Full text of "A treatise on human physiology"

See other formats

This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project
to make the world's books discoverable online.

It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject
to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books
are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.

Marks, notations and other marginalia present in the original volume will appear in this file - a reminder of this book's long journey from the
publisher to a library and finally to you.

Usage guidelines

Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing this resource, we have taken steps to
prevent abuse by commercial parties, including placing technical restrictions on automated querying.

We also ask that you:

+ Make iion-coninieicial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for
personal, non-commercial purposes.

-I- Refrain from autoiiiaTed querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the
use of public domain materials for these purposes and may be able to help.

+ Mainrain attribution The Google "watermark" you see on each file is essential for informing people about this project and helping them find
additional materials through Google Book Search. Please do not remove it.

+ Keep it legal Whatever your use. remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other
countries. Whether a book is still in copyright varies from countiy to country, and we can't offer guidance on whether any specific use of
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner
anywhere in the world. Copyright infringement liability can be quite severe.

About Google Book Search

Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web

at http: //books .google . com/

^ ^C.^/^6^.

HUMAN PHYSIOLOGY.

A TREATISE

HUMAN PHYSIOLOGY;

- ■ bKSlOX^D rdtf t'HR uVb or

STUDENTS AND PRACTITIONERS OF MEDICINE.

JOHN C. DALTON. Jr.. M. D.,

FKOPUMK or rariioiour arr ■icsaaropic ahitomt m the cwLtBui op nnteiAKt ahd icMmn,
SKw tokk; auniiB op tbk rew ioik acidimi up iiu>rcipk; op thm kbw tork

PJLTHOLOOICALIOCIxrT; OP TRk AMKBtClV ACABEMT OP ARTi AKO aCIUiabI,

■OfrrOR, MAM. ; ARD OP TBE BIOLOOICAI. DEPAKTHBHT OP THE

ArADUlT OP RATCKAL KIERCU OP PHtLABELPBIA.

Sittoatt CbitioB, ^tbistb anil ftnUigtli.

V/ITH TWO HUNDRED AND SEVENTY-ONE ILLUSTRATIONS.

PHILADELPHIA:

BLANCHARD AND LEA.

1861.

Entered aooording to the Act of Congreas, in the ^e&r 1859, by

BLANCHARD AND LEA,

ia the Oflice of the Clerk of the DfEtrict Conrt of the United States in and for tlie
Eastern DiBtrict of the State of PennBylTania.

philadklpbia;
colltks, pbinteb, 705 j*t»b street.

F3^

TO MY FATHER,

JOIN C. DALTON, M.D,,

H0HA.OE Of HIS LONG AND SUCOESSfUL DEVOTION

TO tHB

8CIEN0E AND ABT OP MEDICINE,

AMD IV
GRATEriTL BBCOLLECTIOK 07 HIS PROTKSSIONAL PBICIPTS AMD IXAUPLS.

18 BESPECTFtJLLT AND AFFECTIONATELY

INSCRIBED.

PREFACE TO THE SECOND EDITION.

In preseoting a new edition of this work, the author desires to
express his sincere acknowledgments to his professional brethren
for the very favorable manner in which it was received at the
time of its first appearance, two years ago. In the present edition,
the author has endeavored to supply, as fully as possible, the
deficiencies which, he is well aware, existed in the former volame.
Some of these deficiencies were evident to his own mind, while
others were indicated by the suggestions of judicious criticism.
These suggestions, accordingly, have been adopted in all cases in
which they appeared to be well founded, and not inconsistent with
the general plan of the work. In those instances, on the other
hand, in which the views «f the author on physiological questions
seemed to him to be positively sustained by the results of observa*
tton, he has retained these views unchanged in the present edition.
At the same time, he has abstained, as before, from the lengthened
discnssion of theoretical points, and has purposely avoided even
the enumeration of new experiments and observations, wherever
they have not materially affected the position of physiological
doctrines ; for in a work like the present, it is not the object of
the writer to give a detailed history of physiological science, but
only such prominent and essential points in its development as
will enable the reader fully to comprehend its actual condition at
the present time.

The principal additions and alterations which have thus been
fonnd advisable are: —

First, the introduction of an entire chapter devoted to the con-
sideration of the Special Senses, which were only incidentally treated
of in the former edition.

Till

SecoDd, the re- arrangement of ihe clmpter od ibo Cranial I^ervea^
and the iDtroduction of some new views and facts in regard to their
physiology.

Third, nn account of some new experimetits, original with the
jiulhor, relating to the function of the CavUUum, and the conclu-
sions to which they lead.

Fourth, certain considerations respecting the general properties
o? Scmaticti and MoU'on, as resident in the nervous system, which
are important as an introduction to the more detailed study of
these functions.

Fifth, the introduction of a chapter on Imhililion and Exhalation^
and the functions of the Lymphatic System; including the study of
cndosmoais and exosmosia, and their mode of action in the animal
frame, the experiments of Dutrochot, Chevrenil, Gosselin, ^{attcucci,
and others, on this subject, the constitution and circulation of the
lymph and chyle, and, iSnally, a quantitative estimate of the entire
procewcs of exudation and reabsorption, as taking place in the
living body.

Additions have also been made, in various parts, to the chapters
on Secretiun, Excretion, the Circulation, and the functions of the
Digestive Apparatus. In every instance, these alteration!) have
been incorporated with the text in such a manner as to avoid, so
far as possible, increasing unnecessarily the size of the book.

Twenty-two new and original illustrations have been introduced
into the present volume, of which number five replace others in
the former edition, which were regarded as imperfect, either in
design or execution. The remaining seventeen arc additional.

It is hoped that the above alterations and additions will be found
to be improvements, and that they will enable the work, in its pre-
sent form, to accomplish more fully the object for which it was
designed.

H«w VoKx, I'thmary, 1S61.

PREFACE TO THE FIRST EDITION,

This yolnme is offered to the medical profession of the United
States, as a text-book for students, and also as a means of commu-
nicating, in a condensed form, such new facta and ideas in physio-
logy, as have marked the progress of the science within a recent
period. Many of these topics are of great practical importance to
the medical man, as in6uencing, in various ways, his views on
pathology and therapeutics ; and they are all of interest for the
physician who desires to keep pace with the annual advance of his
profession, as indicating the present position and extent of one of
the most progressive of the departments of medicine.

It has been the object of the author, more particularly, to pre-
sent, at the same time with the conclusions which physiologists
have been led to adopt on any particular subject, the experimental
basis upon which those conclusions are founded; and he has en-
deavored, so far as possible, to establish or corroborate them by
original investigation, or by a repetition of the labors of others.
This is more especially the case in that part of the book (Section -
I.) devoted to the function of Nutrition ; and as a general thing,
throughout the work, any statement of experimental facts, not
expressly referred to the authority of some other writer, is given
by the author as the result of direct personal observation.

The illnstrations for the work have been prepared with special
reference to the subject-matter ; and it is hoped that they will be
found of such a character as materially to assist the student in
comprehending the most important and intricate parts of the sub-
ject It is more particularly in the departments of the Nervous
System and Embryonic Development that simple, clear, and faithful

X FBEPACE TO THE FIRST EDITIOX.

illastrationa are indispensable for the proper understanding of tbe
printed descriptions ; the latter being often necessarily somewhat
intricate, and reqairing absolutely the assistauce of properly
arranged figures and ' diagrams. Of the two hundred and 6 fly-
four illostratioDS in the present volume, only eleven have been
borrowed from other writers, to whom they will be found duly
credited in the list of woodcuts.

Of the remaining illustrations, prepared expressly for the pre-
sent work, the drawings of anatomical structures, crystals, and
microscopic views generally, were all taken from nature. The
diagrams were arranged, for purposes of convenience, in such
a manner as to illustrate known anatomical or physiological ap-
pearances, in the most compact and intelligible form.

Physiological questions which are in an altogether unsettled
state, as well as purely hypothetical topics, have been purposely
avoided, as not coming within the plan of this work, nor as calcu-
lated to increase its usefulness.

Nsw YoBK, January 1, ISSfi.

CONTENTS.

INTRODUCTION.

PAOK

DefinftloD of PhjBlology — lu mode of stnd; — Natare of Vital Phenomena —
DiTltion of the subjeot . 33-43

SECTION I.
NUTRITION.

CIIAPTER I.

PBOXIMATB PRINCIPLES IN QENERAL.

Definition of Proximate PriDclplea— Mode of tbeir oxtraction — Manner in which
thej an suociated with eaeh other — Natnral variation in their relative
qoaDtitiea— Three distinct clanes of proximate principles , , 45-92

CHAPTER II.

PEOXIMATE PRINCIPLES OF THE FIRST CLASS.

Inoi^anlo Snixtanees — Water — Chloride of Sodiam — Chloride of Potassium —
Phosphate of Lime — Carbonate of Lime — Carbonate of Soda — Phosphates of
Hagne«ia, Soda, and Potassa — Inorganic proximate principles not altered in
the body — Their disoharge— Nature of their fanctloa . . 53-62

CHAPTER III.

PROXIMATE PRINCIPLES OF THE SECOND CLASS.

Stabch — Percentage of starch In different kinds uf food — Varieties of this
sabsUncfl — Properties and reactions of ataroh — Its conversion into sugar —
HnoAR — Varieties of Bngar*— Pbjsioal and chemical properties — Proportion
in different kinds of food — Pats — Varieties— Properties and reactions of fat
— tta crystallisation — Proportion Ib different kinds of food — Us condition in
the body— Internal prodnotlOQ of fat — Origin and destination of proxtroate
principles of this class ....... 63-78

XII

CO STENTS.

CHAPTER IV.

rsDXIHATB PKINLTipLBS OP TIIB TMIBO OLABS,

rtot

Qeneral oha.raotera of organio sabsUncn — Their alietnml cDuatilution — Hjrgtt>-
Rcopic prci[Mfrti««— Co»giiittion — CftUi1v*ia — Fenn«n[ali<in — I'ntrrfiiction—
Fibrin — Albmuwn— Caaeiu— Glolniline— PBi»iiii?— Fnuorenttiitt— MueosLoa-
OBtelna— CAr(ilii(;ine — Muscatine — tliEmiitiue — MeUnlne — llilirdrdine —
CrcwMiiift— Orlgiu Aud dcsLruulion uf pruximalo i>riiici|>lvs of llits clua 76~£8

CHAPTER V.

or rooD.

Importance of Inorgnnic Hulwlnncni »« ingroilivnti of food — Of fnccharinp and
starchj Dutwunoes — 0/ falty matlurs — lusufllcieDoy of (linitij NubnUnutM
when Dsed alone — EfTooIa of iin rxcluaivn non-nitrogotions diet — Organic
MabntanocN al«u in«iiflii:ipiit by IhornHxlres— Rx)>(-rini(inU of Mngnndift on
exL'luiilve diet of i^elatine or flbHn — Pood riKiTiires to ooutatii jiU cUsa«fl of
prositcate prinoiplvs — Cum pu* it inn of Tarivo> kinds of fuod — Dailjr iiQaulitjr
of fitod r6i|alred b/ man — DlgeaUbitity of food— BlTiicl of oooking . i>V~Vi

CHAPTER TI.

DIOXSTIOK.

If&tuM) (if digfRlIoii — DigeBtUe apparatus of fowl — Of ox— Of man — MAfrrci-
Tion — Varieties of tsctli — Effect of uiattlcatioii — &ALivA~lt« comi>o9hion —
Dall^ qnontitj |>r(Hluo«d — Ita aotiou on elsrcb — Etfuct of Ita Bnppression —
Fnuatiun of tk« saliva — OAinTiiif' Ji-irs, and Stoxacm UiOKsnon — Struct um of
gastrio maoon* inpuibrnii«^I>r. Bnauinout'a exiwriiuviita on St. Martin —
ArliJluial gnalrio llBtalac — CotnpoMJlion mid properties of gastrio Jniue — Itg
ootiflii on albuiiiiuuid lubeiaQoes— Ffri^tulliu aution of Hlouach — Tinio ra-
qulrod for dignation — Dait^ qaantii}' of gastrio JaJce^Inflnem^M modifying
iU MiKinitlon — Ivtb»tixal Jiticki, a»[> thr l>rniwTiOH or Suoab asd Stabch —
FolUclee of intn»tln»^Prupi>rtiRii uf iulestinal juicv— PasicjiicATir. Jurcx, akd
THE DiawTiuN OF Vat — Compoeltion and prop«rtt«e of pannreatic Juiow — Its
action on oily matten — SuocoMiiv<g ohaogca iu int«Kt1iiiil digention — Tho large
ioteatine and Its eonlenta ...... B9-144

CHAPTEK VII.

ABSORpriO.N.

(^0!i«d folUolei and tIIK of small iDtealine — PeHslaltio notion— Absorption
by WoodreMfla and lymphatic* — (^hyle— Lymph— AtwoHwnt aysteui — Lao-
taB.la and lyiiiph«tl«a — Absorpliou of fat — lU ai'vumulatfou In ibe blood
during digestion — Ila Goal deuotupoflilion atid disapp«aniua« . . 14&-157

CONTENTS. Xlll

CHAPTER VIII.

TBB BIU.

PAOl
PfaTBical properties of the bile — Its eompoiitlon — Blllreidine — Cholesterin —
Billu7 BBlts — Their mode of eitrMtlon — Cr7st«llisatloa — Qljko-ohoUtA of
Bodft — Taaro-oh<^te of soda — BiliAry aalti In diferent Bpeoies of aclmAls
and in man— Tests for bil»>-Tariatlona and fanctions of bile— Dallj qoan-
tity — ^Tlme of Its disoharge into intestine — Its disappearance from the alE-
mentaty eanal— Its reabaorptlon — Its ultimate decomposition . . 168-181

CHAPTER IX.

FOBHATION OF SUUAR IN THE LIVEB.

Bxistenee of sngar In liver of all animals — Its percentage — Internal origin of
lirer-aogar — its prodoctton after death — Oljoogenlc matter of the liver — Its
properties and composition — Absorption of llrer-sngar hj hepatic veins —
Its acenmolation la the blood daring digestion— Its final decomposition and
disappearance ........ 182-189

CHAPTER X.

THE SPLEEN,

CapsnIe of Sple«n — Variations In sise of the organ — Its internal stmotare —
Halpighlan bodies of the spleen — Action of spleen on the blood — Effeat of
iU extirpation ........ 190-194

CHAPTER XI.

THE BLOOD.

Ran Olobdlbs of the blood— Their microscopic characters — Stmcture and com-
position— Variations in size in different auimals — White Qlobdlbs of the
blood— Independence of the two kinds of blood-globules — Plasma — Its com-
position— Fibrin — Albumen — Fattj matte ns— Saline ingredients — Extractive
matters — Coaoulatios or the Blood — Separation of clot and serum — Influ-
ences hastening or retarding coagulation — Coagulation not a commencement
of organiiation— Formation of buffjr coat — Entire quantitjr of blood lu bodf

196-213

CHAPTER XII.

BE8PIRATION.

Respiratory apparatus of aquatic and air-breathing animals — Structure of
Inngs in human Bnbject-^&espirstory movements of chest — Of glottis —
Changes in the a!r during respiration — Changes in the blood — Proportions
of oxygen aud oarbonio acid, in venous and arterial blood— Solution of gases
bj the blood-globules — Origin of carbonic acid in the blood— Its mode of
production — Qaantitj of carbonlo acid exhaled from the body — Variations
according to age, sex, temperature, &c. — Respiration by the skin 214-234

XIV

CONTENTS.

CHAPTER XIII.

ANIMAL BEAT.

PMS

SlandArtl ttrmptratarn of aniionU — Itovr miiiiitniiiri] — Pmriucliou of lit; at by
VegrUbU*— Moilo of gendTBtion of animal livst — Theory of oombasifon —
Objvoliona lo ibis theory— ^uoxSilatiua in vep^tablM during produi-tion of
heal — dauiittipa of oxygen And cnrlronh acid In animals do not correspond
wllh each other — Prmliiilifin of aoimtil best a local process — Duponiii on
lb« c1i«tnical pbenoniena of nntrition ..... 235-24S

CHAPTER XIV.

THE CIRCt'l^Tlf>S.

Circulatory spp&rstna of fleh — Of r»pill» — Of mammalians — Cnanw of blood
tlirou^'h tbe b^arl — Action of tsIti^i^ — Sounds of li'uart— MotHnietit*'— Ini-
puleu — Succvsfivu pubatlotM — Arlirriiil s>'8tffin — Mov«mvnt of blood Ilirougb
IbA orlitrlna — Atteriul pnlso — Artbrir\l prusinru — Rapidity of arterial cimula-
tion — The TAins— CaiMoa of movoinenl of l)loud in th» r(;!na — Rapidity of
T«nouit i^nrrxnt— 'Onpi Mary cin;iilntioii— l'h»Tionieri& nn<i cjiniins of i-ApiLInry
vlrvalation — Rapidity of entire oircnUtloo — Loo^lI rariatlona la diflpri'nt
part* ^<J-2SB

CHAPTER XV.

IMBIBITION AND EXHALATION. — TIIR LTMPIIATIC SYSTEM.

End«iinodlHanrl«xoinio)ilH — MorlouruxhitilllngtbeiD — Conditions Trbkh rei;ii>
UIp ilii'ir activity — Katiiro of tbo mtirabrane — Rxtpnt of contact — ConBtitn-
liiju of lliB Itiiuida— TeinpomturH— PrvMaurt)— NKtunt of vitduumuHli— lla
coo'iitiniis in th* living body — Itn rapidity — Pbenoroena of «n<io8moiis la
tho circulatiou— Tlia lyrophatioH— Tliuir origin— Confititiillou of tbw lymph
and chylfl — Their qoanlity— Liqoidfl secreted and reabHorhod In tirenty-/onr
lioon ......... 'J8a-^0&

CHAPTER XVI.

SECRETION.

Katnr* of s«orelion — Tarlations in actirtty— Macna — SebBci>aaA matter — Ita
varictin — Ferapiralinn — Struolore of pcrspirniory ^Innda — Compositioti nnd
quantity of the penpEmtlon — Us use in regulating lliirauiiual tvuiperaturu —
Tears — Uilk — iu acidiBcalign — Secretion of bile — Atiatoinioal peouliaiitles

30tJ'322

CONTENTS. XV

CHAPTER XTII.

EXCBBTION.

Natnra of excretion — Exorementitioiu ■obstanoeB — Effect of their retention —
Urea — Ita conroe — Conversion into c&rbon&te of ammonia— Dally qnantitjr
of area — Creatine — Creatinine — Orate of soda — Urates of potasM and ammo-
nia — General oharaoters of the nrlne — Its oompoaltion — Variationi — Aooi-
denul ingredlenii of the nrine— Acid and alkaline fermentstiont— Final
decompositiou of the urine ...... 323-346

SECTION II.
NEHVOUS SYSTEM.

CHAPTER I.

OENEBAL CHABACTEB AND FUHCTIONS OV THS NBBTOUS BTSTEH.

Natore of the fnnotlon performed bj nervona system — ^Two kinds of nerrona
tissae — Fibres of white sabsUnoe — Their minute itmctare — DIriaion and
inoecnUtion of nerves — Oray Bnbatance — Nervons system of radiata — Of
molinacs — Of artionlata — Of mammalia and human sabjeot — Structure of
enoephalon — Connections of its different parte .... 347-369

CHAPTER II.

or NE&rous ibkitabilitt, and its mode or action.

Irritability of mnscles— How exhibited — InSaences which exhaust and destroy
it — Nervous irritability — How exhibited — Continnee after death — Exhaosted
by repeated excitement — Inflnence of direct and inverse electrical carrents
— Nervotu irritability distinct from mosoalar irritability — Nature of the
a«TonB force — Its resemblauce to electricity — Differences between the two

37l>-38l

CHAPTER III.

THE SPINAL CORD.

Power of sensation — Power of motion— Distinct seat of sensation and motion
in nervous system — Sensibility and excitability — Distinct seat of sensibility
and excitability la spinal cord — Crossed action of spinal cord — Independent
and associated action of motor and sensitive filaments — Reflex action of
spinal cmd — How manifested during disease — Inflnence in health on
sphincters, voluntary mnscles, urinary bladder, &c. . . 382 — 400

iti

CON'TKNTS.

cuAPxnn IT.

THE BRAIir.

rAOE

Seat of Nenitibilitjr itml ^scitabilitj in diflVrBiil pRrU nf tha «oo«ph&1oii— Oiru-
toiy ^nngHfl — Optio th&lami — Corpora xtnatA — EI vm is pharos — Itemarkable
eaacB oflnjury of hemlBp!i*rea — tilTBctof llielr removal — Imperfect dovelop-
maiil in iilioW-^Axt'.'c cliiMri^n^Tlimiry of phwnoloij^ — Ci^rwhellnm — -KfFpct
of lU Injury or r«ujoral — Coiuparalive durolopmenL in Jiffurvtil ctsssoft^
Tnb«rculn(|aa(lrtgt>niina — Tulii.Tannu1ar»^Medul]«ob]ungnta— Thre« kintis
of reflex AOtlou In nerTgua B^stem ..... 401-429

CHAPTER V.

TBI! CttANIAL MERVKS.

Olfiftclorj nerves — Optic ner^e* — Auditorj n«rTi>a — ClsHslflcation of cranEal
norveB— Motor iierv9B~SenBiliv9 ncrvos — Motor oouli oooimuufG— PuthcU-
co«— Mnlor exlonma— Fifth pair— Its s«n8ll>ilUjp — Effect of division — Intln-
enon on nianticntion — Indnence on the or|^-nii of Ai^lit — Pacini nerve — Effect
of it,K pMralysiR— UlDssO'phnrjn^enl ncrvi-— E'nnumniiaiilric— lis diHtribniion
— Iiiflu>uni.>u on pbarynx nml (tuophngu* — On larvnx — On lungs — On RloiiiauU
and diRestiou— Spinal accessory nerve — Hypoglossal . . . 430-461

CHAPTER VI.

THE gPECIAL BKySKS.

General and Kppoial spn*it>ility — Sunttf of tniiRh in Iho *l(in and mneoas meni-
bmuee — Nature of tlw speclsl s*nie! — Tabtk — Ajiparatua of this SfUSf^Its
ooudllioiis — Its rosomblanoe to onlinnry naniialion— liijnry to Iho tasto in
paralysis of :h« farial nerro — Suem.— Arrangement of nerves in nasa! pas-
aagPM — ConiIiti-i>n« of tliis sonsi! — Uinliiiclion li.-twi'i'n odors nnJ irritating
vapors — SiouT — Strnclure of tlie oyrball — Spt-cisl sensibility of ttiti rtttina—
Action of thij Iwun^-Of the lrl» — CombiTind action of two i'y(«— Vivid nnlnrti
nftlio visual Impressions — [iKAimro — Auditory apparatus — Action of mem-
brAua tyiupnni — Of cluun of bonwt— Of ihoir musclus — Apprsuiation of the
dlreellon of sonnd — Analogies of heiariTig with ordinary •«naAtion 4(11^-^97

CHAPTER VII.

srereM op the great sYMt'.vTiteTic.

Ganglia of the (treat sympitlhotin — Distrlbtition of Ite Derv«8 — Sensibility and
excitability of sympalhi'lic — Slujigish aotlou of tliii nBr*«p — Itif1n«nc« ov«r
orfi;ana of aiwcial «iin!Hi — inevation of lemjieniture aftor division of sympa-
thetic— t'ontraction of pnpil following the emno operation — Roflvx ■olions
taking place ikruugh tlii» gruat syupalhetio .... 4CI6-S08

CONTENTS. XVii

SECTION III.
KEPEODUCTION.

CHAPTER I.

OM TBB NATUBS OF RGPRODDCTION, AND THE OBIOIN OF PLANTS AND

ANIMALS.

PAOB

ITitara Bod objects of the ftanction of r«pTOdD<.-tion — Uod« of its aocompltih-
inent — By generation from parents — Spontaneoas g«n«ration — Hietaken in-
stances of tliia mode of generation — Prodnetion of infosoria — Conditions of
their derelopment — Schaltse's experiment on generation of infusoria — Pro-
doction of animal and vegeuble parasites — EncTSted entosoa — Trichina
spiralis — Tenia — Cysticeraas — Production of tnnia from o/stioeroas — Of
cTSticeroas from eggs of tenia — Plants and animals always produced bj
generation from parents ....... 609-523

CHAPTER II.

ON 8EXVAL QENERATION AND THE HODS OF ITS ACOOHPLISHHENT.

Sexual apparatas of plants — Fecundation of the genn — Its derelopment into
a new plant — Sexual apparatas of animals — Ovaries and testicles — Dni-
seznal and bisuzaal species — Distinctive cliaracters of the two sexes 624-527

CHAPTER III.

ON TBS EOO, AND THE FEMALE GROANS OP GENERATION.

Siifl and appearance of the egg — Vitelline membrane — Vitellus — Oerminative
vesicle— Oerminative (pot — Ovaries— Graafian follicles — Oviducts — Female
generative organs of frog — Orar; and oviduct of fowl — Changes in the egg,
while passing through the oviduct — Complete fowl's egg — Utems and ova-
ries of the sow — Female generative apparatus of the human snbject — Fal
It^ian tubes — Body of the uterus — Cervix of the uterus . . 528-539

CHAPTER IT.

ON TBE SPERMATIC FLUID, AND THE MALE 0ROAN8 OF QENERATION.

The spermatozoa — Their varieties in different species— Their movement— For-
mation of spennatoEoa in the testicles — Accessory male organs of generation
— 'Bpididymis— Vas deferens — Veslcnin seminales — Prostate — Cowper's
glftnds — Function of spermatosoa — Physical conditions of fecundation 540-546

3tvin

CONTESTS.

CUAPTRR T.

ox PERIODICAL OVULATION, AND TUB rCMOTlON OP MENSTRUATIOS.

rAOR
PaaioiMCAi, OvtrLATioK— Pnt^xistsnce of e^B In tlie OT«ri« of all aniinali—
Tb«tr iDore&Bed duvvloi^ment at ike perioi) of pabertj' — Their Baccwslre
rlpenlusaudporlodiualdisohArge — Discbarge of uggs lndt>i>(indnntly of xcxuaI
lnt«rcoDrse — Itnplure of (IrAnflan fvllinlo. And expulsion of lli« eg^ — PUeuo-
laoiia of mtTnitlion— MK^K-riiiTATiOK — C>orr«HpciniIeiiCD of niKnatrual periods
nUI> pMtioiU of orulaliuu io tlia lownr aniitinls — Oiltaharas of egg daring
iD«n>traal period — Conditions of Ha luipregualiou, anor luaving iho ovary

&47-S53

CHAPTER VI.

ON TDK OORPUe LtTTBUM OF MENSTBUATCON AND PHliONANCy.

Cnit?Cii Lcmnrif or Mejijitrdat[ox — Dfiicharg« of blood into the ruptnr«d GraaBan
foLLlcle — Decoioriiallon of th« clot, and hvportroplij^ of tliti uviuliraiiv of tli«
veslulo — CorpUff lutfiam of moiiRtrnAtion, at tli« oiid of Ihree w«eka — Yellow
roloration of convolutitd wall — Corpus lut«)Uin of nnnKtruaUon at tlio end
of fonrvMiks — ShrlrcIIing and condensation of Ita tliaiies — Itaoonditiun at
thivmd of iiin«ir«*kN-^lts Jihal atrojib/ and dimajipciu'aDco— CaayiiH Lotkdii
Of Pbbohancv — Its continued development aflar Iho third w «elc -^Appear ail V9
at Ifac end of avaond moutb — Of fourth month — At the liirmiuation of preg-
nancT — Its atrnphy and dEsapprtaraneo after doliTcry — Distinulirocliaracliira
of 4X)rpo/a Uilea of menstruation and prcgnauoy . , , ^(30-569

CHAPTER VII.

ON THE DEVCl-OPMEM Of THE IMFKEGNATEU EGO.

Segmentation of tho vltollne — Formation of blastodermic moiubrsno — Two
layers of blaBlodermio membrane — Tliickening of external layer — Formation
of priiuit!v« Iraee — ^Doriial platen— Alidominal platon— Clo«nr« ofdoranl and
abdominol plat«s ou tlie uiedian lin« — FuruiutioD of intestine— Of muutli
and auus — Of organs of locomotion — Continued dwelopmonf of organs, after
loBving tho vgg ...,,,.. S74-5T1>

CHAPTER Vni.

TUB UMUILICAL VESICLE.

Separation of vitelltne lao into two cnrllies— Closttro of abdominal walls, and
formation of amlnlical TeiielK in fiab — Mode of its disappearance aftrr hatch*
Ing— Umbilical rpnicl* iii haman emhryo— rormalion and growth of pediels
— DUappuarnnce of uaibjlliial viMlelv during ruibryoulc life 6l^0-5S2

CONTESTS. xix

CHAPTER IX.

AMNION AND ALLANTOIfr— DETELOPIfENT OF THE CHICK.

PASI

Necesiit7 for aocnioiy organs in the deTfllopment of birds &nd qaadnip«ds —
Formation of ftmniotio folds— Their union and adhesion— Growth of allantoia
from lower pwi of Intestine — Its Tasoalarit/ — Allantoia In the egg of the
fowl — Respiration of the egg — Absorption of caloareooa matter from the
shell — Ossiflcation of skeleton — Fraotnre of egg-shell — Casting off of amnion
and allantoia ........ 683-691

CHAPTER X.

DETELOPHENT 07 THE EOO IN THE HUAUN SPECIES — FOBHATION 07 THE

CHORION.

Conrersion of allantoia into ehorion — Snbseqaent ohanges of the chorion —
Its Tillofllties — Formation of bloodresscls in villofiitles — Action of villi of
chorion in providing for nntritlon of ftstas — Proofs that the ohoriou is formed
from the allantoia — Partial disappearance of villositiea of chorion, and
changes in Its external surface ...... 692-697

CHAPTER XI.

DEVELOPMENT OF m'EBINE MUCOUS HEHBBAXE — FOBftlATION OF THE

DECIDUA.

Stracture of uterine mncoas membrane — Uterine tubules — Thickening of ate-
rine mucous membrane after Impregnation — Deoidna vera — Entrance of egg
Into atema — Decldoa reflexa— Incloeure of egg bj decidua reflexa — Union
of chorion with decidoa — Changes in the relative development of different
portions of chorion and decidua ..... 698-604

CHAPTER XII.

THE PLACENTA.

Nonrishment of fcetus by maternal and foetal vessels — Arrangement of the
vascular membranes In different species of animals — Membranes of foetal
pig — Cotyledon of cow's uterus — Development of foetal tufts in human pla-
centa— Development of uterine sinuses — Relation of fcet&l and maternal
btoodvedaels In the placenta— .Prools that the maternal sinuses extend
through the whole thickness of the plaoenta — Absorption and exhalation
bj the placental vessels ...... 605-613

XX CONTENTS.

CHAPTER XIII.

DISCHABOB OF THE OVUM, AND INVOLUTION Or THE UTERUS.

PAOI

EnlargemeDt of amniotio carltf — Contact of amnion and chorion — Amniotic
flaid — Uovementa of fistiu — Union of deoidna rsra and refieza — Expnlsion
of the OTura and diechar^e of decidaal membrane — Separation of the pla-
centa— Formation of new mncona membrane nndemeath the old decidoa—
Fatt^ degeneration and reconstrootlon of mnsontar walla of ntenu 614-620

CHAPTER XIV.

DEVELOPMENT OF THE EMBBYO — NBBV0U8 BYBTEH, 0B0AN8 OF SENSE,
SKELETON AND LIMBS.

Formation of spinal cord and cerebro-spinal axis — Three cerebral Teslclea—
Hemispheres — Optto thalaml — Taberonla qsadrigemina — Cerebellnm — Ue-
dnlla oblongata— Bye — PapiIUr; membrane — Skeleton — Chorda dorsalis —
Bodies of the vertebra — Lamina and ribs — Spina bifida — Anterior and poa-
terior extremities— Tail — Integnment — Hair — Vemiz oaaeosa — Exfoliation
of epidermis ........ 621-627

CHAPTER XV.

DEVELOPMENT OF THE ALIMENTARY CANAL AND ITS APPENDAGES.

Formation of intestine — Stomach — Daodennm — Conrolatlons of Intestine —
Large and smalt tnteaUne — Capnt ccli and appendix Tennlformis — Umbl-
Uoal hernia — Formation of nrinarj bladder — Urachns — Tesioo-rectal septum
—Ferinenm—UTer— Secretion of bil»— Oaatrlo Juice— Meconium — OI;oo-
genlc function of liver — Diabetes of fcetns — Pharynx and oosophagns — IHa-
I^ragm — Diaphragmatic hernia — Heart and pericardium — Ectopia cordis —
Development of the face ...... 628-637

CHAPTER XVI.

DEVELOPMENT OF THE KIDNEYS, WOLFFIAN BODIES, AND INTERNAL OROANS

OF OENERATION.

Wolffian bodies — Their striictnre — First appearance of kidneys — Growth of
kidneys, and atrophy of Wollflan bodies — Testicles and ovaries— Descent of
the testicles — Tunica vaginalis testis — Congenital ingainal hernia— Descent
of the ovaries — Development of the ntema .... 638-647

CONTESTS. XXI

CHAPTER XVII.

DBVELOPHENT OF THE CIRCUI.ATOBT APPARATUS.

PAOB

Pint, m vttfllline ciroalatioa — Are« TusonloBft— SiniiB tennlnaUB — YitalUne
oircnUtlon of fiali — Arruigement of BrteriM snd veins In hod^ of fliBtiia —
Second, or pUoental olrcaUtion— Omphalo-mesentorlc arteries and vein —
Clrcnlatioa of the ambilloal Tssicle — Of the alUntois and placenta— Umbi-
lical arteries and veinB — Third, or adnlt olronlatlon — Portal and pnlmonary
sjsteins — Development of the arterial sjBtem — Development of the venons
STStem — Changes in the hepatic olrcolation — Portal vein — Umbilical vein
— Dnotos venosna — Changes In the oordlao oiroalatlon — Division of heart
Into right and left cavities — Aorta and polmonar^ arter; — Dnctns arteriosus
— Foramen ovale and Enstachian valve— Changes In olrcnlation at the pe-
riod of birth 648-669

CHAPTER XVIII.

DEVELOPMENT OF THE BODT AFTER BIBTH.

Condition of fffitns at birth — Gradual establishment of respiratlcoi — Inactlvltj
of the animal fanctiona — Preponderance of refiex aotious in the oervons
B78tem— Peonliarities in the action of dmgs on inbnt — Difference In relative
sise of organs. In Infant and adnlt — Withering and separation of amblllcal
cord — ExG[^iatIon of epidermis — First and second seta of teeth — Snbseqaent
changes in oeseoTis, mnacnlar and tegnmentary sjetems, and general devel-
<^ment of the bod^ ....... 670-673

LIST OF ILLUSTRATIONS,

ALL OF WHICH HATE BBE^T PHBPARED PROM ORIOIIfAL DBAWINOS, WITH TBS
EZCBPTIOH OF TEK, CBEDITED TO THEIB AUTHORITIES.

FIO.

1. Fibala tied tn a knot, after maceration in a dilate auid

2. Qrains of potato atarch .

3. Starch grains of Bermada arrowroot

4. Starch grains of wheat floar
6. Starch grains of Indian com

6. Starch grains from wall of lateral ventricle

7. Stearlne ....

8. Oteaginoos principles of hnmsn fat

9. Human adipose tissne

10. Chyle

11. OIobnleB of coir'a milk

12. Cells of costal cartilages

13. Hepatic eeUs

14. Urinlferotts tnbnles of dog
16. Unscnlar fibres of human ntems

16. Alimentary canal of fowl

17. Compound stomach of oz

18. Haman alimentary canal

19. Sknll of rattlesnake . . From

20. Skall of polar bear

21. Bknll of the horse

22. Molar tooth of the horse

23. Human teeth — upper Jaw

24. Buccal and glandular epithelium deposited from sallra
26. Qastrio mucous membrane, viewed from above

26. Oastric mucous membrane, in vertical section

27. Hucoos membrane of pig's stomach

28. Qaatric tubnles from pig's stomach, pyloric portion

29. Qaetrio tubnles from pig's stomach, cardiac portion

30. Confervoid vegetable, growing in gastric Jnlce .

31. Follicles of Lieberkahn ....

32. Brunuer's duodenal glands • .

33. Contents of stomach, during digestion of meat .

34. From duodenum of dog, during digestion of meat
36. From middle of smalt intestine .

From Rymer Jones
Aohille Richard

FAOB

69
64
64
65
dS
66
71
72
74
74
76
76
76
76
77
101,

loa

103
106
]06
106
106
107
108
117
117
117
« 118
118
124
135
136
142
142
143

XXIV

LIST OF ILLU8TBAT10SS.

Tia.

36. From l&at qaarter of amaU intestiDe

37. One ot the Bloied folIiolM of Pojrer's patches

38. Olandnlia agtniaata ....

39. SxtramitT' of intestinal villas

40. Panisia's experiment on absorption by bloodvessels

41. Chyle, from oommenoement of thoracic duct

42. I^cteals, thoracic dact, &o.

43. Lacteals and lymphatics ....

44. Intestinal epithelinm. In Interrals of digestion .

45. Intestinal epithelinm, daring digestion .

46. Cholesterin .....

47. Ox-bile, oiyeUllIsed ....

48. Qlyko-cholate of soda from ox-bile

49. Olyko-oholate and tanro-cholate of soda, from ox-bile

50. Dog's bile, orystalliud ....

61. Haman bile, showing resinous matters .

62. Crystalline and resinoas biliary snbstanoes, from clog's Intestine

63. Duodenal fistula .....

64. Haman blood-glob ales ....

65. The same, seen oat of focus

66. The same, seen within the focas .

67. The same, adhering together in rows

68. The same, swollen by addition of water .

69. The same, Bhrirelled by evaporation

60. Blood-globnles of frog ....

61. While globules of the blood

62. Coagalated flbriu .....

63. Coagalated blood .....
64'. Coagalated blood, after separation of clot and sernm

65. Recent coagalnm .....

66. Coagalated blood, clot buffed and cupped

67. Head and gills of menobranchua .

68. Lang of frog .....

69. Homan larynx, trachea, bronchi, and langs

70. Single lobule of haman tang

71. Diagram illustrating the respiratory movements

72. Small bronchial tube ....

73. Haman larynx, with glottis closed

74. The same, with glottis open
7A. Human larynx — posterior view

76. Clrcnlation of flah ....

77. Clrcnlation of reptiles ....

78. Circalation of mammalians

79. Human heart, anturior view

80. Human heart, poaterior view

81. Right auricle and ventricle, tricuspid valve opeu, arterial valves closed

82. Right aaricle and ventricle, tricua^d valve closed, arterial valves open

83. Course of blood throagh the heart . . . . .

84. Illnstrating production of valvular sounds . , . .
66- Heart of frog, in relaxation ......

paoa
143
146
US
140
148
160
161
153
169
16S
160
161
161
162
165
166
172
173
196
196
197
197
199
199
202
203
206
208
209
212
212
216
216
217
217
219
221
222
232
223
247
248
249
250
250
250
251
262
256
258

LIST OF ILLUSTRATIONS.

zxr

no.

rAom

86. Heart of frog, in oontnotion .....

258

87. SLiuple Eaop«il fibres

258

88. Bullock's h»firt, showing Hnperflcial mnsonl&r fibres

259

89. Left Teiitri<rlfl of ballock'a heart, showiog deep flbrei

269

90. Diagmm of oiroaUr fibres of the heart .

260

91. Coover^ng fibres of the apex of the heart

260

92. Arterf in pulsation ....

265

93. Carres of the arterial polsatioD

267

94. Volkmann's apparatoa . . . . >;

. 271

96. The same .....

271

96. Vein, with Talrea open ....

■

275

97. Vein, with valres closed

275

98. Small arterj, with capillary bianvfaefl .

. 277

99. Caplllar7 network ....

278

100. Capillary circnlation ....

279

101. Diagram of the ciroolation

287

102. Follioles of a compound mnooas glandule . From Kblliker 809

103. Meibomian glands .... From Ladovlc 311

104. Perspiratorj gland . . . From Todd and Bowman 312

105. Glandalar stractore of mamma ....

315

106. Coloatmm oorpnsoles ....

316

107. MUk-globulea ....

317

408. Division of poil&l vein iu liver

320

109. Lobule or liver .....

. 821

110. Hepatic oells .....

322

111. Urea .... From Lehmann (Fnnke's Atlas) 326

112. Creatine .... From Lehmaon (Funke's Atlaa) 328

lis. Creatinine . . . From Lehmano (Foake's Atlas) 329

114. Urate of soda .......

. 330

llfi. Urio aold

. 336

116. Oxalate of lime .

. 342

'117. Phosphate of magsesla and ammcmta

344

118. NerrODB filaments, from brain .

3SI

119. Nervoos filaments, from sciatic nerre

. 362

120. BiTlsioa of a nerre

353

121. InoBoalation of nerves .

. 354

122. Nerve cells

354

123. Nervoaa system of starfish

355

124. Nervous sfstem of spljsia

367

12S. NervoQS system of oentipede

. 398

126. Cerebro-spinal ajstem of man .

. 361

127. Spinal cord

362

128. Brain of aUlgator

364

129. Brain of rabbit ....

365

130. Medalla oblongata of hnman brain

. 366

131. Diagram of boman brain

368

132. Experiment showing irritability of muscles

371

133. Experiment showing irritability of nerve

373

134. Action of direct and inverse onrrenta

376

135. Diagram of spinal oord and nerves

386

XXVI

LIST OF ILLUSTBATIOVS.

no.

136. Spltul oord In Tertloal section .

337. Bzperimeot, showing effect of poisons on neirea

138. Pigeon, after removal of the hemispheres

130. Aiteo children ....

140. Brain In sita ....

141. TransrerSR section of brain

142. Pigeon, after removal of the cerebellnm

143. Brain of htsltb/ pigeou In profile

144. Brain of operated pigeon in profile

145. Brain of heaUlij pig^eon, posterior Tiew

146. Brain of operated pigeon, postenor Tiew

147. Inferior sorfaoe of brain of ood .

148. Inferior snrfaoe of brain of fowl

149. Course of opticj nerres In man .

150. Distribntion of fifth nerve npon the face

151. Facial nerve ....

152. PneuniogastriQ nerve . . •

163. Diagnimof tongae

164. DisLribntloD of uurvee In the nasal passages

165. Vertical aeffition of e/eball
156. Dispersion of rava of light

167. Action of otTStalllne lens

168. Mjropia .....

159. Presb/opts ....

160. Vision at short distance

161. Vision at long distance .

162. Refraction of lateral rays

163. Skall, as seen hj left eye

164. Sknll, as seen bj right eye

165. Human auditor/ appairnLun

166. 3reat STrnpalheUc

167. Cat, an«r dJrision of sympathetic in the aeok

168. DifTereot kinds of infusoria

169. Uxpsrimenl on Bpontauuoua generation .

170. Trichina spiralis

171. Tvnia

172. Cjstioeroos, retracted .

173. Cystioerons, unfolded

174. Blossom of Convoltulus parparens

175. Siofjle articulation of Taala craasicollis

176. Human ovnm ....

177. Ilaman ovum, mptared by pressare

178. Female generative organs of frog

179. Matare frogs' egg*

180. Female generative organs of fowl

181. Fowl's egg ... .

182. Uteros and ovaries of the sow .

183. Generative organs of hnman female
164. Spermatosoa ....
185. Graafian follicle ....

From Sohaltie

raoB
393
396
40S
410
412
413
416
417
417
417
417
420
420
421
436
441
446
467
473
477
479
479
480
480
481
481
484
486
486
491
499
606
514
616
619
620
621
621
624
625
628
529
631
532
635
536
637
538
641
652

LIST OF ILLUSTBATIOHS.

xxvu

MO. FAOI

186. Ovary with Graaflan follicle raptured . . . . • . 552

187. Oraaftan folUole, raptarad and filled with blood . .661

188. Corpus luteam, three weeks after menstraation . . 562

189. Corpus lateum, four weeks after menatrnatioB . . . 663

190. Corpus iQteum, otne weeks after menHtmation . . . 663

191. Corpus tuteum of pregoancy, at end of second month . . 666

192. Corpus lateum of pregnancy, at end of fourth month . . 666

193. Corpus Inteum of pregnancj, at term ..... 667

194. Segmentation of the Titellns . . . . . . 671 -

195. Impregnated egg, showing embryonfo spot .... 674

196. Impregnated egg, showing two layers of blastodermio memlimn« . 676

197. Impregnated egg, farther advanced ..... 676

198. Fk^'b egg, at an early period . . . . .676

199. Egg of frog, in process of development ..... 576

200. Bgg of frog, farther advanced . . . . .676

201. Tadpole, fnHy developed . ... . .677

202. Tadpole, changing into (nyg . . . . . .578

203. Perfect frog ........ 678

204. Egg of fish 580

205. Young fish, with umbilical vesicle . . . . .681

206. Human embryo, with umbilical vesicle .... 681

207. Fecundated egg, showing formation of amnion .... 684

208. Fecundated egg, showing commencement of allantols . . . 685

209. Fecundated egg, with allantois nearly complete . . . 685

210. Fecundated egg, with allantois fully formed . . .686

211. Egg of fowl, showing area vasoulosa ..... 687

212. Egg of fowl, showing allantois, amnion, &c. .... 588

213. Human ovam, showing formation of chorion .... 692

214. Hnman chorion ........ 694

216. Villoslty of chorioii ....... 696

216. Hnman ovam, at end of third month ..... 696

217. Uterine mnoons membrane ...... 699

218. Uterine tubules .599

219. Impregnated nterns, showing formation of decldua , . 601

220. Impregnated nterns, showing formation of deoidaa reflexa . . 601

221. Impregnated nterns, with decldua reflexa complete 601

222. Impregnated uterus, showing union of chorion and decldita . . 603

223. Pregnant uterua, showing formation of placenta . . . 604

224. Foetal pig, with membranes ...... 606

225. Cotyledon of cow's uterus . . . . . .606

226. Fteut tnft of hnman placenta ...... 609

227. Vertical seotion of placenta ...... 609

228. Haman ovum, at end of first month ..... 614

229. Hnman ovum, at end of third month ..... 616

230. Gravid human nterns and contents ..... 616

231. Unscalar fibres of unimpregnated ateras .... 619

232. Hnscttlar fibres of human nteras, ten days after parturition . . 619

233. Muscular fibres of hnman nteras, three weeks after parturition . 620

234. Formation of cerabro-npinal axis ..... 621
236. Formation of cereliro-^pinai axis ..... 622

XXVlll

LIST or ILLCSTBATI0N8.

Fia.

236. Foetal pig, showing bniin and spinal cord

237. Fcetal pig, showing brain and spinal oord

238. Head of fcetal pig ... .

239. Brain of adult pig ... .

240. Formation of alimentary canal .

241. Head of linman embryo, at twenty days

242. Head of haman embryo, at end of sixth week .

243. Head of human embryo, at end of second month

244. Foetal pig, showing Wolffian bodies

245. Foetal pig, showing first appearance of kidneys
24S. Internal oi^ans of generation

247. Internal oi^gans of generation

248. Formation of tunica vaginalis testis

249. Congenital inguinal hernia

250. Egg of fowl, showing area vaeoQlosa

251. Egg of flsh, showing vitelline clrcolatfoa

2fi2. Young embryo and its vessels . . .

263. Embryo and its vessels, farther advanced
2M. Arterial system, embryonic form

255. Arterial system, adnlt form . ,

256. Early condition of venoas system

257. Venoas system, farther advanced

253, Continued development of venous system

259. Adnlt condition of venous system

260. Early form of hepatic circnlation

261. Hepatic circulation farther advanced .

262. Hepatic circulation, during latter part of fcetal life

263. Adult form of hepatic circnlation

264. FceUl heart

265. Foetal heart

266. Fcetal heart

267. Fcetal heart

268. Heart of Infant .

269. Heart of homan fcetus, showing Eastachian valve

270. Circulation through the fceUI heart

271. Adult circulation through the heart

From Longet

PASB

622
623
623
623
629
635
636
636
638
640
640
642
643
644
649
649
650
651
653
653
666
656
656
657
698
659
659
660
661
661
661
662
662
664
665
668

HUMAN PHYSIOLOGY.

INTRODUCTION.

I. Physiologt is the study of the phenomena presented by
organized bodies, animal and vegetable.

These phenomena are different from those presented by inorganic
substances. They require, for their production, the existence of
peculiarly formed animal and vegetable organisms, as well as the
presence of various external conditions, such as warmth, light, air,
moisture, &c.

They are accordingly more complicated than the phenomena of
the inorganic world, and require for their study, not only a pre-
vious acquaintance with the laws of chemistry and physics, bat, in
addition, a careful examination of other characters which are peco-
liar to them.

These peculiar phenomena, by which we so readily distinguish
living organisms from inanimate substances, are called Vitalpheno-
mma, or the phenomena of Life. Physiology consequently includes
the study of all these phenomena, in whatever order or species of
organized body they may originate.

We find, however, upon examination, that there are certain
general characters by which the vital phenomena of vegetables re-
semble each other, and by which they are distinguished from the
vital phenomena of animals. Thus, vegetables absorb carbonic
acid, and exhale oxygen ; animals absorb oxygen, and exhale car-
bonic acid. Vegetables nourish themselves by the absorption of
unorganized liquids and gases, as water, ammonia, saline solutions,
&o. ; animals require for their support animal or vegetable sub-
stances as food, such as meat, fruits, milk, &c. Physiology, then,
3

INTRODUCTIOy.

is TiHtumlly tVivided into two parla, viz., Vegefjible Physiology, and
Animal Ptiyaiology.

Again, ihe different groups and specica of atiimaU, while ihey
resemble each other in their general characters, are dislinguishcti
by certain minor differences, botli nf structure and function, which
require a special study. Thus, the physiology of fishes is not
exactly the same with that of reptiles, nor the physiology of birds
with that of quadrupeds. Among the warm-blooded quadrupeds,
the carnivora absorb more oxygen, in proportion to the carbonic
acjd exhaled, than the herbivora. Among the herbivorous quad-
rupeds, the proccsjt of digestion is comparatively simple in the
horse, while it is complicated in the ox, and other ruminating ani-
mals. There is, therefore, a. special physioJogy for every distinct
species of animal.

Human Puvsioi.ogv treats of the vital phenomena of the human
species. It is more practically important than the physiology of
the lower animals, owing to its connection with humau pathology
and LherapeuLicfi. But it cannot be made the exclusive subject of
our study; for the specinl pliysiology of the human body canuot
be properly understood without a previous acquaintance with the
vital phenomena common to all animals, and to all vegetables;
beside which, there are many physiological questions that require
for their solution experiments and observations, which can only be
made upon the lower animals.

While the following treatise, therefore, has for its principal sub-
ject the study of Humito Physiology, this will be illustrated, when-
ever it may be required, by what we know in regard to the vital
phenomena of vegetables and of the lower animals.

H. Since Physiology is the study of the active phenomena of
living bodies, it requires a previous acquaintance with their struc-
ture, and with the substances of which they are composed; that is,
with their anatomy.

Anatomy, again, requires a previous acquaintance with inorganic
Bub^taucejj; since some of these inorganic sub:>tancos enter into the
composition of the body. Chloride of sodium, for example, water,
and phosphate of lime, are component parts of the animal frame,
and therefore require to be studtcl as such by the auatfjmisi.
Now those inorganic substances, when placed under the requisite
uxtortial conditiuus, present certain active phenomena, which are
characteristic of thorn, and by which they may be recognized.

INTRODUCTION.

Thus lime, dissolved in water, if brought into contact with car-
bonic acid, ahcFB its condition, and takes part in the formation of
nn insoluble substance, carbonate of lime, wliich ia thrown dowtr
as a deposit. A knowledge of such chemical reactions as these ia
necessary to the nn&tonitst, since it is by them that ho is enabled to
recognize the inorganic substances, forming a part of the animal
body.

It is important to observe, however, that a knowledge of these
reactions is necessary to the anatomist only in order to cnnble him
to judge of the presence or ab.secice of the inorganic substances to
which they belong. It is the object of the anatomist to make him-
self acquainted with every constituent part of the body. Those
parts, therefore, which cannot be recognized by their form and
texture, he dlstinguislics by their chemical reactions. But after-
ward, he has no occasion to decompose ilieni further, or to make
them enter into new combinations; for he only wishes to know
these substances as thetj exist in the body, and not as they may exist
under other conditioDS.

The unorganiz<;il substances which exist in the body as compo-
nent pnrts of its structure, such as chloride of sodium, water, phos-
phate of lime, &o, are called the proximate principles of tlie body.
Mingled together in certain proportions, they make np the aniiniil
Haids, and associated also in u solid fortn, they constitute the tissues
and organs, and in this way make up the entire frame.

Anatomy makes us acquaintc<) with all those component parts of
the body, both solid and tluid. ft teaches us the structure of the
body in a stale of rest ; that is, just as it would be after life had
suddenly ceased, and before putrefaction had begun. On the other
hand. Physiology is a description of the body in a state of activity.
It shows us its movements, its growth, its reproduction, and the
chemical changes which go on in its interior; and in order to com-
prehend these, we must know, beforehand, its entire mechanical,
tcxtural, and chemical structure.

It is evident, therefore, that the description of the proximate prin-
c^/a, or the chemical substances entering into the constitutiun of
the body, is, strictly speaking, a part of Anatomy. But there are
many reasons why this study is more conveniently pursued in con-
nection with Physiology ; for some of the proximate principles are
derived directly, as we shall hereafter show, from the external world,
and some are formed from the elenients of the food in the process
of digeatioD; while most of them undergo certain changes io the

INTRODUCTION.

interior of tlie body, which result in the formation of new sub-
stances; nil these active phenomena belonging neccHaurily to the
domain of I*hysioIogy.

The deacnptioD of the proximate prlociples of animals and vege-
tables will therefore be introduced into the following pages.

The description of the minute structures of the body, or Micro-
gcopie Anatomy^ is also so closely connected with some parts of Phy-
siology ns to make it convenient to speak of them together; and
this will accordingly be doue, whenever the oature of the subject
may make it desirable.

III. The study of Physiology, like that of nil the other natural
sciences, is a study of pheTiomena, and of pbeuomuna alont;. The
fissential nature of the vital processes, and their ultimate caoses,
are questions which are beyond the reach of the physiologist, and
cannot be determined by the means of investigation which arc at
his disposal.

Conaeqaently, all efforts to solve them will only serve to tnislead
the investigator, and to distract his attention from the real subject
of examination. Much time hns been losi^ for example, in discuss-
ing the probable reason why menstruation returns, in the human
female, at the end of every four weeks. But the observation of
ualure, which is our only means of scientific investigation, cannot
throw any light on this point, but only shows us the fact thai men-
struation does really reeur at the above periods, together with tho
phenomena which accompany it, and the conditions under which it
is hastened or retarded, and increased or diminished, in intensity,
duratioD, Itc. If we employ ourselves, consequently, in the discus-
sion of the reason above mentioned, wo shall only become involved
in a network of hypothetical surmises, which can never lead to any
definite result. Our lime, therefore, will be much more pro6tably
devoted to the stuOy of the above phenomena, which can bo learned
from nature, aud which constitute, afterward, a permanent acquisi-
tion. •

The physiologist, accordingly, confines himself strictly to the
study of the vital phenomena, their characters, their frequency,
their regularity or irregularity, aud the conditions under which
they originate.

When he has discovered that a certain phenomenon always takes
plaoe in the presence of certain conditions, he has established what
is called a general principle, or a Law of Physiology.

tyTRODUCTION^ ^ 8T

As, for example, vlien he bas ascertained that eensation and
motion occupy distinct situations in every part of the nervoud
system.

This "Law," however, it mast be reraerabered, is not a discovery
by itaelf, nor docs it give him any new infofTiiatioii, but is simply
the expression, in couvenient and comprehensive language, of the
facts with, which he was already previously acquainled. It is very
dangerous, therefore, to make tbesd laws or general prinoiplea the
subjects of our study instead of the vital phenomena, or to suppose
that ihoy have any value, except as the expression of previously
ascertained facta. Such a misconception wuuld lead to bad practi-
cal results. For if we were to observe a phenomenon in discord*
anco with a "law" or "principle," we might be led to neglect or
misinterpret the phenomenon, in order to preserve the law. But
this would be manifestly incorrect. For the law is not superior to
the pbenomenoD, bntf on the contrary, depends upon it, and derives
its whole authority from it. Such mistakes, however, have been
repeatedly made iu Physiolog}', and have frequently retarded its
advance.

IV, There ia only one means by which Physiology can be
studied: that is, the observation of nature. Jts phenomena cannot
be reasoned out by themselves, nor inferred, by logical sequence,
from any original principles, nor from any other set of pIienom,ena
whatever.

In Mathematics and Philosophy, on the other hand, certain truths
are taken for granted, or perceived by intuition, and the remainder
aflorward derived from them by a process of reasoning. But in
Physiology, as in all the other natural sciences, there is no such
starting |x>int, and it is impossible to judge of the character of a
phenomenon until after it hss been observed. Thus, the only way
to learn what action is exertetl by nitric iicid upon carbonate of
soda is to put the two substances together, and observe the changes
which take place; for there is nothing in the general characters of
these two substance:) which cuuld guide us in anticipating the result.

Neither can we infer the truths of Physiology from those of
Anatomy, nor the truths of one part of Physiology from those of
another part; but all must be ascertained directly and neparately
by observation.

For, although one department of natural science is almost always
a necessary preliminary to the study of another, yet the facts of

IirrRODDCTIOX.

the latter can Tiever be in the least degree inferred from Ifioae of the
former, hut must be studied hy thevxselve*.

Thus Oliemistry is essential to Anatomy, because certain sub-
stances, as we have already shown, belonging to Cheniislry, such
as chloride of sodium, occur as couslituuntii of tliu animal body.
Chemistry tenches ua the composition, reactions, mode of crystal-
lization, solubility, &e., of chloride of sodium; and if we did not
know these, we could not extract it, or recognize it when extracted
from the body. But, however well we might know the chemistry
of this substance, we could never, on that account, infer \\s presence
in the body or otherwise, nor in what quantities nor in what situa-
tions it would present itself. These focta must be nscertained for
themselves, by direct investigation, as a part of anatomy proper.

So, again, the structure of the bo<ly in a atate of rest, or its
anatumr, ia to be first understood; but its active phenomena or its
physiology must then be aaccrtaincd by direct observation and
experiment. The most intimate knowledge of the minute struc-
ture of the muscular aud nervous libres could not teach us any-
thing uf their phyatology. It ia ouly by cxperitncnt that we
ascertain one of them to be contractile, the other sensitive.

Many of the phenomena of life are chemical in their chaTficler,
and it is requisite, therefore, that the physiologist know the ordi-
nary chemical properties of the substances composing the animal
frame. Uut no amount of previous chemical knowledge will
enablo him to foretell the reactions of any chemical substance in
Iha interior of the body; because the peculiar conditions under
which it is there placed modify these reactions, as an elevation or
depression of Icinpernture, or other e.\.ternal circumstance, might
modify them outside the body.

We must not, therefore, attempt to deduce the chemical pbe-
iiomcna of physiology from any previously established facts, since
these are no safe guide; but must study them by themselves, and
depend for our knowledge of tbem upon direct observation alone.

V. By the terra Yilol phenomena^ we mean those phenomena
which nre manifested in the living body, and which are character-
iatio of its functions.

Some of these phenomena are physical or mechanical in their

character; as, for example, the play of the articulating surface*

upon each other, the balancing of the spinal column with its ap*

ipendages, the action of the elastic ligaments. Nevertheless, these

INTRODUCTION.

phenomena, though strictly physiea! in character, are ollen entirely
peouliur nnd different from those seen elsewhere, becauee the mc-
cbanism of their produciioQ is peculiar in its details. Thus the
humon voice and itu modulations are produced in the larynx, in
accordance with the general physical laws of sound; but the
arrangement of the clnstio and movable vocnl (jhords, and their
relations with the columns of air above and below, the moiat and
flexible mucous meinbraue, and the contractile mu&cles outside, are
of such a special character that the entire apparatus, as well as the
aounda producc<l by it, h peculiar; and ita action cannot be properly
compared with that of any other known musical instrument.

Id the same manner, the raovementa of the heart are so compli-
cated and remarkable that they cuntiot be comprehended, oven by
one who is acquainted with the anatomy of the organ, without a
direct examination. This is not because there is anything esseo-
llally obscure or mysterious in their nature, for they are purely
mechanical in character ; but because their conditions are so pecu-
liar, owing to the tortuous course of the muscular fibr&i, tlietr
arrangement in interlacing layers, their attachments nnd relations,
that their combined action produces an eflcct altogether peculiar,
and one which is not similar to anything outside the living body.

A very large and important class of the vital phenomena ore
those of a chemical character. It ia one of the characteristics of
living bodies that a succession of chemical actions, combinations
and decern position;*, is constantly going on in their interior. It is
one of the necessary conditions of the existence of every animal
and every vegetable, that it should constantly absorb various sub-
staooes from without, which undergo different chemical alterations
ID its interior, and .ire finally discharged from it under other forms.
If these changes bo prevented from taking place, life is immediately
extinguished. Thus animals constantly absorb, on the one hand,
water, o.xygen, salts, albumen, oil, sugar, &c^ and give up, on the
other hand, to the surrounding media, carbonic acid, water, ammonia,
ureu, and the like; while between these two extreme points, of ab*
sorption and c.thnlation, iherc take place a multitude of diOerent
irnnsfurmalions which are essential to the continuance of life.

Some of these chemical actions are the same with those which
are seen outside the body; but most of them are entirely peculiar,
and do not take place, and cannot be made to take place, anywhere
else. This, again, is not becuuso there is anything particula
mysterious or extraordinary in their naturt^ but because tl

IVTEODCCTIOy.

rlitions necessary for their accomplishment exist in tlie body, and
do not exist elsewhere. All chemical phenomena are liable to be
modified by surrounding conditions. Many reactions, for example,
which will take plac« at a high temperature, will not tike place at
a low temperature, and ri'ce versd. Some will take place in the light,
but not in the' dark ; others will take place in the dark, but not in
the light. If a hot concentrated solution of sulphate of soda be
allowed to cool in contact with the atmosphere, it crystallizes;
covered with a film of oil, it remains iluid. Beoausa a chemical
reaction, therefore, takes place andcr one set of conditions, wc can-
not be at all sure that it will also take place under others, which
are dift'erent.

The chemical conditions of the living body are exceedingly com-
plicated. In the anlmul solids and fluids there are many subsuinoea
mingled together in varying quantities, which modify or ititcrfero
with each other's reactions. New substances are constantly eniering
by absorption, and old ones leaving by exhalation; while the circQ-
lating 6uids are constantly passing from one part of the body to
AQOthcf) and coming in contact with different organs of diHcrent
textore and composition. All these conditions are peculiar, and so
modify the chemical actions taking place in the body, that they are
unlike those met with anywhere else.

If starch and iodine be mingled together in a watery solution,
they unite with each other, and strike a deep opaque blue color!
but if they be mingled in the blood, no such reaction takes place,
because it is prevented by the presence of certain organic substances
which interfere with it.

If dead animal matter be ox]>{Mted to warmth, air, and moisture,
it putrefies; but it' introduced into the living stomach, even after
putrefaction has commenced, this process is arrested, because the
fluids of the stomach cause the animal substance to undergo a
peculiar transformation (digestion), after which the bloodvessels
immwliatcly remove it by absorption. Thero are also certain sub-
stances which make their appearance in the living body, both of
animals and vegetables, and which cannot be formed elsewhere;
such as Hbrin, albumen, casein, pneumic acid, the biliary salts, mor-
phine, &e. These substances cannot be manufactured artilicitdly,
simply because the necessary conditions cannot bo imitated. They
require for their production the presence of a living organism.

The chemical phenomena of the living body arc, therefore, not
different in their nature from any other chemical phenomena; bat

INTBODDCTIOW. 41

they are different in their conditions nod in their resalts, and are
consequently pecaliar and characteristic.

Another set of vital phenomena are those which are manifested
in the processes of reproduction and development. They are again
entirely distinct from any phenomena which are exhibited by
matter not endowed with life. An inorganic substance, even when
it has a definite form, as, for example, a crystal of fluor spar, has
no particular relation to any similar form which has preceded, or
any other which is to follow it. On the other hand, every animal
and every vegetable owes its origin to preceding animals or vege-
tables of the same kind; and the manner in which this production
takes place, and the different forms through which the new body
successively passes in the course of its development, constitute the
phenomena of reproduction. These phenomena are mostly depend-
ent on the chemical processes of nutrition and growth, which take
place in a particular direction and in a particular manner ; but their
results, viz., the production of a connected series of different forms,
constitute a separate class of phenomena, which cannot be explained
in any manner by the preceding, and require, therefore, to be studied
by themselves.

Another set of vital phenomena are those which belong to the
nervous system. These, like the processes of reprodoction and
development, depend on the chemical changes of nutrition and
growth. That is to say, if the nutritive processes did not go on in
a healthy manner, and maintain the nervous system in a healthy
condition, the peculiar phenomena which are characteristic of it
could not take place. The nutritive processes are necessary condi-
tions of the nervous phenomena. But there is no other connection
between them; and the nervous phenomena themselves are distinct
from all others, both in their nature and in the mode in which they
are to be studied.

A troublesome confusion might arise if we were to neglect the
distinction that really exists between these different sets of phe-
nomena, and confound them together under the expectation of
thereby simplifying our studies. Since this can only be done by
overlooking real points of difference, its effect will merely be to
introduce erroneous ideas and suggest unfounded similarities, and
will therefore inevitably retard our progress instead of advancing it.

It has been sometimes maintained, for example, that all the vital
phenomena, those of the nervous system included, are to be reduced
to the chemical changes of nutrition, and that these again are to be

TNTRODCCTIOy.

regurded ns not at all diftbrent in any respect from tbe ordinary
chemical cliangea taking place outside the body. Thia, however,
is not only erroneous in theory, but conduces nUo to a vicious
mode of study. For it draws away our attention from the phe-
nomena themselves and their real characteristicfs and leads us to
deduce one set of phenomena from what wo know of another; a
method which wc have already shown to be unsafe and pernicioas.
It has alfio beeu asserted that the plienomeua of the uervous
system are identical with those of electricity; for no other reason
than that there exist between them certain general rcBcmblancea.
But when we examine the phenomena in detail, wc find that, beside
the.se gencnil resemblances, there are many essenti:!! points of difl*
similarity, which must be 8Up}>ressed and kept out uf sight in order
to sustain the idea of the assnmed identity. This assumption is
consequently a forced and unnaturnl one, and the simplicity which
it was iutended to introduce into our physiological iheoriea is
imaginary and deceptive, and is attained only by sacriQcing a part
of those scientific truths, wbieh are alone the real object of our
study. Wc -should avoid, therefore, mnking any such unfounded
comparisons; for the theoretical simplicity which result? from them
do€8 not compensate for the loss ofesseotial acientiCic details.

VI. The study of Physiology is naturally divided into three dis-
tinct Sections: —

The first of these includes everything which relates to the Nutri-
tion of the body in its widest sense. It comprises the history of
the proximate principles, their source, the manner of their produc-
tion, the proportions in which they exist in diflerent kinds of food
and drink, the processes of rligestton and absorption, and the con-
stitution of tbe circulating fluids; then tbe physical phenomena of
the circulntion and tbe forces by which it is accomplished; the
changes which tlie blood undergoes in diflTcrctit parts of the body;
all the phenomena, both physical and chemical, of respiration; those
of secretion and excretion, and the character and clestination of the
secreted and excreted fluids. All these processes have reference to
a common object, viz., the preservation of the internal structure and
healthy organiisation of the individual. With certain modifications,
they take place in vegetables as well as in animals, and aro conse-
quently known by the name of the ve'jdative/tnKdons.

Tlie Second Section, in tbe natural order of study, is devoted to
tbe phenomena of tbe Nervol'S System. These phenomena are

INTBODDCTIOy. 48

QOt exhibited by vegetables, but belong exclusivelj to animal or-
ganizations. They bring the animal body into relation with the
externa] world, and preserve it from external dangers, by means of
sensation, movement, consciousness, and volition. They are more
particularly distinguished by the name of the animal functums.

Lastly comes the study of the entire process of Reproduction.
Its phenomena, again, with certain modifications, are met with in
both animals and vegetables; and might, therefore, with some pro-
priety, be included under the head of vegetative functions. But
their distinguishing peculiarity is, that they have for their object
the production of new organisms, which take the place of the old
and remain after they have disappeared. These phenomena do
not, therefore, relate to the preservation of the individual, but to
that of the species; and any study which concerns the species
comes properly after we have finished everything relating to the
individual.

SECTION I.
NUTRITION.

CHAPTEE I.

PROXIMATE PRINCIPLES IN GENERAL.

The study of Nuthition begins naturally with that of the proxi-
mate principle, or the aubstaaces entering into the composition of
the different parts of the body, and the different kinds of food. In
examining the body, the anatomist finds that it is composed, first,
of variona parts, which are easily recognized by the eye, and which
occupy distinct situations. In the case of the human body, for
example, a division is easily made of the entire frame into the
head, neck, trunk, and extremities. Each of these regions, again,
is found, on examination, to contain several distinct parts, or
" organs," wbich require to be separated from each other by dissec-
tion, and which are distinguished by their form, color, texture, and
consistency. In a single limb, for example, every bone and every
muscle constitutes a distinct organ. In the trunk, we have the
heart, the lungs, the liver, spleen, kidneys, spinal cord, &c., each of
which is also a distinct organ. When a number of organs, differing
in size and form, but similar in texture, are found scattered through-
out the entire frame, or a large portion of it, they form a connected
set or order of parts, which is called a " system." Thua, all the
muscles taken together constitute the muscular system; all the
bones, the osseous system ; all the arteries, the arterial system.
Several entirely different organs may also be connected with each
other, so that their associated actions tend to accomplish a single
object, and they then form an " apparatus." Thus the heart, arte*
ries, capillaries, and veins, together, form the circalatory apparattu;
the stomach, liver, pancreas, intestine, &c., the digestive apparatr
Every organ, again, on microscopic examination, is seen to be m

46 PBOXIHATE PRINCIPLES IN' QKNKBAL.

up of minute bodies, of deBnite size and figure, which are so small
as to be invisible to the naked eye, and which, after separation
from each other, cannot be further subdivided without destroying
their organization. They are, therefore, called "anatomical ele-
ments." Thus, in the liver, there are hepatic cells, capillary blood-
vessels, the fibres of Glisson's capsule, and the ultimate filaments
of the hepatic nerves. Lastly, two or more kinds of anatomical
elements, interwoven with each other in a particular manner, form
a "tissue." Adipose vesicles, with capillaries and nerve tubes,
form adipose tissue. White fibres and elastic fibres, with capillaries
and nerve tubes, form areolar tissue. Thus the solid parts of the
entire body are made up of anatomical elements, tissues, organs,
systems, and apparatuses. Every organized frame, and even every
apparatus, every organ, and every tissue, is made up of difierent
parts, variously interwoven and connected with each other, and it
is this character which constitutes its organization.

But beside the above solid forms, there are also certain fluids,
which are constantly present in various partsofthe body, and which,
from their peculiar constitution, are termed "animal fluids." These
fluids are just as much an essential part of the body as the solids.
The blood and the lymph, for example, the pericardial and synovial
fluids, the saliva, which always exists more or less abundantly in
the ducts of the parotid gland, the bile in the biliary ducts and the
gall-bladder : all these go to make up the entire body, and are quite
as necessary to its structure as the muscles or the nerves. Now, if
these fluids be examined, they are found to be made ap of many
different substances, which are mingled together in certain propor-
tions; these proportions being constantly maintained at or about
the same standard by the natural processes of nutrition. Such a
fluid is termed an organized fluid. It is organized by virtue of the
numerous ingredients which enter into its composition, and the
regular proportions in which these ingredients are maintained.
Thus, in the plasma of the blood, we have albumen, fibrin, water,
chlorides, carbonates, phosphates, &c. In the urine, we find water,
urea, urate of soda, creatine, creatinine, coloring matter, suits, &o.
These substances, which are mingled together so as to make up, in
each instance, by their intimate union, a homogeneous liquid, are
called the proximate principles of the animal fluid.

In the solids, furthermore, even in those parts which are appa-
rently homogeneous, there is the same mixture of different ingre-
dients. In the hard substance of bone, for example, there is, first.

PBOXIUATB PRItrciPLEg IN GKNKRAL.

water, which may be expoUed by evaporatioa ; second, phosphate
and carbonatti of lime, wbicb may bo extracted by Ibe proper sol-
vents; third, a peculiar animal matter, willi which these calcareous
salts are in union; and foiirtli, various other saline substances, in
special proportions. In the muscular tissue, there is chloride of
poiasaium, Inetic acid, water, salw, albumen, and an animal matter
termed musculine. The dil^erence in consistency betweou the solids
and Huidtidces not, therefure, indicate any radical diflerenQe in their
constitution. 13uih ore equally made up of proximate principles,
mingled together in various proportions.

It ia important to understand, however, exactly what arc proxi-
mate principles, and what are not such; for since these principles
are extracted from the animal sulidH nnc] fluids, and sepnrated from
each other by the help of certain chemical manipulations, such as
evaporation, solution, crystallization, and the like, it might be sup-
posed that every substance which could be extracted from an orgao-
izod solid or (luid, by chemical means, should be considered ns a
proximate principle. That, liowever, is not the case. A proximate
principle is properly defined to be ani/ subsiance, uhciher simple or
compound, chemically speaking, which txi$tt, urvUr its own form, in Ute
animal toUd or fluid, and which can be extracted by means which do
not alter or destroy its chemical properties. Phosphate of lime, for
example, is a proximate principle of bone, hut phosphoric acid is
not so, since it does not exist as such in the bony tissue, but is
produced only by the decompoaition of the calcareuua salt: still
\iim ph<wphorus, wliich is obtained only by the decompo&itioa of
the phosphoric acid.

Proximate principles may, in fact^be said to exist in all solids or
fluids of mixefJ composition, and may be extracted from them by
the same moans as iu the case of the animal tissues or secretions.
Thus, in a watery solution of sugar, we have two proximate prin-
ciples, viz: first, the water, and second, the sugar. The water may
be separated by evaporation and condensation, af\er which the
sugar remains behind, in a crystalline form. These two substances
have, therefore, been simply separated from each other by the [iro-
cess of evaporation. They have aot been decomposed, nor their
chemical properties altered. On the other hand, the oxygon and
hydrogen of ilic water were not proximate principles of the original
solution, and did not exist in it under their own formA, but only in
a statoof uombinatiou; forming, in this cundttion, a fluid subsiance
(water), endowed with sensible properties entirely di&reut from

PROXfHATB PRiyoiPLBS ty OSKERAt..

tlieira. If wo wish to aacertnin, accordingly, llie nature and proper-
ties of a saccharine solution, it will afford us but little satisfaction to
extract lis ultimate chemical elements; for its nature and properties
depend not so uiucli ou the presence in it of the ultimate elements,
oxygen, hydrogen, and carbon, as on the particninr forms of com-
bination, viz., water and sugar, under which they are prej*ent.

It is very essential, therefore, that in extracting the proximate
principles from the animal body, only such means should be adopted
as will isolate the substances already existing in the tissues and
fluids, without decomposing them, or altering thetr nature. A
neglect of this rule has been productive of much injury in the pur-
suit of organic chemistry; for chemists, in subjecting the animal
tissues to the action of acids and alkalieti, of prolonged boiling, or
of too intense heat, have often obtained, at the end of the analysis,
many substances which were erroneously described as proximate
principles, while they were only the remains of an altered and dis-
organized material. Thus, the fibrous tissues, if boiled steadily for
thirty-six hours, di,=solve, for the most part, at the end of that time,
in the boiling water; and on cooling the whole solution solidities
into a homogeneous, jelly-like substance, which has received the
name of ijtlatine. But this gelatine does not really exist in the body
as a proximate principle, since the fibrous tissue which produces it
i.-4 not at lirst soluble, even in boiling water, and its ingredients
become altered and converteil into a gelatinous matter only by pro-
longed ebullition. So, again, an animal substance containing ace-
tates or lactates of soda or lime will, upon incineration in the open
air, yield carbonates of the same bases, the organic acid having been
destroyed, and replaced by carbonic acid; or sulphur and phospho-
rus, in the animal tissue, may be converted by the same means into
sulphuric and phosphoric acids, which, decomposing the alkalioe
carbonates, become sulphates and phosphates. In either case, the
analysis of the tissues, so conducted, will bo a deceptive one, and
useless for all anatomical and physiological poTposes, because its
real ingredients have been decomposed, and replaced by others, in
the process of mauipialatiou.

It is in this way that diiTerent chemists, operating upon the same
aninml solid or fluid, by following dift'erent plans of analysis, have
obtained difierent results; enumerating as ingredients of the body
many artificially formed substances, which are not, in reality,
proximate principles, thereby introducing much confusion into
physiological chemistry.

PBOXIMATE PRINCIPLES IN GENKBAL.

It is to b« kept constantly in view, in the examination of an
animal tissue or fluiJ, that the object of the operation is simply the
aepanUum of ita ingredimU from each other, and not iLeir decomposi-
tion or ultimate analysis. Only tho simplest forma of clieraical
manipulation should, therefore, be employed. Tho substance to
bo examined should first be subjected to evaporation, in order to
extract and estimate its water. This evaporation must be conducted
at a heat not above 212° K., since a higher temperature would de*
stroy or alter some of the animal ingredienlB. Then, from the
dried residue, chloride of Hodiuin, alkaline sulpliatos, earhonauw,
and phosphates may be extracted with water. Coloring matters
may be separated by alcohol. Oils may be dissolved out by ether,
&C. &C. When a chomicnl decomposition is unavoidable, it must
be kept in sight and allerward coRrected. Thus the glyko-cholate
of soda of tho bile is separated from certain other ingredients by
precipitating it with acctalo of leacl, forming glyko-cholate of lead;
but this is afterward decomposed, in its turn, by carbonate of soda,
reproducing tho original glyko-cholate of soda. Sometimes it is
impossible to extract a proximate principle in an entirely unaltered
form. Thus the fibrin of the blood can be separated only by allow-
ing it to coagulate; aod once coagulated, it is permanently altered,
and can no longer present all iU urigiual characters of Quidity, kc,
as it existed beforchaud in the blood. lu such instances as this,.
we can only make allowance for an unavoidable dilBcuIty, aod be
careful ihat tho subsUincc suffers no further alteration. By bearing
Id mind the above considerations, we may form a tolerably correct
estimate of the nature and quantity of all of the proximate princl-
pl«B existing in the substance utider examination.

The manner in which tho proximate principles are associated
together, so as to form the animal tissues, is deserving of notice.
In every animal solid and iluid, there is a considerable number oF
proximate principles, which are jjresont in certain proportions, and
which are so united with each other that the mixture presents a
homogeneous appearance. But this union is of a complicated cha-
racter; and the presence of each ingredient de[)endts to a certain
extent, upon that of the others. Some of them, auch as the alkaline
carbonates and phosphates, are iti solution directly in the water.
Some, which are insoluble in water, arc held in .-mlution by ihe
presence of other soluble substances. Thus, phosphate of lime is
held in solution in the urioe by the biphoaphnte of soda. In the
blood, it is dissolved by the albumen, which is itself fluid by union

PROXIMATE PRIXCIPLKS IN QXIVERAL,

with the water. The same substance may be fluid in one part of
the body, and solid in another part. Thus in the blood and secre-
tions the water is fluid, and liulds in solulion other substances, both
animal and mineral, while in the bones and cartilages il is solid
not crystallized, as in the case of ice or of saline subalances which,
contain water of crystallization, but amorphous and solid, by iho
fact of its intimate union with the aoimal and saline ingiedients,
which are abundant in quantity, and which are themselves present
in the solid form. Again, the phosphate of lime in the blood is
fluid by solution in the albumen ; but in the bones it forms a solid
substance with the animal matter of the osseous tissue; and yet
the union of the two is as intimate and homogeneous in the bones
as in the blood. A proximate principle, therefore, never exists
alone in any part of the body, l^t is always intimately associated
with a number of others, by a kind of homogeneous mixture or
solution.

Every animal tissue and fluid contains a number of proximate
principles which are present, as we have already mentioned, in
certain characteristic proportions. Thus, water is present in very
large quantity in the perspiration and the saliva, but in very small
quantity in the bones and teeth. Chloride of sodium is compara-
tively abundant in the blood and deficient in the muscles. On the
pthcr hand, chloride of potaasiom ia more abundant in the muscles,
less 90 in the blood. But these proportions, it is important to ob- fl
serve, are nowhere absolute or iavariable. There is a great differ-
ence, in this respect, between the chemical composition of an inor- i
ganic substance and the anatomical constitution of an animal fluid. ^|
The former ia always constant and definite; the latter is always "
subject to certain variations. Thus, water is always composed of
exactly the same relative quantities of oxygen and hydrogen; and
if these proportions be altered in tho Icaat, it ihereby ceases to bo
water, and is converted into some other substance. But in the
urine, the proportions of water, urea, urate of soda, phosphates,
&Q., vary within certain liiniUi in difl'erent individuals, and even ia
the some individual, from one hour to another. This variation,
which is almost constantly taking place, within the limits of health, i
is characteristic of all the animal solids and fluids; for they ara S
composed of different ingredients which arc supplied by absorption
or formed in the iuleriur, and which are eonstautty given up again,
under the same or dillerent forms, to the surrounding media by the
unceasing activity of the vital processes. Every variation, then,

PBOXII(AT£ FBINCIPLES IN GENBBAL. 61

in the general coodition of the body, as a whole, is accompanied by
a corresponding variation, more or less pronounced, in the consti-
tution of its different parts. This constitution is consequently of
a very difl»rent character from the chemical constitution of an
oxide or a salt. Whenever, therefore, we meet with the quantita-
tive analysis of an animal fluid, in which the relative quantity of
its different ingredients is represented in numbers, we must under-
stand that such an analysis is always approximative, and-not abso-
lute.

The proximate principles are naturally divided into three differ-
ent classes.

The first of these classes comprises all the proximate principles
which are purely inobganic in their nature. These principles are
derived mostly from the exterior. They are found everywhere, in
unorganized as well as in organized bodies; and they present them-
selves under the same forms and with the same properties in the
interior of the animal frame as elsewhere. They are crystallizable,
and have a definite chemical composition. They comprise such
substances as water, chloride of sodium, carbonate and phosphate
of lime, &c.

The second class of proximate priociples is known as CBTSTAL-
UZABLE SUBSTANCES OF OBOANic OBioiN. This is the name given
to them by Robin and Verdeil,' whose classification of the proxi-
mate principles is the best which has yet been offered. They are
crystallizable, as their name indicates, and have a definite chemical
composition. They are said to be of "organic origin," because they
first make their appearance in the interior of organized bodies, and
are not found in external nature as the ingredients of inorganic
substances. Such are the different kinds of sugar, oil, and starch.

The third class comprises a very extensive and important order
of proximate principles, which go by the name of the Oboanic
Substances proper. They are sometimes known as "albuminoid"
substances or "protein compounds." The name organic substances
is given to them in consequence of the striking difference which
exists between them and all the other ingredients of the body. The
substances of the second class differ from those of the first by their

> Cliiinle AnstomlqQM fit Phralologiqoe. Puis, 1663.

62 PROXIMATE PBINOIPLBS IN OSNBBAL.

exclusively organic origin, but they resemble the latter in their cry b-
tallizability and their definite chemical composition ; in consequence
of which their chemical InTestigation may be pursued in nearly
the same manner, and their chemical changes expressed in nearly
the same terms. But the proximate principles of the third class
are in every respect peculiar. They have an exclusively organic
origin ; not being found except as ingredients of living or recently
dead animals or vegetables. They have not a definite chemical
composition, and are consequently not crystallizable; and the forms
which they present, and the chemical changes which they undergo
ID the body, are such as cannot be expressed by ordinary chemical
phraseology. This class includes such substances as albumen,
fibrin, casein, Ac.

PBOXIHATB PRINCIPLES OF THE FIRST CLASS. 53

CHAPTER II.

PROXIMATE PBINOIPLES OP THE FIRST CLASS.

The proximate principles of the first class, or those of an inor-
ganic nature, are very nameroos. Their most promioent characters
have already been stated. They are all crystallizable, and have a
definite chemical composition. They are met with extensively in
the inorganic world, and form a large part of the crust of the earth.
They occur abundantly in the different kinds of food and drink;
and are necessary ing^redients of the food, since they are necessary
ingredients of the animal frame. Some of them are found universally
in all parts of the body, others are met with only in particular
regions; bat there are hardly any which are not present at the
same time in more than one animal solid or fluid. The following
are the moat prominent of them, arranged in the order of their
respective importance.

1. "Water. — Water is universally present in all the tissues and
fluids of the body. It is abundant in the blood and secretions,
where its presence is indispensable in order to give them the fluidity
which la necessary to the performance of their functions; for it
is by the blood and secretions that new substances arc introduced
into the body, and old ingredients discharged. And it is a neces-
sary condition both of the introduction and discharge of substances
naturally solid, that they assume, for the time being, a fluid form;
water is therefore an essential ingredient of the fluids, for It holds
their solid materials in solution, and enables them to pass and repass
through the animal frame.

But water is an ingredient also of the solids. For if we take a
muscle or a cartilage, and expose It to a gentle heat in dry air, it
loses water by evaporation, diminishes in size and weight, and be-
comes dense and atiSl Even the bones and teeth lose water by
evaporation in this way, though iu smaller quantity. In all these
solid and semi-solid tissues, the water which they contain is oaeftal

fii

PBOXIMATB PBlNOrPLES OF THE FIRST CLASS.

Bill) .

. . S80

100

Milk

. . B87

130

PancrMticJnic*

. 900

55f>

nrlu«

. 936

760

Lynpli ,

. 9flO

76 B

Oartrici Juica .

. 878

"AO

Pvjitpi ration,

. 980

795

galivs. .

. 999

805

by giving them the special consistency which is characteristic of
them, and which would be Io3t without it. Thus a tendon, in its
natural condition, is white, glistening, and opaque; and though very
strong, perfectly flexible. If its water be expelled by evaporation
it beuoracB yellowish in color, shrivelled, semi-transparent, inflexi-
ble, and totally unfit for performing iw mechanical functions. The
aamo thing is true uf the akin, muscles, cartilages, &c.

The following is a list, compiled by Uobin and Vertleil from
various ob3er%'era, showing tho proportion of water per thousand
parts, in different solidf* and fluids: —

QvASTPn or Watbr n 1,000 pabt* ix

Teeth
Bon«a
Curtilag* .
Uosolei .
Li^Amenlfi
Brnin

S/novUl duld

According to the best calculations, water constitutes, in the
human subject, between two-thirds and three-quarters of the entire
weight fjf the body.

The water which thus forms a part of the animal frame is derived
from without. It is taken in the different kinds of driak, and olso
forms an abundant ingredient in the various articles of food. For
no articles of food are taken in an absolutely dry state, but all
contain a larger or smaller quantity of water, which may readily
be expelled by evaporation. The quantity of water, therefore,
which is daily taken into the system, cauuot be ascertained in any
case by simply measuring the quantity of drink, but its proportion
in the solid food, taken at tho same timo, mnst also bo determined
by experiment, and this ascertained quantity added to that which
is taken in with the fluids. By measuring the quantity of fluid
taken with the drink, and calculating in addition the proportion
existing in the solid food, we have found that, for a healthy adult
man, the ordinary quantity of water introduced per day, U a little
over 4J pounds.

After forming a part of tho animal solids and fluids, and taking
part in the various physical and chemical processes of the body, tho
water is again discharged; for iia presence in tho body, like that
of all the other proximate principles, is not permanent, but only

CBLOBIDK OF 80D1UU.

/temporary. After being taken in with the food and drink, it is
IfBsociated with other principles in the fluids and solids, pFissing
>ni the intestine to the blood, and fratn the blood to the tissues
id secretions. It afterwsrd makes its exit from the body, from
Ivhich it is discharged by fourdinereQt passages, viz., in a lit^uid
Ifbrtn with the nrine and the feces, and in a gaseous form with tho
)reath and the perspiration. Of all the water which is expelled in
^kbis way, about 48 per cent is discharged with the urine and feces,'
land about 52 per cent, by the lungs and skin. The researchos of
' XaToisier and Seguiu, Valentin, and others, show that from a pound
and a half to two pounds is discharged daily hy the skin, a little
over one pound hy exhalation from tho Uings, and a little over two
ponnds by tho urine. Both the absolute and relative amount dis-
charged, both io a liquid and gaseous form, varies according to
circumstances. There is parlicuhirJy a. compensating action in this
respect between the kidneys and the skin, so that when the cutane-
ous perspiration is very abundant tho urine is less so, and vice iiersd.
The quantity of water exhaled from the lungs varies also with the
state of the pulmonary circulation, and with the temperature and
l^drjness of the atmosphere. The water is not discharged at any
time in a state of purity, but is mingled in the urine and feces with
nline substances which it holds in solution, and in the cutaneous
kftnd pulmonary exhalations with animal vapors and odoriferous
VBabetaDces of various kinds. In the perspiration it is also mingled
with saline substances, which it leaves behiud on evaporation.

2. Chloride of Sodium. — This substance is found, like water,
throughout the different tissues and fluids of the budy. The ouly
exception to this is perhaps the enamel of the teeth, where it has
not yet been discovered. Its presence is imporuint in the body, as
regulating the phenomena of endosraosis and exosmosis in different
parts of the frame. For we know that a solution of commou salt
^passea through aolmal membranes much less readily thou pure
water; and tissues which have been desiccated will absorb pure
water more abundantly than a saline solution. It must not be sup-
posed, however, that the presence or absence of chloride of sodium,
or its varying <iuautity in the animal fluids, is the only couditioQ
which regulates their transudation through the animal membranes.
The maDDor iu wbioh endosmosis and exosmosis take place ia the

• Op. olt., ToU It. pp. 143 ind 14fl.

PROXIMATB PBISCTPLES OF THE FIRST OLAflS.

animal frame depends upoa the relative quantity of all tlie ingre-
dients of the fluids, as well as on the constitution of the solids
thcmsclvM; and the chloride of sodium, as one iogredient among
many, influences these phenomena to a great extent, though it does
not regulate tbem exclusively.

It exerts also an important influence on the solution of various
other ingredients, with which it is associated. Thus, in the blood
it increases the solubility of the albumen, and perhaps also of the
earthy phosphates. The blood-globules, again, which become dis-
integrated and dissolved in a solution of pure albumen, are main-
tained in a state of integrity by the presence of a small quantity of
chloride of sodium.

It exists in the following proportions in several of the solids and
fluids :' —

QDAxn-TT or Ciimreiib ap Sotuvu ix 1,(>00 pxan ni tbs

UoBotea

Btle

3.S

Banes

2.6

Blood .

4.5

Uilk

Uncafl . .

flAlivft

1.&

AqueoQi hantor .

Urine

VitreooB humor

In the blood tt is rather more abundant than all tho other saline
ingredients taken together.

Since chloride of sodium is so universally present in all parts of
tho body, it is an important ingredient also of the food. It occurs,
of course, in all animal food, in the quantities in which it naturally
cxiatfl in the corresponding tissues; and in vegetable food also,
though in smaller amount. Its proportion in muscular flesh,
however, is much less than in tho blood and other fluids. Conse-
i^ucntly, it is not supplied iu sulHcieut quantity as an ingredient of
animal and vegetable food, but is taken also by itself as a condi-
ment. There is no other sulMtance so universnlly used by all races
and conditions of moo, as an addition to tho food, as chloride of
ecdium. This custom does not simply depend on a fancy for grati-
fying the palato, but is based upon an instinctive desire for a sub*
ftancc which is necessary to the proper constitution of tho tissues
and fluids. Even the herbivorous animals are greedy of it, and if
freely supplied with it, are kept in a much better condition than
when deprived of its use.

The importance of chloride of sodium in this respect has been
well demonstrated by BoussingauU, in his experiments on tbo

■Robin nud V«rdL-il.

OTtLDRIDB OF SODICM.

fattening of animals. These observatioua were made upon six

.bullocks, Belected, ns nearly 05 possible, of the same age and vigor,
ind subjected to comparative csperimcat, Tlicy were all flupplied

'with aD abundance of nutritious food; but three of them (lot No.

II) rewivcd also a little over 500 grains of salt each per day. The
jmaiiiitig three (lot Ko. 2) received no salt, but iu other respects

\ were treated like the first. The result of these esperimeDts is given
by Boussingaalt as follows; — '

"Though salt administered with thp food has bat little effect in
increaaiog the size of the animal, it appears to exert a favorable
inOueoce upon his qualities and general aspect. Until the end of
March (the experiment began in October) the two lots experimented
on did not present any marked difference in their appearance ; but
in the course of the following April, thia JiDerence became i^uite
manifest, even to an unpractised eye. The lot No. 2 had thou been
without salt for sis mooths. In the animals uf both lots the skin
bad a fine and substantial texture, easily stretched and separated

• from the ribs; but the hair, which was tarnished and disordered in
the bullocks of the second lot, was etnootb and glistening in those
of the Crst As the experiment went on, these characters became
more marked; and at the beginning of October the animals of lot
Ko. 2, after going without salt for an entire year, presented a rough

find tangled hide, with patches here and there where the skin was
entiroly uncovered. The bullocks of lot No. 1 retained, on the
oontrary, the ordinary aspect of stall-fed animals. Their vivacity
aod their frei^uent attempts :ii mounting contrasted strongly with
the dull and unexcitablo a-spect presented by the others. No doubt,
the first lot would have commanded a higher price in the market
than the second."

Chloride of sodium acts also in a favorable manner by exciting
the digestive fluids, and assisting in this way the solution of the
food. For food which is tasteless, however nutritious it may be in
other respects, is taken with reluctance and digested with difficulty ;
while the attractive flavor which is developed by cooking, and by
the addition of salt and other condiments in proper proportion,
excites the secretion of the saliva and gastric juice, and facilitates
consequently the whole process of digestion. The chloride of
sodium is then taken up by absorption from the intestine, and is
deposited ia various quantities in diQerent parts of the body,

I Chlmla AgHoolv, Pari*, IBM, p. 271.

PROXIl

flNClPLEd

[B&T CLASS.

It is discharged with the urine, mucus, cutaneous perspiration,
ko., in solatioD ia the water of these lluids. According to the esti'
mates of M. Barral,' a small quantity of chloride of Eodium dis-
appears in the body ; siuce he finds by acciirate comparison that all
the salt introduced with the food is not to be found in the excreted
fluids, but tliat about ona-fiflh oCit remains unaccounted for. This
portion is supposed to undergo a double decomposition in the blood
with phosphate of potassa, forming chloride of poiasaium and phos-
phate of soda. By far the greater part of the chloride of sodium,
however, escapes under its own form with the secretions.

S. Chloride op Potassium. — This subatiiuce is found in the
muscles, the blood, tlie milk, the urine, aud various other fluids
and tissues of ihe body. It is not so universally present as chlo-
ride of sodium, and not so important as a proximate principle.
In some parts of the body it i^ n^oro abundant than the latter salt,
ID others less so. Thus, in the blood there ia mora ohloride of
sodium than chloride of potassium, but in the muscles there is more
chloride of potassium than chloride of sodium. This substance is
always in a fluid form, by its ready solubility in water, and is easily
separated by lixiviation. It is introduced mostly with the food, but
is probably formed partly in the interior of the body from chloride
of sodium by double decomposition, as already mentioned. It ia
discharged with the mucus, the saliva, and the urioe.

4. Phosphate of Lime. — This is perhaps the moat important
of the mineral ingredients of the body next to chloride of sodium.
It is met with universally, in every tissue and every fluid. Its
quantity, however, varies very much in diBercnt parts, as will be
seen by the following list: —

QitAsriTT or Pbosi'rate or Tjimn ik l.niin i>ixt« ixtiib
Enamel of tLe teeth , . 663 Uusolea . . . .3.1

Dnitin* . . . . 6U Blood . . . .0,3

Bo&M .... D60 Gastria Jaioe . . .0.'

CArliLagAR ... 40

It occurs also under different physical conditions. In the bones,
teeth, ami cartilages it is solid, and gives to these tissues the resist-
ance and solidity which are characteristic of them. The calcareous
salt is not, however, in these instances, simply deposited mechani-
cally in the substunceof the bone or cartilage as a granular powder,

' Id Rvbip Kod Voriluil, op. oU., vol. !1. p. 193.

PH08PHATB OF LIKB.

fi«

Fig. 1.

but is tDtimately united with the animal matter of the tissaee, like
a coloring matter in oolored glass, so as tu present a more or less
homogeneous appearance. It can, however, be readily dissolved
out by maceration in dilate muriatic acid, leaving behind the
animal substance, which still retains the original fi^nn uf the bone
or cartilage. It is not, therefore, united with the animal matter eo
as to low its identity and form a new chemical substance, as where
an acid combines with an alkali to form a sah, but in the same
manner as salt unites with water in a saline solution, both sub-
stances retaining their original character aud composition, but so
intimately associated that they cannot be separated by mechanical
means.

In the blood, phosphate of lime is in a liquid form, notm-ith stand-
ing its insolubility in water and in alkaline Suicts, being held in
K>lution by the albuminous matters of the circulating liluid. lu the
nrino, it is retained in aolntron by the bi-pht5:*phato of soda.

lo all the solid tissues it is useful by giving to them their proper
coDsisience and solidity. For example, in the ena-
mel of the teeth, the hardest tissue of the body, it
predominates very much over the animal matter,
and is present in greater abundnnce there than in
any other part of the frame. In the dentine, a
softer tissue, it is in somewhat smaller quantity,
and in the bones smaller still ; though in the hones
it continues lo form more than one-half the entire
mass of the osseous substance. The importance of
phosphate of lime, in communicating to bones their
natural stiflhess and consistency, may be readily
shown by the alteration which they suffer from its
remoTal. If a long bone be macerated tu dilute
muriatic acid, the earthy salt, as already mentioi]<.':il,
is entirely dissolved out, after which the bone loses
its rigidity, and may be bent or twisted in any direc-
tion without breaking. (Fig. 1.)

Whenever the nutrition of the bene during life
is interferod with from any pathological cause, so
that its phosphate of lime becomes deficient in
amount, a softening of the osseous tissue is the
consequence, by which thu bones yield to external
pressure, and become more or less distorted. (Oateo-malakia.)

AAcr forming, for a time, a part of the tissues and fluids, the

fl BrLA T [IB IB

.1 anor. urtnr ma.

KCltl. (FtiiIII ■ (pool.

uifiu In ihn muiaum

at LiM Coll. or I'brrf-

cUq* aad SorgouiM.)

PROXIMATE PRTNCIPLGS OP THB FIRST OIiASS,

phosphate of lime is discharged from the body by the uriuc, the
perflpiration, mxicus, &c. Much the larger portion is discharge*! by
the urine. A small quftntity also occurs in the feces, but this is pro-
bftbly only the superflaous residue of what i$ taken in with the food.

5. Cjlruokate of Lime. — Carbonate of lime is to be found in
the bones, and sometimes in the urine. The concretions of the
internal ear are almost entirely formed of it. It very probably
occurs also in the blood, teeth, cartilages, and sebaceous matter;
but its presence here la not quite certain, since it may have been
produced from the lactate, or other organic combination, by the
process of incineration. In tlie bones, it is in much smalier quan-
tity iban the phosphate. Its solubility in the blood and the urine
is accounted for by the presence of free carbonic acid, and also of
chloride of potassium, both of which substances exert a solvent
action on carbouatc of lime.

6. Carbonate or Soda. — This substance exists in the bones,
blood, saliva, lymph, and urine. As it is readily soluble in water,
it naturally Bssumos the liquid form in the animal fluids. It is
important principally as giving to the blood its alkalescent reaction,
by which the solution of the albumen is facilitated, and various
other chemico- physiological proceases in the blood accomplished.
The alkalescence of the blood is, in fact, necessary to life; for it is
found that, in the living animal, if a mineral acid bo gradually
injected into the blood, so dilute as not to coagulate the albumen,
death takes place before its alkaline reaction bos been completely
neutralized.'

The carbonate of soda of the blood is partly introduced as suob
with the food ; but the greater part oF it is formed wilhtn the body
by tliG decomposition of other salts, introduced with certain fruits
and vegetables. These fruits and vegetables, such as apples, cher*
ries, grapes, potatoes, &c., contain raalates, tartrates, and citrates
of soda and potassa. Now, it has been often noticed that, after
the use of acescent fruits and vegetables containing the above salts,
the urine bocomea alkaline in reaction from the presence of the
alkaline carbonates. Lehmann' found, by experiments upon his
own person, that, within thirteen minutes after taking half an oonco

■

' CI. TVniAM. L>ectun?« on tbo Ulood ; roportod bjr W. F. Atleir, M. U.
delpliU, 1854, p. 31.
' rhj^lologlcnl Ch<;mlstrr. Philadelphia «d., vol. I. p. HJ.

PbiU-

PHOSPHATES OF MAGNESIA, SODA, AND POTASSA. 61

of lactate of soda, the urine bad an alkaline reaction. He also ob-
served that, if a solation of lactate of soda were injected into the
jagDlar vein of a dog, the urine became alkaline at the end of fire,
or, at the latest, of twelve minutes. The conversion of these salts
into carbonates takes place, therefore, not in the intestine but in the
blood. The same observer^ found that, in many persona living on
a mixed diet, the urine became alkaline in two or three hours aft«r
swallowing ten grains of acetate of soda. These salts, therefore,
on being introduced into the animal body, are decomposed. Their
organic acid Is destroyed and replaced by carbonic acid ; and they
are then discharged under the form of carbonates of soda and potassa.

7. Carbonate of Potassa.— This substance occurs in very
nearly the same situations as the last. In the blood, however, it is
in smaller quantity. It is mostly produced, as above stated, by
the decomposition of the malate, tartrate, and citrate, iu the same
manner as the carbonate of soda. Its function is also the same as
that of the soda salt, and it is discharged in the same manner from
the body.

8. Phosphates or Magnesia, Soda, and Potassa.— All these
substances exist universally in all the solids and fluids of the body,
but in very small quantity. The phosphates of soda and potassa
are easily dissolved in the animal fluids, owing to their ready solu-
bility in water. The phosphate of magnesia is beld in solution in
the blood by the alkaline chlorides and phosphates; in the urine,
by the acid phosphate of soda.

A peculiar relation exists between the alkaline phosphates and
carbonates in differenl classes of animals. For while the fluids of
carnivorous animals contain a preponderance of the phosphates,
those of the herbivora contain a preponderance of the carbonates:
a peculiarity readily understood when we recollect that muscular
flesh and the animal tissues generally are comparatively abundant
in phosphates; while vegeteble substances abound in salts of the
organic acids, which give rise, as already described, by their decom-
position in the blood, to the alkaline carbonates.

The proximate principles included in the above list resemble
each other not only in their inorganic origin, their crystallizability,

> Ph7»iological Chemiptry, vol. il. p. 130.

PBOZIHATE PRTSTCIPLES OP TRS FIRST CLASS.

flnd their definite chemical composition, but also id the part which
thejr takti in the constitution of the animal fratiie. They are
dtstiaguiahed in this respect, first, by being derived entirely from
without. There are a Few exceptions to this rule ; aa, for example,
in the case of the alkaline carbonates, which partly originate in
the body from the decomposition of malates, tartrates, iic. These,
however, are only exceptions; and in general, the proximate prin-
ciples belonging to the first claai are introduced with the food,
and taken up by the animal tissues in precisely the same form
under which ihey occur in external nature. The carbonate of lime
in the bones, tbe chloride of sodium in the blood and tissues, are
the same substances which are met with in the calcareous rocks,
and in solution in sea water. They do not sufl'er any chemical
alteration in becoming constitocnt porta of the animal frame.

They are equally exempt, as a general rule, from any alteration
while they remain in the body, and during their passage tlirough
it The exceptions to this rule are very few ; aa, for example, where
a small part of the chloride of sodium suffers double decomposition
with phosphate of potaasa, giving rise to chloride of potassium and
phosphate uf soda; or where the phosphate of soda itself gives up
a part of its base to an organic acid (uric), and is converted in this
way into a bi-phosphate of soda.

Nearly the whole of these substances, 6nally, are taken up un-
changed from the tissues, and dischargetl unchanged with the excre-
tions. Thus we find the piiosphato of lime and the chloride of so-
dium, which were tnken in with the food, dischnrged again under
the aarae form in the urine. They do not, therefore, for the moat
part, participate directly in the chemical changes going on in the
body; but only serve by their presence to enable those changes to
be accomplished in the other ingredients of the animal frame, which
are necessary to the process of nutrition.

PBOXIlfATE PBINCIFLS8 OF THE SECOND CLASS. 63

CHAPTEE III.

PROXIMATE PEINCIPLES OF THE SECOND CLASS.

The proximate principles beloDging to the second class are
divided into three principal groups, viz: starch, sugar, and oil.
They are distinguished, in the first place, by their organic origin.
Unlike the principles of the first class, they do not exist in
external nature, but are only found as ingredients of organized
bodies. They exist both in animals and in vegetables, though in
somewhat diSferent proportions. All the substances belonging to
this class have a definite chemical composition ; and are further
distinguished by the fact that they are composed of oxygen,
hydrogen, and carbon alone, without nitrogen, whence they are
sometimes called the "non-nitrogenous" substances.

1. Stabch (C„H,„0,o). — The first of these substances seems to
form an exception to the general rule in a very important particu-
lar, viz., that it is not crystallizable. Still, since it so closely
resembles the rest in all its general properties, and since it is easily
convertible into sugar, which is itself crystallizable, it is naturally
included in the second class of proximate principles. Though not
crystallizable, furthermore, it still assumes a distinct form, by
which it differs from substances that are altogether amorphous.

Starch occurs in some part or other of almost all the flowering
plants. It ia very abundant in corn, wheat, rye, oats, and rice, in
the parenchyma of the potato, in peas and beans, and in most
vegetable substances used as food. It constitutes almost entirely
the different preparations known as sago, tapioca, arrowroot, &c.,
which are nothing more than varieties of starch, extracted from
different species of plants.

The following is a list showing the percentage of starch occurring
in different kinds of food : — '

■ Fereira on Food and Diet, New York, 1843, p. 39.

PROXIHATS PRINCIPLB9 OP THE SECOND CLASS.

QDAXTtTT or Starcb

IR ]00 pARta iir

BIM .

. 85.07

Wheat flour .

. 66.ta

Ma-ixo

. 80.92

Icnlnni] moM

. 44.60

BuUy meal .

. 07.1 B

Kidnej bean .

. 3&.»4

Rjr* meal

. ei.07

P9U

. 32.45

Ost meftl

. B9.00

Potato .

. 15.70

"When porificd from foreign
powder, which gives rise to a pecu

Fig- 2.

ORArs* or I*aTATt> Stahcm.

substances, starch is a white, lighl
tr cniclv]iug sonHation when
rubbed between the fingers.
It is not amorphous, as we
have already slated, but is
composed of solid grauules,
which, while they have a
general reserablanco to each
other, differ somewhat in va-
rious particulars. The starch
grains of the potato (Fig, 2)
vary considerably in size.
The smallest bave a diameter
of ToSoo. the largest ,J,> of
an inch. Thoy are irregu-
larly pear-shaped in form,
and are marked by concen-
tric lainirju), as if ttie matter

of which they are composed had been deposited in successive layers.

At one point on the surface of every starch grain, there is a minute

pore or depression, called the
^' ' hilv^, around which the cir-

cular markiuga arearrauged
in a concentric form.

The starch granules of
arrowroot (Fig. 3) are gene-
rally smaller and more uui-
form in st;ie, than thoso of
the potato. They vary from
ao'ofl to rU of an inch in
diameter. They are elongated
aud cylindrical ia form, and
the concentric markings are
less distinct than in the pre-
ceding variety. The hilus

SrAion OiAivt ot Bi«mbi>* Aakovtoor.

STABCH.

has here aometimea thti form of a circular pore, and sometimes that
of a transverse fissare or slit.

The grains of wheat starch (Fig. 4) are still smaller than those
of arrowroot They vary

from

TODOO

to .j^^of an inch

Fig. 4.

in diameter. They are ,
nearly circular in form, with
a round or transverse hilus,
but without any distinct
appearance of lamination.
Many of them are flattened
or compressed laterally, so
that they present a broad
surface in one position, and
a narrow edge when viewed
in the opposite direction.

The starch grains of In-
dian corn (Fig. 6) are of
nearly the same size with
those of wheat dour. They are somewhat more irregular and
angular in shape; and are oflen marked with crossed or radiating
lines, as if from partial fracture.

Starch is also an ingre-
dient of the animal body.
It was iSrst observed by
Purkinje, and aflerward by
Kolliker,' that certain bodies
are to be found in the interior
of the brain, about the late-
ral ventricles, in the fornix,
septum lucidum and other
parts, which present a cer-
tain resemblance to starch
graiDS,and which have there-
fore been called "corpora
amylacea." Subsequently
Virchow' corroborated the
above observations, and Moert<

Starch QBAiir* or Wsbat Fioub.

Fig. 6.

Starok Qmaimu or Imdiax Cos*.

•rlacea to be

■ Id Amerioui

66 PROXIMATE PRINCIPLES OF THE SECOND CLASS.

St^kcb Osaik* fsom Wall op Latrbal
TaSTaiCLEa; from ■ wamsn acml 3.^

really Bubstancea of a starcliy nature; since they exhibit the usual
chemical reactions of vegetable starch.
The starch granules of the human brain (Fig. 6) are transparent

and colorless, like those from
^" ' plants. They refract the light

strongly, and vary in size
from ^T'on to rT»„ of an
inch. Their average is yb"!! 5
of an inch. They are some-
times rounded or oval, and
sometimes angular in shape.
They resemble considerably
in appearance the starch
granules of Indian corn. The
largest of them present a
very faint concentric lamina-
tion, but the greater number
are destitute of any such
appearance. They have
nearly always a distinct hilus, which is sometimes circular and
sometimes slit-shaped. They are also often marked with delicate
radiating lines and shadows. On the addition of iodine, they become
colored, first purple, afterward of a deep blue. They are less firm
in consistency than vegetable starch grains, and can be more readily
disintegrated by pressing or rubbing them upon the glass.

Starch, derived from all these different sources, has, so far as
known, the same chemical composition, and may be recognized by
the same tests. It is insoluble in cold water, but in boiling water
its granules first swell, become gelatinous and opaline, then fuse
with each other, and finally liquefy altogether, provided a sufficient
quantity of water be present. After that, they cannot be made to
resume their original form, but on cooling and drying merely solidify
into a homogeneous mass or paste, more or less consistent, accord-
ing to the quantity of water which remains in union with it. The
starch is then said to be amorphous or "hydrated." By this process
it is not essentially altered in its chemical properties, but only in
its physical condition. Whether in granules, or in solution, or in
an amorphous and hydrated state, it strikes a deep blue color on
the addition of free iodine.

Starch may be converted into sugar by three different methods.
First, by boiling with a dilute acid. If stnrch be boiled with dilute

8U6AB. 67

DJtric, sulphuric, or muriatic acid during thirty-six hours, it first
changes its opalescent appearance, and becomes colorless and trans-
parent; losing at the same time its power of striking a blue color
with iodine. After a time, it begins to acquire a sweet taste, and
is finally altogether converted into a peculiar specie of sugar.

Secondly, by contact with certain animal and vegetable sub-
stances. Thus, boiled starch mixed with human saliva and kept
at the temperature of 100° F., is converted in a few minntes into
sugar.

Thirdly, by the processes of nutrition and digestion in animals
and vegetables. A large part of the starch stored up in seeds and
other vegetable tissues is, at some period or other of the growth of
the plant, converted into sugar by the molecular changes going on
in the vegetable fabric. It is in this way, so far as we know, that
all the sugar derived from vegetable sources has its origin.

Starch, as a proximate principle, is more especially important as
entering largely into the composition of many kinds of vegetable
food. With these it is introduced into the alimentary canal, and
there, during the process of digestion, is converted into sugar.
Consequently, it does not appear in the blood, nor in any of the
secreted fluids.

2. Sugar. — This group of proximate principles includes a con-
siderable number of substances, which differ in certain minor
details, while they resemble each other in the following particulars:
They are readily soluble in water, and crystallize more or less
perfectly on evaporation; they have a distinct sweet taste; and
finally, by the process of fermentation, they are converted into
alcohol and carbonic acid.

These substances are derived from both animal and vegetable
sources. Those varieties of sugar which are most familiar to us
are the following six, three of which are of vegetable and three of
animal origin.

Vegetable J o,,p^ ,„g„^ Ammal ) Li„„ugar,

■°B""- [sugar of starch. ^"«*"' I Sugar of honey.

The cane and grape sugars are held in solution in the juices of
the plants from which they derive their name. Sugar of starch, or
glucose, is produced by boiling starch for a long time with a dilute
acid. Liver sugar and the sugar of milk are produced in the
tissues of the liver and the mammary gland, and the sugnr of

68 PROXIMATE PBIKCIPLBS 0? THE SBCOlfD CLASS.

honey is prepared in some way by tlie bee from niiitcrials of vege-
table origin.

Those varieties differ but little in their ultimate chemical compo*
ailion. The following formutie have been cslablishcd for three of
them.

Cane sugar
Milk »ngi\T
Olucaaa .

=c^ii.*"«

Cane sugar is sweeter than most of tlie other varieties, and more
soluble in wntur. Some sugars, such as liver sugar and angar of
hooey, crystallize only with great tlifficulty; but ihis is probably
owing to their being mingled with other substances, from which it
is diflicult to separate them completely. If they could be obtained!
in a state of purity, they would doubtless crystallize as perfectly as
cane sugar. The diflercnt sugars vary also in the readiness with
which they undergo fermentation. Some of them, as grape sugar
and liver sugar, enter into fermentation very promptly; others,
auch as milk and cane sugar, with considerable didiculty.

The nbove are not to be regarded as the only varieties of sugar-
existing in nature. On the contrary, it is probable that nearly
every different species of anima! and vegetable produces a distinct
kind of sugar, differing slightly from the r«st in its degree of sweet-
ness, its solubility, its crystallization, its aptitude for fertnentatioo,
and perhaps in iLs elementary composition. Nevertheless, ihore is
so close a resemblance between them that they are all properly
regarded us belonging to a single group.

The teat most commonly employed for detecting the presence of
sugar is that known as Trammer's test. It depends upon the fact
that the saccharine substances have the power of reducing the
persalts of ooppcr when heated with them in au alkaline solution.
The test is applied in the following mauuer; A very small quantity
of sulphate of copper in solution should be added to the suspected'
li(]uid, and the mixture then rendered distinctly alkaline by the
addition of caustic potassa. The whole solution then takes a deep
blue color. On boiling the mixture, if sugar be present, the in-
soluble suboxide of copper is thrown down as an opaque red,
yellow, or orange-colored deposit; otherwise no change of color
takes place.

This lest requires some precautions in ils application. In tho
first place, it is not applicable to all varieties of sugar. Cane
sugar, for example, when pure, has no power of reducing the salts

' SUGAB. 69

of copper, even when present in large quantity. Maple sugar, also,
which resembles cane sugar in some other respects, reduces the
copper, in Trommer's test, but slowly and imperfectly. Beet-root
sugar, according to Bernard, presents the same peculiarity. If
these sugars, however, be boiled for two or three minutes with a
trace of sulphuric acid, they become converted into glucose, and
acquire the power of reducing the salts of copper. Milk sugar,
liver sugar, and sugar of honey, as well as grape sugar and glucose,
all act promptly and perfectly with Trommer's test in their natural
condition.

Secondly, care must be taken to add to the saspected liquid only
a small quantity of sulphate of copper, just sufficient to give to the
whole a distinct blue tinge, afler the addition of the alkali. If a
larger quantity of the copper salt be used, the sugar in solution
may not be sufficient to reduce the whole of it ; and that which
remains as a blue sulphate will mask the yellow color of.the sub-
oxide thrown down as a deposit. By a little care, however, in
managing the test, this source of error may be readily avoided.

Thirdly, there are some albuminous substances which have the
power of interfering with Trommer's test, and prevent the reduc-
tion of the copper, even when sugar is present Certain animal
matters, to be more particularly described hereafter, which are
liable to be held in solution in the gastric juice, have this effect.
This source of error may be avoided, and the substances in ques-
tion eliminated when present, by treating the suspected fluid with
animal charcoal, or by evaporating and extracting it with alcohol
before the application of the test.

A less convenient but somewhat more certain test for sugar is
iha.% of /ermenlatton. The saccharine fluid is mixed with a little
yeast, and kept at a temperature of 70° to 100° F. until the fer-
menting process is completed. By this process, as already men-
tioned, the sugar is converted into alcohol and carbonic acid. The
gas, which ia given off in minute bubbles during fermentation,
should be collected and examined. The remaining fluid is purifled
by distillation and also subjected to examination. If the gas be
fonnd to be carbonic acid, and the remaining fluid contain alcohol,
there can be no doubt that sugar was present at the commencement
of the operation.

The following list shows the percentage of sugar in various
articles of food.'

' Ferelra, op. cit., p. 55.

70 proxij^Tt^pbtnciplb^o^tii^bbcond class.

(kFAJCTITT or SrOAB U 100 TAKf* IX

Fist* . .
Clierrie*

l*UAI'h>>li

Tamarlnili
Purs .
RpAta

S<rc«t alinomla
Bitrlpy infill .

52.50
18.13

12.S0

U.52

fl.Ott

3.00

5.21

W]ient Soar
Rjre meal .
ItiHinn inMtl
P«ai .
Cqw'b milk
Am's lull It
Iluiuan lailk

4.20 to e.48

3.2S

Beaide the -^ugar, iherefore, which is taken into the nlimentftry
cannt in a pure form, a large quantity is also introducer! as an in-
gredient of tlie sweet -flavored fruits and vegetables. All the
starchy substances of the food .ire also converted into sugar in the
process of digestion. Two of the varieties ttf sugar, at leust,
originate in the interior of the body, viz., sugar of milk and liver
sugar. Tlie former exists in a solid form in the substance of the
mammary gland^ from which it passes in solution into the milk.
The liver sugar is found in the substance of the liver, and almost
always also in iho blood of the hepatic veins. The sugar which is
introduced with the food, aa well as that which is formed in the
liver, disappears by decomposition in the aniiual Ouids, and does
not appear in any of the e.Ycrctions.

8. Fat3. — These substances, lifco the sugars, are derived from

both animal and vegetable sources. There are three principal

varieties of them, which may be considered as representing the

class, viz : —

Olalne « C^^ U^ 0„

MJiiB*rlDB = Ci^ n;j 0„

Bloiriiw =C,„H,„0„

The principal difterence between the oleaginous and saccharine
substances, so far ns regards their ultimate chemical composition,
is that in the sugars the oxygen and hydrogen always exist together
in the proportion to form water; while in the fata the proportionsof
carbon and hydrogen are nearly the same, but that of oxygen is
considerably less. The fan arc all fluid at a high temperature, but
assume the solid form on cooling. Stenrinu, which is the most
BoUd of the three, liquefies only at 143*' F.; margarine at 118® F.:
while oleine remains fluid considerably below 100"* F., and even
very near the freezing point of water. The fats are all in.5olnble
in water, but readily soluble in ether. When treated with a solu-
tioQ of a caustic alkali, they ore decomposed, and as the result of

tbe decompoAiiirtn therenre formed two new bodies; firsl, glycerine,
wbicb is a oeutntl fluid aubstance, and secomlly, a fiitty acii^, vi/ :
oleic, megoric, or stearic acid, corresponding to the ]i\ut\ uf fnt
which liua Iwon used in iliu experimuiii. Th^ glye«rin» remains in
a free stotc, while the fatty acid unites ^s'lih tlie alkali employed,
forming an oieate, margnrate, or stearate. Tliis coiubinatiun i8
termed a soap, and the process by wbicb iE is forniei] is culled
Kij'oni/icalion. Tliis process, however, is not a simple dec;omposliion
nf iho fatty bmly, aince it can only take placo iti iho presence of
water; several equivalents of which unite with the elements of the
fatty body, and enter into the composition of the glycerine, &c., so
that the fatty acid and the glycerine together weigh more than tbe
original fatty substance which was decomposed. It is not proper,
therefore, to regard nn oleaginous body as formed by the union of a
fatty acid with glycerine. Ft is formed, on the contrary, in all ^iro-
babiUty, by the direct combination uf its ultiumle chemical elements.
The diSerent kinds of oil, fat, lard, suet, &e., cx>ntaia the three
oleaginous matters mentioned above, mingled together in difli-ront
proportions. The more solid fata contain a larger quantity of
alearine and margarine; the less consistent varieties, a larger pro-
portion of uleinc. Neither of the oleaginous matters, stearine,
margarino, or oleine, ever occur separately ; but in every fatty sub-
stance ihey are mingled together, so that the more fluid of them hold
in solution the more solid.

Generally speakiug, in the !'>«. 7.

living body, these fni.\turc8
ire fluid or nearly so; for
though both stearine and
margarine are solid, when
pure, at tbe onlinnry tem-
perature of the body, lliey
are held in solution, during
life, by the olcine with which
Ibey are associated. After
death, however, aa the body
cools, the stearino and mar-
garine sometimes separate
twm the mixture in a crys-
lallinc form, since the oleine
cao DO longer hold in sola-
two so large a quantity of them as it had dissolved at a higher
temperature.

>^--

STIi4mia> cr/SlBUlml frnm n Warm jolnlloii la

72 PEOXIHATE PElNCrPLBS Or THE SECOND CLASS.

These substances cryslalliKO in very slender noodles, wliich arc
aometiinea straiglit, but more often somewhat curved or wavy in
their outlino. (Fig. 7.)

They are always deposited in a more or less radiated form ; and
liave sometimes a very elegant, branched, or arborescent arrange-
iiiont.

When in a fluid elate, the fatly aubstances present ihemselves

under the form of drops or

Rs.S.

globules, which vary indefi-
nitely in size, but which
may be readily recognized
by their oplical properties.
They are circular in shape,
and have a faint amber color,
distinct in the largerglobules,
leaa so in the smaller. They
have a sharp, well defined
oailine (Fig. 8); and as ihey
refract the light strongly,
and act therefore as double
convex lenses, they present
a brilliant ccntre,surrounded
by a dark border. These
marks will generally be

sufficient to distin^uiah ihem under the microscope.
The following lint aliowa the percentnge of oily matter present in

various kinds of animal and vegetable food."

QuAtrrnv or Fat iir 100 pakts ix

Or.KAiiiiiAyi PaiKi^iPi.ta lie He max F4t.

FEIberta .

60.00

Ordinary moftt

. U.30

WttlimU

60.00

Liver of ihe ox

. S.89

CoooA-nuu . ,

47-00

Cow's [uiLk ,

. 3.13

OliVM .

32.00

Ilmnnn milk

. 3.55

I.itiseed . . .

22.00

Aasua' uiitlc . .

. 0.11

lliilinci com . .

9.00

Ijodta' milk .

. s.3a

Tolk of «ggs .

28.00

The oleaginous matters present a striking peculiarity as to the
form under which ihcy exist in the animal body; a ])cculiarity
which distinguishes them from oil the other proximate principles.
The rest of the proximate principles are all intimately associated
together by molecular anion, so us to form either clear solutions or

■ F*r«]re, op. cit.,p. 81-

FATS. 78

homogeneous solids. Thus, the sugars of the blood are in solution
io water, in company with the albumen, the phosphate of lime,
chloride of sodium, and the like; all of them equally distributed
throughout the entire mass of the fluid. In the bon^ and car-
tilages, the animal matters and the calcareous salts are in similarly
intimate union with each other; and in every other part of the
body the animal and inorganic ingredients are united in the same
way. But it is different with the fats. For, while the three prin-
cipal varieties of oleaginous matter are always united with each
other, they are not united with any of the other kinds of proximate
principles ; that is, with water, saline substances, sugars, or albu-
minous matters. Almost the only exception to this is in the nerv-
ous tissue; in which, according to Robin and Yerdeil, the oily
matters seem to be united with an albuminoid substance. Another
exception is, perhaps, in the bile ; since some of the biliary salts
have the power of dissolving a certain quantity of fat. Every-
where else, instead of forming a homogeneous solid or fluid with
the other proximate principles, the oleaginous matters are found
in distinct masses or globules, which are suspended in serous fluids,
interposed in the interstices between the anatomical elemeute, in-
cluded in the interior of cells, or deposited in the substance of
fibres or membranes. Even in the vegetable tissues, the oil is
always deposited in this manner in distinct drops or granules.

Owing to this fact, the oils can be easily extracted from the
organized tissues by the employment of simply mechanical pro-
cesses. The tissues, animal or vegetable, are merely cut into small
pieces and subjected to pressure, by which the oil is forced out
from the parts in which it was entangled, and separated, without
any further manipulation, in a state of purity. A moderately
elevated temperature facilitates the operation by increasing the
fluidity of the oleaginous matter ; but no other chemical agency is
required for its separation. Under the microscope, also, the oil-
drops and granules can be readily perceived and distinguished
from the remaining parts of the tissue, and can, moreover, be
easily recognized by the dissolving action of ether, which acts
upon them, as a general rule, without attacking the other proxi-
mate principles.

Oils are found, in the animal body, most abundantly in the
adipose tissue. Here they are contained in the interior of the
adipose vesicles, the cavities of which they entirely fill, in a state

74 PROXIMATE PEiyCIPLBS OF TOE SKC<

of health. 'rh(

I'twiules

IT«1

Ks-9-

HCMAM ADiroii TitaVB.

e 11 MJinewhflt
cotnpreiwioii. (Fig. it.) Thev
vary in diameter, in iho liii-
mmi subject, Trom aJe*^ sio
of nn inch, nml fire composeit
of a tLiij, structureless ani-
rniil membrane, forming n
closctl sac, in the interior of
which the oily matter la con-
tiiincd. There is hmv, aucord •
ingly, no union whatever of
iho oil with the other proxi-
mate principles, but only a
mechanical inclusion of it in
the interior of the vesicles.
Somclimca, when ctnacialion
19 going on, the oil partinlly
disappears from the cavity of
the adipose vesicle, and ita place is taken by a watery serum; but
the eeruua and oily fluids always remain distinut, and occupy difler
cnt parts of the cj]vity of the vesicle.

In the chyle, the oleaginous matter is in a state of emulsicn or
suspension in the form of minute pnrticles in a serous fluid. Its

subdivision is hero more cora-
Pig. 10. plele, nnd its molecules more

minutc,lbciuanywhereolse in
ihe boily. It presents the ap-
pearance (if a fine granular
dust, which has been known
by the name of the "molecu*
Inr base of the chyle." A
few of these gronules are to
be seen which mensure nt^flo
of an inch in diameter; but
they are generally much less
than this, and the greater part
are so small that they cannot
be accurately measured. (I'ig.
10.) For the same reason
they do not present the bril-
liant centre and dark border of the larger oil-globules ; but appear

CirTkr. front M>mm«n(ODi*aI ot ThonMla Dii«t,
Fran Iha l>i:ig.

FAT8.

bj traDHmitted light only as minute dark granules. The white
color and opacity of the chyle, as of all other fatty emulsiooa,
depend upon this molecular condition of the oily ingredients. The
albumen, salts, &o^ which are in intimate union with each other,
and in solution in the water, would alone make a colorless and
transparent fluid; but the oily matters, suspended in distinct par-
ticles, which have a different refractive power from the serous fluid,
interfere with its transparency
and give it the white color and
opaque appearance which are
characteristic of emulsions.
The oleaginous nature of these
particles is readily shown by
their solubility in ether.

In the milk, the oily matter
occurs in larger masses than
in the chyle. In cow's milk
(Fig. IIX these oil-drops, or
"milk-globulea," are not quite
fluid, but have a pasty con-
sistency, owing to the large
qoantity of margarine which
they contain, in proportion to

the oleine. When forcibly amalgamated with each other and
collected into a mass by prolonged beating or churning, they con-
stitute butter. In cow's milk,

OLOBCtLII OP COW'l HiLK.

the globules vary somewhat
in size, but their average
diameter is f^^is of "i" inch.
They are simply suspended
io the serous fluid of the
milk, and are not covered
with any albuminous mem-
brane.

In the cells of the laryn-
geal, tracheal, and costal car-
tilages (Fig. 12), there is
always more or less fat de-
posited in the form of round-
ed globules, somewhat similar
to those of the milk.

Fig. 12.

CiLL* OrCotTAL CAITILAntl, CODtalalDgOll-

Olobnlai. UamtD.

76 PROXIMATE PBiyciPLBS OT THE SECOXD CLASS.

Hsr«Tiv C1LI.A Hnman.

In the glandalar cells of the liver, oil occurs coustantly, in a

8tate of bealtli. It is hero deposilod in tho substance or the cell

(Fig. 18), generally in smaller
^' ^^- globules than the preceding.

In some cases of disease, it
accumulates in excessive
quantity, and produces the
state known as fatty degcnft-
ralion of the liver. This is
cunsaquL'Dtly only an aX'
Rggeraled condition of that
which normally exists in
health.

In the carnivorous animals,
oil exists in considerable
quantity in the convoluted
portion of the uriniferous
tubules. (Fig. 14.) It is here

in the form of granules and rounded dropti, which sometirnes appear

to fill nearly tlie whole calibre of the tubules.
It is found also in the secreting cells of the sebaceous and other

glandules, deptjsited in the
Pig- 1^ same niaDocr as in those of

the liver, but in smaller
quantity. It exists, beside,
in large proporLion, in a
granular form, in the secre-
tion of the sebaceous gland-
iiles.

It occurs nbnndantly in
llie marrow of the bones,
both under the form of free
oil-globules and inclosed in
the vesicles of adipose tissue.
It is found inconsiderable
quantity in the substance of
the yellow wall of the corpna
luteum, and is the immediate

cause of the peculiar color of this lx>dy.
It occurs also in the form of granules and oil-drops in the

muscular (Ibrcs of the uterus (Fig. 15), in which il begins to be

f^c

raiaiFHKOL-i TEKViiBaor D«W, froai Cortical
PunloD uf Kviapf,

FATS.

->^

Hdicdlak Ftbrbiuf Hoham tTTBKDi, thrv*
wMki ■.fter inrtvrtlloB.

rieposited soon af^r delivery, and where it continues to be present
daring the whole period of the resorption or involution of this organ.

In all these instances, the oleaginous matters remain distinct in
form and situation from the
other ingredients of the ani- ^'8- !*■

mal frame, and are only me-
chanically entangled among
its fibres and cells, or im-
bedded separately in their
interior.

A large part of the fat
which is found in the body
may be accounted for by that
which is taken in with the
food, since oily matter occurs
in both animal and vegetable
substances. Fat is, however,
formed in the body, independ-
ently of what is introduced
with the food. This im-
portant &ct has been deSnitely ascertained by the experiments of
MM. Pumas and Milne- Edwards on bees,' M. Persoz on geese,* and
finally by those of M. Boussingault on geese, ducks, and pigs.' The
observers first ascertained the quantity of fat existing in the whole
body at the commencement of the experiment. The animals were
then subjected to a definite nutritious regimen, in which the
quantity of fatty matter was duly ascertained by analysis. The
experiments lasted for a period varying, in-different instances, from
thirty-one days to eight months; after which the animals were
killed and all their tissues examined. The result of these investi-
gations showed that considerably more fat had been accumulated
by the animal during the course of the experiment than could be
accounted for by that which existed in the food; and placed it
beyond a doubt that oleaginous substances may be, and actually
are, formed in the interior of the animal body by the decomposition
or metamorphosis of other proximate principles.

It is not known from what proximate principles the fat is pro-
duced, when it originates in this way in the interior of the body.
Particular kinds of food certainly favor its production and accu-

< Annales de Chim. et de Pfays., 3d series, vol. zfv. p. 400. ' Ibid., p. 408.
*Chimie Agricole, Paris, 1854.

78 PROXIMATE fRlNClPLKS OF THE SSCOKD CLA39.

mulfltion to a cotiaiderable (degree. It is well known, for instance,
that in augnr-growiiig countries, as in Louisiann and tlie Wwl
ladies, during the (mw weeks occupied in gatherings the cane nnd
exlractiug tlie sugar, all the negroes employed on the phiniali'ins.
nnd even the horses and cattte, ihat are allowed to feed freely on
the saccharine juices, grow remarkably fat; and that they again lose
their aiijierabundunt fleiih when the seiisun is past. Kven in these
instances, however, it is not certain whether the saccharine substances
are directly converted into fat, or vfhcther they are first assimilated
and only afterward supply the materials lor its production. The
abundant accuruulatioa of fat in certain regions of tb« body, and its ■
absence in others; nnd more particularly its constant occurrence in
certain situaiinii.i to which it could not bu transported by the blood,
as for example the interior of the cells of the costal cartilages, the
substance of the muscular fibres of the nterus after parturition, &c.,
make it probable that under ordinary conditions the oily matter is
formed by decomposition of the tissues upon the very spot where ii
subsequently makes its appearance.

In ih'6 female durinj^ lactation a large part of the oily matter
introduced with the food, or formed in the body, is discharged with
the milk, and goes to the support of tho infant. But in the female
in the intervals of Inctntion, nnd in the male at all times, the oily
matters almost entirely disappear by decomposition in the interior
of the body; since the small quantity which is discharged with the
sebaceous matter by the slcin bears only an insignificant proportion
to that whicli is introduced daily with the footl.

Tli« most important characteristic, in a physiological point of
view, of ihc proximate principles of the second class, relates to their
origin and their final deslinaliou. Not only arc they all of a purely
organic origin, making their appearance first in the interior of vege-
tables; but the sugars and the oils are formed also, to a certain ex-
tent, in the bodies of animals; contioaing to make ihcir appearance
when uo similar substances, or only an insulTicient quantity of them,
have been taken with the food. Furihcrmorc, when introduced
with the fofwl, or formed in the body and de])osited iu the tissues,
these substances do not reappear in the secretions. They, therefore,
for the most part disappear by decomposition in the interior of the
body. They paw? through a series of changes by wiiicii their es-
sential characters are destroyed; and they are finally replaced in
the circulation by other substances, which are discharged with ibe
CKcrclcd fluids.

PROXIUATE I'RINCIPLES OF THE THIRD CLASS. 79

CHAPTER IV.

PROXIMATE PRINCIPLES OF THE THIRD CLASS.

The sabstaDces belonging to this class are very important, and
form by far the greater part of the entire mass of the body. They
are derived both from animal and vegetable sources. They have
been known by the name of the " protein compounds" and the
"albuminoid substances." The name organic substances vr&a given
to them by Robin and Yerdeil, by whom their distinguishing pro-
perties were first accurately described. They have not only an
organic origin, in common with the proximate principles of the
eecond class, but their chemical constitution, their physical struc-
ture and characters, and the changes which they undergo, are all so
different from those met with in any other class, that the term "or-
ganic substances" proper appears particularly appropriate to them.

Their first peculiarity is that they are not cryatallizable. They
always, when pure, assume an amorphous condition, which is some-
times solid (organic substance of the bones), sometimes fluid (albu-
men of the blood), and sometimes semi solid in consistency, midway
between the solid and fluid cotidition (organic substance of the
muscular fibre).

Their chemical constitution differs from ihat of bodies of the
second class, first in the fact that they all contain the four chemical
elements, oxygen, hydrogen, carbon, and nitrogen ; while the
starches, sugars, and oils are destitute of the last named ingredient.
The organic matters have therefore been sometimes known by the
name of the "nitrogenous substances," while the sugars, starch, and
oils have been called "non-nitrogenous." Some of the organic mat-
ters, viz., albumen, fibrin, and casein, contain sulphur also, as an in-
gredient; and others, viz., the coloring matters, contain iron. The
remainder consist of oxygen, hydrogen, carbon, and nitrogen alone.

The most important peculiarity, however, of the organic sub-
stances, relating to their chemical composition, is that it is not
ilefinite. That is to say, they do not always contain precisely the

80 PROXIMATE PRINCIPLES OF THE THIRD CLASS.

snme proportions of oxygen, hydrogen, carbon, and nitrogen; but
the relative qiiantiiies of these elements vary within certain limits,
in diPlerent iiulividiiaU and at different limes, without modifying, in
any essential degree, the peculiar properties of the animal matters
which they uonatitute. This fact is altogether a special one, and
charactorititic of organic sulcata nces. No snbstnnco having a definite
chemical compoaiilon, like phosphate of lime, starch, or olein, can
suffer the slightest change in its ultimate constitution without being,
by that fact alone, totally altered in its essential properties. It
phosphate of lime, for example, were to lose one or two equivalcnta
of oxygen, an entire destruction of the salt would necessarily result^
and it would cense to be phosphate of lime. For its properties as a
salt depend entirely upon its ultimate cheraital constitution ; and if
the tatter be changed in any way, the former are necessarily lost.

But ihe properties which dislinguiah the organic substances, and
which make them important as ingredients of the body, do not
depend immediately upon their ultimate chemical constitution, and
are of a peculiar character; being such as are only manifested in
the interior of the living organism. Albumen, therefore, though
it may contain a few equivalents more or less of oxygen or nitrogen,
docs not on that account cease to be albumen, so long as it retains
its fluidity and its aptitude for nudcrgoing the procesjies of absorp-
tion and transformation, which characterize it ns an ingredient of
the living body.

It is for this reason that considernhle discrepancy has existed at
various times among chennsts as to the real ultimate composition
of these substances, difterent experlmentera often obtaining differ-
ent analytical results. This is not owing to any inaccuracy in the
analyses, but to the fact thai the organic substance itself really has
a different ultimate constitution at different times. The most ap-
proved formula) are those which have been established by Liebig
for the following substances: —

i-'ibrin = Cj„H,eK„0„S,

AlbDinon -- Cj„H,e,N„(J^

C"-'n = t^^ltmN^O^'*,

Owing to the above mentioned variations, however, tho samo
degree of importance does not attach to the quantitative ultimate
analysis of an organic matter, as tu that of other substances.

This absence of a deQnite chemical constitution, in tho organig sub-
alaiicea is undoubtedly connected with their incapacity for crystalli-
zation, it is also connected with another almost equally [>cculiHr

OBOANIC SUBSTANCES. 81

&ct, tIz^ tliat although the organic substances unite with acids and
vith alkalies, they do not play the part of an acid towards the base,
or of a base toward the acid; for the acid or alkaline reaction of
the sabstance employed is not neutralized, but remains as strong
after the combination as before. Furthermore, the union does not
take place, so far as can be ascertained. Id any definite proportions.
The organic substances have, in fact, no combining equivalent; and
tbeir molecular reactions and the changes which they undergo in
tbe body cannot therefore be expressed by the ordinary chemical
phrases which are adapted to inorganic substances. Their true
characters, as proximate principles, are accordingly to be sought
for in other properties than those which depend upon their exact
nltimate composition.

One of these characters is that they are hygroscopic. As met with
in difi^erent parts of the body, they present different degrees of con-
sistency; some being nearly solid, others more or less fluid. But on
being subjected to evaporation they all lose water, and are reduced
to a perfectly solid form. If after this desiccation they be exposed
to the contact of moisture, they again absorb water, swell, and
regain their original mass and consistency. This phenomenon is
quite different from that of capillary attraction, by which some in-
organic substances become moistened when exposed to the contact
of water; for in the latter case the water is simply entangled me-
chanically in the meshes and pores of the inorganic body, while that
which is absorbed by the organic matter is actually united with its
sabstance, and diffused equally throughout its entire mass. Every
organic matter is naturally united in this way with a certain quantity
of water, some more and some less. Thus the albumen of the blood
is in union with so much water that it has the fluid form, while the
organic substance of cartilage contains less and is of a firmer con-
sistency. The quantity of water contained in each organic sub-
stance may be diminished by artificial desiccation, or by a deficient
supply ; but neither of them can be made to take up more than a
certain amount Thus if the albumen of the blood and the organic
substance of cartilage be both reduced by evaporation to a similar
degree of dryness and then placed in water, the albumen will absorb
EG much as again to become fluid, but the cartilaginous substance
ouly so much as to regain its usual nearly solid consistency. Even
where the organic substance, therefore, as in the case of albumen,
becomes fluid under these circumstances, it is not exactly a solution
6

PBOSIMATB PRTNCTPLBS OP THB THIRD CLASS.
^

of it in waler, but only a reabsorption by it of tbat quantity of fluid

witli wbicli it is naturally associated.

Another peculiar pbenometion cbaracleristic of organic subf^tances
is tbcir ooa^ihtion. Those which arc naturally fluid suddenly a8>
suroe, under ceriain conditions, a solid or semi-solid consistency.
They are then said to bn coagulated ; aud ailer coajjulalion lliey
cannot bo made to resume their original condition. Thus fibrin
coagulatea on being withdrawn from the blood veaacis, albumen on
being subjected to the lemperature of boiling water, casein on being
placed iu contact with an acid. When an orgsnic substance thus
coagulates, the clmiige wbluh tnkus plucc is a peculiar one, aud has
no resemblnnce to the precipitation of a solid substance from a
watery solution. On the contrary, the organic substancu merely
assumes a special condition; and in passing into the solid form it
retains all the water with which it was previously united. Albumen,
for example, after coagulation, retains the same quntility of water in
union with it, which it held before. After coagulation, accordingly,
this water may be driven off by evaporation, in the same manner
as previously ; and on being again exposed to moisture, the organic
matter will again absorb the same quantity, though it will not re-
sumo the fluid form.

By coagulation, an organic substance is permanently altered ; and
though it may be afterwards dissolved by certain chemical ro-agcnis,
as, for example, the caustic alkalies, it is not thereby restrired to its
original condition, but only suffers a still further alteration.

In many instances we are obliged to resort to coagulation in
order to separaLo an organic substance from the other proximMe
principles with which it is associated. This is the case, for example,
with the fibrin of the blood, which is obtained in the form of floc-
ciili, by beating freshly drawn blood with a bundle of rods. But
when Bcparulcd in thi^ way, it is already in an unnatural condition,
and no longer represents exactly ilie original fluid fibrin, as it ex-
isted in the circulating blo»l. Nevertheless, this is the only mode
in which it can be examined, as there are no means of bringing it
back to its previous cuuditioTi.

Another important property of the organic substances is that
they readily excite, in other proximate principles and in each other,
those peculiar indirect chemical ciiangcs which are termed catalyses
OTcaialytic trana/orTnations. That is to say, they produce the changes
referred to, not directly, by combining with the substance which
suffers alteration, or with any of its ingredients; but simply by their

I
I
I

OROAKIC SUBSTANCES. 83

presence, which induces the chemical change in an indirect manner.
Thas, the organic sabstances of the intestinal fluids induce a cata-
lytic action by which starch is converted into sugar. The albumen
of the blood, by contact with the organic substance of the muscular
fibre, is transformed into a substance similar to it. The entire
proces of nutrition, so far as the organic matters are concerned,
consists of such catalytic transformations. Many crystallizahle
Bulstances, which when pure remain unaltered in the air, become
changed if mingled with organic substances, even in small quantity.
Thus the casein of milk, after being exposed for a short time to a
warm atmosphere, becomes a catalytic body, and converts the sugar
of the milk into lactic acid. In this change there is no loss nor
addition of any chemical element, since lactic acid has precisely the
same ultimate composition with sugar of milk. It is simply a
transformation induced by the presence of tbe casein. Oily matters,
which are entirely unalterable when pure, readily become rancid at
warm temperatures, if mingled with an organic impurity.

Fourthly, The organic substances, when beginning to undergo
decay, induce in certain other substances the phenomenon oi fer-
mentation. Thus, the mucus of the urinary bladder, after a short
exposure to the atmosphere, causes the urea of the urine to be con-
verted into carbonate of ammonia, with the development of gaseous
bubbles. The organic matters of grape juice, under similar circum-
stances, give rise to fermentation of the sugar, by which it is con-
verted into alcohol and barbonic acid.

Fifthly, The organic substances are the only ones capable of
undergoing the process of putrefaction. This process is a compli-
cated one, and is characterized by a gradual liquefaction of tbe ani-
mal substance, by many mutual decompositions of the saline matters
which are associated with it, and by the development of peculiarly
fetid and unwholesome gases, among which are carbonic acid,
nitrogen, sulphuretted, phosphoretted, and carburetted hydrogen,
and ammoniacal vapors. Putrefaction takes place constantly after
death, if the organic tissue be exposed to a moist atmosphere at a
moderately warm temperature. It is much hastened by the presence
of other organic substances, in which decomposition has already
commenced.

The organic substances are readily distinguished, by the above

general characters, from all other kinds of proximate principles.

•They are quite numerous; nearly every animal fluid and tissue

containing at least one which is peculiar to itself. They have not

as yet been all accurately described. The following list, however,

PKOXniATE PKINCIPLES OF THE THIRD CLAS8.

comprises the most important of them, and those with which we are i
at present most thorntighly acquainted. The first seven are fluid,'
or uearly so, and uilhvr colorless or of a faint yellowish tinge.

1. Fibrin, — Fibrin is found in the blood; where it exists, in thi
human subject, in the proportion of two to three parts per thousand.
It is fluid, and mingled intimately with the other ingredients of the
blood. It occur»^ also, but in much smallor quantity, in the lymph.
It is distingniahed by what is called its "spontaneous" coagulation;
that is, it coagulates un being withdniwn from the vessels, or on the
occurrence of any stoppage to the circolation. It is rather mora
abundant in the blood of some of the lower animals than in that of
the human subject. In general, it is found in larger quantity ia
the blood of the herbivora than in that of the carnivora.

2. Albumen. — Albumen occurs in the blood, the lymph, the
fluid of the pericardium, end in that of the serous cavities gene*
rally. It is also present in the fluid which may bo extracted by
pressure from the muscular tissue. In the bloo<l it occurs in the
proportion of about seventy-five parts per thousand. The while of
egg, which usually goes by the same name, is not identical with the
albumen of the blood, though it resembles it in some respects; it is
properly a secretion from the mucous membrane uf the fowl's ovi-
duct, and should bo considered as a distinct organic substance.
Albumen coagulates on being raised to the temperature of l(iO° K.;
and the coagulum, like that of all the other proximate principles, ia
soluble in cauatic poinssn. It coagnlates also by contact with alco-
hol, the mineral ncidSj ferrocyanide of potJissium in an acidulated
solution, tannin, and the inctallic salts. The alcoholic coagulum, if
separnted from the alcohol by washing, does not xedissolve in water.
A very small quantity of albumen has been sometimes found in the
saliva.

a. Casein. — This substance exists in milk, in the proportion of
about forty puns per thousand. It coagulates by coatact with all _
the acids, mineral and organic; hut is not aflectcd by a boiling I
temperature. It is coagulated also by the juices of the stomach.
It is important as an article of food, being the principal organic
ingredient in all the preparations of milk. In a coagulated form, it
constitutes the difli^rcnt varietiea of cheese, which are more or less
highly flavored with various oily matters remaining entangled in
the coagulated ca»i>in.

GLOBULINE.— HUCOSINE. 86

What is called vegetable casein or "legumioe," is diflrereut from
the casein of milk, and constitutes the organic Bubstance present in
rarioos kinds of peas and beans.

4. OLOBULiifB. — This is the organic substance forming the prin-
cipal mass of the red globules of the blood. It is nearly fluid in
its natural condition, and readily dissolves in water. It does not
dissolve, however, in the serum of the blood; and the globules,
therefore, retain their natural form and consistency, unless the
serum be diluted with an excess of water. Globuline resembles
albumen in coagulating at the temperature of boiling water. It is
said to differ from it, however, in not being coagulated by contact
with alcohol.

5. Pbpsine. — This substance occurs as an ingredient in the gas-
tric juice. It is not the same substance which Schwann extracted
by maceration from the mucous membrane of the stomach, and
which is regarded by Robin, Bernard, &c., as only an artificial pro-
duct of the alteration of the gastric tissues. There seems no good
reason, furthermore, why we should not designate by this name the
oi^anic substance which really exists in the gastric juice. It occurs
in this fluid in very small quantity, not over fifteen parts per
thousand. It is coagulable by heat, and also by contact with alco-
hol. But if the alcoholic coagalum be well washed, it is again
soluble in a watery acidulated fluid.

6. Pancreatine. — This is the organic substance of the pancreatic
juice, where it occurs in great abunddnce. It coagulates by heat,
and by contact with sulphate of magnesia in excess. In its natural
condition it is fluid, but has a considerable degree of viscidity.

7. Mdcosine is the organic substance which is found in the dif-
ferent varieties of mucus, and which imparts to them their viscidity
and other physical characters. Some of these mucous secretions
are so mixed with other fluids, that their consistency is more or less
diminished ; others which remain pure, like that secreted by the
mucous follicles of the cervix uteri, have nearly a semi-solid con-
BJstency. But little is known with regard to their other specific
characters.

The next three organic substances are solid or semi-solid in con-
sistency.

86 PROXIMATE PRINCIPLES OF THE THIRD CLASS.

8. Osteins is the organic substance of the bones, in which it is
associated with a large proportion of pkosphate of lime. It exists,
in those bones which have been examined, in the proportion of
about two hundred parts per thousand. It is this substance which
by long boiling of the bones is transformed into gelatine or glue.
In its natural condition, however, it is insoluble in water, even at
the boiling temperature, and becomes soluble only afler it has been
permanently altered by ebullition.

9. Cartilag-ine. — This forms the organic ingredient of cartilage.
Like that of the bones, it is altered by long boiling, and is converted
into a peculiar kind of gelatine termed "chondrine." Chondrine
differs from the gelatine of bones principally in being precipitated
by acids and certain metallic salts which have no effect on the latter,
Cartilagine, in its natural condition, is very solid, and is closely
united with the calcareous salts.

10. MuscDLlNE. — This substance forms the principal mass of the
muscular fibre. It is semi-solid, and insoluble in water, but soluble
in dilute muriatic acid, from which it may be again precipitated by
neutralizing with an alkali. It closely resembles albumen in its
chemical composition, and like it, contains, according to Soberer,
two equivalents of sulphur.

The four remaining organic substances form a somewhat peculiar
group. They are the cohring matters of the body. They exist
always in small quantity, compared with the other ingredients, but
communicate to the tissues and fluids a very distinct coloratioo.
They all contain iron as one of their ultimate elements.

11. H^HATINE is the coloring matter of the red globules of the
blood. It is nearly fluid like the globuline, and is united with it
in a kind of mutual solution. It is much less abundant than the
globuline, and exists in the proportion of about one part of hsBma-
tine to seventeen parts of globuline. The following is the formula
for its composition which is adopted by Lehmann: —

Enmatine = C^^Bt^fi^Fe.

When the blood-globules from any cause become disintegrated, the
hsmatine is readily imbibed afler death by the walls of the blood-
vessels and the neighboring parts, staining them of a deep red
color. This coloration has sometimes been mistaken for an evidence

HELANl!rE.— UB03ACINS. 87

of arteritis; but is really a simple effect of post-roortera imbibition,
as above stated.

12. Mklanine. — This is tbe blackisb-brown coloriog matter
whicb is found in the choroid coat of the eye, the iris, the hair, and
more or less abundantly in the epidermis. So far as can be ascer-
tained, tbe coloring matter is the same in all these situations. It is
very abundant in the black and brown races, less so in the yellow
and white, but is present to a certain extent in all. Even where
the tinges produced are entirely different, as, for example, in brown
and blue eyes, the coloring matter appears to be the same in cha-
racter, and to vary only in its quantity and the mode of its arrange-
ment; for the tinge of an animal tisane does not depend on its
local pigment only, but also on the muscular fibres, fibres of areolar
tissue, capillary bloodvessels, &c. All these ingredients of the
tissue are partially transparent, and by their mutual interlacement
and superposition modify more or less the effect of the pigment
which is deposited below or among them.

Melanine is insoluble in water and the dilute acids, but dissolves
slowly in caustic potassa. Its ultimate composition resembles that
of hsematine, but the proportion of iron is smaller.

13. BlLTVERDlNB is the coloring matter of the bile. It is yellow
by transmitted light, greenish by reflected light On exposure to
the air in its natural fluid condition, it absorbs oxygen and assumes
a bright grass green color. The same effect is produced by treating
it with nitric acid or other oxidizing substances. It occurs in very
small quantity in the bile, from which it may be extracted by pre-
cipitating it with milk of lime (Robin), from which it is afterward
separated by dissolving out the lime with muriatic acid. Obtained
in this form, however, it is insoluble in water, having been coagu-
lated by contact with the calcareous matter; and is not, therefore,
precisely in its original condition.

14. ITrosacine is the yellowish red coloring matter of the urine.
It consists of the same ultimate elements as the other coloring mat-
ters, but occurs in the urine in such minute quantity, that the
relative proportion of its elements has never been determined. It
readily adheres to insoluble matters when they are precipitated from
the urine, and is consequently found almost always, to a greater or
less extent, as an ingredient in urinary calculi formed of the urates

PROXIMATE PRIN0TPLE9 OF THB THIttD CLASS.

or of uric auid. Wben tlio uratua are thrown down also in tlie form

of a powder, as a urinary deposit, they are usually colored more or
less deeply, according to the quantity of urosacine which is preci-
pitated with them.

The organic substances which exist in tho body require for their
production un abundant supply of similar substances in the food.
All highly nutritions articles of diet, therefore, contain more or less
of these substances. Still, though nitrogenous matters must be
abundantly supplied, under tsDnie form, from without, yet the par-
ticular kinds of organic substances, charactcriatic of the tissues, are
formed in the body by a iransfonnation of thuso whicli are intro-
duced with the food. The organic matters derived from vegetables,
though similar in their general characters to thoae existing in the
animal bwly, are yet specifically diflerenl. The gluten of wheat,
the legumine of peas and beans, are not the same with animal albu-
men and fibrin. The only organic substances taken with animal
food, as a general rule, are the albumen of eggs, the casein of milk,
and the musculiuc of flesh; and even thu^c, in tho food of the
human spooies, are so altered and coagulated by the process of
cooking, as to lose their specific characters before being introduced
into the alimentary canal. They are still further changed by the
process of digestion, and are absorbed under another form into the
blood. But from their subsequejit mctamorplmaes there arc formed,
in the diS'erent parts of the body, ostcine, carlilagine, ha^matine,
globuline, and all the other varieties of organic matter that cha-
racteriise tho difierent tissues. These varieties, therefore, originate
as such in the animal economy by tho catalytic changes which the
ingredients of the blood undergo in nutrition.

Only a very smalt quantity of organic matter is discharged
with the excretions. The coloring matters of the bile and urine,
and the mucus of the urinary bladder, are almost the only ones
that find an exit from the body in this way. There is a minute
qunritity of organic matter exhaled in a volatile form with the
breath, and a little also, in all probability, from the cutaneoua sur-
face. But tho entire quantity so discharged bears but a very small
proportion to that which ia daily introduced with the food. The
organic suKstanccs, therefore, arc decomposed in the interior of the
body. They are transformed by the process of destructive assimi-
lation, and their elements are fioally eliminated and discharged
under other forma of combination.

OF FOOD. 89

CHAPTER V.

OP POOD.

Under the term "food" are included all those substances, solid
and liquid, which are necessary to sustain the process of nutrition.
The first act of this process is the absorption from without of all
those materials which enter into the composition of the living frame,
or of others which may be converted into them in the interior of
the body.

The proximate principles of the first class, or the "inorganic
aubstances," require to be supplied in sufficient quantity to keep up
the natural proportion in which they exist in the various solids and
fluids. As we have found it to be characteristic of these substances,
except in a few instances, that they suffer no alteration in the in*
terior of the body, but, on the contrary, are absorbed, deposited in
itsiiasue, and pass out of it aflerward unchanged, nearly every one
of them requires to be present under its own proper form, and in
sufficient quantity in the food. The alkaline carbonates, which
are formed, as we have seen, by a decomposition of the malates,
citrates and tartrates, constitute almost the only exception to this
rule.

Since water enters so largely into the composition of nearly every
part of the body, it is equally important as an ingredient of the
food. In the case of the human subject, it is probably the most
important substance to be supplied with constancy and regularity,
and the system suffers more rapidly when entirely deprived of
fluids, than when the supply of solid food only is withdrawn. A
man may pass eight or ten hours, for example, without solid food,
and suffer little or no inconvenience; but if deprived of water for
the same length of time, he becomes rapidly exhausted, and feels
the deficiency in a very marked degree. Magendie found, in his
experiments on dogs subjected to inanition,' that if the animals

> Compteg Rendns, vol. xiif. p. 256.

'OOD.

were suppHed with wntcr alone tlicy liveil six, eight, and even ten
days longer than if they were depri?ed at the same time of both
solid and liquid food. Chloride of sodium, also, is usually added
to the food in considcrablo quiiutity, and roquirea to bo supplied
with tolerable regularity; but the remaining inorganic maleriuls,
such as calcareous aaltfi, the alkaline phosphatc^i, &c., occur oata-
rally id sufficient quantity iu most of the articles which are used as
food.

The proKimate principles of the second class, so far as they con-
stitute ingredients of the food, are naturally divided into two
groups : Ist, the sugar, and 2d, the oily matters. Since starch is
iilways converted iuto sugar iu the process of digesliou, it inny be
included, as an alimetitary substance, in the same group with the
sugars. There is a natural dcstro in the human species for both
saccharine and oleaginous food. In the purely carnivorous animals,
however, though no starch or Bugar be taken, yet the body is main-
tained in a healthy condition. It has been supposed, therefore, that
saccharine matters could not be absolutely nece6.<»ry ns food; the
more so since it has been found, by the experiments of CI. Bernard,
that, in carnivorous animals kept exclusively on a diet of £esb,
sugar is still formed in the liver, as well a» in the mammary gland.
The above conclusion, however, which has Lmjuu drawn from these
facts, docs not apply practically to the human s[)ecics. The car-
nivorous animals have no desire for vegetable food, while in the
human s|]ecies there is a natural craving for it, which is almost
universal. It niay be dispensed with for a few days, but not with
impunity fur any great length of time. The experiment has often
enough been tried, iu the treatment of diabetes, of confining th«
patient to a strictly animal diet. It has been invariably found that,
if this regimen be continued for some weeks, the desire for vegetable
food on the part of the patient beeumes so imperative that the plan
of treatment is unavoidably nbanduncd.

A similar question has also arisen with regard to the oleaginous
matters. Are these substances indispensable as ingredients of the
food, or may they be replaced by other proxiiuala priuciples, such
as starch or sugar? It has already been seen, from the experiments
of Bousstngault and others, that a certain amount nf fat is produced
in the body over and above that which is taken with the food ; and
it appears also that a regimen abounding in saccharine substances
IB favorable to the production of fat. It is allugether probable,
therefore, that the materials for the production of fat may he

OF FOOD. 91

derived, under these circumstances, either directly or indirectly
from saccharine matters. But saccharine mutters alone are not
entirely sufficient M. Huber' thought he had demonstrated that
bees fed on pure sugar would produce enough wax to show that
the sugar could supply all that was necessary to the formation of
the fatty matter of the wax. Dumaa and Milne-Edwards, however,
in repeating Huber's experiments,' found that this was not the case.
Bees, fed on pure sugar, soon cease to work, and sometimes perish
in considerable numbers; but if fed with honey, which contains
some waxy and other matters beside the sugar, they thrive upon
it; and produce, in a given time, a much larger quantity of fat than
was contained in the whole supply of food.

The same thing was established by Boussingault with regard to
starchy matters. He found that in fattening pigs, though the
qnanlity of fat accumulated by the animal considerably exceeded
that contained in the food, yet fat must enter to some extent into
the composition of the food in order to maintain the animals in a
good condition ; for pigs, fed on boiled potatoes alone (an article
abounding in starch but nearly destitute of oily matter), fattened
slowly and with great difficulty; while those fed on potatoes mixed
with a greasy fluid fattened readily, and accumulated, as mentioned
above, much more fat than was contained in the food.

The apparent discrepancy between these facta may be easily ex-
plained, when we recollect that, in order that the animal may become
fattened, it is necessary that he be supplied not only with the
materials of the fat itself, but also with everything else which is
necessary to maintain the body in a healthy condition. Oleaginous
matter is one of these necessary substances. The fats which are
taken in with the food are not destined to be simply transported
into the body and deposited there unchanged. On the contrary,
they are altered and used up in the processes of digestion and
nutrition; while the fats which appear in the body as constituents
of the tissues are, in great part, of new formation, and are produced
from materials derived, perhaps, from a variety of different sources.

It is certain, then, that either one or the other of these two
groups of substances, saccharine or oleaginous, must enter into the
composition of the food ; and furthermore, that, though the oily
matters may sometimes be produced in the body from the sugars,

' Nataral Historj of Bees, Edlnboro', 1821, p. 330.

' Aonalea de Chim. et de Pbys., 3d series, rol. zIt. p. 400.

OP FOOD.

it is also necessary for the perfect nutrition of the body that fat
supplied, under its own form, with the food. For the human
species, alao, it is natural to have lliem both associated in the
alimentary materiiils. Tbey occur together iti most vegetable sub-
stances, and there is a natural deeira for them both, as elements of
the food.

They are not, however, when alone, or even associated with each
other, sufficient fur the nutrition of the animal body. Mageudie
found that dogs, fed exclusively on starch or sugar, perished after a
short time with symptoms of profound disturbance of the DutnttTfl
functions. An exclusive diet of butter or lanl had a similar eSeot
The animal became exceedingly debilitated, though without much
emaciation; and oftt^r death, all the iuternal organs and tissues
were found infiltrated with oil, Bouasingault' jierformed a similar
osperinient, with a like result, upon a duck, whioli wafl kept upon
an exclusive regimen of butler. "The duck received 1359 to 1500
grains of butter every day. At the end of three weeks it died of
inani'timt. The butter ouzed from every part of its body. The
feathers looked ns though ihcy had been steeped in melted butter,
and the body exhaled an unwholesome odor like that of butyric
acid."

Lehmaan was also led to the same result by some experiments
which he performed upon himself for the purpossof ascertaining
the eflecl produced on the urine by different kinds of food.*
Thia observer confined himself first to a purely animal diet for
three weelu, and afterwardit U) a purely vegetable oue for sixteen
{lays, without suffering any marked inconvenience. lie then put
himself upon a regimen consisting entirely of non-nitrogenous sub-
stances, starch, sugar, gum, and oil, but was only able to continue
this diet for two, or at most for three days, owing to the marked
disturbance of the general health which rapidly supervened. The
unpleasant symptoms, however, immediately disappeared on his
return to an ordinary mixoii diet. The same fact has been esta<
Wished more recently by Prof. Wm. A. IlammoDd,' in n series of
experiments which he performed upon himself. He was euabled
to live for ten days on a diet composed exclusively of boiled starch
and water. Afler the thinl day, however, the general health began

I Cliiini(t AgriootB, p. ISB.

' Joamal fUr pfAktiacha Chemlo, rol. xxrii, p. 2.17.

* Bzpnrimontjtl RwiaaTches, &e., being the rr'me Kstaj of Ili« Aiaerivatl M«d[c«I
Anoolatlon Car \K^.

OF FOOD. 88

to deteriorate, and became very much disturbed before the termi-
cation of the experiment. The prominent symptoms were debility,
headache, pyrosis, and palpitation of the heart. After the starchy
diet was abandoned, it required some days to restore the health to
its usual condition.

The proximate principles of the third class, or the organic sub-
stances proper, enter so largely into the constitution of the animal
tissues and fluids, that their importance, as elements of the food, is
easily understood. No food can be long nutritious, unless a certain
proportion of these substances be present in it. Since they are so
abundant as ingredients of the body, their loss or absence from the
food is felt more speedily and promptly than that of any other sub-
stance except water. They have, therefore, sometimes received the
name of "nutritious substances," in contradistinction to those of
the second class, which contain no nitrogen, and which have been
found by the experiments of Magendie and others to be insufficient
for the support of life. The organic substances, however, when
taken alone, are no more capable of supporting life indefinitely than
the others. It was found in the experiments of the French "Gela-
tine Commission"' that animals fed on pure fibrin and albumen, as
well as those fed on gelatine, become after a short time much en-
feebled, refuse the food which is offered to them, or take it with
reluctance, and finally die of inanition. This result has been
explained by supposing that these substances, when taken alone,
excite after a time such disgust in the animal that they are either
no longer taken, or if taken are not digested. But this disgust
itself is simply an indication that the substances used are insufficient
and finally useless as articles of food, and that the system demands
instinctively other materials for its nourishment.

The instinctive desire of animals for certain substances is the
snreat indication that they are in reality required for the nutritive
process; and on the other hand, the indifference or repugnauce
manifested for injurious or useless substances, is an equal evidence
of their unfltnws as articles of food. This repugnance is well de-
scribed by Magendie, in the report of the commission above alluded
to, while detailing the result of his investigations on the nutritive
qualities of gelatine. "The result," he says, "of these first trials
was that pure gelatine was not to the taste of the dogs experimented
on. Some of them suffered the pangs of hunger with the gelatine

< Comptea Reudos, 1841, vol. xiii. p. 267.

OF FOOD.

within their reach, and would not toach it; others tasted of it, Ijut
would not eat ; others alill devoured a certain <]uantily of it once
or twice, and then obstinately refused to make any further use of iU"

In one instance, however, Magcndie succeeded in inducing a dog
lo take n considerable quimtity of pure fibrin dnily throughout the
whole course of the experiment; but notwitlisiandiiig this, the
ftnimal became eomeiated like the others, and died at last with the
same symptoms of inanition.

The alimentary substances of the aecond class, however, viz., the
Bugnra and the oils, have been aometimea thought less important
than the albaminous matters, because they do not enter so largely
or EO permanently into the compusitioti of the solid tissues. The
saccharine matters, when taken as food, cannot be truccd farther
than the blood. They undergo already, in the circulating fluid,
somo change hy which their essential character is lost, and they
cannot bo any longer recognized. The appearance of sugar in the
niammary gland and the milk is only exceptional, and does not
occur nt all in the male subject. The faLs are, it is true, very gene-
rally distributed throughout the body, but it ie only in the brain
and nervous matter that they exist intimately united with ihtt re>
maining ingrcdlentKof the tissues. Elsewhere, as already mcntionod,
they are deposited in distinct drops and granules, and so long as
thoy remain in this condition must of course be inactive, so far as
regards any chemical nutritive process. In this condition they
seem to be lield in reserve^ ready to be absorbed by the blood,
whenever they may be retjuircd for the purposes of nutrition. On
being reabsorbed, however, as soon as they again enter the blood
or unite intimately with the substance of the tissues, they at onoe
change their condJliou and lose their former chemical constitution
and propertiea.

It is for these reasons that the albuminoid matters have been
sometimes considered as the only "nutritious" HHbstance.% because
they alone constitute under their own form a great part of the
ingredients of the tissues, while the sugars and the oils rapidly dis*
appear by decomposition. It has even been assumed that the pro-
cess by which the sugar and the oils disappear is one of direct
combustion or oxidation, and that they are destined solely lo be
consumed in this way, not to enter at all into the composition of
the tissues, but only to maintain the heat of the body by an inces-
sant process of cumbustion in the blood. They have been therefore
termed the "combustible" or "heat-producing"' elements, while tha

OF FOOD. 96

albuminoid substances were known as tbe nutritious or "plastic"
elements.

This distinction, however, has no real foundation. In the first
place, it is not at all certain that tbe sugars and the oils which dis-
appear in the body are destroyed by combustion. This is merely
an inference which has been made without any direct proof. All
we know positively in regard to the matter is that these substances
soon become so altered in the blood that they can no longer be
recognized by their ordinary chemical properties; but we are still
ignorant of the exact nature of the transformations which they
nndergo. Furthermore, the difference between the sugars and the
oils on the one hand, and the albuminoid substances on the other,
so far as regards their decomposition and disappearance in the
body, is only a difference in time. The albuminoid substances
become transformed more slowly, the sugars and the oils more
rapidly. Even if it should be ascertained hereafter that the sugars
and tbe oils really do not unite at all with the solid tissues, but are
entirely decomposed in tbe blood, this would not make them any
less important as alimentary substances, since the blood is as
essential a part of the body as the solid tissues, and its nutrition
roust be provided for equally with theirs.

It is evident, therefore, that no single proximate principle, nor
even any one class of them alone, can be sufficient for the nutrition
of the body ; but that the food, to be nourishing, ntust contain
substances belonging to all the different groups of proximate prin-
ciples. The albuminoid substances are first in importance because
they constitute the largest part of the entire mass of the body; and
exhaustion therefore follows more rapidly when they are withheld
than when the animal is deprived of other kinds of alimentary
matter. But starchy and oleaginous substances are also requisite;
and the body feels the want of ihem sooner or later, though it may
be plentifully supplied with albumen and fibrin. B'inally, the ia-
organic saline matters, though in smaller quantity, are also neces-
sary to the continuous maintenance of life. In order that the
animal tissues and fiuids remain in a healthy condition and take
their proper part in the functions of life, they must be supplied
with all the ingredients necessary to their constitution ; and a man
Diay be starved to death at last by depriving him of chloride of
sodium or phosphate of lime just as surely, though not so rapidly,
as if he were deprived of albumen or oil.

In the different kinds of food, accordingly, which have been

96 or POOD.

adopted bj the universal and instinctive choice of man, the three
different classes of proximate principles are all more or less abund-
antly represented. In all of them there exists naturally a certain
proportion of saline substances; and water and chloride of sodium
are generally taken with them in addition. In milk, the first food
supplied to the infant, we have casein which is an albuminoid
substance, butter which represents the oily matters, and sugar of
milk belonging to the saccharine group, together with water and
saline matters, in the following proportions: — '

COXFOSITIOR OF CoW'B HILK.

Water 87.02

Casein 4.48

Butter 3.13

Sagar of milk 4.77

Soda

ChlorideB of potaaBinm and sodium

PhosphateB of soda and potaasa

PhoBpliate of lime ^ 0.60

" magnesia

Alkaline c&rbonates

Iron, &o

100.00

In wheat flour, gluten is the albuminoid matter, sugar and starcli
the non-U itrogenoua principles.

CoMPOBtTion OP Wheat Floor,
Glaten .... 10.2 Gum .... 2.8

SUrch .... 72.8 Water .... 10.0

Sugar . . . .4.2

100.0

The other cereal grains mostly contain oil in addition to the
above,

CojiPosiTios OP Dbisd Oatmbal.

StaroU 59.00

Bitter matter and sagar 8.25

Oray albuminous matter 4.30

Fatty oil 2.00

Gum 2.50

Husk, mixture, and loss 23.95

100.00

Eggs contain albumen and salts in the white, with the addition
of oily matter in the yolk.

' Tlie accompanying analyttes of various kindd of food are taken from Peretra
on Food anil Di».t, New York, 1843.

OF POOD. 97

CoHPosmox or Boas.

WhlU or Kw. Tolk of %s.

Water .... 60.00 S3.78

Albnm«& and maciu 15.28 12.75

Yellow oil 28.7fi

Salta .... 4.72 4.72

100.00 lOO.OO

In ordinary flesh or butcher's meat, we have the albuminoid
matter of the muscular fibre and the fat of the adipose tissue.

CoHPogmoir or Ordihaht Bdtchbb'b Hsat.

w . J i^ f f . nr T ( Water .... 63.418

Heat devoid of lilt 85.7 !„.,, „„ „„„

iSolidtnattar . . . 22.282

Pat, eellalar tissue, Ac 14.300

100.000

From what baa been said above, it will easily be seen that the
nutritious character of any substance, or its value as an article of
food, does not d^end simply upon ita containing either one of the
alimentary substances mentioned above in large quantity; but upon
its containing them mingled together in such proportion as is
requisite for the healthy nutrition of the body. What these pro-
portions are cannot be determined from simple chemical analysis,
nor from any other data than those derived from direct observation
and experiment.

The total quantity of food required by man has been variously
estimated. It will necessarily vary, indeed, not only with the con-
stitution and habits of the individual, but also with the quality of
the food employed; since some articles, such as corn and meat, con-
tain very much more alimentary material in the same bulk than
fresh fruits or vegetables. Any estimate, therefore, of the total
quantity should state also the kind of food used; otherwise, it will
be altogether without value. From experiments performed while
living on an exclusive diet of bread, fresh meat, and butter, with
coffee and water for drink, we have found that the entire quantity
of food required during twenty-four hours by a man in full health,
and taking free exercise in the open air, is as follows: —

Meat 16 oances or 1.00 lb. Avoiidapois.

Bread 19 " " 1.19 "

Butter or fet . .3* " " 0.22 " "

Water 62flnidox. " 3.38 " "

That is to say, rather less than two and a half pounds of solid food,
and rather over three pints of liquid food.

OP FOOD.

Another necessary consideration, in estimating the value of any
substance as an article of food, is its digestibility. A vegetable or
animal tissue may contain an abundance uf albuminoid or starchy
matter, but may be at the same time of such an unyielding consist-
ency as to be insoluble in the digestive fluids, and therefore useless
as an article uf food. Bones and cartilages, and the fibrea of yellow
elastic tissue, are. indigestible, and therefore not nutritious. The
flame remark may be rnado with regard to the riubstanees contained
in woody fibre, and the hard coverings and kernels of various fruits.
Everything, accordingly, which softens or disintegrates a hard ali-
mecitary substance renders it more digestible, and so far increases
its value as an article uf food.

The preparation of food by cooking has a twofold object : first,
to soften or disintegrate it, and second, to give it an attractive
flavor. Many vegetable substances are so hard as to be entirely
indigestible in a raw state. Kipe peas and beans, the differeut kinds
of grain, and many roots am) fruits, require to be soflencd by boil-
ing, or some other culinary process, before they 6^0 ready for use.
With them, the principal change produced by cooking is an altera-
tion in conaislCDcy. With most kinds ofanimal food, however, the
effect is somewhat diflerent. In the case of muscular flesh, for ex-
ample, the muscular fibres themselves are almost always more or
leas hardened by boiling or roasting; but, at the same time, the
fibrous tissue by which they are held together is golaiinized and
softened, so that the muscular fibres are more easily separated from
each other, and more readily attacked by the digestive fluids. But
beside this, the organic substances contained in meat, which are all
of them very insipid in the raw state, acquire, by the action of heat
in cooking, a peculiar and agreeable flavor. This flavor excites
the appetite aud stimulates the How of the digestive fluids, aud
readers, in this way, the entire process of digestion more easy and
cxpoilitiouB.

The changes which the food undergoes in the interior of the body
may be included under three different heads: first, digestion, or the
preparatiuu of the food in the alimentary cunul; second, lissimilationy
by which the elements of the food are converted into the animal
tissues; and third, excretion, by which they are again decomposed,
and finally discharged from the body.

DIGESTION'. 99

CHAPTER VI.

DIOE8TI0N.

DiGKanoN is that process by which the food is redaced to a form
in which it can be absorbed from the intestinal canal, and taken up
hy the bloodvessels. This process does not occur in vegetables.
For vegetables are dependent for their nutrition, mostly, if not
entirely, upon a supply of inorganic substances, as water, saline
matters, carbonic acid and ammonia. These materials constitute
the food upon which'plants subsist, and are converted in their inte-
rior into other substances, by the nutritive process. These mate-
rials, farthermore, are constantly supplied to the vegetable under
SQch a form as to be readily absorbed. Carbonic acid and ammonia
exist in a gaseous form in the atmosphere, and are also to he found
in solution, together with the requisite saline matters, in the water
with which the soil is penetrated. All these substances, therefore,
are at once ready for absorption, and do not require any preliminary
modification. But with animals and man the case is different.
Tliey cannot subsist upon these inorganic substances alone, but
require for their support materials which have already been organ-
ized, and which have previously constituted a part of animal or
vegetable bodies. Their food is almost invariably solid or semi-solid
at the time when it is taken, and insoluble in water. Meat, bread,
fruits, vegetables, Sk., are all taken into the stomach in a solid and
insoluble condition; and even those substances which are naturally
fluid, such as milk, albumen, white of egg, are almost olways, in
the human species, coagulated and solidified by the process of cook-
ing, before being taken into the stomach.

In animals, accordingly, the food requires to undergo a process
of digestion, or liquefaction, before it can be absorbed. In all cases,
the general characters of this process are the same. It consists
essentially in the food being received into a canal, running through
the body from mouth to anus, called the "alimentary canal," in
which it comes in contact with certain digestive fluids, which act

DIOESTIOX.

Upon it in aucb n way as to liquefy and dissolve it. Tbeae fluids
are secreted by the mucoua raembrftncof the alimentary canal, and
by certain glandular organs situated in its neighborhood. Since the
food always coaaisls, as we have already seen, of a mixture of vari-
ous substanees, having diflerent physical and chemical properues,
tho several digestive fluids arc also dillerent from each other; each
one ot them exerting a peculiar action, which is more or leas con-
fined to particular species of food. As the food pasaes through the
intestine from above downward, those parta of it which become
liquefied are successively removed by absorption, and taken up by
the vessels; while the remaining portions, consisting of the indi-
gestible matter, together with the refuse of the intestinal secretions,
gradually ncquire a firmer consistency owing to the absorption of
the fluids, and are finully discharged from the ititcstine under the
form of feces.

In different speciea of animals, however, the difference in their
habits, in the constitution of their tissues, and in the character of
their food, is accompanied with a corresponding variation in the
anatomy of the digestive apparatus, and tht; character of the secreted
flaids. As a general rule, the digestive apparatus of herbivoroaa
flnimnls is more complex thnn that of the carnivora; since, in vege-
table substances, the nutritious matters are often present in a very
solid and unmanageable form^ as, for example, in raw starch and
the cereal grains, and are nearly always entangled among vegetable
cells and fibres of an indigcsiible character. In those instances
where the food consists mostly of herbage, as grass, leaves, &c., the
digestible matters bear only a small proportion to tho entire quan-
tity; and a large mass of food must therefore be taken, in order
that the requisite aniount of nutritious material may bo extracted
from it. In such cases, ncuordingly, the alimentary canal is large
and long; and is divided into many coropartmenta, In which
different processes of disiutegratlou, tranisforuiatiou, and solution
are corried on.

In the common fowl, for instance (Fig. 1()), tlio food, which con-
sists mostly of grains, and frequently of insects with hard, coria-
ceous integument, first passes down the ccsopbagua (a) into a
diverticulum or pouch (b) termed the crop. Here it remains for
u time, mingled with a watery secretion in which the grains are
macerated and softened. The food \a then carried fjirthcr down
until it reaches a second dilatation (c), the proventriculus, or
secreting stomach. The mucoua membrane here is thick and

DIOBBTtoy.

101

glandular, and is provided wiih numerous ae- *^8* l"-

|Creling foUicIefl or crypta. From ihem nn

'»cid 6oid is poured out, by which tlie food is

isabjected to further changes. It next passes

[into iho gizzard (c£), or trituraLinji^ stomach, n
CRTitj inclosed by thick, muscular walls, and

[lined with a remarkably totigh and horny

t«pitbolium. Here it is subjected lu the crush-
ing and grinding action of the muscular pa-
rietes, assisted by grains of sand and gmvel,

^which the animal iuatinctivcly swallows with
the food, by which it is so triturated and di«-
int^rated, that it is reduced toa uniform pulp,

■-Bpou which the digestive fluids can effectually
Operate. The mass then passes Into the inies*
tine (e), where it meets with the intestinal

^iccs, which complete the process of solution; /|
and from the intestinal cavity it is Gnally ab-
sorbed in a liquid form, by the vessels of the
mucouif membrane.

la tfa« oXf again, the sheep, the camel, the
deer, and all ruminating animals, there aro
tour distinct stomachs through which tho
(bod passes in succession; each lined with
mocous membrane of a diOerent structure,
and adapted to ]>crfcrm a difterent part in
the digestive process. (Fig. 17.) When 6rat

Itwallowed, tho food is received into the m- r/'"""~,f *^'"*'"-
tneri, or paunch (t), a large sac, itself par- ..rwff«iiiii,.ii>inK>b, </ gu-
tially divided by incomplete partitions, and TtZTTj^ZZt.
lined by a mucous membrane thickly sot
with long prominences or villi. Here it ac-
cnmulates while the animal is feeding, aad is
n:tained and macerated in its own Buiils. When the animal has
finished browsing, and the process of rumination commences, the
food IB regurgitated into the mouth by an inverted action of the
muscularwalUof the paunch uud wsophagus, and slowly masticated.
It then descends again along the oraophagus; but instead of enter-
ing the first stomach, as before, it is turned ofi' by a muscular valve
into the second stomach, or reticulum (c), which is distinguished
by the intersecting folds of its [nucoas membrane, which give it

ALIMHMTtaT CAVII.

cs) lul«*'whlch optD Into iba
InMilInc ■ «liiin dUMOM
aboTO ll* ■•rnilDUloD,

102

mOESTIOX.

ft honey-combed or reticulalod appearance.

triturnttid
Kg. 17.

CeiCMiCV* ilT«a4i'll np Os.— a. (Km-

pbftgnt. b, Ttt,m*-a, or fir>i tcotakch. e. K«tl-
cnlani. oriiMuiid. d, Omuu*, ur llilnl. «. AIhi-
ni>«ui, urhiorlh, /. DoodpuniD. (From Rjnior
JoB««.)

Here ihe food, already
in tlie mouth, and
inixenl with the saliva, is further
macerated in the fluids swallowed
by the animnl, which always ac-
cumulate in considerable qaan-
tity in the reticulum. The next
cavity is the omaaus, or " paalte-
rium" ((/), in which the mucous
menibraoe is arranged in longi-
tudinal folds, alternately broad
and narrow, lying parallel with
each other, like the leaves of a
book, eo that the extent of mucous
surface, brought ia contact with
iho food, is very much increased.
The exit from this cavity leads
directly into the abomaetuij or
"rennet" (e), wliich is the troe
digestive stomach, in which the mucous mcinhranc w softer, thicker,
and more glandular than elsewhere, and in which an acid and
highly solvent fluid is secreted. Then follows the ioteatinal canal
with its various divisions and variations.

In the carnivcra, on the other hand, the alimentary canal is
shorter nnd narrower than in the preceding, and presents fewer
complexities. The food, upou which these animals subsist, is sol^r
than that of the herbivora, and less encumbered with indigestible
matter; so that the procesit of its solution requires a less extensiye
apparatus.

In the human species, the food is naturally of a mixed cha*
racter, containing both animal and vegetable substances. But the
digestive apparatus in man resembles almost exactly that of the
carnivora. Kor the vegetable matters which we take as food are,
in the first place, artificially separated, to a great extent, from indi-
gestible inipiirities; and secondly, they are so softened by the
process of euoking as to become nearly or quite as easily digestiblfl
as animal substances.

In the human species, however, the process of digestion, tbough
simpler than in the herbivora, is still complicated. The altmcDtary
canal is here, also, divided into diJTerent compartments or cavities,
vhich communicate with each other by narrow orifices. At its

I
I

DIOBSTIOir.

108

'rj

cominenoement (Fig. 18), we finO the cavity of the mouth, which is

guarded at its posterior extremity by the muscular valve of the

itthtnus of the faacea.
[Through the pharynx and
IcesophaguB (n), it commu-
ites with the second
tpartmeat, or the ato-
laeA (b\ a flafk-shapud
jrdtlntAtion, which is guarded

II the cardiao and pyloric
foriHccB by circular bnnds
muscalar fibres. Then
' comes the imall inleatine (f),

diflbrent parts of which,

ovfing to the varying atruc-

lare of their raucous mem-
branes, have received the

different names of dnode-

num, jejunum, and ileum.

Id the duodenum, we have

ibe orifices of the biltart/
Ijftnd pancreatic ducts (_/^ 3).

finally, wc have the large

pttattne (A, t,_;", k\ separated

from the smaller by the

fleo-c£ecal valve, and ter-
minating, at its lower ex-
tremity, by the ftnaj», at

which ia situated a double

sphincter, for the purpose

of guarding ite orifice.

Everywhere the alimentary

canal is composed of a

raacouB membrane and a
.piuscQlar coat, with a layer

of submucous nreulur tissue

between the two. The mua*

cular oont is everywhere

composed of a double layer of longitudinal and transverse fibros,

by the alternate contraction and relaxation of which the food is

carried through the canal from above downward. The mucous

-^^V

V-

UVN«)I ALIKIITlNt CkHAt. — a. CB««titnfii*.
b. muoiiuib. e. CArdliu arlBm d. I'jrkrut. c HaiaU
lBla*t>n*. /. llllliT/ dapl. f l^iiienaUo •lucl h ,\t.
MDdliil colon. 1. Tnuirane calon. /. ifHeendtnc tv-
lus. Jr. Reclum.

104

DIOKBTION.

membraiifi presents, also, a ditTereiit stractore, and has different
properties in different parts. In tUe mouth and cesopbagus, it ia
sinooth, with a hard, whitish, and tessellated epithelium. This kind
of epithelium tenniiiates abruptly at the cardiaa orifice of the
stomach. The mucous raembranc of the gastric cavity is soft and
gUudular, covered with a transparent, coluiunar epitheliuos, and
thrown into minute folds or projections on its free Hurfaoe, which
are sometimes reticulated with each other. In the small intestine,
we find Urge transverse folds of mucous membrane, the valvula
connhenlctf the minute viUosities which cover its surface, and the
peculiar glandular atruuturea which it contains. Finally, in the
large intestine, the mucous membrane is again difterent. It is hero
smooth and shining, free front viUosities, and provided with a dif-
ferent glandular apparatus.

Furthermore, the digestive secretions, also, vary in these different
regions. In its passage from above downward, the food meets
with no less than five different digestive fluids. First it meets with
the salivn in the cavity of the mouth; second, with the gastric Juice,
in the stomach; third, with the iiVe; fourth, with the pancreatK
Jiuid; find fifth, with the inteatinal juice. It is the most important
cliaracteristic of the proceiw of digestion, as established by modern
researches, that different elements of the food are digested in different
parts of the alimentary cniin? hg the agency of different digestive Jluida.
By tbeir action, the various ingredients of the alimentary mass are
successively reduced to a fiuid condition, and are taken up by the
vessels of the intestinal mucous membrane.

The action which is exerted upon the food by the digestive
fluids is not that of a simple chemical solution. It is a transforma-
tion, by which iho ingredients of the food aru altered in character
at the same time that they undergo the process of liquefaetioa.
The uctive agent in producing this change is in every instance an
organic matter, which enters as an ingredient into the digestive
fluid; and which, by coming in contact with the food, eicerts upon
it a catalytic action, and transforms \\s ingredients into other sub-
stances. It 13 these newly formed aubaiaoces which are finally
absorbed by the vessels, and mingled with the general current of
the circulation.

In our study of the process of digestion, tho different digestive
fluids will be examined separately, and their action on the aliment-
ary substances in the difi'ereut regions of the digestive apparatus
successively investigated.

MASTICATION. 103

Mastication. — In the first division of the alimentary canal, viz.,
the mouth, the food undergoes simultaneously two different opera-
tioDS, viz., mastication and insalivation. Mastication consists in
the catting and trituration of the food by the teeth, by the action
of which it la reduced to a state of minute subdivision. This pro*
ceas is entirely a mechanical one. It is necessary, in order to pre-
pare the food for the subsequent action of the digestive fluids. As
this action is chemical in its nature, it will be exerted more promptly
and efficiently if the food be finely divided than if it be brought in
contact with the digestive fluids in a solid mass. This is always
the case when a solid body is subjected to the chemical action of a
solvent fluid; since, by being broken up into minute particles, it
offers a larger surface to the contact of the fluid, and is more readily
attacked and dissolved or decomposed by it.

In the structure of the teeth, and their physiological action, there
are certain marked differences, corresponding with the habits of the
animal, and the kind of food upon which it subsists. In fish and
serpents, in which the food is swallowed entire, and in which the
process of digestion, accordingly, is comparatively bIow, the teeth
are simply organs of prehension. They have generally the form
of sharp, curved spines, with their points set backward (Fig. 19),
and arranged in a'double or triple row
about the edges of the jaws, and sometimes J^^' ^^'

covering the mucous surfaces of the mouth,
tongue, and palate. They serve merely to
retain the prey, and prevent its escape,
after it has been seized by the animal. In
the carnivorous quadrupeds, as those of
the dog and cat kind, and other similar
fiimilies, there are three different kinds of teeth adapted to different
mechanical purposes. (Fig. 20.) First, the incisors, twelve in num-
ber, situated at the anterior part of the jaw, six in the superior,
and six in the inferior maxilla, of flattened form, and placed with
their thin edges running from side to side. The incisors, as their
name indicates, are adapted for dividing the food by a cutting
motion, like that of a pair of shears. Behind them come the canine
teeth, or tusks, one on each side of the upper and under jaw.
These are long, curved, conical, and pointed; and are used as
weapons of offence, and for laying hold of and retaining the prey.
Lastly, the molars, eight or more in number on each side, are
larger and broader than the incisors, and provided with serrated

Skull or RATTLBiXAKi.

(After AchlUe-Rlcbftrd }

DIGKSTION.

Fig. 20.

edges, each presenting several sharp points, arranged generally in
a direction parallel with the line of the jaw. In these animals,

mastication is very imperfect, since
the food is not ground up, but only
pierceii and mangled by the action
of the teeth before being swallowed
into the stomach. In the berbi-
vora, on the other hand, the inci-
sors are present only in the lower
jaw in the ruminating aiiiinaU,
though iu the horse they are found
in both the upper and lower max*
ilia. (Fig. 21.) They are used merely
for cutting off the bundles of grass
or herbage, on which the animal kaih. The canines are either
absent or slightly developed, and the real process of mastication is

Sxtl.1. or rdLAK RtAK. AOteriltT

Fig. 21.

SSVLI. OF THS tlOttt.

Fig. 22.

performed altogether by the molars. Thaw are large and thick
(Fig. 22), and present a broad, flat surface, diversified by variously
folded and projecting ridges of enamel, with shal-
low grooves, intervening between them. By the
lateral robbing motion of the roughened surfaces
^S/BHSpJl against each other, the food is eilectually eommi-
I9q^2jI nuteti and reduced to a pulpy nia^.
«^H^S^Rj In the human subject, the leeth eombine the
^1^^^^^^ characters of those of the carnivora and the herbi-
Mrtt-A* TcoTB or vora. (Fiff. 23.) The incisors (a), four in number
taii»rrH« iQ each jaw, have, as in other mstaoces, & cutting

4
4

SALirA.

107

jy-

' .d

KdsjI]| Tibtr — Vppo ikV>.—a. Iacl«4>r«. l^ Ch-
ilian, f, AbUrtol mnlkn. J, Poal«r1a( uiulun.

edge running from side to side. The canines (i), which are situnlcfl
immediately behind the former, are much less prominent and
pointed than in the carni'

Tora, and differ less in I^s- S3.

form from the inciBora on ff.

the one hand, and the ^x^X.
molars ou the other. The
molars, again (e^^, nre
thick and strong, and have
compnrfttively fl.U sur*
faces, like those of the her-
bivora; butinstead of pre-
senting curvilinear ridges,
are covered with more or
less conical eminences,
tike those of the carnivora.
In the human subject,
therefore, the teeth are

evidently adapted fur a mixed diet, consisting of both animal and
vegetable food. Mastication is here as perfect aa it is in ihu horbi-
Tora, though less prolonged and laborious; for the vegetable sub-
stances used by man, as already remarked, are previously Bt*paratcd
to a great extent from their impurities, and softened by cooking;
so that they do not require, for their mastication, so extensive and
powerful a triturating apparatus. Finally, animal substances arc
more completely masticated in the human subject than they are in
the carnivora, and their digestion is accordingly completed with
greater rapidity.

"We can easily estimate, from the facts above stated, the great
importance, to the digcaiive process, of a tborough prelimiuary
mastication. If the food be hastily swallowed in nndivided mosses,
.jt must remain a long time undissolved in the stomach, where it
rill beoome a source of irritation atid disturbance; but if reduced
beforehand, by mastication, to a state of minute subdivision, it ia
readily attacked by the digestive fluids, and becomes speedily and
completely liqueiied.

Saliva. — At the aame time that the food is masticated, it is mixed
in the cavity of the mouth with the first of the digestive fluids, viz.,
the saliva. ITuman saliva, as it is obtained directly from the buc-
cal cavity, is a colorless, slightly vi!<uid and alkaline fluid, with a

108

mCBSTIOIf.

speciBo gravity of lOOo. When first discharged, it is frothy and
opaline, holding in suspension minute, whiliiih fluceuli. On being
allowed to stand for some hours in a cylindrical gloss vessel, an
opaqne, whitish deposit collects Rt the bottom, while the supernnUnt
fluid becomes clear. The deposit, when examined by the micro-
scope (l''ig. 24), is seen to
^" consist oi' abundant epithe-

lium scales from the internal
surface of the mouth, de-

,^ ,^_ tached by mechanical iirita-

:;€5 ■ :') 'rf^ \ lion, minute, roundish, gra-
nular, nucleated cells, appa-
rently epithelium fix>m the
mucous follicles, a certain
amount of granular matter,
and a few oil-globules. The
supernatant fluid has a fuinl
bluish tinge, and becomes
slightly opalescent by boil-

DecflAt Ai.i,oi,A»ftoi.iii ip.Tw«LiF». -iih iRg, flud by thc addition of
otMnur «Mi.rMdoii-,ioboi»;i.i».ii»4MMdi- niirio acid. Alcohol in ox-

mtai froiD hamka nlivA. ...

cess, causes the precipitation
of abundant whitish flocculi. According to Bidder and Schmidt,'
the composition of saliva is as follows: —

CovroniTinx of Sauta.

W«t*r 895.16

Organto iaatt«r 1>34

Sul)>liD-{*yaniil« of pota&slum 0.116

rhosplmloa of soda, litno, and mAgnosin .9S

CItloritlT'ti of sodium itnd poCtuislnm .64

MlxtaraorvpHhaiiain 1.A3

IOIMJ.00

The organic substance present in the saliva has been occasionally
known by the name of jttyaline. It is coagulable by alcohol, but
not by u builiug teuiperulure. A very little albumen is also pre-
sent, mingled with the ptyaline, and produces the opalesocnoo
which appears in the saliva when raised to a boiling tomperatore.
The sulpho-cyanogen may be detected by a solution of chloride of
iron, which produces the characteristic red color of sulpbo-oyauide

' V«r(lAuaiiigiHeft« und StoflVocluel. Lalpxig, I8S3.

SALIVA. 109

of iron. The alkaline reaction of the saliva varies in intensity
during the day, l)ut is nearly always sufficiently distinct.

The saliva is not a simple secretion, but a mixture of four dis-
tinct fluids;, which differ from each other in the source from which
they are derived, and in their physical and chemical properties.
These secretions are, in the human subject, first, that of the parotid
gland; second, that of the submaxillary; third, that of the sub-
lingual; and fourth, that of the mucous follicles of the mouth.
These difterent fluids have been comparatively studied, in the
lower animals, by Bernard, Frerichs, and Bidder and Schmidt.
The paroUd saliva is obtained in a state of purity from the dog by
expoeing the duct of Steno where it crosses the masseter muscle,
and introducing into it, through an artificial opening, a fine silver
canula. The parotid saliva then runs directly from its external
orifice, without being mixed with that of the other salivary glands.
It is clear, limpid, and watery, without the slightest viscidity, and
baa a faintly alkaline reaction. The submaxillary saliva is ob-
tained in a similar manner, by inserting a canula into Wharton's
duct. It differs from the parotid secretion, so far as its physical
properties are concerned, chiefly in possessing a well-marked vis-
cidity. It is alkaline in reaction. The sublingual saliva is also
alkaline, colorless, and transparent, and possesses a greater degree
of viscidity than that from the submaxillary. The mucous secre-
tion of the follicles of the mouth, which forms properly a part of
the saliva, is obtained by placing a ligature simultaneously on
Wharton's and Steno's duets, and on that of the sublingual gland,
so as to shut out from the mouth all the glandular salivary secre-
tions, and then collecting the fluid secreted by the buccal mucous
membrane. This fluid is very scanty, and much more viscid than
either of the other secretions; so much so, that it cannot be poured
out in drops when received in a glass vessel, but adheres strongly
to the surface of the glass

According to Bernard,' the principal distinction between these
difierent salivary fluids resides in the character of the organic
matter peculiar to each one. The organic ingredient of the parotid
saliva is small in quantity, perfectly fluid, and analogous in some
respects to albumen, since it coagulates by a boiling temperature.
That of the submaxillary is moderately viscid, and has a tendency
to solidify or gelatinize on cooling; while that of the sublingual

• L«fODa de Physiolcgle Eip^rimentale, Paris, 1806, p. 93.

110

folsi

and muooQs sccrfitions is exceaaivcly viscid, bot does not gelatinize
at A low temperature.

Tbe saliva proper consists, therefore, of a nearly bomogenoous
mixture of all these dlfferonl secretions; of which that from the
parotid is the moat abundant, that of ibc sublingual and of the
mucous fullicles of tbe mouth tbe least so. Bidder and Schmidt
obtained, from one of tbe parotid glanda of the dog, one hundred
and thirty-six grains of fluid in an hour; from the submaxillary,
eighty-seven grains; and from the raucous follicles of the mouth,
after ligature of both Wharton's and Steao*s ducta, thirty-ouo
grains. Tbe saliva, as a whole, is not secreted with uniform
rapidity at all times. While fasting, and while the tongoe and
jaws are at rest, it is supplied in but small quantity, just sufficient
to keep the mucous membrane of the mouth moist and pliable.
Any movement of the jaws, however, increases the rapidity of its
flow. ]t is still more powerfully stimulated by the introduction of
food, particularly thai which baa a decided lasto.or which requires
an active movement of the jaws for its mastication, Tbe saliva is
then poured out in abundance, and continues to be rapidly stxreted
until tbe food is masticated and swallowed.

A very curious fact has been observed by M. Colin, Professor of
Anatomy and Physiology at the Veterinary School of Alfort," viz^
that in the borae and ass, as well as in tbe cow and other ruminat-
ing animals, tbe parotid glands of the two opposite sides, during
mastication, are never In active secretion at the same time; but
that they alternate with e»di other, one remaining quicseont while
the other in active, and vice vertd. In these animals, mastication is
said to be uuilateral, that is, when the animal commences feeding
or ruminnting, the food is triturated, for fifteen minutes or more, by
tbo molars of one side only. Ii is then changed to the opposite
side; and for the next fifteen minutes maslicalion is performed by
the mulars of that aide only. It is then changed back again, and
BO ou alternately, so that tbe direction of tbe lateral movements of
the jaw may be reversed many times during the course of a meal.
By cstnblisliing a salivary fistula simultaneously on each side, it is
found thnt the flow of saliva corresponds with the direction of the
masticatory movement. When tbe animal masticates on the right
side, it is the right parotid which secretes actively, while but little
saliva is supplied by tbe left; when mastication ia on tbe letl aide,

< TraitC- do Pli^Biologlfl C<miparfe. Paris, 18M, p. 46S.

SALIVA. Ill

the left parotid pours out an abandance of flaid, while the right is
nearly inactive.' It is probable, however, that this alternation of
fanctioD does not exist, to the same extent at least, in man and the
carnivora, in whom mastication is performed very nearly on both
sides at once.

Owing to the variations in the rapidity of its secretion, and also
to the fact that it is not so readily excited by artificial means as
by the presence of food, it becomes somewhat difficult to estimate
the total qtioniiii/ of saliva secreted daily. The first attempt to do so
was made by Mitscherlich,* who collected from two to three ounces
in twenty-four hours from an accidental salivary fistula of Steno'a
duct in the human subject; from which it was supposed that the
total amount secreted by all the glands was from ten to twelve
ounces daily. As this man was a hospital patient, however, and
suffering from constitutional debility, the above calculation cannot
be regarded as an accurate one, and accordingly Bidder and Schmidt'
make a higher estimate. One of these observers, in experimenting
upon himself, collected from the mouth in one hour, without using
any artificial stimulus to the secretion, 1500 grains of saliva; and
calculates, therefore, the amount secreted daily, making an allow-
ance of seven hours for sleep, as not far from 25,000 grains, or
about three and a half pounds avoirdupois.

On repeating this experiment, however, we have not been able to
collect from the mouth, without artificial stimulus, more than 566
grains of saliva per hour. This quantity, however, may be greatly
increased by the introduction into the mouth of any smooth un-
irritating substance, as glass beads or the like; and during the
mastication of food, the saliva is poured out in very much greater
abundance. The very sight and odor of nutritious food, when the
appetite is excited, will stimulate to a remarkable degree the fiow
of saliva; and, as it is often expressed, "bring the water into the
mouth." Any estimate, therefore, of the total quantity of saliva,
based on the amount secreted in the intervals of mastication, would
be a very imperfect one. We may make a tolerably accurate
calculation, however, by ascertaining how much is really secreted
during a meal, over and above that which is produced at other times.
We have found, for example, by experiments performed for this
purpose, that wheaten bread gains during complete mastication 55
per cent, of its weight of saliva; and that fresh cooked meat gains,

' Simon'i Cbemistr; of Mu. Pbila. ed., 1846, p. 295. > Op. cit., p. 14.

112

DIOESTIOW,

under the same circumstances, 4S percent, of its weight. We Tiave
already seen that the daily allowaikce of thei^j two substances, for a
man in full healtli, is 19 ounces of bread, and 16 ounces of meat.
The quantity of snliva, then, requirwi for the mastication of these
two substances, is, for tbc bread 4,572 grains, and for the meat 3,860
grains. If we now calculate ibe quantity secreted between meals
as coatlnuing for 22 hours at 556 grains per hour, we have:—

Saliva i«qnlr«d far maatlaation of brend = 4572 ffrains.
" " " " '■ m«Bt = 3360

•• HffcniM in InterraN of iii«aU = 12S32 "

Totnl qnintity in twonty-four lionrs = 2(1164 grains;

or rather less than 3 jiounda avoirdupois.

Tlio mast important question, conuected with this subject, relates
to the /unction of the saliva m the digestive process. A very remark-
able property of this fluid ia that which waa discovered by Leuchs
in Germany, viz., that it possesses the power of coDverting boiled
starcli into sugar, if mixed with it in (!<iiial proportions, and kept
for a short time at the temperature of 100° ¥. This phenomenon
is one of catalysis, in which the starch is transformed into sugar by
simple contact wiOi the organic substance contained in the saliva.
This organic substance, according to the experiments of Mialhe,'
may even be precipitated by alcohol, and kept in a dry state for an
indefinite length of time without losing the power of converting
starch into sugar, when again brought in contact with it in a state
of solution.

This uction of ordinary liuman saliva on boiled starch takes place
somotimes with great rapidity. Traces of glucose may occaeiODally
be detected in the mixture in one minute afYer the two substances
have been brought in contact; and wo have even found that starch
paste, introduced into the cavity of the mouth, if already at the
temperature of 100° F., will yield traces of sugar at the end of half
a minute. The rapidity, however, with which this action is mani-
fested, vnrics very much, as was formerly noticed by Lehmann, at
different times; owing, in all probability, to the varying constitution
of the saliva itself. It is oUeu impossible, for example, to Hud any
evidences of sugar, in the mi.xture of starch and saliva, under five,
ten, or fifteen minutes; and it is frequently a longer time than this
before the whole of the starch is completely transformed. Kven
when the conversion of the starch commences very promptly, it is

< Clilmlu sppUqnf-e h la rii^rsiologle et i, la Tli£rai>BUt[(|a«, Paris, ISStl, p. 43.

SALIVA.

118

often a long time before it is finished. If a thin starch paste, for
example, which contains no traces of sugar, be tnken into the motiib
and tboroDglily mixed with the buccal secretions, it will o(\cn, as
already mentioned, begin to show the reaction of sugar lu the course
of half a minute ; but some of the starchy matter still remains, and
will continue to manifest its characteristic reliction with iodine, for
fifteen or twenty minutes, or even half an hour.

The above action of the saliva on starch, according to the expe-
riments of Mugendie, Beraard, Bidder and Schmidt, &c., does not
reside in either the parotid, submnxillary or mucous secretions
taken separately; but only in the mixed saliva, as it comes from
the cavity of the mouth. The submnxillary and m ucous secretions,
however, taken together, produce the chiinge; though neitherof them
has any eflfectnloiie, nor even when mixed artiQcially with the saliva
of the parotid.

It was supposed, when this property of converting starch into
sugar was 6rst discovered in ihe saliva, that it constitute the true
physiological action of this secretion, and that the function of the
fuliva was, in reality, the digestion and liquefaction of starchy
substances. It was very soon noticed, however, by the French
observers, that this property of the sniiva was rather an accidental
than an essential one; and that, although starchy substances are*
really converted into sugar, if mixed with saliva in a test-tube,
yet they are not ailecttid by it to the same degree in the natural
procosa of digestion. We have already mentioned the extremely
variable activity of the saliva, in this respect, at different times;
aud it must be recollected, also, that in digestion the food is not
retained in tlic cavity of the mouth, but passes at once, af\cr mas-
^ticalion, into the stomach. Several German observers, as Frerichs,
facubowitsch, Bidder and Schmidt, maintained at 6rst that the
saccharine conversion of starch, after being commencecl in the
mouth, might be, and actually was, completed in the slomach. We
have convinced ourselves, however, by frequent experiments, that
tbia is not the case. If n dog, with a gastric fistula, be fed with a
mixtare of meat and boiled starch, and portions of the fluid coo-
tents of ibe stomach wlthdruwu ufierward through the H^tula,
atarob is easily recognizable by its reaction with iodine for ten,
Ifteen, and twenty minutes afterward. In forty-five minutes, it is
liminished in quantity, and in one hour has usually altogether dis-
^appeared ; but no sugar is to be detected at any time. Sometimes
8

114

PIQBSTIOir.

tbe sUruli disappears more rapidly than tliis; but at no time, accord-
ing to our observations, is there any indication of the presence of
sugar in tbe gastric Quids. Bidder and Schmidt hitve also concluded.,
from subsequent investigattona,' that the first experiments performed
tmder iheir direction by Jaciibowitseb were erroneons; and it is
DOW acknowledged by them, as well as by the French olMervera,
that sugar cannot be detected in the ^tomacli, afler the introduction
of starch, in any form or by any method. In the ordinary process
of digestion, in fact, starchy matters do not remain long enough id
ths mouth to be altered by tbe saliva, but pans at once into tbe sto-
nuh. Here they meet with the gastric fluids, which become min-
gled with thera, and prevent the change which would otherwise be
cflcctcd by iho saliva. We have found .that the gastric juice will
interfere, io this manner, with the action of the saliva in the test-
lube, as well as in the stomach. If two mixtures be made, one of
starch and saliva, the other of starch, saliva, and gastric juice, and
lioth kept for 6fteen minntes at the temperature of 100° F., in the
first mixture the starch will be promptly converted into sugar, while
in the second no such change will take place. The above action,
iherefure, of saliva on starch, though a curious and interesting pro-
{torty, has no significance as to its physiological function, since it
does not take place in the natural digestive process. We shall see
hereafter that there are other means provided for tbe digestion of
Bturchy matters, altogether indi-pendent of the action of the saliva.
The true function of the saliva is altogether a physical one. Its
action i.s simply to moisten the food and facilitate its mastication,
as well as to lubricate the triturated moes, and assist its passage
down the tesophagus. Food which is hard and dry, like crusts,
crackers, &c., cannot he masticated and swallowed with readiness,
unless moistened by someHuid. If the saliva, therefore, be prevented
from entering the cavity of the mouth, its loss does not interfere
directly with the chemical changes of the food in digestion, but only
with its mechuuical preparation. Tliis is the result of direct ex[>eri-
ments performed by various observers. Bidder and Schmidt,* after
tying Steno'a duct, together with the coranion duct of the sub-
maxillary and sublingual glands on both sides in the dog, found
that the immediate eB'ect of such an operation was "a remarkable
diminution of iholluids which exude upon the surfaces of the mouth;
8o that these surfaces retained their natural moisture only so long

* Op oit, p. T9.

■Op. elt., p. 3.

SALIVA. 116

as the month waa closed, and readily became dry on exposure to
contact with the air. Accordingly, deglutition became evidently
difficult and laborious, not only for dry food, like bread, but even
for that of a tolerably moist consistency, like fresh meat The
animals also became very thirsty, and were constantly ready to
drink."

Bernard* also found that the only marked effect of cutting off
the Qov of saliva from the mouth was a difficulty in the mechani-
cal processes of mastication and deglutition. He first administered
to a horse one pound of oats, in order to ascertain the rapidity with
which mastication would naturally be accomplished. The above
quantity of grain was thoroughly masticated and swallowed at the
end of nine minutes. An opening had been previously made in
the cBsophagus at the lower part of the neck, so that none of the
food reached the stomach; but each mouthful, as it passed down the
oesophagus, was received at the oesophageal opening and examined
by the experimenter. The parotid duct on each side of the face
was then divided, and another pound of oats given to the animal.
Mastication and deglutition were both found to be immediately
retarded. The alimentary masses passed down the oesophagus at
longer intervals, and their interior was no longer moist and pasty,
as before, but dry and brittle. Finally, at the end of twenty-five
minutes, the animal had succeeded In masticating and swallowing
only about three-quarters of the quantity which he had previously
disposed of in nine minutes.

It appears also, from the experiments of Magendie, Bernard, and
Lassaigne, on horses and cows, that the quantity of saliva absorbed
by the food during mastication is in direct proportion to its hard-
new and dryness, but has no particular relation to its chemical
qualities. These experiments were performed as follows: The oeso-
phagus was opened at the lower part of the neck, and a ligature
placed upon it, between the wound and the stomach. The animal
was then supplied with a previously weighed quantity of food, and
this, as it passed out by the oesophageal opening, was received into
appropriate vessels and again weighed. The difference in weight,
before and after swallowing, indicated the quantity of saliva absorbed
by the food. The following table gives the results of some of Las-
flaigne'a experiments,' performed upon a burse : —

> Leifons ds Physiologie Exp^rimentale, Paris, 1856, p. 146.
' Comptea Reuiiua, vol. xxi. p. 362.

116

DIOSSTION.

KiRD OF Food bxplotbd. QtrAtmrT op Saiita lAuiBn.

For IDO parts of haj there won ftbaorlwd 400 t>artfl mIIta.

" barley meal " 1S«

" oau " 113 "

" graaDHtalksAnd Ic&res " 49 *'

Tt is evident, from the above fucts, that the quantity of aalira
produced has Dot so much to do with the chemical character of the
food OB with its physical cotiditiou. Wheu Uie food is drj and
hard, and requires much mastication, the saliva is secreted in
abundance; when it is suft and moist, a smaller quantity of the
sccrciion is poured out; and finally, when the food is taken in a
fluid form, as soup or milk, or reduced to powder and moistened
artificially with a very large quantity of water, it is not mixed at
all with the saliva, but passes at once into the cavity of the stomach.
Tbe abundant and wnti^ry fluid of tho parotid gland is moat aseful
in assisting masLlcation; while the glairy and mucous secretion of
the submaxillary gland and the muciparous follicles serve to labii-
cate the exterior of the triturated mass, and facilitate its passage
through the oesophagus.

By tbe combined operation of tho two processes which tbe food
undergoes in tbe cavity of the mouth, its preliminary preparation
is acuotnplishod. It is triturated and disintegrated by the teeth,
and, at the same lime, by the movements of the jaws, tongue, and
cheeks, it is intimately mixed with the salivary fluids, until the
whole is reduced to a soft, pasty mass, of the same consistency
throughout. It is then carried backward by tbe semi-involuntary
movements of the tongue into the pharynx, and conducted by the
mascuUr contractions of the oesophagns into the stomach.

Qastric Ji;icB, and Stomach Digestion.— The mucous mem-
brano of the stomach is distinguished by its great vascularity
and the abundant glandular apparatus with which it is provided.
Its entire thickness is occopicd by certain glandular organs, the
gastric tubules or follicles, which arc so closely sot as to leave
almost no space between them except what is required for the
capillary bloodvessels. The free surface of the gastric mucous
membrane is not smooth, but is raised in minute ridges and pro-
jecting eminences. In the cardiac portion (Fig. 25), these ridges
are reticulated with each other, so as to include between them
polygonal interspaces, each of which is encircled by a capillary
network. In the pyloric portion (Fig. 26), the eminences are more

LStRIC JDtCB, AKD BTOKACH DiniSTIOS'.

or less pointed and cooical in form, and generally flattenal from
side to side. Tbey contain each a capillary bloodveasel, which le-

Fig. 2i.

Fig. as.

\ ■

BSek, Ouillae pofllon. Mafalllail TO dUmnlan.

Pig. M rrw mibc* of QAirBiD Mtrrvni 1<«h*niss, vUwvil tn vvrtltwi *MiJaa ; ttvm
n^i Btoaaek, PflDria portlan. Ua^DiSnl 43D dUnclvm.

turns upon itself in a loop at the extremity of tlie projection, and
commuaic-utes freely witb adjacent vessels. The gastric fulUcled are
very difl'urent in difieretit
p*rts of the stomach. In the *''*■ "'•

pyloric portion (Fig. 27), tlicy
are nearly straight, simple
tabales, ,lo of an inch in
diameter, easily separated
from each other, lined with
glandular epithelium, and ter-
minating in blind extremities
at the under surface of the
maoous membrane. They are
sometimes slightly branched,
or provided with one or two
rounded diverticula, a short
distance above their termiii.v
lion. They open on the free
surface of the mucous mem-
tmne, in the interspaces be-
tween the projecting folds or villi. Among these tubular glandules

PjrtDtIc portion: Tortlnl ■saltan ; ■hnwliiff i;lrlo
lubiil^s ■■•4, M (I, B «lu*fd fulJIcla. Hj^alAcd ;•)
dl*iui>tiir>.

118

BIOESTIO!r.

there is also found, in the gaalric mucous membrnne, another kind!
of glandular organ, consisting of closed follicles, similar to the soli-
tary glands of the small intestine. These follicles, wliich are not very
numerous, arc seated in the lower part of iho mucoua membrane,
and enveloped by the Ciocal extremities of the tubules. (Fig. 27, o.)

Fig. 2S.

Ftg.2».

"-*:-f

'*^^-'

Pl( n, a««TiiicTciiiir-KBrRoaPtii'«!lT«HjrR, Pjrlorie puiltno, ibowlaj Ibalr Cxal
Bxtrvdilllvt. AI a. Ilm lurn nslrrniiij of a rubul*, ttiowlag 1U C«Tll7

Pig. S. UitiTKio TU'nui.Ki rK'>)i V lo'* Sraai'iMi CanllAc porlloB. At a, ft Ur^t takiU*
dlrldlng Into two BtD^I obm. b Partlon nf «, [nlkola, mm •udwlan. c. It* Mnttal eaTHjr.

In the cardiac portion of the stomach, the tubules are very wide
in the stiperficiiil part of the mucous membrane, and liuod with
large, distinctly marked cylinder epithelium cells. (Fig. 29.) In the
deeper parts of the membrane they become branched and conside-
rably reduced in size, from the point where the branching takes
place to their termination bclow^ they are lined wilii small glandular
epithelium cells, and closely bound together by intervening areolar ■
tissue, so as to present aomowhac the appearance of compound
glandules.

The bloodvessels which come up from the submucous layer of
areolar tiasuo form a close plexus around alt these glandules, and
provide the mucous membrane with an abundant supply of blood,
lor the purposes both of secretion and absorption.

That part of digestion which takes place in the stomach has
always been regarded as nearly, if not quite, tlie most important
part of the whole process. The first observers who made any
approximation to a correct idea of gastric digestion were Heaumur
and Spallaozani, who showed by various methods that the reduction

eXSTRIC JUICB, AND BTOMAOHDTGHSTIOK.

119

and liqueraclion of Lh« food m tbe stomach, could uot be owing to
mere contact with the gastric mucous membrane, or to compression
by the muscular walla of the organ ; but that it must be attributed
to a digestive fluid secreted hy the mucous membrane, which pene-
trates the food and reduced it to u Quid form. They regarded this
process as a simple chemical solution, and considered the gastric
juice as a universal solvent for all alimentary substances. They
succeeded even in obtaining some of this gastric juice, mingled
probably with many impurities, by causing the animals upon which
they experimented to swallow sponges attached to the ends of
cords, by which they were afterward withdrawn, the fluids whieh
they had absorbed being then expressed and examined.

The first decisive experiments on this point, however, were those
performed by Dr. Beaumont, of the U. S. Army, on the person of
Alexia St. Muriin, a Canadinu boatman, who had a permanent gas-
tric fistula, the result of an accidental gunshot wound. The musket,
which was loaded with buckshot at the time of the accident, waa
discharged, at the distance of a few feet from St. Martin's body, in
such a. manner as to tear away the integument at the lower part of
the lel\ chest, open the pleural cavity, and penetrate, through the
lateral portion of the diaphragm, into the grent pouch of the stomach.
After the integument and the pleural and peritoneal surfaces bad
nnit«d and cicatrized, there remained a permanent opening, of about
four-Gflhs of an inch in diameter, leading into the led extremity of
the stomach, which was usually closed by a circular valve of pro-
trading mucous membrane. This valve could be readily depressed
at any time, so as to open the fistula and allow the contents of the
stomach to be extracted for examination.

Dr. Beaumont experimented upon this person at various intervals
from the year 1826 to 1832.' He established during the course of
bis examinations the following important facts: First, that the ac-
tive agent in digestion is an acid fluid, secreted by the walls of the
stomach; secondly, that this fluid \a poureii out by the glandular
walls of the organ only daring digestion, and under the stimulus of
the food; and 6nal]y, that it will exert its solvent action upon the
food outside the body as well as in the stomach, if kept in glass
phials upon a sand bath, at the temperature of 100^ F. He made
also a variety of other interesting investigations as to the efTect
of various kinds of stimulus on the secretion of the stomach, thd

' EiprhiunDUi sad UbMrvatlOM upoo the Outric Juic«. Boston, 1^34.

DtOESTIOir.

rapi<1ity with which the process of digestion takes place, the com-
parative digestibility of various kinds of food, kc. &C.

Since Dr. Beaumont's time it bos been ascertained that aimilar
gu5tric fistula! may be produced at will on some of the lower animals
by a simple operation; and the gastric juice has in this way been
obtained, usually from the dog, by Blondlot, Schwann, Bernard,
Lehmann and others. The siniplest and most expeditious modo
of doing ihe opemlion is the best. An incision should be mado
through the abdominal parieies in the median line, over the great
curvature of the stomach. The anterior wall of the organ is then
to be seized with a pair of hooked forceps, drawn out at the external
wound, and opened with the point of a bistoury. A abort silver
caniila, one-half to three-quarters of an inch in diameter, armed at
each extremity with a narrow projecting rim or flange, i.i then in-
serted into the wound in the stomach, the edges of which are fast-
ened round the tube with a ligature in onler to prevent the escape
of the gastric fluids into the peritoneal cavity. The stomach is then
retumet^l to its place in the abdomen, nnd the canula allowed to re-
main with its external flange resting upon the edges of the wound
in the abdominal integuments, which are to be drawn together by
sutures. The animal may be kept perfectly quiet, during the ope-
ration, by the administration of ether or chloroform. In a few
days the ligatures come away, the wounded peritoneal surfaces are
united with each other, and the canula is retained in a permanent
g»9tric flKtula; being prevented by its flaring extremities both from
falling out of the abdomen and from being accidentally pushe<1 into
the stomach. It is closed externally by a cork, which may be with-
drawn at pleasure, and the contents of the stomach withdrawn for
examination.

Experiments conducted in thta manner confirm, in the mnin, the
results obtained by Dr. Beaumont. Observations of this kind are
in some respects, indeed, more satisfactory when made upon the
lower aiiimaliH, than upon the human subject; since animals aro
entirely under the control of the experimenter, and all sources of
deception or mistake aro avoided, while the investigation is, at the
same time, greatly facilitated by the simple character of their foo<l.

The gastric juice, like the saliva, is secreted in considenible
quantity only under the stimulus of recently ingested food. Dr.
Beaumont states that it is entirely absent during the intervals of
digestion; and that the stomach at that time contains no acid fluid,
but only a little Qcntral or alkaline mucus. He was able to obtain

OJISTBIC JDICK, ASD HTOMACH DIOSSTIOX.

12X

a snfficient quantity of gastric juice for examination, by genlly irri-
tatiug the mucous membrane wiih a gum-ela«lic catbeter, ot ihe end
of a gUss rod, and by collecting tbe secretioa as it raa in drops
from the Sstula. On the inlroduction of food^ be found that the
tnuooua membrane became turbid and reddened, a clear acid fluid
ooUected everywhere in drops uriderneath the layer of mucus lin-
iug the walls of tbe stomach, and was soon poured out abundantly
into its cavity. We have found, buwuver, tliat tlm rule laid down
by Dr. Beaumont in thin respect, tiiough correct in the main, is not
invariable. The truth is, tbe irritability of tbe gastric mucous
membrane, and the readiness with which the (low of gastric juice
may be excited, varies conbiderably in diQ'erent auimala ; even ia
those belonging to the same species. In experimenting with gastric

iAatuIce on diflureoldogs, for example, we Iiave found in one instance,
like Dr. Beaumont, that the gastric juice was always entirely absent
in the intervals of digestion; the mucous membrane then present-
ing invariably either a neutral or slightly alkaline reaction. In
this animal, which was a perfectly healthy one, the secretion could
not be excited by any artificial means, such as glass rods, metallic
catheterA, and tbe like; but only by the natural stimulus of ingested
food. We have even Been tough and indigestible pieces of tendon,
introduced through the fistula, expelled again in a few minutes, ono
tflcr the other, without exciting the Bow of a single drop of acid
fiaid; while pieces of fresh meat, introduced in tbe same way, pro*
duced at once an abundant supply. In other instances, on the con-
trary, the introduction of metutlic catheters, iic, into the empty
Btomacb has produced a scanty flow of gastric juice; and in experi-
menting upon dogs that have been kept without food during various
periods of time and then killed by section of the medulla oblongata,
TO have usually, though not always, found the ga.stric mucous mem-
brane to present a distinctly acid reaction, even after an abstinence
of six, aoveo, or eight days. There is at no time, however, under
these circumslances, auy considerable amount of Quid present ia
the stomach; but only ju.st suiTicient to moisten the gastric mucous
membrane, and give it an acid reaction.

1*fae gastric juice, which is obtained by irritating the stomach
with a metallic catheter, is clear, perfectly colorless, and acid in
iRaelion. A suflicient quantity of it cannot be obtained by this

ihod for any extended experiments; and for that purpose, the
animal should be fed, after a fast of twenty-four hours, with fresh
lean meat, a little hardened by short boiling, in order to coagulate

122

DIGESTION.

Iha fluid? of the muscular tissue, and prevent their mixing with the
gastric secretion. No efleet is usually fl|)parent within tlio first flvo
mtnut<^ t.tw.r the introduction of the food. At the end of that time
the gastric juice begins to flow; at first slowly, and in drops. It is
then perfeytly colorless, but very soon acquires a alight amber
tinge. It then begins to flow more freely, usually in drops, but
oAen running for a few seconds in a continuous alrcam. In this
way from ,5ij to Siias may be collected in the course of fifteen
minutes. Afterward it becomes somewhat turbid with the debris
of the food, which has begun to be diirintegrated; but from tbia it
may be readily separated by filtration. After three hours, it oon-
linuoa to run freely, but has become very much thickened, and
even grumous in consistency, from the abundant admixture of
alimentary debris. In six hours after the commencement of diges-
tion it runs less freely, and in eight hours has become very scanty,
though it continues to preserve the same physical appearances as
before. It ceases to flow altogether in from nine to twelve hours,
according to the quantity of food taken.

For purposes of examination, the fluid drawn during the first
fifteen minutes after feeding should be collected, and separated by
filtration from accidental impurities. Obtained in this way, the
gtotrio juice is a clear, watery fluid, without any appreciable vis-
cidity, very distinctly acid to test paper, of a faint amber color,
and with a specific gravity of lOlD. It becomes opalescent on
boiling, owing to the coagulatron of its organic ingredients. The
following is the composition of the gastric juice of the dog, based
on a comparison of various analyses by Lehm.aan, aud Bidder and
Schmidt:—

CoMPuHTioa or Oahtiiic Jdicx.

Wnt«r 078.00

Organic mutter 16.00

I<*clfG JUiiA 4,78

Clilorldsof aodioin I.JO

" " pi>iBH«iDni 1,08

" " mlduin (KSO

" " annmoninni 0.65

I'houpbalv of limn 1.48

" " mngcrsia 0M

*' " ina 0.06

lOW.OO

In place of lactic acid, Bidder and Schmidt found, in most of their
ar.aly.ws, hydrochloric acid. Lehmann admits that a small quantity
of hydrochloric acid i» sometimes present, hut regards lactic acid

OASTBIO JUICB, AXn STOUACH DIOSSTIOIT.

128

08 much the most abundant aud important of the two. Kobin and
, Venleil also regard the acid reaction of the gn»trio juice as due to
lactic acid; and, finally, Bernard has shown,' by a serlea of well
contrived experiments, that the free acid of the dog's gastric juice
ia undoabtedly the lactic ; and that the hydrochloric acid obtained
by distillation, is really produced by a docom position of the chlo-
rides, which enter into the CGmpoattion of the fresh juice.

The free acid is an extremely important ingralient of the gastric

BecrettoD, and is, in fact, essential to its physiological properties;

[for the gastric juice will not exert its solvent action upon the fuod,

after it has been neutralized by the additioa of on alkali or &u

.alkaline carbonate.

The most important ingredient of the gastric juice, beside the
acid, is its organic matter or "ferment," which is sometimes
[IcnuwQ under the name of ptpsine. This name, "pepsine," was
^originally given by Schwann to a substance which he obtiiinod
[from the mucous membrane of the pig^s stomach, by macerating it
in distilled water until a putrid odor began to be developed. The
substance in question was precipitated from the watery infusion by
the addition of alcohol, and dried; and if dissolveti afterward in
adulated water, it was found to exert a solvent a<;tioa qu boiled
white of egg. This substance, however, did not represent precisely
the natural ingredient of the gastric secretion, and was probably a
mixture of various matters, some of them the products of com-
tnencing decomposition of the mucous membrane itself. The name
pepsine, if it be used at all, should be applied to the organic matter
which naturally occurs in solution in the gastric juice. It is alto-
gether uncsseniial, in this respect, from what source it may be
originally derived. It has been regarded by Bernard nod others,
on somewhat insufficient groundu, as a product of the alteration of
the mucus of the stomach. But whatever be its source, since it is
always present in the secretion of the stomach, and takes an active
part in the performance of its function, it can be regarded in no
other light than as a real anatomical ingredient of the gastric juice,
and as es.'-ential to its constitution.

Pepsins is precipitated from its solution in the gastric juice by
absolute alcohol, and by various metallic salts, but is not aflectcd
by fernxyanidc of potassium. Tt is precipitated also, and coAgu-
laled, by a boiling temperature; and the gastric juice, accordingly.

Lvi.'ooa <!• Phjniitilouia Kxp£fimcnl«l«, IHirit, ISStf, p. 390.

124

DlQBSTtON'.

after being boiled, becomes turbid, and loses altogether its power
of dissolving alitneoiary substances. Gastric juice is also affected
in a remarkable manner by being mingled with bile. We have
found that four to six drops of dog 'a bile precipitate completely
with 5j of gastric jaice from the same auiinal ; so that the whole uf
the biliary coloring matter is thrown down as a deposit, and the
filtered fluid is found to have lost entirely its digestive power,
though it retuiiis an acid reaction.

A very singular property of the gastric juice is its inaptitude /or
putrefaction. It may be kept for an indeilnite length of lime in a
common glass-stoppered bottle without developing any putrescent
odor. A light deposit generally collects at the bottom, and a cod*

fervoid vegetable growth or
Kg. 30. " mould" otlen shows itaelf

in the fluid afler it baa been
kept for one or two weeks.
This growth has the form of
white, globular luasKcs, each
of which is composed of deli-
cate radiating branched fila*
ment9(Fig.30); each lilament
consisting of a row of elon-
gated cells, like other vege-
table growths of a similar
nature. These growths, how-
ever, are not accompanied by
any puirefactive changes, and
the gastric juice retains its
acid reaction and its digestive
properties for many months.
By experimenting artificially with gastrio juioe on various ali-
mentary substances, such M meat, boiled white of egg, &c., it la
found, as Dr. Beaumont formerly observed, to exert a solvent action
on these substances outside the body, as well as in the cavity of the
stomach. This action is most energetic at the temperature of 100"*
F. It gradually iliminishesin iiiiensity below that point, and cea&ea
altogetbar near 32". If the temperature bo elevated above 100"
the action also becomes enTeebled, and is entirely suspended about
160°, or the temperature of coagulating aH>umun. Contrary to
what was supposed, however, by Dr. Beaomont and his predcc«a*
ftora, the gastric juice is not a universal solvent for all alimentary

C»»rB>TOir Vau>T««i.K (ntwios In lh« Oa*-
trie JhIm uf ih# Doc. the Abntt li«*o »u itiwiigt
dlaoiernruri-TOCAur •» liicli.

I
I

OA3TBIC JUICE, AND STOMACH DIGESTION. 126

snbstances, bat, on the contrary, aSecta only a single class of the
proximate principles, viz., the albaminoid or organic snbstances.
Neither starch nor oil, when digested in it at the temperatnre of
the body, suffers the slightest chemical alteration. Fatty matters
are simply melted by the heat, and starchy substances are only
hydrated and gelatinized to a certain extent by the combined influ-
ence of the warmth and moisture. Solid and semi-solid albuminoid
matters, however, are at once attacked and liquefied by the diges-
tive fluid. Pieces of coagulated white of egg suspended in it, in a
test-tube, are gradually softened on their exterior, and their edges
become pale and rounded. They grow thin and transparent;
and their substance finally melts away, leaving a light scanty de-
posit, which collects at the bottom of the test-tube. While the
diuntegrating process is going on, it may almost always be noticed
that minute, opaque spots show themselves in the substance of the
liquefying albumen, indicating that certain parts of it are lera easily
attacked than the rest ; and the deposit which remains at the bot-
tom is probably also composed of some ingredient, not soluble in
the gastric juice. If pieces of fresh meat be treated in the same
manner, the areolar tissue entering into its composition is first
dissolved, so that the muscular bundles become more distinct, and
separate from each other. They gradually fall apart, and a little
brownish deposit is at last all that remains at the bottom of the
tube. If the hard, adipose tissue of beef or mutton be subjected
to the same process, the walls of the fat vesicles and the inter-
vening areolar tissue, together with the capillary bloodvessels, &C.,
are dissolved ; while the oily matters are set free from their en-
velops, and collect in a white, opaque layer on the surface. In
cheese, the casein is dissolved, and the oil which it contains set
free. In bread, the gluten is digested, and the starch lefl un-
changed. In milk, the casein Is first coagulated by contact with
the acid gastric fluids, and aftierward slowly liquefied, like other
albuminoid substances.

The time required for the complete liquefaction of these sub-
stances varies with the quantity of matter present, and with its state
of cohesion. The process is hastened by occasionally shaking up
the mixture, so as to separate the parts already disintegrated, and
bring the gastric fluid into contact with fresh portions of the diges-
tible substance.

The liquefying process which the food undergoes in the gastrio
juice is not a simple solution. It is a catalytic transformation.

126

DT0E9TI0TI.

produced in the albuminoid subaiLancca by contact with the organic
matter of the digealive fluid. This organic matter acts in a Bimilar
manner to that of the catalytic bodies, or "ferments,"' generally.
Its peculiarity is that, for ila active operation, it requires to be dia-
solved in an acidulated fluid. In common with other ferments, it
requires also a moderate degree of warmth; ita action being checked,
both by a very low, and a very high temperature, hj its opera-
tion the albuminoid matters of the food, whatever may have been
their original character, are all, without distinction, converted into
a new substance, viz., albuminose. This substance has the geiioral
characters belonging to iho class of organic matters. ]t is oncryB*
talliziible, and contains nitrogen as an ultimate element. It is pre-
cipitated, like albumen, by an excess of alcohol, and by the metallic
salts; but unlike albumen, is not aB'ected by nitric acid or a boil-
ing temperature. It is freely soluble in water, and after it is once
produced by the digestive proceas, remains in a fluid condition,
and is ready to be absorbed by the veaaels. In this way, cawio,
fibrin, masculine, gluten, iSw., are all reduced to the condition of
albaminoae. By experimenting as above, with a mixture of food
and gastric juica in teat tubes, we have found that the casein of
cheese is entirely converted into albuminose, and dissolved under
that form. A very considerable portion of raw white of egg, how-
ever, dissolves in the gastric juice directly as albumen, and retains
its property of coagulating by heat. Soft-boiled white of egg and
raw meat are principally converted into albuminose; but at the
same time, a small portion of albumen is also taken up unchanged.

The above process is a true liquefaction of the albumiaoid eub-
stances, and not a simple disintegration. If fresh meat be cut into
small pieces, and artiticially digested in gastric juice in test-iubcs,
at 100" h\, and the process assisted by occasional gentle agitation,
the fluid continues to take up more and more of the digestible
material for from eight to ten hours. At the cud of that time if it
be separated and filtered, the iiltered fluid has a distinct, brownish
color, and is saturated with dissolved animal matter. Its specific
gravity is found to have increased from 1010 to 1020; and on the
addition of alcohol it becomes turbid, with a very abundant whitish
precipitate (albuminose). There is also a peculiar odor developed
during this process, which reaeinblea that produced in the malting
of barley.

Albuminose, in solution in gastric juice, has several peculiar
properties. One of the most remarkable of these is that it inter*

OASTRIC JL'ICB, AND STOMACH DIGSSTION.

121

rith the operation of Trommer's test for grape sugar (uee
iS). We first observed and described this peculiarity in
ld&4,* but could not determine, at that time, upon what particular
ingredient of the gastric Juice it dupeniled. A short time Bubw-
quenily it was also noticed by M. Longet, in Paris, who published
his observations in the Gazette Hdidomadaire for February 9th,
185.V He altributcd the reaction not to the gastric juice itself^
but to the albucDinase held in solutioii by it. We have since found
this explanation to be correct. Gastric juice obtained from the
empty stomach uf the fasting aniinnl, by irritation with a nietallio
catheter, which is clear and perfectly colorless, does not interfere
in any way with Trommer's test; but if it be macerated for some
huura in a test-tube with (inely chopped meat, at a tomperature of
100°, it will then be found to have acquired the property in a
marked degree. The reaclion therefore depends undoubtedly upon
the presence of atbuminose in solution. As the gastric juice, drawn
from the dog'g stomach half an hour or more aflcr the introduction
of food, already contains some albuminose in solution, it prcsenta
the same reaction. If such gastric juice be mixed with a small
quantity of glucose, and Trommer's test applied, no peculiarity is
obeervedon first dropping in the sulphate of copper; but on adding
afterward the solution of pota&sa, the mixture takes a riuh purple hue,
instead of the clear blue tinge which is presented under ordinary
circumstances. On boiling, the color changes to claret, cherry red,
and finally to a light yellow; but no oxide otcopperiadepotiited, and
the fluid remains clear. If the albuminose be present only in small
quantity, an incomplete reduction of the copper takes place, so that
the mixture becomes opaline nnd cloudy, but still without any well
marked deposit. This interference will take place when sugar is
present in very large proportion. We have found that in a mix-
tare of honey and gnstrio juice in equal volumes, no reducUon of
copper takes place on the application of Trommer^a test. It is
remarkable, however, that if such a mixture be previously diluted
with an equal quantity of water, the interference does not take
place, and the copper is deposited as usual.

Usually this peculiar reaction, now that we are acquainted with
its existence, will not practically prevent the detection of sugar,

< Amtrietn Jonrn. M«k1. Boi., Oct. IH54, p. S19.

' Kouvellw roo1)«rc1i«s reUlives fc t'a^ltoii du vuo gutriqne tnr )m BUbftlnuce*
albaniooidM.— Coc. fhbtt. S Fccrier, Ig^S, p. 103.

128

DIOK8TIOH".

wben present; since the presence of the sugar is ilistiDctly indi-
cated b^ iho change of color, as above mentioned, from jmriile to
yellow, though the copper may not be thrown down as a precipi-
tate. All possibility of error, furthermore, ■ may be avoided by
adopting ihe following precauiioiia. The purple color, already men-
tioned, will, in the first place, serve to in<iicotc the presence of the
albuminoid ingredient in the suspected fluid. The mixture should
then be evaporated to dryness, and extracted with alcohol, in order
to eliminate the animal matters. After ihat, a watery solution of
the sugar contained tn the alcoholic extraol will react as usual with
Trommer's teat, and reduce the oslde of copper without difficulty.

Another remarkable property of gnstric jnioe containing albu-
minose, which is not, however, peculiar to it, but common to many
other animal fluids, is that of interfering with the mutual reaction
of starch and iodine. If ^' of such gagtric juico be mixed with 3j'
of iodine water, and boiled starch be subsequently added, no blue
color ia produced ; though if a larger quantity of iodine water be
added, or if the tincture be used instead of the aqueous soiutioo,
the superabundant iodine then combines with the starch, and pro-
duces the ordinary blue color. This property, like that describod
above, is not poaacased by pure, colorless, gastric juice, taken from
the empty stomach, but is acquired by it on being digested with h
albuminoid substances. ■

Another important action which takes place tn the stomach,
beside the secretion of ilie gastric juiw;, ia the jicnttaUie movtmrnt
of the organ. This movement is accomplished by the alternate
contraction and relaxation of the longitudinal and circular fibres
of its muscular coat. The motion ia minutely described by Dr.
Beaumont, who examined it both by watching the movements of
the food through the gastric fistula, and also by introducing into
the stomach the bulb and stem of a thermometer. According to
his observations, when the food first pasaes into the stomach, and
the secretioD of the gastric juice commences, the muscular coat,
which was before quiescent, is excited and begins to contract act-
ively. The contraction takes place in such a manner that the food,
af^er entering the cardiac orifice of the sk)mach, is first carried to
the left, into the great pouch of the organ, thence downward and
along the great curvature to the pyloric portion. At a short distance
from the pylorus, Dr. B. often found a circular constriction of the
gastric parietea, by which the bulb of the thermometer was gently ■
grasped and drawn toward the pylorus, at the same time giving a

GASTRIC JUICE, AND STOUACn DIGESTION. 129

twisting motion to the stem of the iDstrament, by which it was
rotated in hia fingers. In a moment or two, however, this constric'
tioD was relaxed, and the bulb of the thermometer again released,
and carried together with the food along the small curvature of
the 01^11 to its cardiac extremity. This circuit was repeated so
long as any food remained in the stomach; but, as the liquefied
portions were successively removed toward the end of digestion, it
became less active, and at last ceased altogether when the stomach
had become completely empty, and the organ returned to its ordi-
nary quiescent condition.

It is easy to observe the muscular action of the stomach during
digestion in the dog, by the assistance of a gastric fistula, artificially
established. If a metallic catheter be introduced through the fistula
when the stomach is empty, it must usually be held carefully in
place, or it will fall out by its own weight. But immediately upon
the introduction of food, it can be felt that the catheter is grasped
and retained with some force, by the contraction of the muscular
coat. A twisting or rotatory motion of its extremity may also be
frequently observed, similar to that described by Dr. Beaumont.
This peristaltic action of the stomach, however, is a gentle one,
and not at all active or violent in character. We have never seen,
in opening the abdomen, any such energetic or extensive contrac-
tioQS of the stomach, even when full of food, as may be easily
excited in the small intestine by the mere contact of the atmosphere,
or by pinching them with the blades of a forceps. This action of
the stomach, nevertheless, though quite gentle, is snfiicient to pro
dace % constant churning movement of the masticated food, by
which it is carried back and forward to every part of the stomach,
and rapidly incorporated with the gastric juice which is at the
same time poured out by the mucous membrane; so that the
digestive fiuid is made to penetrate equally every part of the ali-
ntentary mass, and the digestion of all its albuminous ingredients
goes on simultaneously. This gentle and continuous movement of
the stomach is one which cannot be successfully imitated in experi-
ments on artificial digestion with gastric juice in test-tubes; and
consequently the process, under these circumstances, is never so
rapid or so complete as when it takes place in the interior of the
stomach.

The length of time which is required for digestion varies in
different species of animals. In the carnivora, a moderate meal of
freah uncooked meat requires from nine to twelve hours for its
9

DtGttSTION.

complete solution and disappearance from the stomach. According
Co Dr. Beaumont, the average time required for digestion in the
human subject is considerably less; varying from one hour to five
hours and a half, according to the kind of food employed. This
is probably owing to the more complete masticnlioD of the food
wbich tnkes place in man, than in the carnivorous animals. By
examining the coutentd of the stomach at various intervals after
feeding, Dr. Beaumont made out a list, showing the comparative
digestibility of diJTerent articles of food, of which the following are
the most important: —
Time required for digestion, according to Dr. BeaumoDt; —

Kixp DP Food. Hocne. MiMrm.

Pig'e feet 1 00

Trip« 1 00

Tront (brailMl) I 80

Venison itoxk 1 3S

Milk 2 00

Roa»l«d tarke/ 2 80

bM«f 8 00

" luulton 3 IS

Tval (broilcHl) 4 00

Snit h«iof (ItoWcA-) 4 IS

Roaattwl pork C IB

The comparative digestibility of diffbrent substances varies more
or lens in different individuals according to temperament; but the
above list undoubtedly givea a correct average estimate of the time
required for stomach digestion under ordinary conditions.

A very intereating question is that which rcklcs to tl^ total
qwaniity of gastric juice secreted daily. Whenever direct experi-
ments have been p'erformed with a view of ascertaining this point,
their results have given a considerably larger quantity than was
anticipated. Bidder and Schmidt found that, in a dug weighing
84 pounds, they were able to obtain by separate experiments, cod-
sumtng in. all 12 hours, one pound and three-quarters of gastrio ■
juice. The total quantity, therefore, for 2i hours, in the same ani-
mal, would be SJ pounds; and, by applying the same calculation to
a man of medium size, the authors estimate the total daily quantity
in the human subject as but little less than H pounds (av.). This
estimate is probably not an exaggerated one. In order to deter-
mine the question, however, if possible, in a different way, we
adopted the following plan of experiment with the gaatric juice of
the dog. It was iirst ascertained, by direct experiment, that the

GASTRIC JUICE, AND STOVACH I>IOBSTION.

131

. lean meat of tbe bullock's hiiart loses, by complete desiccation,
78 per cent, of its weight. 300 grains of such meat, cut into small
pieces, were then digested for ten hours, in 3iss of gastric juice at
100*^ F.; the mixture being thoroughly agitated as oflen as ever;
hour, in order to insure the digestion ofaa large a quantity of meat
as pussibie. The meat remaioiog undissolved wob then collected
on a previously weighed tlltor, and evaporated to dryness. The
dry residue weighed o5 grains. This represented, allowing for the
loss by evaporation, 250 grains of the meat, in its natural moist
condition ; 50 grains of meat were tlien dissolved by Jisa of gastrio
juice, or 33} grains per ounce.

From these data wo can form some idea of the large quantity of
gutrio juice secreted in the dog during the process of digestion.
Oue pound of meat is only a moderate meal for a medium-sized
animal; and yet, to dissolve this quanUly, no less than thirteen pinis
of gastric juice will bo necessary. This quantity, or any approxi-
matioD to it, would be altogether incredible if we did not recollect
that tbe gastric juice, as soon as it has dissolved its quota of food,
i» immatiotefy reabsorbed, and again enters the circulation, together
with the alimentary substances which it hulds iu solution. Tbe
secretion and reabsorption of the gastric juice then go on simulta-
neously; and the fluids which the blood loses by one process are
iDoeaoLntly restored to it by the other. A very large quantity,
therefore, of the secretion may be poured out during the digestion
of a meal, at an ex|>enBe to the blood, at any one time, of only two
or three ounces of fluid. The simplest investigation shows that
llie gtutric juice does not accumulate in the stomach in any coa-
eiderable quantity during digestion; but that it is gradually
secreted so long as any food remains undissolved, each portion, as
it ia digested, being disposed of by rea^xtorption, together with its
solvent fluid. There is accordingly, during digestion, a constant
circulation of tbe digestive Quids from the bloodvessels to the all-
niOQtMry canal, and from the alimentary canal back again to the
bloodvessels,

That this circnlation really takes place is proved by the fol-
lowing facts: First, if a dog be killed some hours after feeding,
there is never more than a very small quantity of fluid found in
the Btoinucti, just sufBcient to smear over and penetrate the half
digested pieces of meat; and, secondly, in the living animal, gastric
jaice, drawn from the fistula Ave or six hours afler digestion has
been going on, contains little or no more organic matter in solution

132

DiaESTIOS.

than that extracted fifteen to thirty minutes after the iritrodiiotion
of fonii. It has evidently been freshly secreted; and, in order to
obtain gastric juice saturated with alimentary matter, it must be
artiflcially digested with food in test-tubes, where this constant ab-
sorption and renovntinu cannat take place.

An unnecessary difficulty has sometimes been felt in understand*
iDg how it is that the gastric juice, which digests so readily all albu-
minous substances, should oot destroy the walls of the stomach
itself, which ara composed of similar materials. This, in fact, was
brought forward at an early dny, as an insuperable objection to the
doctrine of Reaumur and Spallnnzani, that digestion was a process
of chemical solution performed by a digestive fluid. It was said
to be impossible that a fluid capable ol' dissolving animal mutters
should be secreted by tho walls of the stomach without attacking
them also, and thus destroying the organ by which it was itself
produced. Since that time, various complicated hypotheses have
been framed, io order to reconcile these apparently contradictory
facts. Tho true oxplanaLion, however, as we believe, lies in this —
that the process of digestion is not a simple solution, but a catalytic
transformation oF the nlimentary substances, pro^luced hy contact
with the pepsine of the gastric juice. We know that nil the or-
f^anic substances in the living tissues are constantly undergoing, in
the process of nutrition, a scries of catalytic changes, which are
characteristic of the vital operations, and which are determined by
ihe organized materials with which they are in contact, and by all
the other conditions present in the living organism. These changes,
therefore, of nutrition, secretion, &c., necessarily exclude for the
time all other catalyses, and take precedence of them. In the same
way, any dead organic matter, exposed to warmth, air, and moist-
ure, putrefies; but if immersed in gastric juice, at the same
temperature, the putrefactive changes are stopped or altogether^
prevented, because the catalytic actions, excited by the gastric
juice, take precedence of those which constitute putrefaction. For
u similar reason, the organic ingredient of the gastric juice, which
acts readily on dead animal matter, has no eftect on the living
tissues of the stomach, because they are already sul^ect to other
eatalytio intiuences, which exclude those of digestion, as well' as
those of putrefaction. As soon as life departs, however, and the
peculiar actions taking place in the living tissues come to an end
with the stoppage of the circulation, the walls of the stomach are
really jitlackcd by the gostric juice remaining in its cavity, and^i

IHTESTIKAL JUIOSS, DIGESTION OF SUGAR, ETC. 138

ara more or less completely digested aad liquefied. In the hun)an
subject, it is rare to make an exaraioation of the body twenty four
or thirty-six hours al^er death, without finding the mucoua mem-
brane of the great pouch of the stomaoh more or less softcDed and
disintegrated from this cause. Sometimes the mucous membrane
is altogether destroyed, and the submucous cellular layer exposed;
and occasionally, when death ha» taken place suddenly during
active digestion, while the stomach contained an abundance of
gastric juice, all the coats of the organ have been found destroyed,
and a perforation produced leading iulo the peritoneal cavity.
These post-mortem changes show that, after deuth, the gastric juice
really dissolves the coaLs of the stomach without difllculty. But
during life, the chemical changes of nutrition, which are going on
in their tissues, protect them from its influence, and eflectually
preserve their integrity.

The secretion of the gastric juice is much influenced by nervous
conditions. It was noticed by Dr. Beaumont, in his experiments
upon St. Martin, that irritation of the temper, and other moral
causes, would frequently diminibh or altogether suspend the supply
of the gastric fluids. Any febrile action in the system, or any
unusual fatigue, was liable to exert a similar effect Every one is
aware how readily any mental disturbance, such as anxiety, anger,
or vexation, will take away the appetite and interfere with diges-
tion. Any nervous impression of this kind, occurring at the com-
meneemeni of digestion, seems moreover to produce some change
which haa a lasting efleot upon the process; for it is very ofleti
noticed that when any annoyance, hurry, or anxiety occurs soon
after the food has been taken, though it may last only for a few
moments, the digestive process is not only liable to be suspended
fur the time, but to be permanently disturbed during the entire
day. In order that digestion, therefore, may go on properly in the
stomaoh, food must bo taken only when the appetite demands it;
it should also be thoroughly masticated at the outset; and, litmlly,
both mind and body, particularly during the commencement of the
process, should be free from any unusual or disagreeable excite-
ment.

iNTKsnsAL Juices, and the Digestion or Sugar and Starch.
— From the stomach, those portions of the food which have not
already suffered digestion pasj^ into the third division of the ali-
mentary canal, viz^ the small intestine. As already mentioned, U

1S4

DIGESTION.

is oa\y the albuminous matters which are digasted in the stomacli.
Cane sugar, it is true, is stowly converted by the gastric juice, OQt-
side the body, into glucose. Wo have found that ten grains of
cane sugar, dissolved in 5sa of gastric juice, give traces of gluccwe
at the end of two hours; and in three hours, the quantity of thia
substance is considerable. It cannot be shown, however, that the
gastric juice exerts this effect on sugar during onlinary digestion.
If pure cnno sugar be giveu to a dog with a gastric Sstula, while I
digestion of meat Is going on, it disappears in from two to three
hours, without any glucose being delected in the fluids withdrawn
from the stomach. It is, therefore, either directly absorbed under
the form of cane sugar, or passes, lictle by little, into the duodenum,
where the intestinal fluids at once convert it into glucose.

It is equally certain that starchy matters are not digested in the
stomach, but pass unchanged into the small intestine. Here they
meet with the mixed intestinal fluids, which act at once upon the
_8t«rch, and convert it rapidly into sugar. The intestinal fluids,

ten from the duodenum of a recently kilted dog, exert this
Iransforniing action upon starch with the greatest promptitude, if
mixed with it in a test-tube and kept at the temperature of 100** F.
Starch is converted into sugar by this means much more rapidly
and certainly than by the siiliva; and experiment shows that Ibo
intestinal fluids are the active agents in its digestion during life.
If a dog be fed with a mixture of meat and boiled starch, and killed
a short time afler the meal, the stomach is found to contain starch
but no sugar; while in the small intostiiio there is an abundnnoe of
sugar, and bnt little or no starch. If some observers have failed
to detect sugar in the intestin« after feeding the animal with ■
starch, it is because they have delayed the examination until too
late. For it is remarkable how rapidly starchy substances, if pre-
viously disintegrated by boiling, are disposed of in the digestive
process. If a dog, for example, be fed as above with boiled starch
and meat, while some of the meat remains in the stomach for
eight, nine, or ten hours, the starch begins immediately to pass into
the intestine, where it is at once converted into sugar, and then as
rapidly absorbed. The whole of the starch may be converted into
sugar, and curnpletcly absorbed, in an hour's time. We have even
found, at the end of threequarters of an hour, after a tolerably
full meal of boiled starch and meat, that all trace of both starch
and sugar had disappeared from both stomach and intestine. The
rapidity with which this passage of the starch into the duodenum

IXTESTISAL JPICSS, DIGESTION OF SD-GAB, ETC. 135

lakes p1ac« varies, to some ext«iit, in different animals, according
to the general activity of the digestive apparatus; but it ia always
■ comparatively rapid process, when the starch is already liquefied
and is administered in a pure form. There can be no doubt that
the natural place for the digestion of starchy matters ia the small
iuleatine, and that it is aocumplisbed by the action of the intestinnl
juices. '

Our knowledge is not very complete with regard to the exact
nature of the fluids by which this digestion of the starch is aocoro-
plished. The juices taken from the duodenum are generally a
mixture of three different eecretionB, viz., the bile, the pancreatio
Quid, and the intestinal juice proper. Of these, the bilo may be
led out of the question; since it does not, when in a pure state,
exert any digestive action on starch. The pancreatic juice, on the
plher hand, has the property
of converting starch into su- Fig. 3i.

gar; but it is not known
whether this fluid be always
present in the duodenum.
The true inU»tinal Juice is the
prodact of two sets of glan-
dular organs, seated in the
substance of or beneath the
roacoua membrane, viz., the
folliclefl of Lieherktihn and
the glands of Brunuer. The
first of these, orLieberkUhn'a
(blliclcs (Fig. SI), are the most
numerous. They are simple,
nearly straight tubules, lined
vith a continuation of the

intftstinal epithelium, and somewhat similar in their appearance to
the follicles of the pyloric portion of the stomach. They occupy
the whole thickness of the mucous membrane, and arc found in
great numbers throughout the entire length of the limaU aud large
Intestine.

The glands of Brunner (Fig. 82), or the dnodonal glandulo?, as
they are sometimes called, are confined to the upper part of the duo-
denum, where they exist as a closely set layer, in the deeper portion
of the mucous membrane, extending downward a short distance from
the pylorus. They are composed of a great number of rounded fol-

iMtlD* of Dog.

186

DIOBSTTOy.

•4

■
I

r.^'

l^)r(lno of ap« of BnL'nsra'a

Ddovkvai.

licles, clustered round a central excretory duct. Each follicld
consisla of a delicate membranous wall, lined with glandular

epillielium, and covered on
^'S- ^^' its surface with small, dis-

tinctly marked nuclei. The
follicles collected around
each duct are bound together
by a thin layer of areolar tis-
sue, and covered with a plex-
us of capillary bloodTeasels.
The inleslinal juice, which
is the secreted product of the
above glandular organs, has
been less successfully studied
than the other digestiTfl ^H
fluids, owing to the difficulty V
of obtaining it in a pure
state. The method nsualty
adopted ha& been to make au
opening in the abdomen of the living animal, take out a loop of intea- ^
tine, empty it by gentle pressure, and then to nhut off* a portion of ^|
it from the rest of the intealinal cavity by a couple of ligatnrefl,
situated six or eight inches apart; niYer which the loop is returned
into the ab^lumen, and the external wound closed by sutures.
After six or eight hours the animal is killed, and the fluid, which
has collected in the isolated portion of intestine, taken out and '
examined. The above was the method adopted by FrerlchB. Bid- H
dcr and Schmidt, in order to obtain pure intestinal juice, (trst tied
the biliary and pancreatic ducts, so that both the bite and the pan-
creatic juice should be shut out from the intestine, and then estab'
lislied an intestinal listula below, from which they extracted the
fluids which accumulated in the cavity of the gut. From the great
abundance of the follicles of Lieberkiihn, we should expect to find
the intestinal juice secreted in large quantity. It appears, however,
in point of fact, to be quite scanty, as the quantity collected in the
above manner by experimenters lias rarely been sulTicienl for a
thorongh examiaation of its properties. It seems to resemble very
closely, in its [>hysical characters, the secretion of the mucons fol-
licles of the mouth. It is colorless and glassy in appearance, viscid
and mucous in consistency, and has a distinct alkaline reaction.

PANCKEATIC JUICE, AND THE DIOBSTIOy OF FAT. 187

Tt has the property M-hen pure, a8 well as when miaed witli otlier
Bacretions, of rapidly converting starch into sugnr, at the tempe*
TBtQre of the living body.

Pakorkatic Juice, akd thk Digestion op Fat. — The only re-
maioiDg ingredients uf the food that require digestion Are the oily
matters. These are not affected, as we have already stated, by con-
lad with the gastric juice; and examination ttbows, furthermore,
that they arc not digested iti the stomach. So long as they remain
in the cavity of this organ they arc unchanged in iheir essential
properties. Tbey are merely melted by the warmth of the stomscb,
and aet free by the solution of the vesicles, fibres, or capillary tubes
in which they are contained, or among which they are entangled ;
and are still readily discernible by the eye, floating in larger or
smaller drops on the surface of the semi-Quid alimentary mass.
Very soon, however, after its entrance into the intestine, the oily
portion of the food loses its chsractoristic appearance, and is con-
verted into a white, opaque emulaion, which is gradually absorbed.
This emulsion is termed the chyU, and is always found io the small
intestine during the digestion of fat, entangled among the valvulie
coODiventos, and adhering to the surface of the villi. The digestion
of the oil, however, and its conversion into chyle, does not take
place at once upon its entrance into the duodenum, but only after
it has passed the orifices of the pancreatic and biliary ducts. Since
Ibeae ducts almost invariably open into the intestine at or near the
same point, it was for a long ume dilTiuult to decide by wliieh of
the two secretions the digestion of tho oil was accomplished. M.
Bernard, however, first threw some light on this question by ex-
perimenting 00 some of the lower animals, in which the two ducts
open separately. In tbo rabbit, for oxamplo, the biliary duct opens
OS usual just below the pylorus, while the pancreatic duct com-
manicales with the intestine some eight or ten inches lower down.
Bernard fed these animals with substances containing oil, or in-
jected melted butter into the stomach; and, on killing them after-
«rar<l, found that there was no chyle in the intestine between the
opening of the biliary and pancreatio ducts, but that it was abun-
dant immediately below the oriBco of tho latter. Above thia point,
also, he found tlie lacteals empty or transparent, while below it
ihey were full of white and opaque chyle, 'I'he result of these ex-
pcrimeDls, wbich have since been confirmed by Prof. Samuel Jack-

188

DTOESTION.

son, of Philadelpliia,' \vd to the conclusion tb&t tbe pancrentic fluid
is the active agent in the digestion of oily eubstauces; and an ex-
amination of the properties of thta secretion, when obtaineil in a
pDre state from the living animal, fully conRrms the above opinioD.

In order to obtain pancreatic jtiice from the dog, the animal
must be etherizeil soon after digestion has commenced, an iucisioa
made in the upper part of the abdomen, a little to the righc of the
median line, and a loop of the diiodenam, together with th« lower
extremity of the pancreas which lies adjacent to it, drawn oat at
the external wound. The pancreatic ditct is then to be exposed
and opened, and a smalt silver cauula inserted into it and secured
by a ligature. The whole is then returned into the abdomen and
the wound closed by autiirea, leaving only the end of the canula
projecting from it. In the dog there are two panoreatio ducts,
situated from half an inch to an inch apart The lower one of
these, which is usually the larger of the two, is the one best adapted
for the insertion of the canula. Aflcr the eftbcts of etherization
have passed off, and the digestive process baa recommenced, the
pancreatic juice begins to run from the oriBce of the canula, at firat
very slowly and in drops. Sometimes the drops follow each other
with rapidity far a few moments, and then an Interval occurs during
which the secretion seems entirely suspended. After a time it re-
comroencea, and continues to exhibit similar fluctuations daring
the whole course of the experiment Its flow, however, is at all
limes scanty, compared with tliuL of the gastric juice; and we have
never been able to collect more than a little over two fluidonncCT
and a half during a period of three hours, in a dog weighing not
more than forty-fivu pounds. This is equivalent to about 364
grains per hour; but aa the pancreatic juice in the dog ia accreted
with freedom only during digestion, and as this process is in opera-
lion not more than twelve hours out of the twenty-four, the entire
amount of the secretion for the whole day, in the dog, may be esti-
mated at 4,S(>y grains. This result, applied to a man weighing 140
pounds, would give, as the total daily quantity of the pancreatic
juice, about 18,104 grains, or 1.872 pounds avoirdupois.

Pancreatic juice obtained by the above process is a clear, color-
less, somewhat viscid fluid, with a distinct alkaline reaction. Its
composition according to the analysis of Bidder and Schmidt, is aa
follows ; —

1 AmericAn Joam. Umi. Sci., Oct. ISM.

I
I

PANCREATIC JCICB, AKD THB DIOESTIOX OF FAT.

Coiipo6iTn»c or Pancibatic Jiricn.

Watw »0.7«

OiYuic matter (pAiMnMfDa) 00.38

ChlorirlM of ■odium 7.S<

Pr*aiM«U O.SS

rii(MphAt«of sod» 0.4S

fialplmu Df soda 0.10

8>lphue of potuRA O.OS

I L(m« 0.-''4

CombiDiUons ot < MsKiicsla ....... 0,0$

loxidoofiroa 0.03

lOliO.OO

^^^ The most important ingredient of the panareatic juice is its
" organic matter, or pancreatine. It will be seen that this is much
I more flbuDdant in proportion to the other ingredients of the aecre*
I tiun than ibe organic matter of any other dige«live fluid. It is
coagulablo by heat; and the pancreatic juice uf\en solidiQee com-
pletely OD boiling, like white ofogg, so that not a drop of fluid re-
mains after it« coagulation. It ia precipitated, furthermore, by
nitric acid aiul by alcohol, and also by sulphate of magnesia in
excess. By tbid lu»t property, it may he dietinguishod from albu*
men, which is not afTected by contact with sulphate of magnesia.

Fresh pancreatic juice, brought into contact with oily matters at
the temperature of the body, exerta upon them, as wa« Gnst noticed
by Bernard, a very peculiar effect It disintegrates them, and re-
duces them to a state of complete emulsion, so that t)ic mixture is
Bt onc« converted Into a white, opaque, creamy-looking fluid. This
effect is instantaneous and permanent, and only requires that tho
two substances be well mixed by gentle agitation. It is singular
that some of the German observers stiould deny that the pancreatto
jnioe possesses the property of emulsioning fat, to a greater extent
than the bile and some other digestive fluids: and should state that
although, when shaken up with oil, outside the body, it reduces
the oily particles to a slate uf extreme miuuteuesa, the emulsion
is not permanent, and the oily particles "soon separate again on
the aurfaoe."' We have frequently repeated this experiment with
diSbreot apceimens of pancreatic juice obtained from the dog, and
have never failed to see that the emulsion produced by it is by
far more prompt and complete than that which takes place vr
Baliva, gastric juioe, or bile. The effect produced by these fluii

■ Lclunann's rbjr>lologioal Cheuilatrj. PhilMiii. Ad., TOl. I. p. SOT

DIOESTIOy.

ID fact altogether inpignJficanL, in cornpnri»on witli the prompt and
energetic action exerlei) bv the pancreutic jaiiie. The emnlsion
produced with the latter accretion may be kept, lurtherinore, for at
least twenty-four hours, according to our observations, without any
appreciable separation of the oily particles, or a return to their
original condition.

The pancreatic juice, therefore, is peculiar in its action on oily
substances, and reduces them at once to the condition of an emul<
sioQ. The oil, in this process, does not suffer any chemical altera-
tion, ll 13 notdGcotnposnd or saponiQed, to any appreciable extent.
It ia aim p\y emulsioned ; that is, it is broken np into a state of initiuto
subdivision, and retained in suspension, by contact with the organic
matter of the pancreatic juice. That its cbeinical condition is not
altered is shown by the fact that it is still soluble in ether, which
will withdraw the greater part of the fat from a mixture of oil and
pancreatic juice, as well as from the chyle in the interior of the
intestine. In a state of cmulaion, the fat, furthermore, is cupable
of being absorbed, and ita digeslioo may be then said to be accom-
plished.

We find, then, that the digestion of the food ia not a simple
operation, but is made up of several different processes, which
commence successively in different portions of the alimentary
canal. In the first place, the food is subjected in the mouth to tha
physical operations of mastication and insalivation. Reduced to a
soft pulp and mixed abundantly with the saliva, it passes, secondly,
into the stomach. Here it escitea the geeretion of the gastric juice,
by the influence of which its chemical transformation and solution
arc commenced. If the meal consist wholly or partially of mus-
cular flesh, the first effect of the gastric juice is to diwiolve the
intervening cellular substance, by whiuli the tisiiue is disintegrated
and the muscular fibres separated from each other. Afterward
the muscular fibres themselves become swollen and softened by
the imbibition of the gastric fluid, and are finally di3integrated
and liquefied. lu the small intestine, the pancreatic and intestinal
juices convert the starchy ingredients of the food into sugar, and
break up the fatty matters into a fine emulsion, by which they are
converted into chyle.

Although tho separate actions of these digestive 6uids, however,
commence at different points of the alimentary canal, they after-
ward go on simultaneously in the small intestine; and the changea
which take place here, and which constitute the process of tn/esfi'mif

VHENOMESA OF INTESTINAL DIGESTION.

141

digestion^ Form at the same time one of tbe most complicated, and
one of ilie moat important parts of the whole digestive function.

The phenomeaa of inlostinal digt^sliun may be studied, iu the
dog, by killing the animal at various periods after feeding, and
examining the contents of the intestine. We have also auccecded,
hy eatablishing in the same animal an artificial inteatinol fistula,
in gaining still more satisfactory information on this point. The
fistula may l>e established, for this purpose, by an operation precisely
similar to that already described as employed for the production of
a permanent fistula in the stomach. The stiver tube having been
introduced into the lower part of the duodenum, the wound is
allowed to heal, and the inCestiual secretions may then be with-
drawn at will, and subjected to examiuatioa at dlfibrent periods
daring digestion.

By examining in this way, from lime to time, the intestinal
fluids, it at once becomes manifest that the action of the gastric
jaice, in the digestion of albuminoid substances, is not confined to
the stomach, but continues after the food has passed into the intes-
tine About half an hour after the ingestion of a meal, the gastric
juice begins to pass into the duodenum, where it may be recognized
by its strongly-marked acidity, and by ila peculiar action, already
described, in interfering with Tromraer's test far grape sugar. It
baa accordingly already dissolvcti some of the ingredients of the
food while still in the stomach, and contains a certain quantity of
albuminose in solution. It soon afterward, as it continues to pass
into the duodenum, becomes mingled with the debris of muatular
fibres, fat vesicles, and oil drops; substances which are easily
recognizable under the microscope, and which produce a grayish
turbidity in the fluid drawn from the fistula. 1'his turbid admix-
ture grows constantly thiclcer from the second to the tenth or
twelfth hour; after which the intestinal fluids become less abund-
ant, and finally disappear almost entirely, as the process of diges-
tion comes to an end.

The piissage of disintegrated muscular tis3ue into the intestine
may also be showo, as already mentioned, by killing the animal
and examiutng the contents of the alimentary cauul. During the
digestion of muscular fiesh and adipose tissue, the stomach con-
tains masses of softened meot, smeared over with gastric juice, ami
abo a moderate quantity of grayish, grumous fluid, with an acid
reaction. This fluid contains muscular fibres, isolated from each
other, and more or lesa disintegrated, by the action of the gastric

142

DIGESTION.

cs-

Cai'TEi'-r* or gTnii«rn ditriiki Pinsariox
or HiAT. Crom (lie tluir.— a. Pal Vv^IcK fllloil wllh
opaqaa, mlH. griiiiuUrfkl h,lt. Hid »r pirllkllj' di*-
l&tdfMMd miurDlhr Dtira. e. Oil globnloa.

juice. (Fig. 33.) The fat vesicles arc but IlttW or not nt all altered
in the stomach, and there are only a few free oil globules to be

seen Boatiag in the mixed
** ■ fluids, contained in the cavity

of the organ. Id the duode-
num the muscular fibres are
further disintegrated. (Fig.
34.) They becomevery much
broken up, pale and transpa-
rent, but can still be recog*
ni/.ed by the granuhir mark-
ings and flLriaiiona which are
chamoteristio of them. The
fat vesicles also begin to
become altered in the duode-
nam. The solid granular fat
of beef, and similar kinds of
meat, becomes liquefied and
emulsioncd; and appears un-
der the form of free oil drops
and fatty molocnlcs; while
the fat vesicle itself is par-
tially emptied, and becomes
mure or less collapsed and
shrivelled. In the middle
and lower parts of the intes-
tine (l*'iga. So and S6) these
changes continue. The mun-
oolar Sbres become conslanN
ly more and more disinte-
grated, and a large quantity
of granular debris is pro-
duced, which is at last also
dissolved. The fat also pro-
gressively disappears, and the
vesicles may be seen in the
lower part of the intestine,
entirely collnpsed and empty.

In this way the digestion of the different ingredienls of the food
goes on in a continuous manner, from the stomach throughout the
entire length of the small intestine. At the same time, it results

Pig. M.

From Droiiasux or Vto, ptmiFo Dinva-

TIfl!i or Ukat— <i t'tl Vuiklf, irllli It* ciiuiiiiila
dlwIolablDg^. The Tcsl4'l« !■ IjaglimlDg to ulirlitfl kid

Iha tu bTHkiDK Dp. 0,6 DltlDirgntod rautcnlH
flbra. e, r. OH yiti>liult>.

THS LAROB INTB8TINK AND ITS CONTENTS.

143

PioM Middle or Small Ist««ti si.— «, a.
FaL Tmldes, attkrlj ampUed of their eonlentii.

Fig. 36.

in the production of three diifeFent sabstAnces, viz: Ist. Albami*
nose, prodooed by the aotion of the gastric juice on the albuminoid
matters; 2d. An oilj emul-
aioD, produced by the action ^'k* ^*'

of the.panoieatic juiceon fat;
and, 8d. Sugar, produced from
tfae traDBfonnatiDn of starch
by the mixed intestinal fluids.
These substaaces are then
ready to be taken up into the
circulation; and as the min-
gled ingredients of the intes-
tinal contents pass success-
ively downward, through the
dnodenam, jcijuaum, and ile-
um, the products of digestion,
together with the digestive
aeoretioDS themselves, are gra-
dually absorbed, one after
another, by the vessels of the
mnoous membrane, and car-
ried away by the current of
the circulaUon.

The Large InUatine and its
Omienta. — Throughout the
amall intestine, as we have
just seen, tfae secretions are
intended exclusively or main-
ly to act upon the food, to
liquefy or disintegrate it, and
to prepare it for absorption.
But below the situation of the
ileo-cfecal valve, and throngh-
out the large intestine, the
contents of the alimentary canal exhibit a different appearance, and
are distinct in their color, odor, and consistency. This portion of
the intestinal contents, or the feces, are not composed, for the most
part, of the undigested remains of the food, but consist principally
of animal substances excreted by the mucous membrane of the
large intestine. These substances have not been very fully investi-
gated; for although they are undoubtedly of great importance in

Fboh laiit qiriMTiK op Small iNTBirtRB.
-a, a. Fm TeilelM, qnlte empty uid ihrlTelled.

144

DIOBSTION.

regard to llio preservation of healtli, yet the peculinr manner m
which they aro discharged by ihc mucoua membrane and united
with each other in the feces has interfered, to a great extent, with
u thorough investigution of their physiological characters. I

They have been examined, however, by various observers, but "
more particularly by Dr. W. Marcet.' In the contents of the large
intestine, Dr. Marcet foand that the most characteristio ingredient ■
was a peculiar neutral crystal lizable substance, termed ercretine. It
crystal li/.L'S in radiated groups of foiir-sided prismatic needles. It
is insoluble in water, but soluble in ether and slightly so in lUcohol.
It fuses and burns at a high temperature. This substance is non-
nitrogenous, and consists of carbon, hydrogen, oxygen, and sulphur,
ID the following proportions: —

C„H„O.S.
It is thought to be present mostly in a free state, but partly in anioa
with certain organic acids, as a saline componnd.

Beside this substance, the feces contain a certain amount of fat,
fatty acids, cholcsterine, and the reninnrtts of undigested food.
Vegetable cells and fibres may ba detected and some debris of the
disintegrated mu-scular fibres may almost always be found after a
meal composed of animal and vegetable substances. But little
absorption, accordingly, takes place in the large intestine. Its oflica
is mainly confined to the separation and discharge of certain excre-
mentitious substances.

' Id American JouruAl of tlie Mudlcol SoienceB, JftDuar/, l&M.

ABSORPTION.

145

CHAPTER VII.

ABSORPTION.

Beside the glands of Bninner
already described, ibere are, in
intestine, certain glandular*
looking bodies which are
termed "glandulRsoHtariro,"
and "glandulre agmimitio."
The glaadulie solitariw are
globular or ovoid bodies,
about onelbirticth of an inch
in diameter, situated partly
in and partly beneath the in-
testinal mucous membrane.
Each glandule (Fig. 37) la
formed of au investing cap-
anle, closed on all sides, and
containing in its interior a
■oft pulpy mass, which con-
mats of minute cellular bodiea,
imbedded in a homogeneoua
substance. The inclosed mass
is penetrated by capillary
bloodveseeU, which pass in
through the investing cap-
sale, inosculate freely with
each other, and return upon
tbemaelves in loops near the
centre of the glandular body.
There is no ejcteraal opening
or duct; in fact, the contents
of the vesicle, being pulpy
and vascular, as already de-
Bcri bod. are nob to be regarded

and the follicles of Licbcrktihn.
the inner part

ng.37.

the walls of the

f-^i

-^■

Pati;hii«. fTum Rtnall liitDiUB« of Df. UBfalBMl

90 dlunrten.

Ftg. 3S.

\ "'f^

of Pl|. UafDiflrtlSndlaibolcri.

ABaORPTIOW.

aa a i^ccretion, but as constituting a kind of solid glandular tissue.
The glandulffl ogmiiialm (Fig. 38), or "Peyer's patclies," as they are
sometimes cnlledj consist of aggregations of similar globular or
ovoid bodies, found moat abundantly toward the lower extremity of
tbe small intestine. Both the solitary and agmiiiate<l glandules are
evidently connected with the lacteab and the system of the mesen-
teric glands, which latter organs they resemble very much in their
minute structure. They are probably to be reganled as the 6rat
row of mesenteric glands, situated in the wall* of the iatestioal
canal.

Another set of organs, intimately connected with the process of
absorption, are the villi o( the small intestine. These are conical
vascular eminences of the mucous membrane, thickly set over the
whole internal surface of the small intestine. In the upper portion of
the intestine, they are fattened and tnanguhtr in form, resembling
somewhat the conical projections of the pyloric portion of the sto-
mach. In the lower part, they are long and filiform, and often
slightly enlarged, or club-shaped at their free extremity (Kijj. 99),

and frequently attaining the length of
one thirty-fifth of an inch. They are
covered externally with a layer of
columnar epithelium, siinilar to that
whiuh lines iKcj rest of the intestinal

?ig. S9.

of the commencing rootlets of the por-
tal vein. In the central part of the vil-
lus, and lying nearly in its axis, there
is another vessel, with thinner and more
the commencement of a lacteal. The
precise manner in which the lacteal originates in the extremity of
the villus is not known. It commences near the apex, either by a

XxTSBMirr or iFTRtriFAt
Tii.i.ri. from lb* Dog.— a. ItjtrroT
•pIlItcllDni. 6. Hloo4Ti<»rL. a, Lult«l
tomhI.

tntDsparent walls, which is

mucous membrane, and contain in their ■
interior two sets of vessels. The most
superficial of these are the capillnry
bloodvessels, which are supplied in each
villus by a twig of the meaentoric
artery, and which form, by their fre-
quent inosculation, an exceedingly clow I
and abundant network, almost imme-
diately beneath the epithtrlial layer.
They unite at the base of the villus,
and form a minute vein, which is one

AB30KPTT0W.

147

blind extremity or by an irrej^ular plesus, pitssea, in a straight or
somewlint wavy line, toward the base of the villus, and then be*
comes contiDuous witb a small twig of the mesenteric lacteals.

The villi are the active agents in the process of absorption. By
their projecting form, and theirgreat abundance, they increase enor-
mously the extent of surface over which the digested fluids come
in contact with the intestinal mucous membrane, and increase, also,
lo a cor responding degree, the energy with which absorption takes
place. They hangout into the nutritious, semi-fluid mass contained
in the intestinal cavity, as the roots of a tree penetrate the soil ; and
they imbibe the liquefied portions of the food, with a rapidity which
is in direct proportion to their extent of surface, and the activity of
their circalation.

The procaSB of absorption ia also hastened by the peristaltic
moTemenis of the intestine. The muscular layer here, as in other
partfl of the alimentary canal, is double, consisting of both circular
and longitudinal 6brcs. The action of these fibres may be readily
seoD by pinching the exposed intestine with the blades of a forceps.
A contraction then takes place at the spot irritated, by which the
intestine is reduced in diameter, its cavity obliterated, and its con-
tents forced onward into the ancceeding portion of the alimentary
canaL The local contraction then propagates ilaelf to the neighbor-
ing parts, while the portion originally contracted becomes relaxed;
so that a slow, continuous, creeping motion of the intestine ia pro-
ducwl, by successive waves nf contraction and relaxation, which
follow each other from above downward. At the same time, the
loDgiludinal fibres have a similar alternating action, drawing the
narrowed portions of intestine up and down, as they successively
enter into contraction, or become relaxed in the intervals. The efiect
of the whole is to produce a pecullor, writhing, worm-like, or
"vermicular" motion, among the diRe rent coils of intestine. During
life, the vermiL-alar or peristaltic motion of the intestine is excited
by the presence of food undergoing digestion. By its action, the
substanc<>3 which pass from the stomach into the intestine are
steadily carried from above downward, ao as to traverse the entire
loDgih of the small intestine, and to come in contact sueceissively
with the whole extent of its mucous membrane. During this pas-
sage, the abaorpiion of the digested food is c<mstantly going on.
Its liquefied portions arc taken up by the villi of the mucous mem-
brane, and successively disappear; so that, at the termination of the
small intestine, there remains only the urtdigustible portion of the

14!

ABSOBPTTOSr.

food, together, with the refuse of the intestinal secretions,
pass through the ileo-csccal orifice into the large intestine, and thi
liecome reduced to the condition of feces.

The absorplioQ of the digested fluida is accomplished both by
the bloodvessels and the Incteale. It was formerly euppoeed that
the Iftcteala were the only agents in this process; bat it has nov
been long known that this opinion was erroneous, and that the
bloodvessels take at least an equal part in absorption, and are in
some respecta the most active and important agents of the two.
AbundatLt experiments have demonstrated nut only that sohible
substances introduced into the intestine may be soon afterward
detected in the blood of the portal vein, but that absorption ukes
placu more rapidly aud abundantly by the bloodvessels than by
the laoteala. The most decisive of these experiments were those
performed by Paiiiz/.a on the ahlominal circulation.' This ob-
eerver opened the abdomen of a horse, and drew out a fold of tho
amalt intestine, eight or nine inches in length (Fig. 40, a, a), which

Fig. 40.

FjiauiA'* BirsatWKiT.— «tA IniMtlne. h. Point of llnlai«af mtMiilrrie T*1a. « Optnta^
In talntlna fur lairuducUon of polaob. d. Op*(il[)slBii»«Diaric *•)□ balilad lb* llgaiimL

ho included between two ligatures. A ligature wns then placed (at
5) upon the mesenteric vein receiving the blood from this portion
of intestine; and, in order ihnt the circnlation might not be inter-
rupted, an opening was made (at d) id the vein behind the ligature, I

' In Mnttiiuaci'i L«ctiir«s on tbe Phjrsic!.! I'heDomeui of Living Ueinga, Pvniia'a
•dltton, p. 83.

ADSORPTIOK.

149

90 tbat ttie blood brought by the ineaonteric artery, afler circuluting
in tho intestinal capillaries, possed out at tho opening, and v>a>*
collecterl in a vessel for examination. Hydrocyanic acid was tlien
introduced into the intestine by an opening at e, and almost imme-
diately afterward its presence was detected in the venous bloo<l
flowing from the orifice at d. The aniinnl, however, was uot pui-
iH>ned, since tlic ncid wms prevented from gaining an entrance into
the genera] circulation by the ligature at b.

Panizza afterward varied this experiment in the following man-
ner: Instead uf lying the nieseoteric vein, he simply compressed it.
Then, hydrucyanic acid being introduced into the intestine, as above,
no eflet.n wa-s prodiicc<l on the animal, so long as compression was
inniutntned U|>on the vein. But as soon as the blood was allowed
lo pass again through the vessels, symptoms of general poisoning
at onco became manire»t. Ltistly, in a tliird experiment, ihu 8»mo
observer removed all the nerves and lacteal vessels supplying the
intestinal fold, leaving the bloodvessels alone untouched. Hydro-
cyanic acid now being introduce<:l into the inte«tinc, found an
entrance at once into tho general circulation, and tho animal was
immediately poisoned. The bloodvessels, therefore, are not only
capable of absorbing fluids from the intestine, but may even take
ibem Dp more rapidly and abundantly than the lacteals.

These two sets of vessels, however, do not absorb all the nliment-
ary matters iDdiscriminately, It is one of the most important of
the facts which have b^en established by modern researches on
digestion that the diflerent substances, produced by ibe operation of
the digestive fiuids on the food, pass into the circulation by different
routes. The fatty matters are taken up by the lacteals under the form
of chyle, while the saccharine and albuminous matters pass by ab-
sorption into the portal vein. Accordingly, after the digestion of a
meal containing starchy and animal matters mixed, albuminose and
sugar are both found in the blood of the portal vein, while they can*
Dot be detected, in any large quantity, in ibe contents of ihe lacteals.
These aubstances, however, do not mingle at once with the general
masB of the circulation, hut owing to the anatomical distribution of
the portal vein, pass first through the capillary circululion of the
liver. Soon after being introduced into the blood and coming in
contact with its organic ingredient;), they become altered and con-
verted, by catalytic trans t'unnat ion, into other substances. The
albuminose passed into the condition of ordinary albumen, and
probably also partly into that of fibrin; while the sugar rapidly

150

lBSORPTION.

■.ij.A.^V*, ■-,-.

becomes decomposed, and loses its charactemtie propcrUea; so
that, on arriving at the entrance of tlio general circulation, both
these newly absorbed ingredients have become already assimilated
to those which previously existed in the blood.

The chyle in the intestine consiata, as we have already mentiooed,
of oily matters which have not been chemically altered, but simply
reduced to a state of emulsion. In chyle drawn from tbe laotesla
or the thontcio duet (Fig. 41), it still presents itself in the same

condition and retains all the
^''S;*^" chemical propertiea of oil.

Examined by the microscope,
it is seen to exist under tha
form of dne granules and
moleculea, which present the
ordinary appearances of oil
in a state of minute subdtvi*
sion. Tbe chyle, therefore,
does not represent the entire
product of the digestive pro-
cess, but contains only the
fatty substances, suspended
by emulsion in a serous fluid.
During the time that intes-
tinal absorption is going on,
after a meal containing fatty
ingredients, the lacteaia may be seen as white, opaqne vessels, dis-
tended with milky chyle, passing through the mesentery, and con- ■
verijing from its inteatinal border toward the receptaculum chyli,
near the spinal column. During their course, thoy pass througb
several successive rows of mesenteric glands, which also become
turgid with chyle, while the process of digestion is going on. The
lacteals then conduct the chyle to tbe receptaculum chyli, wheocifl
it passes upward through the thoracic duct, and is Anally dis-
charged, at tho tern^instion of this canal, into the left, subclavian
vein. (fig. 42.) It is then mingled with tha returning current of
venous blood, and passes into the right cavities of the heart.

The lacteals, however, are not a special system of vessels by them>
selvc>), but are siin ply & part of the great sytitom of " absorbent" or
"lymphatic" vessels, which are to bo found everywhere in the integu-
ments of the head, the parietes of the trunk, the upper and lower
extremities, and in the muscular tissues and mucous membranes

CHTt.* raoa covMsvemtiiT c» Tiiogijicie

t>DeT, rroiti lh« Da«. — The molraiil** ruj Id aliv
rrum l-IO.OOath of m Inch duirainrd-

ABSORPTION.

151

thmaghout the hady. The walls uf ihese vessels are thinner and
more transparent than thuso of the arteries and veins, and they are
consequently less cnsily de-
lected by ordinary dissection. Kg. 42.
They originate in the tissues
of the above-mentioned parts
by on irregolnr plexus. They
pass from the extremities to-
ward the trunk, con vergingand
uniting with each other like ihe
veins, their principal branches
talcing usually the same direc-
tion with the nervesand blood-
vessels, and passing, at various
points in their course, through
certain glandular bodies, the
"lymphatic" or "absorbent"
glands. The lymphatic glands,
among which are included the
mesentericglands, consist of an
external layer of fibrous tissue
and a contained pulp or paren-
chyma. The investing layer
of fibrous tissue sends off thin
•eptA or laminro from its inter-
nal surface, which penetrate
the substance of the gland in
every direction and unite with
each other at various points.
In this way they form an interlacing laminated framework, which
divides the substance of the glund into numerous rounded spaces
or alvuoli. These alveoli are not completely isolated, but commu-
nicate with each other by narrow openings, where the intervening
septa are incomplete. These cavities are filled with a soft, reddish
pulp, which is penetrate'], according to Kulliker, like the solitary
and agtninated glauds of the itite^tine, by a fine network of capil-
lary bloodvessels. The solitary and agmtnated glands of the intes-
tine are, therefore, closely analogous in their structure to the lyni-
phatics. The former are to be regarded as simple, the latter as
compound vascular glands.
The arraugemcnt of the lymphatio vessels in the interior of the

W./ .

LicTtALa, TiinkAric DccT, kt.—n. Intm-
lin*. t. V«Ba <»*■ Vatfrior. r, f. III|M koil laft
■olicladaD T»la*. d. PuLal of opsolnf of Ukoracio
4a«t Isiu Wtl anlwlK'Ika.

152

ABSORPTIOSr.

glftntJs in not precisely understood. Ench lymphatic vessel, as
enters ihe gland, breaks up into & number of minute ramifications,
the voic affervitia; and other aimilar twigs, forming the vasi cfftr-
eniia, pass off in the opposite direction^ from the farther side of the
gland ; but the exact mode of communication between the two has
not been definitely ascertained. The fluids, however, arriving by
the vnsa afferentia, must pass in some way through the tissue of
the gland, before they are carried away again by the vosq efferentita
Frotn the lower extremities the lympliatio vessels enter the aWomcn
at the groin and converge toward the receptaculum chyli, into
which their fluid is discharged, and afterwar^I conveyed, by the
thoracic duct, to the left subclaviau vein.

The fluid which these vessels contain is called the b/mph. It is
a colorless or slightly yellowisli transparent fluid, which is absorbed
by ihc lymphatic vessels from the tissues in which they originate.
So far as regards its compositiou, it is known to contain, beside,
water and saline matters, a small quantity of ilbrin and albumeiu
Its ingredienta are evidently derived from the metamorphosis of
the tissues, and are returned to the centre of the circulation in
order to be eliminated by excretion, or in order to undergo some
new transforming or renovating process. Wo are ignorant, how-
ever, with regard to the precise nature of their character and
destination.

The laoteals are simply that portion of the absorbents which
originate in the mucous membrane of the small intestine. During
the intervals of digestion, these vessels contain a colorless and
transparent lymph, entirely similar lo that which is found in other
parts of the absorbent system. After a meal containing only
starchy or albuminoid substances, there is no apparent change in
the character of their contents. But aller a meal containing fatty
matters, these substances are taken up by the absorbents of the
intestine, which th<>n become fJIled with the white chylous emul-
sion, and assume the appearance of lacteals. (Fig. 43.) It is for
this reason that lacteal vessels do not show themselves lapon the
stomach nor upon the first few inches of the duodenum ; because
oleiiginous matters, as we have seen, are not digested in the stomach,
bat only after ihey have entered the intestine and pas-sed the orifice
of the pancre.atic duct.

The presence of chyle in the lacteals is, therefore, not a con-
stant, but only a periodical phenomeaon. The fatty substances
constituting the chyle begin to be absorbed during the process of

154

ABSORPTION.

known. They are, at all events, so altered in the bIoo<1, while
passing through the lungs, that they lose the fornri of a fatly cmul-
aioQ, and are no longer to be recognized by the usual testa for
oleaginous subatances.

The absorption of fat from the intestine is not, however, excla-
sively performed by the lacteala. Some of it is aljw taken up,
uader the same form, by the bloodvessels. It has been aacertatned
by the experiments of Bernard' thai the bliKid of iho mesenteric
veins, in the carnivorous animaU, contains, during intestinal diges-
tion, a considerable amount of fatty mntter in a state of mtnate
subdivision. Other observers, also (Lehman n, Schultz, Simon), have
found the bluud of the portal vein to be considerably riuber in fat
than that of other veins, particularly while tntiistinal digestion is
going on with activity. In birds, reptiles, and fish, furthermore,
according to Bernard, the intestinal lymphatics are never 611ed
with opaquecb^le, but only with a transparent lymph; so that these
animals may be said to be destitute of lactcals, and in them the fatty
substances, like other Qltmeniary materials, are taken up altogether
by the bloodvessels. In quadrupedsf, on tlie other hand, and id
the human subject, the absorption of fat is accomplished both by
the bloodvessels and the laoteals. A certain portion is taken up
by the former, while the BU[>crubun dance of the fatty emulsion is
absorbed by the latter.

A difficulty has long been experienced in accounting for the ab-
sorption of fat from the intestine, owing to its being considered ns a
non-endosmotic substance ; that is, as incapable, in iis free or undis-
solved condition, of penetrating and passing through an animal
membrane by endoismosis. It is stated, indeed, that if a fine oily
emulsiun be placed on one side of an animal membrane in an endoa-
momoter, and pure water on the other, the water will rearlily pene-
trate the substance of the membrane, while the oily particles cinnot
Ije made to pass, even under a high pressure. Though this be true,
however, for pure water, it is not true for slightly alkaline Hutds,
like the serum of the blood and the lymph. This has been de-
monstrated by the experiments of Maiteucci, in which ho made
&n emulsion with an alk.ilinc fluid containing 43 parts per thou-
sand of caustic potassa. Such a solution has no perceptible alkaline
taste, and its action on reddened litmus paper is about equal tu

' hti^ait dtt Phjii)ol(i)jiw Esp.:fiinniLtaln. f&riii, IbSO, p> 325.

ABSUBPTIOir.

166

that of the lympli and chyle. If this emulsion were placed in an
eodoamometer, tt^ether with a watery alkaline solution of similar
strength, it was found that the oily particles penetrated through the
animal membrane without much difficulty, and mingled with the fluid
on the opposite side. Although, therefore, we cannot explain the
exact mechanism of absorption in the case of fat, still we know
that it is not in opposition to
the ordtnary phenomena of ^*" **"

eudosmosis ; for endosmosia
will take place with a fatty
emulsion, provided the fluids
used in the experiment be
slightly alkaline in reaction.
It is, accordingly, by a pro-
cess of endosmosis, or imbi-
bition, that the villi take up
the digested fatty snbstanoes.
There are no open orifices
or canals, into which the oil
penetrates ; but it passes di-
rectly into and through the
Babstance of the villi. The '^""'

epithelial cells covering the external surface of the vill us are the first
active agents in this absorption. In the intervals of digestion (Fig.
44) these oells are but slightly

tuTKiTiirAL Epitbilidm; rroiD IbsDag.vhIl*

granular and nearly trans-
parent in appearance. But if
examined during the diges-
tion and absorption of fat
(Fig. 45), their substance is
seen to be crowded with oily
particles, which they have
taken up from the intestinal
cavity by absorption. The
oily matter then passes on-
ward, penetrating deeper and
deeper into the substance of
the villus, until it is at lost
received by the capillary ves-
sels and lacteals in its centre.

Fig. 45.

IvriaTiNAL Bpithilidm; tnu th« "Dog, Ant'
iag iIm dIgMilon of tu.

1KB

AHSOBPTrOW.

' The fatty substances takoD up by the portal vein, like those nb-
Horbed by the lauieals, do not at once enter the general circulation,
but pasB first through the cnpillary system of the liver. Thence
they are carried, with the blood of the hepatic vein, to the right
side of the heart, and subsequently through the capillary system of
the lungs. During this passage they become altered in character,
as above described, and lose for tbo moHt part the distinguishing
characteristics of oily matter, before they hare passed beyond the
pulmonary circulation.

But as digestion proceeds, an increasing quantity of fatty matter
finds its way, by these two passoges, into the blood; and a time at
last arrives when the whole of the fat so introduct-d is not destroyed
during its passage through the lungs, lis absorption taking place
at this lime more rapidly than its decomposition, it begins to ap-
pear, in moderate quantity, in the blood of tbo general circulation ;
and, lastly, when the intestinal absorption 13 at its point of greatest
activity, it is found in considerable abundance throughout the
eniire vascular system. At this period, some hours after the inf^es*
tion of fond rich in oleaginous mattera, the blood of the general
circulalion everywhere contains a superabundance of fat, derived
from the digestive process. If blood be then drawn from the veins
or arteries in any part of the body, it will present the peculiar
appearance known as that of "chylous" or "milky" blood. AfWr
the separation of the clot, the serum presents a turbid appearance;
and the fatty substances, which it contains, rise to the top after a
few hours, and cover its surface with a partially opaque and creamy-
looking pellicle. This appearance has been occasionally observed
in the human subject, particularly m bleeding for apoplectic attacks
occurring after a full meal, and has been mistaken, in some instances,
for a morbid phenomenon. It is, however, a perfectly natural one,
and depends simply on the rapid absorption, at certain periods of
digestion, of oleaginous substances from the intestine. It can be
produced at will, at any time, iu the dog, by feeding him with fut
meat, and drawing blood, seven or eight hours afterward, from the
carotid artery or the jugular vein.

This state of things continues for a varying length of time, ac-
cording to the amount of oleaginous mattera contained in the food.
When digestion is terminated, and the fat ceases to be introduced
in unusual quantity into the circulation, its iransformation and
decomposition continuing to take place in the blood, it disappears
gradually from the veins, arteries, and capillaries of the general

ABSORPTION. 167

Bystem ; and, finally, when the whole of the fat has been disposed
of by the nutritive processes, the serum again becomes transparent,
and the blood returns to its ordinary condition.

In this manner the nutritive elements of the food, prepared for
absorpttoD by the digestive process, are taken up into the circulation
under the different forms of albuminose, sugar, and chyle, and accu-
mulate as such, at certain times, in the blood. But these conditions
are only temporary, or transitional. The nutritive materials soon
pass, by catalytic transformation, into other forms, and become
assimilated to the preexisting elements of the circulating fiuid.
Thus they accomplish finally the whole object of digestion ; which
is to replenish the blood by a supply of new materials from without.
There are, however, two other intermediate processes, taking place
partly in the liver and partly in the intestine, at about the same
time, and having for their object the final preparation and perfec-
tion of the circulating Quid. These two processes require to be
studied, before we can pass on to the particular description of the
blood, itself. They are: Ist, the secretion and reabsorption of the
bile; and 2d, the production of sugar in the liver, and its subsO'
quent decomposition in the blood.

158

THE BILE.

CHAPTER Vlir.

THE BILE.

The bile is more easily obtained iu a stale of purity than any
otlier of the secretions which find their way into the intestinal
canal, owing to the existence of a gall-bladder in which it accu-
mulates, and from which it may be readily obtained without any
other admixture than the mucus of the gall-bladder itself. Not*
withstanding thi8^ itj study Iiaa proved an unusually difficult one.
This difficulty has resulted from the peculiar nature of the biliary
ingredients, and the readiness with which they become altered by
chemical manipulation ; and it is, accordingly, only quite recently
that we liave arrived at a correct idea of its real constitution.

The bile, as itcumcs from the gall-bladder, is a somewhat viscid
and glutinous fluid, varying in color and specific gravity according
to the species of animal from which it is obtained. Uuman bile is
of a dark golden brown color, ox bile of a greenish yellow, pig's
bile of a nearly clear yellow, and dog's bile of a deep brown. We
have found iho specific gravity of human bile to be 1018, that of
ox bile 1024, that of pig's bile 1030 to 1080. The reaction of the
bile with teat-paper cannot easily be determined; since it has only
a bleaching or decolorizing effect on litmus, and does not turn it
either blue or red. It is probably either neutral or very slightly
alkaline. A very characteristic physical property of the bile is
that of frothing up into a soap-like foam when shaken in a test-
tube, or when air is forcibly blown into it through a small glass
tube or blowpipe. The bubbles of foam, thua produced, remaio fl
for a long time without breaking, and adhere closely to each other
and to the sides of the glass vessel.

The fallowing is an analysis of the bile of the ox, based oq the
calculations of Berzelius, Frerichs, and Lehmaun: —

THB BILK. 159

CoHFOflmoK or Ox Bilb.

Water 886.00

Otyko-choUte of soda i

TmnMshoUta " " J ^**-^

BillrerdiDe

Fata

01«ates, margArstes, and atearates of soda and potasu 13.42

Cholesterin

Chloride of Bodinm

Phosphate of soda

" " lime 15.24

" " magneflla

Carbonatei of soda and potassa

Hdviu of the gall-bladder 1.34

1000.00

BiLiVBBDrNS. — Of the above mentioned ingredients, btliverdine
is pecaliar to the bile, and therefore important, though not pre-
sent in large qnaotity. This is the coloring matter of the bile.
It is, like the other coloring matters, an uncrystallizable organic
Bobstance, containing nitrogen, and yielding to ultimate analysis a
small quantity of iron. It exists in such small quantity in the bile
that its exact proportion has never been determined. It is formed,
80 far as can be ascertained, in the substance of the liver, and does
not pre-exist in the blood. It may, however, be reabsorbed in
cases of biliary obstruction, when it circulates with the blood and
Btaina nearly all the tissues and fluids of the body, of a peculiar
lemon yellow color. This is the symptom which is characteristic
of jaundice.

Gholxsterik (C„n„0). — This is a crystallizable substance which
resembles the fats in many respects ; since it is destitute of nitrogen,
readily inflammable, solnble in alcohol and ether, and entirely in-
soluble in water. It is not saponifiable, however, by contact with
the alkalies, and is distinguished on this account from the ordinary
&tty substances. It occurs, in a crystalline form, mixed with color-
ing matter, as an abundant ingredient in most biliary calculi ; and
is found also in different regions of the body, forming a part of
various morbid deposits. We have met with it in the fluid of
hydrocele, and in the interior of many encysted tumors. The
crystals of cholesterin (Fig. 46) have the form of very thin, color-
less, transparent, rhomboidal plates, portions of which are oflen
cutout by-lines of cleavage parallel to the sides of the crystal.
They frequently occur deposited in layers, in which the outlines of

160

THB BILB.

the subjacent cr^'stals show very distinctly througb the sabstance

of those which are placed above.
Fig. 43.

r-i

r \

Cholesterin is not formed in the
liver, but originates in the
Biibstancfl of the braiD and
nervous tissue, from which
it mny bo extracted in lar^e
qaantity by the action of
alcohol. From these tissues
it is absorbed by the blood,
tlien conveyed to the liver,
and discharged with the bile.

The fatty substances and
inorganio saline ingredients I
of tho bile require no special
description.

Caoi:KiT(Bia, rraioko EarpiwITunur.

BiLiABY Salts. — By far
the most important and characteristic ingredients of this secretion
are the two saline substances mentioned above aa ihe glyko-efiolatf
and taurochoiate of soda. These substances were first discovered
by Strecker, in 1848. iu the bite of tlio ox. They are both freely
soluble in water and in alcohol, but insoluble in ether. One of
them, the tauro-cholate, has the property, when ilaelf in soliition ■
in water, of dissolving a certain quantity of fat; and it is probably
owing to this circunDstancc thai some free fat is present in the bile.
The two biliary substances are obtained from ox bile in the follow-
ing manner: —

The bile is first evaporated to dryness by tho watcr-hath. Tho
dry residue is then pulverized and treated with absolute alcohol, ia
the proportion of at least 5j of alcohol to every five grains of dry
residue. The filtered alcoholic solution has a clear yellowish color.
It contains, beside the glyko-cholatc and inuro-cholate of soda, tha
coloring matter and more or less of the fats originally present in ■
the bile. Oo the addition of a small quantity of ether, a dense,
whitish precipitate is formed, which disappears again on agitating
and thoroughly mixing the fluids. On the rcpeatwl addition of
ether, the precipitate again falls down, and when the ether has been
added in considerable excess, six to twelve times the volume of the
alcoholic solution, the precipitate remains permanent, and the whole
mixture is filled with a dense, whitish, opaque deposit, consisting

THB BILX.

161

of the gl^ko-cholatc and uinro-chokte of soda, thrown down under
the form of heav^ flakes and granules, pari of which subside to
the bottom of tlie tetjt-tubo, white part remain for a time in suspen-
BiDD. Gradually these flakes and grannies unite with each other
and fuHe together into clear, brownish-yellow, oily, or resinous*
looking drops. At the bottom of the teftt-tubc, aflcr two or three
hours, there is usually collected a nearly homogeneous layer of
this deposit, while the Temainder continues to adhere to the sides
of the glass, in small, circular, transparent dmps. The deposit is
semi-fiuid in consistency, and sticky, like Canada balsam or half-
melted resin; and it is on this account that the ingredients compos*
ing it have been called the "resinous matters" of the bile. They
have, however, no real oheraical relation with true resinous bodies,
since they both contain nitrogen, and diflcr from resins also in
other imjiorlant particulars.

At the end of twelve to twenty-four hours, the glyko-ofaolate of

soda begins to crjstalliae. The cryHlals radiate from various points

in the resinous deposit, and shoot u[iward into the supernatant

fluid, in white, silky bundles. (Fig. 47.) If some of thesw crystals

Fig. 47. Fig. 48.

Oif KD-ci>ii.AT» or »"Dt ta,ca Ox-iii.b,

nR") iwo l^ltJ*' CT]ra(>itl1(>t!i>u. At llin ^urirr pari ol
lli« tfnn Ilia prjciaU an nfttlna laia dr-^p*, tr*ta lb<
oispvnllaa vf llio ctbtr *ud aliHitpllitu u( niuUlura

be removed anil examined by the microscope, they are found to be
of a very delicate aoiuular form, running to u Snely pointed
extremity, and radiating, as already mentioned, from a central
U

102

THE BItE.

point. (Fig. 48.) As the ether evaporates, tlie crystals obsorb
moisture from the air, and melt np mpidly into clear resinous
drops; so that it is difficult to keep them under the micnMCope
long enough for a correct drawing and measurement. Thecrystal-
lizatioa ia the test-tube goes on aEler the first day, and tho crystals
increase in quantity for three or four, or even five or six days, until
the whole of the glyko-cholate of soda present has assumed ths
solid form. The tauro-cholate, however, is UDCry stall izable, and
remains in ao amorphous condition. If a portion of the deposit be
DOW removed and examined by the microscope, it is seen that the

crystals of glyko-cholate of

Fl„. 4!l.

^o.

soda have increased conside-
rably in thickness (Fig. 49),
so that their transverse dia-
mutor may be readily esti-
mated. The uncrysUUlizabte
taufo-cbolate appears under
the form of circular drops,
varying considerably in size,
clear, transparent, strongly
refractive, and bounded by
a dark, well-deGucd outline.
These dropt are not to be distin-
guiahed, by any of their optical
}jro^^r(iei,/ivm<Hi-ghbulet, as
they usually appear under
the microacoi>e. They have ■
the same refractive power,
tbe same dark outline and bright centre, and the same degree of
consistency. They would consequently be liable at all times to be
mistaken for oil-globules, were it not for the complete dissimilarity
of their chemical properties.

Both the glyko-cholate and tauro-cholate of soda are very freely
soluble in water. If the mi.\ture of alcohol and ether be poured
off and distilled water added, the deposit dissolves rapidly and
completely, with a more or less distinct yellowish co3or, according
to the proportion of coloring matter origiually present in the bile.
The two biliary substaoces present in the watery solution may lie
separated from each oilier by the following means. On the addi-
tion of achate of lead, the glyko-choEate of soda is decomposed, ■
and precipitates as a glyko-cholate of lead. The precipitate, scpa-

Gl.Tln-rH<iL17« A**t Ttirio-onoLjTK or

Soda, r%l^» ox-niL*, afrar tlx •!•;«' cmialllu-
iteO- Tlin gif ki.-rlii>lsU U urjiMlllaMl ; Uio Ikujo-
«bo)M« la tn Buld drop*.

TBE filLB.

16S

r»te<l by 61lration from the remaining fluid, \S then decomposed in
Luni by carbonate of soda, and the original glyko-cholato of soda
reproduced. The filtered fluid which reinuins, aud which contiiios
ihe tauro-cholatc of soda, is then treated with subac/tfale nf lead,
which precipitates a taiiro-cholate of lend. This is aeparatod by
filtration, crashed, and decomposed again by carbonate of soda, as
in the former case.

The two biliary substances in ox bile may, therefore, be dis*
tinguished by their reactions with the aalw of lead. Both arc
precipitable by the Bubacetate; but the glyko-cholate of soda is
precipitable also by the acetate, while the tauro-cbolate in not so.
If subacetate of lead, therefore, be added to the mixed watery solu-
tion of Ihe two substancea, and the wiiolo filtered, the aubsequent
addition of acetate of lead to the filtered floid will produce no pre-
tipilate, because both the biliary matters have been entirely thrown
[down with the deposit; but if the acetate of lead be first added, it
fill precipflatc the glyko-cholale alone, and the tauro-cholatc may
aderward be thrown down separately by the subacetate.
These two substances, examined separately, have been found to
leaeee the following propcrlicii: —

QlyhydtohUe of eoda {NaO.C'j,H„NOj,) crystallizes, whan precipi-

lied by ether from its alcoholic solution, in radiating bundles of

ine white silky needles, as above described, it is composed of

aaited with a peculiar acid of organic origin, viz., glyko-cholic

r«ci'{^(C„H^NO,„I10]. This acid iacrystalli/.able and contains nitro-

[fcn, as «hown by the above formula, which is that given by Lch-

^tnann. If bolted for a long time with a dilute solution of potaasa,

glyko-cholic acid is decomposed with the prmiuction of two new

subslaiicos; the Aral a non-nitrogenous acid borly, choUc acid

''(C.j^^OpjHO); the aecoad a nitrogenous neutral body, ghjeinc

(CfHjNOJ. Ileooe the name, glyko-cholio acid, given to the

original substance, as if it were a combination of oholic ucid with

glycine. In reality, however, these two substances do not exist

originally in the glyko-cholic acid, but are rather new combinations

of its elements, produced by long boiling, in contact with potassa

and water. They are not, therefore, to bo regarded as, iu nny way,

natural ingredients of the bile, and do not throw any light on the

real oonsiitution of glyko-cholic acid.

lyxuro-ckolaU of $oda (NaO,C„n^,NS,On) is also a very abundant
ingredient of the bile. It is said by Kobiii and Verdeil' that it is

■ Clilmlv An&toiutiiUi; vt l'li,rnii>lt)>iiqai», vol- >i. p. 4?.^.

164

TITB BILE.

not crystallizable, owing probably to its rot having been separated
OS yet in a jjerfectly pure co^ndition. Lehmann stales, on tbe con-
irary, that it may crystallize,' when kept for a long time in contact
with ether. Wc have not been able to obtain this substance, how-
ever, in a crystalline form. Its acicj conslhucni, ianro cfioUc acid,
is a nitrogenous body, like glyko-cholic acid, but differs from the
latter by containing in addition two equivalents of sulphur. By
long tioiling in a dilute solution of potassa. it is decomposed with
the prod ucilon of two other substances ; the first of them the san;e
acid body mentioned above as derived from tho glyko-cholic, viz.,
ehoitc acid; and the second a new nitrogenous neutral body, via.,
lourim (C,II,NS,0,). The same remark holds good with regard to
these two bodies, that wo have alreaily niadu in respect to the sup-
posed constituonui of glyko-cholic acid. Neither cholic acid nor
taurine can be properly regarded as really ingredicnta of tauro-
cholie acid, but only as artificial products reaulting from its altera-
tion and decomposition.

Tho glykocholates and taurocholatea are formed, so far as wc
know, exclusively in the liver; since they have not been found in
the blood, nor in any other part of the body, in healthy animals;
nor even, in the experiments of Kunde, Molesehott, and Lehmann
on frogs,* afler the entire extirpation of the liver, and consequent
suppression of the bile. These substances are, therefore, produced
in the glandular cells of the liver, by transformation of some other
of their ingredients. They are then exuded in a soluble form, as
jiart of the bile, and finally discharged by the excretory hepatic
ducts.

The two substanoea described above as the tauro-cholalc and
glyko-cholate of soda exist, properly speaking, only in the bile of
the ox, where they were first discovered by Strecker. In examin*
ing the biliary secretions of difl'erent species of animals, Streckor
found so great a resemblance between them, that he was disposed
to regard their ingredients as essentially the same. Having estab-
lished the existence in ox-bile of two peculiar substances, one
crystallizable and noo-3ulphuxous(glyko-cholate),the other uncrys-
tnllizable and sulphurous (Uiuro-cholale), be was led to consider
ihe bile in all species of animals as containing the same substances,
and as differing only in the relative quantity in which the two

' I'hyeiological Chomlilry, Phil, ed., T(*1. I. p. 20fl.

• l..-liniaiiii'» I'hydidogical Clieiiiiitrv, t'ltil. wd., rol, 1. p. 4715.

THB BILL

165

Klg. 50.

were preaent. TVie only excepiion to this was snpposed to be pig's
bile, in which Strecker foond a peculiar organic acid, tlie "hyo-
obotic" or "hjro-cbulinic" acid, in cumbinatiou wilb soda as a biistf.

The above concluaioo of his, bonrever, was not entirely correct.
It is true that tlio bile of nit animals, so far as examined, contains
peculiar substances, which resemble each other in being freely
soluble in wftter,8oluble in absolute alcohol.and insoluble in ether;
and iu giving also a peculiar reaction with Pettcnkofer's test, to be
desenbed presently. But, at the same time, these substances pre-
sent certain ininordifTerences in difiorontnnimnla, which show thoin
Dot to be identical.

In dog's bile, for example, there are, as in ox-bile, two substances
precipitoble by ether from their alcoholic solution ; one crystalliz-
able, the othernot so. But the former of these substances crystallizes
much more readily than the glyko-cholate ofsoda from ox-bile. Dog's
bile will not unfrcqueiiily begin to crystallize freely iu five to six
hours after precipitation by ether (Fig. 60); while
in ox-hilc it is usually twelve, and of^en twenty-
four or even forty-eight hours before crystalliza-
tioD is fully established. But it is more particu-
larly in their reaction with tha salts of luad thai.
the diflerence between these Mubstances becomes
manifest. For while the crystal lizable substance
of ox-bite is precipitated by acetate of lead, th:it
of dog's bile is not aflectcd by it. If dog's bile
be evoi>oroted to dryness, e.xtracted with absolute
alcohol, the alcoholic solution precipitated by
ether, and the ether precipitate then dissolved
io water, the addition of acetate of lead to the
watery solution produces not the slightest tur-
bidity. If subacetnte of lend be then added in
exixa&t a copious precipitate fulls, composed of
both the crystallizable and uncrystallizable sub-
staooes. If the lead precipitate be then separated
by filtration, washed, and decomposed, as above
described, by carbonate of soda, the watery solu-
tion will contain the re-formed soda salts of the
bile. The wat*'ry solution may then be evaporated to dryness,
extracted with abfiolute alcohol, and the alcoholic solution precipi-
tated by ether; when the ether precipitate crystallizes partially

no.i'aRii. p.«xlliw(-
oit Willi alwalulaalfoliol
■till iirirlpllaWd wlih
MhM.

1G6

TBE BlLt;.

Pig. 51.

after a time, as in fresh bile. Both tKe biliary matters of dog's bile
are therefore preci[>itable by ^ubacutatt; of Itjail, but neither of them
by tbe acetate. Instead ofcalliDg tbein, eoDsequently, glyko-cholate
and tatinj-diolate of suila, we shall apeak of tliem simply as the
"crystalline" and "r&sinous" biliary siibstant^cs.

In cat's bile, the biliary subatancee act very much as in dog's
bile. The ether-preci|)itatu uf the alcohuliu soliiliou conlains here
also a cryalallino and a rc^tnaus substance; both of which are
precipitable from their watery soIuEioa by subacetate of lead, but
neither of them by the auotate.

In pig's bile, on the other hand, there is no crystallizable sub-
stance, but tlio ethcr-procipiliite is altogether resinous in appear-
ance. Notwithstanding this, its watery solution precipitates abun*
dantly by both the acetate and subacetate of lead.

In human bile, agaiu, there \a uo Qrystallizablo substance. We
have found that the dried bilo, extracted with Absolute alcohol,
makes a clear, brandy-red solution, which precipitates abundantly
with other in cxccj«; but the ether- precipitate, if allowed to stand,
shows no sign of crystallization, even at tbe end
of three weeks. (Fig. 51.) If the resinous preci-
pitate bo separated by deeanlation and dissolved
in water, it precipitates, as in the case of pig's
bile, by both the acetate and subacetate of lead,
Tliia might, perhaps, be attributed to the pre-
sence uf two ditl'ei'ent substances, as in ox-bile,
one precipitated by the acetate, the other by the
subacetate of lead. Such, however, is not the
case. For if the watery solution be precipitated
by the acetate of load and ihau filtered, the GItcreil
fluid gives no precipitate afterward by tbe sub-
acetate ; and if first precipitated by the subacetate,
it gives no precipitate after filtration by the ace-
tate. The entire biliary ingredients, therefore, of
human bile are precipitated by both or cither of
the salts oflead.

Diflcrent kinds of bile vary also in other re-
spects; as, for example, tbcir specific gravity, the
depth and tinge of their ctdor, the quantity of fat
which they contain, ic. &c. "We have already
mentioned the variations iu color and specific gravity. The alco-
holic solution of dried ox-bile, furllicruioro, does iiol precipiiate at

IU- K * H B 1 1, n , «x-

■lenliiil iDil |ir>irij>Hiil-

pd 1)7 Mh«r.

I
I
I

TESTS FOR BII.H.

187

ill on ihe addition of walor; wbile that of Iiumnn bile, of pig's
biie, ami of dog's bile precipitate nbundanlly with distilled wiiier,
owing to t!ie quantity of fat which iliuy hold in solution. Those
variationa, however, are of secondary importanoe oonipnred with
thorn which we have already mentioned, and which show that the
crystalline and resinous substauces in diHcrent kinds of bile, though
resembling each other In very many respects, are yet in reality far
from being idonticat.

Tests fob Bir.K. — In investigating tlic physiology of any animal
fluid it is, of course, ot the Brat importance to have a convenient
find reliable teat by which its presenoo may be detected. For a.
long time the only test emplnyeil in the case of bile, was that which
depended on a change <y' wlor produced by oxidizing substance*. If
the bile, for example, or a mixture containing bile, be exposed in
an open glass vessel for a few hours, ihe upper layers of the fluid,
which are in contact with the atmosphere, gradually assume a
greenish tinge, which becomes deeper with the length of time which
elapaea, and the quantity of bile existing in the fluid. Nitrie acid,
added to a mixture of bile and shaken up, produces a dense preci-
pitate which lakes & bright grass-green hue. Tincture of iodine
produces the same change of color, when added in small quantity;
and probably there are various other substances which would havo
the same effect. It is by this test that the bile has so oflen been
reoogniiied in the urine, f;erous effusions, the solid tissues, &c., in
oaaea of jaundice. liut it is very insufhcient for anything like
accurate investigation, since the appearances are produced simply
by the action of an oxidizing agent on the coloring mutter of the
bile. A green color produced by nitrio acid does not, therefore,
indicate the presence of the biliary substances projier, but only of
the biliverdine. On the other hand, if the coloring matter be ab-
■ent, the biliary substances themselves cannot be detected by it
For if the biliary substances of dog's bile be precipitated by ether
from an alcoholic solution, dissolved in water and decolorized by
nnicnal charcoal, the colorleas watery solution will then give no
green color on the addition of nitric acid or tincture of iodine,
though it may precipitate abundantly by subacetate of lead, and
give tlio other reactions of the cryatalliue and resinous biliary
maiters in a perfccity distinct manner.

PtUerdofe/'a Teal, — This is undoubtedly the best test yet pro*
poaed for the detection of the biliary substances. It consists tn

Ifi8

TBS BII.S.'

mixing with r watery solution of the bile, or of the hiliary sab
stances, a little cane sugar, and then adding sulphuric acid to the
mixture unlit a red, lake, or purple color is produced. A solution
may be made of cane sugar, in the proportion of one part of sugar to
four parts of water, and kept for use. One drop of this solution is
mixed with the auspectcd fluid, and the sulphuric acid then imme-
diately added. On 6r8t dropping in the sulphuric acid, a whitish
jirecipitate falls, which is abundant in the cast! of ox-bile, less so in
that of the dog. This precipitate redJsaolvea in a slight excess of
sulphuric acid, which should then continue to be added until the
mixture assumes a somewhat syrupy conaiatcncy and an opalescent
look, owing to the devetopmenl of miuutu bubbles of air. A red
color iheQ begins to show itself at the bottom of the test-tube, and
afterward spreads through the mixture, until the whole fluid is of
a clear, bright, cherry red. This color gradually changes to a lake,
and finally to a deep, rich, opaque purple. If three or four vol-
umes of water be then added to the mixture, a copious precipitate
falls down, and the color is destroyed.

A''ariou3 circumBtaaces modify, to some extent, the rapidity and
distinctness with which the above changes are produced. If the
biliary substances be present in large quantity, and nearly pure,
the red color shows it<iclf at once alter adding an equal volume of
sulphuric acid, aud almost immediately passed into a strong purple.
If they be scanty, on the other hand, the red color may not show
itself for seven or eight minutes, nor the purfde under twenty
or twenty-five minutes. If foreign matters, again, not oF a biliary
nature, be also present, they are apt to be acted on by the sulphuric ■
acid, and, by becoming discolored, interfere with the clearness and
brilliancy of the tinges protlueed. Ou this account it is indispen-
sable, in delicate examinntions, to evaporate the suspected fluid to
dryness, extract the dry residue with absolute alcohol, precipitate
the alcoholic solution with ether, and dissolve the ether-precipitate
in water before applying the test. In this manner, all foreign sub-
stances which might do harm will be eliminated, and the test will '
succeed without difficulty.

It must not be forgotten, furthermore, that the sugar itself la
liable to be acted on and discolored by sulphuric acid when added
in excess, and may therefore by itself give rise to confusion. A little
care and practice, however, will enable the experimenter to avoid
all chance of deception from this source. When sulphuric acid is
mixed with a watery solution containing cane sugar, after it has

TESTS FOR B!LB.

169

beeu added in considerable excess, a yellowtab color begins to show
itself, owing to the commencing decomposition of ihe sugnn This
color gradually deepens until it has become a dark, dingy, muddy
brown; but there Is oever at anytime any clear red or purple
oolor, unless biliary matters bo presunt. If the bile be present in
but small quantity, the colors produced by it may be modified and
(ibftcured by the dingy yellow and brown of the sugnr; but even
this difficulty may be avoided by paying attention to the following
precautions. In the first place, only very little augnr should be
added to the suspected fluid. In the aecond place, the sulphuric
acid should bo added very gradually, and the mixture closely
watched to detect the first changes of color. If bile be present, the
red color peculiar to it is always procluced before the yellowish
tinge which indicates the decomposition of the sugar. When the
biliary matters, therefore, are present in small quantity, the add!-
tion of sulphuric acid should be stopped at that point, and the
colors, though faint, will then remain clear, and give unmistokablc
evidence of the presence of bile.

I'he red color alone is not sufScient as an indication of bile. It
is in fact only the commencement of the change which indicates the
biliary matters. If these matters bo present, the color pa8.ses, as
we have already mentioned, first into a lake, then into a purple;
and it is this lake and purple color alone which can ba regarded as
really characteristic of the biliary reaction.

It is important to observe that Pettenkofer'a reaction ia produced
by the presence of either or both of the biliary substances proper;
and is not at all dependent on the coloring matter of the bile. For
if the two biliary substances, crystalline and resinous, be extracted
by the process above de9crlbe<l, and, after being dissolved in water,
decolorized with animal charcoal, the watery aolution will still give
Pettcnkofer's, reaction perfectly, though no coloring matter be pre-
sent, and though no green tinge can be produced by the addition
of nitric acid or tincture of iodine. If the two biliary aubstaDces
be then separate^l from each other, and tested in distinct solutions,
each floluiion will give the same reaction promptly and completely.

Various objections have been urged against this test It has
been stated to be uncertain and variable in its action. Hubio and
Verdeil' say that its reactions "do not belong exclusively to thfi
bile, and may therefore give rise to mistakes." Som''

170

THB BILE.

slnnccs and Tolatile oils (olein, oleic acid, nil of turpentine, ait
caraway) have been 8tatffll to produce similnr red and violet colors,
when treated with sugar aud sulphuric acid. These objections,
however, have not much, if any, practical weight. The test no
doubt rtfquires some care and practice in its application, aa we have
already pointed out; but this is the case also, to a greater or le&s
extent, with nearly all chemical tcsia, and particularly with those
for substances of organic origin. No other substance is, in poinl
of Tact, liable to be met with in the intestinal fluids or the bloody
which would simulate the rcnctions of the biliary matters. Ws
have found that the fatty matters of the chyle, taken from the tho-
racic duel, do not give any coloration which would be mistaken for
that of the bile. When the volatile oils (caraway and turpentine)
are acted on by sulphuric acid, a red color is produced which afler-
ward becomes brown and blackish, and a peculiar, tarry, empyreu-
matic odor is developed at the same time; but we do not get the
lake and purple colors spoken of above, finally, if the precaution
be obiierved — ilrst of extracting the suspected matters with absolute
alcohol, then precipitating with ether and dissolving the precipitate
in water, no ambiguity could result from the presence of any of thd ■
above substances.

Tettenkofer's test, then, if used with care, is extremely useful,
and may lead to many valuable results. Indeed, oo other test than I
this can be nt all relied on to determine the presence or absence of
the biliary substances proper. ^

V.^RiATiONS .AND FUNCTIONS OP BitE. — With regard to the
aitire qttant\(y of HU sfcreted daily, we have had no very positive
knowledge, until the experiments of Bidder and Schmidt, published
iu ltt52.' These experiments were performed on cats, dogs, sheep,
and rabbits, in the following manner. The abdomen was o|>ened|
and a ligature place*! upon the ductus coinmiinis eholedochus, sa
as to prevent the bile finding its way into the intestine. An open-
ing was then made in the fundus of the gall-bladder, by which
the bile was discharged externally. The bile, so discharged, was
received into previously weighed vessels, and its quantity accurately
determined. Each observation usually occupied about two hours,
during which period the temporary fluctuations occasionally observ-
able iu the quantity of bile discharged were mutually correctod| so

V«ril.ianEMa«rU! uixl SiolTnocliMl. L«l|iii£, ISflS.

VARIATIONS AND FUNCTIONS OF DILE. 171

IT as the entire result was concerned. Tbo nttinriAl was then killet],
weighed, and carefully examined, in order to make sure that the
biliary duct had boon securely tied, and that no inflnmmntory alter*
ttion had taken place in the abdominal organs. The obatirvations
were made at very diiTerent periods after the lost meal, so as to
determine the influence exerted by tlio digestive procc8fl upon the
rapidity of the secretion. The average quantity of bile for twenty-
four hours was then calculated from a comparison of the above
results; and the quantity of iU solid ingredients wai^ also ascer-
tained in each instance by evaporating n portion of the bile in the
water bath, and weighing the dry residue.

Bidder and Schmidt found in this way that the daily quantity
of bile varied considerably in different species of animals. It was
very much greater in the herbivorous animals used for experiment
than in the carnivora. The results obtained by these observers
are as follows:—

For every pound weight of the entire body there is secreted
daring 2i hours

pBKaK Bite. Dsr Rbkiovb.
Id llic eat ...... 10'.! jcrAJni. &.7Vi grn\a».

" dog . . . . 1*1 " fl.916 "

■ rtewp 179 " S.4H8 "

- nhUt &58 " 17.S80 "

Since, in the human subject, the digestive processes and the
nutritive actions generally resemble those of ihe carnivora, rather
iban those of the herbivora, it is probable that the daily quantity
of bile in man is very similar to that in the carnivorous animals.
If we apply to the human subject the average results obtained by
Bidder and Schmidt from the cat and dog, we find that, in an adult
man, weighing 140 pounds, the daily quantity of the bile will be
certainly not lese than 16,9^0 grains, or very nearly 2^ pounds
avoirdupois.

It is a matter of great importance, in regard to the bile, as well
the other intestinal fluids, to ascertain whether it be a eotisiant

sretion, like the urine and perspirniion, or whether it bo intennil'
IaU, like the gastric juice, and discharged only during the digestive
procesB. In order to determitie this pointy we have performed the
following scries of experiments on dogs. The animals were kept
confined, and killed at various periods af^cr feeding, sometimes by
the inoculation of woorara, sometimes by hydrocyanic acid, but
most frequently by section of the medulla oblongata. The con-

172

tenia of the intestine were then collet^tciJ and exnmined. Tn »!!

itistancos, the bile was alao taken from ihe gall-bladder, and treat«<l

in the same way, for purposes of comparison. The intestinal con-

tentaalwaya prcacnted some peculiaritiea of appearance when treated

with alcohol and ether, owing probably to the presence of other

BuK'itanees than the bile; but they always j^uve evidencM) of the

presence of biliary matters um welt. The biliary substances could

almost elwuys be recognized by the microscope in the etheri)reci'

pitato of the alcoholic solution; the resinous substance, ander the

form of rounded, oily-looking drops (Fig. 62), and the other, ander

the form of crystalline groups, generally presenting the appearance

of double bundlosuf slender,
I'ig. 52. 1 ■ 1- I 1 1

radiating, slightly curved or

wavy, needle-shaped crys-
tals. These substances, dis-
solved in water, gave a pur-
ple color with sugar and
sulphuric acid. These ex-
periments were tried after
the animals had been kepi
for one, two, three, five, six,
seven, eight, and twelve
days without fooil. The
result showed that, la all
these instances, bile was pre-
sent in the small intestine.
It is, therefore, plainly not
an intermilteot secretion,

nor one which is concerned exclusively in the digestive process;

but its secretion is constant, and it continues to bo disehargc<l into

the intestine for many days after the animal has been deprived of

food.

The next point of importance to he examined relates to the frme
after feeding at wKidi the bile pojscj into the inUsllnc m the rftraltst
atninJaiice. Bidder and Schmidt have already investigated this
point in the following manner. They operated, as above dei^cribed,
by tying the common bileduct, and then opening the fundus of the
gall-bladder, so as Ut produce a biliary fistula, by which the whole
of the bile was drawn of!'. By doing this operation, and collecting
and weighing the Suid discharged at different periods, they came

• TA><^l*i fnn BciibII iBtMlInn at Oaf. a/Ral two daj**
IkatlBl.

VARIATIONS AND yUNCTlONS OF BIT.B.

173

to the conclaaion that the Sow of bile begins tr> irtoreaee within ivro
and a hair hours after the introduction of food into the stomach,
but that it does not ren^^h its maximum of activity till the end of
twelve or flftuen hours. Otlier observers, however, have obtained
diflbrent results. Arnold,* for example, found the quantity to be
largest soon aller meals, decroawing again after the fourth hour.
Koilikcr and MUllcr,* again, found it largest between the sixth and
eighth hours. Bidder and Schmidt's experiments, indeed, strictly
qteaking, show only the titne at which the bile is most activuly
Mcrctcd by the liver, but not when it is uotually discharged into
the intestine.

Oar own experiments, bearing on this point, were performed on
dogs, by making a permanent
duo<1enal listula, on the same "*' **'

plan that gaatrio Hstulfe have so
dh.tn been established for the
examination of the gastric juice.
(Fig. 53.) An incision was made
throagh the abdominal watts, a
short distance to the right of
the medtan line, the floating
portion of the daodenum drawn
up toward the external wound,
opened by a longitudinal inci-
noQ, and a silver tube, armed

>t each end with a narrow

pmjevting collar or flange, in-

Berled into tt by one extremity,

five and a half inches below the

p^'lurua, and two and a half

inches below the orifice of the

bwer pancreatic duct. The

'iW extremity of the tube was

Wl projecting from the external

opening in the abdominal pa-

rietes, the parts secured by suturea, and the wound allowed to heal,

AlW cioatrization was complete, and the animal had entirely

fKovcred his healthy condition and appetite, the iiitcslinal fiuids

*ere drawa offal various intervals after feeding, and their contents

DcDDiNAL. Kr<Tt)l.t.~Hi. Stomieh. b Duo<
ilcuiiiii r, e. e ranriviu; lu inn durin xrs •r>fa
oiioniof fntu llii i]ai>dBDUin, one ui-ir [lie orlAe*
u( III* hlhur; duM. 4, Ihs mhar n >lii)n dUUiiec
law<r down r. Sllrer tub« pitcluf itif<iugli (hi
■lliliiinllilll •ralla taA a)>«iilD|r Inli] ttia iluuitannn,

' til Au. Jqhri. HwI. Scl.,.Apri1. 1890.

Ibid., April, 1657.

1T4

TQK BIT.G.

oxamincd. Tbis operation, which is rather moredifftcull tbnn Ui
of making a permanent gastric fistula, is oevertheleaa exceedingly
useful when it succeeds, since it enables 119 to study, not only the
lime and rate of the biliary discharge, bat also, as mentioned in a
previous chapter (Chap. VI.), maay other extremely interesting
tnattera connected with inteatinul digestion.

In order to ascertain the absolute quantity of bile discharged
into the intestine, and its variations during digestion, the duodenal
fluids were drawn 0% for fifteen minutes at a time, at various
periuda alter feeding, collected, weighed, and examined separately,
as follows: each separate quantity was evaporated to dryness, ita
dry residue extracted with absolute alcohol, the alcoholic solution
precipitated with ether, and the ether- precipitate, regarded as repre-
senting the amount of biliary matters present, dried, weighed, and
then treated with Pettenkofer's test, in order to determine, as nearly
as possible, their degree of purity or admixture. The result of
these experiments is given in the following table. At the eigh-
teenth hour so small a quantity of fluid was obtained, that the
amount of its biliary ingredients was not ascertained. It reacted
perfectly, however, with Petteiikofer's test, showing that bile
really pre3ent.

Tlmo ifK-r

tttiaoll^r <if(llliil

brf riwlcloo

Qimnltlf of

Pro("itlti«i of

fri-Jlmg.

Irj 1.1 tuiuutck.

udutmo.

bills ly luktlrfi

III drjr ffikl^Bf*,

Itntuc^dlAlul^

fi4i> grains

33 grains

lOgntina

.30

1 hour

l.ltftO ■•

105 "

4 "

.03

8 boutv

760 "

60 "

4 "

.07

6 '■

760 '*

73 "

34 •■

.06

9 "

HIHl "

78 "

4} "

.08 '

IS "

325 "

23 "

S* '■

.16

16 "

Ml "

18 "

4 "

.82

18 "

ai "

384 "

11 "

J "

.00

24 ..

lfi3 "

M "

31 '•

.34

25 "

151 "

6 »

3 ♦'

.«>

From this it appears that the bile passes iulo the intestine in by
far the largest quautity immediatuly afler feeding, and within the
first hour. AHer that time its discharge remains pretty constant;
not varying much from four grains of solid biliary matters every
fideen niinutes, or sixteen grains per hour. Tbe animal used for
the above observations weighed thirty-six and a half ponnds. ■

The next point to he ascertained with regard to this question is
the following, viz: What hea>mes of the hie in its passage throxtijh
the inlestiueP Our experiments, performed with a view of settling

VARIATIONS ANP FCKCTIONS OF BILE.

176

(his point, wero tried on dogs. Tho animals were fed with fresh
ineat,and then killed at varioas intervals after the meaU, the abdo-
men openei3, lignlures placed upon the intestine at various points,
Hud the contents of its upper, middle, and lower portions collected
and examined Bepamtelj. The results thus obtained bIiow that,
under ordinary circumstance^ the bile, which is quite abundant in
the duodenam and upper part of the small iutestiae, dimiuisbes in
quantity from above downward, and is not to be found in the large
intestine. The entire quantity of the intestinal contents also dimi-
nishes, and their consiatcney increases, as we approach the ileo-
cecal valve ; and at tbe same time their color changes from a light
yellow to a dark bronze or blackieth-groeo, which is always strongly
pronounced in the IobI quarter of the smalt intestine.

Tbe contents of tbe small and large intestine were furthermore
evaporated to dryness, extracted with absolute alcohol, and tho
alcoholic solutions precipitatud with ether; the quantity of ctber-
precipilate being regarded as representing approximatively that of
the biliary substances proper. The result showed that the quantity
of this ether-precipitate is, both positively and relatively, very much
toss in tbe large intestine than in tbe small. Its proportion to the
entire solid contents is only one-fltlh or ono-sixth as great in iha
large intestine as it is in the small. But even this inconsiderable
quantity, found in contents of the large intestine, docs not con-
sist of biliary matters; for tbe watery solutions being treated witb
tagar and sulphuric acid, those from both tbe upper and lower
portions of the small intestine always gave Pettenkofer'a reaction
promptly and perfectly in less Uian a minute and a half; while in
that from the large intestine no red or purple color was produced,
even at tbe end of three hours.

The small intetitine consequently contains, at all times, substances
giving all the reactions of tbe biliary ingredients; wbilu in the
coQients of the large intestine no such substances can be recognized
'oy Pettcnkofcr's test.

The biliary matters, therefore, disappear in their passage through
the intestine.

In endeavoring to ascertain what is the precise /unrtiOT of (he bile
in Uic inCesChu:, our first object must be to determine what ])arl, if
wy, it takes in the digestive process. Aa the liver is situated, like
the salivary glands and the pancreas, in the immediate vicinity of
ihe alimentary canal, and like tbero, discharges its secretion into

176

ihe cavity of the intestine, it seema at Brst natural to regard the
bile na one of the digestive fluids. Wc have previously shown,
however, that the digestion of nil the different elements of the food
is provided for by other secrellona ; and furtliermore, if we exaniiQe
experimentally the digestive power of bile on alimentary sabstaDces.
we obtain only a negative result. Bile exerw no special actioD upon
oithcr ftlburoinoid, starchy, or oleaginous matters, when mixed with
them in test-tubes and kept at the temperature of 100° F. It baa
iberefore, apparently, uq direct iufluence in the digeatiuD of iboBa
substances.

It is a very rcmarkuble fact, in this connection, that the bile pre-
cipitates hy eonfact with the gastric juice. If four drops of dog'a bile
be added to 5j of gastric juice from the same animal, a copious 1
yellowish white precipitate fulls down, which contains the whole of
the coloring matter of the bile which baa been added; and if the
mixture be then filtered, the filtered fluid passes through quite
colorless. Tbe gastric juice, however, still retains its acid reaction. I
Tbis precipitation depends upon the presence of the biliary sub-
stances proper, viz., the glyko-cholate and tauro-chulate of soda, and
not upon that of the incidental ingredients of the bile. For if the
bile be evaporated to dryness and the biliary substances extracted
by alcohol and precipitated by ether, as above described, their
watery solution will precipitate with gastric juice, in tbe same
manner us fresh bile would do.

Although the biliary matters, however, precipitate by contact
with fresh gastric juice, iftc^ ilo hqI do so with gastric Juice which hoUU
aUfuminose in solution. We have invariably found that if the gas-
tric juice bo digested for several hours at the temperature of 100'
F^ with boiled white of egg, the filtered fluid, which contains an
abundance of albuminose, will no longer give the slightest precipi*
tate on the addition of bile, or of a watery solution of tbe biliary
substances, even in very large amount. The gastric juice and tbe
bile, therefore, are not finally antagonistic to each other in the
digestive process, though at first they produce a precipitate on
being mingled together.

It appears, however, from the experiments detailed above, that
the secretion of the bile and its discharge into the intestine are not
con6ned to the periods of digestion, but take place constantly, and
continue even after tbe nnimal hEis been kept for many days with-
out food. These facts would lead us to regard the bite as simply
an extrementitious jiuid : contaiaing only ingredients resulting from

VABIATIONS AND FUNCTIONS OP BILB.

177

waste and disintegration of the animal lissucs, and not intended
to perform any ]>articular function, digestive or otherwise, but
merely to be eliminnted from the blood, and discharged from the
eystom. The same view \a more or less supported, also, by the
following facta, vig: — ■

1st. The bile is prodaced, unlike all the other animal nccretious,
from venous blood; that i?, tlie blood of the portal veio, which has
already become contaminated by circulation through the abdominal
organs, and may be sup[>oscd to contain disorganized ami eiteie
Jngredients; and

2d. Its complete suppression produces, in the human nubject,
)ma of poisoning of the nervous system, analogous to those
fallow the suppression of the urine, or the stoppage of respi-
ration, and the pnlient dies, usually in a comatose condition, at the
end of ten or twelve dnys.

The above circumstances, taken together, would combine to
make it appear that the bile ia simply an uxcremeutitioua fluid, not
necessary or useful as n secretion, but only destined like the urine,
to be eliminated and discharged. Nevertheless, experiment has
sbowQ that such is not tlie case; and that, in point of fact, it is
necessary for the life of the animal, not only that the bile be aecreted
attd discharged, but furthermore that it be discharged into tbd
intestine, and pass through the tract of the alimentary ciinal. The
most satisfactory experiments of this kind are those of Bidder and
Schmidt,' in which they tied the common biliary duct in dogs, and
theu established a permanent fistula in the fundus of the gall-bladder,
through which the bile was allowed to flow by a free external urilice.
In this manner the bile was effectually excluded from the intestine,
but ai the same time was freely and wholly discharged from the
body, by the artificial fistula. If the bile llierefore were simply an
excrementitious fluid, itsdeletcrioua ingredients being alt eliminated
as usual, the animals would not suffer any serious injury from this
operulion. If, on the contrary, they were found to sufter or die in
consequence of it, it would show that the bile has really some im-
portant function to perfurrn in the inteistinal canal, and is not simply
excrementitious in its nature.

The result showed that the eflects of such an ex|)ennient were
fatal to the animal. Four doga only survived the immediate eftects
of the operation, and were aflerwar*.! frequently used for purposes

178

THE 13ILE.

of cxporimcnt. One of them was an animal from wliicfa the apleen
hnd been previously removed, and whose appetite, as usual after
this operation, was morbitlly ravenous; his system, accordingly,
being placed uoder such unnatural conditions as to make him an
unfit subject for further experiment. In the second animal that
survived, the communicution cf the biliary duct with the intestine
became re-established after ci^^hteen days, and the experiment con*
aequently had no result. In the remaining two animals, however,
everything was sueccsaful. The fistula in the gall-bladder became
permanently establislieJ ; and the bile-duct, as was proved subse-
quently by post-mortem examination, remained completely closed,
so that no bile found its way into the intestine. Both these ani-
mals died ; one of them at the end of twenty-seven days, the other
at iho end of thirty-six days. In both, the ayniptoms were nearly
the same, viz., constant and progressive cmnciation, which proceeded
to such a degree that nearly every trace of fat disappeared from the
body. The loss of flesh amounted, in one case to more than two-
fifths, and in the other to nearly one-half the entire weight of the
animal. There was also a falling off of the hair, and an unusually
disagreeable, putrescent odor in the feces and in the breath. Not-
withstanding this, the appetite remained good. Digestion was not
essentially interfered with, and iiono of the food was dischargiMl
with the feces; bui there was much rumbling and gurgling in the
intestines, and abundant discharge of flatus, more strongly marked
in one instance than in the other. There was no pain; and death
took place, at last, without any violent symptoms, but by a simple
and gradual failure of the vital powers.

now IB it, then, that although the bile bo not an active agent in
digestion, its presence In the alimentary canal is still essential to
life? What ofiice does it perform there, and bow U itiinally dis-
posed of?

We have already shown that the bile disappears in ita passage
through the intestine. This disappearance may be explained in
two diSisrent ways. First, the biliary matters may be actually re-
absorbed from the intestine, and taken up by the bloodvessels; or
secondly, they may be so altered and decomposed by the intestinal
fluids as to lose the power of giving Pettenkofcr'a reaction with
sugar and sulphuric acid, and so pass oft' with the feces in an
insoluble form. Bidder and Schmidt' have Snally determined thi^

■ Op. cit.p. 217.

VARIATIONS AND FUNCTIONS OF BILK. 179

point in a aatisfactory manner; and have demonstrated that the
biliary substances are actually reabsorbed, by showing that the
quantity of sulphur present in the feces is far inferior to that
contained in the biliary ingredients as they are discharged into the
intestine.

These observers collected and analyzed all the feces passed, dur-
ing five days, by a healthy dog, weighing 17.7 pounds. The entire
fecal mass during this period weighed 1508.15 grains,

CoDUinmg I ^•'«" 874.20 grains.

I Solid reBidne 633.95 "

IfiOS.lfi

The solid residue was composed as follows: —

Nentnl fat, soluble in ether . 43.710 grains.

Fat, with traces of hilitnj matter . 77.035 "

Alcohol extract with biliarj matter 58.900 containing 1.085 grs. of snlphnr.

Sabatanoes not of a blliarj natare

extracted by mariatio acid and

hot aloohol .... 148.800 contolning 1.302 grs. of salphor.

2.367
Fatt/ acids with oxide of iron . 98.426
Beaidne consisting of hair, sand, Ac, 207.080

633.950

Now, as it has already been shown that the dog secretes, daring
21 hours, 6.916 grains of solid biliary matter for every pound weight
of the whole body, the entire quantity of biliary matter secreted
ID five days by the above animal, weighing 17.7 pounds, must have
been 612.5 grains, or nearly as much as the whole weight of the
dried feces. But furthermore, the natural proportion of sulphur
in dog's bile (derived from the uncrystallizable biliary matter), is six'
per cent of the dry residue. The 612.5 grains of dry bile, secreted
daring five days, contained therefore 36.75 grains of sulphur.
But the entire quantity of sulphur, existing in any form in the
feces, was 5.952 grains ; and of this only 2.387 grains were derived
from substances which could have been the products of biliary
matters — the remainder being derived from the hairs which are
always contained in abundance in the feces of the dog. That is,
not more than one-fifleenth part of the sulphur, originally present
io the bile, could be detected in the feces. As this is a simple
chemical element, not decomposable by any known means, it must,
accordingly, have been reabsorbed from the intestine.

We have endeavored to complete the evidence thus furnished by

180

TUK J3ILK.

Bidder and Schmidt, and to demonstrate dirvctly the reabsorptioiT
of the biliar_v matterii, by searching for ihatn in the ingredients of
the portal blood. We )iave examined, fur this purpose, the portal
blood of dog3, killed ot vnrious periods after feeding. The animals
were killed by section of the medulla oblongata, a ligature imme-
ilialely placed on the portal vein, while the circulation ivas still
active, and the requiBite quantity of blood collected by opening
the vein. The blood was sometimes immediately evaporated to
(Irync&s by the water bath. Sometimes It was coagulated by boil-
ing in a porcelain capsule, over a spirit lamp, with water and an
excess of sulphate of sodo, and the filtered watery solution after-
ward examined. Hut moat frequently the blood, after being col-
lected from the vein, was coagulated by the gradual addition of
three times its volume of alcohol at nineiy-five per cent., stirring
the mixture constantly, so as to make the coagulation gradual and
uniform. It was then filtered, the moist tnasa remaining on the filter
snbjected to strong pressure in a linen bag, by a porcelain press,
and the fluid thus obtained added to that previously filtered. The
entire spirituous solution was then evaporated to dryness, the dry
residue extrocted with absolute alcohol, and the alcoholic soltition
trcatcfl as usual, with ether, kc, to discover the proscncc of biliary
mutters. In every instance, blood was taken at the same lime from
the jugular vein, or the alxlominal vena cava, and treated in the
same way for ])urpoae8 of comparison.

We have examined the blood, in this way, one, four, six, nine,
eleven and a half, twelve, and twenty hours after feeding. As the
result of these examinations, we have fuund that in the venous
blood, both of the portal vein iind of the general circulation, there
exists a snb^nce soluble in water and absolute nleoliol, and pre-
cipitflblc by ether from its alcoholic solution. This substance is
often considerably more abundant in the portal blood than in that
taken from the general veuoua system. It adheres closely to the
sides of the gloss after precipitation, so that it is always diflicult,
and often impoiwible, to obtain enough of it, mixed with ether, for
microscopic examination. It dissolves, also, like the biliary sub-
stances, with great readiness in water; but in no instance have we
ever been able to ohtnia from it snch a satisfactory reaction with
PetienUofer'a test, as would indicate the presence of bile. This is
not because the reaction is masked, as might be suspected, by some
of thy other ingredients of the Wood: for if at the same time, two
drops of bile be adde<l to half an ounce of blood taken from the

I
I
I

VARIATIONS AND FUNCTIONS OF BILE. 181

abdominal vena cava, and the two specimens treated alike, the ether-
precipitate may be considerably more abundant in the case of the
portal blood; and yet that from the blood of the vena cavo, dis-
solved in water, will give Pettenkofer'a reaction for bile perfectly,
while that of the portal blood will give no such reaction.

Notwithstanding, then, the irresistible evidence afforded by the
experiments of Bidder and Schmidt, that the biliary matters are
really taken up by the portal blood, we have failed to recognize
them there by Fetteukofer's test. They must accordingly undergo
certain alterations in the intestine, previously to their absorption,
80 that they no longer give the ordinary reaction of the biliary sub-
stances. We cannot say, at present, precisely what these alterations
are ; but they are evidently transformations of a catalytic nature,
produced by the contact of the bile with the intestinal juices.

The bile, therefore, is a secretion which has not yet accomplished
its function when it is discharged from the liver and poured into the
intestine. On the contrary, during its passage through the intestine
it is still in the interior of the body, in contact with glandular sur-
faces, and mingled with various organic substances, the ingredients
of the intestinal fluids, which act upon it as catalytic bodies, and
produce io it new transformations. This may account for the fact
stated above, that the bile, though a constant and uninterrupted
secretion, is nevertheless poured into the intestine in the greatest
abundance immediately afler a hearty meal. This is not because it
is to take any direct part in the digestion of the food; but because
the intestinal fluids, being themselves present at that time in the
greatest abundance, can then act upon and decompose the greatest
quantity of bile. At all events, the biliary ingredients, afler being
altered and transformed in the intestine, as they might be iu the
interior of a glandular organ, re-enter the blood under some new
form, and are carried away by the circulation, to complete their
function in some other part of the body.

162

FORMATIOX 0? SCGAB IS THE LITSS.

CHAPTER IX.

FORMATION OP SUGAR IN THE LIVKR.

Besidb the secretion of bile, the liver performs also ADOtber
exceeiliiiyly important function, viz., the production (/ tiugar by a
metaicKir^ihuiits of some of its orgaiuu ingredieuts.

Under ordioary circumstances a considernble quantity of sac-
charine matter is introduced with tlie food, or produced from
starcliy subsUinces, by ilio digestive process, in the int^»8linal canal.
In man and tbe herbivorous animals, accordingly, an abundant
supply of sugar is derived from these sources; and, ns we Lave
already shown, the sugar thus intro<luced is necessary for the proper
support of the vital functions. For though the sacchnrino matter
absorbed from the intestine is destroyed by decomposition soon
after entering the circulation, yet the chemical changes by wbicH
its deem nposi lion isoQ'cctcd arc themselves necessary for the proper
■constitution of the blood, and the healthy nutrition of the tissues.
Experin\ent shows, however,, that the system does not depend, for
its supply of sugar, entirely upon external sources; but that sac-
charine mutter la also produced independently, in the tissue of the
liver, whatever may bo the nature of the food upon which the
animal subsists.

This important function was 5rat discovered by M. Claude Ber-
nard' in 184d, and described by him under the name of the gluco-
genic/unction of ike liver.

It has long been known that sugar may bo abundantly fiecreted,
under some circumstances, when no vegetable matters have been
taken with the food. The milk, for example, of all animals, car-
nivorous Ds well as herbivorous, contains a notable proportion of
sugar; and the quantity thus secreted, during lactation, is in some
instances very great. In the human subject, also, when suft'cring
from diabetes, the amount of saccharine matter discharged with the

■ Nonrellt) Fonctlon du Folo. I'arli, l$ft3.

FOBMATION OF SUOAB IN THE LITER. 183

Qrine has oftan appeared to be altogether out of proportion to that
which could be accounted for by the vegetable substancefi taken as
food. The experiments of Bernard, the moat important of which
we have repeatedly confirmed, in common with other investigators,
show that in these instances most of the sugar has an internal
origin, and that it first makes its appearance in the tissue of the
liver.

If a camivoroas animal, as, for example, a dog or a cat, be fed
for several days exclusively upon meat, and then killed, the liver
alone of all the internal organs is found to contain sugar among its
other ingredients. For this purpose, a portion of the organ should
be cat into snuiU pieces, reduced to a pulp by grinding in a mortar
with a little water, and the mixture coagulated by boiling with an
excess of sulphate of soda, in order to precipitate the albuminous
and coloring mattera. The filtered fluid will then reduce the oxide
of copper, with great readiness, on the application of Trommer's
test A decoction of the same tissue, mixed with a little yeast, will
also give rise to fermentation, producing alcohol and carbonic acid,
as is usual with saccharine solutions. On the contrary, the tissues
of the spleen, the kidneys, the lungs, the muscles, &c., treated in
the same way, give no indication of sugar, and do not reduce the
salts of copper. Every other organ in the body may be entirely
destitute of sugar, but the liver always contains it in considerable
quantity, provided the animal be healthy. Even the blood of the
portal vein, examined by a similar process, contains no saccharine
element, and yet the tissue of the organ supplied by it shows an
abundance of saccharine ingredients.

It is remarkable for how long a time the liver will continue to
exhibit the presence of sugar, al^r all external supplies of this
substance have been cut off. Bernard kept two dogs under his own
observation, one for a period of three, the other of eight months,'
daring which period they were confined strictly to a diet of animal
food (boiled calves' heads and tripe), and then killed. Upon exa-
mination, the liver was found, in each instance, to contain a propor-
tion of sugar fully equal to that present in the organ under ordinary
circumstances.

The sugar, therefore, which is found in the liver after death, is a
normal ingredient of the hepatic tissue. It is not formed in other
parts of the body, nor absorbed from the intestinal canal, hut takes

> NooTellfl Fonotion du Foie, p. 50.

184 FORMATION OF SCOAB IS THE LIVER.

its origin in the liver ilat-lf; ii is produced, as a new formation,'
by n secreting process in the tiaaue of the organ.

The presence of sugar in the liver is common to all species of
atiiinalfi, so far as is yet known. liernarJ found it invariably in
monkeys, dogs, cats, rabbits, the horse, the ox, the goat, the sheep,
in birdn, in reptiles, and in most kinds offish. It was onl/ in two
apecies of Bah, viz., the eel and the ray (Muru-^na anguilla and Kaia
batis), that he sometimes failed to discover it; but the failure in
these instances was apparently owing to the commencing putres-
cence of the tissue, by which the sugar bad probably boon destroyed.
In the fresh liver of the human subject, examined after death from
accidental violence, sugar wits found to be present in the proportion
of 1.10 to 2.14 per cent, of the entire weight of the organ.

The following list shows the average percentage of sugar present
in the healthy Hvcr of man and different 9|)ccies of animals, accord*
ing to the examinations of Bernard:—

PxnCR-tTAait OP StRAB 15 TItB LtVBI.

In Ttiaii .... I.'GS In ox . . . . 3.30

" m<ink»jr . 2.15 " home .... 4.06

'■ iJvf; . . . 1.3» " goat . . . 3,89

•■ cal . . . . l.H " birds .... 1.49

■' r-ibbil . . . 1.84 " KtpUles . . , 1.04

" Bbei-p . . . 2.00 " lUli . . . . 1.4S

With regard to the nature and properties of the liver sugar, it
resembles very closely glucose, or the sugar of starch, the sugar of
honey, and the sugar of milk, though it is not absoluiely identical
with either one of them. lu solution reduces, as wc have seen, the
salts of copper in Troinmer'a teat, and becomes colored brownwhen
boiled with caustic polassn. It ferments very readily, also, when
mixed with yeast and kejit at tho temperature of 70° to 100' V.
It is distinguished from all the other sugars, according to Bernard,'
by the readirvess with which it becomes decomposed in the blood—
since cane sugar and beet root sugar, if injected into t!ie circulation
of a living animal, pa.<:s through the system without sensible decom-
position, and are discharged unchanged with the urine; sugar of
milk and gJiicnse, if injected in moderate qiiantiiy, are decomposed
in tilt: blood, but if introduced in greater abundance make tbeir
appearance aUo in the urine; while n solution of liver sugar, though
injected In much larger quantity than either of the others, may dia-

( L«qoDB iv Plij'Biologie Ezptjrlcuentale. Paris, 1&S&, p. £13.

FOBHATION OP SUOAB IN THE LIVER. 185

appear altogether in the circulation, without passing ofT by the
kidneys.

This Bobstance is therefore a sugar of animal origin, similar in
its properties to other varieties of saccharine matter, derived from
different soarces.

The sugar of the liver is not produced in the blood by a direct
decomposition of the elements of the circulating 6uid in the vessels
of the organ, but takes its origin in the solid substance of the hepatic
tissue^ as a natural ingredient of its organic texture. The blood
which may be pressed out from a liver recently extracted from the
body, it is trae, contains sugar; but this sugar it has absorbed from
the tissue of the organ in which itcirculates. This is demonstrated
by the singular fact that the fresh liver of a recently killed animal,
though it may be entirely drained of blood and of the sugar which
it contained at the moment of death, will still continue for a certain
time to produce a saGcharine substance. If such a liver be injected
with water by the portal vein, and all the blood contained in its
vessels washed out by the stream, the water which escapes by the
hepatic vein will still be found to contain sugar. M. Bernard has
found' that if all tbesugar contained in a fresh liver be extracted in
this manner by a prolonged watery injection, so that neither the
water which escapes by the hepatic vein, nor the substance of the
liver itself, contain any further traces of sugar, and if the organ be
then laid aside for twenty-four hours, both the tissue of the liver and
the fluid which exudes from it will be found at the end of that time
to have again become highly saccharine. The sugar, therefore, is
evidently not produced in the blood circulating through the liver,
but in the substance of the organ itself. Once having originated
in the hepatic tissue, it is absorbed thence by the blood, and trans-
ported by the circulation, as we shall hereafter show, to other parts
of the body.

The sugar which thus originates in the tissue of the liver, is pro-
duced by a mntual decomposition and transformation of various
other ingredients of the hepatic substance; these chemical changes
being a part of the nutritive process by which the tissue of the
organ is constantly sustained and nourished. There ia probably a
aeries of several dififerent transformations which take place in this
manner, the details of which are not yet known to us. It has been
discovered, however, that one change at least precedes the final

■ Gasette Bebdomxlftins, F&ris, Oct. S, 1855.

FORMATION OF BDOAB IN THE LIVBR.

production of saccharine matter; nnd that the sugar itself is pro-
duced by the trjinsformution of another peculiar substaiiue, of oate-
rior formation. This dtibstance, which precedes the formation of
sugar, and which U itself produced in the tissue of the liver, is fl
known by the name of gli^cogem'c matter, or glyco^cnc.

Thia glycogenic matter may be extracted from the Uvcr tn the
following manner. The organ is taken immediately from the body
of the recently killed animal, cut into small pieceft, and coagulnied by
being placed for a few minutes in boiling water. Thia is in order
to prevent the albuminous liquids of the organ from acting upon
the glycogenic matter and decomposing it at a medium tcraperalure.
The coagulated tissue ia then drained, placed in a mortar, reduced
to a piilp by bruising and grinding, and afterward boiled in dis-
tilled water for a quarter of an hour, by which the glycogenic
matter is extracted and held in solution by the boiling water.

The liquid of decoction, which should be as ooncentrated as pos*
dible, must then be expressed, strained, and filtered, after which it
appears as a strongly opalescent fluid, of u slightly yellowish tinge.
The glycogenic mailer whicli is held in solution may be prceipt- ^
tated by the addition to the filtered fluid of five times its volume H
of alcohol. The precipitate, after being repeatedly washed with '
alcohol in order to remove sugar and biliary matters, may tlien be _
redissolved in distilled water. It may be precipitated from its H
watery solution either by alouhul in excess or by crystal livable
acetid acid, in both of which it ia entirely insoluble, and may be
afterward kept in the dry state for an indefinite time without 1omQ|
its properties.

The glucogenic matter, obtnined in thia way, is regirded
intermediate in it^ nature and properties between liyd rated starch
and dextrine. Its ultimate eompo-sition, according to M. Pclouze,'
is as follows: —

tarchV

When brought into contact with iodine, it produces a coloration
varying from violet to a deep, clear, maroon rod. It does not
reduce the salts of copper in Troramer^s test, nor does it ferment
when placed in contact with yeast at the pro]>er temperature. It ,
does not, therefore, of itself contain sugar. It may easily be con- fl
verted into sngar, however, by contact with any of the animal ^\
ferments, as, for example, those contaiuod in the saliva or in the

■ Jdarnat da Pb/«[i>logts. Vui*, 18S8, p. K2.

FORMATION OF 8U0AE IN THE LIVER.

187

If a solation of glycogenic matter be mixed with fresh
homan aaliva, and kept for a few mlnutea at the temperature of
100° F^ the mixture will then be found to have acquired the power
of reducing the salts of copper and of entering into ferraentation by
contact with yeast. The glycogenio matter has therefore been,
converted into sugar by a proce8S of catalysis, in the same manner
as vegetable starch would be transformed uniJer similar conditions.

The glycogenic mnttcr which is tbus dcatlncd to be converted
into BUgar, is formed in the liver by the processes of nutrition. It
may bo extracted, as we have seen above, from the hepatic tissue
of carntvoroaa animals, and is equally present when lK(;y have been
exclusively confined for many days to a meat diet. It is not in-
troduced with the food ; for the fleshy meat of the herbivora does
not contain it in appreciable qtiantity, though these animals so
constantly take starchy substnnccs with their food. In them, the
starchy matters are transformed into sugar by digestion, and the
sugar 80 produced is rapidly destroyed after entering the circula-
tion; so that usually neither saccharine nor starchy substances arc
to be discovere<J in llio muscular tissue. M. Poggiale' found ihat
in very many experiments, performed by a commission of iho
French Academy for the purpose of examining this subject, glyco-
genic matter was detected in ordinary butcher^s meat only once.
"We have also fouud it to be absent from the fresh meat of the
bullock's heart, when examined in the manner described above.
Nevertheless, in dogs fed exclusively upon this food for eight days,
glycogenic matter may be found in abundance in tho liver, while
it does not exist in other parts of the body, as the spleen, kidney,
lungs, &c.

Furthermore, in a dog fed exclusively for eight days upon the
fresh meat of the bullock's heart, and then killed four hours nfier
a meal of (he same food, at which time intestinal absorption is
going on in full vigor, the liver contains, as above mentioned, both
glycogenic matter and sugar; but neither sugar nor glycogenic mat-
ter can be found in the blood of the portal vein, when subjected to
a similar examination.

The glycogenic matter, accordiugly, does not originate from any
externa] source, but is formed in the tissue of the liver; where it
is s<x>n afterward trnnsformod into sugar, while still forming a pari
of the substance of the orgau.

• Joaninl Ae Ph/siotogle, PaHh, 1S58, jt. US.

Tho formation of suj^nr in tlie liver is ihorofore a function com-
posed of two dletincl and successive processes, viz: first, the forma-
tion, in the hepatic tissue, of a glycogenic matter, having some
resemblance to dextrine; and secondly, the conversion of this
glycogenic matter into sugar, by a process of catalysis and trans-
fprmation.

The sugar thus produced in the substance of the liver is absorbed
from it by the blood circulating in its vessels. The mechanism of
this absorption is probably the same with that which goes on in
other parts of the circulation. It is a process of transudation and
eridodtnosis, by which the blood in the vessels takes up the saccha-
rine flyids of the liver, during its passage through the organ.
While the blootl of the portnl vein, therefore, in an animal fed
exclusively upon meat, contains no sugar, the blood of the hepatic
vein, ns it passes upward to the heart, is always rich, in saccharine
ingredients. This difference can easily be demonstrated by exa-
mining comparatively tbe two kinds of blood, portal and hepatic,
from the recently killed animal. Tho blood in its passage tliroagh
tho liver is found to have acquired a new ingredient, and shows,
upon examination, all the properties of n saccharine liquid.

The sugar produced in the liver is accordingly to be regarded as
11 true secretion, formed by the glandular tissue of the organ, by a
similar process to that of other glandular secretions. It differs
from tho latter, not in the manner of its production, but only in
the raiidff of its discharge. For while the biliary matters pro<luccd
in the liver are absorbed by tlie hepatic ducts and conducted down-
waixl to the gall-bladder and the intestine, the sugar is absorbed by
the bloodvessels of the organ and carried upward, by the hepatic
veins, toward the heart and tho general circulation.

The production of fugar in the liver during health is a constant
process, continuing, in many cases, for several days after the animal
has been altogether deprived of fooil. Its activity, however, like
that of moat othor secretions, is subject to periodical augmentation
and diminution. Under ordinary circumstonces, the sugar, which
is absorbed by the blood from the tiasoe of the liver, disappears
very soon after entering the circulation. As the bile is trunsfomied
in th(j intestine, so the sugar is decomposed in the blood. We are
not yet acquainted, however, with the precise nature of the changes
which it undergoes after entering the vascular system. It is very
probable, according to the views of Lehmann and Kobin, that it is
Bt first converted into lactic acid (C^UgO^), which decomposes in

FORUATIOy OF SUOAB IK THE LIVER. 189

turn the alkaline carbonates, setting free carbonic acid, and forming
lactates of soda and potassa. But whatever be the exact mode of
ita transformation, it is certain that the sugar disappears rapidly;
and while it exists in considerable quantity in the liver and in the
blood of the hepatic veins and the right side of the heart, it is nut
usually to be found in the pulmonary veins nor in the blood of the
general circulation.

About two and a half or three hours, however, after the ingestion
of food, according to the investigations of Bernard, the circulation
of blood through the portal system and the liver becomes consider-
ably accelerated. A larger quantity of sugar is then produced in
the liver and carried away from the organ by the hepatic veins;
80 tbat a portion of it then escapes decomposition while passing
through the lungs, and begins to appear in the blood of the arterial
system. Soon aflerward it appears also in the blood of the capil-
laries; and from four to six hours afler the commencement of
digestion it is produced in the liver so much more rapidly ihan it
is 4estroyed in the blood, that the surplus quantity circulates
throughout the body, and the blood everywhere has a slightly sac-
charine character. It does not, however, in the healthy condition,
make its appearance in any of the secretions.

After the sixth hour, this unusual activity of the sugar-producing
foDCtion begins again to diminish ; and, the transformation of the
sugar in the circulation going on as before, it gradually disappears
as an ingredient of the blood. Finally, the ordinary equilibrium
between its production and its decomposition is re-established, and
it can no longer be found except in the liver and in that part of
the circulatory system which is between the liver and the lungs.
There is, therefore, a periodical increase in the amount of unde-
cotnposed sugar in the blood, as we have already shown to be the
fCase with the fatty matter absorbed during digestion; but this
increase is soon followed by a corresponding diminution, and daring
the greater portion of the time its decomposition keeps pace with
its production, and it is consequently prevented from appearing in
the blood of the general circulation.

There are produced, accordingly, in the liver, two different secre-
tioDB, viz., bile and sugar. Both of them originate by transforma-
tion of the ingredients of the hepatic tissue, from which they are
absorbed by two difl'erent sets of vessels. The bile is taken up by
the biliary ducts, and by them discharged into the intestine; while
the sugar is carried off by the hepatic veins, to be decomposed in the
circulation, and become subservient to the nutrition of the blood.

Tns 8PtEBX.

CHAPTER X,

THE SPLEEN

Thb spleen is en exceedingly vascular organ, situated in the
vicinity of the great pouch of" ilic stumncb ami supplieil abund-
antly by branches of the caeliac axis, lis veins, like ihate of the
digestive abdominal organs, form a part of the great portal system,
and conduct the blood which has passed through it to the liver,
before it mingles again with the general current of the circulation.

The spleen is covered on its exterior by an investing membrane
or capsule, which forms a protective sac, containing the soft pulp
of which the greater part of the organ is composed. This capsule,
in the spleen of the ox, is thick, whitish, and opaque, and is com-
posed to a great extent of yellow elaatio tissue. It accordingly
possesses, in a high degree, ihc physical properly of elasticity, and
may be widely stretched without laceration; returning readily to^
its original size ns soon as the extending force is relaxed. fl

In the carnivorous animals, on the other hand, the capsule of
the spleen is thinner, and more colorless and transparent. It coo-
tains here but very little elastic tissue, being composed mostly of
amooth, involuntary muscular fibres, connected In layers by a little
intervening areolar tissue. In ihft herbivorons animals, accordingly,
the capsule of the spleen is simply elastic, while in the carnivoni it
is contractile. M

In both instances, however, the elastic and contractile properties
of the capsule subserve u nearly similar purpose. There is every
reason to believe that the spleen is subject to occasional and per-
haps regular variations in sItic, owing to the varying condition of
the abdominal circulation. Dr. William Dobson' found that the
BlKe of the organ increased, from the third hour arier feeding up to
the llfih; when it arrived at its maximum, gradually decreasing
after that period. When these periodical congestions take placOi

* In Gnj, on the Stmatan* and Use* ot tliA 5plc«n. London, 18M, p. 40.

TDK SPLEEK.

191

tbe orgnn bccomiDg torgid with blood, the capaule is distended ;
nnd limits, by its resisting power, the degree of tumefaciion to
which the spleen is liable. When the disturbing cause has again
passed away, and tbe circulation is about to return to its ordinary
condition, the elasticity of the capsule in tbe herbivora, ntid its con-
tractility in the carnivora, compress the soft vascular tissue within,
and reduce the organ to its original dimensions. This contractile
action of the investing capsule can be readily ^een in the dog or
the cut, by opening tbe abdomen while digetttiou is going on, ex-
posing the spleen and removing it, afler ligature of its veasels.
When Grst exposed, the organ is plump and rounded, and presents
externally a smooth and shining surface. But as soon as it has
been removed from the abdomen and its vessels divided, it begins
to ountraet sensibly, becomes reduced in size, stifl', and resisting to
the touch; while its surface, at the same time, becomes uniformly
wrinkled, by the contraction of its muscular Rhnrs.

In its interior, the substance of the spleen is traversed everywhere
by slender and ribbondike cords of fibrous tissue, which radiate
from the sheath of its principal arterial trunks, and lire finnlly
attached to the internal surface of its investing cnpsnlc. These
Sbrous cords, or traUculoe, as they are called, by their frequent
branching and mutual interlacement, form a kind of skeleton or
fratnework by which the soU splenic pulp is embraced, and the
shape and integrity of the organ maintained. They are composed
of similar elements to those of tht; investing capsule, viz., elastic
tissue and involuntary nuiacular fibres, nniicd with each other by
a varying quantity of the fibres of areolar tissue.

The interstices between the trabeculte of the spleen are occupied
by the splenic pulp; a soft, reddish substance, which contains,
beside a few nerves and lymphaiirs, capillary bloodvessels in great
profusion, and certain whitish globular bodies, which may be re>
garded us the distinguishing anatomical elt^niuuts of the organ, and
which are termed the Malpiyhmn bodies of ihe apleen.

Tbe Malpighian bodies are very abundant, and are scattered
tbroaghout the splenic pulp, being most frequently aitached to the
sides, or at tbe point of bifurcation of some small artery. They
■re readily visible to the naked eye in the spleen of the ox, upon a
fresh section of tbe organ, as minute, whitish, rounded bodieit. which
mav be separated, by careful manipulation, from tbe surrounding
parts. In the carnivorous animals, on the other hand, and in the
human subjeet, it is more difTici'It to distinguish them by the an*

192

THE SPLEEN,

aided eye, though they always exist in the spleen in a healthy
condition. Their average diameter, according to Kollikcr, is ,'5 of
an inch. They consist of a closed sac, or capsule, containing in
its interior a viscid, semi-solid mass of cell!!, cell-nuclei, and homo-
gencous Kubstnncc. Each Malpigliiau body is covered, on its exte-
rior, by a network of fine capillary bloodvessels; and it is now
perfectly well settled, by the observations of various anatomists
(Kultiker, Busk, Huxley, kc), that blooilvesseU also penetrate into
the substance of the Malpighian body, and there form on interaal
capillary plexus.

The spleen is accordingly a glandular organ, analogous in its
minute structure to the solitary nnd agmlnated glands of the mmall
intestine, and to the lymphatic glnnds throughout the body. Like
them, it is a gland without an excretory duct; and resembles, also,
in this respect, the thyroid and thymus glands and the suprarenal
capsules. All these organs hnve a structure which is evidently
glandular in its nature, and yet the name of glands has been some-
times refused to them because they have, as above menuoned, nn
duct, and produce apparently no distinct secretion. We have
already seen, however, that a secretion may bo produced in the
interior of a glandular organ, like the sugar in the substance of the
liver, and yet not be discharged by its excretory duct The veins
of the gland, in this instance, perform t1ie part of excretory ducts.
They absorb the new materials, and convey them, through the
medium of the blood, to other parts of the body, where they suffer
subsequent alterations, and are fiually decomposed in the circula-
tion.

The action of such organs is consequently to modify- the consti-
tution ol' the blood. As the blood pnsscij through their tissue, it
absorbs from the glandular substance certain materials which it did
not previously contain, and which are necessary to the perfect con-
stitution of the circulating fluid. The blood, as it paiwes out from
the organ, has therelbre a diflerent composition from that which it
possessed before its entrance; and on this account the name of vaa-
cuiar gfands has been applied to all the glandular organs above
mentioned, which are destitute of excretory ducts, and is eminently
applicable to the spleen.

The precise alteration, however, which is effected in the blood
during its passngc through the splenic tissue, has not yet been
discovered. Various hypotheses have been advanced from time to
time, as to the processes which go on in this organ; many of them

THB SPLKRS.

103

vague aod inde6nite in cbaracter, and some of tbem directly con-
tradictory of each other. None, however, have yet been oflcred
which are eotirely satiafactor^' iti themselves, or which rest on suf-
ficiently reliable evidence.

A very remarkable fact vrith regard to the spleea is that it may
be eutircly removed in many of the lower animals, without iia lona
producing any serious permanent injury. This experiment has
been frequently performed by various observers, and we have our-
selves repeated it several times with similar results. The organ
niay be easily removed, in the dog or the cat, by drawing it out of
the abdomen, through an opening in the mediun line, placing a few
ligatures upon the vessels of the gastro-splonic omentum, and then
dividing the vessels between the ligatures and the spleen. TLie
wound usually heals without dilEcuIty; and if the animal be killed
some weeks al^rward, the only remaining trace of the operation
ia an adhesion of the omentum to the inner surface of tlie abdomi-
nal parietes, at the situation of the original wound.

The most constant and permanent effect of a removal of the
spleen is an unusual increase of the appetite. This symptom we
have obser^'ed in some instances to bo excessively developed; so
that the animal would at all times throw himself, with an unnatural
avidity, upon any kind of food offered him. We have seen a dog,
subjected to this operation, afterward feed without hesitation upon
the fiesh of other dogs; and even devour greedily the entrails, taken
warm from the abdomen of the recently killetl animal. The food
taken in this unusual quantity is, however, perfectly well digested;
and the animal will often gain very perceptibly in weight. In one
instance, a cat, in whom the unnatural appetite was marked though
nut excessive, increased in weight from five to six pounds, iu the
course of a little less than two months; and at the same time the
fur became sleek and glossy, and there was a considerable improve*
roent iu the general appearance of the animal.

Another symptom, which usually follows removal of the spleen,
is an unnatural ferocity of disposition. The animal will frequently
attack others, of its own or a different species, without any appa-
rent cause, and without any regard to the diflerence of size, strength,
&c. This symptom is sometimes equally exuessive with that of an
unoataral appetite; while in other instances it shows itself only in
(xscasional outbursts of irritability and violence.

I^eitber of the symptoms, however, which we have just de*
acinbed, appears to exert any permanently injurious effect upon the
IS

THE aPLEEX,

Bnitnal which bus been subjected to the operation; ami life raay be
prolonged for an indeflnitc period, without nny serious disturbance
of tlio nutritive process, afXcr tbe spleen baa been completely
extirpated.

We must accordingly regard t*he spleen, not as a eingle organ,
but as associated with others, which may completely, or to a great
extent, perform its functions after its entire removal. Wo have
already noticed the similarity in struuture between tlie spleen and
the mesenteric and lymphatic glands; a similarity which boa led
some writers to regard them as more or leas closely nssociatetl with
each other in function, and to consider the spleen as an unusually
developed lymphatic or mesenteric glaod. It is true that this
organ is provided with a comparatively scanty supply of lymphatic
veasela; and the chyle, which is absorbed from the intestine, does
not pass through the spleen, us it posses through the remaining
mesenteric glands. Still, tbe physiological action of the spleen
may correspond with that of tbe other lymphatic glands, so far as
regards its influence on the bluod; and there can be little doubt
that its function is shared, cither by them or by some other glan-
dular organs, which become unnaturally active, and more or less
perfectly supply its place afWr its complete removal.

BLOOD-OLOfiULES. 105

CHAPTER XI.

THE BLOOD.

Ths blood, as it exists in its Dstural condition, while circulating
in the vessels, is a thick opaque flaic], varjiog in color in different
parta of the body from a brilliant scarlet to a dark purple. It has
a slightly alkaline reaction, and a specific gravity of 1055. It
is not, however, an entirely homogeneous fluid, but is found on
micnMCopic examination to consist, first, of a nearly colorless,
transparent, alkaline fluid, termed the plasma, containing water,
fibrin, albumen, salts, &c., in a state of mutual solution; and,
secondly, of a large number of distinct cells, or corpuscles, the
blood-globules, swimming freely in the liquid plasma. These glo-
bnles, which are so small as not to be distinguished by the naked
eye, by being mixed thus abundantly with the fluid plasma, give
to the entire mass of the blood an opaque appearance and a uniform
red color.

Blood-globules. — On microscopic examination it is found that
the globules of the blood are of two kinds, viz., red and white; of
these the red are by far the most abundant.

The red globules of the blood present, under the microscope, a
perfectly circular outline and a smooth exterior. (Fig. 54.) Their
size varies somewhat, in human blood, even in the same specimen.
The greater number of them have a transvorse diameter of ^^'^p of
an inch; but there are many smaller ones to be seen, which are
not more than j^'^j or even ^^^j^ of an inch in diameter. Their
form is that of a spheroid, very much flattened on its opposite
surfaces, somewhat like a round biscuit, or a thick piece of money
with rounded edges. The blood-globule accordingly, when seen
Satwise, presents a comparatively broad surface and a circular out-
liDe(a); but if it be made to roll over, it will present itself edge-
vise during its rotation and assume the flattened form indicated at
ft. The thickness of the globule, seen in this position, is about

THB BLOOD.

Pig. &4.

Tiivv o^ )>° ioch, or a little less than o»o-fl(lh of ita transverso
diameter.

When the globules nre examined lying upon their broad sur-
faces, it can be seen that these aurfaces are not exactly flat, but that

there lii on each side a slight
central depression, so tliat
tho rounded edges of the
blood-globule are evidently
thtuker than its middle por-
tion. Thia inecpinlily pru-
ducca a remarkable optical
effect. The substance of
which the blood-globula is
composed refracts light more
strongly than the flnid plaa-
Dia. Therefore, when exn-
mined with the microecope,
by transmitted light, the
thick edges of the globules
act US double convex lenses,
and concentrate the light
above the level of the flnid. Consequently, if the object-glass be
carried upward by the adjusting screw of the microscope, and lifted

away from the stage, so that

*^/

@ ©

Fig. fiS.

••)

tlie blood -globules fall be-
yond its focus, their et^lges
will appear brighter. But
the central portion of each
globule, being excavated on
both sides, acts as a double
concave lens, and disperses
the light from a point below
the level of the fluid. It,
therefore, grows brighter as
the object-glass is carried
downward, and the object
falls within its focus. An
alternating appearance of the
blood-glob ule3 may, there-
fore, be produced by view-
ing them first beyond and then within the focus of the instrument.

twjrouil tliv Tneui of Ihr iiiltfFiiii-iiiM

lltlli<

BLOOD-OLOBULZa.

197

TmiAHK, iwD > lUtle wllbln the foenii.

When bejood the focaa,-the globules will be seen with a bn'gbt
rim and a dark centre. (Fig. 55.) When within it they will appear
with a dark rim and a bright
oent«». (Fig. 66.) "8- ««•

The blood-globales accord-
ingly hare the form, of a
thickened diak with rounded
edges and a doable central
excavatioD. They have, con-
sequently, been sometimea
called "blood-disks," instead
of blood-globulee. The term
"disk," however, does not in-
dicate their exact shape, any
more than the other; and
the term "blood-corpuscle,"
which is also sometimes used,
does not indicate it at all.
And altbongh the term "blood -globule" may not be precisely a
correct one, still it is the most convenient; end need not give rise
to any confusion, if we remember the real shape of the bodies de-
rignated by it This term will, consequently, be employed when-
ever we have occasion to
speak of the blood-globules vig. S7.

in the following pages.
Within a minute alVer being
placed under the microscope,
the blood-globules, after a
flactaating movement of
abort duration, very often
airaoge themselves in slight-
ly curved rows or chains, in
which they adhere to each
other by their flat surfaces,
presenting an appearance
which has been aptly com-
pared with that of rolls of
coin. This is probably ow-
ing merely to the coagulation

of the blood, which takes place very rapidly when it is spread nut
in thin layers and in contact with glass surfaces; and which, by

BLODD'aLOBDLii >dberlD( logalbar, liks rolli
of coin.

THB HLOOD.

compressing tlie globules, fi>rces them into such a position that they
may occupy the least possible space. This position is cvidcntlj
that in which ihey are ap^jlied to each other by their flat surfs
as above described.

The color of ihe bloixl- globules, when viewed by traosmil
light and spread out in a thin Inyer, is a light amber or pale yellow.
It ia, on the contrary, deep red when they are seen by reflected
light, or piled together Jn eomparativeJy thick layers. When viewed
singly, they are so transparent that the oullinesof those lying under-
neath can be easily seen, showing through the substance of the
superjacent globules. Their consistency is peculiar. They are not
solid bodies, ns they have been sometimes inadvertently described;
but on ttie contrary have a consistency which is very nearly fluid.
They are in consequence exceedingly flexible, and easily elongated,
bent, or otherwis« disioried by accidcnia! pressure, or in passing
through the narrow currents of fluid which often establish them-
selves accideatally in a drop of blood under microscopic examina-
tion. This distortioD, however, is oidy temporary, and the globules
regain their original shape, as soon as the accidental pressure is
taken off. The peculiar flexibility and elasticity thus noticed are
characteristic of the red globules of the blood, and may always
serve to distinguish thorn from any other free cells which may bo
found in the animal tissues or fluids.

In structure the blood-globuIc.-? are homogeneous. They have
been sometimes erroneously described as consisting of a closed
vesicle or cell-wall, containing in its cavity some fluid or semi-fluid
substance of a different character from that composing the wall of
the vesicle itself. No such structure, however, is really to be seen
in them. Kach blood-^dobule consists of a mass of organized uoi-
lual substance, perfectly or nearly homogeneous in appearance, and
of the aaino color, consistency and composition throughout. In
some of the lower animals (birds, reptiles, fish) it contains also a
granular nucleus, imbedded in the substance of the globule; but
in no instance is there any distinction to be made out between an
external cell-wall and an internal cavity.

The appearance of the blood -globules is altered by the addition
of various foreign substances. If water be addedf so as to dilute
the plasma, the globules absorb it by imbibition, swell, lose their
double central concavity and become paler. If a larger quantity
of water be added, they finally dissolve and disappear altogether.
When a moderate quantity of water is mixed with the blood, the

BLOOD-OLOBULES.

109

Pig. 68.

Bloop-o bOBDLEi, iwulleu bj the tmblblrloa of

wftter.

edges of the globules, being thicker than the central portionB, and
absorbing water more abundantly, become turgid, and encroach
gradually upon the central
part. (Fig. 58.) It is very
common to see the central
d^ression, under these cir-
cumstances, disappear on one
Bide before it ia lost on the
other, so that the globule, as
it swells up, curls over to-
wards one side, and assumes
a peculiar cup-shaped form
(a). This form may oflen be
seen in blood-globules that
have been soaking for some
time in the urine, or in any
other animal fluid of a less
density than the plasma of
the blood. Dilute acetic acid

dissolves the blood-globules more promptly than water, and solu-
tions of the caustic alkalies more promptly still.

If a drop of blood be allowed partially to evaporate while unaer
the microscope, the globules
near the edges of the prepa-
ration often diminish in size,
and at the same time present
a shrunken and crenated ap-
pearance, as if minute gran-
nies were projecting from
their surfaces (Fig. 59); an
effect apparently produced
by the evaporation of part
of their watery ingredients.
For some unexplained rea-
aon, however, a similar dis-
tortion is often produced in
some of the globules by the
addition of certain other ani-
mal fluids, as for example the
saliva; and a few can even
addition of pure water.

Blood-olobulki, ihrDakeD, wtlh Ihelrmarglas
crsDkled.

be seen in this condition after the

200

THB BLOOD.

The entire mass of the blood globules, in proportion to the rest
of the circulating fluid^ can only be approximately measured by
the eye in a microscupiu examination. In ordinary analyses the
globules are usually estimated as amounting to about flflcen per
cent., by weight, of the entire blood. This estimate, however, refers,
properly speaking, not to the globules themselves, but only to their
dry residue, aflor the water which they contain haa been lost by
evaporation. It is easily seen, by examination with the microscope,
that the globules, in their natural KOmi-fluid condition, are really
much more abundant than this, and constitute fuUy one^ai/" the
entire maatof ihe hlooil; that is, the intercellular fluid, or plasma, is
not more abundant than the globules themselves which are sua*
pendcd in it. When separated from the other ingredicnta of tho
blood and examinetl by themselves, the globules are found, oo
cording to Lehmaun, to present the following componilion : —

03MPt)BtT[0K OP THE Bl,Oor>-OuteDLBa 1:1 l<kt(> PAKTS.

Wdtfrr «B8.00

Ulotmlliia 283.22^

H^-iaitCin«

Fally EubfiUiicea

Unrtplcrmincil (<-x(rAct)r«) maltera

Chloride of sndiuiii . .

** potnxaiuni

Ptiii>phBt«s of Bod& >uil i>ol&»ia
Sal|.liiit« " "

I'lm^pliAio or \\m« . ( .
" uifljio«ala

1S.7S,;
2.31

8.1a

iiK<u.m>

The most important of these ingredients is the ^hhuline. This
is an organic substance, nearly fluid in its natural condition by
union with water, and constituting the greater part of the mass of ■
the blood-globules. It is aolublc in water, but insoluble in the
plasma of the blood, owing to the presence in that fluid of albumen
and aaline matters. If the blood be largely diluted, however, the I
gtobuline la dissolved, as already mentioned, and the blood globules
are destroyed, tilobuline coagulates by heat; but, according to
Robin and Verdeil, only becomes opalescent at liiQ°, and requires
for its complete coagulation a temperature of 200° F. M

The Ii(vmaUne i» the coloring matter of the globules. It is, like ^
globuline, an organic substance, but is present in much smallerquari-
tity than the latter. It ia not contained in the form of a powder,

BLOODQLOBULSS. 201

mechanically deposited in the globaline, but the two substances are
intimately mingled throughout the mass of the blood-globule, just
as the fibrin and albumen are mingled in the plasma. Hjematine
contains, like the other coloring matters, a small proportion of iroQ.
This iron has been supposed to exist*under the form of an oxide;
and to contribute directly in this way to the red color of the sub-
stance in question. But it is now ascertained that although the
iron 18 found in an oxidized form in the ashes of the blood-gobules
afler they have been destroyed by heat, its oxidation probably takes
place during the process of incineration. So far as we know, there-
fore, the iron exists originally in the hsematiae as an ultimate
element, directly combined with the other ingredients of this sub-
stance, in the same manner as the carbon, the hydrogen, or the
nitrogen.

The blood-globules of all the warm blooded quadrupeds, with
the exception of the family of the camelide, resemble those of the
human species in shape and structure. They differ, however, some-
what in size, being usually rather smaller than in man. There are
bat two species in which they are known to be larger than in man,
viz., the Indian elephant, in which they are ^^w °^ ^n inch, and
the two-toed sloth (Bradypus didactylus), in which they are y^n of
an inch in diameter. In the musk deer of Java they are smaller
than in any other known species, measuring rather less than j^izv
of an inch. The following is a list showing the size of the red
globules of the blood in the principal mammalian species, taken
from the measurement of Mr. Gulliver.'

DlAHSTES OF

Bbd Olobdlbs in thi

Ape

• si'ffi.of

KU iDch.

Cat

- • »%•'

an inch

Hone .

nVff

Fox .

Tl'dO

lAlf

Wolf .

jAit

Sheep.

15'af

Elephant

iVo»

Qoat .

Bs'lIB

Red deer

in'ffff

Dog . .

5i'o 0

Husk deer

• Lthvv

In all these instances the form and general appearance of the
globules are the same. The only exception to this rule among the
mammalians is in the family of the camelidse (camel, dromedary,
lama), in which the globules present an oval outline instead of a
circular one. In other respects they resemble the foregoing.

Id the three remaining classes of vertebrate animals, viz., birds,

> Id Works of William Uewson, Sydenham edition, London, 1846, p. 327.

202

THE BLOOD.

reptiles and finh, the blood-globutey tlifler so mucli from the above
that they can be rend'ily distinguished by microscopic examination.
They are oval in fonn, urid contain a colorless granular nucleus
imbedded,- In their substance. They are also considerably larger
than the blood -globules of the maminalians, particularly iu the .

cla.s3 or reptiles. In the frog
Fig. 60. (Fig. 60) they measure Ta'oo

of an inch in their long
diameter ; and In J/«i'^m*i- _
ehita, the great water lizard |
of the northern lakes, ^J« of
an inch. Id Proteus anffui-
nvs they attain the size, ac-
cording to Dr. CarpeDter,' of
jjf of an inch.

Beside the corpuscles de-
scribed above, there arc glo-
bules of another kind found
in the blood, viz., the white
globules. These globulea are
very much less Domeroua
than thu red ; the proportioa
Iwtwccn the two, in human blood, being one white to two or three
hundred red globules. In reptiles, the relative quantity of the
white globulea is greater, but they arc always considerably less
abundant than the red. They difl'er also from the latter in shap^
size, color, and consialoncy. They arc globular in form, whilo or
colorless, and instead of being homogeneous like the others, their
Buhstanoe is filled everywhere with minute dark molecules, which
give them a finely grnnukr appearance. (Fig. 54, c.) In size they
are considerably larger than the red glubutes, being about gg'oo of
an inch in diameter. Tliey are also more couRistcnt than the others, _
and do not so easily glide along in the minute currents of a drop of |
blood under examination, but adhere readily to the surfaces of the
glass. If treated with dilute acetic acid, they swell up and become
smooth and circular in outlino; and at the same time a separation
or partial congnlation seems to take place in the substance of wbtch
they are composed, so that an irregular collection of granular
matter shows itself in their interior, becoming more divided and

BLuoD-aLoacLt* itr T*cn.
■MB adgBwUB- l. Wlili*-|l»Uiilii.

Blood lloltnl*

' Tht UEoroioopv »nd iu Burvlntiom, Fhlladvlpliin ediliOD, p. OOO.

BLOOD-OLOBULSS.

208

brokea ap as the action of the acetio acid upon the globule is
longer continued. (Fig. 61.) This collection of granular matter
often assumes a curved or crescentic form, as at a, and sometimes
various other irregular shapes. It does not indicate the existence
of a nucleus in the white globule, but it is merely an appearance
produced by the coagulating
and disintegrating action of ^ig- ^^-

aceticacid upon the substance
of which it is composed.

The chemical constitution
of the white globules, as
distinguished from the red,
has never been determined;
owing to the small quantity
in which they occur, and the
difficulty of separating tbcm
fhim the others for purposes
of analysis.

The two kinds of blood-
globalea, white and red, are
to be regarded as distinct
and independent anatomical

fonuB. It has been sometimes supposed that the white globules
were converted, by a gradual transformation, into the red. There
ia, hovever, no direct evidence of this; as the transfurmation has
never been seen to take place, either in the human subject or in
the mammalia, nor even its intermediate stages satisfactorily ob-
served. When, therefore, in default of any such direct evidence,
we are reduced to the surmise which has been adopted by some
lathois, viz., that the change " takes place too rapidly to be de-
lected by our means of observation,'" it must be acknowledged
tbat the above opinion has no solid foundation. It has been stated
by some authors (Kdltiker, Gerlach) that in the blood of the
bitracbian reptiles there are to be seen certain bodies intermediate
in appearance between the white and the red globules, and which
represent different stages of transition from one form to the other;
bat this is not a fact which is generally acknowledged. We have
repeatedly examined, with reference to this point, the fresh blood
of the frog, as well as that of the menobranchus, in which the large

Wbiti OkOiDLMa op tBB Blood; ftltend hj
dilate iMtle kcld.

K5Ulker, Handbnch der Oewebelehre, Leipzig, 1852, p. 582.

204

THE BLOOD.

size of the globules would give every opportunity for detecting nny
such changes, did they really exist; and it is cor unavoidable con-
clusion from these observations, that there is no good evidence, evea
in the blood of reptiles, of any sucli transfonnatioti taking place.
There is simply, as in human blood, a certain variation in sise and
opacity among the red globules; bat no such connection with, or
resemhlaiice to, the white globules as to indicate a passage from one
form to the other. The red and white globules are therefore to be
regarded as distinct nnd independent anatomical elements. They
are mingled together in the blood, just as capillary bloodvessels and
nervesare mingled in areolar tissue; but there is noother connection
between them, so far aa their formation is oonceraed, than that of
Juxtaposition.

Neither in it at all probable that tho red globules are produced or
destroyed in any particular part of the body. One ground for the
belief that these bodies were produced by a metamorphosis uf the
white globules was a supposition that they were uontinually and
rapidly destroyed somewhere in tho circuktion; end as this loss
roost be aa rapidly counterbalanced by the formation of new glo-
bules, and as no other probable source of their reproduction ap-
peared, they were supposed to be produced by transformation of
the white globules. But there is no reason for believing that the
red globules of the blood are any less permanent, as anatomical
forms, than the muscular fibres or the ncrvoos filaments. They
undergo, it is true, like all the coastituent parts of the body, a
constant interstitial metamorphosis. They absorb incessantly nu-
tritions materials from the blood, and give up to the circulating
fluid, at the same time, other substances which result from their
internal waste and disintegration. But they do not, so far as we
know, perish bodily in any part of the circulation. It is not the
ajuitomical forms, &ay where, which undergo destruction and reno-
vation in tho nutritive process; but only tki proximate principlea of
rchieh theij are composed. The effect of this Interstitial nutrition,
therefore, in the blood -globules as in the various solid tissues, is
merely to maintain them iu a natural and healthy uonditioa of
integrity. Their ingredients are incessantly altered, by transforma-
tion and decomposition, as they pass through various parta of tb«
vascular system; but the globules themselvea retain their form
and texture, and still remain as constituent })arts of the circulaiiog
fluid.

I
I

PLASMA.

206

6.55

Plasma. — *V\iepJ<uma of the blood, according to Lehmann, haa
l!fae foUowiog constitution:^

CoMmM-nox or trb Plahxa nr 1,00(1 paxt*.

W»l*r &03.M

Fibrin 406

Aibanwn 76.84

mtjr nuiura 1.72

tTndotMiniiMd (vxtravtlre) matters 3.M

Clilorldu of e'^liain

" potaBsluni ....

PhoaphKtM of imJa itnil potMU .
Solphatmi " "...

Pb(wpb*le of lime

** nsgneilK ....

lOOO.OO

The above tngredienU are all intimately mingled in Uie blood-
plasma, in a flaid form, by mutual solution; but they may be scpa-
rated from each other for examination by appropriate means. The
two iogretlients belonging to the class of organic subataoces are the
fibrin and the albumen.

The jlbn'n, though present in small quantity, is evidently an im-
]tartant element in the constitution of the blood. It may be ob-
tained in R tolerably pure form by gently stirring freshly drawn
Wood with A glft*s rod or a bundle of twigs; upon which the fibrin
coagulates^ and adheres to the twigs in the form of slender threads
and flakes. The fibrin, lliuscongulated, is at lirst colored red by
the haimatine of the bloo<l -globules entangled in it; but it may be
vasheU colorless by a few hours' aonking in running water. The
fibrin iheu presents itself

under the form of nearly
white threads and Hakes,
luviog a semi-solid consist-
eocy, and a oonsider&ble de<
groe of elasticity.

The oo&gulatioD of ftbrin
lakes place in a peculiar
■nanner. It does not solidify
ia a perfectly bomogeneous
max; but ifcxamincd by the
microiscope in thin layers it
M seen to have a fibroid or
filamentous texture. In this
condition it is said to be
''fibrillat«d."(Fig.62.) The

IN5. 62.

Co*aitt.ATIDriaBllc,«b<)'«lBBlliat'rtnftl(r«iran.
d I lino.

filaments of wliich it is compaiiefl nre colorless and elastic, anrl when
isolated are seen to be exceedingly minote, being not more than
loltTB or even soSitd of an inch in diameter. They are in part
arranged so as to lie parallel with each other; but are mora gene-
rally interlaced in a kind of irregular network, crossing each other
in every direction. On the addition of dilute acetic acid, they swell
up and fuse together toto a homogeneous mass, but do not dissolve.
They are often interspersed evtry where with minute granular mole-
cules, which render their outlines more or less obscure.

Once coagulated, 6brin is insoluble in water and can only be
again liquefied by the action of an alkaline or atrongly saline solu-
tion, or by prolonged boiliog at a very high temperature. These
agents, however, produce a complete alteration in the properties of
the Hbrin, and af\er being subjected to them it is no longer the
same substance as before.

The quantity of fibrin in the blood varies in different parts of the
body. According to tho observations of various writers,' there is ■
more fibrin generally in arterial than in venous blood. The blood
of the veins near the heart, again, contains a smaller proportion of
6brin than those at a distance. The blood of the portal vein con-
tains less than that of the jugular; and that of the hepatic vein less
than that of tho purUil.

The albumen is undoubtedly the most important ingredient of the
plasma, judging both from its nature and the abundance in which
it occurs. It congulates at once on being heated to 1U0° F., or by
contact with alcohol, the mineral acids, the metallic salts, or with
ferrocyanide of potassium in an acidulated solution. It exists natu*
rally in the plasma in a fluid furm by reason of its union with
water. The greater part of the water of the jjlasma^ in fact, is in
union with the albumen; and wheu the albumen coagulates, the
water remains united with it, and assumes at the same time the
solid form. If the plasma of the blood, tliereforc, after tho removal
of the fibrin, be exposed to the temperature of 160* F., it solidifies
almost completely ; so that only a few drops of water remain that
can be drained away from the coagulated mass. The phosphates
of lime and magnesia are also held in solution principally by the
alliumcn, and are retained by it in coagulation.

The /any matters exist in the blood mostly in a saponified form,
excepting soon afler the digestion of food rich in fat. At that
period, as we have already mentioned, the emulsioned fat finds ita

' Rftbin nnrt Verdell, op. dt., vftl. II. p. 208.

COAOPLATION OP THE BLOOD.

207

way into the btooJ, and circulates for a time unchanged, Aftar-
ward it disappears as free fat, and rcmaina partly in the saponified
ooodition.

The aaline ingredients of the plaema arc of the same nature with
those existing in the globules. The chlorides of sodium and [kjIas-
siitcn, and the phospbatuts uf suda and putassa are the most abundant
in both, while the sulphates are present only in minute quantity.
The proportions in which the various salts are present are very dif-
ferent, according to Lchmann,' in the blood-globules and in the
plasma. Chloride of potassium is most abundant in the globules,
chloride of sodium ia the plasma. The phosphates of soda and
potassa are more abundant in the globuks than in tlic plasma. On
the other band, the phosphntes of lime and magnesia are more
Abundant in the plasma than in the globule.4.

The substances known under the name of extraciive malters consist
of a mixture of diftereni ingredients, belonging mostly to the class
of organic substances, which have not yet been separated in a state
of suHicienl purity to admit of their being thoroughly examiued
and distiuguisbed from each other. They do not exist in great
ubandance, but are undoubtedly uf conisiderable importanuu in the
constitution of the blood. Beside the substancen enumerated in the
above list, there are stilt others which occur in small quantity as
ingredients of the blood. Among the most important are t1i<3 alka-
line carbonales, which are held in solution in the serum. It has
ttrcady been inenttoned that while the plin^phatCB are must abun-
dant in the blood of the cnrnivora, the carbona;,cs are most abun-
dant in that of the herbivora Thus liChmann* found carbonate of
soda iu the blood of the ox in the proijorlion of 1.628 per thousand
ports. There are also to be found, in solution in the blood, urea,
urate of soda, creatine, cr&Uinine, sugar, &c.; all of them cryatalli&a-
Mc aabstancea derived from the transformation of other ingredients
of the blood, or of tlie tissues through which it circulates. The
relative quantity, however, uf thette substances ia very minute, and
bas not yet been determined with precision.

Coagulation of the Blood. — A few moments after the blood
!uis been withdrawn from the vessels, a remarkable phenomenon
presents itself, viz., its coagulation or clotting. This process com-
raenoes at nearly the same time throughout the whole mass of the
Wood. The Wood becomes first somewhat diminished in fluidity,

Op. dt.. vol. i. p. S46.

• Op. olt., Tol. \. p. 393.

SOS

THE BLOOD.

SO that it will not run over the edge of the vessel, wbeo slightly
inclined; and Its surface may be genily depressed with the end of
the finger or a glass rod. It then becomes rapidly thicker, and at
last solidiBea into a uniformly red, opaque, consistent, gelatinoua
mass, which takes the form of the vessel in which the blood was
received. Its coagulation is then complete. The proceiw usually
commences, in the cose of the human subject, in about fif^n mtn*
ntca aflcr the blood has been drawn, and is completed in about
twenty minutes.

The coagulation of the blood is dependent entirely upon the
presence of the fibrin. This fact has been demonstrated in various
ways. In the first place, if frog's blood be filtered, so as to separaw
the globules and leave ihem upon the filler, while the plasma is
allowed to run through, the colorless 6tter«d fluid which contains
the fibrin soon coagulates; while no coagulation takes place in the
moist globules remaining on the filter. Again, if the freshly drawn
blood be stirred with a bundle of rods, as we have already de-
scribed above, the fibrin coagulates upon thcni by itiwlf, while the
rest of the pInHnia, mixed with the globules, remains perfectly fluid.
It is the fibrin, therefore, which, by iis own ooogulation, induces
the solidification of the entire blood. As the fibrin is uniformly
distributed throughout the blood, when its coagulation takes place
the minute filaments whii:h make their appearance in it entangle
in their meshea the globules and the albuminous fluids of the
plasma. A very small quantity of fibrin, therefore, is sufficient to
entangle by its coagulation all the fluid and semi-fluid parts of the
blood, and convert the whole into a volomi*
nous, trembling, jelly-like mass, which is
known by the name of the "crassamentu
or "clot" (Fig. 63.)

A^ soon as the clot bas fairly formed, it
begins to contract anddlminiBh in size. Ex- _
actly how this contraction of iho clot is pro- f
duccd, we are unable lo say; but it is proba-
bly a conlinuatioD of the same process by
which itssolidificaLicn isat Gretaccumplisbed,
or nt least one very similar to it. As the
contraction proceeds, the albuminous fluids
begin to be pressed out from the meahes in
which they were cntaiiglud. A few isolated drops flrat appear on
the surface of the clot. These drops soon increase in aise aad be-

Fig. 03.

Bowl *f rMfntlj* Coiir^
i.<>Tin Blohh. (howiiif iho
vbolv tnaiw uulFurinlj lalldl-

COAOULAriOS OF TBK BLOOD.

209

Hg. 64.

come more namerous. Tbej ran together and coalesce with c&ch
other, as more nod more fluid exudes from the coagulated niaiw,
antil the whole surface of the clot Ja covered with a thin l&yer of
fluid. The clot at Qrst adhercii prcity stntngly to the sides of the
voanel into which the blood was drawn ; but as its eoDtractioti goes
on, iu edges arc separated, and the fluid continues to exude between
it and the sides of the vessel. This exudation
contiaues for ten or twelve hours; the clot
growing constantly ftmallor and firmer, and
the expressed floid more and more abundant.

The globules, owing to their greater ooo'
sistency, do not escape with the albuminous
6uids, but remain entangled in the fibrinous
coagulum. Finally, at the end of ten or
twelve hours tbe whole of the blood has
usually separated into two parta, vi;;., the chi,
which is a red, opaque, dense and resisting,
semi-solid mass, consisting of the fibrin and
the blood globules; and the serum, which is a
transparent, nearly colorless fluid, containing the water, albumen,
and saline matters of the plasma. (Fig. M.)

The change of the blood in coagulation may therefore be ex-
pressed as follows: —

Before coagulation the blood consists of

Bowl <■( *'■.'» 11 11. « T r n
Rl.<'<Mi. BCler lnvlro buur> ;

■bijwinit tb* clot <;-iiirBCtfd
luiil fl>i>llDg In tbo luld ■■ran

111. Oujmrvat; lud 2d. Plamu — oonlittiiiag

Al\er coagulation it is separated into

?ibriD,

Albnmen,

Water,

SjLlW.

,_. _ . , , ( Fibrin and

Ul. Clot, oontaining {

lOlvbultis:

{Allmiiimi,
Vinlmt,

The ooagulation of the blood is hastened or retarded by various
physical conditions, which liave been studied with care by various
observers, but more particularly by Kobin and Verdeil. The con-
ditions which influence the rapidity of coagulation are as follows :
First, the rapidity with which the blood is drawn from the vein,
and the size of the orifice from which it flows. If blood be drawn
rapidly, in a full titrcam, from a large orifice, it remains fluid for a
comparatively long time; if it be drawn slowly, from a narrow
orifice, it coagulates quickly. Thus it usually happens that in the
li

TRB BLOOD.

operation of venesection, the btoot] drawn immct^iatcly &hc.T the
opening of the vein runs freely and coagulates slowly ; while that
which is drawn toward the end of the operation, when the teusioa
of the veins has been relieved and the blood trickles slowlj froni
the wound, coiiguliites quickly. Secondly, the shape of the vessel
into which the blood is received and the condition of ita internal
surfiice. The greater the extent of sarface over which the bloo<l I
comes in contact with the vessel, the more is ita coagulation
hastened. Thus, if the blood be allowed to flow into a tull, narrow,
cylindrical vessel, ur into a shallow plate, it coagulates more rapidly
than if it be received into a hemispherical bowl, in which the ex-
tent of surface 13 less, in proportiaa to the entire quautity of blood
which it cotilain^. For the etame reason, coagulation takes p]ac«
more rapidly in a vessel with a roughened internal surface, than Id
one which is smooth and polished. The blood coagulates most
rapidly when spread out in thin layers, and entangled among the
fibres of cloth or sponges. For the same reason, also, hemorrhagu I
continues longer from an incised wound than from a laccmt«d one;
beoauae the bloody in flowing over the ragged edges of the hwe-
rated bloodvessels and tissues, aolidides upon them readily, and thus
blocks up the wound.

In all these cases, there is an inverse relation between the rapidity
of coagulation and the firmness of the clot. When coagulation
takes place slowly, the clot afterward becomes small and dense, and
the serum is abundant. When coagulation is rapid, there is bat
little coDtraction of the coagutum, an imperfect separation of the
serum, and the clot remains large, soft, and gelatinous.

It is well known to practical physicians that a similar relation
exists when the coagulation of the blood is hastened or retarded bv
disease. In cases of lingering and exhausting illness, or in diseases
of a typhoid or exantheniatous character, with much depression of
the vital powers, the blood coagulates rapidly and the clot remains
soft. In oases of active inflammatory disease, as pleurisy or pneu-
monia, occurring in previously healthy subjects, the blood cctagutates
slowly, and the clot becomes very firm. In every instance, the
blood which has coagulated liquefies again at the oommeocement of
putrefaction.

The coagulation of the fibrin is not a commencement 0/ organizatiotu
The filaments already described, which show themselves in the clot
(Fig. (J2), are not, properly speaking, organized fibres, and are on-
tirely difl'erent in their character from the fibres of areolar tissue, or

COAOtlLATIO.V OF TBE BLOOD.

ajiy otber normal anatomvcal clementa. Tbey are simply the ulti-
mate form which fibrin assumes in coagulating, just as albumen
takes the form of granules under the same circumstances. The
coagulation of fibrin does not differ in character from that of any
other organic substance ; it merely differs in the physical conditions
which give rise to it. All the cuagulable organic subcttanccs are
naturally fluid, and coagulate only when they are placed under
certain unusual conditions. But the particular conditions necea-'
sary for coagolation vary with the different organic substances.
Thns albumen coagulates by the application of heat. Casein, which
ia not affected by heat, coagulates by contact with an acid body.
Pancreatine, again, is coagulated by contact with sulphate of mag-
nesia, which has no effect onalbumcTi. So fibrin, which ia naturally
flaid, and which remains flold so long as it is circulating in the
vessels, coagulates when it is withdrawn from them and brought in
contact with unnatural surfaces. Its coagulation, therefore, ia no
more "spontaneous," properly speaking, than that of any other
organic substance. Still less does it indicate anything like organ-
ization, or even a commencement of it. On the contrary, in the
natural processes of nutrition, librin is assimilated by the tissues
&nd takes part in their organization, only when it is absorbed by
them from the bloodvessels in a fluid form. As uoon a.s it is utice
coagulated by any meant!, it passes inu> an unimtural condition, and
iiiiist he again liquefied and absorbed into the blood before it can
bo animilated.

As the fibrin, therefore, is maintained in its natural condition of
fluidity by the movement of the circulating blood in the interior of
the veAsela, anything which interferes with this circulation wilt in-
duce ita coagulation. If a ligature be placed upon an artery in the
living subject, the blood whiuh stagnates above the ligature coagu-
Utes, justas it would do if entirely removed from the circulation.
If the vessel be ruptured or lacerated, the blood which escapes from
il into the areolar tissue coagulates, because here also it is with-
drawn from the circulation. It coagulates also in the interior of
the vessels aHer death owing to the same cause, viz: stoppage of
the ciraulatioQ. During the last moments of life, when the flow of
Mood through the cavities of the heart is impeded, the fibrin often
toagulates, in greater or less abundance, upon the moving chords
leadineae and the edges of the valves, just as it would do if with-
drawn from the body and stirred with a bundle of twigs. In every
instance, the coagulation of the fibrin is a morbid phenomenon, de-
pendent on the cessatiuu or disturbance of the circulation.

212

THE BLOOD.

Fif. (15.

CII»T Coik'H-LUa, ihnvl&g
lb* gtaaior nccumuUlloii ot

blood-slolinlH Bi tha boitou.

If the blood be allowed to coagulate in a bowl, and the cloi be
then divided by a vertical section, it will be seen that iui lower M
portion is softer and of a deeper red than the upper. (Fig. 66.)
This is because tbe globules, wbioh are of
greater specific gruvity than the plasma, sink^
toward the bottom of the vessel before coagu-
lation lakes place, and accumulate in the
lower portion of tbe blood, This deposit
the globules^ however, isi only partial ; be-
cause they are soon ilxed and entangled by
the solid raaas of the coagulom, and are thoa ,
retained in the position in which they bap-
pen to be at the moment that coagulutioa
takes place.
If (he coagulation, however^ be delayed
longer than usual, or if the globules sink more rapidly than ia cus-
tomary, they will have time to subside entirely from the upper por-
tion of the blood, leaving a layer at tbo surface which is cumpoeed
of plasma alone. "When coagulation then lakes place, this api>er
portion solidifies at the same time with the rest, and the clot then
presents two diSerent portions, viz^ H lower portion of a dark red B
color, in which the globules are accumulated, and an upper portion
from which the globules have subsided, and which is of a grayish
white color and partially transparent. This whitish layer on the
surface of the clot is termed the "baffy coal;" and tbe blood pre-
senting it ia said to be "huffed." It is an appeamnce which often
presents itself in cases of acute inHammatory disease, in which the
coagulation of the blood ia unuaaally retarded.

When a clot with a bufty coat begin.s to contract, the contrac-
tion takes place perfectly well to its upper

' portion, but in the lower part it is impeded

ymgf^^mm^^^ ^y '^^ presence of tbe globules which have

^^■t^^^^Wj accumulated in large quantity at the bottom

l^^k^^^nj of tbe clot. While the lower part of the

V^^^^^Hf/ coagalum, therefore, remains voluminous,

\^^^^/ and hardly separate.** from the sides of the

vessel, its upper colorless portion diminiabea

very much in size; and as its edges separate

from tbo sides of the vessel, they curl over

toward each other, so that the upper surface

of the clot becomes more or less excavated or cup-shaped. (Fig. 66.)

Bawt of Co «»i* i..(tt D

bLiir«d And ca|tp<k(i

COAGULATION OF THE BLOOD. 213

The blood is then said to be "buffed and copped." These appear-
ances do not present themselves underordinary conditions, but only
when the blood has become altered by disease.

The entire quantity of blood existing in the body has never been
very accurately ascertained. It is not possible to extract the whole
of it by opening the large Tesselsjsiace a certain portion will always
remain in the cavities of the heart, in the veins, and in the capil-
laries of the head and abdominal organs. The other methods
which have been practised or proposed from time to time are all
liable to some practical objection. We have accordiogly only
heen able thos far to ascertain the minimum quantity of blood
existing in the body. Weber aad Lehmann* ascertained as nearly
as possible the quantity of blood in two criminals who suffered
death by decapitation ; in both of which oases they obtained essen-
tially similar results. The body weighed before decapitation 138
ponnds avoirdupois. The blood which escaped from the vessels at
the time of decapitation amounted to 12^7 pounds. In order to
estimate the quantity of blood which remained in the vessels, the
experimenters then injected the arteries of the head and trunk with
vater, collected the watery fluid as it escaped from the veins, and
isoertained how much solid matter it held in solution. This
uooanted to 477.22 grains, which corresponded to 4.88 pounds of
blood. The result of the experiment is therefore as follows : —

Blood wUoh escaped from the TeSHels 12.27 ponnds.

" ramsined In the bod7 4.38 "

Wh(de qaantitj of blood in the llrtDg body, IH.tiS

The weight of the blood, then, in proportion to the entire weight
of the body, was as 1 : 8; and the body of a healthy mau, weighing
140 poands, will therefore contain on the average at least 17J
pounds of blood.

' Ph^iiologioal Chemistry, rol. i. p. 638.

214

BKSPIBATION'.

CHAPTER XII.

RE8PIKATI0N.

Ths blood as it circulates in the arterial system baa a bright
scarlet color; but as It passes through the capillaries it gradQally
becomes darker, and on iUs arrival in tlie vciiia its color m a deep
purple, and in some parts of the body nearly black. There are,
therefore, two kinds of blood in the body ; arterial blood, which ia
of a bright color, and venous blood, which is dark. Now it is found
that the dark-colore«] venous blood, wJiicli has been contaminated
by passing through the capillaries, is unfit for further circulation.
It in incapable, in this state, of supplying the organs with their
healthy stimulus and nutrition, and has become, on the contrary,
deleterious and poisonous. It is accordingly carried back to the
heart by the veins, and thcnco sent to the lungs, where it is recon-
verted into arterial blood. The process by which the venous blood
is thus arterialized and renovated, is known as the process of
respiration. M

This process takes place very actively in the higher animals, and V
probably does so to a greater or less extent in all animals without
exception. Its csyentinl conditions are that the circulating fluid
should be exposed to the influence of atmospheric air, or of an
aerated fluid ; that is, of a fluid holding atmoepheric air or oxygen
in Eoluiion. The respiratory apparatus consists essentially of a fl
moist nnd permeable animal membrane, the respiratory membrane,
with the bloodvessels on one side of it, and the air or aerated Said
on the other. The blood and the air, consequently, do not come id
direct contact with each other, but absorption and exhalation take
place from one to the other through the thin membrane which lies
between.

The special anatomical arrangement of the respiratory apparatus
differs in different species of animals. In most of those luhabiliog
the water, the respiratory organs have the form of gitU or bronchia;
that is, delicate filumcnious prolongations of some part of the

BE3PIRATIOX.

215

HcAO J.*it dib(.« or MlUnaBAVeira-

iote^Tnent or mncous membranep, which contain an abundant
sapply of bloodvessels, and wliich hang out freely into the sur-
roaodiDg water. Id many kiads of aquatic lizards, as, for exam-
ple, in menobtanchiui (Fig. H7),

there are upon each side of the ^'B- ^'•

neck three delicate feathery
lafls of threadlike prolonga-
tions from the mucous mem-
brnne of the pharynx, which
pass out through fissurea in
the aide of the neck. Each
taft is composed of a priu-
cipal etom, upon whiuh the
filaments are arranged in a
pinnated form, like the plume upon the shafl of a feather. Each
filament, when examined by itself, is seen to consist of a thiu, rib-
bon-shaped fold of mucoua membranie, in the interior of which
there is a plentiful network of minntc bloodvessels. The dark
blood, as it comes into the filament from the branchial artery, is
exposed to the iuduence of the water in which the 6]amenl is
bathed, and as it circulates through the capillary network of the
gills is reconverted into arterial blood. It is tlmn carried away by
the branchial vein, and paitses into the general current of the cir-
culation. The apparatus is further supplied with a cartilaginous
framework, and a set of muscles by which the gills are gently waved
about ID the surrounding water, and con»tnntty brought into con-
lact with fresh portions of the aerated fluid.

Uost of the aquatic animals breathe by gills similar in all their
essential characters to those described above. In terrestrial and
air-breathing animula, however, the respiratory apparatiis is situated
internally. In thorn, the air ia made to petietrale into the interior
of the body, into certain cavities or sacs called the lungit, which
are Hoed with a vascular mucous membrane. In the salamanders,
for example, which, though aquatic in their habita, are air-breathing
animals, the lungs are two long cylindrical sacs, running nearly the
entirv length of the body, commencing anteriorly by a communi-
cation with the pharynx, and terminating by rounded extremities
at the posterior part of the abdomen. These lungs, or air-sacs,
bare a smooth internal surface; and the blood which circulates
through their vessels ia arterialized by exposure to the air contained
iu their cavities. The air ia forced into the lungs by a kind of

218

RBSriBATIOK.

Fig, 68.

swallowing movement, and is aUar a time regurgitated and dis-
charged, in order to mnke room for a fresh supply.

In frog«, turtles, serpenia, &c, the structure of the lung is a
Httle more complicated, since rettpiratiou is more active iu tliesc
animals, and a more perfect organ is requisite to accomplish the
artenalization of ihc blood. In theao animals, the cavity of the
lung, instead of being simple, ia divided by incomplete partitions
into a number of smaller cavities or "cells.'* The cells all comma-
nicate with the ceutral pulmonary cavity ; and the partitions, wbich
join each other at various angles, are all composed of thin, pro-
jecting folda of the lining membrane, with bloodvessels ramifying
between tliem. (Kig. fi8.) By this arrangement,
the extent of surface presented to the air by the
pulmonary membrane is much increased, and the
arterializatioD of the blood takes place with a
corresponding degree of rapidity.

In tbo human duhjeet, and in all the warm*
blooded quadrupeds, the lungs are constructed
on a pUn which is essentially similar to the
above, and which differs from it only in the
greater extent to which the pulmonary cavity is
subdivided, and the surface of the respiratory
membrane increased. The respiratory apparatus
(Fig. 69) commences with the larynx, which
communicates with the pharynx at the upper part of the neck.
Then follows the trachea, a mtKnbranous tube with oartilaginous
rings; which, upon its entrance into the chest, divides into the right
and left bronchus. These ngnin divide successively into secondary
and tertiary bronchi; the subdivision continuing, while the bron-
chial tubes grow smaller and more numerous, and separate oon-
stantly from each otber. As they diminish in size, the tubes grow
more delicate in structure, and the cartilaginous rings and plates
disappear from their walls. They are finally reduced, according to
KOlliker, to the size of g'j of an inch in diameter; and aro com-
posed only of a thin mucous membrane, lined with pavement epi-
thelium, which rests upon an elustio iibmus layer. They are then
known as the " ultimate bronchial tubes."

Each ultimate bronchial tube terminates in a division or islet of
the pulmonary tissue, about -^j of an inch in diameter, which is
termed a "pulmonary lobule." Kach pulmonary lobulo resembles
in its structure iliu entire frog's tung in miniature. It consists of a

^.z»a or Funn
•fenwlBg It* Inlvnul Mir

RESPIRATION,

217

Pig. «d.

/c^

©^

^'y

^>;^,

j^jj--

;o^

>-.';iJ

-,*=iS'^

'^^

Fig. TO.

bfoachl, aarf ita dNUoa or Iba liut$t Into lobolaa.

VAsculftr membrane inclosing a cavity; which cavity is ilividcrl
iDto a large number of secoudnry compartments by thin septa or
parlitions, which project from its internal surface, (Fig. 70.) These
secondary cavitiea arc the ''pulmonary
cells," or " vesicles." Each vesicle is about
,', of ati inch in diameter; and is covered
on its exterior with a close uetwork of ca-
pillary bloodvessels, which dip down into
ihc spaces between the adjacent vesicles, and
expose ID this wny a double surface to the
air which is contained in their cavities.
Butweea the vesicles, and in the interstices
between the lobules, there is a large (quan-
tity of yellow clastic tissue, which gives
Brmness and resiliency to the pulmonary
structure. The pulmonary vesicles, accord.
ing lo the observations of Kolliber. are ,», ui»n— n..m..*tn«..
lined everywhere with a layer of pavement «»"«»t"'» * c«»ii]roiiofcuie.
epithelium, conUnuuus wiib ihat lu the dM.

218

nKSPIKATrOK.

iiltimnta bronchial tubes. The whole extent of respiratory eur-
liicc in both lungs bus been calculated by Ijicberkiihn' at fourt'^eal
liundre«l square feet. It is plainly impossible to make a precisely
accurate calculation of this extent; but there is every reason Ul
believe that the estimate adopted by Licbcrkiihp, regarded as
approximative, is not by any means an exaggerated one^ The
great multiplication of the minute pulmonary vesicle^ and of the
partitions between them, must evidently increase to an extraor-
dinary degree the extent of surface over which the blood, spread
out in a thin layer, is exposed to the action of the air. These ^
anatomical conditions arc, therefore, the most favorable for its rapid
and complete arterialization.

Rescikatohy Movkhents of tqk Cukst. — The air which la contl
taine<] in the pulmonary lobules and vehicles becomes rapidly vitiai
in the process of respiration, and requires therefore to be expelU
and replaced by a fresh supply. This exchange or renovation of
the air is effected by alternate movements of the chest, of expansion^
and collapse, which arc termed the "respiratory movements of the'
chest." The expansion of the cheat is efttfCted by two seta of mus-
cles, vis., first, the diaphragm, and, second, the intcroostals. While
the diaphragm is in a state of relaxation, it has the form of a vaulted
partition botween the tliornx and abdomen, the edges of which are
nitached to the inferior extremity of the steniom, the inferior
costal cartilages, the borders of the lower ribs and the bodies of
the lumbar vertebne, while its convexity rises high into the cavity
of the chest, as far as the level of the fifth rib. When the fibres
of the diaphrogm contract, their curvature is necessarily dimi-
nished; and they approximate a straight line, exactly in proportion
to the extent of tlieir coutructioit. Consequently, the entire con-
vexity of the diaphragm is diminished in the same proportion,
and it descends toward the abdomen, enlarging the cavity of the
chest from above downward. (Fig. 71.) At the same time the inter-
costal muscles enlarge it in a lateral direction. For the ribs, artlf
culated behind witti the bodies of the vertobrie, and joined in front'
to the sternum by the flexible and elastic costal cartilages, are so
arranged that, in a position of rest, their convexities look obliquely
outward and downward. When the movement of inspiration is
about to commeDce, the first rib is fixed by the contraction of tho;

Ju Sliuou's Chvuiiitry of Miiii, Pliilaaa. «d., IS46, p. 109.

BK8PIBAT0BT MOTBMENTB OF THE CHBST.

219

Fig. 71.

scaleni muscles, aad the intercostal miiBcles then coDtracting siniul-

taneoosly, the ribs are drawn upward. In this movement, as each

rib rotates upon its articulation with the

^inal column at one extremity, and with

Uie sternum at the other, its convexity is

neoeasarily carried outward at the same

time that it is drawn upward, and the pa-

rietes of the chest are, therefore, expanded

laterally. The stemnm itself rises slightly

with the same movement, and enlarges to

some «xtent the antero-posterior diameter

of the thorax. By the simultaneous action,

therefore, of the diaphragm which descends,

and of the intercostal mnacles which lift

the ribs and the sternum, the cavity of the

chest is expanded in every direction, and

the air passes inward, through the trachea

and bronchial tubes, by the simple force of

aspiration.

After the movement of inspiration is ac-
complished, and the lungs are filled with
lir, the diaphragm and intercostal mascles
relax, and a movement of expiration takes
plaoe, by which the chest is partially col-
lapsed, and a portion of the air contained
in the pulmonary cavity expelled. The
movementofexpiration is entirely a passive
one, and is accomplished by the action of ""•* •*!»» •*>« Ago™ of the ehe>t

three diflerent forces. First, the abdominal Tbow iT. wm* wh« expsuded"**
oigans, which have been pushed out of their

osaal position by the descent of the diaphragm, fall backward by
their own weight and carry upward the relaxed diaphragm before
them. Secondly, the costal cartilages, which are slightly twisted
oat of shape when the ribs are drawn upward, resume their natural
pomtion as soon as the muscles are relaxed, and, drawing the ribs
down again, compress the sides of the chest. Thirdly, the pul-
monary tissue, as we have already remarked, is abundantly sup-
plied with yellow elastic fibres, which retract by virtue of their
own elasticity, in every part of the lungs, after they have been
forcibly distended, and, compressing the pulmonary vesicles, drive
oat a portion of the air which they contained. By the constant

DllORlM ILLrilTBATIlia
TBI RiBFiaATOKT HOTI-

■ ■iTTi. — (I. C»t(7 ot iha eh««t.
b, Dlapbragm. Tha dftrk anl-

220

BESPIBATION.

recurrence of these alternating movemcnta of inspiration and expi-
ration, rresh portions of air are constantly introduced into and
cipcUcd from the chest.

The nverage quantity of atmoepherio air, taken into and dis-
charged from the lunge with each respiratory movement, is, ac- M
cording to the resultaof various obeervers, twenty cubic inches, Ac ^
eighteen respirations per minute, this amounts to 860 cuhio inches
of air inspired per minute, 21,600 cubic inches per hour, and 518,400 M
cubic inches per day. But as the movemenla of respiration are
increased both in extetit and rapidity by every muscular exertion,
the entire (quantity of air daily used in respiration is not less than
600.000 cubic inches, or 850 cubic feet.

T]ie whole of the air in the chest, however, is not changed at each
moveraent of respiration. On the contrary, a v«ry considerable ■
quatitity remains in the jtuUnoiinry cavity afler tho most complete
expiration ; and even after tho lungs have been removed from the
chest, they still contain a Urge qnantity of air which cannot be
entirely displaced by any violence short of disintegrating and dia-
organizing the pulmonary tissue, It is evident, therefore, thatoul;
a comparatively small portion of the air In the lungs paHses in and
out with each respiratory movement; and it will require several
successive respirations before all the air in the chest can be entirely h
changed. It has not been possible to ascertain with certainty the V
exact proportion in volume which exists between the air which is
iilteroatoly inspired and expired, or "tidal" air, and that which
remains constantly in the chest, or "residual" air, as it is called.
It has been estimated, however, by Dr. Carpenter,' from the report*
of various observers, that the volume of inspired and expired air M
varies from 10 to 13 per cent, of the entire quantity contained in V
the chest. If this estimate be correct, it will require from eight to
ten respirations to change the whole quantity of air in the cavity of
the chest.

It is evident, however, from the foregoing, that the inspirator;
and expiratory movementa of the cheat cannot be BulHcieat to
change the nir at all in the pulmonary lobules and vesicles. The
air which ie drawn in with each inspiration penetrates only into
the traches and bronchial tubes, until it occupies the place of that
i^hlch was driven out by the last expiraiion. By the ordinary
respiratory movements, therefore, only that small portion of

• Boman Diytiologjr, I'hilitJn. iid., Hii, p. 300.

BSSPIRATOKY MOVSUENTS OF THB OLOTTIB.

221

air lying nearest tbe exterior, in the tmohea and large bronchi,
voald fluctuate backward and forward, without ever penetrating
itito the deeper parts of the lung, were there no other means pro-
vided for its renovation. There are, however, two other forces in
plav for this purpose. The first of these is the diffusive power of
tha gases themselves. The air remaining in the deeper parts of
the cheat is richer in carbonic acid and poorer in oxygen than that
which has been recently inspired ; and by the Uwa of gaseous dif-
Aision there roust be a constant interchange of these gases between
the pulmonary vesicles and the trachea, lending to mix tbem
equally in all parta of the lung. This mutual dida^ion and inter-
mixture of the gases will therefore tend to renovate, pariinlly at
least, the air in the pulmonary lobules and vesicles. Secondly, the
trachea and bronchial tube$ii down to thot^ even of the smallest
size, are lined with a mucous membrane which is covered with
ciliated epithelium. The movement of these cilia is found Lo be
directed always from below upward; and, like ciliary motion
wherever it occurs, it has the eflect of producing a current in the
same direction, in the Kuids covering the mucous membrane. The
sir in the tubes must purtici-

pate, to a certain extent, in Pig- 73.

this current, and a double
stream of air therefore is estab-
lished in each bronchial tube;
one current passing from with-
in outward along the walls of
the tube, and a return current
posing from without inward, «„,,«„„„.,, tp-.. .ho^n,.o,..,d

along the central part of its kBdla<nnJcarr«n(, prodoMd b7«liurr mo^tioa.

»»ity. (Fig. 72.) By this

means a kind of aerial circulation is constantly maintained in the
interior of the bronchial tubes; which, combined with the mutual
diffusinn of the gases and the alternate expunt<ion and collapse of
the chest, effectually accomplish the renovation of the air contained
in all parts of the pulmonary cavity.

Respiratory Moveiib.nt8 of the Glottis. — Beside the move*
iDeols of expanaion and collapse already described, belonging to
the chest, there are similar respiratory movements which take place
in the larynx. If the respiratory passages be examined after death,
in the state of collapse in which they are usually found, it wilt be

222

BESPIBATIOS'.

noticed that the opening of the glottis is very much Btnaller than
the cavity of the trachea below. The glottis itself preseots the
appearaace of a narrow chink, while the passage for the inspired
air widens in the lowtr part of the larynx, and to iho tmchea
constitutes a spacious tube, nearly cylindrical in shape, and over
half an inch in diameter. We have found, for inatanoe, that io
the human subject the space included between the vocal chords
has an area of only 0.15 to 0.1" square inch; while the calibre
of the trachea in the middle of iw length is 0.45 square inch.
This disproportion, however, which is so evident after death, doe*
not exist during life. While respiration is going on, there is a ■
constant and regular movement of the vocal chords, synchronous
with the inspiratory and expiratory movemente of the cheat, by

Fig. 73.

FlS- 74.

la lU ordliur* tvint'Diocinmcaiidtiloa.'— <i.

UaaU McllLuv*' o. i>|HDln( of Ue (Icitli,

Tlie ■am-, villi llir (lulll* df«<ml by
■•pnr».tt>)a of ihd Tncjil rliord* — 41- Voesl
ebvrda. b. ThfiMd (&rlll>t«. et. ArfW-
Hold «artlla(0*. o. (>iirulii( at Ik* (lalll*.

which the size of the glottis is alternalely enlarged and diiiiinishod.
At every inspiration, the glottis opens and allows the air to pass
freely into the trachea; at every expiration it collapses, aod the
air is driven out through it from below. These movements are
called the " respiratory movements of the glottis." They correspond 11
in every respect with those of the cheat, and are excited or retanled "
by similar causes. Whenever the general inovemenia of respiration
are hurried and labored, those of the glottis become accelerated and
increased in intensity at the same time; and when the movemeats
of the chest are slower or fainter than usual, owing to debility,
coma, or the like, those of the glnllis are diminicihed in the sanie
proportion.

CHAN'OES IN THE AIR DURING RBSPIRATION.

223

Hg. 7ft.

Id the respirelory motions of the glottis, as in those of the cheat,
"the movement of inspiration is an active one, and Ihnt of expira-
tion passive. In inspiratinn, the glottis
is openoJ by contraction of the posterior
crico-arytenoid muscles. {i'''g- "5.)
These muscles originate from the po3>
terior surface of the cricoid cartilage,
near the median line; and tlieir 6bres,
ranniog upward and outward, are in-
serted into the external angle of the
arytenoid cartilages. By the contrac-
tion of these muscles, during the move-
ment of iuspiratiou, the arytenoid car-
tilagea are rotated upon their articula-
tions with the cricoid, so that their
anterior extremities are carried outward,
and the vocal chords stretched and sepa-
rate from each other. (Fig. 74.) In this
way, the size of the gloitia may be in-
creased from 0.15 to 0.27 square inch.

In expiration, the posterior crico.
arytenoid muscles are relaxed, and the elasticity of the vocal chords
brings them back to their former position.

The motions uf respiration consist, therefore, of two sets of move-
ncnts : viz^ those of the chest, and those of the glottis. ThcJW move-
ments, in the natural condition, correspond with each other both in
time and intensity. It ia at the same time and by the same nervous
ioiluencc, that the cheat expands to enlialc the air, while the glottis
opens to admit it; and in expiration, the muscles of both chest and
glottis are relaxed, while the elasticity of the tisanes, by a kind of
passive coDtractiou, restores the parts to their origioal condition.

Htm** Linr^x. ro*Tiriiiia
vi(<r,— 11, ThrruU MtlllkM- ^ Bpl-
glolUn. t>f. Arficnalil rartllagwi d.
CrieJkd wirtiUp-. «. H««ioMor trttc-
krjrtfuoM iniuclm. /. TrulMA.

Chaitoes in thk Aib uukino Respi ratios.— The atmoapherio
air, as it ia drawn into the cavity of the lungs, is a mixture of oxj'
gen and nitrogen, in the proportion of ftboot21 per cent., by volume,
of oxygen, to 79 per cent, of nitrogen. It also contains about one-
twentieth per cent of carbonic acid, a varying quantity of watery
vapor, and some traeeo of ammonia. The last named ingredients,
^werer, are quite insignificant in comparison with the oxygen and
oitrogen, which form the principal part of its mass.
If collected and examined, afler passing through the lungs, the

KESPIRATIOK.

nir is found to have become altered in the following essential pai
ticiilflra, viz: —

l8t. It has lost oxygen.

bos

ed carbonic acid. And

Sd. It has abaorbed tlie vapor of water.

Bcmde the two latter subatanccs, there are also exhaled with the
expired air a very small quantity of nitrogen, over and above what
was taken in with inspiration, and a little animal matter in a
gasBoua form, which communicntes a slight but peculiar odor to
the breath. The air is al»o somewhat elevated iu temperature, by
contact with the pulmonary mucous membrane.

The watery vapor, which ia exhaled with the breath, is given off
by the pulmonary mucous nietnbrane, by which it is abeorbed from
the blood. At ordinary temperatures it is transparent and invtai^
bio; but in cold weather it becomes partly condensed, on leaving
the luDgs, :ind appears uuder the form of a cloudy vapor discharged
with the breath. According to the researches of Yalonlio, the
average quantity of water, exhaled daily from the lungs, ia 8100
grains, or about Ij pound.s avoinlupois.

By far the most important pnrt, however, of the changes suffered
by the air in respiration, consists in its losa of oxygen, and its
absorption of carbonic acid.

According to the researches of Valentin, Vieronll, Regnault and
Reiset, &c., the air loses during respiration, on an average, five pel
cent, of its volume of oxygen. At each inspiration, thereforaj
about one cubic inch of oxygen is removed from the air and ab-
aorbed by the blood; and as we have seen that the entire dailji
quantity of air used in n-spiration ia about 850 cubic feet, the entire
quantity of oxygen thus consumed in twenty-four hours is not less
than seventeen and a half cubic feet. This is, by weight,
grains, or a little over one pound avoirdupois.

The oxygen which ihua disappears from the inspired air is no{
entirely replaced in the carbonic acid exhaled; that is, there is less
oxygen in the carbonic acid which is returned to the air by expint*
tion than has been lost during inspiration.

There is even more oxygen absorbed tlian is given off again in
both the carbonic acid and aqueous vapor together, which ara
exhaled from the lungs.^ There is, then, a constant disappearance
of oxygen from the nir uaed iu reupiraliou, and a constant accumu
latioD of carbonic acid.

Lvhmanu's Pliytiolugiiml Clivmiatry, riiiUda. «d., vol. 11. p. 432.

I'll i%:3a
is noli

CBAKOES IK TnE BLOOD DURINQ BESPIRATION. 226

The proportion of oxygen which disappears in the interior of the
hody, over and above that which is returned in the breath under
Che form of carbonic acid, varies in different kinds of animals. In
the herbivora, Jt is about 10 per cent of the whole amount of oxy-
gen inspired ; in the carnivora, 20 or 25 per cent., and even more.
It is a very remarkable fact, also, and an important one, as regards
the theory of respiration, that, in the same animal, the proportion of
oxygen absorbed, to that of carbonic acid exhaled, varies according
to the quality of the food. In dogs, for instance, while fed on ani-
mal food, according to the experiments of Regnault and Reiset, 26
per cent, of the inspired oxygen disappeared in the body of the
animal ; but when fed on starchy substances, all but 8 per cent.
reappeared in the expired carbonic acid. It is already evident,
therefore, from these facts, that the oxygen of the inspired air is
not altogether employed in the formation of carbonic acid.

Gbanoks in the BhooD DURING RESPIRATION. — If we pass from
the consideration of the changes produced in the air by respiration
to those which take place in the blood during the same process, we
find, as might have been expected, that the latter correspond
inversely with the former. The blood, in passing through the
lungs, suffers the following alterations: —
. 1st. Its color is changed from venous to arterial.

2d. It absorbs oxygen. And

8d. It exhales carbonic acid and the vapor of water.

The interchange of gases, which takes place during respiration
between the air and the blood, is a simple phenomenon of absorp-
tion and exhalation. The inspired oxygen does not, as Lavoisier
once supposed, immediately combine with carbon in the lungs, and
return to the atmosphere under the form of carbonic acid. On the
contrary, almost the first fact of importance which has been estab-
lished by the examination of the blood in this respect is the fol-
lowing, viz : that carbonic acid exists ready formed in the venous blood
h^ore its entrance into the lungs; and, on the other hand, that tfie
oxygen tokick is absorbed during respiration passes off" in a free state
with the arteruil blood. The real process, as it takes place in the
long, is, therefore, for the most part, as follows: The blood comes to
the lungs already charged with carbonic acid. In passing through
die pulmonary capillaries, it is exposed to the influence of the air
in the cavity of the pulmonary cells, and a transudation of gases
16

226

rBATioy.

lakes place through the moist animal mcmbrtines of the tang.
Since the bkmd in the capillaries conUiins a larger proportion of
carbonic acid than the air in the air-veaicles, a portion of this gds
leaves the blood and passes out tlirough tho pulmonary membrane; J
while the oxygen, being more nbundant in the air of the vesicles
tbau in the circulating fluid, passes inward at the same Lime, and is
condensed by the blood.

In this double phenomenon of exhalation and absorption, which
takes place in the lungs, both parti of the process are wjually
neces-iary to life. It is essential for the constant activity and DUtri>
tion of the tissues that they be steadily supplied with oxygen by the
blood; and if this supply be cut oil', their functional activity ceases.
On the other hand, the carbonic acid which is produced in tbe body
bj tho processes uf nutrition becomes a poisonoua substance, if it
be allowed to collect in large quantity. Under ordinary circum-
stances, thu carbonic acid is removed by exbalatiou through the
luQgs as fast as it is produced in the interior of the body; but if ■
respiration be suspended, or seriously impetlod, since the production
of carbonic acid couiinues, while its elimination is prevented, it
accumulates iti the blood and in the tissues, aud terminates life id a
few moments, by a rapid dcterioraLioii of the circulating fluid, and
more particularly by its poisonoua efleot on the nervous system.

The deleterious effects of breathing in a confined space will
therefore very soon become apparent. As respiration goes on, tho
oxygen of the air constantly diminishes, and the carbonic acid,
mingled with it by exhaliitiun, increases in quantity. Alter a time
the air becomes accordingly so poor in oxygen that^ by tliat fact
alone, it is incapable of supporting life. At the same time, the
carbonic acid becomes so abuudant iu the air vesicles that it pre-
vents the escape of that which already exists in the blood; and tha
deleterious cfl'ect of its accumulation in the circulating Quid is
added to that produced by u diminished supply of oxygen. An.
increased proportion of carbonic acid in the atmosphere is therefore
injurious iu a similar manner, although there may bu no dirainutioa
of oxygen; since by its [ireseuce it impedes the elimination of the
carbonic acid already formed in tbe blood, and induces tho poison-
ous effects which result from its accnmulalioD. M

Examination of the blood shows furthermore that the interchange "
of gases ill tbe lungs is not comptote but only partial in its exteoL
It results from tho experiments of Magendie, Magnus, and others,
that both oxygen and carbonic acid are contained in both venous

I
I

CHAMOKS IN THB BLOOD DURINO BBSPIRATIOy. 227

ind arterial blood. Magnas' foand that the proportion of oxygen
to carbonic acid, by volame, in arterial blood was as 10 to 26; in
Tenous blood as 10 to 40. The venous blood, then, as it arrives at
the langs, still retains a remnant of the oxygen which it had pre-
rionalj absorbed; and in passing through the pulmonary capil-
laries it gives off only a part of the carbonic acid with which it has
become charged in the general circulation.

The oxygen and carbonic acid of the blood exist in a aUUe of
mlutum in the circulating fluid, and not in a state of intimate chemi-
cal combioaUoD. This is shown by the fact that both of these
snbotanoes may be withdrawn from the blood by simple exhaustion
with an air-pump, or by a stream of any other indifferent gas, such
as hydrogen, which possesses sufficient physical displacing power.
UagnuB found' that freshly drawn arterial blood yielded by simple
agitation with carbonic acid more than 10 per cent of its volume
of oxygen. The carbonic acid may also be expelled from venous
blood by a current of pure oxygen, or of hydrogen, or, in great
meaaare, by simple agitation with atmospheric air. There is some
difficulty in determining, however, whether the carbonic acid of
the blood be altogether in a free state, or whether it be partly in a
state of loose chemical combination with a base, under the form of
an alkaline bicarbonate. A solution of bicarbonate of soda itself
will loae a portion of its carbonic acid, and become reduced to the
oonditioD of a carbonate by simple exhaustion under the air-pump,
or by agitation with pure hydrogen at the temperature of the body.
Lehmann has found* that afler the expulsion of all the carbonic
add removable by the air-pump and a current of hydrogen, there
still remains, in ox's blood, 0.1628 per cent of carbonate of soda;
and he estimates that this quantity is sufficient to have retained all
the carbonic acid, previously given off, in the form of a bicarbonate.
It makes little or no difference, however, so far as regards the pro-
cess of respiration, whether the carbonic acid of the blood exist in
an entirely free state, or ander the form of an alkaline bicarbonate ;
since it may be readily removed from this combination, at the tem-
peratore of the body, by contact with an indifferent gas.

The oxygen and carbonic acid of the blood are in solution prin-
cipally m the blood-ghbuka, and not in the plasma. The researches
of Magnus have shown* that the blood holds in solution 2| times

' la Lehmsnii, op. cit., vol. 1. p. 570.

■ In Robin ind Terdell, op. olt, vol. tt. p. 34.

' Op. cit., vol. 1. p. 393.

* Ib Robin and Vonieil, op. cit., vol. ii. pp. 28—32.

228

IKSPIRATIOV.

as much oxygen as pure water could dissolve at the same tempera-
ture; ntid tbot while the aerum of the blood, separated from the
globules, exerts no iiioro solvent power on oxygen than pnre water,
deBbrinated blood, that i.s, the sorum and globules mixed, dissolves
quite na much oxygen as the fresh blood itself. The same thing is
true with regard tu tho carbonio acid. It is therefore the semi-
fluid blood-globialcs which retain these two gases in soluUon; aod
since the color of the blood depends entirely upon that of the glo-
bules, it is easy to understand why the blood should alter its hue _
from purple to scarlet in passing through the lungs, where the I
globules give up carbonic acid, and absorb a fresh quantity of
oxygen. The above change may readily he produced outside the
body. If freshly drawn venous blood be shaken in a bottle with
pure oxygen, its color changes at once from purple to red ; and the
same change will take place, though more slowly, if the blood bo
simply agitated wilii atmospheric iiir. It is for this reason that the
surfaca of defibrinated venous blood, and the exleraal parts of a
dark-colored c5ot, exposed to the atmcsphcrc, become rapidly red-
dened, while the internal portions retain their original color.

The process of respiration, so far as we have considered it^ con-
sists in an alternate interchange of carbonic acid and oxygen in the
blood of the general and pulmonary circulations. In the pulmonary
circulation, carbonic acid is given off and oxygen absorbed ; while
in the general circulation the oxygen gradually disappears, and is
replaced, in the venous blood, by carbonic acid. The oxygen which
thus disappears from the blood iu the general circulation does not,
for the most part, enter into direct combination in the blood itself.
On the contrary, it exi.-its there, as we have already stated, in the
form of a simple solution. It is absorbed, however, from the bluod
of the capillary vessels, and becomes fixed in the subsUince of the
vascular tiseues. The blixxl irmy be regarded, therefore, in this
respect, as a circulating fluid, destined to transport oxygen from the
lungs to the tissues; for it is the tissues themselves which finally
appropriate the oxygen, and fix it in their substance.

The next important question which presents itself in the study
of the respiratory process relates to (he origin of the cariromc acid in
the ttnous hhmi. It was formerly supposed, when Lavoisier first
discovered the changes produced in the air by respiration, that the
production of the carbonic acid could be accounted for in a very
simple manner. It was thouglit to be produced iu the lungs by a

CHANGES IN THE BLOOD DCBINO BESPIBATION. 229

direct union of the inspired oxygen with the carbon of the blood
in the pnlmonarj vessels. It was found afterward, however, that
this conld not be the case; since carbonic acid exists already formed
in the blood, previously to its entrance into the langs. It was then
imagined that the oxidation of carbon, and the consequent produc-
tion of carbonic acid, took place in the capillaries of the general
circnlation, since it could not be shown to take place in the lungs,
nor between the lungs and the capillaries. The truth is, however,
that no direct evidence exists of such a direct oxidation taking
place anywhere. The formation of carbonic acid, as it is now
understood, takes place in three different modes: 1st, in the lungs;
2d, in the blood ; and 8d, in the tissues.

First, in the lungs. There exists in the pulmonary tissue a pecu-
liar acid substance, first described by Yerdei!' under the name of
"pnenmic** or "pulmonic" acid. It is a crystallizable body, soluble
in water, which is produced in the substanoe of the pulmonary
tissue by transformation of some of its other ingredients, in the
same manner as sugar is produced in the tissue of the liver. It is
on account of the presence of this substance that the fresh tissue of
the lung has usually an acid reaction to teet-paper, and that it has
also the property, which has been noticed by several observers, of
decomposiag the metallic cyanides, with the production of hydro-
cyanic acid; a property not possessed by sections of areolar tissue,
the internal surface of the skin, &c. &c. When the blood, there-
fore, comes in contact with the pulmonary tissue, which is
permeated everywhere by pneuoiic acid in a soluble form, its
alkaline carbonates and bicarbonates, if any be present, are decom-
posed with the production on the one hand of the pneumates of
soda and potassa, and on the other of free carbonic acid, which is
exhaled. M. Bernard has found* that if a solution of bicarbonate
of soda be rapidly injected into the jugular vein of a rabbit, it
becomes decomposed in the lungs with so rapid a development of
carbonic acid, that the gas accumulates in the pulmonary tissue,
and even in the pulmonary vessels and the cavities of the heart, to
such an extent as to cause immediate death by stoppage of the
circulation. In the normal condition, however, the carbonates and
bicarbonates of the blood arrive so slowly at the lungs that as fast
as they are decomposed there, the carbonic acid is readily exhaled
by expiration, and produces no deleterious effect on the circulation.

■ Robin and Verdell, op. cit., toI. li. p. 460.

■ ArobiTflS G«n. de M6d., ztI. 222.

sso

SESPIRATTON.

Secondly, m tke hlood. There is little doubt, altbougb tlie fact has
not been directly proved, that some of the oxygen definitely dis-
appears, and some of the carbonic acid is also formed, in the sub-
stance of the blood -globules during their circulation. Since these
globules are anatomical elements, and since they undoubtedly go
through with nutritive processes ftnatogoiis to those which take
place in the elements of the solid tissues, there is every reason for
believing that they also require oxygen for their support, and that
they produce ca>bonic acid as one of the results of their interstitial
decompoailioo. While the oxygen and carbonic acid, therefore,
oontained in the globules, arc for the most part trjmsi>orted by
these bodies from the lungs to the tissues, and from the tissues back
again to the lungs, they probably take part, also, to a certain extent,
in the nutrition of the blood -globules thetnselves.

Thirdly, m the tismes. This is by far the most iroportftnt soorcc
of the carbonic acid in the blood. From the experimcDta of Spal-
lanzani, W. Edwards, Marchand and others, the following very
important fact hiis been established, viz., thot every organized tissue
and even every organic substance, when in a recent ccndxliart, has On
poicer of ah$orhing oxtjgeii and of exhaling carbonic add, 0. Llebig,
for example,' found that frog's muscles, recently prepared and cora-
pletely freed from blood, continued to absorb oxygen and discharge
Oftrbonic acid. Similar experiments with other tissues have ted
to a similar result. The interchange of gases, therefore, in the
process of respiration, takes place mostly in the tissoes themselves,
it is in their substance that the oxygen becomes fixed and assimi-
lated, and that the carbonic acid lakes it« origin. As the blood in
the lungs gives up its carbonic acid to the air, and absorbs oxygen
from it, so in the general circulation it gives up ita oxygen to the
tissues, and absorbs from them carbonic acid.

We come lastly to examine the exact mode by which the car-
bonic acid originatos in the animal tissues. Investigation shows
that even here it is not produced htj a procats of oxidaiwji, or direct
union of oxygen with the carbon of the tissues, but in some other and more
indirect mode. This is proved by the fact that animals and fresb
animal tiscues will continue to exhale carbonic acid in an atmo-
sphere of hydrogen orof nitrogen, or even when placed in a vacuum.
Marchand found* thai frogs would live for from half an hour to an
hour ID pure hydrogen gas; and that during this time they exhaled
even more carbonic acid thaa in atmospheric air, owing probably

In Lehnumn, op. olt., rot. 11. p. 47^

> Ibid., p. 442.

CHANaSfl IN THE BLOOD DURING RBSPIRATION. 2S1

to the saperior displacing power of hjdrogen for carbonio acid.
For while 16,600 grains' weight of frogs exhaled about 1.13 grain
of carbonic acid per hoar in atmospheric air, they exhaled during
the Bame time in pare hydrogen as much as 4.07 grains. The same
observer found that frogs would recover on the admission of air
after remaining for nearly half an hour in a nearly complete
vacuum ; and that if they were killed by total abstraction of the
air, 16,600 grains' weight of the animals were found to hare
eliminated 9.8 grains of carbonio acid. The exhalation of carbonic
acid by the tissues does not, therefore, depend directly upon the
access of free oxygen. It cannot go on, it is true, for an inde6nite
time, any more than the other vital processes, without the presence
of oxygen. But it may continue long enough to show that the
carbonio acid exhaled is not a direct product of oxidation, but that
it originates, on the contrary, in all probability, by a decomposi-
tion of the organic ingredients of the tissues, resulting in the pro-
dactioD of carbonic acid on the one hand, and of various other
sabstanceson the other, with which we are not yet fully acquainted;
in very much the same manner as the decomposition of sugar
daring fermentation gives rise to alcohol on the one hand and to
carbonic acid on the other. The fermentation of sugar, when it has
once commenced, does not require the continued access of air. It
will go on in an atmosphere of hydrogen, or even when confined in
a close vessel over mercury; since its carbonic acid is not produced
by direct oxidation, but by a decomposition of the sugar already
present For the same reason, carbonic acid will continue to be
exhaled by living or recently dead animal tissues, even in an atmo-
sphere of hydrogen, or in a vacuum.

Carbonic acid makes its appearance, accordingly, in the tissues,
as one product of their decomposition in the nutritive process.
From them It is taken up by the blood, either in simple solution or
in loose combination as a bicarbonate, transported by the circulation
to the langa, and finally exhaled from the pulmonary mucous mem-
brane in a gaseous form.

The carbonic acid exhaled from the lungs should accordingly be
studied by itself as one of the products of the animal organism, and
its quantity ascertained in the different physiological conditions of
the body. The expired air usually contains about four per cent, of
its volume of carbonic acid. According to the researches of Vier-
ordt,' which are regarded as the most accurate on this subject, an

' In Lehmann, op. clt., vol. li. p. 439.

S92 BESFlRATtOK.

adult man gives off 1.62 cubic inch of carbonic acM with each nor-'
inal expiration. Tbis aoiouats to very nearly 1,160 cubic inches
per hour, or &A.een and a half cubic feet per day. Tbis quantity
is, by weighty 10,740 grains, or a little over one pound and a half.
The amount of carbonic acid exhaled, however, varies from Umo to
time, according to many dlflerent circumstaaces; so that no sucb
Gtttimate can repri^senL correctly its quaniity at all timea. These
vnrintions have been very fully investigated by Andral and Gavar-
ret,^ who found that the principal conditions modifying the amount
of tbis gfts produceil were age, sex, constitution aod development.
Tfiu variations were very marked io different individuals, notwith-
standing that tlie experiments were made at the same period of the
day, and with the subject as nearly as possible in the same condn
lion. Thus they found that the quantity of carbonic acid exhaled
per hour in five different individuals was as follows: —

QdAXTRT op CAB301IB ACII> FEB ttWR.

In Bubjoct No. !..■■■ 1^>^7 oabio inohM.
" " " 2 . . . . . 970 " "

" " " 3 1250 " ••

" « " 4 1250 " "

" " " 5 i5£ii " "

With regard to the differeoce produced by age, it was found that
from the period of eight years up to puberty the quantity of car-
bonic acid increases constantly with the age. Thus a boy of eight
years exhales, on the average, 684 cubic inches per hour; while a
boy of fifteen years exhales 981 cubic inches in the same time.
Boys exhale during this period more carbonic acid than girls of tb«
same age. In males this augmentation of the quantity of carbonic
acid continues till the twenty-6fth or thirtieth year, when it reacbes,
on the average, 1398 cubic inches per hour. Its quantity then
remains stationary for ten or fifteen years; then diminishes slightly
from the fortieth to the sixtieth year ; and after sixty years dimi-
oiahes in a marked degree, so that it may fall so low as 1038 cubic
inches. In one superannuated person, 102 years of age, Andral
and Gavarrct found the hourly quantity of carbonic acid to be
only 665 cubic inches.

In women, the increase of carbonic acid ceases at the period of
puberty; and its production then remains constant until the cessa-
tion of menstruation, about the fortieth or fortyfif^h year. At that
time it increases agaiu until aAer iitly years, when it subsequently

> AnnalH dn Cliiiiil« «t d« Fhanuaoiv, 1M3, toI. Till. p. 128.

CHAKGKS IN THE BLOOD DURING RESPIRATION. 2SS

dimiDiahes with the approach of old age, aa in men. Pregnancy,
occurnng at aoj time in the above period, immediately produces a
temporary increase in the quantity of carbonic acid.

The strength of the constitution, and more particularly the <kve-
JopmerU of the muaeuhr si/Mtem, was found to have a very great in-
flaence in this respect; increasing the quantity of carbonic acid
Tery much, in proportion to the weight of the individual. The
largest production of carbonic acid observed was in a young man,
26 years of age, whose frame presented a remarkably vigorous and
athletic development, and who exhaled 1591 cubic inches per hour.
This large quantity of carbonic acid, moreover, in well developed
persons, is not owing simply to the size of the entire body, but
particularly to the development of the muscular system, since an
unaaaally large skeleton, or an abundant deposit of adipose tissue,
is not accompanied by any such increase of the carbonic acid.

Andral and Gavarret finally sum up the results of their investiga-
tions as follows : —

1. The quantity of carbonic acid exhaled from the lungs in a
given time varies with the age, the sex, and the constitution of the
aabject.

2. In the male, as well as in the female, the quantity of carbonic
acid varies according to the age; and that independently of the
weight of the individual subjected to experiment.

8. During all the periods of life, from that of eight years up to
the most advanced age, the male and female may be distinguished
by the different quantities of carbonic acid which they exhale in a
given time. Other things being equal, the male exhales always a
larger quantity than the female. This difference is particularly
marked between the ages of 16 and 40 years, during which period
the male usually exhales twice as much carbonic acid as the female.

4. In the male, the quantity of carbonic acid increases constantly
from eight to thirty years ; and the rate of this increase undergoes
a rapid augmentation at the period of puberty. Beyond thirty
years the exhalation of carbonic acid begins to decrease, and its
diroination is more marked as the individual approaches extreme
old age; so that near the termination of life, the quantity of carbonic
aeid produced may be no greater than at the age often years.

6. In the female, the exhalation of carbonic acid increases accord-
ing to the same law as in the male, from the age of eight years
antil puberty. But at the period of puberty, at the same time with
the appearance of menstruation, the exhalation of carbonio wid,

284

IBSPIBATtOX.

contrary to what happens in the male, ceases to increase; nod it
afterward remains stationary so long as ibe menslrual periods recur
with regularity. At the cessation of the meoses, the quantity of
carbonic acid exhaled increases in a notable manner; then it de-
creases again, as in the male, as the woman advances toward old age.

6. During the whole period of pregnancy, the exhalalioo of car-
bonic acid riseH, for the Lime, to the same ataudard as id women
whose meases have ceased.

7. In brjth sexes, and at all ages, the quantity of carbonic acid ia
greater as the constitution is stronger, and the muscular system
more fully developed.

Prof. Scharling, in a similar series of Investigatioas,' found that
the quantity of carbonic acid exhaled was greater during the diges-
tion of food than in the fastiog condition. It is greater, alsp, in the
waking state than during sleep: and in a stale of activity than in
one of quietude. It is diminished, also, by fatigue, and by most
conditluua which interfere with perfect health.

The process of respiration is not altogether conGned to the longs,
but the interchange of gases takes place, also, to some extent through
the skin. It has been found, by inclnsing one of the limbs in an
airtight case, that the air in which it is confined 1o.<h;s oxygen and
gainfl in carbonic acid. By an experiment of this sort, performed by
Prof. Scliarling,' it was ascerlained that the carbonic acid given off
from the whole outaneous surface, in the human subject, is from
one-sixiieih to one-thirtieth of that discharged during the same
period from the lungs. In the true amphibious animals, that is,
those which breathe by luugs, and can yet remain under water for
an indctiinto period without injury [as frogs and salamanders), the
respiratory function of the skin is very active. In these animals,
the integument ia very vascular, moist, and flexible; and is covered,
not with dry cuticle, but with a very thin and delicate layer of
epithelium. It, therefore, presenLi all the conditions necessary for
the accnmpHshmcTit of rcapiraiion; aiid while the animal remains
beneath the surface, and the lungs are in & stale of inactivity, the
exhalation and absorption of gases continue to take place through
the skin, and the process of respiration goes on in a nearly unin*
terrupted manner.

1 Aniialtfi de CKImle et ie Phananole, vol, vlll. p. 4!l<t.

■ In Cftrpenter'a Hanutu PbyticAogy, 11ill«la. rd , l£3», p. 308.

ANIKAL HKAT. 286

CHAPTER XIII.

ANIMAL HEAT.

Oss of the most important phenomeDa presented bj animals and
▼egetablea is the property which they possess of maintaining, more
or less constantly, a standard temperature, notwithstanding the
external vicissitades of heat and cold to which they may be sub-
jected. If a bar of iron, or a jar of water, be heated up to 100° or
200° F., and then exposed to the air at 50° or 60°, it will imme-
diately begin to lose heat by radiation and conduction; and this
loss of heat will steadily continue, until, after a certain time, the
temperature of the heated body has become reduced to that of the
sarroanding atmosphere. It then remains stationary at this point,
unless the temperature of the atmosphere should happen to rise or
ftll: in which case, a similar change takes place in the inorganic
body, its temperature remaining constant, or varying with that of
the surrounding medium.

With living animals, Uie case is different. If a thermometer be
introduced into the stomach of a dog, or placed under the tongue
of the human subject, it will indicate a temperature of 100** F., very
nearly, whatever may be the condition of the surrounding atmo-
sphere at the time. This internal temperature is the same in sum-
mer and in winter. If the individual upon whom the experiment
bas been tried be afterward exposed to a cold of zero, or even of 20°
or 80° below zero, the thermometer introduced into the interior of
the body will still stand at 100° F. As the body, during the whole
period of its exposure, must have been losing hoat by radiation and
conduction, like any inorganic mass, and has, notwithstanding, main-
tained a constant temperature, it is plain that a certain amount of
heat has been generated in the interior of the body by means of the
vital processes, sufficient to compensate for the external loss. The
internal beat, so produced, is known by the name of vital or animal
heaL

There are two classes of animals in which the production of vital

2S6

HEAT.

heat takes place with such activity that their blood and internal
organs are nearly always very much above the external temper-
ature; and which are therefore called "warm-blooded aDimals."
These are mammaHa and birds. Among the birds, some specieSi
as the gull, have a temperature ns low as 100* F.; but in naojt of
them, it is higher, sometimes reaching as high aa 110° or 111°. In
the mammalians, to which class man belongs, the animal tempera-
ti3re is never far from 100". In tlie seal and the Greenland whnle,
it has been found to be 104°; and in the porpoise, which is an air-
breathing animal, 99°.5. In the human subject tt is 98° to 100°.
When the temperature of the air is below this, the external parts
of the body, being moat exposed to the cooling influences of radia-
tion and conduction, fall a little below the standard, and may indi-
cate a temperature of 97°, or even several degrees below thia poinL
Thus, on a very cold day, the thinner and more exposed parts, such
as the nose, the ears, and the ends of Che fingers, may become
cooled down considerably below the standard temperature, and may
even be congealed, if the cold be severe; but the temperature of
the internal organs and of the blood still remains the same uuder
all ordinary exposures.

If the cold be so intense and long continued as to affect tbe
general temperature of the blood, it at once becomes fatal. It has
been found that although a warm>blooded animal usually preserves
its natural temperature when exposed to external cold, yet if tbe
actual temperature of the blood become reduced by any means
more than 5° or 6° below its natural standard, death inevitably
results. The animal, under these circumstances, gradually becomes
torpid and insensible, and all the vital operations finally cease.
Bird»i, acconlingly, whose natund temperature is about 110°, die if
the blood be cooled down to 100°, which is the natural temperature
of the mammalia; and the mammolians die if their blood be cooled
down below 94° or 95°. Each of these difterent classes has there-
fore a natural temperature, at which the blood must be maintained
in order to sustain life; and even the different species of aoimala,
belonging to the same class, have each a specific temperature which
is charade rislic of them, and which cannot be raised or lowered, to
any coosiderable extent, without producing death.

While in the birds and mammalians, however, the internal pro-
duction of heat is so active, that their temperature is nearly always
considerably above that of the surrounding media, and suffers but
little variation; in reptiles end fish, on the other hand, its produc-

ANIMAL HEAT.

237

tion is mnch less rapid, and tbe temperature of their bodies differs
bat little from that of the air or water which tbej inhabit. Birds
and mammaliaDS are therefore called "warm-blooded," and reptiles
and fish "cold-blooded" aoimals. There is, however, no other dis-
tiactioQ between them, in this respect, than one of degree. In
reptiles and fish there is also an internal source of heat; only this
is not so active as in the other classes. Kven in these animals a
diflference is usually found to exist between the temperature of their
bodies and that of the surrounding media. John Hunter, Sir
Hamphrej Davy, Czermak, and others,' have found the temperature
of Proteus anguinus to be 63*^.5, when that of the air was 56°.4;
that of a fr9g 48°, in water at 44°.4; that of a serpent 88°.4t}, in
air at 81^5; that of a tortoise 84^ in air at 79^6; and that of fish
to be from 1**.7 to 2°.b above that of the surrounding water.

The following list* shows the mean temperature belonging to
animals of different classes and species.

Bnos.

Havmalia.

Rbptilb.

Asmkh.

Ukah Tbhpsbatobx.

SwaltoT 1110.25

Heron .

1110.2

Raren ,~

108O.fi

Pigeon .

107O.6

Fowl .

106O.7

. Gnll .

lOOO.O

' Sqaiml

105O

Goat .

102O.6

Cat

101O.3

Hare .

100O.4

990.6

Dog .

930.4

Han

980.6

. 'Ape

950.9

Toad .

510.6

Carp

510.25

. Tenoh .

520.10

FtBH.

In the invertebrate animals, as a general rule, the internal heat
is produced in too small quantity to be readily estimated. In some
of the more active kinds, however, such as insects and arachnida,
it is occasionally generated with such activity that it may be
appreciated by the thermometer. Thus, the temperature of the
butterfly, when in a state of excitement, is from 6° to 9° above

■ Simon's Chemlatrr of Man, Philadelphia edition, p. 124.

■ Ibid., i^. 123—126.

AyiVAt n«AT.

that of tlie air ; ani] that of the humble-bee Troni 3° to 10° higher
than the exterior. Accordinjif to the experiments oF Mr. Kewport,*
the interior of a hive of bees may have a temperature of 48°^,
when the external atmosphere is at 34°^, even while the insects
are quiet; but if they be exciteU, by tapping on the oolsido of the
hive, it may rise to 102°. In all cases, while the insect is at rest,
the temperature ig very moderate; but if kept in rapid motion in
a con6necl space, it may generate heat enough to affect the thermo-
meter sensibly, in the course of a few minutes.

Even in vegetables a certain degree of heat-prod ocing power is
occasionally manifest. Usually, the expoBed surface of a plant u
so extensive in proportion to its mass, that whatever calonc may
be generated is too rapidly lost by radiation and evaporation, to be
appreciated by ordinary means. Under some circumstances, how-
ever, it may accumulate to such an extent as to become readily
perceptible. In tbe process of making, for example, when a large
quantity of germinating grain is piled together in a mass, its ele-
vated temperature may be readily distinguished, both by the hand
and the thermometer. During the flowering process, also, an una-
sual evolution of heat takes place in plants. The flowers of the
geranium have been found to have a temperature of 87°, while
that of the air was SI"] and the thermometer, placed in the centre
of a clump of blossoms of arum cordifolium, has been seen to rise
to 111®, and even 121°^ while the temperature of the external air
was only 66°.'

Dutrouhet has moreover found, by a series of very ingeirioos aod
delicate experiments,' that nearly all parts of a living plant gene-
rato a ccrutin amount of heat. The proper heat of the plant is
usually so rapidly dissipated by the continuous evaporation of its
fluids, that it ia mostly imperceptible by ordinary means; but if
this evaporation be prevented, by keeping the air charged with
watery vapor, the heat becomes sensible and can be appreciated by
a delicate thermometer. Butrochet used for this purpose a thermo-
electric apparatus, so constructed that an elevation of temperature
of 1° F., in tUo substances examined, would produce a deviatiou in
the needle of nearly nine degrees. By this means he found that he
could appreciate, wttliout diflficulty, the proper temperature of tho
plant. A certain amount of heat was constantly generated, during

' Carpent»r'H Oenera-l dbA CompArntivo Phjsiolog^, I'hiladelpbia, tfiiSl, p. &I>2.

• Cari>ent«r'B Gen. adiI Comp. Phjrttiologjr, p. 84ti,

* AnnaJa dsi Sciencwi NftLnrvlLM, Sil aeriea, icil. p. 277>

ANIUAL HBAT. 289

the day, ia the greoQ stems, the leaves, the bads, and even the
roots and fruit. The maximum temperature of these parts, above
that of the sarroandiDg atmosphere, was sometimes a little over
one-half a degree, Fahrenheit; though it was often considerably
leas than thia.

The dififerent parta of the vegetable fabric, therefore, generate
different quantities of caloric. In the same manner, the heat-
prodacing power is not equally active in different species of ani-
mala; bat its existence ia nevertheless common to both animals
and vegetables.

With r^ard to the mode of generation of thia internal or vital
beat, we may start with the assertion that its production depends
upon changes of a chemical nature, and is so far to be regarded as
a chemical phenomenon. The sources of heat which we meet with
in external nature are of various kinds. Sometimes the heat is of
a physical origin ; as, for example, that derived from the rays of
the ann, the friction of solid substances, or the passage of electric
currents. In other instances it ia produced by chemical changes ;
and the most abundant and useful source of artificial heat is the
oxidadon, or combustion, of carbon and carbonaceous compounds.
Wood and coal, substances rich in carbon, are mostly nsed for thia
purpose ; and charcoal, which is nearly pure carbon, is frequently
employed by itaelC These substances, when burnt, or oxidized,
evolve a lai^ amount of heat; and produce, as the result of their
oxidation, carbonic acid. In order that the process may go on, it
is of coarse necessary that oxygen, or atmospheric air, should have
free access to the burning body; otherwise the combustion and
evolution of heat cease, for want of a necessary agent in the chemi-
cal combination. In all these instances, the quantity of heat gene-
rated ia in direct proportion to the amount of oxidation ; and may
be meaaured, either by the quantity of carbon consumed, or by that
of carbonic acid produced. It may be made to go on, also, either
rapidly or slowly, according to the abundance and purity in which
oxygen ia auppHed to the carbonaceous substance. Thus, if char-
coal be ignited in an atmosphere of pure oxygen, it barns rapidly
and violently, raises the temperature to a high point, and is soon
entirely consumed. On the other hand, if it be shut up in a close
stove, to which the air is admitted but slowly, it produces only a
slight elevation of temperature, and may require a much longer
time for ita complete disappearance. Nevertheless, for the same
quantity of carbon consumed, the amount of heat generated, and

340

AKIHAtr HBAT.

that of carbonic acid produced, will be equal m the tvro cases. In
one iu»laiiuti wu liavo » ra]Md cumbuBtioi), in the other a slow com-
bustion ; the total effect being the same in both.

Such is the mode in which heat is commonly produced by arU6-
cial means. Its evolmion is here dependent upon two principal
conditions, wbich ore essential to it, and by which it is always
accompanied, viz., the coosumplion of oxygen, and the production
of carbonic aeid.

Now, since the two phenomena jast mentioned are presented
also by the living body, and since they are accompanied here, too,
by the production of animal hoai, it was vory natural to suppose
that in the animal organization, as well as elsewhere, the internal
heat must be owing to an oxidation or combustion of carbon. Ac-
cording to Lavoisier, the oxygen taken into the lungs was sup-
posed to combine immediately with the carbon of the pulmonary
tissues and fluids, producing carbonic acid, and to be at once re-
turned under that form to the atmosphere; the same quantity of
heat resulting from the above process as would have been produced
by the oxidation of a similar quantity of carbon in woo*) or coal.
Accordingly, he regarded the lungs as a sort of stovo or furnace,
by which the rest of the body was warmed, through the mediuna of
the circulating blood.

It was soon found, however, that this view was altogether erro-
neous; for the slightest examination shows that the lungs are not
perceptibly warmer than the rest of the body; and that the heat-
producing power, whatever it may be, does not reside exclusively
in the pulmouary tissue. Furthermore, Eubse<|ucnt investigations
showetl the following very important facts, which wo have already
mentioned, vi>:^ that the carbuoic auid is not formed in the lungs,
but exists in the blood before its arrival in the pulmonary capilla*
ries; and that the oxygen of the inspired air, so far from combining
with carbon iu the luitgH, is taken up in solution by the blood-
globules, and carried away by the current of the general circalation.
It is evident, therefore, that this oxidation or combustion of the
blood must take place, if at all, not in the lungs, but in the capiU
larics of tbc various organs and tissues of the body.

Liebig accordingly adopted Lavoisier's theory of the produotioQ
of animal heat, with the above modification. He believed the heat
of the anima! body to Iw produced by the oxidation or combustion
of certain elements of the food while still circulating in the blood;
these substances being converted into carbonic acid and water by

AyiMAL BKAT.

241

the oxidatioD of tbeir ciirbon and hydrogen, and immediately ex-
pelled from the body without ever Imving formed a part of the solid
tissues. He therefore divided the food into two different classea of
alimentary substances; viz,, 1st, the nitrogenous or plwilic elements,
which are introduced in comparatively smoll quantity, and which
Are to be actually converted into the substance of the tissues, such as
albumen, muscular flesh, iic; and 2d, the hydi-o-carhons or rapiratory
dements, such as sugar, starch, and fiit; which, according to his view,
are taken into the blood solely to be burned, never being a^imilated
or converted into the tissues, but only oxidised in tite circulation,
sad immediately expelled, as al>ove. under the form of carbonic
acid and water. He therefore regarded these elements of the food
only Hs 60 much fuel ; destined simply to maintain the heat of the
body, but taking no part in the proper function of nutrition.

The above theory of nnimul heui has been vary generally adopted
'l&d acknowledged by the medical profession until withiu a recent
fwriod. A few years ago, however, some of its deficiencies and
inconsistencies were pointeil out, by Lehmann in Germany, and by
Kobin and Verdcil in France; and since that time it has begun to
low ground and give place lo a different mode of explanation, more
in accordance with the present state of physiological science. We
believe it, in fact, U; be altogether erroneous; and incapable of
explaining, in a satisfactory manner, the phenomena of animal heat,
as exhibited by the living body. We shall now proc^icd to pass in
review the principal objections to the theory of combustion, con-
■idered as a physiological duetriud.

L It is not stall ne^resAsry t^) rt^gard the evolution of beat as

dependent solely on direct oxidation. This is only one of its
sources, atf we see constantly in exlernal nature. The suu's raya,
mechanical friction, electric currents, and more particularly a great
variety of chemical action.", such as various saline combinations and
decompositions, are all capable of producing heat; and even simple
soluUons,such as the solution of caustic pota^isa in water, the mixture
of Bolphurio acid and water,or of alcohol and water, will often pro-
duce a very seusible elevation of lecnperature. Now we know that
in the interior of the body a thousand diRereni actions of this
nature are constantly going on; solutions, combinations and dccom-
poaitioDS in endless variety, all of which, taken together, are amply
soOicieot to account for the production of animal beat, provitletl the
theory of combustion should be found insufficient or improbable.
16

242

ANIMAL HEAT.

II. In vcgctnbles tlicro is an internal production of he&t, as well
as in animals; a fact which has been t'uUy (lemonstrnted by the
experimenui of Diiirochet and others, already described. In vcge-
tubleit, liuwever, Iho absorption of oxygen and exhalation of car-
bonic ucid do not take place; excepting, to some extent, during the
night. On iho contrary, t)ie diurnal prticess in vcgetablea, it is well
known, is exactly the reverse of this. Under the influence of the
solar light thty absorb carbonic acid and exhale oxygen. And it
is exceedingly remarkable that, in Dulrocliet's experiments, be
found that the evolution of heat by plants was always accompanied
by the disappearance of carbonic acid and the exhalation of oxygen.
Plants which, in the daylight, exhale oxygen and evolve heat, if
placed in the dark, imn:tediately Wgin to absorb oxygen and exhale
carbonic acid; and, at the same time, the evolution of heat is sus*
pendcd. Dutrochet even found that the evolution of beat by plants
presented u regular diurnal variation; and that its maximum of
intensity was about the middle of the day, jusl at the time alien Ote
absorption of carbonic acid a/id the exhalation of oxygen are going on
iviih the grtalesl acUviiy. The proper heat of plants, therefore, can*
uot be the result of oxidation or com bust ion, but must be dependent
on an entirely diilerent process.

I
i

III. In animals, the quantities of oxygen absorbed and of carbonic
acid exhaled do not correspond with each other. Most frequently
a certain amount of oxygen disappears in the boiiy, over and above
that which is returned in the breath under the form of carbonic
acid. This overplus of oxygen has been said to unite with the
hydrogen of the food, so as to form water which also passes out
by the tiings; but this is a pure assumption, resting on no direct
evidence whatever, for wc have no experimental proof that any
more watery vapor is exhaled from the lungs than is supplied by
the fluids taken into the stomach. It is superfluous, therefore, to
assume that any of it is produced by the oxidation of hydrogen.

Furthermore, the pntporiion of overplus oxygen which disap-
pears in the body, beside that which is exiialcd in the carbonic acid
vf the breath, varies greatly in the same animal according to the
quality of the food. Begiiault and Keiset' found that in dogs, fed
on meat, the oxygen which reappeared under the form of carbonic
acid was only 76 per cent, of the whole quantity absorbed; while

Aiiii&Ji;ii lid Chlinie el de Plj/MiiiU*, 3d 9«riv», xxvi. p. 428.

AynrAL itbat. 24J

in dogs fed on vegeutble substances it amountGd to over 90 per
,eent lu some instaric<?j»,' where the animals (rabbiu and fowls)
were fed on bread and grain exclusively, the projjortion of expired
oxygen amounted to 101 or even 102 per cent.; that is, nvtreoxygm
mWat actually eontained in the carbonic acidexhakd, Oian fuid been alh
torbed in a/rce Btate/rom tfu almmphere. A portion, at least, of tbe
carbonic acid must therefore have been produced by other means
than direct oxidation.

IV. It has already been shown, in a previous chapter, that the
carbonic acid which is exhaled from the lungs is not primarily
formed in the blood, but makes its appearance in the substance of
tlie tissues themselves; and furthermore, that even here it does not
originate by a direct oxidation, but rather by a process of decom-
position, similar to that bv which sugar, in fermentntion, is resolved
into alcohol and carbonic acid. We uoderatund frum this how to
explain tbe singular fact alluded to in the last paragraph, viz., the
ihnndant production of carbonic acid, under some circumstances,
with a comparatively small supply of free oxygen. The statement
made by Liebig, therefore, that starchy and oily matters taken with
the food are immediately oxidized in the circulation without ever
being aflsimilaled by the tissues, is without foundation. It never,
in fact, rested on any other ground than a supposed probability;
lud as we see that carbonic acid is abundantly produced in the
body by other menns, we have no longer auy reasou for assuming,
without direct evidence, the existence of a combustive process in
the blood.

y. l*he evolution of heat in the animal body is nut general, as it
would be if it resulted from a combut^tion of the blooit ; but local,
lince it takes place primarily in the substance of the tissues them-
Belvea. Various causes will therefore produce a local elevation or
depreosion of temperature, by modifying the nutritive chauges
which take place in the tissues. Thus, in the celebrated experiment
of Bernard, which we have often verified, division of the sympa-
thetic nerve in the middle of the neck produces very soon u marked
elevation of temperature in the corresponding side of the head and
face. Local inflaminatii>n8, also, increase very sensibly the lenipcra-
tare of the part in which they are seated, while that of the general

> Aniwlvi de Chitnle rt <1« Khrtiqn*, M Mrf«*, nrl. pp. -iOD — ISl.

244

BSAT.

mass of the blood is not nltered. Fiually it has been demonstrated
by Bernard that in the natural state of the system there is a marked
ditference ia the temperature of the different organs and of the blood
returning from them.' The method adopted by this experimenter
was to introduce, in the living anima}, the bulb of n fine thermo-
meter successively into tlie bloodvessels entering and those leaving
the various internal organs. The diAerence of temperature in those
two situations showed whether the blood had lost or gained in heat
while traversing the capillaries of the organ. Bernard found, in
the iirst place, that the blood in passing through the lungs, so far
from increasing, was absolutely diminished in temperature; the
blood on the left side of the heart being sometimes a little more
and sometimes a little less than one-third of a degree Fahr. lower
than on the right side. This slight cooling of the blood in the
lungs is owing simply to its exposure to the air through the pul-
monary membrane, and to the vaporization of water which takes
place in these organs. In the abdominal viscera, on the contrary,
the blood i^ increaitcd in temperature. It is sensibly warmer in the
portal vein than in the aorta; and very considerably warmer in the
hepatic vein than in either the portal or the vena cava. The blood
of the hepatic vein is in fact warmer than that of any other pars
of the body. The production of heat, therefore, according to Ber-
nard's observations, is more active in the liver than in any other
portion of the system. As the chemical processes of nutrition are
necessarily different in the diQ'erent tissues and organs, it la easy to
understand why a specific amount of heat should be produced in
each of them. A similar fact, it will be recollected, wns noticed by
Dulrochet, in regard to the different parts of the vegetable orgau-
iaation.

TI. Animal he.it has been supposed to aland in a special relation
to the production of carbonic acid, because in warm-blooded animals
the respiratory process is more active than in those of a lower
temperature; and because, in the same animal, au increase or
diminution in tbe evolution of heat is aocompanied by a correspond-
ing increase or diminution in the products of reapirntion. But
this is also true of all the other excretory products of the body. An
elevation of temperature is accompanied by an increased activity
of ufl the nutritive processes. Not only carbonic acid, but the

!
I

■ Oiax«it« Il(-Ui<>n)adair«, Aug. 29 and Sw^i. 26, IttStJ.

AN'IUaL HE.vT.

245

ingrdientsof the urine and the perspiration are flischargod in larger
qaaiitity than usual. An increased supply of food also is required,
as well as a larger quantity of oxygen ; and the digestive and
secretory processes both go on, at the same time, with unusual
acUvity.

Animal heat, then, is a phenomenon which results from the
simultaneoas activity of many diS'erent processes, taking place in
many dtfTerent organs, and dependent, umloubtedly, on diflerent
chemical changes in each one. The intruduetion of oxygen and
the exhalation of carbonic acid have no direct connection with each
other, but are only the beginning and the end of a long series of
coDtinuoDS obangea, in which all the tiasuus of the body successively
take a part. Their relation is precisely that which exists between
the food introduced through the stomach, and the urinary ingre-
dients eliminated by the kidneys. The tissues require for their
nutrition a constant supply of solid and liquid food which Is intro-
duced through the stomach, and of oxygen which is introduced
through the lungs. The diaintegration and decomposition of the
tissues give rise, on the one band, to urea, uric acid, &c., which are
discharged with the urine, and on the other hand to carbonic ncld,
which is exhaled fn.im the lungs. But the oxygen is not directly
converted into carbonic acid, any more than the food is directly
converted into urea and the urates.

Animal tie:tt is nut to bo regarded, therefore, aa the result of a
combuBtive process. There is no reason for believing that the
greater part of the food is "burned^' in the circulation. It is, on
the contrary, assimibted by the substance of the tissues; and these,
in their subuequent disintegration, give rise to several excretory
products, one of which is mrbonic acid.

The numeroua cornbinationa and decomposition a which follow
each other incessantly during the nutritive process, result in the
production of an internal or vital heut, which is present in both
animals and vegetables, and which varies in amount in different
species, in the same individual at diiTerent times, and even io
liSerent paria and organs of the same hotly.

2i8

THE CIRCULATION.

CHAPTER XTV,

THE CIRCULATION.

The blood may be regarded aa a nutritious fluid, holding in
solution all the ingro-lierit-s necensury for the formation of the
tissues. In someaniiniila nnd vegetables, of the lowest organisation,
such IIS infusorin, polypes, algie, and the like, neither blood nor
circulntion is required; since all partaof the bcxly, Imviog a similar
atruclure, absorb nourishment equally from the surrounding mcdin,
and carry on nearly or quite the same chemical procesaea of growth
and assimilation. In the higher animals and vegetables, however,
as well as in the human subject, the case is different. lu them, the
Btructure of the b*Kly ia cotnpnund. Diflerent organs, with widely
difl'erent functions, are eituaietl in difl'erent parta of the frame; and
each of these functions is more or less eaijential to the continued
existence of the whole. In the intestine, for example, the procesd
of digestion takes place; and the prepared ingredients of the food
are thence abs<)ri>eil into the bloodvessuly, by which they are
transported to distant tissues and organs. In the lungs, again,
the blood absorbs oxygen which is afterward to be appropriated by
the tt.HSuea; and carbuiiiu acid, which was produced in the tissues,
is exhaled from tho lungs. In the liver, the kidneys, and the skin,
other substances S'^ain are produced or eliminated, and these local
proce.*«»es are all of them necessary to the preservation of the general
organization. The circulating fluid is therefore, in the higher
animals, a maaiis of tra»eporlaiwn, by which the substances pro*
dueed in pariieular organs are dispersed throughout tho body, or
by which substances produced generally in the tissues are conveyed
to particular organs, in order to be eliminated and expelled.

The circulatory appanitua consists of four diflbrcnt parts, viz:
1st. Tho hfiart; a hollow, muscular organ, which receives the blood
at one oriSce and drives it out, in successive impulses, at another.
2d. The arteries; a series of branching tubes, which convey the
blood from the heart to the different tissues and organs of the body.

TDK HEABT.

247

3d. The capillarvfi; a aetwork of tnioutg inosculnting tubules,
which are interwoven wiiU che substance of the tis»iies, and which
hring the blood into iniimate contact with the cells (ind fibres of
which they are oomposeti; and 4ih. The veins; a set of converg-
ing vessels, destined to collect the blood from tfie capillaries, and
return it to the heart. In uaub of these four dJtferurit part;) of the
circalatory appnrataH, tho movement of ihe blood t8 peuuliar and
dependent on special comlitiuns. It wi!l thcreiure require to be
studied in each one of them separately.

rilE HBART.

^H The structure of the heart, and of the large vessels connected
^BHth it, varie* onnsiderably in different clashes uf anitnaU, owing to
^■he different arrangement of the respiratory organs. For the respi-
^^atory apparatus being one of thij modt important in the boly, and

the one most closelv connected

by anatomical relations with *''?■ "^■

the orgOQH of circulation, the

latter are neflessartly modifie-l

in structure to <'orrca[>onrl with

the former. In fish, for exam-
ple (Fig. 76), the heart is an

organ consisting of two princi-
pal cavities: an ourlole (a) into

which the blood is received from

the central extremity of ihe

vena cava, and a ventricle (&)

into which the hlooil is driven

by ihecontraction of the auricle.

he ventricle is considerably

arj^er and more powerful than

the auricle, and by its contmc-

tion drives the blood into the

main artery supplying the gills.

In the gills [cc) the blood is

arterialized ; alYer which it is

collected by the branchial veins.

The»e veins unite upon the median line to form the aorta ('/) by

wbtch the blood is Gimllv distributed throu;'huut the fratue. In

C I «ri-L(TI n* nr Flan. — it. Aartcl*. *,
Vratrlrln. «. UIIU. it Aiitta. M. Vm>(tariu

24S

THB CIRCrLATrOS.

Fig. n.

these nnimala ilic rcapiratory process is not a very active one; but
llie sills, which are of small size, being the only respiratory organ*,
nil the blood reiqulres to pass through them for purposes of aeration.
The heart here ts a single organ, destined only to drive the blood
(ram the terminution of the venoos oysLem to the capillariea of the
gills.

In reptiles, the heart Ih composed of two anriclee, placnl side by
side, and one ventricle. (Fig. 77.) The vemu cava discharge their

blood into the right auricle (a\
whence it passes into the ventricle
(c). From the ventricle, a part of it
is carried into the aorta and distri*
butcd throughout the body, while a
part is sent to the lungs through the
pulmonary artery. Thearterioli^ed
blood, returning from the lungs by
the pulmonary vein, is disohargeil
into the left auricle {b), and thence
finto the ventricle (c), where it
mingles with the venous blood
which has just arrived by the venB
cava.'. In the reptile, therefore, the
ventricle is a common organ of pro-
puUion, both for the lungs and for
the general circulation. In these
aniniaU the aeration of the blood lu
the lungs is only partial; a certain
portion of the blood which leaves
the heart being carried to these organs, just as in the human subject,
it is only a |)ortion of the b]oo<l which is i;arried to the kidney by
the renal artery. This orrangetnent is suHlcient for the reptiles,
because in many of theni, Huch as serpents and turtles, the lungs
are muuh more extensive and eflicient, as respiratory organs, than
the gills of fish; while in others, such as frogs and water-lizards,
the integument itJ^elf, whiuh is nmist, smooth, and naked, takes an
important share in the aeration of the bIoo<1.

In quadru)>eds and the human species, however, the respi-
ratory process is not only exceedingly active, but the luugs
are, at the same time, the only organs in which the aeration uf
the Wood can bo fully accomplished. In them, accordingly, we
find the two circulations, general and pulmonary, entirely dis-

Ci»''ct.«Tir>i« or KtrTii.ra —a.
R1|til •ortcln A. L(<n norkk e Vcain«lt.
4. iMBgi a. Aorl*- /, Vana Ckn.

THE HBART.

249

thict from each uLher. (Fig. 78.) All the blood returning from
tbe body by the veins must pa&a through the lungs before it is
ftgaiD distribated throagh the

arterial system. We have Plp' 78.

therefore a double circula-
tioD, and also a double henrt;
the two sides of whiuh,
though anited externally,
are acparatA internally. The
mammalian heart consists of
B right auricle and ventricle
(o, t), receiving the blood
from the venn cava (i), and
driving it to the lungs; and
a lefl auricle and ventricle
(/, y) receiving the bliKiil
from the lungs nnd driving
it outward through tbe Arte-
rial systeou

III the oomplete or double
mammalian hearty the difler-
ent parts of the organ present
certain peculiarities and bear

certain relations to each other, which it is necessary to understand
before we can properly appreciate ila action and movements. The
entire organ has a more or less conical form, its base being situntcd
on the median line, directed upward and backward; the whole being
suspended in the chest, and loosely fixed to the spinal column, by
the great vesaela which enter an<l leave it at this point. The apex,
on the contrary, is directed downward, forward, and to the left, sur-
munded by the pericardium and the pericardial fluid, butcnpuhlo
of a very free lateral and rotatory motion. The auricles, which
have a smaller capacity and thinner walla than the ventriules, are
situated at iho upper and pfisterior part of the organ (Figit. 79 and
80); while the ventricles occupy its anterior and lower portions.
The two ventricles, moreover, are not situated on the same plane,
but tbe right ventricle occupies a poeiition somewhat in front and
above that of the left; so that in an anterior view of the heart the
greater portion of the lefl ventricle is concealed by the ri'^ht (Fig.
79). and in a posterior view the greater portion of the right ven*
tricle is concealed by the lefl (Fig. 80); while in both petitions the

C[«ri'i.»T 111* 1 w M twit a Lr «i • — n. Rlchl
■urfrla. A, Rlflii triiirioU. «. PuliniifiMjr ulvrjr.
(t Lnnf*. t, Pulmvakry tfli. /. LafL karWI* f,
L«rt r«iilr1cl«. h Aurta t VoBarBTii.

THE HEART.

S61

pulmonary veins into the right and left auricles; the auriculo-
ventricular oriBces leailing from tlie auricles into the vcDtricles;
and the aortic and polmonary orifiaes lending from ibe ventricles
into the aortic and pulmonary arteries respectively.

The auricolo-ventriculnr. aortic and pulmonary orifices are fur-
niahed with valves, which allow the blood to pass readily from the
auricles to tbe ventrides, nod from the ventricles to the arteries,
bat shut back, with the contmcttons of the organ, so as to prevent
its return in an opposite direction. The course of the blood
through the heart w. therefore, »s follows. From the vena cava it
passes iolo the right auricle; and from the right auricle into the
right ventricle. (Fig. 81.) On the contraction of the right ventricle,
tbe tricuitpid valves shut back, provoiuiiig its return into the auricle
(Fig, 82); and it is thus driven through the pulmonary artery to the

rig. 83.

I'*tr AriretiB AN* VKITRieLA: Iwrkalo-TMtrleulir ValrM«h»*d. ArlfTtal rilr«* orcD.

iun^ Returning from the lungs, it enters the lefi auricle, theuce
pwes into the left ventriclo, from which it is finally delivered into
'lie aorta, and distributed throughout the body. (Fig. 83.) This
n>ovement of the blood, however, through the cardiac cavities, is
>ot a continuous and steady 6ow, but is accum))Iished by alternate
contractions and relaxations of the muscular parietcs of the heart;
M that with every i mpulse, successive portions of blood are received
bj tlifl auriclts, delivered into the ventricles, and by them dis-

262

THK CIRCULATION.

charged into the arteries. Each one of these successive avtionfi
called u beat, or pulsation of the heart.

Fi«. 63.

Corn*! nr Itinon TtiaiiriiH thh IlKiiiir. — «, h %aiia caia, •wiirrMir uid lal
t. Ktg)il ti-nirh^ln C PaltantiArj %tl*tj d I'ulmonarjr t*ib. c L*fl rgairtcle. /! Aorta.

Each pulsation of tho heart is accompanied by certain important
phenomena, which require to be studied in detail. These are tho
tounds, tho movements, and the impulse, ^

The sounds of the heart are two in number. They can readily be
heard by applying the ear over the cardiac region, when they are m
found to be quite diU'erent from each other in position, in tone, and V
in duration. They are distinguifibed aa the Jirst and «e<vri(/ Bounds
of ihe lieHrt. The first sound is heard with the gM^tcat intenRity
over the anterior surface of the heart, and more particularly over
the i^fth rib and tho Bflh intercostal Rpac«. It is long, dull, and
smothered in tone, and occupies otie<half the entire duration of ■
single beat. It corresponds in time with the impulse of the heart
in the precordial region, and the stroke of the large arteries in the
immediate vicinity of the chest. The second sound follows imme-
diately upon the first. It is beard most distinctly at the situation
of tho aortic and pulmonary valves, viz., over the sternum at the
level of the third costal cartilage. It is short, sharp, and distinct
in tone, and occupies only about one-qu.irtcr of the whole time of.

THE HEAKT. 253

t palntion. It ia followed by an equal interval of Bilence ; after
which the iirst sonnd again recurs. The whole time of a cardiac
palsfttion may then be divided into four quarters, of which the first
two are occupied by the first sound, the third by the second sound,
and the fourth by an interval of silence, as follows:—

Time of paluUon.

3d ** Second Boand.

4th " IntotTkl of silence.

The oauM of the second sound is universally acknowledged to be
the sadden dosnre and tension of the aortic and pulmonary valves.
This &ot is cBtmblished by the following proofs: 1st, this soand is
beard with perfect distinctness, as we have already mentioned,
directly over the aitnation of the above-mentioned valves; 2d, the
farther we reoede in any direction from this point, the fainter be-
oomes the sonnet; and 6d, in experiments upon the living animal,
(rfien repeated by different observers, it has been found that if a
cn'nred needle be introduced into Uie base of the large vessels, so
u to hook back the semilunar valves, the second sound at once dis-
appears, and remains absent nntil the valve is again liberated. These
valves consist of fibrous sheets, covered with a layer of endocardial
epithqliam. They have the form of semilunar festoons, the free
edge of which is directed away from the cavity of the ventricle,
while the attached edge is fiutened to the inner surface of the base
of the artery. While the blood is passing from the ventricle to the
artery, these valves are thrown forward and relaxed; but when the
artery reacts upon its contents they shut back, and their fibres, be*
coming suddenly tense, yield a clear, characteristic, snapping sound.
The production of the Jirst sound has been attributed by some
writers to a combination of various causes; such as the rush of
blood through the cardiac orifices, the muscular contraction of the
parietes of the heart, the tension of the aurioulo-ventricular valves,
the collision of the particles of blood with each other and with the
sar&oeof the ventricle, iic. &c. We believe, however, with Andry'
aad some others, that the first sound of the heart has a similar
origin with the second; and that it is dependent altogether on the
demre of the awicuh-ventricular valves. The reasons for this con-
tloaon are the following : —
lafc. The second sound is undoubtedly caused by the closure of

' DiMuee of the Heart, Kneeland'a translation, fioatoii, Ii^,

THE CIRCPI-ATrOH.

the semilunar valves, and in the action of iho heart the shutting
back of the two seta of valves allernale with each other precisely
U clo the first and second sounds; and there is every probability,
to say the least, tliat the sudden tension of the valvular fibres pro-
Juoea a similar effect in each instance.

2d. The &Tat sound is heard moat distinctly over the anteriorj
surface of the venlricles, where the tendinous cords supporting thel
Buriculo-ventriuutur valves are inserted, and where the sound pro-
duced by the tension of these valves would be most readily cod- _
dact«d to the ear. f

3d. There is no reason to believe that the cnrrent of blood
through the cardiac onlices could give rise to an appreciable sound,
so long as these onijcc»>r and the cavities to whiclt they lead, have
their normal dimensions. An unnatural souffle may indeed origi-
nate from this cause when the orifices of the heart arc dimioiahed
in size, as by calcareous or fibrinous deposits; and it may also
occur in cases of aneurism. A soufQo may even be produced aifl
will in any one of the large arturi^s by pressing lirtnly upon" it
with the end of a stethoscope, so as to diminish its calibre. But in
all these instances, the abnormal sound occurs only in consequence
of a disturbance in the natural relation existing between the volume
of the blood and the size of tlie orifice through which it oassee.
In the healthy heart, the different orifices of the organ arc in exact
proportion to the quantity of the circulating blood ; and there is no
more reason for believing that its paswage should give rise to a
sound in the cardiac cavities than in the larger arteries or veioa.

4th. The difl^erence in character between the two sounds of the
heart depends, in all probability, on the different arrangement of
the two sets of valves. The second sound is short, sharp, and dis-
tinct, because the semilunar valves are short and narrow, superficialfl
in their situation, and supported by the highly elastic, dense and
fibroua bases of ihc aortic and pulmonary arteries. The first sound
is dull and prolonged, because the auriculo-ventricular valves aral
broad and deep-seated, an<l arc attached, by their long chordjsj
tendineoe to the comparatively soU and yielding fleshy columns of
the heart. The diBbrence between the first and second sounds can,
in fact, be easily imitated, by simply snapping between the fingera
two pieces of tape or ribbon, of the same te.\ture but of different
lengths. (Fig. 64.) The short one will give out a distinct and sharp
sound; the long one a comparatively dull and prolonged sound.

Together with the first sound of the heart there is also to bo]

THE HEART. 265

lieard a slight /ric^i'on aovnd, produced by the collision of the point
of the heart against the parietes of the chest. This sound, which is
heard in the fiflh intercostal space, is very faint, and is more or less

Fig. 64.

nuked by the strong vaWular sound which occurs at the same
time. It is different, however, in character from the latter, and
may UBoally be distinguished from it by careful examination.

The movemmta of the heart during the time of a pulsation are
of m peculiar character, and have been very often erroneously
deaoribed. lu fact altogether the best description of the move
menta of the heart which has yet appeared, is that given by Wil-
liam Harvey, in his celebrated work on the Motion of the Heart and
Blood, published in 1628. He examined the motion of the heart
by opening the chest of the living animal ; and though the same or
■milar experiments have been frequently performed since his time,
tbe descriptions given by subsequent observers have been for the
most part singularly inferior to his, both in clearness and fidelity.
The method which we have adopted for examining the motions of
dte heart in the dog is as follows: The animal is first rendered
insensible by ether, or by the inoculation of woorara. The latter
mode is preferable, since a long-continued etherization seems to
exert a sensibly depressing effect on the heart's action, which is
not the case with woorara. The trachea is then exposed and
opened just below the larynx, and the nozzle of a bellows inserted
wd secured by ligature. Finally, the chest is opened on the me-
disn line, its two sides widely separated, so as to expose the heart
tnd lungs, the pericardium slit up and carefully cut away from its
attachments, and the lungs inflated by insufflation through the
trachea. By keeping up a steady artificial respiration, the move-

256

ments of the hcnrt may he matie to continue, in favorable cases,!
more than an hour: and its notions ma}' bo studied hy direct o\
viition, like those of any external organ.

The examination, however, requires to be conducted with ccrtaia
precautions, which are indispensable to success. When the heart
is first exposed, its movements are so complicated, and recur with
such rapidity, that it ia difficult to distinguish them perfectly from
each other, and to avoid a certain degree of confusion. Singular
ns it may seem, it is even dilTicnlt at first to determine what [wriixi
in the lieart's pulsation corresponds to cootraction, and what tafl
relaxation of the organ. We have even seen several medical men,
watching together the pulsations of the same heart, unable to agree
upon this point. It ia very evident, indeed, that several Knglish
and continental observers have mistaken, in their examinations, tbe^
contraction for the relaxation, and the relaxation for the contrao* ■
tioQ. The 6rst point, therefore, which it is necessary to decide, in
examining the aucceaaivo movements of a cardiac pulsation, ia thfr
following, vi?,: Which is the con(ractio7i and wkicfi Uu relaxation of
the venlriclfBT The method which we have adopted la to pass a
small silver caniila directly through the parietes of the left ven-
tricle into its cavity. The blood is then driven from the external
oriflcG of the canula in interrupted jets; each jet indicating the
time at which the ventricle contracts u[)on its contonta. The
canulfl is then withdrawn, and the different muscular layers of the
ventricular walla, crossing each other obliquely, dose the ofwning, ^
80 tliat there is little or no subsequent hemorrhage. f

When the successive actions of contraction and relaxation have
by this means been fairly recognized and distinguished from each
other, the cardiac pulsations are seen to be characterized by the
following phenomena. The changes in form and position of tbef
entire heart are mainly dependent on those of the ventricles, which
contract simultaneously with each other, and which constitute much
the largest portion of the entire mass of the organ. ■

1. At the time of its contraction the heart hardens. This pheno-
menon is exceedingly well marked, and ia easily appreciated by
placing the finger upon the ventricles, or by grasping them between m
the finger and thumb. The muscular fibres become swollen and
indurated, and, if grasped by the hand, communicate the sensation
of a somewhat sudden and powerful shock. It ia this forcible indu-
ration of the heart, at the time of contraction, which has been mis-
taken by some writers fur an active dilatation, and described

TUB HEART. 267

snch. It is, however, a pbenomenon precisely similar to that which
takes place in the cootraction of a voluntary muscle, which becomes
swollen and indurated at the same moment and in the same propor-
tion that it dimiDisbes in length.

2. At the time of contraction, the ventricles elongate and the
point of the heart protrudes. Tbis phenomenon was very well
described by Dr. Harvey.' "The heart," he says, "is erected, and
risea upward to a point, bo tbat at tbis time it strikes against the
breast and the pulse is felt externally." The elongation of the
ventricles daring contraction has, however, been frequently denied
by subsequent writers. The only modem observers, so far as we
are aware, who have recognized its existence, are Drs. C. W. Pen-
nock and £dward M. Moore, who performed a series of very careful
and interesting experiments on the action of the heart, in Philadel-
phia, in the year 1839.* These experimenters operated upon calves,
sheep, and horses, by stunning the animal with a blow upon the
bead, opening the chest, and keeping up artificial respiration. They
observed an elongation of the ventricle at the time of contraction,
and were even able to measure its extent by applying a shoemaker's
rule to the heart while in active motion. We are able to corroborate
entirely the statement of these observers by the result of our own
experiments on dogs, rabbits, frogs, &c. The ventricular contrac-
tion is on active movement, the relaxation entirely a passive one.
When contraction occurs and a stream of blood is thrown out of
the ventride, its sides approximate each other and its point elon-
gates; 80 that the transverse diameter of the heart is diminished,
and its longitudinal diameter increased. This can be readily felt
by grasping the base of the heart and the origin of the large vessels
gently between the first and middle fingers, and allowing the end
of the thumb of the same hand to rest lightly upon its apex.
With every contraction the thumb is sensibly lifted and separated
trom the fingers, by a somewhat forcible elevation of the point of
the heart

The same thing can be seen, and even measured by the eye,
in the following manner: If the heart of the frog or even of any
small warm-blooded animal, as the rabbit, be rapidly removed from
the chest, it will continue to beat for some minutes afterward ; and
when the rhythmical pulsations have finally ceased, contractions

■ Wnrki or William Harrer, H. D. Sjr/leTiham ed., Loudon, 1847, p. 21,

■ PhlUdvlpblk Medical Kztmltivr, Ko. 44.

258

THB CIBCULATIOIf.

can ftill be rea<^ily exviled by touching the heart with the point

the heart be now held by

the

A Steel neeille. II tbe t:eart tie now
thumb anJ finger, with its puint diretiteU upward, it will be seen
to have a pyramidal or conical form, representing very nearly in
its outline an equilateral triangle (Fig. t>5); it^ base, while in a
condition of rest, bulging out laleraJty, while the apex is compara-
tively obtuse.

a.vC'K^^

Pig. 85.

Fi|. 8S.

Ma^K* lit Fbo*
In a MM* vt NilaXk-
duB,

0tji«T or Pfto* la uameilMu

Vig. 87-

y^^ ^ ...When the heart, held in tins position, is touched with the point _
p.'^f a needle (Fig. Btl), it atarta up, becomes inatanily narrower and f
. . . longer, Ms sides approximating and its point rising to an acute
fT angle. This contraction is immediately followed by a relaxation;

rvL^^A. 1 the point of the heart sinks down, and its sides again bulge out-
ward. H
l^^l tX.^ i*«t us now see in what manner this change in the figure of the
a i\ f V vcTitrides during contraction is produced. If the muscular fibres

of the heart were arranged in the form of
simple loopa, running parallel with the
axis of the organ, the contraction of these
fibres would merely have the effect of di-
minishing the bv&u of the heart in every
direction. This effect can be seen in the
accompanying hypothetical diagram (Kig.
87), where the white outline represents J
8uch simple looped fibres in a state of re-
laxation, and the dotted internal line indi-
cates the form which ihey would take iafl
contraction. In point of fact, however,
. . , none of the muscular 6brea of the heart

IkVli^ K ' run parallel to its longitudinal axis. They are diapoeed, on the
contrary, in a direction partly spiral and partly circular. The inoai
tibrcs surt from the base of the ventriclea, am'

Diagram »l Si]ir[.B LuariD

Piaari, in tpUuiii.iii 1,1111 cii'

TBE HEART.

269

towftrd the apex, curling round the heart in Buch a manner ag to
pass over iU anterior surface in an obliquely spiral direction, from
above downward, and from right to left. (Fig. 88.) They converge

toward the point of the heart, curl*
**»• *8* ing round the centre of itsapei, and

then, changing their direclion, be-
come deep-seated, run upward along

Fig. 69.

Larr VaxraiabK or

Bci.L«eK'i H It ART, (bow.
1b| tta Jmji abrM.

the septum and internal surface of the ventricles, and terminate
in the oolutnnsB curnea:), and in the inner border of the auriculo-
ventricular ring. The deepest layers of fibres, on the contrary, ore
wrapped round the vcntriclc.<J in a nearly circular direction (Kig.
ts9); their pointn of origin and attachment being still the auriculo-
ventricutar ring, aud the points of the fleshy columns. The entn^
arrangement of the muscular bundles may be readily seen in a
heart which has been boiled for nx or eight bourn, ao as to soften
the oonnecting areolar tissue, and enable the 6bn^us layers to be
easily separated from each other.

By far the greater part of the mass of the fibres have therefore
a circular instead of a longitudinal direction. When they contmcty
their action tends to draw the lateral walls of the ventricles together,
and thus to diminish the transverse diameter of the heart; but as
each muscular fibre becomes thickened in direct proportion to ite
oontractioQ, their combined lateral swelling necessarily pushee out
iho apex of the ventricle, and the heart elongates at the same time
tbal its sides are drawn together. This effect is illustrated in the
accompanying diagram (Fig. 90), where tlie white lines show the
figure of the heart during relaxation, wilb the course of its circular

260

TBB CIECULATlOff.

Fig. 9(1.

til»|iiiiB ■•rriK<riAa Final*
ar THE lliAKT, &M ibeK «Mt-

fibres, while the dotted line shows the narrowed and dongated
figure necessarily produced by their coutraclion. This phenomeaun,

therefore, of tbe prutrusioa of the apex
of tbe heart at the time of contniciiciD, is
not only fully established by observaitoD.
but is readily explained by the anfttomical
structure of the orgsn.

3. Simultaneously with the hardeaiag
and elongation of the heart, its apex move
slightly from lef^ to right, nod rotales also
DpoD its own axis In tbe same directioa.
Both these moTements result from tbe
peculiar spiral arrangmnont of t^c cardiac
fibres. If we refer again to tbe preceding:
diagrams., we shall see that, provided the
fibres were arranged in eimplo loogituJi-
Tial loop9(Pig.87),theircontraction would
merely have the effect of drawing the point of the heart directly
upward in a straight line toward its base. On the other hand, if
they were arranged together in a circular direction (Fig. 90), tbe
apex would be simply protruded forward, also in a direct line,
without deviating or twisting either to tbe
right or to the left. But in point of Gut,
the superficial fibres, as we have already
described, run spindly, and curling round
ihe point of the heart, turn inward towanl
its base; so that if tbe apex of the organ be
viewed externally, it will be seen that tbe
super^cial fibres converge toward ita ceo-
tral point in curved lines, as in Fig. 91. It
13 well known that every curved tnuscalar
fibre, at tbe time of its shortening, necMU-
rity approximates more or less to • straigfat
line. Its curvature is diminished in exact proportion to the exteol
of its contraction; and if arranged in a spiral form, its coDtmctioa
tends in the same degree to untwist the spiral. During the con-
traction of the heart, therefore, its apex rotates on its own axis io
tbe direction indicated by the arrows in Fig, 91, vIk., from left I^H
right anteriorly, and from right to lell posteriorly. This prodatri^n
a twisting movement of the apex in the above direction, whteb la

Ffg. 91.

(' . . > r > ■ 11 I ■ u P I > K r • -if

lUK ArKxov ma IJiaiit,

TUX HEART. 261

▼ery perceptible to the eye at every pulsation of the heart, when
expoeed in the living animal.

4. The protrQBion of the point of the heart at the time of con-
traction, together with its rotation upon ita axis from left; to right,
brings the apex of the organ in contact with the parietes of the
chest, and produces the shock or impulse of the heart, which is
Teadily perceptible externally, both to the eye and to the touch.
In the human subject, when in an erect position, the heart strikes
the chest in the fiftib intercostal space, midway between the edge of
the sternum and a line drawn perpendicularly downward from the
left nipple. In a supine position of the body, the heart falls away
from the anterior parietes of the chest so much that the impolse may
disappear for the time altogether. This alternate recession and
advance of the point of the heart, in relaxation and contraction,
is provided for by the anatomical arrangement of the pericardium,
tod the existence of the pericardial fluid. As the heart plays back-
vard and forward, the pericardial fluid constantly follows its
movements, receding as the heart advances, and advancing as the
heart recedes. It fulflls, in this respect, the same purpose as the
BfDovial fluid, and the folds of adipose tissue in the cavity of the
Urge articalations; and allows the cardiac movements to take place
to their fall extent without disturbing or injuring in any way the
kdjacent organs.

6. The rhylhm of the heart's pulsations is peculiar and somewhat
complicated. Each pulsation is made up of a double series of con-
tractions and relaxations. The two auricles contract together, and
afterward the two ventricles; and in each case the contraction is
immediately followed by a relaxation. The auricular contraction
ia short and feeble, and occupies the first part of the time of a
pulsation. The ventricular contraction is longer and more powerful,
and occupies the latter part of the same period. Following the
Tentricular contraction there comes a short interval of repose, afWr
which the auricular contraction again recurs. The auricular and
Tentricnlar contractions, however, do not alternate so distinctly
vitb each other (like the strokes of the two pistons of a Are engine)
aa we should be led to believe from the accounts which have been
given by some observers. On the contrary, they are connected and
oontinaous. The contraction, which commences at the auricle, is
immediately propagated to the ventricle, and runs rapidly from the
(mm of the heart to its apex, very much in the manner of a jyeri-
italtic motion, except that it is more sudden and vigorous.

292

THE CIRCITLATION.

William Harvey, again, gives a bettor acconnt of thia part of i
hearths action than has been published by any subsequent writer.
Tbc following exceedingly graphic and appropriate deacriptton,
takea from his book, ahows that be derived bis koowlodgo, not '
from any secondary or hypothetical sources, but from direct and^
careful study of tbe phenomena in ibe living animal. H

"First of all," he says,' "the auricle contracts, and in the coarac '
of its contraction throws the blood (which it coutains in ample
quantity as the bead of the veius, the storehouse and cistern of Um
blood) into the ventricle, which being filled, the heart raises itself
straightway, makes all its ^bres tense, contracts the rentriclea, and
performs a beat, by which beat it immediately sends the bloody
supplied to it by the auricle, into the arteries; the right vcntricli
sending its charge into the lungs by the vessel which is called veosl
arteriosa, but which, in structure and function, and all things elw,
is an artery; the \e(l veutricle seodiug ita charge into tbe aorta, ^
and tliroUjL^h thia by the arteries to the body at large. ^

"These two motions, one of the ventricles, another of the auricles^"
take place consecutively, but in such a manner that there is a kind
of harmony or rhythm preserved between them, the two concurring
in such wise that bat one motion is apparent, especially in the
warmer blooded animals, in which the movements in question ars
rapid. Nor ia this for any other reason thao it is in a piece of
machinery, in which, though one wheel gives motion to another,
yet all the wheels seem to move simultaneously; or in thai
mechanical contrivauce which is adapted to Bre-arms, where the
trigger being touched, down comes the flint, strikes against tbe
steel, elicits a spark, which falling atnung the powder, it is ignited,
upon which the flame extends, enters the barrel, causes tbo explo-
sion, propels tbe ball, and the mark is attained ; all of which inci*
dents, by reason of the celerity with which they happen, seem to
take place in the twinkling of an eye."

The above description indicates precisely the manner in which
tbe contraction uf the ventricle follows successively and yet cod-
tinuoQsly upon that of the auricle. The entire action of the auricle
and veutricles during a pulsation is accordingly as follows: Tbe
contraction begins, as we have already stated, at the auricle.
Thence it runs immediately forward to the ajKix of the heart. The
entire ventricle contracts vigorously, its walls harden, its Bp«

■pp. oil., p. 31.

THI ABTBBIE8 AND THE ARTERIAL CIRCULATION. 263

protrudes, strikes against tbe walls of tbe ohest, and twists from
left to right, the anriculo-ventrioalar valves shut back, tbe first
aoand is produced, aad tbe blood is driven into the aorta and
polmonaiy artery. These pheuomena occupy about one-half the
time of an entire pulsation. Then the ventricle is immediately
relaxed, and a short period of repose ensues. During this period
tbe blood flows in a steady stream from the large veins into the
auricle, and through the auriculo-ventricular orifice into the ven-
tricle; filling tbe ventricle, by a kind of paraive dilatation, about
two-thirds or three-quarters full. Then the auricle contracts with a
quick sharp motion, forces the last drop of blood into tbe ventricle,
distending it to its full capacity, and then tbe ventricular contraction
fidlowB, aa above described, driving the blood into the large arteries.
These movements of contraction and relaxation continue to alter-
nate with each other, and form, by their recurrence, tbe successive
cardiac pulsations.

THE ABTKRIBS AND THE ARTERIAL CIRCULATION.

The arteries are a series of branching tubes which commence
with the aorta and ramify throughout the body, distributing tbe
blood to all tbe vascular organs. They are composed of three
Qoata, viz: an internal homogeneous tunic, continuous with the
mdocardium; a middle coat, composed of elastic and muscular
'fibnn; and an external or "cellular" coat, composed of condensed
layers of areolar tissue. The essential anatomical difference be-
tween the larger and the smaller arteries consists in the structure
of their middle coat In the smaller arteries this coat is composed
tacdnsively of smooth muscular fibres, arranged in a circular man-
ner around the vessel, like the circular fibres of the muscular coat
of the intestine. In arteries of medium size the middle coat con-
tuns both muscular and elastic fibres; while in those of the largest
odibre it conaists of elastic tissue alone. The large arteries, ac-
eordingly, possess a remarkable degree of elasticity and little or no
eoDtractility; while the smaller are contractile, and but little or not
It all elastic.

It is found, by measuring the diameters of the successive arte-
rial ramifications, that the combined area of alt tbe branches given
off from a tmnk is somewhat greater than that of the original
fsnal; and therefore that the combined area of all the small arte-
nesmust be considembly larger than that of tbe aorta, from which

THS CIRCULATION.

1
I

the arterial Bystem origtDates. As the bloo(], coDseqaentlj, ia its
passage from the heart outward, flowa sncccsfliveljr through larger
and larger spoces, the rapidity of its circulation roust necessarily
be diminished, in the same proportion as it recedes from the heart.
It ia driven rapidly through the larger trunkft, more slowly through
those of medium size, and more slowly alill as it approaches tho
termination of the arterial system and the commencement of the
capillaries.

The movemeni of tfie itfood through the arteries is primarily caused
by tho couinictionflof the heart; but is, at the same time, regulated
and modified by the elasticity of the ressels. The mode in which
the arterial circulation takes place is as follows. The arterial sys-
tem is, as we have seen, a vast and connected ramificatiou of tabular
canals, which may be regarded as a great vascular cavity, divided
and subdivided from within outward by the successive branching
of its vessels, but communicating freely with the heart and aorta
nt one extremity, and with the capillary plexus at the other;
and this vascular system is iilleii everywhere with the circulating
fluid. At the time of the heurt'a contraction, the muscular walla of _
the ventricle act powerfully upon its fluid contents. The auricolo- I
ventricular valves at the same time shutting back and preveating
the blood from regurgitating into the ventricle, it is forced out
through the aortic oriRce. A charge of blood is therefore driven
into the arterial ramifications, distending their walls by the addi-
tional quantity of fluid forced into their cavities. When the ven-
tricle immediately ailerward relaxes, the active distending force is
removed; and the elastic arterial walls, reacting upon their contenta,
would force the blood back again into the heart, were it not for the
semilunar valves, which shut together and close the aortic orifice.
The blood is therefore urged onward, under the pressure of the ■
arterial elasticity, into the capillary system. When the arteries
have thus again partially emptieil themselves, and returned to their
original dinionsiun^, they are again distended by another contraction
of the heart. In this manner a succession of impulses or distensions
arc produced, which alternate with the reaction or subsidence of ibe
vessels, and which £aa be felt throughout the body, wherever the
arterial ramifications penetrate. This phenomenon is known by
tho name of the arterial puhe.

When the blood is thus driven by the cardiac pulsations into the
arteries, the vesseU are not only distended laterally, but are olongate<l
08 well as widened, and enlarged iu every direction. Particularly

Tie. »2.

THS ARTBRtBS AXD TBB A.BTERTAL OIBOULATION. 265

when the vessel takes a curved or serpentine course, its elungatiou
nnd the increase of its curvatures may be observed at every pulsa-
tion. This may be seen, for example, in the temporal, or oven
in the radial arteries, in emaciated persons. It ia also very well
seen in the mesenteric arteries, when the abdomen is opened in the
living animal. At every contraction of the heart the curves of
the artery on each side become more strongly pronounced. (Fig.
92.) The vessel even rises op partially out of its
bed, particularly where it runs over a bony sur-
face, as in the case of tlie radial artery. In old
persons the curves of the vessels become perma-
nently enlarged from frequent distension; and all
the arteries tend to assume, with the advance of
age, a more serpentine and even spiral course.

But the arterial pulse has certain other pecu-
liarities which deserve a special notice. In the
first place, if we place one finger npon the chest
at the situation of the apex of the heart, and an-
other upon the carotid artery at the middle of
the neck, we can distinguish little or no diflerctice
)Q time between the two impulses. The diaten- EUn«.ti.jii nuj f«tt»-
■ioQ of the carotid seems to take place at the '»"»'•'> A«T»iii ix
aame mstant with the contraction ol the heart.
But if the second finger be placed upon the temjjoral artery, instead
of the carotid, there ia n perceptible interval between the two beats.
The impulse of the temporal artery is felt a little later than that of
the heart. In the same way the pulse of the radial artery at the
wrist saems a little later than that of the carotid, and Unit of the
posterior tibial at the nnklejointa little later than that of the radial.
So that, the greater the distance from the heart at which the artery
is examined, the later is the pulsation perceived by the Snger laid
upon the vessel.

But it has been conclusively shown, jmrticularly by the inverti-
gations of M. Marey,* that this diSerence in time of the attcrial
pulsations, in different parts of the body, is rather relative than
absolute. By the contraction of the heart, the impulse is commu-
nicated at the same instant to all parts of the arterial system; but
the apparent diftercncc between them, in this respect, depends upon
the fact, that, although all the arteries begin to be distended at the

■ Dr. Brmra-S^nard'a jAumat <1« niTnielngio. April, 1859.

THB CIBC^TLATIOH.

aamo moment, yet those nearest the heart are distended suddenly
and rnpidly, while for those at a distance, the distension takes place
more alowly and gradually. Tlius the impulse given to the finger,
which marka the cxindltion of maximum disteasioD of the vessel,
occurs a little later at a distance from the heart, than in immediate
proximity.

This modification of the arterial pulse is produced in the follow-
iog way : —

The contraction of the left ventricle is a brusque, vigorous and
sudden motion. The charge of blood, thus driven into the arterial
system, meeting with a certain amount of resistance from the fluid
already filling the vessels, does not instantly displace and force
onward a quantity of Uood equal to its own mass, but a large
proportioa of its force is used in expanding the distensible walls
of the vessels. In the immediate neighborhood, therefore, the
expansion of the arteries is sadden and momentary, like the con-
traction of the heart itself. But this expansion requires for its
completion a certain cxpetiditure, both of force and time; ao ihal
at a little distance farther on, the vessel will neither be distended
to the same degree nor with the same rapidity. At the more dis*
tant point, accordingly, tiie arterial impulse will be less powerful
and will arrive at its maximum more slowly.

On the other band, when the heart beuomcs relaxed, the artery
in its immediaco neighborboad contracts upon the blood by its own
elasticity; and as its contraction at this time meets with no other
resistance than that of the blood in the smaller vessels beyond, it
drives a. portion of its own blood into them, and thua supplies these
veaeels with a certain degree of diHteniling force even in the inter-
vals of the heart's action. Thus the difference in size of the carotid
artery, at the two perio<ls of the heart's contraction and its rclaxa^
tion, is very marked; for the degree of its distension is great when
the heart coutraots, and its own reaction aflerward empties it of
blood to a very considerable extent. But in the small bmnchca of
the radial or ulnar artery, there is less distension at the time of the
cardiac contraction, because thia force ha^t boon partly expended in
overcoming the elasticity of the larger vessels; and there is less
emptying of the vessel afterward, because it is atill kept partially
filled by the reaction of the aorta and its larger branches. In other
words, there is progressively less variation in 8i?:e, at the periods of
distension and collapse, for the smaller and distant arteries than for
those which are larger and nearer the heart.

FEBIES AlHl

n"Al&tERlAL CIBOULATION. 267

^f r, Marej bas illustrated these facta by ao exceedingly ingenious
and efleutualcoutrivaoce. He attached to the pipe uf a small forcing
pomp, to be worked by alteraate strokea of the piston, a long elastic
tube open at the farther extremity. At differeot points upon this
lube there rested little movable le^era, which were raised by tho
distension of the tube whenever water was driven into it by the
forcing pomp. Each lever carried upon its extremity a small pen-
cil, which marked upon a strip of paper, revolving with uniform
rapidity, the lines produced by its alternate elevation and depression.
By these currea, therefore, both the extent and rapidity of distension
of different parts of the clastic taho were accurately registered.
Jhe curves thus produced were as follows: —

Fig. 93.

Cvavivo' '■■ AiTBit«L PiIL*Atlos, at lltnatniMl hy U Umr'i «sp«rlMaBl,'-t. lt«u
Ifc* dUlADJIftf rwM, 1. Al ft dUUBM Itaoi IL 3. Still fltnli«t r*m&T«d.

It will be seen that the whole lime of pulsation is everywhere of
equal length, and that the distension everywhere begins at the same
moment. But at the beginning of the tube the expansion is wide
and ludden, and occupies only a sixth part of the entire pulsation,
while all the rest is taken up by a slow reacliou. At the more

€ole point*, however, the period of expansion becomes lunger
that of collapse shorter; until at 8 the two periods are com-
ely equali/.e<l, and the amount of expansion is at the same time
reduced oue-balf. Thus, the farther the blood passes from the heart
outward, the more uniform is its Bow, and the more moderate the
distensiun of the arteries.

Owing to the alternating contractions and relaxations of the heart,
accordingly, the blood posses through the arteries, not in a steady
stream, but iu a aeries of welling impulses; and the heraorrbaga
from a wounded artery is readily distinguished from venous or
capillary hemorrhage by the fact that the blood flows in successive

t^, as well OS more rapidly and abundantly. If a puncture be
ade in the walls of the ventricle, and a slender canuht introduces*

268

THB CIBCULATIOir.

the flow of the blood through it is seen to be entirely intflrmitlent.
A strong jet takes place at each ventricular contraction, and at each
rehutation the flow is completely inlerrui)ted. If the puncture he
made, however, in any of the large arteries near the heart, the 8ow
of blood through the orifice is no longer intermittent, but ia con-
tinuous; only it is very much stronger at the time of ventricular
contraction, and diminishes, though it does not entirely cease, at
the time of relaxation. If the blood were driven through a series
of perfectly rigid and unyielding tubes, its flow would be every-
where intermittent; and it would be delivered from an orifice situ-
ated at any point, in perfectly interrupted jets. But the arteries
are yielding and elastic; and this eliisticity, as we have already
explained, moderates the force of the separate arterial pulsations,
and gradually fuses them with each other. The interrupted or
pulsating character of the arterial current, therefore, which is
strongly pronounced in the immediate vicinity of the heart, becomes
gradually lost and equalized, during its passage through the vessels,
until in tbo smallest arteries it is nearly imperceptible.

The same etlect of an elastic medium in ecjualixing the force of
aa interrupted curront may be shown by fitting to the end of a
common syringe a long glass or metallic tube. Whatever be the
length of the inelastic tubing, the wnter which is thrown into one
extremity of it by the syringe will be delivered from the other end
in distinct jels, corresponding with the strokes of the piston ; but if
the metallic tube bo replaced by one of India rubber, of sufBcieot
length, the elasticity of this substance merges the farce of the sepa-
rate impulses into each other, and the water is driven out from the
farther extremity in a ccntiuuuus stream.

The elasticity of tlie arteries, however, never entirely equalizes
the force of the separate cardiac pulsations, since a pulsating cha-
racter can be seen in the flow of the blood through even the smallest
arteries, under the microscope; but this pulsating character dimi-
nishes very considerably from the heart outward, and the current
becomes much more continuous in the smaller vessels than in the
larger.

The primary cause, therefore, of the motion of the blood in the
arteries is the contraction of the ventricles, which, by driving out
the blood in interrupted impulses, distends at every stroke the
whole arterial system. But the arterial pulse is not exactly syn-
chronous everywhere with the beat of the heart; since a certain
amount of time is required to propagate the blood-wave from the

THE AATSRIES AKD THE ARmiAL CTItCri.ATTON. 269

centre of the circulation oatwftrd. The pulse of the radial »n«ry
at tbe wrist is perceptibly later than that of the heart; and the
pulse of the [wstcrior tibial at the ankle, again, porocptiblv later
than that at the wrist. The arterial ciroulation, acsordingly, is not
an entirely aimplo phenomenon; but is made np of the combined
effects of two different physical forces. In the first place, there is
the elasticity of the entire arterial system, by which the blood is
sabjected to a constant and uniform pressure, qoite independent of
the action of the heart. Secondly, ihure is the alternating contntc-
tioQ and relaxation of the heart, by which the blood is driven in
rapid and successive impulses from the centre of the circalation, to
be thence distributed throughout the body.

The passage of the blood ihrou>;h the arterial system takes place
under a certain degree of constant pressure. For these vessels being
everywhere elastic, and filled with blood, they ct^nstantly t«:nd to
react, more or less vigorously, nn-i to compress the circulating fluid
which they contain. If any one of the arteries, aocordlngly, be
opened in the living animal, and a glass tube inserted, the bIoo4i
will immediately be seen to rise in the tube to a height of about
five and a half or six feet, and will remain at that level; thus indi-
cating tbe pressure to which it was subjected in the interior of the
vessels. This constant pressure, wbicb is thus due to the reaction
of the entire arterial system, is known as the arterial preMure.

The degree of arterial pressure rnay be easily measured by con-
necting the open artery, by a flexible tube, with a small reservoir
of mercury, which is provided with a narrow upright glass tube,
open at its upper extremity. When the bltxid, therefore, urged by]
the reaction of the arterial walU, pre«ea upon the surface of the
mercury in the receiver, the mercury rises in the upright lube, to
a correspoudiug height. By the use of this instrument it is seen,'
in tbs first place, that the arterial pressure is nearly the same all
over the body. Since the cavity of the arterial system is every-
where oontinooos, the pressure must necessarily be communicated,
by the blood tn its interior, equally in all directions. Accordingly,
the constant pressure is the same, or nearly so, in the larger an J tb«
smaller arteries,, iu those nearest the heart, and those at a distance.
This constant pressure averages, in the higher quadrupeds, sixi
inches of mercury, which is equivalent to from five and a half to
>ix feet of blood.

It is also men, however, in employing such an instrument, that
the level of the mercury, in tbe upright tube, ia not perfectly steady,

270

THB CIRCULATIOW.

but rises and fslls with the pulsations of the henrt Thus, At ererj
contraction of the ventricle, the mercury risea for about half art
inch, an<i at every relaxation it falls to its previous leveL Thus the
instrument becomes a inemture, not only for the constant pressareof
the arteriefl, but also for the intermitting pressure of the heart; and
on that account it has received the name of the cardiometer. It ia
seen, accordingly, that each contraction of the heart ia superior in
foroe to the reaction of ihe arteries by about one-twelfth; and these
vessels are kept filled by a succession of cardiac pulsations, and
discharge their oonteuts ia tura into the capiUaries, by their
eliurtic reaction.

The rapidity with which the blood circulates through the artet
system is very great. Its velocity ia greatest in the immediate
Detghborbuod of the heart, and diminitihes somowhai as tiie blood
recedes farther and farther from the centre of the circulation. Tbii
diminution in the rapidity of the arterial current is duo to the aufr
cessive division of the aorta and its primary branches into amalldrj
aad Hmaller ramifications, by which the total calibre of the arlerid'
system, as we have already mentioned, is somewhat inoroased^ Thai
blood, therefore, flowing through a larger space as it passes oacwapJ,!
necessarily goes more slowly. At the same time the increased'
extent of the arterial parietes wiih which the blood cornea ia ooo>
tact, as well as the mechanical obstacle arising from the division of j
the vessels and the separation of the streams, undoubtedly oontii-
bute more or Ictis to retard the currents. The mechanical ubmdc,'
however, arising from the friction of the blood against the wmllaof j
the vessels, which would be very serious in the. case of water ortuaj
similar fluid flowing through glass or metallic tubes, has compaia*
tively little eflect on the rapidity of the arterial oiroulattoo. TUa
can readily be seen by microscopic examination of any tntnfiparefrt
and vascular tissue. The internal surface of the arteries is so sniooUi
and yielding, and the consistency of the circulating fluid so aeco*
rately adapted to that of the vessels which contain it, thai the
retarding eflecta of friction are reduced to a minimum, and the
blood in flowing through the vessels meets with the least posaitde
resistance.

It is owing to this fact that the arterial circulation, though some-
what slower toward the periphery than near the heart, yel retains
a very remarkable vuluuily throughout; and even iu arteries of tb«
minutest size it is so rapid that ihe shape of the blood-globules can-
not be distinguished in it on microscopic examination, but only i

THE ABTEBIB8 AND THE ARTBBIAL CIBCULATION. 271

niDgled current shooting forward with increased velocity al every
ardiac patsation. Volkmann, in Germany, has determined, by a
■ory ingenious contrivance, ihe velocity of the current of blood in
ome of the large sized arteries in dogs, horscii, and calves. The
nstrument vhich he employed (Fig. 94) coDsisted of a roelallio
yliuder (a), with a perfonitiun running from end to end, and cor-
wponding in size with the artery to be examined. The artery was
divided transversely, and its cardiac extremity fastened to the
>er end (6) of the instrument, while its peripheral extremity was

Kg. M.

Fig. M.

TfttiM*|i«'« lrr*aATVt Hrntuahagiha ra»l4llrorih«BrtarikI«lr«itUlloB.

ID ihe same manner to the lower end(e). The blood

>rding1y still kept on itfl usual course; only pasMng for a short

ince thnsugh the nrtificial lube (a), between the divided extremi-

IDfthearlery. The instrument, however, was provided, il» shown

|ihe aocompaitjring figures, with two transverse cylindrical plugs.

perforated; and arranged in such a manner, that when, at a

272

THE CIBCULATION.

given signal, tlio two plugs were suddenly turned in opposhal
direciiutis, the stream of blood wuuld be lurited uut of its course?
(Fig. 95), and made to traverse a long bcDt Lube of glass {d^d, d},.
before again finding its way buck to the lower portion of the anerr. :
In tbis way t!ie diatauce passed over by the blood in a given time
oould be readily measured upon a scale attaubed to the side of the
glass tube, Volkmann found, as the average result of his obser-
vations, that the blood moves in the carotid arteries of warm-blouded
qoadrupuds with a velocity of 12 inches per second.

VENOUS CIRCULATIOIf.

The veins, which collect the blood from the tisanes and return tt
Co the heart, are composed, like the arteries, of three coats; an inner,
middle, and exterior. In structure, they differ from the arteries in
containing a much smaller qu&niity uf muiycular and clastic fibres,
and a larger proportion of simple condensed areolar tissue. They
are consequently more flaccid and comprciutiblc than the anerteia,
and less elnalic nnd contractile. Tiiey are furthermore distin-
guished, throughout the limbs, neck, and external portioDS of the
head and trunk, by being provided with valves, consistingurBbrous
she^ta arranged in the form of festoons, nnd so placed in the cavity
of the vein as to allow the blood to pas.^ readily from the periphery
toward the heart, while tbey prevent altogether its reflux in an
opposite direction.

Although the veins nre provided with walls which are very inach
thinner und less elastic than those of the arteries, yet, contrary to
what wc might expect, their capacity for resiiiance to pressure ift
equal, or even superior, to that of the arterial tubes. Mllno Kd'
wards' has coUoiuttid the results of various experiments, whieh show
that iho veins will sometimes resist a pressure which is sufficient lo
rupture the walla of the arteries. In one inst-inco the jugular vein
8upporte<l, without breaking, a pressure equal lo a column of water
im feet in height; and in another, the ili&u vein of a sheep resisted
a pressure of more than four atmospheres. The portal vein was
found capable of resisting a pressure of six atmospherea; and in
one case, in which the aorta of a sheep was ruptured by a pressure
of 158 pounds, the vena cava of the same animal supported a pren*
BurO'equa] to 176 [wunda.

■ Lacuna sur la I'hjr>ioloK[«, &n,, toI- It. p. 301.

TBMOOS CIRCt'LATlOS.

273

This reaisuince of the veins is to be attributed to tlio Inr^o pro-
portion of white fibrous tissae whteh enters into their composition ;
tho same tissue whit-h forma nearly ihu whole of the tendon a nml
fa-sciffi, aod which is Uistiuguished by its density and unyielding
nature.

The eUutteitt/ of the veins, however, ts much le^a ihnn thai of the
arteries. When they are filled with blmul, ihey enlarge to a certain
itixe, and cullape« again when the pressure is taken oft'; but they do
not react by virtue of an elastic resilienoe, or, at least, only in a
slight extent, as compared wiih the arteries. Aucordingly, when
the arteries are out across, as we know, and emptied of blood, They
still remain open and pervious, retaining the tubular form, on ac-
count of the elaxticity of their walls; while, if tbu veins bu irvuted
in the same way, their sides simply fall together and remain in con-
tact wiih each other.

Another peculiarity of the venous system is the afmti'hnre of
the sejtarale thaimels. which it aQords, for the 6ow uf L>lood from
the periphery towards the centre. I'he arteries pass directly from
the heart outwant, each separate branch, as a general rule, going
to a separate region, and supplying that part of the body wiih
ftll the bloiNl which it re«iuires; so that the arterial system is kept
oonsUintly filled to its entire capacity with the blood which passes
through it. But that is not the case with the veins. In injeclet)
preparations t>f the vascular system, we have often two, three,
four, or even five veins, coming together from the snme region of"
the body. Tlicre »re also abundant Inosculations between the ilif-
ferent reins. The deep veins which accompany the brachial artery
inosculate freely with onch other, and u\wi with the superficial veins
of the arm. ]u the veins coming from the head, we have the ex-
ternal jugular comiiii)ni(.-ating witti the thyroid veins, the anterior
jugular, and the brachial veins. The external Bud internal jugulars
communicate with each other, and the two thyroid veins also form
ao abundant plexus in front of the trachea.

Thus the blood, coming from the extremities toward the heart,
flows, not in a single channel, but in many channels; and as the^
vhanuels commuuicale freely with eucli other, the blood passes some*
times through one of them, and sometimes through another.

The flow of bloixl through the veins is less powerful ami rogalar
than that through the arteries. It depends ou the oombiue^l autU
uf ibrev diflervDt forces.
14

274

THE CIRCCLATION.

1. Thtfmrx of aspiration of the thorax. — When the chest exjKtndis

by the lifting of tlio rilw and the (keoent of the diaphragfn, its
movement, of course, tends to dimintsb the pressure exerted upon
its content^ and no has the effect of drawing into the thoracic cavity
nil tlie fluids which cnn gain acces8 Ut it. The expanded cavity is
prititipallj 6lled by the air, which passes in through the tmchea
and fills the bronchial tubes and pulmonary vesicles. But the
bIcKxl in the veins is also drawn into the chest at the same time and
by the same force. This force of aspiration, exerted by the ex[>an-
sion of the chest, is gentle and unlfurm in character, like the move-
menta of respiration tht^mselves. Accordingly itH influence is ex*
tended, without doubt, to the farthest extremities of the venous
tiyHteiii, the blood being gently solicited toward the heart, at each
expansion of the chest, without any visible alteration in the size of
the veins, which are titled up from behind as fast aa they are emptied
in front.

But if the movement of inspimtion be sudden and violent, instead
of gentle and ea8y,a diflFerenteffect is produced. For then the walla
of the vt^im^ which are thin and lluccid, cannot retain their position,
but collapse under the external pressure too rapidly to allow ibi
biciud U) flow in from behind. In this vase, tfaenifuro, the vein ts
simply emptied in the immediate neighborhood of the chesty bat
ihe entire venous circulation is not assisted by the movement.

The same difference in the effect of an easy and a V^iolent suction
movement, may bo readily shown by attAohing to the nozzle of an
nir-tight syringe a flexible elastic tube with thin walU, and placing
the other extremity of the tul>e under water. If the piston of the
i^yringo be now withdrawn with a gentle and gradual motion, the
water will be readily drawn up into the tube, while the tabe itself
suflers no visible change; but if the suction movement be made
rapid and violent, the tube will collapse instantly under the pres-
sure of (he air, and will fail to draw the water into its cavity.

A similar effect shows itaelf in the living boi^y. If the jugular
or siiltuiavinn vein be exposed in a dog or cat, it will be aeea that
while the movements of respiration are natural and easy no fluc-
tuation ill the vein can be perceived. But as soon aa the respira-
tion becomes disturbed and tairartous, then at each inspiration the
vein is collapsed and emptied; while during expiration, the chest
being strongly compressed and the inwartl Sow of the blootl arreeted,
the vein becomes turgid with blooil whiuh accumulates in it from
behind. In young vhildren, also, the spasmodic raovements uf res-

TEX^OUS CIRCl-LATtON.

275

pintion in crying prtvluce a similar tnrgescence and enj^orgoment
of tlie large rein» during expiration, while iliey nre momentarily
etiiptied (luring ihe hurried and forcible inspiration.

In notural and quiet respiration, therefore, the movements of the
chest hasten tind aasm the venous circulation; but in forced or
laborious respiration, ihey do not assist and may even retanl its flow.

2. The contradion of the vohintary rm'scles. — The veins wbich
eoQvey the blood through the liinba, and the parielcs of the head
and trunk, lie among voluniJiry muacles, which are more or less
constantly in a state of alternate contraction and relaxation. At
b every contraction these muscles become swollen latendly, and, of
coarse, compress the veins whieh nrc situated between them. The
bloo{l, driven out from the vein by this pressure, cannot regurgitate
toward the capillaries, owing to the vulvcs, already described, which
shut bock and prevent its reflux. It is accordingly forced onward
towaitl the heart; and when the muscle relaxes and the vein is
Liberated from pressure, it again fills up from behind, and the cir.
eulation goes on as before. This force is a very elTicieot one In
producing the venous circulation ; since the voluntary muscles are
more or less active in every -position of the IkkIv, and tlie veins
cunstanily liable to be compressed by them. It is on this nccouot

Fig.se.

Fig. VJ.

V«t« with vaIvw Djwa.

bl.iuil |)AHlng nil \ij ■ Uinrml cbuDnal

that the veins, in the external parts of the body, communicate sn
freely with each other by transverse brnnches; in order that the
eorrent of blood, which is momentarily excluded from one vein by

276

THE CITlCUtATIOX,

the pressure of the muscles, mtiy readily And a passage througli
otliers, whiuh communicate by cross branches witb ihe first. (Figs.
96 and 97.)

8. The /oree nf the capillary cirettia/ion. —Th'^s last cause oT tba ■
motion of tlie blood thrniigh ihe veins is the most important of all,
1)8 it is the only oue wbicti is uoiiataiitly and uutversally active. In _
fish, for example, reupiratioti is performed alto^'clher by gilla; and f
in reptiles the air is furce<l down into the lungs by a kind of deglu*
litioii, injitciid of being drawn in by the expansion of the chest. In. h
neiltier of these classes, therefore, can the movements of respiration 9
assist meehanicoliy in the uiroulation of the blood. In the splsneh-
nic cavities, again, of all the vertebrate animnls, the veins coming ■
from the internal organii, an, for example, the cerebral, pulmonaryi v
portal, hepatic, and renal veins, are unprovided with valves; and
the pns&aye of the blood through them cannot therefore be effected
by any luieral prc&iure. Tlie circulation, however, constantly going
on in the capillaries, everywhere tends to crowd the rsdiules of the
veins with blood; and this visa lergo, or pressure from behind, fills
the whole venous system by a constant and steady accumulation.
So long, therefore, aa the veins are relieved of blood at their cardiac
extremity by the regular pulsations of the bean, there is no back*
ward pressure to oppose the impulse derived from the capillary cir
eulation; and the movement of the blood through the veins continuea
in a fitciidy and unifiirm course. ■

With regHrd to the rapiditi/ of the venous circuhtioii, do direct
rcHtilta have been obtained by cxpfirimonL, Owing to the flaccidity
of the venous purietes, and the readiness with which the flow offl
bloo'l through them is difilurbcd, it is not possible to determine this
point for the veins, in the same manner as it has been determined
for the arteries. The only calculation which has been made in thia
respect U based upon a coinjiartson of the total capacity of the
nrterinl and venous systems. As the same blood which passes out-
vf&rd through the arteries, passes inward again through the veins,
the rapidity of its flow in each must be in inverse proportion to the
capacity of the two sets of vessels. That is to t^y, a quantity of
blood which would pasji in a given time, with a velocity of x,
through un opening ec^ual to one square inch, would pass during
ihe same time through an opening equal to two square inches, with
ii velocity of j; and would recjuire, on the other hand, a velocity
of 2 X, to pass in the same time through an opening equal to one-
half a square inch. Now the cupneity of the entire venous system^

THB CAPILLaRT CIRCULATION.

277

THE CAPILLABT CIRCULATION.

when distended by injection, is about twice as grent as that of the
entire arterial system. During life, however, the venous system is
at no time ao completely filled with blood as is the case with the
arteries; and, making allowance for thu difference, wc find tliat thu
entire quantity of venous blood is to the entire quantity of arterial
blood nearly as three to two. The velocity of the venous blood,
as compared with that of the arterial, is therefore as two to three;
or about 8 inches per second. It will be tiiiderstood, however, that
this calculation is altogether approximative, and not esnct; since
the venous current varies, according to many diffcront circumstances,
io different parts of the body; being slower near the cnpilluriea,
and more rapid near the heart. It expresses, however, with suffi-
cient accuracy, the relative velocity of the arterial and venous cur-
rents, at corresponding parta of their course.

■ The capillary bloodveasela are mjimte inosculating tubes, which

■ permeate the vascular organs in every direction, ami bring the
bloud into intimate contact with the substance of the tissuea. They
an continuous with the terminal ramiUcations of the arteries on
the one hand, and with the com-
mencing rootlets of the veins on
the other. They vary somewhat
in aize in different orgnna, and in
different species of animals; their
average diameter in the human
aabject being a tittle over , q'q J^ of
an inch. They are composetl of
a single, transparent, homogene-
ous, somewhat elastic, tubular
membrane, which is provided at
varioufl intervals with fattened,
oval nuclei. As the smaller arte-
lies approach the capillaries, they
dininiab constantly in size by
Boeeeasive subdivision, and lose
first their external or fibrous
tunic. They are then composed

only (if the internal or homogeneous cont, and the middle or muscu-
lar. (Fig. 98, a.) The middle coat then diminishes in thicknea",

FIf. 98.

lii>brMkln( ap iDlprapIUartw. tnm lhaj>Ai
mattr.

278

TRIE 01ROVT.ATIOX.

until it is reiluced to a single layer of circular, fusiform, nnstriped,
tnuiKuIar fibres, which in their tura disappear altogether, ss the
urtury inurgus at laat in the capillurius; leaving unly, as we have
Qlready mentiuned, a simple, homogcneoas, nacleatud, tubular mem*
branc, which is continuous with the internal arterial tunic.

The capillaries are further distitiguitiheJ from both arteries and
veins by their frequent inosculjiiion. The arteries constantly
divide And subdivide, as they pasd from within outward; while
the veins as constantly unite with each other to form larger and
less numerous branches and trunks, as they pass from the circum*
fenfnce toward the centre. But the capillaries simply inosculate
with each otlicr in every diroction, in such a manner as to form an
interlacing network or plexus, the eapiUary plertu (Kig. 99), which
i* exceedingly rich and abundant in some organs, less so in others.
'i'he spaces included between the meshes of the capillary network
vary ul.so, in shiipe as well as in size, in diHi^rent parts of the body.

In the muKCular i).4<)U6 thej
^'8- ■"*■ form long paiallel'»graina; in

the areolar tissue, irregular
shapeless figures, corrBS[>ond*
ing with the direction of the
6brous bundles of which the
tissue is composed. In the
mucous membrane of the
large intestine, the copillnrioa
include hexagonal or nearly
circular spaces, Inclosing the
oriGces of the fullicle^ii. In
the papillieof the tongue and
of the skin, and in the tufts
of the placenta, they are
arranged In long spiral loops,
and in the adipose tissue in wide meshes, among which the fat
vesicles are entangled.

The motivn of (he Hood in the cfptllariei mny be studied by
examining under the microscope any Lranspai~eiil tiscme, of a
sufficient degree of vascularity. One of the most convenient parts
for this purpose is the web of the frog's foot When properly
))repured and kept moistened by the occasional addition of water
to the integument, the clrculntiou will go on in its vessels for an
indefinite length of time. The blood can be seen entering the

CAriLtlKT BvvwoKX DruB wabarrnj'* fiHif.

THB CAPILLaST CIRCL'LATIoy.

279

field by ibe. smaller orteriea, shooting along through tbem vitb
great rapidity and in successive itnpulses, and flowing off again by
tbe veins at a somewhat sluvrer rate. In the capillaries themselves
tbc circulation is considerably less rapid than ia either the arteries
or the veins. It is also perfectly atendy and uninterrupted in its
Dow. The blood passes along in a unit'orm and continuous cnrrent,
without any apparent coniracliou or diluuitiou of tbe vessels, yery
mach as if it were Sowing

. , , , A Fl«. 100.

through glass tubes. An-
other very remarkable pe-
culiarity of the capillary
circulation is that it has no
definite direction. The nu-
merouij streams of which it
is composed (l''ig. lOO) do
not tend to the right or to
the left, nor towar^l any one
pBtticuJur jwint. On the
contrary, they pass above
nnd below each other, ai
right angles to each otber^s
course, or even in opposite
ilircctions; ao that the blood,
while in the caplHaries, merely circtilates promiscuously among
the lissu&t, in such a manner as to come ioliniately iu contact with
every part of tbeir substance.

The motion of the white and r&\ globules in the circulating blood
is also peculiar, and shows very distinctly the diflercnco in their
consistency nnd other physical properties. In the larger vessels
the rod globules are carried along in a dense column, in the central
psrt of the stream; while near the edges of the vessel there is ii
trans|uirent space occupiad only by the clear plasma of the blood,
in which no red globules are to be seen. In iho smaller vcssetn,
the globules pass along in a narrower column, two by two, ur
following each other in single file. The nu.\ibility and serai-tluid
consistency of these gh^bulcs arc here very apparent, from the
readincas with which they become folded up, bent ur twisted in
taming comers, and the ease with which they glide through minute
branches of communication, smaller in diameter than themselves.
Tbe white globules, on the other hand, flow more slowly und with
greater difficulty through the vessels. They drag along the exteir-

CAFILtAKT ClBCVL«TI«l Ik W«k Of fttg** IML

S80

THE CIRCUtjATlOS.

nal portions of llie current, and are sometimes momentarily arrests
Bppnreiitly adhering for a few seconds u> the intertint surfaoe of the
vessel. Whenever the current is obstructed or retarded in any
manner, t^e white globules accumukte in the affected portion, and
become more numerous there in proportion to the red.

It IB during the capillnry circulation that the blood serves for
the nutrition of the vascular organs. Its fluid poniona slowly
transude through the walU of the vcmcIs, and are absorbed by the
tissues in such proportion as is requisite for their nourishmeot.
The saline subslAuces enter at once into the composition of the
surrounding parts, generally without undergoing any change. The
phosphate of lime, for example, is taken up in large quantity by
the bones and cartilages, and in smaller quantity by the softer parts ;
while the chlorides of sodium and potasnium, the carbonates, sul-
phates, kc^ are appropriated in special proportions by the diflerent
tissues, according to the quantity necessary for their organizstioQ.
The albuminous ingredients of the blood, on the other hand, are
not only absorbed in a similar manner by the animal tissues, but at
the same time are transformed by catalysis, and converted into new
materials, characteristic of the different tissues. In this way are
produced the musculine of the muscles, the osteioe of the bones, the
<^a^tilagine of the cartilages, &.G. &.c. It is probable that this tmus-
formation docs not take place in the interior of the vessels them-
selves; but that the organic ingredients of the blood are absorbeil
by the tissues, and at the same moment converted into new mate-
rials, by contact with their substance. The blood in this way fur-
nishes, directly or indirectly, all the materials necessary for the
nutrition of the body.

The physical condiiioDs which influence the movement of the
bl'(K)d in the capillaries, are somewhat dilTerent from those which
regulate the arterial and venoua circulations. Wo must remember
that as the arteries jiassfrom tlie heart outward they subdivide and
ramify to such an extent th.it the surface 0>f the arterial walls js
very much increased, in proportion to the quantity of blood which
they contain. It is on this account that the arterial pulsation is ^u
much equal)7.ed at a distance from the heart, since the inHuence of
the elasticity of the arterial coats is thus conataiitiy increased ft-oni
within outward. But as these vessels finally reach the conlinea of
the arterial system, having already been very much increjtsed in
number and dirnintiiljed in si^&e, they then suddenly brt-ak up into

THE CAPTLtAHY OIROULATIOS.

281

B terminal ramificitioti of still smaller and more numerous vessels,
and BO lose themselves at last in the capillnry network.

B; this 6n!il increase of the vasoular surface, the equalization of
the beartV action is oompleted. There is no longer any intermitting
or pulsatile character in the force which acts upon the circulating
fluid; and the blood, accordingly, ia delivered from ilio arteries
into the capillaries under a perfectly continuous and uniform pres-
sure.

This pressure is suflicieat to cause thft blood to pass with coa-
giderable rapidity, through the capillary plexus, into the commence-
ment of the veins. Thin fact was first demonstrated by Prof.
Sbarpey,' of London, who employed an injecting syringe with a
double nozzle, one extremity of which was connected with a mercu-
rial gauge, while the other was inserted into the artery of a recently
killed animal. When the syringe, filled with defibrinated blood,
was fixed in this position and the vessels of the animal injected, the
defibrinated blood would press with equal force npon the mercury
in the gauge and upon the 6uid in the blood vessels; and thus it
was easy to ascertain the exact amount of pressure required to force
the defibrinated blood through the capillaries of the animal, and to
make it return by the corresponding vein. In this way I*rof.
Sharpey found that when the free end of the injecting tube was
attached to the mesenteric artery of the dog, a pressure of 90 milli-
metres of mercury cuused the blood to pass through the capillaries
of the intestine and of the liver; and that under a pressure of 130
millimetres, it flowed in a full stream from the divided, extremity
of the vena cava.

We have also performed a similar experiment on the vessels of
the lower extremity. A full grown healthy dog was killed, and
the lower extremity immediately injected with defibrinated blood,
by the femoral artery, iu order to prevent coagulation in the smaller
vessels. A syringe with a double flexible nozzle was then filled
with defibrinated blood, and one extremity of its injecting tube
attached to the femora) artery, the other to the mouthpiece of a
cardiometcr. By making the injections, it was then found that the
defibrinated blood ran from the femoral vein in a continuous stream
under a pressure of 120 millimetres, and that it wosdisuharged very
freely under a preasure of 180 millitncLrcs.

Since, as we have already seen, the arieriat pressure upon the

' Tmlil anil Uowtuin, rii^iiu!<i^iciil .^nAlnuiy and rii>«i><it<>^ uf Man, rol. ii, p.

S&o.

282

rBE CIBCULATIOX.

blood 18 equal to six inches, or 160 millimetres, of mercury, it ifl
evident tliat this pressure is sufficient to propel the blood tbrougli
tbo capillary circulation.

Beside, the bluod is not alto^ther relieved from the influence of
elasticity, afler it has left the arteries. For the cajilllaries them-
selves are elastic, notwithstanding the delicate texture of tbeir
walls; aod even tfae tissues of the organs which they travene
possess^ in many instoDcea, a considerable share of elasticity, owing
to the iDtnute elastic dbres which are scattered through their aub-
stance. These elastic fibres are found in considerable quantity io
the lungs, the spleen, the skin, the lubulat«d glands, and mure or
less in the mucous membranes. They are abundant, of course, in
the fibrous tissues of the extremities, in the faiscias, the tendons, and
the intermuscular substance.

In the experiment of injecting the ves?«cls of the lower extremity
with dcEibrinatcd blood, it' the injection be stopped, tho blood does
not instantly cease flowing from the extremity of the femoral vein,
but continues for a short time, until the elasticity of the intervening
parts is exhausted.

The same thing may be observed even in the Uver. If the end
of a water-pipe be inserted into the portal vein, tind the liver in-
jected with water un<ler the pressure of a hydrant, the liquid will
distend the vessels of the organ, and pass out by the hepatic veins.
Bat if the portal vein be suddenly tied or compressed, so as to shut
ofl" the pre:ssurc from behiud, the stream will continue to run, for
several seconds afterward, from the hepatic vein, owing to the re-
action of the organ itself u[>oii tho iluid contained in its vessels.

As a general rule, also, the capillaries do not suffer any backward
preftsure from the venous system. On the contrary, as wjon as the
blood has been delivered into the veins, it is hurried onward toward
the heart by the compression of the muscles and the action of the
venous valves. 'The right side of Llie heart iLscIf continuet! the same
process, by its regular contractions, and by the action of ila own
valvular apparatus; so thai the blood is constantly lifted away from
llic capillaries, by the muscular action of the surrounding parts.

These are the most important of the mechanical influences under
which the blood moves through the continuous round of the circu-
lation. The heart, by its alternating contractiona aud relaxations,
and by the backward play of its valves, continually urges the blood
forward into the arterial system. The arteries, by their dilatable
and elastic walls, convert the cardiac pulsations into a uniform and

THE CAPILLARY CIUCULATIOX. 28S

Steady pressure. Under this pressure, the blood passes through the
capillary vessels; and it is then carried backward to the heart
through the veins, assisted by the action of the muscles ami the
respiratory movements of the chest

At the same time there are certain phenomena which are very
important in this respect, and which show that various local in-
fluences will either excite or retard the capillary circulation in par-
ticular parts, independently of the heart's action. The pallor or
suffusion of the face under mental emotion, the congestion of the
mucous membranes during the digestive process, the local and de-
fined redness produced in the skin by an irritating application, are
all instances of this sort. These phenomena are usually explained
by the contraction or dilatation of the smaller arteries immediately
supplying the part with blood, under tbe influence of nervous
action. As we know that the smaller arteries are in fact provided
with organic muscular fibres, this may undoubtedly have something
to do with the local variations of the capillary circulation; but the
precise manner in which these Lftects are produced is at present
unknown.

The rajmfity oi the circulation in the capillary vessels is much
less than in the arteries or the veins. It may be measured, with a
tolerable approach to accuracy, during the microscopic examination
of transparent and vascular tissues, as, for example, the web of the
Trog's foot, or the mesentery of the rat Tbe results obtained in
this way by difTerent observers (Valentine, Weber, Volkmann, &c.)
show that the rate of movement of the blood through the capil-
laries is rather less than one-thirtieih of an inch per second; or not
quite two inches per minute. Since the rapidity of the current, as
we have mentioned above, must be in inverse ratio to the entire
i-alibre of the vessels through which it moves, it follows that the
united calibre of all the capillaries of the body must be from 350 to
400 times greater than that of the arteries. It must not be sHp-
jKMed from this, however, that tbe whole quantity of blood contained
ill the capillaries at any one time is so much greater than that in
the arteries; since, although the united calibre of the capillaries is
very large, their length is very small. The effect of the anatomical
Htructure of the capillary system is, tberefore, merely to disseminate
u comparatively small quantity of blood over a very large space, so
that the chemicu-phyaiological reactions, necessary to nutrition, may
take place with promptitude and energy. Fur the same reason,
iilthuugh the rate of movement uf the blood in these vesciela is very

284

THI OIRCDLATIOir.

slow, yet as the distance to be passed over between the arteries nn^
veins is very small, the blood really requires but a short time to
traverse the capillary system, and to commence its returning passage
by the veins.

OBNBRAI, COSSIDEl^ATIOXS.

The rapidity with which the blood passes through the entire round
nf the circulation is a point of great interest, and one wbiuh has
received a considemble share of attention. The results of such
experiment's, as have been tried, show that this rapidity is much
greater than would have been anticipated. Bering, Poisseuille, and
Matteucci,* have all experimented on this subject in the following
manner. A solution of fcrrocyanide of potassium was injected
into the right jugular vein of a horse, at the same time that a liga-
ture was placed upon the corresponding vein on the left side, and
an opening made in It above the ligature. The blood Bowing from
the left jugular vein was then received in separate vessels, which
were changed every five seconds, and the contents afterward exa-
minutl. It was thus found that the blood drawn from the first to
the twentieth second contained no traces of the ferrocyanide; but
that which escaped from the vein at the end of from twenty to
twenty-five seconds, showed unmistnltnble evidence of the presence
of the foreign salt. The ferrocyanide of potassium must, therefore,
during this time, have passed from the point of injection to the
right side of the heart, thence to the lungs and through the pulmo-
nary circulation, returned to the heart, passed out again through
the arteries to the capillary system of the head and neck, and
thonce have commenced its returning passage to the right side of
the heart, through the jngulnr vein.

By extending thei^e investigations to different animals, it was
found that the duration of the circulatory movement varied, to
some extent, with the size and species. In the larger quadrupeds,
as a general rule, it was longer; in the smaller, the lime required
was less.

In tb« Horse,* tlin mean dtiration wu SS Moonda.

■' Dog ' ' 16 ■■

" Omil " " " " 13 •'

•• ¥hx " >i u u iij <•

" Rabbil " " " .. 7 "

' I'll viIor] Phmoiniiiiii or Livitii; n«)ngR, I'Mvln's trttiHlalion, Philmla. mI., 1MB,
!>. 317.

' Id Milou E<Ivar<ta, Logons sur Ia I'lijaiologlt^, Ae., fal. ir. p. 3(I4.

I
I

LOCAL TXKTATIOSS.

286

When these results were Arst publislied, it was thought to be
doubtful whether the circulation were really as rapid as they would
make it appear. It vra« thought that the saline matter which was
iojevted, "travelled faster than the blood;" that it became "diftused"
through the circulating fluid; that it transuded through dividing
membranes; or parsed round to the point at which it was detected,
by some short and irregular route.

But none of these explanationa have ever been found to be cor-
'rect. They are all really more improbable than the fact which
they are intended to explain. The physical diffusion of liquids
does not take place with such rapidity as that manifestaied by the
circulation; and there is no other rouUs so likely to give passage to
the injected fluid, aa the bloodvessels and the movement of the blood
itael£ Beeide, the Qrst experiments of Poisseuille and others have
not been since invalidated, in any cssontiiil pariicular. It was found,
it is true, that certain other substances, injected at the same time
with the saline matter, might hasten or retard the circulation to k
certain degree. But thcso variations were noL very marked, and
never exceeded the limits of from eigliteen bo forty-Gve seconds.
There is no doubt that the blood itself makes the same circuit in
▼erj nearly the same interval of time.

The truth is, however, that we oannot fix upon any absolutely
uniform rate which shnll express the time required by the entire
blood to pass the round of the whole vascular system, and retuni
to a given point. The circulation of the blood, far from being a
Btmple phenomenon, like a current of water through a circular tube,
is, on tbe contrary, extremely oompticaled in all its anatomical and
physiological conditions; and it differs in rapidity, as well as in its
physical and chemical phenomena, in diflcrent parts of the circa-
Intory apparatus. We have already aeen how much the form of
the capillary plexus varies in dtflerent organs. In some the vasoa-
l&r network is close, in others comparatively open. In some its
meshes are circular in shape, in others polygonal, in others reclan-
gular. In some the vessels arc arranged in twisted loops, tn others
they communicate by irregular but abundant inosculations. The
mere distance at which an organ is situated from the heart must
modify to some extent the time required for its blood to return
again lo the centre of the circulation. The blood which psssas
through the coronary arteries, for example, and tbe capillaries of
the heart itself, must be reluroed to the right auricle in a compnr*-
tively short time; while that which is curried by the carotids into

S8«

THE CIBCrLATIOT.

the capillary system of ibe head and neck, to return by the JDguIar<i,
will re<iuire a longer interval. That, again, which deicends by the
abdominal aorta and its divisions to the tower extremities, ao'l
which, after circulating through the tissues of the leg and foot,
mounts upward ihrouj^h the whole course of the saphena, femoral,
ilinc and abdominal veins, must be still longeron its way; white
that which circulfltea through the abdominal digestive organs and
is then collected by theportal system, to be again dispersed through
the glandular tissue of the liver, requires undoubtedly a longer
pericKl siill lo perform its double capillary circulation. The blood,
therefore, arrives at the right side of the heart, from different parts
of tho bwly, at successive intervals; and may pass severnl timeii
through uue organ while performing a siuglo circulation through
another.

Furthermore, the chemical phenomena taking place in the blood
and the tissues vary to a similnr extent in different oi^ns. The
actions of transformation and decomposition, of nutrition and secre-
tion, of endosniosis and cxosmosis, which go on simultaneously
throughout the body, are yet extremely varied in their character,
and produce a similar variation in the phenomena of the circula-
lion. In one organ the blood loses more fluid than it absorbs; tu
another it abttorbs more than it loses. The venous blood, conse'
quoutly, has a different composition us it returns from different
organs. lu the bniin and spinnl cord it gives up those ingredients
necessairy for tho nutrition of the nervous matter, and absorbs cho-
lesterine and other materials resulting from its waste; in the muscles
it loses those substances necessary for the supply of the muscular
tissue, and in the bones those which are requisite for the osseous
system. Inthe parotid gland it yields the ingredients of the saliva;
in the kidneys, those of the urine. In the intestine it absorbs in
large quantity the nutritious elements of the digested fix)d ; and in
the liver, gives up substances rlei^tined finally to produce the bile,
nt the same time thai it absorbs sugar, which has been produced
in the hepatic tissue. In the lungs, again, it is the elimination of
carbonic acid and the absorption of oxygon that constitute its prin-
cipal changes. It has been already remarked that the tempcraiure
of the blood varies in different veins, acconling to the peculiar
chemical and nutritive changes going on tn the organs from which
they originate. Its color, even, which is also dependent on the
chetnicnl and nuiritive aciinns taking place in the capillaries, varies
in a similar manner. In the lungs, it changes from blue to red;

I
I

tOCAL rABTATT0:e8.

Fl(. 101.

in the capillaries of the general system, rrom red to blue. But its

tin^e &\»j varies very consi'lembly in different parts of the general

virculiition. The blood of ihe bcpaUc

reina is darker than that of the femoral

or brachial vein. In the renal veins

it 13 verv much brighter than in the

Teoa cava; and when the circulatioa

through the kidneys is free, the bloud

returning from ihem is nearly as red

AS arterial blood.

We must regard the citxjulotion of
the blood, therefore, not as a simple
process, but as made up of many difler-
eDt circalAiionf>, going on simultjine*
oasly iu diftorent organs. It baa been
cuatomary to illustrate it, iu diagram,
by a double circle, or figure of 8, of
irhicb the upper arc is used to reprc-
wntthe pulmonar}-. the lower the gen-
eral circulation. This, however, gives
but a very imperfect idea of the entire
circolaiion, as it really takes place. It
would be much more accurately re-
prewDted by such a diagram as that
in yig. 101, in which iia variations
in different parts of the body are
indicated in such a manner as to show,
in some degree, the complicated cha-
racter of its phenomena. The circula-
tion is modified in these different parta,
not only in its mechanism, but also in
its rapidity and quantity, and in the
natritive functions performed by the
blood. In one part, it stimulates the
nervoos centres and the organs of
special sense; in others it supplies the
fluid secretions, or the ingredients of
the solid tissues. One portion, in
passing through the digestive appara-
tiu, absorbs the materials requisite
for the nourishment of the bot^y: another, in circulating through

PiKma of tl>« CiBCPt.irp<tv.— I
ttoarl t Luiifs, 3. H**d mud nppvr
• iiniiuUlH *. Bplr*a. A. lulanllna. O
KI<lo«r 7. Law«r«Xlr«iDltl«*. S. Ufr.

288 THK CIRCULATION.

the luhga, exhales the carbonic acid which it has accumalated else-
where, and absorbs the oxygen wbiah is afterward transported to
distant tissues by the current of arterial blood. The phenomena of
the circulation are even liable, as we have already seen, to periodical
variations in the same organ ; increasing or diminishing in intensity
with the condition of rest or activity of the whole body, or of the
particular organ which is the subject of observation.

lUBIBITIOir AKD ZZHALATIOX. 289

CHAPTEB XV.

IMBIBITION AND EXH ALATIO N.— THE LYMPHATIC

SYSTEM.

DiTRiNG the passage of the blood through the capillaries of the
circalatory system, a very important series of changes takes place
by which its ingredients are partly transferred to the tissues by
exhalation, and at the same time replaced by others which the blood
deiives by absorption from the adjacent parts. These phenomena
depend upon the property, belonging to animal membranes, of
imbibing or absorbing certain fiuid substances in a peculiar way.
They are known more particularly as the phenomena of endoamosia
and exoamosia.

These phenomena may be demonstrated in the following way. If
we take two different liquids, for example a solution of salt and an
equal quantity of distilled water, and inclose them in a glass vessel
with a fresh animal membrane stretched between, so that there is
no direct communication from one to the other, the two liquids
being in contact with opposite sides of the membrane, it will be
found after a time that the liquids have become mixed, to a cer-
tain extent, with each other. A part of the salt will have passed
into the distilled water, giving it a saline taste; and a part of the
water will have passed into the saline solution, making it more
dilute than before. If the quantities of the two liquids, which
have become so transferred, be measured, it will be found that a
comparatively large quantity of the water has passed into the
saline solution, and a comparatively small quantity of the saline
solution has passed oat into the water. That is, the water passes
inward to the salt more rapidly than the salt passes outward to the
Tater. The consequence is, that an accumulation soon begins to
■how itself on the side of the salt. The saline solution is increased
in volume and diluted, while the water is diminished in volume,
and acquires a saline ingredient This abundant passage of the
water, through the membrane, to the salt, is called endoemosis; and
19

290

IUBIB1TTOM AND BXHAt.ATTON.

the more scanty passage of ihe snlt outward to the water is called

The mode usually adopted for measuring the mpidity of eiidos-
mosis is to take a glass vessel, ahaped somewhat like an inverted
funnel, wide at the bottom and nnrrow at the top. The bottom of
the vessel is cloaed by a thiu »nimal membrane, like the mucous
membrane of an ux-bladder, whiub is stretcUiid tightly over it« edge
and secured by a ligature, from the top of ihe vessel there rises
a very narrow glaiw tube, open at its upper extremity. Wiien the
instrument is thus prepared, it is filled with a solution of sngar
and placed in a vessel of distilled water, so that the animal mem-
brane, stretched across its mouth, shall be iu contact with pure
water on one side and with the saccharine solution on the other.
The water then passes in through the membrane, by endosmosis, J
faster than the saccharine solution passes out. An accutnulation
therefore takes place inside the vessel, and the level of the fluid
rises in the upright tube. The height to which the fluid thus rises
in a given time is a measure of the intensity of the endosmosis, and
of its excess over exosmosis. By varyitjg the constitution of the
two liquids, the arrangement of the membrane, kc, the variation
in endosmottc action under different conditions may be easily^
ascertained. Such an instrument ia called an endoamomel^. ■

If the extremity of the upright tube be bent over, so as to point
downward, as endosmoais continues to go on after the tube has
become entirely filled by the rising of the fluid, the saccharine solu-
tion will be discharged in drops I'rom the end of the tube, and fall
back into the vase of water. A steady circulation will thus be
kept up for a time by the force of endosmosis. The water still
passes through the membrane, and accumulates in the endosroo-
meter; but, as this is already full of Huid, the surplus immediately
falls back into the outside vase, and thus a current is established,
which will go on until the two li<^uids have bewme intimately
mingled,

Tlie conditions which influence the rapidity and extent of endos
mosia have been most thoroughly investigated by Datrochet, who
was the first to make a systematic cxamiDation of the subject.

The first of these conditions is the freshness of the membrane itself.
This is an indispensable requisite for the success of the experiment,
A membrane that bus been dried and moi.stcncd again, or one that ■
has begun to putrefy, will not produce the desired effect. It ha»M
been also found that if the membrane of the endosmometer be

THE LTUPHATIO BYSTEU. 291

allowed to remain and soak in the fluids, after the column has risen
to a certain height in the upright tube, it begins to desceod again
as soon as putrefaction commences, and the two liquids finally sink
to the same level.

The next condition is the extent o/corUact between the membrane
and the two liquids. The greater the extent of this contact, the
more rapid and forcible is the current of endosmosis. An endos-
mometer with a wide mouth will produce more effect than with a
narrow one, though the volume of the liquid contained in it may be
the same in both iustances. The action takes place at the surface
of the membrane, and is proportionate to its extent.

Another very important circumstance is the comtitution of the iico
i^uida, and their relation to each other. As a general thing, if we
use water and a saline solution in our experiments, endosmosis is
more active, the more concentrated is the solution in the endosmo-
meter. A larger quantity of water will pass inward toward a decse
solution than toward one which is already dilute. But the force of
endosmosis varies with different liquids, even when they are of the
same density. Datrochet measured the force with which water
passed through the mucous membrane of an ox-bladder into difl^er-
ent solutions of the same density. He found that the force varies
with different substances, as follows:' —

BndMinoBU of Wftter, with k BOlation of albamen
*• " " Bugsr .

M » H gam

« *• « golatine

The position of Uie membrane also makes a difference. With some
floids, endosmosis is more rapid when the membrane has its mucous
surlHce in contact with the dense solution, and its dissected surface
in contact with the water. With other substances the most favor-
able position is the reverse. Matteucci found that, in using the
macous membrane of the ox-bladder with water and a solution of
sogar, if the mucous surface of the membrane were in contact with
the saccharine solution, the liquid rose in the eudosmometer between
four and five inches. But if the same surface were turned outward
toward the water, the column of fluid was less than three inches in
height. Bififerent membranes also act with different degrees of force.
The effect produced is not the same with the integument of di£ferent
animals, nor with mucous membranes taken from difierent parts of
the body.

> In Matteooei'a Lectnraa on the Physioal Phenomena of Living Betngt. Phllada.,
1848, p. 48.

292 lUBIBITIOX AXO SXHALATIOy.

(renorally speaking, endosmosia is more active when the temper-
attire is moderately elevated. Dutrochet noticed that an endoamo-
meter, containing a solution of gam, absorbed only one volume of
water at a temperature of 82° Fabr, but absorbed three volumes
at a temperature a little above 90°. Variations of temperature will
sometimea even change the direction of the endosmoais altogether,
particularly with dilute solutions of hydrochloric acid. Dutrochet
fuun'l, for example,' llial when the endosinometer was filled with
dilute hydrochloric acid and placed in distilled wntor, at the tem-
perature of 50° F., endosmoais touk place from the acid to the water,
if the density of the acid aolution were less than 1.020; but that it
took place from the water to the acid, if its density were greater
than this. On the other hand, at the temperature of 72° F., the
current was from within outward when the density of the acid sola-
tion was below l.OOS, and from without inward when it was above
that point.

Finally, the ^rewure which is exerted upon the fluids and the
membrane favors their endosmosts. Fluids that pass aluwly under
a low pressure will pass more rapidly with a higher one. Different
liquids, too, require different degrees of pressure to make them
pass the same metnbrane. Ljebig* has measured the pressure re-
quired for several difl'erent liquids, in order to make them pasa
through the same membrane. He found that this pressure was

IsCMM or Hkxci-rt.

For alcohol 92

For oil 87

Por flolntioa of e&lt 20

Vnt water 13

There are some cases in wliich endusmosis takes place without
being accompanied by exosmosis. This occurs, for example, when
we use water and albumen as the two liquids. For while water
teadily passes in through the animal membrane, the albumen does
not pass out- If an opening be made, for example, in the large
end uf an egg, so as to oxpoise the shell -membrane, and the whole
be then placed io a goblet of water, endosmosls will take place very
freely from the water to the albumen, so as to distend the shell*
mcmbratie and make it protrude, like a Keniia, from the opening in
the shell. 13ut tlie albumen does not pass outward through the
membrane, and the water in the goblet remains pure. AAer a time,

' In Ullno Kdtrsrds, L^ons s-ar la Ptiralologle, &o., vol. t. p. llH.
< In Uiugol'a TniU d« PbjnioIagi«, rol. i. ^ SHi.

however, the accumulation of fluid in the inicrior bcoomos tio ex*
cessive as to burst the shell -membrane, and then the two liquids
become mixed indiacriraiiiately together.

These are the principal conditions by which endosmoais is influ-
eooed and regulated. Let us now see what is the nature of the
process, and upon what its ]>henomcQ& depend.

EndosmoHis is not dependent upon the simple force of diffusioa
or admixture of two diQ'crant liquids. For sometimes, as in the
case of albumen and water, all the ^uid passes in one direction and
none in the oilier. It is true that the activity of the process de-
pends very much, as wc have already seen, upun the difference in
constitution of the two liquids. With water and a saline solution,
for instance, the stronger the solution of suit, the more rapid is the
eodosmosis of tlie water. And if two solutions of salt be used,
with a membranous septam between them, cndnsmoais lalccs place
from the weaker solution to the stronger^ and is proportionate io
activity to the diftbrcnce in their densities. From this fact, Dutro-
chet was at first led to believe that the direction of endosmosis was
determined by the difference in density of the two liquids, and that
the current of accumulation was always directed from the lighter
liquid to the denser. But we now know that this is not the case.
For though, with solutions of salt^ sugar, and the like, the current
of endosmosis is from the lighter to the denser liquid; in other
instances, it is the reverse. With water and alcohol, for example,
endosmosis takes place, not from the alcohol to the water, but from
the water to the alcohol; that is from the denser liquid tu the lighter.
The diflerenco in density of the liquids, thurofore, is not the only
condition which regulates the direction of the endosmotic current.
In point of fact, the process of endosmosis docs not depend princi-
pally upon the attraction of the two liqaids for each other, but
apoo the aUraclion of tfte animal membrane /or the two liquids. The
membrane is not a pasaive Ulter through which the liquids min}j;lc,
hut it is the active agent which determines their passage. The
membrane has the power of absorbing liquids, and of taking them
up into its own substance. This power of absorption, belonging lo
the membrane, depends upon the organic or albuminous ingredients
of which it is composed; and, with difforeut animal substances, the
power of absorption is dillereut. The tissue of cartilage, for exam-
ple, will absorb more water, weight for weight, than that of the
tendons; and the tissue of the cornea will absurb nearly twice as
macb as that of cartilage.

294

IMIIIBTTTO:? AND EXnALATIOV.

Beside, the potver of absorption of an animal membrane is dif-
ferent for tiilTerent liquiris. Nearly all animal membranes absorb
pure water more froety than a solution of salt. If a membrane,
partly dried, be placed in a satorated saline solution, it will absorb
tlie water in larger proportion than the salt, and a part of the salt
will, iberefore, bo dcpoaJtod in the form of crystals on the surface
of the membrane.

Oily mattem, on the other hand, are usaally absorbed less readily
than either water or salioe solutions.

ChevTeuil haa investigated the absorbent power of different
animal substances for diffure^nt liquids, by taking definite quanti-
ties of the animal snbsiance and immersing it for twenty-foar
hours in different liquids. At the end of that time, iho suhsuinoe
was removed and weighed. Its increase in weight showed tbe
quantity of liquid which it had absorbed. The rsisults whiah were
obtained arc given in the following table: — *

100 pAii-n OF

Watbb.

SAU^rfigGLcnox.

Ou..

(,'artilngr,

■ 2St parts.

122 (larU.

TeiiJoQ,

178 ■•

114 "

S.G purtt.

Eliistic ]igiita<<ut,

absorb in

148 "

80 "

7.2 "

Coniiwi,

24 hourn,

-If:! -

870 '■

9.1 "

OrliliiKinoa* lig&ncnt,

31S "

8.2 "

Dried flbfin,

301 '■

154 "

The same substance, therefore, will take up different quantities
of water, saline solutions, and oil.

Accordingly, when an animal membrane is placed in contact
with two different liquids, it ab&i^rbs oue of them more abundantly
than the other; and that which is absorbed in the greatest quantity
is also diflfused most abundantly into the liquid on the opposite side
of the membrane. A rapid endosmosi.s takes place in one direo-
tion, and a slow exosmosis in the other. Consequently, the least
absorbable Buid increases iu volume by the constant admijLture of
that which is taken up more rapidly.

The process of endosmoais, therefore, is essentially one of im.
bibiiion or absorption of the liquid by an animal membrane, com-
posed of organic ingredients. We have already shown, in do-
scribing the organic proximate principles in a previous chapter,
tbat these substances have the power of absorbing watery and
serous fluids in a peculiar way. In cndosmosis, accordingly, the

I
I

■ la Loti|{vt'i Trail«d« Plij-aiotogi*, vol. 1. p. 3S3.

THB tiTUPHAtlC 8T8TBU.

296

imbibed fluid penetrates the luembrnne by n kind of chemical
combinatioD, and unites intimately with the substance of which its
tissuea are composed.

It is in this way that all imbibition and transudation take place
in the living body. Under the most ordinary contlitions, the transu-
dation of certain fluids is accomplished wilb great rapidity. Il has
been shown by XI. tiosselin,' that if a watery solution of iodide of
potassium be dropped upoti the cornea of a living rabbit, the
iodine penetrates into the cornea, aqueous humor, iris, lens, sclerotic
and vitreous body, in the course of eleven minutes; and that it
will penetrate through the cornea into tLe aqueous humor in three
minutes, and into the substance of the cornea in a minute and a
half. In these experiments it was evident that ihe iodine actually
passed into the deeper portions of the eye by simple endosmosis,
snd was not transported by the vessels of the general circulation ;
since no trace of it could bo found in the tissues of the upposiia
eye, examined at the same time.

Th« same observer allowed that the active principle of belladonna'
penetrates the tissues of the eyeball in a similar manner. M. lios-
selin applied a solution of sulphate of atropine to both eyes of two
rabbits, ilnlf an hour afbcrwanl, the papik were dilated. Three
quarters of an hour later, the aqueous humor was collected by
puncturing the cornea with a trocar; and this aqueous humor,
dropfied upon the eye of a cat, produced dilatation and immobility
of the pupil in half an hour. These facts show that the aqueous
humor of the aifccied eye actually contains atropine, which it
absorbs from without through the cornea, and thU atropine then
acts directly and locally upon the muscular fibres of the iris.

But in all the vascular organs, tho processes of endosmosis and
exosmosis are very much accelerated by two important conditions,
Viz., first, the movcmeni of tho blood in circulating through the
vessels, and secondly the minute diitsemination and distribution of
these vessels through the tiiisue of the organs.

The movement of a fluid in a continuous current always favors
endosmoeis through the membrane with which it i^ in contact. For
if the two liquids be stationary, on the opposite sides of an animal
membrane, as soon as endosmosis commences they begin to a[)-
proximal« in constitution to each other by mutual admixture; and,
OS ibis admixture goes on, endosmosia of course becomes less active,

' Qu*.-u« Butxlouiadnln, S«|)U T, UH.

296

IMBIBITIOy AKI> IXHALATIOy.

and ceases entirely when the two liquids have become perfecU_
similar in comiwailion. But if one of the liquids be constantly
renewed by a continuoas correot, those portions of it whicb have
become oontaniiiiatcd are immediately carried away by the stream
!ind replaced by I'resh portions in a alote of purity. Thus Uic
diflereuce in coDJtltution of the two liquids is preserved, and
traosudatioa will contiuue to take place between them with una-
bated rapidity.

Alaticucci demonstrated the effect of a current in facilitating
endosmosis by attaching to the sLopcook of a glass rc^iurvoir filled
with water, a portion of a vein also filled with water. The vein
waa then immersed in a very dilute solution of hydrochloric acid.
So long as tlie water remained stationary in the vein it did not give
any indications of the presence of the acid, or did so only very
slowly ; but if a current were allowed to pass through the vein by
opening the stopcock of the reservoir, then the fluid runDiDg from
its extremity almost immediately showed an acid reaction.

The same thing may ho shown even more distinctly npon the
living animal. If a solution of the extract of nux vomica be in-
jected into the subcutaneous areolar tissue of the hind leg of two
rabbits, in one of which the bloodvessels of the e,\treroily have
been left free, while in the other they have been previously tied,
80 as to atop the circulation in that part — in the first rabbit, the
poison will be absorbed and will produce convulsions and death in
the course of a few minutes; but in the second animal, owing t') the
stoppage of the local circulation, absorption will be much retarded,
and the poison will find ita way into the general circulation so
slowly, and in such small quantities, that its speciBc effects will show
themselves only at a late period, or even may not be produced at all.

The anatomical arrangement of the bloodvessels and adjacent
tisanes is the second important condition regulating cndoiiinosia
and exoamosie. We have already seen that the network of capil-
lary bloodvessels results from the excessive division and rami6cA*
lion of the smaller arteries. The blood, therefore, as it leaves the
arteries and enters the capillaries, is constantly divided into smaller
and more numerous currents, which are 6nany disseminated in the
most intricate manner throughout the snbstance of the organs aad
tLHSues. Thus, the blood is brought into intimate contact with Iho
surrounding tissues, over a com(niralively very large extent of sur-
foce. It lias already been stated, as the result of Dutrochet's inves-
tigations, that the activity of endosmosis is in direct proportion to

THE LTMPHATIC 8YSTEU.

297

the estent of surfnce over which the two liquids come in contact
with the intervening membrane. It is very evident, therefore, that
it win be very much facilitated by tb« anatomical distribution of
the capillary blood vesseLs.

It in in some of the glandular organs, however, that the transu-
dation of fluids can be shown to take place with the greatest, rapi-
dity. For in these organs the eihaling and absorbing surfaces are
arranged in the form of minute ramifying tubes and follicles, which
penetrate everywhere through the glanduliir t^ubstance; while the
capillary bloodveiLsela form an ciiualty eoniplicated and abinidnnt
network, situated between the adjacent follicles aud ducts. In this
way, the union and interlncetnent of the glandular membrane, on
the one hand, and the btuudveti^ela on the other, become exueed-
ingly intricate and extensive: and the ingredients of the blood are
almost instontaneoualy subjected, over a very large surface, to the
influence of the glandular membrane.

The rapidity of transudation through the glandular membranes
has been shown in a very striking manner by Bernard.' This ob-
server injected a solution of iodide of potassium into the duct of
the parotid gland on the right side, in a living dog, and immediately
afterward found iodine to be present in the saliva of the correspond-
ing gland on the oppoitite Hide. In the few instants, therefore, re-
quired to perform the experiment, tho salt of iodine must have
been taken up by the glandular tissue on one side, carried by the
blood of the general circulation to the opposite gland, and there
tmnaudcd through the secreting membrane.

We have also found the transudation of iodine through the
glandular tissue to bo exceedingly rapid, by the Following experi-
ment. The parotid duct was exposed and opened, upon one side,
in a living dog, and a oanula inserted into it, and secured by liga-
ture. The secretion of the parotid saliva was then excited, by in-
trodacing a little vinegar into the mouth of the animal, aud the
Baliva, thus obtained, found to be entirely destitute of iodine. A
aolution of iodide of potassium being then injected into the jngu*
lar veiu, and the parotid secretion again immediately excited by
the introductioD of vinegar, as before, the aaliva first discharged
IVom tha oanula showed evident traces of iodine, by striking a blue
color on the addition of starch and nitric acid.

Tht processes of exosmosis and eudosmosis, therefore, in the living

* L»^[M di» Pliysiologf* ExpfaiuM-ntAto, Piria, 18S4, p. 107.

29S

IMBIBITION AND EXHALATION.

body, are regulated by tbe same conditions aa in artificial experi-
ments, but tliey take place with infiuilcly greater rapidity, owing to
tlie movement of the eirculai'ing blood, and tbe extent of contact
oxiaiing between the bloodvessel and mljaccnt tissuejt. We havo
alrendy seen that tlie absorption of the same fluid is accomplished
with diiVtirent degretfs of rapidity by diHereiit animal substanoea.
Accordingly, though the arterial blood is everywhere the same ia
conipoflition, yet its different ingredients are imbibed in varjiny
quantities by the diftercnt tissues. Thus, the cartilages absorb
from the circulating fluid a Inrger proportion of phosphate of lime
than the softer ti^uet;, and the bones a larger proportion than the
cartilages; and the watery and saline ingredients generally are
found in different quantities in difierent parts of the body. The
same animal membrane, also, aa it has been shown by experiment,
will imbibe diEferont substances with different degrees of facility.
Thus, the blooi), for example, contains more chloride of sodium
than chloride of potassium ; but the muscles, which it supplies with
nourishment, contain more chloride of potassium than chloride of
sodium. In this way, tbe proportion of each ingredient derived
from the blood is determined, in each separate tissue, by its special
absorbing or endosmotic power. M

Furthermore, we have seen that, albumen, under ordinary eondi- V
tions, is not endosmotic; that is, it will not pass by transudation
through au animal membrane. l''or tbe same reason, the albumen
of the blood, in the natural state of the circulation, is not exhaled
from the secreting surfaces, but is retained within the circulatory
Hyslem, while the watery and sa.Iine ingredients transude in varying
quantities. But the degree o( pressure to which a tluid is subjected,
has great influence in determining its endosmotic action. A sub-
stance which passes but glowly under a low pressure, may pass
much more rapidly if the force bo increased. Accordingly, we find
that if the pressure upon the blood in the vessels be increased, by
obstmctioQ to the venous current and backward congestion of Ihel
capillaries, then not only the saline and watery parts of the blood
pass out in larger quantities, but the albumen itself transudes, and
infiltrates the neighboring parts. It is in this way that albumen
makes its ap|7oarance in the urine, in consequence of obetruction to
the renal circulation, and that local cedema or general anasarca
may follow upon venous congestion in ^mrticular regions, or upon
general disturbance of the circulation.

The processes of imbibitiun and exudation, which thus take

TEB LTHPHATIC BT8TSM. 209

place incessantly throughout the body, are intimately connected
with the action of the great absorbent or lymphatic system of ves-
kIs, which is to be considered as secondary or complementary to
that of the sanguiferous circulation.

The lymphatics may be regarded as a system of vessels, com<
menciag in the substance of the various tissues and organs, and
endowed with the property of absorbing certain of their ingredi-
CDtB, Tbeir commeocement has been demonstrated by injections,
more particularly in the membranous parts of the body; viz., in
the skin, the mucous membranes, the serous and synovial surfaces,
and the inner tunic of the arteries and veins. They originate in
these situations by vascular networks, not very unlike those of the
capillary bloodvessels. Notwithstanding this resemblance in form
between the capillary plexuses of the lymphatics and the blood-
nssels, it is most probable that they are anatomically distinct from
each other. It has been supposed, at various times, that there
might be communications between them, and even that the lymph-
atic plexus might be a direct continuation of that originating from
the smaller arteries; but this has never been demonstrated, and it
is now almost universally conceded that the anatomical evidence is
in favor of a complete separation between the two vascular systems.

Commencing in this way in the substance of the tissues, by a
Tascalar network, the minute lymphatics unite gradually with each
other to form larger vessels; and, after continuing their course for
a certain distance from without inward, they enter and are distri-
bated to the substance of the lymphatic glands. According to M.
ColiD,* beside the more minute and convoluted vessels in each gland,
there are always some larger branches which pass directly through
ih substance, from the afferent to the efferent vessels ; so that only
I portion of the lymph is distributed to its ultimate glandular
plexus. This portion, however, in passing through the organ, is
eridently subjected to some glandular influence, which mny serve
to modify its composition.

After passing through these glandular organs, the lymphatic
Tesaels unite into two great trunks (Fig. 43): the thoracic duct, which
collects the fluid from the absorbents of the lower extremities, the
intestines and other abdominal organs, the chest, the left upper
extremity, and the left side of the head and neck, and terminates
in the left subclavian vein, at the junction of the internal jugular;
and the right lymphatic duct, which collects the fluid from the right

I nijsiolDgie oompxrfe di» Aoimauz domestiqnes, Paris, 165G, toL ii. p. G8.

IHBIBITION AND EXHALATIOIf.

opper extremity and right aide of the head and neclc, and joins the
right subclavian vein at its junction with the corresponding jugular.
Thus nearly all the lymph from the exterttal parts, and the whole
of that from the abdominal organs, passes, by the thoracic duct^fl
into the loft subclaviaa vein. I

Wc already know that the lymphatic vessels are not to bo re- "
garded as the exclusive agents of absorption. On the contrary,
absorption takes place by the bloodvesselB even more rapidly nnd^
abundantly than by the lymphatics. Even the products of digea- ■
tion, including the chyle, are taken up from the intestine ia large f
proportion by the bloodvessels, and are only in part absorbed by
the lymphatics. But the main peculiarity of the lymphatic system h
is that its vessels all pass in one direction, viz., from without inward, V
and none from within outward. Consequently, there is no circula-
tion of the lymph, strictly spenking, like that of the bloo<l, but ic^
is all supplied by exudation and absorption from the tissues. V

The lymph has been obtained, in a state of purity, by various
experimenters, by introducing n canula into the thoracic duct, at
the root of the neck, or into large lymphatic trunks in other parts
of the body. It has been obtained by Keea from the lacteal vessels
and the lymphatics of the leg in the ass, by Colin from the Incteals
and thoracic duct of the ox, and from the lymphatics of the neck
in the horae. We have also obtained it, on several different occa-
sions, from the thoracic duct of the dog and of the goat. fl

The analysis of these fluids shows a remarkable similarity <aV
constitution between them and the plasma of the blood. Tboy *
contain water, fibrin, albumen, fatty matters, and the usual saline
substancea of the animal fluids. At the same time, the lymph is
very much poorer in albuminous ingredient than the blood. The
following is an analysis, by Lassaigae,' of the Quid obtained from
the thoracic duct of the cow: —

W»t«r 9tf4.«

Fibrin 0.9

AlbQw^n 2S.0

Kill 0.4

Cliloridw of sodium 5.0

C&rbonjita, 1

I'hMliliAte B.nd I of Sodft 1.3

Ual|>liitLti )

J'litMphate of Urns 0-fi

IIKIO.0

■ Cotin, ]'li7«iol'ii|{i<) cciinpAT^tt dva Aniuaanx domes Ui|aM, vol. II. p. 111.

THE LTBCPHATIC BTSTEH. 801

It thus appears that both the fibrin and the albninen of the blood
tctnallj traDBode to a certain extent from the bloodvessels, even in
the ordinarj condition of the circulatory system. Bat this transada-
tion takes place in so small a quantity that the albnrainous matters
are all taken ap again by the lymphatic vessels, and do not appear
io the excreted fluids.

The first important peculiarity which is noticed in regard to the
floid of the lymphatic system, especially in the carnivorous animals,
is that it varies very mnch, both in appearance and constitution, at
different times. In the ruminating and graminivorous animals,
sQch as the sheep, ox, goat, horse, &c., it is either opalescent in
appearance, with a slight amber tinge, or nearly transparent and
colorless. In the carnivorous animals, such as the dog and cat, it
is also opaline and amber colored, in the intervals of digestion, but
soon after feeding becomes of dense, opaque, milky white, and con-
tinues to present that appearance until the processes of digestion
and intestinal absorption are completed. It then regains its original
aspect, and remaioa opaline or semi-transparent until digestion is
again in progress.

The cause of this variable constitution of the fluid discharged
by the thoracic duct is the absorption of fatty substances from the
intestine during digestion. Whenever fatty substances exist in con-
liderable quantity in the food, they are reduced, by the process of
digestion, to a white, creamy mixture of molecular fat, suspended
in an albuminous menstruum. The mixture is then absorbed by
the lymphatics of the mesentery, and transported by them through
the thoracic duct to the subclavian vein. While this absorption is
going on, therefore, the fluid of the thoracic dnct altera its appear*
ance, becomes white and opaque, and is then called chyle; so that
there are two different conditions in which the contents of the great
tjmphatic trunks present different appearances. In the fasting
condition, these vessels contain a semi-transparent, or opaline and
nearly colorless lymph; and during digestion, an opaque, milky
chyle. It is on this account that the lymphatics of the mesentery
are called "lacteals."

The chyle, accordingly, is nothing more than the lymph which
is constantly absorbed by the lymphatic system everywhere, with
the addition of more or lees fatty ingredients taken up from the
intestine during the digestion of food.
, The results of analysis show positively that the varying appear-
ance of the lymphatic fluids is really due to this cause; for though

302 litfilftlTtOK AVb EXBALATIOK.

the clijle is also richer than the lymph in albumtnoas mattors, the
principa] difference between iheni consists in the proportion of fat.
This is shown by the following comparative anal^-sis of the lymph
uud chyia of llio ass, by Dr. Keea:'—

LnrpH. Chylb.

Water SBS.Se !K>2,37

AlbuiQ«n 12.00 39. 1«

Fibria 1.20 3.7i>

Spirit sxtract 2.40 3.33

Wfl.lsr extract 13.19 12.33

Fat lr*o«. 36.01

Balias uattor 9.85 7.11

1,(>CW.00 1,«>U.<I0

When a canula, accordingly, is introtluced into the thorncic duct
at various periu<l!> after feeding, the fluid which la discharged varies
considerably, both in appeamncc and quantity. We have foundfl
that, in the dog, the fluid of the thoracic duct never becomes quite
transparent, but retains a very marked opalitiu tinge even so late
as eighteen hours afler feeding, and at least three days and a half
after the introduction of fat food. Soon after feeding, however, as
we have already seen, it becomes whitish and opaque, and remains
so while digestion and absorption are in progress. It also becomes
more abundant soon after the commencement of digestion, but J
diminishesS again in quantity during its latter stages. We have™
found the lymph and chyle to be discharged from the thoracic duct,
in the dog, in the following quantities per hour, at different periods
of digestion. The quantities are calculated in proportion to the
entire weight of the animal.

Put Thoitiuxp Pakt».

3^ honre aft«>r f«edinj 2.45

7 " " " 2.20

13 " " '• 0.99

18 " ■' " 1.16

I8J " » " 1.&9

It would thus appear that the hourly quantity of lymph,
diminishing during the latter stages of digestion, increases again
somewhat, about the eighteenth hour, though it is still considera-
bly less abundant than while digestion was in active progress.

The lymph obtained from the thoracic duct at all periods uooga-j
lates soon ai';er its wiibdrawal, owing to the fibrin which it coDtaioaJ

< Id Colls, op. CLt.. Tcl. ii. p. 18.

THB LYHPBATIC ST8TBH. 803

in small qaantity, Afler coagulation, a separation takes place be-
tween the clot and serum, precisely as in the case of blood.

The movement of the Ijmph in the lymphatic vessels, from the
extremities toward the heart, is accomplished by various forces.
The first and most important of these forces is that by which the
flaids are originally absorbed by the lymphatic capillaries. Through-
oat the entire extent of the lymphatic system, an extensive process
of endosmosis is incessantly going on, by which the ingredients of
the lymph are imbibed from the surrounding tissues, and com-
pelled to pass into the lymphatic vessels. The lymphatics are thus
filled at their origin ; and, by mere force of accumulation, the fluids
&re then compelled, as their absorption continues, to discharge
tbemselves into the large veins in which the lymphatic trunks
terminate.

The movement of the fluids through the lymphatic system is
also favored by the coniraction of the voluntary muscles and the
respiratory motions of the chest. For as the lymphatic vessels are
provided with valves, arranged like those of the veins, opening
toward the heart and shutting backward toward the extremities,
the alternate compression and relaxation of the adjacent muscles,
and the expansion and collapse of the thoracic parietes, must have
the same effect npon the movement of the lymph as upon that of
the venous blood. By these difierent influences the chyle and
l^mph are incessantly carried from without inward, and discharged,
iQ a slow but continuous stream, into the returning current of the
venous blood.

The entire quantity of the lymph and chyle has been found, by
tirect experiment, to be very much larger than was previously
iDticipated. M. Colin^ measured the chyle discharged from the
thoracic duct of an ox during twenty-four hours, and found it to
exceed eighty pounds. In other experiments of the same kind, he
obtained still larger quantities.* From two experiments on the
horse, extending over a period of twelve hours each, he calculates
the quantity of chyle and lymph in this animal as from twelve to
fifteen thousand grains per hour, or between forty and fifly pounds
per day. But in the ruminating animals, according to his observa-
tions, the quantity is considerably greater. In an ordinary -sized
cow, the smallestquantity obtained in an experiment extending over

■ OsMtte Hebdomadaire, April, 24, 1857, p. 285.

■ CoHd, op. cit., vol. ii. p. 100.

304

IXBIUtTEOH AND EXHALATIOy.

I
I

a period of twelve hours, wns a liule over 9,000 gmina in 6fwe?
minutes; that is, five poinuls an hour, or 120 pounds per day. In
another experiment, with a young bull, he actually obtained a little
over too pounds from a fistula of the thoracic duct, in twenty*foar
hours.

Wo hare also obtained siniilar results by experiments apoo the
dog and goat. In a young kid, weighing fourteen pounds, we have
obtained from the thoracic duct 1690 grains of lymph in three
hours uud a half. This quantity would represent 540 grains in an
hoitr, end 12,i}90 grains, or 1.85 pounds, in twenty-foar hoars; and
in a ruminating animal weighing 1000 poands, this would corre-
spond to 132 pounds of lymph and chyle discharged by the thoracic,
duel in th« course of twenty-four hours.

The average of alt the results obtained by us, in the dog, at dif-
ferent periods after feeding, gives very nearly four and a half per
cent, of the entire weight of the animal, as the total daily quantity
ot lytnph and chyle. This is substantially the same result as that
obtaiued by Colin, in the horse; and for a man weighing 140
pounds, it would be equivalent to batweeu six and sis and a half
pounds of lymph and chyle per day. ■

But of this quantity a considerable portion consists of the chyle
which is absorbed from the intestines during the digestion of fatty
substances. If we wish, therefore, to ascertain the total amount of ■
the lymph, separate from that of the chyle, the calculation should
be based upon the quantity of fluid obtained, from the thoracic
duct In the intervals of digestion, when no chyle is in process of
absorption. We have seen that in the dog, eighteen hours after
feeding, the lymph, which is at that time opaline and semi-transpa-
rent, is discharged from the thoracic duct, in the counw of an boor,
in a quantity equal to 1.15 parts per thousand of the entire weight
of the aninial. In twenty-four hours this would amount to 27.6
pans per thousand; and for a man weighing 140 pounds this would
giva 3.864 pounds as the total daily quantity of the lymph alone.

It will be seen, therefore, that the processes of c.Tudation and
absorption, which go on in the interior of the body, produce a very
aotive interchange or mtemal drculaiion of the animal iluidd, which
may be considered as secondary to the circulation of the blood.
For all the digestive fluids, as we have found, together with the bile
discharged Into the intestine, are reabsorbed in the natural process
of digestion and again enter the current of the circalation. These
fluids, therefore, pass and repnss through the mucous membrane of

THE LYMPHATIC 8T8TEU. 805

the alimentary canal and adjacent glands, becoming somewhat
altered in constitation at each passage, but still serving to renovate
alternately the constitution of the blood and the ingredients of the
digestive secretions. Furthermore the elements of the blood itself
also transude in part from the capillary vessels, and are again taken
ap, by absorption, by the lymphatic vessels, to be finally restored
to the retarniug current of the venous blood, in the immediate
neighborhood of the heart.

The daily quantity of all the fluids, thus secreted and reabsorbed
daring twenty-four hoars, will enable us to estimate the activity
with which endosmosis and exosmosis go on in the living body.
In the following table, the quantities are all calculated for a man
weighing 140 poands.

SSCBBTED AND RbABSOBBID DITBtfO 24 BOtrBfl.

Balira 20,164 grains, or ?..880 poondii.

Outrio Jolos 98,000 "

" 14.000

Bile 16,940 "

" 2.420

PBDcreatio JnloB i;),104 "

" 1.872

lymph 27,048 "

" 3.884

26.036

A little over twenty-five pounds, therefore, of the animal fluids
tranaade through the internal membranes and are restored to the
blood by reabsorption in the course of a single day. It is by this
process that the natural constitution of the parts, though constantly
changing, is still maintained in its normal condition by the move-
ment of the circulating fluids, and the incessant renovation of their
Dntritiona materials.

S06

BSCRBTIOir.

CHAPTER XVI.

SECBETION.

Wk liave already seen, in a previous chapter, how the elements of
ihe blood are absorbed by the tiRsucs during the capillary circula-
tion, and assimilated by ihem or converted into their own sub«Unce.
Id this process, the inorganic or saline matter* are moelly tAkeo up
unchanged, and are merely appropriated by the surrouiidin{; \viTts in
particular quantities; while tho organic substances are transformed
into new compounds, characteristic of tho different tiRSiies by whicb
they are assimilated. In this way the varioos tissues of the body,
though they have a difterent chemical composition from the blood,
are nevertheless supplied by it with appropriate ingredients, and
their nutrition cunstanlly maintained.

Beside this process, which is known by the name of "assimila-
tion," there is another somewhat giioilar to it, which lakes place in
the different glandular organs, known as the process otKcntt'on. It
is the object of tliis function to supply certain fiuids, differing in
chemical constitution from the blood, which are required to assist
in various physical and chemical actions going on in the body.
These secreleii fluids, or "secretions," ait they are called, vary in
consistency, density, color, quantity, ami reaction. Some of thera
are thin and watery, like the tears and the perspiration; others arc
viscid and glutinous, like mucus and ihe pancreatic fluid. They
are alkaline tike the saliva, acid like the gastric juice, or neutral
like tbe bile. Each secretion contains water and the inorganic soils
of the blood, in varying proportions; and is furthermore distin-
guished by the presence of some peculiar animal subslauce which
does not exist in the blood, but which ia produced by the secreting
action of the glandular organ. As the blood circulates through the
capillaries of tho gland, its watery and saline constituents transude
in certain quantities, and arc discharged into the excretory duct.
At the same time, the glandular cells, which have themselves been
nourished by the blood, produce a new substance by the catalytic

SECRETION. 807

traDsformation of their organic conatitaeots; and this new sal»taiice
18 discharged also into the excretory duct and mingled with the
other ingredients of the secreted fluid. A true secretion, therefore,
is produced only in its own particular gland, and cannot be formed
elsewhere, since the glandular cells of that organ are the only
ones capable of producing its most characteristic ingredient. Thus
pepsine is formed only in the tubules of the gastric mucous mem-
brane, pancreatine only in the pancreas, taaro-cholate of soda only
in the liver.

One secreting gland, consequently, can never perform vicariously
the office of another. Those instances which have been from time
to time reported of such an unnatural action are not, properly
speaking, instances of "vicarious secretion;" but only cases in
which certain substances, already existing in the blood, have made
their appearance in secretions to which they do not naturally belong.
Thus cholesterine, which is produced in the brain and is taken up
from it by the blood, usually passes out with the bile; but it may
also appear in the fluid of hydrocele, or in inflammatory exuda-
tions. The sugar, again, which is produced in the liver and taken
Qp by the blood, when it accumulates in large quantity in the cir-
culating fluid, may pass out with the urine. The coloring matter
of the bile, in cases of biliary obstruction, may be reabsorbed, and
BO make its appearance in the serous fluids, or even in the perspira*
iaon. In these instances, however, the unnatural ingredient is not
actually produced by the kidneys, or the perspiratory glands, but
is merely supplied to them, already formed, by the blood. Cases
of "vicarious menstruation" are simply capillary hemorrhages
which take place from various mucous membranes, owing to tho
general disturbance of the circulation in amenorrhoea. A true
secretion, however, is always confined to the gland in which it
natarally originates.

The force by which the different secreted fluids Wte prepared in
thQ glandular organs, and discharged into their ducts, is a peculiar
one, and resident only in the glands themselves. It is not simply
a process of filtration, in which the ingredients of the secretion
exude from the bloodvessels by exosmosia under the influence of
pressure; since the most characteristic of these ingredients, as we
have idready mentioned, do not pre-exist in the blood, but are
formed in the substance of the gland itself. Substances, even,
which already exist in the blood in a soluble form, may not have
the power of passing out through the glandular tissue. Bernard

303

lOKBTIO!^.

has found* that ferrocyanitle of poUssium, when injected into tbe
jugular vein, though it appears with great facility in tbe urine,
dues not pass out with the saliva; and even that a solution of
the same salt, injected into the duct of the parotid gland, is ab-
sorbed, tnken up by the blood, and discharged with the urine; but
does not appear in the saliva, even of the gland into wbiuh It bos
been injected. Tlic force with which the secreted fluids accuinuUtc
in the salivary dueta has also been shown by Ludwig's experi-
ments' to be sometimes greater than the pressure in the bloodvu-
sels. This author found, by applying mercurial gauges at tbe suae
time to the duut of Stuno and to the artery of tbe parotid gland, thai
the pressure in the duct from tho secreted saliva was considerablji
greater than that in the artery from the circulating blood; so that
the passage of the secreted fluids had really taken place id a direc-
tion contrary to that which would have been caused by the simple
influence of pre:isure.

The process of secretion, therefore, ts one which depends upoa
the peculiar anatomical and chemical conittitution of tbe glaDdaJar
tissue Hud its secreting cells. These cells have the property of
absorbing and transmitting from tho blood certain inorganic aod
saline substances, and of producing, by chemical metnmorphosia,
certain peculiar animal matters from their own tissue. These sob-
stances are then mingled together, dis^Ivcd in the watery fluiiU
of the secretion, and discharged simultaneously by tbe excretory
duct.

All the secreting organs vary in activity at diflToPent periods.
Sometimes they are nearly al rest; while at certain periods ther
become excited, under the influence of an occasional or periodical
stimulus, and then pour out their secretion with great rapidity audio
large quantity. The perspiration, for example, is usually ao slow);
secreted that it evaporates us rapidly as it is poured out. and ibe
surface of the Ain remains dry; but under the influence of unusual
boilily exercise or mental excitement it is secreted much (aoa
than it can evaporate, and the whole integument becomes covered
with moisture. Tho gastric juice, again, in tho intervals of dlgosttou,
is either not secreted at all, or is produceil in a nearly inappreciable
quantity; but on the introduction of food into the stomach, it ii
immediately poured out in Biach abundance, that between two awl
three ounces may be collected in a quarter of an hour.

■ l.r^D'tis da Phyilgloglti ExpdrltaeaUlv.
■lLld.,p. lOtt.

Paris, ISStf, lomu Ii. p. 9i> tt 1*9.

1IUC09.

809

The priDcipol secretioQS met with in the animal body are as
followa:—

1. Uueaa.

3. &«l<ftc«naft matter.

3. Pcmpfration.

4. Tli« iet.n.

5. Th« niilk.

«. Stlka.

T. OMtric Jtiicf.

8, Pancrt-atic Jnice.

9. Int«*tituil juict.
10. Bile.

The last five of these fluids have already been described in the
preceding chapters. We shal! therefore only require to examine
at present tbe five following, viz^ mucus, sebaceous matter, per-
spiration, the tears, and the milk, together with aome peculiarities
in tbe secretion of the bile.

ng. 102.

1. Moccs. — Nearly all the mucous membranes are provided with
follicles or glandulm, in which the mucus is prepared. Tliesc folli-
cles are most abundant in the lining membrane of the mouth, nare>:,
pharynx, oesophagua, trachea and bronchi, vagina, and male urethra.
They are generally of a compound form, consisting of a number of
secreting sacs or cavities, terminating at one end in a blind ex-
tremity, and opening by tbe other into a common duct by which
the secreted fluid is discharged. Each ultimate ficcreling sac or
follicle is lined with glamUilar epithelium (fig. 102), and surround-
ed on its external surface by a network of capillary bloodvessels.
These vessels, penetrating deeply into the
interstices between the fullicles, bring the
blood nearly into contact with the epithelial
cells lining its cavity. It is these cells
which prepare the secretion, and discharge
it afterward into the comtneucement of the
excretory duct.

The tnucus, produced in the manner
above described, is a clear, colorless fluid,
which is {K)ured out in larger or smaller
quantity on the surface of the mucous
membranes. Ii is distiiigui.-^hed from other aecretiona by its vis-
cidity, which is its most marked physical property, and which
depends on the presence of a peculiar animal matter, known under
Uie name of muamne. When unmixed with other animal fluids,
Uiis viscidity is so great that the mucus has nearly a semi-solid or
gelatinous conaislency. Thus, the mucus of the mouth, when ob-
tained onmixed with the secretions uf the salivary glands, is so

FoLlir-Ll* or * C«M-
rtttsa Mccnfla tiLtaOBl.*-
Pram cIl« horaauiubloct. (AfUt
Rntllkor >— n Mniilinntt at Ik*
follkta. t, t. KptllwHuiD of llw
tamo.

810 SECBBTrON.

toQgb and adhesive tbat the vessel containing it maybe tarned
upsidti down wiibuut its ninniug out. Tbs mucus of the cervix
uteri bos a similar Srm consistency, so as to block up tbe cavity
of tbis part of tbe organ with a Bemi-A>Iid gelatinous mass. Muciifl
is at the same time oxceeclitigly smooth and slippery to the touch,
60 that it lubricates readily the surfaces upoo which it ta exuded,
and facilitates the passage of foreign substances, while it defends
the mucous membrane itself from injury.

The coinpoaition of mucua, according to the analyses of Kasse,*
is OS follows;—

CoxriMiTiox w ]'ni.)i»»AftT HDctrn.

W»t»r 955.53

Animal mAtter 33.57

fiLt £.8»

Chlnritlvof •ixlIaTn 6.83

Pfaotphiit«i of Boita aoil poiasMi 1-06

Sulphatva » •- 0.<S

CarbonaU.* " » (1.43

low. TO

The animal matter of mucus is insoluble in water; and conse-
queuily mucus, wiien tJri^pped into water, does nut mix with it, but
is merely broken up by agitation into getalinons threads and flakes,
which subside afWr a time lo ibe bottom. It is misciWe, however,
lo some extent, with other animal Buids, and may be incorporated
with them, so as to become thinner and more dilute. It readily
takes on putrefactive changes, and communicates thorn to other
organic substances with which it may be in contact.

The varieties of mucus found in diS'erent parts of the body are
probably not identical in composition, hut differ a little in the cha-
racter of their principal organic ingredient, as well as in the pro-
portions of their saline constituents. The function of mucus is for
the most part a physical one, viz., to lubricate the mucous surfaces,
to deE'end them from injury, and to facilitate the t>assage of foreign
Bubsunces through their cavities.

2. Sebaceous Matter. — The sebaceous matter ia ilistinguished

by containing a very large proportion of latty or oily ingrevlienls.
There are three varieties of this secretion met with in the body, ■
viz., one produced by the .•sebaceous gland.^ of the skin, another
by the ccruminoua glands of the external auditory meatus, and
a third by the Meibomian glands of the eyelid. The sebaceous

SIiuod'i Cli«&ii>trj' of Uaii, Fbilada., IMi!, p. 352.

SEnAOSocra iiATTsn. Sll

glands of tbe skin are found most abundantly in those parts which
are thickly covered with haira, as well as on the face, the labia
minora of the female generative organs, the gliins penis, and the
prepuce. They consist aometimea of a simple follicle, or flask-
shaped cavity, opening by a single orifice; but more frequently of
R Dumber of such follicles grouped round a common excretory duct.
The duet nearly always opens ju^it at the root of one of the hairs,
which is smeared more or leas abundantly
with its secretion. Each follicle, a^ in ihe ^^e- 1<*3-

case of the mucous glandules, is lined
with epithelium, and its cavity is filled
with the secreltii) sebaceous matter.

In the Meibomian glands oF the eye- ^^■nc-r>
lid (Fig. 108), the follicles are ranged
aloDg the sides of an excretory duct,
situated just beneath the conjunctiva, on
the posterior surface of the tarsus, and
opening upon its free edge, a little be- ^^h Jt. a ^ «
hind the roots of tho eyelashes. The
ceruminoua glands of the external uuiU-
lory meatus, again, have the form of long
tubes, which terminate, at the lower part
of the uitegumcnt lining the meatus, tii Lii4i.,tie.
a globular coil, or convolution, covered
externally by a network of capillary blood ve-^sels.

The sebaceous matter of the skin has the following compositiun,
according to Esenbeck.'

CoMPoeiTCOS up SsBActoos Uattsb.

AnfEiiiit nabntnncM 3&S

FMt;^ iititl-n 3tiS

Phv<|>li]|leuf litue 3t)0

Cirin'iiito of liHie 21

CAtboniile of miuptMlA Ifl

Cittoriile of uxlinm i

Acwtal«or«rNli, ^. { ^"^

lOOO

Owing to the large proportion of stonrine in the fatly ingredicnta

«if the sebaceous matters, they have n considernble Jegree of con-

Bislency. Their office is to lubricate th« integument and the hair»,

to keep them sofl and pliable, and to prevent their drying up by

' 8iinon'< CWmUlry of Uan, p. 379*

SECRETIOy.

too rapid cToporntion. When the sebaceous glands of the scalp
are inactive or atrophied, the hairs become dry and brittle, are
easily spHt or brokeD off, and finally cea$e growing altogether.
Tho ccraminous matter of the ear is inteaded without doubt partly
to obstruct the cavity of the meatus, awl by its glutinous consist-
CDCy and strong odor to prevent amall insects from accidentally
introducing themselves into the meatus. The secretion of the
Meiboinian glands, by being smeared on the edges of the eyelids,
prevents the tears from running over upon the cheeks, and confines
them withiu the cavity of the lachrymal canata.

8. Perspiration, — The perspiratory glands of the skin are scat-
tered everywhere throughout the iulvguuient, being most abundant
on the anterior portions of the body. They consist each of a slender
tube, about ^jig of an inch in diamet^^r, lined with glandular epi-
thelium, which penetrates nearly through the entire thicknesa of
the skin, nnd terminates below in a globular coil, very siniilar in

appearance to that of the cerumi-
Fig. 104. nous glands of the ear. (Fig. 104.)

A network of capillary vessels
envelops the tubular coil and sup-
plies the gland with the materials
necessary to its secretion.

These gland.s are very abundant

iu some parts. On the posterior

^~^4:^ portion of the trunk, the cheeks,

(ifSS3S3!4^^ f^Y^^^J " V "^'"^ ^'^^ "^''^ "^ ^^^ thigh and leg

there arc, according to Krause,'
about 500 to the si^uare inob ; on
the anterior part of the trunk, the
forehead, the neck, the forearm,
and the back of the hand and foot
1000 to the square inch; and on
the sole of the foot and the palm
of the hand about 2700 in the same space. According to the same
observer, the whole number of perspiratory glands is not leas than
2,300,000, and the length of each tubular coil, when unravelled^
about Vk of an inch. The entire length of the glandular tubing
must therefore be not leas than 158,000 inches, or about two miles
and a half.

};^

A I'lHIPI NITIIKI OLJlXn, W(tb til ■••■
IDMo.)— a. (iluidiulaTViLL b. PIpiui orTOHelt.

• Eolliker, Hftiidbncli <l«r n«w«lw1«>ir«. Ulpiig, 1$S2, p. 147.

PXK3PIRAT10N. 81S

It is easy to noderstAnd, therefore, that a very large quantity of
fluid may be supplied tivm so extensive a glandular apparatus. It
results from the researches of Lavoisier and Seguin* that the ave-
rage quantity of fluid lost by cutaneous perspiration daring 24
boars ia 18,600 grains, or nearly two pounds avoirdupois. A still
larger quantity than this may be discharged during a shorter time,
when the external temperature is high and the circulation active.
Dr. Southwood Smith* found that the laborers employed in gas
works lost sometimes as much as 8} pounds' weight, by both cuta-
neous and pulmonary exhalation, in less than an hour. In these
cases, as Seguin has shown, the amount of cutaneous transpiration
is about twice as great as that which takes place through the lungs.

The perspiration is a colorless watery fluid, generally with a
distinctly acid reaction, and having a peculiar odor, which varies
somewhat according to the part of the body from which the speci-
men is obtained. Its chemical constitution, according to Ansel-
mine,' is as follows : —

COMFOfllTIOV OF TBI PBR8PIBATI05.

Water 995.00

Aninul nutten, with lime .10

Balphfttes, and sobBtancea solable fo wat«r .... l.OS

Chloiidaa of Bodiam and potassinm, and apirlt-extract . . 2.40

A««tle aoid, acatatea, lactates, and aloohol-extraot 1.46

1000.00
The office of the cutaneous perspiration is principally to regulate
the temperature of the body. We have already seen, in a preced-
ing chapter, that the living body will maintain the temperature of
lOO*' F., though subjected to a much lower temperature by the
surrounding atmosphere, in consequence of the continued genera-
tion of heat which takes place in its interior; and that if, by long
continued or severe exposure, the blood become coaled down much
below its natural standard, death inevitably results. But the body
has also the power of resisting an unnaturally high temperature,
as well as an unnaturally low one. If exposed to the influence of
an atmosphere warmer than 100° F., the body does not become
heated up to the temperature of the air, but remains at its natural
standard. This is provided for by the action of the cutaneous
glands, which are excited to unusual activity, and pour out a large
quantity of watery flutf upon the skin. This fluid immediately

' Hilno Edwarda, Lemons sar la Plijaiologie, &c., vol. ii. p. 623.
' PhilOBoph; of Health, London, 1838, chap. zilL
* Simon. Op. cit., p. 374.

^14

SSCRBTIO^r. '

evnporates, and in assuming the gaseous form caoses so macli heat
to becotiio latent lliat ilie cutaneous surfaces are cooled down to
their natural temperature.

So long ns the air is dry, so that evaporation Trom the surface
can go on rapidly, a very elevated teniperature can be borne with
itiipuoity. The workmen of the sculptor Chantrey were in the
habit, according to Dr. C'arpenttrr, uf entering a furnace in which
the air was heated up to SoO'^ ; and other instances have been known
in whiuh a temperature of 400° to 600° has been borne for a time
without much incnnvenicnce. But If the air be saturated with
moisture, and evaporation from the skin in this way retarded, the
body soon becomes unnaturally warm; and if the exposure be long
contlnueil, death is the result. It is easily seen that horses, when
fast driven, sufTer much more from a warm and moist atmaiphere
than from a warm and dry one. The experiments of Magendie and
others have sbuwn' that quadrupeds eontined ia a dry atmosphere
suffer at flrst but little inconvenience, even when the temperature
ia much above that oF their own bodies; but as soon as the atmo-
sphere is loaded with moisture, or the supply of perspiration is ex-
hausted, the blood becomes heated, and the animal dies. Death
follows in the^e eases as soon as the blood has become heated op to
8** or 9® K., above its nnturol standard. The temperature of 110",
therefore, which is the natural temperature of birds, is fotal to quad-
rupeds; and we have found that frogs, whose natural temperature
ia oO** or 00**, die very soon if they arc kept in water at 100" F.

The amount of perspiration is liable to variation, &a wo have
already intimated, from the variutli^ns in temperature of the sur-
rounding olmosptiere. It is excited also by unusual muscular
exertion, and increased or dirainiaheil by various nervous condi-
tions, such as anxiety, irritation^ lassitude, or excitement.

4. The Tears.— The tears are prot^uced by lobulated glands
situated at the upper and outer part uf ihe orbit of the eye, and
openitig, by frum six to twelve ducts, upon the surface of the con-
junctiva, in the fold between the eyeball and the outer portion of
the upper lid. The secretion is extremely watery in its composition,
and contains only about one part per thousand of solid matters,
consisting mostly of chloride of sodium ^nd animal extractive
matter. The office of the lachrymal secretion is simply to keep the

■

■ fi««nanl, Lwclun* on lh« Blood. AlWe'a traiuUlltiD, p. S&.

TUB MILE.

315

iurfoccs of iho cornea anU conjuDctiva muist aad poliahet^, and to
preserve in this way the tranaparoncy of tbe parta. The tears,
which arc constantly secreted, are spread out uniformly over the
anterior part of the eyeball by the movement of the Uda in wink-
ing, and are gradually conducted to the inner angle of the eye.
Here they are taken up by the puncta lachryinalia, pas3 through
the lachrymal canals, and are 6nally diacharged into the nasal pas-
sages beneath the inferior turbinated bones. A constant supply of
frodh ftuid id thua kept passing over the tran^tparent parta of the
eyeball, and the bod re;sult3 avuided which would follow from iu
aocamulation and putrefactive alteration.

6. The Milk.— The mammary glands are conglomerate glands,
resembling closely io their structure tlie pancreas, the salivary, and
tbe lachrymal glands. They consist of nnmerous secreting sacs or
follicles, grouped together in lobules, each lobule being supplied
with a common excretory duct, which Joins those coming from
»ljacent parts of the gland.

(Fig. lOu.) In thia way, by Kig.ios.

their succeaaivo union, they

form larger branches and

IraDJCfl, until they are reduced

in Dumbers tofiome 15 or 20

cylindrical ducts, the Uiciifer-

€rvu duels, which open finally

Ijy as many minute orilicea

xi^>on the extremity of the

nipple.

Tbe secretion of the milk

l>ecomes fairly established at

t. he end of two or three days

sKfter delivery, though the ni.*>»i-<.*B st«eoT«aaar u^ni*.

k* reaata often contain a milky

fluid during the latter part of pregnancy. At first the Quid dis-
charged from the nipple is a yellowish turbid mixture, which is

called the colostrum. It has the appcnrancc of lacing thinner than
the milk, but chemical examinations have shown' that it really cod*
Uitiaa larger amount of solid ingredienta than the perfect secre-
tiuQ. When examined under the microscope it is seen to contain.
Wide the tuilk-globults proper, a large amount of irregularly glu-

M^'^

* Li<bat4na, op. cit., rol. H. p. U3.

S16

SBCRBTIOir.

»0

biilar or oval bodies, from j^j, to jSb of an inch in diameter,

which are termed the "colostrum corpuscles." (Fig. 106.) Theie

• bodies are more jellov and
F'K* 106. opaque thau the true milk-

globules, OS well as beingrer;
mucli larger. They have a
well defined outline, and ooo*
flist apparently of a group of
minute oily granules or glo-
bules, imbedded in a mass
of organic substance. The
milk-globules at this time
are less abundant ilian after-
ward, and of larger size,
measuring mostly from j^t
^ Tg"oiF of an inch io dja*
meter.

At the eod of & day or
two after its first appearance,

the colostrum ceases to be discharged and is replaced by the troe

milky secretion.
The milk, as it is discharged from the nipple^ is a white^ opvjoe

fluid, with a slightly alkaline reaction, and a specific gravitj of

about 1030. Its proximate chemical constitution, aocordiog to

Pcroira and Lchmann, is as follows: —

CvLDnrKi'H Con PI.-K- ■■«■. vti ti nitlk-flubiila
A'«n ft ir«nia[i. one d^y kftei ddlHrf.

Co)ir<MiTioii OF Cow'r Mii.i

Wawr

CaMio

Butt«r

Buj^ar

So<i«

Chloride* of flodinm xnul potasriinm .
PbnspliatM rtf <iM(i anil patftua .
Phoaphjile of lime

« " magnMU

" "Iron

Altuline onrbonat«fl ■•....

S70.3

31.3

«.7

«.»

looa-ft

Human milk ia distinguished from the above by containing leai
casein, and a larger proportion of oily and saccharine iDgredieota
The entire amount of solid ingredients is also somewhat less thu
in cow's milk.

THB MILK.

S17

Tlie catein is one of tbe moBt important ingredients of tbe milk.
It is an extremul^ nutritious organic subHtanco, whidi is hekl in a
fluiJ form by union wIlH the water of the Becretioo. Casein is not
coagnlable by heat, and consequently, milk may be boiled without
changing iu consistency to any considerable extent. It becomes
a little thinner and more fluid during ebullition, owing to tbe melt-
ing of its oleaginous ingredients; and a thin, membranous film
forms upon ita surface, consisting probably of a very little albumen,
which the milk contains, mingled with the caseiu. The addition of
any of tbe acids, however, mineral, animal, or vegetable, at once
coagulates the casein, and the milk becomca curdled. Milk is
ooagulatcd, furthermore, by the ga^triu juice in the natural process
of digestion, immediately afUr being taken into tlie stomach ; and
if vomiting occur soon after a meal contaiuiug milk, it is throwu
uff in the form of semi-solid, curd-like flakes.

The mucous membrane of the calvc.4' stomach, or rennet, also
has the power of coagulating casein ; and when milk has been
curdled in this way, and it<t watery, saceharine, and inorganio in-
gredients separated by mechanical pressure, it is converted into
cheese. The peculiar flavor of tbe din'oreat variutlos of cheese
depends on tbe quantity and quality of the oleaginous ingredients
which have been entangled with the coagulated casein, and on the
alterations which these sub-

staooea have undergone by ^8- *o7.

the lapse of ume and ex-
posure to the atmosphere.

The sugar and saline sub-
stances of the milk are in
fiolution, together with the
casein and water, forming a
clear, colorless, homogene-
ous, serous fluid. The but-
ter, or oleaginous ingredient,
howercr, is suapended in
this serous Huid in the form
of miouta granules and
globules, the true " milk-
globules." (Fig. 107.) These
gk)bules are nearly fluid at
the terafierature of the body, and have a perfectly cirtiular out-
line. In the perfect milk, they are very much more abundant and

(0^0

o^-b

80?

cPo

pOQ

'0»,

O D

^6)l9JPVfS^2o

,000

^cfO^

p'O'

t^°AloX'o'J:o°;&>

•b^,

0«Q

ooo?o o«

"■ O O * *

O 0,

. Oft „ o o

OSQ

°6-o
I O o

iOo

(our d>r* kXxdnltvMT. SMrtttom fuHj MiablliliBd.

818 8KCRETI0K.

smaller inside than in tbe colostrum; as the largest or them are'
not over joVc of an inch in diameter, aiid the greater number
about jnion of an inch.

The following is the comf>08ition of the hotter of cow's milli,
according to Kobin aod Verdeil : —

Margarine 66

OWw 30

BuiyriBQ 2

It is iho last of these ingredients, the butjrine, which gives itidj
peculiar flavor to the butter of milk.

The railk-globoles hare sometimes been described as if each one
were separately covered with n thin layer of coagalated casein or
albumen. No such investing membrane, however, is to be seen.
The milk-globules are simply small masses of semi-fluid fat, sus-
pended by admixture in the watery and serous portions of tbe
secretion, bo as to make an opaqae, whitish omolsion. They do
not fuse together when they come in contact under the microscope,
simply because they are not quite flnifl, but contain a large pro-
portion of margarine, which is solid alonlinary temperatures of the
body, and is only retained in a partially fluid form by tbe oleine
with which it is associated. The globules may be made to fuse with
each other, however, by simply heating the milk and subjecting it
to gentle pressure between two slips of glass. ■

When fresh milk is allowed to remain at rest foi* twelve to twenty- ■
four hours, a large portion of its fatty matters rise to the surface, V
and form there a dense and rich-looking yellowish-white layer, ihe
cream, which may be removed, leaving the remainder still opaline,
but less opaque than before, At the end of thirty-six to forty-eight
hoars, if the weather be warm, the casein begins to take on s fl
putrefactive change. In thia condition it exerts a catalytic action 9
upon the other ingredients of the milk, and particularly upon the M
sugar. A pure watery solution of niilk-sugar (Cj^„0^) may bef
kept for an indefinite length of time, at ordinary temperatures,
without undergoing any change. But if kept in contact with the
partially altered casein, it Buftera a catalytic transformation, and is
converted into lactic acid (Cgll^Oo). This unites with the free soda, ■
and decomposes the alkaline carbonates, forming tactiites of sodafl
and potassa. After the ncutralizntioQ of these substances has beenfl
accomplished^ the mitk loses its alkaline reaction and begins to tumfl
sttur. The free lactic acid then coagulates the casein, and tbe milk

SECRKTIOK OF THE BILE. 819

ii curdled. The sltered organic matter also acta upon the olea-
ginoos ingredieotB, which are partly decomposed; and the milk
begins to give off a rancid odor, owing to the development of
various volatile fatty acids, among which are butyric acid, and the
like. These changes are very much hastened by a moderately
elevated temperature, and also by a highly electric state of the
atmosphere.

The production of the milk, like that of other secretions, is liable
to be much influenced by nervous impressions. It may be increased
or diminished in quantity, or vitiated in quality by sudden emo-
tions; and it is even said to have been sometimes so much altered
in this way as to produce indigestion, diarrhcea, and convulsions in
the infant.

Simon found' that the constitution of the milk varies from day to
day, owing to temporary causes; and that it undergoes also more
permanent modidcationa, corresponding with the age of the infant
He analyzed the milk of a nursing woman during a period of nearly
six months, commencing with the second day after delivery, and
repeating his examinations at intervals of eight or ten days. It
appears, from these observations, that the casein is at first in small
quantity; but that it increases during the first two months, and
then attains a nearly uniform standard. The saline matters also
increase in a nearly similar manner. The sugar, on the contrary,
diminishes during the same period; so that it is less abundant in
the third, fourth, fifth and sixth months, than it is in the first and
second. These changes are undoubtedly connected with the in-
creasing development of the infant, which requires a corresponding
alteration in the character of the food supplied to it Finally, the
qoandty of butter in the milk varies so much from day to day,
owing to incidental causes, that it cannot be said to follow any
r^ular course of increase or diminution.

6. Secretion of the Bile. — The anatomical peculiarities in the
rtructnre of the liver are such as to distinguish it in a marked
degree from the other glandular organs. Its first peculiarity is
that it is furnished principally with venous blood. For, although
it receives its blood from the hepatic artery as well as from the
portal vein, the quantity of arterial blood with which it is supplied
u extremely small in comparison with that which it receives from

' Op. cit,, p. 337.

320

SBCRBTIOX.

the portal system. The blood which has circniatcd throngh tli4
capillnries of the stomach, spleen, pancreas, and jnlestine is col'
lected by the roots of the corresponding veins, and diacbarged into
the portal rein, which enters the liver at tlio great transverse
fissure of the organ. Immediately upon its entrance, the portal
vein divides into two branches, right and left, which supply tlie
corresponding portions of the liver; and these branches sucoesaa
ively subdivide into »mnller twigs and ramiGcations, until they are
reduced to the size^ according to KuUikcr, of f aVo "^ ^^ ''^^^^ '^
diameter. These veins, with tlieir terminal branches, are arranged
in such a manner as to include between thero pentagonal or
hexagonal spaces, or portions of the hepatic eubatance, ,"» to j'j
of an inch in diameter in the human subject, which can readily be
distinguished by the naked eye, bulb on the exterior of the organ
and by the inspection of cut surfaces. The portions of hepatio
substance included in this way between the terminal branches

ot the portal vein (Fig. 108)
''«'*°^' are termed the "acini" or

"lobules" of the liver; and
the terminal venous brauebes,
occupying the spaces between
the aOjacetit lobules, are the
"interlobular" veins. In the
spaces between the lobules
we also 6Dd the minute
branches of the hepatic ar-
tery, and the commencing
rootlets of the bepntic duds.
Aa the portal vein, the he-
patic artery, nod the hepatic
duct enter the liver at the
transverse fissure, they are
closely invested by n fibrous
sheath, termed Glisson's capsule, which accompanies ihem in their
divisions and ramifications. In some of the lower animals, as in the
pig, this sheath extends even to the interlobular spaces, iDcloeiog
each lubule in a thin fibrous investment, by which it is distinctly
separated from the neighboring p&rta. In the human subject, how-
ever, Glisson's capflulc becomes gradually thinner as it penetrates
the liver, and disappears altogether before reaching the interlobular
spaces; so that here the lobules are nearly in contact with each

Bimlllcadoa of PohTjII. Vma in llTfi— «.
Twig vfiunsl vela b,6, tiiierlub(t1>Tr*(Da. r Adul,

tS BILE.

821

other by their adjacent surfaces, being separated only by tbe inter-
lobular veins and the minute branches of tbe hepatic artery and
duct previously mentioned.

From the sides of the interlobular veins, and also from their
terminal extrcmilica, there are given off capillary vessels, which
penetrate the substance of each lobule and couverge from its cir-
cumrerence toward its centre, inosculating at the same time freely
with each other, so as to form a minute vascular plexus, the 'iobu-
lar" capillary plexus. (Fig. 109.) At the centre of each, lobule, the

Pig. 109.

UiBKLS nv LiTia, aliovlBj dUtrtbulion at bloadieaiMh; aiasnllloid t3(llaiaBl«ni.~4,(L t»-
brtatalar wIbb. t. iDtrsUbatBr vain. c. f, e. Loticlkr npillar)r piioxtim <I, 4. T^lg* vf lbl«r-

converging capillaries unite into a small vein (b), the "intralobu-
lar" vein, which is one of tbe commencing rootlets of the hepatic
vein. These rootlets, uoiting succosaively with each other, so an
u> form larger and larger branches, Anally loave the liver at its
poMterior edge, to empty into the ascending vena cava.

Beside the capillary bloodveaacla of the lobular plexus, eacb
acinus is made up of an abundance of minute cellular bodies, about
(/oo of an iuch in diameter, tbe "hepatic cells." (Fig. 110.) These
uelk have an irregularly pentagonal Bgure, and a soft consistency.
They are composed of n homogeneous organic subntjince, in tbe
midst of which arn imbedded a large number of minute granules,
and generally several well defined oil-globules. There is also a
round or oval nucleus, with a nucleolus, imbedded in the substance
21

822

JJECRKTION.

Fig. 110.

of ihc ceH, sotnetvmea more or less obaourcd by the granales anc
oil drops with which it ia surroanded.

The exact modo io which these cclla are connected with the
hepatic duel was for a long time the most obscure point ia tho'l

minute nnatomj of the liver.
It has now been ascertained,
however, bythc researches of
Dr. Leidy, of Philadelphia.'
and Ur. Beale, of Londou,'
that they are reallycontained
in the interior of secreting
tubules, which pass oft* from
thesmaller hepatic dacts, and
penetrate everywhere the
substance of the lobulee.
The cells fill nearly or com-
pletely the whole cavity of
the tubules, and the tubules
themselves lie in close proxi-
mity with each other, so as
to leave no space between thera except that which is occupied by
the capiltnry bloodveasela of the lobular plexus.

These cells arc the active agents In accomplishing the function of
the liver. It is by their influence that the blood which ia brought
in contact with them supers certain changes which give rise to the
secreted pruduct» of the organ. The ingredients of the bite first
make their appearance in the substance of the cells. They aro J
then, transuded from one to the other, until they are at last dis-
charged into the small biliary ducts seated in the interlobular
spaces. Kach lobule of the liver must accordingly bo regarded as
a mass of secreting tubules, lined with glandular cells, an<l invested
with a close network of capillary bloodvessels. It foilowi>, there-
fore, from the abundant inosculation of the lobular capillaries, and
the manner In which they are entangled with the hepatic tissue,
that the blood, in passing through the circulation of ihe liver,
comes into the most, intimate relation with the glandular cclU of
the organ, and gives up to them the nutritious materials which are
afkerward converted into the ingredients of the bile.

BsPATic Crli.*. Ptsb Ibabamiio aiibJooL

' Am^riraii J'jurtinl Itinl. Sci., Jaiiunrr, 1648.

' tin ^tno I'liiiiU in llie Minute dnntom/ o( llie Liver.

Loudon, l(>66.

EXCRSTIOH. S23

CHAPTER XVII.

EXCRETION.

Ws have now come to the last diviBion of the great nutritive
fiiBCtion, viz., the process of excretion. In order to understand fairly
the natnre of this process we must remember that all the component
parts of a Uving oi^nism are necessarily in a state of constant
change. It is one of the essential conditions of their existence and
activity that they should go through wi^ this incessant transforma-
tion and renovation of their component substances. Every living
animal and vegetable, therefore, constantly absorbs certain materials
from the exterior, which are modified and assimilated by the pro
cess of nutrition, and converted into the natural ingredients of the
organized tissues. But at the same time with this incessant growth
and sapply, there goes on in the same tissues an equally incessant
prooeaa of waste and decomposition. For though the elements of
tbe food are absorbed by the tissues, and converted into musculine,
usteine, hsematine and the like, they do not remain permanently in
this condition, but almost immediately begin to pass over, by a con-
Uhoance of the alterative process, into new forms and combinations,
which are destiped to be expelled from the body, as others continue
to be absorbed. Thus Spallanzani and Edwards found that every
oi||;anized tissue not only absorbs oxygen from the atmosphere
and fixes it in its own substance; but at the same time exhales
carbonic acid, which has been produced by internal metamorphosis.
This process, by which the ingredients of the organic tissues, al-
nady formed, are decomposed and converted into new substances,
IB called the process of Destructive Ammilation.

Accordingly we find that certain substances are constantly mak-
ing their appearance in the tissues and fluids of the body, which
did not exist there originally, and which have not been introduced
with the food, but which have been produced by the process of in-
ternal metamorphosis. These substances represent the waste, or
physiological detritus of the animal organism. They are the forms

BTCRKTTOIT.

under whicli those materials present themselves, which have once
formed a part or the living tissue, but which have bcoomo altered
by the incessant changes characteristic of organized bodies, and
which are consequently no longer capable of exhibiting vital pro-
perties, or of performing the vital functions. They are, therefore,
destined to be removed and discharged from the animal frame, and
are known accordingly by the name of Sxeremmtitious Substances.

These excrementitioua aubsiances have peculiar characters by
which ihey may be distinguished from the other ingredients of the
living body; and they might, tberefure, be made to constitute a
fourth claHs of proximate principles, in addition to the three which
we hare enumerated in the preceding chapters. They are all sub-
stances of definite chemical composition, and all susceptible of
crystallization. Some of the most important of them contain nitro-
gen, while a few are non-nitrogenous in their composition. They
originate in tlie interior of living bodies, and are not found else-
where, ejicept occasionally as the result of decomposition. They
are nearly a1! suluble in water, and are soluble without exception in
the animal fluids. They are formed in the substance of the tiasnea,
from which tliey are absorbed by the blood, to be afterward conveyed
by the circulating fluid to certaio excretory organs, particularly the
kidneys, from which they are Hoally discharged and expelled from
the body. This entire process, made up of the production of the
cxcrcmenlitioQS substances, their absorption by the blood, and their
linal elimination, is known aa the process of excretion.

The importance of this process to the maintenance of life is readily
shown by the injortons eAects which follow upon its disturbance.
If the discharge of the excrementitious substances be in any way
impeded or suspended, these substances accumulate, either in the
blood or in the tissues, or in both. Id couaequence of this reteottoQ
and accumulation, they become poisonous, and rapidly produce a
derangement of the vital functions. Their influence is principally
exerted upon the nervous system, through which they produce
most frequently irritability, disturbance of the special senses^ deli-
rium, insensibility, coma, and Bnally death. The readiness with
which these efl'ecis are produced depends on the character of the
excrementitious substance, and the rapidity with which it is pro-
duced in the body. Thus, if the elimination of carbonic acid be
stopped, by overloading the atmosphere with an abundance of the
same gas, death takes place at the end of a few minutes; bat if the
elimination of urea by the kidneys be checked, it requires three or

UREA. 826

foar days to produce a fatal result. A fatal result, however, is cer-
tain to follow, at the end of a longer or shorter time, if any one of
these substanoes be compelled to remain in the body, and accumu-
late in the animal tissues and fluids.

The principal excrementttious substances known to exist in the
hamao body are as follows: —

1. Carbonloaeid C<^

2. CbolMtaiiae CjiHuO

3. D«» C,H,NiO,

4. CresUiM C^H^,0«

b. CreatinfDa C,H,N,0,

6. Crate of Bodft NaO,C,HN,Orf HO

7. Drato of poUiia .... KO,C,HN,0(

8. Urats of ammooia .... NH^OiSCtHNgOr^-HO

Of these substances the first two have already been studied at
eafficient length in the preceding chapters. We will merely repeat
here that carbonic acid is produced in large quantity in nearly all
the tissues of the body, from which it is absorbed by the blood,
conveyed to the lungs, and there exhaled at the same time that
oxygen is al»orbed. Cholesterine.is a non-saponifiable fatty sub-
stance, originating in the brain and spinal cord, in the tissue of
which organs it exists in the proportion of 68 parts per thousand.
It is thence taken up by the blood, conveyed to the liver and dis-
charged with the bile. Cholesterine is extremely insoluble in
water, but is held in solution in the blood and the bile, by some of
tbe other ingredients present in these animal fluids.

The remaining excrementitious substances may be examined
together with the more propriety, since they are all ingredients of
anngle excretory fluid, viz., the urine.

Ursa. — This is a neutral, crystallizable, nitrogenous substance,
very readily soluble in water, and easily decomposed by various
external influences. It occurs in the urine in the proportion of SO
parts per thousand; in the blood, according to Picard,' in the pro-
portion of 0.016 per thousand. The blood, however, is the source
from which this sabstance is supplied to the urine; and it exists,
accordingly, in but small quantity in the circulating fluid, for the
reason that it is constantly drained off by the kidneys. But if tbe
kidneys be extirpated, or the renal arteries tied, or the excretion
of arine suspended by inflammation or otherwise, the urea then

■ Id UilDfl Edwards, Le^na aar la Pbjaiologie, &c , vol. t. p. 297.

326

BXCRITIOI

l?,:i

c:^/

accumulates in tTie blooti, and presents itself there in conaiderable
quatiiity. It has bw;ti founO in the blood, under these cireom-
sutuccs, in the [iroportion of 1.4 per thoufiand.' It is not yet known

from what source the urea iafl
^* ^^** originally derived; whether it

be prcxluced in the blood itaclf,
or whether it be formed in some
of the solid tissues, and thcnco
taken up by the blood. It has
not yet been found, however,
in any of the solid tiiauas, in a
state of health.

Urea isobtained most readily I
from the urine. For this pur-
pose the fresh urine is evapo-
rated in the water bath until it]
baa a syrupy consistency. It]
is then mixed with an equal,
volume of nitric acid, which]
forms nitrate of urea. Thi.s salt, being lej» soluble than pure urca,j
rapidly crystallizes, after which it is separated by 61tration from<
the other ingredients. It is then dissolved in water and deoom-;
posed by carbonate of lend, forming nitrate of lead which romalna
in solution, and oarbonio acid which escapee. The solution is then
evaporated, the urea dissolved out by alcohol, and finally crystal-
lized iu a pure state.

Urea has no tendency to spontaneous decomposition, and may
be kept, when perfectly pure, in a dry Biato or dissolved in water,
for an indefinite length of time. If the watery solution be boiled, _
however, the urea is converted, during the process of ebullition,'^
tato carbonate of aitimonia. One equivalent of urea unites with
two equivalents of water, and becomes transformed into two equiva- ,
lents of carbonate of ammonia, as follows: —

rB|4, pnnt-tDi] tnini ariar, ■nit cryitBlUml hj

C,H,N,0,=L'r*».

Various impurities, also, by acting as catalytic bodies, wtU
duco the same change, if water be present. Animal substances in
a state of commencing decomposition are particularly liable to aet^

' Robiu uid Vvnlvit, col. U. p. fi02.

UREA. 127

iii this way. Tn order that the conversion of the urea be thus pro-
dooed, it is necessary that the temperature of the mixture be not
far from 70° to 100" F.

The quantity of urea produced and discharged daily by a healthy
adult is, according to the experiments of Lehmann, about 600
grains. It Taries to some extent, like all the other secreted and
<xcreted products, with the size and development of the body.
XehmAtin, in experiments on his own person, found the average
daily quantity to be 487 grains. Prof. William A. Hammond,'
"who is a very large man, by similar experiments found it to be
470 grains. Dr. John C. Draper* found it 40B grains. No urea is
to be detected in the urine of very young childreu,-' bat it soon
anakes ita appearance, and afterward increases in quantity with the
development of the body.

The daily quantity of urea varies also with the degree of mental
and bodily activity. Lehmann and Hammond both found it very
sensibly increased by muscular exertion and diminished by repose.
It has been thought, from these facts, that this substance must be
directly produced from disintegration of the muscular tissue. This,
liowever, ia by no means certain ; since in a state of general bodily
activity it is not only the urea, but the excretions generally, carbonic
aoid, perspiration, &c^ which are increased in quantity simultane-
ooaly. Hammond has also shown that continued mental applica-
tion will raise the quantity of urea above its normal standard,
though the muscular system remain comparatively inactive.

The quantity of urea varies also with the nature of the food.
Lehmann, by experiments on his own person, found that the quan-
tity was larger while living exclusively on animal food than with
a mixed or vegetable diet ; and that its quantity was smallest when
confined to a diet of purely non-nitrogenous substances, as starch,
wigar, and oil. The following table* gives the result of these ex-
perimenta

KiMD OF Food. Dailt Qdaktitt of Uhba.

Animal 798 graiiu.

Mixed 467 "

Vrgetable 337 "

Non-nitrogenooH 231 "

t Amerioan Joarnal Ued. Sol., Jan., IHSS, and April, 1856.
■ N«w York Jonrnal of Medicine, Harob, 1856.

* Robin and Verdeil, vol. ii. p. 500.

* Lebmann, op. oit., vol. ii. p. lt!3.

5S8

BXCHRTIOK.

Finally, it has been sbowa by Dr. John C. Dmper' that there is
also a diurnal variation in the norma] quantity of urea. A smaller
quantity ib produced during the night than during the day; aod
this difference exists even in patients who ere confined to the bed
during the whole twenty-four hours, as in the case of a man under
treatment for fracture of the leg. This ia probably owing to the
greater activity, during the waking hours, of both the mental and
digestive functions. More urea ia produced in the latter half than
in the earlier half of the day; and the greatest quantity is dis-
charged during the four hours from 6J to lOJ P. M.

Urea exiata in the urine of the carnivorous and many of the
herbivorous quadrupeds; but there is little or none to be found in
that of birds and reptiles.

Crsatine. — This is a neutral cryatallizable substance, found in
the muscles, the blood, and the urine. It is soluble in water, very

slightly soluble in alcohol, and
Fig' 112> not at all m in ether. By boil-

ing with an alkali, it is either
converted into carbonic acid
and ammonia, or is decomposed
with the production of urea and
an artificial nitrogenous crys-
tallizable substance, termed sar-
coaine. By being heated with
strong acids, it loses two equiva-
lents of water, and is oonverted
into the substance next to be
described, viz., creatinine.

Creatine exists in the urine,
in the human subject, in the
proportion of about 1.25 parts,
and in the muscles in the proportion of 0.67 parts per thousand.
Its quantity In the blood has not been determined. In the muscu-
lar tissue it is simply in solution in the interstitial fluid of the pariA,
so that it may be extracted by simply cutting the muscle into
small pieces, treating it with distilled water, and subjecting it to
l>ressiirc. Creatine evidently originates in the muscular tissue, is
absorbed llience by the blood, and is finally discharged with the
urine.

■ Lw. tAi.

CNiiATi]i|[,crT>ln1Jlt*iirr.>u] bm trXnr

(After

I
I
I

CREATISIXl— CRATB OF SODA.

Cbeatinink. — This is also a crystallizable sabstance. Tt differs
in compoailion from creatine by containing two equivalents le«8 of
the elements of water. It Is more soluble in water and in spirit
than creatiue, and dissolves sliglitlj also in ether. It hru) a dis-
tinctly flliiallnD reaction. It occurs, like crcaiino, in the muaclcA,
the blood, and the urin6; and

is undoubtedly first produced '*• US-

in the muscular tlsfluo, to be
discharged finally by the kid-
neys. It is very possible that
it originates, not directly from
the muscles, but indirectly, by
transformation of a part of the
creatine; since it may be arti-
ficially produce*!, as we have
already mentionod, by trans-
formation of the latter substance
under the influence of strong
acid?, and since, furthermore,
vrbilecreatine is more abundant
in the muscles than creatinine,

in the urine, on the contrary, there is a larger quantity of creatinine
than of creatine. Both these subHtnnccrs have been fouud in the
muscles and in the urine of the lower animals.

lAfi^r IfbDiiioa.)

■lOT

Ubate or Soda. — As its name implies, this suKstance is a neu-
tral salt, formed bj the union of soda, as a base, with a utlrogenoos
inimal acid, viz., uric ncirf (CjUNjO^UO). Uric acid is sometimes
i^Hiken of as though it were itself a proximnte principle, and a
constituent of the urine; but it cannot properly be regarded as
Rich, since it never occurs in a free state, in a natural condition of
the fluids. When present, it has always been produced by decom-
{Kpsition of the urate of soda.

Urata of soda is readily soluble in hot water, from which a large
portion again deposits on cooling. It io slightly soluble in alcohol.
and insoluble iu ether. It crystallizes in small globular mas.=)e8,
with projecting, curved, conical, wartlike excrescences. (Fig. 114,)
It dissolves readily in the alkalies; and by most acid solutions it
is decomposed, with the production of free uric acid.

Urate of soda exists in the urine and in the blood. It is either
produced originally in the blood, or is formed in some of the solid

330

BXCBBTIOK.

tiKiQ&s, nnd alMorbed from them by the circulating fluicl. Il t» coo-
statitly L'liiniuated by the kidneys, in company with the other ingre-
dients uf the urine. The
'''*■ ^**' average daily quantity of

urate of soda diacharged by
the healthy human subject Js,
accord ingU) IxhTnann,aboot
25 grains. This substance
c^iats in the urine of the car-
nivorous and omoivoroua
animals, but not in that of
the herbivora. In the latter,
il is replaced by another sub*
9tnnce, difTering somewhat
from it iu couipositioii and
properiie3, viz., hippurate of
soda. The urine of herbi-
vora, however, while stiU
very young, and living upon the milk of the mother, has been found
to contain urates. But when the young animal is weaned, and be-
comes herbivorous, the urate of soda diaapijearB, and ia replaced by
the hippurate.

17»AT>ep Boti«; frnma arlntrr d«po>IL

Urates of Potassa and Ammosia. — The urates of polassa awl
aminonia resemble the preceding salt very closely ia their phy.iJo-
logical relations. Thoy are formed in very much smaller quantity
than the urate of eodn, and appear like it as ingredients of the urine.

The siibsiances aV>ove enumerated closely resemble each other in
their most striking and important characters. They alt contain
nitrogen, are all crystallizable, and all readily soluble in water.
They all ori^-inate in the interior of the body by the decomposition
or catalytic tranaibrmntion of its organic ingredients, and are all
conveyed by the blood Co the kidneys, to be finally expelled with
the urine. These are the substances which represent, to a great
extent, the fin.il tran-sformaiion of the organic or albuminoid in-
gredients of the tissues. It has already been mentione<l, in a pre-
vious chapter, that these organic or albuminoid substanoes are not
discharged from the body, under their own form, in quantity at all
proportionate to the abundance with which ihey are introduced.
By far the greater part of the m.i3s of the frame is made up ofj
organlu subdtiitices : albumen, niusculiue, ustelne, ko. tSimilar

OKNKBAL CHABACTSBS OF THE URINE. SSI

materials are taken daily in large qnaDtitj with the food, in order
to supply the nutrition and waste of those already composing the
^aes; and yet only a very insignificant quantity of similar
material is expelled with the excretions. A minute proportion of
Tolatile animal matter is exhaled with the breath, and a minute
proportion also with the perspiration. A very small quantity is
discharged under the form of mucus and coloring matter, with the
orine and feces; but all these taken together are entirely insuffi-
cient to account for the constant and rapid disappearance of organic
matters in the interior of the body. These matters, in fact, before
being discharged, are converted by catalysis and decomposition into
new substances. Carbonic acid, under which form 3500 grains of
carbon are daily expelled from the body, is one of these substances;
the others are urea, creatine, creatinine, and the urates.

We see, then, in what way the organic matters, in ceasing to form
a part of the living body, lose their characteristic properties, and
are converted into crystallizable substances, of definite chemical
composition. It is a kind of retrograde metamorphosis, by which
-they return more or less to the condition of ordinary inorganic
materials. These excrementitious matters are themselves decom-
posed, afler being expelled from the body, under the inBuence of
the atmospheric air and moisture; so that the decomposition and
destruction of the organic substance are at last complete.

It will be seen, consequently, that the urine has a character
altogether peculiar, and one which distinguishes it completely
from every other animal fluid. All the others are either nutritive
fluids, like the blood and milk, or are destined, like the secretions
generally, to take some direct and essential part in the vital opera-
tions. Many of them, like the gastric and pancreatic juices, are
reabsorbed afler they have done their work, and again enter the
current of the circulation. But the urine is merely a solution of
excrementitious substances. Its materials exist beforehand in the
circulation, and are simply drained away by the kidneys from
the blood. There is a wide difiterence, accordingly, between the
action of the kidneys and that of the true glandular organs, in
which certain new and peculiar substances are produced by the
action of the glandular tissue. The kidneys, on the contrary, do
not seorete anything, properly speaking, and are not, therefore,
glands. In their mode of action, so far as regards the excretory
function, they have more resemblance to the lungs than to any
other of the internal organs. But this resemblance is not complete;

KICBBTTOS.

since tbc lungs perform a double Tunction, Absorbing oxygen at tbe
same time tlint they exlinle carbonic acid. The kidneys alone are
purely excretory in their olTice. The urino is noi intended to
fulfil any function, mecbanical, chemical, or athervrise; but is des-
tined only to bo eliminated and exp(;lle<1. Since it possesses so
|xx:ulinr and impurlant a character, it will require to be carefully
studied in detail.

The un'ne is a clear, watery, amber-cotored fluid, with a distinct
acid reaction. It has, while still warm, a peculiar odor, which dis-
appears more or less completely on cooling, and returns when the
urinu is gently heated. The ordinary quantity of urine discharged
daily by a healthy adult is about Sxxxv, and its mean specific
gravity, 1024. Both its total quantity, however, and its mean
specific gravity are liable to vary somewhat from day to day, owing
to the diflereitt proportions of water and solid ingredients entering
into its constitution. Ordinarily the water of the urine is more
tbau sufficient to bold all its solid matter in solution; and its pro-
portion may therefore be diminished, by accidental causes without
the urine becoming turbid by the formation of a deposit Under
such circumstances, ic merely becomes deeper in color, and of a
higher specific gravity. Thus, if a smaller quantity of water than
usual be taken into the system with the drink, or if the fiuid ex-
halations from the lungs and skin, or the intestinal discharges, be
increased, a smaller quantity of water will necessarily pass off by
the kidneys; and the urine will be diminished in quantity, while its
specific gravity is increased. We have observed the urine lo be
reduced in this way to eighteen or twenty ounces per day, its specific
gravity rising at the same time to 1030. On the other hand, if the
fluid ingesta be unusually abundant, or if the pcrspirntion be dimi-
nished, the surplus quantity of water will pass off by the kidneys; so
that the amount of urine in twenty-four hours may be increased to
forty-five or forty-six ounces, and its specific gravity reduced at
the same time lo 1020 or even I0L7. Under these conditions the
total amount of solid matter discharged daily remains about the
same. The changes above mentioned depend simply upon tbe
fluctuating quantity of water, which may pass off by the kidneys
in larger or smaller quantity, accordingto accidental circumstances.
In these purely normal or physiological variations, thepcfore, the
entire quantity of the urine and its mean specific gravity vary
always in an inverse direction with regard to esch other; tbe former
increasing while the latter diminishes, and vice vcrad. It^ however, it

DIUBNAL VARIATIONS OF THE URINE. 833

sbould be found that both the quantity and specific gravity of the
anoe were increased or diminished at the same time, or if either
ODO were increased or diminished while the other remained station-
ary, such an alteration would show an actual change in the total
amount of solid ingredients, and would indicate an unnatural and
pathological condition. This actually takes place in certain forms
of disease.

The amount of Tariation in the quantity of water, even, may be
so great as to constitute by itself a pathological condition. Thus,
in hysterical attacks there is sometimes a very abundant flow of
limpid, nearly colorless urine, with a specific gravity not over 1U05
or 1006. On the other hand, in the onset of febrile attacks, the
quantity of water is oflen so much diminished that it is no longer
sufficient to retain in solution all the solid ingredients of the urine,
and the urate of soda is thrown down, after cooling, as a fine red
or yellowish sediment. So long, however, as the variation is con-
fined within strictly physiological limits, all the solid ingredients
are held in solution, and the urine remains clear.

There is also, in a state of health, a diurnal variation of the urine,
both in regard to its specific gravity and its degree of acidity.
The urine is generally discharged from the bladder five or six
times during the twenty-four hours, and at each of these periods
showB more or less variation in its physical characters. We have
found that the urine which collects in the bladder during the
night, and is first discharged in the morning, is usually dense,
highly colored, of a strongly acid reaction, and a high specific
gravity. That passed during the forenoon is pale, and of a low
specific gravity, sometimes not more than 1018 or even 1015. It
is at the same time neutral or slightly alkaline in reaction. Toward
the middle of the day, its density and depth of color increase, and
its acidity returns. All these properties become more strongly
marked during the afternoon and evening, and toward night the
urine is again deeply colored and strongly acid, and has a specific
gravity of 1028 or 1030.

The following instances will serve to show the general characters
of this variation : —

OBSBRVATins First. March 20th.
Urine of IM discharge, acid, sp. gr. 1025.
" 2d " alkaliae, " 1015.

" 3d " neutral, " 1018.

" 4th " acid, " 1018.

" 5th " acid, " 1027.

334

EICBETIO:r.

OHBBVATIOXStOONn. Sliirtk 21«(.

Urino of Itt disohatgv, acl'l, ip. gr. 10S9.

•* 2d '• nsBiral, - 1022.

" 3A " TjfiitTfcl. " U'2a.

» 4tb ■• add, " 1027.

'■ 5th " nciii, " \0S0.

TbcM variations do not always follow the [Kjrfectly regular
courae nianifef^tcd in the above instances, since they are somewhat
liable, as wo have already mentioned, to temporary modiGcation
rrotn accidental causes during the day; but their geQeral teadeocy
nearly always corresponds with that given above.

It is evident, therefore, that whenever we wish to test the specific
gravity and acidity of the urine in cases of disease, it will not be
suQicieiU to examine any single specimen taken at random; but all
the different portions discharged during the day should be collected
and examined together. Otherwise, we should incur the risk of
regarding as a permanently morbid symptom what tnight be
nothing more than a purely accidental and temporary varialioa.

The c^iemicat comtitution of the urine as it is discharged from the
bladder, according tu the analyses of Derzelius, Lehmano, Becquerel,
and others, is as follows: —

CoMPosinox or TUX Uxixx.

Wit« S3?.O0

Vnx . , . • SO.tt)

Crrntin« 1.Z&

Cnatlnlii* . . . . • l.&O

Drale of soda

1.80,,

Coloring m«ltnr and 1
Mutu« 1

Biplio?pliat<> of sohIa
riuiapliste of Duxia

" po1,-i««*

" UiDD

nilnriitrAof dioitlucn iiiid poUUKinm 7.80

EulphntHii (iT soiIa rtml i>u[i.ihx .,..,.. 6.90

.90

13.45

100U.OO

We need not repeat that the proportionate quantity of thesBJ
diflerent tngrcdicnlJfi, as given above, is not absolute, but only
approximative; and that they vary, from time to time, within certain
physiological limits^ like the ingredients of all other animal fluids.

The urea, creatine, creatinine and urates have all been suffi-

BBAGTIONS OF THE UBINB. • 886

ciently described above. The macas and coloring matter, unlike
tbe other ingredients of the urine, belong to the class of organic
substances proper. Thej are both present, as may be seen by tbe
analysis quoted above, in very small quantity. The coloring
matter, or ttrosaeine, is in solution in a natural condition of the
urine, but is apt to be entangled by any accidental deposits which
may be thrown down, and more particularly by those consisting of
tbe urates. These deposits, from being ofieu strongly colored red
or pink by the urosacine thus thrown down with them, are known
nnderthe name of "brick-dust" sediments.

The mucus of the urine comes from the lining membrane of the
urinary bladder. When first discharged it is not visible, owing to
its being uniformly disseminated through tbe urine by mechanical
agitation; but if the fluid be allowed to remain at rest for some
"bouTS in a cylindrical glass vessel, the mucus collects at the bottom,
xnd may then be seen as a light cottony cloud, interspersed often
with minute semi-opaque points. It plays, as we shall hereafter
see, a very important part in the subsequent fermentation and
decomposition of the urine.

Sij^iosphate of soda exists in the urine by direct solution, since it is
Teadily soluble in water. It is this salt which gives to tbe urine its
Acid reaction, as there is no free acid present in the recent condition.
3t is probably derived from the neutral phosphate of soda in the
Ttlood, which is decomposed by the uric acid at tbe time of its form-
Ation; producing, on tbe one hand, a urate of soda, and converting
a part of the neutral phosphate of soda into the acid biphospbate.

The phosphates of lime and magnesia^ or the "earthy phcephates,"
ms they are called, exist in the urine by indirect solution. Though
insoluble, or very nearly so, in pure water, they are held in solu-
tion in the urine by the acid phosphate of soda, above described.
*rhey are derived from the blood, in which they exist in considera-
"ble quantity. When the urine is alkaline, these phosphates are
deposited as a light-colored precipitate, and thus communicate n
turbid appearance to tbe fluid. When tbe urine is neutral, they
may still be held in solntion, to some extent, by the chloride of
sodium, which has the property of dissolving a small quantity of
phosphate of lime. .

Tbe remaining ingredients, phosphates of soda and potassa, sul-
phates and chlorides, are all derived from tbe blood, and are held
directly in solution by tbe water of the urine.
The urine, constituted by the above ingredients, forms, as we

336

BXCBETIOK.

have already described, a clear amber-colored fluid, with a reacttoa
for tht; most part distiactly acid, sometimes neutral, aod occasion-
ally slightly alkaline. In its healthy canditioD it is affected by
chemical and physical rcagcntit in the followmg manner. ■

Boiling the urine does not produce any visible change, provided
its reactiou be acid. If It be neutral oralkiUitie, and ii^ at the same
time, it contain a larj^or quantity than usual of the earthy phos-
phates, it will become turbid on boiling; sinoe these salts are less
soluble at a high than at a low temperature.

The addition of nitric or other mineral acid produces at first only
a slight darkening of the color, owing to the action of the acid upon
tbo organic coloring matter of the urine. If the mixture, however,
be allowed to stand for some time, the urates of soda, potasaa, &c.,
will be decomposed, and pure uric acid, which ia very insoluble,
will be deposited in a crystalline form upon the sides and bottom
of the glass vessel. The crystals of uric acid have most frequently
tbo form of transparent rbomboidal plates, or oval lamina: with ■
pointed extremities. They are usually tinged of a ycHowish hoe
by the coloring matter of the urintj which is united with them
at the time of Ibeir deposit. They are frequently arranged inS
radiated clusters, or small spheroidal masses, so as lu prcseai the

appearance of minute calcu-
^''S-^**' louB concretions, (Fig. 115.)

The crystals vary very much
in siso and regularity, ac-
cording to the time occupied
in their formation.

If a free alkali, such as
potnasa or soda, be added to
the urine, so as to neutralize
its acid reaction, it becomei
immediately turbid from a
deposit of the earthy phoa-
pbaLes, which are insoluble
in alkaline Huids.

The addition of nitrate of
baryta, chloride of barium,
or Bubacetate of lead to heolthy urine, produces a dense procipi-,
late, owing to the presence of the alkaline sulphates.

Nitrate of silver produces a precipitate with the chlorides of
sodium and potassium.

. 0

V»te AciD^ de)i<>*lit<l rrcDi urlDO.

BBACTIONS OF THE URINE. 337

Sabacetate of lead and nitrate of silver precipitate also tbe or-
gaoic sabstances, maous and coloring matter, present in the arine.
All the abore reactions, it will be seen, are owing to the presence
of the natural ingredients of the nrine, and do not, therefore, indi-
cate any abnormal condition of the excretion.

Beside the properties mentioned above, the urine has several
others which are of some importance, and which have not been
aaually noticed in previous descriptions. It contains, among other
ingredients, certain organic substances which have the power of
interfering with the mutual reaction of starch and iodine, and even
of decomposing the iodide of starch, af^r it has once been formed.
^?ht8 peculiar action of the urine was first noticed and described
Itj us in 1866.^ If 3j of iodine water be mixed with a solution
of starch, it strikes an opaque blue color ; but if 5j of fresh urine
"be afterward added to the mixture, the color is entirely destroyed
a.t the end of four or live seconds. If fresh urine be mixed with
f%>ar or five times its volume of iodine water, and starch be
Bubseqaently added, no union takes place between the starch and
iodine, and no blue color is produced. In these instances, the iodine
unites with the animal matters of the urine in preference to com-
Ixiaing with the starch, and is consequently prevented from striking
its ordinary blue color with the latter. This interference occurs
larhether the urine be acid or alkaline in reaction. In all cases in
which iodine exists in the urine, as for example where it has been
mdministered as a medicine, it is under the form of an organic com-
bination; and in order to detect its presence by means of starch, a
few drops of nitric acid must be added at the same time, so as to
deetrby the organic matters, afler which the blue color immediately
tppears, if iodine be present. This reaction with starch and iodine
belongs also, to some extent, to most of the other animal fluids, as
the saliva, gastric and pancreatic juices, serum of the bluod, &c.;
bat it is most strongly marked in the urine.

Another remarkable property of the urine, also dependent on its
organic ingredients, is that of interfering with Trommer's test for
grape sugar. If clarified honey be mixed with fresh urine, and sul-
phate of copper with an excess of potassa be afterward added, the
mixture takes a dingy, grayish blue color. On boiling, the color
tains yellowish or yellowish brown, but the suboxide of copper is
not deposited. In order to remove the organic matter and detect

AiD«rii»ii Joarn&l U«d. Soi., April, 18&6.

888 EXCBETIOS".

ibe sugar, ibo urine must be drst treated with an excess of animal
charcoal and filtered. By tbta means the organic substances are
retained upon the frlter, while thesugnr passes through in solution,
and may then be detected as usual by Trommer's test,

ACCIDEKTAL Inorediskts OP THB Ubins.— SlDCe tbc ufine, in
its natural state, consists of materials which are already prepared in
the blood, and which merely puas out through tlio kidneys by a
kind of filtration, it is not stirprisiog that most medicinal and
poisonous substances, introduced into the circulation, should be
expelled from tho body by the same ehafinel. Those aubstanoes
which tend to unite strongly with the animal matters, and to form
with them insoluble compounds, such as the preparatiotis of iron,
lead, silver, arsenic, mercury, &c., are least liable to appear in the
urine. They may occasionally be detected in this fluid when they
have been given in large doses, but when administered in moderate
quantity are not usually lo be found there. Most other substances,
however, accidentally present in the circulntion, pass off readily by
tlie kidneys, either in their original form, or after undergoing cer-
tain chemical modifications.

The salts of the organic acids, such aa hctates^ acelales, Tnalates^
&c., of soda and pota,'*ia, when introduced into the circulation, are
replaced by the carbonates of the same bases, and appear under
that form in the urine. The urine accordingly becomes alkaline
from the presence of the carbunntes, whenever the above sails have
been taken in large quantity, or after the ingestion of fruits and
vegetables which contain them. We have already spoken (Chap. IL)
of the experiments of Lehmann, in which ho found the urine exhi-
biting an alkaline ruaction, a very few minutes aft«r the administra-
tion of lactates and acetates. In one instance, by experimenting
upon a person with congenital extroversion of the biailder, in whom
the orifices of the ureters were exposed,' he found that the urine
became alkaline in the course of seven minutes after the ingestion
of half an onnce of acetate of potassa. ■

The pure nlkalifs and their carbonates, according to the same ob-
server, produce a similar effect. Bicarbonatoof [>ota;{sa, for example,
administered in doses of two or three drachms, causes the urine
to become neutral in from thirty to fortyfivc minutes, and alkaline
in the course of an hour. It is in this way that certain " antical-

■ Ph/siologloAl Cbemiati7, <rol. U. p. ISa.

ACCIDEyTAL INOBEDIENTS 0? THE UBINS.

caloas" or "anti-lithic" nostruma operate, when given with a view
of dissolving conoretions in the bladder. These remedies, which
are asaally strongly alkaline, pass into the urine, and by giving it
an alkaline reaction, produce a precipitation of the earthy phos-
phates. Such a precipitate, however, so far from indicating the
SQCcessful disint^ration and discharge of the calculus, can only
tend to increase its size by additional deposits.

Ferroeyanide of potassium^ when introduced into the circulation,
appears readily in the urine. Bernard* observed that a solation of
this salt, after being injected into the duct of the submaxillary
glaod, could be detected in the urine at the end of twenty minutes.
Iodine, in all its combinations, passes out by the same channel.
We have found that after the administration of half a drachm of
the syrup of iodine of iron, iodine appears in the urine at the end
of thirty minutes, and continues to be present for nearly twenty-
four hours. In the cose of two patients who had been taking iodide
of potasfliam freely, one of them for two months, the other for six
weeks, the urine still contaioed iodine at the end of three days
After the anspension of the medicine. In three days and a half,
liowever, it was no longer to be detected. Iodine appears alf>o,
after being introduced into the circulation, both in the saliva and
the perspiration.

Quinine, when taken as a remedy, has also been detected in the
^nrine. Sther passes out of the circulation in the same way. We
liave observed the odor of this substance very perceptibly in the
urine, after it bad been inhaled for the purpose of producing anses-
tbesia. The bile-pigment passes into the urine in great abundance
Id some cases of jaundice, so that the urine may have a deep yellow
or yellowish brown tinge, and may even stain linen clothes, with
"which it comes in contact, of a similar color. The saline biliary
mbstanees, viz., glykocholate and tauro-cholate of soda, have occa-
nonally, according to Lehmann, been also found in the urine. In
these instances the biliary matters are reabsorbed from the hepatic
ducts, and afterward conveyed by the blood to the kidneys.

iSu^ar.— When sugar exists in unnatural quantity in the blood,
it passes out with the urine. We have repeatedly found that if
sugar be artificially introduced into the circulation in rabbits, or
injected into the subcutaneous areolar tissue so as to be absorbed by
the blood, it is soon discharged by the kidneys. It has been shown

' LeqoQB d« Fhyaiologie Experimental e, 1856, p. 111.

840

KXCRETTOS".

by Bernard' that the rapidity with which this subsfcmce appears in
the urine under these circumainncea varies with the quantity in-
jected and the kind of sugar used for the experiment. If a solution
of 16 grains of glucose be injected into the areolar tissue of a rabbit
weighing a little over two pounds, it is entirely destroyed in the
circulation, and does not paaa out with the urine. A dose of 23
grains, however, injected in the same way, appears in the urine at
the end of two hours, 30 grains in an hour aud a hulf, 8^ grains to
an hour, and 188 grains in fil\een minutes. Again, the kind of
sugar used makes a diRerence in this respect. For while 15 grains
of glucose may be injected without passing out by the kidneys,
7^ grains of cane 8iig»r, introduced in the same way, fail U> be com-
plelety destroyed in the circulatioo, and may be detected in the
urine. In certain forms of disease (diabetes), where sugar accu-
mulates in the blood, it is eliminaled by the same channel; and a
aacchariue condition of the urine, accompanied by an iucreaw in
its quantity and specific gravity, coustitutes the most characteristic
feature of the disease.

Finally, a^ufncn sometimes shows itself in the urine in conae-
quence of various morbid conditions. Most acute inBammntioos
of the icterual organs, as pneumonia, pleurisy, &c., are liable to be
accompanied, at their outset, by a congestion of the kidneys, which
produces a temporary exudation of the albutninuus elements of the
blood. Albumen has been found in the urine, according to Simon,
Becquerel, and others, in pericarditis, pneumonia, pleurisy, bron-
ubitis, hepatitis, iuilaniinaliou of the brain, perlloaitis, metritis, &c.
Wo have observed it, as a temporary condition, in pneumonia and
after amputation of tlie thigh. Alljumitioua urine also occurs fre-
quently in pregnant women, and in those affected with abdominal
tumors, where the pressure upon the renal veins is sufficient to
produce passive congestion of the kidneys. Whuu the renal con-
gestion is spontaneous in its origin, and goes od to produce actual
degenerution of the tissue of the kidneys, as in Bright's disease, the
same symptom occurs, and remains as a permanent condition. In
all such instances, however, as the above, where foreign ingredients
exist in the uritie, these substauees do nut originate iu the kidneys
themselves, but are derived from the blood, in the same manner as
the tmtural ingredients of the excretion.

Ii«(ODa do Ph^s. Bxp., ISbi, p. 214 e( Mf.

ACID FEBUKNTATIOIT OF THE CRTlfE. 841

Changes in the Ubine during Decomposition.— When the
urine is allowed to remain exposed, afler its discharge, at ordinary
temperatares, it becomes decomposed, afler a time, like any other
animal fiuid; and this decomposition is characterized by certain
changes which take place in a regular order of succession, as fol-
lows:—

After a few hours of repose, the mucus of the urine, as we have
mentioned above, collects near the bottom of the vessel as a light,
nearly transparent, cloudy layer. This macus, being an organio
Bshetance, is liable to putrefaction; and if the temperature to which
it is exposed be between 60** and 100° F., it soon becomes altered, and
Gommnnicates these alterations more or less rapidly to the superna-
tant fluid. The first of these changes is called the acid fermentation
of the urine. It consists in the production of a free acid, usually
lactic acid, from some of the undetermined animal matters con-
tained in the excretion. This fermentation takes place very early;
within the first twelve, twenty-four, or forty -eight hours, according
to the elevation of the surrounding temperature. Perfectly fresh
urine, as we have already stated, contains no free acid, its acid
reaction with test paper being dependent entirely on the presence
oS biphosphate of soda. Lactic acid nevertheless has been so fre-
quently found in nearly fresh urine as to lead some eminent
chemists (Berzelius, Lehmann) to regard it as a natural constituent
of the excretion. It has been subsequently found, however, that
urine, though entirely free from lactic acid when first passed, may
frequently present traces of this substance afler some hours' expo-
sure to the air. The lactic acid is undoubtedly formed, in these
cases, by the decomposition of some animal substance contained in
the urine. Its production in this way, though not constant, seems
to be sufficiently frequent to be regarded as a normal process.

In consequence of the presence of this acid, the urates are par-
tially decomposed; and a crystalline deposit of free uric acid slowly
takes place, in the same manner as if a little nitric or muriatic acid
had been artificially mixed with the urine. It is for this reason
that urine which is abundant in the urates frequently shows a de-
posit of crystallized uric acid some hours after it has been passed,
though it may have been perfectly free from deposit at the time
of its emission.

During the period of the "acid fermentation," there is reason to
believe that oxalic acid is also sometimes produced, in a similar
manner with the lactic. It is very certain that the deposit of oxa-

S42

BSCBITIOX,

late of lime, far from being a dnngeroua or cron morbid symptom,
aa it waa at one time regarded, is frequently preseni in perfectly
oormal urine atler a. day or two of expusuru to the atmosphere.
Wo have oflen observed it, under these cireumstances, n'hen no ■
morbid Hyniptoin cuulil bo detected in couoectiou either with the
kidneys or with any other bodily organ. Now, whenever oxalic
aoid is formed in the urine, it tnuat necessarily be deposited under
the form of uxahite of lime: aioco this salt is entirely insoluble
both in water and in the urine, even when heated to the boiling
point. It is difficult to understand, therefore, when oxalate of lime
La found as a deposit in the urine, how it can previously hare been
held iu solatton. Ita oxalic acid is in all probability gradually
formed, as we have said, in the urine itself; unitini;, as fast as it is
produced, with the lime previously in aolution, and thus appearing
asa crystallinedepoaitof oxalflteof lime. It is much more probable
that tliits is the true explunatioo, since, in the cases to which we
allude, the crystals of oxalate of lime grow, as it were, in the cloud
of tnucus which cullecis at the bottom of the vessel, while the
supernatant iluid remains clear. The^ crystals are of raioute size,

transparent, and colorless,
^'g- *i*- and have the form of regular

octohedra, or double quad*
rangular pyramids, united
buseiobose. (Fig.116.) They
mako their ap|>earance usu-
ally about the commence*
meiit of the second day, the
urine at the satne time ooo>
tinuing clear and retaining
ita acid reaction. Thisdepo-
sit is of freq^ueot occurrence
when DO substance contaiu-
iDg oxalic acid or oxalates
has been taken with tbo food.
At the end of some days
thu cbauges above described
come to nn end, and are succeeded by a diflerent process known as m
the al^'afiiie/ermaitaU'on. This consists essentially in the docompo*
sitiou or metamorphosis of the urea into carbonate of ammonia.
As the ulLurution of the mucus advances, it loses the power of pro-
ducing lactic and oxalic auidis aud becomes a ferment capable of

J
I

OiiLJiTK vr LiaK; dfpoilirirrotDEiMilllijruHa*,
dnrtcf lk« »ckd f«nit«DtMl«a.

ALKALINE FKBHENTATION 07 THE URINE. 343

acting by cataljsis apon the urea, add of exciting its decomposition
as above. We hare already mentioned that urea may be converted
into carbonate of ammonia by prolonged boiling or by contact
with decomposing animal substances. In this conversion, the urea
unites with the elements of two equivalents of water ; and conse-
quently it is not susceptible of the transformation when in a dry
state, but only when in solution or supplied with a sufficient quan-
tity of moisture. The presence of mucns, in a state of incipient
decomposition, is also necessary, to act the part of a catalytic
body. Consequently if the urine, when first discharged, be passed
through a enocession of close filters, so as to separate its mucus, it
may be afterward kept, for an indefinite time, without alteration.
Sat under ordinary circumstances, the mucus, as soon as its putre-
&ition has commenced, excites the decomposition of the urea, and
carbonate of ammonia begins to be developed.

The first portions of the ammoniacal salt thus produced begin to
neutralize the biphosphate of soda, so that the acid reaction of the
urine diminishes in intensity. This reaction gradually becomes
weaker, as the fermentation proceeds, until it at last disappears
Altogether, and the urine becomes neutral. The production of
carbonate of ammonia still continuing, the reaction of the fluid
then becomes alkaline, and its alkalescence grows more strongly
pronounced with the constant accumulation of the ammoniacal salt.

The rapidity with which this alteration proceeds depends on the
character of the urine, the quantity and quality of the mucus which
it contains, and the elevation of the surrounding temperature. The
urine passed early in the forenoon, which is often neutral at the
time of its discharge, will of course become alkaline more readily
than that which has at first a strongly acid reaction. In the summer,
urine will become alkaline, if freely exposed, on the third, fourth,
or fifth day; while in the winter, a specimen kept in a cool place
may stilt be neutral at the end of flfleen days. In cases of paralysis
of the bladder, on the other hand, accompanied with cystitis, where
the mucus is increased in quantity and altered in quality, and the
urine is retained in the bladder for ten or twelve hours at the tem-
perature of the body, the change may go on much more rapidly, so
that the urine may be distinctly alkaline and ammoniacal at the
time of its discharge. In these cases, however, it is really acid
when first secreted by the kidneys, and becomes alkaline while
retained in the interior of the bladder.

The first effect uf the alkaline condition of the urine, thus pro-

344

Bxcrkt:on.

ducecl, 19 the precipitation of the earthy phosphates. These salts,
being iciiiotuble in neutral and alkaline Huids, begin to precipitate us
soon OS the natural acid reaction of the urine has fairly disappeared,
and thus produce in the fluid a whitish turbidity. This precipitate
slowly settles upon the sides and bottom of the vessel, or is partlv
entaiigltKl with certain animal matters which rise to the surface and
form a thin, opaline scum upon the urine. There are no crystals
to be Heen at this time, but the deposit is entirely amorphous and
granular in character.

The next change consists in the production of two new double
salts by the actiou of carbouate of aiomonia on the phosphates of
soda and magnesia. Cue of these is the "triple phosphate," phos-
phate of magnesia and ammonia (2MgO,NH,0,PO,+2HO), The
other ia the phosphate of soda and ammonia (NaO,NH^O,HO,PO,+
8H0). The phosphate of magnesia and ammonia is formed from
the phosphate of magnesia in the urine (3MgO,PO^+7HO) by
ihe repbcement of one equivalent of magnesia by one of am-
monia. The crystals of this salt ore verv elegant and charac-
teristic. They show themselves throughout all parts of the mix-
tare; growing gradually in the mucus at the bottom, adhering to

the sides of the glass, and
*^'^' "'^' scattered abundantly over

the film which collects upon
the surface. By their refract-
ive power, they give to this
l!lm a peculiar gliseeoiDg
and iridesoeot appearance,
■^- I which is nearly always visi-

t^J^ ^^^ I ble at the end of six or seven

days. The crystals are per*
fectly colorless and transpa-
rent, and have the form t>f
triangular prisms, generally
with bevelled extremities.
(Fig. 117.) Frequently, also,
their edges and angles are
replaced by secondary facets.
They are insoluble in alkalies, but are easily dissolved by acids,
even in a very dilute form. At first they are of minute size, but
gradually increase, so that after seven or eight days they may
become visible to the naked eye.

4e|i>'-lMd rruni li«alll>r UTlnv. JuKov klk4tlDt finneiL-
lailuu.

RBNOVATION BY NUTKITIVK PB0CE8S. 846

The phosphate of soda and ammonia is formed, in a similar
manner to the above, hy the union of ammonia with the phosphate
of soda previously existing in the urine. Its crystals resemble
very much those just described, except that their prisms are of a
quadrangular form, or some figure derived from it. They are
iDtermiDgled with the preceding in the putrefying urine, and are
affected in the same way by chemical reagents.

As the putrefaction of the urine continues, the carbonate of am-

3nonia which is produced, afler saturating all the other ingredients

Tfith which it is capable of entering into combination, begins to

"be given off in a free form. The urine then acquires a strong

■amrooniacal odor; and a piece of moistened test paper, held a little

aibove its surface, will have its color immediately turned by the

^kaline gas escaping from the fluid. This is the source of the

^mmooiacal vapor which is so freely given off from stables and from

«laDg heaps, or wherever urine is allowed to remain and decompose.

^This process continues until all the urea has been destroyed, and

"vntil the products of its decomposition have either united with

«)tber substances, or have finally escaped in a gaseous form.

Benotation op the Body by the Nutritive Pbocess. — "We
v»n now estimate, from the foregoing details, the quantity of the
different materials which are daily assimilated and decomposed by
'fthe living body. For we have already seen how much food is
'ftaken into the alimentary canal and absorbed by the blood after
digestion, and how much oxygen is appropriated from the atmo-
^}bere in the process of respiration. We have also learned the
smount of carbonic acid evolved with the breath, and that of the
-various excretory substances discharged from the body. The fol-
lowing table shows the absolute quantity of these different ingre-
dients of the ingesta and egesta, compiled from the results of direct
experiment which have already been given in the foregoing pages.

ABSORBSD SITBtKO 24 HOUBS. DtSOHABOSD DUKINa 24 HOUBS.

Oxygen

1.019 lbs.

Carbonic acid

1.535 lbs

Water

4.735 "

AqneoiiB vapor

1.155 «

AlbamiDOiu nutter

. .396 "

Pnrapiratioii .

1.930 "

Starah

.660 "

Water of the urine

2.020 "

Fat .

.220 "

Urea and salts

.110 "

SalU .

.040 "

Feces . .

.320 "

7.070 7.070

Bather more than seven pounds, therefore, are absorbed and dis-

346

EICTtBTlOIT.

charged daily by tho licnlthy adult huTnnn sabjcct; and, for & man
having tlio average weight of 140 pounda, a quantity of material,
equal to the weight of the entire body, thus passes through the
system in the course of twenty days, ■

It ia evident, also, that this is not a simple phenomenon of the
passage, or Bltration, of foreign substAoccs throngh the animal _
frame. Tbe materials which are absorbed actually combine with f
the tissues, and form a part of their substance; and it is only afler
undergoing subsequent decomposition, that they finaUy make their
appearance in the excretions. None of the solid ingredients of the
food are discharged under their own form in the urine, viz., as I
starch, Ikt, or albumen; but they are replaced by urea and other
crystaHlzable substances, of a different nature. Even the carbonie
acid exhaled by the breath, as experience has taught us, is not pro-
duced by a direct oxidation of carbon; but originates by a steady
process of decomposition, throughout the tissues of the body, some'
what similar to that by which it is generated in the decomposition
of sugar by fermentation. Tbese phenomena, therefore, indicate Stn
actual change in the substance of which the brtdy is composed, and
show that its entire ingredients are incessantly renewed under tha
influence of the vital operations.

SECTION II.
NERYOUS SYSTEM.

CHAPTER I.

GENERAL STRUCTURE AND FUNCTIONS OF THE
NERVOUS SYSTEM.

Ik entering upon the study of the nervous system, we commence
the examination of an entirely different order of phenomena from
those which have thus far engaged our attention. Hitherto we
have studied the physical and chemical actions taking place in the
body and constituting together the process of nutrition. We have
seen how the Inngs absorb and exhale different gases; how the
stomach dissolves the food introduced into it, and how the tissues
produce and destroy different substances by virtue of the varied
transformations which take place in their interior. In all these
instances, we have found each organ and each tissue possessing
certain properties and performing certain functions, of a physical
or chemical nature, which belong exclusively to it, and are cbarac-
teriatic of its action.

The foDctions of the nervous system, however, are neither phy-
rical nor chemical in their nature. They do not correspond, in
their mode of operation, with any known phenomena belonging to
these two orders. The nervous system, on the contrary, acts only
opon other organs, in some unexplained manner, so as to excite or
modify the functions peculiar to them. It is not therefore an appa-
ratus which acts for itself, but is intended entirely for the purpose
of influencing, in an indirect manner, the action of other organs.
Its object is to connect and associate the functions of different parts
of the body, and to cause them to act in harmony with each other.

84S

GENERAL STBUCTCBB AJTD FDITCTIOITS

This object may be more fully exemplified as folIowB:—
Each organ and tissue in the body has certain properties peculiar^
to it, which maybe called into activity by the operation of a stimu-
lus or exciting cause. This CAfiaciLy, which all the organs possess,
of reacting under the influence of a stimulus, is called their excita-
bility, or irritahility. We have often had occasion to notice this pro-
perty of irritability, in experiments related in the foregoing pages.
We have seen, for example, that if the heart of a frog, after being
removed from the body, be touched with the point of a needle, it
immediately contracts, and repeati the movement of an ordinary
pulsation. If the leg of a frog bo separated from the thigh, its
integument removed, and ihe polea of a galvanic battery brought
in contact with the exposed surface of the muscle^, a violent con-
traction takes place every time the electric circuit is completed,!
In this itistanee, the stimulus to the muscles is supplied by the
electric discharge, as, in the case of the ht^nrt above mentioned, it is
supplied by the contact of the steel needle; and in both, a muscu-
lar contraction is the immediate consequence. If we introduce a J
metnllic catheter into the empty stomach of a dog through a gastrio ■
fistula, and gently irritate with it the mucous membrane, a secretion
of gastric juice at once begins to take place; and if food be tatro-
duced the fluid is poured out in still greater abutidance. We know
also that if the integument be exposed to contact with a heated
body, or to friction with an irritating liquid, an excitement of tha ■
ciruulntion is at once produced, which again passes away af^r the
removal of the irritating cause.

lu all these instances we Gnd that ihe organ which is called into-
nctivity is excited by the direct application of some stimulus to its]
own tissues. But this is not usually the manner in which the dif-
ferent functions are excited during life. The stimulus which calls
into action the organs of the living body is usually not direct, but
indirect in its operation. Generally speaking, the organs which are
situated in distant parts of the body are connectetl with each other
by such A sympathy, that the activity of one is influenced by the
condition of the others. The muscles, for example, are almost never
called into action by an external stimulus operating directly upon
tbeir own ilbrcs, but by one which is applied to some other organ, ■
either adjacent or remote. Thus the peristaltic action of the mus-
cular coat of tlie intestine commences when the food is brought in
ooTitact with its mucous membrane. The lachrymal gland is excited,
to increased autivily by anything which causes irritation of tha-

OF THE NERTOCS SYSTEM. 849

oonjanctlTa. In all such instances, the physiological connection
between two different organs is established throagh the medium of
the nervous system.

The function of the nervous system may therefore be defined, in
the simplest terms, as follows: It is intended to associate the different
parts <if the body in such a manner, that an action may be excited in one
organ by means of a stimulus applied to another.

The instances of this mode of action are exceedingly numerous.
Thus, the light which falls upon the retina produces a contraction
of the pupil. The presence of food in the stomach causes the gall-
bladder to discharge its contents into the duodenum. The expul-
sive eflforts of coughing are excited by a foreign body entangled in
the glottis.

It is easy to understand the great importance of this function,
particularly in the higher animals and in man, whose organization
is an exceedingly complicated one. For the different organs of
tbe body, in order to preserve the integrity of the whole frame,
most not only act and perform their functions, but they must act in
harmony with each other, and at the right time, and in the right
direction. The functions of circulation, of respiration, and of
digestion, are so mutually dependent, that if their actions do not
take place harmoniously, and in proper order, a serious disturb-
ance must inevitably follow. When the muscular system is ex-
cited by unusual exertion, the circulation is also quickened. The
blood arrives more rapidly at the heart, and is sent in greater
quantity to the lungs. If the movements of respiration were not
accelerated at the same time, through the connections of the nerv-
oas system, there would immediately follow deficiency of aeration,
Taacular congestion, and derangement of the circulation. If the
iris were dot stimulated to contract by the influence of the light
falling on the retina, the delicate expansion of the optic nerve
would be dazzled by any unusual brilliancy, and vision would bo
obscured or confused. In all the higher animals, therefore, where
the different functions of the body are performed by distinct organs,
situated in different parts of the frame, it is necessary that their
action sliould be thus regulated and harmonized by the operation
of the nervous system.

The manner in which this is accomplished is as follows: —
The nervous system, however simple or however complicated it
may be, consists always of two different kinds of tissue, which are

850

OHKERAL 8TBUCTUBB AND TCFCTIOyS

distinguished From each other by their color, their structure, an
their raode of aclioQ. One of theae is known as the tckite stihsiance^
or iUe fibrous {issue. It constitutes itie whole of the substance of the
nervous trunks and branches, and is found in large quantity oa the .
exterior of the spinnl cord, and in the central partA of the brain
and cerebellum. In the latter situations, it is of a soil consistency, .
like curdled cream, and of a uniform, opaque white color. In
the trunks and branches of the nerves it has the same opaquB'
white color, but is at the saiiio time of a firmer consistency, oiring
to its being mingled with condensed areolar tissue. Examined hj
the microscope, the white substance is seen to be composed every-'
where of miuute fibres or filaments, the "ulliniate nervous fila-
ments," running in a direction very nearly parallel with encb other.
These filamenta are cylindrical in shape, and vary considerably in
size. Those which ore met with in the spinal cord and tho brain
ore the smallest, and have an average diameter of inhan of aa
inch. In the trunks and branches of the nerves they average mSv
of an inch.

The structure of the ultimate nervou.<) filament is as foUowa:
The exterior of each filament consists of a colorless, transparent
tubular membraoe, which la seen with some diHicully in the oaturnl
condition of the fibre, owing to the extreme delicacy of Its toxturo,
and to its cavity being completely filled with a substance very
aimilar to it in refractive power. In the interior of this tubular
membrane there is contained a thick, semi-fluid nervous matter,
which is white and gliuteuing by n-Hected light, and is called the
"white substanco of Schwann." Finally, running longitudinally
through the central piirt of each filament, is a narrow ribbon-
shaped cord, of rather firm consistency, and of a iiemi-transpArent
grayish color. This central portion is called the "axis cylinder,"
or the '^flattened baud." It is enveloped everywhere by the semi-
fluid white subAtanco, and the whole ioveatod by tlie external tubu-
lar membrane. ■

When nervous matter is prepared for the microscope and exa-
mined by transmitted light, two remarkable appearances are ob-
served in its filaments, produced by the contact of foreign aub-
Rlances. In the first place the unequal pressure, to which the fila-
menta are accidentally subjected in the process of dissection aod
preparation, produces an irregularly bulging or varicose appearance
in them at various points, owing to the readiness with which the
semi-fluid white substance in tlicir interior is displaced in dt^rent

OF THE NERVOUS 8TSTBU.

861

Nebtoci Filamekti from whlta inhaUnce of
brain.— <!, a, a. Boft iDlwunee of th« fliamentii praued
ont, And doatlut In irr^nUrlj ronnded drops.

directions. (Fig. 118.) Sometimes spota may be Been here and
there, where the nervous matter has been entirely pressed apart in
the centre of a filament, so

that there appears to be an ^'g- lis.

entire break in its continuity,
while the investing mem-
brane may be still seen, pass-
ing across from one portion
to the other. When a nerr-
408 filament is torn across
imder the microscope and
aobjected to pressure, a cer-
'Sain quantity of the semi-
^aid white substance id
3}ressed out from its torn
viztremity, and may be en-
"•trely separated from it, so
90 to present itself under the
:ft)rm of irregularly rounded
^rops of various sizes (a, a,
«i;), scattered over the field of the microscope. The varicose appear-
'^uce above alluded to is more frequently seen in the smaller nerv-
^>iis filaments from the brain and spinal cord, owing to their soft
«x}n8Utency and the readiness with which they yield to pressure.

The second e£fect produced by the artificial preparation of the
siervous matter is a partial coagulation of the white substance of
Schwann. In its natural condition this substance has the same
«x>n8istency throughout, and appears perfectly transparent and
homogeneous by transmitted light. As soon, however, as the nerv-
ous filament is removed from its natural situation, and brought in
<»Dtact with air, water, or other unnatural fluids, the sofl substance
Immediately under the investing membrane begins to coagulate.
^t increases in consistency, and at the same time becomes more
liighly refractive; so that it presents on each side, immediately
underneath the investing membrane, a thin layer of a peculiar
glistening aspect (Fig. 119.) At first, this change takes place
only. in the outer portions of the white substance of Schwann.
The coagulating process, however, subsequently goes on, and
gradually advances from the edges of the filament toward its
centre, until its entire thickness after a time presents the same
appearance. The effect of this process can also be seen in those

352

GENERAL STRUCTUBI AND rCKCTtOyS

portions of the white substance which have hocn pressed out froai
the ioterior of iho filameots, aod which float about iu the fonnof

drops, (tig. 118, ii) These
Fig. 119. drops are alwajs covered

with a layer of coflgulaied
material which is thicker
and more opaque id propor-
tion to tho length ot lime
which has elapsed siooe the
commcncenient of the alter*
ation.

The nervous filaments
Kave essentially the same
structure ia the brain and
spioal cord as in the aervoiia
trunks and branches; only
they are of much sinallef
size in the former than in
the latter situation. In the
nervottstrunksanil branches,
however, outside the craniil
and spiual cavities, ibers
exists, superadded to the
oervous filaments and interwoven with them, a large amount of
condensed areolar or fibrous tissue, which protects them frooi
injury, and gives to this portion of the nervous system a. peculiar
density and resistance. This diflerencc in consistency between the
whitt! tjubntaace of the nerves and tliat of the brain and spinal cofd
is owing^ therefore, excluaively to the presence of ordinary fibrooa
tissue in the nerves, while it is wanUng in the brain and spioal
cord. The cousistency of the nervous filaments themselves is the
same in each situation.

The nervous filaments are arranged, in the nervous trunks aod
branches, in a direction nearly parallel with each other. A certaia
number of them are collected in the form of a bundle, which i*
invested with a layer of Gbroua tissue, in which run the small
bloodvcsseLa, destined for the nutrition of the nerve. These pri-
mary bundles are again united into secondary, the secondary inu
tertiary^ kc. A nerve, therefore, consists of a large bundle of ulti-
mate filaments, associated with each other in larger or smaller
packets, and bouud together by the investing fibrous layers. When

(h«lr cuiciiJullon — At u. ilia loru vKlraialtJ of ■
nsrvoa* OUrnvoi iriih tbf ■«)■ cf liadnr {bt protrntllng
rroni It Ai<'.ih« vlili«*nbii«ii»ii(Scliw*aiilii iiMrly

■oparairil liy icrldcuUl niiii|iri'Hluii, but lb* all*-
ofllail«r pKHti Mr«ui ib* nipluroj ponl^o. The vul-
llua vt 111* iiil'iilkc inurnl-nni U hIihi »fva Hi c un Iha
onNlil* i>r [1i* uarvun* BIkiuiiiiL

OF THE XERTOVS 8T8TEV.

853

a nerve is said to becomo branched or "tlivided" in nny part of its
course, tliis division merely implies that aomeof its filaments leare
ttie bundles with which they were
previously associated, and pursue ^s- 120.

a different direction. (Fig. 1'2I>.)
A nerve which originatesi, for ex-
ample, from the spinal cord in the
region of the neck, and runs down
j the upper extremity, dividing and
fflubdividing, to be finally diHtri-
buted to the integument and mus-
icles of the band, contains at its
point of origin all the filaments
into which it is afterward divided,
and which are merely separated
ai successive points from the
roain bundle. The ultimate fila-
taenia, accordiugly, are coutiau'
ous throughout, and do not thom-
' salves d ivide at any point between
(beir origin and their final distri-
bution.

When a nerve, furthermore, is

said to "iooeculate" with unotlior

, nerve, as when the infra-orbital

"EaotKulittes with the facial, or the

cervical nerves inosculate with

each other, this means simfily that some of the filaments composing
the first nervous bundle separate from it, and cross over to form a
part of the second, while some of those belonging to the second
-orosa over and join the first (Fig. 121); but the individual filaments
in each instance remain cuntinuous and preserve tbeir identity
tliroughout. This fact is of great physiological importance; since
the white or fibrous oerve-substaoce is everywhere simply an
organ of transmission, It serves to convey the nervous impulse in
■ various directions, from without inward, or from within outward;
and as each nervous filament acts independently of the others, it
will convey an impression or a slimnUis continuously from its
origin to its termination, and will always have the same character
aod function in every part of its course.

The other variety of nervous inaltur is knuwu as the gray gtd>-
2tt

tll>l>ili<(l or ■ XlIKVII, •llnvllig pi»lliiti ilf

ncrrcTi. Ininlf {n). and the lOpMVLlou at lu
aI'DiBDta \>y, c, il, a).

854

GGN'GRAL STRUCTURE ASD FUKCTIOSB

stance. It is sometimes called "cineritioiis mutter," and sometimes
"vesicular aeurine." It is fuund in the centra] parljs of the spiDftl

FIr 121.

|l14.isOlllj(JiD|L of TSeRITEA.

conl, at the base oF the brain in isolated masses, and is also spread
out as a continuous layer on tliu external portions of tbe cerebrum
and cerebellum. It also constitutes the substance of all the goo*
glia of the great sympathetic. Examined by the microscope, it

consists of vesicles or celU, of

Pig. 123.

ytMn Cii.ta, lal«rmis|lnd wHb llbm; fruni
•rtallHaarffaclluB «f fat.

various forms and sizes, im-
bedded in a grayish, granular,
intercelluUr substance, and
contnining, also, very fre-
queotly, granules of grayish
pigmentary matter. It is to
the presence of this granular
pigment that this kind of
nervous matter owes the ashy
or "cioeritious" color from
which it derives its name.
The cells composing it vary
in size, according to Kollikcr,
from ,nff8 to loiF of ••» inch.
Tlie largest of them have a

OF THE XKBVOL'B 8TSTBM.

8fi5

very distinct nucleus and nucleolus. (Fig. 122.) Many of them ore
provided with long processes or proje<>tions, uliicb are fiumeiitncs
divided into two or three smaller brimches. These cella ore inter-
mingled, in all the collections of gray matter, with nervous RlamenL*.
and are eniAngled with their extremities in such a manner that tt
is exoeedinglv diflicult to ascertain the exact nature of the anato-
mical relations existing between iheni. It in certain that in some
instance* the slender processes running out from the nervous veai-
ekt become at last continuous with the Blamcnta; but it is not
IcoowQ whether this be the case in all or even in a majority of
iDstauces. The extremities of the filaments, however, are at all
ercnts brought into very cloue relation with the vesicles or cells of
the gray matter.

Kvery collection of gray matter, whatever be its situation or
relative size iu the nervous system, is called a gttngiion or nert<ma
centre. Its function is to receive impressions conveyed to it by the
nervous filaments, and to send out by them impulses which are to
be transmitted to distant organs. The ganglia, therefore, originate
nervous power, so to speak; while the filaments and the nerves
only transmit it. Now we shall find that, in the Htructure of every
nervous system, the ganglia are connected, first with the difleront
or-gans, by bundles of filaments which arc called nerves; and
s^^oodly with each other, by other bundles which are termed com-
ntisdures. The entire system is accordingly made up of pauglia,
**«rir», and comntissures.

The simplest form of nervous system is probably that found in
IV five-rayed starfish. This animal belonga to the type known
*i radiata; that is, animals whose
'■fgans radiate from a central point, Fig- 1'-^-

so as to form a circular series of
nniilar parts, each organ being ro-
jieated at different points of the
circumference. The starfish (Fig.
123) consists of a central mass,
with five arms or limbs radiating
from iu In the centre is the mouth,
and immediately beneath it the sto-
mach or digestive cavity, which
Rcnds prolongations into every one
of the projecting limbs. There is
also contained in each limb a portion it,BT«M bktbv ^r s? Airt.w.

8&«

OENCRAl. BTRUCTURE AVD 7CNCTI0N3

uf the glandular and muscular systems, and the whole ia covered
by a sensitive inleguinent. Tim nervuus aysteni consists of five,
similar ganglia, situated in the central portion, at the base of thaij
arms. These ganglia are connected with each other bycommts<|
surea, so as to form a nervous collar or chain, surrounding
onfiae of the digestive cavity. Kach ganglion also sends off nerTefl,!|
iho lilaments of which are distributed to ibo organs contained -ti
the corresponding limb.

We have already stated that the proper function of the nervonfll
system is lo enable a stimulus, acting upon one organ, to produoa]
motion or excitemcut in another. This is ocoomplished, in lbs]
starfish, in the following manner: —

When any stimulus or irritation is applied to the integument of]
one of the arms, it is transmitted by the nerves of the integumeatj
to the ganglion situated near the mouth. Arrived here, it iaj
received by the gray matter of the ganglion, and immcilialelj con-!
verted into an impulse which is sent oat by other 61amenia to thai
muscles of the corresponding limb; and a muscular contraction and
movement consequently lake place. The muscles therefore contract
in consequence of an irritation which has been applied to the skin.
This is called the "reflex action" of the nervous system; because the,
stimulus is first sent inwiird by the nerves of the integument, and'
then returned or rellwtcd back from the ganglion u[k>d the masclea.
It must be recollected that this action docs not neceasarily indicate
nny sensation or volition, nor even any conaciousneas on the part of
the animal. The function of the gray matter is simply to receive ^
the impulse conveyed to it, and to reflect or send back another; andlfl
this may be accomplished altogether involuntarily, and without the
existence of any conscious perception.

Where the irritation applied to the integument is of an ordinary
character and not very intense, it is simply rc6ected, as above
described, from the corresponding ganglion back to the same limb.
But if it bo of a peculiar character, or of greater intensity than usual,
it may be also transmitted by the commissures to the neighboring
ganglia; and so two, three, four, or even all five of the limbs may
be set in motion by a stimulus applied to the Integument uf one of
them. Now, as all the limbs of the animal have the same stmctuTe
and contain the same organs, their action will also be the same;
itnd the eflects of this communication of the stimulus from one to
the other by means of commissures will be a repetition, or rather
a Biinultiineuus ]>ruduciion of similar movements in different parts

or THE

867

of the body. According to the character and intensity, therefore,
of the original stimulus, it will be followed by a response from
one, several, or all of llie diflerent parts of the animal frame.

It will be seen also that there arc two kinds of nervous Hlaments,
diCering esaentially in their functions. One set of these fibres run
from the sensitive sarfacea to the ganglion, pnd convey the nervous
impression inward. These are called sensitive fibres. The other
set ran from the ganglion to the niusclea, and carry the nervous
impression outward. These are called motor fibrea.

In the starfish, where the body is composed of a repetition of simi-
lar parts arranged round a common centre, and where all the liinba
tre precisely alike in structure, the several ganglia compot'ing the
nervous system are also similar to each other, and act in the same
way. Bui in animals which are constructed ujvon a diflercnt plnn,
and whose bodies are composed of distinct organs, situated in dif-
ferent regions, we 6nd that the nervous ganglia, presiding over
the function of these organs, preaeot a corresponding degree of
dissimilarity.

In AphjsitL, for example, which belongs to the type of mollasca,
or sofi-bodied animals, the digestive apparatus consists of a mouth,
an cesophaguB, a triple stomach, and a somewhat convoluted iniep-
tine. The liver is large,' and placed on one side of the body, while
the gills, in the form of vascular laminm, occupy the opposite side.
There are both testicles and ovaries in the
same animal, the male and female functions
00-existir.g, as in many other invertebrate
specie*. All the organs, furthermore, are
here arranged without any reference lo a
regular or symmetrical plan. I'he horty is
oorered with a muscular mantle, which ex-
pands at the ventral surface into a tolerably
well developeil " foot," or organ of locomo-
tion, by which the animal ia enabled to
change its position and move from one
locality to another

The nervous system of this animal is con-
structed Dpon a plan tx}rrespondii)g with
that of the entire bo<ly. (Fig. 124.) There 5««Tr>p« tt*rxn or
« a small ganglion (.) situated anteriorly, tZ-r^.,,:rTcZ
which sends nerves to ihe commencement b^i «»<i«ii'^o. -1.3. i'*j*i ..r
of the digestive apparatus, and is rcganled „i,„f r..ug;i«a.

Fig. 124.

358

GENERAL STRUCTURE AXD FUNCTIONS

Fig. 125.

as the oesophageal or digestive franglion. Immediately behind
a larger one (a) called the cephalic or cerebral ganglion, whict
sends nerve* to the organs of special sen^e, and which is reganiei
as the ^eut of volitiou and general Bcnsation fur the entire body,
Following this is a pair of ganglia ().-i), ibe pedal or looomutcFr/
ganglia, which supply the muscular mantle and its fofit-like expaa-
sioD, and which regulate the movement of these organs. Finallr,
another gaoglion {*\ aiiuated at tbe p'tstcrior pare of the bodj,
seuds nerves to the brunchiio or gills, and is termed the braochttl
or respiratory ganglion. All these nervous centres are conDecled
by commissures wiih the central or cerebral ganglion, and maj
therefore act either independently or in association with each other,
by means of these connecting fibres.

Tn the third type of animals, uguin, viz , the orticula/tL, (he gaae*
ral plnn of Btnicture of the body is diftercnt from the foregoing,
and the nervous system is accordingly modified to correspond with
ii. Tu these animals, the body ia compoaed of i
number of rings or sections, whicb are articulated
with each other in linear series. A very gocxi
example of this type may bo found in tbeooo-
mon ceutipcde, or scolopfndra. Here tbe bodyb
composed of twenty-two successive and Dearly
similar articulationa, each of which bos a pairo(
legs attached, and contains a portion of the gUo-
dular, respiratory, digestive and reproductive
apparatuses. The animal, therefore, conaistaof a
repetition of similar compound parts, arranged ia
a longitudinal chain or series. The only exoep
tions to this similarity are in the Srst and Usi
articulations. The first is large, and ooataios
the mouth; the lost is small, and contains tbc
anus. The first articulation^ whicb is called tbe
"head," ia also furnished with eyes, with anteooa^
and wiih a pair of jaws, or mandibles.

The nervous system of the centipede (Kig. Xlh),
corresponding in structure with tbe abore plaa,
consists of a linear aeries of nearly equal ixiA
similar ganglia arranged in paira, situated u{wfl
tbe median line, along the ventral surface of ibe
alimentary canal. Kach pair of ganglia is connected with the in-
tegument uiid niusulcd of its own artiuuktiuu by auubiuve awl

or t'liriPtPi-

OP TBK NEBTOUS STSTEV.

859

motor 6IaTneDts; and trith those which precede and follow by a
double cord o( longitudinal commissural iibrca. In the flrst articu-
lation, moreover, or the head, the gAnglia are larger thao elsewhere,
and send nerves to the anteonse and to the organs of special sense.
This pair is termed the cerebral ganglion, or iho "brain."

A reBex action may take place, in these animals, through either
one or all of the ganglia composing the ncrroas chain. An im-
prcitsion received by the integument of nny part of the body may
be tntiismilled inwnrd to its own gaiigliou and thence reflected
immediately outward, so as to produce a movement of the Wmhti
belonging to that articulation alone; or it may be propagated,
Ihroogh the longitudinal cammi»9urcs, forward or back, and pro-
duce simuliaueous movements in several neighboring arliculalions;
'Or, Gaully, it may be propagated quite up to the anterior pair of
ganglia, or "brain," where its reception wiil be accompanied with
oonaciousnesa, and a voluntary movement reflected back upon any
or all of the limbs at once. The organs of special sense, also, com-
municate directly wiLh the cerebral ganglia; and impressions con-
veyed through them may accordingly give rise to movements in
my distant part of the body. In these animals the ventral ganglia,
or those which simply stand as a medium of commniiicntion be-
tween the iotegumtut and the muscles, are nearly similar through-
out; while the first pair, or those which receive the nerves of special
sense, and which exercise a general controlling power over the rest
of the nervous system, arc distinguished from the remainder by a
well-marked preponderance in size.

In the centipede it will be noticed that nearly all the organs and
functions are distributed in an rajnal degree throughout the whole
length of the body. The organs of special sense alone, with those
of mastication and the functions of perception and volition, arc
confined to the head. The ganglia occupying this part are there-
fore the only qocs which are diatinguished by any exlemal pecu-
liarities; the remainder being nearly uniform both in size and
■ctivity. In some kinds of articulated animals, however, particular
functions are concentrated, to a greater or less extent, in particular
parts of the body; and the nervous ganglia which preside over
them are modified in a corresponding manner. In the insects,
tvT example, the body is divided into three distinct sections, viz:
the head, containing the organs of prehension, tnaslicatioii, t.ict
tod special sense; the chesl, upon which are concentrated the or-
gans uflocomotion, the legs ami wiugn; and the abdomen, conuiin-
ing the greater part of tho olimuuiary canal, together with the

360

GENERAL BTRL'CTURE AXU PITNCTIOKS

glamliilar and generative organs. As tlie insects liave a greater
ami)iint of intelligence and activity than the oentipcdca and other
worm-like articulata, and as the organs of special sense are more
perfect in them, the cerebral ganglia are als^j uDuaually developed,
and are evidently compu»ud uf several pairs, connected by commis-
sures aa as to form a compound mass. As the organs of locomo-
tion, furthermore, instead of being distributed, as in the centipede,
throughout the entire length of the animal, are concentrated u]>oii
the cht'st, the locomolory ganglia also prepttnderatc ta size in this
region of the body ; while the ganglia which preside over the secre-
tory and generative functions arc situated together, in the cavity of
the abdomen.

All the above parts, however, are coiiaected, in the sanie manner
08 previously described, wiih the anterior or cdrebral pair of guo-
glia. In all articulate animals, moreover, the general arrangement
of the body U symmetrical. The right side is, for the most part,
precisely like the led, as well in the Internal organs aa in the ex-
ternal covering and the looomotory appendages. The only marked
variation between different parts of the body is in an anteropos-
terior direction; owing to diCerent organs being concenlrated, in
some cases, in the bead, chest, and abdomen.

Finally, in the veriei*raie type of animiils, comprising man, the
quadrupeds, birds, reptiles, and fish, the external parts of the body,
Mgethcr with the tocomotory apparatus and the organs of special
sense, are symmetrica), as in the articulate; but the internal organs,
especially those concornod in the digestive and -secretory functions,
nre ansynimetrical and irregular, as in the moUusca. The organs
of respiration, however, are nearly symmetrical in the vertebrata,
for the reason that the respiratory movements, upon which the
function of these organs is immediately dependent, are performed
by muscles belonging to the goneral looomotory ap|)aratuR. The
nervous system of the venebrata partakes, accordingly, of the strac-
tural arrangement of the organs under its control. That portion
which presides over the locomolory, respiratory, sensitive, and in-
tellectual functions forms a system by itself, called the cerebrospinal
81/stem. This system is arranged in a manner very similar to that
of the articulata. It is compo!*ed of two equal and symmetrical
Italves, running along the median line of the body, the diQcrent
parts of which are connected by transverse and longitudinal com- fl
missiires. Its ganglia occupy the cavities of the cranium and the
spinal cannl, and send out their ncrve^t through openings in the
bony walla of iheie cavities.

I
\

OF THE NERVOUB 8TSTIH.

S61

The other portioo of llie nervous system of vertebrata is that
which presides over the functions of vegetative life. It is called
the ganffUonie, or great symjyathetic ft/atem. Its ganglia arc situated
anteriorly to the spinal column, in the visceral cavities of the body,
and are connected, like the others, by transverse and longitudinal
coromissures. This part of the oervous system is symmetrical ni
the neck and thorax, but is unsymmetriual in the aUlonaen, where
it attains its largest size and ila nuist comjilete development.

The vertebrate animals, as a general rule, are very muoh superior
to the other classes, in intelligence and activity, as well sa in the
variety and complicated character of their motions; while their
nutritive or vegetative function*, on the other band, are not particu-
larly well developed. Accordingly we find that in th^eae animals
the cerebro-spinal system of nerves preponderates very much, in
importaooc and extern, over that of the great sympathetic. The
quantity of nervous matter contained in the brain and spinal uor<l
is, even in the lowest vertebrate animal, very much greater than
that contained in the system of the
great sympathetic; and this prepon- ^'B- *26.

(lerance increases, in the higher
classes, just in proportion to their «u-

periority in intelligence, sensation, ^^^^^^, . - - ._
power of motion, and other func- ^^^^^B^^fl
tions of a purely animal character.

The spinal cord is very nearly
alike in the dilfcrcni clas-^cs of ver-
tebrate animals. It is a nearly
cylindrical cord, running from one
end of the spinal canal to the other,
and oonoecied at its anterior ex-
tremity with the ganglia of the
brain. (Fig. 126.) It is divided, by
an anterior and posterior median
flssare, into two lateral halves, which
still remain connected with each
other by a central mass or commis-
sure. Its inner portions are occupied
by gray matter, which forms a con-
tinuous ganglionic chain, running ct«i.»<.-.rr»*t.^T.rKi. »r «*.*.
from one extremity of the cord to -' (-."brun.. inrr,wii.m, .r5.*spio.t

' wti Biul BXTiM. t, 4. BrmcUlal ssit**,

the Other. Its outer portions are s. a. bmai nonM

862

OBNKBAL STRVOTUBF. AND FVSCTIOXB

composed of white substance, the filarnenta of which run fur the
most part in a. longitudinal direction, connecting the different parts
of the cord with each other, and the curd itself with tlw ganglia
of the brain.

The spinal nerves are given off from the spinal cord at regular
intervals, and in symmetrical pairs; one pair to each successire ■
jHirtion of the body. Their filainents are distributed to the integu-
ment nntl m usclcs of the corresponding regions. In serpents, where
locomotion is performed by simple, filteroate, lateral movements
of the spinal column, the spinal cord and its nerves are of the
same size throughout. But in the other vertebrate classes, where
there exist special organs of locomotion, such as fore and hind
legs, wiitgs, and the like, the spinal cord is increased in size at
the points where the nerves of these organs are given off; and the
nerves themselves, which supply the limbs, are larger than those
originntiog from other partu of the spinal cord. Thus, in th« hu-
innn subject (Fig. 126), the cervical nervta, which go to the arms,
and the sacral nerves, which are distributed to the legs, are larger
than the dorsal and lumbar nerves. They form, also, by frequent
inosculation, two remarkable plexuses, before entering their corre-
sponding limbs, vi^., the brachial plexus above, and the sacral
plexus below. The cord itself, moreover, presents two enlargentients
at the point of origin of these ncrv&s, viz., the cervical enlargement
from which the brachial nerves (4, *) are given off, and the lumbar
enlargement from which the saoml nerves (», ») originate.

ir the spinal cord be exaininct) in tnuisverse section (Fig. 127),

it will be seen that the gray
mutter in its central portion
forms a double creecentic-
shapcfl mass, with the oon-
ciiviLy of the crescents turn-
ed outward. The.*Kcrcsoentic
masses of gray matter, occu-
pying the two lateral halves
of the cord, are nnited with

FiB. 127.

I
I

Tr(u>K*rM> Si>riti>ii vrsrTiAi-Coap — ii, *
ii«r*e>o^ rl(lit atiil ir(K >ldt. •hcirlii4 ibdr lw<i ruau.
d. l)ri|[lu ..f aDlrtii'T null, «. Otifia oT pudsriui rooi.

^H each other by a transverse fl
, band of the same substance,

which is calkil the grat/
oommisaurc of the cord. Di-
rectly in front of this is a
transverse band of white substance^ connecting iu u similar manner

or TH8 NKBVOl'S STSTKX.

868

le white portions of the two lateral halves. It is called the white
eommitsure of Ou cord.

The spinal nerves originate from the conl on each side by two
distinct nwts; one anterior, and one posterior. The anterior root
(Fig. 1'27, d) arises from the surface of the cord near the extremity
of the anterior peak of gray matter. The posterior root(«) origi*
Dates at the point corresponding with the posterior peak of gray
matter. Both roots ar« composed of a considerable number of
ultimate nervous filaments, united with each other in parallel
bundles. The posterior root is diaiinguished by the prej*ence of a
small ganglion (c), which appears to be incorporated with it, and
through which its Qbres pass. There is no such gnngUou on the
anterior root. The two roots uitito with each other shortly after
leaving the cavity of the spinal canal, and mingle their filaments
in a single trunk.

It will be Been, on referring to the diflgram (Fig. 127), that each
lateral half of the apinal cord is divided into two portions, au
anterior and a posterior portion. The posterior [wak of gray mat
ter comes quite up to the aurfacc of the cord, and it is just at this
point (e) that the posterior roots of the nerves have their origin
The whole of the white substance iueluded between thin point and
the posterior median fissure is called the posterwr column of the
cord. That which is included beiwcou the same point and the
anterior median fissure is the anterior column of tfie cord. The
white auKstance of the cord may then be regarded as consisting
for the roost part of four longitudinal bundles of nervous filament*,
Tiz., the right and left anterior, and the right and left posterior
columns. The posterior median fissure penetrates deeply into the
substance of the cord, quite down to the gray matter, so thnt the
posterior colunma appear entirely separated from each other in a
transverse section; while the anterior median fissure is more shal-
low and stops short of the gray matter, so that the anterior columns
are connected with each other by the white commissure above men-
tioned.

By the encejJiaian we njean the wluile of that portion of the
OArebro'Spinal system which is contained in the cranial cavity. It
IB divided into three principal parts, vi;;., the cerebrum, cerebellum,
and medulla oblongata. The anatomy of iheas parts, though some-
what complicato<i, can be readily un<lerstood if it be recollected
that they are simply a double serifs of uetvous ganglia, conturied u.'iih
tach other and with the 9pi»al cord by Imnsverte and hn-jitttdinai

864

OKNERAI. BTRtTCTURE a:T1) FUyCTIOSS

Pip. I2f.

n^t

commitaurea. The number and relative size of these ganglia, in
diflerent kinds of animals, depend upon the perfection of the bodily
organization in general, and nnoro especially on tbat of the intelli-
gence and the special senses. They are moet readily described by
commencing with the simpler furma and termiDatiDg with the more
oomplex.

The brain of the AUiyator (Fig. 128) consists of fire pair of
ganglia, ranged one behind the other in the interior of the craniom.
The first of ihcse arc two rounded nias8e«(i), lying juat above and

behind the nasal cavities, which disiii-
bute their nerves upon the Schneideriu
mucoaa membrane. These arc tbeoJrt«-
tori/ ^cotfflia. They are coDnectod wttit
the rest of the braio by two long and
slender commissures, the "olfactory con-
miwiures.'' The next pair(i) are som*-
what larger and of a triangular sbap^
when viewed from above downwanL
They are termed the "cerebral ganglia,"
or the hemispherts. Immediately follow-
ing them are two quadrangular niBsaes(i|
which give origin to the optic nonres, and
are therefore called the opti'e ganglia.
They are termed also the "optic tuber*
cles;^' and in some of the bighcr animals,
where they present an imperfect division
into four nearly equal parts, they are
known as the "tuberculaquadrigeroina."
Behind them, we have a single triangular collection of nervous
matter (4), which is called the eerebellum. Finally, the upper por-
tion of the cord, just behind and beneath the cerebellum, is aeeo to
be enlarged and spread out laterally, so as to form a broad oblong
mass (a), the medulla oblongata. It is from this latter portion of the
brain that the pneumogastrie or respiratory nerves originate, aad
its ganglia are therefore somctimcd term^ the "pneumogaatrie* or
"respiratory" ganglia.

It will be seen that the posterior columns of the oord, as they
diverge laterally, in oriler to form tho medulla oblongata, leave b^
twecn them an open space, which is oootinuous with the posterior
median fissure of the cord. This apaco ia known as the "foartli
ventricle.'* It is panially covered in by the backward projtidioo

Sbai:! or Ai.Lin jltoh.— I. UI-
Opik loWrel**. 1. C«i«b«llUD. S.

OF TUE NtERVOUa SYSTEM.

865

of the cerebellum, but in the alligator is stilt sotnewhnt open pos-
teriorly, presenting a kind of cliasm or gap between the two liiteral
halves of the medolla oblongata.

The successive gaoglin which conipnfte the bruin, being arranged
in pairs aa above described, are separated from each other on the
two sides by a longitudinal median fisanre, which ia continuous
irith the posterior median tissure of the cord. In the broin of the
Alligator this 6ssure appears to be interrupted at the cerebellum;
but in the higher clasaea, where the lateral portions of the cerebel-
lum arc more highly developed, as in the hnman subject (Kig. 126),
they are also separated from each other posteriorly on the median
Jine, and the longitudinal median fissure is complete throughout.

In birds^ the hcmiapheres are of much larger size than in rep-
tiles, and partially conceal the optic ganglia. The cerebellum,
filso, is very well developed in this class, and presents on its sur-
face 8 number uf transverse foldings or convolutions, by which
the quantity of gray matter which it conlaina is considerably in-
creased. The cerebellum here extends so far backward as almost
completely to conceal the medulla oblongata and the fourth ventricle.
In the (luadruprds, the hemispheres and cerebellum attain a still
greater size in proportion to the remaining parts of the brain.
There are also two other pairs
of ganglia, situated beneath the
liemispberes, and lietween them
nnd the tubercula quadrigemina.
Theae are the corpora striata in
front and the cpiic Oialamx behind.
In Fig. 1*29 is shown the brain of
the rabbit, with the hemispbertrs
laid open and turn(xl afii<)o, so as
to show the inleraal parts in their
natural situation. The olfactory
ganglia are seen in front (i) con-
nected with the remaining parts
hy the olfactory commissures.
The separation of the hemi^plieres
(i, *) shows the corpora striata (i)
and the optic thalami (<). Then
come ibe tnbercula quadrigemina
(•), which are here composed, as
above mcntiunod, of four rounded masses, nearly equal in sise.

Fig. 126.

BH«l*or iliBDCT, rlrwe-l fr.nn nlxitr —
I. lllfDDlar)' pDKtIa I K«ii>l*, hnroi. Iiinied
K'ld*. 3. Ci.r^uta alrlnla. 1. I>|ill4 ll.aliiiHl.
0. TnbMvnU i|iLiii]rl(«iu1UB. t. Caial«!Jam.

366

OSySBAL STRTCTIRE AMD FtIKCTION'8

The cerebellum (•) in consiilerably enlargefl by the development of
its laleml portions, and showa nn abundance of transverse convola-
tiong. It conccaU from view the fourth ventricle and most of the
medulla oblongata.

In other species of quadrupeds the hemispheres increase in size
so as to prujoct entirely over the olfactory ganglia in front, and to
cover in the tubercula quadrigemina and the cerebellum behind.
The Borface of the hemiRpheres also becomes covered with nume-
rous convolutions, which are curvilinear and somewhat irregular
in form and direction, insteojd of being transverse, like those of the
cerobellum. In man, the development of the hcmi.'^pheres reaches
its highest point; so that they preponderate altogether in size over
the rest of the ganglia constituting the brain. Id the human brain,
accordingly, when viewed from above downward, there is nothing
to be seen but the convex surfacea of the hemispheres; and even
in a posterior view, as seen in Fig. 126, they conceal everything
bat a portion of the cerebellum. All the remainiDg parts, how-
ever, exist even here, and have the same connections and relative
eitUBtion as in other instances. They may be best studied in the
following order.

As the spinal cord, iti the human subject, passes upward into the
cranial cavity, it enlarges into the medulla oblongata as already
described. The medulla oblungnta presents on each side three pro-
jections, two anterior and one pogterior. The middle projections
on its anterior surface (Fig. V60, i, i), which
Pig. 190. are called the ajitenor pymmidt, are the con-

tinuution of the nnteriur columns of the
cord. They pass onward, underneath the
transverse fibres of the pons Varolii, run up.
[i\f 'fsi r^ ward to the corpora striata, pass through
these bodies, and radiate upwan) and outward
from their external surface, to terminaie in
the gray matter of the hemispheres. The
projections immediately on the outside of
the anterior pyramids, in the medulla ob-
longata, arc the olivary bodies («, »). They
contain in their interior a thin layer of
gray matter folded upon itself, the functions
and connections of which are but little un-
deraUxHl, and are not, apparently, ol' very
grent importance.

yiprm llnr.niuiiTA
«*r llriiH Bka'k. HBO.
riur Tl»ir.— I, 1. Autetlor VT'

3 3. KMIiroTin bodlfi. i D«-
cu«B*llua (it Il>c ftnttnor m-
liiBiaa. Thx mnliilli. obloDn-
* k I* r»cn l*mili»<rd BboTg
Lj- tliii Irsiuicru fiblM ul Lbe
|><is« VaMllL

OF THE NERVOUS 8TBTBM.

867

The anterior columns ot the cord present, al the lower part of the
medulla oblongata, a reatarkable ihterchaage or crossing of Lheir
fibres (4). The fibres of the left anterior column pass acniss the
median line at ihts spot, and becoming continuous with the right
anterior pyramid, ar« finally distributed to the right side of the
cerebrum; while the 6bres of the right anterior column, passing
over to ibo Icfl anterior pyramid, are distributed to the lufi aide of
the cerebrum. Thia interchange or crossing of the nervous fibres
is known as the decussation of the anterior columns 0/ the cord.

The pofiterior columns of the cord, as they diverge on each side

of the fourth ventricle, form the posterior and lateral projections of

the medulla oblongata (*, a). They are sometimes called the "res-

tiforra bodies," and are extremely important parts of the brain.

They consist in great measure of the longitudinal i)lament« of

the posterior columns, whii.'h pass upward and outward, and are

<]iBtributed partly to the gray matter of the cerebellum. The

remainder then pass forward, underneath the tubcrcula quadn-

geminii, into and through the optic thntami; and radiating thence

upward and outward, are distributed, like the continuation of the

anterior columns, to the gray matter of the cerebrum. The resli-

form bodies, hotrever, in passing upward to the cerebellum, arc

supplied with some fibre* from the anterior columns of the cord,

which, leaving the lower portion of the anterior pyramida, join the

reatiform bodies, and are distributed with them to the cerebellum.

Krom this dcocription it will be seen thnt both the cerebrum and

the cerebellum arc supplied with Slaments from both the anterior

and posterior column.-* of the cord.

In the substance of each reatiform body, moreover, there is im-
bedded a ganglion which gives origin to the pneumogastric nerve,
and presides over the funcciont; of respiration. This ganglion is
Eorroanded and covered by the longitudinal fibres passing upward
from the cord to the cerebellum^ but may be discovered by cutting
into the substance of the resliform body, in which it is buried. It
is the first important ganglion met with, in dissecting the brain
from below upward.

While the anterior columns are passing beneath the pons Varolii,
Ibey form, together with the continuation of the pcstcrior columns
and the transverse fibres of the poas itsi^lf, a rounded prominence
or tuberosity, which is known by the name of the tuber annuUirc.
In the deeper portions of this protuberance there is situated, among
the longitudinal fibres, another collection of gray matter, wliich

SA8

GXNBRAL STRUCTURE AND FPNCTIONS

though not of large size, has very important functions and coaneo*
tions. This is known iia the ^an'jiiim of the tuber atmntare.

Situated almost immcfiintely ubovc these parts wo havo the cnr*
pora striata in front, and the optic thalami behind, nearly eqnal id
aize, and giving passage, aa above described, to the fibres of the
anterior and posterior colnmns. Behind them stili, and on a littld
lower level, are the tubercula qnadrigemina, giving origin to tha
optic nerves. The olfactory ganglia rest upon the cribriform plat«
of the ethmoid bone, and send the olfactory filaments through the
perruratioQs in this plate, to be distributed upon the mucous mem-
brane of the upper and middle turbinated bones. The cerebellum
covers in the fourth ventricle and the posterior surface of the
medulla oblongata; and finally the cerebrum, irhich has attained
the si^e of the largest ganglion in the uraniol cavity, extends so far
in all directions, forward, backward, and laterally, as to form a con-
voluted arch or vault, completely covering all the reinainiog parla
of the encephalon.

The entire brnin may therefore be regarded as a connected aeries
of gnnglia, the arrungeinent of which is shown in the accompany-
ing diagram. (Fig. ISl.) These

Pig. I3t,

ganglia occur in the following
order, counting fVom before back*
ward: Ist, The olfactory gan-
glia. 2d. The cerebrum or hemi-
spheres. 3d. The corpora striata.
4th. The optic thalami. 5th. The
tul>ercula quadrigemina. 6tb.
The cerebellum. 7ih. The gan-
glion of the tuber annulare. And
8lh. The ganglion of the medulla

oblongata. Of these ganglia, M
..».. «.»i »»» ■

only the hemispheres and cere-
bellum are convoluted, while iho
remainder are smooth and round*
ed or somewhat irregular ia
shape. The course of the fibres
ooming from the anterior and
posterior columns of the cord is also to be seen in the accompany-
ing figure. A portion uf the anterior fibres, we have already ob*
served, pass upward aud backward, with the restiform bodies, to the
cerebellum; while the remainder run forward through the tuber

DIkfram irf II i- o * << H k 4 i ■ . In rertlntt nrr-
Uau, abuirliig III* ■llnalloB of th* dtffpntnt ,pia-
fll^ knd lh< covr*« nf Ihfi thrvt. I, tmat\'ity
finfUnn. ]. Hdniaphaio 3 Corpiii ■irlaluni.
4. Upllo IhaUmu*. l. Tabercnli qiuJrlfti&lQk
B. OiabrllaiD. 7. IIivkIIiid of Inbcr ■ooaUrv
9. OkaKlloaof nedullBablaant**

OF THE NERVOUS 8TSTEM. 869

aoDolare and the corpus Btriatum, and then radiate to the gray
matter of the cerebram. The posterior fibres, constitating the res-
tiform body, are distributed partly to the cerebellum, and then pass
forward, as previously described, underneath the tubercula quadri-
gemina to the optic thalami, whence they are also finally distributed
to the gray matter of the cerebrum.

The cerebram and cerebellum, each of which is divided into two
Jateral halves or "lobes," by the great longitudiqal fissure, are both
provided with trausverse commissures, by which a connection is
vatablished between their right and left sides. The great trans-
verse commissure of the cerebrum is that layer of white substance
-vhicb is situated at the bottom of the longitudioal fissure, and
'vhioh is generally known by the name of the " corpus callosum."
3t consists of nervous filaments, which originate iVom the gray
xnatter of one hemisphere, converge to the centre, where they be-
«M>iDe parallel, cross the median line, and are finally distributed to
'She corresponding parts of the hemisphere upon the opposite side.
TThe transverse commissure of the cerebellum is the pons Varolii.
Hts fibres converge from the gray matter of the cerebellum on one
aBide, and pass across to the opposite ; encircling the tuber annulare
'^th a band of parallel curved fibres, to which the name of " pons
"Varolii" has been given from their resemblance to an arched bridge.
The cerebro-spiual system, therefore, consists of a series of gan-
.^lia situated in the cranio-spinal cavities, connected with each other
%y tranisverse and longitudinal commissures, and sending out nerves
'fto the corresponding parts of the body. The spinal cord supplies
"Khe int^nment and muscles of the neck, trunk, and extremities ;
"^rhile the ganglia of the brain, beside supplying the corresponding
^larts of the head, preside also over the organs of special sense, and
^perform various other functions of a purely nervous character.

870

OP ITBBVOrB TBBITABTLITT

CHAPTER II.

OF MEBVOUS IRRITABILITY AND ITS MODK OF

ACTION.

We have already meotioDed, io a previous citapter, that every
organ in the body is enduwed with the property of irritabiUty: that
is, the property of reacting In some peculiar manner wlicn subjected
lo the action of a direct stimulus. Thus the irritability of a gland
shows itself by increased secretion, that of the capillary vessels by
congestion, that of the muscles by coutraetion. Now ibe irritability
of the muscles, indicated as above by their contraction, is extremely
serviceable as a means of stadying and exhibiting nervous pheno-
tneoa. We shall therefore commence this cbapter by a study of
some of the more important facts relating to muscular irritability.

77ie irrilabitity of lite mxtsGies is a property inherent in dte mitscular
fthrc itstlf. The existence of muscular irritability cannot be ex-
plained by any known physical or chemical laws, so far as they
relate to inorganic substances. It must be regarded simply as a
peculiar property, directly dependent ou tlie structure and consti-
tution of the muscular fibre; just as the property of emitting light
belongs to phosphorus, or thai of combining with metals to oxygen.
This property may be called iuto actiuu by various kinds of stimu-
lus; OS by pinching the muscular fibre, or pricking it with the point
of a needle, the application of an acid or alkaline solution, or the
discharge of a galvanic buttery. All these irritating applications
arc immediately followed by contraction of the muscular fibre.
Tills contraction will even take place under the microscope, when
the fibre is entirely isoktei), and removed from contact with any
other tissue; showing tliat the properties of contraction and irrita-
bility reside in the fibre itself, and are not communicated to it by
other parts.

Afum-uiar irntainlity cxmtinnea for a certain time after death. The
stoppage of respiraiion and circulation does not at once destroy
the vital properties of the tiasues, but nearly all of them retain
these properties to a certain extent for some time afterward. It is
only when the constitution of the tissues has become altered by

AKD ITS HODB OP AGTIOIT.

S71

being deprived of blood, and by the consequent derangement of
tbe nuiritivo process, tliat tliuir characteristic properties arc finally
lost. Thus, in the mnscles, irritability and contractility may be
easily shown to exist for a short lime after death by applying to the
exposed muscular 5bre the same kind of stimulus that wo have
already foand to affect it during life. It is easy to see, in the
muscles of the ox, after the animal has been killed, flayed, and
eTiscerated, different bundles of muscular fibres contracting irregu-
larly for a long time, where they are exposed to the coniaet of the
air. Even in the human subject the same phenontenoa may be
seen in eases of amputation; the exposed musclesof the amputated
limb frequently twitching and quivering for many minutes after
their separation from the body.

The duration of muscular irritability, after death, varies consi-
derably in different classes of anirnuls. It disappears most rapidly
in those whose circulation and respiration are naturally the most
active; while it continues for a longer time in those whose circula-
tion and respiration are sluggish. Thus in birds the muscular
irritability continues only a few minutes after the death of the
«ni[oal. In quadrupeds it lasts somewhat longer: while in reptiles
it remains, under favorable circumstances, for many hours. The
«aase of this difference is probably Ihut in birds and c^uadrupcds,
th« tissues being very vascular, and the molecular clmnges of nu-
trition going on with rapidity, ibe constitution of the muscular
fibre becomes so rapidly altered after the circula-
tion has ceased, that its irritability soon disappears. pi^, 132.
^n reptiles, on the other hand, the tissues are less
-vascular than in birds and quadrupeds, and all the
nutrilivc changes go on more slowly. Kespiration
and circalutioa can therefore be dispensed with for
a longer period, before the constitution of the tig-
sues becomes so much altered as to destroy albo-

Lgether their vital properties.
Owing to this peouliarity of the cold blooded
uimals, their tissues may be used with great ad-
vantage for purposes of experiment. If a frog's
leg, for example, be separated from the body of
tbe animal (Fig. 132), the skin removed, and the
poles of a galvanic apparatus applied to the sur- f,o„-, i,,„,
faoe of the muscle (a, b), a contraction takes place "^'^ i™'"* °' «»'-
every time the circuit w completed and a discharge utUBi,ucu.»in,i.

372

or UTEBVOUS IBBITABILITT

passed -througli the tissues of the limb. The leg of the frog, pre-
pared in this way, may be employed for a long lime for the pur-
pose of exbibitiog tlie e&'ect of various kinds of stimulus upon the
musclea. AW iho mechanical and chemical irritants which w«
have mentioned, pricking, pinching, cauterization, galvaniam, &A.,
act with more or less energy and promptitude, though the raoet^
efficient of all is the electric discharge.

Continued irriiatipti exhausts llie irritahiUty of Oie m.useles. It ia
found that the irritability of the muscles wears cat after death more
rapidly if they bo artificially excited, than if they be allowed to
remain at rest. During life, the only habitual excitant of mus*
colar contraction ia the peculiar stimulus conveyed by the nervea>:
Afler death this stimulus may be replaced or imitated, to a certain
extent, by other irntanla; but their appHcation gradually exhausta
the contractility of the muscle and hastens its final disappearance.
Under ordinary circumstances, the post-mortem irritability of the
moacle remains until the commencement of cadaveric rigidity.
When this has become fairly eatablished, the muscles vrill no longer
contract under the application of an artificial stimulus.

Certain poisonous subatancca have the power of destroying the
irritability of the muscles by a direct action upon their tissue.
Sulphocyanide of potaasium, for example, introduced into the cir-
culation in suflicient quantity to cause death, destroys entirely the
muscular irritability, so that no contraction can afterward bo pro-l
duced by the application of an external stimulant.

Nervous Irn'iabilitij. —The irritability of the nerves is the pro-
perty by which they may be excited by an external stimulus, so as
to be called into activity and excite in their turn other organs to
which their Diaments are dintributed. When a norvo is irritated,
therefore, its power of reaction, or its irritability, can only be esti-
mated, by the degree of excitement produced in the oi^n to which the
nerve is distributed. A nerve running from the integument to the ■
brain produces, when irritated, a painful sensation; one distributed |
to a glandular organ produces increased aeoretion; ooe distributed
to a muscle produces contraction. Of all these effects, muscular
contraction is found to be the best test and measure of nervous
irritability, for purposes of experiment. Sensation cannot of course
be relied on for thi? purpose, since both consciouanoas and volition
are abolished at the time of death. The activity of the glandular
organs, owing to the stoppage of the ciroulation, disappears aHaa
very rapidly, or at least cannot readily be demonstratetl. The

AND ITS HODB OF ACTION.

873

Fig. 133.

oontractilitj of the muscles, however, lasts, as we have seen, for a
considerable time after death, and may accordingly be employed
with great readiness as a test of nervous irritability. The manner
of its employment is as follows : —

The leg of a frog is separated from the body and stripped of its
integument; the sciatic nerve haying been previously dissected
out and cut off at its point of emergence from the
spinal canal, so that a considerable portion of it
remains in conDection with the separated limb.
(Fig. 183.) If the two poles of a galvanic appa-
ratus be DOW placed in contact with different
points (a h) of the exposed nerve, and a discharge
allowed to pass between them, at the moment
of discharge a sudden contraction takes place in
the muBcles below. It will be seen that this ex-
periment is altogether different from the one re-
presented in Fig. 182. In that experiment the
galvanic discharge is passed through the muscles
Uhemselves, and acts upon them by direct stim-
xi\uB. Here, however, the discharge passes only
from a to 5 through the tissues of the nerve, and
acts directly upon the nerve alone; while the
iierTe, acting upon the muscles by its own pecu-
liar agency, causes in this way a muscular con-
'ftraction. It is evident that io order to produce
'fthis effect, two conditions are equally essential : Ist.
TTbe irritability of the muscles; and 2d. The irri-
ability of the nerve. So long, therefore, as the
■nuBcles are in a healthy condition, their contraction, under the
inflaence of a stimulus applied to the nerve, demonstrates the irri-
tability of the latter, and may be used as a convenient measure of
its intensity.

The irritability of the nerve continues aftxr death. The knowledge
of this &ct follows from what has just been said with regard to ex-
perimenting upon the frog's leg, prepared as above. The irrita-
Inlity of the nerve, like that of the muscle, depends directly upon
its aqatomical structure and constitution; and so long as these re-
maiD unimpaired, the nerve will retain its vital properties, though
respiration and circalatioa may have ceased. For the same reason,
also, as that given above with regard to the muscles, nervous irri-
tability lasts much longer after death in the cold-bloodeii than in

FKoa'a Lia.wllh
■dalle Derrs (If) ■!■
lachBd.— aA. Poletof
gftlTkDie bdlterj, ap-
plied Io nerve.

874

^ons iRRiTAQiLirr

the warm-blowJeJ animals. Various artificial irritants may be em-
ployed to call it into activity. TiDcliing or pricking the ei{.>0!«d
nerve with steel instrumcnta, the applicatiou ofcntistic liquids, lad
the passage of galvanic discharges, ill have this eQect The cUctrc
current, however, is mnch the beat means to employ for this par
pose, &inc« it is mom delicato in ita operation than the others, lal
vrill continue to succeed for a longer time.

The nerve is, inileed, so exceedingly senailive to the electric cur-
rent, that it will respond to it when insensible to all other kinds of
stimuliw. A frog's leg freshly prepared with the nerve fttttchtd,
80 in t'ig. 13S, will react so readily whenever a discharge is pajsa)
through tlie nerve, that it forms an extremely delicate instraraent
for detecting the prc.<;enco of electric currents of low intensity, and
has even been used for this purpose by N[atteucci, under the intnc
of the "galvanosoopio frog." It is only necessary to introduce the
nerve as part of the olectrio circuit; and if even a very feeble car-
rent be present, it is at once betrayed by a muscular contraction.

The superiority of electricity over other moons of exciting nerr-
OQS action, audi aa mechanical violence or chemical agents, pnv
bably depends upon tbe fact that the latter neoessarily alter and
diaitiLe^rate more or less the euhstanco of the nerve, so that its irri-
tability soon disappears. The electric current, on the other bind,
excites the nervous irritability without any marked injury to the
substance of the nervous fibre. Its action may, therefore, be cea-
linued for a longer period.

Xervous irritabUiOj^ tike that of the mumlea, u exhausted by rtfuaiid
excitement. If a frog's leg be prepared aa above, with the srialic
nerve altnched, and allowed to remain at rest in a damp and coot
place, where its tissue will not become altered by desiccation, the
nerve will remain irritable for many hours; but if it be excited,
soon ader its separation from tlie body, by repeatetl galvanic shocks
it soon begins to react witti diminished energy, and becomes gra-
dually less and less irritable, until it at lost ceaaca to exhibit aaj
further excitability. If it be now allowed to remain for a time at
rent, itit irritability will be partially restored; and muscular contrao-
tion will again ensue on the application of a stimulus to the nervr.
Exhausted a second time, and a second time allowed to repose, it
will again recover itself; and this may even be repeated sevend
times in successiou. At each repetition, however, the recovery of
nervous irritability is less complete, until it finally disappears alio-
geiber, and can no longer be recalled.

AVD ITS HODS or ACTION. 876

Various accidental circa instances tend to diminish or destroy
nervous irritability. The action of the woorara poison, for example,
destroys at once the irritability of the nerves; so that in animaU
killed by this substance, no muscular contraction takes place on
irritating the nervous trunk. Severe and sudden mechanical inju-
ries oi^n have the same effect ; as where death is produced by
violent and extensive crushing or laceration of the body or limbs.
Such an injury produces a general disturbance, or shocJc as it is
called, which affects the entire nervous system, and destroys or
saspends its irritability. The effects of such a nervous shock may
frequently be seen in the human subject afler railroad accidents,
where the patient, though very extensively injured, may remain
for some hours without feeling the pain of his wounds. It is only
after reaction has taken place, and the activity of the nerves has
been restored, that the patient begins to be sensible of pain.

It will oflen be found, on preparing the frog's leg for experiment
as above, that immediately after the limb has been separated from
the body and the integument removed, the nerve is destitute of
irritability. Its vitality has been suspended by the violence in-
flicted in the preparatory operation. In a few moments, however,
if kept under favorable conditions, it recovers from the shock, and
r^ins its natural irritability.

The action of the galvanic current upon the nerve, as first shown
hy the experiments of Matteucci, is in many respects peculiar. If
ihe current be made to traverse the nerve in the natural direction
of its fibres, viz., from its origin toward its distribution, as from a
to 6 in Fig. 133, it is called the direct current If it be made to
pass in the contrary direction, as from 6 to a, it is called the inverse
CTurent. When the nerve is fresh and exceedingly irritable, a
muscular contraction takes place at both the commencement and
termination of the current, whether it be direct or inverse. But
very soon afterward, when the activity of the nerve has become
somewhat diminished, it will be found that contraction takes place
only at the commencement of the direct and at the termination of the
inver$e current. This may readily be shown by preparing the two
legs of the same frog in such a manner that they remain connected
with each other by the sciatic nerves and that portion of the spinal
column from which these nerves take their origin. The two legs,
BO prepared, should be placed each in a vessel of water, with the
nervous connection hanging between. (Fig. 134.) If the positive
pole, a, of the battery be now placed in the vessel which holds leg

376 OF NEBTOUS IRBtTABILITT

No. 1, and the Degatlve pole, i, in that ooDtaioing 1^ "So. % itwiQ
be seen that the galvanic current will traverse the two legs in op-
posite directions. In No. 1 it will pass in a direotion contrary to
the course of ita nervous 6bres, that is, it will be for thia leg u

Fig. 134.

inverse current; while in No. 2 it will pass in the same direction
with that of the nervous Bbres, that is, it will be for this leg a dutd
current It will now be found that at the moment when the d^
cuit is completed, a contraction takes place in No. 2 by the direct
current, while No. 1 remains at rest; but at the time the oircoit ii
broken, a contraction is produced in No. 1 hy the inverse current,
but no movement takes place in No. 2. A sncceaaion of alternate
contractions may thus be produced in the two lega by repeatedly
closing and opening the circuit If the position of the polea^ a, b,
be reversed, the effects of the current will be changed in a oatr^
spending manner.

Atler a nerve has become exhausted by the direct cnrrent, it it
still sensitive to the inverse; and afler exhaustion by the invene,
it is still sensitive to the direct It has even been found by Hat-
teucci that after a nerve has been exhausted for the time by the direct
current, the return of its irritability is hastened by the snbseqnest
passage of the inverse current; so that it will become again sena-
tive to the direct current sooner than if allowed to renudn at rat
Nothing, accordingly, is so exciting to a ner^ as the passage of
direct and inverse currents, alternating with each other in rapid
succession. Such a mode of applying the electric stimulaa ia ^itt
usually adopted in the galvanic machines used in medical praotiee^
for the treatment of certain paralytic affections. In these maohiiui,

AND ITS MOD£ OP ACTION.

877

e electric circnit is alternately formed and broken with great
rapidity, thus producing the greatest effect upon tbe nerves with
the smallest expenditure of electricity. Such alternating currents,
however, if rery powerful, exhaust the nervous irritability more
rapidly nod completely than any other kind of irritation; and id
an animal killed by the action of a battery used in this manner, the
nerves may be found to be entirely destitute of irritability from the
moment of death.

The irri(a.hiUty c^ the r\erves xs distinct from that of the muactes; and
the two may be destroyed or sospended independently of each other.
When the frog's leg has been prepared and separated from the
body, with the sciatic oerve attached, the muscles contract, as we
have seen, whenever the nerve is irritated. The irritability of the
nerve, therefoi-e, is manifesteil in this instance only through that of
the mDaclc, and that of tbe muscle is called into action only through
that of the nerve. The two properties may be separated from each
other, however, by tbe action of iwwrara, which has the power, as
first pointed out by Bernard, of destroying the irritability of the
nerve without affecting that of the muscles. If a frog be poisoned
by this subsLance, and the leg prepared as above, the poles of a
galvanic battery applied to the uerve will produce no eflfect; show-
ing that the nervous irritability has ceased to exist. But if the
galvanic discharge be passed directly through the muscles, contmc-
lion at once takes place. The muscular irritability has survived
that of the nerves, and must therefore be regarded as essentially
distinct frcnn it.

It will bo recollected, on the other hand, that in cases of death
from the action of sulphooyanide of potassium, the muscular irri-
tability is itself destroyed; so that no contractions occur, even whea
the galvanic discharge is nuwle to traverse tbe muscular tiiisue.

There are, therefore, two kiuds of paralysis: first, « muscular
paralysis, in which the muscular fibres themselves are directly
aifcctcd; and second, a nervous paralysis, in which the affection is
confined to the uervous filaments, the muscles retaining their natural
properties, and being still capable of contracting under the iutlueuoo
of a direct stimulaa.

Nature of the Xervons Force. — It will readily be seen that the

ous force, or the agency by which the nerve acts upon a muscle

and causes its contraction, is entirely a peculiar one, and caunot be

regarded as either chemical or mechanical in its nature. The force

hich is exerted by a nerve in a state of activity is not directly

01 a

^^icrvi

378

rSBVODS IBRlTABIUTr

appreciable in any vaj hy ihe senses, and can be judged of only
by its eOtiOt in causing rnusoutar contrHCtiun. This peculiar vitality
of the nerve, or, as it is sornetioies called, the " nervous force," does
not precisely resemble in its operation any of the known physical
forces. It Kfts, however, a partial rcaomblancc in some respects to
eleulricity; and this lias been sulTicieiU tu lead soiuo writers iato lb«
error of regarding the two as identioal, and of supposing electricity ■
to be rcully the force acting in the nerves, and ojicrating throngb
them upon the muscles. The principal points of resemblance
existing between the two forces, and which have been used la
Bappurt of the above opinion, are the following : —

1st. The identity of their effects upon the muscular fibre.

2d. The rapidity and peculiarity of their action, by which the
force is transmitted almost instantaneously to a distant point, with-
out producing any visible effect on the intervening parts.

Sd. The extreme sensibility of nerves to the electric current; aud

4th. The phenomena of electrical fishes.

As these considerations are of some importance in settling iho
question which now occupies us, we shall examine them in succes*
sion.

let. The Identity of their Efffcla upon the Muscular Fibre. — It is'
very true that the muscular fibre contracts under the influence of I
electricity, as it does under that of the ncrroua force. Thts fact,
however, does not show the identity of the two forces, but only
thai they are both capableof producing one particular pheoomenoii;
or that electricity may replace or imitate the nervous force in its
action on the muscles. But there are various other agents, as we
have already seen, both mechanical and chemical, which will pro-
duce the same eStxi, when applied to tlie muscular tissue. Elec-
tricity, therefore, is only one among several physical forces which
resemble each other in this respect, but which are not oo that
account to be regarded as identical.

2d. The Jiapidtty amd I*eculiariltf tif Iheir Action, hy which the
force is Iransmiittd almost inslaniauetmslt/ to a dislant pm'jity without
producing any vi^sible effect on the I'n/eriwun^ parts. — This is a Tery
remarkable and important character, both of the nervous force and
of electricity. In neither case ia there any visible effect produced
on the nervous or metallic fibre which acts as a conducting medium ;
but the final action is exerted upon the substance or organ with
which it IB in connection, ^o definite conclusion, however, can
be properly derived from the rapidity of their traosmission, sinco.

AKD ITS MODB OF ACTTON*.

S7fi

this rapidity has never been accurately measured in either instance.
"We know that light and sound both travel with much greater
rapidity than most other physical forces, and that electricity is more

k-TBpid in its traDsmiaaion than either; but there is no evidenco that
the velocity of the latter and that of the nervous force are the same.
We can only say that in both instances the velocity is very great,
without being able to compare them together with any degreA of

[^cccQracy. The mode of traDsmisfion, moreover, alluded to above,
is not peculiar to the two forces which are supposed to be identical.
Light, for example, is transmitteii like them through conducting
media, without producing in its passage any sensible eflect until it
meets with a body capable of reflecting it. In the intcrvfll, there-
fore, between the luminous body and the rejecting one, there ix
the siCtne apparent want of action as in the nerve, between the point
at which the irritation is applied and its termination in the mus
cular tissue.

Sd. The extreme SemibiHty of Nerve» to the Ekciric Current. — It
has already been mentioned that the electric current is the most
delicate of all the mean<i of irritation that may be applied to the
nerve after death ; and that it may be uaed with less deleterious
effect than any other. The evident reason for this, however, hap

, already been given. Electricity is one among several physical

''■j^uls by which the nerve may be artiticiiilly excited after death.
It is Jess destructive to the nervous texture than any other, and
consequently exhausts its vitality less rapidly. All these agents
vary in the delicacy of their operation; and though the electric
current happens to bo the rAoat ellicient of all, it is still simply an
artificial irritant, like the rest, capable of imitating, in its own way,
the natural stimulus of the nerve.

4lb. The Pfterumenao/ Eiectrical Fishes. — It has been fully demon-
Btrated that certain fish (gymnotus and torpedo) have the power of
geoerating electricity, and of producing cloctrio discharges, which
are ofVen sufficiently powerful to kilt small animals that may come
within their reach. That the force generated by these animals is
in reality electricity, is beyond a doubt. It is conducted by the
same bodies which serve as conductors for electricity, and is stopped
by those which are non-conductors of the same. All the ordinary
phenomena produced by the electric current, viz: the heating and
melting of a fine conducting wire, the induction of secondary
carrenta and of magneti.sm, the decomposition of saline solutions,
and even the electric spark, have all been produced by the force

S80

OP K1RT0U8 IRRITAB11.ITT

geoeratcd by iliose animala. There is, accordingly, no room for'
doubt as to its nature.

This fact, however, is very far from demonstraUng the electric
character of the nervous force in general. It ia, on the contrary,
directly opposed to such a supposition; since the gymnotus and
torpedo are capable of generating electricity simply because they
have a special organ dtatined for tin's purpo$e. This organ, which is
termed the "electrical organ," is peculiar to these 63h, and where
it is absent, the power of generating electricity is absent also. The
electrical organu of the gymnotus and torpedo occupy a considerable
portion of the body, and are largely supplied with nerves which
regulate tbclr function. If these nerves be divided, tie<l, or injured
in any way, the electrical organ is weakened or paralyzed, just as
the muscles would be if the nerves distributed to them were sub-
jected to a similar violence. The electricity produced by these
animals is not supplied by the nerves, but by a special generating
organ, the action of which is regulated by nervous influcnco.

The reasons quoted above, therefore, are quite iosufficieol for
eslabUsbing any relation of identity between the nervous force and
electricity. There are, moreover, certain well authenticated facts
directly opposed to such a supposition, the most important of which
arc the following: —

The first is, that no electrical current has been aciuaUy foxmd to exist
in an irriltUed nerve. The most conclusive ex|)eriments on this point
are thoRO which were made by Longet and Matteucoi, in company
with each other, at the veterinary scliuol of Alfort,' The galvano*
meter employed in these investigations was constructed under the
personal dircclionof the experimenters, and was of extreme delicacy.
The oscillating needle was surrounded by 2500 turns of oonductiug
wire, and the poles were each armed with a platinum plate, having
an exposed surface of onc-aixth of a square inch. When the poles
of the apparatus had been repeatedly immersed tn spring water, so
that no further variation was produced from this source, the instru-
ment was considered as ready for use. The sciatao nerve of a liv-
ing horse was then exposed, and the poles of the galvanometer
placed in contact with it^ in various positions, both diagonally and
longitudinally, and at variouadeptha in its interior. The examina-
tion was continued for a quarter of an hour, during which time the
painful sensations of the animal were testilie{l by constant strog*
gling movements of the limbs; showing that both the motor and

■ LoDgot, TralU de Pbrsiologie.. P«li, l$£0, rol. U. p. 190.

AND ITS ICODE 0? ACTION. 381

sensitive filaments of the nerve were in a high state of activity.
The conclusion, however, to which the experimenters were con-
dncted was the following, viz: that "there was no constant and re-
liable evidence of the existence of an electric current in the nerve."

Secondly. The mode of conduction of the nervous force is different
from that of electricity. The latter force, in order to exert its charac-
teristic eSects, must be transmitted through isolated conductors, so
arranged as to form a complete circuit No such circuit haa ever
been shown to exist in the nervous system ; and the nerves them-
selves, the only tissues capable of conducting the nervous force, are
not particularly good conductors of electricity ; no better, for exam-
ple, than the muscles or the areolar tissue. We know of nothing,
therefore, which should prevent an electric current, passing through
a nerve, &om being dispersed and lost among the adjacent tissues.
This is not the case, however, with the natural stimulus conveyed
by the nervous filament.

Moreover the nerve, in order to conduct its own peculiar force,
mast be in a state of complete integrity. If a ligature be applied
to it, or if it be pinched or lacerated, the muscles to which it is dis-
tributed are paralyzed for all voluntary motion, and yet it transmits
the electric current as readily as before. If the nerve be divided,
and its divided extremities replaced in apposition with each other,
it will still act perfectly well as a conductor of electricity, though
it is needless to say that its natural function is at once destroyed.
The difference in the mode of conduction between the two forces
may be shown in a still more striking manner, as follows. Let the
nerve connected with a frog's leg be divided, and its two extremi-
ties joined to each other by a piece of moist cotton thread. If the
galvanic current be now passed through the detached portion of the
nerve, no contraction will take place ; because the nervous force,
excited in the detached portion, cannot be transmitted through the
cotton thread to the remainder. But if one of the galvanic poles
be applied above, and the other below the point of division, a con-
traction is immediately produced; since the electric current is
readily transmitted by the cotton thread, and excites the lower
portion of the nerve, which is still in connection with the muscles.

The nervous force, therefore, while it has some points of resem-
blance with electricity, presents also certain features of dissimilarity
which are equally important. It must be regarded accordingly as
distinct in its nature from other known physical forces, and as
kltogether peculiar to the nervous tissue in which it originates.

383

THE SPIN'At CORD.

CHAPTER III.

THE SPINAL CORD.

^E have already seen that the spinal cord ia a long ganglion,
covered with longitudinal bundles of nervous filameots, and occu-
pying the cavity of the spinal canal. It sends out nerves which
supply the mnscles and integument of at least nine-tenths of the
whole body, viz^ those of the neck, trunk, and extremities. All
theuo parts of the body are endowed with two very remarkable
properties, the exercise of which depends, directly or indireoUy, I
upon the integrity and activity of the spinal oord, viz^ the power
of sensation and the power of motion. Both these properties are
said to reside in the nervous system, because they are so readily
influenced by its condition, and are so closely connected with its
physiological action. Wo shall therefore commence the stcidy of
the spinal cord with an examination of these two functiona, and of
the situation which they occupy in the nervous system.

SENSATloy.' — The power of sensation, or sensibilitt/, is the power
by which we are enabled to receive imprefeions from external
objects. These impressions are usually of such a nature that we
can derive from them some information in regard to the qualitiea
of external objects and the eHect which they may produce upon
our own systems. Thus, by bringing a foreign body into contact
with the skin, we feel that it is hard or soil, rough or smooth, cold
or warm. We can distinguish the separate impressions produced
by several bodies of a similar character, and we can perceive whe-
ther either one of them, while in contact with the sbin, be at rest
or in motion. This power, which is generally distributed over the
extFernal integument, is dependent on the nervous filaments remi-
fyitig in Its tissue. For if the nerves distributed to any part of the
body be divided, the power of sensation in theoorrespondiag regioD
is immediately lost.

The sensibility, thus distributed over Ehe integument, varies in

SENSATIOW.

888

ita acutcneas in different parts of the body. Thus, llie extrennlies
of the fingers are more Hensitive to external impressions than the
geDcral surface of the limbs and trunk. The surfaces of ilie fniKors
which lie in contact with each other arc more sonaiiive than their
doraal or palmar surfacos. The point of the tongue, the lips, and
the orifices of most of the mucous passages are enduwud with a
sensibility which is more acute than that of the general integument.

If the impression to which these parts are subjected be harsh or
violent in ita character, or of such a nature as to injure ihc texture
of the iDttiguuient or itd nerves, it then produces a sensation of ;^rrL.
U ia essential to notice, however, that the sensation of pain is not
a mere exaggeration of ordinary senaitiva impressions, but is one
of quite a difterent character, which is superadded to the others, or
takes their place altogether. Just in proportion as the contact of a
foreign body becomes painful, our ordinary perceptions of its phy-
sical properties are blunted, and the sense of sufferitig predominates
over ordinary sensibility. Thus if the integument be gently touched
with the blade of a knife we easily feel that it is hani, cold, and
smooth; but if an incision be made with it in the skin, we lose all
distinct perception of these qualities and feel only the suflering
produced by the incision. We perceive, also, the difference in
Temperature between cold and warm substances brought in contact
with the skin, so long as this difference is moderate in degree; but
if the foreign bwly bo excessively cold or excessively hot, we can
no longer appreciate its temperature by the touch, but only its
injurious and destructive effect. Thus the sensation caused by
touching frozen carbonic acid is the same with that producoil by a
red-hot metal. Both substances blister the surface, but their actual
lAmperatures cannot be distinguished.

It is, therefore, a very important fact, in this connection, tbat the
aensibiUty to pain is distinct from the power of orJinari/ smsation. This
dirtinction was first fully established by M. Beau, of Paris, who has
shown conclusively that the sensibility to pain may be diminished
or suspended, while ordinary sensation remains. This is oflen seen
'in patients who are partially under the influence of ether or cblo-
r.roform. The etherization may be carried to such an extent that
the patient may be quite insensible to the pain of a surgical opera-
tion, and yet remain perfectly conscious, and even capable of feeling
the incisions, ligatures, ice., though he does not suffer from tbem.
It not unfrequentty happens, also, when opium has been adminis-
tered for the relief of neuralgia, that the pain is completely abolished

384

THE SPIITJ

by the inflaence of the drug, while the pntient retains completely
his coDSuiousness aad his ordiiiary seiiaibtlity.

In all cases, however, if the iDHueace of the narcotic be pushed
to its extreme, both kinds of sensibility are suspended together, and ■
the patient becomes entirely nneonscious of external impreasioos.

Motion. — Wherever muBOular tissue exists, in any part of the
body, we find the jwwer of raotion, owing to iho contractility of
the muscular fibres. But this power of motion, as we have already
seen, is dependent on the nervous system. The excitement which ■
causes the contraction of the muscles is traosmitted to them by the
nervous ijlamunts; and if the uerves supplying a muscle or a limb —
be divided or seriously injured, these parts am at once paralyzed f
and become incapable of voluntary movement. A nerve which,
when irritated, acta directly npon a muscle, producing contraction,
is said to be txciiahh; and its excitability, acting through the maa-
ole, produces [notion in the part to which it I? distributed. ■

The excitability of various nerves, however, often acts during
life upon other organs, beside the muscles; and the ultimate effect
varies, of course, with the properties of the organ which ia acted
upon. Thus, the nervous excitement transmitted to a muscle prO'
duces contraction, white that transmitted to a gland produoee an
increased secretion, and that conveyed to a vascular surface caasaBl
congestion. In all such iniitances, the effect is produced by an'
influence transmitted by a nerve directly to the organ which isj
called into activity.

But in all the external parts of the body muscular contraction
is the most marked and palpable e£fect produced by ihc direct
influence of nervous excitement. We find, therefore, that, so far
as we have yet examined it, the nervous action shows itself princi*fl
pally in two distinct and definite forraa; first, as si-nsthility, or the
power of sensation, and second, as excilahUity, or the power of pro-
ducing motion.

DisTTNOT Seat or Sensation and Motion in the NEBTotJB'
Ststsh. — Sensation and motion are usually the first functions
which suffer by any injury inflicted on the nervous system. Aa a
general rule, they are both suspended or impaired at the same time,
and in a nearly equal degree. In a fainting fit, an attack of apo-
plexy, concussion ur compression of the brain or spinal cord, or wM
wound of any kind involving the nerves or nervous centres, insen-

DISTINCT SKAT OF SENSATION AND MOTION. 886

sibility and loss of motioa asaally appear aimultaneoasly. It is
d)£5calt, therefore, under ordinary conditions, to trace oat the
separate action of theae two functions, or to ascertain the precise
sitoation occapied by each.

This difficulty, however, may be removed by examiaing sepa-
rately different parts of the nervous eystera. In the instances
mentioned above, the injury which is inflicted is comparatively an
extensive one, apd involves at the same time many adjacent parts.
But instances sometimes occur in which the two functions, sensa*
ttou and motion, are affected independently of each other, owing to
the pecaliar character and situation of the injury inflicted. Sensa-
tion may be impaired without loss of motion, and loss of motion
may occur without injury to sensation. In tic douloureux, for
example, we have an exceedingly painful affection of the sensitive
parts of the face, without any impairment of its power of motion;
and in facial paralysis we often see a complete loss of motion affect-
ing one side of the face, while the sensibility of the part remains
altogether unimpaired.

The above facts first gave rise to the belief that sensation and
motion might occupy distinct parts of the nervous system ; since it
would otherwise be difficult to understand how the two could be
affected independently of each other by anatomical lesions. It has
accordingly been fully established, by the labors of Sir Charles Bell,
Mttller, Fanizza, and Longet, that the two functions do in reality
occupy distinct parts of the nervous system.

If any one of the spinal nerves, in the living animal, afler being
exposed at any part of its course outside the spinal canal, be divided,
ligatured, bruised, or otherwise seriously injured, paralysis of motion
and loss of sensation are immediately produced in that part of the
body to which the nerve is distributed. If, on the other hand, the
same nerve be pricked, galvanized, or otherwise gently irritated, a
painful sensation and convulsive movements are produced in the
same parts. The nerve is therefore said to be both sensitive and
aoeUahk; sensitive, because irritation of its fibres produces a pain-
fnl sensation, and excitable, because the same irritation causes mus*
cular contraction in the parts below.

The result of the experiment, however, will be different if it be
tried upon the parts situated inside the spinal canal, and particularly
upon the anterior and posterior roots of the spinal nerves. If an
irritation be applied, for example, to the anterior root of a spinal
nerve, in the living animal, convulsive movements are produced in
26

the parts below, bat there ia no painful sensation. The antenor"
root BCtiordinglj is said to be excitable, bat not sensitiro. If Uie
posterior root, on tho other luind, be irritated, acute pain is pro-
duced, bill no convulsive movements. The posterior root is there-
fore sensitive, but not excitable. A similar result is obtained by a
complete division of the two roots. Division of the anterior root
produces paralysis of motion^ but no insensibility; division of tho
posterior root produces complete loss of sensibility, bat no mtiscuUr
paralysiA.

We have here, then, a separate localization of sensation and
motion in the nervous system; and it is accordingly easy to under-
stand how one may be impaired without injury to the other, or
how both may be stmnlianeously affected, according to the situation
and extent of the anatomical lesion.

The two root;» of a spinal nerve dififer from each other, further*
more, in their mode of transmitting the nervous impulse. If tho
posterior root be divided (Fig. 135) at a, b, and an irritation applied

Fig. u:>.

I
I

Tk* pdtttrltfr (\x>t )> uep dlvtdod M a, b.

to the separated extremity (n), no effect will be produced; but if
the irritation be applied to the aitaeh^jd extremity (b), a painful
sensation is immediately the resulL The nervous force, therefore,
travels in the posterior root Irom without inward, but cannot pass
from within outward. If the anterior root, on the other hand, bo
divided at e, d, and its attached extremity (d) irritated, no eflect
follows; but if the separated extremity (c) be irritated, convulsive
movements instantly take place. The nervous force, consequently,

SENSIBILITY AND KXClTAfilLlTT IN SPINAL CORD. 887

trarels in the anterior root from within outward, bat cannot pass
from withoDt ioward.

The same thing is troe with regard to the transmission of sensa-
tion and motion in the spinal nerves outside the spinal canal. If
one of these nerves be divided in the living animal, and its attached
extremity irritated, pain is produced, but do convulsive motion; if
the irritation be applied to its separated extremity, muscular con-
tractions follow, but no painful sensation.

There are, therefore, two kinds of 6Iament8 in the spinal nerves,
not distinguishable by the eye, but entirely distinct in their charac-
ter and function, viz., the "sensitive" filaments, or those which
convey sensation, and the "motor" filaments, or those which excite
movement. These filaments are never confounded with each other
in their action, nor can they perform each other's functions. The
sensitive filaments convey the nervous force only in a centripetal,
the motor only in a centrifngal direction. The former preside over
sensation, and Lave nothing to do with motion; the latter preside
over motion, and have nothing to do with sensation. Within the
spinal canal the two kinds of filaments are separated from each
other, constitating the anterior and posterior roots of each spinal
nerve; but externally they are mingled together in a common
tmok. While the anterior and posterior roots, therefore, are ex-
clusively sensitive or exclusively motor, the spinal nerves beyond
the junction of the roots are called mixed nerves, because they con-
tain at the same time motor and sensitive filaments. The mixed
nerves accordingly preside at the same time over the functions of
movement and sensation.

Distinct Sxat or Si£nsibility and Excitability in thb
Spinal Cord. — Various experimenters have demonstrated the fact
that difierent parts of the spinal cord, like the two roots of the
spinal nerves, are separately endowed with sensibility and excita-
bility. The anterior columns of the cord, like the anterior roots of
the spinal nerves, are excitable but not sensitive; the posterior
columns, like the posterior roots of the spinal nerves, are sensitive
but not excitable. Accordingly, when the spinal canal is opened
in the living animal, an irritation applied to the anterior columns
of the cord produces immediately convalsions in the limbs below ;
bat there is no indication of pain. On the other hand, signs of
acate pain become manifest whenever the irritation is applied to
the posterior column ; but no muscular contractions follow, other

888

THK SPIKAL COBD.

than thot^e of a voluntary character. Longet has foand* that if the
gpianl cord be exposed in the lumbar regioo aoil completely divide'l
at that part by transverse section, the application of any irritant to
the anterior surface of the separated portioD produces at once cod*
Tulsions below; while if applied to the posterior colunins behind
the point of division, it has no sensible ctTect whatever. Tbe an*
terior and posterior colamns of tbe cord are accordingly, so fer,
analogous in their propertit^a to the anterior and posterior roots of
tbe spinal nerves, and are plainly composed, to a greater or leas ex-
tent, of a continuation of their filaments,

These filaments, derived from the anterior and posterior roots of
tbe spinal nerves, pass upward through the spinal cord toward the
brain. An irritation upplied to any part of the integument is then
conveyed, along the sensitive filaments of the nerve and its pos-
terior root, to the spinal cord ; then upward, along the longitudinal
fibres of the cord to the brain, where it produces a sensation corres-
ponding in character with the original irritation, A motor im*
pulse, on the other hand, originating in tho brain, is trnnamitted
downward, along the longitudinal fibres of the cord, passes outward
by the anterior root of the spinal nerve, ond, following the motor
filaments of the nerve through its trunk and branches, produces at
lost a muscular contraction at the point of ita final distribution.

Cbossed Action of the Spinal Cord. — As tbe anterior colun»n^
of the cord pass upward to join the medulla oblongata, a decussa-
tioQ takes place between them, aa we have already mentioned in
Chapter I. The fibres of the right anterior column pass over to
the left side of the medulla oblongata, and so upward to the left side
of the brain ; while the fibres of the left anterior column pass over
to the right side of tbe medulla oblongata, and so upward to the right
side of the brain. This decussation may be readily shown (aa in
Fig. 130) by gently separating the anterior columns from each other,
at the lower extremity of the medulla oblongata, where the decus-
sating bundles may be seen crossing obliquely from side to side, at
the bottom of the anterior median fissure. Below this point, the
anterior columns remain distinct from each other on each side, and
do not communicate by any further decussation.

If the anterior columns of the spinal cord, therefore, be wounded
at any point in the cervical, dorsal, or lumbar region, a pamlysis

I
i

I
I

* Traiie de Fh7Bioto«l», to), li. part 2, p. 8.

# OBOSSKD ACTIOS OF THE SPINAL CORD. 889

of ToIoDtary motion is produced in the Itmbs below, on the same
dde with the injury. Bat if a similar lesion occur in the brain, the
paralysis which results is on the opposite side of the body. Thus
it has long been known that an abscess or an apoplectio hemorrhage
on the right side of the brain will produce paralysis of the left side
of the body; and injury of the left side of the brain will be fol*
lowed by paralysis of the right side of the body.

The spinal oord has also a crossed action in transmitting sensi-
tive as well as motor impulses. It has been recently demonstrated
by Dr. Brown-S^uard,' that the crossing of the sensitive fibres in
the spinal oord does not take place, like that of the motor fibres,
at its upper portion only, but throughout its entire length ; so that
the sensitive fibres of the right spinal nerves, very soon after their
entrance into the cord, pass over to the left side, and those of the
left spinal nerves pass over to the right side. For if one lateral
half of the spinal cord of a dog be divided in the dorsal region,
the power of sensation remains upon the corresponding side of the
body, but is lost upon the opposite side. It has been shown, fur-
thermore, by the same observer,* that the sensitive fibres of the
spinal nerves when they first enter the cord join the posterior
oolumns, which are everywhere extremely sensitive; but that they
very soon leave the posterior columns, and, passing through the
oeotral parts of the cord, run upward to the opposite side of the
brain. If the posterior columns, accordingly, be alone divided at
any part of the spinal cord, sensibility is not destroyed in all the
nerves behind the seat of injury, but only in those which enter the
cord at the point of section; since the posterior columns consist
of different nervous filaments, joining them constantly on one side
from below, and leaving them on the other to pass upward toward
the brain.

The spinal cord has therefore a crossed action, both for sensation
and motion; but the crossing of the motor filaments occurs only at
the medulla oblongata, while that of the sensitive filaments takes
place throughout the entire length of the cord itself.

There are certiun important facts which still remain to be noticed,
regarding the mode of action of the spinal cord and its nerves.
They are as follows: —

■ Ezperimeotal BMMrohes appllad to PhriiologT- and rathology. New York,

ias3.

■ lUm<rin lor U PhTiiologia de la Ho«lle iplaiin ; OaietU M6dfc«l« de Paria,
1855.

SDO

THB 8Pi;f At. CORD.

1. An irrilah'on apjAitd to a spinal nerve at the middle of itt ci»ir9€
produces the some effect as if it trat-ersed {($ entire tenglh. Thus, if the
Bciaiic or median nerve be irritated at any part of its course, con-
traction is produced in the mnscles to which these nerves are dis-
tributed, just as if the impulse had originated as usual from the
brain. Thia fact depends upon the character of the nervous fila-
ments, as simple condactors. Wherever the impulse may originate,
the final effect ia manifested only at the termination of the nerve.
As the impulse in the motor nerves travels always in an outward
direction, the effect is always produced at the muscular termination
of the filaments, no matter how smiill or how large a portion of
their length may have been engaged in transmitting the niimulua.

If the irritation, again, be applied to a sensitive nerve in the
middle of its course, the painful sensation is felt, not at the point
of the nerve directly irritated, but in that portion of the integument
to which its filaments are distributed. Thus, if the ulnar nervo be
accidentally struck at the point where it lies behind the inner con-
dyle of the horaerus, a sensation of tingling and numbness is pro-
duced in the last two fingers of the corresponding hand. It is
comroot) to hear patients who have suffered amputation complain nf
painful sensations in the amputated limb, for weeks or months, anil
sometimes even for years after the operation. They assert that
they can feel the separated parts as distinctly ns if they were stiU
attached to the body. This sensation, which is a real one and not
fictitious, is owing to some irritation operating upon the divided
extremities of the nerves in the cicatrized wound. Such nn irrita-
tion, conveyed to the brain by the sensitive fibres, will produce
precisely the same sensation us if the amputated parts were stiU
present, and the irritation actually applied to them.

It is on this account also that division of the trifacial nerve is
not always effectual in the core of tic doalooreux. If the cause of
the difficulty be acatcd upon the trunk of the nerve, between its
point of emergence from the bones and its origin in the brain, it ts
evident that division of the nerve upon the face will be of no
avail; since the cause of irritation will still exist behind the point
of section, and the same painful sensations will still be produced in
the brain.

2. The irritahilily of the motor filaments disappears from within out-
ward^ thai of the sensitive JilamentB fmrn without inward. Immedi-
ately after the separation of the frog's leg from the body, irritation
of the nerve at any point produces muscular contraotion in the

INDEPKNDENCE OP ITERVOUB FILAUENTS. 891

limb below. As time elapses, however, and the irritability of the
nerre diminishes, the galvanic current, in order to produce con-
traction, most be applied at a point nearer its termination. Subse*
qoently, the irritabilitj of the nerve is entirely lost in its upper
portions, bat is retained in the parts situated lower down, from
which it also, in tarn, afterward disappears; receding in this man-
ner forther and farther toward the terminal distribution of the
nerve, where it finally disappears altogether.

On the other hand, sensibility disappears, at the time of death,
first in the extremities. From them the numbness gradually creeps
upward, invading successively the middle and upper portions of the
limbs;, and the more distant portions of the trunk. The central
parts are the last to become insensible.

S. Eadi nervous filament acts independently of the rest throughout ita
entire length, and doea not eommunioate ita irritation to thoae which are
HI proximity with it. It is evident that this is true with regard to
the nerves of sensation, from the fact that if the integument be
touched with the point of a needle, the sensation is referred to that
spot alone. Since the nervous filaments coming from it and the
adjacent parts are all bound together in parallel bundles, to form
the trank of the nerve, if any irritation were communicated from
one sensitive filament to another, the sensation produced would be
indefinite and diffused, whereas it is really confined to the spot irri-
tated. If a frog's leg. furthermore, be prepared, with the sciatic
nerve attached, a few of the fibres separated laterally from the
nervous trunk for a portion of its length, and the poles of a galvanic
battery applied to the separated portion, the contractions which
follow in the leg will not be general, but will be confined to those
moBcles in which the galvanized nervous fibres especially have
their distribution. There are also various instances, in the body,
of antagonistic muscles, which must act independently of each
other, bat which are supplied with nerves from a common trunk.
The superior and inferior straight muscles of the eyeball, for
example, are both supplied by the motor oculi communis nerve.
Extensor and flexor muscles, as, for example, those of the fingers,
are often supplied by the same nerve, and yet act alternately with-
out mutual interference. It is easy to see that if this were not the
ease, confusion would constantly arise, both in the perception of
sensations, and in the execution of movements.

4. There are certain sensations which are excited simultaneously
by the same causes, and which are termed associated eensaliona ; and

S92

THB 8PIKAL OOBDT

there are also certain movements which take place simuItaQeouslj,
and are called a$30cialed motKments, Id tbe fonuer iastance, one of
the asaocintod sen^Lions is called up iinmodiatel^ upon the percep-
tion of the other, without requiring any direct impulse of its own. ■
Thus, tickling the sole^ of the feet produces a peculiar sensation
at tbe epigustrium. Nausea is oecasioned by cerLain disagreeable
odors, or by rapid rotation of the body, so that the landscape seems
to turn round. A striking example of associated movements, on
the other hand, may bo found in tbe action of the muscles of the
eyeball. Tbe eyeballs always accompany each other in their lateral
motions, turning to the right or the lefl aide simultaneously. U is
evident, however, that in producing this correspondence of motion,
the lel^ internal rectus muscle must contract and relax together
with the right external ; while a similar harmony of action must
exist betweeu the right internal and the left external. The explana-
tion of such singular correspuudencus catinot be found in the auato-
mical arrangemeut of the muscles themselves, nor in that of the ■
nervoua filaments by which they are directly supplied, but must be
looked for id some special endowment of the uervouii centres from
which they originate.

K^'LUX Action op thb Spinal Cokd. — The spinal cord, aa wa
have thus far examined it, may be regarded simply as a great nerve;
that is, as a buudle of motor and sensitive filaments, connecting
the muscles and integumouL below with the brain above, and
assisting, in this capacity, in the production of conscious sensation
and voluntary motion. Beside its nervous filaments, however, it<
contains also a largt) quantity of gray matter, and is, therefore^
itself a ganglionic centre, and capable of independent action as
such. We shall now proceed to study it in its seoond capacity, as
a distinct nervous centre.

If a frog bo deuapilated, and the body allowed to remain at rest
for a few moments, so as to recover from the depressing effects of
shock upon the nervous system, it will be found tliat, although sen*
sation and consciousness are destroyed, the power of motion siill
remaiiis. If the skin of one of tbe feet be irritated by pinching it
with a pair of forceps, tbe leg is immediately drawn up toward the
body, as if to escape the cause of irritation. If the irritation applied
to tbe foot be of slight intensity, the corresponding leg only will
move; but if it bo more severe in character, motions will ofkeo be
produced in the posterior extremity of the opposite side, and even

BSFLEX ACTIOy OF THB SPINAL COBD.

893

in the two fore legft, at the fiamc time. These motions, it is import-
ant to observe, are never spontaneous. The decapitated frog remains
perfectly qaiescent if left to bimseir. It is only when some cause
of irrttatioD is applied externally, that movements occur as above
described.

It will be seen that the character of these phenomena indicates
the active operation of some part of the nervous system, and par-
licalarly of some ganglionic centre. The irriUition is applied to
the skin of the foot, and the muscles of tlio leg c^mtruct in conse-
quence; shovring evidently the intermediate action of a nervous
oonnecuon between the two.

The effect in question is due to the activity of the spinal cord,
operating aa a nervous centre. In ordur that the movements may
take place as above, it is essential that both the integument and the
mascles should be in communication with the spinal cord by nerv-
ous filaments, and that the cord itself be in a state of integrity. If
the sciatic nerve be divided in the upper pari of the thigh, irritation
of the skin below is no longer followed by any muscular oontrao-
tion. If eitlier the anterior or posterior roots of the nerve be
divided, the same want of action results; and finally, if, the nerve
aod its roots remaining entire, the spinal cord itself be broken up
by a needle introduced into the spinal
canal, the integument may then be
irritated or mutilated to any extent,
without exciting ihe least muscular
contraction. It is evident, therefore,
that the spinal oord acts, in this case,
04 a oervoQs centre, through which
the irritation applied to the skin is
oommunicated to the muscles. The
irritation first passes upward, aa shown
in the accompanying diagram (Fig.
136), along the sensitive fibres of the
posterior root (o) to ihe gray matter
of the cord, and is then reflectetl back,
ilong the motor fibres of the anterior
root (6), until it finally reaches the

muscles, and produces a contraction. This action is known, accord*
iogly, as the rtjiex action of the tj>miil cord.

It will be remembered that this reflex action of the cord Is not
ftocompanied by volition, nor even by any conscioa-i sensation.

prft. I3<i.

DUfmm »r firiSlLCoBft IK VSB-
TlrAt. liic-Tiav, ahiivlBg rttint aMlDii.

Mrtur tvut of tplaal nvrra.

394

THE SPISAL COED.

The function of the spinal cord as a, nervoas centre is simply
convert nn impression, received from tlicHkin, into a motor impul
which is sent out again to the muscles. There is absolutely no
fartlier Action than this; no exercise of will, consciousTiesa, or judg*fl
ment. This action will therefore t;ike place perfectly well after
the brain has been removed, and nfU;r the entire sympathetic Bf&>
tern has also l>een taken away, provided only that the spinal cord
and its nerves remain in a state of integrity. fl

The existence of this reflex action after death is accordingly an ™
evidence of the continued activity of the spinal cord, just aa con-
tractility is an evidence of the activity of the maacles, and irrita-
bility of that of the nerves. Like the two last-mentioned pro[>crttea,
also, it continues for a longer time after death in cold-blooded than
in warm-blooded animals. It is for this reason that frogs and other
reptiles are the most useful subjects for the study of these pheno-
mena, aa for that of most others belonging to the nervous system.

The irritability of the spinal cord, as manifested by tea reflex
action, may be very much exaggerated by certain diseases, and by
the operation of poisonous substances. Tetanus and poisoning by
strychnine buth act in this way, by heightening the irritability of
the spinal cord, and cautiing it to produce convulsive movements
on the application of external stimulus. It has been observed that
the convulsions in tetanus are rarely, if ever, spontaneous, but that
they always require to be excited by some external cause, snch as
the accidental movement of the bedclothes, the shutting of a door,
or the sudden passAge of a current of air. Such slight canses of
irritation, which would be entirely inadequate to excite involuntary
movements in the healthy corvdition, act upon the spinal cord, when
its irritability is heightened by disease, in such a manner as to pro*^
dace violent convulsions. H

Similar appcamncca are to be aeen in animals poisoned by atrycb-
nine. This substance acts upon tlio spinal cord and increases ila
irritability, without materially affecting the functions of the brain.
Ita effects will show themselves, consequently, without essential
modification, after the head has been removed. If a decapitated
frog be poisonctl with a moderate dose of .strychnine, the body and
limbs will remain quiescent so long as there is no external source
of excitement; but the limbs are at once thrown into convulsions
by th'e slightest irrilaiion iippliud to the skin, as, for example, the
contact of a hair or a feather, or even the jarring of the table on
which the animal ia placed. That the convulsions in ca^es of

BKFLKX ACTION OF THB SPINAL OOBD. 895

poisoning hy Btrychnine are always of a reflex character, and nerer
spontaneoaa, is shown by the roUowing fact first noticed by Ber-
nard/ riz^ that if a frog be poisoned after division of the posterior
roots of all the spinal nerves, while the anterior roots are left un-
touched, death takes place as usual, but is not preceded by any con-
Tulsioos. In this instance the convulsions are absent simply
because, owing to the division of the posterior roots, external irri-
tations cannot be communicated to the cord.

The reflex action, above described, may be seen very distinctly
in the human subject, in certain cases of disease of the spinal cord.
If the upper portion of the cord be disintegrated by inflammatory
softening, so that its middle and lower portions lose their natural
oonnection with the brain, paralysis of volantary motion and loss of
sensation ensue in all parts of the body below the seat of the ana-
tomical lesion. Under these conditions, the patient is incapable of
making any muscular exertion in the paralyzed parts, and is uncon-
actons of any injury done to the integument in the same region.
Notwithstanding this, if the soles of the feet be gently irritated
with a feather, or with the point of a needle, a convulsive twitch-
ing of the toes will often take place, and even retractile movements
of the leg and thigh, altogether without the patient's knowledge.
Sneh movements may frequently be excited by simply allowing
the oool air to come suddenly in oontact with the lower extremities.
We hare repeatedly witnessed these phenomena, in a case of dis-
ease of the spinal cord where the paralysis and insensibility of the
lower extremities were complete. M&ny other similar instances
are reported by various authors.

The existence of this reflex action of the cord has enabled the
physiologist to ascertain several other important facts concerning
the mode of operation of the nervous system. M. Bernard has
demonstrated,' by a series of extremely ingenious experiments on
the action of poisonous substances, 1st, that the irritability of the
mnscles may be destroyed, while that of the nerves remains unal-
tered; and 2d, that the motor and sensitive nervous filaments may
he paralyzed independently of each other. The above facts are
shown by the three following experiments: —

1. In a living frog (Fig. 137), the sciatic nerve (i\0 is exposed in

' Le^oiM anr In effets dM SnbtUnoM toxiqnes ot mMicam«nt«a9«s, Parii, 1867,
^357.
' liM., CUpi. 23 ud 21.

see

THB 8PINJIL CORD.

the back part of tho thigh, a^^er which a ligature ia passei] u
neath ilaml ilrnwo tight around the hone and the remainitig soft'
parta. In this way thu circulation is entirely cut off from the limb
(rf), which remains in connection with the trunk only by means of
the sciatic nerve. A solution of sulphocyanide of potassium is then

introduced beneath the skin
^t' ^^' of the back, at /, In sufficient

quantity to produce its speci*
fie effect. The poison ia then
absorbed, aud ia carried by
the circulation throughout the
trunk and the three oxtrtinii|
ticii a, b, c; while it is prM
vented from entering the limb
d, by the ligature which hM
been placed about the thigM
Sulphocyanide of potassium
produces paralysis, as we have
provtouftly mentioned, by a
ing directly upon the raus
lar tissue. Accordingly, a
vanicdischargc passed throu,
the limbs a, h, and c, produ<
no contraction in them, wbi'
the same stimulus, applied to
d, Is followed by a strong and
healthy reaction. But at the
moment when the irritation
is applied to the poisonet
limbs 11, b, and e; though
visible eft'ect Is produced
them, an active movem
takes plaoo in the heol^
limb, d. This can only
owing to a reflex action of the spinal oord, originating in the in
gument of a, b, and c, and transmitted, by sensitive and motor til
montA, through the cord, to d While the mttecles 0/ Oie poiaom
limh, t?teri/ore, have been dtrecthj paralyzed^ the nervee 0/ the sa\
parte havn r^aintd their irritability.

2. If a frog be poisoned with woorara by simply placing t
poison under the skin, no reflex action uf the spinul cord can

BBFLBX ACTIOy OF THE SPINAL CORD. 807

demonstrated after death. We bare already shown, from experi-
ments detailed in Chapter II., that this sabstance destroys the irrita-
bility of the motor Derves, without affecting that of the muscles. In
the above instance, therefore, where the reflex action is abolished, its
kwa may be owing to a paralysis of both motor and sensitive fila-
ments, or to that of the motor filaments alone. The following experi-
ment, however, shows that the motor filaments are the only ones
affected. If a frog be prepared as in Fig. 187, and poisoned by the
introdaction of woorara at /, when the limb d is irritated its own
muscles react, while no movement takes place in a, 6, or c ; but if
the irritation be applied to a, 6, or c, reflex movements are imme-
diately prodaoed in dL In the poiaoned limbs, therf/ore, while the
molor nerves have been paralyzed^ the sensitive filaments have retained
Iheir irritqhilUy.

8, If a frog be poisoned with strychnine, introduced underneath
the skin in sufficient quantity, death takes place after general oon-
TulsioDs, which are due, as we have seen above, to an unnatural
excitability of the reflex action. This is followed, however, by a
paralysis of sensibility, so that after death no reflex movements
can be produced by irritating the skin or even the posterior roots
of the spinal nerves. But if the anterior roots, or the motor nerves
themselves be galvanized, contractions immediately take place in
the corresponding muscles. In this case, there/ore^ the sensitive fila-
Wienie have been paralyzed, while the motor filaments and the muscles
have retained their irritability.

We now come to investigate the reflex action of the spinal cord,
as it takes place in a healthy condition during life. This action
readily escapes notice, unless our attention be particularly directed
to it, because the sensations which we are constantly receiving, and
the many voluntary movements which are continually executed,
lerve naturally to mask those nervous phenomena which take place
without our immediate knowledge, and over which we exert no
Toluntary control. Such phenomena, however, do constantly take
place, and are of extreme physiological importance. If the surface
of the skin, for example, be at any time unexpectedly brought in
contact with a heated body, the injured part is often withdrawn by
a rapid and convulsive movement, long before we feel the pain, or
even fairly understand the cause of the involuntary act. If the
body by any accident suddenly and unexpectedly loses its balance,
the limbs are thrown into a position calculated to protect the ex-
posed parts, and to break the fall, by a similar involuntary and in-

898

THE SPtXAL OOBD.

sUntaneoua movcmetit The brain does not act in these cues, For
there is no intentional character in the movement^ nor even any
complete coQaciousness of its object Kverything indicata tluit u
ii the immediate result of a simple reflex action of the spiokl oord.

The cord exerts also an important and constant influence tipon
the spkmclcr muscUt. The sphincter ani is habitually in a state of
contraction, so that the contents of the intestine are not allowed to
escape. VVhen any external irritation is applied to the iaiis,or
whenever the feces present iliemselvcs internally, the sphincter
contracts involuntarily, and the discharge of the feces ts preveoted.
This habitual closure uf the sphincter depends on the reflex idiot
of the spinal cord. It is entirely an involuntary act, and wiUcos-
tinue, in the healthy condition, during p'rofoand sleep, ascomplde
and efTiciutit as in the waking state.

When the rectum, however, has become filled by the accu
tion uf feces from above, the nervous action changes. Tfaeo
impression produced on the mucous membrane of the dtsleadei
rectum, conveyed to the spinal cord, causes at the same Umei*
laxatioD of the sphincter and contraction of the rectum itaelf: m
that a discharge of the feces consequently takes place.

Now all theae actions are to some extent under the cootrolof
sensation and volition. The distended state of the rectum is osuaHf
accom|>anicd by a distinct sensation, and the resistaooe of ti»
sphincter may be voLuntarily prolonged for a certain period, just u
the respiratory movements, wbicli are usually involunuiry, ouij U
intentionatly hastened or relan.]ed, or even temporarily saspeaiM
But this voluntary power over the sphincter and the ractua a
limited. After a time the involuntary impulse, growing n»«
urgent with the increased distension of the rectum, becomes im
sistible; and the di^K:ha^ge finally takes place by the simple nSei
action of the spinal cord.

If the f>pinal cord be injured in its middle or upper portions, tlK
sensibility and voluntary action of the sphincter are lost, because lU
connection with the brain has been destroyed. The evacoalMe
then takes place at once, by the ordinary mechanism, as sooo u
the rectum is filled, but without any knowledge on the part of Ur
patient. The discbarges are then said to be "iovoluotary and on-
conscious."

If the irritability of the cord, on the other hand, be exaggeratst
by disease, while its connection with the brain remains entire, the
distcn.-4iiHi of the rectum a announced by the usual aensation, bot

BEFLIX ACTION OF THI SPINAL CORD. 899

die refiez impalse to eracuatioa is so urgent that it cannot be
coDtrolled by the will, and the patient is compelled to allow it to
take place at onoe. The discbarges are then said to be simply
"iovolontary."

Finally, if the substance of the spinal cord be extensively de-
stroyed by accident or disease, the sphincter is permanently relaxed.
The feces are then evacaated almost continnoasly, withoat any
knowledge or control on the part of the patient as fast as they
descend into the rectum from the upper portions of the intestine.

Injury of the spinal cord produces a somewhat different effect on
the urinary bladder. Its muscular fibres are directly paralyzed ;
and the organ, being partially protected by elastic fibres, both at
its own orifice and along the urethra, becomes gradually distended
by urine from the kidneys. The urine then overcomes the elas-
ticity of the protecting fibres, by simple force of accumulatiou, and
afterward dribbles away as fast as it is excreted by the kidneys.
Paralysis of the bladder, therefore, first causes a permanent disten-
fooa of the organ, which is ailerward followed by a continuous,
passive, and incomplete discharge of its contents.

Injury of the spinal cord produces also an important, though
probably an indirect effect on nutrition, secretion, animal heat, &c.,
in the paralyzed parts. Diseases of the cord which result in its
softening or disintegration, are notoriously accompanied by consti-
pation, often of an extremely obstinate character. In complete
l)araplegia, also, the lower extremities become emaciated. The
texture and consisteocy of the muscles are altered, and the animal
temperature is considerably reduced. All such disturbances of
nutrition, however, which almost invariably follow upon local para-
lysis, are no doubt immediately owing to the inactive condition uf
the muscles ; a condition which naturally induces debility of the
circulation, and consequently of all those functions which are de-
pendent upon it.

It is less easy to explain the connection between injury of the
spinal cord and inflammation of the urinary passages. It is, bow-
ever, a matter of common observation among pathologists, that
injury or disease of the cord, particularly in the dorsal and upper
lamb«r regions, is soon followed by catarrhal indammution of the
urinary passages. This gives rise to an abundant production of
altered mucus, which in its turn, by causing an alkaline fermeuta-
tion of the urine contained in the bladder, converts it into an irri-

400 THK SFIKAL CORD.

tat'mg and ammoniacal liquid, which reacts upon the mncous mem-
brane and aggravates the previous inflammation.

We find, therefore, that the spina] cord, in its character of a
nervous centre, exerts a general protective action over the wbole
body. It presides over the involuntary movements of the limbs
and trunk ; it regulates the action of the sphincters, the rectum,
and the bladder; while at the same time it exerts an indirect influ-
ence on the nutritive changes in those parts which it supplies with
nerves.

THE BBAIN. 401

CHAPTER IV.

THE BRAIN.

Bt the brain, or meepkaJon, as it is sometimes called, we mean all
that portion of the nerroas system which is situated within the
cavity of the cranium. It consists, as we have already shown, of
a series of di&rent ganglia, connected with each other by transverse
and longitudinal commissures.

Since we have found the functions of sensation and motion, or
sensibility and excitability, so distinctly separated in the spinal
cord, we should expect to find the same distinction in the interior
of the brain. These two properties have indeed been found to be
distinct from each other, so far as they exist at all, in the encephalic
mass; but it is a very remarkable fact that 'they are both confined
to very small portions of the brain, in comparison with its entire
bulk. According to the investigations of Longet, neither the
olfactory ganglia, the corpora striata, the optic thalami, the tuber-
cula quadrigemina, nor the white or gray substance of the cerebrum
or the cerebellum, are in the least degree excitable. Mechanical
irritation of these parts does not produce the slightest convulsive
movement in the muscles below. The application of caustic liquids
and the passage of galvanic currents are equally without effect.
The only portions of the brain in which irritation is followed by
convulsive movements are the anterior surface of the medulla ob-
longata, the tuber annulare, and the lower partof the crura cerebri ;
that is, the lower and ceutral parts of the brain, containing continu-
ations of the anterior columns of the cord. On the other hand,
neither the olfactory ganglia, the corpora striata, the tubercula
quadrigemina nor the white or gray substance of the cerebrum or
cerebellum, give rise, on being irritated, to any painful sensation.
The only sensitive parts are the posterior surface of the medulla
oblongata, the restiform bodies, the processus e cerebello ad testes,
and the upper part of the crura cerebri; that is, those portions of
the base of the brain which contain prolongations of the posterior
columns of the cord.
26

40S

TBK nBAlK.

Tbo moat central portions of the nervoaa system, therefore, aa<1
particularly tlie gray matter, are destitute of butb excitability an*!
sensibility. It is only tlioso portiuDa which serve to conduct son-
SQtiona and nervoua impulses that caa be excited by mechanical
irrltaiion ; not the ganglionic centres themselves, which receive and j
originate the nervous impressions.

We shall now study in succession the difTereot ganglia of which
the brain is composed.

Olfactory Ganglia. — These gnnglia, which in some of the
lower animals are very lai^e, corresponding in size with the ex-
tent of the olfactory membrane and the acutenesa of the sense of
smell, are very small in the human subject. They are situated ou
the cribriform plate of the ethmoid bone, on each side of the criMa
galli, just beneath the anterior lobes of the cerebrum. They send
their nerves through the numerous perforations which exist in the _
ethmoid bone at this part, and are connected with the base of thefl
bruin by two longitudinal commissures. The olfactory ganglia
with their commissures are sometimes spoken of as the "olfactory
nerves." They are not nerves, however, but ganglia, since they are
mostly composed of gniy matter; and the term ''olfactory nerves''
can be properly applied only to the filaments which originate from
them, and which are afterward spread out id ihe substance of the
olfactory membrane.

It has been found dilTicult to determine the function of tfaese^
ganglia by direct experiment on the lower animals. They may be
destroyed by means of a strong nee(.lle introduced through the bones
of the cranium ; but the signs of the presence or absence of the
senae of smell, after such an operation, arc too indefinite to allow us
to draw from them a decided conclusion. The anatomical distribo-
tioD of their nerves, however, and the evident correspondence which
exisld, in difierent species of auimul.-*, between their degree of de-
velopment and that of the external olfactory organs, leaves no doubt
as to their true function. They are the ganglia of the special een&u
of smell, and arc not connected, in any appreciable degree, with
ordinary sensibility, uor with the production of voluntary move-
ments.

Optic Tiialami. — These bodies are not, as their name would ^
imply, the ganglia of vision. Longet has found that the power of fl
sight and the sensibility of the pupil both remain, in birds, after

CORPORA STRIATA.— HCUISPHERB8. 408

the optic thalami have beeo tboroaghly disorganized; and that arti-
ficial irritation of the same ganglia has no e^t in producing
either oontractton or dilatation of the papil. The optic thalami,
however, aocording to the same observer, have a peculiar crossed
action upon the voluntary movements. If both hemispheres and
both optic thalami be removed in the rabbit, the animal is still
capable of standing and of using hia limbs in progression. But if
the right optic thalamus alone be removed, the animal fklls at once
upon his left side; and if the left thalamus be destroyed, a similar
debility is manifest on the right side of the body. In these in-
stances there is no absolute paralysis of the side upon which the
animal, falls, bat rather a simple want of balance between the two
opposite sides. The exact mechanism of this peculiar functional
disturbance is not well understood; and but little light has yet
been thrown, either by direct experiment or by the facts of compa-
rative anatomy, on the real function of the optio thalami.

GoBPORA Striata. — The function of these ganglia is equally
uncertain with that of the preceding. They are traversed, as we
have already seen, by fibres coming from the anterior columns of
the oord; and they are connected, by the continuation of these
fibres, with the gray substance of the hemispheres. They have,
therefore, in all probability, like the optic thalami, some connection
with sensation and volition; but the precise nature of this connec-
tion is at present altogether unknown.

Hkmisphebrs. — The hemispheres, or the cerebral ganglia, con-
stitute in the human subject about nine-tenths of the whole mass
of the brain. Throughoat their whole extent they are entirely
destitute, as we have already mentioned, of both sensibility and ex-
citability. Both the white and gray substance may be wounded,
burned, lacerated, crushed, or galvanized in the living animal, with-
out exciting any convulsive movement or any apparent sensation.
Iq the human subject a similar insensibility has been observed
when the substance of the hemispheres has been exposed by acci-
dental violence, or in the operation of trephining.

Very severe mechanical injuries may also be inflicted upon the
hemispheres, even in the human subject, without producing any
directly fatal result One of the most remarkable instances of this
fact is a case reported by Dr. William Detmold, of New York,' in

' Am. JoDrn. of Mud. Scl., Jannarjr, 1S50.

104

TBE BRAIN.

vrbich an nbscess in the anterior lobe of the brain was opened by an
incision passing through the cerebral substance, nut only without
any immediate bad eOect, but with great temporary reliel' to the
patient. This was the caae of a laborer who was struck on the left
side of the forehead by a piece of fulling timber, which produced a
compound fracture of the skull at this part One or two pieces of
boue afterward became separated and were removed, and the wound
aubsequently healed. Nine weeks after the accident, however,
headache and drowsiness cnme on ; and the latter symptom, becom-
ing rapidly aggravated, soon terminated in complete stupor. At
this lime, the existence of an abscess being suspected, the cicatrix,
together with the adherent portion of the dura mater, was dissected
away, several pieces of fractured bone removed, and the surface of
the brain exposed. A knife was then passed into the cerebral sub-
stance, making a wound one inch in length and half an inch in
depth, when the abscess was reached and over two ounces of pus
discharged. The patient immediately aroused from his comatose
condition, so that he was able to speak; and in a few days reco-
vered, to a very considerable extent, his cheerfulness, inielligenoe,
and appetite. Subsequently, however, the collectiou of pus re-
turned, accompanied by a renewal of the previous symptoms; and
the patient finally died at the end of seven weeks from the lime of
opening the abscess.

Another and still more striking instance of recovery from severe
injury of the brain is reported by Prof. H. J. Bigelow in the
American Jounml of Afciical Sciences for July, 1S50. In this case, a
pointed iron bar, thr,ee feet nod a half tn length, and one inch and a
quarter in diameter, was driven through the patient's head by the
premature blasting of a rock. The bar entered the left side of the
face, just in froat of the angle of the jaw, and passed obliquely
upward, inside tlie zygomatic arch and through the anterior port
of the cranial cavity, emerging from the top of the fronWl bone on
the median line, just in front of the point of union of the coronal
and sagittal sutures. The patient was at first stuuued, but soon
recovered himself so far as to be able to converse intelligently, rode
home in a common cart, and with a little aaaistance walked upstairs
to his room. He became delirious within two days after the aooi>
dent, and subsequently remained partly delirious and partly coma-
toae for about three weeks, lie then began to improve, and al the
end of rather more than two months from the date of the injury,
was able to walk about. At the end of sixteen months he was in

HEUISPHERES.

AOl

perfect health, with the wounds healed, and with the mental and
bodily functions entirely unimpaired, except that sight wns perma-
nently lost in the nyQ of the injured side.

The hemispheres, furthermore, are not the seat of sensation or of
volition, nor are they immediately essential to the continuance of
life. In quadrupedn, the complete removal of the hemispheres is
Attended with so ranch hemorrhage that the operation is generally
fatal from this cause within a few minutes. Id birds, however, it
may be performed without any immediate danger to life. Longet
has removed tlie hemispheres in pigeons and fowls, and has kept
these animals afterward for several days, with most of the organic
functions unimpaired. We have frequently performed the same

cperiment upon pigeons, with a similarly favorable result.

The effect of this mutilation is simply to plunge the animal into
a Btata of profound stupor, in which he is almost entirely inatten-
tive to surrounding objects. The bird remains sitting motionless
upon his perch, or standing upon the ground, with the eyes dosed,
and the head sunk between the shoulders. (Fig. 138.) The plu-

Fig. 138. ,

>% A

lis smooth and glossy, but ia uniformly expanded, by a kind
Erection of the fonihera, bo that the bmly appears somewhat
puffed out, and larger than natural. Occasionally the bird opens
his eyes with a vacant stare, stretches his neck, perhaps shakes his
bill once or twice, or smooths down the feathers upon his shoulders,
and then relapses into his former apathetic condition. This state
of immobility, however, is not accompanied by iho loss of sight, of
hearing, or of ordinary sensibility. All these functions remain, as

THE BRAiy.

well as tliat of voluntary motion. If a pistol he discharged beliind
tho hack of the animfti, he at once opens his ejes, roovea Iiia head
half round, and gives evident aignsof having heard the report; but
he immediately becomes quiet again, and paja no farther attention
to it. Sight is also rL'tainetl, since the bin! will aometimcs fix its
eye on a particular object, and watch it for several seconds together.
^Longet hae even found that by moving a lighted candle before the
anicnal's eyes in a dark place, the head of the bird will often follow
the movements of the candle from side to side or in a circle, showing
that tho impression of light '\a actually perceived by the sensoriuni.
Ordinary sensnlion also remains, after removal of the hemispheres,
together with voluntary motion. If the foot be pinched with k
pair of foTxitipa, tlio bird becomes partially aroused, moves uneasily
once or twice from side to side, and is evidently annoyed at the
irritation.

The animal is Atill capable, therefore, afWr removal of the hemi-
spheres, of receiving sensations from external objects. But these
sensations appear to make upon him no lasting impression. He is
incapable of connecting with his perceptions any distinct succession
of ideas. He hears, for example, the report of a pistol, but he is not
alarmed by it; for the sound, though distinctly enough fwrceived,
does not suggest any idea of danger or injury. There is accord-
ingly no power of forming mental aasocialiona, nor of perceiving
the relation between external objects. The memory, more particu-
larly, is altogether destroyed, and the recollection of sensations is
not retained from one moment to another. The limbs and muscles
ore still under the control of the will; but the will itself is inactive,
because apparently it lacks \is usual mental stimulus and direction.
The powers which have been lost, therefore, by destruction of tho
cerebral hemispheres, are altogether pf a mental or intellectual
character; that is, the power of comparing with each other difterent
ideas, and of perceiving the proper relation between them.

The same result is well known to follow, in the human subject,
from injury or disease of these parts. A disturbance of the mental
powers has long been recognized as the ordinary con.sequence of
Ic-iions of tho brain. In cases of impending apoplexy, for example,
or of softening of the cerebral substance, among the earliest and
most constant phenomena la a loss or impairment of the memory.
The patient forgets the names of particular objects or of |)articular
persons; or he is unable to calculate numbers with his usual facility.
Uis mental derangement is ottcn shown in the undue estimate which '

HSUISPHSBES. 407

he forms of passing events. He is no longer able to appreciate the
trae relation between different objects and different phenomena.
Thaa, he will show an exaggerated degree of solicitude about a
tririal occnrrence, and will pay no attention to other matters of
real importance. As the difficulty increases, he becomes careless
of the directions and advice of bis attendants, and must be watched
and managed like a child or an imbecile. After a certain period,
he no longer appreciates the lapse of time, and even loses the dis-
tinction between day and night. Finally, when the injury to the
hemispheres is complete, the senses may still remain active and
impressible, while the patient is completely deprived of intelligence,
memory, and judgment.

If we examine the comparative development of the hemispheres
in different species of animals, and in different races of men, we
shall find that the size of these ganglia corresponds very closely
with the degree of intelligence possessed by the individual. We
have already traced, in a preceding chapter, the gradual increase
in size of the hemispheres in fish, reptil^ birds and quadrupeds:
four classes of animals which may be arranged, with regard to the
amount of intelligence possessed by each, in precisely the same
order of succession. Among quadrupeds, the elephant has much
the largest and most perfectly formed cerebrum, in proportion to
the size of the entire body; and of all quadrupeds he is proverbially
the most intelligent and the most teachable. It is important to
observe, in this connection, that the kind of intelligence which
cbaractenzes the elephant and some other of the lower animals,
and which most nearly resembles that of man, is a teachable intelli-
gence; a very different thing from the intelligence which depends
upon instinct, such as that of insects, for example, or birds of pas-
sage. Instinct is unvarying, and always does the same thing in the
same manner, with endless repetition; but intelligence is a power
which adapts itself to new circumstances, and enables its possessor,
by comprehending and retaining new ideas, to profit by experience.
It is this quality which distinguishes the higher classes of animals
from the lower; and which, in a very much greater degree, con-
stitutes the intellectual superiority of man himself. The size of
the cerebrum in man is accordingly very much greater, in propor-
tion to that of the entire body, than in any of the lower animals;
while other parts of the brain, on the contrary, such as the olfactory
ganglia or the optic tubercles, are frequently smaller in him than
in them. For while man is superior in general intelligence to all

408

*HE BBAIK.

the lower animals, he ia inferior to manjr of them in the acuteneas
of the special senses. ■

As a general rule, also, the size of the cerebrum in dlflerent |
races and in different individuals corresponds with the grade of
their intelligence. The size of the cranium, oa compared urith that
of the face, is smallest in the savage uegro and Indian tribes; larger
in the civilized or semi-civilized Chinese, Malay, Arab^and Japan- ■
ese; while it is largest of at! in the enlightened European races.
This diflfercnce in the development of the brain is not probably an
effect of loQg-continued civilization or otherwise; but it is, on the
contrary, the superiority in cerebral development which makes
some races readily susceptible of civili/Jition, while others are
either altogether incj^pabte of it, or can only advance in it to a
certain limit. Although all races therefore may, perhaps, be said
to start from the same level of absolute ignorance, yet after the ■
lapse of a certain time one race will have advanced further in |
civilization than anotlier, owing to a auperior capacity for improve'
ment, dependent on original organization. m

The same thing is true with regard to different individuals. At m
birth, all men are equally ignorant; and yet at the end of a certain
period one will have acquired a very much greater intellectual
power than another, even under similar conditions of training,
education, dx. He has been able to accumulate more information
from the same sources, and to use the same experience to better
advantage than his utfsuciates; aud the result of this is a oertain
intellectual superiority, which becomes still greater by its own
exeroiae. Tbis superiority, it will be observed, lies not so much
in the power of perceiving external objects and events, and of re-
cognizing the connection between them, as in that of drawing con*
olusiuns from one fact to another, and of adapting to new ootnbina-
tions the knowledge which has already been acquired.

It is this particular kind of intellectual did'erence, existing in a
marked degree, between animals, races, and individuals, which cor-
responds with the difference in development of the oerebrul heini*
spheres. We have, thcroforo, evidence from three different sourees
that the cerebral hemispheres are the seat of the reasoning powers,
or of the Intellectual faculties proper. Firnt, when thew ganglia
are removed, in tbe lower animals, the intellectual faculties are the
only oues which are lost. Secondly, injury to these ganglia, in the
humau subject, is fullowed by a eorresi>onding impairment of the
aame faculties. Thirdly, in different species of animals, as well as

HEUI8PHEBSS. 409

in different races of men and in different individuals, the develop-
ment of these faculties is in proportion to that of the cerebral
hemispheres.

When we say, however, that the hemispheres are the seat of the
iDtellectnal facnlties, of memory, reason, judgment, and the like,
we do not mean that these faculties are, strictly speaking, located
in the sufaatance of the hemispheres, or that they belong directly to
the matter of which the hemispheres are composed. The hemi*
spherical ganglia are simply the instruments through which the
int^ectual powers manifest themselres, and which are accordingly
necessary to their operation. If these instruments be imperfect in
stractnre, or be damaged in any manner by violence or disease, the
manifestations of intelligence are affected in a corresponding degree.
So far, therefore, as the mental faculties are the subject of physio-
logical research and experiment, they are necessarily connected
with the hemispherical ganglia; and the result of investigation
shows this conneotion to be extremely intimate and important in
its character.

There are, however, various cireumstances which modify, in
particular cases, the general rule given above, viz., that the lai^er
the cerebrum the. greater the. intellectual superiority. The func-
tional activity of the brain is 'modified, no doubt, by its texture aa
well as by its size; and an increased excitability may compensate,
partially or wholly, for a deficiency in bulk. This fact is some-
times iUuBtrated in the case of idiots. There are instances where
idiotic children with small brains are less imbecile and helpless
than others with a larger development, owing to a certain vivacity
and impressibility of organization which take the place, to a certain
extent, of the purely intellectual faculties.

This was the case, in a marked degree, with a pair of dwarfed
and idiotic Central American children, who were exhibited some
years ago in various parts of the United States, under the name of
the " Aztec children." They were a boy and a girl, aged respectively
about seven and five years. The boy was 2 feet 9} inches high, and
weighed a little over 20 pounds. The girl was 2' feet 6} inches
high, and weighed 17 pounds. Their bodies were tolerably well
proportioned, but the cranial cavities, as shown by the accompany-
ing portraits, were extremely small.

The an tero- posterior diameter of the boy's head was only ^^
inches, the transverse diameter less than 4 inches. The antero-
posterior diameter of the girl's head was 4^ inches, the transverse

410

ihaI

diameter only SJ inches. The liabiia of these childreo, so far as

regards feeding and taklug care of themselves, were those of chil-

Fig. 139.

AlTIc Cllll.nats.— TshMfrou lib. •( Sratind mtvq jmranrag*.

dren two or three years of age. They were incapable of learning
to Ifllk, and could only repeat a few isolated words. KotwithMAnd-
ing, however, the extremely limited range of their intelleciti&l
powers, these children were remarkably vivacious and excitable.
While awake they were in almost constant motion, and any n«w
objector toy presented to them immediately attracted their atten-
tion, and evidonily awakened a lively curiosity. They were ac-
cordingly easily influenced by proper management^ and understood
readily the meaning of those who addressed them, so far as this
meaning could be conveyed by gesticuUiion and the tones of ihe
voice. Their expression and general appearance, though decidedly
idiotic, were not at all disagreeable or repulsive; and they were
mauh lesK troublesome to the persons who had them in charge than
is oden the case with idiots possessing u larger cerebral development

II may also be observed that the purely intellectual or reasoning
powers are not the only element in llie mental superiority of cenaio
races or of particular individuals over their assocutea. There ia
also a certain rapidity of perception and strength of will which may
sometimes overbalance greater intellectual acquirements and mure
cultivated reasoning powers. Those, however, are diflerent facul-
ties from the latter; and occupy, as we shall herealYer see, differeoC
parts of the encephalon.

A very remarkable physiological doctrino, dependent partly on
the foregoing facts, was brought forward some years ago by Oall
and Spurzheim, under the name of Phrenology. These observers
recognized the fact that the intellectual powers are andoubttnlly

HEUISPHEBES. 411

■eated id the brain, and that the development of the brain is, as a
general rale, in oorrespondeoce with the activity of these powers.
They noticed also that in other parts of the nervoas system, different
fanctioDS occapy different situations; and regarding the mind as
made np of many distinct mental faculties, they conceived the idea
that these different faculties might be seated in di&erent parts of
the cerebral mass. If so, each separate portion of the brain would
nndonl^tedly be more or leas developed in proportion to the activity
of the mental trait or faculty residing in it. The shape of the head
would then vary in different individuals, in accordance with their
mental pecnliarittes ; and the character and endowments of the in-
dividual might therefore be estimated from an examination of the
elevations and depressions on the surface of the cranium.

Accordingly, the authors of this doctrine endeavored, by examin-
ing the heads of various individuals whose character was already
known, to ascertain the location of the different mental faculties.
In thia manner they finally succeeded, as they supposed, in accom-
plishing their object; after which they prepared a chart, in which
the snrface of the cranium was mapped out into some thirty or forty
different regions, corresponding with as many different mental traits
or faculties. With the assistance of this chart it was thought that
phrenology might be practised as an art; and that, by one skilled
in its application, the character of a stranger might be discovered
by simply examining the external conformation of his head.

We shall not expend much time in discussing the claims of phre-
nology to rank aa a science or an. art, since we believe that it has
of late years been almost wholly discarded by scientific men, owing
to the very evident deficiencies of the basis upon which it was
founded. Passing over, therefore, many minor details, we will
merely point out, aa matters of physiological interest, the principal
defects which must always prevent the establishment of phrenology
as a science, and its application aa an art.

First, though we have no reason for denying that different parts
of the brain may be occupied by different intellectual faculties,
there is no direct evidence which would show this to be the case.
Phrenologists include, in those parts of the brain which they em-
ploy for examination, both the cerebrum and cerebellum; and they
justly regard the external parts of these bodies, viz., the layer of
gray matter which occupies their surface, as the ganglionic portion
in which must reside more especially the nervous functions which
they possess. But this layer of gray matter, in each principal por-

412

TBB BRAIN.

tiou of the brain, isconUiiuotiatliroug^iout. There is no anatomical
division or limit between its different parti, like thate between
the different ganglia in other portions of the nervous system; and
consequently such divi»toDa of the cerebrum and cerebellum must
be altogether arbitrary in ehziracter, and not dependent on auy
anatomical batiis.

Secondly, the only means of ascertaining tlie locatioa of the
difterent menial traits, supposing them lo occupy different, part* of
the brain, would be that adopted by Gall and Spurzheim, viz^ to
make an aocurate comparison, in n sufficient number of oases, of the
form of the head in individuals of known character. But the prac-
tical difficulty of accomplishing this is very great. It requiros a
long acquaintance and close observation to learn accurately the
uharactor of a single person ; and it is in this kind of observation,
more than in any other, that we are proverbially liable to mistakes.
It is extremely improbable, therefore, that either Gall or Spurzheim
could, in a single lifetime, have accomplished this comparison in so
many instances as to furnish a reliable basis for the ooostructioo of
a phreTtulugicuI chart.

A still more serious practical difficulty, bowever, is the following.
The different intellectual faculties being supposed to reside in the
layer of gray substance constituting the surfaces of the cerebrum
and cerebellum, they must of course be distributed throughout this
layer, wherever it oxiata. Gall and Spurzheim located all the mental
faculties in those parts of the brain which are accessible to external
exploration. An examination «f different sections of the brain
will show, however, that the greater portion of the gray substance

is so placed, that its quantity cannot he
Hg- 140. estimated by an external examination

through the skull. The only portions
which are expose^l to such an exainina-
tiun are the upper and lateral portions
V '.^-VA^^^i **^ t^® convexities of the hemispheres,
together with tlie posterior edge and
part of the uniler surface of the cere-
bellum. (Fig. 140.) A very extensive
portion of the corobrsl surface, however,
remaiua concealed in such a manner that
it cannot possibly be subjected to ex-
amination, viz., the entire base of the
braiu, with the under surface of the an-

}

D(aar»ie »[ ih* DsAiii m htd.
■bowing til DM punlnii* wlikk >» ox-
PVMi to •SBinluMlaD.

HEHISCHSBBS.

413

Pig. Ml.

tenor and middle lobes (i, s); the upper BarPace of the cerebellum
(■) and the inferior surface of the posterior lobe of the cerebrum
which covers it (4); that portion of the cerebellum situated above the
medulla oblongata(a); and the two opposite convoluted surfaces in
the fissure of Sylvius («, 7), where the anterior and middle lobes of
the cerebram lie in contact with each other. The whole extent,
also, of the cerebral surfaces which are opposed to each other in the
great longitndinal fissure (Fig. 141), throughout its entire length,
are equally protected by their position, and
concealed from external examination. The
whole of the convoluted surface of the brain
most, however, be regarded as of equal im-
portance in the distribution of the mental
qualities; and yet it is evident that not
more than one-third or one-quarter of this
snrface is ao placed that it can be examined
by external manipulation. It must further-
more be recollected that the gray matter of
the cerebrum and cerebellum is everywhere
convoluted, and that the convolutions pene-
trate to various depths in the substance of
the brain. Even if we were able to feel, therefore, the external
surface of the brain itself, it would not be the entire convolutions,
but only their superficial edges, that we should really be able to
examine. And yet the amount of gray matter contained in a given
space depends quite as much upon the depth to which the convolu-
tions penetrate, as npon the prominence of their edges.

While phrenology, therefore, is partially founded upon acknow-
ledged physiological facts, there are yet essentially deficiencies in
its scientific basis, as well as insurmountable difilculties In the way
of its practical application.

TnniTerM laetioD of B ■ a i * ,
(howlng depth of great 1od(1-
indlnftl BHore, kt a.

Cebebelluh. — The cerebellum is the second ganglion of the
encephalon, in respect to sizei If it be examined, moreover, in
regard to the form and disposition of its convolutions, it will be
seen that these are much more complicated and more numerous
than in the cerebrum, and penetrate much deeper into its substance.
Though the cerebellum therefore is smaller, as a whole, than the
cerebrum, it contains, in proportion to its size, a much larger quan-
tity of gray matter.

In examining the comparative development of the brain, also, in

4T4

THE BltAtTT.

different classes and species of aQimals, we find that tlie cerebellam
Dearly always keeps paec, in ttiis respect^ with the cerebrum. These
factfi wtiuhl lend us to regard it as a ganglion hardly secondary in
importance to the cerebrum itself.

Physiologists, however, have thug for failed to demonstrate the
nature of its function with the same degree of precision as that of
many other parts of the brain. The opinion of Gall, which located
iu the cerebellum the sexual impulse and instincts, is at the present
day generally abandoned; for the rcnson that it has not been found
to be sufficiently supported by anatomical and experimental focU,
many uf which ore indeed directly opposeil to it. The opiaioo
which has of late years been received with the most favor is that
first advocated by Klourens, which attributes to the cerebellum the
power of associating or "co-ordinating" the diflcrent volunuiry
movements.

It is evident, indeed, that such a power does actually reside in
Bome part of the nervous system. No movements arc effected by
the independent contraction of single muscles; but always by
several muscles acting in harmony with each other. The number
and complicaliun of these associated movements vary in different
classes of animals. In fish, for example, progression is accom-
plished in the simplest possible manner, v'lv.., by the lateral flexion
and extension of the vertebral column. In serpents it is much ttie
same. In frogs, lizards, and turtles, on Iho other band, the four
Jointed extremities come into piny, and the movements are some*
what complicated. Tliey arc «till more so in birds and f^uadrnpeda;
and Gually, in the human subject they become both varied and
complicated in the highest degree. Even in maintaining the ordi-
nary postures of standing and sitting, there are many diflerent mus-
cles acting together, in each of which the degree of contraction, in
order to preserve the balftoce of the body, must be accurately pro-
portioned to that of the olhersi. In the motions of walking aad
running, or in the still more delicate movements of the hands and
fingers, this harmony of muscular action becomes still more evident,
and is seen also to be absolutely indispensable to the efficiency of
the muscular apparatus.

The opinion which locates the above harmonizing or associating
power in the cerebellum waa first suggested by the effects observed
alYcr experimentally injuring or destroying this part of the braio.
If the cerebellum be exposed in a living pigeon, and a portion of
its substance removed, the animal exhibits at once a peculiar nn-

CGREBBLLUV.

416

certainty io bis gait, and in tbe moTement of his wtngs. If the
injury be more extensivu, he loses aliogetbor tlie power of flight,
and can walk, or even stand, only with great difficulty. This is not
owing to any actual paralysis, for the movements of the limbs are
excee<iingly rapid ami energetic; but is due to a peculiar want of
control over the muscular oon tractions*, precisely similar to that
which is seen in a man in a state of intoxication. The movements
of the legs and wings, though forcible and rapii'l, are confused and
blundering; ao that the animnl cannot direct liis steps to any par-
ticular spot, nor support himself in the ftir by flight, ilu reels and
tumbles, but can neither walk nor fly,

Kg. 142.

.-^^i''*

The senses aod intelligence at the same time are unimpaired. It
is extremely curious, as first remarked by Longet, to compare the
diflerent phenomena produced by removal of the ccrebrom and
that of the cerebellum. If we do these operations upon two dif-
fereot [Hgeons, and place the animals aide by side, it will be seen
that the first pigeon, from whom the cerebrum only has been re-
moved, remains standing firmly upon his feet, in a condition of
complete repose; and that when aroused and compelled to stir, he
moves sluggishly and unwillingly, but otherwise acts in n perfectly
DBtural manner. The second pigeon, on the other hand, from
whom the cerebellum only has been taken away, ia in a constant
stale of agitation. He ia «asily terrified, and endeavors, frequently
with viotcDt struggles, to escape the notice of those who are

41G

IS BRAiy.

watching him; but bis movemeots are sprawling and unnatural,
and are evidently no longer under tli« eflectual control of the will.
(Fig. 142.) If the entire cerebellum be destroyed, the animal \m
no longer capable of nssuming or retaining any nittaral poetnre.
His legs and wings are almost constantly agitated with ineEIectual
struggles, which are evidently voluntary in character, but are a;
the same time altogether irregular and confused. Death generally ■
takes place after this operation within twenty-four hours.

We have often performed the above operation, and always with
the same eifect, Indeed there are few experiments that have been
tried upon the nervoua system, which give results so uniform and
so constant as this. Taken hy themselves, these reaultii would
invariably sustain the theory of Flourcns, which, indeed, is founded
entireiy upon them, ■

Dut we have met with another very important fact, in this respect,
which has hitherto escaped notice. That ifi, that birds, which have
lost their power of muscular co-ordination from injury of the cere-
bellum, may rtcovtr this jiowcr in process o/timt, notwithstanding that
a Urge portion of the cerebellum has been permanently removed.
Usually such an operation upon the cerebellum, as we have men-
tioned above, is fatal within twenty-fonr hours, probably on account M
of the close proximity of the medulla oblongata. But in some ■
instances, the pigeons upon which we have operated have survived,
and in these cases a re-establishment of the coordinating power I
took place.

In the first of these instances which was observed, about two-
thirds of the cerebellum was taken away, by an opening in the
posterior part of the cranium. Immediately after the operation,
the animal showed all the usual eftbct^ of the operation, being
incapable of flying, walking, or even standing still, but reeled and
sprawled about in a perfectly hclplcM manner. In the course of five
or six days, however, he had regained a very considerable control
over his voluntary movomonts, and at the end of sixteen days bis
power of muscular co-ordination was so nearly perfect, that its de-
ficiency, if any existed, waa imperceptible. He was then killed; and
on examination, it was found that hid cerebellum remained in oearly
the same condition as immediately after the operation; about two-
thinU of its substance being deficient, and no attempt having been
made at its regeneration. The accompanying figures show cbo
appearance of parts, iu this case, as compared with the brain of a
healthy pigeon.

CBBBBKLT.U1I.

417

Fig. 143.

Hg. 144.

We have also met with three other eases, similar to the above, in
which about one-hair of the cerebellum waa removed by operation. ,

Bbaik «p Hialtbt PiaBoa— Proflla
t1«w —I. HawUpbMa. 1 Optic tab«n)]«. S.
Car*b«llBB 1. Optic ner*<>. S. Ufdulla cb-

Fig. 145.

Braiit of Opibatid Pkieob — / w'^^
Profile Tlew— «hDwiiif tlic muillulloii
of cerebellum.

■>^^

,V^J-C'

Ftg. 146.

(,'

BkAta nr Hbaltbt Piqkox— Paite>
ifor rlcw.

■ Oo

Bbaik op Opbbatbd Piobob—
PualarloT view — ■h<ivlii| (lie DiBllls-
tloa of eerrbpllum.

'U^'

The loss of co-ordinating power, immediately after the operation,
thongh leaa complete than in the instance above mentioned, was
perfectly well marked in character; and in little more than a fort-
night the animale had nearly or quite recovered the natural control
of their motions.

These instances show, accordingly, that a large portion of the
oerebeUnm may be wanting without a corresponding deRciency of
the co-ordinating power. If the theory of Flourens be correct,
therefore, these cases can only be explained by supposing that
those parts of the cerebellam which remain gradually become en-
abled to supply the place of those which are removed. It is more
probable, however, that the loss of co-ordinating power, which is
immediately produced by taking away a considerable portion of
this nervous centre, is to be regarded rather as the effect of the
sudden injury to the eer^Uum aa a whole, than as due to the mere
removal of a portion of its mass.

Morbid alterations of the cerebellum, furthermore, particularly
of a chronic nature, such as slow inflammations, abscesses, tumon:,
&&, have often been observed in the human subject, without giving
rise to any marked disturbance of the voluntary movements.
27

418

THE BRMN.

Oil the otlicr liand, many facte derived from comparative anatomy
seem to favor the opinion of Flourcna. If wc compare different
classes of animals with each other, as &s\i with reptiles, or birds
vilh quadrupeds, iu which the developmeut and actirity of the
entire nervous system vary extremely, the results of the comparison
will be often contradictory, liut if the comparison be made be-
tvecn different species in which the general structure and plan of
organization are similar, we often find the development of the cere-
bellum tu correspond very clusety with the perfection and variety
of the voluntary movements. The frog, for example, is an aquatic
reptile, provided with anterior and posterior extremities; but its
movement^, though rapid and vigorous, are exceedingly simple in
character, consisting of little else than fluxion and extension of the
posterior limbs. The cerebellum in this animal is exceedingly
small, H8 compared with the rest of the brain; being nothing more
than a thin, narrow ribbon of nervous matter, stretched across the
upper part of the fourth ventricle. In the common turtle we have
another aquatic reptile, where the movementsof swimming, diving,
progression, &c., ore acconipliahed by the consentaneous action of
anterior and posterior extremities, and where the motions of the
head and neck are aUo much more varied than in the frog. In
this instance the cervbellum is very much more highly developed
than io the former. In the alligator, again, a reptile whose motions,
both of the head, limbs, and tail, approach very closely to those of
the quadrupeds, the cerebellum is still larger in proportion to the _
remaiiuDg ganglia of the encephalon. f

The complete function of the cerebellum, accordingly, aa a nerv-
ous centre, cannot be regarded as positively ascertained! ; but so far
as we may rely on the results of direct experiment, this organ has
evidently such an initmate and peculiar connection with the volao*
tary movements, that a sudden and extensive injury inflicted upon
\iR substance in always followed by an immediate, though temoo^^
rary, disturbance of the co-ordinating power. ^^^^

TUBSRCULA Qdadriobhika. — These bodies, DotwithstaodiDg
their small aize, are very important in regard to their function.
They give origin to the optic nerves, and preside, as ganglia, over
the sense of sight; on which account they are also known by the
name of the " optic ganglia." Their development corresponds very
closely with that of the external organs of vision. Thus, they are
large in Bab, reptiles, and birds, in which the eyeball is fur the

TUBERCULA QUADBIOBHiyA. 419

most part very large in proportion to the entire head ; and are small
in qoadropeds and in man, where the eyeball is, comparatively
speaking, of insignificant size. Direct experiment also shows the
close oonaection between the tubercula quadrigemina and the sense
of sight. Section of the optic nerve at any point between the
retina and the taberclea, produces complete blindness ; and destruc-
tion of the tuberoles themselves has the same effect Bat if the
division be, made between the tubercles and the cerebrum, or if the
cerebram itself be taken away while the tabercles are left un-
toached, vision, as we have already seen, still remains. It is the
tabercles, therefore, in which the impression of light is perceived.
So long as these ganglia are uninjured and retain their connection
with the eye, vision remains. As soon as this connection is cut
o£^ or the ganglia themselves are injared, the power of vision ia
destroyed.

The tabercala quadrigemina not only serve as nervous centres
for the perception of light, but a reflex action also takes place
through them, by which the quantity of light admitted to the eye
is regulated to suit the sensibility of the pupil. In darkness and
in twilight, or wherever the light is obscure and feeble, the pupil
is enlarged by a relaxation of its circular fibres, so as to admit as
large a quantity of light as possible. On first coming into a dark
room, accordingly, everything is nearly .invisible; but gradually,
as the pupil dilates and as more light is admitted, objects begin to
show themselves with greater distinctness, and at last we can see
tolerably well in a place where we were at firat unable to perceive
a single object. On the other hand, when the eye is exposed to an
Quasnally brilliant light, the pupil contracts and shuts out so much
of it as would be injurious to the retina.

The above is a reflex action, in which the impression received by
the retina is transmitted along the optic nerve to the tubercula
qnadrigemina. From the tubercles, a motor impulse is then sent
out through the motor nerves of the eye and the filaments dis-
tributed to the iris, and a contraction of the pupil takes place in
conaeqaenoe. The optic nerves act here as sensitive fibres, which
convey the impression from the retina to the ganglion; and if
they be irritated in any part of their course witb the point of a
needle, the result is a contraction of the pupil. This influence is
not communicated directly from the nerve to the iris, but is first
sent inward to the tubercles, to be afterward reflected outward by
the motor nerves. So long as the eyeball remains in connection

420

rs BKAIN.

witli the brnin, mechariical irritation of tlie oplic nerve, as we have
^hown above, causes contraotioo of the pupil; but if the nerve be
divided, and the extremity which remains in connection with the
eyeball be subjected lo irntation, no elTcct upon the pupil is pro-
duced.

The anatomical arrangement of the optic nerves, and the connec-
tions of the optio tubercles, are modified in a remarkable degree in
diflTerent animals, to corre8[>ond with the position of the two eyes.
In fish, for example, the eyes are so placed, on opposite aides of the
head, that their axes cannot be brought into parallelism with each
other, and the two eyes can never bo directed together to the same
object. In these animals, the opttc nerves cross each other at the
base of the brain without any intermixture of their fibres; that
from the right optic tubercle passing to the left eye, and that from
the lefl optic tubercle passing to (he right eye. (Fig. 147.) The two

Pig. 147.

Fig. 148.

»r C<ii> — I Htcbi uplicai'rTa. 3 LvH
•pit; Dvrtc X Klfhtopllc lulwrcl*. 4.
Li«n 'ipilriati^rfl*. i. t. \Um\*tk*tm

T. Ui^alla ubl,'il|Bii.

IxrBNiflH 8rkr4''B or B<i«rs ap
Fowl,,— I lll(M ••ptXiMT*. 1 un«p(k

»plle catMMla. 0, * He u lap bans. 7. lU-

nervous cords are here totally distinot from each other throughout
their entire length ; and are only connected, at the point of cross-
ing, by intervening areolar tissue. Impressions made on the right
eye must therefore be perceived on the left side of the brain ; while
those which enter the left eye arc conveyed to the right side of the
braio.

klNttlQEMIKA.

421

in birds, also, the axes of ihe two eyca are ao widelj divergent
that ao ubject cannot be diBtioclIy id focas for both of them at the
same time. The optic nerves are here utiilud, and apparently sol-
ilered together, at their point of crossing: but the decusatioa of
their fibres is nevertheless complete. (Fig. 148.) The nervous fila-
ments coming fruiii the luft side pass altogether over to the right;
and those coming from the right side pass over to the left. The
result of direct experiment on the croaseil action of the tubercles in
these animals corresponds with the anatomical arrangement of the
nerroQs fibres. If one of the optic tubercles be destroyed in the
pigeon, complete blindness is at once produced in the eye of the
oppovite side; bat vision remains animpuired in ihe eye of the side
on which the injury was inflictetL

In the human subject, on the other hand, where the visual axes
are parallel, and where both eyes are simultaneously directed to the
same object, the optic nerves deuuasate with each other in such u
manner as to form a oonnection between the two opposite sides, as

Pig. 149.

Cnvcxar Optic Kmvisiir M a«.— 1. 3. RlitlaodUn *r«bK]ti 1. T^triutiioh irf ApO*
kima. i, t.^TubmulB lundrlfrmliia.

well as between each tubercle and retina of the same nide. (Fig.
149.) This decussation, which is somewhat complicnted, take-s place

THB BRAiy.

in the following manner. From each oi^lic tubercle three different
bundles or " tracts" of nervous fibres are given off. One net pusaca
ncroM transversely at the point of ilecassatlon, and, turning back-
ward, t«rniinat«s in the tubercle of the opposite side; another, cross-
ing diagonally, continues onward to tlie opposite eyeball; while a
third passes directly forward to the eyeball of the same side. A
fourth set of fibres, still, passes across, in front of the dccussaUon,
from the retina of one eye to that of the opposite side. We have,
therefore, by tliis arrangement, tlie two retinae, as well as the two
optic tubercles, connected with each other by oomniissoral flbrcs;
while each tubercle in, at the same time, connected both with its
own retina and with that of the opposite side. Tt is undoubtedly
owing to these connections that when, in the human subject, tbe
eyes are directed iu their proper axes, the two relinu, as well as
ihe two optic tubercles, act as a single organ. Vision is single,
ibercfore, though there are two images upon the retinie. Double
vision occurs only when the eyeballs are turned out of their proper
direction, so that the parallelism of their axes is lost, and the image
no longer falhi upon corresponding parts of the two relinra.

ible
per 1
age ■

TcBKH AxNai.ABE.— The collection of gray matter imbedded in
the deeper portions of the tuber anntilare occupies a situation near
the central part of the brain, and lies directly in the course of the
ascending fibres of the anterior and posterior columns of the cord.
Tliia ganglion is immediately connected with the functions of sensa-
tion and voluntary motion. We have already seen that these fuoo-
tions arc not destroyed by taking away the cerebrum, and that they
also remain after removal of the cerebellum. According to the ex-
periments of Longet, even after complete removal of the olfactory
ganglia, the cerebrum, cerebellum, optic tubercles, corpora striata
and optic thalami, and when nothing remains in the cavity of the
cranium but the tuber annulare and the medulla oblongata, ilie
animal is still sensitive to external impressions, and will still en-
deavor by voluntary movements to escape from a painful irritation.
The sameobserver has found, however, that as soon as tbe ganglion
of the tuber annulare is broken up, all manifestations of sensation
and volition cease, and even consciousness no longer appears to M
exist. The only movements which then follow external irritation
are the oocaaional convulsive motions which are due to reflex action _
of the spinal cord, and which may be readily distinguished from
those of a voluntary character. The animal, under these circum-

KEDULLA OBLONGATA. 423

stances, is to all appearance reduced to the condition of a dead
body, except for Uie movements of respiration and circulation,
which still go on for a certain time. The tuber annulare must
therefore be regarded as the ganglion bj which impressions, con-
veyed inward through the nerves, are first converted into conscious
sensations; and in which the voluntary impalses originate, which
stimulate the muscles to contraction.

We must carefully distinguish, however, in this respect, a simple
sensation from the ideas to which it gives origin in the mind, and
the mere act of volition from the train of thought which leads to
it. Both these purely mental operations take place, as we have
seen, in the cerebrum ; for mere sensation and volition may exist
independently of any intellectual action, as they may exist after
the oerebmm has been destroyed. A sensation may be felt, for
example, without our having the power of thoroughly appreciating
it, or of referring it to its proper source. This condition ia oiWn
experienced in a state of deep .sleep, when, the body being exposed
to cold, or- accidentally placed in a constrained position, we feel a
sense of snaring, without beiug able to understand its cause. We
may even, under such circumstances, execute voluntary movements
to escape the cause of annoyance; but these movements, not being
directed by any active intelligence, fail of accomplishing their ob-
ject. We therefore remain in a state of discomfort until, on awak-
ening, the activity of the reason and judgment is restored, when the
offending cause is at once removed.

We distioguish, then, between the simple power of sensation,
and the power of fully appreciating a sensitive impression and of
drawing a conclusion from it. We distinguish also between the
intellectual process which leads us to decide upon a voluntary
movement, and the act of volition itself. The former must precede,
the latter must follow. The former takes place, so far as experi-
ment can show, in the cerebral hemispheres; the latter, in the gan-
glion of the tuber annulare.

UsDULLA Oblongata. — The last remaining ganglion of the en-
cephalon Is that of the medulla oblongata. This ganglion, it will
be remembered, is imbedded in the substance of the restiforra body,
occnpying the lateral and posterior portions of the medulla, at the
point of origin of the pneumogastric nerves. This portion of the
brain has long been known to be particularly essential to the pre-
servation of life; so that it has received the name of the "vital

424

BRACK.

point," or the " vital knot." All the other part-? of the brain mnv
be injured or removed, as we bave already seen, without the imme*
diate and oecesaary destractioQ of life ; but so aoon as the medulla
oblongata is brokou up, and its ganglion destroyed, respiration
oeascji iniitanLancouflly, and the circulation also aoon comes to an
uod. Btfuioval of the medulla oblongata produces, therefore, as its
intTnediate ami direct result, a stoppage of respiration; and deatb
takes pince principally a^ a conscqueoce of ibis fact.

Floureos and L<oiigcl have detertnined, with considerable accu*
racy, the precise limits of this vital spot in the medulla obloognU.
Flourens ascertained that in rabbits it extended from just above
the origin of the pneuinogaatric nerve, to u level situated three lines
and a half below this origin. In larger animals, its extent is pro*
portionately increased. Longet ascertained, furthormoro, that the
properties of the medulla were not the same throughout its entire
thickness; but that its posterior and anterior parts might be de
8troyt)d with comparative impunity, the peculiarly vita) spot being
confined to theintermediftte portions. This vital point oocordingly
is situated in the layer of gray matter, imbedded in the thickness
of the reatiform bodies, which has been previously spoken of as
giving origin to the pneumcgastric nerves.

The precise nature of the connection between this ganglion and
the function of respiration may be described as follows. Tha
movements of rcspiratii^n, which tblluw each other with incessant
regulnrity through the whole period of life, ore not voluntary
movements. We may, to a certain e.xtent, hasten or retard them
Bt will, but our power over thoin, even in ibis respect, is estremoly
limited ; and in point of fact they are performed, during the greater
part of the time, in a perftjctly quiet and regular manner, without
our volition and even without our consciousness. They continue
uninterruptedly through the deepest slumber, and even in a cou-
diticui of intMinsibility from accident orditteosc.

These movements are the result of a reflex action taking place
through the mcdalla oblongata. The impression which gives rise
to tbem originalee principally in the lungs, irom the accumulation
of carbonic acid in the pulmonary vessels and air-cells, is trans-
mitted by the pncumogastric nerves to the medulla, and is thence
reflected back along the motor nerves to the respiratory mosoles.
These muscles arc then called into action, producing an expansion
of the chest. The impression eu conveyed to the medulla is usually
uuperceived by the consciousness. It i^ generally converted directly

VEDULLA OBLONGATA. 426

ioto a motor impalw, without attrsoting oar attention or giving
rise to any oonscioag sensation. Bespiration, accordingly, goes on
perfectly well without oor interference and without our knowledge.
The nerrona impression, however, conveyed to the medulla, though
Qsnally imperceptible, may be made evident at any time by volao-
tarily soqiending the respiration. As the carbonic acid begins to
aocumnlate in the blood and in the lungs, a peculiar sensation makes
itself felt, which grows stronger and stronger with every moment,
and impels us to recommence the movements of inspiration. This
peculiar sensatioo, entirely different in character from any other, is
designated by the French under the name of "besoin de respirer."
It becomes more argent and distressing, the longer respiration is
soapended, until finally the impulse to expand the chest can no
I<HigeT be resisted by any effort of the will.

During ordinaiy respiration, therefore, each inspiratory move-
ment is excited by the partial vitiation of the air contained in the
langs. As soon as a new supply has been inhaled, the impulse to
respire is satisfied, the muscles relax, and the chest collapses. In
a few seconds the previous condition recurs and the same move-
ments are repeated, producing in this way a regular alternation of
inspirations and expirations.

Since the movements of respiration are performed partly by the
diaphragm and partly by the intercostal muscles, they will be
differently modified by injuries of the nervous system, according to
the spot at which the injury is indicted. If the spinal cord, for
example, be divided or compressed in the lower part of the neck,
all the intercostal muscles will be necessarily paralyzed, and respi-
ration will then be performed entirely by the diaphragm. The
ohest in these cases remaining motionless, and the abdomen alone
rising and falling with the movements of the diaphragm, such
respiration is called "abdominal" or "diaphragmatic" respiration.
It is a common symptom of fracture of the spine in the lower
cervical region. If the phrenic nerve, on the other hand, be
divided, the diaphragm will be paralyzed, and respiration will then
be performed sJtogether by the rising and falling of the ribs. It
is then called "thoracic" or "costal" respiration. If the injury
inflicted upon the spinal cord be above the origin of the second
and third cervical nerves, both the phrenic and intercostal nerves
are ai once paralyzed, and death necessarily takes place from suf-
focation. The attempt at respiration, however, still continues in
these cases, showing itself by ineffectuul inspiratory movements of

426

TRR BRAIEf.

the mouth and noetrils. Finally^ if the medulln itself be broken up
by a atoci instrument intnxluced through the foramen magnum, so
as to destroy tho nervous centre in which the above reflex action
takes place, both the power and the desire to breathe are at once
taken away. No attemjit is m»de at inspiratioo, there is no strag-
gle, and no appcaraiioe of suJlering. Tho animal dies simply by
a want of aeration of the blood, which leads in a few moments to
an arrest of the circulation.

It is owing to the above action of the medulla oblongata that in*
juries of this part are bo promptly and constantly fatal. When the
"neck is broken," as in hanging or by sudden falls upon tho head, a
rupture takes place of the transversa ligament of the atlas; the
head, together with the first cervical vertebra, is allowed Ui slide
forward, and the medulla is compressed between the odontoid pro-
cess of the axis in front and the posterior part of the aroh of the
atlas behind. In cases of apoplexy, where any part of the hemi-
spheres, corpora striata, or optic thalami, is the seat of the hemor-
rhage, the patient generally lives at leitst twelve hours; but if the
liemorrhage take place into the medulla itself, or at the base uf the
brain in its immediate neighborhood, so as to compress its sab-
stance, death follows inatantoneously, and by the same mechanism M
as where the medulla is inteniioivally destroyed. ■

An irregularity or want of correspondence in the movements of
respiration is accordingly found to be one of the most threatening
nf ail symptoms in an'eciiuna of the brain. A disturbance or sus-
pension of the intellectual powers does not indicate neccssarilj any
immediate danger to life. Even sensalioo and volition may be im-
paired wilhuut serious and direct injury to the organic functions.
These symptoms only indicate the threatening progress of the dis-
ease, and show that ii is gradually approaching the vital centre. It ■
is common to see, however, as the medulla itself begins to be impli-
cated, & paralysis first showing itself in the respiratory inovemeuts
of the nostrils and lips, while those of the chest and abdomen stiU
go on as uiiual. The cheeks are then drawn in with every inspira-
tion and puffed out sluggishly with every expiration, the nostril*
themselves sometimes participaliitg in these unnatural movements.
A still more threatening symptom, and one which frequently pre-
cedes death, is an irregulur, hesiuiting respiration, which sometimes
attracts the attention of the physician, oven before tho remaining
cerebral functions are seriously impaired. These phenomena de-

HSDULLA OBLONGATA. 427

pend on the coDnection between the Teiq)irator7 movements and the
reflex action of the medulla oblongata.

We have now, in studying the functions of varioaa puts of the
cerebro-spinal sj^stem, become familiar with three different kinds of
reflex action.

The first ia that of the spinal cord. Here, there is no proper
sensation and no direct consciousness of the act which is performed.
It is simply a nervous impression, coming from the integament,
and transformed by the gray matter of the spinal cord into a motor
impalse destined for the muscles. This action will take place after
the removal of the hemispheres and the abolition of conscioasness,
as well as in the ordinary condition. The respiratory action of the
medulla oblongata is of the same general character; that is, it is
not necessarily connected with either volition or consciousness.
The only peculiarity in this instance is that the original nervous
impression is of a special character, and its influence is finally
exerted upon a special muscular apparatus. Actions of this nature
are termed, par excellence, reflex actions.

The second kind of reflex action takes place in the tuber annu-
lare. Here the nervous impression, which is conveyed inward
frona the integument, instead of stopping at the spinal cord, passes
onward to the tuber annulare, where it. first gives rise to a con-
scious sensation; and this sensation Is immediately followed by a
volantary act. Thus, if a crumb of bread fall into the larynx, the
seoaation produced by it excites the movement of coughing. The
seasations of hunger and thirst excite a desire for food and drink.
The sexual impulse acts in precisely the same manner; the percep-
tion of particnlar objects giving rise immediately to special desires
of a sexual character.

It will be observed, in these instances, that in the first place,
the nervoos sensation must be actually perceived, in order to pro-
duce its efl^t; and in the second place that the action which
follows is wholly voluntary in character. But the most important
peculiarity, in this respect, is that the voluntary impulse follows
datctly upon the reoeipt of the sensation. There is no intermediate
reasoning or intellectual process. We do not cough because we
know that this is the most effectual way to clear the larynx ; but
simply because we are impelled to do so by the sensation which is
felt at the time. We do not take food or drink because we know
that they are necessary to support life, much less because we under-
stand the mode in which they accomplish this object; but merely

428

TUB BRAIN.

because we desire thetn whenever we feel tlie sensatious of hunger
and thirst.

All actions of this nature are terme<l in«tineliv9. Tfae^r are Tolnn-
iary in cbaraoter, but are performed blindly; that is, without any
idea of the ultimate object to be acccmpliahed by them, and simply
io consequence of the receipt of a particular sensation. Aocord-
itigly experience, judgment, and adaptation have nothing to do with
theae actions. Thus the bee builds bis cell on the plan of a mathe-
matical figure, without performing any mathematical calculation.
The silkworm wraps himself in a cocoon of his own spinning,
certainly without knowing that it is to afford him shelter during
the period of his metamorphoaia. The fowl incubates her eggs
and keeps them at the proper temperature for development, simply
because the sight of them creates in her a desire to do so. The
habits of these animals, it is true, are so arranged by nature, thai
such instinctive actions are always calculated to accomplish an
ultimate object. But this calculation is not made by the animal
himself, and does not form any part of his mental operations.
There is consequently no improvement in the mode of performing
such actions, and but little deviation under a variety of circum-
stances.

The third kind of reflex action requires the co-operation of the
hemispheres. Here, the nervous impression is not only conveyed
to the tuber annulare and converted into a sensation, but, still
following upward the course of the fibres to the cerebrum, it there;
gives rise to a special train of ideas. We understand then the
external source of the sensation, tho manner in which it is calcu-
lated to afTeci us, and how by our actions we may turn it to our
advantage or otherwise. The action which follows, therefore, in
these cases, is not simply voluntary, but reatonahle. It does not
depend directly upon the external sensation, but upon an iutetlec-
tual process which intervenes between the sensation and the voli-
tion. These actions are distinguished, occordinj^ly, by a character
of dcHiiite contrivance, and a conscious adaptation of means to
ends; characteristics which do not belong to any other operations
of the Dervoua ayatem.

The possession of this kind of intolligcncso and reasoning power
is not confined to the human species. We have already seen that
there are many purely instinctive actions in man, as well as in
animals. It is no less true that in the higher animals there is often
the siime exercise of reasoning power as in man. Tho degree of

XBDULtA OBLONGATA. 429

this power is much leas in them than in him, bat its nature is the
Bsnte. Wbenerer, in an animal, we see any action performed with
the evident intentioa of aocompliahing a particular object, to which
it is properly adapted, such an act is plainly the result of reason-
ing powers, not essentially dififerent from our own. The establish-
moDt of aentinelfl by gregarious animals, to warn the herd of the
approach of danger, the reooUecdon uf punishment inflicted for a
putioolar action, and the subseqaent avoidance or concealment of
that action, the teachability of many animals, and their capacity of
forming new habits or of improving the old ones, are all instances
of the same kind of intellectual power, and are qaite different from
instinct, strictly speaking. It is this faculty which especially pre*
dominates over the others in the higher classes of animals, and
which finally attains its maximum of development in the human
species.

430

THE ORANIAt. NKRVBS.

CHAPTER V.

THE CRANIAL NEKTE9.

Ix examining the cranial nerves, we shall find that although they
at first seem quite diQ'erent in their distribution and properties _
rrum the spinal nerves, yet tfacy are in reality arranged for thef
moBt part on the same plan, and may be studied in a similar
manner.

At the outset, however, we llnd that there are three of the ora-
ninl nerves, commonly so called, whioh must be arranged in a class
by themselves; since they have no character in common with the
other nerves originating either from the brain or the spinal cord.
These are the throe nerves of special sense; viz., the Otlactory,
Optic, and Auditory. They are, properly speaking, not so much
nerves as commissures, c^tnnecting ditlerent parts of the encephalic
niAss with each other. They are neither sensitive nor motor, in
the ordinary meaning of these terms; but are capable of conveying
only the special senaation characteristic of the organ with which
they are connected.

Olfactobt Nerves.— We have already described the so called
olfactory nerves as being in reality commissures, connecting the
olfactory ganglia with the central parts of the brain. The moaaea
situated upon the cribriform plate of the ethmoid bone are cooi>
poaed of gray matter ; and even the filaments which they seod
outward to be distributed in the Schneiderian mucous membrane,
are gray and gelatinous in their texture, and quite different from
the fibres of ordinary norvos. The olfactory nerves are not very
well adapted for direct experiment. It is, however, at least certain
with regard to them that they serve to convey the special seasniion i
of smell; that their mechanical irritation doe» not give rise toj
either pain or convulsions; and finally that their destruction,]
together with that of the olfactory ganglia, does not occasion any i
{Miraly^ii nor loss of ordiuary sensibility.

THS CBANIAL VEBVBS. 481

Oftio Nxbtxs. — We have ali^dj given some acconnt of these
nerves and their deoassations, in coDnection with the history of the
tubercula qnadrigemina. Thej oonsist of rounded bundles of white
fibres, running between the tubercles and the retinsa. As the reti-
nae themselves are membranous expansions consisting mostly of
vesicular or cellular nervous matter, the optic nerves, or " tracts,"
must be regarded as commissures connecting the retinae with the
tubercles. We have also seen that they serve, by some of their
fibres, to connect the two retinae with each other, as well as the two
tubercles with each other.

The optio uerrea convey only the special impression of light from
without inward, and give origin to the reflex action of the optic
tubercles, by which the pupil is made to contract. According to
Longet, the optic nerves are absolutely insensible to pain through-
out their entire length. When a gal vanic current is passed through
the eyeball, or when the retina is touched in operations upon the
eye, the irritation has been found to produce the impression of lumi-
nous sparks and flashes, instead of an ordinary painful sensation.
The impression of colored rings or spots may be easily produced
by compressing the eye in particular directions; and a sudden
stroke upon the eyeball will often give rise to an apparent discharge
of brilliant sparks. Division of the optic nerves produces complete
blindness, but does not destroy ordinary sensibility in any part of
the eye, nor occasion any muscular paralysis.

AuDiTOBT Nkbtes. — The nervous expansion in the cavity of
the internal ear contains, like the retina, vesicles or celts as well as
fibres; and the auditory nerves are therefore to be regarded, like
the optio and olfactory, as commissural in their character. They
are also, like the preceding, destitute of ordinary sensibility. Ac-
cording to Longet, they may be injured or destroyed without giving
rise to any sensation of pain. They serve to convey to the brain
the special sensation of sound, and seem incapable of transmitting
any other. Longet* relates an experiment performed by Volta, in
which, by passing a galvanic current through the ears, the observer
experienced the sensation of an interrupted hissing noise, so long
as the connection of the wires was maintained. Inflammations
within the ear, or in its neighborhood, are oflen accompanied by
the perception of various noises, like the ringing of bells, the

■ TniH dtt Phjrsiologiv, toI. ii. p. 286.

482

TBB CRAXIAt, :«BRTaS.

washing of the waves, the hamming of insects; sounda which have
no external existence, but which are simulated by the morbid irri-
tation of the auditory nerve.

It is evident, from the facts detailed above, that the DerveH of
special sense are neither motor or sensilive, properly speaking;
and that they are distinct in their nature from the ordinary spinal
nerves.

The remainder of the cranial nerves, however, present the
ordinary qualities belonging to the spinal nerves. Some of ihem
are exclusively motor in character, olhcm exclusively sensitive;
while most of them exhibit the two properties, to a certain extent,
as mixed nerves. They may be conveniently arranged in three
pairs, according to the regions in which they are distributed, cor-
reBponding very closely with the motor and sensitive roots of the
spina.! nerves. According to such a plan, the arrangement of the
cranial nerves would be as follows: —

Ca&RiAi. Nuthl
X*rt*M of Special Stn-t.
1. OUaclory. 2. OpUo. 3. Anililory.
Molar Ker*«t.
Motor oouli com.
Palli«tloas
Motor oc. uxl«rniis
timall root ot fi'th |Mir

Sontlllr* Xtr*«ii.

Dl>tribaia4 to

]»t FAIR.

SdrAlR.

M r*iB.

H>'t'0^1o»8ILl

Large root of &tti p»ir. Pmc«.

Glirsm-phar^ngiNiL
i'mtumogaatrio.

Neck, &<f.

The above arrangement of the cranial nerves is not absolutely
perfect in all its details. Thus, while the hypoglossal supplies the
muscles of the tongue alone, the glosso-pharyngeal sends part of ^
its sensitive fibres lo tlie tongue and part to the pharynx; and
while the large root of the 6ih pair Is mostly distributed iu the
face, one of its branches, v'xz^ the gustatory, is disthbaled to ihe ■
tongue. Notwithstanding these irregularities, however, the above
division of the cranial nerves is in the main correct, and will be
found extremely useful as an assistant in the study of their func'
tions.

There is no impropriety, moreover, in regarding all the motor
branches distributed upon the face as one nerve; since even the
anterior roots of the spinal nerves originate from the spinal cord, M
each by several distinct filaments, whioh are associated into a single

THK CBANIAL NSBTIS. 488

bundle 011I7 at a certain distance from their point of origin. The
mere fact that two nerves leave the cavity of the cranium by the
same foramen does not indicate that they have the same or even a
similar fdoction. Thus the facial and auditory both escape from
the cavity of the cranium by the foramen auditorium internum, and
yet we do not hesitate to regard them as entirely distinct in their
nature and functions. It is the ultimate distribution of a nerve,
and not its course through the bones of the skull, that indicates
its physiological character and position. For while the ultimate
distributioD of any particular nerve is always the same, its arrange-
ment as to trunk and branches may vary, in different species
of animals, with the anatomical arrangement of the bones of the
skull. This is well illustrated by a fact first pointed out by Prof,
Jeffries Wyman' in the anatomy of the nervous system of the
bQllfh)g. In this animal, both the facial nerve and motor oculi
eztemus, instead of arising as distinct nerves, are actually given
off as branches of the 6th pair; while their ultimate distribution is
the same as in other animals. All the motor and sensitive nerves
distributed to the face are accordingly to be regarded as so many
different branches of the same trunk ; varying sometimes in their
course, but always the same in their ultimate distribution.

The miAar nerves of the bead are in all re^>ects identical in their
properties with the anterior roots of the spinal nerves. For, in the
first place, they are distributed to muscles, and not to the integu-
ment or to mucous membranes; secondly, their division causes
maacnlar paralysis; and thinlly, mechanical irritation applied at
their origin produces muscular contraction in the parts to which
they are distributed, but does not give rise to a painful sensa-
tion. In several instances, nevertheless, the motor nerves, though
insensible at their origin, show a certain degree of sensibility when
irritated after their exit from the skull, owing to fibres of com-
munication which they receive from the purely sensitive nerves.
In this respect they resemble the spinal nerves, the motor and
sensitive filaments of which are at first distinct in the anterior
and p<Mterior roots, but aderward mingle with each other, on
leaving the cavity of the spinal canal.

The three Mnntive nerves originating from the brain are the
large root of the fifth pair, the glossopharyngeal, and the pneumo-

■ HarTOoi StbUid of Rank pipieuB ; pabllshvd bj tlie Smithsonian Initltntioo.
\rMliliigton, 1853.

434

IB ORASflJ

Erves.

gnstric It will be observctl tbnt, in all their essential propcrticB,'
the J correspond witli the posterior roots of the spinal ner\-es. Uko j
them they are inexoitable, but extremely sensitive. Irritated ati
their polDt of origin, they give rise to acutely painful 8en^tioQ^
but to no convulsive movements. Secondly, if divide*! at the aame
situation, the operation is followed by loss of Acnsibility in the
parts to which they are distributed, without any disLurbance of the
motive power. Each of these nerves, furthermore, liko the posta-,
rior root of a spinal nerve, is provided with a ganglion througli
which its fibres pass: the fiMx pair, with the Casserian ganglion,
situated uear the inner extremity of the petrous portion of the tem-
poral bone; the glosso- pharyngeal, with the ganglion of Andersch,
situntoci in the jugular fos^^a; while the pnenmognstrte presents,
just before its passage through the jugular foramen, a ganglion
known as the ganglion of the pncumogastric nerve. Finally, the ■
aensitive fibres uf all these nerves, beyond the situation of their gao- f
glia, are intermingled with others of a motor origin. The large root
of the 6fth pair, which is exclusively sensitive, is accompanied by
the fibres of the small root, which are exclusively motor. The
glosso-pbaryngeal receives motor filaments from the facial and spi* ■
Dal accessory, becoming consequently a mixed nerve outside tbe
cranial cavity ; while the pneumugnsLric i» joined by fibres from the
spinal accessory and various other nerves of a motor character.
These nerves, accordingly, are exclusively sensitive only at their ^
point of origin, Though they afterwurd retain the predominating "
character of sensitive nerves, they are yet found, if irriUit«d In tbu
middle of their course, to be intermingled with motor Qbrcs, and
to have consequently acquired, to a certnin extent, the character of ■
mixed nerves. |

The resemblance, therefore, between the cranial and spinal nerves
is uompltite.

MoTOE Oc0Li CJoMMPNis. — This nerve, which is sometimes known
by the more convenient name of the ocuh-molariui, originates from
the inner edge of the crus cerebri, passes into the cavity of ihej
orbit by the sphenoidal fissure, and is distributed to the levator]
pnlpcbra; suporioris, and to all the muscles moving the eyeball,
except the external rectus and the superior oblique. Its irritation
accordingly produces convulsive movements in these parts, and
its division has the eQ'eci of paralyzing the muselcs to which it is

FIFTH PAIR. 4S5

diBtribnted. The superior eyelid falls down over the pupil, and
cannot be raised, owing to the inaction of its levator musole, so
tbat the eye appears oonstantly half shut This condition is known
by the name of "ptosis." The movements of the eyeball are also
nearly suspended, and permanent exteraal strabismus takes plac^
owing to the paralysis of the internal rectus muscle, while the ex-
ternal reotns, animated by a different nerve, preserves its activity.

Pathxticus. — This nerve, which supplies the superior oblique
musole of the eyeball, is similar in its general properties to the pre-
ceding. Its section causes paralysis of the above muscle, without
any loss of sensibility.

MoTOB ErmtNUS. — This nerve, the sixth pair, according to the
usual anatomical arrangement, is distributed to the external rectus
mnsole of the eyeball. Its division or injury by disease is followed
by internal strabismus, owing to the unopposed action of the internal
rectus mnacle.

Fifth Pair. — This is one of the most important and remarkable
in its properties of all the cranial nerves. It is the great sensitive
nerve of the face, and of the adjoining mucona membranes. Its
large root, after emerging from the outer and under surface of the
pons Varolii, passes forward over the inner extremity of the petrous
portion of the temporal bone. It there expands into a orescentic-
ahaped swelling, containing a quantity of gray matter with which
its fibres are intermingled, and which is known as the Oassertan
ganglion. The fibres of the smaller root, passing forward in com-
pany with the others, do not take any part in the formation of this
ganglion, but may be seen passing beneath it as a distinct bundle,
and continuing their course forward to the foramen ovale, through
which they emerge from the skull. In front of the anterior and
external border of the Gasserian ganglion, the fifth nerve separates
into three principal divisions, viz., the ophthalmic, the superior
maxillary, and the inferior maxillary. The first of these divisions,
-viz., the ophthalmic, is so called because it passes through the orbit
of the eye. It enters the sphenoidal fissure, and runs along the
npper portion of the orbit, sending branches to the ophthalmic gan-
glion of the sympathetic, to the lachrymal gland, the conjunctiva,
and the mucous membrane of the lachrymal sac. It also sends ofi'

483

TnK ORA?riAL NERVES.

R small br«ncli (nn
Bogea nnd supplies

tbe DMtl 1

Kg. 160.

branch) which penetrates i
Q Schneicierian mucous membrane, it then
emerges upon the Taco by the supra-orbiul foranmn, and is dtnri-
butcd to the integument of the forehead and side of the head u kr
back as the vertex.

Tbe second division of this nerve, or the auperior maxilUrr,—
passes out by the foramen rotundum, and runs along the litngrtO'^
dinal canal in ihc floor of the orbit, giving off brunches during it«
passage to the teeth of the upper jaw and to the mnoous membniK
of the antrum maxillare. It finally emerges upon the middle of the
face by the infra-orbital foramen, and is distributed to tbe ial«ga-
ment or ihe lower eyelid, noee, cheek, and upper lip.

The third, or inferior maxillary division of the 6flh pair, whick
is the largest of the three, leaves the cavity of the cranium by tSe

foramen ovale. It comprises a on-
sidcrablo portion of the large root
of tbe nerve, and all the fibres of
the small root. This divitioa is
therefore a mixed nerve, contaioia;
both motor and sensitive fibres,
while the two former are cxclo-
sively sensitive. It is distribaiaJ,
accordingly, both to maacles ind
to the sensitive surfaces. Soon afta
emerging from ibc fommen ovalf
it sends branches to tbe temporal
muBcle, to the masaeter^ the buoci-
nator, and to the internal and ex-
ternal pterygoids ; that is, to tlie
muscles which are particularly coe-
oemed in the movements of the
lower jaw. It also scndit sensitite
filaments to the integument of tbr
T^ernple, to that of a portion of the external ear and external ludi-
lory meatus. The third division of the fifth pair, then passinu
downward and forward, gives oft' a branch of considerable ««, tbe '
Hngiml branch, which is distributed to the maooas membrane of lbs j
anterior two-thirds of the tongue, and which also sends filaments to
the arches of the palate and to the mucous mernbmne of the cheek.
The remaining portion of tbe third diviaion, after giving a to*

Dtiminr-niis nF Piriii S titir.

Cr"» TUB PiC«.— O. r*«»lUo ||lin|))llll.

] llphibklmUdlrliloD. a. BnpvfWr biksU-
liirjrdJTUlon 9. InfarluraikslllKrjr dliUluj,.

FIFTH PATB. 4S7

branches to the mylo-hjoid muscle and to the anterior belly of the
digastric, then enters the inferior dental canal, sends filaments to
the teeth of the lower jaw, emerges at the mental forameo, and is
finally distributed to the integument of the chin, lower lip, and
infiirior part of the face.

This nerve is accordingly distributed to the sensitive aurfaces,
that ifl, the integument and mucous membranes about the face, and
to the muscles of maatioation. A few of its fibres are sent also to
the superQcial muscles of the face, such as the buccinator and the
orbicularis oris; but these fibres are sensitive in their character,
and serve merely to impart to the muscles a certain degree of
sensibility. It has been ascertained by Longet that if the various
branches of this nerve be irritated by a galvanic current, no con-
vulsive movements whatever are produced in those superficial
muscles of the face, which it supplies with filaments; but if its
smaller or non -ganglionic root be irritated in the same way, con-
tractiona instantly follow in the muscles of mastication.

The fifth pair is the most acutely sensitive nerve in the whole
body. Its irritation by mechanical means always causes intense
pain, and even though the animal be nearly unconscious from the
influence of ether, any severe injury to its large root is almost
invariably followed by cri«B which indicate the extreme sensibility
of its fibres.

If this nerve be completely divided, in the living animal, within
the cranium, at the situation of the Gasserian ganglion, the operation
is followed by total loss of sensibility in the skin of the face and in
the adjacent mucous' membranes. The conjunctiva, upon the afiected
side, is then completely insensible, and may be touched with the
point of a needle or the blade of a knife, without exciting any un-
easiness, and even without the consciousness of the animal. Probes
and needles may be passed into the nostril, and the lips or the
cheek may be pinched, pierced or cut, without exciting the least
sign of sensibility. The animal is entirely indifierent to all me-
chanical injuries upon the afiected side, though upon the opposite
side the parts retain their natural sensibility.

Owing to the paralysis of the lingual nerve, also, after this ope-
ration, the tongue, in its anterior two-thirds, becomes insensible to
ordinary irritations, and loses beside the power of taste.

Another peculiar efiect of the division of the fifth pair depends
upon the paralysis of its motor fibres, which are distributed, as we

438

THE CBANIAL NBRVES.

menll

have Been, to tbe mascles of mastication. Id m&uy of tbe lows
nnimals, conaequcnLly, ihe movomeiita of mastication beoonw ei-
ceedingly enfeebled upon the affected side. lo the cat, for example,
an animal in which mastication is usuallj very tborougbl; per
formed, this process becomes excessively laborious, so that the
animal aflcr this operation cannot maslicato solid meat, bnt reqoirv
to be fed with that which has already been cut in pieces.

The fifth pai r, beside supplying the acnsibiliiy of the intega
of the face, has a peculiar and important influence on the orgaas
special sense. This influence appears to consist in some oonnectioa
between the action of tbe fifth pair and tbe processes of nutrition;
80 that when the former is injured, the latter very bood beoome
deranged. For the perfect action of any one of the organs of
special sense, two conditions are necessary: first, the sensibilitv of
the special nerve belonging to it, and, secondly, the integrity of the
component parts of the organ itself. Now as the nutrition of ihe
organ is, to a certain extent, under the control of the fifth pair.uT
serious injury to this nerve produces a derangement in the tiissnes
of tbe organ, and consequently interferes with tbe due performaooe
of its function.

The mucous membrane of the nasal passages, for example, i>
supplied by two different nerves; fi.rs», the olfactory, distributed
throughout its upper portion, by which it is endowed with tbe
special sense of smell ; and, secondly, tbe nasal branch of the Btik
pair, distributed throughout its middle and lower portions, I7
which it is supplied with ordinary sensibility.

Since the fiflh pair, accordingly, supplies general sensibility to
the nasal passages, this property will remain after tho special aaix
of smell has been destroyed. If, however, the fifth pair ilseU hr
divided, not only is general sensibility destroyed in the Scbnmderi«n
mucous membrane, but a disturbance begins to take plaoe in IIk
nutrition of its tissue, by which it is gradually rendered un6t for
the perforoiancQ of its special function, and the power of smell is
finally lost. The mucous membrane, under theae circumstaocai,
becomes injected and swollen, and the nasal passage is obetnicwd
by an accumulation of puriform mucus. According to Longet, tin
raucous membrane also assumes a fungous consistency, and is liable
to bleed at the slightest touch. The effect of this alteration is to
blunt or altogether destroy the sense of amell. It is owing to a
similar unnatural condition of the mucous membrane that tbe pow

FIFTH FAIB. 439

of smell is always more or less impaired in cases of coryza and
ioflaenza. Tbe olfactory- nerves become inactive in consequence
of tbe morbid alteration in tbeir mucous membrane, and in tbe
secretions which cover it

The influence of this nerve over tbe organ of vision is still more
remarkable. It has been known for many years that division of
the fifth pair within tbe cranium, or of its ophthalmic branch, is fol-
lowed by an inflammation of the corresponding eye which usually
goes on to complete and permanent destruction of tbe organ.
Immediately after the operation, tbe pupil becomes contracted and
tbe conjunctiva loses its sensibility. At the end of twenty-four
hoars, the cornea begins to become opaline, and by the second
day the conjunctiva is already inflamed and begins to discbarge a
paralent secretion. The inflammation, after commencing in tbe
conjunctiva, increases in intensity and soon spreads to tbe iris,
which becomes covered with a layer of inflammatory exudation.
Tbe cornea grows constantly more opaque, until it is at last
altogether impermeable to light, and vision is consequently sua-
ipended. Blindness, therefore, does not result in these instances
from any direct affection of the optic nerve or of tbe retina, but is
owing simply to opacity of tbe cornea. Sometimes the diseased
action goes on until it results in ulceration of the cornea and dis-
cbarge of the humors of the eye; sometimes, after the lapse of
several days, the inflammatory appearances subside, and the eye is
finally restored to its natural condition.

It has been observed, however, that, although the above conse-
quences always follow division of tbe fifth pair, when performed at
the level of tbe Caaseriao ganglion, or between it and tbe eyeball,
they are either much diminished in intensity or altogether wanting
when the division is made at a point posterior to the ganglion.
This circumstance has led to tbe belief that the influence of tbe fifth
pair on the nutrition of tbe eyeball does not reside in its own proper
fibres, but in some filaments of the sympathetic nerve which join
tbe fifth pair at the level of the Casserian ganglion. If the section
accordingly be made at this point, or in front of it, tbe fibres of the
sympathetic will be divided with tbe others, and inflammation of
the eye will result; but if tbe section be made behind the ganglion,
the fibres of tbe sympathetic will escape division, and tbe injurious
effects upon the eye will bo wanting. Such is tbe explanation
usually given of tbe above-mentioned facts ; but tbe question has
not as yet been determined in a positive manner.

440

lL kbstks.

DiTision of tbe fifth pnir deatrojra also the genera! sensibility of
the external auHitorjr mcsatus, the lining membrane of which ia
supplied by its Glanients. In^nmmation of this membrane and its
consequent alterations, it is well known, interfere seriously with
the sense of hearing. It ia no uncommon oucurrcnco for an accu-
mulation of cerumen to take place nfter inflummation of this part,
so as to block up the auditory canal and produce partial or com-
plete deafness. It has not been ascertained, however, whether
division of the fifth pair is usuuUy luUowed by similar changes in
this part.

The lingual branch of the flflh pair supplies the anterior ex-
tremity and middle portion of the tongue both with general sensi-
bility and with the power of taste. The sensibility of the tongue
is accordingly provided for by two difterent nerves; in its anterior
two-thirds, by the lingual braituh of the llfih pair; in its posterior
third, by the fibres of the glosso-pboryngeal.

The facial branches of the fifth pair are the ordinary seat of lie
douloureux. This affection is not ODfrequently conQned to either
the supra-orbital, the infra-orbital, or the mental branch; and the
pain may be accurately traced in the direction of their diverging
fibres. It has already been mentioned that the painful sensations
sometimes alao follow ihe course of the facial, owing to some sensi-
tive Glanients which that nerve receives from the tiflh pair.

Facial. — This nerve was known to the older anatomisla as the
"portio dura of the seventh pair." It leaves the cavity of the
cranium by the internal auditory foramen, in company with the
auditory nerve; and, as the Utter ia of a suffer consistency thou the
former, they have received the names respectively of the ** porlio
mollis" and *'[K>rlio dura" of the seventh pair. There is, however,
no physiological connection between these two nerves; for while
the auditory ia spread out in the cavity of the internal ear, the facial
passes onward through the petrous portion of the temporal bone,
emcr^(;a at the stylo-mastoid foramen, bends round beneath the
external ear, and ptiSHus forward througli the substance of the
parotid gland, forming a plexus, called the "pes anserinus," by the
abundant inosculation of its different branches. It then sends its
filaments forward in a diverging course, and is finatly distributed
to the muscles of the external cor, to the frontalis and superciliaria
muscles, to the orbicularis oculi, the compressors and dilators of
the nares, the orbicularis oris, and to the elevators and deprcsaurs

I
I
I

TACIAL NERTK.

?ig. 151.

VAeiAi. ViKTi.

of the lipe; lliat is, to the superficial musctes or the face, which are
coDcerned in the prodaction of expression. (Fig. 161.)

The facial, conseqaently, is the
tor nerve of the face. It bcui
nothing to do with traiifimiLting
sensitive impressiona, since it hns
been frequently shown that afler
section of the QflU pair, the faciul
reuuiaiDg entire, the sensibility of
the &ce is completely lost; so that
the integument may be cut, pricked,
pierced, or lacerated, without any
sign of pain being exhibited by the
animal. The facial, therefore, dues
not transmit sensation from these
parts; aud its division, which was
r&rmerly resorted lo in cases of
lie douloureux, is accordingly alto-
gether incapable of relieving nenralgic pains.

This nerve, however, is directly connected with muscular action,
since mechanical or galvanic irritation of its 6brea produces ooa-
vulsivo twitching in the cars, nostrils, lips and cheeks.

If the facial nerve be divided in one of the lower nnimnla, on, for
example, in the cat, immediately after its emergence from the
stylo-mastoid foramen, it will be found that complete muscular
paralysis has occurreil in all those parts t*^ which the nerve is dis*
tributed, while ihe power of sensation remains unimpaired. The
animal is incapable of moving the car, which remains constantly in
the same position. There is also incapacity of closing the eyelids,
owing to paralysis of the orbicularis oculi, and the eye accordingly
remains constantly open, even when the opposite) eye is closed;
as during sleep, or in the act of winking. If the conjunctiva be
touohcd, the animal fecl.4 the irritation, and endeavor^ to escape
from it; but the eyeball is only drawn partially backward into the
socket by the action of the recti muscles, and the third eyelid
pushed partly across the cornea. The cotnploio cloanro of the eye
is impossible. It will be observed, accordingly, that precisely oppo*
site eftects are produced upon the eyeli<lB by paralysis of the ouulo-
motorius nerve, and by that of the facial. In the fonnur instance,
owing to the paralysis of the levator pulpebne superioris, the eve
is always partially closed ; in the latter, owing to paralysis of thv

E42

THE CRAKIAL NEKVES,

orbicularis, it Is always partUlJy open. The moveinenta of tbe
tiarcs are atso suspended on the side oF the injury, nod if the angle
of the :noulh Iw examined ou that aide, it will be found to hang
dowQ lower than on the opposite side, and to be constantly partly
open, owing to the parnlysis of the orbicularis oris and the eleva-
tors of the angle of the mouth.

These are the only inconveniences which follow the diviaion of
the facial nerve in the cat, but in some otlier of the lower animals,
where vahouii muscalar organs iq this region are particularly de-
velopod, the oonsef|uouce8 are tnore trnubleaome. Thus, in the rabbit,
the ear, upon the aifected aide, falls down, and cannot be raised or
pointed in different directions; and as the movements of the ear
are ioiportuut in tbetie animals, as aids to the bearing, the per-
fection of this sense must be considerably impaired by paralysis of
the facial nerve, In the horse, it has been noticed by Bernard,'
that division of the facial on both sides is fatal by suiTocation. For
this animal breathes exclusively through the nostrils, which open
widely at the Liinu of iuitpiratiori, to allow the a^lrnissioD of air. If
these movemonla be suspended, by paralysis of the facial nerve, the
nmtrils immediately collapse, and the animal dies by suffocation.

In the human subJMt, the facial nerve is occasionally paralyzed
upon one side, sometimes from sympathetic irritation, sometimea
ffoin organic disease in the potrouit portion of the temporal bone,
or within the cranial cavity near the origin of the nerve. In either
case, an extremely well-marked affection is the result, known as
"faotal paralysis.'* This condition is chiefly characterized by an
entire absence of expression on the alYected side of the face. The
lower eyelid sinks downward, from paralysis of the orbicalarii
muscle, and cannot be closed.

The comer of the mouth also falls downward, and the whole
lower part of the face ia drawn orer to the opposite side by the
force of the antagonistic muscles. The lips are unable to retain
the fluids of the mouth ; and the saliva dribbles away from between
tbem, giving to the face a remarkably vacant and helpless appear-
ance.

The principal inconvenience, however, suffered by the human
subject in facial paralysis, depends upon the want of action of ihe M
muscles about the lips and cheek. In drinking, the fluids escope

■ L«QOB8 >nr 1b I'hjnMogit et In pAtliologie da 6jr«Uia« Nvrveux, Pario, 1838,
vol. il. p. 36.

OLOSSO-PHABYirOEAL NEBTE. 448

by the comer of the month, and io mastication the food has partly
a tendenoy to escape by the same opening, and partly accumulates,
on the a£focted side, between the gums and the cheek, owing to the
paralysis of the buccinator muscle, which reoeires its motor fila-
mentB from the fooial nerve. Thus, the action of all the superficial
facial muscles is suspended, the expression of the face is destroyed,
and the movementB of the lips and the prehension of the food
seriously interfered with.

Though the facial, however, be essentially a motor nerve, yet its
principal branches distributed to the face have a certain degree of
sensibility ; that is, when these branches are irritated in the middle
of their course, the animal immediately gives evidence of a painful
sensation. Longet has shown, by an extremely ingenious mode
of experiment,' that this sensibility of the branches of the facial
does not depend on any sensitive fibres of their own, but upon
those which they derive /n?Tn inosculation ivith the JifO^ pair. He
exposes, for example, the facial nerve in the dog, and, irritating Its
principal branches one after the other, at each application of the
irritant there are evident signs of pain. He then divides the facial
nerve at its point of exit from the stylo-raastoid foramen, and
finds that, after this operation, the sensibility of its branches still
remains. The fibres, accordingly, upon which this sensibility
depends, do not pass out with the trunk of the nerve, but are
derived from some other source. The experimenter, then, upon
another animal, divides the fiflh pair within the skull, leaving the
&cial untouched; and afterward, on irritating as before the ex-
posed branches of the latter nerve, he finds that its sensibility has
entirely disappeared. It is by filaments, accordingly, derived from
the fifth pair, that a certain degree of sensibility is communicated
to the branches of the facial

These facts account for the peculiar circumstance that, in cases
of tic douloureux, the spasmodic pain sometimes follows exactly
the course of the facial nerve, viz; from behind the ear forward
upon the side of the face ; and yet the section of this nerve does not
put an end to the neuralgia, but only causes paralysis of the facial
muscles.

Olosso-Phabyvoeal. — This nerve originates from the lateral
portion of the medulla oblongata, passes outward, and enters the

> Traits do Phjiiologie, vol. 11. pp. 354-357.

THE CRAXIAl ICERVKS.

posterior foramen Incorum in oompany with the pncumogastric ond
spinal accessory. While in the jugular ibssa it presents a gangliform
enlargement, culled the gntiglion of Attderscb, below the level of
which it receive branchea of communication from the facial and
the spinal accessory. It then runs downward and forward, and is
distributed to the mucous membrane of the base of the tongue,
pillars of the f&ace», suft palate, middle ear, and upper part of the
pharynx. Jt also seuda some branches to the coustrictors of the
pharynx and the neighboring muscles, Longet has foond this
nerve at its origin to be exclusively nensitive ; but below the lercl
of its ganglion it has been found by liim, as well as by varioos
olbcr observers, to be both sensitive and motor, owing to the fibres
of communication received from the motor nerves mentioned above.
Its final dislributioD ia, however, as we have seen, principally to
ttenBitivo surfaces. Thu principal olDce of this nerve is to impart
the suiiBc of taste to the posterior third of the tongue, to which it is
distributed. It also presides over the goneral sensibility of this
part of the tongue, as well as that of the fauces and pharynx.

Dr. John Kcid,' who has performed a great variety of experiments
upon this nerve, cotncs to the following conclusions in regard to it.
First, that it is essentially a sen.sitive nerve, since there are unequi*
vocal signs of paiu when it is pricked, pinched, or cut. Second,
that irritation of this nerve produces convulsive movements of ibe
throat and lower part of the face; but that these movements are, in
great measure, not direct, but reflex in their character, since they
will take place equally well after the glossopharyngeal has been
divided, if the irritation be applied to its cranial extremity. Third,
that this nervo supplies the special sensibility of tasie to a portion
of the tongue; but that it is not the excdtsUe nerve of this sense,
since the power of taste remains, after it has been divided on both
sides.

There are certain reflex actions, furthermore, which take place
through the medium of the glosso- pharyngeal nerve. After the
food has been thoroughly masticated, it is carried, by the move-
roenls of the tongue and sides of the mouth, through the fauces,
and brought in contact with the muciius membrane of the pharynx.
This produces an impression which, conveyed to the medulla
oblongata by the QIaiuents of the glosso-pbaryngeal, excites the

* III Todd's Cjcloptedto, of Aitmtam^ itn<l PlijRiolo^, artiuU C/oaM^/iAaryoym/
iVorvr.

PNEUU0GA8TRTC NERTS. 446

mascles of tbe f&oeea and pharynx by reflex action. The food is
OODseqQently grasped by these muscles, without the concurrence of
the will, and the process of deglutition is commenced. This action
is not only involuntary, but it will frequently take place even in
opposition to the will. The food, once past the isthmus of the fauces,
is beyond the control of volition, and cannot be returned except by
ooDVuIsive action, equally involuntary in its character.

Natural stimulants, therefore, applied to the mucous membrane
of the pharynx, excite deglutition; unnatural stimalauts, applied
to the same part, excite vomiting. If the finger be introduced into
tbe fiinces and pharynx, or if the mucous membrane of these parts
be irritated by prolonged tickling with the end of a feather, the
sensation of uausea, couveyed through the glosso- pharyngeal nerve,
is sometimes so great as to produce immediate and copious vomit-
ing. This method may oflen be successfully employed in cases of
poisoning, when it is desirable to excite vomiting rapidly, and when
emetic medicines are not at hand.

Frkuiiooabtbic. — Owing to the numerous connections of the
pnenmogsstric with other nerves, its varied and extensive distribu-
tion, and the important character of its functions, this is properly
regarded as one of the most remarkable nerves in the whole body.
Owing to the wandering course of its fibres, which are distributed
to no less than four different vital organs, viz., the heart, lungs,
stomach and liver, as well as to several other parts of secondary
importance, it has been often known by the name of the par vagum.
Tbe pneumogastric arises, by a number of separate filaments, from
the lateral portion of the medulla oblongata, in the groove between
the olivary and restiform bodies. These filaments unite into a
single trunk, which emerges from the cranium by the jugular fora-
men, where it is provided with a longitudinal ganglionic swelling,
the "ganglion of the pneumogastric nerve." Immediately below
the level of this ganglion the nerve receives an important branch
of communication from the spinal accessory, and afterward from
the facial, the hypoglossal, and the anterior branches of the first
and second cervicals.

At its origin, the pneumogastric is exclusively a sensitive nerve.
Irritated above the situation of its ganglion, it has been found to
convey painful sensations alone: but if the irritation be applied at
a lower level, it causes at the same time muscular contractions,
owing to the filaments which it has received from the abuvc-men-

440

THB CRAKTAL NERVES.

FiL-, 1.'.2.

r'^r

tinned motor nerves. It becomes, consequently, after emerging
from the cranial cavity, a mixed nerve; and has accordingly, in

nearly all its branches, a double distribu-
tion, vis., to the mucous membranes and
the moscular coat of the organs to which
it belongs.

The ordinary sensibility of the pneu-
Tnogastric nerve, however, as all experi-
menters have observed, is exceediogly
dull, in comparisoo with that of the other
soewitive cranial nerves. We have often
divided this nerve in the middle of the
neck, without any distinct manifestatioD
uf pain being given by the animal; and
though Bernard has found tbnt at some
limes its sensibility is well marked, while
lit others it is very indistinct, he is not
ftble to soy upon what special physio-
logical coQditloDs thiiidiQerence depends.
While the ptieumogastrlo, however, it
decidcflly deficient, as a general role, in
ordinary sensibility, it possesses, as we
shall see hereafter, n sensibility of a pecu-
liar kind, wliieb is oxceedin^y important
for the maintenance of the vital func-
tions.

In passing down the neck, this nerve
rands braiiubes to the mucous membraae
and muBculur coat of the pharynx, caso-
phagus,and respiratory passages. Among
ihe most important of these branches are
the two laryngeal nerves, viz., the supe-
rior and inferior. The superior laryngoal
nerve, which is given off from the trunk
of the pneiimognstric Just al\er it has emerged from the cavity of the
skull, passes downwnrd and forward, penetrates the larynx by an
opening in the side of the thyro-hyotd membrane, and is distributed
to the mucous membrane of the larynx and glottis, and also to b
single laryngeal rauscte, viz., the erico-thyrold. This branch is
therefore partly muscular, but mostly sensitive in its distribution.
The inferior laryngeal brunch is given off just after the pneumo-

nin^mm at PaiiliK<i4i«aTat<T
Vliiivt.«'lihlup<1ucii»Jbrui«li««.
—I. Plturjn^ftl liraneli. 'i Piu|in-
rlor luT/iiKaiil. X tnrnrlor tityu.
gMkl. 4. riilgn»fi4r]r lntti<tLu*. ft.
Sluniacli. <(. LWsi.

PNECHOGASTBIC HSBTE. 447

gastric has entered the cavity of tbe chest. It carves roand the
sabclaviaa artery on the right side and the arch of the aorta on
tbe left, and ascends in the groove between the trachea and oeso-
phagns, to the larynx. It then enters the larynx between the
cricoid cartilage and the posterior edge of the thyroid, and is dis-
tributed to all the moscles of the larynx, with the exception of the
crico-thyroid. This branch is, therefore, exclosively muscular in
its distribution.

The trunk of the pneumogastric, afler supplying tbe above
branches, as well as sending numerous filaments to the trachea
and cesopbaguB in the neck, gives off in the cbeet its pulmonary
branches, which follow the bronchial tubes in the lungs to their
minutest ramifications. It then passes into the abdomen and sup-
plies the muscular and mucous layers of the stomach, ramifying
over both the anterior and posterior surfaces of the organ ; afWr
which its fibres spread out and are distributed to the liver, spleen,
pancreas, and gall-bladder.

Tbe functions of the pneumogastric will now be successively
studied in the various organs to which it is distributed.

Pharynx and (Eaoj^aguB. — The reflex action of deglutition, which
has already been described as commencing in the upper part of the
pharynx, by means of the glosso-pharyngeal, is continued in the
lower portion of the pharynx and throughout the oesophagus by
the aid of the pneumogastric. As the food is compressed by the
superior constrictor muscle of the pharynx and forced downward, it
excites the mucous membrane with which it is brought in contact
and gives rise to another contraction of the middle conBtriclor. The
lower constrictor is then brought into action in its turn in a similar
manner; and a wave-like or peristaltic contraction is thence pro-
pagated throughout the entire length of the oesophagus, by which
the food is carried rapidly from above downward, and conducted at
last to the stomach. Each successive portion of tbe mucous mem-
brane, in this instance, receives in turn the stimulus of the food,
and excites instantly its own muscles to contraction; so that the
food passes rapidly from one end of the oesophagus to the other, by
an action which is wholly reflex in character and entirely withdrawn
from the control of the will. Section of tbe pneumogastric, or of
its pharyngeal and casopbageal branches, destroys therefore at the
same time the sensibility and the motive power of these parta. The
food is no longer conveyed readily to the stomach, but accumulates
in the paralyzed oesophagus, into which it is forced by the voluntary

TRK CRAXIAL NBBVBS.

movementfi of the mouth ami fauces, and by the continuerl actjon
of the upper pnrt of the pharynx.

It m«st be remembered that the general sensibility of the asso-
phagua is very slight, as compared with that of the iniegument, or
even of the mucous membranes near the exterior. It is a general
rule, in fact, that the sensibility of the mucoua membranca is mort
acute at the external oriBccs of their canals ; as, for example, at tbe
lips, anterior nares, anus, orifice of the urethra, &c It diminishes
constantly from without inward, and disappears altogether at a
certain distance from the surface. The sensibility of the pharynx
is tesi; acute tlian that of the mouth, but is still sufllcient to enable
us to perceive the contact of ordinary substances; white in the
ccsophagus we are not usually sensible of the impression of the food
as it passes from above downward. The reflex actloQ takes place
here without any assistance from the consoiousness; and it is only
when substances of an unusually pungent or irritating nature arc
mingled with the food, that its passage through the cesophagus pro-
duces a distinct sensation.

Larynx. — We have hlready described the course and distribution
of the two laryngeal branches of the pneumogastric The superior
laryngeal nerve is principally the sensitive nerve of the larynx.
Its division destroys sensibility in the mucous membrane of this
organ, but paralyzes only one of its muscles, viz : the crico- thyroid.
Galvanisation of this nerve has also been found to induce cod-
traciions in the cricothyroid, but in none of the other masclcs
belonging to the hirynx. The inferior laryngeal, on the other
hand, is a motor nerve. Its division paralyzes all the muscles of
the larynx except the crico-thyroid; and irritation of its divided
extremity produces contraction in the same muscles. The mnscles
and mucous membrane of the larynx are therefore supplied by two
different branches of the same trunk, viz., the 8U]>erior laryngeal
nerve for the mucous membrane, and the inferior laryngeal nerve
for the muscles.

The larynx, in man and in nil the higher animals, performs a
double function; one part of which is connected with the voice, the
other with respiration.

The furmatioD of the voice in the larynx takes place as follows.
If the glottis be exposed in the living animal, by opening the
pharynx and cesophagus on one aide, and turning the larynx for-
ward, it will bo seen that so long as the vocal chonls proaerve
their usual relaxed condition during expiration, no sound is huanl,

PVKUHOGASTBIO 17EBVB. 449

except the ordinarj faint whisper of the air passing gently through
the caritj of the larynx. When a vocal sound, however, is to be
produced, the chords are suddenly made tense and applied closely
to eaob other, so as to diminish very considerably the size of the
orifioe; and the air, driven by an unusually forcible expiration
through the narrow opening of the glottis, in passing between the
vibrating vocal chords, is itself thrown into vibrations which pro-
dtioe the sound required. The tone, pitch, and intensity of this
sound, vary with the conformation of the larynx, the degree of ten-
sion and approximation of the vocal chords, and the force of the
expiratory effort. The narrower the opening of the glottis, and the
greater the tension of the chords, under ordinary circumstances, the
more acute the sound; while a wider opening and a less degree of
tension produce a graver note. The quality of the sound is also
modified by the length of the column of air inoluded between the
glottis aad the month, the tense or relaxed condition of the walls
of the pharynx and fauces, and the state of dryness or moisture of
the mucous membrane lining the aerial passages.

Articnlation, on the other hand, or the division of the vocal sound
into vowels and consonants, is accomplished entirely by the lips,
tongue, teeth, and fauces. These organs, however, are under the
control of other nerves, and the mechanism of their action need not
oocnpy us here. -

Since the production of a vocal sound, therefore, depends upon
the tension and position of the vocal chords, as determined by the
action of the laryngeal muscles, it is not surprising that division of
the inferior laryngeal nerves, by paralyzing these muscles, should
produce a loss of voice. It has been sometimes found that in very
young animals the crico-thyroid muscles, which are the only ones
not affected by division of the inferior laryngeal nerves, are still
sufficient to give some degree of tension to the vocal chords, and
to produce in this way an imperfect sound ; but usually the voice
is entirely lost after such an operation.

It is a very remarkable fact, however, in this connection, that all
the motor filaments of the pneumogastric, which are concerned in
the formation of the voice, are derived from a single source. It
will be remembered that the pneumogastric, itself originally a
sensitive nerve, receives motor filaments, on leaving the cranial
cavity, from no less than five different nerves. Of these filaments,
however, those coming from the spinal accessory are the only ones
necessary to the production of vocal sounds. For it has been found
29

450

THB CRANIAL NBRTKB.

by Biachoff and by Beroard' that if all the roota of the spinal acc«-
aory be divided at their origin, or if the nerve itself be torn away
at its exit from the akuU, all the oilier cranial nerves remaiaiog
untouched, the voice is lost as completely as if the inferior laryn-
geal itself hod been destroyed. All the motor (Ibreii of the pneu-
mogastric, therefore, which act in the formation of the voice are
derived, by inoaculation, from the spinal accessory nerve.

In respiration, again, the larynx [lerforms another and still more
important function. In the first place, it stonds as a sort of guard,
or sentinel, fit the entrance of the respiratory passages, to prevent
the intrusion of foreign substances. If a crura of bread accidentally
fall within the aryteno-epiglottidean folds, or upon the edges of the
vocal chorda, or upon the posterior surface of the epiglottis, tb«
sensibility of these parts immediately excites a violent expulsive
cough, by which the foreign body is dislo<1ged. The impreesiou,
received and convoyud inward by tlie sensitive fibres of the auperior
laryngeal nerve, is reflected back upon the expiratory muscles
of the chest and abdomen, by which the instinctive movements of
coughing are accurnplinhcd. Touching the above parts with the
point of a needle, or pinching them with the blades of a forceps,
will produce the same effect. This reaction is essentially dependent
on the sensibility of the laryngeal mucous membrane; and it can
no longer be produced after section of the pneumogastric nerve, or
of its superior laryngeal branch.

In the second place, the respiratory rnovenients of the tfhtttB, already
described in a previous chapter, are uf the greatest importance to
the preservation of life. We have seen that at the moment of
inspiration the vocal chords are separated from each other, and the
glottis opened, by the action of the posterior crico- arytenoid muscles;
and that in expiration Che muscles and the vocal chords are both
relaxed, and the air allowed to pass out readily through the glottis.
The opening of the glottis in inspiration, therefore, ia an active
movement, while its partial closure or collapse in expiration is a
passive one. Furthermore, the opening of the glottis in iuspirattou
is necessary in ortlcr to afford a suf&ciently wide passage fur the
air, in its way to the trachea, bronchi, and pulmonary vesicles.

Now we have found, as I3udge and Longet bad previously no-
tice<l, Lliat if the inferior laryngeal nerve on the right side be
divided while the glottis is exposed as above, the respiratory move-

Siichenlus ExpC-rlmunUlra sar Ira fonatlona du n^rf Bptnal. P«rU, Ift&l.

PieKCHOGASTBIC XXBVK. 46t

merits of tlie right vocal chord instantly cease, owing to the para-
lysis of the posterior crico-arytenoid muscle on that side. IP the
inferior huyngeal nerve on the left side be also divided, the para-
lysis of the glottis is then complete, and its respiratory movements
cease alk^ether. A serious difficulty in respiration is the imme*
diata eonseqnence of this operation. For the vocal chords, being
no longer stretched and separated from each other at the moment of
inspiration, but remaining lax and flexible, act as a double valve,
and are pressed inward by the column of inspired air; thus par-
tially blocking up the passage and impeding tbe access of air to
the lungs. If tbe pneumogastrics be divided in the middle of the
neck, the larynx is of course paralyzed precisely as after section
of tbe inferior laiyngeal nerves, since these nerves are given off
(mly after the main trunks have entered the cavity of the chest.
The immediate effect of either of these operations is to produce
a difficulty of inspiration, accompanied by a peculiar wheezing or
meking noise, evidently produced in the larynx and dependent on
the falling together of Uie vocal chords. In very young animals,
as, for example, in pupa a few days old, in whom the glottis is
smaller and the larynx less rigid than in adult dogs, this difficulty
is much more strongly marked. Legallois* has even seen a pup
two days old almost instantly suffocated after section of the two
inferior laryngeal nerves. We have found that, in pups two
weeks old, division of the inferior laryngeals is followed by death
at tbe end of from thirty to forty hours, evidently from impeded
nspiratton.

The importance, therefore, of these movements of the glottis in
respiration becomes very evident They are, in fact, part and
parcel of the general respiratory movements, and are necessary to
a doe performance of the function. It has been found, moreover,
that the motor filaments concerned in this action are not derived,
like those of the voice, from a single source. While the vocal
movements of the larynx are arrested, as mentioned above, by
division of the spinal accessory alone, those of respiration still go
<Hi ; and in order to put a stop to tlie latter, either the pneumo-
gastrics themselves must be divided, or all five of tbe motor nerves
from which their accessory filaments are derived. This fact Has
been noticed by Longet as showing that nature multiplies the safe-
guards of a function in proportion to its importance; for while tbe

■ In LoDgtt'B TniU de Plijr«iologiw, vol. li. p. 3S4.

462

THB CHAI7IAT. XBRTES.

spinal accessory, or any other one of the above-mentioned nerves,
might be aflected liy local accident or disease, it would be very
improbable that any single injury should paralyze simultaneously
tbe spinal accessory, the facial, the hypogloesal, and the iirat and
second cervicals. The respiratory movements of the larynx are
QODsecjaently much more thoroughly protected than those which
are merely concerned in the formatioo of the voice.

Lungs.' — The influence of the pneumogndtrio upon the function
of the lunga is exceedingly important. The nerve acts here, as in
most other organs to which it ia distributed, in a double or mixed
capaoity ; but it is principally as the sensitive nerve of the lungs
that it has thus far received attention. It is this nerve which
conveys from the lungs to the medulla oblongata that peculiar
impression, termed btsoin de rtspirvr, which excites by reflex nctioD
the diaphragm and intercostal muscles, and keeps up the play of
the respiratory movements. As we have already shown, this action
is an involuntary one, and will even take place when conscioasneii
is entirely suspended. It may indeed be arrested for a time by an
eflbrt of the will; but the impression conveyed to the medulla soon
becomes so strong, and the stimulus to inspiration so urgent, that
they can no longer be resisted, and the muscles contract in spite of
our attempts to restrain them.

A very remarkable effect is accordingly produced on respiration
by simultaneoua division of both pnoumogaF^tric nerves. This
experiment is best performed on adult dogs, which may bo ether-
ized, and the norvca exposed while the animal is in a coaditioo of
insensibility, avoiding, in this way, the disturbance of respiratioo,
which would follow if the dissection were performed while the ani-
mal was conscious and sensible to pain. After the effects of the
etherization have entirely passed oi^', and respiration and circulation
have both rcturnod to a quiescent condition, the two nerves, which
have been previously exposed and secured by a loose ligature, may
be instantaneously divided, and the effects of the operatioo readily
appreciated.

Immediately after the division of the nerves, when performed in
the above manner, the respiration is hurried and difficult, owing to
the sudden parolysia of the larynx and partial closure of the glottis
by the vocal chorda, as already described. This condition, how-
ever, is of short continuance. In a few moments, the difficulty of
breathing and the general agitation subside, the animal becomes
perfectly quiet, and the only remaining visible effect of the opera-

FHEUHOOASTBIO yKBVX. 458

tion 18 a dCmimahed Jrequency m the movements of respiration. This
diminution is frequently strongly marked from the first, the n amber
of respirations &lling at once to ten or fifteen per minate, and be-
ooming, in an hour or two, still farther reduced. The respirations
are performed easily and quietly; and the animal, if left undisturbed,
remains nsoally crouched in a corner, without giving any special
signs of discomfort If he be aroused and compelled to move
about, the frequency of the respiration is temporarily augmented ;
but as soon as he is again quiet, it returns to its former standard.
By the second or third day, the number of respirations is often
reduced to five, four, or even three per minute; when this is the
case, the animal usually appears very sluggish, and is roused with
difficulty from his inactive condition. At this time, the respiration
is not only diminished in frequency, but is also performed iu a
peculiar manner. The movement of inspiration is slow, easy, and
silent, ocoDpying several seconds in its accomplishment; expiration,
<Hi the contrary, is sudden and audible, and is accompanied by a well
marked expulsive effort, which has the appearance of being, to a
certain extent, voluntary in character. The intercostal spaces also
sink inward during the lifting of the ribs; and the whole movement
of respiration has an appearance of insufficiency, as if the lungs
were not thoroughly filled with air. This insufficiency of respira-
tion is undoubtedly owing to a peculiar alteration in the pulmonary
texture, which has by this time already commenced.

Death takes place at a period varying from one to six days after
the operation, according to the age and strength of the animal.
The only symptoms accompanying it are a steady failure of the
respiration, with increased sluggishness and indisposition to be
aronsed. There are no convulsions, nor any evidences of pain.
Aiter death, the lungs are found in a peculiar state of solidification,
which is almost exclusively a consequence of this operation, and
which is entirely different from ordinary inflammatory hepatization.
They are not swollen, but rather smaller than natural. They are
of a dark purple color, leathery and resisting to the feel, destitute
of crepitation, and infiltrated with blood. Pieces of the lung cut
out sink in water. The pleural surfaces, at the same time, are bright
and polished, and their cavity contains no effusion or exudation.
The lungs, in a word, are simply engorged with blood and empty
of air; their tissue having undergone no other alteration.

These changes are not generally uniform over both lungs. The
organs are usually mottled on their exterior; the variations in color

454

TDK CRANIAL NERVES.

corresponding with the dilTerent degrees of alteration exhibited by
different parts.

The explnnation usually adopted of the abore consequenoes fol<
lowing division of the pneiimogastrics is as follows: The oerves
being divided, the impresaion which originates in the lungs frooi
the accumulation of carbonic acid, and which is destined to excite
the respiratory movements by reflex action, can no longer be tntns*
mitted to the medulla oblongata. The natural litimulus to respire-
tion being wauling, it is, accordingly, less perfectly performed. Tbei
respiratory movements diminish in frequency, and, growing con-'
tinually slower and slower, finally cease altogether, and death is
the result. ^

The above explanation, however, is not altogether sufficient. It V
accounts very well for the diminished frequency of respiration, but
not for its partial continuance. For if iho pneumogastric nerves
be really the channel through which the stimulus to respiration ts
conveyed to tho medulla, the difTiculty is not to understand why
respiration should be retarded al\er division of these nerves, bat
why it ohould continue at all. In point of fact, the respiratory
movements, though diminished in frequency, continue often for
some days after this operation. This canuot be owing to force of
habit, or to any remains of nervous influence, as has been some-
limes suggested, since, when the medulla itself is destroyed, respira-
tioo, as we know, stops instantaneously, and no attempt at move* ■
ment is made after the action of the nervous centre is suspeoded.

It is evident, therefore, that the pneumogastric nerve, though the
chief agent by which the respiratory stimulus is convcyml to the
medulla, is not the only one. The lungs are undoubtedly the
organs which are most sensitive to an accuraulation of carbonic
acid, and nn imperfect arterialization of the blood; and the sensa-
tion which results from such an accumulation is accordingly first
felt in ihem. There is reason to believe, however, that all the vas-
cular organs are more or less capable of originating this impression,
and that alt the sensitive nerves are capable, to some extent, of trans-
mitting it. Although the first disagreeable sensation, on holding
the breath, makes itself felt in the lungs, yet, if we persist in sus*
pending the respiration, we soon become conscious that the feeling
of discomfort spreads to other parts ; and at last, when tfae accu-
malation of carbonic acid and the impurity of the blood have
become excessive, all parts of the body sufler alike, and are per-
vaded by a general feeling of derangement and distress. It is easy,

PNEUHOGASTBIO NBHrX. 456

therefore, to anderatand whj Tespiratioa should be retarded, afWr
eectioD of the pDeumogastrics, since the chief source of the stimulus
to respiration is cut off; but the moremeDts still go on, though more
slowly than before, because the other sensitive nerves, which con-
tintie to act, are also capable, in an imperfect manner, of conveying
the same impression.

The immediate cause of death, after this operation, is no doubt
the altered condition of the lungs. These organs are evidently
very imperfectly filled with air, for some time previous to death;
and their condition, as shown in poat-mortem examination, is evi-
dently incompatible with a due performance of the respiratory
function. It is not at all certain, however, that these alterations
)n the pulmonary tiasae are directly dependent on division of the
pneomogastrio nerves. It must be recollected that when the sec-
tion of the pneumogastrics is performed in the middle of the neck,
the filaments of the inferior laryngeal nerves are also divided, and
the narrowing of the glottis, produced by their paralysis, must
necessarily interfere with the free admission of air into the chest.
This difficulty, either alone or combined with the diminished fre-
qaency of respiration, must have a very considerable eifect in im-
peding the pulmonary circulation, and bringing the lungs into such
a condition as unfits them for maintaining life.

Id order to ascertain the comparative influence upon the lungs
of division of the inferior laryngeals and that of the other filaments
of the pneumogastrics, we have resorted to the following experi-
ment.

Two pnpa were taken, belonging to the same litter and of the
same size and vigor, about two weeks old. In one of them (No. 1)
the pneumogastrics were divided in the middle of the neck; and
in the other (No. 2) a section was made at the same time of the
inferior laryngeals, the trunk of the pneumogastrics being left un-
touched. For the first few seconds after the operation, there was
but litUe difference in the condition of the two animals. There was
the same obstruction of the breath (owing to closure of the glottis),
the same gasping and sucking inspiration, and the same frothing at
the mouth. Very soon, however, in pup No. 1, the respiratory
movements became quiescent, and at the same time much reduced
in frequency, falling to ten, eight, and fiye respirations per minute,
as usual after section of the pneumogastrics; while in No. 2 the re-
spiration continued frequent as well as laborious, and the general
signs of agitation and discomfort were kept up for one or two hours.

4C6

•THB cmAfflAIi HEBTKS.

The animal, towever. after that time became exTiauste^, cool, and
partially insensbile, like the other. They both died, between thirty
aod forty hours after the oporatiou. On posl-tnortem inspection it
was found that the pcoultar congestion and &olidlficatioa of the
langs, considered as chnractcristic of division of the pneumogastrics,
existed to a similar extent in each instance; and the only appro*
ciable difleruncti between the two bodies was that in No. 1 the blood
was coagulated, and the abdominal organs natural, while in No. 2
the blood was fluid and the abdominal organs congested. We are
led, aocordingly, to the following conclusions with regard to tbo
effect produced by division of this nerve.

1. After section oi the pneumogastrics, death takes place by a pecu-
liar congestion of ;he lungs. •

2. This congestion is not directly prodnced by division of tha
nerves, but is caused by the imperfect admissioa of air into the
chest.

In adult doga, the closure of the glottis from paralysis of the
laryngeal muscles is less complete than in papa; but it is still
sufficient to exert a very decided ioQuence on respiration, and to
take an active part in the production of the sub&equeDl morbid
phenomena.

We therefore regard the death which takes place aAer division
of both pncumogasiric nerves, as produced in the following man*
ner": —

The glottis ia first narrowed by paralysis of the laryngeal mus-
cles, and an imiierfect supply of air is cooaequcntly admitted, by
each inspiration, into the trachea. Next, the stimulus to respiration
being very much diminished, the respiratory movements take place
less frequently than usual. From these two causes combined, the
blood is imperfectly arterialized, and the usual consequenoe of such
a condition then follows, vi/.., a partial stagnation of the pulmonary
circulation. This stagnation still further impedes the action of the
lungs; while it does not excite the respiratory muscles to increased
activity as it would do in health, owJug to the division of the pneu-
mogastrics. At the same time, the accumulation of carbonic acid
in the blood and in the tissues begins to exort n narcotic effect,
diminishing the sensibility of the nervous centres, and tending to
retard still more the movements of respiratioa. Thus all
causes react upon and aggravate each other; because the oodi
tion, naturally existing between imperfectly arterialized blood and
the stimulus to respiration, is now destroyed. The narcotism and

PNEUHOOASTRIC NEBTE. 467

pnlmonarj eogorgement, therefore, continue to increase, until the
laogs are so seriously altered and engorged that thej are no longer
capable of transmitting the blood, and circulatioa and respiration
come to an end at the same time.

It roust be remembered, also, that the pneumogaatrio nerve has
other important distributions, beside those to the larynx and the
langa; and the effect produced by its division upon these other
organs has no doubt a certain share in producing the results which
follow. Bearing in mind the very extensive distribution of the
pneumogastric nerve and the complicated character of its func-
tions, we may conclude that afUr section of this nerve death takes
place from a combination of various causes; the most active of
which is a peculiar engorgement of the lungs and imperfect per-
formance of the respiratory function.

i^oTnachj and Digestive Function. — Ai^er division of the pneumo-
gastric nerves, the sensations of hunger and thirst remain, and the
secretion of gastric juice continues. Nevertheless the digestive
function is disturbed in various ways, though not altogether abo-
lished. The appetite is more or less diminished, as it would be
after any serious operation, but it remains sufBciently active to
show that its existence is not directly dependent on the integrity of
the pneumogastric nerve. Digestion, however, very seldom takes
place, to any considerable extent, owing to the following circum-
stances: The animal is frequently seen to take food and drink with
considerable avidity; but in a few moments afterward the food and
drink are suddenly rejected by a peculiar kind of regurgitation.
This regurgitation does not resemble the act of vomiting, but the
substances swallowed are again discharged so easily and instan-
taneously as to lead to the belief that they had never passed into
the stomach. Such, indeed, is actually the case, as any one may
convince himself by watching the process, which is often repeated
by the animal at short intervals. The food and drink, taken volun-
tarily, pass down into the oesophagus, but owing to the paralysis of
the muscular fibres of this canal, are not conveyed into the stomach.
They accumulate consequently in the lower and middle part of the
oesophagus; and in a few moments are rejected by a sudden anti-
staltio action of the parts, excited, apparently, through the influence
of the great sympathetic.

The muscular coat of the stomach is also paralyzed to a con-
siderable extent by section of this nerve. Longet has shown, by
introducing food artificially into the stomach, that gastric juice

458

TBE ORANIAL NSBVBB.

may be secreted aad the food be actually digested and disappear,
when introduced in small quantity. liui when introduced in large
quantity, it remains undigested, and is found after deaili, with the
exterior of the mass sofienc*! and permeated by gaBtric juice, while
the central portions are unnUered, and do not even seem to have
come in contact with the digestive Huid. This is undoubtedly
owing both to the diminished sensibility of the mucous membrane
of the stomach, and to the pani lysis of its muscular iihrea. ThtM
peristaltic action of the organ is very important in digestion, in ■
order to bring successive portions of the food in contact with the
mucous membrane, and to carry away such as are already sofiened
or as are not capable ot' being digested ia the stomach. This _
constant movement and agitation of the food is probably also ona f
great stimulus to the continued secretion of the gastric juice. The
digestive fluid will therefore be deficient in quantity after division
of the pneumogaatric oerve, at the same time that the perisUUtic
movements of the stomach are suspended. Under these circum-
stances, ihe secretion of gastric juice may be sufficient to pcrmcite
and digest small quantities of food, while a larger mass may resist
Its actioD, and remain uadigested. The effect produced by diriaioD
of these nerves on the digestive, as on the respiratory organs, is
therefore of a complicated character, and results from the combined
action of several dill'erent causes, which iiiOueuce and modify each
other.

The effeot produced upon the liver by soction of the pneumo-i
gastrics, as well a.<i the influence usually exerted by these nerves'
upon the hepatic functions, has beeu so little studied that nothing
doHuite has been ascertained in regard toil. We shall therefore
pass over this portion of the subject in silence.

Spinal Accessory. — This nerve originates, by many Blamcnis,
from the side of the medulla oblongata, below the level of the
poeumogastrio, and also from the lateral portions of the spinal cord,
between the anterior and posterior roots of the upper five or six
cervical nerves. These 6bres of spinal origin pass upward, uniting
into a alcuder rounded filament, which enters the cavity of the
cranium by the foranii;n magnum, and is then joined by the fibres
which originate fram the medulla oblonguta. The spinal accessory
nerve, thus con^ititutwl, passes out from the cavity of the skull by
the posterior foramen tacerum, in company with the glosso-pbaryn-
geal and paeumogastrio nerves. Immediately afterward it divides '

SPINAL AOCZftSOBT. 459

into two priocipal branches: First, the internal or aruuiomoUc
branch, which joins the pnenmogastric nerve, and becomes mingled
with its fibres; and, secondly, the external or mtueular branch,
which passes downward and outward, and is distributed to the
Btemo-naastoid and trapezius muscles.

The spinal accessory is essentially a motor nerve. It has been
found, both by Bernard and Longet, to be insensible at its origin,
like the anterior roots of the spinal nerves; bnt if irritated after
ita exit from the skull, it gives signs of sensibility. This sensibi-
lity it acquires from the filaments of inosculation which it receives
from the anterior branches of the first and second cervical nerves.
Though its external branch, accordingly, is exclusively distributed
to muscles, as we have already seen, this branch contains some sensi-
tive fibres, which have the same destination. The reason for this
anatomical fact, viz., that motor nerves are supplied during their
coorae with sensitive fibres, becomes evident when we reflect that the
muscles themselves possess a certain degree of sensibility, though
less acute than that which belongs to the skin. The sensibility of
the muscles is undoubtedly essential to the perfect performance of
their function; and as the motor nerves are incapable, by them-
selves, of transmitting sensitive impressions, they are joined, soon
afier their origin, by other filaments which communicate to them
this necessary power.

The most Important result which has been obtained by experi-
ment upon the spinal accessory nerve is that its internal or anasto-
motic branch is directly connected with the vocal movements of the
ghUu, It has been found by Bischoff, by Longet, and by Bernard,
that if the spinal accessory nerves on both sides, or their branches
of inosculation with the pneumogastric, be divided or lacerated,
the pneumogastric nerves themselves being lefl) entire, the voice is
instantly lost, and the animal becomes incapable of making a vocal
Bound. We have also found this result to follow, in the cat, afler
the spinal accessory nerves have been torn out by their roots,
through the jugular foramen. The animal, after this operation, can
no longer make an audible sound. At the same time the respira-
tory movements of the glottis go on undisturbed, and most of the
other animal functions remain unafiiscted.

The fibres of commonication, therefore, derived from the spinal
aooessory, pass to the pnenmogastric nerve and become entangled
with its other filaments, so that they can no longer be traced by
anatomical dissection. They pass downward, however, and become

460

THE CEA1

tERVES.

a pflrt of the motor fibres of llie inferior laryngeiil or Tccarrent
braiicbes of the pneumogastric ; being finally distributed to the
muscles of the larynx, which they supply with those nervous in6u-
ences which are required for the formation of the Toico.

The special function of the entemal or muscular branch of the
spinal accessory is not so fully understood. Thi« branch, as we
have seen, is distributed to the sterno-mastoid and trapezius map-
oles. But iheso muscles also receive (^laments from the cervical
spinal nerves; Qod, accordingly, they still retain the power of mo-
tion, to a certain degree, after the external branches of the spinal
aocessory have been divided on both sides.

The spinal acuessury is, accordingly, a nerve of very peouliar
distribution. For it partly supplies motor fibres to the pneumo-
gastric nerve, and is partly distributed to two muscloa, both trf
which also receive motor nerves from another source. Sir Charles
Bell, noticing the close connection between this nerve and the
pneumogostric, regarded the two as associated also in their func-
tion, as nerves of respiration. lie considered, therefore, the exter-
nal branch of the spinal accessory as destined to assist in the
movoracnts of respiration, when these movements bcoomo nnusa-
ally laborious, by bringing into play the sterno-mastoid and trape-
zius muscles, in aid of tlic action of the intcrcostala. He therefore
called this nerve the "superior respiratory nerve."

But the most satisfactory explanation of this peculianty is that
proposal by M. Bernard. According to this explanation, whenever
a muscle, or set of muscles, derive their nervous inQuence from two
di0t:rent sources, this is not for the purpose of ashling them in the
performance of the same function, hut of enabling them to perform
iico (iij)'erau finvcivma. We have scon this already exemplified in
the muscles of the larynx. For these muscles perform certain
movementsof respiration for which they receive indirectly filaments
from the facial, hypoglossal, and cervical nerves. But they also
perform the movements necessary to the formation of th^ voice, the
nervous stimulus for which is derived altogether from the spinal
accessory.

The internal branch of the spinal accessory, accordingly, exoiUis,
in the parts to which it is distributed, a function which is incompa-
tible with respiration. For the movements of respiration cannot
go on while the voice is sounded; and a necessary preliminary
to the production of a vocal sound, is the temporary stoppage of
respiration. The movements of respiration, therefore, and iUo

HTFOOL088AL. . 461

moTements of tbe Toice Slternate witli each other, bat are never
simultaneotu ; bo that the internal branch of the spinal accessory is
antagonistic to the motor fibres of the laryox derived from other
nerves.

It is thought by M. Bernard, that the fibres of the external
branch of the spinal accessory have also a function which is anta-
gonistic to respiration. For respiration is naturally suspended io
all steady and prolonged muscular efforts. In these efforts, such as
those of straining, lifting, and the like, the movements of respira-
tion cease, the spinal column is made rigid by the contraction of
its moacles, and the head and neck are placed in a fixed position,
principally by the contraction of the stemo-mastoid and trapezius
moscles. The function of the spinal accessory, in both its branches,
is therefore regarded as destined to excite movements which are
incompatible with those of respiration; and which accordingly come
into play only when the ordinary movements of respiration have
been temporarily suspended.

Htpoolossal. — The hypoglossal nerve originates from the ante-
rior and lateral portions of the medulla oblongata, and passing out
by the anterior condyloid foramen, is distributed exclusively to the
muscles of the tongue. Irritation of its fibres in any part of their
conrse produces convulsive twitching in this organ. Its section
paralyzes completely the movements of the tongue, without affect-
ing directly the sensibility of its mucous membrane. This nerve,
accordingly, is the motor nerve of the tongue. If irritated at its
origin, the hypoglossal nerve, according to the experiments of
Longet, is entirely insensible ; but if the irritation be applied in the
middle of its course, signs of pain are immediately manifested. Its
sensibility, like that of the facial, is consequently derived from its
inosculation with other sensitive nerves, afler its emergence from
the skull.

402

IPECtAb I9EXSEB.

CHAPTER VI.

THK SPECIAL SENSES

General and Special ScNsrBir.irv. — We have already seen
that there exists, m the general intcgumeut, a power of sensAtion, by
which we arc made acquainted with stirrouading objects and some
of ibeir moat importHnt physical qualities. By this power we Feel
the sensations of heat and cold, and arc enabled to distiogaish
between hard and soU substances, rough bodies and smooth, solids
and liquids. This kind of power is termed Oeneml Sensititity,
because it resides in the general integument, and because by its
aid we obtain inEbrniatioa with regard to the simplest aad moat
material properties of external objects.

The general sensibility, thus existing in the intcgament, is an
eadowment of the sensitive nerves derived from the cerebro-spinal
system. These nerves ramify in the substance of the skin, aad by
subsequent inosculation form o minute plexus in the superficial
portions of the tissue of tbe corium. Frutn this plexus, the altl*
mate Jilaments, reduced to an exceedingly minute stzc, pass up*
ward into tbe conical papilt» with which the free surface of the
corium is covered!. In the pupillui the nervous QIaments termiDOte,
sometimes by loops returning upon themselves, and siimctimes ap-
parently by free extremities. The papilloB are also supplied with
looped capillary bloodvessels, and are capable of recciviug an
ttbundaut vascular injection.

These papillie appear to be the most essential organs of general
sensation, since the sensibility of the skin is most acute where they
arc most abundant and most highly developed, as, for example, on
ibe palm of the hand and the tips of tbe fingers.

The best method of measuring accurately the sensibility of dif-
fcrent. regions is that adopted by Professors Weber and Vfilentio.
They applied tbe rounded points of a pair of compaaacs to the
integument of dlfierent parts, and found that if they were held
very near together they could oo lunger be distinguished as scpa-

OBNSBAL AND SPSOIAL SENSIBILITT. 463

nte points, bat the two senaatiooa were confounded into one. The
distance, however, at which the two points failed to be distinguished
from each other, was much shorter for some parts of the body
than for others. Prof. Valentin's measurements,' which are the
most varied and complete, give the following as the limits of dis-
tinct perception la various parts: — •_

Pabu Lisb.

At tb« tip of tongae 483

" palmAT Barface of tips of fiogen .... .723

M " " of second phsUogea . . . l.IiSS

•• " " of flnt phalangea .... 1.690

" domm of tongno 2.900

** dorsal •Drfkce of fingen 3.000

" cheek 4.541

<' back of hand 6.966

" akin of throat 8.292

*■ dorSBm of foot 12.629

" skin oTer at«rnQm 19.879

" mlddls of baok 24.206

This method cannot, of course, give the absolute measure of the
aeuieneu of sensibility in the different regions, since the two points
might be less easily distinguished from each other in any one re-
gion, and yet the absolute amount of sensation produced might be
as great as in the surrounding parts; still it is undoubtedly a very
accurate measure of the delicacy of tactile sensation, by which we
are enabled to distinguish slight inequalities in the surface of solid
bodies. We find, furthermore, that certain parts of the body are
particularly well adapted to exercise the function of general sen-
sation, not only on account of the acute sensibility of their integu-
ment, but also owing to their peculiar formation. Thus, in man,
the hands are especially well formed in this respect, owing to the
articalation and mobility of the fingers, by which they may be
adapted to the surface of solid bodies, and brought successively
in contact with all their irregularities and depressions. The hands
are therefore more especially used as organs of touch, and we are
thus enabled to obtain by their aid the most delicate and precise
information as to the texture, consistency, conSgnratiou, &c., of
foreign bodies.

But the hands are not the exclusive organs of touch, even in the
human snbject, and in some of the lower animals, the same func-

■ Id Todd'a Cjclopsdla of Anatomy and Physiologj, vol. iv., article on Toacli,
hj Dr. Carpenter.

464

IPBClAL SENSES.

tion is fully performed by various other parts of the body. Tbas
in the cat aod ia the seal, the toDg briatlea seated upon tbe lips ore
uaed for this purpose, each bristle being connected at its base with
a highly developed ncrroua papilla: in some of the niODkeysthe
extremity of the prehensile tail, and in the elephant the end of tha
uose, which is developed into a flexible and sensitive proboecis, is
employed as au orgaa of touch. This function, tbererure, may be
performed by either one part of the body or another, provided the
accessory organs bo developed in a favorable manner.

About the head and face, the sensibility of the akin is dependent ■
mainly upon branches of the fifth pair. In the neck, trunk, and
extremitleH it ia due to tbe sensitive fibres of tbe cervical, dorsal,
and Itfmbar spinal nerves. It exists also, to a considerable extent,
in the mucous membranes of the mouth and nose, and of the pas-
sages leading from them to the interior of the body. In these
situations, it depends upon the sensitive filamcDta of certain of the
crauiut nerves, viz., the fifth pair, the glusfio- pharyngeal, and the
pncumogastric The sensibility of the mucous membranes ia most
acute in those parts supplied by branches of tbe fifth pair, viz., the
conjunctiva^ anterior part of the nares, inside of the lips and cbeek%
Kud the anterior two-thirds of tbe tongue. At the base of the
tongue and in the fauces, where the mucous membrane ia supplied
by filamenta of the glosso-pharyngcal nerve, the general sensibility
is less perfect; and finally it diminishes rapidly from the upper
part of the cesopbagus and the glottis toward the stomach and tbe
luDgs. Thus, we can appreciate the temperature and consistency
of a foreign substance very readily in the mouth and fauces, but
these qualities are less distinctly perceived in the ccsophagas, and
not at all iu tbe stomach, unlei»j the foreign body happen to be
c-xcBAsively hot or cold, or unusually hard and angular in shape.
Tbe general sensibility, which is resident in tbe skin and in a certain
portion of the raucous membranes, diminishes in degree from with-
out inward, aud disappears altogether in those organs which are
not supplied with nerves from the cerebro-spiual system.

It ia particularly to be observed, however, that while the general
sensibility of the skin, and of the mucous membranes above men-
tioned, varies in acutenesa in difierent parts of the body, it is etvry*
where the game m kind. The tactile sensations, produced by tbo
contact of a foreign body, are of precisely the samo nature whether
they be felt by the tips of the fingers, the dorsal or palmar surfaoes
of the hands, the lips, cheeks, or any other pan of the integument.

TASTE. 466

The only difference in the sensibility of these parts lies io the de-
gree of its development.

Bat there are certain other sensaUons which are different in kind
&om thoaa perceived bj the general integument, and which, owing
to their peculiar and special character, are termed special amBoiiona.
Sack are, for example, the sensation of light, the sensation of soand.
the sensation of savor, and the sensation of odors. The special
sensibility which enables us to feel the impressions derived from
these soarces is not distributed over the body, like ordinary sensi-
bility, but is localised in distinct organs, each of which is so con-
stituted as to receive the special sensation peculiar to it, and no
other. •

Thus we have, beside the general sensibility of the skin and
mucous membranes, certain peculiar faculties or special senses, as
they are called, which enable us to derive information from ex-
ternal objects, which we could not possibly obtain by any other
means. Thus light, however intense, produces no perceptible sen-
sation when allowed to fall upon the skin, but only when admitted
to the eye. The sensation of sound is perceptible only by the
ear, and that of odors only by the olfactory membrane. These
different sensations, therefore, are not merely exaggerations of
ordinary sensibility, but are each distinct and peculiar in their
nature, and are in relation with distinct properties of external
objects.

In examining the organs of special sense, we shall find that they
each consist — First, of a nerve, endowed with the special sensibility
required for the exercise of its peculiar function; and. Secondly, of
certain accessory parts, forming an apparatus more or less compli-
cated, which is intended to assist in its performance and render it
more delicate and complete. We shall -take up the consideration
of the special senses in the following order. First, the sense of
Taste; second, that of Smell; third, that of Sight; and fourth, that
of Hearing.

Tasts. — We begin the study of the special senses with that of
Taste, because this sense is less peculiar than any of the others, aod
differs less, both in its nature aod its conditions, from the ordinary
sensibility of the skin. In the first place, the organ of taste is no
other than a portion of the mucous membrane, beset with vascular
and nervous papillae, similar to those of the general integument.
Secondly, it gives us impressions of such substances only as are
SO

466

UL SSN'SBS.

actoall^ in contact with sensitive surfaces, and can establish no
cotntnuiiication with objects at a distance. Thiittly, the surfaces
which exercise the sense of taste are also endowed with general sen-
nibility; and Fourthly, there is no one special and distinct nerve
of taste, but this property resides in portions of two diSerent
nerves, viz,, the fifth pair and the glosso-pharyngeal ; nerve* which
also supply general seusibility to the mouth and »urrouudiug parts.

'J'he seii5e of taste is localized in tlie mucous membrane of the
tongue, the mfl palate, and the fauces. The tongue, which ia more
particularly the scat of this sense, is a flattened, leaf-like, nDuacular
organ, attached to tlie inner surface of the symphysis of the lower
jaw in front, and to tluj os hyuides behind. It has a vertical sheet
or lamina of fibrous tissue, in the median line, which serves as a
framework, and is provided with an abundance of longitudinal
transverse and radiating muscular Sbrcs, by which it can be elon-
gated, rolrautcd, and moved alxiut in every direction.

Ttie mucous membrnne of the fauces and posterior third of the
tongue, like that lining the cavity of the mouth, is covered wiih
minute vascular papilW, similar to those of the skin, which iire,
however, Imbedded and concealed in the smooth layer of epithe-
lium forming the surface of the organ. But about the junction of
its posterior and niidtUe thirds, there is, upon the dorsum of the
tongue, a double row of rounded eminences, arranged in a V-shaped
figure, running forward and outward, on each side, from the situa- I
tion of the foramen cajcum; and, from this point forward, the upper ■
surface of the organ is everywhere covereil witli an abundance of
thtckly-set, highly developed papillae, projecting from its surface, ■
and readily visible to the naked eye.

These lingual pnpillie are naturally divided into three diflerent
sets or kinds. Fir^i, thofiU/orm papilla^ which are the most nume-
rous, and which cover most uniformly the upjior surface of the
organ. They are long and slender, and are covered with a some-
what horny epithelium, usually prolonged at their free extremity
into a nianientous tuft. At the edges of the tongue these papillia
are often united into parallel ranges or ridges of the mucous mem-
brane. Secondly, th& /unffi/orm papilla. These are thicker and
larger than the others, of a rounded club-shaped figure, and covered
with sfjft, permeable epithelium. They are most abundant at the
tip of the longue, but may be seen olsewhcro on the surface of the
organ, scattered among the filiform piipillfe. Thirdly, the eircum-
taUau papill<t. These arc the rounded eminences which form the

TASTB*.

V-8haped figure near the situation of the foramen oecum. They
are eight or ten in number. Each one of them is surrounded bj
a circular wall, or circumvallation, oT mucoua rriuinbrano, which
giree to them their distinguishing appellation. The oiroumvalla-
lion, 03 well aA the central ominenee, ha-t a stmctarc similar to that
of the fungiform papillae,

The senaitivu nerves of Ibe tongue, as we have already seen, are
two in number, viz., tho lingual branch of the ildh pair, and the
lingual ))ortion of tho glosao- pharyngeal. The lingual branch of
the fifth pair enters the tongue at the anterior border of the hyo-
glossus muacle, and its fibres then run through the muscular tissue
of the organ, from below upward and froiu behind forward, with-
out any ultimate distribution, until they reach the mucoua mem-
brane. The nervous filnmenta then penetrate into the lingual
papill.-e, where they finally terminate. The exact mode of their
termination is not positively known. According to Kolliker, they
aometimes seem to end in loops, and sometimes by free extremities.

The lingual portion of tho glosso- pharyngeal, nerve passes into
the tongue below the posterior border of the hyo-gloasus muscle.
It then divides into various branches, which pass through the mus-
cislMr tissue, and are finally distributed to the mucous membrane of
the base ftad sides of the organ.

Fi«. 153.

-r:^

1 DlMa^phurnfMl ntrr*.

The mucous raombrano of the base of the tongue, of its edges,
and its under surface near the tip, as well as the mucous membrane
of the mouth and fauces generally, is also supplied with mucouR
folHcles, which furnish a viacid secretion by which the free surface
of the parts is lubricated.

Finally, the muscloa of the tongue, it will be remembered, are
animated exclusively by the filaments of the hypoglossal nerve.

463

THE 8PBCTAI. SCNSKS.

The exact trat of the aense of taste haa been dBlemiined bv
placing in contact with dilferent parta of the muooua tneinbratie a
amall sponga, moistened with a solation of aome sweet or bitter
substance. The experiments of Vemi^, Longet and others hata
sbowD that the sense of taste resides id the whole superior sarface,
the point and edges of the tongue, the sofl palate, fauces, and part
of the pharynx. The base, lip, and edgea of the tongue Beem to
posseaa the most acute sensibility to savors, the middle portion of
its dorsum less of this seasibility, and its iuferior surfaces little or
none. Now as the whole anterior part of the organ is supplied by
the lingual branch of the 6l\h pair aboe, and the whole of its
posterior portion by the glosso -pharyngeal, it follows that the sense
of taste, in these diflerent parts, is derived from these two difTereni
nerves.

Furthermore, the tongue is supplied, at the same time and hy the
same nerves, mith general senBibility and with the special aensibility of
latte. The general sensibility of the anterior portion of the tongna,
and that of the branch of the 6fth pair with which it is supplied,
are sufFiciently well knovru. Section of the 6fth pair destroys the
sensibility of this part of the tongue as well as that of the rest of
the face. Longet has found that after the lingual branch of this
nerve has been divided, the mucous membrane of the anterior two-
thirds of the tongue may be cauterized with a hot iron or with
caustic potassa, in the living animal, without producing any sign of
pain. Dr. John Reid, on the other hand, together with other experi-
menters, has determined that ordinary sensibility exists in a marketl
degree in the glosso-pharyngenl, and is supplied by it to the parta
to which this nerve is distributed.

Accordingly we must distiuguish, in the impressions produced
by foreign substances taken into the mouth, between the special
impressiom derived from their sapid qualities, and the general Anua-
tions product hy their ordinary physical properties. As the tongue is
exceedingly sensitive to ordinary impressions, and as the same body
is often capable of exciting both the tactile and gustatory functions,
these two properties arc sometimes liable to be confounded with
each other by careless observation. The truly sapid qualities,
however, the only ones, properly speaking, which we perceive bj
the sense of taste, are such savors as we designate by the term
au-eet, biiier, salt, sour, alkaline, and the like. But there are many
other properties, belonging to various ajticles of food, which belong
really to the cUas of ordinary physical qualities and are appre-

TASTE. 469

ciated by the ordinary seosibility of the tongue, though we usually
speak of them as being perceived by the taste. Thus a starchy,
vitdd^ watery, or oleaginous taste is merely a certain variety of con-
sistency in the substance tasted, which may exist either alone or in
oonnection with real savors, but which is exclusively perceived by
means of the general seissibility. So also with & pungent or burning
taste, such as that of red pepper or any other irritating powder.
The quality of piquancy in the preparation of artificial kinds of
food is always communicated to them b; the addition of some such
irritating substance. The styptic taste seems to be a combination of
an ordinary irritant or astringent effect with a peculiar taste, which
we always associate with the former quality in astringent sub-
stances.

There is also sometimes a liability to confound the real taste of
certain substances with their odorous properties, or flavors. Thus
in most aromatic articles of food, such as tea and coffee, and in
various kinds of wine, a great part of what we call the taste is in
reality due to the aroma, or smell, which reaches the nares during
the act of swallowing. Even in many solid kinds of food, such as
freshly cooked meats, the odor produces a very important part of
their effect on the senses. We can easily convince ourselves of this
by holding the nose while swallowing such substances, or by recol-
lecting how muoh a common catarrh interferes with our perception
of their taste.

The most important conditions of the sense of taste are the fol-
lowing:—

In the first place, the sapid substance, in order that its taste may
be perceived, must be brought in contact with the mucous mem-
brane of the mouth in a state of solution. So long as it remains
solid, however marked a savor it may possess, it gives no other
impression than that of any foreign body in contact with the sensi-
tive surfaces. But if it be applied in a liquid form, it is then spread
over the surface of the mucous membrane, and its taste is imme-
diately perceived. Thus it is only the liquid ^nd soluble portions
of our food which are tasted, such as the animal and vegetable
juices and the soluble salts. Saline substances which are insoluble, .
such as calomel or carbonate of lead, when applied to the tongue,
produce no gnstatory sensation whatever.

The mechanism of the sense of taste is, therefore, in all proba-
bility, a direct and simple one. The sapid substances in solution
penetrate the lingual papillae by endosmosis, and, coming in actual

THE BPBOTAt BBN8E8.

contact with tlie termioal nervous filaments, excite their aeosibilitr
by uniting witb their substance. We have already seen that the
rapidity with which endosmosis will take place under certain con-
ditiong ia suHicicnlly great to acooant for the almost iastantaneous
perception of the taste of sapid substances when introdoced into the
muuth.

It ia on thia accoant that a free secretion of the salivary fluids ia
so essential to the full performance of the gustatory function. If
the mouth be dry and parched, our food seems to have lost ita taste;
but whoD the saliva is freely secreted, it is readily mixed with the
food in masticatiuTi, and assists in the solution of ita sapid ingredi-
ents; and the fluids of the mouth, thus impregnated with the savory
substances, are absorbed by the mucous membrane, and excite the
gustatory nerves. An important part, also, is taken in this process
by the movements of the tongue; for by these movements the food
is carried from one part of the mouth tu another, pressed against
the hard palate, the gums, and the cheeks, its solution assisted, and
the penetration of the fluids into the substance of the papillse moro
rapidly accomplished. If a little powdered sugar, or some y«go-
table extract be simply placed upon the dorsum of the tongue, bat
little ettect is produced; but as soon as it is pressed by the tongue
against the roof of the mouth, as naturally happens in eating or
drinking, its taste is immediately perceived. This effect is easily
explained; since we know how readily movement over a free sur-
face, combined with slight friction, will facilitate the imbibition of
liquid substances. The nervous papillae of the tongue may there-
fore be regarded as the essential organs of the sense of taste, and
the lingual muscles as its accessory orgaus.

T/ie/ult ejfeci of sapid substances is not obtained until they are a^u-
ally swallowed. During the preliminary process of mastication a
sufficient degree of impression is produced to enable us to perceive
the presence of any disagreeable or injurious ingredient in the food,
and to get rid of it, if we desire. But it is only when th« food is
carried backward ^to the fauces and pharynx, and is compressed
by the constrictor muscles of these parts, that we obtain a complete
perception of its sapid qualities. For at that time the food is spread
out by the compression of the muscles, and brought at oooe in J
contact with tbe entire extent of the mucous membrane possessing *
gusLative sensibility. Then, it is no longer under the control of the
will, and is carried by the reflex actions of the pharynx and ceso-
phugus downward to the stomach.

TASTE. 471

Tbe impressions of taste made npon the tongue remain for a cer-
tain time afterward. When a very sweet or very bitter substance
is taken into the mouth, we retain the taste of its sapid qualities
for several seconds after it has been ejected or swallowed. Conse-
qaently, if several different savors be presented to the tongue in
rapid suoceanon, we soon become unnble to distinguish them, and
they produce only a confused impression, made up of the union of
varioQS different sensations; for the taste of the first, remaining in
the month, is mingled with that of the second, the taste of these
two with that of the third, and so on, until so many savors become
confounded together that we are no longer able to recognize either
of them. Thus it is notoriously impossible to recognize two or
three different kinds of wine with the eyes closed, if they be repeat-
edly tasted in quick succession.

If the substance first tasted have a particularly marked savor,
its taste will preponderate over that of the others, and perhaps pre-
vent oar riscognizing them at all. This effect is still more readily
produced by substances which excite the general sensibility of the
tongue, such as acrid or stimulating powders. In the same manner
as a painful sensation, excited in the skin, prevents the nerves, for
the time, from perceiving delicate tactile impressions, so any pungent
or irritating substance, which excites unduly the general sensibility
,of the tongue, blunts for a time its special sensibility of taste. This
effect is produced, however, in the greatest degree, by substances
which are at the same time sapid, pungent and aromatic, lilce sweet-
meats flavored with peppermint. Advantage is sometimes taken
of this in the administration of disagreeable medicines. By first
taking into the mouth some highly flavored and pungent substance,
nauseons drugs may be swallowed immediately afterward with but
little perception of their disagreeable qualities,.

A very singular fact, in connection with the sense of taste, is that
it ia tometimes affected m a marked degree by paralysis of the facial
nerve. No less than six cases of this kind, occurring in the human
subject, hare been collected by M. Bernard ; and the same observer
has seen a similar effect upon the taste produced in animals by
division of tbe facial nerve within the cranium. Tbe result of these
experiments and observations is as follows: When the facial nerve
is divided or seriously injured by organic disease, before its emerg-
ence from the stylo-mastoid foramen, not only is there a paralysis
of the superficial muscles of the face, but the sense of taste is
diminished on the corresponding side of the tongue. If the tongue

472

THE SPBOIAIj senses.

be prolruJed, aod powdered citric acid or salphato of qniaino be
placed upon its aurfaco on tbo two sidea uf the median line, the taste
of these substanoes ia perceived on the affecicd side more slovljr
and obscurely thao on the other. It is not, therefore, a destructioo,
but only a diminution of the sense of taste, which follows paralyats
of the fucinl in these in&Uinces. At the same time the general tactile
sensibility of the tongue is uualtered, rotainiog its natural acutenon
on both sides of the tongue.

The exact mechanism of this peculiar in6uenc« of the facia] nenre
upon the sense of Lasta is not perfectly understood. It may be
considered as certnui, however, that it is derived through the
medium of that branch of the facial nerve known as the ehonla
lympani. This filametit leaves the facial at the intumescentia
gangliformis, in the interior of the aqueduct of Fallopius, enters the
cavity of the tympanum, passes across the membrane of the tym-
panum, and then, cmcrgiug from the cranium, runs downward and
forward and joins the lingual branch of the fifth pair. It then ac-
companies this nerve as far as the posterior extremity of the sab-
maxillary gland. U»ru it divides into iwo portions; one of which
passes to the submaxillary ganglion, and, through it, to the aub- I
stance of the submaxillary gland, while the other continues onward,
still in connection with the lingual branch of the fifth pair, and, in
company with the tilamcnts ofthis nerve, isdistributed to the tongue..

The chorda tympani thus forms the only anatomical oonnection
between the facial nerve and the anterior part of the tongue. When
the facial, accordingly, is divided or injured after itit emergence
from the stylo-masloid foramen, no effect is produced, upon the
oenae of taste ; but when it is injured during its course through the
aqueduct of Falloptua, and before it has given off the chorda tym-
pani, this nerve sufl'urs at the same time, and the sense of tasie is
diminished in activity, as above deticribcd. It is probable that this
effect is produced in an indirect way, by a diminution in the activity
of secretion in the lingual ruliicle», or by some alteration in the
vascularity of the parts.

Shill. — The main peculiarity of the sense of smell conaista Id
the faot that it gives us intelligence of the physical character of
bodies in a gaseous or vaporous condition. Thus we are enabled to
perceive the existence of an odorous aubstanoe at a distance, and
when it is altogether concealed from sight. The minute quantity
of volatile material emanating from it, and thus pervading the

BUELL.

473

atmosphere, oorneii in contact with the maoous membrane of the
noae, ami thus produces a peculiar and special sensation.

The apparatus of this sense consisM, first, of the olfactory mem-
brane, supplied by the filaments of the olfactory nerve, as its
special organ; aud secondly, of the turbinated nasal poss^es, with
the turbinated bones and the muscles of the anterior and posterior
nares, as its accessory organs. At the upper part of the nasal fossie,
the mucous membrane ia very thick, sod, spongy and vascular, and
is supplied with mucous follicles which exude a secretion, by whiub
itssurfaoe ia protected and kept in a moist and sensitive condition.

It 18 only this portion of the mucous membrane of the nares
which is supplied by filaments of the olfactory nerve, and which is
capable of receiving the impressions of smell; it is therefore called
the OlfocUiry membrane. Elaewbere, the nasal passages are lined
with a mucous membrane which is fesB Tascular and spongy in
structure, and which is called the Schnfidman membrane.

The filaments derived from the olfactory ganglia, and which
penetrate through the cribriform plate of the ethmoid bone, aro
distributed to the mucous membrane of the superior and middle
turbinated bones, and to that of the upper part of the septum nasi.
The exact mode in which tliese tilameuts terminate in the olfactory
raembrone has not been definitely ascertained. They are of a soft
ooDsifllency and gray color, nriti, after dividing and ramifying freely
in the membrane, appear to become lost in ita substnncc. It is
these nerves which exercise

tb« special function of smell.
They are, lo all appearance,
incapable of receiving ordi-
nary impres.<iioDs, and must
be regarded as entirely pecu-
liar in their nature and endow-
ments. The nasal passages,
however, ore supplied with
other nerves beside the olfac-
tory. The nasal branch of
the ophthalmic division of the
fifth pair, a^r entering the
anterior part of the cavity of
the narcSfjust in advance of
the cribriform plate of the
ethtuoid bone, is distributed

KIg.lB*.

^fliUiiii^

Pakaui* .—I. UIDMIdrTIMiiilloji, wJUi tli Brrraa.
8. Kkwl bnuich gf HDb [iitlr. 3. 8)itaoa-p>latlD«

474

TUB SPECIAL SENSES.

to the mucous membrane of the inferior turbinated bone an*! llie
inferior meatus. Thus the organ of smell 13 provided with sensi-
tive nerves from two different sources, vi/-., at its upper part, with
the olfactory nerves proper, derived from the olfactory ganglion
(Fig. 154, 1), which are nerves of special sensation; and Beooodly,
at its lower part, with the nasal branch of the 6flh pair (9) a nerve
of general sensation. Beside which, the spheno- pal aline ganglion
of the great sympathetic (*) sends filaments to the mucous mem- .
brane of the whole posterior part of the nasal passages, and to the
levator pnlati and azygos uvulns muscles. Finally, the muscles of
the anterior nares are supplied by filaments of the facial nerve.

The conilitions of the sense of amcll are much more special in
tbeir nature than those of taste. For, in the first place, this sense i»
excited, not by actual contact with the foreign body, but only withi
its vaporous emanations; and the quantity of these emanations^
sufRuicni to excite the smell, is olWn so minute as to be altogether
inappreciable. We cannot measure the loss of weight id aaj
odorous body, though it may affect the atmosphere of an entii
house, and the senses of all ita inhabitants, for days and weeks^
together. Secondly, in the olfactory organ, the apeoial sensibility
of smell and the general sensibility of the mucou.i membrane are
separated from each other and provided for by different nerves,
not mingled together and exercised by Lhe same nerves, as is tba
uaau iu the tongue. M

In order to produce an olfactory impression, the emanations of
the odorous body must be drawn fretly thr<>ugh tfie nasal passayei.
As the sense of smell, also, is situated only in the upper part of these ■
passages, whenever an unusually faint or delicate odor is to be per-
ceived, the air is forcibly directed upward, uiward the superior
turbinated bonea, by a peculiar inspiratory movement of the no»-
triU. Thia movement is very marked in many of the lower animals.
As the odoriferous vapors arrive in the upper part of tfa« nasal
passages, they are undoubtedly dissolved in the secretions of the
olfactory membrane, and thus brought into relation with itA nerves.
Inflammatory diAordors, therefore, interfere with the sense of smell,
both by checking or altering the secretions of the parta, and by
producing an uunalural tumefaction of the mucous membrane,
which prevents the free passage of the air through the nasal foasB.

As in the case of the tongue, also, we must distinguish hora
between the perception of true odors, and the excitement of theH
general sensibility of ibe Schneiderian mucous membrane by trri*

8HBLL. 475

toting tultttmeeB. Some of the true odors are similar in their nature
to impreasioDS perceived by the sense of taste. Thus we have
sweet and soar smells, though none corresponding to the alkaline
or the bitter tastes. Most of the odors, however, are of a very
peculiar nature and are difficult to describe; but thej are always
distinct from the simply irritating properties, which may belong to
vapors as well as to liquids. Thus, pure alcohol has little or no
odor, and is only irritating to the raucous membrane ; while the
odor of wines, of cologne water, &c., is communicated to them by
the presence of other ingredients of a vegetable origin. In the
same way, pure acetic acid is simply irritating ; while vinegar has
a peculiar odor in addition, derived from its vegetable impurities.
Ammonia, also, is an irritating vapor, but contains in itself no
odoriferoofl principle.

The sensations of smell, like those of taste, remain/or a certain time
after they have been produced, and modify iu this way other less
strongly marked odors which are presented aflerward. As a
general thing, the longer we are exposed to a particular odor, the
longer its effect upon our senses continues; and in some cases it
may be perceived many hours after the odoriferous substance has
been removed. Odors, however, are particularly apt to remain
after the removal or destruction of the source from which they
were derived, owing to their vaporous character, and the facility
with which they are entangled and retained by porous substances,
such as plastered walls, woollen carpets and hangings, and woollen
clothes. It is supposed to be in this way that the odor of a [)ost-
mortem examination will sometimes remain so as to be perceptible
for several hours, or even an entire day afterward. But this alone
does not fully explain the fact. For if it depended simply on the
retention of the odor by porous substances, it would afterward be
perceived constantly, until it gradually and continuously wore off;
white, in point of fact, the physician who has made an autopsy of
this kind does not afterward perceive its odor constantly, but only
occationaUy, and by sudden and temporary fits.

The explanation is probably this. As the odor remains con-
stantly by us, we soon become insensible to its presence, as in the
case of all other coutinuous and unvarying impressions. Our at-
tention is only called to it when we meet suddenly with another
and familiar odor. This secoud odor, we find, does not produce its
usual impression, because it is mingled with and modified by the
other, which is more persistent and powerful. Thus we are again

476

THE SPECIAL SENSES.

made aware of the former one, to wbicb we had become insennble
by rtasyii of its constnnt presence.

The seosc of smell is comparatively feeble in the human specie^
but is excessively acuLe ia some of the lower animals. Thus, the
dog will not only distinguish differeot kinds of game in the forest| M
by this sense, and follow them by their tracks, but will readily dts- "
tinguish partiaular individuals by their odor, and will recognize
articles of dress belonging to ihem by the minute quantity of odor
iferoua vapors adhering' to their substance.

Sight.— The sight undoubtedly occupies the first raok iu the
list of fipeciul uervoua endowments. It is the most peculiar in its
operation, and the moat immaterial in its nature, of all the senses,
and it is through it that we receive the most varied and valuable
impressions. The physical agent, also, to which the organ of sight
ia adapted, and by which itA seaaibility is excited, ia more subtle
aad peculiar than any of those which act upon our other senses.
For the senses of touch, taste, and smell require, for their exercise,
the actual contact of a foreign body, either in a solid, liquid, or
aeriform condition ; and even the hearing depends upon the me-
chanical vibrations of the atmosphere, or some other sonorous
medium. But the eyo does not need to bo in contact with the
luminous body. It will receive the impressions of light with per-
fect distinctness, even when they are transmitted from an immea-
surable di&tance, as in the case of the 6xed stars; and the light
itself i.s not only immaterial in its nature, so far as we can ascertain,
but is also capable of being transmitted through space without the
intervention of any material conducting medium, yet discoverable.

Finally, the apparatus of vision is more complicated in its struc-
ture than that of any other of the special senses. Thin apparatus
consii^i.'^, Hrst, of the retina, as a specinl sensitive nervous membrane;
and secondly, of the vitreous ba<ly, crystalline lens, choroid, scle
rotic, iris and cornea, together with the muscles moving tbe eye-
ball aud eyelids, lachrymal gland, &.C., as accessory organs. The
arrangement of the parts, constituting the globe of the eye, Ja sbowa
in the following figure. (Fig. 155.)

The filaments of the optic nerve, afler running forward and pene-
trating the posterior part of the eyeball, spread out into the sub-
sUincti of the retina [s), thus forming a delicate and vascular nerv-
ous expansion, in the form of a spheroidal bag or aac, with a wide
opening in front, where the retina terminates at the posterior tnar-

SIGHT.

477

gin of the ciliary body. This expansion of the retina is the eaaen-
tial nervoas apparatus of tho eye. It is endowed with the special

Pig. Hi.

TMll(sl<lTCllaa»f Uia KtsaxuL.— I. >cl«Mllc. !. ClinrnU. S. IbllM. i. LsDi. A Tlrt-tuld
■■■BbraM. 1^ CttBfft. 7. IH*. S. Cllltirj iiiU4«U *Bd pruMMVi.

senBibllity wblch rcndcrfi it capable of receiving luminous impres*
sions ; and, go far as wc have been able to aaccrtnin, ii is incapable of
perceiving any other. On the outside, the retina is covered by the
^ionmioont {a\ a vascular membrane, which is renderud opaque by
the presenee ofan abundant layer of blackish-brown piginent-cella,
and which thns absorbs the light which hos once passed through
the retina, and prevents its being reflected in such a way as to
oonfuse and dazzle the sight. Inside the retina is tho vitreaui body,
a transparent^beroidal mass of a gelatinous consistency, which is
sarrounded and retained in position by a thin, structurelesa mem-
brane, called the hyaloid membrane (s), lying immediately in
oontaot with the internal surface of the retina. The lerut (<) is
placed in fl^nt of the vitreous body, in the central axis of the eye-
ball, enveloped in its capsule, which is continuous with the hyaloid
membrane. Just at the edge of the lens, the hyaloid membrane
divides into two lamtnse, which separate from each other, leaving
between them a triangular canal, the canal of Petit, which can be
seen in the above figure. In front of the lens ia the iris (i), a nearly
vertical muscular curtain, formed of radiating and concentric Bbres,
pierced at its centre with a circular opening, the pupil^ through
which the light is admitted, and covered on its jioeterior surface
with a continuation of the choroidal pigment, which excludes the
passage of any other rays than those which pass through the pupil.

478

IE SPECIAL SRyfRS.

At the sftmo time, the whnle globe tg inclosed anJ protected by »\
thick, fibrous, laminated tanic, which in its |i08tenor and middle
portions is opaque, forming the sclerotic (i), and id its anterior por-
tion is transparent, forming tliu cornea (s). The muscles of the eje-
ball are attached to the external surface of the sclerotic in such a.
way thai the cornea may be readily turned in various directions;!
while iho eyelids, which may be opened and closed at will, protect]
the eyo from injury, and, with the aid of the lachrymal secretion,^
keep ita anterior surfaces moist, and preserve the transparency ofj
the cornea.

The organ of vision is supplic<l with nerves of ordinary aensi-
bility by the ophthalmic branch of the 6fih i>air. The filamenU;
of this nerve which terminate about the eye are distributed mostlyj
10 tho conjunctiva, lachrymal gland, and akin of the eyelids; whiU
a very few of them run forward in company with the ciliary nerves]
proper, and arc distributed to the etliaiy circle aud Iris. All ll
parts, therefore, but more particiilarly tho conjunctiva and skiu
the eyelids, possess ordinary sensibility, which appears to be totalljl
wanting iu the deeper parts of the eye. The ophthalmic ganglioc
gives oir the ciliary nerves, which are distributed to the iris and
cilinry muscle, yiually, the muscles moving the eyeball and eye
lids are supplied with motor nerves from the third, fourth, siztfa
and seventh pairs.

Of ail the properties and functions belonging to the different
structures of the eyeball, the most peculiar and characteristic is the
special sensibility of the retina. This sensibility is auoh that the
retina appreciates both the intensity and the quality ^f the light —
that is to say, its color and the different shades which this color
may present. On account of the form, also, iu which the retina is
constructed, viz^ that of a spheroidal membranous bag, with ai
opening in front, it becomes capable of appreciating the tit'recit'oH^
from which the rays of light have come, and, of course, tho situation'
of the luminous body and of its different parta. For the rays which
enter through the pupil from below can reach the retina only at its
upper part, while those which come in from above, can reach it
only at its lower part; so that in both instances the rays strike the
sensitive surface perpendicularly, and thus convey the irapresakm
of their direction from above or below.

But beside the sensibility of the retina, the perfection and value
of the sense of sight depend very much on the arrangement of the
nccessory organs, the most important of which is the crysialliue
lens.

sionT.

479

The /unction of tht eri/siafh'ne hns is (o produce Jistinei perception
of form and outline. For if the eye consisted merely of a sensitive
retina, covered with tran9[>areiit integument, lliuugh the impressions
of light would be received by such a retina they could not give
any idea of the form of particular objects, but could only produce
ibe sensation of a confused luminosity. This condition ia illus>
trated in Fig. 156, where the arrow, a, 6, repreaenta the luminous
object, and the vertical dotted line, at the right of the diagram,
represents the retina. Rays, of course, will diverge from every
|xiint in the object in every direction, anil will thug reach every
part of the retina. The different parta of the retina, coDsequeotly,
1, 2, 3, 4, will each receive rays coming both from the point of the
nrrour, a, and from its butt, h. There will therefore be nn distino-
tion, upon the retina, between thedifTerent parts of the object, and no

Pig. 1S6.

Pig. 157.

definite perception of ita outline. Cut if, between the object and tlie
retina, there be inserted a double convex refracting Icus, with the
proper curvatures and density, aa in Fig. 157, the elTect will be dif-
ferent. For then all the rays emanating from a will be concentrate*!
at a:, and all those emanating from h will be concentrated at y.
Thus the retina will receive the impression of the point of the
arrow separate from that of the butt; and all parts of the object,
in like manner, will be diatinctly and acciir»lely perceived.

This convergence of the rays of light la accomplished to a certain
eitent by the other trangparent and refracting psrls of the eyeball ;
but the lens is the most important of all in tliis respect, owing to
its superior density and the double convexity of its figure. The
distinctness of vision, therefore, dejwnds upon the action of the
lens in converging all the rays of light, emanating from a given
point, to an accurate focus, a/ the surface of the retina. To accomplish
this, the density of the tens, the curvature of its surfaces, and its
distance from the retina, must all be accurately adapted to each
other. For if the leus be too convex, and its refractive power con-

THE SPECIAL 9EK9KS.

sequentlj too great, tlie rays will be converged to a focus too soon,
and will not reach the retina until allcr they have crossed each
other and become partially dispersed; as in Fig. 158. The vigoal
impressiDii, therefore, coming from any particular point in the
object is not concentrated and distinct, but diffused and dim, from
being dispersed more or less over the retina, and interfering with
the impresaiona confiing from other parts. Thia ia the condition.
which is present in myopia, or near-sightedness. On the oth«r hand,

Fig. 168.

Fig. 159.

UlvriA.

PBtiarvrij.

if the lens be too flat, and its convergent power too feeble, as iai
Fig. 1&9, the rays will fait to conio together at all, and vrill strikal
the retina aepamtcly, producing a confused image, as before. ThUi
ia the defect which exists in presbyopia, or long-aightedoeas. Is
both cases, the immediate cause of the confusion of sight is the
same, viz., the rays coming from the &irne point of the object
striking the retina at different points; but in the first instance, this
is because the rays have actually converged to a point, and then
crossed; in the second, it is because they have only approached
each other, but have never converged Lo a focua.

Another important particular in regard to the action of the lens
is the accommodation of Oie eye to distinct vision nt different dtstane^A
It is evident that the fiame arrangement of the refractive parts, in
the eye, will not produce distinct vision when the distance of the
object from the eye is changed. If this arrangement be such that
the object is seen distinctly nt a certain dislanoo, as tn Fig. IHO,
and the object be then removed to. a remoter point, as in Fig. 161,
the image will become conHised; for the ray.t will then be coD'
verged to a focus at a point in front of the retina; because, being
less divergent, wlion ihey strike ihe Ions, the same amount of re-
fraction will bring them together sooner than before. On the other
hand, if the object be moved to a point nearer the eye, the rays,
becoming more divergent as ibey strike the lens, will be converged
less rapidly to a focus, aad vision will again become indistinct.

sroHT.

481

Ftg. 160.

This may easily be seen by the aid of a very simple experiment.
If two needles be placed upright, at diderent distances from the eye,
one for example at eight and
the other at eighteen inches, but
nearly in the same linear range,
and if then, closing one eye, we
look at tbero alternately, we shall
Snd that we cannot see both dis-
tinctly at the same time. For aa
soon QB wc look at the one near-

Fig. 181.

eat the eye, so as to perceive ita form distinctly, the imago of the
more remote one becomes confused; and when we see the more re-
mote object in perfcctioD, that which \s nearer loses its sharpness of
outline. This shows, in the 6 rat place, that the same condition of
the eye wilt not allow us to see two objccta at different distances
with distinctness at the same time; and secondly that, on looking
from one to the other^ there is a c/utnge of some kind in the focus of
the eye, by which it is adapted to diflerent distances. Indeed we
arc conscious of a certain effort at the time when the point of vision
is transferred from one object to the other, by which it is adapted
to the new distance; and this alteration is not quite instantaneous,
but requires a certain interval of time for its complijiion.

This accommodation of the eyo to diflercDt distances is un-
doubtedly effected by an antero- posterior movement of the lens
within the eyeball. It will at once be perceived, on referring to
Fig. ml, that if ihe lens were moved a little backward toward the
retina, at the same time thiit the object is removed to a greater dis-
tance from the eye, the focus of the convergent rays would still fall
upon the retina, and the image would still be distinct. In the op-
posite case, where the object is brought nearer the eye, u similar
movement of the lens forward would again secure perfect vision.
Thus, when we look at near objocta, the lens moves forward
81

482

THV BPEOIAI. 8BK8BS.

loward the popil; when we look at remote objects, it moves back-
ward toward tbe retina.

This movement of the lens is apparentlj accomplished bj the
ncCion of the ciliary muscle. This muscle (Fig. InS, b) arisea, in
front, from the conjunction of the sclerotic and tbe cornea, and run-
ulng backward and outward, is inserted into the anterior part of
tbe choroid, about tho situation ac which the hyaloid membrane
passes ofi^ to become the suspensory ligament of tbe lens. As
already mentioned, thin muicle is supplied with nervous filaments
from the ophthalmic gaogUon. Its action is to draw the lens fop
ward, by means of its attachment to the hyaloid membrane and
choroid coat; and, in the human subject, its retreat or retrogres-
sion toward the retina, ailer the ciliary muscle is relaxed, seems to
be due to the elastic resiliency of ihe remaining tissues of tbe eye-
ball.

Itut in order to allow of such a backward and forward movement
of the lens, since the liquids of the-eyebnll are incompressible, there
must be a corresponding displacement of other parts, both before
and behind. This is undoubtedly providetl for by the vascubrity
of tbe choroid coat. This membrane is supplied with anoxceedingly
abundant vascular plexus over jla whole posterior portion; and in
front it is thrown into a circle of prominent cxinvcrging folds, or
processes, the ciJiart/ processts, which are nothing more than erectile
congeries of bloodvessels, covered with the pigment of tbe choroid.
A portion of the ciliary processes projects in front of the lens, and
their vascular network is continued over a great part of the pos-
terior surface of the iris. Thus there is, both behind and in front
of the lens, an erectile system of bloodvessels j and as these blood-
vessels become alternately empty or turgid, they will allow of
displacement of tho lens in an anterior or posterior direction.

Accordingly, there is a certain accommodation of the eye ncceT
sary to the distinct sight of objects at different distances. Biit the
range of this accommodation is limited, aud the same eye oannot be
made to see distinctly at alt distances. For all ordinary eyes, the
accommodation fails, aud vision becomes imperfect, when the object
is placed at less than six inches distance from tbe eye. But from
that point outward, the eye can adapt itself to any distance at which
light is perceptible, even to the immeasurable distances of the fixed
stars. A much greater accommodating power, however, is re-
quired for near distances than for remote, since the difference in
divergence between rays, entering the pupil from a distance of ooe

BIOHT. 488

iocb and flrom tbat of six inches, is greater than the difTerence be*
tween nx inches and a yard, or even distances which are tmmea-
snrably remote. Accordingly, near-sighted persons can see objects
distinctly when placed very near the eye; since, as their lens con-
rergea the rays of light more powerfully than nsnal, they can be
brought to a focna upon the retina, even when excessively diverg-
ent at the time they enter the eye. But diBtaot objects become
indistinct, since, however &r backward the lens is moved, the rays
are still brought to a focus and cross each other, before reaching
the retina, as in Fig. 161. Near-sighted persons, therefore, have a
limited range of accommodation, like all others, only it is confined
within short distances, owin^ to the excessi^ refracting power of
the lens.

On the other band, long-sighted persons can see remote objects
without trouble, since a very little movement of the lens will be
sufficient to adapt it for long distances ; bnt within short distances,
the divergence of the rays becomes too great, and they cannot be
brongbt to a focus.

CfavU of Vision, — Since the opening of the pupil will admit rays
of light coming from various directions, there is in front of the eye
a drcle, or space, within which luminous objects are perceived, and
beyond which nothing can be seen, because the rays, coming from
the side or from behind, cannot enter the pupil. This space, within
which external objects can be perceived, is called the "circle of
vision." But, for short distances, there is only a single point, in the
centre of the circle of vision, at which objects can be seen distinctly.
Thus, if we place ourselves in front of a row of vertical stakes or
palisades, we can see those directly in front of the eye with perfect
distinctness, but those at a little distance on each side are only per-
ceived in a confused and uncertain manner. On looking at the
middle of a printed page, in the direct range of vision, we see the
distinct outlines of the letters; while at successive distances from
this point, the eye remaining fixed, we can distinguish first only
the separate letters with confused outlines, then only the words, and
lastiy only the lines and spaces.

This is because rays of light coming into the eye very obliquely,
in a lateral direction, are not brought to their proper focus. Thus,
in Fig. 102, the rays diverging from the point o, directly in front of
the eye, fall upon the lens in such a way that they are all brought
together at x, at the surface of the retina; but those coming from b
fall upon the lens so obliquely that, for rays having an equal diver-

484

THl 9PKCIAT, SH!?9B9.

gence witli those coming from a, thcro ts more diflWrence in their
anjjl&fl of iticiiiencu, uikI of course more dilTerence id the amouat
of their refraction. They arc coniwc^ucTitly brought together more
rapidly, and on reaching the retina are dispersed over the apace y, z.

Fig. ISS.

The perfection of the eye, as a visual apparams, is wry mach
iDcreamd by the action of the iris. This organ, as we have already ■
mentioned, is a nearly vertical musculnr curtain, placed in front of
the lens, attached by its external margin to the junction of the
cornea and sclerotic, nnd pierced about its centre by the circular . H
opening of the pupil. It consists, according to most nnatomialB, of
two sets of muscular fibres — viz., the circular and the radintjng.
The circular fibres, which are much the most abundant, are arranged
in concentric lines about the inner edge of the iris, near the pupil: fl
the others are said to radiate in a scattered manner, from its central
parts to its outer margin. The action of these two sets of fibres is
lo csontract and enlarge the orifice of the pnpil. The circular fibres,
in contracting, draw together the edges of the pnpil, and so diminish
its opening; and when these arc relaxed, the radiating Gbres come
into play, and, by drawing apart the edges of the orifice, enlarge
the pupillary opening. The action of the circular fibrea, at the
same lime, is much the moat marked and important of the two.
For when the whole muscular apparatus of the eye is paralyzed
by the action of belladonnp, or by the division of the third pair of
nerves, or in the general relaxation of the mascular system at the
moment of death, the pupil is invariably dilated, probably by ibe
paasive elastiL-iiy of its tissues.

SIGHT. 4S5

Daring life, however, these different crmdttions of the pupil cor-
Kapond with the different degrees of light to which the eye is ex-
posed. In A strong light, the pupil contracts and shuts ont the
soperflaouB raya; in a feeble light, it dilates, in order to collect
into the eye all the light which can be received from the object.
This contractile and expansive movement of the pupil is a reflex
action. It is not produced by the direct impression of the light
npon the iris itself, but upon the retina; since, if the retina be
affected with complete amaurosis, or if the light be entirely shut out
from it by an opacity of the lens, no such effect is produced, though
the iria itself be exposed to the direct glare of day. From the
retina the impression is transmitted, through the optic nerve, to the
optic tubercles and the brain, thence reflected outward by the oculo-
motorias nerve to the ophthalmic ganglion, and so through the
ciliary nerves to the iris.

The pupil is subject, however, to various other nervous influences
beside the impressions of light recieived by the retina. Thus in
poisoning by opium, it is contracted ; in coma from compression of
the brain, it is dilated ; in natural sleep it is contracted, and the eye-
ball rolled upward and inward. In various mental conditions, the
pupil is also enlarged or diminished, and thus modifies the expres-
uon of the eye; and in viewing remote objects, it is generally
enlarged, while, in looking at near objects, it is comparatively con-
tracted. Bnt still, the most constant and important Ainction be-
longing to the iris is the admission or exclusion of the rays, accord-
ing to the intensity of the light.

Oar impressions of distance and solidity, in viewing external
objects, are produced mainly by the combined action of the two eyes.
¥or, as the eyes are seated a certain distance apart from each other
in the head, when they are both directed toward the same object,
their axes meet at the pmint of sight, and form a certain angle with
each other; and thia angle varies with the distance of the object.
Tbns, when the object is within a short distance, the axes of the
two eyes will necessarily bo very convergent, and the angle which
they form with each other a large one; but for remote objects, the
visual axes will become more nearly parallel, and their angle con-
sequently smaller. It is on this account that we can alwuys dis-
tinguish whether any person at a short distance is looking at tw,
or at some other object in our direction; since we instinctively
appreciate, from the appearance of the eyes, whether their visual
axes meet at the level of our own face.

486

THE 8PKCU1

In looking at a landscape, accordingly, we do not see the whole
of it distinctly at the same moment, but only thone parta to vhich
our attention is immediately directed. Thi« ia because, in the first
place, the /octw of distinct vision varies, in each eye, for diSereat
distaiiccti, as we have seen in a former paragraph, and secondly,
because both eyes con only be directed together, at one time, to
objects At a certain distance. Thus, when we sec the foreground
or the iinddle ground distinctly, the distance is vague and uncer-
tain, and when we direct our eyes more particularly to the horisou,
objects in the foreground become indistinct In this way we ap-
preciate the difference in distance between the various portions of
the landscape, as a whole. In the case of particular objects, we am
assisted also by the alteration in their individual characters; for
distance produces a dimiuutiuu, both in apparent size and ia in-
tensity of color.

Tbe combined action of the two eyes is also very valuable, for
near objects, in giving ua an idea of solidity or pro/ttUioJi. For
within a certain distance, tbe visual axes, when directed together
nt a solid object, are so convergent tlint the two eyes do not receive
the aame imago. As in Figs. 163 and 164, which represent n skoU

Fig. 153,

Fig. IM.

aa seeo by the two eyes, when placed exactly in from of tbo oh
server at the distance of eighteen inches or two feet, tbe right eye
will see the object partly on one aide, and the lcl\ eye partly oo iho
other. And by the union or combination of these two images by
the visual organs, the impression of solidity is produced.

By the employment of double pictures, so drawn as to represent

SIGHT. 487

the appearances presented to the two eyes by the same object, and
so arranged that each shall be aeeo only by the corresponding eye,
a deceptive resemblance may be produced to the actual appearance
of solid objects. This is accompllBhed in the contriTance known
as the Stereoawpe. Thus, if two pictures similar to those in Figs.
168 and 164 be so placed that one shall be seen only with the right
eye and the other with the left, the combination of the two figures
will take place as if they came from the real object, and all the
natural projections will come out in relief.

Bat Uiis e£fect is produced only in the case of objects situated
within a moderately short distance. For very remote objects, we
lose the impression of solidity, since the difference in the images on
the two eyes becomes so slight aa to be inappreciable, and we see
only a plane expanse of auiface, with sharp outlines and various
shades of dolor, but no actual projections or depressions.

The aenaibility of the retina is such that it cannot distinguish
luminous points which are received upon its surface at a very
minufe distanu from ■ each other. In this particular, the sensibility
of the retina resembles that of the skin, since we have already
found that the integument cannot distinguish the impressions
made by the points of two needles placed a very short distance
Kfrnti. The delicacy of this discriminating power, in the retina, is
.immeaiprably superior to that of the skin; and yet it has its
.iflnita, even in the nervous expansion of the eye. For if we look
'^jflfcU object which, is excessively minute, or nhich is so remote
j^i^'.4|il|Ht its apparent size is very much diminished, we lose the power
distinguishing its different parts, and can no longer perceive
-nal'ontline. This is a very diCTerent condition from that in

.^^,___ the confusion of vision arises from defect of focusing in the

-l^^-iV% *") ^^ example, in long or short-sigbtedness, or where the
^tarff^aot is placed too near the eye or too much on one side. For
' i^btm the difficnlty depends simply on its minute size or its remote-
nesi, the rays coming from the top of the object and those coming
from the bottom, are all brought to their proper focus at distinct
points on the retina — only these points are too near each other for the
retma to distinguish them apart. Consequently we can no longer
appreciate the form of the object.

For the same reason, when we mix together minute grains of a
different hue, we produce an intermediate color. If yellow and
blue be miiigled in this way, we no longer perceive the separate
blue and yellow grains, bat only a uniform tinge of green; and

488

THB SPECIAL SEySB8.

white and black granules, mixed together, produce, at a short tlin-
tance. the appearance of a continuous shade of f^ny.

ImprtaaioM, once prodnctd upon (he retina, renutin for a ihnrt time
afterward. Usually these impreiisions arc so evanescent afier the
removal of their immediate cause, and are k* soon followed by
others which are more vivid, that we do not notice their existence.
They may very readily be demonstrated, however, by swingiag
rapidly in a circle before the eyes, in a dark room, a stick lighted
at one end. As soon as the motion has attained a certain degree of
velocity, the impression produced on the retina, when the lighted
end of the stick arrives at any particular spot^ remains until it has
completed its revolution and has again reached the same point;
so that the effect thus produced upon the eye is that of a contina-
0U8 circle of light. The same fact has been illustrated by the ■
optical contrivance, known as the ThaumatTope, in which suoueasive
pictures of similar figures in different positions are made to revolve
rapidly before the eye, and thus to produce the apparent eflect of a
single Sgure in rapid motion; — since the eye fails to perceive the
intervals between the different pictures.

The sense of vision, therefore, tliruugh the impressions of light,
gives us ideas of form, size, color, position, distance, and movement.
But these ideas may also be excited by impressions derived from
an intemnt source, as well as those produced by rays coming from
without. And it is one of the most striking peculiarities of the
sense of sight that these ideal or internal impressions, which are
excited in it by various causes, are mtich more in'vid and powerful
than those of any other of the aen»e». Thus, in a dream, we of\ea nee
external objects, with all their visible peculiarities of lights color,
form, &c., nearly or quite as distinctly as when we are awake; bat
the imaginary impressions of sound, in this condition, are always
comparatively faint, and those of taste, smell, and touch, almost
entirely imperceptible. Even in a reverie, in the waking condi-
tion, when the absorption of the mind ia its own thoughts is com-
plete, and we are withdrawn altogether from outward intluencca,
we see objects which have no present existence as if they wore
netually before us. It is this Rcn.4e al.so which becomes most easily
and thoroughly excited in certain nervous disorders; as, for exam-
ple, in delirium tremens, where the patient often sees passing before
his eyes extensive and magnificent Iandscji|>e8, crowds of human
faces and Sgures, and series of towns and cities, which seem la be
depicted upon the imagination with a force and distinctness, much

HKARIKa. 489

superior to that of other delirtouA impressioDS. Sinee the sense of
right, therefore, depends less directly than the other senses apon
the actoal contact of material objects, it is also more easily thrown
into activity when withdrawn from their iufluenoe.

HXABIKO. — The sense of hearing depends upon the vibrations
excited in the atmosphere by sonoroas bodies, which are themselves
firet thrown into vibration by various canses, and which then com-
municate similar andulations to the sarrounding air. These sono-
roaa ribrations are of such a character that they cannot be directly
appredated by ordinary sensibitity, but the result of numerous and
well-directed physical experiments on this subject leaves no doubt
whatever of their existence; and when such vibrations are commu-
nicated to the auditory apparatus, they produce in it the sensation
of tound.

In the case of the aquatic animals, which pass their entire exist-
ence beneath the surface of the water, the water itself, which is
capable of vibrating in the same way, communicates the sonorous
impressions to the organ of hearing; but in the terrestrial animals,
and particularly in man, it is the atmosphere which always serves
as the medium of transmission.

The aaditory apparatus, in man and in the quadrupeds, consists,
first, of a somewhat expanded and trumpet-shaped mouth, or ex-
ttmal ear, destined to receive and ootlect the sonorous impulses
coming from various quarters. This external ear is constructed
of a cartilaginous framework, covered with integument, loosely
attached to the bones of the head, and more or less movable by
means of various muscles, which by their contraction turn its
expanded orifice in different directions. In man, the movements
of the external ear are almost always inappreciable, though the
muscles are easily demonstrated; but in many of the lower animals
these movements are exceedingly varied and extensive, and ptay a
vwj important part in the working of the auditory apparatus.

At the bottom of the external ear, its orifice is prolonged into a
tube or canal, the external aitditcry meatus, partly cartilaginous and
partly bony, which penetrates the lateral part of the temporal bone
in a nearly horizontal and transverse direction. In the human
subject, tbis canal is a little over one inch in length, and is lined
by a continuation of the external integument. The integument
toward its outer portion is beset with small hairs, and provided
with oerumiouus glands which supply a secretion of a waxy or

490

THE 8PSCIAL SErHSES.

resinous oonsistcncj. By these mcaas the passage is protected
from the accidenUil ingreaa of vnrioog foreign bodies.

Secondly, at the bottom of the external meatus the auditory pas-
sage is closed by a thin fibrous membrane, stretched across its cavity,
called the membrana ii/mpani. Upon this membrane are received the
sonorous vibrations which hare been collected by the external ear
and conducted inward by the exterual auditory meatus. Behiod
the membraua tympani ia the cavity of the midile ear, or the carity
of the tympanum. This cavity communlcatos posteriorly with tba
mastoid cells, and anteriorly with the pharynx, by a narrow passage,
lined with ciliated epithelium, and Tanoiug downward, forward and
inward, called the Eustachian Cute. A chain of small bones, the
malleus, incus, and sLupes, is stretched across the cavity of the
tympanum, and forma a communication between the merobrana
tympani on the outside, and the membrane closing the foramen
Ovale in the petrous portion of the temporal bono. All the vibra-
tioDB, accordingly, which are received by the merobrana tympani^
are transmitted by the chain of bones to the membrane of tho
foramen ovale. The tension of the membranes is regulated by two ^
small muscles, the (emor tympani and $tapttltu4 muscles, which arise B
from the bony parts in the neighborhood, and are inserted respect-
ively into (he neck of the malleus and the head of tho stapes, and
which draw these bones forward and backward upon their nrtico*
lations. H

Thirdly, behind the membrane of the foramen ovale lies the
labyrinih, or iutemal ear. This consists of a complicated cavity,
excavated in the potroua poriinn of the temporal bone, and com-
prising an ovoid central portion, the vesiihile, a double spiral otDoI,
the cochlea, and three scmicircuUir canaU, all commaoicaUng by
means of tba common vestibule. All parts of this cavity uontaio
a watery fluid, termed the perilymph. The vestibule and aemi-
circular canals also contain closed membranous sacs, suspended in
the fluid of the perilymph, which reproduce exactly the form of
the bony cavities themselves, and communicate with each other in
a similar way. These sacs are filled with another watery fluid,
the endolympb; and the terminal Blamentsof the auditory nerve
are distribnted upon the membranous sac of the vestibule and upon
the ampullie, or membranous dilfllations, at tho commencement of
the three semicircular canals. The remaining portion of the audi-
tory nerve is distributed upon the sepium between the two spiral
canals of the cochlea.

BEXRINO.

491

Tbiis, t}ie eAscntial or rundaineiiial portion of the auditory oppa-
ratus is evidently the internal ear, a caviiy, partly membranous and
partly bony, in which is distributed a uerve of special senae, the
auditory nerve, capable of appreciating sonorous impressions. The
rftcccaaory parts, on the other hand, are the chain of bones and the
'membrane of the tympanum, which commuaicate the sonorous
vibrations directly to the internal ear; and the meatus and exloraal
\T, which collect them from the atmosphere. The reception of

Fig. 269.

INAB Absit«b( A.rpjti ATca, ahAwInf •rUrsal aadlUff B«iia«, tfmf»aam,vxd lab;-

.Bunoruus impulses is therefore acouinpUshed iu a very indirect way.
For the sonorous body first communicates its vibratioos to tbe
utmosphere. By the atmosphere these vibrations are cummuiucated
to the membrana tympani. From the membraxia tympani, thi^y are
transmitted, through the chain of bones, to iho membrane of the
foratnen ovale; thence to the perilymph, or fiuid of the labyrinthic
cavity, and from the perilymph to the membranous parts of tbe
labyrinth aud the nerves which are distributed upon them.

The arrangement of the difTerent parts composing the lyvipattum
is of the greatept importance for the perfect enjoyment of the sense
of hearing. For the air on the two sides of tbe membrane of the
tympanum should be in tbe same condition of elasticity in order to
allow of the proper vibration of the membrane; and ttiis equilibrium
would be liable to disturbance if the air within the tympanum were
completely confined, while that outsido is subjected to variation-*
of barxjmetriu pressure. Dy means of the EustacliiaD tube, how-

492

Tne SPECIAL SEXSBS.

«rer, a communication is established between ihe cavity of the
tympanum snd ttie exterior, nad the free vibration of the membraud
is thus Hocurcd.

Tha exnci tennon o/Ote membmna tympam itself is also provided
for, as we have already observed, by the action of ibe two muscle*
inserted into the niulleus and the stapes. By the contraction of
the internal' muscle of the malleua, or tensor tt/m}>anif the membrane
of the tympanum is drawn inward and rendered more tense than
nsnal. The action of the siapeJtus muscle is by some thought to
relax the membrana tympani, by others to assist in the tension
both of ibis membrane and that of the foramen ovale, to which fl
the stapca IB altachcil. But there is no doubt that l>oth these mus-
itlea, by their comhined or alternate action, can regulate the tension
of the tympanic membrane, to an extraordinary degree of nicety.
and thuB increase the ease and delit-acy with which various sounds
are distinguished. For if the membrane be so put upon the stretch
that its fundamental note shall be the same with that of the sound
which is to be heani, it will vibrate more readily in consonance
with the undulations of the atmosphere, and the sound will be
more distinctly heard. On the contrary, if the membrane be loo
highly stretched, very grave sounds may not be heard at all, until
its tension is diminished to the requisite degree.

Contrary to what is sometimes asserted, the communication of
sonorous impulses to the internal ear is accomplished altog^her^by
meam of the lympantim and chain of hemes. It has been thought that
' sounds were transmitted, in many instances, directly to the internal
nlf>v^ ear by the medium of the cranial bones. This was inferred from
£rt»c ""■^'^ ^^^^ ** ^^* following. If a toning-fork, in vibration, be taken
between the teeth, its sound will appear very much louder than
§„,^i^ il:^\^ it were simply held near the external ear; and if, while it is so
• ■'■held, one of the ears he closed, the sound will appear very much

'^'^'^^^ louder on thai side than on the other. The sound will also bo beard
'^*^ - jj- jjjg tuning-fork be applied to the upper part of the cranium or
^*^J*^4a the mastoid process, with a similar increase of resonance on closing
4%. ' > - ihe ears. Finally our own voices are heard, though the ears be
lioth closed, and the sound is much louder wiih the ears closed

BEARIKQ. 493

hold the end of a vibrating tuning-furk between the teeth, we no
longer hear the sound in the vibrating extremity of the instrument
or its neighborhood, bat in the mouth and the natal fonae. It is the
vibration of the air in these passages which produces the sound;
and this vibration is communicated to the cavity of the tympanum
through Uie Eustachian tube. The apparent iocreaae of sound, also,
on closing the ears, which could not be exphtined on the supposition
that it was conducted directly through the bones of the cranium,
ia dne to the same caase. For it can easily be seen, on trying the
experiment, either with a tuning-fork held between the teeth or
simply with our own voices, that this apparent increase of sound
takes place only when the ears are closed by gentle pressure. If the
pressure be excessive, so that the integument is forced inward into
the meatus and the air in the meatus subjected to undue compres-
sion, the sound no longer appears louder in the corresponding ear,
and may even be lost altogether.

The apparent increase of sound, therefore, in snch cases, when
the ear is gently closed, is due to the fact that the meatus is thus
converted into a reverberatory cavity, by which the vibrations of
the tympanum are increased in intensity. But if the air in the
meatus be too much compressed by forcible closure, the vibrations
of the tympanum are then interfered with and the aonnd is dimi-
niahed or destroyed.

In all cases, then, it is the sonorous vibrations of the air which
produce the sound, and these vibrations are received invariably by
the membrane of the tympanum, and thence transmitted to the
internal ear by the chain of bones. The cranial bones are incapable
<^ communicating these vibrations to the labyrinth and its contents,
except very faintly and imperfectly. For common experience shows
that even the loudest and sharpest sounds, coming from without,
are almost entirely lost on closing the external eani; and our own
re^iratory and cardiac sounds, which are so easily heard as soon
as the chest is connected with the ear by a flexible stethoscope, are
entirely inaudible to us in the usual condition.

The exact function of the different parts of the internal ear is
not well nnderstood. It has been thought to be the office of the
Mfntetreu&rr canah to determine the direction from which the sono
rous impulses are propagated. This opinion was baaed upon the
curious fact that these canals, always three in number, are placetl
in auch positions aa to correspond with the three different directions
of vertical height, lateral extension, and longitudinal extension ;

494

TBS SPECIAL 9CySE3.

for one of them is nenrly vertical and transverse, anoiher vertical
ant] longitudinnl, and the third horizontal in position. The sono-
rous impulses, therefore, coming in either of these directions, would
be received b^ only one of the scTnicircular canals (by direct con-
duction through the bones of the bead) perpendicularly to ita own
plane; and an intermediate direction, it was thought^ might be
appreciated by the combined effect of the impolse apon two adja-
cent canals.

Enough has already been said, however, in regard to the oom-
mnnication of sound directly through iho bones of the head to the
internal ear, to show that this cannot be the way in which the direc-
tion of sound is ascertained. Indeed, when we hear any loud and
well-marked sound coming from a particular region, such as the
music of a military band or the whistleof a locomotive, we have only
to close the external ears to lose our perception both of the sound
and its direction. The direction of sonorous impressions is appre-
ciated in a dinereot way. In the first place, we feel that the sound
comes from one side or the other, by its making a more distinct
impression on one oar than the opposite ; and by inclining the
head slightEy in various directions, we easily ascertain whether the
sound becomes more or less acute, and so judge of its actual source.
Many of the lower animals, whose ears are very large and movable,
use this method to great extent. A horse, for example, when upon
the road, oflen keeps his cars in constant motioo, /ee/injr, as it were,
in the distance, for the origin of the various sounds which excite
bis attention.

Beside the above, we are further assisted in our judgment of the
directiou of sounds by our previous knowletlge of the looalUieis
the direction of the wind, and the manner in which the sound is
reflected by surrounding objects. When these sources of informa-
tion fail US, we are often at a loss. It is notoriously difficult, for
example, to judge of the place of the chirping of a cricket in a
perfectly closed room, or of the directiou of a bell heard on the
water in a thick log.

The sense of hearing has a much cloecr analogy with ordinary
sensibility than that of sight. Thus, in the first place, hearing is
accomplished by the direct intervention and contact of a material
body — the atmosphere; for sonorous impulses cannot be produced
in a vacuum, and we hear no sound from a bell rung under an
exhausted receiver. Secondly, tho nature of the impreseions pro-
duced by sound is such that we can olUa describe them by tbo

ON THE BEKSB8 IN OSNKRAL. 496

same terms which are applied to ordinary sensations. Thus, we
speak of sonnds as sharp and dall, piercing, smooth, or roogh ; and
we feel the impalse of a sudden and violent explosire sound, like
that of a blow upon the tympanum.

By this sense, therefore, we distinguish the quality, intensity,
pitch, duration, and direction of sonorous impulses. The delicacy
with which these distinctions are appreciated raries considerably
in different iodiridnals; and in diflerent kinds of animals there is
reason to believe that the diversity is much greater, some of them
being almost insensible to sounds which are readily perceived by
others. In man, the number and variety of tones which can usu-
ally be discriminated is very great ; and this sense, accordingly, in
Uie complication and finish of its apparatus, and the perfection and
delicacy of its action, must be regarded as second only to that of
vision.

On thk Senses nrOsNEBAL. — There are several &cts connected
with the operation of the senses, both general and special, which
are common to all of them, and which still remain to be considered.
In the first place, an impression of any kind, made upon a sensi-
tive oi^n, remains for a time after the removal of its excUmg cause.
We have already noticed this in regard to the senses of taste, smell,
and sight, but it is equally true of the hearing and the touch.
Thus, if the skin be touched with a piece of ice, the acute sensa-
tion remains for a few seconds, whether the ice be removed or not
For the higher order of the special senses, the time during which
this secondary impression remains is a shorter one. In the case of
hearing, however, it has been measured with a tolerable approach
to accuracy ; for it has been found that, if the sonorous undulations
follow each other with a greater rapidity than sixteen times per
second, they become fused together into a continuous sound, pro-
ducing upon the ear the impression of a musical note. The varying
pitch of the note depends upon the rapidity with which the vibra-
tions succeed each other. When the succession of vibrations is
very rapid, a high note is the result, and when comparatively slow,
a low note is produced; but when the number of impulses falls
below nxteen per second, we then begin to perceive the distinct
vibrations, and so lose the impression of a continuous note.

All the senses, in the second place, become accustomed to a con-
tmued impretsum, so that they no longer perceive its existence.
Thus, if a perfectly uniform pressure be exerted upon any part of

496

TFIS aPBCI&L SENSES.

the boily, t)ie comprei^slng substance after a time fails to excite tiny
Ben»aLtoii iu the skin, and we remain uncoascious of its existenoe.
In order to attract our notice, it is then oeoeesary to increase or
diminish the pressure; while, so long oa this remains uniform, no
effect is perceived. But if, after the skin has thus become accos-
tomed to its presence, the foreign body be suddenly removed, oar
attention m then immediately excited, and we notice the absence of
an impression, in the same way as if it were a positive sensation.

We all know how rapidly we become habituated to odors, whether
ftgreeftble or diftagrecahle in their nature, in the confined air of a
close apftrtment; although, on first entering from without our
attention mny have been attracted by them in a very decided
manner. A continuous and uniform sound, also, like the steady
rumbling of carriages, or the monotonous hissing of boiling water,
becomes after a time inaudible to us; but as soon as the sound
ceases, we notice the alternlion, and our attention is at once excited.
The senses, accordingly, receive their siiraulaa more from the varia-
tions and contrasts of external impressions, than from these impres-
sions themselves.

Another important particular^ in regard to the senses, is their
cajmciiy/or eJttcation. The proofs of this are too common and too
apparent to need more than a simple allusion. The touch may be
so trained that the blind may read words and sentences by its aid,
in raised letters, where an ordinary observer would hardly detect
anything more than a barely distinguishable inequality of surface.
The educated eye of the artist, or the naturalist, will distingaiah
variations of color, size, and outline, altogether inappreciable to
ordinary vision ; and the seuses of taste and smell, in those who are
io the habit of examiDing wines and perfumes, acquire a similar
superiority of discriminating power.

In these instances, however, it is not probable that the organ of
sense itself becomes any more perfect in organization, or more
susceptible to sensitive impressions. The increased functional
power, developed by cultivation, depends rather upon the greater
delicacy of the perceptive and discriminaiive faculties. It is a mental
and not a physical superiority which gives the painter or the
naturalist a greater power of distinguishing colors and outlines,
and which enables the physician to detect nice variations of quality
in the sounds of the heart or the respiratory murmur of the lungs.
The impressions of external objects, therefore, in order to produce
their complete effect, must first be received by a sensitive pppa-

02r THE 8ENSBS IN GENERAL. 497

ratas, vfaich ia perfect in organizatioD and fanotional activity;
and, secondly, these impressions must be subjected to the action of
an intelligent perception, by which their nature, source and rela-
tions may be fully appreciated.

That part of the nervous system which we have hitherto
studied, viz^ the cerebro-spinal system, consists of an apparatus of
nerves and ganglia, destined to bring the individual into relation
with the external world. By means of the special senses, he is
made cognizant of sights, sounds, tastes, and odors, by which he
is attracted or repelled, and which guide him in the pursuit and
choice of food. By the general sensations of touch and the volun-
tary movements, he is enabled to alter at will his position and
location, and to adapt them to the varying conditions under which
he may be placed. The great passages of entrance into the body,
and of exit from it, are guarded by the same portion of the nerv-
ous system. The introduction of food into the mouth, and its
passage through the oesophagus to the stomach, are regulated by
the same nervous apparatus; and even the passage of air through
the larynx, and its penetration into the lungs, are equally under
the guidance of sensitive and motor nerves belonging to the
oerebro-spinal system.

It will be observed that the above functions relate altogether
either to external phenomena or to the simple introduction into the
body of food and air, which are destined to undergo nutritive
changes in the interior of the frame.

If we examine, however, the deeper regions of the body, we find
located in them a series of internal phenomena, relating only to
the substances and materials which have already penetrated into
the frame, and which form or are forming a part of its structure.
These are the purely vegetative functions, as they are called; or
those of growth, nutrition, secretion, excretion, and reproduction.
These functions, and the organs to which they belong, are nob
under the direct influence of the cerebro-spinal nerves, but are
regulated by another portion of the nervous system, viz., the
^'ganglionic system;" or, as it is more commonly called, the "sys-
tem of the great sympathetic."

498

SYSTEM OF THS GREAT 8YUPATBSTIC.

CHAPTER VII.

SY8TBM OF THE GBEAT SYMPATHETIC.

The sympathetic syBtem consists of a double clinin of nerToos
gaoglia, ruDniog from the anterior to the posterior extremity of the
boJy, alc^ng the front and sides of the spinal column, and connected
with each other by slender longitudinal Jilnments. Each ganglion
is reinforced by a motor and Hcnsitivo filament derived from the
cerebro-spinnl system, and thus the organs under its influence arc
brought indirectly into communication with external objecta and
pbenomena. The nerves of the great sympatlietic are distributed
to organs over which the conscioutine«^s and iho will have no itnioe-
diate coalrol, as the intestine, kidneys, heart, liver, &a.

The first sympathetic ganglion in the head is the opfithalmt'c g<m-
glion. This ganglion is situated within the orbit of the eye, on the
outer aspect of the optic nerve. It communicates by slender fila-
ments with the carotid plexus, which forms the continuation of the
sympathetic system from below; and rcccivea a motor root from
the oculo-motoriua nerve, and a sensilire root from the ophthalmic
branch of the tlflh pair. Its filaments of distribution, known as the
"ciliary nerves," pass forward upon the eyeball, pierce the sclerotic,
and Unally terminate in the iris.

The next division of the great sympathetic in the head is tb«
s}/fiaiO-j)a{atiu€ ganr/Utm, situated in the spheno-maxillary fossa. It
oommunicutuB, like the preceding, with the carotid plexus, and
receives a motor root from the facial nerve, and a sensitive root
from the superior maxillary branch of the fifth pair. Its filaments
are distributed to the levator palati and azygos uvulta muscles, aod
to the mucous membrane about the posterior nares.

The third sympathetic ganglion in the head la the submaxillary,
situated upon the submaxillary gland. It communicAtes with the
superior cervical ganglion of the sympathetic by filaments which
accompany the facial and external carotid arteries. It derives its
sensitive filaments from the lingual branch of the filUi pair, and its

8TSTBM 07 TH1

499

motor filaments from the facitvl nerve, by means of ibe chorda
tympani. Its bmnches of distribution {>ass to the aides of the tongue
and to the siibma?:illary and sublingual glands.

The lost BympathcCic ganglion ia the head ia tho otic ffanglum.
Tt is situated ju!*t beneath the

base of the skull, on the inner "*■ *^"

«de of tho third division of
the fifth pair. It sends fila-
ments of eommuDicalioD to
the carotid plexus; and re-
ceives a motor root from tho
facial nerve, and a sensitive
root from the inferior maxil-
lary division of the Hilb pair.
Its branches arc sent to tho
ioterDal muscle of the mal-
leus in the middle ear (tensor
tjmpani), and to the mucous
membrane of the tympanum
and Kustachian tube.

The coDtinuatioD of the
sympathetic nerve ia the neck
consists of two and some-
times three ganglia, the sa-
perior, middle, aod inferior.
These ganglia commiiniouto
with each other, and also
with the anterior branches
of the cervical spinal nerves.
Their filaments fullov the
OOtirse of the carotid artery
and its branches, covering
tbem with a network of inter-
lacing fibres, aod are finally
distributed to the substance of
the thyroid gland, and to the
walls of the larynx, tmchco,

pharynx, and oesophagus, lly the BUpenor, middle, and inferior
oirdiao nerves, they also supply sympathetic fibres to the cardiac
plexuses and to the substance of the heart.

In the chest, the ganglia of the sympathetic nerve are situated on

Vf;

Cnnroe »nd dl«lrll)aU«i *r Ui* Obiat 8T»Hf

500

SYSTEM OP THB ORBAT SYMPATHETIC.

each side tbe spinal column, just over the heads of the ribs, with
which they accordingly correspond in number. Their ooromuni-
cations with the intercostftl nerves are double; each sympathetic
^nglion receiving two 61aments from the intercostal nerve next
above it. The filaments originating from tho thoracic ganj;lia ore
diaiributcd upon the thoracic aorta, and to the lungs and oesophagus.

In the abdomen, the continuation of the sympathetic aystcm con-
fiistii principally of the ag^frcgatiun of ganglionic enlargements
situated upon the cceliac artery, known as the aanilunar or caliac
ganglion. From this ganglion a multitude of radiating and inoscu-
lating branches are sent out, which, from their diverging course and
their common origin from a central mass, are termed the "solar
plexus.'' From this, other diverging plexuses originate, which
accompany the abdominal aorta and its branohes, and are distri*
butcd to the stomach, small and large intestine, spleen, pancreas,
liver, kidneys, snpra-renal capsules, and internal organs of gene-
ration,

Beside the above ganglia there are in the abdomen four other
pairs, situated in front of the lumbar vertebra-, and having similar
connections with those occupying the cavity of the cheat. Thdr
filnments join the plexuses radiating from the semilunar ganglion.

In the pelvis, the sympathetic syatem is continued by four or five
pairs of ganglia, situated on the anterior asgieut of tho sacrum, and
terminatitig, at the lower extremity of tbe i^plnal column, in a single
ganglion, the "ganglion impar," which is probably to bo regarded
aa a fusion of two separate ganglia.

The entire sympathetic series is in this way composed of nume-
rous small ganglia which are connected throughout, first, with each
other; secondly, with the cerebro-spinal system; and thirdly, with
the internal viscera of the body.

The properties and functions of the great sympathetic have been
less fiucuessfully studied than thuse of the cerebrospinal system,
owing to the anatomical difBculiies in the way of reaching and
operaiing upon this nerve for purposes of experiment. The cerebro-
spinal axis and its nerves arc easily exported and subjected to exami*
nation. It is also easy to isolate particular portions of this system,
and to appreciate the disturbances of sensation and motion conse-
quent upon local lesions or irritations. The phenomena, further-
more, which result from exi>enments upon this part of tbe nervous
apparatus, are promptly protluced, are well-marked in character,
and are, as a general rule, readily understood by the expert meater.

8T8TEH or THE GREAT SYMPATHETIC. 501

On the other band, the principal part of the sympathetic system is
sitaated in the interior of the cheat and abdomen; and the mere
operation of opening these cavities, so as to reach the ganglionic
ceotrea, causes such a disturbance in the functions of vital organs,
and such a shock to the system at large, that the results of these
experiments have been always more or less confused and unsatis-
factory. Furthermore, the Qonnections of the sympathetic ganglia
with each other and with the cerebro-spinal axis are so numerous
and so scattered, that these ganglia cannot be completely isolated
without resorting to an operation still more mutilating and injuri*
ous in its character. And finally, the sensible phenomena which
are obtained by experimenting on the great sympathetic are, in
the majority of cases, slow in making their appearance, and not
particularly striking or characteristic in their nature.

Notwithstanding these difSculties, however, some facta have been
ascertained with regard to this part of the nervous system, which
give us a certain degree of insight into its character and functions.

The great sympathetic is endowed both with sensibility and the
power of exciting motion; but these properties are less active
here than in the cerebro-spinal system, and are exercised in a dif-
ferent manner. If we irritate, for example, a sensitive nerve in
one of the extremities, or apply the galvanic current to the poste-
rior root of a spinal nerve, the evidences of pain or of reflex
action are acute and instantaneous. There is no appreciable inter-
val between the application of the stimulus and the sensations
which result from it. On the other hand, experimenters who have
operated upon the sympathetio ganglia and nerves of the chest and
abdomep find that evidences of sensibility are distinctly manifested
here also, but much less acutely and only after somewhat prolonged
application of the irritating cause. These results correspond very
closely with what we know of the vital properties of the organs
which are supplied either principally or exclusively by the sym-
pathetic; as the liver, intestine, kidneys, &c. These organs are
insensible, or nearly so, to ordinary impressions. We are not con-
scious of the changes and operations going on in them, so long as
these changes and operations retain their normal character. But
they are still capable of perceiving unusual or excessive irritations,
and may even become exceedingly painful, when in a state of in-
flammation.

There is the same peculiar character in the action of the motor
nerves belonging to the sympathetic system. If the facial or hypo-

STSTEM OF THB OBEAT 8TMPATHBTT0.

glossal, or the anterior root ot a spinal cervo be irritated, t1)c con-
vulsiivo tnovernent which follows is instantaneous, violent, and only
momentary in its duration. But if the B«milunar ganglioti or its
nerves be subjected to a similar experiment, no immediate effect u
produced. It is only after a few seconds tliat a slow, rermicalar,
progressive contraction takes place in tbo corresponding part of the
intestine, which continaes for some tiine after the exciting caoae
has been removed.

Morbid changes taking place in organs supplied by ih© aympa-
tbetic present a similar peculiarity in the mode of their produc>
tion. If the body be exposed to cold and dampness, for example,
congestion of the kidneys shows itself perhaps on the following
day. Inflammation of any of the internal organs is very rarely
established within twelve or twenty-four hours after the application
of the exciting cause. The internal processes of nutrition, together
with their derangements, which are regarded as especially under
the control of the great sympathotic, always require a longer time
to be influenced by incidental causes, than those which are regulated
by the nerves and ganglia of the cerebrospinal system.

In the head, the sympathetic has a close and important connec-
tion with the exercise of the special senses. This Is illustrated
more particularly, in the case of the eye, by its influence over the
alternate expansion and oontraction of the pupil. The ophthalmic
ganglion sends off a number of ciliary nerves, which are distributed
to the iris. It is connected, as we have seen, with the remaining
sympathetic ganglia in the head, and receives, beside, a sensitive
root from the opbtbalmic branch of the flfth pair, and a motor root
from the ooulo-raotorius. The reflex action by which the pupil
contracts under a strong light falling upon the retina, and expands
under n diminution of lightj tabes place, accordingly, through this
ganglion. The impression conveyed by the optic nerve to the
tubercula quadrlgcmlaa, and reflected outward by the fibres of
the oculo-motorius, is not transmitted directly by the last named
nerve to the iris; but passes flrst to the ophthalmic ganglion, and
ia thence conveyed to its destination by the ciliary nerves.

The reflex movements of the iris exhibit consequently a some-
Trhnt sluggish character, which indicates the intervention of a part
of the sympathetic system. The changes in the siae of the pupil
do not take place instantaneously, with the variation In the amount
of light, but always require an appreciable Interval of time. If
we pass suddenly from a bnlliaQtly lighted apartment into a dark

8TSTBM OF THE GREAT STM PATHETIC. 603

room, we are anable to distinguish surroanding objects until a
oertain time has elapsed, and the expansion of the pupil has taken
place; and vision eveo continues to grow more and more distinct
for a considerable period afterward, as the expansion of the pupil
becomes more complete. Again, if we cover the eyes of another
person with the hand or a folded cloth, and then suddenly expose
them to the light, we shall find that the pupil, which is at first
dilated, contracts somewhat rapidly to a certain extent, and af^r*
ward oontinaes to diminish in size during several seconds, until the
proper equilibrium is fairly established. Furthermore, if we- pass
suddenly from a dark room into the bright sunshine, we are imme-
diately conscioQs of a painful sensation in the eye, which lasts for
a considerable time; and which results from the inability of the
pupil to contract with sufficient rapidity to shut out the excessive
amount of light. All such exposures should be made gradually,
so that the movements of the iris may keep pace with the varying
quantity of stimulus, and so protect the eye from injurious impres-
sions.

The reflex movements of the iris, however, though accomplished
through the medium of the ophthalmic ganglion, derive their
original stimulus, through the motor root of this ganglion, from
the ocnlo-motorius nerve. For it has been found that if the oculo-
motorius nerve be divided between the brain and the eyeball, the
pupil becomes immediately dilated, and will no longer contract
under the influence of light. The motive power originally derived
from the brain is, therefore, in the case of the iris, modified by
passing through one of the sympathetic ganglia before it reaches
its final destination.

An extremely interesting fact in this connection is the following.
Of the three organs of special sense in the head, viz., the eye, the
nose, and the ear, each one is provided with two sets of muscles,
superficial and deep, which together regulate the quantity of stimu-
lus admitted to the organ, and the mode in which it is received.
The superficial set of these muscles is animated by branches of the
facial nerve; the deep-seated or internal set, by filaments from a
sympathetic ganglion.

Thus, the front of the eyeball is protected by the orbicularis and
levator palpebrs superioris muscles, which open or close the eye-
lids at will, and allow a larger or smaller quantity of light to reach
the cornea. These muscles are supplied by the oculo-motorius and
facial nerves, and are for the most part voluntary in their action.

S04

SYSTEM OP THE ORBAT STMPATHBTIC.

The iris, on the other hand, is a more ilcvply seated muscular
curtain, which regulates the quantity of light admitted through the
pupil. There is also the ciliary muscle, which regulates the position
of the cryntalline lens, and secures a correct focusing of the light,
at difTcreiit distances. Buth these muscles are supplied, as we have
seen, by fikinents from the ophthalmic ganglion, and their moTfl
raents are involuntary in character.

In the olfactory apparatus, the anterior or superficial set
muscles are the compressors and elevators of the alai nasi, which
are animated hy tltamcnts of iho facial nerve. By their action,
odoriferous vapors, when faint and delicate in their character, are
snaffcd up and directed into the upper part of the nasal passages,
where they come in contact with the most sensitive portions of the
olfactory membrane; or, if too pungent or disagreeable in flavur,
ftro excluded from entrance. Tlu'-sc muscles are not very im-
portant or active in the human subject-, but in many of the lower
iinimals with a mure active and powerful sense of smell, as, for
example, tlie carnivora, they may be seen to play a very importaut
part in the mechanism of olfaction. Furthermore, the levators and
depressors of the velum palati, which are more deeply situated,
serve to open or close the orifice of the posterior nares, and accom*
plish a similar office with the muscles already named in front The
levator palati ami azygos uvuliu muscles, which, by their action,
tend to close the posterior nares, are supplied by ^laments from the
sphenopalatine ganglion, and are involuntary in their character.

The ear has two similar sets of muscles, similarly supplied. The
first, or superficial set, are those moving the external ear, viz., the
anterior, 3U]icrior, nnd posterior auricularcs. Like the muscles of
the anterior nares, they are comparatively inactive in man, but in
many of the lower animals are well developed and important. lo
the horse, the deer, tlie sheep, &a., they turn the ear iu various
directions so as to catcli more distinctly faint and distant sounds^ or
to exclude those which are harsh and disagreeable. These moaoles
arc suppliitd by filftments of the facial nerve, and arc voluntary in
their action.

The deep-seated set are the muscles of the middle ear. In order
to understand their action, wo must recollect that sounds are irans-
mittod from the external to the middle ear through the membrane
of the tympanum, which vibrates, like the head of a drum, on
rccetving sonorous impulses from without.

The nietnhrane of the tympauum, accordingly, which is ao elastiu

STBTEU OF THB OBSAT SYUPATHBTIC. 506

sheet, atretched across the passage to the internal ear, may be made
more or less sensitiTe to sonoroas impressions by varying its con-
dition of tension or relaxation. This condition is regulated, as we
have already seen, by the combined action of the two muscles of
the middle ear, viz^ the tensor tympani and the stapedius. The
first named muscle, the action of which is perfectly well understood,
is supplied with nervous filaments from the otic ganglion of the
sympathetic. By its contraction, the handle of the malleus is drawn
inward, bringing the membrana tympani with it, and putting this
membrane upon the stretch. On the relaxation of the muscle, the
chain of bones returns to its ordinary position, by the elasticity of
the neighboring parts, and the previous condition of the tympanic
membrane is restored. This action, so far as we can judge, is purely
involuntary. But the stapedius muscle is separately supplied by a
minute branch of the facial nerve. It is probable that this arrange-
ment enables us to make also a certain degree of voluntary exer-
tion, in listening intently for faint or distant sounds.

Id all these instances, the reflex action taking place in the
deeper seated muscles, originates from a sensation which is con-
veyed inward to the cerebro-spinal centres, and is then transmitted
outward to its final destination through the medium of one of the
sympathetic ganglia.

Another very striking fact concerning the sympathetic relates to
the changes produced by its division, in the nutritive processes of
the parts supplied by it. One of the most important and remark-
able of these changes is an elevation of temperature in the affected
parts. If the sympathetic nerve be divided on one side of the neck,
in the rabbit, cat, or dog, an elevation of temperature begins to be
perceptible on the corresponding side of the head in a very short
time. In the cat, we have found a very sensible difierence in tem-
perature between the two sides at the end of five or ten minutes;
and in the rabbit, at the end of half an hoar. A vascular conges-
tion of the parts also takes place, which may be seen to great
advantage in the ear of the rabbit, when held up between the eye
and the light. The elevation of temperature, in these cases, is very
perceptible to the touch, and may be also measured by the thermo-
meter. Bernard* has found it to reach 8° or 9° F. The elevation
of temperature and congested state of the parts are sometimes found
to be diminished by the next day, and afterward disappear rapidly.
Occasionally, however, they last for a long time. Bernard {op. cit.)

' Becb«rctiel exp^rimeut&led sar le Onnd Sympatbiquu. F&rin, 1854.

506

SYSTEM OP THE OBXAT SYMPATHETIO.

has seen the unnatural tcmporaturc of the affcoted parts remain, in
ihe rabbit, from fifteen to eighteen days, and in the dog for two
months. Where the superior cervical ganglion baa been extirpated,
he has even found the above appearances to coDtioue, in the dog, for
n year and a half. They may also, according to the same aatbonty,
be reproduced several times in the flame animal, by repeated divi-
liioiis of the sympathetic aerve.

The above efiect is due to a peculiar modiflcaLioo in the nuth'
tlon of the nfiected parts, which ha8 aomo analogy with inflamma-
tion. The unnatural heat, the congestion, and the increased sensi-
bility which are present, all serve to indicate a certain resemblance
between the two oonditious. Konc of the more serious consequenoea
of inftamniation, however, sucli as oedema, exudation, sloughing or
ulceration, have ever been known to follow from this operation;
iind the term inflammation, accordingly, cannot properly bo applied
to its results.

UivisLon uf the syinpathetic nerve in the middle nf the neck
has also a very singular and instantaneous effect on the mujKiuUr
apparatus of the eye. Within a very few seconds after the above
operation has been performed upon the cat, the pupil of the cor-
responding eye bcuomes strongly contractei), and rotnains in that
condition. At the t<amo time the third eyelid, or " nictitating mem-
brane," with which these animals are provided, is drawn partially
ov«r the cornea, and the upper and lower eyelids also approxi-
mate very considerably to eacb otber; so that all the apertures

guarding the eyeball are very
Fig. 1«7. perceptibly narrowed, and the ex-

pression of the face on that side ts
altered in acorrespoading degree.
This etTect upon the pupil bos
been explained by supposing tbe
circular fibres of the iris, or the
constrictors of the pupil, to be
flnimatod exclusively by ncrvoos
filaments derived from the oculo-
motorius; and the radiating fibres,
or the dilators, to be supplied by
the aympathetic. Accordingly,
while division of the oculo-mo-
turious would produce dilatation of the pupil, by paralysis of the
circular fibres only, division of the sympalhetic would be fol-

CAT,aa>r tMtliia of ihs rlfhl >]rinp*ih0tlD.

STaTBlf OF THE GREAT SYlfPATBETIC. 607

lowed by ezclasire paralysis of tbe dilators, and a permanent
coDtractioD of the pupil would consequently take place. The
above explanation, faoweTer, is not a satis&ctory one; since, in
the first place, dirision of the oculo-motorius, as the experiments of
Bernard have shown,' does not by itself produce complete dilata-
tion of tbe papil; and, secondly, after division of the sympathetic
nerve in the cat, as we have already shown, not only is tbe pupil
contracted, but both the upper and lower eyelids and tbe nictitating
membrane are also partially drawn over the cornea, and assist in
excluding the light. The last-named effect cannot be owing to any
direct paralysis, from division of the fibres of the sympathetic. It
is more probable that the section of this nerve operates simply by
exaggerating for a time the sensibility of tbe retina, as it does that
of the integument ; and that the partial closure of the eyelids and
pupil is a secondary consequence of that condition.

It will be remembered that in describing the inflammation of the
eyeball, consequent upon section of the fifth pair of nerves, we
found that there were reasons for believing this effect to be due
to injory of certain sympathetic fibres which accompany the fifth
pair. If the fifth pair in fact be divided at tbe level of tbe Cas-
serian ganglion, where it is joined by sympathetic fibres from tbe
carotid plexus, or between this ganglion and the eyeball, a destruc-
tive inflammation of the organ follows. But if the section be made
behind tbe ganglion, so as to avoid the filaments of communication
with the sympathetic, no inflammatory change takes place. If this
&ct be really owing to the presence of sympathetic fibres which
accompany the fifth pair, it indicates a remarkable difference in the
eflfects of dividing the sympathetio near the eyeball and at a dis-
tance from it; since no real inflammation of tbe eyeball or its
appendages is ever produced by division of this nerve in the middle
of the neck, but only the elevation of temperature and increase of
aensibility which have been already described.

The influence of the sympathetic nerve and the consequences
c^ its division upon the thoracic and abdominal viscera have been
only very imperfectly investigated by experimental methods. It
nndonbtedly serves as a medium of reflex action between tbe sensi-
tive and motor portions of the digestive, excretory, and generative
apparatuses; and it is certain that it also takes part in reflex actions

' L09OIU snr U Phjiiologie et U Patholagia da S/alfems norrsuz, Paris, 1S6S,
vol. ii. p. 203.

SYSTEM OF THE OREAT aTMPATUETIO.

in which the ccrebro -spinal system is at ihe same time intcmted.
There are accordingly three different kinds of reflex action, Inking
place wliolly or partially through the sympathetic ayatem, vrhiL-h
may he observed to occur in the living body.

lat. Reflex actions taking pluoe/rom the internal organs, through Oie
sijmpathetic and ctrehro-spinal ii/stcms, to the voluntary muscles and
sensitive «vr/ac».— The convulsions of young children are often
owing to the irritation of undigested food in the iatestinal canal.
Attacks of indigestion arc also known to prorluco temporary amaa-
rosia, doable vision, strabismus, and even hemiplegia. Nausea, and
a diminished or capricious appetite, are often prominent symptoma
of early pregnancy, induced by the peculiar coaditioo of the uterine
mucous membrane.

2d. Rejltx aetiojis talcing place from ihe sensitive stirfaeeB, through
the eerebro- spinal and sympathetic systems, to tlie involuntary muscles
and secreting organs. — Imprudent exposure of the integument to
cold and wet, will oflen bring on & diarrhoea. Mental and moral
impressions, conveyed through the special senses, will afiect the
motions of the heart, nnd disturb the processes of digestion and
secretion. Terror, or an absorbing interest of any kind, will pro-
duce a dilatation of the pupil, and communicate in this way a peoa-
liarly wild and unusiial exprcstiioD to thceyc. Disagreeable sights
or mlora. or even unpleasant occurrences, are capable of hastening
or arresting the menstrual discharge, or of inducing premature
delivery.

8d. lieflex actions taking place through the ai/mpathelie system from
one part of the tJitemai organs to another. — The contact of food with
the mucous membrane of the small intestine excites a pcrisialtjo
movement in the masculnr coat. The mutual action of the diges*
tive, urinary and internal generative organs upuu each other takea
place through the medium of the sympatbetio ganglia and their
nerves. The variations of the capillary circulation in diOerent
abdominal viscera, corresponding with the state of activity or re-
pose of their associated organs, are to be referred to a similar nerv-
ous influence. These phenomena are not accompanied by any
consciousness on the pnri. of the individual, nor by any apparent
intervention of the cerebro spinal system.

SECTION III.
REPRODUCTION.

CHAPTER I.

ON THE NATURE OP REPRODUCTION, AND THE
ORIGIN OP PLANTS AND ANIMALS.

The process of reproduction is the most characteristic, and in
many respects the most interesting, of all the phenomena presented
by organized bodies. It includes the whole history of the changes
taking place in the organs and functions of the individual at suc-
oessive periods of life, as well as the production, growth, and de-
velopment of the new germs which make their appearance by
generation.

For all organized bodies pass through certain well defined epochs
or phases of development, by which their structure and functions
undergo successive alterations. We have already seen that the
living animal or plant is distinguished from inanimate substances
by the incessant changes of nutrition and growth which take place
in its tiraues. The muscles and the mucous membranes, the osse-
ons and cartilaginous tissues, the secreting and circulatory organs,
all incessantly absorb oxygen and nutritious material from with-
out, and assimilate their molecules; while new substances, produced
by a retrogressive alteration and decomposition, are at the same
time excreted and discharged. Those nutritive changes correspond
in rapidity with the activity of the other vital phenomena; since
the production of these phenomena, and the very existence of the
vital functions, depend upon the regular and normal continuance
of the nutritive process. Thus the organs and tissues, which are
always the seat of this double change of renovation and decay,
retain nevertheless their original constitution, and continue to be
capable of exhibiting the vital phenomena.

ElO

KATUBB OF BEPRODUCTIOX.

The above changes, however, are not in reality the only ones
which tfike place. For although the structure of the body and (he
composition of its constituent parts appear to be maintained in an
unaltered condition, by the nutritive process, from one moment to
another, or from day to day, yet a comparative examination of
them at greater iniervals of time will show that thia is not pre-
cisely the case; but that the changes of nutrition are, in point of
fact, progressive as well as momentary. The compoeilion and pro-
perties of the skeleton, for example, are not the same at the age of
twenty-five that they were at fiftuca. At the latter period it con*
tainn more calcareous and leas organic matter than before; and its
solidity is accordingly increased, while its elasticity is diminished.
Even the anaivtny of the bones alters in an equally gradual manner ;
the medullary cavities enlarging with the progress of growth, and
the cancellatotl tissue becoming more open and spongy in texture.
We have already noticed the difterence in the quantity of oxygen
and carbonic acid inspired and exhaled at dificreut ages. The
muscles, also, if examined af\er the lapse of some years, are found
to be less irritable than formerly, owing to a slow, hut steady nod
permanent deviation in their intimate constitution.

The vital properties of the organs, therefore, change with their
varying structure; and o. time comes at last when they are per-
ceptibly less capable of performing their original functions than
before. This alteration, being dependent on the varying activity of
the nutritive process, continues necessarily to increase. The very
exercise of the vital powers is inseparably conuected with the sub-
seqiiuiit alteration of the organs employed in them ; and the func-
tions of life, therefore, instead of remaining indefinitely the same,
pass through a series of successive changes, which finally termiDate
in their complete cessation.

The history of a living animal or plant is, therefore, a history of
successive epochs or phases of existence, in each of which the struc-
ture and functions of the bo«ly difler more or less from those in
every other. Every living being has a definite term of life, through
which it passes by the operation of an invariable law, and which,
at some regularly appointed time, comes to an end. The plant
germinates, grows, blossoms, bears fruit, withers, and decays. The
animal is born, nouriahed.and brought to maturity, after which he
retrogrades and dies. The very commencement of existenoo, by
leading through itn successive intermediate stages, conducts at last
necessarily to its own termination.

NATCBK OF BEPBODCCTION. 611

But while individual orgsniama are tliuscoDstantly perishing and
disappearing from the stage, the particular kind, or tpeciet, remains
in existence, apparently without any important change in the cha-
racter or appearaDce of the organized forms belonging to it. The
horse and the ox, the oak and the pine, the different kinds of wild
and domesticated animals, even the different races of man himself,
have remained without any essential alteration ever since the earliest
historical epochs. Yet daring this period innumerable individuals,
belonging to each species or race, must have lived through their
natural term and successively passed out of existence. A species
may therefore be regarded as a type or class of organized beings, in
which the particular forms or structures composing it die off con-
stantly and disappear, but which nevertheless repeats itself from
year to year, and maintains its ranks constantly full by the regular
accession of new individuals. This process, by which new organ-
isms make their appearance, to take the place of those which are
destroyed, is known as the process of reproduction or ger^ration. Let
us now see in what manner it is accomplished.

It has always been known that, as a general rule in the process
of generation, the young animals or plants are produced directly
from the bodies of the elder. The relation between the two is that
of parents and progeny ; and the new organisms, thus generated,
become in turn the parents of others who succeed them. For this
reason wherever such plants or animals exist, they indicate the
previous existence of others belonging to the same species; and if
by any accident the whole species should be destroyed in any par-
ticular locality, no new individuals could be produced there, unless
by the previous importation of others of the same kind.

The commonest observation shows this to be true in regard to
those animals and plants with whose history we are more familiarly
acquainted. An opinion, however, has sometimes been maintained
that there are exceptions to this rule; and that living beings may,
under certain circumstances, be produced from inanimate substances,
without any similar plants or animals having preceded them ; pre-
senting, accordingly, the singular phenomenon of a progeny without
parents. Such a production of organized bodies is known by the
name of spontaneoiu generation. It is believed by the large majority
of physiologists at the present day that no such spontaneous gene-
ration ever takes place; but that plants and animals are always
derived, by direct reproduction, from previously existing parents
of the same species. As this, however, is a question of some ini-

512

KATURG OF REPRODVCTIOH.

portance, and one which has been frequently discussed in works on
physiology, we shall proceed to pass in review the facte which have
been adduced in favor of the occurrence of spoDtaneoQS geoeraUoo,
as well as those which would lead to its disproval and rejection.

It is evident, in the Srst place, that many apparent instaneea of
spontaneous generation are found to be of a very different character
as soon as they are subjected to a critical examination. Thus grass-
hoppers and beetles, earthworms and crayfish, tlio swarms of minute
iaaocts that fill the air over the surface of stagnant pools, and even
frogs, moles, and lizards^ have been suppoaed in former times to be
generated directly from the earth or the atmosphere; and it was
only by iavestigating carefully the natural history of these animala
that they were ascertained to bo produced in the ordinary manner
by generation from [larenis, and were found to continue the repro-
duction of their species in the same way. A still more striking
instance is furnished by the production of maggots in putrefying
meat, vegetables, flour paste, fermenting dung, iua. If a piooe of
meat be exposed, for example, and allowed to undergo the prooeas
of putrcfnctton, at the end of a few days it wilt be found to contain
a tDultttude of living maggots, which feed upon the decomposing
flesh. Now these maggots are always produced under the aame
conditions of warmth, moisture and exposuro, and at the same stage
of the putrefactive process. They are never to be found in fresh
meat, nor, in fact, in any other situation than the one just mentioned.
They appear, consequently, without any similar individuals having
existed in the same locality ; and considering the regularity of their
appearance under the given conditiona, and their absence elsewhere,
it has been believed that they were spontaneously generated, under
the influence of warmth, moisture, and the atmosphere, from the
decaying orgauic eubatauces.

A little examination, however, discovers a very simple solution
of the fureguing difliculty. On watching tho e-xpoetcd animal or
vegetable substances during the earlier periods of their decompo-
sition, it is found that Certain species of flies, attracted by the odor
of the decaying inuterial, hover round it and de[)o«it tbeir ^gs
upon its Burface or in its interior. These eggs, hatched by the
warmth to which they are exposed, produce the maggots; which
are simply the young of the winged insects, and which after a time
become transformed, by the natural progress of development, into
perfect insects similar to their parenia. The difficulty of acoount-
ing for the presence of the maggots by generation, therefore, de-

INFUSORIAL ANIMALCULES. 618

peoda simply od the fact that they are different in appearance From
the parents that prodace them. This difference, however, is merely
a temporary one, corresponding with the difference in age, and dis-
appears when the development of the animal is complete; just as
the yonng chicken, when recently hatched, has a different form and
plumage from those which it presents in its adult condition.

Nearly all the causes of error, in fact, which have suggested at
various times the doctrine of spontaneous generation, have been
derived from these two sources. First, the ready transportation of
^gs or germs, and their rapid hatching under favorable circum-
stances; and secondly, the different appearances presented by the
same animal at different ages, in consequence of which the youthful
animal may be mistaken, by an ignorant observer, for an entirely
different species. These sources of error are, however, so readily
detected, as a general rule, by scientific investigation, that it is
hardly neceaaary to point out the particular instances in which they
exist. In fact, whenever a rare or comparatively unknown animal
or plant has been at any time supposed to be produced by sponta-
neous generation, it has only been necessary, for the most part, to
investigate thoroughly its habits and functions, to discover its secret
methods of propagation, and to show that they correspond, in all
essential particulars, with the ordinary laws of reproduction. The
limits, therefore, within which the doctrine of spontaneous genera-
tion can be applied, have been narrowed in precisely the same
degree that the study of natural history and comparative physiology
has advanced. At present, indeed, there remain but two classes
of phenomena which are ever supposed to lend any support to the
above doctrine; viz., the existence and production, lat, of infuso-
rial animalcules, and 2d, of animal and vegetable parasites. We
shall now proceed to examine these two parts of the subject in
saccession.

INFUSOBIAL Animalcules.— If water, holding in solution or-
ganic substances, be exposed to the contact of the atmosphere at
ordinary temperatures, it is found after a short time to be filled
with swarms of minute living organisms, which are visible only by
the microscope. The forms of these microscopic animalcules are
exceedingly varied; owing either to the great number of species
in existence, or to their rapid alteration during the successive pe-
riods of their growth. Ehrenberg has described more than SOO
8tt

511

NATURE OF BEPRODtrCTrOW.

DlfftrtDi hiDilaor lupvioirA.

different varieties of them. They are generally provided with cilia
attatlie^l to tlie exterior of their bodies, and are, for the most pari,
in constont and rapid motion in the fluid which they inhabit.

Owing to their pre»enoe in
'''B- *^* animal and rcgetablo wftt«ry

iiifustonS) they have receivod
the name of "iDfuBoria," or
"infusorial animalcules."

Now these infusoria are
always produced under the
conditions which we harede*
scribed above. The animal
or vegetable substauue used
for the infusion may be pre-
viously baked or boiled, so
as to destroy all living germi'
whiob it might aocidenully
contain; the water in which
it is infused may bo carefully
distilled, and thus freed from all simitar contamination; and yet the
Infusorial animalcules will make their appearance at the usual time
and in the usual abundance. It is only requisite that the infusion,
be exposed to a moderately elevated temperature, and to the acoenj
oF atmospheric air; conditions which are equally necessary for
maintaining the life of alt animal and vegetable organisms, what-
ever be the source from which they are derived. Under the above
circumstances, therefore, either the animalcules must hare been
produced by spontaneous generation in the watery infusion, or ihcir
germs must have been introduced into it through the medium of
the atmosphere. No such introduction bos ever been directly de-
monstrated, nor have even any eggs or germs belonging to the
infusoria ever been detected.

Xcverthelcaa, there is every probability that the infusoria are
produced from germs, and not by spontaneous generation. Sinca
the infusoria themselves are microscopic in size, it is not surprising'
that their eggs, which must be smaller still, should have escaped
observation. We know, too, that in many instances the minute
germs of animals or plants may be wafted about in a dry statu by
the atmosphere, until, by acoideulally coining in contact with warmth
and moisture, they become developed and bring forth living oi^n-
isms. The eggs of the infusoria, accordingly, may be easily raised

INFUSOBIAL AMUALCDLES. 516

nod held saapended in tbe atinogpbere, under tbe form of minute
dust-like particles, ready to germinate and become developed when-
ever th«Ly are caught by the surface of a stagnant pool, or of any
artificially prepared infusion. In point of fact, the atmosphere
does really contain an abundance of such dust-like particles, even
when it appears to be most transparent and free from impurities.
This may be readily demonstrated by admitting a single beam of
sansbine into a darkened apartment, when the shining particles sus-
pended in the atmosphere become immediately visible in the track
of the sunbeam. Again, if a perfectly clean and polished mirror
>be placed with its face upward in a securely closed room, and left
undistnrbed for several days, its surface at the end of that time will
be found to be dimmed by the settling upon it of minute dust,
deposited from the atmosphere. There is no reason, therefore, for
disbelieving that the air may always contain a sufficient number of
organic germs for the production of infusorial animalcules.

There is some difficulty, however, in obtaining direct proof that it
M through the medium of the atmosphere that organic germs pene-
trate into tbe watery infusions. It is true that if such an infusion
be prepared from baked meat or vegetables and distilled water, and
aflerward hermetically sealed, no infusoria are developed in it; but
this only shows, as we have already intimated, that the free access
of sir is necessary to the development of all organic life, just aa it is
to the support of animals and plants under ordinary conditions of
growth and reproduction. Such a result, therefore, proves nothing
with regard to the external origin of the infusoria. In order to be
conclusive, such an experiment should be so contrived that tbe
watery infosiou, previously freed from all foreign contamination,
should be supplied with a free access of atmospheric air, while the
introduction of living germs by this channel should at the same time
be rendered impossible. An experiment of this kind has in reality
been contrived and successfully carried out by Schultze, of Berlin.'

This observer prepared an infusion containing organic substances
in solution, and inclosed it in a glass Sask (B'ig. 169, a) of such a
size, that the infusion filled about one-half the entire capacity of the
vessel. The mouth of tbe flask was fitted with an air-tight stopper
provided with two holes, through which were passed narrow glass
tubes bent at right angles. To each of these tubes was attached a
potass-apparatus (6, c), similar to those used for condensing carbonic

■ Edinburgh New Philosophical Joaraftl, Oct., 1837.

OT-C'-'-iy.

tfT— C.^>T-^£t-t^t^-

ol6

JfATURB OF BKPRODtrCTION.

Fig. 169.

x-^

-v.

Schallir'a rxpoHtDrol on SrnXTi>
MioDt QfXEKikriox.— <i. PIfttii con-
Ululng ■mntrtf ludinlnD. &. Polaua ap-
phmtn* (onuiniBE •nlpbarle a<)d, t.

aoH in orgnnic analyses. One of tbese (6) was Glled with concon
trateil sulpliuric nciU, the other (c) with a solutiuu of caustio potnssa.

The Hank with the organic mrusion
having been subjected to a boiling
temperature, io order lo (lestroj aoy
living germa which it might con<
tain, the stopper was inserted, and
the whole apparatus exposed to the
light, at the ordinary Bummer tempera-
lure. TbeoonncctionaoPthc apparatus
boijig [wrfectly light, no air could pene-
trate into the flask, except hy passing
through either the sulphuric auid ur
the potitssa ; either of which would
retain and destroy any organic germs
which might besuspendedin it, Erery
day a fresh supply of air was introduced
into tlie flask by drawing it through
the tubes h, c; and in this way the atmospheric air above the info*
sion was oonstantly renewed, while at the same time the intnxluction
of living germs from without was effectually prevented.

SchuItzB kept this apparatus under his observation, as above, from
the last of May till the first of August : frenuetiUy examining the
edges or the fluid wiih a leua, through the sides of the glass jar,
but without ever detecting in it any traces of living organistna At
the end of that periwl the flask was opened, and the fluid which it
contained subjected to direct e.xaminatioD, equally without resulu
It w:i8 then exposed, in the same vessel and in the same situation
as before, to the free access of the atmosphere, and at the cod of
two or three days it was found to be swarming with infusoria.

It is plain, therefore, that the infusoria canuot be regarded as
produced by spontaneous generation, but must be oonsidcrod as
originating in the uHunl manner from germs; since they do not
make their ap[)€arance in the watery infusion, when the accidental
introduction of germs from without has been efioctually provcntod.

Animal and Veortablr PAnASiTKS. — This very remarkable
group of organized bodies is distinguished by the fact that they
live cither upon the surface or in the interior of other animal or
vegetable organisms. Thua, the mistletoe lixes itself on the branches
of aged trees ; the Oidtum allncaiia vegetates upon the muoons sur-

AKIUAL AND VEGETABLE PARASITES. 617

fftces of the mouth and pharynx; the Bolrytis Bamana attacks the
bod; of the silkworm, and plants itself in its tissues; while many
species of iremtUoid worms live attached to the gills of fish and of
water- lizards.

These parasites are usually nourished by the flaids of the animal
whose body they inhabit. Each particular species of parasite is
found to inhabit the body of a particular species of animal, and is
not found elsewhere. They are met with, moreover, as a general
role, only in particular organs, or even in particular parts of a
ungle organ. Thus the Tricocephalus dispar is found only in the
csBoum; the Strongylus gi gas in the kidney; the Distoma hepatt-
cum in the biliary passages. The Distoma variegatum is found
only in the lungs of the green frog, the Distoma cylindraceum in
those of the brown. The Taenia solium is found in the intestine of
the human subject in certain parts of Burope, while the Taenia lata
occurs exclusively in others. It appears, therefore, as though some
local combination of conditions were necessary to the production
of these parasites; and they have been supposed, accordingly, to
originate by spontaneoas generation in the localities where they
are exclusively known to exist,

A little consideration will show, however, that the above condi-
Uons are not, properly speaking, necessary or sufficient for the
production^ but only for the devtlopment of these parasites. AH the
parasites mentioned above reproduce their species by generation.
They have male and female organs, and produce fertile eggs, oflen
in great abundance. The eggs contained in a single female Ascaris
are to be counted by thousands; and in a tapeworm, it is said, even
by millions. Now these eggs, in order that they may be hatched
and produce new individuals, require certain special conditions
which are favorable for their development; in the same manner
as the seeds of plants require, for their germination and growth, a
certain kind of soil and a certain supply of warmth and moisture.
It is accordingly no more surprising that the Ascaris vermicularis
should inhabit the rectnm, and the Ascaris lumbricoides the ileum,
than that the Lobelia inQata should grow only in dry pastures, and
the Lobelia cardinalis by the side of running brooks. The lichens
flourish on the exposed surfaces of rocks and stone walls; while
the fnng^ vegetate in darkness and moisture, on the decaying trunks
of dead trees. Yet no one imagines these vegetables to be spon-
taneously generated from the soil which they inhabit. The truth
is simply this, that if the animal or vegetable germ be deposited iu

518

NATCHS OF" EEPRODUCTION.

a locnlity which affortls tho rcquisttocoDclilionAfor its development
it becomea dicveloped ; otherwise noL Each female Ascarls pro-
duces, AS we have stated above, many tbousaods of ova. Nuw,
though the chaDces are very great against any particular one of
these ova being accidentally transported into the intestinal canal of
nuolber individual, it is easy to see that there arc many causes in
operation by which aome of them might be so transported. By far
the greater number undoubtedly perish, from not meeting with the
conditions necessary for their development. One in a thousand, or
perhaps one in a million, in accidentally introduced into the body
of another individual, and consequently becomes developed there
into a perfect Ascaris.

Thecircumfltanoc, therefore, that particular parasites areconflDed
to particular localities, presents do greater dil1i<;ulty as to their
mode of reproduction, than tho same fact regarding other animal
and vegetable organisms.

Neither is there any diflaeulty in uccounting for the introduction
of parasitic germs into the interior of the body. The air and the
food offer a ready means of entrance into the respiratory and
digestive passages; and, a parasite once introduced into the inics-
tinc, there is no difficulty in accounting for its presence ia any of
the duets leading from or opening into the alimentary canal. Some
pnrasitea are known to insinuate themaelvea directly underneath
the surface of the skin; as the Pulex penetrans or "cbiggo" of
South America, aud the Ixodes Americaous or "tick." Others,
like the (Kstraa bovis, penetrate the integument for the purpose of
depositing their eggs in the subcutaneous areolar tissue. Some
may even gain an entrance into the bloodvcsselit, and circulate in
this way all over the b<xily. Thus the Filaria rubella is found alive
in the bloodvessels of the frog, the Distoma biematobium in those
of the human subject, and a species of Spiroptera in those of the
dog. It is easy to see, therefore, how, by such means, parasitic
germs may be conveyed to any part of the body; and may even be
deposited, by accidental arrest of the circulation, in the substance
of the solid organs.

The most serious difficulty, however, in the way of accounting
for the production of parasitic orgitnisms, was that presented by the
existence of a class known as the encysted or ee^kn entozoa. These
parasites for the most part occupy the interior oF the solid organs
and tiasues, into which they could not have gained access by the
mucous cannlii. Thus the Ccunurus cvrebralis id found imbedded

AXIMAL AND VBOETABLB PAHASITES.

61P

TaicHiiTA »rriALi*; from r*riu* rfinvrt* Mft*.

in the sabsUnoe of the braiti, the Trichina spiralis between the
fibres of the voluntary muscles, and the Cysticcrcus celluloste in the
areolar tissoc of various parts of the body. They are also distin-
guished from all other paraaitea by two peculiar characters. First,
they are inclosed io a distinct cyst, with which they have no organic
connection and from which they may be readily separated; and se-
ciondly, they have no genera-
live organs, nor is there any P'?- 1*^-
apparent diflerence between
the aexea. Tlie Trichina api-
jmlts, for example (Fig. 170),
ia inclosed in aa ovoid or
spiodleshaped cyst, swollen
in the middle and tapering at
«aeh extremity, with a round-
ed cavity in its central por-
tion, in which the worm lien

coiled up in a spiral form. The worm iucif has neither testicles
nor ovariea, nor does it present any trace of a sexual organization.

Now we have seen that it is easy to account for the conveyance
of these or any other parasites into the interior of vascular organs
and ti.«sucs ; the eggs from which they arc produced being trans-
ported by the bloodvessels to any part of the body, and there
retained by a local arrest of the capillary circulatiotu In the case
of the encysted cntozoa, hnwcver, wo have a much greater dilTi-
culty; since these parasites are entirely without sexual organs or
generative apparatus of any sort, nor have they ever been dis-
covered in the act of producing eggs, or of developing in any
manner a progeny similar to theinselvea. It appears, accordingly,
iVifficult to understand how animals, which are without a sexunl
apfiarutus, should have been produced by acxual generation. As
it is certain that they can have no progeny, it would aecra equally
evident that they must have been produced without a parentage.

This difficulty, however, serious as it at flrst appears, is susceptible
of a very simple explanation. The case is in many reflpectflanalognufl
to that of the maggots, hatched from the eggs of flies in putrefying
meat. These maggots are also without sexual organs; for they
are still inifierfuctly developed, and in a Icind of embryonic condi-
tion. It is only after their metamorphosis into perfect insects, that
generative organs are developed and a distinction between the
■exes manifests itself. This is, indeetl, mure or less the case with

620

rATCBB or

STiOy.

all animala nnd with all vegetaWas. The blossom, which is the
sexuiil apparatus uf the plarit, does not appear, as a geoernl rule,
until the growth of the vegetable has cotititiued fur q certain time,
and it has acquired a certain age and strength. Kven in ihe human
fluhjcct the acxual organs, though present at birth, arc still very
imperfectly developed as to size, and altogether inactive in func-
lion. It is Duty later that these organs acquire their full growth,
and the sexual characters become complete. In very miiny uf the
lower animals the sexual organs are entirely absent at birth, and
appear only at a later period of development.

Now the ency&teil or sexless entozon are simply the undeveloped
young of other parasites which propagjite by sexual generation;
the membrane in which they are inclosed
?'«■ !"*■ being either an embryonic envelope, or else

an adventitious cyst formed round the para-
Hitic embryo. Tliese embryos have uome, in
the natural course of their migrations, into
a situation whirh is not suitable for their com-
plete developnieot. Their development is
accordingly arrested before it arrives at matu-
rity ; and the parasite never reachca the adult
condition, until removed from the situation in
which it has been placed, and transported to a
more favorable locality.

The above explanation has been demon-
strated to be the true one, more particularly
with regard to the Tienia, or tapeworm, and
several varieties of Cysticercus. The Ttntia
(Fig. 171) is a pnrafiiioof which diftereni species
are found in the intestine of the human subject,
the dog, cat, fox, and other of the lower aiiiinaU.
Its upper extremity, termed the "bead," con-
sists of a nearly globular mass, presenting upon
il8 lateral surfaces a set of four muscular disks,
or "auckors," and terminating anteriorly in a
conical projection which is pn>vided with a
crown of curved prooeasea or hooks, by which
1^,,^. the parasite attaches itself to the intestinal

mucous membrane. To this "heatl" succeeds
fl slender ribbon-shxpcd neck, which is at first smooth, but which
Boon becomes imnsversely wrinkled, and afterward divided into

ANIMAT. AND TBGGTABT.E PAKAAITES.

621

distinct rectangTilur pieces or "8rticulaliun»." These articulations
multiply by & procetui of successive growth or budding, from the
wrinkled portion of the neck ; and are constantly remove<l further
ftnd farther from their point of origin by new ones formed behind
them. Aa tht;y gradually descend, by llie process of growth,
farther down the body of the tapeworm, they become larger nnd
begin to exhibit a sexual apparatus, developed in their interior.
In each fully formed rtrticnlntion there are contained both male
and female organs of generation; and the mature egg«, which are
produced in great numbers, are thrown off together with the articu-
lation itflclf from the lower extremity of the tapeworm. Since the
nrtienlfllions are successively produced, us wc huve mcntionwl above,
by budding from the neck and the buck part of the head, the para-
site cannot be effectually dislodged by taking away any portion of
the body, however hirgo; since it is subHequently reproduced from
the head, and continues its growth as before. But if the head itself
bo removed from the intestine, no further reproduction of the articu-
lations can take place.

The Cijstitxrcfts is an encysted parasite, different varieties of which
are found in the liver, the peritoneum, and the meshes of the areolar
tissue in various parts of the body. It consists (Kig. 172), first, of
a globular sac, or cyst (a), which is not adherent to the tissues of
the organ in which the parasite is found, but may be easily sepa-
rated from them. In its interior is found another sac ih\ lying

Fig. 172.

Pip. 173.

CuricllOt*.— m KKl»ri>«l rjft h Ib>
tprual Me. «DalaliiieiK Bald. «. Xarruw «»»&!.
funiiM bjr Intnluilou nf wiJli <ir Mr, at Iba
bulltilH otwlilcb 1* IIibIiiMU r>rilic l«lit*.

Cll«TIOKkct(, DDfoliI'

Ii).nw in the cavity of the former, nnd filleil wlih a serous fluid.
Tliis second sac present^ ot one point upon its surface, a puckered
depression, leading into a long, narrow canal (c). This canal, which
is formed by an involution of the wuUs of the second sac, preitcDta

522

rATCBS O? BSPRODtTCTIOl

al its bottom a small globular mass, like the bead of tbe Tsenia,
provideil with suckers and hocks, and sup)><)rted upon a short
slender neck. If the outer investing sac be removed, the narrow
canal just described may be everted by carerul maDipuIation, and
the parftsite will then appear as in Fig. 173, with the head and neclc
resurnblirig those o1' a Taenia, but terminating behind Id a dropsical
saC'like swelling, instead of the chain of articulations which are
characteristic of the fully formed tapeworm.

Now it has been shown, by the experiments of KUchenmeiater.
Siebold, and others, that tbe Cystioercus is only the imperfectly
developed embryo, or young, of the Trcnia. When the mature
artiouldtion of tho tapeworm is thrown off, as already mentioned,
from its poaterior extremity, the eggs whicli it incloses have already
passed through a certain period of development, so that each one
contains an imperfectly formed embryo. The articulation, contain-
ing the eggs and embryos, is then taken, with the food, into the
stomach of another animal; the substance of the artioulation, to- fl
gether with the external covering of the eggs, is destroyed by di-
gestion, and the embryos are thus set free. They then penetrate,
through the wulla of the stomach, into the neighboring organs or H
[he areolar tissue, and, becoming encysted in these situations, are
there developed into cystioerci, as represented in Fig. 172. After-
ward, the tissnes in which they are contained being devonred by
another animal, the cysttcereus passes into the intestine, fixes itself
to the mucous membrane, and, by a process of budding, produce*
the long tape-liko series of artieulationa, by whieh it is finally con-
verted into the full-grown Tienin.

Prof. Siebold found the head of the Cystioercus fasciolaris, met
with io the liver of rats and mice, presenting so close a resem-
blance to the Tmnia crassicollis, inhabiting the intestine of the cat, fl
that ho was led to believe the two parasitea to be identical. This
identity was, in fact, proved by the experiments of Kiichenmeister;
and Siebold afterward demonstrated' the same relation to exist H
between the Cysticercus pisiformis, found io tbe peritoneum of rah- ~
bits, and the Tomia scrrato, from the intestine of the dog. Tbis
experimenter succeeded in administering lo dogs a quantity of the
oyslicerci, fresh from the body of the rabbit, mixed with milk; and
OQ killing the dogs, at various periods af^r the meal, from three ^

■ til lliilT:i1o M«-lical Joiirndl, FvU. ISSl; aho In Sivboltl on Tap* and Cj«Ue
Woniu), Sjrduubam IraaKUllou: Londou, 1897, p, M).

AI7IVA.L AND TBOETABLB PABASITES. 523

hoars to eight weeks, he foand the cysticerci in various stages of
developmeot in the intestine, and finally converted into the full
grown T»nia,'with complete articulations and mature eggs.

Dr. Kachenmeister' has also performed the same experiment, with
success, on the human subject. A namber of cvsticerci were ad-
ministered to a criminal, at different periods before his ezocution,
varying from 12 to 72 hours; and upon post-mortem examination
of the body, no less than ten young taenia were found in the
intestine, four of which could be distinctly recognized as specimens
of Taenia solium.

Finally, both Leuckart and KBchenmeister* have shown, on the
other hand, that the eggs of Tseoia solium, introduced into the body
of the pig, will give rise to the development of Cystioercua cellulosse ;
thus demonstrating that the two kinds of parasites are identical in
their nature, and differ only in Uie manner and degree of their
development.

There remains, accordingly, no good reason for believing that
even the encysted parasites are produced by spontaneous genera-
tion. "Whatever obscurity may hang round the origin or reproduc-
tion of any class or species of animals, the direct investigations of
the physiologist always tend to show that they do not, in reality,
form any exception to the general law in this respect ; and the only
opinion which is admissible, from the facts at present within our
knowledge, is that organized bemga^ animal and vegetable, wherever they
may be found, are always the progeny of previously existing parents.

' On Animal and YttgtttaMo Par&siten, S^dBDUain trnnsUtioa: London, 1857,
p. 119.

* Op. olt., p. 120.

^ ?Y: .

} /

' . 'S-c'-'

524

SrSU'AL OBySBATlO!^.

CHAPTER ri.

OS SEXUAL GENERATtOX. AND THE MODE OF ITSi
ACCOMPLISHMENT.

Fig. 174.

Thb function of gonerntion is perfcirined by means of two seU of
origans, each of which gives origin to a peeulinr prodaot, capoble
of uniting with the other so m to produce anew individual. Tbendj

two seta of organs, belonging to the
two different sexes, are called the male
and female organs of generation. The
female organs produce a globular body
called the jerm, or egrf, which is capable
of being developed into the body offl
the young animal or plant; the male
organa produce a substance which ia y
necessary to fecundate the germ, and I
enable it to go through with its natural
growth and development ■

Such are the only essential and uoi* f
versal characters of the organs of gene-
ration. Theae organa, however, exhibit
vnrious additions and modifications ia
different claasea of organized beings,
while they show throughout the same
fundamental and essential characters.

In the flowering plants, for example,
the blossom, which ia the geaerativOj
apparatus (Fig. 174), consists Grat of
female organ containing the germ (a), situated usually opoo th&]
highest part of the leaf bearing stalk. This is surmounted by
nearly straight column, termed the pistil (&), dihited at iu summit'
into a globular expansion, and occupying the centre of the flower.
Around it are arranged several slender filaments, or stamena, bear-
ing upon their extremities the male organs, or anthers (c, c\ Tbo;

BtfiKOM np C««*(ii,'rvi.ca
Pr ■ fi ■ HI."* (Uiituliig dlurir.)— <».
0*riii b. I*i>ill. «- p. Stuii'Ds «lth
■ulhvra. d. CvruIU *. Calrx.

8&XUAL QBNERATIOK.

525

Fig. 175.

whole is SQrrounded by a circle or crown of delicate and brilliantly
colored leaves, termed the corolla (d), which is frequently provided
with a smaller sheath of green leaves outside, called the calyx (e).
The anthers, when arrived at maturity, discbarge a fine organic
dast, called the poUen, the granules of which are caught upon the
extremity of the pistil, and then penetrate downward through its
tissues, until they reach its lower extremity and come in contact
with the germ. The germ thus fecundated, the process of genera-
tion is accomplished. The pistil, anthers, and corolla wither and
fall off, while the germ increases rapidly in size, and changes in
form and texture, until it ripens into the mature fruit or seed. It
is then ready to be separated from the parent stem; and, if placed
in the proper soil, will germinate and at last produce a new plant
umilar to the old.

In the above instance, the male and female organs are both
situated upon the same £ower; as in the lily, the violet, the con-
volvulus, &c. In other cases, there are separate male and female
flowers upon the same plant, of which the male flowers produce
only the pollen, the £emale, the
^rm and fruit In others still,
the male and female flowers are
situated upon different plants,
which otherwise resemble each
other, as in the willow, poplar,
and hemp.

In animals, the female organs
of generation are called ovarifs,
since it is in them that the egg,
or "ovum," is produced. The
mole organs are the tealicles,
which give origin to the fecun-
dating product, or " seminal
fluid," by which the egg is fer-
tilized. We have already men-
tioned above that in the articula-
tions of the tapeworm the ovaries
and testicles are developed to-
gether. (Fig. 175.) The ovary

(a, a, a) is a series of branching follicles terminating in njunded
extremities, and communicating with each other by a central canal.
The testicle (h) is a narrow, convoluted tube, very much folded

SixuLK ABTirpLATrnir nr Tjbsia
CRAdBtCOLr.il, rrimi alUAll luluallu« lit c«i. —
a, a. n Oyrj llll«d with eggi. b. Tnticle. c.
GcDllkl on tire.

526

BRXCAL OENERATIOy.

upon ilself, wliich opens by an externa! orifice (c) upon ihe Utertl
bonier of tbe articulation, about inidwaj between itd two ex-
tremities. The spermfttic fluid produced in the testicle is intro-
duced into the femtile generative passage, which opetiB at the same
spot, and, penetrating deeply into the interior, comes tn contact
with the eggs, which are thereby fecundated and rendered fertile.
The fertile eggs are afU'rivard set free by the rupture or decay of
the articulation, and a vaat number of young produced by their
development.

In snails, also, and in some other of the lower animals, the ovaries
and testicles are both present in the same individual; so that these
animals are sometimes said to be "hermaphrodite," or of double
Bex. In reality, however, it appears lliat the male and female
organs do not come to maturity at the same time; but the ovaries
are first developed and perform their function, after which the tet*
tides come into activity in their turn. The sarao individual, there*
fore, is not both tnule and female at any one time; but is lir<>t
female and aflcrward male, exercising the two generative functioni
flt different ages.

In all the higher animals, however, the two sets of generative
tirgana are located in separate individuals; and the spocies is
euDHequently divided into two sexes, male and female. All thai
is absolutely requisite to oonsiituw the two sexes is the existence
of testicles iu the one, and of ovaries in the other. Beside these,
however, there are, in most instances, oertaia secondary or acces-
sory organs of generation, which assist more or less iu the accom-
plishment of the process, and which occasion a greater difference
in the anatomy of the two sexes. Such arc the uterus and mam-
mary glands of the female, the vesiculfe seminoles and prostate
of the male. The female naturally having the immediate care of
the young adcr birth, and the male being oocupied in providing
food and protection for both, there are also corresponding differ-
ences in the general structure of the body, which affect the whole
external appearance of the two sexes, and which even show them-
selvea in their mental and moral, as well as in their physical
characteristics. In some cases this difference is so excessive that
the male and female would never be recognized as belonging to tht
same species, unless they were seen in company with each other.
Not to mention some extreme instances of this among insects and
other iovertebraie animals, it will be sufficient to refer to the well
known examples of the cook and the hen, the lion and lioness, the

SSXITAL OSNKBATIOX. 527

back and the doe. Id the human species, also, the distinction
between the sexes shows itseir in the mental constitution, the dis-
position, habits, and pursuits, as well as in the general conforma-
tioD of the body, and the pecaliaritiea of external appearance.

We shall now study more fully the character of the male and
female organs of generation, together with their products, and ttie
manner in which these are discharged from the body, and brought
into relation with each other.

538

KOR ASD FRMALE ORGANS OP QB5ni«AT!OS.

CHAPTER Til.

ON THE EOG, AND TlIK FKMALE ORGANS OP
UKNKRATIOX.

Tnn egg is a globular body whicb varies considernblj? in size in
different classes of animals, according lo die peculiar conditions
under which its development is to take place. In the frog it men-
eiures ,'s uf an inch in diameter, in the lamprey nV '^ quadrupeds
and in ths human species , jg,. It consisU, first, of a membranous
external snc or envelope, the viteUine memhrane; and secondly, of a
spherical mass inclosed in its interior, called the vitttUug.

The I'ilelUm mtrmbrant iii birds and reptiles is very thin, measur-
ing oflen nut more ihnn ^sIiod ^^^^ itich in thickness, and is at the

same time of a somewhat fibrous texture.
^'P-'"''- In man and the higher animals, on the

contrary, it is perfectly smooth, structure-
leas and transparent, and is about 11*011 of
an inch in thickness, Nolwithstauding
its delicate and transparent appearance, it
has a considerable degree of resistance
and elasticity. The egg of the human
Riibject, for example, may be perceptibly
flattened out under the microscope by
pressing with the point of a needle upon
the slip of glass whicb covers it; but it
still remains unbroken, and when the
pressure ia removed, readily resumes its globular form. When the
egg is .somcwiiat flattened under the microscope in this way, by
preaaure of the glass slip, the apparent thickness of the vitelline
membrane is increased, and it then appeiirs (Fig. 176) as a rather
wide, colorless, and pellucid border or 7.one, surrounding the grann-
I »r and opaque vitelEus. Owing to this appearance, it has some-
timos received the name of the "zona pellucida.'' The name of
vitelline membrane, however, is the one more generally adopted
and is nlco the more appropriate of the two.

UoiS llitiK, iiiaiDiRnl V<
dtanftiTn. n VIlMIlnnnifnibriiin.
ft.Vli«llci». r. Upnnla>l|VDT«ltla.
d. GaraRlaMK* apot.

EOO AND FBXALE 0RGAK8 OF OKNEBATION. 529

The viUllua (b) is a globular, semi-solid mass, contaJQed within
the ritellioe membraDe. It consists of a colorless albaminoid sub-
staoce, with an abundance of minute molecules and oleaginous
granules scattered through it. These minute oleaginous masses
give to the vitellos a partially opaque and granular aspect under
the microscope. Imbedded in the vitellus, usually near its surface
and almost immediately beneath the vitelline membrane, there is a
dear, colorless, transparent vesicle (c) of a rounded form, known
as the germmative ixaicU. In the egg of the human subject and of
the quadrupeds, this vesicle measures g^g to ^^ of an inch in
diameter. It presents upon its surface a
dark spot, like a nucleus (d), which is known Fig. 177.

bj the name of the germinaiive apoi. The
germinative vesicle, with its nucleus-like
spot, is oflen partially concealed by the
granules of the vitellus by which it is sur-
rounded, but it may always be discovered
by careful examination.

If the egg be ruptured by excessive pres- hcmai orr>. mpmndbr
sure under the microscope, the vitellus is p^"": "">''"« 'i" """»-

^ ' , pkrilallf expclln), lbs germlna-

seen to have a gelatinous consistency. It lUe tmIci* at a, and tha imooih
is gradually expelled from the vitelline J;^";"" *^ "* ''"'"" """"
cavity, but still retains the granules and oil

globoles entangled in its substance. (Fig. 177.) The edges of the
fractured vitelline membrane, under these circumstances, present a
smooth and nearly straight outline, without any appearance of
laceration or of a fibrous structure. The membrane is, to all ap-
pearance, perfectly homogeneous.

The most essential constituent of the egg is the vitellus. It is
from the vitellus that the body of the embryo will aflerward be
formed, and the organs of the new individual developed. The
vitelline membrane is merely a protective inclosure, intended to
protect the vitellus from injury, and enable it to retain its figure
during the early periods of development

The egg, as above described, consists therefore of a simple
vitellus of minute size, and a vitelline membrane inclosing it. It
is such an egg which is found in the human subject, the quadru-
peds, most aquatic reptiles, very many fish, and some invertebrate
animals. In nearly all those species, in fact, where the fecundated
eggs are deposited and hatched in the water, as well as those in
which they are retained in the body of the female until the develop-
84

630 EGO AlfD FBMALK ORGANS Of OENERATIOIT.

meet of the young is completed, such an egg as above described \a
sufficieot for the formatioQ of the embryo; since during its develop-
rocDt it can absorb rrccly^ cither from the water in which it floats,
or from tho mucous membrane of the female generatire organs, the
requisite supply of ntnritiou.s fluids. But in birds and in the
terrestrial reptiles, such as lizards, tortoises, JStc^ where the eggs
are expelled from the body of the female at an early period, and
incubated on land, there is no external source of nutrition, to pro-
vide for the support of the young animol during its development.
Iq these instances accordingly the vitellusi or "yolk," as it is called,
is of very large size; and the bulk of the egg is still further io>
creased by the addition, within the female generative passages, of
layers of albumen and various external fibrous and calcareous
envelopes. The essential constituents of the egg, however, sUll
remain the same in character, and the process of embryonic deve* ^
lopment follows the same general laws as in other oaaea. ^^

The eggs arc produced in tho interior of certain organs, sitaated
in the abdominal cavity, called ihe ovaries. These organs consist
of a number of globular sacs, or follicles, known as the "Graafian
rolliclcs,^' each one of which contains a single egg. Tho follicles
are connected with each other by a quantity of vascular areolar
tissue, which binds them together into a well-dcilned and oonoistent
mass, covered upon il* exterior by a layer of peritoneam. The i
egg has sometimes been spoken of as a "product," or even as >fl
"aecrclion" of the ovary. Nothing can be more inappropriate, "
however, than to compare the egg with a f»ccrction, or to regard the
ovary as in any respect resembling a glandular organ. The egg is
simply an organized body, growing in the ovary like a tooth in its
follicle, and forming a constituent part of the body of the female.
It is destined to be finally 8epsrate<l from its attachments ami
thrown oft'; but until that time, it is, properly speaking, a part of
the ovarian texture, and is nourished like any other portion of the ^4
female organism, H

The ovaries, accordingly, since they are directly concerned in
the production of the eggs, are to be regarded as the essential
parts of the female generative apparatus. Beside them, however,
there are usually present certain other organs, which piny a secon-
dary or accessory part in the process of generation. The most
important of these accessory organs are two symmetrical tubes; or
ovidttets, which are destined to receive the eggs at their internal
extremity and convey ihem to the external generative orifice. Tho

■ Ga AND FZMALK ORGAN'S 07 GBNKBATION.

681

Fig. 178.

macons membrane lining the oviducts is also intended to supply
certain secretions during the passage of the egg, which are requi-
site either to complete its structure, or to provide for the nutrition
of the embryo.

Id the frog, for example, the oviduct commences at the upper
part of the abdomen, by a rather wide orifice, which communicates
directly with the peritoneal cavity. It
aoon after contracts to a narrow tube,
and pursues a zigzag course down the
side of the abdomen (Fig. 178), folded
apoD itself in <»nvolutious, like the
small intestine, until it opens, near its
fellow of the opposite side, into the
"cloaca," or lower part of the intestinal
canal. The oviducts present the same
general characters with those described
above, in nearly all species of reptiles
and birds ; though there are some modi-
6cations, in particular instances, which
do not require any special notice.

The ovaries, as well as the eggs which
they contain, undergo at particular sea-
sons a periodical development or increase
in growth. If we examine the female
frog in the latter part of summer or the
fall, we shall find the ovaries presenting

the appearance of small clusters of minute and nearly colorless
eggs, the smaller of which are perfectly transparent and not over
T7V of an inch in diameter. But in the early spring, when the
season of reproduction approaches, the ovaries will be found in-
creased to four or five times their former size, and forming large
lobalated masses, crowded with dark-colored opaque eggs, measur-
ing t'j of an inch in diameter. At the approach of the generative
season, in all the lower animals, a certain number of the eggs, which
were previously in an imperfect and inactive condition, begin to
increase in size and become somewhat altered in structure. The
vitellus more especially, which was before colorless and transparent,
becomes granular in texture as well as increased in volume ; and
assumes at the same time, in many species of animals, a black,
browD, yellow, or orange color. In the human subject, however,

Pl>ALI OlHBBATITI OM-

dahi or Pioo. — a, a. Orarie*.
b, h. OtUbcU. c, e. Tbeir lolerDkl
orlflcM. d. Goan, ibowlnc asiar-
Dal orlflcva nt ovldneta.

£82

EOO AKO FEMALE 0R0AN8 OF GEyKBATIOX.

the cliangc consists only in an incr«&5e of size and granalatioa,
without any remarkable alteration of color.

The eggs, as they ripen in this way, becoming enlarged uii
changed in texture, gradually distend the Oraallan folliclea at
project from the aurfaoe of the ovary. At last, when fully ripe,]
they are diacharged by a mpturc of the walls of the follicles, and,
passing into the oviducts, are conveyed by them to the exteroalJ
generative orifice, and there e:cpetled. lu this way, as suoc«t»tv«J
seasons corae round, successive crops of eggs enlaige, ripen, leavsl
the ovaries, and are dlischarged. Those which arc to be expelMf
at the next generative epoch may always be recognized by thcirl
greater degree of development; and in this way, in many animala,}
the eggs of no less than three different crops may be recognised itt]
the ovary at once, viz., Ist, those which are perfectly mature and'
ready to be discharged ; 2d, those which are to ripen in the follow-
ing season ; and 3d, those which are as yet altogether inactive and
undeveloped. In most fish and reptiles, as well as in birds, this
regular process of maturation and discharge of eggs takes place
but once a year. In different species of quadrupeda it may take
place annually, semi-atmually, bi-monthly, or even monthly; but
in every instance it recurs at regular intervals, and exhibits aocord-
ing1y, in a marked degree, the periodic character which we have
seen to belong to moat of the other vital phenomena.

Action of the Oviducts and Female Oenerative Pas$aga.-~-ln frogs
and lizards, the ripening and discharge of the eggs take place, as
above mentioned, in the early spring. At the time of leaving the
ovary, ihe eggs consist simply of the dark-colored and granular
Tilellus, inclosed in the vitelline membrane. They are then received
by the inner extremity of the oviducts, and carried downward by
tbe peristaltic movement of these canaU, aided by the more power-

Fbl contraction of the abdomin^ ronB* |
clcs. During the pasitage of the eggBi
moreover, the mucous merabrftne of
the oviduct secretes a colorless, viscid,
albuminoid substance, which is depo-
sited in successive layers roond each
egg, formiug a thick and tenacious
coutingorenvelope. (Fig.lTfi.) When
the eggs are finally diacharged, this
albuminoid matter absorba the valer
in which the spawn is deposited, and swells up into a transporeDt

Pig. 179.

MATr** rnovi' laoi,— a. Whll*
IIUI Id lb* ciary. i, Aflat |ia«ilD(
IkttfUfh Ih* OTlilnct

XaO AND FBKALE OBGAKS OF 6EKKBATI0N'. 6SS

gelatinous vaaaa, in whioh the eggs are separately imbedded. This
sabstaooe sappliea, by its subsequent liqueFaction and absorptioD,
a certain amount of nutritious material, daring the development
and earlgr growth of the embryo.

In the terrestrial reptiles and in birds, the oviducts perform a
still more important secretory function. In the common fowl, the
ovary consists, as in the frog, of a large number of follicles, loosely
connected by areolar tissue, in which the eggs can be seen in different
stages of development (Fig. 180, a.) As the egg which is approach*
iug maturity enlarges, it distends the cavity of its follicle and pro-
jects &rther from the general surface of the ovary; so that it hangs
at last into the peritoneal cavity, retained only by the attenuated
wall of the follicle, and a slender pedicle through which run the
bloodvessels by which its oircalation is supplied, A rupture of the
foUide then occurs, at its most prominent part, and the egg is dis-
charged from the lacerated opening.

Av the time of its leaving the ovary, the egg of the fowl consists
of a large, globular, orange-colored vitellus, or "yolk," inclosed in
a thin and transparent vitelline membrane. Immediately under-
neath the vitelline membrane, at one point upon the surface of the
vitellus, is a round white sp>ot, consisting of a layer of minute
granules, termed the "cicatricula.*^ It is in the central part of the
cicatricula that the germinative vesicle is found imbedded, at an
early stage of the development of the egg. At die time of its
discharge from the ovary, the germinative vesicle has usually dis-
appeared; but the cicatricula is still a very striking and important
part of the vitellns, as it is from this spot that the body of the chick
b^ns afterward to be developed.

At Uie same time that the egg protrudes from the surface of the
ovary, it projects into the inner orifice of the oviduct; so that, when
discharged from its follicle, it is immediately embraced by the upper
or fringed extremity of this tube, and commences Its passage down-
ward. In the fowl, the muscular coat of the oviduct is highly deve-
loped, and its peristaltic contractions gently urge the egg from above
downward, precisely as the oesophagus or the intestines transport
the food in a siniilar direction. While passing through the first
two or diree inches of the oviduct (c, d), where the mucous mem-
brane is smooth and transparent, the yolk merely absorbs a certain
quantity of fluid, so as to become more flexible and yielding in con-
sistency. It then passes into a second division of the generative
canal, in which the mucous membrane is thick and glandular in

fi84 EGO AXD FEMALE ORQAXS Or OKNERATION.

texture, and in also thronn into numerous longiludioal Toldi, wbich
project into tbe cavity of the oviduct. This portioa of the oviduct
{d, e) extends over about nine incbes of its entire length. In m
upper part, tbe mucous membrane secretes a viscid material, by
which the yolk is encased, and which soon consolidates into a gela-
tinous, membranous deposit; thus forming a second homogeoeoos
layer, ouLiidc the vitelline membrane.

Now tbe peristaltic movements of this part of the oviduct are
Bocb OS to give a rotatory, as well as a progressive motion to Ihe
0SS> ^"^ ^^'^ ^^^ oxtrcmitie8 of the membranous layer described
above become, accordingly, twisted, in opposite directions, into two
fine cords, which run backward and forward from the opposite poles
of the egg. These cord;^ are termed the "chalazw," and the mem-
brane with which they are oonnectedf tbe "cholaziferous membrane."

Throughout the remainder of the second division of the ovidoct,
the mucous membrane exudeii an abundant, gelatinous, albuminoid
substance, which is deposited in succesaive layers round the yolk,
inclosing at the same time the chalaziferous membrane and the
chalazte. This substance, which forms the so-called albumen, or
"white of egg," is semi-solid in consistency, nearly transparent, and
of a faint amber color. It is deposited in greater abuDdance in front
of tbe advancing egg than behind it, and forms accordingly a
pointed or conical projection in front, while behind, its outline is
ronndcd off, parallel with the spherical suriace of the yolk. In this
way, the egg acquires, when covered with its albumen, an ovoid
form, of which one end is round, the other pointed; the pointed
extremity being always dirccLciI downward, as the ^g desoeodfl
along the oviduct.

In the thiol division of the oviduct (/), which is nSout three and
a half inches in length, the mucous membrane is arranged in longi-
tudinal folds, which are narrower and more closely packed than in
the preceding portion. The material secretwl in this part, and de-
posited upon the egg, condenses into a firm Gbrous covering, com-
posed of three different layers which closely embrace the surface
of the albuoiinous mass, forming a tough, flexible, semi-opaque
envelope for the whole. These layers are known as the external,
middle, and internal Bbrous membranes of the ^g.

Finally the egg passes into the fourth division of tbe oviduct (y),
which is wider than the rest of the canal, but only a little over two
inches in length. Bero the mucous membrane, which is arranged
iu abundant, projecting, leaf-like villosities, exudes a fluid very rich

BOS AUrV PBUALB OROAKS OP OBXSRATIOIC.

5S6

Fig. 180.

i'.j*

in calcareous salts. The most external of the three membranes
jast described ia permeated by this fluid, atid very sood ilic calcare-
ous matter begins tocrysullize in the inLcrstieesof ita fibres. This
deposit of calcareous matter goes on, growing constantly thicker
Rod more condensed, until the entire
external membrane is converted into
a while, opaqao, brittle, calcareous
shell, which incloses the remaining
portions and protects them from ex-
ternal injury. The egg is then dnveo
outward by the contraction of the
muscular cont through a narrow por-
tion of the oviduct (A), and, gradually
dilating the passages by its conical
extremity, is finally discharged from
the external orifioe.

The egg of the fowl, aflor it has
been discharged from the body, con-
sists, accordingly, of various parts;
some of which, as the yolk and the
vitelline membrane, entered into its
original formation, while the remain-
der have been deposited ronnd it dur-
iag its passage through the oviduct.
Oo examining such an egg (Fig. 181),
we tind externally the calcareous
shell (h\ while immediately beneath
it are situated the middle and internal
fibrous shell-membranes (e,/).

Soon a(Ur the expulsion of the egg
there is a partial evaporation of ita
watery ingredients, which are replaced
by air penetrating through the pores
of the shell at its rounded extremity.
The air thas introduced accumulates
between the middle and internal
fibrous membranes at this spot, sepa-

FtBAbx OaaiBiTiTR Oaaum or 7nWL — <|. nr^tj. b Gr*«AAU tmIcIh, from wbluh ihd
•g( kw Jdii k*** dl»hart*d r Tiilh. tmarlnf nppvr vsiramltf ol oridatl. il, « ftnuut) dliMun
•( »rl4Ml, la vhleh ehtlutraraui nacabruk«. ebkUia, and klburuad kr« tiirmid. /. Tbird patitos,
!• vblcb tha ibron* nbell mtaibtkniH ar* pruilafnl. g. Toitnb poriloD Ul<l opaa. ihuwlDc nii( ci>Bt-
f\»UtT t«rBM4, Willi aMMf^Tn* akwlL K Xmnv ta«>l tbrMfh 1*bltb lb* •(■ )■ dMob^r^.

586

EaO AND FBMALB ORGAlfS 07 GKNERATIOir.

rating them from each other, and forming s cavity or air-cbamber
ig\ which is always found betweeo the two fibroua mcrabranos at
tho roanded end of iho e^g. Next we come to the albumen or
"white" of the egg ((0; ntxi to the chalaziferous membraoe and
chalazce (c); and fiaaHy to the vitelliDO membrane {b) inclosing the

Ff(t. i&i.

Dlagrani at F<i<ri,'* Biio.— a Talh. b. Vliel.llDo Dembna* c. (TltaUilfariMta uMnhfaa* 4.

yolk (a). After the expulaion of the egg, the external layers of the
albumea liquefy; and the vitellus, being specifioally lighter than
the albumen, owing to the large proportion of oleaginous matter
which it contuins, riseH toward the surfuce of the egg, with the cica-
tricula uppermost. This part, therefore, presents itself almost im-
mediately on breaking open the egg upon ita lateral sarfaoe, and u
placed in the moat favorablo position for the action of warmth and
atmo»phcrtc air in the development of the chick.

The vitellua, therefore, is still the essential and constitaent porUon
of the egg ; while all the other parts consist either of nutritious mate-
rial, like the albumen, provided for the support of the embryo, or
of protective envelopes, like the shell and the 6brous membranes.

In thequadrupeds, another and still more important modiBoation
of the oviducts takes place, lo these animals, the egg, which is
originally very minute in size, is destined to be retained witbia the
generative passages of the female during tho development of the
embryo. While the upper part of the oviduct, therefore, is quite
narrow, and intended merely to transmit the egg from the ovary,
and to supply it with a little albuminous secretion, its lower por*
lions are very rauob increased in size, and are lined, moreover, witb

■GO AND FKUALS ORGANS 07 GSKKBATION. 587

a macotu membrane, so constructed as to provide for the protection
and nourishmeDt of the embryo, during the entire period of gesta-
tAon. The opper and narrower portions of the oviduct are known
as the "Fallopian tubes" (Fig. 182); while the lower and more

Fig. 182.

Utbici asd Otakibi or tbi Snw.-
■unw. d. Bodjr of nUru, t. Vafloa.

, A. OtuIm. b, b. FftllopUo robM. c. e Horai of

bighlj developed portions constitute the uterus. These lower por-
tions unite with each other upon the median line near their infe-
rior termination, ao as to form a central organ, termed the "bod;"
of the uterus; while the remaining ununited parts are known as
its "oornua," or "boms."

In the baman subject, the female generative apparatus presents
the following peculiarities. The ovaries consist of Graafian follicles,
which an imbedded in a somewhat dense areolar tissue, supplied
with an abundance of bloodvessela The entire mass is covered
with a thick, opaque, yellowish white layer of fibrous tissue called
the "albugineons tunic " Over the whole is a layer of peritoneum,
which is reflected upon the vessels which supply the ovary, and is
continuous with the broad ligaments of the uterus.

The oviducts commence by a wide ezpansion, provided with
fringed edges, called the "fimbriated extremity of the Fallopian
tube." The Fallopian tubes themselves are very narrow and con-
voluted, and terminate on each side in the upper part of the body
of the uterus. In the human subject, the body of the uterus is so
mooh developed at the expense of the cornua, that the latter hardly
appear to have an existence; and in fact no trace of them is visible
externally. But on opening the body of the uterus its cavity is
seen to be nearly triangular in shape, its two superior angles run-
ning oat on each side to join the lower extremities of the Fallopian
tubes. This portion evidently consists of the cornua, which have

6S8

ROa A.irB FSMALB OROANS OT GBNEBATIOS.

been vonaolidated vr\lh the body of iho uterutt, aad eoTeloped io.
ita tliickeDdd layer of musoulur fibres.

Fig. I&3.

'--a.

Oii>«m>«iv> 0*iii<r« or Ilea** Pbmai.i.— a,
a. Biid7 of Blatva. il. Cvrvli. «. V*i4m.

a. OTkrin. b, b. FmllaptMi nhm.

Tlie cavity of ihc body of the uterus terminates below by a con-
stricted portion lerined the os internam, by which it is se[>iirat«d
from the cavity ot the cervix. These two cavities are not only
difTerent from each other ia sha|}0, but differ aljso ia the structure
of their mucous niembraae and the functions which it ia destined
to perform.

The mucous membrane of the body of the uteros in ita usual
condition is smooth and rosy in color, and closely adherent to the
subjacent muscular tissue. It consii^ls of minute tubular follicles
somewhat similar to those of the o^tric mucoua membrane, ranged
side by side, and opening by distinct orifices upon ita free aurfaoe-
The secretion of these fullicles is destined for the nutrition of th«
embryo during the earlier periods of its formation.

The internal surface of the necic of the uterus, on the other hand,
is raided ia prominent ridgoa, which are arranged nsoally in two
lateral seta, diverging from a central longitudinal ridge; presenting
the appearance known aa the "arbur vitas uterina." The folliclna
of this part of the uterine mucous membrane are different in struc-
ture from those of the foregoing. They are of a globular or sac-
like form, and secrete a very firm, adhesive, tratuparent mucus,
which is destined to block up the cavity of the cervix during gee*

XOa AND TEICALK ORGANS OF OXNKBATION. 639

tatkm, tad goard sgainat the accidental diaplaoement of the ^g.
Some <A these foUiclee are freqaenily distended with thor secretion,
and project, as small, hard, rounded eminences, from the surface
of the mucous membrane. In this condition they are sometimes
designated bj the name of "ovula Nabothi," owing to their having
been formerly mistaken for eggs, or ovules.

The cavity of the cervix uteri is terminated below by a second
constriction, the "oe externum." Below this comes the vagina,
which constitutes the last divifflon of the female generative pas-
sages.

The accessory female organs of generation consist therefore of
ducts or tubes, by means of which the egg is conveyed from within
oatward. These ducts vary in the degree and complication of
their development, according to the importance of the task assigned
to them. In the lower orders, they serve merely to convey the egg
rapidly to the exterior, and to supply it more or less abundantly
with an albuminooB secretion. In the higher classes and in the
human subject, they are adapted to the more important function of
retaining the egg during the period of gestation, and of providing
daring the same time for the nourishment of the young embryo.

940

MALE ORGANS OF OENKRATIOK.

CHAPTER IV.

ON THE SPERMATIC FLUID, AND THE MALE OROAXS
OF OENEBATION.

The mature egg is not by itself capable of being developed into
the embryo. If simply discharged from ibe ovary and carried
through the oviducts toward the exterior, it soon dies and is de-
composed, like any other portion of the body separated from its
natural connections. It is only when fecundated by the spermatic
flaid of the male, that it is stimulated to continued developmeot,
and becomes capable of a more complete organization.

The product of the male generative organs consists of a colorless,
flomewhat viscid, and albuminous fluid, containing an innumerable
quantity of minute filamentous bodies, termed spermalosoa. The
name spermatozoa has been given to these bodies, on account of
their exhibiting under the microscope a very active and oontina-
ous movement, bearing some resemblance to that of certain anitool-
cules.

The Bpormato7X)a of the human subject (Fig. 184, a) are about
ifirof an inch iu length, according to the measurements of Kul-
liker. Their anterior extremity presents a somewhat flattened,
triangular-Aliaped ciilar^mont, termed the "head." The head coa-
stitutea about one-tenth part the entire length of the spertnalo-
zoon. The remaining portion is a very slender filamentous pro-
longation, termed the "tail," which tapers gradually backward,
becoming so exceedingly delicate toward its extremify, that it is
difficult to be seen except when in motion. There Is no further
organization or internal structure to be detected in any part of the
spermatozoon; and the whole appears to consist, so far as can be
seen by the microscope, of a completely homogeneous, tolerably
firm, albuminoid substance. The terms head and tail, therefore,
as justly remarked by Bergmann and Tjcuckart,' are not uned,
when describing the different parts of the spermatozoon, in the
same sense as that in which they would be applied to the corn*

■ Yerffleiclitiiide Phyilologie. Slattgmrl, 1S53.

HALE OBOAXS 07 GEXEKATIOS^.

541

apoodiag parta of an anima], but simply for tbe sake of convenl*
ence; just as one migbl speak of the head of an arrow, or the tail
of a comet.

Id the lower animals, the spermatozoa have nsvallj the same
general form as in tbe human subject; that is, they are slender
filamentous bodies, with the anterior extremity more or less en-
larged. In the rabbit they have a head which is roundish and
flattened in shape, somewhat resembling the globulea of the blood.
In the rat (Fig. 184, b) they are much larger than in man, measur-
ing nearly j^^ of an iuch in length. The head is conical iu shape,

Pig. 184.

trtmukJUt^A.

Hmnfto AOrR*t. «. Of lleD«brkD«hiak. lb««tB«d Un IIbm.

a'bout ooe-lwentieth the whole length of the filament^ and oflen
slightly carved at ita anterior extremity. In the frog and in rep-
tiles generally, the spermatozoa are longer than in quadrupeds.
In the Menobranchus. or great American waler-lizanl, they are of
very unusual size (Fig. im, c), measuring not less than ^'^ of an
inch in lengih, about one-third of which is occupied by tbe bead,
or enlai^ed portion of the filament.

542

MAl

ORGANS OF GClTBItATIOl

The most remarkable peculiarity of the Bpermalozoa is tlietr
very singular aud active movement, to which we have already
alluded. If a drop of fresh eemtiial tt\^\i^ be placed under the
microscope, the oumberlesB minute filamcDta with which it is
crowded arc seen to be in a state of incessant and agitated motion.
Tbia movement of the spermatozoa, id many spocies of animals,
strongly resembles that of the tadpole; particularly when, as in the
human subject, the rabbit, &c., the spermatosna consist of a short
and welt defined head, followed by a long and slender tail. Here
the tail-like filament keeps up a constant lateral or vibratory moTe-
ment, by which the spermatozoon ie driven from place to place in
the spermatic fluid, Juttt as the fish or the tadpole is propelled
through the water. In other instances, as for example in the water-
lizard, and in some parasitic animals, the spermatozoa have a eon-
UnnouB writhing or spiral-like movement, which presents a very
peculiar and elegant appearance when large numbers of tbem are
viewed together.

It is the existence of this movement which first suggested the
name of spermatozoa to designate the animated filamenLs of the
spermatic fluid; and which has led some writers to attribute to
them an iadepeodent animal nature. This is, however, a very
erroneous mode of regarding them; since they cannot proi>erly be
considered as animals, notwithstanding the active character of their
movement, and the striking resemblance which it sometimes pre-
sents to a voluntary act. The spermatozoa are organic fortius
which are produced in the testicles, and constitute a part of their
tissue; just as the eggs, which are produced in the ovaries, natn*
rally form a part of the texture of these organs. Like the egg,
also, the spermatozoon is destined to be discharged from the organ
where it grew, and to retain, fur a certain length of time aflerward,
its vital projiorties. One of the most peculiar of these properiica
is its power of keeping in constant motion; which does not, how-
ever, mark it as a distinct animal, but only distinguishes it as a
peculiar structure belonging to the parent organism. The motion
of a spermatozoon is precisely analogous to that of a ciliated epi-
thelium cell. The movement of the latter will continue for aome
hours after it has been separated from its mucous membrane, pro-
vided its texture be not injured, nor the process of decomposition
allowed to commence. In the same manner, the movement of the
spermatozoa is a characteristic property belonging to them, which
continues for a certain time, even after they have been separated
from all connection with the rest of the body.

XALK OBOANS OF 6SNXRA.TI0y. fi48

In order to preserre their vitality, the spermatozoa maat be
kept at the ordinary temperature of the body, and preserved
from the contact of the air or other unnatural Baids. In this way,
tbey may be kept without difficulty many hours for purposes of
exarolDation. But if the fluid in which they are kept be allowed
to dry, or if it be diluted by the addition of water, in the case of
birds and qaadrapeds, or if it be subjected to extremes of heat or
cold, the motion ceases, and the spermatozoa themselves soon begin
to disiat^^rate. *

The spermatozoa are produced in certain glandular-looking
oi^gans, the lesticlea^ which are characteristic of the male, aa the ova-
ries are characteristic of the female. In man and all the higher
animals, the testicles are solid, ovoid-shaped bodies, composed
priocipaUy of numerous long, narrow, and convoluted tubes, the
" seminiferous tubes," somewhat similar in their general anatomical
characters to the tubuli uriniferi of the kidneys. These tubes lie
for the most part closely in contact with each other, so that nothing
intervenes between them except capillary bloodvessels and a little
areolar tissue. They commence, by blind, rounded extremities, near
the external surface of the testicle, and pursue an intricately con-
Tolated course toward its central and posterior part. They are not
strongly adherent to each other, but may be readily unravelled by
manipulation, and separated from each other.

The formation of the spermatozoa, as it takes place in the
substance of the testicle, has been fully investigated by Kolliker.
According to his observations, as the age of puberty approaches,
beside the ordinary pavement epithelium lining the seminiferous
tnbes, other cells or vesicles of larger size make their appearance
in these tubes, each containing from one to fifteen or twenty nuclei,
with nucleoli. It is in the interior of these vesicles that the sper-
matozoa are formed ; their number corresponding usually with that
of the nuclei just mentioned. They are .at first developed in bundles
of ten to twenty, held together by the thin membranous substance
which surrounds them, but are afterward set free by the liquefac-
tion of the veaicle, and then fill nearly the entire cavity of the
seminiferous ducts, mingled only with a very minute quantity of
transparent fluid.

In the seminiferous tubes themselves, the spermatozcw are al-
ways inclosed in the interior of their parent vesicles; they are libe-
rated, and mingled promiscuously together, only afler entering the
rete testis and the head of the epididymis.

644

HALE ORGANS OP GBNBRATTOW.

Cesidc tlic testicles, wbich are, as above stated, tlie primary fitiil
essential parta of the male geaemtive apparatus, there arc certain
secondary or accessory organs, by means of which the sperraatic
fluid is conveyed to the exterior, and mingled with varioas secre-
tioDS which assist ia the accomplishment of its functions.

As the sperm leaves the testicle, it consiatA, as above mentioned,
almost entirely of the spermatozoa, crowded together in an opaque,
white, semi-fluid mass, which fills up the vasa eflfercntia, and com-
pletely distends their cavitica. It then enters the single duct which
forms the hoi\y and lower extremity of the epididymis, following
the long and tortuous course of tliis tube, until it becomes con-
tinuous with Lbs vas deferens; through which it is still conveyed
onward to the point whore this canal opens into the urethra.
Throaghoat this course, it is mingled with a glairy, mucng like
fluid, secreted by the walls of the epididymis and vas defereus, ia
which the S]>ermatozoa are enveloped. The mixture is then depo-
sited in the veeiculro seminaloa, where it accumulates as fresh quail-
lilies are produced in the testicle and conveyed downward by the
spermatic duct. It is probable that a second secretioD is supplied
also by the internal surface of the vesioulw semioalea, and that the
sperm, while retained in their cavities, is not only stored up for
subsequent use, but is at the same time modiSed in its properties
by the admixture of another fluid.

At the time when the evacuation of the sperm takes place, it ia
driven out from the seminal vesicles by the muscular contraction
of the surrounding parts, and meets in the urethra with the secre*
tions of the prostate gland, the glands of Cowper, and the mucoaa
foUiclea opening into the urethral passage. All these organs are at
that time excited to an unu.sua! activity of secretion, and pour oi;
their different fluids in great abundance.

The sperm, therefore, as it is discharged from the urethra, is
exceedingly mixed fluid, consisting of the spermatozoa derived
from the testicIcSf together with the secretions of the epididymis
and vas deferens, the prostate, Cowper's glands, and the mucous (cA-
licles of the urethra. Of all these ingredients, it is the spermatozoa
which constitute the essential part of the seminal fluid. They are
the true fecundating clement of the sperm, while all the others are
eecondary in importance, and perform only accessory functions.

Spallanzani found that if frog's semeu be passed through a sgc-
oeesioD of flltere, so as to separate the spermatozoa from the liquid
portions, the Altered fluid is destitute of any fecundating properties;

KALK OROANS OF OEKKRATIOK. 646

while the spermatozoa remaining entangled in tbe filter, if mixed
with a snfficient quantity of fluid of the reqaisite density for dila-
tion, may atill be Bacoessfhlly used for the impregnation of eggs.
It is well known, also, that aoimals or men from whom both testi-
cles have been removed, are incapable of impregnating the female
or her eggs; while a removal or imperfection of any of the other
graeratire organs does not necessarily prevent the accomplish meat
of the fnnction.

In most of the lower orders of animals there is a periodical
development of the testicles in the male, corresponding in time with
that of the ovaries in the female. As the ovaries enlarge and the
eggs ripen in the one sex, so in the other the testicles increase in
size, as the season of reproduction approaches, and become tnrgid
with spermatozoa. The accessory organs of generation, at the
same time, share the unusual activity of the testicles, and become
increased in vascularity and ready to perform their part in the
reproductive function.

In the fish, for example, where the testicles occupy the same
position in the abdomen as the ovaries in the opposite sex, these
bodies enlarge, become distended with their contents, and project
into the peritoneal cavity. Each of the two sexes is then at the
same time nnder the influence of a corresponding excitement The
unusual development of the generative organs reacts upon the entire
system, and produces a state of peculiar activity and excitability,
known as the condition of "erethism." The female, distended with
6^8, feels the impulse which leads to their expulsion; while the
male, bearing the weight of the enlarged testicles and the accnmu-
lation of newly -developed spermatozoa, is impelled by a similar
sensation to the discharge of the spermatic fluid. The two sexes,
aooordingly, are led by instinct at this season to frequent the same
sitoations. The female deposits her eggs in some spot favorable
to the protection and development of the young; aAier which the
male, apparently attracted and stimulated by the sight of the new-
liud eggs, discharges the spermatic fluid upon them, and their
impregnation is accomplished.

In such instances as the above, where the male and female gene-
rative products are discharged separately by the two sexes, the
aubsoquent contact of the eggs with the spermatic fluid would seem
to be altogether dependent on the occurrence of fortuitous circum-
stances, and their impregnation, therefore, often liable to fail. In
point of fact, however, the simultaneous functional excitement uf
So

MALI OROAys or QKySRATTOTT.

the two sexes and the opera^OD of oorrespoodiog instiocte, leading
them to asocnd the same rivers and to frequent, the aatne spots,
provide with sufficient certainty for the impregnation of the egg«.
In these animals, also, the number ot eggs produced bj the female
is very large, the ovaries being oflca so distended as to fill nearly
the whole of the abdominal oarity; so that, although many of the
eggs may be accidentally lost, a sufficient number will still be im'
pregnated and developed, to provide for tbe coDtinuation of the
ftpecios.

In other instances, an actual contact takes place between the
sexes at the lime of reproduction. In the frog, for example, the
male fastens himself upon the back of the female by the anterior
extremities, which seem to retain their hold by a kind of spasmodic
contractioQ. Thia continues for one or two days, during which
time the mature eggs, which have betm discharged from the ovary,
are passing downward through the oviducts. At last they are ex>
pelled frotn the anus, while at the same time tbe semioal fluid of
the male is discharged upon them, anil impregnation takes place.

In the higher claftses of animals, however, and in man, where the
egg is to be retained in the body of the female parent daring tta
development, the spermntic fluid is introduced into tbe female
generative passages by sexual congreM, and meets tbe egg at or
soon after its discharge from tbe ovary. The same oorrespoodenoe,
however, betwecQ the periods of sexual excitement in the male and
female, is visible in many of these animals, as well as in fish and
reptiles. This is the case in most species which produce young but
ouoQ a year, and at a ^xed period, as the deer and the wild hog. Id
other species, on the contrary, such as the dog, as well as the rabbit,
the guinea pig, &c., where several broods of young ara prodoced
during the year, or where, as in the human subject, the generative
epochs of the female recur at short intervals, so that the particular
period of impregnation is ccmpanitively indefinite, the generaVive
apparatus of the male is almost constantly in a stale of full deve-
lopment; and is excited to action at particular periods, apparently
by some Influence derived from the condition of the female.

In the quadrupeds, accordingly, and in the human apecica, tbe
contact of the sperm with tbe egg and the fecundation of ihc latter
lake place in the generative pasi^ages of the female; either in the
uterus, the Fallopian tubes, or oven ujion the surfocc of the ovary;
in each of which situations the sperniaioi»>a have been found, aAer
the acoomplisbmeut of sexual inlercourbe.

PSBIODIGAL OVULATION. 547

CHAPTER V.

ON PERIODICAL OVULATION, AND THE FUNCTION
OP MENSTRUATION.

I. PERIODICAL OVULATION.

Wb have already spoken in general terms of the periodical ripen-
ing of the eggs and their discharge from the generative organs of
the female. This function is known by the name of "ovnlation,"
and may be considered as the primary and most important act in
the process of reprod action. We shall therefore enter more fully
into the consideration of certain particulars in regard to it, by
which its nature and conditions may be more clearly understood.

1st. Eggs exiat originally tn the ovartea of all animaU^ as part of
their natural atrueiure. In describing the ovaries of fish and reptiles
we have said that they consist of nothing more than Graafian vesi-
cles, each vesicle containing an egg, and united with the others by
loose areolar tissue and a peritoneal investment. In the higher
animals and in the human subject, the essential constitution of the
ovary is the same; only its fibrous tissue is more abundant, eo that
the texture of the entire organ is more dense, and its figure more
compact In all classes, however, without exception, the interior
of each Graafian vesicle is occupied by an egg; and it is from this
egg that the young offspring is afterward produced.

The process of reproduction was formerly regarded as essentially
different in the oviparous and the viviparous animals. In the ovipa-
rous classes, such aa most fish, and all reptiles and birds, the young
animal was well known to be formed from an egg produced by the
female; while in the viviparous animals, or those which bring
forth their young alive, such as the quadrupeds and the human
species, the embryo was supposed to originate in the body of the
female, by some altogether peculiar and mysterious process, in
consequence of sexual intercourse. As soon, however, as the
microscope began to be used in the examination of the tissues,

548 OVUI>ATIOIT AITD FUNCTIOX OF MKUSTBUATIOy.

the ovaries of quadrupeds were also found to contain eggs. ThesS'
egga bad previously escaped observation on account of their simple
structure and minute aizc; but they were nevertheless found to'
possess all the most essential uharactere belonging to the larger
eggs of the oviparous animals, M

The true diflbrcn&c in tlio process of reproduction, between theV
two classes, is therefore merely an apparent, not a fundamentAl one.
In lish, reptiles, and birds, the egg ia discharged by the female
before or immediately after impregnation, and the embryo is subse-
quently developed and hatched externally. In the quadrupeds and
the human species, on the oihcr hand, the egg is retain«l within
the body of the female until the embryo is developed; when the
membranes are ruptured and the young expelled at the same time.
Id all classes, however, viviparous as well as oviparous, the young
is produced equally from an egg; and in all classes the egg, some-
times larger and sometimes nmaller, but always consisting essentially
of a vitellus and a vitelline membrane, is contained originally iufl
the interior of an ovarian follicle.

The ogg is accordingly, as we have already intimated, an iategral
part of the ovarian tissue. Jt may be found there long before the
generative function is established, and during the earliest periods
of life. It may be found without difficulty in the newly born
female infant, and may even be detected in the ftutus before birih.
Its growth and nutrition, also, are pruvidetl fur in the same man-
ner with that of other portions of the bodily structure.

2d. Thfse eggs btcome more fully developed at a certain a^ when
Uis generative function ia tUMnii to he estahiishnL During the early
periods of life, the ovaries and their contents, like many other
organs, are imperfectly develo|>ed. They oxiflt, but they are as
yet inactive, and incapable of performing any function. In the
young chick', for example, the ovary is of small size; and the eg^
instead of presenting the voLumtuous, yellow, opaque vitellus which _
they af^rward exhibit, are mioule, transparent, and colorless. In ■
the young quadrupeds, and in the human female during infancv
and childhood, the ovaries are equally inactive. They are small,
friable, and of a nearly homogeneous appearance to the naked eye;!
presenting none of the enlarged ruUiules, filleil with tmosparentj
fluid, which are afterward so readily distinguished. At this time, ,
accordingly, the female is incapable of bearing young, because thtfj
ovaries are inactive, and the eggs which they contain immature.

At a certain period, however, which varies in the time of its

PERIODICAL OVOLATlOy. 649

occarrence for diCferent species of animals, the sexual apparatus
begins to eoter upon a state of actiritj. The ovaries increase in
lise, and their circulation becomes more active. The eggs, also,
instead of remaining quiescent, take on a rapid growth, and the
structure of the vitellus is completed by the abundant deposit of
oleaginous granules in its interior. Arrived at this state, the eggs
are ready for impregnation, and the female becomes capable of
bearing young. She is then said to have arrived at the state of
"puberty," or that condition in which thd generative organs are
fully developed. This condition ia accompanied by a visible
alteration in the system at large, which indicates the complete
development of. the entire organism. In many birds, for example,
the plomage assumes at this period more varied and brilliant
oolors; and in the common fowl the comb, or "crest," enlarges
and becomes red and vascular. In the American deer (Cervus
Tirginianus), the coat, which during the first year is mottled with
white, becomes in the second year of a uniform tawny or reddish
tinge. In nearly all species, the limbs become more compact and
the body more rounded; and the whole external appearance is so
altered, as to indicate that the animal has arrived at the period of
puberty, and is capable of reproduction.

Sd. Sueeeaaive crops of eggs, in the adult female, ripen and are
dtmiharged mdependently of sexual intercourse. It was formerly sup-
poeed, as we have mentioned above, that in the viviparous animals
the germ was formed in the body of the female only as a conse-
quence of sexual intercourse. Even after the important fact
became known that eggs exist originally in the ovaries of these
animals, and are only fecundated by the in6uence of the sperm-
atic fluid, the opinion still prevailed that the occurrence of sexual
intercourse was the cause of their being discharged from the ovary,
and that the rupture of a Qraafian vesicle in this organ was a
certain indication that coitus had taken place.

This opinion, however, was altogether unfounded. We already
know that in fish and reptiles the mature eggs not only leave the
ovary, but are actually discharged from the body of the female
while still unimpregnated, and only subsequently come in contact
with the spermatic fluid. In fowls, also, it is a matter of common
observation that the hen will continue to lay fully-formed eggs, if
well supplied with nourishment, without the presence of the cock;
only these eggs, being unimpregnated, are incapable of producing

660 OTCLATIOW AXD FUNCTtOrT OF UKNSTRCATIOK.

chicks. In oviparous animals, thcrcrore, the disriharge of the egg,
03 well as its formation, is intlependent of sexual intercourse. m

Cuiitioucd observation shows this to be the ca««, also, in thoS
vivi|)arou8 quadrupeds. The researches of BischofT, Pouchet, and
G'Me have doinonstralod that in Ihu elieep, the pig, the bitch, tbe
rabbit, &c., if the female be carefully kepi from the male until after ^
tbe period of puberty is established, aud then killed, examinatioafl
of the ovaries will show that Oraafiau vesiules have matured, rup-
tured, and diacharged their eggs, in the same manner as though
sexual intercourse had taken place. Sometimes the vesicles are
found distended and prominent upon the surface of tbe ovary;
sometimes recently ruptured and collapsed; aud sometimes in vari-
ous stages of cicatrization and atrophy. Bischofi*,' in several in-
stances of this kind, actually found the unimpregnated eggs in the
oviduct, on their way to the cavity of the nterus. In those animals
in which the ripening of tbe eggs takes place at short intervals, as,
for example, the sheep, the pig, and the cow, it is very rare to exa-
mine the ovaries in any instance where traces of a more or less
recent rupture of the Graafian fi^llicles are not distinctly visible.

One of the most important facts, derived from the examination
of such cases as the above, is that the ovarian eggs Iwcome deve-
lopeil and are discharged in 8ucees!>ive crops, which follow each
other regularly at periodical intervals. If we examine the ovary
of the fowl, for example (Fig. 180), we see at a glance how the eggs
grow and ripen, one after tbe other, like fruit upon a vine. In thii
instance, the process of evolution Is very rapid ; and it is easy to
distinguish, at the same time, eggs which are almost microscopic itfl
size, colorless, and transparent; those which are larger, firmer,
somewhat opaline, aud yellowish iu hue; and finally those which
are fully developed, opaque, of a deep orange color, and jaat ready
to leave the ovary.

It will be observed that in this instance the difference between
the undeveloped and the mature eggs consists principally in the
size of the vitellus, which is furthermore, for reasons previously
given (Chap. III.), very much larger than in the quadrupeds. It
is also seen that it is the increased si7,e of the vitellus alone, by
which the ovarian follicle is distended aud ruptured, and the egg
linnlly discharged.

In the human species and the quadrupeds, on the other hand,

■ H^nir*! iurlapliut«> [)6rlo<l!<)Ue da I'anf, &c., AtUtalMdMSctencM Natarvllal, ,

PEBIODICAL OVULATION. 651

the microecopic egg never becomes large enough to diateod the
follicle by its own size. The rupture of the follicle and the libera-
tion of the egg are accordingly providedfor, in these instances, by
a totally different mechanism.

In the earlier periods of life, in man and the higher animals, the
^g is contained in a Graafian follicle which closely embraces its
exterior, and is consequently hardly larger than the egg itself. As
puberty approaches, those follicles which are situated near the free
surface of the ovary become enlarged by the accumulation of a
colorless serous ^uid in their cavity. We then Ond that the ovary,
when cut open, shows a considerable number of globular, transpa-
rent vesicles, readily perceptible by the eye, the smaller of which
are deep seated, but which increase in size as they approach the
free surface of the organ. These vesicles are the Graafian follicles,
which, in consequence of the advancing maturity of the eggs con-
tained in them, gradually enlarge as the period of generation ap-
proaches.

The Graafian follicle at this time consists of a closed globular
sac or vesicle, the external wall of which, though quite translucent,
has a fibrous texture under the microscope and is well supplied
with bloodvessels. This fibrous and vascular wall is distinguished
by the name of the "membrane of the vesicle." It is not very
firm in texture, and if roughly handled is easily ruptured.

The membrane of the vesicle is lined throughout by a thin layer
of minute granular cells, which form for it a kind of epithelium,
similar to the epithelium of the pleura, pericardium, and other
serous membranes. This layer is termed the mem^ana granulosa.
It adheres but slightly to the membrane of the vesicle, and may
easily be detached by careless manipulation before the vesicle is
opened, being then mingled, in the form of light flakes and shreds,
with the serous fluid contained in the vesicle.

At the most superficial part of the Graafian follicle, or that
which is nearest the surface of the ovary, the membrana granulosa
is thicker than elsewhere. Its cells are here accumulated, in a
kind of mound or "heap," which has received the name of the
eumuluB proligenu. It is sometimes called the discus proligerus,
because the thickened mass, When viewed from above, has a some-
what circular or disk-like form. In the centre of this thickened
portion of the membrana granulosa the egg is imbedded. It is
accordingly always situated at the most superficial portion of the
follicle, and advances in this way toward the surface of the ovary.

662 OVULATION AND F03

rsTBUATIOK.

An the poriod approaches at which the egg is destined to be dis-
chftrged, the Graafian foUiclc bccoiiies more vascular, and enlarges
by an increased exudatioa of serum into its cavity. It Lbeu begiiu

Ql 4«rl * V FoLMCL*. OMf Ihr J : iiiTP— a Hrint>ranac4tl>* rnWlA ft. Mambfua

(namlii*a. e. Cavil/ «r Ivlllclr. d. X^ ^ 1 LiiLuaenu. /. Tiwlea uAug^arm g, g. Tlwua ■4

to project frym the Burfuce of the ovary, still covered by the olbu-
gioeous tunic and the i^ritoneum. (Fig. IfSo.) The constant accu-
mulation of fluid, however, in the fullicle, exert-s such a steady and
increasing pressure from within outward, that the albugineous tuiuu
and the peritoneum successively yield before it; until tbeUraafian
foUiclo protrudisi from the ovury as a tense, rounded, truuslucem
vesicle, in which the sense of fluctuation can be readily perceived
on applying the Angers to its surface. Finally, the process of eSti-
sion and distension still going on, the wall of iho vesicle yields at
its most prominent porUon, the contained fluid is driven out with a
gush, by the reaciiun and oinsticity of the neighboring ovarian

tissues, onrrying with it tbe egg,

Pig. 188.

OTAnr WITH aM**ri4> rntLiri. >
kcrTCBE*: >t n. ^ci ln*l iH-chartrd slili •
pvnlaa at tnaiubraiiB gniialiiwi.

Still entangled in the cells of the
proligeruus disk.

The rupture of the Graaflan
vesicle is accompanied, in some
instances, by an abundant hemor-
rhage, which takes place from the
internal surface of the congested
follicle, and by which its cavity
is filled with blood. Thisoocura
in the human subject and in the
pig, and to a certain extent, also,
in other of the lover animals.
Sometimes, as in the cow, wher«

PBBIODICAL OVULATION. 668

no liemorrbage takes place, the Graadan vesicle when raptured
simplj collapses ; after which, a slight exadation, more or less tioged
with blood, is poared out during the coarse of a few hours.

Notwithstanding, however, these slight variations, the expulsion
of the egg takes place, in the higher animals, always in the maoDer
above described, viz., by the accumulation of serona fluid in the
cavity of the GraaBao follicle, by which its walls are gradaally dis-
tended and finally raptored.

This process takes place in one or more Graafian follicles at a
time, according to the number of young which the animal produces
at a birth. In the bitch and the sow, where each litter consists of
from six to twenty young ones, a similar number of eggs ripen and
are discharged at each period. In the mare, in the cow, and in the
human female, where there is usually but one fcetus at a birth, the
eggs are matured singly, and the Graafian vesicles ruptured, one
afier another, at successive periods of ovulation.

4th. The ripming and discharge of the egg are accompanied by a pecu'
liar eonditwn of the entire eyatem, knoun eu the ** rutting" eonditwn, or
" aalrvatwn." The peculiar congestion and functional activity of
the ovaries at each period of ovulation, act by sympathy upon the
other generative or^uis, and produce in them a greater or less de-
gree of excitement, according to the particular species of animal.
Almost always there is a certain amount of congestion of the entire
generative apparatus ; Fallopian tubes, uterus, vagina, and external
organs. The secretions of the vagina and neighboring parts are
more particularly aflected, being usually increased in quantity and
at the same time altered in quality. In the bitch, the vaginal mu-
cous membrane becomes red and tumefied, and pours out an abun-
dant sepretion which is often more or less tinged with blood. The
secretions acquire also at this time a peculiar odor, which ap-
pears to attract the male, and to excite in him the sexual impulse.
An anusaal tumefaction and redness of the vagina and vulva are
also very perceptible in the rabbit; and in some species of apes it
has been observed that these periods are accompanied not only by
a bloody discharge from the vulva, but also by an engorgement and
infiltration of the neighboring parts, extending even to the skin of
the buttocks, the thighs, and the under part of the tail.'

The system at large is also visibly affected by the process going
on in the ovary. In the cow, for example, the approach of an

■ PoDcbet, Tbiorie poaitivt) d« t'ovaUlion, &o. Paria, lb47, p. 230.

554 ovuLA*

FUNCTION OF MEN'STRDATIOK.

osstruat period is marked by nn unusual rcstlcwsness and ngiiatinn,
easily recogniised by an urdJnary observer. The animal partially
loses her appetite. She frequently stops browsing, looks about aD>
easily, perhaps runs from une side of the Beld to the other, and then
recommcticcs feeiting, to be disturbed again in a similar manner
al\er a short interval. Her motions are rapid and nervous, and ber
hide alien rough aud disordered; and the whole aspect of. the ani-
mal indicates the presence of some unusual excitement. After this
condition is fully established, the viiginal secretions show them-
aelvca in unusual abundance, and so continue for one or two dayt;
ader which the symptoms, both local and general, subside sponta-
Qoously, and the animal returns to her usual condition.

It is a remarkablo fact, in this connection, that the female of
these animals will allow the approaches of the malo only during and
immediately after the cestrual period ; that is, just when the egg is
roceatly di6c:harged, and ready for impregnation. At other times,
when sexual intercourse would be necessarily fruitless, the instinot
of the animal leads her to avoid it; and the concourse of ibe sexes
is accordingly made to correspond in time with the maturity of i
egg and its Bj}titude for fecundation.

II. MEXSTRUATIOK.

In the hnman female, the return of the periods of ovulation is
marked by a peculiar group of phenomena which are known 80
memiruatwn, and which are of siifficient imporlanco to be described
by themselves.

During infancy and childhood the sexual system, u we have
mentioned above, is inactive. No discharge of eggs takes place
from the ovaries, and no external phenomena show themselves,
connected with the raproduetive function.

At the age of fourteen or fifteen years, however, a change begins
to manifest itself. The limbs become rounder, the breasts increaae
in size, and the entire aspect undergoes a ]>eculinr alteration, which
indicates the approaching condition of maturity. At the same
time a discharge of blotxl takes place from the generative passages,
accompanied by some disturbance of the general system, and the
female is then known to have arrived at the period of puberty.

Afterwartl, the bloody discharge just spoken of returns at regular
intervals of four weeks; and, on ocoount of this recurrence corres'
ponding with the passage of successive lunar months, its phenomena

XKIfSTBUATION. fifiS

are designated hj the name of the "menses" or the ^'menstrual
periods." The menses return with regularity, from the time of
their first appearance, until the age of about fortj-five years.
During this period, the female is capable of bearing children, and
sexaal intercourse is liable to be followed by pregnancy. After
the forty-6f^h year, the periods first become irregular, and then
cease altogether; and their final disappearance is an indication that
the woman is no longer fertile, and that pregnancy cannot again
take place.

Even daring the period above referred to, from the age of fifteen
to forty-five, the regularity and completeness of the menstrual
periods indicate to a great extent the aptitude of individual females
for impregnation. It is well known that all those causes of ill
health which derange menstruation are apt at the same time to
interfere with pregnancy ; so that women whose menses are habi-
tually regular and natural are much more likely to become preg-
nant, after sexual intercourse, than those in whom the periods are
absent or irregular.

If pregnancy happen to take place, however, at any time during
the child-bearing period, the menses are suspended during the con-
tinuance of gestation, and usually remain absent, after delivery, as
long as the woman continues to nurse her child. They then re-
oommence, and subsequently continue to appear as before.

The menstrual discharge consists of an abundant secretion of
mucus mingled with blood. When the expected period is about
to come on, the female is affected with a certain degree of discomfort
and lassitude, a sense of weight in the pelvis, and more or less dis-
inclination to society. These symptoms are in some instances
slightly pronounced, in others more troublesome. An unusual
discharge of vaginal mucus then begins to take place, which soon
becomes yellowish or rusty brown in color, from the admixture of
a certain proportion of blood ; and by the second or third day the
discharge has the appearance of nearly pure blood. The unpleasant
sensations which were at first manifest then usually subside ; and
the discharge, after continuing for a certain period, begins to grow
more scanty. Its color changes from a pure red to a brownish or
rusty tinge, until it finally disappears altogether, and the female
returns to her ordinary condition.

The menstrual epochs of the human female correspond with the
periods of oestruation in the lower animals. Their general resem-
blance to these periods is too evident to require demonstration.

556 OVULATION AHD PUNCTIOK OF MBSBTBlTATIOy.

Like them, they are abaent in the immature female; and begin
to take phice only at the period of puberty, when the aptitude for
impregnation commences. Like them, they recur during the child-
bearing period at regular intervals; and are liable to the same
interruption by pregnancy and lactation. Finally, their disappear-
ance correspond8 with the ceaeadon of fertility.

The periods of oestruation, furthermore, in many of the lower
animala, arc accompanied, as wc have already aeen, with an unusual
discharge from the generative passages; and this discharge ia fre-
quently more or less tinged with blood. In the human female the
bloody discharge is more abundant than in other instances, but it is
evidently a phenomenon differing only ia degree from that whicli
thows itself in many species of animals.

The most complete evidence, however, that the period of men*
atruation is in reality that of ovulation, is derived from the results
of direct observation. A sufficient number of instances have now
been observed to show that at the menstrual epoch a Graafian
vesicle becomes enliirged, ruptures, and dischsrges its egg. Cruik-
shank' noticed such a case so long ago as I7U7, Neguer* relates
two instances, oommunicated to him by Dr. Ollivier d'Angers, to
which, after sudden death during menstruation, a bloody and rup*
tured Graafian vesicle was Tound in the ovary. Itischoff^ speaks of
four similar cases in his own observation, in three of which the
ve^ele was just ruptured, and iu the fourth distended, prominent,
and ready to burst. Custe* has met with several of the same kind.
Dr. Michel' found a vesicle ruptured and filled with blood in a
woman who was executed for murder while the mensea were pre-
sent. We have also" met with the same appearauces tu a case of
death from aciiLe disease, ou the second day of menstruation.

The process of ovulation, accordingly, id the human female,
accompanies and forms a part of that of menstruation. As the
menstrual period comes on, a congestion takes place iu nearly the
whole of the generative apparatus: in the lallopiun tubes and the
uterus, as well aa in the ovaries and their contents. One of the

' London Philosophiual TransKBtionfl, 1797, p. 13&.
' B«chirrcli«H aur !«<■ (}v»tr<*«, I'nria, IMi', p. 78.

* IlJKt'iiru ilu D«;vQlrjppi>m(<nt <l«fl Corps OrgaTalsSB, Pari*, lt>47, vol. i. p. Stt^^

* Am. Joum. UuA. Sttl., Jiil.r. IM6.

* Corpu* Lulfiuni of Mt?ii«trii&UoH ftnil Prtt$nauojr, in TmoaaoUotix ot Atu«nc*o
HedicJil Aiaociatiijii, I'lilLutpl^liia, It^Sl.

HB17STBUATI0N. 667

Graafian folHcleB ia more especially the seat of an nnnsual vaacutar
ezcitemeDt. It becomeB distended by the fluid which accumulates
in its cavity, projects from the surface of the ovary, and is Snally
rnpfcnred, in the same manner as we have already described this
process taking place in the lower animals.

It is not qaite certain at what particular period of the menstrual
flow the ruptare of the vesicle and discharge of the egg take place.
It is the opinion of BischoCf, Fouchet, and Raciborski, that the
r^alar time for this mptnre and discharge is not at the commence-
ment, but toward the termination of the period. Coste' has ascer-
tained, from his observations, that the vesicle raptures sometimes
in the early part of the menstrual epoch, and sometimes later. So
&T as we can learn, therefore, the precise period of the discharge
of the ^g is not invariable. Like the menses themselves, it may
apparently take place a little earlier or a little later, according to
various .accidental ciroumstances; but it always occurs at some
time in connection with the menstrual flow, and constitutes the
most essential and important part of the oatamenial process.

The egg, when discharged from the ovary, enters the fimbriated
extremity of the Fallopian tube, and commences its passage toward
the uterus. The mechanism by which it finds its way into and
throngh the Fallopian tube is'difierent, in the quadrupeds and the
homan species, and in birds and reptiles. In the latter, the bulk
of the egg or inass of eggs discharged is so great as to flll entirely
the wide extremity of the oviduct, and they are afterward conveyed
downward by the peristaltic action of the muscnlar coat of this
canal. In the higher classes, on the contrary, the egg is raicro-
soopic in size, and would be liable to be lost, were there not some
farther provision for its safety. The wide extremity of the Fallo-
pian tube, accordingly, which is here directed toward the ovary, is
lined with ciliated epithelium; and the movement of the cilia,
which is directed from the ovary toward the uterus, produces a
kind of converging stream, or vortex, by which the egg is neces-
sarily drawn toward the narrow portion of the tube, and subse-
qoently conducted to the cavity of the uterus.

Accidental causes, however, sometimes disturb this regular course
or passage of the egg. The egg may be arrested, for example,
at the surface of the ovary,.and so fKil to enter the tube at alt.
If fecundated in this situation, it will then give rise to "ovarian

■ Loo. cit.

OVULATION AND »0!TCT10N OF MKKSTBUATION.

pregnancy." It may escape from tbe Bmbriated extremity into the
peritoneal oavily, anil furm attatilimonle to some one of tbe neigh-
boring organs, causing "abdominal pregnancy;" or finally, it may
stop at any part of the Fallopian tube, and so give origin to " tubal
pregnaQcy."

The egg, immediately upon its discharge from the ovary, is ready
for impregnation. If sexual intercourse happen to take place about
that time, the egg and the spermatic Said meet in Bome part of the
female generative parages, and fecundation is accomplished. It
appears, from various observations of BiscUoff, Coste, and othera,
that this contact may take place between the egg and the sperm,
either in the uterua or any part of the Fallopian tubes, or even
opoD the surface of the ovary. If, on the other hand, coitus do not
take place, the egg passes down to the uterus unimpregnated, loses
its vitality afler a short time, and is Gually carried away with the
uterine secretions.

It is easily understood, therefore, why sexual intercourse shoQid
be more liable to be followed by pregnancy when it occurs about
the metistrual epoch than at other times. This fact, which vras long
since established as a matter of observation by practical obetetn-
cians, depends siniply upon the coincidence in time between men-
struation and the discharge of the egg. Before its discharge, tbe
^^ is immature, and unprepared for impregnation; and af\er the
menstrual period has passed, it gradually loses its freshness and
vtUility. The exact letigih of time, however, preceding aud follow-
iag the menses, during which impregnation is still possible, has not
been ascertained. Tbe spermatic Quid, on the one hand, retains its
vitality for an unknown period after coition, and the egg for ao
unknown period after its discharge. Both these occurretices may,
therefore, either precede or fiillow each other within certain limits,
and impregnation be still possible; but the precise extent of these
limiu is siill uncertain, and is probably more or Leea variable in
different individuals.

The above facts indicate also the true explanation of certain
exceptional cases, which have somotimes been observed, in which
fertility exists without menstruation. Various authors (Churchill,
Keid, Velpeau,&c.) have related instancesof fruitful women in wbom
the menses were very scanty and irregular, or even entirely abaeoL
Tbe menstrual flow is, in fact^ only the external sign and acoompfl>
nimeni of a more important process taking place witbin. It is
habitually scanty id some individuals, and abundant in others.

HSNSTBUATIOK. 659

Such variations depend upon the conditioQ of vascalar activttj of
the system at Urge, or of the uteri oe orgBQS in particular; and
thoagh the bloody discharge is usually an index of the general
aptitude of these organs for successful impregnation, it is not an
absolute or necessary requisite. Provided a mature egg be dis-
charged from the ovary at the appointed period, menstruation pro-
perly speaking exists, and pregnancy is possible.

The blood which eiscapes during the menstrual flow is supplied
by the uterine mucous membrane. If the cavity of the uterus be
examiued after death during menstruation, its internal surface is
seen to be smeared with a tbickish bloody fluid, w^iich may be
traced through the uterine cervix and into the vagina. The Fallo-
pian tubes themselves are sometimes found excessively congested,
and filled with a similar bloody discharge. The menstrual blood
has also been seen to exude from the uterine orifice in cases of pro-
cidentia uteri, as well as in the natural condition by examination
with the vaginal speculum. It is discharged by a kind of capillary
hemorrhage, similar to that which takes place from the lungs in
cases of hemoptysis, only less sudden and violent The blood does
not form any visible coagulum, owing to its being gradually exuded
from many minute points, and mingled with a large quantity of
mucus. When poured out, however, more rapidly or in larger
quantity than usual, as in cases of menorrhagia, the menstrual blood
coagulates in the same manner as if derived from any other source.
The hemorrhage which supplies it comes from the whole extent of
the mucous membrane of the body of the uterus, and is, at the same
time, the consequence and the natural termination of the periodical
congestion of the parts.

G60

MiENSTRCATION AND PBBOHAKOr.

CHAPTER VI.

OK THE COnPCS LTTTEITM OP MENSTRUATION AN'D

PREONANCY.

Aft£k thti rupture of the Grnaflan vesicle at the menstrual
period, a bloody cavity is left in tlie ovary which ia Bubsequenily
obliteriUeiJ by a kind of gronulating process, somewhot similar in
character to the healing of &n abscess. For the GraaHan vesicle
is intended nimply for the formation and growth of the egg.
AficT the egg therefore has arrived at maturity and has been dig.
charged, the Graafian follicle has no longer any function to per-
form. It then only remains for it to pass through a proces of
obliteration and atrophy, as an organ which has beoomo useloas
and obsolete. While undergoing this process, the Graaiinn vesicle
is at one time converted into n peculiar, solid, globular body, which
is called iheeorjmt luteum; a name given to it on account of the
yeliow color which it acquires at a certain period of its formation.

We shall proceed to describe the corpus luteum in the human
species; firit, as it follows the ordinary oourae of development
after menstruation ; aud secondly, as it is modified in its growth
and appearance during the existeuce of pregnancy.

I. CORPUS LUTEUM OF MENSTRUATION.

We have already described, in the preceding chapter, the man-
ner in which a Uraatian ventcle, at each menstrual epoch, swells,
protrudes from the surface of the ovary, and at last ruptures and
discharges its egg. At the tnonieiit of rupture, or immediately
iifler it, an abundant hemorrhage takes place in the human sub-
ject from the vessels of the follicle, by which its cavity is filled
with blood. This blood coagulates soon after its exudation, as
it would do if oxtravasatcd in any other part of the bo<ly, and
the ooagulum is retained in the interior of the Gma6an folliclo.
The opening by which the egg makes its escape is usually not aa

CORPUS LUTBUU UF HBNBTBpATION.

561

Fig. 187.

QmAJiTi AH FoLiic li
ree«ntlj raptured during
mcntlrnmtloii, and fllled
wtili a blondf coAfnIom ;
•bown ta. loBfliadlDal lec-
Uau —a. Tliiiaa of the
aT»rf. b, Hembninaof (ba
TMlele. e, Potatof rvptUN.

extensive laceration, bat a mioate rounded perforation, oflan not
more than half a line in diameter. A small probe, introduced
througb tbia opening, passes directly into the
cavity of the follicle. If the Qraa6an follicle
be opened at this time by a longitudinal inci-
sion (Fig. 187), it will be seen to form a globu-
lar cavity, one-half to three-quarters of an
inch in diameter, containing a soft, recent,
dark-colored coagulam. This coagulum has
no organic connection with the walls of the
follicle, but lies loose in its cavity and may be
easily turned out with the handle of a knife.
There is sometimee a slight mechanical adhe-
sion of the clot to the edges of the lacerated
opening, just as the coagulum in a recently
ligatared artery is entangled by the divided
edges of the internal and middle coats ; but
there is no continuity of substance between
them, and the clot may be everywhere readily
sspareted by careful manipulation. The membrane of the vesicle
presents at this time a smooth, transparent, and vaacnlar internal
sarfaee, without any alteration of color, consistency, or texture.

■ An important change, however, soon begins to take place, both
ill the central coagulum and in the membrane of the vesicle.

The clot, which is at first large, sofl, and gelatinous, like any
other mass of coagnlated blood, begins to contract; and the serum
separates from the coagulum proper. The serum, as fast as it
separates from the coagulum, is absorbed by the neighboring parts;
and the clot, accordingly, grows every day smaller and denser than
before. At the same time the coloring matter of the blood under-
goes the changes which usually take place in it after extravasation,
and is partially reabsorbed together with the serum. This second
change is somewhat less rapid than the former, but still a diminu-
tion of color is very perceptible in the clot, at the expiration of
two weeks.

The membrane of the vesicle daring this time is beginning to
undergo a process of hypertrophy or development, by which it
becomes thickened and convoluted, and tends partially to fill up
the cavity of the follicle. This hypertrophy and convolution of
the membrane just named commences and proceeds most rapidly
8«

662

MBITSTRlTATtON AWD PRBOSASCT.

Fig. 168.

at the deeper part of the follicle, directly opposite the situation of
ilie superliuial rupture, from tliia point the meitibrane grailually
becomes thinner nnd leas convohitcd as it approaches the surface
of the ovary and the edges of the ruptured orifice. |

At the end of three weeks, this hypertrophy of the membrane of
the vesicle has reached its maxirnum. The rupturtxl Granfinn fol-
licle fads now liecorne so completely solidiiied by the new growth
above described, and by ilie conden-aation of its clot, that it receive*
the name of the corpus luieum. It forms a perceptible proininence
on the surfiice of the ovury, and may be felt between the Sngera
as a well-dellned rounded tumor, which i^ nearly always Mimewhat
naituiicd from side to side. It measures ab<:iut three-quarters of bd

inch in length and half an inch in
depth. On iu surface may be seeoft
minute cicatrix of the peritoneum,
occupying the spot of the original
rupture.

Oil cutting it open at this time (Fig.
188), the corpus lutcum is seen to con-
ai.ti, as above described, of a central
congnlum and a convoluted wall.
The coagulum is semi-transparent, of
a gray or light greenish color, more
or less mottled with red. The con-
voluted wall is about onc-cighth of
an inch thick at its dec|wsl part, and
of an indefinite yellowish or roej
hue, not very difit-rent in tinge from
the rest of the ovarian tisaue. The convoluted wall and the con-
tained clot lie simply in contact with each other, as at first, witfaoat
any intervening membrane or other organic connection ; and ibey
may still be readily separated from each other by the handle of a
knife or the flattened end of a probe. The corpus luteum at this
time may also be stripped out, or cnaclcnted entire, from the ovariaa
tissue, just as might have been done with the Graafian follicle pre-
viously to its rupture. When enucleated in this way, thtj corpus
lateum presents itself under the form of a solid globular or Oat-
louod tumor, with convolutions upon it .somewhat similar in ap-
ranee to those of the brain, and covered with the reuiains of
eolar liasue, by which it was previously connected with th«
mce of the ovary.

ri v < K 1 <'Tlt npcn. ■huirlirii V'ltpm
IlllrDiD illrl.lnl iDUslluitloalt)' ; Ibif*
v«.ot(* ftfi^r lufliiiiiiiHtioii. Frum & giji
dM4 ct UvinvpET'i*.

CORPUS LUTtCX OF ICKKSTRCATIOS.

563

After the third week from the close of

the

PiK. 16S.

^^v . j:

At 4 ft T , ■liiivlni pi^rpDa
•trnkiloa: IVou a ■oinaD AraA

wecK rrom tne close oi menstruation, the corpus
luleutn passes into a retrograde cont]ition. It diminishes percep-
tibly in size, and the central coagulum continues to be absorbed
and loses still further its coloring matter. The whole bodj under-
goes a process of partial atrophy ; and at
the end of the fourth week it is not more
than three-eighths of an ioch in its longest
diameter. (Fig. ISH.) The external ciciitrix
may still usually be seen, as well as the
point where the central coagulum cornea
in contact with the peritoneum. There ta
still DO organic connection between the
central coagulum and the convoluted wall;
but the partial con d ansa tioQ of the clot and
the continued foklingof the wall prevent the
separation of the two being so easily accom-
plished as before, though it may still be
effected by careful management. The entire
corpus luteum may also still be extracted "'•("pi"!-
from its bed in the ovarian tissue.

The color of the convulutoi] wall, during the early part of this
retrograde stage, instead of fading, like that of the fibrinous coagu-
lum, becomes more strongly marked. From having a dull yellowish
or rosy hue, as at Grst, it gradually assumes a brighter and more
decided yellow. This change of color in the convoluted wall is
produced in consequence of a kind at fatty dcgciicracion which
takes place in its texture; a large quantity of oil-globules being
deposited in it at this time, as may be readily recogni/.ed uader
the microtion|>o. At the end of the fourth
week, this alteration in hue is complete;
and the outer wall of the corpus luteum
is then of a clear chrome-yullnw color, by
which it is readily distinguished from all
the neighboring tiHsucs.

After this period, the procewi of atrophy
and degeneration goes on rapidly. The
clot becomes constantly more dense and
shrivelled, and is iioon converteil into a

minut«, stellate, white, or reddish white p,.„. .„,,,„ ,„p„. ,,.
cicatrix. The vellow wall hecumes snfier f"™. cm* w^LaftpfBrno-nn..
and more frmble, as is the case with all ^i^ ui-uIliki..

Fig. 19(L

564

XKKSTBaATION AND TKZOyAKCT,

tissues undergoJDg fatty degeneration, and bIiows leu distinctly
the marking of its coDVolutions. At the s&mo time, its surfaces
become cotirounded with the central coagulum on the one hand,
and the neighboring tissues on the other, so that it is no longer
possible to separate them fairlj? from each other. At the end orl
eight or nine weeks the whole body is reduced to the ootidilion of
an iiistgnincant, yellowish, ctcatrix-liko 8i>ot, measuring less than a
qunrier of an inch in its longest diameter, in which the original
texture of the corpus luteum can be recognised only by the pecu-
liar folding and ci>Loring of its constituent partts. Subsequently its
atrophy goes on in a leas active manner, and a period of seveo or
eight months sometimes elapses before iti Snal and complete dis<
appearance.

The corpus luteum, accordingly, is a formation which results
from the filling up and obliteration of a ruptured Graafian follicle.
Under ordinary conditions, a corpus luteum is produced at every
menstrual period; and notwithstanding the rapidity with which it ■
retrogrades and becomes atrophied, a now one is always formed
before its predecessor has completely disappeared.

When, therefore, we examine the ovaries of a healthy female, in
whom the menses have recurred with regularity for some time
previous to death, several corpora lutea will be met with id different
stages of formation and atrophy. Thus we have found, under aucb
oircumstancoa, four, five, six, and even eight corpora lutea in the
ovaries at the same time, perfectly difttinguisbable by their texture,
but very small, and most of tliem evidently in a state of advanced
retn>gre88ion. They finally disapiMsor altogether, and the number
of those present in the ovary, therefore, no longer corresironda with
that of the Graafian follicles which have beeii ruptured.

II. CORPUS LUTEUM OF PREGXAyCY.

Since the process above described takes place at every menstrual
period, it is independent of impregnation and even of sexual iuter-
course. The mere presence of a corpus luteum, therefore, is no
indication that pregnancy has existed, but only that a GraaBan
follicle has been ruptured, and its contents discharged. We 6nd,
nevertheless, that when pregnancy takes place, the appearance of
the corpus luteum becomes so much altered as to be readily dis-
tinguished from that which simply follows the ordinary menstrual

CORPUS LUTBUK OF PBBOKAKCT. 565

procesB. It ia proper, therefore, to speak of two kinds of corpora
lotea; one belonging to menstraation, the other to pregnancy.

The difference between these two kinds of corpora latea is not
an essential or fundamental difference; since they both originate in
the same iray, and are composed of the same strnctares. It is,
properly speaking, only a difference in the degree and rapidity of
their developmenL For while the corpus luteum of menstruation
passes rapidly through its different stages, and is very soon reduced
to a condition of atrophy, that of pregnancy continues its develop-
ment for a long time, attains a larger size and firmer organization,
and disappears finally only at a much later period.

This variation in the development and history of the corpus
lateam depends upon the unusualfy active condition of the pregnant
nterns. This organ exerts a powerful sympathetic action, during
pregnancy, upon many other parts of the system. The stomach
becomes irritable, the appetite is capricious, and even the mental
faculties and the moral disposition are frequently more or less
affected. The ovaries, however, feel the disturbing influence of
gestation more certainly and decidedly than the other organs, since
they are more closely connected with the uterus in the ordinary
performance of their function. The moment that pregnancy takes
place, the process of menstruation is arrested. No more eggs come
to matarity, and no more Graafian follicles are ruptured, during the
whole period of gestation. It is not at all singular, therefore, that
the growth of the corpus luteum should also be modified, by an
influence which affects so profoundly the system at large, as well
88 the ovaries in particular.

During the first three weeks of its formation, the growth of the
corpus latenm is the same, in the impregnated, as in the unimpreg-
Dated condition. After that time, however, a difference becomes
manifest Instead of commencing a retrograde course during the
fourth week, the corpus luteum of pregnancy continues its deve-
lopment. The external wall grows thicker, and its convolutions
more abundant. Its color alters in the same way as previously
described, and becomes a bright yellow by the deposit of fatty
matter in microscopic globules and granules.

By the end of the second month, the whole corpus luteum has
increased in size to such an extent as to measure seven-eighths of
an inch in length by half an inch in depth. (Fig. 191.) The central
coagnlum has by this time become almost entirely decolorized, so as

566

MKSSTRUATION AND PBKOSANCT.

&>»

vt.

,.^-

kV,-,1

to present the appearance of a purely fibrinouii deposit Sometimes
we find that a part of the serum, during its separation from the clot,
lias nccumulated in tbe centre or the mass, m in Kig.li)!, funninga
little cavity containing a Tew drop<< of clear fluid and inclosed by a
wbitisli, fibrinous layer, tbe remains of the solid portion of tbe clot.

It is this fibrinous layer
^'*- ^**- which has sometimes been

mistaken for a distinct or-
ganized membrane, lining
the internal sarrace of the
convoluted wall, and which
has thus led to the belief
that the yellow matter of the
corpus luteum 19 normally
deposited outside the mem-
brane of the (Jraafian fol-
licle. Such, however, is nut
its real stracture. The convuluted wall of the corpus Ittteum i* the
membrane of the follicle itself, partially altered by hypertrophy,
ns may be readily seen by exaniination in the earlier stages of its
growth; and the llbrinous layer, situale<l internally, is the original
bloody congulum, decolorized and condensed by continQod absorp-
tion. The existence of a central cavity, containing serous 6uid, is
merely an occasional, not a con.^tant phenomenon. More frequently,
the fibrinous clot is solid throughout, the serum being gradually
absorbeil, aa it separates spontaneously from the C'OaguItun.

During the third and fourth

C*XPCI Lor«t:« at pNgnkaef, al and of Mcond
■«nih ; frua » wmiaa d«*d rrnm isdoMd atwrilua.

Pig. 193.

■':•--

v.v'

Cniftt* I.rTiuM el prni^Riirf. *t«Bdcf foDrtb
(ftvUll ; rrum k iruuitD dr*i Ijr polioji.

months, the enlargement of th«
corpus luteum continues; so
that at the end of that time it
may measure seven-eighths of
an inch in length by three-
quartera of an inch tn depth.
(Fig. 192) The convoluted
wall is still thicker and more
highly developed than before,
bnving a thickness, at its deep-
est pnrt, of three-sixtaenihs of
an inch. Its color, however, haa
already begun to fade, and is

COBPL'3 LL'TEL'U Of FRKGNAIVCT.

687

t'ig. 193.

now of a doll yeUow, insteaii of th« bright, clenr tinge which it
previou<iIy exhibited. The central coagulum, perfeutly colorless
and tibriiiuus in appearance, ia often so much flattened out, by tliu
lateral comprcssioa or its tnaas, that it bos hardly a line in thick-
neaa. The other relations of LhctliflTercnt partsof the corpus luteum
reraain the same.

The corpus luteum has now attained its maximum of develop-
ment, and remains without aiiv vury perceptible alteration during
the fifth and sixth months. It then begins to retrograde, diminish-
ing constantly in sitw during ihe seventh and eighth months, lu
external wait fades still more perceptibly in color, becoming of a
foitit yelluwihh white, Qot unlike that which it presented ai the und
of the third week. Its texture is thick, soft, and elastic, and it is
still strongly convoluted. An abundance of fine re<] vessels can be
seen penetrating from the exterior into the interstices of \tn convo-
lotions. The central coagulam is reduced by this time to the coq-
ditioa of a whitish, radiated cicatrix.

The atrophy of the organ eoniinuca during the ninth month.
At the termination of pregnancy, it is re-
duced to the size of half an inch in length
and three-eighths of an inch in depth.
(Fig. IttS.) It is then of a faint indefinite
hue, but little oontraated with the remain-
ing tissues of the ovary. The central cica-
trix has become very small, and appears
only as a thin whitish lamina, with radiating
procesaes which run in between the intcr-
stioefl of the convolutions. The whole mnss,
however, is still quite Qrm and re.'iisting to
tbe touch, and ia readily distinguishable,
both from its size and texture, aa a pro-
minent feature in the ovarian tissue, and a
reliable indication of pregnancy. The con-
voluted structure of its external wiill is
very perceptible, and the point of rupture,
with its external peritoneal cicatrix, distinctly visible.

Afler delivery, tbe corpus luteum retrogrades rapidly. At the
end of eight or nine weeks, it has become tfo much altered that its
color is uo longer distinguishable, and i>nly faint traces of its con-
voluted structure are to be discovered by close examination. These

CLimrra Lvttpn at ^rrgm
•>acf, ai l*f Bi : from ■ winnaa
dMii In 4l«lt«*ry frain topiure

o( tk* nieru*.

MINSTRCATIO!! A5» rUtGSAVCT.

trncoA may remain, however, for a long time al^erwarJ, more ur leas
coneenled io the ovarian tissue. We have distinguished them bo
late as nine and a half mt>ntha nfter delivery. They finally disap-
pear entirely, together with the external cicatrix which previously
marked their situation.

During the existence of gestation, the procesa oF menstruation
being suspended, no nev follicles arc ruptured, and no new corpora
lutea produced ; and as the old ones, formed before the period of
conception, gradually fade and disappear, the corpus luteum which
marks the occurrence of pregnancy afler a short time cxista alooo
in the ovary, and is not accompanied by any others of older dale.
In twin pregnancies, we of course And two corpora lutea in the
ovaries; but these are precisely similar to each other, and, being
evidently of the same date, will not give rise to any confiuioo.
Where there is but a single fwtus in the uterus, and the ovaries
contain two corpora lutea of similar appearance, one of them
belongs to an embryo which has been blighted by some accident
in the early part of pregnancy. The remains of the blightt-d om-
bryo may of\en be ditjcovcred, in such cases, in some part of the
Fallopian tubes, where it has been arrested in its descent toward
the uterus. ■

Afler the process of lactation comes to an end, the ovaries again ^
resume their ordinary function. The Qraafiao follicles mature and
rupture in succession, aa before, and new corpora lutea follow each fl
other in alternate development and disappearance. ^

We find, then, that the corpus luteum of menstruation diflers from
that of pregnancy in the extent of its development and the dura*
tion of ltd oxistcnoe. While the former passes through all the im-
portant phases of its growth and decline in the period of two ,
months, the latt«r lasts from nine to ten months, and presents, H
during a great portion of the time, a larger size and a more sohd ~
organization. It will be observed that, even with the corpus
luteum of pregnancy, the bright yellow color, which is so import-
ant a characteristic, is only temporary in its duration; not making
its appearance till about the end of the fourth week, and again ^
disappearing af\er the sixth month. H

The following table contains, in a brief form, the characters of
the oorpns luteum, as belonging to the two different conditions of
menstruation and pregnancy, corresponding with difiereni periods
of its development.

COBPUB LUTKDX OF PBEQKANCT.

569

At At nd of
Arte weekM
Ont nuMtk

Six motttka

Nine wumAM

Coarun Ldtsdh of Ifuin-Bv^Tiox, CoBPits LmnrM or Pbbokakct.

Thne-qa&rtcn of an incli Id di&meter; oentntl elot reddlBh; eoQ-
Tolatod wall pal«.

Smaller; oonroloted wall bright
jrellow ; clot still reddish.

B«daced to the condition of an
Inalgnlllcant cicatrix.

Absent.

Larger; conrolated wall bright
jrellow ; clot still reddish.

SeTon-elgbths of an inch in dia-
meter ; convolated wall bright
jellow ; clot perfeotlj decolor-
ised.

Still as large as at end of aeeond
mooth; clot Abrinooi; ooqto-
Inted wall paler.

On^Ualf an inch in diameter;
central clot converted Into a
radiating cicatrix; the external
wall tolerablj thick and oodto-
Inted, bnt withoat an; bright
7«Uow color.

670

DErELOPUKNT OF THB ISTPREGyATBO EGO.

CHAPTER VII.

ON TIIK PFVKLOPMKN'TOFTHE IMPREOXATED EGG—

SKG MENTATION 0 F TH p: VITE LI.U3-BLA.?T0I>RltM 10
MEMBBANE-FORMATION OF ORGANS IX THE FROG.

We have seen, in the foregoing cliaptors, how the b^, produced
in the ovarian follfcle, becomes gradually developed and ripened,
until it is ready to be discharged. The egg, accordingly, paaiM
through several successive stages of formation, oven while still con-
tained within the ovary; and its viiellua hecomea gradually com-
picteil, hy the formalion of albuminous material and the deposit of
molecular granulations. The laal change which the egg undergoes
in this siiuuiiuii, and which timrks its complete maturity, is the dts-
appearunco of the germinntive vesicle. This vehicle, which ia, in
general, a prominent feature of the ovarian egg, disappears but a
short lime previous to its discharge, or even just at the period of
its leaving the Oraa^an f<jllicle.

The eg-,', therefore, consisting simply of the mature vitellus and
the vitelline membrane, comes in contact, after leaving the ovary,
and while passing through the Fallopian tube, with the S[Krmatie
fluid, and thereby becomes fecundated. By the influence of fecun*
datioTi, & new stimulus ia imparted to its growth; and while the
vitality of the unimpritgnated germ, arrived at this point, would
have reached iui termiimtion, the fwundatud egg, ou the contrary,
starts upon a new and more extensive course of development, by
which it is 6nally converted into the body of the young animal.

The egg, in the first place, a^ it passes dowu tbu Fallopian tube,
becomes covered with an albuminous secretion. In the birds, ajs we
have seen, this secretion is very abundant, and is (icpo.-«ited in sue*
cessive layers around the vtlellus, In the reptiles, it ia also poured
out in considerable quantity, and serves for the nourishment uf tbe
egg during itaenrly growth. In quadrupeds, the albuminous matter
is supplied in the same way, though in smaller quantity, by the

■■Oiri5TAT10N OP THE VITELLUS.

571

PlK.lll*.

mucous membrane of tho Fallopian tube^ and envelopes the egg

in a layer of notritioua material.

A verj remarkable change now takes place in the impregnated egg,
which ia known aa the mpontaneous division, or aegmmtation, of the
vitellu^. A furrow first shows itself,
running rouDdtheglubularmassoflhe
vitcllaa in a vertical direction, which
gradually deepens until it has divided
the viteltus into two separate halves or
hemispheres. (Fig. 1C4, n.) Almo^l at
the same time another furrow, running
.It right angles with the fin-^t, penetrates
also the substance of the vitellua and
cuts it in ft transverse direction. The
vitellus isthuadividwl into fourcqual
portions (Fig. 104, b), the edges and
angles of which are rounded off, and
which are still oontained in the cavity
ofthe vitelline membrane. Thespaccs
between them and the internal snrface
of the vitulline membrane are occu-
pied by a transparent fluid.

Tho proi-BM thus commenced goes
on by a successive formation of fur-
rows and sections, in various direc-
tions. The four vitelline segments
already produced are thus subdlTided
into sixteen, the sixteen into sixty-
four, and so on ; until the H'hole vi-
lellus is converted into a mulberry
shaped mass, composed of minute.
Dearly spherical bodies, whit-h are
called the "vitelline spheres." (Fig.
194, c.) These vitelline spheres have
a somewhat firmer consiKtency than
the original substAnce of the vitellus;
and this consistency appears to in-
crease, as they succewively multiply
m numbers and diminish in size. At last they have become so
abundant as to be clueeiy crowded tt>gether, compressed into poly-
gonal forms, and flattened against the internal surface of the vltel-

SluaiMAtlCR l<r TDK VlTILl. l-«.

572

DEVELOPMENT OP THE IMPREQNATBD BOO.

line membrane, (t'tg. 194, d.) They have by ibis lime been con-
vurteJ into true animal cells; and iticse celts, adhering to each other
by their adjacent edges, form a ccttitinuous organised membraiie,
which is termed the Blaatodfrmic membrane.

Daring the formation of this membrane, moreover, ibe egg, wbile
patufing through the Fallupinn tubes into the uterus, lias increased
ID size. The albuminous matter with which it was eoveloped has
liquefied ; and, being absorbed by endosmosis tbroogb the viielline
membrane, has furnished the materials for the more aolid and ex-
tensive growth of the newly-formed slructurea. It may also be
seen that a large quantity of this 6uid has accumulateU io the
central cavity of the egg, inclosed accordingly by the blastodermic
membrane, with the original vitelline membrane still forming aa
external envelope round the whole.

The next change which takes place consists in the division or
splitting of the blastodermic tnombrane into two layers, which are
known as the external and irUemal layerso/the blastodermic membrane.
They are both still composed exclusively of cells; hot those of tlie
external layer are usually smaller and more compact, while ihoae
of the internal are rather larger and looser in texture. The egg
then presents the appearance of a glubular sac, the walls of which
consist of three concentric layer?, lying in contact with and inclos-
ing each other, viz., Ist, the structureless vitelline membrane on the
outside; 2d, the external layer of the blastodermic membrane, oom>
posed of oelU ; and 3d, the internal layer of the blaalodcrniic mem-
brane, also composed of cells. The cavity of the egg is occupied
by a transparent fluid, ss above mentioned.

Tliis entire process of the segmentation of the vitellus and the
formation of the blastodurmiu meinbnine is one of the roost re-
markable and important of all the changes which take place during
U9 development of the egg. It is by this process that the simple
lobular mass of the vitollus, composed of an albuminous matter
and oily granules, is converted into aa organized structure. F<v
the blB&to<lermic membrane, though consisting only of cells nearly
uniform in size and shape, is nevertheless a truly organised mem-
brane, made up of folly formed anatomical elements. It is, more-
over, the first sign of distinct organization which makes its appear-
ance in the egg; and as soon as it is completed, the body of the
new fcctus is formed. The blaetudermic membr&ne is, in fact, the
body of the fuetus. It is at this time, it is true, exceedingly simple
in texture; but wo shali sec hereafter that all the future organs

BLASTODBRUIC MEMBRANE. 57S

of the body, however varied and complicated id stracture, arise out
of it, by modification and development of its different parts.

The segmentation of tbe vitellus, moreover, and the formation
of the blastodermic membrane, take place in essentially the same
manner in all classes of animals. It is always in this way that
the ^g commenoes its development, whether it be destined to
form afterward a fish or a reptile, a bird, a qoadrnped or a nun.
The peenliarities belonging to different species show themselves
afterward, by variations in the manner and extent of the develop-
ment of dififerent parts. In the higher animals and in the human
subject the development of the egg becomes an exceedingly com-
plicated process, owing to the formation of varioas accessory
oi^ns, which are made requisite by the peculiar conditions under
which the development of the embryo tajces place. It is, in fact,
impossible to describe or understand properly the complex embry-
ology of the qnadmpeds, and more particularly that of tbe human
snbject, without first tracing the development of those species in
which the process is more simple. We shall commence our descrip-
tion, therefore, with the development of the egg of the frog, which
is for many reasons particularly appropriate for our purpose.

The egg of the frog, when dischai^ed from the body of the female
and fecundated by the spermatic fiuid of the male, is deposited in
the water, enveloped in a soft elastic cushion of albuminous sub-
stance. It is therefore in a situation where it is freely exposed to
the light, the air, and the moderate warmth of the sun's rays, and
where it can absorb directly an abundance of moisture and appro-
priate nutritious material. We find accordingly that under these
circumstances tbe development of the egg is distinguished by a
character of great simplicity ; since the whole of the vitellus is
direetly conferted into the body of the embryo. There are no acces-
Bory organs required, and consequently no complication of tbe
formative process.

The two layers of tbe blastodermic membrane, above described,
represent together the commencement of all tbe organs of the foetus.
They are intended, however, for the production of two different
systems; and the entire process of their development may be ex-
pressed as follows: The external layer of the blastodermic membrane
produces the spinal column and all the organs of animal life; while the
intemal layer produces the intestinal canal, and all the organs if vege-
tative life.

The first sign of advancing organization in the external layer of

574

nBTEr.0PME?rT

[XPRSQNATKn EGG.

Vig. 195.

J 11 !■ ]i I... • *i r r< fcp.'i. isHh etiio-
nt'oci'iiifut u( Ivrinfc;l»ii of cmbry*:

the biftstodermic membrane shows itself in a tbickening and coo-
d(;n»attor] of its slructure. This thickened [lorttoa baa the form of an
elongated oval shaped spot, termed the "enibryonie spot" (Fig. 19-5),

the wide edgea of which are somewhat
more opaque than the reni of the blaato-
dermic loeiubnine. locloecd witbin
these opaque edges is a narrower color-
less and transparent spaca, the "area
pelluuidii," and in its centre is a delicate
line, or furrow, running longitndinalty
from front to rear, which ia called the
"primitive trace."

On each side of the primitive trace,
in the area pellucida, the aubttanoeoT
the blastodermic membnine rises up in
such a manner as to form two nearly
parallel vertical plates or ridges, which
approach each other over the dorsal aspect of the foetus and are
iherefure called the "dorsal plates." They at last meet on the
median line, so as to inclose the furrow above described and con-
vert it into a canal. This afterward becomes the spinal canal, and
in its cavity is formed the spinal cord, by a de[K>sit of nervoas
mniter upon its internal surface. At the anterior extremity of this
canal, its cavity is large and rounded, to aocommodate the braia
and medulla oblongata; at its posterior extremity it is narrow and
pointed, and contains the extremity of the apinal cord.

In a transverse section of the egg at this stage (Pig. 196% the
dorsal plates may be seen approaching each other above, on each
side of the primitive furrow or "trace." At a more advanced
period (Fig. 197) they may be seen fairly united with each other,
BO as to inclose the cavity of the spinal canal. At the same time,
the edges of the thickened portion of the blastodermic membrane
grow outward and downward, so as to spread out more and inon?
over the lateral portions of the vitelline tnass. These are called
the "abdominal plates;" and as they increase in extent they lend
to unite with each other btdow and inclose the abdominal cavity,
just as the dorsal plates unite above, and inclose the spinal canal.
At last the abdominal plates actually do unite with each other on
the median line (at i, Fig. 1H7), embracing of course the whole
iuteriial layer of the blastudermio membrane {»), which incloses in

TORMATIOX OT OROAyS.

itfi turn tlic remains of the original vittjltus anil the albuminoiu
fluid wbtcb has accumulated in its cavity.

Pig. 196.

Pig. 1!>7.

Tnoir^nn MClInn of Eon }a *» mdjr
■ti^p at <li>*»)r>pDH«|._1. Kuli'tnal Ujcf

Iila<i» It. tntnrKil laj«T of tiUilirffrmlt
uemt-mi«.

1 ■ P ■ K.- !> J t ( u Rii ■>, ■! ■ ••>inKB-k<s|

|>r>lDI of nnl-.n boitfpoa ■bJ^tmluH! |>lAi'kft-
3. 1 Di'r*!'! plain antlrd wtili *aeh nth^r
i>n Ihr mrdUp llacKDj laclmlof I ha* pin al
ranal A. A AlulniHiiiiil pUli-a. 4 trr-
tlou or iflnal culnroEi. wlih Ikin1n» and
rll-a fi. Inlvrnil Ujror vf bUMiKlorula
urnibnu*.

Daring this lime, there is formeil, in the tliiuknessof the external
blastodermic layer, immediately beneath the spinni canni, a longitu-
..dinal cartilaginous cord, culled the "chorda dorsalis." Around the
'chorda dorsalifl arc afterword developed the bodies of the vertulirw
(Fig. ItfT, 4), forming the chain of the vertebral column : and the
oblique proccMes of the vcrtebrir run upward from this point into
the dorsal plates; while the transverse processes, and rib«, run o^^
ward and downward in the abdominal plates, to encircle more or
less completely the corr.esponding portion of the Uxly.

If wc now examine ibo egg in longitudinal acciion, white this
process is going on, the thickened portion of the external blasto-
dermic layer may be seen in profile, as at i, Fig. 198. The anterior
portion (u), which will form the bead, is thicker than the posterior
(i), which will form the tail of the young animal. Ai^ the whulo
maM grows rapiilly, both in the anterior and the posterior dircc>
tion, the head becomes very thick n tid voluminous, while the tail also
begins to project backward, nnd the whole egg assumes a distinctly
elongated form. (Fig. 199.) The abdominal plates at the same time
meet upon its under surface, and the point at which they tinally

676

DBVBLOPHBNT OF THK IVPBBGI7ATED EOO.

uiiit4 forms tlie utKlorninal cicatrix or wnbHicm. The internal lilas-
todertnic layer is seen, of oaurso, in tlie longitudinal section of ilie

Pig. \m.

Jig. \9».

Bna or moiti !■ pi*CM»4r 4av«te
Mat.

DURTkic of Pk<'iii'« K<tn, Ib an mfIT

■tags of drtaluptnaui ; loail luminal ••«-
llu*. — I. TlilrkFOfl p-irlUin of •xlvrsal
bljui(sd«riatc Imy^f, rinnlDibod/uf ftilM.
S Inlcriiir FKlrooiltjr of rutin*. 3. Pudn-
^•■reKlmiillr. 4 IntoniKl l«j«r of l>lu-
ludvmlcmriiibrvno. n. C>*l]]r «f tIi<Ui)«.

egg, &s well as in the transverse, embraced by the abiloniinal platei,
and inclosing, as before, the rdrnalns of the vitullutt.

As the development of the above parta goes on (Fig. 200), the
head becomes still larger, and soon shows traces of the formation

Kg. 200.

Bita «r Paoii. rwnlterulraMnl.

of organs of special Dense, The tail also iDcrcascs in size, and pro-
jects farther from the posterior extremity of the embryo. The
spinal cord runs in a longitudinal direction from front to rear, and
its anterior extremity enlarges, so as to form the brain and medulla
oblongata. In the mean time, the internal blastodermic layer, which
is Bubsequemly to be converted into the intestinal eanal, has been
shut in by the abdominal walls, and still forms a perfectly clotted
880, of a slightly elongated figure, without either inlet or outlet.
ADicrward, the mouth is formed by a process of atrophy and perfo-
ration, which takes place through both external and internal layers,
at iho anterior extremity, while a similar perforation, at the poste-
rior extremity, results in the formuliou of the anus.

roBSATios Of ORaA?rs.

577

All these parts, liowover, ar« as yet imperfect; and, being nioreljr
in the course of formation, are incapable of performiDg any active
t'u notion.

By a continuation of the aame procesa, the different portiona of
the external blastoderinio laj'er are further (levelopwd, so as to re-
sult in the complete formation or the various parts of the skeleton,
the integument, the organs of special aenae, and the voluntary
nerves and muwlee. The tail at the same time acquires sufficient
size and strenj^lb to b« capable of acting as an organ of locomo-
tion. (Fig. 201.) The intestinal cannl, which hna been formed from

Pig. 201.

-^^t(S^

7 kUffit: full)' il»>*l»poi.

the internal blastodeniiic Iuy«r, i« at Drat a short, wide, and nearly
straight tube, running directly from the mouth to the anus. It
soon, however, begins tu grow faster than the nbdominal cavity
which incloses it, becoming longer and narrower, and is at the
same time thrown into nnmerous convolutions. It thus presents a
larger internal surface for the performance of the digestive process.

Arrived at this period, the young tadpole ruptures the vitelline
membrane, by which he ban heretofore been inclosed, and leaves the
cavity of the egg. He at first fastens himself upon the remains of
tbe albuminous matter deposited round the egg, and feeds upon it fur
a short period. Be soon, however, acquires sufficient strength and
activity to swim about freely in search of other food, propelling
himself by means of his large, membraiiuuB, and muaculur tail.
Tbe alimentary canal increaiies very rapidly in length and becomes
spirally coiled up in the abdominal cavity, »o as to attain a length
from seven to eight time.*! greater tbun that uf the entire body.

After a time, a change lakta place in the external form of the
young animal. The posterior exiremiives or limbs begin to show
themselves, by budding or sprouting from tbe aides of the body^
Just ut the base of the tail. (Fig. 202.) The anterior extruiniiius also
grow at this time, but are ai first conccHled underneath the integu-
ment. 1'bey afterward, however, become liberated, and show them*
37

078 IiEVKI-OPMBXT OP THE IMPRroVATBD EOO.

selves externally. Ai 6rst botli tlie fore and hind legs are very
smalt, imperfect in structure, and altogether uselcsa for purposes of
locomotion. They soon, however, increase in size and 8tr«ogth;
and while they keep pace with the increatiing development of the
whole body, the uil on the contrary ceases to grow, and beeoims
shrivelled and atrophied. The limbs, in fact, are destined finally
to replace the t:iil as organs of locomotion ; and a time at lost
arrives (t'lg. 203) when the tail has altogether disappeared, while

Rg. 202.

Fig. 203.

^'*>G

TAi>rs|,K,imii Un'bilit(tDBlti|iok«rariDtd.

Vmttres Tkcu.

the legs have become fully developed, muscular and powert
Then the animal, which was before coofined to an aquatic mode
of life, becomes capable of living also upon land, and a trans-
forniaiion is thus eflFected from the tadpole into the perfect frog.

During the same time, other changes of an equally important
character have taken place in the internal organs. The tadpole at
first breathes by gills; but these organs Bubeequently become
atrophied and di-sappear, being finally replaced by well developed
lungs*. The structure of the mouth, also, of the integument, and
of the ciruulatory tsysiem, is altered to correspond with the varying
conditions and wants of the growing animal; and all these changes,
taking place in part successively and in part simultaneously,
bring the animal at last to a slate of complete formation.

The process of development may then be briefly recapitalaled &s
follows :—

1. The blastodermic membrane, produced by the segnientation
of the vitelluB, consists of two cellular layers, viz., aa external anil
an internal blastodermic layer.

FORMATION OF ORGANS IN THK KBOG. 679

2. The external layer of the blastodermic membrane incloses by
its dorsal plates the cerebro-spinal canal, and by ita abdominal
plates the abdominal or visceral cavity.

8. The internal layer of the blastodermic membrane forma the
intestinal canal, which becomes lengthened and convoluted, and
commanicates with the exterior by a mouth and anus of secondary
formation.

4. Finally the cerebro-spinal axis and its nerves, the skeleton,
(he organs of special sense, the integument, and the muscles, are
developed from the external blastodermic layer; while the anterior
and posterior extremities are formed from the same layer by a pro-
cess of sprouting, or continuous growth.

580

i&ILlCAL VBSIOLI

CHAPTER VIIT

THE UMBILICAL VESICLE.

Is the frog,

have

alxli

lal

PiK. 204,

tcA, closing

together in front and underneath the body of the animal, ahac in
directly the whole of the vitcUus, and join each other upon the
median line, at the umbilicus. The whole ren^ains of the vitellus
are then inulosed in the abdomen of the animal, and in the iDtestinal
Bacj formed by the internal blastodermic layer.

In many instances, however, as, for example, in sereral kinds of
6db, and in all the birds and quadruped:*, the abdominal plates do

not immediately embrace the whole of
the vitelline mass, but tend to close
together about its middle; so that the
vitellus is constricted, in this way, and
divided into two portions: one internal,
and one external. (Fig. 204.) As the
process of development proceeds, the body
of the fcetus increases iu size, out of pro-
portiun to the vitelline sac, and the con-
Btrirtion just mentioned btjcomes at the
aame time more strongly marked; so thai
the separation between the internal and external portions of the
vitelline eac is nearly uurnplete. (Fig. 206.) The internal layer of
the blaiitodermio membrane \s by the same means divided into
two portionrt, one of which forms the intestinal canal, while the
other, remaining outside, forms a sac-like Appendage to the abdo-
men, which is known by the name of the umi>iitc<il vtticie.

The umbilical vesicle is acuordingly lined by □ [Mrtiou of the
internal blnsiodormic layer, continuous with the mucous membrane
of the intestinal canal; while it Id covered on the outside by a por-
tion of the external blasttxlernnc layer, continuous with the integu-
ment of the abdomen.

Ciiil or VlaiTi iih<>»tlJ( fuiiu*
UuBurntDMUcal *«i^la.

TBK UMBILICAL TKSICLB.

681

After the young flnimal lenvea the egg, the nmbilical vestcle
in iKime species becomes withered and atro|thie(1 by the absorption
of ita contents; while in others, the abdominal wnlls gradually

FIjt. 2«5.

T«u.Bf Pub wIUi nnMltMl *e>lal«.

extend over it, and crowd it back Into the abdumen; the nutritious
matter which it contained passing from the cavity of tlw vesicle
into that of the intestine by the narrow passage or cannl which
remains open between them.

In the human subject, however, as well as in the quadrupeds, tfae
umbilica! vesicle becomes more completely scparaicd from the abdo-
men than in the cases just mentioned. There is at 6rst a wide com-
mnnicatioii between the cavity of the umbilical vesicle and that of
the intestine; and this communication, as in other instances, becomes
gradually narrowed by the increasing constriction of the abdominal
walls. Uere, however, the constriction proceeds bo far thnt the
opposite surfaces of the canal come in contact with each r>tbcr, and
adhere; so thiit the narrow passage previously
existing, between the cavity of the intestine
and that of the umbilical vesicle, is obliterated,
and the vesicle is theu connected with the
abdomen only by an impervious cord. This
cord afterward elongates, and becomes con-
verted into a slender, thread like pedicle (Fig.
206), passing out from the abdomen of the
fcetua, and connected by its farther extremity
with the umbilical vesicle, which is filled with
a transparent, colorless fluid. The umbilical
vesicle is very distinctly visible in the human
fcetUB so late as the end of the third month.
After that period it diminishes in size, and is gradunlly lost in the
advancing development of the neighboring parts.

In the formation of the umbilical vesicle, we have the first varia-

Pig. 204.

II m *;■ Ki«>«T<>, irlih

682 THE UMBILICAL TE81CLE.

tion from the simple plan of development described in the preceding
chapter. Here, the whole of the vitellus is not directly converted
into the body of the embryo; but while a part of it is taken, as
usual, into the abdominal cavity, and used immediately for the
purposes of nutrition, a part is lefl oataide the abdomen, in the
umbilical vesicle, a kind of aecoDdary organ or appendage of the
fcstus. The contenta of the umbilical vesicle, however, are after-
ward absorbed, and so appropriated, finally, to the nourishment of
the newly-formed tissaes.

AMNION AND ALLANTOIC. 683

CHAPTEE IX.

AMNION AND ALLANTOIS.— DE VELO PMENT OF
THE CHICK.

Wk sbflll now proceed to the description of two other accessory
organs, which are formed, daring the development of the fecundated
egg, in all the higher classes of animals. These are the amnion and
the allantou,' two organs which are always found in company with
each other, since the object of the Srst is to provide for the forma-
tion of the second. The amnion is formed from the external layer
of the blastodermic membrane, the allantois from the internal layer.

In the frog and in fish, as we have seen, the egg is abandantly
flopplied with molHtare, air, and nourishment, by the water with
which it is surrounded. It can absorb directly all the gaseous and
liquid substances, wbtch it requires for the purposes of nutrition
and growth. The absorption of oxygen, the exhalation of carbonic
acid, and the imbibition of albuminous and other liquids, can all
take place without difficulty through the simple membranes of the
egg; particularly as the time required for the formation of the
embryo is very short, and as a great part of the process of develop-
ment remains to be accomplished after the young animal leaves
the egg.

But in birds and quadrupeds, the time required for the develop-
ment of the foetus is longer. The young animal also acquires o
much more perfect organization during the time that it remains
inclosed within the egg; and the processes of absorption and exha-
lation necessary for its growth, being increased in activity to a
corresponding degree, require a special organ for their accomplish-
ment. This special organ, destined to bring the blood of the foetus
into relation with the atmosphere and external sources of nutrition,
is the allantois.

In the frog and the fish, the internal blastodermic layer, forming
the intestinal mucous membrane, is inclosed everywhere, as above
described, by the external layer, forming the integument; and

084

AUNTOK AHD ALLAXTOIft.

Pig. 207.

conaequently it can nowhere come in contact witli the investing
membrane of the egg. But in the higher animalft, the internal
blastodermic layer, which i;* the seat of the greatest vascularity,
and which is destined to produce the allantois, is made to come in
contact with the external membrane of the eirg for purposes of
exhalation and absorption; and this can only be accomplished by
opening a passage for it through the external germinative layer.
This ia done in the following manner, by the formation of the
amnton.

Soon after the body of the fuetus haa begun to be formed by tbe
thickening of ihe external Inyer of the blastodermic membrane,
a double fold of this external layer risea op on nil sides about
the edges of the newly-formed embryo ; so that the body of the
foetus appears as if sunk in a kind of depression, and surrounded
with a membranous ridge or embankment, as in
Fig. 207. The embryo (e) ia here seen in profile.
with the double membranous folds, above meo-
tion^d, rising up just in advance of the head,
and behind the posterior extremity. It must be
understood, of course, that the same thing takes
place on the two sides of tbe foetus, by the forma-
tion of lateral folds simultaneously with the
appearance of those in front and behind. As it
ifl these fuhls which are destined to form the
nmnion, they arc called the "amniotic folds."

The amniotic folds continue to grow, and ex-
tend themselves, forward, backward and laterally,
uniil they approach each other at a point over
the back of the foetus (Fig. 20S), which is tcrmwl ihc "amniotic
umbilicus." Their opposite edges afterward actually come in oon-
t.'tcc with each other at this point, and adhere together, so as to
shut in a space or cavity (Fig. 2U8, b) between their inner surface
and the body of the rootus. This space, which is filled with a clear
Haid, is called the amniotic cavity. At the same time, the iutesUnal
canal has begun to be formed, and the umbilical ve:«icle has been
partially separated from it, by the constriction of the abdominal
walls on the under surface of the body.

There now appears a prolongation or diverticulum (Fig. 208, c)
growing out from the posterior portion of the intestinal canal, and
following the oourso of the amniotic fold which has preceded it:
occupying, as it gnidually enlarges and protrudes, the space left

DAran Koit; kbunlut
futmalloti of aimloii.—
o. VHdUok 6. BxtornBl
U)rt» oS tiUW'liJrtliile
iDrMtirBU*. r. H"Ay at

ttit'btyo. d.it. Aaiiil"tie
fnlJi (, Vhallloa mom-

AMNION AND ALLANT0I8,

S85

Pig. SOfi.

tinbllleiil v*Mcl«. b.

Pig. 209.

vacant by tlie rising up of the amoiotio foM. Tbis div-erliculum
18 the commeacemeQt of the allantois. It is an clooj^aiud mem-
branous sac, cuDtiDuous with the posterior portion of the tatestiae,
and ooDtaioing bloodvcjisela derived from those
of the intestinal circalation. The cavity of the
allantois is also continuous witb the cavity of
the intestine,

Af\er the amniotic folds have opproachetl and
touched each other, as already described, over
the back of the fwtus, at the amniotic umbilicus,
the adjacent surfaces, thus brought in contact,
fuse together, bo that the cavities of the two
folds, coming reflpcctivcly from front and rear,
arc separated only by a single nniembranous par*
titioa (Fig. 209, c) running from the inner to the
outer lamina of the amniotic foltta. This parti-
tion itself soon af^r atrophies and disappears; and the inner and
outer lonfiinre become consequently separated from each other. The
inner lamina (Fig. 209, a) which remains con-
tinuous with the integument of the fcetus, in-
closing the body of the embryo in a distinct
cavity, is called the amnion (Fig, 210, b), and
its cavity is known as the amuiolic cavity.
The outer lamina of the amniotic fold, on the
other hand (Fig. 2U9, b\ recedes farther and
farther from the inner, nntil it comes in con-
tact with the original vitelline membrane, still
covering the exterior of the egg; and by con-
tinued growth and expansion it at last fuses
with the vitelline membrane and unites with
its substance, so that the two membranes form
but one. This membrane, formed by the fusion
and consolidation of two others, constitutes then
the external inveating membrane of the egg.

The allantois, during all this time, is increas-
ing in siz« and vascularity. Following the course of the amniotic
folds as before, it insinuates itself between them, and of course soon
comes in contact with the external investing membrane just de-
scribed. It then begins to expand laterally in every direction,
enveloping more and more the body of the fcetus, and bringing Its
vessela into contact with the external membrane of the egg.

wtih allavioU nwrt; earn-
(>I(t« ^-d. tniier Umlim of
bDin.lcllc fsld. &. Ouini Ift-
mlna ot dlllu c- r<jljit
irli«r« the ftiniilattc Mit
C-imalb BQ&IUL. TbealliUi-
loll I* iwiid prmltitlug Iw-

IW04II Uifl luow and «a(«r
laratna of tbe ■mslvlja

full]*.

586

AMNION AND ALLANTOIS.

Fig.SlO.

TtcrwnATKv Boa, wtlh

bIUiiIiiU Tnllj funioxt — •>. t'Di>

blUcal Tralda, A, APHitun. e.
Allantwl*.

By a continuntion of tbe above process, the allantois at last
grows to auch an extent as to envelope completely the body of the
embryo, together with the amnion ; its two
extremities coming in contact witb each
other and fusing together over tbe back of
the fcctus, just as the amniotic folds har]
previously done. (t'ig.210.) It lines, there-
fore, the whole internal surface of the in-
veiiLing mcnibrnne with a flattened, voaca-
lar sac, the vessels of which come from the
interior of tbe body of tbe foetus, and which
still cuinmunicales with the cavity of the
intestinal canal.

It is evident, from the above description,
that there is a close connection between the
formation of the amnion and that of the allunlois. For it is only
in this manner that the allantois, which is an extension of the in-
teronl layer of the blastodermic membrane, can come to be siiualed
outside the fcetus and the amnion, and be brought into relation
with external surruunding media. Tbe two lamina of the amni-
otic folds, in fact, by separating from each other as above described,
oi>en a pa»^agc for the allantois, and allow it to conic in contact
with the external membrane of the egg.

In order to explain more fully the physiological action of the
allantois, we shall now proceed to describe the prooeos of develop-
ment, as it takes plnce in the egg of the fowl.

In order that the embryo may be properly developed in any
case, it is essential that it be freely supplied witb air, warmth,
moisture, and uouriabtnent. The egg of the fowl contains already,
when discharged from the generative pnasn^es, a sufficient quantity
of moisture and albuminous material. The necessary warmth is
supplied by the body of the parent during incubation ; while the
atmospheric gases can pass and repass tlirough the porous egg-
shell, and by endosmosis through the librous membranes which
line its cavity.

When the egg is first laid, the vitellus, or yolk, is enveloped in
a thick layer of semi-solid albumen. On tbe commeDoement of
incubHtion, a liquefaction takes place in the albumen irnme<lialely
above that part of the vitellus which is occupied by the cicatri-
cula; BO that the vitollua rises or floats upward toward the surface
by virtue of its specific gravity, and tbe cicatricula comes to be

DBTBLOPHEXT OF THE CHICE.

58:

placed almost immediatuly underneath t1ie lining membrane of the
egg-shell. Ab the cieatricula is the t<pot frum which the process of
embryonic development commences, the body of the young foBtua
is by this arrangement placed in the most favorable position for
the reception of warmth and other necessary external influences
through the cgg-slitdl. The liquoHtid albumen is also absorbed by
the vitelline membrane, and the vitellus chiia becomes larger, softer,
and more diffluent ihan before the commencement of incubation.

As soon as the circulatory apparatus of the embryo has been
fairly formed, two minute arteries are seen to run out from ita
lateral edges and spread oat into the neighboring parts of the
blastodermic membrane, breaking up into inosculuting branchoa,
and covering the adjacent portions of the vitellus with a plexus of
capillary blouJvesselei. The space occu[)ied in the blastodermic
membrane, on the surface of the vitellus, by these vessels, is called
[the arta iyucu^om. (Fig. 211.) It is of a nearly circular shape,

FfB. 211.

SmM ft> TnVL dnrlD( e*Tl]r [xrliidi of lacubaliuo ; ■■■■i«la^ llir buJ; nl (Iro vmlirfit, Rail Ilia
•«• »»iB>liiiM partljhjr tvrvrliif ilia •urfum a( ilio rilalla*.

nnd is iitniled, on its outer edge, by a terminal vein or sinus, called
the "sinus terminalia." The blood Is returned to the boily of the
I foetus by two veins which penetrate beneath its edges, one near the
head and one near the tail.

The area vasculosa tends Co increase in extent^ as the develop-
ment of the foetus proceeds and its circulation becomes more active.
It aoon covers the upper half, or hemisphere, of the vitellus, nnd
the terminal sinns then runs like an equator round the middle of
the vilelline sphere. As the growth of the vascular plexus con-

DBVILOPUENT OF THE CHICK. 589

the fcDtns and the vitelline sac, and taking the place of the albumen
which has been liquefied and absorbed.

It will also be seen, by reference to the figure, that the arabilical
vesicle is at the same time formed by the separation of part of the
vitellus from the abdomen of the chick ; and the vessels of the area
vasealosa, which were at first distributed over the vitellus, now
ramify, of coarse, upon the surface of the umbilical vesicle.

At last the allantois, by its continued growth, envelopes nearly
the whole of the remaining contents of the egg ; so that toward the
later periods of incubation, at whatever point we break open the
egg, we find the internal surface of the shell- membrane lined with
a vascular membranous expansion, supplied by arteries which
emerge from the abdomen of the foetus.

It is easy to see, accordingly, with what readiness the absorption
and exhalation of gases may take place by means of the allantois.
The air penetrates from the exterior through the minute pores of
the calcareous shell, and then acts upon the blood in the vessels of
the allantois very much in the same manner that the air in the minute
bronchial tubes and air-vesicles of the lungs acts upon the blood in
the pulmonary capillaries. Examination of the egg, farthermore,
at various periods of incubation, shows that changes take place in
it which are entirely analogous to those of respiration.

The egg, in the first place, during its development, loses water by
exhalation. This exhalation is not a simple effect of evaporation,
but is the result of the nutritive changes going on in the interior
of the egg; since it does not take place, except in a comparatively
alight degree, in animpregnated eggs, or in those which are not
incubated, though they may be freely exposed to the air. The
exhalation of fluid is also essential to the processes of development,
for it has often been found, in hatching eggs by artificial warmth,
that if the air of the chamber in which they are inclosed become
uodaly charged with moisture, so as to retard or prevent further
exhalation, the eggs readily become spoiled, and the development
of the embryo is arrested The loss of weight during natural incu-
bation, principally due to the exhalation of water, has been found
by Baodrimont and St Ange' to be over 15 per cent, of the entire
weight of the egg.

Secondly, the egg absorbs oxygen and exhales carbonic acid.
The two observers mentioned above, ascertained that during elgh-

' Da IMvulojtpeuietit da Foetiu. Pariit, 1S50, p. 143,

A90

AMNION ANT ALLANTOIS,

teen days' incubation, tlie egg absorbs nearly 2 per cent, of its
weigVit of oxygen, while the quantity of carbonic acid exhaled from
the sixteenth to tbe nineteenth dny uf incubation amounts to no lea
than S grfiiDs in the twenty-four hours.' U is curioua to obserre,
also, that in the egg during incubation, as well as in the adall
animal, more oxygen is absorbed than 13 returned by exhalation
under the form of carbonic acid.

It is evident, therefore, that a true respiration takes plao^ bjr
means of thu allantuis, through the mernbruiies of the shell.

The allantois, however, is not simply an organ of res|)iration ; ii
takes part also in the absorption of nutritious matter. Aa the pro-
cess of development advances, the skeleton of the young chicle, at
first entirely cartilaginous, begins to ossify. The calcareous mat-
ter, neccasary for this ossification, is, in all probability, derived fVom
the shell. The shell is certiiinly lighter and more fragile toward
the end of incubation than at first ; and, at the same lime, the cal-
careous ingredients of the bones increase in quantity. The lime-
salts, requiaito for the process of ossification, are apparently ab-
sorbed from the shell by the vessels of the allantois, and by them
transferred to the skeleton of the growing uhick ; so that, in the
same proportion that the former becomes weaker, the latter grows
stronger. This diminution in density of the shell is connected not
only with the deveiupmont of the skeleton, but alau with tlie 5nal
escape of the chick from the egg. This deliverance is aocorapliabed
mostly by the movements of the chick itself, which become, at a
certain period, surficieully vigorous to break out an opening in the
attenuated and weakened egg-shell. The first fracture is generally
accomplished by a strt^ke from iho end of the bill; and it is pre-
cisely at this {^loint that the soliditication of the dieleton is most
advanced. The egg-shell itself, therefore, which at first only servei
for the protection of the imperfecily-formed embryo, afterward
furnishes the muteriuls which are used to accomplish its own demo-
lition, and at the same time to effect the escape of the fully dove-
loped foetus.

Toward the latter periods of incubation, the allantois becomes
more and more adherent to the internal surface of the shell-mem-
brane. At last, when the chick, arrived at the full (wriod of de-
velopment, escapes from its confinement, the allantoio vessels are
torn off at the umbilicus; and the allantois itself, cast off as «

Op. «fl., p|«. 13S And U9.

D£VELOPHSlfT OF THE CHICK. 601

less and e£fete organ, is left behind in tbe cavity of the abandoned
cgg-BheU. Tbe allantois is, therefore, strictly speaking, a foetal
organ. Dereloped as an accessory structure from a portion of the
intestinal canal, it is exceedingly active and important during the
middle and latter periods of incubation ; but when the chick is
completely formed, and has become capable of carrying on an in-
dependent existence, both the amnion and the allantois are detached
and thrown off as obsolete structures, their place being afterward
supplied by other organs belonging to the adnlt condition.

592 PEVBLOPllBKT 07 TRB 100 tK HVMaTbPECIES.

CHAPTER X.

DEVRtOPMENT OF THE EGO IN THE HUMAN
SPEU1K3. — FORMATION OF THE CHORION.

Fig. 213.

We have already described, in a preceding clispter, the manner
ID which the outer lainiaa of the amniotic fold becomes adherent
to the adjacent surface of the vitellino membrane, so as to form
with it but a single hiyer; and in which these two membranes, thus
fused and utiiled, with each otiier, form at that time the single ex-
ternal investing membrane of the egg. The allantois, in its turn,
afterward comes in contact with the investing mernbraoe, and lies
immediately beneath it, as a double vaacular membranous sac In
the egg of the human Hubjcct the development of the membranea,
though cfirrled on es9entlal!y upon the same phin with that which
we havu already described, undergoes, ia addition, some further
modification a, which we shall now proceed to explain.
The first of these peculiarities is thai the altantois, alVer spread-
ing out u|x>n the inner surface of
the external investing membraae.
adheres to, and fuses with it, just
UH the outer lamina of the amni-
otic fold has previously fused
with the vitelline membrane. At
the same time, the two layers be-
longing to the allaniois itself hIm
come io contact and fuse toge-
ther; so that the cavity of the
allantoia ia obliterated, and iDsteaJ
of forming a membranous sao ooo<
taining 6uid, this organ is cont>ert-
cd into a timph voscular moHbrwtt.
(Fig. 213.) This membrane,
moreover, being, after a time, thoroughly fused and united with the
two which have preceded it, takes the place which was previously

Hu«AM uto«, abool Iba and al rlin ilnit
nomb : tli«*rlii4 tuimailnii at cburtnn. — I.
Omb(Uc»l raiict*. 2. AronWu. 1, ChurLoa.

FOBUATIOK OF THE CHOBION. 698

occupied by them. It is then termed the chorion, and thus becomes
the sole external investing membrane of the egg.

We find, therefore, that the chorion, that is, the external coat or
investment of the egg, is formed soccessivelj by three distinct
membranes, as follows: first, the original vitelline membrane;
secondly, the oater lamina of the amniotic fold; and, thirdly, the
allantois; the last predominating over the two former by the rapidity
of its growth, and absorbing them into its substance, so that they
become finally completely incorporated with its texture.

It is easy to see, also, how, in consequence of the above process,
the body of the foetus, in the human egg, becomes inclosed in two
distinct membranes, viz., the amnion, which is internal and conti-
nnona with the fcetal integument, and the chorion, which is external
and supplied with vessels from the cavity of the abdomen. The
ambilical vesicle is, of course, situated between the two; and the
rest of the s|^e between the chorion and the amnion is occupied
by a semi-fluid gelatinous material, somewhat similar in appearance
to that of the vitreous body of the eye.

The obliteration of the cavity of the allantoia takes place very
early in the human subject, and, in fact, keeps pace almost entirely
with the progress of its growth; so that this organ never presents,
in the human egg, the appearance of a hollow sac, filled with
fluid, but rather that of a flattened vascular membrane, enveloping
the body of the fcetus, and forming the external membrane of the
egg. Notwithstanding this difference, however, the chorion of the
hnman subject, in respect to its mode of formation, is the same
thing with the allantois of the lower animals; its chief peculiarity
consisting in the fact that its opposite surfaces are adherent to each
other, instead of remaining separate and inclosing a cavity filled
with fluid.

The next peculiarity of the human chorion is, that it becoma
shaggy. Even while the egg is still very small, and has but recently
found its way into the uterine cavity, ita exterior is already seen
to be covered with little transparent prominences, like so many
villi (Fig. 21S), which increase the extent of its surface, and assist
in the absorption of fluids from without The villi are at this time
qaite simple in form, and altogether homogeneous in structure.

As the egg increases in size, the villi rapidly elongate, and be-

comedivided and ramified by the repeated budding and sprouting of

lateral offshoots from every part. After this process of growth has

gone on for some time, the external surface of the chorion presents

5»4 DEVELOPMENT OF TflE KOQ IK HUUATT 8PECIBB.

a uniformly velvety or shngi^y &\

to its bei

Fig. 214.

«^,

ppcararice, ov
vereJ everywhere with these tul\ed and compound villosiiies.

The villositios themselves, when examined by the inioroscope,
have on exceedingly well-markod and characteristic appearance.
(Fig. 214.) They originate from the surface of the chorion by a

somewhat narrow stem, and divide
into a multiiudo of secondary and
tertiary branches, of varying size
and figure; some of them slender
and filameDtoua, others club-shaiwd,
many of them irregularly swollen at
varioua points. All of them termi*
Date by rounded extremities, giving
to the whole tuft a certain resem-
blance to some varieties of sea-weed.
The larger tranks and branches of
the villosity are seen to contain nn*
men>iJ8 minute nuclei, imbedded in
a nearly homogeneous, or finely gra-
nular subtilratum. The smaller ones
appear, under n low magnifying
power, simply granular in texture.

These villi are altogether peculiar
in appearance, and quite unlike any
other .strncturc which may be met with in the body. Whenever we
find, in the uterus, any portion of a membrane having viltosities
like these, we may be sure that pregnancy has existed; for such
villoaitics can only belong to the chorion, and the chorion itaelf is
a part of the fcBtns. It is developed, as we have seen, aa an out-
growth from the intestinal canal, and can only exist, accordingly,
as a portion of the fecundated egg. The presence of portions of a
shaggy chorion. is therefore us satisfactory proof of the existcuce
of pregnancy, aa If wc had found the body of the fo^tua itaelf.

While the villosiiies which we have just described are in pro-
cess of formation, the allantois itself has completed its growth, and
has become converted into a permanent chorion. The bloodvessels
coming from the allantoic arteries accordingly ramify over the
chorion, and supply it with a tolerably abundant vascular network.
The growth of the fcetiis, moreover, at this time, has reached ancb
a state of activity, thai it requires to be supplied with nourishment
by vascular absorpUon, instead of the slow process of imbibition,

CnmpoDoit rlllmlir of Brajm Ctif-

nmDItia' (iBtum. Hugtilfliil 3n itltiurlara.

rOBHATIOir OF THK CHORION. 595

wbich haa heretofore taken place through the comparatively incom-
plete and Btroctarelesa villi of the cho-
rion. The capillary vessels, accordingly, Fig. 215.
with which the chorion ia snpplted, begin
to penetrate into the aabstance of its vil-
loaities. Thay enter the base or stem of
each villoeity, and, following every divi-
sion of its compound ramifications, finally
reach its rounded extremities. Here they
turn upon themselves in loops (Fig. 216),
like the vessels in the papilla^ of the skin,
and retrace their course, to unite finally
with the venous trunks of the chorion.

The villi of the chorion an therefore j,,„„,„ „, ,„,„,„, „
very analogous in structure to those of cwobiow, man higbiy mtcoi-
the intestine ; and their power of absorp- bi,«d»,M^. n, i<. i«t*rior.
tioQ, as in other similar instances, corre-
sponds with the abundance of their ramifications, and the extent
of their vascularity.

It must be remembered, also, that these vessels all come from the
sbdomen of the fcatua; and that whatever substances are taken up
by them are transported directly to the interior of the embryo, and
used for the nourishment of its tissues. The chorion, therefore, aa
soon as its villi and bloodvessels are completely developed, becomes
an exceedingly active organ in the nutrition of the fcetus; and con-
stitutes, iu fact, the only means by which new material can be in-
troduced from without.

The existence of this general vascularity of the chorion affords
also, as Coste was the first to point out, a striking indication that
this membrane is in reality identical with the allantois of the
lower animals. If the reader will turn back to the illustrations of
the formation of the amnion and allantois (Chap. IX.), he will see
that the first chorion or investing membrane is formed exclusively
by the vitelline membrane, which is never vascular and cannot be-
come so by itself, since it has no direct connection with the foetus.
The second chorion is formed by the union of the vitelline mem-
brane with the outer lamina of the amniotic fold. Both laminea
of the amniotic fold are at first vascular, since they are portions of
the external blastodermic layer, and derive their vessels from the
integument of the foetus. But afWr the outer lamina has become
completely separated from the inner, by the disappearance of the

596 DETELOPMSXT OP THE EOO Ty JSUHATt SFKC'IES.

partitioD which for a time connected the two with each other (Fig.
209, c)i this source of vascular supply is cut off; and the Becond
chorion cannot, therefore, remuin vascular afler that period. Bat
the third or permanent chorion, that is, the allantois, derives ita Tea-
sels directly from those of the fcetus, and relftios its connection with
them daring the whole period of gestation. A chorion, therefore,
which is universally and permanently vascular, can be no other
than the alkntois, converted into an external investing membnoe
€>f the ogg.

Thirdly, the chorion, which is at one time, as we have seen, every-
where villous and shaggy^ becomes a/ierward partiaUi/ baiU. This
change begins to take place about the end of the second month.
It commences at a point opposite the aituaiion of the foetus and the
insertion of the fcetal vessels. The viltosities of this region cease
growing; and as the entire egg continues tu enlarge, the villosities
at the puint indicated fail to keep pace with its growth, and with
the progressive expansion of the chorion. They accordingly be-
come nt this part thinner and mure scattered, leaving the surface
of the chorion comparatively smooth and buUI. This baldness in-
creases in extent and becomes more and more complete, spreading
and advancing over ihe adjacent portions of the chorion, until at
least two-thirds of its surface have become nearly or quite destituic
uf villositics.
At the opposite point of the surface of the egg, however, that

portion, namely, which corre
^t- *^^' sponds with the insertion of

thefuital vessels, the villosities,
instead of becoming atrnphied,
continue to grow; and this
portiyu of the chorion becomes
even more shaggy and thickly
set llian before. T)ie conse-
quence is that the chorion
afterward presents a very dif-
ferent appearance at diflVrent
portions of its surface. (Fig.
216.) The greater part of it is
smooth; but a certain portion.
coiistiiuUng about one- third of
the whole, is covered with a soft and spongy moss of long, thickly-
Kt, compound villosities. It is this thickened and shaggy portion,

tl I- > A « U T c ■ ■! eiid ill llitrJ iDuulli ; ■!>'

Hue

rOBUATION' OF THE CHOBIOK. 597

which is afterward concerned in the formation of the phcenia;
while the remainiog smooth portion continues to be known under
the name of the cborioa. The placental portion of the chorion
becomes distinctlj limited and separated from the remainder by
about the end of the third month.

The vascularity of the chorion keeps pace, in its different parts
respectively, with the atrophy and development of its villosities.
As the villosities shrivel and disappear over a part of its extent,
the looped capillary vessels, which they at first contained, disappear
also ; so that the smooth portion of the chorion shows aflerward
only a few straggling vessels running over its surface, and does not
contain any abifndant capillary plexus. In the thickened portion,
on the other hand, the vessels lengthen and ramify to an extent
oorresponding with that of the villosities in which they are situated.
The allantoic arteries, coming from the abdomen of the fcetus, enter
the villi, and penetrate through their whole extent; forming, at the
placental portion of the chorion, a mass of tufted and ramified vas-
cular loops, while oVer the rest of the membrane they are merely
distribated as a few single and scattered "vessels.

The chorion, accordingly, is the external investing membrane of
the egg, produced by the consolidation and transformation of the
allantois. The placenta, furthermore, so far as it has now been
described, is evidently a part of the chorion ; that part, namely,
which is thickened, shaggy, and vascular, while the remainder is
comparatively thin, smooth, and membranous.

698 DBVELOPICBNT OF CTBRl

rsuBRAyi

CHAPTER XI.

DEVELOPMENT OF UTERINE MUCOUS MEMBBANE.
FORMATION OF THE I>KCIDUA.

I>" fisb, peplilea, and birds, ihe egg is either provided wiih a sap-
plj of' nntrilioua mftterial contained within its meinbraDes, or it is
BO placed, after its discbarge from the body of the parent, that it
can absorb these materials from without. Thus, in the egg of the
bird, the young embryo is supportoti upon the albuminous matter
deposited around the vitellu^; while in the frog and fish, moisture,
oxygen, saline substances. &c., are freely imbibed from the water
in which the egg is placed.

But in the quadrupeds, as well as in the human species, the ^g
is of minute !>izc, and the (quantity of nutritious matter which it
contains is sufficient to Inst only for a very short time. Moreorer,
the developmeot of the ftjetus takes place altogether within the body
of the female, and no supply, therefore, can be obtained directly
from the external media. In these instances, accordingly, t)ie raQ<
cons membrane of the uterus, which is found to be unusually
developed and increased in functionu! activity during the period of
gestation, becomes a source of nutrition for the fecundated e^.
The uterine mucous membrane, thus deveh>ped and hypertrophied,
is known by the name of the Ihciduti.

It has received this name because, as we shall hcrenflcr see, it
becomes exfoliated and thrown oO', at the same time that the
itself is linully discharged.

The niucousmerabroneof the body of the uterus, in the unimpi
nated comlitioii, is quite thin and delicnte, and presents a smooth
and slightly vascular internal surface. There is, moreover, no layer
of submucous cellular tissue between it and the muscular substance
of the uterus; so that the mucous membrane cannot here, as in
most other organs, bo easily dissected up and separated from the
subjacent parts. The structure of the moooua membrane itaelf,
however, is sufficiently well marked and readily distinguishable

TORMATtON OF THl DECIDtTA.

B«0

from that of other

Fig. 217.

Mcci Id rrrllul •r<il<ru.--it. VrvrtaibKe.
b. MU,€\irA tailkr*.

parts. It conaijta, throughout, of mioute
tubular fullictee. ningeil side by side, and running perpendicularly
to the free surface of the muooua memhrane. (Fig. 217.) Near
this free surface, they are nearly
straight; but toward the deeper sur-
face of the mucous mennbrane, where
they terminate in blind extremities,
they become more or less wavy or
spiral in their course. The tubules
are about -j^g of an inch in diameter,
and are tiued throughout with co-
lumnar epithelium. (Fig. 218.) They
occupy the entire thickneaa of the ute*
rine mucous membrane, their closed
extremities resting upon the subjacent

muscular tiswuc, while their mouths open into the cavity of the ute-
rus. A few fine bloodvessels pcDelrate the mucous membrane from
below, and, running upward

between the tubules, encircle P**- 218.

their superficial extremities
with a capillary network.
There is no areolar tissue in
the uterine mucous mem-
brane, but only a amntl quan-
tity of apindle-shnped fibro-
plastic fibres, scattered, be-
tween the tubules.

As the fecundated egg is
■bout to descend into the
cavity of the uterus, the mu-
cous membrane, above de-
scribed, lakes on an increased
activity of growth and an
unusual developmeut. It be-

comea tumefied and vascular; and, ns it increases in thickness, it
projects, in rounded eminences or convolutions, into the uterine
cavity. (Fig. 21».) In this process, the tubules of the uterus in-
crease in length, and also become wider; so that their open mouths
may be readily seen by the naked eye upon the uterine surface, as
numerous minute perforations. The bloodvessels of the mucous

embrane also enlarge and multiply, and inosculate freely with

DrimiMt Tr»i'i.«». fr"in manni' xfabnaa {•!

600 DEVELOPMENT OF

!S MUCOUS MBMBBAKK.

each other; so that the vascular network encircling the tubolesbe
oomes more extensive and abundant.

The internal surface of the nterua, accordingly, after this procoa
baa been for somo time going on, preuents a thick, ricb, 8oft,Ta9-
onlar, and velvety lining, quite different from tbat vbtch is to Ik
found in the unimprcgnatcd condition. In consequence of tliit
difference, the lining Dietnbrane of the ut«rus, in the impregaated
condition, was formerly supposed to be an entirely new prodoo,
thrown out by e^cudatinn from the uterine surface, and aoali^oafc
in tbia respect, to the inBammatory exudations of croop and pW-
risy. It is now known, however, to be no other than the tnocou
membrane of the uterus iteetf, thickened and hjpertrophied loia
extmordinary degree, but still retaining all its natural cnnnectioos
and its original anatomical structure.

The hypertrophied mucous membrane, above described, ooi»ti-
tutes the Decidua vera. Its formation is confined altogether to tbe
body of the uterus, the mucous membrane of the cervix taking no
part in the process, but retaining its original appcaranoe. Hie
deciilua vera, therefore, commences above, at the orifices of tbe
Fallopian tubes, and ceases below, at the situaUon of tbe oi iater-
num. Tbe cavity of tbe cervix, meanwhile, begins Co be filled
with an abundant secretion of its peculiarly viscid mociUi whidi
blocks up, more or less completely, ita paasage, and protects tbe
internal cavity. But there is no membranous partition at this time
covering the os internum, and the mucoua membranes of tbe cervix
and of tbe body of the uterus, though very different in appearance,
are still perfectly continuous with each other. When we cat open
tbe cavity of the uterus, therefore, in this condition, we find tti
internal surface lined with the decidua vera, with the opening of
the oa internum below and tbe orifices of the Fallopian tabes above,
perfeclly distinct, and in their natural positions. (Kig. 219.)

As the fecundated egg, in its journey from above downward,
passes tbe lower orifice of the Fallopian tube, it insinuates itaelf
between the opposite surfaces of the uterine mucous membrvK^
and becomes soon af^rward lodged in one of the furrows or de-
pressions between the projecting convolutions of the dectdot.
(Fig. 2\Q.) It is at this situation that an adhesion subseqaeotly
takes place between the external membranes of the egg, on ike
one hand, and the uterine decidua on the other. Now, at the potot
where tbe egg becomes fixed and entangled, as above stated, a still
mure rapid development than before taked place in tbe nteriae

FOBUATION OF THS SECIDITA.

601

mncoas membrane. Its projecting folds begin to grow up aroand
the egg in snch a manner as to partially inclose it in a kind of
drcamvallation of the decidaa, and to shot it o(£, more or less com-

Flg. 219,

Fig 220.

larmiiaaATiB Uriitri; ihowtDs
fcmfttlDi of dMidwk Tbe dteldn> ti
r«prM«nl«d Is black ; aod the rgf !■
■MD, ml Iha ftrndni of tha nterna, en-
gtfvd batwMB two of lU proJ«etln|
eoBTolnttou.

iMFimaATID Dtbbd*, vllh pro
]««tlng told* of daoldak growing op
■roasd the •((. Tb« nmmw opeoing,
where tba edgei of Ihe foldi appniMfa
«Bob other, li Men over the meet promt-
nent portloa of the egg.

Fig. 221.

pletely, from the general cavity of the nteras. (Fig. 220.) The egg
is thos soon contained in a special cavity of its own, which still
communicates for a time with the general cavity of the uterus by
a small opening, situated over its most prominent portion, which
is known as the "decidual ambilicus." As tbe above process of
growth goes on, this opening becomes narrower and narrower, while
the projecting folds of decidua approach each other over the sur-
face of the egg. At last these folds actually touch each other and
unite, fortning a kind of cicatrix which
remains for a certain time, to mark the
situation of the original opening.

"When the development of the uterus and
its contents has reached this point (Fig.
221), it will be seen that the egg is com-
pletely inclosed in a distinct cavity of its
ow^; being everywhere covered with a
decidual layer of new formation, which
has thus gradually enveloped it, and by
which it is concealed from view when the
Dterine cavity is laid open. This newly-
formed layer of decidua, enveloping, as i«f«b<i!iatii. utbbc*:-

, 3 •! 1 I - ■ • (• •hawing egg cumplelel; locloHid

above described, the projecting portion of by doeidu» roHexn.

DKVBLOPWBNT OP UTBBISE WCCOP9 MKMBKATTR.

the egg, 18 called the Dfcidua rejlexa; bectnise it is reflected over
the egg, by a continaoun growth from the general fliirrace of the
uterine mucous membrane. The oriScea of the uteriDe tubules,
accordingly, id consequeoce of the manner in which the decidua
reflexa is furmed, will be seen nut only on its external surface, or
that which looks toward the cavity of the uterus, but alao on iu
internal surface, or that which looks toward the ^g.

The decidua vera, therefore, is the original mucous membraae
lining the Eurfnce of the uterus; while the decidua reflexa is a new
formation, which has grown up round the egg and inclused it in a
distinct cavity.

If abortion occur at this time, the inucoua membrane of the
uterus, that is, the decidua vera, is ihrown off, and of course brings
away with it the egg and decidua re&exa. On examining the mass
discharged in such an ubortion, ihc egg will acoordiogly be found
imbedded in the substance of the decidual membrane. One side
of thia membrane, where it has been torn away from its atiacliment
to the uterine walls, is ragged and shaggy; the other side, corres-
ponding to the cavity of the uterus, is sinuoth or gently convoluted,
and presents very distinctly the orifices of the uterine tubulet;
while the egg itaelf can only be extracted by cutting through the
decidual membrane, either from one side or the other, and opening
in this way the special cavity in which it has been inclosed.

During the formation of the decidua rcflcxa, the entire egg, as
well as the body of the uterus which contains it, has considerably
enlarged. That portion of the uterine mucous membrane situated
immediately underneaih the egg, and to which the egg first became
attached, has also continued to increase in thickness and viacularity.
The remainder of the decidua vera, however, ceaaes to grow as
rapidly as before, and ao longer keeps pace with the iQcreasiDg
size of the egg and of the uterus. It is still very thick and vascu-
lar at the end of the third month; but afler that period it becomes
comparatively thinner and less glandular in appearance, while the
unusual activity of growth and development is concentrated in the
egg, and in that portion of the uterine mucous membrane which is
in immediate contact with it.

Let us DOW see in what manner the egg becomes attached to the
decidual membrane, so as to derive from it the requisite supply of
nutritious material. It must be recollected that, while the above
changes have been talcing place in the walla of the uterus, the
formation of the embryo in the egg, and the development of the

FOTtMATIOX OF THE DECIBTTA. 608

amnioa and chorion have been going on simnllaneoualj. Soon
after the entrance of the egg into the uterine cavity, its external
inresting membrane becomes covered with projecting filaments, or
Tilloaities, as previoasly described. (Chap. X.) These villosities,
which are at first, as we have seen, solid and non-vascular, insinuate
themselves, as they grow, into the uterine tubules, or between the
folds of the decidual surface with which the egg ia in contact, pene-
trating in this way into little cavities or follicles of the uterine
mncoas membrane, formed either from the cavities of the tubules
themselves, or by the adjacent surfaces of minute projecting folds.
When the formation of the decidua refiexa is accomplished, the
chorion has already become uniformly
shaggy; and its villosities, spreading in all F^|^222.

directions from its external snrboe, pene-
trate everywhere into the follides above de-
scribed, both of the decidua vera underneath
it, and the contiguous surface of the decidua
refiexa with which it is covered. (Fig. 222.)
Id this way the egg becomes entangled
with the decidua, and cannot then be read-
ily separated from it, without rupturing
some of the filaments which have grown
from its surface, and have been received
into tbe cavity of the loilicies. The nu- ihowipf cdddmudd beivHn *ii-
tritioos fluids, exuded from the soa and '•^"T "' *''*^°° ""' ''""''■'
glandular textures of the decidua, are now

readily imbibed by the villosities of the chorion ; and a more rapid
supply of nourishment Is thus provided, corresponding in abun-
dance with tbe increased and increasing size of the egg.

Very soon, however, a still greater activity of absorption be-
comes necessary; and, as we have seen in a preceding chapter, the
external membrane of the egg becomes vascular by the formation
of the allantoic bloodvesaela, which emerge from the body of the
foetus, to ramify in the chorion, and penetrate everywhere into the
villosities with which it is covered. Each villosity, then, as it lies
imbedded in its uterine follicle, contains a vascular loop through
which the foetal blood circulates, increasing the rapidity with which
absorption and exhalation take place.

Subsequently, furthermore, these vascular tu^s, which are at first
uniformly abundant throughout the whole extent of the chorion,
di8api)ear over a portion of its surface, while they at the .<umo time

DEVELOPMENT OF UTEBTKE ML^COCS UEMDRAXE.

Ffg. 2S3.

become concentrated and still further developed At a particolir
spot, the situattoD of the future placenta. (Fig. 223.) This is tkc

spot at which the egg is in contact wiiii
the decidua vera. Here, therefore, both
the decidual luembraDe and the tafb
of the chorion continue to increase in
thickness and vascularity ; while else-
where, over the prominent portion of
the egg, the uhorion not only beoamei
bare of viUositioa, and comparaiiTolf
destitute of vessels, but the decidua re-
flexa, which is in contact with it, abo
loses its activity of growth, and be-
comes expanded intoathin layer.nearlT
destitute of vessels, and without an/
remainiag trace of tubules or foUidcs.
The uterine muooue membrane i>
therefore developod,dunng the prooeas
of gestation, in such a way or to proride
for the nourishment of the foetus in the difterenl stages of its growth.
At first, the whole of it is uniformly increased in thickness (decidoa
vera). Next, a portion of it grows upward around the egg. and
covers its prujuuting surface (dcuidaa reflexa). Afterward, both lbs
decidua reflexa and the greater part of the decidua vera dimimsii
in the activity of their growth, and lose their importance aaa raetM
of nourishment for the egg; while that part which a in contact with
the vascular tufts of the cborion continues to grow, becoming ex-
ceedingly developed, and taking an active part in the formation </
the placonia.

In the following chapter, we shall examine more particularly th«
structure and development of the placenta itself, and of thoao port*
which are immediately connected with iu

r>tn>«tliiii of plMvuM, by Ilia aill«4
it*veli>piaaiil u( a purtlu-w of lh« ite-
ebdiii and llin *lllailU« uf (It* shu-
riun.

THE PLACEN'TA. 805

CHAPTER XII.

THE PLACENTA.

"We have showo in the preceding chapters that the fcetus, during
its dereloptnent, depends for its supply of nutriment upon the lining
membrane of the maternal uterus;, and that the nutriment, so sup-
plied, ia absorbed by the bloodvessels of the chorion, and transported
in this vay into the circulation of the foetus. In all instances, ac-
cordingly, in which the development of the foetus takes place within
the body of the parent, it is provided for by the relation thos esta-
blished between two sets of membranes; namely, the maternal
membranes which supply nourishment, and the fcetal membranes
which absorb it.

In some species of animals, the connection between the maternal
and foetal membranes is exceedingly simple. In the pig, for ex-
ample, the uterine mucous membrane is everywhere uniformly
vaacmlar ; its only peculiarity consisting in the presence of nume-
rooa transverse folds, which project from its surface, analogous to
the valvule conniventes of the small intestine. The external in-
vesting membrane of the egg, which is the allantois, is also smooth
and uniformly vascular like the other. No special development of
tissue or of vessels occurs at any part of these membranes, and
no direct adhesion takes place between them; but the vascular
allantois or chorion of the foetus is everywhere closely applied to
the Tascatar mucous membrane of the maternal uterus, each of the
two contiguous surfaces following the undulations presented by the
other. (Fig. 224.) By this arrangement, transudation and absorp-
tion take place from the bloodvessels of the mother to those of the
foetus, in sufficient quantity to provide for the nutrition of the latter.
When parturition takes place, accordingly, in these animals, a very
moderate contraction of the uterus is suflicient to expel its contents.
The egg, displaced from its original position, slides easily forward
over the surface of the uterine mucous membrane, and is at last
discharged without any hemorrhage or laceration of connecting
parts. In other instances, however, the development of the fcetud

906

TDK PLACENTA.

requires a more elaborate arrangement of the vascular membruOL
Id the cow, for exampl'e, the external membrane of the egg, beside

Fi<[. 22i.

Tnril. Pill, Willi lu niniiiliiiium, «iuiali<i-ii m utu/ ••!
«, * C*Tlir at ultroa. U. Aublitb. (, «. AllnuituU.

'1. t.b.^ Wkllt of Mvm.

being everywhere supplleil wiUi bruauhing vecetels, presuDttt upon
various points of ltd surroco no ]es.s than from seventy to eighty oval
Bpota, at each of which the vessels of the chorion are developed into
abundant tufted promioenccs, hanging from its exterior aa a thiek,
velvety, vascular mass. At each point of the uterine mucous mem-
brane, corre8[)onding with one of these tufted masses, the maternal
bloodvessels are developed in a similar manner, projecting into the
uterine cavity as a flattened rounded mass or cake; which, with that
part of the foatal chorion which Is adherent to it, is known by the

Ffft. 225.

CoTTi.«i>"i 111" C'iw'» I'tkbdi — ••. 'I "iirfxw r>f fiBia) tbiiHiiii 4. ft lu vic—^U ol ft»'»l
•k*ftM. d, d. BloodfaawU of olatlBf niteoiu n«Bibrki>«. «, & SsrlkM o( gurlti* ii>a«oai ■«(■
Vim.am.

name of the Cotyledon. Kach cotyledon forms, therofore, a litUe
placenta. (Fig. 225.) In its substance the tufted vascular loop»

THS PLACENTA. 607

coming from the uterine macoua membrane {d, d) are entangle«l
with those coming from the membranes of the fcetos (6, b). There
is DO absolnte adhesion between the two 'sets of vessels, but only
an interlacement of their ramified extremities; and, with a little
care in manipalation, the fcetal portion of the cotyledon may be
extricated from the maternal portion, without lacerating either. In
consequence, however, of this intricate interlacement of the vessels,
transudation of fluids will evidently take place with great readiness,
from one system to the other.

The form of placenta, therefore, met with in these animals, is one
in which the bloodvessels of the foetal chorion are simply entangled
with those of the uterine mucous membrane. In the human sub-
ject, the structure of the placenta is a little more complicated,
though the main principles of its formation are the same as in the
above instances.

From what has been said in the foregoing chapters, it appears
that in the human subject, as well as in the lower animals, the
placenta is formed partly by the vascular tufts of the chorion,
and partly by the thickened mucous membrane of the uterus in
which they are entangled. During the third month, those portions
of the chorion and decidua which are destined to undergo this
transformation become more or less distinctly limited in their form
and dimensions; and a thickened vascular mass, partly maternal
and partly foetal in its origin, shows itself at the spot where the
placenta is afterward to be developed. This moss is constituted in
the following manner.

It vill be recollected that the villi of the chorion, when first
fimnedi penetrate into follicles situated in the substance of the
Qterioe mucous membrane; and that after they have become vas-
oalar, they rapidly elongate and are developed into tufted ramifi-
oations of bloodvessels, each one of which turns upon itself in a
loop at the end of the villus. At the same time the uterine follicle,
into which the villus has penetrated, enlarges to a similar extent;
aendlng out branching diverticula, corresponding with the multi-
plied ramifications of the villus. In fact, the growth of the follicle
and that of the villus go on simultaneously and keep pace with
each other; the latter constantly advancing as the cavity of the
former enlarges.

But it is not only the uterine follicles which increase in size and
in complication of structure at this period. The capillary blr)o(I-
vessels, which lie between them and ramify over their exterior,

608

THE PLAOBNTA.

also become unusually developed. Tbey enlarge and inosculate
freely witti each other; so that every uterine follicle is soon covered
wiih an abundant network of dilated capillaries, derived from thu
bloodvessels of the original dcciJua. At this time, therefore, each
vascular loop of the fatal chorion is covered, first, with a layer
forming the wall of ihe villus. This Is in contact with the Uaiug
membrune of a utenne follicle, and outside of this again are the
capillary vessels of the uterine mucous membrane; so that two
distinct membranes intervene between the walls of the foetal capil-
laries on the one band and those of the maternal capillariea on the
other, and all transudation roust take place through the substaoce
of these two membranes.

As the formation of the placenta goes on, the anatomical arrange-
ment of the fecial vessels remains the same. They oontinne to
form vascular loops, penetrating deeply into the decidual mem-
brane; only they become coostaQtly more elongated, and their
ramifications more abundant and tortuous. The n)nt«rnal capilla-
ries, hoM'cver, situated on the outside of the uterine follicles, become
considerably altered in their anatomical relations. They enlarge
excessively; and, by encroaching constantly upon the little islets
or spaces between thero, fuse successively with each other; and,
losing gradually in this way the characters of a capillary network,
become dilated into wide sinuses, which communicate freely with
the enlarged vessels in the muscular walls of the uterus. As the
original capillary plexus occupied the entire thickness of the
hypcrtrophied decidua, the vascular sinuses, into which it is thus
converted, are equally extensive. They oommoneo at ihe inferior
surface of the placenta, where it is in contact with the muscular
walls of the uterus, and extend through its whole tbickoess, quite
up to the surfaoo of the ftutal choriuu.

Ah the maternal ainuscs grow upward, the vascular tufls of the
chorion grow downwaixl, and uxtuiid also through the entire thick-
ness of the placenta. At this period, the development of the blood-
vessels, both in the fcetal and maternal portions of the placenta, is
so excessive that alt the other tissues, which originally co-existed
with them, become retrograde and disappear almost altogether. If
.1 villus from the ffctal portion of the placenta bo examined at this
lime by transparency, in the fresh condition, it will be seen that iu
bloodvessels are covered only with a layer of homogeneous, or finely
granular material, j„*gjj of an inch in thickness, in which are im-
bedded small ovalsliaped nuclei, sintilar to those seen at an earlier

THE PLACESTA.

609

Fig. 22«.

period in the villosHies of the chorion. The villoslties of the cho-
rioo are qow, therefore, hardly anything more than ramified and tor-
tuous vascular loops: tho remainiug sub-
atjtace of the villi baring been atrophied
and absorbed in the excessive growth of
the bloodvessels. (Fig, 226.) The uterine
follicles have at the same time lost all traee
of their original structure, and have bo-
come mere vascular sinuses, into which
the eufWd fc^etal bloodvessels are receivetl,
as the villoaitiss of the chorion were at
first received into the uterine fullicles.

Finally, the walls of the fcetal blood-
vessels having come into close contact
with the walla of the maternal aiuuues, the
two become adherent aud fube lugetlicr; so
that a time at last arrives, wheu we oan

no longer separate the foetal vessels, in the substance of the pla-
centa, from the maternAl sinuses without lacerating either the one
or the other, owing to the secondary adhesion M-bich baa taken place
between them.
, The placenta, therefore, when perfectly formed, has the structure

\ which is shown in the accompanying diagram (Kig. 227), ropro-

Kxmmity of rotitTcrt of
huuAh ptiuonlAl from mo tujoclffd
■inwiinva. UagalSed lOdlstyiitan.

Fig. 227.

Vartkal wrlloii nf Plarki'TA, aho 1*11111 amin^iimBar iif raalaroal and fvul latavU u, u. (A*"

«10

THR PLACENTA.

senting a venlcnl section of the organ througb its entire thicVocM.
At a, a, is seen the chorion, receiving the ambilical vessels from the
body of the foetus through the umbilical e«rd, and sending out its
vompound and ramified vascular tuftfi into the substance of the
placentA. At b A, is the attached surface of the decidua, or uterine
muuous meoibrane; and at c, c, c, c, are the ori6ce8 of uterine ves-
sels which penetrate it from below. These vessels enter the placenta
in an extremely oblique direction, though they are represented in
the diagram, for the sake of dtstinctneas, as nearly per|iendicular.
When they have once penetrated, however, the lower portion of
the decidua, they itnmediately dilate into the placental sinaM«
(represented, in the diagram, in blacky which extend through the
whole tliickiican of the orgnii, closely embrocing all the ramifica-
lions of the fuBtal tofts. It wilt be Been, therefore, that the placenta,
arrived at this staee of completion, ia composed essentially of no-
thing but bloud vessels. No other tissues enter into its structure;
for all those which it originally contained have disappeared, except-
ing the bloodvessels of the foetus, entangled with and adherent to
the bloodvessels of the mother.

Tliere Is, however, no direct oommunicslion between the fcelal
and mncornnl vessels. The blood of the foetus is always separated
from tbe blood of the mother by a membrane which has resulted
from the successive union and fusion of four difiercnt membranes,
viz., first, the membrane of the foMal villus; secondly, that of the
uterine follicle; thirdly, the wall of the foetal bloodvessel; ^dcI,
fourihly, the wall of the uterine sinus. The single membrane, how-
ever, into which these four finally coalesce, is extremely thin, as
we have seen, and^ of enormous extent, owing to the extremely
abundant branching and subdivision of the foetal tuf^ These tufts,
accordingly, in which the blood of the foetus circulates, are bathed
everywhere, in the placental sinuses, with the blood of the mother;
and the processes of endosmosis and exosmosia, of exhalation and
ubsorptioD, go on between the two with the greatest pOMible
activity.

It is very ea^y to demonstrate the arrangement of the foetal
tufts in the human placenta. They can be readily seen by the
naked eye, and miiy be easily traced from their attachment at the
un<ler surface of the chorion to their termination near the uterine
surface of the plHcenta. The anaioniical disposition of the pk-
cental ninuses, however, is much more dilTioult of examinaiioa.
During life, and while the placenta is still attached to the ul«rus,

THS PLACENTA. 811

ihej are filled, of course, with the blood of the mother and occupy
fully one-half the entire mass of the placenta. But when the pla-
centa is detached, the maternal vessels belonging to it are torn oft'
at their necks (Fig. 227, e, c, c, c), and the sinuses, being then
emptied of blood by the compression to which the placenta is sab*
jected, are apparently obliterated; and the foetal tufls, falling to*
gether and lying in contact with each other, appear to constitute
the whole of the placental mass. The existence of the placental
sinnses, however, and their true extent, may be satisfactorily de-
monstrated in the following manner.

If we take the uterus of a woman who has died undelivered at
the fall term or thereabout, and open it in such a way as to avoid
wounding the placenta, this organ will be seen remaining attached
to the nterine surface, with all its vascular connections complete.
Let the foetus now be removed by dividing the umbilical cord, and
the uterus, with the placenta attached, placed under water, with its
internal surface uppermost. If the end of a blowpipe be now
introduced into one of the divided vessels of the uterine walls, and
air forced in by gentle insufflation, we can easily inflate, first, the
venous sinuses of the uterus itself, and next, the deeper portions
of the placenta ; and lastly, the bubbles of air insinuate themselves
everywhere between the fcetal tufts, and appear in the most super-
ficial portions of the placenta, immediately underneath the trans-
parent ohorion (a, a, Fig. 227) ; thus showing that the placental
sinuses, which freely communicate with the uterine vessels, really
occupy the entire thickness of the placenta, and are equally exten-
sive with the tufls of the chorion. We have verified this fact in
the above manner, on four different occasions, and in the presence
of Prof^ C. R. Oilman, Dr. Geo. T. Elliot, Dr. Henry B. Sands,
Dr. T. G. Thomas, Dr. T. C. Finnell, and various other medical
gentlemen of New York.

If the placenta be now detached and examined separately, it will
be found to present upon its uterine surface a number of openings
which are extremely oblique in their position, and which are
accordingly bounded on one side by a very thin, projecting, cres-
centic edge. These are the orifices of the uterine vessels, passing
into the placenta and torn off at their necks, as above described ;
and by carefully following them with the probe and scissors, they
are found to lead at once into extensive empty cavities (the pla-
cental sinuses), situated between the foetal tufls. We have already
shown that these cavities are filled during life with the maternal

619

TH» PLACEyTA.

blood; and there ia every reason to believe tbal before delivery,
nod while the circulation is going on, the placenta is at least twice
as large as &her it has been dotachcd and expelled from the uteraa.

The placenta, accordingly, is a double organ, formed partly by
the chorion and partly by the decidua; and consisting of maternal
and (octal bloodvcKiels, inextricably entangletl and united with each
other.

The part which this organ takes in the development of the fcetus
is an exceedingly important one. From the date of its forroatioo,
nt about the beginning of the fourth month, it ooustitutes tbe only
channel through which nourishment is conveyed from the mother
to the foctua. The nutritious materials, which circulate in abun-
dance in the blood of the maternal sinuses, pass through the inter-
vening membrane by endosmosis, and enter the blood of the foetus.
The healthy or injnrioutit regimen, to which the mother is subjected,
will accordingly exert an almost immediate influence upon the
child. Even medicinal substances, taken by the mother and ab-
sorbed into her circulation, may readily transude through the pla-
cental vessels 1 and they have been known in this way to exert a
apecifio eflfect upon the fcetal organization.

Tho placenta ia, furthermore, an organ of exhalation as well as
of absorption. The excrementitious substances, produced jn the
circulation of the fcetus, are undoubtedly in great measure disposed
of by transudation through the walls of the placental vessels, to be
afterward discharged by the excretory organs of the mother. The
fiystcm of tho mother may therefore be ailcctcd in this manner by
influences derived from tbe fcetus. It has been remarked more
than once, in the lower animals, that when the female has two suc-
cessive litters of young by diflbrcnt rnalca, tho young of the aecond
litter will sometimes bear marks resembling those of tbe Grst male.
In these instances, tho peculiar influence which produces the ex-
ternal mark must have been transraitteil by the first male directly
to the fuetus, from the fuetus to the mother, and from the mother to
the foetus of the second litter.

It \a a\iiO through the placental circulation tliat those disturbing
effects are produced upon the nutrition of the fcetus, which result
from sudden shocks or injuries inflicted upon the mother. There is
iiowliitio ruotn furdoubt that various deformities and deficiencies of
the fcetus, conformably to tho popular belief, do really originate, in
certain cases, from nervous impressions, such as disgust, fear or anger,
experienced by tbe mother. The mode in which these eiTccta may

THR PLACENTA. 618

be produced is readily understood from what baa been said above
of tbe anatomy and functions of tbe placenta. We know very well
how easily nervous impressions will disturb the circulation in tbe
brain, the face, the lungs, &c. ; and the uterine circulation is quite
BB readily influenced by similar causes, as physicians see every day
in cases of amenorrhoea, meoorrhagia, &c. If a nervous shock may
excite premature contraction in the muscular fibres of the pregnant
uterus and produce abortion, as not nnfrequently happens, it is cer-
tainly capable of disturbing the course of the circulation through
the same organ. But the fcetal circulation is dependent, to a great
extent, on the maternal. Since the two sets of vessels are so closely
entwined in the placenta, and since the foetal blood has here much
tbe same relation to tbe maternal, that.the blood in the pnlmonary
capillaries has to the air in tbe air-vesicles, it will be liable to de-
rangement from similar causes. If the circulation of air through
the pulmonary tubes and vesicles be suspended, that of the blood
through the capillaries is disturbed also. In the same way, what-
ever arrests or disturbs the circulation through the vessels of the
maternal uterus must necessarily be liable to interfere with that
in the foetal capillaries forming part of the placenta. And lastly,
as the nutrition of the foetus is provided for wholly by the placenta,
it will of course suffer immediately from any such disturbanoe of
the placental circulation. These effects may be manifested either
in the general atrophy and death of the fcetus; or, if the disturbing
cause be slight, in the atrophy or imperfect development of par-
ticular parts; just as, in the adult, a morbid cause operating through
the entire system, may be first or even exclusively manifested in
some particular organ, which is more sensitive to its influence than
other parts.

The placenta must accordingly be regarded as an organ which
performs, daring intra-uterine life, oflices similar to thoae of the
lungs and the intestine after birth. It absorbs nourishment, reno-
vates the blood, and discharges by exhalation various excrementi*
tious matters, which originate in the processes of foetal nutrition.

614

DI8CHABOB 07 THE OTCU.

CHAPTER xni.

DISnHARGK OF THE OVUM, AND RKTROGRAUE
IJEVKLOl'MKNT (INVOLUTION) OF TUB UTEBUS.

Fig. 228.

During tbe growth of the ovum and the formntion of the pis-
cental structures, the muscular substance of the uterus aliH) increases
in thickness, while the whole organ enlarges, in order to accommo-
date the growing fcetus and its appendages. The relative poaitiona
of the aniniun and chorJun, furlhenuore, undergo a change during
the latter periods of gestation, and the umbilical oord beoomes
developed, at the some time, in the loUowing manner.

In the earlier periods of fcetal life the umbilical cord consists
simply of that portion of the allantois lying next the abdomen. It
is then very short, and contains the umbilical vessels running in a
nearly straight course, and parallel with each other, from the abdo-
men of the fcetus to the external portions of the chorion. At this
lime the amnion closely invests the body of the foetus, so that the

size of its cavity is but little larger
than that of the fcetus. (Fig. 228.)
T!ie space between the amnion
and the chorion is then occupied
by an amorphous gelatinous ma-
terial, in which lies imbedded the
umbilical vesicle.

Afterward, however, the am-
nion enlarges faster than the cho-
rion, and encroaches upon the
layer of gclntinous mattur situated
between the two (Fig. 229), at
ruLi ill lb. nnt the same time that an albuminoos
s-Amoi-ii.. a. fluid, the "amniotic fluid," is el-
uded into its cavity, in constantly
increasing quantity. Subsequently, the gelatinous layer, above do-
acrtbed, altogether disappears, and the amnion, at about the begin-

■ cmK Ul I. ■ Kbntll tllU

Ctiorlaa.

BffliAROKHEWT OF TBB AMNIO*r.

615

lit H x« ovt'N A\ fnd Gt third niiitih; hbuujug
«iitibr|^in«(Bt of Amiilaa.

ning of the Cidh moDth, comea in contact with the internal surrace

of Che chorioD. Finnlly, toward the end of gestation, the contact

becomes so close between these

two membranes that they are '"''' """"■

partially adherent to each

other, and it requires a little

care to separate them without

laceration.

I'hequantity of the amniotic
fluid continues to iticreaaedar
ing the latter period of gesta*
tion in order lo accommodate
the movements of the fuetu?.
These movements begin to be
perceptible about the fifth
month, at which time the
mnscular system has already
attained a considerable degree of development, but become after-
ward more frequent and more strongly pronounced. The space
and freedom requisite for these movements are provided for by the
fluid accumulated in the cavity of the amnion.

The utubilical cord elongates, at the same time, in proportion to
the increasing size of the amniotic cavity. During its growth, it
becomes spirally twisted from right to left, the two umbilical arte-
ries winding round the vein in the same direction. The gelatinous
matter, already described as existing between the amnion and
chorion, while it disajipears elsewhere, accumulates in the cord in
conaidernblc quantity, covering the vessels with a thick, elastic en-
velope, which protects them from injury and prevents their being
accidentally compressed or obliterated. The whole is covered by a
portion of the amnion, which is connected at one extremity with the
integument of the abdomen, and invests the whole of the cord with
a continuous sheath, like the finger of a glove. (Fig. 280.)

The cord aim contains, for a certain period, the pedicle or stem
of the umbilical vesicle. The situation of this vesicle, it will he
recollected, is always between lliu chorion and the amnion. Its
pedicle gradually elongates with the growth of the umbilical cord;
and the vesicle itself, which generally diflappcars soon after the
third month, sometimes remaina as late as the fifth, sixth, or seventh.
Ikocording to I'rof. Mayer, of Bonn, it may even be found, by care-
il search, at Che termination of pregnancy. When discovered in

DtSCHAROB 07 THE OTUV.

the midflte ami latter periodii of gestatioo, it presents itself aa &
small, flattened, and sbrivcllcd vesicle, situnt«d underneath the
amnioij, at a variable distance from the insertion of the uinbilic&l
cord. A minute bloodvessel is often seen running to it from the
cord, and ramifying upon its aurfncc.

Fig. 230.

OKAriDnDHAK rTBacaABnCeiTiii'T*, tbvvlac (be i*l«tl<iu oflhaearJ, pknclk. i
bruics. Ac., atKiut Ihe (ud oTtliii MTcath iDiBiilh, — I U*cl<lii* **r*. 9 D«dil«a raflaxa. 3. Ck«n«*.
i. AoidIud.

The decidua reflexa, during the latter months of pregnancy, U
constantly distended and pushed back by the increasing size of the
egg; so that it is finally pressed closely against the opposite sarface
of the decidua vera, which still lines the greater port of the uterine
cavity. By the end of the seventh month, the opposite surfaces
of the decidua vera and refleica are in complete contact with each
other, though still distinct aud capable of being separated without
difl\cuUy. After that time^ they fuae together and beooroe coa-
founded with each other: the two at lost forming only a SiDglc,
thin, friable, Rcmi-oparjuc layer, in which no trace of their original
glandular structure can be discovered.

This is the condition of things at the terminatioQ of pregnancy.
Then, the tin^e having arrived for parturition to take plac«, the
hypertrophied muscular walls of the uterus contract forcibly upon
its contents, and the egg is discharged, together with the whole of
the decidual oterine mucous membrano.

la the human subject, as well as in most quadrupeds, the meat*

SEPARATION OF THl PLACBKTA. 617

branea of the egg are aaaally raptured during the process of par-
tarition ; and the fcetus escapes first, the placenta and the rest of
the appendages following a fev moments afterward. Occasionally,
however, even in the human subject, the egg is discharged entire,
and the fcetus liberated afterward by the laceration of the mem-
branes. In each case, however, the mode of separation and expul-
sion is, in all important particulars, the same.

The process of parturition, therefore, consists easentially in a
separation of the decidual membrane, which, on being dischargod,
brings away the ovam with it The greater part of the decidua
vera, having fallen into a state of atrophy during the latter months
of pregnancy, is by this time nearly destitute of vessels, and sepa-
rates, accordingly, without any perceptible hemorrhage. That por-
tion, however, which enters into the formation of the placenta, is,
on the contrary, excessively vascular; and when the placenta is
separated, and its maternal vessels torn off at their necks, as before
mentioned, a gush of blood takes place, which accompanies or
immediately follows the birth of the foetus. This hemorrhage,
which occurs as a natural phenomenon at the time of parturition,
does not come from the uterine vessels proper. It consists of the
blood which was contained in the placental sinuses, and which is
expelled from them owing to the compression of the placenta by
the walls of the uterus. Since the whole amount of blood thus
lost was previously employed in the placental circulation, and since
the placenta itself is thrown off at the same time, no unpleasant
efiect is produced upon the mother by such a hemorrhage, because
the natural proportion of blood in the rest of the maternal system
ramAins the same. Uterine hemorrhage at the time of parturition,
therefore, becomes injurious only when it continues after complete
separation of the placenta; in which case it is supplied by the
moatbs of the uterine vessels themselves, led open by failure of the
uterine oontractions. These vessels are usually instantly closed,
after separation of the placenta, by the contraction of the muscular
fibres of the uterus. They pass, as we have already mentioned, in
an exceedingly oblique direction, from the uterine surface to the
placenta ; and the muscular fibres, which cross them transversely
above and below, necessarily constrict them, and effectually close
their orifices, immediately on being thrown into a state of contraction.

Another very remarkable phenomenon, connected with preg-
nancy and parturition, is the appearance in the uterus of a new
mucous membrane, growing underneath the old, and ready to
take the place of the latter afler its discharge.

618

[AROB 01

ir the internal surrace of the body of the uterus be examint
immediately after parturition, it will be seen that at the spot where
the placenta was ntlached every trace of inucoos membrane ha»
disappeared. The muscular Cbres of the uterus are here perfectly
exposed and bare ; while the moutha of the ruptured uterine sinose*
arc also visible, with their thin, ragged edges hanging into the
cavity of the uterus, and their onilceB plugged with more or leis
abundant bloody coagula.

Over the rest of the uterine surface, the dectdua vera has also
disappeared. Here, however, notwithstanding tlic loss of the ori-
ginal mucous membrane, the musculflr fibres are not perfectly bare,
but are covered with a thin, acmi.tranaparcnt l!1m, of a whitish color
and soft consistency. This film is an imperfect mucous membrane
of new formation, which begins to be produced, underneath the
old deuidua vera, as early as the beginning of the eighth month.
We have seen this new mucous membrane very distinctly in the
uterus of a woman who died undelivered at the above period.
The old mucous membraue, or decidua vera, is at this time some-
what opaque, and of a slightly yellowish color, owing to a partial
fatty degeneration which it undergoes in the latter months of preg-
nancy. It is easily raised and separated from the subjacent parts,
owing to the atruphy of its vascular connections; and the new
muQOQS membrane, situated beneath it, ia readily distinguished by
its fresh color, and healthy, transparent aspect.

The mucous membrane of the cervix uteri, which takes no part
iu the formation of the decidua, ia not thrown off in parturition,
but remains in its natural position; and after delivery it may be
seen to terminate at the os internum by an uneven, lacerated edge,
where it was formerly continuous with the decidua vera.

Subsequently, a regeneration of the mucous membrane lakes place
over the whole extent of the body of the uterus. The mucous
membrane of new formation, which is already in existence at the
time of delivery, becomes thickened and vascular; and glandntar
tubules nrc gradually developed in its subittance. Al the end of
two months after delivery, according to Ueschl' and Longet,' it hu
entirely regained the natural structure of the uterine mucous mem-
brane. It unites at the os internum, by a linear cicatrix, with the
mucous membrane of the cervix, and the traces of its lacerotion at
this spot afterward cease to be visible. At the point, however,

' ZvilKlirin ilvr K. K. GfflAMiuliari H«t Aent», In Wlen, IMS.

■ TnUi do Pli/sli>logi.ii. Ot la U6i)Cr«tinn, p. 173.

BETBOGRADE DXVBLOPHBN'T OF THB UTERUS. 610

where the placenta was attached, the regeneration of the mucous
membrane is leas rapid ; and a cicatrix-Iike spot ia otten visible at
this situation for several months after delivery.

The only further change, which remains to be described in this
connection, is the fatty degeneration and reconstruction uf the
muscular substance of the uteru.«. This process, which is some-
times known as the "invo-

Fig. 231.

lation*' of the uterus, takes
place in the following man-
ner. The muscular fibres
of the unimpregnated uterus
■re pale, flattened, spindle-
shaped bodies (Fig. 231) near-
ly homogeneous in structure
or very faintly granular, and
measuring from ,io to 3^,
of an inch in length, by

in width. Dnring gestation
these fibres increase very
considerably in size. Their
texture becomes much more
distinctly granular, and their
ODtlines more strongly mark-
ed. An oval nucleus also
shows itself in the central
part of each fibre. The en-
tire walls of the uterus, at the
time of delivery, are com-
posed of such muscular fibres
as these, arranged in circu-
lar, oblique, and longitudinal
bundles.

About the end of the first
week after delivery, these
fibres begin to undergo a
fatty degeneration. (Fig.
2S2.) Their granules be-
come larger and more pro-
minent, and very soon as- «"'^''«-'" *•,■'"''•-'"■'-*" i;"-y. '«

sume the appearance of mole- ix»i r<T<T.

Ur*rrLitR Tibikii or tI.ii«pai<iiriTsi»
UTNari; rtom ■ irain>a Bivd 40, dawl of phthUU
palmoBtklU.

Pig. 232.

620

DI8CHABOS OF THE OTUK.

Fig. 233.

cules of fat, deposited in the substanoe of the fibre. The &ttj
deposit, thus commenced, increases in abandance, and the mole-
cules continue to enlarge until they become converted into fully
formed oil-globules, which fill the interior of the fibre more or leas

completely, and mask, to a
certain extent, its anatomical
characters. (Fig. 2SS.) The
universal fatty degeneration,
thus induced, gives to the
uterus a softer consistency,
and a pale yellowish color
which is characteristic of it
at this period. The maaca-
lar fibres which have become
altered by the fatty deposit
are afterward gradually ab-
sorbed and disappear; their
place being subsequently
taken by other fibres of new
HtracuLA> FiB«B» or hitmab dtirdi, tbna formation, which already be-

wmIei ftTlat pftrturitian ; from • vonta d«id of pari- i i ■

loDitiK. gi n to make their appearance

before the old ones have been
completely destroyed. As this process goes on, it results finally
in a complete renovation of the muscular substance of the uterus.
The organ becomes again reduced in size, compact in tissue, and
of a pale ruddy hue, as in the ordinary unimpregnated condition.
This entire renewal or reconstruction of the uterus is completed,
according to HescbU about the end of the second month aiWr
delivery.

' Op. cit.

DEVELOPMENT OF THE EMBRYO.

CHAPTER XIV.

DEVEI,OPME>?T OF THK KMBRYO— NERVOUS SYSTEM,
OUGAN'8 OF SEN'8K, SKELETON, AND LlUDti.

Fig. 2$4.

Tbb Rrat trace of a spinal cord in the embryo consists of the
double longitudinal foM .or ridge of the blastodermic membrane,
which shows itself at an early period, aa above described, on each
aide the median furrow. The two lamlDos of which this ia com-
posed, on the right and left sidea (Fig. 234, a, &), unite with each
other in front, forming a rounded diUtation (e),
the cephalic extremity, and behind at rf, forming
a pointed or caudal extremity. Near the poe-
lerior extremity, there is a smaller dilatation,
which marks the future situation of the lumbar
enlargement of the spinal cord.

As the laminse above described grow upward
and backward, they unite with each other upon
the median line, so that the whole is converted
into a hollow cylindrical cord, terminating ante-
riorly by a bulbous enlargement, and posteriorly
by a pointed enlargement; the central cavity
which it contains running continuous^ through
it, from front to rear.

The next change which shows itself is a divi-
sion of the anterior bulbous enlargement into
three secondary compartmentit or vesicles (Fig.
2it5), which are partially separated from each other by transverse
constrictions. These vesicles are known as the ikret cerebral vesi-
cles, from which all the different parts of the encephalou arc after-
ward to be developed. The first, or most anterior cerebral vesicle
is destined to form the homisphuros; the second, or middle, the
tubercula quailrigemina; and the third, or posterior, the medulla
oblongata. All three vesicles are at this time hollow, and their

Fcmallus «r Ciiac-
n>ci-Sriii>L All*.—
'1, t. Il|i4aal tori. «: Co-
pbnllc eslMmlly. iL
Caudkl «NtMHtl7.

622

DBVELOPMBNT OP TUB EMBRYO.

Tig. 235.

CAvilies communicate freely with each otbcr, ihrougli the intenren-
ing consiriciions.

Very soon tlie anterior and the posterior oerel>ral vesicles suffer.]
a further division; the middlo one remain-
ing uD<livi(leO. The anterior vehicle ihu:*
separates into two portions, of which the
lirst, or lurger, ci>iistitutes the hemisphereo,
while the second, or smaller, beconnes Uie
optic thnlami. The third vesicle alsoacpa*
rates into two portions, of which the ante*
rior becomes the cerebellum, and the pos-
terior the medulla oblongata.

There are, therefore, at this time five
cerebral vesicles, all of whose cavities coro-
muuicate with each other and with thu
central cavity of the spinal cord. The
entire cerebro-spinal axis, at the same time,
becomes very strongly curved in an ante-
rior direction, corresponding with the ante-
rior curvature of the body of the embryo
(Fig. 28(i); so that the middle vesicle, or
that of the tubercuU quadrigemina, occa-
pies a prominent angle at the upper part uf
the encephalon, while the hemispheres and the medulla oblongata
are situated below it, anteriorly and posteriorly.

At iirst, it will be ub&urved, the relative size of the various parts
of the encephalon is very different from that which
they afkerward attain in the adult condition. The
hemispheres, for example, are hardly larger than
the tuberculii qnadrigcniina; and the cerebellum
is very much inlurior iti size to the medulla oblon- 1
gala. Soon afterward, the relntiveposilion and size
of the parts begin to alter. Thu hemispheres and
tubercuU quadrigemina grow faster thart the post^-
rior porliousof the encephalon ; and the cerebellam
bec«>incs doubled backward over the medulla oblon-
gata. (Fig. 287.) Subsequently, the hemispheres
rapidly enlarge, growing upward and backward,
so us to cover in and conceal both the optic tha-
larni and the tubercula quadrigemina {Kig, 2'AS); the cerebellum
tending in the same way to grow backward, and projecting farther

rarnMlUn vf lh« C»B«Ka.
Kri:iAi. Ask— I. Vi«<cl« or

llifi hp(nl*|>h»n'.. J. Vnidl* uf
th'i lab*fciilM •(iwdtlKMniiiB n.
Vrrlel«#rUifltDe4iiiUBlili>BgkiK.

Fig. 23«.

•IfhlliD Oif BB Inch
Iwng, •Iipiwlni Kwiln
■ nU *|>lii>l ciird, — I,
H'-n)t>[ihrr», S. Tn-
liercnlm iiTiadriinml-
■>• S. CnrvbrnaiD.
i. tMulIm ublinplt.

NERVOUS SrSTBU.

«23

and farther over the medulla oblongata. The subsequent history
of the development of the encephalon is little more than a. cod-

Fl(r. 237.

Pig. 23fl.

PaTAi. Fi«, «n* Bnil • ^ii«n«r lii«b
iMif.— I. U#nMph«rek S. TulwnulB

h*l( Incben Icmi— I, H«nUiilier>a«. S.
Cecehi^llan 1. MedulU oblaupla.

ttDuatioD of the surne process; the relative dimenstuna of the purta
constantly changing, so that the hemispheres become, in. the adult
coodition (Fig. 289), the largest of all the diviaions of the ence-

Fig. 239.

BbIIII op AurLT I'lit. — I. tli*(CLl>|il»r«B, 3. Orcbvllam. 4 MihIuIIi, Ablo«f jW.

phalun. while the cerebellurn i* next in size, ami covers entirely
the upper portion of the medulla oblongata. The Burfwces, also, of
the hemiephorcs nnd cerebellum, which were at Urst smooth, become
afterward convoluted; increasing, in ihifl way, still farther the
extent of their nervotu matter. In the human foetus, these con-
volutions begin to appear about the beginning of the fifth month
(Looget), and grow couHtJintly deeper and more abundant during
the remainder of fecial life.

The lateral portions of the brain growing at the same time more
rapidly than that which is situated en the median line, they soon
pnijcct un each bide outward and upward; and, by folilitig over
Against each other in the median line, form the right and left hemi-
spheres, separated from each other by the longtltuiiual fiasure.

624

DBTKLOPMENT OP TUB KlCBRrO.

A similar process of growth taking place in the spinal cord renin
ia the formation of the two lateral columns and the anterior and pw
teriur median Ussureaof thecord. Elsewhere the mediaD fiifturei»
less complete, as, for example, between the two lateral halves oftbt
cerebellum, the two oplic ihalami and corpora striata, ami the Ivi
tubercula quadrigcmina; but it exists everywhere, and marics more
or less distinctly the division between the two sides of the nerfoo*
centres, produced hy the exuessiTO growth of their lateral portioca.
In this way the whole cerebro-spinal axis is converted into a doable
organ, equally developed upon the Hght and led aides;, and partially
divided by a longitudinal median Aitsurc.

Organs 0/ Special &n«. — The eyes are fonned by a divertiooloin
which grows out on each side from the 6rst cerebral vesicle. Tbii
diverticulum is at first hollow, its cavity communicating with ihu
of the hemisphere. Afterward, the passage between the two is filkd
up with a deposit of nervous matter, aud becomes the optic nem.
The globular portion of the diverticolam, which is converted iob
the globe of the eye, has a very thin layer of nervous matter dq»-
sited upon its internal surface, which becomes the retina ; the rea
of its cavity being occupied by a gelatinous eemt^fluid siibstaoce,
the viireom hod>j. The crystalline lens is formed in a distinct fol-
ILcLe, which is an offshoot of the integument, and becotuca partially
imbetSded in the anterior portion of the globe of the eye. The
cornea also is originuUy a part of the iotegumeni, and remaiu
partially opaque until a very late period of development. Its tusos
clears up, however, and becomes perfectly transparent, shortly bo-
fore birth.

The iris is a muscular septum which is formed in front of l^
crystalline lens, separating the anterior and posterior chambeaof
the aqueous humor. Its central opening, which afterward
the pupil, is at &rat closed by a vascular membrane, the j»ii;h'
membrane, passing directly across the axis of the eye. The
of this membrane, which arc derived from those of the iria^ snta^-
queiitly become atrophied. They disappear 6rst from its ceoint
and afterward recede gradually toward its circumference; retantu^
always upon themselves iu loops, tfaecon vexities of which are diractid
towani the centre of the membrane. The pupillary membrane itself
Anally becomes atropbietl and destroyed, following in this r«<iD*
grade process the direction of its rece<ling bloodvessels, viz., froa
the centre toward the circumference. It has completely disappeuvl
by tiie end of the seventh month, (Cruveilhier.)

8KELET0K AVD LIHBS. 625

The eyelids are formed by folds of the integament, which
gradually project from above and belov the situation of the eye-
ball. They grow so rapidly during the second and third months
that their free margins come in contact and adhere together, so that
they cannot be separated at that time without some degree of vio-
lence. They remain adherent from this period until this seventh
month (Guy), when their margins separate and they become per-
fectly free and movable. In the carnivorons animals, however
(dogs and oats), the eyelids do not separate from each other until
eight or ten days after birth.

The internal ear is formed in a somewhat similar manner with
the eyeball, by an of&hoot from the third cerebral vesicle; the
passage between them filling ap by a deposit of white substance,
which becomes the auditory nerve. The tympanum and auditory
meatDS are both oflshoots from the external integument.

Skeleton. — At a very early period of development there appears,
as we have already described (Chap. YII.), immediately beneath the
cerebro-spinal axis, a cylindrical cord, of a soft, cartilaginous con-
sistency, termed the cJtorda dortalis. It consists of a fibrous sheath
containing a mass of simple cells, closely packed together and
united by adhesive material. This cord is not intended to be a
permanent part of the skeleton, but is merely a temporary organ
destined to disappear as development proceeds.

Immediately around the chorda dorsalis there are deposited soon
afterward a number of cartilaginous plates, which encircle it in a
series of rings, corresponding in number with the bodies of the future
vertebne. These rings increase in thickness from without inward,
encroaching npon the substance of the chorda dorsalis, and finally
taking its place altogether. The thickened rings, which have been
filled up in this way and solidified by cartilaginous deposit, become
the bodies of the vertebrse; while their transverse and articulating
processes, with the laminae and spinous processes, are formed by
subsequent outgrowths from the bodies in various directions.

When the union of the dorsal plates upon the median line fails
to take place, the spinal canal remains open at that situation, and
presents the malformation known as $pina bifida. This malforma
tion may consist simply in a fissure of the spinal canal, more or
less extensive, in which case it may orten be cured, or even close
spontaneously; or it may be complicated with an imperfect deve-
lopment or complete absence of the spinal cord at the same spot,
40

026

DBVBT.OPBIBXT OF THB KlIBRTO.

wben it is accotnpaoied of course by paraljrsia of the lower ex-
iremitioB, and almost necessarily resutts in early deatb.

The entire skeleton is at first cartilaginous. The first points of
ossification show themselves about the beginning of the second
mouthy almost Bimultaoeoaaly in the clavicle and tbe upper and
lower jaw. Then come, in the following order, the long bones of
tbo extremities, the bodies and processes of the vertebne, tbe bonea
of the head, the ribs, pelvis, scapula, metacarpus and metatarsus,
and the phalanges of the fingers and toes. Tbe booes of the carpus,
however, are all cartilaginous at birtb, and do not begin to ossify
until a year afterward. The calcaneum and astragalus begin to
ossify, according to Cruveithrer, during the latter periods of footat
life, but the remainder of the tarsus is cartilaginous at birtb. The
lower extremity of the femur begins to ossify, according to the
same author, during the last half of tbe ninth month. The pisiform
boue of the carpus ts said to commence its osHification later than
any other bone in the skeleton, viz., at from twelve to fifteen years
lifter birth. Nearly all the bones ossify from several distinct points;
the ossification spreading as tbe cartilage itself increases in size,
and the various booy pieces, thus produced, uulticg with each other
at a later period, usually some time afler birth.

The limbs appear, by a kind of budding process, aa offshoots of
the external layer of the blastodermic membrane. Tbey are at
first mere rounded elevations, without any separation between the
fingers and toes, or any distinction between the Oiflereot articula-
tions. Subsequently the free extremity of each limb becomes di-
vided into the phalanges of the fingers or toes; and afterward the
articulations of the wrist and ankle, knee and cHkiw, shoulder and
liip, appear successively from below upward.

The posterior extremities, in the human subject, are less rapid in
their devetopmcnt than the anterior. Throughout the U^Tm of
foetol life, indeed, the anterior parts of the body are generally more
voluminous than the posterior. Thcyounger the embryo, the larger
are the head and upper exlremilies in proportion to the rest of tbe
body. The lower limbs and the pelvis, more particularly, are very
slightly developed in the early periods of growth, as compared with
the spinal column, to which they are attached. The inferior ex-
tremity of the spinal column, formed by the sacrum and coccyx,
prqjects at this time considerably beyond tbe {)clvia, forming a tail,
like that of the lower animals, which is curled forward toward tbo
ubdomen, and terminaicsin a pointed extremity. Subjiequently tbo

BKBLSTOK AND LIUBB. 627

pelvis and the ranscular parts seated upon it grow so much faster
than the sacram and coccyx, that the latter become concealed
under the adjoining soft parts, and the rudimentary tail accord-
ingly disappears.

The mUgume^ of the embryo is at first thin, vascular, and ex-
ceedingly transparent It afterward becomes thicker, more opaque,
and whitish in color; though even at birth it is more vascular than
in the adult condition, and the ruddy color of its abundant capil-
lary vessels is then very strongly marked. The hairs b^in to
appear about the middle of intra-uterine life; showing themselves
first upon the eyebrows, and afterward upon the scalp, trunk and
extremities. The nails are in process of formation from the third
to the fifth month ; and, according to Edlliker, are still covered
with a layer of epidermis until after the latter period. The seba-
ceous matter of the cutaneous glandules accumulates upon the skin
alter the sixth month, and forms a whitish, semisolid, oleaginous
layer, termed the vemtx eeueoaa, which is most abundant in the
flexures of the joints, between the folds of the integument, behind
the ears and upon the scalp.

The cells of the epidermis are repeatedly exfoliated after the first
five months of festal life (KoUiker), and replaced by others, of new
formation and of larger size. These exfoliated epidermic cells are
found mingled with the sebaceous matter of the vernix caseosa in
great abundance. This semi -oleaginous layer, with which the in-
tegument is covered, becomes exceedingly useful in the process of
parturition, by lubricating the surface of the body, and allowing it
to pass easily through the generative passages.

628 DBVBLOPMBST OF TBt AUMEXTABT CASAL

CHAPTEU XV.

DEVELOPMENT OP THE ALIMENTARY CAN'AL
ANll ITS APPENDAGES.

"Wk have already 3oen, in a preceding cTinpler, that the intesiipjl
cannl is formed by tbe iDternal layer of the blastodermic membrant.-.
which curves forward on each sideband la thus conrerted iotoi
nearly strntght cylindricnl tube, terminating at each exiremiiT in
ft rounded ctil-desoc, and inclosed by the external layer of thf
blastoflertnic membrane. The abdominal walls, however, do ool
QTUtc with each other upnii the median line until long after Ae
formation of the intestinal canal; so that, during a certain perioA
thc abdomen of ihe embryo is widely open in front, presenting a
long oval excavcition, in which tlie nearly stmight intestinal Latn
is to be seen, running from its anterior to its posterior extremity.

The formation of the stomach takes place in the foUowiog naii'
ner: The alimentary canal, originally straight, soon preaeots i
lateral curvntures at the iip[^>er part of the abdomen; the firrt
the left, the second to the right. The first of these curvatoi
becomes expanded into a wide sac, projecting lat«mlly^ from the
median line into the left hypocbondrium, forming the great poa
of the stomach. The second curvature, directed to the right, mari
the boundary between the stomach and the duodenum ; and
lube at that point becoming constricted and furnished with acireahr
layer of muscular fibres, is converted into the pylorus. Immedi-
ately below the pylorus, the duodenum agnin turns to the left; uk)
these curvatures, increa^^ing in number and complexity, forra the
convolutions of the sniull intestine. Tlic large intestine forms •
spirfti curvature; ascending on the right side, then croasiDg OW'
to the left aa the transverse colon, and again descending on the Wft
eide, to terminate by the sigmoid flexure in the rectum.

The curvatures of the intestinal cnnal take place, however, io in
BDtero-pusterior, as well as in a lateral direction, and may be \»*
studied in n profile view, as in Fig. 340. The abdominal walUare

the

.1.. ■

AND ITS APPSNDAGE8.

629

liere 8til! imperfecily closed, leaving n wide opening at a 6, where
the integuraenl oF the fceius becomes contmiious with the com-
inenceinent of the Amniotic membrane. The intestine makes at

VlMtjnX. t. I'rlnaTjr MiuMrr /. AlUutnl*- g. L'joUllcal loiolo. «. UulUd lIUC. >l>«w1«( Ui«

6rHt a single angular turn forward, and opposite the mo3t promi-
nent portion of this angle is to be seen the obliterated duct, which
forms the stem of the umbilical vesicle. A short distance below
this point the intestine subsequently eolarges in its calibre, and the
situation of this enlargement marks the comrTkenccment of the
colon. The two portions of the intestine, after this period, become
widely different from each other. The upper portion, whicii is the
small intesLiue, grows mostly in the direction of its length, and
becomes n very long, narrow, and convoliiteil lube; while the lower
jKiriion, which is the largo intestine, increases rapiJly in diameter,
but elongates less than the former.

At the point of junction of the small and large intestines, a late*
ral bulging or diverticulum of the latter shows itself, and increases
in extent, until the ileum seems at last to be inserted obliquely into
the side of the colon. This diverticulum of the colon is at first
ttniformly tapering or conical in shape; but afterward that portion
which forms ila free extremity, becomes narrow and elongated, and
is slightly twisted upon iiself in a spiral directiuii, funning the
appendix vermiformis; while the remaining portion, which is con-
tinuous with the intestine, becomesexeeedingly enlarged, and forms
the caput coli.

The caput coli and the appendix are at first situated near the

630

DEVKLOPMEXT OF THE ALIMENTARY CANAL

umbilicus; but bctveen the fourth and fifth moTiths (CraveUbicri
their posiltoii is ulterec), and they thea become fixed in the rigiit
iliac region. Dariag the firet six months, the inlemal sar&ceof
the small intestine is smooth. Ac the seventh month, scoordh^cn
Gmveilhier, the valvuloc connirentes begin to appear, afler vbich
they increase in size till birth. The division of the colon IMj
sacctili by loDgittidioal and trnn^verse bands, is also an appeartooe
which preheats itself only during tha laat half of foetal life. Pn-
vious to that time, the colon is smooth atul cylindrical in figut^j
like tho small intestine.

Aflcr the small intestine is once formed, it increases very nindlv
in length. It grovra, indeed, at this time, faster than the walls ofj
the ubilumen; m that it uuu no longer be contained in the abdomi'
nal cavity, but protrudes, onder the form of an intestinal loop, or
hernia, from the nmbilical opening. In the human embryo, ihUfl
protrusion of ihu intoatino can be readily seen during the latter pirt ™
of the second month. At a subseqaeut period, however, the walU
of the abflomen grow more rapidly than the intestine. TbeyH-
cordingly gradually envelop the hernial protrusion, and at hit
inclose it again in the cavity of the abdomen, .

Owing to an imperfect development of the abdominal walls, agj J
an imperfect closure of the umbilicus, this intestinal proCnukn^
wliiub is normal during the early stages of fwlal life, sometinRfB
remains at birth, and we then have a congenital umbifieai hmia.
As the parts at that time, however, have a natural tendency li
cicatrize and unite with each other, simple pressure is geoenlly
effectual, in such cases, in retaining the hernia within the abdoawa, '
and ill producing at last a complete cure. fl

Urinary Bladder, Ureihra, &c. — It will be reoollected that vtfv^
soon after tho formation of the intestine, a vascular outgrowth tskc»
place from its posterior portion, which gradually protrudes fn*iD Ibe
open waits of the abdomen in front, until it comes in contact witit
the external investing membrane of the egg, and forms, by its oitt
tinned growth and expansion, the allantcis. (Fig. 240,/.) It is »i
first, as we have shown above, a hollow sac; but, as it spreads om
over the surface of the investing membrane of the egg* its two
opposite walls adhere to each other, so that its cavity is oblitenied
at this situation, and it is thua converted into a single Tascalsr
membrane, the chorion. This obliteration of the cavity of ibc
allantots commences at its external portion, and gradually extend*
inward toward the point of its einergenue from thts abdomen. Tbt

AND ITS APPENDAGES. 6Sl

bollow tabe, or dact, which <x>QDect8 the cavity of the allantois with
the posterior part of the intestine, is accordingly converted, as the
process of obliteration proceeds, into a solid, rounded cord. This
cord is termed the vrcuhus.

After the walla of the abdomen have come in contact, and anited
with each other at the umbilicus, that portion of the above duct
which is left outside the abdominal cavity, forms a part of the um-
bilical cord, and remains connected with the umbilical arteries and
vein. That portion, on the contrary, which is included in the ab-
domen, does not close completely, but remains as a pointed fusiform
sac, terminating near the umbilicus in the solid cord of the urachus,
and still communicating at its base with the lower extremity of the
intestinal canal. This fusiform snc (Fig. 240, e), becomes the uri-
nary bladder; and in the fcBtus at term, the bladder is still conical
in form, its pointed extremity being attached, by means of the ura
chns, to the internal surface of the abdominal walls at the situation
of the umbilicus. Afterward, the bladder loses this conical form,
and its fundus in the adult becomes rounded and bulging.

The urinary bladder, as it appears from the above description, at
first communicates freely with the intestinal cavity. The intestine,
in fact, terminates, at this time, in a wide passage, or cloaca, at its
lower extremity, which serves as a common outlet for the urinary
and intestinal passages. Subsequently, however, a horizontal par-
tition makes its appearance just above the point of junction between
the bladder and rectum, and grows downward and forward in such
a manner as to divide the above-mentioned cloaca into two parallel
and unequal passages. The anterior or smaller of these passages
becomes the urethra, the posterior or larger becomes the rectum ;
and the lower edge of the septum between them becomes finally
united with the skin, forming, at its most superficial part, a tole-
rably wide band of integument, the pertiteum^ which intervenes
between the anus and the external portion of the urethra.

The contaUa of ike inleslme, which accumulate during foetal life,
vary in different parte of the alimentary canal. In the small intes-
tine they are semifluid or gelatinous in consistency, of a light
yellowish or grayish-white color in the duodenum, becoming yellow,
reddish-brown and greenish -brown below. In the large intestine
they are of a dark greenish hue, and pasty in consistency; and the
contents of this portion of the alimentary canal have received the
name of meconium, from their resemblance to inspissated poppy-
juiue. The meconium contains a krge quantity of fat, as well as

S82

OSVELOPMENT OP THE ALlMEltTABY CAXAL

various insoluble substances, probably the residue of epithelial uA
tnncous accumulations. It does not contain, however, any trace of
the biliary subBtuDties(taurocbulatesand gtyko oholBtes) when can-
fully examined by Pettenkofer^a test; and cannot therefore properly
be regartlwl, as is sometimes incorrectly asserted, as resulting from
the accumulation of bile. Tn the contents of the small inte«tine,OB
the contrary, traces of bile may be found, according lo Lebinana,'
so early as between the fifVb and sixth months. \Vc have iha
found distinct traces of bile in the small intestine at birth, butiiii
even then in extremely small quantity, and is somclimca altogetbw
absent.

The meuonium, therefore, and the intestinal contents generalljr,
are not compoRett principally, or even lo any appreciable extent, of
ilie secretions of the liver. They appear rather to be prodaoH by
the mucous membrane of the intestine itifelf. Even their yellowiib
nnd greenish color doea not depend on the presence of bile^ Btaoe ■
the yellow color first shows itself, in very young foetaaes, abomfl
the middle of the small inieallne, and not at if* np]»cr extremity-"
The material which accumulates aAerward appears lo extend fron
this point upward and downward, gradually filling' the intestine,
and becoming, in the ileum and large inLestioc, darker aud mure
pasty as gestation advances.

It is a singular fact, perhaps of some importance in this connec-
tion, that the amniotic fluid, during the latter half of foatal lifr,
finds its way, in greater or less abuudance, into the stomach, ind J
through that into the intestinal canal. Small cheeay-luoking mismfl
may sometimes be found at birth in the fluid coniainod in the
."itomach, which arc seen on microscopic examination to be nooilur
than portions of the vernix caseosa exfoliated from the skin iatii
the amniotic cavity, and afterward swallowed. Acoording to Kol>
liker,* the soEl downy haint of the ftotus, cxfuliaiod from the skin,
are often swallowed in the same way, and mav be found in ihi!
meconium.

The gastric Juici is not secreted before birth; the contents of
stomach being generally in small quantity, clear, nearly oolorj
and neutral or alkaline in reaction.

The liver is developed at a very early period. Its size in p
portion to that of the entire body is, in fact, very much grenterin
the early mouthn than at birth or in the adult condition. In tin

' Phjaiologto&l Clixmintrjr, Phlln'lt^Iplitii •NlitJOD,
■ Q»tceb«lt)hrt. Uiiuig. 1^52, p. 139,

Toi. i. p. *3a.

AXD ITS AFPEyDAQES. 888

foetal pig we have funnd the relative size of the liver greateftt
withJD the first month, when it amounts to very nearly 12 per cent.
of the entire weight of the body. Afterward, as it grows less rapidly
than other parts, its relative weight diminishes successively to lU
per cent, and 6 per cent ; and is reduced before birth to 3 or 4 per
cent In the human subject, also, the weight of the liver at birth
is between S and 4 per cent, of that of the entire body.

The secretion of bile takes place, as we have intimated above,
during foetal life, in a very scanty manner. We have found it, in
minute quantity, in the gall-bladder as well as in the small intes-
tine at birth ; but it does not probably take any active part in the
nutritive or other functions of the foetus before that period.

The glycogenic function of the liver commences during foetal life,
and at birth the tissue of the organ is abundantly saccharine. It is
remarkable, however, that in the early periods of gestation sugar is
produced in the foetus from other sources than the liver. In very
young foetuses of the pig, for example, both the allantoic and
amniotic fluids are saccharine, a considerable time before any sugar
makes its appearance in the tissue of the liver. Even the urine, in
half-grown foetal pigs, contains an appreciable quantity of sugar,
and the young animal is therefore, at this period, in a diabetic con-
dition. This sugar, however, disappears from the urine before birth,
and also from the amniotic fluid, as haa been ascertained by M. Ber-
nard ;* while the liver begins to produce a saccharine substance, and
to exercise the glycogenic function, which it continues after birth.

Development of the Pharynx^ (Esophagus, &c. — We have already
seen that the intestinal canal consists at first of a cylindrical tube,
terminated, at each extremity of the abdominal cavity, by a rounded
cul-de-sac (Fig. 240, c, c); and that the openings of the mouth and
anus are subsequently formed by perforations which take place
through the integument and the intervening tissues, and so estab-
lish a communication with the intestinal tube. The formation of
the anterior perforation, and its appendages, takes place in the fol-
lowing manner: —

After the early development of the intestinal tube in the mode
above described, the head increases in size out of all proportion to
the remainder of the foetus, projecting as a lar^e rounded mass from
the anterior extremity of the body, and containing the brain and the
organs of special sense. This portion soon bends over toward the

' L*-9ond do I'b/siolugie Expuriuoutalv, Paris, 1856, p. 398.

6S4

nETBT.OPl

THE ALIMBXTAl

abdomen, in consequence of the incrensing curvature of tbe whole
body which takes place ot this time. In the interior of this
cephalic mass there is now fortned a large cavity i^^S' '^'^^t ^Ot ^^
the molting down and liquefaction of a portion of its substance.
This cavity is the phart/nx. It corresponds by its anterior extre-
tnity to the future situation of the mouth ; and by its posterior
portion to the upper end of the intei^tinal canal, the future situation
of the stomach. It is still, however, olofwl on all sides, and do69
not as yet communicate either with the exterior or with the cavity
of the stomach. There is, accordingly, at this time, no thorax
whatever; but the sloinach lies at tbe upper extremity of the abdo-
men, immediately beneath the lower extremity of tho pharynx, from
which it is separated by a wall of intervening tissue.

Subsequently, a perforation takes place between tbe adjacent
extremities of the pharynx and stomach, by a short narrow tube,
the situation of which is inarkcil by tliu dotted lines x, in Fig. 240,
This tube afterward lengthens by the rapid growth of that portion
of the liody in which it is contained, and becomes the cetophayta.
Neither the pharynx nor oesophagcis, therefore, are, properly speak-
ing, psrts of the intestinal canal, formed from the internal layer of
the blastoflcrmic membrane; but are, on the contrary, furinations
of the external layer, from which the entire cephalic mass is pro-
duced. Tho lining membrane of tho pharynx and cesophagus is to
be regarded, also, for the same reason, as rather a coolioualion of
the integument than of the intestinal mucous membrane; and even
in the adult, the thick, whitish, and opaque pavement epithelium
of the oesophagus may be seen to terminate abruptly, by a well-
de6ned line of demarcation, at tho cardiac orillco of the stomach;
beyond which, throughout the remainder of the 4dimeDtary canal,
the epithelium is of the columnar variety, and easily distinguish-
able by its soil, ruddy, nod transparent appearance.

As the oesophagus lengthens, the lungs are developed on each
side of it by a protrusion from the pharynx which extends and
becomes repeatedly subdivided, formitig the bronchial tubes and
their raniilicationti. At tireit, the lungs project into the upper
part of the abdominal cavity ; for there is still no distinction be-
tween the chest and abdomen. Afterward, a horizontal partition
begins to form on each side, at the level of the base of the lungs,
which gradually closes together at a central point, ao as to form
the diiiphrugm, and Anally tu shut off altogether the cavity of
the chest frum that of the abdomen. Before the closure of tho

AND ITS APPENHAGES.

6d5

Hiaphrngm, thua formed, is cDmplebe, a circular opening exi»t5 on
each 8i(!e ihe rnediari line, by which the peritoneal and pleural
cavities commanicflte with each other. In some inetancea the de-
velopment of the diaphragm is arrested at this point, cither on one
aide or the other, and the openiag accordingly remains permanent.
The abdominal organs then partially protrude into the cavity of
the chest on that side, forming congenital diaphmgmatie ftemia.
The lung on the affected side also uaually remains in a state of
imperfect development. Diaphragmatic hernia of this character is
more fretjuently found upon the Itifl side ihun upon the right. It
may sometimes continue until adult life without causing any seri-
ous inconvenience.

The heart is formed, at a very early period, directly in frt>nl of
the situation of the cesophagus. Its size soon becomes very large
in proportion to the rest of the body; so that it protrudes buyond
the level of the thoracic parietes, covered only by the pericardium.
Subsequently, the walls of the thorax, becoming more rapidly
developed, grow over it and inclose it. Iq certain instances, how-
ever, they fail to do so, and the heart then ramaina partially or
completely uncovered, in front of the chest, presenting the condiiiotj
known as ectopia cordis. This mnlformation is neeeumrily fat&L

development of M« Face. — While the lower extremity of the
pharynx comtuunicatea with the cavity of the stominch, as above
described, its up{>er extremity also becomes perPoratwl in a similar
manner, nnd establishes a communication with the exterior. This
perforation is at first wide and gaping. It afterward becomes
divided into the mouth and nasal passages; and the difieruut puns
of the face are formcfi round it in the fol-
lowing manner: —

From the aides of the cephalic mass five
buds or processes shoot out, and grow
toward each other, so aa to approach the
centre of the oral orifioe above mentioned.
(Fig. 241.) One of them grows directly
downward from the frontal region (i), and
is called the frontal or intermaxillary pro-
cess, because it afterward contains in its
lower extremity the intermaxillary bone:s ■i>b«uiihPt»'M,i{(,ih4*r. Arwr
in which the incisor teeth of the upper irSJ:;^^^^,!^.':;
jaw are inserte<l. The next process (s) oriei-rm.«in.f7PT..«- i i-nv
ongmatcs from the side of the opening, «^„f ,„(„i„,„...iu

PiB. 241.

686

DBTCI.OPMEST OP THE ALIUEXTABY CAKAL

and, advancing toward the meHinn line, forms, with ilfi telloirortlii
opposite side, the superior tnuxilla. The processes or the remkinis^
pair (3) also grow from the sifie, and form, by their auhsetpicit
uoion upon the median line, the inferior maxilla. The inferior
maxillary bone ia finally con(((i1i<l»ted, in man, into a single pi«t,
but remains permRnently divided, in the lower animalii, byasulan
upon the median line.

As the frontal process grows from above downward, it beoomei

doable at its lower extremity, nod u
^' the same time two uSdhooU iImw

themselves upon its sidea, which cvt
round and inclose two areolar ot\-
lices, the opening of the anterior
naros; the oflithoota thcm»elres be-
coming the alte nasi. (Fig. 242.) The
mouth at this period is very widelj
open, owing to the imperfect develop-
ment of the up|>Gr and lower jnw.ind
the incomplete formation of the lip
H«*i>iTr iirH<.-f r,BRHTaat>bwit and cheeks.
.„.ho,'. >..«-!«=. The processcg of the aupenor mtx-

ilia continue their growth, but lot
rapidly than those of the inferior; so that the two oidca of ibe
lower jaw are already oonsalidated with each other, while tbose of
the upper jaw are still separate.

As the processes of the superior maxilla continue to enlarge, tb«;
also Lend to unite with each other on the median lia«, but are pre-
vented from doing so by the intermaxillary processes which gro«
^lown between them. They then unite with the intermaxillnv

processes, which have at tbe same time
united with each other, and the upper
jaw and lip are thus completed. (Kig.
'lA'i.) The external edgo of the alt
nnsi also adheres to thti superior tomX'
illary process and unites with it, leaviof
only a curved crease or furrow, as ■
sort of cicatrix, to mark tho line of
union between them.

Sometimes the superior maxilUr^
and the intermaxillary processes fsil
ti»«K iif ui«*» (.»«»T.., ttfcuui ,g ynijg ^it,^, gj((.i, Other; and wetbes

Ihp mil i.f ihi" --i-iiii-il niiinih — Ftom » , , ,^ .

•pMimf[iiaii.«*iiii..'r'M>'>'H>»>ixn. liavg iQu mulfurmaLiuu ktiowo asaiu*-

Vis. 24.1.

AS'D ITS APFKNDAOK3. 6S7

Kp. The fissure of bare lip, consequently, is never exactly in the
median line, bnt a little to one side of it, on the external edge of
the intermaxillarj process. Occasionally, the same deficiency exists
on both sides, producing "double hare-lip;" in which case, if the
fissures extend through the bony structures, the central piece of the
superior maxilla, which is detached from the remainder, contains
the four upper incisor teeth, and corresponds with the intermax-
illary bone of the lower animals.

The eyes at an early period are situated upon the sides of the
head, so that they cannot be seen in an anterior view. (Fig. 241.)
As dcTelopment proceeds, they come to be situated farther forward
(Fig. 242), their axes being divergent and directed obliquely for-
ward and outward. At a later period still they are placed on the
anterior plane of the face (Fig. 248), and have their axes nearly
parallel and looking directly forward. This change in the situa-
tion of the eyes is effected by the more rapid growth of the pos-
terior and lateral parts of the head, which enlai^e in such a manner
as to alter the relative position of the parts seated in front of them.

The palate is formed by a septum between the mouth and nares,
which arises on each side as a horizontal plate or offtihoot from the
superior maxilla. These two plates afterward unite with each
Mher upon the median line, forming a complete partition between
the oral and nasal cavities. The right and \e(t nasal passages are
also separated from each other by a vertical plate (vomer), which
grows from above downward and fuses with the palatal plates be-
low. Fissure of the palate is caused by a deficiency, more or less
complete, of one of the horizontal maxillary plates. It is accord-
ingly situated a little to one side of the median line, and is fre-
quently associated with hare-lip and fissure of the upper jaw. The
fissures of the palate and of the lip are very ofWn continuous with
each other.

The anterior and posterior pillars of the fauces ore incomplete
vertical partitions, which grow from the sides of the oral cavity,
and tend to separate, by a slight constriction, the cavity of the
month from that of the pharynx.

When all the above changes are accomplished, the pharynx^
OBSoph&gus, mouth, nares, and fauces, with their various protections
and divisions, have been successively formed; and the development
of the upper part of the alimentary canul is then complete.

638

DKVKLOPUEXT OF THE EIDNSTS.

CHAPTER XVr.

DEVKT.OPMEN'T OF T FT E KIDNEYS. WOI.FFr AX
BOPIKS.AND INTERNAL ORGANS OF OEKE-

RATION.

FlK. 344.

The 6rdt trace of a uriaary apparatus in tbe embryo, consists of
two long, fusiform bodies, which make their appearance in the ab-
domen at a very early period, situated on each side the spinal
column. These are known by the name of the Wolffian bodin.
They are fully formed, in the human subject, toward the end of the
first month (Coste), at which time they are the largest organs in the
cavity of the abdomen, extending from just below the heart, nearly
to the posterior extremity ot' the bo(3y. In the fccita) pig, when a
little over half an inch in length (Fig. 244), the WolfTian bodies are
rounded and kidney nhaped, and occupy a very large part of the
abdominal cavity. Their ImportaQco may be estimated from the
fact that their weight at this time is equal to
n little over ^'i of that of the entire body — a
proportion which is seven or eight times as
large aa that of the kidneys, in the adult
condition. There are, indeed, at this period,
only three organs perceptible in the abdo-
men, viz^ the liver, which has begun to be
formed at the upper part of the abdominal
cavity; the inteutine, which ia already some-
what convoluted, and occupies iia central
portion; and the Wolffian bodies, which pro-
ject on each side the spinal oolomn.

The WoIfTan bodies, in their intimate

structure, closely reaemblc the adult kidney.

They consist of secreting tubules, lined with

epithelium, which run IVom tbe outer toward

the inner edge of the organ, terminating at their free extremities

'n small rounded dilatations. Into each of these dilated extremities

I' ix T * I, I'm, *i at BU Inch
loni; frdHi • (pfclnnD to lbs
aulliitiT'a poi-x-Hloii. 1. Uekil.
3 Amortot oiitfLnlij. :t, Po4-
tmrior txintoMj . 4. Wolin«ii
bodjr. Th* kbdomliiiil mll>
baTF Iwoneui •<•«)', lu orditr
l« *]|i<w tb« paalUvD of tlia
WoUBsn boHtm.

WOLPPIAN BODIES. 689

18 received a globular coil of capillary bloodvessels, or ghmfruhts,
similar to that of the adult kidney. The tubules of the Wolffian
body all empty into a common excretory duct, which leaves the
organ at its lower extremity, and communicates afterward with
the lower part of the intestinal canal, just at the point where the
diverticulnm of the allantois is given off, and where the urinary
bladder is afterward to be situated. The principal, if not the
only distinction, between the minute structure of the Wolffian
bodies and that of the true kidneys, consiBts in the size of the
tubules and of their glomeruli, these elements being considerably
lai^r in the Wolffian body than in the kidney. In the foetal
pig, for example, when about an inch and a half in length, the
diameter of the tubules of the WoliBan body is jj,„ of an inch,
while in the kidney of the same fcetus, the diameter of the tubules
ta only jI^ of an inch. The glomeruli in the Wolffian bodies
measure -^g of an inch in diameter, while those of the kidney mea-
snre only tbq of an inch. The Wolffian bodies are therefore urinary
organs, so far as regards their anatomical structure, and are some-
times known, accordingly, by the name of the "false kidneys."
There is little doubt that they perform, at this early period, a func-
tion analogous to that of the kidneys, and separate from the blood
of the embryo an excrementitious fluid which is discharged by the
ducts of the organ into the cavity of the allantois.

Subsequently, the Wolffian bodies increase for a time in size,
though not so rapidly as the rest of the body ; and consequently
their relative magnitude diminishes. Still later, they begin to
suffer an absolute diminution or atrophy, and become gradually
less and less perceptible. In the human subject, they are hardly
to be detected afler the end of the second month (Longet), and in
the quadrupeds also they completely disappear long before birth.
They are consequently fcetal organs, destined to play an important
part during a certain stage of development, but to become after-
ward atrophied and absorbed, as the physiological condition of the
foetus alters. During the period, however, of their retrogression
and atrophy, other organs appear in their neighborhood, which
become afterward permanently developed. These are, first, the
kidneys, and secondly, the internal organs of generation.

The kuinei/8 are formed just behind the Wolffian bodies, and are
at first entirely concealed by them in a front view, the kidneys
being at this time not more than a fourth or a fifth part the size of

610

DEVBLOPXENT OF THE KIDSEVS.

FiB. 345.

t'XTAi. riu, va* >Di ft bklf
th>kulhxr'>p-i>wuluii — 1. Wulfliitt

the Wcilffinn botJiea. (Fig. 24.j.) As the kidneys, however, i
(juent)}' colarge, while the Wolffian bodies diminish, the propor.

lions existingbetwMn ihe two organs are
reversed; nrtd the Wolffian bodies at Jart
coino to be mere small rounded or ovoid
masses, situated on the anterior surface
of the kidnejrs. (I'iga, 246 and 247.) The
kidneyit, during this period, grow more
rapidly in an upward than iti n downward
direction, so that the Wolffian bodies
come to be situated near their inferior
extremity, and seem to have pertbrraed
a sliding movement from above down-
ward, over their anterior surface. This
apparent eliding inovcmont, or descent
of the Wolffian bodies, is owing entirely
to the rapid growth of the kidneys in aa
upward direction, as we have already explained.

The kidneys, during the Bucceediug periods of foetal life, become
in their turn very largely developed in proportion to the rest of the
organs; attiiining a size, in the fecial pig, equal to ,'j (in weight)
of that of the entire body. This propurtioo, however, diminishes
agaia very considerably before birth, owing to the increased deve-
lopment of other parts. In the human foetus at birth, the weight
of the two kidneys taken together is j^^ that of the entire body.
Internal Organs of ffcKero/Joti.— About the same lime that the kid-
neys are ibrmud behitid the WulHian bo-
dies, two ovalahaj»ed organs make their
appearance in front, on the inner side of
the Wolffifin bodies and between ihem
and the spinal column. These bodies are
the internal organa of generatioo ; vis.,
the testicles in the male, and the ovaries
in the female. At first they occupy
precisely the same situation and preseul
precisely the same appearance, whether
»*t,o,. *= ; in « r^ui pi« iht.. tlie loetua is afterwani to belong to the
inoii*' i<M>f. From » -j.^imro la ih, male Of the female sex. (Fig. 246.)
ti w,.i«.B I.L.J1™ i.s 3nt-r«i A abort distance above the lotemal
ors*D.o.g*B.niii«a;i*.tici«.,o«. orgiina of generation there commeaoes,

urrooi. .V ]Dir>iiii<L on each side, a narrow tube or duct,

Pig. 3«.

\
<

I
I

VALE ORGANS OF GENERATION. 641

which rnaa from Above downward along the anterior border of the
Wolffian body, immediately in front of and parallel with the excre-
tory duct of this organ. The two tubes, right and left, then approach
each other below; and, joining upon the median line, empty, together
with the ducts of the Wolffian bodies, into the base of the allantois,
or what will afterward be the base of the urinary bladder. These
tabes aerre as the excretory ducts of the internal organs of genera-
tion ; and will afterward become the vasa deferentia in the male, and
the Falhpian tube$ in the female. According to Co8te,the vasa de-
ferentia at an early period are disconnected with the testicles; and
originate, like the Fallopian tubes, by free extremities, presenting
each an open orifice. It is only afterward, according to the same
author, that the vasa deferentia become adherent to the testicles, and
a communication is established between them and the tabuli semi-
niferi. In the female, the Fallopian tubes remain permanently
disconnected with the ovaries, except by the edge of the fimbriatoi
extremity; which in many of the lower animals becomes closely
adherent to the ovary, and envelopes it more or less completely.

MaJe Organs of Gfeneration ; Descent of the Testicles. — In the male
foetus there now commences a movement of translation, or change
of place, in the internal organs of generation, which is known as
the "descent of the testicles." In conseqnence of this movement,
the above organs, which are at first placed near the middle of the
abdomen,, and directly in front of the kidneys, come at last to be
situated in the scrotum, altogether outside and below the abdominal
cavity. They also become inclosed in a distinct serous sac of their
own, the tunica vaginalis testis. This apparent movement of the
testicles is accomplished in the same manner as that of the Wolf
fian bodies, above mentioned, viz., by a disproportionate growth of
the middle and upper portions of the abdomen and of the organs
situated above the testicles, so that the relative position of these
organs becomes altered. The descent of the testicles is accompanied
by certain other alterations in the organs themselves and their
appendages, which take place in the following manner.

By the upward enlargement of the kidneys, both the Wolffian
bodies and the testicles are soon found to be situated near the
lower extremity of these organs. (Fig. 247.) At the same time, a
slender rounded cord (not represented in the figure) passes from
the lower extremity of each testicle in an outward and downward
direction, crossing the corresponding vas deferens a short distance
above its union with its fellow of the opposite side. Below this
41

642

DBTBT^OPMBITP OF THB RIDNEYS.

FlK. 247.

A*., In ■ ivtiil f\g nparly fniar IdtIisb 1odj|.
Prou ■ ■pMinaD in tlie katbni'a paaiauloii,—
1, 1. K1<lo*f>. 3, 2 Wolfflu bi>dia>. X S.

TtMklM. 4. DrlB«i7 bladdM-. e. IntMlIn*.

cODTcrted into the epi'dirit/mis.

poiDt, tbe cord spoken of continues to run obliquely outward aad
downward ; and, pausing throug'h the abdominal walls at the situa-
tion of the inguinal canal, ia inserted into the subcutaneous tiAsuea

near the symphyais pubis. The
lower part of this cord becoma
iho guhrmaatlum (estie; and rnus-
cular fibres are soon developed ia
it8 substance which may be easily
detected, even in the human foetus,
during the latter half of gestation.
At the period of birth, howerer,
or soon afterward, these muscoUr
fibrea disappear aud can no looser
be recognized.

All that portion of the ex
tory tube of the t«8ticle which ia
situated outside the crossing of the
gubemaculum, is destined to be-
come afterward convoluted, and
That portion which is situated in*
dide the same point reinaius comparatively straight, but becomes
considerably elongated, and is finally known as the vtu dt/erens.

As the testicles descend still farther in the abdomen, they con-
tinue to grow, while the Wolffian bodies, on the contrary, diminish
rapidly in size, until the latter become much smaller than the tes-
ticles; and at lost, when the testiules have arrived at tbe internal
inguinal ring, the Wolfiian bodies have altogether disappeared, or
nt least have become so much altered that their characters are no
longer recognizable. In the human fcetus, the testicles arrive at
the internal inguinal ring, about the tormination of the sixth month
(Wilaon).

During the succeeding month, a protrusion of the peritoneun
takes place through the inguinal canal, in advance of the testicle;
while the la^t named organ still continues its descent. As it then
passes downward iuto the scrotum, certain muscular fibres are given
fiff fnjm the lower border of the internal oblique maacle of the
abdomen, growing downward with the testicle, in such a manner as
to form n scries of loops upon it, and upon the elongating spermatic
cord. These loops constitute afterward tbe crematler mttacle.

At last, the testicle descends fairly tu the bottom of the scrolura,
the gubemaculum constantly shortening, and tbe tos deferens

HALE ORGArfS OF OKNKRATIOX.

643

eloTigftting an it proceeds. The convoluteti portion of the efferent
duct, viz., the epididymia, then remaina closely attached to the body
of tlie testicle; while the van Oeferens passes upward, in a rovenie
direction, enters the abdomen through tbe inguinal canal, again
bends downward, and joins its fellow of the opposite side; aHer
which they both open into the prostatic portioD of the urethra by
distinct orifices, situated on each side the median line. At tbe
same time, two diverticula arise from the median portion of the
vasa deferentia, and, elongating in a backward direction, underneath
the base of the bladder, become developed into two compound
•ftcculatcd reservoirs — the vfiieula aeminaks.

The lef\ testicle is a little later in its descent than the right, but
it afterward passes farther into the scrotum, and, in the adult ooadi-
tion, usually hangs a litite lower than its fellow of tbe opposite aide.

After the testicle has fnirly passed into the scrotom, ihc serous
poach, which preceded its descent, remains for a time in commuai-
cation with the peritoneal cavity. lo many of the lower animals,
as, for example, the rabbit, this condition la permauent; and the
testicle, even in the adult animal, may be alternately drawn down*
ward into the scrotum, or retracted into the abdotnen, by the action
of tbe gabemacaluro and tbe cremaster muscle. But in the human
fcetus, the two opposite surfaces of the peritoneal pouch, covering
the testicle, approach each other at the inguinal canal, forming at
that point a constriction or peck, which partly shuts oft' the testicle
from the cavity of the abdomen. By a
continuation of this prooeas, the serous
anrfaces come actually in contact with
each other, and, adhering together at
this situation (Fig. 248, 4), form a kind
of cicatrix, or umbilicus, by the coni|iletti
closure and consolidation of which tbo
cavity of the tunica vaginalis (a) is tinally
shut off altogether from the general cavity
of tbe peritoneum (i)t The tunica vagi-
nalis testis is, therefore, originally a part
of the peritoneum, from which it is sub- P-mMu-.n ..r t,.ii . v*.
aequently separated by the process just „„„„ m the houom »i .w «■«-
described "^'*' ' c«*i<]roridni»*igfDktu

- 1. 1 ■ !■ 3. C^Tlly 0/ i««ll«ii«um I UbltlM-

The separation of the tunica vaginalis >i«! Mck or pamouai mc.
m tbe peritoneum is usually completed
{d the human subject before birth. But sumetiines It fails to take

bfroi

Q44

TIETELOPMBST OP TB« KIDNEYS, ETC.

PIk. S49.

C«>tw«>if«i.Ijiuoia«LllcB-
Uns.

place At the proper time, and the inteatiae is then apt to protrade
into the scrotum, in front of t>ie spermatic cowl, giving riBe, in this
wiiy, to a eongeniial inr/umal hernia. (Fig. 249.) The parts impli-
cated, however, in this malformatioD, have
Ktill, as in the case of cungfuttal umbili-
cal hernia, a tendency to unite with each
other and obliterate the unnatural open-
ings; and if the intestine be retained by
pressure in the cavity of the abdomen,
cicairii'.mion usi>aI1y inkcs plaoo at the
inguinal canal, and a cure is effected.

The descent of the testicle, above de-
scribed, is not uccomplifhed by the forci-
ble traction of the niuscular 6bres of the
trubernncnliim, as haa been described by
certain writers, but by a simple process
of growth taking place in different parts,
in dirt'erent direetions, at successive periods of fcetal life. The
giibcrnaculum, accordingly, haa no proper function as a muscular
organ, in the human subject, but is merely the anatomical veatige,
or analogue, of a corresponding muscle in certain of the lower
animab, where it haa really an important function to perform. For
in them, as we have already mentioned, both the gubemaculum
and the cremaster remain fully developed in the adult condition,
and are then employed to elevate and depress the tesUole, by the
alternate coutraetioa of their muscular tibrea.

Femah Orgam of Oeneraiion, — At an early period, as wc have
mentioned above, the ovnriea have the same external appearance,
and cNXupy the Knme position in the abdomen, as the testicles in the
opposite sex. The descent of the ovaries also takes place, to a great
extent, in the same manner with the descent of the testicles. When,
in the early part of this descent, they have reached the level of the
lower edge of the kidneys, a cord, analogous to the gnbernacQlam,
may be seen proceeding from their lower extremity, crossing the
efferent duct on each side, and passing downward, to l>e attached
to the subcutaneous tissues at the situation of the inguinal ring.
That part of the duct situated outside the crossing of this cord,
l«comes afterward convoluted, and is converted into the Falhpfoa
tuU; while that part which is inside the same point, becomes con-
verted into the ulervs. The upper portion of the (X)rd itself beoomes

FEMALE ORGANS OF GENERATION. 645

the ligament of the ovary ; its lower portion, the rourui Ugament of
the utenu.

As the OTaries continue their descent, they pass below and be-
hind the Fallopian tubes, which necessarily perform at the same
time a movement of rotation, from before backward and from
above downward ; the whole, together with the ligaments of the
ovaries and the round ligaments, being enveloped in double folds
of peritoneum, which enlarge with the growth of the parts them-
selves, and constitute finally the broad ligaments of the uterus.

It will be seen from what has been said above, that the aituation
occupied by the Wolffian bodies in the female is always the space
between the ovaries and the Fallopian tubes; for the Wolffian
bodies accompany the ovaries in their descent, just as, in the male,
they accompany the testicles. As these bodies now become grad-
ually atrophied, their glandular structure disappears altogether;
hot their bloodvessels, in many instances, remain as a convoluted
vascular plexus, occupying the situation above mentioned. The
Wolffian bodies may therefore be said, in these instances, to un-
dergo a kind of vascular degeneration. This peculiar degeneration
is quite evident in the Wolffian bodies of the foetal pig, some time
before the organs have entirely lost their original form. In the
oow, a collection of convoluted bloodvessels may be seen, even in
the adult condition, near the edge of the ovary and between the
two folds of peritoneum forming the broad ligament. These are
nndoabtedly vestiges of the Wolffian bodies, which have under-
gone the vascular degeneration above described.

While the above changes are taking place in the adjacent organs,
tbe two lateral halves of the uterus fuse with each other more and
more upon the median line, and become covered with an exces-
nvely developed layer of muscular fibres. In the lower animals,
the otems remaiDB divided at its upper portion, running out into
two long conical tubes or comua (Fig. 182), presenting the form
known aa the uterus bicomia. In the human subject, however, the
fbrion of the two lateral halves of the organ is nearly complete;
■o tliat the uterus presents externally a rounded, but somewhat
flattoted and triangular figure (Fig. 183), with the ligaments of the
OTory and the round ligaments passing ofi^ from its superior angles.
But, internally, the cavity of the organ still presents a strongly
marked tnaognlar form, the vestige of its original division.

Occasionally the human uterus, even in the adult condition, re-

646

DETSLOPHKNT OF TDK KISNIT8, STC.

inainB divided into two lateral portions hy a vertical septum, whA
runs from th« middle of itJ fundus downward toward the as in-
t«ruum, Tbia septum may even be accompanied "by a partial
external division of the organ, currespoudiog with U io dinecttoo,
and producing tho malformation known as " uterus btoorats,'' or
"double uterus."

The OS internum and oa externum are produced by partial coo-
stricUona of the original generative passage; and the anatomical
distinctions between the body of the uterus, the cervix and the
vagina, are produced by tho different development of the maom
membrane and muscular tunic in its corresponding portiouL
During fcetal life, however, the neck of the uterus grows mncfa
faster than its body; so that, at the period of birth, the entin
organ is very far from presenting the form which it ejthibita in the
adult condition. In the human frntus at term, the cervix aleri
constitutes nearly iwothlrda of the entire length of the orgaa;
while the body forms but little over one third. The oeivix, it
tliiri lime, is also miioh larger in diameter than the body; sothu
the whole organ presetila a tapering form from beluw upward.
The arbor vil« utcrina of the cervix ts at birth very fully dfr
velupeJ, and the mucous membrane of the body ia also thro^^H
iuto three or four folds which radiate upward from the oe interunH
The caviiy of the cervix is filled with a traiispanuit serai-auhd
mucus.

The position of the uterus at birth is also different from that
which it assum«;s in aduU life; nearly the entire length of the or;giQ
being above the level of the symphysis pubis, and its ioferioc
extremity passing below that point only by about a quarter of aa
inch. It is altio slightl)' antefloxcd at the junction of the body and
cerrix. Afler birth, the uterus, together with its appendages, ooo-
tinues to descend; until, at the period of puberty, its fuudoa ii
situateil jtiftt bolow the level of the symphysis pubis.

The ovaria at birth are narrow and elongated in form. They
contain at this time an abundance of eggs; each inclosed io i
GrauOan folliule, and averaging «{) of an inch in diameter. Tiu
vitellua, however, is imperfectly formed in most of them, and io
some is hardly to be dieatinguished. The Graafian follicle at this
|>eriod envelopes each egg closely, there being nothing between ill
internal surface and the exterior of the egg, excepting the thin
layer of cells funning the "uiembruna granulosa." loside this

FEHALB ORGANS OF GE:7BRATI0!T. 647

layer ia to be seen the germinative vesicle, with the germtnative
spot, surrounded by a faiDtly granular vitellus, more or leas
abundant in different parts. Some of the Graa6an follicles con-
taining eggs are as large as ^Jg of an inch; others as small as tvis<
In the very smallest, the cells of the membrana granulosa appear
to fill entirely the cavity of the follicle, and no vitellus or germina-
tive vesicle is to be seen.

64S DEVELOPMENT OF THE CI Ri'UL ATOBV APPARATUS.

CHAPTER XVII.

DEVELOPMENT OF THE CIBCOLATORY APrABATUS.

Thbre are tlireu ili(:tinct forins or phases of development ussumed
by the circulatory system during different periods of life. Tbese
dtfiercnt forms of the circulation are intiniately connected with ibt;
manner in which nutrition and resplrniion, or the rcnovntion of the
blood, are accomplished at dift'ereiit epiKrhs; and they fullow each
other in the progresH of development, as diHerenl organs are em-
ployed in turn to accomplish the above functions. The first form
ia that of the vUeiUne circulation, which exi:ita at a period when ibe
vitellug, or the umbilical vesicle, is the sole source of nutrition for
the foetus. The second ia the phcmtal circulalion, which laau
through the greater part of footal life, and ii characterized by the
existence of the placenta; and the third is the complete or aduil
circulation, in which the renovation and nutrition of the blood are
provided for by ttie lungs and the inleatinal canal.

first, or ViitiiUne Oircuhttion. — It baa alrea<ly been shown, in a
previous chapter, that when the body of the embryo has begun to
be formed in the centre of the blastodermic membrane, a namber
of bloodvessels shoot out from its sidos, and ramify over the
remainder of the vitelline sac, forming, by their inosculation, ao
abundant vascular plexus. The area occupied by ihia plexus in the
blastodermic membrane around the fietus is, as wo havo seen, the
"area vasculusa." In the egg of the fowl (Fig. 250), the plexus ia
limited, on its external border, by a terminal vein or sinns — the
"sinus terminalis"; and the blood of the embryo, after circulating
through the capillaries of the plexus, returns by several venous i
branches, the two largest of which entor the body near its anieriur ■
and poaierior extremities. The area vasculosa is, accordingly, a
vascuUir appendage to the circulatory apparatus of the embryo, j
spread out over the surface of the vitellus for the purpose of absitrb- m
iag from it the nutritious material requisite for the growth of the
newly-formed tissues. In the egg of the fish (Fig. 251), the prhici-

I
I

TTTET.I.TKB ClKCUl.ATIOIf.

649

pal vein is seen passing up in front underneath tlio hcai3; while the
ftrteries emerge all along the lateral erlges of ihe body. The entire
vitellus, in this way, becomcx coveritd witli an abiiixlaiit vasi'utar

Flir. 250.

VfR. SSI.

%mm oT Fnw i. Id prwitmM of datalutmiMil, ■hnrtnj anw •aicntiiu. irttli c*Li»iiiiia (fnalBiifta,
tormla*! •Isa*, 4«.

network, coTmectcl with the ioternul uirculation of the foetus by
arteries and veins.

Very soon, as the embryo and the entire egg increase in s\ze,
there are two arteries ami two veins which become
larger than the other:*, and which subsequently
tlo ihe wliole work of conveying the blood of
the foetus to and from the area vasculosa. These
I wo arteries emerge from the lateral cdgca of
the foetus, on the right and lefl sides; while the
two veins re-enter at about the Ramc point, and
nearly parallel with thenm. These four vessela are
then termed the omp/talontesenlerie arteries and
tvina.

The arrangement of the circulatory apparatus
in the interior of the body of the fcelus, at this time, is ad follows:
The heart is situated on the median line, just beneath the head an'l
in front of the oesophagus. It receives at ita lower extremity the
trunks of the two onnphalo-mesentcric veins, and at its upper
e.xtremity divides into two vessels, which, arching over backwanl,
zittain the anterior surface of the vertebral column, and tben run
frnra above downward along the spine, quite to iho posterior
extremity of the foetus. These arteries are called the vertebroi
aricrits, on account of their course aud situation, running parallel

Bn'i or V (•* (Jar-

rsb«CCIIl,>taWlBJ|TlWl-

aoa elrral4llii«.

950 UKVKLOPMSl

IGUr.ATOl

with the vertebral column, They give off, throughoal their coarse,
manj amall lateral braauhes, which supply the botly of the fcetga,
and also iwo larger branuhes — the orophalo-mesuntcnc arteries —
which pnes out, as above described, into the area vasculosa. The
two vertebral arteries remam separate in iho upper part of the body,
but 80OD fuse with each other a little below the level of the heart;
to that, below this point, there remains aflerwani but one large
artery, the abdominal aorta, running from above downward along
the median line, giving off the omphalo- mesenteric arteries to the
area vasculosa, and supplying smaller branches to the body, th«
walls of the intestine, aud the other organs of the faitus.

The above description shows the origin and formation of the fint
or vitelline circulation. A change, however, now begins to take
place, by which the vitellus is superseded, as an organ of nutrittoD,
by the placenta, which takes its place; and the second or pUuxntal
circulation becomes established in the following maaner: —

Snxmd Circulation. — After the umbilical vesicle has been formed
by the process already described, a part of the vilcllus remains
included id it, while the rest is retained in the abdomen and >nclo«ed

in the iDtestioal canal. As these
^*' ^*^' twourgaii«(umbilical vesicle and

intestine) are originally parts of
the samevitelliDesac.ihey remain
supplied by the same vascular
system, viz: the omphala-meseu-
teric vessels. Those which remain
within the abdomen of the foBtos
supply the mesentery and intea*
tine ; but the larger truuks pass
outward, aud ramify upon tbe
walls of the umbilical vesicle.
(Kig. 252.) At first, there are,
as we have mentioned above,
two omphalo- mesenteric arteries
emerging from the body, and two
omphalo-mcsenteric veins return-
ing to it; but soon afterward, the two arteries are replaced by a
common trunk, while a similar change takes place in tbe two veina
Subsequently, therefore, there remains but a single artery and a
single vein, connecting the internal and external portions of the
vitelline circuhition.

iriuRnin nl Vi'L'xu Lwdiiio Ann itk

TMlck, nod ■!» ihal o( alLiuituU, brgiDnlng lu
httntmnA.

PLACBKTAt. CtltOULATIOl

651

The vessels belonging to this system are therefore called the
ompbalo-meseDterlc vessels, because a part of them (otnplialio ves*
eels) JM168 outward, by the urabiticus, or "omphalos," to the umbili-
oal veeiclo, while the remainder (mcdeoterio vessels) ramify upun
the mesentery and the intestine.

At first, the ciroulatioii of the umbilical vesicle is more import*
aot thaa that of the intestine; and the omphalic artery and vein
appear accordingly as large trunks, of which the mewjnicric ves-
sels are simply small branches, (Fig. 252.) Afterward, however,
the intestine rapidly ealarges, while the umbilical vesicle diini*
nishea, and the proportions existing between the two sets of ve^iMls
are tlicrefure reversed. (Fig. 2bA.) The mesenteric vcsauts llicn

r\g. 253.

MMfmn of EaiOTo tio it« Vihil*: •Vii>«'lBf ih« BMand dtpnlMlan. Til* pKuriraX,
■■i^baio*. >o4 tnlB-lliiftt «•■>!. h«rf b«e«iiifl funliflr d-r'teWp*-!, and Ibe n<i*»«l»rlc iirt*~r.M hifa
ealuKod. wliUt ihi? uiublllnl TnivleaDit H« lueuUi brmcbM •(* r«rr uofib r«daMd U >Im. Ttm
Un« nmblllcal Rrtnrim Bre hvd jixiIil) oqt lt> [h« pUcraiii

come to be the principal Irunka, while the ompli&Hc veaseld are
simply minute branches, running out along the slender cord of the
umbilical vesicle, and ramifying in a few aoant/ twigs upon its
surface.

In the mean time, the aUantois is formed by a protrusion from
the lower extremity of the Intestine, whiuh, carrying with it two

662 DKVKI.OPJIKNT OF TilK CI RCDLikTOBT APPABATCS.

arteries and two veina, passes out by the anterior opening of tlie
body, and comes in contact with the external menibrane of the
I egg. The arteries of the allaiitois, which are termed the umbilieal
arlerifa, are supplied by branches of the abdominBl aorta; the am-
btlical veins, on the other hand, join the mesenteric veins, and
empty with them into the venous extremity of the heart, Aathe
□mbiltuul vesicle dimintshes, tlie allantois enlarges; and the latter
soon becomes converted, in the human subject, ioto a vascolar
churicn, a part of which is devoted to the formation of tbe placenta.
(Fig. 2&8.) As the placenta soon becomes the only »oaroe of nutri-
tion for the fa'tus, its vessels are at the same time very moch
increased iu »ize, mid pruponderntu over all the other parts of the
circulatory system. During the early periods of tbe formation of
the placenta, there arc, as we have stated above, two ombilicil
arteries and two umbilical veina. But subsequently one of the
veius disappenrSf and the whole of the blood is retarned to the body
of the fcetuH by the other, which becomes enlargnl in proportion.
For a lung time previous to birth, therefore, there arc in the umbili-
cal cord two umbilical arteries, and but a aingle umbilical vein.

Such is the second, or placental circulatioiL It ia exchanged, at
tbe period of birth, for the third or aduU circulatiun, in which tba
blood which hud previously circulated through the pinnwiu. n
diverted to the longs and the intestine. These ore the orgtas
upon which the whole system afWrvrard depends for the ooaxiib>
roent and renovation of the blood.

During the occurrence of the above ofatnges, oeriain other altera-
tions take plnce in the arterial and Tenooa syalfroa, which will oov
require to be describetl by themselves.

Dtvehpmmt of the Arterial System.~^St an early period of deffr
lopmcnt, as we have shown above, the principal arteriea pua off
from the anterior extremity of the heart in two arches, which corre
backward on each side, from the front of the body toward tbe
vertebral column, afler which they again become longitodiual in
direction, and recrtivo the name of "vertcbnil arteries." Very soot
thaic arctics divide successively into two, three, four, and flvi
secondary arches, placed one above the other, along the atdw of
the neck. (Fig. 254.) These are termed the cervical wxhea. In the
fisli, these cervical arches remain permanent, and give oft from iheir
convex borders the branchial arteries, in the form of vaaculnr tulV,
10 the gills on each side of the neck; but in the human subject ami
the quadruoeds. the branchial tufts are never developerl, and tlw

DETELOFHBNT OP THE ABTEBIAL 8TSTEH.

658

cerrical arches, as well as the trnaka with which they are cod-
nected, become modiSed by the progress of development in the
following manner: —

Fig. 254.

Pig. 2S5.

Karlf eondiltan of Amtikiil Stitik:
vhuwlng th* heart (I), wllh lu two mM«nd-
Idb ftHirlal trunk*, f1*lD| oS on ench ilda
Are c*r*tcal arrbri, whicli lermlnnle la ihc
Tertsbral atterlei (2, S). Tbe vertebral arls-
riee nnIM below Ihe bean to form the
sorU(a).

A4 nit condition of A iTiiniAL 8t«-
TiH— I, 1. Caroild*. S,S. Verlebraln.
3. 3. RlBht and left •nbelavlani. 4, t.
Right and left inpertor Inlereoetali. A.
L«lt lortle areb, which reuaini perma-
nent S. Bight aortic arch, which dle-
•ppeara.

The two ascending arterial trunks on the anterior part of the
neck, from which the cervical arches are given off, become con-
verted into the carotids. (Fig. 255, i, i.) The fifth, or uppermost
cervical arch, remains at the base of the brain as the inosculation,
through the circle of Willis, between the internal carotids and the
lAsilar artery, which is produced by the union of the two verte-
brals. The next, or fourth cervical arch, may be recognized in an
inosculation which is said to berery constant between the superior
thyroid arteries, branches of the carotids, and the inferior thvroids,
which come from the subclavians at nearly the same point from
which the vertebrals are given off. The next, or third cervical arch
remains on each side, as the subclavian artery (*, a). This vessel,
though at first a mere branch of communication between the cam-
tid and the vertebral, has now increased in size to such an extent,
that it has become the principal trunk, from which the vertebral

8o4 DEVKLOPMBNT OF TUB CIRCL'LATORT APPABATU5.

itself is given olTas a small branch. Immediately below this point
of intersection, also, the vertebral nrtery diminishes verj mac^ in
its relative size, loses its connection with the abdominnl aorta, tod
supplies only the first two intercostal spaces, under the name of tbe
superior intercosut artery («, «). The second cervical arch becomei
altered in a very diilerent manner ou the two opposite sides. On
the left side, it becomes enormously enlarged, so as to give of!) is
secondary branches, all the other arterial trunks which have been
described, and is converted in this manner into the arch of tlu
aorta (s). On the right side, however, the corresponding arcfa(«]t
becomes smaller and smaller, and at last altogether disappear?; so
thnt, finally, we have only a single aortic, arch, projecting to tBc
lcf\ of the median line, and continuous with the thoracic and abdo-
minal aorla.

The first cervical arch remains during foetal life upon tbe rigtil
side, as the "ductus arteriosus," presently to be described. In the
adult condition, however, it has disappeared equally upon the rigkt
aud left sides. In this way the permanent condition ofilie arterial
circulation is gradually established in the upper part of tbe body.

Corresponding changes lake place, however, during the aame
time, in the lower part of the body. Hero the abdominal aofU
runs undivided, upon the median line, quite to the end of the
spinal column ; giving off on each side successive lateral branches
which supply the intestine and the parietea of the body. When
the allantoia begins to be developed, two of these lateral brancbv
accompany it, and become consequently tbe umbilical arteriti.
These two vessels increase so rapidly in size, that they soon apfnr
as divisions of the aortic trunk ; while the original ooDtlnaatioo of
this trunk, running to the end of the spinal column, appeari oolj
as a small branch given off at the point of bifurcation. Wbeo tbe
lower limbs begin to be developed, they are supplied by two small
branuhes, given off from the umbilical arteries near their origin.

Up to this time the pelvis and posterior extremities are ban
slightly developed. Subsequently, however, they grow moie
rapidly, in proportion to the rest of the body, and the arteriw
wliich supply them increase in a corresponding manner. Thu
portion of the umbilical arteries, lying between the bifurcation of
tbe aorta and the origin of the branches going to tb© lower ei-
tremities, becomes the common iliacs, which in their tarn afte^w^^i
divide into the umbilical arteries proper, and the femonils. Sab
sequently, by tbe continued growth of tbe pelvis and \anT

DETELOFHENT OF THE KEBTOUS 8TSTBH.

655

extremities, the relative size of their vessels is still farther id-
creased ; aod at last the arterial system in this part of the body
aasomea the arraogement which belongs to the latter periods of
gestation. The aorta divides, as before, into the two commoa iliacs.
These also divide into the external iliacf), supplying the lower ex*
tremities, and the iDternal iliacs, supplying the pelvis; and this
division is so placed that the umbilical or hypogastric arteries arise
from the internal iliacs, of which they now appear to be secondary
branches.

Afler the birth of the foetus and the separation of the placenta,
the hypogastric arteries become partially atrophied, and are con*
verted, in the adalt condition, into solid, rounded cords, running
upward toward the umbilicus. Their lower portion, however,
remains pervious, and gives off arteries supplying the urinary
bladder. The obliterated hypogastric arteries, therefore, the rem-
nants of the original umbilical or allantoic arteries, run upward
from the internal iliacs along the sides of the urinary bladder, which
is the remnant of the original allantois itself. The terminal con*
tinuation of the original abdominal aorta, is the arteria sacra media,
which, in the adult, runs downward on the anterior surface of the
eacrum, supplying branches to the rectum and the anterior sacral
nerves.

Devehpment of the Venous SyBtem, — According
to the observations of M. Coate, the venous system
at first presents the same simplicity and symmetry
with the arterial. The principal veins of the
body consist of two long venous trunks, the ver-
Ubral veins (Fig. 256), which run along the sides
of the spinal column, parallel with the vertebral
arteries. They receive in sucoession all the inter-
costal veins, and empty into the heart by two
lateral trunks of equal size, the eanaU of Ouvier.
When the inferior extremities become developed,
their two veins, returning from below, join the
vertebral veins near the posterior portion of the
body; and, crossing them, afterward unite with
each other, thus constituting another vein of new
formation (Fig. 257, a), which runs upward a little
to the right of the median line, and empties by
itself into the lower extremity of the heart. The
two branches, by means of which the veins of

Pig. 266.

EbtI; condltloB of V ■-
Roci Stitrmi ihov'
ing th« TirMbnl Talni
rmptrlog Into tfa* hoart
hj iwo iKtaral traoka,
Iha "onkUof CaTlBi."

PEVKM

t>>«i ■(UdirvJ, tliuvliif
hFi»ktt«nerilU«kkd nik-
(iaTlaa ipId* —n. Vain uf
Bi^v rvrniallAB. wblili h*-
(■>(n»> lh> lalrrtor tkdk
rata b. TntDionabraiirh
or ufw foruatian, which
• rirtwaril bKuno* Ibalafl
Tula iDDOnLlDiUk

Ft;. 23».

Fnribrr d*ti'lopmtnt of

lll(iTl!fO<1*8(aTtN —

! Tk* vtrlebral retot are

'■»•!> dlmlalibvd la >1m.

■■dlbaekoslufCdvltt.'O'D

tbe Ian iMe, U (riuliiilly

fbappMriBB r Trans-

tliia, vblch U lu WaiBi*
111* leoa ar>||ria nlDur.

roULATOHY APPAlAXrS.

the lower extremities thus unite, become after-
ward, by enlargement, the common iliac Teins;
while the single trunk (a) rcsuktiig from tlietr
union becomes the wna cava vn/erier. Sulae-
quently, the vena cava inferior becomes very
much larger than the vertebral veins ; and ita
two branches of bifurcation are aflerward ^^|
presente<l by the two iliiLc&

AIhivc the level of the heart, the venebtil
and intercostal veinn retain their relative vm
until the development of the superior extrnai-
tie« haa commenced. Then two of the iaicr-
costal veins incrcflse in diameter (Fig. 257), aad
become con verte<l into the right and leftaab*
olavians; while those portions of the vertebnl
veins situated above the subclavinna become
the right and Icfl jugulars. Juat below ihe
junction of the jugulars with the subclaviaas,
a 8i[iaEI brunch of communication now appean
between the two vertebrals (Fig. 257, l\ pan*
ing over from lefl to right, and emptying talo
the right vertebral vein a little above the level
of tlic heart; bo that a part of the blood cotniag
from the lefl side of the bead, and the left upper
extremity, still paasea down the left vericbnl
vein to the heart upon its own side, while a pan
crositcs over by the communicating branch {h),
and is finally conveyed to the heart by the
right descending vertebral. Soon n[Verward,tfaii
branch of commutiication en1arge:s so rapidly
that it preponderates altogether over the left
superior vertebral vein, from which it ongi
nateU (Fig. 1259), and, serving then to convey
all the blood coming from the left side of the
head and left upper extremity over to the right
side above the heart, it becomes the left mm
imtommaia.

On the lefl side, that |K)rtion of the superior
vertebral vein, which is below the sqbcUvUa,
remains as a small branch of the vena ionoou-
nnia, receiving the six or seven upper int«roaalaI

DSTELOPMBNT OF* THE NSBTODB BTSTXK.

667

Fig. 259.

veins; while od the right side it becomes excessively enlarged,
receiving the blood of both jiigolars and both snbclaviana, and is
converted into the vena cava superior.

The left canal of Cuvier, by which the left vertebral vein at first
communicates with the heart, snbsequently becomes atrophied and
disappears; while on the right side it becomes excessively enlarged,
and forms the lower extremity of the vena cava superior.

The superior and inferior vensB cavse, accordingly, do not cor-
respond with each other so far as regards their
mode of origin, and are not to be regarded as
analogoaa veins. For the saperior vena cava
is one of the original vertebral veins; while
the inferior vena cava is a totally distinct vein,
of new formation, resulting from the nnion of
tbe two lateral trunks coming from the infe-
rior extremities.

The remainder of the vertebral veins finally
assume the condition shown in Fig. 269, which
is the complete or adult form of the venous
circulation. At the lower part of tbe abdomen,
the vertebral veins send inward small trans-
verse branches, which communicate with the
vena cava inferior, between the points at which
they receive the intercostal veins. These
branches of common lea lion, by increasing in
Mze, become the lumbar veins {^\ which, in the
adult condition, communicate with each other
by arched branches, a short distance to the side
of the vena cava. Above the level of the
lumbar arches, the vertebral veins retain their
original direction. That upon the right side
still receives all the right intercostal veins, and
becomes tbe vena azygos major (s). It also
receives a small branch of communication from
its fellow of tbe left side (Fig. 258, c), and this branch soon enlarges
to such an extent as to bring over to the vena azygos major all the
blood of the five or six lower intercostal veins of the left side,
becoming, in this way, the vena azygoa minor {t). The six or seven
upper intercostal veins on the left side still empty, as before, into
their own vertebral vein (lo), which, joining the left vena innomi-
nata above, is known as the superior intercostal vein. The left canal
42

Adalt eoadltlon of Vi-
■ ODi SrfTan.— 1. Ufbt
knriela or be»rt. 3. Veoft
cmTii mpcrior. 3, 3. JngaUr
Tela*. 4, 4. BnbaUTUn relni,
A. Vena mt* liir«rior. t, 6.
IIImvbIiu. T. LamlMitralBii.
8. VaDK aijgoa major. S.
VcDB ai7goi> mlBor. 10. Sn*
perlor laMrooaul retn.

ftOS DEVELOPMEXT OF TBS CIBCULATOBY APPABATC8.

Fig. 260.

of Cuvier Iian by thiit time entirely diaappeaTed ; so tb&t a\\ ts
venoua blood now enters the heart by the saperior or the iotenot
rena csva. But the original vertebral veins are still oootinoom
throQgliout, though very mnch diminished in size at certain pointi;
since both the greater and lesser azygoos veins inosculate bclo«
with the superior lumbar veins, and the superior intercostal ran
also inosculates below with the lesser azygoas, just before it paoes
over to the right side.

There are still two parts of the circulatory apparatus, the deT^
lopmenl of which presenta peculiarities sufficiently importaat to
be described separately. These arc, first, the liver and the duauj
venosus, and secondly, the heart, with the ductus arterioaua.

Detxlojiment of the Hepatic Circulation and the Dvetua VimonM.—
The liver appears at a very early period in the upper part of the
abdamcn, as a mnss of glandular and vascular tissue, which ii dere-
loped around the upper portion of the on-
phalo-mesenterio vein, just below its termi-
nation in the hoarL (Fig. 260.) As soon u
the organ has attained a oonsiderable ue,
theomphalo-mesenteric vein {i) breaks up in
its interior into a capillary plexus, the veiaeli
of which unite again into venous truoVs, sod
ao convey the blood finally to the heart
The omphalo-mescnteric vein belov the liver
then becomes the jiortal vein; while above ibe
liver, and between that orgaa aod the heart
it receives the name of the hepaiie vein (x).
The liver, accordingly, is at this time supplied
with blood entirely by the portal vein, eon-
ing front the umbilical vesicle aod the intestine ; and all the blooj
derived from this source must pass through the hepatic circalatiou
before reaching tho venous extremity of the heart.

But soon aflerward the allantois makes its appearance, andlx-
comcs rapidly developed into the placenta; and the umbilical nia
comiitg from it joins the omphalo-meseitlerio vein in the substaooe
of the liver, and takes part in the fornmtioo of the bepatio capillarr
plexus. As the umbilical vesicle, however, becomes atropbied,ud
the intestine also remains inactive, while the placenta inoreBseflia
sise and in functional importance, a time soon arrives when the
liver receives more blood by the umbilical vein than by the porul
vein. (L^'ig. 2S1.) The umbilical vein thea passes into the liver iL,

CiaoPiATicix. 1. Oni|>l<a-
l»-Bi«M«trrte r«|a, S. K«|«-
tidVrlD. » lli-»r1 Thrilullri]
ILu* ahuirji ihn ulliinrUiii at

DETELOPHBST OT THE HEPATIC CTHCOLATfoN. 65ft

fuithnradTanCMl —I. Purial rain.
3. L'uitlUnl nln. S. H>|bii«

the longituflinal fissure, and suppliea the left lobe entirely with its
own branches. To the right it sends off a large branch of com-
munication, which opens into the portal vein, and partially supplies
lh« right lobe with umbilical blood. The liver is thos supplied
with blood from two ditterent sources, the
meet abundant of which is tho umbilical Fig. S61.

vein; and all the blood entering the liver
ctrcDiatcs, as before, through its capillary
TCBsels.

But we have already seen that the liver
is much larger, in proportion to the entire
body, at an early period of fwtal life than
in the later months. In the footal pig,
when very young, it amounts to nearly
twelve per cent, of the weight of the whole
body; but before birth it diminishes to
seven, six, and even three or four per cent.

For some time, therefore, previous to birth, there is much more
blood returned from the placenta than is required for the capillary
circulation of the liver. Accordingly, a vascular duct or canal in
formed in ita interior, by which a portion of the placental blood ta
carried directly through tho organ,
and conveyed to the heart without
having passed through the hepatic
capillaricfl. This duct is called the
Dtictfts venoattg.

The ductus venosua is formed by a
gradual dilatation of otio of the hu-
patic capillaries at (&) (Fig. 262),
which, enlarging excessively, be-
comes at last converted into a wide
canal, or branch of communication,
passiug directly from the umbilical
vein below to the hepatic vein above.
The circulation through the liver,
thug established, is as follows: A
certain quantity of venous blood still
enters through the portal vein (i).
and circulates in a part of the capil-
lary syfitem of the right lobo. The umbilical vein (3), bringing a
mucli larger quantity of blood, enters the liver also, a little to the

Fig. 262.

i-\

HcFATrr CIHCCI.4TI0W dortiiK lat-
ter PKTI or {ail»\ Uf«.— 1. PoUaI v«la. I
T'BiMIIinl ivln. S Lcfl liraneli u-t anititll-
tkl vrln. 4. aicbl bntaeh of ainl.limi
Tele. a. Ditciiu voDiuiu. t. n»i«ilc
Tain

960 DCVKT.OPMENT OF THE CIBCULATORY APPARATUS.

left, and the bloml wliich it oontains divides into three principal
gtreanis. One of them passes through the leil branch (a) into ibe
capillaries of the lefi lobe; another turns off throagh the right
branch («), and, joining the blood of the portal vein, circulate*
through the capillaries of the right lobe; while the third puses
directly onward through the venous duct (a), and reacliea the he-
patic vein without having passed through any part of the capilUrv

This condition of the hepatic circtilatioa continues until birth.
At that time, two important changes take place. First, the pU
cental circulation is altogether cutofT; and secondly, a tnuuh larger
quantity of blood than before begins to circulate through the lung:(
and the intestine. The superabundance of blood, previously comiog
from the placenta, is now diverted Into the lungs; while the intes-
tinal canal, entering upon the active performance of its functions,
becomes the sole source of supply for the hepatic venous blood.
The following changes, therefore, take place at birth iu the vessels
of the liver. (Fig. 263.) First, the umbilical vein shrivels and
becomes converted into a solid rounded cord (t). This cord may
be seen, in the adult condition, running from the internal surface of
the abdominal walls, at the umbilicus, to the longitudinnt fissure of

the liver. It is then knowu under the ^J
name of ihertnind UgamaU. SeooDdly,^|
the ductus venosus also becomes ob- ^*
literated, and converted into a fibrous
cord. Thirdly, the blood entering the
liver by the porlal vein (>), pa«tM» oIT
by its right branch, as before, to the
right lobe. But in the branch (4), ilie
course of the blood is reversed. This
was formerly the right branch of the
umbilical vein, its blood passing in a
direction from left to right. It now
becomes the led branch of the portal
vein; and ittf blood pas»ea from right
to lef^ to be distributed to the capil-
laries of the left lobe.

According to Dr. Guy, the ambilt<
cal vein is completely closed at the
end of the 6fth day atler birth.
Dcitfcpment of ihe Heart, and the Ductus ArUrwsus. — When the

Fig. 2(!3.

Adnll forni «f lt«P*tiii Cocri.*-
rroft.—l. Portal t«Ib. % OMIunM
nenlilllrkl >«li. furmtof !>■■ rouuiL ligk-
lattnl ; IhB faollduKlloa at ib* doIlM
Imn itrnBgh tka 1l>*i (howi Lh« tliiu-
llcA of tht itbltHral«4 dMiti* *»««■.
a ■■■(kilt Toln. (. Lad fcrMcb ofpurl*!

DETSLOPMIXT OF THE BKAKT. 6BX

embryoDic circulation is first established, the heart is a simple tubu-
lar 880 (Fig. 264), receiving the veins at its lower extremity, and
giving off the arterial trunks at its upper extremity. By the pro-
gress of its growth, it soon becomes twisted npon itself; so that the
entrance of the veins, and the exit of the arteries, oome to be placed
more nearly upon the same horizontal level (Fig. 266); but the
entrance of the veins ( i ) is behind and a little below, while the exit
of the arteries (a) is in front and a little above. The heart is, at
this time, a simple twisted tube; and the blood passes through it
in a single continnous stream, taming npon itself at the point of
curvature, and passing directly out by the arterial orifice.

Fin. 264. Fig. 265.

FatTAti HRAmr, dliided

brIlMirormorFaTAt Fixt*l Hbabt, twl*t«d loto right ftnd laft mtKIm.—

RKABr.-~l Venom as- npoa Iwalt. — 1. Vaboai ex- 1. T«BOiti •xtMulir. S.

Inmli7. S. Artarlkl tx- trenltj. 1. ArMrIM axtn- Artarlal aitramlir. 3, 3.

Inmll7. niil7. PolnoBary branebea.

Soon afWrward, this single cardiac tube is divided into two paral-
lel tubes, right and left, by a longitudinal partition, which grows
from the inner surface of its walls and follows the twisted course
of the organ itself. (Fig. 266.) This partition, which is Indicated
in the figure by a dotted line, extends a short distance into the
commencement of the primitive arterial trunk, dividing it into two
lateral halves, one of which is in communication with the right side
of the heart, the other with the left.

About the same time, the pulmonary branches (■, s) are given
off from each side of the arterial trunk near its origin ; and the
longitudinal partition, above spoken of, ia so placed that both these
branches fall upon one side of it, and are both, consequently, given
off from that division of the artery which is connected with the right
side of the heart.

Very soon a superficial line of demarcation, or furrow, shows
itself upon the external surface of the heart, corresponding in situa-
tion with the internal septum; while at the root of the arterial
trunk this furrow becomes much deeper, and finally the two lateral
portions of the vessel are separated from each other altogether, in

682 DEVELOPMBXT OF THS CIHCULATORT APPABATCS,

PaTAi.l)iAat><mikr.
thBritpretopM — I, Aorta.
2, Putnuoarj nrtarjr. 1, 3

Duciua anarioiiM.

the iinmediote oeighborhood of the beai .
joining again, honrever, a sbort distance beyond
the origin of the pulmonary branches. (Fig.
267.) It then becomes evident that the left
lateral division of the arterial trank is tbe
conimencemcnt of the aorta ( i ); while its righ:
lateral division is the trunk of the pultnonan
artery (a), giving off the right and left polno-
nary branches (>, s), at a abort distance Erou
ita origin. That portion of the pnlmooarj
trunk (4) which ia beyond the origin of the
pulmonary branches, and which communicates freely with tb*^
aorta, is the Dttcttu arieriotiu, V

The ductus arieriosua is at first as large as the pulmonary tnolc
itself; and nearly the whole of the blood, coming from the right
ventricle, passes directly onward through the arterial duct, aaj
enters the aorta without going to the lungs. But as the loop
gradually become developed, they require a larger quantity of
blood for thuir nutrition, and the pulmonary branches increase a
proportion to the pulmonary trunk and the ductus artcriosu*. At
the termination of foetal life, in the human subject, the ductus
arteriosus ia about as large as either one of the puImoDirr
branches; and a very considerable portion of the blood, therefore,
coming from the rtglit ventricle still passes onward to the aorti
U'itfaout being distributed to the lungs.
But nt the period of birth, the lungs enter upon the active per-
formance of the function of respiratin.
and immediately require a much larger
supply of blood. The right and left
pulmonary branches then enlarge^ lo
as to become the two principal dtrii-
ions of the pulmonary trunk. (Fig. 26S.)
The ductus arteriosus at the sftoie Qaw
becomes contracted and shrivelled tosocfa
an extent thai its cavity is obliterated;
and is finally converted into aa tO'
HajHT or iKFAKT. •h»vii]| pervious, rounded cord, which remsiaa
S^'r.:'r;rr:;r "^^'I ^^^It nfe, running from the poial
i*rj. 3.3. puimoMrTiinacnM. *. of bifurcation of the pulmonary arterv

Pig. £88.

DKTELOPMENT OF THK HEART. 668

Borta. The obliteration of the arterial duct is complete, at latest,
by the tenth week afler birth. (Gay.)

The two aariclea are separated from the two ventricles by hori*
zontal septa which grow .from the internal surface of the cardiac
walls; bnt these septa remaining incomplete, the auriculo- ventricu-
lar orifices continue pervions, and allow the free passage of the
blood from the auricles to the ventricles.

The interventricular septum, or that which separates the two
ventricles from each other, is completed at a very early date ; bat
the interauricular septum, or that which is situated between the
two auricles, remains incomplete for a long time, being perforated
by an oval-shaped opening, the foramen ovale^ allowing, at this
situation, a free passage from the right to the left side of the heart.
The existence of the foramen ovale and of the ductus arteriosus
gives rise to a peculiar crossing of the streams of blood in passing
through the heart, which is characteristic of foetal life, and which
may be described as follows : —

It will be found upon examination that the two vene cava,
superior and inferior, do not open into the auricular aoc on the
same plane or in the same direction ; for while the superior vena
cava is situated anteriorly, and is directed downward and forward,
the inferior is situated quite posteriorly, and passes into the auricle
in a direction from right to left, and transversely to the axis of
the heart. A nearly vertical curtain or valve at the same time
hangs downward behind the orifice of the superior vena cava and
in front of the orifice of the inferior. This curtain is formed by
the lower edge of the septum of the auricles, which, as we have
before stated, Is incomplete at this age, and which terminates
inferiorly and toward the right in a crescentic border, leaving at
that part an oval opening, the foramen ovale. The stream of blood,
coming from the superior vena cava, falls accordingly in front of
this curtain, and passes directly downward, through the auriculo-
ventricular orifice, into the right ventricle. But the inferior vena
cava, being situated farther back and directed transversely, opens,
properly speaking, not into the right auricle, but into the lefl: for
its stream of blood, falling behind the curtain above mentioned,
passes across through the foramen ovale directly into the cavity of
the left auricle. This direction of the current of blood, coming
from the inferior vena cava, is further secured by a peculiar mem-
branous valve, which exists at this period, termed the Eustachian

684 DEVKLOPJfKMT OF THB OIBCULATOBT APPABATP*.

valfe. This valve, which is very thin and transpareot (Fig. 2Q9,/\
is attached to the anterior bonier uf the oritiue of the itifehor vena
cava, and terminates by a cresoentic edge, directed towani the left;

the valve, in thia way, standing
F\g. 2£9. ;)s an incomplete membranous

partition between the cavity of
the inferior vena cava and thai
of the right auricle. A bougie,
uccordiogly, placed io the in*
ferior vena cava, ns showD id
Fig. 209, lies naturally quite
behind the Eustachian valve,
aud passes directly through
the foramen ovale into the left
auricle.

Tlie two streams of blood.

therefore, coming from the »u- i

poriur and inferior venoB cavie.

cross each other upon eDterinij

the heart. This crossiDg of the

.streams does not take pUcf,

however, as it is soroetimes

described, in the cavity of the

right auriule; but, owing to the

peculiar position and direction

of the two veins at this period.

with regard to the septum of

the auricles, the stream coming from the superior vena cava enters

the right auricle exclusively, while that from the inferior

almost directly into the lefl auricle.

It will also be seen, by examining the positions of the aorta, pal^
monary artery, and ductus arteriosus, at this time, that the arteria
innominata, together with the left carotid and left, subclavian, are
given off from the arch of the aorta, before its junction with the
ductus arteriosus, and this arrangement causes the blood of the two
vena) cavae, not only to enter the heart in different directions, hut
also to be distributed, after leaving the ventricles, to different parts
of the body. (Fig. 270.) For the blood of the superior vena cava
passes through the right auricle downwanl into the right ventricle,
thence through the pulmonary artery and ductus arteriosus, iolo
the thoracic aorta, while the blood of the iDferior vena cava, enter-

tiEiliT «r tli'B** P<BTt-*. Hi thread at (ho
nlxlli tuu-alh , fr.^rii it «]i..riiD.«ci In Ih>n kathof's )*9*-
■•waloa. — 0. li)(iirt«r T«Q* cbTi. b. SaperlorTcoa
ear*, c. Ca>JI^ <tt tistat auricle, Utl opon fntm
l>i« tniBl d. Apprndli aurloulnil*. (. CatKj of
rljtbtvaalrteli),Bl>alaldup«D. /. KnaUchUn vulr*.
Tlia btiogl*, vbkli U plsnn] In th« Iti'tiirlaT Tana
rxra, ena bo wpii paMlSji b«blad ibe Kaslafhlao
Tnltt. Jaal hrlnw ilir imlul Indlralcd tiy /, Ilian
cruaalnfi Whlad (K« eitiUj u( Iha rlghl anrlvla, aod
(iMiilfla (bniiiih tb« lorauan eraJ*, to tba Ittl ilda
oriba liMiL

DKVKLOPMEKT OF THB HSABT.

665

Fie. 2"('.

ing the }e(i anricle, posaes iuto the left ventricle, thence into the arch
of the aorta, and is distributed to the bead and upper extremlticfl,
before reaching the situation of ilie arterial duct. The two sireamfi,
tberefore, in passing through the heart, cross each other both behind
and in front. The venous blood, returning from the head jmd
upper extremities by the superior
Tcna cava, pasacs through the abdo-
minal aorta and the umbilical arte-
ries, to the lower part of the bodj,
ftod to the placenta; while that re-
turning from the placenta, by the
inferior vena cava, is dislribiiteii to
the head and upper extremities,
through the vessels given oflf from
the arch of tbti aorta.

This division of the streams of
blood, during a certain period of
foetal life, is so complete that Dr.
John iieid/ on injecting the infe-
rior vena cava with red, and the
superior with yellow, in a seven
months' human fcetus, found that
the red bad passed through the foramen ovale into the leli auricle
and ventricle and arch of the aorta, and bad filled the vessels of
the head and upper extrumiiies: while the yellow had passed into
the right ventricle, pulmonary ortery, ductus arteriosus, and tho-
racic aorta, with only a slight admixture of red at the posterior
part of the right auricle. All the brunches of the thoracic and
abdominal aorta were QHed with yellow, while the whole of the red
had passed to the upper part of the body.

We have repeated the above experiment several times on the
foetal pig, when about one-half and thrce-qnarters grown, first taking
the precaution to wash out the heart and large vessels with a wa-
tery injection, immediately afier the removal of the fojtua from the
body of the parent, and before the blootl had been atloweil to ooagu-
Jate. The injections used were blue for the superior vena cava,
and yellow for the inferior. The two syringes were managed, ai
the same time, by the right and left hands; their nozzles being
firmly huld in place by the fingers of an osaistunt. When the

Dlngrmn ut r i arc 1 j t lov TaitAriiH
THt F<ETAL Hc*Ht.— a. Sa|Htriar t«B»
niti. t. Inferiiir «*Dar«T* r.c.r.e Arct
of lurU and lu liraueli**. il. Pnlin-ciiiaij

' EdiuburgU Uddlaal uiA SurylcaL JoanuU, tuI. xUli. 1S3S.

PW UKVELOPMBUT OP TH« CIKCULATOBY APfARATTB.

■points of the syringes were intrcxluced into the veins, at «jual dis-
tanc6B fmtn the heart, and the two injections made with equal fonx
and rapiditj, it was found that the admixture of the colors which
took place was ao slight, that at least nineteen-tweDtieths of ibe
vellow injection had passed into the kft auricle, and ninctetrn- twen-
tieths of the blue into the right. The pulmonary artery and ductus
Arteriosus contained a similar proportion of bine, and tfae arcbof
the aorta of yellow. In the thoracic and abdominal aorta, bowerar,
contrary to what was found by Dr. Reid, there was always an ad-
mixture of the two colors, generally in about equal proportioof.
This discrepancy may be owing to the smaller size of the head and
upper extremities, in the pig, as compared with those of tbo honiu
subject, which would prevent their receiving all the blood cotniog
from the led ventricle; or to some differences in the manipuUtioo
of these experiments, in which it is not nlwavs eos/ to imitate ex-
HCtly the fiirce and rapidity of the diQerent currents of blood in
the living foetus. The above result^ however, arc such as to leave
no doubt of the principal fact, viz., that up to an advaticed stage of
foatal lire, by far the greater portion of the blood comiog frointbe
inferior vena cava passes through the foramen ovale, into the loft
side of the heart; while by far the greater portion of that comrag
from the head and upper extremities passes into the right side of
the heart, and thence outwanl by the pulmonary iruok and dacttts
arteriosus. Toward the latter periods of gestatioo, this division
of the venous currents becomes less cumpleto, owing to the three
following causes: —

First, the lungs increasing in size, the two pulmonary arteries, m
well as the pulmonary veins, enlarge in proportion; and a greater
quantity of the blood, therefore, coming from the right veolritde,
iniitead of going onward through the ductus arteriosas, panes to
the lungs,, and returning thence by the pnlmonary veins to the left
auricle and ventricle, joins the stream passing out by the arcbof
the aorta.

Secondly, the Eustuchlau valve diminishes in si7.e. This valve,
which is very Urge and distinct at the end nf the sixth month
(Fig. 269), subsequently becomes atrophied to such an ext«ut that,
nt the end of gestation, it has altogether disappeared, or is at least
reduced to the condition of a very narrow, almost imperceplil
ineiiibranous ridge, which can exert no influence on the direct
of the current of blood passing by it. Thus, the cavity of the infe-
rior vena cava, at ius upper extremity, ceases to be separated from

DEVSLOPHENT OF THE HEART. 667

that of the right auricle ; and a passage oF blood from .one to the
other may, therefore, more readily take place.

Thirdly, the foramen ovale becomes partially closed by a valve
which passes across its orifice from behind forward. Thia valve,
which begins to be formed at a very early period, is called the
valve of the foramen ovale. It consists of a thin, fibrous sheet, which
grows from the posterior surface of the auricular cavity, just to the
lefl of the foramen ovale, and projects into the left auricle, its free
edge presenting a thin crescentic border, and being attached, by its
two extremities, to the auricular septum upon the lefb side. Thia
valve does not at first interfere at all with the flow of blood from
right to left, since its edge bangs freely and loosely into the cavity
of the left auricle. It only opposes, therefore, during the early
periods, any accidental regurgitation from left to right

Bat as gestation advances, while the walls of the heart con-
tinae to enlarge, and its cavities to expand in every direction, the
fibrous bundles, forming the valve, do not elongate in proportion.
The valve, accordingly, becomes drawn downward more and more
toward the foramen ovale. It thus comes in contact with the edges
of the interauricular septum, and unites with its substance; the
adhesion taking place first at the tower and posterior portion, and
proceeding gradually upward and forward, so as to make the pas-
sage, from the right auricle to the left, more and more oblique in
direction.

At the same time, an alteration takes place in the position of the
inferior vena cava. This vessel, which at first looked transversely
tovrard the foramen ovale, becomes directed more obliquely for-
ward; so that, the Eustachian valve having mostly disappeared, a
part of the blood of the inferior vena cava enters the right auricle,
while the remainder still passes through the equally oblique open-
ing of the foramen ovale.

At the period of birth a change takes place, by which the
foramen ovale is completely occluded, and all the blood coming
through the inferior vena cava is turned into the right auricle.

This change depends upon the commencement of respiration.
A much larger quantity of blood than before is then sent to the
lungs, and of course returns from them to the left auricle. The
left auricle, being then completely filled with the pulmonary blood,
no longer admits a free access from the right auricle through the
foramen ovale; and the valve of the foramen, pressed backward
more closely against the edges of the septum, becomes after a time

SXTZLOFHBirT OF THE UKABT. 669

ovaUif which iodicatee the site of the original foramen ovale. The
fossa oralis is surroaaded by a slightly raised ring, the onnu/ui
ovalui, represeDtJDg the curviliDear edge of the origiaal auricular
septum.

The foramen ovale is sometimes completely obliterated within a
few days after birth. It often, however, remains partially pervious
for several weeks or months. We havo a specimen, taken from a
child of one year and nine months, in which the opening is still
very distinct; and it is not unfrequent to 6nd a small aperture
existing even in adult life. In these instances, however, although
the adhesion and solidification of the auricular septum may not be
complete, yet no disturbance of the circulation results, and no ad-
mixture of blood takes place between the right and left sides of the
heart; since the passage through the auricular septum is always
very oblique in its direction, and its valvular arranj^ment prevents
any regui^itation from left to right, while the complete filling of
the left auricle with pulmonary blood, as above mentioued, equally
opposes any passage from right to left.

670

DEVELOPMENT OF THE BODT AfTER KIKTII.

CHAPTER XVIII.

UEVELOrMENT OP THE BODY AFTER BIBTH.

The ncwly-bom infmit is still very far from having arrived at a
slate of complete developmeot. The changes through which it ban
passeil during intra-uterine life are nut more market! than those
which are to follow during the periods of infancy, childhood, ami
adolescence. The anatomy of the organs, both internal and ex*
tcrnal, their physiological fbDctioos, and even the morbid derange-
meota to which they are subject, continue to undergo gradual and
progressive alterations, throughout the entire course of subsequent
life. The history of dcvolopmont extends, properly speaking, from
the earliest organization of tho embryonic tissues to the complete
formation of the adult body. The period of birth, accordingly,
marks only a siogle epoch in a constant series of changes, some of
which have preceded, while many others are to foUow.

The weight of the newly-born infant ia a little over six poundsL
The middle point of the body is nearly at the umbilicus, the hea-I
and upper extremities being giill v^ry large, in proportion to the
lower extremities and pelvis. The abdomen is larger and the
chest smnller, in proportion, than in the a<lulu The lower extremi-
ties are curved inward, as in the foetal condition, so that the soles of
the feet look obliquely toward each other, instead of being directed
horizontally downward, as at a subsequent period. Both upper
and lower oxtremitiea are habitually curled upward and forwani
over the chest and abdomen, and all the joints are constantly in a
semi-flexe<l position.

The process of respiration is very imperfectly performed for
some time an.er birth. The expansion of the pulmonary vesicles,
and the changes In the circuliit*)ry apparatus described in the pre-
ceding ohapter, far from being sudden and instaDtaneous, are
always more or leas gradual in their character, and require an
interval of several daya for their completion. Respiration, indeed,
seems to be accomplished, during this period, to a considerable

DSTBLOPUBKT OF THS BOOT AFTBB BIBTH. 671

extent through the skin, which ia remarkably sofl, vascular, and
ruddy in color. The animal heat ia alao leaa actively generated
than in the adult, and requirea to be sustained by careful protec-
tion, and by contact with the body of the mother. The young
infant sleeps during the greater part of the time; and even when
awake there are bat few manifestations of intelligence or percep-
tion. The special aenses of sight and bearing are dull and inex-
citable, though their organa are perfectly formed; and even
consciousness seems present only to a very limited extent Volun-
tary motion and sensation are nearly absent; and the almost con-
stant irregular movements of the limbs, observable at this time,
are evidently of a reflex or automatic character. Nearly all the
nenroas phenomena, indeed, presented by the newly-born infant,
are of a similar nature. The motions of its hands and feet, the act
of suckling, and even its cries and the contortions of its face, are
reflex in their origin, and do not indicate the existence of any
active volition, or any distinct perception of external objects.
There is at firat but little nervous connection established witb the
external world, and the system is as yet almost exclusively occu-
pied with the functions of nutrition and respiration.

This preponderance of the simple reflex actions in the nervoos
system of the infant, ia observable even in the diseases to which it
is peculiarly aobject for aorae yeara after birth. It ia at this age
that convulsions from indigestion are of most frequent occurrence,
and even temporary atrabismaa and paralysis, resulting from the
same cause. It is well known to physicians, moreover, that the
effect of various drugs upon the infant ia very different from that
which they exert upon the adolL Opium, for example, ia very
much more active, in proportion to the dose, in the infant than in
the adult. Mercury, on the other hand, produces aalivation with
greater difRcuUy in the former than in the latter. ' Blisters excite
more constitutional irritation in the young than in the old subject ;
and antimony, when given to children, ia proverbially uncertain
and dangerous in its operation.

The difference in the anatomy of the newly-bom infant, and that
of the adult, may be represented, to a certain extent, by the fol-
lowing list, which gives the relative weight of the most important
internal organa at the period of birth and that of adult age; the
weight of the entire body being reckoned, in each case, as 1000.
The relative weight of the adult organs has been calculated from

672

DltVELOPMlXT OF THE BODY APTBR BIRTH.

Weight or tht> «ntJre hodj
" " cncepltiktnn

the estiinnles of Cniveilhier, Solly, Wilson, &c. ; that of the orgim
in the fcetus at term from our own ohfiervAtinnn.

Fom AT TtRM. AOCLT.

. lOOO^OO IWHt.KO

. 14S,00 23.00

liTW 37.00 29.00

hMit T.77 4.17

kldnorp .... S.00 4.W

rantl MpaulM . . . 1.63 0,1S

tbjTOld glufi . . . 0.(10 0.S1

" " thjrinu* gUnd . 8.00 O.00

It will be obiwrvecl tbal most of tbe internal organs diroiDish in
rclalivosize nl\cr birtb, owing principally to the increased deTe^^
menl of tbe osseous and muscular systems, both of which are in t
very imperfect condition throughout intra-uterine life, but wbicb
oome into activity during childhood and youth.

Within tbe first day ai\er birth tbe remains of the umbilical
(ord begin to wither, and become completely desiccated by about
the third day. A superficial ulceration then takes p1&c« about tbe
point of its attachment, and it is separated and thrown otT witbiu
the (irst wook. After the separation of the cord, the umbilical
becomes completely cicatrized by the tenth or twelfth daj after
birth, (tiny.)

An exfoliatiou and renovation of th« cuticle also take place
over tbe whole body soon after the birth. According to Kulliker,
ihu eyelaslies, and probably all tbe hairs of tbe body ond bead, are
thrown off and replaced by new ones, within the first year.

The teeth in the newly-born infant are but partially developed,
and are still inclosed in their follicles, and concealed betHAth the
gums. They are twenty in number; viz., two incisors, one oaaine,
iind two molara, on each side of each jaw. At birth there is a this
layer of dentine and enamel covering their upper surface*, hot
the body of the tooth and its fangs are formed Bubsequeolly by
progressive elongation and ossification of tbe tootb-palp. TIm
fully-rormed teeth emerge from the gums in the followiog order.
The central incisors in the seventh month after birth ; the lateral
incisors in tbe eighth month ; the anterior molars at tbe end oftlM
first year; the canines at a year and a half; and the second molan
at two years (Kolllker). The eruption of the teeth in the lower
jaw generally precedes by a short time that of the correspoDding
teeth in tlie upper.

During the seventh year a change begins to take place by wbtch

DBVKLOFHEKT OF THK BODT AFTER BIBTH. 67S

the iinit set of teeth are thrown off and replaced by a second or
permanent set, differing in namber, size, and shape from those
which preceded. The anterior permanent molar first shows itself
just behind the posterior temporary molar, on each side. This
happens at about six and a half years after birth. At the end of
the seventh year the middle incisors are thrown ofl' and replaced
"by corresponding permanent teeth, of larger size. At the eighth
year a similar exchange takes place in the lateral inciBors. In the
ninth and tenth years, the anterior and second molars are replaced
by the anterior and second permanent bicuspids. In the twelfth
year, the canine teeth are changed. In the thirteenth year, the
second permanent molars show themselves; and from the seven-
teenth to the twenty-first year, the third molars, or "wisdom teeth,"
emerge from the gums, at the posterior extremities of the dental
arch. (Wilson.) The jaw, therefore, in the adult condition, contains
three teeth on each side more than in childhood, making in all
thirty-two permanent teeth; viz., on each side, above and below,
two incisors, one canine, two bicuspids, and three permanent
molars.

The entire generative apparatus, which is still altogether inactive
at birth, begins to enter upon a condition of functional activity
from the fifteenth to the twentieth year. The entire configuration
of the body alters in a striking manner at this period, and the dis-
tinction between the sexes becomes more complete and well
marked. The beard is developed in the male ; and in the female
the breasts assume the size and form characteristic of the condition
of puberty. The voice, which is shrill and sharp in infancy and
childhood, becomes deeper in tone, and the countenance assumes a
more sedate and serious expression. After this period, the mus-
cular system increases still further in size and strength, and the
consolidation of the skeleton also continues; the bony union of its
various parts not being entirely accomplished until the twenty-fifth
or thirtieth year. Finally, all the different organs of the body arrive
at the adult condition, and the entire process of development is
then complete.

INDEX.

Absorption, 145

by bloodreBBeli, 148

by lact«ftlfl, 150-153

of fat, 154

of differest tiqnidg by animal snb-
8tano«g, 294

of oxygen in respiration, 225

by egg daring inoubation, 590

of cslcsKons matter by allantois,
590
Absorbent glands, 151, 299

Tessals, 150, 299
Acid, carbonic, 224-234

lactic, in gastric Jaice, 122, 123

in scoring milk, 318

glyko-cliolic, li)3

tan roch olio, 164

pneamic, 229

nric, 329, 33tt

oxalic, in urine, 341
Acid fermentation of nritie, 341
Acidity, of gastric Juice, caase of, 123

of arine, 336
Acini, of lirer, 320, 321
Adipose vesicles, 74

digestion of, 142, 143
Adult circulation, 652

establishment of, 667
Aerial respiration, 215-217
Age, influence of, on exbalatiou of car-
bonic acid, 232

on comparativa weight of organs,
672
Air, qnaulity of, used in respiration, 220

alterations of, in respiration, 223

circulation of, in lungs, 221
Air-cells of lungs, 217
Air-chamber, in fowl's egg, 536
Albumen, 84

of the blood, 206

in B&tiTa, 108

in mittc, 317

of the egg, how produced, 535

its liquefaction and absorption dur-
ing development of foetus, 586-
588
Albuminoid substances, 79

digestion of, 125
Albuminose, 12(>

interference with Trommer's test,
127

with action of iodine aQdatBrch,128

Alimentary canal, In different animals,
100-104

derelopment of, 628
Alkalies, effect of, on urine, 336
Alkaline chlorides, 55-56

phosphates, 61

carbonates, 60-61
Alkaline fermentation of urine, 342
Alkalescence of blood, due to oarbonates,

60
All&nt«ris, 683

formation of, 585

in fowl's egg, 588

function of, 689

in fojUl pig, 606
Alligator, brain of, 364
Amnion, 583

formation of, 684

enlargement of, during latter part
of pregnancy, 614

contact with chorion, 616
Amniotic folds, 584
Amniotic fluid, 614

its use, 616

contains sugar at a certain period,
633
Amniotic umbilicus, 584
Analysis, of animal fluids, 48, 49

of milk, 96, 316

of wheat flour, 96

of oatmeal, 96

of eggs, 97

of meat, 97

of Balira, 108

of gastric juice, 122

of pancreatio juice, 139

of bile, 159

of blood -globnles, 200

of blood-plasma, 206

of mucus, 310

of sebaceous matter, 311

of perspiration, 313

of butter, 318

of urine, 334

of fluid of thoracic dnot, 300

of chyle and lymph, 302
A5DRAL AKn Qatarbbt, productioa of

oarbonio acid in respiration, 232
Animal functions, 43
Animal heat, 235-245

in <lifferent species, 237

mode of generation, 239

676

INDEX.

Animal heat inflnenoed by local caases,'
243

in different organs, 244

increaBe of, after section of STmpo-
thetic iienre, 605
Animal and vegetable parasites, 516
Animalcules, infnsorial, 513

mode of production, 614
Aotinlas oval is, 6ti8
Anterior columns of spinal oord, 363

their exuitability, 387
Aorta, development of, 653
Aplasia, nervous system of, 357
Appetite, diaturhed by anxiety, he, 133

necessary to digestion of food, 133
Aquatic respiration, 215
Area pellncida, 574

vascalosa, 687, 649
Arch of aorta, formation of, 653
Arches, cervical, 652

transformation o^ 653
Arteriee, 263

motion of blood in, 264

pulsation of, 266-268

elasticity of, 263-266

rapidity of uircalatlon In, 271

omphslo-mesenterio, 649

vertebral, 652

umbilical, 652
Arterial pressure, 269
Arterial system, development of, 652-661
Articnlata, nervous system of, 368

reflex action in, 359
Articulation of tapeworm, 525
Arytenoid cartilages, 222

movements of, 223
Assimilation, 306

destrnotive, 323
Auricle, single, offish, 247

doable, of reptiles, birds, and mam'-
malians, 248, 249

contraction of, 261
Anricnlo-ventricular valves, action of,

251
Auditory apparatus, 491

nerves, 431,490
Axis-cylinder, of nervous filament*, 360,

352
Aztec children, 410
AzygouB veins, formation of, 657

Bkadhoht, Dr., experiments on Alexis St.

Martin, U&, 130
Bbrkard, on the different kinds of saliva,
109
on effect of dividing Steno's daot, 115
on digeslion of fat in intestine, 137
on formation of liver-sugar, 182, 183,

184
on decomposition of bicarbonates in

long, 229
on temperature of blood In different
organs, 244

BinDEB Asn Schmidt, on daily qnutitj
of bile, 171

on effect of excluding bile (Mm in-
testine, 177

on reabsorption of bile, 179
Bile, 158

eompoeition of, 159

tests for, 167

daily quantity of^ 171

functions of, 176

reaction with gastric jalee, 176

reabsorption, 179

mode of secretion, 319
Biliary salts, 160

of human bile, 166
Biliveidine, 87, 159

tests for, 167

passage into the nrine, 339
Blastodermic membrane, S72
Blood, 196

red globnles of, 196

white globules, 202

plasma, 206

coagulation of, 208

huffy coat, 212

entire quantity of, 213

alterations of, in respiration, 235

temperature of, 236

in different organs, 244

circulation of, 246

through the heart, 251
through the arteriea. 263
through the veins, 2J2
through the capillaries, 277
BoussisoACLT, on chloride of sodinm i
food, 57

on internal prodaotioo of bt, 77
Brain, 401

of alligator, 364

of rabbit, 31)5

human, 368

remarkable oasee of Injury to, 403
404

size of, in different races, 407
in idiots, 409

development of, 622, 623
Branchin, 214

of meno-branohns, 21S
Broad ligaments, formation of, 645
Bronchi, diviaion of, 216-217

ciliary motion in, 221
Brunner's glands, 136
Buffy coat of the blood, 212
Butter, 317

composition of, 318

condition in milk, 75, 317
Butyrine, 318

Canals of Cuvier, 6S5
Capillaries, 277

their inosculation, 279

motion of blood In, 279
Capillary circulation, 278

INDEX.

677

C«pilUr7 olrcDlatlon, causes of, 281
nplditj of, 283

pecuUsritlvB of, in different parts,
285
Capnt coli, formation of, 629
Carbonic acid, in the breath, 224

proportion of, to oxygen absorbed,

225
In the blood, 227
origin of, in Inngs, 229
in the blood, 230
in the tissues, 230
mode of production, 230
dailj qoantity of, 232
TariatioDS of, 233
exhaled b^ akin, 234

hy egg, daring incabation, 590
absorbed bj regetables, 242
Carbonate of lime, 60
of soda, 60
of potassa, 61

of ammonia, In pntrefjing arina,
343
Cardiac oironlation. In fcetns, 666

in ^alt, 668
CamiToroQS animals, respiration of, 34,
225
nrine of, 328, 330
Cartilaglne, 86
Caseine, 84
Cat, secretion of bile in, 171

cloBTire of ejelidfl, after dirision of
sympathetio, 506
Catalytic action, 82
of pepsin, 125
Centipede, nervons system of, 358
Centre, nervons, definition of, 355
C'erebmm, 368. See Hemispheres.
Cerebral ganglia, 364-369. See Uumi-

spheres.
Cerebellom, 413

effects of injnrj to, 415
remoTsl of, 415-417
function of, 414
development of, 622, 623
Cerebro-Bpinal ejetem, 360, 361

development oC, 621
Cervix Qteri, 538
iu fcetns, 646
Cervical arches, 652

transformation of, 653
Changes, in egg, while passing throagb
oviduct, 532, 536, 570
In hepatic cironlation at birth, 660
In oomparative siie of organs, after
birth, 672
Chxthedil, experiments on ImbibltloD,

294
Chick, development of, 586-591
Children, Astec, 410
Chloride of eodiam, 55

its proportion in the animal tissnes
and fiaida, 56

Chloride of sodinm, Importance of, in the
food, 57

mode of discharge from the bod/, 58

partial decomposition of, in the body,
68
Chloride of potassiom, 58
Cholesterine, 159
Chorda dorsalis, 675
Chorda tympani, 472
Chordn vocates, movement of, In respi-
ration, 222

action of, in the production of vocal
Boands, 449

obstniction of glottis by, after divi-
sion of pnenmogaBtrio, 451
Chorion, formation of, 592

villosities of, 694

scarce of vasonlarlty of, 696

union with deoldna, 603
Chyle, 150, 166, 301

inlacteala,J53

absorption of, 154

by intestinal epithellnm, 155

in blood, 166
Ciliary motion, in bronchi, 221

in Fallopian tabes, 657
Ciliary nerves, 498
Circnlatlon, 246

in the heart, 247-262

in the arterlee, 263

in the veins, 272

in the capillaries, 277

rapidity of, 284

pecoliaritles of, in different parts,
266

in liver, 321

in placenta, 609-663
Circulatory apparatus, development of,

648-669
Civilization, aptltade for, of different

races, 408
Classiflcatiou of cranial nerves, 432
Clot, formation of, 208

separation from serum, 209

buffed and cupped, 212
Coagulation, 82

of fibrin, 206

of blood, 208

of white «ubetaace of Bchwann, In
nerve-flbreB, 361
CoLiH, on unilateral mastication, 110
Cold, resistance to, by animals, 235

eflect of, when long continued, 236
Colostrum, 316
Coloring matters, 86, 87

of blood, 86, 200

of the skin, 87

of bile, 87, 159

of nrine, 87
Commissure, of spinal cord, gray, 362

white, 363

transverse, of cerebrum, 369

of cerebellum, 369

^^^^67^^^^^^^^^^^^IXDKI^^^^^^^^^^^^^^^^H

^^^1 CommiRsmva, nerroni, 355

CrreUU, of on^tlntiM;, 329 ^^^^|

^^H olfar-lorj. 3iU, «I2

urate of mmU, 330 ^^^^|

^^H Coag«Htlon, of ear, &c., aft«r dlrlfilmi of

of aril! ftoid. 336 ^^^H

^^H STinpAllivtiL', :i{)!!i

of oxaUM of limo, 342 ^^^^|

^^H CanroWuluB, inxual sppttratoa of, 534

of lripli» ph<>«phal«, 344 ^^^^B

^^H Co&Uct, of chorion und tmnJon, 61B

Crys tall iu bit) aabHtaavn of organic ori- ^B

^^^1 of ileoiiluai vi-ra aud t«llftXA, 616

gin, 51 • ^

^^^1 Conouniniiooun luitloij of roosolea, 414

Crowing of flbres In tDodaUa- pbloDgkta,

^^^1 Contrxction, at ntonuicli during digos-

$tiS

^^M 12H

of leualtiTe BbrM in apinsl oofd,

^^^^^^ of vplnrll, 100

389

^^^^K tilr>tvl-f lot, SiKI

of strcaina of blood to fatal beul.

^^^^^^H of <lia{ihrngiD mid lnt«r«UBtat muii*

644, SftS

^^^^H

Cbdikshakk. ropiure of OraaAao folUolt

^^^^^^M of pottonorcrico-nrjrtenold musclei.

In niAnatruation, 55fi

Cnmututt prol)g«ru«, 551 ^H

^^^^^H T«ntric1es,

Cauiniiou8 KKplratJoD, 234 ^H

^^^^^H of musclM iin«r doalb, 370

p«rap)raiioo, 312 ^H

^^^^^H of Hphinctvr iini, 398

Cuttcio, vxfDliation of, dortng fatal 1I5>,' ^|

^^^^^B

^^^^^H of Drb&ry Li1ii()d«r,'399

aftor birtli. 672 ^H

^^^^^^1 of pupil, uttdtT inllneiiae of liglit.

CyHtiocrcuK, 521 ^H

^^^^1 419, 4H&"2

tratiFfitrmalion of Into taals. 523 ^H

^^^^^V xftvT division of »jrtopatl)«tio,

pTodaction of, front «ggi of tMiU, ^|

^^^^

023 ' , H

^^^1 Cooking, (tflvot of, on food, 98

^H Cord, fpinal. 3^2^00

D«ath, a ncMuarr oolueqttenm of llfey ^|

^^^1 umliilicnl, (il3

^^^B witlinringftiid ftepanilionof, 672

Deddua, 59-t ^M

^^H Corpim cnllosum, 3«)9

vsra, iOO ^M

^^^^^ CorpnK Intpnm, &f>ti

reflAica, fiOl ^H

^^^^^^ft of mnniitriintiDiii, SS^f'Si

union with chorion, f>03 ^H

^^^^^H of prD^UHDcy, Gd4-SiS9

ill ducbargu iu uaMra ot sbortlta, ^M

^^^^^H itiTvf vcoks nfter mcnstrttMion, 5fl3

G02 ^1

^^^^^H four weekii ftf^er men it runt inn, 5G3

at lh« tinw of deliror^, <il7 ^H

^^^^^^H oln«i weeks aftitr tatrnelrualluii, 663

DecnaiatloD of anterior wltuDiu of epfml ^H

^^^^^^M Bl (?ud of jd-cond month of pr«g-

oord, 866

^^^^^H

of optio n<>rTM, 43n, 421

^^^^^1 aX end of fonrlh month, 536

Degeneration, fatty, of mosoalar Abm

^^^^^F at t«n», C(!7

of ukTUs, afler dolivory, 6l'J

^^H disappeAranoe of, afl«r delivery-, StiS

DeglDtillou, ll(i

^^V CoriKini Malplghlant, of Hploen, l!)l

retard*^ by dlrialon of StAno'a dnct,

^^B CttVponi Birlata, SUfi, 3liS, -103

iiri

^^H Cotpom oikarta, 3tJ(!

by division of pnctimontlrio,

^^H Carpora WolfflanA, (<38

447 ^

^^^1 CoTTK, on ni{)tu]-i- of OniafUn folHote iu

DanUtlon, first, 673 ^H

^^^1 naenttrui^iiuTi, !t!iii, 357

•ouoiid, 673 ^^^^M

^^H Cnnlnl n^Tv.':*, -iw

DMOent tbf tostielM, 641 ^^^H

^^^^^ olaaaiticitlloii uf, 432

of the ovaries, M4 ^^^^H

^^^^^L moior, 433

DMtruotire AluitniUiioa, 323

^^^^B sensltivo, m

DaTolopment of tlic iiapr«giLat«d «q, 670 m

^^^^^ CrMtitifl, 328

of allantoU. 585 ^|

^^B Creatluinu, 329

of chorioD, ssa ^H

^^H Cremaalcr tnuAolo, forniAlion of, Q42

of villoaillM of chorion, 593, 5U ^M

^^^B fanotiuii of, hi Innr^ir itDlDials, 643

of dwtdua. 698 ■

^^B Ct^iUU, of fttcAi-ini^, 71

of [ilaoenla, 6(>?-ei3 ^^^H

^^^B and nuirgarinv, 72

of nervoBs syiimu, 421 ^^^^|

^^^^^ of oliolvitorin, 160

of .70, r,a4 ^^H

^^^^^L of ftlT^o-i^h^'ate of soda. 1R1, 1112

^^^M

^^^^^^1 of biliary matt*n of dog's bilo, ISS,

of »kv1otMi, 626 ^^^H

^^^m

^^^H

^^^H or urvi., 32ft

of ititofiuiBont, 62T ^^^^H

^^^^H orratin*, 329

of alimeotary ainal, StB, 130 ^^^^M

INDSX.

679

DeTrinpment of arinsrj paflsages, 630

of liver. 632

of pharynx and OHophagas, 633

of face, 635

of ■Wolffian bodies, 633

of kidneys, 639

of Internal generative organs, S40

of oiroalatory apparatas, 648

of arterial Bjetem, 652

of Tenons systetn, 655

of bepatio olronlation, 658

of lieart, 660

of the body after birth, 670
Diabetes, 339

in fcetns, 6:^3
Diaphragm, action of in breathing, 218,
219

fonnatton of, 634
Diaphragmatiq hernia, 635
Diet, influence of on natrltioUf 90-92

on prodnots of respiration, 225

on formation of area, 327
of nrate of soda, 330
Diffusion of gases in longs, 221
Digestion, 99

of starch, 134

of faU, 137, 139

of sugar, 134

of organic sobstances, 124-126

time mqaired for, 130
Digestive apparatoa of fowl, 101

of ox, 102

of man, 103
Disobargp of eggs from ovary, 532

independent of sezaal interooane,
549

mechanism of, 652

daring menstruation, 556
Bisons proligeroB, 551
Distance and solidity, appreciation of, by

the eye, 465-487
Distinction between corpora latea of
menstruation and pregnancy, 568-569
Diamal variations. In exhalation of car-
bonic acid, 234

in prodaction of urea, 328

in density and acidity of arine, 333
Division of nerves, 353

of heart, into right and left cavities,
661
DoBBOx, on variation in slie of spleen, 190
Dkapkb, John C, on prodaction of urea,

327, 328
Drags, effect of, on newly bom infant,

671
Ductus arteriosus, 662

closure of, 662-663

venoans, 659

obliteration of, 660
Duodenal glands, 136

fistula, 173
DtTTBOCHET,on temperature of plants, 238,
242

DuTXocHBT, on endosmosls of water with
different liquids, 291

Ear, 491

muscular apparatus of, 492, 504
development of, 612
Earthy phosphates, 58, 61
in urine, 335

precipitated by addition of an alkali,
336
Ectopia cordis, 635
Egg, 524-528

iU contents, 529

where formed, 630

of frog, 632

of fowl, 535-536

changes in, while passing through

the oviduct, 532-535
pre-^xistence of. In ovary, 647
development of, at period of puberty,

548
periodical ripening and discharge,

549
discharge of, from Graafian follicle,

552
impregnation of, how accomplished,

645, 546
development of, after impregnation,

570
of fowl, showing area vasoulosa, 987
ditto, showing formation of allantois,

588
of fish, showing vitelline circulation,

689
attachment of, to uterine mucous

membrane, 603
discharge of from uterus, at the time

of delivery, 617
condition of in newly bom infant, 646
Elasticity, of spleen, 191

of red globules of blood, 198
of InngB, 217
of costal cartilages, 219
of vocal chorda, 223
of arteries, 263
Electrical onrrent, effect of, on muscles,
371
on nerve, 373

different effects of direct and inverse,
376
Electrical fishes, phenomena of, 379
Electricity, no manifestations of in Irri-
tated nerve, 380
Elevation of temperature, after division

of sympathetic, 243, 505
Elongation of heart in pulsation, 257, 258

anatomical caases of, 259
Embryo, formation of, 570
Embryonic spot, 574
Encepbalon, 363, 368, 401

ganglia of. 368
EndosmosiB, 289

of fatty Bubatances, 155

^H INDBX. ^^^^^^^^^^^^^^^H

^^H BndoMnoslfl In capillarv cErculatlon, 260

Farinatrcooi tabstxtMe*, 63 ^^^^H

^^1 oanditiono of, 2il(l'':>92

Iu food, M ^^^^M

^^H oaoM of, 2&:i

dlgOHtlOQ of. 134 ^^H

^^m ftf iodi4« of potiMsiati], 2sr^ 211;

Fat, dncampODition of^ In Ihtt blood, 1S3 ^H

^^H or alropliiu, 'hh

Fata, ■

^^H or nux romicn, 2d6

pmportion of, in ilifferent Idndu a! ^H

^^H l^ndiMiRoniiitor,

(uod, 7:^ H

^^H Eularf;ein<.'iit of ammou, during preg-

condition. En tbe tuiuub tlMtia a^l ^M

^^H naiic^, <il4, <tl5

fluid*, 73 ^H

^^H "Entototn enoyated, 01^

internal soaroe of, 77 ^|

^^H mode of prodaotioti, MO

deaompo«ed In the body, ?B ^H

J^^^t Epitketiam, iu aaliva, lOS

indinpi-nsabU aa ingredienta of tbe ^H

^^H of KK»trio rollk'lHH, 118

food. 91, 95 ■

^^H of IntMtin^.durtug digestion, ISS

Fatty m-ittera of the blood, 206 ^1

^^^1 Bpidermi-i, cxfulUliuaof, lofiiBUlUfw, 4127

Faltj* dei^Hiieratlon of d«cidiia, SIS ^|

^^H afUT blrib, 072

of uusenlar Abrea of ateras, after ^|

^^1 Epldidrmln, tA2

dellrerv, lilU H

^^^1 Hxctvliiif, 144

Feces, 144 ^1

^^H Kxorcvlun. 323

Female g«ni)ntUT« organa, 526 ^|

^^^^^ nnltire of, 3S4

of frog, &3I __^M

^^^^K IniporUnou to iitv, 324, 325

^^^M

^^^^^P prodncu of, 325

^^^^^^ hjr placenta, G12

^^^^M

of hntiiKn epeeiea, S3S ^^^^H

^^H BxorvrQpntitiflUs subsUooM, 323

dervlopment of, i;44 ^^^^|

^^H mode of fonnatlon of, 324

FemKHlatloo, b3 ^^^^H

^^^1 «ir«ot of r«t«ntlon of, 324

of sugar, 6S ^^^^M

^^^B ExfolUtlon of ciiUcl«, during firtal life,

acid, of urine, 341 ^^^H

alkaline, of diUo, 343 ^^^H

^^B KfttT birth, 672

Fibrin, U ^^^M

^^H Exhal&tlon, 2KJ

of the blood, 205 ^^^H

^^^K^^ at watcrv rjipor, 55

coagDblioi) of, aos liP^H

^^^^^L frain the lungi*, 224

rarylng qanntily of. Id blood of 4i^^^|

^^^^^B tram tbc Pkhi,

ferent Tpln.<, 206 ^|

^^^^^^H from tlia ngg, d iirinK incnbutiDn, 589

PIflli pair of rranial n*m>«, 4^5 ^H

^^^^H Vt onrbODic

Iu JUtHbution. 434 ^M

^^^^^'^ of nitrag«n, 2:24

divlttun of, panlTMB ae«eibEUl|' n( ^H

^^^V of Riiimnl vipor, 224

bo»,437 ■

^^H ExbAuelioD, of tuuHctes, by repeated Irri-

and of nacal pasBcge*. 438 ^H

^^M Ution, 372

prodnoes infUmnatloo of eys- ^M

^^H of nerves, by ditto, 374

bAll, 4311 ^H

^^H ExosnioslH, 289

llngnal branch of, 440 ^H

^^^M Expiralion, niovmnenta of, 219

■ null ruol of, 43^ ^^M

^^H after aeciioti of pneumogMtrio, 423

FUU, clrcnlatton of, 247 ^|

^^H RstracttTM t».-itU>r« of th« blood, 207

fnrmaiion of nmbillMl Tealale la, ^|

^^^H Bjru, prulMotioji (if, bj mat ttmenta of po*

CSO ^1

^H p[],419,4'i4,503

vilellinedmilatiou, Eu«>mbr7oof,d49 ^|

i^^^B bjr two »rit of niufioloi. SiM

i^«h, Dieetrioal, phenomdoa of, 370 ^H

^^^H Bjitbatl, inll a in million of, a/ter dtrUIon

Kliaurv, lotiglludlnnl, of brain aud iplnal

^^B of SIL p»ir, 43^1

copl. 361 1

^^H B/oltdt, fonnalion of, 62S

formation of. 623 ^M

Kinxurti of ]>Blalv, 1137 ^H

^^^B Fsu, toDJiiUvci norrca of, 434

I^Htula, ROHtrio, Dr. Bvaomont'i ease of. ^1

^^^1 iDOtflr nerve, 44lt

119

^^H devvlnprneat of, C35

mode of operating for, 1241 ^^

^^^H Fociul iiorve, 440

duodunal, 173 ^^^

^^^■^^ i>enKtbilily of, 443

Pcetal aliculntlon, firat form of, 048 ^^^^|

^^^^^^k influence of, on muitoalar xp]»nttuB

B»oond form of, 650 . ^^^^H

^^^^^^B 441

Follicl«9,or stoniatb, 117, 118 ^^^B

^^^^H noK*. 442

of LUlwrkOhn, IX. ^^^M

^^^^B ear. 442

\>f firunni^r's glandB, 136 ^^^^H

^^^^H paraljaiA of, 443, 443

UraAlUn, TtSO, bh2 ^^^H

^^^^^H FallopUn 1nb«f, 521

utvma.JiVS ^^^H

^^^^^M Ibmutloaof. 641, 1)44

Sit ^^H

INDEX.

661

Food, cotnpoaltlon of, 96, 97

daily quantity required, 97

effect of cooking on, 98
Fonunen ovale, 663

Talve of, 687

clfflare of, 667
Force, nerroas, nature of, 381
Formation of sugar in liver, 162

in fcBtuB, 633
Fossa oralis, 668
Fanetions, animal, 43

Tegetatire, 42

of teeth, 105

of saliva, 112

of gastric Juice, 124

of pancreatic Juice, 140

of intestinal juices, 137

of bile, 176

of spleen, 194

of mucua, 310

of sebaceous matter, 311

of perspiration, 313

of the tears, 316

Galvanism, action of, on muscles, 371

on nerves, 373
Oanglion, of spinal oord, 393

of tuber annulare, 422

of mednlta oblongata, 423

Casserian, 436

of Anderach, 444

pneumogastric, 446

ophthalmic, 498

sphe no-palatine, 473, 498

submaxillary, 498

otic, 499

semilunar, 600

impar, 500
Ganglionic system of nerves, 498
Ganglia, nervous, 354, 355

of radiata, 355

of moUosca, 357

of artioalats, 358

of posterior roots of spinal nerves,
362, 363

of alligator's brain, 364

of rabbit's brain, 365

of medulla oblongata, 366

of human brain, 368

of great sympathetic, 499

olfactory, 402, 473

optic, 364, 418
Gases, diffusion of, in lungs, 221

absorption and exhalstioa of, by
lungs, 224
by the tissues, 230
Gastricfollioles, 117, 118
Gastric Juice, mode of obtaining, 120

composition of, 122

action on food, 124

interference withTrommer's test, 127

interference with action of atsrch
and iodine, 126

Gastric Jnioe, dally qoantity of, 130
solvent action of, on stomach, after
death, 132
Gelatine, how produced, 48

effect of feeding animals on, 93
Generation, 611

spontaneous, 611
of infusoria, 514
of parasites, 616
of encysted entotoa, B18
of tnnia, 520
sexual, by germs, 524
Germ, nature of, 624
Germination, heat prod need in, 238
Germinative vesicle, 529

disappearance of, in mature egg, 570
Germinative spot, 629
Gills, of fish, 214

of menobrauchus, 215
Glands, of Brunner, 136
mesenteric, 161, 299
vascalar, 192
Meibomian, 311
perspiratory, 312
action of, in secretion, 306
Glandatn, soUtarin and agminatv, 145
Globules, of blood, 195
Ttd, 196

different appearances of, under

microscope, 196, 197
mutual adhesion of, 197
color, consistency, and structure

of, 198
action of water on, 199
composition of, 2U0
siie, &o., In different animals,
201,202
vihite, 202

action of acetic acid on, 203
red and white, movement of, in
circulation, 279
Globuline, 85, 200
Glomeruli, of Wolffian bodies, 639
GlosBO- pharyngeal nerve, 443, 467
action of, in swallowing, 444
Glottis, movements of, in respiration, 222
in formation of voice, 448
closure of, after section of pnenmo-
gaatrtcs, 461
Glycine, 163
Glyoo-cholio acid, 163
Olyoo-cholate of soda, 163

iU crysUlliiation, 161, 162
Glycogenic function of liver, 182

in foetus, 633
Glycogenic matter, 186

its conversion into sugar, 187
GoBSBLiN, experiments on imbibition by

cornea, 295
Graafian foUlrles, 530
structure of, 661

rupture of, and discharge of egg, 562
ruptured dnring menstruation, 556

^H 6B2 ^^^^^^tP

Bj^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^B

^^H Oroaflxn foIlli;li>s, ocinditton In fntiu al

Hunger and thlrEl, aontlnne aiter ditl- ^M

^^^1 l>4ti

aion of jitieuniogafltric, 4A7 ^|

^^^B Or&y flulMUiirtr, of nrrrout sy«t«in, 3S4

Hydrvgi^n, '1 iHplspeiueot of gaB«s in blood ^M

^^^1 of spinal coH, Xii2

by. 227 ■

^^^B of l^rxin, 'iHii

exhablion of earbonto add Id an ^M

^^H lu wRnt M irrttnbilit/, 401

atmosphere of, 230 * ^M

^^H Oreat Ji7-°ip''tt'*'^''=- "l*'^

Hygraseopla property of orguiie sab- ^H

^^^P ftDfttomj' of, 4ltl)

sLanoM, 81 ^M

^^^^^^ sonsibiliiy And exciubitit; or, SOI

BypogloMal nerve, 4(11 ^^^H

^^^^^H conncclion of, witb special •aiUM,

^^^^^M

^^^H

Imbibition, 289 4^^l

^^^^^1 dlrielon of, inflaenoe on animal heat,

of IE«iald«, by dlffinvnt llnnM. 9l^^^|

^^^H 605

by cornea. rk[<rritncnU on, 295 ^M

^^^^^^ on pupil kud eyelids, 506

Impnlfe, of bi«irl, 261 ^;

^^V tfttex notions of, ft(?S

IiiranI,ne«lr-bi>rn,L>harseteris1ie>af,670

^^H OubftTTimouluiu tp*tli, t!42

ItilUujiiiation of eyeball, aftdir dirision ^J

^^H funuiiui) of, ill lowur animals, <M3

of 5ih pair. 439 H

^^^1 OiLttatory iicrvL', 44(>, 4tiT

Infaaoria, fil3 ^H

^^H

diffHfent kinds of, r>14 ^1

^^^1 Hamhosd, Prof. Wm. A., on effeK-ts of non-

ooddUions of ili«lr produotlon, 914 ^H

^^^K [litcflgttnnua ilivt, 92

Schnllie's ezperimeot on gakanUon ^H

^^^H on jintdiioliim of urna, 327

of, &ie ■

^^B HatmiiliiK, St), 2<iO

iDKuIual bvrnla, oonitenital, £44 ^|

^^^1 IlAin, forinalion of, in emitrya, 627 ,

Iiijfclinn of plnccnlal stnuses from Tat> ^H

^^H Hsru'lip, ij3t!

sttU uf uturnf, 611 ^M

^^^^ ll.iiirBT, on motions of hsart, 267

Inorganic snbstanc«», aa jtroximate pri»- ^H

^^^V Uenring, stfiiRe nf, 48!)

riples, I>3 ^H

^^H appftratas of, 491

tlidr «>arce and dMlinatloa, 82 ^H

^^H tii&Ing; of Hith toncb, 4S4

Id CSC nla lion, of veins. 273 ^^^^|

^^1 Henrt, :i47

of capillaries, S7S ^^^^M

^K of Hah, £47

nurvus, 3M ^^^^H

^^^^^ of raptU«9, 248

Inanlivnlion, 107 ^^^^|

^^^^^H ins niiD« lions, 249

IrapoTlanoe of, 115 ^^^^^|

^^^^^1

fuuoUoo of, 116 ^^^^1

^^^^^H clmulatton of blood throNf^b, 2B2

Inspiration, bow aeomnplUbed, 318 ^H

^^^^^H souiiJii of, 252

morementa of gloUiB in, SSI ^^^^|

^^^^^H novonioiita

Instinct, iiatnre of, 426 ^^^^H

^^^^^^f

Integument, reapiralion liy, Z34 ^^^^H

^ dvrvlopiucut of, d-W

Uurelopiaeut of, 42? ^^^^H

^^K BMt, TlUtI, of atiimsls, 235

Intellcftnal pdwert, 409 ^^^^|

^^^^^

in animali, 42K ^^^^^|

^^^^^H how produced, 239

InlMtine, of fowl, lOl ^^^H

^^^^^^ incrMisifli bydivisionof sjmiwthetie

man, ^^^H

^^m nerve, 243, -'xiS

Joloes of, 133 ^^H

^^H Bernlspheres, nrcbral, 403

difoetion in, 133-143 ^^^H

^^H rpiu&rk&ble cases of injury to, 404

epitbatinm of, IfiS ^^M

^^^^^^ effect of ramoval, on pli!eouB, 40&

dlsappearmnoe of bile In, 17S ^^^H

^^^^^L elToct D( dieeafie, in man, 40t;

derelopment of, ttia, fiJ ^^^^M

^^^^^H coiupBratlTcisitoor,iudia«n)Ulract«,

luleatinal digestion, 141 ^^^^H

^^^H

Inteetlual Juices, 133 ^^^|

^^^^H fdnotlons of,

sotlon of, on Btarofa, 134 ^|

^^^^^^ (tevelopment of, i>22

Involnlion of utt-ra« «fl»r dellrory. ^9 ^H

^^H H«iuorrUai;e, from placttnta, Id pnrtari-

Iris, mo7eu<inla of. 41i>. 4$J. &*.>3 ^M

^^M

aftTtr diviiiou of aynipsUiello, SOS ^|

^^H Bepatic citDulaCion, 320, 321

Irritability, of gastriu niaoons membrane, ^H

^^^B duvulopmnnt of, iJliS

121 ■

^^H IlerbiToroas animal*, rsspiration of, 34,

of thv lieart, 2&S ^M

^H 223

of idumIus. 371 ^^^^1

^^m nrine of, SiA. 3:in

of norvM, 373 ^^^H

^^^1 Ileniia, ronf^enital, tUapIiraginaUo, 335

^^^^H

^^M uinbiltcal, r>.';u

Jaataox, Prof. Samnel, on dlgasUaa of 4^^^|

^^H in^tiltial, <i44

in inleslintr, 137 ^M

^^^1 Rippurain of *Oila, 330

Jaundice, ltI7 ^^^H

INDEX.

688

Jaondioe, jellow color of urine In, 339

Kidii«7S, peottUAritjr of oiroalatton in,
287
oUminKtion of tnediolnal mbBtanoea

by, 338
fomutioii of, 639
XcCBRiHnsTSB, experiments on prodno-
tion of t»nU from CTStfoerooB,
522
of oyxtlcercai from eggs of In-
ula, 523

IiwlirTmal secretion, 314

its fanction, 315
Uctotion, 316

variations in composition of milk
daring, 319
LactealH, 146, 151, 301

and Irmphatlos, 153, 301
Laijnx, action of, in respiration, 222
!n formstioa of voice, 448
nerves of, 446
. protective action of, 450
movements in respiration, 222
LassaioKf, experiments on saliva, 115

analysis of lymph, 300
Layers, external and internal, of blasto-
dermic membrane, 572
Lead, salts of, action in distinguishing

the biliary matters, 162, 163
Lbhhahk, on formation of carbonates in
blood, 60
on toUl quantity of blood, 213
on effects of non-nitrogenoQS diet, 92
Lens, crystalline, action of, 479
LxucKaBT, on production of cystloerons,

623
LiKBio, on absorption of difTerent liquids

under pressure, 292
Ligament of the ovary, formation of, 645
Limbs, formation of, in frog, 578
in human embryo, 626
Liver, vascularity of, 320
lobules of, 320, 321
secreting cells, 322
formation of sugar in, 182
congestion of, after feeding, 189
development of, 642, 658
Liver cells, 322

their action in secretion, 322
Uver-sngar, formation of, 162
after death, 185
in fcQtus, 633
Lobules, of lung, 217

of liver, 320
Looal production of carbonic acid, 230

of animal heat, 243
Local variations of cironlstion, 286
LoKOBT, on interference of albumlnose
with Trommer'a test, 127
on sensibility of glosso-pharyngeal
nerve, 444

LoHOR, on irritability of anterior spinal

roots, 386
Long and short-sightedness, 480
LoNOBT Ann MATTBveci, experiment <m
signs of electricity In an irritated
nerve, 380
LuDgB, structure of, in reptiles, 216
in man, 217
alteration of, after division of pneu*
mogastrics, 453
Lymph, 152, 300, 302
quantity of, 305
Lymphatic system, 151, 299

Haghds, on proportions of oxygen and

carbonic acid In blood, 227
Hate organs of generation, 640

development of, 640
Malpighian bodies of spleen, 191
HammallauB, circulation in, 249
Mammary gland, Btruoture of, 316

secretion of, 316
HABcn, on excretine, 144
Habbt, H., experiments on arterial pnl-

saUon, 267
Mastication, 105

unilateral, la ruminating animals,
110

retarded by sappreaiting saliva, 116
Meconium, 631
Medulla oblongata, 366, 423

ganglia of, 367, 366

reflex action of, 424

effect of destroying, 426

development of, 622
Meibomian glands, 311
Melanine, 67

Membrane, blastodermic, 672
Merabrana granulosa, 651
Membrana tympani, action of, 492
Memory, connection of, with cerebral

hemispheres, 406
HenobranchuB, size of blood-globules In,
202

gills of, 215

spermatozoa of, 541
Menstruation, 654

commencement and daration of, 656

phenomena of, 655

rupture of Oraaflan follicles in, 666

suspended daring pregnancy, 666
568
Mesenteric glands, 151, 299
MicHBL, Dr. Hyddleton, mpture of Oraaf-

lan follicle in menstruation, 556
Milk, 315

composition and properties of, 96,
316

microscopic characters, 317

souring and coagulation of, 318

variations in, daring lactation, 319
Milk-sugar, 67, 68

converted Into lactic acid, 318

^ 684 ^^H

^^H MolluK-a, uoTvoiiD nyftvin qJ, 3G7

Kervoui rilam«iit«, of bntn, HI ^^^^|

^^^B MootiK AS[> rKKSix-K, «>xperimGntfl on

of soiAlic nerre, 362 ^^^^H

^^^H ini)T(>niRnti> of hvitrt, 2&7

motor and scDsItiTv, 357 ^^H

^^^1 molitin, 384

KervDoa force, hov excil«d, 373 ^^^^|

^^^B Motor crnninl ntrvti, 433

natnre ^^^H

^^^H Motor ni°rvanx Elbre*. 367

mode of trans mission, 361 ^^^^H

^^^V Motor c>cuU rommuuiB, 4M

NerrnuB tieanti, two kinds of. 349 ^^^^|

^^^1 externuR, 4it^

.NorvuuB irrtUtiililr, 372 ^H

^^H UoremeuU, of otomRoh, ViS

bow frhown, 373 ^^^^M

^^^^ of lnte<!tin«. 147

dnrntlon tit, after death, 373 ^^^^H

^^^^^

•xtiaustdd bj vsoltMnaDt, 374 ^^^^H

^^^^^^h of vliutt lu rneplratlon, 21S

dMtrojred tjr woorara, 37-^ ^^M

^^^^H

ditUoot from museaUir, 396 ^^^^fl

^^^^H

natur* ^^^H

^^^^^f of fuitu«.

Norrooa sjrsuni, 347 ^^^^^

^ Uncosiiivi, ih

g«noral strootnra aud fbndiotuo^ '

^^H Udcmis folliolsN, 30!)

347-3«9

^^^^ Hooous iD^ml'nnc. of stomach, 117

of radi&ta, 35& ^H

^^^1 of inWHiiUL-, l^j-'i

of iDolIii!ti-rk, 357 ^^H

^^^B tonguij,

of artiiiiilata, 3&8 ^^^^|

^^H of nt«rDs, SOS

T,>rt^br»ta, 361 ^^^^|

^^B Ma«UH, 300

tkOkx acliuu of, 3&6 ^^^^B|

^^^H oDEupoaltlDn Had proportiea 0^ 310

Network, oapUlar?, la Perer'B gludi,

^^H of rauntli, l(i»

I4& ^

^^^1 of cvrvix uttri, G39

In wol> of froit's foot, S79 ^H

^^^L^^ Hosclm, irritnbilitr of. 371

in lobnlo of lirer, 321 ^M

^^^^^^L directl/ pnmlytvH by iiniphn-c^a-

Nfrwl,v-1>nm infnnt, iralgbt of, t>40 ^^M

^^^^^^B nide of pvtaasiuiD, 372

ruEpiraltoii in, G40 ^H

^^^^^^ oonsMit&neoas action of, 414

nervous phenomena of, 671 ^^B

^^V of mpirsUon, 218, 21fi

cOTnpnrntive siie of ornaiis in, 672 ^H

^^^K MufloaUr fibres, of spleen, 191

NBwroBT, on tumperataro of iMMts, SK ^H

^^^1 of lieart, spiral and circular, 259

Nllrlc acid, action of, on b)1»-p*gm«Bt, ^H

^^^^^ MuKiiUr irrlU)iiHt,v. 371

^^^^^^L ilurRlion aftiir dt'alh, 372

precipitation of uric acid by. 338 ^|

^^^^^^P «xbAii!it«d by re|i«at«d iiritatloti,
^^^^ 373
^^H Miiflcii)tn«, 16

Nitrogen, exhalation of, in resuinli^S. ^^B

224 ^^H

NutHlion, 4&-34S ^^^H

^^^1 Nails, fomtatlou uf. tii embryo, 627

Oblit«rBliDn, of ductus venosoa, 660 ^^^H

^^^H Nf:oiiiiER, on rupluro af CiranfiAii follicle,

of ductns arl«riosns, 6dS ^^^^^

^^H in mcnstraatlon, 550

Oculo-motorias DerT«, 434

^^^H Nonre-oellE, SS4

(Kophajnia, panljsia of, aftwr dlrubui ^i

^^^B Nerves, division of, 3.'i3

of poAamogaattto, 447 ^H

^^^K^^ inoeooUlloD of, 3ri4

deviilopin«nt ot, 634 ^^^H

^^^^^ Irritnbilit^ of, 3T3

(Eetmstlon, pbenomftaa of, S&3 ^^^^M

^^^^^H

Olttagtiiuus subslaiK-tis, 7" ^^^^^|

^^^^^m

in diir><rt!Ut kiuda of food, 72 ^^^^

^^^^^H olfactorv,

condition of, In the tissaoa and i

^^^^H

iiuid*, 73, 7« ^^

^^^^^B

partly prodac«d In ihs body, 77 ^H

^^^^^^B ooulo-moUiriiis, 4S4

decomposed In thii Uvl/, 78 ^H

^^^^^^^B pa 1 lie Li CI D II,

iuthobtood, 156 ^M

^^^^^H noior (ixtomas, 43fi

indispenmbla aa IngrmUeots of tba ,^H

^^^^^^H maMicntor, 436

fnod. 01 ^M

^^^^f 440

InsaOtiiioiit for notrjtloa, 92 ^H

^^^^^ hypoglossal, 461

Olfaotory apparatns, 473 ^^m

H apinal aiMiesaorj', 4M

protected by two sets ot niuselM, ft04 1

^^^^H trifHiat CStb pair), 435

oommiBBOres, 364. 43<l ^^

^^^^^B gloMo-pbarynRml, 443

Olfaotory Kanglia, 402, 473 ^H

^^^^^^B posumai[attri<% 445

thi*ir function, 403 ^^^H

^^^^^^B Buperlor find infi-Hor laryngeal, 446

Olfactory ncrres, 430, 473 ^^^^H

^^^^^^^E fn^at >jriiipittbKlic, 49d

tllivaTj- bodies, 36ll ^^^^^|

^ Jforrous filauioDts, 3&i>

Ompbalo m«a«ut«rie TMRdt. it^-4Si^^^^M

INDEX.

6 as

Opbtbalmio ganglion, 498
Optio gauglla, 364, ^IS
Optic nerres, 431

decasa&tioQ of, 420
Optio thalfttni, 402

development of, 622
Org&ns of epecial lense, 46&, 467, 473,
477, 491

development of, 624
Oi^anic substanoeB, 79

indefinite chemical composition of,
80

liygroHcopic properties, 81

coagulation of, 82

catalytic action, 82

putrefaction, 63

source and destioation, 88

digestion of, 125
Origin, of plants .and animals, 511
' of infusoria, 513

of animal and vegetable parasites,
516

of enofsted entozoa, 518
Ossiilcation of skeleton, 626
Ostelne, 86
Otic Kanglion, 499
Ovary, r.25

of tania, 526

of frog, 831

of fowl, 535

of human female, 537, 538
Ovaries, descent of, in foetus, 644

condition at hirtli, 646
Oviparous and viviparons animals, dis-
tinction between, 647
Oxalic acid, produced in nrino, 341
Oxygen, absorbed in respiration, 225

dally quantity consumed, 224

state of solution in blood, 227

dissolved by blood glob ales, 227

absorbed by the tissues, 230

exhaled by plants, 242

Palate, formation of, 637
Pancreatic Juice, 137

mode of obtaining, 138
composition of, 139
action on fat, 139
daily quantity o^ 138
Pancreatine, 85

In pancreatic Juice, 139
PA5IE1A, experiment on absorption by

bloodvessels, 148
Paralysis, after division of anterior root
of spinal nerve, 386
direct, after lateral injary of spinal

cord, 388
crossed, after lateral injury of brain,

389
(nclal, 442
of mascles, by salpbo-oyanide of

potassium, 372
of motor nerves, by woorara, 396

Paralysis, of sensitive nerves, by strych-
nine, 397
of voluntary motion and sensation,
after destroying tuber annulare,
422
of pharynx and oesophagus, after sec-

tlon of pneumogastrios, 447
of larynx, 449, 451
of muscular coat of stomach, 457
Paraplegia, reflex action of spinal cord

in, 395
Parasites, 516

conditions of development of, 517
mode of introdaotion into body, 518
sexless, reprodnction of, 518
Parotid saliva, 109
Parturition, 616, 617
Par vagnm, 445. See Pnenmogastrio
Patheticna nerve, 435
Peloosb, composition of glycogeulc mat-
ter, 186
Pelvis, development of, 636
Pb^ihock and Hoork, experiments on

movements of heart, 257
Pepsiue, 85

in gastric juice, 123
Perception of sensations, after removal of
hemispheres, 406
destroyed, after removal of tober
annnlare, 422
Periodical ovulation, 547
Peristaltic motion, of stomach, 128
of intestine, 147
of oviduct, 532, 635
of Fallopian tubes, 657
Perspiration, 312

daily quantity of, 313
composition and properties of, 313
function, in regalating temperature,
313
Pettenkofer's test for bile, 167
Peyer's glands, 145
Pharynx, action of, in swallowing, 447

formation of, 633
Phosphate of lime, its proportion In the
animal tissues and flalds, 58
In the urine, 335
precipitated by alkalies, 336
Phosphate, triple, in putrefying urine,

344
Phosphates, alkaline, 61
in urine, 335
earthy, 58, 61

in urine, 335
of magnesia, soda, and potassa. 61
Phosphorus, not a proximate pritaciple, 47
Phystoli^, definition of, 33
Phrenology, 410

objections to, 411
practical diflioalties of, 412, 413
Pigeon, after removal of cerebrum, 405

of cerebellum, 416
Placenta, 605

TSDEX.

Placentft, rompurntivs miatomr of, GOf<

foTmatinn or. id buinan ipeoies, 607

fffilAl lufts of, GOfI

tiiat«>ri)«I slnnseB of, 0O9

Injection of, from uterioe vanflb, £11

fiuaction of, iIIZ

Re^arNtidu of. in dulivwrj, C17
I'lAcentaL cln'nlAtlon, e.W, 652
Haut*. vitNl liiMit of, 238

gttBumtivfi ft(>i)antnii of, S24
llMtiu ci( th« liLooil, 2i)5
Ptipiitiii'ii itd>], 'J2II
PnoamngMtric itiirvo, 44l>

it« dUtributinn, -Mli

Holloa of, on pharjrnx And ntoplui-
gna, -14"
oil Idrjrnx, ■14K
in fnrnintioit of Toio«, 449
In respirnliun, 4Gl>

effect ol iU disision, on reipiratory
moTvneuta, 4S1

oaoM of death after dlrlalon of, 4SB

influence of. on cnaopbagtia and »\0-
much, 4*i7
PnsEtmogasirio nngliu'ii, 44^
FoonuA, on gljrfiogatiio uulter In bat-

chef'anvat, 1B7
I'ons Varolii, HilJS
Portal blood, ijusntitr of flbrin lu, 203

t«inp«<riLtiire of, 'i4-l
PorUl vein, in liver, 32ll, 821

develapment of, G&8
Posterior columns of spinal oord, 387
Primiliv« Irace, 674
ProducUan, of sugar in liver, 182

of CArbotiic aclil, S28

of aniiii<il Ijeal, 339

of uniiL Lti blood, 32^

of infukorial AnlniaIonl«9, M3

of anitugj aud vo^uUblu par&Blt«B,

Proxtmntv princlptu, 45

duliiiiliun of, 47

nodo a( i-xtrtictiOTi, 46

manner of lli«ir niMHKiation, 49

varying proportions of. &0

three diKtinrt c1ax«M ot SI
Proslmate principle* of tb« first olasa
(inorganic), 53

of tlie aeoond claaa (cr/»tallixable
■DbBtan<.'«e of orgaaio origin), (i3

of tho third claas <orgiuitc sub-
slam^t^ii), 79
Ptyalino. IflS
PabeHy, period of. 643

sigua of, in feuinlc, JS4
IhllBillOD, of hnart, 252

in living animal, '2.SS

of arterfKi. 2<i4-268
Pupil, action of. 4I!I. 484, 902

RontiacliAii of. atlnt division of ajin-
patlicllc, .'i06
Pupillary nrtubnao, tj24

ralrefaction, 83

of the uria4>, 341
Pyramids, anterior, of idciIqIU oblOB-
gala, 3tiG

Qoanlity, daily, of wat«T axhated, H
of food. 91
of UllTft, 112
of gaalria jntca, ISn

of tMUtcrsaiicJsloe, 136
of bilo.

lo,I7W

of air ONwd in r««piration, 230
of oxygtfD used in respiration, 324
Iff carbonic a4-id exhaled, 232
of lymph and chyle, ati2-3<»5
of flaids iecrotod and reabM>rbad,30S
of mnturjal absorbed and diaoliatgtd,

345
of p«n<pit»tlon, 313

of urine. 332
of area, 327
of titat« of aoda, 330
Quantity, entire, of blood in body, SI

Rabbit, brain of, 365

RacM of men, differwnt eapaoity of, for

ciTiliiation, 409
Riuiintn, nirroiii Hvatpm of, 35S
Rapidity of circulation, 2^4

of Ininsinifliion of nerrooa foree,
378. 379
BtMtions, of curcb, ti

of sugar, t>S

of fa^ 71

of B&Ilra, 108, 109

of gastrie Juice, 123

of Intoettaal Jnie«, 136

of paQoreNlloJaiati, 139

of bills ISS

of uiuau>, d09

of iuillE,3l7

of urinv, 33tl
RMSCDiug power*, 4i}7

in animala, 428
Rod 9lohul>*s of blood, 195
ReBex actiim, SSd

in ceiilipcde, 3St)

of spinal caril. 392

of medulla oblongata, 4S4

of tuber annular*, 437

of brain, 428

of optlo liibtsr*lM, 41!>

in nwwly bom liifani, 671
Rflgcneratiou, ol utniuo mucooa n«fB-
bran^ after prefnanoy, 618

of wall* of otvru*, i\9^tF2f)
{EBaHAri-T A5n Brisbt, on ab«oT^tioD bf

oxygen, 225
Ekiu. br. Johu, expvrtiDvnt on enulni{

of atroama in fdctal hoart, tiSft
Reproduction, 209

nature aud object of, S09, ftll

of pataaitea, &U

INDEX.

687

Bepradaction, of tnnia, 520

by germi, 621
Beptilee. circQlation of, 248 ,

Rospiration, 214

bj RlUa, 215

bj langB, 21(1

by Bktu, 234

changes In air dariiift, 224

changes in blood, 225

of newly bom infant, 670
Respiratory moTements of oliest, 218

'Of glottis, 222

after section of pnenmogastrtcB, 451, ;
453 '

after injary of spinal oord, 425
Restiform bodies. 367
Rhythm of heart's moTements, 261
Rotation of lie'art daring contraction, 260
Ronnd ligament of the nteras, formation
of, 645

of liver, 660
Ramination, movementa of; 101, 110
Rapture of Graafian follicle, 552

in menstroation, ^56
Ratting condition, in lower animals, 553

Saccharine sabstanoes, 67

in stomach and intestine, 134

in liver, 182

in blood, 189

In urine, 339
Saliva, 107

diffKrent kinds of, 109

daily quantity of, 111

action on boiled starch, 112

variable, 112

does not take place in stomach, 113

phyaical function of saliva, 114

quantity absorbed by different kinds
of food, 116
Salivary glands, 109
BalU, biliary, 160

of the blood, 207

of urine, 335
Saponification, of fats, 71
ScuARLiiia.ondiumal variations In exha-
lation of carbonic acid, 234
ScHDLTZE, experiment on generation of

infusoria, 516
Scolopendra, nervoos system of, 358
Sebaceous matter, 310

composition and properties of, 311

function of, 312

in fffitns, 627
Secretion, 306

varying activity of, 308

of saliva, 109

of gastric Juice, 120

of intestinal jnice, 136

of pancreatic Juice, 138

of bile, 170, 319

of sugar in liver, 1H2

of mucus, 309

Seoretion, of sebaceoos matter, 310

of perspiration, 312

of the tears, 314

of bile in foetus, 633
Segmentation of the vitelloa, 571
Seminal fluid, 640

mixed constitution of, 644
Sensation, 382

remains after destruction of hemi-
spheres, 406

lost after removal of tuber annnlare,
422

special, conveyed by ppenmogastrie
nerve, 424, 448
Sensation and motion, distinct seat of^ in
nervous system, 384

in spinal cord, 387
Sensibility, of nerves to electric current,
373

and excitability, definition of, 364

seat of. In spinal cord, 387

in brain, 401

of facial nerve, 443

of hypoglossal nerve, 461

of spinal accesBory, 459

of great sympathetic, 601
Sensibility, general and special, 462-466

special, of olfactory nerves, 430

of optic nerves, 431

of auditory nerves, 431

of lingual branch of 0th pair, 440

of gloBSO-pharyngeal, 445

of pneuroogastric, 446
Sensitive nervous filaments, 357
Sensitive fibres, crossing of, in spinal cord,
389

of facial nerve, source of, 443
Sensitive cranial nerves, 434
Septa, inter-aurioular and inter-ventrl-

cnlar, formation of, 663
S£4[iABi>, on crossing of sensitive fibres

in spinal cord, 389
Serum, of the blood, 209
Sexes, distinctive characters of, 526
Sexless entozoa, 51S
Sexual generation, 524
Shock, effect of, in destroying nervous

irriUbility, 372
SiEBOLD, on production of tteuia from

cystioercus, 522
Sight, 476

apparatus of, 477. See Vision.
Sinus terminalis, of area vasculosa, 587
Sinuses, placental, 609
Skeleton, development of, 625
Skin, reupiration by, 234

sebfteous glands of, 311

perspiratory glands of, 312

development of, 627
Smell, 473

ganglia of, 402, 473
I nerves of, 430, 473
I injnred by division of 6th pair, 438

^^M 688 ^ IKDEI, ^^^^^1

^^^B fiuiTii. Dr. SoutbwtjFjd, on catioeanfl and

Sagar, compoKlliou at, i$ ^^^^^|

^^^H pnlmoiiary exliAlnclon. 313

iRSts for. tiS ^^^^1

^^^H SoUr pl»<xu« of Bjriiipathetic iierre, SOU

r^nnvntatioi) cif, 69 ^H

^^H Solid bodtes, vialoa d{ iritli lira ef ea, 486

prcpDrlioiL ill different kfnda of fii^_^H

^^H Soaoda, of ItearU 252

Bfl

^^^^L^^ hoir prodiict-il, '2!r3

Boorua and destination, 70 ^^^^^^

^^^^^^L VfKtnl, linw produovd, 448

pnMlaced in liver. ISi ^^^^

^^^^^^P dotlrojred hy «»c(ian of inferfor la-

dIacbatK«d by urine in iliaeaae, 339 ^

^^^^^^ rjiigMil Derrutf, 44B

Sugar In liver, fonoatlon of, 182 ^h

^^^1 of Apln&l Kcoeuory, 4S9

]ii!rc«nta$e of, 184 ^^H

^^^1 Bonudii, »cuUi xnd ijniva, tnmamttled hy

i>roiluc»d In bwpatic tiBane, IS& ^^^^H
iroin glycog»aiD inatlt-r, 186 ^^^^H

^^H luoinbmiA tj'tupnuf. 492

^^^1 Hpocinl srnMii, 4ii2, 46i

aliiorhed by hepailc blood, IM ^^^H

^^^H Spi^civiL, mndr of coitliuDiilian, Stl

doowmpoand ill mrculatiuD, 169 ^^^^H

^^^H Spermatic dukl, !>44>

Snlphatra, alkaline, iu urine, 334 ^^^^|

^^^1 miKrcl MmlilntiAa of, .144

Sulphur of the bIM, 1G4 ^H

^^^H Spa mi a tot tut, 54l)

not dUobarR"^ ''"b ibe fecM, 17B ^H

^^^B moTiimonU of, M'2

Svallofing, llti ^^

^^^H runoalioD of, S43

Totariled by suppresAion of aaltra,

^^H SplDS biQdk, 025

115 ^J

^^H^ Spinal scoamorj. 458

hy diviaion of pn«utno^itrie, 457 ^H

^^^^^^ 8»Dsitiili(jr of, 4Sfl

Sympatbelic norre, 496 ^H

^^^^^H oomnBtinlcatlon of, with pneamogna-

its dhtribaitoii, 4D!I ^H

^^^^V *^

aenaibility and ezclubilily «f, £01 ^H

^ influence of, on larynx, 4A9, 400

luflnonoe of, on >pecial aenaw, MX ^H

^^^1 Spinal column, fonaatlon of, 07&, 625

on pupil. 502 ^M

^^m BjAaaX oonl, 3K2-4()ll

on nutrition of eyvball, 439 ^H

^^^^ oouaifnum of, 362, 343

on naaat paaaagM, 504 ^H

^^^^^^B aiiipHor. and pnsl#rinr colnmiDi, S63

on car, 5W. 505 ^^

^^^^^^H oritfin of uitvith frniii, •'Ilr'2, 3ltS

DM ii-aip«rattira of panicnlar

^^^^^H B«n«iliility aud cxoilabtlitj of, 387

pans, 50* ^J

^^^^^H crn»Rpd Auflon of, 3*^6

rcOvx acliona of, SOS ^^M

^^^^^^^H ri>fl«x cf, 3112

^^H

^^^^^H proteclive actfon »(, 397

Tadpolff, d4■v«1npI)ll^nt of. 570 ^H

^^^^^H litDnenco nil «pMnctcrs, 3IIS

transfofiBBtion Into frog, 5*0 ^H

^^^^H efrecl of injury In, p*JH, 399

TiBOU, 520 ^n

^^^^^^P on re»piralion, 425

prodaoed by nelamorpltoiii of eys-

^^^^^^ funnation of. fn embryo, 67fi, 62&

liM>rcn<i, 532 ^J

^^^V 8pin»t nervvB, origin of, 3tt2, 3t!3

sIiikIm arlicuUtinn of, 525 ^^H

^^H Bpleen, 190

Tapeworm, 520 ^^^^M

^^H Malpiitliian bodies of, 191

mode of generation, 521 ^^^^H

^^M extirpation of, 193

^^^H

^^^B BpontantfouH generation, fill

norvoji of, 14<>. 444. 467 ^^^H

^^K^ Slaruh, fl3

oondltlfin* uf, 4fi9 ^^^^|

^^^^^^L proportion of. In dlffereal kinds of

liij u ry of, by paralysifl of facial ««n^«^^H

^^^^^^1

^^^^^^1 of, 04

Taurine 1(!4 ^^^^H

^^^^^^P reauiloiiii

Tauro-«holal(< of aoda, 163 ^^^^|

^^^^^^T Action of saliva on, 112

Diii-r>]riL'Opic chBr&ot«ra of, IttS ^^^^H

^^^^F dipwHiioH uf, 134

TauTo-dholiv acid, 104 ^^M

^^^P StarO.tb, ultvous ayftlem of, 35S

Tears, 314 ^^^M

^^^P 8t«rpfl?rope, 4>7

fonction, 315 ^^^^H

^^^M Bt. Martin, cbnb of gsHtric n«tola In, IIA

Teeth, of swrpeiit, 105 ^^^^M

^^H Slrabisuus, afl«r divji^jun of motor ooult

0) poUr bear, lOti ^^^^H

^^^1 cAininunl*, 4:).l>

^^^^^1

^^^H of iiiut<>r vxinrnua, 435 ^
^^H BtHat^d txylii-:«. 403 *

of man. 1U7 ^^^^|

ltr«t and aMond 9«ll of, «72 ^H

^^^H Bublingual ^Itind, vetirettin of, 109-110

Tffmpvralare of the Mood, 236 ^H

^^H dubmaxfllary KaDglioii, 496

iif different riped«fl of animal*, S37 ^H

^^H gland, aeumtinn of, IKS

of ihtt h1oi>( in difliiraut oi^»n«, 344 ^V

^^^P SudoriparouR gland*, 3LS

•IwAiion of, after avctiou of tyia\»- \

^^H Sugar, 67

tbatio n*rrc. 244. 61*5 ^t

^^^K TaHellei af, 67

Tensor tyiupani, aotioD of, 492, SM ^^M

INDEX.

6»9

Testa, for sUmh, 66

for Bugar, 68

for bite, 167

Pettenkofer'a. 167
Testicles, M3

periodical aotirit; of. In RA, 545

deTelopment of, 640

descent of, 641
Tetanus, pathology of, 394
ThaUmi, optic, in rabbit, 366

in maD, 402

fnnctlon of, 403
Tboracic dnct, 153
Tbonoio respiration, 42S
Tongue, motor nerve or, 461, 467

sensitire, 440, 444, 467
Tricbina spiralis, 61S
Trionspid ralTe, 2fil. See Anricalo-ren-

tricnlar.
Triple phosphate, in patrefjlng urine, 344
Trommer'fl test for sugar, 68

Interfered with by gastric Juice, 137
Tuber annnlare, 422

effect of destroying, 422

action of, 423
Tabercula qnadrigemlna, 364, 368, 418

reflex action of, 419

crossed action of, 420

development of, 622
Tubnles of uterine muoons membrane,

699
TufU, placenUl, 609
Tunica vaginalis testld, formation of, 643
T/mpannm, function of, In hearing, 491

Umbilical cord, formation of, 616

withering and separation of, 672
Umbilical hernia, 630
Umbilical vesicle, 580

in human embrjo, 681

in chick, 688

disappearance of, 615
Umbilical vein, formation of, 652

obliteration of, 6t>ll
Umbilicus, abdominal, 576

amniotic, 684

decidual, 601
Unilateral maatioation, In ruminating

animals, 110
Urate of soda, 329

its properties, source, dailjr qnantitj,
Ac, 330
Urates of potassa and ammonia, 330
Uracbus, 631
Urea, 325

source of, 326

mode of obUinlng, 326

conversion Into carbonate of am-
monia, 326

dail/ qaantltjr of, 327

diurnal variations in, 328

decomposed In putrefoction of nrine,
343

Uric acid, 329, 336

Urine, 331

general charatter and properties of,

332
quantity and specific graTlty, 332
diurnal variations of, 333
composition of, 334
reactions, 336

interference with Trommer's test, 337
accidental ingredients of, 338
acid fermentation ef, 341
alkaline fermentation of, 342
final decomposition of, 345

Urinary bladder, paralysis and inflam-
mation of, after iojnry to spinal
cord, 399
formation of, In embryo, 630

Urosacine, 87

Uterus, of lower animals, 637
of human female, 638
macons membrane of, S99
changes in, after impregnation, 600
involution of, after delivery, 619
development of, In fcetns, 644
position of, at birth, 646

Uterine mucous membrane, 598
tubnles of, 699
uonvenion into deoidoa, 601
exfoliation of, at the time of delivery,

617
Its renovation, 618

Valve, Enstaohlan, 663, 664

of foramen ovale, 667
Valves, cardiac, action of, 250

cause of heart's sounds, 253
Vaaa deferentia, formation of, 641
Vapor, watery, exhalation of, 66

from lungs, 224

from the skin, 313
Variation, In quantity of bile In different
animals, 171, 174

in production of liver-sngar, 184

in sl»* of spleen, 190

In rapidity of coagulation of blood,
209

in siie of glottis in respiration, 22i

In exhalation of carbonic aold, 232

in temperature of blood in different
parts, 243

in composition of milk during lac-
tation, 319

in quantity of urea, 327

in density and acidity of urine, 332
Varieties of aUrcli, 64

of sugar, 67

of fat, 70

of biliary salta in different animals,
164
Vegetable food, necessary to man, 90
Vegetables, production of heat in, 238

absorption of carbonic acid and ex-
halation of oxygen by, 33, 242

^^^^^TW^^^^^^^^^^^IKI>BI^^^^^^^^^^^^^^^^H

^^^H VegelaMe pHriiaIt«a, MQ

Vital pliennmt-na, tlieir oalaro huA pMn- ^^M

^^^B VegeUlive fsnctbiis, 4i

liariiies, 3B ^M

^^B Velaa. 272 \

VitollUB, yZ'S ^M

^^^K th«Ir miabmce to prvsvaro, 273

■ejjRientatlon of, 571 ^^M

^^^^^^ abBorptlon hy, 1-18

fornuitlon of, In oT&rj of tetni, MS, ^H

^^^^^^^1 aaliuu ill, 27&

■

^^^^^B motion of \AimA through. S73-27ft

Tltvltlnv circulation, M8. 6*9 ^^^M

^^^^^H mpiHitr or cir«n1nti(^n In, 276

mvmlirnni', ^i^K ^^^^H

^^^^^^H araph&lo-tnoKvDleriu, l!4!J

aphurpi, .071 ^^^^H

^^^^^^M ninbilioal,

VocaI founds, li«ff produced, 446 ^^M

^^^^^r vertabrnl.

Voloo, fominlion nf, in larynx, 448 ^^M

^ V«llieoftvai, fonniitlnn nf, 4!lti

l«t, after division of spinal acm*- ^^M

^^^1 poBtlton of, in Uotae, i!U3

S017 nerve, 449 ^H

^^^H Vena nty^m, aupt^riar an<i inferior, far-

VoUlipn, fl«at of, in 1ub«r anttnlsra,422 ^H

^^H matlou or. SS7

VniDlting, pwoQliar, aft^r division of ^H

^^^1 Venoaa ayslem. ditv<-1flpTn«nt of, CSA

pneatnogaslrics, 45? ^H

^^^H VvnUiiilvii of lintirl, Kiii(;l« in Q»b and

^^1

^^^^^ reputes. ^7. 24S

Water, as a proxIiDat« principlo, 53 ^^M

^^^^^^k dflnhle in birdft and in&mTiialiaiis,

lU prnpnrtion In the aniiuat Uubm ^H

^^^^H

and dnidH, U ^H

^^^^^m sfluaiiou of, 250

lt« louro*, 54 ^H

^^^^^^P Mntnotion unA rvlaiMJon of, 2&6

mod* of dfscliargo tnn ihw tMidy. &S ^H

^ sinngAllon <leiring cnnlnitlign, 257

Wdgbt of organs, ci>ti)itaratir«, in nawljr ^H

^^^H miii>culfLr niirot uf, 200

bom infant ami fn adult, 672 ^H

^^^H Vernix ciuHisft, 1127

Whil« globniM of the blood, 202 ^H

^^^K Tert«l>mta, nervous Bystem of, 360

aotioD dC aosUe acid on, 203 ^H

^^^H Vertebne, fonu&tioii uf, biS, 6i&

Blui;i;I«h roovemont of, In etreula- ^H

^^^H V«sic!(-ii. k'll)'OB«>, 74

lion, T,9 ^M

^^^1 puloioiiary, 217

Wblt« iiuhgUuoe, of nnvouB lysleiB, 3A0 ^H

^^H aAmliiDl. &44, G-13

of Schwann. 350 ^H

^^^B V«>ivul» seinlnaltfi, .'>44

of Hpiual i-ord, 3i33 ^H

^^^H foraifttlou of, ni'.i

of brain, inBcnilble and InozcltaUs, ^^M

^^^B VinarlnuH urcrwlioii, nAn>«siat«nR« of, 307

401 ^M

^^^V Vivariou* intrnttrustivn, uAturu of, S07

Witbvriug and fvpartilloo of umbilical ^H

^^H Villi, of intoitin«, HiS

cord. *rt«r birth, 673 ^H

^^^H ahsorption by, 147

Wolfllan boHie*. C38 ^M

^^^H of ulioriun, 591

Btrat;lure of, 639 ^M

^H VKion,

Atropliy fliid disapp«araDO» of, 643 ^V

^^H goTiglia of, 3rA, 418

TesCl|i«4 of, in sdnlt fvtoalv, &45 :

^^^B nerves uf, 4111. 477

WvHAX, Prof. JefTrles. on cranial B«rrei ^J

^^^H »i>i]aratus uf, 477

of Raua plpious, 433 ^H

^^H dlbtiuot, at dilToront dlfttanoad, 470-

^^M 4H]

Y«llow «olftr, of orin« in Jantkltir, SXl ^H

^^H rtrvis of. 483

of corpus Infpuia, ^113 ^^M

^^^^^H of aoliil bodies niLk both fiyiw, 486-

^^H

^^^H

Zona pellaeida, 5S8 ^^H

^^^H TUB

^^H

BL.ANCHAKD ft LEA'S M&VICAL

Wherever KeMMkarr- Ittwanowb^MimtMl rrfulkrly Tor nwrviiMn rmTT ]rt«ra.*aJllkwlai«
under lt>« rimiriilol' Ihr prF>*-til cililiir lot nmrr Ihui ii iiimrlrr »! ■ remtmrj/. TfeTM^rtMt U«
ItiMC period, it hvK tninniaiiM-d ilBiti(iH la ilt« bi^tH^ ru:ik ol n<-<IK-«l fowojle*!* Wtfc H hA>

CoilibomiDrB will l» rtxintl In r<>«ii»m • W^v ninotxc i>f ihe mi)*-! iHpIhikuIvImnI Maat «f lli> |r»
r«Hl«i iooeiy occtien of ihe United Si bic*, rrndnrmftk* dt(wnai«ai amtedto

ORIGINAL COMMUNICATIONS

rtill«f vu1e<l and [mporlHit niaitcr, of feni mlt-reil toall pivciiiKwen.

A« tba ■iw t^ tii« JiiurMal. buwcvor, is u> ou«bitui ibn advuiugo ptcflvaiisd bj ail tka AIna
*ari«tiM ol peliiMlicals. IB ll>

KEVIBW DKPARTHSNT

will bar<Nintlmrtiilr4 nod imparlial tcvIew* nf at! impottanl oew woriu. p«tac>iMHlrt|i3U«t
aoTaliy and microt, logctlwir wiili very nunwraiiB

BIBLXOaRAPHlCAL NOTICBS.

iBdudini: ncart)- all llie mectiMl publiualtoaiioflbc day, botli in iktvcoumrf tuidOtvai BrtMl.v4
a ciLuiee »eleciiau o< ilw vi«ie imiKiniuii i>onliiM(ilB) viortci. Tltia U A>llowed by (fee

QUAHTERLT SUMMARY,
Ming a rary lull aad r-omplcw ab»irn«l, mvibodivAlly tmaf/ti, af tha

inptuivtfiDfiiiTs m DiscomiBS n tub irdicu icicicn.

TklR d»paniBi'iiiL>f 111* Juuruat, •« uiipurtaiit lo tUc pru)ti*iiw| phvuruui. i* iJmi obfnM att
eanr uii itir iwr) i>r Ihn nliiiic. Ji i* i-lD»ilMHliiiiJBrciuigeJ inuleitiii' . I*, likv* IWdMI^

ih<* re>rurrni:> lit ihc reiulcr id piiiiuii ut iKiitiiulur i>ub;FCIi>. and ' 1 1 to prwM ■ *W]

lull and uctiiiiafcdiHcM ol all ulwervB lions, uitcuTrrirh, and luvmli'.'i > ij in ««*ry hrtaa^d

madirnl i^j<ri)n!. Thai vrijr aluaairc amiii|p;aioBl» ol Utr pHbliabc;*. ate ausii aa iv irfoalbUi
aditur rvinplrlr niaionalp Icr iliii> purpute, a* he not oaljr trfMlaily rovetwa

ALL THK AMEKIOAN MEDtCAL AND SCIENTIFIC PERIODICA!^

hut alr.ilwvnty ur tlilrty ol itie toon imporianl JomaaUiMied In Urcar Htnm'B aad tMlteCsau-
nciit, thut) «tiuti:nc mm lo pnwinit ib a uwveaMat campBM a Ihorouira and »Mn|Wirta ri^tn^W
eTeryiliini miem'Uii^or inpoMaoi I0 iba plinician ooeumay la aay pafi uniiB tnviUasd wefk.
Tu ibcir old kUtii-ritxTK, nwuy ur whom oavv bern on ihi^u li>i for (wmty or llurn- fn

Sublisbi^ri: f^l ihui ito pmmi^* fur the fuiure an; n^rvinarv ; but itipoa wIm nwy MNTi
r*i itiiip tv »iil<vrit>r ran rrni a<«.iiml Ibai no eivrtkui wiH bv «f«fcd tO nuUMua ite
ths kigb pWAiiioD wbioh It baa ovcupivd liOf io luog « [asriod.

Byrctrretic« to tbe l«fm» It will be w«iiihnl, in addittco lotKUIarie annual at

Jrttciiml taliinriAtiim «n «ve^^■ bnuivh 01 uiediCHi >cwocu, Uia aidwcriLer, by f^yu^ ta
ooDOOeK enitilod, wilboui furliwr churKC, \o '

THE MEDICAL NEWS AND LIBRARY,

a ntanlbly penoili<-al o( ibiny-lwo largo oriavo f^: It* >'Ntw» l>ar*aTm>vT' ,
curr«iil laroniiutjvii ul [he day, wbilc tbit '• LiasAay UcrAKTMiuaT" irikvuicid lu |naw'aiwi
wd wurii» •in Vftriwu» brauclin «( ai«difiiw. Wttkin a l'«vr Vcttri>. ••il>Miiian ba-rs ibM n«
withoui rxpviiHc, many works of iliv hiihirai oliiracior ihmI iwavinnii valH«, Mipii ^x Wi
Prsctlvft," "TudJ Hiid Bowraaii') l'Ii>> ml L«y." " Maifat^na'a tUtr^atJ," " Waat tm Cto
'> Wot uD FeuialVT, Purl 1.," ■• IlHlie'->(ii)titMi (tie AliiDriitAry Canali" "SlBp««ai
Wtel« ib« wuik Bl }KtM«al ^ppemnag in iia oalonD*, eownmoiBg Jasmrj 1« mM. !•

ASTEHA; its PATQOIOUY. CAdSBK, rON&E(irE?(CE&, iXD TIElTIQIt

BV H. II. SALTiiA, JU. U., !• . U. S , &«

TbU wnrk, the r*«ult of tnurh cxpeririuw in ih« awac«a>Hil pT a cwcwnoa mi exmwJtadf I
irarlBlilv di<wa>c, t-aii tiardiy (ail lu give >ali>raflioa to 4ijlMcrlbef<, aiid lo Biaial«tll tka n
Obaracitr ul lac valuable Mrfivn ut buuha Wbwb UVe npftesrcrd in tba paf** ofttte "Slwt '

Mi;^

li willtJiiwibeMMMifaatrorlbei>nBllii.iiiso4 FIVE D0LLAK8,pudlaMlTma«,(Wi
frill .ibuiii a Quarterly and a MuuLbty pcriudioal,

EMBRACING ABOUT FIFTEEN KUNOREO LARGE OCTAVO -ffcEES.

Tbi>*r ■abaiN-ibt-r* who do nut pay in advanirc willhvar in niiiid tBal ikeir aa^^nptM
Oo/tar> will eulillo Ibem lu Ibe Juurnat only, wjihoat th* Nrwa, BndlbBlilaey W^l be alii
«J Ihcir »wi) iK.Mufi: "II Ihr reoeiplol i-acti aumlicr. Ttie advaMta^vf •
in^i Ilia JiiuriiikL will ihii> !« appamnt.

KftfulianucsKl^-uliMiiipiianaOBn be nailed at ournak, wbea«iwntAist« Mi
nnimibkiibe iAati«y tBduly mcliwedaiuirorwBrdrd.

Addrua BLANCUAKU ft I.BA. Psoamweu.

AoMibBfa*

AMD 8C[l£»TiriC PU BL10ATI0H8.

ASHTOM IT. J.»,
Sarron to IIib BUalieiia OiBpcBHry, to.

ON THE DISBASES. iNJUiUBS. AND MALFORMATIONS OF TK8

HECl'LiAl ANU ANIj'S; wiih n:niBi4«oa (laAitnal GimMipaiiun. Frmo Ibn ihifd uiidenia/^d
I^Ddoa ediiKHt With hmi^Ujmr itlu*tr«tKNu. In »na very beaaiiluUy |irtaleil t^uvu vulumr,
of ftbuM 300 psgwi. {y«ut /'<iM^. I « J DO.

VVa nr* (aiiaiinJ, afinr m dtrofal vninlnttiim o<
Ui« Ttitum«, *nJ k Mmparmm of ito cihmhIi with
iJiOOTuf iMlBdiaiiBrciiaoaMuraaMlc-iaHM^nrKM,
UiklUekcAl wa) fwf tka raadw luav«il kuoaolf of

III* mcpIImii Kilrii^c gfrMi la the «oaplailiBf f*'**
l[ra|>h atHxn, WMRld ba l« priivide hlwiaf^r With A
c ipy ••r <ac l>>i<j)i rri>ai wlxi^i ii kaa Ow* laliaii, aail '
ililiKnnlW (II ann lis inii'itclivn imvm Tlioy may
(v<ji« lu iii<n in in r a Iniiuipiii amllatveatbkMUf .—
Am. Jaaraof Ut4. Sfi4»t»:

ALLEN (J. M.>, M. D.,

Fraf^MAr of AMtoniT )■ Ikt PeB»>y)visia.M«4ieiilCMl(>Ka,Afl,

THE PRACTICAL ANATOMIST; or, Tiie Studeot'^ Giii<ie in the Diawetlng.

RUUM. Wiih 2M illoairationa. In one anaitoain royftl \2m9. tdIuiim, of over DOO p*goc, lea-
tbei. SV K^.

Wa t>«lieT» It t« b« oat of lb« lauti aaeCul WMkt
• nan tbe aub)eoi aT«r wHImd. It ■• hinJuiinrU
tilu»al«d, wall Jirlnlad.aDCl irill UelnuuU ut i:iu-
trantaei aixe flit a*a in ibc iltaaagimg-Tiumi IHt4

Howcvai valiiablB atay b* Ik* *' OiaaMtui'*
Owfaa" Wkieft m, of IbU, bave ha^ orcaali)* tu

notice, we r<>l acinEdriit tliat liie wcjik of Of. Alt«K
II tupwii-it t-i aof 111 iriem- Wa Svliwa wiih lli«
aulli<.<r, tbul Biiiie ■• tu fullf iilutlrateil aa tlm, aad
ihi< ii(r«ii|i«fii>>ni "( thx wotk la *ii<>i] at in fj<ih<aM ',
(he lalriHi 111 llic liuileBt- tVc in'>«l CiMilidI) i» i

eutBJHoail a lo iHciiatualiuft.— H'««HrmJL.B4u(,

ANATOMICAL ATLAS.
By Profosaora H. H. Snitu anJ \V. K. HoaNCB. of tlie Uoivaraity of PeaosjK

vuik. 1 Vol. 8va., extra clufh, will) noarlytlVI iliiiMraituoik. [?* Sec SxirN, p. 331

ABEL IF. A.I, F. C. S. AND C, L. SLOXAM.
HANDBOOK OF CUEMISTRY, Theowtical, Practical, and TwhnioAl; willi «
RMxMniiwiMtaMry Pm^Mw t>v L'r llorMANH. In one torgv vciavo *otua«, wctra el<Mli, vT WQ
piy, wiib (ll«Mr«iiiiBa. #^ 4!).

ASHWELL (SAMUEL), M. D.,
Obat*tric Pafaii^iKn oiul l.«.><urri in liuy'i Haapltal, LoMtos.

A PRACTICAL TUEATISJi ON THE DISEASES PECULIAH TO WOMKIf J

IKuHlraiftl Lry Car^n iknvcd Trom HotpiUI vi«lPrjVBl« P/w^iico. Third Ainencrai], tron Ihi: Tbird]

ua4 KTiM-d LuniJua ediiion- la oau octavo vqIuiimi, exuft cloth, ol riJS pugca. U 00.

Tk«nii>*t »m(ul pra?tt«al work on inaaubjaoi Ui I Tba nMat alila, ami epTtBinJT tbe Biait itBBdard

tkt Enalub i*!ifu*£e.— Bfum Mtd, oaJ Mrc- anO prBelioal, work ob lrimloiliacia>» ttat wcbava

ARNOTT (NKILL), M, D,
KLEMRNTS OP PHYSICS; or NatunU Philosophy, Oenml «oa Mftdi«U.

Wrlltea lur univrr>Bl nan, iii plain ur iiuii-Ior'liiiR-alJBni^ifBge. A new «di1ik>ii, by I(4ao HaT)«
M. L>- CTomplew in ooe uc-tavo voIuum, iMllMr, uf 4M |i«(f«a, with afagM tw« koadred llluslrs-
liao*. %i 50.

aino (QOLDtNO), A. M., M. 0., tte.
URINARY DEPOSITS: TIIKIK DIAiiiNOSIS, PATHOLOOY, AND

THEKAPEUTICaL. IN'OK'ATIU.Nd. tiiiir,! l.y Kv^znu Llotw BJHiiirr, At D. A iww
AnMflcMi, iVviM ilin niXii and cnluii^ej Uuniluii bJiuulu Wiihei(;hiy iliURirsiKuiit vn WuUil. Ill (MV
MildMfmv LK;avu /uliune, ol n>i>Lil JUOpapa, oxUa ciutii. tU IM. {Jiut lt4H»d,l

TbedMihof Dr. Bird has ri]nd«rttd il neecMiiry lixtairiiM lh« rrvKicin of ltt« prAMnnl wAIiob M
■Xber hand*, and lu tiia perrnrmBnoe i>f llM duty thui devulviag on him, l)f. Birkell thaa acdulutisll
mikaVDrcd to cart y out tlMaailior'a plan by lalradui'iny Buok Dew matier und iu»i)t(iratiun» o|
th« lotl U Ike pMrnhM of tci«niw baa colkii lor. MolwilbtlikdMKilM inmost cato to fciMtp lUf |
woilt mibiD a fnumiable conpa**, llM«e addiiiona tiave raaulied in n contidorabiB «ftlaffeiNiMU«
It Ui iberBfoKf hu)ictl ihai n will In I'Dunii fuUy iip lo lUe pr«MMil oundiiion of t&e aubject, wit Ihi
itie rapUlatioD of ibe t-ulutup as a di-ar, cumplei*, bjwI cocupeuUiou* nuuaal, will be fuUy maiUMU

BENNETT (J. HUQHES), M. 0., F. R. 9. E.,

Vtvfttuot fit ClkBiaal MedieitLB la tka Unmralif af EdiabBrtb, ita.

THE PATHOLOGY AND TKE.^TMENT OF PITLMONARY TURKROtT-

LOSIS, luid uB Ibe Local Mvdicaiion ol I'liarj-ngi^Bl aod Larynacal UiwanM frvqucnlly miMakM
lor or ■BWKtniod wilb, Pkihiftia. Una vol. &vo.,wKtra dotti, with Wi>«>il-«ut*. pp. 130. f L %,

BARLOW IGEOHQE H.), M.D.
Phy>li»iin u> tiuy'* Uui^iul, Luiiiliia, Aa.

MANUAL OF THE PllACTICB OK MEOlUINJil. With Additioofi by D.

p. Cunuie, M. U, aiiihur ot " A Practical Tr«ail>« •><> OinM^catifCbild'cfl," Je«. In one baad*

sume ocinvo vuluinr, iMitwr, of over 000 paftife. %i 13.

Wo rcctiaiiBeiiil 1)'. ttufliiw'iUiiuiial la iBa wb/«>> | fouoil it #I«ar, viiaTiac, ptartieal, aad tvt^iS*t-
•at taaaiMi aa « oioit valuable vaJe-meaaai. Wc %»m Mid, nmd Smrg, Jtmmal,
bare bad rr«^«At ueeaalun lo evaault It, aad ba*« |

BLAKCHARD ft LBA'S MEDICAL

BUDD IQEORQE). M. O.. F. H.9.,
ON DISEASES OP THK UVKR. Thin! Amoricui, fimn Uio third %ai

vninrgcd LotiihMi ndiiiou. In one tct^t biuHinne octeTo vnliimr, extra ololh, Willi folU bcMUi'

r«lly oolomO plaica, and noiiieruiu WDod-cti(it. pp. SOU. t3 UO.

flii*f*i'lTr>tBbliihc4rorilMirai>U(M>am'>n|il»'«i !■ no) pernernbly ekuri^, tb« btatnfy «if IImi Ha*
cla»ira) mniiRsI \iitntaic at Ka$t»md.—Briii*Jk ^we» w ixwic iwe«awpMiB| ml w >«yl ■> W l»»*
•lU roriio JlliAcaCiir. J)ni««. I wi»l th» prof WW wf .«■*>*■ ■BtOCe. Itltlk* bMt

Dt. Buiti)'a TrnliH on !>)■■••>■ of xhn Llvvr U '
(M>Wa »B»dKfll Wi>r1i in MnflmllitFriilvre.uiil ilvr- |
hiR iIm iBMrvala wkirh have rlapinl hrlwecn tie
•aceculrt ^diIl<^nf, Ih* aathnr baa tn«nrpnnte<i l«t«

ih? t'lt thr mofti iiTikinx Qr^v^lEiriirhLchlikVF rha*
farlrrii'il tJi* r^f rnl fti-KCat i-f hf;iiilif phy»|r.lt>f »
aMi pNlkirlif )', •■> lliolalthnugli thealsc of il» lioni

Boaau af Ike LireT ia aay Uif aaf*.—
Itrnd— lt*d. Tiwut aaf 0«a«tu.

Thia wvrk , bkw lb* ilamtart IXMik t4 rtttr
Ih* dlMUTf of trhim li ITr^ta, baa br«« oanAV;
rcTiard. anJ many apw il|ailnli(i«a nf lh< Ttrwiif

Ui* iMrird aaitinr aildM la Ui< pfWMtl tdmiai-—

BY TIS lUUX ArTaoi.

Oy THR OnOAfflC DISEASES AND FUNCTIONAL DISORDBBS 0?

THE 9TUMACH. In one niw ocUrtf vnlunc. ei1r« dotk. tl 00.

part-

BUCKNILU rj. C), M. D., a» OANICL H. TUKE, M. D

HMi'*) i^priintnndcnt iif ihn Devnn I.unRl^<l Atylam. Tla)Ua| M*dtral O/ftrar tn the Votk B<

A MANUAL OF I'SYCHOLOGICAL MEDICINE; OTOtaioing iho Hi

Nrwnlog)*. Di!.'rtipIim.:<1alMii^i<, IliudXKia, Pklhnlityy.and TrralAcnt ot tNSANITy. W:

■ I'laie. In oce haiicl»wm« f>ct^\o TR4nin>!, o( ■*>% pogea^ U 00.

The incn:a>« «i tnoiiul diteaae tn luvarloaa fonn*,aRi> tb« diAcull qorvtiom lo whirh U
eonoliiolly Kivmg rire, reud>:r liie aubicci one of doily MibnwJ interc*!, reifvirlng on th*
tJie phyalwao a «>n«B«tly grvai«r familiarity with lhi% ihc mwi pvrpl»sin(| branch of Wa
«io«. Ar ihr aasio limf Ihmm ba» Iwen tbf «om« yt*t» no wo'lt arf*"fiW« in Ihia countrr, pi
mil itir rcinll* of ivceiit uivaiti^tioni tn ih« MagBoaH anil 1*ri.i^i(»» of laianilri and tke
impixi'i^d in«tbij<lii of ifeaimvni wbicb tum done m ainch in ullvviatjoK the rondition ar ri
Ilie livollh (if ibp initan*. T« Ail Ihi* vacauoy ihe piiliilii-bvis prevent llii» ««lumn. wHniml
lhedi>iiiifiii'bi!d frpmaiKHi and eswrienw uf (be aulhiira wiil enliiU> ii at niwe la tha aoabi
«l biilh >!U()i-tii anil ncBClilioiirr. lU (i^f)!* niiiy )>- nai^^fl fraai Ifar ileelaraiion at the atttki
thnl "Iheir uim bav Wpii li> supply ■ inii hunk whirh mny wrre a* a Biiidc in Ihe ar<|uvlti
aurh hiiuwliidfre, •iitni-irnily eleinrnloiy to be adapted 1o ibe wnnla a( Ibe rlutlent, aail autfri
iwdern in iU views ud ezplicii in ii* levdii^ lo autfioe for ibe ttenaaila ct iht prartJliMKr."

BENNETT <MENRV), M. O.
A PRACTICAL TREATISE ON LNFLAMMATTON OF THB UTKR'

ITS CKKVJX ANU A[*l*KMDAGeS, and on ilacaiuieotioa with Uterine l>i>«u«. Tn
ia arfdcd, s Review el (he prv^nl «iaie at Uienne Putliota^. l-'iftb Amxneaa, from l^ i
EpcIiii)! t-diDon. Ia uae octavo volume, oi aboai 300 pagef . mL'a clolb. S3 <M.

whk

BROWN (ISAAC BAKER>,

flDrKroD-AceiiDrlinui ta St. MiitT'* II"*f'ital, Aa.

ON SOME DISEASES OP WOMEN ADMITTING OK SURGICAL TRKi

MKNT. With tian(l«)n>c illu&tratkmi. Onevol. 8ti>., eilfa rluih, pp 7TA. SI m.

Mi. Rtowo baa earned ti>rhiiu*#ir a bi)tli repnu- aail awni the earafsi atualtM t>r ever* •■(
tinaiaihe nFicfilivv itntinent oi auniltT illimari a<ni<elinar.^J>i*H«M«a /earaaJ.
aarSioiuitFBMvwtitcbrcaiiteaarepeeullarlyaiLOjcet, .» c >. i_ - . ..

addilion It. ofratttrkal liitmt.i.c The -i-eralive t..Ur ftirjrfat .lianti-.n o* all ..r«««i

«M!«aii.«aaBrfronlfir»t'-c.«r.,rhMr Br..WD J- '"-" O'mfta'aia-
.Ma.ca.e.klbit BiatJl MWUeal .acaeity aad a.il. "''•*"• V-^""«

J— rani.

BOWMAN (JOHN C.), M.D.

PRACTICAL HANDBOOK OP MEDICAL CHEMISTRY. Seoond Ai

riL-Hii, iVum Ibe thin) and revised Kng-limh Kililuta, In oac noal Vi4iuiw,(oyal tSaw.|«Stfvi
witkiiuBicfouaiJIuatrationa. pp. ^iS. SI 'H. ~~

■T TBK SAXt AUmOlt.

INTROrHJCTION TO PRACTICAL CHEMT8TBY, INOLITDINO

Ly^I^. Sccaid Anenvaii, fruni iha feooni and nrisi^ London odilioti. Wilkai
irwtMNia. Uoaoneai vol.. royal ianff.,«uncl<Hli. pp. 30O. SI 31.

ANA.

VKAl.R ON THK LAW? OP HHALTB IN HR-

LATMiN TW mind A,NP BdDV. A 9*ttM .rf
!>«<('<• (f'xn an uld I'tatliiigner lo a Patiuit. Id i
oae vulaMe, nj%t Itmo., axin «toU. pp. DM.
SBofbU. I

W'TVAN'!! PHvaroLoor op animal anp

Vr.br.TABtX I.IKEj aPiit.ulnrTrr»ii.rvnlhc
Fsiir'i'iii* >in<l Pn>nomFna of Uq^aoie Lils. la
Mc hi>ni]*onve roynf |«n>0- vntame, nitra cloth,
■rt' «mbo*etlOUlllaaltatlonf. PP HM- W)««BU,

BUCKLKH 0>* rns KTIOLO

A.ND THt:ATMi:.\T 111' I

Tl» AND BHK.IIMATIC . -.. . .Sti

An« tiro, rolnnir, nlia duili. pp. IM fl M.^
ULOOD AND irplNK thUNIUI.!) O.fV

JUIIN WILLIAM UKUTITH, 0 OW|

RKF.SP., A\D ALPRF.ti VAHKUICK.

tkMK volame. rani Vimo., fiUa Oulk,

plat*!. p|i IW. |1 U

BRODIE-9 CLIMCAL LSOTVKES ON SI
GP.RV. lT.)i.9*o. doU. SWpp. Sin.

AMD SCIENTIFIC PUBLICATIONS.

BUM3TEAD IFRESMAN J.I M. D..

tiiwiBtar on V«>MaKl DiatBMak! ilia Cottt^ • •<( ritr*kian«*Bd9urit«c«a, New TotK, Ac.

THE PATUOLOOY AND TREATMENT UF VKNKREAI, DISEASES,

tiiclu^inc ll>r rr'!4ilu of rrccni mve^aifiriou* upun Ihr snlyjccl. Wiih illiMlrsiiuos on wiaxl. la
MM Tory h(iQil>o(nu ocuvo voluioc, of neatly 700 jM^r*. cura clolh ; %.'i 73. (A'^k' Kmdf.)

T>>>iiin apall in ■ fow wntdi, tiil* Ixnk lie

-Rf fki lti» mnal Talaahln eAnliiliatinn to tiki* par-
Ue«Ur iManflt of p(ii«tii-« Itiat t^a kHit lb* lighl
Widxti ■■>■ !•« X'nip "f >-•■■(•. III! nlr«r itnil «f ?«!•
nic i1cKri(T|i<ir» o4 tho ratni-ai li<ma xr vrnetc*!
■(■•rvinF, atiil pippi-litlf (tin mFIhiMla iif lrn[mrill ho
pr»|>u*rk, «»■ Wiifltiy iif llir. lii^SrHl en r> ■■■■ i ii m . In
lbi**e (M|>r«-(| It It ^■^tt"( adatiM for ItIF iKaiataiice
of tiM erriy-dav p>acl)ik<i»rt than aar nthrr wiik

I iFhirh
n" piariiiii-c piifMi-iun ■>( mnliral aluilMiL earn reif
wrli affxr-l lu 4u wiUiuUI -— iMirtcni JK*^ Timit,

Nov, 9, IBSl,

Tlie «ii"li» work t"^»*i'' ■ eomplele tt'nlary at
Venriial 'liarnwa. ctirnpiKm; inii-h lalriMling and
VHlniililr malrtiil >liai iiaa h'Yn tp'en4 Ihl^ajCli VKd-
trat ]i>amiil( williin trir laat twrmlf yeaia— the p«.

f'ff^t^td, LB miDB LcnoBB iif dirpGiivn, iviJKl by earf-
ul ill ii: It in I Da 1 1 '10 Iff Tinlnir Tirni* ariJ r<>ini>liea
t(oaa, we villr <1<*vrn ihr t>iKptf aa uiuurpaaaMl- It
ia a wnrk wlkich Dh'iulil bt in i«* ti^naraaiiii'if (^r^rr
praFtlllnaar.— CAiEfign MiLf. ^aanaol. hnv. I'M!.

ttic atilhi.r't riifiitivr. pa<*-'<nal Fi;vriekn, an<t
uiTqi^ Li} tjia jiri-rcaiuiu jq ur admiial^Jc 1i«fA lla
comiilrtcDTM la araitrml Bjr guod pUKa. WliirS are
rajwciBlIf r>ilt In iba oaaMimjrof tbagpniul ■■<){> n>.
We have cxnmiflnl ■: wilh ffeal ■a(iB(aL-li"a, .inil

btafin; thr wrlidl' aohifi of ayplnli-livj-, traulvlrJR ! ■■•4i4iatu:ai« llif imtilii^j fi-lrtu-ti in AW^iira nn
manv a Il'>ul>ti «-'>rret.-uii4 aid e'>iiA(<nia< imtBr na | l lis aalii>uulii> vi a w>rk ilial ini]r fairly lie -vllcil
CnurtaiDP'l cpiniiin. ami in nur eaiiwaiion llie brii, nrifiiiul —ffrlc'^i'' M'd. ./uarnqi, Dec IBOI .
iMUiil«U«i,rull<tl rltoa.^r.iiri «» tliiiautM'-.-i in L,ar ■ ^ec taini, howevM. wa are impdUd lo ..r, lh*l
iMfMBP. Aa Ut ■■ ihr .a.W.i'a Ul..«. iftrm-lH'. i ^ ,,„., ^, ,;;„ ,„ „,„,, ,^„,j ^ ,,-p|„i„.',„ ,h,
il!15?*l?^''"'/.f "j; I ''\*"i' ""^ hthaa. ii„„„ LntuM., wbiclt om M rail, »iear auj

laM,wtai»t 111* il-«hir.i l,>i,=.l,nlr,ili^l.«i .],■ „ f^f„„, Wff oadsot, it.!nMiir«r, rWraia from ..-
gMMd UMIiaai en iliraa il..«..Ra in .-or laii(ua|(. | pr„„„j ^i ullafaatloD Witt, itac fall BMt parajiru-

wo iMi II a ouir MM)- tnai ne naa ■ !;„„„ i.ntuM., wbiclt om M rail,
i.»l hia .iih.,«-i>u. h^ h.a i.fF-nin.1 i„p„„.| v.J^o/ifca impfruut .tibir.^1
llic il,,hir.i ii>iic.l><,tc.ili^i.c.i .]i „ „„„, w«oao«ot, it.>w«ir«r, mTraii
,, , "» 'I"" 'I'"—™ 'a '•0' '•"(uagc I prMaiOB oni ullafaatloD Witt, itac fall Bn» j,...^,. ,.-

Hr Maa *arr.«l lU Mtr.lurc Ui.wn I,. Ilic |.»a<u[ , oua nunnei in Winch Ihc aut.jMI liiia b«D pfcaetilol,
oi..ni«nl, ai..l (i-a .ctiiPv.^rt 1,1. laak in a manntf ,od Ilia MfTrul Bfuilua ii. nunuu> .Inuila, ao ua«.
Which rar.n..l hiil rrilLUnd 1.. bla Wcd.l— B .UmA (ul-n-tioaay .o.lia|i«i».l)lo— Ib. pcaetical .te«lia«.

We b(1irv« thia Iruliap will ei^raa tn ba rec^tdad
•■bicli ■uiniirlij'lb thli uraaatifidnediLiilpraotice,

■B>J wr puiiiiBlIjr eiiiuiii(-iiil It Ui tlinfatixililr antkL-r

vftrufhisilifenin ilieiinifMaioo. Fucuur own pait,

wa r-4iricliJ]| etiift^M iliaC wh liaifr m-vivHt unn}-
■eiv ia(*a from Ita ffcmiat, aa Well •■ mnltllrii inaii)
via w* whirh wr liava h'UK. aO'li ■'• wp nnw tiiink,
•ffubrnaaly Bnlcrpiiacd uii Ihe autijoct »l a)r|ilk(lia.

y loiliapcnaatile^lBi pract
In c>»ni^^ aa Kill ^ if wr niaf bn '^uiilirnnl tna uap of n
ptirau U'lvr Ivcrjiim (Icirolypeil, hul wliinli wa harti
ciopl-tr ts all Mriuuan«aa and t-.atrmy, ife du »ot
htatlaie M aaprraa Ilia i>|i.ni<in lliai D(. RuiBaMad'a
Tlaallacoii Vancrail Piantacd la a ■■ wwr> wllkottl
whivh aoaanlMal libraiy will iiotmriar ba rmn-
dettd e<Mlitlt\9."— Bmttti Jllnt.»aU Surg. /aanMj,
SrpC. 3, LMt.

BARCLAY (A. W.), M. O.,
AaiKUni fbyiiciin oSt.Uoiitira'i Huipiutl.ft*.

A MANTTAL OF MEDICAL DIAGNOSIS; beinji an Analysis of Uie SigtiP

anil Hj'inplfiina nf IliiroM*. tStDund Anifiicnn (rum ihe acooaid aail ravionrf IaNkIlmi ttlilMXI. Id
one nral oi-lava volume, rilra rlolfa, uI -l^i pagca. (V 'i!t. {ffote r»i/iy.)

T^c demauii Tor a oR^ond rdilioa oniua woik- *bitwa itiat ihr vai^ncy whkb it Bltampla lo *up-
iiljr ha" lifted rrtxignitiHl by IIm pr\)fo9*tua, and thai liiecfTiinn i>r Ihe uuitior in meel ilie want bova
t«Mi niofrwUill. Tint ttviitot Wtiii'ti (I 1)84 eiijoyed will fendc-r il btiief adapted Ihuii l"-l..re lo
■lli>r<l ufi-iADce 10 lb* loaniw in 1^4- |>ro*c<;<iti'7n ol bin atudir'. aiidui tlii. jimcii'iLrfiur wn«rvi)airL*>
• oonvcniMit »nd an-ewibla maBual ti^r kprcdy rcr«rviiDe id ilie cxifrencici' ol tiivdiiljr dniirp, Knr
tkwlBll«r purpiMK- lit couiplelv aiid nleuuve Index render* iie>pt>i:iiLllv v»lii»blo, olla/uirikcilitioi
for imcnvilMlely luruing lu aiiy class vt' *yinptum*, ur Miy raru.-(y o( diavwie.

Wa hupa Ilia v*lum» will (lal'B aa eatMalve clr>
«atallott, naiainoac atuilaula of otaiticlfta i>aly. bat

firaocitiuncra alaii. Tiiinr will aarar lef rci u faitli-
al itudy or ilapagoa,— riacti*i»at{La*uf,

An Liaparwat arquititiw lo maJical lllarnan.
Tt IB* worn of hifii iiMiftl, both iruiD tke v»«l iim-
|i»c:aaea ft laa BUli)»i*t ajMia wtnoh li liojla, aa4
■Ito iiuca tha rial ability diaiiUycil in '•■ Alnb-ra-
li'in. lu wiinvlLtiiiai, In aa l>pBp«aK fm liiiaTnlnine
Itixl allmti^ui tit eTcty aiudnat uf uai art arhx'a it

Tha taak nf cdinpittitif turh % w<»k la iiallhcr an
Mar nor a U^hL <>nci bui Ur. BiiTclty hni pcrftxmad
il ia a eniiniLei wlii'^h mrera i^ur m^iil BHqualilicd

apprubaiiiiL. lie II □« <Mtv ii>«->riiii he kaow* hii
wiHk ihiiT<iiiirt<ly,>ail ia aticnipilna (ki perfotin U,
kaaenteicflnlHlbupowera— 0'il*>hM<d..;a«naai.

Wn vonlaia topradicl Ihat ttin wnrk will ba d«-
•ervMlf pnfiaUr, anil aoan beounie, like WnlKm'i
Praaticc. aa lailiapeiuabte a«csBail|r Ut Ihn praoli.
aomai^—JV. A. U'i- J»infl.

AalQCallniahle wciik of rer«T«a«e fi>r tbo ronai
praeliligvvraBilatudcat.— iVaitPif It M(tf, Jaanaal.

B'l tifhly ika^avra - (kal pta«> in etttj wriiif^l
library which It cui an weal •dvru'-i'niaiBJar

BARTLETT (ELISKAI, M. O.

THE HTSTOUY, DTAOXOSIS, AXD TRKATMR.VT OP THB FEVERS

OF THE UNITED STATKS. A iwwud mviHfdediiivo. By ALOMoCt*kii M IJ , P/of.

91 PuboJvtty and I'nftii-al Mi^dicinp in ttwN. Y. Coll«g« ur Phv*K'iaii*mii<t Surgi!Qai>. Jtc. Id

oae oclavo volunv, t>r bis buudrnd pt^^va, rxiraolixb. Prkv $i 00.

It IB a wmk of Ei«lpt«<:liRat valaeaM latereai,
WMniNiac aaueb (hat la new rdativa lu Iba (•vnal
MaMMaw which il tmla, and, wllb Uie adilillima

•f tlMMIt4>r,la fully op to t lie umnB Ttedlalinrl-
ivrfraiaraaartbadlffaioalfornisiif fevoaiii ptaialy
ud roTClMrpotUvycil-kild lh« llDria(danMr«aliMi
catpfnllraBd aeeaiaUJi- drawn, and to th« Amen*
«ak pracliUioei iaa nivr« vslaabl«and aafa fald*
than anj woih am fcTvr «ilaBt-.— Otta Mad. amd
tnttg. Ja-anwl.
Tbia escellent nooofrapb am fcbiile dlaa*a«, bia

■imd dewervnllr bi«h aiiw« lla firal pablioalinn. It
will be aecB laai illiaa aow ivtifhod llafuurth edl*
Eion OBilvt lb( aupri-viiiiin ■-( i't"! A. Clink, s %ta-
(leaaaa wbu, fr^in Mtt iiilarc "f hiaiLoitli-a uod gmr*
■HUB, la well tralcuUled CI ■I'preclate ami iliai'Baa
tk» IMAV imrionle anil ■lilDculC giaauost lb iwiiiu-
logy. Hia ■nn.iitallniia aiiiJ luacli lu IU> lulrirai i>|

tks work, and huv- ^roujiii a well up lu \kf •'■nji-

lion ot A* ai'iflnr',- aa 11 eiiau al Hi" iiift-ni -ja*
iB Manila Uia elaaa i)( diaanaea.— *a«i*»m Xa^
■Mt Smif. Jtmrmat.

BLANCHARD ft LE&'S MEDICAL

BRANDE iWM. TJ O. C. L., "" ALFRED 8. TAYLOR. M. O., F. R.

oriitrMijMti'iMUttiAe. ProTenoroT CfecBtiirr**' MtdkiJ 4Hni*i«laE«i

CHEMISTKV. Id duq baDdBOineSvo. TolumooFoTHrTOO paiffCft. {JaURt

" Hirinr bMS cnpsfnxl iii mcliinc diemimry m lh>* >Mn>p<>li-, ibe «ne /)«r m period i
ead ibe chmt for ■ prntMluf ihtrty yrara, It ha* appeared I v ii* ib»t, lu *tiH« i>f ibe nuiiitwr <
•trendy nti-tiiiK< <bere wa* ruuoi Tor •■■ ■dnliifDii*! voluritp, whii^h »lii iiU '■« cfpi-r-iall v ■ilap'^ I
ibe "*e iJ" ■liiji'i)'* III prfpttniig •iH-ti ■ voliiiiiit lor iW ft**', tvn liavw railravi»ril lubrM |
iiiiail, thai tlir ktiiilrni III ibr |>rfM'iii il»y liD« niiirh to learn, uid but ■ obptt (iiavnl biadiapin*] f
llip u-iiuiiilion orilii* lenrniniJ.'' — Aitritoit'* I'liKrACR.

Id nprinliiig llliFi vu'iini(r. It* pHv-ugr ihrniiph tlir |iniiii> baa l<rn m.iv; :rLl>-ti<Ii'il !>i* ii i'-|irii[
cbcinlnl, •n\\(t haj> *C()uluu>ly eiii<«u\ urrd li> tvcum \tte biti' -tfl

Mlurv. No noir* or adilliK-ii* b«Vf Ikcd i(ilmitiK-r«l, hul lh<- ] ny I

autlior* wilb anme ixwn)c4iiiii> a&il ft-i~i»iiiiia (if iLr iirft Iwrni^-.inir > itapt.13, nun-u •!■■ c iKCicdil
innritiMl.

Fiir falDoM i4 naitcr. for lufilllir of ••r«n|a- 1 Thia b<f4t||lTC(ta Uic eteatwtwrfi
]iMiit. fur Fimnnu olityle. wiiiiuDta fival.->Lan* I ry nrnlwrf ii-isulilig. all ikn facta ami tltctna

<«i, Um. 30, loot. I tVtm*\.ti.—hti4. Twwi, Nov. u», \im.

BARWELL (RICHARD,! F. R. C. S.,
AMi*mtii $urf*»B CliUDig Crusi nnapitsi, *c.

A THKATISE ON DISEASES 01' THE J'JINTS. IUostral(N3 with

liiC<oci wuod la one rciy li&nJBucn« octdTii voluiair, nl uliuui 300 pujfc*, rxu% olulfc;

Al 'l>r ■in((«( wa laav ■lata ilial Iha traili la la b* nf much au l» ih" rraniclnf •orc^nn
W.rrlh) <>f much itraltr.acid l:m)l* rviilrsi^r >il mack ■)■>' be in trial I't ■ lirali-
lli'-ufJiKul Hiid earrfnl mgiiiry, and li-re aad I Inn- bu■• utifthl irf iiiiialii]- Wp Iiav* aXitmiy cairiid liifotniaiiiw itn adi 'ula'

Iflit in>iipf (anhflr (hf-n wr ifLt*iii">i !■■ fl", bat nm 1 itnoi (o» thwt ««ie.— ila^i* 3it-i- i'i*t*t J*6.
I ' (!ir raiinl Ih* wT>rti ilranvri. Wrna anXj ad4, i ISSI,
Uai ihrr.e™Ml.,MthB.«irr.iil«luir"-aliil«-»re.' Thit voIbmb will hewfloMTF' - - -v i»f

^•" ■ ■*•'!"« "-i-^n'tr w.-tk-.l »e»v hare at l.ia ,holo.l,t am) ll.r ....».■.*, a>

Mh^rt, «B,I In, ,nv.T,i.fni|.n„ laio i!» Pkruclotr mniB boneal »e.e.r' I, i„«'*t,
MHl l>«li'<ti<|ty "< Jr.lntf hH*el>Mn enrrieiKiB in a ,h«nBton-Bnd !'->■ ■ <
IMnnFf wliirS tnliiira Ixn la W litlrnnl tu wiili ^f a^tmirtt, Vir
aiimijf>n iind r»|iE('t. XVi muii n>>i uoiil lu mea- tmiaalilp Baii iiui'i
IfD llin Yci)-a'lini'»Mr plntii wirli which the »<►• |j, n,, anini.iil -f t.i- i -r *•■■
h.wci»njttri.«i W.«HO«mi...«withiu*h«tl*- ,,„,„i,,^,„,.f„„i„r.„|
IT.t and Tailliful ilf!inMli"ai of <1i((iuo.~X.«ufMi ni.tirf (,J . v-.timi- >r.

We ciniint (ale l<iavc, hnw««*r, of Mf. BaTWrtl, fail "f lii >••
Wtlhuat vi>nc'B(uli>l>ri| h'm en the inmcillaa , (ar Bnrmm
attmnDl of laioTmaliori whi^^li he Uaa cuinptciiei! /.aaifaa Laai'd, Aitiriiv, irHii ,

Inia bli IwqIi. Thv irnrt ap^ieart k> u* oaivnlaiN I

Ihii'll II r-iT^hiM

'oK-makiiif . 11 la Bi'*ii|
I11W l.h"rii"ii« lanHiii

ii;;tB<alalf

CARPENTER (WILLIAM BJ, M. D,, F. R. S., &c.,

Eaaiuliii^r in Phytioloff aiid OiiupariiLvc Aaaiumr <a tb« Uoiveiiiti' i>r L<iad«a.

PRlNtflHLKS OF HUMAN I'HYSIOLOCJV; with their chief appUotUoM
P^iyrbulo^v, Pilholfwr. Tberappuii», H>Tienc-, and fittttint- .MrdK-tii«. A Mrw Awon«i
I lie l*Ft and rsviMtd Lundonedllion. WiiIi ncnrlyihreri tiundred LlJuHrulinno. Kdilrd. W
tionp, by FxANCisUirsiiKy i^xiTu, H. D., Prulcuorol ih« lotlitumoi MtfdKtDe ia (be _
riutwModwalCttUflgv, Jcc. In<«i« v«ry krg««iidt>c«Hlilulc-i:UivovolunKi,idilK)Wun«L.
lBP|t« {«(«•. Iiandeomely priated and Ktmngly bouud in leailwr, witk raMed buds. M Ui.

F.>r ujiwaida of Ibirlecc y(*ri Or. Csriipnlcr'! Tocol'irii^'' )' '•-■'• --"<irk wimldbe lapa

vi'tii »«■ bci;!! f»ii(iilrin! by iiiv (,riif--i*ii>n g'ii«' W« ■V'bI'I i ■\ei, llial,ia ihli

lallj-.lKiih in thlar-iuntry and Kng[a(id,aa th'' niiiat Uic aullivr n -i ■ iarga Mirtiin

nlnnlile I'liini'tijdiiini "n ihr ■iiiijriri iif phytiuli f r furmer, a>d U.^ i-.ir. .. ,1 .. siMml niii''Ii Bial
lanur 1iin)(uii|r Tliia^iiiiiidiLiu It iiwrn li llir hr|k Mraal, eBpanalJ) in tho (iiita uf iJluinatK.
•Italnniirnti aad otjn-'-nti<>'I iui^iiliy of It* BFCom- , ma? oosfrdanlly tec-BiinMid Lt a* IMmnmii

fitlilinlaulhoi TlirinrBriilcillliiin < wliii'h.likc (kp I woih on flBiaaa I'byalulnfy IB viai
■«t Amuricaa (IDC. Will prepumf by the KBIbvt ttlin- | StntKtt* tttd.mu4 Smig. j#«ra^.

b.t.llya.y.,nc..i«lu<liii.<hi.t.t.p(o..ti«,llial«niiW "*«_t"»l[«— ^M. "»« ■'♦wr^rtj

l(i«ii>'..rkinD(H»i-'tit»i.Wt WTriy *taJ'ot of medi- >'" nip«lc'rt"p1rtr w..f» now cktaat la «« U»>
list 111 '►li* i^'miiltj-, i' null airLjilj- iipav the p tacli- , (""<*■ — ■'"■ C- «"*- Ute^'i"-

Ii>>cicr fur III pcruMil bv the iiiliririi BiiJ valaettfitB
•<ttteiiU.'£oiiM M(J. ■Hrf Sar(. /^Bmnf.

XhitUBttaiidaiJirotk— tOctKil-h-okuicilbyall
nr'ljoal ■luilcnia wliii trail ih? Kn||'i<li lar^uagp.
Jt liRi |>uaisl tbr-'iijch •cvviul ntitiiiiit iu ■■nirr ti>
kcrp pai'i- urilli Ih" H|iii\li g-mtjuj ••■irucr ("fPliy-
■ l<i'"<y. NnthlB^ ertil l-r man! ic iM |t'Dt»'-, fin It*
Mmili are aBivrrially Known j we kavo a-lhlDf U>
•ay "f II* defrda, f.n Ibay nnly apfrnf trherr llie
BctMiee <rf wbteb it ireata m UK<nnfltU^—W4iUni
i.m»ttt.

The brat U>t-bo»l is thr ia&ja^c oa Ifcla <a>
UIL»v« (ubiMI.— i.aaian Mid. Tiatu.

A pniniilFtf cycIdoadlA nf tbU biaaob of i
— iV. r. Jf-fl rt*lii.

i>/Kb' -luriyaidf- -

tltPBiiii '[ ihlaaearri.

UttirBiii J ,. „}. Ula fonn*-- .«,.,.,..

naay year* !>«■ ainDBt Iks laly taaMma oa L
■t<.'t>j«y in all oaf BlWIlaal aekoola, aad ila al(«a,
lliiu atiiiH^ iIm [irnristlfls haa brrm ■aiBiiialaliCI I
.. ._ ..._ f mjatcal acjiaaa

«a iw pah at \
•alify The Bert
, — aBaenleOiiiDLBapp^mliKa will aSiifd IbaO.iti*
TbPirrMtrat, IhPdb'Bi taMabt^.oM IMb«Btbo*t pleaaair If crcry ■iiHtmliif n>r*fJt«y, wkiU
as ttiE aubJMt wlikcti w« k«i<w it4 iB ui« t.a^Ma faTuvkV w^i Iw wl lAbBlte MTvl«a W adnaai-

Tlir innd en
•ay iBiif uaiie
tS*J .'Ckimtf

mplci<.pi[.iaiili«Drpbyniil<i(rtpbi9b apyvmrk la anr ilRpn'Im'al ofi
can at i.r<«CBl fi»c — £'j(.«arf **». '','• qaiie BaBwew--f) hi «
r. itji'iii*. 1 WMB aa Ila antit* would i«M

AKD SCIENTJPIC PUBLtCATIOMS.

CARPENTER (WILLIAM B.), M. O., F. R. S.,

BxaMlaat tn PkfUAaty and CumpairBtive Asbivht to U« Ubiircfaily of LtqidM.

THE MICROSCOPE AND ITS REVELATIONS. With m Appendix coa-^

iHiTiin^ itir Apiilir-miixi' (if tlie Mu'ro>c(ipr lo Qinicai Mmlii-inti. Jc<^. lly P. G. ^mitm. M> D-
IIIUKlraird by Inur hiiiidred itnd )IiiTty-fou( Ivamllii! rnKruviiinF- i>n wikmI. In utte i«rg« ud vary
fcBndHimr' odava viilurae, at TM pofvt, cxiru cloth, S-l 00 ; loulttcr, 44 AO.

Ur. Cupcnier'H poeiliun a^ ■ aiicri)»ci>p»t uidpliy«loi>«iFii.aDilhi«>re«le](pertMtc« uattMCli
Mnineoilv qua'il'y bitn Iv prudiic* wini Am l«;af Im<*ii wuitad— « good l«u-tMktlt on ibc praclic
■M oC tin micKwMpe- In ib« prvK-nt wlumv hi> cbKoi kii* twea, m fHted In hi* Prostee, "
ooniiiiw, wiihiD * iDodeniie cmn [MBS, that iniuniiaiion wiih r«g«rd toilw UMortais Mool*.' whi<
» nunrtOMcalul lu ib« wuttntg ffliaru>f-i>|i(>ii, wiili ■uiib «ii nnL-ogm of ibe u>ij«<-i# (m^i itirfti (o
kUutMl]r,Mmij|kl<|«Blify bim la oomprpiixnd wliai tie utnvrve*. Mid inighi ilii|> prrpare bim
beiivAl (oWacid, whiUirifiundinK anil rrireitiinK lti>-owiimind " Tliai Ik ba» aucvctdci in i
pli^buig ihia, no una acijiiBLiiird witli bu pttvtuin. iuboim ata doutil-

Tbagrcal iin[H>riaii<« ot ike niic' ox-ope aa a iiiFanii ol' dinfiioni*, and the aunili«>r vf mii.....„-
daM^feo arc afHO )iliy>ii-tiin>, havp Hidtm-J Ifan Ainrncan piiliJi^Wr*. wilh Ibe author'* appti^val, iq
^wliKApprii<lii,ran'(~iii;y (irrfan-d by I'nifraSof 8(nttli. nn ihf ii|>|:irirutiiiii> of ih<- in*lriiirii.-nl lo
cIIbIoI" mrdii'ii)!?. liigeiNrr Willi ail Bi-n)4tnl of Aiiirru-«n Mhti ■*■-■< pr*, i)ii;ir mudidnktiou* aad
afee*aaHf«. Thiii portion oi Ihi^ w»rlc t* illnii'rnlH with nrur<y %me hnndrcd wooil-cuu, and, ll It
hope^, will adapt llw volume mun! paMinilai ly to Ihe um nf ibe AnMitcaa alndcal.

ThoM who mte arqnBlniHi wlih Di. Cui(i*ni«*i

(ifcviuu* wtiliii|i iin Aniiiinl iii.i] Vr^rtntilr i'liyiiii-
(«y, will full I uadristDEKl h<-w vium ■miri'Tkiiiiw-
ts3(c he (• able tii li»ii|: tu tioir KiMm m riiin|irrh<'ii-
^v« a •vbji'ri hb Ihr rtv^lnlii^m u' <li* ritii'ruapupff j
and evrii Umw ivhi> liavi nu iiiivIhu* ■rijuimtaiirc
wilB Ibe (■[•niirurli--n oi awa ui itiia uiiuumiii,

iiinllnal wiirk.lhii aildiliijai by frvf. Smith ■!*« It
■ ■■••illive clmin Ujniu Ihe piote'iai'ia, Tor whioh wr
<ii><il>( Dili ha will re«ciix Uicir tini^ete ttiank*, lii'
tieeA, we kiiifHr itui wlirrc Uir <lu<l<tbl u( iiiodiPiTjA

will find int^h (teonipt«i««ii4 ■■iliiacE.>i7Ci-llMtii«

<i( iiilrrinirKiiir faei* liranni iii>"a ftirntittmY and
ptaciivul mrdieiiiF ■■ II coDlaintd In Pruf. Smiin'a

■111 Anil nil II nila II I' rill lar>iiiiial>iMi runvrjnl in rinii | ap|iriiilia ; ami thi* nt llo^ll. It jh-fiki [i> na, !■ riiih-
iMi (luipio lajiKUa(t. — Mia. Ttmt* *tta Oaa««M.I w<>rtb the Cutlor Ui« vulaB>«.— L«Hitci[f< ATiiical
Alihiiu(h utlcimlly a»l lnimi4cd aa a atrletly [ A"**"-

sT TBI laKi AtrrnoR.

ELEMENTS (OR MAKTJAL) OF PHYSIOLOGT, INCLUDING PHYSIO-
LOGICAL ANATOMY fVofMid Am^rifan, from a n*w and wviaed LcHiitttn ediiloa. U'llb
one hundred add ninviy illiu'tralionii. In ona wry liatidoona octavo voluiu*. kaibaf. oo. M&.
$3 00.

Ik pnblishinic the ltr*l (^diiion ar ihia irorit, il« liile wv. altemi from thai ol the London Toltime,
by th^ sub'liliilion of tLo Word ■' f^lcmimu" for Ihal q( <■ Manilal," and wilh Ihe author's ?tBnc-iion
the tilte ol ■■ Elemenu" I* still reiaiited u twijif more ei|wcnMV« of the Mx>pi? ul IIm ireaiue,

Tn aa) thai 11 la tbe boat iiiajiuitl »r l>hyal(ilii||]p Thiw wlio harp uvpaniio liir aa «lfinsntarT Irta

Bawlier»retlif pul.l^i'. wiiuldooitloaatltcleBt ja»li<e
to lltpaalti'if ^Buffalo MrJ't-l Jommat.

In bia runnrtwiirka it would *c«n; Itaal b« bid
•SbaBilad lb* aolijaPtfif (■)■)' ainlncy. In llu f rcaeni,
fceflve>tae«a*«nee, B«itw<ia,ofUi«Wb«4o.^ff. t.

Llae Ki l'hv>ial<«y, vaiiiiiiit di> Ivllor than liip<.iaacaa
ihKmtflvi-ai>rilt( Ilia D un 1 uf Dt . CarjiaBKr. — jib4unl
SxamnMt,

Tht b«i tnil moat oiimplviq (ipua4 of nioilerii
Phy«l«l"jry, in op« voliimr. eilani in tbe &iglub
langiMfe — iSi. taaii Muluai Jvmmal.

IT TiiK lAMt ir-nioK.
PRINCIPLES OF COMPARATTVE PHYSIOLOGY. New Ameriean, fi4m

tbe Fiiiirth un<t Kirviwil t.^iiijiin edition- In "a« lurav and baiidxime nciavo volunin, wilb over
tiurr hLintlrvdIieaiilifui iUiuiruIu^na. pp. 7.')3. Extra i-iuih, 14 SO; IpaUier, m»e4 baMi*, td 83.

Thia Ci<">k (hould nni only li« rrad bal tTiotnuf bly ;
fftudlail ll]' fvfty mfmhti n( thr prnlpaaki>[L. Ni>n«
arc l<>i> wiap ui old, to be bcnililrJ ILvrrliy. Rul
atpiioiallT tu ibft yoliDKri elaaa wiHitd wa eixdialU'
OMiibcbJ itaabeat itiadof any work ta thaEnfUali
laagaafa tn qaalify tbom fui iba f«i>aponn and ontn-
pteacuaioD iiFthnw! Irnlbi whicli me daiivbciaf dc'
T«l«pvd in r<>y«'7lacr — J(«(t*aJ '.'» """"•'■.

Witlioiil prrlMdlflf to It, II la an rnrvtl-ip'dln ol
tbn auliinEi, aceecata and complvla la all leapecta —
■ liullitul iedc«ttua o4 theadvanAMl autie at wbieli
Ue acirner haa now arnrod. — i)ii*lia ^sMiarlir
/asrasi a/ MttliMt Ktiimn.

A ircily inii|[iii6ocnt worK — in Itaalf a paifoai pby-
auilogical atudy.— AoaiiH^'^ AMf^tl.

ThlawiitK aionda witUoBt ita fettuw. It U imv
'fcwmen in l!an^«co«Id bavcnDderlalteai Itlauaa

LII man, we beJlape,«oald bave biawalil h> aHaae-
r«aifiil an laaiin aa l>i. Carpastoi. It reunited fur
Ita |iru()uj-[i<« a pbyaiulucial at laice i^tfif raad In
ihr lalnira »( iiiii(i(a, napabla uf takii^ a (cwtfal,
eTllifnl, and aBprolailired new aif tlma* labiiri, ann
n( fianiiinintt Ilip mint. (ii^lfn-Bcuc.iUk iiuilcri^la at
hia iliapiMal, an aa I<> IiKbi aii haim.iiLiiiua aholc.
W» rt>»l that tblaabalrafri van fii-c the reaJera v*ry
Mpotfrol Idea nf Iba fatnraa uf ihia wurk. anil uo
(dm i>f Ita onttTi irf tbe admlniMe mm iirr in wliich
inatrrinl hna liron bruogbt, from the mnat vmiuua
•ourcca, t«c<7nducet«iUMniplatasaf,<-i'llir lufid-
iiv of iho t(aa»Diiig it eontainn, or of iti« clnarairaB
«f ian|[itBfeiiiwbiob UiawbolatBOlMbed. NntUie '
ptor«vaiii[i iiaJT, but tha aalMitlla vatid at laraa,
oiuai frri dnriily ioiMiltd la Dr. Oarpanier for Ibln

(real work. It aiuai, hkIvmI, add Ivgoly tTan to
ia bifb Toprntatitm^—MiMtAl Tiwiti.

»j THI MMI ADTHOi. (Pnparing.i

PRLNCIPLES OP GENERAL PHYSIOLOGY, INCLTTDING ORGANIC

CHKMISTKV ANU HISTULOUY With a 0™eral Slfetrh o( ihft Vejelable and AKlmni
Kum:iili>n), In oun lurfe uiid very baudromu octavo voiHro«, Wilb acveral fauudred illual^alioua.

IK TU »*Jlt Atmoi.

PRIZE RSSAT ON THE USE OF ALCOnOLTC LIQUORS IN HEALTH

ANU DtBEASE. New r<diiiua, wiib a Preface Iry i>. F. Coi>:>ii, M. D., aad eiplautioaB of
MieutliSn word*. Ia outs nmi I2am. Tolonw, «ku« «luih. pp. 118. M onili.

BLAHCHAKD dt LCA'8 MKDIOAb

CONDIE (D. FJ, M. O., *o.
A PRACTICAL THEATISE ON THE MSBASE8 OP OHTLDREN. Fiftk

cdiiiim. raTlwd and ftUfmcDtcd. In omj lania val«aM, 8ro., Iraltwri of orcr 730 iwgeii U M.

In pr«*vnllng n iipw knd r*v)>«-r] iilitioi] ol Ibti farnrilfl wmk, iImi piiUinbM* Imv« only- lo ><■
Ihm iW Olllbnr hna Pii Jrnvi.frd iji rrnilrr i1 in rvrtry rr»prrl " n Ct'BipWi- »imI failhTal f^puntlMAI
(be ^!htil<i(tj- »ii'i llicrapfHIrt* iif itii- !■ .1 i-iiteol lo tkr rii(';> r ( ni>l*u<

uid cSBCl ttcoaniiil ol Ibc diiTHMTr ul it mdliiMiii." Too < • ha h** i

Ibe whuir work to a Mt/oriil Ml*] 11)111' .n, rrwnlJMt b ■■.i {■>r1lo«,«idJ

MVrrikt new cbAptcrK. In (ttl* Dinnnvf il ii< bi>|>r<l ihM adf ilcRnMci«» wbcck iua)*l>ari« pncTfeQC
uiarMl linvclwcnKupplii-d. lluil Ibo recmi labuta ■>!' prMilinMcn umI obMrvwr* lutve Lena
touf^bly inoorbiintied, a^d ihai in ever^- jn-iiil ilie work will tw liitMd W ■•miaiD th« liish rrpoti
it hsf- enjoyed a» ■ «>iii|ilerr aii<t iburoushly prartienl book of nHrram ■■ ml^tila UMliaaa.

A few notice* ol' pr«v iou> adiitou* ■» atibjoiBed.

Df . C'lmf]*'! aohularahip, ■i^dimii, Iddailry, nfiil
prarlioalwnackr* maalftalM lu Uli.aa mall bli
aunHr>>iitcwD(rlbau<iii* in •ripoca. — il*. K«ti<tu'i
Safari fa lii Atnttiatn JHtdioil jlMMioflrB,

TakrQ ■(■ wliulc, in (lur Jnrlgnirnt, Dt. CD«die'a

Trtaiiie ii iht on* rrom iiic jhoruMlof whi<h ihc
prcpiliiiinrr In ihiicounir}' will riM wiUi tli(|[rati.
rat ftaimfaeliun.^ — WttUr* J antral tf Me^ttiiu and

Una tif (ha taat warka Dpon (ha Dtaeaaea »l Cbil-
drvB ia Ibv Bogliih laikgoif a. — tTiitttn L^tuti.

Wcfcel BMnrMt ftota Kcrnil experience tbai no
pafidelBD'alibraTir ran be ccininlrTF withonta CDpr
«rikl*vork^iV. r. /etinMi g/jlf«Ji<i'iM.

A veritable pwil^alin- riir^rli-ixriliii, anil un bixini
Il Amuloan mtxlienl litirunre — Oii» tIfJUat »m4
B^fgitcl Jmttnal.

Wefeol ppitumleil Itaulihe Atnrriean rocdml pro-
r*aKinn will armcrritBtt) il iii>[ unljt ai a verjr gwMl,
bvl a* lae VsnT but " Praclienl Trnliar os llif
Divnari (>f Cbiltlrm "_,l«MHr«a Mtdlial Jttmft

III lh« (i«p«rlnitiil vf inriiltile Ibtiapruliet, llu

W«*k of Dr. Cl-llilir ia I'liiiililriril hub ml l|]i!*|].Fal

Whkb bill Irfm imblialird 111 llie Kuclitli laiMUMjcn
~Tkd BUUuuiof.

Wa prosu«B(vd thr Inl nllilon lu b* IWli
■<>rt <>• III* iltawaea of childrea In ibe 1
lanallaga, and, ontivilbataadiaf all ikal ha

wort <■• III* <ltaw>ea (K childrea In ibe lUalv4

aa Va
(•ublUberf, we Mill t««aril it La lk«( imhl^Jiiirfiaai
KTaaaiMif.

•tbel

Tb« ▼■Ineorwofkaby salirc aatborion tbii
oaaea arhieh Ihe pbvaieiMi iifallril up"D l»r<a~
Willl>«ii|>i>(ix-ulPdbT nil, an J il.r w<-rt •;( Uf.l
<llc baa gained ftiflUelltkapnaraeleTnT* M/afat
luiaiait(aia.««da Dieful w<irli for <«A*allaiKift 1
llioa* *B|^|[td Is praeiiar , — N. T. Mul. Ttima.

THIi II Ute rManbe4ll»i<aof Ibu 4raer
lar Irraliae. Dunna Ihr ialervai atare I
lliin, tt Im* lie«n i«b>eelr4 lo ■ thvfowfk
bf tb* author; aad all new ch— rratiaai tm
|iaihiilOi$>; and IherapiAtici 4<f rhlMrea h«^ ~
inrlailHi ia ihe prr*niii iriiluM*- Aa W* aatd I

wa do nut kauw «[* beltei b«ok ra i'
dreo. Bad to a laijtf paiil of IM TWoi
ylald aa nnhoaluil^ ei»em rnaeo^^Btif*
Jttntal.

PeihapaiheoHiatfallatUle'aMi.lptaWDirkMnd
rur«Uiepiof«a*ii«o(ib«CallFdSlalFa; ladert,!
'Ba)' aay is ibe Bogliab IkDf ui; r 1 1 >■ i-Kattr ai
rioriaBi»alof;(«»rc4c««M<>ri ^T^mntwrntBl
/asnMl

CHRISTISON (ROBERT), M. O., V. P. R. 8. E., lie.
A DISPENSATORY J or, CotntDemary on the Ph&rmscoMEiM of Ore*!
aiMl ibi* Unil«d l^Bic; cumpming tbe Nnluial Hisiory, UrH-ripouci, ChatDmlry. Phamik.,
^OltB, Um#, b«i1 ItopQ* of Itic Aflii-!e» ol Ibe .Mulcria Mf^lica Sn-und rdltuiO, rcviaeil aa .
'froTtA, wilb a ^^upplrrnrnt ivniiaiiiiiit; tb« moei impuriaiii New Acinrjica- Wiih cufHous Ail
lionN (md twol^uiidriMl and ibiricrii large woiHli-ufraringK. Bjr tL-K^MwrmLnOKirrm. >l
U OUB very iiirxe aud ba-iidnoniedcUivovoLumc. lealhet, raJMal baadn. el orar lOW pi^va. t3i

COOPER iBRANSBY B.), F. R. S.
LECTURES ON THE PKINCIPLES AND PKACTICE OP SUBQEai

In una very l*rgr odKvu Tolune, aailr« clolh, of 7S0 p*ge*. S3 M.

OODTKH ON DieLOCATIONS A-ND KBAC-
TCR8S or THE jnlNTrt — K.JHrJ t.f Hbaii.it
B C«er», f K »., *e Wiih ■i:<lj||onal Ub-
•flTraliiiaa bf Prmf J. C. WAiain A new Amv
rteas edititai. la ■>!!* tiia<liuii,e ottavu volume,
■lira cloth, a< abciul BOA p-agra, with nuoieiuoa
IliustraUi'iii on wnod. §S SS.

GOorKIt ONTMKA^AT(lMV ANDIllSKASKt)
Of THE URI::A»T.witbtwoBtr-Bv«lllae«liBll«-
mt* aril) !<ui|iiral Pa^(« Our laria rvlaM*, iib>
petial Kvo., extra olutbt Wiia xsf Airurea, OB 3*
plaloa. U M.

400PKR ON THK STRl'CTVRB ASD DIM- I
BAMW op THK TK!«TI», AND ON THK '
T11\MU« 0LAND. Una ro)-imi<cria|9rw U- I
traclolb, witb ITTngarr«i>a:i9)tlat««. •■ 00. '

COPLAND oy THECAf*K«, NATfRE. A!"
THK^rMKNTltF PAI (tV AN1> APOPLFJCfj
la Koc rulune, to]-Bl tUiii., utr«elolb. pp. I
BO etrni).

CI.VMFR ON PRVTtRfl: TITCIR IiIACNOSl!
PATMOLOIIV, AND TRK-^TSIKKT la

oelav" v«laMe,liaitiwr, at IM> paf>«, |I M

Ct)l.i>.SIIl.«T DK LMStF-RK tlW TB» .
ur KK.M.M.k)^ «K.j .Ik Ike aiHwu
ih«ir:^i roaaiawil, wtili laaajr >
dlUit«a. b)' 0. D. Maiaa.M O. UcculiI nUin
t«viani anil iiiifitaved la aa* lant *<tluiM.<
UT^^ li»lliet, nnifc ■uacMiaamnJrala, n.
»».

CAR&ON (JOSEPH), M.D.,

PfOfcaaor uf Materia Mnlir'a aad i'haiiaur); la l^e tloivorail]' of Pesitayli

SVNOPSrS OP THK COUHSE OK LKCTUKE8 ON MATKItlA MKDICJ

AND PHARMACY, dalivvrvd la ibo Univ«ndiv at PkBMyltruilB »Miaid Wd WVk
lioo. til oat very ncai octavo voliiin«,utn.clMJi,ul 206 p^m. >l 00.

CURLING iT. B.), F.R.S.,
SaTgeoM tv tbe Ltnnt-'n HnapiMl, KrtiMfteDt u( tli« Hunlertiu Aoelvlr. fca.

A PRACTICAL TREATISE ON PISKAHES OF THK TE.STIS, SPERMi

TIC UUUD, AMU bUKUTUM. Siound Ain»><-iu>, (rum Itie w.iid and .-..tar^r*^ Enclnk <

iMMi. In auc baudauai«ociA'«oVQ\unc,«:L\i«K.V>\^,'«iLWwigBKiuaailluMmiiMta. pfi. dC (S

AND SCIENTIFIC PU BLI 0AT10N9.

CRUnCHILL (FLEETWOOO). M.O.. M.R.1,A.
ON THE THKORY AND PRACTICK OP MIDWIFERy. A new Amerfcan

Oiiiti ib« fcanh rcTi<«d awl eiiUryed Li-ndoa eJitioo. Wiik Noton uul Aildiliuns, by 0. Pkaivcm

CoNPix, M. U.,BHthMOl ft "Pnii^iK^lTrMiifC on ibr Uii>«am-i> of Cli<i<tftin,"dc«. Wilh IIH

flliMrMioNi. la one vcrj* Iuui4ik>is« ucUvo volume, laaiber, of neatly 70U {mfft p«(M- S3 flO.

(JaM JtrntJ.)

Till* wufk bu 1k«ii (o long •■ eual>li*hr<l TaToriW, buth u ■ ivxi-bwk lor (li« l«nmvr anil «■ a
kJihUv aid tit TVOxilialiiH) lot ibn practiltunnr, Ituil ia pr«t«iiiing a uaw ejiltiin il i* only Boc^tmiy
lo mil air«nli«o to ihr vrry ^iiniiicil ini|ir>>vctuenU wbidi it baBiwciriHl. Haviiw ImuJ ihe IwneM
oTtwo rcviiiLai* by lli<^ uuiluir mncv like ia>l Aniorioan Kphul, it ha> Iwm malcriaTljr aoUnpMl,«n4l
Dc. CktuchiU's wvll-kuawii cu(i?CM'iili»ui iuiiu'iry i* a cuaraate« ilial evarjr ponion Iwa bwa liw
ro<igfaly brought up wiib ttw Inlivl rcnuli* i>r Kafof/c^miavmtiftion !■ KlldeparlwenUar the ■«>•
vfett and art of obsli^tno*. Tbi; rrcrui <!«;« ol" tko Iwi IXiUiii nliliiM bu aol IcH nQob •! oovaltr
b« l>c Amci^ian editor lo lAiriJaiV, bul bn lta« DiidtMroroi) lo insert whalevist ba* aiuoo appoarcit,
(«gv)ker with tueb tauten a' hU (.■XfH^rxriK^' k^« >hLjw-it tiim w»ul<l b<t tlM>raUd ^r (bo Ani«ric«a
MUilMit, iiicludiuf a larfte mitnber <if illualralion*. Wiih ibo Mncikin ff Ihc auUtof be ha^t added
in UMt Utrm of as appendix, Munc ch«p(vr» Crutn a Iiiil« "ALuimi fur Uidwivs* and NKr«B#." r*-
CMlif iMuedbr Dr. Cbarcbiil, Mtcvinir rbai itu dvuiU iberv prccntv'l on bardly f«il to prove of
MlvmnUm W im Junior imt-iiiiuiwr. Tns r4»>ili of ail tlteae oddiiidii* i* ib«( ili« work n»w cl>d-
Mina fcUy oov-ibaU' nioM mailer iban ibo lam Amaricatn ediiiun. wiili nrirljr unv'hnir inuw ilia*-
iraliunt, aoihal nnlwilluilaBdiftglheaiMaf a ■iniilW Eypa, lh« voliiai>] iKiatuinn slioort two Uiiiul'(i<l
jwnw inoT* than bHbre-

NueffuTt baa btva vparrd to Mimre aa iiaproTcm«Bt In Ihe mMrhonical oxvi^atioa of Ike work
oqual to Ibal which Ihc Icxt bo* rciYived, OBil Ihr voliinio i> cuiiliilcally iinrwiiilcd aa one of iho
biiMlMftnnI ifatti hiu lhii> far biten laiil k«tiirc tbc Ammc«n pnifcn'tun', while tlio very low |>(io«
•I whi<-h il itioNrTMt ahiwiid Mcnte lor ii a p^aM m crtry tcctiirc-rvioni and on rvery oSoe lablc.

A bMMr ^Aiill la wk{«li Ui Irarn ItiM* mpnrMBl < Tlie ni>«t poyabrworkoa nMwtfery •*«• laaaM
fniaUwr barrooEiBrl ibna t)i Cliurrkill'i KveiT 'ciiin lh« Aiucr»eaBpiaaa.*-CAarl«MM> JbJ. JtaawiMj.

p*(e i>f It II fall r<r laiKsctiua; tfer opniKin «( ■(!
WTllcta of ■■(liiiih; 1* ffivrn •■o ^a<alI(Mi> <i1 dlA-
cully, a* wdlM tec dirKikooa a«d adne* »l ite
Icamcil tutMW bini(«t(, u> tvktok ha adil* llir rmiull
«t ■lalullral inquirt. piiltiD|| italKlii-a tn llimi pin
p(T pUce aif] 1 1 via I liiein incir C at wogiil, aait so
Mr>i«. W« hacF sever md ■ )i-">k iniirr fn^ fn-m
pri^ftaalmal JialoHf UiiB Dr Oiurrlnll'a It h|i-
pcara tob« wtitl«a with ihrtfiiflil««lgai.if abmili "n
■atllHM, Tts: tvgtv« all taal !• tnawn on llie«at>-
)ivi 1^ wblab kc tt**», bnib Iheoretlcatlr and ynri-

u«allT,Mid iaBdiranMaa«lio»lai«a«Df bia-'wnu

be tialiruRB will bomCi uwdml at'tcneo, a>d Utut*
tkt ttMyof ibr pali'nt. We t.ave and *oii«/b to
Ciavy 111 Ihr prTifrxuia ittal tliia biN>t> of Dr. Cnur-
ehlll'a l< •itmiraMr •iiitrd fcr a ti>'( rcfeieaee
fvr tkc ptiiTUU'-u", a> ■■■■II aa a Ii-ii-li-hiX i"l Iha
•tiailmt, ari'l wr li-rirf> >l may br (Xlr-natvrly (Htr-
ehaa(4 ami^Dcat our ludffa T<> ih'iit w« nival

iiiwV. two.

T" b^Mt'tWpraJicffna book Uit baa rM«lY«dM<h
■arknl M|T]ir'>liaIi>« wnulil \>r auprrlitiiua VVcnpnil
•■tj' aaj. liirrrAxr. that a( [iie Krai cJilion waa
Ibeasbt wrlliy ■<( a favuraM* rfi-rptltin bir »■?
sadiml piilrhr, wr E<«b roEilitlrulIv aliirn that lliia
Will be f'-uDd ifiueli ri'iTr i,i Ti,,. li--irirrf. tli<

ptai^tiliiinri, anil III' • "' iiar

to l!a iiHRri, aaJ dci: '. la-

(nreai bimI iaatiucliiifi .i:-i^i.

ntiual and pr«fti'--iil njiiwiieVy.— if ntJi* ^aarurfp

A work iif very (rnat n^li, aad «anh «• wa naa
•onfidratly rr«i>iiiincMd tA tlir <Ib<I]I or i-Tcry iibate-
trte praettttonei.— £*ad»a HtdKal OmttiH

TbialieerlalDlr tbcHoet perfect arairai <iiaai

It la the brat adapted fi'r Ihe piif[fiH-> r<r a tad.
bodk, aad ttiat which h«! wh'^aA nfcriaiiii-* mnfint
Wai to in* bdok. ihimld arln-i m prr<>Tn*« in all
•ikBtN'-^aaltMw UtiKtl aarf S*tii(»l Jtmm^l.

■T T"« «A»« AttTMOl. (ZaW/y Puifi-iA*f )

ON THE DISEASES OF LNFANTS AXD CIIILDRK:^.

Were we redU«iM) to tae aMMMtr mt k«*laf Ml
HM work !■□ inidwirrir, mid ptrmilUd la rit*eai,

we woald muiHitnim^lr lake Ckarehill.— IfMMr*

•farf.aiUSiof JamftLMt

II It knpiMitltle 10 Btneeive a okt* aietul aa4

ilaRaat laiaaal tkaa tit rkarnlillt't Pranic* of

CctlaioJ]', in <iui nfiUuim, Itie Tfry beat wait oa
beaab>MIWhi«ke>i*t« — ^. T. daiaaliil.

N'l w-vk koldi a liifher piwill'iD, or la more de-
■ar*ti*t at bciDR placed In the kaoili of tK" <)'">■
Ibe advanced aludc4il, ur ibe praeiiuonea, — M4dicml
SxMMiatr.

lVerrii>uBFditi<ina. oader llie rdltnrlal aapMvl«(«>s
nt Prof R. M Uiiiliin, ha«« brcii reveivail wil*
laaikod faVor. ami Iliry •l<arr(nl iij bill llua. |< ■
p«tnl«i rro«n ■ vety Ut« Oulilin pdliiiw, riii-roi:p
reriicd and briiuglil up dy Itic anUiar tn Ibr ptravnl
tt«W,daca prraeni la ■■uaaallr aMurate aad abia
axpoaillaa ofcmr iMpixIant paiticaloi embrapcd
liilb« dcparliBriit c)f inidwiferv- * ■ Tkee l<writcai,
■lirrctneaa. aiid prrctinw of iia IrArklngi, liifriii<i|
Wilh lfa< (fral ■m>-unl oralaiiilira) leaearrli wkieb
iti teiiaililbita, bav* aerrnd tn jtlami 11 alt*>*ily iM

mnlial aoleace —t*. O, IOd.m»dS»tg. J»tirn*l.

la oar uplniua, it fonaaanaof tbabcet l( nm lae
vary beat icit-bink and epitameof obitelrli* apirnra
wbieh are at r'eaenE poaaFia in Ui« Kn^liah laa-
(aage.— llf«a(A/|i-revraaI »/ M'ditat Stinut

Tbcclearauaaaiid pr*«laiuriii(ilyle ia wiitebilia
writlae, aad lbn|[iealainDual'-f tlati(ll(«l r* (earth
whieh it cmtaina, bave •eirc-d li) pla^^ Il iii tlie Sol
nutkrif wuika In thiadnarliMalof aiedjeal •eteiife.
-n. rJtntimtffHidUim*,

Few ireatiaeawiU bo founil betUi adapM aa a
lext-bivk {■>! lh« atuileal. nl aa • uuaunl f>ii tha

frnqnent OaaiiltutMn of Ilia yoBBf praelJUM<f.

ilmtTictm Mitiitai Jtmrnmi.

Sooood Am^ricAn

£dii><ui, r«via«d and •nlai^^l hy ib» autni^r. Edi(«d, witli Hutm, by W. IT. Kkatiho, M. D. !■
one largf and haadaoilM voluini-, avlra c4oth, of ov«r 7W pag««. U 00, or In l«Uh«r, $S 2i.
Id prepariaf lbi> work a «r(^t>nd tuna for Ibn Amerkaii prureuinn, ih« auihur ria» apor«d no
labor in fiving il a rer^' IhoriHif h wviaiin. introducing aevFrul iicw cbaplnra, aitd rewriting Mbnia,
wtuleevery (MWtionof ibcrnlufiM Iwi baMi iwliji>rl«'d ton vn-rrc wruimy. Ttie cHbru of Uw
Aiaertcaa MiTor hare been diicewd to aupp'yiD^ aiKb laiWmBiioa relaiire lo matter* pN->tliar
Id tbis Goautry aa mlgfal hAW eaoped ibe RiteniiiM af M>n auihiir, and ilir whole may. Iben.-

rieia Proftawaa. By aa allarativn ia tba ain of lbs rngfi, Ihoiw vcty exveauva addiiioaa bare
b«M awMtiMpfcleJ wiibow tatduly iaer««Miic the soa oflu work.

ar THi *AiiK AitTaoK.
ESSAYS ON THE PUERPERAL FKVER, AND OTHER DTSEA9E8 PR.

CULIAK TO WOMEN- Se-leciedfrum ilw wi-hingaot Biiii*tiAwV«» u«^v\vv«»v.>\'»e Am*to\
IbeEifblcvatbCeaitiry. laune aMtocUvovtAuine>«Ui«<A«h„<>VaXiuu^Ufe ^bva. %"i*.

BLANCHARD A LBA'S HBUICAL

CHURCHtLL (FLEETWOOD), M. D., M. R. I. A., *e.
ON TFK DISEASES OP WOMEN; iaciudiDe thtwe of Pregnuwy Ani ChUi
hrd. A iipw Aimriwiicdiiiuii. n.-vi»«d by ih« Auiiiof. Wiih Notcn knd Aiidntoti*, ti\ 0 fug
vivCoMniK, M. D, author 111 "A Pnu'iii.-iil Trcaiiwcit ih*i lUtitw* rrniflrtfrn " Wnfc ■■
r<Ki«i!hmrBtiaii«. In anrUrgvandkuKl^nmeuviaTDTotitBW. Iwilnr. ofTOI [Mftt. 93 00.
Tbia nliiiuo ol Dr. Chutrhill'i very papular Irenii** nikj' ■Imoil ba t«rmMl k ■•(W «
Ihnroiifftitf ha* he reviard rt in FVi-ry |ii>rli(iB. It will tw Ttrand frtuty milaigril, and oi*

brouf hi lip t(i iht- nuMi remit ronilittofi »t th« pubjpvt, while ll>r »rry band'onw M>rM oj

tlMi* inlrodiMCd, relU«4«ntMig aurh pkUtological condilinMii ■> ran hr aoimrMnly ponrayrir, |JS
Kniml tetwc. UM aftifd r>ltiftb4e uataiaktv to ikr ymuif iirBciiiiuaer. Such aAlin>aia u
pnrvd <ta*tnl>l« foe tte Ancrtcw aluiteut baw tirca OM-Ie by Ihe ndiiar, Ur. Ctnili'- whi^a
atortMlimprpwfiHnii inib* BivrhMinl rxevaiioii keiiHw pacirwtili tbr-adraBcvin nllulbci K«p
Trhich the Tolume Jiuj uadcrgono, wliik llwpricv bubeea ki^ ul ibf lormprverv Bi.Hhratoi

ll (HKopriwa, unciiinllnnalit;, ooi? of lli« ni'Ml Dx- ' pjiini : l i >' iBi>«ttf . u t

tet «»d ei)«apr«liPiiiiTc pxpo*lil»ni ot th« pttarnl nou \, .-, li^ Mti)

•Mlanf medieal tiiii>wlri1(p in raaptTt Iiiihr niaeaspi sail II

of womaa ital haarei D«aapublLahed-— itn*. Jaura.
Af«i<. Stfiu**.

Tnia work ta thp ■•■>•( rtlHMs vfcleh we poneaa
OB lb I* ■■liirri- mitJ II ilr*n*nlly p'lMilat with Ifae
prufcaMnii-— (.'atrjfffva Mitf. Jturnal, JbITi IM?.

Wc kooiv ii( noiialiiot wlm ilrwrvca lliai apfiKi-

Mtiui, OB ■■ tiM iliieaaca ul CcUMlca," l« Ue aame

JrnU !•• • iiiin:nnl«-» in .!• naiti

Aa ■ r(iiii|irab«aialVB aafeoal ftn alii
wnrKorrcfeieMCvrc" r'»tii"««n.lt ttifs
■ithm lka( haa cvci luanl iis ikK aanw aab
Um ililUih pteaa— A «»•'(■ Va4f «. J*»'t

■,m aMi

DICKSON (&. H.I, M.D..

Pinfofpot nrPrartVoei-r Mttliclacln ibe Jrfertuii Mrdical Uidldf a, Phkladalpbla.

JSLEUfiNTa OF HEDICINK; » CompeDdiotui View of Fxtholoey uid
pdMm, oi \ht Hiiitoiry aikd TrrHimmi of UJM-iiwd. ^re^vnO rditl'«, rrvi»«d. Tn oftv iMtft i
hMndNMnfl ofiavn Tiilum«. ol 1M pagfrK. lealhRf. (3 70. iJu*i /jjha/ )
Tke alvady dcinaod which hu v loon cxiiaiiaied thv Aral «diliui of ilii» Wi'fk, •'iiiSr-iraiJy bA
thai Ibe uulbor uiii nol uialakrO io aiippotin^ Itial a VoluUM of Ihia v>iaraL1i:r wan (vmlrd-
alcmeniary manual o( prvcfiw, wbit^b aki>ii)d praaeitt ibe lcidlB|r prwdplr* of nwdicrnr Wiib
praclK-al tvaiilir. ■■ a rondeiueil and jwrapioiiuw nwww. SiandnmRd of mweraav^ '
and rriiiileaa fpr«Blaiioaa, ii cnbodi«t wkal ia moft rt^niaile- for lie aiwdisMi i« laam^ an
aamv linte vrliai ilic activv praclilwacr wants wbvn ubl><tcd, ta ibo Uaily oalU uf k<> pfii^it
Tofrrth hm nii>ini.<ry vn *pvrig| pwiota. Tha vkar and alinHriiva myta o^ the auitxi* raa
whole cB-1' I'f i:iiiiiipri-lii^(j>i..>i>, wliilo lita Umk «> p( rivw |hTv* (■> hi* l£*i:biii|^ ati aiutuKit]) I
wticiv ■i(-kiii>wli:(()(cd Fi>w ;)tiy>ii'iiina, inM«ii, hav* bail widri <^|a>niiBitm ibr utnervwlMm
exyvttoRf*, and lew. perhaps bavn uned tbria Io heller {mrpoM! Ap the rT»ti)l of a Itw life i
voircl In M«dy aad prttclTi^rr, Ike pcriwnl «^dlllIln, rrriaed anil liruu|:hl \ip Ui Ibr dale <4 poUlfAli
Will ilniibttnaa maiaiain ibo rrpdialkm already iLcquiJoit as a con(lcni>rd ami vtMiveuivul At
texi-book on tbe rraciice of Modiciue.

ORUrTT (ROBERT), M.R.C.S., fte
THE PUINCIFLK.S AND PRACTICK OK MODERN Si V. An

fliict ri'i'i-Fcl AmcricDri from Ihe ci]L'lith enla'geil and iinprvtrcil LctHkia • ii<lratrd

four hlindrvd and lhirly-IWi> W(io^-cn«r«Tih^i> Imtae very b»DfeoiBet)'(>{itkCilucUvu

leather, or ni-arly 700 taif« pUKM. S3 50. (Jitti luurd.)

A work wblob like llKcnr'B ^rantRV b&t fur fomanf fearamiiiBHiiMHllha|toajtuxior«
taf favttflKi wilb alt claaMM ofthr prolo>i<ii)«, nreda no f-pocial rveoaMnrndniiwi lo aliract al
f(> a rcvi>cd odilioii. Il i> only nniiaiary in <[ui« fbai lor auibor haa »]tarr'l im imina in fa(
woik (t|) lo iia well e«ini«d rrp<ita<i<r«i of prvseuting in a ainall nrnl p^nv'
rrriidiiiuii of every il«pariiiiFni ui ^aritetj, oonvideivil InmIi a* a Bvyracv m
Mtrvlc*' of n «-<;>nipeirtii AnMricnn rdilur have hr^a cnifiluyeH lo utiiudur-
hare ♦•chprd iIic nuihiir'* otlenliun, oi aiay provp Ol i>ervirir In llie An ■
•STvrfil ediliuni bnvr appeared in IvunduD liaiT iliv i>*iu? ii[' l!:': Iii^l A H"
ha> hud iht' bcuelil of rv])eatt.'d frvimiiDii by ibr autlnw -'
liiipruvemnit. Tlw exiL-ut of lh*-»e addilioii* may !■• r
ahoi'l iitie third mtirtt tnallor Ihou ibo piv\ii>iu ■^'■^•
aditpi ion i>t a ^maJIer type, Ibe paMahftve b«ea m
huiidred and fitly woiid-ruti haraTicsi ftilded lo Ii '

A BiHiked iaiproremeai will alfn be pefcaiwd lu itK- irv: >.
work, which, pnn>«d m ike beat tiyk. mi m V iy|w. and liat-
rFipifd* exiafnal Aiii>h; while al Ibe vofy Ivw priCB uilXM] ii
Votumca acrruinU lo the proleaatuo.

Thia p»^ttlar aoloin*, nt'-ar ■ nmit '■"mpri»hi>n»iv» ' BntMnff oTrntr "itartlrat Imjmffinpr hla hmrv mttU
Wi>rB<ia aeraaty.Iiai acde'L ' .<'".'',,,,,. i . .^

im^'aeaimia.BaiJ addiiint. . •-

Ilia praftiecof the ait bar' ... •!

the I at tit ( •cord bIkI citiiaivan.iii ( i| t:,. iij»riii>.T|i thi\ iMHr ii ii'iin
(n tnT(irrlil(mpo<a>B(Fi'ti]iriikirii'hi«hiy. The
diiictliiUdni H'" ••■ "-Ir-Bi ■nil pi.ijri»B, anil ttin lllna-
lialit-ai »> u><ii>utr ■«< auinif.iiK*, laal the alodml
ean knit mm iliniruliy, iriui iiiMiuincjii tnhaBd. aad
l)BC<k hy hit »<If. iii-el Ihe drail Ixidi'. m abiaiama

■.■t»
■—^'?f'

ol maettilm rf i
n to bo Arairtd •■
jM of iIm ohiaf*

— /....Jd« i.i.

Io el<<*la|ihlalwii><ni>ilf«, u .
iliatlr na rvf r tbia miwi aiifu.

Iiaad-b%>'>k. Il mttj t>ip>v* ■

uo... nyni. a.«c. M«f ine drad i>..<iy. m abiaiaiu ""'l" I" f" •t-J'Ul "f "I'l" V '

a pr^HX koDMl'i'ir anJ ■iiRl'^kri uci lu Ihlt biu»£ pfeUiMnrt whi "wy o-t i vr

»«rl»Mad«Iefaittr.'in..rF»«lii-alWur,tl.,i..— Brif|-.A HtW"-^' ''' '"•"'' "1 ! '" "'

•»f Fa».J,a*f.Ji,».(Wraff, A.rt#W,JaU 1«0 L—dM, Mi,l r.-.M«^i,.-.

la tlia pt^tfBl niitiiFn Ifcp aultof haaratirely rt>- ! In i
WKiMi naav ••( Iba •haftcit anil ti«» tiiF->cp»>ainl Mat.:

Ibo vandua iiiipdivcnmia aM ftMVVtoiu iii tmiAatn .nt v'' - - — — ■ — —

■Br^try. 0» caieliilfy fvwi iw« ttiw^ia* tt»% 1a<a>a«^»j »ua.i.*««t.*,'^.^ \»^.

AMD 8CIEMTIPIC PUBLICATIOMS.

DALTON, jn. U. C). M. D.

Pr<if*«*oi of Pk)i|oliif f m tl)« Ci^llcitn ol PhyuRtan*, p(«w Ynrk.

A TKEATTSK ON HUMAN PHYSIOLOOV, designed for tbe mo of Students

•114 Pnirtirionutfl or Me^Uelne. 9«eiHMl cditton, kvu'«(I tad ejnlar^d. wiih two bopdttd ttnri

MTeiMY-flM i[|u9lrmltoii« on wood- bi «» ■my bmnlAil ofIavo valuiue, of 100 ptaca, «sim

«tiMb. it 00 ; l«allM;r, ruwd UsiIr, t4 SO. (/lut iMitW, iMl.)

Tlw gfeiveral Oiror wbirh lian »o f mxi i>ihHu*ml nn Fitiikin of ihtt nmrh hn« nlKirdml Ida amlior
Ml nf>riiiiiily in jrii rpTi*ii>n i>l tapfiyinic itm ilHSririK-ic* wbirh raldfiit in rh« firmer voluoir.
Tbtn ha* i-xuvil ibr iRM-FliiHi ty{ two ocw chiigiipn — t<ii« on ihc iSppi'iu) .'Vii>», ibe olh^f on tin-
Uiiiion, KthnUlion. anil Ihe FiiiuMiKos I't lf>f LymphniK; SyMrm — (rsidt!* niiinf-roiia orltliHoii* ■•f
■iii&li«r Biiiouiil !>L'allcri-<l tbroiwh llii: Work, niil a (Ci^uirfal nrVi<iun (l<)-i«nal lo brint II lliimnniiclily
up III ilic prcM-'Dl ciiaililiun i'( ilie tr-imrc w.lh rrjcard to all poinU W(iii-)i lOay be c-HiBidnnl •*
dnftnilrly MUlrd. A iiiiioIict of new illii*lruliiint ha* brttii inli»i1iir«il, awl llie work, il In (Hinnl.
IB it> itiipruveil toitn, way cunlinue to oofflnuiad the cun&l«u«e uf Uwae for wboac u>« ii ja ja«
l«ndcil.

Il wilt bf-arvD, tii'ffntr. iKttl OrDallOK'i h*tl ' <twB mijin*' ■■ ■ -•■- ■- ' -' rniilf. lof«tli«rwtIll

rfiiila hair brrn ilifrc-teil liiwaril* pnlrpliug hU a ilciirr !<■ i . trirU •iiitai' iirSrifii.

Wo((, I l>V Kititlliiika arc nia>K>iJ li} in« inrnr r>a- cina In fli« t rr-itilr naJc in* prr-

tare* whiab eharaclniKr I1ir irnminiliT nf titr viil- icnl tian a Dri-r».i)' , nni <■ nill an ilniim hv cTrii
a<B«. a^ roB<lrr il by (>r tli<^ muM dvunblt irsi- mnra t«|teny auaittii Mr Una inc Km. That ii ,m
bout (>■ |ihyatii4i>f r to |•lal^c in Uii- baiiila 'if llic Wl mcKlir ■ ic{)(wl, vrtll be iMn rrum th» ■■ihiir'a
•liMienl WLick, au far aa w« ar« awaie, extala in , auilcnMU uf (he r<>t ovvini rr>«ci^l Mldiu^aa «D<t
inc KngMili laii(|u«f r, m ptihu-t ia no] iitbcr. W« altria'iaua wliiuli )ib ha> n>*{le. Tae prpariii, lit*
<)t«rafi-re liavt K'l neiitaiifn in rccoaiDwndiKf lit. the Stm c4tlt'm, I* prirt") lu ihr liiKhrilalilc.-f'ihfl
Daluiu'i buok f'lt UivelnHra fnr whicti il ■■ ialru4- ' prinlcr'* an. and Ibp lllutfiaiinai ir* Kiilr aitnii'a-
•d, lAtUA*! M wa kt« (bat it la belter a^'ui-ied in Mr r»r thrir elrnnv^t tu et|tr«aalBir viaritv wbal
Ibcir «(aibuaoy Mhar vnikof Ihc liatl in n-Sirh lacir aiitliur ln;a»d(>l — ilaiian ||mI«<mJ aad Kar(i-

Micy hav« a«<*M.— iiiuri(«fi Jawnial ^ M< MmI.
£(»■(», April, lUL.

It II, ibei*r<ire, ■« diaparacemrai (» ih< maay

col /awmoj, HaMb », leill.

It iaaoAMCaaary tdti'BB ilrtailnf lfeRadilil[i««|
anlt««U Kiaay,ml ihry *>r*ui»rTaaaBa<l iw^irt*

tbrlivih-iul llic wiiriil, al t\u tK%tr.n rif ■>( llie cu(-
rcflt yasT. Iiauieaia maipfcbaaive hiil »>iip|i
diFlinn, Itn farla ratnbliahr^ bv ' ■ -'-i-if, or
other niPilii^ o^ tfTnonatraiim, - < au

nBilrialomlatitr maaacri boar it ir <i <|"it»

fftnn ih«il(»ciiMl'>n'i(oiftrt<l'ilir il "■ -. !■ -mia.

Here ID ll K uDiijU« ; aoti 1h<ap riiaraiMf'iialiea rrn

biMib* atioa anrajol'iiiy.nHat BX«rltrnl in ihrlt lUit, anl, anil aarh aa will imitr Ibo wivM atill n-ra
taiMy ibat iMiiia'aialMflalyMir.ihil i[i)ri a* the i mltHbleaadaecaptaljIe in incpruraaunnaaa learn.
Bn*n(« •• Il uraa kauvti fi Ihv bil |>SiI"a"|>lip>a i ail aail 'irlif loal tnaliaauD tlii**M<iin]<»rtBBtbraJurA

I of nf^Li^iDfl- \U liiBl wa* Mill in rtH9m<tt4*\t"U
: nf (bsa«li<agiipiiriK«lli(tBlili{<i,a«4lkr Hi[kenor
alyico? Ibn illM*lmlii«i ap|>lf wilh tiual ("re to
till* Nu brlipf anirH <>o phf>iol'<i|y e-ui tie flu^ni
in llii^ lisn'l ••{ llir liailcBi.— S(. Laai'j Mtdicai amd

Su'KttMi Joantl, May, IMJl.

Tliraa aJdilii>n*, wbila IrailfylBfr l» tJio karetnf

ier»l-
ai

I ablrat

«»trr«i |>«ifii>li«;i n' I, ■vvi'<;iir; anij Una in turn ia '

flia baaia I'f inliiiiiai ilipiaiiruli'a 1 a>i IliBl uaih >|ii- „^ , . . .. , ■

«, iu fact. b«»J,ir. ..f jtiiiu iinpjrlaui-e u. the Awe-^n rJl""n rtf tbl. J™n-.d(y p.^nl.r wmfc

i-ci£.o-«r- ira-«(. M«V. lit. »»*(•, Ih.^ aork,,. haa aiiptl.p.l

Dr. Oallnn nrrda ni> wntdof pmai Trinn ua- U* ' ri>iapictel< luHiUril liia draif a i^l ,.'
ia ■■Iva'Mily rccxgBltra na ■•nmg tha Arat, If B"t ' profraiinB a fdiabla aail prKiat I'li i . i

tbe ven ^lat, uf AiaFticaii fihramliigiala niiw liviaf . < whicii wc i;iinaHlei Iba beat uulluie i... i

Tba firal aditbiB of bU ailatirabli wurkappratedbal ! otf wblel 11 traata. in any Uaf tia<r.— .\ . -■•.•■ •■-••
\wa yaara aikos, and tba wlvanca <W aeUsc*, Ui ' Madlir* ftlrarf ih»<aM, May, iMtl.

«r tt a Mil-brt,.* w.ih-nl a (it.I. fo. Ibuw who ,„^ inrfu,(,. ,./ Ua a.ilinr. reairrtha l)«n« •leral^

*calle in itnd, p - -nt aei<B« aa it l. knuwo |„|y a.pfui, aa Hip mn.t cimplrt* Mp-.at ..f a Hi

W il* le-iel «"■ -lOfi- And II ■ pBrti- ,n«, -r which Ilr, X>all»a <• .l^uDIIaai tbn abira

"■-•»' «'-^> f" '■ "t I""- r;iUBd.ti..n .If ,e.,„,rauiirr «b tliia aid* .J Ibe AUaalic^fUaa

DUNQLI80N, FORBES, TWEEDlE, AND CONOLLY.
THE CTCLOPJEDIA OF rUACTICAL MEIMCLNE: ooniprisin|;TM«tiB(» on

• Uu.- NaiH-e abdTmaimDiil orUlMueii,HftMnali«ilc«,ttuil TbenpeiUicB, Di9«u*ca of Wumrs

kivd ChiUlren. Ml^JimI Jitrupn>itaM«. dee. fte. tn four \ut* #D|>er-royftI octkvo voliimva, vf

33M di>util«-ukJui»iMHl pafV^ nimnfrty xid bBadaomdy bound, wnn raised baada. %Vi W.

•,• Thi* wmK cwmniij- no lena ilian (i'lir hinKlmd and ciiclii'^n diMHu-t tnaiiaeb, cualriliutml by

■Jxiy-«iRhl dialiugiu'lu!*! pbyalCMS*! rvniioriiig It a. ronipWiv library uf rvAnooa fix Ibe etnmirf'

pncilliunef.

Tbeeililiiraart praeliueBwaanf Ralabliabarfrafia-
tBlluaiaad Ui« III! M r>ininU«lvr* siabracci auny
of Ihe laiMI ratinaBi |iri •((••■,[ aaail Iracbcra nC l><a<
iam, IMiabargh, Ual.lin, aaU Ulawow It la, lO-
(Icril, il,r Krrac ninril <>i Ihia Wort lliatllMpriadpal
artlclti Xww: Mrn farola^cd by iitaeutlMiri* wbii
have But naly d«VoWaei|iecwl«lt«Btll>B t<,>>l>e4l*-
oaava aboal trbich Xhry bavc wriitlaui. haL bare
alan «jay«d vppurlutiiiirt fur aa csEraiivi' praeli-

Tba aauat enonpUU) worb UB Praalleal Unli«uie
•iluiii i-r, at loBit, la imr laj^uaca.— £i|#Mt

Ibdieai ami Sntgicai Jctmat .

For r«ferenee, It laai»>vaall prle« loavcry prao-
ttderaai.^irraMna Laaeal,

On« of tbp moat Tnlunti!'' mnliml pub lira (i(«a of
Ibe day —aa * w^<rk erf ferrirorq n :■ mraluabla.—

Vitltna J»BraAj •/ Jtfific»uaa4 5arKar>.

eal B«)«aiPtanirD wilb llicm and wl^'nc i^rputnlloa

It bai brrn tt' a«, ^ii'h ■■ l-a'ii'f anl imchn, a |i^iri*t (h«aMaraBo< uf their ct'inp'ri-n'-) /uiilj- lo

work for riraJjr anil (rp«j«ral irf'rcBi'e, i-ur m whirli aupCHiat* ibo i)|iiniriui ni i«i.rim. irliUc n atmij.t

■oOcra l£ngll«it niediciur iiubibiird la tba BOM . tuimwa donidneawlll hlfh aaHimltiiUiuril) —

aivut^eoaa li(hty— JbdicaJ Exmmtmtt. I jlaurtiaia JfarftnlJaanMl.

DEWKKS'SCOMPHFnF.NBIVK 8V9TKM OP
MIOWIFBRV. lllurmiMl tnro«M«luwUcui)a
and nmiy anitiaviajtn- Twelfibrrfiilna, wiib Ibe
atttbor'a Uat tntprorcotrnii aed fi-rrectinoa la
auiiijeiair«*iilanwi,eiirarlt>th.i>(IKiO|ia|ia« *.laO.

BEWEBB'I TREATISE ON THE PHYSICAL

AND MKDICAL TRKATMENT OP CHILI)
RKV. Tfeclaat fsIiIkki In (mm rulaoia, imuvp,
rat's eluU, IMS (w^M fs W
UKWKBS'S TKKATIHB ON THE UIHKAI^KS
OF PEMalK^ TMitbMliiii<« la «ne ralufac,
MUro «xir«aloUit4n(«%Ba,wUk^VK%K« m>A

BLANOHARU ft LBA-8 MBUIOAL

DUN0LI80N (nOBLEY), M. O..

frvht^atof IndlintMnf M«dirli>F in thr JnTiirana M'lllral C-'llr^, PtaitoCtlpklL

ItBW AND BRLAROBD BDIT30K.
MEDICAL LKX1C0N; » Dictionar; of Mfldical Sawnoe, ootitwDiiie a

Kxpliuiation of ihr rmriuti* Siihjri-I* and Ti.-iina ol An«lc«n)r, I'taynKriacy, I'o'' ' r- M\
Thcrapputica PharuiBcxilofV, PharniBC-V, Sir|r«ry,Obslelric*, MnLcal Jarb;<
&c, Nulirpf>orCliniiilr*ndor Muirral W«i«n>; Forraulc Toe Odkind, Bmp. <
^J*rep«nituin«. frf- Wiih French and oilier Synooyinca, I1«vt*«4 aud Trrjf s'caiiy
tin nn<' f«ry large ard baud-oniv uctuvo votune, <ir OPS rfauUe-oolannecl pafca, biMDsll!
■Iratifly bound m katfcer, vriib rai*c«l buids. Pnca S4 00.

l>pvHal rtara bu bcwa davoUd in Ihr prrjioraifMi n( iklavdliion ioi«n4er<t tnwcm.
wonhv n cciiiiinuaiic*' of the very (pniarkobln Tnvor iBliii-h Ii ha* hiltwrlo vnloyeif. The ._,
■atp 111" YiriKny Inr^r Ffhlmn*. and ilic riiiiHtitfilty iiirrtrn-inD ilrmand, itbciw llial il It nvaHnll
thf pr\>iv'-i"!! o<> tlir Klnti<lar<i aiillmrity . l^litiiiilatrd li}; ihii tact, (hr aultuir ha* rikiir^ri <
prr»<-ol r<Ti«iOii to inlrtiJiicr' whatever tnisbt be nfcfwat)* " lo niilie it a aatif'

erery t»rin that haa b<^Ml Ii-^ihrnatiul m lh« »i>itieiicliature»r iIm M-ienrr " 1\>,i--n<m
larirv ■Jdllion^ have been ^^und rciiiii«'ite. and lh« I^xlenl of (tie auiliota iBbof* may )«

from rbe ftri that abAiil Six Tiioir^jitrD r iibiiTt* and Irrms b»re been iiiinMliK«d ibrui^li ,

dehiiflhe whole ogmber of definiiioo* aboiil Sixty Tiioir^Am, lo araonmodiu whu-ti, itei.
ber m pa«e> lia» been iqereaaed by nearly a bundled, aolwiihuandlM an ealarrrtami ta tiM l.
of the pace. The iBinl(r«l pre«ft, buili in inin coiiniry and in Encluud, W prooDiiiired tbf ww* I
di>p>-n>al>lr lo oil ax-dicul aludeaiii and praplitiiifutr«,aBd the piMVM ioipRlved f^ttod vriH KM I
Ibai onviablv rejHiiaiiiin.

Tlip publj»her» hnvp radeororeil lo rviidrr fhe in«cliaiitcal exemlinn wonby of a vuliini* ol I
uiiiirrri'nt iint' iii dnity trlFr(.'ni.'e. Tht yrrairiil rtiv tin> bi-Fii e(eri;iiH!d to <ili(ain tbe lyp
accuracy •».< itcn-KXiry \u a Wiirk of the I'lnd. By ll>« ■mull but exceedingly cleai Ivpe .
■a Idimrnir amrainl nl tnatler i* cixiilrnwd in il* tboU'tniMl amptr pntte». wtiile the biadKi
Mind strong and ddrable Wuh all itie>e improT^menla and Fo)arft«ii>MU», the pTMa bea I
al Iht^ lunti«r vrry muderale rate, plafuig il vrtlfata the reach of all.

Thi* wnrk. Ihx appnniiir* iif thn Kfrarnlh «i II I inn '
Ol ^r^t*(l, 11 hat tirti'tuf i>nf i5uty ■nd pl-milr* f '
arriai^nni^, U prrlmpi ihttttiiai itpffiiitnii • itcio uin^n i
of Iii^iir and nruillln'n In Mir>lii:al lilrmlnin. On'
w»uliJ hitilty mjiprinr nft-T p>ni«'ani d»* iif (hr pt»-
enli<i« KiIitKini. wlirir ivr hairr nrypr r«rlri< to fiiiil
■ tMffiplrnil|- fnil Ftflaniiiiiii'^PvFr] mi-riirfll Irrn.
thai tf) Ihia n9ilinn **dAoat jij; Ikftaamd aw^jnlt
aaW MFiKt *a««acnia44l«(," Willi a psri-rol irvmon
•ail r"rnirli<ai orthr valirr wi>rk. Il )■ im\y ar^ti'
aaiT iFi annnun^e tlifadvcat of iht* rdllloD In owlic
11 «ic^iijiv Ihr place of tliiF pTcfrt^jrjT 'HJr on ihv lablf^
94 rrny inKllcrl man, »» it i» williiput.f'-oljt Iht liril
aS'^ in'tat romi^rchcstiTP wr>rk oi Ihr kird wh^^h haa
■vor a]>p«ar«d.— £w^ai« JWfdVeiira., Jan. IBBS.

Tlic irixft li a mrnurnelil of palleet naeareh,
at^tirul )iiil|rmr«l, and va*I |ihytii>al la Inn, trial will

Krpfia«t«' Ihr name nf ihn aulhnr tnr>K dTvHDally
an any pi>«*4tjlr riavirv of ttr'ne 'ir mruil. Ur.
Diingliinn deanTTM thi; Ihnnka nnl iinlr ••! Ihn Aaaa-

rteaapRtfNaiiiB. but of tn* wfi'-l« mniiFai wdiM,i —

Karlk in Mtttito-Ckir Airtttr, J*» IMi^.

A Mwlixal PtallooaryhaltaradafilKl for III* want*
of Ida |rrofcaal<Mi Ihaii auy Mheianth which we ait
apqiiainimi, anil i<1 a vhanrirr which plaraa it far
atiir^r riiiTijiariftrn Hnil ei>ia(Htlitlrib-^iBi, ^airrii.
Jf<4 S!Hnin,J»B IH».

Wf ored nnly aay, tlinl Iha addition »f H.WA arw
car Ol a, with ihrlr appHmpanyilic 'i'liniitoaa, ina} b»
•aid iiiriieallluir a ni-w wi-tk. iy itirl^ \Vf Iiairc
ajKiiunnl llii> DirliimaT)' nllrnlivly, nnil iire nrnti
hap;iV U' j<ii>aiiiiii<-r II viiiirnllril -il lU (In J. T)l*
MucliimD diinlayed, and ihf eairnorrtinnff inatuitiy
Whi^ti mull JuTP Hrfu •Irmar^il'^rn in ila ^trrparaiuvn
•ed pvTrmifw, tnlnuad ro the Inaiinir cnfll of ||«
aoihor, and liavr rniniah«<d aa wiib a vnliiiii* tK^i.
ffiiuMi ai the prcMRlday. to all who voald Bail
thriiitrlina aa ainaita W1(B lh« hl|livll ilalidnci^ of
Bntiflanafofinnllon— S«*l«iaMbJicaJarf8arri4al
JaamaJ.Don 31, tr^T.

G"od 1«sit4D»aBd EnryH«t|iMlit> wortajcMiprally,
air the uHiat laboi-iBViDK eirnlrii-aiifra whiph Ijie-
fa>r m»n najoyi and ihr tatu'i wl-iirh ia rrqnirnl In

Cnidaoc lh"in in lh« iwrrpci maiinri '4 tkii vxamplv '
ia«aMlhta«app«Illivio«iinlen>plale. Theauthuii

ti>ll« D» in hi* prvfaee Ibal ha baa aM*4 almet i

thiiiiiaail Irinin and aabiT-cta U (hi* HitMia, wbM>
li>fi>>K. wni r-iai<«(!r«d untvenell) a» UieMM v«(f

'■f Ihr kiiiil in ant iaumace.— Aifia

Mar,.-)i,l«*,

lie hai razed htaflnatli' ilnutiaralnlhefOeata-

tiimn, ani (nramlrtlad aad ir*'«att»p|a4 UWJ
pile. N<. tcit th«a rt> IAb»i«ihI aiUiltiiDati
«ijd I* I ma aia 'llailra'Nl and anaivxed ta

*llllyilB, awrJIinf l^r rriinl u.-i-.'.l* ;
aliU* Ilii>iiui4t 'T
■i-*n a r<i<TipfrC^ *■ '
lenntniilifr. wiif.
— iVaaArifi. '
It la iiiiiv

Utll IV>^fk II invir.1l|>llTIII<iy t„;

pTctn Mtdical IjMilMia ia tt.'
The BBiMtit of lahnr wkieb thr >i . di

haa bFal»Hr»l a|uin II •■ iinty w " urn .,<,
lesmiai and rMnieh dianlaT*d in ila prrpafaltii
areMjaalir rfmatkaW^, tviiimet/t and ewn

liv^n M'e anarrr«Hir) , aa B^^ i^a al ihe prvKai day
lliinka af pnrehaaiif a«y iilMr JV eilldMl llKiinarf
than Ihli— 51. L»mU Ht4. mmi 9mrg.Jm*r*^>w^
iMe.

It ia Ike fouadaliiiB airaic ol a f iH«t nmltea] libaa-
ry.and ahonld alwayi hi< ta«|tiil«tl la Iba Aral tmat
bniAa parrtiaanl t>) Ike MMlnl aladeol — ^at
Jtfae(«f»,Jaa IKW.

A very nerfrct writk of the tioi, aaStieb'cdly I
na>i«i f*>lext in ih( RaRlWl laafvafs.— KM
5Br(. Arjiarlif, J^n. ttUH-

lM«n«w*niplialmlly a*MadlMl Dlet|a*Mryl
the Gii|!>rh laaKaaes, aad T'lt it tbarcieeitaeb '
lul>— .V. N ilfid. J*a«*^ Jaa. UMli.

]| laatnio«ly areeaaaiy Mraa>arK that »ay i

oal library waaiiOH a eufi*«rf Daa«lia«'a i^
inuaC he inpeifrcl,— ria. Laatai. Jan lUB

WeHaveaveminakta-real ii itivl>r«ta«ilinrllrl
lulled, and Ifar t>r<*riiled>l"-n <a( may aafrly ■
no enuiil IS IDc W'td. — l'nH**minr 1^4. Jg
Jan. \r6».

Tbe nm«eneiplele«alknrtt* ne ttanh}«CI W fe*
foiiMl in any laaf uafe— f*. tttd. /wwpal, Pf». ^m.

HT TttK aavi atmfoa.

THE PRACTICE OF MEDICINE. A Treatise on SpwiaJ Pathology and TW

rapeiiiiiai. Tbinl KditJM). Ja tTrolarg«ocUiTo TDlmncs,lMlher, ori,SOO|««vi. 96 H. ~

ARU BClEMTiriG PU Bl*lC&T10Ha.

DUNQLtSON (ROBLEYt, M. O.,
Prqftwat i>riM*it«t« «f Mnlirmp in ihr- itftn-M Medical C«ll«|*. PhiladclpkM.

HUMAN PHYSIOLOGY. Bi)jhth ediUoo. Tbc»rou|;bIj revised ud rites.

aively uodlkd u<l enlMr^yst, with tre hiinilreil and ibiny-lwu itluMrattoas. In twa laifv and
kAndMinwIypriBtcdoriavorotanies. leather, oftt<>oallMD|)kg«>^ t1 00.

In reruin^ lki» woffc for jl> riiilnh (ppnarmw. iIm BULhopEia< *par*dao later U raMterlliMr
ReoMiavancvofUia vw^-irvaiCBvuT wUcbba* be«t> vxmxkJ Eu ii t>yih« fTaftttioa. TIm wb
QOalCM* Imw been r««trwigiNl, nnil lu a f[f«Hi «iiirii1 rcmislvlleil ; the invaBlicaljoui which ot ]Ui
fear* h«*re beni mi nuiat^roo* and *n inipiiriaiii, haT« lares otrrfMy rxttaiiwd aul iaiMrpj««twl
Biid thr work in f nprj- rc-prcn bai been brountii up to a !c»el wiih lli* prn^oal «lale of tbe itiilij«(.-|
Tb* uliincC »f Ebr author hjii bc«n lo r«niler il b ootii^iw bail mnpiTtwiiuve trcalu«, oiiatiiiniiii; ifa
whplehadyof phy-iulifK-al >cii;ucr, to which Ihr •ttuJcnl and man of Hcieac« oaa al all ninrt ri'ie
Willi tb« (KTtainly d Aiiding whalcnr ihry arc in warcii of, fully pmviilod in ail its aspcc'U ;
on uu (tKincr editiua bait Ibc aulhar facnlaw«d inorc laliur to xscutc ittu mull.

W«bcll«v«lh«t UeaalralTbvaaJd.aniMiraMna-
pleut rvprjt'ifjr <rr lArta ii£>eiii the Mib^rvt UivU^.
eaaaaywhert twfouDl. TDr aaih'Jiliai,iai>renv«i,
that atviabk l*cl lit <tr»eiit>li>>c ■n>t Uial /■(■iitty
aad rvM oT eipfcMtus wliKb (reder liiio p*«aii>rly

•»M|iabte to th« caiaal, or Ihc »l-l""«a rc«<lrt. „„„^.,„, „,„„,
Thia (arilir. ao twpilMW la »Mtiag f.^h mMy I (^ „ ,„ ,,,' »i,»^._^m«U. /»
fltavei aad Isaa ittraFtivn ■■bforo, Ifm* aiMiUimal
«fearni M <■■■« alwaya faMliiat»«^BaMM JX4
aad &*p(. yraraaf -

na flitM •(waplaM aail aatUfaAMry afaMai al
rhyaM^n' ^ l^ belli* laac>ia<e.— Jntr. af>4
Jtwmal.

Tha bMt wikrk of tb« tlii4 In th« RiclM U
fna(s.— SilltaMK** jD>niaJ,

TbV prf-ccm niliiii>a ihr aiailiriT haa nadn * pcafoci
miitdr of Ui« ■Fi«nc'9 ■■ it U al Uir pn-wal huar*i
Aa a work apoa ifiirwiUtllj pnioar, iha aPMD*>* mt
iherNDCiin«*|wrratnedbTUebndy,lfeealwi)oui arijl
' »f Mt4.

Th«lh« ti««iaee««>lod,nnata4mta)ily aa^mded
la Dla purp'iae, la anpaTval frnm lli« appivraim if
an«i(hlhcdlii<n, II ia af>irllii!(rtat«Ber(ilapodia
iM Iha aohfeet, an4 ivi<f lliy <•( ■ plaaa in »W'f fkj-
titua'aiitntj.-'Wtiurm'LmMai.

BT rU lAKI AQTSOB. M HtV tdtli»i* .]

GENERAL THERAPElITrCS AND MATEllU MKDICA; id«ptod f«r ■

Mvtlic^Test'^ook, Wuh Indite* uf Rvoiedien aad of Dipomw end ihMr Kriardiea. Sutn
Eoirmi, PBria«d aod iaipro(-«d. Wilb on<> hundrMl a<id niiMly-lkrae illuittraliona. Ik I wo laife
Mid hiaadaamvly priuied ortawo vol*., l«<aiLer, oralMjni tllW pag«a. 44 00.

Is aannanolDic a Mw odiUoa of Dr. Daaclla<M't i
6iiBii(al Tnerspmuea aad Uatetla Modica, miiave '
BO wardadf cdmovcadallna tu beatvW ugcm • wwrk
wbtiaa aatrka hawvtma h«<e>itftiraMi onaa aad ■■>
toaily cihilleA. It naat nvt he au(ipa*eil,baw(ycr, ,
thai thn prra'al ia a inrra lapt.nl i>r eJih piavloua
edilliiai (lie elianM!l«t al Um aatiinr (of labojiMU*
TvaaaiaV, jadtpiiiaa analyaia, aad olramaaa nl ra.
priaaina. ia (all) aaalaiunl hv llir uuaii'riiu* aiMl-
tlooa M ilia 'na4( I" H"" tvT>rk , aait in* i^huH'uI ra-
•laioo l» wliicli hi kaa au'i;ciMr>l the whoic. — M. A.

M*Mt*-Ctutr. Ibvuw, Jaa. taM.

Til* Wdrk will, we hira IIUl* doabt. b« >na|tbl
BDi) raail by ttia najocltr of mndieal atuJaala} ita
*iSo. urruit<>m«ol, aiirf Mllabilily T««onawftd it t«
altj an ><a>-. w* irraiura lit praOlel, Will al«4y II'
Wiiliiiat priifii. anit tbcM art (cur Ut wtmui li wdl
ii'M Ii9 111 aiiiij' ini-ttuit uaafal aa a uniik iif irfrr-
rate The rnoaf; ^tu.-lilloii«r,niaMM#t«laiiy. Will
ln4 EliK *i>|iiiiua iiiilfira afifMsdid to Uiia adiam uf
(real luaiaiaaee la Iba aiH<.-eUo«iuid piaiiataliua of
■aiCHbln riirinuht.— C'fcar^ailHa Ifnl. jvana aa^ £«•
*iM*, Jaa. IMU.

Kf na aAHt avtkob. (.i(««w E4in'*ii.)

KEW KKMEDTES, WITU FORMLTLjE FOR THEIR PREPARATION AND
ADMINISTRATION. S«v«a(b vdiiion, wuh «xt«ut«c AdditMia*. In one vary larfe ocibw
TotviM, )««tb«ir, or TTO p«g««. $3 73.

Anolhar adiltan of the " N«w KMncdaca" hacinf beea nlled for, tbe author baa eadeavorvd lo
•dd evcrylhing of munwnt Ihal ba> apprjiird >ii)dn; Ikir jtublK-atiuii of ibo ln»i nliiioii.

The artido* irealMl ot m the Jotowr ediiiiniH will be round to bavc umlfrrrMK nuiuiiicfaMc ax-
fsaaiou ia tbia, in order Uwl UM uuhor m iffhi be f iiabled to iuinidu««-. a- lar ■£ prBci>cah)«, lfa«
i^nlttof Um nilMe^DMii cxparknua of ollior*. aa well a« of hit owu iili<«rvaiii>ti and rellMitMn:
wd lo makfl tbe work >lttl tniuv tteaervinf of tb« «xi«ntle<l fiiviiltii»a with whirk Ib*^ pr«<:edini
edittao* bnve bom favored by the ^irnfeadtoa. By aa enlarxeniKnl of the pagv, Uic numeroiu ftddi-
lioaa hare beeo iopotpofai^d wiihoui f really in<'mMiiig the bulk of the voluuwr.— P™/.«w.

The ■real tcanniigid the mihiir, and hia lenark-

ahlf* induairy LQ raiJiiiix liji Tpa^rvhn inin vv^'y

aiiurrc wliraceinriiiiniiiTit*i>[1c-iii'ah!e,hai'rr«*kIc4

bim U> llir'nv l»ffrilirr an rxlrotir' tMta rif fan'a

feratec, fitr phyaiouia, It « iiiin>rpa«««4'~bir uiy I '"^^ ■»■«''■<»■■.«, apr,a..i.«..r^ l.^ (all ,^lr,r,>er la

' ' ■ „|i fti aaibuiltlca; whiob tart r«Hiir« rcndpr* Hi-? w.nk

0<i«»f tkr miial aac/ul of Uo auliifir'a worka-— '
S#«(A«r« Mittd and Saffual Jaanaal,

Tbia rfaborate asd uatfll Tolailfl ibowM bc
fanad m «rr'V nnllral library, ffir aa a bouh of rc<

•ttetwork in PKiali-ni-r. umI Ilin diiulilc ImIoS fOf
limMMUt ail I Till immliri. will liF fdiiAj graally ta

pTAirliotly r«liial>^r< t^* inwt'.jraliira la-bi* i^^aire Ia
niaiaine lliniirlglnMl pa^ia.— n« AmaruoAa'aanMi
t/ ?luMaw#t.

EULtS (BENJAMIN), M.D.
IHB MEDICAL FOHMULARY: being « CollMtion of PnMriptiona, a«nTdd

flHMB tin wriiiriK* anil practice of na^y oT lh» no tt sminonl ph>'»ieiui>- of Ainerie* uid EurvM.
TnfBllMr with Inc u>iitfl Ui«(«iicPtvpnrBiioni>ai)d AnUduica fo* Pi>ii<oiiib. To which ia •dJc'd
■iH Appendix, on tbe KiidenBjc uneuf MFdi>.'iu«a, itiid on ike axe ufEibcr and CkloruTotoa. Tb*
Vlwie wvompanwd wuli a tewbriefriiarniaiivuiK-njid MediralOlia^rvaliona. RlavRaibrdilioo,
(RnriaMi aad maeb oxiondftd by Kobkxt V- Thomas, H. V., Prolraaor of Afateria Mcdica lO tbe
I Ot)Um§ft of Pbaf acy. ^Prrpitrtag.)

BLANCHARD * LEA'S MBDICAL

EAICHBCN (40HN).
Pfffenor of Ssrcrr^ In UalvvrtilT OUf ti Lon4at, 4l.

THE SCIENCK A^ii) AST OF SURGEBY; beiko a TasAnss oa Snoic

Ix.n->ii:i>. UinxJiAKB, AND (>i>kraTIOKB. New BAd tiui^irarrd Am^rimit, frnm tbe •oaoMl n
andoaceruDy rc^'i*ril IxAdon ediiion. Illu*iraieJ wiib ovrr Tour biMd««d vi^iwliif* 4mi

Ill our Urae *nd hnndx-'-mi' o<^bva Totime, of oat IhfMiwfMl cimtily pHfttnl pofv*, Icalkar/

raiffA iMn^K. t1 3D. iJmtt J»rntd.)

Thf %-cn'^i"'<<>!i<>-)»'^ rai-orwiih which thhwttrit bmn (m^-d rrntvrd m bc<)i ndvxorika At!
tie h(i» i>i;R)ij1alPiI if* •uiKor lo rmiMi >l p»»o mor* wurthy of lh« nwitkift whi'^h tt kss »o r«f!
ailan't-il a* a ■l«ni)aii» vMlin
haw titvn maHe, uid thr tnml watcUiit carr ba* brrit vxcrciH-il (o rrnilHr tt a ru(ii[<If ■(• Pijwni
iifihx ni>»i fli}Tiiii(^ coniF;tiuii cif'iiiripi'al >r:rnn^. In thi^ inuinrr \he work ha* 'avn f-niait,***!!
aViul B hiinilrei) pag**"! wNik rlir rf rir> o(' r^rravillK^ ha* Erni rnmaxsl bf marc 'han a fiuonh
rmilcrmit it mie of fhc m<f*l ihnrmijhly illimlratri) voldnir* fTforr ibp prolFMtiM. Thr adili'
Ihr Biiiliiir hai-iiif iviid^red unflMe^an nuiat of Ihr nolr* ■■( ih<- rnrturr Ani«-riran rdttur,
has been added ni itiis cnunlry ; Mime Jitw noteA anil uvraaioAal illik>i(ai>e«>a bavc.
Introduced lo elucidate Ansriciui tnodoe ot pnieUre.

Ilia, I* tmt humbln )uitainFni deci-diiillf ih* b«i map ofih'npvnlMHi.antf MIttwKtaif hkn aaifll
tMok«(lfcD mad IB Ihfl KinfJitli lni>aiifl«r. Siranm i filial ixnc of Ihe rucH ilerldrd
tHai Jual «arli tmoki arr ixiiDrtpriri |iiuilui>»il !>> |>uti-
[>e l(uehf-r« of lUicrry in ^lii> (n^Dnlry anit (ircal
Bfiialii Iiiilr'd, I' U ■ miiL'-r nfitivnt luuiHltltiiK'iii
bill na Lrv« irur Ibfen n>^oiii*liJac- t^at of ^hr m
nnrkiisii >iitar'} ti-iiuMohril m ifeKpau'iliy n'.i
itar 1»>1 (iHt-ii oi laTtuty yrart «■ i/-ii-IinAlii> ■■ llii^ oi-U vtv ikul avrii »i>-
prniiiriairii ici Ikf fuliilairnl anf>e {ici-uliat waiil* of

(M vatac t( ifTcarly cnham-Fd tiy a (er) rap4ou>
wieU'arranccdi'i(I''X. Wr tfgtfiS thl« at one of ibe

aial valiiaMc roaUrilJiil^itm I* uiiiJrrii aittiff ry To
e fiit«ni>« Ml hrtriitai'^ iif (i'"Mii>*. w faaiif >' . , .

tbe IBB<1»-Trirealiir iuhIb ialiii.'lil>i>''iumii>iall Mr • tor InfermaiiatiiHlih la pbir«iriar B>d ■utv*mi, IM
will liuAafalaciuadilelaillcadiHvbiin throLthcTcry ' homi ol pcrU ■— It. 0, Mm, w^ Otrt. Jmrwai.

Kai1>rB<rmf . u inllkp prFrtitHl.ia* ^haU «1
cal d-:-ina<n. aM ra<b itiv»tau oT iuclf alaMMj ■

"' r.i\iirifiKt.f '■>•■'-"'"'-" -■'■' - ■ -

iiilt>fallv<ll'
■i of it m if ■- ■
I . - ... Ill rn1tr'^ulnr , », -■_ .1.-1 , ,1- |. ■r-...-.ii
t>ri ainirlF laFuim bow vaiBiii nn ika •■hjairi.
w>ih rr'81 rl'ai'ni* wf arid il la ow la3i'6aafek-

ywii. Krici»t«n'i wMk. (at iia bun, ii^ aat '
>urt)i>t«li Ilia aitw bandrvil aixl ngtil pa
Oixiy illir'irH'rd. are nek in ahr«M>loff)«al Tm'

Ifctl, anil o|>«rBii«F •■nrMioiu, do-'WiBBikii
•nil prf»-c«"*) and wiirprorc a tcltablp nf

FLINT (AUSTIN), M. O.,
Pfoftaaoff rtf Theory and l*ra«li«*> nf M«li»in* in iIif Uaiwraltj of LntfT'IIIc, A«,

PHY8I0AL EXPLORATION AND DIAGXOSIS OP DI8EASKS AFFECT-

INVi THE RESPIKATUKY OKGANd. la one lar|e and tMUKUone uclaro votuaw, uu
cloik, 038 |»f m. » CtH.

W«-»waTd It, in puinl hxili afitrarwaniMt and at f A work iWnriatBalnlaarTatiiMnf lfr«|»l|r>MM|
Ihr mvtlire alHlili ••( 11* tiialiapnl «r the aahlTcta, We rrroiiiRirBii thnt/ntltir lorrrty mtr w^}
a* tfrtiiNrd lo takp thF KiX (ink in imilia ••< (hi* | tn iiii)^r>nf ■ r-iittttt laiwaltal'-r Bntcil in |
ctiu* B" far ■■ out mfiiriiinliiin riirailt.tl kna at la'** aitRit Dm>B raci cninTi'-Bll) *iiihi1
prvitlt ■•> r<|Bal. T» l>ir 0niriiiii>o»(, at urpll a* | rariipa IheprMclMVOf *ar*faP *ta4t aail «iwr
Ue aladfiit. il will he iaialaaMn in rlrnrin^ n|i thir imik bK>b PTPif fB«« It il>tf> rif^ii in ih*
dlnfW^al* i>f douMfnl naaea. nn<I IB ■li«d'<iBf Ugbt ' aad. ihtnvfbkiiB, lethc ri-^f-M»tnn la ilitt 1
opoB diAe*llpkeBoa**Ba.~ili</«ta Mtd. Jnttmiil, I It ia, whai w« ratmni call rvif lumfe apnitaaa

I tauoo, ■ raardafela kaok^Am. Jamt. M**- Sti

»Y TMI RAMI AtTTHOl. (fV^w Btaiif.}

A PRACTICAL TREATiyE ON TilE PIAONOSJS, PATHOLOOT, AN!

TSKATMKNT OF DISEASES Oi' THE BEART.
OOD pa^«. eiira clclh. 9i 72.

Wadi> an* ko«w thuiTIr, Flini hBa wrilirn bht-
IbitJIT wkirh la nut fiFilrati ; tiallliW, hia laltttt'Vil-
irihnitim t>i lardif-Bi liiriatuia. ka oui ••fiiuiita, aDr>
paaaM all Xht cIliFta, Tlie wmk lanioat c< 'BipltlirB-
alvpiii iia ai-ii|ir,unit Kixal anuiiil in tlir virn-a iimua-
eiatia. Tlir iIcMiifTtiiiaiBrf f Itat anil mdhodiful;
thr •is'irinpiiia nr* mt^alanllatfd t>y facia, anil arp
■Mde Willi ai.vli aiuiiilieity nnd ainaority, Ibat witb

la oDfl n«ai oetttro roktmn, ot

tT<«t rn>«aaadkaautT,a»4,wMah
ftUpCB him at Uk heal tif AKrn
^taanaaa of Ika ettau. Wb iiav* 1
upoB tk« b«Brt ■• B t'al.lHiiik, I>rljcric4 Li |
raiiravalBablft U<r t\*t puip'«t thaa mty w-tkl
kiodlhathaavrlBi'prnrnl— A'ajAr^JIi M»4 ~
With inotc IliBn ptHanrr <lo vf kail iha sijiPrkl 1

iklt wwK, for it illaa wvltca^uB tlaclMtii

Mil Itirm U.fy wimW BB.ty F<««tcilua Th. alylv | b^.^, ^„, '^, ^fc„|^ ™i j,, ,„ ,4, p«,dl».«f«,

S-!rL'^"v.' ^l".' "„■ V " i'^ rifvara. ii,«H,oalTBl«aWap(««uaalw««kof iukl»4— .T.O

With Dl. Walabf'I*Jl«ll»Bl Itaaiiap (ipfniai m, we | jg^j JVtw§.

ba«r BO bnaiialiiiD in aayiait llial Di- Pliitl'a lii>i<li ia j

the bnt wi»k ua tbe beatl ib ihr Engliali laugBafe. , h t»nH la the fBerlta of the wort, wa kaT<

—ttoilam Utd. BBd Smif. Jettmat. krai<Bli>io in priwnaacinK it fall, aimrain, aal Ja

WahavalDaiaBdraroftd to^aaral o«r raadera '•i«'*"» C«i»MhTin( thr pira-ai ataiP nf 1
Willi ■ /ail aualiBia 1,1 llili t*ninrkal>tr iiriwk. Pi». 1 »"<■« a wiw k waa Mb«4i BM(l<<d It akiBlJl «
r»ffi««i..»-ai|.loy the very woidBofOKdiaidguiabtd ''•■''•''' '*"TP™<*""»'"—C*«*«» "'d /•
Bnllxii. wli*rr«t'i it wa* poaaihlr, tro liar* aaaiiypd Bat Itanap ar^ vrrr Irlvlal afin4a, and
10 o"B<ltn»e IbIo INe bfirfcit ■(lacfaxtDciali-iewof ptfv-ni aa from drrUna* mr laaai hiailTaf
hia olueivaiinna ami tufgrtiumt. luiil lu dirpri lb* . of ibi> nnllnM'a abilMy, inilBalrj.aBa ma
all<«li'« r>r r-uf l>rflkr<ii t'> lb« ll^oUll>)lna ati'te* (rf Beat.— ITmMm Qmmrlitlr Jtmnt*! 1

T!!'?.^''!!"!""'. *""",■?'''";'"",' ri'"'''^'!^.""'" npbaalaboraitoawl.klb-»i«.

ut» toti iBflriidKin. N'> mulit-B' lilitaiv will li'in
afler tx? pc-na»<'tn( aninplrra wiihuai ibia *i>lDni«;
BBd W< Chi* Il will pi'-mpily IVnl iia way latn thr
haada •>4 rvaiT * uw- ma aiadaal and pbyaieUa —
A Jm. itarf.llir. Kfauw.

Thia hat wmk nf Prt.f ntnt Brill aid mnrb In
AU fttviiniB WtLl-«uMil c«lt\iiii^, aa a wiUat l4

aad hi« place ■iBi'kBt tbr jt'itu..*'.

laliac'MDiBf fall}^ raiayiJi- 1

Wbi>*eUllf lacirm nb-iTr

flp^rpa Ou' •!« ■• wih ni'

aaalyai*. mid Wr Will rl'in Inn <ir-i,' Bt.'irr h^j

(■■■nirnniitlaR 11 ic-it>i'int rravr** in aTVTV tlaia 'f ]

TcadBraiiiDicpiuiaaiuA.->Lfa«aaaIar JBaid. J*

AMU KOtrHTCFIC PUBLlC&TtOMB.

rowNcs (QconoEi, ph. D., &.c.
A MANUAL OP KLEMKN'TAUY CHK^lISTlty ; Thcorch'ral »tid I*nictic*I.
FnMD ibvwraoib wviiedMid wmwicd tj'>in)"ii cOitit^n. Wiib one hinxlird iiid nini-ty-twiti
illuMruioB*. Bdlied by Romut Blioni*. M. P. In on« Iwr^* royki IXiko. valun«,' of UOD
pagtw. In leaiber, 41 e5; «xirs eluih, (1 M. (/«>> /umu^.)

Tlie4t«t(i of IIm Ballidr lisvinit plnuid Ihecrfil'irMl cure of Ihia worJc iti th« pracliHid baod* o4
Dr>> B<nl■^e ]i)fie<>uM) A. W. Hu4fi«a<t, ifvrryiKw^ IM* bcrn dune la il« fovisuftn which experitmoe
roold ■ti^fCMl lo kfr-pii (-Da level wiib the rapid miwattoo oC ebemMMi n-ieatv. The wldilKmi
reiftiblle lo Ibi* purj^pc h*re H«c«iirir«ted u> enuufeownt of tli« p«ge, ftu(«rtrti>.[Midii>g wbirli lAe
wwk baa been Incrv&Md by about llllv \)tijt«t. At lb« Mitie une orery miw baa hmm immI M
malntaiailc^iMineliw chnmclvr a> a (n:''>Ji>iihkI manual Tur ili<,' •tiMlc'i)l,'tJTv«(adof all iiiinnriTanf
dmil or mere tlM!nrriiciil opcv'iilaii'in. Tlic uddi'i'ia* hare. o( cotmc, boca mainly in thfl 4ap*r|-
tii«Dl (if Orfmnk' CliFiiiiMry, vrbjuh ha« iidailp mi'b rajiiil pruereia trilbiii llie Itiai Tew yo«r«, but
yei^-jiial »H*citiua hatbsM beatuanrdun ib* nrljpr lwanckee<if ibo mSjw*— Cljwiiwal rii>»Maand
InnrRaDic ClwiiiUiry — lo pnwwwl nil invf»ii(taiii:-n« antt >li><viv(<fir» of iliipiirianc«, and lu Veep Up
tbt! KpMUUiom oflba voJoinc a> a ciimpinic Huuiiuil ofibe whulajBBicnnt, aJniimy y ailapieti Uir tha
learner. By tbeuaaoTaainaUlturi-K'vadiiuIy clear irpB lbs mailer of ataqtr (icMavoiieiHnprc>MrJ
wifhtn llie I'txiventrnt ajid piutabla limila ufa luuderale Maeit dinjHrviinu, and at ibe very luw iMiue
•Axfd, II ia oBctvd a* oiic of Ibo cbeajKal vulutoca beibre Uk prvfcasioo.

I>r ^'"wa«a'e*l^fllPlH wr* haa r.eea uoiaarHlly I Tha worl ftf it*. FawM* baa lo>aa baw bafan
tri-i>cii.x(il cvrr] wlirir- in hi* owe aail tl>i> riiaatry. I tkapoMJc. aad Ita aacila liara bam hUj afivaai-
«i ur t.f«t cIciQtnuo' i>caii*« □« ehemmiry la tha ] atad aa ua baai laai-baak on abMlttnr dvw t>
EaaUA toufDfl.aDil !■ v")' ttxnrtnllr ■ilufiml. w" : aiUicdea. Wsitn aiil, iif owrae, placp il In a rank
Miata.aatbaHaaiiaTairxl linithks«Il'ai('i>tlr(oa, ' iiitiorior to tbf wr'iKanf Brandt, Of ahatn, TnnMt,

■irrfiHT. nr Ginrlia, Sal we lay ihal, aa a i*i>T%
for iiuiMiiai il la iM<(BratiU U) aay of tbitm.^L**-
dem JsanMJ •/ iWiAcIu.

A vnrk wall ailaptcd lo tba iraBti af iHcataaeal

Il ia an excrlleatrxpuiiliiiii at ttiP <hiW diicKian

iicilf*('ii'-rni»iiw»<iltc'ini*crv. TiKiUof Uc vrvrk,

uiil iIlII nciie th« i?nnil«nmt feX pani|<ir'iiiiii alflc

<afflBBtlfiklar|C»era).— FircHM'aiCtd.iiaulSHriiicaJ io whu^h ll ia wiitlm, abaolvc iirrom (kceharfea

Jawntal. j vi^ty pn<|ii>rly u(t*it agalnal ninil mnnaoli i«rised

I piipBlar.— gil<at»»fi Jemfnol </ Mfi'i'al S<i**c*.

KDwaann'iaaaif.Jt-D .orEdanlrjo N.C. T»-

artliei lo iNie nail ^u v<ilain<i,rjitta(ili>lti. 81 00.

FBICK (JN RKNALAf Kf:<^TU)Xl*i l^icif Diag-

[■•••li nail ruttiiijiqty. Wilh illtutnttxaa. Una

voliim«.r<iTilMina..utrac)<xii. ?»«aaca.

totb IfuraraMutaotatlifc — nia>l(iim jHiit Jvmn.
Md ««■(*«.

A atanilBRt n«a«l, wtlR'^ bai Innir enjnynl Hic
re|HitBt|(>n nfombodytnir nnrli Vnnvrtr^lt' in a <ni*II
•paea. Thr aathDihamBrkirTaa Uipdiflkciilt ta«k iii

awiJanauiiB with aaatarly Ufi. ll>Bb'«<k i*<'>n-
clM withnut balafi dry, ind brlBfuiiiIi'iut tji'iiiR i»

FISKK Pl'MD PRIJtK KWAVS - THK EP-

Dl!fK\*H. IIi-KowiN Lll.M.R C S .LiMKlim.

■niTiD' iNi'iA'KNci:i.r miir.wscy HN

FEAQUSSON (WILLIAM), F. R. ».,

PfrifxMor atf 19B((nry In Kma'« CiHIrao, t-naiNia, fta.

A SYSTKM OP FRAOTIOAL SCfHGERY. FourtU Aui<.ri.-»a. from tbo tbW

cud enlarvRd l^onaliin ediliMi. [n n»« Inrm ami t>riitri(u[iy prialod uoUro waluiaet*! ikftil TOQ
pi^ea, mtli 319 bamhoffle IHo*iraiioDii, Icmtinf. K 00.

QAAHAM (THOMAS), F. R.S.
THE ELEMENTS OF INORtiA.VIC CUKMISTUY, iiMlading tbe Appliot-

li.m* ntKH-Sricntcm tbi' Aria, Naur anJiniirh riilarfrcctrdili.'n, hvHKNItV Warm and Romrt
IlEitn.nJi, M. U- CuiiipJirte m one larf^ and hand«An)(? (u;1avi< vdiimc, ol nrer BOO very targe
pw;(». wild two butidrolarMllhirtv-tWo Wuod-CUl*. nxTrn rlutS $-100

1*^ Pari ll.ooaipirlinK ihe Vurlr fraoi p. 4.'ll In end, wtib Ittilejc Tilb> Mailer, Aco.. nay be
kmA Mpamtc, otulh Imc4(* and papor M^ea. Price SV 30.

F*fm F'tf. A"- W. Mrtr/*'*. t{afr*ft CotUg*. «ff"fcl in he wiilwiat Uiia edttlna ff Pfof. Qrahani'l

Il h»a, -M ilacai Uor urd Iraa ttcrfMli'ibliMia, bivs
(^liarlK iBf^iiiad Ihr rirvllrnra i.r (u pina aail
Cho (laaiMiu aud RiMnrdHnitaa af il* dMaaaaiMU,
b«*e luaf liaaa ny admirntina.

Illniii-nta— Sillimaa't Jaanul, Matvh, ladB.
fVan Pro/' nr*;eaii Oiii,,, N- T. Ft%t Aimdtmf.

Theworiit •nidnHraMeaftt tnallraapacla.aad
Ita rvpalillmli-in hern vanaul fall In csftI apinlllve
No tasdafar Eof liili wuTkt on tliia icieriEe can taIlicacc.'CB|K>BUcpt(itrttataraetMeaialtalaff«MBny.

GRIFFITH (ROBERT C). M- D., &o.
A mnVEKS AL FOKW ULAKY. eouuiuiug tho methods of Propirinp and Ad-

ininiatcriny UlEcinal O^d Other Mnlioino* . Tb« whole adaplBd lo PhyKiinanH ftnd I'tiarmafvu.
Uala. SkooiiD EdiTioN, Iboruujihly rcviaed. wnJi aumerouF addilMm^ by Kobist V. Tuumas,
M. 0., Profbaaor ol Muteria Meilica in itm Pliilndvtpbiu ColliMn; arPhartaary. In one lBrr<^ anil
lia«d*cinieocUToT(>I«rDe. cxtt«fltiHh,oi'W> paj(*i., double cot nmna. C3 00; or in »h«'<p. V'i^.

Thi* i> a iruit of an bundled and fil^y i»ic (iDXca,

■ni'itamin alt iin lb.- -udim ofprrpBriii anil ndinl-
uufima iiH-rtiririrtlbiit can be di^tftJ |.y Id* rhr*!-
*iaii and p)>arTuii.-i;iHiM. — Walm» LancM

li «a« M aroik rrquiiin({ riiurh jicrt^Viriancc. anal
wlfn [Hjlpliihrd w»- limknJ iii>nii •• hv fai ih' 'ie»'
wort af »■ kinil itiM *>"'! i<*u-'l Crnm III" Amafiraiv
prea. Frof TliD«ia> 'lai ■■'tWitaty ■■iiuiwo»c<l.'' m
wall B« addf^l loUiu Fonmi'n-i. and hu> r^«*-.-J " xii^ «moun.«fata>W,"pry-dav «i«ii*i.fcr a nrae-

We arr l.a|.p> U> aan(Mnr« a aaw and iapravf d ! tt,„ oj„,„„ ^^ j,^ rraail» Iwiwawd by Ibe r«-
9d.i»n ai ihF OU0 uf U« tiMiu vat<.ar>l> aad ua»rul „„„„ ,,^ „pi, .^lim,,,, ,(■ d, 'm^^ „„i „
work, ifcaikavr "io«i.ai«l rruto «i AiKoriMB pti.. i^ow, wa b«IMt«. ottc flf Ita mail c*n<|>U>ic warta
Il wnatd an cr«l, a.,, .■■wil/j. aod wl 1 br round | ,f ,„ ^,^ ,, ^ U.-Ka**' Th» addiirn.. anDoal
«f .lail)t uwifulort- iai..a<lihi«itr. of miJifia*. .t •« | »tt»al»e«niT»ar-. nii4 a^rCon ha- breti*|Mred
6-«-« «4iipl«l in ik.if ivir|««. ^bHii .ko d>H»»MU> I ,„ ,„p,^, ,a ,h„n .i! i^, r<'*»i laij.ro.am.iiu A
tlea -JUwrf.™ M.J, a>tJ Jiui* JatiniU. „„„ ^^ li,,, j,,,^ i»f if* 10 •• ii>4.ivrn-al.lf tn Ike

III* no* of III' nui>i imriui hr-nk* a ■■'>anilT praett- 1 phfaiCiBii. Bint th'fr m ii<>iti- or iio imi-r' rani i ally
iMuar caa IMMLlily tere.— JKntattJ C*raaMi. 'laeaaacad. H V Jtmnt^ltf ««rfia»m.

BLANOHARP ft U¥a

blUAU

OAOSfl (SAMUeL 0.), M. D..
Profcaanrof Sartor r i" t**" J''^'*"!! Mrrilral C'Atef^irf FliilMlerpkM, t«,
SnUig*<l BdiUon — Vow ^Mdj, Jmmuj, IMS.
|a 8YSTBM OP ST'Ri^.KRY : P»lholt>gic«l, Wognontjc, TtK-npratie, kd4 Optrv

rive lllOFimied hy T>vw.rt Il»tsri»ri> *•»» TwMTV-sr%»it R-rcttmna ScpmuI t^kh.

lfHicb«iiUfg«d»">f '■•"■'■'ly '""■*^- InlWftlarBe MilbMUMirBliT l*i»l*d rtrt»wi v _.

kiMM lw««iy'C«ro liondrt-d [AgT* ; Btroa^ly bauitrf in Inthcr. Wilh rmi*«d twntU. frrv fn

The rth«nii.on la litil* m""" thfin iwe yr*t* of « largv rrfitiOB »( m eli'
liw ■ wuik k* th« i« Ibe bff-' ••'ritf«ri«'» thkl llw mtnhor ••• nnf tntiiafci-n :
w»rn w!iich(Kt'(>.'<lof a '■•^i ' ' '"■*" i^V'i'm of ^

nMvtMitr tl.-'»i!n fen.) in "11 ' Th»i b^ h»««i-

i-»hown'n'il iMfy by i(k.' ruf ! i •- w.irii, but «!«o i

bn* f"W« leoeiTCd by tl>« "rnotiit .J tbe prnfim^ioo tn ilii* cuwiLry aiij i» I^..
« truii-lxn'm i* now [iri-faTinir in Iluliani)— ■ nritik of njiprcvwiliua nui ctirn -t

TM •uihor !«• ni.i Itt.-i niM^pjl '" ">* klodoc** Ihii.i hrMowtd ■pon Ma >»N
IlK wurk for * n«w cdiiion he haik ipariM nn patnit lo render II wonhf trf ihu fii
baa li^rii rorvivrd T^vrrr |iiirtif>n hai ^f^n 'ul^^^i'Vd M cl(>*9 rxwainBtim Mid rvTi<:iCi, ui •*.(
cjpncw* ippiin'iit havr tr^n rii[>;Wicil, »iid ttir rrtiilti of r«c«nl procr*** M iW irl»»r> mdtnM
MiTffty h»yvhi'aptrtyvht'c iniTrMtn™-/! ; white ihe K«T>t4 "f illu-i^-i.'— - i>— ■ ha^m tmkn't "
thr nddilEOft .rf HfBfiV lii'f r hunitfrd w»f J-CUI*, ii-»\«Vf»n^ it <><»• i>r iV ''»«<9U]r Itm^pn

worfc-tVorlrfdbdi-TC ibc pmfofioo T" •cciimirf 'tfr- ih^-pn-fy. , lillliaai, ite •■'I

kM b«fn |irinl*^lopun k^niallwf lype. k> ll-al oo-w.il - v^r^ lurj;?- UKrrajv [a(bat;w

■■d valitn ol ih« bmik, iln •!»» i* nioHj ri>ovcni«>l m imin ilian tvdifc. E<*T ™i«aw

bnen takiEB IB the pi'intinic lo rriuh^i iba iYpi.i4(B|.>!j.. . '..■'. j>ion Di>«>ic*-p>Hai>b'o, and <t ■(!■(
ilenily prsM^ntnl as b work in evcty way Wurlby of « fimaa m xtm Ito bmI linilaJ liteaay rf tk
praoiiinaer or alndvul.

A few l«MinK»iala rf the »aW oflfce fonwr coition are uiipraiiiFd

ffatDr nriaa«ali«fBCtorilyfatlill(4 Ikia nliK*! • ; Of I)r. O'o»«'» ir»tla« na Safarr «• m Mf
A eatf rul peiatnl nf Ma Wlaw't eauWea ■» I" HIT" I •" i^'«

anniiaMvi 1b thcnffiftiiiuve. Nul ixitj fc«> li"(irn»
lA tr>« rMd«r an eUoTTUt *»il wvli-wiittMi ■'-ir-'ant
*r hit II «b tatt vKpM ii^nci*, tiul liF hm tn^X failed to
rmbiiily in ^ii4 pofr* I'lr op Ei"ni an'I prartlcr •>(
aui<»'>ii» in t 111 » mill I'llirn". uritilr«of Knfijv*. Tlir
fcanli haa tirTii a wnrk of iticli oompl'maaa.that il
haa H'l *ii>m(>r lu ll"- ■]ri((iiia:iP lrrati>» nm aur-
|[*r> whirh have emanatpd from Eejliah or CoBlt-
nrntil laalhin ll h-ti h**i> Jiiiily nbhrrtol Ihal
Ibtae Imvr hiYii (uf ri>'inci>ini>lFlc IK itiaBV raarBlixl
I«ri|i:»iliit», m»iiit nf Itrriu hirlria Ivroo drftcifBi ii^
ai>ni« "f Un nioal miiiorlant pi>iBta wlii:h an<.>nl']
el«alaelarixea'i<>ti W'i'i ^>>■lll' ••( ihnin Suve k«ra
eliilHirni'^-l>"' rl"l<"islr— wiih ittfrtl tu ctrtaia

-^lara^ra, VPhtIr 1)1*7 tia** mrr*!)' itUarcd at, 01
MiFrn B> untniiarartriiy acMiunl cif, othrra cqaally

1 H|M>r(nal lu in* anrnMiD. D> Grot* kat avnulril
thUrrrot, anrf hiiacirii4ijrri1 (he rriinal mmplets WnrK
thai '■■a yrl Itav'u fn-™ the piv«iin iba a(i*e4>eBB<l

Eraclio of auriprf- II 1* ai^t, ilrlrlly ■pmktnf, a
'ioid'aary oIPu'bpTi *"" '' I"" lo IH»^ wntfar all
llielafiirinaltdD criat lir may irquiic f"! tin limliiKiit
iiranrpciral dtr'itri lUvknn tiiiJ •>' mitch, |l mijlil
njitipai lujiriflit'iua to ailil Bii(<lliri tr<>rd ; bitl il 1*
iinly^ar toDi Grnia t« aui* Ibai bt haa ambne^tf
Ibn >i|>j>i>rtiiDklf ct traniirirmv lo his p>gr« a Viat
•unbMOl cngrariDica ti'tm huitlii* akd vUtar av-
in<iT<, illu*ii*ilva<-i the |ia!bvl<^raailu<*tawat or
■niricaldtauiKt. Tu IhtMare ailitJ aeTeral hBB-
ar«ili>n|tlnal ur-i'iil-viita' Tliii wiitk altnjfpihai eitm-
nirnitt tt*cir to llie allcntioD uf Diilitli naicM'ai,
floin VrholQ il aaaocl fail in nitaiwilh axtauiiva
paliiioago.— /.•■dan Lamttl, &tfl. 1, IhiXt.

' tl:an inal It la llin aaixl alakxii
ptrlr n>if k na Ihia hraacM iif lk< b^ii
bun VT^i hp«B nnlilialip^ >« ■'af i»-
iFTiuilir «'-<[ll. It adn ii> --r lu' aaatir.

ii'innrnlfarii friiiB 'ur t<««r)aaiM(«

iif lltr fiaattPnlatf I- . " >r . «a<l taa tUU*-

lag way in whii^li carti nlajirt la ltaa»»A >y*a
l^>iFi(r;|i /aVT«aj »/ JSt4. 5r(n*«w.

Tl>e wi^rt la an aarsttnt la (U pr^m^aaitt
niallFi anil ailaBl, im «*«II aa m UhaamrlaB**#
(t|ln <•( pahlkalli'iB, thai ara oaa b<»«atlf ■—»
mFad (I aa iba beal mrk u^ Ike ttpl (*(■*»«
faixnahr >h«yi>«ax p(aolilin*ai.— Jm. IM A«a

Wilk flaaaara w* rivurri Ika romfipt^m M Iba
liwHiauataated vrotk. Tbe rnnaialiiri -mIM^-
aallutr baa fni naait yiiara aaaCaix^. Wlk aai«a>

faniD a>d aa a wfitet, ba4 |>i*MtW aa •■ ii^ai a
KBliaF "fpcr'ai irxr*ltrtivr aait •■n^iaBttt'T , tut**
nwifraa wp trrir hy a«i ims* ptw^rmC fcx tkm «•*
wktrk labpforr uv— ih* ai»it i-<m>p4ata tM
aDT(«rf e(er patilli^rJ. rillirf la thta i-r
coaatry, aad mt nlfhl, firrhapa, aa/atr
nanal orifiaBt. TVririaBo aahfcri taHan

Hirtlyi* najrwy wtith bai bh i«ecir«4
BDtliiM a daa a*MC ol altr-BUaa. Ifa . On«alae

nliaj a wiM in avifeal lita««MT* wkt^A

bM« fall tif jirnrlllKiBrrB; h* haa fhralilv
a ec«nrl«lt praMioal itraiMa a|»B aaagaari
diyatlnrnu Aa /i flptue ma, <vw ■» pn
Hcliict-rmmti aa aurfmiaa, tr* arc Maal
I^Biiiral In liini ("r Ilia fixn«>ml Barr kal'
hrumU —A. f. MtmUklf Raadna am4 B

BT TBI M*m 'DTKOB.

ELEMENTS OF PATHOLOGICAL ANATOMY. ThFiJ •aidoo,

reviled and ^iratly improved. In iire laif c anil vrry handaoMiooetaTu VoIinbc, Vilh 1
hundred anil llfiy •■cinilHitl iliixtruii.Mn, of which a large nnffiter are tran arifiBal
Price in extra Hoih, 54 7^; Iraihrr. r»iM-d b«nil«, f5 W. {l^tUlf PiiAHtktd.)
The v«ry rapid ndvaiieea m ll>e SoieivL-e t-f Patliologimi Ansiomy ilurinc ilir laai fr* yvasa
reaikred eMPUiial a iboruuh KioJi6raik>i> of ihia work, wiih a rirw of niakioy ti • mrraaa
neni of ItiB pre-MiBi Millie or the aubjefi. The vary carvfnl manner In which tbia t*«k hm
vieFUcatl, ttnd Ihe aitinunl of BllcmiiiHi which it baa na^rgoBe, hare enaUod Urn «MkiM' l« a^ t
- with the n>aiiy ihanfei and impromBMii* now uilrpJueaJ, ihv work Biay be ragBJ'^J ihawl
a nvw trPBliM,'' while the rlluria uf ibe BUlhur have bncB MCobiM ■• f«||»Nla lbs MBlfei
eseniiiuaof lb« mlume, render in; iloaoof ibe bajidaniBeat pfoduetioBi aT ibe ASB/iMB fM
W« moil •tB«eTelTcnnitni|gla(Blh«aBlltor«B the Wa baye bee* faataMj iiai| 1 MiawWhiW.
■aeaaaaTut (naBBM in wlHK'h bakaaapenoipllahadhia tal manorr la wktob Pr Qroaa baa fiaralad kaa
pra^itet obfeet. Ill* bwik la noat ailntlratily cal- ' of ■f'^nfiac a enAprabrwrfvr <Ur««> *^ W

ealateil tn Kit op a iilaab which haatoiif hecnfalt le

•Bial la Ikia d«f«nin*Bl of medical hieMta ra, aBd
aaaaehHaat kaniBM very widely eireakaiBil bmomkbi
atl ilaiaaa ol the prDf«aal<iB. — i>aUia Otiarliriv
/aara. «f Ui4. StH»€:Naw. lSt7.

atiie nf iha litFtatatfiof hlliotfnftral kmali^J,
hSTB math pteaanre ia ravoNnaaBriM awwank '
mr reader*, aa w* hdlav* awe «r>B 4
ditiftnt pcraaal and earafBl BMdj'

BT -rns savx armox.

i PHACnOAL TREATISE ON I'OKEION BOMBB IN THJB AlltPi

AHD BCrENTtPin FU Bbtn ATIOHB..

QFVOSS (SAMUeL D.), M. D.,
rti>f«HO( of flaifi^n' '• fie JiSrt»'-& ME<]ic«l Cull«(fl (■( PbiUJclpkla. An.

A PRACTICAL TREATISK ON THK DI8KA8KS. INJtmiES, AND

MALFORMATIONS OF THE I'RINAKV BLADDER. THE PROSTATE GLAND, AND
Till! f TRBTHRA. 8(n-<iiiiI Eitition, r«vi*vJ ani) miwh «nlar^il, with mm hiin<!rp(l aiiil fightj*
four iIlni>ir>Iiiios In niir> biY^ tnil vorr hanil>oiii* ocUvo volunic, of ov«r nine bundnJ P*S**>
I> lealbpr. rniM^ Inuk)*, 95 2.'*: enrrm rtolh, t4 ?.'■.
nUni-iphtMl in li de«l(n, mrtliiHlieul in iu at- ' a^rMwIUi oa, Ikut tl^ere Jinn work In ike RacIUh

fBOIF'oivntiiinif^tH Hiirl •mi ml tn lla pmctirftl i1*e:ijI*,
U HMTtl) trulli tie Hid lo leavr icnrrrlir anyihin* to
bv <l««ii*>rl on ■■■ impiircaat ■ «ubjc«i. — S«i|«h Jftrf
Mirf S«t( jAUrmat

Whcwvar will pcruaa Ilia niat ■nimnl ii/«alDahli
pneucal utTiimBtiuB il eonUiu*, will, we IhiDh,

ianruaair wlili-h ran inika my jiiai iKrianaiOB* IV
be Itarrjiml, — JV. y. JairraiSJ tftS'ditimt.

A voluina xptnir wiUi Hath* an<l piini-inliiaof tka
iirnoit raloEln thflDVfaonUanofthcaaditMJM.^
immri€»it tttdUat Jrumal ,

QRAY (H6NRY), F. R. »..
LeeinKT iTR Analnmy «i .*t. 0<-"rg«'(il"apital,Lrf>itdt>B, A«.

ANATOMY, PEaCKll'TIVE AND SUKGrCAL. Tho Drnwingii by H. V.-

CA»r*m, M, 1). ,lB<e IVmonrtnilof on Anatomf mSi. lieorfc't Ho>plUl: Ifit- Di»«<«i»nt jointly J
by Ibe Arrnom ami Di. Camtkr. StiCMMil Ami^riran. from the f<mii<l rcriml imH im)>r»vr4l
L'vxiiin Rtrimn In one raeriiiriiYnl tmpr<r>al ttriavo rohinM*. f>f nrvr 900 pufr*, vrjtii 'iti InrM:
Mill dat>i>rAie ^nrntvuifi on WDixt- Price In uxtra ctoib, H S3; iMlb^r, nta«d bond*, 87 (Mt;i

Th« 'pecdv «[h«uiiii<» of*. \*tgt (Kliiitw of lhl<t wn*t fa i«fltpl*int evidcBoe ihai Hi p'an nnJ cl.. ,
Oiitk'n hRTe tWii foDiid lo pr«*» ni •iip'ripr prarilcal B'ivnniiMi** in raplXiatlngr Ihe •IikIv "f Aimiv*
mv- Ii pii'^iiinK il lo ilix profi!>(i<Hi a •cpiiil iiinn, ihi- Diiihur hn* nvaitcil liiiiiF^eirol ll>« i>piK>r-
Iuiill>' Kit lUpply Bnvd«ili^>"K'i»'> wliiili (^periPiiL-r in ii> ittc haj ali^wn lo cxi*I, anj i<> nTrMft
any MTura of ife'ail, ici wbiob ilic IJ»»I cdioim o(b »fieiiljlio wurk ua au cxlenaiva ■ml ciimfilii^aieaj
■ ■(.-iem-a ta Iniblo. Tbi^us trnprurrnicala liavv nitillod in avTiic Iiufcaai.- in llie rij»of tiva Tntiiin*,;
whil« Iwvnly-aix n<>w Wi:iijd>riil< tiBT* lir<>« aiyril In thn Im^iiiriil ■#rttni of illiiMrali'iait wbio^
foiin an ili»iin.-fivB a fpalpro of ilie work. Thr Aitipnoin i-i||iimi liB»ln^"n [ia"inl throiiigblhppr):
tinik'r ibr ■urrmoitin o-r n minpF'Trnt prn)e><iiinnl inaii, who hua Inliirii rvi^ry ennt to render il
All rr-pmrt" ncL-iinitr, and i( ii mtW nri-i-pntn), Wilbuiil any incirusis of p'lO-', MB dUed to nuuuf
uid (Tiieiid lbe> \K>\M\htHy wh;i^ti i( mb cvcry(vb«r« acquirtMl.

Willi hiiIb I'nubls. ibo buiy praciiiioDfr whoaa iA«ai«i la ihia B<mntry, Mr. dray wrltNihrM

kaowlrilgf oraDatnmy mujrhairlx'r^iiiDc clMCiifrd hj Dill With IhiiIi braai<K<rB nf Ii I ■ anlii^rl in Ttcar. ftH
w«Bio( |intcii<ifl, mar n»w reiii*':itB19 bia rnrmer draeripiinnor «a*h partlFaJar part ii fnHTarfil by %
•oatomlcal Inre, and l>e rraily for an^ ciacneni-y. B'lUce uf jta tclalKina to nr nan* vriih wlilcli U ia

liiaio iblaetnaaoriBiilndufeli, bb-i dii'I w iS* ita- I eoniMfind, bbi) tMt, in->, lunititijiiy Boiplc f<ii lUl

OBBI alciBa, Uial Ihla wurk wiU ulllnuilrly tttnil In lbs sBipnara (if Ike niiriallv aiLturnia. Afirr de-
bt nf intat InealiaUlile Bd/aBtaer. aiid wc fr#l bbi- I wnHnji tht t>"nf( and inntclea, lie iitm n pi'iKiaa
IbShI ihel Ihr lilitary uf iIik iii»iIii-u1 iiiitii will •'imii I aiarsirifTit I'i tlie (rtfXntpt to wlilfh iim k'<n<n of
be MioaiilfiKl luri>m|<Irtc lo wbilrli B ei'PV "f > I <bv fXtrrmirlM ir« nt<>«l HbIjI*, lo^El^rF witfc Iha
WiMk iliit-a r»>[ riitt,- ilffuJiii] fjiu»iirl|i Joantnl I ani'idnt anil direi'tloa of till (Iii[i1iii-Miirii; :■.-, 1,v^ir(
«)/ ff<4. Sd'incr, July, tMll. I the frii(iII^Dti iir? tiiti]'.r\ti ^tf rno ii.

Tliia.illtii>iii..ni.iili bap-ovwIanJi-nlBrrrti.BOd ' Tfte .«l.^n nn yinlr. i, ,m„»rk.M-.
MHiUlBa ineral n«R- tUuatrtiloDa by Dr. WfMrna- •^^?i';.„:vJ,'..".'l'L''-!.''^.'''''^' ' '' ""'
r<ill. Tli* viiluiiin (a a rr<iii|ilrir riiinfaulan M Ilia
diaat^Iitif-tnon), Bail anvel ttir nctfeatilv uf Ihe atu
tieni {"'atpulng a vaiirir uf" Man nail, — In* Lan-
dm tanccl. Fab. B, Itillt.

Tha iriirk lurforv na la dbb rnltllait fi iba hi|lhaB<
pralae.anit ire Bi*eo»lin(lr welr^ci-nin it aa ■ Valu-
■ble BiMiliKD In iiirgliral lit«niiiite. I it I* r madia I*
la falnraa iif ilrtail Ih-iwti-ii the Irnatiira uf 4tai

CBJ* and of WilaOB, Ha rban«(trUil<? aioil Itrt in Kaatn, alTorJInc a oiiii|iliiti, vinn- of iB" aitiirinn laf
ic BViaboT and eacrll'Mirp ••( (liv rnKrairlaia if Ihe hiiman IVMlr, Wiltieaperial (efEirace lii|iiaeti»al
eoatataa. Mnit iv( tbeac are "tlpaal, rf niDUb *an<ary, ThiiairiavnliiniBmnalitalraaprffpelNuiilC
lar««r than urdtiiiiiy aii*, and admitalily ea«<rBlfj I'f refrirnnt fct llie |5i«f Litn.iwi, ilrinAiiiJIiipi a |ilar«
Tbo TBli'-u> paMi are altu Jciiercd after Uo plan is avail c>ia nu»l litniinl librarf of the phyiiriaji or
adoplad in flitldeii'i Osimdogy. tt wmild ba niffi- aaT5n>n, aad n Wiirt uf ni-craaily Tur Ibi- tludral M
calll««vtr-oillnat« tAt BdaBnlBacB nfaird ty lAu Ax in hiimiait wHbi h>> hai iMtaedb^ ihediis««tiDg
IBoda of pietndal llIiiatiBiinn fiiinea, lignmrcia, kuitr (miTi Nii^ ho'ik uf n^tiiir — n« ilatlia Qmar-
nnaekB, Dli'ddrfiawlB, and Bf maaia neh in tain '•'•'!> /luntil f/iUfd. Scttac^i.iNur. 1M0.

SBiiiad, and marked wlilk inairaiiptfipriata naniFB: , _ ,_ , ...._* ^,.i . . j

ll>uatnLt.iLt.rthc.t.id«ntl»«rtnpt«hand,BlBjEl.ile« , '» •oMa''KniBnt, Ihfl mfvje of lllnalralim nJnptwl
arkat iv*™i.f oinervrta- ofienba iRnorad, or ai aay 1" ihe pra«Bi mIbiiw i«no[ bnl prBaaai in-ny "fl-

ptintW ln*.>rela.inK,wr,Ui<Hvooi.iine«illh* <ll«'lpl«-f V™!,ui mrn.aily Jadwiei rj t«l lia.
Wnih Of Mr Gray to Ih^ iHKitiiio of ttia mrdie.l l"7V«B1-nl, Iha b,«ii wil reHaialy be of ,i»m»Bi

;BO«eoftl.ri..«.v.kaMe Lriouilni.. -v^ rankle •>■' '" ^*'-"'""'f^ dealroua of ■' c,.,mm,Dg-' U

Dae IftM ''""""'* -'*■ '" ■*•"'*'!' a*"*"- , „r Mr. Gray', rood. nn!lLi.trali«B l.iJ.wBM. inui«

la thiB viavr. wa r^«ta iha wnrk of Mr Qray bji I ,„j „««i„iir i„ ,|i„„ «i,t„.,i, vrliieb treat of (Si
r bplter ailapf^il lo Ihe wanti of Ibe prnfe.aion, j fcfloea of the icad aol cl lh",i d«r«l..piBfj,l. TUa

e/[-ry iiTipiMliial vi»in»l, <t:.

Il'ia, but :tl Ihf- Tiii <>f Ilir .

rliil iiunk W hn*r a u^fIh

lnilt;(,i whieh limy rici-iir |>i iia i>rii[ m, "imr*!' nndj

t«f mtamloB ~.V. 4. Utif. CA(r. Xtviiie, Mat. 11S|

Mf. Grar'a bfiok, tn airclltncT nf arTariremnit
and enmnletenaai nf tienutinNr ^ii*«p.il« ariv wi^rk

on BDBioniy hiiiirrtdpiibliilipl in ibe I'.tiinai, iant

aad Bttwrlally »r U>« kladaal, lb*n bbv Irfalli* im
aiatciinjr yet paLliahrd in Ihla eno nil*, ft laitraCiiMd.
wa b«li*ve, l<>iii|ifrioda ill l>Ihrrr,bot^aa a manual
nf Oiaceiiiini, and a ■taiiiUril iif lefereace la ttie
■luilpnt riT ceneral <<r rrlacivf anatoiay. — If. X.
Joutmnl tf iftditln., Nov. I'UO.

Piir itila itoly arirnimble ""nik (ha prnreaaloB Ib . ,
Icd'Mnf In lh>! dialinRUiahrd aiilh'ir uf " Uray no j whtvb wp bnrp almaity aabairilly aJludril. — Am,

Iboefi'lciMi-" Tnavavaiivvil Allibai bws l<»if«lt Vrant. Mai. 9t(., J^ly, IBS).

tuily iif thea« paria i) lliii* ujailr iiiic nf c< utiparaliva
eaae, If iint of poailivr pin* ore: an J III i or ijiitbeafB
i>rih« liudenl, the wmpunil «"■■ iiiJipnuM lim-a, aia
■hora ol half ttwii |qr('>ia. It », la out ciMiii4iii>na
■n ad'niraMeBodc'>raplFi'>i«'i:-lK>'ik fin ih>- auiilent,
and a napful work of irfercaea for iba imriiltfiBeti
lit pteturwl ahsmeier fntninit a auvrl Hrmeal. i«

BLANGHAKU ft LEA'S HEDIOAU

GUIDON'S IMfTITUTK*« AND PRaCTICK OF '
Hl-'RliKRV. E<|liili nlili-ik, ibioi"i'«>1 fu^^ *1
ti'Ti't. W Mb Uiiriy-fixirplalc* In tw<>ltBn<l*>>in*
ii<>i>i«ii kiitumaa, (ohlsin ne ■twat t,OOU |Hltta.
Imtliri. nitM>] Ixul*. I-S £1' I

GARU.NKK'H MKUIOaI. i:tlKUIl>'TRV, f^r tli» '
■It* ''( I^tiiilfiilt iDd tlir rii-r'itioii. In niir fi>)Hl |
Vtmt'. rut . oliilli. |ii> :nw, wiil> wiKkl cut*, el. '

OI,r«l'.'» ATI.A3 OP rATHOI-OfilCAI. 1II»- I
TOLOdV. Trantlairil, wriUi NwIm anil AMf i

linni bf JoaarM Lkini, M- D, l» nae vnloi
vtrv Ufjc iiny«fiN'4iiarif>. *Rm iitMk, art'il
piipiwr fOilr nfforca, pUtn >mI cijorra. fStd.

Ht'<''HK9> I.NTBOUl'CTrON TO TIIK My
TICK OP Al'HCUl.TACltlN AND Utii...
MUUKPOI- PHV»|CALblAM;VO><l<> I.SMI
EA«i:^ OF TDi: LL'NO^ A.VD Ili:ART
DMiil oiliii^'ii 1 vvl. «ir*l Uwo^u.clsU.
3H. •100.

HAMILTON (FRANK H.), M. O.,

rrprt«a'ir tif 8arfi*«<r m ihe (•"ng Idanil Ci'll*«> Hiw|<ilat.

A PRACTICAL TUKATISK ON FKACTCRKS AND DI8I/)0AT10!

SrcMRil (•dilinn, rpvin-d >rHl iniprvvrd. In nop liif|[e anil hondKima ootMVO vol maw, uf ovw '
pajgcK, Willi nvnrly 300 illmiirHliun*. {Jint Htad^ '

The foriv ileniowl fur A n*w edition of ihl» wmlt (bow* thit it hi* b<«fl *lN^^At^f^l Ik tttmr
Xhe ciiilidt- nrvnt Ihi^ profefli-ion a' a sUndAnI auihocilir Tor c inHHinlinn Md fvAtrrno* on Ma tnp
•D! and <liini-utl fiit<i«^T. In kbhih po'^mit I1 (bruiisli llic pma-, tin: auilior ha* lakpD tbc Oi
liitv <>' rcvi^ it carefully, uu^ iiilruduL'V whalvv«( iippriivcirif'iii- havr l^'cn sn2c«»l«^ t>V i
«Xi>rriijr<-v aiid ubKtvHiiun An addilloiiHl ohapi«r on Ciiii-Hiol Fniciu/e* wtli ht ruUkd lo i
it 'till uiur« (ully to the exi^iiriea uf itrn tima.

Amiuic thnmaoT B""^**^'l"'^****'*'(<''V<'rv>'<'<ti . When w««ayt hitwcvcr. tvnt wf tirlier« II Mil
AiitniTH irar nil tr hem It t'li ttie'^vfi !■ Frimk Hail- i wnw Ulr i(i|itar* aa il^'- ' ' -• c'««nl

Isga IliumlU-iii and IIip v>iluriir lir^'ixi a> <*i wr wy Iff ttK |iiiiciil!iiua , uml i •iiii

ft wnn ■ pane of Wounilc^ |i|irioliiiii: the l>«alai>il i O'lmnlfir, mviiilB>t«,«nii - ip .p»--i

%n*fr. Ii II iti Tiln to atirmpt a rtricw nf it: aloihai ttirXHidiiiridi

amrl) ■■ vniE ti< i-rk fi>( any mm*, «illivr (if (Vim- timk wna •nlifrri*tiili'i.i ,

pilHi'm or »iBiM1on. Wc Uav* *<fa no trorli on < Irnm iti*rrF«iliieiu)<lpai>'»it It — wc 'iiick mti

finirtiral lurirrrT wtitch ir« wool') ■I'-iti'r iniiiii- . npxni'ii imv (>*' KailirrMi »* m iia Tal«« — Ki

mciiil 111 iiur brnllirf aarirciiia. taiif-inlly lliiiw ••( | lfi<fi<-<il m»it .Siir(ii*< JcurmiJ, Uaich 1. IrW

" ll.» .'.viMa." 1 r iSiMR whOM piactl« l>n m Ul.- , fha vftk (• eMM'iwJml.ciou*, aiiil ■»<T.nl^

lHnlawl.fr a ican hai n««»arily t™ frl) ''n h.ij ari«|H#J U> U* WabU of Uir alaOc/it. |irarlit»

own anai.ird ntoatt**. Th« pf«ctlH»n*r will *r«t .^d iD*«itigat«i«.h"in»aM» i- it.- auifc.- aim u.

In ilJiifctionarnt urarlf rvfrr piia.il.le tc-i*™-. p,„f,Mlua.— CWeiWa «*4. Jai.'«4i. Marrfc. I»«»l
«aallv U»tnt\ mat flomprtlieiidacl i attil nnch plcaa^nc ,,, j .l. <. i

iraiiiLr fur him lu muar. oirrr iii ihoaflrl coutliT-ta- W» (•rata Ibli V-r..I >■ in h

WoDoll)l*ca»M.— £d.afrM'fJiMiJ.yiJirni,F«b IMI. ■mhT-fctii w t»f r ■

; UTF U> rrvirur it IN

Tliia la n TBliutilt ci>niriliuliiia In Iha lurariy of tin- ininiT ul iltt ■-

nuial iin|M<Maiit alI«miMii,aiiit li III* niwir wit" on-', ■■[uniKU • x^'CMn) in '.liclni- w
lna*rniii'li iit at Ific prtaiint limr wr •!.■ imiI (i-aarx
a aiunl" cinijilnp cratue en Pr»<"uir» ao'l Dlaln-
eaUt.iiiiir Mil ISiiglitii Ucigiiagc. Il hni kiiumhimI ("r
Wm Ani-'k'ir lir'tli'r H'pf'Kliicf a cm p'f"^ '"■'!•*
npiuj tlir aufijrct,and tirirf tr^citucr in ncumrrnirtit
fnim ilitiaralteraiiiMiaBiidlmpruvcmiiiti lAal bar*

bwn maile from 'intew lime In Iho ircaimcrDlof Uicae ,„„^ .„i»,>v«. .^ ,■

Bt[>w(i"n). Odc ittm andiTAluabla r«il«if in lli« tcinrrta and • <v i'-

*<..fc brf.,rpi,.l» t^of.^ll^■Ill «.n>|iTi.M all lb* .incr'fl^ (.ngralalaiirtlif iui.I^Mi.<ti ..(

lmpr..iTmt!.'i iniffJiittd inti> ttic piacuee of both ttuitfi i.n IJif a|.?«f«nr. o/.opbapul.liM!

I.O(i.-J.nml An.-rirBii.iir(efir.«nJllu.u(chfaf fr.i.ii ,„„„f th,i,n„„(^,, Wr b.vp f-axoi :

omitiiw inm;nin,.ruuf riiiiiiiin.iul i.r.f Mn.ra, llir of « ,, an of iKi»»l Winli.hnii la a liUrarr

■Uthnif.; iiiiifiraiii(ncr'^untKt'ili>eti"li<iu-battnu ratlSo polal <if view, QiiJ to vaircni it u a

|i>ev«lcnl Id ai.inr q.ia.iria-il.at nntlMnc ia aw.d ^^Idf in a moat itiAii.ll Bad imporULt bi

MUa» Irapqfli-d t'"ta Unn'-t of Utlmaay. _ TOe „,.iv ..d praoitc*. Off mOT a.r. ik(n4'<

lalirr bnlf .If llir w-ik i. <t«v<>ir<l t<> ihoooaaidetB- , wr h.inr thaui mar a.»a bewiJ-l' li.H.wa aUi

Ui« <>f ilic voTjoDadiilcieaiumtaul thflir arpfApri- a, HQ ari<i«ni:x affPnalaA prrj- - .a

alcl>cai>n[«i.,and ila nedt i> fall> rqual to Dial nf |[,r Aii.mi-, .nd liribrr, Ihal i .11

llwi.rectiliB|(porUiio^I»<i.aaJa»i.o»c.J,.M*y5, , wi<lrly an.iwn ai t.i.n.n.-« ^

■ 'nl|

l>ral (ji>»k ii! It* kia^ valanl. I{vci) i

in «ir|Fr) will tnia hav» lEm w>ik

Up wIi'i iliwi bm, Will be Ihc luaer.— lYiir 0'''ia

Uiiinl JV>iF>,M«Tea.l««).

Dr. Homilliai U (-.■'-•-■- •. (■n-l--
eilinit tbe V'>l-). a<
lulic utiwrearp^r'

iseu.

friHB whieb cvrry nnr may pf<

It Ii f artvliillCBlIy l\t thonk apua the »ii>)i:«ti of . aff':>r4lng aa exampiti "f i>nn»^ '4, i

WtitrHi It Irvaii, atn) w« mranm doubt thai it will J UBliiiai indaitry iii auihi>i*Ai(i .'

OBBiiBuco i«bef«raii irnkfinita parlod of lima. | nav ■ik<il»«-- ^"*. il(4, Jvanaai, April, tsM

HOBLVN <niCHARO D.), M. D.

A DICTIONARY OF TIIK TKRMS USKl) IN MKDICINK AND THR

COLLATERAL SCI KNCEti. A n«w Anerit^an ediUon. Keviavd, wilb nuiaeruaa Ajdditioaa,
by laaAC Havii, M. D., editor i>( lb«" AriMrricaii Juunial wfibr Mu<tic«i Sciruut*." lame larii
ro}-a] ISinv vuliunc, Ivallicr. of vver .VX> duulili» oolitMtied pagaa. >1 M.

Tobi^lb pTacHilonei Aa4 •,UtietiK,-w* refDiQin<nd Da«i ambraaii)(«trFn'deran»eaiom*diMlaoli

HilidlrliiiBary sabrlni riinvciiiPiil ill ■iir, acruialr I dnwn to lli* Vory lulMl daM — ir<«t*>* L»»ttt
In drilail.Mn.afld auBieiPBllyfoM aiiil j-nriplcw r.« yablvnaDioUo«m»aa(«M fc««i af»T(»nta
ardtnatrP..»«a|tall..n-(Aa^«i«.M<d. 7..ni „ ,, „ ,j, j^„ b«* nf **nlli.«a w« Aa*,

Wa knew nf no diattiinary belief arranird and oaiihl alwava tn In apua tlte alaitenl'a Ukl
n4ajited. Iiiiiti.ii-niiiiuiixmu wi:iitii»>itj*iilrtriPi>nB I SwiiUm M«d. aiad Jtaff ./MraBt,
bT K byiiv>« ace, but It CLUiUina uU tk^t ato ai)W iu I

HOLLAND'S MEDICAL NUTRB AKD RS-
PLl-lCTtoNS. fiura Oi« Ifei"! Ixndoii «dliii>n
Id one bandaiiKie M:lavfl volume, exira cixiJi. Wi-

Aoa.MtR-S SPiaClAU AHATOVt-i kSU Wti.

TOI.OCV. Elf hiti afllitM. GxlaMiv-lyii

■Bd ■niHliand, In iwili..i( oK'ii- iUaDlOUUfa|««, wkIA wMt :
tUu»i(u,(iMn*< t> w.

AND BCIEHTiriO PUBtlOATIONB.

lit

HOOOEfHUQH L.i. M. 0.,
ON BISKASKS PKCl'I.IAU TO WOMKN. inrbiHinp Di^plawmcnti of the

I't^ru". Wilh oi-JcrtiftF JllwJdili.xii' Fmi ..do rwiiititiiilj- pf;(H<-d .x-taVo Vuluiiio, uf iiMxIy 500
T^U'i-*, riira clotb. $.120. (IVeur Hf'iJy.)

print* unanuf'tDrBt— hli nmii^eeiperlpap?, tiif ma.-
I Hint jai'niurnl.aa'l hi* prrfritt i:'>n»>imiiniiRirm»~
inT'ii tliia |)uhliriiiinn Willi an initF'ti tret viiluf In
ohirli Tiw ••! Ilir inrJicu) IkiIkti of ■ rcTFiiI imIq
Ibe ■uih'!'''* tupp'iaiire •» eirarly ravoilnl ilioi tht j ran far a firiinfcr. if, |>ei«aaDMi, an rqua] cl*tni-—
mllrntivr aiadriit eamnui Tail lo inannr af lodly pat' Am. Jomra. it'd SfwiiHJ, Jan. IMl,
tlonm •Im.l.nuireMtiiil'itwnr'"*"'^ .!"•■ ! Iim^rtf alih-ofh noranorib* voloii>el*ai<1eip|.
Ctcdil l« »li mrJieal i,ler»lnrri and wr add, thni 1 „,„,|y dnriv.M "t prf«»l.niJ «lud> . wrUnok Ibnl
til* phy.i-m whn < iw. n^i pl.r^ k Ib Iu* ll'.r«fy. „„ „,'„, ^,„p„„ nfynwd i,. ihi, ,hi,j»"1. sr« rapt-
Uld wli..il..« ■!.>< f«llhfBllv roQ lla pn,«, VV-\ l<w ^j,,,,. „,^ „„,, ^^ j,,,,^ „,. „„ ,„..,„ ^„,„,|,|, „,,„„.

m,-itully wf II: hdiI Wr. trill nirMrnrsf vinliirr thr
■carniJiii mm fi will InaugurnlF an iniri'nvrii pmr-
lit« lt>F<'U;t>oul [hi* i«hi>lc F'lunlry, Thr _»rcn-l» .'f

I Vaal c)ral urkaowlritfc Ihal Wi>uM hr iiiaat ux^rul
U> tilmaiU aiiil braeCelil Ui Iila piiilinii. It ti a
ftnrli'ni wart tt/llu t'cttir or-ltr »f mint; anil il
«rlll lalir iKnt n* atinti Iniinwlrault — M/arj/laMit amd
riieiHfU tl.Jieal Jamtnal, I'eb. IMOt.

Tlii>«irii(Til>it(iiMi Icwaxia t)i« al JFidniion of th«

p*lfar-l-iy aDU irratmint of a<-ma of iln diamiara

jHvaliiir u> wnrrn. caoniit full lu maei ivliA afavir

tMt rt^'CDli'-ii riorn Ihr m<dii*'il iji^tfiaaifiD. Tli*

chara'tsr of Ihe parlli-Lilar niaiailiia I'f whii'h tli*

Wuik btiri-rr Ba Uoala i thdi frrijLfD^ii, vaii'-ly ,*liil

nhfPiiiii): ill* amiiuk' •>' ntalaiai-anrt i-vrc uriiMiiiil

■affrilnc iiy whw'ti Ihr* ure iftmalily atlfu^ttl,

llHiiT nbailniti*y, ihH riiinrtilljr uiilh wrtiiPh it>ry a'c

Otrrr^tme, anil li cir dlapnalUuD airnin an J 'gain t<i

IVrvr— ihrii*, [nktn in cinnnrd'ni wiili Khr pnlin; ^m-i^ niF pari i% '>■ ilarlfa iiaiial viitnalila n-inirilia1liin

In III'- piBi-iir<- of iiur ur> — Am, K—t Uantlilif mnit
ytn tfk fUruw. Ftb. IWl.

CiTaniirlmi.')' i>l lli<^ uullioi to iriirlri a ei-iiftI »(•
•mini tif iheii calBre, ihrir cBnact.BKJ tlieir appiv

Ifapli niwm in* »TJiiyi<>in., i>ro(Di>an, rmI ii'.ipiii«f-
inruL ■'>l [h*^ae annny iDf malii Jiaf ibnu i ■ '^>niiiiuc4
hy llila p»it nf th« w..rk. W? t*nn'ii ^lll itturHil
aa trua nf ihe moal oti|tinalasd m j«l|tractipal wnra*
I'i iht Jiir: •>»« whivn evrr>* BcroiiahFui aail pti)'ai>
pUi ahiiolil mual parrfuily raulj for wr at4 ^rf-
i^adfd Ihdl hA wiU anar rrrrni ila priuaa] iti:1i nf iv
iiirta. whlrh will iDtluri hlin miii a m'>F> ratii-nal
pfaplico In K^afil III nianr a auirrrinc t<-iii«le, wh<>
iimv li«v« plmrnil nrr IimI'1' In liia IiiuiiJa. — £rilii4
AtiutieiM Jemrmal, Pc!i. UQI.

f>f Uia n»«ny axi'i-llanri-a o^ lh« Woik wf will n"!
■|irdk a I IrnaJli. Wp»lru« all tirh« woulil aFigiiito
a m iiwlf'')!* "f tna pingitr i»ana|tHnrnl nf I ha id.^Ib-
itira of wliii'lt It trMla, In atvtiy it wilh rarr-. Tti«

Tbe lltUfirfttifBUii wbieh are all orlfinaliAfednum to a unirormacaleaf cine-half ihenatitnltlaa.

HABERSHON (B. O.), M. D,,

AhUibbI PhyakUn tOBnit I^ctntrt nn Mulrri* Meill«>Bnil TIi<rap«allt«ktCaT'aBi<aplliil,&«.

PATHOLOGICAL AND PRACTfCAL OBSKRVATIONS ON DISE\SK3

(IF TUK AUHF.NTARV CANAI^ Or^OPHAKirs, STOMACir, C/BCUM, ASP INTK*-
TtNE^. U'lih illu>lraliir'na »n wiHxl, In nn« bandiiitne orlnvo volunw of 312 {>'K^>i ritra
_, a(Hlb SI 7!i. (jVein Kaad]/.)

^^ JONES (T. WHARTON), F. R. 8.,

I PrnfMBCi > iif n|ili11iHliiiir Mrillctiie anil 8ii<grry lu t'uivrfrdlyCnllcf R, LondoB, ht.

THE rni.vcn'LKs a\d i'ractu;k of oi'iitiialmio mkoicinb

( ANU SlIK'JEKY. With ime htmdred and teti illii'lrmlloni. yecr-iid Ainr;rt;-un fri.m ih*^ sproiK]

and rrviK."! London MliiiKn, with ■drtflion* by Edwikb HA■nll□x^K, .'4,U., Sur|Ki>ii i<i WiiU'

. Bovpiial, jbc Id oa« l«r«iv, lituidsoffia royal l3mo. voluaw, «zi» clutli, oi 90U pacia. tl 30.

JONES (C. HANDFtELDI, F. R. 8., & EDWARD H. SIEVCKINQ, M.D.,

Aaaiaiaiil rhyatciitna anrt (..rotiiirrta In 'i\. Marr'a Hi>«(>lial. Ij<<t|(>i<a.

A MANUAL OP PATHOLOGICAL ANATOMY, firat Atncripan Edition,

KcvihhI. Wiib Ibtci^ hundred and ninciy-^MMvn hati(]!i()ni« wi>t>d tfogtavlngn. In oitc large and

beantifut octavo vi^liiinc of nearly IW |>ai:M, l«ailwr. U 76,

Aaa oiitirilavlrKl-b'^Kli.evinluiRinii.ia 8rihndi>n«Mi i 'iMIkpiI in||I»«n fioma^mil BBiiihcTiirni<ni'«r«|>h»,
form. H c>'iii)i!i>lr niiltinr of M-lial la kiHiwo In I lie anil tlinlirlil waa aiiralniaivr llialliiil frw oillivalW
diiraain <i' Patlwl'f ical Ataunny, il ja prrliB|>a ina it wnri any ilni'^c "( tuvocM. Aa a atniplt itctIi
b«*l wiifk ill ilir t^arliiti lanvuaca. Iiacicat iiirnt , <if :nfrinn[-r, thrttt'itr., il la iif p(i(itl raise !• tht!
cADaiau ID ita cnmplctcntH <in<1 trcvlly ^acd in >l<ta , atident «( iMEhiilivicBl Boal'iiar, tui Uould bs IB
reaprl it aujiplira a ^trai tl<-a>il«ratuin in <iur liic< eveif ^faieUa'a tibrBty— Taauna 6aaKi.
moTe. Hcictflfufe the atuOecil ai pnUiulu|T Wm I

KIRKEB (WILLIAM 8ENH0USE), M. D.,

DcBKiodnitii'or.MMrliid Aoalomir al ill. Bartbulumrw'a nnapilal, &o.

A MANUAL OK PUYSIOLOQY. A new AmeriwD, fn.ni the third and

Impmvtrd London ndiiion. With iwo hundrrxl Kliiairaiion*. In one Urge and haiiilaottM! (aval
I'Jitio. voliinio, IcAihCf. pp. fiSd. ta 00. {LamJjr J*ni/MAnf.|

anil tli nrpfotlr i^dnl anllK'nilto. 1> <* l^e m>'al

T*ii la a itrw and vpry mni-h niipn»vfit ertitinn nf
Or Kirkca' wrH'kn>iwii KaiiillH»<lc -if I'tiraixUify.
It Kiitihinra i-onri>Pnf«i wttli ciimplttcu'ia, arO It,
llinrF(»rti,B(lniicnMy iiilni>lr<l f'lt riHiaiillali'ic liy the
bBiy praeitUonvr — Dtttlin (fvariirlf J<Htrwal .

One «r the very bi^t ^B■Idb•lDlta of Ptiyalalaxy wi
{inwraa— tiiFsrniiciit jiiil aiiph an (lUlltnv uf tka aoi*
nnee aa tUr ttuilnii in|Uirn (luring hia allrndaDra
Bpiin a DutifaF nf Imuira, m fuf rrfetmi:* wliUat
prrparinf (<it csBminallnn — Am. Mrdital Jnmrm*!

JueicclleDflBlBlg ita ouin|ia«uiaia, lEa clcaroe**,

nunrrairntii^l'xI-lyHika. TbPacgmllcoiTu, Mrura.
KtiKi-aaiKl PaKcl, havr lb« flfl i>r l^-liirc ci ivlmt
we want tn kontr, without ihiakinit it iin-raiaf/

t<i t«ll UB all ta«y kMW £#!»■ Mtd. aad Smtt.

/oBnat.

Pnr lb* alndant baglanlnit tkia atu.ly, and ika
prarlltiuaat Mran han bat leiBUte lu telir^ali kii
iBpin-irTglhiBbmfc la inraluBM*,aa it ci^niainB all
tlial it tt imiiuflaiit M Kauw.— CikarfDMa M*4.
/«antai.

BLANOHAED * l.KA'8 MEDICAL

KNArP':^TKXtlM)l.1)(iY i irF.CheMiitFy afplic^
!■■ Ike An* ftttil (o M>aulBiiliiT*>. R<litad Iti D(.
RoiAini. Dt Rii-iiiiiMoi. oiiil Prof. W. R.

Ml tn-ml cngraviagi. ti DO,

rUKKS ON THE Itllta'

. lUlti» OF \ltLIMC«L ui~

.:,U KF.^r.f,SCU T^Attm

la line 'uyal ISwi thIuimc, cidb cJwUi Iffeafti.

LALLEMAND AND WILSON.
A PRACTICAL TREATIHK OX THE OAUBBS, SYMl»T0M8, AN*

TREATMKNT UV SrEKMATORRHcEA. By M. LaLLBM-jcd. TnuuUieJ ui Onr^ H

JlRhiir J MrUnraiLL. TbitJ Ainoniko odiiina. 7« waK" '■ ^ '-^-i ON ntf*^tg4

UK TIIL VKSlCin..-!:: gJilMINALi^::, AMDTHBta amoou: • M'lili (^kmI mv-

enm [cibp Morbid BcrrriiiiiKul tin PriiMuiic and Drellirai .' irnlxaiK. BrJtana

Wiuox.M.D. Ijione jieBlOcUTDTolwBi«,of«l>o«lt4(Npp.,«s.ut.ciuLii. ttirM. {/tMiwaMU

LA ROCHE m.t, M.D., &c.
YBLLOW FETKIt, oonBidcrod io iu IliiitorivAl, I*albolo^okl, KtJol<u^iil, W
Therapeuiical KelaijMiB. InctudiBf • &lc«(cli uf ihv DIm«w as ii Imu oc«arrw4 ts nibMpia
from 1009 to 1^, wilb«a«saniiaBiionarilit>«ouii#c|ion*bclw(ira it sad lb« I'rrer* kav m «to
ibe MMnf nune in orher pan* of irHipvnit* m we4l •■ ia uopJD*! ngiiins. la («• Ikifr ■<
hnniTwiiiMi <M-Ta*n rolunuu of nenily IMW p*g<^ ejilm clotk. SI H.

Ft^m Fm/tiier S. U. Ditki*m, Ck»tl**tm, S. C,
S'plimitr Ig.lMS.
A m'^nuinrnt of inirlhiicnt •aJwcll iMlicd r*-
•Nitnh. almual williuut tiaaiplc. It la. lAilMit, In

the apn'iul (cd'-Fi ■'• H lio'k of rffcrcnre, in the
auUlfl >'f whiffh It tioii. to ■lITDlan tiiur.

WtkavcDolllwBkt prMcAt. camced a« we ate, L_^
bf Atf andky aiRlii, ia Ihp w«rk of eambailnit lii'i .*??'" '
Teiy illiHip, DAwprovailiax lanaieilT, to<lonKiie "'^■'IP, ' "'^u

Iban ,,v tl.iar«[^..ffi..l,M.ot wl.M w- (...r.^.l-f < l>e«I»«l si'"!; ^- U-4l Itt iK.^l.«, w, iii.r.L)ai«k
a« ari3n«i.to<tr Ikr ii«»t able aiuJ "ii.lil.- mrj.ral ' •W" anJ o—P'f »'•»■"'« ttra.i^ ."'"JlLlf'?!?
^uMtralion uHf e..di.lry baa yei p«WuL--il But in , '""r W*^ « U« awaU^ftl.-ir*" J<«* *«»*.
tIbw of IbeMartliacfact, thai lJii*,ILc miMt nii>li|- i

BY THS *AMt ktrniOB.

PNEUMONIA i its SappoHed ConDootion, Vktii'ilo^col anil Edolone&l, will !••

CuaiBal Fcvrin, incluitiriK BU Inquiry into Ibe KiulcDuiaiid M^rtidd A^QOf ofjUan*. taMi
Iwndsoiuo ocl*vo voluoic. extra dulh, nT.'iOa poctra. S3 00.

aanl and BBTMaivc«M«

•WM-ttf r>r In^rli Uaat,

haa r>ir iprrial ' ' .

■j»tfT

tnaircatM cj

.1 1*

l(ia(rr «i«Aif ■

■I ka

pcarlral/1* ni.i
nrui'i; Itikt 1'

• , fi^jii^Liii.inL h3it (W^
vita aeatkctj Imm **•

rwM n"w 'Iiai

'..' ^--flfasc^ Ihal llBfl*

1( vnitiii

k>«.

■" -l-lri,

LAWRENCE (W,), T. R. 8., Ac.

A TREATISE pN DIHEAHKS 01' TUK EVi:. A nev c-

wilk nuiiiirrDUs uddiliiHi*. 011(1 343 illupiIrBlioiiH, b]- Ihaac Kav«. M I) , Surgn~' ' ^^

tail Acc> In one very liirxc mid tutadtuOie uci«to YoJiune, of 930 pocn, tirvagi^ ■*iJia

■ViUt rviaed ImuiJ«. »5 (So. ^__

LUDLOW <i. L.I, M.D.
A MANUAL OF EXAMINATH)N8 npoa AnaWmy, Pbyuiolngy, Smg^,

Prai-tic* iif MfilH'irir.Ub'lFirlrs. MiiicriD Mcdii-a. l.hcmi>(Ty. I'turinai^y. aiid Tb*r*p«aUn Te
whicti i> Bijilt-tf ■ McdH^t Fi>tiiiular]r. Tliitd rditim, lluirouglily revnetd and ftratlymMM
and rnlnrgfJ. Wiih ^0 illualtntiuug. lit oat tuuiiJ»Miiie rvy«l 13no. VCilame. k«uu, rf Bi
larye psfCM f2 SD.

Wr kiu'w 'if Du tiplier aiiuirMBloii (or the ttDilHi(| traaHnfrflfliahlvhaari bf tiM rartaaa pra<b«n« >
duriojt Ibc h'lxri ((icnl id llin Ini'turr nKim, ur lo r>> I <rb<tia br ib «iinpcll8d to liaMiii.^mi
fr«b,aia(laiiue, hidacmiity of Uie varioua topda I May, IU7.

henbUT— JM. JnaaaJ J|a^i»>

LEHMANN (C. O.l
PHTSIOU>aiCAL CHEMISTRV, Tianslatcd from Ibe whwuJ wKi'k*
GBdRosE. D*T, M,ri.,F.K. S-.aw-.edliedbyR- E. Komat. M-D., 1
in ttiR Mi^difai brpnrnirnt of ihe Uiiivenity af I'eiintytvBiiu, with iUt-
Fuiikir'i AiIbb nf rbyoinlugieal Cb«liii»trr,wid aJi Apptwdixul gilaln. C^'tnjiir-p ic i<m
and haiidtotneoit-tavovolDiaeii, extra cktlb.cotilaiauig 1200pa^*, wttlineariym bnsAral
lrati<Mi> S>t 00.

Tbe we'll o( Li-nmaen •mndt oDrlvalltd aa th« [ The moil innonaBl roBini-nUMi •■ r«i
»uBt F'^niiircliiriiiivF Utoliuf rcfcrnoceaail lafufnia- Pbfriulagleal CheKi'
U^n Bilaal'uiovrrT braccli of Uic •ul)j»ntuii tphteh (MM), Jaa. 160.
II tnuta.—Kdimiatfk J«mi»at aj Mutual 5«J>h«. |

BT TBI KAUI aCTMOK. {,I^**lf PMithtd.)

MANUAL OF OHEMtCAL PHYSI0UK3Y. TmnsUtod frani tb«

WUb NouM Mil Addiilooii, Liy J. CuxsTon Moitiii», U, D., wiili «b lutrmlariiiry Bmb*
Forn, by Protnaur Samvbl Jackbok, M. I).,of itw b'iiiv«r-jy ol PeuiikylraitlB. wi
Inklitxia on wood. la ono Ti-ry himitn'mr irftr"- vTrtnnn' rn'r* r'mh nf TTj It— 13 3S>

Fromi I'raf. Jiui$tm 'r huradveiBrj Knaajr.
Ill Bdoptias lb« bandlnMh u\ Dr. Lvlimann a> a mamin] i>r OripmH- CtaentMrf Cir Ika ■■« af
tnttkeii of IB* Vavntnij, and in ri-.-.-niiiirailnHic hiaotigiiial work of P*niiou>aic4LC«i«
for tlieir mure mBlilre nludir*, llic hitrh v iiinr nf hia rew!«rrlie», a/id tkc g irat wvtgU o{ kta t
my ui tiuit importajti defwrUtuHit of ntirdicAi aciaiat! aie folly KCofBiavd.

BMBViariiBn

•ftritJ ^SLIOATIOMS.

LYOf*« (ROBERT D.), K. C. C.

Lata Palboliwiu in-chiel ut Ihe DriUilk ArniT tt iba CnnM, Me.

A TRKATISE ON" KKVER; or. ji^lfctiona from a (lonrse of I/W^turcs on Fever.

Bptng part of ■ ivurv i>f Tlm>rv anil Frurlice of Atmlicine. la dim n«8t ocIbto rotunw, of 363
pagn, extra eloth ; fi 00- (^Vub Rftutg.)

W« have $rtmt plnaure la rer.MrinciidiD( Dr. jdna. Wvensaidar th« vrork B mall ralaakla a<Mi-
Lfda** wnrk an Arjr Id Iha ailrniina of ilia prif> ti"s to mnliiuil ItiPiaturn. iiid (inrilaTlant i«wlal4
rfAtinn. Ii M a wmk wliiHi meiuil (kll ii> rahauoe' an liiiLr laAurnM aver ihe miQdur tlie|>t<<cMi<iB.^
(he anlhix'* prrvfu* u-f1l-<wrn«d >({>DlBli«n, ■( u ] Mft ami S<ff. Ktfotf ', May i, >W.
dilwfrl, f^rrfoi. unci aceo'aU ul>«rvct,— SrtiuA "nil. «»■ BdmlTaWe Weill t.|w>B Iha Bi'-^i I'Fiwrt-
If'. rnrHat, MarcBl, IWl. aMnanit m.al laporMDlolan of iji(rnir> to which

Takre ■* a wlii^le wo (ae iwi'ninmmd it Ib tbe nanlUd Br« llania. — Mt4. Jaara. ^ A- Cartlimm,
hlgtird irrm* ■• wrU wiinhr t>i« i^iBful [wruial Majr, IMI.
■•d iindr oTcrerf aiiMJent and praciiiitmar orncdi-

MEIQStCHAflLES O.), M. D.,
Latrlr Pniraaim i>r Olinininci, Aa. ia Itw Jrfaruia MMival Co41af a, Phlladalf hU.

OBSTETRICS: THE SCIENCE AND THE ART. Foorth ediUon, reriwd

Ukd improTc^ With one hiindrni and Iwenrf-nineillrintnitinn*. InmwhrtiiiitrnltTnHnlfl ai^UVo
Talume, Iftalber, ol aerc-ji huadred and Ititrlf lar^is pAt(ea. $4 OQ. ( A'ato KtaJp, t'cli, I8S:t.)

In hii»Pr«tBC« (be BUtbor remarin! "In ihla edllloa t h«T« endearoR d loaiurnd rba wnrkbjr
clianKri. in il« turn), byoarvlul OitrrMllMia oriDBny «xpr9<''ion*, and by a Tew (imi<-*iim* anJ -otna
addilioni n* to Ibi- l*ii." Tlir MuiUiil and f>rari h iimrr niKy ibdnfor* r«ly on kmlifig Ihe rubjrct
IhoTDUgbty broucHi <ip In ihe pre-rnt linir, »ii(J I hut thn nitw •dflioo i'b worthy a ixmlintiiinct! uf the
T«f J" sraol lavar wiiti which iho wutk has br*u reteivcd by Ibe pTt>r«>B[aa.

T)ioa(h llig work hia TMi)tTc<1 (inly Are iMiea or i Tho bcti Anariun word an Widwircry ttal ii
Balar^mral, iti cbmpU'K iLirniif|bi>ul wnt Ihe im- | aocpHlble lo [he iitidmi imtl praclitiunDi— X, W.

raaawletliag tta aaalrnw* will. .,. rH«,,n.l ji^w am- . ^hi. i. a .laMard wi.rk h» a «r.-ul Awerici. (lb-
ler»il.allp.r,OM«li«lrd«.rrili.lit.h..ld«crvr '„,i,i|.,„„ ], ,, ,h, ,hi,d ,„d U.r r4.Ii.'n, an4, la
^ ^^""T' " ""I'«*>^ '" T'Tv" ■"'^" •• llielarB«»fC..Hh"nrrf.r^.llir.iill.'.ih.r."V..ii.Bhl
•alttr. la the ■o.i.f, e.rT) -"<>K"*f ttl* pea h«. „,, „bkr( up to Ihe lal«l datr. ..f tr^I .«,,«««-

'^"fi!S*,''" "i* °' "•? '•'^'*' '""' '* "'*^^* ' in«i m oar aVt and Sw««oa."-;»«i»i-i»« yo-oi- n/
Bodaddliiooa— tCtfUniLaH*!, i Utd. limd Smg.

>r THX lAMK arTHOX. (Just ftmaj.)

WOMAN: RKR DISEASES AND THKIR REMEDIES. A Scrionof

Iitrvs to bia Claika. Pnurlh and Improvi-rf edilion. In one \arge and braatiTiilly ptmlad octal
Vuluiue, lealb«r, at over IBC pu(«>. t3 (X).

wiiirli vaanoc r*ll to rtemiuiMnd the volame u
■(iFotloa o{ ibe laadcr, — BoMklmg^i j|(ui>*«i.

I( vunialnaa vaai Biniiantwf nracilcal (iiuwla4|B.
ly iiiD whu h'la ar-uatalclr obacrvcil aniJ rrlain«4
ihc FXkMrimcc of i»BO]r ycari.— l^xtlia i^aarwrjf

Pell of Empnrlant ■Milvr, «wir«v*d In a rnady aii4
•grvTHOJ* luanuf T. — 8l. Lawf* Affd. narf Sarf . Jtmr,

In ri|ft*T rMpMta, to nurcaUmBll<>n. Iirarnuiilj ean-
•04 be (111) 111 praitn ntOiii wiitk [i ai«iin-1a with
braaiirut paiaarca, and fi^t cnDciM-nfat, Tut ndeta-
alltr, and tai all tbal it cuiniiirniUl-U In a work on
th» diacaaM of (•^alei, It ■■ net c»nrlled, lud pro-
biMv nut Mnallad In Urn F'ii|t1iili laiiBiiaga. On th*
whiJe. wa know of no wora tra the dlBoana* oi w»-
Diaa whira wa oaa a« punliallr enuianBd to tM
■larieal aod piactilioDsraa Ibc una bafoca lUv— OAia
MM. BMt A-T /aanMj.

1
aM
elerve
MrlK
jan
nwR, ...... ^,,..<w^..-.,...... ■<« ^.. Y>- k™'; tl<* clrararH wiih whirJi Ihe totoniiati'* it pra-

..fO' M|-.(.,-ritt..I,nh"pinj..7.Df h..ialen(.and .^^^.i w« l.,>..w ..f n- *H-H»r ln,t uf ..«-'. «nJ*r.
?I«'?*'"I--r»* fiT«"» ■•< fari.*!. if.du*-C».. ,„a4,„- , ,„b,„, ,h„ tb« widcnc. ^ tbe rowar
"'•'"• n*™"- ,if liieiinrfxplaining il. Tho dkiI etrmrnutj.HM

Bvarf ehapt«r la nplrlr wilb prartienJ inatiiie- wall •■ Ike obicBTrd ■BbJaiiU, undM the ins ell (4
tloa.and beata UiclwpfrH iif iH-Mif i)» ciiiii^iMiiiinn I^ruf Mrif;a. aie iiulated aad madeinuaad oat ia
Ofaaaeauandaiparini^Fd tnin* There liawrne- furh him irlirf, •• W (rrodaMdlalUat inipraMioai
aeaa. and at Ibe aaato tnnn an amitarir in tii* dr- unon the nuad and meoiorf Of tha iMilal — n«

MtfpMM M Bynptd'tna, Bad ID the ralaa for diafuoua, I CJU/Ii^im Jfid. JeurmU.

BT TKt SaMK AITTHOK.

ON THE NATURE, SIONS, AND TREATMENT OF CHn.DBKD

FKVtiK. In B »rrtr*of L«li«rf>i addrcfHtd tu the Studeals of hi* UIb*b. Ib onv handaama
<H>nvo vottraie, estra t^lolh, ol SATi pufes. 93 dO.

Thr initrnatlra and iBtcr«aIia([ antbot of (ftia
Viitk . iirb'>ae previsaa Inbura liarc aJaced hia rima-
Uymea uadci daep and abldlof obll(Bti°uia> af«u
abailrB(ea Uieiii adiUfutian ia the rteali and *iK»r

aaa, BltrB«UV«aj|4i««rpaf«abe(«rBUB. lliaada-

l<«Ubl« bOQll, • * • Thli treatiM BBna child-
bed (ettia will have an patriiaive ule, bcUijt il<ia>
luted, at it deMrvea, to bad a ptaM IB Uc iCbtarT
of nverjr praetlil<'B(ir whiiKHiiua t^ilaii 'a ihe 'aai.^

A TREATISE ON ACUTE AND CHRONIC DISEASES OF TUB NECK

CiP THE VTEKITS. Wiifa nmnvrgnt clatei, drawn and caturvd (ma Bamra to Uig Bi^&eat
•tjle ul art. Im one luuiibviue ociuro t«1)um, «x,ir« oloili. t4 SO.

BLANCHARD A LEA'S MEDICAL

MACLI5E 'JOSEPH). 8URQEON,
SUBQICAL ANATOMV. Forming ono si'>luinu, very \wrffi imperifel aiurto.

With lixiy-cigkl lufe ud cplcndid Plaiw, drawn in Ui« beta «iy)« uid bMiiuratljr oolcvM.
utinnf o<i«lnuulf«duMl ninciT Figonif, miuiy el ibcia the »iK o' lilt- Tvnifevr w>tli<
■pdtiplMiniory lnier-pw»». sironiity miul hiuiflouniely kMind in «slnirJoiV t^nv «'■«
i!hriL|w<it nnd bc»l execulwl Siirgiral wurkB •" ye' f*«ii«l in rhi* (wwiilry, 911 00
*,* Tlw iiiid nflhio work prerenliilia irmnitniksion Ifarongh Ifan po<l><WRi« na ■ «rlmte,bal I

wliu dv*irc to ban cDpies forwarded by matli oui reeeiTc then in fire piuta, done iq» ta •!

wrappers. Price 99 00.

One of Uin ftMiMt nrtltfic Irlvrn^hi u( ih« *(« A work whl^h hu no MmDel In fwlni af
la Bd.r||l«sl Aaiuuiir. — Bniiik Amutittm tU4*ml tary aail (ibtvjisoM la c^>Ka|1lBk '"^~f- — f

JawAdJ

No pmrliiinnFr whon* ni««na will ailoul •houU
lUI to puMrM 11. — Hoafcfaf 'i ^(irtMI.

TiHi murii iraiiTi^ii Iw md m ii* jtreitct Inilm),
W« tiiiv« ii") NntruaRe lo <■« II }a«lie«.— UAw M*ii-
caJ aaJ Sarrttot Joaraat.

Tko iDKHi •■'TirMPlT rnirriivpit an^ *»aalifli1ly
Oelorett iilaira we liarc r.vri arm lU mi Amerirsn
bcHik — »«■' "C tha loai and i?hnip»i anreicaJ Work*
evctpuMlthnl^ — Bmfftto M<rfiaaJ Jeitrmai.

ll II verjr rat* Itial an clFguTlj- fiiltilrd, an an>ll
lltaatlatMl, ni ao OMful a wirrk, ia Liffcred at ao drjit, in any <P(ti:c
moderate • priw.— riarl»ipa Mtdical Jewrmat,

Wc aie cxlrrtiw))' (rauftcd U anau«a«a to i
|ir->rrtei<>a Uie ri.-nipl«ti<'a of iki* (raly aia|)
W"tk. whicli, aa a whule, oorUtal^r alaa
viillrd, b»Ib fi>r acrvMcy >rf tfrawinCt >

aiiloiini;, aaal all the requlilla «iplaiiall-i

aiihjMi In aaad.— rki mtr 0*I««m «•«**■!•

SarfVial /ovritnl.

Iia nlai'a Pan Siiaat a lupcrlorltT wliicb placet
Iheinalnbial bcyood ibcroaolKif couipettlioa.— Mtift-
imt Smmtmir,

Count rt praMiUncer* Witt find Ihfac plaWa oflai- ,
Meaaa valu«.-JV. y. Madital tfaifiM.

Thla la by Tar tkc ableal WMk uo Suifical
l>nn|' tbal haa r(>in« daitcr i>ur i>liarr ration.
Ini'nv 'if Bn ollirr W'-iK tbal W'>'il<f :"i->'i >

( ibftTC, flit ttoulf ' ^Ua»»-

ii'in la lhna«' au^ilta amaiK>: nCtaa

ariar. and whii-h rnjittiptlic i(i*i>i < ' ii.mai

■■f minatp inati?nif*l kiu>v>IhI||*, ■ win, .i. ui*
krr|u ilir ilri'il* III ihr iliaai>eljag>n«iiii ■■> fi"-
n<'ahtt] tbenrlilvn'.— T** W4$ttnt J*mtu»i */ Hi
«('«• aiad Sarg* ry.

*« pt«i^H
iiliVr^H

MILLER (HENRY), M. D.,
Prafaaanir nf ObalMtieaand Dianaca of Wuiiu.'n nrxl CliiMtni id ibc (JalTvrallT oft'iMtsTin*'

PRLNCIPLES AND VUACTICK 01' UB^TKTKiCS, &o. ; includiug the Trwl

Btient of Chfvnic liillnmmntinn at <he Crmi nnd Body of llw Ulcrv* nmaidered ai a lm)neal
caot>c of Abortion. With nboui one hiindted ilIuvlralMMia on wo«»d> Id oua very hamlaMHe •«■
lavo volume, af overGOp pagflo. {Lately PuiliiKed.) t3 75.

tVa diiicinlulain r-hnaulhoi tlial Ilia taak Uilonn. i Hon In whia)i ila niKilli jiidtt ptitlltc It. Th« alf
Weccnfjralulntc Inn Ihal hr hnxivan In Ibcmritl- i* lucti last lb* ■Ir-'- ' -Irai.aeil vxb

Ml pab)iP a Uf<ir)r whirli will ari-ufa tut biiti a nigh j>ri ■■ iiiituhfiI •- ivna ■!»« r*0

UA putHBBPnl ptwilliin amonit iba ataattanl aatl»»- IIi iitnrliml hrarii' - ■ utibiM fail le bhI

iill«a<in Uie piinnjplpa anil practiae of i<Li(i*l(ri.*a, I nc>r|<iiblc ai><) valuiuUc to butb (UijKaia aaS
ClOpraliiUiiomarr not Iraa our Irt I Ik niMliral pti»- I litiniiflra. We raniiil, hnwcm, cfoaa Uili
teMl'>nnl fliiarnUEilty, nn thaarqniailinn iifa lt«m- a'>ii«« Without PKnrralllall^ Ibf asthar
tlaaBMlbadyiniE tlie reaatlanf llMialudkai rrBwtiunaf piitTraaion un the |Mudii«t)aa of asah aa <
niM •xpariMiec of Prof.Millet. Few raan.lfaBr, ircailta. ThcautMiriaa waiMramwiofwhnw*
Id Ibia Fcniair]r, an moreo-nnpetpnl ltanah«tfl wtile f^-ri priiu<l. and waf^aiiam bat Uilah thai hlabudt
vn tM((l'p*rtni<al'ir«ed)Pla«. Kniagad for tOlrlv- win tad LAaarrtMtBMaMln'arBiailiBiraia slwMrrf
fire yrara ia an exlrndnl praclieeof ubiTetiie*, fur ilutcKici ■( l»a||htaad alixlini aa a ■« >•■»■• aW as
■nnnr ymrii a trafh^r r-f tnit branrb af lD*tnivll"n . art— I'^tL'iatiaaaiii.aauiiud Utirmr.
la nne nf the Utgcit of out in.iitutir.aa, a dli™i i ^ „,„, ,p,„(uble and r»Iu«hlo aiUmoc te
■lililMI«wellaaa»r<^f<>labMrver,aif>r>(iaalaad ^^^ v>ft\*%\ Ulerainr*, and one M«-^t.-« n-
[adapaadrnt .liiiiltn, w-d.l«l I" an ln.lib.r., .v.r ,lufl ™i the nuih... an«t ika .Hiiiuttm. -
MaJyMt,.rii.lrf w.tlH"itpffjuJieeBr«-i.|r»-..aoa „ „t.t|it.| TLe .luJr..,! will Sad ii.
Wad..ptinn.ivat(i™iflb-,n.,.rr«llj'iini«'>*"'iei.t», ninai iu»rol fU.ite to h.a aiudi-a ; U^ .
aaiit withal a Hrat, a^fwaWe w.ilcr, a prarliral i ij„„u„, ,,„, ,„ fc,, ,«^„- «» oi.i..,,
matlae *™" Ma prn ennl.i nut fail U. potMM frcat ^,, , (.„ ,;.„„, .„ ,h, „^^ l,i«,.,
niae^^al7aJa ««< Jaanal. [ ae.caee; and wt lii.|.r Uiare Ikta AiaritPaa

In (aot, niiacnlunetaiiat ultn Ita pMPaamnnKili* I iiim gwienliy oc«i«li«il by liia fru4«BH'
ataaCafdayitcninUoueatiaoaun okalatilcai a pnu> | JMad. JaaisaJ.

MACKENZIE <W.), M. O.,

SsTJcron OffulU! in?cMLtiid inordinary (o Kei Matnty, Ae.&e.

A PRACTTOAI. TREATISE ON DISKASES ANI» INJURIES OF

EYE. To Whii'liIfprrliMJuii Anatomira] IiitroJui'iioiiexpiuiiatuty o< a Uorounlii SwctMXil
tli« Herman Ey«bell,by Tiiomar WiiaHTDN Jokis, F. It. 3. Frntn ibi; Founb R^rtfcd aad T
tarired Li-ndun Kilition. With Nulca and AiklLliun* by Ai>d^IU, HswaoHi H. D., Sofvaao I
Willi Hi»pilal,j£c. !ce.. In one very In ruF and hrti-l--tnitrTtarrrTrtiifnrj Ifinlhtir. raJardlwiT*. tr)|
platen aiiil □uttieroiia woud-vtita, $5 'ii.

The tnailM of Dr. .Markt«zi« indiRiuialtly kotdi
tlla ftntplare, and foiini. in napaet of leanUttg and
rea>Br«h,an BocyelKwdia uacqiinlleri in extent by
uvothBf w«rt oiUielilEil.rJilirt bngtiabor forelfB.
^bizatt an Dinaif 9j tKi Ef*

F<iw nodrrn linokann aiiydrpiirtnu-Dl'<r nteitietne
Ornrgrry liavp mcl a'l<^ •orhnli-iiilril rlrculatinn.
tn baVK procured for their aiiili»ra ■ like amuunl of
Eiir>^pntii rrldirily. The liuiiicfiir rpararch which
It ili>i<la>>-d. Ihr tii(>p-ioib aciuainiui^ wlUt Uia
anblecL, plaiitiirallyaa weltaa tliniTetically.and Uie

UAVNB'S PISPENdATORY AtiD TUEKA-
PRirriCAI. RKMFMBnANC(.R WilAevory
rraetiiral FixiDiila pi«LaineO in lAe tkiee UrlUah
Pnarnuc^opiriaa. Kdilcd.wvUt lh«atUkliLi>iiurtbe
Fi^tmulc iif itie U.B. Phaiinac«t«UL, >>i 1L.£.\

■bIemHi]ii(>r iawhithUieauUior'aatnrMoflaaraii
and txfttine* wsrg rvnderad aTaiiablefi>r

nae, at naca piiwurr.^ Tor (bafiralnlitinn.ai
Ibt e'>iiUa<nt ai m ibucoantii, tlLal bifh
aa a atandaril wmt wliir'S rara (iie<-e**K'<
bat mure finaly raiaMiihnj, Wn r<«>M|i
□ aty ofiiTeiy imp vlio t>aa ilia (■••e of ai>
■nd the wrilarr inf lila i<alleniai Imrl, ti>
aair fmiiilmr wiih ibli the BintI ^<a>pl«lr
the Kaiiliili laaruaxp ar-m tbadiaeaaca of tbaa
— Mi4. I'loul naif (laiillf

CuvriTH.U.S 1 ltiau-vul.«L.

NA i.OAie.vE'0 opKH ATTVR sfnee* V, >

on Ni>tiHal and ralholiairal Aaaiway. Ti
lalnl fr'ia the Frcarh Lj Pai»Ka<(-a HatTt
A B.,!U,U. WiUiDuiiirtmilltBiiiaUiAaoa
\«L<AA>uMbMB« tivnaiia TOlam*. extra elMA,

AIVD BCtEITTIPIO FU 8010 ATIOIVB.

MILLER (JAMES), F. R.S. K.,
PRINCEPLES OF SUROBRY. Foarth Amorian, from the thir^ and nnetA

Eilinburgb »dilian. In on« larft" >nil Tvrr h'litiittit] vdmne, l««ilurr, orTOO pnges, wjih two
kiuidiwJ oad (aitj illivdnijoaii on wood. $3 7S.

TI>*w<>«(irMr. MiUt'i* U>ow«ll tadUmlavat- ,
■My tiTinvm uminna ut, ■• iiiif ivrmir i>i-ii Icji-hiHikt,
to renilei iny f«it»er bifIh-i- .-it it &ei?f«i.ify ihao Ibe

ftnumtr, • pi'tif of lU ritriiaivr '-ir<-iilali4in tmnt^
B*. Jti N n>iiriv and rrlinlilr ri|ujviii>iD >>f IhoaCI'
tare "f muiki'u •ui^iiv, it ituiil* liv^ivpMf hjch—

-Bfium Xtd. mn4 Surg.

Thewnrk tak«a Mnlt M-ilk WaiMt'a PncUMif
PItjriiC 1 It '■Mtxtolf di>M not (att lirhiiiil ihaL ^ rnat
Wiilk In iniiiarfiir** lit pri(iri|>lr or ilriilh Af Tnaaiio-
IDK Kiul iBM«nrti Nn ph/ilrlan vrtin imlac* kit >••
(luUtii'S, wr MMtkithe latccrau uf ail olti^nlat c«B
M^DiiliiniMlf )>«rorr kltU'xlaod Ui^wrrlil «riUinBt
tnaVtRichiiBHir ramilia' urilli the anaEil and philO'
•"pnlcal vi«vr« ilirci'iem la Ika (art%oiiif book. —

Wf TBI Uin AI7TBOI.' (JmM Itnta.)

TIIB PRAGTICB OF SITRQERY. Fourth Amenou from the loat Edia-
btinb «i}|iioii. Rcvioed by ibe Aineri<-jtn editor. Illu>t»lcd bf three biudmtud nxty-fmr
euffnvuiffv ag wood. In od« Urfc muvd voluint;, teaUiur, ofomrly 7W (mgM- t3 75.
N<> rRroriiiani of mica rno lit ailit (a the popolaiitj p l>)a worki, bdtb an tl>« prinriplea awl pradU's at

oiMiIkr'i fiurtery. It* reputation inUtia«oiintrr | aDrivrj liaTct)««naukRii'-d intKlfrhaal raalL If we

la amuipaiaol bi- thai or>cyocher wuik, bbiI. wbcD Were Umited to but oor wotk on autget)-. that <>aa
uKen 1a coBrwptioa with Ihc aullmr'* Ptim^iflM e/' abovtJ bt Miller'a, a* wc tMard Itaiauiirrlor to all
Sarfiry, eonalllm** • wlinirr, wltlt'inl rrinranvw olhcia. — St. Lawit U^ti anJ Smrg. Jatnnul .
Which r^i^euTiarjentiifiiaaur^ron wimlil tt^ wiitifiH tu
yraetlp-ehiaait,— Saaltana Mff-aiutSitrt. Jaitmai,

1 1 ll Ml do in that two Vi:4nm» iiavr. evrr iiinde •■>
pri^ciand ac \m\tir*hiiiXl tii *'> •hori a iini# na ilin
'' PriE'lplea" BDiI llip" rdi'-li.''-" iif Huintry liy
Mr. »lill»r— «» a" rii-hly nrrilrd tfie rrputali.m Itiey
bare ari|uireit Thr iiul)ii-i ti an riimirnlly imii

T'lenothut hnaia ititaaiul lii«" Fria^ipln," p>«-
■riilril 111 ilir pfiifrMi.vn'iiieuriln' iinin (-•■ii>|iI«Uiaad
irliaMr ayitetni cil ^iirfrry SXlaltl. Il^i Ityle uf
Wiiinji II origin nl, imjimaivr. anil Ciirtf: i n( , rcier-
ft'.t"^. ^••tifitt, iin4 lu''id, Kcw have uc raeiilly of
condrnainx lo mii'^b <□ mTnall apac(» araiJ at l^o aamo
limr v) iicruaieally h(>litill( I^jenllcmtan. Whcllier

bla, Biiii'iir-«1, and w-rll-iuforijiMl man. who «d."Wi a,,ien-bwili roi aluil-rta or a bw* ..f refeT«ii(-«
•aari y wli.i !,- ;. i«lt<.in al-.ul an.J eia<nly bow 1<. , f,„ p,„liu.mt^tt, it Cnn-t be t.m atr.maly «*«0I-

talk il,-S«h.!k» M'dttal «.«r4.i. wended .-S»i«*«m /nnMl e/- J««t. m2 «r»J*al

fly tAc aloinai unaninuxia viiicvtif iba pror««alaB, [ Scaratai.

MORLAND (W. WJ, M. D., •

PcMnw "I tli/i MaaaaehuaelU Medical thiclatr, As.

DISEASRS OF THE URINARY ORGANS; a Compendium of their DiagriOMB,

Paihol-'Wi 'I'd Treatment. Wiih illumnition*. En one lurice aiid buiidtvuia ul-iqvo voliun*, ol

•built 'XiO pBK'V. rsm vlulh. (Jwrt /mm«/.) |3 30.

TWkni ai a wliole, wo ran rccnnimnii Dr. Mnr- i i-fer Tlila dri)<lrTBliiiil liaa hr'D aurrlled bv Vt.
land't ei'mprndlnui aa ■ very dtairubl* a<ldilli>a to I MUnd,aDd it ha a bren ably itnae. I(r hi* |iUr>nd
lb« lihmry nT evrry mialipnl oi mrfiral nriKrli- i hr(<iir u* a full, JiiEtii-ioui, aiiij idittit'- ilinral.
Ui««r —Bril aadfuT. M«d.-C*ir. Ki«., Apiili IIOV. ' Karh auhjK^i |i irealwl with ■DlSL-i>«i mimil'-riFaa,

Br-o- nxNlic-l frnMitirmw wh..w ntlenti™ ha. I re""- ""•<•'««•"""»"""■' "rl'. •""I' ••;■' '""'«
bar»|«.,iy«t™t.tir.el«l tcw.r.!. ti.B rta.a «f 't'" *""« "" -f «r.Bt iri-t.MI, and -ae wl.iel. wil
t^mart to wBiDh thia liciili.r rd.tea. inuat havr P'""- '» "»' '''5^'V drg.w uatiol t" the tui«t»l
iOpHMdaordyupwleniM-'i ihr w-oi xf •uwehill, P«oUlli»Mr-— X ir./et«*».<r Jl«i««i*«.

TIT THE RAMS AtTllOt. — [JVw RtaJlf,)

TRK UrORBin EFFE01\S OF THK RKTKNTiON IN Tm5 BLOOD OF

Tin-: F,r,KMENT3 OF THE UHISARY .'^liCIlICTION. HemHiheD.-ertatkmio whii-hibc
Fi^ki' Ftiiid I'rm wu KW&rdeil, July Ht lt>t>L In •>»■: ■mall ucl»vo vutuaic, 6^ pagM, cxlr*

MONTOOMERY IW. F.l, M. D., M. R. I. A., tc,

.prnfeiBrit ,•! Midwifery iu llie K iiiit and i^Hceb'a Cotlece '>f rhrilrianlici lidand.ftg.

AN EXI-OSITION OF THE SIGNS AND SYMITO.MS OF PREGKANCT.

Will) hotne vtUei Pancra on Sii)ipriaoonnan«d wiih Midwil^ry. b*mm thaBaooad and eolarged
EiiKli'h filiiinn. Wiih luro viqiiKiie aiii>r«l plnlea, oad uiiinerDUi wiird^uU. In oaa very
handBome ixMavo votiunv, «ttrB nlulh, of nearly 000 fmgvt. (LatrJf PvUitiud.) %S 7S.
A ti<M>li uEuauHlly rieh In praetiral aucfeatiuua, — fraab, and tIroou*. and elaaaiea! la oar nathM'a
^n JoBiKal ikfid. Stvnt.tt,i»ti. \Xi1. | airle ; and "iie Torgria, in the trnvwvd ohaim nl

TficM aeveral tnh)eota lo later
valvea, and au Irnpcriaiil, erery one
moBl delioataand prccioDa lA avcul
Imlllni vflan tt>« hnniir and dnineillc |<«ee
ranuly, Ihe leaiilniBer of ntfipr.

Fiareci, are all Lreattd with as
iilori* of illuilrat«i>Ba,ariit*uei««u.ii ii.«Mii- 1.1 It"- ^ . - ■ ■ _ -.,.".» i j

»»au«.»npar«Ualed.Bib.i.(tk.,aJ.d««.rp«,adU,^gP'M^"-r,''«'^v"^^^

irine <> r the If fe iif I U P-ia'* eonnceted with piegnaney, lo be ev«rywh«ra
D elVwi-' of dteliwi, '«*iv<d aa a iTMnaal of «p«etal ja.i.j..Bdeuee. al
uri.aQdiiiiliecufrea- "nee i.iinnuq--,n| f.ei.ajnr.hnu argdmeiil. raUbliah-

MOHR (FRANCIS), PH. D., AND REDWOOD iTHCOPHILUS).

I*RACT1CAL PIlAilMACr. Comprisiag the ArmngcmcnU, AppaMtas, tad
ManipulaiKMAof iba PtaKnnBMVlicftl 9tu» and Lnwrstorjr. Kdiicd, wilfc«ste«alT« AiMitlona,
by Pf>H. William P«oot«i. of ih* Pbitnddphin Coltege of Phafmaay, In om hai«|anniel7
pniil«d4iei«varotiUMtUtrncltflb,<»l 070 pafva, witkowrSUtviH^nivuic^unwwyi. VLt%.

BLANCHARD ft LEA'S MEDICAL

NEILL (JOHN), M. O.,

Batf •« Intlie PcBnajlvmnu. naqtlul,AC-j aad

FRANCIS GURNEY SMITH, M. D.,
ProfM*«i t^ Inilituir* i>r MfCicmc ui Uc I'tnfiiyh'aiiik Medioil CaU((*.

AN ANALYTICAL COMPEMDIUM OF THE VAKIOtTS BRANCI

OP MEDtOAL i^CIENCE ; (m the ITu and KxBminmnnti r>r SKidimtx. A mw ««lliWa, rvril
mnd improTed- In *">" ""'J Inif^ *ni ItaiidMicnL-ly priiiW royal ISnio. voIuiim, DfUMiil i
Uuiusaiiil |MB«*< wllh 374 wruod-cut*. tilmiif ly bouoil id Inalbnr, wilh r«iM^cI buida. $1 1~
The vttrj BartirrinK rvceplinn which ha* br^n krcxvilrd to ilii> worli, aBil \tte hijcti r'tlmi
Upon H by iFie profpMion. •■ «ri(i(*<) by Ihe cnnxUtni util infivtt'iiif it««Mnd whrrJi hii> rt^
haiiML^il iwolftrgceditionsttivaMiflianuKl llieKUttaon> h> render iherolunMio tUpmcatl
mr>rf wonhy al Ibe uiooeM w&ick hw Utendvd it. h bu ^otmnSmf^ been tboraucUf e
ftiid siii^h erron aa hail an rornwr oc«uiaiiiMCft|iodoh*vrvatu»n twrabeea eorraoiM.SMV
addtiii^iu WMC iiecosHir)r to nwintnio it on >Wel wjlJi ihe viymmeeoi hWocb hare bc«n Bit
The cxrmdcd ■•rle' oriUumtvitDnii li«* be«n Mill I'linher iueremtei tod much improvttd. <
■ ilicht vBlarcemenl of xbx pnge, thew TarioiK ajJiliiiviu bare been ineorpomml wiihoat i
(he hulk of the voWm*.

Th<?wi>rbf>,t^«>i«''or».R|t«tDnnuMTnied«*«mtnBnlly worthy of (hvlhvorwMbwhioh ttbMbij
hnrn ri><H<iml. Aa « bonk Tiir dally reference by Ibn alDdnu Mi^uirinBafpttfciM hia mu**) '
tm>-hik>, an a miitiiiBl for prrccplor* dnirin^ lo ttiinulala iheir niiidiinl* by frvqwal kkIi
ttxaniinulion.oratavuurof frciri wliiHi the pra^lilioitemol (Jdtrrdalcdnynuiljr andcbcBpljr^
fe knciwlrdre oflhc dtuigeaanit iniprovcnient in proleaaiaual *cieiioe, tl* repnlattoo i» pemutrnSf
«atnbli*hcil.

Th« hen wr^rt of Uie kied wifk wbl«h w« ate
aequnlntMl. — Itftrf. F>ainfa«f.

Havtim iBad« fere ute uf Ibli v<iluni« In oar rx-
aailnaUiioi *>( |iup]U, wc riin (prak rmm ripril-
aac«lB r«e<>nni«ncllag il aj an ndtninible vompcD']
frir (lii'lni'*, Hnil k« r»(*rUIIy mrful tii titer rpi.ir*
whi> eXHinliK! lY.eir piirllf > If Will nrc the tcaehet
mui'h [■<»'[ li[ rnalilInK him mililv l-> r'?>-all ill t>l
th< piiiaU Bpi>ci whini bii pupila ihoal'l Ik ci-
amioril. A wmt iif tliii xirt i?>i>ulil 'x' in Ibc lianJi
Of «V«n' ivii^ who t(ili<-B pUfiila in[i,> hi* nflic« Hrilb a
vt«w iq uominlPR thrrn ; anit tbit itaai(U'HirDtHblv
UebeatoriUrlaaa.— TVaKiytvaauHt^ Jourutt.

Id tho rapid Doutae vt laalar^ wbora wwrk far

UicitttdnU la baavTiaad m1«w mntmmnb

«jiaiiiiu*iii>n, a C4iit)pcad ia aot only valaalila,
U I* HiniiMi a Hia* 4a« aaa. Tba ana f

m in»(i of ihr diVKlLin*. tha moat Da*.
of all InH>l[i i>r Lh« kiDil thai We kSoW
Diwrii and aiiiiailxil diclnaaa aad ika
nii'VPincota aud diKArehea are oialirtU]
fpuciirty, Uid b«f«r< Ui< alu4aMt. Than

lourhijuiw^'"^'- -iii.'^r--i f.*"**f»hi ii.k4

■■ wi-rtfi II'.

atra in ini-:l

who imvf 111 . — ;.. ,-^ .

prrba|»fiacl nvlCxim ii ihaiib* arieBTBtaant^
onw What ll waa Wbca IbCf l«(l II •M.—TU BtM*-

"^ zii

NELIQAN (J. MOOAE^ M.D., M. R. I.A., tt^w^ •* ^

ATLAS OF CUTANKOUS DISKASK^. In one bcnutiful quarto Tohtma,
cloth, with KplcMlid cotttrcd piatee, pteaentm; nearly oa« hmdrerf elaborate reptvaeaitfiuw tf
diacKM. %\ SO.

Tbi* beautiful rolume i* ioiradDd m • eonipl«l4 and accurate KfmteatuioD ol all Ibe
of Divuxr-^ot theSbin. While ii nan bo caniitll«d in cwnjutHtiMi With aiiy wgrt bo Practttw.il
F«pori«l rr-frrvae* hi ih»atiihur'**>Trvaii«(rnii Dtantsw of tho dhiti," ro lavoraUy r«eei«wd h^
profFKHinn *mav' yrara linrw. Thv publt'hf'n) tr*\ juMilied in Teyirtft ihal fcw mora beaMlMty
ctitml ptiiic have ever hrvn pM^Miittrd w (hi? pmfpwioi] <if ihia mMTry-

NrliKAii'* Alloa nt ITulanr^m Uiaraara auiirtira a
Inaa «ii*ipiii lira i(lfr« III m •niicn 'fIi n\ ihc largFti
claaa rtf oiir jirivrraaing . It pr^arnla, In niiarl" ajEri
]4 rlaip*, ndi eontainlBs rtnm 3 tv 0 Afurva, anit
f(>riaiD| in all a l"lal of t«l i!iatini-f trpftM-tiliti-im
of tha dillcteQi tppcm of akin aS^rtliiDi, irour^
Initrlbri in irntta nt Camiliva Tli« iliiiiliatiMna
havs brcii IaWh friMn nalorv, inJ liars Trcn roi^K-d
Wilh ID eh £>JrHt/ that tlipy preanDI aatrikinf pilciorn

«f ttfa; IB wMen the raducad icaaa apily acri-ea lo

icive, at a (dhjb i'ail, Ihs rtanarkalite
of fliQti UilVHlaiil varwiT, And wbtlfihii
mae » rriulBrHt iBura ilf«aahl«. ikf re
or propiitl'-n icrarred by Iba anraaaary ata
Iiun. Riicli flf nrr la blj|Bly ooIortO, and Hi uaC
h.il thcartlal hfia Ihiil (he mntt Taalid una ubMr
pooIJ BBI junly Ink" "irrpit'in fo tka mrtM-WPB
tli« fliMuiiiia of iM' nifiiirca adder bia MralMla
HfMKaol tf4. CkrtuU. ^

Vt Tma ajiMK atrrnoR.

A PRACnOAL TRKATISE ON DISKASKS OF THK SKIN.

ASKfiicnn edition. In nno acal royal Vitao. Vulatne, eilra cloth, ol 3!H pef^a. St 00.

1^ Tbo two toIohms will be sent b7 mul on receipt of Fiot DoSart.

OWKN (l« TITB DIPFERKNT FORMS OF I
rUK HKBUCTON, hHU (IP THK TKBTH. |

Oaa wil. rayal Itinfl , extta OlOtk Witt
UluawaUoai. •! M

PIRRIE (WILLIAM), F. A. 8. C,

Vnftwetof Sanrety la tM tialTeraity «f Al^Mwa.

THE PRINGIPLE3 AND PRACTICK OF SITRGKRV. Edited bv X

NaiLi., M. D., ProfeaaororSnr^ryln ihePmna Mpiitiiil CvltecViSttryton lulhePrnn»rK
Hn*pital,&c. Iuc»aireryhandaoiii«or(an>T<i^uiue,)eather, olTsOpafaii, wtih SlSilltutru

W? (MOW of no other aarcfd ^mt M a reaaoo- ' Ta(ely diaeaBnl IIm p[to«l]rf» of aari*^ , aa< a
■Me aixTi, wScrein ibarvlaao«ei:b ilMvitya*dpnui> I lafe aail tT" IiitI [rarllrt pridlaalad a^ia ~
MM,»r whereanbleeu are awraaeaadly or alaetly i PrrhaaiBa work apon lhiaauh|MChar««i>/inaJ
laafht.— riitSuaai(«ra, la aa/allvMa lb< aelenoe of tkaanof aairf

ffo*. Pinle, In Ua wart balo** »»,**» d^»».\K**»«|«*i^» »•»""'«/ •'•'"<•*< •«>««»»'■.

Airi> BOIEKTiriO PUBttlCATIQIIV.

PARRISH (EDWARD),

LottdrtTfl* P not leal PhamiiiCT anti .Murria Mcli^i in ihr rpnD«yl<raaU AoRikia]' (if M»41ciar,A«.

AN INTKODUCTIOS TO ?KACTICAL FnAltMACI. DcaigMcI m • Toxt-

fiooh lor lli« Sludeul, and a# • Giiit3r lor ih« rhy>iftiftn ud Clwmaonniiel. IVitb mm»f Por-
g)u!« uid PraMri|>iiiMi». !5«MM)nd criiiioii, grc*ay onlftr^d uhI unprovvd. In <mm hmiulMine
<K-rnvo rolunie of TJO pfd wUfa tevetftl hundnd llltutrailM», uira dalk. $3 90. {Jtut

Thai V.A<ntA Tarriili, in wtUiuir a tjnuk npaxi
l-raiitiol fhnrmOfy tntni friV yr4fa ntn— I'tie rinJ-
iwalij ufi^inal ■titl 'jBiqDP--4ul th* nrdii-ul ami
plwrnuocalical lirn/caunmBR'ru' nnil Tulyalilcari-
VtM, no ■WP. wp mint, wn" Ivii liml o'-v^ii i>> Id
« will ili-ny ; dmililr wniciirt"-, thco, i< mn O'w
Wp, cowmlrit iHe nililwt rniiln <it nit iri:«n
ni:li rlpcri<^<:« ■> aa iihifrvrt, u-arljrr, aiLiI
..t1i> il DiiFtalorlD tllri>hiirni.i>'--iiliciil la In 'r4 lory.
« cjcpIIiibi plan u< tlie trH ii mure [lirirnonlily,

BiidiiiArtaii.aHrnnioailBikUMiiKiB.— i*fliiiHtiJ«r
M*d. jMntul, Jut. IMO.
or Murw, *ll apetluwrm wh" tsve Bit tlrMdy

■.CopTof the BitteditioD will piururr luie of Ihl*i
tlla,lh«TilnT<,lophyi1olBiisrnhltu( tn the ciiuhliv
■nd tn amall Urwva, whu cunmit ck-ai! itieaiirivf* of
Ua akill of aa educated |tliatinni?«uliit, Itiat wc

we*, I

Tfc«e

1/rill CdiI all Itiat \.\\*y Atmn to keitw, and Umnlt^
knnw. buE rery iitu« cf whieli Ihrr dwiralj^ tnoi
in rpfvmra Lii inia iiari-iitlBal pnlaalenl hnovh
tliair plofcMiiin; lot il La a writ malillahnl Fact,
Ibnl, ID III* ■■■!a<^ii'>o "t pliyiiriiiii, wliilr ll>e ael*
•rnco i>( mrJicliiB i( scariall)- wi-il tanflil, »oiy
tiillF atlFnli-n la ]nt4 lu ihe arl 'if prqiannf llirq^j,
it^i MW-, Bii<1 wn hnipin^ nil ru'vr lint ^Infrrl cnn he i
well rciDHlied ai ty proearing anti cnnaulliuc Ot^
PaTiiah*aBXOBlle«l wiMk— 5f. Lowit Mid. J/ntruat!
Jan. IBM.

Wr know nf no woik nn Ihc aiitOfct which woiilff '
he OKire inJiipeiiuble Ui Ihe phyiicim nr ituiltnt
d<ai'liiit in^iiinaTi'iniin Ihciulijri'i i.if whiph il ircnia.
Willi (jrirhifi'i" Molicil F'>rinalnrY"aiid liila, Ui«
praeliaiDg! pltyaLtriau wiKild Ii* auiijilivil M-iili iiparly
»r Qllit^ ull tlrr oinrl uttful lofol nation <■□ Ihf^ >ul>-

Woald ta^Holally comiiuad tliia wurk. Ill il lh>y Jtol. — Ctarliiidii JkCiJ. /oar.aiaW Aai'ttW, Jiici. loGU.

PEASLEC (E. R.», M. 0.,

Prthfeaaoi nr Pbyaiolocy Mi Gtaeial Pklbat>^cr U the N«w York Medical CJiUtf a.

HTI3IAK BISTOLOGT, in iw relaliona to Anitomj, Physiology, ud Pathology

fur ttia U*« 9rM*ilioBt9iw4eni«. Wiih Tout liunilnd oiid iliiity-lour itloalratlana. In ova hand

•onta oolBTo vtJitme, of over 600 p«!fe/. ( tfUrlif J'uUitktd. ) S3 75.

It emtfiacra a lilirary uimc llie tonio illaf aaaod i Wa wuald rccomiDPud it to the nedlcal atudcnl
Within Ittrlf.iuo It jutiwliallhc [eiii.-li(-raailkarDer | Midpra<:i<iioo<r,Hic<ii:itaiQingaavniiaBry urxll Itiat
aeed. Jlouli.er advaatagr, 6)- no muo> m be nttt- i* knuwu L^f llip luipvivitanl auli^Ca wliipfi il ttraia 1

lootMl.avctjrllilDK or tcarvalacUi Itifl widfl rar«e
which It emliiac*. la wllb frax >kill ruinpTraaBit
IBM aa ooiaro vn-lvrn* of trui little iDitre ihaa nx

kBudleil [■>■«. Wp hav* li<-( Miily lb« wbiila «ul>-
le«t of filalii|n(y. iDtercaliitf in llarll.atily and lull)'
diacaaawl, liui wliai II III iiiTmilTly gctvi'i itil*'*at
tti Ike aludml, liecauM lA criattor iiiadlTal valae,
■ ni iu coUuijua to Aiwt'.'niy, ftoyiiuluityt and Pa-
UolOf r> vlilcti arc kef* rally sad miaTHrlarily aol
fartb— AotAnii* Jawnt.e/ Jff4.«iirfAarcwr7.

or all that !■ eomatiinJ m ilie srcat w«>rki .>( Sim.ia
and LphinaaD, aiiil t>>t o'piiii? chf^miiti In Kriirral.
MaaMr lhlaAa«v>>lump.wnW'.'UlOau)- idhe nnJIcal
aiudaut and pia>-liiioiiei— oiailer lliia l»>»k bi>iI y<i«
Itauw all liial ia keou-o -uf Ibo (trsal (DndauicniaJ
IKiiirliil-na i-r mKlivine, and wn have li" liriiultna
la aayinf that it la aa hoiMif lo ttie Amnltcmi iiirdi-
Cul pn-frjaiiiD Itial oiir uf IU ■ii'inlipta iIkiiiM have
piuiuecd It— at. L«a» Af(4. OjM fars, JvanaaJ.

;%,

PARKER (LANOaTON),

Buigeim lo Itit C|u«>n'a Uoapilal, iliriaiaghaM.

THE MODERN TRKATMENT OF SYPHILITIC U18EA8BS, BOTH VJtl-

MvVKV AND i^ECUNUAKV; i-uuiniiBiiutifai:<Tri.ieiiiitiilurCuuMituiH«al uidCiMiiimi<<l Syi.lii-
jia, by a eulo and eiiocveslul laeilkuo. With iiLiracioiuCaw^, Furmulia, Bod CllniCBl (Aitcrva-
tioos. From tli« Third anJ viiurely rcvrrittea Lvadon etliLion. la one noat ouiaTo TollUMf
extnotoili, ol316pDCM. tl f^-

ROYLR'S MATERIA MEDIOA AND THERAPETTTIC8: induding th«

Pr«p«raiiu)iii ul iti« rhariiiBpDKi'iaii of London, Edtnliurah, Dublin, Biiil uf lti« Uuitcd SuiAa.
Wiihmuiy aow OMdiainRa. Ediiad by JoserM Camoh, M. D- ViriihaiDeiy-«)ghli!Iutinuotta.
to oneUrgvociavoiroluina.cxiTBcloib.ofBbouiTOO pevoa. t3 00.

ROKtTANSKY

Comoi or Ihe Iinprrtnl Patiiutosiral MiiiKUm.

A MANUAL OF PATHOLOGICAL

boBfid in two. e^Llra rluili, »1 atuui VJM wee.

KIR*, a. U. MoOKK.aadO. E. Day. K SO.

Ttiain»reiai«tiliH«»W»llaoquniBtecl Willi ihcce-
pntnlinDor HokilaBifcy'a wofk lo need oor aaaur-
hlxto Ibal thi* l«one uf the nHialixofi'Liid. liK.Munh.
and Talnable brmka rvar iaauril ikioi liie intdinil
preaa. Il la lat Ktiufif .BDObai nwr; lU' vriUi ila
else «lld pT«Mrtratl<^n, and ila aa]n fiilliiwa aa a
mattal of QU'iiiae. M» libmy run lis coiled eook-
plolc W.thcnt II £itfai# tt*4. /(arwat.

All aurmiii i" (ivo ■>iir i«ad«ra any adtqnal* Idea
«r tbo vnat amuuDl <rf loatinvlhin acruiiiulawri la

ICARLI, M.D.,

anij I*lornaui al the UniVtmly of VIeilU, ht.

ANATOMY. Pour Tolumea, oobTO,

TraoAlkied by W. K. Swawb, £i>w*bi> iAtmrw

IhrMfnlDniaa, would VrMbte end bop«li<M. Tfc*
fitort uf the iIitlMiguidird autboi In eoncwiilrale

In all apuvr hii (itai rant] or kauWlMJcr, baa

aaaaQatfoi iiu ie:ai witu raiaaOla truibi, it,ai aii*
attempt ol a rrviewet lo «pit»niii« la at mrr para-
lyaedialid itiual anil in a I'ailure.— Wtilfrn LnuK,
Aj Ull* I* till' biiiiMt emiree of kaowlrdftc upoa
the impiirnni •iiljjfrl .)f wineb It lieun, iii> leal
■lad«ni Can ajlijtii u> (•« wilhiiul il. Tlir Aiaeiiean
paUialicr»BB*a*uillI*>l [fieintrlvti u ilie ilii.iht ^.-i
thapn>(ewi<>D tfria*iT ettunlry. fm lA liiiioiki and
baaullfulpditlm. — HmtKmHi Jaaraal »/ MiJiciaa.

I UN

RIOBY (EDWARD), M. D.,

Ik-alot Fhyiiriaa to Ito Uraetal Lyia|.ia Ui-ipital, ko.

A SYSTEM OF MlDWlKilKY. With Not«« und Additionil IliQBtralioM.i

Beoood Americen Ediiiun. Una volume ociavo, Mira clutb, A'Xi pB|«a. S3 90.

BT THB MMa ADTIOB. {Laltif Put!iikt4,)

ON THE CONSTITUTIONAL TREATMENT OF FRMK\& \i\K%.fc&^

J«ODcii«Biror^ J3ni«.*oliun«, exira clolb, of aboM^l:!)!! fa^ea. V Vk.

BLAMCHARP k LEA'S MEDTCAL

RAMSaOTHAU (FRANCIS H.), M.D.

TITB PHINCIPLia AND I'KACTICK 01' OBSTKTRIC MEDICDOC Al

SL'liniCK V, U) rprercm-T' to iht Prutrf" of I'uTluriNun. A uew aivd Hiliufet) cdilicm, Uuwouglil
Ti^vivrlbylbrAutbur. With Adittl inn n lif W. V. KKAriNci.M V , i'mfcMor of ObMetnri.Vr , i
thi- jFlTcrMin Medical Col If^. PItilnikilphia, In oiw lurgrnnil ti«ud«t.>iuc irujiertii] uclart>tL:i!(ji:
otbSU piifci>. Flroanily bound in Icaihrr, with ralivil bnndf; willi (>isi)' fow bc«iitirw) Ptairt. i
Bmnoroiw Wood-cuiii in lite text. cMiniainii^ in all iicarly 3H) Urve ud tiMUlilul fi(um. $^ I

fVdgn Prn/ Ht^ft, of ikt UaJMfiii) ■/ Fa,
To Iba American pnblie, it la mnalraluaMe, rriim ltd Inlrtnite m»«onhtea ueallaaM, 9Mt U htv
UtebedBaibuitirdeiiHMMttor^filtatilUulwil'vry. ItiFimiJBUua will, 1 liii»l, liiiiiliBafni I
OBTCiniatrjr.

llliDB(i>'aurTio«*F*iirtl>l>4 In ray >nl toiht tnty <Ir|t«Bi airle la wbick ili«]r fcav* hri>«||Iil

■ llhly 111 ilii* wnrk. It i*i]iMdyiipprt<-iBt«l is uol
C^XIAt'T l~"* ^'"' I'A^iA^ i^f ttiv iiiultKr, tlif <il«itrli'*u <>f
it! Blrlc. aaj Uie rulticiiof ila lUuiliilinn* T» <lir
pbywirian'a libnir)' ii mnilKOriii-itM^', tirliil« lu ihr
■luilriil mi ■ Iral-lM-ukj fioin wliirli In riliaol Ike
matrriiil fir iHjtrif iht |iiaDil*ilrii)MraaeitDrDlivn<rii
obatririrHl ai-irurr, ii liai mi «u|iriiiii.— OAia M*d
§md Surg. Jautnal.

Tlie publialiera bava aaeured lla aueccaa fcjr Uia

■lUI, cscdllaf Ibcai

dally imu ptiiea.

>c«wRlvea la lU pioahtr-i<iB
II la tlrdicaM i'
■ail baa Ui« amphalir cbiIh (arm's i -il
U Ibe beat axpaatnt «[ BntKh Y
kn- w ofii-i Icxt'bwik wbirh d->-
Ui L-i; Dirtc t>if [aiy' rerWLciifiiiOr<'

COUlll Willi (•'•CBillllUlC^Ukll. .

for tliey vrtU Had il tivalHaUe [0( i'
Oaatdt.

RICORO (P.I, M.D.

A THEATISE ok the ^^NEREAL riSKASE. By John Hmoxa, P. R.S.

WiihcoptoiuAdJilion*, bj-pH tlirojin, M D- TrHnxlaii^ niid Edited. Wit b NoIp*, '-> *'"•
1. BujfSTEA&. M-D , [..roliirrr on Vmcrenl at Iti«CoIl<f|«orPliysivrNnaHNl8ar|fK'i -
Sevcaid rttilicii), reviatul, c<nilaitiiuf; a rcxin^ oi Kmms'a ItscRHr LuCTCm OK ■- .
onotuindiUDte octavo vultmn, txUa cloth, olAfiD pugck, W(lli«l(Fhl|ilaiea. $3U. {Ju/i it.

In ravisioft tbt* vrorh, ihe «dliar bus etidrsvoi«d la iain>clu«« wbal«>vm Biatt«f of lnttrr«*l tie
iDi iDveaii^iims of BypJgdugtaphera bave adiJed lo otic knaarledga q( ilti- •iilijf><:(. Tli«
aourcefrum wbicli lbi> haabniu derivwd ialiw Tolimeor'*LiDe(itr«kon Cbun.rM, " puUi
mimtlia tuie* by M. Ricord, whicb allord* r taiwc lunouKtof ncwaud aiBinniivp naicna
OOflUoverlrd pomia. In ih«! pfcvinoa iNliiioii. M Kioird'i a>l>ltiiiwit anioiniltMl loaeatly inp-l
of tfarwbule, and wlib ibe Bnit«r now liiirodui-*^, ibe w.vk may be ecwuuktrd lopiwni tu*r>
SDd uperircoe mora HuifoU^Uy aitil c«inpleti>ly lAui atiy oiber.

Rver)r onr will rtoofull* the ailrnrliTEnrii aiul

talui) wtiiPh ihla wofb dartvca nwn lAur pn-ten'ini

iwarfiurlaa. ao(nathn«<> a<«rcidil*d aad aanrtHftM I.
In IM nolcato llunirr. II>f mai^ri aglivtitatn hi
u<l«urliiaiBI<>r|>rr'iFn,iii>dfrivtv bi*M<|> miniHtlklt
M ilie wotid III ■ liinidsnil \triirrMy iiwW.t \.\r mao-
in-f. in r''>i^i;lH*i(m »■* pan aaf laal Ih.* li Uic
leatalily llic InMtrraiKc on •>plitl(a wiia wbirfal
am ■i-i|uiiii>l>*il, and, ■> wr do nm ntirn iiaftaf I

Ihanptoliiiiaar lUeae Kfomaaier* ■■del>)r side. Vai,
II niuil lie admiiied, wbitl Aa« made ibo fbrrnne o/
thv buok, '• ibr fan Ibai li canuiii* tine " nraat i^«ni>

^Irir rmt'otliiBciii af lUe *eriiat>tr dacKinva trf luc
ftpiial ihi Mull," wliJori liM rTi-i b'^n mail-* pulilir,

Th« doctriiial lilirBi ol M. R/rard, idvar whxn. if nsi \ phraiw.. wi- may Nr '■<'H><*d («f Ttpit»*\nf I'lx
■nlveraally adaint-d.air tiininii^ialii] doiamani. ban* i ilmi ri nay Diiii a {iIbcr ta iIm lilmrv af pvctr
h«roM£Mcoiilyl>reni7it«rprel'«db)'inattorleu.>kilfttl jvcian,— riictitia AI<d. and 8w«. Jaurnat.

BT TBI tAMi amox.
RICORP'S LETTERS ON SYPH ILIS, TranBlatcd by W. P. LAmMonr, M.j

in one neat ocuvo volume, of 270 paioH, exita cloib. ii 00.

SMITH [HENRY H.I, M. O., AND HORNER (WILLIAM C), M. O.
AN ANAT0MI(;AI- ATLAS. illustmriTe of the Stmctnre of tli« flamuj IW?.

In mie volume, lor^ iinpcrial wcUro, extra doiti, wiUi about ais liuodml and iflr bCIMital
figiim. »3 00. '

TbOK team ara wall talanud, asd fKaul ■
•i>in]tlelf aiiil Brrarnle trpreacalallioi of Inal wtm-
derfal (BtiTi«.IU« hamaa botfy The ptan nf IHia
AtJaa, vliirli rroilera |1 a» prruliad)! ciiurpnimi
for theiluilrjit, BBtf ita aaperb aniaiicul eatcaiiua,
tare iKvecBlrtadf polalod out. Wamoai raDgialu-

bUe Uu (tndeni afi«« the BMOiilaUMi a( ui* AUaa.
ai il la the iniMl cuarrnlu.! woik of lb* kind Ikal
bajyclBitfiiart^: and vrt mail add. UemrbaaB.
lifalnaaim iawhinklt li ■■■sl«r* t*an«i«|ii "
V> lb* e»iiBUr U to b< flalUtiu la oat
pride— Aim r^oaa lt**Uai J»vf*t.

SHARPEV (WILLIAMI, M. 0., JONES QUAIN, M.O., AND
RICHARD QUAIN, F. R. 8., &c.

HUMAN ANATOMY. Rerised, whh Notes uul AdJition», by Joetpa hmipT,

M. D., Profeaaor ol Anatomy ta Ibe tlairorBity of P«nnsylvaiii«. Complcie la IW0 lun aclif« '

i«iimii_i

Volumf*, la*tber,ul' about lhirtc«a bundrcd paf ca.
angnvingAB'

food, te UO.

HaaaiiAillyilliiatmcil irllli mwlftkaBdrvl

•OLLTONTHEHVMaN BRAIN; It! f<ttiMtaf«,l
PbyilsUvVi aad DiaeaaBa Pr-.n Ibe ^rcirad aad
■meb ><Dlar|ci>d Londoa FdlluMi ■■ iwr •■ctavv
«i4BMir,)<iltaelwtb,«riMpa4«a, With liU wiiod- '.
flflla. IT 00.

BKMVf UPERATIVBHUR6BBV. U aa« fan '

budainna oetarti Toliaia, cAlia elnik. af nvar ■■•
page*, wiU abuat ub* taadrad waod-««la B3«
IIMON > ut^NkA^ti. J>ATtIUlAJOV, t- iiawtat-
tyr U> Ibe UaubJian».nl uTRallM^ Pnatiah*
(a* Ibi pMvaaUiiB ana Care a4 Dtanaa la gat
i)(UTu«ala«*,»xtl>el<>tb,of«U^a|Ba. •til.

AMD 8CIENTIPI0 PUBLICATIOMS.

8TILLE (ALFREDI, M. D.
THEIlAPEUTtCS AND MATERIA MKniCA; » SjuKmntio TraHiNs on ttia

A''t)irii Olid V*r* of Mr^tinnBl A^it<, inctixlinx Ih<-ii UeM!ripii<i» and lllslaiy. In |Wu Urg«
mid tiNnd*i»>c oruvo valiiion, ot 17KI pagvi- iJfjl Itsued.) SS 00.

Tlii* wur Ic U ife«ifne4 ««)>Nliittir ftwilM tladenl and pncf llMfwr ofmedlcina. Mil IKOI* th« VKrjam
triKtesof ihaMi)i«nii Mmlira from iIm p^itm of view ol' ibe tmbldv, Mid not ol ih« nDopor ol tM
iDPiB/v-rovm. Wbih ihii* rmkavuMnc m f-wv >ll pmi-ikal iifbnnitioB Iitwlv to be SHrfUl witl
rv*tw«iii'<li«Mnplwyme<tiof ■I)?!-!*! ririni-ilHft in >pi^.-ial atvi^liiin*. and ih«ro«nli* lolwQtttk'ipnied']
Iruiii ibvir odniintHrBl'uA, a cv|>i>>ii» Inila'i i>i DiM>«Mr* «iul iWii Uvnu-itRr* rvnder* ihv work <*iaj>T
n«HII]r fllluHl Usr r*{ftr»r» hy ■hiiwiiig al a (ilaiirv iha diAirmii ai»aiM wliii*!) Iiav0 Iwvn «iti(>iov^i
and iMdliiiiio it>r prBriiii.incr tA riieiid hi* reMAiraea in dil6cuJt oa^vf wiUi all ibot ifeo M|<mwia»
or tlw ptur<!ii*ioii h«« ■iiggeitcLl.

Ranir, ladwd, ban v« >i«i) (ubfnnird m ai a
wuik on metII«ioe>D pnnrfFrnat iu In c)|[iirn*l<-ii*
■■ that sow b«for« ai| an fnaeicktiiif tn lU '

enatrali. It ll, ifcrrrfaie, Willi ii )<><]Ullar giKtin- :
eallua l]i*l W* r'<o(niic m Dr. (■illlc Lli« p<>4i>t*- I
■ion »r niiiny ortliitar inurF diinncuiiiiird !|iiBliiIiLi- |
lliMM wlil^h mliTk hirn i» nptit'il>aiii>n, iid<I whicli :
jnaliry hiiri rn e-'miiif ln-fom I'la m"lLfal l.inncn ,
■a in laaliBiiliir. A compfirbPiiiife ku<iwlc<tKr,

■cal«4 by • ■«un-l aii<l p'Rvlmlin^ jiii1t<n>al, J *•■ ,

Vi ■ Inrenf v"'*""" whitli ■ ulirimnaiiliiit apitil i
■>r Isqalrjr hm tFta|r*rml lo n* d'arrriii w^ntt-t "'w
ItrraiiB'^ if la nrv, aitil aLaijilut^ n-ilhiuff I'W' \ir\-Aii%e
tl tanld.l-ui wtucAntimaici ciilipr Bri*->tiibg| i>> iti j
trlallena 'n ■ jaal l«g>r und •'it'*''"'"''*'-*-""""'^'''!* <
|la»l''«r«Trwkct«.aB4iiir« tuib* guiLUqcorf Ifce
aialhin' all 'ke aaniraiiro nf a*rr(f whirh itir iliA I
ealuai'if hja ■nbjeel can allow, la c<ia.:ia«ii<n, wa i
raniiutlr ailviaii nur mdpT* Ii aa<->>:aiii foe ilirm-
aclvea, bv • atuily at Ur !Siill»'a VfUmna, llif crnai |
*alaa aad iciaiui ur me aiornvr kNi'Wip<>||e \Uxi \
pnattit. Vir bavc pleaaorr la tcfrtrioa oilirr tu .
thvamptf t'Miury "t nndouljicd iruthi, the m\ anil
oaaartd conqiiral cuf mcdicinr, aciumjUtrd L'V Hi. I
8ltll« IB 111* p*f f • i ani> pi'iiKiirn'^l ibe itim •'( In* la-
l»i]ta Iu chp ait€^Dihiit ^jf oar rcaclrra, aa ulikp bnavir-
abl* ti> tint MieDCe, aad crrdilabk to IhftMl.lka
raairti. anil tiia (udttmral a( bin who Ku garneia]
Uiawbolc ae axtvta\\j.Siiiti*'K^ Mti.Jowrmtl,

Our sipntaliMao/ Iba valna M Ihia wi>>k ware
baaed oa (ha weU>tDaw» Trpatailon and aiiaravirr
of fh«aalh>r aaa man of acbnlarlir ■Itatniiirut*. an
•lanM writer, a «mn4td Inqairar afin nalh, aed ■

thuaaofriticalltaiahcri we koFWikai ihaUak uroald
* MHdttlillfiBalir p«r(orni*4. and >l>ui (rw, tl any,
•mofif ibc dlRlia^a illicit ax^ira) trirhrri io mil
CWBtfr *<* Mller qaalitrd ilMn le in prepar* a
■faicnalle trnliae no llieiapralica in accirdaiioe
wilb tb« pr«*«oi r^iili«ni'wta i-f nndlcal Mltn^*.
0«r prclimlaaryrxaniiiiatiuauf tL« work liaanua*

flr4 u« that we were irnt mlRakn In our anlKlpt
li'iiu— A'tw OrdiiHi UtJital tVtai, Maieli, tsW.

The ■«'■■( reveat anllidnty ia th< oar laat ni«a*
tineint, Sull*, )tia (ml work I'a '' Msiriia MmJI* J
oa uad TarratKuUea," ^Ublufeed liii >,(alira'
iwiairu vi'lnni'*. b{ aiimc aisteen bunilCBiI pajna, J
wnilc It EiDba^lira Iha rcaulia of Ike Ulor vt «UaMl
up 1(1 tllp liiuo uf pabtieatioa, la cdiicIiaI wilk ftl
fttu anouDI or oriciaal i^haerraUiitt and rfiM>*f«lhl
Wb wnuM draw ■UBntiua, bj Iha wa)r, t-i.tna raffl
^I'-nvrnlifit ni'>df id wbicA tlia lit44i i«arr«uad uj
lliia wurk, Tlitrr i« flraiaa " ladBZuC Rvaindlaa ;'
nrzt BD "Indca of UiaMtaaand lh«il Rencdiea.'*'J
Hueb an arrnn^'mral n( Ihe ladlnna, tn am i>pini<iB| <

trruuy rutiiam IhepracLioil ralufl iif buikauf lki«*
tnd. la l>iliiiu«, ohiitsal* raaaa nf dlCMiia, wliera ^
we have l-) Irj' 'me ieiiinI|F afirr aaiil'ini unlit •■
tU'VX la iiT'tty nimrly caMUil*^, and wr arr ilaiiial
driven U> iJUf wit^i end, Bur S an iniEoi mirir •'(mad
of tlie IWO )n>t iBtDltoiied, i« rrecnelr what W*
Waal ~l.itmJau tint. Ttmn»n4 li a clu, A[-ril, l>al|.<

U'f ihlsk thti WT>tk witl doMoeh to uliriite itic
(eliintanertn a IhurDugh laraatif aiuinirf t!il*bran'l|
nf iitimXi&r iiuily, {:•! In tbe wida rui|c •>( laniiflalj
UlarBittfa treaaiirdi in Ik* FtanllBn tiKfi||ua, w» Bball j
bnrdlr bad a wurk wriiie* ta a *iirle mrire olMr aafi
(iin,il*,ct'D vying (oiriUif lh« fnc-U tBn(;li1, and yat
frae ftitn tui«ldtlrali4 rMuadancr. l'li«re lea taa*
«lualinn la ita pas'** "lat will ininrv to ii n w;<l«
p ipialaritf and Jiltcutivr prrnaal, aaU a dcvrra i-T
Oufjlnni mil m'ler ■ilain'-il l)i«>ii|tli Ih« iLflurnec
r>f a aiTjflf Wiifk Tli^niithiir hna rnurli tnEmurrd
lb* pnnlieat alility <•( hi a bmik by puiiinit litleif
OTcr IbcphyaicaJ. biilam -al,afiiJr'iiii'nrrrial iiiMUny
nf mnli^iaM, and direoiiitg utiFntii-D fhirlly lo Ih*!*
phyni'iliyieal arlinn.and thrlt applk'alinn fv> Ihe
a<ii*l><>r.in')a ni rurauf dtaaaar. He I(B^Ip« Mvpnlho-
aik aad tbsiJir wbieb are iiiBllBrinf lt> nuajrnmlirBl
wrll*r«, aad av liable !» iraii ilirai »iritt , *iij < «-
laca kinii«ir to aneh facta a* ka*p Ix* n irxd id Uie

MkBlkifl at aspartMiM'—CAiiaca JbrficoJ J»mrmai,

SIMPSON (J. Y.I, M. D.,
Piof^Kiror Midwifery, Ao.ia tka L'alv«l»>r ^f Btfikbarfh, As.

CLINICAL LKCTUHES ON' THE DISEASES OP WOMEN. Wiih nn.

nMiMiB itliMlraihMf. In ou« baiHlwiiMi ueiavo wlunM, t>r uvnr lOO pagea, cxin dolfa, (3 CO.
(Tfew RtoMf.)

ThJB Talinblc woib hiiviiiit pa»M-d ihrAiif h ihc colimni of '- Tub MiDicAtlf iwi ard LinfrAKT"
liir 1800, 1^' 1, and \1VVL, In ni'W ri/tnpVird. and may tw tiMl trpftmia la mie IwimIpmiw vtAutao,

Theac L-r.'liitrs wnre delivend tv l''ftr>*i>r Si<np»«n nl Ibe Itnyal luirniery (rf'E<'mbon[li. and
Wcrvpubii-hod in ttii< "L^mdiNi Mrdical Turin aiedOiittlle" Juring th« rifarn fSW, ll!i40,aiKl l-S"!.
Thediallnfiii*b(^ re|MiUi)'Mi o'ibe i>iiibi>'. and iai> vhIuhMc piai-iiral maiiar c«ni*inrd ia ih««•
lures liavB •twmcd lo eaoilc Ihwn I" a "uiv |N<(inaiMinl l"rui than iba pVnBWOenl pa^u ofm perl-
udiral. Einhr«rini[ a widr ranfv iif >ll^)r(.■l■, aiKt viach ome «Ubor»i«l)r Imied aad miDplvie la
>(«ll, the vi4uine can Bardiy fall Xo pruvr ■ valuable adrfiiioa iw tlw library of Um jxaoiisii g phr-

The prmolpel li>iiir« ritibrnivd in liip Li^i'lnr^i ar* Vr^icii- vaginal Fi'lula CainH-roflho ri-rrii",
Trvaimenl i>f Care imtra tiv Caii"iH'», lly'TiPntirihipa, An»#Tt>rrbirn, ( '■••nri:*, i 'onlrni*imii». &i- ,
of tbD Viwtna, Vutvili*. ('iita<rK of Uaalh aTlcr Hmjical UFrraluin*. MurKicnl Frvi-r, I*hM.Tgiiia*M
]>lrfm«, C>»!n'i.alirija, P«i|vie tVHiilili-, IVvip Ilieiiiiili-'iiii. t^punum Pn-itnaocv. Utariaii l/rupiy.
Ui-uioioniy, C'raiimrknin, Di>c>mm uI t\te Fatlupiaa Tul«^ Puiripcral Afiuiiu. Kub-luvululiun aoJ
■i-Invn'ijiioii III lb*" liitui", &p. Arc
a arrirB of ti!Mio^raph* oil ili-rHr impnilani iDpk-^— maoy of wblHi Ttvtvm iHlk aTirniinfl

lordlaBT)- ii'xI-lvKiko — i-lii'-idaifd With Ihe WMeneire f xpartmod and readiin«aof fw*wiir«t! fat

wbii.-li fruH^aor SilnfWMi !• «u diMiiiKui^hcd, ibers ai-e ^m proifitK-iera wli'> will nut flad ia lU
p^iis imtl«r of Ibc iHinoat Itnpof lani.'a in Ibd irvaiin.-ot of i>tj»L-ure aiul dilllvtilt n«M.

BI.ANGHARU * hBA>8 UEUICAL

SAnaENT (F. W.I, M. o.
ON BANDAGINa ANlJ UTUKK Oi*KKATlOvNd OF MINOR SURGl

NVw ciliiiitn, wilh an eitdilinital cb«|>(i-r on Military Margery. One liiui(l<ORia royal 12in«>
(H iKurly 40l},|Hi«c», wilh 184 wood culs. LMlh«r, f 1 SO. (/VW R*a4if f
The value arihi* work m k bandy uiU rcnveni«ni raaniiat lor turreona ei^iCR^il la ftcrirv ^1117)11
ItM lield and.tMu>t>iial. baa inducvd ib« putili-han lu rvnder u nior« ouiufilaiv uir ibu*e f urpow bf
llie ■ddillou of ■ ctinplsr on Kun'»lio( wwind* and oih«r ma'icrf pvcaliir lo iniliur>- f<»|prf. la
ItapreHtii foim, iber^-tow. wilh no increatc in pnoe, ii will be fuand averr cbeap mimI »uon«Msi
vrnw-VKKWa (of cumMiliatian and t«tor<i«M in ibe daily esigcavtea uf oulilaij ■■ yrnQ u ui«i)
pracike.

We have rmd [la«Tf«rl«'> Mianr Ulnrrvrr wtth | Th« inatfuoUn flv«M apen tbv aitJrM of Jk>*
p)«aa«r«BEd pii>St,i>tit ioBniDj teipecia thF volapie 'of<<>(, ii alone orjtRat nine, anri wail* iIm a '
now Itrltxr u* iiiimriiautiililr ItiutrfDil* it. W<> in»lFB(ljr prii^iae* M IMlrsrl th« alBdeoM nf 1
eouitfci thai i" better bnnk cuulil ^e plKMil to tb« cine, hdo ik* yoantar phyticiao*. w« will wt
ban a* of in lioapiui] dicif^c, «i Ihv f»a*g ivrgruD, ciprrivnrcd finjaiciae* wiU ubialn nauT
whi>«a nlu>-.4iiiiD la l(il* n*peet Ima »»! Iirrii ^n- ; lanlr ratuabia ■u(ittiu(«i« hj iia ptiual.
f<>i!t»l Wf iniktt fotiTliiJJj runiTiivDi tliii Ti^liifna ' fivt ■(trniiktiag i>i fiarUfulallTe fnrUiT, wn
aador wliicbltif mfdica) ttu4ri)( ihwuld iu(-ilt'tn*i> coaclvdenar btlrf iiotlri! by Myiac, Uil il arl
Ij •iDitv. til pcffm him IT If III ihear Kiinur lurtiral 1 fiiunit iiucnrtaanriil •ilitfitnlDry ui«bihi[>ttil tr-i r-i''''*'iF4i
■Blfh injglird, aail «s wHirh ■ grajt |>orii.ia 111' hK (lujrlilf uitifilrit Lii the w ' ' ' (Ml

rfl|i(itAl»in Mfta rulure mrffiin niQtl rvJilmliir real I aiiil al tlifr tditfr lliiir r. 1
AbiI I'l ihr lurifrtiD 111 pmolior it Hiuml [ititrp ili^ir <*'>nnfnl*iit i^ffrrarf C'^
a valaaMc vulum«, ■• Inaliueiivr i>n rnany |>»iiili I Bi^tUa Jltrf. mU Burg j»»'mit4, Jtiiir,
wtich rip mar baa* loti«tm.— JBi'im* A»urtt<i* ,
^•«raaJ,klar,lMl. |

SMITH (W. TYLER), M. O.,
nyildUD AcEouebear lo 81. Marr'* Hoapltal, ftc.

ON PAHTrEITION, AND TUB l'RLVCIPLE3 AND PRACTICS

UBSTETKIC3. In ow royal i'hw. volume, eilrtt cloih. ot >tOO p*|ca. •! U.

■r THSSAMI ACTHOR.

A PRACTICAL TRRATTST: ON THE PATHOLOGY AND TKKATftfRNT

OV LEircOKKHQ'^A Wjih duiBerom tUininiicu. !■ one T«cy kaadaonu ocuvo Totam,
«llra elulli, 01' aUHil 4!A paffim. tl SO.

TANNER IT. H.), M. D.,

Pbrairiaa to Ibc BoainCal Cur WoracB,Jt«.

A MANUAL OP CLINICAL i^IKDIClNB AND PHYSICAL DIAQNOSi

To which 1* added Tb« Code of Eihic* ol thu Amerlcsn .Mi^lical AsfncuUiM.
Amcriiwii Ediiioa- la oao imlToluaie, mall l^o.,Miir«oioih, tf7| eeata.

TAYLOR (ALFRED 8.). M. D., F. R. 8.,

LootnrrroD Medical JaitipxiJrnrreacdClieniittrr la Oar'a Unapital.

MKDICAL JUKISPKUDENCE. Fifth Atncrican, from lli« Kvcoth imi

aiii! riiliirfietl Loiitlua r>di1k<n Wilh Nuf^a nod Rflcrrni'e* in Amvriiian Uvna^onn. Iit

MakTsHokac.M. U. Inonelargvtnro. volume, teBthL-r,oro%-cr7tK)pa^». {Ifom Rr^Jf_\ \}\
Thia flandord watL ha^tng had lb« advuiiaffe of iwu rrviiiuMr at iIm- lumd* v( iho auihw m«w
Van appcaiMide orihe laM Amerioan udlUon, Will be I.tiind lhi'ruii(;hly rrvi-n( and liroivibi dp t%
plvtel)' [u \\te |>re>«m »ia<e of ibv FCirncv. A^ a wcrk at am horny, a muM tbeivlora baiauw
puNtlcn, ^4>lll ar a Icsl-book fur the Mudent, and a edoiprndiOM trvatiM lo which tlie pruUiuu
an *l all liiiie* rclvr in uaic* orouubi ur dillivuliy,

Nu WL'ik up im Ilia lutiteoc ean be put inlu ibc 1 Aaeiicaa aad Brliub Icml n»fdlets«. It akflal4|
haa<l> ct (luilriiU eitlvM of law at IDflttlClne Wttieb \ m ll>* in>*»rMi<'a ■'( tVrty pbjaiclaa, aa IhpaaihJ
will i-nguirf' ihrm imire dIumI* or pn>fiiBbl)- ; aiul , » ■«>» i.r fr*«i and laerr aai^ In^iUan l» '.
aoDc I'liuld tic I'Hrteil to Ibe bucy pracUb-Miei ol puMir m wril k* in ihcpmfataHia.— At. I.«*m,

aiilinr rsllinit, (ur iba purpuac of eaaiial or baaijr
rdferenee, that w»ald be sore likely toaSord tbe ai4
dodrrcl. Weltii<r«rar*ra«imraeDdlia« tbaltnlBDil
aaint maaual {at clailT aae.— JoMricda Jtmrmt»l tj
HiJirnl Siunrtt.

1 1 i> Li-I exe<ut Cit pralae tn aay itiai tJiaTolnMt
befurr u« In the veiy best imitiai estanl on Medical
Jariiiitudciiec. lu at) tEi|t III i a, are do Hot Wiah to
b* uudriiiiiiul aa ilsifBPtisii from tba mcill* uf Ebr

aiul Aarf . JomrK^I.

Ttti wort of Dr. Tafloi'a ia ge»erall|-
ledgrd to b« nne of llie abl«il extaal <« '
(■r iikCdifal iBiiapiutlrarc |i n MilsiaJ
ni'iil aKrai'lir* do iHt Itil we bavo am
plyiKgan Dioch IkhIi Ii. Inlereai Bbd M
w* o.i aoi hraiiai* ii> allirw thai aftor har<w'
eiiniBcarnI Ua i>riiiMl, liwooald bafMvralM
la ibe laal
■■d aaoi
iael
, ninniMapiral,

II I* at noce eiimpirliaiidve and rmliiTiiily prae- ' mNja'-ii nrvft Ivti.re paUllhcd,— U«rlul««i
Ileal, nad by ■nircraal eonaeot (lunaaalihe ncadoJ ' JaamtianiJ Hntt».

an THK Sana ACTHoa.

ON POISONS, IN RELATION TO MEDICAL JtTRISPRUDENCK Al

MtUlCINE. SM^ond Anierit-«ii. Irom a ^mxiimI add revbed Lotiihw editiiM. ta oae larM

o<^iav<> v^^Iiime, ol 73a page*, kaifa«r. S3 30.

Mr. TayliirV piwiiioii b» tb« kadui^ awdical junat of Eofland, haaoooferrcd <m him cxL,
■wry Mlvaitia^v* in noquirinR csporioncv on iDvmt aabjeda, aeany all uaca of nuwent
r«rvrrrd i>i him fi.r fauininaooii, iti ai> i-iptrl whi»w icsiiBiody 1* yraoMlty ac«Rj4»d aa _
Thf miilif of bi> labur*, lb«n-l(ir«, kh gBtherrd lORClhcr m lhi> voluuie, OMvfufly TinlihiJ
*iiriH| mid pr«F«nit?(l iti ibv K\««t a(\A w\vUia\^V M\tji; (or whick he U noiwl, may bu 1
H aa nckii<JWlcilg«d auiVitiVf ,anA a»« (uiA* Vi >>« VASuw*^ -vVVh "—]>■'-" — rn^hwrr

AND SCIENTIFIC PUBLI0ATI0M6.

TODO (ROBERT BCNTLEVt, M. 0., F. R. S.,

Pii^nwt t-f Pnjiiiilnf)- in KIng'a Collide, Lusdno, bbiI
WILLIAM BOWMAN, F. R. 8.,

Ekmaiiatralix or Anklunf kn King'* Coltcgr, huoArti.

THE PHYSIOLOGICAl. ANATOMY AUH ['HYSlOLOOr OF MAN. Wi

MbiMtt thrtv tiiinilrril large ami beauiiliil illnsiratjoat on wood. Cooipteie m oae t»tga oou

Toltunc, o( bTio pogeit, l«utlwr. Priro S4 30.

ET" 0<*ollpiiirn who havp rFC^ivnl [lurlioiu of lliii Wdrh, ai puUlahnd In ihe <* Hkdic*[. Nswt
AMP LiKHAKY^ van Duw i»inpl#la tiMir copi**, if iuiiripiliatci aiipliniion Im idimIm. Ii will be Alr<
aiaiivij Kn rollixv*, rr<<« by mail, la pnpwr cov«ra, with ciuih back*.

Pakt» 1. II , Ul. (pp. 125 lo »S). S3 M.

Past IV. (up, U3 1« end, witb Title, PrefacA, Conienr*, Aro.>, CS 00.

Or, Past IV , ticcnvn II. (pp. 73ft lo cmJ, wMh TiiIr. tVlarr:, Cmilrata, *«.), tl SO.

Jk n>irnitlcriit uunirlbniina la Brii!*'i mcdii^itiv.i •" wfII «ir«piM(ii(ti« wiBtaofihe vHietildv^i'iiI
ntd Ihe Anirnnii i^titittian whii iIikH r>>l l'> pntt" III riitri{>kli<-n *iat hoim (hui l«n^ ilrlsi nt, ili.ii ika
II, WiL feB*f rxlcu to reudciDc of the nujtl laiirai- '
tin bonka uf (»> niDvlMJiLh eoaMiy'— /f. 0. Jtbrf
•«4 SarK. JWrnai.

lliiinr>[Friini~T(rthiiaC>rpnnl«r'iPriac:ptca,aad
IBOTe RDilerB Uian itie >eceisiblcediil'i<B'i( MtillcCi
EIehifbIi; iU Omili air biirr. uul ■uiTieiciCi U*
4f*flrlpi KiBf virid; 111 i)la*tniIi<FDa«JCaci anilcopi-
ov» ^ and (la lRii>ua)|e laraa and jwriplououi, —
ClntfltiiMt Mid. JvarMot.

Wa kaow of ac woikou Uic lahjcel o( fhyiiiAogj

■ atli''i*nii«lit trcutoaeeuraer brpcTK^ual euacrra-
ttuti,— 5j. Louii UtJ . mrnd Snif. /oafiMil.

Out noun*, iBoci||h It «naveya bat a vtttf fmU
aiMt iiBjie(rM-t Lika <■( At ioachi iiiile aiiil iiE^ifiriiiuBc
(if (he vrntk n'W voilar ennanimti'^, almuir tr..iD-
acvadaour Iimila ( moil, wllli Ibr Inilulgi urn •!<' i.ar
reaiMri, «Biil liiry will priuac Ike biiuk
for thriDMloi, ■• wr frrl wr csn wilt, •-■■ii&ilciioc

rMotnuieoi) il, wg knve ii in i*«ir iiiui>l*. — 7At
WtrtAmfOna Va4. aiait Sarc VearaaJ.

TODO (R. B.) M. O., F. R. S., ito.

CLimcAL lbctdej:s on ckrtain diskases of the urinajiy

OKUANS AN1> UN UKUI-HIE^ In Mit^oolovo v.>luiue,2!M pitgee. iSI dO.
BT Till SAMX atmios. (.Vw Ktady.)

CLINICAL LEOTTIRES ON CERTAIN ACUTE DISEASES. In one ne»t

oeiava volofnc, of 330 pageii nin clotii. SI 75.

TOVNBEE <JOSEPH), F. R. 3.,

Aoral 9urg(«a lu, aful L#«iaier on Ruifvr)r ai, S( Narr'* ll'>apluL

A PRACTICAL TUEATISE ON DISEASES OF THE EAR; llieir Di _

Dunift, Pal hoi »fy, anil Trraini«nl. IlIiioKaicfl wilh on<- linn-trcd eii|niving« on wood, la oii
very bandAonic oclavo voltuo^, exlm clotli, t-1 00. {Jujt htuMA

Ttir Ofiik. aa Waa atatn) al iN* 'luta*! •<(

lice, i* a Ihiilcl i>( ila KiniJ, und rveir Vif- anU pa'a-
rraph PI It aiv Wkilliy ••' Ih* riimt ihiiniiiKli aiuilj:.
Ci'DaiiJcrrd ail in nil — at bq •iiijciiml wu(k, wril
Wrtlten, pnitio^plxpally ria iiiiraipil, iiad hai>pi1)> t1-
iaaitmiMt wiih mtra and itiawtrfi— il la lii far th«
tblctt nii>n')f<iapn thai lia> rvrt ajitirnrtj »B Ills
■BBl»ni]r anri i]ia'iia«a M th^rsri add nnc oflWaioat
vaiamtlB ci>nllibiiliu(ii lothcaitandiciancaof mi-
apry la tne niBrifcnili otaiatyf^N. Juut. Kt^it*-
CiirMrx R'M'W.Hcirl. IKHI.

in^ni. mi'} af\th a aariri^ anil iinNiaavnl jn'^Rn'T]!,
Wlirfi w* nftrm Ikai a» ■ trr«tl*t .>n \nraJ Hiir«rr)-,
)■ ta wilimal a iml In iiur lir|taafp m any "'nir —
CAartMloa Mtd. Ja»m m»d Kirirw, Hopl. KOO.

Tlia wtifk of M>. Ti'ifubai ia uuil'iulitadly, iipiin
Ihe wtiiilP lh« rauat valualila pdnlneiioeof Inn hint)
in •Inf laDRan^*' Tim «iiLh»i' haa Inn; ii-in ku>>«'a
by ttii niiinfriiu* ni<^Di>(raji(ia npon 4ul>|r<ria r.in-
ne«lnl wilh dii«uMor iltaear.awl lanuwiifar.lFtf
■a IIhi l4igliaai aiilliurilr nn mnat paul* in Ul* ■<«•
Mttiiical III icicnec. Mr. ToynlKe'a wotk. aa we

To (pi*uiii rnrai] aui'ti a work, rvan aflrr th« ninic oavr iilicaii)- aaiil. la unduulileuly IW lui'ai trli'tiln
ftlBt ve bovi Rli'i^n vf Ita or>||Uul eiealtcare and ' ruutc Tor tnc clntfy t>l ibe diat^tp* d iiie cur >i> ai,y
Valnr, WoQkd Im a wink of aujMrenifaiiiua. Wi- are , LnguagP.aad akuald lie in Ihf libiaijr (if rvctj pkj<
•ji^iBg wilhlB UmIiibiU 01 ntuilcai acMi>wlnl(- ■ici*«.— C'AUa<* i(<il. JtHntoJ, Jal),lMu.

WILLIAMS (C. J. B.I, M.O., F.R.9.,

Profeavur of Clinical Mntlcine in ITalTctaitf Collcf*, LunilciD,Aa,

PRINCIPLES OP MEUICLNE. An KleueDtai; Viow of tbe Caiues, Naturer

Tfeaimeal, Dwcaoeui, and )'rO|^iMb of Uiaease; wilb brief remarkaaa HjfWnwa, >ir ikf (irr-
•amitlAoorhMllh. A n*wAiiMncu,l>DiBili»iliird uiilMvia«dL<Hi4oii«dnMin. in one octavo
VDlnme, Inttwr, oi abuui .'SOO paces, t'i 90, {JmH /wiwf.)

•ipraaaed. ft la a Jndgamt of ali»o« vaqnaJitad

praM«. — L*»dti* Lameml.

Wa tnd that lli« ilnpty-iniriaaliof matif «nd
atyleoTihlBliaok baTcauiai faadaaiMliia, ibat we

bava aa«uwaeiiivtl]r bun| npoa ita MgM, noi kiv
liiii|, fadcAd, f(ii uitt uwn pmSt, bat l(>nf r [ban ra-

Tlew«rt eas'b« permitted U> iikdulite. W«kave ttaa

fan*

ludfi

fanliaracainla'loiliBauiifMicaiiiJ pruititiimf. (int
at of tha work ha* aJroadr Oeen BaOcicnlly

A teit-b'M.k 111 which do othar la oar lBBgua||a ia
eocnpaiBMe. — Chaitttlan Af(rfH«J /•miaaJ.

Nn w^fk Iiaa avaa a<ihl«*r4 or oMtntainad a innro
Ueaerrtid lepulallott.— Fa. ifad. ««4 Sarir. /aoraMl.

WHAT TO OBSERVE
AT THE BEDSIDE AND AFTER DEATH, IN MEDICAL OASES.

PubliatieijiiniW tb^aHiburliy of iheLdnitoaSocietyibr Mi><l»r«l Obaervaiioa. A n«w Aowrfcan,
Imm ibv acixnd and twviscd Loadah«diiioa. laono ««>« liaiidaoaw*oluB«,rovaI13uu>.,eiArm
sloth. II 00.

Totb«obaerTerwkOpr«ftfiaec*raeyloblaadttral Oaeof IbaGnrat aldi lot T^'at pra«tll1'«MWa
awl pfvaiaiqp tnOBTa4l— laa. llm lllil* Wxib ia.-«- kavBavaraoca.— f'laanfWaT /vanMl ■/ Jfidioaa*.

ED at

LEA'S MEUICAL

Kew oad much eoluged odidon— (JtutlaBued.)
WATSON (THOMAS), M. D., <f.O.,
Iiatr ftyiipliin tn the MiiMI«irrx Untpiul, &e.

LECTUBR3 OX THE PRTXCU^LES AND PRACTICE OP PHT8I1

Urhvorvd ■* Kitiff'* C»ltps«, LuaitMi, A ofw Atrn'riran, (Vvoi lb« U*t rwt>eJ Mil en
Enitlnh e»liiiom. wiih Ailitliion*, by D. FKASfnCatinti, M lt..iottiof nf " A Pni>-iir«l Ti

.0 woud h
iwt papa M

■Ml ihr lVi*ra>«* iifCliiUintn," &«. Ur'ilh mip huiMlri'i) stii) fijc lily. Ave
Vie v^ry l"KW Bnil hNndxitiw vohiine, jtnppriBl ae.iasn.ot uvcr I'JU'
*iiik11 typp; llut wliule sltoiigly buund m ti.'allier, wilb niked b*nJ>. 1\ ..- y

TbiU the lii^h raputBlioii of lhl» work mighl be fully matnlainrdt Ibe Mallior I -■* ii

Iliorfiich rrvifinn; o-ery pcniou liait bctn i>iaiiiiii«<l wtlb lh« aid of tke «••■ r. • ■rtre

ju palholu^', and itia re»ultc of imxlofii invrtiwatiooa In both UkMntMvl sud pnwtiiutl auhj
bAV« bwn MinfuUy wentbi-d and einupdiL-U ibruuiiltitui Jin pajm. Th« walehni armjlMi
eOMof hio likewise inlroduixd wbaievct p(i>M:wM!i< imnsduil* imparl dbo« u> IImi Amvrmui
in rclMioEi lo cli>cii*«s indOeni ii> vut clmioii; wbu'b an! lilUv tuo«*u ui Ennland. aa ~~
puiniB 111 whii-ti i-i|vri«^i>T hm ha^ Ipd lo iliiT'.'rrni ino<lviiof pravtiM ; and Imi h>* al*o
to lhl^ oe'ii** "■ iUuiiiu'.iKii*, bcliavinif thai m tbit mBiiiiirf wliMiblv aK>j«iaM<,ie may bv rtMc
lb* aludriii 111 clu'-JiUigiig iIh! L«xt. Tba work will, itierer»ra, b« fouiid iharoughiy on «
iLr mOii ■duntiopd atvlo ul tuedical acicjicv vti bulb «i(iif« of ihn AttaaiM.

Tha MhhliiinK wbltb the Work tin* rrvclvc^d arv ohown bj (be (act Ibal nalwilb>taii(Iiii([
larxvnirni in Ibr nice of Ihe pn^. more Ibnii tWn timiilrpil ailililiuiiBl puKcs haro b«<ca oci
(>i iviv>mtT'»ilnie thr^ two larce v<i{iimin> ol ihi? I. > ' ! . it (wbicb wll* ai ten diitlan),

liir CKinpiir' iJ a Fin^ vfrlumciaiKl In nt pr> > Miaiaa the Mailer ot at iea<i

oiHinar)- f>viavu». Kdirvina il lu be « wirk wli .r on llM IsUfl of every pbt-Mnaa,

b^ IK Ibc bum}* iiTevery aluiJriil, (lie piiliii*ber» hav« |imi .i at aprice withia ihe re«cti of all. nakutr
ii ime of thf ctlMH)>e*i book* as yei prvaeoierf 10 ibe Anerienn proibixiun. whil« at ike mom ttoa
ib« beauty ol it^ mechanical esuwiiM twden it m» e)(cee<tin()y nilraoiive rulunie.

The fiiM III rilillnn nnw afiprari, tn ealdBll)r re- l TlHilxctii rot's kkill, lii> wislrroi, liU Imraiagii
VIK<I. ai to *<lij r<«ai()Fri)t>ty )•• lli« Tilnr v^t [xinAi ! pquHllcit by Ut Eai« trf hii k'-"' ''''• ' '-UMi-xt

■liraily ■i-liii-in'1nJ(cil, vrhciirTnt llie KitRliali
Itiiiiceti (tail, ui lir hpy'-mil III vnmjiHiiiNn tl>« ivir

RfttrniiilK «'4>tk nil (IIH Piiiiriy\*m iiM Pruciii'' i-T
liystc III the wlinle iBitge at niMtivKl llieraluie.
Evriy l»'?u*r? t'n[it«in» (ir.mf rif itii>i>»ti«nic niiiii'ly
of Ilic liullti^r ['< tlrc|<r>cc Wiih <liEailv.ii>i-kiiK Km-nr-
IMffr (i( Ills 'lay, aiiil in txiiig llir iptulti (if ili(
tah<.'i>. mil "■ly "( pliynKlniin, liiil •■[ ciixiiiitl* anil
bui"l'9iii'. lirf'itp In* r*a<1a(*, vrhtrvv»i lliay raa
l>« lutnt^ 1" inKul •miKlil. Unr ti-HC-rly tn<>w(
«rll*1llft I" nilliil'v niiwl Iht purr, (inii'lp. fmcltila
Eiiali«li — 'Ii- i«»t BiiH'unl "( a*»-fiil pracliirai in-
fi- ■ ■■ <i-ti»«* lot" ttio (^«Tiiir«i- iinh* iiian-

h '<f, DnBiiiiniinc fllianu-trt "l llir L<.-c>

III!' I < :_ 'hit'iif>ili\tw>lk. — LtH4.3ltd Timii.
Tmu llir«A ailmiraMi: Vnluinei «ime budXa the
pl"fe«>ln« ID i]iFir fiiutlh filiiinii.ali-iiiitiliJift in tii^ve
dill Ins UiaJixil allcibutc* ut niinlrialiiin, luilymrlil.
f mil la citllirnlion, elporiipM, ami rh-ijuifiwM.-, will
Wliieh llicy wrrr fti'in llir fiiit invrttrJ, liiil yrt
rip:li«r ^^''s Erfurt in 111* iiraiilu "< ni"ff jmilirnMl
tiL>eiTSiii.4i, nnil in Ibt ablt? ajipim>rli<<ri i<( Ilie
Utfit advanrci, iii tiiilHi'liicv aui) iii»ilK'lbc by hub
Of III* Wiiai pr'^uuail ia«lii:al (IiicKf o uf tlia duy.—
Lawfaa Laaiai.

■|ur»rn, nod Ida l^i lili

■>f incMifaiilbe'*.— IV ^ i

W«|an«'t aannlM, l>«nN»i ■aajuX'Mt
wnik an Fractkc^lbe enpiKMu vditiii.iea bui
wHifh |th«(<>artli*4ttl<ia| bare (lv«a ii alt i»t.
Tclry and fnuch n^ Uir latriaM uf a aaw but.—

L«ctarerk.^ractltlo»«n,an4Uuiimau(|

iriil n|iulif hatl iba iaa|i|i*arBn«« v€ H

W Wuiiuii iaiacr»mor>rrir'-4l<>arlb

Wa mctrly \ia juvlW Ui iim nwa IVrlinf ■

arc *are. of the wliul« pii'lrakuia. il w>

fur b>*iB|[, tn lb* liiw'it- ■•'■■ • — >■ ■ '

praeiLcc, miiatc loaure i'

by lb* VKlin Hat 111*1 <■! i! -

Uiittt cdiiji'h. wtii'b h- ■■

liial tliiFr yrdi* Fui I'

uvu»il lit Itrlu'ca U '

iUii<uf[ii ili> wa-iir wmi

li*>ii> Willi: II |>'^>rc thai i

■<>Utbl lt> tiiiiiK op hU I

mm I rvceiii iii.<ai(iaiuu«>* lu •i;i»i<re,— in

WALSHE (W. H.), M.O.,
Fmfeaaor nf tbe PriaHpIr* i>n kt.

A PRArnCAL TREATISE OM DUEAPES of the LUiNtlS; inclodi^y"

tint Ptmcijilo of Pbyjiicjil niaf{ikn«ta. A m-W Anirricon, frum IIm Ibird revimMl wid marb «>■
• lat^-d Lixidon cdiiiiia. In rinc rol. nrlavu, i>r-l>Sfl fm^'n t!Z 2>V ,

Tlie pti^-L'iii ediliou hni' bcL'Ti carclully rcvtp«d nnd [uuchenlarired, anJ tuay be uul iii iImb maia
lu ba nwtiltcn. UcH-'riptioa* at mvvrtl diaeoM*, pravMiuty omitivd, hiv nuw tMntdoMif lie
cauwM uid mmteufpriMluatioa uf Ibe tnoK iiii|Kiriaui allevinjas, auiar a> tbey po»*«M di ram prac-
tical *ifCBilie>no», are ^wmoDlIy Imrnirrd >nio; an\ vStti ba* twen ^>Mle tv bimu liK iliiniiipliui A
Mial»nii«ul rtmmi'ler* lo Iba Invel uf Iho wniii* •>!' tin- propiinu phfi'ieiaa ; and ibe dW(
pmyaatii III' i-ai^h ciHnpLaiot aic more cuiiiplciely ra>n»i<hiri;iL TUa Mrtuuai* >mi TsKaI
iIk Appriidti ((.tiioceniicig (be mtlueucc vf ciiaiala on piiJiiuiuary diaordarn), Iwyp, orpou*
largely exieudod— .^atW'* JV^Ma.

Bt TMt «aMB ALTHOK.

A PRACTICAL TBRATISE ON TUE WSMASKa OF THE HKART

GREAT VE:*;^Em, itiduOiik« llw I'rtnoiptei of rii}Tiiutl l)ia^afi» Tbird A(ncriraii.fi.iai
Ihiiil irviicd and much eiila fed Looituo edllh«. Ik une han Jaome oclavn ruttiBui ol ttit
HXUkoIotU. W23. {JaMiitttJy.J

Frtrm tit AittlkvrU Prtfoet.

Tliepraitwit edllioB haa bmm Mrt- fully reiiosl; niiirb new nuUlar faaalMnad<U4, aMlbeevilw
wort: in a iDouur* rriiMMfrllvd. Niiiiieroii* Incli iuhI diKcuikiiiitt, mgraor kn- . ■ i<r nwewl,

Will lie touai In Ibe dr>ciiplioa ul'ilii.- priiit'igik'- ul pliysiuil diu^iiuais; bu> tbi- i .i«m

becB DMda lu IIm praclical purlii>Q» u( rlir buMk. bCVrrat allc:!: I luitKi uf wlm i ^n

bail been ;iven in ibe prcviutin edirixtif, arn now ircalcxl of ui Jr'ail. V-t <

iieart, Ihe l(c<iiipncj ot wViiffVi ifc»lti\us^maikd by ilie miacy ibey iii(|ji,t.

•idrred; mure c>l»ciiB\\Y an awewi^fc** toccm «■»*« w> w*4*i \Wrt -wyaBQuaL luunrr cjc^jm

ounawiueully lUoir Iroaimenl mote !.«■;«««(* .V-s an w»Ai«* -A Vwiw 4>(»iMttve .^

ND SCIENTIFIC PDBLICATIOMS.

A 8TSTE

TfMd Anwrirsn.

<U)d muob enlatgad adltioo'— (Jnat laiuad.)
WILSON (ERASMUS), F. A. 3.
UMA.V ANATOMY, General and fipecial. A new and ra-
(hvU>i nniJi!nInft(vflC<iK*i'h Cd'iioo. Ldiinlb)' W. H-Oobkkcht, .M. U..
ttoSt»H'r trf Atiaiomy m itie Peiiii«ytviini« MrOn'iil Culln^u*, A;*, lllo»l ruled "ilh ilir*«t huiittrva
■ad niiieiy-*vvFii«ii$r>viiiKit(>n woml. In un« Urge %ni «xqui*il«l)' prij|i«d wilava vgtums, of

The ptiblUlic^r* iiii*l Ibat Ihi? wrti earned rtipiillllon ao laM^ MJojvd bv Ibik WurU will ht more

m<mt fttfuWy txma\tn<^ by ihc ecjitnr, i»n<l irrnVftiirln nl" UiiJi h«te heen UireiUi-i) (o minidnridi
flverribinff which incre*'^ tMpkOien'Cain i1)i^« !■«■> nUKre^iit^d u dt!r',riJ>le to rrodvr ilei^implrie
ttfzl-fiuuk lor Itiure fceklfiK U> <iBiO> <*^ "* ra«W in aiNiuaiiiianM with Humtn Anaiomy. The
uiMiiit olvUtlMu wbtv&il Us ltua/«c«iT«^Ky be t»tima'ed (root ibe fuel ihot ihu pweiil
edltiMi nmiRiai' uver vtie-nMinl oivA^ktllw tXBdiliv l«it. rcii{btinR « •niNllvr iyp« and nn rii'Bneii
pafi: Tequi»il« I0 beep liie nt^epwimtii ootiwitieiil »iie. /r>ii editor bar esirrei^rd ih>' iii>i»»i

iWiibcr o( illu>irn-
tii ilw Um, ihus

nil Ihr nlnr-
:iiiDil><^u'lir

w (•(•■niiiF liis
ie*nrc ibej pnf-

impii riant wikquq
ly uii(oliU>—

OiUiUin 10 uliiuiii erilire akarti$_
lion*, t>f wbirh iM(« art) A^m^oor
brinirinK di'iincly hefomdireJWijrtho*

ll aM]t tw rnriiininrciilnt'ln V>e (liri^'nl
dliliafalibt^ tif III Heciiraeir aiid rlmr
acripliiiD lh>D l>y it* l)rpii|niplilbi>l c(i

WMMl-caia at« utquLaiw— f rti. oitrf

and baa

nd 1% ■

I llnltM Dwllty

nui nditiiM I
ller«>t ur \at

'lU

An (Iqniil wtiiloti «f nne of ill" morfi uc^"' ^""tX/ji

a«i.-uraliMyt(cina ur ■iiiiMDic4il ipIc.
b«en tMutI rr»n it>p pr««s The lllv
rcallv bm 1(1 Kill. In 111 ilyle Ihc wiirlnasxIi'tnEl)' I
emieiieun'l Icieiliitilile. nn mie c-af^^tAraLjr jAp
mf (hi* vulnme willioul lictnf ilnirk wllh llr^tcill I
BY THV lAMI *,nuun.

ON DISEASES OF TIJE 8K1N.

LotidoD editioa. In one haiid-inieociiivovul

r>n woad,«XiiBclu[li. (JVoii> Krdi/v.) SJSd.

Tbif fla»MC'Bl O'ork, whicb fcr tweniv yean

In iha Es^ii>fa tanffuanw <j«i ita impnrtaui i»ib)«ci

vtfim avilinr. aitd i* iiuw pr^«iitei| a* efnlnxiy

nfrlmii
ripllun
tudraLi,'
rtKVt^t uDlb'
|eil-l)>Kih^if Ilia

reit»*r I
■111. — H'li

tli'n Vit aU

r dtarly

Mb«

Botruiuirot
t Itlitfceal ounniMMlEUim.—

riotiev oil all inNllvrs ciinnL>i-:(>il w)ih ih-e>>-e>iil 1

tieteriiiiii

Fiftb «t)lurged

cVFUpierl the DOiJ>ir>r^f ibc Ivad'iig aiiibariiy
»IU"i pwiTjireilalJioriml* nrvi*ivn at Ihe hiiiNM
^ (r>iiiu •jrstm'^t**! if^Mi;^tiiin> and esj.L*-

•Im>wb iIw indu*lry ofihn aiithijf, Bni< tii> iletefiiuii>ii;ilii imil n >niill ii»tiV» the {i("ili<jii wJiK<a it
hail B4^iiirad a> tbnroushly on n level wiili ilie nianC advaiiocd cuVtfiiiaa orniMlical Miivnn*.
A few iiol4ce» of the W»l ediliofl ure uppended. "X

Tliewritiu|[»uf WIlaomBpoadlwaHiorilieikiii, Bb^ul fonrli^n feariU"! Mr Rcniiaui \^ ilon l>*il

■re l>f r>ir llir> mi ml aclnanSr anil pcic ileal ll>*t dtrjiii nivrii «i>iiir >«||ti to (br aliKl}* i-[ Dik.i»?i

haVR ever I'reji |>rpieot«d lo ibr taeJieal w->iul nn i.r ihf t^kla, aii>3 l>e then exfietuJ Titi iniruimr nf

thtiiabjeel. TI>ep(ea*BtMillii|i liisfr** iiiipfuvp- ilrirui[iii|[ i\ii fit urv Ufa ft iha HiieiilHiiiin nf ilitl

Bteul ua ntl ill preoeerantra. T« dwell np-in ull Uie imiiiCHiai Irmurb of MeJical $ci«iic<< )ii iltc i>ie*

Cnal laeriliaoil blab el'iini of lh> woik lirfote m, lenl niiiion Mr. Wili-m propuii ui wilh tils triulli

Mriaiim, wmM laJ'Ci) be ■« ■||r<:eui>lr ■rrv.i-el 1( -it liia nuiurul rxi-etlrnee,^iiiiii-<J after to exK^Extvc

V<<wl<l >>e n meiLlnl taomaKe wtiiTh wr rnulil frfvl)' irquiinianii- wiin ttie juillioliigy aDi] ((■ntnii:l]l i>f

offer, bul Wf ihuuld (niii (ir.eiiijy 111 utiilic niii'niut i-uuoirMiis ■Itri-iinni ; anil we uiite nuw luiti.n ui

ttf VBcalu tJUt Jmrnal. VV> wil), hiiwii-pr i^it.k ant merely a leptiniof lii* futon* publtaaliiini.lial
mx MMW of Ibe mnre ailianl pninli Willi whieb it ' aa ealiirlf aew aBil tonrriltea volant*. TIid*'. tba

ftb<iBMBtaii-3 vrhieliinakeltUI«tHniin>auiTinp<niir(D
■■•■IlHieciuilliiiaai iieaUieaoriibeiiibieeiMriler-
Dutoli^r N>' mefe ■|)fieulalivy Virwaarr nll'iwil

■ jilai'nlii (III* iriiiuinv, wliien. iniaout ■ dtxibi, wiil,
fii a vcr> I'liig piiiinl, be aeltiiAirleil«i^il ■■ Itir vhirl

■ lanitntit uri'rii on drinuiloliiig/, Tlir pdiiriiilri <il
au eiilt|blriiril a nil mNi^u I tlj^apctuire inlr»ilaeed
Ml everr a[i|iriiprlau waaUm.-^Mk J*«r. i(*d.
#€Miic.. Oel (W1, ^^-^ 7 \J

Whola bittuey of lli« iIimiibi affnotlas iJia ibta,
wnetbei the; originaie in thai iiiaclui* m at* ib*
i»rr' iiiiuilotdltiint -f derui^nni ul ■>( inieiixl ••!•
ffiti, II br*<ti^bl awlrr □'>tiep, hiji3 -.hr bonit iBi'luilei
ii iHiili tif lJ>ft''<nHlli>n wliKli, 11 ■j'frail <iv( a HI tilt
pari u( itie il4-niainuf Mei)ii'alan<l!iur|{l*nl Puikolta.
gj. We can Mt'cly tfciiiDinend it to the iit.'IntiiiB
• 1 ilm bill wurt /■a Ilia iuIijki nvu> la ejtmeaec ta
llir Knitliiifi Imifiii&^e — L«idea ilulK*t TlinHi nad
llai'iu, Niieli •!*, tHS?.

Wbfa lb« irti adUioB ol ihia wuik apptnTed,

v^ L j aL«a, Rotir atcanr,

A SERIES 0KH.4TfiS>aLUSTUATINy WILSON ON DISEASES OP

j or iinmiy beauitruily execuicd ptoiei

Vontal Aaaioniy and pBibi>1ngy of I,"

I bajHliTd vuri«li«» of dlNMM, idm:

which ibirtrca ar« ex4iif>ii-lf

' I, and coiilainiBf aeouruie ro-

iiB Ui« aise ol~ nuliua. Viiat

pialea will ba roond equal lo

. TUH S.K1N ; con«aliii|,

enlofcd, pr<!nefliiiu[ tba 1

bret«nU1loll»-6/ BMUt I

in cloib. $i Mv.O

Id biPKuCy ol ijtawin^ and Bfc-nrary aitd itiiiih of colorin
anylbiiig ul ih^ilml aa y^jji^^iod iu thm cpuntty.

Tb* [ilaiea hf wnieb'Mi^ editlou iV nceniapiisleil
leave aathar-Mte deaitaiij ao lar *i^ eieelleaca of
delinealnw ana pfHlMj BM^rne^ ft illudralion are
aoaorraod — Jlbrfiea<M^«t(uaJ Htritte.

Ollti'v- plate* It laiinpMi bit tuineak lOOhlglilj
The r«pi<v:ikUUwi^ribe\tTioui fdniiiof caunc-
OuidlMuar nfr (lUtdarty adfurale, aad the colur-
]B| cirrcil* aUntiit lAiTtailic we haVD MM Wttb !■
piiiat of ilrliuiry aiii) bniati.— S>itU4 oad Fonifn
M»dK»l ««e..w, ' X,,^^

Also, ibe TEXT and FLATK3 dune up m om baadi imrWiUM, «Xlra lAath, price t? M.

ar TtiK una Auriioa.
THE DISSECTOR'S MANUAL; or, Practical and Sureical Anatomj?. Third
Anerieaa, fna Ute toM r«TiM:d and taimtftd Kn^irh ednLoti: ModtSid aaii MAsna%«l^>«^
WiLuaM MoiTT, H. I*., Ucmoortfaiot cif Autora^ « \bK Uwv-rer^wi lA »«wiwfj\iwa'». V»*o»

Wb ban altaadv extirtaaed oai hi(;b apprrrialinB
of Mr. \VlJbi(«'fSfi'*il*« OB Ularaaea of Hit »itiB.
The ptam abu emnpiiaod te a lajiaiati vtiluiiia,

whicb we oeuaM aJi tbeaa wbo po**«ai tbt leii la
Mrobaaa. ll la a baaattfal qiaolBieii iifeiniiir priul-
ia(, aod tfikvawtaeauiloaB af Uaa ranoui fiwua of
akiB iltafaaaat*^ fatthfal aa ia |Kj*a>tile la plataa
of Ibaitib^ffMMB Ji«d.e*d««rc. J«*nui,Aanl
S, IBM. ^^^

BLAMCHABD 8E LEA'S MKVtC&L rVBLICATIOirS.

WILSON (ERASMUS) F. R. 8.
ON CONSTITDTIONAL AND UKUKIHTARY 8VPHIU8, AND OX

STTHILITIC KRUPTIUN^ In me ■amll uciavo v»lumif, nxim <;lr.ih. brauliftilly prwlrd. wtlk
ftfuri<x<iui*'il«nolar«i}|iliilo«, prmeniiiig more Ihuu Ihirly rarcelic* ulaj-jituliliL-crufMiav*. tS Sfi

fiEALTIIY SKIN; A Popalar Tro^tisw on tb« Skin mad Hair, tbeir PreMrm>

UoitKod MBna9»m«nI. S«ooad AmencBii, from tb« fourtn l.ondoA wdilioo. OnciuMiTaliiDe,
rayvi 12iiio.,«zt»eluib, ol nlNiiitSW pa^ii witli DumuruaiiLliutrmMiKi. it 00; fmpet wnwr,
73 osatv.

WtNSLOW IFOABES), M. D., D. C. L., be.
OKSCUKK I)ISEA8t:S OP THE BRAIN ANH UISOHDKaS OF TTTE

INIt; Ikeir mcipi«i>i Sjrnntuci*, P«ihoUiin'- L^aenofW, 'J*t«aiai«nt, Mul I'rofitaylKkii. Itt

tandMflM iNtaro vuiuoK, of acerly tWQ fmfcv*. %3 DO,

W«e(o«(< >hU liiiitf Mtiil ne««antily rrty iaipcrff«l Patkotagf. It MMxplateljr eilwMUl Iki> wntifrt^

■ntily rrty iaipcrff«l
■niicc I'f Dr. %%'lni(nwli trMI uwl clnulMl werk,
bf •Jipiniiiiitl our «iioTl<Flia«i lliai ii u loug aluca au
tinpurcual itiitl bonulifiiJIy wrilUn % v»luinB laa ia-
•w«d (ii-m llir Qrillah OuillcaJ plt^t.—OmUim tSij.
J*r>ii. J,il| -JA, 1^«0.

We bnoiallr Srlivvflhti to I>f lbs boat boot of [)tv
aauaoB.— ^AU••lr'* J£jira<(. July, IbM).

The 'atlcr (Million ••! Dr. WidiIdw'b wi>rk ii ax-

duaivtlrOcTfced w ibe coMutcmioD o( OBwbnl

tciatisf WfR.iibiil jiiyehical i>ti(ac«i*
UDnoticed in ntfrtmcf !<■ ihcMMiai

Utialiiiiy iif ri'iilirnl diara*a, tl la iir>|i<
iivciciitc Ihe frfitifiU likfjy lii leaull (nam
prtain] nf t>> lVia*I>iuf'i raloaulf ■«■:
Icrriling W'lik —t.awUrm l.«m»i, June », I

It <i»«tain> an liBnanaie mmm f>r MmtnMvm^^
SrH.*»4 F»t. iL^,-C*ir. Btriitr, D(L UOO

WE9T (CHARLES!, M. D,,

Avuaamfoi tnmad licrlaTBroB MUlwirery at Si. HarihuluiiHw'a Rn^ilial, Pli}*kMS !• Ult Bnafllkt fW

Mint Ckil4rrn,&o,

LRCTITRES OX THE PISEASRS OF WOMEN. Second Americao, from Um
McraiJ I..ondo«i edttion. lo uno liaudfonie uouvu vulumi;, txxn. clo(b, of ibuul SUO iMrn;

*«* G*r[iilFiii)*ii who icwiT«i{ lb* flrai portion, u iaauMl in iIm " Mediral K«wa mnd LibruT," cw
nuw ouiiipleU* Itipjr oupiea bjr ptiicruiing I'ail II, b«wg pags 3U0 Ui evil, Wilb IiuleX, Tlil« nuUtsr,
tea., Sva., dt»h, prim tl

Wc n«al DOW e«a( I ud« thla baaii ly wrlltea akcleb
Vich Ih^ rtinfiiJpnl ■Kiirranr* lit luir rtoilrra Ihai Ilia
Woik will welt ic|iii) pefuul. The ruDwifutiitiia,
I>aMBtJ>liiiic,|irai?'icat pU; iifiiaii iia|>[iar<iuU'ii '*•[]
pfB,i—Jf.Y. Journal a/ jlt«(ff<in«.

Wa know orno iiaaiiac of Ihe Itiod an eafnpleU
MAjralaoconjMCI.— C'AiMifa IUm4. Janr.

A fajief, mtire bi<Dpa(,iii'>r<; rarnrat, and more ta
tlsblt iDVtiKKUtor q( tli« niHiiv ducHari o( wi<niea
■od cliildrrii la not 10 lie Tuuiid in uy rtfiuitr]ii~
CstttlUfM Jtf«4. tutd S»fg- Jptmal.

W« have I'l aa)-a( It, tiriellr aMl daeliledly, tiMi
ll ii ilii> l>f*l Willi >in ihr lUiiiMi in aujr lanilaaKg ;
•nil fliai IL >uiii|ia [|r. \V«at na Ihe /act It iirimttpt
oT BritUb vli«l«lrt« BUtlKifa — Kitmt. M*<i Joum^

We gkilijr HtonmtM bit Lmum a* la lli* bub.
aal itrgiixr luaiinclire in all who ars IMMMUA IB
UlMleliiv |)(ai;lloo,— ^a*4aa I.i*a4<(-

Iloppy inniaaiir-i' - ' 'itnaer, akd ma4«nt«
in bi* uprcaaiua : c aailiKi la a aunn^

iruuiicr B^il Bi>' ,1.1, ami kia ^txib t«

wonky oi i^t Gauuxit):!- ,>ii<T> in whick iihaaa^
pasraO — Yirgiina M'^. Jamnmt,

Wr muit lake Ivive at Di> Wenl'a i-Eiy aii
wnfk, Willi iiur Finn mrsdai ill* at ibn «t|i
ii* iirle.and the (•(■■Iry bb^ labriely vf
of wbifu 11 givca cruleaoc-->£,Pwla* M*4

5>ninit JcdfiBMil and gnad natiic pa.
altal>ic( 111 Uir UwJi, CiuM ilapcniul Wi

lived vRMiiti] aatiainctw. J>Wft» ^MWf

ir TUI SAMK AI7TH0E. (^1(4/ lMU«d.)

LECTUUBS ON THE DISEASES OF INFANCY AND CHILDHOOD.

Tliinl Ainorican. l>om ili<^ fourih enlurgrd mid iinpruved LonduB editioM. In one JnnM>-ifiM
Q«tuvo*ii|iiu>«,exiraetoiti, of nboiii fti buadrvJ ami M\y (-Mig**. #176.

Tko Ibicr I'liiDin cdi liana of tfae wvik nnw Iwdrrn .diinar* u oiaiia In nolicc al1(i«rihfli_ Bat ihoaa
u* liava pUcfkl iiie auihor in in* (••rtinL-»i ,«uk nl wliv Imow anylliiMg or ' . i mulitjiin nf

IJiciar |>li) airiitn* wliii havcccvi'lrJ ji>c<'ial ullrjilMin iHrUialiira will rratiily ••■ -. .lajiii In ntai

tu iBc dJ*«Bi>r* ol early III* Wr uiivnjpt tu aaa- it> iinr-ua»ii>le tucteot ni' r ■ < ,i taiiar,

I)ai* uf tlMx-itili'iDflial nio) ipfrr Ilir irailur [n ai.-iiir ' (be amxii'liriii iif Si. |[Brlli"iiiri> « '» bat
ihT tbcctiBpicii lu wliivli (liv lor^ealaduiiiuaa hare amgla T'-iaiiM. Tke leeiura (XVI.) <tpa

bvcc nia<lr — ihiwir m Dljililliriia. UiM-nltr* oT (be uC Us Miad m ssilarca la an nOmrataa i.

Miad.BDd IVioey. tariaaWoca — Bia pifiui iliat the liia viiaaiH ttia laVi kk(»rni«liUB •«■■**} i4 ta

viiiik ia ic<jly ■ new (ulilii'ii , iml a nicic rspriiit. Leutum i<t l)t. ChaiUa Wxa.— jL

In iltpfciTui. slikpc 1( Will be i<>uu<l ul Iht Htntlcat UcL tJi lt4if.

lK*ail.)e «.(v.« i« iheri-Fry.ttavpra«i*s.if Bise. gi,„ ike nprenrnBCti "f Ibe Aral «!iil,«,,n

Lwidoi.. i)te (0, It^B. d«o»l^t •" '«-l. wkanJa ina l«<wiiMal 1

All inniitt ciiii*tit> led, Ibi* bnnb ol Dr Wnat i* fivunitfl on aix buBdied ubasrvaitiHui, anil
by fat the iirat irnauaplniiui lan^ongs »f>% lat'h dmiaDd eiffXT dnMCUcvBiaBdaMaiiAcaaB
Mudiliralii.Dt ul tnuil-id aritiw uud diH (R sa an t««ii lliDUaawl ■-"■I'lxn ■>wv r-.,-.^ .,„•..
wKatatPd w'^TD we iiava id. It liKur lliol II c<.>nliEHa ilaelf M> inch cl|bl)-'elf 11 .
diaiiiUers ai fumr wiibia ihe |iri>viiKo uf ua ^Ay. ' urarly lliirti ... ". — i..

aiciBai,aadcT«a wiib icMwet m iiwae It lauacqual ! pact IwiLlj )tar*, MBVi . nia tare.

na retaiiif imuuiaiiiB* ui cuatiilcriiiivn, an^ Boiat \Biilitk Uiil. J'vaiiaiiJ, 0>

KT TUB BAUa ArTUOK.

AN ENQUray INTO THE PATHOLOGICAL IMPORTANCE OF Ut/31

ATION Ut' Tlt£ us I'TliKJ. U une MM ovUvo volume, mUm cUilb. fl 00,

HrjUTKU KA1> 0» TBE CAV«V» k1«^} tVLf^UT. v ««<«»« kAWtvau Cdltmi.

1« ta.V«t.\u>0>,n-**^- V *<w.

•

LANE MEDICAL LIBRARY

To avoid flue, thla book should be returned
on or before the date last stamped below.

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "A treatise on human physiology"

See other formats