Skip to main content

Full text of "The American journal of science"

See other formats 


<= 
“8 
J 
a 
ee 
Spey 
~ 


it 
Ytete? 


“att 
*t 


+ 

. 

2% 
Py 


otelate 


reevGarars C4 VERE TOTS 


tad ye HW BEN 
4% ' wpe ven ce beet taewa ag! ae pe eee eae 
envee re weet tat od bared a WC Wa MC eR 
< 4 soe rave pee Pee ek eee ea VE ae be ay sea 
we we oe ‘ Parear er reat Wa WO 
wf TE eee RO OC ee A BO 
tHe oe Pera e ae terest Pearverrar ar eerie Ye Det er ee P * La 
forego? Preparer vad QVeypryeryy ces pgp e er Tae Fos fe seve haa f Ada dy tad ORR ot 
bes re weer o ecgeek ae Re Sol We ee ig ee ee we eC oe 4 % io Wee rear Ra 9h 
repareuy are Lanna ts eet ee ee ly bee hoe co ec eee 
ot ovteueed 8 wae vr TR ED RT She a) ’ ee Piers WT Ch eat c 
fo what Cpe Fg at row fp eae es OW got VS oe ee * 
eht tee ger yp les Cerne at eee ee sy Rohe cum PAU CAR A eh 
Ce Pee or er ee ee Vp eee g ) oa Oe Se ae 
as ’ a tr RTA NOE a eR ROCA LU a8 Lee dine Cr Pee 
Freeda wpe eer ets Re Tee swat a eer”? ET Ag we, ceded Cop fsa rhe bid hs Gal 
CAEL SOLS EON Le Parad WC OO NA Pie 
wh) Bese Sas, Se Led wad Fie p, an ee a: 


pur teagan FOP ee hoes 
? yr eee . son ebal wee 
2% oe Ps whew tw? Ee BAT OE bP kt tA) a 
’ 


Pas at en See ig pi rpeaens 
: : y tT Sit tetera OATS T EMIT att le ty bu WHY Me ray 


ee er ie ehh mens 


sperhewpavh yd 
te wp lp eat + Py A OL Bee FRCL Bt et a te 
Pr ee ee ee oe he A Le ree, rae 
vee eur ewapere pou porvueey ANOS OO ORLA Seen sear i 
4 evewee ‘ RUN eM i Rk he pe MAA ARH Pekan th Seo 
ree pe hore vee no eee eA pequy ” * i ee Oe SO Le ACCRA LS Ne 
' oe ys Prerariarie Westie Ae a A A ey ey ed Ee oeagi Wks cob: vie gem ti. 0 fia ea « 
Cee Urge oe EY TS VEG > 6 vebecegrast 4? TOE A AAAs wa ‘ 
‘ te Par a Os MD ape ye Cl eee | is bk A 
PA de * ye ee! TR PPE Dg dos peewee gt RP et HM oe Oe oO he wey ney 
. ' ) Pye} aust ptm et Pes eye pe Lhe OY Sy R11 OG BA Pe oe Ne Hype er boned vee 
ove yeu n COye Le OT RES at Peed Ow La et son erreas Oh Ae HA Aa tLe 
' vue 3 + } a ae ee ek ROL ea sn ae perme rath ey the rant 
1 S edd 8 1 u's ‘ ¥ : rao by ee bt b teteree y bd Rh, b eee 
ary nya Ce ‘ of Sow yo be ee ath elas 9 a ttatanie taza atheacare hea bee ee on 
i, bo Pune 4, 0g Ne ED 9 “4 Omit we Cee " Deal ii atta ah ‘ 
. 8 a ee ee ‘ , peeve 1 o ee alia \ 
eyoyale ' ‘sh? so atwe yer PEP Rey ree | 
‘ ' 14 t+ ’ ina BAAR Ck ee weet 4 ' 
pee aca hae fell . ' os yh oi dae e | CALA Re ‘ geht iy 
‘ yrene Chee ved Pee ee ey OP Ua et nee ene 
pret epeye ee ge dy rovrsbatyypreyd Arr tipped , ray. R aay We 
vie ty peruye "y RE aS ROR aru A ieie di Ne E Ba ee Ana LA Ra FP. 
Yoo ses pe day webby ore ie Ce ee eee Lb ‘ aie bowels 
i] ‘ 1) 1 Veyy tv yh Ve ye tae) & ’ 


© 4 “ . : 
yy . PRT RORIE IC 
74 ' OE ee 
4 wy tA EADS S| 
‘ ‘ ’ eves he 
\ oF 
tes pee 
4 Y>) 
' wee 
ae ‘ te pen 
yr yu ‘ a) eee oe he PN ee ee Eo pt 
‘ r) edkoeagade ee Pe doa +eey Cvs ey seve 
t ‘ eae yee Prey ed yt hye eae gs 
tary _iss eytp eee araty ee RO 
eee | sree eh e ee ge pa dh Suvrys ' 
a ce ad ! Palais TENS 
114 : Ky Pin eID 
~} 3 a 
' ‘ 
gs ony My 
‘ ace N 
Bly 
yy 


> eRe) . 
’ ab al wy deed 


i ah une’ 


oe 


y thy b 
OER 
ahh A Nun 


’ y : 

ea r baw 
ng da 
a en i 
et Daeg 


‘heats 


aN 


PPe aioe 
vy Peon een 
Pree rae 


ere etsy 
Ld “ys. 


Pay) Me aes 


ener “a ve ; 
are ae be be ral 
‘ “yates Kies 


duce Bh, By hi 
yi Ae gate’ # i ky. 
tis winnie YS 34, ahi Sal's, 
Pb ay. Fee Fae esi { Pen : 
hic 
Teed aed, in ied de 
af iF aie sinh ue Ee us 4 


ath 
nae ha ee aes 
1 


Le 
ai, Ay dares rey 4 Mei ests 


iat a ee he Perr 
* ” a deo 


doe 
ai Meer ta 


; . 
Rr aR Rates 
dod ed 
jedi Bebe d | 


q dobea kh ed woe COP eg aa 
PM be ata ons ye been bare) 
Vea heb Cee ed Fea a gd 
erro eee eee ee P 
Ve 23 wei de PPA SA 
Aerie mere ea Be Le 


S38 


‘ ee bal ot Wie 
ya bee a he Harr 
Fb rere a aie A pa! ie, tarp 

ORR ORR trails ot Me ot 


wide th, 

ti “te ay i 
Li 
awe 


oe UNE Ie POR Bee Fe 
errant ae ee ere re 


whe 
Bt CA I iat 
SAA tates 


ow ane 


I ileal Mal daw eR 

tok se ed ee er 
Prana Ue eee eee ae 
Ge ada bg oh ig hdd ae wae 


Oe UA dere 
eee 


SoG hl bos 8 
aw ‘ v-4 isae ‘ tedad bad Saad & ae ae NE 3 ‘ 
4% bon : a Pv hal ee ee ee Pe se ad ad Fea des wee 8 , f 
4:0. Bie >. tae thas eee Pee debe 8 for gest bhoe dd babe eid ad bd eet ie rated ‘sata oe 
Pn i ee eves ea ee DY dene 7 be a a DON sata ep iadiada : ne Werth Eee SOS Peon eee oe ay Ratan ” 
; ; : tie Ae Me Mare ara aa Pravastatin pie Boh Scant een he 
aver tee ‘ , auf . Prawns Wrenn eer er ee err ey a ere Hed a UK et We of we wae 
‘ ‘ ‘ ' rare adage t on eene ROR aR Pisin ay H 
se n +t ee mee) we th ae +e LN Ow Se Ba creme 
en sai rate ec ; Se eC eT gt Wh Xe Le rade mb she ast 
Bw niubie 4 rar aba Md RC NOL ma tale 2 ua CN 
: : : ae ve dg eta ls Gdaee wee Liat kr ty ob Lb Teo 
‘ dor am 8 . aa Db hae bb bee a? rere ee ree See 
. aes 4a a ee aev io Fo Uaen ‘ elt eevee i fide eae tbod 
‘4 jueecee w 8 ‘ pan ba bene bes eed 54 Dak ot Lead dasee OTe a aca aaa a! 
es al tana de adhered ae Fat bi blanwaae a a nid ao LA ‘ ied ts a Farina, cer tote 
is ‘ Sie LP ar acer Ter Ie a ae OC i ‘ iy “ay ne 
‘ : 4 ae eee ee ea ph ec bh ota Le ae tee eM wee ree Ie a Be Oe a oe 
to it ie oe chad oa V4 SoMa ERD ENE a RT ah OR fs Pe ie Lait 
a yom 4 ec ‘ ‘ ‘ 4: oo ae ~t ry pe tet hd bed tous Oo we EET a eS whan teas OG eedid bode <i ie 
‘ i -4 ia ' 4 @ . ath a Dab Vat Ce ee dave ade de el wd ‘ 
. ‘ 4 ‘ ” ‘ sides . » 4 ‘ aaeat bn deg OE ed Ae ead Boe gy oy 
at aoa ‘ co Perea re 4 pad (tuedtoat ad thew Agr 
at ae ma os, citi sted - SAA ned bok Dos oa 
or ‘ ‘4 ose siaeae ole vt ee aide ee the bog Le we 6s 
taonrd a iit se . pee bd Ga eb hb eee bas 
‘ 4 aed veob 6 Se ee ee 24d Gated weed 
F ’ Tere eee ee ee 
4 . oa . ’ to 8 aa ' Skee en ar vd bee tt eh Oa ed oe 
ou 7 ‘ at boetue 
AR : ; - fata eeadh a bed dd pia dd ond SH bdad oe 
oe ‘ ‘ . ‘ ‘ CRO PO Be PC RL a Ae ee re oe ee 
* . ' ‘ at Pee et) ee ee 
wai ‘ . sibs oa ‘ ‘ 406A ol EES 48 
Shea e Ub ho bre ha ee ae : 4 Pa ee . « iv taba aed aa 
’ . ‘ ar] ‘ aa ba ad bad hd Ag eT a 
ry ee ’ ee ee a Pe oe Ue cs 
ot ae sae 4 i DC Rae a ie eR PIE 
- Pa A ‘ Perens Par rere ek ee ee " 
: see hidbev es dh. Fhe ad added Roaddes eed bbe ea we wih a 
- pi 7 + ao te. Be ex a 2 fb Ca Oe bee et LO ie 


, 
. 
‘ 
: ' 
’ a 7 
ae 
| 
. 
s 
- 
“4 


THE 


AMERICAN © 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Campripce, 


PROFESSORS ADDISON E. VERRILL, HORACK L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor GEORGE F. BARKER, or PuiuapELputa, 
Proressor HENRY S. WILLIAMS, or Irwaca, 
Proressor JOSEPH S. AMES, or Battimore, 
Mr. J. S. DILLER, or Wasuincron. 


FOURTH SERIES 


VOL. XXVI_[WHOLE NUMBER, CLXXVI_] 


NEW HAVEN, CONNECTICUT. 
1908 


203484 


THE TUTTLE, MOREHOUSE & TAYLOR COMPANY, 
NEW HAVEN 


CONTENTS TO 'OLUME XXYVT. 


INTO ber Eb L. 
Page 


Art. I.—Emission of Electricity from the Induced Activity 
of Radium; by W. Duane 


Ii.—Ilvaite from Shasta County, Cal.; by B. Prescorr.... 14 
Ilf.—Mechanics of Igneous Intrusion (Third Paper) ; by 
RR = SO ee eee eS 17 


1V.—Rhinocerotide of the Lower Miocene ; by F. B. Loomis 51 
V.—Description of Tertiary Plants; by T. D. A. Cocx- 


SURED ~ oc A aga eg a ae el em 65 
VI.—Descriptions of Tertiary Insects; by T. D. A. Cocx- 
ERI 22 pees ee eee eee ich Ee ee Sian oe 69 
VII—New Fossil Elateride from Florissant; by H. F. : 
nee ee a Se eee ee 76 


VIII.—Estimation of Iron and Vanadium in the Presence of 
One Another ; by G. Epcar 79 


1X.—Estimation of Cerium in the Presence of the other Rare 
Earths by the action of Potassium Ferricyanide; by 
PeebereOwNING and H: KB. Parmer —. 22.0) 22 222 tee 83 


X.—Estimation of Chromium as Silver Chromate; by F. A. 
Pemeemeamor byte Won hs 6 Sku eo ee a eee EBD 


XI.—Standardization of the Fog Chamber by the aid of 
aomeons Klectron ; by C. Barus _....2 2... -2-2 2-22 87 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Volumetric Method for Chlorates, KNEcut: Atomic 
Weight of Radium, THorpz, 91.—Polyiodides of Potassium, Rubidium, 
and Caesium, Footr and CHALKER: Volumetric Method for Copper, 
JAMIESON: Thermodynamics of Technical Gas-Reactions, F. HABER, 92.— 
Search for Fluctuations in the Sun’s Thermal Radiation through their 
Influence on Terrestrial Temperature, S. NEwcomp, 93. 


Geology—Early Devonic History of New York and Eastern North America, 
J. M. CLARKE, 93.—Publications of the United States Geological Survey, 
95.—Maryland Geological Survey: Iowa Geological Survey, 97.—Wis- 
consin Geological and Natural History Survey: Geological Map of Cape 
of Good Hope, A. W. Rogers and A. L. pu Torr: Variations Périodiques 
des Glaciers, XIIme Rapport, 1906, Ep. BRUcKNER et E. Murer: Cera- 
topsia, J. B. HatcHeER, 98. 


Miscellaneous Scientific Intelligence—Harvard College Observatory : Publica- 
tions of the Allegheny Observatory of the Western University of Penn- 
sylvania: Carnegie Institution of Washington, 99.—Maryland Weather 
Service: Apodous Holothurians, H. L. CLarx: American Association for 
the Advancement of Science : International Catalogue of Periodicals, 100. 


Obituary—M. ALBERT LAPPARENT: Kari A. MOpius: M. Pierre J. A. 
BECHAMP: ROBERT CHALMERS: WILLIAM A. ANTHONY. 


1V . CONTENTS. 


Number 152. 


Page 
Art. XII.—R6le of Water in Tremolite and Other Minerals; 
by E:T. Aucenand J. K. Crumunt ____2......) 3a 
XII.—Quantitative Determination of the Radium Emana- 
tion in the Atmosphere ; by G. C. Asuman ....__---..- 119 
XIV.—Determination of Small Amounts of Barium in Rocks; 
by. dR. Wi LANGLEY 2.2250 ool 123 


XV.—Heat of Combination of Acidic Oxides with Sodium 
Oxide and Heat of Oxidation of Chromium ; by W. G. 
WERT RR edo .8 Gees atc, oo ee Sete Oa Papers || 2)/5) 


XVI.—Concerning Certain Organic Acids and Acid Anhy- 
drides as Standards in Alkalimetry and Acidimetry ; by — 
I. K; Pures and L. H. Weep 220002 0) 2 ao ee 


X VII.—Comparison between Succinic Acid, Arsenious Oxide 
and Silver Chloride as Standards in Lodimetry, Acidi- 
metry and Alkalimetry ; by I. K. Poenps and L. H. 


W BEDSE SU Se ee ea 143 
XVIII.—Orthoclase Twins of Unusual Habit; by W. He 
Forp and EK? W-; Truorson,.Jr, 222 22 eee eee 149 


XIX.—Palisade Diabase of New Jersey; by J. V. Lewis - _ 155 


XX.—New Horse from the Lower Miocene; by F. B. 
LOOMIS. 2 ois bie Si nips ete ee 


SCIENTIFIC INTELLIGENCE, 


Geology—Indisches Perm. und die permische Hiszeit, E. Koken, 165.—Geo- 
logical Survey of Western Australia, Bulletin 29: Illinois State Geological 
Survey: Map of Vesuvius, 166.—Pocket Handbook of Minerals, G. M. 
ButTLER, 167. 


Botany—Origin of a Land Flora, F. O. Bower, 167.—-Linnaeus, V. SURINGAR : 
Algenflora der Danziger Bucht ; ein Beitrag zur Kenntniss der Ostseeflora, 
LaKxowlrTz: Text-Book of Botany, 168. - 


CONTENTS. Vv 


Number 1538. 


Arr. XXI.—Retardation of “Alpha Rays” by Metal Foils, 
and its Variation with the Speed of the Alpha Particles; 
Pe). See aWORT ee. 2. eee ee. 2 eho 

XXIL—Notes on the Lower Paleozoic Rocks of Central 
Mew wrexice, by We 1. unm aie ee i Se 180 

XXIII.—Kaersutite from Linosa and Greenland; by H.S. 
WAsHINGTON; with Optical Studies by F. E. Wrieur.. 187 

XXIV.— Geology of the Isthmus of Panama; by KE. Hower 212 


Page 


SCIENTIFIC INTELLIGENCE. 


Geology—Geology of the Adirondack Magnetic Iron Ores, D. H. Newuanp: 
Geologishe Prinzipienfragen, E. REYER: Die Entstehung der Kontinente, 
der Vulkane und Gebirge, P. O. KOHLER, 238. — Geological Survey of 
Canada, A. P. Low: Geography and Geology of a Portion of Southwestern 
Wyoming, A. C. Veatou, 239.—Einfiihrung in die Paliontologie, G. Srern- 
MANN: Niagara Stromatoporvids: Occurrence of Hobocystis in ‘Ontario, 240. 

Miscellaneous Scientific Intelligence—Publications of the Japanese Earth- 
auake Investigation Committee, 240.—The Physical Basis of Civilization, 
T. W. Hetneman: General Physics, H. Crew, 241.—Die Insektenfamilie 
der Phasmiden, K. B. v. WaTTENWYL und J. REDTENBACHER, 242. 


SUPPLEMENT. Pane 
Arr. XX V.—On the Esterification of Malonic Acid ; by I. 
ier nenes and Hy W, TILLOTSON, JR)... 22 28 oy 248 
XXVI.—Concerning the Purification of Esters; by f. K. 
and M. A. Puenes and E. A. Eppy ___...-.....-.._. 253 
XX VII.— On the Conversion of Cyanacetic Hester to Malonic 
Mster; by | K. Purnes and EK, W. Tittotson, Jr. __. 257 


XXVIIL.— Researches on the Influence of Catalytic Agents 
in Kster Formation. On the Esterification of Cyana- 
-cetic Acid ; by L K. Puerrs and E. W. Tittotson, Jr. 264 
X XIX.—On the Preparation of Malonic Acid or its Ester 
from Monochloracetic Acid; by I. K. Puretrs and E. 
Pee OTS ONG OR ee, Se es ae 267 
XX X.—On the Preparation of Cyanacetic ‘Acid and its Ester 
from Monochloracetic Acid; by I. K. Paertps and E. 
BR PersUb Ne ON CI ce ek oe ee ae ah OTS 
XX XI.—Researches on the Influence of Catalytic Agents in 
Ester Formation. Hydrobromic Acid and Zine Bromide 
in the Formation of Ethyl Benzoate ; by I. K. and M. 
Meee and A Bppy ot 
XX XIIL—Researches on the Influence of Catalytic Agents 
_ in Ester Formation. The Effect of Certain Sulphates 
on Benzoic and Succinic Acids ; by I. K. Purtpes, H. E. 
Pp UM Aer OL DIN 28 eS 290 
XXXIII.—Researches on the Influence of Catalytic Agents 
in Ester Formation. The Esterification of Benzoic Acid 
with Certain Chlorides; by I. K. and M. A. Puetrs 
mace ts,- Ac. WP Nagin Soro 2 aS Reels a SI Ebal . 296 


Al CONTENTS. 


IN ber eho 4. 


Pp 
Art. XX XIV.—Buried Channels Beneath the Hudson and 
its Tributaries; by J. EF) Kump 2. .....22 2). 301 


XXXV.—Thomson’s Constant, e, Found in Terms of the 
Decay Constant of Ions, within the Fog Chamber ; by 
OC rSARUS. OOF oe a uae ie eae 324 


XXX VI.—Application of the Cobalti-Nitrite Method to the 
Estimation of Potassium in Soils; by W. A. DruswEL. 329 


XX XVII.—Ilodometric Estimation of Chromic and Vanadic 


age 


Acids in the presence of one another; by G. EpGar.__. 3338 
XXXVITI.—Apatitic Minette from Northeastern Washing- 
ton; by F.-L. Ransome (1222-02 222._ 


XX XIX.—Krohnkite, Natrochalcite (a new mineral), and 
other Sulphates from Chile ; by C. Patacue and C. H. 
W aRREN 


XL.—Measurement of Extinction Angles in the Thin Section; 
by EB. E. WRIGRT: .o0) 002 SS 349 


XLI.—Bi-quartz Wedge Plate Applied to Polarimeters and 
Naccharimeters 5 by: KE. . Wright 22) =. ee 391 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Determination of Phosphorus in Phosphor Tin, 
GEMMEL and ARcHBUTT: Complex Calcium Salts, D’Aws, 399.—Radio- 
activity, MarcKWwaALD: Simple Method for Determining Vapor Densities, 
BLACKMAN, 400. 


Geology—La Montagne Pelée aprés ses Eruptions, A. Lacrorx, 400.—Publi- 


cations of the United States Geological Survey : Graptclites of New York, . 


part 2, Graptolites of the Higher Beds, RK. RurepEMANN, 402.—Fourth 
Report of the Director of the Science Division, etc., New York State 
Museum: Rocks and Rock Minerals; A Manual of the Elements of Petrol- 
ogy without the Use of the Microscope, L. V. Pirsson, 408. 


Miscellaneous Scientific Intelligence—Shaler Memorial Expedition to Brazil 
and Patagonia, 1908-09, J. B. WoopwortH: British Association for the 
Advancement of Science, 404. 


Obituary—M. ANTOINE HENRI BEcQUEREL: M. EH. E. N. MASCART: ARTHUR 
LIsTER : ALEXIS HAnsky: J. F. Nery Dexcapo, 404. 


CONTENTS. Vil 


Number: 155; 


Pa 
Art. XLII.—Some New Measurements with the Gas Ther- i 
mometer ; by A. L. Day and J. K. Cuement ___._---- 405 
XLIII.—Range of the a-Rays ; by W. Duanz _._.---.---- 464 


XLIV.—Alteration of Augite-Ilmenite Groups in the Cum- 
berland, R. I., Gabbro (Hessose) ; by C. H. Warren __ 469 


XLV.—Stndies in the Cyperacee, XXVI. Remarks on the 
structure and affinities of some of Dewey’s Carices ; by 
MR GprNowece reels oe a ee PEE ee 478 


XLVI.—Applications of the Lorentz-FitzGerald Hypothesis 
to Dynamical and Gravitational Problems; by H. A. 
Rape MEE UB at) iy ee eye AOS 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Utilization of Atmospheric Nitrogen, A. FRANK: 
Action of Radium Emanation on Solutions of Copper Salts, MpMr. CURIE 
and MpLLE. GLEDITSCH, 509.—Formation of Mists in Presence of Radium 
Emanation, Mpme. Curie: Preparation of Argon, FISCHER and RINGE: 
Chemical Analysis of Iron, A. A. BLair: Decomposition of Water Vapor 
by Electric Sparks, A. Hott and HE. Hopxtnson, 511.—Refiection from 
Glass at the Polarizing Angle, RayLEIGH: Emission of Electrons from 
Glowing Metallic Oxides, F. JEntzscH: Kinetic Energy of the Negative 
Electrons Emitted by Hot Bodies, O. W. RicHarpson, 512. ~ 


Geology and Mineralogy—Die Entwicklung der Kontinente und ihrer Lebe- 
welt, ein Beitrag zur vergleichenden Erdgeschichte; T. Arupt, 512.— 
Archhelenis und Archinotis, H. v. ImeRING, 513.—Camarophorella, a 
Mississippian Meristelloid Brachiopod, J. E. Hype: Geology of Pike 
County, R. R. RowLey: Annual Report of the State Geologist of New 
Jersey, for the year 1907, H. B. Ktimmet: Geological Survey of Canada, 
014.—Mission scientifique au Dahomey, H. Husert.—Fossil Turtles of 
North America, O. P. Hay, 516.—Beautiful Cinnabar Crystals from China, 
A. H. PETEREIT, 517. 


Botany—Gray’s New Manual of Botany, 518. 


Miscellaneous Scientific Intelligence.—Carnegie Institution of Washington, 
519.—Ricerche Lagunari: Beitriige zur Chemischen Physiologie und 
Pathologie, F. HorMeIsTER : Canada’s Fertile Northland, E. J. CHaMBeErs, 
520. 


Vill CONTENTS. 


Number 156. 


Art. XLVII.—Preparation of Urano-Uranic Oxide, U,O,, 
and a Standard of Radio-activity ; by H. N. McCoy and 


Page 


G..Cy ASHMAN’ fou oi 2 bot.) rr 521 
XLVI1II.—Telemeter with Micrometer Screw Adjustment ; 

by BE. Ek Waricur .. 2...) .. 22.) ee 
XLIX.—Device to Aid in the Explanation of Interference 

Phenomena; by F. EH. WRicHt.: -- 2-22) ) 22S 536 
L.—Descriptions of Tertiary Plants, Jl; by Te De 

COCKERELL 20... ... 2222-022 22. ce 


LI.—Three Contact Minerals from Velardefia, Durango, 
Mexico. (Gehlenite, Spurrite and Hillebrandite 5) by 


BE. E. WRIGHT! ©). 222504222 2 
LII.—V olumetric Estimation of Potassiumin Animal Fluids; 

by. W.A. DRusHeL.. 2-222.) 5 555 
LITI.—Meso-Silurian Deposits of Maryland; by Wm. F. 

Prouty.* ).. 225.22 S053 00. Lo Se ar 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Rate of Production of Helium from Radium, J. 
Dewar: Radium in Tufa Deposits, ScHLUNDT: Compound of Cobalt with 
Carbon Monoxide, Monn, Hirrz and Cowap, 575.—Cyanide Processes, E. 
B. Wiuson: Magnetic Rotation of Electric Discharge, D. N. MALiix: 
Directive System of Wireless Telegraphy, E. Brxtuini and A. Tost: Positive 
Rays, J. J. THomson, 576.—Radium Emanation in the Atmosphere near 
the EKarth’s Surface, Eve: Absorption of Roéntgen Rays, W. Sx1Tz: Zee- 
man Effect in Solar Vortices, G. A. Hate: Study of Stellar Evolution, 
an Account of some Recent Methods of Astrophysical Research, G. EH. 
HALE, 977.—Korpuskulartheorie der Materie, J. J. THomson and G. 
SIEBERT.—Magneto- und Electro-Optik, W. Voiet: Evolution of Forees, 
G. Le Bon, 579.—Experimental Electricity, G. F. C. SEARLE: The New 
Physics and its Evolution, L. Porncart: Principles of Mechanics, H. 
Crew, 580. 

Geology and Mineralogy—West Virginia Geological Survey, I. C. WHITE: 
Florida State Geological Survey, E. H. SmLiarps, 581.—Wisconsin Geo- 
logical and Natural History Survey : Geological Survey of Cape of Good 
Hope, 582.—Bergensfeltet og tilstodende Trakt er i senglacial og postglacial 
Tid, C. F. KotpERupP: Mikroskopishe Physiographie der massigen Ge- 
steine ; Ergussgestemne, H. Rosmenpuscu, 583.—Die Fossilen Insekten und 
die Phylogenie der rezenten Formen, A. HanpiirscH: Gahnite, G. M. 
Fuint: Hints for Crystal Drawing, M. Rerxs, 584. 

Botany—Systematic Anatomy of the Dicotyledons, lak: SoLEREDER, 585.— 
Text-Book of Botany and Pharmacognosy, H. Kramer, 586.—Die 
Gestalts- und Lageverainderung der Pflanzen-Chromatophoren, G. SENN, 
587. 

Miscellaneous Scientific Intelligence — National Academy of Sciences: 
National Antarctic Expedition, 1901-1904, 588.—Road Preservation and 
Dust Prevention, W. P. Jupson, 589.—Ostwald’s Klassiker der Exakten 
Wissenschaften: Elementary Dynamics, E. S. Ferry: Plane and Solid 
Geometry, E. A. Lyman, 590.—Moral Instruction and Training in Schools, 
M. E. SApueER : Practical Exercises in Physical Geography, W. M. Davis, 
Twenty-Sixth Annual Report of the Bureau of American Ethnology, 9591. 

Obituary—WiLLI1AM K. Brooks, 591. 


at. Museum. 


‘Librarian 1 U.S. N 


ae 


VOL. XXVL | JULY, 1908. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or Camsrince, 


Proressorss ADDISON E. VERRILL, HORACE L. WELIS, 
L. VY. PIRSSON ann H. E. GREGORY, or New Haven, 


| 

| 

| Proressor GEORGE F. BARKER, or PHILADELPHIA, | 
Proressor HENRY S. WILLIAMS, or ItHaca, 

| Proressor JOSEPH S. AMES, or Battimore, | 

| Mr. J. S. DILLER, or Wasuincron. | 


FOURTH SERIES 
VOL. XXVI_[WHOLE NUMBER, CLXXVI.] 
No. 151—JULY, 1908. 


NEW HAVEN, CONNECTICUT. 
1908 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 


Published monthly. Six dollars per year, in advance. $6. 40 to countries in the 
» Postal Union ; $6.25 to Canada. Remittances should be madeceither is money SG" 
registered letters, or bank checks (preferably on New York banks). _ PG 


Latest Arrival of Rare and Choice Minerals 
and Remarkable Cut Gems. 


Topaz, in matrix, Thomas Range, Utah, $1.50 to $5; Topaz, Schnecken- 
stein, in matrix, from $1 to $4; Topaz, Villa Rica, Brazil, $5; Topaz, xls, 
Mino, Japan, 10c¢ to $2; Martite, Millard Co., Utah, $2 to $4; Pyrite, Gilpin 
Co., Colo., $1 to $8; and from all other known localities. Green fluor and 
Rhodochrosite, Ouray Co., Colo., $2.50 to $5; Rhodochrosite, Ouray Co., 
Colo., $3 to $5; Spheerosiderite, Felsobanya, $1 to $3; beautiful Calcite 
crystals, enclosing copper, Calumet, Mich., $2.50 to $5; Neptunite, San 
Benito Co., Cal., $6; Calomel, Terlinguia, $7.50; Terlinguaite, Terlinguia, 
$6; Herderite xls and in matrix, Auburn, 50c to $15; Cassiterite xls, Tas- 
mania, 25c to $10; Crocoite, Tasmania, and Ural, $5 to $10; Emerald, 
Bogota, and Ural, $5 to $35; Apatite, Auburn, deep lilac color, $2.50 to $15 ; 
Kunzite, xls, Pala, Cal., $1 to $5; Tourmaline, loose xls and in matrix, deep - 
colors, Pala and Mesa Grande, 50c to $275; Whitneyite, Lake Superior 
region, $1.50 to $2.50; Mohawkite, $1 to $2; Algadomite, $1 to $1.50 ; 
Domeykite, var. stibio-domeykite, $1.50 to $2; Petzite, Offenbanya, choice 
specimen, $10; Helvite and Rhodochrosite, Kapnik, $1.50 to $2.50; Rhodo- 
ehrosite, Kapnik, with pink quartz and calcite, 75c to $5 ; Cinnabar, Kapnik, 
$1.50 to $3 ; massive Greenockite, Dognacska, Schneeberg, Vask6, $1 to $2.50 ; 
Proustite and Pyrargyrite, massive, Nagybanya, $3; Proustite, small xls in 
matrix, Nagybanya, $2.50; Polybasite, Hoelritsch, xls in matrix, $3 ; Sylva- 
nite, Offenbanya, Nagyag, and Colorado, $6 to $8; Semseyite, Felsobanya, 
$3 to $6; Uranite, Schlaggenwald, $1.50 to $2; Realgar, Felsobanya, $1.50 
to $7.50; Stibnite with Heteromorphite, Felsobanya, $2 to $3; Chalcedony, 
blue xls, Trestia, $1 to $3; Orpiment, Felsobanya, 50c to $2.50; Tetra- 
hedrite, Kapnik, $1.50 to $5; Stibnite, Felsobanya, 7dc to $5; Stibnite and 
Barite, Felsobanya, $1.50 to $3; Gold in quartz, Verespatak, Abrubanya, 
$3 to $6. 


Remarkable Cut Gems from Russia and other 
Countries. 


Green Garnets, Aquamarines, Amethysts, Zircon, Topaz, Spinel, Sap- 
phires, Star-Sapphires, Star-Rubies, Pink Beryls, Tourmaline, Cat’s-eye, etc. 
Reconstructed Sapphires (the latest discovery). 


These stones have the same hardness and specific gravity as a genuine 
stone and the color and beauty is equal to that of a genuine sapphire. We 
have them in stock from 4 to 2k. at $8 per carat. 

Please send for our circular, issued this month, of our entire stock. 


We PETER. 


81—83 Fulton Street, New York City. 


EHE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES] 
Ba eee 


Art. 1—On the Emission of Electricity from the Induced 
Activity of Radium ; by Wititam Duane.* , 


1. In the winter of 1905-1906, I made some experiments 
on the decay of the induced activity of radium, using as a 
means of measurement the quantity of electricity carried by 


1. 


(Lt 
SAAS 
MMUUMUMIMUMNN a, 


ON 


: 


E DS een 


MLL. 


OL 


N' 


\ 


Connections: p, to pump; e, e, to earth ; I, to electrometer; t, to battery. 


the a and 8 rays instead of the ions produced by them. Up 
to that time this method of studying the decay curves had not 
been employed. A description of the experiments was pre- 
sented at a meeting of scientists held at the University of 
Colorado in the spring of 1906, a brief résumé of which 

* Translation by the author of a paper published in ‘‘ Le Radium” (vol. v, 


p. 65, March, 1908), entitled: Sur l’émission d’électricité par la radioactivité 
induite du radium. 


Am. Jour. Scr.—FourtuH Serises, Vou. X XVI, No. 151.—Juxy, 1908. 
i! 


2 Duane—Lmission of Electricity. 


appeared in Science.* Since then I have been able to repeat 
the éxperiments and carry the investigation somewhat further 
in the radium laboratory of the University of Paris. It gives 
me very great pleasure to thank Madame Curie and her assist- 
ants for their kindness to me during my researches. 

2. Figure 1 represents the arrangement of the apparatus. 
Aisa metallic cylindrical electrode, 11™" long and 3:-42™ in 
diameter, made radio-active by exposure to radium emanation. 
LB is a tube of the same material as A, having an internal 
diameter of 4:°30"". A can be held accurately in a position 
coaxial with 6 by the two metal points aa, and in this position 
there is everywhere a distance of only -44™™" between the outer 
surface of A and the inner surface of 6. The two metal 
points aa are imbedded in ebonite plugs, the upper point being 
completely insulated by the ebonite (in some experiments it 
formed one piece with A), and the lower one connected by 
suitably protected wires to a quadrant electrometer. The cur- 
rents of electricity flowing toward or away from A were meas- 
ured sometimes by the rate of change of the deflection of the 
electrometer, and sometimes with the aid of a piezo-electric 
quartz. The metal rings 64, connected to earth, served as guard 
rings to prevent currents from flowing between A and & along 
the surface of the ebonite. 

3. The methed of procedure was as follows: The elec- 
trode A was suspended by a pair of metal tweezers in radium 
emanation contained in a metal can for a period of at least 20 
hours. It was charged during the period to a negative poten- 
tial of 88 volts with respect to the can, thus insuring approxi- 
mately saturation amounts of the induced activity. At the 
end of the period A and the ebonite plug were quickly placed 
in their positions in the tube 4, and hot sealing wax poured into 
the cup C'so as to form an air-tight joint between the plug 
and the tube. The air between A and 6 was then quickly 
exhausted. In the earlier experiments it was pumped out to a 
pressure of 1 or 2™™ of mercury by means of a mechani- 
cal oil pump, and then the residual air allowed to expand 
quickly into a glass globe previously exhausted to a good 
vacuum. In the later experiments, however, the exhaustion 
was accomplished by means of carbon cooled to the tempera- 
ture of liquid air, the well-known Dewar method. After the 
vacuum had been produced the current flowing to or from A 
was measured at intervals of from two to five minutes, the 
tube B being at zero potential or charged by a battery posi- 
tively or negatively. Usually the first satisfactory reading 
could be taken ten or twelve minutes after the electrode A 
had been withdrawn from the emanation. 


* Science, xxiv, pp. 48-49, 1906. 


Duane—Lmission of Hlectricity. 3 


4. With the tube 6 connected to earth the electrometer 
always indicated a current flowing toward the electrode A, or, 
what would produce the same deflection, a discharge of negative 
electricity away from it. The current ‘continued until the elec- 
trode became charged to a positive potential in the neighbor- 
hood of one volt, at which potential the discharge was apparently 
compensated by a flow in the opposite direction. A Volta 
electromotive force always acts between the tube LB and the 
electrode A, even if they are of the same material. This 
electromotive force could’ be determined by reading the per- 
manent deflection of the electrometer before exhaustion, when 
the space between A and & contained air. diately the deflec- 
tion indicated an electromotive force of about 7th of a volt, 
and always one in such a direction as to oppose ‘the current in 
the vacuum. Hence the observed discharge of electricity can- 
not be due to the Volta electromotive force. The electromotive 
force decreases with the time, but judging from some experl- 
ments | have made, it is not dir ectly due (at least for the most 
part) to the deposit of radium A, B and C on the electrode. I 
have tried to obtain evidence for such a Volta effect, but have 
not succeeded. 

5. The Volta electromotive force, however, alters the mag- 
nitude of the discharge, and for this reason in ‘taking readings 
for the decay curves of the induced activity I adopted the 
usual method of charging the tube B successively to equal and 
opposite potentials. It ‘B is charged to a positive potential of 
1-5 volts or more, a current flows toward the electrode, and 
reversing the sign of the potential reverses the direction of the 
eurrent. The current toward the electrode, however, is con- 
siderably larger than that away from it, the excess being due 
to the discharge of negative electricity from it. 

6. Tables I and II contain several series of readings. The 
amounts of radium emanation used to make the electrode 
radio-active were those produced from 8 or 4™8 of RaBr, 
in one to five days. No attempt was made to collect all 
the induced activity on the electrode, and probably a large 
part of it settled on the tweezers that held the electrode in the 
emanation. Table I contains the results of experiments with 
an iron electrode and tube. In the first column the time after 
the electrode was removed from the emanation is tabulated, 
and in the second and third the currents to and from the elec- 
trode produced by potentials of +2°2 volts applied to the 
tube. First the current toward the electrode (called hereafter 
the positive current) was measured, then two minutes later the 
negative current and so on alternately. The corresponding 
columns of Table II contain similar results for a brass elec- 
trode and tube. 


Saneeinad “se en om 


TABLE I, TABLE II. 
Iron Tube and Electrode Brass Tube and Electrode 
an ie a ee 
Time +Current — Current Time +Current —Current + Current. 
in mm. mm. sum in mm. mm. tg sum for 
min. sec. sec. min. Sec. sec. 0 potential 
11 5°00 1°64 12 2°27 
13 1°68 14 10°50 4°19 4°30 
15 4°72 1°54 16 Oy, 4°14 
17 1°58 18 9°80 3°94 4°05. 
19 4,43 1°45 20 1°86 
74 \h 1°49 22 9°35 Ooi 
23 4°03 1°29 24 Neves 3°59 
25 1°43 26 8°85 3°59 3°38 
27 3°86 1:23 1-28 1°60 3°31 
29 1°39 30 8°33 3°39 3°19 
31 SOrk Sie ay 1.50 
33 1°25 34 7°64 3°08 2°80: 
35 3°16 0:96 36 1°45 
aif 1°20 38 7°00 2°79 
39 2°96 0:90 40 1°39 2°48. 
4] List, 49 6°30 2°46 
43 21S 0°84 44 1°36 2°08. 
45 1°10 46 Sete 2°24 
47 2°55 0°75 48 1°31 
49 1°01 50 5°44 2 
51 2°45 O° = 52 Tels 
ees 0°93 54 5°10 1°99 
565) 2°16 0°63 56 EG 1°70. 
af 0°86 58 4°65 1°79 
59 1°98 Ozar 60 1°03 
61 0°81 62 4°20 1°62 Io 
69 1°59 0°45 70 0°78 
TAI 0°66 72, 3°58 1°41 


+ Duane—LEmission of Electricity. 


7. The same amount of emanation was not used in each ease, 
so that the magnitudes of the currents in the two tables can- 
not be compared with each other; but it will be noticed that 
with brass surfaces the positive current is six times as large as 
the negative, whereas with iron surfaces it is only three times 
as large. Thus the nature of the surfaces has a considerable 


effect on the currents, a fact that was not unexpected, as 
undoubtedly the secondary and tertiary etc. rays from both 
surfaces furnish carriers for the electric charges. 

8. The question whether any cnrrent is due to the ioniza- 
tion of the residual quantity of air left between the metal 
surfaces is an important one, and several series of experiments 


Duane—Limission of Electricity. 5 


were made to test this point. For instance, in one series the 
positive current measured with a liquid air vacuum .was 3:04. 
On allowing air to enter the tube to a pressure (measured 
roughly by a small mercury manometer) of about 1:5™™ of 
- mercury, the current six minutes later rose to 3°21. Six min- 
utes later still the liquid air vacuum having been reproduced, 
the current fell to 2°34. Correcting for the decay of the cur- 
rent by taking the mean (2°69) of the first and last values, we 
see that the ionization in the air at 1°5™™ of pressure increases 
the current from 2°69 to 3°21, 1. e., less than 20 per cent. A 
number of such experiments showed that the currents due to 
ionization in air between A and # at pressure of 1 to 2™™ 
were somewhat less than the currents to be measured, and it 
follows that the infinitesimal quantity of air left after exhaus- 
tion by the liquid air process can have no appreciable effect 
on the currents. This is to some extent due to the fact that 
the surfaces of the tube and electrode were very close together. 
In fact, the apparatus was designed to minimize the effect of 
ionization in the air as much as possible. 

9. The fourth column in Tables I and II contains the values ~ 
of $ the algebraic sum of the positive and negative currents. 
This $ algebraic sum represents roughly the discharge per 
second of negative electricity from the electrode in zero electric 
field less the negative electricity received by the electrode per 
second from the surface of the tube. Let e be the difference 
between these two currents, and =k be the current produced by 
the applied electromotive force: 2 represents, then, the effect 
of the impressed electromotive force on the slow-moving 
electrons projected from the metallic surfaces. When the 
tube is charged positively, the positive current is 


10 ay Ce od, (1) 
and when charged negatively, the negative current is 
Wee Gi res Be (2) 
and evidently 
a, or a, 
C= 
2 


10. The above is the usual method of analyzing the currents 
in similar cases, but the theory contains two assumptions, first 
that the small electromotive force (2°2 volts) does not percepti- 
bly change the value of e, and second that the current 7 has 
the same absolute magnitude whichever way the electromotive 
force acts. It is probable that neither of these assumptions is 
absolutely correct in the present case, but that the equations 
approximately agree with the facts may be seen from the 
following experiments. 


6 Duane—Emission of Electricity. 


11. The decay of the rate of discharge of electricity from 
the electrode with 6 put to earth was studied. For this pur- 
pose a zero method of measuring the currents is necessary, and 
the piezo-electric quartz was chosen, for in measuring currents 
by it the electrode is always held at zero potential. The eur- 
rents measured by the quartz with 6 put to earth, but other- 
wise under the same conditions as before, appear in column 5 
of Table II. These data represent a series of measurements 
distinct from that tabulated in columns 2 and 3. In order to 
reduce the readings to the same scale the positive currents 
under an electromotive force of 2°2 volts were measured several 

times, for instance at ¢=22, 36 and 64. With these values for 
comparison the measurements with the quartz were reduced 
to the same scale as the others. It will be noticed that the 
discharge current e for zero potential is with two exceptions 
some 10 per cent less than the $ algebraic sum of the currents 
tabulated in column 4. This difference is in part at least due 
to the Volta electromotive force, which, as I mentioned above, 
always acted in such a direction as to reduce the discharge of 
negative electricity from the electrode. From these experi- 
ments it appears that equations (1) and (2) are roughly correct. 

12. We can, however, analyze the currents in other ways. 
We can, for instance, say that the currents are due to two 
streams of electricity s, and s, projected from the surfaces of 
the electrode and tube respectively ; that when no electromotive 
force acts the current is 

C= nisin aS) 
and that when an electromotive force is applied. one of the 
two streams, s, or s, is more or less checked. If As, and As, 
are the changes produced by the electromotive force, the 
positive and negative currents are : 


4, = 8° —' (s, = AS; ):= s,s) ass 
On 3S, = AS, = 8, eS i 


If As,>s,—s,, there would be a resultant current away from 
the electrode in the second case. Applying this theory to the 
data for the brass electrode, it appears that for 2°2 volts As, 
and As, must be some 50 per cent larger than s,—s,; that is, 
there must be a large number of slow-moving 8-particles pro- 
jected from both surfaces, rays that 2 volts will stop. Such 
rays are produced by polonium,* radiumt and other radio-active 
substances. The experiments further show that approximately 
As,=As, for the same electromotiye force. The assumption 
made in this theory is that the value of s, does not depend on 

* J. J. Thomson, Nature, Dec. 15, 1904. Proc. Camb. Phil. Soc., xiii, Pt. 1, 


p. 39, 1909. 
+ KE. Rutherford, Radio-activity, pp. 151-104. 


Duane—Emission of Electricity. us 


that of s,, and vice versa. As the secondary rays depend on 
the primary, and as there are tertiary rays depending on 
the secondary, etc., this assumption is probably not strictly 
correct. : 

Of course s, and s, may be further analyzed into their con- 
stituents a and @ rays, secondary and tertiary, ete. 

13. We now come to the important question, do the degay 
curves that can be drawn with the datain Tables I and II coin- 
cide with curves drawn from ordinary ionization data? It will 


(oe) 


“yaLINAO 


Time in minutes. 


be seen that they do not. For comparison I measured the cur- 
rents due to the ionization in air produced by the a rays, when 
the electrode was made active in exactly the same way as 
before. The electrode, after being withdrawn from the ema- 
nation, was placed opposite a hole in a large condenser, and 
the decay of the ionization current due to the a rays measured. 
Table III, column 2 contains the valnes of the currents meas- 


8 Duane—Lmission of Electricity. 


ured by the piezo-electric quartz, and column 1 the time in 
minutes after the electrode had been withdrawn from the ema- 
nation. In order to compare them, I have drawn this curve 
and the curve representing the decay of the positive current 
for the brass surfaces (Table II, column 2) together in figure 2. 
Curve 1 represents the decay of the a ionization current in air 
at atmospheric pressure, and curve 2 that of the positive enr- 
rent in vacuum. The scales of the two curves were so chosen 
as to make them coincide at ¢= 70. It is easily seen that they 
do not coincide at other points, the curve representing the 
charge carried by the rays being much steeper than the other. 

14. The explanation of this undoubtedly is that radium B, 
which under ordinary circumstances produces an almost map- 
preciable amount of ionization, does emit a very appreciable. 
number of negatively charged rays. For the sake of compari- 
son, I have calculated the theoretical curve that one should get 
under the supposition that radium B emits as much electricity 
during its change as radium C does during its. This is curve 
3 in the figure. It is drawn under the assumption that there 
is on the electrode, to start with, equilibrium amounts of 
radium A, Band C, i. e., amounts that are inversely propor- 
tional to their respective decay constants, and that initially the 
quantity of radium B present emits as much electricity per 
second as does the quantity of C present. The scale of the 
theoretical curve was chosen so as to coincide with the others 
att = 70, and it appears that the experimental curve 2 is a 
little steeper even than the theoretical one. In making the 
calculations I used constants corresponding to decay to half 
value in 3, 28 and 21 minutes respectively, for radium A, B and 
C. Itis probable that the last two values, 28 and 21, are too 
high. Slightly smaller values would bring the theoretical 
curve closer to the experimental one. 

All the curves that I have examined representing the posi- 
tive currents and the 4 algebraic sum of currents, are steeper 
than the theoretical curve. Curves representing negative cur- 
rents are usually somewhat less steep than those representing 
positive currents, but lie much nearer curve 3 than curve 1. 
It follows that radium B must emit its full share of negative 
electricity when changing into C. 

The theoretical curve representing radium O alone coincides 
so closely with curve 1 that I have not drawn it in the figure. 

15. In some interesting experiments H. W. Smith* has 
shown that radium B produces a slight ionizing effect. He 
attributed the ionization to easily absorbed rays, probably 6- — 
rays. The ionization produced by rays from radium B can be 
shown very easily with the aid of the apparatus used in the 


* H. W. Schmidt, Physikal. Zeitschrift, vi, 897-903, 1905. 


Duane—Emission of Hlectricity. 9 


above described experiments. In one ease the electrode A was 
made active exactly as before, placed in position in tube B and 
the currents measured at atmospheric pressure instead of in 
vacuum by means of the piezo-electric quartz. Column 3, 
Table III contains the results reduced to the same scale as those 
in column 2 for ¢=70. It appears that they by no means 
coincide except for ¢=70. In fact the data of column 38 repre- 
sent points that would he much more nearly on the theoretical 
curve 3 (figure 2) than on curve 1. This can be due only to 
the ionizing effect of radium B, and indicates that within a $™™ 
of the surface the rays from radium B produce ionization com- 

arable with that produced there by the rays from radium C. 

his large ionization would be explained, if radium B produced 
a rays having a velocity just greater than the critical velocity 
required to produce ions. Such an hypothesis, however, is not 


TaB_eE III. 

Time in Current in Current in 
minutes large con. small tube 
10 3°O1 4°15 

12 2-9 
15 2°91 3°84 
1b 2°86 
20 2°83 3°03 
25 2°76 3°30 
30) 2°54 3°09 
35 2°38 2°89 
40) 2°26 nee Oe 
45 2°04 
50 2°01 | 
55 1°83 
60 1°70 1°80 
65 1°58 | 1°59 
70 1°42- 1°42 
79d 1°31 


absolutely required by the facts, and would contradict some 
results obtained by Bronson.* | 
16. In order to estimate the velocity with which the carriers 
of electricity are projected from the metallic surfaces the brass 
electrode and tube were placed between the poles of an electro- 
magnet and a magnetic field of 996 units produced parallel to 
their common axis. The currents were measured alternately 
with and without the field to correct for their decay during 
the experiments. The measurements indicate that both the 
positive and negative currents and also their algebraic sums are 
diminished by the magnetic field. According to the well- 


* Bronson, Phil, Mag. (6), xi, 806-812, 1906. 


10 Duane—Lmission of Hlectricity. 
known formula for the radius # of the cylinder along the sur- 
face of which a 8-particle moves in a magnetie field /7, 


_—m U 

ne 

when w is the component velocity normal to the field, m 
the mass and e the charge of the particle. If any of the 
particles projected from one surface have velocities so small 
that /? is less than + the distance to the other surfaces, 0°22™™ 
they will not reach the other surface. Further, some par- 
ticles for which / is greater than this will be cut off also, 


va 


by the field. Assuming that the ratio < for the carriers of 


electricity is that of the electrons, namely 1:87 X10’, the 
velocity for which /7=0-022™ is . 


u= HR~=4x10° 
MW 


It follows that a considerable number of the electrons must 
have velocities near or less than 4 10°. | 

17. The effect of increasing the electromotive force applied 
to the tube & was also studied, measurements being taken 
during a series alternately with 1°5 volts and voltages rang- 
ing up to 80 volts. It appears that both the positive and neg- 
ative currents are considerably increased by increasing the 
electric field, and that, up to 40 volts at least, their algebraic 
sum is decreased. These results can be explained on the 
assumption that the currents are carried by the #-particles 
shot off from the surfaces. An electric field between the con- 
ductors stops some of them. To calculate the velocity that 40 
volts would stop we have 


Lmu'=40 x 10°e 
or Uu=—3'8X10° 


It follows, as before, that a considerable number of the elec- 
trons must be projected with component velocities to the sur- 
faces in the neighborhood or less than 4X10". 

18. Combining the electric and magnetic effects we might 


calculate values for both < and wu, but owing to the complexity 


of the rays, and the difficulty of estimating just how many 
particles have velocities under a given limit, such estimates 
would not be worth much. The experiments show, however, 
that the order of magnitude of the effects are such as would 
be produced, if the currents were carried by §-particles, a 
considerable number of which had velocities normal to the 
surfaces in the neighborhood of 4X 10° or less. 


Duane—ELmission of Electricity. 11 


19. Experiments were made to measure the ratio between 
_ the charge carried by the rays from the induced activity and 
the charge carried by the maximum number of ions that can 
be produced in air by the same induced activity when all the 
a rays are absorbed in the air. As the latter is several thou- 
sand times the former, it is better to measure the ratio in two 
steps. In the first step, with the electrode A in the tube JB, 
the ratio between the currents at atmospheric pressure and in 
a liquid air vacuum was measured, and in the second, witha 
smaller amount of activity, the ratio between the currents 
with the electrode in the tube, and in a larger condenser, was 
measured, both at atmospheric pressure. The product of the 
two ratios is the ratio required. ; 

20. For the first step, the brass electrode having been made 
radio-active as before, it was placed in position in tube & and 
eurrents measured with the piezo-electric quartz at atmospheric 
pressure. Then the tube was rapidly exhausted by opening a 
stop-cock communicating with the reservoir containing carbon 
cooled to the temperature of liquid air, and the currents meas- 
ured again. ‘The electromotive force each time -was 2°2 volts 
Gi. e., 50 volts per cm.). The data appear in Table IV. 
Making the small corrections for the decay of the activity, we 
find for the ratio of the currents in air to that in vacuum, 61 
for ¢= 13, and 69 for ¢= 64. Other experiments gave values 


TABLE LY. 

Time — Positive Current 
10 52-5 } ty 
11 51-4 Atmospheric pressure 
13 0°82 
14 0-78 I Liquid air vacuum 
60 24:0 | Biel Pos! 
62 3-1 f Atmospheric pressure 
64 7 0322 Liquid air vacuum 


ranging from 66 to 70 for 60 to 70 minutes after the electrode 
had been removed from the emanation. Farlier than this the 
ratio is smaller, owing undoubtedly to the fact that there is 
then proportionately more radium B en the electrode. 

21. To measure the ratio of the current in the tube & at 
atmospheric pressure and the saturation current when all the 
a rays produce ions in air, a large cylindrical condenser was 
constructed 19°8™ long and 17-9°" in diameter. <A rod of 
brass suitably insulated held the electrode A at the center of 
the condenser, and at the same time acted as the electrode. A 
very much smaller amount of induced activity than before 


12 Duane—Envission of Hlectricity. 


having been deposited on 4, the currents were measured first 
in the small tube and then in the large condenser, ete. One set 
of measurements is given in Table V. Making the correction 
for the decay of the activity, the ratio of the two currents at 
62 minutes is 52-4. (The currents in the table are already cor- 
rected for a small ionization in the condenser before A was 
inserted.). | 

22. Combining this with the ratio previously determined, 
69, we find that the saturation current in air when the a rays 
produce all the ions they can produce is 3,600 times as large 
as the positive current in the tube & in a liquid air vacuum, 
produced by the same activity. In these experiments the pre- 
caution was taken of sand-papering the end of electrode A, so 
as to remove all the activity deposited there. 


TABLE V. 
Time + Current Electrode 
55 9°45 in tube 
(8 uae in condenser 
63 LLG 
70 er OO ‘ 
n] 6-95 in tube 


23. The total quantity of negative electricity emitted per 
second in vacuum from the electrode A is at least as great as 
the $ algebraic sum of the positive and negative currents, and 
probably is greater than the positive current itself. The ratio 
of the positive current to this $ algebraic sum is (for 2°2 volts) 
2°5 for brass. Hence the negative electricity discharged per 


second from the electrode is at least as great as the ———___>= 
3600 X 25 


th part of the ionization current the a rays from its radio- 


000 
activity are capable of producing. Rutherford* has found 
that each a particle projected from radium produces 86,000 
ions. Assuming that each a particle from radium OC produces 
a number of ions proportional to the length of its path and to 
the excess of its energy over the critical value, namely, 180,000 
ions, it follows that for every a particle projected by radium C 
there are at least 20, and probably more than 50, electrons 
expelled from the active surface. 

24. Conclusions. (a) A piece of metal made radio-active 
by immersion in radium emanation emits considerable quanti- 
ties of negative electricity ; and the rate of discharge decays 
with the time in such a way as to indicate that radium B when 


* Rutherford, Radio-activity, p. 454, 


Duane— Emission of Electricity. 13 


changing into C discharges as much electricity as does radium 
C when changing into D. 

(b) A magnetic field parallel to the active surface stops part 
of the emission of electricity ; and an electric field normal to 
the surface also alters the rate of discharge, the magnitude of 
the electric and magnetic effects being about what would be 
expected if the charge was carried by electrons, a considerable 
portion of which had component velocities normal to the active 
ee 

sec 

(c) The total quantity of negative electricity emitted per 
second by an active brass surface is at least as large as the 
ere) part, and probably larger than the oF th part of the 
9000 3600 
ionization current that can be obtained from the activity, if the 
a rays from radium C are completely absorbed in the air pro- 
ducing thelr maximum ionization; 1. e., the number of ions 
produced by the a rays in air is less than 9,000 times, and probably 
less than 3,600 times the number of §-particles expelled from 
the wire during the same time. Assuming that each a particle 
from radium C can produce 180,000 ions, this means that for 
every a particle expelled from radium C, at least 20 and proba- | 
bly more than 50 electrons are emitted from an active brass 
surface. 

(qd) The number of ions prcduced by radium B in the air 
at atmospheric pressure close to (i. e. within 4 a mm. of) the 
active surface is comparable with the number of ions produced. 
in the same space by radium C. 


surface in the neighborhood of, or less than, 4x1 


Radium Laboratory, University of Paris, 1908. 


14 Prescott—Llvaite fram Shasta Co., California. 


Art. IL—Zlvaite from Shasta Co., California; by Bast. 
Prescorr, Stanford Unive ersity. 


Tue ilvaite described in this article occurs at Potter Creek, 
Shasta Co., California. The locality is well known to seolo- 
gists on the Pacific coast, for it was from the caves in the 

Jarboniferous limestone at this place that Dr. Merriam 
unearthed the Quaternary vertebrate remains,* and recently 
it has also attained some economic importance from the 
exploitation of the magnetite bodies that occur at the contact 
of this same limestone with an intrusion of diorite. It was 
during an examination of these ore deposits early in the pres- 
ent year that the writer noticed the presence of ilvaite. 

Lindgren+ has cited this mineral as a typical product of 
contact “metamorphism, and the occurrence and association as 
seen in Potter Creek are in accord with this view. There 
were two occurrences noted. On both sides of a six-inch dike 
cutting through the limestone, a half-inch band of pure mas- 
sive ilvaite was found, this, in places, sending out rough rec- 
tangular prisms into the limestone an inch or more in length. 
A tew feet away, further search was rewarded by a number 
of ilvaite crystals associated with a coating of eroded quartz 
crystals on hedenbergite, a more common contact mineral. 
The crystals are about 7 to 8™ in greatest dimension and are 
well formed, doubly terminated and symmetrical. The extremes 
in habit are shown in the figures, but even in the more elon- 
gated the prism zone is not as well developed as in the erys- 
tals from Elba. 

Although the crystals are bright and untarnished, the sig- 
nals were not distinct, and close measurements were 1mpossi- 
ble on account of vicinal faces and striations. The forms 
present are m-(110), s(120), 6(010), o 111), 7 (101), (890) (%) all 
of which are those more commonly developed in ‘ilvaite with 
the exception of the doubtful new form (890) found on two 
crystals, where it repiaces the prism m (110). The following 
measurements serve to identify the forms, the zone [8, s, m,| 
taken from one crystal, the zone [o, 7,| from a second, as the 
two were not found measurable on the same cr ystal. 

The most striking physical characteristics of the mineral as 
seen in this occurrence are the submetallic luster and greenish 
brown streak. The absence ‘of limonite as an alteration prod- 
uct is noticeable. The cleavage is not prominent and neither 
the specific gravity nor the hardness would distinguish it from 

* Sinclair, Cal. Univ. Publ. Am. Arch. and Eth., vol. ii, pp. 1-27, 1904. 


+ Character and genesis of certain contact deposits. Trans. Amer. Inst. 
M. E., vol. xxxi, p. 227, 1901. 


Prescott—Ilvaite from Shasta Co., California. 15 


Measured Theoretical 

en, S$). (010 7.120) 36° 40! BO. 52" 
MAS (l10A 120) 20S OS LO 27. 
mAmUt (1107110) 66 9°45 Gh ro? 
Ont, (EEL ROE) 20 7 20 7 
oe OU CRE Tee) 40 28 40 15 
(890A 120) Ge ss35* 16:6 


minerals of similar appearance. Before the blowpipe it fuses 
readily with slight intumesence to a magnetic globule, yields 


a small amount of water at high temperature in a closed tube 
and is readily soluble in hydrochloric acid, giving a gelatinous 
residue upon evaporation. 


Moss, Hillebrand,t Hoffman,t 
Shasta Co., Owyhee Co., Vancouver Theo- 
Cal. Idaho Island, B. C. retical 
3 eee 28°09 29°16 29°81 29°3 
PO “32 “52 0°16 a he 
BO) 7 a 20°80 20°40 18°89 LOG 
Lie @ eae DOaoS 29°14 32°50 39°2 
mG bys 3°24 5°15 2°22 eee. 
CAO. es 15°89 13°02 13°82 Ras 7 
BESO eS ef ire: "15 30 Dae 
ON e42 ors i ie 08 in aie ven? 
Be Ore 13 ca soc See 
3 UU A aparece 1°62 2°79 «21°62 2°2 
BGA (2s ee 100°20 100°41 99°32 100°00 


* This agreement is accidental, as the recorded value is the average of 
many readings on several faces. 

+ Bulletin U. S. G. S. No. 207, p. 45. 

¢ Vol. 5, Annual Rep. Geol. Survey of Canada, 1889-90. 


16 Prescott—Livaite from Shasta Co., California. 


The material for the analysis given above was sorted from 
the massive ilvaite and all por tions that might contain impuri- 
ties or inclusions were carefully excluded. It was then sub- 
mitted to H. R. Moss, whose results are tabulated (p. 15) with 
the two analyses available for America and with the theoreti- 
eal for HOaFe,™ Fe™ Si,O,, given by Dana in the sixth edi- 
tion of the Sy stem of Miner alogy. 

The material was air-dried at 95° C., and the total water 
obtained by a modification of Pentield’s tube method. The 
only deviation from the usual course of analysis was in the 
determination of the manganese by triple precipitation as 
MnO, with bromine, in the filtrate from a basic acetate separa- 
tion, and the subsequent precipitation of the chromium with 
ammonia. 

Thanks are due Dr. A. F. Rogers, Stanford University, for 
advice and assistance in the preparation of this note. 


R. A. Daly—Mechanies of Igneous Intrusion. 17 


Art. Wl—TZhe Mechanics of Lgneous Intrusion.* (Third 
Paper;) by Reeryatp A. Daty, Massachusetts Institute of 
Technology, Boston. 

Introduction. 

Hypothesis of magmatic stoping. 

Field relations of the typical batholith. 

Contact-shattering. 

Relative densities of magma and xenolith. 

Sinking of the shattered blocks. 

Problem of the cover. 

Supply of the necessary heat ; magmatic superheat and its causes. 

Capacity of superheated, plutonic magma for melting and dissolving 

xenoliths. 

Objection founded on rarity of evidences of assimilation at observed 

wall-rocks. 

Abyssal assimilation. 

Existence of basal stocks and batholiths. 

Differentiation of the syntectic magma. 

Origin of granite; the petrogenic cycle. 

Origin of magmatic waters and gases. 

Conclusion. 

Introduction.—In the April and August numbers of this 
Journal in the year 1903, the writer published papers outlin- 
ing the hypothesis of magmatic stopmg as explanatory of the 
rise of batholithic magmas in the earth’s crust. The hypothesis 
had taken form in his mind after some ten years of perplexity 
as to the mode of intrusion which has actually characterized 
granite bodies. In Vermont, New Hampshire, British Col- 
umbia and other regions he had met with this urgent and 
important field-problem. Everywhere the facts derived from 
field observations were, in principle, the same; the method of 
intrusion seemed, for each batholith or stock, to be the same. 
Since the writing of the two papers the writer has studied in 
some detail a dozen other large batholiths and as many typ- 
ical stocks occurring on the southern boundary of British Col- 
ambia. For all of these also the stoping hypothesis appears 
to afford the truest explanation of the mode of intrusion. 

Quite independently Barrell arrived at a similar hypoth- 
esis, as he attacked, in 1901, the problem of the ‘‘ Marysville 
bathohth” in Montana. Unfortunately his monograph was 
delayed im publication until 1907, so that it is only quite 
recently that geologists have had the benefit of this brilliant and 
thorough study of intrusive mechanism.t Barlow and. Cole- 
man have noted their belief in the efficiency of stoping as an 
intrusive process. At the other side of the world, Andrews 
has described the great intrusive masses of New South Wales, 

* Published by permission of the Commissioner for Canada, International 
Boundary Surveys. 

+U. S. Geol. Surv., Prof. Paper No. 57, 1907. 


+A. E. Barlow, Ann. Rep. Geol. Surv. of Canada, xiv, Part H, p. 79, 1904; 
A. P. Coleman, Jour. of Geol., xv, p. 773, 1907. 


Am. Jour. Sct.—FourtaH Series, Vout. XXVI, No. 151.—Junry, 1908. 
2 


18 RR. A. Daly—Mechanics of Igneous Intrusion. 


and most forcibly shows the value of the stoping hypothesis 
and of its implied principles in explaining the rocks and field- 
relations in that state.* 

Notwithstanding the:support given the hypothesis by the 
work of these and other observers, the main conception has 
not met with favor from many working geologists.t A num- 
ber of objections have been raised, most of which were dis- 
cussed in the first two papers of this series. Within the last 
five years an unusually large amount of experimental data has 
been added to the confessedly meager store of known facts 
concerning the physies of rocks and rock-melts. These labor- 
atory results, when fairly interpreted, seem to the writer to 
dispose of most of the objections. Other objections fall away 
as soon as they are confronted with the indisputable, long- 
known facts concerning rocks and igneous magmas. A third 
class of the objections are more stubborn and still remain 
among the frank difficulties of the stoping hypothesis. It is, 
however, the writer’s belief that these difficulties are small 
when compared to those adhering to the older theories of 
batholithic intrusion. 

In this third paper some of the more significant, newer con- 
tributions of the experimental laboratory to the matter at issue 
will be noted and discussed. In the ight of the whole body 
of fact as understood by the writer, he will attempt to make 
clear the reasons why the various criticisms against the stop- 
ing hypothesis do not seem fatal to its acceptance. Finally, a 
new statement of certain important corollaries and tests of the 
hypothesis will be offered. In their discussion a certain 
amount of speculation seems not only warranted but necessary. 
It is obvious that the basis of any theory of the igneous rocks 
must, in part, consist of speculative assumptions; for every 
fruitful theory must deal with the earth’s invisible interior. 
Neither petrology nor geology can afford to leave the problem 
of the earth’s interior “to the poets.” The advances of mod- 
ern chemistry have largely been made possible through con- 
structive speculation as to the nature of molecule and atom; yet 
molecule and atom are as inaccessible as the core of the earth. 
In the nature of the case we can never hope to arrive at the 
final explanation of igneous-rock bodies without building and 
testing hypotheses of materials and processes in and under 
the earth’s p ernel. ” Not only petrology but, in marked 
degree, mining geology is awaiting a stable theory of batho- 


lithie intrusion, since upon it must. lar gely depend sound pet- - 


rogenic and minerogenic theory. 

*E. C. Andrews, Records, Geol. Surv., N. S. Wales, vii, Pt. 4, 1904, and 
viii, Pt. 1, 1905. 

+ Cf. Science, xxv, p. 620, 1907. 


R.A. Daly—Mechanies of Igneous Intrusion. no 


Like the first and second papers, this one does not present a 
complete discussion of the different topics. On another 
occasion the writer may publish a fuller statement of the 
favored solution of the complex problem. 

Hypothesis of magmatic stopig.—The essential points are 
the following: 

1. Each acid, batholithic magma has reached its present 
position in the earth’s crust largely through the successive 
engulfment of suites of blocks broken out of the roof and 
walls of the batholith. 

2. The blocks ( xenoliths) are completely immersed in the 
magma, partly through the confluence of apophyses which 
have been injected on joints and other planes of weakness in 
the country-rock; more often the blocks represent the effect of 
shattering, due to the obviously unequal heating of the solid 
rock at magmatic contacts. 

3. The sunken blocks must be dissolved in the depths of 
the original fluid, magmatic body, with the formation of a 
“ syntectic,”* secondary magma. 

4. The visible rock of each granite batholith or stock has 
resulted from the differentiation of a syntectic magma. 

In applying the hypothesis to the explanation of actual 
field-occurrences other general considerations seem necessary. 
Stoping and abyssal assimilation on the batholithic scale are 
begun by a primary basaltic magma. This magma carries the 
heat required for the double action.t The source of the 
magma is to be found in a general basaltic substratum beneath 
the earth’s solid crust. The crust is considered as composed 
of two shells. The lower shell is capable of injection by 
huge masses from the substratum, which retains open com- 
munication with the injected bodies. The latter are regarded 
as then stoping their way up into the overlying shell, in which 
the resulting derivatives of the syntectic magma are the 
visible batholithie granites and allied rocks. 

These subsidiary elements of the problem here to be dis- 
eussed have been described in the first intrusion paper and, 
more fully, in a later communication on “ Abyssal Igneous 
Injection.”{ No one of these additional conceptions is essen- 


*This very convenient name for a magma rendered compound by assimi- 
lation or by the mixture of melts, has been proposed by F. Loewinson— 
Lessing, Comptes Rendus, 7° session, Congres géol. internat. St. Petersburg, 
1899, p. 375. 

+ Whether the substratum is actually or only potentially fluid is not a 
vital question in this connection. T. J. J. See, as a result of his calcula- 
tions, holds that the earth’s interior may be fluid. He explains the observed 
rigidity of the planet as due not to its being a true solid but to the direct 
influence of gravity, which binds the earth-shells so effectively that bodily 
tides are almost wholly prevented. In any case rigidity and solidity are not 
synonymous terms. Cf. T. J. J. See, Astron. Nachrichten, v. clxxi, p. 
378, 1906. 

¢ This Journal, vol. xxii, 1906, p. 195. 


20 RR. A. Daly—Mechanics of Igneous Intrusion. 


tial to the idea of stoping per se. All of them may prove 
incorrect without invalidating the stoping hypothesis in its 
main feature. Combining them and the idea of stoping, the 
writer has constructed a general working hypothesis for the — 
origin of the igneous rocks. It seems, therefore, expedient 
in the present paper to discuss the pr oblem in its lar ger aspect. 

Field Relations of the typical batholith.—& principal faet 
on which the stoping hypothesis is based has been amply illus- 
trated in the published descriptions of granite stocks and. 
batholiths. Most, if not all, of these bodies in their accessi- 
ble portions have replaced nearly equivalent volumes of the 
respective country-rocks. They are generally cross-cutting 
bodies. Their roofs are rough domes or arches, from which 
large masses of the invaded rocks are sometimes pendant into 
the crystallized granite. In each of many cases erosion has 
destroyed much of the roof, and the roof-pendants, still pre- 
serving: the regional strike of their structure planes, are to-day 
exposed in section at the erosion-surface. Between the pend- 
ants and between the main walls of a large batholith, hun- 
dreds of cubic kilometers of country-rock formations are 
plainly missing; their place has just as plainly been taken by 
the granite. 

A second principal fact is that, so far as granite batholiths 
and stocks are known, each of these bodies shows a eross- 
section enlarging with depth.* No one of them has yet 
exhibited a floor composed of older formations. In relation to 
visible country-rocks, all of them may be classed as subjacent, 
rather than as injected, bodies. In relation to the wall-rocks 
ten or more kilometers below the earth’s surface, each batho- 
lith may have been truly injected asa kind of gigantic dike, 
but of this there is no direct proof. The actual observations in 
the field show unequivocally that the batholithic magmas have 
worked their way up by replacing and absorbing the country- 
rocks through the last few kilometers of ascent. Bathe 
are not laccoliths. 

A third generally observed fact is worthy of special ater 
tion. Where erosion has been profound the ground-plan see- 
tion of the typical stock or batholith is seen to be elliptical 
and the profile-sections, as already noted, show that the upper- 
contact surface of the intrusive is dome- shaped. Both in 
ground-plan and in vertical sections the contact-surface is 
relatively smooth. Apophysal offshoots do interrupt the wall- 
rock, but the main-contact lines as mapped on ordinary geolog- 
ical maps are characteristically flowing lines. Large-scale, 

*See the numerous sections of stocks and batholiths in Lepsius’ ‘‘ Geo- 
logie von Deutschland” ; also Barrell’s monograph cited, and the writer’s 


paper on the Okanagan Composite Batholith, Bull. Geol. Soc. America, xvii, 
p. 3380, 1906. 


R. A. Daly— Mechanics of Igneous Intrusion. 21 


angular projections of country-rock into a well uncovered 
batholith are comparatively rare. Such smoothness of main- 
contact surfaces is that which is to be expected on the stoping 
hypothesis. A projection of country-rock would suffer spe- 
cially intense shattering by the magma, which would thus tend 
to destroy the projection and smoothen the wall of contact. 
The case is analogous to the familiar exfoliation on sculptured 
stone in great city fires; architrave, sill, abacus and plinth 
lose their corners, ornaments in high relief are rifted off, and 
flutings are effaced. Bowlders of disintegration through 
weathering furnish other analogies. 

In detail of form as in the larger field-relations of the typi- 
eal stock and batholith, therefore, we seem to have cumulative 
evidence in favor of the theory of replacement and especially 
in favor of the hypothesis of mechanical replacement. On 
the other hand, the more intimate becomes our knowledge of 
these field- relations, the more improbable the “laccolithie 
theory” becomes. Neither smooth, flowing contact-surfaces 
against a heterogeneous terrane, nor a general elliptical ground- 
plan, nor an invariable downward enlargement are expected 
to characterize a batholith if it is simply a huge laccolith. 

These summary statements are founded on the writer’s field- 
experience, and on a tolerably wide study of the geological 
literature relating to granitic intrusions. ‘The essential idea 
of replacement rather than displacement is far from new; it 
has been a lasting merit in the able work of Barrois, Michel 
Lévy, Lacroix and others, that they have persistently held to 
this fundamental fact of. field-occurrence. Yet there are 
to-day many working geologists who just as persistently refuse 
to recognize the fact of the field. The chief reason for this 
refusal has undoubtedly been that the replacement of the 
country-rocks has, until recently, been attributed to their pro- 
gressive solution on the main. contacts—in other words, to 
marginal assimilation. The patent difficulties of this one view 
have prevented many, perhaps most, geologists from subserib- 
ing to the conclusions of their French colleagues. The proved 
insufficiency of the marginal-assimilation hy pothesis has thus 
discouraged belief in that kind of replacement, but it by no 
means alters the fact of magmatic replacement. On the other 
hand, this fact will stand, no matter what theories of intrusion 
may. prevail. 

So far as recorded, the stoping hypothesis is the only one 
which recognizes the progressive assimilation of country-rocks 
as the magma rises in the crust, and, at the same time, 
explains the common lack of chemical sympathy between 
granites and their respective wall-rocks. By this hypothesis 
the preparation of the upper and visible part of the mag- 
matic chamber is largely a mechanical process, working along 


22 Rk. A. Daly—Mechanics of Igneous Intrusion. 


main contacts; the solution of the engulfed blocks is effected 
far down in the depths of the magma—by abyssal assimila- 
tion. The resulting syntectic magma may thus be in strong 
chemical contrast with the adjacent wallLrock at any one level. 
Marginal assimilation is not excluded but is considered as an 
accessory and subordinate phase in the act of replacement. 

Contact-shattering.—It has been objected. that rocks are 
good conductors of heat and that, therefore, strong temperature 
differences with resulting rending strains are not to be expected 
in the shell of country-rock immediately surrounding a batho- 
lithic magma. This objection has been recently made by an 
expert physicist now specially engaged on petrological problems, 
and evidently needs consideration.* The following table of 
coefficients of absolute conductivity seems, however, to show, 
on the contrary, that rock-matter is far from being ranked as 
a good conductor. The table has peen made by compiling the 
values noted in the Landolt- Bornstein’s Physikalisch-chemische 
Tabellen (1905 edition) and in Winkelmann’s Handbuch der 
Physik. The values for the rocks are of the order expected 
in view of the familiar proofs of the extremely slow cooling 
of lava-flows.t 


k 
Silver, “aboutmec tive ee sane 1:0000 
» Coppers aera as man Omen "9480 
Dead 22s Base es ee ae eens SOG 
(UATE oe ee eee es 0158 
Marble Sat tos ay niece ete "00817 
Granite messi a 222. (00757 — 008% 
Gnesi een Ite Perot tase aa °000578—:00817 
DPandstone esha he Uh eee "00304 —-00814 
Basalt: 2215 ee pale sk en ae gee °00673 
DY CULC ie sees he einer ieee "00442 
GlgSs) 3. Pelee ona Wee ener ‘00108 -—-00227 
Water, abouteee 2. hee 00130 
Papert) 222 ee eee "00031 
Flannel)? 23a o0e ec enon "00023 
Sie ee ee eee "00022 
Cork OD a eee ‘00013 
Feathers 32.2 2 eee "0000574 


* Of. A. L. Day, Science, xxv, p. 620, 1907. 

+The steepness of the possible temperature gradient in the wall-rock is 
shown by the fact that, a few days after lava ceases flowing, one can walk 
on its crust, although the lava just below is at red heat (700°-950° C.) or is 
yet hotter. For many hours or for several days the gradient at the surface 
may equal or surpass 500° C. per foot. 

In the manufacture of calcium-carbide a mixture of limestone and coke 
is submitted to the action of a powerful electric arc. At the end of a fur- 
nace-run (about fourteen hours in the plant at Ottawa, Canada) the flow of 
heat is nearly steady and the temperature gradient in the furnace is about 
3000° C. per foot. In this case the diffusivity of the limestone-coke mixture 
in the interior of the thoroughly heated furnace must ue well below 60 in the 
Kelvin system of units. 


R.A. Daly— Mechanics of L[gneous Intrusion. 28 


Weber has found that # for gneiss at 0° C. is 0:000578 and 
at 100° C. 0:000416, showing a very great lowering with increase 
of temperature.* In fact, through the interval 0°-100° C., & 
seems to vary about inversely as the absolute temperature.t 
If this law should hold to 1100° C. the conductivity of average 
rock at 1100° falls to about 0:001—nearly the value for water, 
which is famous as a poor conductor. 

In the present connection the thermal diffusivity («) of rock, 
rather than its conductivity, is of first importance. If s = 
specific heat and d = density, we have 

seas 

Toe gad 

For rock at room temperature (20° C.) Kelvin assumed 400 as 

the value of « when the unit of length is a foot, the unit of 

time a year, and the unit of temperature one degree Fahrenheit. 

This value is close to that which represents the average of the 

determinations made for different rocks at room temperatures, 
during the years since Kelvin wrote his famous essay.t 

If « be assumed as 400 at all temperatures up to 1300°C., 
it is possible to calculate the temperature gradient in the wall- 
rock of a molten batholith at the end of specified periods of 
time. For practical purposes the surface of contact may be 
regarded as infinite; let it further be considered as plane. 
Under these conditions the following Fourier equation furnishes 
the datum for calculating the temperature at a point x feet 
from the contact at the end of ¢ years.§ Inthe eguation =the 
temperature of the magma; ¢ = the temperature of the wall- 
rock assumed as initially uniform ; and vw = the required tem- 
perature. We have :— 


pa bele 5) = oe” ag 
— —_ ap. 
a 


x : 
For values of SW which are less than 2°6 the value of the 


2 V/ kt 
integral can be readily found from the table of the probability 
integral which appears in standard text-books on the Method of 


* Values taken from Landolt-Bérnstein Phys.-Chemische Tabellen. Forbes 
and Hall have proved analogous relations for iron and for magnesium oxide ; 
ef. J. D. Forbes, Trans. Roy. Soc. Edinburgh, xxiv, p. 105, 1867, and E. H. 
Hall and others, Proc. Amer. Acad. Arts and Sciences, xlii, p. 597, 1907. 

bee eines Tait, Recent Advances in Physical Science, 2d ed., London, 
Pp. <(V, 1570. 

{ Trans. Roy. Soc. Edinburgh, 1882. 

she W. E. Byerly’s Elementary Treatise on Fourier’s Series, Boston, 1893, 
p. 86. 


24 Lf. A. Daly—Mechanies of Igneous Intrusion. 


: a 
Least Squares. For higher values of "e the value of the 
& K 


integral can, in many cases, be computed by developing it into 
a series. Kelvin’s value for « is peculiarly favorable for such 
computation and the corresponding units have been used by 
the writer in the calculations. 

Let 6 = 2200° F. (about 1200° C.); ¢c = 400° F. (about 200° 
C.);¢ = 1, 4, 16, and 100 years; and let « havethe different 
values shown in the left-hand column of the following table 
(1) The corresponding temperatures are shown in the other 
columns. 

TaBLE I.—Showing values of wu when « = 400 and 


er SSS SSS Seas tt rages 
a == teaver. t = 4 years. t = 16 years. t = 100 years - 
Ope 2007 JE 9200° KF. 2200 EY, 2200° F. 
OES 703 1947 DOms 
20. 1263 1703 1947 
4)! 683 1263 1703 
80! 408 5 683 1263 
100’ ca.400 5a] 1078 ; 1703 
NGOs 400 ; 408°5 683 
200’ 400 ca. 400 537 1263 
320’ 400 400 408.5 
400' 400 400 ca.400 683 


The table shows that, at the end of the first year, the temper- 
ature of the rock is but shghtly affected by the magmatic heat 
at a point 80 feet from the contact, and that the temperature 
gradient for the 80-foot shell then averages nearly 23° F. per 
foot. At the end of four years the temperature is but shghtly 
affected at a point 160 feet from the contact and the tempera- 
ture-gradient is about 11° I. per foot. 

But « cannot be nearly so great as 400 in the case before us. 
We have seen that # decreases rapidly with rise of tempera- 
ture in rock. The experiments of Weber, Bartoli, Roberts- 
Austen and Ricker, and Barus show that the specific heat of 
rock averages about ‘180 at 20° C. and increases regularly with 
rise of temperature, so that at 1100° C. the specific heat averages 
about -280.* It follows that thermal diffusivity in rock decreases 
with rising temperature even faster than the conductivity 
decreases. At 1100° C., « may, indeed, be only 

"180 293 1°000 
(oss A393 * Sane =) sa | 
or less than one-seventh, of the diffusivity at 20°C. For rock 
heated to 1000° or 1200° C. « is, thus, probably not much more 
than 60 in the Kelvin system of units. 


* For references see J. H. L. Vogt, Christiania Videnskabs-Selskabets 
Skrifter, I. math.-naturv. Klasse, No. 1, p. 40, 1904. 


, 
R. A. Daly—Mechanies of Igneous Intrusion. 25 


It seems safe to assume, first, that the diffusivity of the 
gradually heated wall-rock may vary from 275 or less to 100 or 
150; secondly, that the average diffusivity of an 80-foot shell 
heated during the first year by adjacent molten magma, will be 
no greater than 200. If « be regarded as averaging 200 for 
all periods greater than one year, the four columns pins 
values of win the table will serve if ¢ is , respectively, 2, 8, 32 
and 200 years. 

As a result of somewhat rigorous calculation, then, it 
appears certain that the heating of wall-rock by plutonic 
magma must progress with great slowness and that the result- 
ing temperature gradient in the shell adjoining the molten 
magma must be steep for many years after the original estab- 
lishment of the contact.* 

Further, Less has proved that rocks have highly variable 
coefficients of conductivity, some species possessing coefficients 
twice as high as those of other species.t It is also well known 
that bedded or schistose rocks conduct heat along and across 
their structure-planes at quite different rates. Where, there- 
fore, the wall-rocks about a batholithic mass are heterogeneous, 
the heat-conduction is variable and expansional stresses must 
ensue. 

A rough calculation of the enormous stresses involved in all 
these processes of differential heating was published in the 
second paper of this series, where .also an account is given of 
the practical use which has been made of such stresses in 
primitive quarrying.t Every great city conflagration leaves 
manifold evidences of the shattering effects of “the one-sided 
heating of a rock-mass—in columns, sills, and cornices of 
oranite or sandstone. 

There seems, therefore, to be a sheer necessity for believing 
in contact-shattering through differential heating and expan- 
sion in the thin shell of a country-rock which encloses a large 
body of molten magma. The evidence for the shattering is 
often exceedingly full and clear in the field. The broad or 
narrow belts of xenoliths so often found just inside the main 
contacts of batholiths are very hard to explain if those batho- 
liths are due to laccolithic injection. The blocks are charac- 
teristically angular; they are generally not arranged with their 
longer axes parallel, as if they had been pulled off from the 

* By using the same Fourier equation it is not difficult to show that the 
loss of thermal energy which a magma suffers by conduction into the 
country-rock is relatively small, even after the lapse of two or three hundred 
thousand years. The long duration of the magmatic period in a slightly 
superheated. plutonic mass of large size becomes easily understood. 

+ Phil. Trans., vol. clxxxiii A, p. 481, 1892. 


t This Journal, xvi, p. 112, 1903; ef. Ann. Rep. State Geologist of New 
Jersey, 1906, p. 17. 


26 R. A. Daly—Mechanies of Igneous Intrusion. 


walls by the friction of the moving magma. On the lacco- 
lithic theory one would expect many of the xenoliths to form 
elongated smears in the granite rock. This is indeed occa- 
sionally seen but most exceptionally; as a rule the xenoliths 
have just that irregularity of form and arrangement which 
they should have if they had been shattered off by the hot 
magma just before its final consolidation. Throughout its 
long, earlier history the magma must, in every case, have had 
a much more effective shattering power. 

It may be noted that the shattering of crystals and rock- 
fragments, when immersed in silicate melts, has often been 
observed.* The strains are, in such cases, necessarily of a 
lower order than those developed on the wall of a batholith 
where, therefore, shattering is even more certainly brought 
about. | 

Relative densities of magma and xenolith.—In his first 
intrusion-paper, the writer published the results of his attempt 
to calculate the possible specific gravities of the chief types of 
molten magmas under plutonic conditions. The calculations 
were based on. Barus’s well-known fusion experiments on 
diabase. The specimen investigated had a specific gravity of 
3°0178; when fused to a glass and cooled to 20° C., a specific 
gravity of 2°717. He further states that the glasst showed 
an expansion of 3°9 per cent in “melting” and, as glass, 
expanded 0:000025 in volume for a temperature rise of 1° C. 
through the interval 0°-1000° C. and 0-000047 in volume for 
1° C. through the interval 1100°-1500°. The “melting” 
expansion (solidification-contraction) and the varying rate of 
expansion (or contraction) above and below 1000° ©. seem to 
show that some crystallization of the melt took place during 
the experiment. Such crystallization was inevitable under 
the conditions of the experiment, in which the cooling lasted 
several hours. , Barus’s curves do not, therefore, show directly 
the volume changes suffered by pure diabase glass in passing 
from the molten isotropic state to the rigid isotropic state at 
room temperature. Excluding the “solidification” contrac- 
tion, the glass loses but 3°5 per cent of its volume in passing 
from the molten state at 1400° C. to room temperature; the 
loss of volume through the same temperature interval was 
calculated in the first paper as about 8 per cent. Barus found 
that the net decrease in specific gravity in passing from rock 
at 20 C. to glass at 20° C. was 10 per cent. For his diabase 
specimen, therefore, the decrease of specific gravity in passing 

* Of. C. Doelter and E. Hussak, Neues Jahrb. fiir Min. etc., 1884, p. 18; 
A. Becker, Zeitschr. d. d. geol. Ges., xxxiii, p. 62, 1881. 


+‘*Throughout this paper the molten rock solidifies into an obsidian.” 
C. Barus in Bull. 103, U. S. Geol. Surv., p. 26, 1893. 


R. A. Daly—Mechanics of Lgneous Intrusion. 27 


from 20° C. to molten condition at 1200° C. is possibly only 
about 13 per cent, instead of about 16 per cent, as noted in 
the first paper.* 

Quite recently J. A. Douglas has made a number of very 
careful measurements of the densities of typical igneous rocks 
and of their respective glasses, all specific gravities being 
taken at room temperatures.t . Douglas’s method is reliable 
and his results accordant. For gabbro he found the decrease 
of specific gravity, in passing from rock to glass, to be 5:07 
per cent. Delesse had found the decrease to be 11°46 per 
cent, as the average of measurements of two specimens from 
different localities Barus’s determination, 10 per cent, is 
intermediate between the two. 

It seems probable, therefore, that a decrease of 6 per cent in 
specific gravity (rock to glass at 20° C.) is close to the minimum 
for the average gabbroid rock, and it is possible that Barus’s 10 
per cent decrease is too high for average gabbro. For present 
purposes it is safer to use the minimum value of 6 per cent. 
Similar minima for diorite (6 per cent), quartz diorite and 
tonalite (7 per cent), syenite (8 per cent) and granite (9 per 
cent) have been estimated from the numerous measurements of 
Delesse, Cossa and Douglas. Each of these rocks certainly 


TABLE IT. 
; Specific gravity of Specific gravity of same rock 
Crystalline rock at when molten at 
(Are a aS TT 
20°C. 1000°C. 1300°C. 000°C. 1100°C. 1200°C. 1300°C. 
E2780" 25737, 2271 2°57 2°56 2°54 2°53 
Sappre (| 2-90 2°83" <2°80.;>- 2°66. 2:65. 2-64-.. -2°63 
and + 3°00 2:92 2°90 2°75 2°74 2-73 2°72 
diorite | 3°10 3°02 3°00 2°84 2°83 2°81 2°80) 
| 3°20 3°12 3°10 2°94 2°92 2°91 2°91 
Quartz-dio- 

rite and 2°70 2°63 - 2°61 2°46 2°45 2°44 2°43 
tonalite 2-80). 2579 2 2561 2°54 2°53 2°51 2°51 
( 260° (2-3 4- 2:52 2°33 2°32 2°31 Trot 
Syenite {2°70 2°63 2°61 2°42 2°41 2°40 2°40 
(2-80 2°73 2°71 2°52 9°51 «950-950 
Granite (2°60 9:54 2°52 Bele ers A229. 2:29 
and 2°10 2°63. 2°61 2°40 2°39 2°39 2°38 
gneiss ZOO G2 fon 2h) 2°49 2°48 2°47 2°47 


* Bischof, in 1841, found that basalt expanded 7 per cent in passing to a 
glass at room temperature, and 10:4 per cent in becoming molten. (Quoted 
from Zirkel’s Lehrbuch der Petrographie, 2d ed., 1893, vol. i, p. 683.) 

+ Quart. Jour. Geol. Soc., xiii, p. 145, 1907. 


28 R.A. Daly—Mechanics of Iyneous Intrusion. 


expands: in the interval 20°-1300° C. as much as 0°000025 vol- 
ume per degree Centigrade. (Barus and Reade—see first paper). 
This average may safely be employed as a means of determin- 
ing the minimum decrease of density which each rock-type 
undergoes in passing into the molten condition. On this basis 
the writer has constructed the preceding table (II), which shows 
the changes of specific gravity at convenient temperature 
intervals. | | 

Table III shows the changes in specific gravity undergone 
by blocks of stratified and schistose rocks (common country- — 
rocks about batholiths), as these blocks assume the tempera- 
ture (1300° C.) of molten magma in which they are immersed. 


TABLE IIT. 
Range of sp. gt. Range of sp. gr. 
at 20°C. at 1300°C. (solid) 
REACISB Geos F2' de tyh eee 2°60—2°80 2°5 2-29-71 
Mica schists | 32 Whe eee Ogos 2°67-3:°00 
Sandstone ks yee we aad 2°20-2°75 2°138-2°67 
Aroulites 2504. eae e 2°40—2°80 - 2°32-2°71 
Pamestone 22% Sac eres 2°65-2'80 2°57-2°71 


It appears from these tables that nearly all xenoliths must 
sink in any molten granite or syenite; most xenoliths must 
sink in molten quartz-diorite, tonalite or acid gabbro. Many 
xenoliths might float on basic gabbro but the heavier schists 
and gneisses must sink in even very dense gabbro magmas at 
1300° C. : 

Giving, then, the highest permissible values to the specific 
gravities of magmas, it is still true that blocks, such as are. 
shattered from the wall or roof of a batholith, must sink when 
immersed in most magmas at atmospheric pressure. As shown 
in the first intrusion paper, the blocks would likewise sink, 
though the magma enveloping them hes at depths of ten or 
fifteen kilometers below the earth’s surface. 

Sinking of the shattered blocks —\t has been objected to the 
stoping hypothesis that the viscosity of granitic magmas is too 
great to allow of the sinking of blocks even much denser than 
those magmas.* This objection has, however, never been 
sustained by definite experimental or field proofs. The xeno- 
liths visible along batholithie contacts have assuredly not sunk 
far from their former positions in wall or roof and the reason 
for this must be sought in the high viscosity of the magma. 
High viscosity is an essential attribute of a nearly frozen 
magma. The phenomena of fractional crystallization and of 
magmatic differentiation unquestionably show that each 


# Of. W. Cross, G. F. Becker, and A. L. Day, Science, xxv, p. 620, 1907, 


PR. A. Daly—Mechanies of Igneous Intrusion. 29 


plutonic magma must pass through a long period of mobility. 
The most viscous of granitic magmas, the rhyolitic, issues at 
the earth’s surface with such fluidity that the rhyolite often 
covers many square miles with a single thin sheet. The 
absolute viscosity of the Yellowstone Park rhyolites must 
have been of a low order when many of these persistent flows 
were erupted.* 

Even granting that the kinetic viscosity of a plutonic 
magia is ; thousands of times that of water, 1t seems inevitable 
that it could not support xenoliths more dense than itself. 
In a few days or weeks stones will sink through, and corks 
will rise through, a mass of pitch, the viscosity of which is 
more than a million of millions of times that of water.t 
Ladenburg has lately shown that small steel spheres will, in a 
few minutes, sink through twenty centimeters of Venetian 
turpentine, a substance 100,000 times as viscous as water.{ 
Ladenburg’s experiments have verified the generally accepted 
equation expressing the rate of sinking of a sphere in a strongly 
viscous fluid : 

2gr (d— a’) 
9 v 


were # = the velocity of the sphere when the motion is steady ; 
g = the acceleration of gravity ; d = the density of the sphere ; 
d@ =the density of the fluid; 7 =the radius of the sphere; 
and v = the viscosity of the fluid. § The equation shows that 
the velocity of sinking varies directly as the square of the 
radius of the sphere. This fact may be correlated with the 
observation so often to be made on granite contacts, that large 
xenoliths are rare. This apparently means that, at the end of 
the shatter-period, the viscosity is truly so high as to allow 
of the smaller blocks bemg trapped at high levels in the 
freezing magma, while the large blocks, with greater velocity, 
shall have sunk into the depths. 


C= 


*See Atlas accompanying Monograph 382 of the U. S. Geol. Survey. 
King described the great rhyolite flows of Nevada as bearing ‘‘ abundant 
evidence of true fluidity at the period of ejection.” U.S. Geol. Explor. 
40th Parallel. Sys. Geol. 1878, p. 616. 

Doelter has studied the behavior of a large number of crystalline rocks 
and minerals during fusion. His results show that the temperature-inter- 
val between the stage of softening and that of notable fluidity averages, for 
the basic rocks, about 50° C., and for the acid rocks, about 90°C. (Tscher. 
Min. u. Petrogr. Mitth. xx, p. 210, 1901.) The interval is not great and it 
certainly seems unsafe to deny that even the most viscous, because cooled, 
lavas were fluid in depth. 

+Jamin et Bouty, Cours de Physique, tome I, 2e fascicule, Paris 1888, 
p. 135; ef. Daniell’s Text-book of the Principles of Physics, 2d ed., London, 
1885, p. 211. 

+t Annalen der Physik, xxii, p. 287, 1907. 

§ Poynting and Thomson, Text-book of Physics, Properties of Matter. 
London, p. 222. 1902. 


30 R.A. Daly—Mechanics of Igneous Intrusion. 


Doelter estimates that the pressure of from 7500 to 11,000 
meters of rocks increases magmatic viscosity no more than 20 
to 80 per cent.* If the increment be anywhere near this 
value we may be certain that the viscosity of superheated, 
plutonic magma is relatively low. Becker has calculated that 
the viscosity, of a Hawaiian basaltic flow, not one of the most 
fluid, was, at eruption, about fy times that of water. The 
more fluid rhyolite flows may have viscosity a thousand times 
greater than that of water. The corresponding viscosities of 
the same magmas when ten kilometers underground may, 
then, be possibly no more than from sixty to fifteen hundred 
times that of water. One must conclude that a xenolith, 
even very slightly denser than such a plutonic magma, must 
sink into it. Since such magmas necessarily cool with extreme 
slowness, there is evidently good ground for believing that 
an enormous amount of solid rock could be engulfed before 
practical rigidity is established. The average xenolith must 
sink in a less dense magma with the viscosity of piteh—yet 
how much more rapidly in magma possessing the low viscosity 
which is postulated in any of the ruling theories of plutonic- 
rock genesis ! 

Problem of the cover.—The stopmg hypothesis presents an 
obvious principal difficulty ; it refers to the apparent danger of 
the foundering of the roofs covering the larger batholiths. 
Under plutonic conditions (at depths of from three to ten 
kilometers) the average molten granite would have a specific 
gravity no higher than 2°40. The average rock of its roof has 

a specific gravity of about 2°70. If, then, through orogenic 
Be ee a large mass of the roof- rock became once wholly 
immersed in the granite, it would not only founder itself but 
through subsequent buckling the whole roof might collapse 
and founder in sections. Such a catastrophe has almost cer- 
tainly not happened in the case of any Paleozoic or later 
batholithic intrusion. This difficulty has been emphasized by 
Barrell, who has justly given it a prominent place in his 
monogr ‘aph. + Lawson speaks of batholiths 100 miles in diam- 
eter and also finds the necessity of explaming their roof- 
support as a principal ground of unfavorable criticism.¢ 

The present writer cannot claim to have solved this problem, 
but he does not find it to form a fatal objection to the hypo- 
thesis. In the first place, it seems clear that all the other 
hypotheses of granitic intrusion are facing the same dilemma. 
All of them expressly or tacitly postulate some degree of 
fluidity in each granitic mass as it either replaces or displaces 

* Physikalisch-chemische Mineralogie, Leipzig, p. 110, 1905. 
TOR gcitL <p: sina. 
tScience, xxv, p. 620, 1907. 


R. A. Daly—Mechanics of Igneous Intrusion. 31 


its country-rocks. We have seen that, though the viscosity of 
such a magma may be several hundred times that of water, the 
roof-sections, once immersed, must sink in the magma. All 
petrologists who believe in magmatic or other differentiation 
as operative in batholiths must face the common difficulty. 

Secondly, the writer has shown reasons for believing that the 
earth’s crust at present rests on a continuous couche of basaltic 
(gabbroid) magma, either quite fluid or ready to become fiuid 
when injected nto the crust. If the average specific gravity 
of the crust is 2°75 (a probable value), it would as a whole be 
quite able to fat on the basaltic couche, which, as noted in 
Table IJ, would probably have a specific ovavity over 2°90. 
Imperfect as the numerical data are, we seem justified in con- 
eluding that the earth’s crust is now, as a whole, in stable 
flotation.* 

It may have been entirely different in pre-Keewatin (earliest 
Archean) time when the superficial, acid couche of the primi- 
tive earth began to solidify. Then foundering may have taken 
place, as Kelvin imagined, and the early formed crusts could 
have sunk a score of kilometers or more until they met the 
denser couche below. Possibly some of the complexity of the 
pre-Cambrian formation may be referable to this unstable con- 
dition of the early crust. Already in Keewatin times the acid 
shell was solidified and was then penetrated by basaltic injec- 
tions which reached the surface, forming the heavy masses of 
greenstones belonging to that period. Since then the crust 
has remained essentially coherent, and through it the primary 
basalt has, at many times and places, been erupted. It is, 
however, quite possible that the lack of system among the 
axes of the Laurentian batholiths and the abundance of those 
batholiths are both explained by the thinness and weakness of 
the crust in post-Keewatin and pre-Cambrian time. 

For Paleozoic and later batholiths there is a well-defined 
law that they have penetrated the crust only on the sites of 
folded geosy nelinals, and that the larger batholithie axes are 
usually arranged parallel to the respective geosynclinal and 
mountain-range axes. 

In other words, the intrusion-history of the globe may be 
conceived as divisible into three epochs: the first being that 
in which the outer primary shell was becoming stable through 
successive solidifications and founderings ; the second being 
the post-Keewatin (Laurentian) epoch of very general inter- 
action between the fluid basaltic substratum and acid crust, 
without extensive founderings but with development of many 
large, irregularly occurring ‘batholiths ; the third, a period of 
the localization of batholiths in certain mountain-built belts, 


* For a further discussion of this point see this Journal, xxii, p. 201, 1906. 


32 R.A. Daly—Mechanics of Igneous Intrusion. 


where alone there seems, in this third period, to have oceurred 
the injection of molten magma in masses of batholithie size— 
in no known ease accompanied by wholesale foundering. 

Again, granting the hypothesis that a visible post-Archean 
batholith is the acidified, upper portion of a basaltic body 
originally injected to a level less than about ten or fifteen | 
kilometers from the earth’s surface (perhaps the level of no 
strain), it is not difficult to see that extensive foundering may 
be impossible. Only after some differentiation or acidification | 
of the primary magma would any part of it become less dense 
than the average roof-rock. Xenoliths of the heavier gneisses 
and schists would, however, sink. When dissolved m the pri- 
mary magma their material—added to that dissolved along the 
main contact-surfaces—would lower the density and maugu- 
rate the stage of general stoping. Only when the resulting 
syntectic magma has been formed in large amount is there 
any danger of roof-foundering. But it is evident that, in the 
process of dissolving the engulfed blocks, the magma is losing 
heat. In every post-Archean batholith the magma, because of 
exhaustion of the heat-supply, seems to have been arrested in 
its upward course at average distances of one or more kilo- 
meters from the earth’s surface. The syntectic magma, less 
dense than the roof-rock, is thus necessarily of limited depth. 
That depth represents the thickness of the couche which 
endangers the stability of the roof. Jf, now, we imagine the 
buckling of the roof with the complete immersion and sinking 
of certain parts of it, the foundering must be limited by the 
width of the injected body (seldom over fifty kilometers) and 
by the thickness of the acid couche (ten kilometers or less). 
Extensive floods of rhyolite and allied rocks may have issued 
at the surface in consequence of partial foundering (faulting), 
but great crustal catastrophes involving large areas would not 
be expected. | 

Finally, it should be noted that post-Archean granitic intru- 
sions have regularly followed periods of prolonged orogenic 
crushing, during which accumulated tangential stresses are | 
effectually relieved. As the magmas work their way up into 
the folded terranes there is relatively little chance for the 
buckling of the roof. Until it is buckled and immersed in the 
magma it cannot sink. Now the heat of the magma, though 
it shatters the roof-rock at the immediate contact of solid and 
fluid, must tend to expand the roof, tighten it, prevent normal 
faulting and so strengthen the roof. The cover of the batho- 
lith is thereby kept in an exceptionally rigid condition. Its — 
strength is, initially, that of a domed shell spanning diameters 
not very many times the thickness of the shell. The strength 
is increased, as with the groined roofs and arches of Gothic 


R. A. Daly—Mechanics of Lgneous Intrusion. 33 


architecture, by the presence of roof-pendants ; and by thermal 
expansion, the whole is strongly knit together. Immersion 
and foundering of roof-sections may, therefore, not have been 
possible in the case of post-Archean batholith or stock. 
__ In spite of the highly theoretical nature of some of the 
foregoing argument, it appears to the writer to carry weight 
enough to warrant our regarding the difficulty im question as 
not destructive of the stoping hypothesis. The problem needs 
further study in connection with this and all other conceptions 
of granitic intrusion. 

Supply of the necessary heat ; magmatic superheat and its 
‘causes.—W hether the observed aver age temperature gradient 
within the earth’s crust is to be explained as due to original 
heat (inherited from an early epoch in the development of 
the earth either from a gaseous or planetesimal nebula), or 
whether the gradient is due to the evolution of heat with the 
preak-up of radium and other radio-active substances, are gen- 
eral questions not immediately affecting the stoping hy poth- 
esis. We need go no further back in the thermal problem 
than to secure an estimate of the minimum temperature of the 
primary magma when abyssally injected and thus prepared tor 
stoping and assimilation. ‘This estimate is evidently not easy 
to make. A rough idea of the probable temperature may be 
obtained by deductively considering the temperature gradient 
or, secondly, by assuming that the “jnitial temperature of the 
abyssally injected basalt is not far from that of the hottest 
basaltic lava known in voleanoes. | 

The first method is only applicable on certain assumptions 
as to the thermal and material constitution of the basaltic sub- 
stratum. It is first of all assamed that the substratum, though 
a true basalt for many kilometers of depth, is faintly stratified 
according to density differences. The chemical contrast 
between successive shells of the substratum may be extremely 
slight and yet sufficient to prevent convection-currents, even 
though the bottom shell of the substratum is several hundreds 
of degrees hotter than the uppermost shell. A rise in temper- 
ature of four hundred degrees involves an expansion ot only 
about one per cent in volume. An underlying couche of 

basalt at 1600° C. would, therefore, if its specific gravity at 
—1200° C. were 2°93, not ‘convectively displace an overlying 
couche of magma at 1200° C. and with a specitic gravity of 
2°90. Such faint density stratification, if assumed, goes far to 
explain the general stability of the earth’s crust and so far is 
in accord with the facts of post-Archean geology. This con- 
ception also involves the possibility that the observed temper- 
ature gradient continues without important change, deep into 


Am. Journ. Sci1.—FourtH Series, VoL. XX VI, No. 151.—Juty, 1908. 
3 


34 LR. A. Daly—Mechanics of Igneous Intrusion. 


the substratum. It is here also assumed that the gradient, 
3° C. for 100 meters of descent, applies to the crust and to 
the upper part of the substratum at least. It must be noted, 
however, that the gradient may very considerably steepen in 
the depths, because of the fact that the thermal conductivity 
and diffusivity of rock both decrease in large ratio with increase 
of temperature. The amount of steepening of the gradient is 
unknown, but our ignorance on this point is unessential to the 
principle of the following argument, in which the normal gra- 
dient is assumed throughout. | 

Thirdly, it is assumed that, under normal conditions, the 
substratum shell immediately below the solid crust is not super- 
heated but is at the melting-point of basalt at that depth. The 
accepted temperature gradient gives, at the depth of 38 kilo- 
meters, a temperature of 1140° C. Vogt has calculated that 
the pressure at this level raises the melting-point about 50° C. 
Since basalt at atmospheric pressure is just melted at about 
1190° C., we may conclude that the bottom of the crust, in 
accordance with the assumptions, averages 38 kilometers below 
the present surface. If the earth is cooling down, the crust 
was evidently somewhat thinner during Tertiary and pre- 
Tertiary batholithic intrusion. 

If, now, a broad geosynclinal prism of sediments, 10,000 
meters thick in the middle, is laid down on the site of 
a future mountain-range, the isogeotherms must rise. The 
uppermost layer of the substratum, where most deeply 
buried, will thus tend to assume a temperature of nearly 300° 
C. above normal. If the sedimentary prism be folded and. 
overthrust as in the usual large-scale orogenic disturbance, the 
substratum below the mountain-range may be still more effeet- 
ively blanketed, with a further rise of the isogeotherms. 
Quickened erosion may, however, largely offset this thickening 
by the mountain-building process, and it would be unsafe to 
postulate a total rise of temperature of more than 300° C. in 
the substratum of the area. Part of this superheat is lost by 
conduction into the crust, the lower basic part of which may 
be thus melted. An unknown but possibly considerable frac- 
tion of the total superheat may remain in the original substra- 
tum, and this amount of superheat would characterize the 
basalt when rapidly injected into the crust. | 

In the partial release of pressure in the act of injection we 
have another, but probably less important, source of super-- 
heat—averaging some fraction of the 50° C. by which the 
melting-point is raised at the bottom of the 38-kilometer crust. 
A third source of superheat is found in the conversion into 
heat of the mechanical energy necessary for injecting a viscous 
melt into an opening cavity. 


kin A, Daly— Mechanics of Lgneous Intrusion. 35 


These three sources of superheat would alone furnish enough 
thermal energy to raise the injected basaltic magma from 1140° 
C. to some temperature short of 1500° C. or 1600° C. 

The piling up of 10,000 meters of lava over a large area 
would have an analogous superheating effect on the substratum. 
This conclusion enables us to give some explanation of the fact 
that the lavas of Kilauea and Mauna Loa seem to be the 
hottest known in any voleanic vent. The vast Hawaiian lava- 
plateau has, apparently, been built up by the comparatively 
rapid effusion of basaltic flows from Pacific depths averaging 
6,000 meters to heights above sea of about 4,000 meters: The 
unique lava-fountains of the calderas, while showing obvious 
evidence of considerable superfusion, are described as glowing 
mie white heat.’ *~ It a correct description, this implies a 
temperature of 1300° O. or possibly 1400° C.¢ Such temper- 
ature must be a minimum for the substratum which feeds the 
ealderas, where there is continuous loss of heat in the convec- 
tively stirred lava. 

Speculative argument and limited observations in nature 
agree, then, in fixing some such temperature as 1300° C. as a 
minimum for the basaltic mass injected into the crust-rock 
below a great mountain range. 

Capacity of superheated, plutonic magma for melting and 
dissolving xenoliths.—Basalt must have a thermal capacity 
much like that of diabase at the same temperature. Barus’s 
experiments show that the average specific heat of diabase for 
the interval 1300-1140° C. is °350.¢ The heat-energy contained 
in the substratum, if it be superheated 160° C. above its 
melting-point (1140° C©.), is in excess of that contained in the 
substratum just above its melting point by (160 °350=) 55+ 
gram-calories. 

This surplus heat-energy is available for the fusion and 
assimilation of country-rock. There are good reasons for 
believing that the average wall-rock of oranite batholiths has 
the composition and erystallinity of a eranitoid eneiss. For 
purposes of calculation this will be assumed to be the fact. 
The average temperature of the wall-rozk before an abyssal 
intrusion may be conservatively estimated from the normal 
temperature gradient to be 200° C. In order to raise the 
gneiss to the temperature of 1200°, where it is just molten, 


* J. D. Dana, Characteristics of Voleanoes ; New York, 1891, p. 200. 

+ LeChatelier and Boudouard’s High Temperature Measurements; New 
York, 1904, p. 246. 

¢ C. Barus, op. cit., p. 58. For the interval 100-20° C. the mean specific 
heat is about ‘185. There is, in fact, a steady increase in the mean value 
as the temperature of any silicate or silicate mixture rises. This fact goes 
far to explain the prolonged liquidity of assimilating magmas. Cf. J.H.L. 
Vogt in Christiania Videnskabs-Selskabets Skrifter, math-natury. Klasse, 
1904, No. 1, p. 40. 


36 P sdeara be Daly—Mechanies of Igneous Intrusion. 


\ 


about 410 calories (assuming latent heat at 90 calories—a value 
estimated by Vogt for the silicates) per gram must be supplied 
from an outside source. If all the superheat of the basalt 


‘ : : : ; 55 
were available for melting (not dissolving) gneiss, ao of mass- 


unit of gneiss would be melted by mass-unit of the superheated 
basalt; or about 7°5 mass-units of the basalt would melt a mass- 
anit of wall-rock. 

Such simple melting would, however, not occur. There 
are plenty of field and “laboratory proofs that molten basalt, 
even slightly superheated, will dissolve fragments of onelss and 
allied rocks. The mutual solution of two contrasted silicate 
mixtures takes place at a certain temperature which ‘is lower 
than the melting poit of either one. The simple contact of 
two such materials suffices to cause their mutual solution at 
that lower temperature.* This fundamental law of physical 
chemistry has been experimentally demonstrated for silicates 
by Vogt and by Doelter and his pupils, although the last men- 
tioned authors have, perhaps, not sufficiently regarded the fact 
that it takes considerable time for the mutual solution to take 
place.t 

Petrasch has experimentally shown that, when two parts of 
limburgite and one part of granite are mixed and heated, they 
melt together at 950° ©. and the solution remains fluid down 
to 850° C.t Predazzo granite softens at 1150° ©.) andesite 
limburgite at 995° C.§ In this case, there is a lowering of 
200°—3800° below the melting-point of granite and 45°-145° C. 
below that of limburgite. 

It seems highly probable, thus, that gneiss-xenolith and 
basalt would form a solution or syntectic film which is molten 
at a temperature at least 50° C. below the fusion-point of basalt 
at the average depth of ten kilometers or less below the earth’s 
surface. At those depths basalt melts at about 1100° C.; the 
syntectic would be molten at or below 1050° C. If the syntec- 
tic film were continuously removed during the sinking of the 
block or by the currents inevitably set up during stoping, 


*Cf. O. Lehmann, Wiedemann’s Annalen der Physik, vol. xxiv, p. 17, 
1885. 

+See J. H. L. Vogt, Christiania Videnskabs-Selskabets Skrifter math. - 
naturv. Klasse, 1904, No. 1, p.191; and Tscherm. Min. u. Petrogr. Mitth., 
xxiv, p. 473, 1906. . 

+ K. Petrasch, Neues Jahrb. ftir Min., etc., Beil. Bd. xvii, 1903, p. 508. 
Petrasch mixed the powders of one part of granite (softens at about 1150° C.) 
with two parts of hornblende-andesite (softens probably about 1050° C.) and 
found the mixture to become molten at 900° C., proving again an important 
lowering of the melting-point below that of either rock. Basic rock thus 
acts as a flux for granite (or gneiss) to an extent comparable with that 
proved by Petrasch and others for lithium chloride, calcium fluoride, ammo- 
nium chloride, sodium tungstate, ete. 

$C. Doelter, Tscherm. Min. u. Petrogr. Mitth., xx, 1901, p.:210. 


Lt. A. Daly—Mechanics of Igneous Intrusion. 37 


nearly all of the superheat of the basalt might be used in dis- 
solving the gneiss. The total melting-heat of eneiss, if molten 
at 1050° ©., would be-.about 400 calories. The heat-energy 
required for the solution of one gram of the gneiss which has 
an original temperature of 200° C. is (400—40=) 360 calories. 
The heat- energy given off by one gram of basalt in cooling 
from 1300° to 1050° ©. is about (250 x 840 =) 85 calories. 
One gram or mass-unit of gneiss would, then, be dissolved by 


) 4-3 grams or mass-units of the primary basalt, pro- 


vided all the thermal energy were used for solution. 

These various calculations are obviously very erude. They 
take no account of conduction of heat away from the batho- 
lithic mass, nor any account of possible exothermic or endo- 
thermic chemical reactions between basalt and wall-rock ; nor_ 
any account of the influence of water, chlorides, etc., derived 
from the geosynclinal rocks which are assimilated.* These 
substances held in the magmatic solution tend to lower the 
solidification point of the syntectic. The result of the caleu- 
lation would also be affected if we assume that. the heavier 
xenoliths, would sink to levels where the temperatures are 
above 1300° C. Finally, the result would be different if we 
postulate that the invaded formations, through the crushing 
incident to orogenic movement before the intr usion, had been 
heated above 200° C. Without “here entering on the disens- 
sion of these further complications, we may conclude that 
probably from four to six volumes of the superheated primary 
basalt would furnish the heat-energy necessary for the solution 
of one volume of. wall-rock. 

If this rough estimate is even approximately correct, we 
have some idea of the actual assimilating power of plutonic 
magma which has been superheated a couple of hundred 
degrees. We also see a definite reason for the fact that post- 
Archean granites have never, so far as known, stoped their 
way to the earth’s surface. The crust has been too thick, the- 
expenditure of heat-energy in forming the syntectic magma 
too vast, that the process could operate to its extreme and so 
endanger the stability of the crust-roof. above each batholith. 

Objection founded on rarity of evidences of assimilation at 
observed wall-rocks.—One of the most commonly expressed 
objections to any theory of the replacement of invaded for- 

* According to the stoping hypothesis almost all of the heat conducted 
into the shells of country-rock successively stoped away during the mag- 
matic period, is not lost, but is available for the abyssal assimilation of the 
engulfed blocks. In view of the slowness with which the mixtures of pow- 
dered silicates melt, it is probable that notable exothermic reactions do not 


take place. 'The possibility of endothermic reactions seems to be a more 
open question. 


38 RL. A. Daly—Mechanics of Igneous Intrusion. 


mations by batholithic magmas consists in emphasizing the 
obvious fact that the average xenolith and average wall-rock 
of batholiths do not show direct evidence of melting or of 
solution in the granitic magma. This objection has been 
answered by the writer in several publications* and also by 
Andrews in most vivid fashion.t The point has, however, 
been restated by several authorities without any adequate dis- 
cussion of the subject. No onecan deny that, when the magma 
is all but frozen, it is incapable of assimilating xenolith or 
wall-rock on any large scale. The practical question is as to 
the magma’s efficiency during the long antecedent period of its 
history. It is true that bed-ridden centenarians did not build 
the pyramid of Cheops; it does not follow that men did not 
build it. 

' If it be assumed that the quartz of granite has crystallized 
at or below 800° ©.,{ it follows that complete rigidity is not 
established in a granite batholith until it has cooled to at least 
800° C. Down to about that temperature limit (of undercool- 
ing), therefore, magmatic stoping is still possible. The lowest 
limit of active assimilation cannot well be much below 1000° C., 
while the temperature required to melt the average xenolith 
is about 1200° C. As the viscosity of granitic magmas increases 
greatly below 1200° C., diffusion and convection must become 
rapidly inadequate to remove syntectic films at main contacts, 
so that the molecular lowering of the fusion-point will be con- 
fined, within the interval 1200°-800° C., chiefly to the sunken 
blocks. It follows, first, that in the very long period of time 
occupied in the cooling of a plutonic mass from 1200° C. to 
800° C., there will be little or no melting or solution of wall- 
rock ; secondly, that many shells of roof-rock, perhaps aggre- 
gating thousands of feet in thickness, may be stoped away 
during that same period of time. In other words, because the 
shatter-period is longer than the period of active assimilation 
at the roof, it is an essential feature of the stoping hypothesis 
‘that neither visible xenolith nor main wall of a granite batho- 
lith should normally show a collar of assimilation. So far 
from being a difficulty, the fact that this is generally true is a 
distinct argument in favor of the stoping hypothesis. 

Abyssal assimilation.—In the first paper of this series the 
writer stated grounds on which one must believe in the com- 
plete solution of engulfed xenoliths. One has only to imagine 
a block of gneiss, say ten meters in diameter, sinking through 
a column of superheated basalt twenty or thirty kilometers 

*This Journal, xv, p. 281, 1903; Bull. Geol. Soc. of America, xviijyp: 
372, 1906. 

+ Records, Geol. Surv. of N. S. Wales, viii, Pt. 1, p. 126, 1905. 


tCf. A. L. Day and E.S. Shepherd, Jour. Amer Chem. Soc., xxviii, p. 
1099, 1906. 


Re. A. Daly—Mechanies of Igneous Intrusion. 39 


deep, to become convinced of the ultimate fate of that block. 
If the somewhat cooled lavas described by Lacroix,* von John,+ 
Dannenberg,} Sandberger§ and others could dissolve rock- 
inclusions in the notable way described by those authors, we 
must credit a vast solutional efficiency to plutonic magma 
when it attacks similar blocks in great depth. The lava has a 
few hours or days in which to do its work ; the abyssal magma 
has centuries if not a large part of a geological period ! 

It must be remembered that geosynclinal sediments are 
rocks unusually rich in water, chlorides, sulphur trioxide, ete. ; 
all substances aiding solution in the primary magma and in 
the secondary (syntectic ) magma itself. It is probably also 
owing to these fluids in large ‘part that granitic magmas have 
crystallized at comparatively low temper ‘atures. 

The conception of stoping with abyssal assimilation has many 
more points in its favor than can be cited for pure marginal 
assimilation. A few of the special grounds for preferring 
the newer to the oider hypothesis may ‘be noted. 

First, marginal assimilation is largely effective only in the 
earliest part of the magma’s history, when it is absolutely and 
relatively very hot. There is thus an early time-limit fixed 
for the gigantic work of dissolving the thousands of cubic kilo- 
meters actually replaced in the intrusion of a large batholith. 

Secondly, the assimilation, on the older view, takes place 
‘primarily on main contacts and along a relatively limited 
amount of surface. or example, a cube of wallrock one kilo- 
meter in diameter can offer only about 1,000,000 square meters 
of surface at a time to the dissolving magma. If that same 
. cube were shattered into cubes 10 meters on the side and then 
engulfed, the magma would carry on the work of solution on 
600,000,000 square meters of surface. 

Thirdly, the average crust-rock being allied chemically to 
gneiss, is more soluble in basic magma than in acid. On the 
stoping hypothesis, solution of the xenolith generally occurs in 
the lower, basic part of the magmatic chamber; on the older 
view, it is granitic magma which must do most a: the work of 
solution. For even if the originally injected magma is a 
basalt, the products of its assimilating activity, being more 
acid and less dense than itself, must remain at the batholithic 
roof and rapidly assume the chemical composition of mean 
mountain-rock. It follows that the primary magma must be 
enormously more superheated than is required on the stoping 
hypothesis or than seems easy of explanation, in view of the 


* Les Enclaves des Roches Volcaniques, Macon, 1893. 

+ Jahrb, d. k. k. Reichsanstalt, Vienna, lii, p. 141, 1902. 
¢{Tscherm. Min. u. Petrogr. Mitth., xiv, p. 17, 1895. 
$Sitzungsber. K. Bair. Akad. Wiss., p. 172, 1872. 


40 R. A. Daly—Mechanics of Igneous Intrusion. 


difficulty of understanding how plutonic magma, which is 
capable of intrusion, can become superheated more than two 
or three hundred degrees Centigrade. 

Fourthly, the stoping hypothesis has the special advantage 
of providing a mechanism of thorough agitation within a bath- 
olith. Strong stirring of the mass is induced by the sinking 
of xenoliths and by the necessary rising of the magma locally 
acidified by their solution. This agitation can explain the 
marvelous homogeneity in each large batholith. It helps 
greatly to explain the manifest evidences of magmatic differ- 
entiation within batholiths—splittings and segregations that 
cannot be due to the slow process of molecular diffusion or to 
mere thermal convection. The whole process of stoping and 
the rising of syntectic magma tends to equalize the temper- 
atures in the batholithic chamber and thereby we can under- 
stand the even grain and rapid, nearly simultaneous ecrystalli- 
zation of a batholith throughout its visible depth. 

Fifthly, the engulfment ‘of blocks of geosynclinal sediments 
enriches all parts of the batholiths with water, chlorides, ete. 
which so greatly aid solution ; while, on the older view, these 
agents are confined to the uppermost part of the chamber. 

Sixthly, as already noted, the cleansing of syntectie films 
from contact of solid and hquid is much the more rapid and 
pertect according to the stoping hypothesis, thus providing 
and renewing conditions for molecular lowering of the fusion- 
point along contacts. 

In short, the newer view has the advantage of not only 
better explaining the facts of the tield but it is incomparably 
more economical of the heat postulated for the work of bath- | 
olithic replacement than is the theory of pure marginal assim- 
lation. Melting and marginal assimilation of country- -rock 
takes place in the initial, superheated condition of a basaltic 
injection, but must be regarded as always subordinate in replace- 
ment efficiency to stoping and abyssal assimilation. 

Existence of basic stocks and batholiths—¥inally, the faet 
that some large bodies of plutonic rocks are basic has been 
advanced as an objection against the idea of stoping.* This 
fact early impressed itself on the present writer and led to his 
reviewing the geological literature to determine, if possible, 
the number, distribution, and age of these bodies. It was 
found that most of those which have undoubtedly batholithie 
development on a large scale are of pre-Cambrian age and 
are chiefly anorthosite intrusions. In this Journal, vol. xx, 
1905, p. 216, the guarded suggestion was made that the anor- 
thosites of Canada and the Adirondack Mountains are so basic 
because of the absorption of crystalline limestones. On more 


* W. Cross in Science, xxv, p. 620, 1907. 


R. A. Daly—Mechanics of Igneous Intrusion. Al 


mature consideration this suggestion seems inadequate and a 
more general explanation must be sought. 

Adams describes the great anorthosite mass of Morin, Que- 
bee, as genetically associated with an adjacent gabbro body of 
batholithic size.* The one is either a differentiate from the 
other or both are expressions of a common basic magma. The 
latter seems the more probable relation. In fact, both batho- 
liths appear to represent the crystallized products of a magma 
allied to, if not identical with, the primary basaltic magma 
which has been the source of the heat in post-Archean batho- 
lithic intrusions. 

The conditions of intrusion for these ‘upper Laurentian ”’ 
masses seem to have differed from those typically represented 
in the post-Cambrian batholiths. The latter have been devel- 
oped under heavy geosynclinal covers which have entailed 
considerable superheat in the basaltic substratum. It is not 
impossible that the “upper Laurentian” basic magmas, already 
cooled nearly to the solidification-point, were injected into the 
then thinner crust, or warped up with it, during crustal dis- 
turbance. Lacking superheat these magmas lacked stoping and 
assimilating power and, consequently, did not become aciditied. 

In favor of the conception that these magmas were near 
the solidification point at the time of their intrusion, is the 
fact that the anorthosites often show primary banding and are 
most extraordinarily granulated, as if by dynamic force which 
acted on the congealing mass near the close of the intrusion- 
period. Concerning the granulation Adams writes: “There 
are no lines of shearing with accompanying chemical changes, . 
but a breaking up of “the constituents throughout the whole 
mass, though in some places this has progressed much further 
than in others, unaccompanied by any alteration of augite or 
hypersthene to hornblende, or of plagioclase to saussurite ; 
these minerals though prone to such alteration under pr essure 
remaining quite unalter ed, suffering merely a granulation with 
the arrangement of the gr anulated material in parallel strings. 
This process can be observed in all its stages, and there is 
reason to believe that it has been brought about by pressure 
acting on rocks when they were deeply buried and very hot. 
The anorthosite areas, of which there are about a dozen of 
great extent with many of smaller size, are distributed along 
the south and southeastern edge of the main Archean protaxis 
from Labrador to Lake Champlain, occupying in this way a 
position similar to that of volcanoes along the edge of our 
present continent.” + 


* Canadian Record of Science, 1894-5. 
+F. D. Adams, Jour. of Geol., i, p. 334, 1893. 


42 de Ale, Daly—Mechanies of Igneous Intrusion. 


Cushing and Kemp have published somewhat detailed 
accounts of the anorthosite for ming a post-Grenville and Be 
Cambrian batholith and its satellitic stocks in New York state.* 
The batholith covers about 3000 square kilometers in area. 
Cushing’s petrographical descriptions show many points of 
agr eement with Adame’s description of the yet vaster Canadian 
batholiths. The anorthosite generally crystallized with excep- 
tionally coarse grain and a porphyritic structure. Intense 
granulation is here again the rule, and from Cushing’s pub- 
lished data it seems probable that the granulation followed 
hard after the act of intrusion. The characteristics and_field- 
relations of the anorthosite are such as to suggest that they 
have resulted from abyssal injections of magma which was not 
superheated. A limited amount of stoping is possible in such 
amagma but extensive assimilation of country-rock is not 
possible for that magma. 

Kemp has suggested that the New York anorthosite has, 
through fractional crystallization and the settlement of the 
basic minerals of early generation, been derived from a normal 
gabbro. | This idea may possibly explain the existence of the 
more pyroxenic \contact-phase regularly occurring in the bath- 
olith. The contact rock is either gabbro or anorthosite-gabbro. 
It may represent the original magma but little affected by the 
settlement of the erystals of iron-ore, pyroxene and olivine. 
In the more slowly cooled interior of the mass their settlement 
could take place on a large seale.{ In the Canadian batholiths 
this differentiation by fractional crystallization may have 
occurred just before the huge iiasses were injected into the 
crust. 

The problem of the anorthosites is clearly as yet one for 
speculation rather than one capable of final.solution. It seems 
proper to believe, however, that, since all or nearly all of the 
known anorthosite and gabbroid batholiths are of pre-Cambrian 
age, they owe their origin to special pre-Cambrian conditions. 
The stoping hypothesis as a whole expressly relates only to 
conditions which have characterized orogenic belts in post- 
Archean time. 


*H. P. Cushing, 18th Report of the State Geologist, Albany, p. 101, 1900; 
New York State Museum Bulletin No. 95, p. 305, 1905, and Bull. 115, p. 471, 
1907. J. F. Kemp, 19th Ann. Report, U. 8. Geol. Surv. pt. 3, p. 409, 1899. 

Op Cis. 1p) 417; 

t Incidentally it may be remarked that the same conception might con- 
ceivably explain many internal basic contact-phases occurring in acid stocks 
and batholiths. This explanation isevidently opposed in principle to the 
prevailing view that the basic contact-shel's are due either to diffusion of 
basic molecules toward cooling-surfaces, or to the combined influence of 
fractional crystallization and convection-currents in the magma. Neither 
of these hypotheses seems acceptable in the case of the anorthosite-gabbro 
batholiths, and the writer has come to question their validity as final 
explanations for some other types of intrusive bodies. 


RR. A. Daly-—Mechanies of Igneous Intrusion. 43 


The gabbros of Paleozoic or later age represent bodies either 
too small or of too low temperature to carry on extensive stop- 
ing before their magmas became rigid. Diorite stocks and 
batholiths, according to the hypothesis, represent undifferen- 
tiated or but par tially differentiated syntectic magma—of com- 
position intermediate between rhyolite or granite and_ basalt. 
The average chemical analyses of the world’s basalt, granite 
and diorite have been calculated by the writer from Osann’s 
compilation.* It has been found that the diorite analysis is, 
oxide for oxide, almost the exact mean between the other two 
analyses. 

These various considerations incline the writer to the view 
that the existence of a few iarge basic intrusions, cutting acid 
rocks, is not necessarily a fact fatal to the stoping hypothesis. 
Each of the cases needs special study, for they may shed much 
light on the difficult plutonic problem. 

Differentiation of the syntectic maugma.—In order to trace 
further the history of the engulfed xenoliths several principal 
conditions must be recognized. If the invading magma is 
superheated, so as to have the temperature of 1300° ga 
block of heavy gneiss (sp. gr. at 20° C., 2°85) will speedily be 
heated to and above its own melting-point. While some of it 
is dissolved, much of it is converted into a molten globule of 
essentially pure gneiss. From Table II we see that the 
specific gravity of the globule would be about 2°40, while that 
of the surrounding primary magma would average about 2°72. 
This difference of density means that the globule must rise 
through the primary magma with a speed even greater than 
that with which the solid rock (specific oravity about 2°75) 
formerly sank.t As it rises the globule would wholly or 
partly mix with the primary magma. If wholly mixed the 
primary magma rapidly becomes a “syntectic magma, approach- 
ing a diorite in composition. The molecular, syntectic film 
which is formed by solution along the surfaces of the block 
must, theoretically, contain equal parts of primary magma and 
xenolith material. If the former be basalt and the latter a 
granitoid gneiss, the film must have a dioritic composition. 
‘All three kinds of secondary magma—molten globules of 
gneiss, globule-material dissolved in primary magma as the 
globule rises, and the material formed in the molecular, syntec- 
tie film—must be. considerably less dense than the primary 
basalt and rise toward the top of the batholith chamber. <A 
net result of abyssal assimilation is a compound, secondary 
magma either dioritic or more acid than diorite. 

* Beitraige zur Chemischen Petrographie, II Teil ; Stuttgart, 1905. 


+ The same reasoning applies to xenoliths of normal gneiss immersed in 
acidified gabbro or diorite magma. 


t+ Rt. A. Daly—Mechanies of Igneous Intrusion. 


This reasoning is deductive but it can in some measure be 
checked by actual observations. Lacroix describes blocks of 
gneiss up to a cubic meter in size, which have been immersed 
in molten basalt. By the heat of the lava the blocks have 
been “entirely transformed” into porous glass.* Von John 
has described other examples of the same transformation.t 
The present writer has correlated a considerable number of 
instances where the gravitative stratification has certainly 
been produced in thick intrusive sheets. i 

A number of observers have come to the conclusion that 
the very act of the assimilation of acid material by basalt predis- 
poses the magma to magmatic splitting. The fullest statement 
of this view is given by Loewinson-Lessing, in his remarkable 
“Studien tiber die Eruptivgesteine.”§ There appears to be, 
as it were, a steady “‘antagonism ” between the ferromagnesian 
and acid-alkaline élements in magmas. This primordial tend- 
ency toward immiscibility may well explain the dominant 
acidity and alkalinity of the pre-Cambrian terranes in every 
continent. From the earliest times the granito-rhyolite magma 
has tended to separate from the basaltic wherever the viscosity 
has been sufficiently low for such splitting. For similar 
reasons it appears that the syntectic magma of post-Archean 
batholiths only reaches a stable condition when it assumes the 
ancient relation. In the average case the fluidity has been 
high enough for the splitting. In some cases, however, it was 
so low that the undifferentiated syntectic has crystallized as 
diorite and allied rocks. 

When the syntectic has differentiated, the process must be 
primarily controlled by density, so that the acid, generally 
granitic, product rises to the top of the chamber. There it 
may become locally further differentiated through fractional 
crystallization or other relatively subordinate process. 

Without discussing the causes of differentiation in more 
detail, it suffices to point ont, in summary, that magmatic stop- 
ing involves the placing of gravity at the head of the’list of 
forces which produce the actual diversity amoug igneous 
rocks. In this the stoping hypothesis is believed to. match the 
facts observed in experimental, industrial and geological 
studies of silicate melts. 

Origin of granite; the petrogenic cycle.—The stoping 
hypothesis involves a more or less definite corollary relating 


*TLes Enclaves des Roches Voleaniques, p. 063-5; Macon, 1892. 

+ Op, cit., sp. 1AL. 

{This Journal, xx, p. 185, 1905: also Festchrift zum siebzigsten Geburts- 
tage von H. oe abiiceh: p. 203, Stuttgart, 1906. 

$ Comptes Rendus, Congres eéol. internat, Vile session, St. Petersburg, 
p. 375, 1899. 


PR. A. Daly— Mechanics of Igneous Intrusion. 45 


to the genesis of granite as the staple visible material of post- 
Archean batholiths. Erosion has nowhere penetrated more 
than a few thousand meters in any of these batholiths. Con- 
sidering the scale of operations, it follows that practically all 
post-Archean batholithic rock is of secondary origin. The 
field-relations show that the granite often replaces much geo- 
synclinal sediment. Thick as many geosynclinal prisms are,. 
however, it seems clear that another lar ge, perhaps the lar ver, 
part of the replaced rock may be pre-Cambrian crystalline 
materials (averaging granitoid gneiss in chemical composition) 
which underhe seosynclinal areas, as they apparently underlie 
all the continental areas. The similarity of granites throughout 
the world may, indeed, be explained by the uniformity of the 
earth’s primordial, acid shell and by the relative uniformity in 
average chemical composition of the greater geosynclinal prisms. 
Where sediments only are assimilated, the secondar y granite 
may be of abnormal composition ; this is the case with the 
granite of the Moyie Sill.* 

The longer an abyssaily injected and assimilating body holds 
its fluidity, the more. perfect should be the oravitative differ- 
entiation. During this active stage lateral fissures or laccolithie 
spaces may be filled with offshoots of the slowly changing magma. 
In general these satellitic injections should succeed each other 
in the order of increasing acidity. In a fully represented 
petrogenic cycle at a batholithic area, then, the oldest intru- 
sion should be a rock of gabbroid (basaltic) composition and 
the youngest an acid granite (chemically a rhyolite or quartz 
porphyry). Between these two an indefinite number of inter. 
mediate rock-types varying according to their degree and kind 
of differentiation from the syntectic—itself continuously vary- 
ing in composition—might ‘be represented in dikes or other 
satellitic forms. This further deduction from our hy pothesis 
seems to be fairly matched by the observed order of igneous 
intrusions about the world’s batholiths.+ 

Again, successive batholithic intrusions in the same area 
should show the same law of increasing acidity with decreas- 
ing age. If, for example, a crystallized gr anodiorite batholith 
be itself attacked by a later abyssal intrusive and in large part 
stoped away and remelted, the ‘secondary magma collecting at 
the roof of the later batholith should be more acid than 
granodiorite. This would be expected because the mere act 
of remelting entails further gravitative differentiation. Each 
time that a silicate mass passes through the optimum tempera- 
ture for magmatic splitting —probably an interval of one or 


* This Journal, xx, p. 196, 1905. 
+ See first intrusion paper, p. 292. 


46 RR. A. Daly—Mechanies of Igneous Intrusion. 


two hundred degrees above its melting point*—the separation 
of its acid-alkaline and ferromagnesian elements by gravity is. 
further perfected. Morozewicz has given a telling experi- 
mental demonstration of the process. He melted two pounds 
of granite and left the superheated melt in a hot part of an 
active glass-furnace for five days. It was:then cooled to a 
_glass. "At the end of the time he found that the lower part 
of the melt carried 59°20 per cent of silica, the upper part 
73°65 per cent; the original granite showed 68°9 per cent.t 
An actual case of repeated differentiation of the kind seems 
to be represented in the Okanagan Mountain range, where, one 
after another, the Osoyoos-Remmel, Similkameen and Cathe- 
dral batholiths have been intruded, and clearly in the order of 
decreasing specific gravity of the rocks.¢ 

It is, however, to be expected, on the stoping hypothesis, 
that the primary basaltic magma may close an entire petro- 
genic cycle, since the latest phase of a batholith, after crystal- 
lizing, may be fissured and injected with a small volume of 
the substratum. The common occurrence of diabase or pro- 
phyrite dikes in granite may be thus explained. 

Origin of magmatic water and gases.— Finally, the stoping 
hypothesis implies that, since post-Archean batholiths have 
generally replaced large volumes of sediments, the volatile 
matter which is normally trapped within a ceosynclinal prism 
should form an important part of the secondary magma. 

An approximate idea of the amount of volatile matter in 
the average argilliteS, sandstone and limestone of the world is 
readily obtained. For this purpose we may use Clarke’s com-. 
posite analyses of 843 limestones, 624 sandstones, 27 Mesozoic 
and Cenozoic shales and of 51 Paleozoic shales, together with 
38 analyses of various argillites from different parts of the 
United States.| From these analyses the writer has deter- 
mined, for the argillites, the average amount of water below 
110° C. (H,O—), water above 110° C. (H,O+), carbon dioxide, 
earbon (and carbonaceous matter), and sulphur (Gin SQ,). 
These averages represent, respectively, 116, 116, 106, 78 and 
78 typical specimens of argillite from as many localities. The 
averages for sandstone and limestone have been taken directly 
from Clarke’s work and all three sets are noted in the follow- 
ing table: 

An inspection of the table makes it clear that the total of 
the “‘combined water’, carbon dioxide, carbon and carbona- 
ceous matter, sulphur and chlorine in the stratified rocks 

* F. Loewinson-Lessing, op. cit., p. 380. 

+ Op. cit., p. 2382. C£. C. Doelter, Pepomeneaie Braunschweig, p. 79, 1906. 

t Bull. Geol. Soe. America, xvii, p. 329, 1906. 


§ The term “‘argillite” here includes both shales and slates. 
| F. W. Clarke, Bull. No. 228, U. S. Geol. Surv., p. 20 ff., 1904. 


R. A. Daly—Mechanies of Igneous Intrusion. AT 


TABLE IV. 

843 624 116 

limestones sandstones argillites 

i Dies "26% "29% 1°25% 
5 AC SaaS ee ciara i Wise 141 3°71 
lag 38°03 2°64 2°45 
C} (including carbon- } 9 sae 81 

aceous matter) | i, 

So Sat a a ay "03 "25 
woe tp GREENS IO tea =O1 trace trace 
MP otalls se Soe ke ai 39°14 4°37 ES 47 


exposed in any geosynclinal prism must represent at least six 
per cent of the whole mass. It is highly probable that this 
minimum amount of volatile matter has similarly characterized 
such a series ever since the period in which the series was 
deposited. 

No petrographer needs to be reminded that none of the com- 
moner types of igneous rock contains anything like six per 
cent of original volatile matter. Nevertheless it is instructive 
to survey the facts actually visible in quantitative analyses of 
the igneous rocks. Water is the only volatile substance 
determined in igneous-rock analyses often enough to afford 
nearly reliable world-averages. From Osann’s compilation 
the writer has deduced the average of H,O— and H,O+ for 
each of the following groups: 48 granites, 47 diorites, 12 gab- 
bros, 24 basalts, 5 angite andesites and 11 rhyolites (Vable V). 


TABLE V. 

H,O— H.O+ 
SARE 1h eae eg ae, aed 17% 64% 
Wile 2 tees oS 19 ri e20 
Gabbro 2 2a or eee en OG 1e35 
Pras. mee eee eo ates he. 1°03 
Augite-andesite _. ---- AO Bi Ge 1°48 
tivo tec Sls. "30 1°23 


Clarke’s averages for the volatile substances occurring in 
igneous rocks which have been analyzed according to approved 
methods are: 


LCT Ae EGE: Sc an epee neces aes 40% 
LAG ea ANE Snes a eget 1°46 
SEG Mee Se a EET SORE Se ee 52 
ie Pane re ee a ne a 
CR Ae eee SMT ON ate A 07 
Peep peers Se es oe 02 


Much of the combined water, probably all of the hygroscopic 
water, and most of the carbon dioxide of these analyzed igne- 
ous rocks are due to alteration or to absorption at the earth’s 
surface. Allowing for that fact, it seems probable that none 
of the more widely distributed igneous rocks carries much more 


* Includes organic matter. 


~ 


48 R. A. Daly—Mechanies of Igneous Intrusion. 


than one per cent of its own weight in volatile matter directly 
derived from the earth’s interior. | 

It follows that an enormous amount of water, carbon diox- 
ide and carbon and sulphur compounds may be given off each 
time that geosynclinal sediments have been assimilated by 
molten and then crystallized magma. From each eubie kilo- 
meter of assimilated sediments about six per cent by weight 
of liquids and gases must be dissolved in the syntectie magma 
and, as crystallization proceeds, a large part of this fluid must 
be expelled. 

In less important degree we may expect that the remelting 
or solution of an igneous rock by an intrusive magma should 
cause the evolution of some of the fluid matter which had 
been, as it were, frozen into the solid rock. Lincoln has aptly 
ealled such fluids ‘repressed emanations.”*  Gautier’s and 
Brun’s experiments show that many and probably all igneous 
rocks give off gases on being highly heated.t Reheating 
atter cooling causes the renewed emanation of gases. Volatile 
matter trapped’ in crystallized secondary granite may thus be 
driven off, if that granite be dissolved in a younger molten 
magma with subsequent crystallization of the syntectie. 

The stoping hypothesis in its broadest statement demands, 
therefore, that post-Archean, batholithic granites, syenites and 
diorites should be accompanied by special evidences of fluid 
emanations. 

These fluids were deposited and buried in the strata. They 
have been resurrected in their activity. They have “risen 
again”, both literally and figuratively ; they may be called 
“resurgent” emanations. The ‘repressed’? emanations: of 
secondary igneous rocks may similarly be lberated by the 
distilling action of younger magma; as these fluids become 
revivified in their geological activities they may be regarded 
as forming a second kind of “resurgent” emanations. All 
“resurgent” emanations are of secondary origin and, therefore, 
stand in contrast to ‘“ juvenile” emanations, namely, those 
which, for the first time, have issued from the earth’s interior 
and become ceolovically active on or near the surface. Mag- 
matic emanations are, apparently, divisible into two great 
classes, both of which should be recognized in complete discus- 
sions of ore-deposits. 

That the stoping hypothesis stands this further test seems to 
the writer entirely clear. The prevalence of quartz veins and 
pegmatites in the walls and roofs of actual granitic, syenitic, 
and dioritic stocks and batholiths, and the intensity of the 
contact-metamorphism produced by the intrusions of, and 
especially the emanations from, these rocks are facts as famil- 


*¥F. C. Lincoln, Economic Geology, ii, p. 268, 1907. 

+A. Brun, Archives des Sciences Phys. et nat. Geneva, May and June, 
1905 and November, 1906; A. Gautier, Annales des Mines (6), ix, p. 316, 
1906, and Econ. Geol., i, p. 688, 1906. 


RR. A. Daly— Mechanics of Igneous Intrusion. 49 


jar as the comparative rarity of quartz-veins and pegmatites 
about gabbroid masses and the comparative feebleness of the 
contact-metamorphism produced by gabbros. The abundant 
water found in obsidian and rhyolite is, in this view, largely 
or wholly of secondary origin. Volcanic gases may similarly 
be largely “resurgent” rather than “juvenile.” In no ease, 
however, would one class of emanations be represented to the 
exclusion of the other: For ae -Archean granites the emana- 
tions are dominantly “resurgent”; for gabbros the emanations 
are largely or dominantly “ Fajenile? 

Conclusion.—The tirst two papers of this series were writ- 
ten in the light of experimental results bearing on the methods 
of igneous intrusion. Since 1905 a number of additional 
leading experiments according to refined methods have been 
earried out by Doelter and his colleagues, by the Geophysical 
Laboratory staff at Washington, by Brun, Gautier, Hall, Doug- 
las, Ladenburg and others. These later investigations, like 
those of Deville, Bischof, A. Becker, Lehmann, Fouqué, 
Michel Lévy, Cossa, Thoulet, Barus, Oetling, Hofman, Tam- 
mann, Mor ozewicz, Forbes, Joly, Mallet, Reade, Cusack, 
Weber, Akerman, Vogt, Bartoli, Jamin, Lagorio, and others, 
seem to show that the physical conditions and processes 
involved in the stoping hypothesis have been in the main 
correctly stated. 

It is obvious that further laboratory study of rocks on the 
physico-chemical side is highly desirable, but the accordance 
of independent experimental results now on record appears to 
have demonstrated : first, the enormous efficiency of thermal 
expansion in causing shattering stresses in solid rock ; secondly, 
the fact that the average xenolith must sink in molten or anite, 
syenite, diorite aud acid gabbro when these magmas are under 
ordinary plutonic conditions ; thirdly, that the sunken xeno- 
liths must melt or become dissolved in the depths of plutonic 
magma, forming syntectic magma; and fourthly, that, if the 
primary magma is basic, the average syntectic must rise through 
it and thus collect at the top of the magmatic chamber. 

The attempt has been made, in using the experimental 
results of Barus, Roberts-Austen and Riicker, Weber, Bartoli, 
Akerman and Vogt, to estimate the amount of average crust- 
rock (gneiss) which may be dissolved in one volume of super- 
heated primary magma (basalt). The sources of superheat in 
plutonic magma and a rough quantitative analysis of abyssal 
assimilation have been discussed. The result’ points to an 
explanation of the fact that magmatic stoping has not destroyed 
the roofs of post-Archean batholiths. The more general prob- 
lem of the stability of batholithic covers which, on any the- 
ory of magmatic intrusion, seem to be in danger of foundering 


Am. Jour. Sci.—FourRtTH Beds VoL. XXVI, No. int ae 1908. 
4 


50 RL. A. Dalty—Mechanics of Igneous Intrusion. 


in the less dense magmas, is seen to have become less serious 
as that problem is viewed in the hght of the new estimates of 
magmatic density. The possibility that some of the Archean 
batholiths were the scenes of actual, partial foundering of ie 
earth’s crust had been noted; the suggestion is made “that, 
late pre-Cambrian time, it had become thick and strong ohne 
to inhibit extensive foundering of batholithic covers. 

Various objections to the hypothesis seem to fall away so 
soon as they are confronted by the facts of experimental inves- 
tigation on melted rocks and silicate mixtures. Other objec- 
tions have been met by the facts derived from the field-work 
of many observers. The facts of field-oceurrence and field- 
relations are opposed to the “ laccolithic theory ” and to that 
of marginal assimilation; on the other hand, these facts all 
seem to be explicable on the stoping hypothesis, which, there- 
fore, is taken by the writer to afford the best working basis 
for the future investigation of granitic batholiths. In this 
conelusion the writer is in full agreement with Andrews and 
Barrell, two authorities who, with the intrusion-problem 
expressly in mind, have carefully scrutinized actual batholiths. 

The hypothesis involves several important consequences, a 
few of which have been considered. If magmatic stoping 
and abyssal assimilation have largely operated during the 
intrusion of post-Archean batholiths and stocks, it follows that — 
the material of these bodies is largely or wholly of secondary 
origin. In each case it is a differentiate from a syntectic 
magma formed by the solution of primary (acid) crust-rock or 
of geosynclinal sediments in the (probably basic) magma of the 
substratum. The order of eruption in batholithic areas, with 
respect to the acidity of the rocks, need not be absolutely 
fixed, but should show a strong tendency toward the succes- 
sion of eruptives becoming more acid with decreasing age. 
Lastly, since most post-Archean granites have replaced large 
volumes of sedimentary rock, the suggestion seems war ranted 
that the water and other volatile matters regularly given off in 
great volume from granitic magma, are also of secondary ori- 
gin. Geosynclinal sediments are normally charged with rela- 
tively abundant fluids ; it seems inevitable that these should, 
in part at least, be given off during the solution of wall- rock 
or engulfed xenoliths in an invading magma. 

The principal field-relation on which the for egoing discussion 
hangs is the “replacement” of country-rock by magma in the 
intrusion of stock or batholith. Slow digestion and solution 
on main contacts has caused the replacement to a limited 
degree, but the facts of nature seem to enforce belief in 
the more rapid and more important mechanical replacement 
through magmatic stoping. 


F. B. Loomis—Rhinocerotide of the Lower Miocene. 51 


Arr. 1V.—Phinocerotide of the Lower Miocene; by FRED- 
ERIC B. Loomis. 


Formerty the Lower Miocene beds of America were 
considered by vertebrate paleontologists to be practically 
barren of vertebrate fossils; but three years ago Mr. Peter- 
son opened in them the Agate Spring quarries from which 
have been taken literally hundreds of skulls and disassoci- 
ated skeletons, among which two species of rhinoceros of the 
htherto rare genus Diceratherium are far the most abun- 
dant. In the “breaks” of the neighboring hills scattered 
remains have also been found, and it was the fortune of the 
Ambherst ’96 expedition, during the summer of 1907, to find a 
small pocket of rhinoceros bones some 300 yards north of the 
above mentioned quarries. These latter remains are remark- 
able in that they represent seven different rhinocerine species 
all buried together. Four of the species are new and as they 
represent some unexpected phases, they are not only described, 
_ but a broad study of the whole group in the Lower Miocene 
is here undertaken. While with the three new species added 
in this paper, thirteen species of Diceratherium are now 
known, the genus has never been carefully studied, partly 
because the early species assigned to it were never figured and 
were with difficulty accessible. For this paper the Yale 
Museum has allowed the study of the Marsh material and the 
figuring of his types, which were but | 
briefly characterized. The following ~ 1 
paragraphs will therefore consider the 
genus Diceratherium, as to its char- 
acteristics, distribution and the sys- 
tematic relations of its species. The 
Aceratheria of the Lower Miocene will 
also be described, as the genus has not 
previously been found in the Amer- 
ican strata later than the Oligocene. 

The genus Diceratherium was estab- 
lished in 1875 by Marsh for the species Fic.1. Diceratherium nio- 
D. armatum,* its distinctive feature 5'"ese P. ; second upper 

- ; : molar, one-half nat. size. 
being the presence of a pair of horn Key to terminology: a. pre- 
cores on the nasal bones. While the fossette; b, med. fossette ; 
animal was rather long-limbed and light © crochet; ¢, metacone; e, 

; : 3 metaconute; f, postfos- 
built, as the skeletal material is mostly sette: g, hypocone ; h, cin- 
disassociated no attempt will here be gulum; 7, protocone: j, 
made to discuss this part of the skele- protoconute; %, paracone ; 
ton. The teeth vary considerably, the eae ee 


* This Journal, vol. ix, p. 242, 1875. 


52. Ft. B. Loomis—Rhinocerotide of the Lower Miocene. 


earlier forms from the John Day beds showing but little com- 
plication; but with the advance of time the erochet and 
crista develop, and increase progressively until they meet and 
isolate the median fossette. The premolars of any jaw grade 
in their characters unto the molars, but there is a tendency for 
the premolar to attain any feature earlier than the molar. 
The upper canine is wanting but that of the lower jaw is 
moderately developed, having a triangular cross section. The 
incisors are reduced to +, the upper one being elongated and 
oval in section as in Aceratherium, while the lower incisor is a 
mere button-like rudiment. The first lower pyewno.a is 
usually wanting; so that the generic dental formula is 1 2 4 2. 

It is in the John Day beds of Oregon that the first Dicer- 
atheres are found, full fledged as to the nasal horn cores; but, 
were only the dental series of such a form as ). armatwm con- 
sidered, the simple cross ridges and well developed cingulum, 
would proclaim it an Acerathere. On the other side the spe- 
cies Acerutherium tridactylum from the Protoceras beds has 
a pair of low roughened bosses on either nasal bone seeming 
to indicate incipient horns. This species was considered by 
Hatcher* as already a Dicerathere, but Osborn places it among 
the Aceratheres, where the writer would leave it, as the form 
still has the second upper incisor and the more dolicocephalie 
type of skull which characterizes the Aceratheres. However, 
it is,as Osborn indicates, closely related and probably ancestral 
to the Diceratheres, the White River Aceratheria being the 
stock from which the genus Diceratherium arose. The John 
Day species (especially D. armatwm) are very Acerathere-like, 
in the strong development of the cingulum and the absence 
or weak development of the crochet and crista. The Euro- 
pean species are likewise among the less specialized members 
of the genus; but they are differentiated by the strongly pro- 
jecting pr otoconule fold, which has sometimes been described 
as an “antecrochet.” It seems to the writer simply an enlarge- 
ment of the protoconule region, and is characteristic of both 
D. minutum (=crozierr) and D. douvillez, and also of the 
American species D. hesperiwm ; so that these three species 
make a convenient and related sub- group. The later American 
forms from the Lower Harrison beds all have crochet well 
developed, D. nzobrarense being the simplest of them, and 
having an aspect very suggestive of the John Day phase. The 
other species have a crista, which the crochet tends to meet. 
On the wall of the crochet away from the median fossette are 
often tiny ridges which give the enamel a characteristic wavy 
appearance. ‘The latest species known is D. oregonensis, in 
which the crochet and crista are broadly united. 


* Amer. Geologist, vol. xx, p. 313, 1897. 


F.. B. Loomis—Rhinocerotide of the Lower Miocene. 58 


During Oligocene times the country west of the Great Lakes 
and either side of the Canadian line seems to have been teem- 
ing with Aceratheres, abundant in numbers and varying in 
characteristics. At the end of the Oligocene all but a remnant 
of this rich fauna disappeared, its descendants in Eur ope still 
flourishing while but a handful still held on in America, as will 
be shown later. Why the disappearance is unknown. Directly 
succeeding these Aceratheres, it now appears that the Dicera- 
theres flourished, apparently as rich in numbers and in species. 
While longer limbed and somewhat shorter headed, the den- 
tition forbids any thought that these were open country crea- 
tures. There are no nibbling teeth and the backs of the canines 
are worn as when branches are stripped of leaves by drawing 
them through the mouth. The grinders are also those of a 
brouser. Spreading westward and northward, these Dicera- 
theres crossed the Berings isthmus and reached Ger many and 
France, there to become in a short time extinct. In America 
they multiplied in Lower Miocene times, and in the Harrison 
period no less than five* species were ranging over Nebraska 
and Wyoming. In their turn the Diceratheres as mysteriously 
wane and die out, the last one known being only indicated by 
a single tooth from the Upper Miocene of Oregon. 

Throughout the genus, the size and shape of the nasal horns 
-vary In any species with the age and sex of the individual. 
Variation is also characteristic in the weight and stockiness of 
the skull as a whole. In all features there is that tendency to 
fluctuation which is found in a young and developing group, 
the different species representing apparently points in evolu- 
tionary lmes. Some of the species can be gathered into sub- 
groups on common features which repr esent common descent, 
but there are still many gaps to be filled before a perfect case 
of adaptive radiation will be illustrated. The characters which 
have proven most satisfactory for establishing species are, after 
size and contour of the skull has been considered in a general 
way, the pattern of the premolar and molar teeth. 

In the following descriptions the Osborn nomenclature has 
been used, a key to which is given in fig. 1, p. 51. The figures 
are all one-half natural size except fig. 10. Further measure- 
ments are given in the table at the end of the descriptions of 
the genus Diceratherium. 


Diceratherium armatum Marsh. 
This Journal, vol. ix, p. 242, 1875. 
The type is No. 10,003 in the Yale Museum, a complete skull 


somewhat crushed dor so-ventrally, from ‘near John Day River 
in Eastern Oregon.” 


* Probably as many more will turn up within a few years, judging from 
the variation of toe bones and other of the less characteristic features. 


dt Ff. B. Loomis—Rhinocerotide of the Lower Miocene. 


Thus, the largest species of the Diceratheres is characterized 
by the simplicity of the dental pattern, the crista and the 
crochet being absent on the second and third molars, and only 
the crochet faintly indicated on the first molar. The premolars 
are without the crochet but have the crista incipient. Around 
the premolars the cingulum is well developed along the front, 


2 


Fic. 2. Diceratherium urmatum M.; premolars and molars of type speci- 
men, one-half nat. size. 


baek and internal face of the tooth; but in the first molar it 
is interrupted opposite the protocone and hypocone. 

As noted above, in the simplicity of the dental pattern and _ 
in the development of the cingulum, D. armatum shows a 
strong affinity to such Aceratheres as A. trzdactylum and A. 
occidentale. | 


Diceratherium annectens Marsh. 
This Journal, vol. v, p. 4, 1873. 


The type is No. 10,001 of the Yale Museum from the “ John 
Day valley, Oregon.” The type is composed of the incisor, 
first and third premolars, and the first and second molars, of 


= Fie. 5. Diceratherium annectens M.; third premolar, first and second 
molar of type specimen, one-half nat. size. 


the upper right jaw, apparently all belonging to one individual. 
Of these the second molar is marked “type,” but the others 
are included in the description. 

This small species is readily distinguished by the fact that 
on the molars the protoconule and the hypocone are so closely 


F.. B. Loomis—Rhinocerotide of the Lower Miocene. 55 


placed that on a partly worn tooth they actually join and the 
intervening valley between the protoloph and the metaloph is 
interrnpted. The crochet is only incipient; and the crista, 
while wide, is not prominent. The cingulum is well developed 
in front and behind, but internally is wanting except for a 
trace between the protocone and hypocone. 


Diceratherium nanum Marsh. 
This Journal, vol. ix, p. 248, 1875. 


The type is No. 10,004 in the Yale Museum from the John 
Day River in eastern Oregon. The specimen is the front of a 
skull including the upper and lower incisors, the lower canines 
and the first three upper and lower premolars; all however 
worn to the roots, so that the dental pattern is obliterated, and 
the only available character is size. In this it agrees closely 
with D. annectens. 


Fic. 4. Diceratherium nanum M.; incisor and first three upper premolars 
of the type, one-half nat. size. 


Diceratherium hesperium Leidy. 
Proc. Acad. Nat. Sci., Phila., p. 176, 1860. 


The type in this case is a lower molar from the John Day of 
Oregon. Later to this, Leidy assigned some further frag- 
mentary material, in which was a third upper molar, which is 
so far the only distinctive specimen. The lower molar used as 
type is intermediate between D. armatum and D. annectens, 
and while it will never be certain that the assigned specimens 
are the same species, there seems to be a distinct species of this 
size, which they may well typify. The features of the third 
upper molar* are that the protoconule and the metacone are 
much swollen, and there is a small tubercle in the valley 
between the protocone and the hypocone. 


Diceratherium pacificum Leidy. 
Proc. Acad. Nat. Sci., Phila., p. 248, 1871. 
This type is again fragmentary material from the John Day 
of Oregon. Here the first molar tooth described is a second 
upper molar from the right side, which indicates a well marked 


* See Rep. U. S. Geol. Surv. Terri., vol. i, pl. ii, fig. 8. 


56 #. B. Loomis —Rhinocerotide of the Lower Miocene. 


species, characterized by the presence of two moderate crochets, 
and two strong eriste. Thecingulum is well developed both 
in front and along the internal face of the tooth. 


») 
Zs 
Z 


At 
= 
—~S 


an 
(; 


ZHAN 


Fic. 0. Diceratherium hesperium ; after Leidy, one-half nat. ‘size. 
Fic. 6. Diceratherium pacificum iby ; the second upper molar, after Leidy, 
one-half nat. size. 


The writer will be surprised if the second tooth assigned to 
this ee by Leidy* does not prove to belong to some as yet 
undescribed species. The entire lack of crista and crochet 
would ‘debar it from belonging to this species. 


Diceratherium niobrarense Peterson. 
Science, vol. xxiv, p. 281, 1906. 


Type is No. 1,271 in the Carnegie Museum, a nearly perfect 
skull from the Lower Harrison beds of Agate Spring nt Ys 
Sioux Co., Nebraska. 

The species is characterized by moderate size, the skull 
being relatively narrow and high, with a compar atively small 
brain case. The occipital crest is high, and joined by a strong 
sagittal crest formed by the union of the ridges from over the 
orbits. The nasal bones project consider ably beyond the horn 
cores: the orbit is large; and the wide zygomatic arches are 
heavy. Of the teeth the premolars have preserved the cin- 
gulum intact along the inner face, and are without either cro- 
chet or crista. The molars are in like manner primitive, having 
the internal cingulum only slghtly interrupted opposite 
the hypocone, while the crista is wanting and the crochet quite 
moderate in development. As noted by Peterson, the species 
resembles DY. armatum of the John Day and is probably a 
direct derivative of that form, having advanced in the moder- 
ate development of the crochet and in the skull becoming nar- 
rower and higher. In size it is about 4/5 as large as YP. 
armatum. See fig. 1 on page 51, and for further figures 
see Peterson.t 

* See Rep. U. 8. Geol. Surv. Terri., vol. 1. pl. ii, fig. 7 
+ Ann. Carnegie Museum, vol. iv, p. 46, 1906. 


co | 


Or 


F. B. Loomis—Rhinocerotide of the Lower Mio 


Diceratherium petersoni sp. nov. 


Type is No. 1,583 in the Amherst College Museum, being 
the first and second u pper molars, found in the Lower Harrison 
beds, 300 yards north of Agate Spring Quarry, Sioux Co., 
Nebraska. Named for Mr. 0. A. Peterson, who has made the 
Lower Harrison fauna, especially the Diceratheres, famous. 


~ 
‘ 


Fic. 7. Diceratherium petersoni ; first and second molars (type specimen), 
one-half nat. size. 


The species is the largest of those from the Lower Harrison 
and closely approximates D. armatum in size. The anterior 
cingulum is reduced and the internal one absent except for a 
trace between the protocone and the hypocone on the first 
molar. The crochet is strongly developed but not united to 
the distinct, though small, crista. In specialization this species 
is intermediate between LD). niobrarense and D. schiff. 

While no skull was found, numerous seattered teeth were 
collected. 


Diceratherium schiffi sp. nov. 


Type is No. 1,042 in the Amherst College Museum, being an 
incomplete skull, including the right upper premolar and molar 
dentition together with the. entire brain case, from the Lower 
Harrison beds, 300 yards north of Agate Spring Quarry, Sioux 
Co., Nebraska. The species is named to honor Mr. M. L. 
Schiff, one of the supporters of the expedition on which the 
type was found. 

The species is the smallest and most specialized of the genus 
so far found. The low flat skull has an unusually wide ‘brain 
case. The occipital crest is low and the ridges from over the 
orbits fail to unite in a sagittal crest, but remaining wide apart 
in both young and old individuals, cause the flat dorsal surface 
between the orbits to extend back to the rear of the skull. 
The orbit is large, and the zygomatic arch moderate both in 
weight and width. On the premolars the internal cingulum is 


58 FF. B. Loomis—Rhinocerotide of the Lower Miocene. 


incomplete. The crochet and crista are united, thus isolating 
the median fossette, and on the outer face of the crochet wall 
are tiny ridges which gave a crenulated appearance to the 
enamel wall when worn. On the molars the anterior cingulum 
is weak, the internal one wanting, and that on the posterior 
border is raised. While the crochet is large, it does not unite 


Fie. 8. Diceratherium schiffi ; left upper premolar and molar series of the 
type; one-half nat. size. 


with the moderate crista. The species has affinities with D. 
cooki, but is smaller and of lighter build; has a wide flat skull 
in contrast to the high and narrower one of JD. cookt. It 
has also the crista better developed. 

In the experience of the Amherst part this was the common- 
est species, there being in the collection three incomplete 
skulls and several jaws. 


Diceratherium cooki Peterson. 
Science, vol. xxiv, p. 281, 1906. 


The type of the species is a skull in the Carnegie Museum, 
from the Lower Harrison beds of the Agate Spring Quarry, 
Sioux Co., Nebraska. 

The heavily built skull is relatively short and high, with a 
high occipital crest and a moderate sagittal crest formed by the 
confluence of the two ridges from over the orbits. The orbit 
is small, and narrow zygomatic arch of moderate weight. The 
nasal bones do not project in front of the horn cores, but end 
abruptly, giving the skull a very characteristic appearance. On 
the premolars, the cingulum is greatly reduced; while the 
strong crochet unites with the feeble crista, thus isolating the 
median fossette. In like manner on the molars, the cingulum 
is reduced to traces on the front, inner side, and rear of the 
teeth. The crochet is very large and the crista weak, but the 
two do not unite. 

As noted above, this species resembles in dentition D. schzfi, 
but has a shorter and higher skull, with a sagittal ridge, where 
the latter has a broad flat area. The crochet is larger and the 
erista weaker than in D. schiff. 


F. B. Loomis—Rhinocerotide of the Lower Miocene. 59 


Diceratherium aberrans sp. nov. 


Type No. 1,321 in the Amherst College Museum, a single 
tooth, being either the first or second upper right- hand molar, 
from the Lower Harrison beds near Agate Spring Quarry, Sioux 
Co., Nebraska. While a single tooth is undesirable for a type, 
this is so aberrant and specialized that the writer feels bound 
to call attention to it. 


Fie. 9. Diceratherium cooki P.; a second upper molar, one-half nat. size. 
Fie. 10. Diceratherium aberrans ; type specimen, nat. size. 


The small tooth is considerably longer than wide, which is 
unusual among the Diceratheres. Its cingulum appears as 
remnants along the front and inner faces. The striking fea- 
ture, however, is the development of the crista until it almost 
equals in length the protoloph, having on its anterior side a 
strong crochet-like process. In like manner the crochet 1s 
developed to enormous size, and extends to the crista though 
it does not unite with it. The oreat development of these two 
usually moderate processes spreads the protoloph and ee 
wide apart, causing the considerable lengthening of the tooth 


Diceratherium minutum Cuvier = D. Croizeti Pomel. 
See Osborn, Bull. Amer. Museum Nat. Hist., vol. xiii, p. 237, 1900. 


This form from France and Germany is one of the simpler 
types of the genus, and occurs in the Upper Oligocene appar- 
ently equivalent to ‘the John Day. On both molars and pre- 
molars the internal cingulum is greatly reduced, and the 
crochet is but little developed, while on only unworn teeth 
can any crista be detected. The region of the protoconule 
is much swollen, making a fold which is very characteristic 
of the European forms and has been termed an“ antecrochet,” 


though the writer cannot feel that it is the true one. 


Diceratherium douvillei Osborn. 
Bull. Amer. Museum Nat. Hist., vol. xiii, p. 239, 1900. 


A second European species from the Lower Miocene (Burdi- 
galian) of France. It is differentiated by Osborn by its size, 


60 F. B. Loomis—Rhinocerotide of the Lower Miocene. 


the well-developed crochet, no crista, and a large “ antecro- 
chet,” this being as above the swollen protoconule fold. This 
and the foregoing s species are closely related to each other and 
represent the European invasion of these American Dicera- 


i 12 


Fie. 11. Diceratherium minutum ; second molar, after Cuvier, one-half 
nat. size. 

Fie. 12. Diceratherium douvillei ; second molar, after Osborn. 
theres. The two species with their swollen protoconule folds 
show also relationship to the little known D. hespervwm. 


Diceratherium oregonense Marsh. 
This Journal, vol. v, p. 5, 1878. 


The type is a broken molar tooth from the Loup Fork of 
Oregon. This very much worn tooth shows the continuation 
of the features of D. schiffi and D. cooki, the crochet having 
united with the crista and thus isolated the en fossette. The 
internal cingulum is well developed. This is the latest known 
Dicerathere, and in all probability the genus became extinct 

during early Loup Fork times. 


13 Beside the rich fauna of Diceratheres, 
two Aceratheres have been found within 
the past year in these Lower Harrison 
beds; a matter of considerable interest, 

as it has heretofore seemed that except 
for the species of Aceratherium which 
migrated to Asia and Europe, the genus 
had died out in America. It now ap- 
pears, however, that a few forms main- 
tained themselves in this country at least 
as late as the Lower Miocene. The two 
Fre. 18. Diceratherium species show but slight modification from 
aed ed . DEODEBIy their Oligocene progenitors, as will be 
molar 2, one-half nat. seen from the following descriptions and 
size. figures. 


Aceratherium stigert sp. nov. 


Type is No. 1,040 in the Amherst College Museum, a skull 
lacking only a part of the occipital crest and the premaxillee, 


F. B. Loomis—Rhinocerotide of the Lower Miocene. 61 


from the Lower Harrison beds, 300 yards north of Agate Spring 
Quarry, Sioux Co., Nebraska. The specific name is given to 
honor Mr. W. D. Stier, an earnest promoter of the expedition 
on which the type was found. 


Fic. 14. Aceratherium stigeri; the premolar and molar series of the type 
specimen, one-half nat. size. 


The small skull is elongated, ight in build, and rather 
narrow. The orbit is large and the zygomatic arch light. 
The premolar teeth are crowded, there being neither an ante- 
rior or posterior cingulum, though one is developed along the 
inner face around the protocone, running out on the hypocone. 
Crista and crochet are wanting on these teeth of a rather old 
individual, except that on the fourth premolar there is a faint 
trace of a crista, and on the third premolar a small antecrochet 
is developed. On the molars the cingulum is reduced as in 
the premolars; and both crochet and crista are wanting. The 
protoconule, however, is swollen, making a considerable fold 
as in European Diceratheres. A. stigerz is closely related to 
A. egrerius, but is smaller and has the cingulum on the pre- 
molars and the crochet on the molars less developed. 


Measurements. 
Moribtenethvot. the skull 202-222 5283020225552. about 345™™ 
Me tethcbet ween the orbits:22. 02. 02222. ee ee el Reger 
Length of the premolar-molar series -___: --..---------- = ese 
Keneth of second molar tooth ---.:.---:---.-- ae Seeks 2 ae 
Piatt secondemolar tooth. 2. oe sa ee 2 age 


Aceratherinm egrerius Cook. 
science, N.8., vol. xxvii, p. 206. 


Type a skull and lower jaws in the private collection of Mr. 
Harold Cook, from the Lower Harrison beds, at Agate, Sioux 
Co., Nebraska. 

This larger species has an elongate skull, of moderately hight 
build, the facial portion being unusually elongated ; so that the 


voceneé. 


dee of the Lower M 


te 


AnNOCEPrO 


Rh 


2t7S— 


4 
7 


FB. L900 


62 


YvVoM BqSTIO 
Suo1js yoyoorn 


ava, elour & QP X Cp UWOSLLIVAY “TY | ~~~ wuosuajzad -q 
—UIN[NSULD [vULeyUT 
VYSLIO ON @4SIIO ON 
ayelopoul JoyoorID qoyoolod ON lee ; 
ojaidutoo xjaveu ajatduroo ChX OP |wuQT Rg] gcp |UostIeH TT) asuatmuqow “q 
UIN[NSUL [VULoeqUuy UN[NSULD [VUIEZUT 
eYSILO ¢ 
S}JIT90.10 aE Pay an 
Sone 6 OF x gg Avq uyor wnoyiond “Gv 
UIN[NSULD [VULOJUT 
Ud]TOMS Bae ON 
atlodByIUL PUL et yi Aeq ugopr |~- wnidsadsay 
ee ULN[NSULO [VULOJUT 
asojo ATOA ABOM VISTI e4SI19 ON 
eauoo0déy puv queldrour yeyoorp yusidtour yayoorp 98 X 92 Avq uyor |~~“suapawun -G 
anttos0j01g Q0B1} GLOW B a0V1} V1OUL B © 
; WN[NSUlD TVULeyUT UIN[NSULO [RULOZUT 
B4SIIO ON B4S110 ON 
qualdrour yaqoo1n qyoyoold ON : se ‘ (eae ; 
eyo[dutooutr eqyotduoo wu 8G x OS wu()SG wu), GG Av uyot WNZDUAD d 
WMN[USULO [RULEZUT UIN][NSULD [VULe}UT 
G  rovorq (MAS #9| TAS Jo |TMAS Jo] og . 
SHIVULO S19JOVIVYO ARTOTW SLoJOVIVYO TRjOULeIg | jo Lee Lqustoq|,qipeerg | qa8u07] aoV aut NI 


» qysue'T 


WOIGAHHLVYAAXOId HO SH1INOEdS AHL AO LYUVHO 


63 


20GeENe. 


ver M 


d 


e/ 


j de of the Lo 


s—Rhinoceroti 


d 


F’. B. Loom 


Ud|TOMS TORUL 
eT UUO0D04OIg 


O0pia 
[CypLoes YIM 
ysty TMS 


811.000 
AT[Vusn ospia 
[eiW18es Oey M 

eR M38 


SYAVULIY, 


BqISLIO ON 


peylun youoory 
i 030;duL00 


WN[USULO [BULOJUT 


BYSILD ON 
BUTS JOTLIOID 
ejo[du100uL 


UIN[USULD [VULEJUT 


SUTUBM VISTO 


quoTdrouL yayoord 


9VBIT O10UL B 


UM[NSUL) [BVULozUT 


ydoyojo.rd 


oY} SV SUOT SV BISLID 
SHOULLOUO JOTOOAD 
QORT} V UIN][NSUL [BULOJUT 


YVIM VISTO, 


adie, ALVA JOYOOID 


OULYOV] 


UN[NSULD [BULEyUT 


OFRLOPOUL VISLID 
ASIV] JOYLDOLLA 
SUL OV] 


UIN[NSULD [VULOJUT 


SLOPOVARYD BLOW, 


SULIYURM BISLIO 
eTqnop yoyoo1p 
ayo[duioo 

UMN[NSULD [BULEZUT 


SUIQUVM BISTID 
querdrour yoyoorg 

—- 9NVTY OLOUT B 
WN[NSULD [RULoPUT 


BISLIO 

0} peyiun joyootn 
SULYOVy] 

UIN[MSULD [VULOVUT 


qOYooL) WO SVOPLE LOUTIAL 

BISLLO OF poyLUN YoYIoID 
oj0|duLoouL 

WH[NSULO [RULOJUT 


SLOYIVIVYO AV[OULOTG 


égG¢ x OP 


6&6 * && 


96 * 6& 


"vISLto oYY Jo doy oy} 0} UINUSRUT WOUTRLOJ OY} LOPUN WOT, pornsKoUt St yYLSLeq] | 


“S}IGIO OY} UWOIMJog PoINsveul St YJpvarl_ y 


EX 18 


mug ~ OF 


@ relout 
jo YQpreaq 
vy Yyouo'T 


vPL 


wus] 


[[nys Jo 


wwu6sL 


T[Myxs Jo 


| 43107] |,.q9 pworg 


CWONTINOO—WOTHARLVUNOId, fO SaToOudS WH oO LaIviy~) 


Y10.7 
dno'y 


eUusd0LI TT 


elicxerel a@) 


wodd 9, 


UOSTLIV ET “TT 


mugPpe  |WOSIIByy 7 
UWOSLLAUV ET TT 

[[nys jo 43 

qyduory Bey 


~~ asuauobawo "GJ 
““-"aaynanop ‘q 
>= WAPNULUE CT 
z SUDAMAQD “CT 
aeee ee wood “CG 
oor e= ehyos “¢ 
OUR NT 


\ 


64 F. B. Loomis—Rhinocerotide of the Lower Miocene. 


teeth are not so crowded as in the preceding species. On the 
premolars the cingulum extends around the front, inner, and 
rear faces. These premolars are very simple, showing no trace 
of a crista or crochet. The cingulum on the molars is inter- 
rupted on the inner face opposite both the protocone and 


Lili 


Fie. 15. Aceratherium egrerius C.; the premolar and molar series, 
one-half nat. size. 


hvpocone. A crochet is moderately developed, especially on 
the second and third molars. 

This and the preceding species show much resemblance to 
A. occidentale of the Oligocene. 


Measurements. 
Total length of the premolar-molar series____-_..-.._..-- 204™™ 
Length of second molari0? 2022 2 
Width of second molara. 222.00 520122 


Amherst College, Amherst, Mass. 


T. D, A. Cockerell—Descriptions of Tertiary Plants. 65 


Art. V.—Descriptions of Tertiary Plants; by T. D. A. 


CocKERELL. 


1. A Frog’s-bit from Florissant, Colorado, 


Limnobium obliteratum sp. nov. Figure la. 


Blade of leaf nearly circular, with a reniform base; 
obseurely about 10-nerved, these nerves simple, and exactly as 
in the living Z. spongia. Length from insertion of petiole to 
apex about 31™™, from apex of basal lobes to apex 35; breadth 
36. Margin perfectly entire, somewhat thickened. The apex 
is broadly rounded, with no tendency to pointing, such as is 
seen in the living if spongia. 

This is the first fossil species of this group from America ; 
but a similar plant occurs in the Miocene of Europe, and has 
been named by Heer Hydrocharis orbiculata ; “ distinguished 
by its circular leaves, which no doubt floated on the surface of 
the water like the leaves of water-liles.” 

/Zab.—F lorissant, in the Miocene shales, Station 14 (W. P. 
Cockerell, 1907). Peabody Museum, Yale, Cat. No. 1001. 


2. Two Maples from Florissant. 
Acer perditum sp. nov. Figure 106. 


Leaf with the blade deeply trilobed, the sinuses extending 
about half way to the base; the lobes broad, poimted, the mid- 
dle one broadest about 9™™" from its base, thence slightly con- 
tracted basally ; prominent nervures three, but also a smaller 
one on each side; margin obscurely and rather remotely den- 
tate. As preserved, the blade is yellowish, while the petiole 
and principal nerves are dark brown. Length of blade, about 

44mm, breadth abont 34; breadth of middle lobe in middle, 
1Q"™, Atases Oe length of middle lobe about 244"" ; of 
lateral lobes 20 or less. There is some resemblance to such 
fossil species as Aralia notata Ward, but the venation is very 
different, and agrees with that of Acer. Acer narbonnense 
Saporta, from the Oligocene, is a somewhat similar leaf, differ- 
ing however in its margin, and in the much less broadened 
base. The Chinese A. wilsoni Rehder is similar in general 
form, but its lobes are far more attenuate, its margins are almost 
completely entire, and the extra basal (external) veins are 
absent. There is also resemblance to A. sacchurwm rugelii 
(Wesm.) Rehd., which, according to Sargent, is a leaf-form 
sometimes appearing on the upper branches of trees which 
have on their lower branches the leaves of typical A. saccha- 
rum. In the southern states, however, the rugeliz form is 


Am. Jour. Sct.—Fourts Serius. Vou. XXVI, No. 151.—Juty, 1908. 
9) 


66 ZT. D. A. Cockerell—Descriptions of Tertiary Plants. 


normal, and frequently the only one present ; so it may per- 
haps be an open question whether the appearance of rugelic 
leaves on true séccharum is due to reversion or to hybridiza- 
tion. In the position of the lobes, the fossil resembles A. 
pennsylvanicum L. 

Hab.—F \orissant, in the Miocene shales. Station 14 (8. A. 
Rohwer, 1907). Peabody Museum, Yale, Cat. No. 1002. 


Acer florigerum, sp. nov. Figure le. 


Flower ; pistillate, apetalous, tetramerous. Styles two, sepa- 
rate to the base , long, exserted, straight or very lightly curved, 


ie 1. (a) Limnobium obliteratum ; (b) Acer perditum ; (c) Acer florigerum, 


Sele 


d} Phaca wilmatte. 


about 4°" long. No sign of any stamens. Sepals four, lan- 
ceolate, pointed, only about the basal two-fifths united. 

In the form of the styles, this resembles A. nigrum Mx., 
but the calyx segments are nearly as in A. drummondii in 
form. Only four calyx segments or sepals are preserved, and 
there were apparently no more. The dicecious tetramerous 
flowers indicate affinity with such species as A. tetramerum 
Pax, A. betulifolium Maxim., and A. barbinerve Maxim. 

FTab.—F lorissant ; Miocene shales (W. P. Cockerell, 1907). 
It was found at Station 14. I think this flower may safely be 


T. D. A. Cockerell--Descriptions of Tertiary Plants. 67 


assioned to Acer. As it presents some interesting characters, 
and cannot be assigned with any degree of assurance to any 
particular species known by leaves or fruits, I give it a sepa- 
rate name. Peabody Museum, Yale, Cat. No. 1003. 


38. A Veitch Pod. 


Phaca wilmatte sp. nov. Figure 1d. 


Pod strongly inflated, broad-ovate in outline, 13"" long and 
10 broad, apparently thick, as preserved dark red-brown, 
tipped with a thick strongly curved style about 33" long, and 
with a short thick stipe about 2™™ long, its union with the base 
of the pod perfectly abrupt. Calyx very small. In the form ~ 
of the pod, this is more like P. longifolia (Pursh) Nutt., but 
the pod being stalked, it is so far related to P. americana 
(Hook) Rydberg. | 

Hab.— Florissant, Miocene shales, Station 14 (Wilmatte P. 
Cockerell). Jam indebted to Miss Alice Eastwood for calling 
my attention to the affinities of this fossil. 

Peabody Museum, Yale, Cat. No. 1004. 


4. Miocene species of Hydrangea. 


In 1885 a supposed species of J/arsilea, found in the Upper 
Miocene beds of the John Day Basin, Oregon, was published 
by Ward. Lesquereux, in 1888, observing that the plant was 
certainly not a Jarsilea, but represented a calyx of some 
sort, referred it to Porana. In 1902, however (Bull. 204, U. 
S. Geol. Surv., p. 60), Knowlton, following a suggestion from 
Pollard, referred it to Hydrangea; and this appears to be 
certainly correct. 

Hydrangea as been reported to occur, with several species, 
in the European Tertiaries; but some of the species, at least, 
are doubtfully of this genus. 

In addition to H. bendiret (Ward) Knowlton from Oregon, 
two species have been found in the Miocene shales of Floris- 
sant. One of these, H/. subincerta, I have published in Bull. 
Amer. Mus. Nat. Hist., 1908, p. 92; the other, more recently 
found, is described herewith. 


Hydrangea florissantia sp. nov. 


Sterile flower large, the larger diameter about 21™”; sepals 
nearly round, the larger about 10™™ long, the smaller about 9 
(one of the smaller missing in the type); color as preserved 
light brown, the centre of the flower dark; venation distinct, 
except peripherally, nearly as in H. bendirez. 


68 7. D. A. Cockerell—Descriptions of Tertiary Plants. 


Evidently close to H. bendirez, but much smaller, more 
equilateral and with the shorter sepals less truncate. Very 
different from //. subincerta by the larger size and shape of 
the sepals. 


Fic. 2. Hydrangea florissantia, 


Florissant, Miocene, Station 14 (7. D. A. Cockerell, 1907). 
Type in Yale University Museum. On the same piece of 
shale touching the [1ydrangea (as shown in the figure) is what 
I take to be part of the male inflorescence of a Castanea— 
presumably that of C. dolichophylla Ckll., which is represented 
by leaves at Station 14. 


T. D. A. Cockerell—Descriptions of Tertiary Insects. 69 


Art. VI.— Descriptions of Tertiary Insects; by T. D. A. 


CocKERELL. 
Part IV. [Continued from p. 312. | 
(9) Dragonflies from Florissant, Colorado. 
Melanagrion nigerrimum sp. nov. 


Wines hyaline basally, to about three cells beyond the 
quadrangle ; beyond that black to apex (owing to the partial 
destruction of the membrane, the black is patchy and. irreg- 
ular; the apical field was perhaps dark brown rather than pure 
black); first row of costal cells broad, as in Lithagrion ; at 
the tenth cell before stigma the costal cell is half size of sub- 
costal, the latter being twice as deep; apex of quadrangle to 
tip of wing about 245"™ (262 in WZ. umbratum), but the ten 
costal celis before stigma measure together about 7$"™ (six in 
M.umbratum). Stiema large, about Bum long, homie five 
cells below ; costa obtusely bent at stigma, the margin bey ond 
rapidly descending to apex; eight poststigmatal sectors ; vein 
Cu,, 2 little before medioanal link ; base of wing agr eeing in 
general with J/. umbratum. 

Florissant: one specimen, with reverse ; Station 14 (W. P 
Cockerell, 1907). Holotype in Peabody Museum, Yale. 


Lithagrion hyalinum Seudder. Figure 1. 


A specimen was obtained by Mr. 8. N. Rohwer at Station 
17, on a slab with Typha lesquereuar Ckll.,* showing some 
characters heretofore obscure. There are certainly only two 
antenodal sectors. The stigma is swollen, and bounds 3% cells 
below. The total length of the wing is pgm . ; from nodus to 
stigma 143"; nodus to base PENE 2 louie ila of wing in middle 
7", These dimensions are uniformly less than in Scudder’s 
type, but that was probably an upper wing, while ours is appar- 
ently a lower; there may also be a difference of sex. (In 
Enallagma civile, male, I find anterior wing 193"™, posterior 

183). There are 17 sectors on costa between odie and stigma 
(16 in type ZL. hyalinwm), and 14 in the same distance in the 
subcostal series ; the costal cells beyond the stigma are doubled, 
which is not at all the case in Melanagrion nigerrimum (in 
M. umbratum there is a slight tendency to doubling). There 
are three simple cells,between M, and M, before the doubling 
begins. 

These new materials make the genus Melanagrion appear 
less distinct than when it was proposed, IZ. nigerrimum being 
in some respects intermediate between Melanagrion and Lith- 


* On the other side of the slab is Planorbis florissantensis Ckll. (Peabody 
Museum, Yale). 


70 7. D. A. Cockerell— Descriptions of Tertiary Insects. 


agrion. Characteristic of both is the position of vein M,, 

originating a long way before the level of the nodus, though 
not half-way to the arculus;—a condition found to- day in 
Megaloprepus, one of the Anormostigmatini. The question 
was raised, whether Lethagrion and Melanagrion could rep- 
resent the stem which gave rise to the Anormostigmatini; but 
altogether against this is the position of the long sector between 
veins M, and M,. Mr. E. B. Williamson writes that he regards 
the latter character as of considerable significance, and for this 
and other reasons’ would support Scudder’s reference of the 
insects to the Podagrion series. He adds, with reference to 


Fie. 1. Lithagrion hyalinum. 


M. umbratum: “it is not specialized by reduction, and the 
nodus is retracted as in Paraphlebia (but not so much as in 
Anormostigmatini), with which compare the more specialized 
Argiolestes and Wesolestes, for example.” 

The following table separates the three Florissant species : 


Wings hyaline; stigma bounding 33-32 cells below. 
L ithagrion hyalinum Seudd. 
Wings strongly infuseated ; stigma bounding 5 cells 
below. 
1. Apex of wings hyaline ; costal cells narrow. 
Melan agrion umbratum (Seudd. }. 
Apex of wings dark; costal cells broad. 
Melanagrion nigerrumum Cxkll. 


Tinallagma florissantella sp. nov. Figure 2. 


Wing hyaline, about 23™™ long (base gone) ; nodus to stigma 
124°"; nervures and stigma ‘dark sepia brown; subnodus 
oblique; subquadrangle not ero ossed ; 14 costal sectors between 
nodus and stigma ; stigma bounding one cell below ; costal 
cells beyond stigma large; only one “double cell in the series 
between M, and “the sector M,,, this immediately below stigma, 
separated therefrom by a single cell; three cells between 
quadrangle and level of nodus, the third very long, and 
represented by two cells in the series immediately below ; 


T. D. A. Cockerell —Descriptions of Tertiary Insects. 71 


upper side of quadrangle not or barely longer than inner side ; 
six cells on lower margin before Cu, begins to zigzag, and ten 
cells in the zigzag por tion, making 16 cells in all from ‘subquad- 
rangle and end of Cu, ; three cells between M, and M, before 
the doubling begins ; costa before nodus scarcely at all arched. 
Florissant : one specimen ; Station 14 (7. D. A. Cockerell). 
A poorly preserved leaf of Ficus arenaceetormis Ckll. is on 


the same slab. The figured specimen is in Peabody Museum, 


Fie. 2. Enaliagma florissantella. 


Yale. Some of the characters used to separate fossil Agrio- 
nines are so variable in recent species as to be of small value. 
This was pointed out to me by Dr. Calvert, and is very clearly 
indicated by a series of Enxallagma very kindly given to me 


by Mr. E. B. Williamson. Thus: 


(1) Cells between M, and M, before doubling begins. A 
specimen of £. antennatum (fischeri) has ‘three in ante- 
rior wing, four in posterior. 

(2) Cells between quadrangle and level of nodus (supposed to 
separate the fossil Agrion exsularis Seudd. from A. masce- 
scens Seudd., the first having three, the second four). 
Three is the usual number in Enallagma, but E. travi- 
atum may have four, and in a male £. carunculatum one 
wing has four, the other three wings three each. 

(3) Length of upper s side of quadrangle. It is much shorter 
in anterior than posterior wings of Enallagma civile, 
E.. antennatum, E. exsulans, and E. traviatum. 


On the other hand, many undoubtedly distinct recent species 
are so similar in the wings that it is exceedingly difficult, to 
say the least, to separate them by these organs alone. In deal- 
ing with the fossils, therefore, one may well hesitate to assert 
that species are synonymous, although some of their assigned 
characters are likely to be of less than specific significance. 

The Florissant species of this group may be separated as 
follows: 

Subquadrangle with a cross-nervure in the middle; sub- 
nodus almost vertical ; first postnodal cell considerably longer 
than second ; eleven postnodal sectors. 

“ Trichocnemis” aliena Scudder. 


72 T. D. A. Cockerell—Descriptions of Tertiary Insects. 


Subquadrangle without a cross-nervure; subnodus 
obliquepiar ris ruil: 

1. Nervures and stigma pale ferruginous ; ten postnodal sec- 
tors; stigma very oblique, with the inner side as long as 
the outer. Llesperagrion prevolans Ck. 

Nervures dark brown or black ; stigma ordinary. . 2. 
2. Costa before nodus conspicuously arched ; 11 postnodal 
cross-veins ; curved basal section of M, very short. 
Agrion exsularis Seudd. 
Costa before nodus hardly arched ; curved basal section of 
M, longer. 3. 

3. Postnodal cross-veins 10 to ele upper side of ‘quadrangle 

longer than inner. Agrion mascescens Seudd. 
Postnodals 14 ; upper side of quadrangle a little shorter than 
inner. knallagma florissantella Cll. (probably 


upper wing). 


The postnodals in living Hnallagma are from 9 to 11, at 
least in the species examined. I find the upper side of quad- 
rangle much longer than inner in /. fischeri and FL, exsulans ; 
but in an upper wing of £. carunculatum the inner is longer 
than the upper. The difference between the quadrangles of 
A. mascescens and £. florissantella cannot be due to their rep- 
resenting different wings, for the upper wing of mascescens 1s 
known, and has the upper side of the quadrangle very long. 

The position of the base of the quadrangle seems to be 


of some significance : 


(1) Base of quadrangle conspicuously before level of midmost 
point between antenodal cross-veins. A. mascescens. 
(2) Base of quadrangle at or near level of midmost point. 
EL, florissuntella, A. exsularis, EL. fischerc ; 
E. signatum, EF. hagent. 
(3) Base of quadrangle far beyond level of midmost point, not 
tar from level of first cross-vein. 
L. carunculatum, EE. civile. 


Trichocnemis aliena Scudder. Figure 3. 


A wing was obtained at Station 13 B(W. P. Cockerelt ). 
The most striking character, the crossed subquadrangle, is 
unfortunately not visible in our specimen, but there is no reason 
to doubt that it exists, as represented in Scudder’s figure. Mr. 
Williamson writes: 

“ Paraphlebia is the only Agrionine genus known to me with 
crossed subquadrangle. It is a character that disappears with 
reduction in the Calopterygine ; e. g., Dephlebia has it rarely 
crossed. Cyanocharis has quadrangle but not subquadrangle 
crossed ; Dewndgiia has both quadrangle and subquadrangle 


T. D. A. Cockerell— Descriptions of Tertiary Insects. 73 


crossed; JMicromerus has quadrangle usually crossed and sub- 
quadrangle with one or two cross-veins. Paraphlebia, men- 
tioned above, of course is entirely different from Z7richocnemis 
in all other characters.” 

With regard to the vertical subnodus, Mr. Williamson writes : 

« Xunthagri ion erythroneurum has it vertical; Lrythromma 
NaUS (especially the hind wing) nearly or practically so; 1t 1s 
nearly vertical in the American Oxyagrion, Argia, yponeur a 
and Ischnura (at least some of the species). This character, 
I believe, appears independently many times, and is no crite- 
rion in itself” of generic relationships. 


Fic. 38. Trichonemis aliena. 


Except for the crossed subquadrangle, Mr. Williamson says 
that he sees no objection to referring 7. aliena to Hespera- 
grion. “The form of wing is similar; the quadrangle, sub- 
quadrangle and the relations of their parts to the antenodals 
are similar; the origin of M, is similar; and the length and 
direction of the subnodus are ‘not far out of the way. I believe e, 
in this view, that 7. alzena |Scudder’s type] is a hind wing.” 
Mr. Williamson further adds: 

“T have compared Scudder’s figure with wings of Calicne- 
mis, Hemicnemis (Leptocnemis), Platycnemis and Tatocne- 
mis,—some of the genera usually associated with Zrzchoenemis. 
If Scudder’s figure of wing is correct in outline, 7. addenda is 
not similar to any of the above genera. In arrangement of 
veins at distal end of quadrangle, Z. a/zena is most similar to 
Hemicnemis (which genus, of the whole group, has the quad- 
rangle most dissimilar) and Calicnemis. In arrangement of 
veins at base of quadrangle it most resembles Platycnenmis. 
Moreover, in above genera, only in Platycnemis is the sub- 
nodus nearly or quite vertical. In Zatocnemzs (which is very 
dissimilar in many characters), the subnodus is very short.” 

Our specimen, like Scudder’s, has eleven postnodal cross- 
nervures. The first cross-nervure beyond the stigma is forked 
below. There are three cells between M, and M, before the 
doubling begins (four in Seudder’s type). There is a very dis- 


t+ 7. D. A. Cockerell—Descriptions of Tertiary Insects. 


tinct brace-vein. The figured specimen is in Peabody Museum, 
Yale. 


Hoploneschna separata (Scudder). 


Two specimens, representing the hind wing, were obtained 
at Station 14, one by my wife, the other by myself. Seudder’s 
type, an anterior wing, was referred to Laszeschna; but 
Needham expressed the opinion that it belonged to Hoplonee- 
schna (Pr. U.S. Nat. Mus., xxvi, p. 761). The new specimens: 
are far from perfect, but they show that the hind wing has 
the following characters: 


(1) Triangle with a double cell at base, and then four simple 
cells, varying to a double and three simple cells. 

(2) Anal triangle of three cells. : 

(3) M,, after running parallel with M,, separated by a single 
row of cells, is suddenly bent downwards, and is separ- 
ated by two and three rows of cells; a character of 
floploneschna. 


In my table in Bull. Amer. Mus. Nat. Hist., xxiii, pp. 133, 
134, the insect runs to Basiwschna; but the anal triangle 
agrees with Hoploneschna, and not so well with Basiwschna. 
On the other hand, as to the stigma //. separata is like 
Basiceschna, not like Hoploneschna. The region about the 
triangle agrees almost exactly with Gynacantha. 

The number of cells in the triangle is variable in _A’schnids. 
Mr. Williamson, to illustrate this point, has very kindly sent 
statistics of three very closely allied forms of /schna, based 
on males. In order to make them clear, [ have constructed 
cell formule, enumerating the cells in order, beginning from 
the base. Thus 2, 1, 1, means a double cell am then two sim- 
ple ones; 1,1, 1, three ‘cells, all simple. 


rout Wing. 
1, . . Indiana species (2 specimens). 
1, . . Multicolor (seven). 
, 1, 1, Multicolor (eleven), Indiana sp. (18), Jalapa sp. (7). 
1,1, Multicolor (two), Jalapa sp. (1). 


Hind Wing. 


ee al eicolor(one): 
ily . Multicolor (17), Jalapa sp. (4), Indiana sp. (2). 


2, 
3 1, ie 1, Multicolor ee Jalapa sp. (4), Indiana sp. (18). 


The number of cells in the anal triangle Mr. Williamson 
states is also not of generic importance. He adds: ‘“ The kink 
in My asa character generally associated with the curving 


T. D. A. Cockerell— Descriptions of Tertiary Insects. 75 


backwards of radial and median supplements (see Coryphe- 
schna ingens for maximum of both characters, and Vasieschna, 
e.g., for minimum).” Mr. Williamson concludes that separata 
cannot go in Lasieschna; and unless a new genus is proposed 
for it, Hoploneschna seems to be the only genus to receive it. 


Phenacolestes paratlelus Ckll. 


This species was described from the apical part of the wing. 
The base of a wing, probably belonging to P. parallelus, is 
from Station 14 (Geo. WV. Rohwer). It differs from P. 
morandus Okll., in having six antenodal cross-nervures, the 
nervure from subquadranele to lower margin. arising from 
almost the apex of the former, and cross-nervure in fork of 
M,,, and M, before level of nodus. The part visible (as far 
as separ ation of M, from M,) is hyaline. 


(10) A Longicorn Beetle from Florissant. 


Saperda (7?) submersa sp. nov. Figure 4. 


Length about 227"; width of head about 44; width of 
thorax about 4; of insect in humeral region of ae tra about 
745 length of head and thorax about gim antennee rather 
thick, probably about 16™™ long, but the extreme tip missing. 
Head dark above, but face and mouth pallid; thorax 4, 
‘pallid, darker posteriorly ; elytra black at base (espe- 
cially on humeri), after which comes a broad ae 
44™ long) light area, forming a broad band across both 
elytra, the remaining portion of the elytra black. 
Abdomen extending a little beyond tips of elytra. 

In general build and appearance, this is like Superda. I can- 
not demonstrate any lateral spimes on thorax and believe there 
were none, but this part is not very clearly visible. The 
transverse light area on the elytra recalls Oncideres cingulatus, 
althongh more basal than in that insect; the antenne are like 
those of Saperda, not like Oncideres. The rather broad head 
suggests Mecas rather than Saperda. Type from the Miocene 
shales of Fiorissant, Colorado, collector unknown. Mr. G. L. 
Cannon, who kindly placed it in my hands for description, 
informs me that it has been in the collection at the State 
Capitol for at least 25 years. 

Four fossil species of Saperda have been described from 
Europe. Three are from the Miocene, but one of these 
(S. valdensis Heer) is not identifiable. 


University of Colorado, Boulder. 


76 = = Wickham—New Fossil Elateride from Florissant. 


Arr. VII.—WNew Fossil Elateride from Florissant: by 
H. F. Wickam. 


Corymbites Latr. 


C. granulicollis (figure 1).—Body rather short and stout. 
Head about equal in length and breadth, front apparently 
transversely rugose; antenne broken, but the remaining por- 
tion shows them to have been rather slender and only very 
little serrate, probably not attaining the hind angles of the 


1 2 


Fie. 1. Corymbites yranulicoliis, n. sp. x 2. 
Fic. 2. Corymbites primitivus, n. sp. x 2. 


thorax. Prothorax emarginate and narrower at apex, grow- 
ing broader with equal lateral curve to about the middle, then 
arcuately narrowing to a point just anterior to the posterior 
angles, which are rather markedly divergent and distinctly uni- | 
carinate; the disk with small closely placed granules, each 
with a minute central puncture. These granules become 
much finer and more crowded near the sides, and a median 
basal area (which may have been canaliculate) is nearly devoid 
of them. Elytra finely alutaceous, finely and sharply striate 
but not punctured. Anterior leg (the only one visible) short, 
second, third and fourth tarsal joints about equal. 


Wickham—New Fossil Elateride from Florissant. 77 


Length (of entire insect) ‘96 1n., of elytron about °60 in., of 
prothorax about °23 in.; width of prothorax about ‘26 in. 

I place this insect in Cor ymbites trom the general form ; 
the shape of the prothorax strongly recalls that of C. carbo 
Lec., and C. wreipennis Kby. 

One specimen (Cat. No. 1, Peabody Museum, Yale), Station 
14;8. A: Rohwer. 

0, primitivus (figure 2).—Form rather stout, head finely and 
rather closely punctured. Prothorax emar oinate at apex, 
front angles obtuse, sides broadly arcuate, more sharply in 
front of the middle, the oreatest” width being at about one- 
third of the length, hind angles distinctly carinate but rather 
short and not strongly divergent; disk finely densely subru- 
gosely punctate, less closely along the middle. Elytra with 
fine sharp impunctate  strie, interstitial spaces finely irregu- 
larly punctured. Legs and antenne invisible. 

Length, entire, 87 in., of elytron 50 in., of prothorax along 
median line 20 in.; width of thorax °23 in., of elytron about 
Sin. 

One specimen (Cat. No. 2, Peabody Museum, Yale), Station 
13; Geo. N. Rohwer. 

Here, again, I have placed the species by its general appear- 
ance, the truly generic characters all being obscured. 


Melanactes Le Conte. 


MM. cockerella (figure 3).—Body moderately elongate. Head 
narrower than thoracic apex, antennee attaining base of thorax, 
basal joints obscured, the seven distal ones subequal in width 
and but slightly serrate, each very little longer than wide, 
front fairly closely but not coarsely punctured. Prothorax 
slightly broader than long, narrowest at apex, arcuately wider 
to a point a little behind the middle, thence slightly narrowed 
to near the hind angles which are somewhat (but not markedly) 
divergent, disk finely and closely punctate towards the sides 
but much more sparsely and a trifle more coarsely about the 
middie; the marginal bead of the pronotum is very distinet, but 
it is uncertain whether the hind angles are carinate or not. 
Elytra apparently distinctly alutaceous, striate, the striz fine 
and marked at their bottoms with rows of moderately deep 
slightly elongate punctures which are separated by intervals 
arranging approximately the lengths of the punctures, Legs 
invisible. 

Length, entire, ‘94 in., width of prothorax, slightly behind 
the middle, -26 in., of elytron °37 in. 

One specimen (obverse and reverse, Cat. No. 38, Peabody 
Museum, Yale), Station 14; Mrs. W. P. Cockereli. 


78 Wickham—New Fossil Elateride from Florissant. 


Fie. 8, Melanactes cockerelli, n. sp. x 2. 


In lite, this insect must have been about the size of JW. 
densus Lec., or Ml. piceus De G., resembling the former very 
closely in thoracic and elytral sculpture. 

Named after a good friend and ardent entomologist, Pro- 
fessor Cockerell, from whose hands the foregoing species were 
received. 


Iowa City, lowa 


G. Edgar—FEstimation of Iron and Vanadium. 79 


Art. VIIl—The Estimation of Iron and Vanadium in 
the Presence of One Another ; by GrawHAM Ener. 


{Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxvi. ] 


Tue difficulties in the separation of vanadic acid from iron 
were early recognized. In 1877 Bettendorf* noted that am- 
monium hydroxide precipitates from a solution containing these 
substances a yellow vanadate of iron not entirely decomposed 
by an excess of the reagent. He therefore added an excess of 
ammonium phosphate and boiled the solution, whereby the iron 
was converted into ferric phosphate and precipitated as such 
on the addition of ammonium hydroxide, while the vanadium 
remained in solution. Carnott used repeated precipitation by 
ammonium hydroxide, ammonium acetate or ammonium sul- 
phide, this process serving to remove iron but not aluminium 
or chromium. According to Classen, t vanadic acid may be 
separated from iron in ores by fusion with sodium carbonate 
and sodium nitrate, and extraction of the melt with water, 
the vanadium going ‘into solution as sodium vanadate. Accord- 
ing to Arnold,§ in the analysis of steel, a fusion with sodium per- 
oxide and extraction with water serves to obtain the vanadic 
acid in solution, free from iron. Fritcherle,| in the analysis of 
carnotite, precipitated iron together with uranium and vana- 
dium with an excess of sodium carbonate, then added sodium 
hydroxide and boiled for some time, the vanadie acid alone 
going into solution. Blum, in separating vanadium from 
rather large amounts of iron, as in pig iron, states that the 
separation is only complete when, after precipitation of the 
iron as hydroxide or basic acetate, the precipitate is redissolved, 
tartaric acid added and the iron precipitated by means of an 
excess of ammonium sulphide, the solution being allowed to 
stand for several hours. Campagne** separates the greater 
part of the iron in ferrovanadium and vanadium steel by 
repeated extraction of the hydrochloric acid solution with ether, 
afterward determining the vanadium by repeated evaporation 
with concentrated hydrochloric acid, removal of this acid by 
means of sulphuric acid, and titration with potassium, perman- 
ganate. He states that if it be desired to determine the iron pres- 
ent, the original solution, without extracting with ether, may 

* Poggendorff’s Ann. der Phy., clx., 126-181. 
+ Chem. News, lvi, 16 
t Amer. Chem. Journal, vii, 349-353. 
S$ Electrochemist and Metallurgist, March-April 1902. 
| Chem. News, lzxxii, 258. 


*| Zeitschr. Anal. Chem., xxxix, 156-157. 
** Ber. der Dtsch. Chem. Gesel., xxxvi, 3164. 


80 G. EKdgar—Lstimation of Iron and Vanadium. 


be boiled repeatedly with hydrochlorie acid to reduce the vana- 
dic acid, the hydrochloric acid removed by means of sulphuric, 
and the vanadium titrated with permanganate. If then the 
solution be reduced with hydrogen sulphide, the excess of gas 
removed by boiling and the solution again titrated with per- 
manganate, the difference between the two titrations will give 
the iron present. Glasmann™* effects the separation by adding 
potassinm iodide to the sulphurie acid solution, removing the 
free iodine by means of sulphur dioxide, neutralizing with po- 
tassium hydroxide, and precipitating the iron by means of a mix- 
ture of potassium iodide and iodate. The liberated iodine is 
removed by sodium thiosulphate, the ferric hydroxide filtered 
off and the vanadium estimated in the filtrate. | 

Among other methods of separation may be mentioned that 
of Classen, + who precipitates the iron electrolytically from a 
solution of the double oxalates, and Myers, t who deposits the 
iron using a mercury cathode, the vanadium in both eases 
remaining in solution. 

In view of the dithculties attendant upon the separation of 
iron and vanadium, and in view of the increasing importance 
of such substances as ferrovanadium and vanadate of iron, 
composed almost entirely of these elements, it has been thought 
advisable to present a method by which vanadium and iron 
may be estimated in the presence of each other. 

If a solution containing vanadic acid and iron be reduced by 
means of sulphur dioxide the reoxidation by potassium perman- 
ganate proceeds according to the equation 


5V,0,+10FeO +4K MnO,=5V,0,+5Fe,O,+ 2K,0+4Mn0 (1) 


If this solntion, after titration, be passed through a column 
of amalgamated zinc in the Jones reductor, the receiving flask 
being charged with a solution of ferric sulphate, the reduction 
is carried, in the case of vanadie acid, to the condition of V,O,$ 
and the reoxidation by permanganate proceeds according to 
the equation 


5V,0,+10FeO +8K MnO,=5V,0,+5Fe,0,+4K,0+8Mn0 (2) 


The difference in the number of cubic centimeters of per- 
manganate used in the first and second titrations is evidently 
used in oxidizing the vanadium from the condition of V,O, to 
V,O,, and multiplied by the factor 00456 (for exactly N/10 solu- 
tions) gives the amount of vanadic acid present. This being 
known, the iron present may be calculated from the amount of 
permanganate used in either titration. 

* J. russ. Phys. Chem. Ges., xxxvi, 77. 
+ Ber. Dtsch. Chem. Ges., xiv, 2771-85. 


tJ. Amer. Chem.*Soc., xxvi, 1124. 
S$ Gooch and Edgar, this Journal, xxv, 238. 


Ferric 
Alem ak Il 
in KMnO, KMn0O, 

Receiver N/10x 9545 V205 V.0; Erroron  Fe,O; Fe.0; Error 
a = taken found V2.Os5 taken found Fe.03 
em3, cm?. erm. erm. grm. grm. grm. grm. 
35 31°90 58:02 0:1136 0O711387 +0:0001 0°1487 071436 —0-0001 
ag so) 58:04. O1186. O:1138 .+0°0002 0 1437. 0:1435. -—0:0002 
35 aioe 9 5S'00.- O°HI386 O1138. + -0002. -0°1437 .0°14383 —0-0004 
30 31-90. 58:00 _0O°1136 O-1136 ° +0:0000. 0°1437 0:°1437 +0:'0000 
20 75-30 > 38-35. 0:°0568. 0:0568— +0°0000 _0°1487. .0:1423 —0-0004 
20 95°29 38°30 0°0568 0°0566 —0:0002 0°1437 0°1483 —0:0004 
20 15°98 29:02 0°0568 0°0568 +0°0000 0:0719 O°0721 . +0:0002 
50 oso | OO, wOO4. 0-1 1.04% ».— 00009. (O°1437 071442 . + 0°0005 
50 38°45 77:60 0°1704 0°1704 +00000 0O°1437 0°1488 +0:°0001 
50 aes 77-58 9071704 -0-1703-. —0'0001  0°1437 071439 -+0:0002 
35 22°50 48°60 0°11386 0°1136 +0°0000 0°0719 0:0720 +0°0001 
35 22°50 48°60 011386 0°1136 +0°0000 0°0719 0°0720 +0°0001 
35 92°45 48°58 0711386 0°1187 +0°0001 0°0719 0°0716 —0:0003 
20 15°97 29°07 0°0568 0°0570 +0°0002 0°0719 O°0718 —0O:0001 


* Inaug. Diss., 


G. Edgar—Estimation of Iron and Vanadium. 81 


In the experiments in Table I three standard solutions were 
used, viz. :— | 

1. A solution of potassium vanadate, slightly acidified with 
sulphuric acid, and containing 11°36 grams of vanadic acid to 
the liter. This solution was standardized by the method of 
Holverscheit.*, 

2. A solution of ferric alum, slightly acid, with sulphuric 
acid and containing 14°37 grams On ferric oxide ‘ the liter. This 
solution was standardized by the very accurate method of 
Newton. t+ 

3. An approximately tenth normal solution of potassium per- 
manganate (3°16 grm. per lit.), standardized against a N/10 
solution of arsenious oxide. 

The details of manipulation were as follows :—Measured 
portions of the ferric sulphate solution were mixed with por- 
tions of the solution of vanadic acid, and a current of sulphur 
dioxide was passed through the slightly acid mixture until the 
color had changed from red into green and finally into a clear 
blue. A few centimeters of dilute sulphuric acid were then 
added, and the solution heated to boiling, the current of sul- 
phur dioxide being replaced by one of air-free carbon dioxide. 
When the last traces of sulphur dioxide had been removed, the 
flask was cooled in running water, the atmosphere of carbon 
dioxide being maintained, and when thoroughly cool, titrated 
with potassium permanganate until the color had changed from 
blue into yellowish green. The solution was then heated to 


Berlin, 1890. + This Journal, xxv, 343. 


Am. Jour. Sct.—FourtH SERigs, Vout. XXVI, No. 151.—Juty, 1908. 
6 


82 G. Ldgar—Estimation of Iron and Vanadium. 


70°-80° and the titration completed at that temperature. The 
solution, having now a volume of 100-150°™, was passed 
through a column of amalgamated zine ina long Jones reductor, 
being preceded by 150° of hot dilute (23 per cent ) sulphuric 
acid and followed by 100°™ of dilute acid and finally .200%™* of 
distilled water. The receiving flask, containing. an excess of 
ferric sulphate, was kept cool by means of running water, and 
its contents, after the addition of sirupy phosphorie acid to 
remove the color of the iron, were titrated with permanganate 
until the color had changed from bluish green to yellow, 
and the color of the permanganate began to be persistent and 
destroyed only by shaking. The flask was then heated to 70° 
80° and the titration completed in the hot solution. 

The results given in the table show that iron and vanadium 
may be readily estimated in the presence of each other by two 
oxidations with potassium permanganate, following reduction 
first with sulphur dioxide and last with amalgamated zine, 
_ under the conditions described above. 

In conclusion, the author desires to thank Prof. F. A. Gooch 
for advice given in the course of the work. 


Uj 


Browning and Palmer—Estimation of Cerium. 83 


Arr. LX.—On the Estimation of Cerium im the Presence 
of the other Rare Earths by the action of Potassium 
Ferricyanide ; by Eee E. Browniye and Howarp E. 
PALMER. 

[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxvii. ] 
Tue work to be described was undertaken to determine how 

completely the oxidation of cerium from the cerous to the 
ceric condition may be effected by potassium ferricyanide in 
alkaline solution, and how completely the measure of the oxi- 
dation can be registered in the amount of potassium ferrocy- 
anide formed, according to the following equation : 

2K FeO.N, + Ce,O, + 2KOH = 2K,FeC,N, + H,O + 2CeO,, 
For this work a solution of pure cerous sulphate was made 
and standardized by precipitating measured and weighed por- 
tions with a definite amount of a standard solution of sodium 
oxalate, filtering, igniting the cerium oxalate, and weighing 
the ceric oxide obtained. As a check on this method, the 
excess of the sodium oxalate over the amount used for the 
precipitate was determined in the filtrate by titration with 
potassium permanganate, and this amount was subtracted 
from the whole amount of sodium oxalate used. From this 
result the cerium present can be readily estimated, the amount 
of sodium oxalate used in the precipitation being known.* 

The ferricyanide solution used was made by dissolving 2 
grams of carefully selected crystals of potassium feieneetde 
in 100° of water. About 20™* of this solution were used 
in each determination. | 

The procedure was as follows: To measured and weighed 
portions of the cerous sulphate solution 20° of the ferricy- 
anide solution were added, and potassium hydroxide in solu-. 
tion to complete precipitation. 

The precipitated hydroxide was filtered off and the filtrate 
and washings, amounting in volume to from 200° to 250°", 
after being made distinctly acid with dilute sulphuric acid, 
were titrated with a standard solution of potassium perman- 
ganate until the presence of the permanganate color showed 
the oxidation of the ferrocyanide to the ferricyanide,t accord- 
ing to the equation : 

5K,FeC,N, + KMn0O, + 4H,SO, = aie BEC INE Habs Oia 

MnSO, - “4H, O. 

By this equation and the pr eceding one the amount of cerium 

present can be readily calculated. 

Each day before the ferricyanide was used a portion of 20° 
of the solution was acidified and titrated with the permanganate 
to color, and the amount necessary, generally from one to 
three drops, was subtracted from the amount of the perman- 


* Browning and Lynch, this Journal [4], viii, 457, 1899. 
+ Sutton’s Volumetric Analysis, [IX edition, page 209. 


84 Browning and Palmer—Estimation of Cerium. 


ganate used in the actual determination. It is of interest to. 
note that ferricyanide solutions kept in clear glass bottles for 
a week or more showed variations of only a drop or two in the 
amount of permanganate taken up. 

All the various operations in this process were carried on 
without warming the solution. The filtrations and washings 
were generally made under gentle pressure, and required on 
an average not more than fifteen to thirty minutes. In Table 
I the results obtained with cerium present alone are given. 


TABLE I. 
Ce taken, caleu- Ce found, calcu- 

lated as Ce,O; lated as Ce.O; Error 

erm, grm. grm. 
(1) 0°1834 0°1819 —0°0015 
(2) 0°1376 0°1380 +0:°0004 
(3) 0°1834 0°1829 —0°00085 
(4) 0°1834 0°1829 —0°0005 
(5) 0°18384 0°1834 +0°0000 
(6) 0'1376 0°1885 +0°0009 
(7) O36 01371 —0°0005 
(8) 0°1376 0°1374 —0°0002 
(9) 0°1376 0°1380 +0°0004 
(10) 0°1834 0°1824 —0:°0010 
(11) 0°1326 0°1335 +0:°0009 
(12) 0°1326 0°1328 +0°0002 


Solutions of the salts of the other rare earths, containing 
about 0-1 grm., were treated by the same method, and the 
failure to obtain evidence, by the permanganate, of the for- 
mation of potassium ferrocyanide, showed that there is no 
oxidation of these salts by the ferricyanide. 

In Table IL the results obtained by estimating cerium 
according to this method in the presence of the other rare 
earths are given. 


TABLE II. . 
Ce taken, caleu- Ce found, calcu- Other Rare Harths present, 
lated as Ce.03; lated as Ce.O; Error calculated as oxides 
grm. erm. erm. erm. 
(1) 0°1328 0713385  +0°0007 0 IThO, 
(2) 2 04327 0°1322 —0°0005 Orl 
(3) 0°0266 0-0275 + 0°0009 Orkneys 
(4) 0-0267 0°0272 +0°0005 Op ipse 
(5) 01824 0°1326 + 0°0002 0-1Y,O 
(6) 0°1326 0°1323 —0°00038 ORE eee 
(7) 0°0266 0°0264 —(0°0002 Ocal be A ais 
(8) 0:0264 0°0271 +0:°0005 Ogi wes 
(9) 0°1376 0°1370 —0°0006 0:15La,O, ae! O, 
(FO), 0-1 VOr 0°1091 — 0'0010 0°15 «“ 
(11) 01324 0°1332 +0:°0008 0°03ZrO, 


This method presents no difficulties in manipulation and 1s 
especially adapted to the rapid estimation of cerium in rare 
earth mixtures. 


Gooch and Weed—LEstimation of Chromium. 85 


Art. X.—The Estimation of Chromium as Silver Chro- 
mate; by F. A. Goocu and L. H. Wexsp. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxviii. | 


Ir has been shown by Autenrieth* that when chromic acid is 
added to a boiling solution of silver nitrate, or when a soluble 
chromate or dichromate is added to a solution of silver nitrate 
previously acidified with nitric acid, or when silver chromate 
is treated with nitric acid, silver dichromate is formed ; and that, 
on the other hand, it is silver chromate which is precipitated 
when silver nitrate in excess is added to a solution of a soluble 
dichromate, cold or hot, the reaction proceeding according to 

the equation 


4AeNO,+K,Cr,0,+H,O = 2Ae,CrO, + 2KNO, +2HNO,. 


The characteristics of both silver dichromate and _ silver 
chromate have recently been summarized and further studied 
by Margosches,t but so far as we know there is in the literature 
no account of procedure for the exact quantitative determination 
of either chromium or silver based upon the characteristics of 
either of these salts. The solubility of silver dichromate in 
water and in ordinary solutions is such as to preclude the use 
of this substance as the final product of a quantitative process 
depending upon precipitation. The solubility of silver chro- 
mate in a moderately large volume of water is not inconsider- 
able, and the solvent action of free acid, even acetic acid in 
‘quantity, is marked. We have found, however, that the pre- 
cipitation of silver chromate is practically complete in a solution 
only faintly acid with acetic acid and in presence of a large 
excess of silver nitrate. If such a precipitate is collected in 
the fitering crucible and washed with a dilute solution of silver 
nitrate, until no other impurities remain, silver chromate 
does not dissolve, and the excess of silver nitrate may be re- 
moved by the cautious use of water without appreciable effect 
upon the precipitate. The present paper has to do with the 
determination of chromium as silver chromate. 

In the experiments of which the details are given in the 
table, the general treatment just described was put to the 
practical test. Given amounts of potassium dichromate were 
weighed out and dissolved in hot water, as in experiments (11) 
and (12), or given amounts of a solution of potassium dichro- 
mate of known strength were run from a burette into a beaker 
and heated to boiling, as in experiments (1) to (10). To the 
hot solution of the dichromate was added, drop by drop, a 


* Ber. Dtsch. chem. Ges., xxxv, 2057. 
+ Zeitschr. anorg. Chem., xli, 68; 1, 231. 


86 Gooch and Weed—Estimation of Chromium. 


solution of silver nitrate in considerable excess, and the mix- 
ture was again brought to the boiling point. Ammonium 
hydroxide was added until the clear liquid became colorless 
and turned litmus paper blue; then acetic acid was added 
cautiously until the reaction of the solution was distinetly 
acidic to litmus. After standing for at least a half hour the 
precipitate was filtered off on asbestos in a perforated crucible, 
washed first with a dilute solution of silver nitrate and then 
with 20°" to 80° of distilled water applied in small portions, 
and dried with gentle heating to a constant weight. In exper- 
iments (1) to (10), the drying was done in an air bath heated 
to 135°; in experiments (11) and (12), the crucible and pre- 
cipitate were heated gently over the free flame. In experi- 
ments (7) and (8) the precipitation was made in presence of 
5 grms. of ammonium nitrate, and in (9) and (10) in presence 
of 5 grms. of sodium nitrate, to test the effect of each of 
these substances upon the process. In no case did the filtrate, 
with the washings, show by the lead acetate test the presence 
of a chromate. 


The Precipitation of Silver Chromate. 


AgNO; 
Used in Volume at AgeCrO, 

K.Cr20; precipi- precipi- — === ——s . 
taken tation tation Found Theory Error 
Crimes erm. cm’. 

(1) 0°0921 0°4248 100 0°2072 0°2076 —0°0004 
(2) 0°0921 0°4248 100 0°2073 0°2076 —0°0003> 
(3) 0°0921 0°4248 100 0°2075 0°2076 —0°0001 
(4) 0°0921 0°4248 100 0°2074 0°2076 —0°0002 
(5) 0°0921 0°4248 100 0 2075 0°2076 —0:°0001 
(6) 0°0921 0°4248 100 0°20738 0°2076 —0°0008 
(7) 0:0921 0°4248 100 0°2073 0°2076 —0:0003* 
(8) 0:0921 0°4248 100 0°2075 0°2076 —0:0001* 
(9) 0°0921 0°4248 100 0°2080 0°2076 +0:0004 ¢ 
(10) 0:0921 0°4248 100 0°2070 0°2076 —0-0006 + 
(11) 0°5801 3° 150 1°3087 1°3082 +0:°0005 
(12) 0°7352 3° 200 1°6573 16574 —0-0001f 


*The precipitation was made in presence of 0 grm. of NH,NOs. 
+ The precipitation was made in presence of 0 grm. of NaNOs. 
t An excess of 1°™° of 40% acetic acid was added before filtering. 


From the results of these experiments it is apparent that 
accurate determinations of chromium taken as the chromate or 
dichromate may be secured by precipitating silver chromate in 
presence of an excess of silver nitrate, making the solution 
ammoniacal and then faintly acid with acetic acid, transferring 
the precipitate to the filtering crucible, washing with a dilute 
solution of silver nitrate, and, after other soluble impurities 
have been removed, finishing the washing with small amounts 
‘of water applied in successive portions. 


C. Barus—Standardization of the Fog Chamber. 87 


Art XI.—Wote on the Standardization of the Fog Cham- - 
ber by the aid of Thomson's Electron ; by Cart Barus. 


1. Advantages.—Of all the methods which I have tried to 
evaluate the coronas in terms of the number of nuclei which 
they represent under given conditions of exhaustion, the above 
method is the most promising and expeditious. A single 
experiment need take but a few minutes. Incidentally the 
observer learns whether the negative and positive ions have 
both been captured ; for on using the tables of coronas which 
I developed heretofore, the value of ¢ may be computed, and 
the result must coincide with Thomson’s value. 

2. Method.—My first experiments were made with a metal 
plate in a fog chamber, both the coronas and the current being 
observed successively, without changing the adjustment. But 
this was abandoned for a method m which a cylindrical con- 
denser is employed as follows. <A closed aluminum tube, °62°™ 
in diameter 18™ long, containing weak radium equally dis- 
tributed along its inside, is made the core of a cylindrical con- 
denser, 2:1" “in external diameter, and leaded to an inch or | 
more in thickness beyond. The aluminum core in question is 
suspended axially from a fine wire leading to a sensitive elec- 
trometer. The voltages here to be measured must of course 
be small, and hence all connecting wires are to be inclosed in 
earthed metal pipes. 

The core in question is then removed from the electrical 
condenser and put into the axis of a dust-free fog chamber . 
where the nucleation (ionization) is found on condensation 
from the contents of the corona; or vice versa. Here there 
are some outstanding difficulties; for the coronas are not the 
same throughout the length of the fog chamber. Even 
immediately around the radium core a single corona may be 
green on one side and red on the other. In a fog chamber 
45% long, the coronas may vary from the glass end to the 
metal end of the chamber, in a way to correspond to from 
100,000 to 200,000 nuclei, respectively, while the radium core 
is fixed in the middle. Inferring secondary radiation, one 
might naturally expect to obtain still larger coronas near the 
metal end, if the radium core (thoroughly sealed) is placed 
there, instead of in the middle of the chamber; but this is not 
the case, the coronas beg markedly smaller than before, 
decreasing uniformly in size, however, toward the glass end. 
As the sealed aluminum tube is within the chamber, this 


88 €. Barus—Standardization of the Fog Chamber. 


behavior is puzzling and needs farther explanation. It is 
clearly of grave importance.* 

These difficulties are inherent in the phenomenon and 
merely exhibited by the fog chamber. The latter has the 
great advantage that enormous nucleations, like millions per 
cubic centimeter, are not excluded. Under these circumstances 
the coronas alone are available for finding the nucleation 
inasmuch as nearly all the particles evaporate before subsiding. 

3. Preliminary Data.—To test the efficiency of the fog 
chamber it is necessary to make a preliminary measurement 
of Thomson’s e. Let the radu of the electrical condenser be 
ft, and “#7, and its length /,; let C (electrostatic units) be the 
capacity of the electric system (condenser and electrometer,, 
together with such auxiliary capacity as may be inserted to 
get a leakage of proper value); let U be the combined velocity 


of the ions in afield of one volt per cm., V the voltage and V the 
change of voltage per second; finally let VV be the nucleation 
given for the identical condenser core when placed in the fog 
chamber. Then for the cylindrical condenser (if natural loga- 
rithms be taken) 


= (CVinR, | R,)/(600 7lU VIN ). 


If V is small enough to keep V/V constant, thé curves 
show this at once. Rough tests using the old cle of my fog 
chamber led to values of about as follows, when C= 130em; 
U =3-2cm/sec.; V the fraction of a volt (less than one- half) 
and the field -7 volts/em. 


V/V=-050 N=185,000 ¢x10"=3-7 electros. units 
V/Ve= 060) N—210,000- 410 43 : 


The irregularities here are in the electrometer, as the con- 
necting wires were not at the time surrounded by earthed 
pipes. On enclosing these, there was less irregularity, though 
the current was not quite proportioned to the voltage even for 
the low values of the latter. In a field of volt/em, V =-%, 
V/V=-040, WY = 150,000 10°xXe=3°8 were’ obtamed: 
When the condenser was disconnected there was no leakage, 
showing the piping to be nearly free from such currents as 
might result from irregular penetration of the gamma rays. 

* As the radium is moved from the glass end to the brass end of the long 
fog chamber, the corona of maximum diameter (maximum nucleation) 
moves at a greater rate in the same direction; so that with radium in the 
middle, the maximum nucleation is already at the brass end, and then dimin- 
ishes. It is surprising to notice the largest corona in the middle of the 
chamber, before the radium gets there. It is also possible to produce mini- 
mum of nucleation in the middle. The maximum rarely coincides with the 


position of the radium. Beta and gamma rays are alone active in these 
curious conflicts of primary and secondary streams. 


C. Barus—Standardization of the Fog Chamber. — 89 


With still higher nucleations VW = 570,000 the data were 
V = ‘123 volts, V=-90 volts, the field being 1:2 volts per 
em, V/V = 137 and 10" e= 3-4 electrostatic units. Thus it 
follows that both positive and negative ions must have been 
caught in the fog chamber. 

4. Other Equations.—The available equations if 7 be the 
electrical current in the condenser, for which the nucleation 
in the annular volume v is 2, while ‘WV is the nucleation in the 
fog chamber without current, > being the coefficient of the 
decay, are (apart from secondary radiation) 


—n = 6(N*—n*)— L/ev, (1) 
SSW (2) 

where (is the capacity of the system, 
I= 9rin UV e/ (log R/R,) (3) 


where V/V is constant for very small voltages. Hence there 
would be a second method of reaching ¢ in “terms of 6, or the 
reverse, if equation (1), where J is essentially a function of 
time, were integrable. Nevertheless the equation is available 
at once if V is large enough to make the current constant. 
In this case one may write, if VV nuclei are found in the fog 
chamber without electrical current, while 2 occur in the con- 
denser with current, 


e= CV / (300r(R,?— R,)lb(N?—n’)). 


Here 7 must be negligible compared with VV. Values so 
obtained (an Exner graduated electroscope suffices) are quite 
consistent among themselves; but the data come out 20 to 30 
too large if 6 = 1:1X10~° is assumed. 

Installing a plate condenser in the fog chamber, I noticed 
that for a charge of 100 or 200 volts the coronas between the 
condenser plates were of about the same character as the 
coronas without, while the large chamber is filled with ions at 
the highest voltages. Possibly therefore such ionization as 
reaches the inside of a condenser by diffusion may account for 
the excessive currents; or there may be increased production 
due to secondary radiation. It is interesting to note that 
potentials of 100 to 200 volts are sufficient to eject dust par- 
ticles from the condenser, very small and not numerous it is 
true, but sufficient to make it possible to catch all the ions 
only after these dust particles have been precipitated in one 
or more exhaustions.* 

5. Conclusion.—The good values of é¢ obtained under 
widely varied conditions in the present very rough experi- 
ments, show that the present method is not unworthy of 
development, with a view to the further measurement of this 


* The complicated conditions encountered here will be restated elsewhere. 


90 ©. Barus—Standardization of the Fog Chamber. 


important constant. For this purpose I am at work on a 
redetermination of the nucleation values of the coronas, using 
as a source of light the virtually monochromatic mercury 
lamp. This is sufficiently intense and the coronas admit of 
the more definite optical interpretation.. 

Elsewhere* I pointed out that for large coronas the greater 
part of the fog particles evaporate ; thus even at 2 = 200,000 
particles per cubic cm., about one-half evaporate and one-half 
subside. Hence the corona method is here alone available for 
counting particles. 1 also showed that in the case of coronas 
the interference phenomenon superposed on the diffraction 
phenomenon may be treated in a way similar to the lamellar 
erating, consisting of alternate strips of thin and thicker trans- 
parent glass; that the given types of coronas must follow 
each other in the ratio of 5, 4, 8, 2, 1,0 for their particle 
diameters and an increasing size of coronas ; that the ratio of 
fog particle diameter and interference plate thickness, dj D, tor, 
the same color minimum in the interferences is d/D = n/(n-1), 
where v is the refractive index, or about 7 to 8 in both eases. 
It must therefore be possible to compute the nucleation cor- 
responding to a given corona at a given exhaustion and tem- 
perature, purely from optical considerations of diffraction and | 
interference, as indicated. I hope to report the results in the 
near future. 


Brown University, Providence, R. I. 


* This Journal, xxv, p. 409, 1908. + Tbid., p. 224, 1908. 


Chemistry and Physics. eaet 


SCQEHN PPETC INTELLIGENCE. 
I. CHEMISTRY AND PHYSICS. 


1. Volumetric Method for Chlorates.—The best known volu- 
metric processes for determining chlorates are the iodometric 
‘method and the method depending upon the oxidation of a fer- 
rous salt. The latter is the more rapid of the two, and it has 
been extensively employed. To complete this reaction, however, 
boiling for about ten minutes is necessary. KNecur has recently 
described a new method for this determination, based upon the 
use of titanous chloride for the reduction. This reagent acts 
more rapidly than a ferrous salt, so that no heating is required. 
The procedure is as follows: 50° of standard titanous chloride 
solution (of which 1°°=:0015 of iron or thereabouts) are run 
into 5°° of concentrated hydrochloric acid contained in a conical 
flask through which a current of carbon dioxide is maintained. 
Then 10° of the chlorate solution (1£ in 500°°) are added. After 
a lapse of not less than three minutes, potassium sulphocyanide 
is added, and the excess of titanous chloride estimated by titra- 
tion with iron alum solution until a permanent red color is 
obtained. For the estimation of chlorate in bleaching powder 
the available chlorine due to hypochlorite is estimated in the 
usual way by adding potassium iodide and starch and titrating 
with hydrosulphite in the presence of acetic acid. A second por- 
tion of the solution is then titrated with titanous chloride, the 
result giving total chlorine from hypochlorite and chlorate.— 
Jour. Soc. Chem. Industry, 1908, 434. H. L. W. 

2. Atomic Weight of Radium.—Mme. Curie’s first deter- 
mination of this atomic weight gave the number 225. Subse- 
quently she obtained witha larger amount of material (about four 
decigrams of radium chloride) the higher number 226-2. T. E. 
TuHorpPeE has now repeated the determination of this interesting 
constant, and has obtained three results, 22.68, 225°7, and 227°7, 
which agree satisfactorily with those of Mme. Curie, although 
he used a much smaller amount of radium chloride, only 6 or 8 
centigrams, for the determinations. Both investigators have 
used the same principle, the comparison of the weight of radium 
chloride with that of the silver chloride produced from it by 
precipitation. To avoid losses by transferring, Thorpe made use 
of small glass-stoppered flasks for all of the operations—weigh- 
ing the radium chloride, dissolving it, precipitating with silver 
nitrate, washing the silver chloride by decantation, and drying 
and weighing in a single flask. Spectroscopic evidence is given 
that the radium chloride was free from all but the minutest 
traces of barium. It had been very carefully purified by the 
usual course of fractional crystallization. There are several 
circumstances which may affect the determination of the atomic 


‘92 | Seventific Intelligence. 


eight of radium. Thorpe states that the chloride gradually 
increases in weight when exposed to the air, apparently on 
account of oxidation by ozone, the presence of which can be per- 
ceived by the odor, and by other tests. Another peculiarity of 
the radium salt is its action upon the vessels containing the 
solution. It gradually changes the color of colorless rock crystal 
vessels to deep purplish black, and these as well as porcelain and 
glass vessels appear to be sliehtly attacked eden with 
the formation of silicates.— Chem. News, xevii, 929. H. L. w. 

3. The Polyiodides of Potassium, Rubidium, and Cuesium.— 
Using solubility methods, together with analyses of the undis- 
solved residues, Foore and CHALKER have determined the poly- 
iodides of potassium, rubidium, and caesium existing at 25°, and 
have found positive evidence of the existence of KI,, KL, RbL,, 
CsI,, and CsI,, while they found no evidence whatever of the 
existence of RbI,, RbI,, Csl, and CsI, which had been supposed 
to exist by Abegg and Hambarger, who used somewhat similar 
physical methods, but did not analyze the residues. It is to be 
noticed, also, that Abegg and Hamburger did not find KL, the first 
of these compounds that was discovered. It appears that while 
Abegg and Hamburger’s work was correct in principle, there 
must have been some irregularity in their solubility determina- 
tions, leading to incorrect conclusions.—Amer. Chem. Jour., 
OOO VION HE Wie 

4. A Volumetric Method jor Copper.—A. process based upon 
the titration of cuprous thiocyanate with potassium iodate solu- 
tion in the presence of strong hydrochloric acid has been worked 
out by Jamieson and others of the Sheffield Scientific School. 
The reaction corresponds to the equation 4CuSCN + 7KIO,+ 
14HCI=4CuSO, + 7KCl+71C1+4HCN +5H,0. The titration is 
carried out in a glass-stoppered bottle with a liquid containing 
about half of its volume of concentrated hydrochloric acid in the 
presence of a little chloroform. The disappearance of the iodine 
color in the chloroform marks the end of the reaction, and it 
is exceedingly sharp and delicate. The presence of filter paper 
does not affect the result. This general method of titration is 
due to L. W. Andrews, but it was not applied by him to thiocy- 
anates, to which it has now been found to be applicable. The 
authors give details for applying the method to copper ores and 
alloys in such a way as to remove interfering substances. Test 
analyses showed excellent results, and the method appears to be 
a very rapid and accurate one.—Jour. Amer. Chem. Soe., Xxx, 
760. Hi. TS ave 

5. Lhermodynamics of Technical Gas- Reactions; by FE. Waser. 
Translated by Arthur B. Lamb. 8vo, pp. 356. London and New 
York, 1908 (Longmans, Green & Co.).—This book consists of a _ 
series of seven lectures which have been considerably enlarged 
for publication. The mechanical theory of heat is developed, as the 
author says, from its very foundations. Then a number of reactions, 
which are important industrially, are treated from a theoret- 


Chemistry and Physics. 93 


ical standpoint in a very thorough manner. The lectures are: 
(1) The latent heat of chemical reaction and its relation to reac- 
tion energy; (2) and (3), Entropy and its significance in gas 
reactions. (+) Examples of reactions which proceed withont a 
change in the number of molecules. (5) Some examples of reac- 
tions involving a change in the number of molecules. (6) Deter-. 
mination of the specific heat of gases. (7) Determination of 
gaseous equilibrium, with a theoretical and technical discussion. 
H. W. F. 

6. A Search for Fluctuations in the Sun’s Thermal Radia-- 
tion through their Influence on Terrestrial Temperature ; by 
Srmon Newcoms. Trans. Amer. Phil. Soc., xxi, pp. 309-387.— 
The problem of variations in solar heat radiation as affecting. 
terrestial temperatures is discussed in a thorough, impartial way 
in this memoir. The conclusions are none the less interesting 
because essentially negative in character, although the observa- 
tions made by Langley and later at the Astrophysical Observatory 
at Washington have seemed to indicate a different result. New-. 
comb shows that a careful study of the annual departures of tem- 
perature over many regions in equatorial and middle latitudes, 
indicate a fluctuation corresponding with the period of solar 
spots. The maximum fluctuation, however, for tropical regions. 
is only 0°13° C., or, in other words, the amplitude of the change 
is 0°26° C., less than one-half degree Fahrenheit. The corre- 
sponding fluctuation of the sun’s radiation is, hence, concluded. 
to be 0:2 of 1 per cent on each side of the mean. In addition, 
‘there is some inconclusive evidence of changes having a period 
of about six years, which may be plausibly attributed to changes. 
in solar radiation. Apart from these changes the evidence at 
hand indicates that solar radiation is subject to no change pro- 
ducing a measurable effect upon terrestrial temperature; the 
magnetic, electric, and radio-active emanations may be left out of 
account, as their thermal effect is inappreciable. The ordinary 
terrestrial phenomena of temperature, rainfall and winds are 
thus uninfluenced by changes in the sun’s radiation. That wide 
changes of temperature may occur, as those noted in 1903, when 
the temperature in Russia and Siberia, for example, was more 
than 20° F. above the normal, is interesting, but it is argued that 
these fluctuations cannot be attributed to changes in the radia- 
tion from the sun, because they do not extend to regions (i. e. 
the equatorial) where such changes would have their greatest 
effect. 


I]. Grouoey. 


1. Karly Devonic History of New York and Eastern North 
America; by Joun M. Crarke. N. Y. State Museum Mem., 
IX, pp. 366, pl. 48+. Albany, 1908.—To the important series of 
New York State Museum publications is now added the sump- 
tuous memotr bearing this title, the peer of a notable line of pred-- 
ecessors and decidedly the crowning achievement on the part. 


94 Scientifie Intelligence. 


of one of James Hall’s most distinguished pupils. Critics are 
sparing nowadays in bestowing the terms monumental upon a 
scientific treatise, the adjective so often savors of hyperbole ; 
and yet in the present case it must be allowed that any less 
superlative epithet would fail to denote the high character of 
Dr. Clarke’s magnum opus. Space is here lacking for an ade- 
quate estimate of its contents, and the reviewer is perforce con- 
fined to a general appreciation. | 

The work ‘is first of all a vast repository of information on a 
singularly complex subject, embracing great wealth of detail. 
To the practical student also, it commends itself as a digest in 
which all the essential facts of its theme are collected, classified, 
analyzed and interpreted with scrupulous exactness. Finally, 
the net result is systematized with the critical poise and acumen 
that mark the experienced investigator who brings to his task a 
broad grasp of cosmic problems, and whose mental attitude has 
been determined by the successful conquest of a large group of 
nature’s secrets. The book betokens all these qualities and more; 
for on the humanistic side one is delighted by the literary skill 
with which the author handles his material, besides many a 
brilliant discursus on manners, customs, history, scenery, of an 
enchanting region. Naturally, as the title indicates, the chief 
objective aims of the memoir consist in a presentation of the 
essential features of the geology and paleontology of that time- 
interval in the Paleozoic of eastern North America with which 
our author is perhaps the most familiar, and on which he is 
recognized at home and abroad as an accomplished master. 
More particularly it deals with the origin and relations of the 
Lower Devonian rocks of Gaspé peninsula, with an elaborate 
discussion of their fossil remains, an investigation for which the 
author’s earlier researches on the Guelph and Naples faunas of 
New York State served as a fitting prelude. 

This volume is the fruit of several years of thoughtful study 
and patient effort, and it may be safely said that a work of this 
kind will never be superseded. And yet, such are the manifold 
resources and complexity of his material that the author assures 
himself and his readers that “the facts here brought together are 
but suggestions for further study of this fertile field.” In this 
connection there comes to mind a German saying: “ Wir sind alle 
Schuldner unserer, Vorginger,” for in speaking of earlier workers 
Dr. Clarke pays a generous tribute to the memory of Logan, 
Billings, Dawson and other pioneer heroes of the Canadian Sur- 
vey. Of Sir William’s Geology of Canada it is said: “To a 
student of Gaspé geology, this is the compendium and guide.” 
And with reference to Palaeozoic Fossils we find this: “It is 
our good fortune to be able to cite this work so frequently that 
our pages may almost seem its memorial.” Yet we fancy that 
these twain explorers who handed along the torch are the very 
ones who would be most surprised at the large increment of knowl- 
edge and perfection of method that are signalized by the hand- 


Geology. 95 


some volume before us, illustrated by its beautiful lithographs and 
numerous full-page illustrations, several of which are in poly- 
chrome and most excellently done. Among _ paleontologists 
Plates A and £B will command attention from being camera 
drawings by the author that recall his previous illustration of 
Dictyospongia i in Memoir 2 of the same series. 

One hundred pages of letterpress are devoted to an exploita-_ 
tion of the geology and physiography of Gaspé, this part being a 
substantial elaboration of the author’s preliminary sketch of the 
geology of Percé (published in the Report for 1903), and the 
remainder of the volume consists of a technical discussion of the 
Gaspé invertebrate faunas. Upwards of 70 new species are 
described, and the characters of others are redefined. Especial 
interest attaches to the author’s discussion of the origin, distri- 
bution and relations of Lower Devonic faunas, and the lines of 
their dispersal and invasion over different areas, this phase of 
the subject being treated with great ingenuity, and displaying 
keen philosophical judgment. It is to be noted, for instance, 
that the origin of the Gaspé sandstone is explained on the theory 
that it “‘ was an Old Red lake in the same sense as those of Scot- 
land and that in which the Oneonta and Catskill sands of New 
York were laid down.” Due prominence is given to the fact that. 
late stages of the Oriskany betray a large percentage of incom- 
ing migrants which form, as it were, the advance guard of the 
next organic invasion. Dr. Clarke accordingly concludes that 
the original determination of the age of the Gaspé beds as prac- 
tically equivalent to the Oriskany of New York is insufiicient, and 
he is able to trace a passageway by which the Hamilton contin- 
gent of this fauna entered the region from the Appalachian gulf, 
moving eastward amid lagoon conditions along the Atlantic 
border and thence into western Europe. This whole matter is 
admirably summarized at pages 250-252, and as the work is one 
that requires to be consulted by all students of the Devonian era, 
we cannot do better than recommend the reading of this section 
and others germane to it at first hand. Ose 

2. Publications of the United States Geological Survey.— 
Recent publications of the U. 8. Geological Survey are noted in 
the following list (continued from voi. xxv, p. 150): 

ToroerapHic ATLAS.—Sixty-five sheets. The sheets, 38 in 
number, embracing Connecticut with portions of the adjacent 
States have been collated and bound in a permanent volume 
which will be of great value to those interested in the region 
named. ‘These volumes have been distributed by Congressman 
Lilley, the plan having originated with R. W. Thompson, private 
secretary to Senator Hawley. Bulletin No. 117 is bound in with 
the volume. 

Foutos.—-No. 154. Winslow Folio, Arkansas——Indian Territory. 
Description of the Winslow Quadrangle; by A. H. PurpvueE. 
Pp. 6, with 3 maps. 


96 Scientific Intelligence. 


No. 155. Ann Arbor Folio, Michigan. Description of the 
Ann Arbor Quadrangle ; by I. C. Russettand Frank Leverett. 
Pp. 15, with 3 maps. 

No. 156. Elk Point Folio, South Dakota,—Nebraska—Iowa ; 
Description of the Elk Point Quadrangle; by J. E. Topp. Pp. 8, 
with 3 colored maps. 

No. 158. Rockland Folio, Maine; by Epson S. Bastiy. Pp. 
15, with 5 colored maps. 

Buttetins.—No. 319. Summary of the Controlling Factors 
of Artesian Flows; by Myron L. Futter. Pp. 44, with 7 plates 
and 17 figures. 

No. 325. A Study of Four Hundred Steaming Tests made at 
the Fuel-Testing Plant, St. Louis, Mo., in 1904, 1905, and 1906; 
by Lester P. BRECKENRIDGE. Pp. 196, with 76 figures. 

No. 326. The Arkansas Coal Field ; : by ArTaur J. Coutisr, 
with Reports on the Paleontology by Davin Wuire and G. H. 
Girty. Pp. vi, 158, with 6 plates and 29 figures. 

No. 327. Geologic Reconnaissance in the Matanuska and 
Talkeetna Basins, Alaska; by StpNey Paige and ADOLPH 
Knorr. Pp. 71, with 4 plates and 4 figures. 

No. 328. The Gold Placers of Parts of Seward Peninsula, 
Alaska, including the Nome, Council, Kougarok, Port Clarence, 
and Goodhope Precincts; by ArtHuur J. Coniier, Frank L. 
Hess, Puiip 8. Smits, and Atrrep H. Brooks. Pp. 3438, with 
11 plates and 19 figures. 

No. 329. Organization, Equipment, and Operation of the 
Structural-Materials Testing Laboratories at St. Louis, Mo. ; by 
Ricnarp L. Humpsrey, with preface by Joserpn A. Hommes. 
Pp. vi, 84, with 25 plates and 9 figures. 

No. 330. The Data of Geochemistry ; by Frank WiGGuEs- 
WORTH CLARKE. Pp. 716. See vol. xxv, p. 458. 

No. 831. Portland Cement Mortars and their Constituent Mate- 
rials. Results of Tests made at the Structural-Materials Testing 
Laboratories, Forest Park, St. Louis, Mo., 1905-1907 ; by Ricu- 
arp L. Humpurey and WiiiaM Jonpay, IR. Pp. vii, 130, with 
20 plates and 22 figures. 

No. 382. Report. of the U.S. Fuel: Testing Plant, at St. Louis, 
Mo. January 1, 1906, to June 30, 1907. JosEPu "A. Horates in 
charge, ip, 1-299, 

No. 333. Coal-Mine Accidents; Their Causes and Prevention. A 
preliminary statistical Report ; by Cuarence Hatyi and WALTER 
O. SNELLING, with introduction by Josrpu A. Hotmes. Pp. 21. 

No. 334. The Burning of Coal without Smoke in the Boiler 
Plants: a Preliminary Report; by D. T. Ranpatit. Pp. 26, 
with 3 tables. | 

No. 336. Washing and Coking Tests of Coal and Cupola 
Tests of Coke, conducted by the U. 8. Fuel-Testing Plant at St. 
Louis, Mo. January 1, 1905, to June 30, 1907; by RicHarp 
Mo.tenkE, A. W. Betpren and G. R. DeztamateR, with intro- 
duction by J. A. Hotmes. Pp. 1-76. 


Geology. 97 


No. 389. The Purchase of Coal under Government and Com- 
mercial Specifications on the Basis of its Heating Value: with 
Analyses of Coal delivered under Government Contracts ; by D. 
WeWANDALL. ~ Pp. 27. 

No. 343. Binders for Coal Briquets. Investigations made at 
the Fuel-testing Plant, St. Louis, Mo.; by James E. Mitts. 
Pp. 56 with | figure. 

W ATER-SUPPLY AND IreiGATION Paprers.—No. 212. Surface 
Water Supply of the Great Basin Drainage 1906; by E. C. La 
Rus, THomas Grieve, Jr., and Henry THurretu. Pp. iv, 98, 
with 2 plates and 2 figures. 

No. 213. The Surface Water Supply of. California, 1906. 
With a Section on Ground Water Levels in Southern California. 
(Great Basin and Pacific Ocean Drainages in California and Lower 
Colorado River Drainages) ; by W.B. Crarp. Pp. 219, with 4 
plates and 2 figures. 

No. 214. Surface Water Supply of the North Pacific Coast 
Drainage, 1906; by J. C. Stevens, Rospert Foiuanspes, and HE. 
C. La Rue. Pp. vi, 208, with 3 plates and 2 figures. — 

No. 215. Geology and Water Resources of a Portion of the 
Missouri River Valley in Northeastern Nebraska ; by G. E. Con- 
DRA. Pp. 59 with 11 plates. 

No. 217. Water Resources of Beaver Valley, Utah; by 
Wits T. Ler. Pp. 57, with 1 plate and 3 figures. 

3. Maryland Geological Survey ; Witt1am Burtock CLarRkK, 
State Geologist. Volume VI, pp. 572, pls. 51, figs. 19, with map. 
Baltimore, 1906.—Part I of the present report on the physical 
features of Maryland, by William Bullock Clark and Edwin B. 
Mathews, is a somewhat elaborate compendium of the geological 
and geographical features of the state, including the physiography, 
geology, mineral resources, soils, climate, forestry, etc. ‘The report 
on the highways of Maryland, by A. N. Jobnson, and state highway 
construction, by Walter Wilson Crosby, make up Parts III and 
IV, while Part V is a history of the origin, boundaries, etc., of 
the counties of Maryland. A new geological and soil map 
accompanies these descriptions. A large part of the material 
contained in this volume has been previously published as de- 
scriptive matter relating to Maryland’s exhibit at the Louisiana 
Purchase Exposition and in its present form will reach a greater 
number of readers. IB 1. Ge 

4. Iowu Geological Survey, Samun. Carvin, State Geologist, 
James H. Luxs, Assistant State Geologist. Volume XVII; Annual 
Report for 1906, with Accompanying Papers. Pp. 588, pls. 
_ 62, figs. 44. Des Moines, 1907.—The report for 1906 deals largely 
with the economic resources of the state and includes a study of 
Portland cement and the geology of quarry products in general. 
There are included analyses of coals, limestones, chalks, clays, 
shales, and marls and an account of tests of the Iowa building 
stone. 

A new geological map of the state, compiled by T. E. Savage, 
accompanies this report. H. H.-G. 


Am. Jour. Sci.—Fourtu SeRies, Vor. XXVI, No, 151.—Juxy, 1908. 
[eRe 


98 _ Seiten tific Intelligence. 


5. Wisconsin Geological and Natural History Survey, E. A. 
Bires, Director.—The Wisconsin Survey has recently issued four 
road pamphlets, of 24 to 54 pages each, by the Highway Engi- 
neer, A. R. Hirst. The topics discussed are : Earth roads, Stone 
and Gravel Roads, the Earth Road drag, and Culverts and Bridges. 

6. Geological "Map of Cape of ” Good Hope.—Four new 
sheets of the Geological Map, by A. W. Rogers and A. L. Du 
Torr, have been issued. No. 42 covers the region between 
Kimberley and Hopetown, and No. 52 an area from Mafeking 
westward to longitude 24° and from the Molopo river southward 
to latitude 26° 30’. No. 49 is the Kuruman and No. 50 the 
Vryburg sheet. H. EG 

7. Variations Periodiques des Glaciers, XIIme Rapport, 
1906 ; par Dr. Ep. Bruckner et E. Murer. Extrait des Annales 
de Glaciologie i1, March, 1908, pp. 161-198. (Fréres Borntrae- 
ger Hditeurs). Berlin, 1908. Also Zeitschrift fiir Gletscher- 
kunde ; Band II, Heft 3, pp. 161-234. Berlin, 1908.—The report 
on elaciers for 1906 presents facts similar to those of the last 
tive years. In the eastern Alps, of twenty-six glaciers reported 
three remained stationary and one was advancing. The Italian 
glaciers are all in retreat, and in Savoy and in the Pyrenees many 
small glaciers and even certain névé fields have disappeared. In 
the Bukhara mountains one glacier in the Pierre le Grand chain 
has a marked advance. In the glaciers of North America there 
has been a decided shrinkage, with the exception of the remark- 
able glacier in Yakutat Bay, described by Tarr. H. E. G. 

8. The Ceratopsia ; by Joun B. Hatcurr, based on prelimin- 
ary studies by Oruniet C. Marsu. Edited and completed by 
Ricuarp 8. Lutt. Monograph XLIX, U.8. Geological Survey, 
pp. 198, pls. 51, and 125 figures in the text. Washington, 1898.— 
This volume constitutes the third of six extensive monographs 
planned by the late Professor O. C. Marsh on the extinct verte- 
brates of North America. One, on the Odontornithes, or toothed 
‘birds, was published in 1880 ; asecond on huge horned mammals, 
the Dinocerata, in 1884, while the present volume on the horned 
dinosaurs has just aa The remaining three are in course 
of preparation. 

Under Professor Marsh’s direction, many of the illustrations 
for these volumes were made both lithogr aphic and on wood, and 
a series of preliminary notices, largely descriptions of new species, 
were published from time to time in this Journal. In the present 
instance, the notices were 16 in number, the lithographic plates 
19, while of the woodcuts there were 28. 

‘After Professor Marsh’s death, in 1899, Professor H. F. Osborn, 
who succeeded the former as Vertebrate Paleontologist to the 
U.S. Geological Survey, assigned the Ceratopsia volume to Mr. J. 
B. Hatcher, the discoverer and chief collector of this remarkable 
group of reptiles. Hatcher in turn carried the work forward, add- 
ing many of the remaining text-figures and plates as well as 157 
printed pages of the text. After having completed the morphol- 
ogy and specific descriptions, Mr. Hatcher died on July 3, 1904, 
and it became necessary for a third author to pick up the threads 


Geology. 99 


of the task and carry the work to completion. This has been 
done by Professor Richard 8. Lull, of Yale University, who has 
edited the whole volume and, in addition, added the final section 
including the generic and specific summary; the geology and 
physiography of the Ceratopsia localities and the discussion of 
the evolution, probable appearance, habits and causes of extinction 
of the race. 

The book includes an extensive biographical notice of Mr. Hat- 
cher by Professor Osborn, who expresses the hope that the vol- 
ume may prove to be a lasting monument to the rare and noble 
spirit of John Bell Hatcher. 


ILL. MisceLLAnrous Screntiric INTELLIGENCE. 


. |. Harvard College Observatory, Epwarp C. PIcKERING, 
Director.—Recent publications from the Harvard Observatory 
are noted in the following list (continued from vol. xxv, p. 460) : 

Annats.—Vol. XLIX, Pt. II. Peruvian Meteorology; by Soton 
I. Bartey. Observations made at the Auxiliary Stations 1892- 
1895. Pp. 107-232 with 80 tables and 2 figures. 

Vol. L. Revised Harvard Photometry. A Catalogue of the 
Positions, Photometric Magnitudes and Spectra of 9110 Stars, 
painiy of the magnitude 6°50, and brighter. Observed with the 

2 and 4 inch meridian photometers. Pp. iv, 252, with 4 tables. 

Vol. LXI, Pt. I. Researches of the Boyden Department ; by 
~WixiiaM H. Pickerine. Pp. vi, 103, with 3 plates. 

CircuLaR No. 136. Comparison Stars for U Geminorum. Pp. 3. 

2. Publications of the Allegheny Observatory of the Western 
University of Pennsylvania. 

Vol. I, No. 3. The Orbit of «a Andromede. By Rosperr H. 
Baker. Pp. 17-24. 

Vol. I, No. 5. The Orbit of Algol from Observations made in 
1906 and 1907. By Frank Scuiesincer and R. H. Curtiss. 
Pp. 25-33. 

3. Carnegie Institution of Washington.—Recent publications 
of the Carnegie Institution are given in the following list (con- 
tinued from vol. xxv, p. 163): 

No. 66. High Steam Pressures in Locomotive Service ; by 
Wituram F. M. Goss. Pp. 144. 

No. 82. The Physiology of Stomata; by Francis E. Luoyp. 
Pp. 142, with 14 plates and 40 figures. 

No. 85. Index of Economic Material in Documents of the 
States of the United States. New York 1789-1904. Pre- 
pared for the Department of Economics and Sociology of the 
Carnegie Institution of Washington ; by ADELAIDE R. Hasse. 
Pp. 553. 

iiss the same for Rhode Island; by ApErz~atwEr R. Hasse. 
Pp. 95. 

No. 92. Guide to the Archives of the Government of the 
United States in Washington; by Craupr H. Van Tyne and 
Watpo G. LeLranp. Second Edition, revised and enlarged, by 


100 ~ WSeventific Intelligence. 


W.G. Leann. (Revised edition of Publication No. 14.) Pp. 
Ri e2y. 

4. Maryland Weather Service; Ww. B. Crarx, Director. 
Volume Ii, pp. 515, with 169 figures and 24 plates. Baltimore, 
1907.—The first volume of the Maryland Weather Service; issued 
in 1899 (see vol. ix, 234), contained a general account of the phys- 
lography and meteorology of the state. In the present work the 
climatic features of the city of Baltimore are made the subject 
of detailed study, this being based upon a series of observations 
extending over a period of nearly a century. The systematic 
thoroughness and minuteness with which Dr. O. L. Fassig has 
gone into this subject, and the fulness with which the various 
topics are illustrated by tables, figures and charts, makes the 
volume, as a whole, almost unique in meteorological literature, 
and gives it much more than a local interest. The introduction 
(pp. 21-26), on the operations of the service, has been prepared 
by the Director. 

5. The Apodous Holothurians. A Monograph of the Synap- 
tide and Molpadiide ; by Huserr Lyman CrarK. Smith- 
sonian Contr. to Knowledge, vol. xxxv, 231 pages ; 13 plates.— 
This is a very much needed and useful work on a group of holo- 
thurians that is comparatively little known. All the genera and 
Species are described, the original descriptions and figures 
being copied when authentic specimens were not available. 
The anatomy and histology are given pretty fully in many cases. 
It includes many new species, mostly from the deep seas, and 
some new genera, as well as new limitations of old ones. There 
is a full biblography and index. Ay eye 

6. American Association for the Advancement of Science.— 
The summer meeting of the American Association will be held at 
Hanover, N.H., from June 29 to July 4. The American Physical 
Society will meet in conjunction with Section B. Various interest- 
ing excursions, to the White Mountains and elsewhere, have 
been arranged. . 

7. International Catalogue of Periodicals.—Professor KE. 
Guarini has recently issued a catalogue of 4063 periodicals 
classified by country and subject. MM. Dunod and Pinat, Paris, 
are the publishers. 


OBITUARY. 


M. Avserr Larparent, the eminent French geologist, died in 
May last at the age of sixty-seven years. 

Professor Kart Aucusr Moésius, Director of the Zoological 
Museum at Berlin, died on April 26 at the age of eighty-three 
rears. 

: M. Pierre J. A. Bikcuamp, the veteran French chemist, died 
on April 15 at the age of ninety-two years. 

Dr. Roserr Cuatmers, of the Canadian Geological Survey, 
died on April 9 at the age of seventy-four years. 

Witiiam A. Anruony, Professor emeritus of physics, electri- 
cal and mechanical engineering at Cooper Union, New York 
City, died on May 29 at the age of seventy-three years. 


Relief Map of the United States 


We have just prepared a new relief map of the United 
States, 48 x 32 inches in size, made of a special composition 
which is hard and durable, and at the saine time light. The 
map is described in detail in circular No. 77, which will be 


sent on request. Price, $16.00. 


WARD’S NATURAL SCIENCE ESTABLISHMENT, 


76-104 College Ave., ROCHESEEM ER: Nw Y. 


Warps Natura Science EstaBuisHMent 


A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 


DEPARTMENTS: 
Geology, including Phenomenal and Physiographic. 


Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, ete. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, etc. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Wards Natural Science Establishment, 
76-104 College Ave., Rochester, New York, U.S. A. 


CONTENTS. 


Art. I.—Emission of Electricity from the Induced Activity 
of Radium ; by W. Duane 


If.—Ilvaite from Shasta County, Cal.; by B. Prescott... 


Ili.—Mechanics of Igneous Intrusion (Third Paper) ; by 
RA. Dary 


IV.—Rhinocerotide of the Lower Miocene ; by F. B. Loomis 
V.—Description of Tertiary Plants; by T. D. A. Cocx- 


eee r- ee ee ewe ww ew He ewe eee 


VII—New Fossil Elateride from Florissant ; 
WiIcKHAM 


alt Wer ion of Iron and Vanadium in the Presence of 
One Another ; by G. Epear 


1X.—Estimation of Cerium in the Presence of the other Rare 
Earths by the action of Potassium Ferricyanide ; by 
P. Ee Brownie and GH: Eh, PAIMER 22) (3 oe 


X.—Estimation of Chromium as Silver Chromate; by F. A. 
GoocH and 1, EL W emp cus ee eee 


XI.—Standardization of the Fog Chamber by the aid of 
Thomson’s Electron ; by C. Barvs 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Volumetric Method for Chlorates, Knecut: Atomic 
Weight of Radium, THorpsz, 91.—Polyiodides of Potassium, Rubidium, 
and “Caesium, Foorr and CHAaLKER: Volumetric Method for Copper, 
JAMIESON : Thermodynamics of Technical Gas-Reactions, ¥. HABER, 92.— 
Search for Fluctuations in the Sun’s Thermal Radiation through their 
Influence on Terrestrial Temperature, S. Newcoms, 93. 


Geology—Early Devonic History of New York and Eastern North America, 
J. M. Cuarkn, 93.—Publications of the United States Geological Survey, 
95. —Maryland Geological Survey: Iowa Geological Survey, 97.--Wis- 
consin Geological and Natural History Survey: Geological Map of Cape 
of Good Hope, A. W. Rocmrs and A. L. pu Torr: Variations Périodiques 
des Glaciers, XIIme Rapport, 1906, Ep. BRucKNER et EH. Murer: Cera- 
topsia, J. B. HatcuEr, 98. 


Miscellaneous Scientific Intelligence—Harvard College Observatory : Publica- 
tions of the Allegheny Observatory of the Western University of Penn- 
sylvania: Carnegie Institution of Washington, 99.—Maryland Weather 
Service: Apodous Holothurians, H. L. CLarxk: American Association for 
the Advancement of Science: International Catalogue of Periodicals, 100. 


Obituary—M. ALBERT LAPPARENT: Karu A. Mosius: M. Pierre J. A. 
BECHAMP: ROBERT CHALMERS: WILLIAM A. ANTHONY. 


Librarian U. S. Nat. Museum. 


Wor. XXVI. | AUGUST, 1908. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Eprron: EDWARD S. DANA. 


| - ASSOCIATE EDITORS 
Proressorns GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or CamMBripcE, 


PROFESSORS ADDISON FE. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor GEORGE F. BARKER, or PHILADELPHIA, 
Proressorn HENRY S. WILLIAMS, or IrHaca, 
Proresson JOSEPH S. AMES, or BaLtTrMorge, 

Me. J. S. DILLER, or WASHINGTON. 


FOURTH SERIES 
VOL. XXVI-[WHOLE NUMBER, CLXXVI] 
No. 152—AUGUST, 1908. 


NEW HAVEN,. CONNECTICUT. 
1908 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 


Published monthly, Six dollars per year, in advance. $6.40 to-countries in the 
Postal Union ; $6.25 to Canada. Remittances should be made eithér Siy ‘monéy-orders, 
registered letters, or bank checks (preferably on New York banks ; 


OUR SUMMER BULLETIN 


We have just issued a 10-page Bulletin covering in brief every department 
of our stock, the additions to which have been so numerous it was absolutely 
necessary that we publish a new list, as it is impossible in an advertisement 
to say much on this subject. Send for this list. As a special inducement 
we are allowing a discount for sales made during July and August of 20 per 
cent. on Common Minerals, and 10 per cent. on Fine and Rare Minerals, 
Polished Specimens, and cut gems. The departments treated in this list 


> 


are ; 


Showy Minerals, 
Rare Minerals, 
New Finds of Minerals, 
Gems, Rough and Cut, 
Geological Specimens, 
Ore Collections, 


Indian Relics, etc. 


Reconstructed Sapphires (the latest discovery). 


These stones have the same hardness and specific gravity as a genuine 
stone and the color and beauty is equal to that of a genuine sapphire. We 
have them in stock from 4 to 2 k. at $8 per carat. 


No PETE RELY 


81—83 Fulton Street, New York City. 


THE 


AMERICAN JOURNALOF SCIENCE 


[FOURTH SERIES.] 


——_____ $9 —__—__— 


Arr. XII.—The Réle of Water in Tremolite and Certain 
Other Minerals; by E. T. Auuen and J. K. CLemenrt. 


Object of the Investrgation.—A study of the composition of 
tremolite was undertaken with several objectsin view. In the 
first place, it belongs to the series of calcium and magnesium 
metasilicates, all the other known members of which have 
already been studied in this laboratory. Secondly, it is the 
simplest known amphibole with the exception of kupfferite, 
and consequently affords an advantageous opportunity for 
further study of the relations which exist between the amphi- 
boles and the pyroxenes. For a complete investigation of this 
kind, pure minerals are necessary, and since natural minerals 
can rarely be, classed as such, we sought to prepare tremolite 
synthetically. But, the ordinary methods proving prea 
to the task, we proceeded to astudy of the natural mineral, 
order that we might find out what elements were really essen- 
tial to it, as well as what physical conditions were necessary to 
its existence. 

One of the most important questions which presented itself 
in this connection was whether the mineral must be synthe- 
sized by wet or dry methods; whether it was hydrous or an- 
hydrous. Some preliminary work which we had done proved 
that it was incapable of existence above about 1000°-1100°, a 
temperature at which it is still in the solid state. Attempts to 
form it by heating a glass of the same composition below this 
temperature, or by rapid cooling of the melt, failed, indicating 
not only that the natural mineral must have been formed from 
solution, a conclusion in accord with geological evidence, but 
further, that it could be obtained in no other way. At first, 
molten salts were tried as solvents, on account of the difficulty 
of working with water at temperatures much above the 


Am. Jour. Sci.—FourtH Series, Vou. XXVI, No. 152.—Aveusr, 1908. 
8 


102. Allen and Clement—Role of Water in Tremolite. 


ordinary. These efforts also proving unsuccessful, the idea 
suggested itself that the mineral was perhaps hydrous and 
therefore must be made by the agency of water, in spite of 
the general opinion among mineralogists that tremolite is 
anhydrous. 

Material for Study.—In order to establish the true compo- 
sition of tremolite, we made a careful selection of specimens 
from five different sources. The color of the specimens indi- 
eated that they contained very little iron and the microscopic 
examination showed them quite free from inclusions, though 
some of them required separation from comparatively coarse 
grains of other minerals intergrown with or adhering to them. 
This was done with heavy solutions, either potassium mereurie 
iodide, or mixtures of methylene iodide and benzene. After 
it had been ascertained by the microscope that each specimen 
was as pure as it was practicable to get it, it was carefully ana- 
lyzed. The results are given in Table I. An inspection of 
the five analyses (I-V) shows that water* is present in all of 
them and ranges from 1°72-2°50 per cent, averaging 2°17 per cent 
in the two purest specimens. It may therefore be regarded as 


TABLE I].—ANALYSES OF NATURAL TREMOLITES. 


Localities 
1 2 3 4 4) 6+ Tt 
Ham Ossin- Gouver- Rus- Kd- Rich- 

Island, ing, neur, sell, wards, ville, Lee, 

Alaska INS Ye: INE OYE New. Nave NONE Mass. 
S10, -- - -58°59 5:35 56°92 56°36 58°24 54S 57 69 
Biss ce Sree ‘07 10 06 "O4 Gi. 14 
evi O ees “LO 1s | 1°65 1°88 °60 1°30 1:80 
Bes) «co. te alt "36 “61 "43 18 none 
1S 6 ee 3 a: none 1:01 none 22 55 
mn soes aes “Oil ae 04 1:28 07 trace 


MgO __.24-78 23°87 23°81 22°97 25°16 24°85 24°12 
CAO 82 13°95 14°02 12°51 12°82 10°85 12°89 13°19 


RiaiO sk V2 "42 1:22 “94 82 67 "48 
= Caen 10 ae “60 “74 19 ‘D4 "22 
MeO es 2 2:37 2-27 2-01 1:72 2-30) Zo) 166 
, Oh eas none =allat 1:03 1-23 "24 17 37 
99°95 99°80 100°21 100°38 100535 THOS) Stee 
O equiv- 
alent to | 
iH 20° ‘00 ‘05 43 9) 10 "32 "15 


99°95 99°75 99°78 . 99°85 100°25. . 99°87 = HO0r0g 


* The water was determined by absorption by calcium chloride. See 
Hillebrand, Analysis of Silicate and Carbonate Rocks, Bull. U. S. Geol. 
Surv., 305, p. 62. 

+ Analyses 6 and 7 were made by Penfield and Stanley. 


Allen and Clement—Roéle of Water in Tremolite. 1038 


an essential constituent. While work on this subject was in 
progress, Penfield and Stanley* published the analyses of a 
number of amphiboles, including two tremolites, all made on 
very carefully selected material, in which it was found that all 
contained notable quantities of water and fluorine. While our 
results confirm theirs in regard to water, it may be noted in 
passing that fluorine is entirely absent from one of our speci- 
mens and occurs in quite insignificant quantities in one or two 
others. It is not, therefore, to be counted an essential constit- 
vent. 

The role of the water.—The next question to present itself 
is: What part does the water play in the constitution of the 
mineral? Is it chemically combined or dissolved, i. e., does it 
escape at one or more temperature 
points with a sudden change in phys- 1 
ical properties, or is it given off grad- 
ually through a range of temperatures, 
the physical properties varying with 
the change in composition 4 

Tammann,t in attacking a similar problem 
with the zeolites, used the method originated Jp 
by Van Bemmelen. The powdered minerals, 
in small beakers, were left to stand, at con- 
stant temperature (19°), in desiccators with 
sulphuric acid of various concentrations, the 
vapor pressures of which were known, until 
the weight became constant. This method 
had the disadvantage of removing only a frac- 
tion of the total water, 1-1 per cent to 23 per 
cent, according to the mineral, leaving one 
still in doubt about the major part of the 
water. This difficulty is obviated by the more 
direct method ot Friedel,t who heated the 
zeolites, at progressively higher temperatures, 
in a current of air which was saturated with 
water at an approximately constant tempera- 
ture, this temperature remaining nearly the 
same in all the experiments of any one series. 
He found thus for several zeolites true 
equilibria at every temperature. 

The Apparatus.—Some preliminary experi- 
ments on tremolite suggested that the vapor pressure, even at 
higher temperatures, would probably fall practically to zero 
within a limited time. We therefore adopted Friedel’s method, 

* This Journal (4), xxiii, p. 23, 1907. 


+ Zeitschr. Phys. Chem., xxvii, 323, 1898. 
{ Bull. Soc. Min., xix, 363, 1896; xxii, 5 and 86, 1899. 


T 


SSS 


aN 


SSNS 


S 


SSS 


SSSSSSSSSSSSSSSSSSSSSDDArSMN 


Yy 
Y 


G= Air current, T= 
thermoelement. 


104 Allen and Clement—Réle of Water in Tremolite. 


only heating in a current of dry instead of mozst air.* The 
air was dried by concentrated sulphuric acid. The apparatus 
in‘ which the dehydration was earried on is shown in fig. 1. 
It is a cylinder of Berlin porcelain, closed at one end and 
glazed on the inside to make it impervious to gases. The 
upper end is molded so as to form a groove, into which fits 
the iron cover. There are also two inner covers of porcelain, 
each 1™ thick, which rest on lugs baked on to the inner wall 
of the cylinder. These keep the temperature more nearly 
constant and protect the iron cover from excessive heat. All 
three covers are perforated near the edge to allow the passage 
of two porcelain tubes. One of these, which is closed at the 
bottom, reaches down to the charge and carries the thermo- 
element. The other is open at both ends, reaches nearly to the 
bottom of the cylinder, and admits the current of dry air. One 
of the tubes may be fitted closely to the iron cover by a “ fibre” 
ring, the other may be left loose enough to allow the escape of 
the air. If it is desired to use some other atmosphere in the 
furnace, mercury may be poured into the groove to more 
effectually prevent any air from leaking in. The crucible 
whicn holds the tremolite rests on a platinum triangle which is 
supported by a hollow cylinder of fine white clay. This whole 
apparatus in an upright position is then slipped into a platinum 
resistance coil furnace which envelopes it to within 2 of the 
top. The furnace is heated by a storage battery and the tem- — 
perature can be regulated very closely indeed for a period of 
many hours. | 

Conditions of HExperiment.—There was no difficulty in 
maintaining the temperature within 5° without much atten- 
tion, except when the same battery was required intermit- 
tently for other work. In such cases there were sometimes 
aberrations of 10° or more. As the time of experiment is not 
essential, a fall in temperature is of no importance; a half 
hour or more at a temperature as much as 5° below the 
point aimed at was not counted. On the other hand, if the 
temperature ran 5° or more above the point, the work was 
rejected unless the charge underwent further loss at the same 
temperature on the following day. The loss of water was so 
very slow that an aberration of this kind scarcely ever affected 
the results. Besides, our object was only to determine the 
form of the curve with sufficient accuracy to settle the ques- 
tion whether the loss of water was continuous or discontinuous. 

Regarding the conduct of an experiment only a few words 
of explanation are needed. The mineral was generally in the 
form of a rather coarse powder, ground only fine enough to 
pass a screen of 100-120 meshes to the linear inch, because 


* The question of equilibrium is raised on p. 117. 


Allen and Clement—Réle of Water in Tremotite. 105 


fine powders are known to absorb moisture from the air.* 


The crucible containing the powder was introduced into the 


furnace, rapidly heated to the required temperature and kept 
there during the rest of the working day. Then it was quickly 
transferred to a sulphuric acid desiccator, cooled and weighed. 
The time of cooling was usually about 20 minutes. There is 
some chance of error here, in that the mineral may, have 
absorbed moisture or air during the cooling. Friedel} found 
that a nearly dehydrated chabazite absorbed 2°34 per cent of 
air when left in a desiccator several hours. Such errors must 
be small in tremolite, for the time of cooling seemed to make 


2 


Loss in milligrams. 


We ee 
600 80 


Temperature. 200 400 


ro 


Oo Tooo 


Curve showing loss of water in tremolite from Gouverneur, N. Y. The 
losses are too small but the form of the curve will be seen to resemble closely 
those in fig. 3, where the work was more exact. 


no difference in the apparent weight and the substance did not 


show a tendency to gain on the balance except after heating at 
the lower temperatures where the losses were small. 
The heating at each temperature was continued until prac- 


tically constant weight, i. e., until the loss in 5-6 hours was not 


more than 1-3 tenths of a milligram. 

Curves showing loss of water with temperature.—The first 
work was done on the tremolite from Gouverneur, N. Y. The 
results are plotted in fig. 2. It was afterwards found that the 
work was quite imperfect because, instead of heating to a 
constant weight, what was considered an ample period of time 

*Day and Allen, this Journal, xix, 127, 1905. Mauselius, Arsbok Sver- 
iges Geologiska Undersékning No. 3, 1907. W. F. Hillebrand, private 


communication. Much more complete treatment in paper about to be pub- 
lished. 


+ Bull. Soc. Min., xxii, p. 15, 1899 ; see also Hillebrand, loc. cit., p. 50. 


106 Allen and Clement—Role of Water in Tremolite. 


was allowed for complete dehydration. The losses are: there- 
fore too small, but since the general form of the curve is — 
similar to that of the others, and the form of the curve is the 
most important point, the curve is given for the sake of com- 
pleteness. The curve for the tremolite from Ham Island, 
Alaska, the purest of all the specimens, was determined 
with the greatest degree of completeness. On account of the 
tedious nature of the work,* fewer points were determined on 
the other curves, and in none of them was the dehydration 
carried to the end, but only so far as to show beyond doubt 
that all the curves were of the same general form. An excep-- 
tion should be made of the specimen from Russell, N. Y. 
(IV-IV, fig. 3), which contains less water and more iron than 
any of the rest. There is an interruption in the continuity of 
the curve between 835° and 865° where no water appeared to 
be given off. A partial explanation may be found in the fact 
that oxygen appears to be absorbed here; at any rate the 
powder, at first slightly greenish, becomes brown on continued 
heating. This absorption might partly offset the loss of the 
water. The data from which all the curves are plotted are 
found in Tables 2, 3 and 4. 


TaBLe IJ.—Loss or WATER BY Heat. TREMOLITE (Ham Island, Alaska). 


/ 2 grams powdered mineral taken. 
Tem- 
Time Reena Weight | Loss Time | per- | Weight | Loss 
ature 

Oe nrs: £5 26-685) 200 1/23 hrs.)890°| 26°6753] °0112 
1152 “ 500°| 26°6798) :0067 || 2/3 “© 1890°) 26°6751) °0114 
AS) oe 500°) 26°6798| 0067 || 3)5 “© 1894°| 26°6744| -0121 
15 “| 750°|26°6781| -v084|| 4142 “ |890°| 26-6743) “O122 
254 “| 750°| 26-6780) -0085 || 1/2 —  |920°| 26°6739| “0126 

2 | 
6 “| 801°-26-6781| -0084|| 216 “ |918"| 26-6722) -0143 
9144 13 805°! 26°6778 "0087 37 “ 1918°| 26 6721] °0144 
1/5 66 1I845—850° 296°6774 0091 | 1/6 a 933° 26°6701 "0164 
2'6 66 | 845° 296°6776) *0089 2\6 ce 933° 26°6680| °0185 
1|4 cc 863° 26°6772| “0093 3/6» a0 933° 26'6667 "0198 
916 pee 363° 96-6769 0096 46 “¢ 1930°| 26°6658| °0207 
ae SH Bene DReene ‘101 || 2 {9882] 26°6646, -0219 
Al | Sele ae 613 ~ |930°| 26:6644] -0221 
45 it 860° | 266761} :0104 
D0 teas) 862°] 26°6763] -0102 
1/44“ 877 | 26°6758| -0107 
QiQd 6 | 875°| 26°6756, -0109 


* Tf any fluorine escaped during the dehydration of the other tremolites, it 
must have been very little, for the microscope did not detect any lack of homo- 
geneity, while, when the Gouverneur tremolite was heated 240 consecutive 
hours at about 950°, the loss was 0°5 per cent in excess of the water and the 
mineral showed a very evident change. 


Allen and Clement—Réle of Water in Tremolite. 107 


TABLE IJI.—Totat Loss AT DIFFERENT TEMPERATURES. TREMOLITE 
(Ham Island, Alaska). 


: P= Percentage Per cent of 
aus cae OEE loss total water 
2 102 hrs. 500° GeO ha 3S 14°5 

LO TSUE oie Brot “49 18°3 

gi « S05 a Sere 43 18°8 

11 “  1845-850° Td Sead 45 19°6 

26 ss SES 5 a LOZA: 5° D2 22°5 

a ss Soe ee NO; 9.3> & *o4 23°4 

15 es BOF 2D es ‘61 26°38 

15 198-9207) 4a § Bae 31°] 

32 9S 0—9G3 ee Doan 6 Vee AT°7 
Proportional | 
loss for 2 gr. | 

5 84“ POOc ts = NOs Oia ic 4-4 20) 9°5 

gi“ SU Oe tee ESO te 52 "26 11:2 

10 eo AN Or Deel Oem a6 6°2 31 13°4 

re < SOO | epics Rs 6-9 85 14:9 

fos < GO0> 22024)“ 8°2 ‘41 Ieee 

(eS ee YP as on oa ek S°7 “43 18°8 

Dae | BOO es Q Dri ace 9°0 °45 19°4 

10 fe DIRS 84-2: 66 13°7 “68 - |: 929-6 

about | 100 GEO") shT5:8n < 46°3 2°31 100°0 


Interpretation of the curves.—lt will be seen that all the 
curves (fig. 3) rise very slowly and in nearly a straight line 
until a point approximating 850° is reached, when they bend 
strongly upward. The point seems to vary somewhat with 
the composition of the mineral. The curves appear to be 
smooth ; still one might suspect that so strong a change in cur- 
vature indicated some abrupt change in the physical or chemi- 
eal condition of the mineral. The microscopic evidence shows, 
however, that the crystal form, with such optical properties as 
can be quantitatively measured—extinction angle, index of 
refraction—remain almost unchanged. In the purer specimens 
from Ham Island and Ossining, and in that from Gouverneur, 
there is no essential difference between the mineral before and 
after heating, except in the development of bubbles through- 
out the mass, which increase in number as more water is lost. 
In the Edwards specimen, a beautiful parting parallel to the 
base continued exactly as it was before heating. There is a 
change in the color of the specimen from pink to dull green- 
ish, winch i is probably due to the absorption of oxygen by the 
manganese oxide, 1:28 per cent of which is present. This, 
however, has nothing to do with the bend in the curve, for 
the color change was just as noticeable in a portion of the min- 


108 Allen and Clement—f6le of Water in Tremolite. 


eral which had been heated below 850°. The water in all the 
specimens is lost gradually as the temperature rises without 
any sudden change of properties or loss of homogeneity.* It 
cannot, therefore, be chemically combined, even though it is 


: Cee ee 

2 a 
zo : 2.2 ee ee 
3° a 


20 
: eee eal iS 
3° a 

; OT ae ie ia 
Io - 


bdo 
° 


Loss in milligrams per 2 grams 
xe) 


al 
° 


Temperature. 200 400 600 800 1000 
I. Tremolite from Ham Island, Alaska. 
II. ye cS OSSiming. aN avs 
ITI. gd ‘Edwards, N. Y. 
IV. pe ‘* Russell) NSW. 


* Making the above-mentioned reservation regarding the specimen from 
Russell, N. Y. 


Allen and Clement—Réle of Water in Tremolite. 109 


TABLE [V.—TotTau Losses OF WATER AT DIFFERENT TEMPERATURES. 


: ‘ emper-.| Loss | Percent | Per cent 
Tremolite from aule eee mg. loss Beco 

Ossining, N. Y. 113 hrs.| 500° LOe ie end 24°7 
2 er. taken eS 840-5 ° 16°5 °82 33°39 
29% © | 870-5° Legis) 89 39°4 
Gis © | 904° 2G elon 59-2 
95S | 928° 37°6 1°88 85°1 

Gouverneur, N. Y. 100° ahs? 

2 gr. taken 200° 3°3 

| 320° 45 

| 608° ee 

805° 9°8 

880° al gyi 

920° 13°7 

980° 20 
Russell, N. Y. 12 hrs. 500° ee "38 22°4 
2 gr. taken 10 | 800° 970 | °45 26°2 
8 ae eg 9°4 47 27°3 
Ain. BABS 9-4 "47 27°3 
~ Co EOS 2 9°4 "47 Mee 
| Narre 202 12) yal 41°4 
Bawards, N.Y.° |: 11.“ | 500° 9°9 ‘50 19°8 
2 gr. taken ple O00) tlie tio "59 23°8 
plese Odo ale 14 | AGO ii O48 
BS COMA ea 14°4 QE ea 2 BES 
peers} 905° 21°2 | 1:06 | 42-4 


given off so very slowly at a temperature of 900°. That it is 
mechanically held seems entirely improbable, for there is no 
indication of a spongy structure to be found by microscopic 
analysis. If capillary pores exist they are submicroscopic. 
The phenomenon is in all probability molecular ; the water is 
therefore te be regarded as dissolved, and the mineral as a 
solid solution. Mineralogists and chemists are wont to regard 
the retention of water at a high temperature as proof of chem- 
ical combination, but all ideas agree that a true hydrous com- 
pound cannot lose water without becoming inhomogeneous. 
The behavior of tremolite is comparable with that of ‘the zeo- 
lites in the two essential points above mentioned. In the 
latter, however, the quantity of water is very much greater, 
and presumably for this reason the change in birefringence 
and volume which they undergo when dehydrated is much 
more noticeable. In the zeolites, as in tremolite, dehydration 
is very slow and requires in some cases a temper ature of 500° 
for its completion. 


110 Allen and Clement—Roéle of Water in Tremolite. 


Friedel’s data for chabazite, analcite and mesolite are plotted 
in figs. 4 and 5. The similarity in the form of the curve of 
mesolite to that of tremolite will be seen at once. Friedel did 
not class the zeolites with solid solutions, but Tammann did so, 
and as such they are now generally regarded. They have 
remained as a unique class of minerals. The behavior of trem- 
olite now shows that the zeolites are not the only ones which 


4 
2. 


18 


16 


I0o 200 300 ! 400 500 
Curves showing loss of water from analcite (1) and chabazite (IT) at differ- 


ent temperatures. Plotted from Friedel’s data. Bull. Soc. Min., xix, p. 376, 
1896 ; xxii, p. 14, 1899. 


contain dissolved water, and it occurred to us that the class 
might not be uncommon. 

Dissolved water in other minerals.—From this standpoint, 
quartz, wollastonite, garnet, adularia, kupfferite, diopside and 
beryl were studied. They were coarsely powdered to avoid 


Allen and Clement—foéle of Water in Tremolite. 111 


condensation of moisture from the atmosphere, and then 
heated. Water-clear quartz from Middleville, Herkimer 
County, N. Y., ground to 40 mesh and dried thoroughly at 
110°, lost only 0°10 per cent of its weight on blasting. Trans- 
parent crystals of adularia from St. Gothard, Switzerland, 
treated in the same way, lost 0°12 per cent; wollastonite from 
Natural Bridge, N. Y., lost 0°27 per cent, and lime garnet 
from Piedmont, Italy, lost 0-26 per cent. These losses are 
-¢o0 small to be of much interest in this connection, but the 
remaining minerals, kupfferite, diopside and beryl, were found 
to contain much lar ger quantities. 

Kupfrerite.—The specimen examined was from Edwards, 
N. Y., where it occurs intergrown with the tremolite, from 
which it was separated by heavy solutions. It is prismatic 
and fibrous, straw-colored or white, has an index of refraction 
y = 1°62, and shows parallel extinction. A portion was ana- 
lyzed and the results are appended. The amount of this was 
small and the portion which was experimented on was obtained 
afterwards and was somewhat purer. 


Calculated for MgSiO; 


Analysis which kupfferite approaches 
=) Seema 59°29 phd ee eee 60 per cent 
i) 03 Ma ac3 354 A) hg 
4 Bee 59 
EA eee ees 29 
(D2) die ae 06 
i aes 271 
ee 2) 30°98 
io) ae as 1°26 
ae one: Si) 

4) REE See 19 
a "20 
ee ee 3°80 
99°83 

O equivalent to F ‘08 
99°75 


Heated in dry air, the mineral behaved as follows: 


TABLE V. 


Charge, 2 grams 


Time of Tempera- Total loss Loss per day 
heating ture in mg. in mg. 

6 hours 400 5°9 5*9 

34 oe ee 5°2 tt 7 

65. 2c 5°8 + °6 


112 = =Allen and Clement—Réle of Water in Tremolite. 


TABLE V (continued). 


Charge, 2 grams 


Time of Tempera- Total loss Loss per day 
heating ture in mg. in mg. 
4+ hours 600 6°5 “i 

6 ce 6¢ 79 a7 

6 ce (5 8:0 °8 
64 66 ce 9:0 1:0 
54 « i 9°4 4 

6 ce (55 9°9 “5 
64 (%5 66 10°5 6 
65 (13 (59 10°9 “4. 
63 (35 (<3 11°3 “4 
Ga vy 12°0 ‘a 

9) 


Curve showing loss of water from mesolite at different temperatures. 
Plotted from Friedel’s data. Bull. Soc. Min., xxii, pl. opposite p. 89, 1899. 


After about 60 hours’ heating at 600°, the mineral had 
0) » : 
therefore lost a 0-6 per cent of water and was still losing | 


at about the same rate, viz., about °5™S per day. An estima- 
tion of the vapor pressure of the water over the mineral was 
made by measuring the rate of flow of the air through the 
furnace, taking into aceount the water which escaped during 
the same time. During a day of six hours, this amounted tu 
1570°, while the average loss of water was about ‘5™%, which, 
under these conditions, would occupy a volume of approxi- 
mately 1°. The partial pressure of the water vapor would 


Allen and Clement—fRoéle of Water in Tremolite. 1138 


therefore be about 1/1500 of an atmosphere or about 0°5™ of 
mercury. As it appeared that the loss of water under these 

conditions goes on indefinitely, a new series of experiments 

was made in which the mineral was heated in air which had 
been bubbled through 65 per cent (by weight) sulphuric acid 

having a vapor pressure at 25°, about the room temperature, 
of 8™™, The results follow: 


TaBLE VI. 
Time of Tempera- Total loss Loss per day 
heating ture in mg. in mg. 
6 hours 600° 12°8 "8 
= 9 66 12°5 we 
G= ce ce 13°3 °S 
; ee &< 13°7 “4 


It will be seen that the average loss is practically the same 
as before. At this point, a small portion of material was 
removed from the crucible and examined microscopically. No 
essential change had taken place in its optical properties. 

The remainder was now ground fine enough to pass a screen 
containing 150 meshes to the linear inch, and a new charge of 
—1°6428 grams was taken. This was heated at 820° in an atmos- 

phere saturated with water vapor, which at the temperature of 
the room should have a partial pressure of about 23™™. The 
following are the results : 


TABLE VII. 

Time of Tempera- Loss Loss per day 
heating ture in mg. in mg. 

54 hours 820° 13°9 13°9 
ios a6 17°5 3°6 

6 ce ¢ 1 8°4 0:9 
es a 19°4 1:0 
See & 19°6 0°2 

64 44 66 19°7 O'1 


At this stage, the mineral having lost altogether 2°05 per 
cent of water, or 50 per cent of the total quantity, another 
portion was removed and examined microscopically. It still 
remained kupfferite, though a secondary change had taken 
place, due probabiy to the oxidation of the manganese. The 
color had become dull green, and dark brown patches, partially 
transparent, were visible on some crystals. This secondary 
change made further experiments useless. The material was 
probably absorbing oxygen, in which case the total loss would 
not represent all the water which escaped. The homogeneity 
of the substance is preserved then during the earlier stages of 
dehydration at least, though the experiments did not prove 
that the loss of water was continuous. If this were the case, 
however, and the water in kupfferite were dissolved, we can 


114 Allen and Clement—fole of Water in Tremolite. 


readily understand how, by the rapid cooling of a melt of the 
composition Mesi0,,* there is formed an anhydr ous substance 
having the properties of an amphibole and very closely resem- 
bling kupfferite i in particular, though the latter contains nearly 
4 per cent of water. 

It has already been stated that the amphiboles analyzed by 
Penfield and Stanley all contained water. The following are 
their results : 


Actinolite, Greiner in Tyrol, H,O =i 
ef Russell, N. Y., s = WEGe 
Krager6, Norway, (6 Se 
a Pierrepont, N. Y., Bieri 

Hornblende, Cornwallis, N. Y., == leae 
i. Renfrew, Ont., OS eee 
r. Ellenville, N. Y., == one 


More recent results by Blasdale confirm these figures and 
include also glaucophane :+ 


Actinolite, Berkeley, Cal., H,O above 100 = 1°784 
= San Pablo, Cal. iy inte 5) 6 
Tremolite, ag ue (oO Ses 
Glaucophane, a ve <f 6S 6G melas 
6“ 6c 6¢ 66 66 cc — 9°54 


A pargasite from Arroyo Hondo, Santa Clara County, Cal., 
recently analyzed by W. O. Clark, gave 3°16 per cent H, O 
above 100°. 

Two hornblendes analyzed by H. 8. Washington gave results 
as follows :§ 


Hornblende from Linosa Island near Tunis contained 19% H,O 
ef «  Kaersut, Greenland, S 59% H, O 


A hornblende from Beverly, Mass., analyzed by F. E. 
Wright, contained 8:15 per cent H,O.| 

These data are sufficient to show that tremolite, kupfferite, 
actinolite, glaucophane and pargasite all contain water ranging 
in quantity from 1:3 per cent to 3 per cent, most of which is 
retained at 110°. Hornblende also contains water, though 
usually in smaller quantity. In view of these facts it seems 
not unlikely that the water in all of them is not combined, but 
dissolved as it is in tremolite. 

*This Journal, xxii, 406, 1906. At the time of its discovery this was 


regarded by us as a true amphibole, since kupfferite was not then known to 
contain water. 

+ Contributions to the Mineralogy of California; Bull. Dep’t of Geol., 
Uniy. of Cal., vol. ii, No. 11, pp. 833, 384, 338-340. 

{ Paragenesis of Minerals in the Glaucophane-bearing rocks of California, 
J. P. Smith, Proc. Am. Phil. Soc., xlv, 237, 1906. 

§ Private communication. 

|| Tschermak’s Miner. Petrogr. Mittheil., xix, 312, 1900. 


Allen and Clement—Réle of Water in Tremolite. 115 


Diopside from Ham Island, Alaska.—This mineral was 
intergrown with the tremolite from the same locality, and like 
it was very pure. A specimen Te y ground for analy sis had 
the composition : 


Cal. for CaSiO;MgSiO; 


poy Gp pteeaniae Les ae een 54°65 55°6 
Rei coe same. 13 bis 
OPO Beet Ace 2s paces 25°27 25°9 
iMrOy s Soipewne:. . 18°78 18°5 
REO Mins oe 07 E 
Nie Oa eae 03 te 
Bi Qe Sag Been a 2 1°45 aes 
100°38 100°0 


This material being exhausted, another hand specimen of 
the same lot was crushed to 40 mesh, separated from a little 
tremolite and calcite by methylene iodide and benzene, and 
dried at 105°. On blasting it lost 1-01 per cent. The dehy- 
drated mineral was entirely homogeneous and the optical prop- 
erties remained almost unchanged. The formation of bubbles 
was evident, but they were less numerous than in tremolite. 
The curve of loss to 800° was as follows : 


TaBuLeE VIII. 
Charge, 3 grams 
Time Temperature Total loss in mg. 
104 hours 400 3°7 
sie 600 18°3 
12 re 800 24°9 


The water lost was thus 82 per cent of the total water. 

Beryl from Alexander Co., N. C—An analysis of this 
specimen was not made. The material for experiment was 
taken from a single transparent crystal which contained a 
little muscovite, but hardly more than traces. The beryl was 
crushed to 100 mesh because it was anticipated the dehydra- 
tion would be slow and the smaller grains would facilitate its 
escape. The loss in weight on blasting was found to be 2°54 
per cent. By absorption with calcium chloride, the water 
being liberated by fusion with soda, the quantity found was 
2°67 per cent. The mineral after it had been blasted was 
microscopically examined and found to possess all the proper- 
ties of beryl. The bubbles formed were numerous and con- 
spicuous. After the mineral had been heated a comparatively 
short time at 400° it reached constant weight, the loss being 
317%. At 800° the loss continued over a long ‘period without 
showing any signs of ceasing. The results follow: 


116 Allen and Olement—fole of Water in Tremolite. 


TaBLE IX, 
Charge, 2 grams 
Temper- Total loss Loss per 
Time ature in mg. day in mg. 
6 hours 800 14:2 11°] 
54 a ae ; 18°0 3°8 
6 i oY 21°4 3°4 
6 (5 66 93°8 9-4. 
4f 88 ie 24:8 1:0 
64 Ss . ZOme 1°4 
63 ¢ (15 27°9 1he-7/ 
6 ce (15 99°] oY 
4 re ne 30°4 1°3 
4 (15 CC 831°1 a7 
64 66 66 31°4 °3 
a 66 ce 832°9 °8 
64 66 66 33°0 °8 
6 (74 (75 33°6 °6 
6 (15 ce 34°3 7 
6 6¢ 66 84°6 3 
6 (14 (15 34:°9 23; 
63 66 66 36°4 °5 
64 66 6é 36°3 °9 
6 (45 4 36°9 6 


The loss of water at 800° was so slow that it was suspected 
that in dry air it might be indefinite ; in other words, that the 
vapor pressure never would fall to zero. It seemed worth 
while in this case to try another series of experiments in which 
the furnace was traversed by a current of air saturated with 
water at the room temperature,—about 25°. The case was 
hike that of kupfferite, except that beryl undergoes no second- 
ary change when heated in air to 800°, and work with it there- 
fore seemed more promising. After continuing the dehydration 
for eight days, it was found that the loss during that time was 
almost identical with the loss in dry air during the same time. 


TABLE X. 
Temper- Total loss Loss per 
Time ature in mg. day in mg. 
6 hours 800° 15°4 15:4 
4 (54 (45 19°3 3°9 
54 6¢ ce 21°6 Zee 
6 6G (3 93°83 9°9 
af 6¢ (‘GG Deak 3°3 
64 (44 (‘<4 27°6 5) 
5a ee 29°5 9 
64 (15 66 30°7 1°2 


Total loss in 50 h. = 30°7™8. 

A reference to the previous table will show that the same 
weight of beryl lost in dry air duringa period of nine days, or 
51 hours, 30°4"8. The tendency for the reaction to reverse 


Allen and Clement— Réle of Water in Tremolite. 117 


itself, that is, for the mineral to absorb water, was tested in 
another way, viz., after the heating in moist air had been con- 
tinued for 7 days, the loss then being 29°5™£, the process was 
continued at 600° for one day. The gain was but °10™%, or 
practically nothing. On the following day the heating was 
continued at 800°, when the loss was 1°3"8, and finally on the 
next day the heating was again repeated at 600°. The gain 
was only -2™8. Evidently, ther efore, it is impossible to “vet 
equilibrium under such conditions as Friedel found he could 
do with certain zeolites. 

The most obvious conclusion appears to be that the esti- 
mated vapor pressure, which is of the same order of magnitude 
with beryl as it is with kupfferite, is far too low and that it 
would require a long time for the maximum vapor pressure to 
develop, or perhaps the latter would finally reach a state of 
“false equilibrium.” * This raises the question, whether or 
not the curves obtained for tremolite may not represent “ false 
equilibria,’ but the tedious nature of the work at atmospheric 
pressure and the secondary importance of the question after 
the relation of the water to the other components had been 
established, decided us not to carry the matter further. 

Resorption of water by tremolite when heated with water 
in a bomb to 400°.—Although no attempts were made to get 
true equilibrium between fremolite and water vapor, some. 
efforts were made to find whether water was taken up by the 
dehydrated mineral under any conditions. The tremolite from 
Ossining, N. Y., which had been heated to a constant weight 
at 923°, where ‘it lost 85-1 per cent of its water, was then 
soaked in water for 20 hours, dried at 110° and blasted. lite 
“was then found to contain 0°59 per cent of its weight, or 26°7 
per cent of the original water content. It had_ therefore 
absorbed 11°8 per cent. A specimen of the Ham Island trem- 
olite which had lost 47-7 per cent of its water at 933°, was 
heated in a bomb, with water at 400°, for 6 days. It was then 
dried at 110° and the water retained determined by blasting. 
It contained 2°15 per cent, while originally it held 2°31 per cent 
of water. There seems to be no ditticulty, therefore, in revers- 
ing the process when the active mass of the water becomes sufii- 
ciently great. With beryl, however, the results were quite 
different. A portion of this mineral which had lost 1°52 per 
cent of its weight after a protracted heating at 800°, was 
heated with 15° water at 420° for four days. Then the 
beryl was removed and dried at 110°. On blasting 1°7568 gr... 
lost ‘0203 gr.=1:15 per cent. The beryl originally contained 
2°54 per cent water, so that the portion which was introduced 
into the bomb must have had 2°54—1:52=1-02 per cent. 
Hardly any water was therefore absorbed in the bomb. 

* Thermodynamics and Chemistry, Duhem. Translated by Burgess. Wiley 
& Sons, 1903, p. 369. 

Am. JOUR. ES aaa Series. VoL. X XVI, No. 152.—Aveusrt, 1908. 


‘ 


118 Allen and Clement—oéle of Water in Tremolite. 


Summary. 


1. A study of five different specimens of natural tremolite, 
two of them of exceptional purity, proves that all contain water 
ranging from 1-7 to 2:5 per cent. This water is lost gradually 
with rising temperatures without any loss in homogeneity and 
with very slight change in the optical properties. The water 
is therefore not chemically combined, although the mineral in 
the powdered state is not completely dehydrated under 900°. 
It is to be regarded as dissolved water, and tremolite as a solid 
solution. A “diopside from a metamor phosed limestone con- 
tained 1 per cent of water and behaved in practically the same 
way, though presumably the diopside of eruptive rocks is 
anhydrous. 

The amphibole kupfferite and a specimen of beryl contained 
respectively 3°8 per cent and 2°5 per cent of water, which they 
lost very slowly at comparatively high temperatures "(400° 800°) 
-and still retained their homogeneity. With them, however, 
the loss of water appeared to progress so slowly at ‘these tem- 
peratures that the total water could not be driven off in any 
reasonable time. ‘The beryl lost at the same rate for a long 
period, both in dry air and in an atmosphere containing water 
vapor at the partial pressure of about 2387", even though this 
rate appeared to show that the mineral possessed a vapor 
pressure of only about 05°" of mereury. The kupfierite 
showed a similar behavior, but the fact that it suffered a sec- 
ondary change in composition at the higher temperatures (prob- 
ably due to the absorption of oxygen) made the experiments on 
it less satisfactory. 

All these minerals show important points of resemblance 
with the zeolites, with which they may broadly be classed, but* 
in one important particular they differ,—at least, this is true 
of kupfferite and beryl,—they do not give true “equilibrium 
with water vapor at low pressures, while the zeolites under 
similar conditions do so (Friedel). Diopside and tremolite 
seem to give off their water continuously, but not indefinitely, 
with rismg temperatures, though it is quite possible the curves 
represent cases of ‘ false equilibri 1a.’ 

2. Recent swale indicate that all the amphiboles contain 
water. Actinolite, glaucophane, and pargasite contain 1-3-3 
per cent, mostly retained above 100°. The hornblendes also 
contain water, though usually in smaller quantity. These facts, 
taken in connection with the above work on tremolite and 
kupfferite, lead to the suspicion that the amphiboles generally 
contain dissolved water as a characteristic constituent, and are 
solid solutions. 

The authors wish to express their hearty thanks to Mr. F. E. 
Wright, to whom they are indebted for all the microscopic 
data found in this paper. 


Geophysical Laboratory, 
Carnegie Institution of Washington, April 23, 1908. 


G. C. Ashman—Determination of Radium Emanation. 119 


Art. XIII.—A Quantitative Determination of the Radium 
Emanation in the Atmosphere; by Grorau C. ASHMAN. 


Ir was shown by Elster and Geitel* in 1902 that a nega- 
tively char ‘ged wire exposed for a few hours in the air receives 
a radio-active deposit similar in character to the quick-changing 
radium products. The first attempt to measure the amount of 
radio-active matter in the atmosphere was made by Evet in 
1905 in Montreal. The method used consisted in collecting 
the active deposit on a charged wire placed in a cylinder of 
known volume. The results were apparently not very satis- 
factory, since the estimated amount of pure radium necessary 
to keep the emanation constant in one cubic meter of air 
varied from 82X10-" to 28710-" gram. ‘The smaller value 
was obtained from a relatively small cylinder out of doors, 
the other from a large abandoned water tank indoors. The 
same higher value was reached by both cylinders indoors. 
Subsequent experiments by the same authort emphasized the 
objections to the active deposit method. The maximum values 
were sixteen times the minimum, and furthermore this method 
does not furnish direct. proof of the presence of radium ema- 
nation. Eve has recently$ described a rather complicated 
new method of determining. directly the amount of radium 
emanation in the atmosphere. This method depends upon 
the discovery made by Rutherford that radium emanation 
is. readily absorbed by specially prepared cocoanut charcoal. 
The maximum values obtained by the absorption method 
were seven times the minimum, ranging from 18 x107-" to 
127X10-" gram of radium for each cubic meter of air, the 
probable average value being 80X10-*. The weli-known 
experiments of Rutherford and Soddy on the condensation of 
radium emanation suggested the possibility of a quantitative 
separation of the emanation from the atmosphere by means of 
liquid air. The qualitative separation was indeed accomplished 
in 1903 by Ebert.| In my experiments, undertaken at the 
suggestion of Professor H. N. McCoy, air drawn from out of 
doors at ground level was passed through a purification train 
composed of KOH solution, H,SO,, CaCl,, and solid KOH, 
and then through a coil of copper tubing immersed in liquid 
air, and was finally collected in aspirators made of carboys of 
known capacity. The coil was made of copper tubing with 
an outside diameter of 3-2" and walls 0-5" in thickness. 
This was wound concentrically about an axis in such a way as 
to allow ample space between the turns so that every part of 
the coil would be completely bathed in the cooling liquid. 

* Physik. Zeitschr., 1i, 590, 1901. + Phil. Mag., x, 98, 1905. 

t+ Phil. Mag., xiv, 724, 1907. § Loe. cit. 

| Sitzb. Akad. Wiss. Miinchen, xxxili, 133, 1903. 


120 G. C. Ashman—Determination of Radium Emanation. 


The entire coil occupied 75° of space and could be easily 
kept submerged in liquid air in a small vessel. Two hundred 
liters of dry air, free from carbon dioxide, could be drawn 
through the coil at a moderate rate in six hours. At the end 
of that time the coil was allowed to heat up and the volatil- 
ized emanation was transferred to a standardized gas electro- 
scope. This was made of an air-tight brass cylinder of about 
one liter capacity, supporting a gold-leat system. This elec- 
troscope has been in use ‘by Professor McCoy for more than 
two years and has a very smal], almost constant natural leak of 
about 0°148 divisions per minute (whole seale 100 divisions), 
when exhausted and refilled with fresh dry air. The electro- 
scope was standardized by the method described by McCoy 
and Ross,* which consisted in observing the rate of discharge 
caused by t the emanation from a portion of a mineral contain: 
ing a known amount of uranium. This activity observation 
was made just 384 hours after the separation of the emana- 
tion from the oft eval and 3 hours after its introduction into 
the electroscope The amount of radium associated with one 
gram of uranium in a mineral was taken as 3:4 1077. 

The results of four experiments calculated on the basis of 
the amount of radium necessary to maintain the emanation 
constant In one cubic meter of air are as follows: 


(1) 86x10~" gram radium. 
(2) Sei 10ee) | « 
(Byes) Ogre : 
(A) BOO 10 Ae 


These results seem to show a considerable variation in the 
amount of emanation in the air at different times; similar 
variations were found by Eve both by the excited activity 
method as well as by that in which the emanation was sepa- 
rated by means of charcoal. It was possible, however, that the 
variations in my results were due to incomplete condensation 
of the emanation. To decide this question, a second coil of 
tubing exactly like the one described above was joined to the 
fLYSt 5 “both coils were immersed in liquid air, and purified out- 
side air was run through the two coils im series at the same 
rate as in the four experiments above described. The emana- 
tion in the first coil corresponded to 51 10~-" gram of radium 
per cubic meter. Zhe second coil did not contain a trace of 
emanation. This experiment clearly proved that the first coil 
condensed all the emanation in the air that passed through it, 
and showed conclusively that the observed variations were really 
due to variations in the amount of emanation in the air at dif- 
ferent times. Such being the case, simultaneous duplicate 
determinations of the amount of radium emanation in the air 


* J. Am. Ch. Soc., xxix, 1700, 1907. + Boltwood, this Jour., xxv, 296, 1908. 


G. 0. Ashman—Determination of Radium Emanation. 121 


s 


should yield identical results. Such duplicate determinations 
were carried out by dividing the air current which had passed 
through the purification train and passing each half through a 
separate coil. In this way equal volumes of air passed through 
the coils simultaneously under exactly similar conditions. 
When corrections for the lapse of time between the observa- 
tions on the contents of the coils were made, it was found that 
each had collected emanation corresponding to 131x107” 
gram of radium. This furnished additional proof that the 
method can be relied upon for quantitative results. As a 
mean of all my experiments the amount of radium necessary 
to produce the observed amount of emanation per cubic meter 
of air is 96X10 ”, or nearly 10-*° gram. This is about 25 per 
cent higher than the mean value found by Eve by the char- 
coal absorption method. The difference may easily be due to 
the variations in the quantity measured. Neither method is, 
however, entirely above criticism. It seems that aside from 
the rather lengthy and complicated nature of Eve’s experl- 
ments there are two possible sources of error. One is that 
Eve assumes in his calculations that increasing the amount of 
emanation in the air three- or fourfold by the introduction of 
a standard radium solution does not affect the fraction of the 
emanation absorbed by the charcoal. This has not been tested 
experimentally. The other is the fact, not taken into account, 
that the emanation is not completely removed from a radium 
solution by the bubbling method. The application of this 
correction, however, would reduce Eve’s results to a still lower 
value. Perhaps some of the difference between our results 
may be accounted for by the fact that in Eve’s experiments 
the air was taken ata level of the fourth floor of a building, 
while in the experiments described here the air was taken nit 
the earth’s level. In my own experiments the fact that the 
second coil, after the passage of the air through the first, did 
not contain an amount of emanation detectable by our electro- 
scope only proves that under the conditions of the experiment 
the first coil collected all the emanation capable of condensa- 
tion at the temperature of liquid air. The complete conden- 
sation is limited only by the value of the vapor pressure of 
radium emanation at the temperature of liquid air. The 
experiment of Rutherford and Soddy* indicates that the 
vapor pressure below the condensation point is practically 
zero, While Ramsayt observed luminous bubbles passing down 
the walls of the vacuum tube while exhausting a vessel con- 
taining the frozen emanation. This would indicate an appre- 
ciable vapor pressure even at the temperature of liquid air. 
The net results of all experiments show that the amount of 


* Loe. cit. +J. Chem. Soc., xci, 932, 1907. 


122 G. CO. Ashman—Determination of Radiwm Hmanation. 


emanation in the air varies between rather wide limits from 
time to time and notably with atmospheric conditions. The 
high value obtained in my fourth experiment is without doubt 
due to the fact that that determination was made immediately 
after a heavy rain and general thaw, following several weeks 
of freezing weather with an unusual covering of snow on the 
ground. Probably the accumulated emanation was suddenly 
liberated by the rapid melting of the snow and consequent 
softening of the earth’s crust. It.is of interest to note that 
experiment (5) was made during a prevailing high barometric 
pressure, and experiment (6) during alow pressure. The ditf- 
ference in the barometric readings on the two dates amounted to 
20™ of mereury. The other weather conditions were normal. 
A complete study was made of the activity curve of the ema- 
nation collected in experiment (4), which proved it to be iden- 
tical with that of the radium emanation. The activity reached 
the maximum value in about three hours after introduction 
into the electroscope and decreased in the usual way to half 
value in about 3°5 days. This showed that the active material 
consisted only of radium emanation. The conditions of the 
experiment eliminated the possibility of introducing into the 
electroscope any thorium emanation which may have been con- 
densed in the copper coil, since only a few minutes are required 
for thorium emanation to decay to a very small fraction of its 
initial value. The following table indicates the course of the 
activity curve of the emanation in experiment (4). The differ- 
ent times are placed in column (1), and in column (2) are the 
corresponding activities in scale divisions of the graduated eye- 
piece passed over by the gold-leaf per minute. The activities 
are corrected for the natural leak of the electr oscope. 


(1) (2) 
ils Us Ge Ny aie RABIN oy econ es ace “761 
60 i EG er Se ee ee "852 
L263 ee ee Ey ae oe "9638 
180. Se arate eed ale ane 1:100 max. activity. 
19. Hours ee eee ee 927 
2 Gays seater eh ie eae 703 
2°8 aS he res eee Sn (ede 
33583 ee REE Pee hia oe KT NBL. OB A! | "546 
BBD S61 y i ee Seren et eee "490 
Conclusions. 


The results of these experiments show that by cooling atmos- 
pheric air to the temperature of liquid air the radium emana- 
tion in it can be completely condensed and its amount accu- 
rately determined. Six measurements made at Chicago showed 
that the average amount of radium emanation per cubie meter 
of air could Wa, maintained by 1:0X10—" gram of radium. 

Kent Chemical Laboratory, University of Chicago, May 20, 1908. 


R. W. Langley— Determination of Bariwm in Rocks. 123 


Arr. XIV.—The Determination of Small Amounts of 
Barium in Rocks; by Ratpn W. Lanevey. 


In the usual methods of rock analysis, barium is deter- 
mined in a separate sample, and no correction is made for its 
possible interference in the main analysis. I wish to show in 
this article that it is possible to determine barium as sulphate 
in the main analysis for silica and bases, by precipitating with 
sulphuric acid immediately after the separation of silica. 
The details of this method are as follows 

The filtrate from the silica is diluted to a volume of about 
400", and ammonium hydroxide added until most of the 
hydrochloric acid is nentralized. The solution is then heated 
to boiling, and about 2°™* of 25 per cent sulphuric acid is 
added and the solution allowed to stand for about ten hours. 
Barium sulphate separates and is filtered on a small filter, the 
filter paper burned in a platinum crucible, and the residue 
dissolved in abont 5°™* of concentrated sulphuric acid by 
warming over a free flame. As soon as all or nearly all of 
the barium sulphate has dissolved, the solution is cooled and 
poured into about 100™* of water. When the bariam sul- 
phate has precipitated, it is filtered and weighed as usual. 
It is best to allow the solution to stand for ten hours before 
filtering. The second filtrate from barium sulphate usually 
contains iron and should be added to the first filtrate. From 
this point the subsequent determinations may be made as 
usual. 

To test the method, an analysis was first made on a gabbro 
rock free from barium. The methods used were those of the 
geological survey. The results are the average of two or 
more determinations. One gram of material was used for 
each analysis. The high figure for titanium oxide led to its 
repeated deter mination, using two standard solutions, one pre- 
pared from titanium oxide and one from a crystal of rutile. 
The results are as follows: 


BS rOhee er: Fase repron. a, £5 (Nerf 8) 
PMU aee ee er ete ott OG 
JEST) 1 RRS Se ae ee ere Sols 
Jee LO <a BT GS A a 2 Rae 2°08 
Als ela aL cy A chen eee 3-05 
BE co er ae ee 17°31 
SEU See ee ee a 
Wis Oe eee tees a 3°48 
Be Oe eee 0-87 
RUE W @ Aoteae oh Sat Se 4°14 


124 R. W. Langley—Determination of Barium in Rocks. 


P,O,, MnO, Cl, and F were present in small amounts and were 
not determined. Ba, Sr, 8, SO, and CO, were absent. 

To determine the influence of barium upon the results, four 
samples of this rock of one gram each were taken. To each 
was added an amount of BaCl,.2H,O equivalent to five milli- 
grains of barium oxide. The material was fused with sodium 
carbonate and the analyses carried on in the usual manner up 
to and including the separation of silica. In the filtrates 
from two of the silica precipitates, barium was separated by 
the method previously outlined. The other two analyses were 
conducted as usual without regard to barium. The percent- 
age results are as follows. In column five the results obtained 
with the original sample free from barium are given for com- 
parison. 


Barium Barium not Barium 

removed removed absent 

Fe,O, + Al,O, + T10, ues Se god “OC, reabsoo Dot HR ellesdeny 
Bas 55a 220e53 0°56 Sid? > eee 

Ja 669. 30 673) 6: Seem 

MgO OMG ROM SM aaa se ui| 3°48 


It appears that the only determination affected by this amount 
of barium is that. of magnesium oxide. The average of the 
two determinations of magnesium oxide made without remoy- 
ing barium is 0°27 per cent higher than in the original material. 
Assuming that barium is precipitated as phosphate [ Ba,(PQ,),| 
and weighed with the magnesium pyrophosphate in the deter- 
mination of inagnesium oxide, the product of the factor for 
converting magnesium pyrophosphate to magnesium oxide, 
and the weight of barium phosphate derived from five milli- 
grams of barium oxide, equal 0:0024 grams. This accounts 
for the fact that the magnesium oxide figure is only 0:27 per 
cent too igh when 5 milligrams of barium oxide are present. 
The presence of barium did not affect the accuracy of the 


determination of calcium oxide. The method for separating 


barium gives accurate results, and introduces no errors into 
the other determinations. The purification of barium sul- 
phate by solution in concentrated sulphuric acid is necessary. 
In one of the determinations the weight of barium sulphate 
plus impurities before purification corresponded to. 09 sper 
cent instead of 0°5 per cent of barium oxide. 

I wish to thank Prof. H. W. Foote for his advice. 


Sheffield Chemical Laboratory, 
New Haven, Conn., May, 1908. 


/ 


[ety 


Mixter— Heat of Combination of Acidic Oxides. 125 


Art. XV.—The Heat of Combination of Acidic Oxides 
‘ with Sodvum Oxide, and the Heat of Oxidation of Chro- 
mium ; by W. G. Mixtsr. 


- Sean from the Sheffield Chemical Laboratory of Yale Univ. ] 


Iris the purpose of the writer to accumulate data on the 
heat effect of the union of acidic oxides with sodium oxide, 
and to determine if the position in the Periodic System and 
the magnitude of the atomic weight of an element have a 
marked influence on this heat effect. Much has been accom- 
plished by Thomsen, Berthelot and others who have derived 
the heat of formation of salts from the observed heat of neu- 
tralization in solution—a method not applicable in all cases 
to salts which hydrolyse largely. The reaction with sodium 
peroxide avoids errors due to hydrolysis and gives fairly accu- 
rate results, as shown in a previous paper* in which 2Na,O,,C, 
= 133500° was the observed heat and 132500° that derived from 
Thomsen’ s data. Asa test of the method two determinations 
were made and in each rather more than two grams of rhom- 
bic sulphur were burned in a bomb with an excess of sodium 
peroxide. ‘The heat effect for one gram was 5275° and 5267° 
respectively ; mean 5271° and for 32 grams of sulphur, 168670° 
The heat effect of Na,O, SO, is derived thus — 


3Na, OF Het) == 168700° 
3Na, O, 30 — 58200° 
Na,0,S,30 = 226900 
8,30 == LOS 2005 
Na@O,,SO. (= 123700° 
From Thomsen’s data we have 
29Na,S,40 =  328590°. 
9Na,O =  99760°t 
S,30 =  103200° 
Na, O, SO, = La OaOs 


Thomsen used Bekétof’s result for 2Na, O; deForcrand§ 
considers it too high and that 91000° is probably more accu- 
rate. The calculated heat effect of Na,O , SO, will not be 
changed by using this number. 

S. W. Parr| mentioned that oxygen is sometimes liberated in 
combustion with sodium peroxide and the writer has found 


* This Journal, xxiv, 154 

+ Thomsen, There ee Untersuchungen, ii, 204. 
t Ibid., iii, 232. §C. R., exxvii, 1449. 
IJ. Am. Chem. Soc., xxix, 1606. 


126 Mixter—Heat of Combination of Acidic Oxides. 


that it is necessary to allow for oxygen taken up or set free. 
The correction of 1°2° for 1 milligram is based on the heat of 
formation of sodium peroxide from the oxide which according 
to deForerand* is 19390°. For oxygen liberated there is a 
loss of heat which is to be added, and “for oxygen absorbed the 
gain is to be subtracted from the heat observed. The best way 
to find the change in the oxygen content of the bomb is to 
connect it after a combustion with a manometer. To avoid 
excessive detail in the data given of the work only the heat 
equivalent of the oxygen liberated or taken up is stated. 
Most of the work was done with a bomb of 500% capacity 
and in the work on chromium the oxygen correction was large. 
To obviate the correction or make it insignificant a sterling 
silver bomb of 100° capacity was made. It proved to be 
admirably adapted for calorimetric work with sodium peroxide. 
The water eqnivalent of this bomb and calorimeter can was 
109°. The large bomb was used in the experiments in which 
the water equivalent was over 3200 grams, and the small one 
in those in which it was less than 3100 grams. When a 
molten mass is in contact with the cold bomb it solidifies at 
once and the combustion is not complete. Hence it is better 
to put the peroxide mixture into a thin silver cup which is in 
contact with the inner surface of the bomb at only a few 
points. In order to make ignition certain the bomb was filled 
with oxygen, as it was found that with air in it the burning 
iron often failed to start the combustion. The carbon used is 
the firiely divided form made from acetylene and the heat 
effect of its reaction with sodium peroxide is taken as 11100°F 
per gram of carbon. The carbon gives the temperature needed 
to effect the combustion of other substances and also reduces 
the peroxide to the sodium oxide required in the reaction with 
an acidic oxide. The initial temperature of the experiments 
was between 18° and 19°. 


Boric Oxide. 


The heat effect of the combination of boric oxide with 
sodium oxide has been determined. The oxide used in the 
experiments, made by fusing boric acid in a platinum dish, 
was pulverized and weighed in a stoppered bottle. It was 
exposed to the air as short a time as possible on account of its 
hygroscopic character. The reaction of boric oxide on an 
excess of sodium peroxide yields the orthoborate thus : 


3Na,0, + B,O, = 2Na,BO, + 30 


No perborate results, as shown by the following experiment : 
*O. R., exxvii, 574. + This Journal, xix, 434. 


127 


Mixter— Heat of Combination of Acidie Oxides. 
A mixture of 1:314 gram of boric oxide and 5 grams of sodium 
peroxide was heated in an ignition tube. The loss in oxygen 
was 0-950 gram ; calculated 0-901 gram. Were perborate 
only formed no oxygen would have been liberated, and if 
metaborate was the product only one-third as much oxygen 
would have been set free. 


Experiments. 
1. 2 3 

PrarterOxide.. 2. 2 2. 1°269 1°858 1°8862 grams 
Jl) 0-661 1-080 1°0384 °_“ 
Sodium peroxide. ..-- a 20° 20° ss 
Water equivalent of 

572 Gill ee ees 3435° 3465° 3431" 3 
Temperature interval 23019" 4°280° 4°149° 
Heat observed -.-_---- 9202° 14830° 14235° 
Heat of oxidation of 

Sean. ee 8 SS —7337° —11988° —11526° 
Heat of oxidation of 

iron for ignition ---- — 80° — 64° — 80° 
Heat absorbed by oxy- 

Gem Siven: Off 0.2.2 “+ 96° + 60° +131° 

1881° 2838° 2760° 

For 1 gram of B,0, 

uniting with sodium 

Cit Cele eee 1482° 1522° 1463° 


The three results are respectively 1482°, 1522°, and 1463°. 
The average is 1489 for 1 gram and 104200° for a gram mole- 
eule of boric oxide reacting with sodium oxide to form sodium 
orthoborate. 

Note on Boron.—The only thermal data on boron are those 
of Troost and Hautefenille* and Berthelot,+ who determined 
the heat of formation of boron trichloride and tribromide and 
the reaction of these halides with water, and from the results 
they calculated the heat of formation of the trioxide. Since 
they give no analysis of the boron used, the purity of it is 
doubtful. Moreover, Moissant has shown that boron prepared 
by reducing the oxide with sodium or magnesium is not pure. 
He removed the magnesium which the impure boron contained 
by fusion with boric oxide, taking precautions to prevent forma- 
tion of nitride. It may be added that while at work on boron 
it was learned that another investigator, whose results are not 
published, considers that none of the methods described in the 
literature yield pure boron. Some of the observations of the 
writer in regard to the burning of boron are interesting and 


* Ann. Ch. Phy. (5), ix, 74. + Ann. Ch. Phy. (5), xv, 215. 
¢ Ann. Ch. Phy. (7), vi, 296. 


128 Mixter—Heat of Combination of Acidic Oxides. 


may be briefly stated. When a mixture of impure boron and 
carbon was burned in oxygen under pressure the boric oxide 
produced volatilized and condensed as a fine white powder, and 
considerable boron carbide was formed. Impure amorphous 
boron and also erystalline boron containing aluminum reacted 
with explosive violence with sodium peroxide. The heat of 
oxidation of boron may, therefore, be easily found by the per- 
oxide method when pure boron is available. 


Aluminium Oxide. 


The amorphous oxide used was prepared by igniting a pow- 
dery form of hydroxide. For crystalline oxide, crystals of 
corundum were taken. These were pulverized in a steel mor- 
tar, the powder digested with hydrofluoric acid, then sulphuric 
acid was added and the mixture heated until fumes of the latter 
acid escaped. Then the oxide was washed. It was white and 
was found to be free from lime, iron and silica, and to contain 
a trace of magnesia. Both pr eparations were floated j in water 
and only the more finely divided portions retained. In order 
to deterniine the alumina remaining after a combustion the 
silver vessel containing the solid product was placed in half a 
liter or liter of cold water. The fusion dissolved rapidly owing 
to the presence of sodium peroxide. After solution the silver 
piece was removed and an excess of nitric acid added and the 
alumina filtered off. It was washed first with water and then 
with ammonia to remove any silver chloride present. This 
residue of alumina was deducted from that taken for an experi- 
ment. There is nothing in the literature regarding the solu- 
bility of ignited alumina in alkaline solutions other than the 
statement that the more intensely the oxide is heated the slower 
it is taken up by alkalies. In order to learn if the residue of 
alumina mentioned in the experiment is likely to dissolve so ~ 
as to cause an error, the following tests were made with finely 
divided alumina which had been heated in a platinum crucible 
over a large blast lamp. In one test 4 grams of alumina and 
20 grams of sodium peroxide were mixed and about 400° of 
hot water were slowly poured upon the mixture. The violent 
reaction between the peroxide and water gave at once a boil- 
ing concentrated solution of sodium hydroxide. After a few 
minutes an excess of nitric acid was added and the solution 
filtered. The alumina found in the filtrate was 2°5 per cent 
of the quantity taken. In another test about the same quan- 
tities of the mixed oxides were added to the surface of warm 
water. In this case no alumina went into solution. Since the 
solid residues from the combustions were chiefly sodium ear- 
bonate and aluminate, and contained much less sodium peroxide 


Mixter— Heat of Combination of Acidic Oxides. 129 


and alumina than used in the tests mentioned, it is evident 
that any error due to solubility of alumina is insignificant. 
Moreover, varying portions of sodium peroxide do not affect 
thermal results. 


Experiments. 
1 2 
oe oxide (amorphous) =—- 3'357 grams 4°313 grams 
“Sy. ik Festdues 2 — 026 “ == GO 
‘Sao Teackine. a= = Sioa sv ANG 5 0 
wl ELD DLs a a ile eon eee loa iS aio ale ae. 66 
Sadia peroxide. =.= 222-2 - 21° ee 25° e 
Water equivalent of system_. 3528: 0a o e 
Temperature interval .--- ---- 4°245° 4°479° 
fleatwobserved 22-2 5-22.2 221. 14977° 15941° 
«of oxidation of carbon_. —13520° —14363° 
6é ce 66 66 irov a3 005) HOS — 60° 
1397° 1518° 
For 1 gram of amorphous alumina 
combining with sodium oxide 419° 365° 
3 + 
turaiorum oxide (crystalline) 4°517 grams 4:038 grams 
im residue =: Sl LGA os ma ote een 
as Sy reactine 2 3343 3 =i SHO, 26S 
2 ei es i Os809etu, 354 O-814, 6 
Sodium peroxide-..- ---- d Iie 3 ve = 
Water equivalent of sy stem... 3087 ee USO: 4 
Wemperature interval... _..- 3°225° 3°355° 
Blea observed. 25 on Le 9956° 10185° 
‘“¢ of oxidation of carbon-- SS 9035° 
6¢ &é ce 6¢ TOM... <2 EOC — 64° 
945° 1086° 
For 1 gram of crystalline alumina Doone 310° 


In experiment 3 the pressure in the bomb was 16™ higher 
after the combustion than before, and the calculated correc- 
tion for the oxygen set free was 30°. This is not included in 
the result above, as changes in pressure were not observed in 
experiments 1, 2 and 4 with alumina. In experiments 3 and 
4 about two-thirds as much carbon was used ag in 1 and 2. In 
order to find if the ratio of the carbon to the alumina infli- 
ences the result, a calorimetric test was made in which the 
amounts of carbon and amorphous alumina were nearly the 
same as in experiments 3 and 4. The result was the same as 
in 1 and 2, as shown in the following experiment : 


130 = =Mrxter—Heat of Combination of Acidic Oxides. 


Experiment 5. 


esi oxide (amorphous)= V2. ites 4°237 grams 
ge TA ROSIE. fee ee Nee ees —0:195 « 
rectee es RESCH Me ee eae 4°042 0% 
Cat oon (2 RR ee eS he 17 ee Ne. Te eee On 78 inti 
Sodium: peroxide sateasy le. =e eee so) eae 14° 
Woater, equivalent of system: 22e) 2. ee 2947" 
Temperature ciiGeryal 2 os eae bes iene 3°484° 
Heat observers: he. oes ae Nie ae 10267 
* .ofroxidation, Of carbon 222 212 72 2eee — 8635° 
14 66 Co TEE ONG Wee CaP et Graco er —64¢ 
1568° 
For 1 gram of amorphous alumina.___.._--. Jee 


In the reaction, 2Na,O,+C=Na,CO,+ Na, 0, 1 part of car- 
bon produces 5 parts of sodium oxide. In the formation of 
sodium metaluminate according to the equation, Al,O,+Na,O 

=%NaAlO,, the ratio of the quantities of the oxides is 1 to 0° 6, 
ak for the formation of the orthoaluminate three times as 
much sodium oxide is required. The following table of results, 
giving the calories evolved for one gram of “alumina and the 
ratio of the alumina to the sodium oxide, shows that sodium 
orthoaluminate could not have been formed in experiments 3, 
4 and 5, as there was not sufficient sodium oxide produced to 
form it. It should be noted in this connection that too little 
oxygen was set free in the combustions to indicate any material 
difference in the quantity of sodium oxide formed. 


Na,O 
Calories for required to form 
No. of 1 gram Na,.Q 9 ——-—+— — 
Exp. Al.Os C Al.Q3 ' formed NaAlO, Wa aon 
1 419 1-2 3°38 (amor.) Ore 23 a 
2 365 IES: 4°2 s 6°5 2°5 7°6 
3 283 - 0°8 3°3 (crys.) 4° 2s 6° 
4 310 0°8 3°2 5 4° iS 6° 
5 388 0°8 4° (amor.) 4° 2°4 72 


It is evident that the chief product in the reactions 1s sodi- 
um metaluminate, but possibly mixed with other aluminates. 
Assuming that the reaction was essentially the same in all of 
the combustions, we have for the heat of combination of 1 
gram of amorphous alumina with sodium oxide a mean of ex- 
periments 1, 2,and 5 of 390°, and for a gram molecule 40,000°. 
For crystalline alumina it is 30, 000°, Hence the transformation 
of the amorphous alumina into the crystalline form is accom- 
panied with the heat effect of 10,000°. 


Mixter— Heat of Combination of Acidic Oxides. 1381 


Chromium. 


The thermal constants of chromium are of considerable im- 
portance. In Landolt and Bernstein’s Physikalisch-Chemische 
Tabellen, p. 439, the statement is made: Die Bildungswaerme 
der Chromverbindungen kann nicht angegeben werden, weil 
keine Reaction untersucht wurde, an der “metallische Chrom 
betheiligt ist. Then, too, it is an interesting element to study, 
forming basic and acidic oxides, both of which yield stable 
salts. Since chromium and its sesquioxide do not burn in 
oxygen, it is necessary to resort to indirect methods in deter- 
mining the thermal constants of chromium compounds. This 
has been done in solutions by Thomsen, Berthelot, and others. 
The sodium peroxide method i is a better one, and the reactions 
are 

Cr + 3Na,0O, = Na,Cr0, + 2Na,O 
Cr,O, + 3Na,O, = 2Na,CrO, + Na,O 


No perchromate is formed as shown by the following result: 
A mixture of two grams of chromium trioxide and 6 grams of 
sodium peroxide was placed in an ignition tube closed with a 
calcium chloride tube to absorb escaping water. On heating 
gently the mixture glowed. The loss in weight was 0°386 
gram ; calculated 0- 32 gram. If perchromate had been for med, 
less oxygen would have been given off. Moreover, it is im- 
probable that sodium per chromate can exist in a molten mass 
containing sodium oxide. 

To Dr. C. H. Mathewson I am indebted for a fine specimen 
of crystalline chromium made at the Goldschmidt factory. The 
metal was pulverized in a steel mortar and the powder was 
digested with hydrochloric acid to remove the iron. Analysis 
proved it to be free from aluminium and silicon and to con- 
tain 0-7 per cent of iron. The last may have been from the 
mortar. Metallic chromium as a very tine powder will un- 
doubtedly burn readily with sodium peroxide, but heat was 
necessary to effect the reaction with that used, and carbon was 
therefore added to the mixtures. After a combustion the 
product was dissolved in water, the solution made acid with 
nitric acid and the metal remaining was separated and weighed. 


Experiments. 
1 2 3 

Metal taken i225 Fk 2-000 2°5000 2°500 grams 

Pig t EEO UTE Lys ee 0:061 0°0043 0:021 e 

ore DEE. «Yo sche ieee 1°939 2°4957 2°479 sc 
Maeresisrtlin: 3 he Ss ers 1°925 9°4782 D-AGilow 3 
Micertiees ot 6) 2 es Stak gad ae 0°014 0-'O175 OF oa 
emia 0 A se J en 0°2456 0°3767 0°3800 <“ 
sodium peroxide. —.--£22 .~ 20° 20° 20°5 é 
Water equivalent of system 3428: Bd 14: 3487" 5 


Temperature interval . ----- 2°601° =3°510° 3°520° 


182 Mixter—Teat of Combination of Acidic Ouides. 


1 2 3 
Meahiobsenved eo: see. as 8916° 12334° 12274¢ 
“ oxidation of carbon.. —2726° —4181° —4218° 
3 a vO aM 
metal and for ignition — 94° — 90° — 92° 
“ due tooxygenabsorbed —288° —492° 472° 
| 5808° 7571° 7492° 
For1 gram of chromium burn- 
ing with sodium peroxide-. 3012°  3055° 3044° 


In the experiments 1, 2, and 8 a bomb of 500° capacity was 
used. As the correction for oxygen absorbed was large, a 
determination was made with the 100% bomb. The residue 
insoluble in nitric acid was collected on a Gooch filter, dried 
and its weight found. Next the carbon was burned off, and 
finally the weight ot unburned chromium was obtained. The 
pressure in the bomb was 29 less after the combustion than 
before. 


Experiment 4. 


Metal taken: as alee ee ee eee 02°0520 grams 
eee UM OMEN: Oe ae ree en es “OOLS a 
COS Se TR ETAL 52. SF Goh ict eal 8 aes pee 2-05 055) 68 
Chromiuin 206s a ee ee ee 2036) ae 
SD gra SS Cg 0:0143 34 
Carbon stakem io soo ia ee ene 0:36 
a0 Unb urMe dl 7k nother es 0:0017 oe 
36 |ONE Ue Octo lpedtur Nn ake wragrs Pts Teale Sree 0°3144 Ss 
Sodium, peroxide: hs 2o oa ee eee elk oe 
Water equivalent ofthe systems 4 = 2984: ye 
Temperature mterval 935 22 ee ee 3°282° 
Heat observed. Veer weir ae eee 9793° 
OOF OMIAAWOn, OLLear bone res eee —3489° 
pore se es ce LOM Mae MMe tale wee — 23° 
ugier ee ci for somitionay — 26° 
dune to oxygcen/absorbed s3525aa-= — 52° 
620385 
For 1 gram of chromium geese eee 3046° 


Evidently the correction made for oxygen taken up in the 
first three experiments was correct. The results are 3012°, 
3055°, 3044°, and 3046°. In the first one the correction for 
oxygen was not made with the care that it was in the others, 
and hence it is better not to include it in the final value. The 
mean of the other figures is.8048° for the reaction of 1 gram 
of crystalline chromium with sodium peroxide, and for 52°1 
grams it is 158800°. 


Mixter— Heat of Combination of Acidic Oxides. 188 


Chromium Sesquioxide. 


Amorphous chromium sesquioxide was prepared by heating 
an hydroxide. The crystalline oxide was made according tO.” 
Ditte’s* method of melting together equal parts of pure potas- 
sium dichromate and sodium chloride until the evolution of 
oxygen ceased. After cooling, the soluble portion of the prod- 
uet was dissolved in water and the crystalline powder obtained,, 
washed, digested with hydrochloric acid and washed again. 
The crystals were so small that some passed throngh filter 
paper. Under the microscope they appeared unmixed with 
any amorphous substance. Tested by the spectroscope the 
preparation proved to be free from sodium and potassium. 
The following results show the heat of the reaction between 
chromium sesquioxide and sodium peroxide: 


Experiments. 
1 2 3 4 
oe Besquioxide. 2... 4°236 3°831 7°436 6576 grams 
ee unburned  0°062 0°018 0°805 OPO Gers F 
°F * burned - - 4-174 3°813 6631 GAG << 
(LiL LL 2 hee eee eee 0°516 0°456 0°4015 OA bie K 
eee burned ——— 0°007 0-006 0°151 COI2 4S 
SOMERS. 2 8 ee 0°509 0°450 0°2505 Of sc 
perm@emeiopieroxide __-..__-..._.- a 15° 21° 20° e 
Water equivalent of system -.. 2828: 2902- 2936: 3077" eB 
Temperature interval --_--- eos SO fp see Od 2022" 3°038° 
Heat observed -___.. .---- Se 8623° 7844¢ (ts 9348° 
“ of oxidation of carbon. ---- —5650 —4995 —2780 —4584° 
Beer * of iron forignition —16 —10 —62 —48° 
** due to oxygen absorbed or | 
LTTE ES es eae —69 =F. +14 — 30° 
/ 
2888 2769 5751 5686° 
For one gram of chromium sesqui- 
oxide, reacting with sodium + 692 726 867 878° 
2 es ee ee 


Crystalline sesquioxide was used in experiments 1 and 2 
The results are 692° and 726° and a mean of 709° for the heat 
of the reaction of 1 gram of crystalline chromium sesquioxide 
with sodium peroxide. Fora gram molecule it is 108U00°. 

The experiments 3 and 4 were with amorphous sesquioxide. 
The results are 867° and 878° and the mean is 872° for the 
heat of the reaction of 1 gram of amorphous chromium sesqui- 
oxide with sodium peroxide. For agram molecule it is 132000°. 


* C. R., exxxiv, 336. 


Am, Jour. Sct.—FourtH SEriIges, Vot. X XVI, No. 152.—Aveusr, 1908. 
10 


i384 Mixter—Heat of Combination of Acidic Oxides. 


In experiment 3 the considerable quantity of unburned sub- 
stance is due to the fact that the mixture was in contact with 
the cold bomb and was not in an inner silver cup. 


Chromium Trioxide. 


The chromium trioxide was free from sulphuric acid and 
sufficiently pure for the purpose. It was fused, allowed to 
cool in a desiccator and then coarsely pulverized. A little ses- 
quioxide remained after a combustion. The amount of tri- 
oxide equivalent to it was deducted from the trioxide taken. 
As the heat of oxidation of the sesquioxide to the trioxide is 
small the error due to reduction is insignificant. The results 
following show the heat effect of the combination of chromium 
trioxide with sodium oxide. 


Experiments, 


1 2 

Chromium trioxide taken___.__._-- 4°000 4°782 grams 

oc ve RECUCed 2 42a ee 0:097 0°176 me 

ee sd combined 922. -22 3°903 4-606" 2." 
Car Wome ee eae ea et ae eee 0°515 0°523 66 
Sodium perouder ero at - eee 10°6 16° “ 
Water equivalent of system __.-.... 3408° 3504: e 
Temperature anterval 25.22.22 422 2°514° 2°595° 
fleet Observed sae erties serene 8567° 9093° 

Of oxidation ol canbonm 25 2. — 5676 —5805° 

ane rf ‘¢ iron for ignition —62 —625* 


«¢ absorbed by oxygen given off +187 +324° 


3016 3590° 
For 1 gram of chromium trioxide - - 113 Take 


The mean of the two results is 772° for 1 gram and for a 
gram molecule of chromium trioxide it is 77000°. 

The heat of formation of the oxides of chromium is derived 
from the above data, thus: 


oma Oo 4+ Cr = Na CrO.) 2Na Oe) eee 158800° 
aNa Olu: 80. — 3Na, On 4 ot Pies Seen 58200° 
NOs ier + 30 = NaC rOrer te an eee 217000° 
NaO +. €0rO, = Na,CrO) 4. ee ee 


Cr. 4. 30% = CrO: 4 ee ee Oe 


Mixter— Heat of Combination of Acidic Oxides. 135 


3Na,O, + Cr,O,(crys.) = 2Na,CrO, + Na,O +  108000° 


a Orch sO Na Oona eh Poe Le 58200° 
2Na.0 + Cr,0O, + 30 = 2Na,CrO, +. -..---- 166200° 
men a OOO )e =e 2 NTO) er ee oe le 154000° 
GrOxXcrystalime) + 307 = 2CrO, +.) 2s.-.-- 12200° 
MEO Cr Oe 280000° 
Weel (erys) 4-930 = FOr Oo es. 3s 12200° 
cere oO) =. Cr O-(erystallime)) 4°. 267800° _ 
Bees 3: = Cr.O.(amorphous) +. = --...2.--- 243800° 
Amorphous CO, = crystalline-Cr,O, + ..--..-.-« >. 24000° 


Thomsen* found for Cr,H,O,, O,, aq = 2CrO,+18913° and 
Berthelott+ gives Cr,O, precip. +O +eau.=2CrO, crys. +16400°. 
The changes in the oxidation of the hydroxide are different 
from those in case of the oxide and hence the above results 
ean not be compared with that of the writer. They all, how- 
ever, show that the heat of formation of chromium trioxide 
from the sesquioxide is small. Berthelott derived from reac- 
tions in solution the following: OCrO,+K,O=K,CrO,+47800°. 
This appears to be too low when considered in connection 
with the 77000° found for Na,O+CrO, = Na,CrO,, since the 
heat of formation of potassium salts is commonly greater than | 
that of sodium salts. 


Tungsten. 


Metallic tungsten used in the work was prepared by reduc- 
ing the oxide with dry hydrogen at the highest temperature 
attainable in a gas combustion furnace. Even after ten hours 
a little water came off, showing that the reduction was not 
complete. During the first hours occupied in the reduction 
a little ammonia was formed from the atmospheric nitrogen 
contained in the hydrogen, but the reduced metal was free 
from nitrogen. The test was made by heating a mixture of 
the metallic powder and soda-lime. No ammonia was given 
off. The tungsten present in the metallic state was determined 
by finding the increase in weight when a weighed amount of 
the metal was oxidized by heating in air and finally in oxygen. 
The tungsten equivalent to the oxygen taken up was 98°14 per 
cent. [ron was present to the extent of 0-07 per cent, leaving 
1:79 per cent by difference of oxide of tungsten as WQO,. 
Undoubtedly only the lower oxides were present and there 


* Thermochemische Untersuchungen, ii, 464. + Thermochemie, ii, 272. 
¢ Ann. Ch. Phys. (6), i, 195. 


1386 = Mixter—Heat of Combination of Acidic Owides. 


was iess than 98 per cent of metallic tungsten in the prepara- 
tion, but the lower oxides give heat when oxidized. Hence 
we may assume without essential error that the thermal effect 
is proportional to the amount of tungsten, which is equivalent 
to the amonnt of oxygen taken up. After each calorimetric 
experiment the product in the bomb was dissolved in water 
and the small residue remaining was separated. It dissolved 
completely in nitric acid, showing that no metallic tungsten 
remained. The following experiments give the heat of burn- 
ing tungsten in sodium per oxide; 


Experiment 1. 


Punosten C241 x) 00814 te eee 8088 grams 
W ater equivalent of system ........____- 3596" < 
Bodiam peroxidegs sey. 2, ee eee One ¢ 
Mempevature inter vale ss see eee 2°859° 
Heat, observed 3596 )<-2°8593) = oe = 10281¢" 
“« of oxidation of iron in tungsten and 
Used Or someon se 1k te eee —157° 
10124° 

ord cram ok tumor sten): esse 2 ee eee 12528 


Hxperiment 2. 


ihunesten.. 6563) < 10-081 am eee 8377 grams 
Water equivalent of isy stem 992 === eee 3552: “¢ 
Sodium peroxide: 4. 5.06 5 i as eee 25° “ 
Temperature mmtervall: =. sas Sees Gee 3°020° 
tleat observed 35523" x 02) eases 10727° 
‘‘ of oxidation of iron in tungsten and 
used: for Jomitiona-se 55 = eae —125° 
10602° 
Mor pram. of  tumestenca ae) sae ae 1267° 


The average is 1260° for 1 gram’ and 231200° for 184 grams. 
For the heat effect of Na,O + WO, we have 


3Na,0, +. W = Na, WO, + 2Na,0 - 22> 2eneoue 
aiNa O30 ==) BINa OF ole aoe PANS Ao 58200° 
Na OTE eW + 130, ="Nas WON. oun 291000° 
We Og =! WO) eee eee 196300% 
Nao Seay = Na WO se) eee eee 94700° 


* Delépine et Hallopeau, C. R., cxxix, 600. 


Mixter—Heat of Combination of Acidic Oxides. 187 


Summary. 
eNO i Oe INA Oe SS LL O4200° 
Na,O + AI,O,(amorphous) = 2NaAlO, + --- ~40000° 
Na,O + AI,O,(crystalline) = 2NaAlO, + ---  30000° 
Al,O,(amorphous) = AI,O,(crystalline) + --  10000° 
er Or Gy Na OrOrer oil sacee Pasi s ie 77000° 
Mie ge = Ore ene s 228 TEOOUCS 
2Cr + 30 = Cr,O,(amorphous) + ~-.-.----- 243800° 
ere oO) = Cr O- (crystalline) - 2 -...-2.5 _267800° 
Gr_O, (crystalline) + 30 = 2CrO, +. ------- 12200° 
€rO-(amorphous) +: 30 = 2CrO, + °.-:---- 36200° 
mom NWO. = Nap W Oi) ees ola 94700° 


The results given have been obtained with substances at 
hand and it is the intention to complete the work as far as 
possible on the fourth, fifth, and sixth groups. 


138 Phelps and Weed—Acids and Acid Anhydrides. 


Art. XVI.—Concerning Certain Organic Acids and Acid 
Anhydrides as Standards in Alkalimetry and Acidimetry ; 
by I. K. Paetes and L. H. Weep. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxix. ] 


In a former paper* from this laboratory it has been shown 
that, with cochineal as an indicator, succinic acid may be used 
as a standard fora decinormal ammonium hydroxide solution 


quite as accurately as may a decinormal solution of hydro-— 


chlorie acid, the standard of which is determined gravimetri- 
cally as the silver chloride. In this paper results are given 
which show that, in presence of phenolphthalein as an indica- 
tor, pure sodium hydroxide in solution and also pure barium 
hydroxide in solution may be determined similarly with suc- 
cinic acid, succinic anhydride, malonic acid, benzoic acid, 
phthalic acid and phthalic anhydride, as standards. And, 
further, it isshown that these organic acids and acid anhydrides 
react with these alkaline solutions so that each may be used as 
a standard in acidimetry and alkalimetry with the same exact- 
ness that is found when these alkaline solutions are titrated 
in the well established manner with decinormal hydrochloric 
acid, standardized gravimetrically as silver chloride. 

For the work given here a solution of hydrochloric acid 
was made up approximately decinormal by diluting the chem- 
ically pure acid of commerce in the usual manner. The 
exact strength of the hydrochloric acid solution was deter- 


mined by precipitating definite amounts of it in a platinum 


dish, in some cases, and in a glass beaker, in others, by an 
excess of silver nitrate, in presence of a few drops of dilute 
nitric acid. In each case the precipitate of silver chloride 
was allowed to stand for twenty-four hours before filtering on 
a weighed asbestos felt in a perforated platinum crucible. 
The volume in which the silver chloride was precipitated was 
such that after the precipitation was made it amounted to about 
250 cubic centimeters. 

The sodium hydroxide solution was made up to correspond 
approximately to the hydrochloric acid solution, by diluting 
with distilled water, freshly boiled, pure sodium hydroxide, 
prepared by the action of water vapor on metallic sodium 
according to the, method of Kister.+ The barium hydroxide 
was prepared pure by crystallizing twice commercial barium 
hydroxide out of hot water, washing the crystals after each 
purification with alcohol. A solution, approximately decinor- 
mal, was made by dissolving these erystals i in a suitable amount 


*~ This Journal, xxii, 201, 
+ Zeitschr. anorg. Chem., xli, 474. 


Phelps and Weed—Acids and Acid Anhydrides. 139 


of water and filtering into a closed bottle before diluting with 
freshly boiled distilled water. Both the sodium hydroxide 
solution and the barium hydroxide solution were kept in closed 
bottles, each connected with a three-way-stoppered: burette in 
the usual manner. ‘These solutions were protected from the 
action of carbon dioxide in the air by soda-lime tubes. 

In all the experiments recorded in the tables given below, 
definite portions of the organic acids and acid anhydrides, in 
most cases, were treated with distilled water and the solution 
of sodium hydroxide or barium hydroxide was introduced into 
these solutions by carefully drawing from the burette until the 
appearance of color in the solution, due to the presence of 
phenolphthalein as indicator, showed the reaction to be com- 
plete. In a few cases, the treatment was special, as is 
described. 

Pure succinic acid was obtained by boiling succinic ester, 
whose purity was established by the fact that it distilled within 
one-fifth of a degree, on a return condenser for four hours 
with water containing a few drops of nitric acid. This solu- 
tion was evaporated to crystallization and the solid product, 


TABLE I. 


HCl HCl 

value of value of Theory in Error 

Sueciniec Succinic NaOH  BaO.H, terms in terms 

No. acid anhydride used used. of HCl of HCl 

erm. erm. erm, erm, erm. erm. 
ie 0°2000 fai 0°1236 ee Ae 0°1235 ‘0001 + 
II 0:-2000 evi; 0°1238 Saye 0°1235 "00038 + 
III 0-2000 SEES Onk2 37 Eo Ree 0°1235 "0002 + 
IV 02000 Sane fs 0°1236 eden. 0°1235 ‘0001 + 
V_ 0:2000 Bers 0°1236 Pen. 0°1235 ‘0001 + 
VI 0:2000 ee en 0°1237 lores 0°1235 "0002 + 
VII 0:2000 ee ete 0°1237 Sees 0°1235 ‘0002 + 
VIII 0-2000 a ace 071237 Seca 0°1235 "0002 + 
IX 0:2000 Sess OES 7 Lp Ter 0°1235 0002 + 
X 0°2000 5 ae 0°1237 sees 0°1235 ‘0002 + 
XI 0°2000 Cee bgS ier. 0°1238 0°1235 0003 + 
XII 0-2000 aA ees 0°1237 0°1235 ‘0002+ 
XIII 60-2000 Eres pee PAO We 071235 ‘0000+ 
XIV 0:2000 en Edith 0°1236 0°1235 0001+ 
XV 22 TE OFZ000 0°1458 aoe nid 0°1458 ‘0000+ 
Bel jt E2000 0°1458 eee 071458 -0000+ 
XVII zee OcOUD 0°1459 rake 0°1458 ‘0001 + 
XVIII 2 C2000 0°1458 ae 0°1458 ‘0000+ 
XIX ta ns eo OOOO Ba Oo 1457 0°1458 ‘0001— 
BA ae, 622000 uid 3 0°1456 0°1458 ‘0002 — 
XXI 222 + 02000 fy hiaee 0°1459 0°1458 ‘O001 + 
XXII eee OF Z2000 ea 0°1458 0°1458 ‘0000+ 


140 Phelps and Weed—Acids and Acid Anhydrides. 


after the removal of the mother liquor by filtering, was 
recrystallized from distilled water. _ After these crystals had 
dried in the open air to constant weight, it was found that on 
standing over sulphuric acid in a desiccator the weight remained 
unchanged. For the preparation of succinic anhydride, com- 
Peroni succinic acid was treated with an excess of acetyl 
chloride and heated on a water bath with a return condenser 
at 60°, as long as bubbles of gaseous hydrochloric acid were 
evolved from the hquid. The material, which separated out 
on cooling, was recrystallized from ethyl acetate. These erys- 
tals of succinic anhydride were then washed with absolute 
alcohol and were dried to constant weight over sulphuric acid 
in a desiccator. 

The succinic acid used in experiments VI, VII, and VIII of 
Table I had been dried for more than a year in a desiccator 
containing sulphuric acid, while that used in experiments IX 
and X of the same table had been dried for the same length 
of time over calcium chloride in a desiccator. It is evident 
from these experiments that succinic acid dried in desiccators 
over sulphuric acid or calcium chloride for long periods of 
time is unaffected. 

Owing to the considerable length of time that is taken by 
succinic anhydride to dissolve in water even in the presence of 
some alkali, experiments XX and XXII of Table I were 
slightly modified. In these the solution was heated until the 
anhydride completely dissolved before any of the alkaline 
hydroxide was added. 

Malonic acid was prepared pure by heating for some hone 
between 50° and 60° on a return condenser malonie ester, 
which boiled between limits of two-tenths of a degree, with 
water in the presence of a few drops of nitric acid. The vol- 
ume was then concentrated, keeping the temperature of the 
solution below 60° until crystallization began, the erystals 


ApNisriioh IB 

HCl value HCl value Theory Error 
Malonic of NaOH of BaO.H. in terms in terms 

No. acid used used of HCl of HCl 

germ. erm. erm. erm. erm. 
if 0°2000 0°1404 eee 0°1402 0002+ 
II 0°2000 0°1403 BY a 0°1402. ‘0001 + 
Ili 0°2000 0°1402 a. 0°1402 ‘0000+ 
lV 0°2000 0°1401 apt 0°1402 ‘0001— 
Vv 0°2000 igs 0°1401 0°1402 ‘0001— 
VI 0°2000 eee 01400 0°1402 "0002 -- 
Vil 0°2000 Ne 0°1402 0°1402 "0000+ 
VIII 0°2000 ieee 0°1400 0°1402 °0002— 


Phelps and Weed—Acids and Acid Anhydrides. 141 


filtered off and recrystallized out of boiling water. The pure 
malonic acid was then allowed to come to constant weight 
over sulphuric acid in a desiccator. 

To obtain pure benzoic acid, benzoic ester was treated with 
sodium hydroxide in excess, and acidified with hydrochloric 
acid. The benzoic acid thus precipitated was crystallized twice 
from water and dried to constant weight ina desiccator over 
sulphuric acid. 


TaBLe ITI. 

HClvalue HCl value Theory Error 
Benzoic of NaOH of BaO.H. in terms in terms 
No. acid used used of HEI of HCl 

germ. eTm. erm. erm. gTm. 
1 0°2000 0°0598 ae 0°0597 ‘OOO01 + 
II 0°2000 0°0599 she 0:0597 0002+ 
Ill 0°2000 0:0597 nll 0°0597 “0000+ 
IV 0°2000 0°0598 ss a 0°0597 “0001+ 
Vv. 0°2000 Bee Mate 0°0598 0°0597 ‘OOO1L + 
VI 0-2000 aes 0°0597 0°0597 70000 + 
VII 0°2000 rik & 0°0597 0°0597 ‘O000 + 
Vill 0°2000 es 0°0597 0°0597 ‘0000 + 


In all of the experiments in Table IT], alkali in amount nearly 
sufficient to neutralize the acid was run into the flask, which 
was then heated. This aided materially in securing the solu- 
tion of the benzoic acid in the water and did not necessitate 
raising the solution to the boiling point. 


TaBLeE IV. 

1 HCl Theory Error 
Phthalic valueof value of in terms in terms 

Phthalic anhy- NaOH BaO.He of of 

No. acid dride used used HCl HCl 

erm. erm. erm. erm. erm. erm. 
I 0°2000 See 0-0880 pies to 0°0878 0002 + 
II 0°2000 eet 0-'0880 ie ar 0:0878 "0002 + 
Il 0°2000 at 1050879 Sie 00878 -0001+ 
IV 0°2000 te OSES Bers 0°0878 ‘0000+ 
ee 02000 Clete. Paar 00876 00878 -:0002— 
VI 0°2000 ees apes 0-O877 0:0878 ‘0001— 
Vil 0°2000 seeoed Nd seat 0:0878 0'0878 “0000+ 
Vill 0°2000 bee! nears 00879 0‘0878 “OOO01 + 
PX. ae 0°2000 0°0986 ee 0'0985 “0001 + 
xX ee 0°2000 0°0985 wits 0°0985 0000 + 
XI Tere 0°2000 0°0986 ERY ip 0°0985 0001 + 
XII L068 0°2000 00987 Paes 0°0985 "0002 + 
XIII wna 0°2000 eee 0:0986 070985 ‘0001+ 
XIV wae 0°2000 ise 00985 0°0985 ‘0000+ 
XV AR, 0°2000 eo 0°0986 0°0985 ‘0001+ 
a ree 0°2000 2 aa 0'0987 00985 ‘0002 + 


142 Phelps and Weed—Acids and Acid Anhydrides. 


Phthalic acid was prepared by boiling in distilled water some 
commercial phthalic anhydride. The solution was filtered 
while still hot; the crystalline product obtained on cooling 
was separated by filtration, air-dried, and finally dried to con- 
stant weight in a desiccator over sulphuric acid. The phthalic 
anhy dride was prepared in a state of purity by distilling 7 
vacuo the phthalic anhydride of commerce. The product ob- 
tained was dried to constant weight in a desiccator containing | 
sulphurie acid. 

In Table IV, experiments II and VIII alone were carried 
on at ordinary temperatures. In the other experiments in this 
table the titrations were all performed after heating the solu- 
tion until the phthalic acid or the phthalic anhydride used had 
entirely dissolved. 

It is evident from the results recorded in the four tables 
that succinic acid, suecmic anhydride, malonic acid, benzoic 
acid, phthalic acid and phthalic anhydride may be used with 
great exactness as standards for decinormal solutions of 
sodium hydroxide and of barium hydroxide. As a standard 
for a solution of barium hydroxide, these organic¢ acids and 
acid anhydrides are even more accurate in our experience than 
the determination of the barium hydroxide solution grayi- 
metrically asthe barium sulphate. In the various tables are 
given results which show the accuracy with which barium 
hydroxide may be standardized by the different organic sub- 
stances when compared with the standard of decinormal hydro- 
chloric acid established as the silver chloride. This same solu- 
tion of the barium hydroxide which gave a value of 0-006396 
orm. per cubic centimeter in terms of hydrochloric acid when 
standardized against the organic acids and acid anhydrides, gave 
avalue of 0:006430 grm. per cubic centimeter in terms of 
hydrochlorie acid when standardized by precipitating and 
weighing as the barium sulphate, by the usual procedure for 
the determination of barium. 

As standards in alkalimetry and acidimetry, these organic 
acids and acid anhydrides, in pure state, are equally as accurate 
as the best previous standard—hydrochloric acid determined — 
gravimetrically as the silver chloride. The most serviceable of 
these organic substances tested are those most readily soluble 
in water—succinic and malonic acids—although they are no 
more accurate than the other organic acids and acid anhydrides, 
as is shown by the results given in the tables. Since these 
substances can be readily prepared in a known state of great 
purity, their serviceability as most accurate standards 1s 
evident. 


a. 
> a 


Phelps and Weed—Succinie Acid. 143 


Art. XVII.—A Comparison between Succinic Acid, Arsen- 
ious Oxide, and Silver Chloride as Standards in Lodimetry °Y, 
Acidimetry, and Alkalimetry; by I. K. Puerps and L. H. 
WEED. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxx.] 


Tue use of an excess of a mixture of an iodide and an iodate 
has been suggested by several as a most exact and convenient 
method for determining quantitatively various acids in alka- 
limetry and acidimetry. Kyjeldahl* suggested the use of these 
reagents for determining nitrogen as ammonia in organic 
substances. Later Furry+ showed that the conditions of con- 
centration affected the end-point of this reaction. In very 
dilute solutions there was an after-coloration which be showed 
to be due to the incomplete action of the mineral acid rather 
than to the action of carbonic acid in solution. Grédgert 
showed the applicability in alkalimetry and acidimetry of the 
lodide-iodate mixture for determining decinormal solutions of 
acids and of alkaline hydroxides, carbonates, and sulphides. 
In the ease of the acids, he treated directly with an excess of the 
neutral iodide-iodate mixture and measured the iodine set free 
by titration, in presence of starch as an indicator, with sodium 
thiosulphate, standardized either against a weighed amount of 
free iodine or against the iodine set free by the action of an 
excess of hydrochloric acid and of iodate-free potassium iodide 
upon a weighed amount of pure potassium iodate in solution. 
In the case of the alkaline hydroxides, carbonates, and sul- 
phides, the solutions were treated with an excess of standard 
mineral acid and then this excess was determined in the man- 
ner described above. The comparison was shown between the 
results so obtained and those given by direct titration of the 
solution of the alkalies against decinormal sulphuric acid, in 
presence of litmus and of phenolphthalein as indicators, and, 
for the acids, by similar titration with a decinormal potassium 
hydroxide solution. The agreement was good except in the 
case of the carbonates where the iodometric results are low, 
even when the solutions were allowed to stand for thirty 
minutes before completing the titration. In a later paperS 
Groéger suggested pure potassium iodate as a standard in 1odi- 
metry y, acidimetry, and alkalimetry. The results are good 
but the difficulty in using the process for practical work is not 
only the necessity of obtaining pure potassium iodate but also 
the necessity of using potassium iodide free from iodate. 

* Zeitschr. analyt. Chem., xxii, 366. 
+ Amer. Chem. Jour., vi, 341. 


¢ Zeitschr. angw. Chem., 1890, 355. 
$ Zeitschr, angw. Chem., 1890, 385. 


144 Phelps and Weed—Suceinie Acid. 


The practical difheulty usually found in the use of arsenious 
oxide as a standard in iodimetry lies, in out experience, in the 
fact that in most cases the purest resublimed arsenious oxide 
does not always give a clear solution when treated with an 
alkaline hy droxide or bicarbonate. To whatever cause this 
insoluble residue may be due—to a slight action of the alkaline 
solution upon the glass or to some impurity in the alkaline 
hydroxide or bicarbonate used—it is in itself sufficient to make 
desirable, for accurate work, the possibility of checking results 
obtained with arsenious oxide as a standard. 

It has been shown in former papers* from this laboratory 
that succinic acid may be used, in presence of cochineal as an 
indicator, as a standard for the exact determination of a deei- 
normal solution of ammonium hydroxide, and, also,. that 
succinic, malonic, benzoic, and phthalic acids, as well as the 
anhydrides of succinic and phthalic acids, may also be used, 
with phenolpthalein as an indicator, as standards for decinor- 
mal solutions of sodium hydroxide and of barium hydroxide. 
The results, which are given below, show that succinic acid 
may also be used ag the standard for work in iodimetry, alka- 
limetry, and acidimetry, with exactly as much accuracy as the 
best previous standards for this work—titration against a 
decinormal solution of pure arsenious oxide or the gravimetric 
determination of a solution of hydrochloric acid as silver 
chloride. 

For this work, solutions of hydrochloric acid and of sul- 
phuric acid were made up approximately decinormal by 
diluting in the usual way the chemically pure acids of com- 
merce. The exact strength of the hydrochloric acid solution 
was determined by precipitating definite amounts of the solu- 
tion of hydrochloric acid, in some cases, in a platinum dish 
and, in other cases, in a olass beaker as silver chloride by an 
excess of silver nitrate in the presence of a few drops of dilute 
nitric acid, filtering off on asbestos under pressure in a per- 
forated platinum crucible the precipitate of silver chloride 
after allowing the whole to stand in the dark twenty-four 
hours. The solution of sodium hydroxide was prepared by 
diluting pure sodium hydroxide, prepared by the method. 
given by Kiister,+ with distilled water, freshly boiled. The 
solution of sodium hydroxide was kept in a closed bottle, 
connected in the usual manner with a three-way- stoppered 
burette. It was protected from the action of carbon dioxide 
in the air by soda lime tubes. The exact strength of this 
approximately decinormal solution was determined by titration 
against the standard solution of hydrochloric acid, approxi- 


* This Journal, xxiii, 211; xxvi, 138. 
+ Zeitschr. anorg. Chem. xli, 474. 


Phelps and Weed—Succinic Acid. 145 


mately decinormal, and against pure succinic acid, in the 
manner described in the. paper to which reference has been 
made. The exact standard of the decinormal solution of sul- 
phuric acid was determined by titration against the decinormal 
sodium hydroxide solution, in presence of phenolphthalein as 
indicator. . 

The decinormal solution of arsenious oxide was carefully made 
up by treating £9500 grams of the purest arsenious oxide of 
commerce, twice sublimed, in a beaker in fifty cubic centi- 
meters of distilled water with fifty eubic centimeters of a 
solution containing about twelve grams of sodium hydroxide, 
prepared pure according to the method of Kiister.* After the 
arsenious oxide had been dissolved by gentle warming, the 
solution was transferred to a standardized liter flask, by using 
enough distilled water in this transference to make the volume 
approximately 250 cubic centimeters. This was then satu- 
rated with purified carbon dioxide and diluted to a liter under 
proper conditions of temperature. The solution of iodine was 
made up approximately decinormal by dissolving iodine in an 
aqueous solution of potassium iodide, the exact strength of the 
solution being determined by titration against the standard 
solution of decinormal arsenious oxide, in presence of an excess 
of sodium bicarbonate, with starch solution made in the usual 
way as the indicator. The solution of sodium thiosulphate’ 
was made up approximately decinormal by dissolving in dis- 
tilled water the pure sodium thiosulphate of commerce. The 
exact strength of this solution was determined by titrating 
definite portions of it against the iodine solution, using the 
starch solution as indicator. 

In this work, potassium iodide and potassium iodate were 
first put into solution in such amounts as to be in excess at the 
end of the reaction. Definite portions of the decinormal 
hydrochloric acid solution were then run in from a burette, 
setting free the iodine. The solution of sodium thiosulphate 
was next added in amount slightly in excess, and this excess 
was determined either by adding more of the hydrochloric 
acid solution or by the addition of the iodine solution, until 
the blue color of the starch indicator showed the reaction to be 
complete. In all of the experiments recorded in Table I, one 
gram of potassium iodide was used and fifty cubic centimeters 
of asolution of potassium iodate, prepared by dissolving 3°3400 
grams of the iodate in a liter of distilled water. Presumably 
on account of the presence of acid potassium iodate in the 
sample of iodate used, the addition of the potassium iodate 
solution to the potassium iodide set free a slight amount of 
iodine. ‘This free iodine was removed either by boiling until 


* Loe: cit. 


146 Phelps and Weed—Succinie Acid. 


the characteristic color of free 1odine disappeared, or by add- 
ing portions of a dilute sodium thiosulphate solution until the 
blue color of the starch solution introduced was bleached. In 
all of the experiments in this table, also, five cubic centimeters 
of a potato starch solution were added before the titration 
was begun. 


TABLE I. 
HCl value of - 
HCl Na2S203 Iodine 
solution solution solution HCl Error in 
used used used found HCl 
No. erm. erm. erm. erm. erm. 
( 1) O'1074 0:1075 ad a 0°1075 0°0001 + 
( 2) 0°1074 0°1074 deta 0°1074 0:0000 + 
( 3) 0°1074 0°1075 Sy ee 0O°'1075 0°O0001 + 
( 4) 0°0520 0°0520 ie ee 0:0520 0°0000 + 
( 5) 0°1560 0°1562 ee 0°1562 . 0°0002 + 
( 6) 0°0645 0-07 12 0°0068 0°0644 0:0001 — 
( 7) 0°0968 0°'1068 0°0101 0°0967 0:0001— 
( 8) 0°0645 OrO7a2 0°0067 0°0645 0:0000 + 
( 9) 0:0968 0°1068 O:0101 0°0967 0:0001 — 
(10) 0°0484 0°0534 0°0050 0°0484 0:0000 + 
(ars) 0°0645 0:0748. — 0:0104 0°0644 0:0001— 
(12) 0:0484 0°0534 0°0050 0:0484 0'0000+ 
(13) 0°0645 0'0712 0°0066 0'0646 0'0001 + 


In experiments (1) to (5) inclusive of Table I the excess of 
the sodium thiosulphate was determined by the addition of 
decinormal hydrochloric acid to color with starch, while in 
the other experiments the excess was determined similarly by 
titration against the decinormal iodine solution. In experi- 
ments (1) to (7) inclusive, the iodine set free on the addition 
of the potassium iodate to the potassinm iodide was removed 
by boilmg as described above. In experiments (8) to (13) 
inclusive of the same table, the iodine set free was removed 
by dilute sodium thiosulphate, which was added until the color 
of the starch solution present was bleached. 

The solution of hydrochloric acid used to set free the iodine 
was standardized as silver chloride as well as against a deci- 
normal sodium hydroxide solution, the exact strength of which 
was established by titrating with the organic substances as 
standards, as we have shown ina former paper.* It was shown 
also in that paper that the standards obtained by silver chloride 
and the organic substances are in agreement within the limits of 
experimental error. From an inspection of Table I, in which 
the action of a decinormal solution of hydrochloric acid, stand- 


*This Journal, xxvi, 138. 


Phelps and Weed—Suceinie Acid. | 147 


ardized as the silver chloride, as well as the organic substances 
mentioned above, is brought into comparison with decinormal 
solutions of sodium thiosulphate and iodine, standardized 
against a carefully prepared solution of arsenious oxide, it is 
evident that the two standards, silver chloride and the organic 
substances, are in agreement ‘with the third standard, a deci- 
normal arsenite solution made up with the precautions given 
above. 

Further, it is evident that the incompleteness of the action 
of mineral acid on a mixture of iodide and iodate in dilute 
solution, as shown by Furry,*. does not take place appreciably 
under the conditions used here with decinormal solutions. 
This is particularly striking in view of the different procedures 
used in the experiments recorded. When, however, the action 
of centinorma] solutions of iodine, thiosulphate, and hydro- 
ehloriec acid was tested with the iodide-iodate mixture, the 
phenomena observed by Furry became very apparent, compara- 
tively wide variations in the results being obtained. 

That this method of standardization in alkalimetry could 
also be used in the presence of carbonates is shown in Table 
Il. In the experiments included in that table, definite portions 
of the decinormal solution of sodium hydroxide were first 
drawn from the burette. Purified carbon dioxide was then 
passed into this solution for different lengths of time, convert- 
ing the sodium hydroxide to the carbonate or bicarbonate. 
The solution of sulphuric acid was then added in excess, and 
the carbon dioxide set free was completely driven out of the 
solution by boiling in a flask, trapped with the bulb-end of an 
ordinary calcium chloride tube, to prevent mechanical loss, the 
boiling being continued until the volume was reduced one- 
third. After cooling, the excess of acid was estimated in two 
ways. In experiments (1) to (4) inclusive, the excess of acid 
was determined by direct titration, in presence of phenolph- 
thalein as an indicator, with the decinormal solution of sodium 
hydroxide. The second method of determining the excess of 
the sulphuric acid was used in experiments (5) to (8) inclusive. 
To these, after cooling, a solution, containing one gram of 
potassium iodide and fifty cubic centimeters of the solution of 
potassium iodate described above, was added, after the free 
iodine had been removed from this iodide-iodate solution by 
the addition of a dilute sodium thiosulphate solution in the 
presence of starch as an indicator. Definite, portions of the 
decinormal sodium thiosulphate solution were then added in 
excess, and this excess was determined by titration with the 
decinormal iodine solution. 


* Loe. cit, 


148 Phelps and Weed—Succinic Acid. 
TaBLeE II. 
HCl value of 
a PRET Pan eat kota y aan 
Treat- Differ- 
ment NaOH HeSO. NaOH Na.S.O03; #Iodine ence _ 
with solution solution solution to solution solution to in terms 
No. CO, used used coloration used coloration of HCl 
min, erm. erm, erm. erm. grm. grm. 
GL) ale O Ou VOW 306". 020293. ae eee eee 0°0001 + 
(2) 30 O1012) O-1219 0°0205 2 ae Lae ale eae 0'0002 + 
(8) OM BAO: OPL D245 OO dni? oo coc aed che eae 0°00038 + 
(4) 30  0°1349 0°1568 O021:6.4-3) a eee ee 0°0008 +- 
(5) 15 ODOT. OMS O Oe wae serene. 0°0302 0°0013 0°0005 + 
(OO) a0 OTOH, a OR EKOG se sc = 0°0502 0°0013 0:0005 + 
C7) sets 0°1349 0°1742 se Ales) es 0.03892 0°0004 0°0005+ 
(8) 35 OF 3499 OAc see ae 0°0552 = 0°0162 0°0003+ 


The differences recorded in the last column of Table IT 
show that the standard of the sulphurie acid is slightly higher 
than the summation of the sodium hydroxide originally taken, 
and of the sodium hydroxide or thiosulphate and iodine used 
to determine the excess of sulphuric acid. From these results © 
it seems to appear that the differences are presumably to be 
attributed to two causes—the experimental error and, perhaps, 
a slight mechanical loss of sulphuric acid during the long 
boiling. 

These results show that a non-volatile acid like sulphurie 
acid may be used with exactness to determine alkaline carbon- 
ates in either of the two ways described. _ The essential thing 
in the exact titration with a solution of sodium hydroxide, 
with phenolphthalein as an indicator, as is well known,* is the 
absence of carbonate, as is also the case in the use of the 
potassium iodide- iodate mixture.t . This condition is easily 
attained by boiling, as was done in these experiments. 

From these results , it may be seen that the standards of the 
solutions used in work in iodimetr y, alkalimetry, and acidime- 
try may be found as exactly by titrating against certain pure 
organic acids as standards, as against the best known standards 
usually used in such work—the decinormal solution of arsen- 
ious oxide, or a decinormal solution of hydrochloric acid, 
standardized gravimetrically as silver chloride. Succinie acid 
was used as the organic acid standard in this work because of 
the ease with which it is prepared in a state of purity and its 
ready solubility in water, but it is clear from work shown in 
an earlier paper} from this laboratory that malonic, benzoic, 
and phthalic acids as well as the anhydrides of succinic and 
phthalic acids, could be used with equal exactness. 

* Kuster, Zeitschr. anorg. Chem., xiii, 127. 


+ Groger, Zeitschr. angw. Chem., 1890, 358. 
t This Journal, xxvi, 138. 


_ 


Ford and Tillotsan—Orthoclase Twins. 149 


Art. XVII.—On Orthoclase Twins of Unusual Habit; by 
W. EE. Forp and E. W. Trtvortson, JR. 


Tue orthoclase twins to be described in the following pages 
were collected by Prof. L. V. Pirsson during the summer of 
1896, while engaged in work for the United States Geological 
Survey in Montana. They occurred as phenocrysts in an altered 
tineuaite porphyry which lay as an intruded sheet between 
black shales near the head of West Armell Creek in the Judith 
Mountains. The tinguaite sheet is described* as measuring 
“between ten or twelve feet in thickness with numerous 
immense feldspar phenoer. ysts, some of them being four by two 
by one inches across.” The groundmass of the rock is fine- 
grained with a greenish gray color, the green tone being due to 
the presence of tine crystals of sevirite, while on the weathered 
surfaces it is spotted with numerous pits stained yellow with 
iron oxide. The writers desire to express to Prof. Pirsson 
their thanks for the opportunity to figure and describe these 
crystals. 

The phenocrysts occur as well- developed crystals and, as has 
been said, are at times of considerable size. They are opaque 
and are frequently stained on the surface with iron oxide or 
colored green with a thin coating of egirite. When broken, 
however, they present a glassy ‘luster and fresh appearance. 
The crystal faces were too rough to admit of measurements 
other than those with the contact goniometer, but the forms 
present were easily identified in this way and by their zonal 
relations. They were all common forms comprising } (010), 
c (001), m (110), 2(150), 2 (021) and o (111). <A few erystalsin the 
suite were untwinned and possessed a development as repre- 
sented in figure 1, but for the most part the phenocrysts were 
twinned according to the Baveno law in which n (021) be- 
comes the twinning plane. They differ markedly in habit, how- 
ever, from the common form of Baveno twins in that instead 
of having the composition plane symmetrically placed in diag- 
onal position through the square prism-like crystals, they are 
rather in the nature of contact twins having the two individuals 
more or less completely developed and grown together at right 
angles to each other without much interpenetration. Figures 
2 and 3 illustrate this peculiarity of development. In these 
cases the division between the two individuals can be distinctly 
traced, and is practically a single plane. In the erystal illus- 
trated in figure 2, the individual drawn in normal position is 
quite completely and symmetrically developed and the smaller 


* Weed and Pirsson, U.S. G. S., Ann. Rep., 1896-7, iii, 524. 


Am. Jour. Scil.—FourtH Series, VoL. XXVI, No. 152.—Aveust, 1908. 
1a 


150 Ford and Tillotson—Orthoclase Twins. 


one, not so completely formed, is merely grown on to the side 
of the larger. The bottom plane of this twin is made up of the 
c (O01) face of the first and the 0’ (010) face of the second individ- 
ual, the division between the two being clearly recognizable 
because in these crystals the clinopinacoid has always a somewhat 
brighter luster than the base. In this case the dividing line 


between the two faces is almost straight. In the erystal repre- 
sented in figure 3, the two individuals are more nearly equally 
developed, and here again the division between the two seems to 
be almost in the nature of a single plane. The composite face 
of this crystal is the one in back and to the left as the crystal 1s 
drawn and the distinction between the c and 6 faces is clearly 


Ford and Tillotson—Orthoclase Twins. 151 


defined, as the former is coated with a thin film of green egirite, 


. while the latter is clean. 


The erystal represented in figure 4, although in. general of 
the same type, differs in that the individual shown in normal 
position is apparently set into the other, the latter in a measure 
surrounding the former. In order to ascertain the relations 
existing between the two individnals of this twin, a section was 
eut through the crystal along a plane at right angles to the ¢ 
and 6 faces and close to the front of the erystal. Figure 5 
shows the relationship between the two individuals along this 
plane as indicated by the section, the shaded portion of the 
figure representing that part of the crystal placed in twin posi- 
tion. Where the dividing line was straight and clean cut, 
there was a slight crack to be observed between the two parts 
of the twin, but elsewhere there was considerable kaolinization 
of the feldspar and this line became more irregular and indis- 
tinct. 

The crystals were investigated both optically and chemieally, 
in order to ascertain if they showed in these respects any un- 
usual features which might be connected with their peculiar 
development. Sections were made parallel to the three pina- 
coids, a (100), 6 (010) and ¢ (001). They showed that the min- 
eral was slightly kaolinized, but not to any great extent. There 
was no evidence of microscopic twinning or of parallel growth 
of more than one feldspar. The optical orientation is that 
most common with orthoclase, the axial plane being perpendi- 
cular to 6 (010), a inclined to the a axis +4° 54’,and p >v. The 
conformity in its optical properties to normal orthoclase is 
rather surprising when the large amount of soda shown to 
be present by the analysis is considered. The results of the 
analysis by Tillotson follow: 


RJA 0 [aCe peo are ager 64°01 
I Ore see UNS 20°19 
RE): cnn Sogn OS eS 10°48 
iat OR Geese tate! ae 5°37 
Ao Gash inn erst 100°05 


This particular occurrence of the tinguaite rock was not ana- 
lyzed because of the alteration it had undergone through weath- 
ering, but a closely similar and fresh rock from Cone Butte was 
analyzed by Pirsson* and the percentage of the alkalies found 
by him agree closely with those of the present analysis. In 
the Cone Butte tinguaite, however, the soda was considered to 
belong entirely to either albite or nephelite, but in the West 


* This Journal, ii, 192, 1896. 


152 Ford and Tillotson—Orthoclase Twins. 


Armell.Creek occurrence, supposing that the two magmas were 
alike, it would all be accounted for by the orthoclase itself. 
In the present analysis the somewhat disproportionately low 
percentage of silica is probably due to the small amount of 
kaolinization which the feldspar showed in the thin sections. 

Drawing of the Crystals.—The erystals were drawn from 
a stereographic projection of their forms. ‘There was nothing 
new in the methods employed, but as concrete examples of the 


6 


use of the stereographic projection for the solution of such 
problems are seldom to be met with in the literature, a brief 
description of the manner of transposition of the poles of the 
faces from normal to twin position is here given.* According 
to the Baveno law of twinning the n (021) face becomes the 
twinning plane and as the angle c~n = 44° 56 1/2’ the angle 
between c and ¢' (twin position) becomes 89° 53’. For the 


* For a general discussion of the graphical use of the stereographic projec- 
tion, see Penfield, this Journal, xi, 1, 1901. 


Ford and Tillotson—Orthoclase Tivins. 153 


purposes of drawing it is quite accurate enough to assume that 
this angle is exactly 90° and that: accordingly the ¢ face of the 
twin will occupy a position parallel to that of the 6 face of 
the normal individual. 

Figure 6 shows the forms observed of the erystals both in 
normal and in twin positions, the faces in twin position being 
indicated by open circles and a prime mark (’) after their 
respective letters, while the zones in twin position are drawn in 
dashed lines. Star ting out with the forms in normal position, 
the first face to transpose is the base c. This form, from the 
law of the twinning, will be transposed to c’ where ‘it occupies 
the same position | as 6 of the normal individual, and it 
necessarily follows that 6 itself in being transposed will come 
to 6’ at.the point where the normal ¢ is located. 

In turning therefore the crystal to the leit from normal to 
twin position, the faces ¢ and 6 travel along the great circle 
I through an are of 90° until they reach their respective twin 
positions. We have, in other words, revolved the crystal 90° 
to the left about an axis which is parallel to the faces of the 
zone |. The pole of this axis is located on the stereographic 
projection at 90° from the great circle [and falls on the ~ 
straight line II, another great circle which intersects zone I 
at right angles. This pole P is readily located by the stereo- 
graphic protractor on the great circle II at 90° from c. The 
problem then is to revolve the poles of the faces from their 
normal positions about the point P to the vente and through an 
are of 90° in each case. 

During the revolution the poles of the 2 faces remain on 
the oreat cirele [ and as the angle nxn = 90°, the location of 
their poles when in tw in position is identical with that of the 
normal position and 7’ falls on top of m. We can now trans- 
pose the great circle I] from its normal to its twin position, 
since P remains stationary during the revolution and we have 
determined the twin position of ¢. The dashed are II’ gives 
the twin position of the great circle II. The twin position 
of y must lie on are II’ and can be readily located at y’, the 
intersection of are [I’ with a small circle about P having the 
radius Pay. It is now possible to construct the are of the 
zone II] in its tr ransposed position III’, for we have two of the 
points, y’ and n’ of the latter, already located. By the aid of 
the Penfield transparent oreat circle protractor the position 
of the arc of the great circle on which these two points lie can 
be determined. On this are, ILI’, 0’ and m’ must also lie. 
Their positions are most easily determined by drawing ares 
ot small circles about b’ with the required radii, bao = “63°8', 
bam = 59° 221/2' and the points at which they intersect are 
IIl’ locate the position of the poles 0’ and m’. At the same 


154. Ford and Tillotson—Orthoclase Twins. 


time the corresponding points on IV’ may be located, it being 
noted that IV’ and III are the same are. But one other form 
remains to be transposed, the prism z. We have already 0’ 
and mv’ located and it is a simple matter with the aid of the 
great circle protractor to determine the position of the great 
circle on which they he. Thenasmall circle about 6’ with the 
proper radius, bAz = 29° 24’, determines at once by its inter- 
sections with this arc the position of the poles of the 2 faces. 


The transposition of the faces from normal to twin position. 


having been made, it is a simple matter to draw the erystal 
figures from the projection.* It may be pointed out that if 
it should be desired to make use of the methods of the gnomonie 
projection for the drawing of the figures the stereographiec 
projection, as derived above, can be readily transformed into 
a gnomonic projection by doubling the angular distance from 
the center of the projection to each pole by the use of the 
stereographic protractor. But from whichever projection it is 
preferred to draw the figures, it is thought that the stereo- 
graphic projection, with the aid of the Penfield protractors, 
offers the simplest method for the ready transposition of the 
poles of the faces from normal into twin positions. 


Mineralogical Laboratory of the Sheffield Scientific School, 
Yale University, New Haven, Conn., April, 1908. 


* See Penfield, this Journal, xxi, 206, 1906. 


J. V. Lewis—Palisade Diabase of New Jersey. 155 


Art. XIX.—The Palisade Diabase of New Jersey; by J. 


VotnrEy Lewis.* 


THE intrusive trap that forms the Palisades of the Hudson 
extends, with outcrops several hundred feet thick, from west 
of Haverstraw, N. Y., southward to Staten Island and, some- 
what intermittently, westward across New Jersey to the Del- 
aware River, an aggregate length of about 100 miles.t It is 
everywhere a medium- to fine-grained dark gray heavy rock, 
with dense aphanitic contact facies. 

The typical coarser rock contains, in the order of abundance, 
augite, plagioclase feldspars, quartz, orthoclase, magnetite, and 
apatite. The first two occur in ophitic to equant granular tex- 
ture, and the next two in graphic intergrowths which some- 
time constitute one-third of the rock; in the contact facies 
this micropegmatite disappears and scattering crystals of olivine 
occur. 

A highly olivinie ledge, 10 to 20 feet thick and about 50 
feet from the base of the sill, is exposed in the outerops north- 
ward from Jersey City for about twenty miles. The olivine 
erystals, which constitute 15 to 20 per cent of this rock, occur 
as poikilitic inclusions in the augite and feldspar. 

Chemically the diabase ranges from less than 50 to more 
than 60 per cent of silica, with corresponding variation in 
alumina, ferric oxide, and the alkalis, while ferrous iron, lime, 
and magnesia vary inversely. ‘The augite is rich in these latter 
constituents and poor in alumina, giving a great preponder- 
ance of the hypersthene and diopside molecules. The feld- 
spars range from orthoclase and albite to basic labradorite. 
Doubtless there is some anorthoclase since all feldspar analyses 
show potash. 

While there is considerable range in the proportions of the 
minerals, augite usually comprises about 50 per cent of the 
rock, the feldspars about 40 per cent, quartz 5 per cent, and 
the ores 5 per cent, constituting a quartz-diabase, with normal 
and olivine-diabase facies. Basic concentration at the contacts, 
followed by differentiation by gravity during crystallization 
of the body of the sill, especially by the settling of olivine and 
the ores and the rising of the lighter feldspars in the earlier 
and more liquid stages of the magma, are hypotheses that seem 
to account for the facies observed and their present relations. 

Microscopic characters—In thin sections the texture of the 
rock is usually diabasic, or ophitic; that is, the augite fills the 

* Read before the New York Academy of Sciences April 6, 1908. Published 
by permission of the State Geologist of New Jersey. 

+J. Volney Lewis, Structure and Correlation of the Newark Trap Rocks of 
New Jersey, Bull. Geol. Soc. of America, vol. xviii, pp. 195-210; also 


Origin and Relations of the Newark Rocks, Ann. Rept. State Geologist of 
N. J. for 1906, pp. 97-129. 


156 J. V. Lewis— Palisade Diabase of New Jersey. 


interstices between the interlacing lath-shaped feldspars, or 
when greatly in excess 1t forms the groundmass in which the 
feldspars are imbedded. In the coarser-grained portions of 
the rock there is often developed a granitoid texture, in which 
the two chief minerals occur in grains of approximately equal 
size and of nearly equal dimensions in every direction. 

Augite, the most abundant constituent, is pale green to 
colorless and sometimes exhibits distinct pleochroism—pale 
green to hight yellow.* It occurs in plates up to 3 or 4 mill- 
meters in diameter, and in irregular grains whose forms are 
determined by the accompanying feldspars. Crystal outlines 
are rarely observed. In the denser contact facies augite of 
two generations appears, the earlier as large plates scattered 
through the denser groundmass in which the augite of later 
crystallization forms a fine granular filling between the feld- 
spars. Two forms of twinning often appear, both separately 
and in combination. That parallel to the or thopinacoid (100) 
usually produces paired halves, while the basal twinning (par- 
allel to 001) is more commonly repeated in thin lamellee, which 
are sometimes exceedingly minute. ! 

Plagioclase, the chief feldspar and the second constituent 
in abundance, occurs in characteristic lathlike forms, ranging 
up to 2 millimeters in length with a breadth one- fifth to one- 
third as great. In the coarse textures of the granitoid facies 
these dimensions become more nearly equal, and diameters of 
3 to 4 millimeters are often observed. Often the plagioclase 
presents complete crystal outlines, but very commonly the 
terminal planes are lacking, the elongated crystals abutting 
tee. against each other. They are made up of thin 
twinning lamellae, chietly according to the albite law, but peri- 
cline and Carlsbad twinning also occur. Zonal structure is 


ran) 
quite commonly developed, and fringing the extreme acid 


borders a graphic intererowth of quar tz and orthoelase is often 
found. 

Maximum extinction angles in sections normal to the 
albite twinning plane range a little under 30 degrees, corre- 
sponding to acid labradorite. Analyses of feldspars separated 
by heavy solution have shown that labradorite containing the 
soda and lime molecules in about equal proportions is the 
most abundant plagioclase; but other members of the series, 
present in considerable amount, range to almost pure albite. 

Orthoclase and quartz in oraphic intergrowth, as noted 
above, frequently form a fringe about the plagioclases, and 
fill many of the triangular and irregular interstices. These 

*TIn the examination of several hundred sections of Newark diabase from 
New Jersey and neighboring states only monoclinic pyroxenes have been 
observed. It seems highly probable that the hypersthene that has been 
occasionally reported in these rocks is simply pleochroic augite. 


J. V. Lewis— Palisade Diabase of New Jersey. 157 


areas are sometimes as much as 3 or 4 millimeters across, and 
are then distinctly visible in the hand specimen, as in the 
western portion of the Pennsylvania railroad tunnels at Home- 
stead. Frequently individual grains of quartz, and less com- 
monly of orthoclase, are also” observed, attaining in some 
instances a diameter of 1 millimeter. 

Magnetite is always present but in greatly varying amount. 
Orystals are sometimes observed, but most of it, like the augite, 
is irregularly clustered between the plagioclases, and some- 
times partly incloses both the plagioclase and the augite. The 
frequent presence of magnetite secondary from the alter- 
ation of augite renders it impossible in many cases to distin- 
euish with certainty that of primary origin. It is probable 
that masses molded about the other constituents are largely 
composed of secondary accretions. 

Biotite is also often present in small amount, and is usually 
clustered about the magnetite in relatively large irregular 
flakes. It is strongly pleochroic—deep reddish brown and 
light yellow. Some secondary biotite, after augite, occurs, 
but in most cases this is readily distinguished from the primary 
mineral. 

Olivine is absent from the great bulk of the rock. It occurs 
in small amounts, however, near the contacts with the inclos- 
ing strata, and is exceptionally abundant in the olivine-diabase 
ledge of the Palisades, constituting as much as one-fifth of the 
whole. In the fine-grained border facies of the rock it occurs 
in scattering por phyritic erystals, which sometimes exhibit 
resorption phenomena = rounded and embayed outlines. 
Corrosion mantles or “reaction rims” of radial enstatite 
occasionally surround the larger crystals, and nest-like aggre- 
gates of it entirely replace some of the smaller ones. In this 
part of the rock inass the olivine is usually more or less altered 
into yellowish or brownish serpentine ; but in the olivine-diabase 
ledge it occurs in numerous perfectly fresh crystals and irregu- 
lar grains. Most of it forms poikilitic inclusions in the feld- 
spars and less abundantly in the augites, and it retains a 
striking freshness and transparency even in the presence of 
considerable alteration of the augite. 

Apatite is always in well-formed prismatic crystals, ranging 
from very minute up to 1 millimeter in length and 0-06 milli- 
meter in diameter. Itis always abundant in the feldspars and 
quartz, sometimes im plagioclase, sometimes in the quartz- 
orthoclase intergrowth, and is rarely seen in the other consti- 
tuents. 

Chemical composition.—From a number of analyses that 
have been made the following are selected to show the range 
of composition of typical facies of the rock : 


158 J. ‘V. Lewis—Palisade Diabase of New Jersey. 


Analyses of Palisade Diabase. 


I I III IV 
SiO Ae aie 60-05 56°78 51°34 49-02 
ASO a One ais 8 14°33 POT 0s oom 
PeiO: £2 aise - 3-29 5°76 2°65 1°54 
HeO ek 10-21 9°27 14°14 10:46 
MeO stars 0°85 1°58 3°66 17°25 
CaQvse St 4°76 5°26 7-44 8-29 
Na Ogesee 5. 4-04 3°43 2°43 1°59 
KAO RSP Rel 1°75 1°44 0°40 
LO eae i 0°66 010 0-69 0°59 
POP ee ne! 0-21 0°33 0-18 0°16 
DiGi ee 1:74 1°44 3°47 0°99 
[Pes Otero aati 0°52 0°36 0°20 0-11 
NnQe irl O88 0°25 0°36 0°16 

100°52 100°64 100°71 100-70 


J. Pennslyvania R. Rh. tunnel, Homestead, 400 feet from the 
west end. : 
II. Old quarry near R. R. station, Rocky Hill, 420 feet from 

upper surface of the trap. 

Lil. Pennslyvania R. R. cut 420 feet east of Marion station 
(Tonnele Ave. ), Jersey City. 

IV. Englewood Cliffs, on the Palisades, 11 miles north of Jer- 
sey City. From the olivine diabase ledge. 

‘T, LI, and IV by R. B. Gage, chemist of the Geological Survey 
of New Jersey; II by A. H. Phillips of Princeton University 
(this Journal, vol. vii, 1899, Peco n): 

In general, alumina, ferric iron, and the alkalis vary with 
the silica, while ferrous iron, lime, and magnesia vary inversely. 
Chemically these rocks overlap the andesite-diorite series on 
the one hand and the most basic olivine-gabbros on the other, 
and the extremes are characterized by abundant quartz and 
olivine, respectively. 

- Classification. —In the older terminology the prominent 
facies of the Palisade sill would be known as quartz-diabase, 
diabase, and olivine-diabase, the prefixes quartz and olivine 
denoting special richness in these minerals. As indicated 
above, most of the coarse-grained rock, which constitutes by 
far the greater bulk of the Palisade sill from the Hudson to 
the Delaware, is decidedly quartzose, this mineral being quite 
generally pr esent in graphic intergrowth with orthoclase. In 
the most acid facies micr opegmatite constitutes about one-third 
of the bulk of the rock, but the average is probably somewhat 
less than one-tenth. On the other hand, the most basic facies 
contain 15 to 20 per cent of olivine, but this is confined to the 
relatively small mass of the pee diabase ledge. Normal 
diabase, without quartz or olivine, is much less abundant than. 


J. V. Lewis—Palisade Diabase of New Jersey. 159 


quartz-diabase, and this becomes slightly olivinie near the con- 
tacts. 

In the quantitative system of Messrs. Cross, Iddings, Pirs- 
son, and Washington the analyses given above would be clas- 
sified as follows: 


I. Class II. Dosalane 
Order 4. Quardofelic, Austrare 
Rang 2. Domalkalic, Dacase 
Subrang 4, Dosodic, Dacose 
II. Class II. Dosalane 
Order 4. Quardofelic, Austrare 
Rang 3. Alkalicalcic, Tonalase 
Subrang 4. Dosodic, Zonalose 
III. Class III. Salfemane 
Order 5. Perfelic, Gallare 
Rang 3. Alkalicalcic, Camptonase 
. . Subrang 4. Dosodic, Camptonose 
IV. Class 1V. Dofemane 
Order 1. Perpolic, Hungarare 
Section 2. Dopyric 
Rang i. Permirlic 
Section 2. Domiric 
Subrang 2. Domagnesic, Palisadose 


The great bulk of the rock, judging from about a dozen 
analyses and a large number of thin sections, appears to be of 
_the type represented by the third of the analyses given above, 
and might be termed a graphi-ophito- to graphi-grano-camp- 
tonose (III. 5. 3. 4). Notable amounts of the rock, however, 
belong to the more salic dacose (LI. 4. 2. 4) and tonalose (II. 
4, 3. 4) and to the more calcic auvergnose (III. 5. 4. 4, 5). 

The highly basic ferromagnesian olivine-diabase, of which 
the fourth analysis above is typical, is a sharply defined facies 
that may be designated as a povkili-ophito- to povkili-grano-pali- 
sadose. From the typical development of this rock along the 
Palisades northward from Jersey City it is proposed that the 
subrang into which it falls (LV. 1°. 1°. 2), hitherto unnamed, 
be designated as palisadose. 

The relations of these various facies to each other and the 
problem of their origin are discussed in the report on the 
petrography of the Newark igneous rocks of New Jersey.* It 
has already been remarked that the hypothesis of gravitational 
differentiation seems to account satisfactorily for all the condi- 
tions observed. 

Composition of the Augite.—Analyses of the augite from 
this sill at Rocky Hillt and from the very similar intrusive at 
West Rock, New Haven, Conn.,t yielded the following results : 

* Annual Report of the State Geologist of New Jersey for 1907.. 


+ A. H. Phillips, loc. cit. 
t G. H. Hawes, this Journal, vol.ix, p. 185, 1875. 


160 J. V. Lewis—Palisade Diabase of New Jersey. 


Analyses of Augite from the Palisade Diabase. 
r 


i. IIL. IV. 
SiO, Saas 7°72 48°54 50°71 47°10 
AlsO: eaieat 3°44 5°50) 3°55 4°55 
Hes@ (ae eee 5°98 COTE) n. d. de 
FeO. SS. 18°34 Dee? 5 15°30 15°20 
MeQ 8 = 12°89 7:67 13°63 18°65 
CaO ree. Re A’ = 1 TOr97 13:30 Tare 
IN 22 O pre ee 0°86 
oO Tz bs n. d. 
TOO aie Ors . 
NnOss ca ons n.d, 1G: 0:80 35 Ory 
Aarne fee eo 0-00 0°82 iy 1:38 
Fnsolpee ewes ae Ss pea deine 0°34 
100°95 100°62 100-00 98-67 


1 By difference. 

I. Rocky Hill, N. J. Quarry near the middle of the mp 
sheet. A HH. Phillips, analyst. 

Il. Rocky Hill, N. J. Old quarry near the railroad station, 
about 420 feet from the upper contact. A. H. Phillips, analyst. 

III. West Rock, New Haven, Conn. G. W. Hawes, analyst. 

IV. Aakeroe, Sweden. Partial analysis of diallage by H. von 
Post. * 

With the exception of smail deficiencies in silica in I, II, 
and IV, these analyses correspond to the following pyroxene 
molecules in the proportions indicated : 

Acmite, NaFe(Si0,), = ac. 

Hypersthene, (Me, Fe)SiO, ==. by. 

Diopside, Ca(Mg,Fe)(Si0, i == di. 

Aluminous molecule, (Me, Fe) (Al, Ke) SiO. = akaw 


ac. hy. di. alm. 

Pee T0822 BAO eT ONG. Kine a9 = 
Ley See OS een cal cea) ARR Y ieee 

Dee eb VLR. ee be Yisr. sia amen 
W270 : 330 : 784 Feemopt == 
D385 3 6°54 : Wore) = 1 = 

(pe 1S ey tel Naess, a 2 pprox.) 
16 Dara a) 522 : 956 Pear Oe = 
18S ss CR Dee FN B86": 1 =< 

2 Bors Lo Sa Ass epoxy 
IV. ?+t : 864 ; 808 5 oh a ae 
OPLOR oro Ole 1 = 

13 12 25 2 2 (ep prone 


These formulas indicate a quite exceptional composition for 
augite in the great excess ot ferrous iron and magnesia over 
lime, alumina, and ferric iron. 


* Dana’s System of Mineralogy, 6th ed., p. 360. 
+ Ferric iron and alkalis not determined. 


J. V. Lewis—Palisade Diabase of New Jersey. 161 


Composition of the Feldspars.—Feldspars were also separ- 
ated and analyzed from the Itecky Hill material by Phillips and 
from the West Rock locality by Hawes. Omitting non-feld- 
spathic constituents and assigning the potash to orthoclase, and 
the soda and lime to albite and anorthite, respectively, the 
analyses show the following constitution : 


Mineral Constitution of the Feldspars. 


iS Il. III. IV. VE VE | VI 4 ASE 


Sp. gr. >2°69 <2°69|>269 <2°69 <260 =2°57 7 >2°69 <2°69 
Re 


2° 
Steele <5 ee bare 12°6 ad ae} 3] | 6°0 Bw: 
Albite A7°1 Diss: f GOs6 £023 68°9 64°2 | 24°4 40°9 
maerghie 45°4 = 21-0 |26°2- 17"1 SH AV 69°6> 51-9 
ab,an, ab;an.z|absan, absan, abead, ab,;an, absans ab;ans 


I, if. Rocky Hill. Quarry near the middle of the trap sheet. 
Ill, 1V, V, VI. Rocky Hill, N. J. Old quarry near upper 
contact. 


VII, VOI. New Haven, Conn. West Rock. 


The plagioclase molecules as calculated range from nearly 
pure albite to labradorite. It is probable, however, that some 
of the soda is combined with the potash in orthoclase and 
anorthoclase. On the other hand. it is also quite possible that 
small amounts of more basic plagioclases would have been 
found if the beaviest portions had been further separated 
before analysis. The frequent occurrence of zonal structure 
in the plagioclases, however, seems to indicate that these 
minerals do not occur in individualized grains of uniform 
composition, but have been built up into composite crystals of 
successively more acidic and more sodic character. In the 
instances determined the portion with the highest specific 
gravity constituted more than half the total feldspar s, so that 
the labradorite molecule undoubtedly predominates. 

Metamorphic effects —Contact metamorphism has produced 
an elaborate series of hornfels, rocks characterized by various 
combinations of feldspar, biotite, quartz, augite, hornblende, 
tremolite, garnet, spinel, magnetite, muscovite, cordierite, 
scapolite, vesuvianite, sillimanite, andalusite, chlorite, calcite, 
analcite, titanite, tourmaline, zircon, apatite, and possibly leu- 
cite. The various types within the zone of metamorphism 
seem to vary with the original composition of the shales, and 
not to depend on relative distances from the contact nor degree 
of metamorphism. 

Metamorphic arkose, both in the inclusions and at, the con- 
tacts, contains besides the usual plagioclase, orthociase, and 
some quartz, also augite, biotite, epidote, cordierite, chlorite, 
calcite, tourmaline, and apatite. 


162. oS. *V. Lewis— Palisade Diabase of New Jersey. 


The contact metamorphie effects of the sill at Hoboken, New 
Jersey, have been described by Andreae and Osann,* who show 
that it is of exomorphic pneumatolytic character. To the four 
types of hornfels which they describe, J. D. Irving+ has added 
five others, and the present studies, in which no attempt has 
been made to present a complete series of alteration products, 
have brought out eight additional types of hornfels and four of 
metamorphic arkose. These might be extended almost indefi- 
nitely, since they do not occur as sharply defined types, but 
present various degrees of gradation from one to another. — 
Furthermore, they do not form zones or belts in any systematic 
order with relation to the intrusive rock, but alternate irregu- 
larly throughout all parts of the zone of metamorphism. It is 
evident, therefore, that the types observed are not the results 
of varying degrees of metamorphism, but are dependent only 
on original variations in the composition of the shales and sand- 
stones themselves. t 


* Andreae and Osann, Tiefen contacte an intrusiven Diabasen von New 
Jersey; Verh. d. Naturh. Med. Ver. zu Heidelberg. N. F. V., Bd. I, 1892. 

+ School of Mines Quarterly, vol. xx, pp. 213-225, 1899. 

{ For descriptions of these rocks, and of other igneous rocks besides the 
great intrusive sill, see ‘** Petrography of the Newark Igneous Rocks of New 
Jersey,” Ann. Report of the State Geologist of New Jersey for 1907, pp. | 
98-169. : 


F. B. Loomis—New Horse Srom the Lower Miocene. 1638 


Art. XX.—A New Horse from the Lower Miocene; by 
F. B. Loomis. 


Wettse the series of fossils, which show us the development 
and radial adaptations of the horse family, is already a large 
one, there still remain breaks and places where more material 
is desired. Such an unfilled gap exists between the rich Ohgo- 
eene Mesohippus fauna and the upper Miocene Protohippus 
group, just where the transition from the brachydont unce- 
mented teeth to the hypsodont cemented ones occurs. The 
finding by Peterson* of the excellent type of Parahippus 
nebraskensis in the Upper Harrison beds of Nebraska, closed 
in a part of this gap, and for two or three seasons fragments 


Fie. 1.—Crown views of the upper and lower dentition of the type of 
Parahippus tyleri. One-half natural size. 


have raised the expectation of a Lower Harrison horse. Dur- 
ng the season of 1907, under the guidance of Mr. Harold 
Cook, the Amherst ’96 expedition found a prospect, which 
proved to be the major part of the skull of this much desired 
type. While the brain case is wanting, a nearly perfect upper 
and lower dentition of an adult individual is preserved, show- 
ing an animal closely related to P. nebraskensis, but about 
a fourth smaller. The following specific description will point 
out the affinities and characters of the new species. 


Parahippus tyleri sp. nov. 


Type, a skull numbered 1079 in the Amherst College 
Museum, which while lacking the brain case preserves all the 
dentition except the upper canine and the first premolar of the 


* Ann, Carnegie Museum, vol. iv, p. 57, 1906. 


164 FB. Loomis—New Horse from the Lower Miocene. 


upper and lower jaw. The specimen was found in the upper 
part of the Lower Harrison beds, 8 miles northeast of Agate, 
Sioux Oo., Nebraska; and is named to honor Prof, J. M. Tyler, 
the organizer of the ‘Amherst expeditions. 

While having a rather short facial portion, the skull is 
moderately high and narrow. ‘The individual being described 
is an adult, only recently matured, as indicated by the moderate 
wear on the teeth and the fact that the third upper molar is 
scarcely worn at all. On the upper incisors the pit is deep, 
being entirely surrounded on the inner side by the raised cingu- 
lum. This pit seems to be more developed than in P. nebras- 
kensis. A canine is indicated by a small alveolus a short 
distance from the third incisor. The first premolar is wanting 
in this specimen. The second to the fourth premolars, while 
slightly larger, grade into the molars having the same charac- 
teristics. While the parastyle and the mesostyle are well devel- 
oped they are not as prominent as in P. nebraskensis. A 
remnant only of the cingulum is present on the inner part of 
the front border of each tooth. The protocone and protoconule 
unite to make a strong protoloph, but are separated from each 
other by a narrow constriction. On the metaloph of premolar 
four and the succeeding molars a small crochet is developed, 
which while distinct does not however unite with any part of 
the protoloph; consequently the prefossette is not en.irely 
isolated. The ‘hypostyle i is strong and notched in the rear. 

On the lower jaw the pit in the incisors is not as well devel- 
oped as in incisors of the upper jaw, appearing more like 
a groove behind a well-marked cingulum. The lower canine 
is a simple cone of moderate size. The first premolar is indi- 
cated by a smal] alveolus and must have been tiny. The 
remaining premolars and molars each have a well-marked 
cingulum, starting from the parastylid, continuing around the 
outer border, and back to a tiny hypostylid. The inner wall 
of each tooth is relatively straight, the upper part being, in 
little worn teeth, notched to separ ate off the strong parastylid, 
and again between the paraconid and hypoconid. “The heel of 
the third molar is moderate in size and simple in form. 

While very like, and probably ancestral to P. nebraskensis, 
this species is distinguished by the less pronounced parastyle 
and mesostyle, by the relatively narrower teeth, the deeper 
pit in the incisors, and the smaller size. It is a primitive 
member of the genus, the crochet not uniting with the proto- 
loph and cement being entirely absent. 


Geology. 165 


Measurements. 
Length of the upper incisor series._-....---- 28™™ 
Distance from incisor 3 to the canine.---_ .--- 11 
Length of the upper premolar series_.-__---- 59 
Heusen of upper premolar d2_.. --__._._.--- 20 
Witdil ef upper premolars .—-_-, =... .--+- 26 
Length of the upper molar series ----_-.---- 55 
Mele mher Uppee mort 2 9 2 ho 19 
Mbttnh of Upper molar 2.2) tk 26 
Length of the lower premolar series .--.-._-- 56 
Length of the lower molar series _.--..-.--- 59 
Mrden- eb lower molar foo fos Sos in 14 


Amherst College, Department Biology, 
May 29, 1908. 


SCIENTIFIC INTELLIGENCE. 


I. Grouoey. 


1. Indisches Perm. und die permische Hiszeit ; by E. Koxen. 
N. Jahrb. f. Min., Festband 1907, pp. 446-546, and a large paleo- 
geographic map.—This is a very important paper to all students 
of Permian and Triassic stratigraphy and to glaciologists. Noet- 
ling has in Koken a strong supporter for his Indian Permian 
stratigraphic correlations. The broader views of equivalency 
put forth some years ago by Tschernyschew are rejected. Koken 
‘holds that the Productus limestone of India passes without break 
into the Triassic, as it also does in the eastern Alps where the 
Bellerophon beds pass into the Werfen. Beneath the Productus 
limestone occur the Permian glacial deposits, the material having 
come from the south or peninsular India. Sands of glacial origin 
are also seen in the higher limestone and even in the T’riassic— 
the regolith of the southern lands carried by the rivers into 
Tethys. 

Various theories in regard to the probable causes for the 
Permian glaciation are discussed at length and Koken rejects the 
carbon dioxide theory of Arrhenius, and, as well, that of the wan- 
dering of the pole. He concludes that the probable cause is to 
be looked for rather in changed relations of the continents to 
equatorial waters, and therefore in the changed streaming of 
oceanic currents. During Permian glaciation India stood high 
and Australia was united to India and Africa, deflecting the 
southern equatorial waters away from the Indian Ocean and the 
Antarctic region. The melting of the Permian ice was due to 
the isolation of Australia from India, as along nearly all of the 
west coast of the former land are found Permian deposits. This 
Opening again permitted the southern equatorial currents to 


a®, Jour. Sct.—Fourtn Seriss, Vou. XXVI, No. 152.—Aveust, 1908. 


166 Seventific Intelligence. 


stream into the Indian Ocean. Koken’s generalizations have added 
value because of his detailed paleontologic knowledge. C. 8. 

2. Geological Survey of Western Australia, Bulletin 29. A 
Report upon the Geology, together with a Description of the 
Productive Mines of the Cue and Day Dawn Districts, Murchi- 
son Goldfield ; by Harry P. Woopwarp, Assistant Government 


Geologist. Part I, Cue and Cuddingwarra Centres ; pp. 93, with 


3 maps, 12 photographs, 2 blocks, and 15 plates of sections. 
Part Il, Day Dawn Centres ; pp. 48 and appendices, pp. 44-53, 
with 2 maps, 7 photographs, 1 figure, and 8 plates of sections. 
Perth, 1907.—The general conditions under which gold deposits 
occur in Murchison are in lenticular-shaped amphibolite belts, 
“surrounded or sandwiched with granites, the whole being inter- 
sected by numerous feldspathic dikes.” The oldest rock of 
the Cuddingwarra and Day Dawn districts is an amphibolite. 
Grano-diorite occurs as a magmatic intrusion into the amphibo- 
lite. A remnant flow of vesicular andesite caps Cue hill. The 
topography is diversified by the presence of “table tops” made of 
granite “which owes its weather-resisting character to iron oxide 
which has been drawn up in solution by capillary attraction 
through leaching of the rocks below”. 

Gold occurs chiefly in quartz reefs, the production being—Cue, 
212,855 ounces, Cuddingwarra, 35,461 ounces, and Day Dawn, 
847,692 ounces. BER AIS CE 

3. Lllinois State Geological Survey, H. Foster Bain, Direc- 
tor. Bulletin No 7. Physical. Geography of the Hvanston- 
Waukegan Region ; by Wattacre W. Atwoop and James W. 
GoLpTHWalIT. Pp. 93, pls. 14, figs. 52. Urbana, 1908.—It is 
becoming recognized that geologists are under obligation to 
present the main facts of their science in such a manner as to be 
of direct use to teachers and to the general reader. Following 
the lead of the Connecticut Survey, the Geological Survey of 
Illinois has planned a series of bulletins dealing with the physical 
geography of the state and designed primarily to present material 
more or less well known to experts in a form directly available 
for the intelligent reader. ‘The volume in the series listed above 
is well arranged, well written and illustrated and contains inter- 
esting material. : H. E. G. 

4, Map of Vesuvius.—The Instituto geografico militare of 
Italy, at Florence, has published a new edition (1908) of an 
excellent map of Vesuvius in colors, on a scale of 1 : 25,000 (2 
francs) indicating all determinable lava flows, with their dates, 
down to 1906; also a map of the volcano in black, in six sheets, 
scale 1: 10,000 (4.50 frances for the set) ; also two special maps of 
the cone of the volcano, 1: 10,000, before and after the eruption 
of 1906 (each, one franc). Of the general map of Italy, 1 : 100,000, 
by far the most legible edition is the one known as “ systema 
Gliamas,” in four colors, now in course of publication (1.50 
frances a sheet, 27 sheets published ; edition on thin paper prefer- 
able). W. M.D 


—_—: 


Botany. | 167 


5. A Pocket Handbook of Minerals, designed for use in 
the field or class-room, with little reference to Chemical Tests ; 
by G. MontacuE Butrer. Pp. ix, 298 with 89 figures and 5 
tables. New York, 1908 (J. Wiley & Sons).—Mineralogists and 
others who feel the need of a small volume suitable for the 
pocket, giving the important characters of the prominent mineral 
species, will find this work suited to their needs. It is printed 
in particularly clear, open form, with the emphasis upon essential 
characters and the omission of unnecessary detail; there are 
numerous illustrations. A novel feature is the series of tables at 
the end presenting the characters of the species in condensed 
form. 

BES DOTANY: 


1. The Origin of a Land Flora; a Theory based upon the 
Fucts of Alternation; by F. O. Bower, Regius Professor of 
Botany in the University of Glasgow. Pp. x1+ 727, with frontis- 
piece and 361 text-figures. London, 1908 (Macmillan & Co.).— 
Professor Bower has long been recognized as one of the ablest 
authorities on the morphology of the Pteridophytes, a group of 
plants to which the present work is largely devoted. He clearly 
shows that representatives of this group were the first plants to 
solve successfully the problems of terrestrial life, and that the 
Phanerogams, or seed-bearing plants, which are now in the 
ascendant, were derived from the Pteridophytes by further special- 
ization. ‘The evidence for these opinions is drawn almost entirely 
from the sporophyte, or asexual generation, the lines of gameto- 
phytic development in land plants reaching their culmination in | 
certain divisions of the Bryophytes. The great gap which exists 
between the bryophytic sporophyte with its continuous spore- 
cavity and lack of lateral organs and the pteridophytic sporo- 
phyte with its distinct sporangia and well developed leaves is 
still unfilled, but three main factors of advance are indicated, 
namely: sterilization of originally fertile cells; segregation of 
sporogenous tissue into distinct masses ; formation of roots and 
of appendicular organs, such as leaves, on the axis or stem. ‘lhe 
fact is also emphasized that the primary function of the sporo- 
phyte is, after all, the production of spores, so that, in the evoiu- 
tion of the Pteridophytes, the sporophyll was probably the first 
type of leaf to appear, the true foliage leaf arising from the 
sporophyll by further sterilization. On the basis of these views 
the author advances the idea that the sporophyte in the original 
_ Pteridophytes consisted of an axis attached to the soil by a root- 
system and bearing a cluster of small sporophylls, each with a 
single sporangium. The closest approach to this condition is 
apparently to be seen in such a plant as Lycopodium Selago, 
where the sporophylls are indefinite in position and essentially like 
the small foliage leaves in appearance and structure. The large 
and frequently compound leaves which are characteristic of the 
Filices and Ophioglossales have apparently been derived from 
small and simple leaves by longer continuance of growth and 
increase in complexity. Professor Bower designates the theory 


168 Scventifie Intelligence. 


which he defends as the theory of the “strobilus,” or “ strobi- 
loid” theory. He admits that the theory is hardly capable of 
direct proof and claims no originality for certain of the views 


advanced, but the evidence which he presents is clear and usually _ 


convincing. The strobiloid theory, in which the axis is the part 
originally dominant, is in marked contrast to certain theories 
proposed by earlier writers, in which the leaf either precedes the 
axis or is simultaneous with it in its appearance. A. W.-E. 

2. Linnaeus ; by Dr. VaLcKENIER SURINGAR; pp. 106. S. 
Gravenhage, 1908 (Martinus Nijhoff)—The author gives an 
account of the more important works published by Linnaeus with 
an estimate of their value and indicates the influence which they 
exerted upon later writers. In the course of the treatise he calls 
attention to certain passages, some of them now almost forgot- 
ten, which contain the germs of some of the theories which have 
played an important part in the subsequent development of bio- 
logical science. A. W. E. 

3. Die Algenflora der Danziger Bucht,; ein Beitrag zur 
Kenntniss der Ostseeflora ; by Prof. Dr. Laxowrrz, Oberlehrer 
am koéniglichen Gymnasium in Danzig. Pp. vii+141, with 70 
text-figures, 5 double plates, and a map. Danzig, 1907 (pub- 
lished by the Westpreussischer Botanisch-Zoologischer V erein).— 


The present work represents an important contribution to our 


knowledge of the algal flora of the Baltic Sea. In the first see- 


tion the numerous'species occurring in the Danzig Bay are fully - 


described and figured and artificial keys are provided for the 
determination of the genera. In the second section the flora is 
described from an ecological standpoint, and the distribution of 
the various species represented is discussed. The five double 
plates give photographic reproductions of the larger algae in 
natural size and the text-figures show microscopic details. 
A. W. E. 
4. A Text-Book of Botany ; by Professors STRASBURGER, 
Noiti, Scupenck and Karsten; third English edition revised 
with the eighth German edition by Dr. W. H. Lane; pp. x+ 748, 
with 779 illustrations, in part colored. London, 1908 (Macmillan 
& Go.).—The Bonn Text-Book of Botany has now reached its 
ninth German edition, the first one having appeared in 1895. 
The demand for so many editions within so short a time gives an 
indication of its great popularity, and it is without doubt the 
most comprehensive and satisfactory botanical text of the present 
time. When the third English edition is compared with the 
second, which was published in 1898, the most important changes 
are to be found in the section devoted to the Phanerogamia. 
This portion of the work was originally prepared by Professor 
A. F. W. Schimper, but upon his death was entirely rewritten 
' by Professor Karsten. Schimper’s treatment still appears in the 
second English edition, but 1s replaced by Karsten’s in the third. 
The three other sections of the book, devoted respectively to 
Morphology, Physiology, and the Cryptogams, are brought down 
to date, and a copious index of literature concludes the volume. 
A. W. E. 


Relief Map of the United States 


We have just prepared a new relief map of the United 
States, 48 x 32 inches in size, made of a special composition 
whieh is hard and durable, and at the same time light. The 


map is described in detail in circular No. 77, which will be 


sent on request. Price, $16.00. 


WARD’S NATURAL SCIENCE ESTABLISHMENT, 


76-104 College Ave., ROGERS EWR. NY: 


Warn’s Naturat Science EstaBlisHMENtT 


A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 
DEPARTMENTS: a 


Geology, including Phenomenal and Physiographice. 
Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, ete. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, etc. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Wards Natural Science Establishment, 
76-104 College Ave., Rochester, New York, U.S. A. 


CONTENTS 


“Page 
Art. XII.—Ré6le of Water in Tremolite and Other Minerals; | 
by E. T. —— and. JK: Chemin 422 3a ee ee 101 
XI Guerre Determination of the Radium Emana- 
tion in the Atmosphere ; by G. C. Asaman ___._-.--.= 119 
XIV.—Determination of Small Amounts of Barium in Rocks; 
by. dh. WoCLANG LEY 20 oe 123 


XV.—Heat of Combination of Acidic Oxides with Sodium: 
Oxide and Heat of Oxidation of Chromium; by W. G. 
MAX TER oc ie Ba es ed ee 125 


XVI.—Concerning Certain Organic Acids and Acid Anhy- 
drides as Standards in Alkalimetry and Acidimetry ; by 
I. K. PHEwes and Li: Ee Waeep 22 2c es ee 138 


XVII.—Comparison between Succinic Acid, Arsenious Oxide 
and Silver Chloride as Standards in Iodimetry, Acidi- 
metry and Alkalimetry ; by I. K. Parzps and L. H. 


WEED Ales oe ee ee eg ee 143 
XVIIT.—Orthoclase Twins of Unusual Habit; by W.. EH. 
Forp and KW. Timorson, Uric oe eee 149 


XIX.—Palisade Diabase of New Jersey; by J. V. Lewis _. 155 


XX.—New Horse from the Lower Miocene; by F. B. 
WsOOMIS* leo eg a ee re 


SCIENTIFIC INTELLIGENCE. 


Geology—Indisches Perm. und die permische Wiszeit, E. Koken, 165.—Geo- 
logical Survey of Western Australia, Bulletin 29: Illinois State Geological 
Survey: Map of Vesuvius, 166.—Pocket Handbook of Minerals, G. M. 
BUTLER, 167. 


Botany—Origin of a Land Flora, F.O. Bowrr, 167.—Linnaeus, V. SURINGAR : 
Algenfiora der Danziger Bucht; ein Beitrag zur Kenntniss der Ostseeflora, 
Laxowi1z : Text-Book of Botany, 168. 


ae gilt lla a ia ti 


r. Cyrus Adler, 


Librarian U. S. Nat. Museum. 


ee, ae ee SEPTEMBER, 1908. 


Established by BENJAMIN SILLIMAN in 1818. 


AMERICAN 
JOURNAL OF SCIENCE. 


Epirorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or CamsBrmce, 


| 

/ 

| 

| 

| 

| 
Proressorss ADDISON E. VERRILL, HORACE L. WELLS, | 
L. V. PIRSSON anv H. E. GREGORY, or New Haven, © 
| 

| 

| 

| 

| 


Proressor GEORGE F. BARKER, or PHILADELPHI, 
; Proressors HENRY S. WILLIAMS, or Irwaca, 
: Proressor JOSEPH S. AMES, or Battmore, 
- Me. J. S. DILLER, or Wasurncron. 


FOURTH SERIES | 


VOL. XXVI—[WHOLE NUMBER, CLXXYI.] 
No. 153—SEPTEMBER. 1908. 


WITH SUPPLEMENT. : 


NEW HAVEN, CONNECTICUT. 
1909 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE™STREET. 
/ 


Published monthly. Six dollars per year, in advance. $6.40 to countries_in the 
Postal Union ; $6.25 to Canada. Remittances should be made either by“monéy/ord e158; 
registered letters, or bank checks (preferably on New York banks). 


A NEW FIND OF RARE CINNABAR 
CRYSTALS. 


We have just received one of the most remarkable consignments of 
Cinnabar Crystals ever sent to this or any other country. They were so 
remarkable in crystallization and color that we immediately contracted for 
the entire output. They are from Wanshanchang (Hamlet of Ten Thousand 
Hills), Tungyen Prefecture, Province of Kweichow, China. They occur in 
ordinary and interpenetrating twins of bright ruby-red color. In size the 
crystals are from} to2inches. The matrix is a pure white quartz,the crystals 
always occurring in cavities, with quartz crystals; prices $5, $10, $15, $20, 
$50 and $100, and the supply is limited. 


OUR NEW BULLETIN. 


We have issued a new 10-page bulletin, covering in brief all our depart- 
ments. The announcement of this in the last number of the Scientific 
Journals, together with the announcement of an introductory reduction, met 
with so great a success and pleased so many old and new customers that at 
their earnest solicitation we have decided to extend it for another month. 
We will therefore during September only, allow a reduction of Twenty Per 
Cent on Common Minerals and Ten Per Cent on Fine and Rare Minerals, 
polished Minerals, and CutGems. The departments treated are as follows :— 


Showy Minerals, Rare Minerals, New Finds of 
Minerals, Gems, rough and cut, Mosaic Collec- 
tions, Geological Specimens, Ore Collections, 
Indian Relies, etc. 

Write us to-day for this Bulletin. 


CUT GEMS. 


Among the most remarkable and rare of our immense stock of Cut Gems 
are the following :—Green Garnets, Aquamarines, Emeralds, Tourmalines, 
Zircons, Sapphires, Sta) Sapphires, Star Rubies, reconstructed Rubies and 
Sapphires, Chrysoberyl Cats-eye, Opals, Topaz, Spinel, Pink Beryls, Sphene, 
Andalusite, and other precious and semi-precious stones. 


We shall receive in a few days a very fine lot of rare minerals from Europe ; 
they are in the Custom House now, and a list of same will be furnished on 
application. 


A. H. PETEREIT, 


81—83 Fulton Street, New York City. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


0 e—__—__— 


Arr. XXI.—On the Retardation Of. Aipha Tedys: by 
Metal Foils, and its Variation with the Speed of the Alpha 
Particles ; by T. Smira Taytor. 


[Contributions from the Sloane Laboratory of Yale College. | 


Introduction. 


In 1905, Bragg and Kleeman* observed that the a-ray 
ionization curve, obtained with a metal sheet over the source 
of the rays (radium), did not suffer the same drop from the 
normal curve at all points. The portion of the curve corre- 
sponding to radium C suffered a greater drop than that due to 
radium itself. The loss of-range of the a particle of radium C 
in passing through the sheet of metal was thus greater than the 
loss of range of the a particle from radium in passing through 
the same sheet. This seemed to be evidence that the slower 
a particles from radium were a little less affected by their 
passage through the sheet than the swifter a particles from 
radium C. 

Kucera and Masekt measured the amount by which the 
range of the a particles from radiotellurium (polonium) was 
eut down by their passage through a sheet of aluminium 
and a sheet of platinum. They measured this diminution in 
range produced by the aluminium and the platinum when the 
sheet was directly over the radiotellurium and when the sheet 
was 1°9™ from it. They found the diminution produced in 
the latter case to be less, by 10 per cent for the aluminium 
and 12°5 per cent for the platinum, than in the former case. 
They also describe experiments from which one can conclude 
that the range lost by an a particle in going through two sheets 
of dissimilar metals is independent of the order in which it 
passes through them. This appears to be inconsistent with the 
previous statement. 

Experiments made by McClung.t Rutherford$ and Levin| 
are also inconsistent with Brage’s results as well as with the 


* Phil. Mag., Sept. 1905. + Phys. Zeitschr., xix, pp. 630-40, 1906. 
¢ Phil. Mag., Jan. 1906. § Phil. Mag., Aug. 1906. 
|| Phys. Zeitschr., xv, 519-521, 1906. 


Am. Jour. Sc1.—FourtH Series, VoL. XXVI, No. 155.—SrpremeBer, 1908. 
13 


170) = —-T. S. Taylor—Retardation of “ Alpha Rays.” 


first statement of Kucera and Masek above. Rutherford 
found that the a particle loses energy at a uniform rate dur- 
ing its passage through aluminium. McClung; Levin, and 
Kucera and Masek* obtained results indicating that each suc- 
cessive layer of aluminium foil which is laid upon a radio- 
active substance diminishes the range of the a particle by an 
equal amount. 

On the other hand, Brage+ observed that the stopping 
power is not independent of the speed as stated by Rutherford, 
McClung and Levin; Bragg found that the ionization curve, 
obtained when a sheet of gold foil was directly above the 
radium C, suffered a greater drop than when the sheet was at 
a distance of 1°5°™ from it. The range of the a particle when 
~ two metals, Al and Au, were placed over the radium,. was not 
independent of the order in which they were arranged. The 
range was diminished by a greater amount when the gold foil 
was next to the radium and the aluminium over it than when 
the order was reversed. Similar results were obtained for 
aluminium and tin when their order was reversed as in the 
above case. Meyert also observed this same effect. 

Kucera and Masek,§ and Meitner,| ascribe these latter 
effects, as they observed them, to a difference in the amount 
of the scattering of the rays by the two metals. Their argu- 
ment as presented does not seem to be conclusive; for the 
scattering, if it exists, is a differential effect. 

In all the experiments cited, the method of obtaining the air 
equivalents{] corresponding to different positions of the screen 
has been to measure the range with the source uncovered and 
then with the screen in place. The difference of these values 
gives the air equivalent of the sheet. 

As, however, the variations in the air equivalent are small, 
this is not a very accurate or sensitive method; since the air 
equivalent itself (whose small variations are to be observed) is 
obtained as the difference between two much larger quantities 
(the ranges) neither of which can be determined with great 
accuracy. A method of observing the varzations of the air 
equivalent was sought which should be free from these dis- 
advantages. 

Description of Apparatus. 


The apparatus, as shown in figures 1 and 2, was similar to 
that used by Brage. The ionization chamber, which was 5™ 
in diameter and 2™" in depth, was formed by the wire gauze, 


* Loc. cit. + Phil. Mag., April, 1907. 

+ Phys. Zeitschr., xiii, 425, July, 1907. § Ibid. vii, 19, 1906. 

|| Ibid. viii, 489, 1907. 

"| By air- equivalent i is meant the diminution in the range of the a particle 
produced by the foil when placed over the source of rays, or the amount by 
which the range of the a particles in air is cut down by their passage 
through the foil. 


LAOS DS SE a ee 


Jur 


T. 8. Taylor— Retardation of “ Alpha Rays.” 


Fig. 2. 


Hig, 1c 


172 TL’. S. Taylor—Retardation of “ Alpha Rays.” 


A,and the brass plate, B. The gauze A was carefully insu- 
lated from the plate B by means of an ebonite ring G. To 
prevent any possible leakage from A to B a fine copper wire 
was run in a groove around the inner edge of this ring, then 
through the ring and around its outer edge, and, after passing 
through the large ring of ebonite R, to the earth. A second 
gauze °C was placed 3™™ below A and, being earthed, formed 
with it a second ionization chamber which prevented stray ions 
from entering the main chamber. 

The plate B was connected to one pair of quadrants of a 
Dolezalek electrometer as shown in figure 2, the second pair 
of quadrants being earthed. K is a key by means of which 
the one pair of quadrants and plate B could be earthed or 
insulated at pleasure. K rested on a brass plate M, which in 
turn was insulated from the protecting case 2 by being placed 
upon a block of sealing wax N. 

The polonium, which was used as the source of rays, being 
put upon the plate V, could be moved towards or from the — 
ionization chamber by means of the screw W, of 1™™ pitch, 
working in the nut X. Its distance from the chamber could 
be determined by the scale L and the graduated circular dise 
7. The metal sheets were placed upon the brass ring ¢, ¢ 
and could be moved to different positions by means of the 
screw H, of 1™™ pitch, working in the nut T. The distance 
of the metal sheet from the polonium could be read from the 
scale L by means of the pointer P, which extended below the 
case I’ from the moveable framework emZ. 

The polonium kindly prepared for me by Prof. Boltwood 
was deposited upon the end of a copper plug, which could be 
fitted into a block of brass and adjusted to a definite distance 
from the top of the block. The opening in the block above 
the polonium was 4"" in diameter and 6"™ high. This limited 
the cone of rays given off by the polonium so that all the rays 
would fall within the ionization chamber. 

The ebonite was carefully polished to prevent leakage over 
its surface. The entire framework of the apparatus together 
with the tin case F and the protecting case ? for the connec- 
tion of the plate B to the electrometer was grounded. Care 
was taken to avoid all outside electrostatic effects upon the 
electrometer as well. 


Method of Hxperiments. 


The block contaming the polonium was put upon the dise 
V and a metal sheet on the ring ¢, ¢, which was then adjusted by 
means of the screw H until the sheet just touched the top of 
the block, thus being 6"" from the polonium. With a con- 
stant potential of —40 volts on the gauze A and the metal 
sheet at a distance of 6™" from the polonium, the Bragg ion- 
ization curve was plotted. 


T. S. Taylor—Retardution of “ Alpha Rays,” 173 


In figure 3, curves I and II represent parts of the top por- 
tion of two Bragg curves®* as obtained when a sheet of gold 
foil was kept at a distance of 6™ from the polonium. Curve 
I was plotted from readings taken at the end of the first 
minute and curve II from readings taken at the end of the 
second minute. The curves being plotted with magnified 
ordinates have much greater slopes than they would have if 
plotted on the ordinary scale. 

The polonium, with the gold foil 6™™ above it, was then set 
at a distance of 3-0 from the ionization chamber. As can be 
seen from curves I and II, this distance was such that the 


KS] fe 
NON eae ee 


a1 


iter ay seneee 
y ] Y 


iL 6 


Fie. 3. The ordinates of curves I and II are the distances in centimeters 
of the polonium from the ionization chamber. The ordinates of III and IV 
are the distances in centimeters of the sheet of gold from the polonium 
when the polonium was kept at a distance of 3°0°™* from the ionization 
chamber. The abscissas of I and III are the deflections in centimeters of 
the electrometer needle at the end of the first minute, and the abscissas of Il 
and IV are the deflections at the end of the second minute. 


deflections obtained corresponded to two points in the slightly 
inclined (top) portions of the Bragg curves. With the polo- 
nium at this distance of 3:0™ from the ionization chamber, the 
gold foil was moved away from the polonium towards the 
ionization chamber, and the ionization was measured when the 
sheet was at various distances from the polonium. It was 
found that the ionization increased as the distance of the gold 
sheet from the polonium increased. 

In figure 3, curves III and IV were plotted with the deflec- 
tions of the electrometer needle at the end of the first and sec- 
ond minutes respectively as abscissas, and with the distances 


* This is the portion of the ionization curve which, as ordinarily plotted, 
is nearly horizontal. 


174 T. S. Taylor—Retardation of “ Alpha Rays.” 


of the sheet of gold from the polonium, corresponding to these 
deflections as ordinates (the polonium being kept at a distance 
of 3:°0™ from. the ionization chamber). Curves similar to 
III and IV in figure 3 were also plotted for the gold foil when 
the polonium was set at distances other than 03°™ from 
the ionization chamber. The distance of the polonium from 
the ionization chamber was always so chosen that the chamber 
eut the Bragg curve somewhere in the slightly inclined por- 
tion. The Bragg curves I and II were determined each time 
before making the measurements plotted in curves [III and IV 
for any given distance between the polonium and the ioniza- 
tion chamber. In this way, several sets of curves similar to 
the ones in figure 3 were obtained for each metal sheet given 
in Table II. ! 

The diminution in the range of the a particle produced by 
the sheet when 6"" from the polonium (its air equivalent in 
this position) was determined by first plotting the ionization 
curve without the sheet over the polonium and then with the 
sheet over it. The difference between the ordinates of the 
two curves corresponding to a given abscissa, which was the 
deflection of the electrometer needle, was the diminution in 
range of the a particle produced by the sheet, or what is the 
same, its air equivalent. This is the same as taking the deflec- 
tion of the needle without the sheet over the polonium when 
it is at a certain distance from the chamber, and, after placing 
the sheet over the polonium, noting how far the polonium 
and sheet must be moved towards the ionization chamber to 
get the same deflection of the needle. 


Determination of the Variation in the Air Equivalents. 


As previously stated, when the polonium, with a metal sheet 
6™™ above it, was set at such a distance from the ionization 
chamber that the chamber cut some part of the slightly inclined 
portion of the Bragg curve, it was found that, by moving the 
sheet farther away from the polonium, the ionization increased 
as the distance of the sheet from the polonium increased. This 
signifies that by moving tbe sheet away from the polonium 
the entire ionization curve was pushed upward, so that the 
part of the slightly inclined portion, which fell just below the 
ionization chamber when the sheet was 6"" from the polonium, 
fell within the chamber when the sheet was at a little greater 
distance from the polonium. 

This means that the total range of the a particles is greater 
with the sheet at the greater distance from the polonium ; and 
the magnitude of this increase in total range (which is also the 
diminution in the air equivalent of the sheet) can be obtained 
directly from the measured ionizations, given in curves, III and 
IV, and the curves I and II, fig. 3. 


ee 


-T. 8. Taylor—Retardation of “ Alpha Rays.” 175 


The diminution in the range produced by a given sheet when 
0-6 from the polonium, having been determined by the direct 
method as previously stated, the diminution at any other dis- 
tance was found from the curves in figure 3, which were plot- 
ted on finely ruled co-ordinate paper, thus facilitating the 
determination. The curves given in figure 3 were for a sheet 
of gold (A in Table II), which cut down the range 0°635™ 
when it was 0-6 from the polonium. 

The method of making the determination can be illustrated 
by finding the diminution in range produced by the sheet when 
it was at a distance of 1°8™ from the polonium. In curve III 
the abscissa, corresponding to the ordinate 1°8, which is the 
distance of the sheet from the polonium, is seen to be 1°5. 
The abscissa 1°5 in curve I corresponds to the ordinate 2°956 
in the same curve. Thus the increase in the deflection of the 
electrometer needle produced when the sheet is moved from 
0-6™ to 18°" from the polonium is the same as would be pro-. 
duced if the polonium with the sheet 6™™ above it were moved 
from 3°0™ to 2°956™ from the ionization chamber. The total 
range of the a particles when the sheet is 1:8 from the polo- 
nium, is greater by [3°0—2°956] 0°044™ than the total range 
when the sheet is 0°6™ from the polonium. In a similar man- 
ner we find from curves IV and II this change is equal to 
0-042°". The mean value for the two determinations is then 
0-043". The barometer stood at 760°2™™ when the curves 
were plotted, and hence this change of the range when reduced 
to barometer 760™" is 

760°2 XK 0°043 

760 

Since there is this difference in the total range of the a parti- 
cles in the two cases, it is evident that the sheet does not cut 
down the range of the a particles as much when it is 1°8™ 
from the polonium as when it is only 0°6™ from the polo- 
nium, and that the air equivalent of the sheet at 1:8™ distance 
from the polonium is 0°048™ less than at 0-6. 

In this manner the air equivalent of the sheet was found 
when it was at various distances from the polonium. In Table 
I are given the values of these air equivalents for the A sheet 
of gold corresponding to the distance of the sheet from the 
polonium and the range that the a particle still had in air at 
atmospheric pressure when it entered the sheet. The range 
of the a particle in air at atmospheric pressure was found to 
be 3-77. This was the distance from the polonium to the 
upper side of the gauze A when the ionization, due to the a 
particles from the polonium, produced the first noticeable deflec- 
tion of the electrometer needle above that due to the spon- 
taneous ionization of the air in the chamber.* The spontaneous 


* If the distance had been measured to the middle of the ionization cham- 
ber the range would be 3°87", which is the value usually taken. 


—0-043em 


176 TS. Taylor—fRetardation of “ Alpha Rays.” 


ionization of the air in the chamber produced’ less than 0:04™ 
deflection. This is so small as to be practicably negligible. 
But had it been larger it would have made no difference ; 

because it would have the effect of shifting all the curves in 
figure 3 to the right by an equal amount, thus not changing 
their relative positions or forms. 

Column 1 in Table I contains the distance in centimeters of 
the sheet from the polonium. Column 2 gives the range in 
centimeters of the a particle when entering the sheet. In 
column 8 are given the air equivalents in centimeters of the 
sheet corresponding to the distances in column 1 and the 
ranges in column 2 as determined when the polonium was set 
at 3°1™ from the ionization chamber. Columns 4, 5, 6, 7 and 
8 contain the same quantities as column 3, as determined 
with the polonium at 2-9, 3-0, 3-1, 2°8 and, B-Qem respectively 
from the chamber. 

TaBLE I. A Au. 


Pom pon|oamee cbr tl. ee. 

ee ae entering 3°1 2°9 30 ori 2°8 3°0 Means. 

the sheet particle 
0°6 Boa 0°635 | 0°635 | 0°635 | 0°635 | 0°635| 0°635!| 0°635 
0°8 2°97 0°626| 0°628] 0°629)| 0°626| 0°629| 0°630}, 0°628 
1°0 2277. 0°619| 0°620| 0°622| 0°618)| 0°621 | 0°623)| 0-621 
r2 Da) 7h 0°613/ 0°614| 0°616| 0°611 | 0°613| 0°616)| O°614 
1A Nay 7 0°606 | 0°609| 0°608/ 0°603 | 0°605 | 0°609]| 0:607 
1°6 Dealig 0°600| 0°601 | 0°600| 0°596 | 0°595 | 0°601 || 0°599 
les 1:97 0°592| 0°595]| 0°592| 0°589} 0°584| 0°592)| 0591 
2-0 ony 0°582| 0°581| 0°582) 0°579 | 0:574 | 0°581 || 0°580 
LD, Veo 0°572| 0:°567| 0°571/ 0°569/} 0°564| 0°570]) 0:569 
2°4 1a 7 0°556| 0°548| 0°555| 0°556| 0°557 | 0°5521|) 0°553 


The last column contains the average values of the six pre- 
ceding columns. The agreement between corresponding quan- 


TABLE IT. 

I II III IV 

Metal sheets | Thickness in cms. | Air equiv. in ems. Ratio 
A Au 0:000127 0°635 4:99 X 10° 
B Au 0:000174 0°857 4°91 10° 
A Pb 0°000284 0°923 3:24 aioe 
B Pb 0°000411 1231 3 Ocal 
A’ Sn 0°000386 0°886 2°29 10° 
B Sn 0:000799 1°800 eS) MN) 
A Al 0°:000338 0'574 1°74 10° 
B Al 0°000612 1°04 1°70 X 10° 
A Ag 0°000228 0°676 3°03 x 10° 


T. 8S. Taylor— Retardation of “ Alpha Rays.” 177 
tities in these columns shows that possible errors in plotting 
the Bragg curves (e. g., I and II in figure 3) produced no errors 
of importance in the reduction. 

In this manner, the air equivalent of the metal sheets given 
in Table II were determined for the various distances of the 
sheets from the polonium. The values obtained are found in 


Table III. 
TABLE ITI. 


Range in 
ems. of | 4 aAu|/BAu|A Pb|B Pb|ASn| BSn| A Al| BAl | A Ag 
entering 
particle. 


3°17 | 0-635] 0°857| 0-923) 1-231) 0-886] 1°800| 0°574! 1:040| 0°676 
2°97 | 0°628) 0°849| 0°914| 1°220| 0°879| 1-787) 0°574| 1029] 6-673 
2°77 =| 0°621) 0°839}| 0°903] 1°207| 0-871) 1-768] 0°573) 1°017| 0-669 
2°57 | 0°614| 0°828} 0°891) 1°193) 0°862| 1°744| 0-572) 1-005} 0°664 


2°37 0°607| 0°816| 0°878| 1-178) 0°852| 1°718] 0°571| 0°990| 0-659 
2°17 | 0°599} 0°801} 0°861| 17160} 0-840 0°568| 0°970| 0°652 
1°97 =| 0°591) 0°783} 0°843| 1°138] 0°827 0°563} 0°949| 0°644 
1-77 | 0°580/-0°761| 0°819 0°810 0°555 0°635 
1°57 0°569| 0°735 0-797 0°544 0°625 
1°37 0°553 0°532 0°613 


The values of the air equivalents for each of the metal 
sheets recorded in Table III represent the results obtained 
from a series of determinations similar to that given for A Au 
in Table I. The agreement in the values, obtained for the 
different positions of the polonium, was equally as good as that 
for the A Au. These separate tables for each metal sheet 
have been omitted for the sake of brevity and only the average 
results given in Table III. 

The curves in figure 4 represent the results as recorded in 
Table III. By noting the slope of these curves, one can 
obtain some comparison of the rate at which the air equiva- 
lents of the various sheets are changing. For the thinner 
sheet of Al, the air equivalent is almost constant for the higher 
ranges, but, as the range of the entering a particle decreases, 
the air equivalent decreases slowly and, in the lower ranges 
the decrease becomes quite marked. The thicker Al, however, 
shows a marked change in its air equivalent for even the high 
ranges. The statement of McClung, Levin and Rutherford 
that equal successive layers of aluminium foil diminish the 
range by equal amounts seems to hold true for thin sheets of 
foil when the range is high; but when the metal sheet is 
thicker, or for thin sheets when the range is low, it does not 
hold. The slight difference however in the air equivalent of 


178 T. S. Taylor—Retardation of “* Alpha Rays.” 


the thin foil when near the polonium and when farther away 
from it would scarcely be detected by measuring directly the 
air equivalents in the two positions. This is probably the 
explanation of the above statement by McClung, Levin and 
Rutherford, since their determinations were made in this 
direct way. 


Fic. 4. The abscissas are the ranges in air of the a particles when they 
enter the metal sheets; the ordinates the air-equivalents of the metal sheets. 
The eurve for BSn has the ordinates from 1°718 to 1°80 as indicated on 
right-hand side of the figure instead of 1°118 to 1°20 as shown on left-hand 
side. 


T. 8. Taylor—Retardation of “ Alpha Rays.” 179 


Since the air equivalent does decrease with the range of the 
a particle entering it, the ratio of the air equivalent to the 
thickness of a given sheet of metal should be less than the 
same ratio for a thinner sheet of the same metal. This is 
shown to be true by the last column of Table IJ. From the 
curves in figure 4, we see that the change is more pronounced 
the thicker the metal foil and the heavier the metal. 

The possibility that the observed variations in the ionization 
may be due to secondary rays is precluded by the fact that 
numerous direct determinations of the Bragg ionization curves 
with the metal sheets near the polonium and again near the. 
ionization chamber showed no irregularities in the curves, as 
would be expected were secondary rays present in any appre- 
ciable amount. 

Thus far, from a comparison of the data given in Table ITI 
and represented graphically in figure 4, I have been unable 
to deduce any definite statement relative to the rate of change 
in the air equivalents, except that, for the same metal, the 
thicker the foil the more marked is the change and that, for 
sheets of different metals of about the same air equivalents, 
the rate of change is in the order of their atomic weights; 
G.e., Al, Ag, Sn, Au, Pb). Further experiments are in pro- 
gress and it is hoped that they will furnish the desired infor- 
mation, when completed. 

In conclusion, I wish to express my gratitude to Prof. 
Bumstead, at whose suggestion these experiments were under- 
taken, for his valuable suggestions, and interest in the work ; 
also to Prof. Boltwood, who kindly prepared the polonium for 
me and gave ine many helpful suggestions. 


Results. 


The air equivalents of metal foils decrease with the range 
(i. €., with the speed) of the a particles entering them. The 
change is very small for thin foils of the lighter metals when 
the range of the a particles is high; but, when the range is 
low for thin sheets, or when the sheets are thicker, the change 
becomes quite marked. In comparing the change for sheets 
of different metals of nearly equal air equivalents, the rate of 
change is seen to be in the order of the atomic weights of the 
metals. 


New Haven, Conn., June 15, 1908. 


180 Lee—Lower Paleozoic Rocks of Central New Mexico. 


Arr. XXII.—WVotes on the Lower Paleozoic Rocks of Central 
New Mexico ;* by Witus T. Luz. 


Tur lower Paleozoic rocks are exceptionally well exposed 
in the Caballos Mountains of central New Mexico. Gordon 
and Gratont+ refer to them in a description of the lower 
Paleozoic formations in New Mexico, but attention is confined 
by these writers principally to other parts of the territory, and 
the occurrence, especially of the Cambrian and the Ordovician 
‘formations, in the Caballos Mountains, as well as their relations 
to each other and to the overlying rocks, are of sufficient inter- 
est to warrant the more definite statements contained in this 
paper. : 

The Caballos Mountains form one of the small mountain 
groups of central New Mexico and occur west of the town of 
Engle between the Rio Grande and the Jornado del Muerto. 
The northern part of the mountains consists of a faulted block 
tilted to the east and the sedimentary formations outerop in 
the precipitous western face. The lower part of the slope 
consists of granite, above which occur the Cambrian, Ordovi- 
cian and Carboniferous rocks as shown in the following section 
measured about three miles north of Shandon, a mining camp 
on the Rio Grande. With the Cambrian and Ordovician of 
this section are correlated similar rocks observed.in other 
parts of the Rio Grande Valley. 

A few species of fossils were found in the Cambrian sedi- 
ments, and these have been identified by Dr. C. D. Walcott of 
the Smithsonian Institution. Fossils collected from the Ordo- 
vician rocks have been examined by E. O. Ulrich of the 
United States Geological Survey, and the quotations given 
in the paper are from his written report. The Ordovician 
fossils are not well preserved and specific identification is 
difficult. 

A thickness of 1000 feet or more of the granite is exposed 
in the cliffs. The rock is massive and coarsely crystalline, 
although schist and gneiss occur in some places. Its surface 
was apparently eroded in early Cambrian time to a nearly 
level plain upon which the sedimentary rocks were deposited. 
The coarse-grained and, in some places, conglomeratic quartz- 
ite at the base of the Cambrian grades upward into the green 
shale, in which the Cambrian fossils occur in great abundance 
at several horizons, some close to the basal quartzite, others 
near the top. 

* Published by permission of the Director of the U. S. Geological Survey. 


+ Gordon, C. H. and Graton, L. C., Lower Paleozoic Formations in New 
Mexico, this Journal, xxi, pp. 390-395, 1906. 


Lee—Lower Paleozoic Rocks of Central New Mexico. 181 


Section of Rocks exposed in the Caballos Mountain three miles 
north of Shandon, New Mexico. 


No. Ft. 
(1) Limestone, blue, massive, fossiliferous, in thick plates 
separated by dark colored shales (age, lower Pennsyl- 


ANNs UY Fake 2 A as Se he eS aie 600 
(2) Limestone, cherty in places, white to brown (age not 
determined) ey Meee LN mere ts 500 


(3) Limestone, cherty, massive, cliff- making. The following 
fossils occur near the top: Rafinesquina cf. hingi, 
Plectambonites saxea, Plectambonites n. sp., Favosites 
asper, Zygospira recurvirostris (Richmond mutation), 
Rhynchotrema capax (age, late Ordovician) -.------ 600 

(4) Shale, dark green, containing Odbolus ( Westonia) Ston- 
eanus Whitfield, Obolus sinoe Walcott? (The fol- 
lowing fossils were found in talus derived apparently 

-from this horizon : Plectorthis desmopleura Meek, 
Obolus sinoe Walcott, Lingulella acutangula Roe- 


mere (ase, upper. Cantbriait)oi23 22565 2003.02 90 
Pee aRL Albee fe ee ht see lee Fe. AO 
(Gp eGranite. 22.25: Ee ee ae SSE eee ae etary See mag ? 


Cambrian sediments occur also in Cerro Cuchillo, a hill con- 
sisting of rocks faulted and tilted steeply to the east, that 
stands a few miles west of the Rio Grande near the northern 
end of the Caballos Mountains. The rocks were probably 
originally continuous with those of the Shandon region, but 
the two exposures are 20 miles apart and are separated by a 
zone of profound faults. Here, as in the Caballos Mountains, 
the Cambrian sediments are about 100 feet thick and consist 
of a basal quartzite resting on granite and overlain by green- 
ish shale in which were found fragments of trilobites and the 
same species of brachiopods found near Shandon. The shale 
is overlain by chertv limestone similar to the Ordovician of 
the Caballos Mountains but no fossils were collected from it. 

The Ordovician rocks of the Caballos Mountains are appar- 
ently conformable with the Cambrian, but as shown below, 
there is probably a considerable time-break between them. 
They consist of massive cherty limestone and form a conspicu- 
ous cliff 600 feet high. The rocks of undetermined age 
above are less cherty and not so massive, but in some places 
can be distinguished from the lower chert only by careful 
examination, the two forming a single cliff 1100 feet high. 
The fossils from the lower chert indicate Richmond or late 
Ordovician age, and in the absence of evidence, the upper 
chert also may be late Ordovician or it may be Silurian. 

The chert is overlain in the Caballos Mountains by 600 feet 
of limestone of Pennsylvanian age. No fossils of intervening 


182 Lee—Lower Paleozoic Rocks of Central New Mexico. 


age were obtained and it is possible that both Mississippian 
and Devonian rocks may be found here, for they are known 
to occur at Lake Valley and at Hillsboro, a few miles to the 
west.* 

About eight miles south of Shandon near the south end of 
the Caballos Mountains, the older Paleozoic rocks are again 
exposed, although considerably folded and faulted. No 
detailed section of them was made owing to their disturbed 
condition, but the following generalized section with estimated 
thicknesses indicates their order of succession : 


Section of Rocks exposed near Red Cabin, eight miles south of 
Shandon, New Mexico. 


. Thickness 
as estimated: 
(1) Limestone, blue (age, lower Pennsylvanian) .. _.------ 500 

Unconformity of erosion. 
(2) -Shale;:black- fage,. Devonian (?)-): 2.022.255 22a 1-300 
(3)- Limestone, cherty (age, late Ordovician) - 22-22 a25emes 500 
Angular unconformity. 
(4) Limestone, cherty (age, early Ordovician) ..-...------ 200 
(5) Quartzite (age/not determined) _=_ 9)22 422. a3 eee 300 


(Base not exposed.) 


A few fragmentary fossils were found in the cherty lime- 
stone (No. 4) of the Red Cabin section. Although they are 
very poorly preserved, Ulrich recognizes them as Ophdleta ef, | 
complanata and Hormotoma ct. artemisia (Billings species) 
and refers them with some confidence to the lower Ordovician 
(Beekmantown). 

Cherty limestone about 500 feet thick, that is probably 
equivalent to the lower chert (No. 3) of the Shandon section, 
lies unconformably upon the early Ordovician chert in some 
places and upon the massive quartzite (No. 5) of the Red 
Cabin section in other places. Fossils were collected from it 
at the base, near the middle, and at the top, but as Ulrich 
includes the three lots in one general fauna, they may be 
combined as follows, together with his notes concerning them; 


Rafinesquina, n. sp. (characteristic of Western Richmond). 
Rhynchotrema capax (most characteristic Richmond fossils). 
Favosites asper (late Ordovician and Clinton). 

Petraia, sp. undet. 

Lindstromia, sp. undet. 

Dalmanella (2? Schizophoria), sp. undet. 


* Gordon, C. H. and Graton, L. C., Lower Paleozoic Formations in New 
Mexico, this Journal, xxi, pp. 394-395, 1906. 


Lee—Lower Paleozorve Rocks of Central New Mewico. 183 


Streptelasma or Petraia, sp. undet. Specimen shows only the 
exterior. So far as can be seen it recalls Silurian apecies rather 
than Ordovician, 

Nematopora, cf. granosa Ulrich, a Trenton species of Min- 
nesota. 

Schuchertella sp., closely allied and possibly the same as the 
Silurian S, subpluna (Conrad). 

Fragments of a brachiopod recalling Silurian species of Stro- 
phonella. 

Small subcircular orthoid, suggesting relations to O. (Lhipido- 
mella) hybrida. 


Atrypoid brachiopod, possibly Zygospira but distinct from 
all American species of that genus known. 

Brachiopod of undetermined affinities. In its general aspect 
it recalls Russian species of Porambonites, but the surface of 
the shell is not porous. 


Ctenodonata, sp. undet. 

Lophospira, cf. gyrongonia McCoy and medialis Ulrich. 

Lophospira, sp. allied to gyrongonia McCoy. 

Fragment of a gastropod, apparently of the same species as 
the Clinton form doubtfully referred by Foerste to PEROT OUEES 
sinuatus Hall. 

Trochonema, n. sp. 

EHunema sp. near &. robbinsi Ulrich. 

Eecyliomphalus, sp. undet. A small, incomplete example of a 
closely coiled species reminding of £. gotlandicus Lindstrom and 
Hi. contiguus Ulrich, the former Silurian, the latter middle Ordo- 
vician. 

Loxonema? The specimen is a fragment (consisting of the 

greater part of two whorls) reminding rather strongly of the Z. 
murrayanum described by Salter from Black River limestone in 
Canada. 


In a local uplift about one mile west of Red Cabin, I found 
the following fossils in chert that is presumably the same as 
that of No. 3 of the Red Cabin section : 


Calopoecia canadensis 
Havosites axper : 

? Columnaria alveolata 
Platystrophia dentuta var. 
Petraia 

Lindstromia 

Dalmanella (? Schizophoria) 
Lophospira 

Loxonema. 


South of Red Cabin, about two miles and five miles respec- 
tively, the latter loc salty about six miles northwest of Rincon, 


184 Lee---Lower Paleozoic Rocks of Central New Mexico. 


300 feet of cherty limestone is exposed at the foot of the cliffs. 
The rocks are continuous with the upper chert (No. 3) of the 
Red Cabin section and yielded the following fossils : 


Petraia, sp. undet. (near Streptelasma profundum (Black 
River) and S. caliculuris (Silurian)). 7 . 
Lindstromia, sp. nov. | 
Orthis, near davidsoni.and flabellum. 
Dalmanella (? Schizophoria), sp. undet. 
Clorinda? sp. undet. 
Atrypa sp. nov. (near Zygospira putilla and Atrypa margina- 
iis). 3 
? Huomphatus sinuatus (Hall) Foerste (Clinton species). 
Lophospira, sp. undet. 
Trochonema “ — « 
Eunema, near robbinsi, a Trenton form. 
Loxonema 
Nucleospira ? 


Ulrich states that all of the fossils from near Red Cabin, 
with the exception of the two lower Ordovician forms, belong 
at the same general horizon and are of Richmond or late Ordo- 
vician age, and suggests that the absence of fossils indicating 
Ordovician horizons intervening between this and the early 
Ordovician rocks below the uncomformity “ probably points to 
conditions similar to those prevailing in the vicinity of El Paso 
75 miles to the south, where the Richmond commonly rests 
directly on Beekmantown.” Since a lower Ordovician chert 
occurs unconformably below the Richmond in the Red Cabin 
section, and this in turn rests upon a massive quartzite that is 
not represented in the Shandon section, it is probable that the 
apparent conformity of the Cambrian and Ordovician in that 
section is deceptive and that a time interval of considerable 
duration is represented between the two formations. 

According to Ulrich, there are certain elements in the faunas 
that suggest Silurian rather than Ordovician age, but, except- 
ing the two early Ordovician species, he is inclined to regard 
the fauna as representing one of the phases of the Western 
Richmond. Hestates that “ very few of the species are closely 
related to ordinary described American forms, but they are 
very similar and perhaps identical with species occurring in the 
Borkholm limestone of the Russian Baltic Provinces. In the 
absence of authentic examples of the Russian species, I hesi- 
tate as yet to identify these New Mexican fossils with them. 
The associated coral bed represented west of Red Cabin, how- 
ever, is widely distributed in America west of the Mississippi 
and occurs also in the Island of Anticosti. Its position is 
within the upper part of, or just above, the Maquoketa shale 
of the Mississippi Valley. The highest horizon represented 


Lee—Lower Paleozoic Rocks of Central New Mexico, 185 


east of Red Cabin and also north of Rincon, may be correlated 
more or less definitely with the Maquoketa shale and this with 
the upper Richmond of Ohio and Indiana.”’ 

No fossils were found in the black shale (No. 2) of the Red 
Cabin section, and it may be Devonian as stated by Gordon 
and Graton.* It is apparently this shale that these writers 
have in mind when they state that the Devonian is represented 
in the Caballos Mountains, although it does not appear from 
their descriptions that fossils were found or other evidence of 
age except stratigraphic position obtained. The overlying 
Pennsylvanian limestone rests in some places upon this shale, 
in other places upon the Richmond chert, as shown in the Red 
Cabin section, and in still other places upon the chert overlying 
the Richmond, as in the Shandon section. No rocks of Mis- 
sissippian age were found, but their occurrence a few miles to 
the west suggests that the Mississippian limestones once 
extended over this region and that they, together with the 
greater part of the Devonian, were removed by erosion previ- 
ous to the deposition of the Pennsylvanian sediments. 

A small exposure of cherty limestone was found beneath 
the Pennsylvanian limestone in the northern slope of the 
Robledo Hills about 15 miles south of Rincon. In this chert 
I found the following fossils : 


Lophospira, two small undet. species. 

Lophospira, ? larger species. 

Trochus ? sp. undet. 

Bucania ? sp. undet. 

Trochonema, sp. undet. 

Hotomaria, sp. undet. 

Pentameroid shell agreeing with Steberellay except 
that it has no fold nor sinus. 


Ulrich regards these as constituting a part of the Richmond 
fauna just described, but states that they are c.early distinct 
from other Richmond faunas so far as known from the west 
and southwest. His statement that more perfect fossils may 
prove that the fauna is Silurian finds support in the occur- 
rence of Silurian rocks in the Franklin Mountains 35 miles to 
the south.t A thickness of only a few feet of the rocks is 
exposed in the Robledo Hills and their relations to other for- 
mations could not be determined. 

A summary of the foregoing statements regarding the lower 
Paleozoic rocks of central New Mexico may be given as fol- 
lows: (1) Rocks of upper Cambrian age about 100 feet thick 
rest upon an eroded plane of granite. (2) Rocks of early 


* Ibid: pa 39h 
+ Richardson, G. B., U. S. Geol. Survey, El Paso Folio. 


Am. Jour. Sc1.—Fourta Series, Vout. X XVI, No. 153.—SEPTEMBER, 1908. 
14 , 


186 Lee—Lower Paleozoic Rocks of Central New Mexico. 


Ordovician (Beekmantown) age occur in some places, but are 
apparently absent in other places. (8) Rocks of Richmond 
age are well developed and rest in some places upon Beekman- 
town and in other places apparently upon Cambrian. (4) The 
Richmond is separated from the Beekmantown by an uncon- 
formity that apparently represents a long time interval. (5) 
Certain elements in the fauna which is here described as Rich- 
mond are suggestive of Silurian rather than Ordovician age, 
and some of the cherty limestone may belong in the Silurian 
system. (6) Rocks of possible Devonian age occur in the 
Caballos Mountains, but no fossils were found in them. (7) 
No Mississippian rocks were found and Pennsylvanian lime- 
stones rest in some places upon the Devonian (?) shale and in 
other places upon the Ordovician chert. 


Washington— Kaersutite from Linosa and Greenland. 187 


Art. XXIIL.—On Haersutite from Linosa and Greenland ; 
by Henry 8S. Wasuineton; with Optical Studies by 
Frep. Eucene Wricur. 


Introductory Note.—While visiting the small island of 
Linosa, off the coast of Tunis, for the Carnegie Institution in 
the summer of 1905, I found small erystals of a black amphi- 
bole, accompanied by others of a glassy white, cleavable min- 
eral, apparently a feldspar,* among the lapilli of a small, 
parasitic cone of Monte Rosso.t The presence of amphibole 
erystals here had previously been noted by Speciale.t Similar 
crystals were also said to be found near I Faraglioni, but this 
locality was not visited. Apart from these occurrences, am- 
phibole is quite unknown in the lavas of Linosa, but the peculiar, 
triclinic aenigmatite (cossyrite) is met with, though not abun- 
dantly, and a kaersutite-ike hornblende as well, in the lavas of 
the near-by island of Pantelleria. 

Chemical analysis showed that the Linosa hornblende is very 
high in titanium, and that in this, as well as in other respects, 
it closely resembles the kaersutite of Greenland, which was 
partialiy described in 1884 by Lorenzen.§ A comparative 
investigation of the two minerals was therefore determined on, 
the chemical work being done by me and the optical determi- 
nations being very kindly undertaken by Dr. Wright, to whom 
I am deeply indebted for his valuable and hearty collaboration. 
Through the kindness of Professor N. V. Ussing, of Copen- 
hagen, we obtained a piece of one of the best of Lorenzen’s 
original specimens of kaersutite, and we take this opportunity 
to express our sincere thanks to him for his courtesy and great 
liberality, without the aid of which the comparison would have 
been sadly incomplete. 


The Linosa Amphibole. 


Physical Characters.—The Linosa amphibole is monoclinic 
in crystal system and prismatic in habit. It occurs in roughly 
developed crystals and fragments from 5 to 20™™ long by 3 
to 8™™ thick, and bounded by the faces of the unit prism m 
(110) and the clinopinacoid 6 (010). Terminal endings are usu- 
ally absent, but a few of the crystals show the common forms 
p (101) and r (011), which, however, were too imperfect to 
admit of accurate measurement with the goniometer. Cleavage 
parallel to m (110) is highly perfect, viving an angle of 55° 22° 

* A description of this mineral will be given in a separate paper. 
+ H. S. Washington, Jour. Geol., vol. xvi, p. 10, 1908. 


tS. Speciale, Boll. Com. Geol. Ital., vol. xv, p. 2, 1884. 
§ J. Lorenzen, Medd. Gronl., vii, p. 27, 1884. 


188 Washington—Kaersutite from Linosa and Greenland. 


(Wright) with observed limits of + 2’, measured on cleavage 
fragments with a two-circle voniometer with reducing attach- 
ment. The reflection signals were fairly sharp and satisfactory. 
No cleavage or parting after 100 or 001 was noted with cer- 
tainty, and whenever cleavage is not developed the fracture is 
conchoidal. The hardness is 6 and the mineral is very brittle. 
Before the blowpipe it fuses readily to a black, slightly mag- 
netic bead. 


Fic. 1. Kaersutite from Linosa. Etch piton 110, HF. x 480. 


The specitic gravity was carefully determined with the pye- 
nometer on about 2 grams of selected fragments, entirely free 
from adhering bits “of scoria or feldspar and quite free from 
inclusions so far as could be seen with a lens. With this mate- 
rial the density at 13° was found to be 3°336 (Washington), a 
figure which may be accepted as representing the true value. 

Etch figures on m (110) were produced by immersing cleav- 
age fragments in hot commercial hydrofluoric acid (on a steam 
bath at 100° ) for a period of 30 seconds. Further action was 
stopped by plunging the platinum basket containing the frag- 
ments into cold water. Under these conditions of experiment 
well-formed etch pits resulted, from 0:01 to 0-04" long and 
about half as wide. Different stages of development are illus- 
trated in figures 1-3, which are reproductions of photomicro- 
graphs of the figures in reflected light. In each ease the vertical 
edge of the photograph is parallel to the prism-axis. A com- 
parison of these figures with those obtained by Daly,* and later 
by Wright,t shows that they resemble in certain features the 

Hane A. Daly, Proc. Amer. Acad. Arts and Sci., vol. xxxiv, pp. 3383-429, 
1899. 


+F, E. Wright, Tschermak’s Min. Petr. Mitth. vol. xix, pp. 308-320, 
1899. 


Washington—Kaersutite from Linosa and Greenland. 189 


pits formed on lustrous basaltic hornblende and in other par- 
ticulars the etch figures on barkevikitic hornblende. The etch 
figures on the faces of the prism zone prove with certainty that 
the mineral is monoclinic, and that it belongs in the general 
group of the dark, highly ferruginous, aluminous amphiboles, 
which are commonly referred to the hornblendes. 

Optically, this amphibole is remarkable in several of its 
properties. The color is an intense jet black, with highly vitre- 
ous, splendent luster. The streak is light brown. In common 
with amphiboles of this group, it is brown to pale brown in 
transmitted light, and is strongly pleochroie: c=dark brown, 


2 3 


Figs. 2, 3. Kaersutite from Linosa. Etch pits on 110, HF. Fig. 2, 
x 360; fig. 3, x 240. 


almost opaque, b=brown, a=pale olive brown or olive green; 
absorption, c >b >a. The natural color of the mineral is so 
deep and the pleochroism so strong that the normal inter- 
ference colors are greatly modified, and the observation of 
the optic axes and similar optical phenomena is considerably 
hindered. 

Owing to the extreme brittleness of the cleavage fragments, 
it was found difficult to prepare sections parallel to the clino- 


190 Washington—Kaersutite from Linosa and Greenland. 


pinacoid, and the extinction angle was measured only on the 
cleavage face m (110). By using the etch figures as a ‘basis for 
orientation, the extinction angle cAc was found to be +1-4° 
(in the acute angle 8) in white light,* as indicated by the arrow 
in figure 1. This direction presupposes the standard erystallo- 
graphic orientation of the amphiboles by Tschermak. This 
extinction angle is noteworthy because of its positive character, 
and it is readily discernible, although so small that Gn the 
absence of corroborative data) it might be considered to be 
due to observational error alone in the deep-colored flakes. 
The dispersion of the bisectrices is very slight, and practically 
the same value was obtained by using sodium light as that for 
white light. In convergent polarized hght the interference 
phenomena are only moderately clear and distinct. The optic 
axes lie in the plane of symmetry (010), and the optical charac- 
ter is negative. 

The refractive indices were determined on a very perfect 
cleavage flake with an Abbé total refractometer, a solution of 
sulphur in methylene iodide, with refractive index 1°7882, 
being used. The observations were made in sodium light, and 
the following values obtained : 


Average angle Equivalent refrac- 
observed. tive index. 
—— G7 aadlsy 1°:760 
iS 657° 78: 1°730 
== (HO. Bie 1°692 
(ip 


0'068, Vie B = 0°029 6B —a = 0°039 


The optic axial angle calculated directly from these refrac- 
tive indices is 2V = 79° 54’. 

The boundary shadow for a was much more distinct than 
those for 8 or y, and could be determined with greater accu- 
racy. In the values given for 8 and y an error of + 0-002 is 
easily possible. The fact that hght waves vibrating along ¢ and 
b were strongly absorbed undoubtedly exerted an influence on 
the relative intensity of the phenomena observed, and caused 
the faintness of the 8 and y curves of total reflection. 

A somewhat smaller value for 2V was obtained by meas- 
uring the angle of the optic axes directly in another section cut 
approximately normal to the acute bisectrix, by the method 
described by Wright.| The deep color of the mineral impaired 
the accuracy with which the determinations of the positions of 
the optic axes could be made, so that the results are but approx- 
imate at best. In two different portions of the same section 
thus measured the values 2V = 71° and 72° were obtained. 


* Average of 10 measurements, with observed limits +0°6°. 
+ F. E. Wright, this Journal, vol. xxiv, p. 317, 1907. 


Washington—Kaersutite from Linosa and Greenland. 191 


While in general the probable error for this method should not 
exceed 2°, the intense color of the amphibole has evidently 
affected this limit appreciably, as it is not probable that differ- 
ences exist in the chemical composition of the material suth- 
ciently great to cause the optic axial angle to vary 9°. The 
optic axial angle apparently lies between the two extremes, 
Gkxand: 19° 54’, but it is thought that the latter more closely 
approaches the true value. 

Chemical Composition.—For the chemical analysis several 
grams of selected crystal fragments were coarsely crushed, 
washed free from dust, and the material (dried at 110°) care- 
fully picked out under a lens. The only adherent impurities 
were feldspar, limonite, and particles of the scoria, and all frag- 
ments showing traces of these were excluded. Thin sections 
of fragments showed but very few small inclusions of magnet- 
tes but these were separated by treatment with an electro- 
magnet, only a very small amount being thus extracted. It is 
believed that the material as finally pulverized for analysis was 
practically free from extraneous matter. Treatment with acid 
for purification was not resorted to, as the mineral is partially 
decomposed by acids.* 

The methods of analysis employed were those advocated by 
Hillebrandt+ and the writer,{ about one gram being taken in 
each case for silica, alumina, etc., and for the alkalies; about 
one-half a gram for ferrous iron; and 0°8 gram for fluorine. 
The alkalies were determined by Lawrence Smith’s method, 
titanium colorimetrically (a mean of three closely agreeing 
determinations), and manganese by precipitation with bromine. 
Ferrous iron was determined twice by the simple Pratt method, 
freshly standardized permanganate solution being used. The 
figure given (3°96) is the mean of 3:99 and 3:94. These results 
indicate that there was no appreciable oxidation of the FeO in 
the finely ground powder during the interval of a year which 
elapsed between the two determinations. 

* In a recent criticism (Geol. Mag., dec. v, vol. iv, p. 161, 1907) of a pre- 
vious paper of mine, Mr. T. Crook says that evidence is needed of the absence 
of inclusions of ilmenite, etc., in this hornblende, and he expresses doubts 
as to ‘‘ the view that titanium enters vitally and in any serious quantity into 
the composition of ordinary ferromagnesian minerals.” The amount of TiO, 
found would imply, if existent only as ilmenite, the presence of 17 or more 
per cent of this, and it is hoped that the details given here will suffice to 
show that but minimal amounts, if any, of ilmenite or titaniferous magnet- 
ite were present. As regards his latter doubt, Mr. Crook seems to be unaware 
of much recent and highly trustworthy work which has been done in chem- 
ical mineralogy, and which proves conclusively that titanium does enter 
vitally and often in considerable amount into the composition of the ferro- 
magnesian minerals. 

+ W. F. Hillebrand, Bull. No. 305, U.S. Geol. Surv., 1907. 


{ H. S. Washington, Manual of the Chemical Analysis of Rocks, New 
York, 1904. 


192 Washington—Kaersutite from Linosa and Greenland. 


SiO, Tene: 40°85" 681 
HO Peete sa 8°47 "106 
LY Oi eg ae none 
NE Oa eee 9°89 097 
IDO) eee 8°85 056 
Ke@ aie ee 3 96 "055 
MiniQrecee so) One 002 
INTO ee ee 0:10 001 
MoO C35. 12°47 312 
ClO seco ee BE 1G) Tap 
BAO me sos none 
ING Ono ah Be 22con 032 
Ke Oto: 0°63 “007 
PU Ogee eons 0°19 "010 
Oe es we EOS ‘007 
99°98 


Hornblende from Linosa.* Washington, analyst. 


In its general features, this analysis closely resembles many 
analyses of basaltic hornblendes, such as those made by Schnei- 
der.t Alumina is, however, decidedly lower, and a most strik- 
ing character is the very high percentage of TiO,, the amount 
of which is nearly twice that reported for most basaltic horn- 
blendes. The character of the material used for the analysis 
precludes the possibility that this high figure is due to admix- 
ture of titaniferous magnetite or ilmenite, as no appreciable 
amount of such inclusions could have been present, so that the 
titanium must be regarded as belonging to the hornblende 
molecule. The analysis will be discussed later, in connection 
with others, and attention need be called here only to the fig- 
ures for the iron oxides and the percentage preponderance of 
ferric over ferrous oxide. 


The Kaersut Amphibole. 


Occurrence.—A_ peculiar, highly titaniferous amphibole 
from Kaersut, Nugsuaks Peninsula, on the shore of Umanak 
Fjord, Greenland, was described by J. Lorenzen,{ who called 
it kaersutite. According to Steenstrup (as quoted by Loren- 
zen), the kaersutite occurs in a vein or dike, 2 to 6 inches 
wide, which cuts a horizontal sheet of peridotite 120 feet 
thick. It is accompanied by plagioclase, titaniferous ore, an 
astrophyllite-like mica, and some pyrite, with zeolites, calcite, 
and quartz as secondar y minerals. This sheet of peridotite is 


* This earn. has been published in Rock Minerals, by J. P. ae” 
New York, 1906, p. 530. 

Ee: Schneider, Dericciae Kryst., vol. xviii, p. 580, 1890. 

tJ. Lorenzen, Medd. Groeniand, vol. vil, D. Pile 1884. 


Washington—Kaersutite from Linosa and Greenland. 193 


undoubtedly the same as that mentioned by Phalen* in his 
description of the rocks of the Nugsuaks Peuinsula, who 
speaks of it as forming a cliff 200 feet high, calls it picrite, and 
gives a petrographic description. The kaersutite-bearing vein 
is not mentioned by him. 

The specimens sent us by Professor Ussing show a rather 
coarsely granular mass of feldspars pierced in all directions by 
prisms of the black hornblende, which run up to 3° in length 
by 5™™ in thickness. The rock is far from fresh, and is stained 
brown and yellow with iron, and here and there a pale green. 
Small grains of magnetite or ilmenite and many apatite crys- 
tals in water-clear prisms 5™" in length are present, and a few 
small specks of pyrite were seen, but we could not detect with 
certainty any of the mica megascopically. 

In thin section the texture is distinetly that of a granitoid 
rock rather than that of vein material. The structure is decid- 
edly miarolitic. The most abundant mineral is a plagioclase, 
in anhedral development, whose extinction angles indicate the 
average composition Ab,An,. (Extinction angle on 001 = 13°; 
y about 1570 and a slightly > 1:56.) With this is some 
alkali-feldspar, which shows some microperthitic features and 
is apparently highly sodic, though it is mostly cloudy and con- 
siderably decomposed. The brown kaersutite prisms are promi- 
nent, and show the optical properties to be described later. 
Small stout prisms of fresh augite are not uncommon. For 
the most part they are colorless in the interior and slightly 
greenish toward the border, but there are also some small anhe- 
dra of a highly pleochroic, brilliant grass-green augite which 
occasionally forms a border about the less colored variety, and 
is apparently the chromiferous augite mentioned by Ussing.t 
Indications only of the violet angite described by Ussing were 
observed by us. 

Small thin plates of light brown biotite occur. These are 
intensely pleochroic, the color for rays vibrating parallel to the 
cleavage cracks being a very deep purplish red, while perpen- 
dicular to this they are pale yellowish brown. They show no 
analogy with astrophyllite. Some small grains of opaque ore 
are present, but these only rarely occur as inclusions in the 
hornblende and no pyrite was visible in our sections. Deep 
red goethite was observed as an alteration product of the mag- 
netite or pyrite. Apatite is very abundant, in long, clear 
prisms, and is a frequent inclusion in the hornblende. It was 
also noted by Ussing as an abundant constituent. Patches of 
greenish chlorite minerals occur and are the cause of the occa- 
sional green color of the rock. 


*W. C. Phalen, Smithson. Misc. Coll., vol. xlv, p. 194, 1904. 
+ In Rosenbusch, Mikr. Phys., vol. i, pt. 2, p. 237, 1905. 


194 Washington—Kaersutite from Linosa and Greenland. 


A hornblende which apparently resembles that of Kaersut is 
deseribed by Phalen* as occurring in a fine-grained quartz- 
monzonite at Alanekerdlak on the Nugsuaks Peninsula. From 
our examination of the original specimen, kindly loaned by 
Dr. G. P. Merrill of the Smithsonian Institution, it appears 
that, while the rock resembles that of Kaersut, except in its 
finer grain, this hornblende differs from ours, being of a yellow- 
brown rather than a red-brown color, and with somewhat 
different pleochroism. The optical characters were not deter- 
mined, but it would appear to be titaniferous and related to 
that which we are describing. 

Physical Properties—The Kaersut amphibole is mono- 
clinic and forms prisms which reach a length of 3° and thick- 
ness of 5™" in our specimens. They are bounded by the prism 
m (110) and the pinacoid 6 (010). The terminations are usually 
poor, but some crystals show the presence of steep domes or 
pyramids, whose symbols could not be determined. These are 
also to be seen in the thin sections. Ussingy gives (110), (011), 
(101), and more rarely (121) and (010), as ‘the forms observed 
by him. ‘Twinning was observed in several of the sections. 
In one case the twinning plane was probably a steep dome, 
making an angle of 15° “with the cleavage lines, and showing 
in several places several narrow lamellae due to repeated twin- 
ning. The cleavage lines cut this twinning trace uninterrupt- 
edly. This crystal is shown in fig. 4, from a photograph 
kindly made for us by Prof. J. Volney Lewis. The extinction 
is parallel to the right of the twinning line and 17° to the 
left. The crystals are seen in thin section to be frequently 
crossed by narrow cracks (seen as dark lines in the figure). 
Some of these are irregular, but many are straight and parallel, 
crossing the cleavage lines of 110 at about 32°. For the angle 
Oe 110 measured on the cleavage surfaces, Lorenzen (p. 39) 
gives 55° 29’ (the mean of 55° 25’ and 55° 33°), while Ussing 
obtained 55°35’. On an excellent cleavage piece, giving sharp 
-reflexion signals, Wright obtained 55° 35), while on less satis- 
factory fragments the values were 55° 34’ and 55° 23’. We 
therefore consider that 55° 35’ best represents the value. For 
other angles Ussing gives the following: 101,011 = 34° 16’, 

Ol 4 140 = 76° 51’ 1101. O11 = eee ope cleavage is 
highly perfect, and where it is not developed the fracture is 
conchoidal. We found the hardness to be about 6; Lorenzen 
gives it as 5°5. ‘The mineral is very brittle, and fuses readily 
betore the blowpipe to a dark, magnetic bead. 

The specific gravity as determined by Washington with the 
pycnometer on about one gram of very carefully selected frag- 

*W.C. Phalen, loc. cit., p. 207. 

+N. V. Ussing, in Rosenbusch, Mikr. Phys., vol. i, pt. 2, p. 286, 1905. 


Washington— Kaersutite from Linosa and Greenland. 195 


ments was 37137 at 25° C., while Ussing obtained 3°237 (tem- 
perature not stated) and Lorenzen 3-04 at 18°. 

The extinction angle on m 110 was found to be ¢:¢ =—78° 
in the obtuse angle 8, measured in sodium light (an average 
of 14 readings on different sections). In Li light the extine- 
tion was ¢ A ¢ = —9°3°, which would indicate that there is some 
slight dispersion of the bisectrices with e A ty, < ¢ A Cy; That 


it is shght, however, is evident from the comparatively sharp 
position of extinction in ordinary light. Ussing gives the 


+ 


extinction angle as ¢:c = about 10° in the obtuse angle 8, but 
does not state whether this was measured on 010 or 110. He 
remarks that it is somewhat greater for red than for green, 
which is in accord with the observations of Wright. The 
plane of the optic axes is the clinopinacoid. 

The refractive indices were determined directly by the 
method employed in the preceding case, and were found to be 
as follows: a = 1°676, 8 = 1°694, y = 1-708, the probable 
error being less than + 0:02. This gives for the birefrin- 
gences: y — a = 0:0382, y— B =0°014, B-—a=0:018. The 
optic axial angle calculated from these indices is 2V = 82° 6’, 
while measurement of a section nearly perpendicular to the 


196 Washington—Kaersutite from Linosa and Greenland. 


Fics. 5, 6, Kaersutite from Kaersut, Greenland. Etch pits on 110, HF; x 120. 


7 


Fic. 7, Kaersutite, Kaersut, Greenland. Etch pits on 110, HF; x 480 


Washington—Kaersutite from Linosa and Greenland. 197 


acute bisectrix on the universal stage gave 2V= 81°. This 
value can be considered only fairly accurate because of the 
deep color of the mineral which tends strongly to veil the 
optical phenomena, but it agrees satisfactorily with the calcu- 
lated value, much better, indeed, than in the case of the 
Linosa hornblende. 

Chemical Composition.—The chemical analysis was carried 
out on about 2 grams of carefully selected fragments, which, 
after crushing and washing free from dust, were treated with an 
electro-magnet to remove the few particles which contained 
ore grains. The microscope indicated that but few of these 
were present as inclusions, and the very small amount thus 
removed is in harmony with the observations. The only inclu- 
sions of note are of apatite, the needles of which penetrate 
the hornblende to a very considerable extent. As the mineral 
power was somewhat acted on by acid it was thought best not 
to remove these inclusions by its use, but to correct the analy- 
sis for their presence by determining P,O,. Apart from these 
apatite inclusions the material analyzed was extremely pure, 
as is shown in fig. 4, in which the enhedral apatites are well 
seen. it was dried at 110° prior to the analysis, which was 
carried out by the methods adopted in the previous one. 

Lorenzen (p. 30) seems to have had great difficulty, using 
Doelter’s method, in decomposing the mineral with sulphuric 
and hydrofluoric acids to determine FeO and Fe,O,. He 
reports the value FeO = 6°61 per cent in one case, but pre- 
fers to consider all the iron as ferrous in the statement of his 
analysis. Using the simple Pratt method, I had no difficulty 
in the solution of the finely powdered mineral in six minutes, 
and the result given here may be accepted as fully as correct 
as in the case of the Linosa hornblende, though the amount on 
hand did not permit of a duplicate determination. 

Special search was made for tin, as 0°26 per cent SnO, was 
reported by Lorenzen, but with absolutely negative results. 
The method adopted was essentially that of Baley as outlined 
by Classen.* The mineral powder was decomposed by evapo- 
ration to dryness with nitric and hydrofluoric acids, which 
would not lead to loss of tin by volatilization as tin fluoride is 
decomposed by heating. The residue was dissolved in hot 
dilute hydrochloric acid, filtered, and the filtrate treated with 
pure zinc, which would precipitate any tin. Only a very 
slight residue remained, which was wholly soluble in nitric 
acid. Neither this solution nor the previous filtrate gave any 
precipitate with H,S or other reaction for tin. We therefore 
consider that our hornblende contains no tin, and that the 


* A. Classen, Ausgew. Method. Anal. Chem., i, 1901, p. 184, 


198 Washington—aersutite from Linosa and Greenland. 


presence of tin, as reported by Lorenzen, is very doubtful and 
certainly cannot be considered as characteristie of the mineral, 
as suggested by him. 

Lorenzen’s original analysis and the new one are given 
below, the last two columns showing the figures of the latter 
as corrected for the 0°77 per cent of apatite present and recal- 
culated to 100 per cent, and the molecular ratios. 


I IT III IV 
SiO, .5:.. 0.5. Skeh 4188. 89-305 90-50 Sees 
iQ? Nae yee tere 6°75 10°25 10°31 “129 
SOs” Rashes 0°26 none none 
AWOL eerie. Cee 1441 9 116). 11-90 eae 
Biei@ ve eee eee none om 1°22 008 
MeO soak Os eee = 11°28 8°76 8°81 "122 
NGOs a ie, Cle 0°06 0°06 001 
INT OM reyes SG oe id Cle none none 
IMG Onsen: eee 1365) 13°24 13°31 oa 
CAO fo aan 297 MpSZ79 10°93 "195 
NiO: ee eee n. d 2°93 2°95 048 
AGAQ) ket os Sees eae 1-06 1:07 "Ol 
Fy OR amas ed ees mn. dd: 0°59 0°59 ~ -083 
POR ae ee n. d 0°32 Paes 


100°56 100°17 100°00 


I. Analysis by J. Lorenzen, Medd. Groenl., vii, p. 30, 1884. 
II. Analysis by H. 8. Washington. 3 

IIf. Analysis II corrected for apatite. 

IV. Molecular ratios of IIT. 


There is every reason for the belief that the material anal- 
yzed by Lorenzen was essentially identical with that investigated 
by us, as is also indicated by the agreement in the figures for 
Si0,, total iron as FeO, MgO, and CaO, so that the differences 
between the analyses cannot be ascribed to varying chemical 
composition. Lorenzen’s analysis is seriously defective in the 
assumption that all the iron is present in the ferrous state, as 
well as in the non-determination of soda, potash, and water. The 
last is here of comparatively small moment, but the new 
analysis shows that about four per cent of alkalies are present, 
and it is well known that all the basaltic hornblendes and 
others similar to this contain very notable amounts of soda, 
with often considerable potash, which cannot be ascribed to 
inclusions. Lorenzen’s figure for TiO, is lower than ours by 
about 3°5 per cent, while his alumina is higher by about the 
same amount. As our figure for titanium was determined by 
the colorimetric method, which is capable of a high degree of 
accuracy, and is the mean of three closely agreeing determina- 


Washington —Kaersutite from Linosa and Greenland. 199 


tions, we have great confidence in its correctness. It would 
‘seein to be highly probable, therefore, that in Lorenzen’s 
analysis part of the TiO, was reckoned as Al,O,; and this is 
the more likely as titanium was determined by him by precipi- 
tation with sodium thiosulphate, a method which is known to 
be very uncertain and apt to give either too high or too low 
results, depending on the amount of acid in the solution and 
other conditions. 

In its general features this analysis much resembles that of 
the Linosa hornblende, especially in the amounts of silica, 
alumina, magnesia, lime, and alkalies, as well as in the very 
high titanium dioxide. The only ‘prominent difference is 
found in the oxides of iron. The sum of these is considerably 
higher in the Linosa mineral and the molecular amounts are 
equal, while in the Kaersut mineral ferrous oxide is largely 
in excess of ferric, the amount of which is very low. 


Interpretation of the Analyses. 


The interpretation of the analyses of these two hornblendes 
in terms of the molecular constitution is rendered subject to 
grave uncertainty through the presence of the very large 
amounts of titanium. The uncertainty arises from the fact that 
this element may be present either as Ti,O, or as TiO, or as both 
oxides together. Potassium permanganate oxidizes Ti LOE tO 
TiO, just as it does FeO to Fe,O,, so that if the lower oxide of 
titanium is present it will appear in the ordinary course of 
analysis as FeO, the apparent amount of which would thus be 
too high, and that of Fe,O, would be correspondingly low, 
while the Ti,O, would be determined colorimetrically or gravi- 
metrically as TiO, 

If all four oxides are or may be present simultaneously, the 
analytical problem becomes complex and somewhat difficult. 
A promising line of attack is being developed by Gooch and 
Newton,* depending on the selective oxidation of the Ti,O, 
by cupric salts, bismuth oxide, or ferric sulphate, which have 
no effect on the ferrous oxide. While the results recorded are 
excellent and show the possibility of very exact estimation 
under the conditions observed, yet it is uncertain if the methods 
are applicable, at least without moditication, to the analysis of 
silicate rocks and minerals, owing to their insolubility except 
in hot hydrofluoric acid and the very ready oxidizability of 
the hot solutions of Ti,O, and FeO so obtained. It may be 
suggested that the addition of cupric sulphate to the mixture 
of hydrofluoric and sulphuric acids employed in determining 

* Gooch and Newton, this Journal, xxiii, 1907, p. 365; H. D. Newton, 


this Journal, xxv, 1908, pp. 130 and 348. See also G. Gallo, Chem. Zeitung, 
1907, p. 399, and A. Cathrein, Zeitschr. Kryst., vi, 1882, p. 248. 


200 Washington—Kaersutite from Linosa and Greenland. 


FeO might solve the problem. If under such conditions the 
eupric salt would oxidize the Ti,O, without acting on the FeO, 
titration with permanganate of two portions brought into 
solution both with and without the addition of CuSO,, 
together with the determination of total iron as Fe,O, and of 
total titanium as TiO, by the usual methods, would furnish all 
the data needed. The discover y of some such method capable 
of yielding accurate results under the conditions of silicate 
analysis 1s now one of the most important desiderata. 

In this connection a peculiarity in the relations of the oxides 
of iron and titanium may be pointed out. In whole numbers 
the molecular weights are as follows: Fe,O, = 160, FeO = 72 
ke 142), eo, 0 eo 160), Ti = 144. That 
is, neglecting the refinement of decimals, a molecule of ferric 
oxide is equal to two of titanium dioxide, and one of titanium 
sesquioxide is equal to two of ferrous oxide. Therefore, to 
oxidize either FeO to Fe,O, or Ti,O, to TiO,, one atom of 
oxygen, equivalent to one-ninth of the lower oxide, will be 
needed; while conversely, in the case of reduction of Fe,O, to 
FeO or TiO, to T:,0,, one atom of oxygen, equivalent to one- 
tenth of the weight of the higher oxide, will be subtracted. 
Exactly the same amount of potassium permanganate, there- 
fore, will oxidize the same weights of iron as ferrous oxide or 
titanium as sesquioxide to the higher form, as is expressed by 
the two equations: 


10FeSO, + K,Mn,O, + 8H,SO,=5Fe,(SO,),+ K,SO,+ 
2MnSO,+8H,0, 

5Ti,(SO,), + K,Mn,O,+ 8H,SO,=10Ti(SO,), +K,SO,+ 
2MnSO,+8H,0. 


Fe,O, and 2TiO, on the one hand, and 2FeO and Ti,O, on the 
other, are mutually interchangeable and equivalent as regards 
titration by permanganate or other such oxidizing aentg. 
From this it follows that, if Ti,O, is present and the ferrous 
iron is determined in the usual way, a percentage amount equal 
to that. of the Ti,O,-must be deducted from the apparent value 
for FeO, while an equivalent amount must be added to the 
apparent amount of Fe,O,, and deducted from that of TiO,,. 
In the case of minerals whose formulas are simple and well 
established, readjustment may be made with a fair degree of 
confidence as to probable correctness, even in the absence of 
determinations of all four oxides. Such readjustments based 
on the empirical formula would have still greater weight could 
it be assumed that ferrous oxide is absent or present in only 
negligible amounts. This consideration applies to the com- 
position of schorlomite, which we are justified in referring to 


Washington—Kaersutite from Linosa and Greenland. 201 


the garnet group as suggested by Rammelsberg* and discussed 

in detail by Koenig,+ in which enough of the apparent TiO, 

is calculated as Ti,O, to conform to the garnet formula. The 

ease of the hornblendes offers more difficulties, since their 

molecular constitution is not well understood at present, and 
is undoubtedly very complex, as is well known. 

In a recent important paper, Pentfieldt.and Stanley explain 3 
the presence of the sesquioxides by “their introduction into 
the metasilicate molecule in the form of various basic, bivalent 
radicals,” the mass effect of the very complex amphibole acid 
exerting a controlling influence on the crystal form and other 
physical characters. They also suggest the possibility that 
the molecule of the amphibole acid has a ring form, analogous 
to that of the benzene compounds. By assuming various 
bivalent radicals, composed of R,O, with F, HO, Na a, and R’, 
which combine with SiO, in the ratio of 1: lla "final residue 
of ‘Mg, Fe)O and CaO is left which conforms to the same 
metasilicate ratio. As regards tremolite and actinolite their 
exact ratios show that the molecule Na,A1,Si,O,,, suggested by 
Tschermak, cannot be present, as this would “deplete the 
total silica and destroy the 1:1 ratio.” In their calculations 
of their analyses of the aluminous hornblendes this molecule 
was also neglected, and very exact metasilicate ratios were 
obtained without the assumption of its presence. As this 
paper is the latest and one of the most suggestive and illumi- 
nating contributions to our knowledge of the constitution of the 
amphiboles, a study of our two minerals in its hght will be of 
interest. 

The two analyses made by me yield the following ratios, 
MnO and NiO being reckoned in with FeO: 


Linosa. Kaersut. 
“eee ie 5 "659 ya 
De is 106 EST e899 ee 
yA yon ‘097 } q 110 
Medias 056 { 2008 Re 
We) = 2042. Sy ee | = OES) eens 
MQ. 52 2-312 ( ihe fy aoe : 
Oa0= 25 gee ep. 17" 195 195 | 74s 
Na 0.52 032) 439 ¢ “643 048 ) 059 | 
1) oe ‘007 vee ‘O11 | ; 
BO. ee 010} 447 033 -038 
Me 


* C. Rammelsberg, Min. Chem., 1875. 
+ G. A. Koenig, Proce. Acad. Sci., Phila., 1886, p. 354. 
¢ This Journal, vol. xxiii, p. 23, 1907. 


Aw. Jour. Sci.—FourtH Series, Vou. XX VI, No. 153.—SEPTeMBER, 1908. 
15 


202 Washington—Kaersutite from Linosa and Greenland. 


In both cases the ratio of (Si, Ti)O, to (R’,, R”)O is greater 
than unity, being 1:22 in the Linosa, and 1:06 in the Kaersut 
hornblende. Such relations differ widely from those presented 
by the hornblendes analyzed by Penfield and Stanley, in which, 
where the ratio differs notably from unity, it is always on the 
side of an excess of RO over SiQ,,. 

Assuming first that all the titanium is present as the dioxide, 
if we calculate the composition of the molecules in terms of 
the bivalent radicals suggested by Penfield and Stanley, we 
obtain residues of Si0,, (Mg, Fe)O, and CaO, which differ 
widely from the metasilicate ratio Si0,: RO=1:1, in that the 
original excess of silica is here greatly accentuated. This is 
shown in the table below. 


Linosa. Kaersut. 
[(Al,-Fe),O(F, OH),] SiO,. -017 +083 
[ (Al, Fe), O,RNa, | SiO, - . ‘039 059 
GA, ite) § O ‘Ry SiO, baa en OW) 7 "026 
(Me, Fe)O a a te iii: io Ta ES 3/0 dneeee 
Ca O RCM OAE 5 Spe" Lape ee 25 i Pa, "917 451 "195 565 
residual, o1Ofs 5. 2a ere 634 600 


If, on the other hand, we assume that some of the titanium 
is present as sesquioxide, by making the necessary calculations 
and readjustments (the results of which it is needless to give 
here), we find that this will increase still more the ratio 
SiO,: RO, in spite of the reduction in the amount of RO,, 
thr ough the diminution in the amount of FeO and the taking 
up of MgO to form one of the complex radicals. We-may 
therefore assume that all the titanium is present as TiO,, as this 
shows less divergence from metasilicate ratios. 

It is therefore evident that, for our hornblendes at least, the 
presence of some other bases or radicals must be assumed, 
which will take up this seeming excess of silica and at the same 
time conform to the metasilicate ratio SiO): RO=T ty Sires 
may be found in the molecule Na(Fe, AD)Si, O,, which exists 
as the ferric or alumina extreme respectively in riebeckite and 
elaucophane, and whose presence in many amphiboles was 
suggested by T'schermak, though not found essential to the 
interpretation of the hornblendes studied by Penfield and Stan- 
ley. This, and the analogous (Mg, Fe) (Fe, Al),S81,0,,, con- 
form to the normal metasilicate ratio, owing to the trivalence 
of the basic iron and aluminum; and the molecules may be 
expressed graphically as ring for mulas, quite analogous to those 
suggested by Penfield, as is shown by that of riebeckite, as 
follows : 


Washington— Kaersutite from Linosa and Greenland. 203 


Na—O O—Na 
NSO. SiGe 
0% | | No 
O Ore Xe 
He-_Ov, | | poke 


If we assume then the presence of the bases Na,O and 
(Fe, Al),O,, which will form the metasilicates Na,SiO, and (Fe,- 
Al),Si,O, respectively, the composition of our amphiboles may 
be calculated as follows, the presence of some of Penfield’s 
radicals being needed to account for the F and H,O and the 
excess of RO, over the alkalies. The distribution can be made 
mathematically, so that the whole will conform to the meta- 
silicate formula, by the use of equations analogous to those 
used in the calculation of the norms of igneous rocks.* 


Linosa. Kaersut. 
[(Al, Fe),0,(F, OH),] SiO,. -017 033 
[fAl, Fe) O.R] Si0,..-. 088 0.26 
[(Al, Fe),0,Na,] SiO, ..--- es O44 
Na(Al, Hoyt O. eek alee "039 OLS 
(Mig, Fe) (Al, Fe),Si,0,,--. 009 es 
ue LE a enn eee aa aH i aoe A Oe en ees 
CaO ae Ss ape Pen aces eee wee ue fe eee 
Brertcar tC) se eo oo Bee i i, AOL) Leah OME, 


Assuming that the amphiboles are metasilicates, as is held 
by most authorities, and which view is greatly strenethened 
by the work of Penfield and Stanley, it is clear that the com-. 
position of the hornblendes of Linosa and Kaersut may be 
rationally explained by the assumption of the presence of mole- 
cules of the general type (R’,, R’”’) R’”’, 8i,0,,.. The presence 
of these molecules also seems to be quite unavoidable in the 
case of such amphiboles as riebeckite and glaucophane, and 
furthermore they cannot be interpreted only in terms of biva- 
lent radicals such as those suggested by Penfield and Stanley, 
though some of these may be assumed to be present. 

The two authors mentioned do not discuss the question of 
the presence of such riebeckitic molecules, an omission unhesi- 
tatingly to be ascribed to the preliminary and, most sadly, 
unfinished character of their paper. Such a discussion would 
have been inevitable had their investigation been extended to 
the glaucophanes, riebeckites, and other highly sodic amphi- 
boles, as one of us knows to have been the late Professor Pen- 
field’s intention. So far as can be learned from the published 


* Cross, Iddings, Pirsson, and Washington, Quantitative Classification of 
Igneous Rocks, Chicago, 1903, pp. 194, 195. 


204 Washington—Kaersutite from Linosa and Greenland. . 


paper their objection to the introduction of the molecule under 
discussion lay in the fact that, according to Tschermak’s theory, 
“a definite basic alumo-silicate molecule is regarded as isomor- 
phous with Ca (Fe, Mg),Si,O,,.”* As has been shown above, 
however, such a riebeckite-glaucophane molecule may be 
regar ded as a metasilicate and may be written structurally as 
a ring formula, exactly analogous to those suggested by the 
authors named. It is clear, therefore, that the presence of a 
riebeckitic molecule need not be regarded as a case of isomor- 
phism of two chemically and structurally unlike molecules, or 
as inconsistent with the views of Penfield as to the structure 
of the amphibole acid and the mass effect of complex mineral 
molecules. On the contrary, they are in complete accord, as 
the matter reduces itself, in the last analysis, to the simulta- 
neous replacement of one hydrogen atom by Na and, three by 
Fe’’, just as two atoms are replaced by Ca”, (Mg, Fe)", or by 
one of Penfield and Stanley’s bivalent radicals. 

These authors noted the highly interesting and probably 
significant fact that the CaO formed “very closely 25 per 
cent of the various radicals and bases, or in other words 
replaces one-fourth of the hydrogen atoms of the amphibole 
acid.” Without giving all the percentage figures, in the 
Linosa hornblende, as calculated above, CaO forms 33:8 per 
cent, and in that of Kaersut 26-3 per cent. The latter approx- 
imates to one-quarter, while the former is about one-third of 
the radicals and bases. If this last is substantiated by analyses 
of other hornblendes, and found to be characteristic of certain 
kinds, it might be held to indicate that the amphibole acid 
contains a number of hydrogen atoms which is divisible both 
by 4 and by 3, such as H,,8i,O,,, or a multiple of this. But 
our data are at present far too insufficient for more than a 
speculative suggestion. 

As is well known, the amphiboles which are high in soda 
and in alumina or ferric oxide, and which there is good reason 
to believe contain the riebeckite-glaucophane molecule or 
basie (Al, Fe)”, such as riebeckite, glaucophane, arfvedsonite, 
crossite, hastingsite, barkevikite, aenigmatite, and those we 
have been describing, are all intensely pleochroic and show 
either very distinctive blue colors or very intense reds and 
browns. Similarly, the pyroxenes which contain the acmite 
molecule, or basic Na’ and (Al,Fe)’’’, as aegirite, aegirite-aug- 
ite, babingtonite, ete., are deeply colored and are characteristi- 
cally pleochroic, in contrast with the common, generally 
non-pleochroic pyroxenes, which do not contain the acmite 
molecule. On the other hand, the amphiboles which contain 
trivalent Al and Fe only in bivalent radicals, on the theory of 


* Penfield and Stanley, op. cit., p. 49. 


Washington— Kaersutite from Linosa and Greenland. 205 


Penfield and Stanley, as actinolite or common hornblende, 
are less deeply colored, are never blue, and are markedly less 
pleochroic ; and the same is true of the ordinary pyroxenes and 
augites. 

Tt is commonly supposed*™ that the blue color of these 
amphiboles is connected with the presence of abundant iron, 
and Pirssont has recently suggested that the blue color is due 
to the presence of ferrous-ferric molecules, the analogy of 
Prussian blue and altered vivianite being cited. Since, how- 
ever, a similar color is characteristic of glaucophane and gas- 
taldite, in which the trivalent element is practically entirely 
aluminum, ferric iron being either absent or present in small 
amount, it would seem to be necessary to amend this hypothesis 
by assuming aluminum to replace the ferric iron either wholly 
or partially. Similarly the deep browns and reds are supposed 
to be connected with the presence of titanium and, as pointed 
out by Brégger,t the intensity of the color increases with 
increasing content in this element, as is shown by the series 
barkevikite, basaltic hornblende, and kaersutite and aenigmatite. 

We have seen above that (Al, Fe)” may enter the amphi- 
bole molecule either in a bivalent radical, such as those sug- 
gested by Penfield and Stanley, the radical as a whole acting 
as a base, or it may itself act as a base, replacing three atoms 
ot hydrogen in the amphibole acid. It would thus occupy 
different positions and perform very distinct functions in the 
molecular arrangement. In these different positions, there- 
fore, the trivalent element may reasonably be supposed to 
affect differently the optical and other physical properties of 
the minerals into which it enters, in analogy with the well- 
established fact in the chemistry of the carbon compounds. 

Following out this line of thought, it may be suggested 
that this basic (Al, Fe)’”, and not that which forms part of 
bivalent radicals, acts as a chromophore, as such color-giving 
radicals are known in organic chemistry, where they are 
especially notable among the aromatic compounds; and that, 
furthermore, the property of pleochroism may be connected 
with its presence, this either causing a mineral variety to be 
absolutely pleochroic, when varieties in which the basic triva- 
lent element is not present are not so, or intensifying the 
pleochroism of otherwise weakly- pleochroie complex mineral 
molecules. “That this chromophoric radical does not consist 
solely of (Al, F)’”, but contains Na as well, probably im the 
ratio 1: 1, is indicated by the constant presence of much soda 
in the peculiarly colored and pleochroic amphiboles and pyrox- 

*Cf. W. C. Brégger, Grorudit-Tinguait Serie, p. 35, 1894. 


+L. V. Pirsson, this Journal, vol. xxiii, p. 440, 1907. 
{ Brogger, loc. cit. 


206 Washington—Kaersutite from Linosa and Greenland. 


enes which are under discussion, as well as by the fact that 
these constituents generally show such a constant ratlo, as 
pointed out by Doelter.* The partial replacement of Na, by 
(Fe, Mg)’, sometimes observed, would harmonize this idea 
with that of Pirsson. 

The chromophoric titaniferous radical would seem to he 
more intensely active or color-producing than the alumo-ferric- 
soda one, since amphiboles high in titanium, but otherwise 
chemically like those low in this element, are red-brown 
rather than blue, as is shown by the relations of aenigmatite 
and arfvedsonite. But its nature is at present difficult to 
suggest. The ability of titanium to assume some seven states 
of oxidationt complicates the problem immensely, even though 
this possible number is lessened by considering only the oxides 
most commonly met with, Ti,0,, Ti0,, Ti0,. It may only be 
mentioned here that the violet or blue colors of solutions of 
Ti,O,, and the yellows and deep browns of those containing 
TiO,,t such as are produced from colorless TiO, solutions on 
the one hand by reduction with zine or tin, and on the other 
by the action of H,O,, may be possibly significant of the con- 
dition of oxidation of the titanium. 

The constant, characteristic pleochroism of the colored, 
common amphiboles, which do not contain the supposedly 
chromophoric Na (Al, Fe)’” radical, as contrasted with the 
equally characteristic non- pleochroism of the colored, common 
pyroxenes (free from the acmite molecule), leads also to the 
speculative suggestion that the difference is possibly connected. 
with difference in the structure of the molecule. Accepting 
provisionally the suggestion of Penfield and Stanley that the 
amphibole acid has a. closed chain or ring structure, it might 
be advanced as possible or probable, in analogy with the car- 
bon compounds, that the pyroxene acid is of the pcm chain 
type. Or the relations might be the reverse.§ 

In our present state of complete ignorance as to the sone 
tution and structure of the mineral molecules any such sug- 
gestion as is here made can but be regarded as a hypothesis 
of the most speculative character. But such a difference in 
structure would be a fundamental one between the molecules 
of the pyroxenes and the amphiboles, and it undoubtedly 
exerts a profound influence on the physical properties of iso- 
mers, as the pyroxenes and amphiboles are regarded with 
reason as being. 


*C. Doelter, Zeitschr. Kryst., vol. iv, p. 40, 1880. 

+P.) B. Browning, Introduction to the Rarer Hlements, p. 61, 1903. 

+ A. Classen, Ausgew. Methoden Anal. Chem., vol. i, p. 765, 1901. 

SIt is, of course, understood that the terms "4 open chain” and “closed 
chain” are used as they are in organic chemistry, without implying that 
they actually thus represent the structure of the molecule, or the arrange- 
ment of the atoms in space. F 


Washington—Kaersutite Srom Linosa and Greenland. 207 


It might explain the inconsistency of the apparently greater 
ehemical complexity and hence probably greater molecular | 
weight of the amphiboles, as suggested by Tschermak, and the 
higher specific gravity of the pyroxenes, which Clarke* urges 
as evidence of their greater molecular weight. It might also 
readily explain the characteristic difference in pleochroism 
between the two groups noted above. 

In this connection the analogy of the carbon compounds is 
of interest. The greater part of these are referred, as is well 
known, to two great groups; the aliphatic compounds, deriv- 
atives of methane, with an open chain type of formula; and 
the aromatic compounds, derivatives of benzene, with a closed 
chain type of formula. These two groups show characteristic 
differences in general chemical behavior, and also characteristic 
differences in some physical properties. Thus, the aliphatic 
compounds are very rarely colored, while colored compounds 
are quite common among the aromatic bodies. Similarly 
solutions of members of the first group seldom show absorp- 
tion bands, while those of the other, when colorless, often do so. 

The analogy cannot, of course, be pushed very far, but that 
such a fundamental difference in molecular structure would 
not be inconsistent with the alteration of amphibole to pyrox- 
ene, or the converse change of pyroxene to uralite, is indicated 
by the convertibility of members of the aliphatic series into 
those of the aromatic series, and vice versa. It may further- 
more be observed that very many organic compounds are 
known which contain radicals belonging to both series, such 
as toluene (methyl-benzene), ©,H,.CH,, and such pyroxenes 
as aegirite-augite might be regarded as possible analogues. 

Correlation and Name.—In the annexed table are given 
analyses of several hornblendes which resemble those of 
Linosa and Kaersut in one feature or another. In their gen- 
eral characters, on the whole, these most approach the basaltic 
hornblendes, or syntagmatites, as Rosenbush has recently pro- 
posed that these should be called,t+ especially in the figures for 
silica, iron oxides, magnesia, lime, soda, and potash. The 
alumina of our minerals is distinctly lower than in these, but 
the figures for this constituent in analyses of the syntagmatites 
(in this sense) are somewhat discordant. That shown in III 
is very high, while the analyses of Schneider run rather 
uniformly between about 14 and about 15. Also TiO, 1s 
much higher in I and II than in the syntagmatite analyses. 
The analysis (III) of a typical “ basaltic hornblende” shows 
but little TiO,, much less than in the analyses of Schneider (cf. 
IV and VI), where it varies from 4°26 to 5-40. The correct- 


*F. W. Clarke, Bull. No. 125 U. S. Geol. Surv., p. 90, 1895. 
+H. Rosenbusch, Mikr. Phys., vol. i, 2d half, 1905, p. 236. 


Washington—Kaersutite from Linosa and Greenland. 


208 


‘gop d ‘2061 ‘AIXX "Pg ‘leg “qiqer sonen “4sdyeuE 
uid  woyy ‘neueyontg avou ‘z2yVTq  ‘opuUguY 

‘poe d ‘Tegt ‘A “4st ayos}iez §—“4sATeue 
10U48190,] "BLLOT|OJUe ‘(oytyeusiuee)  o411Assop 

‘gop ‘d ‘0GgT ‘tax “yskry ‘tyosziez “ysAyeute 
S1eqsiog ‘puvfuecing ‘yIseye{neN “op tyeULsIUEW 
‘og ‘d ‘eget ‘a “Sey ur = “ysATeue 


UsZUdLOT ‘puvlusery ‘yNsIvu[plesuvy ‘ezyTUOspoasly 


01g “d ‘96ST “t ‘TeUtmmor sIqT, 
‘qgAyeue UOJSULIIV] ‘OlIejUG ‘UOUUSUNG “e}ISSUT{seH 


‘CIP F ‘O6RT ‘TAX “askayy “AT 087107 


‘qskjeue yuI,_ ‘“AVMION ‘YlLAoyIeg ‘opTylaAoyleg 
9¢.00L 1-001 61-001 08-001 19-66 79-66 
ee Ea ees GI-0 G&-0 ie 
€9-0 6&-0 1g.0 90-1 66:6 VV-1 
49-0 6<6-¢ 89.9 Cc1-8 66-6 80-9 
EP-ol 10-G 96-1 G9-P 18-6 ¥c-Ol 
69-61 98-0 6&-0 18-0 ce. 1 IL-1 
ae eee oie Sere eta amen ae ag eS 
OX) 
eine 86-1 00-T cP-0 69-0 GL-0 
66-11 L8°6& 88-9& 6V-6& 86-16 66-61 
69-11 L6-L 18-G 08-€ 69-61 81-9 
6-41 96-7 66-6 cV-V 6G- 11 cy-Il 
97-6 or LG-h Soe 6¢-1 Seas 
GV-VG GG. SV 66-LE G3-EP SIL-P& 9F-69 
IIx IX xs XI TITA ITA 


“TIX 


IL 
TITA 


TIA 
46-001 


VI-T 
1-6 
ie || 
VI-sl 


6G-P 
08-4 
Vé-V1 
14-¢ 
GL-OF 


TA 


‘ose “d ‘06ST 

T1Ax ‘shay “Iyos}iez + ‘yskTeuR dopleuyog ‘“pyeAse 
-JSe M ‘USSUTT}IBE, “(epustquasoy oryeseq) oyQeuseyusg 

‘eg “d ‘TST ‘AT “UNIT “Jed “UTI “HOSE “48Ayeue 
qplUypoS “eluULeyog “(epue[quaAoyY o1g[eseq) oyeUISE4yUAG 

“0g¢ d ‘OGST ‘tax “4shry ‘uyos}iez “ysATeue Tap 
-Teuyog “ViMmeyog “(epuelquaoy oyeseq) eyyeusRyUAG 

(OLE 78 S80] g1.0 Sepnpouy) 

‘or ‘d ‘20@L ‘MExx ‘Teurnor siqy, ‘4ysdyTeue AoTURyS 
‘eimeyog ‘UlIg ‘(epueTquaoy oTyTeseq) oy1yvUISeyUAG 
‘qskjeue WOISUIYSe A “PULTUSELyH “Wnsievy ‘o}TjNs19v yy 
‘qsX[RUB UOJSUTYSY MM “BSOUTT ‘Ossoy oJUOP “oF1gNSIEV yy 


SF-00T 99-10L 9F-00T 00-001 86-66 

ee ee Oe 8 0 ES 
ee eo CL Or ee 
Coie = 101. 86-1 0s 3209-0 Sa ee 
M76. GOL. Ol.  SGic™ = 102 

ipo Mexee Who = SED tal 
Sioa Oye ala USS etal 
aries pts rans ouou OULOG See 
Pee oe oe ee 00 S10 ee 
fi <60:0 «© Sia [en OG Chewaae wae 
Ve Gi ee 2088) gen Gel CG: 9 Gave aan 
Bo pl> O0-Gm | CG BC.1l Get Ge ay 
68:05) 0hS eo 16.0) hee ere, 
99-68 GL.68 96.68 69:68 98.0% ~~~" 

A iar IL I 


NEE 


Washington— Kaersutite from Linosa and Greenland. 209 


ness of the analyses made by Stanley under the direction of 
so preéminent an analyst as the late Professor Penfield can- 
not be doubted, and it is not probable that Schneider’s figures 
are seriously in error, especially as he states* that special atten- 
tion was paid to the determination of this constituent, though 
he does not mention the method employed. 

In passing, a few remarks may be made in regard to Nos. 
IV and V. The exact localities of these hornblendes are not 
given by either author, but they both are said to come from 
Bohemia, and the extremely close similarity in the figures for 
Si0,, Al,O,, FeO, MgO, CaO, Na,O, and K,O makes it proba- 
ble that they were made on identical amphibole from the same 
locality. In view of this remarkable agreement of the con- 
stituents mentioned, the discrepancies observed in the figures 
for TiO, and Fe,O, are noteworthy. In IV TiO, is higher 
and Fe,O, lower, while in V the reverse is true. ‘The sum of 
the two in each case is, however, exactly the same, 13°26. The 
exact agreement is, of course, a coincidence, but ‘taken in con- 
nection with the close concordance in the other constituents, 
and having regard to the methods of analysis, it suggests the 
‘explanation that in IV the ferric oxide was determined by 
reducing the iron by H,S, which does not act upon Ti0,, while 
in V the iron was reduced by zine, which would reduce the 
TiO, to Ti,O,, and the latter would appear as Fe,O,, after sub- 
traction of the FeO. On this supposition the lower TiO, of V, 
in conjunction with the close agreement between the figures 
for Al,O,, would be explained by the use of the method of 
boiling an acid solution with SO,, which is as apt to give too 
low as too high results, or even possibly by the assumption 
that the residue left on evaporation of the silica with HF is 
wholly Ti0,, a not uncommon error, especially in former days. 
The presumption therefore is that IV represents the trne com- 
position more accurately than V. The matter, after all, is of 
little importance, but serves to illustrate the need of a critical 
study of analytical data in the light of the methods of analysis. 

The blue arfvedsonitic amphiboles (IX) and the triclinic 
aenigmatite (X and XI) resemble ours in the figures for SiO, 
and K,O, and especially in the high TiO, of the Greenland 
aenigmatite. TiO, was not deter mined in the anal ysis of arfved- 
sonite and the Pantelleria cossyrite, but it is presumably present 
in both, and almost certainly very abundantly in the cossyrite, 
as Brogger has shown. Additional reasons for this belief will 
be given in a forthcoming paper on the rocks of Pantelleria. 
These hornblendes differ, however, widely from ours in the 
lower A],O,, the very much higher FeO and Na,O, and in the 
very low MgO and CaO. The recently discovered triclinic 


*C. Schneider, Zeitschr. Kryst., vol. xviii, p. 579, 1890. 


210 Washington—Kaersutite from Linosa and Greenland. 


rhénite (XII) is unique in its low silica, but in other respects 
resembles our amphiboles more than it does the triclinie aenig- 
matite, though the Al,O, is remarkably high. 

On the whole, therefore, our amphiboles may be considered 
to belong to the basaltic hornblendes or syntagmatites, rather 
than to the arfvedsonite group, and this general relationship 
is confirmed by the color, the etch figures, and the negative 
extinction angle of the Kaersut mineral. The very high TiO,, 
however, places them in a subdivision apart and, with the 
small positive extinction angle of the Linosa mineral, indicates 
a transition toward the arfvedsonite group. — 

On account of their chemical characters, and also because of 
the position of the negative extinction angles ¢ A c, barkevikite 
(VII) and hastingsite (VIII) may also be regarded as transi- 
tional between typical syntagmatite and the arfvedsonites, 
though in the direction opposite to ours. A similar relation is 
suggested by Brégger,* who regards kaersutite as an end 
member of the basaltic hornblendes. 

The name kaersutite may well be reserved for such highly 
titaniferous basaltic hornblendes or syntagmatites, and the 
mineral from Greenland may be regarded as the type. 
Whether the same name should be applied to the Linosa horn- 
blende or not is somewhat doubtful. The two are chemically 
closely similar, but show a marked divergence in the relative 
amounts of the iron oxides. Also the physical characters are 
alike in nearly all respects. The only differences of note are 
the somewhat higher specific gravity and imdices of refraction 
of the Linosa mineral, and the difference in the extinction 
angle, which last would seem to be the more important. Indeed, 
while that of the Kaersut amphibole is negative and lies well 
within the limits of the extinction angles shown by the ordi- 
nary syntagmatites, that of the Linosa amphibole is close to the 
vertical axis, but slightly positive, and indeed occupies a unique 
position between the extinctions of the riebeckite-arivedsonite 
group on the one hand and those of the syntagmatites on the 
other, though it must be remembered that in the former group 
the bisectrix which lies nearest the vertical axis is a, not c. 
The physical characters of our two minerals are tabulated 
below. 

The Linosa hornblende might be regarded as an end mem- 
ber of the highly titaniferous syntagmatites, in which case the 
name kaersutite would apply to it, or its peculiar extinction 
angle, and the high ferric oxide might justify the separation of 
it from this group as a distinct subspecies, to which the name 
linosite may be given. In view of the uncertainty of our 


* Brégger, Grorudit-Tinguait Serie, p. 35, 1894. 


We ashington—Kuersutite From Linosa and Greenland. 211 


Linosa. Kaersut. 
Specific gravity... ---- 3°336 3°137 
Crystal system __ =~ monoclinic monoclinic 
TiO rere Pe Dameot Lys aes 
CRC Onn Oe Soria ss ten D 4! =e 9! 
Optical character ------ negative negative 
Glolonmeeevees ee deep brown chestnut brown 
Ahserphions 22.2522. 22 c>b>a c>b>a 
Tie ed Siete eer ae 1°692 1°676 
eth a ee Yc es Tees 1°694 
TLS Se SRS eee 1-760 1-708 
“oe dx a 068 032 
A ea dee ae ae 79° 54’ 82° 6: 
PiGHeTSION ose ose. (?) weak (?) weak 


knowledge of the true chemical composition and relations of 
the hornblendes, the numerous varieties that are constantly 
being observed and often named, and the fact that many well- 
recognized species show greater divergence i in physical proper- 
ties and chemical composition than do our minerals, it seems to 
us advisable not to bestow a new name at present on the Linosa 
hornblende, but to consider it a kaersutite. ; 

In conclusion attention may be called to the somewhat 
remarkable coincidence between the finding of kaersutite both 
in Greenland and on Linosa, and the similar occurrence of 
aenigmatite in Greenland and the apparently identical cossy- 
rite on Pantelleria, which lies close to Linosa. In both the 
Arctic and the Mediterranean localities these minerals occur 
in comparative abundance and as material which can be easily 
studied, while elsewhere kaersutite is unknown and aenigma- 
tite very rare and the crystals small and unsatisfactory. 

Locust, New Jersey, and 


Geophysical Laboratory of the 
Carnegie Institution of Washington, D. C. 


bo 
jock 
bo 


£. Howe—Geology of the Isthmus of Panama. 


Art. XXIV.—The Geology of the Isthmus of Panama ; by 


Ernest Howe. 


Introduction. 


Tus first serious effort to investigate the geology of the 
Isthmus of Panama was made by Robert T. Hill in 1895.* 
Although his stay on the isthmus was brief and the survey 
merely a hurried reconnoissance, the principal features of the 
geology and physiography were recognized. At the time of 
his visit little or no work was being done by the French com- 
pany, few records of borings or soundings were available, and 
many exposures along recent cuts were already in the grasp of 
the jungle, so that certain details that escaped Hill remained 
to be worked out by MM. Bertrand and Zitirchert three years 
later when they made a report to the New Panama Canal 
Company. Werking under more favorable conditions, these 
geologists were able to revise certain of Hill’s views, and 
especially his conclusions concerning the igneous rocks. 

In the following pages numerous references are made to the 
reports of Hill and of Bertrand and Ziircher, from which great 
assistance has been. derived in the course of my own studies of 
the isthmian geology. 

The field work upon which the present paper is based was 
carried on during a part of the summer of 1906, and in the 
following dry season from January to April, 1907, nearly five 
months in all. The work was undertaken for the Isthmian 
Canal Commission and had to do largely with economic 
matters ; a brief outline of the geology, however, accompanied 
the report to the Canal Commission{, a résumé ‘of which has 
been published in “ Economic Geology ”.§ 

The purpose of the present paper is to record in more detail 
certain observations on the geology, and more especially on 
the stratigraphy, that affect the conclusions reached by Hill 
and the French geologists. There were unusual opportunities 
for studying the section across the isthmus because of fresh 
exposures made by recent excavation along the canal line, and 

* Robert T. Hill, The Geological History of the Isthmus of Panama and 
Portions of Costa Rica. Bull. Museum. Comp. Zool., vol. xxviii, No. 5, 
pp. 149-285. Cambridge, 1898. 

+ M. Bertrand and P. Zurcher, Etude Géologique sur l’Isthme de Panama. 
Rapport de la Commission. Compagnie Nouvelle du Canal de Panama, etc. 
Annexe I, pp. 85-120. Paris, 1899. The page references in the present 
paper are to a reprint of this report. 

+t Ernest Howe, Report on the Geology of the Canal Zone, Annual Rep. 
Isthmian Canal Commission, 1907. Appendix EH, pp. 108- 138. 


§ Isthmian Geology and the Panama ‘Canal, Economic Geology, 
vol. ii, pp. 639-658, 1907. 


EF. Howe— Geology of the Isthmus of Panama. 218 


at many places the information to be obtained from surface 
outcrops was augmented by a great number of boring records 
and samples. 

Special thanks are due Mr. John F’. Stevens, under tae 
as chief engineer the work was done, for many facilities placed 
at my disposal. !am also greatly indebted to Dr. William H. 
Dall for his kindness in looking over ee collections and for 
many valuable suggestions. 


Preliminary Statement. 


The Isthmus of Panama, where it is to be crossed by the 
canal, consists of sediments and pyroclastics of Tertiary age 
that rest on an eroded surface of andesitic breccias and associ- 
ated lava flows, all of which have been intrnded at numerous 
places, probably in Miocene time, by dikes and large cross- 
cutting masses of andesite or basalt. During the period of 
intrusion, or immediately after it, the region was uplifted, and 
the cycle of erosion thus inaugurated continued to late matu- 
rity or old age. Before the completion of the cycle, however, 
another upward movement occurred accompanied by warping 
or a gentle medial doming. Asa result of the continued ero- 
sion the basal igneous mass was exposed in the interior and a 
sub-mature topography developed in regions of harder rocks, 
while near both coasts less resistant sedimentary beds favored 
‘more active erosion and conditions of greater maturity pre- 
vailed. A third uplift cansed the streams to entrench them- 
selves in their old or mature valleys, but before this last cycle 
had advanced beyond its youth, a gradual subsidence began 
that continued until the young valleys were agegraded and ‘the 
mature valleys of the second cycle drowned for short distances 
back from the coasts. A final slight upward movement has 
elevated the estuarine deposits, formed during the period of 
depression, a few feet above sea level. 


Obispo Breccias. 


The igneous complex that appears to underlie all of the 
other formations of the isthmian region consists largely of 
andesitic tuffs and breccias; it has been given the name Obispo 
on account of its characteristic exposures at Bas Obispo, the 
northern end of the Culebra cut. From Bas Obispo south- 
ward to a point between Empire and Culebra the breccias 
have been well exposed by excavation, but at the time of exam- 
ination the zone of surface alteration had not been passed, so 
that although the rocks show their pyroclastic nature the petro- 
graphical character of the fragments and the matrix is not 
readily determinable. Fresher “material was collected on the 


214 =F. Howe—Geology of the Lsthmus of Panama. 


Pacitic side of the isthmus in the vicinity of Las Sabanas, and 
this has been compared with specimens from the other locali- 
ties which seem to be equivalent. 

The formation as a whole consists of moderately coarse 
breccias of andesite of a variety of textures but nearly uniform 
composition. Fine-grained tuffs have been observed, mostly 
on the northern side of the isthmus, while the Sabanas occur- 
rences present an extremely coarse facies. As a rule the 
breccias of the interior are composed of angular fragments 
varying from a quarter of an inch to two inches in diameter. 
Ata quarry near the Sabanas road one block more than six 
feet in diameter and many twelve or eighteen inches in diam- 
eter were observed in a cement as coarse as the average breccia 
of the interior. In a region where outcrops are few and con- 
tinuous exposures unknown it is not possible to make genera]- 
izations, but from the observed occurrences it may be said that 
the usual appearance of the Obispo breccia les between the 
extremes of coarseness and fineness that have been mentioned. 

So far as observations have been carried, the rock fragments 
composing the breccias consist largely if not entirely of 
pyroxene-andesite. Some are highly vesicular and glassy, 
others markedly porphyritic, while the majority are dense, 
even-textured rocks in which imdividual crystals can be made 
out only with the aid of a lens. In one specimen there were 
doubtful indications of hornblende. The prevailing greenish . 
gray color of the rock suggests what is found to be the case on 
microscopical examination, that the pyroxene, usually augite, 
has undergone extensive alteration; on the other hand, the 
plagioclase, which generally has a composition of about 
Ab,An,, is comparatively fresh, a fact noted in the cases of 
most of the rocks of the isthmus where the final stage in the 
decomposition to the surface red clay has not set in. 

Distribution of the Obispo breccia.—The most northerly 
occurrences of these breccias are shown by borings at the San 
Pablo dam site; from that point southward they appear occa- 
sionally at the surface, and are indicated in all the borings 
made at intervals of one kilometer along the center line of the 
canal as far as Empire. Decomposed but otherwise character- 
istic exposures are to be seen between Mamei and Gorgona 
along the Panama Railroad, and from Gorgona to Empire, 
where they disappear beneath a cover of later sediments, the 
Obispo breccias are the prevailing rocks. Composing the hills 
north, west, and east of Corozal, and particularly well exposed 
northeast of Panama in the vicinity of Las Sabanas, are rocks 
of the same petrographical character that are believed to be a 
part of the central mass. : 


FE. Howe— Geology of the Isthmus of Panama. 215 


Age of the Obispo breccias.—The only definite statement 
that can be made in regard to the age of the Obispo breccias 
is that they are older than the oldest sedimentar y rocks of the 
region, which, as will be shown presently, carry a fauna consid- 
ered by Prof. “William H. Dall to correspond to the Claiborne 
Eocene. Although it is not improbable that the eruption of 
these andesitic breccias marked the beginning of Tertiary his- 
tory in the isthmian region, there is no direct evidence that the 
rocks are not still older. 

MM. Bertrand and Ziircher* included with the breccias that 
have been described as the Obispo, certain other fragmental 
igneous rocks exposed near Bohio, calling the whole ‘ Roche 
de Gamboa.” From fossil evidence found at Bohio they corre- 
lated the Gamboa rock with the Oligocene of southern Europe. 
Reasons are given in a later paragraph for believing that the 
breccias at Bohio are intimately associated with the oldest sedi- 
mentary rocks and separated from the Obispo breccias by an 
unconformity. 


Bohio Formation. 


The name Bohio is proposed for the oldest sedimentary for- 
mation recognized on the isthmus and includes cer tain beds 
occurring at Bohio, Vamos Vamos, and in the vicinity of Gatun. 
This name is suggested | in order to avoid confusion in referring 
to the same rocks described by Hill and Bertrand, but not ree- 
ognized by them as being parts of one formation. 

What are believed to be the lowest beds of this formation 
are conglomerates exposed in the lock site partly excavated by 
the French near Bohio, and breccias in the quarries at the 
Bohio railway station. A mile and a half to the west, ata 
locality known as Vamos Vamos, rocks of the same age are 
exposed on the south bank of the French canal, and similar 
rocks, although no fossils have been found among them, occur 
along the Panama Railroad near Tiger Hill. On the west 
bank of the canal nearly opposite the mouth of the Gatuncillo 
the formation is again exposed and the beds carry abundant 
fossils. At intermediate points borings have shown the pres- 
ence of rocks lithologically the same as those at Vamos Vamos 
or near Gatun, but their few fossils have been indeterminable. 
To the southeast of Bohio borings in the vicinity of Buena 
Vista and San Pablo have indicated the presence of beds like 
those at Bohio, while a few isolated patches of conglomerate 
that rest on the Obispo breccias in the neighborhood of Mamei, 
Gorgona, and Matachin, are in all probability a part of the 
Bohio formation. 

* Etude Géologique sur L’Isthme de Panama, p. 5. 


216 F. Howe—Geology of the Isthmus of Panama. 


—Lithologic character of the Bohio rocks.—ULack of contin- 
uous outerops and sudden changes in the character of the beds 
within short distances have prevented an altogether satisfactory 
study of the Bohio formation. Boring records have assisted 
at a number of places, but even with their help the relations — 
at Bohio are not easy to make out. 

Directly south of the village of Bohio on the opposite side of 
the river is a hill about seventy-five feet in elevation, through 
the middle of which a cut was made by the French for the 
construction of a lock. The sides of the cut are now more or 
less covered by vegetation but still present excellent exposures 
of the rocks composing the hill. The section shown is about 
fifty feet in thickness and consists of beds of coarse conglom- 
erates, gravels, and sands that strike N. 25° E. and dip about 
14° to the northwest. Crossbedding is common and the beds 
of finer textured rocks are frequently lenticular. The con- 
glomerates contain many bowlders a foot or more in diameter 
associated with coarse gravel or cobbles and held in a gritty 
matrix that is of the same character as the beds of finer sand- 
stone. The bowlders are of a number of kinds of eruptive 
rock, the commonest being hornblende-andesites with less 
abundant hornblende augite-andesite, augite-andesite and latite 
porphyry ; nearly all are coarse-grained and strongly porphy- 
ritic. It is noteworthy that of the bowlders examined few 
resembled rocks observed in other parts of the isthmus. The 
matrix in which these bowlders lie and the associated sandstones 
are composed of finer debris of the same rocks; quartz is so 
rarely present as to be negligible. It is worth noting in this 
connection that the bowlders of the conglomerate are of com- 
paratively fresh rock while the matrix and intercalated sand- 
stones are invariably decomposed, the alteration being to a 
complex aggregation of epidote, serpentine, kaolinite and seri- 
cite that causes the rocks to have a distinctly soapy feel. This 
is a feature common to most of the fragmental rocks not of 
direct voleanic origin, wherever alteration has not progressed 
so far as to result in the formation of the surface red clays. 

Not more than a quarter of a mile north of the conglom- 
erates exposed at the Bohio lock site, outcrops of a peculiar 
greenish brown rock are to be seen on the right bank of the 
Chagres beneath the village of Bohio. The hills to the north 
and east are composed of the same rock, and just back of the 
village, quarries are locateu from which building stone has 
been obtained for the Panama Railroad bridge piers and other 
purposes. The quarrying operations have exposed a vertical 
section of the rock about fifty feet thick. The rock is com- 
posed of fragmental materials of voleanic origin; the imbedded 
fragments are largely of pyroxene-andesite of a number of dif- 


EF. Howe— Geology of the Isthmus of Panama. 217 


ferent textures, often fluidal and glassy, and varying from a 
tenth of an inch to one or two inches in diameter. Although 
many of the fragments are comparatively fresh, the matrix or 
cement is in an advanced state of decomposition, the second- 
ary minerals being zoisite, epidote, serpentine, and some doubt- 
ful kaolinite. As a whole, however, the rock is so extremely 
altered that it is difficult to determine whether it is a simple 
voleanic breccia ike the Obispo or a fine conglomerate of vol- 
eanie debris like that at the near-by lock site. So far as it is 
possible to make out, I am inclined to believe that it is a vol- 
eanic breccia, in the sense that it is more or less of eruptive 
origin, largely on account of the uniform character of the 
rock fragments composing it as contrasted with the varied pet- 
rographie character of the bowlders in the conglomerate at 
the lock site. It is not impossible that the breccia represents 
a “volcanic mud-flow” as suggested by Bertrand.* 

The particular interest attaching to this breccia is its inti- 
mate association with the conglomerates exposed at the lock 
site. This relation is not shown on the surface, but is brought 
out very clearly by borings made in exploring possible dam 
sites in the vicinity. One series of these borings, along what 
is known in the surveys as the “}’” line, extended from the 
quarries at Bohio in a southerly direction across the river to 
the hill through which the French excavated the lock site, a 
distance of about one-half mile. At the northern and southern 
ends of this line respectively characteristic specimens of the 
breccia and of the conglomerate were obtained by the drill, 
while at intermediate points transitional facies were shown in 
nearly all the borings. Among other features is the associ- 
ation of the typical breccia of the quarry with water-laid sand- 
stones or tuffs, many of which contain carbonaceous matter, 
while others, coarser grained, are composed of distinctly water- 
worn material and are held in a caleareous cement. Passing 
southward the breccias become less and less abundant while 
the water-worn material increases in coarseness and conglomer- 
atic beds are to be noted in many of the holes. Layers of fine 
material interbedded with both the typical breccia and with 
the coarse conglomerates, as at the French lock site, are shown 
in practically all the borings. 

The lowest point reached by the drills was about 194 feet 
below sea level near the middle of the line of borings. After 
passing through alluvium filling the;Pleistocene valley of the 
Chagres, the deepest boring entered about thirty feet of coarse 
conglomerate; the matrix holding the bowlders was ground up 
by the drill and none is shown in the samples collected, but 


* Op. cit., p. 5. 


Am. Journ. Sct.—FourtTH Series, VoL. XXVI, No. 153.—SzupremsBer, 1908. 
16 


218 LL. Howe—Geology of the Isthmus of Panama. 


the presence of certain porphyritic rocks closely resembling 
those contained in the conglomerate of the lock site makes me 
believe that this is to be regarded as a conglomerate rather 
than as a breccia like that of the quarry where little or no vari- 
ation in the eharacter of the fragments of pyroxene-andesite 
was found. One hundred feet south of this point another 
boring passed through fine sandstones or tuffs before striking 
beds similar to those in the previous hole and at a correspond- 
ing elevation. About the same distance to the north from the 
first hole and at the same elevation, fine-grained beds like those 
of the second hole are also shown by the core, while still nearer 
the quarries and at an interval again of about one hundred feet 
fine material mixed with angular fragments of pyroxene and 
andesite is shown. In the opposite direction a corresponding 
change to the conglomerate facies is to be observed. Precisely 
the same transition is shown by a line of borings made from 
the hill in which the French lock site was excavated in a north- 
easterly direction across the valley of the Chagres to the hills 
east of Bohio. : 

This evidence would seem to indicate that the breccias, best 
shown at the quarries, were deposited contemporaneously with 
the conglomerates and sandstones of the lock site. The breccias 
were in large part, if not entirely, laid down in water, and prob- 
ably running water, but it is impossible to decide whether the 
material composing the breccia was transported for some dis- 
tance by streams before being deposited or if it fell into the 
water directly from the air. The angular character of the 
fragments, so far as it may be determined in the extremely 
decomposed rock, would seem to favor the direct deposition of 
the breccia in water as a result of voleanic eruption. Eruptions 
of fragmental material of uniform composition undoubtedly 
took place during this first period sedimentation, and evidence 
for this has been found at other points, especially in the vicin- 
ity of Culebra, as stated in a later paragraph. 

Southeast of Bohio the character and distribution of the 
conglomerates and breccias are imperfectly known. Near San 
Pablo rocks similar to the Bohio breccias are indicated by bor- 
ings beneath acid tuffs, while it is more than probable that the 
Bohio beds are represented in the neighborhood of Gorgona 
by conglomerates exposed along the line of the Panama Rail- 
road. In most instances it is all but impossible to distinguish 
between the conglomerates and the volcanic breccias upon 
which they rest because of the extreme decomposition that 
both have suffered. The occurrences at Gorgona are fresher, 
however, and their conglomeratic character unmistakable. 
The andesitic breccias beneath these conglomerates belong to 
the Obispo formation and have been traced by borings practi- 


FE. Howe—Geology of the Isthmus of Panama. 219 


eally all the way from near San Pablo to the type locality at 
Bas Obispo. Hill noted the presence of these conglomerates 
at the places named and correlated them with the beds at the 
Bohio lock site.* 

Vamos Vamos and Gatun beds——-About two and a 
half miles west of Bohio, on the south bank of the French 
canal, at a locality known as Vamos Vamos, are exposures of 
sedimentar y rock that have been described by Hillt and Ber- 
trand.{ The rocks are impure calcareous shales or marls of a 
dirty brown color, rich in fossils, and at certain horizons con- 
tain numerous lar; ge fossiliferous ‘calcareous concretions that at 
first suggest bowlders in a conglomerate. 

Following the line of the French canal northwest for nearly 
six miles, no outcrops of any sort are to be seen until within a 
short distance of Gatun, where, on the left bank of the canal, 
are exposures of extremely fossiliferous marls and calcareous 
sandstones. Similar beds are exposed along the cuttings of 
the Panama Railroad through Tiger Hill between Bohio and 
Gatun. No other exposures in this region are known, but a 
great number of borings made at Gatun in exploration of dam 
and lock sites furnish much valuable imformation in regard to 
the character of the rocks. The samples of borings from the 
lowest sedimentary rocks at Gatun are all of extremely fine- 
grained, even-textured sandstones which in some places merge 
into sandy shales. The cementing material is usually calca- 
reous, but considerable earthy impurity or clay is often present. 
The coarser components of the rock at Gatun and of that occur- 
ring along the canal between Gatun and Bohio consist of 
igneous material; in many specimens grains of nearly fresh 
feldspar and ferro-magnesian silicates may be recognized, but 
as a rule the material is in such a finely divided state that it is 
impossible to say whether it is of direct voleanic origin or has 
resulted from the degradation of older igneous rocks. At 
many points fossils are abundant in the core specimens and 
carbonaceous matter is very generally present. 

Age of the Bohio formation.—From fossils collected by 
Hill and others and by myself and examined by Dr. William 
H. Dall, it appears that the beds described are of Eocene age 
and contain a number of species typical of the Claiborne and 
some common to the Upper Tejon of California.§ In the 
material that I collected at Vamos Vamos Dall has identified 
the following species : 

* Op. cit., 188. { Op. cit., p. 179. t Op. cit., p. 6. 

§ Hill, op. cit., Part VI, Report by Dr. William H. Dall upon the Paleon- 
tology of the collections, pp. 271-275. 


220 #. Howe—Geology of the [sthmus of Panama. 
Lupia perovata Cony, Cytherea 
Glyptostyla panamensis Dall. Mactra 
Turritella gatunensis Conr. Corbula 
Marginella sp. Tellina 
Natica (cf. eminula Conr. ) Leda sp. 
Pleurostoma sp. Pyramidella sp. 


Dentalium sp. 


In addition to these there are fragments of Ostrea sp., Liocar- 
dium, and Pecten, and a small ribbed Cardium was noted. 

From the locality on the left bank of the canal near Gatun 
practically the same fossils were collected as were found at: 
Vamos Vamos with the addition of a Cadulus. 

There can be no doubt that the rocks at Vamos Vamos, near 
Gatun, and at intermediate points as shown by borings, belong 
to the same formation, and they have been so regarded by 
Hill and Bertrand. The relation of these rocks, however, to 
the peculiar breccias and conglomerates at Bohio is not so 
clearly shown. Bertrand considers that the breccias at Bohio 
belong to the same series as those occurring in the central part 
of the isthmus which I have described as the Obispo formation, 
and he correlates them with the European Tongrian, that is, 
the base of the Oligocene in the Paris Basin.section. This 
determination is .based on fossils obtained from a boring at 
Kilometer 24°36. Here, according to Bertrand,* small num- 
mulites of the Oligocene type are associated with Orbztordes 
that appear to be the same as those of the Pefia Blanca marls 
(to be described later). The breccia, a part of the ‘“‘ Gamboa 
rock,” is regarded, therefore, as certainly Oligocene and prob- 
ably Aquitanian. In the geological profile accompanying 
Bertrand’s report a special tint is given to the breccias, in order 
to accentuate the difference between these beds and the higher _ 
series, and they are referred tentatively to the Tongrian. 

Hill appears to regard the breccia and perhaps the conglom- 
erates at the French lock site as parts of an early igneous forma- 
tion older than the Vamos Vamos beds. My own observations 
make me believe that the conglomerates at the lock site repre- 
sent the lowest portion of the formation of which the Vamos 
Vamos beds and those in the vicinity of Gatun are the upper 
parts. This opinion is in accord with the local structure, the 
prevailing dip of the conglomerates, about 15 degrees to the 
northwest, being sufficient to carry them below the beds at 
Vamos Vamos. From a boring made by the Canal Commission 
at the Bohio lock site (Hole 24-b, K 24), fossils were obtained 
at elevations of from 20 to 40 feet below sea level that are 
believed by Doctor Dall to represent an Eocene horizon. 
They consist of fragments of Lucona, Lima, Pecten, Cardium, 


SOD iCih., ero. 


£. Howe—Geology of the Isthmus of Panama. 221 


Protocardia, and Ostrea, a small Fusus (2), a specimen of Or- 
bulina, and a Melanian (2) associated with abundant fragmentary 
plant remains. The abundance of carbonaceous material and 
the presence of the fresh-water Melanian within a few feet 
vertically of the salt or brackish water species suggest delta 
deposits, and with this the physical character of the beds agrees 
pertectly, the fossils being preserved in calcareous sandstones 
or shales between beds of conglomerate precisely as are those 
exposed at the cutting for the locksite. Before reaching these 
fossiliferous layers the drill passed through a fine breccia like 
that shown at the quarries at Bohio, interbedded with which 
are fine-grained sandy layers containing plant remains. Con- 
glomerates like those of the lock site were found below this 
breccia, then at about twelve feet below sea level a fine car- 
bonaceous sandstone layer was encountered, and below this the 
fossiliferous sandstones. ; 

On the strength of this evidence I am inclined to regard the 
conglomerates and breccias at Bohio as members, probably | 
occurring near the base, of the formation that I have called 
the Bohio, and that they were laid down as delta deposits at 
the mouth of a large river, while the Vamos Vamos beds and 
those near Gatun were deposited contemporaneously in deeper 
water. It is entirely possible, of course, that the conglomerates 
may belong to an earlier epoch than the Claiborne, but the 
evidence for or against this is so meagre that in the absence of 
anything to the contrary it seems entirely reasonable to place 
the conglomerates at the base of the Claibornian Bohio forma- 
tion. No one can doubt the intimate relation between the 
conglomerates and the breccias nor that they are contempora- 
neous. It has been shown also that the conglomerate occur- 
ring in patches near Mamei and Gorgona rests unconformably 
upon the breccias of the Obispo formation. For this reason 
and as is also shown in the case of the Culebra beds, I believe 
that the Bohio rocks with their breccias are younger than the 
breccias of the Obispo formation instead of being a part of 
them as suggested by Bertrand. 

Thickness of the Bohio Formation.—Of the thickness of 
the Bohio formation very little can be said. Borings on the 
“TF” line at the Bohio dam site have brought up samples of 
the conglomerate, sandstone and breccia from nearly 200 feet 
below sea level, while at least 75 feet more may be added to 
this as exposed above sea level in the near-by hills. From 
Bohio to Gatun, where the Bohio formation is covered by 
younger beds, the distance is about seven miles in a straight 
line; assuming a uniform dip of only two degrees to the north- 
west, this would give at Gatun a thickness of nearly 1300 feet. 
At least 300 feet of the section has been shown in borings at 
Gatun. 


222 . Howe—Geology of the Isthmus of Panama. 


Culebra Beds. 


From near Empire to Pedro Miguel, a distance of about five 
miles along the line of the canal through the Culebra cut, are 
the best exposures of sedimentary rocks in the Canal Zone. 
The Obispo formation has been uncovered by excavation from 
Bas Obispo to a point about midway between Empire and 
Culebra, where it disappears beneath the sediments described 
by Hill and others as the Culebra beds. A considerable thick- 
ness of these beds has been exposed in the deepest. part of the 
cut, beneath which borings have shown that they extend to at 
least 40 feet below sea level. A boring at Kilometer 55 passed 
through 207 feet of Culebra shales and sandstones without 
reaching the base of the formation. Nearly 175 feet should 
be added to this section as representing the part already 
removed from the canal prism at the point where the boring 
was made. This.would give an observed thickness of nearly 
400 feet. Hill estimated the thickness as at least 500 feet* 
and the total is probably greater rather than less. 

So far as they have been exposed or explored by borings the 
rocks are found to be largely soft shales with abundant sandy, 
conglomeratic, and calcareous layers. At many horizons lentic- 
ular bodies of limestone occur. Although there are some thick 
beds of homogeneous pure clay shales, the majority of the 
rocks, whether sandstones, shales or conglomerates, are richly 
carbonaceous; lens-like seams of lignite have been found at 
many places in the cut and remains of trees and plants are 
abundant. The sandstones are impregnated with lime and in 
the coarser varieties of the rock films of the cementing calcite 
are readily visible. The conglomerates are composed of sub- 
angular rock fragments less than a quarter of an inch in 
diameter held in an impure calcareous matrix. The material 
of which all of the sedimentary Culebra beds are composed 
was derived from an older igneous land mass of which presum- 
ably the Obispo breccia was a part; quartz is notably absent 
and the colors range from bluish and greenish gray to nearly 
black in the richly carbonaceous beds. 

In the upper part of the section at a number of places along 
the canal cut between Empire and Paraiso are extensive occur- 
rences of andesitic breccias. Petrographically the fragments 
composing them closely resemble those of the Obispo breccia, 
but they are smaller and more uniform in size than those of 
the Obispo breccias of the same region. In the central area 
near Culebra summit these breccias are seen to rest upon the 
shales or fine sandstones of the Culebra beds. At the same 
locality there are numerous intrusive masses of basalt, and 


* Op. cit., p. 198. 


EF. Howe— Geology of the Isthmus of Panama. 228 


faulting and considerable folding have taken place so that the 
relations of the various rocks are not perfectly clear. There 
ean be no question, however, that the breccias are a part of 
the upper Culebra beds, for in several places a simple sedimen- 
tary contact between the two kinds of rock was observed, and 
it was even possible to collect hand specimens showing the 
transition from fine shales to the breccia. The breccias are at 
many places cemented by calcite of secondary origin. Speci- 
mens collected at Gold Hill (Cerro Culebra) and Paraiso, 
although considerably decomposed, may be recognized as made 
up of fragments of pyroxene-andesite of different textures, 
some of which have an abundant glassy groundmass. A boring 
near Paraiso (Kilometer 58) showed similar rocks at several 
horizons, while interstratified with them were other beds of 
sediments exactly like those in the lower or main part of the 
Culebra section. It would appear, therefore, that toward the 
close of Culebra sedimentation volcanic eruptions took place 
and that the ejectamenta were laid down conformably on the 
sediments; a number of such eruptions evidently occurred 
with intervals of quiescence, during which the deposition of the 
sediments continued. The association of these breccias with 
the Culebra sedimentary beds corresponds closely with that 
of the Bohio breccias and conglomerates with the exception 
that the Culebra breccias appear in the upper part of the sec- 
tion while those at Bohio seem to be near the base. Unfortu- 
nately the state of decomposition of the Bohio rocks prevents 
satisfactory petrographical comparison between the two brec- 
cias. In neither case does it seem possible to separate the 
breccias from the sediments as distinct igneous formations. 
The relation of the Culebra sediments to the Obispo forma- 
tion is more definitely shown than the Bohio rocks to the 
Obispo on the Caribbean side of the isthmus. At the surface 
the relations are not always clear, but it is possible by means of 
borings made at frequent intervals to trace the Obispo breccias 
from Bas Obispo soutb to a point near Empire, where they 
suddenly pitch in a southeast direction beneath the rapidly 
thickening cover of the Culebra beds. There is a moderate 
amount of local folding and faulting in the region and the 
Culebra beds have a prevailing dip to the southeast, but their 
inclination is much less than that of the southeasterly pitching 
surface of the Obispo on which they rest. Near Corozal the 
Obispo again appears at the surface, while between Corozal 
and La Boca borings have shown that there are present, 
beneath the alluvium, sandy shales precisely like many found 
in the Culebra section. As mentioned later in discussing the 
age of the Culebra beds, certain limestones that are thought 
to belong to the upper part of the shale series rest on the 


224 LE. Howe —Geology of the Isthmus of Panama. 


Obispo breccias near Empire. The evidence between Culebra 
and Empire, at Corozal, and in the vicinity of La Boca seems 
to indicate that an unconformity exists at the top of the Obispo 
separating it from the Culebra beds. As has been shown, - 
similar unconformable relations appear to exist between the 
Obispo and Bohio formations on the Atlantic slope. 

Limpire lumestone.—Hill noted an occurrence of massive, 
semi crystalline limestone near Empire and from its relations 
in the field referred it to the Culebra beds.* I am not certain 
that [ identified Hill’s exact locality, but I did succeed in find- 
ing limestone of precisely the same character in the vicinity of 
the railway station at Empire on both the east and west sides 
of the track. Fifty feet east of the new station there are 
exposures, about ten feet thick, of a very massive cream-col- 
ored limestone in which I was unable to discover fossils; the 
outcrop is a small one and its relation to other rocks in the 
vicinity is not shown. About 150 yards west of this locality 
on the opposite side of the railway a greenish, impure sandy 
limestone, hard and compact, occurs beneath thin-bedded ‘eal- 
careous shales and sandstones, the whole exposure being less 
than ten feet thick. F ragments of a FPecten were found in 
this limestone but no determinable fossils. There are no 
exposures between these outcrops and the canal cut about one 
quarter of a mile to the northeast, at which point the Obispo 
formation is found close to where it disappears beneath the 
Culebra beds. 

Elsewhere in the Culebra section lenticular bodies of lime- 
stone, less thick than the massive rock at Empire but other- 
wise of the same character, are found associated with the eal- 
careous shales and sandstones, and it seems reasonable, as Hill 
has suggested, to regard the Empire occurrences as of this 
nature and belonging to the Culebra beds. The field rela- 
tions, such as they are, appear to indicate that rocks of the 
Obispo igneous formation must lie within a few feet of the 
surface in the neighborhood of Empire, and it is not impossible 
that the limestone may rest directly upon them. 

About midway between Empire and Las Cascadas on the 
Panama Railroad other limestones occur. They are less mas- 
sive than those at Empire, in places gnarly and crumbling, and 
being practically at the surface where exposed in the railway 
cut are considerably weathered. Their color is buff or yellow- 
ish pink. The few fossils from this locality are poorly pre- 
served and indeterminable, according to Dr. Dall, but he 
recognized a nullipore and two species of Pecten and suggests 
that this may be a reef deposit. 


=Op7 cit... p: 19a: 


EF. Howe— Geology of the Isthmus of Panama. — 225 


Nearer Las Cascadas bowlder-like concretionary masses of 
hard crystalline limestone, one to four feet in length, are pre- 
served in red clays of decomposition near the railway and 
eanal. Fragments of a Pecten and a tube-like XYylotrya were 
collected from one of these limestones but their age could not 
be determined. 

Age of the Culebra beds.—Hill made a careful study of the 
Culebra beds, but only succeeded in finding fossils in the 
Empire limestone, mostly foraminifera that Bagge considered . 
representative of the Eocene, and as quoted in Hill’s report, 
he correlated this limestone with the Pefia Blanca marl.* In 
material that I collected in the vicinity of Las Cascadas from 
rocks that I believed to belong to the same calcareous horizons 
as the Empire limestone, Dr. Dall failed to find any species 
from which the age ot these beds could be determined. Ber- 
trand and Zircher, however, collected from the same localities 
and their material was determined by Douvillé as representing 
the Burdigalian Miocene, or the equivalent of the beds exposed 
at Kilometer 10 near Gatun.t The French geologists regarded 
the Empire limestone as belonging to the upper part of the 
Culebra beds and equivalent to the Vamos Vamos beds of the 
Caribbean slope. In the vicinity of Pedro Miguel Bertrand 
and Zurcher found fossils that were correlated with those from 
Las Cascadas. Fossils from my collection at the same locality 
were determined by Dr. Dall as probably representing an 
Oligocene reef deposit, while beneath them a typical Claiborne 
fauna was found in a compact impure limestone. _ 

It is probable that the Claiborne horizon at Pedro Miguel is 
the one that Bertrand and Zircher correlate with the beds at 
Las Cascadas, since the fauna of both is regarded by them as 
identical with that preserved at Kilometer 10 near Gatun. It 
is in collections from the Gatun locality made by Hill and 
myself that Dall finds his most typical Claiborne fossils. At 
both Pedro Miguel and Las Cascadas the position of the fos- 
siliferous beds appears to be at or very near the top of the 
Culebra section, and in the absence of determinable fossils from 
lower horizons it seems reasonable to refer the Culebra beds as 
a whole to the same period as that in which the Bohio forma- 
tion was deposited. The abundance of carbonaceous shales, 
seams of lignite and plant remains, together with fragments of 
a melanian found in the canal eut near Culebra, suggest that 
most of the beds below the limestone horizons were deposited 
in fresh water. 

Limestones of the Upper Chagres.—Following the Chagres 
headward in a northeasterly direction from Matachin, where 
the river. turns sharply to the northwest and flows toward the 


= Op..cit... po ries aba. + Op. cit., pp. 6-9. 


226 #. Howe—Geology of the Isthmus of Panama. 


Caribbean, calcareous rocks similar to those near Las Cascadas 
and Empire are exposed at many places between Cruces and 
Dos Bocas, a distance in a straight line of about twelve miles. 
Between Oruces and Palo Grande compact limestone similar to 
that at Empire rests on carbonaceous shales like many in the 
Culebra beds. The rock is partly crystalline and contains in 
places fragments of shells. About one mile above the mouth 
of the Chilibre is the lower end of a winding gorge through 
-which the Chagres flows for nearly twelve miles, the entrance 
to the gorge being a mile below Dos Bocas. The river, 
entrenching itself in an old valley, encountered between the 
points mentioned limestones and calcareous sandstones which 
offered greater resistance to erosion than the rocks to the north- 
east and southwest, so that its former meandering course has 
been preserved very perfectly, and at the outside curves of the 
meanders are nearly vertical cliff exposures of massive cal- 
careous sandstone and limestone, in places more than one hun- 
dred and fifty feet high. Although the length of the gorge 
following the river is approximately twelve miles, the belt of 
hard rocks traversed is only about four miles wide. 

The rocks are all of a light cream or buff color and range 
from partly crystalline limestones to coarsely granular rocks 
composed of broken shells, sands, specks of magnetite and 
occasional pebbles of igneous rocks held in a calcareous cement. 
Certain layers are well bedded, others massive, while cross- 
bedding is not uncommon. Fossils, Ostrea and Pecten, are 
abundant, but I was unable to find any determinable species ; 
at a locality about a mile below. Alhajuela a bed composed of 
broken corals and fragments of molluscan shells was found. 

The similarity of some of these rocks and their fossils with 
those observed near Las Cascadas is striking, and Bertrand and 
Zurcher regarded the two occurrences as of the same age.* I 
agree with this opinion in so far as the Chagres and Las Cas- 
cadas beds are correlated with the fossiliferous rocks exposed 
by the canal at Kilometer 10 near Gatun, whose fauna, as has 
been said, Dall considers Claiborne Eocene ; the French geolo- 
gists have compared the Chagres rocks with beds near Mar- 
seilles that grade from Upper Oligocene to Miocene. Bertrand 
states, on the authority of M. Boutan,t that the limestone 
near Dos Bocas resembles in part certain marls occurring at 
Pefia Blanca, and that it contains foraminifera. I am not pre- 
pared to say that this is not the case, but the structure of these 
beds as noted both by Bertrand and myself would carry them 
beneath the limestones of the gorge, and they should corre- 
spond closely in position to the “limestones observed near 
Cruces and therefore be comparable to the Empire limestone. 


*~ Op» cit:, pao: + Op. cit,/p, 10: 


E.. Howe— Geology of the Isthmus of Panama. — 227 


Martius oF PeNa BLAnca. 
(Lower Oligocene.) 


Less than a quarter of a mile west of the railway station 
and quarries at Bohio at the base of a low hill are outcrops of 
a hard, light yellowish marl. A quarter of a mile still farther 
west the same rock has been exposed in excavations for a 
diversion channel made by the French. The rock as a whole 
may be described as a thick-bedded marl, buff to cream-colored, 
and containing foraminifera in greater or less abundance, the 
most typical being Orbitordes fortist. Sparsely disseminated 
through the rock are minute specks of a dark silicate and frag- 
ments of feldspar. So far as is known, the only occurrences of 
this rock are at the localities mentioned between Bohio and 
Pefia Blanea. 

Nowhere in the vicinity of Bohio was I able to discover the 
relation of the Pefia Blanca rock to the Bohio conglomerate or 
breccia, nor is any direct evidence found in the borings, but 
from the general field relations it would seem that the marls 
are younger than the breccias, since less than half a mile east 
of the marls borings have indicated the presence of the brec- 
cias and conglomerates many feet below the observed elevation 
of the marls, while as shown at the lock site exposures, the 
Bohio rocks dip about fifteen degrees in the the direction of the 
marls. Unless a fault of considerable magnitude occurs — 
between the two localities, of which there is no evidence, the 
marls cannot be older than the Bohio beds, nor is there any 
indication that they were contemporaneous deposits, borings 
between Pefia Blanca and Vamos Vamos having passed 
through rocks of the Vamos Vamos facies of the Bohio alone. 
Hill states* that he found the foraminiferal marls in uncom- 
formable contact with the conglomerates at a locality known as 
Pefia Negra, one mile below Bohio. I was unable to identify 
this point, but Hill’s observation is in entire accord with my 
opinion that the foraminiferal beds of Pefia Blanca rest uncom- 
formably on the rocks of the Bohio formation. 

Hill regarded the Pefia Blanca beds as older than the Vamos 
Vamos, basing his opinion on the northwest dip of the Vamos 
Vamos beds and the position of the foraminiferal marls south- 
east of them. I have shown, however, that in all probability 
the Vamos Vamos beds and the Bohio conglomerates belong 
to the same formation, and the discordance between the Pefia 
Blanca and Vamos Vamos beds is to be considered as another 
manifestation of the same unconformity observed by Hill at 
Pefia Negra. This view agrees with Dr. Dall’s opinion that the 
Pefia Blanca marls, on account of the presence of the charac- 


* Op. cit., pp. 178-179. 


228 = EE. Howe—Geology of the Isthmus of Panama. 


teristic species Orbetordes fortis, are of Lower Oligocene age 
corresponding to the Vicksburg. | 


Monkey Hitt Formation. 
(Upper Oligocene.) 


Between Gatun and the coast at Colon is a more or less hilly 
region in which numerous exposures may be found along the 
lines of the Panama Railroad and the French canal. Fossils 
collected from the rocks at these points indicate that all of the 
beds are of the same age. ‘The rocks are well stratified, often 
thin bedded, calcareous sandstones, argillaceous sandstones, 
marls and shales, usually fine grained and even-textured, and 
when fresh of a neutral bluish or greenish gray color. They 
belong to what Hill called the Monkey Hill beds,* the best 
exposures at the time of his visit being near the Panama Rail- 
road where it passes through the hills. At the time of my 
examination by far the best exposures were at Gatun, where 
extensive excavation had been made for the locks. At this 
point also it is believed that the base of the formation is shown. 
In order to avoid ambiguity these beds will be referred to as 
the Monkey Hill formation, as they were so described by Hill, 
although in my report to the Canal Commission they were 
spoken of as the Gatun beds, since they made up a large part 
of the rocks through which the locks at Gatun were to be con- 
structed. | 

From fossils collected both by Hill and myself at Monkey 
Hill and Gatun, Dr. Dall considers that the Monkey Hill for- 
mation is equivalent to the Chipola Oligocene, that is, younger 
than the Vicksburg or the Orbitocdes marls of Pena Blanea. 
Among the species recognized are: 


Cardium sp. Turritella 
Liocardium serratum Linn. Oliva sp. 
Psammobia Cadulus 
Cytherea Cerithiopsis 
Abra Agriopoma 
Tellina Cyclinella. 
Chione 


Directly below and within a foot or two of the point where 
these fossils were collected at Gatun is a coarse conglomerate 
also containing numerous fossils that are pronounced by Dall 
as of the same age as those found near Gatun in the Bohio 
beds. The conglomerate appears to grade upward into the 
fine caleareous sandstone or marl that contains the younger 
fossils, and were it not for the definite indication of greater 


*Op. cit., 176-177, 208. 


E. Howe— Geology of the Isthmus of Panama. 229 


age from the fossil evidence, I should be inclined to consider 
this conglomerate a basal member of the Monkey Hill forma- 
tion ; it is, of course, not impossible that this may be the case 
and that the fossils were derived from the erosion of the older 
Bohio terrane. Less than half a mile in a straight line from 
this locality is the point where the Bohio (Claibornian) fossils 
were collected at the edge of the French canal near Gatun 
(Kilometer 10), and the general dip of the beds at this locality 
is in the direction of the conglomerates exposed at Gatun. 
In any event the base of the Monkey Hill formation must be 
very near the conglomerate, whether actually at the top. or 
including the conglomerate. Unfortunately there are no 
other exposures in the vicinity to throw light on this matter 
and little can be learned from the drill records. The conglom- 
erate is clearly shown by a number of borings, below which 
are beds of a white pumiceous tuff associated with other con- 
glomerates similar to the uppermost one, and calcareous sand- 
stones and marls. Beneath these beds are fine calcareous or 
argillaceous sandstones of uniform composition that undoubt- 
edly belong to the Bohio formation. 

At Gatun about eighty feet of the Monkey Hill formation 
is shown, but, as in the case of the other sediments, it is only 
possible to give an approximate estimate of the thickness of 
the whole formation. [rom rough calculations, assuming low 
dips of from one to five degrees from Gatun northward, there 
should be a thickness of at least five hundred feet in the vicin- 


_ ity of the Monkey Hills near Colon, while perhaps from two 


to three times this thickness may exist. To the west, where 
the Chagres leaves its main valley and passes through a younger 
valley to the sea, a thickness of from one hundred and fifty to 
two hundred feet is actually shown in the hills, while as much 
more must exist beneath the present floodplain of the river if 
the dips observed in the region are at all regular. 

No rocks corresponding in age to those of the Monkey Hill 
formation have been observed on the Pacific side of the isth- 
mus. 

The lithologic character of these rocks is essentially the 
same as that of the finer-grained Bohio rocks. They are com- 
posed almost entirely of the debris of igneous rocks, in some 
cases the particles being exceedingly fresh, but commonly 
decomposition and fineness of texture make it impossible to 
say whether the material was derived directly from volcanic 
eruption or from the degradation of an older land surface. I 
am in favor of the latter hypothesis, inasmuch as no evidence 
has been found elsewhere of contemporaneous eruptions. 


230 EF. Howe—Geology of the Isthmus of Panama. 


Ianrous Rocks. 
Acid Porphyries and Tuff. 


The oldest igneous rocks, the breccias of the Obispo forma- 
tion, have already been described, and it has been shown that 
eruptions of much the same character continued intermittently 
for some time during the period of early Tertiary sedimenta- 
tion. After an interval of quiet, eruptions of an entirely dif- 
ferent sort of rock took place either at the close of the Bohio 
epoch or at the beginning of the Monkey Hill. These later 
eruptives are largely fragmental and are found on both the 
Atlantic and Pacific sides of the isthmus. The massive rocks 
of this period are best shown at Ancon Hill, which is com- 
posed entirely of rhyolite porphyry. Almost completely sur- 
rounding Ancon Hill, the continuity being broken only on the 
west by a later intrusion of pyroxene-andesite, are tuffs and 
fine breccias of the same composition as the rhyolite porphyry 
of the hill. The tuffs are well bedded and in some places 
quite massive, individual beds varying from six inches to five 
or six feet in thickness; they are fine-grained and, where 
exposed near the surface, usually altered to a white clay. 

Beds similar to those in the vicinity of Panama are exposed 
between San Pablo and Tabernilla on the Atlantic slope, the 
best outcrops being along the Chagres River near the point 
where the Panama Railroad crosses northwest of San Pablo. 

These comparatively siliceous rocks are the ones that Hill 
placed in his Panama formation; he referred to them as rhyo- 
litic tuffs,* while Bertrand considered them as trachytic.t 
Specimens that I collected from various points showed greater 
or less decomposition in most cases and none was sufiiciently 
fresh for chemical analysis. A microscopical study shows 
that they are all closely related and that in addition to the 
occurrences mentioned, certain intrusives in the Culebra beds 
probably belong to the same series. It is impossible to group 
all these rocks under one descriptive head such as rhyolite 
tuff or trachyte tuff; certain facies are distinctly rhyolitie, 
others trachytic, while forms near quartz-bearing latite are not 
uncommon. 

The rock of which Ancon Hill is composed is a creamy- 
white porphyry with phenocrysts of feldspar in a fine felsitic 
groundmass; occasional specks of an altered dark mineral are 
present. Microscopically the rock is seen to be a porphyry 
with phenocrysts (mentioned in order of relative abundance) 
of albite, quartz, and orthoclase in a groundmass containing 
abundant orthoclase, some quartz and a little albite. Slight 
kaolinization of the feldspars has taken place, and the ferro- 


* Hill, op. cit., 199-202. + Bertrand, op. cit., 9, 28. 


E.. Howe— Geology of the Isthmus of Panama. 281 


magnesian mineral, altered beyond recognition, has stained the 
rock slightly with iron oxide; there is no indication that the 
dark silicate was an important constituent. Another specimen 
of the same rock from a near-by locality showed little or no 
porphyritic texture,; a few fragments of orthoclase and laths 
of oligoclase are pr esent, with many large irregular patches of 
quartz; there is some magnetite and limonite but apparently 
no ferro- magnesian miner al. 

The islands of Naos and Culebra in Panama Bay, between 
three and four miles from Ancon Hill, are composed of a similar 
porphyry containing a moderate number of phenocrysts of 
plagioclase ranging from andesine to a labradorite (Ab,An,), 
-and hornblende. The groundmass is holocrystalline and con- 
sists of orthoclase and plagioclase in about equal amount with 
traces of hornblende, usually altered to chlorite, some magnet- 
ite, and quartz. 

Closely related to the rock of Naos Island is an intrusive 
sill found in the beds at Culebra north of Gold Hill (Cerro 
Culebra). This rock is a fine-grained porphyry with a fiuidal 
base, largely glassy, but containing a few microlites of plagio- 
clase and minute grains of orthoclase. The phenocrysts are 
mostly andesine although labradorite is present. A dark min- 
eral, perhaps hornblende, was observed in several specimens, 
but in all cases it has been considerably altered. In one speci- 
men it was impossible to decide whether the altered mineral 
had been hornblende or biotite, the ragged form suggesting 
the latter. Near Las Cascadas, and associated with the Obispo 
breccia, a dense rock with a marked fluidal texture is exposed 
at several places. Under the microscope it is found to consist 
of a partly glassy groundmass, laths of plagioclase, a little 
orthoclase and an abundance of fine grains of magnetite. The 
few plagioclase phenocrysts are considerably decomposed and 
ferro-magnesian minerals are notably absent. 

All of these rocks, with the exception of the Ancon porphyry, 
appear to be intermediate between true rhyolites and latites, 
with perhaps a stronger tendency toward the latitic form; the 
impossibility, however, of determining the exact character of 
the groundmass in most cases pr events a definite classification 
by microscopical methods, and none of the specimens, as has 
been said, was sufficiently fresh to warrant chemical analysis. 
The tuff exposed by the Chagres River in the vicinity of San 
Pablo consists of small fragments of fibrous or vesicular glass 
or pumice of low specitic “gravity ; there are occasional ~ par- 
ticles of plagioclase and orthoclase crystals but no quartz. A 
greater textural variation is found in the tuffs in the vicinity 
of Panama; they are less pumiceous and consist of fragments 
of rock essentially the same as that of Ancon Hill. 


232 EF. Howe—Geology of the Lsthmus of Panama. 


The relation of the tuffs and fine breccias in the vicinity of 
Panama to Ancon Hill suggests that the pyroclastics were 
derived from a volcanic center now marked by the massive 
porphyry of Ancon. The tuffs, as has been said, are well 
stratified and surround Ancon Hill except in the vicinity of 
Sosa; they dip away from Ancon Hill at all points and in a 
few instances have been found to be cut by dikes that appear 
to radiate from the hill as a center. No local source or center 
of eruption for the tuffs on the Atlantic slope has been found, 
and it is possible that they may have been derived from the 
Ancon eruptions, the distance between the points being only 
twenty miles. The extremely hght pumiceous character of 
the San Pablo deposits would favor this view. 

The age of the acid eruptives is fairly well shown at several 
places. Near Panama evidence from borings quoted by Ber- 
trand* indicates that the acid tuffs are younger than the 
Culebra beds and rest upon them. I was unable to find bor- 
ing records at the localities mentioned by Bertrand, but the 
field relations fully justify Bertrand’s view. The Culebra 
beds disappear beneath the surface of the lower Rio Grande 
Valley near Pedro Miguel, and at Miraflores the acid tuffs are 
well exposed at a number of points. Borings made in explor- 
ing for dam sites between Sosa Hill and Corazal and also 
across the mouth of the Rio Grande indicate the presence of 
sediments similar to those of the Culebra beds at approxi- 
mately seventy or eighty feet below sea level, and one boring 
near La Boca showed a dike of rock similar to that of Ancon 
Hull cutting these sediments. On the Atlantic side between 
San Pablo and Tabernilla there is no surface evidence bearing 
on the age of the acid tuffs. Borings for a dam site near San 
Pablo indicate rocks similar to those.of the Bohio breccias, 
beneath what I believe to be tuffs of the acid series, but the 
advanced decomposition of the rocks makes it difficult to dis- 
tinguish one from another, and the supposed tuffs may be 
sandstones of the Bohio formation. It was mentioned, in 
describing the Gatun occurrence of the Monkey Hill beds, 
that beneath the uppermost conglomerate borings revealed the 
presence of one or more beds of extremely fine white pumi- 
ceous tuff, and recent excavation for a road from the old Gatun 
railway station to the encampment at the top of the hill has 
exposed the tuffs. They are clearly interstratified with the 
sediments, but as previously stated, it is difficult to determine 
the base of the Monkey Hill beds, so that the tuffs may be 
regarded as lying either at the top of the Bohio or at the base 
of the Monkey Hill formation. In either case there can be 
no doubt that they are younver than the Eocene sediments and 
not Cretaceous, as supposed by Hull. 


* Op. cit., 8-9. 


FE. Howe— Geology of the Isthmus of Panama. 238 


Basie Intrusives. 


The last phase of eruptive activity of which there is evidence 
in the Canal Zone is represented by numerous basic intrusives 
that occur in great abundance in the central and southern 
_ parts of the isthmus. To the north, on the Atlantic coast, 
they are exposed in the vicinity of Porto Bello, and about 
eighteen miles east of Colon. Between Gorgona and Pedro 
Miguel most of the hills are composed of the basic rocks. In 
all observed occurrences the rocks are intrusive in the older 
formations and most commonly occur as large stock-like 
masses; dikes are numerous but no surface flows have been 
found. The rocks that have been collectively referred to as 
basic intrusives are pyroxene-andesites or basalts. All are 
notable for the calcic character of the feldspar, which is fre- 
quently bytownite or anorthite. Augite and magnetite are 
abundant and many of the rocks contain considerable ortho- 
rhombic pyroxene. The majority of the rocks are pyroxene- 
andesites, but basalts are common and in one or two instances 
were found to contain much olivine; practically all have more 
or less glass in the groundmass and some are vesicular. 
Although undoubtedly related to the andesites from which the 
Obispo breccias were derived, none of the Obispo rocks shows 
the extremely basic character of many of the later intrusives. 

_At many places in the interior the basic intrusives may be 
seen cutting the older sedimentary rocks, while the relations 
near Panama seem to indicate that the andesite of Sosa Hill 
has been intruded into the rhyolitic tuffs of Ancon. So far 
no basic rocks have been observed to cut the Monkey Hill for- 
mation, but the large masses of pyroxene-andesite at Porto 
Bello are probably intrusive in these sediments althongh no 
contacts have been observed. The very uniform lithologic 
character of the Monkey Hill beds, and the lack of any 
observed unconformity indicating decided crustal movements 
such as must have accompanied the intrusion of the andésites, 
would seem to show, in the absence of any more direct evi- 
dence, that the period of basic intrusions followed the 
Monkey Hill epoch and may have been the immediate cause 
of the termination of that long period of quiet sedimentation. 


Distribution of the Rocks. 


Unfortunately little is known of the areal distribution of 
the various formations that have been described. The section 
exposed along the canal line is fairly complete and in places 
it has been possible to trace certain of the formations a few 
miles beyond the boundaries of the Canal Zone, but even if 
greater areas had been examined it is doubtful if any more 


Am. JouR Sci.—FourtH Series, Vout. XXVI, No. 153.—SEPTEMBER, 1908. 
Aly 


234 L. Howe—Geology of the Isthmus of Panama. 


definite information in regard to the limits of the different 
formations could have been obtained. To a moderate degree 
the character of the topography may be taken as a guide and 
the known distribution of the different sorts of rocks thus 
slightly extended. This applies more especially to areas of 
sedimentary rocks as contrasted with those of igneous forma- 
tions. 

Obispo brecccas.—In the vicinity of Matachin Obispo bree- 
cias form the hills north of the Chagres, but the surface 
extension of the formation in this direction can not be great, 
for, not more than four miles northwest of Matachin, younger 
sediments are exposed in the neighborhood of Tabernilla and 
Frijoles. From Matachin southeasterly the breccias occur on 
both sides of the canal, in places covered by the Culebra beds, 
beneath which they eventually disappear between Empire and 
Culebra; they again make their appearance in the vicinity of 
Corozal and they have been noted at several places in the hills 
traversed by the old Cruces trail northeast of Miraflores and 
Pedro Miguel. The breccias are particularly well shown in 
the rolling country northeast of the city of Panama near Las 
Sabanas. From borings, the Obispo is known to occur as far 
north as San Pablo, but beyond that point there is no evidence 
of its existence. 

Basic intrusives.—Although the basic intrusives are not 
limited to any particular part of the isthmus, they are most 
abundant in the areas characterized by the Obispo breccias. 
In the Culebra region they are especially numerous, and are 
believed to make up a large part of the mountainous region 
southwest of the city of Panama along the Pacific coast; near 
the shore are many exposures of columnar basalt that have 
been observed beyond the mouth of the Chorrera River, 18 
miles southwest of La Boca. No basic intrusives have been 
found northwest of San Pablo in the Canal Zone, but at Porto 
Bello, about 18 miles northeast of Colon, pyroxene-andesites. 
are exposed at the water’s edge and occur in many of the 
near-by hills. 

Acid eruptives.—The rhyohtic rocks and others related to 
them occur in two general areas. One of these is at Panama, 
where the well-bedded tuffs surround the central mass of 
rhyolite porphyry of Ancon Hill. The fragmental rocks 
underlie the city and extend as far north as Miraflores. Sim- 
ilar rocks are also found on the southwest side of the Rio 
Grande opposite La Boca, while massive rock like that of 
Ancon Hill composes the islands of Naos and Culebra in 
Panama Bay. Hershey has reported similar rocks more than 
one hundred miles to the southwest near Santiago.* The 


* The Geology of the Central Portion of the Isthmus of Panama, Oscar H. 
Hershey, Bull. Dept. of Geol., Univ. of Cal., vol. ii, p. 244, 1901. 


E. Howe— Geology of the Isthmus of Panama. 285 


second area, in the vicinity of San Pablo and Tabernilla, is 
probably more restricted than that of the Pacific side. The 
rocks are best exposed along the Chagres River near San 
Pablo, but the hills extending northward from Barbacoas, 
where the Panama Railroad crosses the Chagres, are composed 
entirely of these acid pyroclastics. Their exact northwestern 
limit is unknown but probably lies at some point between 
Buena Vista and Tabernilla. Similar rocks are found in the 
vicinity of Gatun interbedded with the sediments at that 
locality. 

Sedimentary rocks.—A little more is known in regard to 
the distribution of the sedimentary formations. So far as my 
observations go, the Culebra beds are restricted to the occur- 
rences in the Culebra district with a probable extension as far 
south as La Boca suggested by borings. On the northern side 
the sediments from the Bohio formation up to the Monkey 
Hill have a much wider distribution. The sediments extend 
from Limon Bay along the line of the canal to Bohio at least, 
and remnants of the Bohio formation have been found as far 
south as Matachin. The subdued topography characteristic 
of areas of these young sedimentary rocks extends in a north- 
easterly direction from Colon almost to Porto Bello and 
throughout this distance I believe that sedimentary rocks are 
the only ones represented at the surface. Between this coast 
belt and the interior, where the limestones of the upper 
Chagres are exposed, isa region of some elevation concerning 
which there is no information whatever except quite near the 

canal line, at Tabernilla and Frijoles, where poorly exposed 
sediments ‘containing lignite are known to occur. Southwest 
of the canal line and along the Atlantic slope sediments have 
been traced for nearly twenty miles up the valley of the 
Trinidad River. The rocks of this region are of the same 
character as the Bohio or Monkey Hill formations ; they are 
exposed at a few places along the water’s edge, but the rock 
at these outcrops is in an extremely decomposed condition and 
no fossils were discovered. On the Pacific coast southwest of 
the city of Panama and beyond the range of hills composed 
of basic intrusives is the broad low valley of the Chorrera, 
that, on account of its very subdued topography, looks as if it 
had been eroded in sedimentary rocks. The Chorrera River 
rises near the head waters of the Trinidad and it is not improb- 
able that the sedimentary rocks extend across the divide and 
down the Chorrera to the Pacific. According to Lull,* coal, 
uly a lignite, occurs in the drainage of the Rio Indio, 

* Reports of Explorations and Surveys for the location of Interoceanic Ship 


Canals through the Isthmus of Panama, E. P. Lull, U. S. N., Washington, 
1879. Pp. 30-82. 


236 8 £. Howe—Geology of the Isthmus of Panama. 


and the deposits may be reached from the Pacific side by 
ascending the Chorrera River. The locality is indefinite, but 
eannot be far from the head waters of the Trinidad, where 
similar lignites have been reported. 


Structure. 


The broader features of the geological structure of the 
isthmus are simple. In the Canal Zone the sedimentary rocks 
of the Atlantic side dip toward the coast at moderate angles 
while on the southern side of the isthmus the inclination of 
the Culebra beds is in the direction of the Pacific. It has not 
been possible to discover any marked characteristic structure 
in the Obispo breccias ; in the central region the few contem- 
poraneous flows appear to be nearly horizontal, while no evidence 
of stratification can be made out in the occurrences near 
Panama and Las Sabanas. 

When examined ‘in greater detail it is found that the ineli- 
nation of the older sediments on the Atlantic side of the 
isthmus is greater than that of the Monkey Hill beds. The 
strikes also are different; that of the Bohio formation, best 
shown at Bohio and Vamos Vamos, being about northeast- 
southwest, while the Monkey Hill beds at Gatun strike more 
nearly east and west. This agrees with the evidence of uncon- 
formity between the Bohio formation and the Orbitozdes beds 
of Pefia Blanca. No indication of marked faulting has been 
discovered in the region north of Empire, although local frac- 
turing and minor dislocation have occurred at places where 
the folding appears to have been pronounced as at Vamos 
Vamos, according to Hill, and to a minor degree at Gatun. 

The acid tuffs at San Pablo are inclined to the northwest at 
angles of from five to ten degrees; with the exception of 
isolated patches of Bohio conglomerate near Matachin these 
are the last beds encountered, following the canal southward, 
in which any structure can be made out until the Culebra beds 
are reached near Empire. 

South of Empire greater structural complexity exists. The 
Culebra beds are locally folded, but have a general south- 
easterly dip of from ten to fifteen degrees. At several points 
the Culebra cut is crossed by small faults, the downthrows 
of from ten to fifty feet being to the southeast. At the deepest 
part of the cut, where the canal passes between Gold Hill and 
Contractor’s Hill, the Culebra shales with the breccias in the 
upper part of the section have been intruded by basalt and 
since intrusion have suffered faulting. The mass of Gold Hill 
has dropped as a block or wedge between the beds on either 
side, being bounded on the north and south by faults; during 


FE. Howe— Geology of the Isthmus of Panama. — 237 


the process of faulting, the sediments, previously deformed by 
the intrusions of basalt, were still further twisted and now dip 
at angles of sixty deer ees or more to the northeast mto Gold 
Hill. 

Between Culebra and the Pacific the structure is simple. 
The Culebra beds, frequently intruded by broad dikes of basalt, 
are gradually carried by their prevailing southeast dip beneath 
the level of the Rio Grande valley not far from Pedro Miguel. 
From Miraflores to the outskirts of the city of Panama the acid 
tuffs have been locally folded, but in the neighborhood of 
Ancon Hill and under the town their structure, as already 
mentioned, appears to be due to initial dips of the beds depos- 
ited on the fianks of the old Ancon voleano. That is, in 
tracing the beds from north of Ancon around the hill toa point 
on the shore close to Sosa Hill the strike is found to swing 
through an angie of nearly one hundred and eighty degrees ; 
the dips range from five to fifteen degrees, the steeper inclina- 
tion being found near the base of Ancon Hill. 

Reviewing these facts, the structure of the isthmus appears 
to be characterized by a dominant arch or broad anticline with 
its axial trend between east-west and northeast-southwest, the 
crest of the arch being in the south-central part of the isthmus 
near Bas Obispo. The northern limb of the anticline is of 
moderate inclination, while the southern limb, near the crest of 
the arch at least, is steeper. The limestones and calcareous 
sandstones of the upper Chagres are nearly at the crest of the 
fold and their prevailing southwest to west dip suggests that 
the anticline pitches to the southwest. Whether this isa broad 
structure or comparatively local is not known, no evidence 
having been found in the country southwest of the Canal Zone. 
It is probable that the westward pitch is more than a mere 
local cross fold and due to the same uplift that formed the San 
' Blas Range to theeast. Unfortunately there is little or no 
trustworthy information as to the geology of these mountains 
other than that they are believed to have a core of granular 
rock* intruded in late Tertiary time. It must be borne in 
mind, however, that there is evidence of a decided orogenic 
movement in this region in late Eocene time that caused the 
uncontormity at the base of the Pefia Blanca Orbitozdes beds 
it is not impossible that the supposed southwest pitch of the 
anticline may be due to the earlier deformation. 


Washington, D. C. 
* Hill, op. cit., pp. 211-213. 


238 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. GEOLOGY. 


1. Geology of the Adirondack Magnetic Iron Ores; by 
D. H. Newtanp, with a Report on the Mineville-Port Henry 
Group ; by J. FE. Kemp. N. Y. State Mus. Bull. 119, 8°, pp: 
182, pls. and maps. Albany, 1908.—This work gives a detailed 
description of the geology, petrography, and occurrence of the 
iron-ore bodies in the eastern and northern Adirondack region. 
It contains also much material relating to the history of the min- 
erals and mining of the area. It will no doubt prove of great 
service to those locally concerned in these deposits, and contains 
much of interest to those engaged in economic geology and in 
the study of ore deposits. From the descriptions given it would 
appear that the unusable titaniferous ores are magmatic segrega- 
tions of the gabbro-anorthosite masses (p. 149); while the 
purer and worked magnetites, which have a different method of 
occurrence, are probably, in part at least, due to pneumatolytic 
processes as suggested by the presence of fluorite in the Palmer 
hill and other mines (pp. 31-33 and 100). Levees 

5. Geologische Prinzipienfragen ; von KH. Rryrer. Pp. 202, 
254 figs. Leipzig, 1907 (Wm. Engelmann).—There was a time, 
in the recollection. of older geologists, when Reyer’s name was 
associated with the active publication of works on various geo- 
logical subjects and on the geology of particular regions, marked 
by a highly theoretical and, at times, imaginative treatment. In 
the present work the author states that finding his views, espe- 
cially those relating to the origin of mountain ranges, not gener- 
ally accepted, he engaged in lines of work other than scientitic, but 
now, convinced that eventually his experiments and views 
must prove of service, he feels it incumbent upon him to publish - 
them in a general statement.. While it would be entirely out of 
place in this brief notice to enter into a critical discussion of the 
author’s views on fundamental geological problems, it may be men- 
tioned that some of the more important subjects treated relate to 
the origin and manner of igneous intrusions and extrusions, to 
the part played by volcanic islands, to the igneous phenomena as 
displayed in the Alps, to the origin of mountain ranges, to ele- 
vation and depression of the crust, etc. The author says frankly 
at the outset that he expects opposition to his views, which, in 
many cases at least, depart widely from those generally held 
to-day, and in some instances represent theories which have been 
discarded in the evolution of geological science. While this is 
true, the work is at least suggestive, and even if the reader does 
not accept the presentation of the particular theses discussed, he 
may find a strong sidelight cast on some special problem in 
which he is interested. ‘ada 0 IVES 

2. Die Entstehung der Kontinente, der Vulkane und Gebirge ; 
von P.O. Kéuter. 8°, 58 pp., Leipzig, 1908 (Wm. Engelmann).— 


Geology. 239 


These are momentous questions to be considered and answered 
in 58 pages, and therefore the author does not waste time in pre- 
liminaries, or in: consideration of details. He believes that the 
view, often advanced, that the features of the earth mentioned in — 
the title are caused by the contraction of a cold crust settling 
down to fit a still hot, but cooling and contracting, nucleus, is 
essentially wrong. He essays to prove that the crust is losing 
heat faster than the interior, and that this interior, as compared 
with the outer shell, is relatively stable. The latter, instead of 
being under contractional stresses, is in a state of tension. The 
relative movements of the outer surface, which give rise to earth 
features, are ascribed to the action of water, which penetrating 
downward to the heated zone below, returns in a hot condition, 
warming the superincumbent masses and thus causing them to 
expand. By this mechanism, in various ways, he endeavors 
to show that the continents, volcanoes, and mountain ranges are 
formed. 

While it is not probable that this brochure will be taken very 
seriously by those who still hold by the nebular hypothesis of 
the earth’s origin, and will seem to followers of Chamberlin’s 
planetesimal hypothesis much lke a charge upon windmills, it 
may be still said that it is well and clearly written, and in places 
contains suggestive ideas. Bi Wee 

3. Geological Survey of Canada, A. P. Low, Director.— 
The following publications have been recently issued : 

Annual Report, New Series, Volume XVI, for 19045 this 
contains Reports A, B, C, CC, G, H and 8 and is accompanied 
by a series of fourteen maps. Ottawa, 1906. It is stated that 
this volume is the last to be published in this form, the plan 
being to present in future each report as a separate publication. 

Summary Report for the calendar year 1906 ; pp. 206. Ottawa, 
1906, 

The Falls of Niagara; by J. W.W. Spencer, 1905-6. Pp. xxv, 
490, with 43 plates and 30 figures. Ottawa, 1907. This volume 
was noticed in an earlier number (vol. xxv, p. 455). 

Report on Gold Values in the Klondike high level Gravels ; 
by R. G. McConnety. Pp. 34, with one plate and a geological 
map. 

The Telkwa River and Vicinity, B. C.; by W. W. Leacu. 
Pp. 27, with a geological map. Ottawa, 1908. 

Report on a portion of Northwestern Ontario, traversed by the 
National Transcontinental Railway, between Lake Nipigon and 
Sturgeon Lake; by W. H. Couuins. Pp. 23, with a geological 
map. Ottawa, 1908. 

4. Geography and Geology of a Portion of Southwestern 
Wyoming, with special Reference to Coal and Oil; by A: C. 
Veatcn. Prof. Papers, 56, U. 8S. Geol. Surv., pp. 178, 1907 
(=1908).—This is a very important paper for statigraphers and 
paleontologists, and, especially, for those interested in the discus- 
sion as to whether the Upper Laramie is to be referred to the 
Mesozoic or the Tertiary. Theauthor shows that the Cretaceous 


240 Scientific Intelligence. 


of this region ‘has the enormous thickness of over 20,000 feet,” 
and is a conformable series, beginning with the Bear River forma- 
tion, and closing with the Adaville formation=Lower Laramie. 
Then followed “a long period of folding, faulting and erosion.” 
Angularly unconformable with the Cretaceous series are the 
Evanston, Almy and Fowkes formations, followed by another 
period of “folding and erosion of great magnitude though of 
much less importance” than the earlier one. The Almy and 
Fowkes formations “have without exception been considered 
Kocene,” and, as they are conformable with the Evanston, all are 
regarded by Veatch as best placed in the Kocene. ‘The uncom- 
formity at the base of this series [Evanston, Almy, and Fowkes] 
amounts to over 20,000 feet ; that at the top amounts to perhaps 
5,000 feet, but this is of much less relative significance than the 
figures indicate, because the movements of the second disturb- 
ance were along lines of weakness produced by the first. The 
physical break between this group and the known Cretaceous 
beds is thus greater than the break between it and the known 
Kocene, and, on purely physical grounds, this group would seem 
to belong rather to the Eocene than to the Cretaceous ” (p. 75—76). 
Cais: 

5. Hinfiithrung in die Paldontologie ; von Gustav STEINMANN. 
Second edition, pp. 542, with 902 text-figures. Leipzig, 1907 
(Wilhelm Engelmann).—This well-known introduction to paleon- 
tology has been enlarged and brought up to date. It treats of 


plants (pp. 13-74), invertebrates (75-388), and vertebrates (389— ~ 


514). All of the more important groups of forms found fossil 
are defined and illustrated, so that any beginner in paleontology 
may obtain a good knowledge of the hard parts of extinct organ- 
isms. No detailed classifications appear, nor is there any extended 
discussion of lines of descent. The book presents what is known 
of the leading forms in each group of organisms in short synoptic 
form. The illustrations are wood-cuts and line drawings, made 
especially for this book, and are abundant and adequate. c. Ss. 

6. Niagara Stromatoporoids; by W. A. Parxs. Univ. 
Toronto Studies, Geo]. Ser., 1908, pp. 175-240, pls. 7-14.—Pro- 
fessor Parks here continues his detailed studies on American 
Silurian stromatoporoids. At least 34 forms are described, many 
being new. Chalazodes is the only new genus. C. 8. 

7. On an Occurrence of Hybocystis in Ontario; by W. A. 
Parxs. Ottawa Nat., XXI, 1908, pp. 232-236, pl. 2.—Very 
excellent material of this obscure echinoderm has been found near 
Elton, Ontario. The material is described and figured in detail, 
indicating, the reviewer thinks, cystid rather than blastid char- 
acters. Cc. S. 


Il. MiscetuAnrous Screntiric INTELLIGENCE. 


1. Publications of the Japanese Harthquake Investigation 
Committee.—Nos. 22 A and 22 C of this issue have recently 
been received, also Vol. II, No. 1, of the Bulletin of the Commit- 
tee. This last contains 8 articles by Prof. F. Omori, all of inter- 


Miscellaneous Intelligence. 241 


est to those concerned with seismology. One of these is an 
interesting discussion on microtremors and another gives a list of 
prominent Japanese earthquakes between 1902 and 1907. 

In No. 22 C an account is given by T. Wakimizu of a new vol- 
canic island in the Iwdjima group, remarkable because of its 
ephemeral character. On February 1, 1905, this island was 3 miles 
in circumference and 480 feet in height, but on the 16th of June 
it was reduced to alow reef only 1,500 feet long and less than 
10 feet high. In June of the present year it is stated that the 
new island was entirely buried by the sea. Interesting accounts 
are also given of the other islands of the group, accompanied by 
a series of excellent plates. 

Volume xxiv of the Journal of the College of Science, Imperial 
University of Tokyo, is devoted to an investigation of the sec- 
ondary undulations of ocean tides, carried out by the order of the 
Earthquake Investigation Committee during 1903-1906. It is 
accompanied by 95 plates, maps and charts. The authors are K. 
Honda, T. Terada, Y. Yoshida and D. Isitani. 

2. The Physical Basis of Civilization ; by T. W. HEINEMAN. 
Pp. 241. Chicago, 1908 (Forbes & Co.).—The author advances 
the theory in this book that the physical, mental, moral, and 
social conditions of the human race are due to two compara- 
tively slight structural modifications of the ape-like ancestors 
of man: first, the lengthening of the foot by the modification 
of the great toe, which gave man a position on his feet of far 
greater firmness than that of any existing apes; and second, the 
position of the skull with reference to the spinal column, on 
account of which the erect position of the body is more readily 
maintained. As a result of the specialization of the feet for sup- 
porting the body firmly, the hands were left free for grasping 
and handling and the sense of touch became more highly devel- 
oped so that a more efficient means of acquiring knowledge of — 
surrounding objects was opened to man ; likewise, the elevation 
of the special sense organs high above the ground by the erect 
attitude widened the range of their usefulness and thus led to 
the increase of the intelligence of man. The upright position, 
and consequent exposure of the vital organs to attack, and the 
comparative defenselessness of the human species, rendered his 
survival in the struggle for existence dependent upon conduct to 
a greater extent than in any other known animals, and the 
extreme disability of the pregnant female made the devotion of 
the male to his mate and the establishment of the family relation- 
ship necessary conditions for the survival of the race. B. w. K. 

3. General Physics. An elementary Text-book for Colleges, 
by Henry Crew. Pp. xi, 522 with 40 figures. New York, 1908 
(The Macmillan Co.). —This text-book is in its treatment dis- 
tinctly above the plane of the high school type, and yet, without 
sacrifice of accuracy, maintains throughout a simple, lucid 
exposition of the fundamental principles of the subject. The 
scope of the book is obvious from the title and number of pages 
stated above. The presentation of the subject matter is excel- 
lent. There is in it little to suggest the older purely descriptive 


242 Screntifie Intelligence. 


texts and happily less of the more recent tendency toward a 
presentation so severe as to engender in most beginners a hatred, 
rather than a love of the subject. The author has adopted, in 
general, if not uniformly, a happy method of leading up to prin- 
ciples through a simple discussion of the knowledge already 
in the student’s possession. The mathematical expressions are 
developed in a natural and consistent manner and are made to 
serve effectively both in summarizing the respective topics and 
in revealing to the student ‘the essential unity of the subject.” 
Practically all of the illustrations are diagrammatic and clear. 
Problems are found in ample number and variety. The text 
lends itself readily to abridgement or amplification, and taken 
as a whole this appears to be one of the best recent text-books. 
Di wAQGKe 

4. Die Insektenfamilie der Phasmiden ; bearbeitet von K. 
Brunner v. Watrenwyt und Jos. Reprensacuer. II Liefe- 
rung, pp. 181-340; IIL Schluss-Lieferung, pp 341-589, with 
plates xvi-xxvil. Leipzig, 1908 (Wm. Engelmann).—The first 
part of this monumental work on the Phasmids appeared in the 
spring of 1907 (see vol. xxii, 398). ‘The two parts now issued | 
complete the work. Of these the second is devoted to the 
Clitumnini, Lonchodini and Bacunculini; it has been prepared 
by the senior editor. ‘The third and concluding part embraces 
the Phibalosomini, Acrophyllini, and Necrosciini and has been 
worked up by Prof. Redtenbacher. The whole work is admir- 
ably thorough and is based, not only upon the very extensive 
private collections of the authors, but they have also taken 
advantage of the material in various public museums, especially 
those in Europe, which have most freely placed their collections 
at their disposal. The publication of the whole work in the 
liberal form presented, with its numerous plates, has been made 
possible through the support of the Imperial Academy at Vienna, 
the funds being furnished by the Treitl Foundation. 

5. Les Dépéts Marins; Lion W. Cotter. Pp. 325, with 
35 figures. Paris, 1908 (O. Doin).—This volume forms one of 
the issues of the “ Encyclopédie scientifique” which is being pub- 
lished under the direction of Dr. Toulouse. If carried through 
on the very liberal scale planned, the Encyclopedia will include 
40 sections, aggregating about 1000 volumes. 

The work in hand is one of seven volumes, to be devoted to 
physical oceanography, which are in charge of Dr. J. Richard. 
The author, who has studied with Sir John Murray at Edinburgh, 
presents here an excellent summary of the whole subject of 
marine depositions, giving the results contained in the well-known 
work by Murray and Renard on Deep Sea Deposits, and also 
bringing the various branches of the subject down to date. The 
concise, systematic treatment of the whole makes it a very con- 
venient résumé of a subject of more than usual interest. 


OBITUARY. 


JAMES Duncan Hague, long prominent as a mining engineer, 
died on August 5 at the age of seventy-two years. He was one 
of the geologists of the Survey of the 40th Parallel in 1867-70. 


SUPPLEMENT. 


Arr. XXV.—On the Esterification of Malonic Acid; by 
I. K. Puetes and E. W. Tiruotson, JR. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxi. | 


Frinxetstetn*™ has shown that diethyl malonic ester may be 
prepared by dissolving malonic acid in the least possible 
amount of absolute alcohol before saturating with hydrochloric 
acid gas. The excess of alcohol is then distilled off, the resi- 
due poured into water, neutralized with sodium carbonate, and 
extracted with ether. On evaporation of the ether, diethyl 
malonic ester, boiling for the most part at 195°, is obtained. 
He gives no quantitative results. Conrad+ has followed a pre- 
cisely similar procedure, using the calcium salt of malonie acid 
instead of the acid itself. The yield given is 70 per cent of 
that theoretically possible. Quite recently Bogojawlensky¢, 
by boiling a solution of malonic acid in alcohol under a return 
condenser for six to seven hours, in the presence of anhydrous 
copper sulphate or potassium pyrosulphate as dehydrating 
agents, has obtained yields of malonic ester 68 per cent of that 
theoretically possible. In former papers§ from this laboratory 
studies of conditions giving high yields of the ethyl esters of 
succinic and benzoic acids have been made. And, further, 
the effect upon the quantity of ester produced, caused by vary- 
ing three factors in the reaction, was shown. These factors 
were, first, the quantity of alcohol, second, certain catalyzers, 
and third, the period of the time of action. In this paper a 
similar study of the esterification of malonic acid with ethyl 
alcohol is recorded. for the preparation of pure malonic acid, 
the diethyl ester was purified by repeated fractional distilla- 
tions under atmospheric pressure. Portions of malonic ester, 

* Ann., cxxxiii, 338. tIbid., eciv, 126. 

t Berichte, xxxviii, 3344. 

§ This Journal, xxii, 368; xxiv, 194; xxv, 39. 

|| In distilling the ester, the following simple modification of the Hempel 
bead column was found advantageous. To the lower end of the column, 
which was 15™™ in diameter, was fused a glass tube 7™™ inside diameter and 
d™ long, the lower end of which was ground off at an angle.. To prevent 


the beads from falling through this tube, two devices were made use of. 
Hither A, shown by itself, or B, shown in position in such a column in the 


244 Phelps and Tillotson, Jr.—Malonic Acid. 


boiling within two-tenths of a degree, were hydrolyzed by 
heating at a temperature of about 50°, a mixture of ester and 
water in nearly equal amounts with a few dr ops of nitric acid, 
for some time after the mixture became homogeneous. The 
solution was then transferred to a porcelain dish and evapo- 
rated to the point of saturation at a temperature not exceed- 
ing* 60°, filtered while hot, and stirred while cooling. After 
recrystallizing from water, ‘the acid was dried, first ‘in the air, 
and then to constant weight in a desiccator over sulphuric acid. 
The malonie acid prepared in this manner was proved to be 
pure by titrating it against standard sodium hydroxidet and 
barium hydroxide solutions. 


eut. A is a glass tube 1°™ in diameter, drawn together at either end, and 
held in place in the column by three ‘‘ tears” fused to it. Bisa smal] glass 
rod bent into a U shape wide enough to slip easily into the column. To the 
bottom of the U are fused one or more crosspieces of the same small glass 
rod, thus forming a grating which allows a ready escape for the vapors and. 
the return of condensed liquid. The number of crosspieces necessary varies, 
obviously, with the internal diameter of the column and the size of the 
beads used. This device is also useful in connection with constricted side- 
necked flasks, since very little constriction is sufficient to hold it in place. 
The device can be varied for introducing a bead column in the side neck of 
a Claisen flask by lengthening the upright rods sufficiently for the device to 
be held in the angle of the side-neck tube. This modification obviates the 
necessity of constricting the neck in this case. Even in distilling high boil- 
ing point liquids like diethyl malonic ester, when the amount of liquid flow- 
ing back is large, liquid does not collect insuch a column. In practice, B 
seems preferable to A on account of the more ready back flow of liquid. 

* F, Lamouroux, Compt. Rend., cxxviii, 998. 

+ This Journal, xxvi, 138. 


Phelps and Tillotson, Jr.—Matonie Acid. 245 


The alcohol used was the alcohol of commerce made as free 
as possible from water by repeated distillations over fresh cal- 
cium oxide. Pure zine chloride of commerce was freshly 
fused and treated with a current of dry hydrochloric acid gas 
until a clear melt was obtained; then this mass was heated for 
a short time to expel any hydrochloric acid gas before cooling 
and granulating. 

In every experiment recorded in Table I, weighed portions 
of malonic acid were treated with definite amounts of absolute 
alcohol, alone, or charged with a known amount of dry hydro- 
chlorie acid gas with or without a definite weight of zinc 
chloride, in the special arrangement of flasks described in a 
former paper for use in esterifying succinic® acid. In all 
experiments, except those in which the treatment was special, 
definite amounts of malonic acid with 40°"° of absolute alcohol, 
alone or charged with dry hydrochlorie acid gas, or in presence 
of whatever other catalyzer was employed, were heated in a 
500™* round-bottomed flask, while the remainder of the alco- 
hol used containing hydrochloric acid or not, as shown in the 
table, was boiled in a second 500°* round-bottomed flask, and 
passed in vapor form to the bottom of the malonic acid solu- 
tion in the first flask, which was kept at a temperature of 100° 
to 110° by heating in a bath of sulphuric acid and potassium 
sulphate. The temperature in the esterification flask was regis- 
tered by a thermometer dipping into the alcoholic solution and 
held in place by a three-bored rubber stopper which carried 
the inlet tube, and also a Hempel bead column, arranged as 
described in the paper to which reference has been made, to 
provide an outlet for the vapors liberated in the flask. 

The product obtained was transferred, with the aid of a 
small amount of ether, to a separating funnel containing 
chipped ice, and treated with an excess of an aqueous solution 
of sodium carbonate. The ethereal solution was washed with . 
a solution containmg sodium chloride. To recover traces of 
ester in the wash waters, the carbonate and chloride solutions 
were shaken out twice, successively, with fresh portions of 
ether, the ether extracts combined in a 250° side-necked 
flask fitted for vacuum distillation, with a capillary tube and 
receiver consisting of a 100° side-necked flask connected 
through a manometer to an aspirating pump. The low-boiling 
products, consisting chiefly of ether, alcohol and water, were 
removed by heating the flask containing the ester solution in a 
water bath, finally at a temperature of 60° for fifteen minutes 
after the manometer showed a pressure of 15™™. The water 
bath was then replaced by an acid potassium sulphate bath, 
heated to about 140°, and the diethyl malonic ester distilled 


* This Journal, xxiv, 194. 


246 


Phelps and Tillotson, Jr.—Matonie Acid. 


and collected in the 100° side-necked receiver, which was 
kept cool by allowing a stream of cold water to flow over it 


constantly. 


In every experiment in Table I the flow of hot alcohol vapor 
was started into the maloniec acid solution before the tempera- 


No. 


(Ye 
ise) 
— 


(22) 


Malonic 

acid ZnCl, 
grm. grm. 
50 Sui 
50 re 
50 dee 
50 Ey 
50 pS 
50 05 
50 te) 
50 1°0 
50 1:0 
50 1°0 
50 1:0 
50 1:0 
50 120) 
50 1:0 
50 10°0 
50 10°0 
50 10°0 
50 10°0 
50 10°0 
HON AOLOr, 
50 = 10°0 
AO O70 


TABLE I. 
Alcohol Reaction 
with HCl time 
(FS |) 
em®, percent hr, min. 
200 Lee 1 50 
200 132653 epee 
200 1°25 1 45 
300 1°25 20) 
100 1°25 Berth ae 
100 1°25 Ae ey 
200 1:25 Dts oe 
40 1°25 
160 oe Bie nays) 
200 as J) AO 
40 1°25 
160 Ee BAS 
40: 1°25 
160 ae “4545 
40 Ho's) 
160 ae: 1 40 
200 1°25 tis 
300 1°25 er O 
40 10 | 
260 jes Leo 
40 10 
260 ee 2 30 
40 1°25 
160 tae ce Mes Ob 
40 25 
160 ae te G0) 
200 WAS DAS 
200 10 55 
200 10 1 30 
400 125 ea) 
200 1°25 A) 
200 129 books 
200 1°25 Ae GRAD 
200 1 heaaes) Eee 595) 


Malonie ester 


Theory 
erm, 
76°92 
76°92 
76°92 
76°92 


16°92 


76°92 
76°92 


76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
76°92 
GoO2 


76°92 


Ae 


7 ea 
per cent 
70°2 
84°5 
89°1 
94°0 


93°7 


84°0 
47°0 


. 9073 
82°6 
87:0 


90°0 
92°71 


93°2 


ture reached 105°, which temperature was attained within fif- 
teen minutes after beginning the experiment, and a steady 
current was maintained afterwards, holding the temperature 
between 100° and 110° till all the alcohol had been distilled 


Phelps and Tillotson, Jr.—Malonie Acid. 247 


over, except in experiments (5), (9), (10), (21) and (22), where 
the treatment was special. In experiment (5) the malonie 
acid, dissolved in the first portion of alcohol shown in the 
table, and contained in the 500°" round-bottomed flask, was 
heated on a water bath at 50° for three hours, then connected 
with a vacuum pump and heated with the water bath at the 
same temperature until 40° of liquid, consisting, presumably, 
of water and alcohol, had distilled over. The second -portion 
of aleohol was then added and the heating on the water bath 
at 50° continued for four hours, after which about 80° of 
liquid was removed under diminished pressure as before. 
Finally, 40° of the third portion of alcohol shown in the 
table was added and the process of esterification completed in 
the same manner as in the otherexperiments. In experiments 
(9) and (10) the current of alcohol vapor at first was slow; 
in the case of experiment (9), for fifteen minutes; in the case 
of experiment (10), for an hour, and more rapid for the remain- 
der of the time. In experiment (21), after treatment in the 
usual manner with the first portion of alcohol, the low-boiling 
products were removed under diminished pressure by heating 
the esterification flask on a water bath at 60° till the manome- 
ter showed a pressure of 15™™ for fifteen minutes, and the proc- . 
ess of esterification was repeated with the second portion of 
alcohol, shown in the table. In experiment (22) the malonic 
acid, zine chloride and 200™* of alcohol were boiled in the 
500° round-bottomed flask under a return condenser for 
forty-five minutes before continuing the esterification with the 
second portion of alcohol in the usual manner. 

To learn whether any ester had distilled with the alcohol 
during the esterification, several of the alcoholic distillates 
were cooled with ice diluted with three or four times its 
volume of water and shaken out separately three times with 
fresh portions of ether, washing the collected portion with a 
solution of sodium carbonate, and, finally, with pure water. 
The combined ether solutions were then fractioned in vacuo as 
described above. In no case was malonic ester found in the 
distillates tested. The loss inherent in the process employed 
for recovering the pure ester from the crude material, produced - 
in the esterification flask, was determined by treating 75 grm. 
of pure malonic ester by the same procedure, described above, 
for the crude material. The loss amounted to 1:25 erm. 
of malonic ester. 

From experiments (1), (2), (8) and (4) of Table [it is plain 
that an increase in either the amount of alcoho] containing 
hydrochloric acid, or the time of- action, gives an increase in 
the amount of ester produced. Comparing experiments (1) 
and (7), absolute alcohol alone, in the absence of zinc chloride, 


248 Phelps and Tillotson, Jr.—Matlonic Acid. 


acting for a longer time, produces a far greater amount of ester 
than is obtained by the use of zine chloride for a shorter time. 
However, if, as in experiment (8), a small amount of hydro- 
chloric acid is present with the zine chloride, the yield is 
increased 43 per cent over experiment (7) when zine chloride 
was present but no hydrochloric acid, and 5°5 per cent over 
experiment (2), when hydrochloric acid was used with no zine 
ehloride. In experiment (11) the use of 1 grm. of zine chlo- 
ride with hydrochloric acid gives an increase of 5°5 per cent 
over experiment (2), where zine chloride was not used. Com- 
paring experiments (6), (8) and (15), it is apparent that under 
similar conditions, 1 grm. of zine chloride gives better yields than 
0-5 grm. or 10 grm. for the shorter time, while for a longer 
time, as shown in experiments (10) and (16), 10 grm. of zine 
chloride seem to give the better yield. Increasing the amount 
of alcohol driven over in the same time, as shown in experi- 
ments (11) and (12), gives a decided increase in the amount of 
ester obtained, while increasing the amount of hydrochloric 
acid to 10 per cent tends to reduce the amount of ester formed, 
as is evident In experiments (18) and (19). In experiments 
(1) to (4) and in eertain of the others, ethyl acetate was 
. detected by its odor in the first few drops of the distillates, 
but when the esterification was partially completed on a water 
bath, as in experiments (5) and (22), before continuing in the 
regular apparatus, no ethyl acetate could be detected by its 
odor in the presence of the large mass of alcohol, and, in the 
case of experiment (22) a better yield of ester was obtained. 
It is possible that in experiment (5) some ester was lost during 
the treatments under diminished pressure, as described above. 

For all the experiments in Table II, sulphuric acid of com- 
merce sp. gr. 1°84, and commercial alcohol, made anhydrous by 
the method described, were used. In the experiments in series 
A, the procedure was precisely as in the experiments of Table . 
I. Inseries B, malonic acid was treated with the first portion 
of alcohol and the small amounts of sulphuric acid, shown in 
Table Il. This solution was boiled under a return condenser 
for one hour, then the second amount of sulphuric acid was 
‘added and the process of esterification completed with the 
second portion of alcoho] in the usual manner. In series O, the 
procedure was the same as that described for experiment (5) of 
Table I. It was found in experiment (1) of series A that 
when malonic acid was treated in the esterification apparatus 
in the presence of sulphuric acid, there was a distinct odor of 
ethyl acetate in the distillate, indicating decomposition of the 
malonic acid, or the acid ester, but when the alcoholic solution 
was boiled under a return condenser for an hour, as in experi- 
ment (4) of series B, the odor of ethyl acetate was not 


Phelps and Tillotson, Jr—Malonie Acid. 249 


observed. There was also some decomposition, as evidenced 
by the odor of ethyl acetate in the distillate of experiment 
(2) of series B, when the solution was heated immediately to 
105° in the esterification apparatus, but if the temperature was 
kept at 90° for fifteen minutes, as in experiment (8) of series 
B, the ethyl. acetate was not detected by its odor in the distil- 
late in the presence of the large amount of alcohol. For the 
purpose of examining the distillates more closely for the pres- 
ence of ethyl acetate, blank tests were made by mixing in a 
side-necked flask, connected: with a condenser, a solution of 
aleohol and ethyl] acetate with an equal volume of concen- 
trated sulphuric acid, and heating the liquid to a temperature 
of 80°, at the same time passing a current of air through the 
liquid. About 3° of the distillate was collected in a gradu- 
ated pipette, containing an aqueous solution of sodium chloride, 
and thoroughly shaken. When 50° of alcohol and 1:8 of 
ethyl acetate, which was calculated as the least amount to be 
found in any of the distillates, if all of the malonic acid not 
found as ester had been decomposed, was treated in this man- 
ner, 0°4°™ of liquid separated out, easily recognized by its 
characteristic odor as ethyl acetate. In treating by the process 
outlined above the first 50°™* of the alcoholic distillates of 
experiments (5) and (6) of series B and (1) and (2) of series C, 
no ethyl acetate could be detected. 

In order to learn, if possible, whether the loss of malonie 
acid in the process of esterification was due entirely to decom- 
position, or whether part of the malonic acid was incompletely 
esterified, experiments were made to discover if malonie acid 
could be recovered from water solution. Shaking out a water 
solution containing sodium chloride and 2 grm. of malonic acid 
three times with ether gave 0-05 srm. of malonic acid, but when 
5 grm. of malonic acid, in a similar solution, were treated 
eighteen hours in an ether extractor, and the ethereal solution 
evaporated under diminished pressure at 60° until the manom- 
eter registered 15™", 4°97 orm. were recovered. A _ blank 
test on 5 grm. of pure malonic acid showed no loss in drying 
from an aqueous ether solution at 60° in vacuo. The sodium 
carbonate wash waters were acidified with hydrochloric acid 
and treated for eighteen hours in an extractor similar to that 
described by Van Rijn*, except that an ordinary test tube 
of about 100° capacity was used instead of the constricted 
and perforated tube employed by him. The amounts of 
malonic acid so recovered are shown in Table II. The amount 
of malonic ester taken up by the sodium carbonate wash 
waters was determined by ablank test on 75 grm. of pure malonic 
ester, which was treated with a sodium carbonate solution, as 


* Berichte, xxviii, 2387. 
Am. Jour. Scit.—FourtTH Series, Vout. XXVI, No. 153.—SEPTEMBER, 1908. 


250 Phelps and Tillotson, Jr.—Malonic Acid. 


described for the recovery of malonic ester. Upon acidify- 
ing this sodium carbonate solution with hydrochlorie acid 
and treating in the extractor as outlined above, 0°30 orm. of 
malonic acid equivalent to 0°39 grm. of ester was obtained. 

In calculating the figures given in the last column that 
stand for the percent of malonic acid, or ester, unaccounted 


TaBLeE IT. 
Malonic acid 
— es -— 
Malonic ester FYoundin Not 
Malonic ——_—_*——_— wash accounted 
No. acid Alcohol H.SO, Time Theory Found Percent water for 
orm, acm. | orm, hr min orm. soma. . grm. per cent 
A 
40 2:00 ; 
1 oD 160" 222) A= 15 8 7G592 70296) 92730 ne is ae 
B 


OO; 0-15 = 0 

150.5 200. -_- 8 1 — 00. 7692. 367-625 87-90) aslo 7°8 
60 O15 1-00 | 

F250. 140) A855 1 00n) 76:92... 70:00)» Ol 00pm awe 5:8 
100 2p O21 5 1 00 

32° 250) 200) 1°85 90 —45., 16:92 70-84) 02209. eos A'S 
100) 0-1 00 

A. 50°. 200, 1°85 1 = 00 71692" Fi50 92-95) aaa is 
OOS IPSae 


9) 50° 200 1°85 2—00 76°92 73°12 95°06 0°36 3°2 
MOOT 0S, ie— 00 
6 50 +) 300). 11:85 = 235)" 76:92 72°60" 94:38) sare 3°9 


100-015, >1—00 
7 50 200),- 4:85" 4 — 00 76:92" (70°93) 92:24 1°80 3°2 


C 
100% 015 to — 00 
LOO 22 4 — 00 
SOV ALS Oy se ey 
] 50 2007 eee v2 00M iG 22 ai 3 es OS ai 0°39 2°4 
100 2°00 4-00 
100 baa ss 0 
OO wero s hee 


2) = OO 200. +... 2-00. 76°92 73°94 96:11 0°40 ropes | 


for, it was considered fair to add to the amount of malonic 
ester obtained in a single experiment 1°25 grm., the amount 
found by the blank test to be the loss inherent in the process 
of recovery of the pure ester. To this sum was added the 
amount of ester equivalent to the difference between the 
malonic acid obtained from the sodium carbonate wash waters 
and 0°39 grm., which as has been shown is the fraction of the 


Pheips and Tillotson, Jr.—Malonic Acid. 251 


1:25 orm. loss in the process of recovery, taken up by the sodium 
carbonate water, and recovered as malonie acid by the ether 
extraction. ‘Taking, for example, experiment (2) of series C in 
Table II, of the 0-40 grm. of malonic acid recovered from the 
wash water, 0°30 grm. was presumably due to the action of the 
sodium carbonate on the ester during the process of shaking 
out with ether.. We have then, 73:94 grm. of ester found, 1°25 
erm. of ester lost during the process of recovering the ester and 
acid, corresponding to 0°18 grm. of ester, remaining unesterified. 
The total, therefore, of ester accounted for is 75°32 grm. or 
97-9 per cent, leaving 2°1 per cent lost, probably through decom- 
position. In this particular experiment, as well as in experi- 
ment (1) of series C, a part of the loss is due to vaporization of 
ester during the interpolated treatments under diminished 
pressure. | 

From the results shown in Table II it is evident that under 
conditions which give the best yield, not more than 0°10 germ. of 
malonic acid remains unesterified, and, further, that about 
1 grm. or two per cent of acid is lost through decomposition. 
Under conditions less favorable for theoretical yields, a larger 
amount of acid remains unesterified, and at the same time the 
amount lost by decomposition is gr eater. Comparing experi- 
ments (2) and (3) of series B, it is evident that increasing the 
amount of alcohol with which the malonic acid is treated on 
the water bath, from 60°™* to 100°", increases the yield by one 
per cent, while if malonic acid is treated with several portions 
of alcohol as described above, and shown in experiments (1) 
and (2) of series C, or if the time of driving over the second 


portion of alcohol is increased as in experiment (5) of series 


6, a much larger yield of ester is obtained. Merely increas- 
ing the amount of alcohol distilled over, as in experiment (6) 
of series B, gives no better yield than under otherwise similar 
conditions in experiment (5). In experiments (1), (4) and (7) 
it is plain that with small amounts of sulphuric acid, esterifi- 
cation is not complete, while with larger amounts the yield of 
ester is apparently not quite as good as that produced by two 
grams. by varying the time in experiments (3), (4) and (5) of 


series B, a larger yield of ester is obtained, with increase in 


the time taken to distil the second portion of aleohol, while if 
the alcoholic solution of malonic acid is heated for a longer 
time on the water bath, as in experiments (1) and (2) of series 
C, the yield is materially increased. 

The ester obtained in all the experiments of Tables I and II 
was found to be in a high state of purity, since, on redistilla- 
tion, it showed no considerable variation in boiling point. 

From the work here described, it may be seen that in gen- 
eral, increasing within limits the amount of alcohol used, and 


252 Phelps and Tillotson, Jr.—Malonic Acid. 


the time during which it is allowed to act, produces a more 
complete esterification of malonic acid. Larger amounts of 
zine chloride up to 10 grm. appear to increase the yield as in 
experiments (1), (4) and (17) of Table I, while the use of 5 grm. 
of sulphuric acid seems to possess no advantage over 2 grm., as 
is shown in experiments (4) and (7) of series B in Table II. 
Under similar conditions, however, 2 grm. of sulphuric acid 
with 200% of absolute alcohol running for one hour and fifteen 
minutes in experiment (1) of series A in Table II gives a yield 
of malonic ester nearly equal to that produced by 1 grm. of zine 
chloride and 300° of alcohol, charged with 1°25 per cent 
hydrochloric acid and running for 50 minutes, in experiment 
(12) of Table I, or to that produced in experiment (17) of 
Table I by 10 grm. of zine chloride and 200°™* of alcohol 
charged with 1:25 per cent hydrochloric acid. 

Finally it has been shown that by allowing malonic acid and 
absolute alcohol to react in the form of apparatus described, a 
yield of malonic ester, equal to the best described in the litera- 
ture, may be obtained, while by treating for a long time with 
alcohol char ged with hydr ochloric acid increases the yield over 
twenty per cent. The presence of sulphuric acid or of zine 
chloride and alcohol charged with hydrochloric acid permits 
the action to proceed in a shorter time. The best yields of 
malonic ester were obtained by causing the esterification to 
proceed as far as possible at a temperature below that at which 
the malonic acid decomposes. This was accomplished, as 
described above, by heating an alcoholic solution of malonic 
acid with sulphuric acid on a water bath at 50° for eight hours, 
and treating the residue obtained in this manner with a fresh 
portion of alcohol for a period of two hours. By following 
this procedure, a yield of 96-1 percent of malonic ester was 
obtained, with only 2-1 per cent lost, either through decom- 
position of the acid, or acid ester, or by volatilization of the 
ester. 


; } 
Phelps and Eddy—Purification of Esters. 253 


Art. XXVI.—Concerning the Purification of Esters; by 
J. K. and M. A. Portrs and E. A. Eppy. 


_ [Contributions from the Kent Chemical Laboratory of Yale Univ. —elxxxii. ] 


QUANTITATIVE studies of the ester reaction were made under 
the direction of one of us and published earlier in this Jour- 
nal.* In that work the exactness was shown with which in 
the preparation of the ethyl esters of succinic, malonic and 
benzoic acids, the crude product of esterification obtained in 
the special form of apparatus used, may be treated to isolate 
the pure ester. In brief this treatment consisted in shaking 
out the crude ester with ether, in the presence of an excess of 
sodium carbonate in solution, distilling off under diminished 
pressure the low boiling point products, and, finally, the ester. 
which was collected and weighed. This method of purifying 
esters is a modified form of the procedure in common use for 
isolating a pure ester from the crude product obtained during 
esterification. Otherst have separated by distillation under 
diminished pressure the water taken up by the ether during 
the shaking out of the crude ester from the sodium carbonate 
solution. This method of removing the water at as low a 
temperature as possible, so that hydrolysis may not take place, 
is particularly adapted for use in a quantitative study of the 
ester reaction. The organic acid unesterified and the mineral 
acid used as a catalyzer is commonly removed by treatment 
with sodium or potassium carbonate. Where the esters are 
soluble in water Fischer and Spiert{ varied the procedure by 
treating the erude product from esterification with an excess 
of pulverized potassium carbonate, and removed, after long 
shaking, the potassium salt by treatment with ether. The 
filtrate was freed from ether on a water bath and fractionated 
under diminished pressure. 

A-study is given here of the exactness with which dry 
potassium carbonate may be used in isolating succinic, malonic 
and benzoic ethyl esters impure with alcohol, water, unesteri- 
fied organic acid and small amounts of mineral acid. For this 
purpose mixtures of the purified esters were made with the 
substances, as shown in the table, and the ester separated and 
weighed. 

Definite portions, 75 grm. each, of carefully purified diethyl 
succinate, diethyl malonate, or ethyl benzoate were placed in a 
Claisen flask of 250°™° capacity, chilled in ice, together with 
2 grm. of the corresponding acid, 2° of concentrated hydro- 

* This Journal, xxiii, 368; xxiv, 294; xxv, 39; xxvi, 148. 
+J. Am. Chem. Soc., xxiii, 1105, 1896. 
¢ Berichte, xxviii, 3252. 


254 Phelps and Kddy— Purification of Esters. 
chloric acid of commerce or 1°” of concentrated sulphuric acid 
of commerce, 10°™* of alcohol nearly absolute and an excess— 
10 grm.—of either pure potassium carbonate of commerce or 
the same freshly fused and cooled before introducing into 
the ester mixed with impurities. These impurities are pres- 
ent here in larger proportion than would be expected if the 
ester were produced according to the procedure referred to 
earlier in this paper. The Claisen flask was connected for dis- 
tillation under diminished pressure with a second Claisen flask 
of 100° capacity used as a receiver. To secure a current of 
air through the apparatus during the entire operation an open 
lass tube was used in place of the usual capillary tube. The 
100° Claisen was connected either directly or with a glass 
tube held through a rubber stopper to the larger Claisen, the 
side neck of which was very short, in the same manner. as has 


Kster 

meat eas <a 

Alcohol HCl H.SO,4 K.CO; Organic acid Recovered 
No. em’. cm. em?) erm? 2 grm. 7o grm. erm. 
( 1) IK Oe 10 Succinic Succinie 74°40 
( 2) HOE a 10 Succinic — Succinic 74°67 
(3) 10 1 10" Suceimic ouceinic 74°41 
( 4) 10 1 10 Succinie  Succinic 74°56 
( 5) LOwe 2 10 Malonic Malonic 74°24 
( 6) 10 2 10 Malonic’ Malonic 74:20 
Gy 10 1 10 Malonic Malonic 74°31 
( 8) 10 1 10 Malonic Malonic 74°27 
(9) 10 2 10 SBenzoie Benzoic —- 74°55 
(10) Ose 10 Benzoic Benzoic 75°00 
(11) 10 1 10 ~~ Benzoic Benzoic 74°60 
(12) 10 1 10 Benzoic Benzoic 74°67 


been described in a former paper® for the distillation of a sub- 
stance where loss of some of it in the side neck of the flask might 
otherwise be expected. The 250°" flask was then heated 
under diminished pressure by means of an acid potassium sul- 
phate bath at a temperature of 100°-110° for about an hour, or 
until no further evolution of carbon dioxide indicated that the 
acid was completely neutralized, while at the same time a cur- 
rent of water was allowed to strike the receiver constantly 
during neutralization to condense all products possible. The 
temperature of the acid bath was then raised and the ester 
carefully distilled into the receiver, taking care by raising the 
temperature of the bath and flaming to remove the final traces 
of the ester held on the side wall of the flask. The contents 


* This Journal, xxiv, 479. 


Phelps and Eddy—Purification of Esters. 255 


—ester, alcohol and water—of the second 100°™* Claisen flask, 
connected in the manner just given for distilling under dimin- 
ished pressure, were carefully fractionated by heating the 
Claisen flask in a water bath raised slowly to 60°, which tem- 
perature was maintained for 15 minutes after the manometer 
showed a pressure of 15™™, and the ester distilled in the 
usual manner into the flask, weighed, in some instances, alone, 
in others, with the short tube held in place during distillation 
by the rubber stopper, and the weight of ester determined. 

In all the experiments in the table except (3), (4), (8) and (10) 
the potassium carbonate was ignited betore attempting to 
neutralize the esters mixed with organic and mineral acids. 
In experiments (3), (4), (7), (8), (9) and (10), both in distilling 
and redistilling the ester from the Claisen flasks the process 
was carried out in flasks where the shortened side-neck tube 
of the first flask was held with a glass tube through a rubber 
stopper. It seems evident that igniting freshly the potassium 
carbonate is unnecessary. Further, the jointed apparatus does 
not appear to diminish the small loss of ester. 

The purity of the product obtained was shown by redistilling 
the recovered ester at atmospheric pressure, when it was found 
that the entire portion distilled within a fraction of a degree. 

From an inspection of the results obtained it is clear that 
diethyl succinate, diethyl malonate and ethyl benzoate may be 
freed from small amounts of mineral and organic acids, when 
alcohol is present, by heating suitably with dry potassium car- 
bonate under diminished pressure, and that the total product 
obtained in this way, fractionated under diminished pressure, 
gives a satisfactory indication that ester is not lost in consider- 
able amounts. The losses in the treatment of the masses of 
75 grm. each of pure ester as in the former work from this 
laboratory, referred to above, amounted to 0°6 grm. in the 
case of the recovery of succinic ester, to 1°25 grm. in the case 
of malonic ester, and to 0°25 grm. in the case of benzoic ester. 
While the loss in the recovery of ethyl benzoic ester by neu- 
tralizing as described with dry potassium carbonate is slightly 
greater than by shaking out with ether, the loss in recovering 
diethyl succinic ester is somewhat less, and the loss in recover- 
ing diethyl malonic ester is much less than by shaking out 
with ether. But, even in the case of ethyl. benzoic ester, the 
treatment with dry potassium carbonate is to be preferred of 
the two procedures, both on account of the greater ease in 
manipulation and on account of the saving in expense, since 
dry potassium carbonate accomplishes the purpose of the 
aqueous sodium carbonate and shaking out with ether. 

Obviously it is possible to neutralize the acid impurities pres- 
ent with these esters with dry potassium carbonate completely 


\ 


256 Phelps and LKddy—Purvjication of Esters. 


and advantageously. Itis easy to see, however, that the smaller 
the amounts of free acid, the more completely can the total 
amount of ester present be recovered. With such amounts of 
unesterified acid as remain when organic acids are treated 
with alcohol containing mineral acid, on a return condenser, 
according to Fischer, the loss of ester might be considerable. 
But with such amounts of free acid as are left when esters are 
made in the special form of apparatus described in a former 
paper, neutralizing in the manner given here with dry potas- 
sium carbonate is easily done without loss of ester in consider- 
able amount. This is obviously true, since in the mixtures 
shown in this paper the esters contain acid impurities far in 
excess of the amount that would be found when esterifying 
under proper conditions for ideal yields. 


Phelps and Tillotson, Jr.—Cyanacetic Ester. 257 


Art. XXVII.—On the Conversion of Cyanacetic Ester to 
Malonic ster; by I. K. Puetrs and E. W. Tixtorson, 
JR. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxiii. | 


Koxrse* and Millert, in synthesizing the acids of the oxalic 
acid series from derivatives of the acetic acid series, note that 
if cyanacetic acid or its ester is boiled with a concentrated 
solution of potassium hydroxide, potassium malonate is 
obtained. This treatment with potassium hydroxide was fol- 
lowed by Finkelsteint, Franchimont$, Von Mailler| and Con- 
rad“, but in no case were the quantities obtained given. Van’t 
Hoff**, starting with cyanacetic acid, states that the yield of 
malonie acid obtained by this process is eighty per cent of that 
theoretically possible. He explains the loss as 5 due to decom- 
position according to this equation : 


CH,(COOK), + KOH = CH,COOK + K,Co.,. 


Franchimonttt and Van’t Hofftt both give it as their opinion 
that a better yield may be obtained by the use of hydrochloric 
acid in the place of potassium hydroxide as a hydrolizing 
agent. Hydrochloric acid was apparently first made use of 
for the purpose of converting cyanacetic acid to malonie acid 
by Grimaux and Tchierneaktt, later by Bourgoin§§, and by 
Claisen and Venable||. Noyes employed sulphuric acid in 
the presence of chlorides to effect the same conversion, but in 
none of the instances cited were the quantities obtained given 
to show the amount of malonic acid or ester obtainable from 
a given amount of cyanacetic acid or ester. 

For the work here recorded, cyanacetic ester was made by 
esterifying the acid obtained by acting on chloracetic acid with 
potassium cyanide under conditions which will be given in a 
later paper. The cyanacetic ester, synthesized in this way, 
was fractionally distilled at atmospheric pressure with a Hem- 
pel Te column of the particular form described in a former 
paper*** inthis Journal. The portions boiling within limits of 
four fone of a degree, 205°6°-206° (corrected), were used in 
all the experiments of series A in Tables I and Bi Daring 
the distillation under atmospheric pressure, the ester in the 
flask assumed a deep red color, gradually depositing a small 


* Ann., cxxxi, 348. + Ann., exxxi, 350. 
tAnn., cxxxiii, 338. § Berichte, vii, 217. 
|| Jour. Prakt. Chem. [2], xix, 326. {7 Berichte, xii, 749. 
** Berichte, vii, 1382. tt Loc. cit. 
tt Bull. Soc. Chim., xxxi, 338. S$ Comptes Rendus, xc, 1289. 
||| Ann., eexviii, 131. «|4| Jour. Am. Chem. Soc., xviii, 1105. 


*** This Journal, xxvi, 243. 


258 Phelps and Tillotson, Jr.— Cyanacetic Ester. 


amount of a reddish-brown insoluble substance. The ester 
obtained in this manner gave the following analyses : 


I. 0°3252 grm. of ester gave 30°5°™ of moist nitrogen at 24° and 
758°2™™, N = 10°48 per cent. 
II. 0:4891 grm. of ester gave 45°8°™* of moist nitrogen at 25° and 
774™™, " N = 10:45 per cent. 
Calculated for C,H,O,N, N = 12°40 per cent. 


For the experiments in series B of Tables I and II the cyan- 
acetic ester was fractionally distilled under diminished pres- 
sure and was proved by the following analyses to be pure : 


j. 05020 grm. of ester gave 55°3°™* of moist nitrogen at 23° and 
763°2"™, N = 12-47 per cent. 
II. 0°5004 grm. of ester gave 55°™ oe moist nitrogen at 20° and 
758-2mm, N = 12°54 per cent. 
Calculated for C,H.O,N, N = 12°40 per cent. 


The alcohol used in all the experiments recorded was made 
as free as possible from water by repeated distillations from 
calcium oxide. Zine chloride of commerce was freshly fused 
for use in the experiments of Table I. In the experiments of 
Table IL sulphuric acid of commerce, sp. gr. 1°84, was employed. 

In all the experiments in Tables I and II, except those in 
which the treatment was special, 50 grm. of cyanacetic ester, con- 
tained in a 500°™* round-bottomed flask, together with definite 
amounts of absolute alcohol, zinc chloride or sulphuric acid, 
and with or without definite amounts of water, as shown in 
the tables, were saturated with gaseous hydrochloric acid, dried 
by passing through a wash bottle containing concentrated sul- 
phuric acid, keeping the solution cooled in a mixture of ice 
and salt. While the current of hydrochloric acid was still 
flowing, the ice mixture was replaced by means of a water 
bath, and the solution heated to the boiling point of the alco- 
hol under a reflux condenser for an additional period of time, 
as shown in the tables. | 

The ammonium chloride was filtered off and washed with 
absolute alcohol or ether. The filtrate was then treated in the 
special arrangement of flasks for esterification described in a 
former paper* in this Journal. For this treatment, 200° of 
absolute alcohol was distilled from the reservoir flask through 
a period of one and one-half to two hours. The crude product 
so obtained was transferred to a separating funnel containing 
chipped ice, an excess of sodium carbonate solution added to 
neutralize any free acid present, and the whole shaken out 
with ether. The ethereal solution was washed with water 
containing sodium chloride, and the carbonate and chloride 


* This Journal, xxiv, 194. 


Phelps and Tillotson, Jr.—Cyanacetic Kster. 259 
TABLE I. 
Hydrochloric 
acid Malonic ester 
Cyanacetic PA ae Sarees ———_, 
ester ZnCl, C.H;OH H2,O cold hot Theory Found Per 
Woe erm. orm. mols. mols. hr.” hr. germ. erm. cent 
ak 
CI). 50 1 3) dlls 4 2 67°61 61°20 90°5 
2) -250 1 5 2 i 2 67°61 60°95 90°1 
(3) 50 10 5) 0 4 3 67°61 64°59 95°5 
(4) 50 10 5) 0 t 0 67°61 64°88 96°0 
(5) 50 10 3) 0) 9) 0 67°61 38°31 56°6 
B | 
Cl) 1). 50 0 9) 0 + 0 70°80 67°15 94°8 
(2) 50 0) 5) 0 0) 2°5 70°80 66°05 93°3 
(3) 50 10 5 0 + 2 70°80 66°25 93°5 
TABLE II. 
Hydrochloric 
Cyan- acid Malonic ester . 
acetic SSS) a > 
ester H.SO, C2H;0H H.O cold hot Theory Found Per 
No. grm. grm. mols. mols. hr. hr. germ. grm. cent 
| A 
Cry 50 10 4°5 1 0 3 67°61 52°00 qiGw 
(2) 50 2 3) 1 + 2 67°61 63°72 94°2 
(3) 50 2 9) iP 11 9) 67°61 63°30 93°6 
(4) 50 aa, 3) 2 + 2 67:61. - 6Y°85 91°5 
(5) 50 2 10 Z 5) 2 67°61 55°84 82°5 
(6) 50 2 10 2 10 2 67°61 59°64 88°2 
(7) 50 4 3) 0 4 0 67°61 64°96 96°0 
(8) 50 4 3) 0 4 2 67°61 64°79 95°8 
(9) 50 + 3) 1 4 2 67°61 65°61 97°0 
(10) 50 4 10 2 8 2 67°61 57°22 84°6 
B 
CL 250 + 5 1) + 0 70°80 68°21. 96°3 
(26 50 + 3) 0 4 2 70°80 66°92 94°5 
(3) 50 4 9) 0 0 2 70°80 64°82 91°5 


wash waters were shaken out successively with two fresh por- 
The combined ethereal solutions of the ester 


tions of ether. 


were separated from low boiling impurities, distilled under 
diminished pressure in the usual manner, and the ester 
weighed. The malonic ester obtained was found to be pure, 
since it showed no considerable variation in boiling point. 

In experiments (8) of series A and (3) of series B of Table 
I, (8) of series A and (2) of series B of Table II, the filtration 
and process of esterification were omitted. . Enough water was 


260 Phelps and Tillotson, Jr.—Cyanacetic Ester. 


added to dissolve the ammonium chloride and the ester was 
recovered directly in the manner described above. In experi- 
ments (4) of series A, (1) of series B of Table I, (7) of series 
A and (1) of series B of Table II, after saturation with hydro- 
chloric acid in the cold, the solution was treated directly in 
the esterification apparatus, the ammonium chloride bein 
precipitated when the temperature had reached 60°-70° dur- 
ing the process of ésterification. In experiment (5) of series 
A of Table I, after saturating in the cold with hydrochloric 
acid, the excess of hydrochloric acid, alcohol, water and all 
low-boiling products were removed by heating the flask in a 
water bath at 50° under diminished pressure, and the 
remainder was esterified in the usual manner. In this experi- 
ment, no considerable amount of ammonium chloride was pre- 
cipitated, and there remained in the distillation flask a viscous 
fluid which did not distil with the malonic ester and which 
began to decompose on being heated to a higher temperature. 
In experiment (1) of series A of Table II, cyanacetic ester was 
boiled with alcohol sp. gr. 0°825 and sulphuric acid sp. gr. 1°84 
under a return condenser for two hours. and as no ammonium 
salt was precipitated, gaseous hydrochloric acid was passed in 
for three hours, the ammonium salt filtered off, and the pro- 
cess continued in the usual manner. 

The theory for malonic ester given in series A of Tables I 
and II was calculated on the basis of the analyses of the first 
sample of ester, given. above, and with the assumption that 
the substance was a mixture of cyanacetic and malonie esters. 
This assumption was apparently justified, first, by the fact 
that, on treatment, it yielded pure malonic ester, and second, 
on saponification, a mixture of cyanacetic and malonic acids 
was obtained. It was further assumed that all fractions pre- 
pared in the same way and boiling at the same temperature, 
205°6°-206° (corrected), had the same composition. Experi- 
ments (7) and (8) of series A of Table II were made using 
portions of the samples analyzed. The theory given in series 
B of both tables was calculated on the basis of pure ethyl 
cyanacetate. This is presumed to be justified by the analyses 
given above as well as by the yields of malonic ester obtained 
from it. 

The loss sustained by saturating an alcoholic solution of 
malonie ester with hydrochloric acid was determined by a 
blank test. When 75 grm. of pure ethyl malonate, with 125°™° 
of absolute aleohol was saturated with hydrochloric acid for 
the same time and under the same conditions as in the several 
experiments, 72°02 grm. were recovered, with a loss of 2°98 
grm. or 4:2 per cent. This loss must be added to the results 
given in the table in order to show the extent ‘of the conver- 


Phelps and Tillotson, Jr.—Cyanacetic Ester. 261 


sion by this procedure. From the results given in Table [I it 
is plain that with small amounts of zine chloride as catalyzer, 
in the presence of one or two molecules of water, malonic ester 
may be obtained to the extent of 90 per cent of that theoreti- 
cally possible, as shown in experiments (1) and (2) of series A. 
Taking into consideration the loss inherent in the process, we 
have 94 per cent accounted for. The loss of 6 per cent is 
doubtless due to decomposition of malonic ester or acid ester 
in the presence of water and the large amount of hydrochloric 
acid. When no water was used, as in the remaining experi- 
ments of the table, a much larger yield was obtained. Under 
these circumstances the water necessary for the conversion 
may have been formed in the secondary reaction between the 
alcohol and hydrochloric acid in the presence of the catalyzer, 
water and ethyl chloride bemg formed. The presence of ethyl 
chloride was detected in the alcoholic distillates from these 
experiments. It is also possible that the reaction took a differ- — 
ent course, the imido ester hydrochloride first formed reacting 
with alcohol to form ammonium chloride and the ortho ester 
which, in the presence of the large amount of alcohol and the 
eatalyzers, was easily decomposed with the formation of the 
normal ester and ethyl ether. This same sort of a reaction has 
been described by Claisen* in the case of acetals, which he 
finds are easily broken up by catalyzers with the formation of 
the aldehydes and ether. It is evident from the results 
obtained in experiments (1) and (2) of series B that the con- 
version of cyanacetic ester to malonic ester has been nearly 
quantitative, either because sufficient water has been formed 
in the secondary reaction mentioned above, or a reaction simi- 
lar to that pointed out by Claisen has taken place, with the 
formation of ethyl ether, or both of these actions have gone 
on simultaneously. That is to say, the water theoretically 
demanded by the equation for the conversion of cyanacetic 
ester to malonic ester need not be introduced as such when the 
conversion is effected by hydrochloric acid im alcoholic solu- 
tion. Since this is true and since malonic ester is so easily 
hydrolyzed, the better yields obtained without the use of any 
water are easily understood. . 

Experiment (4) of series A, which was treated in the esteri- 
fication apparatus in order to complete the esterification of any 
acid ester that might have been formed, if too much water 
were present for any reason, shows a slight increase in yield 
over experiment (3) of series A, which was shaken out 
directly after saturation with hydrochloric acid and treatment 
on the return condenser. In experiment (5) of series <A, 
after saturating in the cold with hydrochloric acid, the excess 


* Berichte, xl, 3903. 


262 Phelps and Tillotson, Jr.— Cyanacetic Ester. 


of water, alcohol, hydrochloric acid and all low-boiling pro- 
ducts were removed under diminished pressure by heating the 
flask with a water bath at 50°. The residue, consisting, pre- 
sumably, of imido ester hydrochloride, was then treated on 
the esterification apparatus as described above. The result 
indicates that, if hydrochloric acid is not present in sufficient 
amount, ethyl alcohol at a temperature of 100°-110° does not 
complete the reaction, while if large amounts of hydrochloric 
acid are present as in the other experiments of the table, the 
reaction proceeds at a temperature of 60°—70°. Experiment 
(2) of series B, which was treated with hydrochloric acid at 
the boiling temperature of the alcohol, shows not quite so 
good a yield as experiment (1) of series B, which was first 
saturated in the cold. The presence of large amounts of cat- 
alyzers in experiment (8) of series B produces a lower yield 
than that obtained in experiment (1) of series B, possibly 
through the formation of larger amounts of water and subse- 
quent decomposition of malonic ester. 

The experiments in Table II, in which sulphuric acid was 
used as a catalyzer, show the same general results as those of 
Table I. Better yields are obtained when no water is added, 
as in experiments (7) and (8) of series A and (1), (2) and (8) of 
series B, than in the remaining experiments where water was 
used. In experiment (1) of series A, sulphuric acid alone pro- 
duced no apparent conversion to malonic ester at the temper- 
ature of a water bath, but when hydrochioric acid was passed 
in, the ammonium salt was precipitated and malonic ester was 
formed. Experiment (7) of series A, which was esterified 
after saturation, shows a slightly better yield than experiment 
(8) of series A, which was shaken out directly after saturation 
and treatment on the return condenser. In series B the dit- 
ference is more marked in the case of experiments (1) and (2), 
respectively, which were similarly treated. In experiment (3) 
of series B, in which the gaseous hydrochloric acid was passed 
into a boiling alcoholic solution, the yield is much lower than in 
experiments (1) and (2) of series B, which were first saturated 
in the cold. 

The work here recorded has shown that the conversion of 
cyanacetic ester to malonic ester is apparently not effected at 
the temperature of a water bath by sulphuric acid, and that in 
the absence of large amounts of hydrochloric acid it proceeds 
slowly, if at all, at 110°. However in the presence of large 
amounts. of hydrochloric acid, with or without additional cata- 
lyzers, the reaction proceeds rapidly at the temperature of the 
boiling alcoholic solution. It has been shown that, in the pres- 
ence of one or two molecules of water, high yields of malonic 
ester may be obtained, but that better yields ‘result if no water 


Phelps and Tillotson, Jr.—Cyanacetic Ester. 263 


is added as such, in which case sufficient water is formed in a 
secondary reaction or else the ortho ester first formed is decom- 
posed into the normal ester and ethyl ether. High yields may 
be obtained without the use of a catalyzer other than the 
hydrochloric acid with which the solution was saturated, but by 
the use of an additional catalyzer as zine chloride, or prefer- 
ably sulphuric acid, nearly theoretical yields of malonic ester 
result. In experiment (7) of series A and (1) of series B in 
Table Il, if the loss of 4:2 per cent sustained by the treat- 
ment and the recovery of the malonic ester, in the amount used 
here and under these conditions, is considered, it seems prob- 
able that the conditions named above are those under which 
conversion of ethyl cyanacetate to ethyl malonate is complete. 
The best results were obtained when 50 grm. of cyanacetic ester 
with 125°™* of absolute alcohol and 4 grm. of sulphuric acid, 
cooled in a mixture of ice and salt, were thoroughly saturated 
with hydrochloric acid by passing in a stream of dry hydro- 
cehloric aeid for four hours, the resulting mixture being esterified 
during a period of two hours, at 100°-110°, with 200°” of abso- 
Inte alcohol. Under these conditions the yield actually 
obtained was 96°3 per cent of that theoretically possible. 


264 Phelps and Tillotson, Jr.—Cyanacetic Acid. 


Arr. XX VIIl.—fesearches on the Influence of Catalytic 
Agents in Ester Formation. On the Esterification of Cyana- 
cetic Acid ; by I. K. Puetrs and EK. W. Tittotson, JR. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxiyv. ] 


Van’t Horr* states that cyanacetic ester may be obtained 
by dissolving cyanacetic acid in alcohol, saturating with hydro- 
chlorice acid gas, pouring the mixture into water and extract- 
ing with ether, but he gives no data concerning the amount 
of ester to be obtained from a known amount of cyanacetie 
acid. In former paperst from this laboratory there have been 
shown the effects produced upon esterification of succinic, 
benzoic and malonic acids by varying the proportion of the 
reagents, the catalyzers and the time of reaction. In this 
paper is recorded a similar study with cyanacetic acid. 

Cyanacetic ester was prepared from chloracetic acid under 
conditions which will be described in a later paper. The ester 
boiling within four-tenths of a degree, was converted to the 
acid by heatmg with double its volume of water and a few 
drops of nitric acid, at a temperature of about 60°, for some 
time after the mixture had become homogeneous. The solu- 
tion was then evaporated at a temperature of 60° till the point 
of saturation was reached and the crystals which separated on 
cooling were recrystallized from a mixture of ether and chloro- 
form. The acid so obtained was in the form of very fine, 
perfectly white, hygroscopic crystals, melting at 66°1—-66-4° 
(corrected). 


TABLE I. 
Cyana- Alcohol Cyanacetic ester 
No. _ cetic with HCl Time — —_—A~— = 
acid ZnCl, H.SO, ——*~—— —*— Theory Found 
CTI CLM neti) fC HA CTICeMb MT aa ihen mcrae grm. Per cent 
40 ah 
= 2A. Fo ° 
(1) 50 See Sa GOs it 5 66°47 42°19 63°5 
40 1°25 2 ie } 
(2) 50 aon ee 160 1:25 1 .10 66°47 58°92) 8856 
40 1°25 ; ‘ : 
(3) 50 1 aes 160 1°25 1. 10 66°47: 5969s veaee 
40 1°25 2 AGIA 5 
(4) 50 10 me 160 1°25 1 A 66°47 63°18 95°'1 
AO eB leZo 4 : 
(5) 50 10 ue 160 1:25 1 2.) 66°47. S5soB Rear 
: 5 40 ..- An ; 
(6) 50 aie 0°5 160) eo 1 10 66°47 $2°68 94°3 
AUS a : 
(7) 50 ca 2°0 1600 te. 1 5 66:47 OL:20 29 6a6 
: 2 OMe ; 
(8) 50 sc 2°0 eg oe 2 10 66°47 64:52 97-1 


* Berichte, vii, 1382. + This Journal, xxiv, 194; xxv, 39; xxvi, 143. 


Phelps and Tillotson, Jr.—Cyanacetie Acid. 265. 


This acid, when neutralized with ammonium hydroxide, gave 
no precipitate with lead nitrate, indicating that no malonic or 
glycollic acid was present, and on analysis proved to be pure. 


I. 0:4000 grm. gave 59°5°™* moist nitrogen at 25° and 756°8™™. 
IN’== 16". percent. 
II. 0:2910 grm. gave 43°1™* moist nitrogen at 25° and 762°1™™. 
N = 16°57 per cent. j 
Required for C,H,O, N, N = 16°48 per cent. 


The alcohol was made as anhydrous as possible by repeated 
distillations over calcium oxide. For experiments (2) to (5) 
inclusive, absolute alcohol obtained as described above was 
charged with dry hydrochloric acid gas in the proportions of 
ten grams of hydrochloric acid per liter of alcohol. Pure zine 
chloride of commerce, freshly fused, and sulphuric acid, sp. 

r. 1°84, were used also as catalyzers. 

In all of the experiments recorded in the table, fifty grams 
of cyanacetic acid with 40°™* of alcohol, alone or charged with 
hydrochloric acid in the proportions already given, together 
with a definite weight of zine chloride or sulphuric acid, 
were heated to a temperature of 100°-110°, using the special 
arrangement of flasks for esterification and the procedure for 
recovery of the pure ester, described in a former paper.* 

The error inherent in the process was determined by treat- 
ing 70 grm. of pure cyanacetic ester with 4 grm. of sulphuric 
acid and alcohol in the esterification apparatus, under the 
same conditions as in the several experiments, and recovering 
in the same manner. Under these conditions 68°33 grm. were 
recovered. Thus the results shown in the table must be 
approximately 2°5 per cent lower than the amounts of cyan- 
acetic ester actually formed. 

From experiment (1) it appears that with absolute alcohol, 
using no catalyzer, 63°5 per cent of cyanacetic ester may be 
obtained, but if the alcohol be charged with 1°25 per cent of 
hydrochloric acid, as in experiment (2), the yield is increased 
25 per cent. In experiment (3) the addition of one gram of 
zine chloride raises the yield one per cent over that of experi- 
ment (2) where no zinc chloride was used, and the presence 
of 10 grm. of zine chloride further increases the yield to 95-1 
per cent of cyanacetic ester actually obtained. In all the experi- 
ments in which alcohol charged with hydrochloric acid was 
used, a small amount of ammonium chloride, possibly 0°1 grm., 
separated during the treatment at 100°-110°, showing partial 
conversion to malonic ester. In experiment (5) no ammonium 
chloride was observed when the esterification was performed 
at 85°-90°, but under these conditions the yield of cyanacetic 


* This Journal, xxiv, 194. 


Am. Jour. Sci.—FourtH Series, Vou. XXVI, No. 153.—SEPTEMBER, 1908. 
19 


266 Phelps and Tillotson, Jr—Cyanacetic Acid. 


ester was much lower. Similarly, in experiments (6), (7), and 
(8) in which sulphuric acid and absolute aleohol were used, 
no ammonium salt was precipitated and the ester obtained was 
evidently pure ethyl cyanacetate. In experiment (6) half a 
gram of sulphuric acid produces an increase of 31 per cent 
over experiment (1) in which conditions were the same, except 
that no catalyzer was present. Two grams of sulphuric acid 
in experiment (7) further increases the yield to 96-6 per cent, 
and by increasing the time to two hours, as in experiment (8), 
97-1 per cent of cyanacetie ester was obtained. Taking into 


consideration the 2°5 per cent loss inherent in the process, it | 


seems probable that the cyanacetic acid was completely esteri- 
fied under the conditions imposed in experiment (8). 

The work recorded here has shown that, using alcohol alone, 
with no catalyzer, 63 per cent of eyanacetic ester may be easily 
obtained, that the yield is increased by the use of catalyzers 
and, within limits, increases with the amount of catalyzer used. 
Increasing the time, as shown in one experiment, also causes a 
more complete esterification. The use of alcohol containing 
only 1:25 per cent of hydrochloric acid causes a partial con- 
version to malonic ester at 100°-110°, while with sulphuric 
acid as a catalyzer this reaction apparently does not take place. 
Ksterification is more complete. when sulphuric acid and abso- 
lute alcohol are used instead of zine chloride and alcohol 
charged with hydrochloric acid, and nearly theoretical yields 
may be obtained by using two grams of sulphuric acid with 
200° of absolute alcohol acting for a period of two hours. 
Hence, in the preparation of cyanacetie ester, hydrochloric 
acid may not be used if the temperature is above 100°. If 
the temperature is lower and if the concentration of the hydro- 
chloric acid is also low, presumably pure cyanacetic ester may 
be obtained, but such conditions are neither the best nor the 
most convenient. Sulphuric acid may, however, be used and 
pure cyanacetic ester obtained, and that in theoretical amount 
if proper proportions of reagents and proper conditions as to 
temperature and time of action are employed. 


Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 267 


Art. XXIX.—On the Preparation of Malonic Acid or its 
Ester from Monochloracetic Acid ; by I. K. Puetps and 
E. W. Tiruotson, JR. 


[Contributions from the Kent Chemical Laboratory of Yale University— 
elxxxv. | 


Korseg,* starting with chloracetic acid, Millert and Finkel- 
steint, with chloracetic ester, and Franchimonts, with brom- 
acetic ester, have shown that, by acting on the above-named 
derivatives of acetic acid with potassium cyanide, and subse- 
quently treating with potassium hydroxide, potassium malo- 
nate is formed. They give no data showing the yield of 
malonie acid obtainable under the conditions of experimenta- 
tion. Von Miller! treated potassium chloracetate with potas- 
sium cyanide, boiled with potassium hydroxide, saturated with 
hydrochloric acid, evaporated to dryness, and extracted with 
ether. From 100 grm. of monochloracetic acid he obtained 75 
erm. of malonie acid, or 70 per cent of that theoretically pos- 
sible. Conrad followed a similar procedure except that 
instead of evaporating to dryness, he precipitated the calcium 
malonate. ‘The ester was prepared by saturating a mixture of 
calcium malonate and absolute alcohol with hydrochloric acid, 
distilling off the alcohol, washing the ester with a solution of 
sodium carbonate, and drying over calcium chloride. <A yield 
of 63 per cent of that theoretically possible from the amount 
of chloracetic acid used was obtained by this method. Grimaux 
and Tcherneak** and later Bourgoin,tt after acting on sodium 
or potassium chloracetate with potassium cyanide, saturated 
the water solution with gaseous hydrochlorie acid, evaporated 
to dryness and extracted the malonic acid with ether. The 
earlier paper reports a yield of 34 per cent, the later one of 
64 per cent of the theoretical amonnt of malonic acid. Claisen 
and Venable{+ evaporated the aqueous solution of potassium 
cyanacetate, first obtained, until the temperature reached 135°, 
pulverized the mass, added alcohol and saturated the mixture 
with gaseous hydrochloric acid. The product was poured into 
water, extracted with ether, and the ethereal solution dried 
over calcium chloride. By this procedure 55 per cent of the 
theoretical amount of malonic ester was obtained. Noyes§§ 
treated the pulverized mass of salt, obtained as described above, 
with a mixture of equal parts of alcohol and sulphuric acid and 
boiled under a return condenser, added a solution of sodium 


* Ann., cxxxi, 348. + Ann., cxxxi, 250. 
¢ Ann., cxxxiii, 338. § Berichte, vii, 217. 
| Jour. prakt. Chem. [2], xix, 326. 4| Ann., eciv, 121. 

** Bull. Soc. Chim., xxxi, 338. t+ Ibid., xxxiii, 572. 


tt Ann., cexviii, 131. §§$ Jour. Am. Chem. Soc., xviii, 1105. 


268. Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 


Malonic ester 


Chloracetic Potassium Tempera- a 


acid cyanide ture of Theory Found Per 
No. grm. grm. reaction grm. ma Sern cent 
A 
(1) 200 175 110° 338°'8 264°77 78°2 
(2) 200 165 110° 338°8  -.295°738 87°3 
(3) 200 165 90°-95° . 338°8 293°14 86°5 
(4) 200 165 90°-95° 338°8 285°24 84°2 
(5) 200 165 90°-95° 338°8 295°26 Sital 
B 
(1) 200 165 90°—95° 338°8 | 295°76 87°3 
(2) 200 165 90°-95° 338°8 297°49 87°8 
C 
(1) 200 16D er pet eel O> 338°8 _ 296°24 87-4 
(2) 200 165 90°-95° 338°8 292°65 86°3 


carbonate and extracted the malonic ester with ether. The 
ether was distilled off, and the ester fractioned under diminished 
pressure. By recovering and esterifying the acid ester from 
the sodium carbonate solution, he obtained a weight of malonie 
ester equal to that of the chloracetic acid employed, or about 
60 per cent of that theoretically possible. 

In an earlier paper* in this Journal, the best conditions for 
the esterification of malonic acid were studied. In a later 
papert a study of the conversion of cyanacetic ester to malonic 
ester was reported. In preparing material for use in those 
papers the synthesis from chloracetic acid was employed. It 
seemed worth while to study these syntheses further and apply 
the results of the two earlier papers to the practical prepara- 
tion of malonic ester. This paper reports the results of such 
a study. 7 

For the work described in this paper, impure commercial 
monochloracetic acid was twice fractionally distilled at atmos- 
pheric pressure, using portions boiling within limits of one to 
one and one-half degrees. The acid obtained in this manner 
was found to be about 95 per cent pure as shown by the fol- 
lowing analyses, made according to Carius: 


I. 0:1808 grm. of acid gave 0°2608 grm. of silver chloride. 
Cl=35°64 per cent. 
II. 0:0939 grm. of acid gave 0:1347 grm. of silver chloride. 
Cl=35°47 per cent. 
Calculated for C,H,O,Cl, Cl=37'53 per cent. 


* This Journal, xxvi, 143. + Ibid, xxvi, 257, 


Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 269 


Potassium cyanide of 96-98 per cent purity was used for 
the experiments in series A of the table. For those of series 
B, pure commercial cyanide containing ammonia, and for 
those of series C, pure commercial potassium cyanide free 
from ammonia and cyanate was employed. Ananalysis of the 
sample used in the experiments in series C gave the following 
results. 


I. 02372 grm. of potassium cyanide gave ‘4579 grm. of silver 
eyanide. CN=37'50 per cent. 
II. 0°2682 grm. of potassium cyanide gave ‘5198 grm. of silver 
cyanide. CN =87-65 per cent. 
Calculated for KCN, CN=39°95 per cent. 


The aleohol made use of in the conversion to malonic ester 
and that employed in the process of esterification was alcohol 
of commerce, made as free from water as possible by repeated 
distillations over calcium oxide. 

In all the experiments in the table, except those specially 
treated, 200 grm. of monochloracetic acid, contained in a liter 
flask, was treated with about 300 germ. of pure hydrous sodium 
carbonate of commerce, and 50°* of water added to start 
the reaction. Good results were obtained, in experiments not 
recorded, using the anhydrous sodium carbonate dissolved in 
250°" of water. The advantage in the use of the hydrous salt 
les in the fact that the solution of sodium chloracetate is kept 
cold during the process of neutralization, thus keeping the 
hydrolysis of the chloracetate at a minimum. In fact, under 
the above conditions, a temperature low enough: to freeze the 
mass is nearly always obtained. It is usually convenient to 
hurry the reaction by standing the flask in water at room tem- 
perature. In experiment (1) of series B, potassium carbonate 
was used instead of sodium carbonate, but there appeared to 
be no advantage in its use, since the potassium sulphate 
formed on acidifying with sulphuric acid was not less soluble 
than sodium sulphate under the conditions of experimentation. 
When the chloracetic acid was entirely neutralized, the solu- 
tion was poured into a solution of 165 grm. of potassium 
eyanide in 250™* of water heated to 70—-80°, and after the 
vigorous action had taken place, the solution was boiled for 
about five minutes to complete the reaction. The solution 
was then cooled and acidified with sulphuric acid, using the 
action of a drop of the liquid with logwood paper as a test of 
acidity. About 100™* of concentrated sulphuric acid were 
required for each experiment. After cooling the precipitated 
salt was filtered off and the water solution evaporated to dry- 
ness. In experiment (1) of series A, this was done at the 
temperature of the steam bath. In the remaining experiments 


270 Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 


of the table, it was accomplished under diminished pressure ~ 
by heating the flask in a water bath at 70-80°, collecting the 
distillate in a side-necked receiver which was kept cool by a 
stream of water flowing over it continuously. The salt which 
had been filtered off from the water solution was shaken up in 
a flask with 200° of 95 per cent alcohol, filtered, and the 
salt washed on the filter with 100™* of alcohol of the same 
strength. These aleoholic solutions were then added to the 
residue, obtained by evaporation of the water solution, warmed 
in a water bath and shaken till homogeneous. The insoluble 
salt was filtered off, shaken up again with 100—200°™ of hot 
95 per cent alcohol, and again filtered. The combined alco- 
holie solutions contained in a liter flask were then freed from 
alcohol, water, and low-boiling products by heating under 
diminished pressure with a water bath at 60°, collecting the 
distillate as before. The residue, consisting chiefly of cyan- 
acetic acid, cyanacetic ester, and some sodium or potassium 
salt, was treated by the method described in a former paper* 
for the conversion of cyanacetic ester to malonic ester. For 
these experiments, 600°° of absolute alcohol with 5™ of 
sulphuric acid, sp. gr. 1°84, were placed with the product 
obtained as described above, in a two liter flask fitted with a 
reflux condenser.and kept cool in a mixture of ice and salt, and 
the solution saturated with gaseous hydrochloric acid, dried 
by bubbling through concentrated sulphuric acid. At the end 
of about twelve hours saturation was usually complete. The 
ice mixture was then replaced by a water bath and the solution 
boiled under the return condenser for two hours, passing the 
eurrent of hydrochloric acid through the mixture continuously. 
The precipitated ammonium salt was then filtered off, shaken 
up with 100°™ of absolute alcohol, filtered again and washed 
with absolute alcohol. The alcoholic solutions were then 
collected in a liter flask fitted for esterification, as described 
in a former papert from this laboratory, and 700%™* of abso- 
lute alcohol distilled during a period of three to four hours 
through the solution of ester, which was kept at a temperature 
of 100-110°. The resulting product was purified by treating 
with ice and a solution of sodium carbonate and shaking out 
with ether. The ether and all low-boiling products were then 
removed and the pure malonic ester distilled under diminished 
pressure, as described in the paper to which reference has 
been made. The ester obtained in this manner boiled within 
reasonable limits and was nearly pure ethyl malonate. 
Further evidence of its purity is furnished by the fact that, on 


* This Journal, xxvi, 145. + This Journal, xxiv, 194. 


Phelps and Tillotson, Jr.—Matonie Acid or its Ester. 271 


hydrolysis of the fractionated material, pure* malonic acid 
was obtained. 

In experiments (8), (4) and (5) im series A, (1) and (2) in 
series B, and (2) in series O of the table, the reaction between 
the sodium chloracetate and potassium cyanide was made to 
take place at a temperature of 90°—95°, by allowing the cold 
solution of chloracetate to run slowly from a separatory funnel 
into the hot cyanide solution, an operation which took from 
fifteen to twenty minutes. In the other experiments the two 
solutions were mixed and the reaction allowed to take place 
vigorously, the temperature under these conditions reaching 
110°. It was noticed in this reaction that if the chloracetate 
solution was distinctly alkaline a nearly colorless solution re- 
sulted, while if acid considerable color developed. The amount 
of color seemed to increase with the length of time of the 
reaction. Thus when the solutions were mixed and a vigorous 
action took place, less color resulted than when the reaction 
went at 90°—95° for fifteen minutes, but even then the color- 
ation was small in comparison to that formed in experiments 
not recorded in the table, in which the reaction was made to 
take place at the temperature of ice water during a period of 
twelve hours. The color is possibly due to dark-colored poly- 
meric products formed from hydrocyaniec acid. Hence it is 
advantageous to allow the reaction between potassium cyanide 
and sodium chloracetate to proceed in alkaline solution at a 
temperature of about 100°. But these conditions are favorable 
for the conversion of the cyanacetate to a malonate, which is 
to some extent decomposed in the hot alkaline solution as shown 
by Van’t Hoff,t who explained the decomposition as taking 
place according to the following equation: CH,(COOK), + 
KOH = CH,COOK + K,CO,. For this reason prolonged 
boiling after the reaction is over is not desirable. On acidi- 
fying, the slight excess of sulphuric acid produces a small 
amount of hydrochloric acid, which, in the process of evapo- 
ration of the aqueous solution of cyanacetic acid, may also 
cause the formation and decomposition of some malonic acid. 
This is shown in experiment (1) of series A, in which the acid 
solution was evaporated on a steam bath. When the volume 
of liquid became small, decomposition was apparent, through 
the escape of bubbles of carbon dioxide. This decomposition 
was minimized in all the remaining experiments, except exper- 
iment (4) of series A, by evaporating at a lower temperature, 
under diminished pressure. In order, if possible, to entirely 
prevent this decomposition through the hydrolyzing effect of 
the strong acid, the excess of sulphuric acid was removed, in 


* This Journal, Phelpsand Weed, xxvi, 138. + Berichte, vii, 1382, 


272 Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 


the case of experiment (4) of series A, by adding a solution of 
sodium acetate in excess, testing the disappearance of acidity 
of the solution with logwood paper. The slightly lower yield 
would indicate that sodium cyanacetate had been formed from 
the sodium acetate and the free cyanacetic acid present. 

Some loss always occurred during the distillation of the 
aleohol from the alcoholic solution of cyanacetic acid. The 
alcoholic distillates, averaging 500™*, from five experiments 
not recorded in the table but made by the procedure described, 
were separately distilled through a Hempel column to small 
volume and the remainder heated at 60°, under diminished 
pressure, till the manometer registered 15"™. The weighed 
residues were combined and esterified. From the weight of 
eyanacetic ester so obtained it was found that when 500% of 
aleohol, containing some water, were distilled at 60° under 
diminished pressure, from a solution containing about 180 grm. 
of cyanacetic acid, there also distilled 7-1 grm. of cyanacetic ester, 
which is equivalent to 10 grm. of malonic ester, or three per 
cent for each experiment. It has been shown in a former 
paper* that the loss of malonic ester, inherent in the process 
employed for the conversion of cyanacetic ester to malonic 
ester, was about three grams for seventy grams of malonic 
ester, or 4°3 per cent. If these constant losses be considered, 
it is evident that the results shown in the table are approxi- 
mately 7°3 per cent lower than the amount of malonie ester 
which would have been obtained had there been no loss during 
the process. | | 

From the experiments in series A, in which potassium 
cyanide of 96-98 per cent purity was used in excess, the results 
are as good as those in series B, in which pure cyanide of 
commerce containing ammonia was employed, and even as 
good as those in series C, in which cyanide free from ammo- 
nia and cyanate was made use of, other conditions being the 
same. Thus it would seem that if the potassium cyanide is in 
excess, impurities in the cyanide to the extent of three or four 
per cent do not materially affect the reaction with sodium 
chloracetate. 

In experiment (2) of series C there was much evolution of 
carbon dioxide when sodium carbonate was added in the pro- 
cess of recovery of the pure ester. This was presumably due to 
the excess of sulphuric acid which was added previously to lib- 
erate the cyanacetic acid. Too large an excess is not desirable, 
as it retards esterification, either by holding back water or by 
forming water and ethyl ether in reacting with alcohol at the 
temperature 100°-110°, at which esterification took place. The 
slight variations in yield among otherwise similar experiments 
may be due to variations in the excess of sulphuric acid present. 


* This Journal, xxvi, 260. 


Phelps and Tillotson, Jr.—Malonic Acid or its Ester. 273 


From the work recorded here it is evident that the reac- 
tion between potassium cyanide and sodium chloracetate to 
form sodium cyanacetate proceeds best in alkaline solution. 
This reaction may take place vigorously at 110° or slowly at 
90°-95° without materially affecting the yield of malonic ester. 
For the best results the alkaline solution of sodium cyan- 
acetate should not be evaporated to dryness at a high tem- 
perature or even boiled for a long time, since these conditions 
are favorable for the formation and decomposition of the 
sodium malonate formed. The aqueous solution of cyanacetic 
acid is best evaporated to dryness under diminished pres- 
sure at a temperature of 70°-80°, and the alcoholic solution 
at about 60°. In removing the alcohol under diminished pres- 
sure there is a constant loss equivalent to three per cent of 
malonic ester, and in the process employed for converting the 
eyanacetic ester to malonic ester and recovering the latter in 
pure form, there is an additional loss of 4°3 per cent. If 
these losses be considered we have, in the case of the sev- 
eral higher results shown in the table, from 94°3 to 95-1 per 
cent of the theoretical amount of malonic ester accounted 
for. Further, if we take into account that the chloracetic 
acid employed was but 95 per cent pure, as shown by anal- 
ysis, it seems that the results given are from 99:3-100 per 
cent of the theoretical amount for the chlorine content of 
the chloracetic acid used. That is to say, potassium cyanide 
and sodium chloracetate, in alkaline solution at about 100°, 
react to give a theoretical amount of sodium cyanacetate and 
potassium chloride. Or, again, the theory for malonic ester 
obtained from 200 grm. of monochloracetic acid of 95 per cent 
purity is 321-8 grm. and the yields actually obtained, leaving 
out of account experiments (1) and (4) of series A, average 
295°18 grm. or 91°7 per cent instead of 87-1 per cent in the 
table, in which the theory is calculated on the basis of pure 
monochloracetic acid. 

Thus malonic ester in large quantities may be made in nearly 
theoretical amount from monochloracetic acid if the procedure 
as outlined above be followed. The essential points are, an 
excess of potassium cyanide, reacting in alkaline solution ; the 
addition of sulphuric acid to the solution of sodium cyan- 
acetate in only slight excess; the evaporation of the aqueous 
and alcoholic solutions of\cyanacetic acid at low temperature, 
which is most readily done under diminished pressure; the 
conversion to malonic ester and the purification of the same by — 
the procedure described above. Under these conditions, if the 
chloracetic acid be only 95 per cent pure, about 87 per cent of 
the theoretical amount of malonic ester may be obtained, or 


274 Phelps and Tillotson, Jr—Matonic Acid or its Ester. 


figuring it on the chlorine content of the chloracetic acid, about 
92 per cent, which is an improvement of about thirty per cent 
on the best previous methods known to us. 

Pure malonic acid was obtained from ester, prepared in this 
way, for use in an earlier paper* on the esterification of mal- 
onicacid. The ester was fractionally distilled under atmospherie 
pressure with a Hempel column. Portions boiling within two 
tenths of a degree were converted into malonic acid by heating 
equal parts of malonie ester and water with a few drops of 
nitric acid at a temperature of about 60° for some time after 
the mixture had become homogeneous. The solution was then 
evaporated in an open dish at a temperature of about 50° to 
the point of saturation, and the malonic acid which separated 
on cooling was recrystallized from hot water. In this manner 
pure malonic acid may be obtained with only slight loss of 
material. ; 


* This Journal, xxvi, 248. 


Phelps and Tillotson, Jr.— Cyanacetic Acid. 275 


Art. XX X.—On the Preparation of Cyanacetic Acid and 
us Ester from Monochloracetic Acid; by I. K. Puetps 
and E. W. Trittotson, JR. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxiii.] | 


Ko.ze,* in synthetizing malonic acid, states that if the solu- 
tion obtained by acting on chloracetic acid with potassium 
cyanide be acidified with sulphuric acid and extracted with 
ether, cyanacetic acid is obtained, which on boiling with potas- 
sium hydroxide is converted to potassium malonate. Miullert 
obtained cyanacetic ester “boiling above 200°” by treating 
chloracetic ester in alcoholic solution with potassium cyanide. 
Finkelstein{ used chloracetic ester and an aqueous solution of 
potassium cyanide, boiling till all the ester had gone into solu- 
tion, evaporating to dryness, acidifying the residue with hydro- 
ehloric acid and extracting with ether. On evaporation of the 
ether cyanacetic acid was obtained. Meeves§ also acted on 
chloracetic ester with potassium cyanide in a water solution, 
evaporated, acidified with sulphuric acid, and extracted with 
ether. The acid obtained on evaporation of the ether was 
purified by treating with lead carbonate, filtering off the excess 
of carbonate and insoluble lead malonate and decomposing the 
solution of lead cyanacetate with hydrogen sulphide ; but as in 
the case of the other investigators mentioned above, no results 
were given by him showing the amount of cyanacetic acid 
obtainable from a given weight of chloracetic acid. Grim- 
aux and Tcherneak| caused sodium chloracetate and potassium 
eyanide to react, extracted the cyanacetic acid with ether 
according to Meeves’ procedure and obtained about 75 per 
cent of the theoretical amount of cyanacetic acid. Van’t 
Hoff] states that. he obtained a nearly theoretical yield from 
chloracetic acid, but gave no definite information as to how it 
was obtained. Fiquet** followed in general the same procedure 
as Grimaux and Tcherneak, acidifying with hydrochloric acid 
instead of sulphuric acid, and obtained 70 per cent of that theo- 
retically possible. Noyes, ++ after boiling chloracetic ester and 
potassium cyanide with methyl alcohol, obtained 50 per cent 
of the theoretical yield of eyanacetie ester, boiling within 
limits of ten degrees. 

In a former paper{t{ it has been shown from the amount of 
malonic ester obtained that sodium chloracetate and potassium 


* Ann., cxxxi, 348. +Ann., cxxxi, 350. 
tAnn., cxxxiii, 338. § Ann., cxliii, 201. 
|| Bull. Soc. Chim., xxxi, 338. “| Berichte, vii, 1382. 


** Jour. Am. Chem. Soc., xxvi, 1545. 4 Ann, Chim. [6], xxix, 439. 
tt This Journal, xxvi, 267. 


276 Phelps and Tillotson, Jr.—Cyanacetic Acid. 


Cyanacetic ester 


—_ __ 


Chlorace- Potassium Temperature = —— 


tic acid cyanide of reaction Theory Found He 
No. grm. grm. erm. erm. Per cent. 
A | 
(1) 200 165 90°-95° 239°4 219°78 91°4 
(2) 200 Gop =< 1 LOe 239°4, 224°15 93°6 
(3) 200 165 110° 239°4 222-00 92°7 
(4) 200 165 110° 239°4 220°00 91°9 
B 

(1) 200 165 0°-5° 239°4 213°30 89°1 
(2) 200 165 90°-95° 239°4 2NSe7 2 91°4 
(3) 200 165 90°-95° 239°4 220°04 91°9 
4) 9200 165 110° 239'4 207°68 86°8 
(5) 200 165 110° 239°4 206°63 85°1 


eyanide react in alkaline solution at 100° to form the theoreti- 
cal amount of sodium cyanacetate. The work recorded in 
this paper is a study of the formation of ethyl cyanacetate 
from monochloracetic acid, making use of the best conditions 
for the esterification of cyanacetic acid as described in an 
earlier paper® in this Journal. | 

For the work described in this paper the impure monochlor- 
acetic acid of commerce was fractionally distilled twice at 
atmospheric pressure, using portions boiling within limits of 
one and one-half degrees. The acid so obtained was found, by 
analysis given in a former paper,ft to be about 95 per cent pure. 
Commercial potassium cyanide of 96-98 per cent purity was 
used in all the experiments. The alcohol employed in esteri- 
fication of the cyanacetic acid was made as free as possible 
from water by repeated distillations from calcium oxide. 

In all the experiments except those in which the treatment 
was special, 200 grm. of monochloracetic acid of the purity 
described above, was treated in a liter flask with about 300 
grm. of hydrous sodium carbonate and 50° of water to start 
the reaction. The temperature of the mass usually became so 
low that the mixture was frozen. The action may be hastened 
by immersing the flask in water at room temperature. Good 
results were also obtained by using about 110 grm. of anhy- 
drous sodium carbonate and 250™* of water, but since the 
reaction with the hydrous carbonate takes place with cooling, 
there is less tendency towards hydrolysis of the chloracetate. 
The alkaline solution of sodium chloracetate was then poured 
into a hot solution of 165 grm. of potassium cyanide in 250° 
of water and after the action had taken place the solution was 
boiled for five minutes to complete the reaction. To the 
cooled solution was then added sulphuric acid in slight excess, 


* This Journal, xxvi, 264. + This Journal, xxvi, 268. 


Phelps and Tillotson, Jr.— Cyanacetic Acid. 277 


using a drop of the solution with logwood paper as a test of 
acidity. The precipitated salt was then filtered off and the 
water distilled from the cyanacetic acid and other non-volatile 
material under diminished pressure by heating the flask in a 
water bath at 70°-80° and collecting the distillate in a side- 
necked flask as a receiver, which was kept cool by allowing a 
stream of water to flow over it continuously. The salt which 
remained on the filter was washed with 300™* of 96 per cent 
alcohol, and the alcoholic solution added to the cyanacetic acid 
residue remaining after the aqueous solution had been distilled 
under diminished pressure. The mixture was well shaken, 
filtered, and the salt shaken up with 100°™* of alcohol of 96 
per cent strength, filtered and washed with alcohol. The com- 
bined alcoholic solutions were then evaporated under dimin- 
ished pressure, heating the flask in a water bath at 50°-60° 
and collecting the distillate as before, continuing distillation 
till the manometer showed 15™™ pressure, to insure removal of 
all the water. To the residue, which consisted chiefly of cyan- 
acetic acid and its ester, was added 100°™ of absolute alcohol 
and 5° of sulphuric acid, sp. gr. 1°84. Then the mass was 
esterified at 100°-110° for 2°5 to 3 hours with 500°™* of absolute 
alcohol, using the special arrangement of flasks for esterifica- 
tion described in a former paper* from this laboratory. The 
crude product was then purified by treating with ice and a 
solution of sodium carbonate and shaking out with ether. 
The ethereal solution. was then freed from low-boiling pro- 
ducts and distilled under diminished pressure in the usual 
manner. 

In experiment (1) of series B, the potassium cyanide and 
sodium chloracetate were made to react in the cold, the flask 
standing in ice water for twelve hours. In experiments (1) of 
series A, and (2) and (3) of series B, the cold alkaline solution 
of chloracetate, contained in a separating funnel, was slowly 
run into the hot solution of potassium cyanide. The time 
employed was fifteen to twenty minutes and the temperature 
was kept at 90°-95° by the heat of the reaction. In the other 
experiments of the table the two solutions were mixed immedi- 
ately and the action allowed to take place vigorously, the 
temperature being usually about 110°. It has been shown in 
the former paper to which reference has been made, that this 
reaction proceeds more smoothly in an alkaline solution at a 
temperature of about 110°, but these conditions are unfavorable 
for the production of pure cyanacetic acid or ester, since 
cyanacetates are converted to malonates in hot alkaline solution. 
For this reason prolonged boiling after the reaction is over is 
not desirable. On acidifying, the slight excess of sulphuric 


* This Journal, xxiv, 194, 


278 Phelps and Tillotson, Jr.—Oyanacetie Acid. 


acid acting on the chlorides present produces a small amount 
of hydrochloric acid, which, in the process of evaporation, also 
tends to the formation of malonic acid. In series A there was 
a slight excess of sulphuric acid in each experiment. The ester 
obtained, after fractioning under diminished pressure, appeared 
to contain malonic ester as shown by the following analyses: 


I. 0°5060 grm. of ester gave 51°5°™* of moist nitrogen at 21° and 
762°6"™, ( N = 11°39! per'cent | | 

II. 0°5070 grm. of ester gave 51:2°™* of moist nitrogen at 22° and 
M65 2B OS Nas 152 percent. | 

Calculated for C,H,O,N, N = 12°40 per cent. 

In the experiments of series B, after adding a slight excess of 

sulphurie acid, as indicated by logwood paper, enough of a 

saturated solution of sodium acetate was added to destroy the 

excess of sulphuric acid, logwood paper again being the indi- 

cator. ‘The ester obtained in this manner, after being fractioned 

under diminished pressure, gave the following analyses: 


I. 0°5020 grm. of ester gave 55:2°™ of moist nitrogen at 23° and 
762-30m oN 2747 per cent. 
II. 0°5004 grm. of ester gave 55°0°™ of moist nitrogen at 20° and 
150; 2 aN) = 2no 4 per cent.) 
Calculated for C,H,O,N, N = 12°40 per cent. 


It is plain therefore that if pure cyanacetic ester is to be 
obtained, the water solution of cyanacetic acid must not be 
evaporated in the presence of mineral acids, but in the presence 
of acetic acid no considerable decomposition takes place. The 
operation is most conveniently performed under diminished 
pressure, since the low temperature necessary to remove the 
water under diminished pressure is unfavorable for the forma- 
tion of malonic acid. 

Some loss always occurred during the distillation of the 
alcoholic solution of cyanacetic acid. This loss has been shown 
in the former paper,* on the preparation of malonic ester, to be 
71 grm. of cyanacetic ester or about three per cent. It has 
also been shown in a former paper,ft that the loss herent in 
the process used for recovery of pure ester from the crude 
product obtained in the esterification flask was 1:67 grm. for 
70 grm. of pure ester or 2:4 per cent. Assuming that this 
percentage error holds for large amounts, we have approxi- 
mately 5-4 per cent of cyanacetic ester lost during the pro- 
cedure. 

In an earlier papert it was shown from the yield of malonic 
ester obtained that if the purity of the chloracetic acid used and 
the loss of malonic ester inherent in the process be taken into 


*This Journal, xxvi, 272. + This Journal, xxvi, 265. 
+ This Journal, xxvi, 273. 


Phelps and Tillotson, Jr.—Cyanacetic Acid. 279 


account, the reaction between sodium chloracetate and potas- 
sium cyanide was practically quantitative. It is therefore 
possible to calculate from the amount of malonic ester obtained 
from the chloracetic acid used, the amount of cyanacetic ester 
which might be expected from 200 grm. of the same quality of 
ehloracetic acid. A series of seven experiments similarly 
carried out gave an average of 871 per cent of malonic ester, 
with a loss inherent in the process of converting the cyanacetic 
to the malonic ester of 4:2 per cent. This gives 309-32 grm. 
of malonic ester, which is equivalent to 218°57 grm. of cyanacetie 
ester from 200 grm. of chloracetic acid. The loss sustained by 
the process employed for the recovery of the ester from the 
crude product obtained in the esterification flask, has been shown 
in a former paper®* to be 1°67 grm. for 70 grm. of cyanacetic 
ester, and is presumably 5 grams for the 218°57 grm. under 
consideration in these experiments. Thus if the ester formed 
is pure ethyl cyanacetate, we should not expect to obtain more 
than 213°57 grm., and higher yields may be explained by the 
conversion of some of the cyanacetic ester into malonic ester. 
This explanation is supported by the analyses, given above, of 
the ester obtained in experiment (2) of series A, and appears 
justified since in the experiments of series A there was an 
excess of sulphuric acid while the aqueous solutions of cyan- 
acetic acid were being evaporated to dryness. The higher 
yields obtained in experiments (2) and (8) of series B are 
ascribed to the formation of sodium malonate from sodium 
eyanacetate in the hot alkaline solution. In these experiments 
the reaction took place slowly for a period of fifteen to twenty 
minutes, which allowed more hydrolysis to take place than in 
experiments (4) and (5) of series B, in which the action was 
over in five minutes or less. The lower results in experiments 
(4) and (5) of series B are explained on the assumption that the 
cyanacetic acid, reacting with the excess of sodium acetate, 
forms an equilibrium mixture and, since the sodium cyanacetate 
is not dissolved by the alcohol, a loss occurs. 

The results of the work here described are in agreement with 
those of a former paper, which show that potassium cvanide and 
sodium chloracetate react quantitatively in alkaline solution at 
110°. They also show that cyanacetic ester of high purity may 
be prepared in large amounts, and in good yield, from mono- 
chloracetic acid if precautions be taken to minimize the trans- 
formation to malonic acid. To this end the reaction between 
sodium chloracetate and potassium cyanide should take place 
quickly, the alialine solution of sodium cyanacetate should not 
be boiled for a long time, and the solution of cyanacetic acid, 
containing an excess of mineral acid, must not be evaporated 


* This Journal, xxvi, 264. 


230 Phelps and Tillotson, Jr.— Cyanacetic Acid. 


to dryness at a high temperature. However, it may be quickly 
and conveniently evaporated by heating with a water bath at 
70°-80° under diminished pressure, in which case the cyan- 
acetic ester formed is of 90-95 per cent purity. Experiments 
(2), (8) and (4) of series A were performed under such condi- 
tions. If pure cyanacetic ester is to be obtained, the excess of 
mineral acid must be removed by adding sodium acetate. In 
this case the yield is not so good, but the ester, after fractioning 
under diminished pressure, is pure ethyl cyanacetate. This 
‘procedure was followed in experiments (4) and (5) of series B. 

Pure cyanacetic acid was obtained from the ester prepared 
in this way for use in an earlier paper* on the esterification of 
cyanacetic acid. Two parts of water with one of ester and a 
few drops of nitric acid were heated at a temperature of about 
60° for some time after the mixture had become homogeneous. 
The solution was then evaporated in an open dish, at a tem- 
perature of 50°—60°, to the point of saturation. The cyanacetic 
acid which separated on cooling was recrystallized from a mix- 
ture of ether and chloroform. In this manner pure cyanacetic 
acid, melting at 66°1°-66°4° (corrected), was obtained in quantity 
and in good yield. 


* This Journal, xxvi, 264. 


Phelps and ELddy—fydrobromie Acid. 281 


Art. XXXI.— Researches on the Influence of Catalytic 
Agents in Ester Formation. Hydrobromic Acid and 
Zine Bromide in the Formation of Ethyl Benzoate ; by 
I. K. and M. A. Puetrs and EK. A. Eppy. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxvii. | 


Gotpscamipt® has measured the rate of esterification of ben- 
zoic acid with ethyl alcohol, using hydrochloric and hydrobro- 
mic acids as catalyzers. The results in the use of these two 
catalytic agents for a temperature of 25° are so nearly the 
same that he concludes that hydrochloric and hydrobromic 
acids under the conditions of his experiments have the same 
efficiency as catalytic agents in ester formation. Goldschmidtt 
and many others, from similar physico-chemical measurements 
given in recent literature, have concluded that the efficiency of 
a given catalyzer depends upon the concentration of the cata- 
lyzer and upon the degree of dissociation of the catalyzer in 
alcoholic solution. 

The amount of ester formed from benzoic acid in presence 
of sulphuric acid, or hydrochloric acid, or hydrochloric acid 
and zine chloride as catalyzers, with different amounts of ethyl 
alcohol acting for different lengths of time, has been shown in 
a former papert{ in this Journal. The esterification of the ben- 
zoic acid was made in flasks specially arranged as illustrated 
in an earlier paper§ in this Journal, where the action of zinc 
chloride and hydrochloric acid, as catalyzers, was shown in the 
formation of ethyl succinate. ‘The results given in the paper 
concerning the esterification of benzoic acid show that under 
the conditions of the experiments made, increasing the concen- 
tration of the catalyzers up to a certain limit increases the 
amount of ester produced with a given amount of alcohol acting 
in a given time on a given amount of benzoic acid. Further 
increase in. the amount of catalyzers beyond this hmiting con- 
centration caused a decided falling off in the amount of ester 
produced. And, finally, the results referred to show that the 
yields of ester produced bear no relationship to the degree of 
lonization of the catalyzer. For example, hydrochloric acid 
dissociates to a greater extent than sulphuric acid, but with 
hydrochloric acid as a catalytic agent yields beyond 90-4 per 
cent were not obtained even when a mass of 50 grm. of ben- 
zoic acid was treated with 400° of alcohol containing 25 per 
eent of hydrochloric acid during eight and a half hours, inter- 
polating a fractionation under diminished pressure to remove 
low-boiling products, especially whatever water formed during 

* Berichte, xxviii, 3218. allot 0 le.o.. 40. ear Ip 

t This Journal, xxv, 39. § This Journal, xxiv, 194. 

Am. Jour. Sci.—FourtH Series, Vout. XXVI, No, 153.—SrpremsBer, 1908. 


282 Phelps and Hddy—Hydrobromic Acid. 


esterification that had not been removed under the conditions 
of the experiment, when half of the alcoholic mixture had 
acted upon the acid. It is, however, a striking fact that two 
grams of sulphuric acid with half the amount of alcohol acting 
about one-third of the same time with the same amount of ben- 
zoic acid gives theoretical yields of ester. 

In the work recorded here the catalytic action of zine bro- 
mide and hydrobromic acid at different temperatures on ben- 
zoic acid with ethyl alcohol is brought into comparison with the 
similar action of zine chloride and hydrochloric acid recorded in 
the paper to which reference has been made, as well as in this 

aper. , ? 

: For this work ethyl alcohol was prepared as free from water 
as possible by repeated distillations with calcium oxide. The 
benzoic acid used was the pure benzoic acid of commerce, For 
the preparation of pure, dry hydrobromie acid the pure bro- 
mine of commerce was freed from chlorine by long standing, 
with frequent shaking, in contact with an aqueous solution of 
potassium bromide,* before distilling off the bromine. The 
hydrobromic acid gas was prepared by allowing the purified 
bromine to act on a mixture of red phosphorus and water, the 
gas set free being purified by passing first through layers of 
moist red phosphorus and glass wool contained in one leg of a 
U-tube, the outer leg of which, to dry the gas completely, con- 
tained layers of phosphorus pentoxide and glass wool. The 
hydrobromie acid thus prepared was dissolved in chilled alcohol 
in the concentrations given in the tables. These concentra- 
tions were chosen of such values that the hydrobromie acid in 
these experiments was in molecular proportion to the hydro- 
chloric acid in the experiments to which reference has been 
made. Purezine bromine was prepared for use in two different 
ways. The pure zine bromide of commerce was fused in an 
atmosphere of pure hydrobromic acid before granulating the 
melted zine bromide. Zine bromide was also prepared by heat- 
ing in a flask connected to a return condenser the pure zinc of 
commerce at a temperature above the melting point of zine 
with bromide purified, as described above, for the preparation 
of hydrobromic acid, and then dried with sulphuric acid before 
distillmg. The pure zine bromide made in this way was melted, 
as in the case of the commercial sample, in an atmosphere of 
dry hydrobromic acid, heated to expel any excess of hydrobro- 
mic acid, and then granulated. The amounts of zine bromide 
used corresponded molecularly to the zine chloride used in the 
esterification of benzoic acid in the work to which reference 
has been made. 

In all the experiments given in this paper the procedure was 


* Richards and Wells, Proc. Amer. Acad., xli, 440. 


Phelps and EKddy—Hydrobromic Acid. 283 


similar to that given in the former paper in this Journal on the 
esterification of benzoic acid to which reference has been made. 
In brief the treatment consisted in heating at a definite tem- 
perature a given weight of benzoic acid in the presence of a 
small amount of alcohol with a certain amount of hydrobromic 
or hydrochloric acid, or with an alcoholic solution of hydro- 
bromie or hydrochloric acid, and zine bromide or chloride in 
definite amount. Into this mixture a known amount of alcohol 
and hydrobromic or hydrochloric acid in definite amount was 
driven at a uniform rate in vapor condition. The vapor issuing 
from the flask in which the esterification took place was frac- 
tioned by passing through a Hempel column attached to an 
ordinary condenser. It has been shown in the earlier paper 
that benzoic ester is retained completely in the flask in which 
the benzoic acid is esterified. The ester was isolated in pure 
condition by shaking out the mixture of the crude product with 
ether, treating with sodium carbonate, and distilling under 
diminished pressure in the manner described in the earlier 
work on benzoic ester. 

It appears from an inspection of the results recorded in Table 
I that hydrobromic acid as a catalyzer varies in its efficiency 
according to its concentration, and according to the temper- 
ature at which esterification takes place. This is seen in com- 
paring experiments (1) with (10) and (1) with (5), or (10) with 
(12) and (13). It is also clear that in comparing (8) with (9) 
that the rate of flow of a given amount of alcoholic mixture 
is of influence. A certain amount flowing rapidly is able to 
esterify 10 per cent less benzoic acid than half that amount of 
alcohol even in shorter time, as is seen by comparing (4) with 


TABLE I, 

Ben- Alcohol Time of Benzoic ester 

Zoic with HBr Tempera- action — Se Se = 
No. acid ——*~—-—, ture ——-*~—— Theory Found 

grm. -cm®* per ct. hrs. min. grm. grm. per ct. 
ees 200 2772 785 90" 2° 10>. Gl-48 41-18 66-98 
(2), 50 ZOO TT 90° 1 55 61°48 39°45 64°17 
ap. .90- 7200" 62°77, 100° 2 35 61°48 2930 47°66 
fe) 30 oS 200-277 100 110" 1 AS 61°48. 27-00. 43°92 
(5) ~"50 200g OO 0c ooo 61:48 © 26-40 42:94 
faye 00) 200 2-717 2125 “130, 5 A 55° 61°48) 17°70. 28-79 
(7) 50 200. 227 0e 125 T4053. 29 5 61°48 15°58 25°34 
(8) 50 400 2°77 100° 2 5 61°48 20°31 33°03 
eo). 50 400 2°77 100° 4 25 61°48 35°96 58°49 
Pees 0 20027-74285. 908 2. 6148 56:05 9117 
(11) 50 200 27°74 90°-100° 3 50 61°48 50°96 82°89 
(12) 50 200 27°74 SO N0Omee 2. Gl-48- 575 8ae17 
(13) 50 200 27°74 100° See O48, AI-05 2 O67, 


284 Phelps and EKddy—Hydrobromice Acid. 


(8). In comparing (8) and (9), lengthening the time of action 
of the alcoholic mixtures, other conditions remaining the same, 
increases the amount of ethyl benzoate formed. 

In the results in Table (11), where zine bromide is used as. 
eatalyzer with the hydrobromic acid, no difference was found 
in the amount of benzoic acid esterified by the two samples of 
zine bromide. Itis seen from a comparison of experiments (6) 
with (10) and (12) with (20) that under definite conditions the 
greater the concentration of hydrobromic acid with a given 
amount of zinc bromide present, the greater the amount of 
benzoic acid esterified. When these experiments are compared 
with (1) and (11) of Table I it at once becomes evident that 
zine bromide as well as hydrobromic acid has here a catalytic 
effect. The-greater the amount of either catalyzer present . 
the greater the yield under conditions otherwise closely sim- 
ilar, as is seen in comparing (4), (14) and (24) together, also 
(2) with (12). The largest amounts of zinc bromide used seem 
to retard esterification, as appears when (2) and (12) are com- 


TaBLeE IT. 
Ben- Aleohol Time of Benzoic ester 
ZOIC with HBr Tempera- action ——-H—— —_——— 
No. acid ZnBrz ——--——\ ture —-—— Theory Found 
grm. grm. cm? per ct. hrs. min. grm. STM) sper Cie 
( 1) 50 1:7 200 2:77 °90°-100° 1 85 61:48 (84-73) Siam 
¢ 2) HO Wen BOO Berry 90° 1 50 61°48 36°34 59°19 
(3). 50 1°7 * 200 2°77 100°-150" 2°10 61:48) 25a aimee 
( 4) 50. 1:77 900° 2°77 125°-150> 9°15) 61-48. 2G eee 
( 5) ES Olas Teen AO DASH Tf 100° 2 25 61°48 4245 69°04 
( 6) DOM me 20Ors Dei 5 90° 3 380 61°48 44:06 71°67 
(7) HO Ne SOO Bey 100° ‘ 3 © 61°48 49°76) 76093 
Sin OO Wet SOO. Peart 100°-110° 38 50 61:48 45:05 7aa7 
DON Aa A005 22h 7 100° 2° 8 6148 48 ioeanoaaS 
(10) 50 1st 200 27-74 85° — 90-35. 6 UAe bbe onsen 
Ga) RO AO Bey LOO 1 30 61°48 46°36 75°40 
2) 4 DOG ZOO nm 2rd 100° 2. 10 61:48) AT AG aaa 
cB AO mae 300: 2°77. -90°=100". 4 2 2 61:48. 57-06 acm 
(14) 50 17° 400 2°77 125°-1380° 1 50.6148 41:46 67-44 
(15) 50 17°, A400 2:77) 125°-1357 2 30 16148.) 41¢0a aioe 
(16) DORs. NOON 2 aa, 100° 2 35. 61:48) 5 705g 
Gai ao0) lie ADO B20 4 100° 4 10 3:61:48, -59: 74 oan 
(18) Omeleie 400 2°77 125°-130° 4 45 61:48 | 45-100 7aeans 
(19) 50,17: 200 27°74 90°-100° 1 50 61:48 59°08).9609 
Ai” BO 7 200 27°74 100° 2 5 61°48 . 58° 3G794.06 
ek 5 Omalaie 900 27:74 °85°—-902 3.7.2) 16148) 158°8a aca 
(22) 50. 42°5 200 2°77. -85°— 902.2". 15 {61:48 SI Geet 
(23), 5044 a | 200L M2547 100°-110"7 2° (15 61:48 41 9Saaioeeze 
(24) 50.42°5 200 2°77 120°-150272, 22" 61:48) 240 ine 


= 
= 

j 

a 
= 


Phelps and Eddy— Hydrobromic Acid. 285 


pared with (23), but even with the largest amount, as in 
(23) of Table II, the yield of ester is greater than when no zine 
bromide was used under conditions otherwise similar as in (5) 
and (6) of Tablel. The temperature exerts a decided influence 
here, again, in the presence of different amounts ef zine bro- 
mide, as is seen in experiments (2), (3) and (5) when compared 
with each other, and the same is seen when experiment (15) is 

compared with (16), also when (17)-1s compared with (18). 
The same effect of temperature is not seen when zine bromide, 
as second catalyzer, is present in such large amounts as found 
in experiments (19), (20) and (21) when compared with each 
other, also in (22), (23) and (24) when they are compared with 
each other. The rate of flow of the aleohol seems to have a 
similar influence in presence of the second catalyzer that it had 
in the presence of hydrobromie acid alone. Experiments (2) 
and (6) show that, as do also (16) and (17). 

In Table III are given results which show the action of 
hydrochloric acid either alone as catalyzer, or with zine chlor- 
ide, as a second catalyzer in esterifying at different tempera- 
tures benzoic acid. It is clear from an inspection of results. 
that raising the temperature retards the esterification of benzoic 
acid by means of hydrochloric acid and zine chloride, as it does 
the esterification of benzoic acid by means of hydrobromic acid 
and zinc bromide. In the work for the former paper the influ- 
ence of temperatures as high as 125° was studied. No marked 
effects at this temperature appeared. Attention was called 
there to the difference in esterification produced by varying 
the amount of the eatalyzer, the amount of alcohol, and the 
time of action. 


TABLE III. 

Ben- Aliecohol Time of Benzoie ester 

zoic with HCl Tempera- action —_—s —_—_— 
No. acid ZnCl, ——+~—— ture —-—— Theory Found 

grm. grm. cm? perct. hrs. min. grm. grm. per ct, 
(1) 50 __ 200 1°25 100°-110° 1 40 61°48 87°86 61°74 
(2) ieee 251-25 19s 150° 25 30 61-48 24°45 40-09 
(3) 50 40 200 1-25 100°-110° 2 10 61-48 58°33 94°88 
(4) 50 i0 200 1:25 125°-150° 2 __ 61°48 50°56 82°24 


In all the experiments of Table III, in (4) and (24) of Table 
Ii and in (1) of Table I, the alcoholic distillate was collected in 
four portions and the amount of mineral acid was determined 
in each portion by titrating the diluted distillates with stand- 
ardized sodium hydroxide solution in the presence of phe- 
nolphthalein as an indicator. The amount of mineral acid 
left in the flask from which the alcohol, charged with 
hydrochloric or hydrobromic acid, was distilled, was similarly 


286 Phelps and Hddy— Hydrobromic Acid. 


estimated. The amount of mineral acid left in the esterifi- 
eation flask and neutralized with sodium carbonate in the 
process of recovery of the crude ester in: the experiments (1) 
and (2) of Table III and (1) of Table I was also estimated. 
This was done by acidifying the sodium carbonate wash water 
with nitric acid, the precipitated benzoic acid was filtered off 
and washed with cold water and the halogen acid in the filtrate 
was determined gravimetrically as the silver salt. In experi- 
iment (1) of Table I the total amount of hydrobromie acid in 
the residues was found to be 1°34 grm., of which 0:07 orm. 
was in the alcoholic distillate. In this experiment 4:4 orm, 
of hydrobromic acid were used, leaving 3°06 grm. of hydro-_ 
bromic acid, which pr esumably formed ethyl bromide. In 
experiment (4) of Table II the amount of hydrobromie acid 
found in the alcoholic distillate was 0°0102 grm. In experi- 
ment (24) of Table II the amount of hydrobromic acid found in 
the alcoholic distillate was 0°0048 grm. In diluting the first 
portion of the alcoholic distillate ethyl: bromide was found 
present in such amount as to make the resulting liquid turbid. 

These experiments show first that at a temperature 85°-90° 
about seventy-five per cent of the hydrobromie acid has reacted 
to form ethyl bromide; second, that the hydrobromic acid 
which remains as such accumulates in the esterification flask ; 
and, third, that zinc bromide has a eatalytie effect upon the 
action of ethyl aleohol and hydrobromic acid, as might have 
been anticipated. 

Similarly, in experiment (1) of Table III the total residues 
of hydrochloric acid were found and amounted to 1°84 grm., 
of which 0°110 grm. were found in the alcoholic distillate and 
1-455 erm. in the esterification flask, leaving 0°185 erm. from 
a total of 2-025 grm. of hydrochloric acid taken with the aleo- 
hol, which reacted presumably to form ethyl chloride. In exper- 
iment (2) of Table III the total hydrochloric acid found in all 
residues was 1°485 grm., of which 0°615 grm. was in the alco- 
holic distillate and 0-595 germ. was in the esterification flask, 
leaving 0°54 grm. from a total of 2-025 orm. taken in the aleo- 
holic mixture. In experiment (8) of Table III the hydro- 
chloric acid found in the alcoholic distillate was 0°0019 grm., 
and in (4) of the same table 0-0017 grm. was found in the 
alcoholic distillate. | 

The evidence from these experiments proves that, at a tem- 
perature of 100°-110°, about ten per cent of the hydrochloric 
acid present has reacted to form ethyl chloride. At the higher 
temperature of 125°-150°, a larger amount, about twenty-five 
per cent, is used in this way. With hydrobromic acid of simi- - 
lar concentration, this sort of action, at the lower temperature 
of 85°-90°, goes on to a much larger extent. Thus, in experi- 


Phelps and Eddy— Hydrobromic Acid. 287 


ment (1) of Table I seventy-five per cent of the hydrobromic 
acid has reacted in this way. Further, the efficiency in ester 
formation of hydrobromie acid with or without zinc bromide 
was shown in Tables [and II to be dependent in large measure 
upon the temperature. The difference in the amount of ethyl 
chloride formed at the different temperatures, the large amount 
of ethyl bromide formed under similar conditions of tempera- 
ture with hydrobromic acid, and the variability in the effi- 
ciency of zine bromide at different temperatures, would indicate 
that the failure of zine bromide to act as an efficient catalyzer 
at higher temperature is due to the almost complete action 
of hydrobromie acid on alcohol at that temperature to form 
ethyl bromide and water. The same difference in the effect of 
temperature is evident with hydrochloric acid, as is shown by 
experiments (1) and (2) of Table III, but in these cases the 
action to form ethy] chloride and water makes itself markedly 
evident only at temperatures that are most unsuited for esteri- 
fication. And it seems fair to assume that it is this fact that 
makes hydrochloric acid more advantageous than hydrobromic 
for use as a catalyzer in esterification. 

Presumably it is this difference in catalytic action at differ- 
ent temperatures of hydrobromie acid that explains the differ- 
ence in the results given by Goldschmidt and those recorded 
here. Goldschmidt, measuring the rate of esterification at 25°, 
found hydrochloric and hydrobromie acids equally efficient as 
catalyzers. In our experiments at higher temperatures they 
are never equally efficient. In dilute solutions the hydro- 
chloric acid as catalyzer is much more efticient, while with the 
highest concentrations the hydrobromie acid is more efficient 
if the esterification is carried on at a temperature of 85°—90°. 
At 100°-110° the hydrochloric acid is mueh more efficient, 
and markedly more so than the hydrobromic acid at a temper- 
ature of 125°-150°. While the presence of zine chloride or 
zinc bromine as the second catalyzer increases the amount of 
ester formed, it yet remains true, as shown by the results given, 
that raising the temperature above the point where alcohol will 
just distil from the esterification flask will decrease the amount 
of benzoic ester produced in the ease of either zine chloride or 
zine bromide, except where the zine bromide is present in 
amount almost equal to the weight of benzoic acid taken. 
Zine chloride in presence of hydrochloric acid is, however, a 
more efficient catalytic agent, both the hydrobromic acid and 
the zinc bromide being especially sensitive to any rise in tem- 
perature. 

The amount of ethyl benzoate produced in experiments (1) 
and (3) of Table III is in the opposite ratio to the quantity of 
the ethyl chloride formed. Hence, the statement found in the 


288 Phelps and Kddy—Hydrobromic Acid. 


literature that the efficiency of hydrochloric acid as a catalyzer is 
dependent upon the formation of nascent ethyl chloride would 
not seem to be borne out by these experiments. 

It is to be noted, on the other hand, that zine chloride, 
known to be one of the best catalyzers* in the formation of 
ethyl chloride from alcohol and hydrochloric acid, helps the 
esterification of benzoic acid. The extent to which hydro- 
chloric acid has reacted to form ethyl chloride, either with or 
without zine chloride, is seen on comparing (1) and (8) of 
Table ILI. The acid found in the esterification flasks in (1) 
and (2) of Table III shows a tendency to the accumulation of 
mineral acid in that, flask. This accumulation is greater, 
naturally, at the lower temperatures. A similar tendency 
was observed at the temperature of 85°—90° in experiment (1) 
of Table I with hydrobromic acid. Since in (1) and (2) of 
Table III the same amount of alcoholic hydrochloric acid was 
employed, the temperature being the only marked difference, 
the results are directly comparable. It would seem possible 
that the accumulation of hydrochloric acid at the lower tem- 
perature might explain the greater yield of ester obtained. 
That is to say, the catalytic effect of hydrochloric acid to give 
ideal yields of ester depends upon a certain concentration of 
acid or of positive hydrogen ions, other conditions remaining 
the same. It would seem from these experiments that neither 
the concentration of the hydrochloric acid nor the concentra- 
tion of the positive hydrogen ions can be the determining 
factor in esterification in the presence of zine chloride, since 
it has been shown that aleoholic hydrochloric acid gives a 
much higher yield of ester in the presence of zine chloride 
than when acting under precisely the same conditions without 
zinc chloride. The well known catalytic effect of zine chloride 
on ethyl alcohol and hydrochloric acid to form ethyl chloride 
must have taken place and thus have diminished the concen- 
tration of the hydrochloric acid. Not only this, but in this 
action of aleohol and hydrochloric acid water has been pro- 
duced, which would also be a hindrance to esterification. Yet 
the fact remains that in the presence of the lower concentra- 
tion of hydrochloric acid, even with: the water formed. by 
alcohol and hydrochloric acid in the presence of zine chloride, 
the zine chloride is a most efficient catalytic agent in esterifica- 
tion. 

Another proof that the amount of ester produced is not pro- 
portional to the concentration of the positive hydrogen ions 
present has been mentioned earlier in this paper, when it was 
noted that, under otherwise similar conditions, a small amount 
of sulphuric acid, which ionizes to a smaller extent than hydro- 


* Groves, Ann., clxxiv, 372. 


Phelps and Eddy—Hydrobromie Acid. 289 


chloric acid, which might be taken even in large amount, is 
a more efficient catalyzer in the production of ethyl benzoate. 
It has been noted in previous papers on esterification and in 
this paper also, that an increase up to a certain limit in the 
amount of catalyzer present under given conditions has been 
helpful in every case studied. The increase in the amount 
of eatalyzer beyond that limit is decidedly harmful, judging 
from the amount of ester formed. This would appear to be 
due to the fact that the catalyzers used, hydrochlorie acid, zine — 
chloride, hydrobromic acid, zinc bromide, and sulphuric acid, 
have a strong aftinity for water. It is also a fact, that each of 
the catalytic agents used reacts with alcohol of themselves to 
produce water, ethyl chloride being formed with hydrochloric 
acid, ethyl bromide with ‘hydrobromic acid, and, ethyl ether 
with sulphuric acid. Consequently when they are present in 
large amounts together with a high-boiling point ester, abso- 
Inte alcohol is not able to effect dehydration as completely as 
is necessary for complete esterification. 
_ Hence it would seem that to esterify a given organic acid 
under most advantageous conditions for complete esterification 
it is necessary to determine experimentally the proper propor- 
tions of alcohol, the time of action, the most efficient catalyzers, 
and the most suitable temper ature at which reagents and cata- 
lyzers interact. It has been shown that concentration of mineral 
acids as catalyzers does not control the esterification at the 
temperatures studied, and, further, that the best conditions of 
temperature for the formation either of ethyl chloride or of 
ethyl bromide are not ideal ones for esterification. When 
further experimental data upon this question are at hand it is 
hoped that the real function of catalyzers in esterification will 
be made known. 


290 Phelps, Palmer and Smillie—Ester Formation. 


Arr. XXXII.—Researches on the Influence of Catalytic. 
Agentsin Ester Formation. The Lffect of Certain Sulphates 
on Benzoice and Succinic Acids; by I. K. Puetps, H. E. 


Patmer, and R. Sinus. 
[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxviii.] 


In a former work* published in this Journal it has been shown 
that almost theoretical yields of succinic ethyl ester may be 
obtained by passing alcoholic vapor charged with dry hydro- 
chloric acid into the flask containing the succinic acid. Ina 
somewhat later papert in this series of researches on esters, 
under the direction of one of us, it has been shown that theoret- 
ical yields of benzoic ethyl ester may be obtained from benzoic 
acid, using sulphuric acid as a catalyzer, while 1f no catalyzer 
be present, only a trace of the ester is produced under con- 
ditions otherwise precisely similar. Bogojawlensky? has stud- 
ied the effect of various morganic sulphates on the esterification 
of a number of organic acids, using as the indication of esteri- 
fication the amount of ester produced by heating the mixture 
of acid, alcohol, and catalyzer on a return condenser. In the 
case of benzoic acid he obtained a yield of 92 per cent with a 
mixture of 80 grams of copper sulphate and 1 gram of sul- 
phuric acid, while with sulphuric acid alone he obtained a yield 
of only 65 per cent, and with copper sulphate alone no ester 
whatever was formed. 

In the work to be described the effect of various acid sul- 
phates on the esterification of succinic and benzoic acids has 
been studied. Pure succinic acid was prepared by heating on 
a return condenser succinic ester, which boiled within 0°2°, 
with an equal volume of water and a few drops of nitri¢ acid, 
and recrystallizing from water the pure succinic acid formed, 
as has been described in a previons paper§ in this Journal. 
In the case of the benzoic acid, the pure acid of commerce was 
‘used. The apparatus was the same as that illustrated and de- 
seribed in an earlier paper| in this Journal on the esterification 
of succinic acid. In all of the work absolute alcohol which 
had been made as free from water as possible by repeated dis- 
tillations over lime was used. In all cases 40°™* of the abso- 
lute aleohol were put into the second flask together with the 
benzoic or succinic acid and catalyzer, and the remainder of the 
aleohol as vapor was run into the second flask from the first dur- 
ing the intervals of time indicated in the tables, the temper- 
ature of the mixture in the second flask being kept by means 
of an acid sulphate bath at 100°-110° during the action. 

* This Journal, xxiii, 368. + This Journal, xxv, 39. 


t Berichte, xxxviii, 3344. § This Journal, xxiii, 211. 
| This Journal, xxiv, 194. 


Phelps, Palmer and Smallie—Ester Formation. 291 


The catalyzers studied were the acid sulphates of potassium, 
- ammonium, sodium, pyridine, and aniline. These were made, 
in the case of the inorganic salts, by heating the anhydrous 
neutral sulphates with the proper proportions of sulphuric acid 
in a porcelain crucible until the mass fused together, then 
grinding in an agate mortar. The organic sulphates were 
made by adding sulphuric acid in the proper proportions to 
the pyridine or aniline in the esterification flask in the case of 
the benzoic acid; in the case of the succinic acid, however, they 
were mixed before being put into the flask. The sodium sul- 
phate, the potassium sulphate, the pyridine, and the aniline 
were the pure anhydrous material of commerce. Pure ammo- 
nium sulphate was prepared by treating in water solution with 
an excess of sodium hydroxide the ammonium salt precipitated 
by the action of hydrochloric acid on cyanacetic ester under the 
conditions shown in an earlier paper* in this Journal and 
catching the ammonia evolved on distillation in dilute sul- 
phuric acid. The salt obtained by evaporating the solution, 
neutral to litmus, was recrystallized and dried. 

The proportions of catalyzers used were chosen such that the 
amount of the sulphuric acid used to form the acid sulphates 
here was the same amount, or a multiple or submultiple of the 
amount, used as catalytic agent in the former papert on the 
esterification of benzoic acid; that is to say, the concentrations 
of the hydrogen ions present during the esterification in the 
two researches were in molecular ratio. 

Of the catalyzers studied, the acid pyridine sulphate was the 
only one which seemed to go entirely into solution during the 
esterification. Of the others, the acid ammonium sulphate was 
perhaps the most soluble, but it did not go entirely into solu- 
tion, even in the case of the smallest amount which was used. 

The succinic ester in experiments (1) to (7) inclusive of Table 
I was recovered, according to previous work,t{ by treating the 
crude ester in the esterification flask with an excess of solid 
potassium: carbonate, and heating the flask fitted up for a 
yacuum distillation with a 100° Claisen flask as receiver, 
under a pressure. of 15™™, to 100°-110° on an acid potassium 
sulphate bath until no more carbon dioxide was evolved. The 
ester was then distilled under the same pressure—15"™—, 
allowing a stream of cold water to strike the receiver continu- 
ously during the distillation. The distilled product was then 
redistilled, the lower boiling impurities being first removed by 
raising the temperature of the flask to 60° under a pressure of 
15™™", before the succinic ester was distilled and weighed. The 
succinic ester in the remaining experiments of Table I and the 


* This Journal, xxvi, 258. + This Journal, xxv, 39. 
t This Journal, xxvi, 253. 


292 Phelps, Palmer and Smillie—EKster Formation. 


benzoic ester in all of the experiments of Table II, except 
where aniline acid sulphate was the catalyzer, were recovered - 
by shaking out the ethereal solution of the impure ester from 
the esterification flask with a solution of sodium carbonate in a 
separating funnel containing a few pieces of ice and washing 
with a saturated solution of sodium chloride. The sodium ear- 
bonate and the sodium chloride wash waters were each extracted 
separately twice with fresh portions of ether to recover any 
portions of the ester that may have been carried along with 
them, and these ethereal solutions were added to the main mass 
of ester. The ether was distilled off on a water bath, after 
which the flask containing the ester was fitted for a vacuum dis- 
tiation. The lower boiling impurities were removed by rais- 
ing the temperature to 60° under a pressure of 15™™; the ester 
was then distilled by heating to 140°-150° on an acid potassium 
sulphate bath under the same pressure—15™"—, the receiver 
being cooled by allowing a stream of cold water to strike it 
continuously during the distillation. In the experiments where 
aniline acid sulphate was used, since the aniline formed on 
neutralization with sodium carbonate would distil over along 
with the benzoic ester, the aniline sulphate in experiments 
(27), (80), (381), and (82) of Table IL was removed by frst 
shaking up the ethereal solution of the crude ester with water 
in a separating funnel, and the recovery was then carried out 
in the usual manner. In experiments (28) and (29) of Table II 
all the material which would distil over below 150° under 15™™ 


TABLE I, 

Suc- Abso- Reaction Succinic ester 
cinic lute time — -A~- —~ 
acid Catalyzer alcohol —-+-— Theory Found Per 
No. grm. grm. em?’ hr. min. grt. | erm ewcend 
1. 30 HSs0, 0°5 2001 25. 73% (Oia aes 
Zo 40s oe 0°5 200 <1. 30° 73°T = 7000S oce 
3. 90 Bs 0°5 A400 1° 15° °438°7 — 7245 Bere 
AS 2150 és 0°5 400 2 Or T3°T 20 eae 
5. 50 bf 1:0 200.5 450. F380 
G2 oa0 3 1:0 200 1 0. 73897 10-72 Sone 
ik iho) KHSO, 0°694 200 1 10 738°7 33°40 45°3 
8. 50 Fe 9-777 200.1 30. 72:7 56702 ee 
9, 50 ce 5°5p4. 200 = .55. 73°7 3654s 
10. | 50 (NH,)HSO, 0°587.° 200. 1. 10° 73:7. 39 arene 
Lin a0 a 2:348 200 1° 15 “732i b9:SoRee lee 
1 eAaie 9 @) rs 4°696. 200. 1 45 73°27 sGo285mmoure 
lon 50 NaHSO, 4:899 900% I 15” 737 69 2aoeae 
14. 50 C,H,N.H,SO, 0°907° 200. — 50. 73:7 > 44:35) 36052 
15,0250 ee 0'907 200 1 On 187 428s wear 
1 O13 1 ea O eae ae 


16. 50 CHINH,.H,S0, 0°975. 200 


Phelps, Palmer and Smillie—Ester Formation. 293 


pressure was collected first and afterward purified in the usual 
manner by treatment with ether. 

From an inspection of the results of Table Tit is evident 
that theoretical yields of succinic ester are obtained with sul- 
phuric acid as a catalyzer, taking into consideration the loss of 
ester inherent in the process of recovery. In the case of acid 
potassium sulphate a greater yield is obtained by an increase, 
within limits, in the amount of catalyzer. This is shown by 
comparing (7) with (8). But if the catalyzer is present in 
larger amount, there tends to be a falling off in the yield, as is 
shown by comparing (8) with (9). Acid ammonium sulphate 
accelerates the esterification much more than acid potassinm 
sulphate. An increase in the amount of acid ammonium sul- 

hate increases the yield of ester. As is shown in experiment 
(13), acid sodium sulphate under the conditions of this experi- 
ment gives almost as good results as sulphuric acid alone. 

In Table IJ are given the resuits with benzoic acid. It will 
be seen that acid potassium sulphate does not accelerate the 
esterification to any great extent, but that an increase in the 
quantity of the acid sulphate present up to a certain extent in- 
creases the yield, as appears in experiments (8) and (4); how- 
ever, the presence of a still larger amount of the acid sulphate, 
as in experiments (5), (6), (7), and (8), seems to hinder the 
esterification; the ester ification indeed seems to depend on 
conditions not yet completely understood. In the case of acid 
ammonium sulphate, it is evident that the yields increase both 
with the time of reaction and with the concentration of the 
catalyzer. From a comparison of (10), (11), and (14), in which 
the time of reaction was approximately the same, it is seen 
that the yields increase with the concentration of the catalyzer ; 
and from a comparison of (9) with (10), (11) with (12), and 
(13) with (14), in cach of which the amount of the catalyzer 
present was the same, it is evident that the yields of ester 
increase with the time of reaction. With acid sodium sul- 
phate larger yields are obtained than with corresponding quan- 
tities of acid ammonium sulphate, but similarly the yields are 
increased as the reaction time is greater, as shown by comparing 
(15) with (16), (17) with (18), and (19) with (20), and also as the 
amount of catalyzer present is greater, as shown by comparing 
(15), (17) and (19), and further (16), (18) and (20) with each 
other. It is evident that neither the pyridine nor the aniline 
acid sulphates accelerate the esterification of benzoic acid to 
any great extent. 

In comparing these results with the results which were 
obtained with sulphuric acid alone as a catalyzer in the former 
paper* in this Journal, it is evident that none of the acid sul- 


* This Journal, xxv, 39. 


294. Phelps, Palmer and Smillie—Ester Formation. 
TABLE II. 
Ben- Abso- Reaction Benzoic ester 
Zoic lute time — —~- — 
acid Catalyzer alcohol —-+-—, Theory Found Per 
No. grm. orm. 4 em? shes mini (erin. grm. cent 
Lo 0 KHSO, 388g e200 a O 61°48 2. 4°4 
2. o0 re 1388 200 2 45 61°48 9°64 Tosa 
somo on 2777 §200°°2 15) “6148 We AG 
4, 50 S 2777 200: 3 152) 61438 VO ais 
5. 950 ES 5°5654 200 1 40 61°48 11°05 18:0 
6. 50 ay 51554 200 1 45 61°48 aie 9°4 
(AP LIOY es 5°554 200 2 20 61°48 762) hoes 
8. 50 fe 5004 »200...2) 380 61:48 107027 iG 
Sho) 210) (NH,)HSO, Mel j4 200° 2 10361248 0°48 9°0 
10. 50 ee VATs 200.3, , 152 261e48 8°69 14°] 
ll. 50 oom 2°349 200 2 50 61°48 36°43 59°3 
ee WO) os 2°349 200 3750 61:°48> 4130336722 
oy a0) “ 4°696. 200°..1°55 61°48 43°83 aiies 
14. 50 oy 4°696 200 3 0 61°48 48°56 79:0 
15. 50 NaHso, 1°225° 200 <1 °°30° 61:48 —20:995 34a 
TOs SOW ie 22 de 20 Ogre, O 61°48 40°43 65°8 
lifio OO) eg 2°450 200 1 30 61°48 46°00 74°8 
18.750 eb 2450 200 3 O 61°48 58:69. 95:5 
Legh = a0) rs 4°899 200 1 15 61°48 56°44 91°8 
20. 50 tp 4°899 200 3 0 61°48 60°58 98°5 
21. 50 CHL.N.H{SO, .0:907 200 3 10) 6148 ““Saleaiiae 
22 a 0) eS 0-907 200 4 O 61°48 5°00 8°] 
23. 50 ce 1814 200 1 35 61°48 1°46 2°4 
24. 50 ef 1°814 200 2 0 61°48 Paee 7) 4°5 
25. 50 oe 3°628 200 2 20 61°48 3°86 6°3 
26. 50 oc 3°628 200 3 10 «61°48 3°63 5°9 
Qe 50 C,H,NH,.H,SO, 0975 200 1 50 61°48 1°39 2°3 
28. 90 0:'975 200 2 40 61°48 ‘56 0°9 
One) ef 1:950 200 1 15 61°48 3 0°6 
30. 50 - 1:950. 200 .3 .20. 61:48 {2:33 imaes 
31. 50 $f 3290052200 el love oles 2°60 4°2 
Sy AEG) iy 3°900 200 3 10 61°48 4 36 rl 


phates studied, when present in amounts of equal concentration 
of acid hydrogen, are as efficient in catalytic effect as sulphuric 
acid. . Acid sodium sulphate is nearly catalytically equivalent ; 
acid ammonium sulphate gives less effect ; acid potassium sul- 
phate considerably less; while acid pyridine and aniline sul- 
phates are very poor catalyzers. The acid pyridine sulphate gives 
with succinic acid, which esterifies readily, distinctly more 
effect than acid aniline sulphate, but with benzoic acid, where 
esterification is more difficult, they give about the same effects. 

Aside from the possibility of the acid sulphate in solution 
being the active catalytic agent, two explanations would seem 
obvious for the facts. First, that the catalytic effect is due in 


Phelps, Palmer and Smillic—Ester Formation. 295 


these experiments to a dissociation of the sodium and potas- 
sium acid sulphates into neutral sulphates and sulphuric acid, 
and of the nitrogen-containing sulphates into free base and 
sulphuric acid, this sulphuric acid so formed being the active 
catalytic agent. This explanation, however, fails in the case 
of the weakly basic aniline and pyridine salts. Second, since 
in most cases the salts used as catalyzers did not go into solu- 
tion, and an increase in the amount of the salt used produced 
noticeable effects, it seems possible that the salts not in solution 
are active as contact agents. All that may be done, however, 
is to record our results until future experimentation, to be 
recorded in this series of papers on catalysis, will make clear 
the correct explanation of the facts under consideration. 


296 Phelps and Hddy—Ester Formation. 


Arr. XXXIII.—fesearches on the Influence of Catulytic 
Agents in Ester Formation. The Esterification of Benzoic 
Acid with Certain Chlorides ; by I. K. and M. A. Pretps 
and E. A. Eppy. | 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—clxxxix. | 


In this Journal* in earlier work under the direction of one 
of us, the efficiency of zine chloride with hydrochloric acid as a 
catalytic agent in the formation of the ethyl esters of benzoic, 
succinic, malonic, and cyanacetic acids has been shown. The 
esterification was carried on at a temperature of 100°-110° in 
an apparatus arranged for the purpose. 

In the work given in this paper, in the specially arranged 
flasks illustrated in the work on succinic ester referred to, the 
catalytic action of certain chlorides in presence of hydrochloric 
acid in small amount in the esterification of benzoic acid with 
ethyl alcohol is brought into comparison with the similar action 
of zine chloride with hydrochloric or of hydrochlorie acid 
alone as catalytic agent. The esterification of this acid with- 
out a catalytic agent is shown to be almost none at all. 


TABLE I. 

Ben- Abs. Ale. Benzoic ester 

ZOiC with HCl Time — re 
No. acid Catalyzer ——+— —— Theory Found 

erm. grm. cm? \per ct... hr.min. grms-) 2rme apemecns 
(1). a arenes 300) 222.0538 o. "6148 o ena ae 
( 2) 50 i eiaae 200°°1°25 9 (2 2 6148 AA ees 
( 3) 50 eee 200° 1:25 -3 30 - 61:48 “OOS 8e asees 
( 4) 50 By aN 200. 1:25 4 LL 61°48 ol oes 
(.5)°50 ZnCl, 0°50 200 1°25" 2... 6148" a8 26 eams 
( 6) 50 vi 1°00 - 200. 1:25 2 2. 61:48" S286 8 sso80 
(27) 00 ES WOO BOO PAB 74 -. 61:48 59:23 soitre 
( 8) 50 2 100) * 3007 4:25:13 .-° 61°48, 6072795 Sako 
( 9) 50 i NOLO O00 eel oan _. 61°48: 60°79 49389 
(10) 50 “10°00. ‘400. 1:25 4°. 22 6148) Gia Sao 
(11) Ome Nel 07861022005 aloo ad .. €1°48. 38°14) 62:0 
(12) 50 ae 8°60 200 Nea a2 -. 61°48 42°00 68°3 
(13) 50. ICI 1°09. 900 41°25 (2 lo 6148 ae es 
(14) 50 2 OSes OOo Shai 2 2 61:48 37-235 606 
(15)'50 - InCl 0°62. 200° 1°25 ° 2 °° 20. 61:48 - 42 A eee 
(16) 50 ef 62207 200] Ae 2antreZ 226 1:48 (Se O aioli 
(17) 50 IEE C079" 200) 125.82 .. 61°48 36°00 58°6 
(18) 50 ae LS 0 200721 22 _. 61°48 32:95 -53°6 
(19). 50. Cu@l, © 1:00) 1200: 1:25) 422) 20 61-46) soo gam 87°7 
(20) 50 or 9:87" 200 1°25 °-35> 20°" 61:48) 59:62am one 

(CuCl. : BS. 

(21) 505.05 2 58 200 125 2 .. 61:48 59°05 961 


* This Journal, xxiv, 194; xxv, 39; xxvi, 143; xxvi, 264. 


Phelps and Kddy—Ester Formation. 297 


The pure benzoic acid of commerce was used in all the work 
recorded here. The aleohol was made as anhydrous as possi- 
ble by repeated distillations over caleium oxide. A known 
amount of hydrochloric acid gas, dried by passing through 
concentrated sulphuric acid, was passed into a given: weight of 
alcohol in the cold before diluting to definite concentration. 
The pure zine chloride of commerce was made anhydrous by 
heating it to the melting point while a current of dry hydro- 
chloric acid passed, then expelling the excess of hydrochloric 
acid by further heating before granulating. Potassium chlor- 
ide was made pure by fusing potassium chlorate purified by 
recrystallization from hot water. Pure ammonium chloride 
was obtained by reerystallizing the product formed on treating 
with sodium hydroxide a water solution of ammonium salt 
precipitated in the conversion of cyanacetic ester to malonic 
ester in the procedure described in a former paper® in this Jour- 
nal, and collecting in pure hydrochloric acid the ammonia gas 


. TABLE II. 
Ben- Abs. Alc. Benzoic ester 
ZOIC Catalyzer with HCl NG ee =a 
No. acid HA —~—w Theory Found 
grm. grm. em? per ct. hr. min. grm., grm. per cent 
fee) CaCl 1-00 200 1.25 °3 15-61-48 50°30 81-8 
(2) 50 et 14200 5s Oe. 61-48) 14564: 23:9 
eaeoO ee stCly 116 200 9125 22 2105. 6148. 32°63. 5371 
( 4) 50 peel 60570 Oma loin 6229 2 6148 632-3457 59:6 
[e205 Bal tos, 200 125 .2. 15 61-48 38°70 63:0 
( 6) 50 Soe 5302200) 41:25 2.3.10 61-48 43:26. 70:4 
Meese oO) 1-005 2008 1225.38.15. 61-48 41:11. 67-9 
( 8) 50 ee OS 00 leo 2 OA eae ol 7 0n 84 ul 
( 9) 50 ep OsS0 e200 nl 25s 2 he GLAS 60-65, 98:7 
ies to Cl 2346, 200 1:25 2. 15 61°48 43°65.° 71-0 
Gib). 50 oe ee tod 200) Neto 2 61-48 46°39 55 
Ch) 
(12) 50 at Ie OO ned De eG le 30:57. 497 
2 
(13) 50 PO 2005 25 0 Fe GIA 2190". 34-5 
(14) 50) to f14-60 200 #0502 61-48 40:00. 65°! 
2 
eg s0) onl, 709677200) 1-25 13. 20: 61748... 54:91 . 89:3 
(16) 50 OO OOO eon Oe 61-48) 58-86) 95-7 
(17) 50 Se CO 200m alan Be a G48 60:00 - 97-8 
GS) 50 EbCl, 2:03) 200.125 92), £10. ..61:48. 38:70 62:9 
(19) 50 “203i 200K: Ob eee 6148. 36°58 59'S 
(20) 50. SbCl, 110 200 31:95 3° 15-61-48 51:98 84-6 
(21) 50 — SALOU e200 ieee) 61748 58°80. -95°6 
(72)50 Bill 154 200 1:25 1 26-61-48 36°93 60°'1 
(23) 50 eo 00 yee ee G48 51-35 83°5 
(24) 50 1540 200-125. 2 20 61°48 59:48 96°8 


* This Journal, xxvi, 148. 
Am. Jour. Scr.—Fourts Serius, Vou. XXVI, No. 153.—Srpremper, 1908. 


298 Phelps and Hddy—Ester' Formation. 


set free. ‘The commercially pure chlorides of copper, barium, 
and strontium were made anhydrous by drying: in an air- bath 
at 100°. Hydrous aluminium* chloride was prepared by 
precipitating the commercial salt in water solution with hydro- | 
chloric acid gas and drying the product in a desiccator. Lead 
chloride was made by reerystallizing and drying in a desiccator 
the product obtained by precipitating pure lead nitrate with 
hydrochloric acid. In case of all the other chlorides, the 
preparation of which is not given, the commercially pure 
material was used. The various chlorides were used in such 
molecular ratio that the chlorine should be present in the same 
amount as in the experiments with zine chloride, which have 
been published previously. 

The procedure is the same as has been given in the earlier 
work to which reference has been made. In the experiments 
alcohol, with hydrochloric acid in the concentrations indicated 
in the tables, was driven over as vapor from a 500™* round- 
bottomed flask into the mixture of benzoic acid and alcoholic 
hydrochloric acid containmg the additional catalyzer in a 
second 500°™ round-bottomed flask carrying a modified Hem- 
pel column through which vapors passed to a condenser. The 
temperature of the second flask was kept between 100° and 
110°. 

In most cases the crude ester from the esterification was 
recovered by extraction with ether in the manner outlned in 
earlier work on catalysis in ester formation. Where on 
account of a large amount of such catalyzers as bismuth, anti- 
mony, or tin chloride, an ether extraction would be impracti- 
cable, the mass of ester with the low- boiling products was 
distilled from the esterification flask to a 100@* Claisen flask 
before neutralizing with potassium carbonate and recovering 
by the proceduret+ published by us earlier in this Journal. 

It is evident from an inspection of the results given in the 
tables that, as has been seen in all the previous work on 
esterification, the amount of ester formed, other conditions 
remaining the same, varies with the kind and amount of the 
catalyzers present, with the time of Cen, and with the quan- 
tity of alcohol. Certain of the catalyzers appeared under the 
conditions of experimentation to dissolve completely in the 
alcoholic mixture. This was observed in the use of the chlor- 
ides of zine, lithium and tin. In the cases of the chorides of 
copper, calcium and mer cury in the higher condition the smaller 
amounts only seemed to go “into solution completely. Alumin- 
jum chloride in the smaller amount used went into solution at 
first but later in the experiment was precipitated out. The 


* Gooch and Havens, this Journal, ii, 416. + This Journal, xxvi, 208. 


Phelps and Eddy—Ester Formation. 299 


bismuth and antimony chlorides with the hydrochlorie acid in 
the concentration taken did not give a clear solution in any 
case, as is also true of all the other chlorides employed as cata- 
lyzers. In interpreting the results given in the tables some 
slight account should be taken of the fact of the insolubility 
of the salts used, especially where the amount is large. This is 
obvious when it is considered that a homogenous mixture 
could not be maintained by the agitation of the liquid as caused 
by the bubbling of the alcoholic mixture through the mass in 
the esterification flask. 

The action of the catalyzers can be seen by comparing with 
each other the experiments given in Tables I and II. Evi- 
dently zine chloride present in the larger amount as a second 
catalyzer with the small per cent of hy ydrochlorie acid causes 
the esterification of benzoic acid with ethyl alcohol in largest 
amounts although copper or tin chloride present in molecular 
ratio for chlorine content are almost equally good. The pres- 
ence of more than two grams of water of crystallization with 
‘the copper chloride in experiments (21) of Table I would 
appear to have produced no noticeable reduction in the amount 
of ester produced by the anhydrous salt taken in experiment 
(20) of Table I, where the yield is only 0-9 per cent better, 
although the time of action is decidedly longer. The chlorides 
of bismuth, antimony, and mercury in the higher condition of 
oxidation seem to be about equally efficient as catalytic agents. 
They are nearly as effective in their action as either zine, 
copper, or tin chloride. Calcium chloride present in the 
smaller amount seems to be without effect, as is seen when 
experiment (3) of Table I is compared with experiment (3) of 
Table Il. In larger amount it hinders esterification to a 
marked degree. Strontium chloride in the amounts taken 
seems to hinder esterification but not to such an extent as did 
the larger amount of calcium chloride. Barium chloride seems 
to hinder esterification slightly. The chlorides of lead, mer- 
cury in the lower condition of oxidation, manganese, and potas- 
sium at least do not assist esterification if their action is not 
entirely without effect. It was noticed that from the mercur- 
ous chloride small amounts of mercury distilled into the con- 
denser, indicating decomposition of the mercurous chloride 
under the conditions of esterification. Sodium chloride appears 
to hinder esterification slightly, lithium chloride hinders more, 
ammonium chloride still more, and aluminium chloride more 
than any of the chlorides studied here except calcium when 
present in the larger amount. 

It is worthy of note that each chloride, and, moreover, dif- 
ferent amounts of the same chloride, tend to show an individual 
and characteristic effect as a catalytic agent with a small amount 


300 Phelps and Kddy—Kster Formation. 


of hydrochloric acid in the formation of ethyl benzoic ester 
from benzoic acid and ethyl alcohol. However, it seems to be 
true that certain of the chlorides may be gr ouped according: to 
their behavior as catalytic agents here. Although from the 
theoretical considerations some of the catalytic effects shown in 
this paper might have been predicted, such as the accelerating 
action of antimony and bismuth chlorides and the lack of 
action of potassium chloride, certain of the other effects could 
not, so far as we are aware, have been predicted. The action 
of cupric and mercuric chlorides in producing large amounts 
of ester or of lithium chloride in hindering esterification could 
not nave been predicted. Further, Claisen* in the study of 
catalytic effects in the formation of acetals from aldehydes 
and ketones, found that ammonium chloride was an efficient 
catalytic agent and that the alkali chlorides were without 
action. It becomes evident then that catalytic effects are not 
only specific and individual for different chlorides and for 
different amounts of this same chloride, but, also, each catalytic 
agent gives a characteristic effect, either positive, negative, or 
neutral, in each specitie kind of chemical change. 

All of the results given here were obtained under conditions 
of temperature ranging from 100 to 110°. What differences 
may be fornd at other temperatures will be determined and 
given later. It is obviously too early in the study of catalysis 
to complete our imperfect theory for such effects as are shown 
in the contribution to the study of catalysis given in this 
paper. 

* Berichte, xl, 3908. 


Relicf Map of the United States 


We have just prepared a new relief map of the United 
States, 48 x 32 inches in size, made of a special composition 
which is hard and durable, and at the same time light. The 
map is described in detail in circular No. 77, which will be 


sent on request. Price, $16.00. 


WARD’S NATURAL SCIENCE ESTABLISHMENT, 


76-104 College Ave., ROCHESTER, N. Y. 


Waro’s Natura Science EsTaBLlisHMENT 
A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 
DEPARTMENTS: 


Geology, including Phenomenal and Physiographice. 
Mineralogy, including also Rocks, Meteorites, ete. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, etc. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, ete. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Ward’s Natural Science Establishment, 
76-104 College Ave., Rochester, New York, U.S. A. 


CON TEN T's:. 


Page 
Art. XXI.—Retardation of “Alpha Rays” by Metal Foils, 
and its Variation with the Speed of the Alpha Particles; 
by. S.2hay nore tes see) feos 
XXIL.—Notes on the Lower Paleozoic Rocks of Central 
New MexicosroyAVe dT. Lem. 5 ee 180 
XXIII.—Kaersutite from Linosa and Greenland; by H. S$. 
WasHINGTON; with Optical Studies by F. EK. Wricur_.. 187 
XXIV.—Geology of the Isthmus of Panama; by E. Howe 212 


SCIENTIFIC INTELLIGENCE. 


Geology—Geology of the Adirondack Magnetic Iron Ores, D. H. NEwnanp: 
Geologishe Prinzipienfragen, E. Reyer: Die Entstehung der Kontinente, 
der Vulkane und Gebirge, P. O. KOHLER, 238.—Geological Survey_of 
Canada, A. P. Low: Geography and Geology of a Portion of Southwestern 
Wyoming, A. C. Veatcu, 239.—Hinfihrung in die Paléontologie, G. STEIN- 
MANN: Niagara Stromatoporoids: Occurrence of Hobocystis in Ontario, 240. 

Miscellaneous Scientific Intelligence—Publications of the Japanese Harth- 
guake Investigation Committee, 240.—The Physical Basis of Civilization, 
T. W. Hetneman: General Physics, H. Crew, 241.—Die Insektenfamilie 
der Phasmiden, K. B. v. WATTENWYL und J. REDTENBACHER, 242, 


SUPPLEMENT. Page 


Art. XX V.—On the Esterification of Malonie Acid; by I. 

K- Paetrs and EW. TitLorson, Jn. =. So eee 243 
XXVI.—Concerning the Purification of Esters; by I. K. 

and: M. A. -Prmies and. HA. Hppy 22 22s 2 ee 253 
XX VIT.—On the Conversion of Cyanacetic Ester to Malonic 

Kster ; by IL. K. Pnrnrs and E. W. Tirvotson, Jr. --. 257 
XX VIII.—Researches on the Influence of Catalytic Agents 

in Kster Formation. On the Esterification of Cyana- 

cetic Acid ; by I. K. Pustrs and KE. W. Tittotson, Jr. 264 
X XIX.—On the Preparation of Malonic Acid or its Ester 

from Monochloracetic Acid; by I. K. Puertrs and E. 

AV = HELLEOTSION dR: 2.2 oes ee oe 22k er 
XX X.—On the Preparation of Cyanacetic ‘Acid and its Ester 

from Monochloracetic Acid; by I. K. Poenps and E. 

Ws TIELOTSON, JB oo a ee ee 275 
XX XIJI.—Researches on the Influence of Catalytic Agents in 

Ester Formation. Hydrobromic Acid and Zinc Bromide 

in the Formation of Ethyl Benzoate; by I. K. and M. 

A. Parips-and HE. A. Wppy i. Ve ee ee 281 
XX XII.—Researches on the Influence of Catalytic Agents 

in Ester Formation. The Effect of Certain Sulphates 

on Benzoic and Succinic Acids; by I. K. Puutpes, H. E. 

Patmer and, Re SMILLIE. 6. oe 290 
XX XIII.—Researches on the Influence of Catalytic Agents 

in Ester Formation. The Esterification of Benzoic Acid 

with Certain Chlorides; by I. K. and M. A. Puetps 

and i. Aa Hapa nee i a ese ee 


- 
iy 


Librarian U. S. Nat. Museum. — 


oT 
- 


VOU XX VI. OCTOBER, 1908. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE, 


Epitorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or CamsBrince, 


Proressors ADDISON E. VERRILL, HORACE L. WELLS, 
L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor GEORGE F. BARKER, or PuinapELpun, 
Proressor HENRY S. WILLIAMS, or ItwHaca, 
Proressor JOSEPH S. AMES, or Battimorz, 
Mr. J. S. DILLER, oF Wasuinerton. 


FOURTH SERIES 


VOL. XXVI—[WHOLE NUMBER, CLXXVI_] 


No. 154—OCTOBER. 1908. 


NEW HAVEN, CONNECTICUT. 


1908 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET, 


Published monthly. Six dollars per year, in advance. $6.40 Aoxountries in the 


Postal Union ; $6.25 to Canada. Remittances should be made eithér by»money orders, 
_registered letters, or bank checks (preferably on New York banks). f= 


RARE CINNABAR CRYSTALS FROM 
CHINA. 


The first consignment of these rare specimens were sold on sight. We 
have now received a second consignment of all there are, as the mine is now 
filled with water. They come from Wanshanchang (Hamlet of Ten Thou- 
sand Hills), Tungyen Prefecture, Prov. of Kweichow, China. They occur in 
ordinary and interpenetrating twins of bright ruby red color. In size the 
crystals are from + to ? inches. The matrix is a pure white quartz, the 
crystals always occurring in cavities, with quartz crystals; prices run from 
$10, $15, $20, $25, $385, $50, $75, $100, $125 and $150. 


NEW ARRIVALS IN RARE MINERALS AND 
NEW-FINDS. | 


Anatase, with Hisenrose, Binnenthal; Altaite, N. Mex.; Atacamite, S. 
Aus. ; Albite with brookite and oetahedrite, Canton Wallis, Switz. ; Angle- 
site, Monte Poni; Argentine, San Miguel Co., Colo., and Freiberg, Saxony : 
Axinite, France; Apatite, Saxony; Benitoite, San Benito Co.,, Cal. ; 
Beryls, pink, Mesa Grande; Bindheimite, S. Dakota; Breithauptite, Andre- 
asberg: Bismuth, native, Cobalt, Ont. ; Cronstedtite, Pribram; Cassiter- 
ite, large crystals, Morbillan, France; Californite, new find, Tulare Co., 
Cal. ; Cabrerite, Laurium, Greece; Cerussite, Broken Hill; Crocoite, 
Berezow, and Tasmania ; Calcite enclos. copper, Calumet, Mich. ; Dycrasite, 
Germany; Domeykite, Coquimbo; Diopside with essonite, Piedmont; 
Diamonds in matrix, New Vaal River mine and Old Kimberley Mine ; Epi- 
dote, Prince of Wales and Alaska; Embolite, Broken Hill; Emerald in 
pyrite, Bogota, S. A.;. Gold, Transylvania, octahedron xls in quartz ; leaves 
in matrix from Verespatak, also from Siebenbergen, etc.; Herderite, 
Auburn, Me. ; Ilvaite, Elba; Jordanite in dolomite, Binnenthal ; Josephine- 
ite, Oregon; Libethenite, Hung.; Nagyagite, Nagyag; Neptunite, San 
Benito Co., Cal.; Niccolite xls., Saxony and Germany ; Opal, Barcoo River ; 
Pyrosmalite, Sweden; Parisite, Montana; Pseudobrookite, Hung.; Pent- 
landite, Ontario; Pyromorphite, Nassau, Germany; Pericline, Binnenthal ; 
Polianite, with pyrolusite, Brazil; Phenacite, Norway; Pyrargyrite xls., 
Hartz; Polybasite, Hung. ; Ruby in matrix, Burma; Ruby spinel in matrix, 
Burma; Strontianite, Hamm, Germany ; Sphene, Binnenthal ; Smithsonite, 
Kelley, N. Mex.; Sartorite, Binn.; Titanite on adularia, St. Gothard, 
Schwarzenstein and Tilly Foster ; Torbernite, Cornwall; Tetrahedrite, 
Cobalt, Ontario and Bingham, Utah; Tourmaline, pink and green, in 
feldspar with quartz; Uranothallite with uraninite, Bohemia; Uranite, 
Bohemia; Vanadinite, Kelley, N. Mex.: Vivianite xls., Leadville, Colo. ; 
Vesuvianite, Italy; Witherite, Northumberland; Wulfenite, Organ Mts., 
N. Mex. ; Zaratite, Lancaster Co., Pa. 


REMARKABLE CUT GEMS. 


Green garnets, aquamarines, zircons, sapphires, star sapphires, star rubies, 
chrysoberyl cats-eyes, opals, topaz, spinel, pink beryls, sphene, tourmaline, 
amethyst, andaluzite, star quartz, peridote, reconstructed sapphires and 
rubies, and other precious and semi-precious stones. 

Write to-day for our 10-page Bulletin. 


A.H, PETEREM, 
81—83 Fulton Street, New York City. 


AU sto; 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES. ] 


Art. XXXIV.—Buried Channels Beneath the Hudson and 
ats Tributaries ; by J. F. Kemp. 


Tur Hudson river has afforded to previous observers prob- 
lems of more than ordinary physiographic interest. The dis- 
sected peneplain, which the Highlands about West Point 
present to those who look abroad from any of the neighboring 
summits, is one of the best exhibitions of this land-form, easily 
accessible to routes of travel. Although the Highlands appear 
from the surface of the river to be a range of mountains, from 
the summits themselves the group becomes an incised plateau 
forming part of the Schooley peneplain, first identified in New 
Jersey ‘to the southwest by W. M. Davis and J. W. Wood, Jr.* 
This peneplain probably marked the closing of a eycle of 
drainage fairly coincident with the Cretaceous period. An 
‘uplift subsequently revived the streams and the Tertiary cycle 
began. The traces of the latter are still visible along the Hud- 
son in rocky terraces, which stand out with marked conformity 
as a series of shelves, best shown in the western bank and 
especially prominent in the cold season. A walk from Fish- 
kill to Peekskill on a crisp winter’s day, when the foliage no 
longer masks the relief, will serve to bring out many points 
not visible in the months of leaves. 

Having excavated the broader valley outlined by these 
shelves, the river was obviously again revived and eroded, 
within the older limits, the narrower channel of whose details 
we are just now gaining possession. They piece out in part a 
missing or fragmentary chapter in its history, the one which | 
relates to the time antedating the invasion of the continental 
glacier. As will be shown, they corroborate the previously 

* The Geographic Development of Northern New Jersey, Proc. Boston Soe. 


Nat. Hist., xxiv, 565, 1890. Also W. M. Davis, The Catskill Delta in the 
post-Glacial Hudson Estuary, idem., xxv, 318, 1892. 


Am. Jour. Sci.—FourtH Series, VoL: XX VI, No. 154.—Ocrossr, 1908. 


Pd ow 


302 J. fF. Kemp—Buried Channels Beneath 


inferred elevation of the land which we had been led to assume 
from the general phenomena of ice accumulation and from the 
specific characters of the submarine valley of the Hudson, 
whose recognition even before 1863 by the late Professor J. 
D. Dana marks one of the many acute observations and infer- 
ences regarding the local geology which we owe to his tireless 
ACUIYIt ce eikat ofessor Dana, however, had but imperfect data 
and consequently an inadequate idea of the depths involved.* 
Mr. A. Lindenkohl of the U. 8. Coast and Geodetic Survey, 
and with more extended soundings, took up the question 
anew in 1885 and 1891. A canyon was demonstrated in the 
continental shelf which about 50 miles off Sandy Hook was 
2400 ft. below the neighboring sea-bottom, there found at a 
depth of 420 ft. Beyond this point and along the course of 
the submerged channel, soundings of much less depth were 
met, and for some years ‘the inference was drawn that a bar, of 
inexplicable character and apparently too far out to be a ter- 
minal moraine, crossed the mouth of the canyon and filled it 
up. Subsequently more numerous soundings proved this 
apparent bar to be due to asharp southerly bend in the canyon, 
whose course had hitherto been southeast to east by south, and 
that it extended with increasing depth to the edge of the con- 
tinental shelf. These latter features have been especially brought 
out and emphasized by J. W. Spencer in a valuable series of 
papers discussing off-shore phenomena in the sea-bottom, and 
best summarized in this connection in the reference given 
below,t in which will also be found a review of earlier work. 
Dr. Spencer demonstrates the existence of the canyon down to 
9000 ft. below the surface. This aspect of the subject will not 
be pursued further in this paper, the object being merely to 
remind a reader that these conditions exist off the mouth of - 
the Hudson and that they have an interesting connection with 
the phenomena of its land-channel. ‘The most obvious sugges- 
tion in explanation is the elevation of the land, yet the amount 
of elevation required is a bit staggering. We are reminded of 
the alternative view, not without its advocates, that the land 
may have remained stable while the ocean drew off to the 
southern hemisphere and by lowering the sea-level established 
equivalent drainage relations.§ 

* See the Manual of Geology, Ist ed., 1865, p. 441, where the depth at 
about 80 miles from Sandy Hook is given as only 720 ft. 

+ Geology of the Sea-Bottom in the approaches to New York Bay, this 
Journal, xxix, 475, 1885. Notes on the Submarine Channel of the Hudson 
River, and other evidences of Post-Glacial Subsidence of the Middle Atlantic 
Coast Region, this Journal, xli, 489, 1891. 

{+The Submarine Great Canyon of the Hudson River, this Journal, Jan- 
uary, 1905, 1-15. 


Se Wi "Pearson contributed a series of papers upon this point to the 
supplement of the Scientific American, early in 1908. 


the Hudson and its Tributaries. 303 


Others have been impressed with the possibilities of sub- 
marine erosion by a current along the sea-bottom, and have 
sought in this way to avoid the necessity of assuming an im- 
pr obable elevation.* 

The submarine channel is first and somewhat faintly discern- 
ible about 5 miles off Sandy Hook. From this point north it 
is submerged in later sediments and is unrecognizable. From 
Princes Bay on the Staten Island shore outward the strata are 
the soft and incoherent beds of the Mesozoic and Tertiary, but 
from Princes Bay northward to Cornwall-on-Hudson the hard 
metamorphic and plutonic rocks form the bottom; still farther 
north are the scarcely less resistant slates, sandstones, and lime- 


_ stones of the Ordovician and Cambrian. In these two portions 


erosion must have proceeded more slowly. 

Turning from the pre-Glacial Hudson for the moment, the 
post-Glacial work may. be briefly reviewed in order to make 
clear the state of our knowledge from this point of view. Upon 
the iater deposits much the most detailed work has been done. 
It was early recognized that a period of subsidence had followed 
the retreat of the ice sheet, making of the valley a quiet estuary 
in which the fine Champlain clays were laid down. Upon 
these and after an uplift the very prominent gravel and sand 
deltas were built up. Subsequent elevation | brought about 
their bisection and the exposure of the clays well above tide- 
level. F. J. H. Merrill has traced these and their relations 
from New York to Albany.t+ 

The local details of terraces, deltas, moraines, ete. have been 
elaborated in still greater detail by C. E. Peett of the Depart- 
ment of Geology at the University of Chicago, and by J. B. 
Woodworth under the auspices of the N. Y. State Geological 
Survey. Both these writers treat the interesting question of 
the old relations of Lake Champlain and the Hudson, but these 
later problems do not bear very closely on fhe points here to be 
elaborated. These concern the drainage relations in that crit- 
ical stage when the Glacial epoch was approaching, and they 
give us some insight into the attitude of land and sea during 
this and later time. 

The data utilized in this paper were gathered by the Board 
of Water Supply of the City of New York and in connection 

* This alternative is briefly discussed with citations in J. B. Wcodworth’s 
Ancient Water Levels of the Champlain and Hudson Valleys, Bull. 84, N. Y. 
State Museum, 71-72, 1905. 

+ Post-Glacial History of the Hudson River Valley, this Journal, xli, 460, 
1891. Origin of the Gorge of the Hudson River, Bull. Geol. Soc. Amer., x, 
498, 1899. 

t Glacial and Post-Glacial History of the Hudson and Champlain Valleys, 
Jour. Geol., xii, 415-469, 617-660, 1904. 

$ Ancient Water Levels of the Champlain and Hudson Valleys, Bull. 84, 


_ N. Y. State Museum, 1905. 


304 J. i. Kemp—Buried Channels Beneath 


with the new sources of water which are to be tapped from 
Esopus Creek in the Catskills for the rapidly growing popula- 
tion of the metropolis. The writer would express his acknowl- 
edgments to J. Waldo Smith, C.E., Chief Engineer, for 
permission to use the data in this way, and to Robert Ridg- 
way, C.E., Department Engineer of the Northern Department, 
within whose territory nearly all the ground here covered is 
embraced. From the Division Engineers, A. A. Sproul,-W. 
E. Swift, L. E. Brink, L. White and C. E. Davis, and from 
J. F. Sanborn in charge of the geological features and records, 
every facility has been received. - Alfred D. Flinn, C.E., 
Department Engineer of Headquarters, has written of the 
Storm King crossing.* The writer has constantly worked 
with his colleague, Dr. C. P. Berkey,t in the field and has dis- 
cussed results in the laboratory. The interpretations here 
given and the details of local geology are based upon th 

observations and inferences of both. 

The General Line of the Aqueduct.—The main reservoir 
for the new supply will be developed by a huge masonry dam 
which will cross and impound Esopus Creek at the Olive 
Bridge site, a few miles below Shokan in Ulster County. 
The dam is to be in the more open country southeast of the 
Catskills, which are in full view afew miles away. At this 
point the Esopus is in a deep post-glacial gorge in the Hamil- 
tont flagstones, which dip at a flat angle to the northwest and 
are cut into extremely regular blocks by a most remarkable 
series of joints. The master joints average N. 21 E.; the next 
in prominence, N. 71 W., while rarely there are others at N. 
9W.and N. 8 E. 

The spillway of the dam will be at 580 ft., so that wher- 
ever in its course to the city the aqueduct crosses a. valley, 
the water must be conducted in a pressure tunnel. Since bed- 
rock tunnels for a clear cross-section of fifteen feet or more 
are far cheaper than steel pipes, it has been of prime import- 
ance to keep the aqueduct in solid rock, with sufficient cover 
wherever it dipped below grade; at the same time a tunnel 
whose bursting pressure is from within, rather than from 

* Explorations for Hudson River Crossing of the Catskill Aqueduct, New 
York City, Engineering News, April 2, p. 308, 1908. 

+ Early in the development of the explorations the writer was appointed 
consulting geologist to the Board. About the same time Prof. W. O. Crosby 
received a similar commission and a year. later Dr. C. P. Berkey. While 
the writer has often worked in association with Dr. Berkey, our reports have 


been made in entire independence of those of Prof. Crosby, with whose - 
results the writer is not familiar. 

{ The name Hamilton is here used in a general sense to include the Hamil- 
ton, Sherburne and Ithaca. The section embraces practically uniform sand- 
stones and shales, almost if not quite devoid of index fossils, and with no. 
sharp demarcation. It is quite certain, however, that the higher members 
are included. 


the Hudson and its Tributaries. 305 


without, presents certain novel and interesting problems and 
makes solid rock a fundamental necessity. In the locations 
the geologist is of well-nigh indispensable service to the 
engineer. 

In the course of its line from the reservoir to New York, 
the aqueduct has to cross the following principal depressions: 
Rondout Cr. 160’ A.T.; Wallkill River 150’ A.T.; Moodna 
Cr. 90’ A.T.; Hudson River 0 A.T., which it reaches at 
El. 400+; Sprout Br. 145’ A.T. and Peekskill Cr. 60’ A.T. 
Before the final line was selected several tentative ones were 
explored, giving us the records of depressed channels not on 
the final line. At the outset wash-borings alone were used, 
but when later tested by the diamond and ealyx drills they 
were found to be entirely unreliable. On the basis of their 
records a bowlder might be taken for the bed-rock as easily as 
not. The sections subsequently plotted on wash-borings, there- 
fore, show merely that the bed rock is presumably deeper yet. 
To this extent they are, however, of value. 

The geological. section inevitably crossed is complex both in 
number of formations and in their structural relations. 
Beginning on the north in the flat Hamilton beds of the 
Devonian, the tunnel in passing beneath Rondout Creek pene- 
trates the full section of the Helderberg series as shown in 
fig. 4 together with the Shawangunk grit, in and west of the 
mountains of the same name. It passes beneath Bonticou 
Crag, three or four miles north of Lake Mohonk, and thence 
through or over Hudson River slates until it reaches the 
Archean granite of Storm King mountain, here thrust up on 
the slates by a reversed fault. The tunnel dips under the 
Hudson in the granite entirely, and rises on the east bank in 
the same rock. Thence it continues over or through the sedi- 
mentary gneisses, marbles, etc., of the Grenville,* but at 
Peekskill Creek also cuts the Poughquag quartzite and Wap- 
pinger limestone of the Cambro-Ordovician. These formations 
have ail dips from flat to vertical; are folded often in a 
violent way; and are faulted in a very complicated manner. 
Several of the tentative lines had more to do with the Wap- 
pinger limestone than the one finally selected and therefore 
this formation appears along the more northerly routes. 

The General Drainage Relations —The relations of the 
tributary streams to the Hudson north of the Highlands are 
in some respects peculiar. Those on the west bank present 

* After consultation with Dr. C. P. Berkey, who has done much detailed 
mapping in the Highlands, and after going over together the exposures both 
in this locality and in the eastern Adirondacks, this name, hitherto current 


in the more northerly region, is employed, in the belief that the formations 
are essentially equivalent. 


Kemp—Buried Channels. Beneath 


7 
. 


Stee 


306 


Ge dee 


‘qutog ISOM ‘d'AA + SUL 
MLI0IG “YS + q uMo Suds “gq’g | V UMOYSUIIdG “Y's ‘ynopuoYy “y + 4ulog ssSeg ‘q'g ‘ etsdeeyxySnog ‘g ! z3[V¥g MON ‘g'N | Sanqureyy 
MON “H'N *SInqMoN “N ‘}ufog Auozg oT “aS * OAdqtoqry “I : uoyssury “yf sted ysty ‘WH $ Aopiny ‘A : SutpueT TPT 
-Ysty “Wf + LouUeysueg™ “q + esel[lA TPISIwO “O + 4ULOg Ueply “VY ‘pejse} SSUISSO1N OY} Jo SUOTZVOO] OYA MOYS 09 dew ]eIoUEy “] ‘DIA 


the Hudson and its Tributaries. 307 


an apparent reversal of drainage—that is they come in from 
the southwest and turn a sharp corner so as to flow to the sea 
in a southerly direction. The lower Esopus, the Rondout, the 
Wallkill and the Moodna all conform to this rule, as will be 
seen from fig. 1, while on the east bank the streams enter from 
the northeast. The relations are due to the geological struc- 
ture. The strike of the rocks and the trend of the ridges are 
northeast and southwest. The Shawangunk ridge, the wonder- 
fully folded and faulted Helderberg strata and the Archean 
Highlands are particularly influential. The upper waters of 
Esopus Creek come across the flat opposing dip of the Hamil- 
ton until they strike the folded lower strata and then make 
the turn. Jn the upper waters the joints are the chief struc- 
tural influences, the stream on the whole adopting a resultant 
between the N. 21 E. and the N. 71 W. , although sometimes 
on one set, sometimes on the other. 


Tributaries on the West Bank. 


The Tongore Crossing of the Hsopus.—This is shown in 
fio. 2, which is drawn looking down stream or southeast. 
The stream at.this point flows nearly east, along the minor 
series of joints N. 71 W. It has cut a steep gorge in the 
flagstones and shales to the 320 ft. contour. On the south 
bank the bed-rock rises above the 550 ft. contour and is often 


Fie. 2 


Fic. 2. The Esopus channel. The bed-rock is the Hamilton flagstones 
and shales. 
exposed, but on the north bank drift conceals all the rock. A 
series of borings has shown the cover to vary from 60 to 250 
ft., and that a buried channel exists at 240 ft. A.T., or about 
70 ft. below the present river. Its sides have gentle slopes and 
its profile is that of a much more mature stream than the pres- 
ent Esopus, from which it is distant about 2,000 ft. to the north- 
east. Several other crossings have also been explored, but this 
one will serve to illustrate the relations in altitude. 

The Hurley Crossing of the Ksopus.—In its southeasterly 
course the Esopus breaks through the Hamilton escarpment 
and strikes a broad open valley, with all the characteristics of 
an old lake bottom, located upon some well-developed valley 


308 


3. 


Ge 


J. F. Kemp—Buried Channels Beneath 


HURLEY CROSSING N.28W, 


“YD SNdOS 


,90$ 3218” 


Lie) <2 eal ao Salenle Wap eleks as ena ea ees 
. 


47 
ort+i3b 


2.0 Ne 


eo «2 ele 


E 
SE 


Fic. 3. The Hurley Crossing of the present Esopus and of the Pliocene Kripplebush. 


of pre-glacial drainage to which fuller 
reference is subsequently made: lt 
turns a right angle in this and passes 
northeasterly. Near Hurley station 
on the New York, Ontario and West- 
ern Railway, a series of borings was 
made across the valley with the results 
shown in fig. 8, On the northwest 
side is the abrupt escarpment of the 
Hamilton with characteristic shelf 
and talus outline. For nearly a mile 
to the southeast the sandy level extends 
and the first outcrops encountered are 
those of the Onondaga (old name 
Corniferous) limestone with a very 
flat northwesterly dip. The wash- 
borings, which are probably a fair 
indication of the bed-rock, reveal a 
surface which corresponds very closely 
to the dip of the strata. Apparently 
the pre-glacial stream followed down 
the dip of the limestone against the 
basset edges of the shales and sand- 
stones, sapping them until it had 
attained a depth of 68 ft. below the 
present sea-level, and showing that 
there must have been a correspond- 
ingly greater elevation of the’ land. 
In the closing stages of the ice epoch 
some barrier must have impounded 
the water in tis valley and have 
caused the accumulation of the sands. 

There are some very interesting 
questions raised by the relations of 
the pre-glacial Esopus and pre-glacial 
Zondout. The former after its north- 
easterly bend proceeds to the Hudson 
along the general prolongation of the 
latter, which turns at Rosendale 
through a high and abrupt ridge of 
the Helderberg strata, with quite 
precipitous sides, and joins the Wall- 
kill. The combined’ streams then 
reach the Hudson through an estuary 
with steep rocky sides and appar- 
ently much freshened up by the ice- 
sheet, if, as seems unavoidable, it is of 
er eater seological age. 


the Hudson and its Tributaries. 309 


The High Falls Crossing of the Rondout Valley.—As 
shown in fig. 4, the aqueduct reaches the Rondout valley on 
the northwest side at 500 ft. grade. Beyond this point for 
over four miles it must utilize a pressure tunnel known as the 
Rondout Siphon. The borings reveal a buried channel on 
the northwestern part of the valley sunk in the bed-rock to 
80+, or 270 it. below the present surface. As this is near 
the hamlet of Kripplebush we have called it the Kripplebush 
channel. The cores prove that we have a fault, probably a 


Fic. 4. 


HIGH FALLS 


OO 


MANLIUS o- HIGH. SHA WANGUN I< GRIT HUDSON RIvER SLATE 
S.S, SHALE SHAWANCGUNK 


Fic. 4. The Rondout Crossing near High Falls. B. Becraft limestone : 
N.S. New Scotland limestone; C. Coeymans limestone; H.F. High Falls 
shale ; H.R.S. Hudson River slate. The sections are continuous. 
normal one, upon which the stream was located at the time it 
was overwhelmed. It had worked down the Onondaga lime- 
stone against the basset edges of the Hamilton just as had the 
old-time stream at the Hurley crossing, and then it had been 
arrested and obliterated by the drift. We have no further 
records of this stream, but along the line of the siphon and 
after leaving the valley of the Kripplebush there is only 
a thin cover of drift, with frequent outerops before the next 
depression is reached. Then about two miles farther east- 


310 J. F. Kemp—Buried Channels Beneath 


ward is the present Rondout Creek, now flowing on drift at 
the line. of the section. A little to the north, however, it 
swerves eastward and cascades over a ledge of Manlius lime- 
stone. About 400 ft. west of the point where the siphon 
passes below the present stream, the drill revealed an old, 
buried channel with a bottom at minus 10, or beneath some- 
what over 200 ft. of drift. The pre-Glacial stream had 
evidently followed down a dip slope of Manlius, sapping the 
edges of the Coeymans (labeled C in the figure) and New 
Scotland limestones until it also was obliterated by the drift. 
We think it had left a projecting ledge of Manlius as shown 
in the figure, because the drill passed from drift into limestone 
and then into drift again before it caught the bed-rock. The 
Manlius is the formation containing the waterlime beds, and 
its subdivision into the Rondout, Cobleskill, Rosendale and 
Manlius proper has not been attempted here. Somewhat con- - 
trary to one’s natural expectations, it (an argillaceous variety) 
is the formation containing the fissures and caves of the 
region, whereas one would be inclined to look for these rather 
in the Becraft, which is a very pure limestone. The ancient 
Rondout Creek moreover, somewhat strangely, seems to have 
followed the Manlius rather than the hard Shawangunk grit 
with its soft overlying High Falls shales, which were cut far- 
ther east. 

Of the further relations of this buried channel we have no 
records. The Hurley crossing showed a depth of minus 68, so © 
that so far as gradient is concerned it might have gone out 
this way. 

A mile and a quarter eastward there is a patch of drift in a 
little synclinal valley of High Falls shale, whose bottom stands 
at 160 plus, but the depression is of no great consequence. 

The Wallkill Crossings. —After passing through the Sha- 
wangunk ridge by a tunnel at grade, the aqueduct turns south- 
west ; along the surface and crosses the Wallkill valley near the 
little hamlet of Libertyville, three miles southwest of New 
Paltz. The entire tunnel will be in Hudson River slates. 
Before this line was selected, however, two lines of borings 
were made near Springtown about three miles north of New 
Paltz and several additional ones in or near the town, which 
are not here used, as they introduce no essential change in the 
conclusions. The two Springtown lines are rather less than a 
mile apart and are called, on fig. 5, Springtown A and Spring- 
town B. In the former a Wied Giawnel was found at minus 
79 almost beneath the present river, which stands at plus 150 
or about 229 feet above. The old channel is filled with drift. 
About a half mile westward a small depression was detected at 
plus 50, evidently marking a tributary and smaller stream, 
separated by a divide of less than 40 ft. 


the Hudson and its Tributaries. oe 


The Springtown B profile found the old channel of the 
Wallkill about a thousand feet east of the present one and just 
at sea-level. The old valley is broad and open with a fairly 
mature aspect. ‘The western channel is also shown but at 4000. 
ft. distance and at plus 65, or 15 ft. above the more northerly 
section. A divide of 150 ft. separated it from the Wallkill, and 
we cannot but infer that it was coming down to the larger 
stream from a source to the southwest. 

It is a striking fact that the Pliocene Wallkill dropped 79 ft. 
in the mile or less from Line A to Line B and that its valley 
narrowed appreciably. it may have been on softer slates in the 
southern section and, encountering the reefs of sandstone char- 
acteristic of the Hudson River series, cascaded over them to 
lower reaches on the north. Springtown A is the last record 


LIBERTYVILLE 


Fie. 5. Crossings of the Wallkill river near Springtown and Libertyville. 


which we have of it. The present Wallkill after combining 
with Rondout creek forms the Rondout river and enters the 
Hudson in the deep estuarine gorge at the city of Rondont, 
which has been previously mentioned. The rock bottom of 
this estuary must lie at a goodly depth below minus 79. 

The Libertyville section is six or eight miles southwest of the 
Springtown crossings. It found the Pliocene channel some 
600 ft. east of the present Walikill and 120 ft. below it, or at 
plus 65. Therefore in the intervening stretch, while the mod- 
ern Wallkill in its meandering course over the drift-filled valley 
drops 25 ft. the ancient river descended 65 ft. and thus had a 
fairly steep gradient. It must have been feeling the effects of 
uplift, although the profiles do not indicate any notable incision. 
In this section the westerly tributary is not pronounced. Its 


Fia.. 6, 


2 


,000T% JO 
AVAYBINI 


J. Lf. Kemp—Buried Channels Beneath 


The Moodna Se 


Fite. 6. 


source must either have been passed or 
else it still lies beneath the drift farther 
west than it was necessary to bore. 

The Moodna  Crossing.—-Having 
passed the Wallkill valley by a siphon, 
the aqueduct reaches sutliciently elevated 
ground to make a long course to the 
south at grade. Its first depression is at 
Moodna creek, which enters the Hudson 
just north of Cornwall. The Moodna 
proper comes in from the west, but it 
receives an important tributary, Wood- 
bury creek, which drains the valley De- 
tween Schunemunk mountain and the 
Highlands. In the three miles before it 
discharges into the Hudson the Moodna 
has cut a deep al in exceedingly 
heavy drift, with huge bowlders of very 
impressive size and extremely trouble- 
some to penetrate with either the calyx 
or the diamond drills. 

The details of the Moodna crossing 
are shown in fig. 6. The present creek 
is in the drift but very near the southern 
emergence of slates, and at about the 
100 ft. contour. For a half mile to the 
west the drills have shown a very even 
floor with a maximum depression at 
minus 59°2 beneath 360 ft. of drift. A 
divide then rises of sharp outline, beyond 
which is another old channel reaching 
minus 10. The surprising thing about 
this section lies in the fact that two or 


three miles away is the gorge of the 


Hudson with a depth below of minus 
600 ft. We have therefore been slow 
to admit that there is not somewhere in 
this section an incised notch through 


which the ancient drainage of the country 


to the southwest must have been poured 
without leaving a hanging valley 550 it. 
above its master depression. Still, care- 
ful search and fairly close-set holes have 
failed to locate it. Somewhat the same 
relationships with the Hudson gorge are 


shown by other tributaries, such as the 


Wappinger, and Fishkill a and the Or oton, 
as will be later brought out. 


- ye ae 


the Hudson and its Tributaries. . 313 


Rather more than half a mile southeast of the present Moodna, 
the siphon will cross the impressive reversed fault which has 
brought the Archean granite to rest upon the Hudson slate, as 
is clearly exposed at one siguificant locality. A small drift- 
filled channel has been met in the granite, but it is only worthy 
of passing remark. Thence to the Storm King crossing the 
aqueduct is located at grade. 


1Diceey a 


Fie. 7. The Casper Creek Crossing. 


Tributaries on the Kast Bank. 


Casper Creck.—The most northerly of the eastern tribu- 
taries is Casper Creek, which enters the Hudson six miles 
below Poughkeepsie. It was encountered by the proposed 
Pegegs Point route and tested with wash-borings, but as only 
peat, sand, and at the bottom some gravel, were encountered 
the results are fairly reliable. They are plotted in fig. 7. 
The lowest point was minus 67. The section passed from 
Wappinger limestone on the north to Hudson River slate on 
the south. The section is perhaps half a mile from the 
Hudson. 


Bie. &:. 


Fic. 8. .The Wappinger Creek Crossing. 


Wappinger Creek.—This good-sized. stream enters the 
Hudson just south of New Hamburg. Two miles back it 
yields a fine water power by a series of cascades over Hudson 
River slates, with a fall of 60 or 70 ft. The water power 
supports the village of Wappinger Falls. Thence to the river 
it forms an estuary at tide level. At New Hamburg it hes 
along the contact of the slates and limestone, but while the 
limestone appears with steep dips in the north bank, the drill 
has shown slate beneath the water. There may be a faulted 
contact; the relations are obscure. As shown in fig. 8, one 


314 aS. LF. Kemp—Buried Channels Beneath 


wash-boring reached 50 feet below tide, and of the three core 
borings, the deepest was minus 39. These comparatively 
shallow depths, taken very near the Hudson itself, are inter- 
esting parallels with the Moodna and Casper crossings, and are 
indicative of hanging valleys of somewhat striking altitude, 
and with appar ently abr upt drops to the gorge of the Hudson. 

Fishkill Creek.—Fishkill Oreek enters the Hudson just — 
south of Fishkill Landing, an important town on the river 
immediately opposite Newburg. Within two miles of its 
mouth it cascades over the Hudson River slates and is obyi- 


ously off the line of its Plocene channel. A proposed line ~ 


for the aqueduct, but one which was afterwards abandoned, 
crossed it just east of Fishkill village, a small settlement five 
miles back from the river and not to be confounded with Fish- 
kill Landing. The line crossed the creek in a direction a little 
east of south and at a flat area of meadow land where the 
stream was split into three parts. The profile is given in 
fig. 9. The entire section is drift-covered, but the two core- 
holes revealed the Wappinger limestone, as had been antici- 


idivel, 3) 


S FNS RU ere ee 


Fie. 9. The Fishkill Brook Crossing. 


pated. The deepest channel was found at —40, but strangely 
enough the drill after penetrating about 8 ft. of limestone 
met fine yellow sand, in which it continued for over 60 ft. 
until the hole was abandoned. This was interpreted as a 
crevice in the limestone filled with decomposition products. 
The conventional signs in fig. 9 are not intended to indicate 
the dip of the limestone, but merely its presence. The dip is 
unknown to the writer. A short distance to the southeast the 
limestone gives place to the Archean, but directly south it 
extends as a faulted block much farther into the Highlands. 

The. Fishkill crossing is much farther back from the Hudson 
than the Wappinger, but its depth is only 10 ft. less. 

Sprout Brook.—In its passage of the Highlands the aque- 
duct does not encounter any badly depressed area. Foundry 
brook, east of Cold Spring, has occasioned some drilling but 
has revealed no important physiographic data. Spring Brook is 
on the southern side and, with Peekskill brook, flows into 


: 


bar re 


the Lludson and its Tributaries. 315 


Annsville cove just north of Peekskill. Along this line is the 
crucial area in tle interpretation of the geology of the High- 
lands, as has already been discussed by C. P. Berkey.* 

The crossing is about three miles from the Hudson, in a 
narrow and rather steep-sided valley. Archean gneiss forms 
the hills, but after a concealed strip on each side the drill 


Fic. 10. 


SPROUT BROOK 


GON Cin CR ts Cpl i Ie 


Vv 
Vv 
NW, 
Vv 
v 
v 
Vv 
Vv 
Vv 
v 
Vv 
Vv 
v 
v 
Vv 
Vv 
Vv 
v 


Fic. 10. The Sprout Brook Crossing. Sedimentary gneiss on the west ; 
marble in the valley ; granite gneiss on the east. 


revealed white marble in the bottom, beneath 125 ft. and less 
of drift. The bottom of the buried channel was caught at —8, 
as shown in fig. 10. This is less than the last two, but the 
stream is hardly as large. The stream evidently selected the 
easily eroded limestone in preference to the harder gneisses. 


Kiera, 


ore Ce 
ant fen - 


< 


Ol-- <---- 


=< Onn yO ae er 
FE Ot Cra ess oF 


“Gone. 2 
Ses} 


PEPE TTH pee Fre 


Fic. 11. The Peekskill Brook Crossing. 


Peekskill Creek.— Kast of a steep divide from Sprout Brook 
lies the valley of Peekskill Creek, a somewhat larger stream 
and one in a broader valley. On the north side is the Hudson 
River slate at a steep angle and in an abrupt hillside. The 
present creek flows upon drift at its foot. Thence to the south 
for over a mile there are no exposures and the geology must 


* Structural and Stratigraphic Features of the Basal Gneisses of the High- 
lands, Bulletin 107, N. Y. State Museum, 361, 1907. 


316 Jif. Kemp—Buried Channels Beneath 


be interpreted by the drill-records, of which there are a satis- 
factory number. Figure 11 illustrates the section interpreted 
in the most reasonable way in order to account for the great 
thickness of limestone, whose unrepeated thickness is known 
to be about 1,000 feet. Utilizing folds only, it requires a com- 
pressed sigmoid fold of limestone from whose anticline the 
quartzite has been pinched out and from whose syneline the 
slate. As against this a series of normal faults with southerly 
dip might be imagined but are less likely since the prevailing 
fault of this region is of the reversed type. 

The lowest channel is almost beneath the present stream and 
stands at +10, somewhat unexpectedly high. 

The Croton River.—From the Peekskill crossing the aque- 
duct bears away to the east and encounters so much high 
ground as to reveal little of moment from the depressions. 
But the earlier work in connection with the great dam across 
the Croton River gives us abundant data regarding this stream. 
Mica schist appears on the northwest bank and extends about 
half way across the valley. It is then succeeded by white 
marble to the south. The former would be interpreted by F. 
J. H. Merrill* as metamorphosed Hudson River slate; the 
latter as the recrystallized Wappinger. A possibly different 
view has been conservatively suggested by C. P. Berkey.t+ 


SUMMARY OF TRIBUTARIES. 


WEST BANK. 


Distance from Hudson 


Name. in miles. Contour. 

So pus 2.5 ie Seep: 25-30 + 240° 
Hsopus (Hurley) __..-- 13-18 — 68 
IGipplebush. 22.22 224- 12-27 + 80 
eOmClOwnG Ses fe sah eee 12 — 10 
N allie spr. Ale. 2 12 — 79 
RS Age 6 alg ra 13 0 
i alle cece ant Vy +. 65 
Mic ocitapee as Ue ssi 2 — 59 

KAST BANK. 

Casper meee tion Woe 1/2 — 67 
Wappingers. 8.) oo! 1/2 a 
UTA SONG a oo 2 a 6 — 40 
Tey OP ROUGE pagae 0: aie eon 3 = 
Peek einem 84S Le 3 + 10 
Croton! yes ee 2 — 20 


* F. J. H. Merrill, The Geology of the Crystalline Rocks of Southeastern 
New York, 50th Ann. Rep. N. Y. State Museum; I. App. A. 21-81, 1898. 

+C. P. Berkey, Structural and Stratigraphic Features of the Basal 
Gneisses of the Highlands, Bull. 107, N. Y. State Museum, 861, 1907. 


the Hudson and its Tributaries. ad 


The buried channel was found at —20, while the present 
Croton flowed at +50, leaving 70 ft. of drift, mostly of bowl- 
der clay, between. The section is two miles from the Hudson. 

Summary.—F rom this tabulation it is evident that consider- 
ing the distances of the crossings from the Hudson, the Esopus 
at Hurley (or perhaps the Pliocene Kripplebush), and the Wall- 
kill at Springtown A, have eut deepest. The bed-rock at their 
mouths must be relatively far down. For those near the river 
Casper Creek is strikingly low for a stream that is decidedly 
smaller to-day than the modern Wappinger. Fishkill Creek 
with —40 at six miles back may well be much deeper at its 
Pliocene mouth, but its location has not been established, much 
less explored. Even giving all possible latitude to these depths, 
it still remains true, that as compared with the gorge of the 
Hudson, now demonstrated at the Storm King crossing, all 
these tributaries entered in the last stages of erosion, either just 
preceding or during the Glacial epoch, by hanging valleys of 
500 ft. or more above the bottom of the main stream. 


The Hudson Crossings. 


The borings which cross this great river furnish naturally 
the most interesting data of all, and, as will appear, they show 
a surprising depth to bed-rock. The crossings begin about 
eight miles north of Newburg or seven miles south of the 


_ Poughkeepsie bridge. They are somewhat irregularly distrib- 


uted, but extend at the extreme limit, about two miles south of 
West Point. The one of greatest interest is the Storm King cross- 
ing, between Storm King mountain on the west and Break- 
neck mountain on the east. Of this we have the completest 
data, but there are core-borings available at Peggs Point, next 
to the most northerly crossing, and at Little Stony Point, 
although they are not numerous. All the rest are based on 
wash-borings, which, as already stated, are only of value in. 
showing that the bed-rock is lower yet. In some of the 
wash-borings an artesian flow of fresh water was encountered 
which spurted above the decks of the lighters carrying the 
drills, deluging the drillers with water and sand. There is 
thus a connection with the hills on the banks and beneath the 
silt. A few little shells have been yielded from beds forty feet 
below the bottom of the river. 

The Tuff Crossing.—This is situated a half-mile above Peggs 
Point, where the next crossing south was located, and runs 
diagonally across the river in a direction about N. 63 W. Its 
profile is shown in fig. 12. Hudson River slates are on the 
west bank, and the heavily bedded Wappinger limestone of the 
Clinton Point quarries on the east. The geological relations are 
presumably like those at Peggs Point, of which we have much 


Am, Jour. Sct.—FourtH Series, Vou. XXVI, No. 154.—Octoser, 1908. 
23 


318 J. ff. Kemp—Buried Channels Beneath 


fuller data. The wash-borings returned a fairly even profile 
for the supposed bed-rock, at depths varying from 210 to 236 
below tide. Upon them, however, we can place no reliance. 
The Peggs Point Crossing. —This is situated a half-mile 
south of the last named and strikes directly across the river at one 
of the narrowest possible passages. A steep hillside of Hudson 
River slate forms the west bank, while a short distance back 
from the east bank are the Clinton Point quarries in the Wap- 
pinger limestone. Several lines of wash-borings were run 
across, giving distances to supposed bed-rock ranging from 139°5 
to 256 in what might be esteemed the depths of the river. The 
records were sufficiently discordant to induce the sinking ‘of 
three diamond drill cores in the river and one on each bank, as 
shown in fig. 18. The deepest one caught the slate at 223 ft., 
a record not very different from some of the wash borings. 
The next easterly one revealed the limestone at only 92 tt. 
There is an unexplored stretch of 1,040 ft. between, which 
presumably contains a deep and rather narrow gorge in order 
to fall in with the records of the Storm King crossing, roughly 
ten miles south. Otherwise the great depth at Storm King is 
very difficult to understand unless we assign to the river a fall 
of over 375 ft. in ten miles, certainly a most unusual gradient. 
The borings on Casper Creek, which enters the Hudson just 
below this crossing, showed the bed-rock at — 69, as has been 
already stated. ; 
The New Hamburg Crossing.—Two miles south of Peggs 
Point the river narrows again between the point on which is 
situated New germans on the east bank and Cedareliff on the 
west. Only 2,300 feet intervene from shore to shore, but both 
banks have the Wappinger limestone. On account of an over- 
thrust fault, which is beautifully shown near the north portal 
of the New Hamburg tunnel of the New York Central R.R. 
and is again revealed by the drill, we know that the slates le be- 
neath itas shown diagrammatically in fig.14. Only wash-borings 
were made in the river bottom, but of these five different but 
closely adjacent lines were run, of which one typical case has 
been selected for the figure. W here taken beneath the portions 
of the river well out from the banks, the extremes were 130 
and 263°5 with a general range from 195 to 255. Yet such wide 
differences were met as to destroy all confidence in the borings 
as indicative of the actual bed-rock. As against the maximum 
of 263°5 we may contrast the bed-rock in Wappinger Creek at 
50 and less. Even this would indicate a hanging valley of 
over 200 feet, above the bottom of the Hudson. 
Danskammer Crossing.—A mile south of New Hamburg, 
on the west bank, is a point with a lighthouse known as Dans- 
kammer, apparently from its having been a center of merry 


CROSSIUN G, 


TUFF 


re 5 102) 


©) 
J 
x 
° 
1°) 
+ 
4 
2! 


the Hudson and its Tributaries. 
Hie: £3: 


Ut 
c 


oF me B 
4 
aa 
‘uy 
b 3 
Sth :< G 
2 fe) ans. 
ae iw x 
:0 >) 
os ‘0 a 
a Tae 3 
= = 
@ 5 : 
y a = 
) 3 
uw : S 
pace gatas area w 
a. ; Zz 


a" 


7 


No 
~ 


00° 


x 


- eh 
3 ANY 


\ 


319 


\ 


QS 


Fie. 12. The Tuff Crossing. Fie. 18. The Peggs Point Crossing. Fie. 14. The New Hamburg Crossing. 


320 hee eee Channels Beneath 


making in earlier years among the German-speaking inhabitants. 

The distance from bank to bank is 3,500 ft., and two lines of 
wash-borings were made. In the portions beyond the influence 
of the banks the depths range from a minimum of 133°2 to a 
maximum of 268°5, with a general range from 200 to 250.. 
Again such wide variations were found and such irregularities 
as to only justify the inference of a bed of bowlders of irreg- 
ular upper surface. The crossing passed from Wappinger 

limestone on the west bank to Hudson River slates on the east. 

The details are given im fig. 15. 

The Storm King Orossing.—Some six miles south af Dans- 
kammer the abrupt ridge of the Highlands crosses the river, 
and Paleozoic strata give way to Archean granite. The 
river widens in Newburg bay, so that no more lines of borings 
were considered. Between the great granite buttresses of 
Storm King mountain on the west and Breakneck on the east 
it narrows to 2,800 ft., and at this point it was finally decided 
to locate the siphon for a number of important reasons, based 
upon the western approach and the local geology. Detailed 
exploration with the diamond drill was at once begun, but 
proved an exceedingly difficult matter to prosecute because of 
the bowlders which were encountered at two horizons. One is 
about two hundred feet from the surface and is thin; the other 
is roughly four hundred feet down and is thick and trouble- 
some. The details are shown in fig. 16, in which the relations 
of a line of wash-borings to the actual bed-rock are brought 
out in an interesting manner. Besides the diamond drill-holes 
a shaft is being sunk on each bank for later use, as a part of 
the siphon, and for horizontal diamond drill-holes when suffi- 
cient depth is attained, to test the existence of fault-zones which 
vertical holes could not locate. 

Hole 16 at 300 ft. from the east bank is certainly in the bed- 
rock at about 200 ft. Hole 19 at 560 ft. out probably stopped 
near it, but the tools met an almost impenetrable series of 
bowlders of large size and the hole was stopped. Hole 10 is 
not. on the exact line of the others, but is 300 ft. nearly due 
south from No. 22. It is the most significant of all. It 
caught the rock at 608°6 ft., penetrated it for 8°8 ft. , bringing 
up a core of granite identical with that on the banks. When 
this had been attained after months of difficult work, the trag- 
edy of the crossing occurred. A river steamer, having passed 
the hole, suddenly became unmanageable from an accident, 
drifted down on the drill and caused the loss of the one hole 
which has as yet reached the bed-rock and, as we believe, pene- 
trated it rather than a bowlder. It would indicate, therefore, 
the bottom at a depth of 608°8 feet. 


GI 
CO 


the Hudson and its T; ributaries. 


ieee lo. 


Wigs 17s 


Fie. 16. 


Fig. 1o. 


See ere rae roe gar Se IC ICR MESS ese ee ae : ESSSSNSSSSS 
y sss | a 
\ 


“OUISSOLD JUIOg Ueptly oT, ‘ST ‘S17 
‘Zurssorg yuIog LU04g OTT] OUL “LE PIA “SUISssoH SULY UII0}g oY, “OT “OIA “SuIssorp rommIBysuBg oy, “CT “Ol 


en-— TS ONTAOE-HSYM Pr) 


>= 


WN ~~ 
peal ; ; i ae SS 
Drs ! : ae 
eee ‘i ' ' ! 1 | tease 
Wy fy pYypyyyy Wi, : Q ives 1, - g ’ 
VHT, Yi Wi) Wy i : { i { H 1 tet ~~ if), ousssiana i] 
/, 4 YO, . 
Why WM Mo pyyppylyyfZ ai GY OL i) » 
“Wy fy YUU UYU YY Li 8 
Yi yl LULL if I ilile 0017 iy 
0 4 MN LLL ‘LNIOG N3AGQUY NNO yy 2 
; Lalas) OGL, 
Lip LY Y Yip, 
Mili), “LY, YL fy fy VHA AAHAAHA 
ay (etek NIA 


NAA SLINYVUD A AAA 
NIA WHOLS PArndrda® 


initod 


RAK ADLIO 


WAVYD 


. / sic} a . C) : f aS Pe 52. Tov Dente SONISOSHSVM 40 3NITV #88 2s eeee 
OLS \ A OIms : 1 eO- yea d z Weoion’ 
ONys Bees 2fisaoo \oro:s: Meee KS. S|: PF. aba 5 ) ; OF... : 


(Ons peers as aor iet aaaae wal ae ‘ : re Ee ALINVUS 
kanye . : ~ ; B 5 


ONIN WYHOLS 


‘NLW RI 
WOINAVSYD AAANANAA 
NA OA AA A 


3 * | ,Q0LE > 


f YIWWvVYASNYG 


322 J. FF. Kemp—Buried Channels Beneath 


Hole 20 at 580 ft. failed to get through the bowlders, so that 
we only know that the bed-rock is still deeper. Hole 21, about 
700 feet from the west bank, stopped in the bowlders at 475°3, 
so that we only know here that the bed-rock is deeper. It will 
be driven farther. Hole 18 at approximately 500 ft. from the 
bank was probably very near the bed-rock if not on it. The 
casing became bent and the hole was lost. The drillers believed 
that the bed-rock had been encountered at a shelving point so 
that the casing glanced off. This is not improbable, although 
a shelving bowlder is also a possibility. | 

If we believe that the great ice sheet found a V-shaped river 
valley in the Highlands and operated to change its section to 
the characteristic U-shape, then the bottom ought to flatten 
rapidly beyond hole 10, even if it had not already done so at 
this point. It is anticipated that future holes which are now 
being driven will find the bed-rock at depths not very much 
greater. 

We are justified in inferring that on the retreat of the ice 
this gorge was left with some 200 ft. of bowlders and sand on 
its bottom. Upon this foundation subsequent water deposited 
about 200 ft. of sand, gravel, and sandy clay. Either a slight 
readvance of the ice sheet or floating ice then yielded the upper, 
thin bowlder bed, after which only fluviatile conditions pre- 
vailed. If we donot credit the great glacier with much eroding 
power, then the continent must have been elevated decidedly 
over 600 ft. in order to provide a run-off. But if we believe 
that the ice-sheet operated to deepen this channel, then this 
amount of elevation is not absolutely necessary. The heavy, 
bottom bowlder-bed indicates that after the retreat of the ice 
fluviatile scour has not affected the bed-rock. 

The Little Stony Point Crossing.—About a mile south of 
Storm King a point juts out from the east bank called Little 
Stony. The river narrows to 2,360 ft., and a line of wash- 
borings was made with the results shown in fig. 17. No one 
of them reached 200 ft. Three diamond drill-holes were also 
sunk, of which the deepest, near the middle of the river, 
reached 322°2 ft. They all stopped in bowlders, so that to 
this extent the deep gorge is corroborated. 

The Arden Point Crossing.—Three or four miles south of 
the Little Stony crossing and about a mile below West Point 
is the Arden Point line, to which some exploration has been 
directed. The shores are in the sedimentary metamorphies 
of the Highlands, and on fig. 18 are called Grenville, using the 
name current in the Adirondacks and Canada. The river is 
only 2,120 ft. wide, so that the shortest section beneath its 
water of all those tested is afforded. Wash-borings, the only 
ones used, reached depths of 220 ft. and less. The line, how- 


the Hudson and tts Tributaries. 323 


ever, was abandoned for other reasons before any core-borings 
seemed called for. 

Concluding Remarks.—The great depth to bed-rock at the 
Storm King crossing leads to some interesting lines of reflection. 
We have no reason to think that the river has ever done 
otherwise than flow down-grade to the sea along its present 
channel. Some suggestions have been made of its diversion to 
the Hackensack valley, but in this the writer and his colleague, 
Dr. Berkey, who is very familiar with the local geology, have 
no confidence whatever. For this region we believe in a rather 
abrupt elevation of the land in the closing Tertiary which 
brought about a deepening of stream channels to a point as 
much below the present as the depths of the exploring holes, 
above cited, indicate. The Hudson, however, obviously cut 
much more rapidly than its tributaries, and with this the 
temporary diversion of the drainage of the Great Lakes through 
the Mohawk may have had some influence. The _ ice-sheet 
served to still further accentuate the difference, and, as often 
appears along a trunk glacier, left the tributaries as hanging 
valleys. The drill-holes at Peggs Point prove that at this cross- 
ing the gorge must be relatively narrow, but since there seems 
no way of explaining the depths at Storm King by a gigantic 
pothole or exceptionally deep, local scour, or any other reason- 
able method other than water or ice erosion, the still undis- 
-covered gorge is inferred in the 1,040 ft. between the holes. 
Since the Storm King granite is the hardest and most resistant 
rock in the whole course of the river, if it has yielded anything 
unusual it ought to form a reef rather than a depression. 

Doubtless the thought will come to a reader, as to the char- 
acter of the Hudson valley opposite New York. Thus far 
only the records of wash-borings have been published, and of 
these the deepest is 300 ft. at a point 2,000 ft. off the bulkhead 
at 57th street.* Yet there is reason to anticipate something 
like 700 ft. or more to bed-rock, and the hope may be expressed 
that some future exploration for an engineering enterprise will 
give the actual determinations. 


Postscript.—Since July 15, when the above pages were completed, addi- 
tional data have been obtained at the Storm King Crossing as follows (com- 
pare fig. 16): Hole 22 has caught the granite at 507’, indicating that the 
profile of the eastern bottom flattens from hole 19 to this point, more than 
as sketched. Hole 20 is 626’ and is in fine sand and clay. Hole 21 had 
penetrated 4 to 5 feet in a granite ledge or bowlder when temporarily stopped 
by the collision of atow. Thusthe extreme depth has not yet been reached 
and appears to be beneath the middle of the river near Hole 20. 


August 31, 1908. 


* Cited by W. H. Hobbs in U.S. Geol. Survey Bulletin 270, p. 31, from 
Ch. McDonald, Engineering News, xxxiii, 159, 1895. 


324 C. Barus—-Thomson’s Constant. 


Art. XXXV.—Thomson’s Constant, e, Found in Terms of 
the Decay Constant of Lons, within the Fog Chamber ; by 
Cart Barvs. 


1. Lntroductory.—In the last paper,* an account is given of 
certain tentative experiments to determine Thomson’s elec- 
tron, by aid of the fog chamber and a separate well-leaded 
eylindrical electrical condenser. The results obtained for e 
agreed well with the accepted values. It was shown that the 
constants of coronas are determinable from purely optical 
consideration of diffraction and interference, and that the 
accuracy of the method may be enhanced by using the mer- 
eury lamp as a source of light for the coronas. There was, 
however, one grave misgiving; inasmuch as the distribution 
of ionization within the fog chamber varies in marked degree 
from place to place, for any given position of a sealed radium 
tube, and that the mean value assumed was in a measure 
oratuitous. The results seen in the fog chamber are a com- 
plication of the effects of primary and secondary radiations 
together with a very marked exhaustion displacement of the 
ions. The maximum ionization does not coincide, as a rule, 
with the position of the radium, and there is no reason why 
the ionization in the fog chamber should be quite. identical 
with the ionization produced by the same radium tube in the - 
electrical condenser, unless both are one in the same apparatus. 
This is the case in the experiments of the present paper. 

2. Electrical condenser—fog chamber.—lt is therefore 
necessary to make the fog chamber itself an electrical condenser, 
and this is easily done if the chamber is cylindrical, by install- 
ing a tubular core of aluminum closed in the inside of the 
chamber and running axially from end to end. This core is 
charged to a definite potential and made the inner surface of 
the condenser, while the scrupulously clean inner wall of the 
glass chamber (to which water adheres easily) is the outer sur- 
face and put to earth. Finally the radium, contained in small 
sealed tubelets of aluminum, is placed within the length of the 
axial aluminum tube or core, in such a way as to make the 
ionization within the fog chamber uniform,—a condition 
vouched for in case of the oceurrence of uniform coronas on 
exhaustion, from end to end of the chamber. 

There are thus three currents to be determined. (1) The 
conduction current due to inevitable leakage between the 
condenser surfaces. This is made a minimum and nearly 
negligible in value, by keeping the aluminum core out of the 


*C. Barus: This Jour., xxvi, pp. 87-90, 1908. 


C. Barus—Thomson’s Constant. 325 


condenser except when not in use and by sheathing it with an 
annular air space beyond the condenser. It is found experi- 
mentally, by direct measurement in the absence of radium. 
(2) The current resulting from the ionization of the room air 
near the fog chamber and on the outside of it, due to gamma 
rays. This is made a minimum by allowing the thin wire 
communicating with the electrometer to run axially away ° 
from the fog chamber; for the gamma rays, in spite of their 
penetrating power, are quickly reduced by distance. This 
eurrent is found in the presence of radium within the axial 
tube, by leaving all adjustments identically in place, but break- 
ing the metallic connection between the aluminum core and 
the electroscope, etc., by a hard rubber insulator. If an 
auxiliary condenser is used, the measurement (1) must be 
made without it, as otherwise its leak would be counted twice. 
Fortunately the conduction current is relatively quite negli- 
gible. (5) The current due to ionization within the fog 
chamber... This is found by deducting from the total current 
found on connecting the charged aluminum core and the elec- 
trometer, the two preceding currents. 

3. Auxiliary condenser.—To vary the experiments to the 
extent that different speeds of leakage may be obtained, as 
well as to find the capacities of the electrometer and fog 
chamber, an auxiliary condenser must be inserted as a part of 
the electroscope. This condenser consisted in the present 
experiments of two plates of brass, having an area of 315°4™, 
and usually kept at a distance of °382™ apart by outrigged 
feet of hard rubber, which stood on a plate of glass. By put- 
ting small glass plates under these feet, this capacity could be 
varied at pleasure. The usual equation was corrected by aid 
ot the factor 


1+ (d+din 16 Var (d + 0)/@ + On (d + 8) /0)/rV/ar, 


where @ is the area, d the distance apart and @ the thickness 
of the plate of the auxiliary condenser. Naturally a guard 
ring condenser would have been preferable for standardization, 
but none was at hand. 

To determine the very small capacity C of the electroscope- 
fog-chamber, two successive full charges from the lighting 
circuit, at a potential V=250 volts, were in turn imparted 
from C’ to the auxiliary of capacity C’. If V” be the potential 
observed after these two charges and S= V"/(V— V"), © 
C= 8S/(1+ V1+4+S). It is curious that this method of 
successive charges leads to complicated cubic, quartic, quintic 
equations, etc., which follow no simple rule. The ratios /? of 
the potentials after four and after two charges 2 = V"’”’ / V" 
is however still available. Apart from these complications, 


326 C. Barus— Thomson's Constant. - 


the large deflections obtainable after many successive charges 
would, in the absence of conduction leakage in the condensers, 
make this method very satisfactory. 

In the definite measurements, however, almost the whole 
capacity may be placed in the auxiliary condenser, so that the 
capacities of the electrometer and fog chamber are of small 
‘importance. Ratios of C’/C= 86/17, 30/17, 20/17, and others, 
were tried. 

4. Method.—In the preceding paper the value of e found 
was ultimately dependent upon the velocity of the ions in the 
unit electric field. In the present experiments a value will be 
investigated, based on the decay constant b6=1:1 107°, of the 
ions. This method has the advantage that large core poten- 
tials are admissible in the electrical condenser, so that an 
ordinary graduated Exner electroscope suffices for the meas- 
urement of current. The small capacities of the instrument 
make it necessary to insert an auxiliary condenser, as other- 
wise the discharges are too rapid for trustworthiness. 

If @ is the number of ions produced per second per cubic 
centimeter by the radium placed within the condenser core, 
and /V the number of nuclei (ions) found when the core is free 
from charge, dn/dt=a—bNW’=0. Again if n is the number 
of nuclei found when the core is charged and 7 the corrected 
current observed, ¢ Thomson’s constant and v the effective 
volume of the fog-chamber-condenser, dn/dt=b( V*—n’*) —t/ev 
=(. Hence if the capacity of the system is C and V the 
corrected fall of potential per second 

e= OV/(bv(N*—n’)) 
Usually V is measured in volts, so that V/300 replaces V in 
the equation. It is obvious that V must be large enough to 
keep the current V constant, and the observations always show 
this at once. 

5. Data disregarding external gamma rays.—The alu- 
minum foil electroscope made it convenient to use the high 
potentials of the electric lighting circuit (about 250 volts) for 
charging. 

The number of nuclei (ions) found in the exhausted fog 
chamber free from charge, at its central core, was V=474,000. 
The number of nuclei found in the exhausted fog chamber 
when the core was charged to 250 volts was n’=82,500. Hence 
about 391,000 vanished in the presence of the electrical cur- 
rent, the original apertures of the coronas being reduced 
from about 22 degrees to 18 degrees. The drop of pressure 
6p/p='30 nearly, was taken high enough to catch all the ions, 
but not so high as to catch the vapor nuclei of dust-free wet 
air. 


O. Barus—Thomson’s Constant. 327 


The amount of exhaustion was equivalent to the volume 
ratio v,/v=1:29. Thus the number of ions in the fog chamber 
at atmospheric pressure was V=611,000 per cubic centimeter 
for the uncharged core and n=106,000 for the charged core. 
Hence WV*—7’ is about 362 10°. 

The value of 6=1:1X10° is taken from Prof. Rutherford’s 
book. The source of light for the corona is part of a 
Welsbach mantle, as usual, and the old constants of coronas 
were used, since it is a part of the purpose of this paper to 
test those constants. The volume of the fog chamber was 
estimated at 51,000 °°". In the first experiments, the effect 
of the gamma rays penetrating into the air on the outside of 
the fog chamber was neglected and the data on using different 
condensers were as follows, all data being given in electrostatic 
units. ( denotes the capacity of the system, V the drop of 
potential per second, 2 the corrected current passing through 
the condenser fog chamber. 


C Vx 10° aX 10° ex 10" 
1038 10 103 b°] 
47 21 101 5°0 
47 19 92 4°5 
LT 40 70 3°4 


the last observation being made without an auxiliary con- 
denser. The current ¢ was quite constant throughout the 
voltage interval (near 250 volts) of observation. Hence the 
effect of gamma ray penetration has seriously increased the 
leakage, and ¢ therefore appears too large, except in the last 
observation, where 2 is probably no longer measureable. 

6. Further data.—In the following experiments the effect 
of the external gamma rays was eliminated as specified in § 2. 
The conduction current was usually quite negligible. The 
nucleations observed in the exhausted fog chamber were n= 
82,000 and WV*=506,000, when the core was charged and un- 
charged, respectively. The exhaustion was again equivalent 
to a volume increase of v,/v=1'29. Hence in the fog chamber 
full of air the respective nucleations are V=653,000 and n= 
106,000, whence V?—7’?=415 x10". 

The electrical measurements, if all data are given in electro- 
static units, may be summarized as follows: 


HG. Vio: Oye BX NO" 
103 7°5 Ti 3°3 
47 17°2 81 3°5 
37 19°6 72 ; 


3°] 
Li 33° 58 2°5 


/ 


328 C. Barus— Thomson's Constant. 


Thus with a correction for the external gamma radiation, 
the data for ¢ show reasonable values, in spite of the simplicity 
of the experiment. It follows, therefore, that even in the 
ease of such large numbers of ions as occur in these experi- 
ments (over 500,000), both positive and negative ions must 
have been caught in the fog chamber and that the constants of 
coronas used heretofore are substantially correct. In case of 
the last value ex10°=2°5, for the small capacities of 17°, 
the aluminum leaves on the electroscope converge too rapidly 
for measurement, so that the air resistance may have produced 
an appreciable discrepancy. Hence both 2 and e are too small. 
No refinement has been attempted in these experiments, their 
chief purpose being to test the standardization of the fog 
chamber in terms of coronas and the degree to which positive 
and negative ions may be caught even at very high nucleation. 
One may note in conclusion that the currents of the order of 
~=7 electrostatic units or 2°6 x10" amperes, are already quite 
within the reach of the sensitive galvanometer.* 

My thanks are due to Miss L. B. Joslin, for assistance 
throughout this investigation. 


Brown University, Providence, R. I. 


W. A. Drushel—Cobalti-Nitrite Method. 329 


Arr. XXXVI.—The Application of the Cobalti-Nitrite 
Method to the Estimation of Potassium in Soils; by W. 
A. DRvUsHEL. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—exce. ] 


Ty a previous paper* from this laboratory it was shown that 
potassium may be estimated with a fair degree of accuracy by 
precipitating it as potassium sodium cobalti-nitrite in a solution 
acidified with acetic acid and oxidizing the precipitate with 
standard potassium permanganate. In the same paper the 
applicability of the method to the estimation of potassium in 
commercial fertilizers was shown by a series of experiments. 

In the method as previously worked out an excess of con- 
centrated sodium cobaltinitrite solution acidified with acetic 
acid is added to a neutral solution of a potassium salt, and the 
mixture is evaporated to a pasty condition on the steam bath. 
After cooling, the residue is stirred up with sufficient cold 
water to dissolve the excess of sodium cobalti-nitrite. The 
precipitate, consisting of K,NaCo(NO,),.H,O, is filtered on a 
rather close asbestos felt in a perforated crucible and well 
washed with cold water, or preferably with a half saturated 
sodium chloride solution. The precipitate and felt are trans- 
ferred to an excess of standard N/10 or N/5 potassium permap- 
ganate which has been diluted to about ten times its volume and 
heated nearly to boiling. If particles of the precipitate stick 
persistently to the walls of the crucible and cannot be removed 
with a spray of water, the crucible is put into the permangan- 
ate solution. After stirring for a few minutes the solution is 
gradually acidified with 5° to 20°™* of dilute sulphuric acid, 
and the oxidation is allowed to go to completion, a process 
which seldom requires more than five minutes. If no parti- 
cles of the yellow precipitate settle out on standing a minute, 
the oxidation may be considered complete. The hot solution 
is then bleached by running in a measured amount of standard 
oxalic acid, containing 50°™* of concentrated sulphuric acid per 
liter. The solution after bleaching is titrated to color with 
standard permanganate in the usual manner. 

In this process the cobalt in the molecule is reduced from 
the trivalent to the bivalent condition and not reoxidized, 
consequently from the molecule of the potassium sodium 
cobalti-nitrite we find 0:000857 grm. K,O equivalent to 1°™* of 
strictly N/10 potassium perman eanate. This factor of course 
must be corrected for any variation in the normality of the 
permanganate solution used. 


* This Journal, xxiv, 4383, 1907. 


330 W. A. Drushel—Cobalti-Nitrite Method. 


For the extraction of the alkalis 10 grm. of dry soil are 
placed in an Erlenmeyer flask with 25° to 35%° of about 20 
per cent. hydrochloric acid. The flask is thoroughly shaken 
and a small funnel is hung in its neck to avoid too great a loss 
of acid by evaporation. The contents of the flask are digested 
on the steam bath for 24 hours. 

From this point several methods for the final preparation of 
the sample were tried with satisfactory results, given in the . 
table. Since duplicate estimations were to be made by the 
gravimetric chlorplatinate method, for which it was necessary 
to remove the iron, aluminum, calcium, magnesium, phosphoric 
acid and ammonium salts, if present, from the soil extract, the 
following general procedure was found to be most expeditious. 
The soil extract was filtered through paper into an evaporating 
dish and the residue was washed with boilmg water until the 
filtrate gave no reaction for chlorine with silver nitrate. The 
filtrate was evaporated almost to dryness to remove the excess 
of hydrochloric acid as far as possible. The residue was dis- 
solved in about 200°" of water and, after heating to boiling, 
a little ammonium hydroxide and ammonium oxalate were 
added. The mixture was boiled a minute, settled, filtered and 
the precipitate was washed with hot water until a drop of the 
filtrate give no chlorine reaction. ‘The filtrate was concentrated, 
transferred to a 200° flask, cooled, and made up to the mark. 
After thoroughly shaking, 50° aliquots were pipetted off for 
the gravimetric and volumetric estimations. The aliquots were 
evaporated to dryness in platinum dishes, and gently ignited 
to remove the ammonium chloride. After cooling, the residue 
was moistened with dilute sulphuric acid and again ignited, 
gently at first and finally at the full heat of the Bunsen flame, 
to remove the last trace of ammonium present as the sulphate, 
and to destroy any organic matter which might be present. 

The residue for the gravimetric estimation was dissolved in 
a little water and a few drops of hydrochloric acid over the 
steam bath, and the estimation of the potassium was made 
according to the modified Lindo-Gladding method. 

To dissolve the residues for the volumetric estimations a 
little water and a few drops of acetic acid instead of hydro- 
chlorie acid were used. In the volumetric work approximately 
N/5 potassiuin permanganate was used, 26:08°™ of permangan- 
ate being equivalent to 50°° of exactly N/10 oxalic acid. 
From this ratio the factor for K,O was found to be 0:001642. 
In each case the potassium was precipitated as the cobalti- 
nitrite by evapurating off with 10°* of sodium cobalti-nitrite 
prepared according to the method of Adie and Wood.* 


* Journ. Chem. Soc., Ixxvii, 1076-80 (London). 


W. A. Drushel— Cobalti-Nitrite Method. ao 


Character Soil taken K,0 found 
No. of soil grm. Method erm. per cent. 
TP. Clay (1) 2°5 vol. 0°0028 Orrt 
2 ai eG 0°0035 0°14 
(3) ce gray. 0°0035 0°14 
hh. Clay = () a Vv. 0°0100 0°39 
(2) 3 6 00092 0°37 
(3) o g. 0°0098 0°37 
III Loam (1) . v. 0°0074 0°30 
(2) % SS 0:0068 0°27 
(3) ee g. 0°0075 0°30 
EV Loam (1) e v. 0°0060 0°24 
(2) Es a 0°0058 0°23 
(3) $ g. 0°0058 0°23 
V Gravel (1) v. 0°0042 0°17 
(2) er g. 0°0045 CRIS) 
VI Gravel (1) og Vs 0°0047 0°19 
2 os rs 0:0044 0°18 
ts} a g. 0°0050 0°20 
Clay (1) & v. 0:0048 0°19 
VII Gravel (2) a g. 0:0046 018 
(3) Vv. 0:0045 0°18 
(4) “6 e 0:0040 0°16 
(5) aS 0°0044 0°18 


The following exceptions are to be noted to the general 
method previously outlined for the preparation of the sample. 
In I the excess of hydrochloric acid, the iron, aluminum and 
calcium were removed from the separate portions after aliquot- 
ing, and in (1) and (2) sodium carbonate was used instead of 
ammonium hydroxide and ammonium oxalate for the removal 
of the iron, aluminum and calcium. In V (1) and (2) bases 
other than the alkalis were removed in the separate aliquots 
by ammonium hydroxide and ammonium oxalate. In VII 
the aliquots were made directly from the hydrochloric acid 
extract. That of VII (2) was treated in the usual manner 
for the gravimetric estimation of potassium. The other 
aliquots of VII were evaporated to dryness and gently ignited 
to remove any ammonium chloride present and to char the 
organic matter. The residues were extracted with hot water 
and a little acetic acid, filtered and evaporated with sodium 
cobalti-nitrite in the usual manner. 

In this work the results are based on a small amount of soil 
(2°5 grm.) in each case because but a limited amount of each 
sample was available. A higher degree of accuracy may be 
secured by using 10 grm. of soil for each estimation instead of 
2°5 grm. 


332 W. A. Drushel—Cobalti-Nitrite Method. 


Summary. 


A weighed amount of dry soil is extracted with an excess 
of hydrochloric acid over the steam bath. The excess of acid 
is removed from the extract by evaporation. The bases which 
might interfere with the process are removed with sodium 
carbonate or ammonium hydroxide and ammonium oxalate. 
Ammonium salts and organic matter are removed by ignition. 
The residue is dissolved in a little water and a few drops of 
acetic acid, and the mixture evaporated with an excess of 
sodium cobalti-nitrite to a pasty condition, stirred up with cold 
water, and filtered upon asbestos in a perforated crucible. The 
precipitated potassium sodium cobalti-nitrite is washed with 
half-saturated solution of chloride, and treated with an excess 
of permanganate in hot dilute solution. The color of the per- 
manganate is destroyed by an excess of standard acidulated 
oxalic acid, and the excess of oxalic acid titrated to color with 
permanganate. 


Edgar— Estimation of Chromic and Vanadie Acids. 333 


Arr. XX XVII.—The Llodometric Estimation of Chromic and 
Vanadic Acids in the Presence of One Another; by 
GraHAM Enear. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—cxci. | 


Tue difficulties which are met in the separation and gravi- 
metric estimation of chromium and vanadium have led to various 
attempts to accomplish the estimation of these elements in the 
presence of one another. In 1898 Hillebrand* proposed a 
method based on the fact that chromium may be accurately 
estimated when present in small quantities by comparison of 
the color of the solution containing an alkali chromate with 
that of standard solutions of potassium monochromate. If 
then the solution be reduced with sulphur dioxide and the 
excess removed by boiling, vanadium, if present, may be esti- 
mated by titration with standard potassium permanganate. 
This latter process, however, is open to the cbjection that if 
titration be made in the hot solution an appreciable amount of 
chromic salt is oxidized, while if the solution be cold the end 
point is more or less uncertain. If, however, a correction be 
made for the permanganate used up in partially oxidizing the 
chromium, the method is accurate for the small quantities of 
vanadium found in rocks. 

A method has been also proposed by Campagnet for the 
estimation of these elements in the same solution, in which the 
vanadium is estimated by titration with potassium permanga- 
nate after reduction with hydrochloric acid and subsequent — 
treatment with concentrated sulphuric acid to convert the 
oxychloride into oxysulphate. The solution is then boiled 
with an excess of strong potassium permanganate, the excess 
of reagent destroyed by the addition of a piece of filter paper, 
and the oxides of manganese filtered off, the filtrate containing 
the vanadium as vanadate and the chromium as chromate. 
Ferrous ammonium sulphate in excess is now added and this 
excess determined by titration with. potassium permanganate, 
the difference being of course the amount of ferrous salt used 
up in reducing the chromic acid, thus allowing the chromium 
to be calculated. 

The definiteness with which vanadic acid is reduced to 
different stages of oxidation by means of varied reducing 
agents makes it especially suited for processes of differential 
reduction, in which the substance to be analyzed is treated 
with two or more reducing agents whose action upon the 
constituents to be estimated is different. The latter are then 
calculated from the determination of the total reducing effect 
in each case. 

* Journal Amer. Chem. Soc., 20, 461-465, 
¢ Bull. Soe. Chim. (8), xxxi, 962-965. 


Am. Jour. Sci.—FourtH Srrizs, Vou. XXVI, No. 154.—Ocroser, 1908. 
24 


3384. Ldgar—LKstimation of Chromic and Vanadic Acids. 


That vanadic acid is reduced under proper conditions to the 
state of tetroxide by hydrobromic acid has been shown by 
Holvescheit,* and that the reduction may be carried to the 
state of trioxide by hydriodic acid has been shown by Fried- 
ham and Euler,t by Gooch and Curtis,t and by Steffan.§ 
Chromic acid, however, is reduced to a chromic salt by both 
hydrobromie| and hydriodic acid. In 1895, Friedheim and 
Euler], in connection with their work upon the estimation of 
vanadie and molybdie acids, suggested that vanadic and chromic 
acids might be estimated in the presence of one another by a 
process based upon the differential reducing action of hydro- 
bromic and hydriodic acid: but inasmuch as no experimental 
data were given and as none have appeared on the subject in 
the thirteen years now elapsed, the present writer has considered 
himself justified in investigating the feasibility of such a process. 

The apparatus used will be briefly described. As reduction 
flask served a 100°™* Voit flask, to the inlet tube of which was 
sealed a small separatory funnel, serving for admission of acid 
to the flask and for the entrance of a current of pure hydrogen 
gas from a Kipp generator. To the outlet tube of the Voit 
was sealed a Drexel bottle, provided with a Will and Varren- 
trap trap, the two serving as absorption apparatus for the 
bromine and iodine liberated in the process. 

The experiments were carried out as follows: Portions of 
standard solutions of sodium vanadate and potassium bichro- 
mate were measured into the Voit flask, one to two grams of 
potassium bromide were added, and the flask connected with 
the absorption apparatus containing a solution of potassium 
iodide made alkaline with sodium carbonate or sodium hydrox- 
ide, and the whole apparatus filled with hydrogen gas. Fifteen 
to twenty cubic centimeters of concentrated hydrochloric acid 
were added through the separatory funnel and the solution 
boiled for ten minutes, the reduction having been found’to be 
always complete in that time. A slow current of hydrogen 
was maintained to avoid the “sucking back” of the liquid 
from the Drexel bottle. The apparatus was disconnected, the 
Voit flask placed in a beaker, containing cold water, and the 
alkaline solution in the absorption apparatus cooled by running 
water. The contents of the trap were washed into the Drexel 
bottle and the solution therein made slightly acid with hydro- 
chlorie acid. The lberated iodine was titrated with approxi- 
mately N/10 sodium thiosulphate and the color brought back 
by a drop or two of N/10 icdine solution, after the addition 
of starch. The results of this titration are given in the follow- 
ing table: 

*Tnaug. Diss. Berlin, 1890. + Ber. Dtsch. Chem. Ges., xxviii, 2067-2073. 


t This Journal, ii, 156-162. § Treadwell, Quantitative Analysis, p. 327. 
| Farsoe, Zeitschr. Anal, Chemie., 1907, 308-310. *| Loe. cit. 


Edgar—FEstimation of Chromic and Vanadie Acids. 335 
(I) (11) 
V2.0; CrO3 NaeS203 Na.S.Os Error Error 
No. taken taken on on 
of as as N/10x1:031 = N/10x1°081 V,0; CrO; 
Expt. NaVO; K.Cr.0; 
grm. erm. em? em? grm. grm. 
(1) 01528 .-.. 16.20 16°22 tI) 4 Fae apie tne 
(ewe 015285." 022. 16°19 16°20 {ir} BY ou eee 
23) OLE eee 21°59 21°58 ti) 1 cena Bhd 
( 4) 0°1523 0°0685 36°08 16°22 +0°0002 —0°0001 
(5) 0°1523 0°0685 36°10 16°20 +0°0000 +0°0000 
( 6) 0°1523 0°0085 . 36°12 16°17 —0°0003 +0°6002 
( 7) 0'1523 0°0685 36°07 16°20 +0°'0000 —0:0001 
( 8) 0°1523 0°1370 56°00 16°17 —0°00038 +0°0001 
( 9) 0°1523 0°1370 56°02 16°22 +0°0002 +0°0000 
(10) 071523 0°1370 56°03 16°19 —0'0001 +0:°0001 
N/10 x 0:992 N/10x 0:992 — Changed Stand. of Na2S.Os 
(11) 0°2031  0°1370 63°82 22°46 +0°0000 —0O:0001 
(12) 0°2031 0°1370 63°80 22°48 +0°0002 —0:0003 
(13) 0°1016 0°0685 32°00 11°25 +0°0002 +0:0001 
(14) 0:1016 0°0685 31°92 11°24 +0°0001 —0:0001 
(15) 0°1016 0°0685 31°90 11°25 +0:0002 —0°0002 
(16) 0°0508 0:03843 15°95 5°63 +0°0002 —0°0001 
(17) 0°0508 0°0343 15°95 5°62 +0°0001 —0-0001. 


Alkaline potassium iodide was again placed in the absorption 
apparatus and the latter connected with the Voit flask. The 
eurrent of hydrogen was turned on and, after all air had been 
expelled, the apparatus was disconnected momentarily, one or 
two grams of potassium iodide were added to the solution in 
the Voit flask, and connections made again. Through the 
separatory funnel ten to fifteen cubic centimeters of concen- 
trated hydrochloric acid and three cubic centimeters of syrupy 
phosphoric acid were added and the solution in the reduction 
flask was boiled to a volume of ten to twelve cubic centime- 
ters. The absorption apparatus was removed and cooled, 
hydrochloric acid was added and the liberated iodine titrated 
with approximately N/10 sodium thiosulphate. The results 
of this titration are given under II, Table I. It is evident 
that the iodine determined in the first titration corresponds to 
reduction of the chromic and vanadic acids corresponding to 
the equation, 


V,0,+2CrO,+ 8HBr=V,0,+ Cr,0O, + 81+4H,O0 


while in the second case the iodine corresponds to a reduction 


336 Hdgar—Lkstimation of Chromic and Vanadie Acids. 


of the vanadium tetroxide to trioxide as indicated in the 
equation, 
V,0,+2HI=V,0,+21+H,0 

The second titration, therefore, determines the vanadiec acid 
present, and the difference between the first and second far- 
nishes the necessary data for the calculation of the chromium. 

From the small error shown in the results of Table I it is 
evident that vanadic and chromic acids may be accurately 
estimated in the presence of one another by the differential 
reducing action of hydrobromie and hydriodic acids under the 
conditions used above, the liberated halogen being absorbed in 
potassium iodide solution and the iodine titrated with sodium 
thiosulphate. 


FL. Ransome—Apatitic Minette. 337 


Art. XXXVIIL.--An Apatitic Minette from Northeastern 


Washington ;* by FrRepreRiIcK Les~iz Ransome. 


In the course of a rapid reconnaissance along the Northwest 
Boundary in the summer of 19V1, numerous dark micaceous 
dikes were noted on both sides of the Columbia River, between 
the smelter-town of Northport, Wash., and the settlement of 
Waneta, at the mouth of Pend d’Oreille River, in British 
Columbia. These dikes cut a series of sediments of unknown 
age, possibly Carboniferous, consisting of steeply inclined dark 
slates, banded schistose limestones, and subordinate quartzites. 
Similar dikes were noticed for 12 miles eastward along the 
Pend d’Oreille and as far west as Kettle River, which crosses 
the boundary about 40 miles from Waneta. Not all of these 
dikes have been carefully studied, but most of them appear to 
be minettes or rocks closely related to this type. One speci- 
men from a particularly micaceous dike at the mouth of Sheep 
Creek, on the northwest bank of the Columbia opposite North- . 
port, has been analyzed by Dr. W. F. Hillebrand and found 
to be of rather unusual chemical character—enough so, it is 
thought, to warrant the publication of the analysis with a 
petrographical description. 

The rock is dark, greenish gray, by far the most prominent 
constituent in hand specimens being the closely crowded scales 
of biotite up to 4 or 5 millimeters in diameter. The other 
mineral constituents form in general a fine-grained matrix to 
the biotite and are not individually distinguishable without a 
lens. Parts of the rock, however, contain irregular light- 
colored streaks in which the feldspar is a little more distinct 
than elsewhere. 

Under the microscope the rock shows a poikilitic texture, 
large irregular areas of optically continuous feldspar being 
crowded with automorphic crystals of biotite, pyroxene, apa- 
tite and titanite. The feldspar is chiefly orthoclase, although 
much of it is not optically homogeneous and some evidently 
contains microperthitically intergrown albite. It is all more 
or less turbid with minute, brown, dust-like inclusions. The 
biotite is chestnut-brown in most sections with the usual 
strong absorption parallel with the cleavage. The axial angle 
is small and the interference figure shows no distinet opening 
of the lemniscate cross into hyperbolas. The pyroxene, which 
is automorphic in the prism zone with occasional terminal 
planes, is monoclinic with a maximum observed extinction of 
Zac of about 45°. It is colorless to very pale green, non- 
pleochroic and is probably an augite near diopside in compo- 


* Published by permission of the Director of the U. S. Geological Survey. 


338 I. L. Ransome— Apatitic Minette. 


_ sition. The pyroxene is for the most part fresh, but some 
crystals have undergone slight partial alteration into green 
hornblende and calcite. The apatite occurs in stout prisms up 
to two millimeters in length and is noticeably abundant as seen 
in thin sections. It is included chiefly in the orthoclase and 
biotite, although the augite is not free from occasional prisms. 
Rather abundant titanite and a little magnetite and pyrite 
make up the minor constituents. 

~ The chemical analysis of this rock by Dr. Hillebrand is as 
follows : 


Chemical Analysis of Minette. 


Oi ws ee ee PA Boos. jose ee 
PIB O SG po bn Ree setae 2D OOD Or. 0) oe cee ae a 04 
Bie O) 2 cave Geant 8 4°06); i NIO) 2b 200s eee eee eee 02 
MeO irae nies Te 404 UF iy Mins 2 ee eee 25 
MoO. tues ow ek 8:65. (BaO. ve te 44 
CAO ra tek eee amet ermal MeN) SrOe 2533 22 11 
INO) se a dete 157 Li,O 0. ue a trace 
1G a EE DESC SRR Ss 6°10 NOC Se ee 04 
EO) ee eget ee 1°54 HeS,.. 2-0 2202 Oe 
|e ROY? Sa a 2°30 

TOU Wee 2°36 100-01 
DV OES oes ESE ae 502 Ikess-O'for Fl, Cl. Sea 11 
WO Nae eee Wee 1:24 

Phaadirces Uiaeive Sale 4-05 99°90 
Ol ites ase Bani te eee AO 


In comparison with most minettes the analysis of the rock 
here described is low in silica and alumina, rather high in 
potash and titania, and remarkably high in phosphoric acid. 
This last feature, indeed, is the most noteworthy peculiarity of 
the rock. Out of the 2112 rocks of which superior analyses 
are collected in Washington’s tablest only 59, or 2°7 per cent, 
contain over 1 percent of P,O,. Of these only 10 contain over 
2 per cent, and, of these 10, only 2 have over 3 per cent of P,O,, 
namely a pyroxene-apatite-syenite (orendase) from Finland, 
described by Hackman,t with 5-98 per cent of P,O, and an 
avezacite (avezaciase) from the Pyrenees described by Lacroix§ 
with 3°32 per cent of P,O,. | 

The norm as calculated from the chemical analysis and the 
place of the rock in the quantitative classification are as 
follows : 


* Not corrected for influence of V2Os. 

+ Washington, H.S. Chemical analyses of igneous rocks. Professional 
Paper U.S. Geol. Survey No. 14, 1903 ; Superior analyses of igneous rocks. 
Professional Paper U. S. Geol. Survey No. 28, 1904. 

+ Hackman, V. Neue Mittheilungen tiber das Ijolithmassiv in Kuusamo. 
Bull. commission Géologique de Finlande No. 11, 1899, pp. 36-37. 

§ Lacroix, A. Les roches basiques accompagnant les lherzolites et les 
ophites des Pyrénées. Comte Rendu VIII Congres Géol. Int. 1900, Paris, 
1901, p. 382. 


FL. Ransome—Apatitic Minette. 339 


Norm. N 3° 
Or oan see Ory eairemane 
Bem. 5111 
ING 2h TE 
: 2 6 ir OT a aaa 
Ween 57 5:67 Sali 43-07 F-30330" Portugare. 

N 
ate. So 8 9 eee = 1. Wyomingase. 
i=. 29:38 ST eee 

6 ; 

Ap .-- 9°41 Fem.=51°11 Na OQ ™op= 2 Washingtonose. 
Oi 6-73 
Pipe 6°05 
CS Sena 4°56 
HeOs 23°84 
Bee. 104 
Bes, -- 06 

99°32 


This norm, as shown above, places the rock in the salfemane 
class, in the lendofelic or Portugare order, in the peralkalic or 
Wyomingase rang, and in the dopotassic subrang. It is the 
first recorded representative of this subrang, and as it falls 
well within the classificatory limits of the division, washing- 
tonosé is suggested as an appropriate subrang name. It is 
worthy of note that the wyomingite, orendite and madupite 
described by Cross* from the Leucite Hills, Wyoming, are all 
comparatively rich (1:39 to 1°89 per cent) in phosphoric acid. 

For comparison the norms of the two rocks standing nearest 
to washingtonose in Washington’s tablest are given below. 


Wyomingite (Cross). Shonkinite ( Weed and Pirsson). 
ieee 8 rete 44:5 Oy Bae eee es te! 20% 
eer ere 8) jst) 105 Pan OY gs oe oy ae Saat pm 8°9 
SNE eee Se tere led DAN TY en Us a SG begin SLT Bea) 

INC ies eye as 6°2 
The es eins en 74 
11) NO ae pained ta!) 1 Re Rates A on Se a 2859 
RSE Bi Pig So AIS ee ea 79 (Qa ee ae ane a 14°8 
Mee Ls Decpeneee eso ANT NYG os es Ae ele ee 
ein 6 Pe! eer ee tT LOPS JU oes eye ere eal em Ca ny) hea. 
2 RE or) ot Mg 4°5 LO) A ee Nea fame a ez 


* Cross, W. : Ignéous Rocks of the Leucite Hills and Pilot Butte, Wyo., 
this Journal (4), vol. iv, p. 130, 1897. 
+ Professional Paper U.S. Geol. Survey No. 14, p. 339. 


340 Lf. L. Ransome—A patitic Minette. 


The wyomingite is in the perpotassic subrang and the shonk- 
inite in the sodipotassic subrang of the wyomingase rang. 

None of the minettes of which reliable chemical analyses 
are available falls near washingtonose in the quantitative clas- 
sification. The three rocks of this type included in Washing- 
ton’s tables contain from 50°81 to 52°26 per cent of silica. 
Consequently they are all in the dosalane class. Owing to 
their relative richness in silica and alumina as compared with 
the rock here described, their norms are more feldspathic and 
all are in the perfelic.or Germanare order. These norms, from 
the tables, are as follows: 


Norms of Minettes. 


I 16 III 
AS) he ES Se ys ae DASA Pi peeg anc est 1 95°67 er 41-4 
AD sc Se eee Bet LO BEG. Gain pein earn 39°02 ala 8:4 
EAM Ce ree ua tere 14S eae iene aot Oise 5 eee 1671 
aN GrQe Ree a eae OPO Mi epiclhy (cutie Sarai tts S980 ee oe 
BT giyecompmaete okt ernie Lh Bibs ea Nei fae 5:3. 243 3°9 
Thy, 2) ad ie SE Be: TPIODRS PSRs oe Sete Mer mer res Bn! 
(Oca mete, 8 ay aha SiO eee ea Van 56.2 oe Sie 14:7 
Mig ce at wee aes Sc Ou pehuyprier pd ways Bed 3. lon eee 3° 
AT ape: oie Se ei ree iL pigs ocala 3° 9s ely oie iran 3°92 
Ap Su ee eo ee es AD Se Nee. or aa bee ae 1°4 


I. Augite-minette (Pirsson). Monzonose. W. T. Prof. Paper 
14, p. 255. 
II. Soda-minette (Brégger). Akerose. W. T., p. 263. 
Ill. Augite-minette (Doss). Dopotassic subrang of andase. W. 
Aree pe 205. 


All of these norms contain considerable albite, the quantity 
reaching 23°6 per cent in the augite-minette (monzonose) from 
the Little Belt Mountains, Montana, -described by Pirsson (1), 
whereas in the washingtonose here described there is no norma- 
tive albite. The three norms just given also contain much more 
anorthite than that of the rock from the banks of the Colum- 
bia, but show no normative leucite. Other differences will 
appear in comparing these norms with that of washingtonose. 

The actual mineralogical composition, or mode, of the wash- 
ingtonose described can not be accurately calculated, as the 
compositions of the augite and biotite are not known. The 
abundance of lenads in the norm, conditioned by the low silica 
and high alkalies, suggests modal nephelite. None, however, 
has been detected, while it is certain, on the other hand, that 


EF. L. Ransome—Apatitic Minette. 341 


the albite molecule is present in the feldspar. It is, therefore, 
to be concluded that the actual development of the abundant 
biotite in the rock leaves available sufficient silica to form 
albite rather than nephelite. A rough calculation of the 
mode, in which the pyroxene is figured as ideal diopside and 
the biotite as one having the ratios 

MgO FeO SiO, _ 

K.O a Ona and eee 
although not accurate enough to give the mode of the rock, 
shows that, when biotite is allowed for, the readjustment of 
the constituents locks up suflicient potash and disengages 
enough silica to raise the remaining lenads to feldspar. 


342 Palache and Warren—Krihnkite, Natrochalcite. 


Arr. XX XIX.—A7rohnkite, Natrochalcite (a new mineral ), 
and other Sulphates from Chile; by Cuarues PatacuE and 
C. H. Warren. 


THE minerals briefly described in this paper* were sent to 
the Harvard Mineralogical Laboratory for identification by the 
Foote Mineral Co. of Philadelphia, whose manager, when the 
scientific interest of the material was pointed out, at once 


placed at our disposition all of the material in his possession 
with- generous permission to use whatever was necessary for 
the investigation. 

The collection comes from the mining district of Chuqui- 
camata in the Province of Antofagasta, Chile. It was obtained 
from exhausted copper veins and includes the following species: 
krohnkite, natrochalcite (a new mineral), blodite, brochantite, 
atacamite, chalcanthite, copiatite, botryogen, sideronatrite, 
halite and gypsum. 


Krihnkite. 
Krohnkite is the most abundant mineral in the collection and 
appears in three distinct habits, as follows: 


* A more extended crystallographic description of this material will appear 
hortly in Zeitschrift ftir Krystallographie. 


Palache and Warren—Krohnkite, Natrochalcite. 3438 


Phase a.—Clusters of octahedroid crystals of the type of 
figure 1 but mostly in twin groups, the erystals firmly aggre- 
gated to a highly cellular mass, largely infilled with an earthy 
yellow iron sulphate which may be copiapite. These crystals 
reach a diameter of 1°5°" and are of a dull greenish blue 
color with smooth but lusterless faces. 

Phase b.—Single crystals and fibrous or acicular aggregates 
of pale blue. color, implanted on the white quartzose vein 
material. The crystals are slender prisms with the forms of 
figure 1 but with the prism largely developed and its planes 
much curved and facetted through the presence of steep vicinal 
pyramids. Single crystals reach a length of 4™. 


Phase c.—Solid crusts up to 2” in thickness of deep 
vitriol blue color, the crystals composing the mass often large 
and either short or long prismatic, with the forms of figure 2. 
In cavities on the surfaces of such crusts is a second generation 
of prismatic crystals of pale blue color, beautifully crystallized 
and showing the complex combinations of figures 3 and 4. 
Twin crystals of the type shown in figure 5 are also found on 
this deep blue material. 

The position adopted for the crystals differs from that given 
by Dana, front and back being interchanged. The axial ratio 
calculated from measurements on a number of crystals is 

Gane O22) bh 204357 8 = 56° -17'°20" 

The observed forms are as follows :—a(100), 6(010), (110), 
h(120), &(180), e011), d(021), f(031), ¢ (101), w(802), v(801), 
p11), 7121), g(111), s(121), w(211), #(221), 2(831), 7(551), 
0(10°10°1), 7(232), n(132). 

(Tables of measured and calculated angles and combinations 
will be found in the paper cited above. 

Twinning.—The twin plane is the base, (001). Twins 
are either contact or interpenetrating, the latter resembling 
parallel growths owing to peculiarities of angles and distortion. 


344 Palache and Warren—Krohnkite, Natrochalcite. 


Cleavage.— Cleavage is perfect and easy parallel to 0(010) 
and good but not so easily produced parallel to c(011). No 
trace of a prism cleavage as recorded by Darapsky could be 
detected. Hardness is a little less than 3, just scratched by 
the fingernail. Specific gravity is 2°06i (Warren), determined 
in absolute alcohol and calculated for water at 4°C. 

Optical Characters, determined by H. Eb. Merwin.—The 
principal indices of refraction, determined by means of the 
refractometer, are : a = 1°54387, 8 = 1-57715; y = 1600s tee 
sodinm light. 2V,, calculated from the refractive indices is 
78° 36’; from observation of the acute optic angle in ei] 78°42’, 

The plane of the optic axes is in the plane of symmetry, 
with the acute bisectrix for yellow (ether-axis @) inclined 48° 45’ 
to-the erystallographic axis ¢ in the obtuse angle 8. The dis- | 
persion, as determined by the colored hyperbolas of imterfer- 
ence figures, is inclined. The acute bisectrix for blue is 
nearer ¢ than the bisectrix for red. The optic axes also are 
slightly dispersed, more for blue than for red, as indicated by 
broader color fringes on the hyperbola emerging nearly per- 
pendicular to ¢. 

Chemical Composition, with analysis by C. H. Warren.— 
Analysis of the very pure material available confirms the com- 
position of the mineral as given by earlier writers. 


CuSO,.Na,SO, +2H,0. 


Most of the water is given off below 150°. Small additional 
amounts continue to come off up to 350°, when dehydration is 
complete. The residue may be brought to complete fusion 
without further decomposition, yielding a bright green enamel. 


Per cent. Mol. Ratio. Theory. 
a ee SS, 

CiOe 325 "292 “98 23°49 

Na,O 18°89 °304 F-O02 18°39 

SO, 47°60 "595 2°00 A744 

H,O TORT "095 2:00 10°68 


Atacamite trace 


100°46 100°00 


Paragenesis—Krobnkite is the most abundant sulphate 
in these specimens and the first to be formed. Atacamite 
alone of the few associated minerals may be older, thin crusts 
of it sometimes lying between the krohnkite and the vein 
matrix. Crystals of kréhnkite also show occasional inclusions 
of copiapite, brochantite and atacamite; none of the other 
minerals mentioned above as occurring in the collection 1s 
found with krohnkite. 


Palache and Warren—Krohnkite, Natrochalcite. 345 


Natrochalcite, a new mineral. 


Bright emerald-green crystals of what proves to be a new 
hydrous double sulphate of copper and sodium were found on 
several specimens. The crystals are either isolated or in closely 
adhering crusts upon the white vein matrix; in one specimen 
they are embedded in chaleanthite and doubly terminated erys- 
tals were obtained by carefully breaking away the enclosing 
blue vitriol. The mineral is monoclinic with a striking pyra- 
midal habit, shown in figure 6; the crystals attain a length 
of about 1™ and are generally attached to the matrix in such 
a way that portions of both prism and pyramid are developed ; 


an oscillatory striation parallel to intersection edge of these 
forms, due to the development of steeper pyramids between 
them, is generally well marked. A small basal pinacoid and 
the other faces shown in figure 7, but of minute size, are 
generally present. The faces proved to be of good quality in 
most cases and the measurement of six crystals, mostly very 
small and one of them doubly terminated, yielded satisfactory 
data for calculation of the elements. For this purpose 45 
faces of seven forms were available. 


p= "8526 —— 1:065 = (arilecs ea vey Oleg 
from which was calculated 
G20 76 = 1493 0-314 8 — 61° 17’ 30” 


346 Palache and War ren—Khrohnkite, Na trochulcite. 


The table contains the forms found, the angles calculated from — 
the elements and the observed angles with their range of vari- 
ation. It will be seen that the calculated and observed angles 
show a very satisfactory agreement. 3 


Natrochalcite.— Table of Angles. 


Calculated. Measured. Limits. ¢ 
CR aa PS SSS SSS — No. 
p p d p p pag of 
ped Nb eter 
C1001) 90200) 82494905 00 FOS aA eee eee 28°39’ 23°49’ 3 
6-010 00: 00: 90-00-00 00° 90 00 222) 2 eee 4 
mz 110 88 41. 90°00 $8.41 90 00:.38°40'—382%43" eee 12 


p 111 51 23 6247 5123 62 47 51 15-51 31 62°45 consol 
® 112 59 35 50 10 59 85 50 09 59 28-59 44 50 07-59 12 3 
u 221 45 45 78.58 4555 78 39 45 41-4601 73 14-74 11 5 
w 831 48°34: 78 45 48-35 78 55.0.2 1 
qg 111 19 16 5208 19 16 5208 1912 -19 20 52 06-52 10 7 
w 521 39 54 7021 35 56 7017 29 50-30 04 70 13-70 21 5 


The habit of the crystals is always dominated by the forms 
chosen as prism. and pyramid, mand p,; all other forms are 
developed with but small faces and often without the full 
number of their faces. 

Cleavage._—Cleavage is perfect and easy parallel to the base, 
(001). Hardness 4°5, scratching fluorite easily and not scratched 
by it. Specitie oravity 2°33, determined by Warren. 

Optical Characters determined by H. L. Merwin.—The 
principal indices of refraction, determined by means of the 
retlectometer, and the optic angle for sodium lght, are as 
follows: a = 1°6491, 8 =1°6555, y = 1:°7148. 2V,,, calculated 
from the refractive indices, 36° 52’; by observation of obtuse 
optic angle in oil, 36° 48’. 

The plane of the optic axes is in the plane of symmetry, the 
acute bisectrix for yellow being inclined to the crystallographic 
axis ¢ 12° in the acute angle 8. The acute bisectrix is the 
axis ¢; the mineral is therefore optically positive. Dispersion 
of the optic axes is strong, the acute optic angle for the 
strongest blue rays transmitted by cobalt glass being 3° greater 
than the corresponding angle for yellow. There is also a ) slight 
inclined dispersion of the acute bisectrix, that for blue lying ~ 
nearer ¢ than that for red. 

Chemical Composition._-The composition of the mineral 
may be expressed by the formula 


Na,SO,.Cu,(OH),(SO,), + 2H,0. 


Palache and Warren—Kréhnkite, Natrochaleite. 347 


The water is given off gradually on continued heating above 
150°. The mineral decomposes and gives off SO, between 
350° and incipient redness. Before the blowpipe it decrepi- 
tates and fuses very easily (about 1) toa black bead. Gives 
off acid water in closed tube, fusing to a dark enamel. It is 
very slowly dissolved by water and easily by acids. 

The analysis which follows was made on less than one gram 
of material and is not wholly satisfactory to Dr. Warren, the 
analyst; lack of available substance, however, except at the 
expense of one of the two remaining specimens, made it seem 
well to publish it as it stands, subject to revision later should 
more of the mineral be discovered. 


Per cent. Mol. Ratio. Theory. 

CuO 41°95 "528 4-00 42°08 

Na,O 8-44 136 1:03 8-24 

SO, 42°10 "326 4-00 42°51 

H,O 770 427 3-23 717 
Insoluble rés. aft : 


Clfrom atacamite +05 
100-94 100-00 

Paragenesis.—Natrochalcite does not occur with kréhnkite 
in these specimens, but takes its place, bearing the same age 
relations to atacamite and brochantite which occur sparingly 
with it. As above mentioned, it is embedded in chaleanthite 
in one specimen. 

Llodite.—Bloédite was identified by the following analysis. 
It is a massive granular form of the mineral, white where 
not stained blue by chaleanthite or pale green by finely divided 
atacamite. It showed no trace of crystalline form. In one 
specimen it was accompanied by halite and krohnkite. 

Composition, analysis by C. H. Warren: 


Per cent. Mol. Ratio. Theory. 

MeO 12-00 300-100 11-48 

Na,O 18°20 "296 0-98 18°56 

SO, 47-49 593 1:98 47-90 

HO 21-60 1:20 4-00 21°56 
Insol.-atacamite 
and quartz, 50 

99°70 © 100-00 


leading to the usual formula, MgSO,.Na,SO,+4H,0. 


348 Palache and Warren—Krohnkite, Natrochalcite. 


Of the remaining minerals listed on the first page as occur- 
ring in this material there is little to note of special interest. 
Brochantite is sparingly present in acicular crystals implanted 
on or surrounded by kréhnkite. Atacamite is in green and 
deep blue-black crystals of ordinary prismatic and tabular 
habits; also in erystals elongated parallel to the brachyaxis 
with nearly equal development of the forms m, e, 7 and n. 
Chaleanthite is in the form of granular crusts, copiapite and 
botryogen in granular masses of no distinct form and sideron- 
atrite in yellow needles. Halite in small cubes was present on | 
one specimen of blodite and gypsum is shown in a coarse 
granular form saturated with finely divided hematite and also 
in aborescent crystallizations of snow-white color, closely resem- 
bling cave-formations of calcite. 


Cambridge, June, 1908. 


F. E. Wright—Measurement of Extinction Angles. 349. 


Arr. XL.—On the Measurement of Extinction Angles in 
the Thin Section; by FrRep. Eugene Wricut. 


1. The Measurement of Extinction Angles of Minerals in the Thin 
Section. 

The Adjustment of the Petrographic Microscope with Special 
Reference to the Measurement of Extinction Angles. 

3. A Device for Holding Minute Crystals. 


) 


1. The Measurement of Hxtinction Angles of Minerals in the 
Thin Section. 


Tue petrographic microscope as an instrument has under- 
gone many changes and modifications since its introduction 
nearly forty years ago, but from the very first, each improve- 
ment has tended to increase its efficiency in such a way that 
the optical features of minerals in the thin section can be 
ascertained more readily and more accurately. In the hands of 
geologists, the microscope is merely the means to an end—an 
apparatus to aid in recognizing the minerals composing a given 
rock (mineral composition) and the relations of such rock 
components to each other (rock texture); and for such purposes 
the modern petrographic microscope is admirably adapted, 
especially since, as arule, approximate results only are required. 
But with the increased knowledge of rocks thus attained, the 
demand for data which are precise and quantitative in character 
rather than qualitative has become more imperative, with the 
result that, at the present time, one expects to find in a thorough 
petrographic investigation accurately determined optical con- 
stants of each of the rock-forming minerals examined, and in 
critical points, the probable. error of each determination given. 
This passage from qualitative to quantitative work implies 
consequences of profound importance; an additional burden is 
placed on the working geologist, and the time and energy re- 
quired for the investigation of a given problem is much greater 
under the present régime than formerly; at the same time, 
this transition indicates that, in one phase of geology, at least, 
the step from the lower first plane of preliminary reconnaissance 
work to the higher level of precise and detailed work is being 
taken. 

The optical properties which are made use of in the practical 
determination of minerals under the microscope are, briefly: 
refractive index, birefringence, optical axial angle, optical 
character, extinction angles, color and pleochroism. By means 
of these properties alone it is possible to ascertain the crystal 

system to which a given mineral belongs, and by a short pro- 
cess of elimination to determine definitely the mineral in ques- 


Am. Jour. Sc1.—Fourts Serres, Vout. XXVI, No. 1o4. —OcTOBER, 1908. 
25 


350 FEL Wright—Measurement of Extinction Angles. 


tion. This process has been carried to such refinement in certain 
instances, as in the isomorphous series of plagioclase feldspars, 
that it is now possible, from extinction angles alone, to deter- 
mine very closely the actual chemical composition of the par- 
ticular plagioclase in hand. 

For a given mineral plate in the thin section, the term 
extinction “angle signifies the angle between a known crystal- 
lographie dir ection (cleavage line, or trace of a crystal face on 
that plate) and one of its optic ellipsoidal axes or directions 
along which it extinguishes when these directions are parallel 
with the principal planes of the crossed nicols. In order to 
ascertain this angle satisfactorily one must be able not only to 
measure plane angles accurately, but also to locate correctly 
the position of the optic ellipsoidal axes of the particular crystal 
plate. The first condition is easily accomplished and demands 
no special comment, while the second requirement is extremely 
dificult to meet with any degree of satisfaction without great 
expenditure of time. 

Many methods have been suggested by which the position 
of the optie ellipsoidal axes of a given crystal section can be 
located more or less exactly, and all are based on the fact that 
when the optic ellipsoidal axes are parallel with the principal 
planes of the crossed nicols the plane polarized light normally 
incident from the lower nicol passes through the erystal plate 
without changing its plane of vibration. "In case the optic 
ellipsoidal axes of the plate do not coincide with the planes of 
the nicols, interference in general takes place and some light 
passes through the upper nicol. The different methods pro- 
posed have for their common object the rendering apparent 
the extremely small percentage of light which thus emerges 
from the analyzer when the angle of revolution of the crystal 
plate from its position of absolute darkness is very small. 

Before considering in detail the different methods for accom- 
plishing this result and their relative merits and defects, it will 
be well to treat the subject mathematically and to derive the 
formulas for the intensity of light with special reference to the 
subject of extinction angles. This treatment is given in some 
detail in the following paragraphs, since the deductions given 
later are all drawn from these fundamental equations. 


Theorétical. 


Mathematical—The phenomena of light are considered to 
be produced by periodic changes or disturbances in the ether, 
transverse to the direction of propagation. Different hypoth- 
eses have been proposed which assign different properties to 
this medium, but no one of the hypotheses yet suggested is 


FE. Wright—Measurement of Extinction Angles. 351 


satisfactory in ail its details.* or the purposes of this paper, 
however, these disturbances may be considered vibrations of 
ether particles about positions of rest and in a plane normal 
to the line of wave propagation. Adopting this. view chiefly 
as a matter of easy expression, we may assert that in plane 
polarized light the disturbances or vibrations are confined to 
a plane, each particle vibrating then with simple periodic 
motion, to and fro, pendulum like, along a straight line. An 
equation which satisfies such a periodic vibration and which 
has been found to represent satisfactorily the ether disturbances, 
is the following: 


Say aT 
y = Sin a (¢—7,) (1) 
. 3 : Se AE 2rt 
in which @ represents the amplitude, T the periodic time, - 


the initial phase, ¢ the time which has elapsed at any given 
instant, and ¥ the distance of the ether particle from its posi- 
tion of rest. The velocity of the ether particle at any instant 
is given by 


Qa Ase 

Some a Cle wre COSH opine aE 
eae tae re) 

and if 72 be its mass, its kinetic energy is 1/2 mv’. 
27a 
aie 9 
accordingly the average kinetic energy during a complete 
vibration will be 


1 T mor {r- ae 
af P2 modi = oe on ae dt 
1@) 


() 
mar (°T dor Ma mr bat T 
a TS COS se (SI YG a (er | 
ns _f ( sl 4 fe ( :) pe [ le Aa Tv ( ) fl 


1 TG, in. 
= 

Now, a vibrating particle possesses at any instant a definite 
amount of kinetic energy and also a definite amount of poten- 
tial energy, and the sum of these two amounts of energy 
remains constant throughout the vibration, so that as the 
kinetic energy in the particle increases its potential energy 


The above equation shows that v varies from 0 to 


* These theories, as well as the mathematical treatment of the same, are 
given in the standard text-books on light (Preston’s Theory of Light; P. 
Drude, Lehrbuch d. Optik, and many others; also Rosenbusch-Wiilfing, 
Mikrosk. Physiagraphie i, 1; and Duparc and Pearce, Traité de Technique 
Minéralogique et Pétrographique). 


352 FE. Wright—Measurement of Extinction Angles. 


decreases, and vice versa. At the moment the kinetic energy 
of the particle becomes zero, the total energy is potential, and 
similarly, when the kinetic energy attains its maximum, the 
potential energy is zero. In other words, the average poten- 
tial energy is equal to the average kinetic energy, and the 
whole energy is twice the average kinetic energy, given in the 
above expression. 

A measure for the intensity of hght is the energy per unit 
volume of the vibrating ether, and if in the above expression 
for the kinetic energy m stands for the mass per unit volume, 
the whole energy or intensity will be measured by the 
expression, 

Qin a" 


oe 


In practice, only relative intensities are encountered. The 
relative intensities of two light vibrations of equal period (T) 
at a given point will be in the ratio of the square of their 
amplitudes : 

od Da, a 2H One ae 


I = re on ue ah a aia (2 ) 


In other words, the intensity of light of a given period of 
vibration (color) varies as the square of its amplitude (@) of 
vibration. 

This relation will now be made use in determining the rela- 
tive intensities of the plane polarized light waves which 
emerge from the upper nicol of the microscope, after having 
passed through the lower nicol and an intervening crystal 
plate in different positions. 

Disturbances in the ether which produce light phenomena 
are ascribed to the action of forces on the ether mass, and if 
two or more separate disturbances are simultaneously impressed 
on the same element, the resultant disturbance can be caleu- 
lated according to the principle of the resolution of forces on 
the assumption of direct superposition of the forces. If, in the 
case of plane polarized hght, two separate vibrations be 
imposed simultaneously on an element, the resultant vibra- 
tion will also be in that plane, and its amplitude, on the prin- 
ciple of superposition, is the algebraic sum of the amplitudes 
of the components. The mathematical expression for the 
resultant vibration of a particle simultaneously impressed by 
two periodic disturbances of the same period but differing in 
phase and amplitude, can be deduced from the equations of 
the separate vibrations. 


sin 2a (t—t RG be 
cA 2) and Y,—4a, sin mune ) 


Oia 


FE. Wright—Measurement of Extinction Angles. 358 


The resultant displacement . any time ¢ is 


Y¥=Y, + Y,=4, mee (t—t,) +a, sin ; - (it) 


; ar Go 1 1.) Qa ; Hf t.) 

= sin —t(a sagen a, Coe = os asin a, ainae 
fe 7.3 The pea sin ort Tes 
== S07 22 Sy 
= ay ) 
if 
A cos ¢,=@, cos, > vt +4, os 27 t, 

and 


: fe Th eae 
A sin ¢,=a, sin a ¢. +a, sin — t, 
By squaring and adding the last two expressions, we obtain 


2 
A’=a,'+a,'+2a,a, cos 7 (¢,—¢,) (3) 


In this expression 


r 


2 bs, 
= (t¢,—t,) denotes the difference in phase 


of the two component periodic displacements and A the 
amplitude of the resultant vibration. 

In considering the effects which different crystals exert on 
transmitted light waves, it has been found, both in practice 
and theory, that these influences can be predicted accurately 
and satisfactorily by reference to a triaxial ellipsoid, the optical 
ellipsoid, the position and relative axial lengths of which vary 
in general with different minerals, and with the wave length of 
light employed. Thus the directions of vibration of light 
waves emerging normally from a mineral plate are parallel 
with the major and minor axes of the ellipse which a central 
diametral plane parallel to the given plate cuts out of the 
optical ellipsoid for the particular mineral and wave length 
used. The determination of the actual position of these 
directions in the plate is accomplished in polarized light by 
observing the relative intensity of the transmitted light for 
different positions of the plate parallel to the principal planes 
of the nicols. 

Light waves emerging from the lower nicol are plane polar- 
ized and their vibration is given by the equation 


Qxrt 
UWE i a 


On entering the crystal plate, this vibration is resolved into 
two vibrations in planes normal to each other. If @ (fig. 1) 
be the angle included between the major optic ellipsoidal exis 


354. FE. Wright—Measurement of Hatinction Angles. 


of the plate and the plane of the incident vibrations, the 
equations for the resultant waves are 


Qat 
| a mae 
Each of these vibrations traverses the plate with a different 


velocity and the time required by the fast wave to traverse the 
plate of thickness d will be ¢, = d.a’, while the time required 


x—=u cos 6=a cos 6 dae ind y=u sin 0=a sin 6 sin: 


Tt iL. 


by the slow wave is ¢, = d.y' where a’ and ¥' are respectively 
the refractive indices of the two waves. On emergence, 
therefore, the oe for the periodic ae will be 


x’ =a Cos 6 sin - 7: 2 (ce ) and y’=a sin 6 ne - =e t— dy?) 


On reaching the upper nicol each of these vibrations is again 
resolved further into two component vibrations again normal 
to each other, one of which, however, is annulled by total 
reflection. If @ be the angle between the principal planes of 
the nicols, then the component vibrations emerging from the 
upper nicol are « 


f=’ cos (0—¢)=a cos(6—) cosBsin = Ejsodas on sin a — da") 


n=y sin (6—¢)=asin (O@—¢)sin sin ye (t—dy')=A, sin a (t—dy’) 


and the resultant amplitude 


A=£+7=A, sin a (t—da’) + A, ae 7 (t—ay') 


LE. Wright—Measurement of Hixtinction Angles. 355 


‘The intensity I’ of the emergent wave is then proportional to 
the square of the amplitude 

T A? 

Emer ar 


The equations (3) above, moreover, ay that 


AP=A?7+A,°4+2 AA, cos d (y'—a’') 


On substituting the values of A, and A, in this equation, and 
noting that 


ike a.) 


9 
COs ae A(y —a')=1—2 sin’ d (y 


we obtain A?=a’ [cos? ¢—sin 2(6—¢) sin 26 sin? 7 d (y'—a’)] (4) 


1 2 


and finally, Tasos °p—sin 2(8—¢@) sin 26 sin*rd (y'—a') (5) 


But the velocity of hight V, period of vibration T,and wave 
length A, are so related that VT = 2 and if we consider the 
velocity unity, then we may replace T by A and the equation 
(5) reads: 

1 

; . «gE 

po = os 6—sin 2 (@—@) sin 26 sin” I d (y'—a’) 

This is the usual expression for the relative intensity of the 
emergent waves; it may, however, be br ought into more con- 
venient form for practical purposes. To save space, let sin’ 


= (y' — a’) = K, where K may have any value from 0 to + 1; 
then 
1 2 
T= 8 =? ik sin 26 sin 2(6—$) 
21 =1+ cos 26—2K sin 26 sin 2(0—¢) (a) 
=1+4+cos 246—K (cos 2¢ (1—-cos 46)—sin 2¢ sin 46) _(b) 
=1+(1—K) cos 2¢ + K cos 2(¢—26) (6) 


For a given angle @ to find the condition that the intensity 
will be zero, the equation (@) of the foregoing can be changed to 


21, =1+(1—2K sin’ 26) cos 26 + 2K sin 26 cos 26 sin 26 
—=1+K, cos 24 + K, sin 2¢ (7) 
in which 
K,=1—2K sin’ 26 and K,=2K sin 26 cos 26. 


356 FE. Wright—Measurement of Hxtinction Angles. 


If 31, = 0; then 
1+K, cos 26+K, sin 26=0 
or 1+ K, cos 26=—K, sin 2¢ 
squaring 1+2K, cos 2¢6+K,’ cos’ 26= K,” — K,? cos’ 26 


abi /( K Kee 
k 9 paar 1 + se 1 2 2 pak 
pon PK Kae aa “KCK? i 


Kt 
us, Dee omer 2 K’— 
eee by VeRO a ; 
(8) 


In order that cos 26 have a real value, the expression K,*+ 
K *—1 must be zero or positive. But, 

K *=1—4 K sin’ 264+ 4K?’ sin* 26 

K2= 4 K* sin? 26—4K? sin‘ 26. 
Accordingly, 

K?+K"—1= — 4K sin’ 26 (1—K) (9). 

The right hand of this equation is a negative quantity, and cos 
2d can vhave a real value only when K,’+K,’—1=0, and _this 
condition is fulfilled a when 


(i) I= 0 Sir onssiine = Sr iyi ch) Olde 7 d (y'—a') =na 
(2) 01K I o7ssiin ee (yi—a'\=1, 1. @, ae (y—a')=(2+1)5 


(3) sins) 20 0 eG eae 
The value for cos 2¢ then reduces to 


COs Be = = —K,=—(1—2K sin’ 26) 
For the three dierent cases the value of cos 2¢ becomes 
(1) cos 26 = — 1 1 e. 6 = @n+1), 
(2) cos 26 = — (1—2 sin’ 26) = — cos 46, i. e. 6=2x—26 
(3) cos 26 = — 1 i.e. b= (2n + 1)G 


If the nicols be not crossed, therefore, it is not possible to 
obtain absolute darkness for a given section unless 


= 2n + 1 : phere 
2 ws Be BUEN! - rs e., unless monochromatic light be 


used of such a wave length that the one wave is an odd number 
of half wave lengths ahead of the second, and in this case, 
d=7—20. If white light be employed, abnormal interference 
colors will appear because of the abnormal conditions, and at 
no point will darkness ensue. 


LE. Wright— Measurement of Kxtinction Angles. 357 


The condition that the entire light be transmitted is 


1 
1=;>! 
or (1—K) cos 26+K cos 2(¢—20)=1 
which is satisfied if both 6=0 and @=0. 

In case either ¢ or @ be given, the problem of finding the 
particular disposition of upper nicol or crystal plate for which 
the intensity of the transmitted light reduces to a minimum 
or maximum, involves the first partial differential quotients of 


the function 2I, (equation 6) after either @ or @. If ¢ be 
given, the point in question is determined by 


aK fH a 0 
. 6=20 or d6=1—20 


The second partial differential quotient shows that for the first 
value of @ the intensity is a minimum, while for 6=7—2@ the 
intensity isa maximum. ‘This relation is of importance in cer- 
tain of the methods described below. 


If @ be given and ¢ is the variable, 
o(21,) ona 
ip | . 


From this equation we find 


(1—K) sin 2¢—2 K sin 2 (6—26)=0 


K? sin’ 40 
(1—K)*+2K (1—K) cos 46 + K’ 
a complicated expression which for K=1 simplifies to 


sin’ 26= 


sin® 26=sin"40 and this equation 
is satisfied for d= 20 
d= 7 — 20 


It is of interest to plat the values given by the equation for 
different values of @ and @. 


21,=1+(1—K) cos 26 + K cos 2 (6-28). eo) 


In fig. 2, curve V, the rate of increase in intensity of 
light is given for the special case of 6 = 0, where simply the 
upper nicol is turned and the crystal plate has no effect in the 
polarization of the waves from the lower nicol. In this case 


21 = 1+ cos 26 (10) 
From the curve it is evident that the rate of increase is very 
slow at first, but rises rapidly and reaches a flexion point at 


45°, after which the intensity increases with decreasing rapid- 
ity to its maximum value at 90°. 


iS) 


8 Lf. LE. Wright—Measurement of Extinction Angles. 


dicey 


ae 
Ov O20" S040. 50 60" 0) aera 


Fie. 2.—Curves showing relative intensity of light emerging from upper 
nicol after transmission through polarizer, crystal plate and analyzer, the 
positions of the crystal plate and also the analyzer ranging from 0°-90°. 
The abscissa values refer to angular distances of the major ellipsoidal axis of 
the crystal plate and also of the plane of the analyzer. For curves I-IV, the 


nicols are considered crossed (¢= >) and the crystal plate alone to be 


9 
revolved from 0° to 90°. In curve 1, sin? a d(yi—a'!)=K=1>» in eurve if 


K=1/2; in curve 1, K=1/4; in curve 1V; K=0. ‘Curve V (shomemiae 
relative intensity of the emerging light for different positions of the analyzer 
alone ((=0, @ ranging from 0° to 90°). Curves calculated from the general 
formula 

J,=1/2 (1+(—K) cos 264K cos 2 (¢—26)). 


FE. E. Wright—Measurement of Kxtinction Angles. 359 


In ease the nicols are crossed (¢= a the rates of increase 


for different values of K are given by the reduced equation 

2], = K (1 + cos 40) = 2K sin’ 26 (11) 
which defines a curve similar in aspect to the foregoing except 
that ¢ is replaced by 2@ and the factor K tends to reduce all 
values proportionately. The curves I—IV of fig. 2 represent 
the relative intensities for values of K=1, 1/2, 1/4 and 0° 
respectively. The greatest possible intensity is thus attained 
when K=1, i. e., when the waves, aiter emerging from the 
crystal plate, are an odd number of half wave lengths apart 
(In opposite phase); the intensity is zero for all positions of 
the plate when K=0, i. e., when the distance between the two 
emergent waves is a whole number of wave lengths. 

In figs. 8-6, intensity curves are drawn showing the relative 
intensity of the emergent light for different positions of the 
erystal plate (9 usually 0°, 15’, 30’, 45’, and 1°) with the prin- 
cipal plane of the lower nicol, and for different positions of 
the upper nicol (¢ ranging from 88° to 92°). The heavy curve 
in each figure is the relative intensity curve of the crystal 
alone (nicols crossed, ¢ = 90°) and @ (ranging from —2° to + 2°) 
The narrow range of intensities only is considered, since in 
general it represents about the order of magnitude of the prob- 
able error of a single determination made in the usual manner. 

In each of the figures the unit ordinate division represents 
025 per cent of the total intensity and the unit abscissa division 
HO Or arc, 


In fig. 3, K is considered=1 or sin? 2 - d(y'—a’)=1, which 


obtains when the one wave is any odd number of half wave 
lengths ahead of the second on emergence from the plate; in 
figs. 4, 5, 6 and 7, the relative intensity curves are drawn for 
K=3/4, 1/2, 1/4 and 0 respectively. . 

It is not a difficult matter to grasp the meaning of these 
curves, as the following example will show: let it be required 
to find the percentage of light which emerges from the nico] 
in the case of a mineral plate of such thickness and birefring- 
ence that for yellow light the faster waves after emerging from 
the plate will be precisely one haif wave length ahead of the 
slow waves (K = 1, fig. 3), the direction of extinction of the 
plate to make an angle of 30’ (@=30’) with the principal plane 
of the lower nicol, and the principal plane of the upper nicol 
to include an angle of 89° 10’ with the lower nicol (6=89° 10’) 
On the 30’ curve of fig. 3 the ordinate for 89° 10’ is -104 and 
the relative intensity is therefore -104 of 1 per cent of the 
total intensity. 


360 FE. Wright—Measurement of Hxtinction Angles. 


BiGs te. 


Fic. 3.—Intensity curves for crystal plates making angles 0’, 5’, 10’, 15’, 
20', 25’, 80’, 40’, 45’, 50’ and 1° with plane of polarizer. Analyzer revolved 
about axis from 88° to 92° with lower nicol plane. 

sin? (y'—a’)=K=1 
Curves calculated from the formula 
I= 1/2(1 + cos 2 (¢ — 28) ). The 


F. E. Wright—Measurement of Extinction Angles. 361 


Hie. 4. 


oL NA 
153 Gna 
Bee th 
eee oe 
ANKE 


SOV AINE A PZ 
EUS ee OO 


O gge—gqr ats q[= q2' 


Fic. 4.—Intensity curves for crystal plates at angular distances of 0’, 15’, 
30’, 45’, and 1° from plane of polarizer, the analyzer being revolved about 


Q7xt 
(a) =K =38/4, 


axis from 88° to 92° with plane of polarizer. sin’ 
Curves calculated from the formula 

1,=1/8 [ 4+cos 2643 cos 2 (@—26) ]. 
As in fig. 3, the heavy curve indicates the relative ‘intensity of emergent 
light for different positions of the crystal plate ( ranging from 88° to 92°, 
or —2° to +2°) under crossed nicols (6= =i and K=3/4. Calculated from 


the formula 
I, = 3/8 (1+ cos 46) 


———— 


heavy curve indicates the relative light intensity under crossed nicols 
(@=5) for different positions of the crystal plate (9 ranging from 88° to 92° 


or —2° to +2°)and K=1. Calculated from the formula 2 1, = 1 + cos 48. 


362 FE. Wright—Measurement of Ketinction Angles. 


These figures 2-6 are well adapted to show graphically cer- 
tain facts which are evident from a mathematical consideration 
of the intensity formula. (1) If K = 0, which occurs when 
the one wave is any number of whole wave lengths ahead of 
the second, the erystal plate is dark and remains dark for all 
positions of revolution, as indicated by the heavy abscissa line 


Inne i), 


des 


Fic. 5.—This figure differs from the two preceding figures only in the 
value of K, whichis 1/2. The curves were calculated from the formula 
I, = 1/4 (2 + cos 26+ cos 2(@— 280) ). 
The heavy curve from the formula 
I, =1/4 (1 + cos 40). 


of fig. 7. (2) In case K = 1/4, fig. 6, the intensity comvemen 
erystal plate, coincides very closely with that for the revolving 
nicol. The extinction curves, moreover, for the crystal plate 
at different angles (@ = 15’, 30’, 45’, and 1°) with the principal 
plane of the lower nicoland for different positions of the upper 
nicol (@ ranging from 88° to 92°) are similar and lie close 
together, so that, in this particular case, methods involving the 


F. EL Wright—Measurement of Hxtinction Angles. 363 


revolution of the upper nicol for the location of zero intensity 
directions are not greatly different in their degree of accuracy 
from those in which the nicols remain crossed and the erystal 
plate is revolved. Nevertheless, even in this instance the 
former are the more sensitive methods and results attained by 
their use are correspondingly more accurate. For K=1/2, fig. 
5, the extinction curve for the crystal plate alone (nicols crossed 
and plate only revolved) no longer coincides with that for 
the upper nicol alone, but similar conclusions can be drawn as 
to the relative sensitiveness of the two methods, the one involvy- 
ing the revolution of the crystal plate (while the nicols remain 
crossed), and the second, the revolution of the upper nicol while 
the crystal plate remains stationary. The amount of light 


O gg IS Sa q2e 


Fic. 6.—Differs from fig. 5 only in K, which is 1/4. The curves are 
expressed by the formula 
I,=1/8[ 4 +3 cos 2¢ + cos 2(¢ — 29) | 
and the heavy curve by 
I, =1/8 (1 + cos 46) 


which is required to produce the sensation of light in the 
human eye is different for different persons. But for a given 
eye the limit of the actual sensation of monochromatic light is 
fixed for any particular instant and may be represented by one 
of the horizontal percentage lines of the figures. Let us assume 
that for a source of monochromatic light of definite intensity 
I, the limit for the sensation of light is ‘050 per cent of the 


364 FL. Wright—Measurement of Kxtinction Angles. 


total intensity and represented by second horizontal line above 
the base line of fig. 5. 

Then the curve for the crystal alone shows that for all points 
below that line, 1. e., between 89° 04° and 90° 56’, the crystal 
will appear absolutely dark and on a single determination an 
error of nearly +1° may bemade. If, however, the erystal 
plate remain stationary, and the upper nicol be revolved 
through small angles from its normal, crossed position (6 =88° 
to 92°), it is evident from the figure that if, for example, the 


om 
ae 


IN, 


FALLEN 

BERREBD RS See ee ca SGEEE 

0) O oe aie O ° 

66 OF 90 

Fie. 7.—In this particular case K is considered = 0 and the general 
formula reduces to 


ees (1 + cos 26) 
which is independent of 6. In other words, if the thickness of the plate be 
Qqrt 
such that sin? a (y'—a@')=0, or the emerging waves are any number of 


whole wave lengths apart, total interference takes place and the plate is 
dark under crossed nicols for every angle of revolution about its normal 
axis. 


crystal plate is 80’ distant from its position of true extinction 
and still dark under crossed nicols so far as the eye of the 
observer can detect, the differences in intensity between the 
field and crystal plate for different angles of revolution of the 
upper nicol (measured by the ordinate intercepts between the 
curve 0’ and 30’ of figure), are of such a character that at the 
point where the illumination of the field can just be observed 
(88° 43’) the intensity of illumination of the crystal is more than 
twice as great (106 per cent instead of -05 per cent), whereas 


- 


FE. Wright—Measurement of Extinction Angles. 365 


on the other side, where first indications of illumination on the 
central plate can be detected at 91° 41’, the field is lighted up 
by ‘085 per cent instead of :050 per cent of the total intensity. 
These differences of intensity are of such a character that they 
ean readily be observed, and the sensitiveness of any method 
involving the revolution of the upper nicol while the crystal 
remains stationary is in this case at least twice as great as that 
for which the nicols remain crossed and the cry stal plate alone 
is revolved. 

Similar theoretical conclusions can be drawn from figs. 3 
and 4. 

If white light be used and the upper nicol be revolved 
abnormal interference colors result. The rapid and pronounced 
change in interference colors near the position of crossed 
nicols, on a plate which is not precisely in the position of true 
extinction, is well adapted for use in the location of its ellip- 
soidal axes. 

With a given color of monochromatic light extinction angles 
should be determined on plates of such a thickness that K is 
about +1 (the two emergent waves are a whole number of half 
wave lengths apart). Thus if sodinm light be used the plates 
should show in white hght an inter ference color of about straw- 
yellow of the first order but not sensitive violet, since for this 
particular thickness the two waves are 589uu apart and the 
yellow waves are totally destroyed, with the result that the 
plate appears dark in all positions. It follows, furthermore, 
that a plate which is well adapted for determinations in one 
kind of monochromatic light may be useless for another color. 

It has been found that the insertion between the crossed 
nicols of specially cut piates and wedges of birefracting sub- 
stances, as quartz and selenite, is often well adapted to increase 
the accuracy of the measurement of the extinction angle on a 
given plate. The principle there invulved is that of the super- 
position of birefracting plates, the action of which is to pro- 
duce a resultant which differs from that of either component. 
It is possible to select a wedge or plate of such a character that 
the interference phenomena produced by it alone are extremely 
sensitive to the slight changes produced by a second crystal 
plate when it is not pr ecisely i in the position of true extinction. 

From the mathematical standpoint, the insertion of a second 
plate ‘involves a new set of conditions for the vibrating ether 
elements and the equations for the resultant are correspond- 
ingly more complex. Their derivation, however, is exactly 
counterpart to that for the intensity of a single crystal plate 
and the final result only need be given here. If the nicols be 
crossed ard @, be the angle which y,’ of the crystal plate of 


Am. JouR Scl.—FourrtH Series, Vor. XXVI, No. 154.—Octoser, 1908. 
26 


SHG 2 ae, Wright—Measurement of Hxtinction Angles. 


thickness d, includes with the principal plane of the polarizer 
and @,, the angle between y,' of the inserted plate or wedge of 
thickness d, and the polarizer plane, the relative intensity is 
given by the formula, and d,(y,'—a,') = T, and d,(y,'~a,.) 
==) then i , 


: : ener 
I, = sin 2(0,—90,) sin 26, cos 26, sin = rT, 
re ; Specs 
+ sin 2(6,—0,) cos 20, sin 26, sin p cs 
: ae a 
+ cos’ (6,—-6,) sin 20, sin 26, sin = Ce 


— sin’ (6,—6,) sin 26, sin 26, sin “7 (T,—T,) 


From this formula the relative intensity can be calculated for 


any given values of (0,,@,) and T, and T,. 
In case the crystal plate is of such a thickness that 


. 2 e ry e 
sin. T, = 1 and at the same time the inserted plate is also 
i 


Heel 
of a thickness that sin — TT = 1, this equation reduces to 
_—— = 2 
1 = sin 20 — 0) 
an expression for a curve similar in every respect to those of 


fi 


. 5 : : “ip 
g. 2, but which is zero for 6,=@, and also for 0, =— + @, and 


As ¢ ° “ TT 
reaches its maximum of 1 at 0, = = +6, It can also be shown 


that for a given increment of 0, as d@,, the ratio of the value 
of the function for (@, + d@,) to its value for @,-is greatest 
when @, is equal to 0,. If, therefore, the angle 0, be so chosen 
that the field is just illuminated, the change resulting from 
small angles of @, will be greater than for any other position 
of the inserted plate. 

In the Calderon method described below, the calcite plates 
are purposely so thick that they show the white interference 
colors of higher orders in white light, in which ease the thick- 
ness is so great that for a number of different colors through- 
out the spectrum the path difference of the emergent waves is 
a whole number of wave lengths, in other words, in the 
Calderon method it is permissible for practical purposes to con- 
sider the plate of such a thickness that for white light the 


© . TT Set) ° 
expression sin’ T, is unity, and that therefore the angle @, 


should be small in order to secure the best results, so small in 
fact that the illumination of the field is just visible. 


F. E. Wright—Measurement of Extinction Angles. 367 


In several of the other methods cited below for the exact 
location of the ellipsoidal axes of a given plate, use is made of 
quartz plates or wedges, cut normally to the principal axis, 
which rotate the planes of vibration of normally incident, plane 
polarized light. For the purposes of this paper it is not neces- 
sary to enter into the mathematical discussion and theory of 
the rotatory power of quartz, but simply to apply the known 
laws of rotatory polarization as they were first proved experl- 
mentally by Arago and Biot on this mineral. A quartz plate 
perpendicular to the principal axis rotates the plane of normally 
incident, plane polarized waves, through an angle which is pro- 
portional to the thickness of the quartz plate and also approx- 
imately proportional to the inverse square of the wave length 
used. The rotation effected by two superimposed plates is 
moreover the algebraic sum of the rotations produced by each 
separately. 

By using, therefore, a properly constructed quartz wedge, 
it is possible to counteract exactly the effect, in plane polarized 
monochromatic light, of any crystal plate in any given position 
with respect to the nicols, by rotating the new planes of vibra- 
tion, determined by the crystal plate back to the original plane 
of the nicols. 

In the intensity formula (5), 

J, = cos’ ¢ = sin 26 sin 2(0 — @) sin’ +a (y' — a) 
this rotation affects the angle @ only, and y the nicols be 
crossed, then 


1 


T, = —sin’ 26sin’° 2 (y'—a') Equation (11, page 359) 


In all measurements of extinction angles, however, @ is a 
small quantity and in place of the sine we may use the ele 
itself without sensible error; accordingly, 


== KG. (18) 


This formula, which for cue angles @ states that the light 
intensity is proportioned to the square of the angle 9, will “be 
employed later in the description of a new combination quartz 
wedge for use in determining extinction angles. 

In certain other methods, convergent polarized light is em- 
ployed and the disturbing effects of an intervening crystal plate 
observed whose optic ellipsoidal axes are not precisely parallel 
with the planes of the nicols. The intensity formulae applying 
to such conditions are similar to those for plane polarized and the 
general deductions from the latter may be considered to apply 
to the phenomena in convergent polarized light. The methods 
involving convergent polarized light, however, have several 


368 LL Ek. Wright—Measurement of Extinction Angles. 


important defects which render their general application eum- 
-bersome and unpractical. 

In the foregoing pages, the intensity formulae for light trans- 
mitted by crystalline plates under different conditions have 
been dey eloped and the attempt has been made to treat the 
subject in such a way that the results attained shall be directly 
applicable to the practical methods for determining extinction 
angles under the microscope. In the following sections, the 
different methods for accomplishing this end will be deseribed, 
with special reference to their general applicability and rela- 3 
tive accuracy, and the conclusions reached in this mathematical 
part will be used constantly as criteria of fundamental import- 
ance. 


Methods. 


Extinction angles can be measured either in plane polarized 
light or in convergent polarized light; and in plane polarized 
light the exact location of the positions of zero extinction 1s 
fixed, either by observing relative intensities of monochromatic 
hght ‘under special conditions or by means of the interference 
colors resulting from the use of white light. In all measure- 
ments of extinction angles it is imperative that careful attention 
be given to the source of light, especially if monochromatic 
light be used. ‘The source should be as intense and steady and 
uniform as possible in order that the variation in the source of 
light itselt be not mistaken for actual differences in the micro- 
scopic field. The rays of light incident on the preparation 
should, moreover, be as nearly parallel as it is possible to obtain 
them. To meet these requirements satisfactorily requires both 
time and patience, but in: order to attain the best results they 
cannot be overlooked. 

The microscope, moreover, should be in perfect adjustment, 
the optical system should be accurately centered and the cross 
hairs in the ocular should be precisely parallel with the prin- 
cipal planes of the crossed nicols. The adjustment of the 
microscope is not a difficult task to accomplish if suitable 
apparatus is at hand, and will be discussed briefly in part 2 of 
this paper. 

Assuming the microscope to be in perfect adjustment and 
the source of light satisfactory, we may use any one of the 
following direct ‘methods for measuring the extinction angle of 
a particular crystal plate: 


Parallel Polarized Light. 


(1) Phe ordinary method, which consists in turning the erys- 
tal plate under crossed nicols until the position of maximum 


LE. Wright— Measurement of Extinction Angles. 369 


darkness is attained. This method is in general use and is 
equally well adapted for white light and for monochromatic 
light. With it any degree of accuracy can be attained provided 

a sufticient number of measurements be taken to reduce the 
 bable error. In applying this method it is customary to 
note not only the positions of maximum darkness attained by 
the erystal when revolved clockwise from a position of bright 
illumination, but also when revolved counter clockwise from 
such position. This was the method used by Max Schuster* 
in his classic measurements of the extinction angles of plagio- 
clase feldspars. He determined for each cleavage flake the 
position of zero extinction eighty times for clockwise revolu- 
tions of the plate and eighty times for counter clockwise 
revolutions, and averaged the two readings. His work in this 
line remains unsurpassed, even to the present time. 

To increase the accuracy of each determination on a crystal 
plate under crossed nicols, different schemes have been devised, 
all of which depend on the disturbing influence of the plate on 
inserted plates or wedges of bir efracting substances. Hach of 
the inserted plates or wedges i is constructed in such a way that 
the interference phenomena which it presents are markedly 
influenced by the slight disturbing effects from the crystal plate 
when it is not precisely in its position of zero extinction. 

Sensitive Tint Plate-—Plates showing this interference 
color (violet of the second order) are usually made of selenite 
or quartz and are under certain conditions very sensitive to the 
slight changes which the erystal plate produces when it is not 
precisely in its position of total extinction. As a general rule, 
the eye 1s more sensitive to slight differences in color than in 
intensity, and in certain cases “the sensitive tint plate can be 
used to advantage to increase the accuracy of the ordinary 
method. Its use is most effective on and practically limited to 
colorless plates showing low interference colors of the first 
order. Its efficiency is seriously impaired in the case of deeply 
colored minerals which veil the true interference color and also 
in thick plates of strongly birefracting minerals showing high 
interference colors, even red of the first order. It can, moreover, 
only be used with white light and accordingly cannot take 
cognizance of the dispersion of the bisectrices in the mono- 
clinic and triclinic systems. This method is therefore not of 
general application and can be employed to advantage only 
under specially favorable conditions. 

Bravaist-Stobert plate-—TVhis plate is also cut to show the 
sensitive violet interference color, and consists of two such 

* Tschermak’s Min. Petr. Mitth. v, 189, 1882. 


+ Comptes Rendus, xxxii, 113, 1851 ; also Pogg. Ann. xevi, 897, 1855. 
} Zeitschr. Kryst. xxix, 22-24, 1898. 


370 LL EL Wright—Measurement of Extinction Angles. 


plates in combination instead of a single one. A single sensi- 
tive tint plate of mica or quartz is taken and cut along a line 
at 45° with the directions of extinction; the one half is then 
turned through angle of 180° and the two halves reeemented 
as indicated in the figure. By this combination plate, which is 
placed in the focal plane of the ocular, the interference color 
is made to fall in the one half and to rise an equal amount in 
the second, thus doubling the sensitiveness of the single plate. 


Hire. 8; 


This plate is intended for use only in white light, but under cer- 
tain. conditions it may serve to good advantage mm monochro- 
matic light. 3 

The Combination Wedge.*—On the principle of the Bravais- 
Stober plate, the writer has had a combination wedge prepared 
in which the interference colors range trom total darkness to 
green of the second order. This wedge was made by taking 


*This wedge was prepared with great care by Voigt & Hochgesang, 
Gottingen, Germany (cost, 48 mks.), and the writer desires to express his 
appreciation of the interest taken by the firminthe same. The compensation 
on different ends of the wedge, however, proved to be of unequal value, with 
the result that although the dark zero interference bands were precisely 
adjacent, the interference colors near the ends of the wedge did not coincide 
exactly. This defect could be eliminated by combining two quartz plates 
(45™™" long by 5™™ wide ana of such a thickness as to show interference color 
green-yellow second order, the ellipsoidal axis ¢ of the one to be parallel to 
the long direction, while in the second q is parallel), with two wedges of the 
same pitch (45™™ long by 5™™ wide and ranging in interference colors pale 
gray of the first crder to violet gray at the top of the third order, and like- 
wise the ellipsoidal axis ¢ parallel to the direction of elongation in one and q 
to the same direction in the second) ; the wedge of long direction ¢ to be com- 
bined with the plate of long direction q. In this manner the plate and wedge 
compensate in the center of the wedge and the interference colors rise to about 
blue green of the second order at both ends. 


e 


FE. EE. Wright—Measurement of Extinction Angles. 371 


an ordinary combination wedge* showing the zero interference 
band exactly in the center and green of the second order on 
each end, cutting the same longitudinally in half parallel to 
the ellipsoidal axes; the edges were then polished and the 
halves again recemented, the one half, however, having been 
rotated first thr ough 180°, so that in the resultant combination 
by wedge the phase difference of the adjacent half at any 
point of insertion is always equal and opposite. By this method 
the principle of the Bravais-Stober plate is extended to cover 
interference colors from total darkness to blue green of the 
second order, and to allow the observer to select an interference 
color which, in combination with that of the mineral plate 
examined, is most sensitive. The low gray tints of this wedge 
(particularly the dark band region on both sides of which the 
interference colors rise and thus divide the field into four 
quadrants and produce an effect similar to that of the Bertrand 
ocular) have been found specially useful with minerals showing 
interference colors from red first order to blue second order. 
This wedge is held in a brass carriage, which in turn slides 
in the wedge holder shown in fig. 10, and is viewed by the 
Ramsden ocular. 

Calderon; Calcite plate-—This plate is also placed in the 
focal plane of the ocular and consists of two calcite plates 
placed side by side and so cut that the direction of extinction 
in each plate makes an angle of about 34° on opposite sides of 
the common line of junction. The plate is so thick that the 
interference color is white of the higher orders and when used 
alone without intervening crystal plate, lights the entire field 
under crossed nicols with a dull gray tone. If a crystal plate 
whose lines of extinction do not coincide with the principal 
nicol planes be then observed, the field appears divided into 
two unequally illuminated halves and only when the extinction 
directions coincide with the nicol planes is the intensity of 
illumination in both halves equal. Calderon claims an accuracy 
of +2’ with this ocular, but for a single determination and for 
general preparations the probable error is considerably larger 

*Compare F. E. Wright, Tschermak’s Min. Petr. Mitth. xx, 233-306, 1901 ; 
also Jour. Geol., 33-35, 1902. 

+ Zeitschr. Kryst., ti, 70, 1878. —The calcite twin plates of a Calderon ocular 
from R. Fuess in Steglitz were tested by the writer and found to be inaccu- 
rately ground. The plate was 3:18™™ thick and cut at an angle of about 45° 
with optic axis. The extinction angle in each half of the plate was measured 
in convergent polarized light by means of the dark bar in the center of the 
field and found to be + 4°4° on the one half and 3°2° on the other. Extinc- 
tion angles measured with this ocular, using the junction line of the plate as 
the line of reference, would therefore be out 0°6° from this sourcealone. The 
field of the ocular is. moreover, small and unfavorably lighted because of the 


thickness of the plate and of the wide dark junction line across the center of 
the field, which in turn disturbs the exact matching of the halves of the field. 


372 FE. Wright— Measurement of Extinction Angles. 


(10’-15’). The principle on which this method is based is evi- 
dent from the intensity formula, for in case the ellipsoidal axes 
of the plate do not coincide precisely with the principal nicol 
planes, they make unequal angles with the optic ellipsoidal axes 
of the calcite (in the one half, this angle is 34° + @ and for the 
second 84° — @) and this produces at once a caeed difference 
in intensity of illumination. 
Quarter-undulation plate of H. Traube.t-—This plate con- 
sists of two adjacent quarter-undulation mica, plates so cut that 


Hire. 9) 


the optic axial plane of each includes an angle 33° with the 
common line of junction and for slight deviations of a crystal 
plate from its true position of extinction, the two halves appear 
unequally lighted, and only when the crystal i is precisely in its 
position of zero extinction do the halves show the same intensity 
of illumination. 

Twinned Selenite plate.—The use of a twinned selenite 
plate has been recommended recently by E. Sommerfeldtt for 
the accurate adjustment of the ocular crosshairs to the planes 
of the nicols. But the same twins can be made to serve admir- 
ably in the measurement of extinction angles. The extinction 
angle which the ellipsoidal axis makes in each plate with the 
twinning plane is 873°, and if the twinning line on such a plate 
be turned to the diagonal position with the crossed nicols, the 
extinction angle on ‘each side of the nicol measures 45°— B75 
= 74°, but in the opposite halves different optic ellipsoidal axes 
are adjacent the principal nicol plane. The net result of this 
arrangement is a change in intensity dependent not only on 


* Neues Jahrbuch, 1898, i, 251. 
+ Zeitschr. f. wissensch. Mikroskopie, xxiv, 24-25, 1907. 


EF. EL Wright—Measurement of Extinction Angles. 373 


Hires 10; 


Fic. 10.—Mikroskop-polymeter of Voigt and Hochgesang carrying wedge 
holder H and also device described below for holding small crystals. The 
wedge holder in turn carries a cap nicol, K, and a Ramsden ocular in the focal 
plane of which the wedge, W, isintroduced. The crystal-holding device con- 
sists of the following parts: S, the stand; C, graduated vertical circle with 
1° divisions: A, centering plate; B, ball and socket adjusting device; D, 
crystal holder; L, plano-concave lens for holding drop of liquid of same 
refractive index as crystal and held by stand, E. 

The mikroskop-polymeter is a useful instrument in many ways but for 
accurate work the mechanical workmanship on the same leaves much to be 
desired. The fine adjustment screw is practically worthless for even approxi- 
mate readings, the accurate adjustment of the different circles to the common 
optic axis is not possible, and even if once accomplished does not remain in 
adjustment: the divisions on the different verniers are inaccurate; many 
other defects have been felt by the writer and several of them remedied in 
the workshop of the Geophysical Laboratory.— A stop diaphragm M has been 
introduced into the upper tube, also an optic axial angle reflector. R (compare 
F. E. Wright, this Jour., xxii, 19-20, 1906); a holder for the combination 
wedge is shown at T, which fits on the objective supporting arm and is 
revolvable about the axis, an arrangement which has proved advantageous 
in place of revolving the microscope stage when the interference plates are 
inserted.—The fine adjustment screw P has been lengthened so that it can 
be reached from either side of the microscope. The base of the stand at N 
has been milled out to allow space for the reflector when the condenser lens 
is lowered. 


3874 FL he Wr ight—Measur ement of Extinction Angles. 


the angle but also on the different compensations of the path 
differences in the two plates, and if white light be used this 
results in a rapid change in interference color in the two 
halves if the crystal be only a small angular distance from its 
position of true extinction. 

The writer has had such a plate cut showing the sensitive 
tint and also a wedge, so that on insertion different interference 
colors, or intensities in monochromatic light, can be used for 
which the eye under certain conditions is most sensitive. These 
plates, as well as the preceding, are inserted in the focal plane 
of the objective and the junction line serves for the vertical 
crosshair. For such plates the Ramsden positive ocular has 
been found by experience to be best suited and a specially con- 
structed holder convenient. 

Artificiully twinned Quartz plate.—Still another. advan- 
tageous arrangement can be had by cutting on a polished quartz 
plate parallel to the principal axis a ver rtical edge making an 
angle of about 3°-6° with the principal axis. The quartz 
plate is then divided transversely to the polished edge and 
the polished edges cemented together, thus producing an arti- 
ficial twin whose two halves extinguish at equal and oppos- 
ite angles from the common line of junction. Such plates 
may then be ground to a thin plate showing either the sensitive 
tint or dull gray of the first order or to wedge form, thus increas- 
ing the range and usefulness of the device. 

All of the preceding plates, the Bravais-Stober, the Calderon 
and the Traube, the selenite twin plate and the quartz combina- 
tion plate wedges of the last paragraph, can be made somewhat 
more sensitive by dividing the field into quadrants instead of 
halves, after the example of Bertrand in his rotatory polarizing 
quar tz plates described below. 

Bi-nicol ocular.—In the practical application of these differ- 
ent types of plates the angle @ has been small (2—4°) and 
found to furnish good results, but in each case there is a par- 
ticular angle @ which is best adapted for the observations; the 
limit of sensitiveness of different eyes introduces, moreover, a 
variable element of such wide range that the angle @ cannot be 
calculated and fixed once for all. In order therefore to have 
control over all angles @ and thus in each instance to be in 
position to proeure the best possible conditions, the writer has 
had constructed the following ocular attachment. 

The principle of construction of the apparatus is apparent 
from the figure, and need’ not be expressed at length at this 
point. The light after passing through the lower nicol and 
the erystal plate reaches the lower reflecting prism pair of this 
ocular and passes thence through appropriate nicol prisms 
(Thompson prisms) or bir efracting plates of exactly the same 


BOL. Wright—Measurement of Extinction Angles. 375 


character, and after total reflection in the upper prism pair is 
again brought back to the common field of vision and viewed 
by the Ramsden ocular and upper nicol. The nicol prisms or 
birefracting plates fit in collars and can simultaneously be 
revolved about the axis and in opposite directions so that the 
angle @ can be made to vary from +90° to —90° in each plate 
and at any instant @ of the first plate is equal and opposite to @ 


Innes 1. 


TET 


| 
ame 

| 

| 


| 


Y 


\ 1 
te 


Fie. 11.—Bi-nicol ocular; consists of the following parts: Two pairs of 
reflecting prisms, P, and P», (ground specially for the purpose by Steeg & 
Reuter of Homburg v. d. Héhe, Germany); two tapering revolving brass 
holders, M, into which either two Thompson prisms, N, or birefracting plates 
are introduced. These conical brass carriages are revolved in opposite 
directions and through equal angles by means of the worm thread S and 
grooved wheels T, the angle of revolution being read off directly on the head 
H. The bi-nicol ocular fits in the microscope as an ordinary ocular and into 
it in turn a Ramsden ocuiar is introduced and above this the cap nicol. 


of the second plate. In the mechanical construction of this 
apparatus, special care has been taken to make the angular 
movements of both plates exactly equal and opposite. 

With this revolving bi-nicol ocular, it is thus possible to 
allow any proportion of the light incident on the crystal plate 


876 EL. Wright— Measurement of Extinction Angles. 


to pass through the upper nicols by simply revolving the same 
and at every instant to state what percentage is passing through. 
The particular angle of revolution @ for which the intensity of 
light transmitted is best snited for the maximum sensitiveness 
of the eye of the observer can be readily ascertained, and the 
actual position of extinction for any given mineral plate be 
determined by its use. By means of the bi-nicol ocular, the 
adjustment of two crossed nicol prisms ean also be tested accu- 
rately and easily. 

This ocular, although serviceable, suffers from one defect 
which it is difficult to overcome satisfactorily, namely, the 
depolarizing of the total reflecting prism pairs on light waves 
transmitted when the planes of ‘the revolving nicols are not 
parallel with the planes of the polarizer and: analyzer. Asa 
result a certain amount of false light is introduced into the 
field and tends to veil the sharp contrast of the two halves and 
thus to decrease the sensitiveness of the instrument. 

Bertrand plate—In place of birefracting plates, whieh 
introduce an entirely new set of conditions in the path ‘of heht 
waves and which complicate the expression for the relative 
intensity correspondingly, Klein* and Bertrand} have used 
the rotary power of quartz plates, cut normal to the principal 
axis, on the plane of polarization of normally incident, plane 
polarized waves. As shown above, the total effect of such 
a quartz plate in monochromatic light i is me to increase the 
angular distance @ in the intensity formula (6). This power 
of rotation of quartz varies with different wave lengths and 
with the thickness of the plate. If white light be used, inter- 
ference colors result. 

A quartz plate 7-50" thick shows the sensitive tint under 
crossed nicols and can be used to good advantage in measuring 
extinction angles, since for slight deviations of the crystal plate 
from the position of true extinction its interference color rises | 
or falls. ‘To inerease its sensitiveness, Bertrand combined two 
plates (2™" in thickness) of right-handed with two plates of 
left-handed quartz, so that each right-handed plate is adjacent 
to a left-handed p slate. This plate is inserted in the focal plane 
of the ocular and the sharp junction lines serve as crosshairs. 
The Bertrand plate can be used in monochromatic light, pro- 
vided for the particular wave length used, its angle of rotation 
is not a multiple of 7, in which case darkness ensues and the 
observed effect is nil. By revolving the upper nicol it is pos-. 
sible in white light to bring out the sensitive interference tint 
over the entire tield covered by the Bertrand plate, and in such 
a position a very slight turn of an intervening erystal from its 
position of true extinction is sufficient to disturb this equality 


* Neues Jahrbuch, 1874, p. 9. + Zeitschr. Kryst., i, 69, 1877. 


pa a 
ty met +i 


FL EL Wright— Measurement of Extinction Angles. 377 


of interference color and to divide the field into four quad- 
rants, the opposite sections of which are similarly colored, 
while adjacent sections are differently colored. 

The Bertrand plate is best adapted for use in white light, 
although it is possible to use it in monochromatic. light pro- 
vided its thickness be correct for the particular wave length 
employed. 

The quartz half shade plate of S. Nakamura.—tin a recent 
paper,* S. Nakamura discussed ifhc problem of the sensitive- 
ness of the half shade system and arrived at practically the 
same conclusions as those noted above. He suggests the 
use of a double quartz plate of -4™™ thickness instead of 
3°5™™ or 7™™ thick as in the Bertrand ocular, and by actual tests 
finds the theoretical deductions valid and the plate useful. The 
thickness of -4™™ is equivalent to an angle (90—@) of about 
867° on each side of the junction line; under certain con- 
ditions of illumination this angle is undoubtedly the best, and 
with the plate the accuracy of the measurements thereby 
attained equal to that of any of the other measuring devices. 

Bi-guartz wedge-plate.—It is possible, however, to construct 
a combination wedge of quartz plates of sucha character that 
any angle otf rotation from 0° to any other value, positive or 
negative, can be had on insertion of the wedge, thus adapting 
to wedge form the advantage of the revolving bi-nicol ocular. 
This has been accomplished by combining two plates of 
quartz cut normal to an axis and of specified thickness, the 
one of right-handed, the other of left-handed quartz, each 
with a wedge of quartz of the opposite sign of rotary polari- 
zation, as indicated in figure Bae 

The effect of this combination is to produce zero rotation in 
each half wedge where plate and wedge have the same thick- 
ness and as the w edge is inserted or drawn out from this point 
of zero rotation the angle of rotation increases proportionately 
and in a positive sense on one side of the junction line of the 
combination and in a negative sense on the opposite half. This 
combination wedge, which is introduced at the focal plane ot 
the ocular, divides the field under crossed nicols into two halves, 
the intensity of color of which at any instant is equal, pr ovided 
no intervening crystal plate is present or is rendered inactive 

* Centralblatt f. Mineralogie, 1905, 267-279. Compare also J. Macé de 
Léepinay, Jour. de Phys. (2), iv, 267, 1885;(3), ix, 585, 1900. Unfortunately this 
paper did not come to notice until after the manuscript of the present article 
had been sent to the press and the mathematical discussion by S. Nakamura, 
which considers the problem from a somewhat different standpoint, could 
not well receive the analysis and recognition which otherwise might have 
been given it in the general theoretical part. 

+ Made for the writer by Steeg & Reuter of Homburg v. d. Hohe, Ger- 


many. Cost, 100 marks. The accuracy of this wedge was tested by the 
writer and the grinding found to be exceptionally perfect. 


378 EE. Wright—Measurement of Extinction Angles. 


by the parallelism of its ellipsoidal axis with the principal 
planes of the nicols. So soon as the erystal is turned even a 
very small angle ont of this position, the intensity of illumina- 
tion of the two fields is no longer equal. By inserting or 
withdrawing the combination wedge, the most advantageous 
angle of rotation in the two fields can be procured so that 
the difference in intensity between the two halves is most 
apparent.: In effect this wedge is identical with that. of the 
bi-nicol ocular described above, is much simpler in con- 


Fie. 12. 


Fie. 12. Bi-quariz wedge-plate. Inthe plate-wedge ground for the writer 
the two quartz plates are 30™ long, 6™™ wide, and °30™™ thick. The 
wedges are 5™™ thick at the one end and ‘O™™ at the thick edge. Cement- 
ing material is Canada balsam whose refractive index is 1°54, while w for 
quartz is 1.544, a difference so slight as to render inappreciable the exceed- 
ingly slight deviation of the waves caused by the slight wedge surface of the 
wedge. This inclined surface is mounted next the Canada balsam and care 
is taken by inserting a thin glass strip at the thin end to make the upper 
and under surfaces of the completed wedge parallel. The thickness of the 
wedge is ‘9™™. At the one end the rotation is +1°1° ; at the thick end, +3°2° 
for sodium light, while at -85™™ from the thin edge the rotation is zero in 
both halves. For a wedge-plate of an angle of rotation 0° to 10° the follow- 
ing specifications are suitable: length 50"™, width of each half 6™™, total width 
of wedge 12™™.; thickness of plate, 4™™; thickness of wedge at thin end 
‘30™™ ; at thick end, ‘80™". In such a wedge the point of zero rotation is 5™™ 
from the thin end. At the thin end the rotation is +1°1°; at the thick end, 
+9°9°. In the article following this, specifications for a wedge with rotation 
of 15° at the thick end are given. In preparing the wedge it is necessary 
that the edges be ground and polished in order that the central division line 
(fig. 11) be as sharp as possible. The two halves are eventually cemented 
side by side with Canada balsam and any disturbing influence thus eliminated 
which might arise from total reflexion on the sides. 


struction, and requires no adjustment ; the one condition which 
must be fulfilled for satisfactory results is that the wedge 
be not tilted on insertion but that the optic axis remain always 
parallel with the optic axis of the microscope, otherwise ais- 
turbing birefringence phenomenaappear. The wedge carriage 
should, therefore, slide in an accurately fitting holder such as 


FE. Wright—Measurement of Extinction Angles. 379 


shown in fig. 10 above, which was constructed in the workshop 
of the Geophy sical Laboratory. 

Methods involving revolution of upper nicol—In all of the 
preceding methods the nicols have been considered crossed and 
the erystal plate revolved. The intensity formula shows, 
however, that the relative intensity is dependent not only on 
the angle 6 of the crystal plate but also on ¢, the angle between 
the principal planes of the nicols. It was shown in ‘the general 
mathematical treatment that this method is in general at least 
twice as sensitive as the method based on the revolution of the 
erystal plate under crossed nicols. The mode of application 
of this method to any particular crystal plate is obvious and 
consists simply in placing the crystal under crossed nicols in 
its position of apparent “trae extinction and then obser ving, 
either in white or monochromatic light, the changes which 
occur on revolving the upper or lower nicol through small 
angles with its normal position. In case the crystal is actually 
in its position of true extinction, the erystal and field attain 
their position of maximum darkness simultaneously and show 
the same increase in its intensity of illumination; if, however, 
the crystal be not in its position of true extinction, but a 
small + angle, as 30’ distant, then for a position of the nicol 
+2° from its normal position, the crystal plate will appear 
lighter than the field; and vice versa for the nico] —2° 
from its normal position the erystal plate will appear darker 
than the field. This method is extremely simple in manipu- 
lation and does not require special apparatus, but seems not 
to have been applied before to the measurement of extinction 
angles. Weinschenk,* in describing the adjustment of the 
nicols in the microscope, uses the interference phenomena 
which occur under these conditions, but does not appear to 
have applied conversely the principle to the practical deter- 
mination of the optic ellipsoidal axis in a given erystal plate. 

To double the sensitiveness of this method of revolving the 
upper nicol, the bi-nicol ocular attachment of fig. 11 can be 
used. By this device alone, without the upper nicol used in 
the above methods, the two halves of the field in the ocular 
preserve the same intensity of illumination at every instant, 
provided no disturbing crystal plate intervenes. If the posi- 
tion of the latter does not coincide precisely with its true 
position of zero extinction, the two halves of the field appear 
unequally illuminated and by revolving the nicols that position 
of the nicols can be found for which the effect is most pro- 
nounced for a given angle @. 

In its effect the bi-quartz wedge plate is identical with the 
revolving bi-nicol scheme, and has the advantage of requiring 


* Zeitschr. Krystall. xxiv, 581-583, 1895. 


380 FF. L. Wright—Measurement of Hatinction Angles. 


no adjustment and of not suffering from the false light of 
depolarization noted above. 

Convergent polarized light.—Two methods have been pro- 
posed which require convergent polarized light and are based 
on the change in aspect of symmetrical interference figures 
caused by the intervening crystal plate when it is not pre- 
cisely in the position of zero extinction. The idea underlying 
the methods is that the eye can detect more readily slieht 
changes in the shape of a symmetrical interference ficure 
than proportionate changes in intensity or color. Theoret- 
ically, this principle is excellent, but its practical application 
to mineral sections is less satisfactory. The first method of 
this type was proposed by Kobell in 1851, who used a plate of 
calcite normal to the optic axis as his test plate. The micro- 
scope was arranged for convergent polarized light and the erys- 
tal plate with the calcite test plate above it placed ‘on the 
microscope stage and turned until the interference figure 
appeared perfectly normal and undistorted. Practically, the 
following objections apply to this method. The optical system 
of the miscroscope requires changing each time to meet the 
new conditions ; during the observations the er ystal itself is 
lost sight of, and in the case of minute crystals or crystals with 
undulatory extinction this is a serious drawback. Moreover — 
it is tacitly assumed that in the crystal plate itself for direc- 
tions other than the normal to its surface of the crystal plate 
the planes of polarization remain parallel, which in general is 
only approximately true even for small fields which inelude 
only a small angle with the normal. 

In the Brezinat method a more complicated interference 
figure is produced by two calcite plates cut at a small angle 
with the optic axis and cemented together one above the other 
in such a way that the optic axes of the two are in the same 
plane and at equal angles with the normal. The interference 
figure from such a combination is notew orthy because of a 
dark vertical bar through the center of the field. A slight 
revolution of an intervening crystal plate displaces this bar 
noticeably, but the same objections noted in the Kobell method 
apply with equal force to this method,.with the result that 
neither method is made use of at the present time by working 
petrologists. In fact, both these methods were suggested 
before the petrographic microscope had been introduced. 

The relative sensitiveness of the different methods.—The 
term position of extinction means practically that position of a 
birefracting plate for which heht waves are transmitted with- 
out changing their plane of polarization and for which no light 


* Pogg. Ann., xcv, 320, 1859. 
+ Described in Schrauf’s Lehrb. d. Phys. Min. ii, 219-220, 1868. 


\ 


F.. E. Wright—Measurement of Hatinction Angles. 381 


passes the upper nicol, i. e., the field is just as dark as though 
no crystal plate were there. A revolution of the plate thr ough 

a very small angle from its position of true extinction allows 
an equally small percentage of the total amount of incident 
light through the upper nicol and the field is very dimly illu- 
minated. For agiven angle of revolution, the actual amount of 
transmitted light can be increased only by i increasing the orig- 
inal souree of light. Since, however, it is not possible to 
increase the intensity of such a source indefinitely, and the 
human eye is sensitive only to a certain limit, the position of 
actual extinction can only be determined within a definite degree 
of exactness. By means of the above devices, however, certain 
phenomena are introduced which increase the accuracy of such 
a determination, even though the field of original illumination 
remains the same. That method or device is obviously the 
best for which the probable error of a single determination 
under the same conditions is the least. 

In comparing the relative accuracy of the methods described 
above it will facilitate the presentation to assume definite 
conditions and then by means of the theoretical intensity 
curves (figs. 2-7) to test the results attainable by the different 
methods under the most favorable conditions. 

Let it be assumed that under the conditicns of experiment 
the eye of the observer is of such sensitiveness that he is able 
to detect ‘05 of one per cent of the total ight intensity; in 
other words, he can just detect the difference between the 
dark field of the microrcope under crossed nicols and a erystal . 
section turned at such an angle as to allow -05 of one per cent 
of the total intensity through the upper nicol. For all posi- 
tions of the crystal, then, for which the intensity of the emerg- 
ent light is less than -05 per cent, the crystal will appear abso- 
lutely dark. The heavy curves in figs. 8-7 indicate the relative 
intensity of illumination of a crystal under crossed nicols for all 
positions of its major ellipsoidal axis from 88° to 92° or —2° to 
+2° with the plane of the polarizer; in fig. 3 there is an interval 
of 38’ at least on each side ot the true extinction position for 
which the eye is unable to detect any interference illumination. 
The possible error on a single determination under the most 
favorable conditions is in this case at least + 38’ while for fig. 
meiner 44 aor doy > (KG) Ey do tor fic. 6) se 1° 17" ; 
while for the K = 0 the erystal is dark for all positions. In 
any crystal, therefore, the conditions are most favorable when 
the plate is of such thickness that K = 1 or the emergent 
waves are half a wave length apart (in opposite phase). Con- 
versely, having given a crystal plate, not all wave lengths are 
best adapted for extinction-angle measurements. If yellow 


Am. Jour. Sci1.—FourtsH Series, VoL. XXVI, No. 154.~OctTosrEr, 1908. 
Ot 


382 FL Ek. Wright—Measurement of Extinction Angles. 


sodium light be used, a plate showing the sensitive violet inter- 
ference tint is worthless since for that tint the path difference 
is 572 wp, nearly a whole wave length of Na hight (589), and 
for this difference K = 0 and fig. 7 applies. “Lf sodium hight 
be used, then plates should be. chosen for which the phase 


ain 


difference of the two emer ging waves is 


, br oht yel- 


low of the first order or pure yellow of rhe oe order or 
ereen yellow of the third order, ete. This is an important 
consideration and applies to all methods involving the inten- 
sity equations. 

The visible spectrum includes wave lengths ranging from 
about 400up, and T0O0upm, the interference color in white heht 
ranges from about red of the first order to blue of the second 
order ; in short, the sensitive interference tint region of the 
Newton color scale as determined by G. Quincke.* For this 
interval the distance between the emergent waves is not far 
from a whole wave length for the major part of the visible 
spectrum ; in other words, the phase difference is such that K 
is a small fraction not greatly different from zero and the 
intensity curves for practically all wave lengths will be cov- 
ered by 5-7. These are, however, the least favorable for 
showing difference in intensity and such plates are, therefore, 
the least suitable for the measurement of extinction angles by 
methods based on intensity differences. On the other hand, 
plates showing interference colors gray to yellow of the first 
order are best suited for such measurements. If the methods 
involving interference tints be used, however, these objections 
do not hold with equal force. Experience has shown’ that in 
ease the mineral plate does show red or blue interference tints 
of the first and second orders the best determinations ean be 
made either by the method of revolving the upper nicol or by 
the bi-quartz wedge plate, and the true position fixed by noting 
the absence of abnormal interference colors on revolving the 
nicol very shghtly or inserting the wedge. 

After this digression on the most suitable sections for the 
measurement of extinction angles, fig. 3 may again be con- 
sidered and the relative accuracy of the different methods 
under the same conditions of experiment deduced. 

The heavy curve indicates that for the assumed limit of 
sensitiveness ‘05 per cent of the total intensity, an error of at 
least +38’ on a single determination is possible by revolving 
the crystal plate alone under crossed nicols. On the other 
hand, if the crystal plate remains stationary and the upper 
nicol alone is revolved, the other intensity curves of fig. 3 are 
valid, each curve indicating the intensity of illumination of 


-Poge, vA nil) Cxaxd x muni loo on 


Ste ee 
Balti’ 


F. E. Wright— Measurement of Extinction Angles. 383 


the crystal plate for a specified angular distance from its posi- 
tion of true extinction during the revolution of the upper nicol 
from 88° to 92°. These curves indicate that the probable 
error with this method is less than half as great as in the 
preceding method, for if the crystal be only +15’ distant from 
its position of true extinction, differences in intensity can even 
then be detected on revolving the upper nicol. 

The changes in intensity of illumination of the microscopic 
field on revolution of the analyzer are indicated by the 0’ 
eurve, while for the crystal plate the 15’ curve is applicable. 
At 88° 43’ (fig. 3) the field is just beginning to show detect- 
able ieneaiindin (05 per cent of total intensity), while for 
the same angle the crystal is illuminated with 0-97 per cent 
of the total intensity, nearly twice as great and easily notice- 
able. In this position the erystal plate appears, therefore, 
decidedly lighter than the field. On the other side of 90° the 
crystal plate passes its limit of light sensibility under the 
assumed conditions at 91° 42’, while for the same angle the 
microscopic field is illuminated by ‘97 per cent of the total 
intensity ; in this case the field is appreciably brighter than 
the crystal and the difference can be readily detected by the 
eye. 

li white light be used, these differences are accentuated by 
the abnormal interference colors which appear in the er ystal 
plate when it is not precisely in the position of true extinction. 
This method of revolvmg the upper nicol has the advantage, 
furthermore, of not being dependent on the accuracy with 
which the nicols are cross sed, since all data are referred at once 
to the plane of the analyzer. It is not, however, so advanta- 
geous in very weakly birefracting or deeply colored mineral 
plates. Dee. 

The sensitiveness of the latter method can, moreover, be 
doubled by devices which allow the phenomena on both sides 
of the 90° position to be observed simultaneously. This is the 
end striven for in the ocular plate, the Bravais-Stéber plate, 
the Calderon plate, the Traube plate, and accomplished most 
effectively by the new circularly polarizing bi-quartz wedge 
and also by the bi-nico] ocular, though less satisfactorily. In 
each of these last two devices the ‘plane of polarization of 
the incident waves is turned through equal angles on both 
sides of the junction line of the two parts, so that the field 
appears equally hghted throughout, while if the crystal plate 
be not in its position of true extinction, it will appear lighter 
than the field in the one half and darker in the second. Sinee, 
however, there is an angle best suited under the given condi- 
tions to show these differences most clearly, it follows that the 
best results can be had with a plate or apparatus in which the 


884 FE Wright—Measurement of Extinction Angles. 


angle @ can be varied at wili. This is true of both the cireu- 
larly polarizing wedge plate and the bi-nicol ocular, and by 
their use the probable error of the extinction position of any 
erystal plate is at least one-fourth that of a determination 
after the usual method by revolving the crystal plate under 
crossed nicols. Experience has shown that with favorable 
sections, extinction angles can be determined by the use of the 
bi-qnar tz wedge with a probable error of less than +10’ on a 
single trial. 

Still another method for obtaining the most favorable con- 
ditions of experiment with a given plate is that suggested on 
page 374 with the artificially twinned quartz Hee The two 
halves of this wedge extinguish at a small angle (as 3°) on oppo- 
site sides of the line of junction, and by inserting the wedge 
that particular interference color, or phase difference if mono- 
chromatie light be employed, can be produced for which the 
given angle of revolution (8°) is the best. This wedge, how- 
ever, is less favorable than the circularly polarizing bi-quartz 
wedge, since its twinning line must be inserted precisely 
parallel with the plane of the polarizer, while with the cireu- 
larly polarizing bi-quartz wedge the rotation of the planes of 
polarization of transmitted waves is entirely independent of 
the line of junction of the adjacent halves. 

In the preceding pages, special emphasis has been placed on 
those methods for measuring extinction angles which are of 
general application and which are based on intensity differ- 
ences. The other methods, which are of limited application, 
and can be used only in white hght on favorable sections, 
depend on differences in interference colors produced by slight 
deviations of the crystal plate from its position of true extine- 
tion. Although these methods are serviceable in many 
instances, their application and the results obtained thereby 
are so dependent on the conditions of experiment that they are 
difficult to treat satisfactorily ina general way. Experience 
has shown that they are not more sensitive than the other 
methods and usually much less so. This is true both of the 
selenite sensitive tint plate and of all combinations of the same. 

Experimental Tests.—To test the different methods under 
different conditions, different mineral plates were chosen and 
the position of true extinction on each determined by the dif- 
ferent methods under precisely the same conditions of illumin- 
ation with white hght.—On an anhydrite plate showing white 
interference tints of the higher orders the possible error of a 
single determination by revolving the crystal plate under 
crossed nicols was found to be about 1-1°; ; by revolving the 
upper nicol alone, ‘4°; by inserting the quartz wedge, about 
O-1°.; by, using (tte Calderon ocular, about °5°; by means of 


red 


F. EB. Wright—Measurement of Extinction Angles. 385 


the Bertrand ocular, about 0°1°; with such a plate the sensi- 
tive tint plate is of no value since the interference color of the 
anhydrite plate itself is so high that the violet of the inserted 
plate has no effect and the differences in intensity which occur, 

do so in astrongly lighted field and are not easily discernible— 
Similar measurements were made on an apatite plate parallel 
to 1010 and showing the interference tint, red of the first 
order. The possible error of a single determination of the 
position of true extinction on turning the crystal plate alone 
under crossed nicols was found to be +*9°; on revolving upper 
nicol about -2°, accurate because of abnormal interference 
colors which appear when the plate is distant only a slight 
distance from its correct extinction position; on inserting the 
bi-quartz wedge plate 0°2° to 0°3°; with the Calderon ocular, 

about 0°3°; with the Bertrand ocular, about 0°3°; the sensi- 
tive tint plate is again of no value since the interference color 
changes com paratively slowly as crystal is revolved.—A sec- 
tion of nephelite parallel to 1010 and showing the interference 
color, yellow first order, gave the following results: On 
revolving the crystal plate alone, possible error -4°; on rotat- 
ing upper nicol, less than 0-1° ; with bi- -quartz wedge less than 


0-1°; Calderon: ocular about 0°2°; Bertrand ocular less than 


071°; sensitive violet plate still of very little value as a 


med only slight changes in color for large angles of 
revolution of plate. On a plate of colorless gehlenite of very 
low interference color, dull gray, first order, the sensitive tint 
plate proved as satisfactory as any other and more so than the 
method of turning the crystal plate under crossed nicols or of 
revolving the upper nicol or the Calderon ocular. The Ber- 
trand ocular and the bi-quartz wedge plate proved about as 
favorable, the probable error being slightly less than 0°5°.—A 
plate of strongly pleochroic tourmaline was also used and the 
following results obtained: Probable error of determination 
on rev olving crystal plate alone, about 16°; the method of 
revolving upper nicol is of little value because of deep natural 
color of mineral and consequent ey to match fields ; 
with the bi-quartz wedge plate 0°3°; Calderon ocular, about 
0-4°; Bertrand ocular, about 0°5°. The sensitive tint plate is 
useless because of strong natural color of mineral which veils 
the true interference colors. 

The results of these tests show that the theoretical deduc- 
tions from the general equations are in general valid, but that 
in certain instances other factors, as natural color and very 
low birefringence, become dominant and tend to render some 
of the methods less sensitive and to favor the use of other, in 
general less suitable methods. The bi-quartz wedge plate, 
however, seems to apply in all cases with equally favorable . 


386 LL. Wright—Measurement of Hxtinction Angles. 


results and to equal in sensitiveness any of the methods, whether 
of local or of general application. 


2, The Adjustment of the Petrographic Microscope with Special 
Reference to the Measurement of Hxtinction Angles. 


A petrographic microscope in perfect adjustment should satisfy 
the following requirements: (1) Its optical system should be 
accurately centered ; (2) the axes of revolution of all revolvable 
parts, whether stage or ocular, should coincide with the optic 
axis of the micr oscope ; (3) the principal ae of the nicols 
when crossed should be precisely 90° apart; (4) the crosshairs 
of the ocular should be parallel with the principal planes of 
the nicols. Of the four conditions, the first two can be 
accomplished without difficulty, and with the adjustment 
screws fitted on every petrographic microscope. The last two, 
however, require special appliances for accurate adjustment, 
and Shout these can be effected only with difficulty. 

The test usually applied in ascertaining the correct position | 
for crossed nicols is that of the Bertrand ocular. A cap nicol 
is used over the ocular and turned until the field of the Ber- 
trand ocular shows uniform intensity of illumination through- 
out. This can be accomptished readily and with an error of 
less than +15’ if strong illumination be used. The cap nicol 
is then revolved. thr ongh an angle of 90°, the lower nicol 
removed in its carriage, ‘the upper “nicol inserted and tested by 
the cap nicol in its new position and adjusted: until it is 
actually crossed. The Bertrand ocular, however, furnishes 
only one angle of rotation for the emerging waves, and allows 
of no variability in this angle to meet “different conditions in 
the best way possible. This can be accomplished, however, 
by use of the circularly pone bi-quartz wedge plate 
described above or the bi-nicol ocular. With the bi-quartz wedge 
plate the cap nicol is unnecessary and crossing of the micro- 

scope nicols can be tested directly. For this purpose, parallel 
hght should be used and the entire lens system, both conden- 
sor lenses, objective and ocular, removed from the microscope ; 
parallel incident rays are then allowed to fall on the reflector 
of the microscope (either sun rays or strong white light or the 
rays from a Nernst filament or are light emerging at the focal 
point of a large lens). The parallelism of the incident rays 18 
necessary and an important factor, since with the thick quartz 
plates a slight deviation from nor mally incident and parallel 
hght produces disturbing inter ference phenomena. The 
bi. -quartz wedge-plate in its metal casing may then be placed on 
the microscope stage and with it the accuracy of the crossing of 
the nicols tested directly, just as the position of zero extinc- 
tion of a mineral plate is tested. The error of such a deter- 
mination should be considerably less than 10’ of are. 


F. E. Wright—Measurement of Extinction Angles. 387 


-The final step in the adjustment is the alignment of the 
crosshairs of the ocular with the principal planes of the nicols. 
Many methods have been suggested for this purpose which 
may be used to advantage. A mineral showing good cleavage 
or lines of growth and parallel extinction (fakes of anhydrite 
or crystallites of quartz) serve well for the purpose. ‘These are 
first placed in the position of zero extinction (determined 
accurately by means of bi-quartz wedge plate), and the cross- 
hairs of the ocular brought to par allelism with the er ystal edge 
or cleavage line. The chief difficulty in this method lies in 
the fact that it is exceedingly difficult to obtain suitable ~ 
material. 

E. Sommerfeldt* has recently suggested the use of a twinned 
plate of selenite of sensitive tint. The plate is turned until 
under crossed nicols the interference colors in the two halves 
are of precisely the same tint, in which position oS twinning 
line parallels the principal planes of the nicols. This method 
is sensitive and satisfactory, especially if, instead of a plate, a 
wedge of the material be used, with which the interference 
eolor can be changed until that particular tint, for which the 
observer’s eye is most sensitive, covers the tield. In this con- 
nection care should be taken to select a selenite plate in which 
the twinning line is perfectly straight. In the selenite plate, 
however, the angle which the adjacent Ba. axis in each 
half makes with the twinning line is 374°, a very large 
angle and not so well adapted to show slight deviations from 
the true position as a twin of smaller symmetrical angle. In 
this connection experiments with plagioclase lamellze were 
tried but abandoned, since it was found by experience to be 
exceedingly difficult to procure suitable material for the pur- 
pose ; a simpler method can, however, be used, which accom- 
plishes the same purpose more readily. On a thin plate of 
quartz, cut parallel to the principal axis, an edge surface, 
making an angle of 4°—6° with the principal axis, is first 
ground and polished. The plate is then cut in half at right 
angles with the polished edge surface and the two halves placed 
with their polished edges side by side and cemented with can- 
ada balsam, thus producing an artificial twin of any angle which 
may be selected as most suitable and best adapted for fixing 
the crosshair in the ocular. The twin is finally ground thin 
and polished either to the sensitive tint or a pale gray of the 
first order or in wedge form.+ Like the selenite twin plate, it 
is placed on the stage of the microscope and revolved under 

* Zeitschr. fiir wissenschaftliche Mikroskopie, xxiv, 24-25, 1907. 

+ Such a plate and also wedge were prepared for the writer by Voigt & 
Hochgesang of Gdéttingen, and have proved satisfactory in every respect. 
The twinned selenite plate of sensitive tint cost 5 marks; the wedge (I-III 
order interference colors), 21 marks. 


388 L.A. Wright—Measurement of Hautinction Angles. 


crossed nicols until its halves show equal intensity of illnmi- 
nation, in which position the line of junction fixes the direc- 
tion for one of the crosshairs of the ocular. 

By use of the bi-quartz wedge plate and the artificial quartz 
twin plate or wedge, the adjustment of the nicols and also of 
the crosshairs in the ocular is a matter of only a few moments, 
and the method followed is theoretically and practically more 
accurate than the other methods for adjustment which have 
been suggested. 


3. A Device for Holding Small Crystals for the Purpose of 
Measuring Extinction Angles in Zones ; also for Measuring 
the Optic Axial Angle of such Fragments directly. 


In measuring the extinction angles of certaim minute artificial 
pyroxene and other crystals in the prism zone, the writer has_ 
had occasion to use the following holding device or fin mei 
which has proved both convenient and practical.* (Fig. 16 on 
stage of microscope.) 

As indicated in the figure, it consists of two parts, a holding 
or clamp device for the ‘crystal itself, and a universal ball and 
socket joint and centering plate for adjusting and centering 
the crystal, and a vertical circle for reading any specified angle 
of revolution of the crystal. A small crystal (1-2™" in length) 
thus held and adjusted is immersed in a drop of liquid of the 
same refractive index and thus the disturbing phenomena of 
refraction and total reflection eliminated. The liquid drop is 
contained in the concave side of a planoconcave lens of 6™™ 
diameter (ground for the purpose by the Scientific Shop ot 
Chicago), which in turn is held by an adjustable and support- 
ing arm. 

Tn work with artificial preparations particularly it is often 
desirable to measure extinction angles on certain minute 
faces, or optical axial angles, of small fragments too minute for 
the optic axial angle apparatus and not suitable for measure- 
ment by one of the microscopic methods,t and this device has 
been made to fill that want. After adjustment and immersion 
in a liquid of refractive index 8 the optic axial angle can be 
read off directly on the vertical circle of this apparatus. 


Summary. 


The measurement of extinction angles of minerals in the 
thin section is one of the most common methods of petro- 
graphic microscopic practice, and at the same time one of 

* This apparatus was made in the workshop of the Geophysical Labora- 


‘tory at the instigation of the writer, and can be constructed by any good 


mechanic. 
+ Compare F. E. Wright, Measurement of the Optic Axial Angle of Min- 
erals in the Thin Section, this Journal (4), xxiv, 317-369, 1907. 


FE. Wright —Measurement of Extinction Angles. 389 


the least satisfactory when accurate results are desired. It is 
an exceedingly easy matter to measure, with one trial only and 
on favorable sections, extinction angles with a probable error 
of +1° to 2°, but to do so within 1° is a very different mat- 
fer. In-.the “foregoing pages the problem is first discussed 
theoretically, and the mathematical equations covering the 
different methods applied to extinction angle measurements 
derived and discussed briefly. The methods for this purpose 
may be grouped into two classes,—those of general application 
and those of limited applicability The first class may again 
be subdivided into two classes ; either (1) the erystal is revolved 
between crossed nicols about its position of true extinction, or 
(2) the crystal remains stationary, and the accuracy of its position 
of true extinction tested by revolving the upper nicol or by 
inserting one of several different optical devices to increase the 
sensitiveness of the test under the prescribed conditions of illu- 
mination. These devices include the Calderon ocular, the 
Bertrand ocular, the Bravais-Stober plate, the Traube plate, 
also twinned plates and wedges of selenite, artificially twinned 
plates and wedges of quartz, the circularly "polarizing bi-quartz 
wedge plate and the bi-nicol ocular, all of which are described 
briefly above. Of these devices the last two are the most uni- 
versal and can be so used under any given conditions of illu- 
mination ‘that the phenomena observed are the most sensitive 
possible to attain by devices of this type. 

On comparing the relative sensitiveness of the different 
methods under the same conditions, it is found that the method 
of testing the position of true extinction for the crystal by rev- 
olution of the upper nicol is, on colorless mineral-plates, at 
least twice as sensitive as that of simply turning the crystal to its 
position of apparent maximum darkness under crossed nicols.. 
Under the same conditions the methods requiring the use of 
one of the several plates or wedges mentioned above are at 
least four times as sensitive as the ordinary method. With the 
exception of the last two devices, however, these different 
plates'do not furnish equally sensitive results for the different 
conditions of illumination which may arise. In accurate work 
adjustable sensibility is of prime importance, particularly if a 
given device is to be of general application. These require- 
ments are best filled by the bi-quartz wedge plate, by means of 
which the angle of rotation can be varied from 0° to any desired 
anele.- Vhe two halves of this wedge rotate in opposite direc- 
tions, and on insertion that angle of rotation can be secured for 
which the contrast in the intensity of the halves of the field is 
most striking for a slight deviation of the crystal from its true 
position of extinction. 


390 LE. Wright—Measurement of Hatinction Angles. 


An application of the bi-quartz wedge plate, together with 
an artificially twinned quartz-plate or wedge, to the accurate 
adjustment of the petrographic microscope is considered in 
outline in the second part above, and a method of procedure 
for accomplishing the same indicated. 

In part 8 a simple device for holding and rotating small 
erystals for the purpose of determining extinction angles or for 
measuring optic angles directly, is described briefly, such an 
apparatus having been found peculiarly useful in work with 
artificial crystals. 


Geophysical Laboratory, 
Carnegie Institution of Washington, 
Washington,’ D. C., June, 1908. 


FE. Wright—Bi-quartz Wedge Plate. 391 


Art. XLI.—The Bi-quarte Wedge Plate Applied to Polar- 
imeters and Saccharimeters ; by Prep. EuGENE WRricur. * 


In the preceding paper on the measurement of the extinction 
angles of mineral plates in the thin section, the general theory 
of the relative intensity of illumination of the field for different 
positions of the nicols and also of the crystal section is devel- 
oped. The different methods for crossing the nicols accurately 
and also for determining the position of total extinction for a 
erystal section are considered with respect to their sensitiveness, 
and the conclusion reached that the best results are obtained 
by dividing the field into parts in which the planes of polariza- 
tion are inclined at equal but small angles (90-¢ of the general 
formula) to the line of division between them (half shade 
system).+ For given conditions of illumination and sensitive- 
ness of the observer’s eye, there is always a certain angle (90-¢) 
for which the phenomena observed are most sensitive to slight 
movements from the position of true extinction. To reach the 
maximum efficiency of the half shade device, this angle (90-¢) 
should therefore be adjustable within the limits prescribed by 
these conditions. 

The conditions for maximum sensitiveness have been worked 
out for polarimetric purposes with sufficient care and accuracy 
by a number of investigators, { and several instruments have 
been designed in which high precision is possible, provided only 
that light of a certain (fel and intensity is available and 
that the substance under investigation (sugar, for example) 
permits just the right quantity of “this light to pass through it 
to fall within the rather narrow limits in which the observer’s 
eye is most sensitive. In practice, these conditions have proved 
somewhat exacting, and considerably greater elasticity in the 
adjustment of the optical system of the instrument with a view 
to service under a greater variety of experimental conditions, 
without loss of accuracy, is desired. Mr. Frederick Bates$ of 
the Burean of Standards has recently successfully designed an 
instrument in which this feature has received attention. His 
polariscope follows the Lippich system with the addition of 
sets of gear wheels for revolving the large polarizer and analyzer 
simultaneously in such a way that the angle of revolution of the 
polarizer at every instant is twice that of the analyzer. He 
has also demonstrated that the small angle (8) between the 

* The author is indebted to Dr. Arthur L. Day of this laboratory for several 
important suggestions in the preparation of this paper. 

+S. Nakamura, Centr. f. Min., 1905, p. 267-279; P. G. Nutting, Bulletin, 
Bureau of Standards, lii, 249, 1906. 


t See Winkelmann, Handbuch der Physik (2), vol. vi, pp. 1362-3. 
§ Bulletin of the Bureau of Standards, iv, 461, 1907. 


392 F. E. Wright—Bi-quarte Wedge Plate. 


normal to the principal plane of the analyzer and the bisector 
of the angle between the nicols of the Lippich polarizer can be 
readily compensated by a slight shift of the zero in the quartz 
compensator scale. This apparatus is easily superior to the 
ordinary quartz compensating polarimeter and is of more 
general application, but it is mechanically difficult and expen- 
sive to build and its adjustments are rather sensitive to wear 
and tear. It therefore occurred to the writer that the bi-quartz 
wedge plate described in the foregoing paper might serve the 
same purpose much more simply and therefore be of some prac- 
tical utility in polarimetric and saccharimetric measurements. 
By means of this wedge the plane of vibration of waves from 
the analyzer is made to rotate from 0° to any specitied angle 
by varying the thickness of the wedge employed, the rotation 
of the one half being right-handed and the other left-handed. 
Since the problem of saccharimetry from the practical 
standpoint reduces to the determination of the exact angle of 
rotation of the plane of polarized light after its passage through 
the sugar solution, or, in brief, to the accurate setting of the 
analyzer or the compensating system with the analyzer, it is 
apparent that the bi-quartz wedge plate is directly applicable. 
The mode of application is the same whether a monochro- 
matic or a white light source is used. If monochromatic light is 
employed a feasible arrangement of the apparatus is shown in 
diagram in fig. 1. The monochromatic light, properly restricted 
in wave length and as intense as possible, is polarized hy the 
nicol prism P. On passing through the solution T its plane of 
Syl is rotated and the angle of its rotation is determined 
by revolving the analyzer (fitted with an accurately divided 
degree circle C) until darkness ensues. The exact position of 
extinction is then found by inserting the bi-quartz wedge, 
which offers opportunity for a finer adjustment, and ascertain - 
ing that the intensity of illumination of both halves of the 
wedge is precisely equal for all positions of the wedge plate.* 
* The wedge plate should be mounted in a metal frame arranged to slide 
like the quartz compensator in accurate grooves. The quartz wedge plate 
vsed in the examination of extinction angles in crystals is 30™™ long, 
12™™ wide, and is made up of wedges 0°3™™ thick at one end and 0°d™™ at 
the other, which are underlain by two quartz plates each *30™™ thick. The 
rotary angle range in each half is from —1°1° to +5°2°. 
For general polarimetric work, in view of the limited sensitiveness of the 
eye and the difficulty in obtaining homogeneous illumination of sufficient 


a 
intensity, itis desirable that the angle 5 should be capable of being increased 


to 15°. Toaccomplish this in a single wedge it would be best to make it 
50™™ Jong, 10 or 12™™ wide with the thin end of each wedge 35™™ and the 
thick end 1:10™™ in thickness, combined with quartz plates 0:4™™ thick. 
This gives a pitch to the wedge of 1:5: 100 0r8°. The point of zero deflection 
or the position of the black band will fall 3°3™™" from the thin end and the 
deflection on the thick end will be + 15° for sodium light. The total thick-’ 
ness of the wedge plate is 1°5™™, Canada balsam should be used for the 
cementing material and care must be taken to have the wedge surfaces adja- 
cent to the Canada balsam and also the two surfaces of the complete wedge 
plate parallel. 


LIE. Wright—Bi-quartz Wedge Plate. 393 


Moreover, if the wedge is inserted horizontally and at such a 
point that its effect on the plane of polarization of transmitted 
light is precisely zero, a straight, black, vertical band appears 
in each half of the field similar to the bands in the Babinet 
compensator (fig. 2). Dy means of this band, the true position 


jebeGen lye 


Fic. 1. Proposed arrangement of parts in polarimeter, using bi-quartz 
wedge plate as sensitive device. P, polarizer: T, sugar solution tube; W, 
bi-quartz wedge; C, degree circle of analyzer; O, Ramsden ocular; A, 
analyzer. Although the bi-quartz plate wedge may or may not be attached 
to the revolving circle mechanism, it seems preferable that its carriage 
should remain in one plane. The ocular O may be used either in front or 
back of the analyzer A, and may be a single acromatic lens in place of the 
positive ocular. Observations can also be made without the aid of the ocular 
and thus an increase of light intensity gained. 


of the analyzer can be found with great accuracy, for the set- 
ting is thus made to depend upon the exact alignment of two 
black bands and the photometric principle of comparing two 
dimly lighted fields is for the most part eliminated. 

Another advantage of this system lies in the fact that the 
boundary lines between the halves of the wedge can be made 
of knife-edge sharpness without the disturbing division line in 
the center of the field produced by the total reflection and con- 


394 LE Wright—Br-quartz Wedge Plate. 


sequent depolarization of light waves on the edge of the small 
prism of the Lippich system. The edges of the two halves of 
the bi-quartz plate are first polished and then cemented with 
Canada balsam, which has practically the same refractive index 
(1:°540 compar ed with 1: 544), so that no appreciable total reflee- 
tion with the accompanying depolarization oceurs. This is the 
same result which was successfully attained by Brace,* who 


lie, 2. 


expended an extraordinary amount of care and ingenuity in an 
effort to free the field from this disturbing dividing line; but 
his instrument is not of such mechanical construction as to lend 
itself readily to ordinary laboratory use. 

Still another favorable feature of the wedge plate scheme 
for adjusting the sensibility of a polarimeter is “the position of 
the accumulator or magnifying lens of short focal length, which 
is necessarily of greater light intensity than the “telescopic 


ocular usually used to view the polarizing system. 


iG 3}. 


O 


Fie. 3. Proposed arrangement of parts in quartz compensating polariscope 
using bi-quartz plate wedge as sensitive device. P, polarizer: TT, sugar 
solution tube; Q, quartz compensating system; W, bi-quartz wedge plate ; 
O, ocular; A, analyzer. As in fig. 1, the ocular O may be used either in 
front of or back of the analyzer ; a single achromatic lens may be substituted 
for the Ramsden ocular, or the magnifying lenses may be done away with 
altogether. 


If a quartz compensating system be used and a white light 
source, the arrangement outlined in fig. 8 might prove advan- 
tageous. The quartz compensating system has been adopted on 


7D) bebrace. hil, Mac.(6) ave ole Oa, 


FTE Wright—Bi-quarte Wedge Plate. 395 


most commercial saccharimeters in order that white hght may be 
used, taking advantage of the fact that the rotatory dispersion 
of sugar solutions is approximately that of quartz. According 
to the scheme of fig. 3, plane polarized white light emerges 
from the polarizer P, passes through the sugar solution T, the 
different wave lengths being rotated through different angles 
and thence through the quartz compensating system Q, where 
they are again united and reduced to a common plane of 
vibration, —that of the original polarizer. The quartz com- 
pensating system is inserted until the field when observed 
through the analyzer appears totally dark. As in the preced- 
ing case, this condition is,verified with the greatest sensitive- 
ness by inserting a bi- -quartz plate wedge Ww. 

Up to this point, the advantages offered by the bi-quartz 
plate wedge are mainly those of simplicity, both in construc- 
tion and in manipulation, and of greatly decreased cost, without 
any corresponding sacrifice of accuracy or sensitiveness. Its 
sensitiveness is adjustable within any limits likely to arise in 
usual polarimetric work ; it is equally adaptable to the mono- 
chromatic and to the quartz compensating systems; it is 
possible with it to do away in considerable part with the photo- 
metric principle by the use of Landolt’s bands; and finally, 
the line of division between the hemispheres is so narrow as to 
be practically invisible as an independent line. 

Furthermore, in so far as it avoids the small prism of the 
Lippich polarizing system, it also avoids an error which is 
inherent in this ‘system, and incidentally also in the Bates 

system, due to the loss of light in one half of the field in passing 
into and out of this superposed prism.* In his analysis of the 
problem, Bates has shown that the small angle 6 between the 
normal to the principal plane of the analyzer and the bisector 
of the angle, between nicols of the Lippich polarizer, can be 
allowed for by a slight shift of the zero of the quartz compen- 
sating scale for which provision is made in his apparatus. A 
slight additional correction of the same character made at the 
same point will also serve to correct for the loss of light by 
reflection at the end surfaces, and by absorption within the 
small prism. Supposing this to amount to 10 per cent of the 
total intensity, the situation can be summed up as follows: 
If abe the angle between the two prisms of the Lippich polar- 
izer, I the intensity of the light from the large polarizer, then 

*Tt will be recalled that the Lippich system consists, either for monochro- 
matic light or with the quartz compensator and white light, of a large nicol 
in front of which is placed a small nicol covering one-half the field of the 
former. The plane of polarization of this nicol makes a small angle with 
the plane of the large nicol. In the matter of the loss of light at the surfaces 


and by absorption within prisms, the system is therefore not symmetrical 
with respect to the line dividing the fields. 


396 I ki. Wright—Bi-quartz. Wedge Piate. 


the intensity I’ of the light emerging from the small nicol 
will not be precisely I’ = I cos’ a, but I’. = 9 I cosa 

If the two fields are matched to show echal intensity, the 
plane of the analyzer will not in general coincide with the 
bisector of the angle a, but will include with it a smail angle 


6 (fig. 4). 


= 


An equation from which the angle 6 can be figured when 
a is given has been derived by Bates, but his expression as 
noted above does not take cognizance of the loss of light in the 
extra prism and accordingly requires slight modification. 
Let OP, = direction of plane of large polarizer 

OP, = direction of plane of small polarizer 

a = angle between two polarizers; angle between the 

normal (OC) to the plane of analyzer AA,, and I, intensity of 
light in the field covered by the large polarizer alone when 
viewed through analyzer; and I, intensity of light of the 
tield covered by the small polarizer. The angle P,OA angle 
between large polarizer and analyzer is 


T a 


eEONe =a 48 
while 
PIO AU eae, 
: ets) 


From the intensity formula of the preceding article : 


T= cosa OFA stay ( — 5) 


= 


L, "0 cosa cos’. < (POA 9 ‘costa sim € = 5) 
The condition of matched fields is 
es 


OG 


FE. Wright—Bi-quartz Wedge Plate. 397 


> 2 a a 9 . 2 a 
sini ote -9-€0s: a.Ssim x 23 


SANT 4 Gy A = eR: == (ee 
sin = cosd—cos= sin §=41/°9 cosa sin % cos 6+4/°9 cosa cos > sin 8 


=— = 


or 


sin © cos 8 (1 — V9 cos «) = cos 5 sin 5 (1 + /9 cosa) = 0 


1l— ‘9 COS 
io. — ee 
1 + 4/-9 cosa = 


or 
ess 1°05409 — cosa | a 
J° = 7-05409 + cosa” 2 
The formula of Bates expressed in this notation reads 
) SE. cos « 


oo cosa’ 


a 
and differs from the above only in the constant in the fraction. 
For the sake of comparison the angles § have been figured 
for a = 1° to 15° by both formulas and vlna in the e.g 
ing table: 


= 6 (new formula) 6 (Bates formula) 
SE Re Ap ape ey Sieur ee 0’ 0’ 

i Og Bee Sate Fabs [. 2! QO! 

9° 1a eae Rial ts a ar ite ae ar 0’ 

z4 ny le aa S ge, Ce lg aa AL a 4’ tw 

4° “aS ps patie Se an Balan pana as je 

=e es Wappen i 10’ 9! 5 
El ath hs pie 9 Sak ga ok Aa gs 14’ 4! 

Fae: ule Pande a A get Pea paca ley 6! 

Ragen ee een rte) am Wea SN IN LOY Taye 

Spee? ease Were FS Lt: ao! 14’ 
pees ee eee ED! 19’ 
[Rs es A ie dO ea 43 AS 
CET YOR Sek Gi mS 12 oon 
Rg ae a hs L203: AQ’ 
VACHE Re ASS DP aE Ce er ee fad 53 
TOSSA Gar Sh ee OE ee E30! bog! 


This table as well as a discussion of the two formulae shows 
that the angle 6 is increased in every instance by reason of the 
loss of light by reflection in the small nicol prism: 

These differences can be allowed for upon the scale of the 
quartz compensator. The operation for any angle a consists 
in first adjusting the zero of the quartz compensator scale 
with respect to the analyzer without intervening sugar solution 


Am. Jour. Sct.—Fourts Series, Vout. XXVI, No. 154.—OctToBer, 1908. 
28 


398 FE. Wright— Bi-quartz Wedge Plate. 


until the illumination of the two halves of the Lippich polarizer 
system is the same. After the introduction of the sugar 
solution, the quartz compensator is inserted until the original 
equal intensity of the halves is restored and the angle of rota- 
tion derived directly from the compensator scale. 

This being the case, it would considerably simplify the con- 
struction to allow the analyzer to remain rigidly fixed and to 
revolve the two nicol prisms of the Lippich polarizer system, 
thus eliminating the complicated gearing of the Bates ‘polar- 
iscope, which mechanically i is an exceedingly difficult piece of 
apparatus to construct and to operate without lost motion. The 
revolution of the polarizing prisms in equal and opposite angles 
can be accomplished either by means of the worm thread device 
adopted in the binocle ocular of fig. 11 of the preceding article, 
or by a grooved arm into which pins connected with the sup- 
porting collars of the nicols fit and slide as the arm is inserted. 
Mechanically these devices are not difficult of construction and 
the angle of revolution can be read off accurately. 

In the foregoing pages the bi-quartz plate wedge is suggested 
as a simple and effective basis for the construction of a polar- 
imeter of adjustable sensibility in which the error from the 
asymmetry of the Lippich system, together with all the serious 
complications of mechanism, are completely avoided without 
loss of accuracy. Such a plate has been constructed and 
successfully applied to the exact location of crystal extinctions, 
but unfortunately pressure of other duties has prevented the 
writer from actually constructing a saccharimeter. Through 
the courtesy of Dr. Bates of the Bureau of Standards, however, 
an opportunity was given to test the wedge on a large and 
accurate standard polarimeter illuminated by homogeneous 
green light from a mercury quartz-glass arc. Its performance 
was entirely satisfactory, minute displacements of the analyzer 
from its position of true extinction being readily detected. 


Geophysical Laboratory, 
Carnegie Institution of Washington, 
Washington, D.C., July 6, 1908. 


Chemistry and Physics. 399 


Se EE NEI EEG ENTE LLIGEN CE. 


I. CHEMISTRY AND PHYSICS. 


1. Determination of Phosphorus in Phosphor Tin.—GEMMEL 
and ArcusBuTt have devised a new method for making this some- 
what troublesome determination. They place two to five grams 
of the sample in a 500° Jena flask fitted with a tap funnel and 
delivery tube. The tap funnel has a two-way stop-cock, allowing 
gas or liquid to be introduced as desired. ‘The absorption appa- 
ratus consists of three Drechsel bottles, the first two charged with 
bromine and water, the last with bromine water only. The air is 
first removed by passing carbon dioxide, then 50 to 100° of con- 
centrated hydrochloric acid are introduced, and the contents of 
the flask gently heated and finally boiled until the substance is 
dissolved. Finally a current of carbon dioxide is again passed 
through the apparatus in order to drive forward any remaining 
traces of hydrogen phosphide, the liquids in the absorption 
apparatus are transferred to a beaker, evaporated to small volume, 
and the phosphoric acid is precipitated. with magnesium mixture 
in the usual manner. It is to be observed that any arsenic present 
in the substance would pass over with the phosphorus, but the 
authors did not find this element present in the samples that they 
examined. It was found that the actual evolution and absorption 
occupies less than twenty minutes, so that the process is shorter 
and simpler than those usually employed: Upon comparison with 
the methods consisting in the fusion, with “hepar sulphuris ” and 
with potassium cyanide, of the products of treatment with nitric 
acid the new method was found to give much more concordant 
results.—-Jour. Soc. Chem. Indus., 1908, 427. H. L. W. 

2. Complex Calcium Salts.—By the action of cesium sulphate 
solution upon gypsum, D’Ans has prepared a very stable double 
sulphate Cs,Ca,(SO,),.. The calcium alkali double sulphates now 
known, of which the first is the mineral syngenite, are as follows: 


K,Ca(S0O,),.H,0 elite K,Ca,(SO,),.H,O 
(NH,),Ca(SO,),.H,0 (NH,),Ca,(SO,),  (NH,),Ca,(SO.)..H.O 
Rb,Ca(SO,),.H.O Rb,Ca,(SO,), sans 


ioe CO,Ca,(SO,), pf Weare 


D’Ans has prepared also two interesting triple salts analo- 
gous to polyhalite, Ca,MgK,(SO,),.2H,O. These are the salts 
Ca ,Cu(NH,),(SO,),.2H,O and Ca,CdK,(SO,),.2H,O, which were 
prepared by boiling solutions of thé proper salts with gypsum. 
It is probable that a considerable number of compounds analogous 
to polyhalite and to krugite, Ca,MgK,(SO,),.2H,O, may be pre- 
pared, and it is the author’s intention to continue his investigations 
in this direction.— Ber tchte, xii; 1776. IS OOD Daye 


400 Scientific Intelligence. 


3. Radio-activity.—MAarcKwa tp has recently delivered a lecture 
before the German Chemical Society giving a good account of 
what has been done in the field of radio- activity, and discussing 
the prevailing views in regard to this subject. While this lecture 
contains little that is new to those who are familiar with the 
literature of the subject, it will be useful to those who desire a 
general knowledge of this new branch of science. The author 
gives a somewhat novel view of the enormous ener gy involved in 
the transformation of the radio-active elements by saying: “It 
was the dream of the alchemists to transmute base metals into 
noble ones. ‘The radio-active substances teach us that, if this | 
process could be achieved, there would either be obtained at the 
same time so much energy that in comparison to it the value of 
the noble metal would be insignificant, or on the other hand the 
consumption of energy w ould render the ennobling of the metal 
practically uneconomical.”— Berichte, xli, 1524. He We 

4. A Simple Method for Determining Vapor Densities.— 
BiackMAN has devised an apparatus for this determination, which 
consists of a sealed tube in which is placed a capillary tube 
graduated in millimeters, closed at one end, and supplied with a 
thread of mercury at the other ena in order that it may serve as 
a manometer. It is evident that when this system is heated with 
nothing but air within and without the manometer the pressures — 
will continually balance each other ; but in the operation of deter- 
mining a vapor density a weighed amount of volatile substance 
is placed in the sealed tube with the manometer, and when this 
substance is volatilized by heating it exerts a pressure which can 
be measured by the movement of the thread of mercury in the 
capillary manometer. Then, when the two temperatures and the 
volume of the apparatus are known, the vapor density of the sub- 
stance can be calculated from the pressure produced by it. The 
calculations are somewhat complicated, and the execution of the 
operation does not appear to be as simple with this apparatus as 
with that of Victor Meyer ; but the method is interesting in its 
novelty.—Zevischr. physikal. Chem., \xiii, 48. HH. L. W. 


lie <Guorocye 


1. La Montagne Pelée aprés ses Hruptions ; par A. Lacroix. 
4°, pp. 136, figs. 321, Paris, 1908 (pub. by the Academy of Sci- 
ences).—This is a supplement to the author’s great work La 
Montagne Pelée et ses Hruptions, published a few years ago and 
noticed in this Journal (vol. xix, 465). From a variety of sources 
the writer has collected a considerable body of facts, which 
interpreted by the light of his former investigations, he uses to 
describe the progressive changes which have occurred in the 
diminishing volcanic activity, and in topography, owing to 
erosion and the crumbling of the dome of lava. Very interesting 
are the views showing the rapid growth of vegetation everywhere 


Geoloyy. 401 


over the destroyed area, which now largely conceals the traces of 
the great catastrophe. Already the streets of Saint-Pierre are 
being cleared ont and are beginning to be rebuilt by the new 
population settling there. 

The writer discusses the structure of the dome of Pelée and, 
after comparison ef the texture of its rocks with those of Amer- 
ican laccoliths, is led to the conclusion that the effect of pressure 
in determining the micro-granular texture of quartzose igneous 
rocks is much less than has been generally supposed. 

In the third chapter different types of volcanic eruption are 
considered ; the author makes four classes: a, the Hawaiian, in 
which the lavas are extremely fluid and the vapors escape with- 
out causing projection of solid material ; 4, the Strombolian, in 
which the lava is more viscous and the escape of vapors takes place 
with explosive activity with the projection of some pasty mate- 
rial which falls as rounded, flattened bombs ; ¢, the Vulcanoan, 
in which the lava solidifies at the surface between eruptions, and 
this, and the very viscous condition it is in, causes the explosions 
and escape of the gases to be accompanied by quantities of 
broken solidified rock, which falls as angular bombs, lapilli, ete.; 
d, the Peléean, whose explosion occurs in material already solidi- 
fied, giving rise to incandescent clouds composed of an intimate 
mixture of gas and solid material whose weight is so great that 
they roll rapidly down the mountain side, if not contained more 
or less in a caldera of sufficient size,-producing the direful effects 
seen at Saint Pierre. It will be noticed that this classification is 
a progressive one depending on the proportions of gas and solid 
material and on the relative condition, liquid or solid, of the 
magma. It could be reduced to two, the Strombolian, of which 
the Ilawaiian is an extreme case in one direction, and the Vul- 
canoan, of which the Peléean is anextreme case in the other. These 
definitions, which are essentially those employed by the Italian 
geologists, are more precise than the “ quiet” and “eruptive” 
types of the geological text-books. 

The author calls attention to the fact that many volcanoes vary 
between these types according to the character of their magma, 
but that such variation may take place in the history of a single 
volcano and even in a single eruption. 

In the final portion of the work the writer discusses various 
phenomena occurring at Vesuvius in relation to those at Monte 
Pelée. He describes the avalanches of dry volcanic dust and 
ashes caused by the accumulations on the steep sides of the cone. 
These leave ravines behind them which become accentuated by 
rain wash and this produces the curious umbrella-like relief of 
the mountain. 

In conclusion a study of the facts obtainable of the eruption of 
°79, which destroyed Pompeii, leads the author to the view that 
this phenomenon was of the regular Vesuvian type, and that the 
destruction, occurring through a period of several days, was 
caused by the excessive fall of cold, or at least only warm, ashes 


402 Scientific Intelligence. 


and lapilli, aided by earthquake shocks. On the other hand, the 
occurrence at Saint Pierre, occasioned by the sudden descent of 
an incandescent cloud, is to be regarded as unique in the history 
of catastrophes caused by volcanic eruptions. LV ae 

2. Publications of the United States Geological Survey.— 
Recent publications of the U. 8. Geological Survey are noted in 
the following list (continued from p. 97 of this volume) : 

Torocrapuic ATLAs.— Twenty-seven sheets. 4 

Forios—No. 157. Passaic Folio, New Jersey-New York. 
Description of the Passaic Quadrangle; by N. H. Darron, W.S. 
Bayxry, R. D. Satissury, and H. B. Kémmer. Pp. 27, with 4 
maps. 

No. 159. Independence Folio, Kansas. Description of the 
Independence Quadrangle ; by F. C. ScurapEr. Pp. 7, with 
Table of Formation Names, 3 maps, and Columnar Sections. 

Monoerapu. -Vol. xlix. The Ceratopsia ; by Joun B. Har- 
CHER. Based on preliminary studies by Orunizen C. Marsu. 
Edited and completed by Ricuarp 8. Luty. Pp. 198, with xlix 
plates, 125 figures. This volume was noticed on page 98 of this 
volume. 

Professional Paper 62. The Geology and Ore Deposits of the 
Ceur D’Alene District, Idaho ; by FRepEricK LesLtiz Ransome 
and Frank Carscarr Cauxkins. Pp. 203, with xxix plates, 23 
figures. 

BuLietins.—No. 335. Geology and Mineral Resources of the 
Controller Bay Region, Alaska; by G. C. Martin. Pp. 141, 
with x plates, 2 figures. 

No. 337. The Fairbanks and Rampart Quadrangles, Yukon- 
Tanana Region, Alaska; by L. M. Prinpie. With a section on 
the Rampart Placers, by F. L. Hess: and a Paper on the Water 
Supply of the Fairbanks Region, by C. C. Covert. Pp. 102, 
v plates, 3 figures. 

No. 340. Contributions to Economic Geology, 1907. Part IL— 
Metals and Non-metals, except Fuels ; C. W. Hayes and Wat- 
DEMAR LINDGREN, Geologists in charge. Pp. 482, with vi plates 
and 26 figures. 

No. 344. The Strength of Concrete Beams. Results of Tests 
of 108 Beams (First Series) made at the Structural-material Test- 
ing Laboratories; by Ricnarp L. Humpsrey. Pp. 58, with I 
_ plate and 13 figures. 

No. 345. Mineral Resources of Alaska. Report on Progress 
of Investigations in 1907; by Atrrep H. Brooxs and others. 
Pp. 294, with v plates, 7 figures. 

No. 346. Structure of the Berea Oil Sand in the Flushing 
Quadrangle, Harrison, Belmont, and Guernsey Counties, Ohio ; 
by W. T. Griswotp. Pp. 28, with IL plates. 7 

3. Graptolites of New York, part 2, Graptolites of the Higher 
Beds, by R. Ruepemann, Mem. 11, N. Y. State Mus., 1908, pp., 
583, plates 31.—In this volume, indispensable both for students 
of graptolites and of stratigraphy, Doctor Ruedemann completes 


Geology. 403 


his studies of the New York graptolites above the lower third of 
the Ordovician. Part 1 was published in 1905. The last of the 
graptolites are found in the middle Devonian (Hamilton). He 
discusses 109 Ordovician, 25 Silurian and 11 Devonian forms. 

An interesting table shows the range of the graptolite genera 
of the United States; this brings out the fact that Dictyonema 
ranges through all strata in which graptolites occur, but as a rule 
the | genera are short-lived. There are three impor tant outbursts 
of generic development: (1) the dichograptid type of the lower 
Ordovician, (2) the dicellograptid-diplograptid of the middle 
Ordovician, and (3) the monograptid of the Silurian. C893 

4. Fourth Report of the Director of the Science Division, ete. 
N.Y. State Museum, Bull. 121, 1908, pp. 203, with many plates.— 
Theannual statement of progress in the various science divisions of 
the New York State Museum is here presented in interesting form 
by the Director, Dr. J. M. Clarke. A description is given of the 
new museum planned, as far as the ground plan is concerned ; 
the available space will be 80,000 square feet and the exhibi- 
tion rooms will be lighted from the top. The first American 
Helianthaster is described as #1. gyalum. The closing paper 
by the Director on “The beginnings of Dependent Life” 
describes the “ material from the faunas which might illuminate 
the incipient expressions of dependent life. It is through this 
avenue only that the problem of the origin of the symbiotic con- 
ditions which now pervade all nature can ultimately be approached 
with hope of resolution.” Chis; 

5. Rocks and Rock Minerals. A Manual of the Elements 
of Petrology without the Use of the Microscope ; by Louts V. 
Pirsson. Pp. v, 414. New York, 1908 (John Wiley & Sons).— 
Recent progress in the knowledge of rocks has so largely resulted 
from the development of the various methods of study employing 
the microscope that modern text-books of petrology have natur- 
ally been chiefly devoted to them. It still remains true, however, 
that from many points of view, scientific as well as practical, rocks 
must be studied by other than microscopic methods, and it is to 
this important side of the science that the present volume is de- 
voted ; its appearance will be welcomed alike by teachers, field 
geologists, and technical men. Such a volume has long been 
needed, and the author’s experience both in teaching and in active 
investigation has peculiarly fitted him for its preparation. The 
work as a whole, after two opening chapters of general character, 
is divided into two parts: the first (pp. 21- 131) deals with rock- 
making minerals, their characters and the methods for their deter- 
mination ; the second (pp. 132-408) discusses the various types of 
rocks, igneous, stratified, and metamorphic, closing with a chap- 
ter on their determination. The style is throughout clear and 
interesting, and abundant illustrations, largely from original 
sources, have been introduced ; the half-tone engravings espe- 
cially deserve commendation for their admirable execution, due 
to the fact that they have been printed, not with the text, as is 
too often the case, but as separate plates. 


404 Setenti fic Lntelligence. 


III. MusceLtuAnrous Sorentiric INTELLIGENCE. 


i. The Shaler Memorial Expedition to Brazil and Patagonia, 
1908-09, J. B. Woopworts in charge. [From a letter to the 
Editors, dated Curityba, Parana, Brazil, August 6, 1908.|—The 
members of the Shaler Memorial Expedition to Brazil reached 
Rio de Janeiro on the 8th of July. Since that time they have 
journeyed southwards through the states of Sao Paulo and Parana 
under the guidance of Dr. Derby, Director of the Geological Sur- 
vey of Brazil, in a reconnaisance of the conglomerate formations. 
of the Permo-Carboniferous, with a view to selecting areas for a 
more detailed study of the supposed glacial deposits of that 
terrane. On entering the state of Parana, in a railway cut 
between Itararé and the Rio Jaquaricatee, the writer was shown 
two bowlder beds in which well striated and scrubbed pebbles 
and stones were at once discovered; fragmental materials in all 
respects like those in the Pleistocene till beds of the glaciated 
area of North America and of the Permo-Carboniferous beds of 
South Africa and Australia. The work, in conjunction with Dr. 
Eusebio P. de Oliveiro, Assistant Geologist of the Geological 
Survey of Brazil, will now, be directed in part along the border 
of these deposits and the Devonian and Pre-Devonian erystalline 
terranes, to the finding, if possible, of a glaciated floor such as 
that already known in India, South Africa and Australia. 

J. B. WOODWORTH. 

2. British Association for the Advancement of Science.—The 
seventy-eighth annual meeting of the British Association, held at 
Dublin during the week beginning with Sept. 2, was remarkable 
for its size, 2270 members being in attendance. It was also nota- 
ble for the interest aroused by several of the addresses, as partic- 
ularly that of the President, Dr. Francis Darwin, (Nature, Sept. 
3) on the movements of plants, and that of Prof. John Joly on 
radium and its parent uranium as the source of the earth’s internal 
heat (ibid., Sept. 10). It is announced that the meeting of the 
Association in 1909 is to be held at Winnipeg from Aug. 25 to 
Sept. 1; that of 1910 at Sheffield and of 1911 at Portsmouth. 


OBITUARY. 


M. Antoine Henri BecQuEREL, the eminent French physicist, 
whose discovery of the so-called ‘‘ Becquerel rays” prepared the 
way for the important subject of radio-activity, died on August 
25 at the age of fifty-six years. 

M. E. E. N. Mascart, a second eminent French physicist, whose 
work lay chiefly in the departments of optics, electricity and 
magnetism, died on August 26 at the age of seventy-one years. 

Artuur Lister, of Leytonstone, England, well known for his 
work on the Mycetozoa, died on July 19 at the age of seventy- 
eight years. 

Pror. Autexis Hansky, of the Pulkowa Observatory, was 
drowned at Simeise in the Black Sea on August 11 ; although 
but thirty-six years old, he had already made important contri- 
butions to Solar Physics. 

J. KF. Nery Dexeapo, President of the Geological Commis- 
sion of Portugal, died on August 3 in his seventy-fourth year. 


Relicf Map of the United States 


We have just prepared a new relief map of the United 
States, 48 x 32 inches in size, made of a special composition 
which is hard and durable, and at the same time light. The 
map is described in detail in circular No. 77, which will be 


sent on request. Price, $16.00. 


WARD’S NATURAL SCIENCE ESTABLISHMENT, 


76-104 College Ave, ROCHESTER, N. Y. 


Warns Natura Science EstaBiisHMent 


A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 
DEPARTMENTS: 


Geology, including Phenomenal and Physiographic. 
Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, ete. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, ete. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Wards Natural Science Establishment, 
76-104 College Ave., Rochester, New York, U.S. A. 


CON THN Ds: 


Page 
Art. XX XIV.—Buried Channels Beneath the Hudson and 
ite “Tributaries * by J. F. KEMP <i. 20 3 ee 301 


XXXV.—Thomson’s Constant, e, Found in Terms of the 
Decay Constant of Ions, within the Fog Chamber ; by 
CG. Barts 2°. 2 * 324 


XXX VI.— Application of the Cobalti-Nitrite Method to the 
Estimation of Potassium in Soils; by W. A. DrusaEL_ 329 


XXX VII.—Iodometric Estimation of Chromic and Vanadie 


Acids in the presence of one another; by G. Epgar.__. 333 
XXX VIII.—Apatitic Minette from Northeastern Washing- 
tons by LL. RANSOME 2222052. 222) 26 337 


XX XIX.—Kroéhnkite, Natrochalcite (a new mineral), and 
- other Sulphates from Chile ; by C. Patacue and C. H. 
WARREN Uo SU ee ee 342 


XL.—Measurement-of Extinction Angles in the Thin Section; 
by HAE. WReigate 25 62 ee ee ee 349 


XLI.—Bi-quartz Wedge Plate Applied to Polarimeters and 
Saccharimeters ; by Be WRiehT 2252 - aee 391 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Determination of Phosphorus in Phosphor Tin, 
GEMMEL and ARCHBUTT: Complex Calcium Salts, D’Ans, 399. —Radio- 
activity, MARCKWALD: Simple Method for Determining Vapor Densities, 
Buiackman, 400. 


Geology—La Montagne Pelée aprés ses Eruptions, A. Lacrorx, 400.—Publi- 
cations of the United States Geological Survey : Graptclites of New York, 


part 2, Graptolites of the Higher Beds, k. RuepEMANN, 402.—Fourth — 


Report of the Director of the Science Division, ete., New York State 
Museum: Rocks and Rock Minerals; A Manual of the Elements of Petrol- 
ogy without the Use of the Microscope, L. V. Pirsson, 403. 


Miscellaneous Scientific Intelligence—Shaler Memorial Expedition to Brazil 
and Patagonia, 1908-09, J. B. WoopwortH: British Association for the 
Advancement of Science, 404. 


Obituary—M. ANTOINE HENRI BECQUEREL: M. EH. E. N. Mascart: ARTHUR 
LisTtER : ALEXIS Hansky: J. F. Nery Drweapo, 404. 


Librarian U. S. Nat. Museum. 


Memon. XXVI0 NOVEMBER, 1908. 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE. 


Epiror: EDWARD S. DANA. 


ASSOCIATE EDITORS 


Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or CamsBrwwce, 


Proressorss ADDISON E. VERRILL, HORACE L. WELLS, 
L. VY. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor GEORGE F. BARKER, or PumapsspHia, 
Proressok HENRY S. WILLIAMS, or Irnaca, 
Proressor JOSEPH S. AMES, or Battmonz, 
Mr. J. S. DILLER, or Wasnuinerton. 


FOURTH SERIES 
VOL. XXVI—[WHOLE NUMBER, CLXXVI.] 


No. 155—NOVEMBER, 1908. 


NEW HAVEN, CONNECTICUT. 
1908 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 


Published monthly. Six dollars per year, in advance. $6.40 to countries in the 
Postal Union ; $6.25 to Canada, Remittances should be made either by money orders, 
registered letters, or bank checks (preferably on New York banks) 


Rare Cinnabar Crystals from China. 


The first consignment of these rare specimens was sold on sight. We 
have now received a second consignment of all there are, as the mine is now 
filled with water. They come from Wanshanchang (Hamlet of Ten Thou- 
sand Hills), Tungyen Prefecture, Prov. of Kweichow, China. They occur in 
ordinary and interpenetrating twins of bright ruby red color. In size the 
crystals are from 14 to 34 inches. The matrix is a pure white quartz, the 
crystals always occurring in cavities, with quartz crystals; prices run from 

$10, $15, $20, $385, $50, $75, $100, $125 and $150. 


BEAUTIFUL ZEOLITES FROM THE NEW ERIE 
TUNNEL CUT AT BERGEN HILL, 
NEW JERSEY. 


In making the new Erie Rd. cut through Bergen Hill, some very remark- 
able and beautiful specimens of zeolites were found, and I had the good 
luck to szcure the cream of those found. We advise those who can to call 
personally and see these interesting and beautiful specimens. They consist 
of calcite in combinations with brilliant apophyllite, analcite, datolite, pyrite, 
and prehnite, with small mica crystals. 


RARE MINERALS AND NEW FINDS. 


Benitoite and Neptunite from San Benito Co., Calif.; Californite, Tulare 
Co., Cal.; Pink Beryl, Mesa Grande, Cal.; Diamond in matrix, New Vaal River 
Mine, S. Africa; Herderite, Auburn, Me.; Josephinite, Oregon ; Smithson- 
ite, Kelley, N.M.; Tetrahedrite, Cobalt, Ont. and Bingham, Utah; Vanadinite, 
Kelley, N. M.; Vivianite, large crystals, Leadville, Col. ; Wulfenite, Organ 
Mts., N. M.; Native Bismuth, Cobalt, Ont.; Atacamite, South Australia ; 
Niccolite, crystallized, Saxony, Ger.; Embolite, Broken Hill, Aus.; Argen- 
tite xls, Freiberg, Sax.; Pyrargyrite xls, Hartz; Crocoite, Siberia and Tas- 
mania; Jade, China; Opals, Barcoo River, brown matrix; Titanite, Tilly 
Foster and Switz. Sphene, Switz.; Gold, in matrix, Verespatak, Siebenburgen 
and Nova Scotia; Algadomite, Mohawkite, Domeykite var. stibio-domeykite, 
all from Keweenaw Co., Michigan; Tourmaline, in feldspar and quartz, 
also loose crystals, from Mesa Grande, Cal., all colors. 


REMARKABLE CUT GEMS. 


If you would like to secure some remarkable cut gems at a reduced price, 
you will have an opportunity to do so during November. We have a full 
stock of all sizes and all prices and will be pleased to quote same if you will 
give us an idea of what you want. Lots will be sent on approval to persons 
favorably known to us and to others sending satisfactory references. We 
name a few below: 

Green garnets, aquamarines, zircons, sapphires, star sapphires, star rubies, 
chrysoberyl, cats-eye, opals, topaz, spinel, pink beryls, sphene, tourmaline, 
amethyst, andaluzite, star quartz, peridote, reconstructed rubies and sap- 
phires, and other precious and semi-precious stones. 

Write for our 10-page Bulletin to-day. 


Ao. PETEREL: 
81—83 Fulton Street, New York City. 


ee i 


AMERICAN JOURNAL OF SCIENCE 


[OU RUE ES BE Rep Es ..] 


—__+++—__—_. 


Art. XLII.—Some New Measurements with: the Gas Ther- 
mometer; by Artuur L. Day and J. K. OCxemenr. 


First Paper. 


Many of the serious problems of rock formation are depend- 
ent upon the exact measurement of temperatures, in the 
region lying between 400° and 1600° C. It is, therefore, not 
surprising that a considerable portion of the energy of inves- 
tigators in this branch of geophysics (see in particular Barus, 
Bulletins of the U. 8. Geological Survey, No. 54) has had to 
be expended upon the methods and mechanism of high tem- 
perature measurement. This situation not only still exists, 
but the increasing perfection in other lines of geophysical 
analysis has created a demand for considerably higher accuracy 
in the temperature determinations, if such shall prove attain- 
able. This has been the chief incentive for the present long, 
difficult and still incomplete investigation of the gas ther- 
mometer. 

A discussion of gas thermometry in its more general aspects 
is not contemplated in the present article. This has been done 
from time to time by others,* and its underlying assumptions 
found to be sound and adequate. There is, therefore, no need 
to go over this ground again. On the other hand, there is no 
denying the fact that a great deal still remains to be done upon 
the experimental side before the steadily advancing require- 
ments of both science and industry in the matter of a trust- 

* See in particular the several papers of Chappuis, published in the Tra- 
vaux et Mémoires du Bureau International des Poids et Mesures and the 
Rapports présentés aux Congrés International de Physique; Carl Barus, 
Les Progres de la Pyrométrie, Rapports présentés aux Congrés International 


de Physique, voi. i, page 148; E. Buckingham, Bulletins of the Bureau of 
Standards, vol. iii, p. 237. 


Am. Jour. Sci.—Fourts SERIES, VoLt. XXVI, No. 155.—Novempser, 1908. 
29 


406 A. L. Day and J. K. Clement—Gas Thermometer. 


worthy temperature scale of sufficient accuracy and range can 
be satisfied. 

It is no disparagement of the present system of temperature 
definition to say that the gas thermometer itself is a compli- 
cated and cumbersome instrument to use in any of the forms 
which have hitherto been devised, and possesses limitations, 
both of range and of accuracy, which are very difficult to 
overcome. One consequence of this, particularly in the region 
of high temperature measurements, where errors of consider-. 
able magnitude still exist in the fundamental scale, is that 
temperature measurements easily come to receive a somewhat 
fictitious value in the hands of those who have never acquired 
a firsthand knowledge of these limiting conditions. This has 
been further facilitated by the comparative ease with which 
relative measurements of temperature can be made, even in 
the more inaccessible parts of the scale, with the thermoelement 
and the resistance thermometer. These devices are sensitive 
to temperature differences of the order of magnitude of -01° 
throughout their entire range, and yet depend absolutely upon 
fundamental measurements with: the gas thermometer for their 
evaluation in terms of the generally accepted degree centigrade. 
It is sufficiently obvious, though often carelessly overlooked, 
that no method of temperature measurement, however sensitive 
or adaptable it may be, can yield temperatures of greater abso- 
lute accuracy than the system in terms of which those temper- 
atures are defined. With the gas thermometer as our basis of 
definition, therefore, we shall know our temperatures with just 
the certainty which it is able to furnish and no more. There 
is, to be sure, some justification for expressing the results of 
thermoelectric or resistance measurements in units smaller than 
the errors of the fundamental scale, provided they are so 
recorded that they can be translated in terms of some more 
accurate fundamental system when future investigations shall 
have provided one, or where only comparative measurement is 
involved; but this is also frequently overlooked. 

The fundamental temperature scale now used is the centi- 
grade scale of the Bureau International des Poids et 
Mesures, determined with the constant volume hydrogen ther- 
mometer from an initial pressure of 1™ of mercury. _ Its inter- 
polation between the melting point of pure ice and the boiling 
point of pure water (0°- 100° yas probably accurate to the 
nearest °005°*; the extrapolation from 100°—300° may be in 

* The fundamental subdivision of the interval between the melting point 
of ice and the boiling point of water by means of the expansion of hydrogen 
was undertaken with great care by the Bureau International des Poids et 
Mesures (P. Chappuis, Trav. et Mem. d. Bur. Int., vol. vi) and is a work of 


such extraordinarily painstaking character in most particulars that no inves- 
tigator has found it necessary to repeat it. It is commonly accorded an 


A. £. Day and J. K. Olement—Gas Thermometer. 407 


error as much as *05°. The Reichsanstalt gas thermometer 
scale, which is now very generally used as the basis of high 
temperature measurements, is officially stated to have a prob- 
able error of 2° or 3° between 300° and h150% arid of 100% 
between 1150° and 1600.° 

The gas thermometer problem is one in which theory is often 
inclined to lose patience with practice. It has been demon- 
strated over and over again, for example (Barus, Buckingham, 
loc. cit.), that the constant: -pressure system of measurement 
ought to be more direct and free from error than the constant- 
volume system, notwithstanding which the major portion of the 
results which go to make up the real progress of the past fifty 
years has been obtained through the use of the constant vol- 
ume principle. Theory has also been very apprehensive from 
time to time of the ultimate outcome of attempting to define 
temperature in terms of the expansion of a diatomic gas, and 
yet nitrogen is the only gas which has yet been found practi- 
cable fer long ranges extending to the higher temperatures. 
It does not react with a platinum bulb and does not diffuse 
through its wall, and so far (up to 1600°) it has not been found 
to dissociate. From the laboratory side of gas thermometry, 
the main difficulty is now, as it has always been, to find a prac- 
ticable bulb which will hold some expanding gas without loss 
or change through a long range of temperatures and permit 
sufficiently accurate measurements of the pressure-volume rela- 
tion within. After more than three-quarters of a century of 
the most varied experiences, pure nitrogen in a platin-iridium 
bulb in which the pressure at constant volume can be measured, 
is the only arrangement which has not yet encountered some 
very serious obstacle to the extension of its range or its accu- 
racy. It was therefore adopted without hesitation for the 
study here described. 
accuracy of about ‘001°, but this is probably too high on account of the 
uncertainty in the determination of the expansion coefficient of the ther- 
mometer bulb. This bulb was of platin-iridium (90 Pt, 10 Iz) of 1 liter 
capacity, and the determination of its expansion coefficient had been made 
by Deville and Mascart, but this determination was rejected in favor of 
Benoit’s value, which was obtained with a different platin-iridium bar. The 
difference between the two determinations amounts to ‘007 per cent at 50°, a 
quantity sufficient to affect the temperature scale at that point by about ‘004°. 
The measurements of the same alloy which were made for the present paper 
(page 440) differ from Benoit’s by an amount equivalent to ‘002° at 50°. 
There are also differences between the results obtained by Benoit himself for 
different bars which exceed ‘003° when interpreted in terms of the tempera- 
ture. It is perhaps significant that these alloys were prepared before the 
work of Mylius on the exact determination of the platinum metals had been 
done. The difference may therefore point to considerable variations of com- 
position in the alloys employed. At any rate, the uncertainty here is out of 
all proportion to the accuracy of the remainder of Chappuis’s work (see also 


P. Chappuis, Rapports présentés au Congrés International de Physique, vol. 
i, p. 187, 1900, footnote 1). 


408 <A. L. Day and J. K. Clement—Gas Thermometer. 


If this somewhat cireumstantially selected system does not 
at the moment appear to confront any insuperable obstacle, 
many and insidious difficulties have been encountered in the 
course of its development. One has only to examine the 
determinations of the same temperature made by different 
observers, all using substantially this method, to become con- 
vineed that some serious work still requires to be done to clear 
up the present uncertainty. The melting point of gold is 
given by Barus (1892) at 1092°; by Holborn and Wien (1895), 
1072°; Holborn and Day (1900), 1063°5°; by Jacquerod and 
Perrot (1905), 1067:2°; by Day and Clement (preliminary, 
1907), 1059-1°. For the moment it is sufficient merely to call 
attention to these differences in the results which have been 
obtained, and to reserve detailed comment upon them for a 
subsequent part of the paper. Suffice it to say that both Hol- 
born and Day at the close of their work (1900) entertained the 
positive opinion that the discrepancies had occurred in the 
experimental details and were not chargeable to an oversight 
in any of the more fundamental relations involved. 

With this prevailing idea in mind—that the general relations 
are already satisfactorily worked out and that the problem 
remaining is therefore primarily an experimental investigation, 
(1) to increase the absolute accuracy of the measurements, and 
(2) to extend their range—Prof. Holborn at the Reichsanstalt 
and the authors at the Geophysical Laboratory took up the gas 
thermometer again in 1904. The details were for the most 
part independently planned and the work has been imdepen- 
dently carried out. In a research which offers so many 
technical difficulties, two independent plants were obviously 
better than one. In so far as a division of labor was 
attempted, Prof. Holborn entered at once upon the more daring 
undertaking, namely, to increase the range of measurement. 
He built a bulb of pure iridium in the hope that it might prove 
possible to make continuous gas thermometer measurements as 
far as the melting point of platinum. For this work the 
errors of observation were allowed to remain large, larger in — 
fact than they had been in the joint work of Holborn and Day 
in 1900. The undertaking was entirely successful and yielded 
very satisfactory measurements up to about 1600°,* the error 
for the new portion of the gas scale (from 1150° on) being 
about 10°. 

Our work was for the moment restricted to 1200° in an 
effort to eliminate or materially to diminish the errors which 

*Temperaturmessungen bis 1600° mit dem Stickstoffthermometer u. mit 
dem Spektralphotometer, Sitzungsber. Berl. Akad. xliv, p. 811, 1906; Hin 


Vergleichung der Optischen Temperaturscala mit dem Stickstoffthermome- 
ter bis 1600°, Ann. d. Phys. (4), xxii, p. 1, 1907. 


A. L. Day and J. K. Clement—Gas Thermometer. 409 


have been inherent in all gas thermometer measurements up 
to this time. Progress is necessarily slow in work of this 
character, but we were chiefly delayed by having to build the 
entire equipment ab initio, except the bulb.* 

The instrument which we constructed for this work has now 
been in operation for more than three years, but has never 
been described in print. It is of the constant volume type, as 
has been explained, similar in general plan to that at the 
Reichsanstalt, but differmg from it in certain important details 
with the especial purpose of correcting some of the known 
errors of the Reichsanstalt instrument: (1) A uniform temper- 
ature along the thermometer bulb appeared to us imperative, 
and a much greater effort was made to obtain it; (2) the entire 
‘furnace was enclosed in a gas-tight bomb in pales that a nitro- 
gen atmosphere might be maintained with equal pressures, 
both inside and outside of the bulb. This had the effect of 
obviating any tendency of the gas to diffuse into or out of the 
bulb, and allowed no opportunity for the deformation of the 
bulb through differences between the pressure within and 
without. A further effect of this arrangement was to increase 
the sensitiveness of the instrument fully threefold. It has 
been the practice heretofore in such temperature measure- 
ments to greatly reduce the initial pressure of the gas in 
order that its final pressure at the highest temperature to be 
measured may be substantially equal to the atmospheric pres- 
sure without, in order that the strain on the bulb through 
pressure difference may be least when its power to withstand 
such strain is smallest. In the Reichsanstalt instrument, this 
restricts the available range of pressure for a temperature 
eee from 0°-1150° to about 500™ of mereury, or less than 

0 eee per degree. By arranging to increase the pressure out- 
side the bulb as the pressure within increases, this restriction 
falls away and it is possible to extend the pressure range over 
the whole length of the scale which the manometer carries. 
The scale of our instrument was 1'8 meters long. For a 
range of 1200°, therefore, we were able to work with a sensi- 
tiveness of a little more than 1™™ for each degree centigrade, 
or rather more than three times the sensitiveness used in the 

*The bulb which was used for all the measurements here recorded was 
one of two bulbs made by Dr. Herzus, of Hanau, Germany, for the Holborn 
and Day investigation at the Reichsanstalt, one of which contained 20 
per cent iridium and the other 10 per cent. The 20 per cent iridium bulb is 
still at the Reichsanstalt and was used in the publications of Prof. Holborn to 
which reference has been made. The 10 per cent iridium bulb was exhibited 
by Dr. Herzus at Paris, after which it was loaned to us for this investiga- 
tion. The form and capacity of the two bulbs were substantially the same, 
about 200°. 

The authors take this opportunity to express their thanks to Dr. Hereus 


for his most cordial and effective codperation throughout this undertaking, 
and for his personal interest in the vutcome of it. 


410 A. L. Day and J. K. Clement—Gus Thermometer. 


Reichsanstalt instrument, and also to vary the initial pressure 
considerably without serious loss of sensitiveness. (3) In the 
capillary connecting link between the bulb and the mano- 
meter, we were able to diminish the volume of the unheated 
space to about one-third of its former value, and thereby still 
further to reduce one of the classical errors of gas thermometry. 
This ‘unheated space,” * it will be remembered, serves to con- 
nect the bulb which contains the expanding gas at a certain 
temperature and pressure, with the manometer in which the 
pressure is measured. This space is therefore filled with gas 
which forms a part of the total gas content of the bulb, but is 
not heated with it and therefore requires a correction the 
magnitude of which has sometimes been so great as to create 
misgivings about the trustworthiness of the resulting pressure 
obtained.t The ratio of the volume of the unheated space to the 


total volume of the bulb (=) in the final form of the gas ther- 


mometer used, by Holborn and Day amounted to :0046; in the 
more recent instrument used by Jaquerod and Perrot, to -0180 ; 
while in our instrument it was reduced to ‘0015. The entire 
correction for the unheated space im our instrument there- 
fore amounted to less than 5° at. 1100° compared with about 
20° in the older Reichsanstalt instrument and about 80° in 
the instrument used by Jaquerod and Perrot. An error of 
10 per cent in the determination of the average temperature 
of the unheated space in our instrument will not therefore 
affect the result more than °5° at this temperature. (4) The 
expansion of the bulb itself was redetermined with much 
greater care than before. 

All these are details the importance of which we have come 
to estimate very highly, if a really accurate temperature scale 
based upon the expansion of a gas is to be established. The 
effect of aserious error in any one 2 of the four particulars noted 
upon the temperature measurement is several times greater 
than that arising from differences in the expansion of thevari- 
ous available gases which formed the basis of the elaborate 
study by Jaquerod and Perrot to which reference has just been 
made. And here, perhaps, lies the kernel of the whole matter 
so far as it concerns the establishment of accurate fundamental 
temperatures in a region as remote as 1000° from the funda- 
mental fixed points. The interest of observers is easily diverted 
to questions of general aud theoretical interest, like the validity 
of the Gay-Lussac law over great temperature ranges, while 
experimental conditions which permit errors of considerable 

* « Hisnéce nuisible,” ‘‘ Schadlicher Raum.” 


+See in particular Jaquerod and Perrot, Arch. d. sci. phys. et. nat., 
senéve (4), xx., pp. 28, 128, 454, 506, 1905. 


A. L. Day and J. K. Clement—Gas Thermometer. 411 


magnitude in an absolute scale attract altogether inadequate 
attention. This is obviously no aspersion upon the beautiful 
work of Jaquerod and Perrot, or of any other investigator, but 
it may be the explanation of ‘the uncer tainty in existing high 
temperature measurements. Jaquerod and Perrot, for example, 

measured the melting point of gold with the gas ther mometer, 

using five different gases successively in the same (fused silica) 
bulb, with a maximum variation of only ‘4°, and yet in its 
absolute value the determination may easily be 5° or more in 
error. In fact, in one of their determinations in which a por- 
celain bulb was substituted for silica, a difference of 4° 
appeared. The observation was dropped, but it serves to direct 
attention sharply to a possible uncertainty of several degrees 
arising from the corrections for the distribution of temperature 
along the bulb and the unheated space, and for the expansion 
coefiicient of the bulb itself. 

Somewhat more in detail, the apparatus may be described 
as follows: 

The Furnace.—The furnace consists of a wrought iron tube 
of about 25°" inside diameter, carrying a cast iron pipe flange 
at each end. To these flanges cast iron covers were fitted by 
grinding to a gas-tight joint. In position this bomb is vertical, 
and the lower cover is permanently secured in place with bolts. 
The furnace tube is made irom a magnesite mixture* about 
36™ long and 6 inside diameter within which the furnace 
coilis wound. This scheme of winding the heating coil on the 
inside of a refractory tube is very successful in its operation 
and is not ditticult. With a pure platinum coil (melting point 
about 1750°) a furnace temperature of 1600° can be reached 
without danger to the coil and maintained for some time if 
desired. There is considerable loss of platinum through 
sublimation in maintaining a resistance furnace at this tempera- 
ture, so that it is necessary to use a wire of considerable size if 
it is required to maintain so high a temperature for long periods 
of time. The gain over the same coil wound on the outside of 

a thin porcelain tube is about 200° (1600° instead of 1400°) 
for the same current and conditions of insulation. The method 
of winding is simple. A series of five wooden wedges is 
grouped together so as to collapse when the center one is 
removed. When grouped and fastened together the outside 
surface is turned down to a cylinder of exactly the size which 
the finished coil is to have. This multiple wedge then serves 
as a collapsible arbor and the coil is wound upon it with any 
desired arrangement of turns. A piece of paper or thin card- 
board between the wire and the arbor sometimes facilitates the 
removal of the arbor after completion. The arbor with the 


* Harbison-Walker Refractories Company, Pittsburg, Pennsylvania. 


412 A. L. Day and J. K. Clement—Gas Thermometer. 


coil upon it is then placed in position in the cylinder and the 
remaining space between it and the cylinder wall filled with 
magnesite cement of the same composition as the tube itself. 
When this has set the arbor can be removed, leaving the coil 
in position in the tube. It then remains merely to go over the 
exposed wire with a very thin coating of the same cement and 
the coil is ready for use. Such a coil is less liable to displace- 
ment through expansion and contraction than when the wind- 
ing is on the outside of the tube. We have had such coils in 
constant use for a variety of purposes in the laboratory for 
several years, and have found them durable, economical and 
most convenient. 

In this particular furnace the windings are somewhat closer 
at the top and bottom of the coil than at the middle, in order 
to provide a more uniform temperature from one end to the 
other. This scheme, although efficient and perfectly satis- 
factory for most purposes, will not provide a perfectly uniform 
distribution of temperature over long temperature ranges. 
An arrangement of the turns which is adequate for low temper- 
atures will not provide sufficient compensation at the ends for 
much higher ones. We therefore prepared two secondary 
coils of finer platinum wire in which the current could be 
independently varied, and mounted them within the main coil 
at the two ends of the tube. These coils extended into the tube 
about 7°" from each end and were fastened in position by smear- 
ing with the magnesite cement as before. With this arrange- 
‘ment, we are able to obtain a temperature distribution along the 
bulb which did not vary more than 1° for all temperatures up 
to 1200°. We have not yet attempted to go beyond this point. 
To ascertain exactly what the temperature distribution was at 
the moment of any pressure measurement, it was necessary to 
use three thermoelements simultaneously, one principal element 
at the middle of the bulb and secondary elements at each end. 
These elements were carried out of the furnace between two 
discs of rubber packing in the center of the cover. 

The bulb was symmetrically located in the center of this 
furnace, the capillary stem extending out of the top of the 
heating ‘tube and then with a gentle bend of 90° passing out of 
the metal bomb at the side of the cover, as can be seen in the 
diagram (fig. 1). It was then connected by means of a second 
smaller capillary of platmmum with the top of the manometer 
tube near the point of constant level adjustment. The iron 
bomb thus prepared was water-jacketed around the sides and 
at the top and bottom, which effectually prevented any of the 
furnace heat from reaching the manometer which stood beside 
it. The scale and mercury columns of the manometer therefore 
suffered no exposure to temperature variation other than that — 


A. L. Day and J. Kk. Clement—Gas Thermometer, 4138 


which existed in the room, and the latter, if serious, as it some- 
times was in the summer months, yielded to the increased air 
circulation produced by an electric fan. 

When the furnace was mounted in position, the cover, fan 
which hung the thermoelements and the bulb, was permanently 


ines, 1 


«-Thermoelements 


i Pressure 


Un 
SSS SS SSS 


a 


OAS BSSSSSSSSSSSSSSSSSSSSS SSSSSSS SESS SSSSSSSSSS 


€ 
oO 
oO 
t+ 
| 
' 

t 
f 
| 

I 
t 
I 
! 
| 
! 
{ 
' 
\ 
t 
! 


<3omye 


Fig. 1. A section through the gas thermometer furnace (about one-sixth 
natural size). The bulb is shown in position with the furnace closed ready 
for heating. The capillary tube connecting with the manometer passes out. 
of the furnace through a packed joint at the upper right-hand corner. The 
thermoelements pass through the center of: the cover as indicated. The 
water-jacketing is sufficiently complete so that tight joints are readily 
obtained with ordinary rubber packing. 


fixed upon three upright steel rods. The body of the furnace 


bomb was then arranged to be lowered away from the cover by 


sliding upon two of the rods so as to expose the bulb and ele- 


414 A. L. Day and J. K. Clement—Gas Thermometer. 


ments for ice and boiling-point determinations before and after 
each heating. The photograph (fig. 2) shows the furnace 
body lowered in this way, leaving the bulb free and completely 


Hie. 2: 


Fic. 2. Photograph of the gas thermometer and accessory apparatus. — The 
gas thermometer measurements contained in the present article were finished 
in May, 1907. The photograph was taken in July, 1908, after certain details 
of the apparatus had been changed preparatory to measurement of much 
higher temperatures. The photograph therefore differs in certain minor 
details from the diagram (fig. 3) and from the description contained in the 
text. The apparatus is shown with the furnace open and ready for the ice- 
point determination. 


A. L. Day and J. K. Clement—Gas Thermometer. 415 


accessible for arranging an ice bath for the zero reading. 
Hydraulic power served to raise and lower the furnace con- 
veniently. When the furnace was raised for heating, a circle 
of bolts provided a positive pressure upon the top joint. 

The Manometer.—The manometer was located about 1/2™ 
distant from the furnace and was of the usual U-tube type, 
constructed with a very heavy cast-iron base and light upper 
parts in order to render the mercury columns as free as pos- 
sible from the vibrations of the building. The fixed point to 
which the mercury level was always adjusted occupied the 
usual position at the top of the short arm, the other arm 
extending upward for a distance of about two meters. 

The scale, which was 1°8 meters long, was immediately 
beside the long tube, and was provided with a sliding vernier 
reading to 0° 01", It was of brass with a silver- plated band 
upon which the divisions were ruled and had been calibrated by 
the German Normal Aichungskommission in Charlottenburg. 
The length of any portion of it was known in terms of the 
German standard meter to the nearest ‘01"™. The scale was 
fixed in position below and arranged so as to expand upward 
through appropriate guides against a rubber cushion with the 
changes in the room temperature. The long manometer 
tube also passed through three guide screws at the top of 
the apparatus, which allowed it to expand and _ contract 
unhindered. Readings were obtained by means of two paral- 
lel knife edges on the vernier carriage, which could be brought 
to accurate tangency with the mercury meniscus by a slow 
motion screw provided for the purpose. The mechanical con- 
struction was extraordinarily rigid and very satisfactory. The 
temperature of the scale and mercury columns was obtained 
from three thermometers, each set in a short tube of mercury 
after the manner of Holborn and Day.* Each tube with its 
thermometer could be moved up and down close beside the 
scale and mercury columns so as to give the temperature of 
the top, middle and bottom of the longest column. The 
observed temperature differences along the mercury column 
sometimes amounted to 1°. This would not affect the scale 
length by a dangerous amount, but the average temperature of 
the mercury column requires to be known to about 0°2°, 
with the high sensitiveness of this instrument, in order to 
bring the errors in the pressure determination within the 
desired limits—hence the three thermometers. 

The mercury supply was contained in two basins, one a 
hollow steel bomb enclosed within the cast-iron base of the 
instrument, and the other a steel flask mounted upon the wall 


* Holborn and Day, On the Gas Thermometer at High Temperatures, this 
Journal (4), viii, p. 170, 1899. 


Clement— Gas Thermometer. 


oa 


y and J. K 


Li Da 


416 A. 


To dry bottle @ 


Platinum 
Capillary 


-eighth size) showing con- 
re approximate. 


10NS a 


. 


A diagram of the manometer (about one 


Fie. 3. 
struction and essential features only. Dimens 


A. L. Day and J. K. Clement—Gas Thermometer. 417 


of the room near the ceiling and connected with the lower 
reservoir by a flexible iron tube. Cocks conveniently arranged 
admitted mercury whenever required. ‘The fine adjustment of 
the mercury level was obtained by the use of a nickel diaphragm 
which formed the bottom of the lower steel reservoir. This 
diaphragm was about 12° in diameter and could be raised 
slightly by the upward pressure upon its center produced by 
turning a milled hand screw convenient to the hand of the 
operator. The lower reservoir was dome-shaped within and 
opened into a tube and stop-cock at its highest point, through 
which any air which might chance to become imprisoned within 
the reservoir might be allowed to escape. 

Gas was admitted to the bulb by means of the three-way 
cock A (fig. 3) leading to a supply of pure nitrogen, the pres- 
sure of which could be varied at convenience. It was also 
possible to exhaust the bulb through the same cock for the 
purpose of testing for leakage or rinsing the bulb. 

Unheated Space.—F rom the point of view of the errors of 
the instrument, the most important part of the manometer is 
the nickel cap at the top of the short arm which carries the 
fixed point for defining the constant volume. This cap 
is sealed into the glass manometer tube with ordinary seal- 
ing wax of good quality, some care being taken that the seal- 
ing wax fills all the cracks, which might otherwise retain gas 
and become a part of the unheated space. ‘The under side of 
the cap is hollowed out slightly to conform to the shape of the 
rising mercury meniscus, and in the center a somewhat rounded 
point of nickel projects downward about °3"™. When the 
column of mercury is raised in the arm until it becomes tan- 
gent to this point, the constant. volume of the system is deter- 
mined. The setting is. made through a fixed magnifying 
microscope of some twenty diameters power. The portion of 
the “unheated space” included above the column is about °3™™ 
thick, 1°" in diameter, and corresponds in form to the mercury 
meniscus. 

The outlet leading to the bulb is a small opening beside the 
contact point containing a tiny valve of nickel about 1°5™™ in 
diameter and 2"™™ long, with a ground joint at the top which 
slides loosely in such a way that if an accidental rise of the 
mercury column should tend to drive the mereury over into 
the bulb, this little nickel plug will be lifted by the mercury 
and automatically close the opening at the ground joint. This 
tiny valve opens into the capillary (‘5™™ diameter) leading 
outward to the bulb. Fig. 3 will show the construction more 
clearly. Where the space above the mercury column requires 
to be reduced absolutely to minimum volume some such pro- 
tection is essential. If mercury once passes this opening, 


£1. 4 Day and J. K&. Clement—Gas Thermometer. 


through accident or oversight, it reaches the bulb almost 
immediately, and once there, it is a matter of two weeks 
boiling with nitric acid to get rid of it again. 

Even with this valve, it sometimes happened that when gas 
was bubbled through the mercury in filling, even at the bot- 
tom of the tube some 80° distant from the valve opening, 
tiny globules of mercury were shot upward with such speed 
and accuracy of aim as to pass up beside the little valve and 
into the capillary tube, after which their ultimate destination 
is inevitably the bulb. The altogether insignificant size of the 
opening and the distance required to be traversed by such a 
globule did not convey to us a suspicion that a globule might 
‘hit and pass it, but it actually happened on two different 
occasions, with the consequence of an exasperating delay. 

In the present arrangement of the gas thermometer, this 
accident is also provided against by introducing a gold capillary 
instead of platinum, between the fixed point and the bulb. 
Such microscopic globules of mercury are taken up by the gold 
without reaching the bulb and therefore remain harmless. 

Barometer.—It was deemed advisable from the start not to 
attempt to combine the barometer with the manometer as has 
usually been done by the French observers. It is a convenient 
method and is rather necessary if a single observer is to make 
all the readings, but the combination brings three or four 
essentially different errors into one reading in a way that does 
not admit of an intelligent evaluation of their individual mag- 
nitudes. 

Two barometers were used throughout this imvestigation, 
both of Fuess manufacture and of the same type (Wild. Fuess 
Normal Barometer, 14™" tube). The corrected readings of the 
two instruments were in perfect accord and were correct in 
their absolute value within -05™".* 

Thermoelectric Apparatus.—The thermoelectric measure- 
ments were made with apparatus and by methods which have 
already been described in varying degrees of fullness in pre- 
vious publications from this laboratory.t 

Briefly, it may be noted in passing that all the thermoelectric 
measurements without exception were made with platinum- 
platin-rhodium thermoelements of Herzeus manufacture on a 
potentiometer of Wolff standard construction by direct com- 

*One of these instruments was compared with the normal barometer at 
the U. S. Weather Bureau at Washington, the other at the Bureau of 
Standards. 

+ Day and Allen, The Isomorphism and Thermal Properties of the Feld- 
spars, Publications of the Carnegie Institution of Washington, No. 31, 1905, 
Allen and White, On Wollastonite and Pseudo-Wollastonite, Polymorphic 
Forms of Calcium Metasililicate, this Journal (4), xxi, p. 89, 1906; Walter P. 


White, Potentiometer Installation, especially for High Temperature and 
Thermoelectric Work, Phys. Rev., xxv, p. 384, 1907. 


A. L. Day and J. K. Clement—Guas Thermometer. 419 


parison with a saturated cadmium cell. The cell was one of a 
series described in a previous paper * which has been compared 
from time to time with the standard cells of the National 
Bureau of Standards and has never been found to contain an 
error greater than one or two parts in 100,000. The gaiva- » 
nometer was a Siemens and Halske instrument of the usual 
moving-coil type. With the help of a small rheostat in series 
with the galvanometer, the sensibility was maintained at a con- 
stant value such that one scale division in the telescope (distant 
1:5" from the galvanometer) corresponded exactly to two micro- 
volts in the thermoelement reading, which is roughly equivalent 
to one-fifth of 1°. In this galvanometer the wandering of the 
needle from its zero position was slight and never amounted to 
more than -2 or °3 of a scale division. It was also almost abso- 
Iutely dead beat with a period of about five seconds, so that 
adjustments for a temperature reading could be made with 
extraordinary rapidity and with an accuracy out of all propor- 
tion to the needs of the experiment. 

The only error to which the thermoelectric observations 
were subject was the contamination arising from the iridium 
contained in the bulb. During the first year in which these 
observations were begun the furnace coil also contained ten 
per cent of iridium, but at that time the contaminating effect 
of this metal upon a thermoelement was not well understood. 
Later on, this coil was exchanged for a coil of pure platinum 
made especially for this purpose by Dr. Herzeus, which was 
guaranteed to contain no more than 0-05 per cent iridium and 
which was found upon analysis to contain considerably less 
than this quantity. Inasmuch as the furnace coil is always the 
hottest part of the system, this afforded considerable relief, but 
the position of the elements in contact with the bulb made it 
impossible to prevent some contamination above 900°, so long 
as the bulb remained bare. An attempt was made to reduce 
this difficulty still further by the use of a glaze made from 
melted mineral albite, which was appreciably soft at tempera- 
tures of 1100° but which appeared to prevent the sublimation 
of iridium so long as the coating remained continuous. The 
viscous material, “however, showed a persistent tendency to 
gather together into globules, leaving bare spots on the bulb 
which were not wet by the elaze, so that this protection was 
not complete. Porcelain insulating tubes open at the end 
afford little or no protection. We were accordingly driven to 
the conclusion that for the higher temperatures iridium must 
be banished from the furnace completely before consistent 
observations can be obtained. This is the chief reason why 


* Day and Allen, loc. cit. p. 26. 


420 A. L. Day and J. Kh. Clement—Gas Thermometer. 


the present series of observations was not extended beyond 
1200°. Observations above this temperature will therefore be 
made the subject of a subsequent paper in which a bulb con- 
taining no ridium will be substituted for the one described 
here. 

Up to 1200° our precautions were sufficient to prevent 
serious contamination of the elements and the error due to 
such contamination as was unavoidable has been eliminated 
by frequent calibrations of the three elements throughout 
the observations, either by comparison with standard elements 
known to be free from iridium contamination, or with melting 
point determinations of standard metals. Toward the close of 
the series, in order to establish absolute proof that the readings 
were not encumbered with systematic errors, however small, 
from this cause, an independent observation was made in the 
following way: The element at the middle of the bulb was 
replaced by a freshly calibrated new element known to be in 
perfect condition. After an ice-point determination and with 
all the precautions above described, the furnace was heated 
directly and as rapidly as possible to 1200°, where a single 
observation was made and the furnace immediately cooled down 
again. The new element was then removed from the furnace 
and recalibrated in order to establish beyond question the fact 
that it had suffered no contamination whatever during the short 
run. This independent determination, in which it was defi- 
nitely proved that iridium contamination played no part, served 
to establish the absolute correctness of the high temperature 
observations in so far as the error from this most. persistent 
source was concerned. | 

The Gas.—Nitrogen was prepared by dropping a solution 
of 200 grams of sodium nitrite dissolved in 250 grams of water 
into a warm solution containing 300 grams of ammonium sul- 
phate and 200 of potassium chromate in 600 grams of water. 
The gas was then passed through a mixture of potassium bichro- 
mate and sulphuric acid and stored over water. Before intro- 
ducing this nitrogen into the gas thermometer, it ‘was 
purified by passing it in succession through calcium chloride, 
hot copper gauze, potassium bichromate in sulphuric acid, 
two bottles containing potassium pyrogallate solution, sulphuric 
acid, calcium chloride and phosphorus pentoxide. 

No reason has yet arisen in any of the experiments with 
nitrogen for suspecting limitations of any kind due to the gas. 
It has shown no tendency to react with the platinum bulb or 
to pass through its wall or to dissociate at any temperature to 
which it has yet been carried in gas thermometry. [urther- 
more Buckingham * has shown by ingenious methods of com- 


* EK, Buckingham, loc. cit. 


A. L. Day and J. K. Clement— Gas Thermometer. 421 


parison that the derivation of the Kelvin thermodynamic scale 
from the expansion of nitrogen is probably not encnmbered with 
any error of sufficient magnitude to require consideration when 
compared with the errors and corrections inherent in the 
experimental measurements. From the standpoint of the 
underlying theory of the instrument and the interpretation of 
its results in terms of the thermodynamic scale, a new and 
extended experimental study of the Joule- Thomson effect is 
very greatly to be desired, but there is no reason for apprehen- 
sion in the application of, existing data, imperfect and limited 
as they are. Experimental confirmation of this is contained in 
the recent work of Jaquerod and Perrot in which the expansion 
of five different gases (nitrogen, air, CO, CO,, O,) between 0° 
and 1067° was studied in the same bulb under identical. experi- 
mental conditions. Tbe maximum difference which occnrred 
in any of their measurements was only ‘4 of a degree, which 
is easily within the limits of error of their apparatus. 

The Bulb.—The question of a suitable bulb to contain the 
expanding gas has been and is to-day one of the most serious 
which gas thermometry confronts. The first experiments 
(Prinsep) were made with a bulb of gold, which was soon 
abandoned because of its low melting point. Following this, 
platinum was employed (Pouillet), but here a difficulty was 
encountered which eventually caused its abandonment in favor 
of porcelain on account of its supposed porosity (Deville and 
Troost, Becquerel).. Iodine vapor had been used in the experi- 
ments of Deville and Troost as the expanding gas and very 
‘high values of several temperature constants in the region of 
1000° had been obtained and quite generally accepted, while 
the much lower values obtained with a platinum bulb with air 
were discredited for the time. These high values were sub- 
sequently shown by Victor Meyer to be due to the dissociation 
of the iodine, but the controversy resulted in the unfortunate 
(as it turned out) substitution of porcelain for metal bulbs, a 
step which was not retrieved for thirty-six years. The porce- 
lain bulb without glaze is porous ; with a glaze it is a chemically 
undefined mineral mixture which not only softens below 1200° 
with more or less change of volume, but also gives out gas 
(either original or previously absorbed), so that the porcelain 
gas thermometer, as it is commonly called, never returned to 
its original zero after heating to high temperatures.* The 
uncertainty in the zero which arises through the use of the 
porcelain bulb causes an error of the order of 5° at 1000°, which 
is practically impossible of satisfactory correction. 

The return to metal bulbs is due to Prof. Holborn of the 
Reichsanstalt, who has successfully used a platinum bulb (con- 


* Holborn and Day, 1899, loc. cit. 


Am. Jour. Sct.—FourTH Series, Vout. XX VI, No. 155.—NovemeBer, 1908. 
30 


492 A. L. Day and J. &. Clement—Gas Thermometer. 


taining 20 per cent of iridium) of 200° capacity with nitrogen 
as the expanding gas up to 1600° without discovering any 
irregularity in its behavior. The porcelain bulb has therefore 
probably disappeared permanently from gas thermometry. 

Whether or not some other platinum metal than iridium will 
not prove preferable with which to give the necessary stiffness 
to the platinum is a question for the future to decide. It isa 
matter of great difficulty and some uncertainty te make trust- 
worthy measurements of temperatures above 1000° with 
platinum thermoelements in the presence of iridium (see para- 
graph on thermoelectric measurements preceding), even when 
the iridium is present only in a low percentage (005) alloy 
with platinum. 

Parenthetically, it may be remarked that the platinum eruci- 
bles and other ware as made up for laboratory use in this 
country are usually stiffened with about 2 per cent of iridium, 
a quantity amply sufficient to contaminate thermoelements if 
exposed in the furnace with it to temperatures above 900°. 

The Measurements.—The method of procedure with the 
system in adjustment for observation was then substantially as 
follows : 

With the body of the furnace lowered so as to expose the 
bulb, a pail of suitable size was brought up about the latter 
and filled with.distilled water and finely divided ice in such a 
way as to enclose the bulb and so much of the capillary as was 
included within the furnace when heated. Several readings 
of the ice point were then made on the manometer, together 
with simultaneous readings of one or both barometers., To: 
control the expansion coefficient of the gas, these readings 
were occasionally followed by a second reading at the temper- 
ature of boiling water in which the ice pail was replaced by a 
double-chambered boiling-point apparatus of standard type. 
In general, however, it may be said that the expansion coefii- 
cient of pure nitrogen has already been so carefully determined 
by Chappuis and others that this observation is superfluous, par- 
ticularly as the sensitiveness obtainable in a bulb of a size 
suitable for long ranges of temperature is not sufficient to admit 
of a determination comparable with theirs. 

After the ice point had been determined, therefore, the gen- 
eral procedure was to arrange the three thermoelements in posi- 
tion at the top, middle and bottom of the bulb (fig. 1), to close up 
the furnace gas-tight and to proceed with the heating. Before 
turning on the current, however, it was first necessary to 
exhaust the bomb and to replace the air with a nitrogen atmos- 
phere, the nitrogen being supplied from a separate bomb under 
high pressure. The nitrogen for this purpose was made in 
large quantities in the laboratory by the method of Hutton 


A. L. Day and J. K. Clement—Gas Thermometer. 4238 


and Petavel,* and pumped into bombs at a pressure of about 
1,000 pounds per square inch. One of these bombs could be 
readily connected with the furnace through appropriate port- 
able connections whenever desired. A pressure gage con- 
necting with the inside of the furnace bomb enabled the 
pressure within the bomb and outside the bulb to be read at 
any time. If the advance in pressure outside the bulb did not 
proceed as rapidly as that within, additional nitrogen could be 
admitted as required. In general, it can be said of the oper- 
ation of this arrangement for the adjustment of pressure within 
and without the bulb, that if the furnace is perfectly tight the 
two pressures advance together and are never very far apart. 
Attention to this detail is therefore not burdensome unless the 
bomb is leaking, in which ¢gase the losses must be supplied by 
the addition of small quantities of nitrogen from time to time. 
An effort was made to keep the pressure outside the bulb 
within one-half pound of the inside pressure as read on the 
manometer. 

After the current had brought the temperature to the point 
where it was proposed to make a reading, about three-quarters 
of an hour was required to adjust the three resistance coils so as 
to produce a permanently uniform temperature along the bulb, 
which limited the number of temperature readings in one 
working day to six or seven. It was therefore our habit to 
make readings, at 50° or 100° intervals, so as to cover a consid- 
erable range of temperatures each day. On following days 
intermediate temperatures were selected in such a way that the 
whole field between 250° and 1200° would eventually be can- 
vassed in steps of 25°. In order to provide a sufficiently rigid 
control of the conditions within the bulb, however, each day’s 
readings began with a new determination of the ice point. 

It is interesting to note in passing that the variation of the 
ice point after heating, which was a conspicuous feature in all 
gas thermometric work previous to 1900, has now substan- 
tially disappeared with the return to the platinum bulb. Our 
ice points (column 3, Table II) from day to day showed no 
disagreement of greater magnitude than that produced by 
the somewhat irregular contraction of the bulb due to slight 
variations in. the rate of cooling, to which attention has been 
explicitly called in the chapter on the expansion coefticient of 
platin-iridium (p. 436). 

When the temperature had become constant over the entire | 
length of the bulb, one observer took his position at the tele- 
scope of the manometer and the other at the galvanometer, 
and simultaneous readings were made of the group of ther- 


* Hutton and Petavel, Preparation and Compression of Pure Gases for 
Experimental Work, Journ. Soc. Chem. Ind., xxiii, Feb. 15, 1904. 


494 A. L. Day and J. K. Clement—Gas Thermometer. 


moelements and of the pressure within the bulb. Between 
each two pressure readings a reading of the barometer was 
made by the observer at the gas thermometer, the barometer 
having been arranged in a conveniently accessible position for 
that purpose. All the readings were arranged in symmetrical 
groups in such a way that the time rate of change of temper- 
ature, if any, would fall out in the arithmetical mean of the 
pressures and temperatures at the beginning and end of the 
series. At the close of this set of observations, readings were 
made of the three thermometers which gave the temperature 
of the mercury column of the manometer. The temperature 
of the unheated space requires no Separate determination in 
view of the fact that a change of 5°in the room temperature 
does not affect it by an appreciable amount. The average 
room temperature was therefore sutliciently accurate to deter- 
mine the correction for the unheated space. 

Following such a series, the temperature was increased by 
the desired interval and the same operation gone through with 
again. Constant attention was of course required in the mean- 
while to see that, in increasing the temperature of the furnace, 
and therefore of the bulb, the eee es inside and outside 
the bulb did not get too far apart. The same was true of the 
cooling at the close of the series. 

Before the bulb was connected up with the manometer for 
the final filling, readings were made of the position of the 
fixed point which defines the constant volume upon the seale. 
This was done by letting in mereury with both tubes open 
and reading the mercury level in the long tube when the men- 
iscus in the short tube was raised so as to be just tangent to 
the fixed point. The following readings were obtained: 


PosiTIon oF ‘‘ FixED POINT” ON THE SCALE. 
May 9, 1906 
Temperature of Seale 


—— —_——_-_- + 
Scale reading Lower end Upper end 
em Thermometer No. 15 Thermometer No. 11 
69°049 29h POS 
‘050 22° 23°0 
“051 229 ears | 
"053 rod, 23°4 
"054 22°6 23°6 
"055 226 PSF 
"054 22°6 DES ey 
Mean 69°0523 25°56 23°38 
Correction —:‘001 —0°3 0°45 
69°051 22°26 22°88 


69°051 22°57" 


A. L. Day and J. K. Clement—Gas Thermometer. 425 


On account of the unequal expansion coefficients of the 
(brass) scale, and of the (glass) manometer tube, in which the 
fixed point is mounted, the elevation of the fixed point with 
respect to the scale will change with temperature. The vari- 
ation amounts to — 00009 per degree rise in temperature. 

Volume of Bulb.—The volume “of the bulb, incleding the 
stem, was determined by weighing with water at the beginning 
of these experiments and again at their conclusion with the 
following results : 


Volume of bulb and stem, Sept. 1905__._..._-- 195 7oee 
se webategne (csc cryy 4 SS Ov peta NG (6 fel bean ae ae 195°66°° 


Since V, enters into the computation of temperature only as 
a part of the correction factor for the unheated space, and as 
this total correction is never more than 5°, it is obvious that 
the absolute volume of the bulb is not, of itself, an important 
factor in the problem. On the other hand, the correction for 
the expansion of the bulb with the temperature amounts to 45° 
at 1100°, and is the most important correction factor which 
requires to be determined. An error of 1 per cent in the 
determination of this constant (8) produces an error of 0°5° 
ats LOO". 

Expansion Coefficient of the Bulb.*—The determination of 
the expansion coeflicient of the bulb did not prove to be the 
perfunctory operation -which had been anticipated, but devel- 
oped into an independent research of somewhat exasperating 
character, covering several months. 

There are two methods which might be pursued to obtain this 
constant. It is theoretically possible to determine the actual 
volume expansion of the gas thermometer bulb in position in 
the furnace, but an effort to carry it out experimentally a few 
years ago developed serious difficulties where the range of tem- 
perature is so great and the accuracy required so considerable. 
We therefore preferred to obtain a bar made from the same 
material as the bulb, and to determine its linear expansion 
under conditions which were under more perfect control. 

In principle, the method of procedure is the one used at the 
Reichsanstalt. A bar of platm-iridium 5™" in diameter and 
slightly more than 25 in length was prepared for the 
purpose and heated in a tube furnace in which the temper- 
ature could be maintained nearly uniform from one end of the 
bar to the other and conveniently regulated upto 1000° or 
more. The ends of the bar were filed flat for a distance of 6™™ 
and upon these flat surfaces millimeter divisions were ruled 
with a dividing engine. The balance of the apparatus con- 
sisted of a pair of micrometer telescopes mounted so as to 


*By A. L. Day and R. B. Sosman. 


496 A. L. Day and J. K. Clement—Gas Thermometer. 


observe these divisions and also to maintain a constant distance 
between the fixed cross-hairs from beginning to end of the 
experiment. Heating the bar then served to move the ruled 
lines past the fixed cross-hairs of the telescopes and the amount 
of the.displacement was measured for any desired temperature. 


' Fic. 4. N) 


Fic. 4. Section through furnace showing bar. thermoelements (E,E) and 
microscopes in position. A section through the arrow is shown in fig. 5. 


The aggregate expansion of a 25°" bar over the interval from 
0° to 1000° is about 2°5"". The telescope micrometers as they 
were focused for the measurements gave about 450 divisions 
(each about 2™) of the drum for one millimeter on the bar, 
and in the individual readings differences of -2 or °3 of a divi- 
sion were readily distinguishable. It was therefore easily 
possible to make very accurate measurements of the expansion 
of such a bar by direct observation without the use of a con- 
tact lever or any multiplying device whatsoever. 

The essential features of the apparatus can be partly seen 
from the figures and partly require some description. The 
furnace was erected on a separate stand quite independent of 
the measuring apparatus. It consisted of a narrow tube 
wound with a heating coil and containing, opposite the ends of 
the bar, two small openings through which the divisions could 
be seen. The inside diameter of the tube was about 2°, and 


A. L. Day and J. K. Clement—Gas Thermometer. 427 


the side openings, narrow slits about 3°" in width by 10™™ long. 
The tube and its heating coil extended some 10™ beyond the 
ends of the bar and the wire was wound somewhat more 
closely at the ends than in the middle to counteract the cooling 
effect of the end and side openings. In this way a reasonably 
uniform distribution of temperature along the bar was secured. 

The first furnace tube was of porcelain wound with nickel 
wire 1™™ in diameter, the separate turns being insulated from 


Fie. 5. A section through the furnace (A) at one of the openings showing 
method of illumination by 45° plane glass plate (a). The bar and thermo- 
element appear in position though not well shown by this section. 


each other with a magnesite cement which is sufficiently 
refractory and conducts but little at any temperature which 
the nickel wire can withstand. Thus arranged, the heating 
coil was mounted horizontally in a much larger tube (8° diam- 
eter) of porcelain and the space between filled with dry 
calcined magnesia of good insulating quality. The whole was 
water-jacketed throughout in order to prevent any heat 
from the furnace from entering the optical system and disturb- 
ing the fixed distance between the micrometers upon which 
the accuracy of the measurement absolutely depends. Both 
the insulating material and the water jacket were provided with 
small openings corresponding to the slits in the furnace tube 
so that the bar could be illuminated and observed from without. 

The measuring portion of the apparatus was entirely separate 
from the furnace and consisted.of two telescopes, mounted upon 


428 A. L. Day and J. K. Clement—Gas Thermometer. 


upright brass tubes firmly secured in position upon massive brass 
carriages which slid freely upon horizontal steel guide bars some 
4°™™ in diameter and ground true. The two carriages were then 
connected by an invar metal bar (fig. 4) to which they were 
stoutly and permanently clamped. The whole system was 
then free to move upon its guides, but the relative position of 
the telescopes was fixed. The object of this arrangement was 
obviously to secure a constant distance between the telescopes, 
in spite of slight changes in the temperature of the system due 
to the temperature of the room or the heat from the observer’s 
body, whatever the relative expansion of the various parts of 
the apparatus. After a good many observations had been 
made, it was found that the upright brass tubes supporting the 
telescopes upon their carriages were not uniformly affected by 
the heat from the body of the observer. They did not there- 
fore expand uniformly and parallel to each other, but tended 
to buckle very slightly during each series of observations. 
This was subsequently corrected by a second invar bar above 
the telescopes which in combination with the first formed a 
rugged rectangular system which preserved the cross-hair dis- 
tance without change throughout long series of observations. 

In mounting the furnace for observation, the side openings 
which gave access to the scale divisions were directed down-- 
ward in order to.reduce to a minimum the convection currents 
of air which endanger the constancy of the temperature within. 
The openings were also made as small as possible for-the same 
reason. It therefore became something of a problem to bring 
in light enough to illuminate the scale divisions and at the 
same time to make observations of the change in length with 
the temperature. The device adopted was this: In the opti- 
cal axes of the telescopes and some 5 or 6™ beyond the 
objective, small total reflecting prisms were mounted upon the 
extended telescope tubes in such a way as to deflect the line of 
sight at right angles and upward into the furnace. Above 
these prisms and between them and the furnace (see fig. 5), 
windows of plane optical glass were set at 45° in such a way 
that they served to reflect the light from an incandescent lamp 
upward from their outer surfaces without materially inter- 
rupting the line of observation thpone> the telescope and 
total reflecting prism. By this device the path of the illumi- 
nating light was the same as the path of the reflected light 
which reached the observer, which served to give plenty of 
iliumination for the scale without increasing the size ot the 
openings beyond what was required to see the actual expansion 
and to measure it. 

The illumination was provided by a singie incandescent 
lamp of 100 candle pow er with a spiral filament of stock type 


A. L. Day and J. K. Clement—Gas Thermometer. 429 


giving an intense and concentrated illumination. It was 


mounted behind the furnace some 20° distant from the open- 
ings, and was so screened that its heat did not reach the 


Fie. 6. 


Fic. 6. The expansion apparatus. A photograph of a furnace and acces- 
sory apparatus for the determination of expansion coefficients over long 
ranges of temperature. The illustration represents a later form of appara- 
tus than that described in.the text. The difference lies mainly in the 
increased length; the present furnace is arranged to take bars 50°" long 
instead of 25™ as described. 


optical parts of the apparatus save in the two beams which 
enter the furnace for the illumination of the bar. 

The temperature of the bar was determined at first with 
one thermoelement and afterward with two, which entered the 
furnace tube from opposite ends in such a way that their hot 


430 ALL. Day and J. K. Clement—Gas Thermometer. 


junctions could be bound together and moved freely along the _ 
bar and in contact with it, in order to give a double reading of 
the temperature at any point desired. In this way we obtained 
the actual distribution of temperature along the bar corre- 
sponding to each determination of its length. 

To complete the system, a standard brass bar was prepared 
of the same size and shape as .the platin-iridium bar under 
investigation, but with silver surfaces let in at the ends to 
carry the divisions. This bar was compared at 20° C. with 
the standards of length at the Bureau of Standards, and 
served to establish the absolute distance separating the cross- 
hairs before and after each set of observations. 

The method of procedure was now substantially as follows: 
The standard brass bar was placed in position in the furnace at 
the temperature of the room. All the necessary adjustments 
to secure good illumination, to bring the cross-hairs parallel to 
the scale divisions, and to bring the lines into sharp focus, 
were then made once for all, and these adjustments were never 
again disturbed until the series was completed. The field of 
the microscopes included 5™ of the bar, but only the three 
scale divisions bounding the 2™™ nearest to the fixed cross-hair 
were used. Toward the close of the investigation, for an 
important reason which will presently appear, only the two 
bounding divisions of the single millimeter which included the 
fixed cross-hair were read and all the observations which had 
been made outside this limited region were rejected. Readings 
were made from left to right in each microscope and then 
repeated in the reverse direction to obviate errors from the 
micrometer screw. The temperature for this measurement 
was determined with a glass thermometer thrust into one end 
of the furnace tube adjacent to the bar and read before and 
after the series of micrometer readings. This observation 
served to establish in absolute measure the distance apart of 
the fixed cross-hairs of the microscopes. The brass bar was 
then removed and the platin-ridium bar corresponding to the 
gas thermometer bulb inserted in its place in the same relative 
position. It is necessary here again to emphasize the fact that 
all further adjustment must be made with the bar and not with 
the optical parts of the apparatus. 

Having brought the bar into exactly the same position with 
respect to the telescopes which the brass bar previously occu- 
pied, and having introduced the thermoelements in such a way 
that their hot junctions were free to travel along the bar from 
end to end witbout disturbing it, a second series of observa- 
tions at the temperature of the room was made in the same 
way as before. This yields the absolute length of the bar at 
room temperature in terms of the standard brass bar. dhe 
furnace is then ready for heating to the temperatures desired. 


A. L. Day and J. K. Clement— Gas Thermometer. 4381 


In the determination of the high temperature scale carried 
out at the Reichsanstalt in 1900, four observations of the 
expansion of the. bulb material (250°, 500°, 750° and 1000°) 
were deemed sufficient, and it was not thought necessary in onr 
earlier observations to increase this number materially. We 
therefore began with a 200° interval. After the observation 
at the temperature of the room, the bar was accordingly heated 
to 200° C. and sufficient time (about 30 minutes) allowed for 
the temperature to become constant throughout the furnace, 
after which a temperature reading was made at the middle of 
the bar with each element. Observations of length were then 
made in the same order as before upon the pair of lines adjacent 
to the fixed cross-hair in each of the microscopes, followed by 
a second temperature reading at the middle of the bar. After 
these observations of length and before any change was made 
in the temperature, nine consecutive pairs of observations were 
made of the temperature distribution along the bar, first at the 
center, then on the left section at 5,10 and 12°" out from 
the middle, then the center repeated; then upon the right 
section with similar intervals, and again the center—all with 
both elements. By this means an accurate measurement of the 
temperature along the bar corresponding to the length measure- 
ment just completed was obtained. The whole procedure was 
then repeated at temperatures of 400, 600, 800 and 1000° C.,* 
after which the furnace was allowed to cool over night and the 
length of the bar at the temperature of the room again deter- 
mined. Immediately following this an observation of the 
_ brass bar was made in order to establish the fact that the dis- 
tance separating the cross-hairs had not been accidentally dis- 
turbed by the manipulation of the furnace during heating. 

At 800° and 1000° the bar is self-luminous to a sufficient 
extent to enable measurements to be readily made without out- 
side light, but it was deemed advisable to use the outside light 
in the same way at these temperatures also. In passing from 
outside to inside illumination, the lines are at first dark on a 
bright ground, and then bright on a dark ground, a change to 
which the eye accustoms itself only with considerable difficulty. 
The measurements were therefore much more uniform when 
outside light was used throughout. 

The measurements of the temperature at once encountered 
the difficulty that the exposure of the thermoelement in the 
presence of iridium at a temperature of 1000° contaminates it 
by an amount sufficient to cause a small but cumulative error. 
This exposure was necessary with the apparatus as we had 

* Subsequently, when we had reason to suspect an irregularity in the rate 


of expansion, these observations were repeated every hundred degrees and 
then every fifty degrees in the region between 600° and 1600°. 


432 A. L. Day and J. Kh. Clement—Gas Thermometer. 


arranged it, and there was therefore nothing to do but to make 
the time of the exposure as short as possible, and by the use 
of two elements fastened together and extending out of the 
furnace at opposite ends, to so arrange the conditions that any 
contamination, if sufficient to affect the temperature, would 
become immediately apparent. As W. P. White of this 
laboratory has shown in a recent paper,* the most critical 
portion of a thermoelement is not the portion along which the 
temperature is constant, but the region where the element 
passes from one temperature to another. In our furnace, for 
example, the region of exposure to constant temperature could 
give rise to no error of reading however much the element 
might be contaminated in that region, but if a contaminated 
portion of the element were at any time to come into the 
region lying between the end of the bar and the outside of the 
furnace an immediate difference in its reading should become 
evident. It was therefore arranged that the junctions of two 
elements should be bound together so as to record the temper- 
ature of the same point within the furnace and that whenever 
this combination of two elements was moved toward one end 
of the bar or the other, that a greater length of one of the 
elements should be exposed within the furnace than of the 
other. If there is contamination a difference in reading 
between the two elements will be immediately conspicuous. In 
the earlier observations comprising this investigation, only one 
element was used, and by way of control at the close of a long 
series of observations a second element was introduced in the 
manner indicated above. It then became immediately evident 
that the first element had become contaminated and that the 
observations made with it were affected to a degree which 
could not be established after the observations themselves were 
over, and which therefore necessitated the rejection of several 
entire series. This misfortune may serve to emphasize the 
necessity of using more than one thermoelement in all cases 
where it 1s possible to do so. 

Three other dithiculties were met with which proved to be 
sources of considerable inconvenience, and which serve in 
greater or less degree to place limits upon the accuracy attain- 
able in this particular apparatus, The first was the temper- 
ature gradient along the bar, of which mention has already 
been made. Earlier observers have sometimes been content 
in similar cases to heat a bar with the electric furnace and to 
make their measurements upon cold projecting ends, that is, 
under conditions such that the actual temperature along the 
bar varies from the temperature of the room to a maximum 
near the middle of the bar. The resulting temperature to 


* Walter P. White, Phys. Rev., xxvi, p. 535, 1908. 


A. L. Day and J. K. Clement—Gas Thermometer. 483 


which a given measured length is then referred, is an integral 
of a temperature range which varies all the way from that of 
the room to some point considerably higher than that for which 
the length measurement is recorded. This situation seems 
to us to “comport badly with the accuracy otherwise attainable 
in measurements of this kind, if not to violate fundamental 
definitions. Unless the expansion coefficient can be treated as 
linear, such a determination is obviously only an approxima- 
tion. Furthermore there is ample precedent for anticipating 
inversions in an alloy of this character such that the expansion 
coefficient of the material below the inversion temperature 
would differ considerably from that above it. An integration, 
therefore, in which the temperature range is large may well 
overlap two physical states 1m such a way that the length 
measurement loses all significance. We have not been able to 
establish the fact that such an Inversion exists in the 10 per 
cent platin-iridium alloy within the temperature range over 
which these measurements were made, although there is 
an obyious break in the continuity of the expansion, of small 
magnitude, which recurs with some persistence, as can be seen 
from the tables which follow (pp. 487 et seq.). 

Supposing such an inversion to exist, it would of course fol- 
low that the expansion would be a discontinuons function of 
the temperature, a separate expansion coefficient would require 
to be determined above and below this point, and the two 
would not bear any necessary relation to each other. If such 

a situation exists in the present bar, the difference is so small 
as to be negligible for our present purpose, but the plain indi- 
cation of an irregularity led us to appreciate the necessity of 
maintaining the bar as ‘nearly constant in temperature as pos- 
sible during the length measurements in order to enable us to 
interpret the measurements intelligently. 

The problem of accomplishing this result gave us consider- 
able anxiety. As has been stated above, the scheme of making 
optical measurements directly upon the bar without multiply- 
ing device of any kind necessarily involves an opening in the 
furnace coil opposite each end of the bar, and a consequent 
cooling of that portion of the bar which is ‘opposite the open- 
ing. The amount of this cooling, which is greatest at the 
highest temperatures, reached a value of about 4 per cent in 
the first furnace coil which we wound. The temperature dis- 
tribution along the bar is measurable with any accuracy desired 
by moving the thermoelements about, or its effective average 
can be determined by direct integration with a platinum resist- 
ance thermometer of equal length, stretched parallel to the bar. 
We chose the former method on the ground that it yielded 
more information, and then sought in addition to diminish the 


434 A. L. Day and J. K. Clement—Gas Thermometer. 


irregularity as much as possible for the reason given above. 
Accordingly, another furnace coil was wound with the turns 
closer together near the openings. This changed the temper- 
ature ovadient considerably without materially improving it | 
(see Furnace II seq. ), after which a third coil was prepared 
with still closer windings, which proved to be considerably 
overcompensated and was rejected. In all, we made five sep- 
arate trials of this kind, in the last two of which (Furnaces IIT 
and IV ) a thick- walled iron tube was substituted for the por- 
celain furnace tube in the hope of gaining increased uniform- 
ity of temperature through the increased heat conductivity 
of the tube itself. This arrangement succeeded better, but 
we found it impossible to so arrange a winding that. the 
temperature opposite the openings was uniform with that 
at the middle of the tube for all temperatures between 0 and 
1000°.* A winding which gave good results at the lower 
temperatures gave insufficient compensation at the higher ones. 
The obvious possibility of reaching a uniform distribution by 
subdividing the coil into sections in each of which the current 
could be independently varied was not tried on account of the 
cumbersome manipulation required, and in part also because 
the results which we obtained with considerable differences in 
the gradient appeared to agree very well among themselves. 

The temperature carried out in the tables in each case repre- 
sents the integral of the nine pairs of readings described above. 
The actual error which enters into an observation from the 
variation in temperature opposite the openings is therefore the 
error in establishing this integral, which can hardly be greater 
than 1° C. or 1 per cent. | 

It will probably occur to other experimenters, as it did to us, 
that this difficulty with the exposed ends of the bar is due in 
part to the unavoidable air currents circulating through the 
small openings, and that these ought to be checked by the 
introduction of windows. We made two attempts to reach 
the difficulty in this way, first using quartz windows set in the 
opening of the furnace tube itself and therefore heated with 
the tube; and second, by the use of glass windows set in the 
water jacket and therefore outside of the heated zone. The 
quartz windows behaved very well until high temperatures were 
reached, when they become displaced by the unequal expan- — 
sions in the apparatus, thereby causing displacements in the 
apparent position of the lines of the scale.. When the windows 

* A considerable part of the difficulty in correcting the irregular furnace 
temperature was due to the instability of nickel wire at the higher temper- 
atures. The oxidation is so rapid that a favorable arrangement of the wind- 
ings, when obtained, does not give uniform results for more than one or two 


series of observations. It is our purpose to abandon it in favor of a nickel- 
chromium alloy or pure platinum. 


yaar 


A. L. Duy and J. K. Clement—Gas Thermometer. 485 


were removed to the colder parts of the furnace in order to 
avoid this displacement, sufficient water vapor condensed upon 
them from within to obscure the field, so that the window 
scheme had to be entirely abandoned. 

The second considerable difficulty to be encountered was due 
to the effect of the outside illumination of the divisions of the 
bar in a field of rather high power (about 25 diameters). 
Consider the bar to be illuminated by a beam of light from a 
fixed source (which remains constant in position while the bar 
expands) and the light received through the telescope into the 
eye to be reflected from the polished parts of the bar surface 
between the rulings. For reasons which appear in the adja- 
cent figure (fig. 7), this reflected light does not show the lines to 
be equally* displaced after expansion. The reason for this is 


Hires 7. 


Fic. 7. Showing how the lines appeared displaced after expansion. Ac- 
tual expansion, m to point indicated by the arrow. Apparent expansion, m 
to n. 


plain after a brief consideration. If lines are ruled with a 
sharp tool upon soft platinum metal which is afterward polished 
to remove the burr left by the cutting tool, the effect is to 
round off the two edges of each cut to a greater or less extent, 
and thereby to present approximately cylindrical bounding sur- 
faces to the incident light. The apparent boundary of the line 
will then be defined by the reflection of this light from the 
cylindrical surface into the telescope. Now, if this cylinder 
be moved laterally in the direction produced by the expansion, 
the light will be reflected from a different point on the 


*The small expansions of the millimeter sections themselves have been 
taken into account, although not explicitly mentioned in this discussion. 


436 A. L. Day and J. K. Clement—Gas Thermometer. 


eylinder and will therefore show the line in a somewhat differ- 
ent apparent position from that which would be produced by 
the expansion alone. The drawing is purposely exaggerated 
to show exactly the character of this optical error. It was our 
habit in beginning these observations to select three appropri- 
ate lines upon each end of the bar, and to make all the meas- 
urements on these, whereupon it was found by a careful exam 
ination of the results that the displacement of the three lines 
after expansion differed systematically by a measurable amount 
and in a manner which could not be accounted for by the 
movement of the bar. This difference was very puzzling for 
a long time, but was finally traced to the source described, and 
this inference verified by actually moving the bar about in 
the field in various ways without changing the temperature. 
The consequence of this discovery was to compel the rejection 
of all measurements made upon lines other than those’ imme- 
diately adjacent to the fixed cross-hair in the center of the field. 
The number of observations at each end was therefore reduced 
to two, but the agreement of the results was very considerably 
increased thereby. 

The third and most serious dificulty of all amounts to an 
essential limitation of the material itself and is therefore not 
dependent upon the method of measurement. It is the failure 
of the bar to return to its initial length after heating. 

In this particular bar, 25°" in length, we actually found dit- 
ferences between the lengths before and after heating of 
the order of magnitude of -02™", which varied from one series 
of experiments to another according as the bar happened to 
be cooled rapidly or slowly. This quantity is some fifty times 
larger than the smallest magnitude we could measure, and 
inasmuch as it depends only upon measurements at the tem- 
perature of the room, is readily accessible. It is of course 
immediately obvious that this constitutes a limitation upon 
the accuracy of gas-thermometric measurements in a bulb of 
this material, but in this very particular the behavior of platin- 
iridium is enormously more favorable than that of any of the 
other materials (porcelain, fused silica) which have yet been 
applied to this purpose. Although this limitation of platin- 
iridium would not therefore alone be sufficient to deprive it 
of continued usefulness for the gas-thermometer, yet when 
combined with the contaminating action of the iridium which 
distils out of the alloy at all temperatures above 900° in sutf- 
ficient quantities to eventually destroy the accuracy of the 
thermoelement, it has led us to abandon the iridium alloy for 
the future, and to substitute an alloy of rhodium. 

This study of the irregularities present or possible in the 
expansion of the bulb was pursued much more persistently 
than is usual in an investigation which is but incidental to a 


A. L. Day and J. K. Clement—Gas Thermometer. 487. 


much larger one, on account of the unexpected values obtained. 
The expansion of pure platinum as determined by Holborn 
and Day* is given by the equation, . 


A = (8868 ¢ + 1:329 7) 107° 


while that of platinum, containing 20 per cent iridium, made 
in the same furnace at the same time, gave 


A= (8198 ¢ + 1°418 ¢) 10~°. 


We had expected, as Holborn and Day assumed in their cal- 
culations in 1900, that the expansion of the 10 per cent alloy 
ought to fall approximately between the two. When it there- 
fore became apparent that our observations were leading to a 
value for the 10 per cent alloy which was of the same order 
of magnitude as that hitherto found for pure platinum, we 
were for a long time quite unwilling to accept the result. 

After the close scrutiny of the apparatus and its limitations. 
described above, all of which, either singly or in combination, 

appeared totally inadequate to account for the unexpected 
expansion coefficient obtained, there remained the single pos- 
sibility that some confusion had arisen in the preparation of 
the bar; but Doctor Hereeus, who made the bar, would not 
admit this possibility. Even then, it was deemed wise to 
make a chemical analysis of the bar itself, and this was done 
by E. T. Allen of this laboratory, with the result that the 
iridium content was found to be 10°6 per cent. There appears 
therefore no further alternative but to accept the irregular 
variation of the expansion with the percentage composition as 
characteristic of platin-iridium, following the well-known 
example of the iron-nickel alloys. 

The observations follow: 


In Furnace I. 


Temperature Distribution along the Bar. 


Left Middle Right 
(Corrected 
12cm 1(Qjcm jem Temperature) jem 10cm 12cm 
+10° | +11° | + 7° Heir — 4° | —18° | —15° 
+12 +13 + 7 511°2 — 2 —15 —24 
+10 +23 +13 700° — 5 —21 — 30 
+28 +33 +17 1044°1 —11 —3l —46 


* On the Expansion of Certain Metals at High Temperature, this Journal 
(4), xi, p. 574, 1901. 


Am, Jour. aE Se ie SERIES, VoL. XXVI, No. 155.—Novemper, 1908 
1 


438 A. L. Day and J. K. Clement—Gas Thermometer. 


Expansion. 
: Corrected A/L 
Date na 
Temperature Observed Calculated eogeee < 
Dees sO, 190722) se 28-7 a. 002635 002661 — 26 
Lhe 004871 "004879 — 8 
712°9 007051 "006994 +57 
Dee. SOO W ewe 700:0 ‘006878 006855 +23 
866°6 008653 "008677 — 24 
Jan. DO OSE a 504:°0 "004812 ‘004805 + 4 
504°4 004813 004810 + 3 
690°0 °006763 ‘006748 +15 
689°4 "006755 "006742 +13 
856°5 008600 ‘008565 “+35 
856°4 008610 008564 +46 
1044-1] "010616 010699 — 83 
1043°8 "010635 "010695 —60 
X _ total expansion Equation used for the “calculated” 
IL. initial length expansions, A=(8869°5¢ + 1°3192¢°)10~° 
In Furnace II. 
Temperature Distribution along the Bar. 
Left Middle Right 
(Corrected 
12m 10cm Hem | Temperature) jem 10cm 12cm 
ZED es Fo 0° 294:0° —4° | —12° | —27° 
DS) — 6 — 2g 392°0 —6 —20 —4] 
—28 — 9 — 4 491°0 19 —17 —33 
— 30 —13 — 5 592°5 0) —10 — 30 
— 34 —15 — 5 695:°0 +4 — 3 == 27, 
855 | 17) —97 | -795°0 EB) ee a at 
— 52 —21 — 9 | 894:0 +9 + 6 —12 
—5l —2]1 —10 994:°0 +8 + 8 —14 


*Tnasmuch as the expansion-cofficient which is here being determined 
itself enters into the determination of the temperature, the two quantities 
are not independently variable. The temperatures given above are, there- 
fore, based upon tentatively assumed constants which have been chosen 
about where the final values were expected to come. The assumed data are 
these : 


Zine melting: point = 225-22 -4 5-456 419° 
Silver ‘‘ ea Rae Denes Tee cc thee 960 
Copper ‘‘ COON Ges See UR ee Pee 1085 


With actual temperatures 1° higher or lower, the expansion coefficient 
would not be affected by an amount equal to one-tenth of one per cent in 
any part of the curve. The assumed values are, therefore, amply exact for 
the purpose. 


— A. L. Day and J. K. Clement—Gas Thermometer. 439 


Expansion. 
Corrected A/ 1a 
Dat Obs.—Cal. 
a Temperature | Observed Calculated : P 
Feb. 25, 1908. _- 294°0° "002679 "002692 —13 
392°0 "003665 "005638 +27 
491°0 "004660 004619 +41 
592°5 "0056382 "005651 = 1s 
695°0 "006657 "006719 —62 
795°0 "007741 "007788 —A47 
894°0 "008848 "008871 —23 
994:°0 ‘010086 "009991 +95 
Equation used for the “ calculated” expansions, 
A=(8778°6¢ + 1°280127)10~ 
In Furnace III. 
Temperature Distribution along the Bar. 
Left Middle Right 
(Corrected ’ 
12cm 10:2 Hem Temperature) jem 10)cn 12cm 
— 2° | — 1° | — 0° 297°9° — 1° — 9 — 7° 
— 6 — 3 — 1 397°3 — | —= 9 — 8 
— 9 —. 6 = 496°3 — | — 5 — 9g 
—13 —10 = 3 594°3 + 1 — 3 — 7 
—16 " —12 — 4 646°9 + 2 — 2 — 6 
—16 —1]2 — 4 646°6 + 2 — 2 — 9 
—17 —13 — 4 -697°0 + 2 0 — 4 
—19 —14 — 9d 747°8 + 4 + 2 — 2 
— 23 —17 — 6 796°3 =— + 3 6) 
—27 —20 — 7 846°2 + 6 + 5 + ] 
—26 ——2Z0 — 8 897°2 + 6 + 8 + 4 
— 29 —23 — 9 946°6 + 7 +11 + 8 
ie 95 9 1001°5 Seg A SN I ge eae | 
LXPAnsion. 
| = 2/L 
| Corrected 
Dat | — 
ae | Temperature Observed Calculated IU eee 
Apr. 6, 1908 ...|  297-9° 002770 | 002759 | 411 
1 393 003739 | 003730 +9 
496°3 "004720 004723 — 3 
594°3 "005714 "005732 —18 
646°9 "006267 0062838 —16 
646°6 "006262 "006280 —18 
Apr. 8, 1908 ---| 697-0 006800 006815 —15 
747°8 "007346 "007360 —14 
796°3 "007897 "007888 + 9 
846°2 "008445 "008437 + 8 
S972 "009013 °009005 + 8 
946°6 "009579 "009561 +18 
1001°5 °010206 "010187 +19 


Equation used for the “ calculated ” expansions, 
A= (8874-4 + 1:28892")10-° 


440 A. L. Day and J. K. Clement—Gas Thermometer. 


In Furnace IV. 


Temperature Distribution along the Bar. 


Left Middle Right 
Wesese || (Corrected 
120m 10cm jem Temperature) Rem 10cm 12cm 
— 3° | — 2° ON 299°1° — 1° | — 4° — 5° 
— 9 — 3 0 399°2 — | — 4 — 6 
— 9 — 5 — 1 497°0 — 1 = — 7 
—14 — 9 — 2 598°3 0 — 3 — 6 
—16 | — 9 — 3 648-0 + 1 — 1 — 5 
—19 —12 — 4 709°5 + 3 0 — 4 
—21 —15 — 4 748°7 + 4 + 2 = = 
—25 —18 — § 79971 + 6 + 4 ae 
— 30 — 22 — 7 846°1 + 7 + 6415 =e 
SW) —22 — 8 900°4 + 8 + 9 + 4 
—36 — 26 —10 949°6 +10 +138 + 7 
—36 ..| —27 —Il1 1000°5 +12 +17 +11 
Expansion. 

Date Ha@orrected ae Obs.—Cal. 

| Temperature Observed Calculated 

Apr 17, 1908 es) 299oIe ‘002763 002755 + 8 

| 399°2 "003750 "003730 +20 

497°0 "004697 ‘004708 —1 

598°3 "005702 "005748 —46 

648:°0 "006265 "006268 = 3 

709°5 "006889 006921 —32 

T48°7 007344 "007348 ae 

199-71 “007897 "007890 + 7 

846-1 "008423 "008407 +16 

900°4 °009018 “009011 + 7 

949°6 °009585 ‘009566 +19 

1000°5 °010160 "010146 +14 

Equation used for the “ calculated ” expansions, 


A=(8814'1¢ + 1°326027)10~° 


The mean of the equations derived from the observations in 
the four furnaces, each weighted according to the number of 
observations in that particular series, is 


A= (8841¢ + 1° 3062°) 10 


which is the equation used to compute all the gas-thermometer 


observations. 


A. L. Day and J. K. Olement—Gas Thermometer. 441 


This interpolation formula is a simple equation of two 
coefficients obtained by the method of least squares, giving 
equal weight to all the observations. 

Inasmuch as no one of the differences between observed 
and calculated values reaches 1 per cent in value, this form of 
equation, which has been frequently employed for the pur- 
pose, is perhaps as well adapted to represent the experimental 
data as another. After it was discovered that the bar after 
heating did not return to its initial length, but varied within 
considerable limits from one heating to another, it became 
apparent that if the contraction upon cooling was not uniform, 
the expansion on reheating was probably also irregular to the 
same degree, and that the room temperature observations 
could not be expected to follow this or any other simple 
equation very consistently. That such irregularities exist: and 
attain such magnitude as seriously to limit the power of any 
simple formula to reproduce the expansions over the whole 
range will be immediately apparent from an examination of 
the columns of differences (Obs.—Cal.). It. is more directly 
observable in the experimentally determined values of the 
expansion between 0 and 300° taken from the four series which 
have just been given. 


Measured Expansion in Millimeters 
between 0 and 300°. 


Wee a0. WOO fet ete! ey a ne 0-687™™ 
ens. 1908) cus ee .- 0°681 
TBAT Uike TOR pAG) OG ie teehee Dies ts Mee Spee 0700 
A evit LO0S. rr. eI 0:696 


By way of experiment we tried an equation of three coeffi- 
cients on the last two series, both of which contain observations 
at 50° intervals, omitting in each case the room temperature 
observation in which the irregularity in the expansion itself 
chiefly appears, and found it possible to reproduce the meas- 
ured behavior of the bar in the region from 300° to 1000° with 
differences less than one-fifth as large as those recorded in the 
tables above. There is, therefore, abundant evidence that the 
uncertain region is confined to the lower temperatures and that 
the higher temperatures have so far offered no serious difficulty 
or irregularity, either in measurement or convenient represen- 
tation. The expansion measurements over the entire range 
from 0° to 1000° are probably in error by about 0°5 per cent, 
most of which is directly attributable to these irregularities in 
the behavior of the metal at the lower temperatures. In the 
gas thermometer this corresponds to about 0°25° at 1000°. 

This uncertainty in the expansion of the metal at low tem- 
peratures appears in the gas thermometer data as a difference, 


442 A. L. Day and J. K. Clement—Gas T. hermes 


from one day’s observations to another, in p,,—the pressure of 
the gas at 0°,—which will be found to vary irregularly within 
narrow limits. 

The Pressure Coefficient of Nitrogen.—A number of deter- 
minations of the pressure coefficient of nitrogen, under differ- 
ent initial pressures, were made by observing the pressure 
inside the bulb when it was immersed alternately in ice and in 
steam, and with the following results : 


__' Pioo — Po 


Initial Pressure a = 00m No. of Observations 
leet 0°003665 4. 
550 005668 5 
744 "003670 6 
985 "003673 12 


Chappuis has obtained the following values of a: 


Initial Pressure pepe eee 
100 
529mm. 0:00366811 Traveaux et Mémoires 
: du Bureau International 
oe pe es des Poids et des Mes- 
ae 95 00364477 ures, vols. 6 and 12. 
ety 9) : { 


Computation of Results—The tormula for the constant 
volume gas thermometer may be written in the form, 


SNE Pe PBs 
1 + at 1 + at, 1 Shot are ee 1+ at’, 1+at’, 
In this equation : 
V..:= welime ofcbullbiati® 20s see ye eee 195°547°°. 
V = volume of bulb at 7°. 
p, = initial pressure, 1. e., pressure when bulb is at 0°. 
p = pressure at temperature of 7°. 
v, = portion of “unheated space” enclosed in furnace 
(in which temperature varies from the tempera- 
ture of the bulb to that of the room)--_-__---- O-L61°°. 
v, = portion of “ unheated space” outside of furnace .. 0°128°. 
¢, = estimated mean temperature of v, when bulb is at 2. 
¢’, = estimated mean temperature of v, when bulb is at 0°. 
t, = temperature of v, when bulb is at @°. 
t’, = temperature of v, when bulb is at 0°. 
a = expansion coefficient of nitrogen under constant volume, 
8 = linear coefficient of expansion of platinum-iridium alloy. 
at pis OPN v, NG 
Writing A 3es Tia cer Ty 


and 
GBB) sing 
1 +a, 


A. L. Day and J. K. Clement—Gas Thermometer. 448 


the equation may be transformed into a more convenient form 
for computations : : 


D 1+ 56t 
tana cee ° 


Pee Ae = B 


0 


Here 38¢ represents the correction for the expansion of the 


bulb and A — = B is the correction for the unheated space. 


In computing p the mercury columns were corrected in the 
usual manner for temperature and latitude. 

Gas Thermometer Measurements.—Table I contains some 
of the earlier results, which were obtained after the temper- 
ature gradient along the bulb had been partially corrected. 
During this series of observations, the temperature difference 
between the middle and either end of the bulb varied between 
50 and 150 M.V. (5° to 15°-). As it was impossible entirely to 
eliminate the gradient with the arrangement of coils in use at 
this time, the heating currents were adjusted so as to have the 
gradients toward the top and bottom of the bulb of opposite 
sign and of nearly equal value, thereby materially reducing 
the magnitude of the correction to be applied. 

Before beginning this series of observations and again after 
its completion, the thermo-couple ‘ P” was calibrated by deter- 
mining its electromotive force at the zinc and copper melting 
points. From the results which follow it will be seen that the 
electromotive force of the thermoelement, at the temperature 
of melting copper, has been lowered 15 M.V. (1°2°) through 
iridium contamination during the series of measurements. 


1906 Zinc: — Copper. 
72) 3g LRU Remnag pea F.* 3398 10488 
M. 3398 10483 
3398 10486 
Moy sleet) 2s F. 3396 10469 
M. 3398, 10472 
3397 10471 


After these observations (Table I) the furnace was rebuilt. 
In place of the heating coil of platinum-iridium alloy, a coil 
of pure platinum was substituted. At the same time the 
arrangement of the two auxiliary heating coils was so modi- 
fied that by proper adjustment of rheostats, the gradient along 
the bulb could be reduced to 0°5° or less. 

In order to eliminate, as far as possible, any error due to the 
contamination of the thermo-couples with iridium, the couples 


* F = Freezing point, M = Melting point. 


444 A. L. Day and J. K. Clement—Gas Thermometer. 


Tape I. 


Tnitial pressure, 302°3™™, 
a= 0°003665. 


Average temperature difference between middle and either end 


of bulb, 10°. 
Equation used for “ calculated ” temperatures, 


T = 50°19 + 0°11176E — 1:289 x 10-°H”, 


1906 ie een Op 5, Temperature) Temperature) T (obs.)— 
(mm) ec noeolte Observed | Calculated £ (cal.) 
Ap]. 30. 30°209 BOS IIS 396°8° 397°8° —1°0 
| 4738: 550°4 550'8 — “4 
6232: 696°5 696°6 — -] 
(a02s 797°6 T97°5 amie we 
8428: 900-2 900°5 — 3 
9547° 998°4 9996 —1:2 
11004: 112375 1123°9 — 4 
May 1, 30°220 
May 2 POG = 368°6 369°8 —1°2 
| 4944- ole? Dy Tle2 — 0 
6448: TAGS (Ane? + °6 
IBS S 818°6 818°2 + ‘4 
8094: 869°7 870°3, — ‘6 
9040: 954°5 955°1 — °6 
9750° 1016°4 WOW es — °9 
10583°t 1089°9 1188°5 se ils, 
May 3} 30°229 
May 4| 3928: 470°0 469°3 +. °7 
| 5186: 595°2 Hse + 2 
5944: 669°1 668°9 + °2, 
6725° 743°8 743°4 -_ -4 
T755° 839°7 839°3 + °4 
eee ONE 973°1 974-1 =i oe 
10135° 1049°9 1050°4 — °5 
May 5) 30-230 
May 7 3918: ¥ 468°0 468°'3 — °*3 
6926° - . 762°8 762°4 + *4 
8910" 943°4 943°6 — 2 
10631° 1092°8 1092°6 + 2 
1264" EO ip habe met +1°6 
May 9| 30°252 
| 


were calibrated from time to time by metal melting point 
determinations. Columns 7 to 10 of Table II contain the 


* Observations below 415° were not used in computing the parabola. 
+ Temperature fell 2° during observation. 


— > Temperature in Degrees, 


A. L. Day and J. K. Clement—Gas Thermometer. 445 — 


E.M.F’s of the standard thermo-couple “ W” for these eali- 
brations. 

As a check against accidental errors of observation, all 
observations were made in pairs, with an interval of from five 


Fie. 8. 


J SSS eek eee eee eee eee 
i eee se ee ee eh eels bee feo | 
JS eae ee ae ae eee ees 
JSS ae Rae SaaS eee eee ea eae 
_ Se RSS anaes ee aaa eee ee 
J JS See Sees es ae eee aaa eee ees 
PEELE EEE EEE Ppt 
a te a ee ee al I ae be ae oe 


1100° 


1000° 


|_| (sol gs 
BE eo Oe ap FR | 2h 
SSeS aS SES ese se 2a aR eee 


SSS SSS et 


900° 


800° 


ie 
Ba Sh PEE ae Bs ea a 
_ JSS Se EMS es eS aes ea eee ees see 
ee 


600° 


Se 
=eS Sn SEZ i Ea dF | Se 
_ JS Se Aes eer eos ee wes ae ees 
_ ene 2 eee See ae eee Ree eee eee 
JU Se Anes ae eae ees eae eee eee 
ttt ep 
7240 es Ja PY cas SS A es 
J Zh 2 SRS ORE Sea Ree eRe As eee eee 
Zoos RE Sa Saas eee ae eae ee eee eee eae 
2 Sea SE Sea ae Sse aaa eee eee sees 


500° 


400° 


4000 5000 6000 7000 8000 9000 10000 
——> MV. 
Fic. 8. Curves showing the systematic differences (much magnified) 
between the observations and the parabola which best represents them. 
For the dotted curve the ordinate (above and below the full curve) 
is 1 div. = 0-2”. 
to ten minutes between. The constants of the equation: 
E572 + 01124998 — 1°35512 « 10-°E 


300° 


446 A. L. Day and J. &. Clement—Gas Thermometer. 


TABLE 


3 


Thermo-couple ‘‘W.” Initial pressure, 287°5"™. a=0-003665. Maximum 
Equa- 


temperature difference between middle and either end of bulb, 0°5°. 
tion used for ‘‘ calculated” temperatures, 


T = 61°72 + 0°112499K — 1°35012 x 10-* KE? 


E.M.F. THERMO-COUPLE ‘* W ”’ 


Initial [P°™™-\Opserved) on (op 
No. Date Pressure es Temper- ae 5) 
Po. | ature +} Ca ae 
2 M.V. Zine 
1907 
Feb. 4 3403 
Mch. 6] 28°755 
1 ge 6 3967" 414°49°| — 0°64° 
2 ee 6 d371° 414:96 | — ‘a9 
3 Ho 6 d002°* | 4381°76 | — 40 
4 a 6 30386°* | 4382°25 | — -82 
es 6 | 28-739 
4) a 7 3416° 419:96 | —  °28 
6 “s 7 3417° 420°00 | — ‘dl- 
7 fe 7 do71* | 486°23 | + 06 
8 cs i d974°* | 436°40 | — -08 | 
9 oh a 3789°* | 458°55 | + 03 
10 oe 7 3793°* | 458°94 | + O01 
on 9 | 28°734 
11 es 12 3309°* | 408°51 | — °63 
12 ef 12 3310°* | 408-71 | — ‘538 
18 a 12 3430° 421-50 | — ‘1d 
14 ie 12 3429° 421°50 | — °04 
15 os 12 3040°* | 432°83 | — 15 
16 ms 12 3040°* | 432°89 | — 09 
s 13 | 28°785 
‘“ 14 F, 3405 
M. 3404 
ce 14 | 28°735 
1g os 15 10430°5 | 1078-02 | + 31 
18 is 15 10419° |1077°05 | + °31 
+e 15 | 28°7389 
ie 16 
19 ie 20 9671° |10138°17 | + °22 
20 a 20 9664- |1012°48 | + -:08 
21 ee 20 10446° |1079°96 | + -95 
22 ae 20 10426: |1078:26 | + 93 
23 eS 20 10484° |1079°02 | + 1:02 
24 i 20 9895°5 |1032°75 | + °49 
25 AS 20 9895" |1082°70 | + 48 
eae F. 3405 
M. 3405 
Be 23 | 28°755 
Apr. . 2/3 
#3 22 | 28°751 
26 # 23 3383" 416714 | — -70 
27 dg 23 3384° 416°26 | — °64 
28 é 23 4393° 520°07 | + 29 
29 es 23 4388° 519°71 | + -44 
30 J 24 4095° 489-79 | + 11 
31 ee 24 4097- 489°89 | + ‘01 


Silver 


Gold 


Copper 


F, 9046 
F. 9046) 


10214 
10214 


10461. 
10461. 


10463,» 
10462. 


10497. 
10456. 


10454. 
10454. 


* In computing the constants of Equation (1) the observations marked * in 
Table II were omitted in order to equalize the intervals between points. 
+ The column of ‘‘ calculated” values has been omitted-from Table II for 
The column of observed temperatures and 


the convenience of the printer. 


the column of differences together contain all the information required to 
reproduce the calculated values obtained from the equation above. 


A. L. Day and J. Kk. Clement—Gas Thermometer. 


44.7 


_., |/Ehermo-| | 
“ Initial couple Observed T (obs) 
ate |Pressure} {, Ww | Temper- | — T (cal) 
Po. | yy vy. | aturet | 
\Apr. 24 | i 5073-51 S8007) 4... -40° 
fas‘ 24 LeaO re Om aS Oe dist. SA 
as 24 | | 6104° | 688:°44 | + ‘52 
es 24 | 8°756 | 6099°5 | 687°84 | + °35 
ce 95 
a 26 | 4700-5 | 500°81 | + °23 
bees 26 4698° | 500°65 | + 32 
hess 26 | 6962- | -769°49 | +. °28 
pane 26 | 6957°5 | 768°86 | + °03 
faye 26 8020°5 | 866°45 | — °40 
Se 26 | 8029= .) -S67-99_ )-, .-37-| 
fees 27 5648- | 644:34 |} 4 -44 
yeas 27 | 0646° 644-24 | + 55 
bess 27 | 9036°° | 957°20 | — 42 
NOE as te (9004-5. | 9908°31 | —_ 739 
rs 29 Momo. fea otO0 sa — 10286 
ae 29 | 3716° 450°76 | — °29 
Ee 29 10190°5 | 1057°32 |— -10 
ae 29 8-755 |10188- |1057:°09 | — -11 
Weert 29 
May 1/10 
ge 13 | 3480: AD AO =o 4G 
fee 13 | 3438°5 | 422°06 | — “47 
ae 13 | 67715 |. 75162 |.4+ 18 
e 13 | 6769°5 | 751°36 + °18 
cis 14 | | 5845°5 | 663°62 | + -59 
af 14 | — 9848- 663°33 | + :06 
or 14 | 9274: O7Sst0 Me coo 
pt 14 | 9281: 978°82 | — 28 
‘et 16 4907° 571°49 | + °37 
hea 16 4906- O71°37 | + 739d 
oy 16 | (242° 795-42 | + 05 
ry 16 7243° 7935 °46 
pease 16 7240: 795°24 | + -06 
Kaas 16 10188- |1056°91 | — :29 
| eS 16 10177- | 1056-15 | — -12 
= 17 6338° 710°27 | — -08 
‘3 17 | 6341: PLO 1Oeleee ee LE 
Bs aSr¢ 8272: 888°96 | — °63 | 
ae ay 8277: 889°50 | — °d4 
tyes 17 9024: 955°74 | —~  °82 | 
paste ay | 9015- 955°01 | — °76 
} 
rier 18 3891- 468:56 | — °38 
ple 18 3894°5 | 468°94 | — °35 
aie 18 | | 7730°- | 839°99-| — ~.-41 | 
ais 18 | 7725° | 839°46 | — °45 | 
Eire 18 S741-- | 930-700) — --84 
ie 18 O40 a4) 950-62 | —-" “85 
Pt 19 | 28°763 
| ** 20/22 | 
| és 23 


K.M.F. THERMO-COUPLE ‘‘ W” 


Zine | Silver | Gold Copper 
| | | 
| 
| 
| 
| | 
| 
| 
Ip, 3400 9046 | 
M. 3400. 9050 
| 
| | 
| 
| 
F. 3398 9040 10212 
M. 3398 9040) 10216 
| IF. 9042) 
| M. 9042 


| 


eae 


448 A. L. Day and J. Kh. Clement—Gas T hermometer. 


were computed by the method of least squares. In computing 
these constants the observations marked* in Table II were 
omitted in order to equalize the intervals between points. B 
comparing the T(obs.)—T (caleul.) values (Table II, column 
6) of the various pairs of observations, it will be seen that any 
two values at the same temperature agree within 0°1°. With 
one exception, the differences between observed and calculated 
temperatures are all less than 1°. The average difference is 
0-37° and the probable error of a single observation is 0°25°. 

The foregoing table (Table II) contains a complete series of 
76 observations, without omission, covering a period of more 
than three months in time, in the order in which they were 
made and with the control melting points through which the 
constancy of the thermoelements was assured. If we now 
regroup these observations in the order of increasing tempera- 
tures and combine the pairs referred to above, the relation 
between the observed and calculated curves appears in a new 
and interesting light. (Table III.) The average difference in 
column 5, Table III, is somewhat smaller than in Table IL. 
The most notable feature, however, of these differences is their 
sytematic variation. Below 500° the observed values are less 
than the calculated ones; from 500° to 800° the observed 
values are greater, from 800° to 1000° the calculated values are 
greater and above 1000° the observed values are greater. If 
the calculated temperatures be taken as the ordinates of a curve 
of which the E.M.F’s of element “ W” are abscissas, the 
resulting curve will be a parabola, slightly concaved downward 
(fig. 8). 7 | 

Tf a the differences in column 5, Table III, be plotted on 
their proper ordinates, measuring upward from this parabola 
when the difference is positive and downward when it is nega- 
tive, the second curve will cross the first in three points, form- 
ing two loops of about equal length and area. In fig. 8 the 
dotted curve represents the observed temperature curve, with 
the deviation from the parabola plotted on an exaggerated 
scale. From this diagram, as well as from the figures in 
column 5 of Table III, it is apparent that a simple equation 
of the second degree is no longer quite competent to express 
the electromotive force of the thermc-couple as a function of 
temperature with the full accuracy of the measurement. In 
their paper on the electromotive force of metals of the platinum 
group, Holborn and Day* state that the “relation between the 
thermoelectric force and the temperature in metals of the 
platinum group could be represented, within wide limits, with 
an accuracy of +1:0° by a function of the second degree.” 
The results of our experiments are represented by a function 


+ This Journal (4), viii, 46, 1899. 


A. L. Day and J. K. Clement—Gas Thermometer. 449 


of the second degree, between 400° to 1100°, with an accuracy 
or -+0°5°. The differences between our observed temperatures 
and the temperatures calculated from formula I, however, 
cannot be attributed wholly to observational error on account 
of their systematic variation. For greater accuracy than 0:5° 
it will therefore be necessary to use a different equation— 
perhaps an equation of four parameters. 


Taste IIL. 


(1) T = 51°72 + 0°112499EH — 1°35512 x 10-°E? 


} 


_Thermo-couple Temperature 
Gpepation ae Fos pa eal 
1 ne Observed | Calculated 
1, 2, 5, ? 13, 14, | | 

26, 27, 50, ol 3407-7 418°97 419°35 — 38° 
46, 47 3717° 450°88 451-16 — 28 
[8 Re ie 3892'8 468°75 — 469°13 — “38 
30, 31 4096° 489-84 489°80 | + 04 
28, 29 4390°5 019°89 519-53 + 36 
36,3% . | 4699°3 500°73 500°47 + 26 
58, 59 4906-5 1:43. |- 9571-08 + °30 
D2, 33 | d073° 587°99 087756 + °43 
42, 43 5647" 644°31  648°80 + ‘ol 
d4, 39 | 5846°8 663°48 663-16 + °382 
34, 35 | 6101°8 688-14 687°73 + -°41 
65, 66 6339°5 710-49 | 710°45 + °04 
02, 09 6770°5 70144 | = 751°24 + ‘1d 
38, 39 | 6959°8 76918 | 769-06 + °12 
60, 61, 62 7241°7 795°37 795°39 + -02 
73, 74 T727°5 839°71 840°15 — “44 
40, 41 | 8024°8 867-22 867°25 — 03 
67, 68 | 8274°5 889°23 889-82 — 39 
75. 76 8740°5 930°66 | 931°90 — 84 
44, 45, 69, 70 | 9032-2 956°68 957°28 — 60 
56, 57 9277°5 978-45 78°78 — ‘32 
19, 20 | 9667°5 1012-80 1012°67 + 13 
24, 25 9895°3 1032-73 1032-25 + °48 
48, 49, 63, 64 | 10185°9 1056°87 1057-04 — ‘17 
17, 18, 21, 22, 23 | 10430-0 1078°31 1077-68 + 63 


The numbers in column 1, Table III, correspond to those in column 1, 
Table Il. The figures in-columns 2 and 3 represent the means of the corre- 
sponding figures of Table II indicated by the numbers. 


After the series of observations represented by Tables II » 
and III, the bulb was evacuated and refilled with nitrogen 
under a somewhat higher initial pressure, p, = 325™™. With 
this filling, the results contained in Table IV were obtained. 


1 


450 A. L. Day and J. K. Clement—Gas Thermometer. 


TaBue IV. 


Thermo-couple “ W.” 

Initial pressure 325™™, 

a= ‘003665. 

Equation used for calculated temperatures same as in Tables 
IT and III. 

T=51-72 +0'112499K — 1:35512 x 10~°EH’. 


Thermo- TEMPERATURE - T (obs.)— 
1907 couple “ W” : T (cal.) 
Microvolts Observed Calculated ie 
June 3 4025: 482°10° 482°58° — ‘48° 
4026° 482°15 482°68 — *d3 
5009° 981°29 581°23 + °06 
5017°5 08222 582:07 + °15 
5978" 675°32 675°81 == oY) 
SOT: 675°07 675°43 — °36 
June 4 6238'5 700°88 700°81 + °07 
6239: 701°05 700°S6 + ‘19 
June 6 6992° THEANO HOOT + °03 
6988: alice (EHO + 02 
May 29 7486°5 818°65 818°00 + °65 
7T495° 819-00 818°78 + °22 
June 4 7954: 860°52 860°81 — °29 
7952° 860°47 860°63 — °16 
June 3) 8488°5 908°47 909°03 — °56 
8488°5 908°57 909°03 — "46 
June 4 “=O OMG: 955°30 955°86 — °56 
9011: 954°91 955°42 — *5] 
June 5. 9474: | 99532 995°91 — “59 
| 9480: 995°86 996°43 — ‘57 
June 6 | 9975° 1038°82 1089°07 — 25 
| 9940: 1035°65 LO35522 + *43 
10197°5 1058'd50 1058°53 — ‘03 


Column 5, Table IV, contains the differences between 
the observed temperatures and the temperatures calculated 
with the equation used in the previous series (Table ITT) 


T = 51°720 + °11250K—1°35512 x 10-°H’. 
The average difference is 0°33°, and the maximum difference 
0°65°. 
The agreement between this series of observations and the 


preceding one is so extraordinarily close that not only the 
same equation serves for both but the differences “ obs.—cale.” 


A. L. Day and J. K. Clement--—Gas T. hermometer. 451 


are of the same order of magnitude and similarly distributed, 
thereby confirming the conclusion that the observations are 
more accurate and consistent, within this temperature region, 
than the interpreting parabola. 

Metallic Melting Points.—By way of establishing perma- 
nent records of these observations, the usual procedure was 
adopted of determining various metallic melting points which 
occur within the range of the temperatures investigated, with 
- the thermoelements which had been directly compared with 
the gas thermometer. The metals chosen for this purpose 
were gold, silver, copper and zinc. Metal melting points were 
given the preference over pure salts which have been repeatedly 
suggested for this purpose, (1) on account of the greater sharp- 
ness of the melting point, (2) on account of their general 
availability for such determinations, and (38) because of the now 
very generally established custom of comparing the results of 
different observers through the medium of these standard 
melting points. 

In choosing the materials for such determinations, two not 
altogether concordant standpoints must be recognized; (1) the 
materials used must be of absolutely known composition and 
of high purity in order to give the melting point determina- 
tions a positive significance ; (2) the same materials in the same 
purity must be easily obtainable by other investigators in 
order to enable the results to be conveniently utilized by 
others if desired. The metals used in this investigation were 
from various sources which will be specified below. Each has 
been very carefully described and analyzed by Dr. E. T. Allen 
of this laboratory, whose report is printed in full. We pre- 
pared none of the metals ourselves. Those which were used 
were purchased from firms who may fairly be expected to 
supply the same nominal quahty to any other investigator who 
may care to use them, but it must be emphasized in this con- 
nection that metals furnished under the same description by 
the same dealer at different times have not always proved of 
uniform purity and probably cannot at present be expected to 
do so. ‘he variations in the thermal behavior of the different 
samples is not great, never amounting to more than 1° in our 
experience ; but we are of course unable to offer any guarantee 
that the same metals obtained in future will remain within 
this limit, nor is the dealer’s guarantee at present a sufficient 
protection. 

As the situation now stands, the errors in the gas thermo- 
meter measurements are rather smaller than the differences 
between the melting points of different samples of a given metal 
obtained at different times from the same dealer and of the 
same (nominal) purity. This may serve to emphasize more than 


452 A. L. Day and J. KB. Clement—Gas Thermometer. 


ever before the desirability of some provision, preferably by the 
Bureau of Standards, for standard metals, the uniform purity 
of which ean be absolutely depended upon, in terms of which 
such constants can be expressed. In the absence of such a 
provision, it is difficult to see just how to make the gas scale 
conveniently available for general use in its full accuracy. 
This is furthermore a matter of considerable importance in 
view of the extended extrapolation to which the gas scale is 
frequently subjected by the use of thermoelements or other- 
wise. Supposing the metal melting points to be capable of 
reproducing the temperature curve correct within 1° at the 
copper point (1081°), the extrapolation to 1500° may easily 
remain uncertain by at least 5° in the hands of different indi- 
viduals using the same functions for the extrapolation. 

_ Nor is this the only difficulty to which this use of standard 
melting points may lead. On account of the systematic errors 
attending the application of an equation of the second degree 
to the gas thermometer observations, to which reference has 
been made (p. 448), the usual standard melting points are not 
competent to reproduce the gas scale exactly. A curve of the 
second degree, developed by least square solution from seventy- 
six observations which show systematic deviation, cannot 
be reproduced with only the three observations which chance 
to represent the standard melting points. This will be imme- 
diately apparent, though on a somewhat exaggerated scale, 
if we locate on the dotted curve in fig. 8 the tempera- 
tures corresponding to the zine (419°5°), silver (957°9°) and 
copper (1080°9°) points and then undertake to reproduce the 
‘calculated ” curve from them alone. . 

As this is the method almost universally used for the pur- 
pose, it is worth while indicating by a special case exactly 
where it leads. Column 38 of the table below contains the 
actual melting points of four of the purest metals interpolated 
from gas thermometer observations close by. Column 4 
contains the same points computed from Equation lL If 


TABLE V. 
Temperatures Memineratiues 
Element extrapolated Gain cared 
EW? from nearest I Difference 

observation 
Fine fsa 3403° 418°48 418°87 —'39 
Silver ls. 9046° 957°90 958°50 —°60 
Goldicinves! 10214: 1059°26 1059:'42 —'16 
Copper spect 10461° 1080°92 1080°29 + °63 


A. L. Day and J. K. Clement—Gas Thermometer. 458 


now, following the usual practice, we take the melting 
temperatures of zinc, silver and copper and pass a parabola 
through these, we obtain | 


T=55'51 +0°110789 E— 12197 (10) °K? (Equation II) 
instead of Equation I. And if, by way of illustration, we 
recompute all the temperatures of Table III, using this new 


equation and compare the results with those obtained from 
Equation I, we have an illustration (Table VI) of the effect of 


Taste VI, 


Equation I T=51-72+0-112499 HK—1°35512 (10)—*°K? 
Equation IT = T=55-51+0-110789 E—1-2197 (10)-°E? 


No. of Termperauare Obs.-Cale.| Obs-Cale. 
Observation Ob Caleulated | Calculated I II 
| served I II 

125.6, 13, 14 
eae o0ol | 418-97" | 419°35° | 418°97° | —-+38° 0:00 
46,47 450°88 | 451°16 450°46 | —-28 + 0°42 
Wa 12 468°75 469°13 468°31 == iG + 0°44 
30, 31 489°84 489°80 488°84 +04 +1:00 
28, 29 519°89 | 519°53 518°42 + +36 7 
36, 37 550°73 550°47 549°21 + +26 +1°52 
58,59 571°43 571:08 569°73 +35 =n 
32.33 587°99 | 587°56 586°15 +43 + 1°84 
4943 644:31 | 643°80 642°94 S55 | LL Oy 
54,55 663°48 663°16 661°58 ERD +1:90 
34, 35 688'14 | 687°73 68611 +-4] DB 
65, 66 710°49 710:45 708.84 4-04 Se TRS 
52,58 75)°44 751:24 749-70 to +1°74 
38, 39 769°18 769-06 767°50 +'12 | +168 
60,61,62 | 795°37 | 795°35 793°85 aE -()2 E152 
73,74 839°71 | 840-15 S38-S0e 44 +0°91 
A ale 2 le 86 7°22 867-25 866°04 == )% JE ISIS, 
67,68 889°23 | 889°82 888°72 a9 +0°51 
75, 76 | 980°66 | 931°50 930°68 | —°'84 — 0°02 
44,45,69,70 | 956°68 | 957°28 956-68! | ——"60 0:00 
56,57. | 978-46 | 978-78 | 978-35 | —-32 EOP) 
19, 20 | 1012°80 1012°67 | 1012-57 45413 + 0°23 
24,25 | 1032°73 | 108225 | 1032°37 + °48 + 0°36 
48, 49,63, 64 | 1056°87 | 1057°04 | 1057°45 esol T —0°58 
17,18,21,22,23, 1078°31 | 1077°68 | 1078°31° | +°63 0:00 


Am. Jour. Sci.—FourtH Series, VoL. XX VI, No. 155.—NovemsBeEr, 1908. 


454. A. L. Day and J. K. Clement—Gas Thermometer. 


interpolation of this character even when used with the best 
experimental data which we have obtained. The error amounts 
to 2° in the region 600—700°. 

The solution of this difficulty is obviously to obtain additional 
fixed points and thereby to reduce the interval for interpola- 
tion but we have so far found difficulty in obtaining suitable 
substances. The metals which melt in the desired region either 
are not obtainable in uniform purity or easily become oxidized 
or otherwise contaminated during the manipulation necessary 
for a melting point determination. Suitable eutectic mixtures 
may eventually offer a solution of the difficulty. 

The Metals Used.*—After some investigation, it was found 
that we could obtain in sufficient quantity, silver, copper and 
zine which ranged in purity from about 99°94 per cent to 99-997 
per cent, and gold which was probably still purer. These 
figures do not include oxygen nor carbon (except in case of 
the silver), for, since the melting points of the metals had to 
be determined in carbon crucibles, it is evident that the pres- 
ence of these impurities would have no significance for present | 
purposes. Of course it would have been possible to prepare 
these metals, or at least the zine and copper, in still purer 
condition, but it was not thought to be worth while, since it is 
improbable that the most refined of present-day methods could 
safely determine any difference between the melting points 
of the chemically pure metals and those actually used. 

The Gold.—About 250 grams of “ proof gold” were obtained 
from the Philadelphia Mint. It was prepared by Mr. Jacob 
Eckfeldt. A sample of gold prepared in a similar manner by 
Mr. Eckfeldt was used by Prof. Mallet mm his determination of 
the atomic weight of this metal. The method of purification 
is given inthe Am. Chem. Jour., vii, 73, 1889. Prof. Mallet 
found no systematic difference between this gold and two 
other samples, one of which was obtained from the Mint of 
England, and the other of which was prepared by himself. In 
view of these facts, it was evidently unnecessary to analyze the 

old. 
: Regarding the methods which were used in the analysis of 
the silver, copper and zine, there will be no need of giving all 
the details, especially where accurate methods of procedure 
are well known, but in view of the very small quantity of 
impurities estimated, some explanation and some conclusions as 
to the accuracy of the data will be presented. Most of the 
work was done in a new laboratory under exceptionally favor- 
able conditions of cleanliness; large samples, generally 100 
grams, were taken for analysis and the reagents were subjected 
to rigid examination. Separations were always repeated, in 


*By EH. T. Allen. 


A. L. Day and J. K. Clement—Gas Thermometer. 455 


some cases many times, and filtrates were not rejected until 
they had been reduced to small volumes and had been proved 
free from ee elements looked for. Of course, the accuracy 
of such work is most satisfactorily tested by synthetical 
methods. Mylius and Fromm,* by using a preparation of 
metallic zine in which they could find no impurities, were able 
to detect gualitatively as little as 0°1"8 of lead, cadmium or 
mercury, in a solution containing 40 grams of zine, without 
difficulty. Quantitatively, I have never found greater varia- 
tions than ‘002 per cent in duplicate determinations of the 
heavy metals in silver, copper or zine, with a single exception 
which was rejected, and some of the figures agree closely in 
the ten thousands of a per cent. 

The Silver.---This metal as well as the gold, was prepared 
by Mr. Eckfeldt at the Philadelphia Mint. A block weighing 
about 100 grams was cut from a larger brick with a hard cold 
chisel, and after cleaning, transferred to a large casserole of 
Berlin porcelain and dissolved in a slight excess of nitric acid. 
During the operation the dish was covered with a watch glass. 
A small black residue was now filtered off on the felt of a 
large porcelain Gooch crucible, washed and dried. The 
asbestos of the felt was previously heated to redness. The 
residue was then laid in a porcelain boat which was slipped into 
a combustion tube containing copper oxide and heated in a 
eurrent of oxygen. The outflowing gas was passed through a 
very dilute standard solution of barium hydroxide, 1° = 0:97™8 
of CO,, in which a decided white precipitate appeared at once. 
The excess of baryta was then titrated with standard acid. 
A blank determination previously made gave no precipitate 
in the baryta water. This determination is of no importance 
as regards the melting point of the silver, since the metal had 
to be melted in graphite, but considering the source of the 
silver and its unusual degree of purity, the determination may 
be of some interest. What remained of the residue after the 
carbon was burned, was extracted with aqua regia. The 
solution was evaporated to dryness, taken up with hydro- 
chloric acid and the gold precipitated by sulphur dioxide. 
The filtrate from gold gave a slight black precipitate with 
hydrogen sulphide. This precipitate weighed only 0:1™ after 
it had been glowed in a small porcelain crucible, but it 
remained black, dissolved in a few drops of aqua regia which 
left a yellow stain when evaporated, and gave a very strong 
rose color when dissolved in water and tested with a drop of 
potassium iodide,—all characteristic of platinum. It was sus- 
pected that a trace of platinum might exist in the acid used to 
dissolve the silver, but a blank test on the same quantity of 


* Zeitschr. anorg. Chem., ix, 144, 1895, 


456 A. L. Day and J. K. Clement—Gas Thermometer. 


reagent proved the contrary. The silver solution was now 
diluted to several liters and precipitated with hydrochloric 
acid. The filtrate was evaporated in porcelain to a small 
volume and in this the remaining impurities were sought for 
by well-known methods. Only lead and iron and the merest 
trace of copper were found. A blank determination was made 
for iron. Found in the silver + reagents, 0013 per cent; in 
the reagents, ‘0002 per cent; leaving -0011 per cent in the 
silver. 

For the estimation of sulphur, a separate portion of 38 
grams was taken, the silver was removed in the same manner, 
and the filtrate evaporated to dryness in porcelain. The 
small residue was then evaporated again with hydrochloric 
acid to decompose nitrates. The final residue was dissolved 
in a small volume of water acidulated with hydrochloric aeid, 
filtered to remove any silver chloride which might have escaped 
precipitation and precipitated with barium chloride. Found 
1-478 BaSO,, while the same quantity of reagents gave 0:4™8 
BaSO, : S = ‘0004 per cent. 


Analysis of Silver. 


WAN SHIMON 2 i Sagem weit pee hal au none 
Sb Bia bike iy eee cee 6¢ 

Sr Dr) OE Re Sea bal 6¢ 

ACU fe tet Geo ea sgt as "0005 

| ie RG alee eS ee eS ‘0001 
Opes re ot eRe te merest trace 
Bier) 225 ee ae een OMe 
ds opener 2 AES pe hae <9 ‘0008 
hot Vic eek a See none 
Cd Sy 1 Bg eG Ok aCe (1 

Tn PN CEE Ne aaah ep ee 66 

ING ee ea ee 

Co ere tele is Cpe tars (45 

| eng cae SA hse Aes ‘0011 
S the US Canes Pa aes eee QO O4 
Cee. Soest, SOUS} 

0032 % 


The Copper.—The copper was of the form known as “ cop- 
per drops cooled in hydrogen” and was obtained from Eimer 
and Amend of New York. Not all copper of this brand is 
equally pure. The sample analyzed was a portion of a 25 |b. 
lot. The method followed in the analysis was essentially that 
of Hampe,* in which the copper is separated from the impuri- 
ties by precipitation as cuprous thiocyanate. A 100-gram por- 


*Lunge, Chem.- tech. Methoden, ii, 202. Chem. Ztg. 1691, 1898. 


A. L. Day and J. K. Clement —Gas Thermometer. 457 


tion was placed in a large casserole of Berlin porcelain, dis- 
solved in nitric and sulphuric acids and the solution then evapo- 
rated to drive off the excess of nitric acid. This troublesome 
operation can be greatly facilitated by the use of a crown 
burner, though as dilution and evaporation have to be several 
times repeated, small losses are difficult to prevent. Duplicate 
determinations, however, proved that they were entirely neg- 
ligible as regards the small percentage of impurities. The sul- 
phate of copper was now dissolved in water and diluted. A 
little HCl was added, and after standing, the solution was fil- 
tered. The residue left on the filter was extracted with am- 
monia to remove silver chloride and the remaining part of it 
was treated with aquaregia. There was still left a little silica, 
from the porcelain dish in which the copper was dissolved. 
The solution obtained by aqua regia after the nitric acid was 
entirely driven out by hydrochloric acid, was tested for gold 
by sulphur dioxide. There was no precipitate in the cold 
even after long standing, though evaporation caused the pre- 
cipitation of about half a milligram of black metal. This 
remained black on heating, dissolved only partially and with 
difficulty in aqua regia, and with sulphuric acid and ammo- 
nium nitrate gave a faint blue color. These tests indicate irid- 
ium, though there was too little to identify with certainty. 
The rest of the solution which had been tested for gold was 
precipitated by hydrogen sulphide and the precipitate was fil- 
tered, washed and burned in a porcelain capsule. It formed a 
yellow chloride with aqua regia, gave a precipitate with am- 
monium chloride and a very strong test for platinum with 
potassium iodide. This platinum did not come from the acids 
used to dissolve the copper, since the same quantities were very 
carefully tested by hydrogen sulphide after nearly the whole 
portion had been driven off by heating in porcelain, and found 
to contain not a trace. 

The solution containing the copper was then warmed and 
saturated with sulphur dioxide. After standing, a further 
portion of silver was precipitated, filtered off and washed. It 
was then dissolved in a little nitric acid, precipitated again as 
chloride and added to the main portion of the silver chloride, 
which was dried at 130° and weighed. 

The solution still containing the copper was diluted to about 
8 liters, and from it all but a small portion of the copper was 
precipitated by a standard solution of potassium thiocya- 
nate, 1° of which was equivalent to about 50™€ of copper. 
The thiocyanate was proved to be free from heavy metals 
by a test with hydrogen sulphide. The small amount of iron 
which it contained was separated before the solution was stand- 
ardized, by the addition of a little ammonium alum followed 


458 A. L. Day and J. Kh. Clement—Gas Thermometer. 


by ammonia. The solution was allowed to stand and then 
filtered from iron and alumina. The precipitation of the cop- 
per was done very gradually with constant shaking to avoid 
carrying down the impurities, and after long standing was fil- 
tered. The filtrate was concentrated to asmall volume in porce- 
lain. A small additional precipitate which came down in this 
process was worked over with care to avoid any possible loss 
of impurities, especially lead, though no metal but copper was 
found in it. The filtrate was then examined as usual. <A 
word is needed in reference to the presence of zinc. This was 
found in every sample examined, in fact, it was generally the 
chief impurity. It was suggested that this zine or at least a 
part of it might have come from the large flasks of Jena glass 
in which the acid solutions of the copper stood. To test this 
point, a sample of copper in which had been found -089 per 
cent of zine was tested again. In this determination Jena 
glass was entirely discarded. The zine found was -091 per 
cent. As these results agree within the limits of error, it is 
evident that Jena glass under these conditions will not con- 
taminate solutions with zine, at least in quantities of this order 
of magnitude. For the determination of silicon in the copper, 
25 grams were placed in a platinum basin, dissolved in nitric 
and sulphur acids, and evaporated over a crown burner to white 
fumes. The residue was dissolved and filtered. The filter 
was burned and the small residue tested for silica by hydro- 
Huoric and sulphuric acids. Since it was feared that some 
silica might come from the watch glass used to cover the plat- 
inum dish during this operation, a blank was carried out with 
the reagents under the same conditions. Within the limits of 
error none was found. 

For the estimation of sulphur the method of Lobry de Bruyn* 
was used, in which the copper is separated from the nitrie acid 
_ solution by electrolysis. Twenty-five grams of metal was 

dissolved in 75° nitric acid diluted with about an equal quan- 
tity of water, and then the excess of acid evaporated as far as 
possible on the steam bath. ‘The electrolysis was done in a 
large platinum basin, which served as a cathode. The basin 
was covered with a glass plate pierced to admit a cylindrical 
platinum crucible which formed the anode. The current den- 
sity was about ‘015 — After a time it was found neces- 
sary to pour off the solution from the precipitated copper and 
remove the free acid by another evaporation. A repetition of 
this operation is advisable. The filtrate from the copper is 
evaporated to dryness in porcelain and the small residue of 
nitrates decomposed by hydrochloric acid. The final residue 


*R. des trav. Chim. de Pays Bas, x, 125, 1891. 


A. L. Day and J. R. Clement—Gas Thermometer. 459 


is dissolved in acidulated water and precipitated by barium 
chloride. | 
_ Found in 25 grams copper, 4:2™2 BaSO, 
ee cen CTnmneEre aeldy: O° 84. 
3°67 BaSO, = :002 per cent. 


Analysis of Copper. 


Sie eee, TONE 
SO igh aoatiaeed bcaga sy, SA 7 
Sn yeh ah ane eb aan & (13 
Se eR LEI SNE one 66 
Te Ticats Ruee hae BaP nd BT 66 
PAR ats epee mes ae CSE 
iPGametals oss: ‘0011 
5 COA hn ee "0007 and °0005* 
Bie ce Po es OMe 
Pb ¥ Bs (<3 
Cd ich Ts eee. 66 
aaa. ssenoek's Baath "0007 
SIN feet tae 8 TAP none 
Oo Aik Ran, ecg ce 
Wee 2 se hae" ae OOS 
le ee eee a" none 
> seen aes Nine ik os oie "0020 
°0083 


The Zine.—This metal was obtained in the form of sticks 
from the firm of Eimer and Amend. The method of Mylius 
and Fromm was followed for the principal impurities.+ 100 
grams were dissolved in nitric acid. The solution was then 
diluted and ammonia was added until the zine at first precipi- 
tated was entirely redissolved. Then enough hydrogen sul- 
phide was added to throw down all the impurities of the 
hydrogen sulphide and ammonium sulphide groups together 
with considerable zinc. The precipitate was filtered off and 
further separations were made as usual. 

The platinum metals and gold were not looked for as it was 
thought quite improbable they would be present, but arsenic 
and antimony were sought for by Ginther’s method.t This 
consists in the volatilization of the hydrides of these metals 
which are separated from the hydrogen which forms at the 
same time by passing the gas through silver nitrate solution. 
A special form of apparatus was used which consists of a 1 
liter round-bottom flask with long neck 35"™ wide at the top. 

*Two separate determinations. 


+ Zeitschr. anorg. Chem., ix, 149, 1895. 
t Lunge, Chem.-tech. Methoden, ii, 322. Zeistchr. analyst. Chem., xx, 503. 


460 A. L. Day and J. K. Clement—Gas Thermometer. 


This is closed by a glass stopper in which are sealed a small 
glass tube passing to the bottom of the flask and serving to 
fill the flask with hydrogen and to replace the gases formed 
in the experiment; a dropping funnel through which the acid 
used to dissolve the zine is mtroduced, and lastly, an upright 
outlet tube surrounded by a small condenser. The outlet was 
connected with a wash bottle containing a solution of silver 
nitrate. As pure zine dissolves with difficulty in dilute 
hydrochloric acid, the metal was reduced to the form of 
shavings by the aid of a lathe. Fifty grams of these shavings 
were introduced into the flask, the air in which was at once 
replaced by hydrogen. Dilute hydrochloric acid was then let 


Analysis of Zine. 


AG ee fe 89 oe ae eee ea, NOME BhOUNIG 
No), te eee ey 002 
Sh ss See ee Not looked for 
Au BEI NT Re) ITN pO ae ae (<4 
BPG es, ae ae el Teemccn el (<3 
AGC ae ca na Shere ek eee NOME 
|) Gilg ae A gas es aks ed ac 
IPD: 2 Cer ie ee eee 051 
CU ORES Oe eae "004 
ING ph pee hae ae he None 
CO Ae ee ee 
OG Aah ie ae a ea "006 
Shih eae ee eee None 
S a nh al 0d 0 Ee igre on lle oe 6¢ 
°063 


in through the dropping funnel. The solution was facilitated 
by warming. At the end of the operation, the gas in the 
flask was driven out by pure hydrogen. The silver nitrate 
solution which contained a black precipitate was then filtered. 
The antimony in the precipitate was determined by dissolving 
it in nitric acid with the addition of a little tartaric acid, 
precipitating the silver with hydrochloric acid, evaporating 
the filtrate to dryness on the steam bath and precipitating 
by hydrogen sulphide. The precipitate was dissolved in 
a few drops of ammonium sulphide, the solution filtered into 
a small tared porcelain capsule, evaporated, decomposed by 
nitric acid and weighed as Sb,O,. After separating the silver 
from the first filtrate which contained the arsenic, 1t was 
evaporated to dryness, reduced with sulphurous acid and 
precipitated by hydrogen sulphide. None was detected with 
certainty. 

If this solution had been tested by Marsh’s method, no 
doubt a trace would have been found, but as its quantity was 
of a different order of magnitude from the other impurities it - 
was not thought worth while to make the test. Giinther deter- 


Ae: Day and J. K. Clement—Gas Thermometer. 461 


mines sulphur at the same time with arsenic and antimony, by 
interposing between the generator and the absorption cylinder 
which contains the silver nitrate another cylinder containing 
potassium-cadmium cyanide which absorbs all the hydrogen 
sulphide and according to him retains no arsenic and antimony. 
Sinee a solution of this cadmium compound is always alkaline, 
it was thought safer to take a separate portion of zinc for the 
estimation of sulphur, silver nitrate being used as the absorp- 
tion reagent. The small precipitate was examined for sulphur 
by dissolving in nitric acid and proceeding as usual. Found 
0-47 BaSO,. Blank gave 0°3™% BaSO,,. 

The zine was tested for silicon in the same way as the 
copper. : 

Redeterminations with other metal samples.—The zine, 
silver and copper melting points were redetermined in 1908 
with other metal samples from the same sources as before and 
serve to show the accuracy which may be expected in random 
samples of the same (nominal) purity. The gold was not 
redetermined for the reason that no second charge was avail- 
able, nor indeed was a redetermination deemed necessary.* 
Complete analyses of these samples have not been made, but 
such tests as were undertaken serve to show that the copper 
was even purer than that of which the analysis is given. The 
results of these determinations are shown in the following 


table: +. 
Thermo-Couple 


1908 Metal eRe Wee SAS Temperature 
March 10_._-... Zine 3404: 418°58 
Miareh £2... 3S . - Silver in CO 9055° 958°78 
pepe WO 2 eee Copper in CO 10476: 1081°5 


Following are the most probable values of the metal melting 
points : 


LINC BN I eo we 418°5°+ 0O°1° 

PME ety e at pe et 958°3 + 0°5 

Ol vcesps cae es sate a 1059°3 + 1:0 

CGD PCiiee hae ox Serge 1081°0 + 0°5 
Summary. 


The gas thermometer problem at the present stage -of its 
development has become primarily a problem for experimental 
study with two definite purposes, one to increase the accuracy 


- * Sometime after our work with gold had been completed a reéxamination 
of the charcoal which had been used to cover the surface of the metal during 
melting, very unexpectedly yielded iron. The gold was also found slightly 
contaminated with iron. The gold point here offered is, therefore, no longer 
entirely above suspicion and will now be repeated as soon as a fresh charge 
can be obtained. The probable error is accordingly given much larger than 
the original measurements indicated. 

+ Determinations by R. B. Sosman. 


462 A. L. Day and J. K., Clement—Gas Thermometer. 


of the measurements, the other to increase their range. The 
application of the gas laws is no longer subject to serious 
question. The progress of recent years has given us electric 
heating in place of gas and the consequent possibility of con- 
trolling the temperature with great certainty and exactness. 
Tt has also given us the metal bulb with a definite and measur- 
able expansion coefficient and capable of holding the expand- 
ing gas without loss. It has discovered a gas which does 
not diffuse through the bulb or react with it chemically, which 
does not dissociate within the limits of practicable measure- 
ment, and of which the expansion can be expressed with 
reasonable certainty in terms of the Kelvin thermodynamic 
scale. It has discovered the source of the errors in the ther- 
moelements and a way to avoid them. 

In 1904, Prof. Holborn of the Reichsanstalt increased the 
range of this scale as far as 1600° C., the probable error of the 
new portion being 10°. Simultaneously with this effort, work was 
begun at the Geophysical Laboratory in Washington with a view 
to increasing the accuracy of the scale, first over the existing 
range (to 1150°}, and later, as much beyond this point as it 
should prove possible to go. Temperature measurements 
between 250° and 1150° have now been made and form the sub- 
ject of the present paper. The particular points to which we 
have given the most attention are the following: (1) To provide 
a uniform temperature along the bulb by a suitable arrange- 
ment of the heating coils. (2) To enclose the furnace in a 
gas-tight bomb in which the pressure outside the bulb can be 
maintained equal to that within for all temperatures. This 
offers three distinct advantages: It provides against the 
deformation of the bulb through differences of pressure within 
and without in the region where the bulb material becomes 
softer. By using the same gas within and without, there is 
no tendency to diffuse through the bulb wall. It enables the 
initial pressure to be varied within considerable limits, thereby 
increasing both the scope and sensitiveness of the manometer. 
The sensitiveness in our instrument with this arrangement was 
about three times that of the Reichsanstalt. (8) The expan- 
sion of the bulb material was determined with great care and 
is probably accurate within 1/2 per cent. (4) The unheated 
space between the bulb and manometer has been reduced until 
the total correction in this hitherto uncertain region amounts 
to less than 5° at 1100°. An error of 5 per cent in the deter- 
mination of its volume or temperature distribution is, therefore, 
practically negligible. It is probable that these changes serve 
to reduce the aggregate error of the gas thermometer in the 
region of 1100° to about one-tenth the magnitude which existed 
at the time of the establishment of the present scale. 

Furthermore, and most important of all, these refinements 
are not limited to this temperature region. It is therefore 


A. L. Day and J. &. Clement—Gas Thermometer. 463 


reasonably probable that the gas scale can be extended to 1500° 
or 1600° with a proportionately small error in its absolute value. 
The immediate future of the present investigation will be to 
undertake this extension. 

The interpretation of these measurements in terms of the 
melting points of readily available substances encounters certain 
difficulties. The melting point of pure salts is not sufficiently 
sharp and is somewhat difficult of interpretation. The metals 
which have commonly been used for the purpose are not obtain- 
able commercially in sufficiently uniform purity to guarantee 
an accuracy within 1° at the higher temperatures. This is too 
large an error for the interpretation of the gas thermometer 
scale in its present refinement. No effort has been made to 
prepare metals in our own laboratory of exceptional purity for 
the reason that such metals would not be available for ene 
use and would therefore be of little service. 

We have accordingly adopted metals which are carried per- 
manently in stock by dealers (whose names are given in con- 
nection with each) from whom the same metal in a nominal 
quality equal to that which we used can readily be obtained. 
We have analyzed these with extreme care to show the exact 
content of the sample supplied tous. We have duplicated the 
purchases ourselves, and have found no errors greater than 1° 
in their melting point determinations. 

Another difficulty arises from the fact that the melting points 
of the purest metals available for use as constants in reproduc- 
ing a high temperature scale (zinc, silver, gold and copper) are 
distributed in such a way that, although they may be located 
upon the gas thermometer scale with a probable error not 
greater than 0°5°, the calculation of a similar curve passing 
through these points does not suffice to reproduce the scale with 
this accuracy. In the region midway between zinc (418°9°) and 
silver (958°5°) the error of interpolation may amount to 2° even 
with metals of exceptional purity. Extrapolation is even more 
uncertain. This can be avoided by locating intermediate 
points which are equally trustworthy, if such can be found. 
We have not been fortunate enough to find points which fulfil 
these conditions satisfactorily but hope that we may yet be 
able to do so. 

_ As the matter now stands therefore we have succeeded in 
perfecting the constant volume gas thermometer until the 
aggregate error afiecting the measurements between 300° 
and 1150° appears not to be greater than 6°5°, but we are 
not yet able to offer adequate assurance that our scale can be 
reproduced by another with this accuracy. This matter will re- 
ceive further attention in a later paper. 


Geophysical Laboratory, Carnegie Institution 
of Washington, August, 1908 


464 W. Duane—Range of the a-Rays. 


Art. XLITL—On the Range of the a-Rays; by Witi1am 
Duane.* 


Tuer researches of Madame Curie, of Bragg and Kleeman, 
and of Rutherford have shown that the a-rays abruptly lose 
their powers of ionizing gases, of affecting a photographie 
plate, and of producing phosphorescence after they have pene- 
trated several centimeters of air or an equivalent thickness 
of other substances. Further, Rutherford has found that near 
the point where it loses these powers the a-narticle still 
possesses sixty per cent or more of its initial velocity. 

Several years ago I made some experiments to determine 
whether the charge carried by the a-particle could be detected 
beyond the limit of its ionizing power, or, possibly, off to one 
side of its range. The results were negative. Recently l 
have taken up the research again at the laboratory of Madame 
Curie of the University of Paris, with more and purer radium, 
and with the additional purpose of investigating the power of 
the a-rays to produce secondary rays, and the transformation 
of the kinetic energy of the a-particles into heat. 

Figure 1 represents the arrangement of the apparatus. A 

is a cylindrical box of brass 3°8™ 
i long and 3:3" in diameter. A round 
hole (1°8°" in diameter) in the bot- 
tom of the box is covered with a 
very thin sheet of mica, B. The 
mica weighs only 2 milligrams 
per square centimeter, and is rein- 
forced on the inside by a grating 
of fine wires. It is so thin that 
the a-rays can pass through it eas- 
ily, and strike the plate C, which 
is connected to an electroscope or 
B electrometer and serves as an elec- 

trode. In order that a magnetic 
R field may be produced parallel to 
Cepmechinnaeu: to jpumips the plate B and to the mica window, 
L, to electrometer or electro. the apparatus is placed between the 
scope ; EH, to earth ; B, to bat- poles of an electromagnet; and in 
Pony pee earn order to produce an electric field 
between the electrode and the window, the ring D, to which 
the mica is fastened, is insulated from the sides of the box by 
wax, and connected to the pole of a battery. 

The method of procedure follows: A very small quantity of 

radium chloride was dissolved in water and recrystallized twice 


* Abstract of notes presented to the French Academy of Sciences. Comptes 
Rendus, 11th and 25th of May, 1908. 


Currents (arbitrary units) 


W. Duane—Lfrange of the a-Rays. 465 


in succession at an interval of several hours, in order to free 
it from most of its emanation and induced activity. Finally 
it was dried upon a flat sheet of platinum. The platinum was 
then held horizontally below the mica window at different 
distances from it, and the ionization currents between the win- 
dow and the electrode were measured by a quadrant electro- 
meter, the window being at a potential of 88 volts above the 
electrode. To make the rays that entered the box parallel to 
each other a set of fine glass tubes (not shown in the figure) 
was fastened between the radium and the window with their 
axes vertical. 

Curve 1, figure 2, represents the ionization current as a 
function of the distance from the radium to the bottom of the 
box. It is evident that most of the ionization in the interior 
of the box disappears if the radium is removed to a distance 
From the window greater than about 2™. 


Wie. 2. 


332 SSR Eee aes 
me PN Eee ae 
bah - SARASSLBAS A 


2a as ea® 
ele teed 


Zz 
Ws 
aa 
Ge 
ge 
mail 
| tty 
ae 
ae8 
a 
Ea 


a Uo 
at ta | 
? 


Volts per second (proportional to 
current) 


Distance from radium to window. ~ Distance from radium to window. ~ 


The currents for distances greater than two centimeters are 
due to a small amount of emanation and induced activity 
remaining after or having accumulated since the final crystalli- 
zation. ‘The a-rays from these, as is well known, have greater 
ranges than have the a-rays from radium itself. The ioniza- 
tion due to these a-rays of longer range is well shown by curve 
2, which represents the currents due to radium (a smaller 
amount than before) that had been left two days in a dry state, 
and which therefore contained considerable amounts of emana- 
tion and induced activity. 

In order to measure the positive charge of electricity car- 
ried by the a-rays, I exhausted the air from the box by means of 
a mercury pump, producing a high vacuum of less than 0001" 


466 W. Duane—Lange of the a-Rays. 


of mereury as measured by a McCleod gauge. This was to 
prevent the charge being neutralized by the ionization of the 
air in the box. I then measured the current flowing toward 
the electrode by means of a Wilson gold leaf electroscope, 
using much more radium than before (about 2 milligrams of 
pure radinm chloride). For these measurements the set of 
fine glass tubes between the radium and the window was not 
used, and the window was kept at zero potential. 

When the a-rays pass through the mica and when they 
strike the metal electrode they produce slow-moving secondary 
rays. In order to suppress these a magnetic field was produced 
parallel to the surfaces of the electrode and window. That the 
magnetic field stopped all the secondary rays was proved by 
the fact that increasing its strength from 2400 gauss to 3600 
gauss did not alter the current flowing to the electrode. 

That there was no appreciable ionization current in the 
interior of the box is shown by the fact that with the mag- 
netic field a difference of potential of several volts between 
the window and the electrode did not alter the current from 
one to the other. 

Curve 3, figure 2, represents the currents of electricity car- 
ried to the electrode by the a-rays. It is evident that the 
greater part of the charge carried by the rays does not pass 
through the mica and reach the electrode, if the radium ts 
more than 2°" from the window. This is the same critical dis- 
tance asfound before for the ionization. By reason of the form 
of the curves near the limit it is difficult to estimate the exact 
length of the range, but we*can say that approximately the 
charge of the a-particles and the ionization produced by them 
stop at the same pornt. | 

Curve 4 represents the currents due to radium in which the 
emanation and induced activity had been allowed to accumu- 
late for over two days. The currents for distances greater 
than 2°" are due to the charges of electricity carried by the 
rays from the emanation, and radium A, and C. 

In order to determine whether or not the a-rays lose their 
power of producing secondary rays at the point where the 
charge and ionization stop, the currents without the magnetic 
field were measured with the radium at different distances from 
the window. Under these conditions the current of electri- 
city carried to the electrode is to some extent masked by the 
secondary rays produced at the lower surface of the electrode 
and the upper surface of the window. If a is the current car- 
ried to the electrode by the a-rays, s, the negative charge car- 
ried per second by the secondary rays away from the electrode, 
and s, the negative charge carried per second to the electrode 


W. Duane—Range of the a-Rays. 467 


by the secondary rays from the window, the total current 
toward the electrode is 


t=O){S ——S, 


The secondary rays s,and s, are stopped by the magnetic fields, 
leaving only the current a. 

If the window is charged positively the electric field from it 
toward the electrode stops part (if strong enough all) of the 
eurrent s,, and if the window is charged negatively some or all 
_of the current s, is stopped. 

To determine how strong, the field must be in order to stop 
all of the secondary rays, the radium was placed 1°5°" below 
the window, and the currents toward the electrode measured 
by the Wilson electroscope when the window was charged to 
different positive potentials. The following values were 
obtained : 


Potential 

+ 0 2. 4 9°5 14 D5 84a le 46S Sat 170r -volitss 
Current 

toe LO ee A235 a fe Oro 0n 92. 9°85 1070 «100 


It is evident from these figures that after a potential of some 
70 volts is reached the current is not increased even if the 
potential is doubled: i. e., 70. volts stops all of the second- 
ary rays coming from the window. If the field is reversed 
about the same potential, 70 volts stops all of the rays coming 
from the electrode. 

The above readings were taken without a magnetic field. If 
a magnetic field of 2800 gauss is produced the current is 1-6 on 
the same scale, and is increased only a few per cent even by 170 
volts. 

We now have a means of studying the secondary rays com- 
ing from the surface of the electrode alone, s,, for by charging 
the window to a potential of + 70 volts or more the current s, 
is suppressed. Then the difference between the currents with 
and without the magnetic field is s,, the secondary rays from 
the electrode. 

To determine whether or not the power of the a-rays to 
produce the secondary rays ceases at the point where the charge 
and the ionization stop, the 2™* of radium chloride were freed 
from emanation and induced activity as before, and placed 
at different distances below the window. The window was 
charged to a potential of +85 volts, and the currents for each 
distance were measured, first without and then with, the mag- 
netic field. The difference between the two currents, repre- 
senting the secondary rays from the electrode cut off by the 


Volts per second (proportional to current) 


Distance from radium to window in cm. 


468 W. Duane—Range of the a-Rays. 


magnetic field, is represented in fig. 3, curve 5, as a function of 
the distance of the radium from the window. 

It is evident that the greater portion of the secondary rays 
stop when the radium is removed further than about 2" from 
the window ; and this is about the same distance as found 
before for the charge of a-rays and the ionization. 

For better comparison the currents measured in the same 
series with the magnetic field, representing the charge carried 
by the a-rays, are plotted on curve 6, fig. &. 

Owing to the form of the curves it is difficult to determine 
the exact point where the effect of the a-rays from the radium 
itself ceases. The'effects due to the small amount of emanation 


Volts per second (proportional to current) 


Charge of secondary rays. Charge of a-rays. 


and induced activity are always appreciable. If there is any 
difference, the curves seem to indicate that the power of pro- 
ducing secondary rays is appreciable a littie further away from 
the radium than is the charge. I do not think, however, that 
we can tell with certainty. 

This point is of great importance in connection with the 
idea advanced by J. J. Thomson, that at a certain velocity the 
a-particle attaches to itself an electron, which neutralizes its 
charge and therefore changes its properties. 

I have tried the above experiments with polonium, but the 
currents were too small to be satisfactory. I hope to be able 
to repeat them with a more active preparation of polonium. 


Distance from radium to window in cm. 


C. H. Warren—Alteration of Augite-limenite Groups. 469 


Arr. XLIV.—Wote on the Alteration of Augite-Ilmenite 
Groups in the Cumberland, R. 1., Gabbro (Hessose) ; by 
C. H. WARREN. 


[Contributions to the Geology of Rhode Island.—No. IIT | 


In a recent paper* descriptive of the geology and petrog- 
raphy of Iron Mine Hill, Cumberland, R. L., it was shown 
that the basic, titaniferous rock rhodose (cumberlandite) was 
closely associated with a strongly metamorphosed and altered 
gabbro, whose areal extent and general characteristics were 
there described. The rocks taken together formed a roughly 
circular area of basic igneous rock entirely surrounded by 
highly metamorphosed, ancient sedimentaries and granite 
intrusives. The close association of the two rocks, and the 
fact that both are characterized by a large content of ilmenite, 
naturally led to a detailed study of the gabbro in connection 
with that of the rhodose. As a result, it was found that, 
while the metamorphism and alteration of the gabbro pre- 
sented many of the common characteristics of such rocks, cer- 
tain mineralogical changes had taken place, which if previously 
observed have not been adequately described, and it is the 
object of the present article to call attention to them. 

The unaltered gabbro.—Although the gabbro is nowhere 
exposed in an unaltered condition, a study of its less highly 
altered forms shows clearly that it was originally a rather 
coarse (millimeter) grained gabbro containing, beside abun- 
dant augite and accessory apatite, an unusual amount of ilmenite 
in the form of large irregular grains occurring in close associ- 
ation with augite. The grain of the rock seems to have been 
generally uniform throughout, although an occasional coarse- 
grained, almost pegmatitic, development has been noted, as 
well as a fine (aplitic?) phase. The optical properties of the 
feldspar indicate a plagioclase of about the composition Ab, An, 
or a little more acid. The textural relations of the feld- 
spar to the augite and ilmenite is diabasic. In habit the feld- 
spar is strongly tabular on 010, the crystals averaging perhaps 
almost 1™ square and from 2 to 3™™ in thickness. The ore 
grains, although now more or less reduced in size by alteration, 
are still large and abundant, many of them averaging as much 
as 4 or 5™™ in diameter. Their distribution seems to have 
been fairly uniform. Locally, in several places, the grains 
have been noted larger in size and much more abundant. 

On treating a polished surface of the rock with hot hydro- _ 
chloric acid the ore grains are but slightly attacked, and no such 
interesting structure (intergrowth of magnetite and ilmenite), 


* This Journal, vol. xxv, Jan., 1908. 


Am. Joug. Sci.—FourtH SrErRiges, Vout. XXVI, No. 155.—Novemeer, 1908. 
33 


470 OC. H. Warren—Alteration of Augite-Llmenite Groups. 


as was noted in the case of the ore in the rhodose, was 
observed. The grains react strongly for titanium and possess 
a magnetic susceptibility like that of ilmenite. Alteration, as 
will be pointed out beyond, often develops the characteristic 
reticulate structure of ilmenite. There can be no doubt, there- 
fore, that the ore in this rock is ilmenite and if any magnetite 
existed as an original constituent 1t was very inconsiderable in 
amount. Occasional flakes of reddish brown secondary mica 
are present. No indications of any pyroxene, other than 
augite, or of other original ferromagnesian mineral have been 
found. 

Chemical composition and classification.—For the purpose 
of showing the chemical character and of classifying the rock 
quantitatively a single chemical analysis has been made on 
material taken from a specimen showing relatively the least 
amount of alteration. The results are as follows — 


Analysis of Gabbro (Hessose). 


Si0, 45°27 

TiO, 207 

Al,O, 18°30 Orthoclase ‘O11 sal 65°93 

Fe LO: 3°30 Albite — "055 fem rs 31°53 a 2°0, Dosalane (2) 
FeO 10°13 Anorthite 104 

MgO 4:08 Corundum ‘006 Q or I, 0 1 Gee ; 
CaO 7°32 Hypersthene -068 : ic Gee ee a 
Na,O 3°64 Olivine 064 : (5) 
K,O 1:07 Ilmenite "034 , 

MnO 86 Magnetite. -02) Ss N20 8) 
Co,Ni tr. Apatite 008 CaO 130 (4) 
PO: 1:27 KO “A 

S 08 Ce why: 

H,O 2-08 NO 380 


The rock is therefore perfelic, docalcic and presodic, its co- 
ordinates in the quantitative system being 2,5,4,3 and may be 
called a Hessose. It may be noted that the ferrous iron and 
titanium are both high, and that although the potash amounts 
to over one per cent no orthoclase has been detected with the 
microscope. Much of the potash is probably now present in 
the biotite and sericite. 

General megascopic character of the rock.—The entire rock 
mass has been subjected to more or less severe dynamo- and 
hydro-thermal metamorphism. The changes thus effected are 


CO. H. Warren—Alteration of Augite-Llmenite Groups. 471 


now somewhat obscured by superficial alteration, but it seems 
clear that their intensity varied quite irregularly, being stronger 
toward the northern and northwestern contacts, and in inde- 
finite zones through the body of the mass. 

Specimens showing the least metamorphism and but little 
superficial alteration may be found in the north-central part 
of the area along an old car track, where the surface of some 
of the ledges has been blasted away. The rock here is of a dark, 
greenish brown color, and breaks with a more or less distinct 
cleavage, owing to a rudely parallel orientation of the tabular 
plagioclase crystals. 

The plagioclase is dark brown in color and is beautifully 

_striated. Between the crystals are irregular patches of dark 
green or brownish green, finely crystalline, secondary silicates 
in which are very generally embedded lustrous grains of ilmen- 
ite. The green material can be seen to penetrate to some 
extent the feldspar substance. Polished surfaces, looked at 
with a good hand lens, serve to show the texture admirably. 
Outcrops in the southeastern part of the area show about the 
same degree of metamorphism, although superficial alteration 
has gone further. On exposed surfaces the feldspar becomes 
chalky and retreats, leaving the black ore grains and their 
matrix of secondary silicates, now of a dull, pale green color, 
standing out in relief. ree, 

More severely metamorphosed phases may be recognized by 
the fact that a portion of the feldspar has changed to a dull 
white saussurite, a change that becomes complete in the more 
extreme types. The latter are also characterized by the 
diminished nmnber and size of the ore grains and by the 
general loss of the original texture. Types representing these 
stages may be collected a little east of the exposures of the 
least altered type above alluded to, and from the ledges on the 
north and south of the railroad track. ‘Toward the northern 
border of the area and along portions of the high ridge that 
forms the eastern outcrop of the gabbro toward the Iron Mine 
Hill, the rock has lost, so far as its macroscopic appearance is 
concerned, almost every vestige of its original texture. It 
shows an indistinct schistose structure, and has a mottled, 
greenish white appearance. Chlorite, a little sericite and an 
occasional remnant of ilmenite and feldspar are the only 
minerals that can be distinctly identified, although the dull 
white dense groundmass, especially in its weathering, is sug- 
gestive of a feldspathic composition. At the contact with the 
granite and schists on the north, the gabbro has been sheared 
into a fissile green schist. At the extreme northeast extension 
of the outcrops the rock has become a greenish white, fissile 
schist. 


472 0. H. Warren—Alteration of Augite-Limenite Groups. 


Microscopic characteristics of the gabbro—least metamor- 
phosed types.—In addition to this being the least altered of 
any of the types examined, it may be designated as one whose 
chief distinguishing features are a large development of 
secondary biotite and the absence of leucoxenic alteration of 
the ilmenite. In thin section the feldspar substance is com- 
paratively fresh although occasional patches of sericitic and 
saussuritic material may be noted, and the crystals are generally 
characterized by the presence of a brown pigment. The ecrys- 
tals show abundant evidence of mechanical strains. 

The augite appears to have been the first constituent. that 
vielded to alteration, and although by far the greater portion 
of it has gone over to secondary minerals, occasional crystals, 
may still be seen in intermediate stages of alteration. In the 
thin sections studied, the dominant mode of alteration (if not 
indeed the only one in this type) is to a more or less confused 
fibrous aggregate of hornblende. Under low powers this has 
a cloudy appearance and is of a light yellowish brown color. 
With higher powers the fibers have a sub-parallel, also some- 
what divergent arrangement, and possess in general a pale 
green or yellowish green pleochroism. The change to this sub- 
stance begins about the edges, along cleavages or fractures, 
and encroaches in. a quite irregular manner on the augite sub- 
stance. The’amphibole often assumes a distinetly greenish or 
bluish green color next the plagioclase. Instances may also 
be noted where the whole aggregate has a more compact tex- 
ture while at the same time the color is a deeper brown. 
Small crystals of a yellowish to reddish brown, massive horn- 
blende may also be seen, which are undoubtedly secondary 
and strongly suggestive of a direct formation from the augite. 

The change of the augite to the fibrous form is followed by 
a further and more important change, which often begins 
before the original augite has entirely disappeared and in 
which are involved reactions with constituents from the ilmen- 
ite and plagicclase. The space originally oceupied by the 
augite as well as a part of that occupied by the ilmenite and 
plagioclase becomes filled with an aggregate composed of 
hornblende, biotite and particles of ore, the latter largely 
residual although possibly to some extent secondary. Where 
augite grains unaccompanied by ilmenite have suffered altera- 
tion, biotite is characteristically lacking. 

This hornblende is strikingly different in appearance from 
the fibrous form previously described, and consists essentially 
of an aggregate of small prismatic crystals and fibers exhibit- 
ing a distinct, though not very strong, bluish green pleochroism. 
Associated with this is a variable amount, often considerable, 
of hornblende in the form of prismatic crystals of relatively 


C. H. Warren—Alteration of Augite-Llmenite Groups. 478 


large size and possessed of a strong, bright blue pleochroism, 
parallel to C. Near the borders of the aggregates they are 
more abundantly developed, in fact they not infrequently 
form a distinct border of blue prisms jutting out into the 
plagioclase. Crystals of hornblende having a yellowish to 
reddish brown pleochroism parallel to C occur with the blue 
and appear to have been formed in the same way, indeed the 
same crystal may show a blue pleochroism in one portion and a 
brown in another. Both the blue and the brown variety may 
also be seen, changed, probably by a bleaching process, to a 
nearly colorless variety. Within the aggregates there appears 
to be some actinolite. 

The biotite is of a light brown color and its formation is 
clearly connected with the presence of ilmenite. It occurs in 
part in the form of flakes or shreds mingled with the horn- 
blende. Its amount varies, being most abundant in the 
neighborhood of the ilmenite, where it not infrequently prac- 
tically displaces the hornblende. Its most striking mode 
of occurrence is, however, in the form of a clearly marked 
border lying between the hornblende and the plagioclase. 
These borders as a rule practically surround the entire altered 
area. Their width, relative to that of the area enclosed, varies 
considerably in different cases but is always large (perhaps 
from 1/5 to 1/12). The border consists essentially of narrow 
shreds or flakes, orientated perpendicularly to the contact with 
the feldspar, into which they penetrate quite irregularly. Blue 
hornblende (rarely brown) prisms frequently make their appear- 
ance in these biotite rims, and, in places, as noted above, may 
actually constitute a rim themselves. 

Needles and stouter prisms of hornblende often accom- 
panied by biotite are abundantly developed along fractures 
and cleavages in the feldspars, while minute isolated horn- 
blende crystals are to some extent disseminated in many of the 
plagioclase crystals (gewanderte hornblende). A small amount 
of calcite and limonite is also present. 

Both biotite and hornblende have been noted lying directly 
in contact with the ilmenite; of the two, biotite seems, how- 
ever, to be much the most intimately connected as regards 
formation with the ilmenite. It sometimes forms a continuous 
. erystal about a portion of or even an entire ore grain. In 
such cases the biotite often contains a considerable amount of 
included material in the form of minute grains, for the most 
part opaque but sometimes feebly translucent. Some which 
show a reddish color are probably rutile. These particles are 
undoubtedly residual since every gradation between biotite 
with only a small amount of included matter and that contain- 
ing a core of massive, unchanged ilmenite, may be seen. It 


474 OC. H. Warren— Alteration of Augite-Llmenite Groups. 


is in fact generally evident from the relations of ilmenite to 
the secondary silicates, that a very considerable portion of the 
former has disappeared through reaction. It is to be par- 
ticularly noted that leucoxenic alteration of the ilmenite is 
absent in this type. Neither have the oxides of titanium 
been observed to more than a trifling extent. The appearance 
of characteristic aggregates of secondary hornblende and 
biotite with residual ilmenite is shown in the accompanying 
photograph. | 


Summary of the mineralogical changes.—After the first 
change of the augite to the fibrous (or compact) hornblende 
there appears to have been a profound readjustment of the 
various constituents of the hornblende, ilmenite and surround- 
ing plagioclase, accompanied by reerystallization and more or 
less transportation, possibly removal, of material. The par- 
ticular chemico-mineralogic changes which may be noted here 
are: 1. The formation of a blue, soda-iron or soda-aluminum 
amphibole molecule from the soda (and alumina?) of the plagio- 
clase and from the ferric iron of the ilmenite. The brown 


C. H. Warren—Alteration of Augite-llmenite Groups. 475 


variety may well be due to the entrance into the molecule of a 
different proportion of ferric iron and titanium. 2. The for- 
mation of biotite, for which both ferrous and ferric iron were 
derived from the ilmenite, alumina and alkalies from the 
feldspar, and perhaps magnesium from the augite or fibrous 
hornblende. The titanium, originally combined with the iron 
used up in the formation of biotite, probably also enters into 
this latter mineral; at all events, leucoxene or other titanium. 
bearing minerals are absent. 

The water given off by the rock on intense ignition reacts 
acid, indicating the presence of fluorine. This is probably 
present in the hornblende and biotite and it is possible that it 
may have originally been derived from emanations from the 
adjoining granite intrusives, which are believed to be later than 
the gabbro and are known to contain considerable fluorite in 
places. The effect of even an exceedingly small amount of 
fluorine in promoting changes like those recorded here would 
be unquestionably great and is worthy of consideration. 

The occurrence of secondary biotite and hornblende about 
magnetite or ilmenite associated with augite in a manner which 
appears somewhat similar to the one described here, has been 
noted very briefly by Mr. 8. Allport in an article “On the 
Metamorphic Rock Surrounding Land’s End Mass of Granite, 
Tolearn.”* Mr. Allport describes brownish spots having the 
mode of occurrence of magnetite and containing centers of 
magnetite ‘surrounded by innumerable minute flakes of brown 
hornblende or mica, while a short distance is usually green—a 
fact clearly indicating the diffusion of ferric oxide.” Again, 
“ Augite was abundant and has been converted into a brown 
granular substance.” Dr. G. H. Hawes, in “The Mineralogy 
and Lithology of New Hampshire,t descr: and figures mag- 
netite or ilmenite grains surrounded by folie of biotite radially 
arranged in fan-shaped aggregates with the iron oxide as a 
nucleus, as of very common occurrence in the “syenite”’ near 
Jackson, N. H. He expresses the opinion that biotite may be 
very commonly a secondary product of this kind. Again, 
Wadsworth recognized it as a secondary mineral developed 
irom magnetite or ilmenite and the surrounding feldspar and 
more rarely from pyroxene, in some of the gabbros described by 
him from Minnesota. Dr. Wadsworth also notes its occurrence 
as a secondary mineral from titanic iron ore and plagioclase in 
the basic titaniferous rock from Taberg, Sweden, and in the 

* Quart. Jour. Geol. Soc., xxxii, p. 420, 1876. Also referred to and figured 
by Teall (British Petrography, plate xvii). 

+ Geology of New Hampshire, C. H. Hitchcock, 1878, Part IV, p. 205, fig. 6, 


plate xi. 
¢ Gtol. and Nat. Hist. of Minn., Bull. No. 2, St. Paul, pp. 65 and 90, 1878. 


476 OC. H. Warren—Alteration of Augite-Ilmenite Groups. 


closely similar rock, cumberlandite (rhodose), from the present 
locality, a fact to which the present writer has more recently 
again called attention. Its occurrence has also been noted else- 
where, particularly in certain European “ Flascher gabbros.” 
Its development as a secondary mineral jointly from the con- 
stituents of ilmenite and plagioclase does not, however, appear to 
have received much attention in standard works on Petrography, 
although its importance as bearing on the presence of biotite 
in metamorphic rocks is obvious. 

The effect of superficial alteration of this type is a gradual 
change of the biotite (to some extent.the hornblende) to chlorite 
accompanied by the formation of epidote. Kaolin, calcite, and 
limonite also develop. 

Second type of altered gabbro.—This type may be character- 
ized, in distinction to the above, as one in which the ilmenite 
has suffered a leucoxenicé alteration as well as a biotitic and 
hornblendic one, and in which the augite, besides a passage to 
the fibrous aggregate, shows a direct change to a more or less 
compact green, or brown hornblende. Specimens of this type 
have evidently suffered more severely from shearing. The 
feldspar crystals are frequently crushed and are very generally 
filled with saussuritic material, in addition to secondary silicates 
more directly derived from the alteration of the augite and ore. 
The saussuritic material consists essentially of epidote and 
zoisite with some muscovite and hornblende. 

The change of the augite to the same fibrous aggregate as 
previously described may be seen clearly and is unquestionably 
a common one inthis type. Another change, sometimes in the 
same crystal, to a semi-compact pale, bluish green hornblende, 
which assumes a deeper blue color where it is in contact with 
the plagioclase, is of frequent occurrence. This hornblende 
examined with high powers shows an indistinct reedy structure 
and is filled with minute crystallites of other minerals, iron 
oxides and epidote chiefly. Irregularly throughout its mass, 
somewhat divergent fibrous patches may be noted which in 
color and appearance seem to be identical with fibrous amphi- 
bole formed directly from the augite. 

These may result directly from the alteration of the green 
hornblende or perhaps simultaneously with it from the augite. 
A massive reddish to yellowish brown hornblende may also be 
seen forming directly from the augite. The brown hornblende 
very often passes sharply in a bright blue variety and also intoa 
practically colorless mineral which seems also to be an amphibole 
in its character although its double refraction is abnormally 
low. The fibrous secondary hornblende formed directly from 
the augite, the green and the brown hornblende, as well as the 
colorless amphibole, all suffer a further change into a confused 


C. H. Warren—Alteration of Augite-Llmenite Groups. ATT 


ageregate of hornblende prisms exactly lke that noted in the 
previous type. Biotite has also formed in the same manner 
but both the hornblende and the biotite, particularly the latter, 
have suffered a more general distribution through the rock and 
are less closely confined to the place of original formation. 
Much of the biotite and hornblende has now ‘suffered further 
alteration to chlorite. 

Leucoxene is abundantly developed about the ilmenite and is 
plainly of later origin than the biotite and hornblende. It is 
distinctly crystalline and has the characteristics of titanite. 
This leucoxenic alteration has brought out with great clearness 
the reticulate structure of the ilmenite. 

In comparing what have here been called the two types of 
alteration, the writer is led to conclude that the former is one 
brought about under conditions of deep-seated, hydrothermal 
action but unaccompanied by extreme shearing and crushing. 
In the second type generally similar changes obtained for a 
time but were succeeded by others induced by more severe 
local dynamic action. The latter changes are: The forma- 
tion of leucoxene; a greater tendency for the augite to pass 
directly into a compact or semi-compact hornblende ; increased 
saussuritization of the feldspar ; and a more general distribution 
of the secondary hornblende and mica throughout the rock. 

More highly metamorphosed types.—F urther metamorphism 
and alteration of the gabbro presents little that is novel, and a 
very general statement will suffice. The microscope reveals 
increased crushing and saussuritization of the feldspar, a com- 
plete change of the hornblende and biotite to chlorite and 
epidote, an almost complete alteration of the remaining ilmenite 
to leucoxene, and the development of some sericite. Some- 
secondary quartz and recrystallized feldspar may also be noted. 
A more or less schistose arrangement of the constituents 
becomes evident and the outlines of the original structures are 
less and less distinct, until in extreme phases, from near+the 
northern contacts, the slides show little more than a schistose 
mass of finely crushed feldspar mingled with secondary products. 


Laboratory of Mineralogy and Petrology, 
Massachusetts Institution of Technology, Boston, Mass. 


478 T.. Holm—Studies in the Cyperacee. 


Art. XLV.—Studies in the Cyperacee; by Turo. Horm.— 
XXVI. Remarks on the structure and affinities of some of 
Dewey’s Carices. (With 24 figures drawn from nature by 
the author.) 


Amone the circa eighty Carzces, which Dewey described, 
there are some which have proved very troublesome to caricolo- 
gists. The diagnoses are not always so complete or exact as 
they might have been written ; or the material on which certain 
species were founded was not quite mature, thus the reader 
does not always receive a very clear impression of tle most essen- 
tial characteristics of some of these species, even if they may 
be perfectly distinct and valid. In such cases, where we cannot 
depend entirely upon the diagnosis, the examination of Dewey’s 
own specimens may, sometimes, be helpful. But unfortunately 
the material left by Dewey is not only small, but it contains, 
moreover, specimens which are not all in conformity with his 
diagnosis, and such specimens must consequently not be looked 
upon as his original, those on which he founded his new 
species. The best set of Dewey’s species is in the herbarium 
of Kew; these specimens were named by Dewey himself and 
presented to Boott. There is, furthermore, some material at 
present incorporated in the Gray herbarium at Cambridge, 
which is very valuable so far as we are able to distinguish 
between those plants that were parts of his original specimens 
and others, which he simply identified as beg identical, but 
which, sometimes, are very different species. Dewey did not 
work with types, he worked with species, and naturally 
expected that his species were to be identified by means of the 
diagnoses. It would be very unsafe and unjust to give prefer- 
ence to the specimens in case of determination, instead of to 
the diagnosis. When Dewey’s specimens do not agree with 
the ‘diagnosis, we may feel sure that they were not correctly 
named. Much confusion has arisen from the attempt of 
certain authors to identify species by means of “ supposed 
types,’ especially when a critical examination of the diagnosis 
necessarily must convince us that said specimens were not the 
original, not the one on which the species was established. 
The interpretation of Allion’s Carex fusca and bipartita is a 
good example of the result of this kind of verifying old speci- 
mens,* but several other cases might easily be recorded.t 

* This Journal (4), vol. xvi, p. 145, Feb., 1908. 

+ The following note, copied from a letter received from Mr. Clarke, may 
be of interest to the reader: ‘‘ Willdenow did not work from types but 
from small packets (now largely sorted into different species in the Berlin 


Herb.). You can see this, because Kunth repeatedly cites Willd., folio 2 or 
folio 8, for species which he sets up as new (or separate). Feb. 24, 1902.” 


T. Holm—Studies in the Cyperacee. 479 


Now in regard to Dewey’s species, it is our intention to 
demonstrate that some of these have been misunderstood ; that 
some of these are not so difficult to identify, if we give prefer- 
ence to the diagnoses, and not to the specimens extant. It 
appears to the writer that the reprinting of the original diag- 
noses may be necessary, inasmuch as some of these are not known 
to several caricologists, who have no access to the earlier vol- 
umes of this Journal, in which they were published. But what- 
ever importance may be attached to the present supplemental 
notes on these species, we must not forget to mention that we 
owe much information to a prolonged correspondence with the 
late cyperographer C. B. Clarke of Kew, who was so very 
familiar with the large herbarium of Boott and many others. 
The modern method of identifying species by means of “ sup- 
posed types’ was, according to Clarke, a most dangerous 
experiment, since in particular respect to Carices neither 
Dewey nor Boott worked with types. In a note on Carex 
Tolmiei Boott,* Clarke has shown how very difficult it may be, 
sometimes, to reach an exact conclusion even from a work so 
excellently written and illustrated as that of Boott: Lllustra- 
tions of the genus Carex.+ The species of Dewey which we 
intend to discuss are: C. petasata, C. Barbare, C. magnifica, 
C. Schottii, C. petricosa and C. mirata. Of these C. petasata 
has been suppressed entirely, as will be shown in the subse- 
quent pages; C. Barbare, C. Schottii and C. mirata have 
either been referred to other plants, or have been merged into 
each other as synonyms; C. magnifica was never described, 
but mistaken for C. Sitchensis Prescott, while C. petricosa 
was known only from very immature specimens. With the 
exception of (. Barbare of which there is no material in Kew, 
but in Cambridge, we have had the opportunity to compare 
the others with authentic specimens, authentic to the full 
extent of the word, since they were in accordance with the 
original diagnoses; this material was made accessible to the 
writer through the kindness of Mr. Clarke. In regard to @. 
Barbare a young, but nevertheless quite complete, specimen 
named by Dewey in the Gray herbarium was loaned to the 
writer; beside that we succeeded in finding some mature 
specimens of this very rare species in the collections of Mr. 
Parish, now deposited in the U. S. National Museum. 

* Journ. Linn. Society, vol. xxxv, p. 403. 

+ ‘‘ Boott has named in his own hand many Carices in the herbarium and 
X takes these as ‘authentic’; but they are, in very many cases, authen- 
tically wrong. In his herb. propr., Boott usually pasted down, all mixed 
together, 3, 4 or even 7 collections on one sheet. His figures often include 
utricles from several ecltsekions: to show his idea of the. range of variation 

‘in each species.’ If, however, the utricle varied really to the degree he 


depicts it, it would be of very little use in diagnoses of species” (C. B. Clarke 
in litteris, Oct. 11, 1899). 


480 7. Holm—Studies in the Cyperacee. 


Carex petasata Dew. 


According to Professor Bailey deve. p. 52) “the original 
sheet of this species is in Herb. Torr. It contains three plants: 
C. lagogina Wahl, C. festiva Dew., and C. Liddoni Boott, 
to all of which Dewey’s description will equally apply.” For 
this reason Professor Bailey does not think that C. petasata 
‘‘ean be pressed into service,” and although as he states him- 
self, ““C. Presliz is not clearly accounted for,” and “ the original 
does not exist, either in the coilection of Presl or Steudel,” he 
nevertheless adopts Steudel’s name “in lieu of any other.” It 
may be that the specimens in Torrey’s herbarium were mixed, 
but there are several good examples ot C. petasata in Boott’s 
herbarium, received from Dewey and authenticated by his 
hand, and Mr. Olarke has informed us that these specimens 
are not mixed. Consequently there is. no reason why the 
name petasata should not be retained for this species, and the 
diagnosis written by Dewey* reads as follows: 

“Spicis distigmaticis androgynis, inferne staminiferis subqua- 
ternis ovato-oblongis cylindraceis subsessilibus approximatis ; 
fructibus lato-lanceolatis utrinque acutis rostratis vel acuminatis 
ore bifidis subalatis, squama lato-ovata subobtusa longioribus. 
Culm 4-8 inches high, erect, slightly scabrous, triquetrous, 
striate; leaves shorter below, upper one about as long as the 
culm ; spikes androgynous staminate below, oblong cylindric, 
about 4, short pedunculate, approximate, brownish; fruit 
broad lanceolate, acute at each end, acuminate or rostrate, 
compressed, bifid and slightly winged, convex above; scale 
ovate, obtusish, tawny, broad, shorter than the fruit. Found 
on the Rocky Mountains.” 

Characteristic of the species is, thus, the ovate-oblong spikes, 
which are short peduncled and approximate, but not sessile, 
forming a head; moreover the broadly lanceolate perigynia 
tapering at both ends, and narrowly winged. Frequently the - 
spikes, especially the lower ones, are somewhat remote, very 
distinctly peduncled and subtended by setiform bracts, thus 
resembling C. pratensis Drej..—The perigynia are light brown 
and faintly, though very distinctly, veined (about six veins on 
the outer face). It would consequently be very unjust to con- 
sider the specimens in Torrey’s herbarium as being Dewey’s 
type. In the first place because Dewey did not work on types, 
and secondly because his diagnosis by no means applies to the 
three species which Professor Bailey found in said herbarium. 
This may be readily seen from the fact that so far as.concerns 
C. lagopina, the perigynia of this species are ovate to almost 
round, and never winged; in C. festeva the spikes form a 


* This Journal (1), vol. xxix, p. 246, 1836. 


T. Holn—Studies in the Cyperacee. 481 


dense head, and the perigynia vary from ovate to suborbicular, 
broadly winged and prominently veined; in C. Lzddonz the 
very heavy spikes and large perigynia, which are many-nerved 
and with prominently serrulate- -winged margins, make this 
species very distinct from C. petasata. In regard to the 
geographical distribution C. petasata has been found in Alaska, 
but only in a few localities; furthermore and apparently fre- 
quent in the mountains of Washington, Oregon and Idaho, 
in the Alpine regions; it occurs, also, in British Columbia, 
Alberta, Assiniboia, Vancouver Island, Montana, Wyoming, 
Utah and Colorado; it seems to be rare in Colorado, and is 
there confined to the highest peaks above timber-line. 


Carex Barbare Dew. 


Through the kindness of Mr. M. L. Fernald the writer has 
had the opportunity to examine probably the only specimen 
extant from Dewey’s own material of this very rare species, 
deposited in Win. Boott’s herbarium, now incorporated in the 
Gray herbarium at Cambridge. It is an immature specimen, 
but labeled by Dewey himself: “ C. Barbare, Santa Barbara, 
New Mexico,” and the principal characteristics are easily rec- 
ognized to be in conformity with the diagnosis, as this was 
written by Dewey.* Subsequent authors have not, however, 
paid due attention to the original diagnosis, for instance, the 
peculiar structure of the squamee, and the result has been that 
Carex Barbure of to-day comprises several distinct species, 
among which Dewey’s C. Schott and C. dives nob. While 
thus the specimen, which we have examined, is immature, the 
diagnosis plainly shows that Dewey based his description on 
more perfect and mature specimens; if not he would have said 
so, for he was careful enough to state in his diagnosis of C. 
Schottéi that the perigynia were either wanting or We ge: 
To deal with immature specimens of Carices especially is 
most difficult task, but, in the present case, we have a well 
written diagnosis beside a specimen labelled by the author him- 
self. It seems very strange that so much confusion should 
arise in regard to the identity of this species, since the group 
of OCarices to which it belongs is rather poor in representatives, 
and, as stated above, so very distinct from that to which the 
other plants belong, which erroneously have been referred to 
C. Barbare. From reading Dewey’s diagnosis there is abso- 
lutely no doubt that his Curex is a member of the orasta- 
chye, and related somewhat to C. Schotti and C. magnifica, 
which he distributed under this name though without append- 
ing a diagnosis. Most of the species which subsequent authors 


* Emory’s Report U. S. and Mex. Bound. Survey, p. 281, 1858. 


482 LT. Holm—Studies in the Cyperacee. 


have named C. Larbare are members of the grex Microrhyn- 
che, and more or less closely related to Prescott’s C. Sttchen- 
sis. It seems a strange coincidence that this species of Prescott 
should suffer the same fate as C. Barbarw, to become so 
entirely misunderstood for many years, although the diagnosis 
plainly shows us that it was not intended for the very char- 
acteristic C. magnifica of Dewey. When thus modern eari- 
cographers consider C. LBarbare to be a close ally of C. 
aquatilis Wahlenbg., we are now in the positicn to state that 
it is not by any means related to this, neither to this particular 
species, nor to any of the other members of the ALicrorhynche. 
Inasmuch as the real C. Barbare seems to be a very rare 
plant (not represented in any of the large herbaria at Kew) it 
might be appropriate to reprint the original diagnosis, and to 
give an account of the confusion into which the species has 
fallen. Dewey’s description reads as follows: “ Carex Bar- 
bare Dewey: spicis staminiferis terminalibus 2 raro 3 erectis 
cylindraceis, suprema longe pedunculata, inferiore breviore illi 
contigua, infima sub-elongata; pistilliferis 3 longo-cylindraceis, 
2-4 uneialibus gracilibus, superiore apice staminifera brevi- 
bracteata erecta, inferioribus, longioribus, subremotis, subrecur- 
vis basi laxifloris brevi-vaginatis foliaceo-bracteatis, omnibus 
nigro-purpureis, perigyniis distigmaticis oblongis obovatis api- 
culatis ore integris, squama oblongo obovata dorso pallida 
mucronata brevioribus; culmo erecto glauco longe-foliato vagin- 
atoque. Danks of streams, Santa Barbara, California ; Parry.— 
Culm 16-20 inches high, erect, with long leaves towards the 
base and long leafy bracts above, glaucous; spikes 3-6, eylin- 
dric, slender, blackish purple; staminate terminal 1-3, com- 
monly 2, the upper nearly two inches long, peduneulate, the 
lower sessile, contiguous and shorter, the third longer than the 
last and more remote; pistillate 3, long cylindric, 2-4 inches 
long, slender; the upper staminate at the apex, short-bracteate, 
erect ; the lower longer, subremote, subrecurved, loose-flowered 
at the base and short-sheathed; perigynium oblong-obovate, 
short-rostrate, entire at the orifice, stigmas 2, pistillate scale 
oblong-obovate, on the back pale, and the nerve extended into 
a mucronate point, making the end of the scale sometimes 
emarginate. The locality gives the name of the species,” 
Some mature specimens of C. Barbare Dew. have been col- 
lected by Mr. Parish in San Bernardino Mountains,* and by 
examining these we noticed that the perigynia exhibit several 
very fine nerves, which must have been overlooked by Dewey ; 
otherwise these specimens showed exactly the same habit and 
structure of squamee as Dewey’s own specimen. It is to be 


* Southern California, alt. 3000 ft.,S. B. Parish, No. 3276, deposited in 
the herbarium of U. 8. National Museum. 


T. Holm—Studies in the Cyperacee. 483 


remembered that the minor structure of the perigynium in 
Carex is seldom noticeable in the dried state, but readily visi- 
ble in fresh material or by soaking the dried specimen in boil- 
ing water and alcohol. In pointing out some of the most 
striking characters of this species we might mention: the long 
and slender, blackish purple spikes, the oblong-obovate, mucro- 
nate squamie, sometimes emarginate, which are longer than 
the faintly nerved, oblong-obovate perigynia; furthermore the 
short beak with entire orifice. 

Let us now consider some of the other plants which formerly 
have been referred to C. Barbare, but which we believe are 
distinct from this. There are, for instance, in the Gray herba- 
rium some specimens, and very well represented, of a Carew, 
which are named C. Garbarw in Dewey’s own handwriting; 
they are from Hayden’s collection and the localities are given 
as: “Lake Fork, 6,000 ft. above the sea, also on Madi- 
sons aver,” -“ and near Fort! (the name written very indis- 
tinctly), high on Rocky Mountains.” <A note attached to these 
specimens and signed 8S. T. O. (Stephen T. Olney) reads: 
“These specimens are unlike those so named in Mex. Bound. 
Survey. Doctor Dewey had marked one of these (the former) 
C. stricta Good., to which they possibly belong.” We can 
only agree with Olney that these specimens are quite distinct 
from C. Barbare vera, but we prefer to place them under C. 
Nebraskensis Dew. var. previa Bail. In his treatment of 
Carex 1a King’s Report,* Olney referred C. Barbare to F. 
Boott’s C. Prescottiana,t as a synonym, but Boott’s species is 
very different from that of Dewey; it, also, deserves notice 
that Olney in the same paper refers C. Sitchensis Dew. not of 
Prescott as synonym of C. laciniata, which shows very plainly 
that Olney was not acquainted with the real 0. Sitehensis 
Prese., but that he mistook (©. Sitchensis Boott for this 
species, while Dewey segregated Hooker’s and Boott’s C. 
Sitchensis as his C. inagnifica. Another specimen which is 
also incorporated in the Gray herbarium is by Dewey labelled 
C. Sitchensis Prese.; it was collected by Professor Wood in 
swainps near Los Angeles, California. This specimen differs 
from CU. Barbare by the pistillate squame being merely acute, 
the midvein being not excurrent, besides by the shortness of 
the scales in proportion to the perigynium; from typical C. 
Sitchensis this specimen differs only by the presence of a few, 
faint nerves on the outer face of utriculus. Professor Bailey 
has, nevertheless, identified this plant as representing C. Bar- 
bare. While Mr. Parish had the good fortune of rediscover- 

* U.S. Geol. Explor. of the 40th Parallel, p. 361, 1871. 


+ Caricis species nove, vel minus cognite. (Transact. Linn. Soc., vol. 
xx, p. 135, 1845-46. 


484 T. Holm—Studies in the Cyperacee. 


ing the rare C. Barbar, as stated above, he has also collected 
another species of very robust habit, which, however, does not 
appear identical with Dewey’s plant. As a matter of fact, 
this tall Carex distributed as C. Barbare* resembles much 
more the real C. Sitchenszs Prese., but the perigynia are dis- 
tinctly nerved, ver My large, and considerably longer than the 
squamee. If the perigynia had been smaller, merely two-nerved 
and scabrous along the upper margins, the species might have 
been referable to O. dives. 

In the herbarium of the U.S. National Museum we found 
several specimens identified by recent authors as C. Barbare 
Dew., but only the specimen mentioned above, collected by Mr. 
Parish (No. 3276) and some immature ones from Sanger, 
Fresno county, California, collected by Dr. J. W. Hudson, 
represent tlis species; the others were C. amplifolia Boott, 
C. Schottii Dew., C. laciniata Boott, ete. 

As received by Professor Baileyt C. Barbare should be 
identical with C. Schottic Dew., which actually is C. obnupta 
Gail., furthermore with the plaut which Dewey himself bad 
called CO. Sitehensis, and with a third species from Washing- 
ton and Vancouver Island, which by the writer has been 
described as C. dives.t The fact that Professor Bailey con- 
siders C. Barbare a close ally of C. aguateilis Wahl. is a sad 
illustration of how easily a good species might be lost sight 
of; because none of the allies of CO. aquatelcs Wahl. possess 
squamee and perigynia-of the structure as is characteristic of 
C. Barbare. We must admit, however, that the structure of 
both squamee arid perigynia is ‘somewhat variable in a number 
of Carices, and especially among Carices genuine ; the ner- 
vation of the perigynium is not always equally developed, and 
the apex of the squama may vary from acute to mucronate or 
even aristate. But, on the other hand, we do not remember a 
single instance where within the same species the apex of the 
squama varies from obovate, mucronate and sometimes emar- 
ginate to oblong-lanceolate and simply pointed ; for this rea- 
son the writer does not feel inclined to remodel the original 
diagnosis of C. Barbare in order to include the several more 
or less distinct’ species, as has been done by recent authors. 
According to our opinion, the specimen of Dewey’s own col- 
lection and those of Mr. Parish (No. 3276), which we have 
cited above, these are sufficiently instructive for demonstrating 
the species as understood by Dewey ; all the other plants must 
be referred to other species. 

* Southern California: Damp land, meadows or swamps, alt. circa 300 m. 
San Bernardino Valley, No. 5981, March 9, 1907. 


+ Memoirs Torrey Bot. Club, vol. i, p. 44, 1889. 
t This Journal (4), xvii, p. 312, 1904. 


T. Holm—Studies in the Cyperacee. 485 


i 


Fie. 1, perigynium; fig. 2, pistillate scale; fig. 3, staminate scale of 
Carex Barbarcee Dew., from St. Barbara, identified by Dewey. 

Fic. 4, perigynium ; fig. 5, pistillate scale of C. Barbare from San Ber- 
nardino Mts., collected by Parish (No. 3276). 

Fie. 6, perigynium; fig. 7, pistillate scale; fig. 8, staminate scale of C. 
Nebrasi:ensis, from Lake Fork, collected by Hayden. 

Fic. 9, perigynium ; fig. 10, pistillate scale; fig. 11, staminate scale of 
Carex sp., by Dewey identified as C. Sitchensis Prescott from Los Angeles, 
collected by Wood. 

Fic. 12, perigynium ; fig. 13, pistillate scale; fig. 14, staminate scale of C. 
Sitchensis Presc. from Sitka, collected by C. V. Piper. 

Fie. 15, perigynium ; fig. 16, pistillate scale; fig. 17, staminate scale of 
C. dives Holm from Chilliwack Valley, collected by James M. Macoun. 

Fic. 18, perigynium; fig. 19, pistillate scale ; fig. 20, staminate scale of 
Carex sp. from San Bernardino Valley, collected by Parish (No. 5981), and 
described as C. Barbare (Bull. South Calif. Acad. of Sce., p. 108, 1905). 


The accompanying drawings (figs. 1-20) illustrate perigy- 
nia and scales of Carex Barbarew Dewey, and of some other 
species which by subsequent authors have been referred to this 
species. It is readily to be seen that the figures of Dewey’s 
own but immature specimen (figs. 1-3) agree very well with 
those collected by Mr. Parish (figs. 4-5); furthermore, that 
Dr. Hayden’s specimens from Lake Fork (figs. 6-8) are 
undoubtedly C. Webraskensis Dew. Then there is the plant 
which Dewey himself identified as C. Sitchensis Prese. (figs. 


Am. Jour. Sci.—FourtH Series, Vout. XXVI, No. 155.—Novemper, 1908. 
34 


486 T. Holm—Studies in the. Cyperacee. 


9-11), and which Professor Bailey has referred to C. Barbara. 
By comparing these figures with those of C. Barbare (figs. 
1-5), it seems not very difficult to see that they are not the 
same species. Dewey’s specimen of C. Sitchensis agrees well 
with the Sitka-plant (figs. 12-14), with the only difference that 
the latter lacks the nerves in the perigynium. In figs. 15-17, 
we see the perigynia and scales of a Carex from British Colum- 
bia, which Professor Bailey has also referred to C. Barbare; 
this northern plant we have described as C. dives, and it is 
certainly very distinet from C. Barbare Dew., but a near ally 
of C. Sitehensis Presc. Finally we have the very robust species 
from Mr. Parish’s collection (figs. 18-20), and this cannot pos- 
sibly be identified as C. Barbarew Dew. either ; it may repre- 
sent an undescribed species, unless it bea gigantic C. Sitchensis 
Prese. : 

In regard to C. Sitchensis Presc. we might state at the same 
time that our figures 12-14 were drawn from some material 
collected recently by Professor C. V. Piper, and that these 
specimens agree in all respects with authentic material in Bis- 
choff’s herbarium, which is now in the possession of the St. 
Louis botanical garden. 

Carex Barbare Dew. must be placed among the ora- 
stachye Dre}. on account of the long, nodding, dark-colored 
spikes, the broad mucronate scales and the glabrous perigynia 
with the orifice entire. 


Carex magnifica Dew. 


As stated in a previously published paper,* this species has 
for many years passed for C. Sitchensis Prescott, and described 
and illustrated by Boott} as representing this species. Several 
specimens were sent to Boott by Dewey under this name mag- 
nifica, but not accompanied by any diagnosis ; however, there 
being no other name or synonym for it, the name magnifica 
has been adopted by C. Bb. Clarke, and we now append the 
diagnosis, copied from Boott (1. ¢.) and based upon specimens 
from California : 

‘‘Spicis 5-8 cylindricis atro-purpureis, masculis 2-3 rarius 
4 sessilibus erectis, foemineis 3-5 superioribus conspicue (raro 
omnibus) apice masculis inferioribus pedunculatis erectis vel 
nutantibus evaginatis basi saepe laxifloris ; bracteis intferiori- 
bus culmum superantibus ; stigmatibus 2; perigyniis ovalibus 
v. obovatis vel subrotundis rostellatis biconvexis, ore integro 
glabris vel ad margines apice subinde parce denticulatis flavi- 
dis dense spongiosis, squama ovato-lanceolata acuminata acuta 


* This Journal, vol. xvii, p. 316, April, 1904. 
+Tll. genus Carex, vol. iv, p. 159, Pl. 518 and 519. 


T. Holin—Studies in the Cyperacee. 487 


vel aristata saepe obtusa metetda lineata, angustioribus duplo 
brevioribus.” 

This species has been collected in Alaska, British Columbia, 
Vancouver Island, Washington, Oregon and California ; it 
grows in marshy g oround, on borders of - ‘ponds, ete., and ascends 
to an elevation of. a: 500 feet in the Olympic mountains. 


Carex Schottii Dew. 


The latest disposition that has been made of this species is 
to regard it as identical with C. Barbare Dew., a suggestion 
proposed by Professor Bailey.* But from the statement by 
this author that C. Barbare is closely allied to C. aquatilis 
Wahlenb., it is evident that Professor Bailey has not had access 
to authentic material; moreover, the specimens cited from 
Vancouver Island and Washington do not agree at all with 
the diagnosis of C. Barbarew or of C. Schottii. On the other 
hand, the plant described as C. obnupta by Professor Baileyt+ is 
the real C. Schottia Dew. 

The diagnosis as written by Dewey? reads as follows : 

“Spicis staminiferis terminalibus 3-5 erectis nigro-rubris 
approximatis prope geminatis cylindraceis, superiore longa 
3--unciali medio inflata, inferioribus brevioribus sessilibus con- 
tiguis vel infima remotiore et interdum geminata ; pistilliferis 
3 raro 4 perlongo-cylindraceis gracillimis 6-8 uncialibus per- 
laxifloris ineequaliter pedunculatis, inferioribus longe peduncu- 
latis folioso-bracteatis basi vaginatis vix fructiferis vel abortivis, 
cum squamis oblongis aretis obovatis vix acutis; perigynio 
carente vel nimis immaturo; culmis superne scabris subpros- 
tratis cum foliis bracteisque ‘viridi glaucis. Banks and rivers, 
Santa Barbara, California; Parry.” 

Since then the species has been collected by: Bolander (No. 
1570) in salt marshes near Fort Point, Golden Gate, Califor- 
nia, and in. these specimens the perigynia are mature; the 
late Mr. C. B. Clarke identified Bolander’s specimens and it 
was through his kindness that the writer received mature speci- 
mens so as to ascertain the identity of Professor Bailey’s C. 
obnupta with the present species of Dewey. In Carex Schot- 
tiz the perigynia are shining, dark reddish brown, orbicular, 
shortly stipitate, glabrous, or with a small spine near the short, 
entire beak; the perigynium is much shorter than the oblong- 
lanceolate, pointed scale. 

The species is a near ally of C. magnifica, possessing the 
same very dark-colored spikes, the coriaceous perigynia, which 
are more or less orbicular and much shorter than the squama. 

* Memoirs Torrey Bot. Club, vol. i, p. 44, 1889. 


+ Proceed. Calif. Acad., vol. iii, p. 104, 1893. 
+ Emory’s Report U. S. and Mex. Bound. Survey, p. 231, 1858. 


488 T. Holm—Studies in the Oyperacee. 


Carex petricosa, Dew.* 


The original diagnosist reads as follows : 

‘‘Spicis subquaternis oblongis tristigmaticis, terminali andro- 
gyna superne staminifera, inferioribus exserte pedunculatis ; 
fructibus lanceolatis levibus acutis ore apertis, squama ovato- 
oblonga obtusiuscula brevioribus. 

Culm ten inches high, triquetrous, smooth, leafy towards 
the base, upper leaves as long as the culm; bracts leafy and 
sheathing ; spikes four, exsertly pedunculate, oblong, subre- 
mote; fruit lanceolate, smooth, with an open mouth; stigmas 


Fie. 21. Fruiting specimen of Carex petricosa Dew. ; one-third of the 
natural size. ; 

Fie. 22. The inflorescence of another specimen with five spikes ; one- 
third of the natural size. 

Fic. 25. Pistillate squama of same; magnified. 

Fic. 24. Perigynium of same; magnified. 
three, and upper spike staminate above; pistillate scale ovate, 
oblong, rather obtuse and longer than the fruit, reddish brown 
on the edge and whitish on the keel. Found on the summit 
of the Rocky Mountains.” | 

The specimens were collected by Drummond between lat. 
54°-56°, and according to Macount the locality must have 
been between the sources of the Athabasca and Peace. River. 
For many years the species was lost, and it is not until very 
recently that this very rare and interesting species has been 

* — C. invisa Bailey. + This Journal (1) xxix, p. 246, 1836. 

+ Catalogue of Canadian plants, Montreal, p. 158, 1888. 


T. Holm—Studies in the Cyperacee. 489 


rediscovered. Mr. N. B. Sanson found the plant on Rundle 
Mountain near Banff in Alberta, at an elevation of 6,000 feet, 
and growing together with Carex rupestris All. Through the 
kindness of Mr. James M. Macoun the writer has received an 
excellent suite of fully matured specimens, in which we have 
observed some characters which are not mentioned by Dewey; 
we remember that the material which Dewey described was 
not quite mature and only scantily represented. 

One of the most striking peculiarities in this species is the 
manner in which the staminate and pistillate flowers are dis- 
tributed. The number of spikes varies from two to five, but 
four seems to be the most frequent. As indicated in the diag- 
nosis “ spica terminali androgyna superne staminifera”’? Dewey 
did observe that both sexes were present in the terminal spike ; 
however he makes no mention of the other spikes, which he 
evidently took to be pistillate, as is the most frequent in this 
group of Carices. While thus an androgynous terminal spike 
appears to be typical of this species, it deserves notice that 
this spike is wholly staminate in small specimens. In regard 
to the other spikes the distribution of the sexes varies some- 
what, and may be illustrated by the following table : 


Terminal spike: mostly androgynous, seldom purely 
staminate. | 

Uppermost lateral spike: staminate, very seldom pistillate. 

Second lateral spike: pistillate or androgynous, very 
seldom staminate. 

Third lateral spike: pistillate, very seldom androgynous. 

Fourth lateral spike: pistillate, very seldom androgynous. 


There is thus a tendency of having the staminate flowers 
situated in a single spike below the “androgynous terminal, 
while the subsequent spikes are mostly pistillate or, sometimes, 
androgynous. Such irregularities in regard to the disposition 
of the flowers are not, however, uncommon in various greges 
of the genus. 

To the original diagnosis may, furthermore, be added that 
the perigynium (fig. 4) is hairy above and distinctly nerved 
(six or seven nerves on the outer face) when mature; the 
orifice is whitish, slit on the outer face, but entire on the 
inner. When fully mature the perigyninm is longer than 
the scale. As may be seen from the accompanying drawing 
(fig. 1) the rhizome is stoloniferous, and the slender culms 
are longer than the leaves; the basal spike is long-peduneled 
and drooping, while the others are sessile and appressed to the 
culm. 

The internal structure, which agrees with that of several of 
the other mountain species, may be briefly described as follows: 


490 T. Holm—Studies in the Cyperacen. 


The roots have no exodermis, but the cortex shows three 
very distinct zones: a peripheral, thin-walled and solid, inside 
of which are three strata of shghtly thick-walled stereome, sur- 
rounding an inner broad parenchyma of irregularly collapsed 
cells. Endodermis is moderately thickened all around, and 
the same structure occurs, also, in the pericambium, which is 
almost continuous, 3. e. only interrupted by two of the twenty- 
four proto-hadrome vessels. The leptome-strands are distinct, 
but very narrow. Inside the proto-hadrome are twenty wide 
sealariform vessels, which surround a broad central mass of 
thick-walled conjunctive tissue. 

The culm is obtusely triangular, glabrous and hollow; the 
cortex represents a very compact parenchyma of roundish. 
cells, but without palisades, and is interrupted by the stereome, 
which occurs as hypodermal strands bordering on the leptome- 
side of the mestome-bundles. These are arranged in a single 
triangular band surrounding a thin-walled pith, of which the eell- 
walls show very distinct spiral thickenings. 

The leaves are narrow, but flat, scabrous only on the ventral 
face from minute warts; the stomata, which are confined to 
the dorsal face of the blade, are level with epidermis and have 
a wide but shallow air-chamber. Wide lacunes traverse the 
chlorenchyma, in this species differentiated as a ventral 
palisade, and a dorsal pneumatic tissue of irregularly branched 
cells; there is, furthermore, a single layer of palisades 
around each vein, radiating toward the center of these. The 
stereome is not very thick-walled and occurs as hypodermal 
- strands and bordering on both faces of the veins; no isolated 
strand of stereome was observed in the leaf-margin. All the 
mestome-strands show the usual structure, being collateral 
and surrounded by a parenchyma- and a mestome-sheath. 
Although the plant grows in very dry, stony soil, the leaves 
have no water-storage tissue, but are able to close by means of 
a longitudinal band of typical bulliform cells, which are 
located above the midrib, on the ventral face of the blade. 

The anatomy of the Stenocar ‘pe to which our species belongs 
has been discussed by the writer in a previously published 
paper.* When comparing C. petricosa with these species it 
will be seen that its root-structure is quite different, since in 
the other species an exodermis is developed, besides that the 
peripheral strata of cortex are stereomatic, while in C. petricosa 
the stereomatic zone is located almost in the middle of the 
thin-walled cortex. The interruption of the pericambium by 
the proto-hadrome vessels is, on the other hand, a character 
that is common to most of these species. 

An obtusely triangular and glabrous culm is seldom met with 
in this grex but has also been observed in C. ablata. In regard 


* This Journal, (4), x, p. 278, Oct., 1900. 


T. Holm—Studies in the Cyperacee. 491 


to the leaf the structure agrees best with that of C. ferruginea, 
in which a typical palisade-tissue is developed; but while all 
the species examined possess an isolated strand of stereome in 
the leaf-margin, this was not observed in C. petricosa. The 
free position of the stomata being level with epidermis and 
not covered by papille is a structure which seems to be fre- 
quent among the Stenocarpe even if most of these are inhabit- 
ants of dry “soil among rocks; we have shown in the paper, 
cited above, how very little may be depended upon the struc- 
ture of the stomata as indicating the nature of the habitat. 
Moreover, this same free position of stomata was, also, observed 
in C. rupestris, which, as stated above, was found associated 
with C. petricosa. 
Carex mirata Dew. 


In a preliminary synopsis of North American Carices Pro- 
fessor Bailey* has referred this species to C. aristata R. Br., 
and in a subsequent paper by this same author} no further 
mention is made of this particular species. But we find in 
the latter of these publications a new species called C. exsic- 
cata Bail., said to be a near ally of C. vestcarzva L., though ‘in 
some of its forms strongly suggestive of O. tr ‘ichocanpa Muehl, 
var. aristata (R. Br.) Bail.’ No diagnosis is given, only the 
brief remark that C. exsiccata “ differs at once from €. vesi- 
caria by its greater size and broader leaves, thicker and more 
nearly sessile spikes, and particularly by the much longer, 
lance-ovate, scarcely inflated, duller and strongly nerved peri- 
gynium, which is three to four times longer than the very 
narrow and muticous scale,’ besides, as stated above, that it 
suggests C. aristata KR. Br. ; some varieties of C. vesicaria 
globosa Olney, major Boott and lanceolata Olney are referred 
to this new species (C. ewsiccata) as synonyms. 

Since then no suggestion has been offered as to the validity . 
of Dewey’s species, and the fact that Professor Bailey failed 
to append a diagnosis to his new species (C. exszccata), would 
naturally result in a possible confusion of both species, since 
Dewey’s diagnosis calls for a plant which is not so very remote 
from (. vesicaria. Some few years ago, when the writer was 
engaged in the preparation of a paper on “ Greges Caricum,” 
Professor ©. Piper kindly called our attention to the fact 
that Dewey’s diagnosis was very well applicable to a number 
of authentic specimens of C. exsiccata Bail. 

Carex mirata was first described in Wood’s Botany (1848), 
and although Carey? had not seen the plant, he nevertheless 
recognized it as a distinct species, placing it between C. Pseu- 
docyper us L. and C. hystricina Willd., quoting Dewey’s diag- 
nosis, and giving the geographical range as: Shore of Lake 

* Proceed Am. Acad. of Arts and Sci. p. 75, 1886. 


+Mem. Torr. Bot. Club, 1. ¢., p. 6. 
¢t Gray’s Manual, New York, <p. 531, 1857. 


492 T. Holm—Studies in the Cyperacee. 


Ontario, in Monroe County, New York, collected by Dr. 
Bradley. A more complete diagnosis was given by Dewey in 
1865,* which reads as follows: 

“Spicis 8-5, longo-cylindraceis incluse pedunculatis longe- 
folioso-bracteatis ; spicis staminiferis, 1-3 seepe 2, approximatis 
interdum ad_ basin. vel erga apicem pauco fructiferis cum 
glumis longis arctis attenuatis scavro-subulatis ; spicis pest. 1-2, 
laxifloris suberectis subremotis ad apicem vulgo staminifera ; 
fructibus parvi-ovatis longo-conicis vel lanceolatis vix inflatis 
nervosis vel striatis longo-stipitatis divergentibus rostratis, 
rostro profundi-fisso bicuspidato interdum bifureato vel biden- 
tato; glumis fructiferis lineari-lanceolatis scabro-subulatis, 
fructu superno spice brevioribus, fructum inferiorem gequan- 
tibus, atque fructus infimos plus duplo superantibus: culmo 
superne scabro, inferne obtusi-triquetri et levi; foliis bracte- 
isque nodosis et margine scabris.” 

It is to be regretted that Professor Bailey has not described 
his C. exsiceata in any other way than, as stated above, by 
merely alluding to the distinctive characters when compared 
with CO. vesicaria L., and this is not a diagnosis. However, 
the writer has had the opportunity of examining several speci- 
mens identified by Professor Bailey himself as representing 
C. exsiccata, and these specimens not only answer the diag- 
nosis of C. mirata Dew. in most respects, but they agree, 
furthermore, with some authentic specimens from Dewey’s own 
collection. When we use the expression “in most respects,” 
we wish to say that there are some points in Dewey’s diagnosis 
which we have not been able to observe in the specimens. 
This is for instance the case with “‘ fructibus longo-stipitatis,” 
for in the material at our disposal the perigynia were almost 
sessile ; moreover the pistillate spikes were not always “‘ laav- 
floris.” But the most important characters derived from the 
structure of the perigynium “ longo-conicis vel lanceolatis vix 
inflatis nervosis vel striatis” these were readily observed in the 
so-called C. exsiccata. Carex mirata belongs to a group of 
species, Physocarpe Drej., in which a notable variation occurs 
in regard to the number, position, and length of the spikes, the 
staminate as well as the ‘pistillate ; also in regard to the struc- 
ture of squama even in the same spike, not speaking of the 
oritice of the perigynium which, as Dewey has remarked him- 
self, may vary from deeply cleft to merely bidentate. For 
this reason (, mirata Dew. may not be recognized without 
some difficulty, while, on the other hand, it would be utterly 
impossible to distinguish C. ewseccata Bail. except by means 
of specimens, since no diagnosis has been published. 


Brookland, D. C., May, 1908. 
* This Journal (2), xxxix, p. 39, 1865. 


‘psy 


H. A. Bumstead—Lorentz-Fitz Gerald Hypothesis. 493 


Art. XLVI.—Applications of the Lorentz-Fitz Gerald Hypoth- 
esis to Dynamical and Gravitational Problems; by H. A. 
BuMSTEAD. 


THERE is at the present time a general consensus of opinion, 
among those best qualitied to judge, that the fundamental facts 
of optics and electro-dynamics require us to assume that the 
ether does not partake (to any sensible extent) in the motion 
of material bodies which pass through it. The aberration of 
light is perhaps the most conspicuous of those phenomena 
which it has hitherto been found impossible to account for on 
any other hypothesis without becoming involved in serious 
dithiculties.* All the phenomena in which there is relative 
motion of the source of hght with respect to the observer, or 
of a material medium (through which light is propagated) with 
respect to source and observer, appear to require the above 
assumption, even those which at first seemed to lead to a con- 
clusion somewhat different in form. Thus the experiment of 
Fizeau, in which he compared the velocities of light when 
going with, and against, a stream of water, was inter preted by 
Fresnel as indicating a certain entrainment of the ether. This 
interpretation was based on Fresnel’s theory of refraction, which 
assumed that the etherial density was increased in material 
media; and it is only the excess ether which must be carried 
by the matter. On the electron theory, however (and indeed on 
any resonance theory of dispersion and refraction) there is no 
excess density of the ether in ponderable bodies; and it is not 
difficult to see that Fizeau’s experiment requires a stationary 
ether.t A result which leads to the same view has been 
obtained in electro-dynamics by H. A. Wilson} in measur- 
ing the electric force produced by moving an insulator in a 
magnetic field. All such experiments upon the effects of rela- 
tive motion, so far as I know, give positive results which may be 
predicted from the hypothesis of a fixed ether, and the magni- 
tude of the oe observed is in general of the same order as 


the fraction = where v is the relative velocity involved, and 
V the velocity of light. 

The theory of a staynant ether leads ‘us, however, in a no less 
direct manner to expect certain modifications in the phenomena 
of light and electricity when there is no relative motion of 

* Larmor, Aether and Matter, p. 37. Lorentz, Amst. Proc., p. 448, 1899 ; 
Abhandlungen, I, p. 404. 

+ See Lorentz, Versuch einer Theorie der Elektrischen und Optischen 


Erscheinungen, in Bewegten Korpern, § 68. 
¢ Proc. Roy. Soc., lxxiii, p. 490, 1904. 


494 H. A. Bumstead—Lorente-Fite Gerald LHypothesis. 


material objects, but when all the apparatus concerned as well 
as the observer are carried through the ether with the velocity 


v. The effects to be expected are of the order of eS Beis) is 


is a very small fraction even when v is the velocity of the earth 
in its orbit, but the possible accuracy of certain optical experi- 
ments is so great that these effects could certainly be found if 
they existed without some compensating effect to mask them. 
As is well known, these effects have never been found; the 
first conclusively negative results were obtained in the cele- 
brated experiments of. Michelson and Morley,* and several 
other optical investigations have also failed to show the expected 
results. On the electrical side the problem has been attacked 
by Trouton and Noble,t who hung up an electrical condenser 
by a torsion wire and looked for a torque which, on the theory 
of a stagnant ether, ought to exist when the condenser is car- 
ried along by the earth. Although the sensitiveness of their 
experimental arrangement was ample for the observation of 
the expected second order effect, their result was also negative. 

The most obvious interpretation. of: these results is that the 
ether near the earth has the same velocity as the earth; but, 
as has been stated, it appears to be impossible to reconcile this 
view with the great mass of optical and electro-dynamic evi- 
dence. ‘The only satisfactory way out of this difficulty which 
has hitherto. been suggested is a hypothesis put forward in 
1892 by Lorentz,t and which had been mdependently sug- 
gested but not published by FitzGerald. According to this 
hypothesis, when any material body moves relatively to the 
ether its linear dimensions parallel to the direction of motion 


2 

are contracted in the ratio of N/a 7 to 1, while the-dimen- 
sions perpendicular to the direction of motion remain unchanged. 
If this contraction takes place in the interferometer of 
Michelson and Morley and im the condenser of Trouton 
and Noble, their negative results are entirely explained on the 
theory of a stationary ether.§ As Lorentz points out, this 
contraction will be very small in any motions of material 
bodies which we can observe; for example the diameter of the 
earth in the direction of. its orbital: path will be diminished by 
only 6°5°" by its motion. It would moreover be impossible to 
detect the shrinkage, however great it might be, by ordinary 

* This Journal, xxxiv, p. 333, 1887. 

+ Phil. Trans: R. 8: (A), ecii, p. 165, 1903. 

t Versl. Akad. Wet. Amsterdam, 1892-3. 

S$ See Lorentz, Versuch einer Theorie, etc., § 89. Amsterdam Proceed- 


ings, 1903-4, p. 809, reprinted in Ions, Electrons, Corpuscules, vol. i, p. 477. 
See also Larmor in FitzGerald’s Collected Papers, p. 566. 


H. A. Bumstead—Lorentz-Fitz Gerald Hypothesis. 495 


measurements, since the standards of length must shrink im the 
same ratio as the bodies to be measured. 

It would be quite misleading, however, to leave the impres- 
sion that this hypothesis depends for its credibility altogether 
upon the fact that it enables us to evade a serious difficulty 
and that it cannot be disproved by ordinary means. The 
electrical forces between charged bodies (electrons) are modi- 
fied by motion through the ether ; and they are modified in 
precisely such a way that if a given system of charges were 
in equilibrium under these forces in a certain configuration 
when at rest, it would when in motion be in equilibrium i in a 
configuration obtained from the first by the application of the 
Lorentz-FitzGerald shrinkage. Now it is a fundamental theo- 
rem in electrostatics, that a ‘charged system cannot be in equili- 
brium under the electrical forces alone; in the case of a collo- 
eation of electrons or atoms in equilibrium, the electrical forces 
must be balanced by other forces. If these inter-electronic 
forces are ethereal in origin and subject to the same. laws as 
electro-magnetic forces, then the Lorentz-FitzGerald contrac- 
tion would be expected @ priori ; and from this point of view 
the absence of the gecond order effects is evidence for the 
ethereal nature of inter-atomic and inter-molecular forces. 

Forees of this character would suffice to account for the 
changed dimensions of moving bodies even if the electrons 
themselves were left unaltered by the motion. But, as Lorentz 
has pointed out,* we must also bring in dynamical consider- 
ations which show that for complete absence of second-order 
effects the electrons themselves must suffer the same contrac- 
tion. The experiments of Lord Rayleight and of Bracet have 
shown that there is no double refraction due to the con- 
vection of transparent bodies by the earth. This implies 
that the periods of vibration of the electrons in the line of 
motion and perpendicular to it must be equal; and in order 
that this may be so, the longitudinal and the transverse masses 
of the electron must be altered by the motion in the same 
manner as the forces in these directions. An electron which 
does not change its shape (such as the rigid spherical elec- 
tron of Abraham) will not have this property ; nor will an 
electron which alters its form in any other manner than that 
described above for material bodies (such as the constant-vol- 
ume electron of Bucherer). The electron proposed by Lorentz 
obviates these difficulties. If we assume that it is, when at rest, 
a sphere of radius, a, it must when in motion with velocity »v, 
become an ellipsoid of revolution with its shorter axis in the 


direction of the motion and equal to a \/ ino oy the dimen- 


* Tons, Electrons, Corpuscules. vol. i, p. 477. 
+ Phil. Mag., vol. iv, p. 678, 1902. ¢ Phil. Mag., vol. vii, p. 317, 1904. 


496 H. A. Bumstead—Lorentz-FitzGerald Hypothesis. 


sions perpendicular to the motion remaining the same. If m, 
and m, are its longitudinal and transverse masses, and m, the 
mass for infinitesimal velocities, we shall have 


BN =) Hee emer 

2 0 a/ 1 ae B 
= With this electron 
Lorentz has shown that no optical or electrical effects of motion 
‘through the ether can be detected. 

The subject has been approached from a different stand- 
point, and treated in a very interesting and instructive manner 
by Einstein.* His fundamental postulate amounts to a denial 
that it is possible to observe any effects of uniform con- 
vection through the ether in which all the bodies concerned 
(including the observer) take part. This he calls the Principle 
of Relativity ;. the significance of the name is that only relative 
motion of one portion of matter with respect to another, or 
of one electrical charge with respect to another, can produce 
any observable effect ; uniform motion, relative to the ether 
alone, becomes as impotent, if not as meaningless, as absolute 
motion. 

Einstein considers two sets of codrdinate axes, one at rest in 
the ether (a, y, z), while the other moves with the constant 
velocity v in the a direction (&, 7, €). He defines carefully 
the meaning of “time” (¢ in the fixed system, 7 in the moving 
system) by means of clocks distributed at various points, some 
at rest with the fixed axes, and some moving with the moving 
axes. The clocks are supposed to be synchronized by light 
signals. By kinematic considerations he shows that, in order 
for the principle of relativity to hold, we must have, 


where, for brevity, 8 has been put for 


1 
a Vine (x — vt) 
Up aie 
C= @ 

il v 
Wp aig aN 


Vv e 
V 
* Ann. d. Phys., xvii, p. 891, 1905. 


where, as before, B = - 


¢ 
* 


H. A. Bumstead—Lorentz-FitzGerald Hypothesis. 497 


The distances a, y, 2 are measured by standards at rest, &, n, ¢, 
by standards in motion. The distance between two points 


(say on the z-axis) when measured by the first is 7,—#, ; when 


Ly &, 


measured by the second, it is &,-&,= The length of 


the moving standards, when parallel to the axis of « are thus 
4/ 1 — B* times the fixed standards ; when perpendicular to z, 
they have the same length as the fixed standards. In order 
therefore that Einstein’s principle should hold, it 1s necessary 
that all moving objects should suffer the Lorentz-FitzGerald 
contraction. 

It is easy to compare the rates of the fixed and moving 
clocks by considering two events whose difference in time as 
measured by the fixed clocks is ¢,—¢,; as measured by a moving 
clock whese coordinate is &', let the interval be 7,—7,. Then 


il v 
Un Sn ies Wye ge E ORiie PE V, (x, Tee ) | 
eee a SU amd ea fe Be UL, 
So that iy Ty a Teg? (Ga 2), 


Thus the moving clocks run slower than the tixed ones; if a 
clock at rest beats seconds, it must, when in motion, have a 


seconds.* 


period of 


2 


It is possible that the principle of relativity may come to 
be regarded as one of the fundamental empirical laws of 
Physics, occupying a position analogous to that of the Second 
Law of Thermodynamics. It rests on a similar basis, in that 
no deviations from it have been observed. Indeed the anal- 
ogy may be made more complete by showing that the denial 
of the principle leads to a third kind of perpetual motion, by 
which the kinetic energy of any body might be exhausted and 
the body be brought to rest with reference to the ether.t+ 
There is however an enormous difference in the breadth of 
the evidence on which the two principles rest. Violations of 
the principle of relativity lead only to minute effects which 
must be sought for in difficult and recondite experiments. 
The fact remains however that, so far as our knowledge 
extends, the principle holds; the most reasonable course in 
regard to it, and that which promises to be most fertile in 
results, is to accept it provisionally and to develop its conse- 

* This relation between the time in fixed and moving systems was also 
taken into account by Lorentz, by means of a variable which he calls local 


time. Versuch einer Theorie, § 31. 
+ Larmor in FitzGerald’s Papers, p. 566, 


498 II. A. Bumstead—Lorentze-FitzGerald Hypothesis. 


quences. This will doubtless lead to further experimental 
tests; and even apart from direct tests, one may regard the 
evidence for the principle as being strengthened if it intro- 
duces simplification and harmony into the theory of phenom- 
ena which are apparently remote from those that led originally 
to its adoption. 

As the dimensions of all bodies are altered by motion 
through the ether, it is plain that such motion must be taken 
into account in the exact theory of even purely dynamical 
phenomena. As such applications are not very familiar and 
present some points of interest, it seems not altogether super- 
fluous to consider a few very simple dynamical cases from this 
point of view. 


The Torsion Pendulum. 


Suppose a bar of length L (when at rest) hung up by a 
torsion wire in the ordinary way. Let the apparatus be ear- 


ried by the earth through the ether with the velocity v in a 
direction perpendicular to the wire; and let us consider the 
period of the pendulum when the bar is clamped to the wire 
in two different positions: (1) with its length perpendicular to ~ 
the earth’s motion, and (2) parallel to the direction of motion. 
By the principle of relativity the two periods must be equal. 
As, the length of the bar in the first position is L and in the 
second position »/1— f° L, it appears at first sight that the mass 
of every particle of the bar should be greater in position (2) 
when it is moving perpendicularly to the earth’s motion than 
in (1) when it is moving parallel to it. This would make the 


Paes LE: ee ee erate Hypothesis. 499 


transverse mass greater than the longitudinal, whereas the 
opposite is the case with the apparent mass due to electrical 
charges. A closer consideration however shows that this is an 
error arising from the application of the ideas of rigid dynam- 
ics to a body which is changing its shape. 

The path of any particle of the bar, if measured by a scale 
carried along with the earth, will appear to be the circle ABC; 
if measured with reference to a scale at rest however it will 
be the ellipse ABC in which OB = W1—8* OA. For brevity 
we shall refer to these as the ‘“‘apparent” and the “true” 
paths. In case (1), let P, be the true pornon of the par- 
ticle, P,’ its apparent position; let OM, = «,; M,P, = mets 
ener — = x AOP/ = 64-"In case (2), ‘Tet OM, = 2 
meee ye, 3 BOP;='0-; 2° BOP,’ = 0). The potential 
energy of the twisted wire in either case depends on the 
apparent angle 0,’ or @,’.. This is seen if we consider two 
pointers attached to the wire, one along OA when the wire is 
untwisted and the other along OB; if the wire is now 
given any twist the two appar ent angles 0,’ and @,’ will be the 
same, but the real angles 6, and 0, will be different as well as 
the two elliptical ares traced out ‘by the ends of the pointers. 
As the apparent motion is isochronous we may put the poten- 
tial energy equal to $k 0”. 


In position (1) we have 
po a 8) WR tan 8: 
For small oscillations, z, = a; tan 0’, = 6’, and 
y,=aV1— BO, 
k 


1 : 
Thus the potential energy is 9 @ 84) y, ; the equation of 


motion of the particle becomes 
k 
; A 
a (1 hei 8°) Y, 


MY, = 


and the period of oscillation 


/m, (1—p*) a 
on 4f 


In case (2) 


“, = asin 0’, = a6’, for small oscillations. The potential 
. 1 k 2 hd 7 
energy is thus > — z,", and the period 
: 2 ON Ta 


Smo 


500 H. A. Bumstead—Lorentze-Hitz Gerald Hypothesis. 


In order for these periods to be equal we must have 
i = ey ge 

which is the same relation as that between the longitudinal and 
transverse masses of Lorentz’s electron. That the variation 
with the velocity of m, or m, for ordinary matter is also the 
same as for Lorentz’s electron may be shown in many ways; 
the following simple example will suffice for the purpose: 

Consider an elastic rod with its length perpendicular to the 
motion of the earth and making longitudinal vibrations. If its 
period of vibration is 7’ we shall have 


mW, 


Ta 
K 
where 7, is the transverse mass of any. particle and « is the 
coetticient of stretching of the rod. We must also have, by 
Einstein’s transformation, 
abe 
Ve 
where T, is the period of the rod when at rest.* 

The constant « depends on the intermolecular forces in the 
direction of the length of the rod, that is perpendicular to the 
earth’s motion ;.and these mast vary with the velocity in the 
same manner as electrical forces. If we have two point.charges 
moving through the ether im a direction perpendicular to the 
line joining them, the force between them is 


f= 


102s 18, 4/ 1 = 
where E, is the force when they are at rest.| Thus we have 
x = K, A Go? 
and 
\/ ie = e_ 
Ke ves 1-6 tee 
whence 
1 


i. == Ti Cee gRE TEES 
2 0 a/ 1 ae 3 


It follows therefore from our hypothesis not only that all mass 
is electromagnetic but also that it varies with the speed in the 
specific manner of Lorentz’s electron. 

* If this relation did not hold for any time-keeper, the velocity of light 
measured in a moving system would be different from that measured in a 


system at rest, and thus the principle of relativity would be violated. 
+ See below, p. 903. 


H. A. Bumstead—Lorentz-PitzGerald Hypothesis. 501 


The Gravitational Pendulum. 


As a further example, consider a simple pendulum at a 
point on the earth’s surface 90° trom the pole of its motion, so 
that the string is perpendicular to the direction of motion. 
When it vibrates in a plane at right angles to the motion the 
path of the bob is a circular are and the period is 


T = on 4/ Mb 
G 


where G is the force with which the earth attracts the bob. 
When it vibrates in the plane of motion its path is the are of 


an ellipse whose axes are Land L ny SSS (EF ; for the same ver- 
tical height (that is for the same potential energy), the infini- 
tesimal are described will be in this case less than in the other 


in the ratio of 4/ 1 — 6’ to unity. So that the period is 


qe gf Teds = B’) L 


giving the same ratio of masses as before. 
Comparing, say, the first of these with the period which the 
pendulum would have if the earth were at rest, we have 


and since 


mM, = M2, 


C_—y i 2 G. 


Thus the gravitational force between two bodies moving at 
right angles to the line joining them is the same function of 
the velocity as the electric force between two moving charges 
in a corresponding position.* 

If we imagine the pendulum suspended at the place on the 
earth which is foremost or rearmost in its motion, the length 


of the string will be L »/1—* and the period 


Tean ye Feiss B 


whence 
G, = (1— 8) G, 
which again corresponds to the electricai case when the line 
joining the charges is parallel to the motion.t 
* See p. 503. +See below p. 503. 


Am. Jour. Sci.—Fourtu Series, Vout. XXVI, No. 155.—NovemBer, 1908. 
30 . 


502 HM. A. Bumstead—Lorente-Fitez Gerald Hypothesis. 


It is scarcely necessary to point out that such problems as 
we have been considering do not lead to any practicable 
experimental tests. In order to detect deviations, it would be 
necessary to measure the periods in question with an accuracy 
such that the errors should be less than 10~°, which is quite 
out of the question at present. This does not however affect — 
the legitimacy of the use of such methods in following out the 
consequences of the principle; just as the impossibility of 
actually constructing a reversible engine does not invalidate 
that method of applying the second law of thermodynamics. 
More general methods might be used; but there is some 
advantage, especially in a comparatively new subject, in the 
simplicity. and concreteness of ideas derived from the consid- 
eration of special problems. 


Applications to Gravitation. 


A promising direction in which to look for possible tests of 
the hypothesis is among the consequences of the deduction 
that gravitational forces must vary with motion through the 
ether in the same manner as electrical forces. If we have a 


NC, 2 


B,(-6) 


Vv x 


point charge ¢ moving alone the axis of «, with the uniform 
velocity v, the electric j intensity at a point P whose coordinates 
are 7, @ is 3 


Cues 
1 
7? (1 — 6" sin’ 6) - ) 


. . e e e U 
where r, is a unit vector in the direction of 7 and Ba” The 


E=V 


magnetic force is perpendicular to the plane of r and v and 
has the magnitude ~ 


mS cn ace, Case my 
Vv r’ (1— B sin’ 6)s 


* Hlectromagnetic units are used. 


(2) 


H. A. Bumstead—Lorentz-Fitz Gerald Hypothesis. 503 


These are also the values of the electric and magnetic forces 
produced at points outside, by Lorentz’s electron, or by any 
charged system in which, when at rest, the charge is dis- 
tributed with spherical symmetry and which, when in motion, 
suffers the Lorentz-FitzGerald contraction. E is the force 
exerted: by the moving charge e, upon a unit charge which is 
at rest at the point P. If the unit charge at P is in motion 
with the velocity u, then the force exerted upon it, which we 
may call (BK), is 

(E)=E+uxH (3) 


where uX fi represents the vector product. Thus the force 
on a charge at rest at the point, P, is in the direction of 7, but 
this is not true in general if it is in motion. 

Let us consider first the special case when the two charges 
have the same velocity, u=v. Let the two components of E 
parallel and perpendicular to v be E, and E,, respectively. 
The force vxH_ will be parallel to E, and in the opposite 
direction and its magnitude will be vH. So that the corre- 
sponding components of (E) are 


(EH), = E cos 6 (4) 
and 
(EZ), = E sin 0—-vH 
or since : 
v : 
H = V2 E sin 0, 
(EK), = E sin 6 (1—’) (5) 


These are the components of the actual force on the moving 
charge at P; if it is of opposite ey to the charge ¢, the force 
will have the direction given in fig. 2 
Wien 0 — 0, (1) = 0 and 
(See ele 
which is (1—") times the value of the electrostatic force when 
the charges are at rest: this corresponds to the gravitational 
case of p. 501 when the force was in the direction of motion. 


When 0 =) (E), = 0, and 


(E), =EQ-#)=VS vi-# 


which also agrees with the corresponding case for gravitation. 
If we apply this electromagnetic law of force to gravitation 

we are at first sight confronted with the dithiculty that the 

magnitude of the “force varies not only with the distance but 


504. H. A. Bumstead—Lorentz-LitzGerald Hypothesis. 


also with the angle 6; and there is also an aberration in the 
direction of the force. It is important, however, to notice 
that the variation and aberration of the force is of the second 


order in the small fraction wi instead of the first order as 
has often been assumed in discussing the possible speed of 
propagation of gravitational force.t 

In’ the special case before us, the principle of relativity 
relieves us entirely from the difficulty of even these small varia- 
tions from the Newtonian law. ‘This is apparent from the 
general statement of the principle ; but it is of some interest 
to see how the matter works out in detail. What is subject to 
observation is not the force but the acceleration ; if we let /, 
and 7f, be the components of the acceleration "parallel and 
perpendicular to the common motion of the two bodies, we 
shall have 

7 ae 
f= (hh == Crees E cos 6 


Mm, mM, 


(6) 


» BRO oe B’) 


mM, mM, 


= 


and the resultant of these is along 7, so that there is no aberra- 
tion of the acceleration. With regard to the variation of the 
acceleration with the distance, it must be remembered that, to 
an observer moving with the system, apparent distances in the 
direction of motion, (w), are greater than their true values 1 in 


1 
the ratio —=— =. Thus if the “true” codrdinatestigmame 


vi i8 
(fiz. 2) are x, y, the “‘apparent ” codrdinates will be a, y, 
2 | 
aa The “true” distance, 7, will be the 
radius vector of an ellipse whose major axis is the “apparent” 
J 
distance, 7’, and whose minor axis is 4/1 — g? 7”; the polar 
equation of the ellipse (@ being measured from the minor axis) 


where a’ = 


gives 
Paes 
6 Fema 
; : (7) 
a? ar y — Ts 


* This was pointed out by Heaviside, who was the first, so far as I know, 
to apply the modern electrodynamics to gravitation. Electrician, 1893, July 
14 and Aug. 4. Electromagnetic Theory, Vol. I, Appendix B. 

+The general reason for this has been put very clearly by Lorentz, 
Amsterdam Proceedings, II, p. 573, 1900. 


H. A. Bumstead—Lorentz-FitzGerald Hypothesis. 505 


We must also observe that the “apparent” acceleration 
(7, , F.') differs from the “true” acceleration not only on 
account of the different scale of length in the x direction, but 
also because of the larger unit of ae given by a moving 
clock. Thus 


1 os 


gee 


F (8) 
Jy = . 


In equations (6) put — for cos 8, and Z for sin @; put for E 


its value from (1) and for 7 its value from (7); substituting in 
(8) the values thus obtained for 7, and 7,, we obtain. 


é 
T peess 2 
i; = a Fe Y 


The resultant “apparent” acceleration will thus be 


= ao = yl? pe 
When r,’ is an “apparent” unit vector in the direction 7’ 
When there is relative motion of the planet with respect to 
the sun, however, the compensation is not perfect. In fact, 
deviations from the Newtonian law may be introduced which 
would not exist if the longitudinal and transverse masses were 
equal. This may be most easily seen when the attracting 
body is at rest in the ether with a planet moving about it; in 
this case the force given by electrical theory is the ordinary elec- 
trostatic force; it will be in the direction of the radius vector 
and will vary according to the inverse square of the distance. 
But the resultant acceleration will not be along the radius 
vector if the longitudinal and transverse masses are different. 
Let ¢be the angle between the radius vector and the tangent 
to the path; and let the forces and acceler ations, tangential 
and normal to the path, be respectively F,, F., 7, ty Then 


é e 
2 “8 2 : 
By = V> cos. 6: Fo = V a sin @ 


Sees a tee 
Pie eT ab 3')2 con 
Fi 201) isinig 


mm, 7 of 


506 LH. A. Bumstead—Lorentz-FiteGerald Hypothesis. 
The acceleration along the radius vector is 


J,sm 6 + f, cos d = NE (1 — By? (1— 8’ cos’) 


2 
CR 


The acceleration ee to the radius vector is 


SiG = 8)? sin pcos ¢. 


If we take the earth as a numerical example, this perpendic- 
ular acceleration is very small. Its maximum value will occur 
when the earth is at the extremities of the minor axis of its 
orbit ; at this point 


COS|@ = € ; sind = ="a/ i See 


b) 


Jn COs & — fae 


WM ie 


where € is the eccentricity of the orbit. Taking e = 1-7 x 10~ 
and 6 == L0e® we find 


2 


. We é 1 
Acceleration al Be eA? a toe £46 
: ee TS (1 B)? [1 2°93 x 10 | 


Ve a\t 71. “Q—10 
ma" (18) 2 [1:7 3< ake ] 


Acceleration perpendicular to r= 


I am not sufficiently familiar with the details of astronomical 
calculations to be able to say with entire confidence whether or 
not such an acceleration perpendicular to 7 could be detected. 
It seems, however, unlikely. The maximum effect is of the 
same order as would be produced by a perturbing body at a 
distance equal to that of the sun, and whose mass was only 


that of the earth. The perturbation, moreover, would 


200,000 

be periodic, vanishing at perihelion and aphelion and acceler- 
ating the earth’s motion in one-half the orbit, re it 
the other half. 

When the sun is also moving, the problem becomes more 
complicated. For the present purpose it will be sufficient to 
obtain the order of magnitude of the acceleration perpendicular 
to the radius vector. Let v be the velocity of the sun, and u 
that of the planet relative to the sun. Then the force on the 
planet is 


(E)=E+(v+u x 


where E is given by equation (1), in which 8 is now the ratio 
of the velocity of the sun to the velocity of light, and @ is the 
angle between the radius vector and the sun’s path. The mag- 
nitude of Hl is given by equation (2). The force E is along 
the radius vector; the force (v + u) X His normal to the 
resultant path of the planet. Let W be the angle between 7 
and the tangent to the resultant path of the planet, then 


A: Bumstead—Lorente-F; iteGerald Hypothesis. 507 


F, = E cos w 

F,=Esny+|(v+u)xH| 
in which the term enclosed by vertical lines represents the 
magnitude only of the vector. HZ is perpendicular to the plane 


containing rand Vv; let w, be the component of u in this plane 
and let w be the resultant of vw, and v. Then 


|(v +u)xH | =vH =~; E sin 0 
and F, = E (sin wy + +i sin 6). 


Dividing F, and F, by the longitudinal and transverse masses 
respectively, we obtain for the accelerations, 


3 
crs Osea oe 
Te 3 a E cos ¥ 
Ce 
eee (Bh 7 wo. 
a a K (sin wy + V2 sin 6) 


The acceleration perpendicular to the radius vector is 
1 
2) 2 ; 

J, cos W — f, ny =—*) E (@° sin w cosy + =7zsin 6 cos y). 
Recent estimates make the sun’s velocity about 20 kilometers 
per second, so that @* = 0°-45x10~; its direction makes an 
angle with the plane of the earth’s orbit of about 55°.. When 
¥ is perpendicular to the plane containing Vv and the normal to 
the plane of the orbit, cos w is nearly zero; it must in fact be 
less than e (the eccentricity of the orbit) even in the favorable 
case when the minor axis falls in this position ; with the major 
axis in this position it will be zero. In this position, therefore, 
the acceleration perpendicular to the radius vector cannot be 
as much as twice that which was found for the sun at rest. 
When r is in the plane containing v and the normal to the 
plane of the orbit, 0 = 55°, Wh < 55° and w =v. So that the © 
acceleration perpendicular to the radius vector will be less than 

iret td am ) E f° sin 110° 


a 
2 


that is its ratio to the acceleration in the direction of the 
radius will be less than 14107. 

In order to be quite certain that astronomical facts are not 
in conflict with the principle of relativity, it will doubtless be 
necessary to make detailed comparisons between observation 


508 H. A. Bumstead—Lorentze-PitzGerald Hypothesis. 


and calculation based upon this hypothesis. The small magni- 
tude of the departures trom the Newtonian law, of which more 
or less rough estimates have been given above, render it prob- 
able that there would be no serious lack of agreement. This 
probability is strengthened by a ealeculation published some 
years ago by Lorentz.* In this he found the secular variations 
of the elements of the orbit of Mercury due to the substitution 
of electro-dynamic forces for the strictly Newtonian force. The 
variations in the angular elements amounted to only a few 
seconds of arc in a century and the change in the eccentricity 
to 0:000005. He did not, it is true, take into account the effects 
of variable mass, which had not at that time become prom- 
inent even in electrical theory. The introduction of electro- 
magnetic mass will, in general, tend to diminish the effects of 
the sun’s motion and to exaggerate the effects of the motion of 
the earth relative to the sun. But from a comparison of the 
theoretical accelerations in the two cases, it does not appear 
that the variations could be increased enough to produce a 
sensible discrepancy. 


[| Note added in Proof, Oct. 12. Since the above was written, two papers 
have come to my knowledge which bear upon this question. A. Wilkens 
(Phys. Zeitschr., vii, p. 846, 1906) has introduced electromagnetic mass in 
the ordinary Newtonian equations and has calculated the resulting secular 
variations in the elements of Mercury, Venus, the Earth, Mars, and Encke’s 
comet. In all cases the variations are within the limits cf accuracy of the 
observations. F. Wacker (Ibid., p. 300) considers the case when both force 
and mass are electromagnetic and, upon applying his equations to Mercury, 
finds for the motion of its perihelion a value less than one-fifth of that 
which is at present unaccounted for. The changes in the scales of length 
and time which would be introduced by the principle of relativity could 
affect these results very little; so that it seems quite certain that our present 
observational knowledge of gravitation is not sufficientiy exact either to 
exclude the general application of the principle or to supply evidence in its 
favor. | 


* Amsterdam Proc. II, p. 571, 1900. 


Chemistry and Physics. 509 


SCIENTIFIC INTELLIGENCE. 


I. CyeEmistry AND “PuHysics. 


1. Utilization of Atmospheric Nitrogen. read 
before the Faraday Society, Dr. AtBerT FRANK has given an 
interesting account of recent progress in the preparation of nitro- 
gen compounds from the nitrogen of the air, particularly in the 
form of calcium cyanamide, to which the commercial name nitro- 
lim has been given. He discusses the production of Chili salt- 
peter and the ‘approaching exhaustion of this source of nitrogen 
supply, and gives interesting data in regard to the production of 
ammonium sulphate in the gas industry. He indicates the 
increasing demand for nitrogenous compounds for agricultural 
fertilization, and shows that the synthetic products are assuming 
great importance. He states that the production of nitrates by 
the oxidation of atmospheric nitrogen is making excellent pro- 
gress in Norway, but it is his opinion that the Norwegian salt- 
peter will remain the only direct competitor of the Chilian variety, 
on account of the cheapness with which electrical energy can be 
obtained in that country, which has unrivalled resources of water 
power. He states that calcium cyanamide has been found to be 
a satisfactory nitrogenous fertilizer, and gives an account of its 
preparation. The atmospheric nitrogen is first concentrated by 
the fractional distillation of liquid air by the Linde method. 
The remaining oxygen is then removed by passing the gas over 
heated metallic copper. The nitrogen is then absorbed by finely 
ground calcium carbide in a heated retort, according to the equa- 
tion CaC,+N,=CaCN,+C. The product contains from 57 to 63 
per cent of calcium cyanamide, giving about 20 to 22 per cent of 
nitrogen. The product is used directly as a fertilizer, and ammonia 
can be prepared from it very readily by the action of steam upon 
it. Works for the manufacture of this product have been started 
in many localities, most of which are in Europe, but one has been 
started on the Canadian side at Niagara Falls, and another in 
Japan. It is estimated that at the end of the present year works 
for the production of 45,000 tons of nitrogen by the cyanamide 
process will be in oper ation.— Chem. News, X¢Vii, 289 and 303. 

BH. b, W: 

2. The Action of Radium Emanation on Solutions of Copper 
Salts.—Last year the sensational announcement was made by 
Ramsay and Cameron that they had observed the production of 
alkali metals, particularly lithium, in solutions of copper salts 
which had been subjected to the action of the radium emanation. 
These results appeared to be of so much importance that Mpme. 
Curie and Mpiiex. Grepitscu have attempted to reproduce them. 
In the first place they placed a solution of copper salt in a little 


510 Scientific Intellagence. 


glass flask into which a large quantity of emanation was introduced 
and allowed it to decay there spontaneously. In four such experi- 
ments lithium was detected in the solutions, while blank experi- 
ments in which no emanation was used gave no indications of 
lithium. ‘The experiments were then repeated with every possible 
precaution. It was found to be extremely difficult to get chemical 
products free from lithium. It is present in distilled water, and 
almost all reagents ; and if a reagent does not contain it, and is 
allowed to remain some time in a glass vessel, it is then found to 
contain traces of the element. Water which had been distilled 
from platinum and gave no test for lithium upon evaporation, 
gave a distinct spectroscopic test for that element after it had 
stood for 24 hours in a glass flask. It was found that fused 
quartz also contains lithium, and therefore platinum was selected 
as the material in which the careful experiments were carried out. 
As a result of these experiments the investigators were unable to 
find any indication of the production of lithium by the action of 
radium emanation upon solutions of copper salts, and therefore 
they could not confirm Ramsay and Cameron’s results.— Comp- 
tes, Rendus, exlvii, 345. H. L. W. 

3. The Formation of Mists in Presence of Radium Ema- 
nation.—MpmeE. CURIE showed some time ago that the presence 
of radium emanation causes the condensation of saturant or non- 
saturant water vapor as well as other vapors. This condensation 
is manifested by the formation of a persistent mist, visible by the 
light of an electric are. Upon further study it is the author’s 
opinion that chemical compounds capable of absorbing water 
vapor until drops are formed are produced under the action of 
the emanation. The mists are persistent and may last more than 
a month, and they disappear gradually as the emanation decays. 
. With pure water and air charged with emanation, a slight mist 
lasting some days is observed. If the air is replaced by carbon 
dioxide, no persistent mist is observed. But if instead of pure 
water a mixture of equal weights of water and sulphuric acid is 
used, a dense, persistent mist is obtained. A very persistent mist 
is produced in the presence of concentrated sulphuric acid and 
carbon dioxide. It was found that a flask containing water and 
air charged with the emanation gave a much more dense mist 
when closed with a rubber stopper than when sealed up, and 
when a piece of sulphur was placed in the air in a similar sealed 
flask the amount of mist was increased, while traces of sulphuric 
acid could afterwards be detected in the water. Mists which 
were very intense at first and lasted more than a month were 
observed with petroleum ether and with carbon disulphide in the 
presence of air charged with emanation. Anhydrous ether in 
presence of carbon dioxide and the emanation also gave a persist- 
ent mist. Experiments with certain solids showed that in the 
presence of emanation, iodine and carbon dioxide as well as cam- 
phor and air gave dense mists of long duration. A mist may 
be observed with actinium in the presence of water and carbon 


Chemistry and Physics. pit 


dioxide. The emanation must be fairly concentrated at first to 
produce the mist, which, however, may persist for a month when 
the concentration of the emanation has been reduced about 200 
times.— Comptes Rendus, exlvii, 379. H. L. W. 

4. The Preparation of Argon.—FiscHeR and RineE have 
worked out a new method for producing argon from the air, 
which can be carried out on a relatively large scale at a moder- 
ate cost. The novel feature in the process consists in the use of 
calcium carbide for absorbing oxygen and nitrogen at a single 
step. This is used in the form of a powdered mixture of 90 per 
cent of calcium carbide and 10 per cent of calcium chloride 
heated in an iron vessel to 800°C. The absorption of these gases 
is complete after sufficient circulation, practically with the forma- 
tion of calcium oxide, carbon, and calcium cyanamide, accord- 
ing to the equations O,+2CaC, = 2CaO+4C, and N,+CaC,= 
CN,Ca+C. The authors prepared eleven liters of atmospheric 
argon in the course of two days by means of their apparatus, and 
showed its purity by making determinations of its density. 
They make the statements that the atmospheric air contains 0:937 
per cent by volume of “ noble gases,” the so-called crude argon ; 
that the density of crude argon is 19°94 compared with oxygen 
as 16; that crude argon itself consists of 99°75 per cent by 
volume of argon, and 0°25 per cent of a mixture of helium, neon, 
krypton, and xenon, in which neon with the density 10 predom- 
inates, so that crude argon is somewhat lighter than pure argon, 
the density of which is 19°95.— Berichte, xli, 2017. H.L. w. 

5. The Chemical Analysis of Iron; by ANDREW A. Bratr. 
Seventh edition. Pp. xix, 327, 108 figures and 5 tables. Phila- 
delphia, 1908 (Lippincott & Co.).—This excellent handbook 
appears in its seventh edition, the first edition having been issued 
in 1888 (cf. (3), xxvi, 387). The fact that its admirable. charac- 
ter has been fully recognized by those using it is well shown by 
the frequent revisions called for. The present edition contains a 
description of some new analytical processes concerning the 
separation of vanadium, molybdenum, chromium and nickel in 
steel; and further an account of the volumetric method for nickel. 
The methods for gas analysis have been revised, as also the 
subject of atomic weights ; the table of factors for the latter 
have been recalculated from the values for 1908 given by the 
International Committee. 

6. Decomposition of Water Vapor by Electric Sparks.—It 
has been suggested that the decomposition of water vapor in the 
case of thunderstorms may explain certain phenomena in those 
storms. Messrs. A. Horr and EK. Hopkinson conclude from their 
experiments “that when electric sparks pass through water vapor 
or carben dioxide the separation and arrangement of the decom- 
position products is not an electric phenomenon but results from 
gaseous diffusion. The hypothesis of electrolysis in liquids is 
therefore inapplicable.”— Phil. Mag., July, 1908, pp. 92-110. 

eos 


512 Setentifie Intelligence. 


7. Reflection from Glass at the Polarizing Angle.—Lord 
Rayueies concludes a study of this subject with the remark 
“that even a recently repolished surface, which may exhibit but 
a small ellipticity, is in a highly complicated condition. Grease 
itself may be comparatively inoperative optically on account of 
its index approximating to that of the glass. But why varying 
degrees of moisture should make so little difference is not appar- 
ent. Surface phenomena generally offer a wide field for investi- 
gation, which might lead to results throwing much needed hght 
upon the constitution of matter.”—Phil. Mag., Sept., 1908, pp. 
444-447, 8 fas: 

8. Himission of Electrons from Glowing Metallic Oxides.— 
Fevix Jenrzscu refers to the work of J. J. Thomson and to that 
of Professor O. W. Richardson on the general subject of the. 
emission of electrons from glowing bodies, and finds that the 
oxides arrange themselves in respect to rise in potential according 
to their electromotive series, that electropositive substances hold 
more free negative electrons than the electronegative. The work 
which the electron has to do in being thrown off is greater with 
electropositive substances. This work is performed only at the 
surface of the substances. The velocities of the electrons was 
found to be in agreement with Drude’s theory and with the 
observation of Lenard on the photo effect. The paper of Jentzsch 
contains a comparison between the energy of electron emission 
and the radiation energy.—Annalen der Physik, No. 11, 1908, 
pp. 129-156. Jie 

9. Lhe Winetic Energy of the Negative Electrons Emitied by 
Hot Bodies—J. J. Thomson has stated that the carriers of nega- 
tive electricity emitted by hot bodies are electrons. Prof. O. W. 
Ricuarpson has assumed that the transitional energy of the elec- 
trons inside the metal has the same value as that of the molecules 
of a gas at the same temperature as that of the metals, and that 
the translational kinetic energy of the electrons outside the metal 
possesses the same value. Professor Richardson’s paper embodies 
the result of an investigation of the portion of the kinetic energy 
which depends upon the component of the velocity normal to the 
emitting surface. What is determined is the value of $mz° where 
m is the mass of an electron and wu is its component of velocity 
perpendicular to the surface from which it is emitted.— Phil. Mag., 
Sept., 1908, pp. 353-376. Fis 


Il. GEOLOGY anp MINERALOGY. 


1. Die Entwicklung der Kontinente und ihrer Lebewelt, ein 
Beitrag zur Vergleichenden Erdgeschichte ; by THEopoR ARLDT. 
Pages 730, figures 17, and 23 maps. Leipzig, 1907 (Wilhelm 
Engelmann).—In this large and detailed work the Principal of 
the Realschule at Radeberg, Saxony, presents the history of con- 
tinental development and their biota past and present. 


Geology and Mineralogy. 513 


So great an undertaking cannot be adequately reviewed here 
and the reader will be informed only as to the manner in which 
the study is presented. The first 30 pages summarize the methods 
of paleogeography according to petrographic, paleontologice, 
plant and animal data. Following these are 371 pages giving 
the biogeography of geologic organisms, a study of the greatest 
value to all desiring to know the regional and subregional distri- 
bution of extinct floras and faunas. <A valuable feature of this 
part are the eight phylogenetic trees of the various classes of 
organisms and their geologic origin and duration. This is fol-. 
lowed by 71 pages in regard to the ancient continents and oceans 
as Northatlantis, Angara, Gondwana, the Mediterranean and 
Antarctic regions. ‘The Periodic Geological Appearances as 
glacial periods, eruptive periods, times of mountain-making, 
transgressions and cycles are discussed in 30 pages. 

The third division of the book is historical (pp. 556-611) and 
treats of the paleogeography of the earth according to geologic 
systems, and is illustrated by ten paleogeographic maps. Most 
of these are reproductions of those in Frech’s Lethza, Lapparent’s 
Traité, Neumayr’s Erdgeschichte, and Koken’s Vor welt, 

The book is a veritable storehouse of information and the three 
hundred and four sources from which it has been garnered are 
given on pp. 622-631. Allis made readily accessible in indices 
of nearly one hundred pages arranged under authors, organisms 
(from classes to species), and locality-subject registers. Cc. Ss. 

Archhelenis und Archinotis ; by HERMANN von InERING. 
Pp. 350 and a paleogeographic map. Leipzig, 1907 (Wilhelm 
Engelmann).—The Director of the Museu Paulista, Sao Paulo, 
Brazil, has studied for many years the South American floras and 
faunas and their relationship with those of other land masses. In 
this book he brings together his more important papers pub- 
lished during the past thirty years and adds three new chapters. 
His hypotheses are based in the main on the distribution of the 
fresh-water faunas, especialiy the Unionidae and Decapod crusta- 
cea, but he also considers the neotropical flora and the Tertiary 
marine faunas. Archiplata, embracing Chile and Argentina, 
has distinct biotic assemblages from those of Archibrazil or Arch- 
amazonia, 1. e., Brazil south of the Amazon. The nature of the 
barrier separating these faunas remains undetermined, as he no 
longer holds to his former view that a sea flooded between them, 
keeping the wonderful Tertiary mammal fauna of Patagonia out 
of the northern region. Archiguiana refers to the lands north of 
the Amazon and has Antillean connections. 

The southern half of Africa and Archiplata, united across the 
Atlantic, is his Archhelenis (practically Gondwana land of Suess). 
This vast land originates in Neumayr’s Cretaceous Brazil-Ethi- 
opian continent by breaking down in its northern Atlantic half 
during Cretaceous and in early Eocene time, the southern portion 
also passing beneath the sea in Oligocene time, establishing the 
present Atlantic ocean. 


514 Scientific Intelligence. 


The great Mediterranean Thetis extended diagonally across 
Brazil between Archiguiana and Archamazonia to western Chili, 
spreading here its tropical marine fauna, which was prevented 
from also attaining California by the land mass Pacila.- This 
very hypothetic land embraces the Antilles, Archiguiana, Central 
America, the Galapagos and west to the Hawaiian islands. 

Archinotis is von Ihering’s Antarctic continent of Mesozoic and 
Eocene time and embraces the Falkland Island, South Georgia 
across to South Australia connecting northward with this conti- 
nent on one end and the other with Patagonia. It was greatly 
reduced polarward and its northern connections severed during 
Neogene time. Cc. S. 

3. Camarophorella, a Mississippian Meristelloid Brachiopod ; 
by Jesse E. Hypz. Proc. Boston Soc. Nat. Hist., 34, 1908, pp. 35- 
65, pls. 6-10.—This genus is shown not to belong in the Penta- 
meride near Camarophoria but in an entirely different association, 
the Meristelline. The spiralia and the elevated muscular plat- 
forms are worked out in great detail and illustrated with excellent 
drawings. Cc. 8. 

4. The Geology of Pike County ; by R. R. Rowxey. Missouri 
Bureau of Geol. and Mines, VII, sec. ser., pp. 122, plates 6 and 
geological map.—Professor Rowley here brings together the 
results of his many years of work on the stratigraphy of Pike 
County, Missouri. The work is especially valuable for the 
detailed stratigraphy of the Paleozoic formations and the deserip- 
tions of the fossils on pages 56 to 101. Cc. S. 

5. Annual Report of the State Geologist of New Jersey, for 
the year 1907; by Henry B. Ktuuerr. Pp. ix, 192 with 50 
plates. Trenton, 1908.—This volume contains an important 
report by H. B. Kiimmel, C. C. Vermeule and L. M. Haupt, on 
the inland water-way from Cape May to Bay Head, accompanied 
by a series of folded maps; there is also a report on the improve- 
ment of Manasquan Inlet, by L. M. Haupt. Petrologists will 
be interested in the exhaustive paper on the Newark Igneous 
rocks of New Jersey, by J. Volney Lewis, pp. 97-167, accom- 
panied by some forty excellent plates. An abstract by the author 
of a part of this important investigation was published in the 
August number of this Journal, pp. 155-162. 

6. Geological Survey of Canada. R. W. Brock, Acting 
Director. General Index to Reports 1885-1906. Compiled by 
F. J. Nicotas. Pp. x, 1014.. Ottawa, 1908 (Government 
Printing Bureau).—The New Series of Reports of the Canadian 
Geological Survey commenced in 1885 and extended to 1906; 
sixteen volumes in all have been published, some of them cover- 
ing two years. The volnme now issued gives a complete Index 
to this long series and thus makes the large amount of important 
material contained readily accessible; this great labor has been 
well performed by Mr. F. J. Nicolas. The earlier index, prepared 


Geology and Mineralogy. — Bi 5 


_ by D. B. Dowling, covered the Survey’s publications from 1863 
to the end of the Old Series in 1884. 

7. Mission scientifique au Dahomey ; par H. Spare - is 
568 pp., 86 pls. and figs. and geol. map. Paris, 1908 (E. Larose). 
—This volume contains the results of two years of exploration 
in the Dahomey region of Africa, during which the. principal 
subjects of study were the geological formations and the mineral 
resources of the colony. It is in fact, however, a detailed inves- 
tigation of all the factors which determine the surface relief and 
climate of the area. The work was carried on under the auspices 
of the colonial government, aided by the French Association for 
the Advancement of Science. 

After a general description of the topography and history of 
the country, the author presents the result of a study of its 
meteorology and then considers the action of exterior geological 
agencies in modifying its relief and the effects produced, notably 
the action of the atmosphere, of the surface waters, both from the 
chemical and mechanical sides, and of the sea. These detailed 
studies of an equatorial region contain many observations of 
interest and of value and the main geographical features of the 
country are now well determined. 

The larger part of the volume is devoted to the areal geology. 
As a general result of his work the author finds that the rocks 
may be divided into three main series of undetermined age and 
these series cover each a remarkable extent of surface. The 
oldest consists of folded crystalline schists which form two great 
peneplains. The second are bedded rocks of unchanged altitude, 
which may be of early Paleozoic age, and the third are surficial 
deposits of recent formation. Unfortunately the lack of fossils 
prevents exact determination and correlation. A large area of 
deposits not far from the coast is thought to be of Eocene age. 
The folding of the first series is parallel ‘and this has profoundly 
affected the evolution of the geography; the folds have deter- 
mined the courses of the rivers, such as the windings, rapids, etc, 
of the Niger. 

These rocks are cut by, or mingled with, eruptive masses in 
places, such as granites of various types, diorites, diabases and 
gabbros. Some of the gneisses are also recognized as of eruptive 
origin. The results of detailed microscopic study of these 
various rock types are also given, the most interesting being of 
certain alkalic granites containing riebeckite. 

The last part of the work contains the results of the study of 
the distribution of certain plants and animals, that is of the 
biologic zones, and concludes with an ethnographic sketch of the 
region in which it is shown that the human grouping stands in 
close relation to certain features of geography. 

The whole work is an important contribution to our knowledge . 
of a very interesting country. Tee Meeks 


516 Screntifie Intelligence. 


8. Lhe fossil Turtles of North America; by OttvEr PERRY 
Hay. Pp. 568, with 704 illustrations in text and 113 plates. 
Carnegie Institution of Washington, Publication No. 75, Wash- 
ington, 1908.—All naturalists welcome this sumptuous volume on 
a subject that has too long remained in confusion by reason of a 
large number of imperfectly known forms and the even more 
serious lack of field work. Here, finally, the isolated facts are 
assembled and redescribed, and with many new discoveries, 
illustrated with a clearness and fulness that disarms all criticism. 
If one wished to see a few more references to European turtles, 
with the introduction of at least occasional comparative figures, 
the great size already reached by the volume would preclude 
fairness in such a wish. We do think, however, that omission 
from the legends of the source of adopted figures, and some- 
times of plates, is not commendable. Fulness of legends affords 
one of the most effective aids in text condensation. 

In completing his summary of the fossil turtles of North 
America, Dr. Hay finds 268 valid species, 76 of which are new. 
The Bridger Eocene has been particularly prolific in new forms, 
also the Laramie and Judith River Cretaceous; while the genus 
Glyptops, oldest of American forms, is found to include three 
new species and to extend into the uppermost Cretaceous. Our 
turtles culminated in size in the Fort Pierre, with also the great- 
est number of more or less distinctly salt-water forms; fresh- 
water forms were most numerous in the Bridger Eocene, and 
land forms at their largest in the late Tertiary. The presence 
of pleurodiran genera in the earlier. faune is very interesting. 

It is not. clear why our pioneer collectors so persistently neg- 
lected the Testudinata, leaving nearly to accident until very 
recently the accumulation of adequate material for establishing 
the ancient history of this group. Highly modified, the most 
widely distributed of all the reptilian orders in both latitude and 
time, yet bound to be of stratigraphic value, and barely past their 
culmination in number and size, the turtles must, according to 
any fair hypothesis, finally yield a vast fund of information con- 
cerning evolutionary limits ; they must, too, shed much light » 
problems of distribution. Their study, fortunately, is now set 4% 
far ahead as that of any other of the more extensive groups of 
fossil vertebrates yielded by this continent, if not indeed furthe: 
Dr. Hay’s volume is, then, to say the least, epoch-making ; for 1: 
comparable work on fossil turtles has appeared in Europe. Ani 
it is furthermore noteworthy from this symposium of Americ: 7 
turtles, and especially from the large number of new forms added 
by Dr. Hay and others during the past ten years, augmenting 
previously known species by fully sixty per cent, that North 
America will eventually yield an enormous fossil turtle fauna. 
Particularly in the case of the more primitive forms and the 
Protostegidze may we anticipate early results from exploration. 
The Carnegie Institution has thus opened to. other workers a 
great field in which progress is now rendered rapid and accurate. 

G. BR. W. 


Geology and Mineralogy. 517 


8. Beautiful Cinnabar Crystals from China; by A. U. 
Petereit, New York (communicated).—In August last a small 
consignment of very interesting and beautiful cinnabar crystals 
was sent to the writer from China. They were found at Wan- 
shanchang (Hamlet of Ten Thousand HIlls) Tungyen Prefec- 
ture, Province of Kweichow. Cinnabar has been obtained before 
at two different localities in China, but not to compare in 
beauty and perfection with that illustrated here. These crystals 
are ordinary and interpenetrating twins of a bright ruby-red 


€ > - ii OL GREET TE Ps 
= sa hit ia 37 


color; they are translucent, or in some cases transparent. The 
matrix is a pure white quartz, the crystals occurring in cavities 
with quartz crystals. The rare beauty of these crystals led the 
writer to urge his correspondent in China to scour the country for 
more and larger specimens. A second consignment of all that 
could be found has just arrived, and two of these remarkable speci- 
mens are Shown in the figures, reproduced from photographs, 
actual size. It is stated that the mine from which these were 
taken is now filled with water, and will not again be worked. 


Am. Jour. Sct —Fourrs Sremse Vor, XXYVI No 155 —Noververe 1908 


518 Scientific Intelligence. 


III. Botany. 


1 Grays New Manual of Botany. A Handbook of the— 
Flowering Plants and Ferns of the Central and North-eastern 
United Stutes and Canada. Rearranged and extensively revised 
by Bensamin Lincotn Rosrnson, Asa Gray Professor of System- 
atic Botany, and Merrirr Lynpon FERNALD, Assistant Professor 
of Botany, in Harvard University.. Pp. 926. New York, 1908. 
(American Book Company.)—Sixty years have elapsed since 
the first edition of Gray’s Manual of Botany was. published. 
From time to time during that long period the treatise has 
received careful editorial attention, and necessary additions have 
been incorporated. Under the limitations of stereotyped pages, 
some of these additions have been, of course, rather unwelcome, 
and have found their place sometimes in supplementary pages of 
new issues. The last thorough revision before the present one 
was undertaken after Professor Gray’s death. The work was 
very satisfactorily done by the late Dr. Sereno Watson and by 
Professor J. M. Coulter. Numerous important changes were 
made after the most careful deliberation, and the decisions proved 
acceptable to the majority of working botanists. But in the eigh- 
teen years which have passed since the publication of that sixth 
edition, great advances have been made all along the line in 
Systematic Botany, and it has been obvious that a new edition of 
the Manual is imperatively demanded. For some years this revis- 
ion has been in progress at the Herbarium, where the first edition 
was prepared. The Curator of the Gray Herbarium, Professor 
Robinson, and his aid, Professor Fernald, have given to the task 
a great part of their time and the most loving care. Serious 
difficulties confronted them. In the first place, the accumulation 
of material of late has gone on with a rapidity which threatened 
to carry the size of the volume beyond the limits of convenience, 
so that it could not longer be called properly a “ handbook.” But 
by the exercise of much skill, the revisers have kept the book 
within reasonable bounds, and have given it essentially the form 
and size of the sixth edition. ‘The second serious difficulty con- 
sisted in the absolute necessity of bringing order out of the cha- 
otic condition of nomenclature. ‘This order has been measurably 
secured by a consistent adherence to the Vienna agreement, which 
is justly acknowledged as International instead of provincial. 
But the synonyms which have found a place in other systems have 
here been placed within reach of the student. This part of the 
work has obviously demanded the exercise of the greatest care, 
and this it has received. 
A third difficulty, promptly met, was the complete change, 


-amounting almost to inversion, in the sequence of the natural 


families. This change has erown out of arecognition of affinities 
between plants, which compels a general re- arrangement. It is 
perhaps not too much to say that such a re-arrangement would 
have been unwise in 1890 when Drs. Watson and ‘Coulter issued 


Miscellaneous Intelligence. 519 


the sixth edition ; it would manifestly have been unwise to fail 
to make this change to-day. 

Many extremely perplexing questions of a minor character have 
been well and skilfully met by the authors of the present revision. 
One of these is the selection of illustrative helps. These are 
incorporated in the body of the page, and are not too numerous to 
be confusing. They are, for the most part, excellent and telling. 
Another difficulty, and the last to which we shall now refer, was 
the discrimination between forms in polymorphic genera where 
such differences can be made to appear as specific instead of 
varietal. The multiplying of these forms under the name of spe- 
cies has introduced a question of the first magnitude. Of course, 
one cannot expect to satisfy everybody even by compromises, 
but such compromises seem to be demanded now and then. The 
revisers, who may well be called the authors of the present 
edition of Gray’s Manual, have shown great ability in managing 
these perplexing matters, and are to be congratulated on their 
SUCCESS. G. L. G. 


TV. MiscerztaAngous Screntiric INTELLIGENCE. 


1. Carnegie Institution of Washington.—Recent publications 
of the Carnegie Institution are given in the following list 
(continued from p. 100): 

No. 39. Handbook of Learned Societies and Institutions. 
America. Pp. villi, 592. 

No. 75. The Fossil Turtles of North America; by OLiver 
Perry Hay. Pp. iv, 568, with 113 plates; 4to. 

No. 85. (Massachusetts). Index of Economic Material in 
Documents of the States of the United States. Massachusetts, 
1789-1904. Prepared for the Department of Economics and 
Sociology of the Carnegie Institution of Washington; by 
ADELAIDE R. Hasse. Pp. 310, 4to. 

No. 87. Volume I, Parts I, IL. The California Earthquake of 
April 18, 1906; by AnDREw C. Lawson, chairman. In collabo- 
ration with G. K. Gitpert, H. F. Rem, J. C. Branner, and 
others. Pp. xvii, 451, with 146 plates, 25 maps, 15 seismo- 
grams; 4to. Report of the State Earthquake Commission. In 
two volumes and Atlas. 

No. 89. The Old Yellow Book. Source of Browning’s The 
Ring and the Book, in complete photo-reproduction with trans- 
lation, essay, and notes; by Cuartes W. Hopety. Pp. cclxii, 
345, 4 plates. 

No. 94. The Structure and Life History of the Hay-Scented 
Fern; by Henry SHOEMAKER Conrap. Pp. 56, with 25 plates. 

No. 95. Papers of the Station for Experimental Evolutions, 
No. 10. Inheritance.in Canaries; by Cuarxies B. Davenport. 
Pp. 26, 3 plates. 

No. 99. Botanical: Features of North American Deserts; by 
Daniet Tremprty MacDovear. Pp. 111, 62 plates. 

No. 101. The Variation and Correlations of certain Taxo- 
nomic Characters of Gryllus ; by Frank EK. Lutz. Pp. 63. 


520 Screntifie Intelligence. 


2. Ricerche Lagunari ; in charge of G. P. Magrini, L. De 
Marcut, and T. Gnersorro, under the auspices of the Reale 
Istituto Veneto di Scienze, Lettere ed Arti. Wo. 8, Osserva- 
ziont Mareometriche, Lungo il litorale e in Laguna ( Biennio 
1906-1907), 50 pp. and 3 figs. Wo. 9, Impianti Mareografici 
Eseguiti, 17 pp. and 4 photos. Wo. 10, Operazioni Geodetiche 
Fondamentali per il Rilievo della Citta e Laguna di Venezia, 
64 pp., 2 photos, and 1 fig. Venice, 1908.—The reports of the 
study of the lagoons of Venice (see this Journal, xxi, 407, xxiii, 
397, xxv, 89) are continued in the three bulletins listed above. 
The work has now advanced to the point where the velocity, 
direction of propagation, and physical character of the tidal 
wave are approximately determined. ‘The records show also a 
rather uniform wave of translation and a second tide more or 
less undetermined. The stations of observation have been 
increased in number and some of them reiocated until now there 
are three in the lagoon of Malamocco, ten in the lagoon of Ven- 
ice, three in the lagoon of Chioggia, and one each in the Het 
of Murano and at Caorle. 

Of especial assistance to the committee in charge of this inves- 
tigation has been the action of the city of Venice in undertaking 
detailed geodetic work in the region about the city, including the 
establishing of a new base line. The plans include the prepara- 
tion of a large scale topographical map of the entire district. 

H. E. G. 

3. Beitrdge zur Chemischen Physiologie und Pathologie, 
herausgegeben von F. Hormetster. XI Band. Braunschweig, 
1908 (Fr. Vieweg und Sohn).—This volume concludes the inde- 
pendent existence of Hofmeister’s Deitrdge, which henceforth is 
to be merged with the Biochemische Zeitschrift, edited by Pro- 
fessor C. Neuberg of Berlin. Professor Hofmeister will enter 
the editorial board of the latter journal. The noteworthy con- 
tributions to physiology contained in the first ten volumes of the 
Beitrige have been referred to in these columns from year to 
year. The final volume forms no exception in point of merit. 
Among the forty or more papers mention may be made particu- 
larly of HE. Friedmann’s extensive studies of the katabolism of 
carboxylic acids in the animal body ; Embden’s investigations on 
the genesis of the acetone bodies ; Wiechowskvi’s observations on 
the formation of allantoin in metabolism; Baer and Blum’s 
experiments on acidosis; and, as usual, numerous contributions 
on proteins and their derivatives. L.. Bev 

4. Canada’s fertile Northland; edited by Ernest J. Caam- 
BERS. Pp. 139, with 6 tables and 5 maps in pocket. Ottawa, 
1907 (Government Printing Bureau).—How extensive are the 
natural resources yet undeveloped in the vast northern area of 
the Dominion of Canada is well brought out in this volume. 
The information is given in the form of evidence presented to a 
Committee of the Senate by a considerable number of persons. 
This is classified as follows : the territory of Ungava ; the region 
west of Hudson Bay; the navigability of Hudson Bay; the 
climate of Canada. A series of large maps accompany the 
report. 


New Circulars. 


84: Eighth Mineral List: A descriptive list of new arrivals, 
- rare and showy minerals. 


85: Minerals for Sale by Weight: Price list of minerals for 
blowpipe and laboratory work. 


86: Minerals and Rocks for Working Collections: List of 
common minerals and rocks for study specimens; prices 
from 1% cents up. 


Catalogue 26: Biological Supplies: New illustrated price list 
of material for dissection; study and display specimens; 
special dissections; models, etc. Szxth edition. 


Any or all of the above lists will be sent free.on request. We are 
constantly acquiring new material and publishing new lists. It pays to 
be on our mailing list. 


Ward’s Natural Science Establishment 
76-104 Cottecr AVE., RocuEster, N. Y. 


Warns Naturat Science EstaBlisHMent 


A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 


DEPARTMENTS: 


Geology, including Phenomenal and Physiographic. 
Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, ete. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, etc. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Wards Natural Science Establishment, 
76-104 College Ave., Rochester, New York U.S. A. 


CONE EN Ss 


: Page 

Art. XLIJ.—Some New Measurements with the Gas Ther- 
mometer ; by A. L. Day and J. K. Cusmenr ___.____- 405 
XLIII.—Range of the a-Rays ; by W. Duang .__.--=--_-- 464 


XLIV.—Alteration of Augite-IImenite Groups in the Cum- 
berland, R. I., Gabbro (Hessose) ; by C. H. Warren __ 469 


XLV.—Studies in the Cyperaceez. XXVI. Remarks on the 
structure and affinities of some of Dewey’s Carices ; b 
SES Hootie Sb ao ee as ne eae ee -. 478 


XLVI.—Applications of the Lorentz-FitzGerald Hypothesis 
to Dynamical and Gravitational Problems; by H. A. 
BUMSTEAD:.. 2 24 Sol oe oe ee eS 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Utilization of Atmospheric Nitrogen, A. FRANK: 
Action of Radium Emanation on Solutions of Copper Salts, MpMs. Curre 
and MpLur. GLEDITSCH, 509.—Formation of Mists in Presence of Radium 
Emanation, Mpme. Curie: Preparation of Argon, FiscHER and RINGE: 
Chemical Analysis of Iron, A. A. BLatr: Decomposition of Water Vapor 
by Electric Sparks, A. Hott and E. HopxKtinson, 011.—Reflection from 
Glass at the Polarizing Angle, RAYLEIGH: Hmission of Electrons from 
Glowing Metallic Oxides, F. Jenrzscu: Kinetic Energy of the Negative 
Electrons Emitted by Hot Bodies, O. W. Richa&psoy, 512, 


Geology and Mineraiogy—Die Futwicklung der Kontinente und ihrer Lebe- 
welt, ein Beitrag zur vergleichenden Erdgeschichte; by T. Arnupt, 512.— 
Archhelenis und Archinotis, H. v, TneRinc, 513.—Camarophorella, a 
Mississippian Meristelloid Brachiopod, J. E. Hype: Geology of Pike 
County, R. R. RowLey: Annual Report of the State Geologist of -New 
Jersey, for the year 1907, by H. B. KUmmert : Geological Survey of Canada, 
514.—Mission scientifique au Dahomey, H. HuBert.—Fossil Turtles of 
North America, O. P. Hay, 516.—Beautiful Cinnabar Crystals from China, 
AOH. PETEREIT, 517. 


Botany—Gray’s New Manual of Botan), 518. 


Miscellaneous Scientific Intelligence.—Carnegie Institution of Washington, 
519.—Ricerche Lagunari: Beitrige zur Chemischen Physiologie und 
Pathologie, F, HormMeIsTER : Canada’s Fertile Northland, E. J. Chambers, 
520. 


‘Librarian U. S. Nat. Museum. 


Boa DECEMBER, 1908. 
|| —__ Established by BENJAMIN SILLIMAN in 1818. J | 
THE | | 

\ 

AMERICAN \ 

: 

, 


JOURNAL OF SCIENCE. 


‘Eprrorn: EDWARD S. DANA. 


ASSOCIATE EDITORS 
Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, 
W. G. FARLOW anp WM. M. DAVIS, or CAMBRIDGE, 


L. V. PIRSSON anp H. E. GREGORY, or New Haven, 


Proressor GEORGE F. BARKER, oF PHILADELPHL, 
Proresson HENRY S. WILLIAMS, oF ItHaca, 
Proressor JOSEPH S. AMES, or BALTIMORE, 


| 

k 

Proressors ADDISON E. VERRILL, HORACE L. WELLS, | f 
Mr. J. S. DILLER, or WASHINGTON. | 


FOURTH SERIES 
VOL. XXVI-[WHOLE NUMBER, CLXXVI] 


No. 156—DECEMBER, 1908. 


NEW HAVEN, CONNECTICUT. 


eh eT 


THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. | 


en sae ee 


Published monthly. Six dollars per year, in advance. $6.40 to co 
Postal Union ; $6.25 to Canada. Remittances should be made either b 
registered letters, or bank checks (preferably on New York banks). 


| 
1908 ee | 
| 
| 


Rare Cinnabar Crystals from China. 


Of the second consignment of these beautiful Cinnabar Crystals, which 
were described and illustrated in the November Number of this Journal, 
there still remained at present writing eight specimens. Of course some of 
these may be sold before this advertisement reaches you, but if you want 
one of these specimens before they are all gone, it is necessary to send in 
your order immediately. These eight specimens are among the choicest of 
this remarkable consignment. Their prices range from $10.00 up to $125.00. 
Write for illustrated pamphlet. 


BEAUTIFUL ZEOLITES, FROM THE NEW ERIE R. R. CUT AT 
BERGEN HILL, NEW JERSEY. 


We have added to and enriched our stock of these unsurpassed zeolites. 
Write us and we will send you a box on approval, or better, call and see 
them. 


NEWLY DISCOVERED RARE AND SHOWY MINERALS .AND 
NEW FINDS. 


‘We have received this month quite a number of new consignments con- 
taining new discoveries both as to minerals and localities. Also some of 
wonderful beauty and extreme rarity. Space will not permit an extended 
description here, but we will mail list on request. 


SUITABLE FOR CHRISTMAS GIFTS. 


We have secured for the Christmas trade a number of large and small lots 
of Cut Gems, Cameos, Antique Mosaics, Opal Carvings. On account of the 
hard times both in Europe and in this country, we secured these at un- 
precedented low prices and will sell them likewise. Don’t miss this chance, 
as it may never come again. We name a few below :— 

Garnets, green and red; Aquamarines; Zircons. all shades: Sapphires, 
all shades ; Star Sapphires and Star Rubies ; Chrysoberyl, Cats-eye ; Spirels, 
all shades ; Topaz, pink, blue, brownish and golden color; Pink Beryl; 
Sphene ; Tourmaline, all shades; Amethyst, Siberia, royal purple color; 
Andalusite; Star Quartz; Peridote; Opal matrix, Mexico and Australia ; 
Precious Opal, Australia, Mexico and Hungary ; Hyacinth ; Turquoise, Mex- 
ico and Persia: Kunzite; Reconstructed Rubies and Sapphires ; Emeralds ; 
Opal Carvings, such as pansies, vine leaves with bunches of grapes, and 
other small Opal novelties ; Antique and Modern Cameos; Antique Mosaic 
and other semi-precious stones. 


POLISHED MINERALS. 


Lapis-lazuli, Chili, Persia and Russia; Malachite, Russia; Californite, 
Tulare Co. and Pala, Cal.; Petrified Wood, Arizona; Williamsite, Pa.; Ser- 
pentine, Pa.; Bloodstone, HE. India; Moss Agate, E. India and Lake Supe- 
rior ; Quartz with Rutile, Madagascar and N. Carolina; Smoky Quartz, White 
Quartz and Amethyst, from Japan, cut in form of a crystal; Chrysoprase, 
Cal. and Germany; Jade, China; Tiger-eye, Africa; Onyx, Mexico; Rose 
Garnet; slabs, Mexico; Jasper, all known localities ; Silver with smaltite, 
Cobalt, Ont.; Opal, Queensland and N.S. Wales; Agates, from all known 
localities, very picturesque ; Tourmaline, beautiful sections, from all known 
localities. 

Let us know your wants, and we will send them on approval to you. 


AsoH. PETEREIE, 
81—83 Fulton Street, New York City. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[FOURTH SERIES.] 


Arr. XLVII.— The Preparation of Urano-uranic Oxide, U,O,, 
and a Standard of Radio-activity ; by H. N. McCoy and 
G. C. AsHMAN. 


Iris obvious that for the comparison of the activities of 
radio-active substances a standard or unit of activity is of 
prime importance. One of us* has proposed to take as this unit 
the activity due to one square centimeter of a thick film of 
U,O,, of sufficient thickness to have maximum a-ray activity. 
It was shown that such a standard could be reproduced easily 
and apparently with quite definite activity. We have now 
studied the problem of the preparation of a standard of activity 
more fully, with the results recorded below. 

The chief points of importance are : 

First, The complete removal from uranium of radium and 
other active as well as inactive impurities ; 

Second, The preparation of an oxide of perfectly definite 
composition ; | 

Third, The preparation of uniform films of the oxide. 

Fourth, The activity due to the 8 rays. 

Material from three distinct sources was used : 

(A) So-called chemically pure uranyl nitrate from the firm 
of C. A. F. Kahlbaum. This was practically free from all 
ordinary impurities. The radium content, which was deter- 
mined by means of the emanation, amounted to 2°5 x:0-° of 
the equilibrium quantity. A portion of this nitrate, recrystal- 
lized from water twice, constituted sample A. It was not 
tested for radium again, as the original amount would increase 
the activity less than 0°01 per cent. 

(B) An old sample of uranyl acetate, which contained a con- 
siderable amount of sodium as the chief impurity. The amount 


* McCoy, Phil. Mag., xi, 177, 1906. 
Am. JouR Sci1.—FourtH SERIES, Vout. XXVI, No. 156.—DercremsBer, 1908, 
37 . 


4 
| 
| 
| 


522 McCoy and Ashman— Urano- Uranic Oxide. 


of radium present was very small: 2x 10—* of the equilibrium 
quantity. After conversion into nitrate and two erystalliza- 
tions of the latter from water, no trace of impurity could be 
found by chemical tests; the material formed sample B. 

(C) The third sample was prepared from the uranium 
extracted from 29 g. of pitchblende from the Wood Mine, 
Colorado and purified as previously described, (Joc. cet.) The 
process in brief consisted in treating the nitric acid solution of 
the mineral, after removal of silica, with an excess of ammonium 
carbonate solution to remove iron, etc., and the filtrate with 
ammonium sulphide to remove copper, lead, etc. The erude 
uranyl carbonate, obtained by boiling the last filtrate, contained 
two percent of the equilibrium quantity of radium. ‘This was 
removed by three precipitations of barium sulphate in the solu- 


tion, the first precipitate taking out 95 per cent of the radium , 


then present. The U,O, made from this material three years 
ago seemed to be very pure and had, as then stated, an activity 
within 0°15 per cent of that of another sample of U,O,, which 
was supposed to be, and probably was, of great purity. A 
large portion of this material had been kept in solution as 
ammonium uranyl carbonate from May, 1905 to November, 
1907. During this time a very small precipitate had formed. 
The filtrate from this precipitate was boiled; the uranyl car- 
bonate so formed was called sample OC. 3 

By decomposing uranyl nitrate at a temperature below red- 
ness, the orange oxide, UO,, is obtained; this loses oxygen at 
a higher temperature, giving U,O,. This latter oxide is not 
perfectly stabie, but loses oxygen slowly when very strongly 
heated, as first observed by Zimmerman.* 

From considerations based upon the phase-rule, for the three- 
phase system, U,O,, UO, and O,, the partial pressure of the 
oxygen is a function of the temperature; consequently for a 
fixed pressure of oxygen (say that in the atmosphere) there 
must be a definite temperature at which the three phases can 
exist in equilibrium; above this temperature U,O, will pass 
into UO,; below it, the dissociation will not take place. Since 
the temperature of a solid contained in a crucible heated in the 
flame of a blast-lamp is far from uniform throughout the mass, 
we have used an electric muffle which gave perfectly definite 
temperatures, which were accurately measured by means of a 
platinum-rhodium pyrometer. 

In one experiment 7 g. of sample A, purified uranyl nitrate, 
was converted at a moderate. temperature into the orange- 
colored trioxide. This was placed in a platinum crucible and 
heated in the electric muffle. The crucible was loosely covered, 
allowing free access of air. After constant weight had been 


* Ann, cexxxii, 276, 1885. 


MeOoy and Ashman— Urano- Uranie Oxide. 523 


TABLE I. 
Duration of Heating. Temperature. Weight of Oxide. 
60 min. 560° C, 3°698 
35 600 3°697 
75 600 to 700 3°693 


Reduced to UO, in hydrogen, over Bunsen flame (37554) 
The dioxide was reheated, in air, in the muffle. 


30 700° 3°691 
And reduced to UO,, as before (3°552) 
and again heated in the air, in the muffle: 

30 570° 3°690 


This experiment was repeated several times with perfectly similar 
results. 


reached, the U,O, was reduced to UO, by the usual analytical 
method, heating over a Bunsen flame in a stream of hydrogen. 
The reduced oxide was again heated in air in the muffle. It 
absorbed oxygen rapidly and changed to U,O,. Table I gives 
the details of the experiment. ; 

The reduction of an oxide of uranium to UO, and weighing 
in that form is a standard analytical method. Therefore the 
composition of the product obtained by the reduction may be 
considered as known. The mean weight of the UO,, 3°553 g., 
corresponds to 3°693 g. of U,O, The fact that the product 
formed in air at 700° has the same composition whether formed 
by the decomposition of the trioxide or by the oxidation of 
the dioxide shows that this temperature is below that at which 
the U,O, can lose oxygen in contact with the air. There is, 
therefore, no danger that heating for any length of time will 
decompose U,O, at 700°. | 

Nine portions of U,O, were prepared from samples A, B and 
C,and made into ten standard films. Films nine and ten were 
made from the oxide prepared from sample A as shown in 
Table I. The U,O, for film thirteen was made as follows: A 
portion of sample C was heated in the muffle, in air, for thirty 
minutes at 700°; weight 1:°2134 9. This was then reduced by 
hydrogen and again heated’ in the muffle, in air, for thirty 
minutes, at 700°; weight 1:2133 @ Each of the remaining 
-seyen portions of U,O, was prepared separately by heating the 
corresponding sample for forty to sixty minutes, in air, in 
the electric muffle, at 700°. 

The method of preparation of films for activity measurements 
has previously been described in detail.* Seven films, Nos. 9 
to 19 inclusive, were made in cireular tin dishes 7°15™ in 
diameter, with rims 0°8™ high; films 23, 24 and 25 were made 
on flat copper plates, 7-00 in diameter. 

* McCoy, J. Amer. Chem. Soc., xxvii, 391, 1905 ; Phil. Mag., xi, 176, 1906 ; 
McCoy and Ross, J. Amer. Chem. Soc., xxix, 1698, 1907. 


5o4 McCoy and Ashman— Urano-Uranic Oxide. 

The activity measurements were made in a gold-leaf electro- 
scope having an ionization chamber 19°5°™ square and a dis- 
tance of 85° between the film and the electrode of the 
gold-leaf system. The scale of the micromoter microscope cor- 
responded to potentials between 576 and 473 volts, the fall of 
potential across the scale being 103 volts. Our standard films, 
which had about 0°020 g. of oxide per sq. cm., were all sufti- 
ciently thick to have the maximum a-ray activity. The 6-ray 
activity was small, but varied with the weight of the film. It 
was also evident from the nature of the B-rays that the observed 
activity of the latter must depend upon the size of the ionization 
chamber, which in the case of our electroscope, though large 
enough to get the maximum effect of the a-rays, was insufficient 
for the B-rays. We have determined the -ray activity for 
our electroscope in the following manner: The standard films 
of U,O, were covered with one to four pieces of aluminum 
foil 0:0048™ thick and the resulting @-ray activity measured. 
The first layer of foil cut off all the a-rays and a portion of the 
B-rays. By graphical extrapolation of the curve having 6-ray 
activity and number of foils as coordinates, it was found that 
this portion amounts to 9°2 per cent of the effective S-ray 
activity of the uncovered film. 

The further data for the films made from samples A, B, and 
C are given in Table II, the activity being expressed in terms 
of an arbitrary unit. 


TaBLeE II. 
Films in tin dishes 7:15°™ in diameter with rims 0°8™ high. 
a and 3 
Sample No. Weight Activity (6 Activity* a Activity 
a Gps ee 9 0°816 10080 0°0108 0°9972 
DNS on ete 10 0°807 1°0075 0°0100 09975 
| Byes oe atee el Ve) 0°820 0:9990 0:0020 0:9970 
} OVAh Gwe poe menue IS) 0°753 170005 0°0020 0°9985 
ict caren 13 0°920 1:0040 0°0110 0°9930 
Cire 14 0°892 1:0010 0:0110 0°9900 
Cpopera te Lb 0°793 1:0070 00154 0°9916 
Films on flat copper plates 7:00 in diameter. 
A eae 23 0°694 (SS 0°0296 10815 
ACs gies 25 0°625 1°1080 0°0262 10818 
Bi See 24 0°629 1:0950 0°01338 1°0817 


These results show that the method of making U,O, gives a 
product of definite activity. The somewhat low activity of 

*The activities were measured before the maximum amounts of UX, 
which had been largely removed in the process of purification, had again 
accumulated ; for this reason the (-ray activity of a film is not a definite 
function of its weight. 


McCoy and Ashman— Urano-Uranice Oxide. 525 


sample C may be due to a trace of impurity; but the value is 
sufficiently close to the mean for A and B to show that the 
method is satisfactory. . 

We next made a new set of films on flat copper plates which 
were cut on a lathe and were almost perfectly circular. These 
plates differed slightly in size, however, for which reason 
the diameter of each plate was measured (in two or more 
directions) with a comparator, capable of giving results accu- 
rate to 0-°001™. The U,O, for these films was prepared in a 
single portion from sample A. On account of the large 
quantity of material used it was necessary to continue the 
heating at 700° for about three hours in order to obtain con- 
stant weight. ‘The activities are shown in Table III; the last 
column gives the corrected activity for exactly 7° diameter. 


TABLE III. 
a+ Corrected 
No. Weight Activity 6 Activity a Activity Diameter a Activity 
a>. O-6812 1°:0800 00263 1°0537- 7:0168 1:0487 


28a... -0°8776 1°0788 0°0347 10441 6°9912 1°0467 
Zoe" 074996 10861 0°0300 1°0561 70174 1°0509 
290= -. 07770 1°0812 . 0°0288 170524 70174 1°0472 
aeae O° 7801 1°0935 0°0326 1°0609 70301 1°0519 
ae -O'070 10737  0°0270 1°0467 6°9969 1°0476 
eae O-Tor7 1'0796 0°0321 1:0475 6°9948 1°0491 
34a... 0°9107 10891 0°0364 1°0527 6°9948 1°0543 


Mean, 1-0495 


The activities in Table III are also expressed in terms of an 
arbitrary unit, about three per cent greater than the unit used 
for Table II. One of us (Joc. cit.) has proposed to take as the 
unit of radio-activity, the activity due to one sq. cm. of such 
films of U,O, as those to which Table III refers. In terms of 
such a unit, the activity of each film of Table III is represented 
by its area. | 

Several years ago, Rutherford and McClung* determined 
the ionization current of layers of U,O, of different thickness, 
when placed between parallel plates sufficiently far apart for 
the complete absorption of all the a-rays in the air between 
the plates. The saturation current per sq. cm. of surface was 
4:0 X10~-“ampere, for a weight of 0-0189 g. of U,O, persq. em. 
This weight is great enough to give the maximum a-ray activ-- 
ity provided the material is in the form of a perfectly uniform 
film ; but this was not the case in Rutherford and McClung’s 
experiment, as the oxide was merely “dusted” on the plate 
and therefore the observed current was far below that fora 


* Phil. Trans. A., exevi, 52, 1901. 


526 McCoy and Ashman— Urano- Uranie Owidle. 


perfectly uniform film.* We have made a determination of 
the saturation current in absolute units for the a radiation of 
our standard of activity. To do this we made use of a stand- 


iielea be 


ard condenser of the concentric spheres type, in conjunction 
with a gold-leaf electroscope. See fig. 1. 

The electroscope case consists of two rectangular compart- 
ments, made of sheet brass 1°5™ thick. The ionization 
chamber, A, is 19°5°™" square and 14™ high; the gold-leaf 
chamber B is 8 by 10™ and 12°7™ high. The gold-leaf system 
is insulated by an amber plug, D, and carries as its lower end 
the circular electrode, E, a brass plate 14°™ in diameter. F is 


* McCoy, J. Amer. Chem. Soc., xxvii, 395, 1905. 


McCoy and Ashman— Urano-Uranic Oxide. 527 


the charging device, which is connected with a three-point 
key, that keeps F earthed, except at the moment of charging. 
G represents a pair of glass windows, through which the 
motion of the leaf is observed by means of a micrometer 
microscope. The door, which slides upward, is at H. Lisa 
metallic support of variable height, for the film. L is a flat 
metal plate 18°" square with a 2° hole in the center; it is 
supported by a pair of brass rods at two diagonal corners and 
may be raised or lowered. When this plate, L, is placed 
about 8™™ above the electrode, E, the electrostatic capacity of 
the electroscope (without the condenser, C), is about five times 
as great as it is without L.* 

The standard capacity, C, consists of two concentric spheres — 
of sheet zinc.t The outer one is soldered to a brass block, J. 
having a 5” hole, through which passes a 1™™ brass wire 
soldered to the gold-leaf support; a very fine wire of spring 
brass makes contact with the inner sphere. The latter is sup- 
ported by three amber pins, KK; each pin is threaded into a 
small brass ring, so as to be adjustable; the brass ring is carried 
by another ring of vuleanite, which insulates it from the 
sphere and enables the brass ring to be used as a guard ring. 
It was found, however, that the insulation was sufficiently good 
without the use of the guard rings. The upper half of the 
outer sphere is detachable; this arrangement allows the inner 
sphere to be introduced or removed readily. The whole 
apparatus is surrounded by a wooden case, surmounted by 
a glass bell-jar. This serves to keep the temperature uniform 
inside the gold-leaf chamber and so avoids air currents which 
greatly diminish the accuracy of the activity measurements. 

The condenser spheres were made of spun sheet zinc. The 
radii were calculated from the weight of water required to fill 
each and the weight of the zinc of the smaller sphere. The 
exterior radius of the smaller sphere was 6°298™; the interior 
radius of the larger 7:590™. The capacity of the condenser 

* We have found that the observed activity of a given film is much more 
nearly constant when the capacity of the electroscope is increased by means 
of the plate, L; the reason for this is doubtless two-fold. First, the much 
slower movement of the leaf permits greater accuracy in timing; and sec- 
ond, the natural variation in activity during a fixed interval is a smaller 
fraction of the whole activity, the longer the interval. By increasing the 
time of discharge five-fold, the fractional error due to natural variation of 
activity would be reduced to less than half that for the more rapid discharge. 
See Geiger, Phil. Mag., xv, 539, 1908, and Meyer and Regener, Ann. Phys., 
xxiv, 757, 1908. 

+The mode of combination of electroscope and condenser is a modifica- 


tion of that suggested by Prof. Millikan; Electricity, Sound and Light, 
p. 301, Ginn & Co. 1907. 


(o'6) 


2 


Or 


MeCoy and Ashman— Urano-Uranic Oxide. 


‘ See K.8.U. It is considered 
that when the inner sphere of the condenser is placed in posi- 
tion the calculated capacity, 38°83 E.S.U., is added to that of 
the system when this sphere is absent, but all else arranged as 
shown in the figure. Calling the capacity of the electroscope 
alone ¢, and with the condenser c,, then the ionization current 
mee — 2 
Mite 

SARE to the two ends of the seale and z, and @, are the times 
of discharge for the same film for the changes of potent Dp, 
and p, respectively. Therefore 

(C, = GN t, P, 

l, P,—4P, 

The quantity ¢c,—c, is the capacity of the condenser=36°83 
E.S.U. 

We used film No. 30, Table 3, placed at a distance of 3°6™ 
below the electrode of the gold-leaf system. Experiment 
showed that this distance was entirely sufficient for the pro- 
duction of the maximum ionization current; at a distance of 
4:5°™ or more the current was slightly smaller, owing, of course, 
to partial recombination of the ions. 

As the closely agreeing means of several determinations, the 
times of discharge of the electroscope with and without the 
condenser were 243-9 and 420°9 sec. respectively, for the 
uncovered film. The times when the a-rays and 9-2 per cent 
of the @-rays were cut off by a sheet of aluminium 0:0043™ 
thick were 10,860 and 12,435 sec. respectively.* From these 
data it follows that the times of discharge for the a-rays alone 
were 249-9 and 436-4 sec. respectively. The fall of potential 
across the scale was 103°05 volts without the capacity and 
102°63 volts with the capacity, the measurements being made 
with an electrostatic voltmeter. From these data it is found 
that c, = 48°84 E.8.U. and ¢, = 36°83+48°84 = 85-67 E.8.U. 


was, therefore 


where p, and , are the potential differences cor- 


= 


1 


Therefore the a-ray ionization current 7 = ap = 2250. 
1 

10-* amp. Film No. 30 is 7-0168°™ in diameter; its area= 
38°67 sq. cm. Therefore the current per sq. cem.=5°79 KX 10>" 
amp. ‘The total activity of 1 g. of uranium? is equal to that 
of 796 sq. em. of a thick film of U,O,. Therefore the total 
a-ray ionization current of 1 g. of uranium=4°61 & 107" amp. 

* These times represent the 90°8 per cent of the @-ray leak plus the natural 
air leak and the leak across the insulation. The latter is somewhat greater 
when the condenser is attached to the electroscope; this makes the time 


12,435 sec. shorter than would otherwise be expected. 
+ McCoy and Ross, loc. cit. 


MeCoy and Ashman— Urano-Uranic Oxide. 529 


It is well known that the potential gradient required to pro- 
duce a saturation current increases with increasing activity, 
the recombination of the ions being greater for a given poten- 
tial gradient the more intense the ionization. It was, there- 
fore, possible that the observed current for a standard film was 
below the maximum on this account. We made the following 
experiment to throw light on this point. Films of U,O, were 
made in the usual way on a pair of semi-circular plates, made 
by cutting an ordinary 7™ plate into halves. The activity of 
each half-film was measured separately and compared with 
that observed when the two were placed side by side to make 
a circular film. The sum of the separate activities was 0°33 per 
cent greater than that of the two together. The experimental 
error of the activity measurements did not exceed 0-05 per cent. 
The experiment shows that appreciably greater recombination 
of the ions takes place when the two plates act simultaneously, 
due to the more intense ionization. It follows from this, that 
the ionization current calculated above for one sq. cm. of 1G 
is somewhat smaller than that which actually would be observed 
for a film of unit area. However, the error which thus arises 
is eliminated in the calculation of the 1onization current of unit 
mass of uranium or thorium; since in such-a case the specific 
activity is calculated from the value based on the activity of an 
infinitely thin film* which would produce a vanishingly small 
ionic concentration. Consequently the ions would suffer no 
recombination and therefore the calculated ionization current 
is that which would be produced by all of the ions formed. 

Boltwoodt+ has determined the relative activity of radium 
and uranium by direct comparison of the activity of a minute 
known quantity of radium with the activity of very thin films 
of known weight of U,O,. It was found that radium (free 
from its products) is 1 30 x 10° times as active as an equal 
weight of uranium. Itutherford{ found that the ionization 
current of a thin film of 0-484 mg. of pure Rabr,, free from 
its active products, was 8-4 x 107° amp. as measured by a sen- 
sitive See ees: Considering half of the a-rays to have 
been absorbed by the plate carrying the film, this is equivalent 
to a current of 5-94 x 10“ amp. for 1 g. of pure radinm. We 
‘have found the total ionization current of 1 g. of uranium to 
be 4°61 x 10-" amp. Therefore the a-ray activity of radium 
(free from its products) is 1°29 x 10° times that of an equal 
weight of uranium, a result which isin good agreement with 
that found by Boltwood. 

* McCoy, Jour. Amer, Chem. Soc., xxvii, 402, 1905. 


+ This Journal, xxv, p. 296, 1908. 
t Phil. Mag., x, p. 207, 1905. 


530 McCoy and Ashman-— Urano-Uranice Oxide. 


Summary. 


1. Uranium is easily freed from all other radio-active sub- 
stances. 

2. Pure U,O, of perfectly definite composition is readily 
obtained by heating any lower or higher oxide of uranium in 
air at 700° | 

3. Uniform films of U,O,, 7°" in diameter, weighing 0°6 to. 
0°8 g., have definite and constant a-ray activity and are there- 
fore recommended as standards of radio-actiwity. 

4. The a-ray saturation current for such a standard film 
was measured in absolute units and from the results the total 
ionization current for 1 g. of uranium, in an infinitely thin film, 
was calculated. 


Kent Chemical Laboratory, University of Chicago, Sept., 1908. — 


Wright—Telemeter with Micrometer Screw Adjustment. 531 


Art. XLVIII.—A Telemeter with Micrometer Screw Adjust- 
ment ; by Frep. Eucenn Wricut. 


Durtne the past few years many different devices have been 
suggested for measuring the distance to a distant object by 
merely sighting at it, and some of these, particularly the stereo- 
comparator of Pulfrich, have proved serviceable. Three or 
four years ago, in connection with geological field work 
involving considerable topographic sketching, the need of such 
an instrument was keenly felt by the writer and the following 
apparatus devised. ‘The apparatus is simple in construction 
and sufliciently accurate for the purposes for which it is 
intended. It appears, moreover, to be constructed on a prin- 
ciple not heretofore applied to telemeters, and may, therefore, 
be described very briefly. 


Fic. 1. 


The principle of its construction®* is illustrated in fig. 1. 
Light waves from a distant object strike the two telescopic 
lenses L, and L, (both 50™ focus) and after transmission are 
reflected from the two right-angled prisms P, and -P, to the 
reflecting prism pair P,, and thence to the ocular O. The 
incident rays are not precisely parallel and do uot converge to 
the same point in the focal plane of the ocular. They can be 
made to do so, however, by moving the prism P, back parallel 
with itself by means of the micrometer screw M until the two 
points coincide and merge apparently into one (indicated by 
the cross in front of the ocular). The angle between the inci- 
dent light rays from objects at different distances is different, 
but by moving the micrometer screw the two images resulting 
therefrom can be brought to coincidence. | 

Conversely, having once calibrated the micrometer screw 
readings for a number of distances, it is not difficult to mter- 

* The two test telemeters which have thus far been constructed on this 


principle were made in the workshop of the Geophysical Laboratory and 
can be duplicated by any good maker of instruments. 


532 Wright—Telemeter with Micrometer Screw Adjustment. 


polate and to draw a curve indicating the distance away of 
any object in terms of micrometer screw readings. ‘The 
equation expressing the relation between micrometer screw 
readings and distances away of Obs is derived below 
(page 534), 

The optical parts of the instrument are the following: 
Two achromatic plano-convex telescopic lenses, 50™ focal 
length and 25™" diameter; two right angle reflecting prisms 
P, and P,, 18™™ length of side; a reflecting prism pair P, con- 
sisting of two right-angled reflecting prisms, the larger one 
of 20" edge and the smaller one of 14"™ edge, its hypothenuse 


Fie. 2a. el ere c: 


face fitting the side of the larger prism closely. The hypothe- 
nuse surface of this smaller prism is silvered ; at its center, a 
round circular portion 3 to 5"™ in diameter has been removed 
as in the Abbé camera lucida reflecting prisms. The two 
prisms are cemented with Canada balsam, the light from the 
larger prism reaching the ocular through the central part of 
the field, while that from the smaller prism is reflected by the 
peripheral silvered margin. 

Experiments with this type of double reflecting prism have 
indicated that the instrument should be so built that for aver- 
age distances the round aperture in the center of the field 
should be situated near the focal plane of the ocular O. 

Other reflecting devices were tried in place of the prism 
pair P., two of which are shown in figs. 2a and 2b, in which 
plane parallel glass plates are used. The four elas plates of 
fig. 2a are very difficult to adjust accurately and for the pur- 
pose special adjustment facilities had to be constructed. The 
device of fig. 2b consists of two glass plates and the light rays 
follow the paths indicated by the arrowed lines, With the glass 
plate devices the images are superimposed, while with the 


Wright—Telemeter with Micrometer Screw Adjustment. 533 


prism pair P, the image in the central part of the field forms 
the continuation of that in the margin. By placing the 
reflecting prism, however, so that it is at some distance from 
the focal plane of the ocular, the two reflected images can 
likewise be superimposed. This was done on a trial test by 
replacing in fig. 3 the prism P, by a total prism pair, thus 
’ bringing the light from both L, and L, to a common path and 
to reflection in a single reflecting prism at P, in place of the 
prism pair there indicated. The unfavorable features of the 
glass plate reflecting devices are chiefly the great loss of light 
and consequent dim field, and the double image from each lens 
which results from reflection from the two sides of each glass 
plate. For these reasons the permanent use of glass plates in 
this connection hardly seems feasible. Several other reflecting 
prism devices were tried, but that of fig. 1 and its modification 
in fig. 3 have thus far proved most satisfactory. 

The arrangement of the different parts is indicated in fig. 1; 
L,, L,, P, and P, are rigidly fixed and stationary, while the 
ocular O and the prism P, are movable,—the ocular for focus- 
ing purposes and the prism P,, by means of the fine micro- 
meter screw M,, for the purpose of measurement. It is 
imperative that the construction of the instrument be rigid 
throughout. In the trial instruments thus far used, the 
material has been either thick hard wood or a brass cylinder, 
and of these the brass cylinder is undoubtedly the more practi- 
eal. The three reflecting prisms P,, P, and P, are supported 
on their hypothenuse sides by brass blocks faced with cork, 
and these in turn are adjustable on a brass plate. By this 
method, the centering and adjusting of the optical parts can be 
accomplished at any moment accurately and with little trouble. 
The base line of the instrument to which all measurements are 
referred is the distance L, L, and its length should remain 
unchanged at all temperatures. Unless the instrument is 
made of some non-expansible material, as invar steel, however, 
this condition cannot be fulfilled, but for practical purposes 
the minute changes in length which the slight temperature 
variations produce may be neglected, since the instrument 
itself is not one of exceeding accuracy. 

Assuming’ the distance L, L, of fig. 1 to remain constant, 
the theoretical accuracy of the instrument for different dis- 
tances is not difficult to ascertain. -In fig. 1, let L, L,=a, 


then in the triangle CDA the side CD = aa Since the dis- 


tance of the object is always great with respect to the base of 
the instrument L, L, the angle, L,-object-L,, is small and the 
triangle DCA may be considered without sensible error sim- 


ilar to triangle L,-Obj.-L,. Accordingly 


534 Wright—Telemeter with Micrometer Screw Adjustment. 


= Da (1) 


Let distance of object L,-Obj.=y and movement of micro- 
meter screw AD=a, then | 
y a 
EES Seed UW Gags 56) Y 
a 2.2 
Q’ 
22x 


Y= 


To find the relative accuracy of the instrument for different 


Fre. 3. 


distances y for a given small increment of a, equation (3) may 
be differentiated. 


ot tel (3) 


Since absolute values only are considered and not the fact that 

~ and y are counted in opposite directions, the negative sign of 

equation (8) may be disregarded. On substituting the value 

of « from (2) in this equation, we obtain | 
9 2 

dy = 7. da | (4) 


Gi 


which states that the sensitiveness of the instrument decreases 
with the square of the distance and increases with the square 
of its length. . 

In the trial telemeter of fig. 1, the distance L, L,=a 1s 
935° or about 1 meter. The micrometer screw reads to 


Wright—Telemeter with Micrometer Screw Adjustment. 535 


‘005"" and actual tests with the instruments show that changes 
produced in the field by a movement of -01™™ of the micro- 
meter screw can be readily detected. dx is therefore :01™™ 
or ‘00001 M, and equation (4) reads 
dy=2'y* °00001 
or dy=:00002 . y’ 

At a distance of 50 meters, therefore, the probable error of 
the instrument is ‘05 M, or -1 of one per cent; at 100 M, -2 
M of -2 of one per cent; at 1000 M, 20 M, or 2 per cent. 

In fig. 3, a slightly ‘different disposition of the reflecting 
prism is shown which for a given base line is twice as accu- 
rate as that of fig. 1, the entire base line a being used to pro- 


duce deflections of « instead of 7 asin fig. 1. For this modi- 


fication the equation reads, therefore, 


and dy, = z ae 
a 


The form of the prism pair P, in fig. 3 is slightly different 
from that in fig. 1, but can be ger ound with equal ease. 

' From the diagrams it is apparent that the images from L, 
and L, do not form in precisely the same planes and are theo- 
retically, therefore, never in perfect focus at one and the same 
time, except for objects at an infinite distance. Experience 
has shown, however, that if the instrument be adjusted for 
ordinary distances, this defect is not serious, especially if a low 
power ocular or magnifying lens of 2 to 5 focal length be 
chosen. 

The eee image produced by the instrument as shown 
in the figures can be made upright by the use of a Rochon 
prism .pair directly in front of the ocular. The inverted 
image, however, is not a serious defect and equally good 
results can be obtained without the use of the extra prism pair, 
which encumbers the instrument and adds another adjustable 
part to-be looked after. 

Equation (3) shows that the accuracy of the instrument 
increases with the square of its length. It seems entirely 
feasible, therefore, to construct an instrument one or two 
meters in length on the principle of fig. 3, with which dis- 
tances of points within a radius of one or two kilometers or 
miles can be read off directly with considerable accuracy, thus 
accomplishing stadia measurements from the transit station 
without the aid of a rodman. 


Geophysical Laboratory, Carnegie Institution of Washington, 
Washington, D. C., June, 1908. 


5386 Wright—Kxplanation of Interference Phenomena. 


Arr. XLIX.—A Device to Aid in the Explanation of Inter- 
Ference Phenomena, by Frep. Kugene Wrieut. 


StupEnts of crystal optics, on taking up the subject of bire- 
fringence,; frequently encounter difficulty in forming a clear 
conception of the exact course of the ight waves through the 
erystals and the resultant interference phenomena when polar- 
izer and analyzer are used (crossed nicols). The small apparatus 
of fig. 1 has been found serviceable 
as a model in this connection, and 
facilitates to a certain degree the 
explanation of several of the phe- 
nomena of plane-polarized light. 

The device consists essentially of 
a brass rod divided into three parts, 
a, b, c, which are so connected that 
each one is revolvable for itself about 
the common axis; into each section, 
moreover, longitudinal slits have been 
eut and plates of thin, transparent 
celluloid inserted. The celluloid plate 
A represents the plane of vibration 
of lhght waves emerging from the 
lower nicol of the microscope; B is 
a celluloid model of the erystal sec- 
tion with its ellipsoidal axes at an 
angle of 45° to the plane of vibra- 
tion of the lower nicol; C, and C, 
represent the planes of the two waves 
emerging at right angles to each 
other from the crystal plate, the heht 
waves ©, being a definite distance 
ahead of C, as a result of the une- 
qual velocities of the two waves in their passage through the 
crystal B. On entering the upper nicol, these two waves are 
again reduced to the common planes of vibration D, and D,, 
the waves vibrating along D,, however, being destroyed by 
total reflection and those along D, only passing through. By 
the use of this model, it is not difficult to prove: (1) that two 
waves emerging from a refracting crystal at a distance apart of 
one or more whole wave lengths (phase difference zero) interfere 
mutually when reduced to the common plane of vibration, D,; 
(2) while two waves one-half wave length apart (in opposite 
phase) mutually strengthen each other when reduced to the 
common plane of vibration, D,, of the upper nicol; vice versa, 
if the plane D, be considered, the phenomena are exactly 


reversed—tfacts which are difficult to represent clearly without 


the aid of some such model. 


Geophysical Laboratory, Carnegie Institution of Washington, 
Washington, D. C. 


rad 


T. D. A. Cockerell— Descriptions of Tertiary Plants. 537 


* 


Arr. L.—Descriptions of Tertiary Plants, [1 ; by T. D. A. 


CocKERELL. 


Tue plants discussed below are all from the North American 
Miocene. They represent a flora containing many genera at 
that time widely spread over the Holarctic Region, but in 
later times driven southward, and to-day existing in much 


Rie: 2: 


Fie. 1. Geaster florissantensis. 


Ese 


el 


Fie. 2. Pinus sturgisi. 


more limited areas; some in Asia, others in various parts of 
America. They show very clearly that many of the ostensibly 
endemic genera of various regions may well have originated 
elsewhere, and are merely making their last stand where we 
now find them. 


Am. Jour. Sct.—Fourts Series, Vou. XXVI, No. 156.—Drcemper, 1908. 
38 


5388 7. D. A. Cockerell— Descriptions of Tertiary Plants. 


FUNGI. 


Geaster florissantensis sp. nov. Fig. 1. 


Diameter of “star” about 56™™, the segments about eight 
in number, five being visible, var iable i in form, the largest 20™™ 
long and about 114 broad at base, but one next to it only about 
7 broad ; color dark brown, texture apparently leathery, with- 
out any sion of venation. 

Florissant, at a new station on the hillside not far from 20 
(CHASE. Cockerell, 1908). It occurs on a slab with numerous 
remains of Typha lesquerewar Ckll., Ulmus hillie Lx., and 
other plants. The appearance is exactly that of a modern 
Geaster in the expanded condition, and the irregularity of the 
segments is unlike that of any calyx known to me. Geaster 
is, of course, common in Colorado to-day. 


GYMNOSPERMS. 


Pinus sturgist sp. nov. Fig. 2. 


Leaves in bundles of threes, apparently entire-margined, 
about 175™™" long and 13"™ broad, very straight, sharp-pointed. 
Two fibrovascular bundles are very distinct, being preserved 
as white lines. In all respects, the plant agrees very closely 
with the lving. P. teda L., of the Eastern and Southern 
States. 

Florissant; the type from Station 13 B (diss Gertrude 
Darling, 1908), but the species was also found, less weil pre- 
served, at various stations in 1907. ‘The species is dedicated 
to Dr. W. C. Sturgis, of the School of Forestry at Colorado 
College, in recognition of his contributions to Colorado botany. 
The fossil species of Pinus from Florissant must now be con- 
sidered to be three in number at least, separable as follows : 


Leaves in bundles of five ..-...-- P. wheeleri Ckll. (doubtfully 
recorded as P. palcostrobus (Ett.) Heer, by ao 
eames im punehes-ot-three: 222 52225). oe ee ee 
V; Weayesabouteliva"™ long 5.2 ee = alee is CkIl. 
Reaves-anouty 70"™ long {22 eee eee P. hambachi Kirchner. 


I formerly sunk P. hambachi under P. florissante Lx., which 
was based on a cone, but it must be restored, at least pro- 
visionally. 

Heyderia C. Koch. 


This genus, once widespread, is restricted to the Pacific 
coast region of North America (/leyderia decurrens (Torrey) 
C. Koch) and China (A. macrolepis = Libocedrus macrolepis 
Benth. and Hook. = Calocedrus macrolepis Kurz). At 


Sas ee 
{ 


T. D. A. Cockerell—Descriptions of Tertiary Plants. 539 


Florissant, Colorado, it is represented in the Miocene by 7. 
coloradensis Ckll., while in the ,Miocene of Europe, at 
Radoboj, Heyderi ia salicornioides (Libocedrus salicornioides 
Heer) is very well preserved. Other species, supposed to 
belong here, are from the Upper Cretaceous of Greenland 
and the Miocene of Spitzbergen. 


ANGIOSPERMS. 


Ailanthus americana sp. nov. Fig. 3. 


Samara about 38”™ long, 9 broad; seed 6™™ long and a little 
over 4 broad, placed with its long axis about 15 degrees from 


iDinsi. 4k. 


Fic. 3. Ailanthus 


. 1G. 4. Quercus knowltoniana. 
americana. FIG Quer tonia 


axis of samara; venation of wings well preserved, agreeing 
with that of A. glandulosa L.; apical part with a thickening 
along one side, as in Lesquereux, Oret. and Tert. Floras, 
oie ds a 

Florissant, Station 13 B, 1908. Type at University of 
Colorado. 

Adlanthus (wrongfully called Alzanthus in Knowlton’s Cat. 
Cret. and Tert. Pl.) is at present confined to Asia, with three 
species. It is well represented in the Tertiary beds of Europe, 
and is credited with two American Tertiary species, one from 
the Miocene of Oregon, the other from the Green River beds 
of Wyoming. The Oregon species is very distinct from ours ; 
that from Wyoming is based on a supposed leaflet with a 
remarkably long petiole, which seems to be doubtfully of this 


540 7. D. A. Cockerell—Descriptions of Tertiary Plants. 


genus. However, Lesquereux figures with his A. donge- 
petiolata a samara, which he says “may not represent the 
fruit of the same species,” but which is evidently very much 
like that from Florissant. The seed is more transverse, how- 
ever; the venation is not shown. 


Quercus knowltoniana sp. nov. Fig. 4. 


Acorn-cup 30™™ diameter; scales in about 10 rows, triangular, 
from about the fifth row sharp-pointed, but the more basal ones 
broad and angled rather than pointed; no visible marginal 
fringe. 

Florissant (d/rs. Charlotte Hill). WHolotype at Yale Univer- 
sity, Cat. No. 1005. I had retained this curious fossil for 
months, hoping to be able to determine it, but failing to 
recognize its relationships. Dr. I’. H. Knowlton recently visited 
my laboratory, and upon showing the fossil to him, he at once 
recognized what it was. Now that the fact has been pointed 
out it is so evident that the specimen is an acorn-cup that I do not 
understand my obtuseness on the subject. The species recalls 
the recent @. macrocarpa Michx., the cups of which grow to 
an even larger size. I have no leaf from the shale that I can 
refer to it. The cup was evidently widely open and shallow, 
not partially closed as it is in Q. lyrata. Fossil acorn-cups 
have been found in the Miocene of Europe (Q. palwocerris 
Sap., Y. subcrenata Sap.). 


Rosa ruskinigna sp. nov. Fig. 5. 


Represented by a bud about 16™™ long, and six in 
diameter. Hypanthium subglobose, no doubt producing a 
practically spherical fruit, covered with minute spines; sepals 
with very large and thick-stalked glands or gland hairs on the 
basal half, these very much larger than the spines of the 
hypanthium ; apical portion of sepals long, with three or four 
large lobes on each side. 

Florissant, Station 138 B (W. P. Cockerell, 1908). By the 
character of the hypanthium this is evidently related to Ltosa 
cherokeensis Donn., but the sepals are strongly lobed. Such a 
rose would have trifoliate leaves, and these should resemble 
those of /?. Azlliw Lx., at least to a considerable degree. As, 
however, it is impossible definitely to connect the bud with 
the leaves of /2. Allie (we have not found the latter), I give 
the former a distinctive name; dedicating it to John Ruskin, 
whose copy of Lindley’s “* Rosarum Monographia,” with many 
marginal notes, is in my library. 


T. D. A. Cockerell—Descriptions of Tertiary Plants. 541 


Hydrangea florissantia Ckll. 


Rhus rotundifolia Kirchner, Trans. St. Louis Acad., viii, 
p. 184, is the same thing. The name rotundifolia was much 
earlier used in ZZ ydrangea by Rafinesque. Kirchner’s type 
is, I believe, in the U. 8. N ational Museum. 


Sambucus newtoni sp.nov. Fig. 6. 


Leaflet (doubtless a lateral one) about 132™™ long and 26 
broad ; texture thin, this and the venation exactly as in living 


Fig. 6. 


Fic. d. Rosa ruskiniana. 


Fic. 6. Sambucus newtoni. 


species of Sambucus; form parallel-sided, rapidly narrowing 
apically to a sharp point, very much as in S. arborescens Nuttall ; 

margin with exceedingly minute denticulations, 4 to 5 in 5m. 
and even these evanescent on the basal half. 

Florissant, Station 13 B (George Newton Rohwer, 1908). 
The best side shows all but the base; the reverse lacks the 
apex, but shows nearly all of the base, which is substantially as 
in S. arborescens. This is the first American fossil Sambucus ; 
in Europe the genus is represented by flowers in amber. 

Lomatia acutiloba Lx. is on the same slab as Sambucus 
newtont. 


542 T. D. A. Cockerell 


Anona spoliata sp. nov. Fig. 7. 


Leaf apparently thick, oblong, entire, the blade 40™™ broad, 
and probably over 80 long (apex missing), the base broadly 
rounded, the midrib and petiole stout, the latter short, only 
about 9°™ long. Venation pinnate, the secondaries arising 
from the midrib at an angle mostly little less than a right 
angle, but varying in this respect, and gently curving upwards, 
ter “minating in submarginal arches connecting their tips, and 
variously enclosing areas of different shapes. Between the 
principal lateral veins are small and hardly noticeable ones, not 


~ 


ie 7 


Fic. 7. Anona spoliata. 


proceeding far from the midrib. In the shape of the leaf, 
the short petiole, and the venation, this is almost exactly lke 
the living Anona glabra L., of Florida. In one place two of 
the principal secondaries unite, as they sometimes do in A. 
glabra. 

Florissant, Station 13 B (Geo. WV. Rohwer, 1908). Sabina 
linguefolia (Lx.) Ckll. occurs on the same slab. Anona 
robusta Lx., from the Laramie (2) at Golden, Colorado, is a 
similar species, differing, however, in the character of the 
submarginal venation, which does not show the large enclosed 
areas. The resemblance of A. spoliata to A. robusta is, there- 
fore, not nearly so close as to A. glabra. The European A. 


me D. A. Cockerell—Descriptions of Tertiary Plants. 548 


elliptica Unger, from the Miocene of Radoboj, is close to A. 
spoliata in respect to the submarginal venation, but very 
different in the cuneate base, the leaf being very like that of 
Crescentia latifolia. 


Juglans leonis n.n. 


Juglans californica Lx., Mem. Mus. Comp. Zool. vi, 34, 
pl. ix, x (1878). Miocene of California. (Not J. californica 
S. Watson, Proc. Am. Acad., x, 349 (1875).) 


Rhus mense vn.n. 


Rhus- metopioides Lx., Mem. Mus. Comp. Zool. vi, 31 
(1878). Miocene of California. (Not “2. metoproides Turez., 
Bull. Soc. Nat. Mose., xxxi, 1, 468 (1858).) 


Salix merriaméi n.n. 


Salix elliptica Lx., Mem. Mus. Comp. Zool. vi, 10 (1878). 
Miocene of California. (Not S. elliptica Sleich., Ser., Ess. 
Saul., 44; cf. Steud., nom. (1841).) 

Lizyphus microphyllus Lx., and Magnolia lanceolata Lx., 
of the California Miocene, also bear preoccupied names. 


Weinmannia dubiosa Ckll. 


We found this at Stations 13 B and 14, at Florissant. The 
leaflets vary from five to seven. 


Robinia brittont sp.nov. Fig. 8. 


Represented by a leat, scarcely at all different from the 
living L. pseudacacia L. Five leaflets are preserved. Leaf- 
lets about 22™™ long and 94 broad, very briefly mucronate at 
apex, and with short petiolules about 2™™ long, which are as 
usual opposite, the pairs about 14™™ apart. From the first 
pair of leaflets to the insertion of the leaf is only 12™". The 
shortness of the petioles agrees best with /?. viscosa Vent., but 
the shape of the leaflets accords better with /?. pseudocacia. 
Florissant, Station 138 B (Jlelford Smith, 1908). Dedicated 
to Dr. N. L. Britton, who has contributed so much to our 
knowledge of American trees. 

Lobinia is to-day confined to America, but it is found fossil 
at Giningen and other European localities. 


Menyanthes coloradensis sp.nov. Fig. 9. 


Represented by a crown bearing five leaves, in form and 
appearance exceedingly like the living J/. trifoliata L., but 


544 7. D. A. Cockerell— Descriptions of Tertiary Plants. 


two of the leaves are entire. One of the basal leat-sheaths, 
curled backwards, is well preserved, and exactly as in J, 
trifoliata. The whole plant is much smaller than J/. trafo- 
liata ; the petioles of the better-developed leaves only about 
25m long, with leaflets about 30" long, and 9 to 10 broad. 
The prominent lateral or secondary veins are irregular, less 
numerous than in J/. ¢tr7folcata, and more or less strongly 
arched, with the concave side upwards. The entire leaves are 
broad-lanceolate to ovate, the largest being over 15™™ broad. 


Fie. 8. Fie. 9. 


Fic. 8. Robinia brittoni. Fig. 9. Menyanthes coloradensis. 


Florissant, Station 13 B (Geo. WV. Rohwer, 1098): also one 
found at the same place by Miss Gertrude Darling. Menyan- 
thes is to-day a monotypical genus of Holarctic “distribution. 
In the fossil state it is known, principally from capsules and 
seeds, from Greenland, Spitzbergen, and Central Europe. 
The occurrence of entire leaves on the fossil is of mterest in 
view of the fact that the allies of J/enyanthes are entire-leafed. 
Iasked Dr. L. N. Britton whether he had ever seen entire 
leaves on the living species: he replied that no such had ever 
come under his observation. The seedling of Jlenyanthes 
seems not to have been described. 


a 


Wright—Three Contact Minerals. 545 


Arr. LI1—On Three Contact Minerals from Velardena, 
Durango, Mexico. (Gehlenite, Spurrite and Hillebrand- 
ite); by Prep Eugene WriGaHt. 


Dvurine the summer of 1907, a geologic examination of the 
Velardefia mining district in Mexico was made by Mr. J. E. 
Spurr, assisted by Mr. G. H. Garrey. Several of the thin 
sections of the material there gathered were sent to the writer 
for examination, and in one of these a mineral with peculiar 
optic properties was observed. At the suggestion of the writer 
an adequate collection of the rock from which the thin section 
had been cut, was then made by Mr. Garrey, and in this col- 
lection the three minerals to be described below were found. 
Two of these minerals proved to be new mineral species, sili- 
cates of interesting composition, while the third, gehlenite, is 
apparently novel for this continent. All three are contact 
minerals, formed near the junction of altered limestone and 
intrusive basic diorite and their relations to the contact and 
conditions of formation have been carefully studied by Messrs. 
Spurr and Garrey. As the results of their extended investi- 
gation will soon be ready tor publication it has not been 
deemed necessary to consider in detail in this present paper 
conditions of occurrence and formation of these minerals 
and their relations to the ore deposits in general. 

The chemical analyses of the three minerals and their specific 
gravity determinations were made by Dr. E. T. Allen of the 
Geophysical Laboratory, and to him the writer is deeply 
indebted for the courtesy. 


Gehlenite.* 


This mineral occurs in massive granular aggregates, usually 
dark gray or gray-black in color, from minute inclusions of 
magnetite and other particles. Rarely small pieces of gehlen- 
ite of amber-yellow color and free from magnetite inclusions 
were observed. The grains are rounded in outline and not 
suitable for crystallographic measurement. The physical and 
optical properties, however, are similar to those recorded for 
gehlenite from other localities, and the chemical composition 
also agrees as well with the prescribed formula as the analyses 
of the type material. 

Crystal system, probably tetragonal, judging from the cleay- 
age, which is imperfect after 001 and much less well marked 
after a prism. Fracture, uneven and irregular, conchoidal to 
splintery. Hardness, between 5 and 6, about 5°5. Luster, 


* Type specimen from contact aureole of the Terneras intrusion, Velardefia, 
Durango, Mexico. 


546 Wright—Three Contact Minerals. 


resinous to greasy. Translucent to transparent in thin flakes ; 
in large masses, sub-transparent to opaque. Streak white to 
pale gray, the gray probably due to fine magnetite inclusions. 

In the thin section, the gehlenite appears weakly birefract- 
ing with comparativ ‘ely high refractive index. Maegnetite 
inclusions are abundant and often show crystal outline. The 
magnetite also occurs, fillmg cleavage and fracture cracks in 
the gehlenite and evidently was precipitated both before, dur- 
ing and after the crystallization of the gehlenite. In certain 
of the sections the magnetite crystals showed a distinet tend- 
ency to an arrangement. parallel with the first and second order 
prism faces. Round earthy spots also occur filled with earthy 
matter and are apparently of secondary origin, although they 
may possibly be weathered original spherulites of some mineral 
earlier than the gehlenite. 

In the thin section the basal cleavage is well marked and 
after it the crystals are often developed. in thick tabular form. 
In thick slides the interference color becomes intensely yellow, 
reminding one somewhat of the peculiar yellow interference 
tints of certain epidotes. 

In convergent polarized light the interference cross is wide 
and uniaxial. Optically negative. On one section the bire- 
fringence was measured at w—e = 00055. The refractive 
indices were measured directly on an Abbé Pulfrich total 
refractometer in Na light and found to be » = 1°666 + -003 and 
e = 1°661+:003. These values were obtained by using a 
polished plate of the granular material, and the refractive dices 
could not be determined under such conditions with an accuracy 
greater than + *008. 

The specitic gravity at 25° was determined on two samples 
by pycnometric methods at 38:°029 and 3:049 with an aver- 
age = 3°039. Part of this variability is probably the result of 
differences in relative amounts of inclusions. 

On uncovering a thin section and treating the exposed sur- 
face with weak hydrochloric acid and then, after thorough 
rinsing, with a solution of fuchsin, the eehlenite was found 
to have gelatinized slightly. This fact was corroborated by 
a chemical test with powdered material, which was found to 
gelatinize readily. 

The following chemical analysis does not agree with any 
simple formula and a comparison of other gehlenite analyses 
indicates that under the term gehlenite a solid solution series 
between several different end members is probably included. 

Compared with the other analyses, the Velardefa gehlenite 
is somewhat lower in silica and magnesia, and higher in 
alumina and lime, but otherwise very similar, and is essentially 
a calcium aluminum silicate. 


Wright—Three Contact Minerals. 547 


CHEMICAL ANALYSIS. 


sf la 2 3 4 
See re 26°33 "A359 DOTS 28°59 31°40 
Ors eo 03 "0004 
1.0 ee ree OS 2722 22°02 99°32 22°32 
20 Se 1°43 0089 3°22 
MeO “50 0070 1°82 0°3 0°03 
Win Og oo. ‘01 0001 eee 0°50 0:96 
eee Ss 9°44 "0605 3°88 ia 10°02 
BOS. 89755 "7050 37°90 36°76 30°92 
AO) ee. ol "0085 LPS 0°40 al 
ERO ‘10 0009 bodies 0°21 0°12 
PieOe 8 2: 1°85 0103 1:28 eae 
dS a mon Oe 3°25 3°85 
CO none eats le Jae age 


100°27 1°5047 99°90 100°18 100°79 


1. Gehlenite, Velardefia, Mexico. HK. T. Allen analyst. 

la. Molecular proportions of 1. 

2. Gehlenite, Monzoni, Rammelsberg, Mineralchem., 1875, 604. 

3. Gehlenite, Falkirk, Sweden. Edg. Jackson in Bauermann, 
Journ. Iron and Steel Inst., 1886, i, 88. 

4. Gehlenite, Clarence, J. H. L. Vogt, Stud. Slagger, Stock- 
holm, 1884, 138. 


Before the blowpipe thin slivers of this mineral melt down 
with difficulty to dark, non-transparent beads, give a pronounced 
calcium flame reaction and glow intensely. 

In the hand specimens, gehlenite occurs either practically 
alone except for magnetite inclusions, or together with spur- 
rite, yellow garnet and calcite. Later veinlets consisting 
chietly of calcite were noted occasionally, cross cutting the 
specimens. 

So far as the writer has been able to ascertain from the avail- 
able literature, this occurrence is the first recorded for gehlen- 
ite on this continent. 


Spurrite.* 


This mineral, like gehlenite, occurs in granular masses which 
at first glance might be mistaken for crystallized marble, 
especially since the cleavage faces frequently glisten in the 
sunlight like those of calcite. No crystals were observed and 
the only goniometric measurements possible were made on 
cleavage fragments. Two cleavages were observed, the one 
good and the second much less perfect. The reflection signals 
from these faces were not of equal value and the cleavage 


*Type specimen from contact aureole of Terneras intrusion, Velardefia, 
Durango, Mexico. 


548 Wright—Three Contact Minerals. 


angle could only be obtained approximately ; the best average 
of the results is 79° with a probable error of at least + 4°. 
Fracture uneven to splintery. Brittle. Hardness, about is 
Luster, vitreous to resinous. Color, pale gray with tints of 
blue or yellow to colorless. Transparent to translucent. 
Streak, white. 

On the hand Specimens a weathering or alteration crust, 
consisting chiefly of finely divided carbonate, occurs not infre- 
quently. Im the thin section the spurrite is well defined 
optically and is excellent material for optical work. 

From the relations of the optic properties to the erystallo- 
graphie it is highly probable that spurrite is monoclinic and 


that the cleavage faces are parallel with the orthodiagonal (} 
axis). If the good cleavage plane be called the basal pinacoid, 
the optical orientation is apparently the following: 6= 4; @:¢t, 
very small and possibly zero, the cleavage cracks not being 
sufficiently perfect for decisive measurements. : 

Twinning after both 001 and polysynthetic twinning after 
orthodomes at angles of 56° to 58° with the twinning lines of 
001 occur, and occasionally divide the field into sextants of 
the same birefringence and all cut approximately normal to 
the acute bisectrix, the plane of the optic axes in the different 
sextants occupying different positions, as shown in the accom- 
panying sketches. (Figs. 1a, 10.) 

The polysynthetic lamellae are often extremely fine and 
resemble albite lamellae very closely. On a section almost 
precisely normal to the acute bisectrix the angle between the 


Wright—Three Contact Minerals. 549 


plane of the optic axes and the fine twinning lamellae was 
measured at 57°°5 in sodium light. On this thick plate crossed 
dispersion was unusually clearly marked, the angle between the 
plane of the optic axes for red lithium light being about 57°-6, 
and for green thalinm light 57°-1. These measurements indi- 
cate a dispersion of the bisectrices ¢p:¢,: in the plane of sym- 
metry of about 0°15°. At the same time a slight dispersion of 
the optic axes was noticeable with 2Ep > 2Ky, 

The optic axial angle was measured on a number of different 
sections by the use of the double screw micrometer ocular and 
also of the universal stage, the average being 2V = 39°°5,+ 1°; 
whence 2E= 70°. Owing to the strong birefringence the 
interference figure is unusually well marked even in normal 
thin sections. The refractive dices were measured in sodium 
light on several different plates on an Abbe-Pulfrich total 
refractometer with reducing attachment, the different refractive 
index lines from the polished plates being clearly marked and 
easy to follow: 


eae —— 1-679) 2-002 y= © = WSY 
BNa = 1674 + -002 y — B = ‘005 
a Na = 1°640 + :002 B—a = ‘034 


From these values the calculated optical axial angle is 
2V = 41° 12’, which agrees fairly well with the measured value. 
Optical character negative. 

The birefringence values were checked by direct measure- 
ments on plates in the thin section and closely accordant results 
obtained.* ; 

YG == a0 
B — a = :036 


In the thin section spurrite is recognized by its high bire- 
fringence, imperfect cleavage and small optic axial angle with 
negative optical character and in thick sections noticeable 
crossed dispersion. 

Still further evidence on the crystal system of spurrite was 
gathered from etch figures on the good cleavage face. 
Cleavage lakes were immersed for 10 seconds in cold 5 per 
cent hydrochloric acid and the etch figures of fig. 2 obtained. 

Many of these figures appear asymmetrical but the upper 
terminal endings are so variable and influenced by adjacent 
cleavage cracks to such an extent that the general symmetrical 
aspect of the figure with respect to a vertical plane of sym- 
metry may have thus been disturbed. It must be admitted, 
however, that the etch figures may be actually asymmetric, in 


* For these direct measurements of birefringence in the thin section the 
writer is indebted to Mr. E. S. Larsen, Jr., of the Geophysical Laboratory. 


550 


which case spurrite is triclinic instead of monoclinic; the rela- 
tions of the optic properties for different wave-lengths are then 


Fig. 2.—Etch figures on good cleavage face of spurrite produced by 10 sec. 


Wright—Three Contact Minerals. 


Fie. 2. 


immersion in cold 5 per cent HC1. 


99°85 


Magnification 150 diameters. 


la 2 
‘4467 27°13 
0001. 

‘0038 
-0007* 
0004 
0058 
email 62°98 
‘0008 
+2919 9°89 
1°7909 100-00 


* Calculated as Fe.Os;. 


. Spurrite, Velardefia, Durango, Mexico, E. T. Allen ones 


ty Molecular proportions of 1. 


2, Theoretical percentage weight composition for the formula 


2Ca,SiO,.CaCO,. 


Wright— Three Contact Minerals. 551 


such as to simulate very closely crossed dispersion of the mono- 
clinic system. 

Before the blowpipe spurrite shows strong calcium flame 
reaction, loses its glassy lustre, becomes white and porcelain- 
like but does not fuse even in thin splinters. 

Spurrite effervesces readily with weak hydrochloric acid, 
dissolves completely and gelatinizes thoroughly. The chemical 
analysis was made on carefully selected material. 

The agreement of the analyzed material with the formula 
2Ca,SiO,.CaCO, is remarkably close and in view of the purity 
of the material analyzed can leave no doubt that spurrite is a 
compound of the above formula. 

The specific gravity at 25° was determined with pyeno- 
meter, both in xylene and in water, and the following results 
obtained : 

Spec. gr. at 25° in xylene = 3:013 


3014 
(74 ce 66 6¢ 7 ooo 
water = 3-016 


Average spec. gr. at 25° = 3°014 


Spurrite occurs in the hand specimens either in pure, unal- 

tered state, except for minute inclusions of magnetite, or 
together with yellow garnet, calcite and gehlenite. Its weather- 
ing products consist chiefly of carbonates in microscopic aggre- 
gates, which appear first along cracks and cleavage planes in 
the altering mineral. 

Through the courtesy of Mr. E. S$. Shepherd of the Geo- 
physical Laboratory, several experiments were made to repro- 
duce spurrite artificially by heating ten per cent solutions of 
sodium chloride with pure Ca,SiO, and CaCO, in finely divided 
state and in different proportions in silver-lined steel bombs 
from 6 to 9 days at temperatures of 350° to 400°. Although 
minute, well-shaped crystals were obtained in many of the 
preparations with refractive indices a and y, practically identi- 
cal with those of spurrite, the symmetry was orthorhombic 
and therefore not that of spurrite. Synthetic experiments on 
this compound are still in progress. 

This mineral is named in honor of Mr. J. E. Spurr of New 
York, who collected the original material and who has done 
much to further existing knowledge of ore deposits and their 
accompanying minerals. 


Hillebrandite.* 


Hillebrandite, unlike spurrite and gehlenite, is distinctly a 
fibrous mineral and occurs in aggregates often as radial spheru- 


* Type specimens from the 8th level of the Terneras Mine, Velardefia, 
Durango, Mexico. 


552 Wright-— Three Contact Minerals. 


lites, the individual fibers of which are difficult to separate 
satisfactorily, and rarely measures *5™™ in length. In the 
hand specimen, especially when examined with a lens, these 
fibers tend to produce a faint silky luster on the otherwise vit- 
reous to porcelain-like mass. Cleavage, so far as could be 
observed, prismatic. Brittle. Hardness between 5 and 6, 
about 5°5. Color, pure porcelain white, often with faint tinge 
of pale green. Translucent in small chips. Streak, white. 

Under the microscope the optic properties are those of 
ageregates of fibers, often in approximately parallel orienta- 
tion, rather than of a single fiber. As a result the optical 
data are not easy to determine with great accuracy, although 
certain features of the mineral are so characteristic that its 
determination as such is a relatively simple matter. 

The refractive indices y and a were measured in sodium 
light on an Abbé-Pulfrich total refractometer on a polished 
plate of the mineral. It has been found by experience that 
even in the case of such fine-grained masses as hillebrandite, 
the phenomena in sodium light on the refractometer are sutfiici- 
ently distinct, when reducing attachment is used, to permit a 
fairly accurate determination of the two limiting curves y and 
a, although in the flood of hght from the different grains, the 
medium refractive index line does not appear with sufficient 
distinctness to allow of its determination. On such a plate 
the refractive indices were found to be 


I-612 ee 7008 
1605 + °005 


y 
a 


lI Il 


The birefringence is medium to weak, but difficult to deter- 
mine directly because of interweaving of overlapping fibers. 

The extinction is parallel, the ellipsoidal axis (c) being 
invariably parallel with the fiber direction which at the same 
time is the cleavage direction. The optic axial angie is not 
very large, 2Ep being possibly between 60° to 80°, while the 
dispersion of the optic axes is unusually strong and gives rise 
to peculiar, abnormal blue interference colors resembling those 
in certain epidotes and characteristic of hillebrandite. The 
optic character is negative with 2H, > 2K o. The plane of 
the optic axes was found to vary, being in the one plate 
parallel with the fiber direction and in the next perpendicular 
to the same, an abnormal phenomenon which may be due in 
whole or in part to the disturbing influence of the interlacing 
fibers which tend to veil the optic phenomena and often most 
effectively. On a section normal to the acute bisectrix the 
plane of the optic axes was parallel with the cleavage and 
direction of elongation. 


Wright—Three Contact Minerals. 553 


From these optical and crystallographic data, it appears that 
hillebrandite is orthorhombic with possibly c=c, a@=a and 
cleavage after 110 (2). Its most characteristic optic features 
are: refractive index about 1°61, birefringence weak to medium, 
2E medium with very strong axial dispersion 2E, > 2E , which 
in parallel ight gives rise to abnormal blue interference tints 
which are readily recognized. Optical character, negative. 

The absence of crystallographic faces of any degree of per- 
fection precluded any ewe at etching which might have 
been made. 

The specific gravity at 25° was determined by pycnometer 
with water at 2-692, and also in xylene at 2°692. The check 
determination in xylene was made because the analysis of 
hillebrandite shows it to have been slightly hydrolized. 

In hydrochloric acid (1:1) hillebrandite separates some 
silica at once but enters otherwise into solution. Hillebrandite 
decomposes very slowly with cold water as the test by adding 
a few drops of phenolphthaline to the mixture indicates. 

*~ Before the blowpipe thin splinters of hillebrandite fuse 
down with difficulty to.a colorless glassy bead, at the same 


time giving a pone calcium flame reaction and glowing 
briskly. 


CHEMICAL ANALYSIS. 


1 1a 2 
STC SSS nen et 32°59 "5398 O74 
“Lo Le aia oe WOES a eine "02 "00038 
WE ee 23 0023 
ae SO RE: 15 0009* 
pte) Fata Sil oc ce ‘Ol 0001 
Mie een yen ‘O4 0010 
pee a ate pe ip G 1°0296 58°81 
a OS ee fae AS 03 0005 
HRY ig gi DI once 05 0005 
EM eer ee ee _ 9°36 5019 9°45 
Pipa ie Meee th Ui none 
9G Dee RSS a ee eee ee none 


100°24 2°0769  100°00 


1. Hillebrandite, Terneras Mine, Velardefia, Durango, Mexico, 
K. T. Allen analyst. 
1a. Molecular proportions of 1. 
2, Percentage weight composition of formula H,O.2 CaO, 8i0,,. 
* Calculated as Fe20s. 


Am. Jour. Sc1.—Fourts Series, Vou. XX VI, No. 156.—DrEcremBER, 1908. 
39 


554 Wright—Three Contact Minerals. 


This analysis agrees closely with the formula Ca,SiO,.H,O,* 
it being a little higher in silica and lower in lime, a condition 
which is evidently due to a slight leaching of the lime. The 


water of the analysis was determined by loss in weight, the 


figure given being the average of two determinations, 9°34 
and 9°39. By absorption by calcium chloride plus the little 
obtained at 110° the result was 9:18. The first figures, how- 
ever, are more accurate. 

Hillebrandite occurs usually with few inclusions and even 
magnetite is rare. Occasionally small grains of carbonate, 
yellow garnet and wollastonite occur with it and also earthy 
material of a secondary nature. Veinlets of wollastonite 
traversed several of the hand specimens and in each case the 
direction of elongation of the wollastonite fibers was normal 
to the vein walls. 

Experiments to produce hillebrandite synthetically have 
thus far not proved successful. 

The above optical and chemical data show beyond question 
that hillebrandite is a true chemical compound of unique 
chemical composition. It is with great pleasure, therefore, 
that the writer suggests the above name as a token of appre- 
ciation of the fundamental researches of Dr. W. F. Hillebrand 
of the U. 8. Geological Survey in mineralogical chemistry. 


Geophysical Laboratory. 
Carnegie Institution of Washington, 
Washington, D. C. 
June, 1908. 


* This formula may also be written CaSiOs. Ca(OH). or simply H.O. 
2CaO.SiOz. 


Drushel—Estimation of Potassium in Animal Fluids. 555 


Art. LIL—Zhe Volumetric Estemation of Potassium in 
Animal Fluids; by W. A. Drusaet. 


[Contributions from the Kent Chemical Laboratory of Yale Univ.—excii. ] 


Tue distribution of potassium in plant and animal tissues 
has been studied by Macallum* and others. Macallum pre- 
cipitated potassium in place as potassium sodium cobalti-nitrite, 
an insoluble potassium salt which by its crystalline form and 
color is easily recognizable under the microscope. To study 
the function of potassium in the animal organism it is desirable 
to have a simple and rapid method for its estimation in the 
various tissues and fluids. A number of quantitative methods 
have been proposed which, however, are not wholly free from 
objections. 

M. Kretschy, m 1876, after having carefully studied the 
several indirect methods for potassium and sodium in the 
presence of each other, finally adopted a modification of the 
chlorplatinate method for potassium in the presence of rela- 
tively large amounts of sodium in physiological work. He 
worked with quantities of potassium ranging from 3 mgrm. to 
120 mgrm., precipitating it as the chlorplatinate in the usual 
manner. The washed and dried precipitate was carefully 
ignited, the residue extracted with water and the extract evapor- 
ated to dryness. This residue was gently ignited and weighed 
as potassium chloride. A small amount of platinum usually 
passed through the filter, giving a result which was too high 
for potassium chloride. To avoid error on this account the 
weighed potassium chloride was dissolved in water, any residue 
of platinum filtered off on ashless paper, ignited and weighed, 
and the necessary correction made in the weight of the potas- 
sium chloride. 

Some years Jater Lehmann,t Bunge,{ Heintz,§ and Pribram 
and Gregor| used different modifications of the Fresenius chlor- 
platinate method for the estimation of potassium in urine. In 
the methods of Lehmann, Bunge, and Pribram and Gregor the 
sulphate radical was removed by an excess of barium hydrox- 
ide or barium chloride ;. subsequently the excess of barium was 
removed by ammonium carbonate and ammonium hydroxide, 
or in case of barium hydroxide by carbon dioxide. Lehmann 
evaporated the urine with ammonium sulphate before ashing 
the residue, while Bunge treated the urine directly with bar- 
inm hydroxide. Pribram and Gregor oxidized the organic 
matter by heating the urine, acidified with sulphuric acid, to 

* Jour. of Physiol., xxxii, 95(London). +Zeitschr. physiol. Chem., viii, 508. 


t Zeitschr. Biologie, ix, 139. § Pogg. Ann., lxvi, 133 
|| Zeitschr. anal. Chem., xxxviii, 409. 


556 Drushel 


the boiling point and adding an excess of potassium free barium 
permanganate. Heintz treated 20°™* to 30™* of clear urine 
with chlorplatinic acid and a threefold volume of a 1:4 ether 
and absolute alcohol mixture. After standing 24 hours the 
precipitate was filtered off, washed with alcohol, dried, ignited 
and weighed. The residue was then extracted with hot water 
and again dried and weighed. The amount of potassium 
chloride was found by taking the difference of the weights. 

It has been repeatedly shown that appreciable amounts of the 
alkal salts are carried down by barium sulphate, which can 
not be completely removed by washing. This objection applies: 
to all of the methods in which the sulphate radical is removed 
by means. of a barium salt. The loss of alkalis is especially 
appreciable where a large amount of barium sulphate is formed 
in the presence of relatively small amounts of the alkali salts. 

In 1898 K. Gilbert devised a method for.the separation of 
potassium which does not require the previous removal of the 
sulphate radical. He treated a potassium salt solution free 
from mineral acids with an excess of sodium cobalti-nitrite acidi- 
fied with acetic acid. After standing from 12 to 20 hours the 
potassium was quantitatively separated out as potassium sodi- 
um cobaltinitrite which could be freely washed with cold 
water without an appreciable loss. Gilbert decomposed this 
precipitate by heating with dilute hydrochloric acid and esti- 
mated the potassium as the perchlorate or chlorplatinate. 

A few years later Autenrieth and Bernheim* used Gilbert’s 
method for separating potassium in urine, subsequently esti- 
mating the potassium as the perchlorate. They used 6° to 
10°™* of concentrated sodium cobalti-nitrite to precipitate the 
potassium in 50%* of urine. At this dilution it had been 
shown by Gilbert that the potassium is quantitatively precipi- 
tated and that the precipitate is apparently of indefinite com- 
position. In 1900, however, Adie and Wood* found that with 
a sufficiently high concentration of the reagent and of the 
potassium salt solution a precipitate of definite composition, 
represented by the formula K,NaCo(NO,),.H,O, is obtained. 
They further found that by decomposing this precipitate with 
boiling dilute sodium hydroxide and titrating the nitrites with 
standard potassium permanganate the potassium may be esti- 
mated with a fair degree of accuracy. 

In a previous paper* from this laboratory it was shown that 
it is unnecessary, after adding the cobalti-nitrite reagent, to 
let the mixture stand from 12 to 20 hours, if it is evaporated 
nearly to dryness, also that the precipitate may be directly oxi- 
dized with potassium permanganate without previously decom- 


* Zeitschr. physiol. Chem., xxxvii, 39. + Jour. Chem. Soc., Ixxvii, 1076. 
t This Journal, xxiv, 453, 1907. 


Drushel— Estimation of Potassium in Animai Fluids. 557 


posing it with boiling sodium hydroxide. Later it was found 
that a half saturated sodium chloride solution is preferable to 
cold water for washing the precipitate since it permits the 
use of a coarser asbestos felt in filtering without danger of loss. 

The method used in the work on animal fluids is as follows: 
A potassium salt solution was obtained free from mineral acids 
and ammonia salts and treated with a liberal excess of concen- 
trated sodium cobalti-nitrite in an evaporating dish. The mix- 
ture was evaporated to a pasty condition over the steam bath. 
After cooling the residue it was stirred up with enough cold 
water to dissolve the excess of sodium cobaltinitrite. The 
precipitate was permitted to settle a few minutes, then it was 
filtered on asbestos in a perforated crucible and washed with 
the sodium chloride solution until the filtrate came through 
colorless. The precipitate and felt were transferred by means 
of a spray of water and a stirring rod to a beaker containing a 
measured amount (being an excess) of standard decinormal or 
fifth normal potassium permanganate, diluted about ten times 
and heated nearly to boiling. The permanganate solution was 
kept hot and stirred to facilitate the solution and oxidation of 
the precipitate, the oxidation being completed by adding 5°™* to 
10°™* of dilute sulphuric acid and stirring for a minute or two. 
The excess of permanganate was then bleached by a measured 
amount of standard decinormal oxalic acid, and the solution 
titrated to color with standard permanganate. In this process 
the cobalt is reduced to the bivalent condition and the nitrites 
oxidized to nitrates, from which by a simple calculation it is 
found that one cubic centimeter of strictly decinormal perman- 
ganate is equivalent to 0°000857 grm. of K,O. 

The modified Lindo-Gladding method was used as a control 
in the experimental work of this paper. The potassium was 
obtained as the sulphate in the presence of sodium sulphate, 
and possibly traces of calcium and magnesium sulphate. The’ 
solution of these sulphates was treated with an excess of chlor- 
platinic acid, evaporated nearly to dryness, and the precipitate 
washed free from the excess of chlorplatinic acid with 85 per 
cent alcohol. The precipitate was then washed three or four 
times with a 20 per cent solution of ammonium chloride satur- 
ated with potassium chlorplatinate, and finally again two or 
three times with 85 per cent alcohol. By this treatment the 
sodium sulphate and the small amounts of calcium sulphate 
and magnesium sulphate are completely removed. 


A. Potassium in urine. 


The following table gives approximately the amount of the 
constituents present in a day’s excretion of urine of an adult 
in normal health and on an ordinary mixed diet: 


558 Drushel 


Estemation of Potassium in Animal Fluids. 


1h hiteroae Ge aye at Us 2 to 4 grm. Urea vist Oh ae grm. 
NaCl et eos ie tO a Urie acid 78 0:7 

CaO and MgO ..-..-- Or84,,4° Creatinine _...- Ib ee 
INGER ee 2 ee perenne ORT Hippuric acid 0°71 
ifs a (phosphates) .-. 1:5 “ Other organic -- 

H,SO, (sulphates) (222.275 |S bodies -..2/)- 32a 


In this list of constituents ammonia and the organic bodies, 
especially urea, are the only ones which should interfere with 
the volumetric method as previously described. To remove 
these bodies without the loss of potassium is apparently the 
only new problem. 

In the experiments recorded in Table 1 aliquot portions of 
urine of 10 to 50 cubic centimeters each were measured with 
pipettes or a burette into small platinum evaporating dishes, 
and evaporated to dryness over the steam bath in a good 
draught hood. ‘The residues of the aliquots of the first speci- 
men were treated with 5°™° of concentrated nitric acid and 
again evaporated to dryness. ‘These residues were then moist- 
ened with concentrated sulphuric acid and ignited to a white 
ash beginning with a low flame and increasing the heat until 
the organic matter was burned off, and the ammonium sulphate 
and excess of sulphuric acid completely removed. In subse- 
quent experiments it was found more expeditious to treat the 
dried urine residue with 5° to 10°™ of a 9:1 nitric-sulphuric 
acid mixture, in a covered evaporating dish, removing the 
cover when the first violent oxidation is over, evaporating to 
dryness and igniting without the further addition of sulphuric 
acid. By this treatment the ignition of the residue from 50°™ 
of urine could be readily made in 30 minutes without loss of 
material. The residue thus prepared was treated with a little 
water and a few drops of acetic acid to dissolve the alkalis. 
Without filtering about 10™> of concentrated sodium cobalti- 
‘nitrite were added and the mixture evaporated to a pasty 
condition. From this point the process was carried out as 
previously described. In the control experiments the phos- 
phoric acid was removed by a slight excess of calcium hydroxide, 
and the calcium by ammonium oxalate, before the ignition of 
the residue. 

The results obtained by the two methods from a number of 
different specimens of human urine are given in the following 
table. 


B. Potassium in circulatory fluids. 


An additional difficulty presents itself here in the presence 
of a large amount of protein material which can not be removed 
by coagulation and filtration without a considerable loss of 


* Taken from Hammerstein’s Physiological Chemistry, (Mandel’s Trans- 
lation), 5th ed.; p. 628. 


Drushel—Estimation of Potassium in Animal Fluids. 559 


T 
Urine 
taken Sp. gr. 
cm? 

PC 1) 10 1018 
(2) 10 oe 
(en ei ae 
(4) 10 at 

EE CL) 10 1°022 
(2) 10 Lee 
(3) 10 eae 
(4) 10 eure 
ill (1) 10 1°023 
(2) 10 Biss 
(3) 10 ceaee rs 
(4) 10 Cee 
NCL) 10 1°024 
(2) 10 ee 
(3) 10 eee 
(4) 10 eee 
Urine 
taken Sp. gr 
cm? 

V (1) 10 1°025 
(oy 110 a 
(3) 10 apa 
(4) 10 rape 

VI (1) 25 1°025 

(2) 25 ass ys 

(3) 25 FEN 

VIL (1) 20 ~—*1°025 
(2) 20 a 

(3) 20 ais ee 

VIII (1) 20 ~—«*i1:-024 
(2) 20 nite a 

(3) 20 Sones 

(4) 20 ee 

EX.(Y) 25 1°018 

(2) 50 aE 

(3) 50 a Ye 

(4) 25 ee 


ABLE I, 
A 


K found 
grm. 
0°012 
0°0122 
0°0123 
0°0131 


0°0180 
0°0178 
0°0178 
00171 


0°0241 
0°0242 
0°0238 
0°0231 


0°0241 
0°0248 
0°0242 
0°0243 


K found 
germ. 


0°0293 
0°0292 
0°0293 
—0°0292 


0°0740 
0°0747 
0°0740 


0°0757 
0°0752 
0:0764 


00663 
0°0662 
0°0663 
0°0662 


K found 
per cent. 
0°12 
0°12 
0°12 
0°13 


Oris 
0-17 
Ort 7 
0°17 


0°24 
0°24 
0°23 
0°23 


0°24 
0°24 
0°24 
0°24 


0°0425 
0°0839 
0°08438 
0°0424 


Method 
Vol. 
66 


Grav. 
6 


K in 
24 hrs. 
erm. 


218 
Pe 
2°78 
20k 


Method 


Vol. 


Grav. 
(44 


Vol. 
Grav. 
Vol. 


Vol. 
Grav. 
Vol. 


Vol. 


6¢ 


Grav. 


66 


Vol. 


52 Grav. 
53 Vol. 


Grav. 


560 Drushel—Kstumation of Potassium im Animal F luids. 


potassium. This is particularly true of the blood, where most 
of the potassium is intimately associated with the protein of 
the corpuscles. It is necessary therefore to decompose the 
protein material by oxidation. 

The nitric-sulphuric acid mixture was s first used for oxidizing 
the dried blood residue, but was found to work less satisfae- 
torily than in the case of urine. In the ignition of the blood 
residue oxidized in this way there was apparently a greater 
tendency to spatter, probably due to the presence of the sul- 
phuric acid. When, however, nitric acid alone was used for 
the oxidation, there was a tendency for the residue to burn off 
explosively on ignition. The analytical results from the first 
specimen given in Table II were obtained by treating weighed 
portions of defibrinated blood with about 2°° of bromine 
in covered evaporating dishes, allowing them to remain in a 
warm place under the hood for about one hour. The excess 
of bromine was then removed over the steam bath, the residue 
evaporated to dryness, and ignited sufficiently to char the 
organic matter. The residue was thoroughly extracted with 
hot water and the extract evaporated off with a few drops of: 
sulphuric acid. The residue was then ignited to remove any 
ammonium salt which might have escaped the action of the 
bromine and any organic matter which might have passed 
through the filter. 

The second specimen was a half liter of clotted sheep’s 
blood, from which no homogeneous portions could be taken. 
The whole mass was, therefore, evaporated over a steam bath 
and oxidized with concentrated nitric acid, getting everything 
into solution except a little lipoid material. The solution was 
made up to the original volume, and aliquots of 25°", repre- 
senting 30 grm. of blood, were ‘pipetted off. These portions 
were evaporated to dryness and gently ignited, but not suffi- 
ciently to produce explosive decomposition. The residues 
were then moistened with concentrated sulphuric acid and 
_ ignited carefully to remove the organic matter and the ammon- 
ium salts. For the results of the second and third divisions of 
Table II weighed portions of serum and lymph were similarly 
oxidized with nitric acid and subsequently ignited with a little 
sulphuric acid. The potassium in all the residues thus obtained 
was estimated gravimetrically or volumetrically as previously 
described. The results obtained for potassium in circulating 
fluids are given in the following table. 


C. Potassium in milk. 


In addition to lactose and the inorganic salts, milk contains 
a large amount of protein, chiefly casein, and varying amounts 
of fat. The ease with which casein is precipitated suggested 
the possibility of making a complete separation of the inorganic 
salts and casein, but it was found that after thoroughly wash- 


Drushel—Estimation of Potassium in Animal Fluids. 561 


Taste II. 
Amount K,0 found 
Nature of taken a ae 
fluid erm. erm. per cent Method 
ay Defibrinated 10°89 0°0227 0-21 Gray. 
(2) pig’s blood - 11°21 0°0228 0°20 Vol. 
(3) 2 ere 20°33 00391 0°19 a: 
“reels 10°16 00208 0°21 “ 
5) 5 ees Saga 10°85 00211 0°20 ss 
"5 en an 11:03 0:0936 0-21 “ 

Il (1) Sheep’s blood 30-00 0°0174 0°058 Grav. 
“Se ee 30:00 00179 0:060 Vol. 
Seberete ee 230-00) < 00181. 0-060. ‘Grav. 
a en 30°00 0°0181 0°060 Vol. 

5) ee SR aes eee 30°00 0°0180 0-060 oo 
III (1) Serum of dog’s 
blood _. 1011 0:0024 0°024 Vol. 
(2) a ip ee eee 10°04 0°0024 0°024 Gravy. 
2). See 10:07, )°:0-0023- ¢ 0-084" Vol. 
IV (1) Dog’s lymph 10°28 0:0018 0.018 Grav. 
aoe so 10°01 00019 0-019 Vol. 
ee 16700 3 00020 0020 “ 
(4) ee Se 10°03 | 0°0019 0°019 c 
peers Cir? 10°12 00019 0°019 ee 
(6) Pea 28) Sk 10°32 0°0022 0°021 Grav. 


ing the precipitated casein it still contained appreciable amounts 
of potassium. It was found preferable to evaporate weighed 
portions of milk to dryness, oxidize with concentrated nitric 
acid, again evaporate to dryness, and ignite gently until most 
of the or ganic matter was burnt off, finishing the ignition after 
moistening the residue with concentrated sulphuric acid. In 
the residues thus obtained the potassium was estimated gravi- 
metrically or volumetrically as in the previous work. 

The results obtained for potassium in two specimens of 
cow’s milk are given in Table III. 


TasieE III. 
Milk taken K.O found 
= aes — 
grm. germ. per cent Method 
I (1) Derg 2 as & 25°8 0°0413 0°16 Vol. 
(2)  agnae Peas 25°8 0°0432 Ook? = 
(3) 28 yey Sere 25°8 0°0428 0°17 Grav. 
05 eee 51°6 0°0833 0°16 Vol. 
1 3 ah Of (eee comes 25°% 0°0454 0°18 Be 
(2) a sae ENS ree 25-7 0°0457 0°18 ee 
(3) Fok, 3 ae pS ay 0°0451 0°18 Gravy. 
Summary. 


Where protein does not occur m animal fluids it was found 
most advantageous to oxidize the dried residue with a 9:1 


562 Drushel—Kstimation of Potassium in Animal Fluids. 


nitric-sulphurie acid mixture. In the presence of protein 
oxidation by bromine, or by nitric acid alone, finishing the 
ignition in the latter case with a little concentrated sulphuric 
acid was found more satisfactory. 

For the volumetric estimation the ignited residue was 
treated with a few drops of acetic acid and a little water. To 
this solution an excess of sodium cobalti-nitrite was added and 
the mixture evaporated nearly to dryness. The residue was 
cooled, treated with cold water, filtered on asbestos and well 
washed with a half saturated sodium chloride solution. The 
precipitate was oxidized by an excess of hot standard potas- 
slum permanganate, the solution bleached by an excess of 
standard oxalic acid, and titrated to color with permanganate. 

For the gravimetric controls the calcium, phosphoric acid 
and iron (in the case of the blood) were removed either before. 
or after the oxidation and ignition. The residue of sulphates 
was dissolved.in a little hydrochloric acid and water, and the 
potassium estimated as the chlorplatinate, taking care to wash 
the precipitate with alcohol, Gladding’s reagent and again 
with alcohol. 

Conclusions. 

The necessity of allowing the cobalti-nitrite mixture to stand 
from 12 to 20 hours to complete the precipitation, suggested 
by Gilbert, Adie and Wood, and others, is avoided by evapo- 
rating the mixture nearly to dryness. The removai of the 
cobalt from the precipitate before oxidation with permanga- 
nate is unnecessary, since the cobalt is reduced and not reoxi- 
dized in the titration process, and since with proper dilution 
its color does not interfere with the end point. 

For small amounts of potassium fairly accurate results are 
obtained by using the permanganate factor calculated from 
Adie and Wood’s formula for potassium cobalti-nitrite. Sutton 
has suggested that more accurate results are secured by obtain- 
ing a factor empirically from a pure potassium salt. All the 
results from this and previous papers were obtained, however, 
by using the theoretical factor calculated from the formula of 
Adie and Wood, their analyses of potassium sodium cobalti- 
nitrite having been verified by the analysis of a carefully 
prepared salt. 

The chief sources of error in the method appear to be in the 
slight solubility of the potassium sodium cobalti-nitrite, being 
one part in 25,000 to 30,000 parts of water at room temperature, 
and its tendency to inelude traces of sodium cobalti-nitrite. 
These sources of error tend in opposite directions, resulting 
usually in a positive error, which by proper washing of the 
precipitate may be kept within fair limits. 

The method requires less time and labor than the chlorplat- 
inate method, and is applicable in the presence of substances 
which form no insoluble cobaltinitrites and which neither 
oxidize oxalic acid nor reduce potassium permanganate. 


Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 563 


Art. LII.—TZhe Meso-Silurian oe of Me 
by Wu. F. Proury.* 


TE present article discusses briefly the lithological and 
faunal characteristics of the deposits in the state of Maryland 
lying between the massive Tuscarora (White Medina) sand- 
stone below and the Salina formation above. These deposits 
are approximately eight hundred feet in thickness and repre- 
sent the lower and middle portion of the Meso-Silurian series 
as shown in western New York. The lower portion corre- 
sponds to the pre-Rochester Silurian, the Clinton of common 
usage, while the upper portion is the approximate equivalent 
of the Rochester, or the lower division of the Niagara group 
of common usage. 

It is moreover probable that these deposits are equivalent 
to the typical Clinton of Hall exposed at Clinton, Oneida 
County, N. Y. The latter, according to both E. O. Ulricht 
of the U. 8. Geological Survey and to C. A. Hartnagelt of the 
New York Survey, contains in its upper portion a fauna equiv- 
alent to the Rochester or Lower Niagara fauna of western 
New York. It is very unfortunate that the fauna of the typ- 
ical Clinton should have gone so long unstudied, thus allowing 
at the present a double meaning of the term Clinton, as seen 
below. 

The Meso-Silurian deposits of western New York and the 
interior may be subdivided as follows : 

( 3. Guelph 
( B. Niagara 2. Lockport 
_ (1. Rochester 
Meso-Silurian ¢ 


| 
[ A. Clinton 


while the Meso-Silurian deposits of eastern New York, Penn- 
sylvania, Maryland, etc., may be subdivided as follows: 
( 2. Rochester of com- 
2 let Soe | ep ite | mon usage 
Meso-Silurian } A. Typical Sianon ‘Ce oe 
[ usage 
I shall not enter into a discussion of the nomenclature, but 
shall use the term Clinton in the restricted sense to include 
only the portion below the Rochester. 
In the study of the Maryland Meso-Silurian deposits all the 
important exposures in the state have been visited and at each 
* Published by permission of the Director of the Maryland Geological 


Survey. 
+ From letters of recent date. 


564 Wm. FL. Prouty—Meso-Silurian Deposits of Maryland. 


place careful measured sections and fossil collections have 
been.made. With the exception of the Ostracods and Bryo- 
zoa, the fossil study has been practically completed. In the 
pursuance of his work the author has had access to the collec- 
tions of the National Museum, the New York Museum of 
Natural History, the New York State Collection at Albany, 
and several smaller and private collections. He is also greatly 
indebted to Prof. Schuchert of Yale University, Dr. E. O. 
Ulrich of the U. 8. Geological Survey, Dr. C. K. Swartz of 
Johns Hopkins University, and others for assistance. He is 
further indebted to the Director of the Maryland Geological 
Survey for the privilege of publishing this article. 

Before turning to the present discussion of the Meso-Silurian 
in Maryland, let us make a brief historical review of what 
has already been done in this area and what have been and are 
' the views held concerning it. 

[fistorical Review.—Nearly fifty years ago Philip Tyson, 
the state agricultural chemist of Maryland, published* the 
first report of importance dealing with the geology of western 
Maryland. He touched but briefly upon the formations under. 
consideration, using terms, “the Clinton” for the pre-Rochester 
Meso-Silurian’ and ‘‘the Onondaga” for the remainder of the 
Meso-Silurian and the Cayngan. In 1874 Prof. James Hall 
of New York, who had worked in Maryland, especially in the 
Lower Helderberg, did not recognize the presence of Niagara. 
It appears that he later did, as he cites Sparifer crispus and 
Homeospira apriniformis from the “ Niagara” of Maryland. 

In 1893 a preliminary geological map + of the state showed 
the whole Meso-Silurian deposits under the name ‘“‘ Rockwood.”’ 
James D. Danat in 1895 recognized in Pennsylvania, immedi- 
ately north of Maryland, a commingling of Clinton and Niag- 
ara fossils in the upper Clinton beds, and states that there 
frequently occur some distance above the top Clinton iron-ore, 
a succession of thin limestones which in many places contain 
Niagara fossils. | 

The author of the Piedmont Folio§ discussed a part of the 
Maryland area, using the terms Rockwood-(Clinton or pre- 
Rochester Meso-Silurian) and Lewiston (later Meso-Silurian, 
Cayugan and Lower Helderberg).. There is here a preliminary 
discussion of the two formations as Rockwood and the lower 
part of the Lewiston. 

The first detailed lithological study, however, of the Meso- 

* Geological Map and Report, 1861. 

+ Map to accompany ‘‘ Maryland: Its Resources, Industries, and Insti- 
tutions.” G. H. Williams and W. B. Clark. 


+ Manual, 4th edition, 1895. 
§ Geol. Survey Atlas, Folio No. 28, 1896. 


Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 565 


Silurian of Maryland was made in 1900 by C. C. O’Harra.* 
He used the terms Clinton and Niagara, correlating the forma- 
tions in Maryland with those in western New York. 

It has long been known by all geologists working in the 
Appalachian districts that there is a marked stratigraphic 
change as one passes westward over the protaxis of these moun- 
tains. For the explanation of this fact the theory of a pro- 
found fault was suggested by some but accepted by few. Sir 
William Logan of the Canadian Survey, in 1866, suggested 
the possible existence of a narrow basin of deposition west of 
the protaxis to account for the stratigraphic break. 

It has also long been recognized that there exists a fau- 
nal difference in some of the deposits west of the protaxis 
in the Appalachians and in those west of the Allegany 
Mountains in New York and the interior. The explanation 
of this fact was little dwelt upon until recently, when E. O. 
Ulrich and Charles Schuchert, after careful investigation 
and faunal study, put forward a most admirably devel- 
oped theory} to account for the apparent condition. They 
conclude from paleontological evidence that there existed a 
barrier of great length, which separated from the interior sea 
a long and narrow body of water lymg in the Appalachian 
region, the “Cumberland basin,’ in which sediments were 
deposited bearing fauna more closely related to the east Canada 
and European deposits than to those of the interior sea; that 
the Atlantic crossed over the barrier forming the eastern side 
of this basin in about Beekmantown time, but was restrained 
by the western barrier of this basin from mingling with the 
‘interior sea, possibly from Clinton but certainly from Niagara 
time well into Oriskany time. The barrier forming the west- 
ern side of the Cumberland Basin extended, according to 
Ulrich and Schuchert, from the region of Cayuga Lake, N. Y., 
southward to west of Altoona, Pa., thence parallel to the trend 
of the Appalachian Mountains through central West Virginia 
into eastern Tennessee. In discussing the fauna of the Cum- 
berland Basin, Ulrich and Schuchert state that few species are 
identical with those of the interior sea, and that the earlier 
fauna recalls the Clinton, while it passes above into one which 
may be compared to the Niagara. 

Charles Schuchert, in a later publication,t speaking of the 
Maryland deposits which include the Clinton and Niagara, 
says that save Atrypa reticularis and Leptaena rhomboidalis 
all the species appear to be new. Further, he directs attention 
to the absence of such characteristic forms of the western or 

* The Geology of Allegany Co., Md.; Md. Geol. Survey Rept., pp. 
57-164, 1900. 

+ Paleozoic Seas and Barriers in Eastern North America. N. Y. State 


Mus. Bul. No. 52, 1902. 
¢ Lower Devonic and Ontario Formations of Maryland, 1903. 


566 Wm. F. Pro uty— Meso-Silurian Deposits of Maryland. 


Mississippian sea as Spirfer radiatus, Spirifer Niagarensis, 
Spirifer Crispus, Spirifer sulcatus, Pentamerus oblongus, 


Caryocrinus, and Hucalyptocrinus. Of 


these, Sperifer radi- 


atus and Spirifer crispus are now known to occur in the Cum- 


Sa NS SF 


Kies de 


Dotted areas are Meso-Silurian. Scale 1 in.=16 miles. 


Ma 
ERLAND 


Kay) CUMB 
Ww ty 
mM 
mf 
yt MY 
444 


nine. As would be expected from the 


berland Basin. - 

Mr. C. A. Hartna- 
gel of New York, in 
an article* in 1902, 
shows, however, that 
the western or Held- 
erbergian barrier was 
not continuously and 
completely effective 
from Clinton to Oris- 
kany time, since the 
mingling of Guelph 
and Cobleskill fauna 
evidence the crossing 
of the barrier during 
Cobleskill time. | 

Up to the present 
less than half a dozen 
species of fossils have 
been definitely de- 
scribed from the Mary- 
land, Clinton, and 
later Meso-Silurian. 

General Descrip- 
tion.— The outcrop of 
the Meso-Silurian 
rock in Maryland is 
limited entirely to the 
region of the Alle- 
ghany Ridges proper, 
in Washington and 
Allegany Counties. 
The area covered is 
about twenty-four 
square miles, of which 
the Clinton occupies 
fifteen and the Later 
Meso-Silurian about 
general Appalachian 


structure, the rocks under discussion flank anticlinal folds which 


* Preliminary Observations on the Cobleskill 
Rept. N. Y. State Paleont. for 1902, p. 1156. 


Limestone of New York. 


Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 567 


have a general trend N. 20°-30° E. There are six such folds 
exposing these strata in Maryland: three in Allegany County 
and three in Washington County (see map, fig. 1). The axes 
of the anticlines are formed by the very resistant “ Tuscarora”’ 
or ‘‘white Medina” sandstone. Nearly all the folds are un- 
symmetrical, giving a much narrower outcrop on the west than 
on the east side. 


GENERAL CHARACTER OF THE DEPOSITS. 
Clinton Formation. 


The rocks of this age in Maryland consist essentially of red- 
dish and olive to grayish and brown argillaceous shales which 
are slightly lighter in color and less fossiliferous toward the 
bottom. The exposed surfaces of this shale often show a deep 
searlet color. Thin sandstone bands occur at irregular inter- 
vals throughout nearly the whole formation and become more 
numerous toward the bottom, giving the formation the appear- 
ance of grading into the Tuscarora quartzite. These thin sand- 
stone bands were in general originally more calcareous than at 
present and are uniformly more fossiliferous than the shale in 
which they oceur. Toward the top of the formation limestone 
bands become numerous and replace the sandstone layers. They 
seldom exceed six inches in thickness, and in some localities 
are very fossilferous. Immediately overlymg the limestone- 
bearing shales throughout the region there occurs a quartzitic 
sandstone, of variable thickness, which in character resem- 
bles very closely the Tuscarora. This sandstone thickens 
markedly toward the east, increasing from ten feet in thick- 
ness near Cumberland to nearly seventy feet in some eastern 
exposures. In the top portion of this sandstone is found the 
so-called top Clinton iron-ore, usually not more than a foot in 
thickness and commonly of too lowa grade to work. In places, 
however, it is thicker and has been enriched so that in the 
past it has served as an ore and might at present locally be so 
called were it more accessible to the railroad. In this latter 
respect the top Clinton ore differs markedly from the so-called 
bottom Clinton ore which occurs throughout the Maryland 
area from one hundred and twenty to one hundred and sixty 
feet from the bottom of the formation and which, though it 
sometimes attains forty feet. in thickness, is not sufficiently 
high in iron to be valuable as an ore. This lower zvon sand- 
stone occurs in two beds separated by from six inches to six 
feet of olive shale. Both the bottom and top “ore” bodies 
contain numerous though very poorly preserved fossils. 

The olive shales and thin crystalline limestone bands imme- 


568 Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 


diately above the top Clinton iron-ore sandstone contain a 
greater percentage of Rochester fossils than of those of the 
pre-Rochester Meso-Silurian, and consequently it would appear 
that the lower limit of the Rochester should be drawn at the 
top of the heavy sandstone laver. The thickness of the Clin- 
ton does not vary far from five hundred and fifty feet. 


The Later Meso-Silurian (fochester). 


The rocks of the Later Meso-Silurian formation, as herein 
discussed, include those lying between the heavy band of sand- 
stone bearing the top Clinton iron-ore and the bed of disinte- 
grated yellow rock full of Leperditia which marks the base of 
the overlying Cayugan, and are composed for the most part 
of thin-bedded limestones with shale partings. For a short 
distance above the bottom and for a greater thickness near the 
top the shales increase and preponderate over the limestone. 
The lowest limestone layers are grayish blue in color and, 
together with the shales which immediately overlie the Clinton — 
sandstone layer, are very fossiliferous. The upper limestones 
are uniformly of a darker color and more compact, sometimes 
occurring in more or less lenticular beds with thin shale part- 
ings. In general the middle limestones and shales contain few 
fossils, with the:exception of Ostracods and a few Favosites 
and Orthoceras. Toward the top, however, the brachiopod 
life begins again to abound and some beds are very fossilif- 
erous. The upper shales are usually darker it color than those 
below and often become arenaceous, bearing thin sandstone 
lenses, while the top of the formation is often formed by a bed 
of sandstone of variable thickness which is often very ferru- 
ginous. These upper dark shales usually carry a great number 
of Ostracods and poorly preserved Bryozoa. 

Going toward the east, one generally finds that both the 
lower shales and the upper ferruginous sandstone layers 
inerease in thickness. The thickness of the formation is in 
general not far from three hundred feet. At Pinto, where the 
most accurate measurements were made, though they are not 
entirely satisfactory because of some faulting, these rocks show 
a thickness of two hundred and eighty-eight feet. 


General Lithological Relations. 


It is concluded from.a comparative study of the different 
exposures in the state that during the deposition of these 
sediments there existed a shore line not far to the east, and a 
gradual deepening of the waters toward the west as far as the 
section exposed at Pinto (see section, fig. 2and map, fig.1). The 


Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 569 


main facts supporting this conclusion are: the top Clinton 
sandstone increases gradually in thickness from seven feet at 
Pinto to some sixty-five or seventy feet in the eastern exposures ; 
the bottom Rochester shales increase in thickness and the 
bottom limestones consequently decrease in thickness in passing 
from west to east; the top Rochester sandstone, like the top 
Clinton sandstone, thickens from eight feet at Pinto to some 
fifty feet or more in the eastern exposures. If we assume then 


Hig: 
i 2 3 4 5 6 7 8 


Rochester 


| 
2 

A 

5 

1. Pinto Section. 4. Cumberland Section. 7. Great Cacapon Section. 
2. Cedar Cliff ‘‘ 5. Six-mile-house ‘‘ 8. Keefers Mt. ee 

3. Rose Hill *‘ 6. Flintstone le 


that the Maryland Meso-Silurian deposits were laid down in a 
narrow basin of deposition, then Pinto must be east of the 
central axis of the basin or else the western shore line of this 
narrow sea must have been much lower than the eastern land 
was. Itis not improbable that both these conditions were true. 


Fossil Zones. 


In Clinton.— 

The Clinton formation, so far as studied, has not shown any 
well-marked continuous fossil zones. Portions of the strata 
are much more fossiliferous, however, than others, and the 
formation as a whole is naturally divisible into four parts: 


Am. Jour. Sc1.—FourtH Series, Vot. XXVI, No. 156.—DrEcrempBer, 1908. 
40 


570 


FIG. 3; 


| 


| 
i 
I 


| 
| 


HI 
| 

HAN 
Hy 


f) 


| 
| 


i 
Hl 


; 
iF 
| 


HATE 
il 
itil 


| 
| 


| 
| 


Ei 
HE 


| 
| 


SUNTAN 
nit 
A 


| 
| 
| 


| 
| 


| 
i 
I 


ij 


lI 
\\-| 


| 
| 
| 


ss 


i 
i 
| 


Tusearora 


Camarotoechia obtusiplicata Zone 


Camarotoechia  sf.nov. Lone 


Nucleospira ae Zone 
Dalmanites limulurus Zone 


Upher Fossiligerous Division 


Middle Barren Division 


LowerFossiliterous Division 


Lower Barren Division 


Wn. F. Prouty—Meso-Silurian Deposits of Maryland. 


(1) a lower relatively 
barren division includ- 
ing the shales and 
sandstones up to with- 
in some thirty feet of 
the lower “iron ore,” 
which bears locally at 
its base a few plant 
remains, the ostracod 
Berichia lata and the 
brachiopod Anoplo- 
theca hemispherica ; 
(2) a lower fossilifer- 
ous division, ncluding 
the remaining shales 
below the bottom 
‘iron ore,’ the ore 
bed and some fifty to 
eighty feet of the over- 
lying shales and sand- 
stones; (3) a middle 
barren division, in- 
cluding some two hun- 
dred feet of relatively 
barren shales and sand- 


stones; and (4) an 


upper fossiliferous 
division, including 
about one hundred 
feet of shales and in- 
terbedded sandstones, 
replaced by thin-bed- 
ded limestone toward 
the top, about which 
OCCUTrS tite. wre 
shightly fossiliferous 
top Clinton sandstone 
(see sect. fig. 3). 

Of the two fossil- 
iferous divisions, the 
lower is characterized 
by a large number of 
tentaculites and ostra- 
cods and two species 
of trilobites. The 
upper fossiliferous 


Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 571 


division, on the other hand, is characterized by its branchi- 
opod fauna. 
The forms noted in the two fossiliferous divisions are as 
follows: 
From the lower fossiliferous division: 
Buthotrephis gracilis var. intermedia Hall 
* Anoplotheca hemispherica (Sowerby) 
Stropheodonta corrugata (Conrad) 
+ Tentaculites sp. 
Clidophorus sp. 
* Calymene blumenbachit 
* Calymene sp. nov. 
* Ostracods 
From upper fossiliferous division : 
t Atrypa reticularis (Linnaeus) 
* Leptaena rhomboidalis (Wilckens) 
Camarotoechia neglecta Hall 
* Chonetes cornutus (Hall) 
* Chonetes novascoticus (Hall) 
* Chonetes tenuistriatus Hall 
Spirifer radiatus (Sowerby) 
Bucanella trilobata (Conrad) 
Calymene clintoni (Vanuxem) 


In Upper Meso-Silurian.— 


While the Clinton fossils seem to have a rather extended 
range vertically and a more or less local distribution, making 
a close zonal study of this formation seemingly impracticable, 
the overlymg Meso-Silurian may be divided into five portions, 
three of which are well-marked faunal zones. Immediately 
‘overlying the top Clinton sandstone and extending vertically 
sometimes 30 feet, though usually more restricted, is a very 
prolific faunule, marking a zone called from one of its most 
widespread and characteristic fossils, the Dalmanites limulurus 
zone. ‘This zone includes more than one-half of the species | 
described from the whole Meso-Silurian series of Maryland. 
At Cumberland, where this zone was most studied, the foilow- 
ing species were observed : 


Fauna of the Dalmanites limulurus Zone. 


Anoplotheca hemispherica (Sowerby) 
* Atrypa reticularis (Linnaeus) 
Camarotoechia neglecta Hall 
Dalmanella elegantula (Dalman) 

+ Dalmanella elegantula var. nov. 

* Leptaena rhomboidalis (Wilckens) 
Reticularis bicostata var. nov. 


* Abundant. + Very abundant. 


572 Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 


* Rhipidomella subcirculus (Simpson) 
Rhipidomella hybrida (Sowerby) 

+t Rhynchonella (tennesseensis) ? Roemer 
Schuchertella supblana (Conrad) 
Schuchertella tenuis Hall 

Spirifer crispus (Hisinger) 
Stropheodonta corrugata (Conrad) 
Stropheodonta corrugata var. pleuristriata (Foerste) 
Stropheodonta sp. nov. 

Stropheodonta sp. nov. 

Ctenodonta sp. nov. 

Pterinea emacerata (Conrad) 

Bucanella trilobata (Conrad) 

Conularia sp. 

* Diaphorostoma niagarensis Hall 
Platycerus sp. nov. 

Platyceras niagarense Hall 

Trochoceras sp. 

+t Dalmanites limulurus (Green) 

* Homalonotus delphinocephalus (Green) 
Cornulites sp. nov. 


Immediately overlying the Dalmanites limulurus zone there 
is a fossiliferous horizon of some 8 to 15 feet in width, which 
contains great numbers of Wucleospira pisiformis and some- 
times a few Schuchertella sp. nov. This Wucleospira pisi- 
formis zone, which occurs in the calcareous shale and limestone 
layers, is overlain by some 150 feet of limestone and shales in 
which the fossils are fewer and more scattered. 

This latter division has given us the following species : 

Buthotrephis gracilis var. intermedia Wall 

* Favosites niagarensis Hall 
Jamarotoechia neglecta Hall 

* Homeospira evax var. nov. 

Lingula sp. nov. 

Orbiculoidea sp. nov. 

Clidophorus sp. nov. 

Hormatoma sp. nov. 

+ Hormatoma sp. nov. 


Near the top of the formation and usually between 50 and 
80 feet below the “disintegrated yellow rock” of the Salina 
(the Niagara-Salina line) there occurs a band some 30 feet in 
thickness which is here called the Camarotoechia sp. nov. zone. 
It has yielded the following species: 

+ Camarotoechia sp. nov. 
+t Camarotoechia obtusiplicata Hall 
Camarotoechia neglecta Hall 
Lingula lamellata Hall 
Spirifer sp. nov. 
Clidophorus sp. nov. 
Cuneamra sp. nov. 
* Abundant. + Very abundant. 


Wm. FF. Prouty—Meso-Silurian Deposits of Maryland. 573 


Above the preceding there is a zone two feet in thickness in 
which occur great: numbers of Camarotoechia obtusiplicata 
‘mingled with C. sp. nov. and Cuneamra sp. nov. 

The uppermost 50 feet of the Meso-Silurian rocks are in 
general largely shale and sandstone. They contain very abun- 
dant Ostracods and poorly-preserved Bryozoa and, in addition, 
so far as studied, only two fossils : 

Homeospira evax var. nov. 
Ctenodonta sp. nov. 


Table Showing Number, General Relation and Affinities of 
Maryland Meso-Silurian Fossils. 


Number of forms studied: 


Number of species and varieties studied -.------- 56 
Number of species previously described -...----- 32 
INumiber of mew species J... 222-22 25 Lopes 20 
Number of new Varieties 2.22.25... 35-4-Len be 4 
Percentage of new forms 
Petcentacte ol new species). 2. 222222 bee el 35°7 
Pereentace of new varieties: 22.4. 22222 22--55522- yet 
Percentage of new species and new varieties -- ---- 42°8 
Occurrence elsewhere : . 
Number of species occurring in Arisaig ----------- 10 
x z: <s English Silurian -.-. 8 
“ os Anticestie. 222 2 5 
et sf a Ohie Clinton 222i 
66 6c 5 6c Niagara cacti 15 
rs 2 ee Panganiban ee Fe oe Sens 16 
6c 66 66 6c Clinton __._. 1 
e ct sf New York Rochester. 12 
Se s ee New York Lockport.. 3 
s . Rochester and Lockport 2 
Ey eo ss Niagara and not refer- 
red to either Rochester or Lockport 3 


One-fourth (8) of all the previously described species occur 
in the European deposits, of which species seven are also found 
in the middle United States. 

Number of different species cited from either Anti- 
costi, Arisaig or English deposits __.-._-- ---- 18 
Number of these cited from either Indiana or Ohio 12 

From a study of the foregoing fossil lists and the above 
table one is impressed with the marked faunal difference 
between the Meso-Silurian deposits of Maryland and those of 
Western New York and the interior. The fact that there are 
so many new species (42 per cent of all studied) argues very 
strongly in favor of the supposition that the Maryland Meso- 
Silurian deposits were laid down in a sea distinct from that of 
Western New York and the interior. This argument is fur- 
ther strengthened by the fact that several of the most promi- 
nent species of the interior Meso-Silurian sea are not repre- 


574 Wm. F. Prouty—Meso-Silurian Deposits of Maryland. 


sented in Maryland. That there were short periods, however, 
when the low barrier separating this Cumberland Gulf from 
the interior epicontinental sea was ineffective, is shown by a 
few zones in the Maryland Meso-Silurian which have a prolific 
development of certain of the more important Western New 
York forms, as for instance the Dalmanites limulurus zone, 
the JV: ucleospira pisiformis zone and the Camarotoechia obtu- 
siplicata zone. (See fig. 3.) 

The great coral development of the western upper Niagara 
is entirely lacking in the Maryland deposits. In fact there 
are practically no fossils which belong distinctively to the 
Lockport or Guelph formation, and it is probable that during 
the greater part of these two periods there was little or no 
sedimentation in the Maryland area. The Meso-Silurian sea 
may have continued to exist in the Cumberland Gulf in early 
Lockport time, but if so, seemingly for a short period only. 

It is further interesting to note that one fourth of all the 
previously described forms are of world-wide distribution ; 
that six of the old forms are characteristic of the deposits of 
Anticosti, Arisaig or the English Silurian, while fourteen are 
characteristic of the western interior. This last result is, how- 
ever, of little value in showing the relative ease of communica- 
tion between the Cumberland basin and the epicontinental sea 
to the west and the Canadian deposits to the north and east, 
since the Canadian deposits have not been studied as well as 
have those of the interior United States. 


Summary. 


The Meso-Silurian deposits of Maryland, lying between the 
Tuscarora and the Salina formation, are about 800’ in thickness 
and are composed for the most part of shales and thin-bedded 
sandstones below and of shales and limestone above. This 
series can be divided into two formations, corresponding in 
time approximately to the Clinton, accorded to the common 
usage, and the Rochester of New York. They are, moreover, 
taken together, the probable equivalent of Hall’s typical Clin- 
ton as represented at Clinton, Oneida Co., N. Y. 

These Meso-Silurian rocks outcrop in the western part of 
Maryland in Allegany and Washington Counties in six anticlinal 
folds with typical Appalachian structure. The thickening of 
the coarser sediments from the western to the eastern exposures 
indicate the proximity of a shore line toward the east. That a 
shore line or barrier existed not far to the west of the exposed 
Maryland Meso-Silurian deposits is not evidenced by a lithogi- 
cal study, but is sufficiently indicated by the fossil study. This 
barrier must, however, have been low and at periods ineffective, 
especially during Rochester time, when, to a greater extent 
than in the Clinton, well marked fossil zones appear, making 
a prolific development of some of the more important species 
of western New York. 


Chemistry and Physics. 575 


SCAN EEEFICOERN TE LEIGEN CH: 


I. Cuemistry AND Puysics. 


1. Rate of Production of Helium from Radium.—Sir James 
Dewar having succeeded, by the use of the radiometer, in 
detecting a gas pressure of the fifty-millionth of an atmosphere, 
and having definitely detected by this means the helium pro- 
duced in a few hours from about ten milligrams of radium 
bromide, has undertaken the direct measurement of the helium 
produced by radium. For this purpose he employed 70 mg. of 
radium bromide belonging to the Royal Society, which had been 
used by Dr. Thorpe in his recent determination of the atomic 
weight of radium. The apparatus employed for measuring the 
helium consisted of a McCleod gauge in which no rubber joints 
were used, together with ingenious arrangements for exhausting 
the apparatus. Any traces of adventitious gases were absorbed 
by an attached bulb containing charcoal and cooled in liquid air. 
In one instance the pressure registered at the start of the experi- 
ment was 0:000044 mm. The radium salt was occasionally heated 
and the pressure of the helium was determined from time to time. 
A steadily maintained helium increment was obtained of approx- 
imately 0°37 cu. mm. per gram of radium per day. This result 
agrees very closely with Rutherford’s theoretical calculation, 
which gives about 0°3 cubic millimeters per day.—Advance 
sheets from author. Hin Ee We 

2. Radium in Tufa Deposits.—ScuLtunpt has examined a 
number of these deposits from Hot Springs, Ark., and finds that 
the amount of radium in them varies to a remarkable degree. 
Some of the samples gave low results corresponding to 0°56, 0°72, 
0°73, 1°18, 2°62 and 2°85 x 10-" g. of radium per gram of tufa, 
while other samples gave such results as 26°7, 36°83, 156°0, 227, 
1322 and 1900 X 10°" g. of radium. These deposits appear to 
be derived from springs of similar character, and differences in 
the physical character of the material gave no clue to their 
radium contents. Boltwood had previously found considerable 
variations in the radium in the water from different springs in 
this locality, and it appears from a limited correlation of the 
results that no correspondence exists between the radium contents 
of the waters and of the tufas deposited by them.— Chem. News, 
xevill, 199. HPESW. 

3. A Compound of Cobalt with Carbon Monoxide.—Monp, 
Hirtz and Cowap have succeeded in preparing cobalt carbonyl, 
Co(CO),, which corresponds in composition to the remarkable 
nickel compound described by Mond and other co-workers in 
1890. ‘The cobalt compound was prepared by taking advantage 
of a method of Dewar for facilitating the formation of nickel 


576 Scientific Intelligence. 


carbonyl, which consists in using carbon monoxide under press- 
ure at a correspondingly higher temperature. <A pressure of 100 
atmospheres was used for the carbon monoxide, and under this 
condition a combination with finely divided metallic cobalt took 
place between 150 and 200° C. The cobalt carbonyl is a very vola- 
tile substance which condenses in the form of large orange crystals 
when the vapor is cooled by ice. The compound is very unstable, 
melting with decomposition at about 42 to 46° C. It is gradually 
decomposed in air, yielding a deep violet substance which has 
not yet been investigated.— Chem. News, xcvili, 165. 4H. L. w. 

4. Cyanide Processes ; by KH. B. Witson. 12mo, pp. 249. New 
York, 1908 (John Wiley & Sons).—This is the fourth edition, 
revised and enlarged, of a well-known treatise. Owing to the 
recent improvements in cyanide practice, especially in the treat- 
ment of slimes, the author has added a chapter giving the latest 
methods for treating such material. The book, as has been the 
case with previous editions, deals with the theories and facts con- 
nected with the processes, without giving details of the construc- 
tion of the plant and machinery. H. LL. W. 

5. Magnetic Rotation of Electric Discharge.—Professor D, N. 
Ma.tix has studied the old experiment of De La Rive, which con- 
sists in causing the rotation of an electrified discharge around 
the pole of a magnet, and classifies three stages : showery, band, 
and glow. ‘The discharge rotates under the influence of the mag- 
netic field, only when it is in the form of a band over a range of 
pressure depending on the nature of the gas or vapor in the tube © 
through which the discharge passes, the E. M. F. producing the 
discharge and the distance between the electrodes. In air, and 
probably in all gases, the angular velocity of rotation is propor- 
tional to the E. M. F. producing the discharge, and increases as 
the spark length decreases. Professor Mallik also analyzes the 

conditions of pressure and temperature.— Phil. Mag., i i: 
pp. 5381-550. 

6. A Directive System of Wireless Telegraphy.—k. Baio 
and A. Tost describe such a system which depends upon a method 
of orienting the sending coils of a transformer with respect to 
the antenne. They give a test of their method, carried out 
between the stations of Dieppe and Havre. On turning what they 
term their radiogiometer in the direction of Havre, reception of 
messages was effected: On turning the pointer of this instru- 
ment to 180° this reception ceased entirely. The authors point 
out the strategical advantage of their system.—Phil. Mag., Oct., 
1908, pp. 638-657. Joa 

7. Positive Rays.—Professor J. J. Tuomson, in an extended 
article on this subject, reviews and corroborates the results of 
Villard (Comptes Rendus, cxliii, p. 673, 1906) on what is termed 
retrograde rays: that is, positive rays which proceed from the 
cathode and travel against the positive rays, proceeding from the _ 
anode. Professor Thomson also gives a theory of the method by 
means of which these retrograde rays obtain their velocity. The 


Chemistry and Physics. 577 


paper also contains a discussion of the nature of positive ions in 
different gases, when the ionization has settled into a steady 
state.— Phil. Mag., Oct., 1908, pp. 657-691. Jats 

8. Amount of Radium Hmanation in the Atmosphere near 
the Earth’s Surface.—Experiments on this subject have been car- 
ried out by Professor Eve at McGill University, Montreal, in 
a room fifty feet above the ground. ‘The outside air was 
drawn through cotton wool; then through three glass tubes con- 
taining cocoanui-shell charcoal. The air currents were continued 
for 2°7 days, at a speed of 6°7 cm*/sec. The tubes were then 
heated over Bunsen burners, so that the gases absorbed by the 
charcoal were expelled and collected over water and then exam- 
ined in the usual way, by means of an electroscope. It was 
found that the amount of radium which would be in equilibrium 
with the average amount of radium emanation in a cubic meter 
of air at Montreal measured at intervals 1907-8 is 60107" gram. 
This amount varied with cyclonic and anticyclonic conditions— 
but not appreciably from summer to winter.—Phil. Mag., Oct., 
1908, pp. 622-632. J.T. 

9. Absorption of Réntgen Rays.—Dr. Adams, working in the 
Jefferson Physical Laboratory, measured the absorption of these 
rays through various substances (this Journal, xxiii, Feb., 1907; 
also Proc. Am. Acad., xlii, No. 26). W. Sxrrz, in a preliminary 
paper, undertakes the same subject with the modification of using 
an aluminium window in the X-ray tube, to diminish as much as 
possible the sifting of the rays due to glass walls.—Ann. der 
Physik., No. 12, 1908, pp. 301-310. J.T. 

10. The Zeeman Effect in Solar Vortices.—The announcement 
of the discovery of this effect by Professor Grorcr A. Hate of 
Mt. Wilson Observatory has led to interesting discussions in 
Nature, Oct. 8 and Oct. 29, 1908. Jae: 

11. The Study of Stellar Evolution, an Account of some Recent 
Methods of Astrophysical Research ; by Grorar E. Harz. Pp. 
X1+ 252, with 104 plates. Chicago, 1908. Decennial Publications 
of the University of Chicago, Second Series, Vol. X.—The study 
of solar physics is a territory which resembles Central Africa,— 
many men have visited it and have picked up treasures here and 
there, but almost no systematic attempt has been made until the 
last few years to unravel its mysteries and to introduce order into 
the chaos of isolated facts and theories which have-been gathered 
in the general store of knowledge. As is generally known, Pro- 
fessor Hale has embarked on such a venture at Kenwood, at the 
Yerkes Observatory, and for the last three years at Mount Wilson 
under the auspices of the Carnegie Institution. With a multi- 
tude of problems under investigation, it is too early yet to expect 
very extensive results : the facts have still to be obtained. 

The volume under review may be classed as a sort of travel- 
ler’s guide, showing the roads which have already been opened, 
the methods used for continuing the exploration and the theories 
which indicate directions for future work. Its plan is best de- 


578 Seientifie Intelligence. 


scribed in the author’s own words: “TI finally adopted the plan 
of describing a connected series of investigations, laying special. 
stress on the observational methods employed, in the hope of 
explaining clearly how the problem of stellar evolution is 
studied. . . . The various researches described are chosen 
rather arbitrarily, in some cases‘-with more regard for my per- 
sonal acquaintance with the facts than because of their intrinsic 
importance.” 

While the main problem is that given in the title, the greater 
part of Professor Hale’s latest book has been directed towards the 
sun. He has shown not a little ingenuity in devising and con- 
structing instruments for the observation of a body which gives 
us so much heat that accurate work is seriously interfered with 
by the distortion of the lenses and mirrors employed. These 
devices, old and new, are described in nearly half of the printed 
matter of the volume with the reasons which have led to their 
adoption. Interspersed are chapters on the hypotheses which it 
is desired to test. The author has also considered those who 
have only a general acquaintance with scientific methods, and he 
outlines briefly the main principles of his subject,—spectrum anal- 
ysis, evolution of a star, the construction of a teleseope, and so on. 

In such a volume, criticism of details is unnecessary especially 
when so many of the questions at issue are still sub judice. It is 
to be recommended to those who wish to know the facts and 
problems sct forth in an attractive manner; parts of it will 
appeal to the trained student desiring a brief account of the latest 
developments; and perhaps more than all, the suggestiveness 
- which characterizes Professor Hale’s work will be welcome to 
those who are looking for problems to solve. ‘To mention only 
a single instance of the latter, we have yet to find out how to 
make a quantitative estimation of time changes on the solar sur- 
face with some approach to accuracy. 

About half the thickness of the volume is taken up with excel- 
lent photographs, and the somewhat rambling order in which the 
various subjects are treated will not be found an objection if full 
use is made of the index. The latter would have been more con- 
veniently placed at the end instead of the middle just before the 
plates, which are placed together in the second half of the book. 

ERNEST W. BROWN. 

12. Die Korpuskulartheorie der Materie; von Dr. J. J. THom- 
son, Autorisierte Ubersetzung von G. SreperT. Pp. viit+166. 
Braunschweig, 1908 (F. Vieweg & Sohn).—This is the German: 
translation of Professor Thomson’s latest book, which is an 
amplification of a course of lectures given in 1906 at the Royal 
Institution. It is similar in character to the author’s Silliman 
Lectures, “ Electricity and Matter,” delivered at New Haven in 
1903, and is essentially a sequel to them; the rapid progress in 
the development of the electrical theory of matter is strikingly 
illustrated. by a comparison of the two books. The first three 
chapters give a-brief account of the properties of the electron or 


Chemistry and Physics. 579 


corpuscle as determined experimentally and as deduced from 
electrical theory. The fourth chapter is concerned with that 
theory of metallic conduction which is based upon the assumption 
that the current is carried by free electrons. Although this 
theory is very successful in explaining most of the facts of metal- 
lic conduction, there are difficulties in connection with it which 
have led Professor Thomson to bring forward another theory, 
not quite so simple and perspicuous as the first, but free from 
some of its troubles; this theory is the subject of the fifth 
chapter. The sixth chapter gives an account of the author’s 
remarkable speculations with regard to the structure of the atom, 
in which it is shown that a purely electrical model can account 
for many of the chemical properties of atoms and in particular 
for the valence relations of the periodic system. ‘The seventh 
and final chapter deals with the considerations which have 
recently led the author to reduce his estimate of the number of 
corpuscles in the atom from many thousands to a number 
approximately equal to the atomic weight ; and the chapter closes 
with an ingenious attempt to account for the mass of the atom | 
in terms of the ether, but on quite different lines from the electro- 
dynamic explanation of the mass of the electron. H. A. B. 
13. Magneto- und Electro- Optik ; von Dr. WaLpEMAR VoiIer. 
Pp. xix+396. Leipzig, 1908 (b. G. Teubner).—The effects pro- 
duced by magnetic and electric fields upon the optical properties 
of bodies have been recognized as of great importance to the 
theory of the ether, ever since the original discovery of the - 
Faraday Effect. They have, however, proved very difficult to 
deal with either experimentally or mathematically, and not very 
much real progress was made until the discovery of the Zeeman 
Effect in 1896. This led to a great number of very interesting 
and significant experimental investigations ; and the application 
of the electrical theory of light to these observations has resulted 
in a very important body of theoretical knowledge which is 
not yet as familiarly known by most physicists as it should be. 
The present book by Professor Voigt, to whom we owe many 
important contributions to the mathematical side of this subject, 
will enable us to acquire this knowledge far more easily and 
satisfactorily than has been possible hitherto. Successive chap- 
ters deal with the Faraday Effect, the Zeeman Effect, the 
connection between the two, the effects observed in absorbing 
crystals by Jean Becquerel, and the two Kerr Effects. Experi- 
mental methods and results are described and illustrated by 
excellent reproductions of photographic spectra ; and the theory 
of these phenomena is developed to a greater extent, probably, 
than it has reached in the hands of any other writer. Some parts 
of the book are unquestionably difficult, but the subject of which 
it treats is not an easy one. H. A. B. 
14. The Evolution of Forces ; by Dr. Gustave Le Bon. Pp. 
xv+388. New York,1908 (D. ‘Appleton & Co. The International 
Scientific Series).—The author of the present work is well known 


580 Scientific Intelligence. 


as one of those workers in the fields of science who are unappre- 
ciated by their contemporaries, and who labor under the delusion 
that a conspiracy against them exists among the representatives of 
“official science.” An account is given of his theories and dis- 
coveries and the way in which they have been first neglected by 
others and later appropriated without his receiving credit. The 
book belongs to a class which is not unknown in the history of 
science. H. A. B. 
15. Hxperimental Electricity ; by G. F. C. Srarte. Pp. 
xvi+183. Cambridge, 1908 (University Press).—Mr. Searle’s 
unusual ability as a teacher of laboratory physies has long been 
recognized by those who have known of his work at Cambridge, 
or who have used the simple and accurate apparatus which 
he has designed. A series of laboratory manuals from his pen 
will undoubtedly be of service to teachers, and one is glad to 
learn from the preface that the present volume is to be followed 
shortly by another on Experimental Optics, and that volumes 
are planned, to deal with Mechanics, Electricity and Magnetism, 
and Heat and Sound. Hi. Ags 
16. The New Physics and its Evolution; by Lucten Poiy- 
CARH. Pp. xv+344. New York, 1908 (D. Appleton & Co. 
International Scientific Series).— This is an unusually good 
presentation of the recent progress in physics, and of the con- 
nection between modern theories and those of an earlier date. 
Although it is necessarily much condensed, it betrays few of the 
‘ordinary faults of condensation ; one paragraph follows another 
smoothly and logically without appearance of haste, and with the 
clearness that is characteristic of French writers. The knowledge 
of the author is obviously very extensive and nearly always 
accurate, and his appreciation of historical perspective is admir- 
able. The translation, however, is not above criticism. French 
phrases are often translated literally with amusing results, as on 
p- 192, where the feststrahlen of Rubens and Nichols are spoken 
of as “the waves which remain.” The notes by the editor of the 
English version are by no means up to the standard of the text. 
They are sometimes entirely wrong, as on pages 24 and 178; 
others give a quite erroneous impression as to the significance of 
the facts stated, as on pp. 172 and 311. These are, however, 
small defects in a very good book, and the author is evidently not 
responsible for them. H. A.B: 
17. The Principles of Mechanics ; by HENRY CrEw. Pp.x+295, 
with 110 figures. New York, 1908 (Longmans, Green & Co.).— 
This text-book is especially intended for students of physics and 
engineering, who have had a first-year course in physics and in the 
elements of the calculus. Like Professor Crew’s other text-books, 
it is admirably adapted to the use for which it is designed. It is 
simple, straightforward and logical, but without making a fetich 
of logic; and the student is kept in close touch with the realities 
of the laboratory and of ordinary life. The constant use of 
the useful analogy between problems of translation and of 


Geology and Mineralogy. 581 


rotation is a conspicuous feature of the book and will earn the 
approval of every experienced teacher. It may be a question 
whether it is not preferable to allow the student to gain first some 
idea of the dynamics of a particle, and to build upon this the 
dynamics of rigid bodies, instead of introducing them side-by-side 
as is done in this book and afterward developing their relations. 
Some teachers also will regret that the use of the principle of 
energy is so long delayed. These are, after all, questions of 
taste and not very important. Taken as a whole, the book is so 
good and so well suited to its purpose, that one may venture to 
predict for it a very considerable and well-deserved popularity. 
H. A. B. 


Il. GEOLOGY AND MINERALOGY. 


1. West Virginia Geological Survey. Volume II (a). Sup- 
plementary Coal Report; by I. C. Wuire, State Geologist. Pp. 
xiv, 720, with map in pocket. Morgantown, 1908.—In 1903 
the second volume of the West Virginia Geological Survey was 
published, giving an account of the coals of the northern part of 
the state, with also notes in regard to those of the southwestern 
portion. The present volume, IIa, discusses in all fulness of 
detail the Great Kanawha and New River coal fields, and those 
lying between them and the Kentucky line. The two volumes 
together, therefore, present an exhaustive account of the resources 
of the state in respect to this important industry. It may be 
noted that in 1907 some 48,000,000 short tons were produced, and 
the increase in rate of production at present averages nearly 
4,000,000 tons per year. A careful survey of the entire state 
leads to the conclusion that it may be expected to yield somewhere 
between fifty and sixty billion short tons of commercial coal, and 
about one-third as much more of impure and bony coal available 
for the gas engine. Most of the coal now marketed ranks high 
in calorific valne, and some of it is not exceeded by that of any 
other bituminous coal fields in the world. 

A large map of the state on the scale of seven miles to the 
inch has been distributed with this volume. It shows the distri- 
bution of the several coal formations and also the areas of oil, 
gas and limestone, with the principal anticlinal lines. 

2. Florida State Geological Survey, E. H. Serxuarps, State 
Geologist. First Annual Report 1907-8. Pp. 114, with 6 plates. 
Bulletin No.1. A Preliminary Report of the Underground Water 
Supply of Centrai Florida. Pp. 103, with 6 plates and 6 figures. 
Tallahassee, 1908 (Capital Publishing Co.).—The first’ annual 
report of the Geological Survey of Florida contains the adminis- 
trative report for 1907-8, by the state geologist, Prof. E. H. 
Sellards, with a sketch of the geology of the state. An account 
is also given of the mineral industries, chief of which is the phos- 


582 Scientific Intelligence. 


phate mining, the annual value of which now exceeds $6,000,000. 
Since the beginning of active mining in 1888, to the end of 1907, 
some 12,000,000 tons, valued at $48,000,000, have been taken 
from the Florida phosphate fields. There is also included a bibli- 
ography of Florida geology. 

Bulletin No. 1 discusses the underground water supply of the 
central portion of the state. The facts are interesting, as the con- 
ditions are peculiar in various directions. The large annual rain- 
fall taken in by the limestone rocks yields springs notable 
for their number and their unusual size. The basin of Silver 
Spring, for example, has a depth of 30 to 36 feet, and the total 
flow from several vents is not less than 369,000 gallons per minute, 
It is shown that the springs doubtless receive their water supply 
from the rainfall of the immediately surrounding country. There 
are two principal areas of artesian wells ; one on the east coast, 
and the other on the southern Gulf coast. The conditions in 
central Florida are not favorable for flowing wells. 

This bulletin will be of great value to the people of the state, ~ 
and to geologists in general it is interesting on account of the 
descriptions of the underground water supplies in cavernous 
limestone. The State Geologist reports that the Survey work 
will be carried on particularly on economic lines, but that maps. 
are also under preparation and arrangements have been made 
with the United States Geological Survey for a joint study of 
the larger field. problems. He is to be congratulated on the 
character of his first year’s work. H. E. G. 

3. Wisconsin Geological and Natural History Survey; kK. 
A. Brrex, Director. Bulletin No. XX. Economics Series, No. 13. 
The Water Powers of Wisconsin; by Lreonarp 8. Smita. Pp. 
Xvill, 352, with 54 plates and 17 figures. Madison, 1908.—The 
state of Wisconsin is unusually rich in its water power resources; 
not more than half a dozen other states in the country being so 
well situated. As at present developed it is estimated that the 
water power approximates 130,000 horse power; this probably 
represents a small proportion only of the total power available, 
This is of particular importance to the state, since it is relatively 
distant from coal supply. In 1905 the legislature appropriated 
$2,500 for a survey of the water powers and a report on them, 
and to this work the U. 8S. Geological Survey has contributed a 
like sum, in addition to having expended since 1902 a large 
amount for daily measarement of river flow. This bulletin pre- 

sents in detail the information thus far accumulated, and the data 
given will be of great value to those immediately concerned. 

4. The Geological Survey of Cape of Good Hope; Twelfth 
Annual Report, 1907, including the following papers : (1) Chair- 
man’s Letter, p. 3; (2) Director’s Report, pp. 5-7; (38) Geo- 
logical Survey of Partsof Vryburg, Kuruman, Hay and Gordonia, 
by A. W. Rocers, pp. 11-122, two maps and 13 figures; (4) 
Geological Survey of Portions of Mafeking and Vryburg, by A 
L. DuToir, pp. 123-157, figs. 3; (5) Geological Survey of 


Geology and Mineralogy. 583 


Portions of Hopetown, Britstown, Prieska and Hay, by A. L. 
Du Tort, pp. 161-192, 1 fig. Cape Town, 1908.—Practically 
all of the work described in the reports mentioned has been done 
in territory heretofore unknown to geologists, and the Survey 
deserves much credit for its persistent study of inaccessible 
localities. It is surprising to find that the Cape Survey has been 
able to do such a large amount of creditable reconnaissance work, 
with a combined salary list of less than $5,000. H. E. G. 

5. Bergensfeltet og tilstédende Trakter i senglacial og post- 
glacial tid ; af C. F. KotpErupe. Bergens Museums <Aarbog, 
1907, No. 14, 8°, pp. 266, map and 38 figs—The author has made 
a careful study of the ancient shore lines and surficial deposits 
in the region about Bergen on the west coast of Norway, and 
from these investigations draws certain conclusions regarding the 
movement of the ice during the last glacial period, the elevation 
and depression of the land with respect to the sea, and the effects 
of these upon the life of the period as shown by faunal groups. 

The evidence shows a retreat of the ice, an interglacial period, © 
and a renewed advance of the ice, and this is general and not con- 
fined to asingle glacier. The faunal evidence is not conclusive that 
the interglacial time was essentially warmer. Since the different 
series of the terminal moraines in the Bergen district lie in the 
inmost parts of the fiords, the area must have been at that time 
comparatively free from ice, but that the glaciers attained the 
_ sea is shown by the fact that these moraines are stratified, and 
since they are 40-50 meters above the present sea-level the land 
was then correspondingly depressed. From this the land grad- 
ually sank to the level shown by the highest terraces which are 
found in all the large fiords, and which the writer designates as 
the Yoldia terraces. ‘Then the ice retreated and the land rose to 
about its present position, not steadily but intermittently, with 
periods of rest which the author discusses. Morever, in post- 
glacial time this was interrupted by an interval of downward 
movement, when the land stood some 10-14 meters lower than at 
present. 

Divisions of time like those in the Christiania region cannot be 
carried out here since only the highest shell deposits, and not the 
corresponding clay beds with their contained fossils of post- 
glacial time, have been elevated above the sea. Dredging, how- 
ever, shows that they. are present. Thus the available fossils are 
not decisive of conditions. 

Finally shell deposits from Hardanger, Stord and Nordland 
are described. 

The whole is an important addition to our knowledge of the 
glacial geology of western Norway. Li VeP 

6. Wikroskopishe Physiographie der massigen Gesteine ; 
FEirgussgesteine von H. Rosensusca. 4'° Auflage, 8°, pp. 717-1592. 
Stuttgart, 1908.—The appearance of the first part of the 
fourth edition of this great work has been already noted in this 
Journal (vol. xxiii, page 394, 1907). It is now completed in the 


584 Scientific Intelligence. 


second part, which has recently been issued. This deals, as the 
title suggests, wholly with the effusive rocks, to which over half 
the work is thus dedicated. An advance over the last edition is 
to be noted in that age distinctions among these rocks is now 
done away with and, although the names are still given at each 
section heading, as basalt, diabase and melaphyre for example, 
the rocks and component minerals are treated collectively 
according to the plan followed in the author’s Gesteinslehre. <A 
new feature is the erection of the trachydolerite and of the lam- 
prophyric lavas into independent rock groups. 

This work is so well known and universally used that further 
comment is unnecessary. The new edition is a practical necessity 
for every working petrographer. ‘The author is to be congratu- 
lated upon the completion of a task of such magnitude. 

Leva Br 

7. Die Fossilen Insekten und die Phylogenie der rezenten For- 
men ; von ANTON Hanpuirscu. Pp. vii-ix, 1281-1430. Leipzig, 
1908 (Wilhelm Engelmann).—This ninth part completes this very 
important work, which has been repeatedly noticed in these pages. 
An exhaustive index fills the closing twenty-seven pages. 

8. Gahnite from Charlemont, Mass.; by Grorer M. Fiinr 
(communicuted).—A new locality for spinel has been added to 
the list of Massachusetts occurrences of this mineral, by the dis- 
covery, by the writer, of gahnite, at Charlemont, Franklin Co., in 
April, 1908. The mineral occurs in complex rocks, of highly 
metamorphic character, in the Hawley schist (hornblende-chlorite 
schist and hornblende-sericite schist) at a point near its contact 
with the Goshen schist. In this same series of rocks at a distance 
of about 44 miles, air-line, the Rowe occurrence of this same 
mineral* is located. The material collected was taken from the 
dump of a newly developed pyrite mine about one-quarter of a 
mile south of the railroad station, and at the foot of the north- 
easterly slope of Mt. Peak. } 

The gahnite is in aggregates of black and greenish black 
crystals which commonly show a greenish color on fracture; 
also in the uncommon form of single crystals in quartz ; 
and more rarely in a chloritic matrix, in which latter case it is 
associated with tremolite, chloritoid, feldspar, quartz, pyrite and 
some other minerals. The crystals range from 2 to 12°™ in 
length and many show the striated faces common in this species. 
The forms represented are the octahedron, octahedron modified 
by dodecahedron, and the octahedron twinned in accordance with 
the usual spinel law. 

9. Hints for Crystal Drawing ; by Marcarer ReEExks, with 
Preface by Joun W. Evans. Pp. xx, 148, with 44 plates. 
London, 1908 (Longmans, Green and Co.).—This small book 
gives detailed directions for the plotting of axes and the drawing 
of crystal figures upon them ; a chapter on the drawing of twins 
is added. ‘The directions are explicit and the study of the many 


* See A. G. Dana in this Journal, xxix, 455, 1885. 


Botany. 585 


figures with which the book is illustrated should enable the 
student having some acquaintance with the methods of mechan- 
ical drawing to acquire considerable facility in the construction 
of such figures by following out the examples given. The 
methods, so frequently used to-day, of drawing crystal figures 
from the gnomonic or stereographic projections, are not dis- 
cussed. W. EL F. 


Ill. Botany. 


1. Systematic Anatomy of the Dicotyledons, A Handbook 
_ for Laboratories of pure and applied Botany; by Dr. Hans 
SOLEREDER, Professor of Botany in the University of Erlangen. 
Two volumes, Oxford, 1908. (The Clarendon Press.)—The 
translation has been carefully done by Messrs. L. A. Boodle and 
F. EK. Fritsch, and revised by Dr. D. H. Scott. The text of the 
German edition is not easy to translate into smooth English, but 
the translators and editor, between them, have accomplished this 
inaremarkable manner. They have also cleared up some obscuri- 
ties in the original, and have made the whole treatise entirely 
available to the English-speaking student. 

Even before achromatic lenses began to reveal with certainty 
the forms of plant-tissues and their constituents, numerous investi- 
gators had carried on researches in this field and had begun to 
encumber the science of microscopic anatomy with useless terms. 
And, when the improved lenses unfolded surprises in every direc- 
tion, the framework of plants was subjected by zealous students 
to a renewed and very thorough examination. The works which 
preceded the studies based on development were accurate and 
important, but they were excessively confusing, owing to a dis- 
regard of any convention as to terminology. The same term was 
often applied by different authors in different ways and differ- 
ent terms were not unfrequently applied to the same object. 
Again, there were some purists who insisted upon making the 
most absurd and minute distinctions and who revelled in compli- 
cated systems of tissues. For instance, it was not unusual to 
describe the innumerable variants in ordinary parenchyma, giving 
to each element a special name. After the scientific investigation 
of tissue development was fairly under way, certain new terms 
were introduced, but there was at the same time a disposition to 
clear away many of the old terms and much of the rubbish which 
had been so long accumulating. With the appearance of deBary’s 
Comparative Anatomy a still further step was taken towards 
coordination, and from that time there has been a well-established 
consensus as to the use of technical terms. 

From the foregoing can be gathered some idea of the enormous 
difficulty of the task undertaken by Solereder. It was nothing 
less than to sort out from the mass of heterogeneous material 
which had been so long in disordered heaps, the essential charac- 


Am. Jour. Sc1.—Fourts Srerizs, Vot. XX VI, No. 156.—DrcEmsER, 1908. 
4] 


586 Scientific Intelligence. 


ters of tissues in all of our dicotyledonous plants. By an ingeni- 
ous method of arrangement this was made not only clear but 
also useful. The well-ordered results are now accessible to histo- 
logical students and to practical investigators of economic pro- 
ducts, so that the treatise is useful, as the title-page says, for 
laboratories of pure and applied botany. ‘The large treatise not 
only shows what has been done, but it also points out with morti- 
tifying sharpness the vast gaps in our knowledge of the histo- 
logical morphology of plants. | 

Such a treatise is helpful by its stimulating character. It 
happens to be more than this. It indicates not only what has 
been done, and what there is to do, but it shows forcibly the 
worth of it all. In the concluding pages the author has given 
most valuable hints as to some speculative features of the subject, 
and although these are merely hints, they are likely to prove of 
profit to everyone who seriously studies the work. It is question- 
able whether the scientific world in general is aware of the deep 
obligation under which the English botanists are placing their 
fellow students by the publication of the recent important series 
of translations of German works in an attractive form. The 
present number of that series is one of the most valuable. 

G. 5. & 

2. A Text-book of Botany and Pharmacognosy ; by Henry 
KrarMeER, Ph.D. 3d Edition. Pp. viii, 850. Philadelphia, 1908 
(Lippincott Co).—Prof. Kraemer’s duties in connection with the 
Philadelphia College of Pharmacy have shown. him the desirabil- 
ity of providing, for students of pharmacy and for pharmacists, a 
reference book which can answer the more important questions 
in regard to the structure of medicinal plants and the principal 
characters of their useful products. ‘The morphology of plants 
in general and the special morphology of the higher plants are 
treated in part first in considerable detail, and this is followed 
by comprehensive studies of the different families of plants 
yielding drugs. The sequence of families is that generally 
adopted, namely proceeding from the lower to the higher, closing 
with Composite. It is well known to our readers that now-a- 
days, the practical study of Botany is no longer insisted upon as 
an introduction to medical training, largely because the prepar- 
ation of medicinal agents from the vegetable kingdom has fallen 
properly into the hands of specialists known as pharmacists. It 
was plausibly asserted that medical students did not have time 
which could be given to a subject like Botany, so remote from 
their daily needs as practitioners, and aithough regrets were 
expressed that a study so well fitted for preparatory discipline 
must be given up, it disappeared quietly from the list of obliga- 
tory subjects.. Even in those European universities which still 
retain it in the medical curriculum, its tenure is most precarious. 
However, practical Botany is safe in the charge of the excellent 
pharmacists now conducting our best schools of pharmacy. 
From the first part of Professor Kraemer’s book, the student can 


Botany. 587 


obtain the facts which he needs in regard to the forms and affini- 
ties of the higher plants, but will find in the treatise hardly any- 
thing which may be called vegetable physiology, a subject 
which examines the way in which medicinal as ‘well as other 
plants create their useful products. Some valuable hints in regard 
to plant life are given here and there, but it is to be hoped ‘that 
in a fourth edition of the text- book, ‘the chapter on the culti- 
vation of medicinal plants may be so “enlarged as to comprise the 
underlying principles of plant-functions. ‘The second part of the 
book is given up to the examination of drugs, and is well propor- 
tioned. More liberal use could well have been made of photo- 
micrography, for the original illustrations as well as the copies 
are most helpful. Professor Kraemer will perhaps hereafter 
give greater definiteness to some of the statements regarding 
very interesting points, which would be excellent subjects for 
work by his advanced students; such, for instance, as Hama- 
melis. Excellent tables and keys make the work handy in the 
best sense of the term, and render it useful for food- and drug- 
analysts as well as pharmacists. In important particulars. it 
supplements some recent trustworthy treatises which are chiefiy 
devoted to food-products. For American students who are not 
familiar with French or German, the present volume of Phar- 
macognosy will prove invaluable. G.. Ee 

3. Die Gestalts- und Lageverdinderung der Pflanzen- Chrom- 
atophoren ; mit einer Beilage: Die Lichtbrechung der lebenden 
Pflanzenzelle; von Gustav Senn. Pp. xv, 397, with 83 text- 
figures and 9 plates. Leipzig, 1908 (Wilhelm Engelmann).— 
In this volume the author has siven the most complete account of 
the changes in form and position of chlorophyll-grains and color- 
eranules~ which has yet been published. Its value is much 
enhanced by the excellent table of contents and an exhaustive 
index, but it is even more increased by what is, until recently, 
lacking in most German treatises upon similar subjects, namely, 
clear and comprehensive summaries or abstracts, at convenient 
points throughout the work. When we remember that the 
differentiated protoplasmic bodies which are collectively termed 
Plastids, play such an important part in all plant activities, every- 
thing which can add to the knowledge of the behavior of these 
under external and internal influences must be heartily welcomed. 
Dr. Senn has given usa well-proportioned treatise which embodies 
the most essential features of the literature of the subject, and 
has also added a supplement which considers a cognate matter 
of great importance, namely, the refractive power of living 
vegetable cells. He gives to the clear cell-wall and its lining of 
protoplasma the refractive index 1°47 to 1°52, while that of the 
cell-sap therein contained is only a trifle higher than that of 
water. From these figures it is not difficult to determine the 
distribution of light and shade within the cells of living plants. 
The bearing of this on the subject of ecology is very plain. G. L. G. 


588 Scientific Intelligence. 


ITV. MuscentAnrous Screntiric INTELLIGENCE. 


1. National Academy of Songaces —The autumn meeting of 
the National Academy was held in Baltimore on November 17-18. 
About thirty-five members were in attendance. The following 
is a list of the titles of papers presented: 


H. F. Osporn: The close of the Cretaceous and beginning of the Eocene 
in the Heli Creek region of Montana; based on explorations of the American 
Museum between 1902 and 1908. 

A. G. WEBSTER: On the distribution of sound from the megaphone, or 
speaking trumpet. 

H. 8. JeEnninGs: Elementary species and the effects of selection in a uni- 
cellular organism. 

R. W. Woop: Absorption spectra of mixtures of metallic vapors. The 
mercury paraboloid as a reflecting telescope. 

H. N. Morse: Results obtained in the direct measurement of osmotic 
pressure. 

Simon FLEXNER: Certain examples of bio-chemical control of cell devel- 
opment. (a) Metaplasia of transplantable tumors ; (6) Inhibition of Spiro- 
cheta pallida. 

R. H. CHITTENDEN: Further studies on the effect of a low protein diet on 
high protein animals. 

ALEXANDER AGAssiz: The work of the U. S. Fish Commission ship 
‘* Albatross.” 

A. Acassiz and H. L. Cuarx: The Hchini of an insular fauna. 

H. C. Jones and J. A, ANDERSON: The absorption spectra of solutions of 
certain salts. 

JoHn B,. Watson: The reactions of primates to monochromatic lights. 

EK. G. Conxuin: Effects of centrifugal force on the organization and 
development of the eggs of certain animals. 

C. R. Van Hise: The phosphates of the soil. 

B. O. Petrce: Biographical memoir of Joseph Lovering. 

W. H. Datuand W. H. Brewer: Biographical memoir of William M. 
Gabb. 

CHARLES S. Hastines: Biographical memoir of Josiah W. Gibbs. 


2. National Antarctic Expedition, 1901-1904. Meteorology. 
Part I. Observations at Winter Quarters and on Sledge Journeys, 
with discussions by various authors. Pp. xiv, 548, with 4 maps, 
London, 1908. (Published by the Royal Society.)—It will be 
remembered that the explorations of the National Antarctic 
Expedition, between 1901 and 1904, were carried on by the ship 
“ Discovery ” under command of Commander R. F. Scott. The 
ship wintered at the south extremity of Ross Island in latitude 
77° 51’, and longitude 166° 45’ E., in close proximity to the lofty 
volcanoes of Mt. Erebus and Mt. Terror. 

The present volume gives the results of the meteorological obser- 
vations of the expedition made under the direction of Lieut. 
Royds. The complete record of observations taken at the winter 
quarters is given in detail and also that of the sledge journeys, of 
which the journey of Captain Scott reached 82° 16' 33” south 
latitude. The range of temperature observed was from a max- 


Miscellaneous Intelligence. 589° 


imum of 42° F. to a minimum of —58°5°, with very rapid and 
violent fluctuations at all seasons but not always associated with 
changes of wind direction. It was found that polar winds 
brought with them an increase of temperature. The summers 
were remarkably cold with but few days having a mean temper- 
ature above 32°. The highest daily mean noted was 26 2° and 
the lowest —21°. The air was found remarkably dry and trans- 
parent with but little fog and slight precipitation, and the sun- 
shine was remarkably abundant. In December, 1903, for 
example, an average of 16 hours per day was registered. The 
range of pressure was between 30°181 and 28°140 inches, and the 
observations showed the common  semi-diurnal oscillations 
amounting to ‘002 inches. Other interesting points are brought 
out in the report, which gives also asummary of results at other 
stations in the antarctic. The volume is accompanied by a series 
of large maps and some excellent reproductions of views and of 
solar phenomena. | 

Physical Observations with discussions by various authors. 
Pp. v, 192, 21 plates, 2 maps.—The subjects discussed in this vol- 
ume are as follows: Tidal observations in the Antarctic, 1902-8 ; 
pendulum observations ; earthquakes and other.earth movements 
recorded in the Antarctic, 1902-3 ; auroral observations 1902-3 ; 
magnetic observations, 1902-4. The magnetic observations 
have a particular interest because they were carried on at numer- 
ous points in the proximity of the south magnetic pole. The 
probable position of the pole was determined independently by 
observations of the declination, and also by those of the inclina- 
tion. The results obtained in the two cases agree within a few 
minutes of each other. The mean of the two positions, viz. 
latitude 72° 51’S., longitude 156° 25’ E., is regarded as a close 
indication of the center of the polar area. This position places 
the pole about 200 geographical miles east of the place assigned 
to it by Sabine (1841), indicating a probable change of position 
in this direction. 

It is noted that the auroral displays, although frequent, were in 
general extremely poor. A series of excellent plates, however, 
represent some exceptional cases of striking character ; in these 
irregular bands, made up of rays or vertical shafts close together, 
formed the so-called draped aurore. 

3. Road Preservation and Dust Prevention; by WiLiiaAM 
Pierson Jupson. Pp. 146. New York, 1908 (The Engineering 
News Publishing Co.).—The subject of this book is one in which 
recent developments have made our communities more deeply 
interested than ever before, viz., the preservation of the surface 
of macadamized roads and the prevention of dust in connection 
with them. ‘Those concerned with this topic will find the matter 
presented from the practical standpoint, with a careful consider- 
ation of the various methods that have been suggested for 
accomplishing the ends in view. 


590 . Scientific In telligen Ce. 


4, Ostwald’s Klassiker der Hxakten Wissenschaften. Leipzig, 
1908 (Wilhelm Engelmann).—The following list includes the 
titles of recent additions to this valuable series of scientific 
classics (cf. xxv, p. 534). 

Nr. 163. Chemisch-optische Untersuchungen; von J. H. JEL- 
LeTT. Ubersetzet von L. Frank. MHerausgegeben von W. 
Nernst. Pp. 84, mit 6 Figuren im Text. 

Nr. 164. Newton’s Abhandlung tiber die Quadratur der Kur- 
ven (1704). Aus dem Lateinischen tibersetzt und herausgegeben ; 
von GERHARD KowaLEwsxi. Pp. 66, mit 8 Textfiguren. 

Nr. 165. Neue Stereometrie der Fasser, besonders der in der 
Form am meisten geeigneten dsterreichischen, und Gebrauch der 
kubischen Visierrute. Mit einer Erginzung zur Stereometrie des 
Archimedes; von JoHANNES KeEpier. Linz 1615, Druck von 
JOHANNES Prank. Aus dem Lateinischen tibersetzt und heraus- 
gegeben von R. Kiue. Pp. 130, mit 29 Figuren im Text. 

5, Hlementary Dynamics ; by Ervin 8. Ferry, Professor of 
Physics in Purdue University. Pp. 182. New York, 1908 (The 
Macmillan Company).—A teacher interested in his work is apt 
to feel like giving it permanent form in a text-book. But in 
most cases his methods are so peculiar to himself as to render 
the book of little value out of his own hands, and this is the chief 
reason why half the elementary text-books have so little excuse 
for going before the public. This is especially true of text-books 
on Mechanics, for in them preéminently peculiarities are apt to 
be faults—and their besetting fault is bad logic. 

These criticisms do not apply to Professor Ferry’s book, for 
reasons which best appear from the author’s statement in the 
preface of his conception of how this difficult subject should be 
presented to beginners : 

‘All technical terms should be accurately and _ succinctly 
defined. In all definitions the physical nature of the thing has 
been emphasized instead of the mathematical formula which 
expresses its magnitude. * * The number of propositions 
derived from experience and experiment that are to be taken as 
fundamental should be as few as possible. It has been found that, 
with the exception of the properties of matter,-all the laws of 
dynamics can be deduced from five simple propositions derived 
from experience and experiment. * * ‘The laws of the sub- 
ject should be deduced from the definitions and fundamental 
principles by rigid methods whenever the advancement of the 
student will justify it. To habitually accept without proof such 
laws as the parallelogram of forces because they agree with 
experience induces a flabby condition of the mind. It is, however, 
more dangerous to employ mathematical methods with which the 
student has had insufficient practice.” W. B. 

6. Plane and Solid Geometry; by Eimer A. Lyman. Pp. 
340. New York, 1908 (American Book Company).—This is a 
book through which the student must work his way, relying on 
his reasoning powers rather than on his memory. The subject 


Miscellaneous Intelligence. 591 


matter.is very much abridged, many unimportant theorems being 
inserted as exercises. The treatment of the Theory of Limits is 
very much simplified. Historical notes are introduced extensively 
and add much to the value of the book. 

7. Moral Instruction and Training in Schools. Report of an 
International Inquiry. 'Two volumes, edited by M. E. Sap.e=r. 
Vol. I, The United Kingdom ; pp. lv, 538. Vol. II, Foreign 
and Colonial; pp. xxvii, 378.—The investigations which have 
yielded the results given in these volumes had their origin in a 
private conference held in London in the autumn of 1906, to 
consider what steps could be taken to improve the moral instrue- 
tion and training in schools. A _ provisional committee was 
appointed at that time and, later, the council was joined by 
several hundred persons, an executive committee being appointed 
on February 5, 1907. A committee for the United States was 
also selected with Dr. Nicholas Murray Butler as chairman. 

Volume I contains, after the introduction by Prof. M. E. Sadler, 
a series of 33 chapters by different authors, discussing the subject 
from different standpoints in its relation to schools in Great 
Britain and Ireland. The second volume continues the discussion 
in a series of 24 chapters, as related to the schools of France, 
Germany, Switzerland, Belgium, Norway, Denmark, the United 
States, Canada, Australia, New Zealand and Japan. A large and 
varied amount of information is thus presented to the interested 
public. 

8. Practical Exercises in Physical Geography ; by WitiiaM 
Morris Davis. Pp. 144, with atlas containing 45 pls. (45 pp.) 
New York, 1908 (Ginn & Company).—The study of land forms, 
as a part of the instruction in physical geography in high schools, 
has not commended itself to a great many successful teachers. 
The trouble has been that illustrations of different stages of the 
development of land forms were not at hand. “ Practical Exer- 
cises” will do much to remedy this defect. The method of illus- 
tration by block diagrams, as used in the “atlas,” will readily 
commend itself to all students of physical eeography. H. E. G. 

9. Twenty-Sixth Annual Report of the Bureau of American 
Hihnology. 1904-5. Pp. xxxi, 512, tvu1 plates, 117 figures. 
Washington, 1908 (Government Printing Office).—The present 
volume contains the adminstrative report of the Chief of the 
Bureau, W. H. Holmes; also two extended memoirs, one by 
Frank Russell on the Pima Indians (pp. 3-389), and the second 
by John R. Swanton on the Social Condition, Beliefs and Lin- 
guistic Relationship of the Tlingit Indians of Alaska (pp. 391- 
485). Both papers are liberally illustrated with excellent plates, 
in addition to text-figures. 


OBITUARY. 


Dr. Witxr1am K. Brooks, Professor of Zoology in Johns Hop- 
kins University, and author of numerous important contributions 
on zoological subjects, died in Baltimore on November 12 in his 
sixty-first year. 


INDEX TO VOLUME 2x3 


A 


Academy, National, meeting at Balti- | 


more, 588. 

Adirondack iron ores, geology, New- 
land and Kemp, 238. 

Allen, E, T., rdle of water in trem- 
olite, 101. 

Alpha-rays, range of, Duane, 465; 
retardation, Taylor, 169. 

Antarctic Expedition, National, 588. 

Arldt, T., Entwicklung der Konti- 
nente, 512. 

Ashman, G. C., radium emanation, 
Iu) ¢ preparation of urano-uranic 
oxide, O21. 

Association, American, meeting at 
Hanover, 100. 

— British, ‘meeting at Dublin, 404. 


B 


Barus, C., standardization of the 

fog chamber, 87;. Thomson’s con- 
stant, 324. 

Bergen, Norway, glaciation, 
Kolderup, 583. 

Bi-quartz wedge plate, Wright, 391. 

Blair, A. A., Chemical Analysis of 
Tron, 511. 


etc., 


BOTANY AND BOT. WORKS. | 


Algenflora der Danziger Bucht, 
Lakowitz, 168. 

Botany, Gray’s New Manual, Rob- 
inson and Fernald, 518. 

—Text-book, Kremer, 586; Stras- 


burger, Noll, Schenck and Kar- 
sten, 168. 

Cyperacez, studies in, No. X XVI, 
Holm, 478 

Dicotyledons, Anatomy, Solereder, 
080 


Flora, Origin of a Land, Bower, 
Pflanzen - Chromatophoren, Senn, 
087. 
See also GEOLOGY. 
Bower, F. O., Origin of a Land 
Flora, 167. 
Brazil, Shaler expedition, 404. 


Browning, P. E., estimation of 
cerium, 83. 

Bumstead, H. A., Lorentz-Fitz- . 
Gerald hypothesis, 498. 

Butler, G. M., Handbook of Minerals, 


167. 
Cc 


| Canada geol. survey, 239, 514. 


Canada’s Fertile Northland, Cham- 
bers, 520. 

Cape of Good Hope, geol.'map, 98; 
geol. survey, 582. 

Carnegie Institution, publications, 
99, 519. 


CHEMISTRY. 


Acidimetry, alkalimetry, standards 
in, 138, 143. 

Argon, preparation, Fischer and 
Ringe, d11, 

Barium, determination, 
Langley, 128. 

Calcium salts, complex, d’Ans, 399. 

Cerium, estimation, Browning and 
Palmer, 83. 

Chlorates, volumetric method for, 
Knecht, 91. 

Chromic and vanadie acids, estima- 
tion, Edgar, 333. 

Chromium, estimation of, Gooch 
and Weed, 83; thermal con- 
stants, Mixter, iB. 

Cobalt ‘with carbon monoxide, 
Hirtz and Cowap, 570. 

Cobalti-nitrite method, Drushel, 
329. 

Copper, volumetric method for, 
Jamieson, 92. 

Esters, esterification, etc., Phelps, 
Tillotson, Eddy, Palmer, Smillie, 
243, 208, 257, 264, 267, 275, 281, 
290, 296. 

Helium, rate of production from 
radium, Dewar, 575. 

Iodimetry, standards in, 148. 

Iron and vanadium, estimation, 
Edgar, 79. 

Malonic acid, esterification, Phelps 
and Tillotson, 243, 257, 267. 


in rocks, 


* This Index contains the general heads. BOTANY, CHEMISTRY (incl. chem. physics) , 
GEOLOGY, MINERALS, OBITUARY, ROCKS, ZOOLOGY, and under each the titles of Articles. 


referring thereto are mentioned. 


E. 
~ ~~ 


INDEX. 


CHEMISTRY—continued. 


Nitrogen, utilization of atmosphe- | 
ric, Frank, 509. 

Oxides, heat of combination of 
acidic, Mixter, 125. 


Phosphorus i in phosphor tin, Gem-_ 


mell and Archbutt, 399. 
Polyiodides of potassium, etc., 
Foote and Chalker, 92. 
Potassium, 
fluids, Drushel, 555. 
Radium, see Radium. 
Urano-uranic oxide, McCoy, 521. 
Vapor densities, 
Blackman, 400. 
Civilization, Physical Basis, Heine- 
man, 241. 
Clark, H. L., apodous holothurians, | 
100. 


Clarke, J. M., Devonic history of. 


New York, 93. 


Clement, J. K., water in tremolite, | 
new measurements with gas_ 


101; 
thermometer, 405. 


Cockerell, T. D. A., Tertiary plants, | 


65, 537; Tertiary insects, 69. 
Continents, origin, etc., 238, 512. 
Colorado, Florissant, Tertiary plants, 

65, 537 ; insects, 69, 76. 

Crew, [ni , Principles of Mechanics, 

580. 


Crystal Drawings, Reeks and Evans, | 


584. 
Cyanide Processes, Wilson, 576. 


D 


Dahomey, Mission Scientifique, Hu- 


bert, 515. 


Daly, R. A., mechanics of igneous | 


intrusicn, 17. 
Day, A. L., new measurements with | 
gas thermometer, 405. 


Davis, W. M. , Physical Geography, | 


591. 

Drushel, W. A., estimation of potas-| 
sium, 329, 009. 

Duane W., 
from radium, A 
465. 

Dynamics, Ferry, 590. 


; range of a-rays, 


E 


Earthquake Investigation 
mittee, Japanese, 240. 

Eddy, E. A., ester formation, etc. 
253, 281, 296. 

Edgar, G., estimation of iron and 
vanadium, 79; of chromic and van- 
adic acid, 333. 


Com- 


estimation in animal | 


determination, | 


emission of electricity 


593 


' Electric discharge, magnetic rotation, 
Mallik, 576. 
‘Electricity, emission from radium, 
Duane, 1. 
— Experimental, Searle, 580. 
| Electrons, emission from metallic 
oxides, Jentzsch, 512. 
= negative kinetic energy of, Rich- 
ardson, 512. 
Ethnology, American, 26th Annual 
Report, 591. 
_Evolution of J’orces, Le Bon, 579. 
Extinction angles, measurement of, 
Wright, 349. 


F 


| Fernald, M. R., Gray’s Botany, 518. 
|Flint, G. M., gahnite, 584, 

Flora, se BOTANY. 

Florida geol. survey, 581. 

Fog chamber, standardized, Barus, 
87; Thomson’s constant deter- 


mined, 324. 
Ford, W. E., orthoclase twins, 149. 
Fossil, see GEOLOGY. 


G 


Gas thermometer, Day and Clement, 
405. 


“GEOLOGICAL REPORTS AND 
SURVEYS. 


Canada, 239; Index to Reports 
1885-1906, 514. 

Cape of Good Hope, 582. 

| Florida, 581. 

| Tllinois, 166. 

| Iowa, vol. xvii, 97. 

| Maryland, vol. vi, 97. 

| New Jersey, 1907, 514. 

| United States, list of publications, 
95, 402. 

West Australia, 166. 
West Virginia, 581. 
Wisconsin, 98, 582. 

| Geologische Prinzipienfragen, ‘Reyer, 

238. 


‘GEOLOGY. 


Archhelenis and Archinotis, 
Thering, 513. 
Camarophorella, Hyde, 514. 
Ceratopsia, Hatcher, 98. 
Channels, buried, of Hudson river, 


von 


Kemp, 3801. 
Devonic history of New York, 
Clarke, 93. 


Fossilen Insecten, Handlirsch, 584. 
Graptolites of New York, Ruede- 
mann, 402. 


504 


GEOLOGY— continued. 


Horse from the lower 
Loomis, 1638. 

Hybocystis in Ontario, Parks, 240. 

Magnetic iron ores, Adirondack, 


geology, Newland and Kemp, 238. | 


Meso-Silurian deposits of Maryland, 


Prouty, 563. 

Miocene, lower, horse from, 
Loomis, 163; Rhinocerotidz 
from, 951. 

Paleozoic rocks, lower, of New 


Mexico, Lee, 180. 
Permian of India. Koken, 165. 
Rhinocerotidz of lower Miocene, 


Loomis, 5}. 

Stromatoporoids, Niagara, Parks, | 
240. 

Tertiary insects, Cockerell, 69;_ 


Wickham, 76. 
— plants, Cockerell, 65, 537. 
Turtles, Fossil, of North America, 
Hay, 516. 
Geometry, Lyman, 590. 
Glaciation, at Bergen, Norway, 588. 
— Permian in India, 165. 


Glaciers, periodic variations, Bruck-| 


ner and Muret, 98. 

Glass, reflection at polarizing angle; 
Rayleigh, 512. 

Gooch, F. A., estimation of chrom- 
ium, 8d. 

Gravitation, hypothesis of, discussed, 
Bumstead, 493. 


H 


Haber, F., Thermodynamics, 92. 
Hale, G. E., Stellar Evolution, 577. 


Handlirsch, A., Fossilen Insekten, | 


584. 

Hatcher, J. B., Ceratopsia, 98. 

Hay, O.H., Fossil Turtles of North 
America, 516. 


Heineman, T. W., Physical Basis of | 


Civilization, 241. 


Hofmeister, F., Beitrige zur chemi- | 


schen Physiologie, 520. 

Holm, T., Studies in the Cyperacee, 
XXVI, 478. 

Howe, E., Geology of the Isthmus of 
Panama, 212. 

Hubert, H., Dahomey Mission, 510. 


Hudson fiver, buried channels, 
Kemp, 301. 

I 
Igneous intrusion, mechanics of, 
Daly, 17. 


Miocene, | 


INDEX. 


Ihering, H. von, Archhelenis and 
Archinotis, 518. 

Illinois, geol. survey, 166. 

Insects, Tertiary, Cockerell, 69 ; 

| Wickham, 76. 

Insekten, Fossilen, Handlirsch, 584. 

prerere ne phenomena, Wright, 

6. ; 
Iowa, geol, survey, 97. 
Iron, Chemical Analysis, Blair, 511. 


J 


Japanese Earthquake Investigation 
Committee, 240. 


| K 

‘Kemp, J. F., buried channels of 
Hudson river, 301. 

Kohler P. O., Entstehung der Kon- 
tinente, 238. 

Koken E., Indian Permian, 165. 

Kontinente, Entstehung, Kohler, 
238; Entwicklung, Arldt, 512. 
Kraemer, H., Botany, 586. 


L 


Lacroix, A., Mt. Pelée after its 
eruptions, 400. 

Lagunari, Ricerche, 520. 

Lamb, A. B., Thermodynamics, 92. 

Langley, R. W., barium in rocks, 
123. 

Le Bon, G., Evolution of Forces, 
579. 

'Lee, W. T., lower Paleozoic rocks 
of New Mexico, 180. 

Lewis, J. V., Palisade diabase of 
New Jersey, 155. 

Linnaeus, Suringar, 168. 

| Loomis, F. B., lower Miocene Rhino- 

cerotide, 51; new horse from, 163, 

| Lorentz-FitzGerald hypothesis, 
Bumstead, 493. 

Lull, R. S., Ceratopsia, 98. 


M 


_Magmatic stoping, etc., Daly, 17. 
Magnetic pole, South, 589. 
|Magneto- und Electro-Optik, Voigt, 
1 279: 

Marins, les Dépéts, Collet, 242. 
Maryland geol. survey, 97. 
|— Meso -Silurian deposits, 
| * 563. 

Weather service, 100. 
Matter, Corpuscular ‘Theory, Thom- 
son, 978. 


Prouty, 


INDEX. 3 595 


McCoy, H.N., preparation of urano- | 


uranic oxide, 921. 
Mechanics, Crew, 580. 


MINERALS. 


Amphibole, Linosa, 187.. 
Beryl, water in, 115. Blédite, Chile, 
O47. 


Cinnabar crystals, China, 517. 

Diopside, water in, 1106. 

Gahnite, Mass., 584. 
Mexico, 545. 

Hillebrandite, Mexico, 551. 

Ilvaite, California, 14. 

Kaersutite, Linosa and Green- 
land, 187. Kréhnkite, Chile, 342, 
Kupfferite, water in, 111. 

Natrochalcite, new, Chile, 345. 

Orthoclase twins, 149. 

Spurrite, Mexico, 547. 

Tremolite, water in, 101. 

Minerals, Handbook of, Butler, 167. 
Missouri, Pike County, geology, 

Rowley, 514. 

Mixter, W. G., heat of combina- 

tion of acidic oxides, 125. 

Moral Instruction in Schools, Sadler, 

591. 


Gehlenite, 


Mt. Pelée after its Eruptions, La-. 


eroix, 400. 


N 


Newcomb, S., fluctuations in the 
Sun’s radiation, 93. 

New Jersey geol. survey, 514. 

— Palisade diabase, Lewis, 155. 


New Mexico, lower Paleozoic rocks, | 


Lee, 180. 

New York, Devonic history, Clarke, 
93. 

— State Museum Report, 405. 


O 
OBITUARY. 
Anthony, W. A., 100. 
Béchamp, P. J. A., 100. Becquerel, 


Chalmers, R., 100. 
Delgado, J. F. N., 404. 


404. 
Lapparent, A.,100. Lister, A., 404. 


Mascart, E. E. N., 404. Mébius, 
K, A., 100, 
Observatory, Allegheny, publica- 


tions, 99. 
— Harvard College, publications, 99. 
Ostwald’s Klassiker der Exakten 

Wissenschaften, 590. 


/— emission 


P 


Palache, C., Krohnkite, natrochal- 


cite, etc., from Chile, 342. 


Paleontology, Steinmann, 240. 
Palmer, H. E., estimation of cerium, 


83; ester formation, 290. 
Panama, geology of, Howe, 212. 
Petereit, A. H., cinnabar crystals 

from China, 517. 

Phelps, I. K., standards in alkalim- 
etry and acidimetry, etc., 138, 145; 
esters and esterification. 248, 253, 
207, 264, 267, 275, 281, 290, 296. 

Physical Geography, Davis, 591. 

Physics, General, Crew, 241. 

— The New, Poincaré, 580. 


Physiologie, Beitrige zur chemischen, 


Hofmeister, 520. 


|Pirsson, L. V., Rocks and Rock Min- 


erals, 403. 
Plants, Tertiary, Cockerell, 65, 537. 


Poincaré, L., The New Physics, 580. 
Positive rays, Thomson, 576. 
Prescott, C., ilvaite, 


Shasta Co., 
Cal., 14. 

Prouty, W. T., Meso-Silurian de- 
posits of Maryland, 563. 


R 


Radio-activity, alpha-rays, Taylor, 
169 ; Duane, 465. 


— discussed, Marckwald, 400. 

| — standard of, Duane, 521. 
Radium, atomic weight, Thorpe. 91. 
/_— emanation, Ashman, 119; Curie 


and Gleditsch, 509; Curie, 510 ; in 
the atmosphere, Eve, 577. 

of electricity from, 
Duane, 1. 


_— in tufa deposits, Schlundt, 575. 
'Ransome, F. L., apatitic. minette 


from Washington, 337. 


Reyer, E., Geologische Prinzipien- 


fragen, 238. 


Road Preservation, Judson, 589. 
_Robinson, B. L., Gray’s Botany, 518. 
A. H., 404. Brooks, W. K., 591. 


|ROCKS. 
Hague, J. D., 242. Hansky, As, | 


Barium in rocks, Langley, 123. 
Diabase of New Jersey, Lewis, 155. 
Gabbro, altered, at Cumberland, 
R. I., Warren, 469. 
Igneous intrusion, theory of, Daly, 
EE: 
Minette, apatitic, 337. 
Rocks and Rock Minerals, Pirsson, 
403. 
— work on, Rosenbusch, 583. 


596, 


Rontgen rays, absorption, Seitz, 
Nea TG 


Rosenbusch, H., Physiographie der 
massigen Gesteine, 583. 

Ruedemann, R., graptolites of New 
York, 402. 


Ss 

Sadler, M. E., Moral Instruction in 
Schools, 591. 

Searle, G. F. C., Experimental Elec- 
tricity, 580. 

Son G., Pflanzen-Chromatophoren, 
087. 

Smillie, R., ester formation, 290. 

Solereder, H., Anatomy of Dicotyle- 
dons, 585. 

Steinmann, G., Paleontology, 240. 

Stellar Evolution, Hale, 577. 


Sun’s radiation, fluctuations in, New- 
comb, 93. 


ak 


Taylor, T. S., retardation of alpha- 
rays, 169. 

Telemeter, new form, Wright, 531. 

Thermodynamics of Gas-Reactions, 
Haber and Lamb, 92. 

Thomson, J. J., Korpuskular Theorie 
der Materie, 578. 

Tillotson, E. W., Jr., orthoclase 
twins, 149; esters and esterifica- 
tion, 248, 257, 264, 267, 275. 


U 
United States geol. survey, 95, 402. 


V 


Veatch, A. C., geology of South- 
western Wyoming, 239. 
Vesuvius, map of, 166. 


INDEX. 


Voigt, W., Magneto- und Electro- 
Optik, 579. 


WwW 


Warren, C. H., kréhnkite, natro- 
chalcite,etc., from Chile, 342; alter- 
ation of augite-ilmenite groups in 
Cumberland, R. I., gabbro, 469. 

Washington, H. S., kaersutite, from 
Linosa and Greenland, 187. 

Water vapor, decomposition by 
electric sparks, Holt and Hopkin- 
son, 511. 

Weed, L. H., estimation of chro- 
mium,890; standards in alkalimetry, 
etc., 188, 143. 

West Australia geol. survey, 166. 

West Virginia geol. survey, 581. 

Wickham, H. F., fossil Elateride 
from Florissant, 76. 

Wilson, E. B., Cyanide Processes, 
576. 

Wireless telegraphy, directive sys- 
tem, Bellini and Tosi, 576. 

Wisconsin geol. survey, 98, 582. 

W oodworth, J. B., Shaler expedition 
to Brazil, etc., 404. 

Wright, F. E., optical studies on 
kaersutite, 187; measurement of 
extinction angles, 349; bi-quartz 
wedge plate, 391; new telemeter, 
531; interference phenomena, 536 ; 
three contact minerals from Mex- 
ico, 545. 

Wyoming geology, Veatch, 239. 


Z 
Zeeman effect, Hale, 577. 


ZOOLOGY. 


Apodous holothurians, Clark, 100. 

Phasmids, von Wattenwyl and Red- 
tenbacher, 242. 

See also GEOLOGY. \ 


New Circulars. 


84: Eighth Mineral List: A descriptive list of new arrivals, 
rare and showy minerals. 


85: Minerals for Sale by Weight: Price list of minerals for 
blowpipe and laboratory work. 


86: Minerals and Rocks for Working Collections: List of 
common minerals and rocks for study specimens; prices 


from 1% cents up. 


Catalogue 26: Biological Supplies: New illustrated price list 
of material for dissection; study and display specimens; 
special dissections; models, etc. Syxth edition. 


Any or all of the above lists will be sent free on request. We are 


constantly acquiring new material and publishing new lists. It pays to 
be on our mailing list. 


Ward’s Natural Science Establishment 
76-104 CoLiEcE AVE., Rocurstrer, N. Y. 


Warnp’s Natura Science EstaBlisHMENT 


A Supply-House for Scientific Material. 


Founded 1862. Incorporated 1890. 


DEPARTMENTS: 
Geology, including Phenomenal and Physiographic. 


Mineralogy, including also Rocks, Meteorites, etc. 
Palaeontology. Archaeology and Ethnology. 
Invertebrates, including Biology, Conchology, etc. 
Zoology, including Osteology and Taxidermy. 

Human Anatomy, including Craniology, Odontology, ete. 
Models, Plaster Casts and Wall-Charts in all departments. 


Circulars in any department free on request; address 


Ward’s Natural Science Establishment, 
76-104 College Ave., Rochester, New York, U.S, A. 


————— 


ee 


CONTENTS. 


Art. XLVIL—Preparation of Urano-Uranic Oxide, U, 0, 
and a Standard of Radio-activity ; by H. N. McCox and 3 
‘GLO ASHMAN. (062 2 2U 5 

XLVIII.—Telemeter with Micrometer Screw Adj ae re 
by Et. Hig WRIGHT {0 

XLIX.—Device to Aid in the Explanation of Interference 
Phenonrena,; by Fs EH. WRIGHT 2.2.7 ae <2 anne : 

L.—Deseriptions of Tertiary Plants, Il; by TT. Dewy 
COCKERELL . 0. 20a lesa 

LI.—Three Contact Minerals from Velardefia, Durango, 
Mexico. (Gehlenite, Spurrite and Hillebrandite ;) by 
Bo Roo Weremt 80 eo le 

LIL.—YV olumetric Estimation of Potassium in Animal Fluids; 
by WAS DRUSHEL. 0027 

LUT. aia Silurian Deposits of Maryland; by Ww. EF: 
SPROUL. Ube pe re 


SCIENTIFIC. INTELLIGENCE. 


Chemistry and Physics—Rate of Production of Helium from Radium, J. 
Dewar: Radium in Tufa Deposits, ScaLuNDT: Compound of Cobalt with 
Carbon Monoxide, Monn, Hirrz and Cowar, 575.—Cyanide Processes, E. 
B. WILSON: Magnetic Rotation of Electric Discharge, D. N. MALLIK: 
Directive System of Wireicss Telegraphy, HE. BELLINI and A. Tost: Positive 
Rays, J. J.. THomson, 076.--Radium Emanation in the Atmosphere near 
the Earth’s Surface, Eve: Absorption of RoOntgen Rays, W. Sxitz: Zee- 
man Effect in Solar Vortices, G. A. Hate: Study of Stellar Evolution, — 
an Account of some Recent Methods of Astrophysical Research, G. E. 
Haz, 577.—Korpuskulartheorie der Materie, J. J. THomson and G. 
SIEBERT.—Magneto- und Electro-Optik, W. Voter: Evolution of Forces, 
G. Lr Bon, 579.—Experimental Electricity, G. F. C. Starte: The New 
Physics and its Evolution, L. Poincar&: Principles of Mechanics, H. ~ 
Crew, 580. 

Geology and Mineralogy—West Virginia Geological Survey, I. C. WarrE: 
Florida State Geological Survey, E. H. Smiuarps, 581.— Wisconsin Geo- 
logical and Natural History Survey : Geological Survey of Cape of Good 
Hope, 582.—Bergensfeltet og tilstodende Trakt er i senglacial og postglacial 
Tid, C. F. KotpERupP: Mikroskopishe Physiographie der massigen Ge- 
steine ; Ergussgesteine, H. Rosmnpuscu, 585.—Die Fossilen Insekten und ! 
die Phylogenie der rezenten Formen, A. HanpiirscH : Gahnite, G. Mong 
Fuinr: Hints for Crystal Drawing, M. Rees, 584. 

Botany—Systematic Anatomy of the Dicotyledons, H. SoterepEeR, 985,.— 
Text-Book cf Botany and Pharmacognosy, H. KrammEr, 986.—Die 
Gestalts- und Lageveriinderung der Pfianzen-Chromatophoren, G. SENN, 
587, 

Miscellaneous Scientific Intelligence — National Academy of Sciences : 
National Antarctic Expedition, 1901-1904, 588.—Road Preservation and 
Dust Prevention, W. P. Jupson, 589.—Ostwald’s Klassiker der Kxakten 
Wissenschaften: Elementary Iiynamics, E. S. Ferry: Plane and Solid 
Geometry, E, A. Lyman, 590.— Moral Instruction and Training in Schools 
M. E. SapuER-: Practical Exercises in Physical Geography, W. M. Davis, 
Twenty-Sixth Annual Report of thé Brreau of American Ethnology, 591. 


Obituary—Wiiitam K. Brooxs, 501. 7§ 73 ‘ \t 
XO y, 


Se ween — — 


wa 


‘ 
- + 
: ‘ = ~ = a 3 
* : a ~ 
eee se 
> vi Zz. 
% — - 
* aa. 


iin 


3 9088 01298 5776