  of  the 
filtrate  is  tested  for  secondary  albumoses,  wijii'li  an*  precipitated,  if 
not  present  in  too  small  amount »  by  saturation  with  NaCI.  The 
remainder  of  the  filtrate  is  saturated  with  {NH4)2S04,  filtered,  treated 
with  coneeiitnited  NaHO  solution  in  slifjht  excess,  allowed  to  settle, 
decanted,  and  the  clear  liquid  tested  for  peptones  with  a  few  drops  of 
a  2%  CuSOi  solution,  which  gives  a  rose -red  or  reddish -violet  color 
in  the  alkaline  solution  if  they  are  present. 

Ewald^s  test  for  the  activity  of  the  motor  function  of  the 
stomach  depends  upon  the  fact  that  salol  passes  through  the  stomach 
unchanged,  but  is  decomposed  in  the  intestine,  with  liberation  of 
salicylic  acid,  whose  presence  in  the  urine  may  be  then  detected. 
About  0.7  gm.  of  salol  are  administered  by  the  mouth,  and  the  urine 
is  collected  at  I'egular  intervals,  and  tested  by  addition  of  a  few  drops 
of  Fe2Cl<i  solution,  which  gives  a  violet  color  with  salicylic  acid. 
The  reaction  should  appear  in  40  to  70  minutes,  and  should  cease  in 
30  hours.  The  rcsorptivc  activity  of  the  stomach  may  be  tested  by 
administering  0.2  gm.  of  potassium  iodid  in  a  capsule,  and  testing 
the  saliva  e^^ery  two  minutes  by  moistening  a  test-poper,  made  by 
impregnating  titter -paper  with  starch  paste,  with  the  saliva,  and  then 
touching  it  with  a  glass  rod  dipped  in  yellow  HNO3,  which  turns  blue 
ith  KL     The  reaction  should  be  obtained  in  5*10  minutes. 


PANCREATIC   SECRETION   AND   DIUESTIOK. 


^  dd  in  character,  thai  of  tiie  gastric  juii^e  may  be  dispensed  with,  and 
T  tM.e  functions  of  bath  are  continued  and  may  be  completely  replaced 
i>^"'  those  of  the  pancreatic  secretion.  The  pancreatic  juice  may  there- 
fc^m^  be  said  to  be  tlie  most  active  and  essential  agent  of  digestion. 
X^liEe  pancreas,  ov  a  corresponding  *u*gan  in  which  certain  of  the  func- 
•i^^^HB  of  the  liver  are  associated  with  its  own,  exists  in  all  animals,  and 
•  mecessary  to  life.  The  pancreas  also  plnys  a  part  in  the  essential 
fc^^tabolic  processes  of  the  system,  and  its  reujoval  is  ftdlowed  by  the 
^'I^;K:»earance  of  an  intense  glycosuria,  attended  by  acidosis,  i.  e*,  the 

£<3?reased  formation  of  acetone  and  related  acid  substances. 
The  digestive  function  of  the  pancreJis  ouly  will  be  considered  in 
i^  place.     The    pancreatic  juice    is  produced    continuously  in   the 
^^^^l)ivora,  but  intermittently  in  tlje  carnivora,  while  in  both  its  for- 
**^^^tion  ceases  during  starvation.     In  the  carnivora  the  maximum  of 
*^^i*etion  is  reached  (with  milk  feeding)  in  about  three  hours  after 
5^tiiio^^  with  another  rise,  following  a  diminution,  from  two  to  four 
*^*>Ur8  later.     Its  secretion  follows  the  passage  of  the  acid  chyme  into 


626 


MANITAL    OF    CHEMISTRY 


the  duodenum.  The  activity  of  thti  pancreatic  cells  is  probably  ineited 
in  two  ways*  Partly  by  reflex  nervous  stimulation  (Powlow).  This  is, 
however,  not  the  only  method^  as  injection  of  an  acid  into  a  loop  of 
jejunnra  whose  nerve  supply  has  been  completely  severed  still  provokes 
activity  of  the  gland.  The  second,  and  probably  the  most  important, 
method  of  stimulation  is  the  production  in  the  upper  intestine  of  a 
substance,  called  secretin,  which,  being  carried  by  the  blood  to  the 
pancreas,  stimulates  its  cells  to  secretion  (Baylies  &  Starling),  The 
epithelial  cells  of  the  duodeuum  and  upper  jejunum  produce  a  pro- 
secretin, which  on  contact  w4th  acids  forms  secretin.  This  is  supposed 
to  be  a  definite  chemical  entity.  It  is  not  an  enzyme,  because  it  may  be 
boiled  in  acid,  neutral  or  alkaline  solution  without  suffering  harm,  and 
it  is  not  precipitated  either  by  tauuin  or  by  alcohol.  Its  injection  into 
the  circulation  is  followed  by  increased  secretion  of  normal  pancreatic 
juice,  and  also  of  bile.  Moreover,  if  an  acid  be  injected  into  the 
duodenum  of  one  dog,  pancreatic  secretion  is  stimulated  in  a  second 
dog  into  whose  veins  the  blood  of  the  first  is  transfused.  Neither 
secretin  nor  prosecretin  is  identical  with  euterokinase  (p.  627), 

The  secretion  has  been  obtained  from  man  in  rare  cases  of  pan- 
creatic fistuUe  following  surgical  operations.  It  can  be  obtained  fi-oni 
temporary  fistult^,  established  in  the  pancreatic  duct  in  animals,  or 
from  permanent  fistula,  but  the  secretion  obtained  from  the  latter 
becomes  changed  from  the  normal  in  composition  in  a  few  hours 
dogs  the  amount  normally  secreted  is  estimated  at  from  2.5  to  5  gms 
per  kilo  per  diem,  but  the  amounts  obtained  from  permanent  fistula* 
are  much  greater.  The  quantity  secreted  by  man  has  been  calculated  to 
be  150  gms.  daily,  although  in  two  cases  of  pancreatic  fistulae,  in 
which,  however,  the  secretion  was  probably  modified  as  is  that  of  per- 
manent fistulffii  in  animals,  the  amounts  obtained  were  600  gms* 
(Pfaff),  and  700  to  900  gms,  (Gla^ssner),  respectively.  The  pan- 
creatic  juice  of  the  dog  is  clear,  transparentt  colorless,  odorless,  viscid, 
sp.  gr.  1008  to  1010,  and  strongly  alkaline,  the  alkalinity  being  equal 
to  about  3  p/m  of  Na^OOu.  The  alkalinity  and  trypsin  content  of  this 
secretion  increase  during  digestion.  On  exposure  to  air  it  rapidly 
loses  its  transparency  and  its  viscidity,  deposits  lencin  and  ty rosin 
crystals,  and  its  proteins  undergo  putrefactive  changes,  to  which,  as 
well  as  to  autolysis,  it  is  exceedingly  prone. 

Composition,— The  secretion  from  a  temporary  fistula  in  the  dog 
contains:  water,  900.8;  solids,  99.2.  The  solids  consist  of  mineral 
Bubstances  8.8,  and  organic  substances,  90.4,  of  which  60.2  are  pro- 
teins and  enzymes  (Schmidt).  In  the  secretion  from  a  permanent  fis- 
tula in  the  dog  the  amount  of  solids  is  notably  less;  water,  980.44; 
solids,  19.60,  of  which  3.57  mineral  salts,  and  lC-03  organic  (Kriiger). 
In  another  dog  with  a  temporary  fistula  the  solids  were  found  to  vary 


I 


I 


I 


I 


I 


PANCREATIC    SECRETION    AND    DIGESTION  G27 

with  the  quautity  of  the  stjcretion  from  20  tu  D3  pirn  (Lesag:e)»  The 
pancreatic  seen.^iou  fouud  in  an  occluded  caoal  of  Wirsuiig,  in  a  njan 
suffering  from  cancer,  contained  24.1  p/m  of  solids,  of  which  11.5  p/m 
consisted  of  proteins  and  enzymes,  and  6.2  of  salts  (Herter).  The 
secretion  from  a  pancreatic  fistula  remaining  in  a  woman  after  exttrpa- 
tiou  of  a  carcinoma  contained  135*9  p/m  of  solids,  of  which  3.44  were 
minerat  salts  and  92.05  proteins  (Zawadsky).  The  quantitative  com* 
position  is  therefore  subject  to  great  variations. 

The  mineral  constituents  are  sodium  and  potassium  chlorids  and 
phosphates,  sodium  and  potassium  carbonates,  to  which  the  liquid 
owes  its  alkalinity,  and  compounds  of  caleium,  magnesium  and  iron. 
The  organic  constituents  include  small  quantities  of  leuein,  tyrosiu, 
purin  bases,  fat,  soaps,  fibrinogen,  a  nueleoproteid,  much  albumin 
and  globulin,  sufficient  to  cause  the  liquid  to  form  a  solid  coagulum 
when  heated  after  acidulation.  and  at  least  three  enzymes  or  their 
zymogens,  one  a  proteolytic  enzyra,  trypsin,  another  an  amylolytic 
enzyme,  pancreatic  diastase,  or  ainylopsin,  and  the  third,  having  a 
saponifying  action,  steapsin. 

Trypsin, — This  and  other  pancreatic  enzymes  do  not  exist  as  such 
in  the  gland  cells.  These,  as  well  as  the  pancreatic  secretion  as  col- 
lected from  the  duct,  contain  the  zymogen,  and  neither  the  secretion 
nor  an  extract  of  the  fresh  pancreas  has  auy  proteolytic  action. 
Trypsin  is  produced  from  trypsinogen  by  exposure  of  the  hashed  pan- 
creas to  air.  In  the  body,  the  formation  of  trypsin  from  trypsinogen 
is  due  solely  to  the  action  of  another  enzyme,  enterokinase,  produced 
in  the  intestinal  mucous  membrane .  Neither  the  acid  of  the  gas^tric 
jnice  nor  other  acids  produce  this  effect^  as  was  formerly  supposed, 
bat,  on  the  contrary,  they  tend  to  hinder  the  action  of  enterokinase, 
Trypsinogen  is  not  formed  during  fasting,  but  its  production  begins 
soon  after  food  is  taken,  and  reaches  its  maximum  in  about  four 
hours.  Trypsin  is  very  soluble  iu  water;  insoluble  in  alcohol.  In 
the  purer  states  in  which  it  may  be  obtained  it  is  insoluble  in  glycerol, 
although  in  a  more  impure  form  it  is  soluble  in  that  liquid,  which  may 
be  used  to  extract  it  from  the  hashed  gland.  In  acid  solution  trypsin 
is  destroyed  at  45*^,  less  rapidly  in  the  presence  of  albumoses,  and  in 
alkaline  solution  {0,25-0.5  per  cent  NaHO)  at  50°.  When  dry  it 
is  not  affected  by  a  temperature  of  100°,  and  at  higher  temperatures  it 
is  gTadually  destroyed,  completely  at  160°.  In  aqueous  solution  crude 
trypsin  is  decomposed  into  an  albumin,  which  coagulates,  and  an 
albumose  by  addition  of  a  little  acid  and  boiling.  But  trypsin  has 
been  obtained  which  does  not  give  the  biuret  reaction,  and  therefore 
cannot  contain  an  albumin. 

Tryp>iin  is  obtained  in  a  condition  most  nearly  approaching  purity 
by  the  Kiihue-Ciautier  method:   The  hashed  pancreas,  after  a  day's 


MANUAL    OF    CHEMTSTEY 


exposure  to  air  at  the  room  temperature,  is  exti'aeted  io  the  cold  with 
1  pirn  aqueous  salieylii!  a^id.  The  extract  is  reiith'red  faiutly  alkaline 
with  thymolized  Na2C0;t  sohitiou  (5  pitOi  aud  uutolysed  for  a  week  at 
38°  to  remove  albumins  aud  the  other  enzymes  as  much  as  possible. 
The  filtered  sohitiou  is  theu  saturated  with  ammonium  sulfate;  the 
precipitate,  which  eoutaius  the  trypsin,  washed  with  saturated 
ammonium  sulfate  solution,  dissolved  in  water,  subjected  to  dialysis, 
and  precipitated  with  alcohoL 

Action  of  Trypsin. — The  most  characteristic  property  of  trypsin 
is  its  jjower  of  diasolviug  native  or  coagulated  albumins  in  alkaline  or 
extremely  faintly  acid  reaction ,  with  formation  of  albumoses,  peptones 
and  simpler  crystalline  products.     Norniaily  it  continues  and  supple- 
ments the  similar  action  of  pepsin »  hut  sucb  preliminary  treatment  of 
the  proteins  is  by  no  means  necessary  to  its  efficiency.     Not  only  is  it 
capable  of  digesting  native  albumins,  but  its  action  in  this  regard  is 
more  rapid  than  that  of  pepsin,  and»  in  equal  time,  proceeds  to  more 
advanced  decomposition.     If  putrefaction  be  prevented,  the  panciTas 
rapidly  undergoes  autolysis  at  38"^,  resulting  in  the  decouj position  not 
only  of  the  proteins  of  the  organ,  but  also  of  the  other  enzymes  and 
zymogens.     The  action  of  trypsin  upon  lihrin  is  the  most  energetic, 
but  it  also  dissoh^es  albumins  and  gloljulins,  native  or  coaguInteJ, 
rapidly,  and  gelatin,  which  is  only  slightly  acted  upon  by  pepsin,  as 
well.    It  acts  best  in  the  presence  of  3  to  4  p/ra  of  Na2C03.    Its  action 
is  arrested  by  the  presence  of  even  very  suuill  quantilies  of  mineraJ 
acids,  but  not  by  protein -hydrochloric  acid.     Organic  acids  causeless 
interference,  and  lactic  acid  in  the  pi-oportion  of  0.2  p/m  in  presence 
of   bile  and  of   NaOI,  none  whatever.     Its  action  is  diminished  by 
accumulation  of  its  products. 

The  acid  chyme,  the  product  of  salivary  and  gastric  digestion, 
passes  into  the  duodenum,  where  it  meets  the  bile  and  the  ptincreatie 
and  enteric  secretions,  whose  alkalinity  soon  overcomes  the  acidity* 
The  pepsin  is  destroyed,  peptic  digestion  ceases,  and  pancreatic  dig^^^* 
tion  begins.  Considering  here  the  proteins  of  the  chyme,  this  '*raw 
material"  for  the  action  of  trypsin  may  contain  native  and  coagulft^fd 
albumins,  acid  albuminates,  primary  and  secondary  alboraos*^^  ^' 
both  henii  and  auti  groups,  antialbumid  and  small  quantities  of  P<?P* 
tones.  In  discussing  tryptic  digestion,  it  is  important  to  hold  iDDii^^ 
the  distinction  between  that  degree  of  such  action  for  which  th<?tf  »s 
time  during  the  sojourn  of  the  material  in  the  small  intestitn^t  ^^*^ 
which  actually  occurs  in  the  body,  and  the  much  more  complex* 
decomposition  of  the  proteins  which  is  brought  about  by  long-can* 
tinned  action  of  trypsin  at  the  body  temperature.  The  action  d 
trypsin,  continued  during  several  days,  is  very  similar  to  that  of  tot 
mineral  acids,  producing  finally  complete  disappearance  of  the  biuret 


PANCREATIC    SECRETION    AND    DIGESTION  629 

reaction,  and  ''end  products''  of  low  molecular  weight,  aud  of  com- 
paratively simple  chemical  composition  and  constitution,  which  are- 
probably  nseiess  for  purposes  of  nutrition;  and  probably  the  stage 
of  formation  of  trypsin -peptones  is  the  limit  of  ^*  natural"  tryptic 
digestion. 

With  the  change  from  acidity  to  alkalinity  any  native  or  coagulated 
albumins  and  acid  albuminates  are  converted  into  alkali  albuminates,. 

I  the  action  of  the  alkali  being  accelerated  by  the  enzyme.  The  alkali 
albuminates  are  rapidly  converted  by  trypsin  into  deuteroalbumoses, 
without  preliminary  formation  of  primary  albumoses,  which  latter, 
present  in  the  chyme  as  products  of  peptic  digestion,  are  also  con- 
verted into  deuteroalbumoses,  tbe  heteroalbumoses  more  slowly  thaa 
the  protoalbumoses.  The  henii  groups,  contained  in  the  deiiteroid- 
bumoses  A  and  the  thioalbumoses  are  then  split  to  tryptophane 
(p*  540)  and  amido  acids,  and  from  the  anti  groups  and  pepsin -pep- 

I  tones  the  trypsin* peptones  are  derived. 
These  antipcptones,  although  obstinately  withstanding  further 
decomposition  by  trypsin,  are  slowly  attacked  by  it,  and  by  suffictt-ntly 
prolonged  autolysis  of  pancreatic  tissue  are  broken  down  to  prudnets 
no  longer  giving  the  biuret  reaction.  Siegfried's  pepsin* fibrin -pep- 
tone o.  is  decomposed  by  tryptic  digestion,  splitting  off  ty rosin  and 
other  amido  acids,  and  yielding  two  antipeptones,  trypsin-fibrin-pep- 
tones  <»,  CioHitNiiOs^  and  P^  CnHiijNjjOs,  which  are  acids,  giving  the 
biuret  but  not  the  Millon  reaction,  containing  no  tyrosin  group,  pre- 
cipitated by  alcohol,  and  resisting  further  decomposition  by  trypsin. 
On  hydrolysis  by  mineral  acids  they  yield  arginin,  lysin  and  glutamic 
and  aspartic  acids.  Less  than  25  per  cent  of  their  total  nitrogen  is 
contained  as  basic  nitrogen,  and  the  a -acid  yields  21,9  per  cent  uf  its 
nitrogen  as  ammonia  and  the  j3-acid  16,1  per  cent.  The  trypsin- 
glutin -peptone  ^  of  Siegfried,  CioHatiNeO*,  itself  an  acid,  on  decom- 
position by  HCl  yields  a  basic  peptone,  CjiHaoNsOg,  called  glutokyrinp 
which  gives  the  biuret  reaction,  and  on  further  decomposition  yields 
two* thirds  of  its  nitrogen  as  arginin  and  lysin,  and  one*third  as 
glutamic  acid  and  another  amido  acid,  probably  glycocoIL 

Antialbumid,  which  is  not  further  decomposed  by  peptic  digestion, 

produces  by  tryptic  digestion  a  gelatinous  coagnlum,  which  does  not 

give  the  Millon  reaction,  and  which  apparently  belongs  to  the  class 

of  plastetns,  compounds  wdiich  are  peptoids,  not  giving  the  biuret 

reaction,  produced  by  pepsin,  trypsin   and   papayotin   from  concen* 

trated  solutions  of  albnmoses, 

-  Among  the  products  of  further  tryptic  decomposition  of  the  pep* 

I   tones  are  Ptscher^s  polypeptids,  which  give  the  biuret  reaction  and 

therefore  come  withiii  the  definition  of  tire  peptones,  and  which  are 

L   with  difficulty  decomposed  by  trypsin  into  amido  acids,  which  do  not 


% 


630  MANUAL    OF    CHEMISTRY 

give  that  reaction.  Among  these  is  "Curtius'  base,"  probably-  hexa- 
glycylglyein  ester,  H2N.(NH.CH2.CO)6.CH2.COO(C2H5),  which  by 
tryptic,  but  not  by  peptic,  digestion  yields  glycocoll,  with  disappear- 
ance of  the  biuret  reaction.  As  trypsin  does  not  split  biuret,  oxamid, 
nialonamid  or  other  acid  amids,  it  would  appear  that  the  groaping 
N.CH2.CO.N  is  more  truly  characteristic  of  the  protein  molecule  in 
its  response  to  the  biuret  reaction  than  is  the  grouping  N.CO.CO.N 
of  biuret  and  the  acid  amids  (p.  407).  Another  product  of  peptic  and 
tryptic  digestion  of  globin  (p.  660) ,  containing  a  modified  N.CH2.CO.N 
group,  and  giving  the  biuret  reaction,  is  leucinimid,  or  leucin  anhy- 
drid,  which  readily  yields  the  dipeptid  leucylleucin.  The  peptic 
leucinimid  is  apparently  identical  with  the  synthetic  product,  but  the 
tryptic  leucinimid  differs  from  it  in  fusing  point  and  in  solubility. 
The  polypeptids  on  decomposition  yield  aliphatic  amido  acids:  glyco- 
coll, alanin,  leucin,  aspartic  and  glutamic  acids  (p.  415),  and  also 
phenylalanin  and  prolin  derivatives  (p.  511). 

The  formation  of  peptones  and  the  further  splitting  of  albumoses 
and  peptones  to  disappearance  of  the  biuret  reaction  by  pancreatic 
action  do  not  proceed  parallel   with  each  other.     The  peptonizing 
action  increases  with  duration  of  the  action,  because  of  the  formation 
of  trypsin  from  the  zymogen,  but  the  peptone  splitting  action  di- 
minishes.   This  is  explained  by  the  supposition  that  the  splitting  of 
peptones  and  albumoses  is  effected  partly  by  trypsin  and  partly  by 
another  enzyme,  which   is  destroyed   by  the   trypsin.    This  second 
enzyme  is  called  pancreas  erepsin  (Vernon), because  of  the  similarity 
of  its  action  to  that  of  the  erepsin  of  the  intestinal  mucosa  (632). 
The  two  erepsins  are,  however,  not  identical,  for,  while  the  activity  of 
both  is  increased  by  an  increase  of  alkalinity  to  the  extent  of  0.4  to 
1.2  per  cent  of    Na2C03,  at   this  degree  of  alkalinity  the  intestinal 
erepsin  is  destroyed,  but  the  pancreatic  is  not. 

Tlie  proteids  are  split  by  trypsin  in  the  same  manner  as  by  pepsin, 
and  their  albumin  components  are  digested  as  native  albumins.  The 
nuclei ns  and  those  nucleoproteids  which  resist  peptic  action  are 
decomposed  by  trypsin  with  formation,  not  of  nucleins,  but  of  nucleic 
a(uds,  which  are  in  turn  acted  upon,  but  not  to  the  extent  of  liberatiou 
of  xanthin  bases  and  a  phosphorus  acid.  The  protamin  of  salmon 
melt  is  digested  by  trypsin,  with  formation  of  amido  acids  andarginiD- 

After  prolonged  fasting,  on  giving  food  rich  in  fats,  regurgitation 
of  pancreatic  juice  and  bile  into  the  stomach  has  been  observed.  The 
stomach  contents  then  become  alkaline  and  contain  notable  quantities 
of  active  trypsin,  and  pancreatic  digestion  then  begins  in  the  stomach 
(Boldireff). 

Autolysis,  or  autodigestion,  of  an  organ  is  self -digestion  of  the 
constituents  of  the  organ  after  death,  with  complete  exclusion  of  bac- 


PANCREATIC    SECRETION    AND    DIGESTION 


631 


terial  action.  It  is  supposed  to  be  prod  need  by  ^'autolytic  enzynies" 
contained  in  the  cells,  and  is  particularly  active  in  the  liver  and  pan- 
creas.  So  far  as  observed,  the  action  i&  essenttully  post-mortem,  but 
whether  any  similar  action  occurs  during  life  or  not  is  unkuowo.  In 
autolysis  of  the  pancreas  the  products  differ  somewhat  from  tliose 
pi-oduced  by  tryptic  digestion,  Guanidin  is  produced,  and  th*'  amount 
of  nitrogen  separable  as  ammonia  by  distillation  of  the  products  of 
decomposition  with  magnesia  is  greater  than  that  which  is  split  from 
the  original  material  as  ammonia  by  hydrolysis  by  acids,  showing  that 
the  decomposition  has  proceeded  beyond  the  stage  of  formation  of 
ainido  acids,  which  is  not  the  case  with  tryptic  digestion.  Besides  the 
products  of  tryptic  digestion,  oxyphenylethylamin  is  produced  during 
autolysis,  probably  resulting  from  tyrosin  by  splitting  off  of  carbon 

dioxid:  (HO)CoH4,CIIi.CHNH2.COOn=^™^c!H;)^^+^*^2.  Uracil 
and  xauthin  bases  are  also  produced  from  the  nucleoproteids,  and 
cboliu  fmra  the  lecithins.  During  six  weeks'  autolysis  a  substance 
called  skatosin,  CioHieN^O^,  is  produced  (Baum).  It  is  basic,  pre- 
cipitates with  phosphotungstic  acid,  forms  a  yellow  precipitate  with 
bromin  water,  produces  a  tetrabenzoyl  derivative,  gives  au  odor  of 
skatole  when  fused  with  KHO,  and  appears  to  belong  to  the  indole 
group. 

Pancreatic  diastase,  or  amylopsin,  which  may  be  extracted  from 
the  gland  tissue  after  exposure  to  air,  by  salicylated  water  or  glycerol, 
begins  to  be  produced  at  the  end  of  the  first  mouth  of  infant  life.  Its 
action  is  similar  to  that  of  the  ptyaliu  of  the  saliva,  and  whether  the 
two  enzymes  are  identical  or  not  is  still  a  mooted  question.  The 
action  of  amylopsin  upon  cooked  stanih  is  energetic,  and  it  also 
hydrolyses  raw  starch,  more  slowly,  at  37--40°.  The  limit  of  its  action 
is  the  formation  of  maltose,  or  isomaltosc.  It  dues  not  hydrolase 
either  maltose,  lactose  or  saccharose  further,  nor  does  the  pancreatic 
secretion  contaiu  a  maltase,  a  lactase,  or  a  sucrase, 

Paocrcatic  lipase,  or  steapsin,  saponifies  the  fats  with  formation 
€f  glycerol  and  fatty  acids.  The  latter,  cotnbining  with  the  alkali, 
form  soaps,  which  aid  to  emulsify  the  remaining  fat.  This  enzyme  is 
less  resistant  than  trypsin  or  amylopsin,  and  can  only  be  extracted 
from  the  fresli  gland,  not  from  one  which  has  l>een  exposed  to  air. 
Its  activity  is  increased  by  the  presence  of  bile  or  of  the  intestinal 
secretion.  The  pancreas  also  exerts  an  influence  upon  the  absorption 
and  metabolism  of  fnt  other  than  that  by  its  secretion.  After  ligation 
of  the  pancreatic  duct  the  absorption  of  fat  falls  but  little  below  the 
normal;  but  after  extirpation  of  the  pancreas  the  ffeces  contain  not 
only  all  the  fat  of  the  food,  but  an  additional  quantity,  which  excess 
must  originate  in  the  system  (Lombroso). 


632  MANUAL    OF    CHEMISTRY 

INTESTINAL    SECRETIONS. 

The  intestiual  juice,  succus  entericus,  is  the  product  of  secretion  of 
numeroas  small  glands,  including  Lieberkiihn's  follicles  and  the 
solitary  glands,  throughout  the  intestine,  Brunner's  glands  in  the 
duodenum  and  upper  jejunum,  and  Peyer's  patches  in  the  ileum  and 
lower  jejunum,  to  which  may  be  added  constituents  apparently  formed 
by  the  epithelial  cells  of  the  duodenum  and  upper  jejunum.  The 
secretion  has  been  obtained  in  a  few  cases  of  intestinal  fistula  in  the 
human  subject,  and  from  animals  by  the  establishment  of  a  "Vella 
fistula,"  which  is  made  by  resecting  a  loop  of  about  2  dcm.  of  intes- 
tine, both  ends  of  which  are  sutured  to  the  abdominal  wall,  while  the 
continuity  of  the  remainder  of  the  gut  is  secured  by  joining  the  other 
two  ends. 

The  secretion  of  Brunner's  glands  may  be  obtained  individually 
from  a  duodenal  fistula  (GlaBssner).  It  differs  from  that  of  the  other 
enteric  glands  in  exerting  a  marked  proteolytic  action  in  faintly  alka- 
line, neutral  or  acid  reaction,  with  formation  of  trj^ptophane.  It  is 
alkaline,  sp.  gr.  1.005-1.020,  and  small  in  quantity,  about  1  ce.  per 
hour.    It  has  no  amylolytic  action. 

The  formation  of  the  enteric  secretion  is  intermittent,  beg^ins  to  be 
most  active  about  four  hours  after  eating,  and  continues  actively  for 
about  three  hours  thereafter.  It  may  be  provoked  or  greatly  increased 
by  electrical  or  mechanical  stimulation.  Its  quantity  is  not  definitely 
determined,  although  50-125  cc.  daily  have  been  obtained  from  an 
intestinal  fistula  in  the  human  subject  (Hamburger  &  Heckma). 

The  juice  obtained  from  the  ileum,  freed  from  mucus  by  filtration, 
is  thin,  5'ellowish,  sp.  gr.  1010-1011,  and  strongly  alkaline,  the  alka- 
linity being  due  to  carbonates,  which  cause  effervescence  on  addition 
of  an  acid.  It  contains  from  12  to  24  p/m  of  solids,  among  which 
are  albumins,  a  nucleoalburain  and  enzymes.  Of  the  enzymes  the 
most  active  are  the  invertins,  maltase  and  sucrase,  which  hjdrolyse 
maltose  and  sucrose  to  the  nionosaecharids.  Lactase  is  apparently 
absent  except  when  the  food  contains  milk  sugar.  Probably  it  con- 
tains neither  amylase,  lipase  nor  proteolytic  enzj-me.  So  far  as  enzyme 
action  is  concerned,  its  function  appears  to  be  limited  to  the  inversion 
of  the  disaccbarids  produced  by  salivary  and  pancreatic  digestion, 
although  it  is  claimed  that  a  slight  amylolytic  action  has  been  ob- 
served. 

Besides  the  secretin  (p.  626)  and  the  enterokinase  (p.  627)  men- 
tioned above,  the  epithelial  cells  of  the  upper  small  intestine  produce 
an  enzyme,  called  erepsin  (Cohnheim),  which,  although  it  has  no 
action  upon  native  albumins  or  histons.  rapidly  hydrolyses  albumoses, 
peptones  and  protamins  in  faintly  alkaline  or  neutral,  but  not  in  acid» 


THE    BILE 

reaction,  with  formatiou  of  substances  which,  like  the  peptoids,  do 
not  give  thf  bioret  reaction.  It  also  decQinpases  caseiu  similarly  and 
splits  the  nucleic  auids.  Among  the  products  of  its  action  are  ar^jiniu, 
lysin,  histidiu,  leucin,  tyrosin  and  auimuuiii.  It  does?  not  further 
dpfompose  Ihe  atnido  acids.  It  is  destroyed  by  boiling  water,  more 
slowly  at  63^,  It  is  nut  destroyed  by  acetic  acid  in  oue  hour,  but  is 
by  prolonged  contact  with  dilute  hvdroch  I  uric  acid;  and  nl<*ohol  inter- 
feres with  its  action.  It  is  not  idttotieal  witli  the  enzyme  having  a 
similar  action,  produced  by  the  pancreas.  Whether  erepsiu  acts 
JNtraeellularly  (Cohnheim)  ur  extracelluiarly  (Salaskiu),  or  in  both 
ways»  is  uu  deter  mined, 

THE    BILE. 

The  bile,  being  easily  obtained  from  the  gall  bladder,  was  early 
the  subject  of  chemical  investigation.    It  was  formerly  supposed  to 
be  actively  concerned  in  digestion,  but  it  is  now  known  that  the  diges- 
tive action  which  it  exerts  is  much  less  important  than  its  excretory 
fanetion.    It  has  no  action  whatever  upon  either  proteins  or  carbo- 
hydrates, and  its  only  digestive  utility  consists  iu  aiding  in  the  saponi- 
fication and  cmnlsification  of  the  fats,  iu  providing  a  portion  of  the 
alkali   required  to  alkalize  the  acid  chyme,  and,   indirectly  through 
emnlsification  of  the  fats,  in  acting  as  a  check  upon  bacterial  activity. 
The  bile  has  no  direct  antiseptic  action,  bnt  iu  its  absence  the  fats,  if 
present  iu  notable  amount  and  being  imperfectly  emulsitied,  meehaui- 
cally  protect  the  proteius  from  pancreatic  digestion  and  thus  reserve 
thein  for  bacterial  fenuentation  lower  in  the  intestine.   In  its  capacity 
of  emunctory  the  liver  separates  froui  the  portal  blood,  not  only  pois- 
onous substances  introduced  from  witbont,  but  also  products  of  diges- 
tion and  of  bacterial  fermentation  which  would  exert  toxic  actions  if 
l»ermitted  to  enter  the  general  circulation,  and  a  part  of  which  at 
least  is  eliminated  iu  the  bile.    The  bile  also  contains  catabolic  iirod- 
Uct8,  some  of  which,  being  insolnble  in  aqueous  liquids,  could  not 
t>e  eliminated  by  the  urirje.    But  the  bile  is  not,  like  the  urine,  a  pure 
excretion,  because,  not  only  has  it  a  certain  degree  of  utility  in  diges- 
tion, but  some  of  its  consfituciits  are  nodifted  in  the  intestine,  and 
the  products  are  reabsorbed,  to  appear  finally  in  a  modified  form  in 
the  urine. 

Human  bile  has  been  obtained  shortly  after  death  in  several 
instances  from  executed  crinnnals,  and  during  life  iu  cases  of  biliary 
fistolae  consequent  upon  cholecystostoniy.  From  animals  it  may  be 
obtained  from  permanent  biliary  fistnbe,  which  eause  no  disturbance 
in  the  nutrition  of  the  animal,  witti  food  not  too  rich  in  fats.  The 
hile  thus  obtained  from  the  gall  bladder  is  thicker,  more  cloudy  and 
of  higher  specific  gravity  than  that  secreted  by  the  liver  cells. 


f 


634  MANUAL    OF    CHEMISTRY 

The  secretion  of  the  bile  is  continuous,  but  the  quantity  produced 
varies  greatly  at  different  times  and  in  different  individuals.  In  the 
dog  the  daily  production  has  been  found  to  vary  from  2.9  to  36.4  gms. 
per  kilo  of  body  weight.  No  data  are  available  to  show  the  amount 
produced  in  24  hours  by  the  human  subject,  although  it  has  been  esti- 
mated at  500  to  950  gms.,  and  also  at  14  gms.  per  kilo  of  body  weight. 

The  bile  contained  in  the  gall  bladder  is  cloudy,  somewhat  viscid, 
alkaline,  sp.  gr.  1010  to  1040,  bitter  in  taste,  with  a  sweetish  after- 
taste, having  a  faint,  musky  odor,  particularly  perceptible  when  it  is 
heated,  and  varying  in  color  from  a  bright  golden -yellow  to  a  dark 
olive-green.     In  man  it  is  usually  yellow,  but  sometimes  green. 

Composition. — Several  analyses  of  specimens  of  human  bile  taken 
shortly  after  death  or  from  biliary  fistulae,  have  been  made,  in  which 
the  numerical  results  have  varied  within  tolerably  wide  limits  and  the 
difference  between  bladder-bile  and  hepatic-bile  are  quite  notable. 
The  proportion  of  solids  and  water  were  found  to  be:  Solids,  89.2  to 
177.3;  water,  910.2  to  822.7 for  bladder-bile;  and  solids,  22.4  to  35.3; 
water,  977.6  to  964.7  for  hepatic-bile.  The  greater  concentration  of 
the  bladder-bile,  and  its  greater  viscidity,  are  due  in  part  to  the  addi- 
tion of  mucus  secreted  by  the  bladder,  and  partly  to  absorption  of 
water.  The  solids  in  bladder-bile  consist  of:  Mineral  salts,  0.65  to 
0.77  percent;  mucin  and  biliary  pigments,  1.3  to  3.0  per  cent;  biliary 
salts,  5.6  to  10.8  per  cent;  cholesterol,  0.16  to  0.35  per  cent;  fats, 
0.3  to  0.9  per  cent;  soaps,0.6  to  1.6  per  cent,  and  lecithins  and  urea. 
In  hepatic-bile:  Mineral  salts,  0.73  to  0.99  percent;  biliary  pigments, 
0.3  to  0.53  per  cent;  biliary  salts,  0.93  to  1.82  per  cent;  cholesterol, 
0.06  to  0.16  per  cent;  fats  and  lecithins,  0.02  to  0.15  per  cent,  and 
soaps,  0.10  to  0.14  per  cent.  The  mineral  salts  consist  of  the  chlorids 
and  phosphates  of  Na,  K,  Ca,  Mg,  and  Fe,  and  NaaCOa.  Copper  is 
always  present  in  the  liver,  zinc  frequently,  and  both  may  be  found 
in  the  bile.  The  mucin  is  partly  a  true  mucin,  a  glucoproteid,  and 
partly  a  uncleoalbumin.  Urea  is  present  in  small  amount  only,  but 
is  found  in  large  quantity  in  the  bile  of  the  shark. 

Biliary  Salts. — The  bile  of  all  animals  contains  the  salts  of  conju- 
gate aniido  acids  peculiar  to  this  secretion.  They  vary  in  composition 
in  different  animals,  hut  may  be  classed  in  two  groups,  the  members  of 
one  of  wliieb  (tjlycocholic  series)  yield  glycocoll,  or  amido-acetic  afid 
(p.  413)  when  boiled  with  acids,  while  those  of  the  other  (taurocliolic 
series)  yield  taurin,  or  amido-isethionic  acid  (p.  421)  under  like 
treatment.  The  other  product  of  the  decomposition  is,  in  both  cases, 
cholic  acid,  C24H40O5,  whose  constitution  is  undetermined  beyond  the 
fact  that  its  molecule  contains  one  CHOH  group,  two  CH2OH  groups 
and  one  COOH  group.  It  crystallizes  in  oetahedra  or  in  rhombic 
prisms,  is  easily  soluble  in  alcohol,  requires  4,000  parts  of  cold,  or 


IE   BILE 


635 


[750  of  hot  wafer  for  its  solution,  is  insoluble  in  ellier,  and  becomes 
clondy  on  exposure  to  air.  In  alcoholic  sohitiou  it  is  dextrog-yrous, 
["] 0^+35°.  Its  Na  and  K  salts  are  readily  sohible  in  water; 
and  their  solutions  are  precipitated  by  lead  acetate,  or  by  barintn 
chiorid*  Cholic  acid  is  easily  oxidized  or  redneed.  On  oxidation  it 
first  loses  He  to  form  dchydrocholic  acid^  CiiHg^Os,  a  crystal! ine» 
mi)!iolms!C  acid,  sparingly  solnble,  wbicli  does  not  respond  to  the 
Pettenkofer  reaction.  This  then  takes  up  oxytjen  to  form  bilianic 
acid,  CsiH^Oa;  and  this  is  then  converted  into  a  mixture  of  chol- 
esteric  add»  Ci2Hj(j07>  pyrocholesteric  acid,  CnHiflO-.  cholanic  acid» 
r^oII-i^Ofi,  and  fatty  acids.  By  reduction,  it  yteid.s,  tirf^^  deoxycholic 
acid,  C24H40O1,  which  also  exists  in  putrid  bile;  and  then  cholylic 
acid,  CJ4H-10O2.  Two  other  acids,  related  to  cholic  acid,  have  been 
derived  trixM  huniaii  biltj»  one  choleic  acid,  Ci^lIiuOi,  possibly  idt:iitical 
with  de<ixycbolie  acid;  the  other  fellic  acid,  r-i^jH^oOi.  By  boiling 
with  acids,  and  duriug  intestinal  ferinrutalion,  cliulie  add  lusos  ILjO 
and  is  converted  ioto  an  auhydrid,  dyslysin,  Ca^HiieOii,  which  is  ainor- 
phons,  and  insoluble  in  water  and  in  alkalies. 

Besides  the  biliary  acids  of  the  glycocbolic  and  tanrochohc  g^nnips, 
au  acid  has  been  obtained  from  the  bile  of  the  shark  (IJammarsteu) 
which  possibly  represents  a  tbird  ^roup.  It  contains  sulfur,  and  on 
hydnilysis  by  JICl  it  yields  sulfuric  acid.  It  therefore  probably  has  a 
constitution  similar  to  that  of  the  sulfo-cunjugate  acids  of  the  nrint- . 

Cliulic  acid  ami  tlie  conjugate  acids  containing  it  gWv  the  Petten- 
kofer, Hi'  furfurole,  reaction  :  on  additiun  of  a  ft^w  drops  of  cane-sugar 
sohiticMi  and  then  of  concentrated  HaSO^,  the  temperature  being  kept 
down  to  about  70"^,  the  solution  beco-mes  turbid,  and  suon  assumes  a 
fine  purple  color.  The  colored  liquid,  snffii'iently  diluted  with  acid, 
gives  a  spectrum  of  two  bauds,  one  at  F,  the  otiier  between  D  and  E, 
near  to  E.  Many  other  substances  give  the  Pettenkofer  reaction : 
Albumins,  phenols,  polyatomic  alcohols,  morphin,  oleic  acid,  salicylic 
acid,  etc.;  therefore,  it  is  only  indicative  of  tljc  presence  of  bile  salts, 
if  these  have  been  separated  by  extraction  of  the  dried  substance  by 
alcohol  and  precipitation  by  ether.  With  H2SO4  alone  at  the  ordinary 
temperature,  sohiiions  of  the  biliary  acids  are  colored  reddish -yellow, 
with  a  green  tlu<irescence. 

The  biliary  acids  are  obtained  from  the  bile,  dried  with  animal 
charcoal,  by  extraction  with  strong  alcohol  and  preciiiitation  by  addi- 
tion of  ten  vohimes  of  anhydrous  ether*  On  standing,  tlii^  gummy  pre- 
cipitate of  sodium  salts  becomes  crystalline  in  whole  or  in  part.  These 
are  collected  and  dissolved  in  water.  Neutral  lead  acetate  is  added  to 
the  solution,  which  precipitates  lead  gtycocholate ;  and  from  the  fiUrate 
lead -tJiurochol ate  is  precipitated  by  ammonia.  The  separated  lead 
aalts,  suspended  in  water,  are  decomposed  by  HgS,  the  aqueous  solution 


636 


MANUAL    OF    CHEMISTRY 


filtered  off,  and  evaporated  to  dryness.  The  acids  are  then  dissolved 
in  sraall  volumes  of  absolute  alcohol  and  precipitated  by  anhydi*ous 
ether*  and  purified  by  repetition  of  solution  in  alcohol  and  precipita- 
tion by  ether, 

Glycocholic  Acid— C26H43NO(r — predominates,  in  its  sodium  salt, 
in  human  bile  and  in  that  of  the  ox,  but  is  absent  in  that  of  the 
carnivora.  It  crystallizes  in  silky  needles,  soluble  in  300  parts  of 
cold,  and  120  parts  of  hot  water,  ensily  soluble  in  alcohol,  insoluble 
in  ether,  which  precipitates  it  from  its  alcoholic  solution.  Its  taste  ia 
at  the  same  time  bitter  and  sweet.  In  alcoholic  solution  it  is  dex- 
trogyrous  [^]n^+29*^.  Its  Na  salt  is  much  more  soluble  in  water 
than  the  free  acid,  and  its  solutions  are  precipitated  by  (C2H302)2Pb, 
CuS04,  Fe^Cle,  or  AgNOj.  When  heated  with  alkalies  or  dilute  acids,. 
glvfocholie  acid  is  decomposed  into  cholic  acid  and  glycocoll,  C26H43* 
>T>(i+ni;0=024ll4.>Of.+CH2{NIl5)  COOIL  Heated  with  concentrated 
HaHOi  it  loses  water  to  fonu  cholonic  acid,  C20H41NO5. 

Taurocholic  acid  — C'ieHj^NSOT^exists*  as  its  sodium  salt,  in 
human  liile  and  in  that  of  the  carnivora,  in  much  less  amount  in  that 
of  the  herbivora*  It  is  very  soluble  in  water  and  in  alcohol,  insoluble 
in  ether.  It  crystallizes  with  difficulty  in  silky  needles  by  precipita* 
tiou  of  its  solution  in  absolute  alcohol  by  anhydrous  ether.  These 
crystals  rapidly  deliquesce  to  an  amorphous,  resinous  mass  on  ex- 
posure to  air.  Its  taste  is  bitter  and  sweet.  In  alcoholic  solution  it 
is  Ifevogyrous,  Me^  — 24.5°.  Its  sodium  salt  is  very  soluble,  and 
its  solutions  are  not  precipitated  by  the  salts  which  precipitate  with 
glycocholic  acid,  but  it  is  precipitated  by  basic  lead  acetate.  Heated 
with  alkalies  or  dilute  acids,  or  even  on  evaporation  of  its  aqueous 
solution,  taurocholic  jicid  is  decomposed  into  cholic  acid  and  taiirin: 
C20H45NSO7+H2O  =  C:mHio05  +  CILjCXH^) .Cll^.SOall,  Solutions  of 
taurocholates  and  of  glycocholates  dissolve  cholesterol  and  alkaloids, 
if  the  salt  be  in  excess.  They  emulsify  oils  and  peptone  solutions. 
They  precipitate  albumins  and  albumoscs. 

Biliary  Pigments. — The  bile  uf  all  auimuls  contains  peculiar  pig- 
ments, which  are  derivatives  of  the  blood -coloring  matter.  The  most 
important  are  bilirubin  and  biliverdin, 

Btlirubin,  t^t-2lI:«N406,  occurs  in  its  sodium  salt  in  the  bile  of  all 
vertebrates,  particularly  in  that  of  the  herbivora,  in  the  intestinal 
contents,  in  biliary  calculi  (as  its  calcium  salt),  and,  pathologically, 
in  the  urine,  blood,  and  tissues,  and,  crystallized  as  ''h>t*matoidin."  in 
ohi  extravasations  of  blood.  It  forms  either  an  Hmorpliouts,  reddish- 
yellow  powder,  or  scarlet  crystals,  or,  when  crystallized  by  spontaneous 
evaporation  of  its  chloroform  solution,  reddish  -  yellow  rliombic  plates. 
It  is  insoluble  in  water,  sparingly  soluble  in  alcohol  or  in  ether,  readily 
soluble  iu  chloroform,  carbon  disulfid,  benzene,  and  in  alkaline  solu- 


I 


4 


-^ 


THE    BILE 


6^7 


tintis.  Towards  bases  it  behaveii  like  n  phenol,  form  in  g  soluble  salts 
with  the  alkuJi  iiielals,  and  insoluide  or  sparingly  soluble  ones  with 
those  of  the  alkaline  earths.  It  has  great  piginentarj^  power,  but  its 
solutions  give  no  spectrum.  If.  Ijowever,  its  alkaline  solutions  be 
treated  witli  ammonia  in  excess  and  zinc  chlorid,  they  eliange  in  color 
to  deep  orange  and  then  to  green,  and  then  give  a  spectrum  of  a  single 
band  near  C,  and  between  C  and  D.  When  reduced  by  zinc  dust  or 
by  HI,  bilirubin  yields  hfi^mopyrrole  (p,  510),  By  the  action  of  sodium 
amalgam  upon  a  solution  of  bilirubin  in  weak  alkali  the  liquid  becomes 
opaque,  and,  after  two  or  three  days,  turns  brown,  when  upon  addition 
of  HCl,  it  turns  red  and  deposits  brown  floeculi  of  a  substance  which 
closely  resembles,  if  it  is  not  identical  with,  the  stercohilin  of  the  ftvces 
and  the  urobilin  of  the  urine.  This  sulistance,  which  is  ealled  hydro- 
bilirubin,  C:f2HioN407,  is  formed  from  bilirubin  by  hydrogenation,  fol- 
lowed by  oxidation  of  its  solution  in  airr  C;rjn;mN»06"|-3H2H-0-=C32- 
II40N4OT+H2O.  Solutions  of  biliruV>in  salts  on  exposure  to  air  soon 
become  green  from  formation  of  biliverdin  by  oxidation. 

The  reactions  of  bilirubin  are  utilized  for  the  detection  of  bile  in 
the  urine  and  elsewhere.  They  are:  (1)  GnifUn's  rfaetimt — The 
liqntil  examinecl  is  floated  upon  the  surfaee  of  nitric  acid  containing 
a  lirtle  nitrous  acid,  when  a  series  of  colors,  green,  blue,  violet,  and 
reddish-yellow,  are  produced  at  the  union  of  the  two  layers,  of  which 
the  green  is  the  juost  marked.  There  must  I3©  no  alcohol  present. 
Limit  1 ; 80, 000.  This  reaction  depends  upon  a  progressivt*  oxidation, 
with  formation  of  the  following  products:  («)  biliverdin;  {b}  bill- 
cyanin,  whose  neutral  solutions  are  of  a  flue  idue  eoior,  with  red 
tluorescence,  and  whose  alkaline  solutions  are  green,  and  give  a  spec- 
trum of  three  bands,  one  between  C  and  D,  nearer  to  C,  one  over  D, 
and  the  third  near  to  E,  between  E  and  F;  (t)  a  red  pigment,  the 
nature  of  which  has  not  been  determined;  (4)  choletelin^  a  brownish* 
yellow  pigment,  whose  alcoholic  sohition  gives  a  spectrum  of  one 
band  between  E  and  P,  (2)  HammarHfen'ii  reartmn — The  reagent 
used  is  made  by  mixing  1  vol.  HNO:j  with  VJ  vols.  HCl,  and  letting 
the  mixture  stand  until  it  is  yellow.  A  colorless  liquid  is  formed  by 
mixing  1  vol.  of  this  reagent  with  4  vols,  of  alcohol,  which  is  colored 
intensely  green  by  a  trace  of  bilirubin.  (3)  Hupperfs  reaction — The 
liquid  is  treated  with  barium  chlorid  and  ammonia;  and  the  preeip- 
ituti^  formed  is  washed  with  water,  and  covered  while  still  moist  in  a 
test-tnbe  with  alcohol  and  acidulated  with  hydrochloric  aeid,  Tlie 
mixture  is  then  heated  to  boiling,  w^hen,  in  presence  of  bilirubin,  it 
becomes  emerald  green. 

Biliverdin — C:i2H;iaN40H — accompunies  bilirubin  in  bhidder-bile, 
but  not  in  hepatic -bile,  and  is  most  abundant  in  green  biles.  It  is 
amorphous,  insolnble  in  water,  ether  or  chloroform,  soluble  with  a 


i 


638 


IdANUAL 


SMISTR^ 


green  color  in  alcohol  and  in  glacial  acetic  acid,  or  withabrowu  color 
in  alkalies.  It  is  precipitated  from  its  solutions  by  acids  and  by  salts 
of  Oa»  Ba,  and  Pb,  It  responds  to  the  tests  for  bilirubio.  Its  alco- 
holic solution,  tE*eatetl  with  aTumoniaeal  ZnCb*  sliows  a  green  fluores- 
cence. Reduemg  agents  convert  it  into  bilirubin;  oxidizing  agents 
into  biliverdic  acid,  C^iH^NOi.  It  is  best  obtained  by  oxidizing 
bilirubin. 

Bilifuscin  is  a  brown,  amorphous  pigment,  oecorrmg  in  biliary 
calculi  and  in  putrid  bile,  which  is  soluble  in  alcohol  and  in  alkalies, 
insoluble  in  water,  ether  or  chloroform.  It  does  not  respond  to  the 
Gmelin  reaction.  Biliprasin  is  the  name  given  to  a  green  pigment 
occurring  in  biliary  calculi,  which  is  probably  a  mixture  or  combina- 
tion  of  bilirubin  and  biliverdin.  Bilihnmin  is  a  brown,  amor- 
phous pigment,  obtained  from  biliary  calculi,  which  is  insoluble  iu 
alcohol,  ether  or  chloroform,  and  which  does  not  give  the  Omelin 
reaction. 

Cholesterol  ^Cholesterin^ — C27H45OH  —  is  a  monoatomic  alcohol 
of  unknown  constitution,  which  exists  normally  in  almost  every 
animal  tissue  and  fluid,  in  many  in  very  minute  quantity,  most  abun- 
dantly in  the  bile,  nerve  tissues,  intestinal  contents,  fseees,  and  in 
sebum  and  wool*fat.  In  pathological  products  it  is  frequently  an 
abundant  constituent,  and  is  met  with  in  biliai'y  calculi,  certain  brain 
tumors,  atheromatous  degenerations^  pus,  the  fluids  of  cysts,  hydro- 
cele, etc.,  as  well  as  in  cancerous  and  tubercular  deposits,  and  iu 
the  lens  in  cataract.  In  some  of  these  situations  it  exists  free,  in  its 
peculiar,  crystalline  form  of  very  thin,  colorless,  rhombic  plates,  while 
in  others  it  is  in  combination  in  the  form  of  its  esters.  It  also 
exists  in  the  vegetable  world,  widely  distributed,  notably  in  peas, 
beans,  olive* oil,  wheat,  etc. 

Cholesterol  is  insoluble  in  water,  in  alkalies,  or  in  dilute  acids, 
difficultly  soluble  in  cold  alcohol,  readily  soluble  in  hot  alcohol,  ether, 
benzene,  acetic  acid,  glycerol,  and  solutions  of  the  biliary  acids.  It 
is  odorless  and  tasteless;  f.  p*  145"^;  sp.  gr.  1.046.  It  is  IsBvogyrous, 
Md^  — 31.6*^^  in  any  solvent.  It  combines  readily  with  volatile 
fatty  acids,  and  from  its  solution  in  glacial  acetic  acid  n  com- 
pound, C27H45O.C2H3O2,  crystallizes  in  fine  curved  needles,  which 
are  decomposed  on  contact  with  water  or  alcohol.  When  heated 
with  acids  under  pressure,  it  forms  true  esters,  some  of  which  also 
exist  in  wool -fat,  and  in  "lanolin,"  derived  therefrom.  By  oxida- 
tion it  yields  a  series  of  acids,  from  cholesteric  acid,  CwHwOi — not 
identical  with  the  acid  of  the  same  name  derived  from  cholic  acid 
(p.  635) — to  trioxycholesteric  acid,  C2eH4407. 

Cholesterol  may  be  recognized  by  the  following  characters:  (1) 
Its  chrystaUine  form,  thin  rhombic  plates,  usually  having  one  obtuse 


THE    BILE 


G31) 


angle  missia^.  (2)  If  these  crystals  be  moistened  witli  dilute  H2SO4 
(1:5)  they  are  colored,  first  bright  earmine,  and  then  violet ^  begin- 
ning at  the  borders.  If  iodin  solotion  be  now  added,  the  color 
changes  to  bluish -green,  then  to  blue.  (3)  When  H2SO4  is  added  to 
a  solution  of  cholesterol  in  chloroform,  the  liquid  is  colored  purple, 
changing  during  evaporation  to  bhie^  green  and  yellow  (Salkowski), 

(4)  If  acetic  anhydrid  be  added  to  a  chloroform  solution  of  choles- 
terol, and  then  a  drop  or  two  of  concentrated  H2SO4,  the  mixture 
becomes  first  red,  then  blue,  and  finally  green  (Liebermanu-Burchard). 

(5)  When  a  mixture  of  2-3  vols,  of  H2HO4  or  HCl  and  oue  vol.  of 
dilute  PezCle  solution  is  evaporated  upon  cholesterol,  a  residue  is 
obtained  which  is  at  first  purple,  then  violet  (Schiff).  (6)  When 
moistened  with  concentrated  HXO3  and  the  liquid  evaporated,  choles- 
terol leaves  a  yellow  residue,  which  is  colored  dark  orange -red  by 
NH4HO  or  NaHO  (see  Murexid  Reaction,  p,  530).  (7)  Pure,  dry 
cholesterol,  moistened  with  propionic  anhydrid  and  dried  and  fused, 
leaves  a  residue  which  on  cooling  becomes  first  violet,  then  blue, 
green,  orange,  carmine-red,  and  finally  copper  colored  (Obermiiller), 

Isocholcsterol  has  the  formula  C2eH430II,  formerly  assigned  to 
cholesterol.  It  occurs  in  wool -fat,  accompanying  cholesterol,  from 
which  it  differs  in  its  f,  p.  —138°  (280.4°  FJ,  and  in  not  responding 
to  the  Salkowski  reaction. 

Origin  and  Destiny  of  the  Biliary  Constituents.  —  The  biliary 
salts  are  produced  in  the  liver,  and  do  not  preexist  in  the  blood. 
This  is  proven  by  the  facts  that  they  do  not  accumulate  in  the  blood 
after  extirpation  of  the  liver  in  frogs,  and  that  in  dogs  they  are 
absorbed  by  the  lymphatics  of  the  liver  and  carried  to  the  blood  by 
the  thoracic  duet  after  ligation  of  the  ductus  choledoehns,  but  they  do 
not  appear  in  the  blood  after  ligation  of  both  ductus  choledochus  and 
thoracic  dnct.  Although  the  immediate  antecedents  of  the  biliary 
salts  are  not  known,  they  are  probably  formed  by  union  of  their 
constituents,  which  are  derived  from  different  sources.  Cholic  acid, 
containing  neither  nitrogen  nor  sulfur,  and  containing  both  alcoholic 
and  carboxyl  groups,  is  in  all  probability  derived  from  a  carbohy- 
drate, or  possibly  from  the  fats.  There  is  also  evidence  that  it  may 
be  derived  from  cholesteroL  If  defibrinated  blood  holding  finely  divided 
cholesterol  in  suspension  and  glycocoU  in  solution  be  injected  into 
the  portal  vein  of  a  dog^  the  blood  of  the  hepatic  veins  responds  to 
Pettenkofer*s  reaction,  although  it  did  not  do  so  previous  to  the  injec- 
tion. The  action  would  involve  an  oxidation  and  a  synthesis.  When 
cholic  acid  is  injected  into  the  circulation  of  dogs  the  formation  of 
taurocholic  acid  is  temporarily  increased.  GlycocoU  and  taurtn  both 
contain  nitrogen,  and  the  latter  sulfur  also.  They  are,  consequently, 
derived  from  the  proteins.     GlycocoU  is  one  of  the  principal  products 


640 


MANUAL    OF    CHKMISTRV 


of  Lydrol3*sis  of  collagen  iiutl  otlitn-  albiituiiioitl.s^  unci  is  a  decomposi- 
tion product  of  most  proteiDS.  Most  probably  tauriu  origiuates  from 
the  proteins  tliroui^b  eystin  and  cysteiu  aeid  (p,  421,  422).  Although 
the  sulfur  coutetit  of  the  bile  is  not  inereased  by  admiuistratioQ  of 
cystia  aloue,  it  is  iuoreaaed  by  admiuistratiaii  of  cystiii  aud  ehoHc  acid. 
The  biliary  salts  are  not  reabsorbed  uiiehauged  from  the  intestine 
under  normal  eireninstanees,  or,  at  all  events,  not  in  any  notable 
quantity.  Hoiulions  of  these  salts,  when  injeeted  into  the  circulation, 
are  rather  active  poisons.  In  small  doses  they  cause  dimiuutioii  in 
the  frequency  of  the  pulse  and  of  the  respiratory  movements,  lowering 
of  the  temperature  and  arterial  tension,  and  disintegration  of  the 
blood-corpuscles.  In  large  doses  (2-4  gm.  to  a  dog),  they  produce 
the  same  effects  to  a  more  marked  degree,  and,  further,  epileptiform 
convulsions,  black  and  bloody  urine,  and  death.  Similar  effects,  com- 
plicated with  others  referable  to  tlie  biliary  pi*fments,  are  observed 
when,  in  consequence  of  obstruction  of  the  bile  duct,  the  bile  is 
absorbed  through  the  lymphatics.  These  effects  do  not  follow  the 
iujection  of  the  products  of  decomposition  of  tlie  biliary  acids,  except 
choHe  acid,  and  with  that  the  symptoms  are  much  less  marked.  Nor 
are  the  biliary  salts  found  as  such  in  the  f«?ces,  except  that  thes« 
occasionally  contain  glycocholic  acid,  but  never  tanrocholic  acid,  which 
is  more  readily  decomposed.  8oinetimes  cholic  acid  or,  more  frequently, 
dyslysin  occurs  in  tlie  fteces,  but  not  glycocoll  or  tanrin.  The  decom- 
position of  the  biliary  salts  which  occurs  in  the  intestine  is  due  to  fer- 
raentattv^e  (bacterial)  action,  as  the  contents  of  the  lower  intestine  in 
the  foetus  contain  notalde  quantities  of  biliary  salts.  That  the  taurin 
resulting  from  the  decomposition  is  reabsorbed  is  demonstrated  by  the 
fact  that  it  appears  in  the  urine,  partly  in  its  own  form,  its  sulfur 
partly  oxidized  to  sulfates,  and  partly  as  taurocarbanHC  acid,  formed 
by  the  union  of  tanrin  and  carbamic  acid:  C2ll7N803+C02NH3^CV 
HgNzSO^+HaO,  Equally  direct  proof  of  the  reabsorption  of  glycocoll 
is  not  at  hand^  but  the  ready  formation  of  nric  acid  (p.  529)  and  of 
hippurieacid  (p.  479}  from  glycocol!  render  it  probable  that  the  latter 
substance  is  an  intermediate  product  in  the  formation  of  the  other 
two,  in  part  at  least,  as  well  as  of  urea  in  the  economy. 

The  biliary  pigments  are  also  formed  in  the  liver,  and  do  not 
preexist  in  the  blood,  although  bilirubin  at  least  may  be  formed  in 
other  parts  of  the  body,  and  has  been  found  in  old  extravasations  of 
blood,  and  in  the  placenta.  The  formation  of  these  pigments  in  the 
liver  is  proven  by  the  following  facts:  in  pigeons,  the  biliary  pig- 
ments make  their  appearance  in  the  blood  in  five  hours  after  ligation 
of  the  bile-ducts;  but  if  the  blood-vessels  of  the  liver  are  ligated  at 
the  same  time,  no  pigments  appear  in  the  blood  or  tissues  in  24 
hours.     In  geese,  poisoned  with  hydrogen  arsenid,  the  biliary  pig^ 


THE    BILE 


641 


I 


meDts  appear  in  the  urine  in  hirge  quiintifcy;  but  if  the  liver  have 
been  extirpated  before  the  poisDiiiug  this  does  not  occur. 

The  parent  substance  of  the  biliary  pigments  is  undoubtedly  the 
blood  coloring  matter.  If  hif ino^lohin  in  solution  be  iujected  into  the 
cirrulalion  of  an  animal  in  sainll  qaantity,  the  amount  of  bilirnbin 
produced  is  increased,  but  the  uriue  contains  neither  bile-  nor  blood- 
pigment,  nor  does  jauiidiee  result.  If  the  quantity  of  bt^moglobin 
injected  be  increased  progressively,  at  first  so-called  hfematogenic 
icterus  is  produced,  from  reubsorptiou  of  the  bilirubin,  produced  in 
excessive  amount,  by  the  hepatic  lymphatics,  and  the  bile -pigment, 
but  no  blood  pigment,  api>ears  in  the  urine.  Finally,  with  larger 
quantities  of  hromoglobin^  jaundice,  cbolnria  and  bann^jglolnuuria  all 
result,  A  similar  condition,  dne  to  the  same  cause,  is  observed  iu 
poisoning  by  hydrogen  arsenid  and  by  phosphorus,  in  which  there  is 
extensive  disintegration  (if  red  lilood -corpuscles,  f<dIowed  by  snlntiou 
of  the  liberated  luemoglobiu  iu  tlie  plasiiui,  and  tlie  appearance  of  the 
symptoms  above  noted.  Tbe  chemical  relationship  between  bilirubin 
and  certain  derivatives  of  ba^nroglobin  is  very  close.  Indeed,  bilirubin 
is  identical  with  htematoidin,  which  is  found  iu  old  blood  stains,  and, 
in  the  crystalline  form,  iu  old  extravasations  of  blood.  Bitirubiu  is 
also  isomeric  with  bamuitoporpbyrin,  a  pigtnent  normally  present  in 
the  urine  iu  small  amount,  and  notably  increased  therein  in  poisoning 
by  sulfonaL  The  relation  between  ha?matin  and  bilirubin  is  shown  by 
the  equation:  Ca2H:riN4Fe04+2H-.>0=Cri2H3oN40a+Fe,  which  may,  in 
some  modified  form,  indicate  the  method  of  formation  of  the  biliary 
pigment.  The  ij-on  thus  liberated  has  been  accounted  for  only  in 
part.  The  bile  always  contains  iron,  principally  iu  the  form  of  ferric 
phosphate,  to  the  proportion  of  from  0,04  to  0.115  p/m.  But  the 
Carres pon deuce  between  the  amount  of  iron  present  and  the  amount 
of  bilirubin  formed,  which  the  above  equation  would  call  for,  has  not 
been  found  to  exist*  For  100  parts  of  bilirubin  present  in  the  bile, 
1.4  to  1.5  parts  of  iron  have  been  founds  whereas  an  equivalent  quan- 
tity of  hiematiu  would  yield  9  parts.  Moreover,  in  poisoning  by 
hydrogen  arsenid,  iu  which  there  is  an  increased  fortnation  of  bile 
pigment,  no  corresponding  increase  iu  the  amount  of  iron  in  the  bile 
lias  been  observed.  Undoubtedly  the  iron  thus  unaccounted  for  in 
the  bile  goes  to  tbe  formation  of  tbe  iron -containing  proteins  of  the 
liver  cells,  from  which  hfemoglobin  may  probably  be  regenerated 
(p.  679). 

There  is  no  correspondence  in  the  observed  variations  in  the 
Quantities  of  biliary  salts,  and  of  biliary  pigments  formed.  As  these 
variations  take  place  independently  of  each  other,  the  processes  of 

I  format  ion  of  the  two  classes  of  substances  may  be  considered  as  being 
distinct  from  each  other. 


I 


41 


642  MANUAL    OP    CHEMISTRY 

The  biliary  pigments  are  not  reabsorbed  unchanged  in  health. 
When  they  are  pathologically  (icterus,  phosphoms  poisoning)  they 
stain  the  skin  and  tissues,  and  make  their  appearance  in  the  urine. 
The  coloring  matter  of  the  feeces,  stercobilin,  and  at  least  one  of 
those  of  the  urine,  urobilin,  are  derived  from  bilirubin  (p.  725). 

Cholesterol  exists  in  the  protoplasm  of  all  cells,  and  is  particu- 
larly abundant  in  nerve  tissues.  In  analyses  of  brain  substance  it 
has  been  found  to  constitute  a  large  portion  of  the  solid  constitnents 
of  both  white  and  gray  matter,  particularly  of  the  former.  It  is  con- 
stantly present  in  the  faeces  in  its  own  form  or  in  that  of  a  derivati?© 
(koprostearin,  stercorin),  and  only  appears  in  the  urine  in  chyluria. 
It  is,  in  all  probability,  a  catabolic  product  produced  principally  in 
nervous  tissues. 

Biliary  Calculi. — Calculi  are  frequently  met  with  in  the  gaD 
bladder  after  death,  and  the  smaller  ones  often  pass  into  the  intestine 
during  life.  These  calculi  may  be  divided  into  three  classes,  accord- 
ing to  the  nature  of  their  cliief  constituents  :  (1)  Pigmentary  cakuU, 
consisting  chiefly  of  the  several  pigments  mentioned  above,  combined 
with  calcium,  and  sometimes  associated  with  calcium  salts.  They  are 
usually  multiple,  sometimes  very  numerous.  They  are  yellow,  green, 
brown  or  black  in  color;  sometimes  rounded  and  nodulated  npon 
their  surfaces,  more  usually  having  flattened  surfaces,  and  more  or 
less  perfect  geometrical  shapes,  produced  by  attrition  one  against  the 
other.  In  cattle  these  stones  are  sometimes  found  as  large  as  a 
walnut.  (2)  Cholesterol  calculi,  consisting  almost  entirely  of  choles- 
terol. They  are  usually  single,  rounded  and  polished,  having  a 
nacreous  appearance  and  an  ovoid  outline.  They  may  measure 
nearly  an  inch  in  their  longer  diameter.  (3)  Calcic  calculi  are  much 
more  rare  in  the  human  subject  than  the  other  two  forms.  They 
consist  mainly  of  tricalcic  phosphate  and  calcium  carbonate. 

CHEMICAL    CHANGES    OCCURRING    IN    THE    INTESTINE. — ^ABSORPTION. 

The  changes  which  the  constituents  of  the  food  undergo  in  the 
alimentary  canal  are  the  sum  of  the  eflPects  produced  by  the  several 
digestive  secretions,  modified  by  their  influences  upon  each  other's 
actions,  and  the  chemical  reactions  set  up  by  bacterial  life,  constantly 
present  and  active.  The  changes  in  the  organic  food -constituents, 
carbohydrate,  fatty  and  protein,  are  briefly  the  following: 

Carbohydrates. — The  araylolytic  action  of  the  ptyalin  of  the  saliva 
upon  hydrated  starch  is  arrested  by  the  acid  reaction  of  the  gastric 
contents,  but  may  continue  for  some  little  time  in  the  stomach  in  the 
interior  of  difficultly  permeable  masses  of  starchy  foods,  particularly 
as  a  certain  degree  of  acidity  is  required  to  arrest  the  action.    But 


CHEMICAL   CHANGES   OCCUERIXG   IN    THE   INTESTINE 


643 


once  arre^leil,  it  is  not  reestaulit^lied,  feo  far  ns  fciulivary  aeliou  is 
couceriied,  when  the  rettcliou  returus  to  alkaline  iu  the  intestine,  la 
the  iutes title  the  powerful  diastatic  action  of  the  paiiereatie  etizyme, 
favored  by  the  preseuee  of  tlie  bile,  takes  the  place  of  salivary  aetiuii 
and  eotititiues  the  amylolytie  hydrolviiis  through  ajnyludextrin,  the 
erythi'odextrius  and  achroodextrius  to  the  formation  of  disaccharids, 
Glycugen  is  also  deeoiuposed  to  maltose  and  isomaltose.  luversion  of 
the  disaeeharids,  caue-su^ar,  mtlk -sugar,  maltose  and  isonialtose,  is 
effected  by  the  iuvertios  of  the  intestinal  secretion,  and  also  by  bau' 
terial  action.  Even  eeltulose,  if  finely  divided,  is  to  some  extent  eon- 
verted  into  soluble  derivatives  In  the  intestine,  piobably  by  bacterial 
action. 

Bacterial  action  in  the  alimentary  canal  is  exerted  chiefly  upon  the 
carbohydrates  in  the  small  intestine,  and  upon  the  proteins  in  the 
large  intestine.  Normally  bacterial  activity  is  held  in  check  in  the 
stomach  by  the  germicidal  action  of  the  acid  of  its  secretion,  and  it  is 
only  when  this  is  iu  abeyance,  as  in  anachlorhydria,  that  gastric  fer- 
mentations occur.  But  the  entire  intestinal  tract  is  inhabited  by  a 
bacterial  flora  of  considerable  variety,  and  active  bacteria  have  been 
found  as  high  as  2  em*  in  the  pancreatic  duct  in  dogs.  In  the  large 
intestine  bacteria  are  mnch  more  numerons  than  in  the  small  intestine, 
and  their  numbers  and  activity  are  inversely  proportionate  to  the 
activity  of  peristalsis.  It  has  been  claimed  that  the  flora*  of  the  two 
divisions  of  the  gut  are  distinct,  that  the  bacteria  of  the  small  intes- 
tine  find  entrance  by  the  mouth,  those  of  the  large  intestine  by  the 
anus,  and  that  neither  pass  the  ileo*ccecal  valve.  It  has  also  been 
claimed  that  the  presence  of  bacteria  in  the  intestine  is  essential  to 
life.  As  it  is  impossible  to  disinfect  the  intestine,  once  bacteria  have 
found  lodgment  therein,  without  at  the  same  time  destroying  the  life 
of  the  host,  this  question  can  only  be  deterjnined  by  observations 
upon  animals  born  and  reared  aseptically.  Althongli  the  results  are 
jt  en t lively  conclnsive,  observations  made  with  chicks  and  with 
linea-pigs,  tlie  latter  born  byeirsarian  section,  appear  to  show  that, 
while  the  development  of  the  aseptic  young  is  not  radically  interfered 
witli,  it  is  not  so  rapid  as  that  of  the  control  animals.  Bacterial 
decomposition  of  the  carbohydrates  takes  place  almost  entirely  in  the 
fimall  intestine*  In  its  earlier  stages,  with  starches,  dextrins  and 
disaccbarids,  the  products  are  the  same  as  those  formed  by  the  diges- 
tive enzymes.  But,  particularly  with  celhilose,  wiiich  escapes  digestion 
by  the  secretions  of  the  host,  the  changes  readily  proceed  further  by 
alcoholic,  acetic,  lactic  and  butyric  fermentations  set  up  by  tbc  corre* 
spondiog  ferments.  The  contents  of  the  lower  ileum  contain  alcohol, 
and  are  acid  from  the  organic  acids  mentioned,  as  well  as  snccinic 
and   paralactie   acids   and  biliary  acids.    In    butyric  fermentation, 


644 


MANTAL    OF    CHEMISTRY 


whether  direct  from  glueose  or  ihroiigh  laetie  acid,  naacent  hydrogen 
is  prudueed:  CeHi20e=C4Ha02+2COLiH-2H2,  which  effects  certain  re* 
ductioDs  oeeurriug  in  the  intestine,  as  that  of  hiliruhin.  Although 
the  saliva  of  dogs  contains  no  ptyalin,  these  animals  after  extirpation 
of  the  pancreas  are  still  capable  of  assirnilattiig  from  40  to  70  per 
cent  of  starch  ingested,  whose  hydrolysis  must  he  accomplished  by 
bacterial  action  or  by  that  of  enteric  secretions*  unless,  as  has  been^ 
claimed,  the  stomach  of  these  animals  secrete  an  amylase  acting  in 
acid  solntion. 

When  excessive  quantities  of  sugars  are  taken,  absorption  does 
not  keep  pace  with  inversion,  bacterial  fermentations  become  more 
active^  and  the  irritating  qnality  of  the  aeids,  produced  in  abnormally 
large  amonnt,  causes  in(!E*eased  peristalsis  and  diarrlja?a.  Starch,  when 
taken  in  excess,  does  not  produce  these  results,  but  the  excess  is  elim- 
inated unchanged  in  the  ftFces. 

Polysaecharids  can  only  be  absorbed  after  hydrnl3'sis  at  least  to 
the  stage  of  disaceharids.  Lactose  and  saccharose  do  not  occnr 
normally  in  the  blood,  and  when  injected  into  the  circulation  are  not 
utilized,  but  are  eliminated  in  the  urine  as  foreign  material.  To  be  of 
service,  therefore,  the  hydrolysis  must  proceed  to  the  stage  of  mouo- 
saccharids,  either  in  the  intestine  or  iu  its  epithelium,  through  which 
the  products  of  carbohydrate  digestion  an?  absorbed  into  the  blood. 
The  absorption  of  glucose,  wbich  requires  no  preliminary  digestive 
treatment,  is  more  rapid  tlian  that  of  the  disaeeharids,  and  of  the  lat- 
ter, maltose  and  saccharose  are  more  rapidly  inverted  and  the  prod- 
ucts absorbed  than  is  the  case  with  lactose. 

Fats. —  The  only  known  chemical  change  which  the  fats  undergo 
during  digestion  is  a  not  very  abundant  saponification  to  glycerol  and 
fatty  aeids  by  the  pancreatic  enzyme,  and  possibly  also  by  a  gastero- 
steapsin.  The  liberated  fatty  aeids  in  part  combine  with  the  alkali  of 
the  pancreatic  juice  and  the  bile  to  form  soaps,  which  aid  in  the  con- 
version of  the  remainder  of  the  fats  into  a  fiue  emulsion,  in  which 
form  they  are  absorbed  through  the  lacteal s  and  thoracic  duct  into 
the  blood*  A  small  proportion  of  fat  is  also  saponified  in  the  lower 
small  intestine  by  bacterial  action,  and  by  the  same  agency  the  le- 
cithins are  split  to  glycerophosphoric  acid,  cholin  and  fatty  acids. 

The  glycerol,  fatty  acids  and  soaps  resulting  from  the  hydrolysis  iif 
the  fats  and  lecithins,  and  the  glycerophosphoric  acid  from  the  lecithins 
are  in  great  part  absorlied  through  the  epithelium  of  the  small  intestine, 
and  are  probably  utilized  in  the  synthetic  regeneration  of  fats  in  the 
organism.  The  cholin  from  the  lecithins  is  decomposed  by  bacterial 
action  into  (::'02.  CH4  and  NH-,. 

The  degree  of  perfection  of  absorption  of  fats  may  be  estimated  by 
determining  the  -'loss,''  i.  e,,  the  fraction  of  the  ingested  fat  present 


: 


CHEMICAL   CHANGES   OCCUKRING   IN   THE    INTESTINE 


645 


in  the  tVvees.  This  *Moss**  does  not  represent  strietly  tlie  amount  of 
ingested  fat  which  has  escaped  absorption,  as  appreeiable  quantities 
are  dischurged  into  the  intestine  with  the  seeretioiis  mid  epithelinio. 
The  loss  is  the  greater  as  the  fusing  point  of  the  fat  is  higher.  Thus 
with  olive  oil  it  is  2.3  per  cent,  with  nmtton  talhi«%  f*  p.  49^ »  7 A  per 
cent,  and  with  pure  stearin,  f.  p.  60^,  i)0  per  cent.  When  the  1ob8 
exceeds  30  per  cent  t!ie  existence  of  dtstnrhanee  of  fat  a.ssitnilation 
may  be  suspected.  With  excessive  peristalsis  the  h)ss  rnny  he  40  per 
eeut  with  normal  secretion  of  bile  and  pancreatic  juice.  With  nnconi- 
plieiited  exclusion  of  bile  from  the  intestine  it  reaches  4.1  per  cent; 
with  exclusion  of  pancreatic  juice  and  partial  exclusion  of  bile  80  to  90 
percent;  in  icterus  80  per  cent;  and  in  disease  of  IIk-  pHucreas  60 
per  cent. 

Proteins. — The  chyme,  more  or  less  strongly  acid  in  reaction,  and 
rich  in  albumoses,  acid  albuminates,  and  pepsin -peptones,  the  prod- 
ucts of  peptic  digestion,  is  greatly  modified  shortly  after  its  passage 
into  the  duodenum,  where  an  entirely  different  series  of  processes  is 
begtUK  The  albumins  and  albumoses  of  the  gastric  contents  are  pre- 
cipitated by  the  bile  in  acid,  not  in  alknliue  reaction:  that  is,  by  the 
free  biliary  acids,  and  notably  by  taurocholic  acid,  bnt  not  by  the 
liiliary  salts.  Peptones  are  not  so  precipitated.  Bnt  the  protein 
precipitntc  formed  by  the  bile  is  redissolved  by  an  excess.  It  is 
doubtful  whether  this  precipitation  occurs  to  any  considerable  extent 
in  the  hnnmn  subject,  in  whom  the  alkalinity  of  the  bile  and  pancreatic 
secretiot),  discliarged  into  the  intestine  V»y  a  eouniion  opening,  soon 
overcomes  the  acidity  of  the  chyme. 

When  the  reaction  in  tlie  duodenum  changes  from  acid  to  alkaline 
peptic  digestion  ceas<»s,  and  the  more  energetic  tryptic  digestion  begins. 
This,  supplemented  by  the  action  of  erepsin,  results  in  the  breaking 
down  of  the  albumins,  acid  albuminates,  albnnmses  and  pepsin -pep- 
tones to  trypsin -peptones,  and  finally  to  products  no  longer  responding 
to  the  lii!irct  reaction.  Tliese  changes  occur  principally  in  the  sin  all 
intestine,  ami  are  not  interfered  with  f>y  the  acids  prodnced  by  fer- 
nientatioii  of  the  carbohydrates,  notwithstanding  the  acid  reaction 
which  they  produce  in  the  lower  small  intestine.  It  is  also  in  tho 
small  iutestiue  that  the  greatest  absoriitiou  of  the  prodncts  of  digestion 
of  the  proteins  takes  place  throngh  the  intestinal  nnicosa  into  the  bhiod. 
Obviously  tlie  utility  of  protein  food  is  to  furnish  material  for  the 
formation  of  the  cojistitucnts  of  similar  nature  of  the  fluids  and  tissues 
of  the  organisoK  We  have  seen  that  tlie  processes  of  digestion  bring 
about  a  radical  breaking  down  of  the  protein  molecule  into  products 
far  removed  from  it  in  complexity  of  structure.  In  precisely  what 
form,  what  stage  of  decomposition,  these  prodncts  are  absorbed,  and 
how  and  whei*e  they  synthetically  regenerate  other  protein  nioleenles. 


646  MANUAL    OP    CHEMISTRY 

are  important  questions  for  future  investigation.  It  is  known  that 
native  or  denatured  albumins  may  be  absorbed  from  the  intestine  in 
small  amount,  and  albumoses  have  also  been  detected  in  minute  quan- 
tity in  the  blood,  but  these  observations  entirely  fail  to  afford  quanti- 
tatively an  explanation  of  the  mechanism  of  the  absorption  of  the 
products  of  protein  digestion,  or  of  the  reconstruction  of  the  protein 
molecule.  On  the  other  hand,  it  has  been  demonstrated  that  dogs 
can  be  maintained  in  perfect  nutrition,  and  in  nitrogenous  equilibrium 
when  fed  upon  the  products  of  tryptic  digestion,  carried  to  disappear- 
ance of  the  biuret  reaction. 

As  the  entire  quantity  of  protein  taken  with  the  food  is  not  simul- 
taneously attacked  by  the  digestive  agents,  they  and  their  products 
may  be  found  in  all  the  stages  of  digestion  at  different  points  through- 
out the  small  intestine,  and  unaltered  native  albumins  along  with 
their  products,  not  only  pass  the  ileo-coecal  valve,  but  may  be  dis- 
charged, as  waste,  in  the  faeces. 

In  the  large  intestine,  whose  peristalsis  is  comparatively  sluggish, 
and  the  reaction  of  whose  contents  is  usually  alkaline,  bacterial  action, 
different  in  kind  from  that  which  occurs  in  the  small  intestine,  takes 
place.  While  the  small  intestine  is  the  seat  of  fermentation  of  the 
carbohydrates,  putrefaction  of  the  proteins  occurs  almost  exclusively 
in  the  large  intestine.  This  is  most  intense  in  the  upper  part  of  the 
gut,  and  diminishes  downwards,  as  water  is  absorbed  from  the  intes- 
tinal contents,  which  assume  an  Increasing  firmness  of  consistency. 
The  products  of  intestinal  putrefaction  are  the  same  as  those  formed 
in  the  same  manner  outside  of  the  body,  those  of  anaerobic  putrefac- 
tion predominating.  These  products  include  albumoses  and  peptones, 
amido  acids  of  the  glycocoU  and  aspartic  series,  tyrosin,  tryptophane, 
volatile  fatty  acids,  mercaptan,  hydrogen  sulfld,  carbon  dioxid,  am- 
monia, methane,  hydrogen,  and  certain  products  of  decomposition  of 
tryptophane  and  tyrosin  which  are  charactertistic  of  anaerobic  putre- 
faction, and  which  exert  more  or  less  pronounced  toxic  actions.  These 
are  indole  (p.  539),  skatole,  and  skatole-a-carboxylic  acid,  products 
of  decomposition  of  tryptophane;  and  phenol,  paracresol  and  inter- 
mediate products  from  decomposition  of  tyrosin.  These  anaerobic 
products  are  in  part  discharjjed  in  the  ffpces,  to  which  they  communi- 
cate their  stercoraceous  odor  In  part  they  are  reabsorbed  and,  after  ' 
oxidation,  appear  in  the  urine  in  con jiiorate  combination,  either  as  ester  - 
sulfates  or  as  conjugate  fjlucuronates  (p.  732).  Indole  and  skatole— 
are    oxidized,     after    absorption,     to    phenolic    derivatives;     indole, 

^'6ll4\NH/CH,  to    iudoxyl,  or   /?-oxyindole,  C6H4<^^/if^^^CH,  aiuf 

skatole,   or    ^-methyl indole,   to    skatoxyl,    or  a-oxy-y3-niethylindole, 

^6H4<^NH^'^/^C)H,    which    then    combine    with    sulfates   or  with 


CHEMICAL  CHANGES   OCCURRING  IN  THE  INTESTINE         647 

glacarouates.  Skatole-a-carboxylic  acid,  C6H4\jjg  ' /C.COOH,  is 
formed  by  combination  of  skatole  and  carbon  dioxid.  In  the  forma- 
tion of  p-cresol  and  of  phenol,  tyrosin,  or  p-oxyphenyl-a-amidopro- 
pionic  acid,  (OH).C6H4.CH2.CHNH2.COOH,  is  first  deamidated  to 
p-oxyphenylpropionic  acid,  (OH).C6H4.CH2.CH2.COOH;  this  is  oxi- 
dized to  p-oxyphenylacetic  acid,  (OH)  .C6H4.CH2.COOH,  which,  by  loss 
of  carbon  dioxid,  forms  p-cresol,  HO.C6H4.CH3.  The  cresol  by  oxida- 
tion yields  phenol,  which  by  further  oxidation  forms  the  o-  and 
p-diphenols,  hydroquinone  and  pyrocatechin,  all  of  which  occur  as 
snlfocon jugate  compounds  in  the  urine.  The  amount  of  the  indole 
derivatives  eliminated  in  the  urine  affords  an  index  of  the  extent  of 
reabsorption  of  the  products  of  intestinal  bacterial  action  occurring  at 
the  time.  Certain  constituents  of  the  digestive  secretions  are  them- 
selves modified  by  bacterial  action.  Thus  the  biliary  pigments  are 
reduced  to  stercobilin  or  urobilin,  and  the  biliary  acids  are  split  into 
their  components,  which  suffer  further  change. 

Intestinal  Gases. — The  gases  of  the  intestine  consist  largely  of 
nitrogen,  derived  from  swallowed  air.  Oxygen  exists  only  in  very 
small  amount,  having  been  absorbed  either  by  the  host  or  by  the  bac- 
teria. Carbon  dioxid  is  constantly  present  in  notable  amount,  pro- 
duced by  putrefaction  of  the  proteins,  by  fermentative  decomposition 
of  the  carbohydrates,  and  by  neutralization  of  the  carbonates  of  the 
bile  and  pancreatic  secretion.  Hydrogen  is  formed  by  bacterial 
growth.  Minute  quantities  of  hydrogen  sulfid  resulting  from  decompo- 
sition of  the  proteins,  and  of  methane,  from  decomposition  of  both 
proteins  and  carbohydrates,  are  also  present. 

Faeces. — The  faaees  oonfniu  (1)  indigestible  material  contained  in 
the  food:  cellulose,  gums,  resins,  chlorophyll,  keratin,  haematin;  (2) 
excess  of  digestible  material  not  utilized:  starches,  fats,  shreds  of 
muscular  tissue,  coagulated  casein,  etc.;  (3)  unabsorbed  products  of 
partial  digestion:  albumoses,  peptones,  fatty  acids,  amido  acids,  etc.; 
(4)  morphological  elements  from  the  glands  and  intestinal  mucosa, 
more  or  less  altered;  (5)  organic  substances  derived  from  the  secre- 
tions discharged  into  the  intestine:  mucins,  nucleoproteids,  fats, 
cholesterol,  cholic  acid,  dyslysin,  stercobilin;  (6)  products  of  bac- 
terial action:  acids  of  the  acetic,  oxalic  and  lactic  series,  amido  acids 
of  the  glycocoll  and  aspartic  series,  tyrosin,  phenols,  indole,  skatole 
and  their  derivatives;  (7)  catabolio  products:  urea,  uric  acid,  xanthin 
bases;  (8)  mineral  substances  derived  from  the  food  or  from  the 
secretions:  water,  earthy  phosphates  and  sulfates,  ammonio-mag- 
nesian  phosphate,  silicic  acid,  silif*ates,  and  the  usual  soluble  salts; 
(9)  bacteria  and  their  detritus.  Exceptionally  also  entozoa  and  their 
ova.  gall-stones,  intestinal  concretions,  or  insoluble  residues  of  me- 
dicinal substances  may  be  present. 


648  MANUAL    OF    CHEMISTRY 

The  amount  of  the  faeces  depends  principally  upon  the  amount  of 
indigestible  material  taken  with  the  food.  It  is  therefore  greater  with 
the  herbivora,  whose  food  contains  a  large  proportion  of  cellulose, 
only  a  small  fraction  of  which  is  utilized,  than  in  the  carnivora.  lu 
man  it  is  usually  from  100  to  200  grams  per  diem,  but  may  be  500 
gms.  with  a  vegetable  diet,  and  may  be  reduced  to  less  than  one-quar- 
ter of  the  normal  amount  with  a  diet  from  which  cellulose  and  other 
useless  material  is  excluded.  Normally,  nearly  one -third  of  the  weight 
of  the  dried  fasces  consists  of  bacteria  and  their  detritus.  The  con- 
sistence of  the  faeces  depends  upon  the  amount  of  water  present.  The 
reaction  of  the  faeces  of  adults  is  usually  faintly  alkaline,  the  acidity 
of  the  acids  produced  by  bacterial  action  having  been  more  than  neu- 
tralized by  the  ammonia  and  amins  formed  by  ammoniacal  fermenta- 
tions. Sometimes,  however,  with  a  diet  rich  in  carbohydrates,  normal 
faeces  may  be  neutral  or  even  acid  in  reaction.  In  nursing  infants,  in 
whom  a  considerable  quantity  of  lactic  acid  is  formed  from  the  milk- 
sugar,  the  reaction  is  acid.  The  normal  color  of  the  faeces  is  due  to 
stercobilin  (hydrobilirubin),  derived  from  the  bile -pigments.  When 
the  bile  is  deficient,  the  faeces  ai-e  pale  in  color,  and  contain  a  large 
quantity  of  fat.  Pale-colored,  or  acholic,  stools  may,  however,  be 
passed,  in  which  the  amount  of  fat  is  not  excessive,  when  there  is  no 
hepatic  disturbance,  and,  probably,  the  bile-pigments  are  converted 
into  leuco,  or  colorless,  derivatives.  The  faeces  are  sometimes  alnaost 
black  in  color,  either  from  the  presence  of  haematm  or  haematoidin 
after  hemorrhages,  or  from  the  presence  of  dark -colored  metallic  sul- 
fids  after  administration  of  the  salts  of  iron,  bismuth  or  lead.  When 
tliese  sulfids  are  present  they  frequently  deposit  as  heavy,  dark -colored 
powders  at  the  bottom  of  the  vessel.  The  faecal  odor  is  largely  due  to 
indole  and  skatole,  somewhat  modified  by  the  odors  of  ammonia,  of 
hydrogen  sulfia  and  of  mercaptans. 

C'ueniieal  analysis  of  faeces  is  rarely  resorted  to  for  clinical  infor- 
mation, except  when  the  amount  of  fat  is  of  interest  in  connection 
with  hepatic  or  pancreatic  disease,  but  in  investigations  of  metabolism 
the  results  of  quantitative  determinations  of  various  constituents  of 
the  faeces  are  data  essential  to  the  inquiry.  The  nature  of  the  con- 
stituents to  be  determined  varies  with  the  character  of  the  problem 
under  examination,  but  those  most  frequently  of  interest  are  nitrogen 
and  fats.  Both  are  determined  from  the  dried  faeces,  the  former  by 
the  Kjeldahl  method,  the  latter  by  extraction  with  ether,  and,  if 
necessary,  determination  of  true  fat  in  the  mixture  of  fat,  lecithins 
and  cholesterol  which  constitutes  the  "crude  fat"  of  the  ether  extract, 
by  methods  described  in  works  devoted  to  analytical  methods. 

Meconium — the  contents  of  the    lower  intestine  of   the  foetus 
at  birth — is  dark  brown  or  green  in  color,  almost  odorless,  acid  in 


THE    BLOOD 


G41> 


' 


imf*t!o:^  and  ?emi* solid  in  eonsist*MR*y.  It  contains  epithelial  cells, 
ftvqiiently  stained  gi*een,  fat  globnles,  crystals  of  cholesterol  and  of 
bilirubiti.  In  chemical  composition  it  consists  of  abont  80%  water 
nnd  20%  solids.  The  solids  consist  of  mucin,  biliary  acids  and  pi^:- 
mcrits,  cholesterol,  fat,  soaps,  peptones,  lencin,  tyrosin  and  salts, 
notably  calcium  and  magnesinm  phosphates.  Stains  prodnced  by 
ineeoniurn  msiy  be  disting:utshed  from  ftecal  stains  by  the  fact  that 
the  former  give  Omelin-s  and  Pettenkofer*s  rcaetions,  while  the 
latter  do  not. 

Intestinal  Concretions. — ^  Besides  gall-stones,  the  intestine  may 
contain  true  intestinal  concretions,  which  are,  however,  of  nnich 
rarer  occurrence  in  the  human  subject  than  in  the  lower  animals. 
They  usually  consist  of  concentric  layers  of  calcium  carbonate  or 
of  tricalcic  phosphate »  with  a  little  fat  and  pigment,  deposited  upon 
&ome  insoluble  foreign  substance  as  a  nucleus,  or  they  nniy  be  formed 
in  the  vermiform  appendix  without  a  nucleus.  The  intestines  of 
horses  and  cattle  frequently  contain  large  calcic  calculi,  sometimes 
weighing  several  pounds  (16  lbs.  in  a  horse);  or  ^* hair-halls/'  con- 
sisting of  masses  of  hair  agglutinated  into  hard  balls.  Bezoar  stones 
are  concretions  from  the  intestines  of  certain  goats  and  antelopes, 
which  contain  either  lithofellic  acid,  a  peculiar  acid  related  to  cholic 
acid,  or  ellagic  acid,  a  derivative  of  gallic  acid,  and  biliary  pigments. 
Ambergris  is  an  intestinal  concretion  of  the  whale,  coutaining  a 
non*nitrogenized  substance,  am  brain,  related  to  cholesterol. 

THE    BLOOD, 

The  blood  being  the  circulating  medium  by  which  oxygen  and 
the  products  of  digestion  are  carried  to  the  tissues,  and  by  which 
the  waste  products  of  tissue  metabolism  are  carried  to  the  excretory 
organs,  varies  notably  in  composition  in  diflPerent  parts  of  the  cir- 
culation at  different  times  and  under  vnryiufj  conditions  of  health 
or  disease. 

The  living,  circnlatinj;  blood  I'onsists  of  two  parts,  the  plasma, 
the  liquid  portion,  and  the  corpuscular  elements  suspended  therein. 
It  is  desirable  to  consider  the  chemistry  of  these  two  constituents 
of  the  blood  first,  and  sobseqtieutly  that  of  the  blood  as  a  whole. 

The  blood,  very  soon  after  being  removed  from  the  living  animal, 
undergoes  the  chemical  and  physical  change  of  coagulation,  involving 
modification  of  the  proteins  of  the  plasma,  and  the  separation  of  the 
blood  into  the  two  new  divisions  of  clot,  consisting  of  the  newly- 
formed  fibrin  and  the  corpuscles;  and  the  serum,  containing  those 
constituents  of  the  plasma  not  concerned  in  the  formation  of  fibrin. 
In  order,  therefore,  to  obtain  the  plasma  and  corpuscles  free  from 


650  MANUAL    OF    CHEMISTRY 

each  other  some  method  must  be  adopted  to  prevent  the  occurrence 
of  coagulation  during  the  separation.  Several  methods  have  been 
used  for  this  purpose  : 

(1)  By  taking  advantage  of  the  fact  that  the  blood  of  the  horse 
coagulates  very  slowly  at  low  temperatures.  Horse's  blood  is  col- 
lected in  a  tall,  narrow  glass  vessel,  surrounded  by  a  freezing  mixture 
of  ice  and  salt,  which  is  then  maintained  at  0°  until  the  corpuscles 
have  settled.     Coagulation  does  not  take  place  for  several  days. 

(2)  On  a  small  scale  the  corpuscles  may  be  separated  from  the 
plasma  by  increasing  the  rapidity  of  their  deposition  by  the  use  of 
the  haematocrit.  This  is  simply  a  centrifuge  revolving  with  great 
rapidity  (3,000  to  5,000  revolutions  a  minute).  With  the  very  nar- 
row tubes  used,  the  separation  is  complete  in  about  two  minutes,  and 
before  coagulation  has  interfered. 

(3)  The  centrifuge,  revolved  at  a  lower  speed,  may  be  also  used 
with  larger  quantities  of  blood,  but  then  some  agency  must  be  used 
to  delay  coagulation.  One  method  consists  in  injecting  a  solution 
of  albumose  into  the  circulation  of  a  dog,  collecting  the  blood  and 
centrifugating  it.  The  plasma  so  obtained  is  known  as  peptone- 
plasma.  Or  an  infusion  of  the  mouth  of  the  leech  may  be  similarly 
used. 

(4)  If  the  blood,  as  it  flows  from  the  vessel  be  mixed  with  either 
an  equal  volume  of  saturated  solution  of  sodium  sulfate,  or  with  the 
same  quantity  of  a  10%  sodium  chlorid  solution,  or  with  one-third  its 
volume  of  a  saturated  solution  of  magnesium  sulfate,  and  the  mix- 
ture maintained  at  a  low  temperature,  coagulation  will  be  delayed 
sufficiently  to  permit  the  corpuscles  to  settle.  This  plasma  is  called 
salt  plasma. 

(5)  The  best  method  depends  upon  the  removal  of  the  calcium 
salts,  whose  presence  is  necessary  to  coagulation,  by  precipitation  as 
calcium  oxalate.  The  blood  is  received  in  a  dilute  solution  of  po- 
tassium oxalate  in  such  proportion  that  the  mixture  contains  0.l7r  of 
oxalic  acid,  and  the  mixture  set  aside  until  the  corpuscles  deposit. 
The  plasma,  known  as  oxalate  plasma,  regains  its  power  of  coagula- 
tion on  restoration  of  the  calcium  salts. 


PLASMA    AND    SERUM. 

The  plasma,  at  the  temperature  of  0°,  above  which  it  rapidly 
coagulates  into  clot  and  serum,  is  a  viscid  liquid,  yellowish,  or 
greenish -yellow  in  color,  strongly  alkaline  in  reaction. 

Composition. — But  few  complete  analyses  of  blood -plasma  have 
been  made.  Indeed,  cousidering  the  variations  in  its  quantitative 
composition,  above  referred  to,  the  results  of  such  analyses  can  only 


10.1 

6.5 

67.5 

.   .    38.4 
.   .    24.6 

1.2^ 

4.0 
6.4 

►  .    .    12.9 

1.7, 

PLASMA    AND    SERUM  651 

be  considered  as  applying  to  the  particular  sample  analyzed,  and  not 
as  representing  the  mean  composition  of  the  plasma  except  in  a 
general  way.  The  following  are  results  obtained  from  horse's  blood, 
the  first  an  analysis  by  Hoppe-Seyler,  the  latter  the  mean  of  three 
analyses  by  Hammarsten  : 

I.  II. 

Water 908.4  .    .    .  917.6 

Solids 91.6  .   .    .    82.4 

Protein  bodies 77.6  .   .    .    69.5 

Fibrinogen 

Serum  globulin 

Serum  albumin 

Fat      

Extractives 

Soluble  salts 

Insoluble  salts 

Fibrinogen,  the  parent  substance  of  fibrin,  exists  in  the  plasma, 
chyle,  lymph,  and  in  transudates  and  exudates.  It  has  the  charac- 
teristic property  of  coagulating  in  presence  of  calcium  salts  and  an 
enzyme  (thrombin),  with  formation  of  fibrin.  When  moist,  it  forms 
viscid,  elastic  masses  or  flocks,  which  readily  fuse  together.  It  has 
the  general  properties  of  the  globulins,  from  which  it  differs  in  that 
the  addition  of  calcium  chlorid  solution  to  its  very  faintly  alkaline 
and  salt-free  solution  causes  a  precipitate  which  contains  calcium, 
and  soon  becomes  insoluble.  This  precipitate  is  not  formed  in  pres- 
ence of  sodium  chlorid,  nor  with  an  excess  of  calcium  chlorid. 
Fibrinogen  is  insoluble  in  pure  water,  soluble  in  dilute  sodium  chlorid 
solution,  and  this  solution,  neutral,  or  very  faintly  alkaline,  coagulates 
at  56°,  apparently  suffering  decomposition  into  two  globulins,  the 
second  of  which  coagulates  at  65° .  From  its  salt  solution  it  is  precip- 
itated by  dialysis.  Its  solutions  are  precipitated  by  addition  of  an 
equal  volume  of  saturated  sodium  chlorid  solution,  and,  completely, 
by  excess  of  the  solid  salt;  in  which  latter  respect  it  differs  from 
serum -globulin.  It  is  also  precipitated  by  passing  a  stream  of  CO2 
through  its  solution.  It  decomposes  hydrogen  peroxid  energetically.  Its 
solutions  are  leevogyrous,  [a]i>= — 52.2°,  It  is  obtained  from  salt- 
or  oxalate -plasma  by  precipitation  with  an  equal  volume  of  saturated 
salt  solution  and  purification. 

Fibrin  is  the  substance  formed  in  the  so-called  spontaneous 
coagulation  of  blood,  lymph,  and  transudates,  or  by  the  addition  of 
.serum,  or  of  thrombin,  to  a  solution  of  fibrinogen.  The  typical 
fibrin,  as  obtained  by  whipping  blood  with  a  bundle  of  twigs  or 
broom,  and  washing  until  white,  is  in  elastic  fibers,  insoluble  in 
water,  alcohol,  or  ether.     In  dilute  salt  solution,  putrefaction  being 


G52  MANUAL    OP    CHEMISTRY 

prevented,  it  dissolves  very  slowly  at  the  ordinary  temperature,  some- 
what more  rapidly  at  40"".  In  solution  of  HCl,  KHO,  or  NaHO  of 
1  p/m  it  swells,  gelatinizes,  and  slowly  dissolves  after  some  days.  It 
decomposes  hydrogen  peroxid  energetically,  but  not  after  having  been 
heated,  or  in  contact  with  alcohol. 

A  solution  of  pure  fibrinogen  does  not  coagulate  at  the  ordinary 
temperature,  but  it  does  so  very  soon  after  addition  of  a  little  blood- 
serum,  or  of  a  fragment  of  fibrin  washed  with  water  only.  These 
therefore  contain  a  substance,  an  enzyme,  called  thrombin,  or  fibrin- 
ferment,  which  sets  up  the  conversion  of  fibrinogen  into  fibrin.  This 
substance  is  by  some  believed  to  be  a  globulin,  by  others  a  nucleo- 
proteid.  It  is  active  in  very  small  amount,  most  active  at  about  40^ 
and  in  presence  of  calcium  salts.  It  does  not  act  in  the  absence  of 
neutral  salts,  and  its  power  is  completely  destroyed  by  a  temperature 
of  70°.  In  the  formation  of  fibrin  the  fibrinogen  is  considered  to  be 
split  by  the  enzyme  into  fibrin  and  a  soluble* globulin,  called  fibrino- 
globulin,  which  remains  in  the  serum.  The  coagulation  of  blood  is, 
however,  a  more  complex  process  than  the  coagulation  of  fibrinogen 
alone,  and  in  it  the  corpuscles  play  a  part  (see  p.  667).  The  plasma 
does  not  contain  thrombin,  but  its  zjmogen,  prothrombin,  which  is 
converted  into  thrombin  by  the  soluble  calcium  salts.  Thrombin  in 
solution  when  injected  into  the  circulation  causes  death  from  throm- 
bosis almost  immediately. 

Serum-globulin  —  Paraglobulin  —  Fibrinoplastic  substance  — 
occurs  in  the  blood -plasma  and  serum,  and  in  the  red  and  white 
blood -corpuscles,  and  constitutes  more  than  half  of  the  total  proteins 
of  the  blood,  also  in  lymph,  in  transudates  and  exudates,  and  patho- 
logically in  the  urine.  It  is  not  a  simple  substance,  but  a  mixture  of 
two  or  more  globulins.  It  has  the  general  properties  of  the  globulins. 
When  moist  it  forms  white  flocks,  not  elastic  or  sticky.  It  differs 
from  fibrinogen  in  not  being  precipitated  by  an  equal  volume  of  sat- 
urated sodium  chlorid  solution,  and  only  incompletely  by  salting  with 
sodium  chlorid  to  saturation.  It  is  completely  precipitated  by  satura- 
tion with  magnesium  sulfate,  or  by  addition  of  an  equal  volume  of 
saturated  ammonium  sulfate  solution.  Its  coagulation  temperature  in 
solutions  containing  5  to  10  per  cent  of  sodium  chlorid  is  75°.  Its 
solutions  are  hcvogyrous,  Md  =  — 47.8°.  Serum -globulin,  as  usually 
obtained  from  blood,  when  boiled  with  dilute  acids,  yields  a  reducing 
substance.  Euglobulin  and  pseudoglobulin  are  two  components  of 
the  mixture  called  serum  globulin.  The  precipitation  limits  of  the 
former  witli  ammonium  sulfate  are  2.8  and  3.4;  those  of  the  latter, 
3.6  and  4.4.  The  former  is  precipitated  by  dialysis  of  its  salt  solu- 
tions, and  is  therefore  insoluble  in  water;  the  latter  is  not  so  precip- 
itated.    But  apparently  these  substances  are  themselves  mixtures, 


PLASMA    AND    SERUM 


6-i3 


each  being  separable  into  a  water-soluble  component  and  one  wlueli 
is  insoluble  in  water*  The  latter  are  called  para-euglobylio  and  para- 
pseudoglobulin. 

BernTn- globulin  is  obtained  from  blood -serum  by  slight  aeidulatioii 
with  acetic  aeid,  and  addition  of  from  10  to  20  volumes  of  water^  or  by 
passage  of  CO2  through  its  dilute  solution,  when  it  separates  as  a 
flocculeut  precipitate,  which  is  pnrified  by  solution  in  dilute  salt  koIu* 
tion,  and  repreeipitatiou  by  water.  As  so  obtained  it  is  not  free  from 
lecithins  and  thrombin.  It  can  be  obtained  free  from  the  latter  from 
the  fluid  of  hydrocele. 

Serum-albumin — occurs  in  blood -plasma  and  serum,  in  lymph, 
in  transudates  and  exudates,  probably  in  many  tissues,  and,  patlio- 
logieally,  iti  the  urine.  When  nn^ist  it  is  a  white,  floeeulcnt  material  j 
when  dry,  translucent,  gummy,  brittle,  and  hygroscopic.  It  has  the 
general  properties  of  the  allnimins.  It  is  not  a  simple  substance,  but 
a  mixture  of  three  serines,  of  which  one  is  amorphous  and  two 
crystalline,  one  crystallizing  in  hexagonal  prisms,  the  other  in  long 
needles.  The  mixed  serum -albumin  has  a  coagulation  temperature 
varying  frtun  lO'^  to  85^,  depending  upon  the  qiTJintjty  of  XaCl 
present,  and  the  reaction.  It  is  hevogyrfujs,  [f/jo^^  — ^02.6°  to  64. 6"^. 
It  has  not  been  obtained  entirely  free  from  salt^s.  From  solutions 
containing  the  raininium  amount  of  salts  it  is  not  coagulated  by  heat 
or  by  alcohol,  but  is  after  addition  of  NaCL  Serum -albumin  is  dis- 
tinctly basic,  being  capable  of  removing  sulfuric  acid  from  sulfates 
and  forming  a  compound  from  which  the  acid  cannot  be  washed  out 
by  water. 

Blood- serum. — When  blood  is  drawn  from  the  blood-vessels  it 
soon  coagulates  into  a  jelly-like  mass,  occupying  the  volume  of  the 
original  lifjuid.  This  mass  soon  contracts  and  expels  a  liquid,  which 
is  the  serum,  and  which  differs  from  the  plasma  in  that  it  contains 
thrombin,  fibrinoglobulin,  derived  from  fibrinogen,  and  cell*gIobulin, 
a  protein  derived  from  the  leucocytes  during  coagulation,  and  has  lost 
fibrinogen,  fibrin  and  some  portion  of  its  salts,  particularly  of  those 
of  calcium.  In  other  respects  the  two  are  qualitatively  alike.  It  is  a 
sticky  liquid,  more  strongly  alkaline  than  the  plasma,  sp.  gr.  1027  to 
1032^  pale  yellow,  with  a  greenish  tinge^  usually  clear,  but  opalescent 
or  milky  during  digestion  of  fats. 

The  constituents  of  the  plasma  and  of  the  serum,  other  than 
the  proteins,  i>eing  identical,  are  most  readily  studied  in  the  serum, 
which  is  more  easily  obtainable  than  the  plasma.  They  include  the 
fats,  carbohydrates,  extractives  and  mineral  salts.  The  term  'Vx* 
tractives,*'  in  an  analytical  statement,  is  the  equivalent  of  ^'miscel- 
laneous*' in  a  classification,  and  the  substances  arranged  under  this 
head  are  of  diverse  nature,  present  in  small  quantity,  and,  while  they 


654  MANUAL    OP    CHEMISTRY 

are  not  separately  determined  in  the  pavtienlar  analysis  referred  to, 
some  of  them  are  of  great  physiological  interest. 

Fats — exist  in  the  plasma  or  serum,  suspended  in  minute  oil 
globules,  as  a  fine  emulsion.  They  are  present  during  fasting  in 
the  proportion  of  1  to  7  p/m,  and  are  greatly  increased  in  amount 
during  digestion  of  fats.  Soaps,  derived  from  the  fats,  are  also 
present.  Besides  the  true  fats  (p.  366),  the  plasma  contains  lecithins 
(p.  367),  cholesterol  and  cholesterol  esters  (p.  638). 

Carbohydrates. —  The  carbohjdrates  of  the  blood  appear  to  exist 
almost  exclusively  in  the  plasma,  none  having  been  found  in  the 
corpuscles,  except  glycogen  in  the  leucocytes.  They  consist  of  glu- 
cose, glycogen,  and  a  carbohydrate  in  some  form  of  nitrogen ized 
or  phosphorized  combination.  Glucose  is  a  constant  constituent  of 
the  plasma,  even  during  starvation,  and  is  present  in  about  the  pro- 
portion of  0.5  to  1  p/m,  without  any  notable  variation  in  different 
parts  of  the  circulation  under  normal  conditions,  except  that  it  is 
greatly  increased  in  amount  in  the  portal  blood  during  digestion  of 
carbohydrates.  When  the  proportion  of  sugar  in  the  blood  exceeds  3 
p/m  (hyperglykaemia),  either  from  excessive  absorption  or  in  natural 
or  experimental  diabetes,  it  is  eliminated  by  the  urine  (glycosuria). 
The  amount  of  reducing  substance,  calculated  as  glucose,  in  the  blood 
is  increased  after  hemorrhages,  and  in  diabetes,  in  which  latter 
condition  it  may  reach  9  p/m.  Glycogen,  although  more  usually 
a  constituent  of  tissue  elements  than  of  the  liquids  of  the  body, 
is  present  in  the  plasma  in  very  variable  amount,  usually  in 
mere  traces.  The  plasma  contains  small  quantities  of  a  substaiiee 
other  than  glycogen,  and  containing  nitrogen  and  phosphorus,  which 
does  not  itself  reduce  Fehling's  solution,  but  which  on  hydrolysis  by 
dilute  acids  yields  a  reducing  substance.  The  nature  of  this  substance, 
which  also  occurs  in  the  liver,  and  has  been  called  jecorin,  is  undeter- 
mined, although  it  is  certain  that  it  is  not  a  chemical  individual,  as  on 
fractional  precipitation  it  gives  products  in  which  the  phosphorus 
varies  from  3.16  to  0.38  per  cent,  and  the  nitrogen  from  4.55  to  1.45. 
The  so-called  animal  gum,  obtained  from  the  serum,  also  yields  a 
reducins:  substance  by  the  action  of  dilute  acids,  does  not  ferment,  is 
optically  inactive,  and  is  said  to  have  the  empirical  formula  (CeHioOs)*!. 
Still  another  reducing  substance,  which  is  difficultly  fermentable,  is 
soluble  in  ether,  and  probably  consists  of  conjugate  glucuronates, 
exists  in  small  quantity  in  the  plasma. 

Enzymes. — The  plasma  contains  several  enzymes  or  zymogens, 
whi(*h  are  probably  produced  in  whole  or  in  part  by  the  corpuscular 
elements:  (1)  Prothrombin,  the  zymogen  of  thrombin,  the  fibrin 
forming  enzyme  (p.  668);  (2)  a  diastatic  enzyme,  or  amylase. 
Blood  serum  or  lymph,  added  to  starch  paste  or  glycogen  solution, 


PLASMA    AND    SEBUM 


6SS 


[ 


brings  about  the  formation  of  timltose  and  ifeonialtose^  if  tlie  mixture 
be  kept  at  about  40°;  (3)  an  invertin,  a  maltase,  wliich  l>nug8  about 
the  hydrolysis  of  tlie  product  of  the  di astatic  action,  witli  forniatiun 
of  gbicose,  if  the  action  above  mentioned  be  allowed  to  continue;  (4) 
a  glucase  (an  oxidase,  not  an  iuvertin).  Tlje  proportion  of  ghicose 
in  blood  serum  gradually  diminishes  on  standing,  even  in  the  absence 
of  organized  feruicnts.  This  glucolysis  is  due  to  the,  action  of  an 
enzyme  whose  activity  is  destroyed  by  a  temperature  of  54°,  and 
which  apparently  originates  in  the  leucocytes;  (5)  a  lipase,  which 
saponifies  neutral  fats.  Besides  the  above  the  blood  contains  sub- 
stances, possibly  enzyiues,  which  l>ring  about  the  conversion  of  the 
emulsified  fats  into  some  unknown  form  of  soluble  condiination,  and 
which  arrest  the  action  of  the  digestive  enzymes  absorbed  from  the 
intestine. 

Extractives. — The  most  abundant  are  urea,  creatin,  and  salts  of 
uric,  carbamic,  phosphocarnic,  paralactic  and  hippuric  acids,  etc.; 
also,  pathologically,  xsnthin  bases,  leuein,  tyrosin,  acetone,  and 
biliary  salts  and  pifjments.  Urea  is  present  in  human  blood  in  the 
proportion  of  0.14  to  0.4  p/m;  more  abundant  in  the  blocul  of  the 
gplente,  portal  and  hepatic  veins  than  in  that  of  the  carotid  artery; 
more  abundant  in  placental  blood,  0.28  to  0.62  p/m.  In  aoituals  the 
proportion  rapidly  increases  after  nephrectomy,  reaching  2,06  to  2.76 
p/m  in  27  hours.  In  human  blood  the  amount  is  greatly  increased  in 
cholera,  2.4  to  3.6  p/m,  and»  particularly,  in  nephritis,  15.0  p/m. 

The  yelloxv  coloring  matter  of  the  plosma  and  serum  appears  to 
belong  to  the  class  of  luteins,  or  lipochroms,  which  exist  iu  fats, 
corpora  lutea^  egg*yolks,  etc.  A  coloring- matter  has  been  obtained 
fixmi  the  serum  of  ox  blood,  which,  in  amylic  alcohol  solution, 
gives  a  spectrum  of  two  bauds,  one  covering  F,  the  other  between 
P  and  Q, 

Mineral  Salts. — The  serum  contains  a  somewhat  smaller  qnantity 
of  mineral  material  than  the  plasma,  a  part  of  the  calcium  salts 
having  passed  iuto  the  clot.  The  total  ash  of  the  serum  equals  8.3 
to  9.2  p/m.  In  composition  it  does  not  vary  greatly  in  different 
animals.  In  1000  parts  of  human  blood  serum  there  are:  KsO-O.rSST 
to  0.401,  Na2O-l/J90,  CaO-0J55.  MgO-0.101,  01-3.565  to  3.659, 
besides  phosphoric  acid,  and  traces  of  silicon,  fiuorin,  iron,  man- 
ganese, copper  aud  ammoniacal  compounds.  The  most  abundant 
constituent  of  the  ash  is  sodium  chlorid,  60  to  70  per  cent,  of  the 
ash.  The  calcium  and  magnesium  arc  probably  present  as  phos- 
phates, and  the  former  also  as  chloride  the  sodium  and  potassium  as 
chlorids,  phosphates  and  carbonates  or  bicarbonates.  The  amount  of 
base  present  is  in  excess  of  the  amonnt  of  acid,  therefore  a  part  of 
the  bases  must  be  present  as  carbonates  or  in  organic  combination. 


65G 


MANUAL    OF    CHEMISTBT 


The  presence  of  earbouates  ia  demonstrated.  The  organic  acids  above 
mentioned  are  contained  in  the  plasma  in  saline  combination;  and 
the  existence  of  mineral  elements  in  protein  combination  is  shown 
by  the  fact  that  the  mineral  eonstitnents  are  not  completely 
removable  by  dialysis* 


BLOOD    CORPUSCLES. 


tteiy       J 

4 


of  the  blood  are  of  three  kinds:    the 
corpuscles,    or    leucocytes,  and    the 


The  corpuscular  elements 
red    corposcles,   tlie   white 
plaques,  or  platelets. 

The  red  corpuscles  are  separated  from  the  plasma  by  the  methods 
given  above.  As  tliey  are  heavier,  they  sink  more  rapidly  than  the 
other  eorpuseolar  elements,  and  are  consequently  found  in  the  lower 
part  of  the  deposit.  When  they  ai^  required  in  larger  quantities,  the 
blood  is  defibrinated  by  whipping,  diluted  with  ten  volumes  of  1  per 
cent  NaCl  solution,  filtered  tlirougli  muslin ,  and  centrifuged.  The 
corpuscles  are  repeatedly  washed  with  salt  solution  in  the  centrifuge, 
and  freed  from  fats,  lecitliiii*?  and  eholesterol  by  washing  with  warm 
alcohol  ether  on  a  paper  filter. 

The  number  of  red  corpuscles  in  normal  blood  is  fairly  constant 
at  5,000,000  to  5,500,0<X>  in  a  cubic  millimeter  in  the  male,  and 
4,500,000  in  the  female,  Patholo^ieally,  the  count  may  rise  to 
6,500,000,  with  loss  of  large  quantities  of  water  from  the  system,  or 
fall  as  low  as  500,000  in  pernicious  anaemia*  Their  variations  in  size, 
shape  and  number  have  been  the  subject  of  much  careful  study,  Snf- 
flre  it  to  say  here  that  in  man  they  are  rounded  bi-coueave  discs, 
nou -nucleated,  having  an  avernj^^e  diameter  of  7  to  8  ft  (/*=micro- 
millimeter===0.001  mm.).  lu  other  nmmmals,  except  camels,  they 
have  the  same  shape  as  in  man,  but  differ  in  size,  while  in  camels, 
birds,  fishes  and  reptiles,  they  are  oval  and  nucleated. 

On  contact  with  w^ater  the  corpuscles  swell  atid  give  up  their  color- 
ing matter,  which  goes  into  solution,  leaving  the  stroma,  a  colorless 
mass,  which  may  be  made  to  retract  to  the  original  size  and  shape  of 
the  corpuscle  by  the  action  of  carbon  dioxid,  dilute  acids,  acid  salts* 
and  other  agents.  By  the  action  of  water  or  of  very  dilute  salt  solu- 
tions, or  by  alternate  freesfiing  and  thawing,  or  by  agitation  with 
chloroform  or  ether,  or  by  the  action  of  bile,  the  corpuscles  undergo 
cytolysis,  also  referred  to  as  haemolysis^  hsemocyto lysis,  or  ery- 
throlysiSt  i,  e.,  they  are  broken  down  and  their  coloring  matter  goes 
into  solution,  a  change  which  is  referred  to  when  thus  produced  out- 
side tln^  body  as  lakeing,  or  lake-coloring  (lakfarben),  from  the 
resemblance  of  the  product  to  the  pigments  called  'Hakes."  Cytolj-sis 
also  occurs  normally  in  the  body  to  a  certain  extent,  cells  which  have 


4 
4 


BLOOD    CORPUSCLES 


657 


Dtitgrown  their  usefulness  beiug  disintegrated,  and  the  liberated  eolor- 
iu^  matter  split  in  the  liver  tor  the  formation  of  bile  pigment  from 
t!ie  nun -ferruginous  part,  wliile  tbe  iron  is  in  M  prtAaihUiiy  utilized 
Jfor  the  produetion  of  new  blood  coloring  matter.  In  disease,  notably 
in  so-cailed  htt^njato-hepati^^euous  jauodiee  and  in  aeute  fet>rile  dis- 
^aseSf  by  the  action  of  the  cytotoxins,  or  cytolysins  existing  in  eer- 
tain  sera  (p.  671),  and  by  the  action  of  many  venoms  and  poisons, 
icucb  as  rattlesnake  and  eobra  venoms,  hydrogen  arsenid,  chlorates, 
abrin,  saponin,  etc.,  the  destruetiou  of  red  corpuscles  is  increased » 
Bometimes  enormously. 

If  portions  of  defibrinated  ox -bloody  or  of  the  corpuscles  there- 
from, be  agitated  with  sohiiions  of  NaCl  of  varying  degrees  of  con- 
centration, the  lowest  being,  say»  0,2  per  cent  and  the  highest  0.7  per 
-cent,  it  will  be  found  that  lakeing  will  occur,  and  the  solution  will 
become  colored  from  dissolved  htemoglobin,  in  all  solntious  having  a 
less  degree  of  eoneentration  than  0,585  per  cent,  but  not  in  the  others. 
If,  in  place  of  solutions  of  NaCl,  we  use  solutions  of  KNO3,  it  will  be 
found  that  the  lowest  concentratiou  in  wdiich  lakeing  will  not  occur 
is  1.01  per  cent.  That  lowest  degree  of  concentration  of  a  solution  of 
n  given  salt  in  which  lakeing  does  not  occur  is  called  the  isotonic 
coefficient  of  that  salt,  as  0.585  for  NaCl  and  1.01  for  KNOa^  and 
i^ohUions  of  that  degree  of  concentration  are  said  to  be  isotonic  with 
the  corpuscles,  while  solntious  of  greater  concentration  are  said  to  he 
hyperisotonic. 

Solutions  of  NaCl  and  of  KNO:t  of  0.585  and  1.01  per  cent  respec- 
tively are  N  10  stdntions  of  those  salts,  and  experimenls  with  solutions 
-of  other  salts  have  sliown  that  with  them  N/10  solutions  are  also 
isotonic.  8nch  solutions,  containing  equal  numbers  of  molecules,  are 
Isosmotic  with  each  other  (p.  67),  and  it  may  be  considered  as 
<lenioustrated  that  the  phenomenon  of  lakeing  is  due  to  difference  of 
osmotic  pressures  iu  the  corpuscles  and  in  tbe  surrounding  medium, 
although  the  purely  physical  act  of  diffusion  is  accompnnied  by  one  of 
•chemical  nature  involved  in  the  liberation  of  the  coloring  matter  from 
the  condition  of  combination  iu  which  it  exists  m  the  corpuscles 
(below).  The  plasma  is,  however,  hyperisotonic.  Its  osmotic  pres- 
mre,  as  determined  by  its  freezing  point  (pp.  67^-69),  is  equal  to 
;liat  of  a  solution  of  NaCl  of  0.9  per  cent  concentratiou,  and  the  dif- 
ference between  the  condition  of  equality  of  osmotic  pressures  and 
that  represented  by  the  isotonic  coefficient,  about  2.3  atm.,  may  be 
<*onsidered  as  representing  the  degree  of  pressure  rt^qnired  to  rnptnre 
the  corpuscles  and  cause  lakeing.  Usually  solutions  isosmotic  with 
0.58  per  cent  Na(^l  solution  are  also  isotonic,  but  certain  substances, 
^  Fuch  as  urea,  ammonium  salts,  glycerol,  sodium  carbonate,  and  the 
\  poisons  above  mentioned,  are  exceptions  to  the  rule,  and  lakeing 


658  MANUAL    OP    CHEMISTRY 

occurs  in  their  stronger  solutions.  Apparently  this  departure  from 
the  rule  depends  upon  an  action  upon  the  stroma,  as  it  is  not  observed 
with  saponin  after  the  stroma  has  been  hardened  by  formic  aldehyde, 
and  has  had  its  cholesterol  and  lecithins  removed  by  ether. 

The  freezing  point  of  normal  blood  is  fairly  constant  at  —0.56°. 
This  depression  from  0°=^=  — 0.56°,  represents  an  osmotic  pres- 
sure of  6.78  atm.  (p.  68).  This  pressure  is  the  sum  of  the  pressures 
of  all  of  the  molecules  and  ions,  mineral  and  organic,  present  in  the 
blood,  and,  as  that  fraction  due  to  fibrin  is  small,  the  osmotic  pres- 
sures of  the  whole  blood  and  of  the  plasma  and  serum  are  nearly  alike. 
With  dilution  of  the  blood,  as  by  absorption  of  large  quantities  of 
water,  the  value  of  A  may  normally  fall  to  — 0.51°=6.17  atm.,  and 
with  concentration,  as  by  absorption  of  notable  quantities  of  solids, 
particularly  of  highly  ionized  molecules  such  as  salts,  it  may  rise  to 
— 0.62°=7.5  atm.  Concentration  may  also  result  from  deficient  elim- 
ination of  solids  because  of  renal  disease,  when  the  value  of  A  may 
exceed  — 1°=12.1  atm.  The  determination  of  the  value  of  A  in  the 
blood,  particularly  when  taken  in  connection  with  the  same  value  for 
the  urine  from  each  kidney  separately,  is  therefore  of  service  in  the 
diagnosis  of  kidney  disease. 

The  electrical  conductivity  of  blood  serum  depends  upon  the  con- 
centration of  the  ions  present,  and  is  not  affected  by  unionized  mole- 
cules (pp.  41,  75).     It  is   therefore   influenced  by  the   quantity  of 
salts,  but  not  by  the  proteins,  urea,  or  other  non-conductors,  and  is 
an  index  of  that  fraction  of  the  blood -concentration,  shown  by  the 
osmotic  pressure,  which  is  due  to  salts.    The  value  of  «  for  a  column 
of  serum  1  sq.  cm.  in  cross  section  and  1  cm.  long  is  'c=0.012.    As 
each  salt  contributes  to  the  conductivity  in  proportion  to  its  concen- 
tration, a  large  fraction  of  f  is  due  to  NaCl.    Variations  in  the  quan- 
tity of  salts  in  the  plasma  or  serum  can  be  better  studied  by  variations 
in  the  value  of  «  than  by  analj'ses,  because  the  determinations  are 
more  delicate,  and  because  the  ash,  which  is  the  material  examined  in 
analyses,  contains  constituents  produced  by  combustion  of  organic 
substances,  which  are  not  present  in  the  original  liquid. 

Composition. — Analyses  of  human  blood  corpuscles  show  them  to 
contain  681.63  to  687.86  p/m  of  water,  and  318.37  to  312.14  of  solids. 
The  corpuscles  of  animals  contain  a  larger  proportion  of  solids.  I^ 
the  solids  the  proportion  of  organic  constituents  to  mineral  salts  is 
much  greater  in  the  corpuscles  than  in  the  plasma.  The  318.37  and 
312.14  p/m  of  solids  in  the  above  analyses  contain  respectively  3111 
and  303.17  of  organic  constituents  and  7.36  and  8.97  of  mineral. 
The  solids  consist  of  a  proteid  coloring  matter,  containing  iron» 
haemoglobin;  albumins,  including  a  nucleoalbumin  and  a  globulin; 
lecithins,  cholesterol,  fatty  acids,  and  salts. 


BLCM5D    CORPUSCLES 


659 


Blood  Coloring  Substances. — The  red  color  of  the  blood  depends 
upon  the  presence  in  the  red  corpuscles  of  a  coloring  matter,  hsemo* 
globin,  which  exists  iu  the  two  foiius  of  hssmoglobin  and  oxy- 
haemoglobin.  In  what  condition  this  pigment  exists  in  the  cor- 
pascles  is  not  clearly  established.  That  it  exists  in  soine  form  of 
combination  may  be  inferred  from  the  facts  that  in  the  corpnseles  it 
is  insoluble  in  water,  while  free  b^nioglobin,  that  of  many  animals 
at  all  events,  is  readily  soluble;  that  htemoglobiu  is  cr}'stallint%  while 
no  crystalline  structure  can  be  made  out  in  the  corpuscles;  that  tha 
oxy- com  pound  in  the  corpuscles  gives  off  its  oxygen  in  a  vacuum 
more  readily  than  ordinary  oxyha^moglobiu  does;  that  the  pigment 
in  the  corpuscles  decomposes  hydrogen  peroxid  without  itself  suffer- 
ing oxidation,  which  is  not  the  case  with  haemoglobin;  and  that  the 
native  substance  is  more  resistant  to  the  action  of  reagents  than  free 
hemoglobin.  It  certainly  exists  in  the  corpuscles  io  two  forms  of 
oxidation,  one  yielding  haemoglobin,  and  largely  predominating  in 
the  blood  in  asphyxia,  the  other  yielding  oxyhemoglobin,  and 
largely  predominating  in  arterial  blood;  the  proportion  of  the  two  in 
venous  blood  being  intermediate  between  the  above.  To  the  former 
of  these  combinations  the  name  phlebin  has  been  given,  to  the  latter 
the  name  artcrin. 

Haemoglobin  —  Reduced  Haemoglobin  —  exists  in  very  small 
amount  in  arterial  blood,  and  almost  exclusively  iu  the  blood  after 
death  from  asphyxia.  It  is  more  soluble  and  more  difficultly  crystal- 
lizable  than  oxy haemoglobin,  but  isomorphous  with  it,  although  the 
crystals  are  darker  in  color*  Its  aqueous  solution  is  purple,  and  gives  a 
spectrum  of  a  single  broad  band»  covering  D,  and  about  three-fourths 
of  the  space  between  D  and  E.  The  violet  end  of  the  spectrum  is 
less  absorbed  than  with  oxyhsemoglobin  solutions  of  corresponding 
concentration  (No.  1,  Fig.  43,  p.  661).  It  absorbs  oxygen  rapidly 
from  air,  with  formation  of  oxyhflemoglobin.  Hamioglobin  is  ob- 
tained from  oxyha^moglobin  by  bringing  its  solution  into  a  vacuum, 
by  passing  indiflFereut  gases  through  it,  or  by  the  action  of  reducing 
agents,  such  as  Stokes^  reducing  reagent,  consisting  of  an  ammoniaeal 
solution  of  ferrous  tartrate. 

Oxyhsemoglobin — is  the  form  in  which  the  blood-coloring  matter 
is  usually  obtained.  The  haemoglobins  from  the  blood  of  different 
animals  differ  from  each  other  in  several  particulars;  in  crystalline 
form,  in  solubility,  and  in  chemical  composition.  The  most  usual 
crystalline  form,  including  that  of  human  hflpmoglobin,  is  in  rhombic 
prisms  or  needles,  but  hemoglobin  from  guinea  pig*s  blood  crystal- 
lizes in  rhombic  octahedra»  and  that  from  the  squirrel  in  hexagonal 
plates*  They  differ  also  in  the  facility  with  which  the  crystals  are 
formed,  which  is  inversely  as  their  solubilities.     The  hemoglobin  of 


660 


MANUAL    OF    CHEMISTRY 


the  blood  of  the  hoi'se  and  guinea-pig  are  sparingly  soluble  and  cry 
tallize  easily,  those  of  human  blood,  ox  blood  and  pig*s  blood  ai 
very  soluble,  and  ciystallize  with  diffienlty.    The  crystals  of  oxyha^m 
globin  are  bright -red  in  eolor,  and  are  doubly  refracting.     They  eou* 
tain  from  3  to  HY/t  of  water  of  crystallization.     In  some  ha?nioglobitis 
there  are  two  atoms  of  snlfur  to  each  atom  of  iron,  in  others  there 
are  three.     The  haemoglobins  of  most  animals  contain  carbon,  hy- 
drogen, nitrogen,  iron,  sulfur,  and  oxygen;  but  those  of  certain  birds 
also  contain  phosphorus,  probably  as  an  admixture  in  the  form  of  a 
nucleic  acid  derived  from  the  nuclei.    The  molecular  weight  of  haemo- 
globin is  certainly  very  large;   a  formula  for  that  from  dog's  blood 
has  been  given  as  CKjfllliiri'iXifliFeSjjOiyi,  corresponding  to  a  molecular 
weight  of  14,129;  which  must,  however,  be  accepted  with  some  reservi^^P 
Oxyhj^moglobiu  is  more  readily  soluble  in  dilute  acids  and  alkah'e^^ 
than  in  pure  water,  insoluble  in  alcohol,  ether,  clilorcform,  benzene, 
or  carbon  disulfid,    Wlien  dried  in  vacuo  at  the  ordinary  temperaturtn^B 
it  may  be  heated  to  115°  without  Buffering  decomposition.  ^^ 

When  lueuKiglobin  from  the  blood  of  the  ox  al>sorbs  oxygen  to 
form  oxy!ui?iuoglobin,  it  does  so  in  the  proportion  of  1.34  cc,  of  oxygen 
for  each  gram  of  hsemoglobin  (at  0°  and  7G0  mm.),  which,  calculated 
for  weight,  is  equal  to  five  atoms  of  oxygen  for  three  molecnles  ofi 
haemoglobin.    The  combination  is  a  "loose**  one,  in  that  the  coiabiued 
gas  is  readily  given  off  in  a  vacuum,  or  by  passage  of  an  indi^ereut 
gas  through  the  solution.    Hfeinoglobius  are  proteids,  and  when  heated 
in  solution  to  60°  to  70°,  or  when  acted  npou  by  acids,  alkalies,  or 
certain  metallic  salts,  ai*e  decomposed  into  a  protein  aud  a  colored 
derivative  containing  iron.     The  protein,  called  globiti,  is  a  bistor, 
insoluble  in  water,  but  very  soluble  in  dilute  acids  or  alkalies,  io&ol^* 
ble  in  ammonia  in  presence  of  amnumium  clilorid*    It  is  coagulated  by 
heat,  but  the  coagulnm  is  soluble  in  acids.     Nitric  acid  precipitates  it 
iij  the  cold,  Imt  not  from  warni  solutions.     The  ferruginous  pigm^i^' 
resulting  from  the  decomposition  differs  according  to  the  degree  oi\ 
oxidation  of  the  haemoglobin.     If  oxygen  be  excluded,  the  product  iS 
haemochromogen,  but  in  presence  of  oxygen,  haematin  (p.  663)  'S 
formed.     The  proportions  of  globin  and  of  coloring  matter  obtaioeti 
frotn  hflBuioglobiu  have  been  94  per  cent  of  the  former  and  4 J  p^^ 
cent  of  the  latter. 

The  spectrum  of  oxyhapmoglobin  varies  with  the  degree  of  concen* 
tration  of  the  solution.  When  a  solution,  sufficiently  concentrated  to 
be  opaque  when  observed  spectroscopicalty  in  a  layer  of  a  given  thick" 
ness,  is  gradually  diluted,  it  first  allows  portions  of  the  red  and  wan^ 
to  pass.  On  furtlier  dilution,  ligbt  appears  in  the  gi-een,  leaving* 
Bingle  broad  band  extending  from  about  midway  between  C  and  D  ^^ 
beyond  b  (No.  2,  Fig.  43).    On  still  further  dilution  this  band  divides 


Fta.  41.  Bi>Mtrm  of:  (1)  Redne^  hmmofflobln;  (3)  OitrhiPiiiocJobln,  «oii««iatr»t«dr  (3)  Bumm,, 
^tit«:  (4)  Sune,  verj  dilute;  (5)  MethK^tnoelobiu,  in  faintly  iilkiLliD«  ■olii.tlot] ,-  (fl)  Carl>OD  mon- 
oid luPTnoglobln;  (7)  HiemorbroDioc^Ut  lia  MlkallDe  ««latlon;  (8)  Hi^inatlD,  In  tcld  lolatloii; 
tt)  HAmadD,  In  alltalliue  solntloni  (10)  Hmmatoporphrriii,  Id  acid  solntloi^ 


662  MANUAL    OP    CHEMISTRY 

into  two,  giving  the  characteristic  oxyhaemoglobin  speetram,  consisting 
of  two  bands,  one  (a)  between  D  and  E,  and  resting  on  D,  the  other 
(P)  extending  from  about  midway  between  D  and  b  to  b.  The  band 
a  is  narrower,  darker  and  more  sharply  defined  than  fi  (No.  3,  Pig. 
43).  This  spectrum  is  still  visible  with  a  solution  of  0.1  p/m  in  a 
layer  1  cm.  thick.  With  further  dilution  the  band  P  disappears  first 
(No.  4,  Fig.  43).  On  addition  of  reducing  agents  the  spectrum 
changes  to  that  of  hsBmoglobin  (No.  1,  Fig.  43) . 

Pseudohaemoglobin. — When  a  solution  of  oxyhsBmoglobin  is 
reduced  by  ammonium  sulfid  until  it  gives  the  spectrum  of  hsBmo- 
globin,  it  will  still  give  oflf  oxygen  in  the  vacuum.  In  this  condim»ii 
it  is,  therefore,  not  completely  reduced,  and  the  intermediate  form 
of  oxidation  which  is  supposed  to  exist  in  the  solution  has  been 
called  pseudohssmoglobin. 

Methaemoglobin — is  a  product  of  oxidation  of  haemoglobin, 
containing  the  same  proportion  of  oxygen  as  oxyhaBmoglobin,  but 
in  a  state  of  firmer  chemical  union,  which  may  be  expressed  by  writing 

the  formula  of  oxyhsBmoglobin  as  Hb^  I  ,  and  that  of  meth»mo- 

globin  as  Hb^Q.  MethsBmoglobin  occurs  in  transudates  and  exu- 
dates, and  in  the  urine  in  haematuria  and  hsBmoglobinuria,  and, 
particularly,  in  poisoning  by  poisons  such  as  potassium  chlorate, 
amyl  nitrite  and  the  alkaline  nitrites.  It  is  formed  from  haemo- 
globins when  blood  is  kept  in  hermetically  sealed  vessels,  or  by  the 
action  upon  them  of  many  oxidizing  agents,  ozone,  permanganates, 
chlorates,  nitrites,  etc.,  or  of  certain  reducing  agents  such  as  hydrogen 
and  the  di-  and  triphenols.  It  crj^stallizes  in  red -brown,  hexagonal 
prisms,  needles  or  plates,  which  form  a  brown -red  solution  with  water, 
which  changes  to  bright-red  with  alkalies.  It  is  very  soluble  in  water. 
Its  neutral,  or  faintly  alkaline  or  acid,  solutions  give  a  spectrum  of  a 
single  baud  between  C  and  D,  nearer  to  C  and  united  by  a  space  of 
partial  absorption  with  the  «  band  of  the  oxyhaemoglobin  spectrum, 
which  is  usually  also  present  (No.  5,  Fig.  43).  By  the  action  of 
reducing  agents  upon  faintly  alkaline  solutions  the  spectrum  changes 
to  that  of  reduced  haBmoglobin. 

Carbon  Monoxid  Haemoglobin  —  is  a  form  of  combination  of 
haemoglobin  existing  in  the  blood  of  those  poisoned  by  carbon  mon- 
oxid, or  by  illuminating  gas,  and  whose  production  is  the  cause  of 
death  by  that  poison.  It  is  a  definite  compound,  containing  one  mole- 
cule of  CO  for  each  molecule  of  haBmoglobin,  and,  being  more  stable 
than  oxyha?mo«:lobin,  is  not  oxidized  in  the  lungs,  and  thus  destroys 
the  oxygen -carrying  function  of  the  blood  coloring-matter,  but  if 
oxygen  be    present   in  great  excess  the  influence  of  mass-action  is 


BLOOD    CORPUSCLES 


GG3 


exerted  and  oxyhseraoglobin  is  slowly  regenerated.  It  is  fonued  by 
passing  CO  througli  blood,  or  through  a  solution  of  hii^moglobin  or  of 
oxyhiemoglobiii.  It  crystallizes  readily  in  forms  isomorphous  with 
oxyhjemoglobin,  but  more  bluish  m  color,  more  stable,  and  less  soluble. 
Its  solutions  are  bright -red  in  eolor  and  give  a  speetrnni  of  two  bands, 
resembling  that  of  oxyhemoglobin,  but  differing  therefrom  in  that  the 
two  bands  are  of  equal  intensity,  are  somewhat  differently  plaeed  (No. 
6,  Fig.  43),  and  also  in  that  redueing  agents  do  not  change  the 
spectrum  to  that  of  redneed  bi^uioglobin.  Carbon  monoxid  bloody 
when  mixed  with  an  equal  volume  of  NaHO  solution  (sp.  gr.  1.3) 
forms  a  bright- red  mass,  while  normal  blood,  similarly  treated,  forms 
a  dirty -brown  mass  with  a  greenish  tinge 

Carbon  Dioxid  Hsemoglobin,— A  solution  of  hjumoglobin  shaken 
with  a  mixture  of  oxygen  and  earl^on  dioxid  takes  up  both  gases, 
forming  molecular  combinations  with  each.  It  is  supposed  that  tlje 
carbon  dioxid  eombines  with  the  protein  eoniponent  of  the  coloring 
matter.  Carbon  dioxid  alone  is  also  absorbed  by  hiemoglobin  solu- 
tions, and  the  speetrnm  is  then  that  of  redneed  lia^moghrbiu,  while  a 
part  of  the  coloring  matter  is  decomposed  with  separation  of  gloliiu. 

Haemochromogen— is  formed  by  the  action  of  NaHO  upon  hamio- 
gloldn  in  complete  absence  at  oxygen,  or  by  the  action  of  reducing 
agents  upon  ha?fuaiin  in  alkaline  solution.  It  is  soluble  in  alkalies 
with  a  cherry* red  color,  and  such  sohations  give  a  spectrum  of  two 
bands,  resembling  the  osyhfemoglobin  bands  in  relati%T  intensity*  but 
placed  nearer  to  the  violet  end  of  the  spectrum  (No.  7,  Fig.  43). 

Haematin  —  is  produced  by  decomposition  of  oxyha?moglobin  by 
alkalies^  by  dilute  acids,  or  liy  mere  beating  to  BO"^,  Or  it  may  be 
obtained  by  decomposition  of  hfemin  crystals  by  NaHO,  and  precipita- 
tion by  dihite  HCl.  It  exists  in  old  transudates,  is  formed  by  peptic  or 
tryptic  digestion  of  luiMuoglobin,  and  is  met  with  in  the  urine  in 
poisoning  by  hydrogen  arsenid.  It  is  amorphous,  blue- black,  insoluble 
in  water,  dilate  acids,  alcohol,  ether,  or  chloroform;  sparingly  soluble 
in  hot  glacial  acetic  acid  with  ffn*mation  of  lia^'uiin;  soluble  in  acidn* 
lated  alcohol  or  ether,  very  soluble  in  dilute  idkalies.  Its  aHialine 
solutions  are  dichro'ic,  red  l>y  reflected  light,  green  by  transmitted^  its 
acid  solutions  are  brown.  In  acid  solution  in  alcijlud  or  ether  it  gives 
a  spectrum  of  four  bands  (No.  8,  Fig,  4"^) :  a,  the  ihu'kest,  near  to  C, 
and  extending  about  one- third  to  D;  f^  resting  on  D,  narrower  and 
paler  than  «;  y  between  D  and  E,  nearer  to  E,  brf>ader  and  paler  than 
tt;  5  the  broadest  of  the  four,  a  pale  Viand  whose  center  is  midway 
between  b  and  F,  and  covering  about  three-quarters  of  the  space. 
The  interval  between  y  and  ^  is  partly  absorbed.  In  alkaline  soluHon 
hfematiu  gives  a  spectrum  of  a  single  band,  extending  from  nenr  f*  to 
beyond  D  (No.  9,  Fig.  43). 


664 


CHEMISTRY 


The  empirical  formula  of  ba^matin  is  C32H32N4Fe04.  Wlieu  lieateJ 
dry  it  gives  off  pyrrole.  By  oxidation  with  potassium  chromate  in 
glacnal   acetie   aeid  solution   it  yieUk  a  mouobaj^ic  imid-aoid,  called 


CH3.C.CO 


/NH,  which  by  saponification  with 


1 

I 


hsematinic  acid, 

MgO  yields  the  anhydrid,  HOOC.CsHt^co^O,  of  the  pareut  tribasic 

acid,  H00C.C5H7\f'O(jHi  ^hi^h  acids  are  themselves  derivatives  of 
hfemopyrrole,  or  metbylpropylpyrrole  (p.  510),  The  same  acids,  ol^| 
tljeir  isomeres,  are  similarly  obtained  from  ha?matoporphyriu»  biliru- 
bin, and  nrobilin,  Ht^^matiii  dissolves  in  concentrated  K2SO1,  losiug 
its  iron,  and  the  product  by  hydration  is  converted  into  htematopor- 
phyrin. 

Haemin — is  a  compound  of  h^matiu  with  chloriu  or  lodin,  whose 
formation  is  utilized  as  the  most  characteristic  test  for  blood 
forms  red -brown  crystals,  which,  when  perfect,  are  rhombie  prism 
insoluble  in  water,  alcohol,  ether,  dilute  aeids  or  chloroform,  solnh 
without  decomposition  in  hot  glacial  acetic  acid,  soluble  with  decoin- 
position    in   acidulated   alcoliol   or  in  dilute  NaHO  solution.      Thi 
crystals,  known  also  as  Teichmann's  crystals,  are  best  obtained  as 
follows:   a  fragment  of  the  dried  stain  is  placed  upon  a  glass  sHdei 
upon  which  a  very  minute  drop  of  dilute  sodium  chlorid,  or  iodi 
solution  has  been  previously  evaporated,  and  covered  with  a  cove 
glass.     Glacial  acetic  acid  is  then  rnn  in  beneath  the  cover,  and  th( 
slide  cautiously  heated  over  a  very  small  flame  until  bubbles  jusl 
begin  to  appear,  when  the  slide  is  raised  about  three  iuches  abo 
the  flame  and  kept  warm  for  a  few  minutes,  while  the  loss  of  acid  b; 
evaporation  is  supplied  by  fresh  glacial  acetic  acid  placed  at  the  ed 
of  the  cover  with  a  slender  glass  rod.     The  slide  is  now  allowed 
cool,  and,  during  cooling  and  evaporation  of  the  acid,  examined  with 
a  one- fifth  inch  objective.     The  crystals  are  usually  found  near  the 
edge  of  the  cover,  or  imprisoned  in  the  remains  of  the  clot,  and  are 
generally  all  in  a  small  space,  while  the  remainder  of  the  preparation 
is  free  from  them.     The  acid  must  not  be  allowed  to  boil,  or  the 
crystals  may  be  mechanically  carried  out  from  under  the  cover.     The 
formation  of  the  crystals  under  these  conditions  may  be  accepted  as 
certain  evidence  of  the  presence  of  blood- pigment,  but  their  noti- 
formation  is  not  evidence  of  its  absence.     They  cannot  be  obtained 
if  the  stain  contains  iron -rust,  or  has  been  treated  with  chlorin  or 
with  certain  kinds  of  soap.    In  place  of  acetic  acid  and  a  chlorid, 
Htryzowski^s  reagent  may  be  used  to  advantage,  as   it  softens  old 
stains  more  readily.    It  consists  of  a  freshly  prepared  mixture  of  equal 
volumes  of  glacial  acetic  acid,  alcohol,  and  water  to  which  a  drop  or 


4 


BLOOD    COKPUSCLES 


665 


>f  hydriodic  aeid  solution  are  added.  Stvrnetitiif'S  the  crystals  may 
>tained  even  from  stains  on  iron,  by  prolonging  the  (^oiitaet  with 
the  acid  or  reagent. 

Hffiinin  was  formerly  considered  tfi  he  a  simple  ehlorid  (or  iodid) 
of  hffitiiatin.  Its  chlorin  is,  however,  in  combination  with  carbon  or 
with  iron,  and  may  be  almost  completely  removed  by  washing  with 
hot  water.  Its  molecule  contains  two  hydroxyls,  which  are  readily 
replaceable  by  a  Iky  Is  or  acidyls.  As  usually  prodnccd  in  the  manner 
above  descril>ed,  the  crystals  are  those  of  a  nionoaeetyl  ester,  acethat- 
matin,  C3'iH3o(<^*2H:jO)03N4ClFe,  corresponding  to  a  hannin  of  the  com- 
position CwHiiO.iN^ClFe.  In  this  compound,  however,  the  acetyl  is 
not  substituted  in  one  of  the  hydroxy  Is,  which  are  replaceable  to  form 
dialkyl  deriva fives  m  acethannin  as  thej'  are  in  htemin. 

Haematoporphyrin  —  is  an  isomere  of  bilirubin  (pp,  637,  641), 
therefore  containing  no  iron,  Ca^HrioNiOo,  and  is  derived  from  hi^- 
matinr  C32H32N4FeO^+2H-jO=C3aH:iflN40«+Fe.  It  occurs  normally 
in  urine  in  minute  quantity,  and  is  notably  increased  in  poisonings 
by  sulfonaL  It  forms  a  coniponnd  with  IICl  which  crystallizes  in 
long,  red -brown  needles,  and  is  precipitated  from  its  HCl  solnti<ni 
by  partial  neutralization  and  addition  of  sodium  acetate,  as  an  amor- 
phous, brown  powder.  It  is  solnble  in  dilate  acids  or  alkalies,  the 
acid  solutions  having  a  purple  color,  and  the  alkaline  solutions  being 
red.  Reducing  agents  convert  it  into  urobilin,  and  when  injeticd 
into  the  circulation  of  rabbits  it  is  partly  eliminated  in  that  form. 
In  acid  solution  it  gives  a  spectrum  of  two  bands  (No.  10,  Fig.  43), 
P,  the  narrower  and  less  intense,  between  C  and  D,  nearer  to  D;  and 
tt,  much  darker  and  broader,  about  midway  between  D  and  E,  with  a 
space  of  less  complete  absorption  extending  nearly  to  D.  In  alkaline 
solution  it  gives  a  four -band  spectrnni,  one  {«)  between  C  and  D,  a 
broader  one  O)  over  D,  a  third  (y)  between  D  and  E,  extending 
nearly  to  E,  and  a  fourth  (^)  between  b  and  F.  On  addition  of 
alkaline  zinc  ehlorid  solntitui  the  bands  a  and  §  gradually  fade  out, 
leaving  ^  ami  y. 

Haemato'idin  —  another  decomposition -product  of  hemoglobin,  is 
identical  with  bilirubin  (p.  637), 

The  solids  of  the  stroma  (p.  656)  of  raamnmlian  corpuscles  repre- 
sent but  a  small  fraction  of  their  weight.  Tlie  proteins  arer  a 
globulin,  which  is  possiliiy  ideutieal  with  serum  ghihulin,  and  a 
nncleoalburain.  The  nucleated  cells  of  the  birds  and  fishes  contain  a 
nucleoproteid,  which  forms  a  mucilaginous  solution  with  a  10  percent 
solution  of  NaCl,  but  the:  yon'UncleatL'd  cells  of  the  mammalia  con- 
tain no  similar  substance.  The  proportion  of  non-proteid  proteins  to 
hfpmoglobin  is  much  greater  in  nucleated  than  in  non -nucleated  cor- 
puscles.   Thus  human  corpuscles  contain  in  1»000  parts  868  to  943  of 


066 


KANUAL    OF    CHEMISTRY 


haejiiogbbia  against  122  to  51  parts  of  albumius,  while  in  serpents' 
blood  the  proportiou  is  467  lupmoglobiii  to  525  of  albimiins.  The  red 
corpuscles  of  frogs*  blood  also  appear  to  contain  libriuogeu,  or  a  related 
protein.  Lecithins  exist  in  human  corpuscles,  in  the  proportion  of 
3.5  to  7.2  p/ra»  and  cholesterol  to  the  amount  of  about  2,5  p/ni.  The 
total  ash  of  human  corpuscles,  iueludiug  the  iron  derived  from  the 
htemoglobin  and  the  phosphoric  acid  derived  from  the  lecithins,  con- 
stitute 3.5  to  3.7  p/m  of  their  weight.  The  salts  vary  in  different 
animals.  In  the  corpuscles  of  the  pig,  ox,  horse  and  dog  the  sodium 
compounds  are  notably  more  abundant  than  those  of  potassium,  while 
human  corpuscles  contain  sodium  compounds  equivalent  to  0.24  to 
0.65  Na-iO,  and  potassium  compounds  equivalent  to  1.41  to  1,59  K2O, 
The  mineral  salts  present  are  potassium  and  sodium  chlorids  and 
phosphates,  with  mere  traces  of  magnesium  salts.  Calcium  com- 
pounds, so  important  in  the  serum,  are  entirely  absent  from  the 
corpuscles. 

The  leucocytes,  or  white  corpuscles,  are  rounded,  colorless  pro- 
toplasmic masses,  endowed  with  the  power  of  amoeboid  movement, 
having  no  limiting  membrane,  which,  ou  addition  of  water  or  of  1% 
acetic  acid,  are  seen  to  have  from  one  to  four  nuclei,  round  or 
irregular  in  outline.  They  are  less  numerous  than  the  red  corpus- 
cles, the  average  proportion  between  the  two  being  from  1:350 
1:500;  but  their  number  varies  greatly  under  varying  normal, 
well  as  pathological,  conditions.  Histologically  they  are  divided  in 
several  groups,  the  members  of  which  differ  from  each  other  in  size, 
in  appearance,  and  in  their  behavior  towards  staining  agents.  Al 
though  no  differences  in  chemical  composition  between  these  several 
kinds  of  white  corpuscles  are  known  to  exist,  tlie  differences  in  their 
behavior  towards  stains,  which  are  in  reality  chemical  reagents, 
render  it  hif^hly  prol>al>le  that  they  aj'e  not  chemically  identical 
Indeed  our  knowledge  of  the  eliemical  composition  of  the  leucocytes 
is  f ragmen tarj\  The  different  action  of  staining  agents  upon  nuclei 
and  protoplasm  indicates  differences  in  the  nature  of  their  constit- 
uents. The  most  abuudaut  protein  in  the  leucocytes  is  the  nucleo- 
proteid  nucleohiston  (p.  591),  soluble  in  water  and  precipitated  Uy 
acetic  acid.  Besides  this  tliey  contain  a  mucin -like  substance  which 
swells  to  a  mucilaginuus  mass  ou  contact  with  alkalies,  and  is  vrry 
similar  to,  if  not  identical  with,  the  hyaline  substance  of  Rovida, 
which  exists  in  pus  cells,  and  two  cell -globulins,  coagulating  at  50^ 
and  7S°,  The  prothrombin  {p.  6G8),  which  is  furnished  by  the  leae(»- 
cytes,  may  be  derived  from  oue  of  these  proteins.  Glycogen,  fat, 
cholesterol  and  lecithins  are  also  present  in  small  amount.  The  total 
phosphorus  in  the  leucocytes  is  3.01  per  cent,  and  their  total  nitrogen 
15.03  per  cent. 


1 

I 


THE    BUX)D    AS    A    WHOLE 


6G7 


Very  little  is  koowii  of  the  ohemieal  en m position  of  the  plaques 
beyoiid  the  probability  that  they  consist  largely  of  albumins  and 
nucleoproteins, 

THK    BLOOD    AS    A    WHOLE. 

*  The  color  of  the  blood  is  bright -red  if  arterial,  bluish  *red  if 
venous,  bright  cherry- red  in  poisoning  by  carbon  monoxkl,  brownish* 
red  in  poisoning  by  potassium  chlorate,  auilin,  or  nitro- benzene, 
dark  purple* red  after  death  from  asphyxia.  It  is  opaqne,  even  in 
thin  layers.  It  is  salty  in  taste;  and  its  odor  is  similar  to  that  of 
the  animal,  being  more  pronounced  after  addition  of  H2SO4;  sp.  gr. 
1045  to  1075.  The  reaction,  which  is  alkaline,  cannot  be  determined 
in  the  usual  way,  owing  to  the  color  of  the  blood.  It  is  shown  by 
allowing  a  few  drops  of  blood  to  reuaain  for  about  five  minutes  upon 
a  slab  of  plaster  of  Paris  which  has  been  previously  soaked  in  a 
neutral  solution  of  azolitmin  and  dried,  when,  on  washing  off  the 
blood,  a  blue  stain  remains.  The  alkalinity  of  the  blood  depends 
in  part  upon  the  presence  of  alkaline  bicarbonates  {p.  690)  and  phos* 
phates,  and  in  part  upon  alkaline  protein  compounds.  Tht*  normal 
degree  of  alkalinity  of  human  blood  has  been  given  by  different 
observers  as  equal  to  from  3.38  to  5.95  p/m  of  sodium  carbonate, 
or  2.55  to  4.5  p/m  of  sodium  hydroxid.  Usually  the  limits  of  norjunl 
variation  are  placed  at  3.3  to  5.3  p/m  NajCOa,  or  2.5  to  4.0  p/m 
NaHO.  The  alkalinity  of  the  blood  rapidly  diminishes  after  its 
removal  from  the  circulation,  by  reason  of  the  generation  of  acids, 
which  bus  led  to  results  lower  than  the  above,  some  authors  giving 
the  nornuil  limits  as  low  as  1.8  to  3,0  p/m  NaHO,  Normal ly  the 
degree  of  t^lkalinity  is  greater  in  men  than  in  women  and  children; 
and  is  diminished  after  violent  muscular  activity.  It  increases  with 
activity  of  the  stomach  digestion,  and  subsetjuently  diminishes  from 
absorption  of  hydrochloric  acid  and  peptones  from  the  intestine. 
Patbologieally,  it  is  diminished  in  antemia,  lenke^mia,  ursemia,  dia- 
betes, hepatic  diseases,  high  fevers,  and  in  aeidism  due  to  adminis- 
tration of  mineral  acids  or  to  the  generation  of  organic  acids  in  the 
body.  It  is  increased  by  administration  of  alkalies,  by  cold  baths, 
and  in  phthisis,  erysipelas,  and  septicaemia  (p,  676)* 

The  change  of  coagulation,  which  the  blood  undergoes  shortly 
after  being  drawn  from  the  blood-vessels,  is  a  chemical  phenomenon 
dependent  upon  physical  conditions,  the  precise  nature  of  which  has 
not  been  satisfactorily  explained.  Coagulation  takes  place  with  dif- 
ferent degrees  of  rapidity  in  the  blood  of  different  animals,  and  with 
different  individuals  of  the  same  race.  In  human  blood  it  usually 
begins  in  2-3  minutes  after  the  blood  is  drawn,  and  it  results  in 
the  formation  of  a  jt'tly-like  mass  in  7-8  miuntes.     If  it  take  place 


MANUAL    OP    CnKMISTHY 


rapidly  the  clot  is  unifomi  ia  appearance,  but  if  it  be  delayed  tlie 
corpuscles  sink,  the  red  more  rapidly  than  the  white,  and  the  upper 
part  of  the  elot,  the  "buffy  coat"  or  ^^erusta  phlogfistiea,"  is  pale  in 
color,  and  contains  few  red  corpuscles  and  many  white  ones.  Coag- 
nlation  is  delayed  by  cold,  dimiuished  oxygen* content,  increased 
carbon  dioxid,  the  presence  of  acids,  alkalies,  animoniaeal  salts, 
oxalates,  flnorids,  egg -albumin,  sngar,  dextrin,  glycerol,  albumoses, 
snake- poison,  toxalbumins,  or  an  infusion  of  the  month  of  the  leech, 
or  by  collection  in  oil.  It  is  accelerated  by  warmth,  contact  with 
air,  whipping,  contact  with  solids  to  which  it  adheres,  or  addition  of 
leucocytes,  nucleoproteids,  or  extracts  of  lymphatic  glands,  testicles, 
or  thymus. 

As  to  the  cause  of  coagulation,  and  particularly,  its  non -coagula- 
tion in  the  vessels  during  life,  opinions  differ.  The  following  facts, 
in  addition  to  others  already  discussed,  bear  upon  the  question:  (1) 
the  blood  does  not  coagulate  while  in  contact  with  living,  healthy 
blood-vessels;  (2)  it  remains  tluid  in  a  ligated  section  of  a  vein, 
removed  from  the  body;  (3)  it  coagulates  rapidly  when  collected  in 
a  vacuum  over  mercury;  (4)  it  does  not  coagulate  when  collected 
through  an  oiled  or  vaselined  cauula  into  a  similarly  prepared  vessel; 
(t5)  in  such  vessels  it  docs  nor  coagulate  when  stirred  with  an  oiled 
or  vaselined  glass  rod;  but,  (6)  it  does  coagulate  when  stirred  with 
an  unoiled  rod  ;  (7)  under  the  conditions  of  5  and  6»  coagulation 
begins  when  a  film  of  solid  forms  upon  the  surface  by  drying,  or  if  a 
small  quantity  of  dust  be  present  in  the  oil  or  vaseline;  (8)  it  coagu- 
lates in  living  blood-vessels  when  their  internal  surfaces  become 
roughened,  or  in  presence  of  foreign  material  with  rough  surfaces. 
From  these  facts  it  may  be  iufeiTed  thnt  the  ebaoge  does  not  depend 
upon  the  presence  of  air,  but  that  it  does  depend  in  some  way  upon 
the  physical  condition  of  adhesion,  as  the  formation  of  crystals  may 
be  provoked  in  a  strong  solution  of  a  salt  by  the  addition  of  even  a 
minute  particle  of  dust,  and  that  there  exists  in  the  blood  a  condition  of 
unstable  equilibrium  comparable  with  that  in  supersaturated  solutions. 

As  to  the  nature  of  the  chemical  changes  involved  in  coagulation, 
opinions  differ.  It  is  universally  aduiitted  that  the  corpuscles,  par- 
ticularly the  leucocytes  and  plaques,  cootaiu  a  zymogen,  prothrombin, 
from  which  an  enzyme,  thrombin,  is  produced.  It  is  also  generally, 
though  not  universally,  couceded  that  this  enzyme  causes  coagulation 
by  splitting  fibrinogen  into  the  insoluble  fibrin  and  the  soluble  fibrino- 
globulin;  and  that  the  continued  existence  of  the  enzyme  in  the  circu- 
lating blood  causes  death  by  thrombosis.  The  presence  of  calcium 
salts  is  necessary  to  coagulation,  as  is  shown  by  the  prevention  of 
such  action  by  the  removal  of  calcium  by  oxalates  or  other  precip- 
itants  of  that  metal,  and  by  the  fact  that  oxalate  plasma  regains  its 


I 


BLOOD  SERUM  AND  BACTERTAL  ACTION 


6C9 


power  of  eoagutation  on  restoration  of  calcium  salts.  A^  the  separated 
fihrin  coiitiiiiis  n  considerable  ainuiiiit  of  ealciiini,  it  has  been  suggested 
that  during  eoaguiation  the  ealeium-eontaiuing  thrombin  gives  up  its 
caleiiim  to  tibriuogeii,  with  the  formation  of  tibrio,  while  prothromhiu» 
which  has  a  less  ealeiuoi-eotiteiit  than  thrombin,  is  regenerated,  and 
may  in  tnrn  regenerate  tljromhin  by  eorubi nation  with  ealeiam  salts 
(Peekelbaring),  Aecordiug  to  another  explanation  of  the  ebemisTn 
of  the  process  the  leucoiiuelein,  or  nueleic  aeid  of  the  nneleohistou  of 
the  leucocytes,  in  the  presence  of  caleinni  salts,  decomposes  fibrinogen 
w^ith  formation  of  an  albnnios*^-like  substance  (fibrinoglobnlin)  and 
a  hypothetical  substance,  called  thrombosing  which  latter,  combining 
with  calcium,  forms  fibrin  (Lillienfeld).  This  latter  view*  so  far  as 
cHincerns  the  activity  of  Jineleohiston  in  the  process,  is  supported  by 
the  fact  that  solutions  of  fibrinogen,  not  spontaneously  eoagulable, 
are  coagulated  on  addition,  not  only  of  blood-serum,  but  also  of  cells, 
uch  as  yeast,  spermatozoa,  etc.,  containing  nneleoproteids.  These 
lews  may  be  reeunciled,  with  the  exception  of  the  supposed  existence 
of  thrombosin,  upon  the  supposition  that  prothrombin  and  uucleo- 
biston  are  identical  either  in  kind  or  in  action. 

BLOOD  SERUM  AND  BACTERIAL  ACTION. 

A  brief  notice  of  the  bacteriologieal  investigations  of  the  propa- 
Ifatlon,  inhibition  and  effects  of  bacterial  life  in  blood  serum ,  which 
Lave  led  to  results  of  tlie  greatest  importance  in  i)athology  and  in 
medicine,  is  of  interest  in  this  place  in  so  far  as  such  actions  are 
probably  chemical  in  their  nature. 

Immunity— Antitoxins, — We  have  seen  (p.  572)  that  pathogenic 
bacteria  produce,  as  endogenous  poisons  which  are  the  agents  causing 
the  manifestations  of  disease,  substances  called  toxins,  which  are  in 
all  probability  chemical  individuals,  although  nothing  is  as  yet  known 
of  their  composition  or  constitution.  The  toxins  vary  in  the  intensity 
of  their  action,  as  do  poisons  of  other  origins,  and  for  each  species 
there  is,  for  a  given  kind  of  animal,  a  certain  minimum  quantity 
which  is  capable  of  causing  death  under  given  conditions,  a  certain 
minimum  Iff  ha!  (Jose.  With  certain  poisons,  notably  the  toxalbumins 
(p.  572),  the  administration  of  repeated,  gradually  increased  doses 
establishes  a  tolerance  of  the  poison  in  the  individual^  ^o  that  in  some 
instances  ten  times  the  lethal  dose  may  be  injected  without  causing 
a  fatal  result.  The  same  is  time,  even  more  markedly,  with  toxins. 
An  animal  in  which  such  a  tolerance  has  been  established  is  said  to  be 
immunized  against  tlie  action  of  a  given  toxin  or  othei  poison.  The 
immunity  is  also  sperifir,  i,  e,,  it  is  established  only  for  that  partic- 
ular toxin  which  hns  been  administered. 


670 


MANCAL    OF    CHEMISTKY 


As  a  certain  defiuite,  though  small,  amount  of  a  toxin  ar  other] 
poisDU  is  necessary  to  prodiioe  Ititbal,  or  even  trixie,  effects  in  anjrj 
annual,  there  exists  a  certain  degree  of  natural  immunity  even  in  nou- 
inimunized  individuals,  to  which   the  acquired  immunity  is  super- 
added ill  those  which  have  been  irauiunized.    Thiy  acquired  toleranc©! 
iu  the  case  of  exogenous  poisons  is  usually  small  in  comparison  to  thej 
natural,  but  with  the  toxins  and  toxalbumins  it  is  frequently  very| 
much  greater.    If  the  serum  of  an  animal  immunized  by  administra- 
tion of  a  toxin  be  injected  into  anotlier  individual  of  the  same  species  J 
immunity  is  also  established  iu  the  second  aninuiK    The  first  is  saidj 
to  have  been  actively  imuiuuized,  the  second  passively* 

Although  the  rationale  of  the  slow  establishment  of  tolerance  ol 
arsenic  or  of  the  still  greater  tolerance  of  raorphin  has  not  been  satis- 
factorily explained,  there  is  no  reason  to  believe  that  these  are  pro* 
duced  by  any  action  occurring  in  the  blood,  but  rather  by  somel 
modification  of  these  cell  constituents  upon  which  these  poisons  exertj 
tfieir  action.    It  is  also  probable  that  in  a  certain  degree  tlje  cells  inaj 
become  similarly  protected  from  the  action  of  certain  toxins,  par-l 
tieularly  the  intracellular  toxins  which  are  more  slowly  liberated  oa 
destruction  of  the  bacterial  cells.     But  the  fact  that  a  solution  of  a 
toxin,  when  mixed  in  vitro  with  the  serum  of  an  immuuized  animall 
and  injected  in  sufficient  quantity  into  a  uou- immunized  animal,  fails] 
to  produce  the  toxic  effects  which  it  does  produce  when  injected  with-l 
out  sueii  admixture  proves  that  some  substance  has  been  formed  ia 
the  serum  which  enters  into  combination  with  the  toxin  to  produce 
an  inert  combination. 

Any  agent  which  deters  the  action  of  the  bacteria  or  of  their  tox- 
ins in  the  system  is  called  an  anti  agent,  or  auti  body.    The  antitoxins, 
are  anti  bodies  acting  as  above  indicated  upon  the  toxins,  both  being 
in  all  probability  chemical  iudividnals.    The  antitoxins  are  therefore! 
only  efficient  in  conditions  of  toxaemia,  acting  upon  soluble  toxins  aaj 
in  diphtheria, 

Cytotoxins  —  Lysins  —  Agglutinins  —  Precipitins.^ — Id  producing  ^ 
immunity  the  antitoxins  are  consumed,  and  the  action  between  anti- 
toxin and  toxin  takes  place  in  certain  quantitative  relations.    There- 
fore the  neutralization  of  toxin  by  antitoxin  may  be  considered  as  aj 
purely  chemical  process,   comparable  to  the  uentraHzation  between] 
acids  and  bases.     But  there  are  other  substances  produced  in  blood! 
serum  which  effect  immunity  by  destruction  of  bacterial  and  other] 
cells,  or  by  establishing  conditions  unfavorable  to  their  development,  [ 
The  power  of  the  leucocytes  to  absorb  and,  as  it  were,  digest  bacteriA 
and  other  foreign  cells  in  the  blood,  referred  to  as  phagocytosis,  was 
the  earliest  observed  action  of  this  character,  which,  however,  differs  ( 
iu    its    nature    from    the   more    distinctly  chemical    process    of  cell 
destruction  caused  by  certain  more  recently  discovered  soluble  agents. 


BLOOD  SERUM  AND  BACTERIAL  ACTION 


C71 


While  butiiau  l>lood  may,  with  suitable  preeautions.  be  transfused 
from  the  circulatiou  of  otie  individoal  to  that  of  auotlier  witboiu  the 
occurrenee  of  any  untoward  symploiii,  the  transfysiou  of  blood  from 
one  speeies  of  animal  into  the  eireidation  of  another  of  a  different 
species  is  followed  by  toxic  eifeets,  prominent  among  whieh  are  the 
formation  of  elots  and  the  oeeurreiiee  of  hannoglobiunria,  which  indi- 
cate that  the  blood  of  a  given  kind  of  animal  c^ontaioH  some  substauce 
whieh  exerts  a  disintegrating  action  iipou  the  red  corpuscles  of  the 
blood  of  animals  of  diiferent  species*  That  this  haemolytic  action  is 
only  indirectly  dependent  upon  morphologieal  elements,  and  h  cauat^d 
b}'  a  substance  in  solution;  is  shown  by  the  fact  that  it  is  exerted  hi 
%^tro  by  the  filtered  serum,  the  liquid  becoming  reddened  by  solution 
of  the  hflemoglobin  liberated  by  disintegration  of  the  corpuscles,  which 
also  diminish  in  number.  It  has  also  been  demonstrated  by  bacteri- 
ological methods  that  nortnal  blood  seruni,  and  milk  also,  is  to  a  cer- 
tain extent  destructive  of  bacterial  cells. 

Substances  which  cause  such  destruction  of  cells  are  called  cyto- 
iysins,  or  cytotoxins.  Those  which  act  upon  blood  corpuscles  are 
dtstinguished  as  haemolysins,  while  those  affecting  bacteria  are  called 
bacteriolystns. 

The  cytolytic  action  of  blood  serum,  whether  ha^molytic  or  bacter- 
iolytic, is  greatly  increased  by  immunization,  the  increase  being  in 
both  cases  specific.  Thus,  after  repeated  injections  of  small  quantities 
of  ox  blood  in  man,  the  serum  of  the  human  blood  becomes  much 
more  actively  hai'inolytic  to  the  corpuscles  of  ox  blood,  but  not  to 
those  of  other  kinds  of  animal,  than  is  that  of  normal  human  blood. 
Similarly,  after  repeated,  graduated  injections  of  cultures  of  the 
typhoid  bacilli,  the  serum  of  the  Idood  of  the  animal  so  immunized 
exhibits  a  greatly  increased  bacteriolytic  action  to  the  typhoid  bacilli, 
but  to  those  bacteria  only,  Prom  these  facts,  and  from  the  further 
fact  that  more  than  one  cytolytic  activity  may  be  developed  in  the 
same  serum,  it  tnay  be  inferred  that  the  several  Iysins  are  distinct 
substances,  which  are  produced  in  greater  abundance  during  im- 
munization, 

Cytolysis  by  immunized  sera  is  not  the  result  of  the  action  of  a 
single  substance,  but  of  the  joint  action  of  two  substances.  If  an 
activated  ha?molytic  serum  be  heated  to  60*^  it  loses  its  activity,  but 
it  again  becomes  active  when  mixed  with  normal  serum.  There  are 
therefore  two  participants  in  the  actiou :  one  a  substance  destroyed  l)y 
heat,  and  therefore  said  to  be  thermolabile,  which  exists  in  normnl 
senim,  and  another,  capable  of  wilhstanding  a  temperature  of  60  , 
and  therefore  said  to  be  thermostable,  which  is  produced  during 
imnninization. 

A  similar  participation  of  two  agencies  in  bacteriolysis  is  demon- 


672 


MANUAL    OF    CHEMISTRY 


d 


6 1 rated  by  what  is  known  as  Pfeiffer*s  phenomenon:    The  seram  oB 

an  anitnal  imrnnnized  to  cholera  exhibits  very  little  bacteriolytic  actioij 
in  pitro  to  tlxe  cholera  sptrUlnm,  but  becomes  actively  destructive 
thereof  either  when  injected  into  the  peritoneal  cavity  of  the  animal 
or  when  mixed  in  vitro  with  normal  Bernm* 

Tlmt  participant  m  effecting  cytolysis  which  exists  in  the  normal 
serutii,  tliat  which  is  tlicrmolabile,  is  called  the  complement,  or  addi 
ment,  or  alexin.     That   which  is  developed  during    inimnnization 
known  as  the  immune  body,  or,  because  it  is  theoretically  suppose 
to  act  as  a  mcaus  of  nnion  i  jet  ween  the  complement  and  the  cell  (.si 
below)  the  intermediate  body,  or  the  amboceptor. 

As  antitoxins,  which  oppose  the  action  of  toxins,  may  \ye  developed 
by  immunization,  so  antihsemolysins  may  l>e  similarly  produced, 
%vhich  oppose  tlie  action  of  hipniolysios. 

Agglutinins  do  not  destroy  blood  corpuscles  or  bacteria,  but  can 
them  to  ntjjghitinafcej  or ''chimp''  together.     Marked  agglutination  of 
blood  corpuscles  is  produced  by  toxalbnrains,  and  has  been  observed 
in  a  case  of  poisoning  by  potassium  chlorate. 

Bacterial  agglutinins  are  developed  by  immunization,  and  are 
specific  in  their  action.  These  facts  are  utilized  in  the  Widal  test  for 
typhoid  fever,  in  which  the  result  is  considered  as  afiirmative  of  the 
existence  of  the  disease  when  clumping  and  loss  of  motilitj'  of  the 
bacteria  are  observed  in  a  mixture  of  the  serum  of  the  patient  and  a 
boil  Ion  cnltni'e  of  typhoid  l)acilli. 

Precipitins. ^The  serum  contains  substances  which  form  clouds  or 
precipitates  with  certain  constituents  of  the  sera  of  animals  of  different 
species.  This  action,  very  slight  with  normal  blood,  may  be  greatly^M 
increased  by  a  method  akin  to  immunization.  Thus  if  a  rabbit  receiv^^l 
six  or  eight  intravenous  of  intraperitoneal  injections  of  human  blood 
at  intervals  of  two  or  three  days,  the  serum  obtained  from  the  blood 
will  produce  a  distinct  precipitate  when  mixed  with  a  clear  and  highly 
diluted  solution  of  human  blood  in  normal  salt  solution.  This  action 
is  specific  within  certaiu  limits.  The  serum  of  the  "humanized*'  rabbit, 
^vhile  producing  a  decided  precipitate  with  human  blood,  gives  but  a 
faint  reaction  with  that  of  certain  monkeys,  a  mere  cloudiness  with 
those  of  the  horse,  ox,  sheep  and  dog,  and  no  effect  with  those  of  the 
many  other  kinds  of  blood  which  have  been  examined.  Whatever  i\ 
is  that  reacts  with  the  precipitin  withstands  desiccation  and  puti-efae 
tion,  as  the  react  if  m  is  given  by  dried  or  putrid  blood.  These  facta 
are  utilized  in  the  "precipitin  test"  for  human  blood. 

Chemical   Theory  of   Anti    Bodies  ^  Ehrlich's  Theory.  —  Thii 
theory  was  first  adv'anf*ed  by  Elirlich  in  explanation  of  the  method  of 
assimilation  of  food  materials  by  cells.     Tlie  cells  are  supposed  to  be 
made  up  of  two  parts:    (1)  a  central  portion,  consisting  of  a  great 


r 


BLOOD    SERUM    AND    BACTERIAL    ACTION 


673 


I 


I 


I 


unrnber  of  TOoIeeules  of  eoinplrx  stnioture  and  great  variety,  wliose 
interaction  upon  each  other  and  upon  the  foodstuffs  constitute  the 
reactions  of  cell  nietaholisin;  (2)  a  peripheral  portion  consisting  of 
molecules  having  groups  capable  of  entering  into  combination  with 
aflinitive  groups  of  the  foodstuff  molecules,  brought  to  tbem  by  the 
nutrient  circulating  fluids^  and  thereby  "anchoring"  these,  and  sub- 
sequently transferring  them  to  the  central  molecules,  to  be  by  them 
elaborated. 

These  anchoring,  or  haptophorus  groups  {(tTrrttv^to  fasten),  of 
the  peripheral  molecules  are  supposed  to  be  of  different  kinds,  having 
different  affinities,  for  the  anchoring  of  the  several  varieties  of  food 
molecules,  fats,  carbohydrates,  etc..  and  are  considered  as  analogous 
to  the  lateral  chains  of  cyclic  organic  compounds,  hence  the  theory  is 
also  known  as  the**sidc  chain  theory,"  For  example:  In  phthalainic 
acid  (formula,  p  478),  thecarboxyl  constituting  one  lateral  chain  and 
the  amido  group  contained  in  the  other  are  each  capable  of  reacting 
with  such  other  molecules  as  contain  groups  which  are  reactive  with 
them,  and  of  so  fixing  other  groups  to  the  central  ring.  A  closer 
analogy  is  found  in  the  more  complex  morphin  molecule,  whose 
characteristic  action  upon  the  cells  of  the  respiratory  center  apparently 
depends  upon  a  linking  action  with  some  constituent  of  the  cells 
through  the  phenolic  hydroxy  I  wliich  is  one  of  its  lateral  chairs  (for- 
mula, p.  567),  for  when  this  is  closed,  as  in  morphylsnlfnric  acid  {p. 
563) »  the  so  modified  niorphiu  molecule,  otherwise  unchanged,  no 
longer  exerts  this  action. 

The  lateral  chains  are  called  receptors,  of  which  the  haptophorons 
group  may  constitute  only  a  part^  more  or  less  infiuenced  in  its  affinities 
by  the  remainder  of  the  chain,  just  as  in  the  two  lateral  chains  of 
phthalamie  acid  the  amido  group  would  constitute  one  haptophorons 
group,  nnintiuenced  by  the  methylene  which  forms  the  remainder  of 
the  chain,  while  in  the  carboxyl,  which  is  the  second  receptofi  the 
hydrogen  owes  its  anchoring  power,  or  reactivity,  to  association  w^ith 
oxygen. 

In  order  that  the  food  molecule  may  be  fixed  to  the  haptophorons 
group  of  the  cell  molecule^  it  must  itself  possess  a  group  afiRnitive  with 
the  anchoring  group  of  the  receptor,  and  this  correlation  between  the 
haptophorons  groups  of  cell  and  food  molecules  nvnst  extend  to  simi- 
larity of  stereometric  conformation,  if  this  may  vary,  for,  as  we  have 
seen  (p.  600),  the  cells  of  certain  bacteria  can  assimilate  sugars  and 
other  optically  active  substances  of  one  conformation,  but  not  their 

Ifitereoisomercs. 
To  explain  the  action  of  toxins  and  antitoxins  by  this  theory,  it  is 
assumed    that  the  toxin  mole(*nles  also  consist  of   two  parts,  one  a 
toxophorous  group,  bv  which  the  toxin  exerts  its  characteristic  action, 


I 


674  MANUAL    OF    CHEMISTRY 

the  other  a  haptophorous  group.  It  is  further  assumed  that  the  latter 
resembles  in  its  conformation  the  haptophorous  group  of  some  food 
molecule  sufficiently  to  permit  of  union  with  some  of  the  receptors  of 
cell  molecules  of  a  susceptible  animal,  and  that  by  this  means  the  toxin 
molecule  may  become  attached  to  the  cell,  and  by  its  toxophorous 
group  exert  its  destructive  influence  upon  the  central  molecules  of  the 
cell.  As  certain  animals  are  naturally  immune  to  certain  toxins,  it  is 
inferred  that  in  them  no  such  correlation  between  haptophorous  groups 
of  cell  and  toxin  exists.  If  the  toxin  injected  into  a  susceptible  animal 
be  virulent,  it  is  so  because  a  great  number  of  toxin  molecules  become 
so  attached  to  the  cells  upon  which  they  act,  and  the  animal  dies.  Bot 
with  a  less  degree  of  virulence,  although  the  death  of  the  individual 
does  not  result,  the  nutrition  of  the  affected  cells  is  seriously  im- 
paired, not  only  by  the  specific  action  of  the  toxin,  but  also  because 
the  toxin  molecules  occupy  a  sufficient  number  of  those  receptors 
of  the  cell  which  are  affinitive  to  a  given  kind  of  food  molecule  to 
cause  what  might  be  called  starvation  of  the  cell  in  regard  to  that 
nutrient  material.  The  receptors  occupied  by  toxins  have  become 
useless,  and  are  thrown  off  by  the  cell,  which,  being  capable  of  regen- 
eration of  its  parts,  seeks  to  supply  the  loss  by  the  formation  of  new 
receptors  of  the  same  kind,  and,  as  is  well  known,  in  all  such  processes 
of  repair  there  is  not  only  production  but  overproduction.  Tlie  excess 
of  receptors  so  produced  are  then  thrown  off  by  the  cell,  and,  being 
contained  in  the  plasma,  constitute  the  antitoxins,  the  free  I'eceptors 
blocking  the  haptophorous  groups  of  the  toxin  molecules,  and  thos 
preventing  their  attachment  to  the  cells,  as  the  blocking  of  the 
hydroxyl  of  morphin  prevents  its  action. 

The  serum  from  an  actively  immunized  animal  confers  temporary 
passive  immunity  upon  an  animal  into  whose  circulation  it  is  injected, 
because  free  receptors  are  thus  supplied.  Such  immunity  is  not  pro- 
duced unless  the  immune  serum  is  injected  before  the  toxins  have 
become  attached  to  the  cells,  and  its  degree  is  dependent  upon  the 
number  of  free  receptors  thus  supplied  by  the  immune  serum. 

The  theory  also  assumes  that  there  are  more  than  one  type,  or 
order,  of  side  chains,  capable  of  anchoring  food  molecules,  those  of 
the  first  order,  referred  to  above,  being  the  simplest.  The  receptors 
of  the  second  order  not  only  fix  the  food  molecules,  but  also  exert  a 
certain  degree  of  preparatory,  or  digestive,  action  upon  them.  They 
ai*e  assumed  to  have,  besides  a  haptophorous  group,  a  zymophorous, 
or  toxophore  group,  which  produces  an  enzyme-like  material,  which 
acts  upon  the  food  molecule  after  it  has  become  fixed  by  the  hapto- 
phorous group.  Receptors  of  this  order  also  fix  foreign  cells,  bacterial 
or  corpuscular,  which  they  destroy,  and  when  they  do  so  are  thrown 
off  from  the  cell,   when  repair  and    hyperplasia  occur,  and  the  free 


PHYSICO-CHEMICAL   EXAMINATION   OF   Bl 


675 


PHYSICO-CHEMICAL  EXAMINATION   OF   BLOOD. 


receptors  then  thrown  off  by  the  cell  eonstitute  the  agglutluiu^  and 
precipitiuH,  and  possibly  also  certain  lysins. 

Receptors  of  the  third  order  are  those  which  are  chiefly  efficient  in 
cytolysis.  They  possess  two  haptophoroiis  groups,  one  of  which  is 
competent  to  anchor  food  molecules  or  t'oreign  cellular  elemeuts,  the 
other  to  fix  eazynie-like  bodies  normally  existent  in  the  blood.  When 
bacteria  or  foreign  corpuscles  encounter  these  receptors  they  are  fixed 
by  the  appropriate  haptophores,  while  the  second  group  takes  up  the 
enzyme-like  body,  which  then  becomes  active.  Here  again  there  are 
exfoliation  of  the  occupied  receptors,  hyperplasia,  and  discharge  of 
the  excess  of  new  receptors.  These,  when  free,  constitute  the  immune 
I  bodies,  or  amboeeptoi*a,  while  the  euzyme-like  bodies  are  the  comple* 
■  ments  or  addimeuts,  the  two  together  acting  upon  foreign  cells  to 
destroy  them,  before  they  become  attached  to  the  haptophores  of  the 
<5elts.  The  union  of  cell,  amboceptor  and  complement  is  analogous  to 
the  nnion  of  two  organic  molecules  through  a  connecting  group  which 
frequently  takes  place  in  organic  syntheses,  as  in  the  numerous  con- 
densations which  are  produced  by  formic  aldehyde  by  means  of  the 
ICHagroup  (p.  301). 
The  moi'e  accurate  methods  of  blood  analysis,  including  those  for 
the  examination  of  the  blood -gases,  which  are  used  in  scientific  in- 
vestigation, are  quite  intricate,  and  demand  close  observance  of 
details  and  considerable  tnanipulutive  skill.  As  their  description 
would  require  much  space,  and  as  they  are  not  used  for  clinical  pur- 
poses, the  student  is  referred  to  more  comprehensive  treatises  for  an 
aeeoaat  of  them.  While  the  methods  of  microscopical  examination 
of  the  blood  for  clinical  purposes  have  been  greatly  perfected,  and 
have  led  to  valuable  results,  there  is  very  little  worthy  of  consider- 
alioD  in  the  way  of  chemical  methods  for  this  use.  We  have  accurate 
methods  for  determining  the  physical  qualities  of  specific  gravity, 
freezing  point,  and  electrical  conductivity,  methods  of  determiniug 
the  reaction,  which  leave  much  to  be  desired,  and  methods  of  de- 
termining the  quantity  of  haemoglobin,  some  of  w^hich  are  accurate 
but  difficult,  others  more  easily  eondueted»  but  affected  with  large 
factors  of  possible  error. 

Specific  Gravity.— (1)  Hammersckhtg* s  method,  which  depends 
upon  the  fact  that  a  drop  of  an  immiscible  liquid  will  remain  sus- 
pended in  a  liquid  whose  sp.  gr.  is  equal  to  its  own.  A  mixture  is 
made  of  chloroform,  sp.  gv.  ^^1.526  and  benzene,  sp.  gr.  =0.881*,  in 
cuch  proportions  that  the  sp.  gr.  of  the  mixture  is  about  1.05U  to 
1.055,    and  a  drop  of  the  blood  is  allowed   to  fall  into  it.     If  the 


4 


676 


MANUAL    OF    CHEMISTRY 


ion 

1 

»iDt 


blood -drop  sink  more  benzene  is  added,  if  it  float,  more  chloroform, 
until  the  blood -drop  remains  suspended.  The  sp,  gr.  of  the  mixture 
is  then  determined,  and  is  equal  to  the  sp.  gr.  of  the  blood. 

(2)  By  direct  weighing. — Capillary  tubes  are  used,  drawn  ont  at 
the  ends,  which  ai'e  about  12  em.  long,  and  have  internal  diameters 
of  1.5  mm.  in  the  middle,  and  0.75  mm.  at  the  ends.  These  are 
weighed  empty,  and  also  filled  with  water;  the  difference  being  the 
weight  of  water  which  the  tube  contains.  The  water  is  then  blown 
ont,  and  the  tube  filled  with  blood  and  again  weighed.  Subtraction 
of  the  weight  of  the  empty  tube  frnm  this  last  weight  gives  fl 
weight  of  the  blood.  The  sp.  gr,  is  ealculated,  as  usual,  by  divith'nj 
the  freight  of  the  blood  by  that  of  the  water. 

Freezing  Point  and  Electrical  Conductivity. — The  freezing  point 
of  the  defibrinated  blood  is  determined  by  the  method  described  at 
p.  68.     The  student  is  referred  to  works  upon  electro -chemistry 
deseriptious  of  the  apparatus  and  methods  used  to  determine  electriea' 
conductivity. 

Reaction. —  Determinations   of   the  degree   of   alkalinity  of  'hfl'M 
blood  must  be  made  as  soon  as  possible  after  the  sample  is  removed   ' 
from  theeirtmlation  to  avoid  as  much  as  possible  the  minus  error  due 
to  diminntion  of  alkalinity  (p.  667).     Lowy's  fnethod  is  probably  tbe 
least  open  to  objection.    A  flask  is  used  having  a  long  neck,  upon 
which  are  two  marks,  one  at  45  cc,  the  other  at  50  cc.    This  la 
filled   to  the  45  cc.  mark  with  a  one -fourth   per  cent,  solution  of 
ammonium  oxalate,  and  5  cc.  of  blood  are  drawn  directly  from  the 
blood-vessel  into  it  to  the  50  cc.  mark,  and  the  contents  mixed. 
The  liquid   is   then    titrated   with  a  N/25  solution   of   tartaric  acid 
<3  gm,  tartaric  acid  to  the  litre)  ^  using  a  lacmoid  paper  satumted 
with  stmng  magnesium  sulfate  solution  as  an  indicator.     One  ec  of       j 
this  solution  is  equivalent   to  0.0016  gm.  of  NaHO;    therefore  the 
number  of  cc.  used,  multiplied  by  200,  gives  the  alkalinity  in  pfl^t^ 
p/m  of  NaHO. 

Haemoglobin. — Of  the  chemical  methods  of  determination  of  tlie 
quantity  of  hemoglobin  the  best  consists  in  incinerating  the  drie^ 
blood  and  determining  the  quantity  of  iron,  from  which  the  propor- 
tion of  haemoglobin  is  calculated. 

Of  the  optical  methods  the  most  accurate  is  probably  the  spectro- 
photometric  method  of  Vierordt,  or  one  of  its  moditications,  wlm'h 
depends  upon  measurement  of  the  proportion  of  light  of  a  certaiu 
wave* length  absorbed  in  passing  through  a  layer  of  a  definite  thick* 
ness  of  the  bloody  diluted  in  known  proportion.  This  method, 
besides  yielding  accurate  results,  has  the  advantage  that  by  it  the 
proportions  of  oxyhtemoglobin,  reduced  hemoglobin  and  carbo'' 
mouoxid   haemoglobin   may  be  determined   in   the  same  sample.    H 


I 

i 


CHANGES    IN    COMPOSITION    OF    THE    BLOOD  G77 

requires,  however,  a  spectroscope  specially  adapted  to  the  purpose* 

t(See  Neubauer  and  Vogel,  Haruanalyse,  10th  ed.  pp.  680-696.) 
Colorometric  tnetliods  depend  upon  comparison  of  depth  of  color 
of  the  specimen  of  unknown  content  with  standards  of  known  con- 
tent or  valne.     When  such  comparisons  are  made  between  layers  of 

■  equal  thickness  of  solutions  equal  in  transparency  of  the  same  sub- 
stance, very  slight  differences  in  shade  may  be  easily  distinguished, 
and  accurate  results  may  be  obtained.  These  conditions  are  fulfilled 
in  the  haematinometer  of  Hoppe-Seyler  and  its  modifications,  iu 
which  the  depth  of  color  of  the  blood,  diluted  in  known  proportion, 
is  imitated  in  the  comparison  apparatus,  with  a  solution  of  pure, 
crj'stallized  haemoglobin  of  known  strength.  When  the  two  samples 
have  precisely  the  same  shade,  the  proportion  of  hemoglobin  in  the 
comparison  sample  of  known  content  will  equal  that  in  the  diluted 
blood.  To  avoid  the  inconvenience  of  preparing  the  hieemoglobin 
solution,  which  does  not  keep,  a  solution  of  carbon  monoxid  ha^nio- 

■  globin  of  known  content,  which  is  permanent,  may  be  used,  if  the 

■  precaution  be  taken  of   converting   the   heemoglobin    in   the  blood 
W  sample  into  carbon  monoxid  haemoglobin  by  passing  CO  through  it 

before  making  the  comparison. 

The  different  forms  of  clinical  colorimeters,  known  as  heemo- 
globinometcrs,  such  as  Fleishrs,  Dare's,  Oliver *s,  Taylor's  and 
Gower's»  are  all  open  to  the  objection  that  the  comparison  of  tint  is 
made  with  colored  glasses,  or  with  solutions  of  colored  substances 
other  than  the  blood -coloring  matter,  and  consequently  not  identical 
in  quality  with  it.  While  these  instrnnients  and  to  a  less  degree,  the 
forms  of  clinical  blood  *  testers  depending  upon  determinations  of 
opacity  or  of  specific  gravity,  may  afford  comparative  results  of  value 
to  the  clinician »  they  are  not  to  be  depended  upon  for  accurate  work. 
For  the  technique  of  clinical  blood  examination  the  student  is  referred 
to  the  excellent  article  by  Dr,  Camac  in  Wood's  Handb.  of  the  Med. 
Sc.  2d  Ed.  IL  37-71. 


r 


CHANGES    IN    COMPOSITION    OF    THE    BLOOD    IN    DIPPEBENT    PARTS  OP 

THE   CIRCULATION. 

As  the  blood -circulation  is  the  channel  through  which  the  mate- 
rials for  the  nutrition  and  functioning  of  the  different  parts  of  the 
body  are  carried  to  them,  and  by  which  the  waste  products  of  their 
activity  are  removed,  a  study  of  the  variations  in  the  composition  of 
the  circulating  medium  in  its  passage  through  different  organs  under 
varying  conditions  may  well  be  expected  to  throw  light  upon  the 
nature  of  normal  and  pathological  chemical  processes.  Unfor- 
tunately', the  difflcuUiee  in  the  way  of  experimentation  are  great,  and 


C73  MANUAL    OP    CHEMISTRY 

I):it  little  has  yet  been  accomplished;  the  chief  impediment  being  the 
difficulty  of  obtaining  specimens  of  blood  from  the  two  sides  of  the 
organ  under  investigation,  which  are  comparable  with  each  other. 
The  abstraction  of  any  notable  quantity  of  blood  from  the  circulation 
at  a  given  point,  or  the  ligation  of  an  efferent  vessel  and  the  con- 
sequent stasis  in  the  organ  at  once  produce  pathological  conditions. 
These  difficulties  have  been  in  part  overcome  by  "perfusion"  exper- 
iments, in  which  the  defibrinated  blood  of  a  recently  exsanguinated 
animal  is  caused  artificially  to  circulate  through  a  given  isolated 
organ,  the  liver  for  example,  maintained  at  the  body  temperature. 
Analytical  methods  are  then  applied  to  samples  of  the  unperfused  and 
perfused  blood,  suitable  for  the  determination  of  those  constitaents 
which  are  the  subject  of  the  enquiry. 

The  situations  which  have  been  the  most  frequently  under  investi- 
gation with  regard  to  blood  changes  in  them  are  the  hepatic,  the 
pulmonary  and  the  renal  circulations,  and  that  in  muscular  tissne. 
Changes  in  the  blood  in  the  kidneys  may  be  inferred  from  the  com- 
position of  the  urine,  and  will  be  considered  under  that  head.  The 
chemistry  of  the  blood  changes  in  the  lungs  is  a  portion  of  that  of 
respiration  (see  pp.  686-692). 

CHANGES   IN   THE   LTVER. 

We  have  seen  that  the  secretion  of  the  liver,  the  bile,  plays  but  a 
secondary  part  in  the  processes  of  digestion,  and  is  mainly  excremen- 
titious  in  character.  On  the  other  hand,  as  all  the  products  of  diges- 
tion which  are  absorl^ed  from  the  alimentary  canal  by  the  blood  are 
carried  by  the  portal  vein  to  the  liver,  mixed  with  the  venous  blood 
from  the  spleen  and  pancreas,  and,  after  passage  through  the  hepatic 
circulation,  are  discharged  into  the  general  circulation  by  the  hepatic 
veins,  and  as,  moreover,  the  liver  is  furnished  with  blood  for  its  own 
nutrition  by  a  separate  supply  through  the  hepatic  artery,  it  would 
seem,  a  priori,  that  the  liver  should  act  as  an  adjunct  to  the  digestive 
apparatus  in  being  the  seat  of  further  chemical  changes  in  the  prod 
n(»ts  of  digestion,  preparatory  to  their  utilization  in  the  tissues.  That 
foreign  substances  absorbed  from  the  intestine  are  modified  chemically 
in  their  passage  through  the  liver  is  shown  by  the  fact  that  many 
poisons,  not  only  metallic  poisons,  such  as  arsenic,  copper  and  lead, 
but  ;ilso  alkaloidal  poisons,  such  as  morphin,  strychnin,  atropin, 
ete.,  when  injected  into  the  portal  vein,  act  with  only  one -half  to  one- 
tliird  the  intensity  as  when  injected  in  like  amount  into  the  jugular 
vein.  The  putrid  products  of  intestinal  origin  are  also  modified  in 
the  liver.  The  normal  portal  blood  of  the  dog  has  double  the  toxic 
power  of  the  blood  of  the  hepatic  veins  of  the  same  animal  when  in- 


CHANGES    IN    THE    LIVEB 


679 


jected  into  the  periplieral  ciiv^uluLicm  uf  rabbits.  The  liver  lias  also 
beea  shown  to  be  the  situation  iu  which  some  of  the  most  important 
syntheses  which  occur  in  the  economy  take  plaee. 

In  considering  the  blood  changes  which  take  place  in  the  liver  it 
is  proper  to  consider  briefly  the 

Chemistry  of  the  Liver  Cells, —  The  proteins  which  have  been 
obtained  from  hepatic  tissues  freed  from  blood  and  bile^  are:  an 
albumin,  coagulating  at  45° ;  a  globulin,  coagulating  at  75°;  a  nucleo- 
albumin,  coagulatiog  at  70°;  a  protein  related  to  the  coagulated  pro- 
teins, insoluble  in  dilute  acids  or  alkalies  at  room  temperature,  but 
solubk*  as  albuminate  when  heated  with  alkalies,  and  at  least  two, 
probably  more,  proteins  containing  iron.  Of  these  last,  one  is  appar* 
ently  an  albumin,  others  are  certainly  uucleoproteids,  one  of  ivhich, 
containing  1.45  per  ceut  of  phosphorus,  is  split  by  boiling  water  with 
fonnation  of  a  oucleoproteid  richer  in  nucleic  acid,  which  is  precipi- 
table  by  acids,  and  yields  a  pentose,  1- xylose,  and  xantliiu  bases  on 
further  decomposition.  The  occurrence  of  these  iron -containing  pro- 
teins in  the  liver  cells,  in  which  they  exist  iu  foetal  life  in  hirger  pro- 
portion even  than  in  adult  lift%  is  of  interest  in  connection  with  the 
excess  of  iron  left  on  decomposition  of  blood  pigment  in  the  liver,  not 
accounted  for  in  the  bile  and  in  the  biliary  pigment  (p.  641),  and 
with  the  formation  of  hfemoglobiii.  Iron,  even  in  tJie  form  of  salts  of 
the  raetal,  but  better  in  that  of  organic  combination,  is  absorbed, 
increasing  in  amount  iu  the  liver,  even  if  administered  hypodermically* 
But,  as  the  iron  of  inorganic  compounds  is  apparently  not  capable  of 
elaboration  directly  into  lia^moglobiu,  these  ferruginous  proteins  are 
probably  intermediate  products,  from  which  the  blood  pigment  may 
be  formed,  either  iu  the  liver  or  elsewhere.  Similar  iron -containing 
proteins  exist  it*  the  spleen. 

The  carbohydrates  4jf  the  liver  are  glycogen  and  glucose.  Glycogen 
IB  a  substance  clogely  related  chemically  to  stai^h  (p.  321),  which 
exists  in  many  situations  in  the  body,  notably  in  the  liver,  in  muscu- 
iar  tissue,  and  in  em br ionic  tissues,  iu  each  of  which  it  is  formed 
independently.  The  quantity  of  glycogen  in  liver  tissue  is  influenced 
by  several  conditions.  The  average  proportion  is  12  to  40  p/m.  With 
a  diet  rich  in  carbohydrates  it  may  rise  as  high  as  120  to  160  p/m. 
Under  these  conditions  the  glycogen  content  increases  gradually, 
reaching  its  maximum  in  about  14  to  16  hours  after  the  meal.  With 
violent  muscular  activity  it  disappears  entirely  from  the  liver  first, 
and  subsequently  from  the  muscles  also,  and  that  more  rapidly  in 
animals  of  small  size  than  in  larger  ones.  In  rabbits  under  the  influ- 
ence of  doses  of  strychnin  sufficient  to  cause  tetanic  spasms,  hut 
insufficient  to  cause  death,  the  liver  glycogen  disappears  in  3  to  B 
hours.    The  quantity  of  glycogen  in  the  liver  is  also  diminished,  with 


MANUAL    OP    CHEMISTRY 


accompanying  glycosuria,  by  the  action  of  poisons  other  than  strj^chniu^ 
which  do  not  cause  tetamis,  such  as  arsenic,  autiiiiony  and  phosphorus. 
The  deforce  of  protective  action  of  the  liver  against  poisons,  above 
referred  to,  is  directly  proportionate  to  the  qnautity  of  glycogen  present^ 
In  fevers  the  glycogen -content  of  the  liver  is  diminished. 

The  proportion  of  glucose  in  liver  tissue  during  life  appears  to 
alvont  2  to  6  p/m.     It  rapidly  increases  in  amount  after  death  at  the 
expense  of  the  glycogen ^  and  detenu inations  of  relative  amounts  ot 
glycogen  and  glucose  must  be  made  imoiediately  after  death,  the  aetiH 
ity  of  the  diastatie  enzyme  being  arrested  by  plunging  the  organ  into' 
boiling  water  immediately  on  excision. 

The  fats  in  the  liver  exist  in  microscopic  droplets,  or  in  drops  of 
larger  size»  deposited  in  the  liver  cells,  in  the  proportion  normally  nt 
20  to  35  p/m  of  the  organ.    The  aniouiit  is  increased  after  meals  tn  fia 
araunnt  dependent  upon  the  fat -con tent  of  the  diet.     The  amount  mi 
more  greatly  increased  iu  fatty  infill  ration,  to  190  to  240  p/m,  when  ' 
the  proportion  of  water  is  correspondingly  diminished,  wdiile  the  amount 
of  other  solids  remains  at  about  the  uormaK    In  fatty  degeneratiuu  the  J 
proportion  of   fat  is  less  than  in  fatty  infiltration,  although  greater! 
than  normal,  80  to  90  p/m,  while  the  proportion  of  water  is  incr*eased,J 
and  that  of  solids  other  than  fat  is  notably  diminished.    Lecithins  are 
present  in  liver  tissue  in  the  proportion  of  about  23  p/ra. 

The  extractives  include  xanthiu  bases,  in  the  proportion  of  43^ 
p/m  of  dried  tissue,  urea,  uric  acid,  cystin,  leucin,  tyrosin,  inosite, 
and  paralactic  acid. 

The  blood  changes  which  occur  iu  the  liver,  and  the  relations  of  ] 
that  organ  to  metabolic  processes,  may  be  considered  under  five  heads: 
(1)  Formation  of  Bile,  (2)  Modifications  of    Proteins,  (3)  Modifica- 
tions of  Fats,  (4)  Action  on  Carbohydrates,  and  (5)  Liver  SyntheseJ^. 

That  the  bile  is  produced  at  the  expense  of  the  blood  is  a  proposi- ' 
tion  which  hardly  requires  demonstration,  and  it  follows  as  a  necessary 
corollary  that  in  the  liver  the  blood  is  modified  by  subtraction  of  those  , 
substances  from  which  the  bile  constituents  are  there  elaborated.    Tbej 
formation  of  the  biliary  salts  is  one  of  the  synthetic  processes  of  tb»J 
liver.     Their  amido  acid  components,  glycocoU  and  taorin,  are  pro<b 
ucts  of  general  nitrogenous  metabolism,  the  latter  deriving  from  tie 
cystin  complex.     Of  the  origin  of  cholic  acid  nothing  is  known  with 
certainty,  but  from  what  little  is  known  of  the  constitution  of  this 
acid  it  would  appear  that  a  carbohydrate  origin  is  probable,  and  po8-  I 
sibly  there  exists  some  relation   between  its  formation  and   that  of 
cholesterol  (p,  642).    The  bile  pigments,  on  the  other  hand,  originate  , 
by  an  nnalytic  process,  the  decomposition  of  the  blood  pigments  (p.  I 
640).     Cholesterol  is  met  with  in  all  cells,  either  free  or  in  combine* 
tiou»  frequently  in  its  esters,  and  is  particularly  abundant  in  the  white  j 


4 


CHANGES    IN    THE    LIVEE 


681 


substance  of  brain  tissue,  of  which  it  constitutes  about  one  ciuurter  of 
the  total  solids.  Whether  it  is  an  essential  constituent  of  the  cells  or 
a  catabolie  product  is  undetermined,  but  in  any  e%'ent  it  is  apparently 
separated  from  the  blood  as  the  latter  iu  the  liver. 

Little  or  nothing:  is  known  of  the  nature  of  the  processes  to  which 
the  fat8  are  subjected  in  the  liver,  or  of  the  products  of  such  actions 
if  any  occnr. 

Of  the  actions  of  the  liver  upon  the  products  of  protein  digestion 
there  is  likewise  but  little  known,  beyond  the  fact  that  dogs  soon  die 
with  toxic  symptoms,  which  have  been  ascribed  to  the  aetion  of 
ammonium  carbamate,  when  fed  upon  meat  after  the  estabUshment  of 
Eck's  fistula,  by  which  the  portal  blood  is  discharged  directly  into  the 
vena  cava.  The  liver  proteins  are  themselves  cjuite  readily  decomposed 
by  aseptic  autolytic  digestion,  with  formation  uf  products  similar  to 
those  produced  by  hydrolysis  of  proteins  by  acids.  The  proteins  may 
also  undergo  a  decomposition  iii  tlie  liver,  the  nature  of  which  is 
unknown,  except  that  the  formation  of  glycogen  is  one  of  its  results 
(below). 

The  action  of  the  liver  upon  the  carbohydrates  has  been  the  subject 
of  more  extended  investigation,  but,  altliough  the  glycogenic  function 
of  that  organ  is  well  established,  there  still  remains  mucli  that  is 
uncertain  regarding  hepatic  action  in  carbohydrate  metaboUsra. 

The  products  of  digestion  of  carbohydrates  brought  to  the  liver  by 
the  portal  blood  consist  of  glucose,  fructose,  galactose  and  maltose. 
Saccharose  and  lactose  when  injected  into  the  circulation  are  eliunnated 
in  their  own  form,  but  maltose  is  inverted  in  the  blood  to  glucose. 
The  three  monosaccharids  are  therefore  the  raw  materials  with  which 
the  liver  has  to  deal,  and  it  is  from  ihem  chiefly  that  glycogen  is  pro* 
duced.  The  conversion  of  these  liexoses  into  glycogen  is  a  simple 
enough  process  from  a  chemical  point  of  view:  uC^HviOb — hH20= 
nCeHiciOs,  but  by  what  mechanism  it  is  brought  about  iu  the  liver  cells 
is  ncit  known.  It  is  certain  also  that  not  all  of  the  sugar  coming  to  the 
liver  is  converted  into  glycogen.  A  portion  passes  through  the  organ 
into  the  general  circulation.  The  facts  that  fructose  is  converted  into 
glycogen,  and  that  this  on  hydrolysis  yields  only  glucose  show  that 
the  liver  has  the  power  of  converting  the  CH2OH.CO — into  theCHO.- 
CHOH —  grouping,  an  action  which  is  not  peculiar  to  the  liver  cells, 
hut  is  also  produced  by  yeast  and  by  chlorophyll.  Nor  is  the  power 
of  glycogen  formation  peculiar  to  the  liver,  it  is  also  exerted  by  mus- 
cular tissue  and  by  embrionic  tissues,  and,  indeed,  appears  to  be 
possessed  by  all  cells. 

The  question  whether  glycogen  is  produced  in  the  liver  from  carbo- 
hydrate-free proteins  has  been  the  subject  of  much  experimentation 
and  discussion,  and  cannot  be  considered  as  detarmined^  although  the 


682  MANUAL    OF    CHEMISTRY 

weight  of  evidence  appears  to  be  in  favor  of  the  affirmative.  It  has 
been  demonstrated  that  after  a  certain  period  of  starvation  glycogen 
disappears  from  the  liver,  and  that  if  animals  after  such  period  of 
starvation  be  fed  upon  fibrin,  the  presence  of  glycogen  in  the  liver 
can  be  demonstrated,  and  similar  results  are  obtained  after  feeding 
with  casein  or  gelatin,  which  contain  no  carbohydrate  component. 
In  diabetics  upon  a  carbohydrate -free  diet,  glucose  frequently  exists 
in  the  urine  in  quantities  wliich  cannot  be  accounted  for  by  the  carbo- 
hydrate-content of  either  albumins  or  glycoproteids,  but  whether  in 
these  cases  there  is  intermediate  formation  of  hepatic  glycogen  has 
not  been  shown.  No  positive  evidence  of  the  formation  of  glycogen 
from  fats  in  the  liver  is  at  hand,  although  it  is  said  to  occur  in  muscu- 
lar tissue.  It  has  also  been  sliown  that  glycerol  may  be  converted 
into  glucose  by  the  liver. 

It  has  long  been  known  that  after  death  the  proportion  of  glycogen 
in  the  liver  diminishes  and  that  of  glucose  increases,  and  that  the 
change  is  arrested  by  plunging  the  organ  into  hot  water.  From  these 
facts  it  may  be  inferred  that  glycogen  is  converted,  post-mortem,  into 
glucose  by  a  hydrolysing  enzyme  in  the  liver.  Whether  or  no  a  similar 
action  occurs  during  life  has  been  the  subject  of  much  controversy, 
the  preponderance  of  the  evidence  being  in  favor  of  the  affirmative  of 
the  question.  When  the  liver  is  more  or  less  completely  excluded 
from  the  circulation,  in  geese,  the  glucose  rapidly  disappears  from 
the  blood,  or,  at  least,  is  diminished  to  one -half  or  one -third.  If  the 
isolated  rabbit's  liver  be  perfused  with  Ringer's  solution*  notable 
quantities  of  glucose  go  into  the  solution,  proportionate  to  the  quan- 
tity o^  glycogen  present  in  the  liver,  and  being  the  greatest  at  first, 
diminishing  subsequently.  But  if  pure  water  be  used  in  the  perfusion, 
much  glycogen  goes  into  the  liquid,  but  little  glucose. 

The  part  placed  by  the  liver,  if  any,  in  the  different  forms  of 
glycosuria  (p.  744)  is  still  an  open  question,  although  it  is  certain 
that  it  is  not  the  same  in  all  the  conditions  in  which  that  symptom 
exists.  The  blood  normally  contains  0.5  to  1  p/m  of  glucose,  which 
is  also  present  in  traces  in  normal  urine  (p.  744),  but  when  the 
proportion  in  the  blood  reaches  3  p/ni  the  urine  contains  notable 
quantities  of  sugar;  glycosuria  exists.  The  power  of  the  kidneys  to 
prevent  the  passage  into  the  urine  of  more  than  traces  of  sugar  is 
therefore  limited;  and  glycosuria  may  be  caused  either  by  a  diminn- 
tion  of  this  power  below  the  normal,  or  by  an  increase  of  sugar  in  the 
blood.  The  former  condition  is  known  to  exist  only  in  a  torm  of 
artificial    diabetes,    produced    by   the    administration    of    phloridzin, 

*  A  solution  which  is  considered  as  most  suitable  to  preserve  the  life  of  the  tissues,  consisting  of 
100  cc.  of  0.75  per  cent  Nat'l  soln.;  5  cc.  of  0.25  percent  CaCla  soln.;  2.5  cc.  of  0.5  percent  NaHCOi 
Roln.:  and  0.75  cc.  of  KCl  soln. 


CHANGES   IN    TOE   LIVER 


683 


wliii^h  h  <\  gliieosid  yieldiufr  a  lipxose  oilier  than  glneose  (p,  407)  »>ii 
its  det'oiii  posit  ion,  and  causing  the  formation  in  the  system  of  glucuse 
from  protein  material.  Other  glycosurias  depend  upon  hypergly- 
kaMuia.  This  may,  in  turn,  be  due  to  one  of  three  causes,  either  (1) 
the  passage  from  tJie  alimentary  canal,  through  the  liver,  and  into 
the  general  circulation  of  an  ahiiornuilly  large  amount  of  sugar;  (2) 
the  formation  in  the  liver,  or  elsewliere  in  the  system,  of  an  increased 
quantity  of  sugar;  and,  (3)  an  inability  on  the  part  of  the  s^^stem  to 
utilize  the  amount  of  sugar  normally  produced.  The  first  cause  is 
certainly  operative  in  alimenfary  ghjcosuria,  doe  to  a  diet  inordinately 
rich  in  assirailable  carbohydrates.  It  is  probable  that,  even  under 
normal  conditions,  a  portion  of  the  sugars  of  the  portal  blood  pass 
through  the  liver  unchanged .  and  with  an  increased  richness  of  the 
portal  blood  in  carbohydrates  a  larger  proportion  will  naturally  escape 
the  retaining  action  of  the  perfectly  normal  liver.  Or  this  power  may 
be  pathologically  diminished^  as  is  probably  the  case  iu  the  milder 
forms  of  diabetes,  in  which  the  glycosuria  readily  disappears  upon  reg- 
ulation of  the  diet,  and  also  in  smne  forms  of  chronic  poisoning^  The 
Beeoiid  cause  is  operative  in  glycosuria  attending  cei*ebral  and  nervous 
lesions,  including  the  artificial  diabetes  caused  by  puncture  of  the 
floor  of  the  fourth  ventricle.  It  is  not  possible  to  exclude  this  cause 
also,  as  one  of  the  factors  in  the  severer  forms  of  true  diabetes,  in 
which  the  daily  elimination  of  sugar  may  go  as  high  as  500  to  1,000 
grams. 

There  is  also  diminution  in  the  power  of  the  system  to  consume 
the  carbohydrates  in  true  diabetes,  as  well  as  in  the  glycosuria  at- 
tending diseases  of  the  pancreas,  and  in  the  severe  artilicial  diabetes 
following  extirpation  of  that  organ.  Pancreatic  diabetes  is  developed 
in  animals  onlyafh^r  complete  extirpation  of  the  pancreas.  If  a  small 
portion  of  pancreatic  tissue  be,  at  the  time  of  the  operation,  trans- 
planted to  the  subcutaneous  tissue,  glycosuria  does  not  occur,  but  it 
does  after  removal  of  this  minute  "artificial  pancreas,'^  The  influence 
of  tlie  pancreas  in  sugar  metabolism  seems  to  be  exerted  to  aid  or  pro- 
voke muscular  glycolysis  through  the  formation  of  an  internal  secre- 
tion, an  activating  agent  of  the  same  character  as  secretin  (p.  626), 
and,  like  it,  not  an  enzyme,  as  it  is  thermostable  and  soluble  in  alcohoL 
Extract  of  muscular  tissue,  when  mixed  alone  with  glucose  solution, 
produces  only  a  slight  diminution  of  reducing  effect  of  the  sugar, 
but  on  addition  of  pancreas  extract  in  suitable  quantity,  gly- 
colysis becomes  greatly  activated»  and  the  reducing  power  dimiuishes 
rapidly. 

Liver  Syntheses, — One  synthetic  process  occurring  in  the  liver, 
the  formation  of  biliary  acids  from  their  components,  has  ah'cady 
bef*n  mentioned   (p]>,  640,  696) »  and    the  liver  exerts  its  protective 


684 


MAKUAL    OF    CHEMISTRY 


action  in  the  retention  or  neutralization  of  poisons,  in  Bome  cases  at 
least,  by  synthetic  reactions. 

Two  poisons  which  are  neutralized  in  certain  amounts  iu  the  liver 
in  this  manner  are  phenol  and  niorphin,  by  conversion  into  the  inert 
raonophenyl-  {p,  470)  and  niotiomorpliykulfates  (p.  563),  or,  more 
properly,  the  sodium  or  potassium  i^alts  of  these  acid  estei^s.  These 
are  instances  of  a  number  of  other  reactions  of  the  same,  truly  syu- 
thetic,  type:  CflH5.0H+H2S04=CoH5.0.H803+H20,  by  which  toxic 
substances  having  phenolic  hydroxy  Is,  normally  produced  iu  the  in- 
testine  by  putrefactive  processes,  are  converted  into  inert  ester  suJ- 
fates.  Thus  phenol,  eresols,  ortho*  and  paradiphenols,  indole  (indoryl) 
and  skatole  (skatoxyl)  are  normally  converted  into  the  foriu  of  the 
conjugate  compounds  iu  which  they  are  eliminated  in  the  urine.  The 
sulfates,  or  other  oxidized  sulfur  compounds,  required  to  unite  with 
tlie  phenolic  substances,  undoubtedly  have  their  origin  in  the  oxidation' 
of  the  cystin  complex  of  the  proteins,  but  to  what  extent  this  oxidation 
lakes  place  in  tbe  liver  is  uncertain.  That  it  does  occur  there,  and 
that  the  synthetic  union  takes  place  there  has  been  shown  by  perfu- 
sion experiments,  in  which  solutions  of  phenol  and  of  cyst  in  added  to 
blood  give  rise  to  the  formation  of  the  ester  sulfate  in  trave**sing  the 
liver.  A  very  similar  synthesis  also  occurs,  probably  in  the  liver,' 
between  phenolic  compounds  and  glneiirouic  acid  (p.  348),  which 
originates  indirectly  from  glucose  (p,  732) ,  the  conjugate  glucuronates 
so  formed  being  also  eliminated  by  the  urine. 

Although  it  is  doubtful  whether  uric  acid  is  formed  synthetically 
in  the  mammalia,  there  is  abundant  evidence  that  in  birds,  whose 
urine  contains  ammonium  urate  in  large  amount,  the  greater  part  of 
the  uric  acid  is  thus  produced  iu  the  liver,  from  ammonium  salts  and 
from  urea.  In  normal  geese  the  elimination  of  uric  acid  is  increased 
by  administration  of  ammonium  salt^  or  of  urea.  In  the  same  auimals, 
after  extirpation  of  the  liver,  the  elimination  of  uric  acid  is  greatly 
diminished,  and  that  of  ammonia  is  correspondingly  increased,  while 
at  the  same  time  the  nrine  contains  notable  quantities  of  lactic  acid. 
Uric  acid  has  been  produced  by  perfusing  goose  livers  with  blood  con- 
taining ammonia  and  lactic  acid.  The  elimination  of  uric  acid  by 
birds  is  increased  by  administration  of  ammonium  lactate,  of  arginin, 
and  of  mixtures  of  nrea  with  various  aliphatic  acids,  notabh-  oxy- 
and  dibasic  acids  containing  three  carbon  atoms,  such  as  lactic,  tar- 
tronie  and  malonie  acids.  In  the  formation  of  uric  acid  from  the 
dibasic  acids,  it  is  probable  that  these  are  first  converted  into  tarlronic 
acid,  which,  uniting  with  urea  forms  tartronylurea,  or  dialnric  acid 
(p.  527),  which,  in  turn,  combining  with  a  second  molec^ale  of  urea» 
forms  uric  acid,  a  synthesis,  reminding  one  of  that  by  which  uric  acid 
is  artificially  syuthetized  from  malonylurea  {p.  529).    There  ia  alfio 


4 

« 


4 
I 


4 


CHANGES    IN    THE    LIVER 


685 


eyidence  that  uric  acid  is  formed  from  ainido  acids,  glyeocoll,  leacin 
and  aspartic  acid  iti  birds.  It  is  uncertain  whether  or  not  in  this 
method  of  fonnatioo  deaniidation  of  the  ajnido  acid,  as  glyeocoll  is 
deamidatedtoglyeonicaeid:CH2NH2.COOH+H20=CH20H.COOH+ 
NHa,  is  an  intermediate  step. 

The  formation  of  urea,  which  undoubtedly  takes  place  in  the  liver, 
although  il  also  occurs  elsewliere  in  the  system,  is  frequently  referred 
to  as  a  synthesis,  although  the  reactions  involved,  being  dehydrations 
so  far  as  they  are  understood,  are  analytic,  not  synthetic,  in  character. 
The  parent  substances  from  which  urea  is  thus  produced  are  aiunui- 
niuui  curbonnt<\  :unmi>uiuin  carbanuite,  and  the  aiuido  acids. 

The  conversion  of  ammonium  carbonate  into  ui-car  0C(O-XH4)2^ 
H2N.CO.NIl2+2n:»0,  is  a  simple  dehydration,  easily  effected  m  vftro 
(p.  403).  That  a  similar  reaction  occurs  in  the  liver,  not  only  with 
the  carbonate  but  also  with  other  ammoniaeal  salts  convertible  into 
the  carbonate  by  oxidation,  has  been  demonstrated  by  perfusion  ex- 
periments, and  by  the  fact  that  in  animals  the  portal  blood  always 
yields  a  larger  amount  of  ammonia  than  does  that  of  the  hepatic  veins. 
In  the  human  subject  the  fact  that  in  atrophy  and  in  cirrbo^is  of  the 
liver  the  elimination  of  urea  is  diminished  and  that  of  ammonia  is 
increased,  is  an  indication  that  in  these  conditions  the  normal  con- 
version of  ammoaiacal  compounds  into  urea  by  the  liver  is  inter- 
rupted* 

Ammonium  carbamate  has  been  fonnd  to  be  a  constant  constituent 
of  the  blood  and  of  the  urim%  and  it  also  yields  urea  by  simple  de- 
hydration r  OCs^Q  j^jj  ^H2X,CO*NH2+H20.  It  is  also  converted  into 
urea,  by  dHhydration,  by  the  alternating  galvanic  eurrcnt,  a  prncess 
whifh  involves  alternate  oxidation  and  reduction.  That  the  forinatinn 
of  urea  from  aujmonium  carbamate  occurs  in  the  liver  has  been  dem- 
onstrated by  observations  upon  Eck  fistula  dogs  (p.  681),  which,  upon 
a  protein  diet,  exhibit  symptoms  similar  to  those  caused  by  intravenous 
injection  of  ammonium  carbamate  in  normal  animals,  and  in  which 
administration  of  the  same  substance  by  the  stomach  causes  like 
symptoms,  which  are,  however,  not  produced  in  normal  dogs  under 
these  conditions, 

Carbamic  acid  is  amido-formic  acid  (p.  411),  the  first  term  of 
series  of  mono-amido- fatty  acids.  Other  amido-a<*ids  of  the  snmr* 
aeries,  such  as  glycocoll  and  leucin,  and  of  the  succinic  series,  as 
aspartic  acid,  are  also  undoubtedly  intermediate  products  in  the 
formation  of  urea.  On  oxidation  in  alkaline  solution  these  sub- 
stances yield  carbamic  acid,  and,  on  the  other  hand,  they  are  con- 
slant  products  of  decomposition  of  albumins  by  the  action  of 
oiidizing  agents,  or  of  mineral  acids,  as  well  as  by  that  of  pro  tec- 


686  MANUAL    OF    CHEMISTRY 

lytic  enzymes  (p.  579),  but  to  what  extent  they  are  thus  formed 
in  the  system  is  undetermined.  It  cannot  be  doubted,  however, 
that  the  amido-acids  are  decomposed,  with  formation  of  urea,  prob- 
ably with  ammonium  carbamate  as  an  intermediate  product,  and 
that  such  formation  takes  place  to  a  notable  extent  in  the  liver. 
It  has  been  shown  that  glycocoU,  leucin  and  aspartic  acid,  contained 
in  arterial  blood,  which  is  made  to  traverse  the  isolated  livers  of 
dogs,  are  converted  into  urea  or  into  some  substance  closely  related 
to  it.  Another  fact  in  support  of  the  view  that  urea  is  produced 
from  leucin  in  the  liver  is  that,  while  this  amido-acid  is  not  found  in 
normal  urine,  it  makes  its  appearance  there  in  notable  quantity,  while 
the  proportion  of  urea  is  correspondingly  diminished,  in  yellow 
atrophy  and  in  acute  phosphorus  poisoning,  in  both  of  which  condi- 
tions the  function  of  that  organ  is  seriously  interfered  with. 

CHEMISTRY   OP  RESPIRATION. 

The  function  of  respiration  is  a  physico-chemical  one,  the  purpose 
of  which  is  the  introduction  of  oxygen  into  tlie  system,  and  the  re- 
moval of  carbon  dioxid  and  water  therefrom.  In  so  far  as  it  is 
chemical,  the  subject  may  be  considered  under  the  following  heads: 
(1)  changes  in  composition  of  the  air;  (2)  changes  in  composition 
of  the  blood -gases  in  the  lungs;    (3)  tissue -respiration. 

Changes  in  Air,  —  The  average  composition  of  dry  atmospheric 
air,  in  volumes,  corrected  for  0°  and  760  mm.  barometric  pressure, 
is:  Oxygen — 20.95,  nitrogen — 79.02,  carbon  dioxid — 0.03,  disregaid- 
in^  traces  of  other  gases.  The  proportion  of  carbon  dioxid  varies 
from  the  above  percentage  in  confined  spaces  (p.  355),  and  the  air 
always  contains  varying  quantities  of  vapor  of  water  (p.  150).  The 
expired  air  varies  somewhat  in  the  relative  proportions  of  its  con- 
stituents. Its  average  composition  is,  however:  oxy^t-n  — 16.03, 
nitrogen — 79.59,  carbon  dioxid — 4.38;  and  it  is  saturated  with  vapor 
of  water  at  the  temperature  of  the  body,  about  36°,  and  the  baro- 
metric pressure.  It  will  be  seen  that  the  proportion  of  nitrogen, 
wliich  is  a  mere  diluent,  remains  practically  unchanged,  and  that 
the  changes  which  the  air  undergoes  in  respiration  consist  of  the 
subtraction  of  4.92  volume -per  cent,  of  oxygen,  and  the  addition  of 
4.35  volume-per  cent,  of  carbon  dioxid  and  of  a  quantity  of  vapor  of 
water,  varying  with  the  degree  of  saturation  of  the  inspired  air. 
With  an  increased  degree  of  humidity  of  the  inspired  air  the  eUni- 
ination  of  water  by  the  skin  and  kidneys  is  increased. 

That  tlie  oxygen  taken  into  the  system  is  utilized  in  processes 
of  oxidation  which  take  place  in  the  tissues,  and  only  to  a  limited 
extent  in  the  lungs  and   bh>od,  is  now  generally  admitted.     If  the 


CHEMISTRY    OP    RESPIRATION 


G87 


oxygen  taken  in  were  entirely  nsetl  for  tlie  oxidation  of  carbon, 
Atid  if  there  were  no  sonrce  of  oxygen  other  than  the  inspired  aii\ 
the  volume  of  oxygen  removed  from  the  inspired  air  should  eqiiiil 
the  volume  of  carbon  dioxid  added  to  it,  as  one  niolpcule  of  oxygen 
produces  one  moleenie  of  carbon  dioxid.  Bnt  the  volumes  are  not 
equal,  and  neither  of  the  above  conditions  exists.  All  tissues  and 
organic  food  constituents  contain  hydrogen  as  well  as  carbon »  and 
a  portion  of  the  oxygen  is  used  to  oxidize  this  to  water.  On  the 
other  banc),  they  all  contain  oxygen »  as  well  as  carbon  and  hydrogen^ 
which  supplements  the  oxygen  derived  from  the  air.  Thus  IHU  grams 
of  glucose  produces  by  complete  oxidation  264  grams  of  carbon  dt- 
oxid,  and  108  gi*ams  of  wat^r,  for  which  288  grams  of  oxygen  are 
required,  of  which  the  glucose  itself  furnishes  96  grams»  or  one-third 
of  the  amount: 


c«H,20o 

180 


6O2 
192 


—      6C02 

204 


6H.0 
IDS 


Moreover,  carbon  dioxid  and  water  are  not  the  only  products  of 
oxidation  formed  in  the  body:  urea,  for  example,  is  a  product  of 
oxidation  of  the  proteins*  Thus  the  relation  of  oxygen  consumed 
to  carbon  dioxid  produced  depends  upon  many  conditions,  and  there 
is  always  an  apparent  loss  of  oxygen.  This  relation  is  ktiown  as 
the  respiratory  quotient,  and  is  obtained  by  dividing  the  CO2  pro- 

4  U5 

duced  by  the  O2  consumed.     Thus  in  the  above  proportions:  Acr^ 

0.88.  The  fats  contain  10.73  to  1L91%  of  oxygen,  the  proteins 
2L5  to  23.5%,  and  the  carbohydrates  51.17  to  53.33%,  while  the 
amount  of  oxygen  required  for  the  oxidation  of  their  hydrogen  is, 
for  100  parts  each:  of  fats,  97.3  to  98.8;  of  proteins,  52.0  to  58.4, 
and  of  carbohydrates,  51.17  to  53.3.  It  is  clear,  therefore,  that 
the  carbohydrates  contain  sufficient  oxygen  for  the  oxidation  of  their 
hydrogen,  while  the  proteins  and  fats  require  additional  oxygen 
for  that  purpose,  and  that,  consequently,  the  respiratory  quotient 
will  vary  with  the  composition  of  the  diet.  It  also  varies  witli  the 
amouot  of  muscular  activity,  increase  of  which  is  attended  with  in- 
crease of  oxidation  of  carbohydrates,  proteins  and  fats,  and  with 
marked  increase  of  production  of  carbon  dioxid. 

In  considering  the  method  of  intercliange  between  the  gases  of 
the  blood  and  those  of  the  air,  it  must  be  remembered  that  this 
exchange  takes  place  between  the  blood  and  the  air  contained  in 
the  alveoli,  and  that  this  is  not  completely  changed  in  respiration. 
Therefore,  the  composition  of  tlie  alvrolar  air,  which  is  the  mixture 
formed  by  diffusion  between  the  air  remaining  in  the  alveoli  after 
expiration  with  that  taken  in  during  inspiration,  is  of  importauce 
itj  connection  with  the  method  of  gas  interchange.     The  composition 


MANUAL    OF    CHEMISTRY 


JOD, 

s  eta 

t 

i 


of  alveolar  air  in  the  human  subject  ean  only  be  implied  by  calcu- 
lation; but  experiments  upon  aniraala  have  shown  it  to  contain  3.6 
to  3.8  volume-per  cent,  of  carbou  dioxid  and  about  10  volume -pec^ 
cent,  of  oxygen,  corrected  for  0°  and  760  mm.  ■ 

Gases  of  the  Blood.— The  gases  which  the  blood  gives  off  when 
it  is  brought  into  a  vacuum  consist  of  oxygen,  carbon  dioxid.  tiitro- 
gen,  and  traces  of  argon.     The  amount  of  nitrogen,  iueluding  argOD, 
is  about  the  same  in  arterial  and  venous  blood  in  different  parts 
the  circulation,  i.e.,  from  1  to  2  volumes  in  100  volumes  uf  bloi 
It  probably  takes  no   part  in  the  chemical  processes  of  the  bod, 
The   blood -gases   in  which   interest  centers  are,   therefore,   oxygi 
and  carbon  dioxid.     The  methods  of  absorption  or  elimination  of 
these  gases,  and  the  form  in  which  they  exist  in  the  blood  may  k 
either  physical  or  ehemicaL     That  is  to  say,  they  may  pass  between 
blood   and   air  by  simple   diffusion,   or  by  a   so-called  '^vitalistic"! 
process,  which,  if  it  be  not  physical,  must  be  chemical ;  and  they 
may  exist  in  the  blood  in  simple  physical  solution,  or  in  a  form  of 
chemical  combination.     To  determine  which  of  these  methods  are 
operative,  and  in  what  degree,  is  a  subject  requiring  both  physical 
and  chemical   investigation.     We  briefly  recall  here  the  laws  gov* 
erning  the  absorption  of  gases  by  liquids:  fl 

When  a  gas  is  in  contact  with  a  liquid  it  may  either  dissolve  in^ 
or  combine  chemically  with  the  liquid.  In  either  case  it  is  said  to  be 
absorbed.     If  in  physical  solution  it  is  said  to  be  dissolved,  if  in 
chemical  combination  it  is  said  to  be  combined. 

The  CO- efficient  of  absorption  of  a  gas  is  the  volume  of  that  ^s» 
reduced  to  0^  and  760  mm.  Hg,  absorbed  by  unity  volume  of  tie 
liquid  under  a  pressure  of  760  moi.;  and  it  varies  with  the  tempera- 
ture. Thus  the  coefficient  of  absorption  of  carbon  dioxid  in  wuttr 
is  1.185  at  10*^,  whieli  means  thai  1  ec.  of  water  at  that  temperature, 
will  absorb  U85  cc.  of  carbon  dioxid. 

The  weight  of  gas  which  a  given  volume  of  liquid  will  dissolvi  at 
a  given  temperature  is  dii*ectly  proportionate  to  the  pressure*  But 
as  the  volume  of  a  gas»  at  a  given  lempcratui-e,  varies  inversely  as 
the  pressure,  the  vohtme  of  gas  dissolved  is  independent  of  the  pres^ 
sure;  and  the  dmsity  of  the  dissolved  gas  is  in  constant  relation  to 
that  of  the  undissolved  gas  in  contact  with  it*  Or,  in  other  words, 
the  pressure  or  tension  of  the  dissolved  gas  is  the  same  as  that  of  the  ^ 
free  gas  in  contact  with  it.  If  this  equality  be  disturbed  from  anjr^ 
cause,  as  by  variation  of  temperature,  the  gas  passes  into  or  out  of 
solution,  from  the  higher  to  the  lower  pressure. 

The  quantity  of  gas  dissolved  diminishes  with  increase  of  tem- 
perature, as  the  elastic  force  of  the  gas  increases. 

When  several  gases  are  dissolved  in  the  same  liquid,  each  is  dis* 


CHEMISTRY    OP    RESPIRATION 


Hsolved  as  if  it  were  alone,  its  volume  beiog  estimated  at  the  pressure 
wlucli  belongs  to  that  gas  in  the  mixture.  This  partial  pressure  is 
to  the  total  pressure  as  the  volume  of  the  gas  in  questiou  is  to  that 
of  the  mixture  under  the  same  conditions.     The  partial  pressure  may 

VXP 

Kbe  calculated   by  the  formula  PP=-j^,  in  which  V  is  the  volume- 

Bper  cent*  of  the  gas  iu  question  in  the  mixture,  and  P  the  total 

■  pressure  in  mm. 

■  The  pressure  {tension)  of  a  gas  in  solution  may  be  experimentally 
■determined    by    bringing    the    solution    in    contact    with    gaseous 

mixtures  containing  known  and  varying  proportions  of  the  gas  in 
question.  If  the  pressure  in  the  solution  be  less  than  the  partial 
pressure  in  the  mixture,  gas  will  be  dissolved,  while  gas  will  be  given 
off  from  the  solution  if  the  reverse  be  the  case.  By  analyzing  the 
gaseous  mixtures,  that  one  is  found  in  which  the  gas  under  investi- 
gation has  neither  increased  nor  diminished,  and  the  partial  pressure 
of  the  gas  in  it  equals  the  pressure  of  the  gas  in  the  solution, 
m  Oxygen. —  The  proportion  of  oxygen  in  arterial  blood  is  about 
V21,6  volume -per  cent.  That  in  venous  blood  differs  in  different 
parts  of  the  venous  system.  An  average  of  many  analyses  of  the 
blood  of  the  right  heart  gives  its  oxygen -content  a&  14.85  volume - 
per  cent.  As  the  coefficient  of  absorption  of  oxygen  in  water  at 
35"^,  the  body  temperature,  is  0.0277,  the  maximum  amount  of  that 
gas  that  could  exist  in  solution  in  water  is  2.77  volume-per  cent., 
and  it  may  be  assumed  that  fur  simple  solution  the  action  of  the 
blood  plasma  h  the  same  as  that  of  water.  Indeed,  analyses  of  the 
gases  from  blood -plasma  and  blood -serum  have  shown  the  presence 
of  0.26  volume -per  cent,  of  oxygen. 

It  follows  that  almost  all  of  the  oxygen  in  the  blood  exists  in 
some  form  of  chemical  combination  in  the  blood* corpuscles;  and  we 
have  seen  that  hcemoglobin  is  capable  of  forming  such  a  combina- 
tion. It  has  also  been  shown  that  a  solution  of  freshly  prepared, 
pure,  crystallized  oxyhtBmoglobin  behaves  in  the  same  manner  as 
fresh,  defibrinated  blood  under  the  influence  of  reduced  pressures. 
The  dissociation  of  oxyhaemoglobin,  whether  in  solution  or  in 
defibrinated  blood,  under  reduced  pressures  also  shows,  by  the 
manner  in  which  it  takes  place»  that  the  oxygen  is  present  in  a 
"loose''  form  of  chemical  combination.  The  disengagement  of 
oxygen  does  not  begin  immediately  with  reduction  of  pressure, 
indeed,  this  may  be  reduced  to  about  half  an  atmosphere  without  any 
notable  disengagement  of  oxygen.  Operating  at  35*^  to  39*^,  the 
pressure  may  be  lowered  to  410  mm.  Hg  without  any  reduction  of 
the  oxygen -content  of  the  arterial  blood,  at  375  to  365  mm,,  it  is 
slightly  reduced,  at  300  mm.,  the  reduction  is  notable,  and  in  the 
vacuum  of  the  mercury  pump  the  oxygen  is  completely  given  off. 

41 


690  MANUAL    OF    CHEMISTRY 

As  to  the  process  by  which  the  oxygen  passes  from  the  alveoli 
into  the  blood:  if  the  oxygen  pressure  in  the  blood  be  less  than  the 
oxygen  partial  pressure  in  the  alveoli  the  physical  action  of  diffusion 
is  sufficient  to  transfer  the  gas  in  the  direction  of  the  lower  pressure, 
but  if  the  reverse  be  the  case  some  other  force  must  be  in  operation. 
We  have  seen  that  the  volume -per  cent,  of  oxygen  in  alveolar  air 
is  16,  which,  at  760mm.,  represents  a  partial  pressure  of  121.6mm. 
The  oxygen  pressure  in  arterial  blood  has  not  been  determined  with 
equal  certainty.  By  some  observers  this  value  is  given  as  75  to 
80  mm.,  but  others  have  obtained  results  as  high  as  110  to  144  ram. 
The  weight  of  evidence  appears  to  be  in  favor  of  the  lower  figures, 
and  of  the  consequent  view  that  the  passage  of  oxygen  from  the 
alveoli  to  the* blood  is  a  purely  physical  process. 

Carbon  Dioxid, — The  proportion  of  carbon  dioxid  in  arterial 
blood  is  30  to  40  volume-per  cent.,  usually  nearer  40.  The  pro- 
portion in  venous  blood  is  about  48  volume-per  cent.,  and  in  as- 
phyxia it  may  rise  as  high  as  69.21  volume-per  cent.  If  the  plasma 
and  corpuscles  be  separately  examined,  both  are  found  to  give  off 
carbon  dioxid,  and  that  in  the  relative  proportion  of  one -third  of 
the  entire  amount  from  the  corpuscles  and  two -thirds  from  the 
plasma.  If  blood  be  introduced  into  a  vacuum  it  bubbles  and  gives 
off  all  of  its  gas,  but  if  blood  serum  or  plasma  be  subjected  to 
the  vacuum  a  portion  of  their  carbon  dioxid  is  retained,  and  is  only 
liberated  upon  addition  of  an  acid.  Therefore,  a  part  of  the  carbon 
dioxid  of  the  blood  exists  in  the  corpuscles  in  ^M'oose"  combination, 
while  in  the  plasma  a  part  exists  in  that  condition,  or  in  solution, 
and  a  part  in  "firm"  combination;  and  the  blood  corpuscles  act  like 
the  acids,  in  that  they  liberate  this  latter  portion  from  its  combi- 
nation. Indeed  oxyhfemof^lobin  is  capable  of  expellinp:  carbon  riinxid 
from  alkaline  carbonates  in  a  va<Miuin.  Carbon  dioxid  apparently 
exists  in  the  corpuscles  in  two  forms  of  combination.  It  is  in 
part  combined  with  luuinoglobin  ((>.  059),  probably  with  its  protfiii 
component.  Another  ])ortion  enters  into  reaction  with  the  alkaline 
phospli.-ites,  which  are  present  in  snfticient  quantity  to  form  alkaline 
bicarbonates  and  monophosphates. 

The  proportion  of  carbon  dioxid  existing  in  the  plasma  in  "firm" 
combination  has  not  been  accurately  determined.  Undoubtedly  it 
represents  the  alkaline  carbonates  resulting  from  decomposition  of 
the  bicarbonates  (see  below),  but  the  quantity  of  these  cannot  be 
determined  either  from  the  quantity  of  carbonate  left  on  incineration, 
or  from  the  def]^ree  of  alkalinity  of  the  plasma,  because  the  former 
result  in  part  from  the  combustion  of  other  organic  compounds  of 
the  alkali  metals,  and  the  latter  is  due  in  part  to  the  presence  of 
other  alkaline  compounds.     Nor  can  the  amount  of  carbon  dioxid 


CHEMISTRY    OF    RESPIRATION 


cai 


wliieh  is  not  removed  by  the  vacuum,  and  only  after  addition  of  an 
icid,  be  considered  as  representiDg  the  whole  of  the  firmly  combined 
firbon  dioxid,  because  other  jsukstauces  exist  in  the  plasma,  such 
fi  the  globulins,  which  decompose  a  part  of  the  alkaline  carbooates 
n  a  vacuum.     It  can  only  be  stated  that  of  the  20  to  32  volume- per 
ent.  of  carbon  dioxid  in  the  plasma,  from  5  to  9  volume* per  cent. 
I  retained  in  a  vacuum,  and  probably  represents  a  large  part  of 
he  alkaline  carbonates  existing  in  Ihe  blood  as  bicarbonates.     Such 
1)eing  the  case,  a  notable  proportion,  at  least,  of  the  loosely  com- 
bined carbon  dioxid  must  exist  in  the  plasma  in  the  form  of  biear- 
bonates  (2NaHC(>a=Na2C03+COj+H20),  from  which  it  is  liberated 
liiii  vacuo  by  the  action  of  weakly  acid  substances,  such  as  the  glob* 
ilins.     Indeed,  the  greater  part  of  the  carbon  dioxid  iu  the  plat^ma 
probably  present  in  the   form   of  bicarbonates,  a  view  which   is 
rther  supported  by  the  notafile  diminution  in  the  amount  of  carbon 
lioxid  in  the  plasma  in  aeidism  (diminished  alkalinity  of  the  blood), 
used  either  by  administration  of   mineral   acids,  or  by  increased 
aeid   formation   in  diabetic  coma,  in  which  the  total  carbon  dioxid 
in  tlie  plasma  may  fall  as  low  as  2  to  3  volume- per  cent  ,  the  excess 
pf  acid  taking  up  the  bases. 

I  A  portion  of  the  carl>on  dioxid  of  the  plasma  is  also  in  simple 
■olution.  By  the  method  described  on  page  689  the  carbon  dioxid 
[pressure  in  arterial  blood  has  been  found  to  be  2.S%  of  an  atmos- 
jhere,  equivalent  to  a  pressure  of  21  mm.,  of  Hg,  while  in  the  blood 
a  the  right  heart  3. 81%===  28, 95mm.  Hg,  and  5.4%^ 41.04 mm.  Hg 
lave  been  found.  Comparative  results  between  the  carbon  dioxid 
iressures  in  the  blood  and  in  the  alveolar  air  are,  however,  not 
loncordant-  According  to  some  observers,  the  blood  carbon  dioxid 
►rf'ssure  is  the  higher,  and  the  exit  of  carbon  dioxid  is  consequently 
I  purely  physical  process;  while,  according  to  others,  the  alveolar 
kartial  pressure  is  the  higher,  and  a  "vitalistic**  action  of  the  epi- 
ibelial  cells  is  invoked  to  overcome  the  higher  pressure.  The  oxygen 
mtering  the  blood  is  also  supposed  to  play  a  part  in  expelling  carbon 
lioxid  from  its  cheo^ical  combinations. 

Tissue  Respiration,  or  internal  respiration,  takes  place  between 
he  blood  in  the  capillaries  and  the  tissues,  through  the  lymph,  and 
insists  in  the  passage  of  oxygen  from  the  blood  to  the  tissues,  in 
rbich  the  oxidations  of  the  body  occur,  and  the  passage  of  the  car- 
on  dioxid  and  water  resulting  from  such  oxidations  in  the  opposite 
irection.  As  oxygen  enters  into  4'ombination  in  the  tissues,  and  is 
hereby  removed  from  solution,  and  as  carbon  dioxid  is  there  pro- 
oced,  it  is  clear  that  the  oxygen  pressure  in  the  tissues  must  become 
than  that  in  the  bhxid,  while  the  carbon  dioxid  pressure  in  the 
ts    must   tend    to    increase,  and    therefore    the  simple    physical 


692 


MANUAL    OF    CHEMISTRY 


process  of  passage  from  the  greater  to  the  lesser  pressure  must  be  in 
operation . 

LYMPH— CHYLE— TRANSUDATES— EXUDATES 


J 


The  lymph  is  a  eirculatiiig  luediuui  intermeditite  betweeu  the 
ami  the  cells.    The  eiiduthulial  eelk  of  the  heart  and  blood- vessels  and 
those  of  the  splenic  pulp  ai-e  the  only  ones  in  the  body  which  coi 
into   immediate  contact  with   the    blood;    all  other  cells  derive  thi 
materials  for  their  nutrition,  ioL-luding  oxygen,  from,  and  dischari 
their  eatabolie  products  into  the  lym])h,  between  which  and  the  bl< 
a  corresponding  iuterchauge  takes  place.    The  lymph  circulation  diffei 
from  that  of   the  blood  principally  in  that    the  flow  is  only  in  oQI 
direction,  from  the  smaller  to  the  larger  vessels.    The  lynipli  is  forriii 
by  filtration  and  osmotic  pressure  frinn  the  blood  plasma  iu  the  eapil 
laries  into  the  lymph  spaces,  the  smallest,  blind  ramitications  of  tl 
lymphatic  system,  and,  having  performed  its  function  in  the  iutei 
chauge  of  material  with  the  cells,  finds  its  way  back  to  the  venoi 
system,  after  having  passed  through  gland-like  enlargeiueuts,  ealli 
the  lymphatic  ghmds,  or  lymphatic  nodes,  principally  liy  way  of  the 
thoracic  duct  and  the  right  common  lymphatit^  trunk.    Only  a  portioa 
of  the  eatabolie  products  collected   by  the  lymph  is  carried  to  thlM 
venous  system  by  the  larger  lymphatic  trunks,  the  greater  part  passin?^ 
directly  from  the  smaller  lymphatics  into  tlie  capillaries  and  venul<s 

Distinction  is  made  between  four  varieties  of  lymph:    (1)  TiV.< 
lymph,  that  contained  in  the  intercellular  spaces  throughout  the  body; 
(2)  Clrcuiafhig  itfniph,  that  passiiig  slowly  thnmgh  the  lymphatic  vei 
sels  towards  the  veins;     (3)    Chyle,  the  circulating  lymph  collet'ft'a 
from  the  intestinal  mucous  membrane  during  digestion,  particularly 
of   fats;     (4)   Serous  lymph,  the  liquids  normally  contained  in  t 
pleural,  peritoneal  and  pericardial  cavities,  in  the  cerebral  ventricles, 
and  the  cerebro- spinal  fin  id. 

The  physical  properties  and  composition  of  the  tissue,  eirealatinj 
and  serous  lymphs  are  essentially  identical.    The  lymph  contains  co^ 
puseles,  a  few  red  blood -corpuscles  and  many  leucocytes,  which  hitt 
are  formed  iu  the  lymphatic  glands,  in  the  spleen  and  in  the  tbyniii^.^ 
The  fluid  portion  of  the  lymph,  the  lymph  plasma,  is,  like  the  bM 
plasma  from  which  it  is  derived^  clear,  faintly  yellow*  alkalin<i  from 
the  presence  of  XasCOa  and  Na^HPO^,  salty  in  taste  from  the  presem 
of  about  0.6  p/m  of  NaCl,  of  specific  gravity  slightly  lower  thau  th«< 
of  blood  plasma,  because  of  less  content  of  solids,  aud  coagulable  froffl 
the  presence  of  fibrinogen  aud  fibrin  ferment.    Serous  lymph,  however, 
although  containing  fibrinogen,  contains  no  fibrin  ferment,  aud  thei 
fore  does  not  coagnlate  spontaneously.     Serous  lymph  also  contaii 
less  protein  than  tissue  or  circulating  lymph.     The  constituents 


m 

■rein 
irly I 


LYMPH  —  CHYLE  —  TRANSUDATES  —  EXUDATES 


693 


"plasma  are  the  same  in  kind  as  thnse  us  tlie  blood   jitasina, 
fiitratltatively  the  proportion  of  ^^olids,  35.7-57.2  p/m,  aud  notably 
|of  proteins,  37.5  p/m,  are  less  than  those  in  blood  plasma. 

The  chyle  is  the  lymph  produced  iu  the  la(^teala  of  the  intestinal 
•mucosa  during  digestion  of  fats.  Practically  all  of  the  fat  is  absorbed 
%y  this  channel.  The  chyle  is  milky  iu  appearance  from  the  presence 
of  oil  gh^bules  in  suspension^  and  it  differs  from  the  clear  lymph  which 
jis  carried  by  the  same  vessels  when  fat  absorption  is  not  taking  plar-e, 
fiolely  in  the  presence  of  notable  quantities  of  fat.  The  maximnm 
amount  of  fat  found  in  the  chyle  obtained  from  a  fistula  in  the  human 
(Bnbjeet  during  fat  absori>tion  was  47  p/m,  the  fiuid  from  the  same  fis- 
!tuU  daring  fasting  containing  0.6  to  2.6  p/m  of  fat.  ^* 

Transudates  and  Exudates. — Speaking  strictly,  the  lyraph  is  a 
sudate,  being  formed  b}*  filtration  and  osmosis  from  the  blood»  but 
e  appHeatiou  of  the  term  has  come  to  be  limited  to  pathologically 
increased  deposits  of  more  or  less  modified  serous  lymph  in  the  lymph 
aces  or  cavities,  produced  by  increased  blood  pressure,  by  patholog- 
ical modification  of  the  walls  of  the  vessels,  or  by  alterations  in  the 
blood,  but  not  by  intlammatory  processes.  The  typical  transudate  is 
that  of  oedema,  whether  of  ascites,  anasarca »  iiydrothorax,  hydrocele, 
i&tc.  The  fluid  of  oedema  is  colorless  or  pale* yellowish,  or,  with 
tteudant  icterus,  yellow  or  brown,  alkaline,  containing  very  few 
loeytes  or  red  cells,  and  sometimes  flakes  of  flhrin,  of  low  sp.  gr., 
exceeding  1010,  and  containing  a  low  proportion  of  proteins,  1.5 
SO  p/m. 

Sometimes  a  transudate  may  be  milky  in  appearance,  and  may  con- 
tain from  4  to  43  p/m  of  fat^  suspended  in  fine  oil  globules,  from 
admixture  of  chyle.  The  transudate  of  hydrocele  differs  from  the 
typi(»al  transudate  in  being  more  highly  colored,  in  having  a  higher 
8p,  gr. ,  1016  to  1026.  iu  containing  a  larger  proportion  of  solids,  to 
60  p/m,  and  of  proteins,  to  50  p/m,  and  frequently  in  containing  a 
large  amount  of  cholesterin,  suspended  in  glistening,  tabular  crystals, 
Tbe  fluid  of  ovarian  cysts  contains  metalbumin  and  paralbumin  (p. 
594). 

Exudates  differ  from  transudates  in  being  the  products  of  inflam- 
matory processes,  in  being  cloudy  or  opaque  from  the  presence  of  a 
much  greater  number  of  leucocytes  and  other  itmrphological  elements, 
in  being  yellow,  dirty- greenish,  or  reddish  in  color,  in  being  of  higher 
p.  gr.,  1016  to  1030,  in  containing  a  larger  proportion  of  solids,  to 
90  p/m,  and  of  proteins,  to  60  p/m,  and  in  being  spontaneously 
eoagulable. 

Pus  is  an  exudate  modified  by  proteolytic  bacterial  action.  It  is 
creamy  and  mucoid  in  consistency,  usually  alkaline,  although  some- 
tiroes  acid  and    having  the  odor  of  butyric  acid»  usually  of  sp.  gr. 


i 


694  MANUAL    OF    CHEMISTRY 

about  1030,  but  varying  from  1020  to  1040.  It  consists  of  two  parts, 
whose  relative  proportions  vary  within  wide  limits.  A  liquid  portion, 
the  liquor  puris,  or  pus  serum,  somewhat  resembling  the  blood  serum 
in  appearance  and  in  composition.  It  contains  no  fibrinogen,  and 
does  not  coagulate  spontaneously.  It  contains  a  nueleoalbumin  or 
nuceloproteid,  which  is  precipitated  by  acetic  acid,  and  is  very  dif8- 
cultly  soluble  in  excess  of  the  acid. 

The  pus  cells  are  modified  leucocytes,  containing  a  large  proportion 
of  protein,  particularly  of  nucleoproteids  and  nucleins.  Among  the 
former  the  most  abundant  is  the  "hyaline  substance  of  Rovida,"  which 
swells  to  a  slimy  mass  with  a  10  per  cent  solution  of  NaCl.  They 
contain  no  nucleohiston,  or  histon,  and  no  thrombin  or  prothrombin. 
They  contain  a  proteolytic  enzyme  and  the  products  of  its  action, 
albumoses,  peptone,  and  xanthin  bases,  and,  in  the  pus  of  abscesses 
of  long  standing,  leucin  and  tyroein.  They  also  contain  notable 
amounts  of  cholesterol,  lecithins,  cerebrin,  as  well  as  fats,  soaps,  and 
free  fatty  acids. 

URINE. 

The  urine  is  the  only  pure  excretion  of  the  body,  its  formation 
has  but  one  object,  the  removal  of  waste  material,  and  it  is  the  prin- 
cipal channel  of  exit  from  the  body  of  water,  of  solid  products  of  dis- 
assimilation,  and  of  foreign  substances,  medicines,  poisons,  etc.,  more 
or  less  altered  by  chemical  change  in  the  body.  As  the  urine  is 
obtainable  without  difficulty,  and  as  it  varies  in  composition  with 
variations  in  the  chemical  processes  of  the  body,  analysis  of  the  urine 
affords  the  readiest  means  of  obtaining  insight  into  the  nature  of 
normal  chemical  processes  in  the  body,  and  of  pathological  departures 
therefrom.  The  form  in  which  medicinal  substances  are  eliminated 
in  the  urine  is  also  of  interest  to  the  pharmacologist,  as  indicating 
the  changes  which  they  have  undergone  in  their  passage  through  the 
system,  and  their  probable  method  of  action.  The  toxicologist  finds 
in  the  urine  the  last  traces  of  poison  undergoing  elimination. 


PHYSICAL    CHARACTERS. 

Consistency. — The  normal  urine  of  man  and  of  the  eamivora  is 
clear  and  transparent  when  voided.  On  standing  it  usually  soon  be- 
comes cloudy,  and  a  light  flocculent  cloud  of  "mucus,"  the  "nubecula" 
of  older  authors,  which  contains  epithelium,  mucus  corpuscles,  and 
urates,  separates  and  remains  suspended  in  the  liquid.  The  urine  of 
the  berbivora  is  cloudy  when  voided  and  is  alkaline  in  reaction,  and 
human  urine  when  alkaline  in  reaction  is  also  cloudy.     When  the 


UBINE 


605 


urine  is  not  perfectly  transparent  its  cloudiness  may  be  due  to  the 
presence  of  morphological  elements  and  casts  in  suspension,  or  to  the 
presence  of  phosphates  or  urates  which  have  become  insoluble* 
Phosphates  thus  separate  from  the  urine  when  the  reaction  becomes 
gnbacid,  and  they  disappear  on  addition  of  an  acid.  Urates  are  de- 
posited from  hyperacid  urines  and  ilo  not  dissolve  on  addition  of  nt'id 
to  the  urijie.  Generally  the  urine  has  no  viscidity,  but  alkaline  urines 
ijontaiuing:  pns  are  sometimes  thick  and  ^'stringy**'  Wlieu  shaken 
with  air,  the  bubbles  soon  disappear  from  the  surface  of  normal  urine, 
but  in  urines  contain ingr  sugar  or  bile  the  froth  persists  for  quite  a 
time.  In  the  rare  condition  of  chyluria»  depending  upon  the  presence 
of  filaria  in  the  blood,  the  urine  is  turbid  and  has  the  appearance 
of  milk. 

Quantity. — The  average  normal  quantity  of  urine  passed  by  an 
adult  in  24  hours  is  1,200  to  1,500  ec,  being  somewhat  less  in  the 
female  than  in  the  male;  and  in  children  absolutely  less,  but  rela- 
tively to  weight  more  than  in  adults.  Tlie  quantity  is  increased  with 
increase  of  the  amount  of  liquids  ingested,  and  diminished  when  the 
secretion  of  perspiration  is  increased.  Polyuria,  i*  e.,  increased 
quantity  of  urine,  occurs  pathologically  in  diabetes  mellitns,  in  which 
it  is  frequently  3,000  to  5,(X)0  cc,  sometimes  10,000  to  25,000  cc, 
and  even  more,  in  diabetes  insipidus,  during  absorption  of  large  effu- 
fiions,  in  granular  atrophy  of  tlie  kidneys,  and  in  nervous  diseases, 
such  as  hysteria,  chorea,  and  epilepsy-.  Oliguria,  i.  e.,  dijninished 
quantity  of  urine,  occurs  in  continued  fevers,  in  acute  nephritis^  in 
chronic  parenchymatous  nephritis,  in  cardiac  diseases,  towards  the 
fatal  termination  of  all  diseases,  in  surgical  shock,,  and  under  all 
conditions  iu  which  water  is  otherwise  disposed  of,  as  in  diarrlitea, 
after  hiBmorrhages,  and  during  formation  of  dropsical  effusions. 

Specific  Gravity,  ^- The  specific  gravity  of  the  mixed  urine  of 
24  hours,  when  the  anmnnt  is  normal,  is  1,015  to  1,025.  The 
"corrected"  specific  gravity  is  the  observed  sp.  gr.,  corrected  to 
what  it  would  be  if  the  quantity  were  the  normal  amount  of  1,200 


and  is  obtained  by  the  formula  D  = 


QXd 


cc.»  and  is  obtained  by  ttie  formula   1^  =  ^^*  iii  which  Q  is  the 

quantity  of  urine  in  24  hours,  and  d  the  last  tw^o  figures  of  the 
observed  sp,  gr.  Example:  Q  =  600  cc.,  d  ^20,  then  600X20-^ 
1200  —  10;  sp.  gr.=l,010.  The  sp.  gr.  gives  a  rough  indication  of 
the  quantity  of  total  solids.  The  last  two  figures  of  the  sp.  gr., 
multiplied  by  2.33  gives,  iu  normal  urine,  approximately  the  amount 
of  total  solids  p/m.  Example:  sp.  gr.  =  1,017,  17X2,33=39.61 
grams  of  solids  iu  1,000 cc.  This  rule  does  not  hold  good  if  the 
urine  contains  sugar  or  allmmin.  Generally  the  sp.  gr.  vnrirs 
inversely  as   the  quantity.     But  in  diabetes   mellitns   the  quantity 


696 


HAMTTAL   OF   CHEMISTKV 


4 


is  large  and  the  sp.  gr.  high.  The  quantity  is  dimnished  and 
the   sp*  gr.  is   low  in  obstructive  suppression,  in  the  later  stages 

of  fatal  diseases  attended  with  defective  elimination  of  solids,  in 
cedema,  and  in  diseases  attended  with  copious  diurrha^a,  vomitinfj 
or  sweating.     For  methods  of  detemHuing  sp.  gr,»  see  page  11. 

Color. — The  color  of  the  normal  urine  varies  from  a  very  pale 
yellow  to  a  brownish -orange,  being  darker  when  couceutrated  thau 
when  dilute,  and  also  darker  when  strongly  aeid.     Clinically,  urines 
may  be  divided,  according  to  color,  into  pale,  norma* ,  high -colored^ 
and  dark.     The  urine  is  pale  when  its  quantity  is  increased.     Nor 
mally-coloi*ed  urines  are  of  negative  significance  only.     High-colored 
urines  owe  their  color  to  the  presence  of  the  normal  urinary  coloring- 
matters  in  increased  amount  (p.  725),     They  occur  in  all  forms  o^fl| 
acute  febrile  disease,  and  indicate  increased  activity  of  tissue  ehange.^^ 
Concentrated   urines   are   high-colored.     Dark  urines  vary   iu   color 
from   orange-red    to    black.     Exceptionally  tlie  urine  may  be  dark 
from  the  presence  of  gi-eatly  increased  quantity  of  normal  coloriDg- 
matter,  as  in  beri-beri;    but  usually  a  dark  urine  owes  its  color  ti 
the  presence  of  an  abnormal  pigment:    red  or  reddish -brown  from 
the  presence  of  blood-pigment;   brownish -yellow,  greenish -brown  or 
dark -brown  from  bile  coloring -matters;  smoky  <  violet  or  black  frora 
dci'ivatives  of  carbolic  acid,  resorcinol,  salol,  or  salicylic*  acid;  golden- 
yeUow  from  snntoniu;   yellow,  changing  to  blood -red  with  alkalies, 
from  chrysophanie  acid  (rhubarb,  easeara,  senna).     In  chyluria  the 
urine  is  white  and  nulky. 

Odor.^When  freshly  voided,  the  odor  of  the  urine  is  faint  and 
aromatic,  but  on  standing  it  rapidly  develops  the  urinous  odor,  and 
finally  that  of  ammonia.  Certain  fo<rd  and  medicinal  substanceSf 
such  as  asparagus,  copaiba  and  turpentine*  communicate  peculiar 
odors  to  the  urine.  Iu  diabetes  the  urine  has  a  faint,  but  distinct, 
" sweet '^  odor. 

Reaction* — The  reaction  of  the  urine  depends  largely  upon  the 
nature  of  the  diet.  In  herbivora  it  is  neutral  or  alkaline;  iu  the 
earnivora  strongly  acid.  The  urines  of  suckling  herbivorous  animals 
and  that  of  adults  during  starvation,  conditions  in  which  the  animals 
are  practically  carnivorous,  are  acid.  The  reaction  of  the  normal 
human  mixed  urine  of  24  hours  is  always  acid.  Samples  collected 
at  different  times  of  the  day  may  be  normally  acid»  alkaline  or 
amphoteric.  After  meals  the  acidity  of  human  urine  diminishes, 
and,  during  the  period  of  greatt^'^t  activity  of  stomach  digestioD*  it 
may  even  become  alkaline  (p.  610).  If  the  urine,  after  having  been 
voided,  is  kept  at  the  ordinary  temperature,  its  acidity  rapidly  diniia* 
ishes,  and  it  becomes  alkaline  and  ammoniacal  from  decomposition 
of  the  urea.     It  then  becomes  cloudy,  from  deposition  of  phospbateSt 


i 


4 


\ 


UBINE 


697 


gome  times  of  calcium  oxalate,  and  later  of  ammonium  urate.  The 
acidity  of  the  urine  may  be  increased  by  administration  of  dilute 
mineral  acids,  but  not  beyond  a  certain  degree.  It  may  be  dimin- 
ished by  administration  of  dilute  alkalies  or  of  vegetable  acids  or 
their  salts,  which  are  oxidized  in  the  system  ro  carbonates.  The 
acid  reaction  of  the  urine  is  due,  to  some  extent,  to  the  presence 
of  carbonic  acid,  but  principally  to  that  of  monometallic  phosphates* 
Uric  acid  does  not  occur  free,  but  in  combination,  in  normal  urine; 
therefore  it  do*^s  not  contribute  dircetly  to  the  auidity»  but  indirectly 
it  is  largely  coucerned  in  the  production  of  the  acid  reaction.  The 
alkaline  phosphates  of  the  blood  are  converted  into  acid  phosphates 
and  urates  by  reaction  with  uric  acid  ;  Na2HP04  +  C5H4N4O3  = 
NaH^POi+NaCsHaNjOa;  and  a  further  formation  of  acid  phosphate 
from  alkaline  phosphate  results  from  the  action  of  sulfuric  acid, 
produced  by  oxidation  of  the  sulfur  of  the  proteins,  and  of  hydro- 
chloric acid  reabsorbed  with  the  peptones. 

The  acidity  is  more  intense  than  normal  in  concentrated  urines, 
in  fevers,  gout,  acute  articular  rheumatism,  leukaemia,  scurvy,  and 
sometimes  in  diabetes.  The  acidity  of  diabetic  urine  frequently  in- 
creases after  it  is  voided,  with  separation  of  crystals  of  uric  acid, 
from  the  formation  of  acids  by  fermentation.  The  reaction  may 
become  alkaline  from  the  presence  of  fixed  alkalies,  carbonates,  or 
alkaline  phosphates,  or  of  volatile  alkali,  ammonium  carbonate* 
Physiologit^al  snbncidity  or  alkalinity  is  always  due  to  the  former, 
which  are  also  the  cause  of  the  alkalinity  occurring  in  ana:'mia, 
after  cold  baths,  after  absorption  of  alkaline  transudates,  and  after 
administration  of  organic  acids  or  mineral  alkalies.  Alkalinity  from 
Vi>latile  alkali  always  result^s  from  decomposition  of  urea,  which 
takes  place  in  the  bladder  in  cystitis. 

The  reaction  of  the  urine  has  an  important  bearing  upon  the 
formation  of  calculi.  Much  the  larger  proportion  of  urinary  calculi 
are  either  pbosphatic  or  uric  acid,  and  the  conditions  of  reaction 
under  which  the  two  kinds  are  formed  are  the  diametrical  oppositesj 
the  deposition  of  nric  acid  requires  a  strongly  acid  urine,  while  the 
ph'^»^phatcs  are  deposited  fniru  subneid  or  alkaline  urines.  Uric 
acid  t^alculi  and  '^gravel"  are  more  usually  of  renal  origin,  phosphatic 
calculi  never.  When,  as  frequently  occurs,  a  uric  acid  calculus  forms 
the  tiuclens  of  a  large  phosphatic  calcolns,  the  uric  acid  nucleus 
was  formed  in  the  kidney  in  a  strongly  acid  urine,  and,  coming 
down  into  the  bladder,  has  been  the  cause  of  a  cystitis  by  mechanical 
irritation,  which,  in  turn,  has  prodnced  an  alkaline  or  subacid  urine, 
from  which  the  phosphates  have  been  deposited  upon  the  uric  acid 
nucleus. 

The  quality  of  the  reaction  is  best  determined  in  the  usual  way. 


C38 


MANUAL    OF    CHEMISTKY 


dor 


iv'ith  litmus  paper.    If  the  reaction  he  alkn^ine  tbc  blued  red  litmus 
allowed  to  dry  in  a  plaee  protet^ted  from  acid  fumes.     If  the  color 
returns  to  red  on  drying  the  alkalinity  is  due  to  volatile  alkali,  whl 
if  the  blue  eolor  persists »  it  in  due  to  fixed  alkali. 

The  determination  of  the  degree  of  acidity  cannot  be  accomplish 
in  the  usual  way,  by  titration  with  standard  alkaline  solutions 
stated  above,  the  acidity  of  the  urine  is  due  almost  entirely  to  the 
presence  of  aeid  phosphates,  notably  of  acid  sodium  phosphale,  or 
uionosodic  phosphate,  NaH^PO^.  But  the  urine  also  contains  disodic 
(and  dipotassic)  phosphate,  NajHPO*,  whose  reaction  is  faintly  alka- 
line, the  two  salts  being  in  varying  proportion  to  each  other.  If 
now  au  alkaline  solution,  such  as  a  N/IO  solution  of  caustic  soda  be 
added  to  the  mixture  of  the  two  salts  in  solution,  the  monosodie  sal^H 
is  converted  into  the  disodie  :  NaH-iPO4+NaH0==Na2nPO4+H2O,* 
aud  a  time  is  reached  when  the  proportion  of  the  two  is  such  that  the 
reaction  is  not  neutral,  i.  e,,  without  iufluenee  upon  the  indicator, 
but  amphoteric,  i.  e.,  turning  red  litmus  blue  and  blue  litmns  red. 
As  the  measure  of  the  degree  of  acidity  of  the  urine  is  the  amount  of 
pljosphoric  acid  (P2O5)  present  in  monometallic  phosphates,  the  de- 
ternii nation  of  the  acidity  depends  upon  that  of  phosphoric  acid  in  its 
two  forms  of  combination,  as  monometallic  and  dimetallic  salts. 
This  is  done  by  the  Freund-Lieblein  method:  The  total  phosphoric 
acid  (T)  is  first  determined  hy  the  method  described  on  p.  706.  To 
another  sample  of  75  ce,  of  urine,  15  cc.  of  barium  chlorid  solutioi 
(122  gnu  BaCl2,2H20  to  the  litre)  are  added,  by  which  the  dimetallii 
phosphates  (M)  are  precipitated,  while  the  monometallic  phosphates 
(D)  remain  in  solution.  The  mixture  is  shaken,  and  filtei-ed  aud 
refiltered  until  the  filtrate  is  clear,  Sixty  cc.  of  the  clear  filtrate, 
representing  50  cc,  of  urine,  are  taken  for  a  second  phosphoric  acid 
determination  by  the  same  method.  As  in  the  treatment  with  barium 
chlorid,  there  oecni's  a  partial  conversion  of  one  phosphate  into  an- 
other, by  reason  of  which  about  3%  of  the  phosphoric  acid  of  the 
dimetallic  phosphate  remains  in  solution  as  monometallic  salt,  a  cor 
rection  is  here  necessary,  and  is  made  by  subtracting  8%  from  the 
result  of  the  second  determination.  The  corrected  result  (D)  rcpi 
sents  the  phosphoric  acid  present  in  monometallic  phosphates* 

Freezing  Point — Cryoscopy. — We  have  seen  (p.  68)  that 
depression  of  the  freezing  point  of  a  solution  below  that  of  the  pure 
solvent  is  a  measure  of  the  osmotic  pressure  of  the  dissolved  sub- 
stances, and  (pp.  67,  73)  that  the  osmotic  pressure  at  constaut  tem- 
perature is  proportionate  to  the  number  of  particles,  molecules  and 
ions,  present  in  unit  volume  of  the  solution.  Therefore  the  determi- 
nation of  the  depression  of  the  freezing  point  of  urine  below  that  of 
water,  called  a  "cryoscopic  examination,"  affords  an  excellent  indicalioa 


1 


the      , 

I 


4 


tJRINE 


699 


of  its  concentration  in  both  ionized  and  non- ionized  constituents. 
While  the  depression  of  the  freezing  point  of  blood  is  almost  constant 
Ht  ^  — O^oG"^,  that  of  the  trrine,  which  is  more  concentrated,  is  greater, 
and  varies  usually  between  ^  — 1.3°  and  — 2.0°.  When  the  urine  becomes 
diluted,  as  after  the  ingestion  of  hirge  amounts  of  liquid,  ^  may  fall 
to  — 0. 1*^,  and  when  it  becomes  highly  concentrated  *^  tnay  rise  to  — 3.0"^. 

Electrical  Conductivity. — The  electrical  conductivity  of  a  liquid 
(p.  42)  is  in'oporlionate  to  the  number  of  free  iuns  present  (p.  74). 
It  will  therefore  vary  with  variations  in  the  proportion  of  eleclroivtes, 
such  as  nuneral  salts,  w^hich  are  present  in  the  solution,  but  will  nut 
be  affected  by  variatioTis  in  the  proportion  of  non -electrolytes,  such 
as  urea  and  the  other  organic  eonstttuents  of  the  urine,  except  that 
tfiese,  by  oifering  resistance  to  tlje  passage  of  the  current,  |>roduee  a 
elight  diuiinuiion  of  tlie  total  couduetivily  behiw  that  which  wunld  be 
observed  with  solutions  of  equal  quantities  of  the  same  salts  in  the 
same  volume  of  pure  water.  But,  with  this  slight  error,  the  determi- 
nation of  the  conductivity  iif  the  urine  gives  an  indicatiun  of  its  degree 
of  concentration  iii  mineral  salts,  and  by  cotnparison  of  the  results 
obtained  by  this  method  with  those  of  the  eryoscopic  exumination  it  is 
possible  to  determine  what  fraction  of  tlie  osmotic  pressure  is  due  to 
non -electrolytes  and  what  to  electn*lytes.  The  chlorids  in  the  urine 
constitute  the  greater  part  of  the  electrolytes  present,  and  they  are 
subject  to  wide  variations,  not  dependent  upon  metabolic  processes, 
but  upon  varying  amounts  of  NaCl  taken  with  the  food.  The  sulfates 
and  phnspbales,  on  the  other  hand,  arc  largely  the  products  of  meta- 
bolism of  sulfur-  or  phosphorus-eontaining  organic  substances. 
Attempts  have  been  made  to  study  the  variations  in  organic  sulfur 
and  phosphorus  metabolism  by  determinations  of  ckn-trical  c<indue- 
livity,  subtracting  from  the  results  obtained  the  calculated  conductivity 
due  to  ehlorids,  based  upon  chlorin  determinations,  but  the  results 
cannot  be  considered  us  having  been  satisfactory.  It  is  to  be  expected, 
however,  tluit  the  eryoscopic  and  conductivity  methods  will  pro%'e  of 
considerable  value  in  the  future,  as  the  mineral  salts  appciir  to  have  a 
greater  intlnence  upon  the  ehemism  of  the  body  than  they  were  for- 
merly supposed  to  exert. 

It  is  clear  tlnit  the  conductivity  of  the  urine  must  vary  at  different 
times  of  the  day,  according  to  the  quantity  of  electrolytes  in  the  diet 
and  the  activity  of  their  elimination.  It  is  usually  within  the  liniits 
of  «=o,oi49  and  0.03U3  (pp.  42,  46,  74). 

CHEMICAL  COMPOSITION. 


The  constituents  of   the  urine  may  be  divided  into  two  classes: 
normal  and  abnormah     Clinically  some  normal  constituents,  such  ns 


700 


MANUAL    OF    CHEMISTRY 


sugar,  which  are  present  in  heaUhy  nriue  in  quantities  so  small  as  toj 
escape  detection  by  the  tests  ciistoTnarily  used,  bnt  are  greatly  in- 
creased in  disease,  are  ranked  as  abnormal  eonstitnents.  It  is  clear 
that,  as  the  normal  constituents  are  constantly  present,  we  can  only 
obtain  indications  of  clinical  value  by  their  variations  in  quantity. 
The  mere  presence  in  detectable  quantity  of  the  abnormal  constituents 
indicates  a  pathological  condition,  the  gravity  of  which  is  fi'equently 
proportionate  to  the  quantity  of  the  abnormal  constituents  voided. 
Quantitative  determinations  of  both  normal  and  abnormal  constit- 
uents therefore  constitute  a  large  part  of  urine -analysis.  As  it  has 
been  found  that  the  elimination  of  all  constituents  of  the  urine  is 
subject  to  variation  at  different  times  of  the  day  under  different  con- 
ditipns  of  eating,  sleeping,  exercise,  etc.,  quantitative  results  ob- 
tained with  the  morning  urine  are  not  comparable  with  those  obtained 
from  afternoon  urine,  indeed  the  only  quantities  which  are  com- 
parable witb  each  other  are  the  amounts  excreted  in  24  hours,  and  no 
qnauiifaiive  deiernunatmn  should  he  made  except  with  samples  of  thf 
mixed  and  measured  tirine  of  24  hours* 

The  normal  constituents  of  the  urine  are  classified  into  the  two 
groups  of  mineral  and  organic. 


MINERAL    CONSTITUENTS. 


The  mineral  salts  are  ehlorids,  sulfates,  and  phosphates  of  potas- 
sium, sodium,  ammonium,  calcium,  and  magnesium,  with  traces  of 
silioic  acid.  Of  the  bases  sodium  and  potassium  are  the  most 
abundant,  and  of  the  acidulous  factors  chlorin.  In  the  urine  of  24 
hours  the  quantity  of  acid  present  is  in  excess  of  that  required  to 
completely  neutralize  the  amount  of  base  present,  and  that,  notwith- 
standing the  fact  that  a  portion  r»f  the  bases  exist  in  organic  combi- 
nations not  here  considered;  from  which  it  follows  that  a  portion  of 
the  salts  must  be  incompletely  saturated,  or  add  salts,  such  as  acid 
sodium  phosphate,  NaH^PO*,  and  it  is  to  these  that  the  urine  owes 
its  acidity.  It  is  convenient  to  classify  the  salts  of  the  urine  accord- 
ing to  their  acids,  rather  than  according  to  their  bases,  into  cblorids, 
sulfates  and  phosphates. 

Chlorids*— The  chlorids  pi^sent  are  those  of  all  the  bases  men- 
tioned above,  but  sodium  chlorid  largely  predominates,  and  it  is  usual 
to  calculate  all  of  the  chlorin  found  on  analysis  as  sodium  ifhlorid. 
The  usual  amount  of  chlorids  eliminated  is  from  10  to  15  gms.  NaCl 
in  24  hours.  It  is,  however,  subject  to  great  variations,  chiefly  due 
to  differences  in  the  quantity  of  salt  taken  with  the  food  by  different 
individuals.  The  elimioation  is  less  during  the  night  than  during  the 
daytime.     When  NaCl  is  excluded  from  the  diet  its  elimination  by 


4 


I 


URINE 


701 


the  urine  ceases  before  it  disappears  from  the  blood.  Numerous  de- 
terminatious  of  chlorids  in  various  diseased  couditioDS  have  been 
iiiade»  but  it  must  be  remembered  that  the  observed  departures  from 
the  normal  may  be  due  in  large  part,  if  not  entirely,  to  variations  in 
the  amount  of  salt  ingested^  or  to  removal  of  chlorids  by  other 
ehannels.  The  extremes  of  reported  variations  are  from  0  to  aO  gms. 
in  24  hours,  DiniiDished  elimiuation  has  been  observed  in  acute 
febrile  diseases,  .st-arlatina,  roseola,  vai'iola,  typhus,  typhoid  pneu- 
monia, yellow  atrophy,  in  all  acute  renal  diseases  with  albuminuria, 
in  carniuonia  of  the  stomach,  gastric  ulcer,  antemic  conditions, 
ricketi?.  melaucholia,  idiocy,  dementia,  chorea,  paralysis,  impetigo, 
peinphig'us.  during  formation  of  exudates,  with  diarrhoea,  and  in 
idironie  lead  pnisoniug.  lucreased  elimination  oceui"s  in  acute  dis- 
eases during  reabsorptiou  attended  with  diuresis,  in  diabetes  insipi- 
dus, (luring  the  polyuria  fol lowing  attacks  of  epilepsy,  and  in  general 
paresis  when  large  aniouuts  of  food  are  taken. 

The  usual  methods  of  quantitative  determination  of  chlorids 
are  by  titration  with  SJilver  nitrate  solution,  either  by  Mohr's  or  Vol- 
hard't^  method.  The  former  is  the  moat  generally  applicable  if  inter- 
fering substances  be  first  removed.  If  the  urine  contain  albumin* 
this  is  first  removed  by  coagulation  and  filtration.  Ten  cc.  of  the 
albumin -free  urine  are  placed  in  a  platinum  crucible  along  with  about 
1  gin,  of  pure  (CI -free)  NaiCO^  and  about  2  gm.  pure  KNO3,  and 
evaporated  to  dryness.  The  residue  is  cautiously  heated  to  fusion, 
cooled,  dissolved  in  water,  and  faintly  acidulated  with  IINOn.  If 
bromids  or  iodids  be  present  they  must  be  removed  at  this  point 
by  adding  dilute  H2SO4  and  a  little  sodium  nitrite  to  the  solution,  and 
shaking  it  with  successive  portions  of  carbon  disulfid  until  colorless. 
The  aqut^ous  soluti*'»n  is  placed  in  a  porcelain  dish,  with  a  similar  dish 
containing  an  equal  quantity  of  water  alongside  for  com  pari  sou  of 
tint;  a  few  drops  of  neutral  potassium  chromate  solution  are  added 
to  the  contents  of  each  dish;  and  the  silver  solution  is  gradually 
added  to  the  chlorid  solution  until,  after  stirring,  it  has  a  faint  red- 
dish tinge  as  compared  with  the  contents  of  the  second  dish.  The 
silver  solution  used  may  be  either  a  N/10  solution,  containing  17.00 
gm.  of  pure,  crystallized  AgNOy  to  the  litre,  each  cc.  of  which  repre- 
sents 0.00585  gm.  NaCl  in  the  10  cc.  of  urine  used;  or  a  solution 
containing  29.054  gm.  AgNOa  to  the  lilre,  each  ec.  of  which  repre- 
sents 0.01  gm.  NaCl.  The  result,  multiplied  by  1/10  the  quantity  of 
iirioe  in  24  hours,  gives  the  daily  elimination. 

VoUmrd\H  niflhod  consists  in  precipitating  the  chlorids  completely 
by  an  excess  of  silver  nitrate  (20  cc.  of  the  second  silver  solution 
mentioned  above)  filtering,  and  determining  the  excess  of  silver  salt 
in  a  portion  of  the  filtrate  by  titr&tion  back  with  a  solution  of  potae* 


702 


MANUAL    OF    CHEMISTRY 


siiira  thiocyouate  ctiiitainiug  8.3  gm.  KCNS  lo  tbe  litre  (2  cc. 
which  ^1  ce.  AgNOn  solution)  usitij^  a  solulioii  uf  a miiiouio- ferric  al 
as  an  indicator,  aud  .siiblrtietijii^  tiiis^  iroin  ike  total  AgNU:i  added* 
*  Sulfates,^— The  sulfatL-s  ui'  the  urine  are  of  j^reaLcr  physiological 
interest  than  the  chloridg.  The  latter  are  not  formed  in  the  body,  and  J 
variations  in  their  elioiinatiou  depend,  praetieally  entirely^  ui>on 
variations  in  the  amounts  taken  with  the  food  aud  drink.  The  aui* 
fates,  on  the  other  hand,  are  only  present  in  the  fuud  and  in  natural 
waters  in  small  amount,  and  the  greater  part  of  these  salts  in  the  urine 
are  produced  in  the  hudy  by  nietabulism  of  the  eystin  complex  of  the 
proteins,  and  therefore  variations  in  their  eliminatiou  aflford  indiea* 
tious  of  the  degree  of  activity  of  metabolic  change  of  the  organic  I 
compounds  from  which  they  are  derived.  The  relation  of  nitrogen  to 
sulfuric  acid  in  tbe  urine  is  quite  constant  at  5N  to  I8O3. 

A  portioii  of  the  sulfuric  acid  thus  formed  by  oxidation  combines  I 
with  the  bases  to  produce  sodium  aud  potassium  sulfates,  with  lesser] 
aiimnnts    of    calcium    mid    magnesium    sulfates,    and»    exceptionally, 
ammonium  sulfate.    These  coustitute  the  "mineral  sulfates."    Another 
portion  coudjines,  probably  in  the  liver  (p,  684),  with  phenolic  couj- 
pounds  to  produce  the  sodiniu  and  potassium  salts  of  the  "ester  sul- 
fates," or  "conjugate  sulfates''  (pp,  541,  646,  728).     Not  aU  t»f  the 
sulfur  of  the  proteins  is  thus  oxidized  to  sulfates,  whether  mineral  ur, 
ethereal,  but  a  portion  is  eliminated    in  organic    combination,  in  a( 
variety  of  siibstauces,  in  which  form  it  cousti^tutes  the  "^^  neutral  sni* 
fur-'   (p.  730).     The  average  daily  elimination  of  mineral    sulfates, 
with  a  mixed  diet,  is  1.5  to  3,0  gms.  SO:i,  that  of  ester  sulfates  0.15 
to  0.3  gra.  SO3.     The  relation  between  these  two  forms  is,  however, 
quite  variable,  aud  the  proportion  of  ester  sulfates  present  indicates  I 
the  degree  of  activity  of  putrefactive  changes  in  the  intestine,  or  off 
retention  and  absorption  of  their  products,  in  the  absence  of  adminis- 
tration of  phenolic  compounds,  or  the  absorption  of  putrid  products 
from  other  sources.     The  proportion  of  ester  sulfates  is  increased  in 
fjecal  retention,  in  obstructive  jaundice,  in  septccemia,  and  in  hypo- 
cblorhydria.    In  poisoning  by  phenols  the  mineral  sulfates  are  reduced 
to   zero,    and   the   ethereal   sulfates   correspondingly  increased.     In 
diarrhoea  both  forms  are  diminished,  while  in  acute  leukemia  both 
are  increased. 

Analytically,  sulfur  is  deterraiued  in  the  urine  in  three  forms  uf 
combination,  either  directly  or  by  difference:    (1)   As  mineral  sulfa! t^s, 
(2)   as  ester  sulfates,    (3)   as  neutral  sulfur,   and  best  by  FoliJi^il 
metliod. 

Miiifrai  sulfates. — To  25  cc.  of  urine,  in  a  250  cc.  Erlenmeyer-^ 
flask  add  100  cc,  of  water  aud  10  cc.  of  dilute  HCl  (I  vol.  cone.  HCI 
to  4  vnLs.  H2O).     If  the  urine  l>e  dilut(\  use  50  cc.  urine  and  50  cc. 


4 

I 


I 


rniKE 


703 


water.  To  the  diluted,  acidulated  and  cold  liquid  add  10  ec,  of  a  5 
per  cent  solutiou  of  BaCl2,  without  agitatiou  or  disturbauce,  drop  by 
drop,  and  slowly*  At  the  end  of  an  hour,  or  later,  the  mixture  is 
shaken  up  and  the  precipitate  collected  oo  a  long-tibered  asbestos 
film,  in  a  poreelaiu  Gooch  crucible,  with  moderate  suction.  The  pre- 
cipitate is  then  washed  with  250  cc.  of  cold  water,  dried,  and  ignited 
in  the  covered  crucible,  supported  upou  the  lid  of  a  platinum  crucible, 
for  about  ten  miuutes. 

Total  sulfates. — To  decompose  the  ester  sulfates,  25  cc.  of  urine 
and  20  cc.  of  dilute  HCl  (1:4  as  above),  or,  if  the  urine  be  dilute, 
50  cc.  of  urine  and  4  cc.  of  concent  rated  HCl,  are  gently  boiled  in  a 
250  cc,  Erleomeyer  flask,  whose  raouth  is  covered  with  a  watch-glass, 
for  half  an  hour.  The  flask  is  cooled  for  two  or  three  minutes  in  run- 
ning water,  and  the  contents  diluted  with  cold  water  to  about  150  cc. 
To  this  cold  solution  10  cc.  of  5  percent  l^aCh  are  then  added,  with 
the  precautions  mentioned,  and  the  process  concluded  as  above.  The 
total  sulfates,  minus  the  mineral  sulfates,  gives  the  ester  sulfates. 

Total  snifttr. — The  organic  sulfur  is  oxidized  to  sulfates  by  sodium 
peroxid:  25  ce.  of  the  urine,  or  fyO  cc.  if  very  dilute,  are  measured 
into  a  250  cc.  nickel  crucible,  and  about  3  gras.  of  sodium  peroxid 
are  added.  The  mixture  is  evaporated  to  a  syrup,  and  then  carefully 
heated  until  it  solidifies,  the  latter  heating  occupying  about  fifteen 
minutes.  The  crucible  is  then  cooled;  the  residue  moistened  with 
1*2  cc.  of  water;  about  7  gms.  of  sodium  peroxid  are  sprinkled  upon 
it;  and  the  mixture  heated  to  complete  fusion  for  about  ten  minutes. 
After  cooling,  the  foo tents  of  the  crucible  arc  heated  with  about 
100  uc.  of  water  for  al>out  half  an  hour,  to  dissolve  the  alkali  and 
decompose  the  sodium  peroxid.  The  mixture  is  then  rinsed  into  a 
450  cc,  Erlenmeyer  flask  with  hot  water,  and  the  bulk  of  thi*  liquid 
made  up  to  about  250  cc.  Concentrated  IICl  is  then  slowly  added  to 
the  almost  boiling  liquid,  until  the  nickelic  oxid  just  dissolves,  which 
requires  about  18  cc.  of  acid  for  8  gms.  Na^Os-  After  a  few  minutes* 
boiling,  the  liquid  should  be  perfe^'tly  clear,  unless  too  much  water  or 
too  little  peroxid  have  been  used  in  the  final  fusion.  If  not  clear  the 
liquid  must  be  cooled  and  filtered.  To  the  clear,  acid  solution  5  cc. 
of  dilute  alcohol  (1  part  alcohol  to  4  parts  water)  are  added  and  the 
boiling  continued  for  about  five  minutes,  to  remove  traces  of  chlurio. 
Ten  cc.  of  10  per  cent  BaCli  solution  are  then  added,  with  the  same 
precautions  as  above,  and  the  mixture  is  left  standing  in  the  cold  for 
two  days,  after  which  the  process  is  concluded  as  above.  The  amount 
of  neutral  sulfur,  as  80a,  is  obtained  by  subtracting  the  value  ob- 
tained for  the  total  sulfates  from  that  for  the  total  sulfur. 

Phosphates. — The  phosphates  present  in  the  urine  are  those  of 
sodium,   potassium,  eaieium  and    nnignesia.    The  Na  and  K  phos- 


704 


MANUAL    CF    CHEMISTRY 


pbates,  wliich  include  the  mooometallie  and  dinietallie  salts,  are  kno^vu 
as  alkaline  phosphates  {p.  698),  those  of  Ca  and  Mg  as  earthy  phos- 
phates. About  two -thirds  of  the  total  phosphoric  acid  is  contained 
in  the  alkaline  phosphates,  of  which  the  sodium  salts  are  greatly  in 
excess  of  the  potassium »  and  one* third  in  the  earthy  phosphates. 
The  average  eliniination  of  phosphoric  acid  (P2O5)  is  2.5  to  3  gm. 
per  diern^  but  it  may  vary  within  normal  limits  from  1  to  5  gm.  a 
day.  This  variation  depends  largely  upon  the  nature  of  the  diet,  the 
amount  being  larger  with  an  animal  than  with  a  vegetable  diet, 
except  the  latter  contain  cereals,  which  are  rich  in  phosphates,  ia, 
large  amounts,  A  notable  quantity  of  phosphates  arc  contained 
iu  food  articles,  both  in  alkaline  and  in  earthy  combination,  of  which 
the  former  are  Readily  absorbed^  while  the  latter,  being  soluble 
only  in  acid  liquids,  are  in  large  part  passed  with  the  faeces.  A 
part  of  the  urinary  phosphates  are  also  formed  in  the  system  as 
products  of  oxidation  of  the  phosphorus  existing  in  the  albumins, 
nucleoproteids,  nucleins,  protagon  and  the  lecithins.  The  propor- 
tion between  the  amounts  nf  nitrogen  and  of  phosphoric  acid  elinj- 
inated,  sometimes  called  the  *' relative  value"  of  phosphoric  aeid,  id 
calculated  by  the  formula  NiP^Os:  :100;x.  Normally  the  value  of 
is  from  17  to  20;  thus,  taking  the  average  elimination  of  nitnige 
as  14  gm,,  ant!  of  phosphoric  acid  as  2.5,  the  value  of  x  would  be 
17.85.  While  variations  in  this  relation  depend,  in  some  raeasnre, 
upon  differences  in  the  composition  of  food  articles  ingested,  they 
also  de]>end  upon  differences  in  the  character  of  tissue  changes  whic 
may  be  exaggerated.  The  value  of  x,  obtained  by  the  above  for- 
mula, would  differ  notably  according  as  the  N  and  P2O5  are  derived 
by  oxidation  of  album  ins,  on  the  one  hand,  or  of  other  phosphoruis 
containing  substances  on  the  other: 


i 


N 

P 

P,05 

X 

Albumins   .   * 

/  15.C0  . 
'   117,60. 

.  0,42  . 

.    0.96  . 

-NiP.Os: 

:100:    6.40 

.  0.85  . 

.    1.95, 

.N-.P^O,: 

:100:  11,07 

NucleohiBton  * 

.   .   .16,96. 

.  a.03  , 

,    6.93  . 

.NiPsOs: 

:100:  41.10 

Pro t agon     .    . 

.   .   .    2.80  . 

.  1.123  . 

.    2.82  . 

.    .N:PA: 

: 100 1100.71 

Bone     ,   .    .    . 

.    .        6.44  . 

.... 

.  26.76  , 

.    .N:P.Ov: 

:  100:4 15.52 

L&citbina    .   . 

•   .   .    1.73  * 

.  3.84  . 

.    8.70  . 

.    ,N:P304: 

1100:508.00 

It  is  evident  from  the  above  that  an  increase  in  the  relative 
value  of  phosphoric  acid  may  be  expected  uuder  conditions  involving 
either  an  increased  tissue  change  in  bone»  with  eHminatiou  of  its  1 
phosphates^  or  increased  metabolism  of  tissues  rich  in  nucleated  cells,  ^| 
fc>uch  is  the  case  in  starvation,  in  which  both  the  absolute  and  rela- 
tive elimination  of  phosphoric  acid,  as  well  as  that  of  calcium  com- 
pouudSt  are  notably  increased.     With  increased  mental  activity,  also, 


UUINE 


705 


the  elimination  of  earthy  phosphates  is  iDcreaaed,  and  that  of  alkaline 
phosphates  diminished. 

Pathologically  the  elimination  of  phosphoric  acid  is  dimioiiihed 
in  acute  febrile  diseases,  ehrooic  nephritis,  amyloid  degeneration  of 
the  kidney »  hysteria,  Addison's  disease,  acute  yellow  atrophy  of  the 
liver,  and  in  lead  poisoning.  It  is  increased  in  convalescence  from 
acute  diseases,  meningitis,  epilepsy  and  leukaemia,  and,  parlicniarly, 
in  '^phosphatic  diabetes,"  in  which  the  elimination  of  phosphoric 
acid  may  reach  8  to  9  gni.  in  24  honrs,  and  in  which  the  other 
symptoms  of  diabetes  are  prci^ent,  bnt  there  is  no  glyeosnria.  In 
diabetes  melHtus  the  quantity  of  phosphoric  acid  is  subnoruuii,  yjar- 
ticularly  when  the  quantity  of  sugar  is  large. 

The  earthy  phosphates  only  are  concerned  in  the  formation  c»f 
calculi.  So  long  as  the  reaction  of  the  urine  (p,  697)  remains  acid 
they  are  held  in  solution,  bnt  when  the  reaction  becomes  alkaline, 
or  even  on  loss  of  CO2  on  exfjosure  to  air,  the  insoluble  triuietalHc 
salts  are  formed  and  deposited.  Alkaline  urines  are,  for  this  reason, 
almost  always  tnrbid,  and  become  clear  upon  addition  of  an  acid. 
It  is  in  such  urine  that  phosphatic  calculi  are  always  formed, 
usually  about  a  nucleus  of  uric  acid,  or  of  a  foreign  body.  If  the 
alkalinity  be  due  to  the  formatiou  of  ammonia,  the  ammonto  -  mag- 
nesLum  phosphate,  or  triple  phosphate,  Mg(NH4)P04,  is  produced, 
either  in  the  form  of  large,  tubular  crystals,  or  as  a  fusible  calculus. 

A  process  for  the  quantitative  detenrii nation  of  phosphoric  acid 
in  the  urine  is  based  upon  the  formation  of  the  insoluble  uranium 
phosphate,  and  upon  the  production  of  a  brown  color  when  a  solution 
of  a  uranium  salt  is  brought  in  contact  with  a  solution  of  potassium 
ferrocyanid.  Four  solutions  are  required:  (1)  a  standard  Holution  of 
difiodic  pJtosjriliate,  made  by  dissolving  10,085  grams  of  crystal lizt-il. 
uon- effloresced  HNa2P04  in  Ht;0,  and  diluting  to  a  litre;  (2)  an  atud 
mluiion  of  sodium  aceiatt,  made  by  dissolving  100  grams  sodium  ace- 
tate in  H2O,  adding  100  cc.  glacial  acetic  acid,  and  diluting  with  O-iO 
to  a  litre;  (3)  n  strong  sointhn  of  potassium  ferronjanid ;  (4)  a 
standard  solution  of  uranium  acetate,  made  by  dissolving  20. S  grams 
of  yellow  uranic  ox  id  ia  glacial  acetic  acid,  and  diluting  with  H^O  to 
nearly  a  litre.  Solution  1  serves  to  determine  the  true  strength  of  this 
Bolntion,  as  follows:  50  cc.  of  Solution  1  are  placed  in  a  beaker,  5  cc* 
of  Solution  2  are  added,  the  mixture  heated  on  a  water- bath,  and  the 
uranium  solution  gradually  added,  from  a  burette,  until  a  drop  from 
the  beaker  produces  a  brown  color  when  brought  in  contact  with  a 
drop  of  the  ferrocyanid  solution.  At  this  point  the  reading  of  the 
burette,  which  indicates  the  number  of  cc.  of  the  uranium  solution, 
corresponding  to  0.1  — P2O5,  is  taken.  A  quantity  of  H^O,  deter* 
mined  by  calculation  from  the  result  thus  obtainedt  is  then  added  to 


45 


706 


MANUAL    OF    CHEMISTRY 


ilent 


the  remaming  uraniam  solution »  such  as  to  rentier  each  cc.  equivalent 
to  0.005  gram  PaOs. 

To  determine  the  total  phosphates  in  a  urine:  50  cc.  are  plac 
ill  a  beaker,  5  cc.  sodium  acetate  solution  are  added;  the  mixture 
heated  on  the  water-bath,  and  the  urauinni  solution  delivered  froraj 
burette,  until  a  drop,  removed  from  the  beaker  and  brought  iu  coil 
tact  with  a  drop  of  ferroeyanid  solution,  produces  a  brown  tinge. 
The  burette  reading,  multiplied  by  0.003,  gives  the  amount  of  P2O5 
in  50  ec.  urine;  and  this,  multiplied  by  A-  the  amount  of  urine  passed 
in  24  hours,  gives  the  daily  elimmatiou.  jH 

To  determine  the  earihtj  phosphates,  a  sample  of  100  cc.  urine  ^" 
rendered  alkaline  with  NH^HO*  and  set  aside  for  12  hours.  The 
precipitate  is  then  eoHeeted  upon  a  filter,  washed  with  ammoniacal 
water,  brought  into  a  beaker,  dissolved  in  a  small  quantity  of  acetic 
acid;  the  solution  diluted  to  50  cc.  with  H2O,  tiTated  with  5  cc. 
sodhira  acetate  solution,  and  the  amount  of  P3O5  determined  as 
above. 

Metallic  Elements, — The  metallic  elements  of  urinai*y  salts  are 
sodium,  potassium,  calcium,  and  maguesiiim.  Sodium  and  potassiuro 
are  present,  not  only  in  combination  with  mineral  acids,  but  also  in 
organic  combination,  as  in  the  urates.  The  daily  elimination  is  eqaal 
to  2^3  gm.  K2O,  and  4-6  gm.  Xa-jO;  or  K:Na-'.  2.5:5.  Calcium  and 
maguesium  are  i^resent  principally  In  their  phosphates,  io  less  amonnt_ 
as  ehlorids,  and  occasionally  their  urates  are  met  with  in  calci] 
About  1  gra.  of  Ca  and  Mg  is  eliminated  in  24  hours,  in  the  prop 
tiou  of  2/3  JMg  and  1/3  Ca, 

NORMAL  ORGANIC   CONSTITUENTS  OF  THE   URINE, 

For  purposes  of  investigation  the  normal  organic  constituent*  of 
the  urine  may  l>e  convenient ly  divided  into  three  classes: 

(1)  Organic  coinpouuds  containing  nitrogen; 

(2)  Organic  compounds  con  tain  iug  sulfur;  and 

(3)  Organic  eompouuds  containing  neither  nitrogen  nor  sulfur* 
Nitrogenous  constituents  are  quite  numerous,  constitute  almost 

the  whole  of  the  urioary  solids,  and  differ  from  each  other  widely  in 
the  amounts  in  which  they  are  elimiuated.  In  this  class  are  included r 
urea,  ammonium  salts,  ammonium  carbamate,  creatinin,  uric  acid, 
xanthin  bases,  hippuric  acids,  oxaluric  acid,  allantoTu,  indox;! 
and  skafcoxyl  glucnrouates,  urochrom,  etc.,  eystin,  iodoxyl  and 
skatoxyl  sulfates,  tauroearbamic  acid,  ehondroi tin* sulfuric  acid,  osy- 
proteic  acid  and  alioxyproteic  acid,  of  which  the  last  six  also  coutain 
sulfur. 

Total  Nitrogen — Nitrogenous  Equilibrium — Nitrogen  Distribu* 


4 


IINE 


707 


tion. — The  ooruial  elimination  of  uitrogeu  with  ft  mixed  diet  is  from 
12  to  16  gms.  in  24  hours.  With  a  protein •  rich  diet  it  may  rise  to 
18,2,  while  with  a  diet  of  fats  and  carbohydrates  it  falls  from  about  11 
^ms.  to  as  low  as  2.S  gnis,  per  24  hours. 

Normally  the  elimination  of  nitrogen  by  the  urine  is  increased  by 
not  too  long  continued  ingestion  of  water  in  large  quantity;  during 
and  after  strenuous  muscular  exercise;  with  a  diet  excessively  nitroge- 
nous; and  after  ingestion  of  ammoniaeal  compounds;  and  it  is 
diminished  by  deficieocy  of  nitrogen  in  the  diet;  after  free  perspira- 
tion;  and  in  some  eases  of  normal  pregnancy  (see  Urea,  p.  711). 

Pathologically  it  is  increased  in  the  early  stages  of  all  acute  febrile 
diBeases,  except  when  these  are  attended  by  the  formation  of  dropsical 
deposits  or  by  diarrhoea;  during  reabsorption  of  dropsical  fluids;  in 
both  forms  of  diabetes;  and  in  chronic  interstitial  nephritis  (see  Urea, 
p.  711). 

For  the  determination  of  total  nitrogen  5  cc.  of  urine  are  placed 
in  a  long- necked  Kjeldahl  digesting  ilask  along  with  0.5  gm.  of 
CnSOi  and  15  cc.  of  eonceotrated  H38O4.  The  flask  is  supported  at 
45°  to  the  horizontal  and  gradually  heated  until  white  fumes  are 
given  off;  10  gm.  of  K!jS04  are  then  added,  and  the  contents  of  the 
flask  heat4id  just  short  of  boiling  until  almost  colorless.  After  cool- 
ing, the  contents  of  the  digesting  flask  are  transferred  and  washed 
into  a  distilling  flusk;  the  acid  is  nearly  neutralized  by  the  slow 
addition  of  NaHO  sobitiou  (sp,  gr.  1.24) ;  a  few  pieces  of  granulated 
SEinc  are  added,  and  then  a  moderate  excess  of  NaHO  solution,  where- 
upon the  flask  is  iui mediately  connected  with  a  bulb  tube  and  eon- 
denser,  so  arranged  as  to  deliver  the  distillate  into  a  recipient  con- 
taining HO  cc.  of  N,5  11^804  and  a  little  lacmoid  as  an  indicator.  The 
distillation  is  continued  until  about  2/3  of  the  liquid  have  passed 
over,  when  the  excess  of  112804  remaining  in  the  recipient  is  deter- 
mined by  titration  with  N/5  NaHO  solution.  Each  cc.  of  N/5  acid 
neutralized  by  the  aTumonia  formed  in  the  process  corresponds  to 
0.0028  gm.  of  nitrogen  in  the  5  cc.  of  urine  used.  A  blank  process 
must  be  conducted  with  reagents  alone  to  guard  against  error  from 
nitrogen  cons  pounds  in  the  reagents  or  in  the  air. 

An  animal  organism  is  said  to  be  in  a  condition  of  nitrogenous 
equiUbrium  when  the  quantity  of  nitrogen  taken  in  with  the  food 
equals  the  quantity  eliminated  in  the  urii^e  and  faeces  in  the  same 
period.  The  alisolute  qtiantity  of  nitrogen  for  this  condition  will  vary 
with  different  individuals,  and  with  the  same  individual  at  different 
times,  the  influencing  factors  being  chiefly  the  health  of  the  subject, 
the  mode  of  life,  and  the  composition  of  the  dietary.  In  an  individual 
receiving  a  diet  of  constant  composition  and  containing  suflicient 
nitrogen  for  the  purposes  of  nutrition  the  nitrogen  output  will  become 


708 


MANUAL    OF    CHEMISTRY 


coustaiit   in  from  two  to  four  days.     By  now  varymg  the  nitroge 
intake,  if  necessary,  to  equal  the  output,  and  maintaiuiag  other  cud 
ditions  as  nearly  at  equality  as  possible,  tlie  conditiou  of  equilibriur 
will  be  ultimately  reached,  it  being  remembered,  however,  that  there 
is  a  tendency  of   the  organism  to  adapt  the  nitrogen  output  to  the 
intake,  and  that  periods  of  24  hours  are  not  long  enough  for  eompar^H 
ison   during  variation  of   the  intake,  as  the  output  of  one  day  jH 
influenced  not  only  by  the  intake  of  that  day,  but  also  by  that  of  tbe 
preceding   day.     A   healthy   adult    man   can    maintain    nttrogenou 
equilibrium  under  usual  conditions  upou  a  diet  containing  0.6  gm. 
albumin  or  (as  proteins  contain  an  average  of  16  per  cent  of  N,  orj 
N^6.25  protein)  0J)1J6  gm.  of  nitrogen  per  kilo  of  hmly  weight 
diem.     This  is  the  lower  limit  of  nitrogenous  equilibrium  in  man,  for 
when  the  intake  is  less  than  this  equilibrium  is  no  longer  maiutaine 
and  the  output  becomes  greater  than  the  intake,  the  organism  disad 
similaliug  its  proper  tissues  to  supply  the  defieieney  of  supply. 

Tbe  study  of  the  distribution  of  urine  nitrogen,  or  the  nitrogcfl 
partition  of  the  uriue,  i.  e.,  tbe  relative  proportions  of  the  total  ni- 
trogen which  are  contained  in  tbe  individual  nitrogenous  constituents, 
has  ouly  become  possible  recently  for  a  few  of  those  constitiientj 
which  are  the  most  abundant,  by  the  invention  of  quantitative  pr 
cesses  of  snflicient  accuracy.  Those  constituents  which  may  now 
so  determined  are  urea,  ammonia,  uric  acid  and  creatinin;  tlil 
remainder  of  the  nitrogenous  constituents  must  still  be  classifled  uoder 
the  head  of  ^*uudetermined  nitrogen/*  lo  studying  the  distribution 
it  is  also  essential  that  the  absolute  amounts  of  the  several  substances 
be  taken  into  cousideratiou  as  well  as  their  relative  proportions,  for 
it  is  clear  that,  with  variations  in  the  relative  proportions  of  seveml™ 
substances,  the  absolute  amount  of  any  given  one  may  be  a  constaa^B 
or  a  variant,  and  moreover,  a  percentage  which  would  be  normal  fora 
given  value  of  total  nitrogen  would  not  be  normal  for  another.  Muchj 
work  is  now  being  done  iu  this  direction,  and  results  of  great  interysfel 
are  to  be  anticipated  from  iu%'estigatious  of  variations  in  nitrogenj 
partition,  not  only  of  normal,  but  also  of  abnormal  urinary  cuDstita' 
ents.  At  the  present  time  it  may  be  said  that  Folin  has  established  I 
tbe  basis  of  comparison  for  future  investigations  by  fixing  the  normal  I 
nitrogen  distribution,  and  the  influence  upon  it  of  the  composition  of  J 
the  dietary. 

In  a  aeries  of   investigations  with  six  normal  persons,  weigliiwf 
about  70  kg.  each,  receivi ug  a  -Vstaudard  diet,'*  containing  a  liberal 
rather  than  a  scanty  allowance  of  protein,  i.  e.,  119  gms.  proteia=H  I 
gms.  nitrogen  per  diem,  over  periods  of  five  days,  the  following  dis- j 
tributiou  of  nitrogen  was  found: 


for 
!]ei]^ 

sa^l 

gci^ 
ni- 
uts, 
mt^_ 
profl 

tyl 


UBINi! 


709 


Total 
nitrogen 

Ure* 
nitrogen 

AmmoniA 
nitrogen 

CreAtinin 
nitrogen 

Urio  Acid 
nitrogen 

Undeter- 
mined 
nitrogen 

ATerage 

Minimnm 

Maximum 

16.0 
14.8 
18.2 

13.9 
12.8 
16.2 

0.70 
0.55 
0.85 

0.58 
0.50 
0.66 

0.12 
0.08 
0.15 

0.60 
0.41 
0.85 

or  in  percentages  of  total  nitrogen : 


UreA 

AmmoniA 

AmmoniA 
+ureA 

CreAtinin 

Uric  Acid 

Undeter- 
mined 

Ayerage 

Minimum 

Maximum 

87.5 
86.2 
89.4 

4.3 
3.3 
5.0 

91.85 
90.70 
92.60 

3.6 
3.2 
4.5 

0.8 
0.6 
1.0 

3.75 
2.70 
5.30 

Another  series  of  determinations  with  four  persons  were  divided 
into  three  periods  of  feeding.  Daring  the  first  of  these  the  subjects 
received  the  same  food  as  in  the  above  experiments;  during  the 
second  the  diet  was  changed  to  a  ^^  starch -cream  diet/'  containing  only 
1  gm.  of  nitrogen  per  diem;  and  during  the  third  period  the  diet  of 
the  first  was  returned  to: 


Last  day  .  . 
First  day  .  . 
Seeond  day  . 
Third  day  . 
Fourth  day  . 
Rfthday.  . 
Sixth  day.  . 
BeTenth  day 
Eighth  day  . 
Ninth  day  . 
Tenth  day  . 
First  day  .   . 


TotAl 
nitrogen 


16.1 
10.6 
7.8 
6.5 
4.7 
5.1 
4.9 
3.9 
4.1 
4.2 
3.8 
9.8 


Ur«A 
nitrogen 


14.1 
8.9 
6.1 
4.8 
3.15 
3.5 
3.4 
2.3 
2.65 
2.7 
2.3 
7.3 


AmmoniA 
nitrogen 


0.50 
0.50 
0.46 
0.44 
0.47 
0.51 
0.50 
0.44 
0.43 
0.49 
0.52 
0.76 


CreAtinin 
nitrogen 


0.55 
0.51 
0.52 
0.50 
0.49 
0.56 
0.54 
0.54 
0.54 
0.60 
0.58 
0.60 


Uric  Acid 
nitrogen 


0.22 
0.17 
0.16 
0.12 
0.00 
0.11 
0.11 
0.11 
0.11 
0.11 
0.12 
0.18 


Undeter- 
mined 
nitrogen 


0.70 
0.46 
0.48 
0.64 
0.42 
0.40 
0.37 
0.49 
0.32 
0.43 
0.25 
0.91 


or  in  percentages  of  total  nitrogen: 

UreA 

AmmoniA 

AmmoniA 
+ureA 

90.7 
89.1 
84.9 
80.5 
77.6 
79.0 
79.2 
71.4 
76.0 
73.3 
74.8 
82.7 

CreAtinin 

Uric  Acid 

Undeter- 
mined 

Last  day 

First  day 

Seeond  day 

Third  day 

Fourth  day 

Rfth  day 

Sixth  day 

Seventh  day    .... 

Eighth  day 

mnth  day 

Tenth  day 

Wrst  day 

87.5 
84.4 
79.0 
73.5 
67.5 
69.0 
69.0 
60.0 
65.3 
61.8 
61.2 
74.9 

3.2 

4.7 

5.9 

6.8 

10.1 

10.0 

10.2 

11.4 

10.7 

11.5 

13.6 

7.8 

3.4 

5.0 

6.7 

7.7 

10.5 

11.0 

11.1 

14.0 

13.3 

14.0 

15.4 

6.1 

1.4 
1.6 
2.1 
1.9 
2.0 
2.1 
2.2 
2.8 
2.7 
2.6 
3.1 
1.9 

4.5 
4.3 
6.3 
9.9 
9.9 
7.9 
7.5 

12.8 
8.0 

10.1 
6.7 
9.3 

710 


MANUAL    OF    CHEMISTRY 


i 


The  results  in  the  four  cases  were  quite  concordant,  and  we  have 

given  the  results  of  the  last  day  of  the  first  period,  the  entire  second 
period,  and  the  first  day  of  the  last  period  in  one  case  only. 

Comparison  of  the  above  figures  shows  that  with  nitrogen  depriva* 
tion   urea  is  diminished   both    relatively  and   absolutely;     anmmni 
remains  nearly  constaut  absolutely,  bat  is  notably  increased  rehuivelj 
creatiuin  is  slightly  increased  absolutely  and  greatly  increased  i-eli 
lively;   uric  acid  is  diminished  absolutely,  but  iucreai!*ed  in  about  tli" 
same   ratio   relatively;    while   undetermined   nitrogen   is  diniiiuslied, 
absolutely,  but  increased  relatively,  with  notable  oscillations 

Folin,  in  interpreting  these  results  and  those  of  his  other  <ieteij 
miuatious,  reaches  the  following  conclusions: 

^*The  distribution  of  the  nitrogen  in  urine  among  urea  and   tl 
other  nitrogenous  constituents  depends  on  the  absolute  amount 
total  nitrogen  present, 

"The  absolute  quantity  of  creatinin  eliminated  in  the  urine  on  tt 
meat -free  diet  is  a  constant  quantity  different  for  different  individuals, 
but  wholly  independent  of  quantitative  changes  in  the  total  amount  of 
nitrogen  eliminated. 

'^Wheu  the  total  amount  of  protein- metabolism  isgi-eatly  reduced, 
the  absolute  quantity  of  uric  acid  is  diminished,  but  not  nearly  in 
proportion  to  the  diminution  in  the  total  nitrogen,  and  the  per  cent  of 
the  uric  acid  nitrogen  in  terms  of  the  total  niti-ogeu  is  therefore  much 
increased. 

■'With  pronounced  diminution  in  the  protein  metabolism  (asshov 
by  the  total  nitrogen  in  the  urine),  there  is  usually,  but  not  always 
and  therefore  not  necessarily,  a  decrease  in  the  absolute  quautity  of 
ammonia  eliminated.    A  pronounced  reduction  of  the  total  nitrogeu  ia,  „ 
however,  always  accompanied  by  a  relative  increase  in  the  ammoaiii-^B 
nitrogen,  provided  that  the  food  is  not  such  as  to  yield  an  alkaline 
ash. 

"The  absolute  quantity  of  undetermined  nitrogen  decreases  under 
the  influence  of  the  starch  and  cream  diet,  but  in  per  cent  of  tot 
nitrogen  there  is  always  an  increase. 

"  Urea  is  the  only  nitrogenous  substance  which  suffers  a  relative  i 
well  as  an  absolute  diminution  with  a  diminution  of  the  total  protein-" 
metabolisra." 

Ammonia. — ^It  is  believed  that  the  ammonia  which  is  eliminated  in 
the  urine  represents  that  fraction  of  the  product  of  protein  decoaiposi* 
tion  which  has  escaped  conversion  into  urea,  presumably  in  the  livd 
(p.  685).  One  cause  which  would  operate  to  prevent  such  conversion 
would  be  the  combination  of  ammonia  in  the  form  of  amuioninm  s"l-^ 
fate  or  phosphate,  which  are  not  convertible  into  carbonate,  as  are  tbe 
ammonium  salts  of  organic  acids.     With  a  deficient  nitrogen  iutake 


ucb 

I 


ider 

i 

teiB^ 

[in 
jsi-^J 

lonH 

»u      1 


URINE 


711 


the  elimination  of  ammonia  is  iioelianged  in  absolute  amount,  or  m 
sometimes  diminished,  while  its  relative  amount  is  increased.  With 
excessive  consumption  of  fats,  which  also  occurs  in  persons  with  a 
large  amount  of  adipose  during  starvation,  more  or  less  complete, 
there  is  marked  increase  in  tlie  elimioatiou  of  uriue  ammonia*  The 
ammoriia-couteut  of  the  urine  is  also  increased  by  interference  with 
the  aeration  of  the  blood,  and  it  is  supposed  that  in  such  cases  the 
ammonia  combines  with  the  excess  of  carbon  dioxid  iu  the  blood  (see 
also  Acetone,  p.  753). 

The  quantitative  determination  of  ammonia  in  the  urine  is  by  no 
Tueaos  the  simple  proposition  it  would  appear  to  be,  the  diflaeulty 
lying  in  the  tendency  of  other  nitrogenous  coustituents  to  undergo 
decomposition  with  formation  of  ammonia.  All  determinations  made 
with  the  older  processes  of  Sch losing,  and  Neucki  and  Zaleski,  have 
been  affected  with  a  plus  error  from  this  cause,  and  those  obtained  with 
tlie  more  recent  method  of  Shaffer  are  sometimes  similarly  vitiated. 

The  method  of  Polin  is  free  fmm  this  source  of  error,  as  neither 
CaH^O^  nor  BaH-iOs  is  usedr  To  25  ec.  of  the  urine,  8  to  10  gms.  of 
NaCl,  1  gm.  of  dry  Na2C03,  and  5  to  10  ec.  of  petroleum  »r  of  toluol 
(the  last  to  prevent  frothing)  are  added.  Through  the  mixture,  con- 
tained in  a  suitable  apparatus,  communicating  with  two  absorbing 
vessels  charged  with  a  measured  volume  of  N/10  acid,  a  current  of  air 
is  driven  at  room  temperature  for  one  and  a  half  hours,  at  the  rate  of 
about  600  to  700  liters  per  hour,  after  which  the  excess  of  aeid  is 
titrated  back  with  N/lO  alkali,  using  alizarin  red  as  an  indicator. 

Urea. — Under  usual  conditions  the  absolute  eliminatiou  of  urea  by 
a  healthy  man  of  about  70  kilos  is  from  30  to  35  gms.  in  twenty- four 
hours,  with  a  mixed  diet,  and  this  constitutes  from  86  to  90  per  cent  of 
the  total  nitrogen.  With  a  diet  containing  an  excessive  amount  of  pro- 
teiu  these  figures  may  become  still  greater.  With  a  diet  poor  in 
nitrogen,  both  the  absolute  and  relative  amounts  are  ditninished 
notably,  the  former  falling  during  six  days  from  19  to  3.5  gms.  in  24 
hours,  and  the  latter  from  84,5,  progressively  diminishing  to  60  per 
cent  of  the  total  nitrogen.  Under  usual  conditions  urea  is  therefore 
the  most  abundant  constituent  of  the  urine,  and  the  form  in  which 
most  of  its  nitrogen  is  excreted,  but  it  is  possible  that  under  conditions 
which  are  not  normal,  althougli  they  cannot  be  said  to  be  pathologicaU 
this  might  cease  to  be  the  case,  as  it  sometimes  does  under  pathological 
eonditions.  As,  with  a  continuance  of  low- nitrogen  diet,  or  on 
diminution  of  nitrogen  intake,  the  absolute  and  relative  amounts  of 
urea  progressively  diminish,  while  the  relative  amounts  of  ammonia 
and  creatiuin  both  increase,  it  is  conceivable  that,  if  the  system  can 
tolerate  a  further  reduction  of  protein  mpfn holism  below  that  reached 
in  the  experiments  reported,  as  iu  all  probability  it  may,  the  I'elative 


712 


MANUAL    OF    CHEMISTRY 


proportion  of  urea  may  fall  below  Miose  of  ammonia  and  of  creatinm. 
In    two   instances   at   least   this   lias   been    known  to  oeciir,  so  far 
as    ammonia    is   concerned,    in    pathological    nrines:     In    one   case 
14.7  per  cent  of  the  total  nitrogen  was  present  as  nrea,  and  40  ji^rj 
cent  as  ammonia.    In  the  second  case  4.4  per  cent  of  the  total  nitrogen  | 
was  in  nrea,  and  26.7  per  cent  in  ammonia. 

The  elimination  of  nrea.  like  that  of  all  constitnents  of  the  nritn\ 
normal   or   abnormal,  is  not  the   same  in  amonnt  during  all  equal 
fractions  of  the  twenty-four  hours.     The  miuiraum  elimination  is  in' 
the  early  mornintj  hours,  and  the  maximum  in  the  middle  of  the  alter- j 
nonn,  if  the  principal  meal  be  taken  at  noon. 

The  formation  of  urea  from  ammonium  carbonate  and  carbamate 
in  the  liver  has  been  referred  to  {p.  685).  Although  this  is  the  only 
origrin  of  urea  which  has  been  demonstrated,  it  is  certain  that  it  is 
neither  the  only  seat  nor  the  only  method  of  production  of  urea,  and 
if  is  proVjable  that  this  substance  is  formed  not  only  from  the  *Viren- 
latiiior  proteins/*  i.  e.,  those  contained  in  the  blood  and  lymph,  as  its] 
direct  dependence  npon  protein  intake  shows  it  to  be,  but  also  from 
the  ''tissue  proteins/'  i.  e.,  those  entering  into  the  composition  of  the 
cells.  Possibly  it  may  be  produced  in  part  as  a  side  product  in  the 
formation  of  creatinin,  or  of  some  of  the  several  other  substances  froraj 
which  the  '* undetermined  nitrogen'*  is  derived. 

The  view  formerly  entertained  that  uric  acid  constitutes  an  impor- 
tant intermediate  stage  in  the  formation  of  urea  in  the  system  has  been 
greatly  modified.    It  is  now  conceded  tliat  much  the  greater  proportions 
of  uric  acid  and  of  the  xanthiu  bases  are  produced^  in  mammalian  meta- j 
bolism,  from  the  nne!eoproteids,  as  products  of  processes  distinct  and' 
separate  from  that,  or  tliose,  by  which  nrea  is  produced. 

On  the  other  hand,  it  has  been  demonstrated,  l^y  experiments  with 
perfusion  of  sohitions  of  nrates  through  kidneys  and  Jivei-s,  and  with, 
the  aseptic  action  of  finely  hashed  "breis"  of  these  and  other  oi'ganal 
npon  the  same  salts,  that  nrea  tnay  be  produced  from  uric  acid  by 
these  organs.     It  w^as  found  that  the  livers  taken  from  digesting  ani- 
mals have  the  power  of  decomposing  uric  acid,  with  formation  of  nrea, 
but  that  those  of  fasting  animals  have  not.    It  was  also  found  that  the 
action  of  the  same  organ  taken  from  different  kinds  of  animals,  audj 
different  organs  from  the  same  animal,  differ  in  their  action  in  this! 
regard.     As  a  rule,  the  kidney  is  the  most  active  in  its  destruction  of  j 
nric  acid,  and  the  liver  next  in  activity.     The  livers  of  dogs  and  pigs^ 
decompose  uric  acid,  while  those  of  calves  produce  it.    The  two  kinds 
of  action  may  therefore  occur  in  the  same  organ,  one  or  the  other 
predominating  at  diffei-ent  times.    This  was  found  to  be  the  case  with 
horse  liver,  formation  predominating  at  fii'st,  destruction  later.    With 
human  kidneys,  taken  twelve  to  fifteen  hours  after  death,  92-98  per 


I 

;4 


UBIKE 


713 


cent  of  the  added  urates  were  destroyed.  Of  course,  in  these  experi- 
tneuts  bacterial  action  was  uot  excloded,  but  with  the  perfectly  fresh 
and  aseptic  kidneys  of  herbivora  80-98  per  cent  of  the  urates  were 
destroyed,  while  with  the  fresh  kidneys  of  dogs  only  14  to  19  per  cent. 
During  these  experiments  the  forr^ation  of  glyoxylic  acid  was  observed 
in  several  instances,  and  this  fact  led  to  the  suggestion  of  the  follow- 
ing explanation  of  the  mechanism  of  the  action:  The  nric  acid  is  first 
snpposed  to  yield  allautoin^  and  it  is  known  that  the  elimination  of 
allautoin  is  increased  in  cats  and  dogs  after  intravenous  injeetion  of 
urates.     The  allautoin  is  then  hydrolyscd  to  urea  and  glyoxylic  acid, 

.CO,NK 


according   to   the  equation:    HN' 


/" 


H-2H20=2H2N.- 


^CO.CH.NH.CO.NHi 
CO.NHi+CHO.COOIL     Glyoxylic  acid  and  urea  also  easily  condense 
to  allantoin  in  vitro,  by  the  reverse  reaction. 

By  what  method  the  large  proportion  of  ammonia  met  with  in  the 
urine,  with  a  protein -poor  diet,  is  protected  from  t^onversiou  into 
urea  is  not  known.  A  plausible  explanation  would  be  that  the 
ammonia  combines  with  sulfuric  or  phosphoric  acid,  prodneed  during 
increased  metabolism  of  tissue  proteinSt  by  oxidation  of  their  sulfur 
and  phosphorns,  to  form  salts  which  are  not  convertible  into  urea. 
But  this  view  finds  no  support  in  the  metabolism  experiments  above 
cited,  in  which  mineral  sulfates  and  phosphates  diminished  in  amount 
with  increasing  percentage  of  ammonia,  while  ester  sulfates  were 
increased  iu  proportion  to  both  mineral  sulfates  and  total  sulfur. 

Although  eountless  so-called  determinations  of  urea  have  been 
made,  very  little  is  known  of  the  actual  quantities  of  urea  present 
in  the  urine,  and  still  less  of  its  varying  relations  to  other  nitrogenous 
constituents,  and  to  the  total  nitrogen,  under  different  conditions  of 
health  and  disease,  because  almost  all  of  the  pmcesses  which  have 
beeii  used,  including  all  of  the  '' clinical"  processes,  lead  to  erroneous 
results.  Practically  the  whole  of  the  literature  upon  this  subject 
must  be  recast  in  the  light  of  new  investigations,  made  with  more 
accurate  methods. 

About  Quantitative  Processes. — ^It  would  appear  that  enough 
has  been  said  up  to  this  point  about  quantitative  methods  of  analysis 
of  urine,  and  of  their  results,  to  warrant  the  advice  to  the  praetieing 
physician  that  he  should  abstain  entirely  from  any  attempt  to  use 
them,  unless,  indeed,  he  may  spare  the  time  from  his  practice  to 
become  a  worker  in  a  chemical  laboratory.  The  perfection  of  methods 
has  involved,  as  a  necessity,  increases  in  their  complexity  and  time- 
consuming  power,  which  have  placed  them  entirely  beyond  the  reach 
of  the  busy  clinician.  And,  as  for  so-called  '* clinical  processes," 
which  waste  time  while  pretending  to  save  it  (for  any  time  spent  in 
acquiring  results  confessedly  inaccurate  must  be  counted  as  wasted) » 


i^Cn 


714  MANUAL    OF     CHEMISTRY 

iDcdical  literature  is  loaded  down  with  their  product — a  worse  thau 
worthless  mass  of  rubbish. 

Let  the  medical  praetiliouer  confine  his  activities  in  ^* urinalysis" 
to  qualitative  examinations  for  abnormal  constituents,  which  are  for 
the  most  part  entirely  within  his  capacity;  but  where  quantitative 
determinations  are  required  for  any  purpose,  let  them  be  made  by  an 
expert,  competent  to  judge  of  the  reliability  of  methods,  and  abreast 
of  the  time  in  their  perfection.  In  this  matter  the  general  practitioner 
stands  as  much  in  need  of  the  aid  of  a  specialist,  as  he  does  of  that 
of  a  skilful  surgeon  for  a  delicate  operation .  And  in  this  connection 
it  should  also  be  said  that  the  value  of  sugh  investigations  frequently 
depends  upon  comparisons  of  intake  with  output,  and  that  in  such 
<5ases  the  enquiry  should  not  be  entered  upon  unless  the  patient  is 
willing  to  undergo  the  personal  discomfort  of  a  regulated  and  meas- 
ured diet.  Further,  in  such  cases  the  faeces  should  also  b^  submitted 
to  analysis.  In  order  that  comparable  quantitative  results  may  be 
obtained  at  all,  the  following  precautions  are  essential  in 

The  Collection  of  Samples. — (1)  The  urine  should  be  collected 
without  admixture  of  any  other  solid  or  liquid  substance  whatever, 
except  that,  in  hot  weather,  two  or  three  drops  of  formalin  may  be 
placed  in  the  bottle  to  prevent  decomposition. 

(2)  It  should  be  placed,  immediately  after  having  been  voided,  in 
a  perfectly  clean  bottle  or  bottles.  A  half -gallon  so-called  mineral 
water  bottle  (Poland,  etc.)  is  of  sufficient  capacity  usually,  and  serves 
very  well,  as  its  original  contents  consisted  of  quite  pure  water. 

(3)  This  receiver  must  be  kept  corked  and  cool,  or  preferably  cold. 
If  this  precaution  be  neglected  quantitative  determinations  of  ammonia 
and  of  urea  cannot  be  accurately  made. 

(4)  The  sample  must  be  the  entire  urine  of  twenty-four  hours. 
No  quantitative  determiyiation  viade  with  a  sample  not  taken  from  the 
mixed  and  measured  urine  of  twenty  -four  hours  is  of  any  value  what- 
ever. The  bladder  is  to  be  emptied  when  the  collection  begins,  con- 
veniently at  8  A.M.,  and  this  urine  thrown  away.  All  urine  passed 
duriiip:  the  following  twenty-four  hours,  including  that  obtained  by 
emptying  the  bladder  at  8  a.m.  the  next  day,  is  to  be  collected. 

For  qualitative  testing  a  sample  may  be  taken  at  any  time,  and  in 
any  quantity,  so  it  be  sufficient.  But  as  there  are  hourly  variations 
in  tlie  elimination  of  all  abnormal  constituents,  sometimes  extending 
to  complete  disappearance,  it  is  preferable  to  examine  two  samples, 
one  taken  in  the  morning,  when  the  elimination  is  at  the  minimum, 
and  the  other  at  about  three  to  four  hours  after  the  principal  meal, 
for  the  maximum. 

Quantitative  Determination  of  Urea. —  Folin^s  Method,— ThU 
method  is  based  upon  the  decomposition  of  urea  at  150°  into  ammonia 


URINE 


715 


and  eyamiric  acid  (p. 404  ),  and  the  deeompositioti  of  cyauiine  acid 
by  boiling  alkaline  soliUions  into  aniiiionra  and  c^irbou  diuxld  (p,  31>G). 
Urea  is  calenlated  from  the  animonia  produced.  To  ctMiiUiut  I  he  pro- 
cess  3  cc.  of  urine  are  placed  in  200  ce,  Erlennieyer  llitsk  with  2  w. 
of  concentrated  HCl  (sp.  gi\  1J4},  and  20  gms.  of  unstallizi'd  Msrt'I- 
(the  b.  p.  of  wliieh  is  abont  160"),  a  snmll  |nece  of  pi*ntflhj  is  added 
to  prevent  frothing;  and  tiie  flask  is  fitted  with  a  return  condenser, 
having  three  bulbs.  The  contents  of  the  flask  are  heated  to  active 
boiling  fur  about  ten  minutes,  to  expel  the  exfiess  of  water  (whieh  is 
recognized  by  drops  from  the  condenser  produeing  a  hissing  sound  on 
falling  baek).  The  heat  is  then  rednced  to  moderate  boiling,  which 
is  continued  for  forty-five  to  sixty  minutes.  Water  is  then  cautiously 
added  to  the  still  hot  e<t!i tents  of  the  flask,  at  fii'st  guttatim,  which 
are  then  transferred  to  a  1000  ec,  tiask,  and  diluted  to  500  cc.  with 
water.  After  addition  of  a  little  talciim  powder  and  7  to  8  cc.  of  20 
per  cent  NaHO  sc^lution,  the  ammonia  is  distilled  <^ff  into  N/10  aeid, 
the  distillation  being  continued  tVir  sixty  to  seventy  minutes,  after 
whieh  the  CO2  wliieh  has  coHeeted  in  the  acid  is  boiled  out,  and  the 
NH3  determined  by  titration  as  usual.  It  is  essential  to  the  aeeuraey 
of  the  results  that  during  the  heating  an  excess  of  aeid  be  present,  for 
whieh  reason  the  condenser  cannot  be  dispensed  with,  and  that  the 
heating  and  distillation  be  continued  for  the  periods  mentioned,  to 
insure  complete  decomposition.  Two  corrections  are  required.  Com- 
mercial MgCb  always  contains  NH:i.  Its  tenure  in  this  for  20  gms* 
must  be  determined  and  subtracted  from  the  result.  A  separate 
determination  of  the  ammonia  in  the  urine  must  be  made,  and  the 
number  of  cc.  of  N/lO  NHn  for  3  cc.  corresponding  thereto  must  also 
be  subtracted*  After  tliese  corrections  have  been  made  each  cc.  of 
N/10  NH3  represents  0.1002  urea  in  100  ce.  No  ammonia  is  given  off 
in  this  process  from  uric  acid,  hippuric  acid,  creatinin,  creatin  or 
amido  acids.  The  results  are  therefore  accurate  with  proper  manip* 
ulation.  A  suitably  adjusted  electric  heater  is  very  convenient,  and 
with  it  the  process  may  be  conducted  with  little  more  attention  than 
is  required  for  an  ordinary  Kjeldahl.  This  process  is  recommended 
as  the  best  yet  devised,  and  it  is  difficult  to  see  in  what  direction  it 
can  I>e  improved  upon,  unless  there  be  found  to  be  some  slight  error 
due  to  components  of  the  ^Umdetermined  nitrogen."  In  place  of 
applying  tlie  process  directly  to  the  urine,  it  may  be  applied  to  the  fil- 
trates froin  the  Morner-Sjoqvist  or  Ptliiger-Gumlich  methods. 

Momer-ISjoqvlst  Mefhoff. — This  method  is  based  upon  the  fact  that 
urea  is  not  precipitated  from  its  aqueous  solution  containing  BaCb 
and  BaH2<>2  by  alcohol -*^ther,  whereas  the  other  nitrogenous  con- 
stituents are  so  precipitated,  exrepf  ammonia,  hippuric  acid,  creatinin 
and   traces  of  allantoTu,     To  conduct  the  process:    To  5  cc.  of  the 


716 


MANTAL    OF    CHEMISTRY 


urine  in  a  flask  add  5  cc,  of  a  saturated  solution  of  BaCb,  containing 
5  per  cent  of  BaH202.  oud  100  cr.  uf  a  mixture  of  two  parts  of  97  per 
cent  alcohol  and  one  part  of  etliei%  and  allow  the  mixtnre  to  stand  in 
a  closed  flask  for  twelve  hours.  The  liquid  is  then  filtered  off,  the 
preeipitate  washed  with  alcohol -ether,  and  the  filtrate  and  washingJi 
distilled  at  about  55^  (not  above  60°).  When  the  liquid  has  been 
reduced  to  about  25  ec,  a  little  water  and  some  M^  are  added, 
and  the  evaporation  continued  until  the  liquid  is  reduced  to  10  to 
15  cc.  The  liquid  is  then  transferred  to  a  Kjeldahl  flask  with  a  little 
water,  concentrated  over  the  water* bath,  and  in  it  the  ammonia  is 
determined  by  the  Kjeldahl  Tnethod.    - 

Pfluger-Gumiich  Mfihod — ^differs  from  the  preceding  in  that  the 
nitrogenous  constituents  other  than  urea  are  precipitated  out  by 
phosphotnngstic  acid,  and  the  nitrogen  is  determined  in  the  filtrate 
by  the  Kjeldahl  method.  The  Folin  process  is  to  be  preferred  to 
either  the  Moruer-Sjoqvist  or  Pfliiger-Gumlich. 

The  least  objectionable  of  the  clinical  processes  will  now  he  re- 
ferred to,  although,  from  what  has  been  said 
above,  it  is  clear  that  their  use  is  not  reconi- 
rnended: 

Probably  the  most  satisfactory  process  in  tbe 
hands  of  t!ie  practitioner  is  that  of  Hiifner,  based 
upon  the  reaction,  to  which  attention  was  first 
called  by  Knop,  of  the  alkaline  bypobromiies 
upon  urea  (p.  4t)4),  using,  however,  Dietrich's 
apparatus,  or  the  more  simple  modification  sug- 
gested by  Kumpf ,  in  place  of  that  of  Hiifner* 
Th«^  apparatus  (Fig.  44)  consists  of  a  burette  of 
3()-50  ec.  capacity,  immersed  in  a  tall  glass 
cylinder  filled  with  water,  and  supported  in  such 
a  way  as  to  admit  of  being  raised  or  lowered  nt 
pleasure.  The  upper  end  of  the  burette  com- 
municates with  the  evolution  bottle  a,  which 
has  a  capacity  of  75  cc,  by  means  of  a  rubber 
tube. 

The  reagent  required  is  made  as  folio wf:  27 
ce.  of  a  solution  of  caustic  soda,  made  by  dis- 
solving 100  grams  NaHO  in  250  cc.  11^0,  are 
brought  into  a  stoppered,  graduated  cylinder, 
2.5  cc.  bromin  nve  added,  the  mixture  shaken, 
and  diluted  with  water  to  150  cc.  The  caustic 
soda  solution  nmy  be  kept  in  a  bottle  having  a 
rubber  stopper,  hut  the  mixture  must  be  made  up 
Fi9.  44,  as  required,  a  fact  which,  owing  to  the  ir-itacing 


I 


I 


4 


UEINE 


71T 


character  of  the  bromin  vapor,  renders  the  use  of  this  reageut  in  a 
physiciau's  office  somewhat  troublesome.  The  bromiu  is  best  meas- 
ured by  a  pipette  of  suitable  size,  having  a  coinpressible  rubber 
ball  at  the  upper  eud. 

To  couduet  a  determination,  about  20  ce,  of  the  hypobrouiite 
tjoltitiou  are  placed  in  the  bottle  aj  5  ce.  of  the  urine  to  be  exaiuitied 
are  placed  iu  tht?  short  test-tube,  which  is  then  iutroduuttd  into  tlie 
position  showu  iu  the  figure,  care  being  had  that  no  urioe  escapes. 
The  cork,  with  its  fittings,  is  then  introduced,  the  pincheoek  h  opcnedt 
and  closed  again  when  the  level  of  the  ^iquid  iu  the  burette  is  the 
same  as  that  in  the  eylinder.  The  deeomij:jsiug  vessel  a  is  then  in- 
clined so  that  the  urine  and  hypobrcinite  solution  mix;  the  decom- 
position begins  at  once,  and  the  evolved  N  passes  into  tbe  burette, 
which  is  raised  from  time  to  time,  so  as  to  keep  the  external  and 
internal  levels  of  water  about  equal;  the  CO2  fonned  is  retained 
by  the  soda  solution,  Iu  about  half  an  hour  (the  de(*oni position  is 
usually  complete  in  ten  minutes,  but  it  is  well  to  wait  half  an  hour) 
the  height  is  so  adjusted  that  the  inner  and  outer  levels  of  water  are 
exactly  even,  and  the  graduation  is  read,  while  the  standing  nt  the 
barometer  and  thermometer  are  noted  at  the  same  time. 

In  calculating  the  percentage  of  urea  from  the  volume  of  N 
obtained,  it  is  essential  that  a  correction  shonld  be  nuide  tor  differences 
of  tempeniture  and  pressure,  without  which  the  result  froTii  an  ordi- 
nary sample  of  urine  may  be  vitiated  by  an  error  of  10  per  cent.  It*, 
however,  tlie  temperatnre  and  bammetric  pressure  have  been  noted, 
the  correetiou  is  readily  made  by  the  use  of  the  table  (see  Appendix 
B,  III),  eoniputed  by  Dietrich,  giving  the  weight  of  1  cc,  N  at  differ- 
ent temperatures  and  pressures. 

In  tiie  square  of  the  table  in  whic!h  the  horizontal  line  of  the 
observed  temperature  crosses  the  vertical  line  of  the  observed  baro- 
metric pressure  will  be  found  the  weight,  in  milligrams,  of  a  ce» 
of  N;  this,  multiplied  by  the  observed  volume  of  N,  gives  the  weight 
of  N  produeed  by  the  decomposition  of  the  urea  contained  in  5  cc. 
urine.  But  as  60  parts  urea  yield  28  parts  N,  the  weight  of  N, 
multiplied  by  2.143,  gives  the  weight  of  urea  in  milligrams  in  5ec, 
urine,  Tliis  quantity,  multiplied  by  twice  the  amount  of  urine  in  24 
hours,  and  divided  by  10,LKX),  gives  the  amount  of  urea  eliminated 
in  24  liours  in  grams.  If  the  result  be  desired  in  grains  the  amount 
in  grams  is  multiplied  by  15.432. 

Example, —Five  cc.  urine  decomposed;  barometer  =^736  mm,; 
thennometer  =^  10°  ;  burette  reading  before  decomposition  =  64.2; 
•ttme  after  decomposition  =  32.6;  ec.  N  collected —  31.6.  From  the 
table  1  PC  N  at  lO*"  and  736  mm.  BP  weighs  1 J593.  The  patient 
Dasses  1500  cc.  urine  in  24  hours  : 


718 


MANUAL    OF    CHEMISTRY 


31.6  X  M593  =  36.6339  =  mi11igr-  N  in  5  cc.  urine. 
36.6339  X  2.U  =  78.3965=  milligr.  urea  in  5  cc.  nnne. 

78.3965  X  3000      ^o  ^m  •     *>*  u 

f7r7„7n —  23.519  =  grains  tiroa  )n  24  hours. 

23.519  X  15.432  —  362.94  =  grains  urea  in  24  hours. 

In  using  this  process  it  is  well  to  have  the  urea  solution  as  near 
the  strength  of  one  per  cent  as  possible;    therefore  if  the  urine  be 
concentrated,  it  should  be  dihited.     Even  wben  carefully  conducted 
the  process  is  not  accurate;   creatiuiii  and  uric  acid  are  also  decom 
posed  with  liberation  of  N»  thus  causing  a  plus  error;   on  the  other 
hand^  a  minus  error  is  caused  by  the  fact  that  in  the  decomposition  of 
urea  by  the    hypolu-omite,  the  theoretical    result   is  never  obtained 
within  about  eiifht  per  cent  in  urine.    These  errors  may  be  rectified  ti 
some  extent  by  multiplying  the  result  by  1,044, 

A  process  which  does  not  yield  as  accurate  results  as  the  pre 
ceding,  but  which  is  more  easy  of  application,  is  that  of  Fowler, 
based  upon  the  loss  of  sp,  gr.  of  the  urine  after  the  decomposition  of 
its  urea  by  hypochlorite.  To  apply  this  method  the  sp.  gr.  of  the 
urine  is  carefully  determined,  as  well  as  that  of  the  liq.  soda?  chlo* 
rinatfe  (Squibb's).  One  volume  of  the  uriue  is  then  mixed  with 
exactly  seven  volumes  of  the  liq,  sod,  chlor.,  and,  after  the  first  vio- 
lence of  the  reaction  has  subsided,  the  mixture  is  shaken  from  time 
to  time  during  an  hour,  when  the  decomposition  is  complete;  the  sp. 
gr.  of  the  mixture  is  then  determined.  As  the  reaction  begins 
instantaneously  when  the  urine  and  reagent  are  mixed,  the  sp.  gr.  ot 
the  mixture  must  be  calculated  by  adding  together  once  the  sp.  gr.  of 
the  urine  and  seveu  times  the  sp,  gr,  of  the  liq.  sod.  chlor.,  and  divid- 
ing the  sum  by  8,  From  the  quotient  so  obtained  the  sp,  gr.  of  the 
mixture  after  decomposition  is  subtracted;  every  degree  of  loss  in 
sp.  gr.  indicates  0.7791  gram  of  urea  in  100  cc.  of  urine.  The  sp. 
gr.  determinations  must  all  be  made  at  the  same  temperature;  and 
that  of  the  mixture  only  when  the  evDlutinn  of  gas  has  ceased 
entirely, 

Creatinin  (p.  389) — is  the  lactam  of  creatin,  or  methyl -guanidia 
acetic  acid,  from  which  it  is  derived  in  the  body  by  dehydration: 

^^'K^i^S'-(^^^^-^'^=^^'K  /cU,  and  exists  in  the  blood 

^-^^3  N-CH3 

and  urine  of  adults,  and  in  traces  iu  milk,  although  it  is  absent  in  the 
urine  of  nursing  infants.  The  quantity  eliminated  is  from  three  ti* 
six  times  that  of  uric  acid^  1.2  to  2.1  in  twenty -four  hours.  The 
amount  eliminated  by  a  given  individual  is  remarkably  constant,  and 
averages  6  per  cent  of  the  total  nitrogen.  With  diminution  of  protein 
metabolism  there  is  very  little  change  in  the  absolute  elimination  of, 


0 

r 
f 
d 

I 


tlNE 


719 


creatinin,  and  therefore,  by  deiniiiition  of  urea  elitniuatiou,  the  rela- 
tive value  of  the  creatiuiii  nitrofi:e!i  itK.Teases  so  that,  from  furnishing 
ouly  3.4  percent  of  the  total  nitrogen,  it  eomes  to  furnish  over  17  per 
cent.  Although  constant  for  a  given  individual,  the  ahsolutecretttinin 
elimination  varies  with  different  persons,  and  seems  to  hear  a  relatiou 
tit  the  body  weight  and  to  the  degree  of  corpulence,  in  sucli  manner 
that  fat  persons  eliminate  about  20  mgrn.  per  kilo  of  body  weight,  and 
lean  persons  about  25  mgm,  per  ktlo. 

Oreatiniu  seems,  therefore,  to  be  a  product  of  tissue  protein  met- 
abolism essentially  (See  Uric  Acid,  p,  721).  Creatin  is  certainly  pro- 
duced iu  muscular  tissue,  and  is  dehydrated  to  creatinin  in  the  system, 
and  the  elimination  of  the  lattfer  is  increased  with  active  muscular 
effort.  In  diseases  attended  with  increased  muscular  activity  there  is 
both  increase  iu  the  absolute  elimination  of  creatinin,  and  increase  in 
the  percentage  of  its  nitrogen  in  the  total  nitrogen.  In  rapid  muscu- 
lar atrophy,  however,  the  creatinin  elimination  remains  normal,  or  is 
slightly  increased.  In  convalescence  after  illness  of  long  duration  the 
elimination  of  creatinin  is  greater  with  a  meat  diet  than  with  other 
diets. 

Formerly  the  only  available  method  of  quantitative  determination 
of  creatinin  was  a  laborious  process  in  which  it  was  separated  as  its 
L-rystalline  compound  with  ZnCl^,  and  its  quantity  calculated  frruu 
that  of  the  zinc  oxid  obtained  therefrom.  The  colorimdric  procfsa  of 
Fofhi  is  more  accurate,  and  is  rapidly  conducted.  It  dept^nds  nixm 
Jaffe's  reaction,  which  consists  of  the  formation  of  an  intense  red 
color  when  picric  acid  and  a  few  drops  of  KHO  or  NallO  solution  are 
added  to  a  solution  of  creatinin,  which  becomes  an  orange  color, 
similar  to  that  of  potassinm  diehromate  solution,  on  dilution.  The 
only  other  substances  which  may  be  present  in  the  urine  wiiich  give 
a  similar  color  are  acetone  and  acetoacetic  acid  and  ester,  which  are 
pathological  products 4  easily  removable.  The  comparison  solution  is 
a  N/12  solution  of  Ki;Cr207,  containing  24.54  gms.  per  liter.  One  tube 
of  a  colorimeter  capable  of  adjustment  to  0.1  mm.  is  tilled  to  the 
depth  of  exactly  8  mm.  with  this  solution.  For  comparison,  10  ec.  of 
the  urine  are  placed  in  a  500  re.  mensnring  flask,  15  cc.  of  a  1,2  per 
cent  aqueous  solution  of  picric  aci*l,  and  5  ec.  of  a  10  per  cent  NnllO 
solution  are  added,  the  mixture  shaken  and  allowed  to  stand  five 
minutes,  after  which  it  is  diluted  with  water  to  500  cc,  and  wadi 
mixed.  The  second  tube  of  the  colorimeter  is  rinsed  out  with  Hi  is 
liqnid,  which  is  tlien  run  into  the  second  tube  to  eolorimetric  equality 
with  the  first  tube.  Some  previous  practice  with  the  dichromate  solu- 
tion in  both  tubes  is  necessary  to  train  the  eye  to  perception  i»f  equality 
of  tirjt.  The  mean  of  three  or  four  readings  is  tnken,  and  with  this 
the  creatinin  content  in  mgras.  per  10  cc.  of  urine  is  calculated  by  the 


720 


MA^JUAL    OF    CHEMISTBV 


8  1 
formula  — -XIO,  iu  which  x  is  the  reading  of  the  colorimeter.    FoFj 

example,  if  the  mean  of  the  readiogfs  be  7.2,  then  ^^X  10=11,25 

mgms.  ereatiniu  iu  10  cc,  urine.  If  the  colorimetric  value  be  less 
than  5  mm,  the  deteruiiuation  is  to  be  repeated,  using  5  cc,  of  urine 
in  place  of  10;  and  if  the  value  be  greater  than  13  mm.,  with  20  c«, 
of  urine  in  place  of  10. 

The  question  whether  the  urine  contains  creatin  as  well  as  crea- 
tinine previously  unanswerable,  was  solved  by  this  process.  It  was 
found  that,  by  heating  5  to  10  mgras.  of  creatin  with  10  cc.  HgO  and 
5  cc.  normal  IICI  on  tbe  water -bath  for  three  hours,  the  creatin  was 
quantitatively  converted  into  creatiuin.  Therefore,  by  making  two 
determinatioDs  by  the  above  method,  one  with  the  urine  dii-ectly,  the-* 
second  with  the  urine  after  four  iiours'  heating  under  the  above  con- 
ditions, any  creatin  present  would  cause  a  higher  value  of  the  second 
determination,  and  the  quantity  of  creatin  may  be  determined  from 
the  difference  between  the  two  readings:  1  ragm,  creatinine  1.16  mgm. 
creatin.  It  was  found  that  creatin  is  neither  constantly  present  nor 
constantly  absent,  that  some  samples  contain  no  creatin,  and  tbat  iu 
others  its  amount  may  rise  as  high  as  I.IG  mgm,  in  10  cc.  for  19.8  of 
creatiuin  also  present.  It  was  found  also  that  in  some  urines  a  small 
fraction  of  creatiuin  is  converted  into  creatin  when  the  urine  is  al- 
lowed to  stand  for  some  days  aseptically. 

Uric  Acid  (p.  528) — is  present  in  the  urine  of  man  and  of  the 
carnivora,  and  is  particularly  abundant  in  the  solid  urine  of  birds 
and  reptiles,  which  consists  almost  entirely  of  ammonium  urate.  Id 
the  urine  of  the  herbivora  it  exists  only  in  traces,  being  replaced  by 
hippuric  acid. 

We  have  seen  (p*  733)  that  the  former  consideration  of  uric  acid 
as  an  important  intermediate  substance  in  the  formation  of  urea  in 
mammals  is  no  longer  entertained.  In  reptiles  nitrogen  is  almost 
exclusively  eliminated  as  uric  acid,  and,  as  metabolism  is  extremely 
slow  in  these  animals,  this  was  held  as  strong  argument  in  favor  of 
the  view  that  uric  acid  is  a  lower  condition  of  oxidation  of  proteins,  in 
tbe  line  of  urea  formation.  But  the  force  of  this  argument  is  lost  in 
the  light  of  the  fact  that  in  birds,  in  which  metabolism  is  very  rapid^ 
the  greater  part  of  the  nitrogen  is  also  eliminated  as  uric  acid*  In 
reptiles  and  birds,  therefore,  uric  acid  cannot  have  that  subordinate 
interest  in  the  metabolism  of  proteins,  other  than  nucleoproteids,  that 
it  is  believed  to  have  in  mammals.  It  is  true  that  both  reptiles  and 
birds  excrete  urea,  but  it  is  in  such  small  amount  that  in  general 
protein  metabolism  in  these  animals  it  occupies  a  position  subordinate 
to  uric  acid.  It  has  been  observed  that  the  same  causes  which  produce 
increased  urea  eiimiuatiou  iu  mammals,  such  as^the  administratiou  of 


4 


i 


URINE 


721 


iim  corapounds,  eaiist3  inrrea.sed  uric  add  elimination  in  birds. 

ic  acid  formation  in  birds  depends  npon  an  action  of  tin:?  livar 
is  shown  by  the  fact  that  geese,  whit*h  normally  elinnnate  about  GO 
to  70  per  cent  of  the  total  nitrogen  n?  uric  acid»  this  percentage*  falls 
to  3  or  4  per  cent  after  extirpation  of  the  liver,  an  operation  which 
these  animals  sur%uve  for  ubont  twenty  iiours.  It  may  be  supposed, 
therefore,  that  in  birds  nric  acid  may  be  formed  in  the  liver  from 
urea,  or  suitable  aminoniuui  compounds,  by  a  so-called  synthesis 
eimiiar  to  that  by  which  urea  is  formed  in  mammals  from  the  same 
materials  (p.  685).  Indeed,  it  has  been  demonstrated  that  nric  acid 
is  formed  from  amnion n*  and  lactic  acid  in  the  livers  of  birds,  aud 
lactic  acid,  known  to  be  produced  quite  constantly  in  animal  or*jan- 
isms,  may  have  its  origrin  in  deamidation  of  alauin:  CiI:j.CHNH2.- 
€OOH+M20=CHa.CHOH.COOH+NH3.  It  is  quite  possible  that 
both  princesses  take  place  in  the  livers  of  botli  birds  and  mammals, 
the  formation  of  nric  acid  predominatiug  largely  iu  the  former,  and 
that  of  urea  iu  the  latter. 

That  the  predomiuating  origin  of  uric  acid  and  of  the  xanthin 
bases  in  mammals  is  from  the  pur  in  bases  of  the  uucleoproteids  is, 
however,  now  conceded*  Administration  of  nucleoproteids  or  of  purin 
bases  is  followed  by  increased  uric  acid  elimination,  as  is  also  the 
addition  of  food  rich  in  pnrin  bases,  such  as  meat,  liver,  thymus,  et<j., 
to  a  fixed  diet.  In  lenka^mia,  in  which  there  is  extensive  destruction 
of  the  puriu-rieh  leucocytes,  the  elimination  of  uric  acid  is  above  the 
uormaL  With  a  diet  from  wliich  purin  bases  are  entirely  excluded 
the  elimination  of  uric  acid  is  greatly  diminished,  but  never  to  com- 
plete extinction.  There  is  therefore  an  "endogenous"  origin  of  uric 
acid,  i*  e.,  from  the  tissue  proteins,  as  well  as  an  "exogenous"  origin, 
i.  e.,  from  the  circulating  proteins.  The  quantity  of  exogenous  nric 
acid  eliminated  varies,  of  course,  with  the  purin  content  of  the  food; 
that  of  the  endogenous  uric  acid,  although  varying  with  different 
individuals,  is  quite  constant  with  the  same  individual,  wlien  the  diet, 
although  purin* free,  contaius  a  snfflcient  supply  of  protein.  The 
daily  elimination  of  eudogenons  uric  acid  under  these  conditions 
varies  with  dififerent  individuals  from  0.3  to  0.6  gm.  But  with  a  diet 
which  is  both  purin -free  and  also  nitrogen -poor,  the  elimination  of 
endogenous  uric  acid  is  markedly  diminished  as  the  total  uitrogen 
elimination  is  reduced,  l>nt  not  proportir>nately  to  such  reductiou. 
Thus  in  a  normal  individual  eliminating  0.55,  0,53,  and  0,53  gm,  of 
uric  acid,  with  13,4,  13.0,  and  16,8  gms,  of  total  urine  nitrogen  in 
three  consecutive  days  upon  a  purin -free  and  nitrogen -suflicient  (19 
gm.  N  in  twenty -ft>ur  hours)  diet,  the  elimination  fell  to  0.34,  0/29, 
0,32,  0.26  0.28,  and  0.26  in  six  days,  with  7.5,  6.7,  4.4,  5.3,  4.8,  and 
3,6  of  total  uitrogen,  upon  a  diet  containing  but  1  gm.  nitrogen  per 
46 


t22 


MANUAL    OF    CHEMISTRY 


tliern.  Under  these  circorastauces  there  is  oot  the  same  defifree  of  eoii- 
8taucy  of  elimination  as  in  the  ease  of  ereatiniu  (p.  719).  The 
endogeDous  uric  aeid  represents  the  extent  of  cell  work  of  the  iiidi-j 
vidual,  to  which  is  added  the  exogenous  uric  aeid,  varying  in  amount 
with  the  degree  of  richness  of  the  food  in  xanthin  bases.  It  is  not  to 
be  inferred  that  the  portions  of  substance  derived  from  these  two  originfl 
are  kept  distinct  in  their  transit  towards  excretion,  but  rather  that: 
there  exists  a  dynamic  equilibrium  between  them,  as  between  a  HquidJ 
and  its  saturated  vapor  {p, 30) ,  and  that  that  which  is  exogcDous  materia 
at  one  instant  may  become  endogenous  the  next,  and  vice  vf^rsa. 

From  what  has  been  said  in  that  connection  in  discussing  urea,  it| 
appears  to  be  certain  that  not  all  of  the  uric  acid  which  is  formed  inl 
the  economy  is  eliminated  by  the  kidneys.  A  portion  is  destroyed  in  the' 
system,  and  that  which  is  eliminated  is  merely  the  residuum  which  ha» 
escaped  conversion.  This  is  further  proven  by  experiments  upoa 
rabbits,  by  which  it  was  shown  that  only  18  per  cent,  or  less,  of  uric 
acid,  dissolved  by  piperazin,  injected  into  the  circulation  could  he 
recovered  in  the  urine;  and  the  fraction  was  still  smaller  when  the 
administration  was  by  the  mouthy  possibly  because  of  destruction  in^ 
the  liver. 

With  a  sufficient^  purin-free,  mixed  diet  the  daily  eliminntifm 
uric  acid  by  a  healthy  man  is  from  0.3  to  0.6  gm* ;    with  a  purin-rici 
diet  it  may  rise  to  1.5  or  2.0  gms.;   and  with  a  uitrogen-poor  diet  i^ 
may  fall  as  low  as  0,22  gm.     In  relation  to  total  nitrogen  its  nitrogen 
may  be  0.7  to  1.4  per  cent  of  the  total  with  a  mixed  diet,  and  0.8 
4.0  with  one  which  is  nitrogen -poor. 

The  results  of  quantitative  determinations  in  pathological  coudi- 
titms  are   somewhat   conflicting,  and   those   obtained    by   the   older 
methods  are  for  the  most  part  errooeous,  being  affected  with  a  minus, 
error.     The  following  facts  may,  however,  be  considered  as  estab- 
lished:  In  leukaemia  there  is  both  absolute  and  relative  increase,  the 
absolute  amount  being  from  1  to  5  gm.  in  24  hour«,  and  the  pro- 
portion to  urea  increased  to  1:45  to  1:12.     A  similar  increase  ocourfti 
in  splenic  diseases*  and  in  hepatic  rirrhosis.     In  gout  there  is  diuiiu-j 
isbed  elimiuation  during  the  chronic  period,  most  marked  just  pre- 
ceding an  attack,  and  an  inci*eased  elimiuation  during  and  followiug' 
the  exacerbations.     In    acute  articular  rheumatism   the  elimination 
increases,    to   return   to   and    fall    below    the    normal    during   con- 
valescence.    In   diabetes  the  amount  of  uric   acid   is   usually  sub* 
normal,  although  it  is  often  increased  to  as  high  as  3   gm.  in  24 
hours,  when  the  sugar  is  diminished  in  quantity.     By  reason  of  its 
very  sparing  solubility,  uric  acid  frequently  forma  sediments  and  cal- 
culi, consisting  either  of  free  uric  aeid  or  of  the  less  soluble  of  the 
urates.     It  must  be  noted  in  this  connection  that  uric  acid  is  muoli 


URINE 


723 


aore  sohible  in  the  presence  of  nrea  than  in  pure  water.  While 
S6,€00  parts  of  water  are  required  to  dissolve  1  part  of  uric  acid,  the 
same  quantity  dissolves  in  1900  parts  of  a  2%  solution  of  urea^  about 

tthe  proportion  eontaiued  in  the  urine. 
The  principal  methods  of  quantitative  determination  of  uric 
acid  are  those  of  Heintz,  of  Hopkins  and  the  Ludwi^r-Salkowski 
method.  The  older  method  of  Heintz^  which  consists  in  precipitation 
of  the  eric  acid  by  strong  acidnlation  with  hydrochloric  acid,  and 
weighing  the  crystals,  is  inaccurate  by  reason  of  incomplete  precipi- 
tation by  this  treatment;  indeed,  samples  are  met  with  from  which 
no  precipitation  whatever  occurs, 
k  Hopkins^  mtiJujd  is  bnt  slightly  more  elaborate  than  Heiutz^s^ 
Pfcut  much  more  reliable:  100 cc.  of  urine  are  saturated  with  powdered 
ammonium  chlorid  (for  which  about  30gra.  are  required),  and  the 
solution  mixed  and  allowed  to  stand  2  to  3  hours  with  occasional 
stirring.  By  this  treatment  the  uric  acid  is  almost  completely  pre- 
cipitated as  acid  aramonium  urate.  The  precipitate  is  collected  on 
a  filter,  washed  with  saturated  NHiCl  solution,  and  dissolved  in  the 
smallest  possible  quantity  of  hot  water.  To  this  solution  5cc.  of 
HCl  (1:3)  are  added,  and  the  mixture  evaporated  on  the  water  bnth 
until  crystals  of  uric  acid  begin  to  form.  These  are  collected  upon 
a  small,  weighed  titer,  washed  successively  with  water,  alcohol  and 
ether,  dried  and  weighed,  A  correction  is  necessary  for  the  slight 
-solubility  of  uric  acid,  which  is  made  by  adding  0.045  mgm.  for  each 
pee.  of  water  used  in  the  final  washing. 

In  a  modification,  the  chief  object  of  which  is  to  remove  other 
J  reducing  substances  precipitated  with  ammonium  urate,  and  thus  per- 
lit  of  titration  with  permanganate,  and  known  as  the  Folhi- Shaffer 
fethi>dt  200  ec.  of  urine  are  measured  into  a  tall  lieakcr  and  50  re, 
a  reagent  made  by  dissolving  500  gnis.  of  ammonium  sulfate,  i> 
18.  of  uranium  acetate,  and  60  cc.  of  10  per  cent  acetic  acid  in  650 
|l«  of  water,  and  making  up  to  one  liter.  The  mixture  of  urine  and 
But  is  allowed  to  stand  without  stirring  for  about  half  an  hour, 
after  which  the  clear  liquid  is  decanted  off,  or  filtered  through  a  double 
folded  filter.  To  125  cc.  of  the  clear  liquid  5  ec.  of  strong  ammonia 
are  added,  and  the  mixture  set  aside  until  next  day.  The  precipitafe 
is  then  collected  upon  a  filter,  and  washed  with  10  percent  ammonium 
sulfate  solution  until  the  filtrate  is  almt>st  or  quite  free  from  chlorids. 
The  precipitate  is  then  rinsed  back  into  the  beaker;  enough  water  is 
added  to  make  100  cc,  the  precipitate  is  dissolved  by  addition  of  15 
jIBC.  of  concentrated  H2SO4,  and  the  sobition  at  once  titrated  with  N/20 
r>tassium  permanganate  solution,  each  cc,  of  %vhich  corresponds  to 
75  mgm.  of  uric  acid.  A  correction  of  3  mgm.,  for  the  solubility  of 
lb'*  nniinoiiium  urate  in  the  volume  of  liquid  used,  is  to  be  added  to 
be  result. 


724 


MANUAL    OF    CHEMISTRY 


The  Ludwig'Salkowshi  Method,  if  properly  conducted,  is  prohablj* 
somewhat  tiiore  accurate,  but  it  is  more  intricate »  and  requires  to  be 
rapidly  completed  to  avoid  error.  It  depends  upon  the  precipitation 
of  the  uric  acid  as  its  silver  salt»  the  decomposition  of  this  by  HCl, 
and  the  collection  and  weighing  of  the  liberated  uric  acid.  The  stndent 
is  referred  to  more  comprehensive  treatises  for  the  details  of  the 
process.  ^ 

Xanthio  Bases  —  (p.  531).  — The  occuri-ence  of  guanin  and  of 
carniu  In  the  urine  has  not  been  demonstrated:  and  of  the  remaining 
xauthiu  bases  which  are  met  with  in  the  urine  the  most  abundant 
are  heteroxanthin,  paraxanthin,  and  1-nionomethyl-xanthin.  They 
are  normally  present  in  small  amount  only^  the  total  elimination 
being  from  15  to  45  mgm.  in  24  hours.  They  undoubtedly  originate 
in  the  metabolism  of  the  nncleoproteids,  and  are  increased  in  amount 
after  administration  of  nucleins,  and  in  conditions  attended  with 
increased  metabolism  of  leucocytes.  They  may  also  originate  from 
the  caffeiu  and  theobromin  contained  in  coffee,  tea  and  cocoa  (p.  533), 
Xauthin  occasionally  forms  vesical  calculi  of  considerable  size.  Their 
quantitative  determination  is  best  effected  by  Salkowski*s  methotl, 
based  upon  precipitation  of  their  silver  compounds. 

Hippuric  Acid  — (p.  479}^ — is  an  aromatic  araido-acid,  benzovl* 
amido  acetic  acid,  which  exists  in  greatest  abundance  in  the  uriue 
of  the  herbivora»  and  only  in  small  amount  in  normal  human  urine, 
although  the  daily  elinnnation  varies  within  quite  wide  limits,  0.29 
to  2.84  gm.»  and  is  still  further  increased  when  benzoic  acid,  ciuna- 
mic  acid  or  substances  containing  those  acids  or  their  compoands 
are  taken. 

Hippuric  acid  may  be  considered  as  formed  by  the  substitution 
of  the  radical,  benzoyl,  of  benzoic  acid  for  a  hydrogen  atom  in  tie 
amido  group  of  amido -acetic  acidr  CeH5.CO.OH+CH2.NH3.CO0H= 
H30+CH2.NH(CflH5.0O).COOH;  its  production  in  the  body,  there- 
fore, in%"oIve8  the  formation  of  glycocoU  and  of  an  aromatic  deriv- 
ative which  may  supply  the  benzoyl  factor.  Both  of  the  constitnents 
of  hippuric  acid  result,  undoubtedly,  from  protein  metabolism.  Gly- 
cocoU is  a  well -recognized  product  of  such  action,  but  the  roetbod 
and  nk'tit  of  production  of  the  benzoyl  radical  are  not  so  clear.  Beu* 
zoyl- propionic  acid,  CH2(C6H.sCO).CH2.COOH,  is  known  to  be  a 
product  of  intestinal  putrefaction;  and  that  this  is  capable  of  yieWin? 
the  benzoyl  radical  is  demonstrated  by  the  fact  that  when  it  '* 
injected  into  the  circulation  it  is  eliminated  as  hippuric  acid.  The 
administration  of  benzoic  acid  is  also  followed  by  a  corresponding 
increase  in  the  elimination  of  hippuric  acid.  That  some  of  the  steps 
in  the  formation  of  hippuric  acid  are  the  result  of  intestinal  patrefa<^" 
tion  is  also  indicated  bv  marked  diminution  in  its  elimination  in  doga 


725' 


I 


vhose  intestines  are  disinfected.  It  is  probable,  also,  that  the  final 
steps  oeciir  in  the  kidney,  as  hippuric  acid  is  formed  when  arterial 
blood  eonttiitiing  glycocoll  and  benzoic  acid  is  passed  through  the 
isolated  kidneys  of  dogs. 

Little  is  known  of  the  variations  in  elimination  of  bippnric  acid  in 
pathological  i*onditions. 

Oxaluric  Acid— (p,  408)  — is  a  monnreid,  (CONsHalCO.COOH, 
which  exists  in  the  nrine  as  its  ammonium  salt  in  very  small  amount. 
It  is  readily  decomposed,  even  by  boiling  its  solution^  into  area  and* 
oxalic  acidj  and  it  is  undoubtedly  concerned  in  the  formation  of  the 
oxalates  of  the  urine. 

Allantoin — (pp,  515,  713)^ — is  a  diureid  which  occurs  in  very 
minute  quantity  in  the  urine  of  adults,  in  somewhat  larger  amount  in 
that  of  pregnant  women,  and  in  that  of  infants  during  the  first  eight 
days  of  life,  when  the  quantity  of  urea  is  very  small.  It  is  increased 
in  the  urine  of  dogs  after  administration  of  nrie  acid,  and  is,  possibly, 
produiied  from  this  in  the  economy. 

Urinary  Pigments  and  Chromogens. — The  yellow  color  of  the 
nrine  is  due  to  the  presence  of  more  than  one  coloring -matter.  The 
most  abundant  of  those  constantly  present  is  urochrom,  which  is 
accompanied  by  small  quantities  of  hfematoporphyrin  (p.  665),  and 
by  a  ehromogen,  urobilinogen,  which,  shortly  after  the  urine  is  voided, 
gives  rise  to  the  coloring* matter,  urobilin.  Besides  these  and  the 
indoxyl-  and  skatoxyl -compounds,  the  urine  frequently  contains  a  red 
coloring-matter,  uroerythrin,  which  is,  however,  not  constantly  present* 
A  number  of  urinary  coloring- matters  have  been  named,  which  are 
probably  among  the  above-mentioned  or  products  of  the  action  of 
acids  or  of  other  reagents  upon  them  or  upon  other  constituents  of 
the  nrine. 

Urochrom  (of  Garrod)-=is  closely  related  to  urobilin,  from  which 
it  differs  in  not  being  precipitated  by  saturation  of  its  solution  with 
ammonium  sulfate,  and  in  not  giving  either  the  spectrum  or  the 
fluorescence  of  urobilin.  The  two  substances  are  i-eadily  converted 
one  into  the  other;  urochrom  into  urobilin  by  the  reducing  action 
of  aldehyde,  and  umbiliu  into  urochrom  by  moderate  oxidation  with 
permanganate.  Urochrom  contains  nitrogen,  but  no  iron;  it  is 
amorphous,  brown,  soluble  in  water  and  in  dilute  alcohol,  sparingly 
soluble  in  strong  alcohol,  amy  lie  alcohol  or  acetic  ether,  insoluble 
in  ether,  chloroform  or  benzene*  It  is  precipitated  by  lead  acetate^ 
silver  nitrate*  or  mercuric  acetate. 

Urobilin  (of  Jaff§)— does  not  exist  in  fresh  nrine,  but  is  formed 
from  urobilinogen,  probably  by  the  action  of  light.  There  are  some 
differences  in  the  properties  of  urobilins,  as  described  by  different 
observers,  and  there  may  be  several  urobilins,  or  urobilinoids,  nor- 


726  MANUAL    OF    CHEMISTRY 

mal,  febrile,  etc.  Urobilin -like  substances  have  also  been  obtained 
from  bilirubin,  from  hasmatin  and  from  hsematoporphyrin,  and,  as 
they  have  been  formed  both  by  reduction  and  by  oxidation,  they 
cannot  be  identical  with  each  other.  Urobilin  is  apparently  identical 
with  the  stercobilin  of  the  faBces,  which  is  formed  in  the  intestine 
from  the  bil^- pigments.  Both  the  urinary  and  the  faecal  pigment  are 
increased  in  amount  with  increased  intestinal  putrefaction. 

Urobilin  is  amorphous,  reddish -brown  to  reddish -yellow,  soluble 
in  alcohol,  amylic  alcohol  and  chloroform,  less  soluble  in  ether, 
sparingly  soluble  in  water,  in  which  its  solubility  is  increased  by 
tho  presence  of  neutral  salts.  It  is  precipitated  completely  from  its 
solutions  by  saturation  with  ammonium  sulfate  after  addition  of 
sulfuric  acid.  It  is  soluble  in  alkalies,  from  which  solutions  it  is 
precipitated  by  acids.  It  is  precipitated  from  neutral  or  faintly 
alkaline  solutions  by  lead  acetate,  and  by  zinc  sulfate,  but  not  by 
mercuric  salts.  It  does  not  give  the  Gmelin  reaction,  but  gives  a 
reaction  similar  to  the  biuret  reaction.  Its  concentrated,  neutral, 
alcoholic  solutions  are  brown  in  color;  the  dilute  solutions  yellow 
or  rose -colored,  and  showing  a  strong  green  fluorescence.  The 
acid  solutions  have  the  same  colors,  are  not  fluorescent,  but  show 
a  faint  absorption  band  between  b  and  F.  If  zinc  chlorid  be  added 
to  the  ammoniacal  solution  it  becomes  red,  and  shows  a  fine  green 
fluorescence.  This  solution  gives  a  broad  absorption  band,  extend- 
ing from  about  midway  between  E  and  b  very  nearly  to  F;  and, 
if  concentrated,  a  second  band  over  E  appears  on  careful  acidulation 
with  sulfuric  acid. 

The  chromogen,  urobilinogen,  is  a  colorless  substance,  which 
may  be  obtained  by  precipitation,  caused  by  saturation  of  the  urine 
with  ammonium  sulfate;  or  may  be  extracted  from  the  urine,  acid- 
ulated with  acetic  acid,  by  agitation  with  acetic  ether.  It  is  soluble 
in  chloroform,  ether  and  amylic  alcohol.  Its  solutions  give  no  spec- 
trum, and,  on  exposure  to  light,  soon  become  colored,  from  conver- 
sion of  the  urobilinogen  into  urobilin. 

The  quantity  of  urobilin  eliminated  in  24  hours  has  been  vari- 
ously estimated  as  from  30  to  140  mgm.  Hoppe-Seyler's  method 
of  determination  consists  in  acidulating  100  cc.  of  urine  with  H2SO4, 
precipitating  by  saturation  with  (NH4)2S04,  collection  of  the  pre- 
cipitate after  24  hours,  washing  with  saturated  (NH4)2S04  solution, 
extraction  of  the  residue  with  a  mixture  of  equal  parts  of  chlorofonn 
and  alcohol,  removal  of  alcohol  by  agitation  of  this,  filtered,  solution 
with  water,  evaporation  of  the  chloroform  solution  in  a  weighed 
beaker,  drying  at  100°,  washing  the  residue  with  ether,  drying,  and 
weighing.  By  this  method  Hoppe-Seyler  found  a  mean  of  123  mgm. 
in   24  hours,  and  extremes  of  80  and   140  mgm.     A  spectrophoto- 


URINE 


727 


metric  method,  based  upon  the  same  principle  as  thojse  for  Itamio- 
^iuinn  and  for  indioao,  also  gives  good  results. 

PathDlogi<*ally  the  elimiimtioti  of  urobilinogen  is  increased  in 
conditions  involving  increased  metamorphosis  of  blood  corpuscles, 
in  fevers,  and  in  ieterus,  in  chronic  lead  poisoning,  and  in  acute 
poisoning  by  antipyrin  and  antifebrin* 

Uroerythrin  exists  in  small  quantity  in  normal  urine,  and  is  the 
substance  which  gives  a  pink  or  red  color  to  'Materitious  deposits." 
It  is  soluble  in  amylic  alcohol,  forming  solutions  which  are  rose- 
colored  if  dilute,  orange  or  fiery -red  if  coneentrated^  which  are  not 
fluorescent,  and  which  give  a  spectrum  of  a  single  band,  broader 
than  that  of  urobilin,  extending  from  midway  between  D  and  E 
nearly  to  F,  with  a  lighter  part  between  E  and  b.  Its  solutions 
are  colored  carmine*  red  by  H2SO4,  and  grass -green  by  alkalies.  A 
rough  method  for  detecting  its  presence  in  excess  consists  of  pre- 
cipitating the  urine  with  lead  acetate,  and  allowing  the  precipitate 
to  settle  for  15  minutes  in  the  dark.  In  presence  of  exress  of  uro- 
erythrin the  precipitate  is  distinctly  pink,  otherwise  it  is  white. 

Uroerythrin  is  increased  in  amount  in  the  urine  after  violent 
exercise,  after  excess  of  food  or  of  alcohol,  in  disturbances  of  diges- 
tion, fevers,  and  derangements  of  the  hepatic  circulation. 

Organic  Compounds  Containing  Sulfur. — We  have  seen  (p*  702) 
that  the  sulfur  elimiuated  in  the  urine  is  contained  in  the  three  forms  of 
mineral  sulfates,  ester  sulfates  and  neutral  sulfur.  So  far  as  is  known, 
all  of  the  sulfur  compounds  from  which  the  neutral  sulfur  is  derived 
also  contain  nitrogen.  As  practically  all  of  the  sulfur  compounds  of 
the  urine  are  derived  from  the  metabolism  of  the  sulfur- containing 
complex  of  the  proteins,  attempts  have  been  made  to  estimate  vari- 
ations in  protein  metabolism  by  determinations  of  total  sulfur  and  of 
its  several  fractions  in  the  urine.  These  have  not  been  as  satisfactory 
in  their  results  as  similar  investigations  based  upon  nitrogen  determi- 
nations, principally  because  of  the  much  smaller  (0.3  to  2.4  per  cent) 
and  more  varying  sulfur  content  of  the  proteins^  and  partly  because 
less  reliance  is  to  be  placed  upon  the  strict  accuracy  of  sn!ftir  de- 
terminations than  upon  those  of  nitrogen  by  existiug  methods. 

Certain  regular  variations  of  total  sulfur  and  of  its  distribution 
have,  however,  been  observed,  dependent  upon  the  protein  content  of 
the  food.  With  diminution  of  protein  metabolism  there  is,  as  would 
be  expected,  a  marked  dimintition  of  the  total  sulfur  elimination. 
Thus  a  healthy  man,  of  70  kilos  weight,  whose  total  urinary  sulfur 
elimination  during  four  days  upon  a  mixed  diet  was  3,32,  3,09,  3.27 
and  3.34  gms.  80:^,  excreted  upon  a  nitrogen- poor  diet  1.45,  1.05, 
0.88,  0,65,  0.88  and  0.77  gms.  This  diminution  in  absolute  amount 
fell  principally  upon  the  mineral  sulfur,  the  ester  sulfur  being  dimiu- 


728' 


MANUAL    OF    CHEMISTRY 


ished  to  a  much  less  degree  and  the  neutral  sulfur  remaining  almost 
constant,   and   consequently  the   percentage  of   mineral  stilfur  waaj 
diminished,  while  those  of  both  ester -sulfur  and  neutral -sulfur  wore 
increased. 

Ester- sulfates.*- The  occurrence  of  these  compounds  has  been 
referred  to  in  connection  with  the  sulfates  (p.  702),  and  thej  am 
considered  here  at  greater  length,  as  the  most  important  among  them 
contain  nitrogen.  Their  constitution  is  similar  to  that  of  the  acid 
esters  (p.  358),  from  which  theydififer  in  containing  phenolic  in  place 
of  alcoholic  radicals.  Their  relations  are  shown  by  the  following 
formulcD; 


CH3 

CH2,0H 


OH 


O.CHs.CHj 

Ethjl'solfiirle  add. 


^OH 


O^  ^O.CHs 


PhtnoL 


Phenyl -9iilfiiriG  ftcUU 


N 

H 
Indoiyl. 


0  OH 

B  NH 

^   \      /      \ 
O  O.C^CH— CjHi 


Isdox^l-Bulfmie  Add. 


P 


The  compounds  of  this  class  which  are  known  to  occur  in  the 
urine  are  the  sodium  and  potassium  salts^  particularly  the  latter,  of 
the  ester -sulfuric  acids  of  phenol  1  para-cresol,  catechol,  quinoU  i^^ 
doxyl,  and  skatoxyl. 

The  phenol  and  para<cresol  compounds  are  usually  determined 
together  by  precipitation  with  bromin  water,  by  a  method  which  is 
not  very  accurate,  and  which  determines  not  only  the  phenols  in  this 
form  of  combination,  but  also  that  existing  in  phenyl -glucuronic 
acid.  By  this  method  the  amount  of  phenol  and  para-cresol  elimi- 
nated has  been  found  to  vary  from  17  to  51  mgm.  in  twenty -four 
hours.  They  have  not  the  poisonous  qualities  of  the  phenols  from 
which  they  are  derived,  and  their  formation  serves  to  protect  the  sys- 
tem not  only  from  the  toxic  effects  of  these  substances,  when  formed 
as  products  of  intestinal  putrefaction,  but  also  from  that  of  carbohc 
acid  to  the  limit  of  the  amount  of  sulfates  available.  In  poisoning  by 
carbolic  acid  the  whole  of  the  sulfuric  acid  of  the  urine  is  in  ethereal 
combination. 


I 

J 


.- \ 


ITHINE 

Of  the  three  diphenols,  catechol  and  qnlnol  have  been  fmind  in 
the  urine  of  the  horse,  and  in  traces  in  hnman  urine.  The  third, 
resorcinol,  has  not  been  met  with  in  this  sitnatimi. 

Indoxyl-sulfates  —  Indican  ^  Uroxanthin  —  ( p.  5 11 )  is  the  prin- 
cipal parent  snbstanee  of  urinary  indifjo,  which  is  also  derived  from 
indoxyl-gincuronie  acid.  The  origin  of  both  is  undoubtedly  in  th© 
indole  produced  in  intestinal  putrefaction.  They  disappear  from  the 
urine  of  dogs  wlM)se  intestines  are  disinfected,  they  are  not  present  in 
the  urine  of  new* born  infants,  and  thej'  were  also  absent  in  a  case  of 
artificial  anus  at  the  lower  part  of  the  ileum.  On  reduction  of  the 
protein  content  of  the  diet  to  the  minimum  they  are  very  much  re- 
duced in  amount,  or  disappear  entirely,  owing  to  lack  of  pabulum  for 
the  saprophytic  bacteria  in  the  intestine. 

The  amount  of  indigo  derivable  from  the  two  compounds  men- 
tionedi  eliminated  in  24  hours,  is  from  5  to  20  mgm.  normally  in 
man.  In  some  of  the  lower  animals  it  is  much  greater,  in  the  horse 
25  times  greater.  It  is  nearer  the  higher  limit  with  animal  food, 
nearer  the  lower  with  a  vegetable  diet.  The  elimination  of  an  excess 
is  designated  as  indicanuria^  and  is  a  measure  of  the  intensity  of 
putrefactive  changes  taking  place  in  the  intestine.  Therefore  it 
occurs  in  hypochlorhydria  (p.  619)  from  any  cause.  But  in  the 
opposite  condition  of  hyperchlorhydria  in  gastric  ul  jer  there  is  also 
indicanuria.  Indieanuria  also  occurs  in  conditions  in  which  there  is 
diminished  perista'^sis  of  the  small  intestine,  as  in  ileus  and  peri- 
tonitis, not  in  simple  constipation;  also  in  conditions  in  which  putre- 
factive changes  occur  in  the  body  elsewhere  than  in  the  intestiuej  as 
in  empyema,  putrid  bronchitis,  gangrene  of  the  lungs,  etc. 

The  tests  used  for  the  detection  and  quantitative  estimation  of 
indoxyl  derivatives  in  the  urine  are  based  upon  their  decomposition 
by  hydrochloric  acid  into  indoxyl  and  sulfates,  and  the  oxidation  of 
the  former  to  indigo  blue. 

Obermayer's  modification  of  the  J(t0  method  is  probably  the 
best:  The  urine  is  mixed  with  1/5  its  volume  of  20%  solution  of  lead 
acetate  and  filtered.  The  filtrate  is  mixed  with  an  equal  volume  of 
fuming  hydrochloric  acid  contnining  ^^:1CM>0  of  ferric  chlorid,  a  few 
drops  of  chloroform  are  added,  and  the  mixture  strongly  shaken  1  to 
2  minutes.  With  normal  urine  the  chloroform  remains  colorless  or 
almost  80;  but  if  an  excess  of  indoxyl  compounds  he  present  the 
chloroform  is  cohired  blue,  and  the  depth  of  the  color  is  a  rough  indi- 
cation of  the  degree  of  the  excess*  An  arbitrary  expression  of  the 
quantity  of  indigo  maybe  made  by  Folin's  method  of  colorimetric  com- 
parison with  FehHng's  solution  r  Exactly  toT  of  the  total  urine  of 
twenty -four  hours  is  taken  for  each  determination.  This  is  treated 
with  Obermeyer's  reagent  and  the  liberated  indigo  is  taken  up  with 


730  MANUAL  OF  CHSJUBTBIT 

5  cc.  of  chloroform.  This  eolation  is  oomfMired  wilih  FehUng's  sola* 
tion  in  a  oolorimeter,  the  copper  solution  being  civen  the  arbitrtiy 
valae  of  100.  Colorimetric  comparisons  of  the  solntions  of  indigo 
obtained  from  the  nrine  with  pore  bine  liquids  are  someiiriiat  inter- 
fered with  by  the  red  color  of  the  skatozyl  derivatiYe  which  aeeom* 
panics  the  former.  The  best  method  <^  more  exact  qnaatitative 
determination  is  Milller's  spectrophotometric  method,  which  is  based 
npon  the  same  principle  as  Vierordt's  method  of  'haemoglobin  de* 
termination  (p.  676),  and  requires  similar  apparatus. 

Skatoiyl-aQliKlies  UfOhsBmatlii  correspond  in  conaltUitton  to 
the  indoxyl-sulfates,  and  have  a  similar  origin.  Like  the  indosTi 
componndist  they  are  chromogens,  and  on  decomposition  tiiegryidd 
red  or  violet  Mdoring-matters,  which  are  referred  to  as  ^indigo  red." 
When  the  Obermayer  test  as  above  described,  but  .befwe  additioii  of 
chloroform,  is  applied  to  urine  containing  excess  of  skaftox^  com* 
tKMinds,  it  becomes  red  or  violet  in  color,  and  chloroform  when 
added  and  shaken  with  tl^  liquid  is  colored  red  or  viiritet.  The 
^reaction  of  Boeenbach  ^  is  due  to  uroheematin.  It  conaistB  of  the 
addition  of  concentrated  nitric  acid  drop  by  drop  to  the  boiling  urine, 
which,  in  presence  of  excess  of  the  chromogen  uroheematin,  assmneB 
a  deep  wine-red  color,  which  is  usually  tinged  blue  firom  the  presenee 
of  indigo  blue.  Such  urines  also  turn  darker,  reddish,  violet,  or  emt 
black,  from  the  surCsoe  downwards,  on  mere  exposure  to  air. 

Neutral  Sulfur  Componnda. — The.  absolute  amount  of  neutisl 
sulfur  eliminated  is  not  affected  by  the  protein -content  of  the  diet, 
varying  from  0.10  to  0.35  gm.  in  twenty-four  hours.  Its  proportion 
to  total  sulfur  varies  from  3.4  to  10.0  per  cent  with  a  mixed  diet,  and 
from  11.0  to  36.0  per  cent  with  a  nitrogen-poor  diet. 

But  little  is  known  definitely  of  the  nature  of  the  compounds  from 
which  this  neutral  sulfur  is  derived.  A  considerable  proportion  is 
contained  in  substances  derived  from  the  sulfur  compounds  of  the 
bile,  which  in  turn  originate  from  the  cystin  complex  of  the  proteins. 
Taurocarbamic  acid,  really  a  substituted  urea:  H2N.CO.NH.CHr 
CH2.SO3H,  and  taurin,  its  acid  component:  H2N.CH2.CH2.SO3H, 
both  exist  in  normal  urine,  but  whether  constantly  or  not  is  not  de- 
termined. When  taurin  is  administered  to  men  or  dogs  it  is  elim- 
inated partly  in  its  own  form  and  partly  as  ammonium  taurocarbamate, 
the  synthesis  of  the  taurocarbamate  from  urea  and  taurin  probably 
occurring  in  the  kidneys. 

Oxyproteic  acid,  alloxyproteic  acid,  and  antoxyproteic  acid  are 
amorphous,  solid  substances,  containing  sulfur  and  nitix>gen,  which 
appear  to  be  definite  compounds,  and  which  it  is  said  are  eliminated 
in  quite  notable  quantity:  3  to  4  gms.  daily.  If  the  observations 
which  have  been  published  concerning  them  be  verified,  they  may 


UEINE 


731 


aceonnt  for  a  considerable  proportion  not  only  of  the  neutral  sulfur, 
but  also  of  the  uiidetermined  nitrogeti.  They  are  not  proteins,  as  they 
do  not  give  the  xanthoproteic  or  biuret  reactions,  although  oxyproteic 
acid  gives  a  faint  Millon  reaction.  They  are  extremely  soluble  and  are 
separated  from  the  urine  only  with  considerable  diffieuky.  Two  other 
nitrogen -sulfur  acids  have  been  described  as  oecurring  in  normal 
urine:  uroprotelc  acid  and  urofcrric  acid,  the  former  of  which  is 
probably  identical  with  alloxyproteic  acid,  and  the  latter  is  a  snlfo- 
conjngate  aeid. 

A  thiocyanate  is  constantly  present  in  the  urine  of  man  and  of 
many  animals;  in  man  to  a  daily  elimination  of  0,2  to  0.8  gm.  It  is 
prohalily  the  thiocyanate  of  the  saliva  and  gastric  juice.  The  so- 
ealled  mucin  wliich  constitutes  the  organic  portion  of  the  ■^uubecnla'* 
which  separates  from  the  urine  on  standing  is  probably  a  nucleo- 
proteid  (see  Cystiu,  etc,,  p,  757). 

Organic  Compounds  Containing  neither  Nitrogen  nor  Sulfur,— 
These  are  few  in  number  and  are  present  only  in  small  amount.  The 
best  known  are  oxalic  acid  and  the  conjugate  glucnronates. 

Oxalic  Acid  —  is  a  normal  constituent  of  the  urine  in  small 
araonut,  not  exceeding  0.02  gm,  in  24  hours,  and  is  present  as 
calcium  oxalate,  held  in  solution  by  the  acid  reaction  of  the  mono- 
sodie  phosphate.  It  is  partly  taken  in  with  the  food,  as  it  exists 
in  many  fruits  and  vegetables,  apples,  spinach,  sorrel,  asparagus, 
rhubarb,  etc.  But  it  is  also  produced  in  the  system  from  proteins 
and  fats,  as  it  does  not  disappear  from  the  urine  when  the  diet  is 
limited  to  these,  or  with  deprivation  of  food.  Calcium  oxalate  is 
frequently  deposited  from  subacid  urines  either  in  octahedral  crys- 
tals or  in  dumb-bells,  and  sometimes  forms  calculi,  mulberry  calculi, 
which  are  white,  hard  and  nodulated.  The  elimination  of  oxalie 
acid  is  increused  in  intestinal  disturbances,  sometimes  with  transient 
alburamnriu,  and  sometimes  in  diabetes.  Idiopathic  oxalnria,  or  the 
oxalic  acid  diatljesis,  is  a  condition  in  which  the  elimination  of 
oxalates  is  notably  increased,  the  canse  of  which  is  unknown.  In 
oxalic  acid  poistuiing  the  elimination  of  the  poison  takes  place 
through  the  kidut^ys,  and  the  tubules  become  plugged  with  crystals 
of  calcium  oxalate. 

For  the  quantitative  determination  of  oxalic  acid  500  cc.  of 
nrine  are  treated  with  CaCl2,  rendered  alkaline  with  ammonium  hy- 
droxid,  and  then  acid  with  acetic  acid.  In  24  honrs  the  precipitate 
is  collected  upon  a  small  filter,  washed  with  water,  and  extracted 
with  dilute  hydrochloric  acid  (which  leaves  the  nric  acid  upon  the 
filter).  The  acid  solution  is  again  alkalized  with  ammonium  hy- 
droxid  and  the  precipitate  collected  npon  a  small  filter,  washed, 
drirl,   burnt,  stronglv  ignited  and  weighed  as  calcium  o^  "^'e 


732 


MANCAL    OF    CHEMISTRY 


weight  of  CaO  fouod,  multiplied  by  2.2857,  grives  the  amount  of 
calcium  oxalate;  or,  multiplied  by  1.6071,  the  amouDt  of  oxalic  acid 
in  500  cc.  urine. 

Conjugate  Glucuronates. — Not  all  of  the  phenolic  compounds, 
skatoxyl,  indoxyl,  phenol,  etc.,  produced  by  intestinal  putrefaction 
goes  to  form  ester  sulfates;  a  portioa  of  each  of  these  substances  is 
constantly  eliminated  in  the  urine  as  compounds  of  glucuronic  acid: 
CH0.(CH0H)4-C00H.  This  acid  does  not  occur  in  its  own  form,  or 
in  those  of  its  simple  salts  or  esters,  in  the  urine  or  elsewhere  in  the 
system,  but  only  in  the  ahape  of  salts  of  conjugate  acids  which  it  forms 
with  phenols  and  with  a  great  variety  of  other  compounds,  both 
aliphatic  and  cyclic.  These  conjugate  compounds  appear  to  be  glucosid- 
like  substances  (p,  465)  in  which  the  glucuronic  acid  residue  is  not 
contained  in  its  own  form,  but  from  which  it  may  be  split  by  a  simple 
decomposition  attended  by  atomic  rearrangement:  CflHrwO.(CnOH)5.- 
COOH  =  C6H5,OH+CHO.(CHOH);.COOH.  Indeed,  a  glucosid  is 
known,  called  euxaothic  acid,  which  yields  glucuronic  acid  by  sneh 
decomposition.  That  glucuronic  acid  does  not  exist  in  the  system 
except  in  conjugate  combination  is  probably  not  due  solely  to  the  fact 
that,  because  of  its  great  proneuess  to  oxidation,  it  can  only  exist 
there  when  so  protected,  but  probably  also  to  the  method  of  its  forma- 
tion. The  most  natural  origin  of  glucuronic  acid  would  at  first  sight 
appear  to  be  by  oxidation  of  glucose:  CH0.(CH0H)i.CH20H,  but  it 
is  not  conceivable  that  the  primary  alcoholic  group  could  be  converted 
into  a  carboxyl,  leaving  the  niuc^i  more  readily  oxidizable  aldehyde 
group  intact;  and  no  such  formation  has  been  realized  in  vitro.  It  is 
much  more  probable  that  glucuronic  acid  is  not  formed  at  all  in  the 
system,  but  that  the  glucosid* like  substances  above  referred  to  are 
produced  by  actions  between  some  carbohydrate  and  the  phenolic  or 
other  compounds,  and  that  glneuronic  acid,  or  the  simple  glucuronates, 
are  only  produced  in  the  decomposition.  The  normally  formed  con- 
jugate glucuronates  are  present  in  the  urine  only  in  small  amount,  but 
after  administration  of  certain  medicinal  substances  these  are  elimi- 
nated in  the  form  of  their  glucuronic  derivatives,  sueh  as  campho-glu- 
curooic  acid  with  camphor,  and  urochloralic  acid  with  chloral.  The 
conjugate  glucuronic  acids  are  Ifpvagyrous,  while  the  acid  itself  is 
dextrogyrous.  They  are  readily  hydrolysed  by  dilute  acids,  with  liber- 
ation of  glucuronic  acid.  Thus  urochloralic  acid  is  decomposed  into 
glucuronic  acid  and  trichlor-alcohoh  CCl:t.CO.CH2,(CHOH)4.COOH 
-|-H20=GH0.  (CHOH)4,COOH+CCb.CH20H.  Glueuronic  acid  is  a 
syrup »  but  forms  crystalline  salts;  it  is  very  soluble  in  water  and  in 
alcohol;  it  reduces  the  salts  of  copper,  silver  and  bismuth;  is  not  fer- 
mentable, gives  the  furfurol  reaction,  also  the  plilorogluein  reaction  of 
the  pentoses,  and  forms  a  crystalline  compound  with  phenylhydrazin. 


* 


URINE 


733 


Toxicity  of  Urine. — Human  uriue,  wheu  injected  into  the  eircula- 
tiou  wf  uuitntilh,  is  quite  poisonous,  Tlins,  rabbits  are  killed  by  an 
average  tunoiiut  uf  45  ec.  of  uornjal  human  nrine  per  kilo  of  weight  of 
the  auiuml^  injeL'ted  at  one  hnie.  The  urine  of  persons  sufifering 
from  febrile  diseases  is  more  aetively  poisonous  than  that  of  healthy 
individuals.  The  urine  exereted  iu  the  early  morniug  hours  is  more 
af*tive  than  that  formed  durinjj  the  day  and  early  night,  and  tlie  night 
nrine  produees  convulsions,  while  the  day  urine  behaves  as  a  oareolic 
poison.  The  urine  of  some  of  the  lower  animals,  notably  that  of  the 
cat,  iis!  still  more  poisonous  to  rabbits  than  human  uriue.  The  toxieity 
of  the  nrine  is  referable  in  part  to  the  action  of  the  potassium  salts 
(p.  229),  but  it  is  not  proportionate  to  their  quantity.  It  is  estimated 
that  about  45  per  cent  of  the  poisonous  action  is  due  to  potassium 
eompoiuids;  the  remainder  l»eing  due  in  part  to  the  urinary  euloriug- 
mattet^s,  in  part  to  the  moderately  toxi<*  quality  of  nrea»  uric  acid,  etc., 
and  in  part  to  the  presence  of  urinary  leueomains,  so-called  ptomains, 
Several  observers  have  obtained  minute  quantities  of  basic,  actively 
poisonous  substances  from  mniual  urine,  and  in  larger  amount  fiom 
febrile  urine.  The  exact  chemical  nature  of  these  bodies  is  not  deter- 
mined, although  one  of  thera»  Pouchet's  base,  has  been  obtained  in 
the  erystalline  form,  and  was  found  to  have  the  composition  CtHuNiOs, 
or  C7H12N.1O2.  True  ptomains,  such  as  cadaverin,  putresein,  and 
other  diamins  have  also  been  found  in  pathological  urines »  notably  in 
cystinuria* 

ABNORMAL    CONSTITUKNTS, 


Of  the  following  substances  some,  such  as  albumin,  hj]emogIobin, 
etc.,  are  literally  abnormal  to  the  urine,  that  is  their  presence  in  any 
amount  is  the  result  of  a  pathological  condition;  others,  such  as 
glucose,  cystiu,  etc.,  are  considered  abnormal  for  reasons  of  con- 
venience; they  are  normally  pi'esent,  but  only  iu  very  nunute  quan- 
tities, insufficient  to  be  revealed  by  the  tests  customarily  used, 
but  ai^e  much  increased  in  amount  in  certaiu  pathological  conditions. 

Proteins. — The  proteins  which  may  occur  in  the  nrine  are  serum 
albumin,  serum  globulin,  alburaoses,  including  Briicke's  peptone,  and 
histon,  a  nncleoalbumen,  flbrin,  and  hiemoglobin. 

Serum  Albumin  and  Scrum  Globulin  —  are  usually  included  in 
the  term  '* albumin,"  as  clinically  applied  to  the  urine,  as  both  re- 
spond to  the  tests  generally  used.  The  question  whether  albumin  is 
or  is  not  a  strictly  normal  constituent  of  the  urine,  in  the  sense  above 
indicated,  has  been  much  discussed.  The  weight  of  evidence  is, 
however,  in  favor  of  the  view  that  the  presence  of  albumin  is  always 
an  abnormal  condition.  That  it  may  be  present,  however^  in  quan- 
tities as  large  as  25  to  75  mgm.  to  the  litre,  in  the  urine  of  ^ 


tU 


MANUAL    OP    CHEMISTRY 


under  conditions  which  are  iiut  absoliitt^ly  pathological,  although  de» 
parting  lixmi  those  whiuh  are  usual »  cauuot  be  denied. 

Serum  albumin  and  sernm  ijrloliuliii  appear  in  the  urine  in  a  great 
variety  of  abnormal  conditions,  nsiially  in  qnantity  not  exceeding  5 
p/m.  rarely  reaeldng  10  p/m,  and  very  exceptionally  50  p/ni.  (1) 
Funrtional  lilbHrninnrias  inelnde  those  conditions  which  are  sometimes 
coni^idered  as  so-called  '^physiologic/*  or  normal  albuminurias,  in 
which  the  presence  of  albumin  is  transitory  and  due  to  an  exaggera- 
tion or  deficiency  of  some  normal  condition;  after  severe  muscular 
exertion,  under  great  mental  strain  or  enjotion,  in  anaemic  children 
and  youths,  accompanying  exr^essivc  elimination  of  uric  or  oxalic 
acid,  alimentary  albuminuria  due  to  excess  of  protein  diet,  particu* 
larly  if  raw.  (2)  Febrile,  in  most  acute  febrile  diseases,  particularly 
during  convalescence.  In  typhoid  it  is  always  present,  and  disap- 
pears on  the  fifth  to  the  eighth  day  in  light  cases,  on  the  tenth  day  or 
later  in  severe  cases.  In  pneumonia  albumin  is  always  present, 
sometimes  abondanily.  In  any  acute  febrile  disease  albumin  may  be 
present,  without  the  existence  of  any  structural  change  in  the  kidney, 
(3)  Circuintorif ,  due  to  disLurbances  of  the  blood -pressure,  in  wliich 
the  quantity  of  albumiu  is  usually  small,  as  in  valvular  heart- lesions, 
degeneration  of  the  heart  muscle,  diseases  of  the  coronary  arteries, 
impeded  pulmonary  circuiation,  in  pregnancy  by  pi*essure  upon  the 
renal  veins,  after  cold  baths,  in  intestinal  catarrh  and  in  Asiatic 
eholera.  (4)  Htfmir,  dne  to  pathologic  mudtfication  of  the  blood 
proteius,  in  purpura,  scurvy,  leukaemia,  pernicious  anaemia,  jaundice, 
diabetes,  and  syphilis.  (5)  Toxic,  by  the  action  of  ha?matic  poisons 
such  as  lead,  mercury,  chloroform,  or  by  irritating  action  upon  the 
glandular  epithelium  of  the  kidmn%  such  as  is  caused  by  mercury, 
eantharides,  oxalic  acid,  mineral  acids,  iodin,  phosphorus,  arsenic, 
antimony,  carbolic  acid,  salicylic  acid,  turpentine,  and  nitrates.  (G) 
Accidenhd,  by  the  presence  in  the  urine  of  blood,  pus,  or  semen.  So 
far  as  the  two  former  are  concei-ned,  they  may  be  either  renal,  or 
post -renal  in  origin.  (7)  Nephritic,  in  acute  nephritis  albumin  is 
present  in  large  amount,  as  much  as  5  to  20  gm.  in  24  houi*s,  and  the 
sediment  contains  casts.  In  chronic  parenchymatous  nephritis  albu- 
min is  also  constantly  present,  and  in  still  larger  quantity,  as  high  as 
15  to  'jOgm.  in  24  hours.  In  chronic  interstitial  nephritis  the  amount 
is  small,  rarely  exceeding  2  to  5gm.  in  24  hours,  and  variable,  while 
casts  may  be  absent.  In  amyloid  degeneration  the  amount  is  usually 
small,  although  it  may  reach  10  gm.  in  24  hours.  In  this  condition 
the  proportion  of  serum  globulin  to  serum  albumin  is  greater  than  in 
other  kidney  lesions,  it  is  usually  from  1:0.8  to  1:1.4.  Pure  gU^^b- 
inuria,  that  is  the  presence  in  the  urine  of  serum  globulin,  unaccom- 
panied by  serum  albumin »  has  not  beeu  observed. 


UKINE 


735 


I 


For  tlie  detection  of  serum  albumin  and  serum  globulin  in  the 

nrine  it  must  be  perfectly  clear.  If  not  80  it  is  to  ha  filteretl,  and 
if  this  does  not  render  it  franspan^nt,  it  is  to  be  treated  with  a  few 
drops  of  inagnesiii  inixtnre  (p.  168  note),  and  agrain  filtered,  Ur  the 
nrine  is  sluiken  with  kieselguhr  {diatomaeeous  earth)  and  liltereiL 

(1)  Hfat  and  nitric  acid  test, —The  clear  urine,  if  alkaline^  is 
rendered  just  acid  by  addition,  guttatim,  of  dilute  acetic  acid  (nitric 
acid  should  not  be  used,  and  the  auidulation  is  iniperative)*  The 
nrine  is  now  heated  to  near  boiliu}'',  and  if  a  cloudiness  or  coaijulum 
be  farmed,  nitric  acid  is  added  slowly  to  the  extent  of  about  ten 
drops.  If  heat  produces  a  cloudiness  which  clears  up  completely  on 
addition  of  nitric  aeid,  it  is  due  to  excess  of  earthy  phosphates.  If 
a  'cloudiness  caused  by  heat  do  not  clear  up  (it  may  increase)  on 
addition  of  nitric  acid,  it  is  due  to  serum  albumin  or  serum  globulin. 
Sometimes  the  urine  after  heating  and  addition  of  nitric  acid 
deposits  a  granular  sediment  on  cooling;  this  is  due  to  the  separa- 
tion of  urates. 

(2)  HfUer's  test  —  is  more  delicate  than  the  above,  and  reacts 
with  urine  containing  0.002  per  cent,  of  albumin.  About  1  cm.  of 
nitric  acid  is  phiced  in  a  test-tube,  which  is  then  held  at  an  angle 
and  the  urine  is  allowed  to  flow  slowly  from  a  pipette  upou  the  sur- 
face of  the  acid  (Fig.  45)  so  as  to  form  a  distinct  layer  with  the 
minimum  of  mixing  of  the  two  liquids.  Tlie  procedure  frtM^ueotly 
directed,  of  ^^uuden-unniug  *^  the  acid  from  a  pipette  uuder  the  nriue, 
placed  in  a  test-tube,  does  not  give  as  good  results.  After  with- 
drawing the  pipette,  the  test-tube  is  returned  to  the  vertical  slowly, 
and  the  line  of  junction  of  the  two  lirjiiids  examined  against  a  dark 
background.     If  the   nrine  contain  albumin  a  white,  opaque  band, 

■  whose  upper  and  lower  borders  are  aharpltf  defined,  will  be  seen  at 
the  line  of  jnuction  of  the  two  liquids.     .4  colored  band  is  geaendly 
observed  in  applying  this  test,  which  has  no  relation  to  the  pi^esence 
_^  of    albumin,    it    may    be    of 

^M  ^^^A   ^^"*^  shade  of  red  from  the 

^^^^^K  ^^^^^^"       presence  of  excess  of  normal 

^^^^^F  ^^jh^^^  |-r  coloring  matter,  or,  of  nro* 

^^H        ^^^^.^--^i^^^gpl  erythriu,    blue,    or  almost 

^.^^^'^'^^^^^^^^  black,  from   the  preseu<'e  of 

■■j^^^*^^  indican  in  excess,  or  giving 

the  colors  of  the  Gmelin  reac- 
tion (p.  637)  in  the  presence 
of  bile.  When  urates  are  present  in  excess  a  white  zone  is  also  formed 
which,  however t  differs  from  that  caused  by  coagulation  of  albumin  in 
the  following  particular-s:  it  is  not  at,  but  slightly  above,  the  line  of 
contact  of  the  two  li<|nids;    while  its  lower  border  may  be  sharply 


Fio.  45. 


736 


JAL    OF    CHEMISTRY 


defined »  it  has  no   upper   border,  but   shades   off  gradually  i 
upper  layer;   and  it  is  not  produced  with  the  urine  diluted  wi 
or  two  volumes  of  water.    When  urea  is  present  in  excess,  crystals 
of  urea   nitrate    separate,    but    these    differ   widely    in    appearance 
from  the  amorphous   coagulum  of  albumin;    are   formed    through- 
out the  liquid  after  a  short  time;    and  are  not  produced  with   the 
diluted  urine.     Occasionally  the  urine  contains  resinous  substanees«i 
usually  administered  as  medicines,  which  with  Heller's  test  give 
zone    resembling    that    produced    by  albumin.      This    may   be  dis- 
tinguished by  removing  the  portion  of  the  liquid  containing  the  riug 
by  means  of  a  pipette   and  shaking  it  in  another  test-tube  with  a 
little  ether,  when  it  will  clear  if  it   be  resinous,   but  will  remain 
cloudy   if   albuminous.      Sometimes   uudihited   urines   give   no   im- 
mediate reaction,  and  only  a  faint,  ill -defined  ring  after  standing,^! 
but  the  diluted  urine  gives  an  immediate  and  well-defined  reaction a^B 
this  is  caused  by  the  so-called  nueleoalburain  {p.  740).     True  muein^" 
may  also  produce  a  faint  opalescence,  but  no  well-defined  ring,  and 
the   opalescence   disappears   on    slight   rotation   of   the   tube.     The 
primary  albumoses  respond  to  the  Heller  test,  but  they  redissolve  oq^_ 
heating  the  test-tube,  and  they  are  not  coagulated   by  heat,  heDC8^| 
the  heat  test  should  always  be  used  as  well  as  the  Heller. 

(3)  Prfcipitadon   by  Nfittnd   SaJfs, — ^  Several    tests    are    in    use,. 
based   upon    the    precipitation   of   albumin   from    acid    solutions  b|j 
saturated  solutions  of  neutral  salts,  sneh  as  ammonium  sulfate,  sodlnii 
sulfate,  magnesium  sulfate  or  sodium  chlorid.     Roberta'  r^a^^w^  coii^ 
sists  of  a  saturated  solution  of  sodium  chlorid  containing  5  per  ceu^ 
of  strong  hydrochloric  acid^  and  filtered  if  necessary.     The  urine  ii* 
floatj-'d  upon  the  wanned  rw^^ent  in  tbc  same  manner  as  in  the  appli 
cation  of  Heller's  method;   atrd  a  milky  zone  indicates  the  presence  of 
aJbumin.     Albumoses  are  also  precipitated,  but  not  urates;   nor  does 
the  colored  zoue  appear. 

If  acetic  acid  be  added  to  albuminous  urine  to  strongly  acid  reae*j 
tion,  and  then  an  equal  volume  of  saturated  sodium  sulfate  solution, 
aud  the  mixture  boiled,  the  albumin  is  completely  precipitated,  while 
the  albumoses  remain  in  solution  in  the  hot  liquid.  This  reaction, 
designated  as  Panuni^s  method,  is  utilized  to  free  the  urine  frorn^ 
albumin  in  testing  for  albumoses  (p.  739). 

Of  her  Preripitniion  T*^.vt^. —Several  of  the  precipitation  reactions 
of  the  albumins  have  been  utilized  for  the  detection  of  albumin  in  the 
urine.     Pnmiinent  among  these  are  the  following: 

(4)  Fermvyanid  Reartkm, — Acetic  acid  is  added  to  the  urine  in 
such  amount  as  to  he  present  in  the  proportion  of  2%,  and  then  a 
1:20  solution  of  potassium  ferrocyanid  drop  by  drop.  A  clondiaes 
or  fiaky  precipitate  is  produced  by  serum  albumin,  serum  globulinj 


III 

1 

le 

n, 

n^^ 


I 


I 


I 


I 


UBINE  ,  737 

or  primary  albomoses,  but  the  last  named  are  redissolved  by  addi- 
tion of  niueh  acetic  acid  and  warming.  The  test  is  quite  as  delicatf^ 
as  the  Heller.  If  the  addition  of  acetic  acid  alone  produce  a  eloud- 
iness,  it  is  dae  to  the  presence  of  mucin  or  of  mucin -like  siibstaiiees, 
and  the  urine  is  to  be  filtered  before  addition  of  the  ferrocyanid. 

In  the  fol [owing  tests  the  urine  is  to  be  floated  upon  the  surface 
of  th*.*  reag'cnt  in  the  same  nuniucr  as  in  the  application  of  tin* 
Heller  tei*t.  and  the  t-haracteristic  appearance  is  also  the  forinatinn 
of  a  milky  zone, 

{5)  TrirJihrarrtic  Arid  Remiion. — This  reaction  is  still  more 
delicate  than  the  HL4lHr.  A  strong  solution  of  the  acid  (sp.  gr.^= 
1.14)  is  used,  or  a  crystal  of  the  acid  is  dropped  into  the  urine, 
and,  dissolving,  it  forms  a  layer  at  the  bottom.  Serum  albumin, 
serum  globulin  and  primary  albiimoses  respond  to  the  test,  but  the 
last-named  redissolve  on  heating,  while  the  others  remain.  Excess 
of  urates  also  gives  rise  to  the  same  appearance  as  with  the  Heller 
reaction,  and,  similarly,  its  formation  is  prevented  by  previous  dilu* 
tion  of  tljc  urine.  The  colored  ztme  produced  by  urinary  pigments  in 
the  Heller  test  is  not  formed  with  this  or  with  the  following  reagents. 

(6)  Spiegler's  Rtagent  —  consists  of  8  gms.  of  mercuric  chlorid, 
4gms.  of  tartaric  acid  and  20  cc.  of  glycerol,  dissoh^ed  in  200  cc.  of 
water.  A  few  drops  of  aeetic  acid  arc  U*  be  added  to  the  urine  for 
this  test,  which  is  said  to  be  the  most  delicate  of  those  for  albumin. 
Its  limit  is  placed  at  1:2;jO.*XHJ,  and  it  is  fret|ucntly  observed  with 
normal  urine.  The  sp,  gr,  of  urines  below  1.005  is  to  be  raised 
by  addition  of  salt  solution  before  application  of  the  test.  Primary 
albumoses  give  the  I'cactiou,  but  secondary  albumoses  (urinary  pep- 
tone) do  not, 

(7)  Tfinref\s  Eeagfinf^^ is  made  by  dissolving  1.35 gm.  of  mer- 
curic chlorid  and  3.32  gms,  of  potassium  iodid  in  separate  por- 
tions of  water,  mixing  the  solutions,  making  the  bulk  up  to  GOcc, 
and  adding  20  cc.  of  glacial  acetic  acid.  Secondary  allmmoses  are 
also  precipitated,  but  redissolve  on  heatirjg.  Certain  alkaloids  are 
also  precipitated,  but  they  are  dissolved  by  ether  shaken  with  the 
aqueous  liquid,  which  tben  becomes  clear.  Several  other  reagents, 
containing  mei'curic  salts  (Bonchardat^s,  Jolle's,  Zouchlos',  Fiir- 
gringer's)  are  in  use. 

(8)  Oiii'f'r\s  Reagent  is  one  of  several  (Sonnenschein's,  Maschke's, 
Jaowrowski's)  containing  tnngstates  or  molybdates.  It  is  a  mixture 
of  equal  parts  of  a  20%  solation  of  sodium  tungstate,  and  G0% 
solution  of  citric  acid.  It  precipitates  secondai'y  albumoses,  which, 
however,  dissolve  on  heating,  and  also  alkrdoids. 

(9)  Rorh\s  Rf agent,  Salicylsulfonic  acid,  and  (10)  Rleglfrs  Rf- 
agent,  /3-naphthol-o-sulfouic  acid  tasaprol),  and  orthophenohsnlfonic 


738  MjVNUAL    OP    CHEMISTRY 

nr'id  (aseptol),  are  used  iu  the  same  manner  as  trichloracetic  acid. 
They  precipitate  albnraoses,  which  redissolve  on  heating. 

(11)  EsbacJi^s  Eeagent  —  is  one  of  several  containing  picric  acid. 
It  contains  lOgms.  of  picric  acid  and  20gms.  of  citric  acid  in  the 
liter.  It  is  mixed  with  or  floated  upon  the  urine.  It  precipitates 
all  proteins,  also  uric  acid,  creatinin  and  certain  alkaloids. 

(12)  Metaphosphoric  Acid  —  is  best  used  in  the  form  of  Blum's 
reagent,  which  consists  of  a  10%  solution  of  the  acid,  to  which  have 
been  added  0.05  gm.  of  manganous  chlorid,  dissolved  in  a  little 
dihite  hydrochloric  acid,  and  a  little  lead  peroxid,  and  the  solution 
filtered.  The  reagent  should  not  be  used  if  it  have  lost  its  pink 
color.     It  precipitates  albumoses  and  uric  acid. 

The  color  reactions  of  the  albumins  (p.  577)  cannot  be  conveniently 
used  in  testing  for  albumin  in  urine. 

Test  for  Globulin. —  Neutralize  the  urine  exactly  with  ammonia, 
filter,  and  add  an  equal  volume  of  neutral,  saturated  solution  of 
ammonium  sulfate:  globulin  separates  as  a  white,  fiocculent  precipi- 
tate. Albumin  may  be  tested  for  in  the  filtrate  from  this  precipitate 
by  acidulation  with  acetic  acid  and  heating.  Excess  of  urates  may 
give  rise  to  a  precipitate  in  using  this  test,  but  it  is  only  formed 
after  a  time,  is  not  fiocculent,  but  granular,  and  is  not  white,  but 
colored. 

Quantitative   Determination   of  Albumin   and   Globulin. —  The 
only  method  of  determining   the  quantity  of  "albumin"   with  any 
degree  of  accuracy  is  gravimetric.    From  20  to  100  cc.  of  the  clear 
urine  (according  as  the  qualitative  testing  has  indicated  a  large  or 
a  small  quantity  of  albumin)   are  made  up  to  100 cc.  of   liquid  by 
addition  of  water,  if  necessary,  and  slowly  heated.      As  the  boiling 
temperature  is  approached,  2-4  drops  of  dilute  acetic  acid  are  added, 
iiud  the  mixture  boiled  for  a  few  minutes,  until  the  coagulated  al- 
bumin has  become  fiocculent,  when  it  is  collected  upon  a  weighed 
filter,  washed,  first  with  water  contain iug  a  little  nitric  acid,  then 
with  boiling  water,  then  with  alcohol,  and  finally  once  or  twice  with 
ether,  dried  at   110°,  and  weighed.       For  accurate  detenu inatious, 
the  filter  and  coagulum  are  burnt  and   moderately  ignited,   the  ash 
weighed,  and  its  weight  subtracted  from  that  of  the  albumin  found. 

Quantitative  Determination  of  Globulin. — One  hundred  cc.  of  the 
clear  urine  are  accurately  neutralized  with  ammonia,  an  equal  volume 
of  a  neutral,  saturated  solution  of  ammonium  sulfate  is  added  and 
the  mixture  allowed  to  stand  for  an  hour,  after  which  the  precip- 
itated globulin  is  collected  upon  a  weighed  filter,  washed  with  one- 
half  saturated  ammonium  sulfate  solution,  dried  at  110°,  extracted 
with  boiling  water,  then  with  alcohol,  and  then  with  ether,  dried 
again  at  110°,  and  weighed.     The  filter  and  contents  are  then  burnt, 


739 


ignited,  cooled  and  weighed,  and  tlit*  weight  o(  the  ash  subtracted 
froirj  the  weis:ht  of  globiilio,  phis  iish,  previously  obtained.  To  de- 
termiue  the  relation  between  albomin  aiul  globulin  a  determination  of 
albumin  and  globulin,  and  another  of  gh>bulin  alone  are  made,  as 
above  directed:    the  differenee  is  the  amount  of  albumin. 

Albumoses  (Peptones). — Hubstanees  similar  to  the  ijroducts  of 
the  action  of  digestive  enzymei*  iipnn  proteins  occur  in  the  urine  patho- 
h)gically.  Peptones  in  the  modern  sense,  i.  e.»  not  precipitabJe  by 
saturation  with  ammonium  sulfate,  do  not  appear  m  the  urine  nor' 
uially  or  pathologically.  In  the  condition  des^ignated  as  "peptonuria/' 
the  so  called  ''urinary  peptone'*  consists  prineipally  of  substances 
closely  resembling,  if  not  identical  with»  the  secondary  albumoses, 
(deutero-albumost's,  p.  615).  Peptonuria  in  this  sense  occurs  in  dis- 
eases attended  with  tlie  formation  of  large  deposits  of  pus,  in  yellow 
atrophy  and  in  abscess  of  the  liver,  in  certain  intestinal  diseases^ 
including  typhoid,  in  tubercular  ulceration,  in  scurvy,  pyaemia, 
septicaemia,  leuktpmia,  in  diseases  of  pregnancy,  in  endocarditis,  in 
pneumonia,  in  pleurisy,  in  dipbtiieria,  in  suppurative  meningitis^ 
and    in    certain    forms    of    poisoning. 

Primary  albumoses,  hetero -albumoses,  have  been  met  with  in 
the  urine  (albumosuria)  ex<'(^ptionally  iti  cases  of  osteomalaehia. 

The  presence  of  albumoses  is  best  detected  by  Panamas  method 
(p.  736) :  acetic  acid  is  added  to  strongly  acid  reaction  and  then  au 
erjtinl  volume  of  saturated  sodtuna  sulfate  solution,  and  the  liquid  is 
heated  to  boiling  and  ialtered  hot;  albumoses  are  precipitated  before 
the  boiling,  are  redissolved  on  boiling,  and  are  again  pt^cipitated 
from  the   filtrate  on  cooling. 

If  nitrnc  acid  be  added  to  the  hot  filtrate  from  the  coagulated 
albumin,  produrcd  by  boiling  a  urine  containing  albumin  and  albu- 
moses, no  immediate  precipitation  occurs,  luit  on  cooling  a  white  or 
yellow  precipitate  of  albumose  .separates,  which  redissolves  on  heat- 
ing, and  rc«ip|)cars  «in  cooling. 

Heteroallmmoiie  (primary  albumose)  gives  the  abo%^e  reactions, 
and  is  further  cliaraeterized  by  its  action  with  the  heat  test:  at  a 
tcmperatm-e  uf  abmit  (>0°  the  urine  becomes  milky  and  di^pnsifs  an 
imperfectly  tlo(*<'Tih'nt,  gummy  nnderial,  whifh  adheres  to  the  \\n\li> 
of  the  beaker,  and  which,  in  an  acid  liiinitl,  dissolves  on  boiling,  to 
r«*!»ppear  on  co<ding  again. 

For  thv  dctcf'tion  of  snndl  qnautities  of  secondary  albumoses 
(urinary  peptutu*)  the  niethcKl  of  Ilofmeister,  ahhough  intrieate,  it^ 
tlif^  mcFst  rpiiablc.  It  cousists  in  the  complete  removal  of  albumin 
by  precipitation  with  ferric  chlorid,  the  precipitation  of  the  albumose 
with  phosphotungBtic  acid,  the  decomposition  of  the  precipitate,  and 
the  application  of  the  biuret  reaction  to  the  solution  of  alVuimose. 


740 


MANUAL    or    CHEMISTRr 


The   student  is   referred   to   more   coraprehensive   treatises  for  the 
details  of  the  process. 

Mucin-like    Substances.  —  The   urine   sometimes   contains   true , 
raacius   and   mTcleoproteids,   produced   in    the   urinary   tract   belowi| 
the  kidneys.      The  '* nubecula"  {p.  694)  whirrh  separates  as  a  deli- 
cate cloud  from  normal  urine  on  standing,  has  for  its  chief  protein 
constituent  a  substance  resembling  ovomucoid  (p*  r>84),  and  desig- 
nated as  urinary  mucoid.      It  is  a   glycoproteid,  which  on  heating  ^ 
witli  dilute  acids,  yields  a  reducing  substance,  but  no  sulfuric  acid 
(see    below).    It  is  soluble  in  dilute  alkaline  solutions,  from  which  it 
is  precipitated  by  acetic  acid,  but  soluble  in  an  excess  of  the  acid.     It 
is  similarly  precipitated  by,  and  soluble  in  excess  of  mineral  acids. 
It  is  not  coagulated  by  heat,  even  in  presence  of  sodium  eblorid  to 
saturation;  but  it  is  precipitated  in  the  cold  by  saturation  with  mag- 
nesium or  ammonium  sulfate. 

The  substance  usually  referred  to  as  nucleoalbumeu,  or  as  mucus,. 
in  the  urine  consists  of  different  protein -coagulating  substances,  J 
among  which  are  nucleic  acids,  taurocholic  acid,  especially  iai 
icterus,  and  particularly 

Chondroitin-sulfuric  acid   {p.  594),   which  is  present    in    small] 
amount  in  normal  urine,  and  is  increased  in  diseases  involving  the 
renal  and  vesical  epithelium,  as  in  acute  and  chronic  nephritis  and  iuj 
cystitis,   also  in  '* functional''  albuminuria,  in  icterus,   and  from  the^ 
action   of   many  poisons,   notably   of   corrosive   sublimate,  arsenic, 
pyrogallie  acid,  naphtbol  and  anilin.     This  substance  exists  in  the 
urine,  as  well  as  in  cartilage,  in  combination  with  albumins  in  the 
form  of  chondroproteids,  or  choudroalbumins. 

The  chondroproteids  react  with  the  Heller  test,  and  their  presence 
in  excess  is  to  be  suspected  when  the  urine  becomes  cloudy  on  addi- 
tion of  acetic  acid  in  the  cold,  and  gives  a  more  distinct  Heller 
reaction  after  dilution  than  when  undiluted.  To  separate  and 
identify  chondroproteids  a  large  volume  of  urine  is  treated  with 
chloroform  to  prevent  decomposition,  and  submitted  to  dialysis  to 
remove  salts;  acetic  acid  is  then  added  in  the  proportion  of  2  p/m, 
and  the  mixture  allowed  to  stand  until  the  precipitate  settles.  This 
is  then  dissolved  in  the  smallest  quantity  of  dilute  alkali  and  again 
precipitated  with  acetic  acid.  The  precipitate  is  then  heated  on  tlu» 
water* bath  with  5  per  cent,  hydrochloric  acid  and  the  solutions 
divided  into  two  parts,  one  of  which  is  tested  for  its  reducing  action  by 
Fehliug^s  solution,  and  the  other  for  sulfuric  acid  by  barium  chlorid. 

A  histon,  a  phosphorized  protein,  apparently  identical  with 
nncleo-histon,  has  been  met  with  in  the  urine  in  a  case  of  leukemia, 
and  also  in  cases  of  peritonitis  following  appendicitis^  pneumoQi&» 
erysipelas  and  scarlatina. 


URINE 


741 


Haemoglobin. — The  blood  eoloringf- matter  may  exist  in  the  aritie 
in  the  two  conditions  of  ha?inaturia  and  of  hemoglobinuria.  The 
former  is  the  eousequenee  of  a  haijraorrhage  somewhere  in  the 
urinary  tract,  the  latter  of  profound  alteration  in  the  blood,  and 
elimination  of  the  liberated  hemoglobin.  In  the  former  condition 
the  sediment  contains  blood -corpuscles,  and  sometimes  blood -casts 
or  small  clots,  and  albumin  is  present  in  the  urine,  whose  color  is 
bright- red,  reddish -brown,  or  dark -brown.  The  location  of  the 
haemorrhage  cannot  be  determined  by  examination  of  the  urine, 
although  it  may  be  noticed  that,  if  it  is  urethral,  the  last  portions 
of  the  urine  passed  are  free  from  blood;  if  it  is  renal,  blood -casts 
are  usually  found  in  the  sediment,  and,  if  it  is  vesical,  blood -clots 
of  considerable  size  may  be  present. 

Hamioglobinuria,  in  which  the  urine  contains  oxyh«emoglobin  or 
methi^uioglobin  in  solution,  with  no  blood -corpuscles,  or  very  few, 
in  the  sediment,  is  most  frequently  the  result  of  poisonings  as  by 
hydrogen  arsenid,  potassium  chlorate,  pyrogallol  and  naphthol,  but 
it  also  occurs  in  malarial  fevers  in  the  tropics,  and  after  severe 
burns  or  after  transfusion  of  blood.  The  urine  varies  in  color  frotn 
bright -red  to  dark -brown. 

Tests  for  Blood -pigment, — ^(l)The  urine,  suitably  diluted  if  neces- 
sary, gives  the  spectrum  of  oxyhemoglobin,  or  that  of  methemo- 
globin  (p.  661)*  {2)  Heller- g  lest:  the  faintly  apid  urine  is  boiled, 
w^hen  a  dirty  brow^nish  eoagulum  of  albumin,  containing  the  blood- 
pigment,  is  formed.  Sodium  hydroxid  is  added  to  the  hot  liquid^ 
w^hich  then  clears,  becomes  greenish  in  thin  layers,  and  on  standiug 
deposits  a  red  material  having  greenish  reflections,  which  consists 
of  phosphates  and  ha^matin.  This  preeipitate  may  be  collected  and 
used  for  (3)  Tekhtnann's  test  (p,  664),  (4)  The  gumac  reaction: 
the  urine  is  rendered  faintly  acid  if  not  already  so,  and  upon  its 
surface  is  floated  a  mixture  of  equal  parts  of  tincture  of  guaiac 
and  old  oil  of  turpentine.  In  the  presence  of  blood  coloring -matter 
a  white  zone  is  produced,  which  soon  turns  bluish,  greenish,  and 
finally  a  brilliant  blue,  and  on  gently  shaking  the  tube  the  wiiole 
liquid  is  colored  blue  if  the  quantity  of  pigment  is  sufficient.  In 
the  reagent  ozonic  ether  (ether  containing  hydrogen  peroxid)  may 
be  used  in  place  of  oil  of  turpentine*  Pas  gives  a  similar  color 
with  tincture  of  guaiac  alone. 

Hsematoporphyrin,  related  to  urobilin  and  isomeric  with  biliru- 
bin, is  a  normal  constituent  of  the  urine  in  small  amount,  but  is 
notably  increased  in  amount  in  poisoning  by  sulfonal,  trional  and 
tetronal,  or  even  after  long -continued  medicinal  administration  of 
these  remedies;  also,  in  hepatic  cirrhosis  and  in  croupous  pneumonia. 
Usually  it  colors  the  urine  red,  sometimes  of  a  dark  port* wine  color, 


742  BiANUAL    OP    CHEMISTRY 

bat  it  may  be  present  in  considerable  amount  in  arines  which  it 
colors  only  slightly.     It  is  not  accompanied  by  albumin. 

To  test  the  urine  for  hsematoporphyrin  100  to  200  cc.  are  precip- 
itated with  10%  sodium  hydroxid  solution;  the  precipitate,  of  phos- 
phates and  coloring- matter,  is  dissolved  in  about  10  cc.  of  alcohol 
acidulated  with  hydrochloric  acid,  and  the  solution  is  examined  with 
the  spectroscope  (p.  665).  If  the  result  be  negative  the  alcoholic 
solution  is  rendered  alkaline  with  ammonium  hydroxid,  the  precip- 
itate dissolved  in  a  little  dilute  acetic  acid,  agitated  with  chloroform, 
and  the  chloroform  solution  again  examined  spectroscopically. 

Biliary  Constituents. —  The  urine  may  contain  the  biliary  salts 
and  pigments  as  a  consequence  of  reabsorption  of  bile,  caused  by 
obstruction  of  the  biliary  ducts,  or  when  the  blood -pressure  in  the 
liver  is  lowered  (hepatogenic  icterus) ;  or  the  biliary  pigments  may 
appear  in  the  urine  in  consequence  of  their  formation  in  the  system 
elsewhere  than  in  the  liver,  as  hsematoidin  is  produced  from  the 
blood  coloring -matter  (p.  640),  as  in  pernicious  anaemia,  malaria, 
typhoid,  and  in  poisoning  by  hydrogen  arsenid  (hsematogenic  icterus) . 
Urine  containing  bile  is  golden-yellow  or  greenish -brown  in  color, 
and  the  epithelium  which  it  contains  is  also  dyed  yellow.  It  is 
usually  cloudy,  contains  albumin,  and,  when  shaken,  forms  a  yellow, 
persistent  froth  upon  its  surface. 

The  biliary  salts  are  rarely  tested  for,  because  the  examination  for 
the  equally  characteristic  coloring -matters  is  much  more  easily  con- 
ducted. They  may,  however,  be  detected  by  the  Pettenkofer  reaction, 
if  care  be  had  to  avoid  possible  sources  of  error  from  other  substances 
which  also  respond  to  the  test.  To  this  end  the  urine  is  coueen- 
trated,  extracted  with  alcohol,  and  the  alcoholic  extract  filtered  and 
freed  from  alcohol  by  evaporation.  The  residue  is  dissolved  in  a 
little  water  and  precipitated  with  lead  acetate  and  ammonia.  The 
lead  precipitate  is  collected,  washed,  extracted  with  boiling  alcohol, 
which  is  filtered  off  hot,  treated  with  a  little  sodium  hydroxid  solution 
and  evaporated  to  dryness.  The  residue  is  extracted  with  a  little 
absolute  alcohol,  the  solution  mixed  with  about  ten  volumes  of  per- 
fectly anhydrous  ether,  the  precipitate  collected  on  a  small  filter, 
washed  with  a  little  ether,  dissolved  in  a  small  quantity  of  water  and 
tested  by  the  Pettenkofer  method  as  directed  on  p   636. 

For  the  detection  of  the  biliary  colorinfj- matters  the  reactions 
described  on  p.  637  are  used.  The  Gmelin  reaction 'may  be  modified 
to  Roisenbach^s  method,  which  consists  in  filtering  the  urine  through 
a  small  filter,  and  tou<'hing  the  dried  filter  with  a  drop  of  nitroso- 
nitric  acid,  when  the  colors  are  produced  in  rings  about  the  drop. 
This  reaction  is  not  satisfactory  in  dark  urines  containing  excess  of 
indican.      In  using  Hammarsten^s  reaction  with  urines  containing 


URINE 


743 


blood  coloring- matter,  or  very  small  quantities  of  bile  piginents»  a 
preparatory  treatment  is  required,  which  consists  in  addiiit,^  barium 
chlorid  to  the  urine,  centrifugating,  pouring  off  the  supeniataiit 
liquid,  sinking  the  sedimeut  with  2  ee.  of  the  reagent^  and  ceutri- 
fugating  again,  when  a  bluish -green  solution  is  obtained.  Smith's 
reatjtiou  may  also  be  used:  float  dilute  tijicture  of  iudin  (1:10)  on 
the  urine,  wheu  the  biliary  pigments  form  a  greeu  ring  at  the  union 
of  the  two  hirers. 

Other  Abnormal  Pigments  —  rrorosfin  is  a  coloring-matter,  not 
present  in  nf>rmnl  urine,  init  apjiearing  in  a  variety  of  abnormal  con- 
ditions, as  in  diabetes  meilitirs,  ehhirusis,  osteomalachia,  nephritis, 
typhoid  fever,  phthisis,  pernicious  aniemia,  etc.  It  exists  in  the  urine 
as  a  chrornogen,  frum  which  it  is  formed  by  the  action  of  acids,  and, 
when  so  liberated,  courmuuieates  a  rose-color  to  the  urine.  It  pro* 
duces  the  rose -colored  ring  so  frequently  observed  in  applying  the 
Heller  test  to  the  pathological  urines.  To  demonstrate  its  presence 
10  cc.  of  1:4  i^ulfurie  acid  are  added  to  50  ec»  of  urine,  which  are 
then  shaken  with  a  few  cc.  of  amylic  alcohol,  and  the  amylic  alcohol 
examined  speetroscopically.  Urorosein  gives  a  spectrum  of  one  band 
between  D  and  E,  and  iu  concentrated  solution,  allows  only  the  red 
and  orange  rays  to  pass.  The  color  is  discharged  by  alkalies,  and 
returns  on  addition  of  acids,  it  is  also  discharged  by  agitation  of 
its  acid  solution  with  powdered  zinc,  and  reappears  soon  by  exposure 
to  air. 

Mflanin  is  formed  from  melanogen  on  exposure  to  air  of  the  urine 
of  patients  with  melanotic  tumors.  Such  urines  are  normal  in  color 
when  first  voided,  but  become  dark  or  even  black  on  standing.  They 
may  be  distinguished  from  urines  belmviug  sinjilarly  from  the  pres- 
ence of  derivatives  of  carbolic  acid,  salol,  etc.,  by  tbe  facts  that  tht\v 
give  witli-  bromin-wnter  in-ccipitates  which,  although  at  fli-st  yellow, 
gradually  change  to  blaek,  and  tluit  with  ferrie  chhrrid  they  give  pre- 
cipitates wjiifli  are  at  first  gray»  changing  to  black. 

Alkaptonitrki  is  another  rare  condition  in  which  the  urine, 
normally  colored  at  firsts  turns  dark  on  standing,  and  which  occurs 
in  individuals  suffering  from  tuberculosis  or  from  cerebral  tumors. 
It  is  due  to  tlie  pn^scuce  of  aromatic  oxyaeids,  notably  of  glycosuric 
acid  (pp.  460,  461)  which  on  decompositiou  yield  colored  phenolic 
derivatives,  probably  similar  to  those  which  color  the  urine  in 
poisoning  by  phenols  and  diphenols,  fTlyeosuric  acid  is  also  i»f 
interest  in  connection  with  the  testing  of  urine  for  sugar  in  dark- 
colored  urines,  because  it  reduces  the  eupric  salts  (Fehling's  test, 
et(\),  although  it  does  not  reduce  those  of  bismuth  (Boettger's  test)t 
and  it  doe-*  not   fHrrnent. 

Ehrlich's  Diazo- reaction, — The  uriue  in  typhoid  fever  contains  a 


744 


"iWAh    OF    CHEMISTRT 


substance  Ti^hich  gives  a  more  or  less  intense  red  color  with  diazo* 
benzene- snlfonie  aeid  and  ammonia.  The  reaction,  which  can  be 
obtained  with  typhoid  nrine  usually  on  the  fifth  or  sixth  day,  but 
not  later  than  the  twenty -second,  was  at  first  said  to  be  patho- 
gnomonic of  that  disease,  but  it  is  also  obtained  with  the  urine  of 
acute  pulmonary  phthisis,  in  which,  however,  it  does  not  appear 
before  the  third  week  and  continues  to  the  end,  and  also  in  scarla- 
tina, measles,  smallpox  and  other  acute  febrile  diseases.  The  reagent 
used  is  most  conveniently  kept  in  two  solutions:  (1)  a  saturated 
solution  of  sulfanilic  acid  in  a  mixture  of  50  cc.  of  hydrochloric  acid 
and  950  cc.  of  water;  and  (2)  a  0.5  per  cent,  solution  of  sodium 
nitrite.  When  used  1  cc.  of  (2)  is  added  to  40  cc.  of  (1)  and  the 
mixture  shaken.  Equal  volumes  of  the  urine  and  the  reagrent 
are  shaken  together  hi  a  test- tube  and  1-2  cc.  of  ammonia  are 
floated  upon  the  surface  of  the  mixture,  when,  in  an  affirmative 
result,  a  red  baud  is  formed  at  the  junction  of  the  liquids.  Or  a 
better  method  of  applying  the  test  consists  of  adding  50  cc.  of 
absolute  alcohol  to  10  cc.  of  urine,  filtering,  adding  20  cc.  of  the 
reagent  gradually  from  a  bui-ette  to  30 cc,  of  the  filtrate  in  an  Erlen- 
meyer  flask,  with  agitation  after  each  addition,  and  then  slowly 
adding  ammonia,  when  a  red  color  is  produced,  which  remains  per- 
manent wheu  the  ammonia  has  been  added  in  excess.  Urines  con- 
taining biliary  pigments  become  very  dark  and  cloudy. 

To  what  substance  in  the  urine  this  reaction  is  due  is  still 
unknown.  The  reaction  is,  however,  given  intensely  by  histidin  and 
by  tyrosiu,  and  by  sturin,  edestin  and  other  proteins  from  which 
histidiu  or  tyrosin  is  obtainable,  but  not  by  other  protein  split 
products. 

Glucose* — Affirmative  results,  not  only  with  the  copper  reduction 
tests,  which  might  be  due  to  nric  acid,  creatinin,  or  glnctironates,  but 
also  with  the  phenyl h^'drazin  and  benzoyl  chlorid  reactions,  which 
are  not  open  to  this  objection,  have  demonstrated  that  perfectly  nor- 
mal urine  contains  glucose.  But  the  sugar  is  normally  present  in 
such  small  amount  that  it  does  not  respond  to  the  sugar  tests  as 
usually  applied.  When  it  does  respond  to  these  it  is  present  in 
abnormal  amount,  and  the  symptom  known  as  glycosuria  exists. 
This  may  or  may  not  be  due  to  a  pathological  condition. 

Normally  the  glucose  content  of  the  blood  varies  within  narrow 
limits^  0,5  to  1  p/ni,  and  in  this  quantity  the  kidneys  present  a  bar- 
rier to  its  passag^e  into  the  nriue,  except  in  the  minute  amounts  above 
refrrred  to.  In  the  condition  known  as  phloridzin  diabetes,  in  which 
glycosuria  follows  upon  the  Administration  of  phloridzin,  it  is  believed 
that  the  phloretin  componont  of  the  ghicosid  exerts  a  toxic  action  upon 
the  kidney  cells   by  which  their  retaining  power  is  diminished  or 


TTBINE 


745 


abolisliecL  All  other  non-toxie  glycoeixrias  are  the  coosequence  of 
hyperglykeemia,  i.  e,,  an  excess  of  glucose  in  the  blood.  This  may  be 
due  either  to  over-prodnction  of  glucose^  or  to  impediment  to  its 
oxidation  to  CO2  and  H2O,  which  is  its  uonnal  final  destiny.  Clearly, 
therefore,  the  consideration  of  glycosuria  in  some  of  its  aspects  is 
inseparable  from  that  of  the  glycogenic  function  of  the  liver,  and 
what  we  are  about  to  say  must  be  considered  as  being  in  amplification 
of  what  has  already  been  said  concerning  the  action  of  the  liver  upon 
carbohydrates  (pp.  681,  G83),  apology  beiug  offered  for  some  un- 
avoidable repetition. 

One  of  the  earliest  observations  with  regard  to  glycosuria  was  the 
classic  one  of  CL  Bernard »  that  a  lesion  of  a  certain  area  in  the  floor 
of  the  fonrth  ventricle  in  the  mednlla  is  followed  in  one  to  two  hours 
by  glycosuria,  which  persists  for  five  to  six  hours  in  rabbits,  and  as 
long  as  seven  days  in  dogs.  It  has  since  been  shown  that  this  glyco- 
suria is  due  to  byperglykiPmia,  consequent  upon  excessive  conversion 
of  glycogen  into  glucose  in  the  liver,  resultiug  from  a  disturbance  of 
the  tier%^e  supply  of  that  organ  in  a  manner  witli  which  we  are  not 
concerned  here,  beyond  the  fact  that  the  normal  governing  influence 
ol  the  "center  of  sugar  regulation"^'  in  the  medulla  is  transmitted 
through  the  pnenmogastric  and  the  splanchnic  nerves.  First  it  was 
found  that  the  operation  was  successful  with  well -nourished  animals, 
i.  e.,  those  which  had  a  glycogen  reserve;  but  failed  entirely  with 
starved,  glycogen -poor  animals;  and  also  that  in  animals  killed  some 
little  time  after  the  puncture  the  liver  was  found  to  be  glycogen -free. 
That  these  phenomena  are  due  to  loss  of  power  of  the  liver  to  store 
glycogen  is  shown  by  the  fact  that  if,  in  an  animal  made  as  glj^cogen* 
free  as  possible  by  starvation,  a  solution  of  glucose  be  injected  into 
the  mesenteric  vein^  only  a  little  sugar  appears  in  thenrine;  but  if  the 
same  experiment  be  made  with  an  animal  upon  which  the  puncture  has 
been  made,  a  copious  glycosuria  soon  follows.  That  the  liver  is  the 
only  organ  affected  by  the  puncture  is  sho^vn  by  the  fact  that  glyco- 
suria does  not  follow  after  ligation  of  the  hepatic  vessels.  There  has 
been  ranch  speculation  with  regard  to  the  mechanism  of  pnncture- 
gl5*c osti  ri a ,  1> u  t  n o t h  i  n  g  de fi  n  i  te  h as  b ee n  es t  ab  1  i s h  e d .  T h e  s u  pp os  i  t  i o n 
is,  however,  plausible  that  under  normal  conditions  glycogen  is  con- 
tained in  the  liver  cells,  not  merely  deposited  in  its  own  form,  but  in 
a  condition  of  more  or  less  loose  combination*  in  which  it  is  protected 
from  the  action  of  the  hepatic  diastase,  and  that  the  result  of  the  dis- 
turbance of  regulation  is  to  suddenly  liberate  the  glycogen  from  this 
comjxiund,  and  expose  it  to  the  action  of  the  enzyme.  Glycosuria  is 
also  produced  b}"  a  method  involving  no  mechanical  injury  to  the 
center  in  the  medulla,  but  exerting  npon  it  a  toxic  action.  This  is  also, 
by  the  way,  in  support  of  the  view  now  entertained  that  the  calcium 


746  MANUAL    OF    CHSMISTEY 

salts  are  more  **  normal "  to  the  system  than  are  those  of  sodinm.  The 
intravenous  injeetion  of  a  1  per  eent  sodinm  chloricl  solation  is  fol- 
lowed by  glycosuria,  and  the  same  effect  is  produced  by  solutions  of 
other  sodium  salts,  Nal,  NaBr  and  NaNOi.  This  i^yoosuria  is  not 
produced  if  the  splanchnic  nerves  have  been  previoudy  divided,  and 
it  is  arrested  by  intravenous  injection  of  calcium  chlorid  solution,  but 
may  be  again  provoked  by  further  injection  of  sodium  salt*  and  in  a 
degree  proportionate  to  the  concentration  of  the  solution.  That  the 
action  of  the  sodium  salt  is  upon  the  center  in  the  medulla  is  rendered 
highly  probable  by  the  fact  that,  if  the  axillary  artery  be  ligated, 
injection  of  the  salt  solution  into  the  artery  on  the  central  side  of  the 
ligature  is  followed  by  much  more  prompt  and  intense  glycosuria 
than  is  injection  into  the  vessel  on  the  peripheral  side  of  the  ligature. 
The  oondition  known  as  pancreatic  diabetes  is  an  instance  of  a 
glycosuria  dependent  upon  deficient  consumption  of  sugar,  which  may 
or  may  not  be  associated  with  normal  production,  as  in  any  event,  k 
the  balance  be  disturbed  in  that  direction,  there  will  be  accunralaU«m 
and  hyperglykasmia,  and,  in  fact,  in  the  operative  pancreatic  glycosuria, 
referred  to  below,  the  sugar  content  of  tiie  blood  is  above  the  n<»rmal. 
If  the  pancreas  be  totally  extirpated  in  dogs,  an  intense  glycosuria 
results.  The  extirpation  of  the  gland  must  be  complete  to  insure  the 
occurrence  of  glycosuria,  as  frequently  it  does  not  result  if  a  minute 
fraction  be  allowed  to  remain,  whether  in  communication  with  the 
duct  or  not,  or  even  if  a  small  fragment  be  transplanted  under  the 
skin,  and  the  remainder  of  the  gland  completely  removed.  But  re- 
moval of  this  remaining  fraction  is  followed  by  glycosuria.  With 
partial  extirpation  of  the  gland,  however,  g:lycosurin  sometimes  fol- 
lows and  sometimes  does  not,  from  which  it  may  be  inferred  that  all 
parts  of  the  gland  are  not  equivalent  :'n  their  action  in  this  regard. 
That  the  glycosuria  does  not  depend  upon  interference  with  digestion 
of  the  carbohydrates  by  the  pancreatic  secretion  is  shown  by  the  facts 
that  it  does  not  follow  after  ligation  of  the  duct,  or  even  after  removal 
of  that  portion  of  the  pancreas  which  is  in  more  direct  communication 
with  the  duct,  so  long  as  a  small  fraction  of  the  gland  tissue  is 
allowed  to  remain.  It  might  be  supposed  that  the  pancreas  may  act, 
something  after  the  manner  of  the  liver,  by  holding  back  substances 
whose  presence  in  the  blood  would  prevent  the  normal  carbohydrate 
metabolism.  Were  this  the  case,  transfusion  of  blood  from  a  depan- 
creatized  animal  to  a  normal  one  would  cause  glycosuria  in  the  latter. 
But  that  this  does  not  occur  has  been  demonstrated.  The  pancreas 
therefore  exerts  its  governing  action  in  carbohydrate  metabolism  upon 
some  other  glucose -producing  or  glucose -consuming  organ.  That  the 
glycosuria  does  not  depend  upon  the  suppression  of  an  influence  of 
the  pancreas  which  favors  the  glycogen -forming  power  of  the  liver. 


URINE  747 

and  the  consequent  flooding  of  the  system  with  glucose  from  the 
intestine,  is  sliown  by  the  facts  that  after  the  death 'of  depancreatized 
animals,  the  liver  is  found  not  to  have  suffered  the  loss  of  weight 
which  all  other  organs  have  sustained,  and  to  be  rich  in  glycogen. 
The  chief  seat  of  glucose  consu!npti<m  in  the  system  is  in  the  muscles. 
That  pancreas  glyirosuria  depends  upon  an  interference  with  this 
destruction  is  shown  directly  by  the  fact  that  a  fluid  obtained  by  great 
pressure  from  muscular  tissue  does  not  decompose  glucose,  nor  does 
a  liquid  similarly  obtained  from  the  piiucreas,  but  a  mixture  of  the 
two  liquids  destroys  sugar  energetically.  It  may  be  inferred  that  the 
pancreas  produces  an  internal  secretion  which  activates  the  sugar- 
destroying  function  of  the  muscle,  as  the  formation  and  activity  of 
trypsin  depend  upon  secretin  and  enterokinase.  Whether  this  secre- 
tion is  or  is  not  the  product  of  the  cells  of  the  Langerhans  islands  of 
the  pancreas  is  not  determined,  although  it  would  seem  that  it  might 
be,  as  these  cells  have  been  found  to  exert  a  decomposing  action  upon 
glucose. 

Normally,  glucose  is  oxidized  in  the  system  to  carbon  dioxid  and 
water.  But  there  must  be  a  limit  to  the  amount  of  carbohydrate  food 
which  can  be  utilized  by  the  economy  in  a  given  time.  This  limit 
«eems  to  vary  in  different  individuals,  but  may  be  placed  at  an 
amount  of  total  carbohydrate  equivalent  to  100  to  200  gms.  of  glucose 
in  twenty-four  hours,  and  probably  when  glycosuria  exists  with  a 
daily  ingestion  of  100  gms.,  or  less,  of  glucose  equivalent  it  is  due  to 
a  pathological  condition.  It  is  not  immaterial  in  what  form  the  carbo- 
hydrate is  taken.  If  taken  principally  as  glucose,  which  under  ordi- 
nary conditions  of  life  is  most  unusual,  absorption  will  be  rapid  and 
the  blood  will  shortly  become  surcharged  with  glucose,  and  a  tempo- 
rary glycosuria  will  result  with  relatively  small  quantities. 

Non-pathologic((l  ghjcosurla  may  be  observed:  (1)  with  a  diet 
containing. more  than  200  gms.  of  glucose -equivalent  in  twenty-four 
hours.  A  patliological  alimentary  glycosuria  occurs  with  less  than 
100  gms.  glucose -equivalent,  in  hepatic  and  pancreatic  disease  and  in 
certain  cerebral  di.seases;  (2)  in  pregnancy  and  during  lactation  there 
is  apparently  a  diminution  in  the  power  to  utilize  carbohydrate 
material,  and  glycosuria  frequently  exists  with  a  diet  containing  less 
than  100  gms.  of  glucose-equivalent  in  24  hours,  the  daily  elimina- 
tion sometimes  rising  as  high  as  30  gms.,  but  being  more  usually 
less  than  3  gms.  It  appears  towards  the  end  of  gestation,  and  does 
not  disappear  entirely  until  the  suppression  of  the  lacteal  secretion; 

(3)  in  nursing  children   from  about  the  eighth  day  to  ten  weeks; 

(4)  in  old  persons  (70  to  80  years);  (5)  in  extremely  stout  persons, 
particularly  in  females  at  the  menopause,  the  elimination  sometimes 
reaching  8  to  12  gms.  in  24  hours. 


748 


MANUAL    OF    CRKMISTRY 


Fathologiral   glycosurias   nia.v    he   divided    into   "transitory,"  i 
wliieh  the  quantity  of  sugar  is  not  large,  and  its  presence  not  eon 
.staut;   and  '*perniauent/*  in  whit*h  sugar  is  constantly  present  an 
fre(piently  in  very  large  amount.       TntfK^ifort/  glijrosnria   ocenrs   in 
eertain    hepatic    derangements,    congestion,    cirrhosis    and    amyloid 
degeneration;   in  many  diseases  of  the  central  nervous  system,  with 
tumors  or  hremorrhages  at   the  base  of   the  brain,   in   meningitis, 
eonenssion,    fracture    of    cervical    vertebra,    railway    injuries,    i 
epileptic   and   apoplectic   seizures,   and   also   in   certain    diseases  o! 
the  peripheral  nervous  system,  as  iu  sciatica  and  in  tetanus;   in  aeut 
febrile   diseases,    pneumonia,    typhoid,   acute    articular  rheumatism, 
scarlatina,  etc.,  particularly  during  convalescence,  when  the  eiimina- 
tion  may  reach  5  to  50  gras.  in  24  hours;    under  the  influence  of 
many  poisons,  such  as  curare,   chloral,   carbon   mouoxid,  morphin, 
arsenic,  and  the  anaesthetics. 

Persistent  pathohgiral  glyeonHrm  is  observed  principall}'  in  two 
conditions:  (1)  In  lesions  of  the  brain  involving  the  floor  of  the 
fourth  ventricle;  (2)  in  diabetes  mellitus.  In  this  latter  condition 
tlie  sugar  may  temporarily  disappear  from  the  urine,  particularly  in 
the  earlier  stages  of  the  disease,  in  the  early  morning  urine,  and 
upon  regulation  of  the  diet  by  exclusion  of  carbohydrates.  There  is 
a  diurnal  variation  in  the  elimination  of  sugar,  the  amount  passed 
being  less  during  the  night  than  during  the  day,  the  maximum  being 
reached  about  four  hours  after  the  principal  raeaJ,  and  the  minimum 
six  or  seven  hours  thereafter.  There  is  great  polyuria,  the  quantity 
of  urine  in  24  hours  reaching  as  high  as  50  liters.  The  quantity  of 
sugar  varies  greatly;  an  elimination  of  20()  gras.  in  24  hours  is  by 
no  means  uncommon,  but,  even  with  this  large  amount,  the  elimi- 
nation may  cease  entirely,  particularly  in  the  morning  urine,  by 
exrhision  f»f  carbohydnites  from  the  diet,  under  the  influence 
intercurrent  diseases,  or  in  the  later  stages,  upon  the  appearance 
diabetic  coma.  Instances  have  oeeasionally  been  reported  in  whiej 
the  eliniinatinn  has  reached  400  to  600  gnis.  in  24  hours,  and  on 
instance  in  wliich  1376  gms.  were  discharged  in  one  day.  in  othei 
severe  eases,  terminating  fatally,  the  quantity  of  sugar  eliminat 
has  not  been  large  at  any  time,  not  exceeding  10  gms.  in  24  hoars 
The  non  -  disappearance  of  the  sugar  from  the  urine  on  exclusion  of 
carbohydrates  from  the  diet  is  usually  considered  as  indicating  a 
more  serious  condition,  even  if  the  quantity  be  small,  than  the 
elimination  of  a  large  amount  which  ceases  under  those  circum- 
stances. The  speeitic  gravity-  of  diabetic  urine  is  usually  high,  1030 
to  1060,  but  it  may  be  as  low  as  1012.  In  true  diabetes  there  is  nol 
only  glycosuria,  but  also  azoturia^  and  the  increase  in  the  eliminatioi 
of  nitrogen  appears  to  offer  a  better  measure  of  the  intensity  of  the 


LKINE 


I 


I 
I 


disturbaoce  than  variatioiis  in  the  amount  of  isugar.  In  the  later 
stages  acetoue,  fatty  acids  and  fats  also  appear  in  the  urine  (see 
below). 

As  has  been  already  indicated  (p.  745),  glycosurias  other  than 
those  due  to  nervous  lesions  may  have  their  origin  in  au  inability  of 
the  liver  to  transform  the  carbohydrates  into  glycogen,  or  to  inability 
of  the  muscles  to  utilize  the  carbohydrate  material,  or  to  diseases  of 
the  pancreas. 

Examination  of  Urine  for  Glucose. — The  following  procedure  is 
recommended  for  qualitative  examination  of  urine  for  glucose:  If  the 
urine  be  albuminous » it  is  indispensable  that  the  albumin  be  separated 
before  any  of  the  tests  for  sugar  are  applied.  This  is  done  by  heating 
the  urine  gradually  to  boiling,  with  addition  of  very  dilute  acetic 
acid  as  the  boiling  temperature  is  approached,  heating  until  the 
coagubited  albumin  has  separated  irf  flocks,  and  filtering. 

Nylander-s  modification  of  the  BiBttger  test  (p.  325)  is  then 
applied  to  the  albumin -free  urine,  Tl|is  test  is  preferable  to  the  cop- 
per reduction  tests,  as  it  does  not  react  with  uric  acid,  creatinin  or  the 
glycosu rates  (p.  743),  which  may  reduce  the  copper  reagents.  But 
it  is  open  to  the  objection  tliat  with  urines  voided  after  chloroform 
narcosis  and  with  those  containing  inercury,  whether  from  the  medici- 
nal administration  of  mercurials  to  the  patient  or  from  addition  of 
HgCk  to  the  urine  as  an  antiseptic^  the  reaction,  ^ven  in  the  presence 
of  glucose^  does  not  give  the  characteristic  black  color,  but  at  most  a 
yellow  or  brown.  Therefore,  if  the  Ny lander  reactioJ  give  a  negative 
result,  the  Fehling  test  (p.  324)  is  to  be' resorted  J^p,  An  affirmative 
result  with  the  Xylander  indicates  the  presence  of  glucose*  or  ot  con- 
jugate glucnronates,  other  ketoses  or  aldoses,  or  otRer  reducing  agents 
Negative  results  with  both  Nylander  and  Fehling  indicate  the  absence 
of  sugar.  If  either  reaction  give  au  affirmati\*^  result,  a  further 
examination  by  another  test  is  still  required. 

A  Smith's  fernientation  tube  is  then  filled  with  the  urine  to  which 
yeast  has  been  added,  and  placed  in  an  incubator,  heated  to  about 
37°,  for  twenty -four  liours.  The  efficiency  of  the  yeast  must  be 
assured  by  blank  testing  with  water  and  glucoses  solution  (p.  327). 
If  fermentation  do  not  occur,  glucose*!?  absent.  If  it  do  occur  the 
presence  of  glucose  or  of  some  other  fermentable  sugar,  fructose  or 
maltose,  is  indicated.  If  the  Nylander  test,  appliefrto  the  urine  after 
complete  fernientation,  give  au  affirmative  result,  the  presence  of  a 
reducing  substance,  other  than  a  sugar,  and  accompanying  such  sugar, 
is  indicated. 

riic  presence  of  fructose  is  indicated  by  an  affirmative  reaction 
with  Scliwanoff^s  test  (p,  326),  and  by  either  a  h^vorotation  with  tlic 
polariscope  or  a  lower  quantitative  result  with  the  polariscope  than 


750 


MANUAL    OF    CHEMISTRY 


with  Kuapp's  or  Pebliag's  metuotls  (below).  If  ilie  urine  ferment* 
and  is  dextrorotary,  and  if  the  quantitative  result  obtained  by  the 
polarimeter  be  less  than  that  obtained  by  the  rediietiou  int-tbods, 
both  glucose  and  fnic.tose  are  preseut,  Miiituse  very  rarely  occurs  ia 
uriue,  and  when  it  does  it  is  aeeompanied  by  glin*cise.  It  is  said  that 
glueose  and  nialtose  njay  be  distiuunished  from  eaeh  other  by  the  dif- 
ference in  the  fusing  points  of  their  osa zones,  bur  as  these  fusin 
points  approach  each  other  closely:  204"^  to  205^  and  206^,  this  nieth 
of  distinetion  cannot  be  reliable.  The  yjhenyl hydra zin  test  (p.  32 
may,  however,  be  applied  in  confirmation  of  the  Ny lander  and  fer- 
mentation tests.  It  does  not  react  with  reducing  agents  other  than 
saffars,  nor  with  uric  acid,  ereatinin  or  conjugate  glucunmateis, 
althnugh  it  does  with  free  glucuronic  acid,  which  is,  however,  never 
jiresent  in  urine  _ 

f  Glucose. —  (1)    Btf  the   Pnlarim- 

pie  examination  the  liquid    must    be 

ess,  or  nearly  so.    This  is  accomplished 

ler  organic  liquids  by  isolation  of  tlie 

by  biisie  lead  acetate,  or  by  benzoyl 

and    resohition    in   water.     Either 

the  student  is  referred    to   moi-e 

ir   description.     The   clear,    deecdor- 

itrimeter  (p,  37),  and  the  mean  of 

hVangle  of  deviation.     From  this  the 

d  by  the  formula  ;>=g^^^— J ,  in  which 

ucose  in  1  ec.  of  urine;  a  =^  the  angle 

the  tube  in  decimeters.    The  same  for- 

br  other ^i\}>stanees  by  snbstitnting  for  52.6  the 

at  substatiVa.     Or  a  sacchari meter,  which  is  a  po- 

k»  read  the  percentage  of  glucose  directly,  may 

rine  contain  albumin,  it  must  be  i*eraoved  before 

Ine  of  a. 

method  must  always  be  conti'olled  by  those  of 
xtrorotation  of  ghicose  may  be  dinunished  or 
fructose,  e<ui  jugate  gin  euro  nates,  or 
The  determination  is,  however,  often  of  value  for 
etermi nation  of  these  substances. 
Mfthofl. — This  method,  based  upon  the  reduction  of 
mercuric  cyanid  by  glucose,  is  preferable  to  the  more  commonly  used 
Fehling,  because  the  end  reaction  is  sharper,  and  daylight  is  not 
necessary,  as  it  is  with  the  Fehliug, 

If  the  qualitative  testing  have  shown  the  presence  of  a  reducing 
substance  other  than  glucose  (p.  749) ,  this  must  be  removed  by  Focke's 


if- 


Qyantitative  Determinati 
ffft\~—  F^reparatory  to  polarise 
rendered  transpai'ent  and  colo: 
in  the  case  of  the  urine  and 
sugar,  by  precipitation  eithe 
chlorid,    liberation    of    the 
operation   is  rather    intricate 
comprehensive    treatises    ftjr 
ized  urine  is  obse^ 
half  a  dozen  readi 

percentage  of  sug 

ight,  1 
i;  /  = 
e  us 
foi^ 
tHui 


p  ^=  the 
of  deviati 


inuln   nuiy 
valne  of  [ 
kri  meter 
be   used, 
determining 

The  result 
other  method 
overcome  l)y  tlie 
^-oxybntyrie 
identification 

(2)   KHttpp\^ 


fhc^ 
ijev  orotic 
d^ 


URINE 


751 


method  (p.  324)  before  proeeedhi^  with  either  Kiiapp*s  or  Fohliijg*s> 
fiuantitative  process. 

The  standard  solution  consists  of  10  gms.  of  pure,  crystallized 
mereuric  cyanid  and  100  ee.  of  a  solutioo  of  sodium  hydroxid,  sp.  gr. 
1.145  in  a  liter.  Twenty  cc*  of  this  solution  are  reduced  by  0.05  gm. 
of  glucose.  The  solution  is  used  in  the  same  way  as  Fphlin^'s  solu- 
tion: 20  cc.  of  the  solution  are  diluted  with  80  er.  of  water  and 
heated  in  a  flask  to  boiling.  The  nrine^  diluted  with  water  iu  the 
proportioQ  of  1:4  or  of  1:9,  is  added  from  a  burette,  at  lirst  in 
portions  of  2cc,,  then  of  1  ee»,  then  of  0»5ec,  and  finally  of  0.1  cc. 
As  the  end  reaction  is  approached,  the  liquid  clears,  and  the  mercury 
deposits.  A  drop  of  liquid  is  then  removed  from  time  lo  tiuif  with  a 
capillary  tube,  placed  upon  a  piece  of  filter  paper »  and  held,  first  over 
a  bottle  coutaiuing  strong  hydrochlorie  iu'lt],  tlien  over  one  euutain- 
ing  a  strong  solution  of  hydrogen  sulfid,  until  it  no  longer  assumes 
a  yellow  or  brown  color.  The  calculation  is  the  same  as  with  Feh- 
ling*s  solution,  and  the  result  is  multiplied  by  two.    The  end  rearHon 

(3)  Btj  Ff Ming's  sol nf ton. — ^Ttte  copper  contained  in  20  cc.  of 
Pehling^s  solution  (p.  324)  is  precipitated  by  0,1  gra.  of  glucose. 

To  use  the  solution,  20  cc.  of  the  mixed  solutions  are  placed  iu  a 
flask  of  250-300  cc.  capacity,  80  ee.  of  distilled  water  are  added,  the 
wOioU*  thoroughly  mixed  and  heated  to  boiling.  On  the  other  baud, 
the  urine  to  be  tested  is  diluted  with  four  times  its  volume  of  water 
if  poor  in  sugar*  aud  with  nine  times  its  volume  if  highly  saeehariiie 
(the  degree  of  dilution  required  is,  with  a  little  practice,  determined 
by  the  appearance  of  the  deposit  obtained  in  the  qualitative  testing); 
the  water  and  urine  are  thoroughly  mixed  aud  a  burette  fiUed  with  th^ 
mixture.  A  little  CaCl^  snlutiou  is  added  t^  the  Fehliug^s  solutinT> 
and  the  diluted  urine  added,  iu  small  portions  toward  the  end,  until 
the  blue  color  is  entirely  discharged  —  the  contents  of  the  flask  being 
made  to  boil  briskly  betw^een  additions  fnmi  the  burette.  When 
the  liquid  in  the  flask  show*s  no  blue  color  when  looked  through  with 
a  white  background  in  daylight  the  reading  of  the  burette  is  taken. 
This  reading,  divided  by  five  if  the  urine  was  diluted  with  four  vol- 
umes  of  water,  or  by  ten  if  with  nine  volumes,  gives  the  number  of 
cc.  of  urine  containing  0.1  gram  of  glucose;  aud  consequently  the 
elimination  of  glucose  ia  24  hours,  iu  decigrams,  is  obtained  by 
dividing  the  number  of  cc.  of  urine  in  24  hours  by  the  above  result. 

ErampU, — 20  cc.  Fehling's  solution  used^  and  urine  diluted  with 
four  volumes  of  water. 

Reading  of  burette:  36.5  cc.-^  =7.3  ec.  urine  contain  0.1  gram 

2  436 
glucose.     Patient  is  passing  2,436  cc.  urine  in  24  hours.  -=-g-^333.S 

dceigr.  =33.36  grams  glueose  iu  24  hours. 


752 


MANUAJ.    OF    CHEMISTRY 


(4)  GravimetHc  method. — Wli«:*ii  more  accurate  results  than  are 
obtainable  by  Febliog'S  volumetric  process  are  desired,  recourse 
must  be  bad  to  a  determiimtiou  of  tbe  weig^bt  of  cuprous  oxid  ob- 
tained hy  reduction.  A  small  quantity  of  freshly  prepared  Fehling's 
solution,  diluted  with  four  times  its  volume  of  boiled  water,  is 
heated  to  boiling  in  a  small  flask.  To  it  is  gradually  added,  with 
the  precautions  observed  in  the  volumetric  method,  a  known  volume 
of  the  dilnted  urine,  such  that  at  the  end  of  the  reduction  there  shall 
remain  an  excess  of  unreduced  copper  salt.  The  alkaline  fluid  is 
separated  as  rapidly  as  possible  from  the  precipitated  oxid,  by  decan- 
tation  and  filtration  through  a  small  double  filter,  and  the  precipi- 
tate and  flask  repeatedly  washed  with  hot  H2O  until  the  washings  are 
no  lonjjer  alkaliue.  A  small  portion  of  the  precipitate  remains  adher- 
ing to  the  walls  of  the  flask.  The  filter  and  its  contents  are  dried 
and  burned  in  a  w^eighed  porcelain  crucible*  When  this  has  cooled, 
tlie  flask  is  rinsed  out  with  a  small  quantity  of  HNO3;  which  is  added 
to  the  eonteots  of  the  crueilile,  evaporated  over  the  water -bath*  the 
crucible  slowly  heated  to  redness,  cooled,  and  weighed.  The  diflfer- 
ence  between  this  last  weight  and  that  of  the  crncible  +  that  of  tbe 
filter-ash,  is  the  weight  of  cupric  oxid,  of  which  220  parts  =  100 
parts  of  glucose.  Or  better,  the  cupric  oxid  is  dissolved  in  a  little 
dilute  uitric  acid,  the  solution  evaporated  with  a  little  sulfuric  acid, 
the  residue  redissolved,  and  the  copper  determined  electrolyticallys 
175.6  Cu.^^100  glucose. 

(5)  By  specific  gravity;  Eoherfs  7ueihod, — ^The  sp.  gr,  of  the 
urine  is  carefully  determined  at  25*^  (77^^  F.);  yeast  is  then  added. 


■ 


and  the  mixture  kept  at  25 


(77° 


F.)  until  fermentation  is  complete; 


the  sp.  gr.  is  again  observed,  and  will  be  found  to  be  lower  than 
before.  Each  degree  of  diminution  represents  0.2196  gram  of  sngar 
in  100  cc.  of  urine. 

Other  Sugars  —  Lmvulose  (fructose)— sometimes  occurs  in  dia* 
betic  urine.  When  it  is  present  the  urine  responds  to  the  tests 
for  glucose,  but  it  either  rotates  to  tbe  left  or  has  a  dextrogrratorj* 
action  less  than  that  required  by  the  result  of  the  quantitative  re- 
duetion  methods. 

Lactone  occurs  in  the  urine  after  the  ingestion  of  large  quantities 
of  milk-sugar,  and  sometimes  in  the  urine  of  women  during  the  later 
stages  of  gestation  and  diu'ing  lactation.  Its  presenre  may  be  in- 
ferred when  the  urine  reacts  with  the  copper  and  bismuth  tests, 
but  gives  negative  results  with  tbe  fermentation  test. 

Maltose  rarely  acompanies  glucose  in  pancreatic  diabetes. 

Laiose  is  a  substance  wiiieh  oc<*urs  in  the  urine  in  some  cases 
of  diabetes.  It  is  lan^ogyrous  and  amorphous,  it  i-eduees  the  com- 
pounds of  copper  and  of  bismuth,  does  not  ferment,  and  forms  a 


UKINE 


753 


yellow  or  brown  oily  material  with  phenylhydrazin.  It  is  supposed  to 
be  a  sugar. 

Pent&S€s  (p.  310)  have  beeti  met  with  iu  large  amount  in  the 
uriue  of  persons  addieted  to  the  morphin  habit,  in  whom  there  is 
an  alternation  of  glycosuria  and  peutosnria.  The  pentoses  ai**  de- 
tected by  ToUens*  reaction:  the  urine  is  mixed  with  an  equal  volume 
of  strong  hydrochloric  acid*  a  little  phloroglucin  is  added,  and  the 
liquid  heated  by  immersion  in  a  boiling  water -bath.  A  red*  violet 
€olor  indicates  the  presence  of  pentoses,  galactose,  lactose,  or  glncii- 
ronie  acid.  To  distinguish  between  these  the  liquid  is  examined  with 
the  spectroscope,  when,  in  the  presence  of  pentoses  or  of  glucuronic 
acid,  a  band  is  seen  in  the  green,  between  D  and  E,  The  pentoses 
and  glucuronic  acid  may  be  distinguished  by  the  fusing  points  of 
their  osazones,  that  of  glucuronic  acid  fusing  at  115*^,  and  those 
of  the  pentoses  at  a  higher  temperature,  160°, 

Inosite,  muscle  sugar,  is  a  cyclic  alcohol,  CflHa(OH)a,  which 
Foccurs  in  traces  in  normal  urine,  and  in  increased  amount  in  albu- 
minuria, in  diabetes  insipidus,  and  after  ingestion  of  large  quantities 
of  water. 

Acetone  Bodies. — Three  substances  are  included  under  this  head, 
which  are  evidently  successive  products  of  the  same  process.  They 
are  /3-oxy butyric  acid,  CHa.CHOH,CH2.CO0H,  acetylacetic  acid, 
CH2,CO.CH3.COOH,  and  acetone,  CH^.CO.CHa.  Clearly  acetylacetic 
acid  is  a  product  of  oxidation  of  i3-oxybutyric  acid,  and  this  in  turn 
yields  acetone  by  loss  of  CO2.  The  oxybutyric  acid  is  the  It^vo  acid. 
Of  these  substances  acetone  is  constantly  present  in  normal  urine, 
the  daily  elimination  being  from  O.TOl  to  0.01  gm.;  acetylacetic  acid 
fuay  be  present  without  ^3- oxybutyric  acid,  but  never  without  acetone, 
and  ^-oxybutyric  acid  never  occurs  in  normal  urine.  Probably  the 
occurrence  of  these  substances  in  these  relations  indicates  varying 
degrees  of  interference  with  a  normal  process  of  oxidation  through 
them.  When  acetone  bodies  are  present  in  the  urine  in  quant  it  ies 
greater  than  the  normal  traces  the  symptom  is  known  as  acetonuria. 
When  acetonuria  exists  acetone  is  also  eliminated  by  the  lungs, 
and,  when  present  in  sufficient  amount,  communicates  a  peculiar, 
sweet,  apple -like  odor  to  the  breath.  The  condition  of  acetonuria  is 
accompanied,  except  in  the  rabbit,  by  a  notable  increase  in  the  per- 
centage elimination  of  anmionia,  which  may  rise  as  high  as  35  to  40 
per  cent  of  the  total  nitrogen.  Acetonuria  occurs  in  normal  individ- 
uals, particularly  stout  persons,  with  deprivation  of  food,  in  febrile 
disc^ases  when  the  febrile  condition  is  prolonged,  iu  certain  mental 
diseases,  such  as  general  paresis,  melancholia  and  epilepsy,  after 
chloroform  tiarcosis,  in  puerperal  eclampsia,  and  in  diabetes. 

In  considering  the  origin  of  these  substances,  the  probability  of 

48 


754  MANUAL    OF    CHEMI8TEY 

their  being  derived  from  Uie  carbohydrates  woujd  first  auggest  itself, 
bat  pronounced  acetonnria  frequently  occurs  in  diabetics  from  whose 
diet  carbohydrates  are  exelndedy  and  in  these  patients,  as  well  as  in 
other  forms  of  acetonnria,  the  condition  may  be  diminished  in  inten- 
sity, or  even  entirely  removed,  by  adding  carbohydrates  to  the  diet; 
and  acetonuria  is  developed  in  diabetics  by  complete  exclusion  of 
carbohydrates  from  the  food. 

The  increased  elimination  of  ammonia  in  acetonuria  indicates  a 
disturbance  in  the  protein  metabolism,  probably  a  failure  on  the  part 
of  the  liver  to  convert  ammonia  into  urea.  But  the  appearance  of 
the  acetone  bodies  in  the  urine  is  not  an  indication  of  increased  pro- 
tein decomposition,  as  the  total  nitrogen  is  not  increased  during  fast- 
ing, but  is  diminished,  while  that  of  the  acetone  bodies  is  increased. 
It  has  also  been  observed  that  a  diabetic  may  remain  in  nitrogenous 
equilibrium,  or  may  even  gain  nitrogen,  without  the  degree  of  ace- 
tonuria being  affected.  In  one  observed  case,  a  diabetic  with  a  protdn 
consumption  of  262  gms.  in  three  days,  eliininated  842  gma.  of 
/3-oxybutyric  acid. 

But,  while  the  manner  and  degree  in  which  the  proteins  are  eon- 
cemed  in  acetonuria  are  undetermined,  there  is  positive  evidence  that 
the  condition  depends  to  a  great  degree  upon  fat  consumption,  and 
that  it  occurs  in  conditions  in  which  the  organism  is  burning  its  own 
fat  deposits.  This  is  certainly  true  in  inanition  under  ordinary  etm- 
ditions,  and  it  has  been  shown  that  the  increased  elimination  of 
acetone  bodies  by  women  in  the  puerperal  state  is  pronounced  in  Hi 
women,  but  not  in  those  having  little  fat  reserve.  While  addition  of 
proteins  or  of  carbohydrates  to  the  diet  in  acetonnria  may  diminish 
the  amounts  of  acetone  bodies  eliminated,  the  contrary  result  follows 
the  addition  of  fats. 

The  occurrence  of  acetone  bodies,  and  notably  of  acetylacetic  and 
jS-oxybutyric  acids  in  the  blood   in  diabetes  and   other  conditions 
attended    with   acetonaemia   was   supposed    to  produce   acidism  or 
acidosis,  by  which  the  normal  and  necessary  alkalinity  of  the  blood 
was   diminished.     Usually,    however,    this   does  not   occur,   as  the 
ammonia  also  produced  neutralizes  the  acids,  and  prevents  their  action 
upon  the  blood  alkalies.    This  is  shown  to  be  the  case  by  the  fact  that 
rabbits,  in  which  the  attendant  formation  of  ammonia  does  not  oecnr, 
are  exceedingly  susceptible  to  the  form  of  poisoning  referred  to  as 
acidism,  and  in  them  the  symptoms  of  increasing  dyspnoea,  subnormal 
temperature,  somnolence,  coma,  and  convulsions  may  be  developed 
by  merely  withholding  food  capable  of  producing  alkalies.    There  may 
also  occur  a  sudden  and  sufficiently  excessive  formation  of  these  sub- 
stances  in   diabetics   as   the  similarly  operating  cause  of  the  like 
symptoms  which  occur  in  diabetic  coma. 


URINE 


755 


Tests  for  the  Acetone  Bodies. — As  acetylacetic  acid  is  decom- 
posed, with  foruuition  of  aeetoue,  by  simple  heating  of  the  urine,  this 
must  first  be  tested  foi%  and  removed,  if  present,  before  examining  for 
acetone, 

Acetylacetic  AckL—H)  Arnold' a  Te.st:  The  reagent  is  in  two  so- 
lutions;  One  a  1  per  cent  solution  of  sodium  nitrite,  the  other  a  so- 
lution made  by  dissolving  1  gm.  of  para-amidoacetophenone  in  100  cc. 
of  water,  and  adding  HCl  until  the  yellow  liquid  becomes  colorless. 
One  volume  of  the  first  solution  is  mixed  with  two  of  the  second  to 
produce  the  reagent.  Equal  volumes  of  the  reagent  and  the  urine  are 
shaken  together  and  a  few  drops  of  ammonia  are  added,  when  au 
amorphous  reddish -brown  precipitate  is  produced,  which  develops  a 
ptirple- violet  color  when  the  mixture  is  treated  with  10  to  12  volumes 
of  eoucentrated  HCl. 

(2)  Qerhardfs  Test:  Add  dilute  solution  of  neutral  ferric  chlorid 
80  long  as  a  precipitate  (of  phosphates)  is  fonned,  filter,  and  add  more 
ferric  chlorid  solution,  a  wine -red  '*olor  is  produced  if  acetylacetic 
acid  be  present.  If  the  result  be  affirniaHve  it  should  be  confirmed 
by:  (1)  Render  a  portion  of  the  urine  faintly  acid.  boiL  cool,  and 
repeat  the  test,  which  should  give  a  negative  result;  (2)  acidulate 
another  portion  with  dilute  sulhirii*  acid,  agitate  with  ether,  and  then 
agitate  the  separated  ether  w*ith  dilute  ferric  chlorid  solution,  which 
should  be  colored  wiue-red. 

Acetone, — If  thei*e  be  no  acetylacetic  acid  present  the  urine  is  tested 
for  acetone  as  directed  below,  but  if  it  be  present  the  urine  is  rendci-ed 
faintly  alkaline,  agitated  iu  a  separator  with  a  mixture  of  alcohol  and 
ether,  the  ether  separated,  agitated  with  water,  and  the  ivaier  tested 
for  acetone  by  the  tests  given  below.  In  the  absence  of  acetylacetic 
acid  a  liter  of  the  urine  is  acidulated  by  addition  of  1  gm.  of  phos- 
phoric acid,  and  distilled;  30  cc.  of  distillate  being  collected  and 
tested  by: 

(1)  fjf ben's  Imloform  Tfsl. — Add  caustic  soda  and  a  little  solu- 
tion of  iodiu  in  potassium  iodid,  and  warm:  the  odor  of  iodoform  i.s 
produced,  and  a  yellow,  crystalline  precipitate,  if  the  quantity  be 
sufficient.  Also  reacts  with  alcohol.  Or  iTunning's  modification  of 
this  test»  which  has  the  advantage  of  not  reacting  with  alcohol  or 
aldehyde,  may  be  used:  An  alcoholic  solution  of  iodin  and  ammonia 
are  used  in  place  of  the  aqueous  iodiu  solution,  which  causes  the 
formation  from  acetone  of  iodoform  and  the  black  nitrogen  iodid, 
which  latter  gradually  disappears  on  standing,  leaving  the  iodoforuK 

(2)  LeguVs  Nitroprnssid  Test. — Add  a  few  drops  of  a  freshly  prt- 
pared  solutiou  of  sodium  uitroprnssid,  and  then  KHO  or  NallO 
solution »  when,  iu  presence  of  acetone,  the  liquid  is  colored  ruby- 
red,   and,  oil   supersatnratiou   with   acetic  acid,   changes  to  pui'ple. 


756  MANUAL  '  OP    CHEMISTRY 

Paracresol  gives  a  yellow -red  color,  which  changes  to  yellow  with 
excess  of  acetic  acid.  Creatinin  gives  an  initial  color  with  this  test 
similar  to  that  produced  by  acetone,  but  on  addition  of  acetic  acid, 
it  turns  to  yellow,  and  slowly  to  green  or  blue.  But  creatinin  can- 
not be  the  source  of  error  if  the  urine  has  been  distilled  as  above 
directed. 

(3)  Reynold^ 8  Mercuric  Oxid  Test — is  based  upon  the  property  of 
acetone  to  dissolve  freshly  precipitated  mercuric  oxid.  Mercuric  oxid 
is  precipitated  from  a  solution  of  mercuric  chlorid  by  ad<lition  of  an 
alcoholic  solution  of  potassium  hydroxid,  and  a  portion  of  the  distil- 
late is  added  to  the  mixture,  which  is  then  strongly  shaken  and 
filtered.  The  formation  of  a  black  precipitate  by  addition  of 
ammonium  sulfid  to  the  filtrate  indicates  that  it  contains  dissolved 
mercuric  oxid. 

(4)  Pemold^s  Indigo  Test. — Add  a  portion  of  the  distillate,  and 
then  NaHO  solution  to  solution  of  orthonitrobenzaldehyde,  pre- 
pared by  making  a  hot  saturated  solution  and  cooling  it,  when,  m 
presence  of  acetone,  the  liquid  turns  yellow,  then  green,  and  finally 
deposits  indigo -blue.  If  chloroform  be  then  shaken  with  the 
mixture  it  forms  a  blue  solution  at  the  bottom  of  the  test-tube. 

The  principle  of  Lichen's  reaction  is  utilized  in  the  Messinger- 
Huppert  method  of  quantitative  determination  of  acetone,  the  amount 
being  calculated  from  the  quantity  of  iodin  used  in  the  fonnation  of 
iodoform. 

P'ozyhutyric  Acid, — ^An  examination  for  this  acid  is  not  called  for 
except  acetylacetic  acid  have  been  found  to  be  present.  In  that  event, 
if  the  urine  be  Icevorotary  after  complete  fermentation,  the  presence  of 
^-oxybutyric  acid  is  probable.  Kulz^s  Method,  based  upon  the 
dehydration  of  this  acid  to  crotonic  acid:  CH3.CHOH.CH2.COOH= 
CH3.CH:CH.COOH+H20  is  then  to  be  used:  The  fermented  urine  is 
evaporated  to  a  syrup,  an  equal  volume  of  concentrated  H2SO4  is 
added,  and  the  mixture  distilled.  The  distillate  on  cooling  deposits 
crystals  which,  after  drying,  fuse  at  71-72°.  If  no  crystals  are 
deposited  the  distillate  is  extracted  by  agitation  with  ether,  the 
ethereal  solution  evaporated,  and  the  f.  p.  of  the  residue  determined. 

Amido  Acids. — The  question  whether  amido  acids  may  normally 
be  present  in  the  urine  has  been  much  discussed.  Until  quite  recently 
the  only  member  of  the  class  which  has  certainly  been  extracted  from 
normal  urine  was  glycocoll.  But,  as  the  process  of  its  extraction 
involved  long  heating  with  alkaline  solutions,  it  may  be  questioned 
whether  the  amido  acid  did  not  result  from  decomposition  of  hippuric 
acid.  It  is  quite  within  the  possibilities,  however,  that,  as  a  synthesis 
of  hippuric  acid  from  glycocoll  and  a  benzoyl  derivative  takes  place  in 
the  kidneys,  one  constituent  might  under  normal  conditions  be  present 


URINE 


751 


in  sufficient  excess  to  be  eliuiiuated.  Recently  a  substance  Las  been 
obtfiiued  from  iiormal  urine  by  the  J^-naplitbalenesullocblorkl  method 
which  had  the  crystalline  form  of  leucin  and  produced  a  copper  com- 
pound  having  the  characters  of  that  of  leucin.  The  question  must  be 
considered  as  still  open. 

The  two  patholotjical  conditions  in  which  amido  acids  occur  in  the 
urjue  are  yellow  atrophy  of  the  liver  and  acute  phosphorus  poisoning^ 
ill  both  of  which  there  is  extensive  disorganization  of  liver  tissue. 
The  two  amido  acids  which  first  attracted  attention  in  this  conneetiou 
were  leucin  and  tyrosiu,  which  have  also  been  said,  upon  evidence 
which  must  be  considered  as  insufficient,  to  occur  in  the  urine  in  other 
pathological  conditions,  as  in  typhoid  and  in  variola.  The  presence 
of  leucin  and  tyrosin  has  usually  been  predicated  upon  the  occurrence 
of  certain  crystals  or  nodules  in  the  urinary  deposits.  It  has  been 
shown,  however,  that,  while  these  may  in  some  instances  consist  of 
leucin  or  tyrosin,  they  do  not  always,  and  therefore  their  occurrence 
is  insufficient  evidence  of  the  presence  of  these  substances. 

The  presence  of  tyrosin,  and  of  tyrosin,  leucin  and  glycocoll,  in 
the  urine  in  acute  phosphorus  poisoning  has  been  demonstrated  hy 
more  modern  methods  in  several  instances,  and  in  a  recent  case 
tyrosin,  leucin,  alanin,  glycocoll  and  argiuiu  were  found  and  identi- 
tied:  tyrosin  by  its  crystalline  form  and  response  to  the  Millou  reaction, 
leucin  and  alanin  by  the  appearance  and  analysis  of  their  copper 
derivatives,  glycocoll  by  the  f.  p,  (156*^),  crystalline  form  and  nitrogen 
content  of  its  ^-naphthalenesulfo  compound,  and  argiuiu  by  the  crys- 
talline form  and  f.  p,  (225**)  of  its  picrolonate. 

In  a  case  of  cj^stinuria  tjTOsin  and  leucin  have  been  found  in  the 
urine,  the  former  identified  by  its  crystalline  form,  response  to  tlie 
Millon  reaction  and  C  and  H  content,  the  latter  by  the  f.  p.  (67°)  and 
analysis  of  its  ^-naphthalenesnlfo  compound. 

The  separation  and  identification  of  amido  acids  is  now  usually 
made  by  Fischer  and  BergelFs  method,  or  one  of  its  modifications, 
which  depends  upon  the  fact  that  amido  acids  enter  into  reaction  in 
presence  of  alkalies  with  ^-naphthalenesulfochlorid  to  form  crystalline, 
difficultly  soluble  compounds,  of  the  type  of  /S-naphthalenesulfoglycin: 
CioH7.S02.HN,CH2.COOH,  which  correspond  in  structure  to  hippurie 
acid  and  other  benzoyl*  etc.,  derivatives  of  amido  acids  (p.  480). 
Another  method  of  separation  of  amido  acids,  devised  by  Fischer,  con- 
sists of  their  conversion  into  their  esters,  and  the  fractional  distilla- 
tion of  these.  The  details  of  these  methods  are  too  intricate  to  b© 
considered  here. 

Cystin^ — a.*diamido — fi- (Hi hiodi lactic  acid — ^was  first  obtained  from 
a  rare  form  of  urinary  calculus  (p,  759),  and  has  since  been  shown 
to   be  identical   with  the  cyslin  obtained   by  hydrolysis  of  proteins 


758  MANUAL    OF    CHEMISTRY 

(p.  421,  580),  it  having  been  demonstrated  that  ''calculus  cystin"  and 

"protein  cystin"  are  not  two  isomeric  forms,  but  one  and  the  same 

substance.    Cystin  occurs  in  the  normal  urine  in  small  quantity,  and 

is  greatly  increased  in  amount  in  the  uncommon  condition  of  cystin- 

uria,  when  it  forms  yellowish  sediments  in  the  urine,  containing  its 

characteristic  crystals  (Pig.  46).    The  quantity  of  cystin  produced  in 

this  condition  is  sometimes  so  great  that,  by  reason  of  its  sparing 

solubility,  it  is  deposited  in  the  tissues  in  sufScient 

amount  to  cause  death  by  inanition.    In  some  cases 

of  cystiuuria  the  urine  also  contains  the  diamins,  pu- 

troscin  and  cadaverin,  in  others  it  does  not.     Leucin 

and  tyrosin  have  been   found   to  accompany  cystin 

^K,.   ^ — ^      ■   ^"  ^^®  ^^^^  ^^  cyslinuria,  and  it  seems  probable  that 

ry    y^         the   substance   described   as   "calculus  cystin"   was 

^^    ^T^      tyrosin.     Several  cases  of  cystiuuria  have  been  care- 

^^^       fully  studied  from  the  chemical  standpoint  in  recent 

years,  but  the  investigations  have  led  to  little  definite 

knowledge  of  the  chemism  of  this  obscure  form  of  disturbance  of 

protein  metabolism. 

Cystin  is  best  separated  from  the  urine  and  determined  by  pre- 
cipitation with  benzoyl  chlorid  by  Baumann  and  Goldmann's  method, 
or,  less  exactly,  by  precipitation  by  strong  acidulation  with  acetic 
acid  and  purification  of  the  precipitate  by  reprecipitation  from  a  solu- 
tion in  ammonia. 

URINARY   CALCULI. 

Urinary  calculi,  or  concretions,  may  be  formed  in  any  part  of  the 
urinary  tract,  but  are  most  frequently  formed  in  the  pelvis  of  the 
kidney  or  in  the  bladder.  They  are  usually  single,  but  may  be  mul- 
tiple, as  many  as  300  having  been  found  in  the  bladder  at  one  time. 
When  multiple,  their  surfaces  are  usually  polished  and  formed  into 
facets  by  mutual  attrition.  They  vary  in  size  from  mere  gravel  to 
masses  as  large  as  a  hen's  egg,  and  weighing  as  much  as  1,500  gms. 
Calculi,  other  than  phosphatic  and  ammonium  urate  concretions,  are 
usually  composed  of  the  same  material  throughout,  constituting 
'^primary  deposits."  Phosphatic,  ammonium  urate,  and,  very  rarely, 
calcium  carbonate  calculi  are  produced  as  "secondary  deposits,"  being 
formed  in  an  alkaline  or  subacid  urine,  as  a  so-called  "crust,"  which 
frequently  constitutes  almost  the  entire  mass  of  the  stone,  by  deposi- 
tion upon  a  "nucleus,"  or  nuclei,  consisting  either  of  a  priman' 
deposit  or  of  some  foreign  substance.  The  constituents  of  urinary 
calculi  most  frequently  met  with  are  uric  acid,  sodium  urate,  ammo- 
nium urate,  calcium  oxalate,  calcium  phosphate  and  ammonio-ning- 
nesian    phosphate:    those   of    rarer   occurrence   are   cystin,  xanthin. 


URINARY    CALCULI  759 

orates  of  potassium,  calcium  and  magnesium,  and  calcium  carbonate. 
Of  very  exceptional  occurrence  are  calculi  of  indigo,  silica,  fatty 
acids  (urostealiths),  and  bilirubin  (biematoidin). 

Uric  acid  calculi  are  usually  small  in  size,  and  of  renal  origin, 
although  they  are  met  with  as  vesical  calculi  of  gi-eat  size.  They 
are  always  produced  in  a  strongly  acid,  concentrated  urine.  They 
are  gray,  brownish-yellow  or  reddish-brown  in  color,  sometimes 
smooth -surfaced,  but  usually  finely  nodulated,  and  quite  hard.  They 
are  almost  always  primary,  although  occasionally  uric  acid  forms 
alternate  laj-ers  with  calcium  oxalate  in  a  composite  stone. 

Ammonium  urate  is  sometimes  met  with  as  a  primary  deposit 
in  renal  calculi  in  young  children,  which  are  smooth,  yellow,  oval 
in  section  and  relatively  soft  and  friable.  Much  more  frequently 
ammonium  urate  constitutes  a  secondary  deposit. 

Oxalate  calculi  are  occasionally  small  and  smooth,  more  usually 
very  rough  and  coarsely  nodulated,  very  hard,  and  varying  in  color 
from  very  pale  yellow  to  dark-brown.  They  ai*e  known  as  "mulberry 
calculi"  from  their  shape. 

Phosphatic  calculi  are  almost  invariably  secondary  deposits,  and 
consist  usually  of  a  mixture  of  calcium  phosphate,  ammonio-magnc- 
sian  phosphate  and  ammonium  urate.  They  may  attain  great  size, 
are  always  rough -surfaced,  white  to  yellowish  or  pink  in  color,  and 
relatively  soft  and  friable.  Calculi  whose  predominating  constituent 
is  ammonio-magnesiau  phosphate  are  called  ^'lusible  calculi." 

Cystin  calculi,  although  rarely  met  with,  are  of  more  frequent 
occurrence  than  the  other  "rare"  forms.  They  are  primary,  yellow, 
smooth  or  rough,  of  crystalline  structure  throughout,  consisting 
entirely  of  cystin,  quite  soft,  and  usually  small,  although  they  have 
been  known  to  attain  the  size  of  an  egg.  Xanthin  calculi  are  of 
very  rare  occurrence.  They  are  primary,  and  consist  either  entirely 
of  xanthin,  or  of  xanthin  and  uric  acid.  They  vary  in  color  from 
pale  yellow  to  brown,  and  are  sometimes  as  large  as  a  pigeon's  egg. 
Urates  of  potassium,  calcium  and  magnesium  are  occasionally  met 
with  in  urate  calculi,  never  as  the  sole  constituents.  Caloir.m  car- 
bonate, while  frequently  met  with  as  a  secondary  deposit  in  calculi 
of  large  size  in  the  lower  animals,  is  very  rarely  found  in  the  human 
subject,  in  the  crust  of  a  calculus  formed  with  a  foreign  body  as  a 
nucleus  or  in  a  siliceous  calculus.  Urostealiths  consist  either  entirely 
of  fatty  acids  with  a  little  phosphate,  or  are  covered  with  a  crust 
of  phosphates,  produced  as  a  secondary-  deposit.  In  the  former  case 
they  are  of  the  consistency  of  India-rubber  when  moist,  but  become 
hard  and  brittle  when  dry.  Only  five  such  calculi  have  been  de- 
scribed. Indigo  was  found  to  be  one  constituent  of  a  calculus 
weighing  40gms.  formed  in  the  pelvis  of  a  kidney.      Blue  crystals 


760  MANUAL   OF   CHEMISTBT 

of  indigo  have  also  been  met  with  inclosed  in  oxalate  caleoli.  Siliea 
ealcnii  are  eztiemely  rare.  The  author  has  seen  the  nndeas  of  a 
phosphaUc  calcolns  consisting  entirely  of  siliea  and  an  oxid  of 
iron.  An  oxalate  calcnlns  has  been  found  to  contain  crystals  of 
hcematoidin. 

For  the  chemical  examination  of  calculi  the  stone  should  be  sawed 
in  two*9  the  sawdust  affording  sufficient  material  for  diemioal  exam* 
ination.  The  sawdust  from  the  central  portions  of  the  calculus 
should  be  collected  and  examined  separately  from  that  dmved  from 
the  crust.  The  following  scheme  of  analysis  will  be  found  useful  for 
the  examination  of  calculus  dust,  a  separate  portion  of  the  material 
being  used  for  eaeh  operation,  except  where  otherwise  directed : 

SOHXICX    FOB    DSTBBMIMINa   THE    COICPOSITION    OF    tfBINABr 

GALOUIJ. 

1.  Heat  a  portion  on  platinum  foil : 

a.  It  is  entirely  volatile 2 

b.  A  residue  remains & 

2.  Moisten  a  portion  with  EQ^Qsi  evaporate  to  dryness  at  low  heat; 

add  NHiHO : 

a.  A  red  color  is  produced .  • 9 

h.  No  red  color  is  produced • •  •  .  .     4 

8.  Treat  a  portion  with  EHO,  without  heating : 

a.  An  ammoniacal  odor  is  observed Ammonium  uraU. 

b.  No  ammoniacal  odor Uric  acid. 

4.  a.  The  HNO3  solution  becomes  yellow  when  evaporated;  the  yel- 

low residue  becomes  reddish -yellow  on  addition  of  EHO, 

and,  on  heating  with  EHO,  violet -red Xanihin. 

b.  The  HNOs  solution  becomes  dark  brown  on  evaporation, 

Cystin. 

5.  Moisten  a  portion  with  HNOs;  evaporate  to  drsrness  at  low  heat; 

add  NH4HO  : 

a.  A  red  color  is  produced 6 

6.  No  red  color  is  produced 9 

6.  Heat  before  the  blow -pipe  on  platinum  foil : 

a.  Fuses 7 

6.  Does  not  fuse    ...      8 

7.  Bring  into  blue  flame  on  platinum  wire  : 

a.  Colors  flame  yellow Sodium  urate. 

6.  Colors  flame  violet Pot€issium  urate. 


URINARY    CALCULI 


761 


8.  The  residue  from  6: 

a.  Dissolves  in  dil.  HCl  with  efferveseence;  the  solution  forms  a 
white  ppt.  with  ammonium  oxalate        ....  Calrrum  wm/f^ 

6.  Dissolves  with  slight  efferveseence  in  diL  HoSOi;  the  solatioii, 
neutralized  with  NH4HO,  gives  a  white  ppt.  with  HNrt2F04, 

MagtiPsium  nrutf\ 

9,  Heat  before  the  blow-pipe  on  platinum  foil  : 

a.  It  fuses .,..•-.   Amnionio-nmgnesian  phosphate, 

h.  It  does  not  fuse  ..*... 10 

10.  The  residue  from  9,  when  moistened  with  H2O,  is  : 

a.  Alkaline 11 

h.  Not  alkaline  , THcaMe  phosphate^ 

11,  The  original  substance  dissolves  in  HCI : 

a.  With  efferveseence ,  .  Caleium  carbonate, 

h.  Without  effervescence Cakium  oxulaie. 


MILK 

As  the  milk  of  the  cow  has  been  the  best  studied,  and  as  it  is  an 
important  article  of  food,  it  will  be  first  coDsidered,  and  the  difference 
between  it  and  human  milk  will  be  subsequently  referred  to. 

Physical  Properties* — Milk  is  white,  yellowish,  or,  in  thin  layers, 
or  if  diluted  with  water,  bluish.  It  is  opaque,  the  opacity  being 
due  to  the  fact  that  it  is  an  emulsion,  and  that  light  is  extinguished 
by  the  repeated  refractions  in  passing  between  the  watery  liquid  and 
the  oil  globules.  Consequently,  the  richer  the  milk  is  in  fat,  the 
thinner  the  layer  in  which  it  is  capable  of  causing  a  certain  degree 
of  extini*tion  of  light;  a  fact  which  is  utilized  in  some  forms  of 
**  milk -testers."  The  odor  of  milk  is  faint^  but  characteristic,  and 
its  taste  is  sweetish. 

Its  reaction  when  fresh  is  amphoteric,  the  mean  alkalinity  being 
equivalent  to  41  cc.  N/lO  NaHO  for  100  cc.  milk  (phenolphthalein), 
and  its  mean  acidity  equivalent  to  10.5  cf'.  N/IO  H2SO4.  In  air  the 
reaction  soon  turns  to  acid,  by  reason  of  formation  of  lactic  and  suc- 
cinic acids  from  the  milk-sugar  by  micro-organisms,  a  change  which 
takes  place  during  the  "souring"  of  milk,  and  has  an  influence  upon 
the  action  of  heat  upon  it.  Fresh  milk  does  not  coagulate  upon 
boiling,  e%^en  after  treatment  with  carbon  dioxid.  As  it  gradually 
sours,  it  first  coagulates  on  boiling  after  treatment  with  COi;;  then 
on  boiling  alone;  at  a  later  stage  it  coagulates  by  the  action  of  CO2 
at  the  ordinary  temperature;  and,  finally,  it  coagulates  spontaneously, 
without  CO2  or  heat,  expressing  a  yellowish  liquid,  the  whey.     This 


762  MANUAL    OF    CHEMISTRY 

change  is  due  to  bacterial  action,  and  may  be  prevented  by  sterilizing 
the  milk  by  heat,  or  by  antiseptics. 

The  specific  gravity  of  cow's  milk  varies  from  1027  to  1035,  being 
higher  with  skimmed  milk,  uud  lower  with  very  rich  milk  and  with 
watered  milk.  The  lactometer  is  simply  a  specially  graduated 
spindle  by  which  the  sp.  gr.  of  the  milk  is  determined,  and  milk 
having  a  sp.  gr.  below  1027  is  considered  as  adulterated.  It  must  be 
remembered,  however,  that  as  the  specific  gravity  is  raised  by  skim- 
ming and  lowered  by  watering,  tlie  original  sp.  gr.  may  be  main- 
tained by  practicing  both  forms  of  adulteration  to  suitable  degrees; 
and  also  that  very  rich  milk  has  a  lower  sp.  gr.  than  that  less  rich 
in  oream.  Therefore,  the  lactometer  can  only  be  i*elied  upon  when 
used  in  connection  with  the  creamometer,  or  other  means  of  deter- 
mining the  proportion  of  fat.  The  average  sp.  gr.  of  good  cow's  milk 
is  1030,  and  the  percentage  of  cream  13. 

Composition. —  Milk  consists  of  a  watery  solution  of  proteins, 
lactose  and  mineral  salts,  sometimes  called  the  plasma,  which  holds 
in  suspension  minute  globules  of  fat,  sometimes  called  the  corpus- 
cles. On  standing,  the  fat  rises,  more  or  less  completely,  to  the 
surface,  forming  a  layer  much  richer  in  fat  than  the  milk,  which  is 
the  cream,  upon  removal  of  which  the  skim-milk  remains.  The 
separation  of  fat  is  more  rapidly  and  completely  effected  by  cream- 
separators,  which  are  centrifugal  machines  adapted  to  this  purpose. 
The  "corpuscles,"  which  contain  all  the  fat  of  the  milk,  number 
from  1  to  5%  million  per  cc,  and  are  from  .0024  to  .0046  mm.  in 
diameter.  It  is  probable  that  the  fat -globules  of  milk  are  enclosed 
in  an  envelope,  because,  unless  the  milk  have  been  previously  treated 
with  alkali,  agitation  with  ether  does  not  readily  extract  the  fat,  and 
also  because  the  globules  are  stained  by  certain  agents  which  do  not 
stain  fats.  Besides  fat,  the  globules  contain  small  quantities  of 
lecithins,  cholesterol,  and  a  yellow  coloring- matter.  The  fat  of  milk, 
butter-fat,  is  more  complex  in  composition  than  other  fats  and  oils, 
from  which  it  differs  particularly  in  containing  a  larger  propor- 
tion of  the  glyeerids  of  the  lower,  volatile,  fatty  acids,  a  fact 
which  is  taken  advantage  of  for  the  detection  of  adulterations 
of  butter.  Milk -fat,  when  saponified,  yields  about  94%  of  fatty 
acids,  of  which  86  to  89%  consists  of  insoluble,  non- volatile 
acids,  palmitic,  stearic  and  oleic,  with  minute  quantities  of  capryhe, 
capric,  lauric  and  arachic  acids  (p.  333),  the  oleic  acid  constituting 
from  A  to  A  of  the  whole.  The  remaining  5  to  8%  consist  of 
soluble,  volatile  acids,  butyric  (f  to  7)  and  caproic  (f  to  f).  Other 
fats  and  oils  yield  only  mere  traces  of  volatile,  soluble  acids  on 
saponification.  Whether  these  acids  exist  in  milk  and  butter  as 
separate  glycerids,  such  as  trii)u;yrln,  03115(0411702)3,  tripalmitin, 
C3H5(Ci6H3i02)3,  and  tristearin,  C3H5(0i8H35O2),  or  as  mixed  gly- 
cerids, such  as  03Hr,(04H702)(OioH3i02)(Oi8H3502).  is  unknown. 


MILK  763 

Butter.— Ck)od,  natural  butter  contains  80  to  90%  of  butter-fat, 
6  to  10%  of  water,  2  to  5%  of  curd  (casein),  2  to  5%  of  salt,  and, 
almost  always,  some  artificial  "butter-color."  About  the  only  adul- 
teration of  butter  now  practiced  is  by  admixture  of  other  animal 
fats  (beef  or  mutton  tallow),  and  vegetable  or  animal  oils  (cotton- 
seed or  lard-oil),  or  by  substitution  of  imitation  butter.  Oleomar- 
garine is  a  product  made  in  imibition  of  butter,  which  it  resembles 
very  closely  in  color,  taste,  odor,  and  general  appearance.  It  is 
made  from  beef-fat,  which  is  hashed,  steamed,  aud  subjected  to 
pressure  at  a  carefully  regulated  temperature.  Under  this  treatment 
it  is  separated  into  two  fatty  products,  one  a  white  solid,  "stearin," 
the  other  a  faintly  yellow  oil,  "oleo-oil."  This  oil  is  then  mixed 
with  milk,  and  the  remaining  steps  in  the  manufacture  are  the  same 
as  ill  making  butter  from  cream.  "Butterine,"  "suine,"  etc.,  are 
products  made,  by  modifications  of  the  above  process,  from  beef  or 
mutton -tallow,  lard  and  cotton-seed  oil. 

Milk-plasma  —  the  liquid  portion  of  the  milk  remaining  after 
complete  removal  of  the  fat-globules,  contains  the  dissolved  con- 
stituents. These  consist  of  at  least  three  proteins:  Caseinogen,  the 
parent  substance  from  which  the  casein  is  derived,  lactalbumin,  and 
iactogiobulin;  two  carbohydrates,  milk  sugar  and  dextrine-like  sub- 
stance; mineral  salts;  and  small  quantities  of  lecithins,  nuclein, 
cholesterol,  urea,  creatin,  creatinin,  and  calcium  citrate. 

Casein  —  is  the  protein  produced  from  the  caseinogen  cf  milk 
by  the  coagulating  action  of  the  rennet  from  the  stomach  of  the 
calf.  Probably  the  caseinogens,  and  the  caseins  derived  therefrom, 
in  the  milk  of  different  kinds  of  animals  are  not  identical  with 
each  other.  That  from  human  milk  and  that  from  the  milk  of  the 
cow  differ  in  the  form  of  the  coagulum,  in  solubility  in  acids,  and 
in  the  nature  of  the  products  of  decomposition.  The  casein  of  cow's 
milk  is  a  nucleoalbumin,  and,  on  digestion  with  pepsin  and  hydro- 
chloric acid,  leaves  a  pseudonuclein,  which  is  not  the  case  with  the 
casein  from  human  milk.  It  contains  0.8%  of  sulfur,  and  0.85%  of 
phosphorus.  By  hydrolysis  of  cows'  milk  a  number  of  monamido  and 
diamido  acids  have  been  obtained:  tyrosin,  leucin,  glycocoU,  alanin, 
phenyl-alanin,  aspartic  acid,  glutamic  acid,  prolin,  arginin,  lysin,  and 
a  diamido  acid  having  the  empirical  formula  Ci2Ha6N206,  which  is  a 
diamidotrioxydodecan  acid.  Casein,  which  is  the  principal  protein  of 
cheese,  is,  when  dry,  a  white  powder,  very  sparingly  soluble  in  water 
and  in  solutions  of  neutral  salts,  except  that  it  is  somewhat  soluble 
in  1  per  cent  solutions  of  sodium  fluorid  or  of  potassium  or  ammonium 
oxalate.    It  behaves  as  an  acid  towards  alkaline  solutions,  in  which  it 


764 


MANUAL    OP    CHEMISTRY 


dissolves,  forming  solutions  which  may  be  neutral  or  even  acid,  if  the^ 
proportion  of  alkali  be  small.  It  expels  carbon  dioxid  from  calcium 
carbonate,  and  forms  a  soluble  compound  with  calcium  phosphate. 
Its  solutions  do  not  coagfulate  by  heat.  Addition  of  a  very  small 
quantity  of  dilute  bydroehlorie  or  acetic  acid  causes  precipitation  of 
casein  from  its  solutions,  less  readily  in  the  presence  of  neutral  salts; 
the  precipitate  dissolving  readily  in  au  excess  of  the  acid,  and  being 
again  produced  by  marked  excess  of  mineral  acids.  Neutral  solu- 
tions are  precipitated  by  salting  with  sodium  chlorid  or  mag-nesium 
sulfate,  and  by  solutions  of  alum,  or  of  zinc  or  copper  salts.  The 
most  notable  property  of  easeinogen  is  its  coagulation  (conversion 
into  casein  or  paracasein)  by  the  action  of  rennet,  in  the  presence  of 
calcium  salts* 

On  digestion  with  pepsin -hydrochloric  acid,  cow*s  casein  dis- 
solves! leaving  a  residue  of  a  nucleoalbumin,  whose  quantity  and 
whose  phosphorus -content  vary.  Indeed,  with  a  large  excess  of 
pepsin- hydrochloric  acid,  no  residue  remains.  By  trj-ptic  digestion 
the  phosphorus  is  split  off,  in  part  as  phosphoric  actd,  and  in  part 
in  organic  combination. 

Casein  may  be  obtained  from  milk  by  dilution  with  four  volumes 
of  water,  precipitation  by  addition  of  acetic  acid  to  1  p/m,  repeated 
resolution  in  dilute  alkali  and  repreeipitation  by  acetic  acid,  washing 
with  water,  drying;  and  washing  with  alcohol,  and  finally  with  ether. 

Lactalbumin  —  is  a  protein  containing  no  phosphorus,  and  1.73% 
of  sulfur.  It  has  the  properties  of  the  albumins,  and  resembles 
serum  albumin,  having  about  the  same  coagulation- tern pemture,  72° 
to  84°,  varying  with  the  proportion  of  salts  present,  but  having  a 
lower  specific  rotary  power:  [a]D  =  — 37°.  It  may  be  separated 
from  milk,  after  removal  of  laetoglobulin  and  casein  by  salting  with 
miiguesium  sulfate,  by  precipitatiou  with  acetic  a?id. 

Laetoglobulin  ^" closely  resembling,  if  not  identical  with  serum 
globulin,  is  a  protein  precipit^ble  from  milk,  after  removal  of  casein 
by  salting  with  sodium  chlorid,  by  saturation  with  magnesium 
sulfate. 

Lactose — see  p,  318. 

Mineral  salts  —  exist  in  eow^s  milk  in  the  proportion  of  about 
0.7%.  They  consist  of  the  chlorids  and  phosphates  of  sodium, 
potiissiuni,  calcium  and  magnesium,  and  traces  of  iron. 

Human  milk  —  differs  from  cow^s  milk  principally  in  the  pro* 
portion  of  the  several  eouBtituents,  and  in  the  nature  of  the  proteins. 
The  composition  of  cow's  milk  and  of  human  milk  is  given  by 
Kouig  as  follows; 


MILK 


765 


Water  .  . 
Total  BO  lids 
Fttt  .  ,  ,  - 
Milk  -  suf^^ar 
Casein 
Aibumin  » 
Proteins  . 
Ash     .    .    . 


Cow*fl  Milk 


M«jin 


87.41 

11.59 

3.66 

4-92 
3,01 
0.75 
3.76 
0.70 


Minimmm 


80.32 
8.50 
1.15 
3.20 
1.17 
0.21 
1.3B 
0.50 


Sflaxixniim 


91.50 
19,68 

7,09 
5.67 
7.40 
5.04 
12v44 
0.78 


HtrMAM  UitK 


Mean 


87.21 
12.71 
3.78 
6,04 
1.03 
1.26 
2.29 
0.31 


5tlD^mtuQ 


83.69 
9.10 
1,71 
4,11 
0.18 
0.39 
0,57 
0.14 


UaxLequid 


90.90 
16.31 
7.60 
7.80 
1.90 
2.35 
4.25 
f 


Therefore,  in  ha  man  milk  tlie  proportion  of  proteins  is  less,  and 
thaf  of  sugar  greater  than  in  eow^s  milk. 

The  casein  of  human  milk  is,  apparentl5%  not  a  nneleoalbiiinin, 
at  all  events  it  leaves  no  residue  of  psendonneleiu  on  digestion  with 
pepsin -hydroehloric  acid.  It  does,  however,  contain  pbospborns  in 
somewhat  less  proportion  than  cow's  casein,  0,68%.  It  is  coagulated 
incomplelely  by  rennet  in  fine,  separate  floeculi,  while  cow*s  casein  is 
tfoajj^uhitfrl  by  rennet  in  dense,  curdy  masses.  Human  casein  is  more 
ditMijultly  precipitated  by  acids  tban  cow's  casein,  and  is  more 
readily  soluble  in  slight  excess  of  the  acid.  These  differences  are  not 
dne  to  differences  in  the  nature  or  amount  of  the  salts  present,  but 
to  differences  in  the  proteins  themst^ves,  which  also  differ  in  their 
chemical  composition,  human  casein  containing  less  carbon,  nitrogen 
and  phosphorus  thati  cow's  casein,  and  more  hydrogen,  oxygen  and 
sulfur.  The  spontaneous  coagulation  of  human  milk  on  exposure  to 
air  at  the  ordinary  temperature  takes  place  luorc  slowly  than  that 
of  cow's  milk.  The  quantity  of  proteins  in  human  milk  is  notaldy 
greater  early  in  lactation  than  later,  being  as  high  as  3  p/ra  in  the 
earlier  stages.  The  proportion  of  milk-sugar,  on  the  contrary, 
increases  with  the  duration  of  lactation. 

Besides  caseinogeo,  lactalbumin  and  lactoglobulin,  human  milk 
contains  another  protein,  opalisin,  which  contains  a  large  propor- 
tion of  sulfur,  4.7%. 

Abnormal  Milk<~It  will  be  seen  by  the  table  given  above  that 
the  proportion  of  fat,  sugar  and  proteins  in  both  cow's  milk  and 
human  milk  vary  within  quite  wide  limits.  A  milk  containing  less 
than  the  minimum  of  these  constituents  there  given  is  certainly 
abnormal,  and  one  containing  no  more  than  the  mean  is  of  inferior 
quality.  The  New  York  state  dairy  law  declares  any  milk  found  on 
analysis  to  contain  ^Mess  than  12%  of  tnilk  solids,  which  shall  con- 
tain not  less  than  3%  of  fat"  to  be  adulterated.  These  limits  are 
fixed  upon  the  assumption ^  based  upon  a  gn^at  number  of  analyses. 


766  MANUAL   OF   CHSMIE^TBT 

that  a  milk  falling  below  the  requirements,  if  not  frandnlently 
adulterated,  is  the  product  of  cows  kept  under  improper  hygienic 
conditions,  or  diseased.  The  quality  of  milk,  whether  of  women  or 
of  cows,  is  affected  by  the  physical  condition  of  the  individual,  the 
nutrition,  and  the  composition  of  the  food,  the  duration  of  lactation, 
and  the  mental  emotions.  The  last-named  influence  the  quality  of 
the  milk  much  more  seriously  than  is  generally  appreciated.  The 
milk  of  cows  which  are  harsussed  or  excited  has  been  found  to  be 
much  more  liable  to  cause  alimentary  disturbances  in  infants  than 
that  obtained  from  animals  which  are  gently  treated  and  kept  free 
from  excitement.  It  is  also  well  known  that  the  milk  of  women 
during  violent  mental  excitement  may  become  absolutely  poisonous 
to  the  nursing  infant. 

Cow's  milk  has  been  frequently  the  medium  of  transmission  of 
disease.  Bacteria  are  found  in  the  freshly -drawn  milk  of  cows 
affected  by  disease,  and  it  has  been  stated  that  tuberculosis  may 
thus  be  transmitted  from  the  cow  to  the  human  subject.  Less  open 
to  question  is  the  transmission  of  diphtheria,  scarlet  fever,  and, 
particularly,  typhoid,  by  contamination  of  the  milk  by  exposure  to 
the  air,  or  by  admixture  of  contaminated  water,  particularly  as  mUk 
is  an  excellent  nutrient  material  for  bacteria.  The  physical  qualities 
of  milk  are  also  sometimes  modified  by  bacterial  action,  the  milk 
becoming  bitter  in  taste,  or  ropy  in  consistency,  or  red  or  blue  in 
color.' 

Medicinal  and  poisonous  substances  taken  by  the  mother  may 
pass  into  the  milk  in  quantity  sufficient  to  cause  serious  effects  upon 
the  nursiug  infant.  Thus  infants  are  frequently  narcotized  by  opiates 
taken  by  the  mother,  and  at  least  two  instances  of  fatal  poisoning 
by  this  means  have  been  reported. 

The  adulteration  of  milk  now  is  practically  limited  to  the  addition 
of  water,  or  the  removal  of  cream,  or  both. 

Analysis  ef  Milk. — The  constituents  of  milk  usually  determined 
in  milk  analysis  are:  total  solids  (milk -solids),  fat,  solids  not  fat, 
and  ash.  A  simple  method,  and  one  giving  sufficiently  accurate 
results,  is  that  of  Sharpies:  ten  cc.  of  the  milk  are  measured  out 
into  a  weighed,  flat  platinum  dish  (milk-dish),  and  weighed.  The 
difference  between  this  weight  and  that  of  the  dish  is  the  weight 
of  milk  used.  The  dish  is  then  placed  on  the  water-bath  until  the 
milk  is  evaporated  to  dryness,  heated  for  half  an  hour  in  an  air- 
oven  at  105°,  cooled  and  weighed.  This  weight,  minus  the  weight 
of  the  dish,  is  the  weight  of  milk-solids  in  the  weight  of  milk  used. 
The  dish  is  then  filled  with  petroleum -ether  (obtained  by  distilling 
gasolene  on  the  water-bath),  which  is  poured  off  from  the  solid 
residue,  which  usually  adheres  firmly  to  the  dish;  and  the  treatment 


MIIiK  767 

with  petroleum-ether  repeated  six  times.  The  residue  is  heated 
for  a  few  minutes  in  the  air-oven,  cooled,  and  weifi^hed.  This 
weight,  minus  that  of  the  empty  dish,  is  that  of  the  solids  not  fat; 
and,  subtracted  from  the  weight  of  milk-solids,  gives  the  weight 
of  fat  in  the  amount  of  milk  used.  The  residue  is  then  burnt  to 
a  white  ash,  cooled  and  weighed,  giving  the  amount  of  ash. 

The  extraction  of  fat  by  the  above  method  is  not  complete,  and 
therefore  the  determination  of  fat  is  affected  with  a  slight  minus 
error.  When  more  accurate  determination  of  fat  is  desired,  Adams' 
method  is  to  be  preferred:  strips  of  thin  blotting-paper  about  50 
cent,  long  and  6  cent,  wide,  which  have  been  freed  from  fat  by 
extraction  with  ether  and  with  alcohol,  dried  and  weighed,  along 
with  the  platinum  wire  below  referred  to,  are  used.  The  milk  sam- 
ple is  placed  in  a  small  wash -bottle,  which  is  then  weighed.  One 
of  the  paper  strips  is  suspended  in  a  horizontal  position,  and  from 
8  to  10  cc.  of  the  milk  are  distributed  over  it  from  the  wash -bottle, 
which  is  then  reweighed  to  determine  the  amount  of  the  sample 
used.  When  the  milk  upon  the  paper  strip  has  become  air-dried, 
the  strip  is  coiled  into  a  spiral,  about  which  the  platinum  wire  is 
fastened,  and  which  is  then  dried  in  an  air -oven  at  105°.  When 
dry,  the  spiral  is  cooled  and  weighed,  to  determine  the  total  solids, 
and  then  extracted  with  ether  in  a  Soxhlet  extractor.  The  fat  is 
determined  by  evaporation  of  the  ether  extract,  and  weighing  the 
residue. 

Of  the  more  rapid,  physical  methods  of  fat -determination  prob- 
ably the  most  satisfactory  is  that  of  Babeock:  The  milk  is  mixed 
with  an  equal  volume  of  sulfuric  acid,  transferred  to  a  small  bottle 
having  a  long,  thin,  graduated  neck,  constructed  for  the  purpose, 
and  centrifugated.  The  percentage  of  fat  is  read  off  on  the  graduation. 

For  the  determination  of  total  proteins  and  sugar  in  the  same  sam- 
ple, Ritthausen's  method  is  generally  used:  25  gm.  of  the  milk  are 
diluted  with  water  to  400  cc,  10  cc.  of  a  solution  of  CuSO*  contain- 
ing 6.5  gm.  to  the  litre,  and  a  solution  of  EHO  (14.2  gm.  to  the 
litre),  or  of  NaHO  (10.2  gm.  to  the  litre)  are  added  so  that  the 
reaction  remains  faintly  acid  or  neutral  (it  must  not  become  alkaline). 
When  the  precipitate  of  proteins  has  formed,  100  cc.  of  water  are 
added,  the  mixture  is  stirred  and  filtered  through  a  small  filter  of 
known  nitrogen -content.  The  filtrate  is  used  for  the  sugar  deter- 
mination: 100  cc.  are  added  to  50  cc.  of  boiling  Fehling's  solution, 
and  the  determination  is  concluded  as  usual.  The  protein  coagulum 
is  washed,  by  decantation  and  upon  the  filter,  with  water,  and  the 
proportion  of  nitrogen  is  determined  in  the  filter  and  precipitate  by 
Kjeldahrs  method.  The  nitrogen  found,  multiplied  by  6.37,  givea 
the  protein -content. 


APPENDIX. 


APPENDIX  A. 

ORTHOGRAPHY  AND  PRONUNCIATION  OP  CHEMICAL  TERMa 

In  1887  a  committee  was  appointed  by  the  American  Association 
for  the  Advancement  of  Science,  to  consider  the  question  of  securing^ 
uniformity  in  the  spellinfi^  and  pronunciation  of  chemical  terms.  The 
work  of  this  committee  extended  through  the  four  following  years. 
As  a  result  of  widespread  correspondence  and  detailed  discussion  at 
the  annual  meetings  of  the  Chemical  Section  of  the  American  Asso- 
ciation, the  following  rules  have  been  formulated  and  adopted  by 
the  Association. 

A  circular  embod3ring  the  substance  of  these  rules  has  been  issued 
by  the  Bureau  of  Education  at  Washington,  and  distributed  among 
chemists  and  teachers  of  chemistry,  with  a  recommendation  of  their 
general  adoption. 

GENERAL    PRINCIPLES    OP    PRONUNCIATION. 

1.  The  pronunciation  is  as  much  in  accord  with  the  analogy  of 
the  English  language  as  possible. 

2.  Derivatives  retain  as  far  as  possible  the  accent  and  pronun- 
ciation of  the  root  word. 

3.  Distinctly  chemical  compound  words  retain  the  accent  and 
pronunciation  of  each  portion. 

4.  Similarly  sounding  endings  for  dissimilar  compounds  are 
avoided,  hence  -In,  -Id,  -Ite,  -ate. 

ACCENT. 

In  polysyllabic  chemical  words  the  accent  is  generally  on  the 
antepenult;  in  words  where  the  vowel  of  the  penult  is  followed  by 
two  consonants,  and  in  all  words  ending  in  -ic,  the  accent  is  on  the 
penult. 

PREFIXES. 

All  prefixes  in  strictly  chemical  words  are  regarded  as  parts  of 
compound  words,  and  retain  their  own  pronunciation  unchanged  (aa 
ft^ceto-,  ft^mldo-,  ft'zo-,  hy^dro-,  iW,  ni'tro-,  nltro^so-). 

^(771) 


772 


MANUAL   OF    CHElilSTBT 


ELEMENTS. 


In  words  ending  in  -ium,  the  vowel  of  the  antepenult  is  short  if  i 
(as  irl'dium),  or  y  (as  dldj^^mium),  or  if  before  two  consonants  (as 
cftOcium),  but  long  otherwise  (as  titta^nium,  sSle^nium,  chrd'mium). 


aia'minium 

e'rbiam 

me'rcury 

'sO'dium 

a'ntimony 

flii'orin 

m()lj^'bdenam 

strd'ntiam 

a'reSnio 

gft'llium 

nl'ckel 

(sbiam) 

bft'rium 

germft'niam 

nl'trogen 

stt'lfur 

bi'smuth  (biz) 

gitl'oinam 

d'smium 

t&'ntalum 

bO'ron 

gold 

5'xygen 

telliL'riam 

br()'mln 

hy'drogen 

pallft'dium 

te'rbinm 

o&'dmiam 

I'ndium 

phds'phoras 

th&'lliam 

oft'loiom 

I'odin 

plft'tinum 

thO'rium 

ca'rbon 

Irl'dinm 

potft'sBium 

tin 

06'riam 

iron 

rh()'diam 

tltft'ninm 

oS'sium 

Ift'nthanom 

rabfdiam 

ta'ngsten 

ohlO'rln 

lead 

rathe'nium 

firft'niiim 

chrO'mium 

Ifthiom 

samft'riam 

▼ftnfi'dinm 

cO'balt 

magne'siam 

so&'ndium 

ytte'rbiam 

colft'mbium 

(zhimn) 

8«l6'niam 

fttriom 

co'pper 

ma'nganese 

El'licon 

zinc 

dldjKmium 

(eze) 

silver 

zireO'nium 

Also:  ftmrno^nium,  phospho^nium,  h&^logen,  ey&^nogen,  &mf- 
dogen. 

Note  in  the  above  list  the  spelling  of  the  halogens,  cesium  and 
sulfur;  f  is  used  in  the  place  of  ph  in  all  derivatives  of  sulfur  (as 
sulfuric,  sulfite,  sulfo-,  etc.). 


TERMINATIONS    IN   -IC. 

The  vowel  of  the  penult  in  polysyllables  is  short  (as  cya'nie, 
fuma^ric,  arsfi^nic,  sill'cic,  Wdic,  butj^^ric),  except  (1)  u  when  not 
used  before  two  consonants  (as  mercu^ric,  prii^'ssic),  and  (2)  when 
the  penult  ends  in  a. vowel  (as  benzo^ic,  ole^ic);  in  dissyllables  it  is 
long  except  before  two  consonants  (as  bo^ric,  cl'tric).  Exception: 
ace^'tic  or  acS^tic. 

The  termination  -ic,  is  used  for  metals  only  where  necessary  to 
contrast  with  -ous  (thus  avoid  aluminic,  ammonic,  etc.). 


Fate,  f&t,  far,  m$te,  mSt,  pine,  pin,  marine,  n5te,  n6t,  mdve,  tube,  tflb,  riile, 
my,  .^  =  I. 

'  Primary  accent;  "secondary  accent.  N.  B.— The  accent  follows  the  vowel 
of  the  syllable  upon  which  the  stress  falls,  but  does  not  indicate  the  division  ot 
the  word  into  syllables. 


OBTHOGBAPHT   AND   PRONUNCIATION  773 


TERMINATIONS    IN    OUS. 

The  accent  follows  the  general  rule  (as  pl&^tinons,  stl^lfaroas, 
ph5'sphorons,  coba^ltous).     Exception:    aee^tous. 

TERMINATIONS    IN    -ate    AND   -ite. 

The  accent  follows  the  general  rule  (as  ft^cetate,  v&^nadate) :  in 
the  following  words  the  accent  is  thrown  back:  ft'bietate,  ftlcoholate, 
&^cetonate,  ft^ntimonite. 

TERMINATIONS    IN   -id    (FORMERLY    -ide). 

The  final  e  is  dropped  in  every  case  and  the  syllable  pronounced 
Id  (as  chlo'rid,  i'odid,  hy'drld,  6'xld,  hydr^'xld,  sii'lfld,  a'mld, 
a'nilld.  mure'xid). 

TERMINATIONS  IN  -anc,  -CHC,  -inc,  AND  -onc. 

The  vowel  of  these  syllables  is  invariably  long  (as  mfi^thane, 
5'thane,  na^phthalene,  a'nthracene,  pro^pine,  qui'none,  ft^cetone, 
ke'tone). 

A  few  dissyllables  have  no  distinct  accent  (as  benzene,  xylene, 
cetene). 

The  termination  -ine  is  used  only  in  the  case  of  doubly  unsatu- 
rated hydrocarbons,  according  to  Hofmann's  grouping  (as  proplne). 

TERMINATIONS    IN    -in. 

In  names  of  chemical  elements  and  compounds  of  this  class,  which 
includes  all  those  formerly  ending  in  -ine  (except  doubly  unsaturated 
liydrocarlmiis),  the  final  e  is  dropped,  and  the  syllable  pronounced 
-in  (as  ohlo^'rln,  bro^mln,  etc.,  ft^mln,  ft^'nilln,  mo^rpHn,  qnl'nin 
(kwl^nln),  vanl'llln,  alloxft^ntln,  absi^nthln,  emti^lsTn,  c&^'ffeln, 
co'caln). 

TERMINATIONS    IN   -ol. 

This  termination,  in  the  case  of  specific  chemical  compounds,  is 
used  exclusively  for  alcohols  (and  phenols,  W.),  and  when  so  used  is 

Fate,  f&t,  far,  mSte,  m6t,  pine,  pin,  marine,  nOte,  n6t,  mdve,  tflbe,  ttib,  riile, 

my,  y  =  i. 

'  Primary  accent;  "  secondary  accent.  N.  B.— The  accent  fonows  the  vowel 
of  the  syllable  npon  which  the  stress  falls,  but  does  not  indicate  the  division  of 
the  word  into  syllables. 


774  MANUAL   OP    CHEMISTRY 

never  followed  by  a  final  e.  The  last  syllable  is  pFononnced  -51 
(as  gly^'col,  phe'nol,  cre'sol,  thy'mol  (ti),  gly^'cerol,  qui'nol.) 
Exceptions:     ft''lcoh51,  a^'rgdl. 


TERMINATIONS    IN   -olc. 

This  termination  is  always  pronoaneed  -ole,  and  its  use  is  limited 
to  compounds  which  are  not  alcohols  (or  phenols,  W.)  (as  I^nddle). 


TERMINATIONS    IN    -yl. 

No  final  e  is  used;  the  syllable  is  pronounced  j^l  (as  &^cetj^l,  &^mj^l, 
ee'rotj^l,  ce'tj^l,  fi'thyi). 


TERMINATIONS    IN   -yde. 

The  y  is  long  (as  ft^ldehyde). 

TERMINATIONS  IN  -meter. 

The  accent  follows  the  general  rule  (as  hydrft'meter,  bar5^meter, 
lactft^'meter) .  Exception:  words  of  this  class  used  in  the  metric 
system  are  regarded  as  compound  words,  and  each  portion  retains 
its  own  accent  (as  cfi'ntirae'^ter,  mi^'Uime^^ter,  kl^lome^'ter) . 


MISCELLANEOUS  WORDS  WHICH  DO  NOT  PALL  UNDER  THE 
PRECEDING  RULES. 

Note  the  spelling:  albumen,  albuminous,  albuminiferous,  asbestos, 
gramme,  radical. 

Note  the  pronunciation:  a^'lkaline,  a^'lloy  (n.  and  v.),  a^'llotropy, 
a'llotropism,  i'somerism,  p5''lymerism,  appara^tus  (sing,  and  plu.), 
aqua  regia,  bary'ta,  centigrade,  co^'ncentrated,  crystallln  or  crys- 
talline, electrd'lysis,  liter,  mft'lecule,  m516^cular,  no'mencla"ture, 
ole^fiant,  va'lence,  u^niva^^lent,  Wva^'lent,  tri^'va^'lent,  qua^driva^'lent. 
tl'trate. 


Fate,  f&t,  far,  mSte,  mfit,  pine,  pin,  marine,  nOte,  n6t,  m6ve,  tube,  ttlb,  riile, 

my,  y=t. 

'  Primary  accent;  "  secondary  accent.  N.  B.— The  accent  follows  the  vowel 
of  the  syllable  upon  which  the  stress  falls,  but  does  not  indicate  the  division  oi 
the  word  into  syllables. 


OBTHOGRAPHY    AND   PRONUNCIATION 


775 


A    UST    OF   WORDS   WHOSE    USE    SHOULD    BE    AVOIDED   IN    FAVOR    OF 
THE    AGGOMPANTING    STNONTMS. 

For —  Use  — 

sodic,   calcic,   zinoio,   nickelio,   etc.,  sodium,  calcium,   ziuc,   nickel,   etc., 

chlorid,  etc.  chlorid,  etc.  (vid.  tenninations 

in  -!c  supra). 

arsenetted  hydrogen arsin 

untimonetted  hydrogen stibln   * 

phosphoretted  hydrogen .  phosphin 

sulfuretted  hydrogen,  etc hydrogen  sulfid,  etc. 


For^  Use— 

beryllium gluoinnm 

niobium  .....  columbium 

glycerin glycerol 

hydroquinone  (and 

hydrochinon)  .   .  quinol 
pyrocatechin  .   .   .  catechol 
resorcin,  etc.  .   .   .  resorcinol,  etc. 

mannite mannitol 

dulcite,  etc.   .   .   .  dulcitol,  etc. 
benzol  ......  benzene 

toluol,  etc toluene,  etc. 

theln oaifein 


For —  Use— 

furfurol fnrfuraldehyde 

fucusol fucusaldehyde 

anisol methyl  phenate 

phenetol ethyl  phenate 

anethol methyl  allylphenol 

alkylogens  ....  alkyl  haloids 
titer  (n.)     ....  strength  or  stand- 
ard 
titer  (▼.)     ....  titrate 
monovalent    .   .   .  uniyalent 
divalent,  etc.     .   .  biyalent,  etc. 
quantiyalence    .   .  valence 


APPENDIX  B.— TABLES- 


TABLB  L— 80L.UBILITIB& 
FBBSBNIUS. 

W  or  w=8olable  in  HsO.  A  or  a^'insolnble  in  HgO;  actable 
in  HCl,  HNOs,  or  aqna  regia.  I  or  1  =  insolable  in  HsO  and  adida. 
W-A  =  sparinnrlj  soluble  in  HgO,  bat  soluble  in  acids.  W-I  = 
sparingly  soluble  in  HsO  and  aeids.  A-I  =  insoluble  in  EbOt  siMur- 
iufi^  soluble  in  acids.    Capitals  indicate  common  substances. 


1 

a 

B 

B 

1 

t 

< 

1 

w 

1 

1 
1 

1 

W 

1 

1 
& 

1 

1 

Aeetftte  , 

^   -     W 

W 

w 

w 

w 

w 

W 

w 

W 

Anenate 

A 

w 

B 

a 

a 

a 

a 

a 

a 

a 

a 

Arsetitte . 

w 

a 

a 

•   « 

«   » 

a 

,    - 

a 

A 

a 

BeBso&t« 

►    -       W 

w 

w 

.   , 

w 

w 

*    . 

a 

w 

EoFfttO      . 

.    .        A 

w 

a 

a 

w-^a 

a 

a 

a 

a 

a 

Bromid   , 

.    .        W 

W 

w-a 

w 

w-a 

w 

w 

w-i 

w 

w 

w 

C&rbon&te 

^   ^      i^ 

W 

A 

A 

a 

A 

a 

A 

A 

A 

Chlorftte  . 

.   .      w 

w 

W 

w 

w 

w 

w 

W 

w  ■ 

w 

Chlorid    * 

.   .      w 

W^" 

W-A* 

w 

W-A'^ 

W 

W 

W^^I 

W 

W 

W 

W 

Chrom&to 

w 

& 

a 

a 

a 

w-a 

a 

a 

w 

w 

Citrate.  . 

w 

w 

a 

a 

w-a 

w 

w 

w 

vr 

W 

Cyanid    ♦ 

w 

»   * 

w-a 

a 

w 

a 

a-i 

a 

a-i 

-  « 

Ferriojanic 

I ;  ; ; 

w 

,   . 

w 

•   • 

i 

.    . 

I 

w 

FeTrtMsyani* 

1 . 

w 

W-ft 

»   , 

w 

J 

i 

I 

r 

Flaorid    , 

.   .      w 

W 

w 

a-i 

w 

w-a 

A 

w 

w-a 

a 

w-a 

w 

Formate  . 

w 

w 

w 

w 

w 

w 

w 

W 

w 

w 

w 

Hydrate  . 

A 

W 

a' 

W 

a 

a 

W"A 

A 

A 

n 

a 

A 

lodid   .    . 

w 

W 

w-a 

w 

a 

W 

w 

w 

w 

w 

W 

w 

Malate.  . 

w 

w 

w-a 

.    . 

w-a 

*    » 

.    . 

w 

Nitrate    . 

w 

'  W 

W 

W" 

w 

w 

W 

W 

W 

W 

W 

Oxalate   , 

& 

w 

a 

a 

a 

a 

A 

w-a 

A 

a 

a 

a 

Oxid  .  .    . 

A-I 

a' 

W 

a 

a 

W-A 

A-I 

A 

A 

a 

A 

Pboiphate 

a 

vp 

w~a 

w-a 

a 

a 

W-A 

a 

a 

a 

n 

a 

Silicate  . 

.    A-T 

a 

,   * 

a 

a 

a 

a 

a 

a 

a 

Suocinate  . 

w  11 

w 

w^a 

,   ^ 

w 

w-a 

.   ^ 

w-a 

w-n 

w 

, 

Sujfate    . 

W^ 

w 

a 

A 

w 

W 

W-1 

W'A^' 

W\ 

W 

W 

W 

Snlfid  .    , 

a 

w 

A* 

W 

a 

A 

W-A 

a-i 

a 

A 

A 

A 

Tat-lratd.   . 

w 

w» 

E» 

& 

a 

WK 

a        w    1 

w 

w 

w-a 

W** 

MAl2)(NH4)2(S04)4=W;    (Al2)K2(S04)4=W.     2As(NH4)Cl4=W; 

Pt(NH4)Cl5=W-I.  3HNa(NH4)P04=W;  Mg(NH4)P04=A.  ♦Pe- 
(NH4)2(S04)2=W;  Cu(NH4)2(S04)2=W.  «C4H40^(NH4)=W.  "Sb- 
OCl=A.  'Sb203=8oluble  in  HCl,  not  in  HNO3.  «SbjS8=sol.  in  bot 
HCl,  slightly  in  HNO3.  •C4H40(iK(SbO)=W.  "BiOCl=A.  "(BiO) 
N03=A.  ^(Cr2)K2(S04)4=W.  "CoS=ea8Uy  sol.  in  HNO,,  very 
slowly  in  HCl.    "(C4H40«)4(Pe2)K2=W. 

(776) 


SOLUBILITIES 


777 


TABLE   L—  SOLUBI LITIES.—  Continued. 
FRESENIUS. 

W  or  w  =  fioliiLjle  ia  H-jO*  A  or  a  ^insoluble  in  H2O;  soluble 
in  HCl,  HNO^j,  or  aqiiti  m^in.  I  or  i  ^=  iuisolubJe  in  H2O  aod  acids. 
W-A  =^  sparingly  soluble  in  Hi;0,  but  soluble  iu  adds.  W-I  =  spar- 
ingly soluble  iu  HiO  and  aeids,  A-I  ^=  insoluble  in  HgO^  spariogly 
soluble  in  at^ids.     Capitals  indicate  eoratnon  substances. 


i 

1 

si 

i 

E 
t 

i 
w 

•3 

i 

£ 

1 

1 

i 
1 

0 

0- 

s 

1 

B 
^       1 

\ 

Aoetate    .   . 

W 

W 

W 

w 

w 

w 

W 

w 

w 

w 

w 

Arsenate 

a 

a 

a 

a 

a 

a    1 

w 

a 

w 

a 

a 

a 

» 

Arseult'e  .   . 

a 

a 

a 

a 

a 

a 

w 

a 

w 

a 

a 

.   . 

, 

Benxoata     . 

a 

w 

w 

a 

w-a 

w 

w-a 

w 

.   . 

Borate      .   . 

a 

w-a 

a 

a 

W 

a 

W 

a 

a 

a 

Broraid  .  .    . 

w-i 

w 

w 

a  i 

w 

w 

w 

a 

w 

w 

w 

Carbonate   . 

A 

A 

A 

a 

a 

A 

w 

& 

w 

A 

.   . 

A 

Chlorate  .    . 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

Chloric!  .  .    . 

W-I 

W 

W 

A-I 

W'« 

W 

w 

I 

w 

W 

W 

W 

W 

Chromate*  . 

A  I 

w 

w 

a 

W'll 

a 

w 

a 

w 

W-B 

a 

w 

Citrate  .  .    . 

a 

w 

a 

a 

W    ft 

w 

w 

a 

W 

a 

w-a 

Cyan  id  - 

a 

w 

a 

W 

a-i 

W 

w 

w 

a 

Ferricyanld 

W-B 

w 

i 

i 

w 

w 

a 

Ferroeyanid 

a 

w 

a 

i 

w 

w 

w 

a  i 

Fluorid  .  . 

a 

a-i 

a 

w-a 

w-a 

w 

w 

w 

a-i  . 

w 

w 

w-a 

Formate  .    . 

w-a 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

Hydrate  ,    . 

a 

A 

a 

,    ^ 

a 

W 

W 

w 

a 

a 

a 

lodid     .    .    . 

W  A 

w 

w 

A 

a' 

w 

W 

i 

w 

w 

W 

w 

w 

Malate  ■ 

w^a 

w 

w 

a 

w  a 

w 

w-a 

w 

w 

TV 

w 

w 

Nitrate  ,  .    . 

W 

w 

w 

W 

W 

W 

W 

W 

W 

W 

w 

Oxalate.  .    . 

ft 

a 

w-ri 

a 

a 

a 

w  1 

a 

W 

ft 

ft 

w 

a 

Ox  id     .    . 

A 

A 

A'=^ 

'    A 

A 

A 

w 

a 

W 

W 

a 

AT 

A 

Phosphate  . 

a 

e 

a 

a 

a 

a 

w 

a 

W 

a 

a 

a 

a 

Silicate    .    . 

a 

a 

a 

a 

W 

W 

a 

a 

SiM'cinate 

a 

w 

W 

a 

w  a 

w 

w 

a 

w 

w-:i 

a 

r-a 

Sulfate  .  .    , 

A-l 

W 

W 

W-fti 

w- 

W 

W'^ 

W-A 

W 

1 

w 

W 

8ujad    .    .    , 

A 

a 

a 

ft 

A"^ 

A'« 

W 

^71 

W 

w    1 

a" 

A- 

A'^ 

Tartrate  . 

a 

w-a 

w-tt 

W-ft 

a 

a 

W 

a 

w 

a 

n 

a 

^''MnO^^^soL  in  HCl;  insoL  in  HNO3*  ^^'Merenrammoiiiiim 
chlorid^A,  ^^  Basic  sulfate  =  A.  ^^HgS  ==insol,  in  IICl  and  in 
HNO3.  soh  ia  aqua  regia.  ^^  See  13.  ^'PtKCls-^W-A.  ^Hlnly 
soluble  in  IINO3.  -  Su  sulfids  =  soL  in  hot  HC!;  oxidized,  not 
dissolved,  by  HNOy.  Hublinied  SuCU  only  soL  in  aq*  regia*  -*  Easily 
sol.  in  HNO3.  diflRcuUly  in  HCL 

Au2S=^insoL  in  HCl  and  in  HNO:i,  sol.  in  aq.  regia.  AnBrg, 
AuCU  and  Au(CN)3  =  w;  Aula  =  a  PtS2=insol.  in  HCl  slightly 
BoL  in  hot  HNOj*;  sol.  in  aq.  regia.  PtBr*,  PtCU,  Pt(CN)i, 
Pt(N0a)4,  Pt(C204)2,  Pt(S04)2=  w;    Pt02=a;   PtU=i. 


m 


MANUAL   OF   CHElflSTBT 


TABLB  n.r-WBIQHT8  AND   MBASURBS. 


MSASUBBS    (HP    LKNGTH. 


1  millimeter  = 

0.001  meter  »     0.0894  ineli. 

1  centimeter  » 

0.01       "      «     0.8987    '' 

1  deeimeter   » ( 

D.l         ''     «     8.9871  ineliee. 

1  ifSTBR 

a   89.8708 

i« 

Ideevneter  » 

10  meters  »   82.8089  feet. 

100      ''       » 888.089      *' 

1  kilometer   » 1000      '<       «     0.6214  mUe. 

T^yfc 

mniBMCMnk 

ImOtm.            OsBftimeten.        i       UiebM. 

OmtliMton^ 

11          ss 

0.8819 

»         6.08 

9 

a        82.86 

1  r       " 

0.7687 

=         7.62 

10 

a        85.40 

JC           ss 

1.1^5 

»        10.16 

11 

a        27.94 

as 

8.175 

a       12.70 

12 

a        80.48 

^ 

6.86 

a        16.24 

18 

a        45.72 

ss 

12.7 

a        17.78 

24 

a       60.96 

85.4 

»       20.82 

86 

a        91.44 

MSARUBB8    OF    0APA0IT7. 

1  milliliter  »       I  e.o. 

»  0.001  liter  a     0.0021  U.  8. 

pint. 

lflentiUter«     10    '* 

=  0.01      "    -     0.0211 

*^€t 

IdeeiUter  »    100    <' 

»0.1        *'    »     0.2118 

<• 

1  UTBR     «  1000    '' 

a     1.0667 

qamrt. 

1  deMliter 

a     10  Uten  a     2.6418 

gmlle. 

1  heetoliter 

a    100     '<     a    26.418 

^  <« 

1  kiloUter 

a  1000     "     a  264.18 

II 

m,         e.e. 

m.         e^. 

M.            c.e. 

Vl3          eA 
0  a  147.81 

1«>0.06 

26  a  1.60 

51  a     8.14 

2  »  0.12 

27  =  1.66 

52  a     8.20 

6  a  177.89 

8  »  0.19 

28  «  1.78 

58  a     8.26 

7  a  206.96 

4  =  0.25 

29=1.79 

54  =     8.32 

8  a  236.53 

5  =  0.31 

30  =  1.85 

55  =      3.39 

9  =  266.10 

6  =  0.37 

31  =  1.91 

56  =      3.46 

IC  =  295.68 

7  =  0.43 

32  =  1.98 

57  =      3.52 

11  =  325.25 

8  =  0.49 

33  =  2.04 

58  =      8.58 

12  =  354.82 

9  =  0.55 

34  =  2.10 

59  =      3.64 

13  =  384.40 

10  =  0.62 

35  =  2.16 

60  =      3.70 

14  =  413.97 

11  =  0.68 

36  =  2.22 

Fl3. 
1  =      3.70 

15  =  443.54 

12  =  0.74 

37  =  2.28 

16  =  473.11 

13  =  0.80 

38  =  2.34 

2  =      7.39 
3=    11.09 
4=    14.79 
5=    18.48 
6=    22.18 
7=    25.88 
8=    29.57 

0.          LitrM. 

14  =  0.86 

39  =  2.40 

1  =      0.47 

15  =  0.9  J 

40  =  2.46 

2  =      0.95 

16  =  0.99 

41  =  2.52 

3  =      1.42 

17=  1.05 

42  =  2.58 

4=      1.89 

18=  1.11 

43  =  2.66 

6  =      2.36 

19=  1.17 

44  =  2.72 

6=      2.84 

20=1.23 

45  =  2.77 

7  =      3.31 

21  =  1.29 

46  =  2.84 

Pl3. 

8  =      3.79 

22=  1.36 

47  =  2.90 

1=    29.57 

9  =      4.26 

23  =  1.42 

48  =  2.96 

2=    59.14 

10  =      4.73 

24=  1.48 

49  =  3.02 

8=    88.67 

11  a      5.20 

25  =  1.54 

50  = 

=  3.08 

4  =  118.24 

12  =      5.67 

WEIGHTS   AND    liEASURES 


779 


WEIGHTS. 


1  milligram  =  0.001  gram  =  0.015  grain  Troy. 

1  centigram  =  0.01       **  =  0.154     ** 

1  deoign^m    =0.1         *'  =  1.543  grains 

1  ORAM  =  15.432      ** 

1  decagram   =        10  grams  =  154.324      *' 

1  hectogram  =      100      **  =  0.268  1b. 

1  kilogram     =    1000      *'  =  2.679  lbs. 


Onint.  Oimms. 
A  =  0.001 
A  =  0.002 
A  =  0.004 

i  =  0.008 
*i  =  0.016 

i  =  0.032 

1  =  0.066 

2  =  0.130 

3  =  O.IM 

4  =  0.259 

5  =  0.324 

6  =  0.389 

7  =  0.454 

8  =  0.518 

9  =  0.583 

10  =  0.648 

11  =  0.713 

12  =  0.778 

13  =  0.842 

14  =  0.907 

15  =  0.972 
16=  1.037 
17  =  1.102 
18=  1.166 
19=1.231 
20=  1.296 


Orains.  Grams. 
21  =  1.361 
22=  1.426 
23=  1.458 

24  =  1.555 

25  =  1.620 

26  =  1.685 

27  =  1.749 

28  =  1.814 

29  =  1.869 

30  =  1.944 

31  =  2.009 

32  =  2.074 

33  =  2.139 

34  =  2.204 

35  =  2.268 

36  =  2.332 

37  =  2.397 

38  =  2.462 

39  =  2.527 

40  =  2.592 

41  =  2.657 

42  =  2.722 

43  =  2.787 

44  =  2.852 
46  =  2.916 
46  =  2.980 


Grains 

.  Grams 

47  = 

3.046 

48  = 

3.110 

49  = 

3.175 

60  = 

3.240 

51  = 

3.305 

52  = 

3.370 

63  = 

3.434 

54  = 

3.499 

55  = 

3.564 

56  = 

3.629 

57  = 

3.694 

68  = 

3.758 

69  = 

3.823 

60  = 

3.888 

3 

1  = 

3.888 

2  = 

7.776 

3  = 

11.664 

4  = 

15.552 

•5  = 

19.440 

6  = 

23.328 

7  = 

27.216 

8  = 

31.103 

3 

1  = 

2  = 

3  = 

4  = 

5  = 

6  = 

7  = 

8  = 

9  = 

10  = 

11  = 

12  = 
Lbs. 

1  = 

2  = 
3: 
4  = 
6: 

6: 
7: 
8: 
9: 
10: 


Grams. 

31.103 

62.207 

93.310 

124.414 

155.517 

186  621 

217.724 

248.823 

279.931 

311.0.3.'S 

342.138 

373.  JSO 

Kilos. 

0.373 

0.747 

1.1'JO 

1.493 

1.866 

:      2.1i40 

2.613 

2.986 

3.359 

3.733 


1  pound  Avdp. 
1  kilo 


453.5925  gm. 
2.2046  lbs.  Aydp. 


780 


MANUAL  OP   CHEMI8TBY 


TABLB  m. 
WEIGHT    OF    ONE    CUBIC    CENTDCETEB   OP   NITBOOEN. 


r  io» 

728 

730 

732 

734 

736 

738 

740 

7« 

1.1466 

1.1498 

1.1629 

1.1661 

1.1693 

1.1626 

1.1667 

1.1689 

• 

11- 

1.1416 

1.1447 

1.1479 

1.1611 

1.1642 

1.1674 

1.1606 

1.1638 

t 

12» 

1.1364 

1.1396 

1.1428 

1.1469 

1.1491 

1.1628 

1.1664 

1.1686 

13» 

1.1314 

1.1346 

1.1377 

1.1409 

1.1440 

1.1472 

1.1603 

1.1536 

^ 

w 

1.1263 

1.1294 

1.1326 

1.1367 

1.1389 

1.1420 

1.1462 

1.1483 

1 

15* 

1.1211 

1.1243 

1.1274 

1.1306 

1.1337 

1.1368 

1.1399 

1.1431 

16* 

1.1160 

1.1191 

1.1222 

1.1263 

1.1286 

1.1316 

1.1347 

1.1378 

3 

17- 

1.1107 

1.1188 

1.1170 

1.1201 

1.1232 

1.1263 

1.1294 

1.1325 

s 

18* 

l.KMH 

1.1086 

1.1117 

1.1148 

1.1179 

1.1209 

1.1241 

1.1272 

s 

19«> 

1.1001 

1.1032 

1.1063 

1.1094 

1.1126 

1.1166 

1.1187 

M218 

I 

20* 

1.0948 

1.0979 

1.1009 

1.1040 

1.1071 

1.1102 

1.1133 

1.1164 

21- 

1.0894 

1.0924 
l.te70 

1.0966 

1.0986 

1.1017 

1.1047 

1.1078 

1.1109 

22** 

1.0839 

1.0900 

1.0931 

1.0961 

1.0992 

1.1023 

1.1068 

23* 

1.0784 

1.0814 

1.0846 

1.0876 

1.0906 

1.0936 

1.0967 

1.0997 

H 

j^O 

1.0728 

1.0768 

1.0789 

1.0819 

1.0849 

1.0880 

1.0910 

1.0940 

L  25*» 

1.0671 

1.0701 

1.0732 

1.0762 

1.0792 

1.0823 

1.0863 

1.0888 

728 

730 

732 

734 

736 

738 

740 

7« 

r  io«» 

744 

746 

748 

• 

750 

752 

754 

750 

758 

1.1721 

1.1768 

1.1786 

1.1817 

1.1848 

1.1880 

1.1912 

1.1944 

o 

ii« 

1.1670 

1.1701 

1.1733 

1.1766 

1.1717 

1.1829 

1.1860 

1.1892 

1 

12<' 

1.1618 

1.1649 

1.1681 

1.1713 

1.1744 

1.1776 

1.1808 

1.1839 

13*> 

1.1566 

1.1598 

1.1630 

1.1661 

1.1693 

1.1724 

1.1756 

1.1787 

14^ 

1.1515 

1.1546 

1.1577 

1.1609 

1.1640 

1.1672 

1.1703 

1.1735 

15** 

1.1462 

1.1493 

1.1525 

1.1556 

1.1587 

1.1619 

1.1650 

1.1681 

O 

16*> 

1.1409 

1.1441 

1.1472 

1.1503 

1.1534 

1.1566 

1.1597 

1.1628 

d 

17** 

1.1356 

1.1397 

1.1419 

1.1450 

1.1481 

1.1512 

1.1543 

1.1574 

BO 

18*> 

1.1303 

1.1334 

1.1365 

1.1396 

1.1427 

1.1458 

1.1489 

1.1520 

t 

19° 

1.1248 

1.1279 

1.1310 

1.1341 

1.1372 

1.1403 

1.1434 

1.1465 

i 
1 

20*> 

1.1194 

1.1225 

1.1256 

1.1287 

1.1318 

1.1348 

1.1379 

1.1410 

21*^ 

1.1139 

1.1170 

1.1201 

1.1231 

1.1262 

1.1293 

1.1324 

1.1354 

22° 

1.1084 

1.1115 

1.1145 

1.1176 

1.1206 

1.1237 

1.1268 

1.1298 

23° 

1.1028 

1.1058 

1.1089 

1.1119 

1.1150 

1.1180 

1.1211 

1.1241 

H 

24° 

1.0971 

1.1001 

1.1032 

1.1062 

1.1092 

1.1123 

1.1153 

1.1184 

L  25° 

1.0913 

1.0944 

1.0974 

1.1004 

1.1035 

1.1065 

1.1095 

1.1126 

744 

746 

748 

750 

752 

754 

756 

758 

Barometric  pressure  in  millimeten. 


TABLE    m 


781 


TABLE  IIL— Continued. 
WEIGHT    OF    ONE    CUBIC    CENTIMETER    OF    NITROGEN. 


r  10*^ 

760 

762 

764 

766 

768 

770 

772 

774 

1.1976 

1.2008 

1.2040 

1.2072 

1.2104 

1.2136 

1.2167 

1.2199 

9 

11° 

1.1924 

1.1956 

1.1988 

1.2019 

1.2051 

1.2083 

1.2116 

1.2147 

I 

12° 

1.1871 

1.1903 

1.1934 

1.1966 

1.1998 

1.2029 

1.2061 

1.2093 

13^ 

1.1819 

1.1851 

1.1882 

1.1914 

1.1945 

1.1977 

1.2008 

1.2040 

♦J 

14° 

1.1766 

1.1798 

1.1829 

1.1861 

1.1892 

1.1923 

1.1955 

1.1986 

^ 

15° 

1.1713 

1.1744 

1.1776 

1.1807 

1.1838 

1.1869 

1.1901 

1.1932 

Q 

1G° 

1.1659 

1.1691 

1.1722 

1.1753 

1.1784 

1.181d 

1.1847 

1.1878 

d 

17° 

1.1605 

1.1636 

1.1667 

1.1699 

1.1730 

1.1761 

1.1792 

1.1823 

00 

18° 

1.1551 

1.1582 

1.1613 

1.1644 

1.1675 

1.1706 

1.1737 

1.1768 

t 

19° 

1.1496 

1.1527 

1.1658 

1.1589 

1.1620 

1.1650 

1.1681 

1.1712 

p 

i 
1 

20° 

1.1441 

1.1472 

1.1502 

1.1533 

1.1564 

1.1595 

1.1626 

1.1657 

21° 

1.1385 

1.1416 

1.1446 

1.1477 

1.150ri 

1.1539 

1.1569 

1.1600 

22° 

1.1329 

1.1359 

1.1390 

1.1421 

1.1461 

1.1482 

1.1512 

1.1643 

§ 

23° 

1.1272 

1.1302 

1.1333 

1.1363 

1.1394 

1.1424 

1.1455 

1.1485 

eS 

24° 

1.1214 

1.1244 

1.1275 

1.1305 

l.iri^O 

1.1  :m6 

1.1396 

1.1427 

L  26° 

1.1156 

1.1186 

1.1216 

1.1247 

1.1277 

1.1307 

1.1338 

1.1368 

760 

762 

764 

766 

768 

770 

772 

774 

r  10° 

776 

778 

780 

782 

7%4 

786 

7^-8 

790 

1.2231 

1.2263 

1.2295 

1.2327 

1.2359 

1.2391 

i.24::3 

1.2464 

6 

11° 

1.2178 

1.2210 

1.2242 

1.2274 

1.2306 

1.2337 

1.2:m9 

1.2401 

1 

12° 

1.2124 

1.2156 

1.2188 

1.2219 

1.2251 

1.2283 

1.2314 

1.2346 

13° 

1.2072 

1.2103 

1.2135 

1.2166 

1.2198 

1.2229 

1.2261 

1.2293 

a 

14° 

1.2018 

1.2049 

1.2081 

1.2112 

1.2144 

1.2175 

1.2207 

1.2238 

16° 

1.1963 

1.1995 

1.2026 

1.2057 

1.2089 

1.2120 

1.2151 

1.2183 

o 

16° 

1.1909 

1.1942 

1.1973 

1.2004 

1.2035 

1.2067 

1.2098 

1.2129 

.2  , 

17° 

1.1854 

1.1885 

1.1916 

1.1947 

1.1979 

1.2010 

1.2041 

1.2072 

S 

18° 

1.1799 

1.1831 

1.1862 

1.1893 

1.1924 

1.1956 

1.1986 

1.2017 

£ 

19° 

1.1743 

1.1774 

1.1805 

1.1836 

1.1867 

1.1898 

1.1929 

1.1960 

20° 

1.1687 

1.1718 

1.1749 

1.1780 

1.1811 

1.1841 

1.1872 

1.1903 

21° 

1.1G31 

1.1661 

1.1692 

1.1723 

1.1754 

1.1784 

1.1815 

1.1846 

22° 

1.1574 

1.1604 

1.1635 

1.1665 

1.1696 

1.1727 

1.1767 

1.1788 

§ 

23° 

1.1516 

1.1546 

1.1577 

1.1607 

1.1638 

1.1668 

1.1699 

1.1729 

H 

24° 

1.1457 

1.14«8 

1.1518 

1.1548 

1.1579 

1.1610 

1.1640 

1.1671 

L  25° 

1.1399 

1.1429 

1.1459 

1.1489 

1.1520 

1.1550 

1.1680 

1.1610 

776 

778 

780 

782 

784 

786 

788 

790 

Barometric  pressure  in  millimeters. 


INDEX. 


The  black  figare  indicates  the  page  upon  which  the  sabstance  is 
considered  in  chief. 


Abraln,  649. 

Abrin,  573. 

Absolute  temperature,  24. 

lero,  24. 
Absorption,  642. 

of  gases,  21,  688. 
coefficient  of,  688. 
Accipenserin,  589. 
Aoenapthalene,  496,  500.  • 
Acetal.  303,  806,  373. 

acrolein,  310. 

fflyceric,  310. 
Acetaldehyde,  302. 
Acetaldoxim,  409. 
Acetals.  306. 
Acetarnid,  400,  401. 
Acetamidin,  388. 
Acetanilid,  455,  476. 
Acetates,  330. 
Acetenylbenzene,  442. 
Acetbapiuin,  665. 
Acetochlorhydrose,  868,  465. 
Acetol,  308,  459. 

salicylate,  459. 
Acetonipmia,  308,  754. 
Acetonarains,  409. 

Acetone.  278.  807,  428,  442,  543,  625,  719, 
753,  755. 

diethylsulfone,  374. 

dimetbylsulfone,  374. 

ethyl-mercaptol,  373. 

phenylbydrazone,  486. 
Acetonitril,  388.  393.  894.  400,  401. 
Acetonuria,  620.  753. 
Acetophenone,  442,  466. 

oxim,  455. 
Acetophenyl  hydrazid,  486. 
Acetoxini,  382,  409. 
Acetoxims,  409. 
Acettoluids,  476. 
Acetyl  acetone,  512. 

benzene,  455. 

benzoylamin,  569. 

chlorid,  302,  330,  86S,  368,  369, 393,  398, 
400,  410,  455,  457,  475,  486,  499. 

cyanid,  398. 

hydrid,  302. 

bydroxid,  329. 

metbvlid,  307. 

morphin,  562. 

urea,  406. 
Acetylene,  236,  288,  302,  391,  423,  494,  433, 
442.  444,  495. 

balids,  426. 

series,  273. 
Acetylids,  425. 
Acbro5dextrins,  899,  643. 
Acid  (Hee  also  Acids). 

acetic,  288,  899. 


Acid,  acetobenzoio,  464. 

acetobydroxainio,  388. 

acetylacetic,  347,  719,  753,  766. 

acetylamidoacetio,  412. 

acetylpropionic,  347. 

aconitic,  346,  481. 

acrylic,  331,  342,  427,  499,  523. 

adenylic,  592. 

adipic,  331,  338. 
Acid  albuminates,  582,  690. 
Acid,  allanturic,  515. 

allopbanic,  407. 

alloxanio,  515,  527. 

alloxyproteic,  730. 

amidoacetic.  384,  395,  405,  407,  411,  412. 
413,419,  529,  634  (see  GlycocoU). 

amidobenzoic,  456. 

amidocarbonic,  389. 

amidoethylsulfonic,  421. 

amidoforraic,  402,  411  (see  Acid,  Gar- 
bam  ic). 

amidoglutaric,  419. 

amidoguanidin valerianic,  418  (see  Ar- 

ginin). 

amidobvdracrylic,  420. 

amidoiseth ionic,    421,    432,    634     (see 
Taurin). 

amidoisobutylacetic,  414. 

amidolactic,  411,  420. 

amidoraalonic,  411,  419. 

amidooxypropionic,  420. 

amidooxyvalerianio,  420. 

araidoph'enylacetic,  478. 

amidopropionic,  331,  411,  414,  623  (see 
Alanin). 

amidosuccinic,  419. 

amidosulfopropionic,  421,  422. 

amidothiohydracrylio,  421. 

amidothiolactic,  421. 

amidothiopropionio,  421. 

amidovaleriapic,  580,  581,  589,  595,  617. 

amygdalic,  466. 

amylsulfuric,  293. 

angelic,  429. 
Acid  anbydrids,  861,410. 
Acid,  anilidopropionic,  478. 

anilindisulfonic,  474. 

anilpyroracemic,  481. 

antbranilic,  456,  478. 

antbraquinoneraonosulfonic,  500. 

antitartaric,  344. 

antoxyproteic,  730. 

aracbic,  334. 

arsenic,  173,  174. 

arscnious,  172,  173. 

aspartic,  416,  419,  580,  595,  617,  629^ 
686,  763. 

atrolactic,  463. 

atropic,  467,  463,  553. 


(783) 


784 


INDEX 


Acid,  arirltellie,  586. 

MeUlc.  :i38. 

barbitario,  526. 

bensenemonosnlfonie,  469. 

beniend  sulfonie,  440,  444. 

bensene  trisulfonie,  469. 

benshydroxamic,  480. 

bensoie,  413, 418,  440.  441, 462, 4§6, 468, 
468,  479,  480, 492,  493,  606,  725. 

benBoylaeetic,  464. 

bensojlamidoaeetie,  479  (see  Aeid,  hlp- 
purie). 

bensoylformie,  463,  464. 

b«nsoylglycollie,  464. 

bemoylmalonic,  464. 

bensoylpropionio,  724. 

bensoylpyroncttmie,  464. 

bensoyltartronle,  463. 

bilianic.  635. 

bUiverdie,  638. 

biamutbie.  210. 

boraeio,  187. 

boric,  187. 

brassylic,  338. 

bromlc,  135. 

bromomercaptario,  ^2. 

bromopropionic,  341,  342. 

biomoprotocateehuie,  461. 

butylformie,  332. 

batvric,  SSI.  337,  601,  684. 

paehoutannic,  462. 

eaffeic,  462. 

oalfetannic,  462. 

campboglncnionie,  782. 

camphoric,  492. 

camphoronic,  338,  498. 

eapric,  333. 

eaproic,  332. 

oapryllc,  333. 

earbamic.  396,  40S,  411,  640. ! 

carbanilic,  480. 

carbazotio.  472. 

carbolic,  444  (see  Phenol). 

carbomandelic,  463. 

carbonic.  340. 

cerotic,  363. 

chelidonic.  517. 

cbloretbylsulfonic,  421. 

chloric,  133. 
Acid,  cblorids.  286. 
Acid  chlorlactic,  420. 

cliloropropionic,  352. 

choleic,  635. 

cholesteric.  6^^,  638. 

cbolic,  634,  636,  639,  640,  680. 

cholonic,  6.35. 

ciiolyHc.  635. 

chondroTtic,  594. 

chondroTtinsulfuric,  594,  596,  597,  740. 

chromic,  195. 

chrysophanic,  500. 

cinchomeronic,  519.  558. 

cinchoninic,  558,  559. 

cinnaiuic,  442,  455,  467,  479,  493,  525. 

citraconic,  346,  431. 

citric,  346,  431. 

comenic,  517. 

conmalic,  431. 

creaylic,  446. 

crotonic.  428,  429,  524,  756. 

cumic.  456. 

cyanic,  395,  896. 


Acid,  oyanoae«tic.  337,  396. 
cyanopropionlc,  337. 
cyanuric,  S«6, 404, 407, 408, 680, 887,  715. 
cymenesulfonie,  447. 
oysteic,  4SS,  640. 
decylic,  333. 
dehydroeholic,  636. 
d«lphinic,  332. 
deozycholic,  936. 
deztrolactic,  342. 
dextronic,  343. 
deztrotartaric,  314,  i44« 
dialuric,  527. 
dlamldoacetlc,  416. 
diamidocaproic,  417. 
diamidodithiodilaetic,  421,  7i7. 
diamidopropionie,  417. 
diamidocriozydodcean,  763. 
diamidoTalenanic,  417. 
diaaobeniene  tnlfonie,  516. 
dibensoyldiamidoeapioic,  480. 
dibemoyldiamidoTalerlanley  48S. 
dibromobenioic,  461. 
dibromomalonte,  348. 
dibromopropionle,  417. 
diohloracetic,  330,  346. 
dichromic,  195. 
diRallic,  461. 
dihydrocyanic,  399. 
dimalonic,327,338. 
dimethozybeniolc,  565. 
dimcthylmalonic,  626. 
dinitronaphthoUiilfoiite,  488. 
dlozycinnamlc,  462. 
diozjrmalonic,  347. 
diphenic,  499. 
ditulfanilic,  474. 
dithiocarbamic,  406. 
dithiodiamidodllafltto,  481. 
dithionic,  143. 
eUIdic,  430. 
ellagic,  649. 
erythritic,  342. 
erythroglncio,  297,  342. 
ethalic,  333. 
ethidenelactic,  341. 
ethidenematonic,  431. 
etbidenepropionio,  ^S, 
ethylacetic,  331. 
ethyldiacetic,  308. 
ethylenelactic,  342. 
ethylene  f^uccinic,  418. 
ethylmalonic,  334. 
ethylnitrolic,  376. 
ethyloxaraic,  403. 
ethylsulflnic,  372. 
ethylsiilfonio,  360. 

ethylsulfuric,  349,  859,  372,  423,  424. 
euxanthic,  732. 
fellic.  635. 
ferric,  199. 
fluorenic,  496. 
formic.  287,  297,  308,  SSS.  329,  341,  345» 

427,  428,  533. 
formylacetic,  362. 
fulminic,  396. 
fulminuric,  396. 
fumaric,  344,  430,  481,  601. 
furfurane  carbozyllc,  510. 
gadinic,  367. 
galactonic,  315. 
gallic,  450,  461. 


^^^^^^^^^^^^^^^^^ 

^ 

■        Acldp  gmllotannic,  461. 

Add,  Uatropic,  553. 

^1 

■                 geutiaiDlL%  4GQ. 

laethloDk,  r«72,  421, 

^^1 

■               glycouic,  314.  'J^5,  S48. 

iaobarbiturk,  529. 

^^1 

^M               glucosamic,  420, 

faobntylfDnnk,  332. 

^H 

■               glucovftnilllCt  4GG. 

iHobutyrJe,  332. 

^^^1 

■               Sluciironfr,  32G.  346.  S4I|  $09,  541,  684, 

iBOcrotook,  429, 

^^^M 

■                      7:i2. 

iflocywiic,  39«,  408. 

^^H 

H               glutactiDic,  4:it, 

taodialurlc,  529. 

^^^1 

■               glutamic.  410,  580,  617,  629,  763. 

tftoulcotlnk,  519,  548. 

^^H 

^L              gluumlnic  {«e«.>  GJuUniict. 

IsophtbBUc,  457. 

^^H 

^^K       sluCiiric,  3^,  337,  552. 

IflOpropylacetk,  332. 

^^H 

^^B       glyceric,  297.  3a  1.  342,  417.  420. 

fsopropytbetiKoic,  456. 

^^H 

^^V^       gtycerophoitphodf!,  365,  644. 

laopropylformi*',  332. 

^^^1 

V             glycocbollc.  413,  421,  636. 

isoftB«ch&ric,  510. 

^^^1 

^M              glycolamic,  413. 

iioatrychuic,  5<J0. 

^^H 

■               glycoUic,  295,  '£97,  301 ,  aSO.  339,  341, 413. 

Isofluccinie,  .334,  337. 

^^^1 

^M              glycoliirir,  407,  515. 

iaothlocyftiik,  397. 

^^H 

^M                g]jcc}s.urk',  46),  743. 

isovaleric,  3.32. 

^^^H 

■              glyoxylic,  269,  297,  ;130,  34S,  515,  713.      i 

Ijiovnnillir,  460. 

^^H 

^L             gTAphitie,  188. 

itaconk,  MH,  431. 

^^H 

^^^H        guanidjnhiityric,  418. 

kynuronic,  544. 

^^^1 

^^^H       gtitiiiylk,  592. 

kyourk.  541.  844. 

^^H 

^^^^^       guanyluuclek,  534, 

luctk,  3.31,  341,  428,  601.  620j  833,  884, 

^^M 

B                tiiBiHtttinic.  510,  664. 

731,  7*11. 

^^^H 

■         Acid  hiilid«,  EilipliKtic,  352. 

iBvolactk,  .342. 

^^H 

H                     aromatle,  468, 

Invotartark,  314.  344.  848, 

^^H 

■         Acid,  heptylic,  33:i. 

liBvulinlc,  347,  593. 

^^H 

H                hexaliydro-tetroxy  ben  zoic,  492, 

I  auric,  333. 

^^H 

B              hlppiiHe.  413,  414,  456,  479,  523,  606^ 

[ntiroiiteiirk,  333. 

^^^1 

■                      640,  720.  724,  7,i6. 

leuck,  [142. 

^^^1 

^B              bomogfintismic,  46L 

LlDoI«k.  429,430. 

^^H 

^m              horaoiirotocatechuic,  461. 

Ikbic,  528. 

^^H 

K             bydRotok,  406.  407,  515. 

lltbtifellk,  649. 

^^^1 

^^H,       bydrmcrylic,  331,  842. 

lyaurk.  419,  480. 

^^H 

^^B       bydrmzoic,  153. 

maletc,  430,  601. 

^^^1 

^^B       byclrindie,  54 K 

malk.  337,  344,  345,  419,  431,  46T. 

^^H 

V             hydHodlc,  136. 

Daalonamic,  403. 

^^H 

^m              bydrobrotnic,  134. 

tuatciok.  387,  526,  ^9, 

^^^1 

■              bydrochlornurlc,  193. 

maltouSr.  343. 

^^H 

■               bydroebloHr.  130,  609, 

maitdpile.  463, 

^^^1 

H              bydrochloroplatmk,  214. 

tnannonk,  298. 

^^^1 

^M               hydrocinnamic,  458. 

man noHMcc baric,  298. 

^^^1 

■               bydrocynnk ,  [WO,  329,  391 ,  398,  401,  410, 

tnargark,  333. 

^^H 

■                       413.  420.  425,  454,  4G6,  530,  537. 

meconlc,  517. 

^^^M 

^M              bydroflnoric,  126. 

mecoQlelc,  462. 

^^H 

■              bydroftuoHilicIc,  191. 

tnesacouk,  431. 

^^H 

^H               bydronltropniffsicv  399. 

mesoiarurk.  314,  344,  848,  430. 

^^^1 

^M               bydropiiracuiiiuBHc,  460. 

meHoxiitiL^  269,  347. 

^^H 

■               by  d  re>  p  1  lit  i  m>cy  irn  i  c ,  399 . 

met  a  bo  rk,  187, 

^^H 

^m              hydroquinone  carboxylic,  460, 

m^tahemipinic,  565. 

^^H 

■              bydroHuIfiirie.  139. 

metanltrous,  156. 

^^^1 

^H               bydroHiitlfiirmi!^,  144. 

metibtitiiiioiiotis,  1B5. 

^^^1 

^M              bypobmnious,  135. 

metapho^iphoric,  166,  188* 

^^H 

■              bypiichloroii?.  133. 

metaphoitphtiroua,  186. 

^^H 

■              bypo^ipk,  429. 

nietiirtietiik,  173,  178. 

^^^M 

■               byponitric,  155. 

m«tarae&ot)A,  173. 

^^H 

^M               bypordtroiiH,  IHG. 

m«ta*4taiizik,  212, 

^^^1 

^m               hypapb^pnphorlc,  i#(i,  IBS. 

metatimj^atic,  192. 

^^H 

^H                hypophoHphortmn.  166. 

methacrylic.  429. 

^^H 

^1              bypriAulfiirou!*,  143,  144, 147« 

roethylacetic,  330. 

^^H 

■               hypoxftiitbvik,  592. 

metbylacrylk.  524. 

^^^1 

■               Icbtbiiliiik.  586. 

raethykrotonic,  429. 

^^^1 

■               iDdiipr^dlHulfoTik.  542. 

metbykneHUcoinle,  431. 

^^H 

^1               indiifmnonofiitil funic,  542. 

meibyktbylttoetic,  332. 

^^^M 

^B               Itidolt^nt'^etfe,  540. 

mt'thylfnmaric,  431. 

^^^M 

^H               indultraniidoprtipionic:,  540 

iii«thv)t:imn{iUnac«tic,  389. 

^^H 

^1               Indoxvlj^diii'iironic,  ?29. 

methyl iuiik4t%  431. 

^^^1 

■               indrtxvlfr,  541. 

methyltnBlonic,  337. 

^^^1 

■               lndt»%^lHii]fiirk,  541,  723. 

inetbylpheiiolsiilfouk,  464, 

^^H 

■               lAdk','l37. 

methyl^iiccink,  :i34,  338. 

^^^1 

■              ioUo propionic,  331 »  428, 

miJDobmmoprfl plonk,  428, 

^^H 

H               Untolc,  542. 
1 

mouobromosuccinic,  431. 

J 

^^^^^^^^^^H 

786 


INDEX 


Acid,  monochloracetic,  8S0,  337,  384,  412, 
414,  479,  528,  529. 

morintannic,  462. 

morpbinsulfuric,  563. 

morphylsulfuric,  563,  673. 

luorrhuic,  571. 

mucic,  346,  510. 

muriatic,  130. 

myristic,  333. 

myronic,  467. 

uaphtbalenesulfonic,  498,  516. 

naphtbalic,  500. 

Dicotiuic,  619,  545,  551,  556. 

nitric,  157. 

Ditroacetic,  410. 

nitrocinnamic,  539,  542. 

nitrobydrochloric,  131. 

nitrophenylacetic,  541. 

Ditrosomalonic,  419. 

nitrosulfonic,  155. 

nitrotijluol sulfonic,  480. 

nitrous,  156. 

nonylic,  333. 

octylic,  333. 

oenantbylic,  333. 

oleic,  334,  429. 

opianic,  463,  464,  564,  666. 

omitburic,  418,  480. 

orsellinic,  461. 

ortboamidobenzoio,  478. 

ortboamidobenzoylformic,  478. 

ortboamidoraandelic,  478. 

ortboaraidopbenylacetic,  478. 

orthoar.Henic,  173. 

ortboboric,  187. 

orthocarbonic,  107. 

ortbodiazindicarboxylic,  520,  681. 

orthopbenylsulfonic,  470. 

orthopbospboric,  167. 

ortbotoluic,  462. 

orthovinylbenzoic,  457. 

orthoxybeiizoic,  459. 

ortboxvparatoluic,  460. 

osinic.'l92. 

oxalic,  283,  295,  297,  298,  308,  318,  321, 
.328,  329,  330,  334,  336,  341,  M2,  345, 
350,  3.5H,  424,  525   530,  731. 

oxahiric,  408,  527,  725. 

oxaiiiic,  401,  403. 

oxanilic,  478,480. 

oxyacetic,  341. 

oxyainidopropionic,  420. 

oxyljuTyric,  342,  753,  756. 

oxycuproic.  342. 

oxy formic,  340. 

oxyj<lutaric,  337,  344. 

oxyisol)utyric.  339. 

oxymaloiiic,  344. 

oxymethylbenzoic,  504. 

oxyplifuic,  448. 

oxyplu'iiyilnctic,  581. 

oxvplK'Uvlpropicnic,  581. 

oxy  propionic,  ;{;{9,  341.  347,  428. 

oxypr(»toic,  7M). 

oxyproto»<nlfoiiic,  579. 

oxycjuinolincarltoxylic,  544. 

oxvMilicylic,  449. 

oxvsucciiiic.  ;U4. 

palmitic.  333,  429. 

paraamidobenzeneRulfonic,  474. 

parabanic.  616,  530. 

paralactic,  342. 


Acid,  paraoxyhydratrople,  467. 
paraoxypbenylacetic,  460,  647. 
paraoxyphenylglycoUic,  460. 
paraoxyphenyl  propionic,  460,  647. 
parapbenylacetic,  400. 
parasorbic,  430. 
paratartaric,  344. 
pelargonic,  333. 
pentatbionic,  143. 
pentoxypimelic,  346. 
pepRobydrochloric,  611. 
perbromic,  135. 
perchloric,  133. 
periodic,  137. 
peroxyprotonic,  579. 
perftulfuric,  143,  147. 
pbenic,  444. 
pbenylacetic,  456,  582. 
pbenylacrylio,  525,  563. 
phenylamidopropionic,  478,  680,  582. 
phenylglucuronic,  728. 
pbenylglyceric,  463. 
phenylglycollic,  463. 
phenylhydracrylic,  563. 
phenylisocrotonic,  495,  498. 
phenylmalonic,  457. 
phenyloxy propionic,  458. 
phenylpropiolic,  458. 
phenylpropionic,  582. 
pbenylsnlfuric,  470,  728. 
pbloretic,  467. 
pbocenic,  332. 
pboenicin sulfonic,  642. 
pbospbatic,  168. 
pbosphocarbonic,  655. 
pbospboglyceric,  365. 
pbosphomolybdic,  192,  548. 
pbo8pboric,'l66,  167. 
pbo«pborou>*,  166,  167. 
pbospbotungstic,  192. 
pbtbalamic.  464,  477,  478. 
phtbalic.  444,  467,  462,  468,  495,  501. 
pbthalidacetic,  464. 
picolonic,  519. 
picric,  459,  472,  475,  494. 
pimelic,  338,  459. 
piperic,  468,  550. 
pivalic.  332. 
plumbic,  205. 
propargylic,  4.30. 

propeny'lpentacarboxylic,  327,  338. 
propiolic.  430. 
propionic,  330.  341. 
propyl  acetic,  332. 
protocatecbuie,  460,  461. 
prussic,  391. 
pseudouric.  .*)26,  529. 
purpuric,  527. 
pyrazoledicarboxylic,  512. 
pyridintartronic,  556. 
pyridintricarboxylic,  565,  566. 
pyroaiitimonic,  185. 
pyroaraenic,  173,  174. 
pyroarsenous,  173. 
pyrohismutbic,  210. 
pyroboric,  187. 
pyrocbolesteric,  635. 
pyro^allic,  450. 
pyromucic,  346,  510. 
pyropbospboric,  166,  168. 
pyropbospborous,  166. 
pyroraciMiiic,  .341,  347,  481. 


INDEX 


787 


Add,  pyrosulfuric,  143,  147. 

pyrotartario,  337,  338,  345. 

pyrrolidincarbozylic,  589,  596. 

pyruvic,  347. 

quercitannic,  462. 

qninic,  449,  452,  49S,  556,  559. 

quinolinic,  519. 

quinotannic,  462,  556. 

quinovic,  556. 

racemic,  314,  344,  846,  430. 
Acid  reaction,  62. 
Acid,  rbeic,  500. 

ricinoleic,  430. 

rocellic,  338. 

rosolic,  444,  450. 

saccharic,  319. 

salicylic,  444,  453,  457,  469,  468,  478. 

salicylous,  454. 

sebacic,  3.38,  429. 

silicotungstic,  192. 

skatoleacetic,  581. 

sicatolecarboxylic,  540,  581,  646,  647. 

sorbic,  430. 

sozolic,  470. 

stannic,  212. 

stearic,  333. 

strychnic,  560. 

suberic,  338. 

succinamic,  408,  408,  419. 

succinic,  287,  331, 334,  887, 345, 431,  761. 

sulfanilic,  474,  516. 

sulfhydric,  139. 

sulflndigotic,  542. 

sulflndylic,  542. 

sulfocarbamic,  405. 

sulfocyanic,  396. 

sulfothiocarbonic,  374. 

sulfovinic,  359. 

sulfuric,  143,  144. 

sulfurous,  142,  143,  144. 

tartaric,  297,  313,  844,  347. 

tartronic,  344. 

taurocarbamic,  421,  640,  730. 

taurocholic,  421,  686,  639. 

terebic,  492. 

terephthalic,  457. 

terpenylic,  492. 

tetraboric,  187. 

tetraoxyamidocaproio,  420,  594. 

tetrath  ionic,  143. 

thioacetic,  374. 

thioamidopropionic,  421. 

thiobenzoic,  469. 

thiocarbamic,  405. 

thiocarbonic,  396. 

thiocyanic,  373,  396. 

thiolactic,  374,  580. 

thioxyarsenic,  173. 

thiosulfuric,  143,  147. 

thymic,  593. 

thymus-nucleic,  524. 

tifirlic,  429. 

tricarballylic,  327,  338,  431. 

trichloracetic,  304,  880,  737. 

trichroiuic,  195. 

tricyanic,  396. 

trihydrocyanic,  399.  537. 

triraethylacetlc,  3:^2. 

trimethyltricarballylic,  493. 

trinitrophenic,  472. 

trioxycholesteric,  638. 

trithiocarbonic,  374. 


Acid,  trithionic,  143. 
triticonucleic,  593. 
tropic,  457,  468,  563,  554,  555. 
uric,  403,  405,  413,  414,  515,  622,  524,  627, 
6S8,  529,  530,  531,  632,  534,  684, 686, 
709,  710,  720,  721,  722,  723,  759. 
urochloralic,  732. 
uroferric,  731. 
uroleucic,  461. 
uroproteic,  731. 
urous,  532. 
Talerianic,  332. 
Tanillic,  454,  460. 
veratric,  449,  460,  566,  669. 
Tinylbenzoic,  457. 
xanthic,  532. 
xauthylic,  592. 
jeast-nucleic,  623,  593. 
Acidism,  754. 
Acidosis,  754. 

Acids,  63,  115,282,  283  (see  Aeid). 
acetic  series,  327. 
acetylene  monocarbozylie,  430. 
alcohol,  338. 
aldehyde,  346. 

ketone,  347. 
alkyl-acetic,  330. 

amic,  379. 

benzoic,  456. 

dithiocarbamic,  397. 

sulfuric,  349. 
amic,  399,  401,  411,  478,  480. 
amido,    411,   579,   581,    631,  646,  686, 
686,  756. 

butyric.  412,  414. 

caproic,  414.  ' 

cinnamic,  478. 

dicarboxylic,  419. 

jflyceric,  420. 

lactic,  420. 

phenyl,  477,  478. 

propionic,  414,  420. 

succinic,  419. 

thio,  421. 

thiolactic,  421. 

valerianic,  414. 
anil.  481. 
anilic.  480. 
anilido,  478,  479,  480. 
anthracenecarboxylic,  500* 
aromatic  alcohol,  462. 
dicarboxylic,  463. 

aldehyde,  464. 

amido,  470,  477. 

carboxylic,  455. 

dioxyalcohol,  463. 

dioxycarboxylic,  460. 

ketone,  464. 

monocarboxylic,  455. 

nitro,  473. 

polycarboxylic,  456. 

sulfonic,  456,  469. 

trioxycarboxylic,  461. 

unsaturated,  457. 
azofatty,  380. 
basicity  of,  63. 
benzene  dicarboxylic,  46T. 

disulfonic,  469. 

sulfonic,  444. 
benzenic,  443. 
benzoic  series,  465. 
benzoylbenzolc,  504. 


788 


INDEX 


Acids,  benzyl  alcohol,  463. 
biliary,  684,  639,  645. 
bromacetic,  330. 
bromobensoic,  459. 
bromopropioDic,  331. 
camphoric,  492. 
caproic,  332. 
carbopyridic,  517,  519. 
carboxylic,  283,  887. 
chloracetic,  330. 
chtoropropionic,  331. 
crotonic,  429. 
cyanofatty,  335,  896,  412. 
diamidobutyric,  417. 
diamidocaproic,  418. 
diamidofatty,  416,  477. 
diamidovalerianic,  417,  418. 
diatropic,  458. 
dibromofatty,  417. 
dicarbozylic,  328,  362,  395. 
diketone  monocarboxylic,  347. 
dimethyluric,  531. 
diolefln  monocarboxylic,  430. 
dioxybenzoic,  460,  461. 
dioxydicarboxylic,  344. 
dioxyethylene  succinic,  344. 
dioxymonocarboxylio,  3^. 
dioxyphenyl,  461. 
dioxytolulc,  461. 

dipbenylmethane  carboxylic,  504. 
dithiocarbamic,  406. 
fatty,  327,  428. 
fluorene  carboxylic,  500. 
gluconic,  314,  315,  848. 
glyceric  series,  342. 
^lycocholic,  634. 
^anylic,  593. 
hematiuic,  510. 

halid  fatty,  328,  330,  335,  339,  368,  412. 
hexylic,  332. 
hydroaroraatic,  491,  492. 
hydrometallocyanic,  399. 
hydrophtbalic,  457. 
hydroxamic,  388,  480. 
indi^osulfuric,  542. 
iodacetic,  330. 
lodopropionic,  414. 
isatropic,  458. 
ketonie,  307,  347. 
lactic,  341,  414. 
leucic,  415. 
mannonic,  343. 
maDDOsaccharic,  343,  346. 
mercapturic,  422, 
methylpseudouric,  526,  531. 
nietbyluric,  531. 
monatnido,  411,  589. 
•nonamidoxy,  420. 
monocarboxylic,  362. 

aromatic,  455. 
monochlor  fatty,  395,  411  412. 
monolialid  fatty,  413,  428. 
monoketone  monocarboxylic,  347. 
mouoxydicarboxylic,  343. 
naphthalene  carboxylic,  500. 

sulfonic,  500. 
naphthoic,  500. 
naphthol  carboxylic,  500. 

sulfonic,  498. 
naphthylamin,  sulfonic,  501. 
naphthyl  fatty,  500. 
nitrilic,  394,  395. 


Acids,  nitro,  410,  412. 

nitrobenzenio,  473,  478. 

uitrocinnamic,  458. 

nitrolic,  376. 

nitruprupionic,  414. 

nucleic,  .')23,  5.*^,  588,  591,  59S. 

nucleinic,  :iVZ. 

of  antimony,  UO. 

arsenic,  173. 

nitrogen,  156. 

phosphorus,  166. 

sulfur,  143. 
olefin  dicarboxylic,  335,  430. 

monocarboxylic,  430. 

tricarboxylic,  431. 
oleic,  428. 
ortho,  167. 
oxalic  series,  334. 
oxyacetic.  339,  428. 
oxyaldehyde,  348. 
oxy  ben  zoic,  459. 
oxy butyric,  .340,  342,  4 IS. 
oxycaproic,  415. 
oxyketone,  348. 
oxymethylbenzoic,  462. 
oxy  propionic,  341.  342. 
oxypyrrolidincarboxylic,  579,  580. 
oxy  tricarboxylic,  346. 
paraffin  dicarboxylic,  334. 

monocarboxylic,  327. 

pentacarboxylic,  338. 

tetracarboxylic.  338. 

tricarboxylic,  338. 
pentoxydicarboxylic,  346. 
pentoxymonocarboxylie,  343. 
phenanthreue  carboxylic,  497. 
phenol  carboxylic,  458. 

sulfonic,  444,  470. 
phenyl  acrylic,  457. 

alcohol,  463. 

alcohol  ketone,  464. 

amido,  477. 

diketone,  464. 
phenylene  ketone  dicarbozylic,  464. 
phenyl  fatty,  456. 

hydracrylic,  463. 

ketone,  dicarboxylic,  464. 

lactic,  463. 

olefin  carboxylic,  457. 

paraffin  alcohol,  462,  463. 

propionic,  413,  456,  458. 
phthalic,  457. 
phthalid,  464. 
picolinic,  519. 

polycarboxylic  aromatic,  456. 
pure,  327. 
pyridin,  carboxylic,  519. 

dicarboxylic,  519,  558. 
pyrrolidincarboxylic,  511,  579,  580. 
quinolin  carboxylic,  558. 
residue  of,  63. 
resorcylic,  460. 
saccharic,  346. 
sulflnic,  360,  372   469. 
sulfobenzoic,  458. 
sulfonic,  300,  370,  37». 
sulfurous.  144. 
tannic,  461. 
tartaric,  .'US,  344. 
taurocholic,  634/ 
tetracarboxylic,  338. 
tetroxydicarboxyllc,  346. 


INDEX 


789 


Acids,  tetroxymonocarboxylio,  343. 

thio,  370,  374. 

thiocarbamic,  405. 

thiosulfonic,  372. 

thymonucleic,  524,  525,  592,  593. 

toluenesulfonic,  469. 

toluic,  441,  457. 

tricarboxylic,  338. 

trioxycarboxylic,  346. 

trioxymonocarboxylic,  342. 

tropidincarboxylic,  555,  556. 

unsaturated  aromatic,  457. 

valerianic,  332,  417. 

volatile  fatty,  327. 
Acidulous  elements,  125. 
Acidyl  anhydrids,  406. 

chlorids,  300,  351,  393,  398,  400,  406,  446, 
504. 

cvanids   393   398. 

halids,  300,  307,  328,  t6S,  359,  401,  410. 

hydroxids,  328. 

oxids,  282. 
Acidylens,  334. 
Acidyls,  328. 
Acipiperazins,  522. 
Aconin,  569. 
Aconite  alkaloids,  568. 
Aeonitin,  568,  669. 
Acridin,  5.38.  644. 
Acrolein,  296,  297,  426,  427,  428. 

acetal,  310. 

bromid,  314. 
Acrososazone,  388. 
Actinic  power,  39. 
Actinium,  55,  103. 
Acyclic  compounds,  271,  278. 
Acylation,  369. 
Addiment,  672,  675. 
Addition.  269. 

Adenin,  532,  534,  686,  536,  593. 
Adipocere,  582. 
Adjacent  positions,  437. 
Adonite,  298. 
^sculetin,  466. 
^sculin,  466. 
^thiops  mineralis,  256. 
Affinity,  86. 
After-damp,  275. 
Agate,  191. 

Af^glntinins,  670,  672,  675. 
Air,  149. 

alveolar,  688. 

ammonium  oomponnds  In,  150. 

analysis  of,  356. 

carbon  dioxid  in,  355,  356,  357. 

solid  particles  in,  150. 
Alabaster,  237. 
Alanin,  414,  420,  580,  595,  596,  721,  757, 

763. 
Alanins,  412,  414  (see  Acids,  unidopropi- 

onic). 
Alanylalanin,  416. 
Albamin,  617. 
Albite,  248. 
Albumen,  584. 
Albuminates,  582,  689,  612. 
Albuminoids,  583,  696,  619. 
Albumins,  582,  688. 

coagulated,  590. 

coagulating,  582,  686. 

derived,  582,  689. 

native,  582,  688,  689,  590,  691,  624. 


Albumins,  true,  582,  583. 

Albuminuria,  734,  788. 

Albumoid,  583,  595. 

Albumoses,  582,  612,  628,  646,  736,  737; 

deutero,  618. 

primary,  618,  616,  624. 

secondary,  613,  616,  615,  616,  618,  6S 
Albumosuria,  739. 
Alcohol,  287  (see  Alcohols). 

absolute,  288. 

acids,  338. 

allyl,  426,  427,  428. 

amidoethyl,  408. 

amylic,  292,  293,  521. 

benzylic,  443,  452. 

bromallylic,  427. 

butylic,  601. 

cetylic,  294. 

cinnamic,  453. 

coniferyl,  466. 

crotonyl,  427. 

epichlorhydrin,  351. 

ethene,  295. 

ethers,  350. 

ethylio,  287,  400. 

fluorene,  499. 

isobutylic,  601. 

methylic,  286,  300. 

nitroethylic,  408. 

oxybenzylic,  453. 

propargylic,  426,  427. 

propenyl,  296. 

propylic,  427. 

trichlor,  732. 

vinyl,  426. 
Alcoholates,  286,  289,  328,  349. 
Alcoholic  beverages,  290. 

fermenUtion,  600. 
Alcohols,  284,  302,  379. 

acetylene,  427. 

allyl,  299. 

amido,  408. 

amylic,  292. 

aromatic,  452,  453,  454,  458. 

benzenic,  443. 

butylic,  292. 

eamphan,  491. 

diatomic,  282,  284,  294. 

dlhydric,  282,  284,  294. 

diolefln,  477. 

diphenyl,  503. 

diprimary,  285.  294. 

heptatomic,  298. 

hexatomic,  284,  298. 

hexahydric,  284,  298. 

hydroaromatio,  489. 

iso,  285. 

menthan,  490. 

menthene,  490. 

monoatomie,  284. 

napthyl,  499. 

nomenclature  of,  284,  885^ 

nonatomic,  298. 

octatomic,  298. 

olefin,  426. 

oxyphenyl,  453. 

pentatomic,  284,  297. 

pentahydric,  284,  297. 

polyatomic,  297. 

polyhydric,  297. 

primary,  282,  283,  286,  877» 

propylic,  291. 


790 


INDEX 


JUeoholfi,  rinft,  489. 

secondary,  2«2.  283.  SM,  307,  377. 
ring,  489»  490. 

tMrpan,  489,  490. 

tertiary,  282,  283,  %B§,  377,  443. 

tetnitomie,  284,  B97. 

tetrahydrie,  284,  S97. 

triatomio,  284,  S9«. 

trihydrio,  284,  S9«. 

tropan,  552. 
Ald^yde,  acetic,  802,  806,  409. 

aeida,  839,  340,  StO. 

acrylic,  427. 

aleohole,  299,  808. 

•llyl,  428. 

amldobensolc,  543. 

ammonia,  300,  302,  «09,  517,  518. 

anUic,  454. 

bentoie,  443,  «i8, 457, 458, 468, 466, 468, 
503,  504,  505. 

betain,  386. 

butyric,  305,  560. 

elnnamlc,  454. 

crotonic,  302,  427. 

eumlnlc,  447. 

formic,  299,  800, 306,  373,  380,  404, 409, 
413,603,514. 

farfario,  509. 

glyceric,  306,  810,  600. 

glycoUic,  299,  810, 420. 

Sreen,  506. 
alide,  277. 

hydrfttes,  306. 

liydrasones,  410. 

isoTaleriCr  414. 

ketones,  808,  396. 

methylprotooateehnic,  454. 

<»Eybatyric,  487. 

propargyl,  428. 

propionic,  305. 

SHlicyllc,  453,  454,  468,  539. 

thioformic,  373. 
Aldehydin,  518. 

Aldehydes,  282,  283,  284,  286,  298,  899,  324, 
325,  326,  339,  352,  391,  398,  409,  484, 
517,  543,  544. 

acetylene,  428. 

aromatic,  453,  456. 

benzenic,  443. 

diolefin,  428. 

naphthyl.  499. 

olefin.  427,  428. 
Aldehydrazones,  485. 
Aldohexoses,  310,  343. 
Aldol,  300,  308,  420,  427. 
Aldopentoses,  310. 
Aldoses,  309,  310.  .324,  325,  326,  485. 
Aldoxiras,  379,  398,  409,  410. 
Ale,  290. 

Aleurone  corpuscles,  587. 
Alexins,  672. 
Al^roth,  powder  of,  184. 
Aliphatic  compounds,  271,  273. 

unsaturated,  423. 
Alisarin,  495,  499. 

dyes,  495. 
Alkali,  215. 

albuminates,  582,  590,  629. 

carbonated,  215. 

caustic,  215. 

metals,  215. 

volatile,  151. 


Alkaline  esrtbs,  metals  o^  888. 

reaction,  62. 
Alkaloids,  545. 

aeonite,568. 

atroplc,  552. 

oincnona,  556. 

classification  of,  548. 

general  reactions  of,  648« 

isoqninoUn,  548,  §08. 

opium,  544,  §88. 

pbenanthrene,  548,  §08. 

piperidein,  548,  649. 

piperidin,  548,  §49. 

pyridin.  548,  §49 

pyrrolidin,  548. 
piperidin,  548,  §§8. 
pyridin,  548,  §§1. 

qninolin,  548,  §§0. 

separation  of,  547. 

stryehnos,  559. 

tropan,  552. 
Alkanes,  274. 

Alkaptonuria,  460,  461,  748. 
Alkarsin,  422. 
Alkyl,  294. 

amids,  401. 

ammonium  iodids,  879. 

bensenes,  440. 

eysnidins,  537. 

eyanids,  277,  894. 

baUds,  877,  286,  307,  849,  309,  SH,  878, 
379,  464. 

bydrids,  274. 

indoles,  540. 

iodids,  379,  382. 

isocyanids,  394. 

mereaptopyrimidlns,  584. 

psendothiouress,  523. 

pyridine,  518. 

pyridinum  iodids,  518. 

thiopseudoureas,  406. 

ureas,  402,  406. 
Alkylation,  370. 
Alkylen  dicyanids,  395. 

oxids,  350,  382. 
Alkylens,  294,  350. 
Allantoln,  515,  527,  530,  713,  725. 
Allene,  425. 
Allometa  position,  438. 
Allortho  position,  438. 
Allotropy,  17. 

Alloxan,  348.  403,  515,  52C,  587,  530. 
Alloxantin,  526,  687,  530. 
AUoxuric  bases,  531. 
Allyl  alcohol.  299. 

amin,  432. 

anilin,  543. 

bromid,  4:»,  552. 

eyanids,  428. 

guaiacol,  450. 

halids,  426,  428. 

iodid.  426,  431,  4.')2. 

isothiocvanate,  397,  488,  467. 

oxid,  431. 

phenol,  450. 

pyrocatecliol,  450. 

sulfid,  4.32. 

tetraoxvbenzene,  450. 

tribroniid,  296. 
Allylene,  425.  442. 
Alpbenols,  453. 
Alumina,  246. 


INDEX 


791 


Alaminates,  245,  246,  247. 
Aluminium,  245. 

chlorid,  247,  441,  455,  464,  477,  495,  499, 
501,  502,  504. 

fi^roup,  245. 

hydroxid,  246. 

oxid,  246. 

silicates,  248. 

sulfates,  247. 
Alums,  247. 
Amalgams,  255. 
Araauitin,  888,  385. 
Amber,  XMj  493. 
Ambergris,  649. 
Amboceptor,  672,  675. 
Ambrain   649. 
Amid,  amidoglutario,  420. 

benzoyl,  477. 

glycocoll,  407. 

sarcosin,  407. 

ethylene-ethenyl,  385. 
Amidins,  388. 
Amido  acetaldehyde,  409,  521. 

acetones,  409. 

acids,  411. 
aromatic,  477. 

alcohols,  408. 

aldehydes,  409. 

azo  compounds,  483. 

benzenes,  471,  473,  501. 

cyanidins,  537. 

diphenyls,  502. 

group,  380,  413. 

guanidin,  389. 

ketones,  409. 

ketopuriu,  534. 

malononitril,  391,  395,  537. 

malonylurea,  526,  529. 

napthalenes,  500. 

paraffins,  376,  377. 

phenyl  acids,  478. 

phenols,  448,  473,  477. 

purin,  535. 

thioacids,  421. 

toluyls,  502. 

triphenyl  carbinols,  506. 
methanes.  505. 

uracil,  529. 

xylenes,  474. 
Amidoxims,  888,  481. 

Amids,  328,  379,  388,  395,   899,   407   (see 
Monamids,  Diamids). 

amidosuccinic,  419. 

aromatic,  470,  477. 

mixed.  .399,  401. 

of  dicarboxylic  acids,  401. 

primary.  399. 

secondary,  399. 

tertiary,  399. 
Amin,  allyl,  432. 

bases,  377. 

nitrosodimethyl,  380. 

trimethyltrimethylene,  380. 

vinyl,  432. 
Amins,  286,  301,  877,  381,  397,  401,  406,  410, 
413,  581  (see  Monamins,  Diamins). 

aromatic,  302,  470. 

cyclic.  380. 

mixed,  377. 

naphthyl.  499,  500. 

nitroso,  380. 

primary,  880,  394,  397,  482. 


Amins,  secondary,  302,  482. 

simple,  377. 

unsaturated,  382. 
Ammelid,  404,  537. 
Ammelin,  537. 
Ammeter,  45. 
Ammonia,  151. 

caustic,  232. 
Ammonias,  compound,  377. 
Ammonio-magnesian  phosphate,  241,  705. 
Ammonium,  151,  232. 

acetate,  234. 

amalgam,  232. 

bromid,  233. 

butyrate,  332. 

carbamate,  402,  403,  681,  685,  686,  712. 

carbonates,  234,  402,  685,  712. 

chlorid,  2:^. 

cyanate,  262. 

derivatives,  .377. 

hydroxid,  232. 

iodid,  2:^. 

isocyauate,  403. 

isothiocyanate,  406. 

nitrate,  233. 

nitrite,  380. 

sesquicarbonate,  234. 

sulfamate,  232. 

sulfates,  233,  234,  576. 

sulfhydrate,  233. 

sulflds,  233. 

theory,  232. 

urates,  .~)31,  720,  723,  759. 
Ampere,  44. 
Amphocreatinin,  390. 
Amphopeptone,  616. 
Amphot«»ric  elements,  101,  193.^ 
Amygdalin,  391,  453,  466. 
Amyl  acetate,  363. 

caprate,  333. 

chlorid,  293. 

cyanid,  332. 

nitrate,  362. 

nitrite.  363. 
Amylamin,  415. 
Amylase,  605,  6.54. 
Amylene,  294,  425. 

hydrate,  294. 
Amylodextrin,  643. 
Amyloid,  583.  597. 
Amylopsin,  627,631. 
Amylum,  320. 
Anachlorhydria,  619,  643. 
Analysis,  62,  115.599. 

organic,  265. 
Analytical  chhracters  of  alcohol,  289. 

aluminium,  248. 

ammonium,  234. 

anilin,  474. 

antimony,  181,  186. 

arsenic,  178. 

atropin,  554. 

barium,  239. 

bismuth,  210. 

bromidion,  134. 

brucin,  .561. 

cadmium,  245. 

calcium,  238. 

carbolic  acid,  445. 

chloridion,  132. 

chloroform,  279. 

chromium,  195. 


792 


INDEX 


Analytieal,  eobali,  Uk 

cocalu,  556. 

ooniln,  550. 

copper,  253. 

eyanids,  392. 

gold,  194. 

hydrogen,  108. 
salfld,  141. 

iodidion.  137. 

iron,  2S03. 

lead,  207. 

lithium,  «16. 

magneeiam,  ^272. 

manganese,  196. 

mereary,  260. 

morphin,  563. 

niekel,  249. 

nieotin,  661. 

nitrates,  158. 

oxalates,  336. 

oxygen,  112. 

oaone.  112. 

phenol,  445. 

phosphates,  lA. 

phospboms,  16I. 

potassium,  229. 

quinin,  557. 

silTer,  231. 

sodium,  221. 

strontium,  238. 

strychnin,  560. 

sulfates,  146. 

sulflds,  141. 

sulfur  diozid,  148. 

tin,  213. 

line,  244. 
Anethol,  450,  454. 
Anglesite,  204. 
Anhydrid,  acetic,  861, 969,  406, 486,  689. 

antimonie,  184. 

antimonous,  184. 

arsenic,  172. 

arsenous,  172. 

benzoic,  468,  480. 

boric.  187. 

carbonic,  354. 

chromic,  195. 

citraconic,  431. 

glycocoll,  412,  416,  522. 

itaconic,  431 

leucin,  522,  630. 

maleic,  344,  419,  480. 

manganic,  196. 

manjcanotis,  196. 

molybdic,  192. 

nitric,  156. 

nitrous,  154. 

phosphoric,  166. 

phosphorous,  166. 

phthalic,  449,  450,  451,  462,  468,  477. 

plumbic,  205. 

silicic,  191. 

succinic,  337. 

sulfuric,  143. 

sulfurous,  142. 

tiUnic,  211. 

tungstic,  192. 
Anhydrids,  84,  111,  282,  286,  300,  328,  335, 
861. 

aromatic,  468. 

benzenic,  443. 

cyclic,  412. 


Anhydrids,  mixed,  352. 

of  monamido  adds,  882. 

thio,  141,  374. 
Anbydroeegonin,  555. 
Anbydrogeranioi,  426. 
AnUido  acids,  479. 
Anilids,476,480. 

of  diearboxylic  acids,  478. 
AnUin,  471,  47S.  475, 476,  479,  481, 481, 488. 
484,  505,  509.  522,  640,  648. 

derivatiTes  of,  475. 

dyes,  476.  481,  483,  506. 

red,  506. 
Aniline,  543. 


Animal  gum,  654. 
Anions,  44, 72. 
Anisidins,  472.  477. 
Anisol,  464.  , 
Annidalin,  448. 
Anode,  41. 
Anol,  450. 
Anthracene,  493,  4M,  497. 

haUda,  497. 

nitrogen  deriyatiTes  of,  608. 

oU,  440. 
Anthracite,  188. 
Anthranol,  499. 
Anthraphenols,  498. 
Anthrapyridins,  638. 
Anthraquinolins,  538. 
Anthraquinone,  485,  496, 499. 
Anthiols,  499. 
Antialbumid,  618,  618,  629. 
Antifebrin,  476,  513. 
Anti  bodies,  670. 
Anti  group,  612,  618. 
Antihnmolysins,  672. 
Antimony,  148,  188. 

acids  of,  185. 

antimonate,  185. 

black,  185. 

butter  of,  184. 

chlorids  of,  183. 

cinnabar,  186. 

crocus  of,  185. 

glass  of,  185. 

intermediate  oxid  of,  185. 

liver  of,  185. 

organic  compounds  of,  422. 

oxids  of,  184. 

oxychlorid,  184. 

oxysulfids,  186. 

pentachlorid,  184. 

penUsulfid,  186. 

pentoxid,  184. 

sulflds  of,  185. 

tartarated,  227. 

tricblorid,  183. 

trioxid,  184. 

trisulfld,  185. 

vermilion,  186. 
Antimonyl,  227. 
Antipeptones,  629. 
Antipyrin.  484,  512,  618. 

salicylate,  514. 
Antitoxins,  669,  670,  673,  674* 
Antitussin,  502. 
Apiol,  450. 
Apo  alkaloids,  547. 
Apoatropin,  554, 
Apomorphin,  562,  666. 


INDEX 


793 


Apoquinin,  558. 
Aquu  ammonis,  151. 

fortis,  157. 

regia,  131,  158. 

sapphirina,  252. 
ArabiD,  321. 
Arabiuose,  810,  321. 
ArbacioD.  588. 
Archil,  449. 
Arecaldin,  548,  549. 
Arecain,  548,  549. 
Arecoliu,  548,  549. 
Arginin,  403,  417,  418,  480,  580,  581,  586, 

589,  595,  617,  629,  632,  757,  763. 
Argol,  226. 

Argon,  55,  101,  103,  125. 
Aricin,  556. 
Aristol,  447. 

Aromatic  conipoands,  272.  48i,  439. 
Arragonite,  237. 
Arsenamin,  170. 
Arsenic,  148,  169,  172,  175. 

disulfid,  174. 

organic  compoands  of,  422. 

pentasulfld,  174. 

pentoxid,  172. 

tribromld,  171. 

trlchlorid,  171. 

trifluorid,  171. 

triiodid,  171. 

trioxid.  172,  175. 

trisulfld,  174. 
Arsenites,  172. 
Arsin,  dimethyl,  422. 
Arsiuia,  170. 
ArsiuA,  422. 
Arterin,  659. 
Artiads,  59. 
Asbestos,  240. 
Asellin,  367. 
Aseptol,  470. 
Asparagins,  403,  419. 
Aspergillus,  601,  602. 
Asymmetric  carbon  atom,  312,  313. 
Atmosphere,  149,355. 

ammoniacal  compounds  in,  150. 

carbon  dioxid  in,  150,  365. 

nitrous  acid  in,  150. 

solid  particles  in,  150. 

snlfurous  acid  in,  160. 

water  in,  150. 
Atom,  53. 
Atomic  heat,  55. 

rearrangement,  62. 

theory,  52. 

weight,  M. 
Atomicity,  59,  .339. 
Atropamln,  554. 
Atropiti,  463,  548,  552,  668. 
Auric  chlorid,  193. 
Aurin,  450. 
Auroamidoimid,  396. 
Anrous  chlorid,  193. 
Autodigestion,  630. 
Autolysis,  628,  629,  680. 
Avogadro,  postulate  of,  52. 
Azins,  520. 

Azobenzene,  488,  484,  502. 
Azo  compounds,  380,  470,  481,  488(  498. 
Azoimid,  152. 
Azoles,  511. 
Azonaphthol  compounds,  498. 


Azoxy  compounds,  482,  483. 
Azurite,  252. 

Bacillus  acidi  laBvolactici,  342. 
Bacteria,  581. 

Bacterial  fermentations,  601. 
Bacterium  aceti,  329. 
Bacteriolysins,  671. 
Baking  powders,  227. 
Balsams,  493. 
Barium,  235,  239. 

carbonate,  239. 

chlorid,  239. 

cobaltite,  249. 

dioxid,  239. 

hydroxid,  239. 

monoxid,  239. 

nitrate,  239. 

oxids,  239. 

peroxid,  239. 

pyromucate,  509. 

sulfate.  239. 
Baryta,  239. 
Bases,  63,  64. 

acidity  of,  64. 

atomicity  of,  64. 
Bassorin,  321. 

Basylous  elements,  102,  818. 
Battery,  galvanic,  41. 
Beauxite,  245,  247. 
Beer,  290. 
Beeswax,  363. 
Belladonnin,  553,  555. 
Benzamid,  456,  477,  479,  480. 
Benzene,  425,  433,  486,  440,  444,  471,  477, 
484,  495,  501,  502,  504,  510. 

amido,  473. 

amido  derivatives  of,  470,  471,  478. 

azomethane,  483. 

carboxylic  acids,  414. 

halids,  441,  442. 

hexagon, 435. 

homologues  of,  440. 

hydroxvlamin   derivatives  of,  470,  471, 
478. 

imido  derivatives  of,  470. 

nitro,  471. 

nitro  derivatives  of,  470. 

nitrogen  derivatives  of,  470,  471. 

nitroso  derivatives  of,  470,  478. 

sulfochlorid,  380,  469. 
Benzenyl,  456. 

amidin,  456. 

amidoxim,  481. 
Benzhydrol,  503,  504,  606. 
Benzidin,  484,  608. 
Benzil,  504. 
Beuziiie,  276. 
Benzodiazins,  521. 
Benzofurfurane,  539. 
Benzoin,  504. 
Benzol,  440. 
Benzolene,  276. 
Benzometadiazins,  521. 
Benzonitril,  476. 
Benzoparadiazins,  521. 
Benzophenol,  444. 
Benzophenone,  503,  504. 
Benzopyridin,  538. 

bases,  543. 
Benzopyrones,  539. 
Benzopyrrole,  538,  539. 


794 


INDEX 


Benioqninoiie,  462. 
Bensoitbodiasiiu,  621. 
Bensoaol,  448. 
Bensojl,  443,  456,  478. 

•mid,  477. 

chlorid,  298,  311,  323,  324.  369,  38S.  417, 
464,  466,  4e8,  477,  479,  480,  ^7. 

eyanid,  454,  «68. 

diasoimid,  162 

eegonlo,  548,  662,  ii5. 

glyeoeoll,  479. 

bydrid,  468. 

omithin,  480. 

saliein,  468. 

sulfonic  imid,  470. 
Bensyl,  443. 

■eetftte,  468. 

benzene,  439,  iOS. 

eblorid,  443,  508. 

bydmte,  468. 

salfld,  603. 
Berberin.  548. 
Beryl,  245. 
B^ryllinm.  245. 
Betaln,  384,  385. 

aldehyde,  384,  385. 

eblorid,  384. 

bydroeblorid,  885. 

metbylnieotie,  549. 

trimetbyUeelie,  384. 
Betalns,  384. 
BeTeimges.  aleobolle,  290. 
Beaoar  stone,  649. 
Bidipbenyleneetbane,  494. 
Bieberieb  scarlet,  498. 
Biliary  pigments,  634,  687,  640,  641, 642. 

salts.  68«.  639. 
Bilicyanin,  637. 
Bile,  688,  645,  678,  680. 

acids  of,  635,  636. 

bilirabin  in.  637. 

biliverdin  in,  638. 

bladder.  634,  637. 

cholesterol  in,  638.  639,  642. 

composition  of,  G34. 

coloring  matters  of,  634,  637,  640,  641, 
642. 

function  of,  633. 

hepatic.  634,  637. 

iron  in.  641. 

lecithins  in,  635. 

quantity  of,  634. 

salts  of.  635.  640. 

sodium  ^:lycocholatein,  636. 

sodium  taurocholate  in,  636. 

urea  in,  635. 
Bilifuscin,  638. 
Bilihumin,  638. 
Bilineurin,  383. 
Biliprasin,  6.'t8. 
Bilirubin.  604.  636,  640,  641. 
Biliverdin,  636,  637. 
Biamark  brown,  476. 
Bismuth,  148,  209. 

hydroxid.  209. 

nitrate,  210. 

oxids  of,  209. 

pentoxid.  210. 

subcarbonate,  210. 

subnitrate,  210. 

sulfld.  210. 

trichlorid,  210. 


Bismatb  triozid,  806. 
Bismutbates.  209. 
Bi^mathyl,  209. 

earbonate,  210. 

eblorid,  210. 

bydrozid,  210. 

nitrate,  210. 
Biuret,  404, 407.  525. 
Bleaebing  powder,  236. 
Blende,  242. 
Blood,  649,  667. 

alkalinity  of,  667,  676. 

arterin  in,  659. 

earbobydrates  in,  654,  681. 

earbon  diozid  in,  690. 

ebangea  iu,  677. 

chemieal  examination  of  ^  675. 

clot,  649,  667. 

eoagnlation  of,  649.  667. 

eolorinic  substances,  669. 

eorpuseles,  649,  656. 
eompositlon  of,  658. 
stroma  of,  658. 

eleetrieal  eondnetiTity  of,  668,  676. 

freesing  point  of,  658,  676. 

gases  of,  688. 

lakeing  of,  656. 

osmotic  pressure  of,  658. 

plasma,  649. 

reaction  of,  667,  676. 

serum,  649,  650,  653. 
and  baeterial  action,  669. 

specifle  gravity  of,  675. 
Blue  stone,  251. 
Boas'  process,  623. 
Bog  ore,  202. 
Boiling,  29,  32. 

point,  22,  32. 
absolute,  80. 

elevation  of,  31,  32,  68,  69. 
Bone  ash,  237. 

black,  189. 

oil,  517,  543. 
Borax,  187,  219. 
Bordeaux  dyes,  498. 
Borneo  camphor,  488,  491. 
Borneol,  491,  492. 
Boroglycerid,  187. 
Boron,  187. 

'    trioxid,  187. 
Bottcher's  crystals,  387. 
Braunite,  195. 
British  gum,  321. 
Bromacetophenone,  400,  541. 
Bromal.  305. 

hydrate,  305. 
Broroanilins,  475. 
Bromidion,  134. 
Broniids,  134. 
Bromin.  125.  138. 
Bromindene,  496. 
Bromoform,  297. 
Bromol,  448. 
Bromophenols,  448. 
Brucin.  559,  561. 
Butalanin,  414. 
Butaldehyde,  305. 
Butandiol,  305. 
Butane.  273. 
Butene,  273. 
Butone,  273. 
Butter,  763. 


INDEX 


795 


',  adulterations  of,  762,  763. 
fat,  712. 

€bM»dyl,  422. 

eyanid,  423. 

ozid,  422. 
Cadaverin,  886,  418,  581,  617,  758. 
Cadet.  liquid  of,  422. 
Cadmium,  240,  245. 
Caffein,  528,  532,  688,  546. 
Calamine,  242,  244. 
Calcspar,  237. 
Calcium,  235. 

aoetylid,  425. 

earbid,  236.  424. 

earbonate,  237. 

chlorid,  236. 

formate,  300. 

irroup,  235. 

hydrozid,  236. 

hypochlorite,  236. 

oxalate,  238. 

oxid,  235. 

paracasein,  617. 

phosphates,  237. 

plumbite,  205. 

salts,  668,  745. 

sulfate,  237. 

superphosphate,  237. 

urate,  531. 
Calculi,  ammonio-magnesian,  705. 

analvsis  of,  760. 

biliary.  636,  638,  642. 

cystin,  759. 

fusible,  705,  759. 

intestinal,  649. 

mulberry,  238,  731,759. 

oxalate,  759. 

phosphatic,  705,  759. 

salivary,  608. 

urate,  759. 

uric  acid,  759. 

urinary,  697,  705,  786. 

xanthin,  759. 
Calomel,  256, 
Calorie,  22. 
Camplians,  487,  488. 
Camphene.  488,  491,  492. 
Camphol,  491. 
Camphor,  492. 

artificial,  488. 

Borneo,  488,  491. 

Japan,  492. 

laurel,  492. 

momobromo,  492. 
Camphors,  487. 
Campobello,  yellow,  498. 
Cane  suf^ar,  316. 
Caramel,  317. 
Carbami<l.  402,  403. 
Carbaniins,  394. 
Carbamyl  chlorid,  402. 
Carbanil,  orthoxv,  475. 
Carbaaole.  501,  538,  648. 
CarbidM,  425. 
Carbimid,  396,  402,  408. 
Carbinamins,  382. 
Carbinol.  285,  286. 

butyl,  293. 

diethvl,  293. 

diphenyl,  503,  504. 

diphenyltoluyl,  503. 


Carbinol,  sethyl,  291. 

ethyldimethyl,  294. 

ethylmethyl,  292. 

isobutyl,  293. 

isopropyl,  292. 

methyl.  287. 

methylisopropyl,  294. 

methylpropyl,  293. 

phenyldimethyl,  453. 

phenylmethyl,  453. 

propyl,  292. 

trlmethyl,  292. 

tri phenyl,  503,  504. 
Carbocyclic  compounds,  272,  433,  484. 
Carbodiimids,  474. 
Carbohydrates,  809,  509,  642,  643. 

of  blood  serum,  654. 

tests  for,  323. 
Carbolates,  446. 
Carbolic  oil   440. 
Carbon,  188. 

compounds  of  262. 

dichlorid,  280. 

dioxid,  363.  354,  690. 
hieraog^lobin,  663. 

diitulfid,  275,  373,  874,  380,  397. 

group  188. 

metallic,  189. 

monoxid,  275,  362. 
haemoglobin,  354,  662. 

oxids  of,  352. 

oxysulfld,  375,  397. 

tetrabroraid,  280. 

tetrachlorid,  275,  280,  458. 

trichlorid,  280,  281,  364. 
Carbonic  oxid,  352. 
Carbonous  oxid,  352. 
Carbonyl,  270,  299. 

chlorid,  363,  402,  403,  407,  408,  504. 

diurea.  406,  408. 
Carborundum,  191. 
Carbostyril,  544. 
Carbotriamin,  388. 
Carboxim,  409,  410. 
Carboxyl,  270,  288.  328,  370. 
Carbylamins,  380,  394. 
Carbyloxim,  396. 
Carnallite.  222. 
Camin,  532,  636,  724. 
Carvacrol,  447,  491,  492. 
Carvol,  447,  491. 
Carvone,  491. 
Carvoxims,  492. 
Casein,  582,  586,  617,  633,  763. 
Caneinogen,  764. 
Caseinoses,  613. 
Cassel  yellow,  206. 
Cassiterite,  212. 
CaUlysers,  108. 
Catechol,  729. 
Cathode,  41. 
Cations,  44.  72. 
Celestine,  2.38. 
Cell  globulins,  582,  653,  666. 
Cellulin,  322. 
Cellulase,  605. 
Celluloid,  323. 
Cellulose,  322,  643. 

nitro.  323. 

starch,  321. 
Celsius'  scale.  22. 
Centigrad  scale,  22. 


796 


INDEX 


Cerebrin,  315,  6M. 
CerebroM,  315. 
Cerium,  56, 102, 108. 
Gerase,  207. 
Ceryl  oerotate,  363. 

bydrcndd,  294. 
Cesiiim,  215. 
Getin,  363. 
Cetyl  bydzozld,  294. 

palmitttte,  363. 
C.  G.  S.  system,  7. 
Cbalk,  235,  237. 

precipitated,  238. 
Cbaracteriiing  groups,  270. 
Cbarcoal,  189. 

animal,  189. 
Cbareot's  crystals,  387. 
CbaTicol,  460. 
Chemical  aetlTity,  75. 

ai&nity,  86. 

energy,  86. 

equilibrium,  87. 

force,  86. 

terms,  ortboffn^hy  of,  771* 
Oiemism,  86. 
Chemistry,  2. 

general,  1. 

inorganic,  107. 

mineral  107. 

organic,  262. 

physical,  3. 

physiological,  574. 
ChinoTOse,  311. 
Chitin.  387,  097. 
Chitosamin,  387. 
Chitose,  388. 
Chloraeetone,  540. 
Chloraeetyl  alanin,  416. 

glycin,  416« 


glycylglycin,  416. 
Loral,  80S,  330. 


Chloral, 

alcholate,  303,  304. 

butyric,  306. 

hydrate,  269,  278,  804,  401. 
Chloralamid,  401. 
Chloralid,  304. 
Chloralimid,  401. 
Chloralum,  247. 
Chloranilins,  447,  475. 
Chloraurates,  193,  381. 
Chlorhydrar^rates,  255,  258. 
Chloride  of  lime,  236. 
Chloridion,  77,  132. 
Chlorids,  131. 
Chlorin,  125,  127,  133. 

group,  125. 

moDoxid,  133. 

perozid,  133. 

tetroxid,  133. 
Chlorindones.  496. 
Chlorobenzenes,  437,  442. 
Chlorobromobenzenes,  438. 
Chlorocarbon,  280. 
Chloroform,   278,  304,  380,  391,  394,   401, 

424,  476,  502. 
Chloromercurates,  255,  258. 
Chloromethyl,  278. 
Chlorophenols,  447. 
Chlorophyll,  301,  598. 
Chloroplatinates.  214,  381. 
Chloropurins,  532,  534. 
Chlorozone,  220. 


Cholesterol,  584, 586, 684, 6S8, 689, 611, 664» 

666,680. 
Choletelin,  637. 

Cholln,  367,  88S,  886,  886,  681,  644. 
Chondroitin,  504. 
Chondromncoid,  504. 
Chondrosin,  504. 
Chromates,  195. 
Chrome  yellow,  206. 
Chromium,  194. 

green,  195. 

ozids  of,  194. 
Chrysarobin,  500. 
Chrysasol,  499. 
Chrysene,  493,  494,  496. 
Chyle,  692,  693. 
Chyluria,  642. 
Chyme,  619,  628,  646. 
Chymosin,  617. 
Chymosinogen,  617. 
Cider,  291. 
Cinchona  aUcaloids,  547,  OOf.  558* 

red,  556. 
Clnehonidin,  519,  556,  668. 
Cinehonin,  519,  543,  556,  iiS,  569. 
Cinene,  487. 
Cineol,  487,  490. 
Cinnabar,  254. 
Cinnamene,  44S,  496. 
Cinnamyl  cocain,  548,  652. 
Circuit,  electric,  40. 
Cisterpin,  490. 
atroneUal,  428. 
Clnssiflcation  of  alkaloids,  548. 

of  aromatic  compounds,  489. 

of  carboeyclio  compounds,  484,  489. 

of  heterocyclic  compounds,  507,  508* 

of  organic  compounds,  271. 

of  proteins,  582. 
Clay,  245,  248. 

ironstone,  202. 
Closed  chain  compounds,  433. 
Clot,  649. 
Clupein,  589. 

Coagulated  albumins,  583. 
Coagulating  albumins,  582,  585. 
Coagulation,  575,  667. 

temperature,  576. 
Coal,  188. 

tar,  440. 
Cobalt,  249. 
Cobalticyanids,  399. 
Cocain,  548,  552,  §56. 
Codein,  562.  564,  565,  566,  567. 
Coefficient,  isotonic,  657. 

of  distribution,  28. 
Coerulignone,  502. 
Cohesion,  13. 
Coke,  189. 
Colchicin,  569. 
Colcothar,  198. 
Collagen,  583,  596,  619. 
Collidins,  518. 
Colloids,  18,  575. 
Colophany,  488. 
Columbium,  55,  101,  103. 
ComblnatioDS,  62. 
Combustion,  111. 

supporters  of.  111. 
Complement.  672,  675. 
Components,  96. 
Composition,  84. 


INDEX 


797 


Compound  ammonias,  377. 
Compounds,  47,  48,  &4. 
Compoundit,  acyclic,  271,  273. 

aliphatic,  271,  273. 

aromatic,  272,  439. 

earbocyclic,  272.  433,  484. 

elosed  chain,  272,  433. 

cyclic,  272,  433. 

fatty,  271.  278. 

heptacarbocyelic,  434. 

heterocyclic,  272,  433. 

hexacarbocyclic,  434,  435. 

monobenzenic,  439,  440. 

open  chain,  271. 

organic,  262,  271. 

pentacarbocyclic,  434. 

saturated,  268,  273. 

tetracarbocyclic,  434. 

tricarbocyelic,  434. 

unsaturated,  269. 
CoDchiolin,  597. 
Concentration,  2,  18,  64. 
Condensation,  21,  32,  801,  302,  361. 
Condensed  earbocyclic  compounds,  493. 

heterocyclic  compounds,  537. 

nuclei,  493. 
Condensing  agents,  301. 
Conductance,  45. 
Conductivity,  equivalent,  74. 

molecular,  74. 
Conductors,  39. 
Congelation,  28. 
Conglutin,  584. 
Congo  red,  502. 

yellow,  502. 
Conhydrin,  548,  549. 
Coniferin,  454. 
Conicein,  548. 

Coniln,  414,  518,  519,  548,  649. 
Conjugate  glucuronates,  684,  750. 
Consecutive  positions,  437. 
Constitution,  84,  264,  268. 
Contact  action,  349. 

agent,  108. 
Conyrin,  518. 
Copper,  250,  634. 

aceUtes,  252. 

acetylid,  423,  425. 

ammonio-sulfate,  252t 

carbonates,  252. 

chlorids,  251. 

glycolaraate,  414. 

group,  250. 

hydroxids,  251. 

oxids,  250. 

sulflds,  251. 
Copperas,  200. 
Coprolites,  237. 
Corallin,  444,  450. 
CoridiuR,  519. 
Corrosive  sublimate,  257. 
Corrosives,  132. 
Corundum,  246. 
Cosmolin,  277. 
Cotarnin,  564,  566. 
Coulomb,  44. 
Coumarin,  466,  689. 
Coumarins,  539. 
Coumarone,  539. 
Cream.  762. 
Creamoraeter,  762. 
Creasol,  446. 


Creosote,  446. 

oil   440. 
Creatin,  889,  403,  414,  719,  720. 
Creatinin,  389,  890,  709,  710,  712,  718. 
Creolin,  446. 
Cresol,  444.  581. 
Cresols,  446. 
Cresylols,  446. 
CrisUllin,  473. 
Crotin,  573. 

Croton  chloral  hydrate,  306. 
Crusocreatinin,  390. 
Cryolyte,  126,  220,  245. 
Crystal  violet,  506. 
CrysUUization,  13. 
CrysUlloids,  18. 
Cupric  acetate,  252. 

arsenite,  252 

carbonate.  262. 

ehlorid,  251. 

hydroxid,  251. 

nitrate,  251. 

oxid,  250. 

sulfate,  251. 

sulfld,  251. 
Cuprous  chlorid,  261. 

oxid,  250. 

sulfld,  251. 
Curarin,  561. 
Curd,  617. 
Current  density,  43. 
normal,  45. 

divided,  43. 

strength,  41,  44. 
Curtlus'  base,  416,  630. 
Cuzcohygrin,  548. 
Cyamelid,  396,  402. 
Cyanacetamid,  395. 

Cyanamid,  388,  389,  898,  406,  414,  418,  421. 
Cyanamids,  substituted,  398. 
Cyanhydrins,  391,  897. 
Cyanic  esters,  328. 
Cyanidln,  536,  537. 
Cyanids,  391.  393. 

alkyl,  277. 

compound,  398. 

double,  398. 

metallic,  398. 

simple,  398. 
Cyanobenzene,  476,  482. 
Cyanoform,  395. 
Cyanogen,  39. 

chlorids,  898,  398,  402,  414. 

compounds,  391. 

hydrid,  391. 

iodid,  388. 

sulfhydrate,  396. 
Cyanophenin,  537. 
Cyclic  compounds,  272,  433. 
Cyclodlolefln,  434. 
Cyclohepatri^ne,  552. 
Cycloheptene,  552. 
CyclohexadiSne,  486. 
Cyclohexane,  486. 
Cyelohexene,  434,  486. 
Cyeloparafflns,  434. 
Cyclopterin,  589. 
Cyclotriolefln,  434. 
Cymene,  442,  447,  492. 
Cymogene,  276. 
Cymylic  phenol,  447. 
CysteTn,  421,  580,  581. 


798 


INDEX 


Cy8tin,  374,  416,  421,  579,  680,  581,  595,  596, 

617,  640,  757,  759. 
Cvstinuria,  422,  757,  758. 
Cytolysins,  657,  671,  675. 
Cytolysis,  656. 
Cytosin,  626,  593. 
Cytotoxlns,  657,  670,  671. 

Dahlia,  506. 
l>umbcjniU\  490. 
DiimbtJ??!?,  490. 
Dtt^phnt^tiD   466. 
Daplinin,  466. 
DeamidatioD,  413. 
DeenhydroquiDoliDt  544. 
Dccotajit>f^it!otjs,  62. 

douf>|e,  G2. 

primary,  63. 
Degrees  of  freedom ,  94. 
Deh  y  d  roni  orp  bin,  563. 
Dt'liquescenee,  27. 
DeDHturiEed  proteitii,  575. 
Density,  9»  10. 

absolute,  9. 

critical,  30. 

current,  43. 

normal  electric,  45. 

relative,  10. 

D**03ti*lEit.M>lK    I  its. 

Deoivjstrvchiiiiii.   'iSO. 

DeiiieTOiJlmriio^^t'^,  614,  616,  618,  629. 

Deutero^iikfltHLise,  597. 

Dextrin,  287,  321. 

DtxrdnH,  321. 

Di'Xtroj^yroua  Bubstances,  38. 

Deitroset  314. 

Dliil>et*^fl,  744,  745.  746,  748,  763. 

pancreotir,  746. 

plllorid^iii,  744. 
Diabetie  Nui^ar,  314. 
Di»ct?taniid.  400. 
Diaci^tiii   296. 
Diaci'Tonamin   409. 
Dincttylt^iie  serien^  273. 
l>iH('Hvlc4bvl(?nKdhitijio,  514. 
Dinci'tyliufifpljiii.  562. 
J>i^iriplp*'rftE[n,  416*  522. 
BiacipipiraKins.  522, 
Diftcl'i\  liirelfl^,  407. 
Dlaldehyilt  ^  308,  335. 
Dialysis,  18. 
Diamid,  152.  484. 

aspartic,  407. 
DiaTiii<lodiphenol,  439. 
Dianiidoparafflns,  387. 
Diamids,  :{99,  401. 

dialkyl.  :m). 

Mumimlky    379. 

priiiinry    403. 
Dianijn   d^iWel ylethylene,  385,  514. 

dtetliyJen     52;^' 

diiiieTlivlp  <>tiv1enp,  520. 

diphtnvldiethyiene,  522. 

ftln  l^nt^.  3S5. 

h    XJiTiJrtbvl*  l)f^,  386. 

pciiTLi [hvlfiii?,  380,387,  519. 

Terniirt-  nj>  l^iif.',  1185  3SiK 
letrRnieTbylnifiThylene,  380. 
trietiivlf  tji*,  385. 
trim  tlivleiie*  anS   ^M. 
Diamins,  :m,  :«Ni.  371,  ^78,  380,  382,  386, 
386,  395,  40ii,  581. 


Diamond,  188. 
Diti.^tiise,  287,  B19,  605. 

piincreiitlc,  627,  631,  643. 
DlaHtttiie  action,  COS. 
Din^ini^t  :'i20. 
DltiKu  aniidobenz&ne,  482,  484. 

»mido  ci>mpi>und$,  481,  482,  483,  48l» 

benzene,  48 J. 
chlorid,  481,  482,  484,  501. 
cyifciiid,4S2 

^>>m|KMiTi«U,  380,  444,  471,  481,  481^418 

dyes,  484. 

group,  481. 

oxy  c^ompotind«»  482. 

paraffins,  376^ 

reaction,  479. 
Diazoles,  511,512. 
Diazotizing,  482. 
DIbentupy rones,  53S. 
D  i  be  n  z  u  |i  vrro  k* ,  543 . 
DibenzoTl,  504. 
Dlbeuzyl,  502. 
Dibrumin ethyl  bromiii,  280. 
Dlbroniubeiiaiene!*,  43S. 
DtbroniopKnifnu*^,  434. 
Dibronio  propyl  in,  427. 
Dlbutyldiiifljptpi^rartii,  622. 
DibutvriLhlh}.  ."mO. 
DicHcodyt.  r^>. 
Dkbioronjiin,  47.7. 
Dicblori*tbaiR*,  299. 
DicblorHhyltFejiBen^,  463. 
Dichlorhydrin,  426. 
Di  r  ii  lorm  ptl  mn  e .  278 . 
DicliiornK'Eljyl  rtilorid,  278» 
Diebkironapthftleti^,  496. 
DklilorprijpRiie,  299. 
DicyaiiidH,  33.),  39.^. 
Dicvitnoijeii,  a95,  396. 

DietJiylacetamld,  399,  "; 

DietbvlbimKi-ne»H  441. 
Diethyl^HdHnnl,  293. 
Dii'thylon-iluMniri,  522. 
D  it  t  h  y  I  Jii  id  a  1 1  y  I  u  rtfl ,  526. 
Diflfusictn  of  Rftses,  20* 

ot  liquids,  m. 
DlflutirdifibenvL  502, 
Digi^Ktimi,  599,  606. 

RuUih  rie.  006. 
Diglyceri'd'*,  296. 
Ditfiyt'yiglycin,  416, 
Dig^itHliripsin,  4fi7. 
Digital  i!^  dueos^id^,  467. 
Digital] n,  4B7. 
DisitaloRB.  407. 
I)iifiiout*iiiij,  4<>7. 
DfLntmirfn,  4^7. 
Di.8:itonin,  467. 
Digitoxin,  467. 
Dihydrobenzenes,  434,  486. 
Dihydrocymenes,  487. 
DihydrnfurfurEine.  FiO!>, 
Diiiydni^rlyoxftlina   51 4. 
Dil)V«li''pvrH^ij](*  ^\2 
Diliydrr^pyriditis.  fit 9,  523. 
DibyHtitpyrrnli?,  ,^]1. 
Dibyilnnjiiinnlins,  ."j44. 
1  >  i  U  yd  ro  -*  [  ry  chno  5 1  ti ,  560. 
Dill  vd  rot  rfipnn,  652. 
Diimh-v.  -i-.T^  ?S2, 

Diindoxvl,  542. 
Diiodom'ethvl  iodid,  280. 


INDEX 


799 


Diiodothymol,  447. 
Diketones,  307,  308,  499. 
Diketopurin,  532. 
Diketotetrahydroglyoxalin,  515. 
Diketotetrahydropyrimidin,  523. 
Dimetadioxytoluene,  449. 
Dimethozyisoquinolin,  566. 
Dimethyl  acetone  hydrazone,  382. 

amidobenEene,  621,  622. 

amin,  381. 

anilin,  302,  603,  506. 

aMthracene,  497. 

arsin,  422. 

benzenes,  441,  442. 

•arbinamin,  382. 

ethylbenzenes,  441. 
Diraethylia,  381. 
Dimethyl  indoles,  540. 

ketone,'  307. 

malonylurea,  526. 

•xamid,  379. 

oxyphthalid,  462. 

phenols,  446. 

phenylenediamin,  520. 

pyrazole,  512. 

pyridins,  518. 

uracil,  524. 

xanthins,  533. 
Bimorphism,  17. 
Dinitranilins,  475. 
Dinitrobenzenes,  440,  471. 
Dinitrocresols,  472. 
Dinitronapthola,  498. 
Dinitrophenols,  472. 
Dinitro.soresorcinol,  473. 
Dioleflns,  273,  425. 
Diol«,  294. 
Dionin,  562. 
Dioses,  309,  310. 
Dioxindole,  478,  541. 
Dioxyacetone,  296,  310. 
Dioxyanthracenes,  499. 
Dioxyanthraquinone,  500. 
Dioxycuumarin,  467. 
DioxymethylanthraquinoDOi  500. 
Dioxypurin,  532. 
Dioxyuracil,  529. 
Dipentene,  487,  488,  491. 

nitrosochlorid,  487. 
DipeptidH,  412,  416. 
Diphenyl,  496,  601. 

acetylene,  502,  503. 

benzene,  501. 

diacetylene,  503. 

diethylenediamin,  522. 
Diphenylene  diketone,  496. 

diphenylethylene,  494. 

iniid,  538. 

ketone,  499. 

methane,  494. 

sumd,  501. 
Diphenyl  ethanes,  502. 

ethylene,  502,  503. 

hy<lrazin,  484. 

iraid,  543. 

methane,  439,  494,  60S. 

olefin H,  502. 

oxid,  464,  501. 

paraffins,  502. 

phthalid.  504. 

pyridins,  545. 
Dipiperidein,  519. 


Dlpyridyl,  646. 
Disaoeharids,  309,  tl6,  643. 
Disaoryl,  427. 

Disdiazoamido  oompotmds,  482. 
Displacement,  87. 
Dissociation,  70,  90,  116. 

coei&cient  of,  73. 

constant,  75. 

degree  of,  73. 
Distillation,  32. 

fractional,  51. 
Dlsulflds,  371. 
Dithioketones,  373. 
Diareids,  406. 
Divisibility,  3. 
Dolomite,  240,  241. 
Dulcin,  298. 
DulciUn,  298. 
Dulcite,  298,  315. 
Dulcitol,  298,  346. 
Dulcose,  298. 
Dutch  liquid,  364,  424. 
Dynamite,  365. 
Dyne,  7. 
Dyslysin,  635,  640. 

Ebullition,  29. 

Ecbolin,  569. 

Ecgonin,  519,  548,  552.  553,  •••• 

Edestin,  587. 

Efflorescence,  17. 

Eggs,  white  of,  684. 

yolk  of,  586. 
Ehrlich's  diazo  reaction,  743. 

theory,  672. 
Elastin,  583,  .596,  619. 
Elastoses,  619. 
Elayl,  423. 

chlorid,  364. 
Electric  circuit,  40. 

conductance,  41. 

conductivity,  41. 
of  blood,  658,  676. 
of  urine,  699. 

current,  40. 

quantity,  41,  44. 

resistance,  41. 

resistivity,  41. 

units,  44. 
Electricity,  39. 

galvanic,  40. 

negative,  39. 

positive,  39. 

resinous,  39. 

vitreous,  39. 
Electrodes,  40. 

Electrochemical  equivalent,  71* 
Electrolysis,  43,  62. 
Electrolyte,  43. 
Electrolytic  dissociation,  70. 
Electromotive  force,  41. 
Electronegative,  62. 
Electropositive,  62. 
Elements,  47,  55. 

acidulous,  101,  ISi. 

amphoteric,  101,  192. 

baf^ylouH,  102,  21i. 

classification  of,  100,  103. 

electronegative,  62,  101. 

electropositive,  62,  102. 

typical,  101,  106. 
Eleoptenes,  488. 


800 


INDEX 


Eleutriation,  238. 
Emerald,  245. 

green,  195. 
Emery,  246. 
Emetin,  570. 
Emodin,  500. 

EmuUin,  465,  466,  468,  606. 
Emulsion,  366. 
Eneriary,  8,  598. 

chemical,  86. 

dissipation  of,  9. 

kinetic,  8. 

potential,  9. 
Enol  form,  537. 
Enterokinase,  626,  627. 
Enzymes,  599,  603. 

amylolytic,  605. 

autolytic,  631. 

classification  of,  605. 

coagulating,  606. 

glucosid -splitting,  606. 

glycolytic,  606. 

lipolytic,  605. 

mineral,  604. 

of  plasma,  654. 

proteolytic,  581,  605. 

salivary,  607. 
Eosin,  451. 
Epichlorhydrin,  351. 
Epiguanin,  532,  686. 
Episarkin,  532,  536. 
Epsom  salt,  241. 
Equations,  60. 
Equilibrium,  30. 

apparent,  88. 

chemical,  87. 

heterogeneous,  88,  93. 

homogeneous,  88. 

metastable,  95. 

nitrogenous,  707. 

real,  88. 
Equivalent,  64. 

chemical,  60. 

conductivity,  74. 

electrochemical,  71. 

Joule's,  23. 

osmotic,  18. 
Erbium,  55,  103. 
Erepsin,  632. 

pancreas,  630. 
Ergotin,  569. 
Erythrin,  297. 
Erythrite,  297. 
Erythrodextrin,  322,  643. 
Ervthroplucin,  297. 
Erythrol,  297,  345,  509. 

triacetyl,  367. 

tettftnitro,  297,  367. 
Erythrolysis,  656. 
Erythrose,  310. 
Eserin,  570. 
Essence  of  Mirbane,  471. 

of  turpentine,  488. 
Essences,  .%6,  486,  488. 
Ester,  acetoacetic,  360.  513,  524,  529,  719. 

alkaloids,  r)47,  552,  553. 

aniidoacetoacetic,  420. 

benzoylacetlc,  525. 

cyanoucetic,  534,  535. 

cyanomalonic,  395. 

cyanopropylmalonic,  418. 

diethyloxamic,  403. 


Ester,  dimethylozamie,  379. 

formic,  420. 

formylhippuric,  420. 

glycerolformic,  426. 

glycocoll,  522. 

hippuric,  420. 

malonamic,  411. 

malonic,  861,  482,  527. 

methenyltricarbozylio,  336. 

methylenemalonic,  42M). 

monobenzoylserin,  420. 

nitroacetic,  412. 

phenylhydrazoneacetic,  513. 

sodium  formylacetie,  524. 

sodinmpropylformic,  524. 

sulfates,  470,  646,  647,  684,  702,  728. 
Esters,  282,  284,  286,  294,  348,  8i6,  410. 

acetoacetic,  360,  361,  362. 

acid,  358. 

alcohol,  358. 

aromatic,  458. 

benzoic,  298. 

beta-ketonic,  347,  860. 

carbonic,  402. 

cyanic,  328. 

cyclic,  368. 

dioxjrmalonic,  347. 

haloid,  277,  286,  294,  359,  363,  393. 

hydrocyanic,  393. 

hyposulfurous,  360. 

isocyanic,  379,  397,  406. 

Isothiocyanic,  397. 

ketonic,  347,  860,  361,  513. 

malonic,  361,  362. 

menthyl,  490. 

nitric,  379. 

nitrous,  376, 

of  amidoacids,  412. 

of  carbonic  acid,  402. 

of  cholesterol,  6381 

of  dihydric  alcohols,  363. 

of  glycerol,  364,  365. 

of  glycols,  294,  363. 

of  ketone  acids,  347,  860,  513,  523. 

of  monocarboxylic  acids,  379. 

of  mouohydric  alcohols,  358. 

of  oxyacids,  368. 

of  polyhydric  alcohols,  367. 

of  trihydric  alcohols,  364. 

oxymalonic,  347. 

phenol,  446. 

phenyl,  444,  446,  464. 

thiophosphoric,  371. 

sulfurous,  360. 
Ethane,  380,  423,  425. 
Ethene,  423,  425. 

chlorhydrin,  295. 

compounds,  424. 

glycol,  295. 

bomologues  of,  424. 
Ethenylamidozim,  388. 
Ether,  acetic,  360. 

allylic,  421. 

diethyleneglycol,  350.  ,. 

dimethylpyrocatechuic,  449. 

ethylic,  464. 

glycerol,  351. 

glycoldiethyl,  350. 

glycolethyl,  350. 

hydriodic,  281. 

hvdrobromic,  281. 

hydrochloric,  281. 


INDEX 


801 


Ether,  methylphenyl,  444,  464. 

moDomethylpyrocatechaic,  448. 

muriatic,  281. 

nitric,  359. 

nitrous,  359. 

petroleum,  276. 

phenyl,  464. 

propargylethyl,  431. 

pyroacetic,  307. 

pyrocatecholmethylene,  450. 

sulfuric,  349,  359. 
Ethers,  348. 

beuzenic,  443. 

compound,  348,  868. 

cyclic,  350. 

glycerol,  350. 

glycol,  350. 

haloid,  277. 

mixed,  282,  348. 

phenyl,  446. 

simple,  282,  348. 
Ethidenechlorid,  299,  424,  425. 

compounds,  424. 

diethylsulfone,  373. 

hydroxylamin,  409. 
Ethine,  424. 
Ethol,  363. 
Ethyl  acetamid,  401. 

acetate,  860,  361,  400,  401. 

acetoacetate,  360. 

acetylsodacetate,  361. 

amidoacetate,  414. 

amin,  381,  394,  401. 

benzene.  441,  448. 

borate,  187. 

bromid,  281,  423,  424. 

carbinol,  291. 

chlorid,  281.303,364. 

cyan  id,  394. 

dimethvlcarbinol,  294. 

hydroxld.  287. 

iodid,  281.  424,  472. 

isocyanate,  397. 

malonate,  361. 

mercaptan,  372. 

mercaptoketopyrimidins,  524,  525. 

mercaptol,  374. 

methylcarbinol,  292. 

methylpyridin,  559. 

morphin.  562. 

nitrate.  359. 

nitrite,  359. 

orthocarbonate,  388. 

oxalate,  403, 

oxid,  349. 

phenols,  447. 

pyridins.  518. 

pseudourea,  524. 

sulfates,  359,  360. 

sulfhvdrate,  372. 

sulfld'.  579,  580. 

sulfites.  360. 

thallin,  544. 

urethan,  402. 
Ethylates,  289. 
Ethylene.  364,  423. 

benzene,  442. 

bichlorid,  364. 

bromid,  295,  424,  522. 

chlorhydrin.  350,  868,  383. 

chlorid,  364,  424. 

compounds,  424. 

51 


Ethylene,  cyanhydrin,  342. 

cyanid,  385. 

diamin,  385. 

dlammonium  chlorid,  514. 

haiids,  423. 

hydroxamin,  409. 

imid,  508. 

imin,  387. 

monochlorid,  314. 

naphthalene,  495. 

oxid,  350. 

sulfld,  508. 
Ethylidene  compounds,  424« 
Eucalypteol,  490. 
Eucalyptol,  490. 
Eugenol,  450. 
Euglobulin,  652. 
Euphorin,  402. 
Evaporation,  49. 
Exalgin,  476. 
Exudates,  693. 

Faeces,  546,  647. 
Fahrenheit's  scale,  22. 
Faraday,  72.  ^ 

Fats,  366,  633,  644,  645,  654,  693. 

phosphorized,  367. 
Feldspar,  245,  248. 
Ferments.  699,  603. 
Fermentation,  acetous,  601,  643. . 

alcoholic,  600,  643. 

ammoniacai,  601. 

butylic,  601. 

butyric,  331,601,643. 

lactic,  298,  601   643. 

mixed,  601. 

mucic,  298. 
Fermentations,  bacterial,  601. 
Ferrates,  199. 
Ferric  acetates,  202. 

bromid,  200. 

chlorid,  200. 

citrate,  202. 

ferrocyanid,  203. 

hydrates,  198. 

iodid,  200. 

nitrates,  201. 

oxid,  198. 

pyrophosphate,  201. 

sulfates,  200,  201. 

snlfid,  199. 

tartrate,  202. 
Ferrocyanids,  399. 
Ferrous  acetate.  201. 

bicarbonate,  202. 

bromid,  200. 

carbonate,  202. 

chlorid,  199. 

ferricyanid,  203. 

hydrates,  198. 

iodid,  200. 

lactate,  202. 

nitrate,  201. 

oxalate,  202. 

oxid,  198. 

phosphates,  201. 

sulfate.  200. 

sulfld,  199. 

tartrate,  202. 
Fibrin,  661,  668. 

ferment,  652. 
Fibrinogen,  582,  585,  661,  668,  669,  692. 


802 


INDEX 


FibrinoflrlobnliB,  S8S,  66i,  MS,  eW. 

FibrinoplMtie  sabBtaiieA,  662. 

Pibrinoses,  613. 

Fibroin,  420,  688,  Q97. 

Fire-damp,  275. 

FlaTuiUin.  475. 

Fluorene,  493,  494,  497,  480,  601,  602. 

ketone,  499. 
Flaoresoein,  449,  4il. 
Flaorin,  126,  126. 
Fluor  spur,  126. 
Foot-pounds,  8. 
Foree,  2. 

ohemieal,  86. 

eleotromotilTe,  41. 
Formaldehyde,  800  (see  Aldebydo,  fonnle). 
Formaline,  301. 
Formals,  302,  806. 
Formamid,  400. 
Formin,  409. 

FormonltrU,  329,  S91,  898. 
Formose,  301,  814. 
Formozim,  410. 
Formuin,  60. 

algebraic,  264. 

empirical,  84* 

general,  264. 

graphic,  86,  268. 

rational,  85.  * 

typical,  85. 
Formyl  bromid,  280. 

chlorid,  278. 

hydrid,  dOO. 

iodid,  280. 
Fractional  distUlatloii,  61. 
Fraunhofer's  lines,  36. 
Freesing  point,  21,  68. 

of  blood,  668,  676. 

of  urine,  698. 
Fmctosamin,  485. 
Fructose,  311,  816,  485,  681. 
Fruit  sugar,  315. 
Fuchsin,  506. 
Fucose,  311. 
Furane,  517. 
Furazoles,  511. 
Furfurane,  507,  508,  609. 
Furfurole,  310,  323,  609. 
Furole,  509. 
Furomouazoles,  512. 
Fusel  oil,  291,  292. 
Fusing  point,  26. 
Fusion,  26. 

heat  of,  26. 

Gadinin,  375. 
Gadolinium,  55,  102,  103. 
Galactose,  311,  816,  319. 
Galena,  204,  208. 
Gallein,  450. 
Gallisin,  314,  819. 
Gallium.  55,  102,  103,  245. 
Galvanic  battery,  40. 

cell.  40. 

circuit,  40. 
Garnet,  245. 
Gas,  ideal,  20. 

tar.  440. 
Gases,  19,  29. 

ab«;orption  of,  21. 

diffusion  of,  20. 

effusion  of,  20. 


Chtses,  ezpanslmi  of,  t8« 
general  law  of,  24. 
kinetic  theory  of,  86. 
mixtures  of,  20,  49. 
Qasolene,  276. 
Gastric  digestion,  606. 
juice,  608,  609. 

abnormal  Tariattons  of,  609. 

acetic  acid  in,  619. 

acetone  in,  620. 

acid  of,  6W. 

action  on  profeeins,  612. 

anachlorhydria  ii^  619. 

analysis  of,  620. 

arsenic  in,  620. 

bUe  in,  620. 

butyric  acid  in,  600,  629,  624. 

fermentation,  effect  on,  609. 

free  acid  of,  609,  620. 

hnmatin  in,  620. 

hydrochloric  acid  In,  609,  620,  621. 
effeetiTe,  628. 

hyperehlorhydria  of,  619. 

hypochlorhydria  of,  619. 

lactic  acid  in,  620,  628. 

morphin  in,  620. 

native  albumins  in,  624. 

organic  acids  in,  609,  620.  628,  684. 

pepsin  in,  610,  624. 

pepsinogen  in,  610,  624. 

pepsohydroehloric  acid  in,  611. 

peptones  in,  684. 

primary  albumosea  in,  684. 

products  of  digestion  in,  684. 

protein  hydrochloric  sold  l&t  682,  688. 

seimm  albumin  in,  624. 

syntonin  in,  624. 

total  aciditj  of,  620. 

urea  in,  620. 
mucus,  608. 
GhMtrosteapsin,  619. 
Gelatin,  580,  596,  619,  628. 
explosive,  323. 
peptones,  596. 
sugar,  413. 
Gelatinoses,  612. 
Gelatoses,  596,  619. 
Geneva  commission.  271. 
Geraniol,  427,  428. 
Germanium,  55,  102,  103. 
Glass  of  antimony,  185. 

soluble,  219. 
Glauber's  salt,  218. 
Gliadin,  587. 

Globin,  522,  588,  630,  660. 
GlobulinoHes,  613. 
Globulins,  502,  688. 
Glonoin,  .364. 
Glucase,  655. 
Glucinium,  55,  103. 
Glucoalbumose,  613,  614,  615,  618. 
Gluconolactone,  343. 
Glucononitril.  343. 
Glucosamin,  487,  581,  594. 
Glucosamins,  ,387. 

Glucose,  287,  311,  314,  368,  465,  485,  644, 
654,  679,  680,  744,  745,  747.  749,  750. 
(liacetic,  368. 
tetracetic,  368. 
triacetic,  368. 
Glucoses,  311. 
Glucosids,  311,  314,  368,  464,  465. 


INDEX 


803 


Glucososazone,  315,  388,  489. 
Glucosyl  phenate,  368,  465. 
Glucovanillin,  466. 
(ilucaronates,  646. 
GIutamiD,  420. 
Gluten,  587. 

casein,  587. 

fibrin,  587. 

protein,  582,  586. 
Glutenin,  587. 
Glutokyrin,  629. 
Glycerids,  296,  364. 
Glycerin,  339. 
Glycerol,  287,  295,  896,  426,  427,  668. 

aldehyde,  299,  310. 

halohydrin9,  364. 

ketone,  299,  310. 

trinitrate,  364. 
Glycerols,  295. 
Glycid.  351. 
Glycin,  413. 
Glycogen,  319.  881,  643,  654,  679,  680,  681, 

682.  745. 
Glycocoll,  814,  479,  529,  530,  580,  596,  606, 
614,  630,  634,  636,  639,  640,  680,  685, 
724,  756,  763  (see  acid,  amldoacetio). 

trimethyl,  384. 
Glycocolls,  412. 
Glycol  cblorhvdrins,  364. 

etheue,  2^6,  424. 

ethylene,  295. 

halobydrinA,  313. 

methene,  294. 

propyl,  337. 

toluylene,  504. 
GlycoUid,  412. 
Glycols,  294,  3^,  364. 

ethers  of,  299,  310. 
Glycolyl  aldehyde,  299,  310. 

diurea,  414,  616. 

urea,  414,  616. 
Glycoproteids,  .387.  583,  59i. 
Glycosuria,  467,  625,  682,  683,  744,  746. 

alimentary,  683. 

pancreatic,  683. 

phloridzin,  682. 
Glycylalanin,  416. 
Glycylglycin,  416. 
Glyoxal,  406,  341,  514. 

methyl,  308. 
Glyoxalidins,  514. 
Giyoxalin,  306,  614. 
Glyoxals,  299. 
Gold.  193. 

fulminating,  396. 

trichlorid,  193. 
Gram,  6. 

calorie,  22. 

equivalent,  60,  64. 

molecule,  57. 
Granulone,  321. 
Grape  sugar,  314. 
Graphite,  188. 
Gravity.  6. 

specific,  10. 
Groups,  characterizing,  270. 
Guaiacol,  446.  448. 
Guanid,  cyanacetic,  534,  535. 
Guanidin,  388,  398,  403,  418,  527,  634,  635, 

579,  580,  631. 
Gnanidins,  substituted,  388. 
Guanids,  522,  §87. 


Guanin,  388,  532,  684,  593,  724. 
Guano,  237. 
Guaranin,  533. 
Gulose,  311. 
Gum  resins,  493. 
Gums,  321. 
Gun  cotton,  323. 
powder,  224. 
Guvacin,  549. 
Gypsum,  237. 

Hematin,  641,  668. 

Hematite,  197. 

Haematocrit,  650. 

Haematoidin,  636,  641,  666. 

Hematoporphyrin,  641,  664,  666,  725,  741. 

Hematuria,  741. 

Hemin,  603,  664. 

Heraochromogen,  663,  664. 

Hemocytolysis,  656. 

Hemoglobin,  641,  669,  676,  679,  689,  741. 

carbon  dioxid,  663. 

carbon  mouoxid,  662. 
Hemoirlobinometers,  677. 
Hemoglobins,  583. 
Hemoglobinuria.  641,  741. 
Hemolysins,  671. 
Hemolysis,  656,  671. 
Hemopyrroie.  510,  637. 
Halogens,  125. 
Halohydrins.  382. 

glycerol.  364. 

glycol,  36.3. 
Haptophores,  673,  674. 
Hausmannite,  195. 
Heat,  21,  46. 

atomic,  55. 

dynamic  theory  of,  24. 

effects  of,  21, 

expansion  by,  23. 

latent,  26. 
of  vapor,  33. 

measure  of,  22. 

mechanical  equivalent  of,  22. 

molecular,  58. 

of  combustion,  99. 

of  dissociation,  100. 

of  formation.  99. 

of  fusion,  26. 

of  neutralization,  100. 

of  precipitation,  98. 

of  reaction,  99. 

of  solution,  98. 

of  vaporization,  33. 

quantity  of,  21. 

specific,  33. 
Heavy  spar,  239. 
Helium,  55,  101,  103,  126. 
Hemi  group,  612,  618. 
Hemihedral  crystals,  16. 
Hemiterpenes,  487. 
Heptoses,  309,  310,  600. 
Heroin,  562. 

Heteroalbumose,  618,  614,  618. 
Heterocyclic  compounds,  272,  433,  607. 
Heteroxnnthin,  532,  688,  724.    . 
Hexacarbocyclic  compounds,  434,  435. 
Hexach  lore  thane,  281. 
Hexaglycylglycin,  416. 
Hexahydrobenzene.  434,  439,  486. 
Hexahydrocymene,  489,  490. 
Hexahydrophenol,  491. 


801 


INDEX 


Hezahydropyrasin,  520,  522.  ^ 

Hezabydropyridins,  618,  flS. 
Hezahydropyrimidln,  523. 
Hezamethylene,  484. 

tetramin,  301,  409. 
Heziteit,  298.  - 

Bezon  baaea,  408,  417,  516,  579,  581,  689. 
Hezonev,  417. 

Hezosea,  298,  301,  309,  310,  811,  600. 
Histidin,  417,  §16,  580,  586,  689,  633. 
HistOD,  588,  592. 

nucleates,  691. 
Hiatons.  582,  §87,  689. 
Hoffman's  Tiolet,  506. 
Homatropin,  665. 
Homolo^ns  series,  264. 
Horn  lead,  204. 
Horse-power,  46. 
Hydantoln,  406,  §1§. 
Hydracetin,  486. 
Hydraeids,  64.  ' 

Hydramins,  378,  888,  408,  581. 
Hydrastin,  463,  548. 
Hydrates,  115. 
Hydrasids,  890,  410, 
Hydrasin,  152,  389.  390. 

eomponnds,  484. 

hydrate,  512. 

sulfate,  389. 
Hydrasins,  890,  471. 

aromatic,  484. 
Hydraiobensene,  488,  484. 
Hydraso  compounds,  483. 
Hydrasones,  299,  482,  484,  491,  499*  518. 

aldehyde,  410. 

ketone,  410. 
Hydrindene,  494. 
Hydrindones,  499. 
Hydrion,  76. 

Hydroaromatie  eomponnds,  486. 
Hydrobensoin,  504. 
Hydrobilinibin,  637. 
Hydrocarbons,  263,  971,  273,  439. 

acetylene  series,  273,  494. 

alipbatio,  273. 

condensed,  493, 494. 

diacetylene,  273. 

diolefln,  273,  245. 

ethene  series,  273,  498. 

ethine  series,  273,  488. 

heptacarbocyclic,  434. 

hexacarbocyclic,  434. 

hydroaromatie,  486. 

hydrobeneenic,  439. 

methane  series,  273. 

monobensenic,  440. 

olefln-acetylene,  273. 

olefin  series,  273,  488. 

pentacarbocyclic,  434. 

saturated,  273.  434. 

tetracarbocyclic,  434. 

tricarbocyciic,  434. 
Hydrocele,  fluid  of,  693. 
Hydrocotarnin,  564,  566. 
Hydrojfen,  105,  113. 

antimouid,  183. 

arsenid,  170,  175,  640,  641. 

bromid,  134. 

chlorid,  130. 

cvanid,  391. 

d'ioxid.  123. 

fluorid,  126. 


Hydrogen,  iodid,  196. 

nitrate,  157. 

nitrid,  151. 

peutasulfld,  141. 

perozid,  198, 604. 

phosphids,  166. 

polysulflds,  191. 

ailicid,  191. 

sulfate,  144. 

aulftd,  139. 
Hydrolysis,  116. 
Uydronaphthalenes,  496. 
Hydropyridina,  519. 
Hydropyrimidtns,  522. 
Hydropyrroles,  611. 
Hydroqninolins,  544. 
Hydroquinone,  449,  606,  647* 
Hydrosulflds,  141. 
Hydroterpenea,  489. 
Hydrouracil,  523. 
Hydrozamins,  382. 
Hydrozldion,  76. 
Hydrozids,  64, 115. 

basic,  115. 

hydrocarbon  284. 
Hydrozy],  64,  76,  269,  369. 

alcoholic,  369,  370. 

phenolic,  369,  870. 
Hydrozylamin,  159, 299,  388,  400L 

compounds,  376. 
aromatic,  473. 
Hydrozylamina,  408. 
Hyicrins,  646,  648. 
Hygrometer,  1^, 
Hyoscin,  548,  562,  §§§. 
Hyoseyamin,  biS,  552,  §64. 
Hypereh1orhydria«  619. 
Hyperglyk»mia,  683,  746,  746. 
Hyperiflotonic,  657. 
Hypnone,.  456. 
Hypochlorhydria,  619. 
Hypophosphites,  167. 
Hypoxanthin,  532,  688,  534,  536.^ 

Iceland  spar,  237. 
Ichthulin,  586. 
Ichthylepidin,  583,  597. 
Ichthyol,  374. 
Idose,  311. 
Imidazole,  514. 
Imido  group,  380. 
Iraidoparaffins,  377. 
Imids,  387,  401,  408. 
Imin  bases,  377. 
Imins,  357. 
Immune  body,  672. 
Immunity,  669. 

acquired,  670. 

active,  670. 

natural,  670. 

passive,  670,  674. 
Impenetrabilitv,  3. 
Indene,  493,  494 
Indestructibility,  3. 
Index  of  refraction,  34. 
Indican,  467,  541,  542,  729. 

urinary,  541. 
Indicanin,'467. 
Indicanuria,  729. 
Indicators,  620. 
Indiglucin,  467. 
Indigo,  459,  4?2. 


INDEX 


80& 


Indi^ro  bine,  467,  503,  541,  948. 

carmine,  542. 

white,  542. 
IndiKOtin,  542. 
Indium,  55,  102,  103,  245. 
Indoanilin  dyes,  452. 

Indole,  538,  689,  540,  578,  579,  580, 581,  695, 
596,  597,  614,  646. 

homologies,  540. 
Indone,  499. 
Indophenin,  510. 
Indoxyl,  641,  542,  646,  728. 
Indulin  dyes,  450. 
Indulins.  520. 
Inertia,  4. 
Inosite,  489,  753. 
Insolubility,  27. 
Insulators,  27. 
Intermediate  body,  672. 
Intestinal  concretions,  649. 

gases,  647. 

secretions,  632. 
Intestine,  bacterial  action  in,  643. 

chemical  changes  in,  642. 

putrefaction  in,  643,  702,  729. 
Innlase,  605. 
Inulin,  315,  321,  605. 
Inversion,  816,  318. 
Invertase,  602,  605. 
Invertin,  465,  602  632,  643. 
lodanilins,  475. 
lodidion,  137. 
lodids,  1.36. 
lodin,  125,  186. 

greens,  506. 

number,  HUbPs,  429. 

oxacids  of,  137. 
Iodoform,  281. 
lodol,  511. 

lodophenols,  448,  449. 
lodopropane,  382. 
lodoquinin  sulfate,  557. 
Ionization,  70,  72. 
Ions,  39,  44,  64,  72,  83. 
Iridium,  213. 
Iron,  194,  197. 

acetates  of,  201. 

bromids  of,  200. 

chlorids  of,  199,  200. 

citrates  of,  202. 

dialysed,  199. 

galvanized,  243. 

group,  194. 

hydrates  of,  198. 

in  bile,  641. 

iodids  of,  200. 

magnetic  oxid  of,  198. 

nitrates  of,  201. 

oxids  of,  198. 

phosphates  of,  201. 

reduced,  198. 

salts  of,  200. 

spathic,  202. 

sulflds  of,  199. 

tartrates  of,  202. 
Ironstone,  197. 

Isatin,  458,  47?,  510,  641,  642. 
Isatoxin,  542. 
Isinglass,  596. 
Isoacetonitril,  394. 
Isoalcohols,  285. 
Isobenzonitril,  394,  476. 


Isobntylearbinol,  639. 

Isochoiin,  888,  385. 

Isocoumarin,  539. 

Isocyanates,  396 

Isocyanids,  380,  394,  401« 

Isodipyridin,  551. 

Isodulcite,  311. 

Isoglucosamin,  388.  ' 

Isoindole,  688,  541. 

Isomaltose,  314,  819,  607,  6481} 

Isomerism,  265,  436. 

place,  339,  412. 

position,  339. 

space,  311,  430. 

stereo,  311. 
Isomorphism,  16. 
Isonicotin,  545. 
Isonitrils,  380,  394. 
Isopelletierin,  549. 
Isoprene,  426. 
Isopropylamin,  382. 
Isopropylbenzene,  441. 
Isopyrazolon,  512. 
Isoquinolin,  538,  644. 

alkaloids,  548,  66S,  56S. 
Isoserin,  417,  480. 
Isosmotic,  67. 
Isotonic  coefficient,  657. 
Ivory  black,  189. 

Jaborandin,  556. 
Jaborin,  549,  556. 
Japaconin,  569. 
Japaconitin,  569. 
Javelle  water,  224* 
Jecorin,  654. 
Jervin,  570. 
Joule,  8. 

Joule's  equivalent,  23. 
Juvacin,  548. 

Kairin,  544. 
Kathode,  42. 

Rations,  44.  ' 

Kelp,  135. 
Keratins,  583,  696. 
Keratinoses,  602. 
Kermes  mineral,  185. 
Kerosene,  276. 
Ketohydrazones,  382,  486. 
Ketohydrocymenes,  491. 
Ketohydroglyoxalins,  616. 
Ketols,  308,  309. 
Ketomenthadi^nes,  491. 
Ketomenthans,  491. 
Ketomenthenes,  491. 
Ketone  acids,  339,  340,  847» 

alcohols,  299,  808. 

dimethyl,  307. 

diphenyl,  604. 

diphenylene,  499. 

fluorene,  499. 

form,  537. 

glycerol,  310. 

halids,  278. 

hydrazones,  410. 

methylphenyl,  463. 

naphthylraethyl,  499. 

phenylraethyl,  465. 

pimelin,  491. 
Ketones,  282, 283,  284, 286, 298, 807,824,826, 
326,  339,  340,  391,  398,  409,  4BA.  fil7. 


806 


INDEX 


Ketones,  acetylene,  4S8. 

aruiiiaUcy  455. 

bensenie,  443. 

eamphMi,  491,  482. 

eyelie,  835. 

dlphenyl,  603. 

hydroaromatie,  489,  491. 

naphthyl,  499. 

olefln,  428. 

terpan,  491. 
Ketopentoeet,  310. 
Ketopiperasins,  622. 
Retopiperidins,  413. 
Ketopniins,  531,  532,  633. 
Ketopyrimidins,  624. 
Ketoaes,  809, 310.  321,  325,  328,  486. 
Ketoxima,  879,  382,  409,  410,  481. 
Kilagmm,  779. 
Kilojonle;  23. 
KUottieter,  1,  778. 
KUowatt,  46. 
Knf '8  yellow,  174. 
KnaU-gaa,  45. 
Knook-ont^fopa,  305.  '^ 
Koprostearin,  6tt.  "^     ^ 
Korneto,  597. 
Krypton,  55, 101,  106, 126. 
Kyanol,  473. 
Kynnrin,  544. 

Labarraque'a  solution,  220. 

Labile  snbstanees,  87. 

Labradorite,  48. 

Lacease,  606. 

Laoeol,  606. 

Lacmoid,  449. 

Laetalbumin,  582,  764. 

Lactam,  metoylgnanidlnaeetlo,  390. 

LacUmid.  411,  414. 

Lactams,  384,  418,  478. 

Lactase,  632. 

Lactids,  868,  412. 

Lactine,  318. 

Lactoglobulin,  582,  764. 

Lactometer,  762. 

Lactone,  gluconic,  369. 

Lactones,  314,  340,  343,  868,  428,  462,  500, 

504. 
Lactose,  316.  818,  600,  643,  644,  681,  752. 
LffivojB^yrous  substances,  38, 
Levulose,  815,  752. 
Laiose,  752. 
Lampblack,  189. 
Lanolin,  638, 
Lanthaniura,  55,  102.  103. 
Lapis  infernalis,  231. 
Laughing  gan,  153. 
Lauth's  violet,  520. 
Law,  Boyie-Mariotte,  19,  25,  26,  31. 

Dalton's,  20. 

Dalton-GayLussac,  23. 

Faraday's,  44. 

of  Ampere,  52. 

of  Avogadro,  52. 

of  Charles,  23. 

of  Dalton,  49. 

of  definite  proportions,  48. 

of  Faraday,  71. 

of  Quid  berg  and  Waage,  93. 

of  multiple  proportions,  49. 

of  Raoult,  68. 

of  reciprocal  proportions,  49. 


Law  of  Elcbter*  48. 

c*f  Van^t  Bon,  89, 

of  Weuxtl,  4y. 

Ufam^a,  42. 

periodlo,  102,  ]Q4, 
Law  a,  Berthollet's,  77« 

OsyLitssac^Si  52i 

Nt'Wtinf »,  4. 
Lead,  204. 

acetates,  206. 

blaek,  188. 

earbonate,  206. 

ehlorid,  206. 

ehromate,  206. 

diozld,  205. 

glyeoeholate,  685. 

gronp,  204. 

iodid,  206. 

monozid,  205. 

nitrates,  206. 

ortiionltrate,  206.    . 

ozlds,  206. 

oxychlorlds,  906. 

pyronlteate,  266.   ' 

red,  266. 

salts  of,  206. 

snbaeetate,  206. 

sulfate,  206. 

snlfld,  206. 

tauroeholate,  636. 

white,  207. 
Leads,  electric,  40. 
Leather,  596. 

LeChatelier.  theorem  of,  88. 
Leeithalbumin,  588. 
Lecithins,  967,  383,  684,  686,  631,  694,  644» 

654,666. 
Legamln,  587. 
Lepidin,  559. 
Lepidins,  544. 
Letbol,  363. 
Leucanilins,  505. 

Leucin,   414,  467,  479,  580,  581,  595,  596, 
614,  617,  626,  633,  686,  757,  758.  763. 
Leucinimid,  688,  630. 
Leucins,  414. 
Leucocytes.  656,  666. 
Leucomalns,  390,  570,  571. 
Leucomalacbite  green,  505. 
Leuconuclein,  592,  669. 
Leucopararosanilin,  503. 
Leucylleucin.  416,  522,  630. 
Leucylprolin,  511. 
Levigation,  238. 
Leyden  crystals,  387. 
Lichen  in,  321. 
Lieberklihn's  jelly,  590. 
Light,  34. 

chemical  effects  of,  39. 

dispersion  of,  34. 

refraction  of,  34. 

wave-lengths  of,  36. 
Lime,  235. 

milk  of,  236. 

wRter,  236. 
Limonene,  487,  490. 

tetrabromids,  487. 
Limestone,  235,  237. 
Linalool,  427,  488. 
Linkages,  268. 

Lipases,  605,  609,  619,  627,  631,  655. 
Liquids,  18,  30. 


INDEX 


807 


Liquids,  diffusion  of,  18. 

immiscible,  60. 

vapor  tension  of,  31. 
Liter,  1. 
Litharge,  205. 
Lithium,  215. 

bromid,  215. 

carbonate,  215. 

chlorid,  215. 

urates,  531. 
Liver,  action  on  carbohydrates,  681. 
on  fats,  681. 
on  poisons,  678,  684. 
on  proteins,  681. 

blood  changes  in,  678,  680. 
^       carbohydrates  of,  679. 

fats  in,'  680. 

formation  of  ester  sulfates,  684. 
of  urea,  685,  720,  721. 
of  uric  acid,  684,  685,  721. 

glycogenic  function  of,  681,  682,  745. 

iron  proteins  in,  641,  679. 

proteins  of,  679. 

sugar,  314. 

syntheses  in,  680,  683. 
LoadHtone,  198. 
Lucifer  disease,  164. 
Lunar  caustic,  231. 
Luteins,  586,  655. 
Lutidins,  518. 
Lycootonin,  568. 
Lymph,  692. 

plasma,  692. 
Lyons  blue,  506. 
Lysatinin,  419. 
Lysidin,  3So,  614. 

urate,  531. 
Lysin,  403.  818,  480,  580,  581,  589,  595,  617, 

629,  633,  763. 
Lyslns,  670,  671. 
Lysol,  446. 

Magenta,  506. 
Magnesia,  241. 
Magnesite,  241. 
Magnettium,  240. 

carbonate,  241,  242. 

chlorid,  241. 

group, 240. 

hvdroxid,  241. 

oxid,  241. 

phosphates,  241. 

pyrophosphate,  241. 

sulfate,  241,  576. 
Malarhife,  2r)0. 

gre*:-!!,  50.'). 
Mslonninld.  407.  411. 
Malonoiiitril,  .395. 
Bfalonyliliniethylurea,  526. 
Malonvlguanid,  .527. 
Malonvlnrea,  522,  626,  529. 
Malt,  287. 

Maltase,  602,  603,  604,  607,  632,  666. 
Maltose,  287,  316,   819,  322,  600,  602,  604, 

607,  631,  643,  644,  681. 
Manganates,  196. 
Manganese,  194,  195. 

chlorids,  196. 

ozids,  196. 

salts,  196. 
Manganite,  195. 
Mannitan,  298. 


Mannite,  298. 
Mannitol,  298,  314. 

hexacetyl,  367. 

hexanitro,  368. 
Mannitols,  343. 
Mannose,  311,  814. 
Marble,  235,  237. 
Marsh  gas,  275. 
Martins*  yellow,  498. 
Mass,  5. 

action,  92. 
Massicot.  205. 
Matter,  2. 

states  of,  13. 
Measures,  778. 
Meconin,  462.  564,  566. 
Meconium,  648. 
Meerschaum,  240. 
Megohm,  46. 
Melam,  537. 
Melamin,  537. 
Melanin,  743. 
Melanlns,  579,  697. 
Melanoidins,  579,  580. 
Melecitose,  319. 
Melissin.  303. 
Melisyl  palmitate,  363. 
Melitose,  319. 
Membranes,  permeable,  18. 

semipermeable,  19. 
Menthadi^ne,  490. 
Menthan,  490. 
Menthene,  488,  490. 
Menthol,  489,  490,  491. 
Menthone,  491. 
Menthoxim,  491. 
Mercaptals,  373. 
Mercaptan,  871,  579,  646. 
Mercaptans,  871,  580. 
Mercaptids,  371,  372,  373. 
Mercaptol,  373 

Mercuramnionium  chlorid,  268. 
Mercurdianimonium  chlorid,  257. 
Mercuric  chlorid,  257. 

cyanid,  259,  .^5. 

fulminate,  396. 

iodid,  258. 

nitrate,  259. 

oxid,  255. 

sulfate,  260. 

sulfld.  265. 

sulfochlorid,  267. 
Mercurous  chlorid,  256. 

iodid,  258. 

nitrate.  259. 

oxid,  255. 

sulfate,  260. 
Mercury,  250,  254. 

chloramidid,  258. 

chlorids,  256. 

form  am  id,  401. 

fulminating,  396. 

iodids,  258. 

nitrates,  259. 

oxids,  255. 

phenate,  446. 

sulfates,  260. 

sulflds,  256. 
Meroquinene,  .509. 
Mesityl  oxid.  428. 
Mesitylene,  442. 

glycerol,  453. 


808 


INDEX 


Mesozftlytnrea,  348,  627. 
MetMshloral,  303. 
Hetft  compounds,  437. 
Metadiailn  620,621. 
Metadiozybensefne,  440. 
MetftlbnmiD,  694. 
Metaldehyde,  303. 
Metalloeyanids,  308. 
MetiOs,  101, 102. 
Metamerism,  266. 
Metaphenyienedittnin,  478^ 
Metatriasin,  636. 
Metazylene,  442. 
Meter,  1,  778. 
Methacetin,  477. 
MethflBmoglobin,  662.    - 
Methane,  276. 

disulf ethyldimetiiyl,  274. 

dlthioethyldtmethyl,  873. 

series,  273. 
Methene  ohlorid,  278. 

dimethylate,  296,  S06. 

glycol,  295. 

iodid.  301. 
Methenyl,  275. 

ehlorid,  278. 

iodid,  280. 
Methine,  275. 

Method,  see  Proeess,  Test. 
Methol,  363. 
Methoxyl,  270. 
Methyl,  275. 

aeetamid,  476. 

aeetylurea,  407. 

amidoaoetate,  414. 

amin,  881,  414. 

anillD,  476. 

anthraqninooe,  500. 

bensene,  439,  441. 

beDsoylcyanhydrin,  488* 

bensoylecgonate,  556. 

blue,  506. 

bromid,  280. 

carbylarain,  394. 

ehlorid.  878,  472. 

cyanid,  894,  401. 

dichloropyrimidin,  521. 

di vinyl,  426. 

ethylbenzenes,  441. 

ethyl  ozid,  348. 

ethylpyrimidin,  518. 

glycocoll.  389.  412,  414. 

Klyoxalidin,  514. 

fruanidin,  389. 

guanin,  536. 

heptenone,  428. 

hydantoTn,  414,  515. 

hydrid,  275. 

hydroxid,  286. 

indoles,  486,  540,  541. 

iodid,  280,  311,  476,  513. 

isocyanld,  394. 

isopropylbensenes,  441,  442. 

isopropylcarblnol,  294. 

isopropylphenoU,  447. 

ketopurins,  532. 

morphin,  562,  564,  566. 

morphinmetbine,  566. 

oxalate,  387. 

oxid,  349. 

penthiopbene,  484. 

phenylhydrazin,  484. 


Methyl  piperidin,  610. 

propylbensenes,  441. 

propylcarbinol,  883. 

propylpyrrole,  510. 

pseudotiiioorea,  524,  688. 

porins,  628,  631. 

pyridins,  518. 

pyrimidin,  821. 

P3rrroles.  510. 

qninin,  558. 

(luinolins,  543,  544. 

tropidin,  652. 

nraeUs.  362.  521^  8S4,  585,  61 

nramin,  389. 

area,  407. 

xanthine,  526,  888. 
Methylal,  295,  806. 
Methylene,  275. 

bine,  506,  8S0. 

bromid,  495. 

ehlorid,  878,  602. 

eyanid,  396. 

diethylsalfonSj  878. 

diiodid,  373. 

iodid,  423. 

mercaptal,  373. 

ozids,  299. 
MethyUa,  381. 
Mho,  46. 
Mica,  240,  248. 
Microhm,  46. 
Microspeetroseope,  86. 
Milk,  617,  761. 

abnormal,  766. 

adulterations  of,  768. 

analysis  of,  766. 

casein  in,  763. 

composition  of,  768. 

corpuscles,  762. 

cows',  761.  765. 

hnman,  764. 

lactalbumin  in,  764. 

lactoglobulin  in,  764. 

physical  properties  of,  761« 

plasma,  763. 

reaction  of,  761. 

salts  of,  764. 

skimmed,  762. 

souring  of,  761. 
Milliampere,  44. 
Mineral  green,  252. 
Minium,  205. 
Miricyl  hydroxid.  294. 
Mixtures,  isomorphons,  51. 

mechanical,  47,  54. 

of  gases,  49. 

of  liquids,  50. 

of  solids,  51. 

of  vapors,  49. 

physical,  49,  54. 
Mol,  57. 
Molasses.  317. 
Molecule,  52.  53. 
Molecular  conductivity,  74. 

beat,  58. 
of  vaporization,  58. 

theory,  52. 

volume,  57. 

weight,  56. 
Molybdenum,  192. 
Momentum,  7. 
Monacetaraid,  400. 


INDEX 


809 


Monacetin,  296. 
Mouacidylureas,  406. 
Monamids,  379,  397,  899. 

cyclic,  515. 

inuniiL-idylT  40G, 

?^tfco Hilary,  400. 

leniary,  40fl. 
Moimniin*,  370,  S7T.  378.  581. 

jiriraarVj  377,  :t78,  379. 

s-efondary,  B77,  379. 

tertiiiry,  \ill,  379* 
Idotifttftleft,  51      512, 
Mtmr»btDz.tmic  compounda,  456. 

|i!oni>cbloraiii]h>»,  47'i. 
Mfjnoeblomi ethyl  chJorid,  278. 
Mi^tkiMjIi^troNi-n^erit'.  4:42,  444. 
Mmiif-ly.^i  ri>l^.  2Wk 
^uui)hytlr(>hfii7.exiic  compounds,  439. 
Mouoketouea,  307« 
Mononttrolienzf^iiet  471. 
Mi:inoii(ltroet1inno,  rt7(j. 
Manonltropnrafllni!*  37C. 
McmoriitfoijbtJDitk,  4?2. 
|doiiopb«uy]  ttulfate,  470, 
lloD4>hai^e)mi-idi},  309. 
HoDose^,  309. 
Monoid'    salt.  201. 
Mcinureld»,  4CMj. 
Morphln.  :^rj%  682,  565,  566,  567. 

diaeetyl,  361?. 
Mdrphium,  547 

F II]  fate.  378,  546,  663. 
MorpholiD,  520. 
Morrhuin,  367. 
Motion.  4. 
MuiMtHti   5B7 
Maeilages.  321. 

}!ucoiit-.  583- 
Kli*"ar,  600   602. 
Murexid    526,  §27. 
Miiscarifi.  383,  385,  581. 
Uuaete  plu^tnin^  585. 

serum,  585. 

stroma,  585. 

tja^tic^,  585. 
MuRlard  oils,  380,  397. 
Hyasin  r'oni pounds,  522. 
Mvdak'in.  386. 
Uydin,  470. 
My  aire  n,  582.  585. 

flbriti.  5K5. 
iiDlublf^,  58S* 
MyoMti.n82.  585. 

fiijrin   rm. 
Myrcene,  426. 
Myrosin,  482,  465,  467,  606. 

Napellin,  568. 
Naphtim,  276. 
llaphthn^ue.  457,  493,  494,  iVi, 

balids,  497. 

homolofTues,  495. 

phenantbrene,  494. 

i*ulfoohlorid.  480,  500. 

sulfoglycin,  767. 
Naphthalinolin,  544. 
Naphtbenes,  486. 
Naphtbol  blue,  520. 

yellow,  498. 


NaphthoIf>.  439.  495,  497,  498.  501. 

subtttiLuud,  i\t6. 
Naphtboquinonew,  495.  499. 
Napbtbylamtnii,  498,  499,  600,  538. 
Kapbthyleni'st,  486. 
Nar(!efri.  548.  m!2,  564.  565,  566. 
Karcf^tio,  4ti2,  46^1,  548,  562,  464,  665,  566. 
Na^cftit  state.  1(jS, 
Kegatlve  plate,  40. 

pole,  41. 
Neodvmium,  55.  102,  103. 
Neon!  55,  101,  103, 125. 
Neuridt-ti,  '\H(\, 
Keiiriti.  384   385,  581. 
Neumkerutlu,  595. 
Kickel,  249. 

sulfate,  249. 
Nicotidid  545. 
Kicotln,  5ie^  545,  548,  ••!. 
Nile  blue,  520, 
Niobium,  55,  101,  191. 
Nitranilins,  475. 
Nitrates,  U8. 
Nitre,  223. 
Nitril  bases,  377. 
Nitril,  lactic,  398. 

Nitrils,  301,  1128,  379,  388,  391,  S98,  394, 
3115,  400,  410. 

arumsUlo,  456.  4*j9- 

of  oarbuiiip  acidaf  395* 

of  dicartioxylic  acids,  394. 

of  fatly  nridf*.  393. 

of  ketoue  acldM,  393,  89S. 

of  oicyncidN,  300.  397. 

of  tblocarbonle  aolds,  395. 
Nitrites.  156. 
Nitro,  376. 

acetopbeDOne,  466. 

adds.  410. 

alcohols,  408. 

aldebyden,  408. 

aolsols.  472, 

beiiEeut's,  440,  471,  473,  474. 

benzole,  471. 

creaol,«.T  472. 

diph«nyU,  50^. 
Nitrot^en,  148, 

acids  of,  156. 

amid,  377,  379,  380. 

amino,  580. 

azo,  377. 

basic.  580. 

bromid,  153. 

cblorid,  153. 

diamido,  580. 

dioxid,  154. 

frroup,  148. 

Lalids,  153. 

humu»,  580. 

bydraso,  377. 

imid,  377. 

mooamidot  680. 

monoxlfl,  ]53f 

nitril,  377,  379,380. 

ojEidH  of.  163. 

pentoxid,  156* 

ptr.-i.K  ]5r;. 

primary.  377. 
protoxid,  153. 
secondary,  377. 
tertiary,  377. 
tetroxid,  377. 


^Mirusu  g^ruup,  «>eu. 
Nitrosonaphtbols,  498. 
Nitrosophenols,  472. 
Nitrosvl  bichlorid.  158. 

chiorid.  158,  413,  487. 
Nitrotoluenes,  471. 
Nitrouracil,  529. 
Nitrous  fumes,  155. 

oxid,  153. 
Nitroxanthin,  534. 
Nomenclature,  80,  771. 

of  alcohols,  285. 

of  amins,  378. 

of  carbon  compounds,  271. 
Non-metals,  101. 
Nonoses,  307,  310. 
Normal  conditions,  9,  24. 

gas,  10. 

volume,  24. 
Nortropan,  552. 
Nubecula,  731,  740. 
Nuclein  bases,  531. 
Nucleins,  591,  692,  619. 
Nucleoalbumins,  582,  686. 
Nucleohiston,  583,  588,  691,  666,  669. 
Nucleoproteids,  583,  691,  592,  593,  631,  712. 
721,  724. 

Occlusion,  107. 
Octoses,  309,  310,  600. 
CEnoxidase,  606. 
Ohm,  46. 
Oil,  bone,  517. 

cod-liver,  367. 

mustard,  432. 

of  bitter  almonds,392,  453,  454. 

of  Dippel,  510,  517,  518. 

of  turpentine.  492. 

of  vitriol.  144. 

sperm,  367. 
Oils,  drying,  366. 

e.Hsential,  425,  428,  486,  488. 

fixed.  366. 

greasy,  366. 

lubricating,  276. 

mustard,  380,  397. 

neutral.  .306. 

semidrvinif,  366. 

volatile,  366,  486,  488. 
Olefin  Tit  tras,  42,'{. 


v^riuu  actus,  jo/. 

compounds,  437. 

diazin,  520, 521. 

dioxybenseue,  448. 

oxycarbinol,  475. 

toluenesulfoamid,  470. 

triazin,  436. 
Osazones,  299,  311,  316,  319.  484,  486. 
Osmium,  192. 
Osmosis,  18. 
Osmotic  equivalent,  18. 

pressure,  66. 
of  blood,  657,  658. 
Ossein,  596. 
Otoliths,  238. 
Ovialbumins,  £82,  684. 
Oviglobulins.  .^82,  684. 
Ovimucoid,  584. 
Ovivitellin,  586. 
Oxacids,  64. 

Oxalylurea,  408,  616,  527,  636. 
Oxamid,  401,  407. 
Oxazins,  520. 
Oxethylamin,  408. 
Oxhydryl,  64. 
Oxidases,  606. 
Oxidation,  111. 
Oxids.  111. 

alkylen,  382. 

basic,  112. 

indifferent,  112. 

neutral,  112, 

saline,  112. 
Oxim  group,  388. 
Oximid,  401. 
Oximidoacetone,  .398. 
Oxims,  299,  452,  499. 
Oxindole,  478,  539.  641. 
Oxyacids,  64,  300,  888,  362,  398,  413. 
Oxyaldehyde  ketones,  308. 
Oxyaldehydes,  300,  808,  309,  335,  339. 
Oxyamids,  411. 
Oxyamins,  888,  385,  408. 
Oxyanthracenes,  499. 
Oxyazo  compounds,  482. 
Oxybenzaldehyde,  454. 
Oxycholin,  384. 
Oxycinchonin,  558. 
Oxycyanids,  300,  887,  339. 
Oxydimorphin,  563. 


INDEX 


811 


Ozymorphin,  563. 

Oxynaphthalenes,  497. 

Oxynaphthylamin,  501. 

Ozyneorin,  384. 

Oxyphenylethylamin,  476,  479,  617,  631. 

Oxypiperidins,  413. 

Oxypurins   531,  532,  533. 

Oxypyrimidins,  523. 

Oxyquinolins,  544. 

OxysaltH,  66. 

Oxyoracils,  529. 

Osocerite,  374. 

Ozone,  112. 

Palladiam,  213. 

Pancreatic  diabetes,  683,  746. 

diastase,  643. 

digrestion,  625. 

secretion,  625,  626. 
Papaveraldin,  565. 
Papaverin,  548,  562,  664,  565,  666. 
Papayotin,  606. 
Para  acetoanisidin,  477. 

acetophenetidin,  477. 
Paralbumin.  595. 
Para  amidoazobenzene,  483. 

amidodiphenyl,  439,  602. 

amidopbenol,  475. 

amidophenylalanin,  479. 

amidothiazin,  520. 

aiuidotriplienylmetbane,  504. 

azoamido  compounds,  482. 

compounds,  437. 

coniin,  550. 

cresol,  646,  647. 

diumidodiphenyl,  484. 

diamidotripbenylmethane,  506. 

diazin,  520,  621.  522. 

dioxybenzene.  449. 

eu^lobulin,  353. 
Paraffin,  276. 

series,  273. 
Paraffius,  273. 

amido.  377. 

diamido,  387. 

dibalogen,  277. 

dinitro,  .385. 

halid,  277. 

Iraido,  ,377. 

monolialogen,  277. 

nitro,  Me. 

nitrogen  derivatives  of,  376. 

oxidation  products  of,  282. 

sulfur  derivatives  of,  370. 
Para  formaldehyde,  301. 

globulin.  652. 

histon,  588. 
Paraldehyde,  303. 
Paramorphin,  .'>65. 
Paramylum,  .321. 
Para  n'itrophenylalanin,  479. 

nitroKophenol,  473. 

nudeins,  r)86. 

oxyphenylalanin,  478. 

phenetidin,  477. 

phenylenediamin,  484. 

-pseudoglobulin,  653. 

rosanilin,  503. 

tetramethyldiamidotriphenylmethane, 
.50.). 

thioforraaldehyde,  373. 

tiiasins,  394,  536,  687. 


Pnra  xanthin,  532,  688,  724. 

xylene,  442. 
Parchment  paper,  322. 
Paris  green,  176,  252. 
Parvolins,  518. 
Pearl  ash,  225. 
Pear  oil,  363. 
Pelletlerin,  .•>48,  549. 
Penicilium,  342,  601,  602. 
Pentabromanilin,  475. 
Pentamethylenediamio,  886,  418,  619. 
Pentane,  518. 
Pentapeptids,  416. 
Pentene,  425. 
Pentites,  297. 
Pentole,  507. 
Pentosanes,  311. 
Pentoses,  298,  309,  810,  323,  326,  465,  509, 

593.  600,  763. 
Pentosids,  465. 
Pentosuria,  753. 

Pepsin,  590,  603,  610,  620,  624,  645. 
Pepsinogen,  610,  611,  884. 
Peptoids,  G16,  617,  618,  629. 
Peptomelanin,  615. 
Peptone  plasma,  650. 

urinary,  739. 
Peptones,  583,  614,  616,  617,  618,  625,  628, 

629,  630,  645. 
Peptonuria,  739. 
Periodic  law,  102,  104. 
Periasads,  59. 
Permanganates,  196. 
Peroxids,  352 
Petroleum,  276. 

ether,  276. 
Pfeiffer's  phenomenon,  672. 
Phagocytosis,  670. 
Phallin.  573. 
Phase  rule,  93. 
Phases,  93. 
Phellandrin,  488. 
Phenacetin,  477. 
Phenanthrene,  493,  496,  497,  501. 

alkaloids,  548,  668,  565. 

quinolin,  563. 
Phenanthridin.  5.38. 
Phenanthrolins,  545. 
Phenanthroquinone,  496. 
Phenates.  446.  464. 
Phenazone,  521. 
Phenetidin*.  472,  477. 
Phenetol,  464. 
Phenol,  444,  470,  472,  581,  646,  647. 

aldehydes,  458. 

ally  1. '450. 

cymlic.  447. 

dyes,  450. 

esters,  446. 

phthalein,  451. 

propenvl,  450. 
Phenols,  448.  469,  481,  482,  491. 

benzylic,  446. 

cresylic,  446. 

dihydric.  448. 

diphenyl,  502. 

methylisopropyl,  447. 

monohydric,  444. 

naphthalene,  497. 

substituted,  447. 

trihydric,  449. 

unsaturated,  450. 


812 


INDEX 


Phenones,  455. 
Phenyl,  443,  446. 

aeetoldehyde,  479. 

Beetnmid,  475. 

aeetTlene,  442,  458. 

acrolein,  454. 

alanin,  416,  47S,  479,  595,  596,  614,  617, 
763. 

ftlkylhydrftsins,  484. 

amixis,  47S,  476. 

benzenes,  601. 

earbylamin,  476. 

eyanidins,  537. 

dimethylpyrazolon,  513. 
Phenylene,  443. 

diainins,  476. 
Phenyl  esters,  446. 

ethene,  442. 

ether,  464. 

ethylamin,  582. 

glueosid,  465. 

fflyeoeoll,  47S,  479,  539,  542. 

goanidln,  480. 

hydrasids,  343. 

hydrasin,  299,  386,  390,  406,  410,  494, 
486,  513. 

hydrasones,  494,  485,  486,  540. 

hydrozid,  444. 

hydroxylamln,  473. 

iodid,  444. 

isoeyanid,  394,  476. 

methylpyrasoles,  513. 

phosphates,  444. 

phosphoric  tetraehlorid,  444. 

pyridins,  .519. 

pyridyls,  545. 

salicylate,  459. 

semiearbasid,  405. 

snlfld,  469. 

sulfochlorid,  480. 

uracil,  525. 

urea.  480. 

urethans,  402,  %80. 
Phlebin,  059. 
Phloretin,  467. 
Phloridzin,  467. 

diabetes.  682,  744. 
Phloroglucin,  449,  467. 
Phloroglucite,  489. 
Phlorose,  467. 
Phoroue,  428. 
Phosgene,  304,  352,  838. 
Phosphaiuin,  165. 
Phosphates,  167. 
PhosphiD,  165. 
Phosphins,  422. 
Phosphoglobulins,  586. 
Phosphoglycoproteids,  583. 
Phosphonia,  165. 
Phosphorus   148,  169. 

acids  of,  166. 

analysis  of,  162. 

bromids,  165. 

fluorids,  165. 

halids,  165,  277,  352. 

iodids,  165. 

organic  compounds  of,  422. 

oxids,  166. 

oxychlorid,  165. 

pentachlorid,  166,  299, 300, 443,  463,  469. 

pentoxid,  166. 

trichlorid,  165. 


Phosphoms  triozid,  166.  * 

Phthulamid,  477. 

PhthaleXns,  444,  451,  468,  604. 

Phthalid,  462. 

nithaUds,  504. 

Phthalimid,  417,  477. 

Phyelte,  297. 

Physostigmin,  570. 

Phytoglobolin,  686. 

PhytovitelUn,  582,  686. 

Pfeene,  493.  494,  499. 

PieoUns,  918,  519,  560. 

Pieramid,  475. 

Pilocarpene,  556. 

PUooarpidin,  556. 

PUoearpin.  519,  548,  549,  996. 

Ptmeltn  ketone,  491. 

Pinene,  489,  490. 

dibromo,  488. 

hydroehlorid,  488. 
nperasin,  387,  989. 

urate,  531. 
Piperidein,  519. 

alkaloids,  548,  549. 
Piperidin.  301,  387,  608,  616,  618,  •!•,  660. 

alkaloids,  548,  549. 
Plperidlns,  517,  919. 
Pfperidium  chlorid,  378. 
Plperin,  458,  519,  548,  990. 
Pitch,  440. 
Plaques,  656,  667. 
Plasma,  649,  650. 

oxalate,  650. 

peptone,  650. 

salt,  660. 

salts  of,  655. 
Flastefns,  629. 
Plaster  of  Paris,  237. 
Platinic  chlorid,  214. 
Platinocyanids,  399. 
Platinum,  213,  214. 

black,  214. 

colloidal,  604. 

group,  213. 

spongy,  214. 
Plumbago,  188. 
Plumbates,  205. 
Plum  bites,  205. 
Poeonin,  450. 
Poisons,  132. 

mineral,  182. 
Polarimetry,  37. 
Polarization,  electric,  44. 
Poles,  electric,  40. 
Polymerization,  301,  433. 
Polymethylenes,  434. 
Polypeptids,  415,  522,  578,  579,  581,  617, 

629,  630. 
Polysaccharids,  309,  311,  919,  644. 
Polyuria,  695. 
Pompholix,  243. 
Ponceau,  498. 
Populin,  468. 
Porcelain,  248. 
Porter,  290. 
Positive  plate,  40. 

pole,  41. 
Potash,  215,  222,  225. 
Potassa,  222. 
Potassium,  215,  222. 

acetate,  225. 

aluminate,  247. 


INDEX 


813 


Potassium  arsenite,  175. 

bromate,  223. 

brouiid,  223. 

carbonates,  225. 

chlorate,  224. 

chloridf  223. 

cyanid,  228. 

dicbromate,  224. 

disulfld,  223. 

ethylsulfate,  393. 

ferricvaiiid,  229. 

ferrocyanid,  228.  353. 

hypochlorite,  224. 

hydroxid,  222. 

iodhvdrargyrate,  548. 

iodid,  223. 

monosulttd,  223. 

myronate,  432. 

nitrate,  223. 

oxalates,  226. 

oxids,  222. 

pentasulfid,  223. 

permanganate,  225. 

phenate,  444,  446,  465,  470. 

pyrogallate,  450. 

sulfates,  224. 

sulfbydrate,  223. 

Bulfids,  223. 

sulfites,  224. 

tartrates,  226. 

thiocyanate,  607. 

trisulfid,  223. 

urates,  531. 
Potential  difference,  41. 

fall  of,  43. 

gradient,  43. 
Pouchet's  base,  733. 
Powder  of  Algaroth,  184. 
Power,  8,  46. 

Praseodymium,  55,  102,  103. 
Precipitation  limits,  576,  577. 
Precipitins,  670,  672,  675. 
Pressure,  10,  30. 

critical,  29,  30. 

osmotic,  66. 

partial,  20. 

solution,  70. 

standard,  24. 
Process  (see  also  Reagent,  BeactiODi  Test). 

Babcock's,  765. 

Pehling's,  751,  752. 

Fischer  and  BergelFs,  757. 

Pocke's,  750. 

Freund  and  Lieblein's,  698. 

Hammerschlag's,  675. 

Knapp'}*,  750. 

KUlz's,  756. 

IjOwv'.s,  676. 

Martius  and  LUttke's,  622. 

Mohr's.  701. 

Morner  and  Sjoqvist's,  622. 

Pan  urn's.  7.%,  739. 

RittenhauMen's,  766. 

Robert's,  752. 

Sharpies',  765. 

Volhard'fl,  701. 
Proenzymes,  604. 
Prolin,  416,  611,  763. 
Propahlehyde.  305. 
Propantriol,  295,  296. 
Propargyl  halids,  426. 
Propenyl  anisol,  450. 


Propenyl  phenol,  450. 
Propepsin,  611. 
Propeptoues,  582. 
Propidene  phenylhydrazin,  541. 
Propyl  am  in,  382. 

benzene,  441. 

carbinol,  292. 

hydroxid,  291. 

piperidin,  519,  550. 

pseudonitrol,  376. 

pyridins,  518. 
Prosecretin,  626. 
Protamiu  nucleates,  591. 
Protamins,  417,  580,  582,  587,  688,  630. 
Proteids,  583,  691,  610,  630. 
Proteinochrome,  540. 
Proteinochromogen,  540. 
Proteins,  676,  643,  645,  646,  733. 

classification  of,  582. 

color  reactions  of,  577. 

decompositions  of,  579. 
Proteoses,  612. 

Prothrombin,  668,  654,  666,  668. 
Protoalbumoses,  613,  614,  618. 
Protoelastose,  596. 
Protones,  589. 
Prussian  blue,203,  229. 
Pseudo  aconitin,  569. 

conhydrin,  549. 

globulin,  652. 

hiemoglobin,  662. 

morphin,  563. 

mucin,  594. 

nitrols,  376. 

nucleins,  586. 

pelletierin,  548,  549. 

pepsin,  609,  611. 

urea,  389,  406. 
Psychrometer,  150. 

PtomaXns,  383,  385.  476,  518,  519,  670,  582.* 
Ptyalin,  607,  619,  631,  642. 
Pulegone,  491. 
Purin,  528. 

bases,  531. 

compounds,  522. 

group,  522,  527. 
Purpurin,  500. 
Pus,  693. 

Putrefaction,  581,  646. 
Putrescin,  886,  417,  581,  617,  758. 
Pyoktanins,  506. 
Pyrazin,  516,  520,  621. 
Pyrazoles,  612,  514. 
Pyrazolin,  512. 
Pyrazolons,  512. 
Pyridiazin,  520,  521. 

Pyridin,  301,  4.3:),  507,  508,  509,  616,  818^ 
523,  545. 

alkaloids,  548. 

bases,  510,  617,  558. 

homologues,  518. 
Pyridylpvrrole,  545. 
Pyrimidi'n,  520,  621,  523. 

derivatives,  522. 
Pyrites,  138,  144,  169,  197,  199. 

copper,  250. 
Pyrocatechin,  448. 
Pyrocatechol,  447,  448,  647. 
Pvrocomane,  516. 
Pyrodin,  486. 
Pyrogallol,  460,  461,  467. 
Pyrolusite,  195,  196. 


814 


INDEX 


Pyrone,  516,  517. 
PyroxAin,  321. 
Pyroxylin,  323. 

soluble,  323. 
Pyrrazoles,  511. 

Pyrrole,  507,  508,  509,  610,  512,  517,  664. 
Pyrrolidin,  511. 

alkaloids,  548. 

piperidin  alkaloids,  548,  162. 

pyridin  alkaloids,  548,  661. 
Pyrrolidone,  511. 
Pyrrolin,  511. 
Pyrromonazoles,  6 IS,  514. 

Quartemary  ammoniom   oompomidSy  379, 
382,  383,  384. 

hydroxide,  377. 
Quercite,  489. 
Quicklime,  235. 
Quina  red,  462. 
Quinicin,  558. 
Quinidin,  556,  558. 
QuiniD,  519,  543,  666,  650. 

hydrosulfate,  557. 

sulfate,  557. 
Quluite,  489. 
Quinol,  447,  449,  729. 
Quinolin,  474,  478,  507,  519,  638,  648,  558. 

alkaloids,  548,  666. 

bases,  543. 

horaologues,  544. 
QulDone,  449,  450,  462. 

dioxim,  452. 
QuiDones,  461,472,499. 
Quinoxim,  473. 

Radicals,  84,  263. 

Radium,  55,  102,  103. 

Raffinose,  319,  602. 

Reactiou,  01  (see  Process,  Reagent,  Test). 

velocity  of,  90. 
Reactions,  endothermic,  97. 

exothermic,  97. 

reversible,  89. 
Reagrent,  Blum's,  738. 

Boas',  621. 

DeVries',  548. 

Esbach's,  738. 

Frohde's,  563. 

Gunzbur^'s,  621. 

Krii^er-Wolflf,  530. 

Marq Ills',  564. 

Mayer's,  548. 

MiUoirs,  578. 

Nessler's,  151. 

Olivers,  737. 

Riegler's,  737. 

Roberts',  736. 

Ro.'h's,  737. 

Schiff'a.  .326,  506. 

SoniKiischein's,  548. 

Spietrler's.  737. 

Stoke «<  ,  659. 

Strvzow.^ki's,  664. 

Tjuirefs,  7:i7. 

To|)f«  r's,  621. 

rtTf'hii.nin's,  623. 
Realtrar.  174. 
Reuiiimir's  scale,  22. 
Receptors.  073,  674,  675. 
Reduction,  108. 
Refraction,  index  of,  34. 


Rennin,  617. 
Residues,  84. 
Resins,  493. 
Resistance,  42,  45. 
Resistivity,  42. 
Re8orcinol„447,  448,  457. 

phthftlein,  451.  * 

Respiration,  686. 

changes  of  air  in,  686. 

tissue,  691. 
Respiratory  quotient,  687. 
Reticnlin,  583,  597. 
Reversible  reactions,  89. 
Rbamnose,  311. 
Rhigolene,  276. 
Rhodinol,  427. 
Rhodium,  213. 
Ribose,  311. 
Ricin,  572. 
Roburite,  471. 
Rochelle  salt,  227. 
Rosanilins,  474,  476,  503,  60i. 
Rosin,  488. 
Rouge,  198. 
Rubidium,  215,  230. 
Ruby,  246. 
Rufol,  499. 
Ruthenium,  213. 

Sabadillin,  570. 

Saccbarates,  311,  315,  318. 

Saccharin,  470. 

Saccharobioses,  309,  816. 

Saccharomyces,  326,  327,  600,  002,  603. 

Saccharose,  816,  600,  602,  643,  644,  681. 

Saccharotrioses,  309. 

Saffranins,  520. 

Saffrol,  450. 

Sal  ammoniac,  233. 

Salacetol,  459. 

SalieratuR,  226. 

Salicin,  453,  454,  459,  467. 

Salicvl  hydrid,  454. 

Salicylal,  454. 

Salig:eniu,  453,  468. 

Salipyrin,  514. 

Saliva,  606. 

Salmin,  589. 

Salmon,  588. 

Salol.  444,  469,  625. 

Salt.  217. 

of  Saturn,  206. 

of  sorrel,  226. 

rock,  217. 
Saltinjf  out,  576. 
Saltpeter,  223. 

Chile,  218. 

cubic,  218. 
Salts.  63,  05. 

acid,  66,  83. 

basic,  66,  83. 

double,  83. 

haloid,  66. 
Samarium,  55,  102,  103. 
Sandanw^h,  174. 
Saponification,  359. 
Sapphire.  246. 
Saprin,  380. 

Sarcosin,  390,  403,  414,  516. 
Sarkin,  533. 

Saturated  compounds,  273. 
Scandium,  55,  102,  103,  245. 


INDEX 


816 


Scheele's  green,  252. 

Scbweinfurth  green,  262. 

Scombron,  588,  589. 

Scopolamin.  553,  666. 

Secalia,  381. 

Secretin,  626. 

Seidlits  salt,  241. 

Seleuazoles,  511. 

Selenite,  237. 

Selenium,  147. 

Seleninonasole,  512. 

Sericin,  420,  697. 

Series,  electrochemical,  62t 

Serin,  420,  579,  580,  596. 

Serines,  653. 

Serum  albumin,  582,  668,  733. 

carbohydrates  of,  654. 

fats  of,  654. 

globulin,  582,  668,  733,  738. 

salts  of,  655. 
Siemens*  unit,  46. 
Silex.  191. 
Silicates,  191. 
Silicibromoform,  191. 
Silicichloroform,  191. 
Silicium,  190. 
Silicon,  188,  190. 

carbid,  161. 

cblorid,  191. 
Silver,  215,  280. 

acetylid,  425. 

bromid,  231. 

chlorid,  231. 

cyanid,  231. 

fulminate,  396. 

german,  249. 

monoxid,  231. 

nitrate,  231. 

oxalate,  301. 

oxidH,  230. 

thiocyanate,  432. 
Sincalin,  383. 
Skatole,  540,  641,  579,  580,  681,  697,  614, 

646. 
Skatosin,  617,  681. 
Skatoxyl,  646. 
Soaps,  429. 
Soap-stone,  240. 
.Soda,  220. 

bakiug,  221,  227. 

cauHtic,  217. 

washing,  220. 
Sodium,  215,  216. 

acetate,  220. 

acetanilid,  476. 

acetylid,  425. 

aluminate,  247. 

arsenates,  219. 

arseuites,  175,  219. 

bensoyiacetate,  525 

bicarbonate,  221. 

borate.  219. 

bromid,  217. 

carbonates,  220. 

chlorate,  220. 

chlorid.  217,  576. 

dioxid.  216. 

ethylate,  361,  532. 

ethylthiosulfate,  373. 

glycocholate,  636. 

group,  215. 


Sodium,  hydroxid,  217. 

hypochlorite,  220. 

hyposulflte,  218. 

iodid,  217. 

manganate,  220. 

metaphosphate,  219. 

methyl,  329. 

monoxid,  216. 

nitrate.  218. 

nitroprussid,  399. 

oxids,  216. 

phenate,  458,  459. 

phenylhydrazin,  484. 

phenylsulfid.  444. 

phosphates,  219. 

pyroborate,  219. 

pyrophosphate,  219. 

sesquicarbonate,  221. 

silicates,  218. 

sulfates,  218,  576. 

sulfite,  218. 

taurocholate,  636. 

thiosulfate,  218. 

tungstate,  192. 

urates,  531. 
Solanidin,  468. 
Solanin,  468. 
Solute,  27. 
Solution— Solutions,  27. 

dilute,  28. 

heat  of,  98. 

ideal,  28. 

normal,  66. 

pressure,  70. 

saturated,  28. 

solid,  51. 

supersaturated,  28. 

standard,  65. 
Solubilities,  776. 
Solvay  process,  221. 
Solvent,  27. 
Somnal,  402. 
Sorbinose,  311,  315. 
Sorbite,  298. 
Sorbitol,  298. 
Space  isomerism,  311. 
Spasmotoxin,  572. 
Specific  conductance,  41. 

heat,  33. 

resistance,  41. 

rotary  power,  38. 

volume,  10. 

weight,  10. 
Spectroscopy,  34,  36. 
Spermaceti,  363 
Spermin,  387. 
Spirit,  methylated,  287. 

potatoe,  292. 

pyroacetic,  307. 

pyroxylic,  286,  329. 
Spirits,  288,  291. 
Spongin.  583.  597. 
Stable  substances,  87. 
Stannates,  212. 
Stannic  chlorid,  213. 

oxid,  212. 
Stannous  chlorid,  212. 

oxid,  212. 
Starch,  287,  319,  820,  642,644. 

animal,  321. 

cellulose,  321. 

hydrated.  320. 


816 


INDEX 


Starch,  iodid,  321. 

paste,  320. 

solable,  321,  322. 
States  of  matter,  12. 
Stearoptenes,  438. 
SteapsTn,  627,  6S1. 
Steel,  197. 

StensobUin,  637,  6^,  648. 
Stereorin,  642. 
Stereochemistry,  312. 
Stereoisomerism,  811,  600,  673. 
Stethol,  363. 
Stibamin,  183. 
Stibins,  4^2. 
Btibonia,  183. 
StUbene,  502,  503. 
Stoichiometry,  78. 
Stomach  contents,  620. 

function  of,  609. 
Strength,  75. 
Strontianite,  238. 
Strontinm,  235,  S89. 
Strychnidin,  560. 
Strychnin,  559. 

Strychnos  alkaloids,  648,  889. 
Storin,  588. 
Styraeol,  448. 
Styrolene,  442. 
Suberone.  552. 
Snblimate,  corrosive,  267. 
Sublimation,  32. 
Snbstitution,  269. 
Suceinimid,  403,  408. 
Snccns  entericus,  632. 

pylorieus,  608. 
Snorase,  608,  632. 
Sncrates,  318. 
Sngar,  beet,  316  317. 

burnt,  317. 

candy,  317. 

cane,  316. 

diabetic,  314. 

fruit,  315. 

gelatin,  413. 

grape,  314. 

liver,  314. 

maple,  316,  317. 

milk.  318. 

of  lead,  206. 

invert,  316. 

raw,  317. 
Sulfates,  146. 
Sulfethylates,  359. 
SulfldM,  141,  371. 
Sulfites,  144. 
Sulfocarbolates,  470. 
Sulfochlorids,  469. 
Sulfonal,  374,  641. 
Sulfonation,  469. 
Sulfones,  370.  372,  469. 

of  mercaptols,  373. 

of  thioaldehydes,  372. 
Sulfnryl  chlorid,  143. 
Sulfovinates,  359. 
Sulfoxi«ls,  370,  372. 
Sulfur,    38. 

bronii<l  142. 

chlorid.  142. 

dioxid,  142. 

flowers  of,  138. 

group,  138. 

iodid,  142. 


Sulfur,  loosely  combined,  880L 

ozlds,  143. 

precipitated,  138. 

roU,  138. 

niby,  174. 

trioxid,  143. 
Sulfnrelds,  474. 
Soltones,  498. 
Superfusion,  29. 
Superphosphate,  287. 
Sylvestrene,  488. 
Symbols,  60. 
Synalbumose,  614. 
Synthesis,  62, 115,  262,  699. 
Syntonin,  590,  624. 

Talc,  240. 

Talose,  311. 

Tanacetone,  491. 

Tannins,  461. 

Tantalinm,  55, 101, 108, 191, 198. 

Tartar,  cream  of,  345. 

crude,  226. 

emetic,  227. 

salt  of,  225. 
Tartronylurea,  527. 
Tata-albumen,  584,  590. 
Taurin,  372,  4S1,  422,  432,  634,  636,  639» 

640.  680,  730. 
TaurocyniLamirj,  AH. 
Tauroglycopy^itijuaiti,  iSl, 
T^irbitianii*^  cryaials,  664. 
Tellurimn,  147= 
Temperatiin?,  2L 

ahsoItJte*  24. 

eritical,  29.  30, 

^tandarrj,  24, 
Tension,  'dO, 
Terbitim,  55,  102,  im. 
TerpiLDH,  487* 

Terpene  nitrosochlorid,  487. 
Terpenes,  486. 
Terpin,  488. 

hydrate,  490,  491. 
Terpinene,  488. 
Terpineols,  488. 
Terpinogens,  425. 
Terpinolene,  487. 
Terplns,  490. 
Terra  alba,  237. 
Test,  (Process,  Reaction) 

Adamkiewicz,  540,  678,  688,  592,  596, 
613. 

Alm^n,  325. 

Arnold,  755. 

Baeyer,  325. 

Barfoed,  324. 

Baumann,  323. 

Berg,  326. 

biuret,  407,  416,  678,  586,  587,  588,  589, 
592,  596,  613,  615,  616,  617,  627,  628, 
629,  630. 

Boettger,  325. 

Conradi,  326. 

Denigfes,  479. 

Ehrlich,  743. 

Ewald,  625. 

Fehling,  324.  749. 

fermentation,  326,  749. 

ferrocyanid.  736. 

Fischer,  325. 

Fresenius,  &  von  Babo,  182. 


INDEX 


817 


Test,  furfarole,  635. 
Gallois,  489. 
Gerhardt,  755. 
GmeliD,  687,  649,  742. 
Gmelin-Rosenbaeh,  742. 
guaiac,  741. 

Hammarsten,  687,  742. 
heat  and  nitric  acid,  73F 
Heller,  735,  741,  743. 
Hoffman,  479. 
Hofmeister,  415. 
Hoppe-Seyler,  326. 
Huppert,  637. 
Husemaun,  564. 
indophenol,  475,  477. 
Jaff6,  544. 
Knapp,  325. 
Kossel,  684,  536. 
Legal,  755. 
Lieben,  755. 
Lieben-Gunning,  755. 
Liebermann,  578. 
Marsh,  180. 
Millon,  678,  586,  588,  589,  592,  595,  696, 

615,  616.  617. 

Moliscb,   828,   679,   581,  613,  614,  615, 

616,  617. 
Mulder-Neubaner,  886,  642. 
murexid,  680,  639. 
Nessler,  161,  623. 
Neumann-Wender,  325. 
Nylander,  8S6,  749. 
ObermUller,  639. 

Pavy,  756. 

Pellagri,  564. 

Penzold,  756. 

Pettenkofer,  323,  510,  686,  649,  742. 

pheuylhydrazin,  826,  485,  750. 

phloroglucin-yanillin,  621. 

pine-8having,  446,  466,   609,  610,  640, 
543. 

Pirla,  479. 

precipitin,  672. 

Qairini,  325. 

ileinsch,  178. 

resorcin-sugar,  621. 

Reynold,  756. 

Riegler,  325. 

Rosenbach,  730. 

Salkowski,  639. 

Scherer,  415,  479,  489. 

Schiff,  323,  509,  639. 

Seliwnaoff,  826,  749. 

Smith,  743. 

Tiechmann,  741. 

ToUens.  828,  698. 

TOpfer,  622. 

trichloracetic  acid,  737. 

Trommer,  324. 

Villiers-PayoUe,  326. 

ViUli,  554. 

Vogel,  325. 

Wiedel,  516,  624, 526, 527,  633, 634,  535, 
536. 

Widal,  672. 

xantbin,  688,  535. 

xanthoproteic,  678,  588,  692,   696,  596, 
613,  615. 
Tetanin,  5?2. 
Tetanotoxin,  572. 
Tetra  bromanilin,  475. 

glycylglycin,  416. 

52 


Tetra  hydrobenzenes,  434,  486. 

hydrodiphenyl,  502. 

hydroglyoxalin,  514. 

hydronaphthols,  498. 

hydronaphthylamin,  501. 

hydropyridins,  519. 

hydropyrimidins,  523. 

hydropyrrole,  511. 

hydroquinolins,  544. 

hydrostrychnin,  560. 

ketohexahydropyrimidin,  527. 

ketones,  308. 

methylammonium  hydroxid,  381. 

methylbenzenes,  441. 

methyldiamidodiphenylmethane,  503. 

methylenediamin,  386,  417,  511. 

methyleneimin,  511. 
Tetraramonium  iodids,  379. 
Tetronal,  374. 
Tetrapeptids,  416. 
Tetraphenylpyrimidins,  545. 
Tetraphenylsilicon,  502. 
Tetrazin,  508. 
Tetrazoles,  511,  512. 
Tetrethylammoniuni  hydroxid,  382. 
Tetriodopyrrole,  511. 
Tetroses,  309,  310. 
Thallin,  544. 

Thallium,  55,  102,  103,  236. 
Thebain,  562,  666,  567. 
Thebaol,  567. 
Thein,  533. 

Theobromin,  688,  546. 
Theophyllin,  532.  533. 
Theory,  atomic,  52. 

Ehrlich*8  672. 

molecular,  52. 

side-chain,  673. 
Therm,  22. 
Thermal  capacity,  23. 

unit,  22. 
Therochemistry,  97. 
Thermolabile  substances,  671. 
Thermometers,  21. 
Thermostable  substances,  671. 
Thetin.  508. 
Thialdin,  303. 
Thiazins,  520. 
Thio  acetals,  373. 

acids,  370,  374. 

albumose,  615,  618. 

alcohols,  370,  871,  372. 
.    aldehydes,  305,  370,  872. 

anhydrids,  141,  374. 

antimonates,  186. 

antimonites,  185. 

arsenates,  174. 

azoles,  511. 

bases,  64. 
Thiocol,  448. 
Thio  cyanates,  397. 

ethers,  370,  371. 

ethylates,  372. 

glycols,  372. 

ketones,  370. 

monazoles,  512. 
Thionin,  520. 
Thionyl  chlorid.  398. 
Tbiophene,  507,  508,  509,  610. 
Thiophenol,  469. 
Thiourea,  405,  406. 
Thorium,  55,  102,  103. 


818 


INDEX 


Thrombin,  0S1»  MS  MS. 
Thromboiin«  MO. 
Thniane,  491. 
Thmium,  56, 102, 103. 
Thymentf,  447. 
Thymin,  523,  014,  526»  608. 
Thymol,  447. 
Tin,  211,  212. 

ehlorids,  212. 

erystelt,  212. 

gronp,  211. 

hydniM,  212. 

oxidB,  212. 
Tinitone,  212. 
Tineal,  219. 
Tinetaret,  288. 
Tltaniiim,  65,  102, 103. 
ToUme,  502,  503. 
Toloene,  441»  456,  460,  47L 

snifonie  ehlorids,  400. 
Toloidins,  473,  474. 
Tohiol,  441. 
Tolnyl  bensene,  501. 

dimethylpyraiolon,  514. 
Tolnylene,  503« 
Tolypyrin,  514. 
Topai,  245,  246. 
Toiiudbamins,  673,  669, 678. 
Todioology,  acids,  138. 

•eonite,  569. 

ammoDift,  234. 

antimony.  186. 

arsenie,  175. 

atropin,  554. 

barinm,  240. 

bismath,  211. 

earbolie  aeid,  446. 

earbon  diozld,  356. 

earbon  disulfld,  376. 

earbon  monozid,  353. 

ehloral,  304. 

ehloroform,  279. 

copper,  253. 

cyanide,  392. 

hydrogen  snifld,  140, 

illuminating  gas,  353. 

lead,  207. 

mercury,  260. 

nicotin,  551. 

nitric  acid,  159. 

nitrogen  tetroxid,  155. 

opium,  507. 

oxalic  acid,  336. 

phenol,  445. 

phosphorus,  161. 

potassium,  229. 

silver,  231. 

strychnin,  561. 

sulfuric  acid,  147. 

*inc.  244. 
Toxins,  570,  578.  669,  673,  674. 
Toxophores,  673,  674. 
Transposition,  62. 
Transterpene,  490. 
Transudates,  692,  693. 
Triacetin,  296. 
Triacetamid,  409. 
Triamido  azobenzene,  476. 

benzenes,  476. 

triphenylmethanes,  505. 
Triamids,  309. 
Triamins,  377,  389. 


Trlasins,  636. 
Trlaaolea,  511,  512. 
Tribiomhydrin,  338. 
Tribrommethane,  880. 
TribromoanthraqolnoiM,  Ml 
Tribromophenol,  446. 
Tribo^yrin,366. 
Trieaprln,  365. 
Tiieaproin,  365. 
Trieaprylln,  366. 
Triohlor  aeetal,  303. 

■eetrlehlorid,  308. 

aldehyde,  303. 

aniUns,  475. 

bataldehyde,  806. 

methane,  278. 
Trioyanhydrin,  338. 
Trieyanogen  ehlorid,  880,  687. 
Triformaldehyde,  3^. 
Triformozin,  410. 
Tryglyeerids,  296. 
TrigoneUln,  618,  548. 
Trliodomethane,  280. 
Triketcmes.  306. 

TriketohezahydropyrhBldln,  696,  887. 
Trikeitopnrin,  588. 
TrlkefeotetrahydrogtyoKalln,  616. 
Trimargarin,  366. 
Trimethylamin.  381,  383,  384. 
Trimethylbenaenes,  441, 448. 
Trimethylethylene,  426. 
Trimethylene.  434. 

bromid,  434,  658. 

eyanid,  552. 

dlamin,  386. 

imid,  508. 

Olid,  508. 

triaiilfone,  873. 
Trimethylia,  381. 

Trimethylozethylamm<nii«m  hydfrndd,  883. 
Trimethylozethylideneammonimnhydroxid, 

Trimethyluracil,  524. 

Trimetbylvinylammonium  h^drozid,  384. 

Trlmethylxanthin,  533. 

Trinitranilin,  475. 

Trinitrophenols,  442,  472. 

Triolein.  366. 

Triola,  295. 

Trional,  374. 

Trioses,  309,  310. 

Trioxyanthrnqninone,  500. 

Trioxycyanidin,  396,  537. 

Trioxymethylanthraquinone,  600. 

Trioxymethylene,  361. 

Tripalmitin,  365. 

Tripeptids,  416. 

Triphenylbenzene,  501. 

Triphenylcyanhydrin,  537. 

Triple  phosphate,  241,  706. 

point,  94. 
Trisaccharids,  309,  319. 
Tristearin,  366. 
Trithioacetaldebyde,  305. 
Trithioacetone,  373. 
Trithioformaldehyde,  373. 
Tropacocain,  548,  552. 
Tropan,  562,  553. 

alkaloids.  552. 
Tropelns,  553.  565. 
Tropeolins.  498. 
Tropidin,  358,  553,  555. 


INDEX 


819 


Tropin.  R19.  662,  553,  664,  555. 
atropate,  554. 
tropate,  553. 
TruzniiDR,  548,  552. 
Trypsin,  627,  628,  646. 
Trypsino^ren,  627. 
Tryptophane.  640,  544,  678,  680,  681,  582, 

58!).  012,  614,  629,  632,  646. 
Tungsten,  192. 
Turn  bull '8  blue,  203,  229. 
Tumor's  yellow,  206. 
Turpentine,  488. 
Tutty,  243. 
Tyrosin,  416,  478.  578.  579,  680,  681,  589, 

595.  596,  mi,  614,  617,  626,  631,  633, 

646,  647,  757,  758,  763. 

Unit,  Siemens',  46. 
Units,  C.  G.  8..  46. 

fundamental,  7. 
Uracil,  628,  525,  693. 

bases,  592,  631. 

compounds,  522. 

fcroup,  522,  523. 
Uralium,  402. 
Uranils,  526. 
Uranium,  203. 
Uranyl,  203. 

Urea,  389,  398,  408,  407,  408,  413,  418,  515, 
523,  524,  526,  629,  530,  634,  655,  685, 
686,  709,  710,  711,  712,  713,  714,  721. 

chlorids,  402,  403,  406,  477. 

nitrate,  405. 

oxalate,  405. 
Ureas,  compound,  397,  406. 
Ureases,  606. 
Urelds,  406,  515. 

cyclic,  522. 

diacidyl,  407. 

mixed,  407. 

monacidyl,  406. 
Ureium  nitrate,  378. 
Urethans,  402,  403. 
Urine,  694. 

abnormal  eonstituentt  in,  733. 

pigments  in,  743. 

acetone  in,  763,  755. 

acetylacetic  acid  in,  763,  755. 

albumin  in,  733. 

albumoses  in,  736,  737,  738,  739. 

alkaline  phosphates  in,  704. 

allantoTn  In,  725. 

amido  acids  in,  756. 

ammonia  in,  709,  710,  713,  763. 

biliary  constituents  in,  742. 

blood  in,  741. 

chlorids  in,  699,  700. 

chondroUin  sulfates  in,  740. 

chromogens  of,  725. 

collection  of  samples  of,  714. 

composition  of,  699. 

concentration  of,  698,  699. 

conjugate  glucuronatet  in,  732,  750. 

consistency  of,  694. 

creatin  in,  720. 

ereatinin  in,  709,  710,  718,  719,  749. 

cryoscopy  of,  698. 

cystin  in,  757. 

dlphenols  in,  729. 

earthy  phosphates  in,  704. 

Ebrlich's  dlaso  reaction  of,  743. 

electric  conductivity  of,  699. 


Urino,  ondosronons  uric  ncid  in,  721. 
ester  sulfates  in,  702,  703,  728. 
exogenous  uric  acid  in,  721. 
fermentation  of,  601. 
freezing  point  of,  698. 
fructose  in,  749,  752. 
glucose  in,  744,  745,  749,  750  (tee  Gly- 
cosuria), 
glycocoll  in,  756,  757. 
glycosurates  in,  713. 
glyoxylic  acid  in,  713. 
bfematoporphyrin  in,  741. 
Lapnioglobin  in,  741. 
hippuric  acid  in,  724. 
histon  in,  740. 
indican  in.  729. 
indoxyl  sulfates  in,  729. 
inosite  in,  753. 
lactose  in,  752. 
IsDVulose  in,  749,  752. 
laiose  In,  752. 
leucin  in,  757. 
maltose  In,  749,  750,  752. 
metallic  elements  In,  706. 
mineral  constituents  of,  700. 
mucin  in.  736,  740. 
neutral  sulfur  in,  702,  703,  727,  730. 
nitrogen  distribution  In,  706,  708,  709, 

710. 
normal  organic  constituents  of,  706. 
nucleoproteids  in,  740. 
odor  of,  696. 

osmotic  pressure  of,  698,  699. 
oxalates  In,  731. 
oxaluric  acid  in,  725. 
oxybutyric  acid  in,  753,  754. 
pentoses  in,  753. 
phenols  in,  728. 
phosphates  in,  703. 
physical  characters  of,  694. 
pigments  of,  725. 
polarisation  of.  749,  750. 
proteins  in,  733. 
quantitative  determinations  in,  713. 

of  albumin,  738. 

of  ammonia,  711. 

of  chlorids,  701. 

of  ereatinin,  719. 

of  earthy  phosphates,  706. 

of  ester  sulfates,  702. 

of  globulin.  738. 

of  indican,  719. 

of  mineral  sulfur,  702. 

of  oxalic  acid,  711. 

of  phosphates,  705. 

of  total  nitrogen,  707. 

of  total  sulfates,  702. 

of  total  sulfur,  702. 

of  urea,  714. 

of  uric  acid,  723,  724. 
quantity  of,  695. 
reaction  of.  696. 
reducing  substances  In,  749. 
serum  albumin  in,  733,  734,  735,  736,  737. 
serum  globulin  in,  733,  734,  786,  736, 

737.  738. 
skatoxylsulfates  in,  730. 
specific  gravity  of,  695. 
sulfates  in,  702,  703. 
sulfur  in,  703,  727. 
thiocvanate  in,  731. 
toxicity  of,  733. 


820 


INDEX 


Urine,  tyrosln  In,  757. 

undetermined  nitrogen  of,  708,  709,  710. 

urea  in,  709,  710,  711,  714. 

uric  acid  in,  709,  910,  712,  720,  721,  722, 
749. 

urobilinogen  in,  725. 

urochrom  in,  725. 

uroerythrin  in,  725,  727 

urohiematin  in,  730. 

uroxantbin  in,  729. 

xantbin  bases  in,  712,  721,  724.^ 
Urinary  mucoid,  740. 
Urobilin,  637,  642,  664,  665,  725,  726. 
Urobilinogen,  725,  726. 
Urobilinoids,  725. 
Urochrom,  725. 
Uroerythrin,  725,  727. 
Urohsmatin,  730. 
Urorosein,  743. 
Urostealiths,  759. 
Urotropin,  409. 
Uroxantbin,  541,  729. 

Valence,  59. 
Valerene,  425. 
Valerolactam,  413. 
Vanadium,  55,  101,  103,  191. 
Vanillin,  448,  464,  466. 
Vapor.  29.  30. 

pressure,  50. 

saturated,  31. 

tension.  31. 

unsaturated,  30,  49. 
Vaporization,  29. 
Varecb,  135. 
Vaseline,  277. 
Vegetable  albumins,  584. 

globulins,  582,  584. 
Velocity,  4.  5. 

constant,  91. 

of  reaction,  90. 
Veratrin.  579. 
Veratrol,  448,  449. 
Verdigris,  25.1. 
V^ermi'.ion,  2r»r». 

antimony,  186. 
Veronal,  52(j. 
Verona  vellow,  206. 
Vichy  salt,  221. 
Vinegar,  320. 

wood,  .T29. 
Vinyl,  426. 

aniin,  382,  384,  432. 

hroniid,  424,  426. 

chlorid,  426. 

pvridin,  519. 
Vitelfinoses,  613. 
Vitellins,  582. 
Vitriol,  blue,  251. 

green,  200. 

oil  of,  144. 

white.  244. 
Volt,  46. 

Volt,  ampere   46. 
Voltage,  41. 
Voltameter,  45. 
Voltmeter,  46. 
Volume,  specific,  10. 

Water,  113. 

baryta,  239. 
lime,  2.36. 


Water,  maximum  density  of,  23,  50. 

of  constitution,  115. 

of  crystallization,  17,  113,  115. 

oxygenated,  123. 

soda,  354. 
Waters,  natural,  116. 

chlorids  in,  117. 

hardness  of,  118. 

impurities  in,  117. 

mineral,  121. 

organic  matters  in,  118. 

poisonous  metals  in,  119. 

purification  of,  121. 

solids  in,  117. 
Watt,  8,  46. 
Wax,  363. 
Weight,  5,  6. 

atomic,  54. 

equivalent,  60. 

molecular,  56,  267. 

specific,  10. 
Weights,  778. 
Whey,  617. 

albumin,  617, 
White  of  egg,  584. 

lead,  2U4,  207. 

precipitate,  258. 
Wines,  290. 
Witherite,  239. 
Witte's  peptone,  613. 
Work,  8,  21,  46. 
Wort,  287. 

Xantbin.  530,  532,  533,  535. 

bases,  528,  530  581,  592,  712,  721,  724. 
Xanthocreatinin,  390. 
Xanthone,  459. 
Xanthones,  539. 
Xenols,  446 

Xenon,  55.  101,  103,  125. 
Xylene,  459. 

glycols,  453. 
Xylenes,  441. 
Xylenols,  446. 
Xvlidins,  474. 
Xylodin,  321. 
Xvlols,  441. 
Xylose,  811.593. 

Yeast,  600,  602, 
Yolk,  516. 

platelets,  586. 
Ytterbium,  55,  102,  103. 
Yttrium,  55,  102,  103. 

Zein,  587. 

Zinc.  240,  242,  634. 

alkyls,  307,  578. 

butter  of,  243. 

chlorid.  243,  244. 

ethid,  375. 

ethvl.  375. 

hydroxid,  243. 

met  hid,  375. 

m ethvl.  375,  455. 

oxid,"243. 

sulfate,  244,  576. 
Zirconia,  211. 

Zirconium,  55,  102,  103,  21L 
Zymase,  602,  603. 
Zymogens,  604. 
Zymophores,  674. 


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