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Full text of "A course of medical studies : containing a comparative view of the anatomical structure of man and of animals, a history of diseases, and an account of the knowledge hitherto acquired with regard to the regular action of the different organs : a work chiefly designed for the use of medical students"

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Palpitations of tlie heart . . . . . . 2 

Convulsions of the larynx ., . . . • 3 

Thoracic cramps ....... 4 

Asthma . < . . . . . . . . 9 

Spasmodic affections of the oesophagus ... 10 

Rumination . ... . . . . .12 

Hiccup 13 

Cardialgia sputatoria . . , . . ,15 

Gasti'odynia. Colic of the stomach . . . .1(5 

Intestinal colic . . . . . . . .17 

Metallic colic. Colica pictonum. Rachialgia metallica 28 
Convulsions ........ 34 

Trismus. Locked jaw .,...• 35 

Opisthotonos . . ib. 

Emprosthotones . . . . , . ,3(5 

Tetanus 40 

Hydrophobia . ib. 

Epilepsy . . . . . . . . 52 

Vesanic affections . . . • . . ,53 
Hypochondriasis . . . . . . ,56 

Hysterics ........ 59 

Nymphomania ....... 62 

Satyriasis . . . . . . . . .63 

Melancholy .06 

Mania . . , • ib. 

A 3 Different 



Different forms of mania 

Page 70 

EASES . . . . .80 

General considerations on the development of diseases . 82 
Development of diiferent phlegmasiae, and their termina- 
tion . . . . , .85 

Phlegmasia from vi^ounds , . . .86 

Phlegmasia from a prick . ■ . . .90 

Phlegmasia qf the serous membranes - . . • 9^ 

Phlegmasia of the white fibrous tissue . , .98 

Rheumatism . ' . . . • ' 99 

Catarrhs . . , . . .104 

Cutaneous diseases . . . , .108 

The itch ... . . . 109 

Glandular tumours . . . ..112 

Scrophulous constitution . . . .113 

Syphilis . . . , . .114 

Syphilitic blennorrhagia . . . .11/' 

Scirrhous tumours , . . . .120 

Phlegmasiae of the bones . . , .124 

Mortification of tlie bones . , . ,126 

Eruptive fevers . . . , .133 
Simple intermittent fevers .... 139 

Pernicious remittent fevers . . . .142 

Simple and pernicious remittent fevers . .148 

Comatose affections . . . . . 152 

Astlienic affections . . . . .156 

Of convulsive and vesanic affections . . ' . 158 

General considerations on nervous affections . . 159 



Action or the brain and nerves 

. 177 

. ib. 



Reciprocal action of tlie brain and vessels . Page 177 

General disposition of the cerebral system . .1/8 

Different sensibility of the parts according as they derive 
their origin from the encephaion^ its rachidian 
prolongation^ or the ganglions of the trisplanch- 
nic . . . . . .183 

Life and health result from tlie regular distribution and 

proper employment of the nervous action . 184 











Life maintained by the action of stimulants 

Of^the different sensations 

Action of the bones . . , 

General disposition of the system of the bones . 

Connection and structure of tlie bones . 

Their development 

Coloration of the bones by madder 

Luxations ..... 

Action of the muscles . . . 

General disposition of the muscular system 

Conti'action of the muscles . , . • 

Muscular force 

Dexterity and agility of motion acquired by exercise and 

the force of habit . . , . 

Station and progression 

Of sensations .... 

Action of foreig^n substances on our or^^ans 
Action of the atmosphere 

How the organization retains its habitual temperature 
Action of cold .... 

Action of heat . ... 

Action of light . . 

Action of electricity . . , . 

Action of humidity . . . , 

Reciprocal action of foreign substances on our organs, 

and of our organs on these substances . 
Foreign substances tend to combine chemically witt our 

organs .... 









All the organs make an effort to digest and absorb all sub- 
stances suited to them and to reject others Page 212 
Aftei" birth the first irapressions and the first wants give 
rise to a general disorder which produce tlie first 
painful sensations . , . .210 

Inipressions produce livelier sensations according as the 

nerves affected proceed directly to the brain . 217 
Fqi"eign substances produce a change of state in tlie or- 
ganization by their contact with the nei'ves of 
the partS;, and not by tlieir absorption and pass- 
ing into the blood .... 219 

Eecapltulation of these observations . . . 221 

Okgans of the senses . ... 223 

These organs receive all their nerves from the encephalon 

by a very short passage . , . iK 

Sense of touching . . . . . , ib. 

Tissue of tlie skin . , , s . ~ ib. 

Sense of touching belongs to the whole skin . . 224 

Sense of tasting . . * . . . 225 

Sapid bodies . . . . . .226 

Sense of smelling ... . . . ib. 

Of odorous bodies . , , . . ib. 

Sense of seeing ..... 229 

Progress of light in the eye . . • . 230 

Nature of that. sensation . . , . 234 

Strabismus .. . . . . . 239 

Blyopia . . . . . . 240 

Presbyopia . . . ... 241 

Sense of hearing , . . , . 244 

Nature of sound ..... 245 

Its progress . . . . . . 246 

Effect of music . , . - . ' 249 

Uses of the different pails of the ear , . . 252 

Deafness . . ■ . . . .254 

Simultaneous action of the organs of the senses, and of 

the muscular system from the period of birth . 255 



The organs of the senses and those of loco-mofion consti- 
tute relative life ... -Page 257 
Isfatnre and development of sensations . . 258 
Of renewed sensations ; in what manner tliey are renewed 2@l 
Of the combination of direct with renewed sensations 27 1 
Development of the intellectual faculties , , -.- 273 
Action of the system of digestion . . 282 
Of hunger and thirst ..... 283 

Mastication . . . . . . 2S5 

Deglutition , , . ' „ . ', 2S6 

Digestion of the aliments in the stomach . . 287 

Digestion in the duodenum .... 288 

Action of the bile and of the pancreatic juice . . 289 

Absorption of the chyle . . . . 2p2 

Phenomena which result from derangement of the gastric 

. system . . . ' . • . 205 

Action of the aliments on the nervous system . . 297 

Action of medicines ..... 301 

Digestive action of the gastric organs on the aliments, 
and simultaneous action of the aliments on the 
gastric organs . , ' . . 303 

Action of the organs of circulation" and ke- 

spiration . ' . . . . 307 

General progress of the blood , , . ib. 

Contractile force of the heart and arteries . . 308 

Of tlie pulse . , . . . . 309 

Termination of the arteries and origin of rhe veins . 310 
Phsenomenon of nutrition is effected between these two 

orders of vessels . . , .311 

Nature of this phaenomenon . . - . ib. 

How the elevation of the tempefature of the blood results 

from the phaenomenon of nutrition . , Zl^: 

Keturn of the blood by the veins "and the lymphatics , Z15 
Progress of tlie blood in tiie veiiii . . . ib 

Of the lympatic vessels .' . . ,310 

Change which" the lymph experiences in the lymphatic 

glands . , . * .317 



Theoiy of the humourists . . . Page 319 

Exper'iments which prove that it is erroneous - . 320 

The blood is freed from its excess of heat by evaporation 

of the cutaneous organ . . . .321 

The blood freed from its excess of aqueous parts, and of 

different saline substances, by the urinary passages 324 
Phenomenon of urinary secretion . . . ib. 

Of the colour which the urine assumes after the use of 

certain substances . . • • 320 

frspection of the urine in diseases . . • 323 

The venous blood repairs its losses by the product of di- 
gestion . . . . • 331 

Venous blood frees itself from tire materials of the bile in 

its passage through tlie liver . . . 332 

Peculiar phsenomen a of tlie secretion of the bile . 333 

Erroneous idea of the bile passing into the blood . 334 

Analogy of the function of the liver witli that of the 

lungs . ..... 335 

Passage of the blood into the left side of the heart . 336 

Its passage thence into tlie pulmonary organ . . 337 

Changes which the blood experiences in its passage 

through tlie lungs . . . .333 

Changes which the atmospheric air experiences in respi- 
ration ,..,., 340 
Different theories ojn respiration . . ■ . 341 

Of the different kinds of asphyxia . . . 345 

Of the movement of inspiration and,expiration — forma- 

tion of sound . . . . 34g 

Of the vocal organ in birds' . . . , ib. 

Of tlie vocal organ in man .. . . . 350 

Action of the organs of repkoduction . 354 

Of reproduction in general in tlie different classes of or- 
ganized beings . . . . ib. 

Eeproduction in the mammalia . . . 360 

Kutritiv^e apparatus of the germs in tlie different classes 

of or_a"iz-d beings . . , , , 362 

Of crossing biccda i . . . . 3^0 



Of reproduction in man 


; Page 372 

Of puberty 


. ib. 

Of fecundation 


. 373 

Development of the foetus, and of its 


.- 375 

Of parturition . 


. 376 

Secretion of milk 


. 377 

Derangements of that function 


. 379 

Various errors on this subject . 


. ib. 

Of the different races of men . 


. • . 381 

Effect of crossing the breed 


. 383 

Recapitulation of the knowledge acquired in regard to 

the organic functions . 


. 389 

Conclusion , 


. 433 





157. The (yftems of organs, which are fafceptible, 
as already (hown, of different degrees of weaknefs, 
and which in this ftate exhibit various affedlions, 
may be alfo exalted or deranged in their a6lion, fo 
as to perform only with trouble and diforder the 
fundlious affigned to them. In this cafe they 
prefent phasnomena of difeafe exceedingly nume- 
rous and varied. 

158. The heart exhibits fometimes in its mo* 
tions a very remarkable acceleration. During its 
rapid and irregular pulfations, it often ftrikes the 
ribs with fuch force as to produce a very fenfible 
fioife : this is frequently found to-be the cafe after 
violent running/ 

voL/iir. B The 


The circumflances capable o{ producing palpi- 
tations of the heart are of two kinds : 

One kind depend on an organic alteration of 
the heart, or of the large veffels ; a dilatation of 
thefe parts ; and on all caufes capable of exciting 
any obftacle to circulation. 

The other kind arife. merely from a derange- 
ment ip. the nervous a&ion of the heart. The 
latter |r§, frequently remarked in individuals who 
have fuch a ftate of irritability, that, if it does not 
alone produce palpitations, it increafes, in a lingu- 
lar manner, the influence of the other caufes cal- 
culated to excite them. 

In the cafe of palpitations which arife from an 
organic alteration of the heart, there is no hope of 
a cure. The paroxyfms of thofe only which de- 
pend on a derangement in the nervous action of 
that organ, can be diminifhed or retarded, by re- 
moving the caufes capable of accelerating the cir- 

When they arife only from great irritability of 
the nervous fyflem, they require the application 
of general means fuited to all kinds of convul- 
fions. FaJpta lions of the heart, 

159. In fome individuals very much difpofed 
or even fubje6!; to convulfive movements, and par- 
ticularly in women, there fometimes fuddenly 
comes on, for a quarter or half an hour, an im- 



poflibility of articulating, or at leaft with theufual 
tone and precifion ; the perfon makes fruitlefs at- 
tempts, as if to expel the mucous matter which 
obftrufts the larynx. Sometimes an involuntary 
and incoercible flow of words takes place; an 
emiilion of the ftrangeft founds, paffing abruptly 
from grave to acute, and vice verfa, with aftonifh- 
ing difcordance, and fometimes refembling the 
cries of different animals*. The voice however 
js at length, fometimes, redored without any ex- 
cretion. Convuljions of the larynx. 

Impediment or abolition of the voice depends, 
in other cafes, on palfy of the larynx. 

1 60. The thorax is the feat of a peculiar affec- 
tion f, which announces itfelf by a fenfation of 
conflri(?tion, rather incommodious than painful j 
pain is felt along the ilernum for a greater or lefs 
extent ; and in general there is experienced, at the 
laTHii^ trme, in both arms, but rarely in one, a 
cramp towards the infertion of the great pedloral 
mufcle, or in the fore-,arm towards that of the 
round pronator. The paroxyfms take place in 
confequence of caufes exceedingly various, and 
they even vary much themfelves, in regard to the 

* See Portal, Mimoires de la Soclete Medicale. 
t London Medical Journal, vol. v. — Macbride's Introduftion, 
£« the Prai^ice pf Medicine. 

B 2 intervals 


intervals and to the duration. Sometimes they 
laft an hour or -two ; in fome cafes their return has 
been prevented by the ufe of wine or opium. 

The ftriking influence of moral afFedlions on 
the returns of this difeafe-^ its long duration, 
without any other derangement of the health ; the 
ftate of the ftomach ; the relief almoft always 
afforded by the ufe of corroborants^ by riding on 
horfeback or in a carriage, by varying the occupa- 
tions and diverting the mind, indicate that this 
affedlion, which is merely nervous, does not arife 
from an organic alteration, and that it has its par- 
ticular feat in the mufcles of the thorax. It exhi- 
bits fome analogy with chronic rheumatifm. Tho- 
tacic crani'ps- 

i6i. Among women, but more frequently among 
men, efpecially when very corpulent, is obferved 
an affe<51ion which is often hereditary, and which 
feerns to have its feat in the different parts- of --'Ihe 
organ of refpiration. 

This affeciion comes on by paroxylms, and ex- 
hibits a pretty regular progrefs. The patient, 
during the whole day which precedes the paroxyfm, 
experiences great agitation, a flight headache, hea- 
vinefs in the limbs, and a fmall degree of oppref^ 
iion at the,breaft. Some hours after dinner he 
becomes fubjecl to great oppreflion, accompanied 
with a fenfation of plenitude about the ftomach, 



flatulencies, difienfion of the epigaftrium, and 
erudation of an.infipid matter. On the approach 
of night a httle hoarfenefs is felt, with a conftric- 
tion of the bronchi^ and of the tracheal artery; 
during night, a heat which will not admit of the 
bed-clothes remaining on the bread, and a fort of 
convulfive cough. There is no expedloration, or 
it conlilts of ferous matter in very fmall quantity, 
TJie fenfation at the ftomach is lefTened by cold 
beverages, and particularly by water. 

One or two hours after midnight the paroxyfms 
feem to commence by an increafe of indifpolition j 
refpiration, exceedingly difficult and flow, is per- 
formed wiih a fort of hoarfe, hilling noife, and 
renders it neceflary to affume a vertical polition. 
The diaphragm feems to move only with great dif- 
ficulty, and to be drav/n back into the breaft by 
the mediaftinum. The patient experiences a fen- 
fation of conftridlion in the lungs, and imagines 
that thefe organs are contrac^lcd and pufhed to- 
wards the uppei* part of the thorax. He makes 
violent efforts to enlarge his breaft, and is incapa- 
ble of coughing, fpitting, or fpeaking wiih free- 
dom. He experiences exceffive beat ; the pulfe 
is quick, clofe and unequal ; the feet and hands 
are cold; the face is fometimes blackifhj the eyes 
fparkle, and difcharge involuntary tears, which 
fomctimes tinge the cheeks yellow. The lips. are 
difpofed in a form as if about to fack. 

B 3 Sorae- 


Sometimes the patient gets up, places himfcif 
at th"e window, whatever be the feafon, and refpires^ 
while ftanding, with more facility. In fome cafeSj 
the diftenlion of the abdomen feems to decreafe; 
the difficulty of breathing is leflened ; and there 
comes on an ample evacuation of fascal matters 
and of flatulencies, which affords rehef. 

In general the fymptoms continue for feveral 
hours, and even fometimes to a pretty late period 
in the morning. After a little fleep, however, 
refpiration is lefs laborious; the acft of fpeaking 
and the cough become lefs difHcult. Sometimes 
a mucous expedloration takes place, and the re- 
mifTion is then always more fenfible. The urine 
is lefs abundant, more highly coloured, and gene- 
rally fedimentous. During the whole day the 
patient experiences a confi:ri(9:ion at the breaft, 
and a difficulty of breathing when he afTumes a 
horizontal pofition, or makes any movement. After 
dinner flatulencies take place ; he becomes drowfy 
in the evening, and the difficulty of refpiration 
gradually increafes. Sometimes, however, refpi- 
ration is pretty free, and fleep tranquil for a part 
of the night; but from midnight till two in the 
morning the patient is fuddenly awaked by an at- 
tack of a fecond paroxyfm, fimilar to the firfl:. 

The paroxyfms are thus continually renewed for 
four or five nights ; expe(51 oration daily increafes 
in the morning, and the remiffions are propor- 


tionally lefs fenfible. Sometimes the paroxyfm is 
preceded only by a little drowfinefs towards the 
evening. In this cafe it continues not more than 
two or three days, and when the patient is up he 
expedlorates a ferous matter. But in the cafe of 
the greateil intenfity the difeafe continues for four 
or five days, with the ufual exacerbations every 
night. The expedloration does not begin till the 
third or fourth day ; at firft it is in fmall quantity, 
becomes progreffively lefs vifcid, white or yellow- 
ifh, and is fometimes marked with bloody firiaB. 

A firft attack of this difeafe gives reafon to 
prefage, in an infalHble manner, periodical returns 
during the remainder of life. Sometimes thefe re- 
turns feem to be produced by great heats, and 
violent emotions ; by certain odours, fmoke, fnuff^ 
duft, &c. and by every thing capable of abating or 
accelerating the movements of the breaft. 

Some individuals experience more frequent ac- 
ceffions in fummer, and particularly during the 
oppreffive heat of the dog-days ; others are oftener 
and more feverely ajERidled in the winter. But at 
this period the difeafe, for the moft part, is ac- 
companied with a catarrhal defluxion of the bron- 
chia?. In all cafes, however, the patients are 
fpeedily afFed^ed by fudden changes of tempera* 
lure *. 


* Floyer, who kept a very exa6l journal of his difeafe for 
fcven years, relatcSj that thsfe paroxyfms were more violent, and 

a 4 of 


Some find themfelves better in the air of great 
cities; others in that of the country; but al- 
moft all prefer the dry free air of low di{lri6ls to 
that of the mountains. Damp, foggy air in ge- 
neral is prejudicial to them, as well as' damp habi- 
tations in marihy places. They are fatigued by 
heat, but can very well endure cold, and even a 
pretty intenfe degree of it ; which fufficiently 
indicates that the atmofphere beft fuited to them 
is always that moft abundant in oxygen^ little 
charged VN^th moifture, and which is not fubjefl 
fo too great or too frequent changes. The infpi- 
ration of air with an increafed proportion of oxy- 
gen may be ufeful to them. 

Light animal food and vyater are much better 
fuited to fuch perfons than flatulent aliment and 
fpiritous liquors. Riding on horfeback or in a 
carriage, and fea voyages, afford relief. 

Emetics fonpetimes have appeared ufeful in this 
affedtionj efpecially when it is catarrhal ; when 
given before 'the acccfiion they fometimes pre- 
vent it. 

This affe6lion, in general, produces no derange- 
longer duration, in fummer than in winter, but particularly in 
the month of Auguft, and that the expectoration then became 
thicker. The return of the paroxyfms took place for the moft 
part in the courfe of the three days preceding or following the 
full or the new moon, and fometimes alfo towards the quadra- 
tures.- — Van Helmont alfo obferved a relation between the par- 
oxyfms and the phafes of the moon, 



ment in the reft of the organization ; md there 
are inftances of people who have been fubje6l to it 
fifty years, without any other inconvenience. 

The acceffions, however, rarely recur often, for 
a confiderable length of time, without producing a 
general emaciation. In fome young perfons it has 
been feen to terminate very fopn by a pulmonary 
phthiiis; fometiraes alfo it produces hydro-thorax. 

It is probable that the perturbing fyftem of treat- 
ment is that beft calculated to efFe6l a complete 
cure of this difeafe, efpecially in the commence- 
ment, and before the paroxyfms; by exciting either 
in the ftomach or in the tides of the thorax a repeat- 
ed and continued irritation, capable of removing 
that of the organs of refpiration, which produces 
the fpafmodic or convullive fymptoms of ajlhma, 

162. In perfons fubjeti to convulfions, and to 
all thofe caufes by which they are produced, 
there comes on foaietimes by paroxyfms an affec- 
tion of the oefophagus. Deglutition is difficult 
or impoilible, and this fymptom is accompanied 
with a contraction or ftiffnefs of the tongue, of the 
larynx, and of the whole neck; a lufFocating con- 
ftraint, and a fenfation as if fome body had ftuck in 
the fauces : fometimes there is alfo a tranJitory or 
permanent aphonia. 

In other cafes deglutition at firft appears to be 
free, but the fubltances fwallowed flop at a parti- 


cular point of the cefophagus, and for the moft part 
near the ftomach. Warm liquors pafs with more 
freedom than cold ; the patient at the fame time 
experiences a pain along the fpine, naufea, frequent 
efforts to vomit, flatulent eru6iations, and throws 
up limpid mucus with the matters which have been 

Sometimes the two feries of phaenomena here 
enumerated are obferved, either limultaneoufly or 
with conflant or irregular alternations. In this 
cafe, the patient experiences a fenfation as-if fome 
body obflrufSted the osfophagus ; and of flatu- 
lencies afcending and defcending, without eru6la- 
tion taking place. Thefe varieties feem to depend 
on the different parts affedled. 

In general, thefe affections come on by par- 
oxyfms, and vary very much in regard to the in- 
terval, ftrengtb and duration. At the fame time 
there is often a coldnefs in the extremities of the 
limbs, and particularly the feet ; fometimes trem- 
bling, fuppreffion of the itools, abdominal fpafms, 
palpitation of the heart, &c. Th.hfpafmodic affec- 
iio72 of ihe cefophagus is very often accompanied by 
the other convulfive difeafes. 

There are other obftacles to deglutition, which 
arife from, 

ift, Atonia or palfy of the cefophagus. In this 
cafe, folids pafs with more eafe than liquids {Fahr, 
de Hilden). The latter run along the larynx, and 



are fent back, through the noftrils and the mouth 
with danger of fufFocation. This frequently takes 
place in the advanced ftage of continued perni- 
cious fevers. 

2,d. From an acute phlegmafia : anginsc, &c. 

3d. The prefence of fome voluminous body flop- 
ped in the oefophagus; a Vv'ound, ulcer, tumour, or 
excrefcence in its fides ; a confiderable fwelling 
of the glands of the neck ; a fcirrhous Hate of the 
cefophagian orifice of the ftomach ; a luxation of 
the OS hyoides. 

163. By a convulfive contra(5lion of the fto- 
mach, afi^fted by a fudden (hock of the diaphragm 
and of the abdominal mufcles, the matters con- 
tained or affluent in the ftomach, the duodenum, 
and fome other inteftines, are fomctimes thrown 
up in the adl of vomiting. 

This difeafe arifes from a nervous affedlion, a 
phlegmafia of the ftomach, dift^erent irritants in- 
troduced into that organ, or which develop them- 
felves in it. 

This aifedlion is only lymptomatic in fome 
acute difeafes, and in fome phlegmafia; of the ab- 
dominal vifcera, &c. It is often produced by a 
coritra6lion, a fcirrhous tumour, or a cancer of the 
pylorus and of the duodenum, a ftranguiation or 
ftridlure^ nodofity, intus-fufception or adhefion of 



the inteftines, and by every obftacle to the free 
courfe of the matters in the inteftinal canal, &c. 

But the vomitings often appear to be entirely 
analogous to convulfive affe6lions, and in that 
cafe may fometiraes be exoted by the influ- 
ence of the imagination. This influence refults 
from the afpe6Vof the vomiting, and from all thofe 
pbje^ls and circumftances which may recall the 
remembrance of it. In forne perfons it may be 
produced feveral times by an accidental caufcj 
and then continue by the force of habit, notwith- 
Handing the abfence of the caufe which at firll 
produced it. It then always exhibits periodical or 
son'tant returns, 

564. Peyer relates feveral examples of perfons who 
liad the faculty of bringing back into the mouth 
the aliments they had fwallovved, in order to maiti- 
cate them at lei fa re {De Meijcologld). In fome 
individuals this habit, initead of being an incon- 
venience, appears to be agreeable, and to get rid of 
it, nothing would be ncccfTary but a determined 
refolution. In others, it is entirely involuntary, 
and feems to arife from a real convuliion of the 
ftomach, irritated by the prefence of aliments in- 
troduced too fiiddenly, a'nd in too large quarftity. 
It is, in particular, after an exccfs of gormandizing 
that this fpecies o{ rumination \s renewed. 

165. There 


165. There is an inftantaneous and reiterated 
afFe<9:ion5 which confifts in a fudden fliock given 
to the bread and abdomen by a fpafmodic con- 
tra{5iion of the diaphragm. It is accompanied with 
an acute found, ftronger or weaker, which appears 
to arife from an exploiion of the air contained in 
the ftomach and the oefophagus. 

In certain cafes, hiccup is merely a fymptom of 
fome derangement of the gaftric lyftem, fuch as 
colic of the (lomach, the inteftines, the kidneys, 
Sec. a ftrangulated hernia : it is alfo a troublefome 
fymptom of fome acute difeafes in an advanced 

Hiccup, in general, refults from a momentary 
irritation of the (tomach, when that organ has fud- 
denly received too large a quantity of aliments or 
of alcoholic liquors. It appears to be produced 
alfo fometimes by an inflantaneous irritation of 
the osfophagus and of the diaphragm. 

Hiccup fometimes is really fpafmodic; and, 
without feeming to refult from any caafe, may 
continue a long time by a fort of habit*. 

Though hiccup, for the moft part, is frequently 
renewed, it is fcarcely an indifpolition. While it 
takes place, a flov/ and long infpiration, fneezing 
purpofely excited, a fudden furprife, unexpe61ed 
news, a fright, and every powerful diftradlion, are 

, * Tulplus, Riviere, Fcrnelius, &c. fpeak of a hiccup of this 
kind which frequently returned for feveral months. 



fufficlent to remove it ; which might induce a be- 
lief that in thefe cafes it is merely a fpafmodic af-- 

In the laft place, when hiccup is the fymptom of 
another difeafe, the latter alone deferves attention, 

1 66. There is an afFe^lion diftinguifhed by a 
dull or acute pain in the epigalb'ium, with a 
diftenfion or contra(5lion of the ftomach, flatulen- 
cies, eru61ations, vomiting, he. The general in- 
difpofition and ftate of the pulfe depend on the 
intenfity of the difeafe. This difeafe feems to pro- 
ceed from a fpafmodic or weak ftate of the fto- 
mach, which in many circumflances varies. The 
principal variations we fhall here defcribe. Some- 
times this difeafe arifes from an afFe6lion of the 
pylorus ; from the action of emetics, violent pur- 
gatives, poifons, &c. 

In perfons below the middle age, and in thofe ■ 
even who have not attained to puberty, but parti- 
cularly in women, it fometimes comes on fponta- 
neoufly. It manifefts itfelf, for the moft part, be- 
fore meals, by pain with a fenfation of con{tri<5lion 
in the epigaftric region ; the ftomach feerns to be 
ftrongly pulled towards the back, and the body 
leans forwards j v,'hich in fome meafure diminiflies 
the uneafinefs. After a certain time the erudta- 
tion becomes eafy, or rather there flows off a large 
quantity of aqueous liquid, fometimes acid, and at 

other a 


others perfet5lly infipid. After fome erudations 
in clofe fu€C€ffion, the pain decreares and entirely 

This tranfient inconvenience, which however 
is apt frequently to return, is in general more 
troublefome than painful. It terminates fpoota- 
neoufly ; is met with in our climates, and was ob- 
ferved by Linnaeus in Sweden. Cardialgia fpula- 

Feeble perfons, convalefcents, and chiefly wo- 
men, and thofe in particular whofe organs of di- 
geftion are exhauited by the long ufe of tepid 
aqueous beverage and aliments, or by the abufe of 
different Itimulants, are very much fubje^l to 
this difeafe, which is readily renewed by violent 
mental atTedions, ftrong fenfations, and by certain 
kinds of food. In thefe cafes they experience, 
fome hours after meals, towards the epigaftric re- 
gion, diftention or tumefa6lion, dull or acute pains^ 
with fufFocation, and great fenlibility to the touch 
in the region of the ftomach : eru6lation of acid or 
fweetifli matter then takes place, and fon:ietimes 
vomiting ; which affords relief. In fome cafes this 
flate is accompanied by a coldnefs of the limbs. 

This difeafe fometiraes depends alfo on convul- 
five affe6tions, and accompanies them. It is then 
chara<51erized by an acute pain in the ffomach, 
with anxiety, (hortnefs of refpiration, and efforts to 
vomit : Ihivering, a fudden proftration of ftrength, 



and a fenfalion of approaching fyn^ope, at the 
fame time take place. The pain, which at firft 
feems to arife from the pylorus, extends to the reft 
of the ftomach, and towards the fpine. Sometimes 
a tumour, nearly of the lize of an egg, manifefts 
itfelf a little to the right of the fternal appendix i 
eructation produces a flight relief. . During the 
greateft violence of the difeafe, the limbs are cold, 
and the pulfe is fmall and confined, 'At length heat 
is reftored, with an univerfal fweat ; the pulfe be- 
comes large and foft, and the pain gradually ceafes. 
The numerous relations which the ftomach has 
with the other parts caufe this organ frequently 
to participate in their derangements; fo that this 
difeafe, which we have often leen to be differently 
eflential, is very often only fymptomatic. It may 
therefore be determined by an irritation arifing 
from a calculus in the urinary or biliary canals : it 
often precedes febrile and gouty attacks ; it forms 
the prevailing fymptom of a variety of intermittent 
pernicious fever; and it accompanies the interver- 
fton of a great many difeafes, fuch as dyfenteryg 
gout, &c. CoTic of the Jiomach.^ Gajirodynia, 

167. The inteftinal canal is the principal feat of 
a difeafe which appears to be entirely fpafmodic: 
it is characterized by acute pains in the abdomen, 
which ceafe and are renewed at very fhort in- 



In hiiejl'mal colic ^ the pains are more acute when 
they take place towards the umbilical region, and 
ieem to proceed from the fmall inteftines. The 
patients for the moft part experience a fenfation 
of diftenlion and twitching, which proceeds from 
fome point of the inteftinal canal, and extends by 
little and little. The inteftines are in a ftate of 
conftipation, which gradually increafes, fo as to 
prevent all efcape of the flatulencies. The pulle 
is always fmall, hard, clofe, and convulfive. 

The difeafe, in its progrefs, exhibits intervals, 
very much varied, of calmnefs or limple remiffion ; 
and at its higheft degree there often come on fhi- 
verings, tremor, great agitation, extreme anxiety, 
naufea, vomiting, at firft of mucous, then of bili- 
ous, and laftly of ftercoraceous matter. Sometimes 
hiccup, delirium, convulfive movements, cold 
fweats, fyncope, &c, are obferved, and, in fome 
cales, vefical tenefmus. 

In fome individuals a flatulent tumefa(5lion of 
the belly takes place, with extreme fenfibility to 
the touch ; a fenfation of tenlion and pain in the 
ftomach, efforts to vomit, and flatulent eru6lation 
which affords relief. 

Others experience opprefiion of the abdomen^ 
a retradlion of the navel, violent contra6iion of the 
abdominal mufcles, which become hard, and ex- 
hibit their form beneath the integuments ; a con- 

voL, III. c fliridtion 


ltrif?^ion of the anus, which does not admit the 
iatrodudion of a dyi^er. In this cafe the belly- 
is not painful wheii touched, and fometimes even 
the pain is diminifhed by preirure. 

The feverity of the difeafe depends on the in- 
tenfity of the fymptoms, and particularly on the 
force of the conftipation. 

The colic generally ceafes on the appearance of 
fome phasnomena of particular affedions: fuch as 
nafal and h hemorrhoidal haemorrhagy, cutaneous 
eruption, fit of the gout^ diarrhoea, &c. pains in the 

Sometimes fever and violent heat come on j the 
pulfe is hard, frequent, and clofej the patient ex- 
periences unquenchable thirffc; and violent, con- 
ftant, and fixed pains indicate a local phlegmafia. 
(See that article.) In fome cafes, then, a fudden 
ceflation of the pain, univerfal calmnels, prollra- 
tion of the ftrength, weaknefs of the pulfe, cold 
fvveals, fcfitidity of the mouth, and frequent ly^n- 
cope, announce a gangrene. 

This difeafe is mod frequent among children. 
Old perfons, women, and weak individuals of great 
fenfibility. The habit of a flight conftipation, the 
ufe of debilitating food, fuch as aqueous, fweet, 
faccharine, flatulent, &c. vegetables, chiefly pro- 
duce a difpofition towards this afFe6lion. It may 
be occafioned by expofure of the feet to cold or 

dampnefs ; 

Convulsive affecItions. 1^ 

dampnefs > by a violent fit of paffion^ particularly 
in youth ; by excefs at table, and by many other 

It is the efFe(5l alfo of an Organic derangement 
in theinteftines ; fach as the obftrudion of a point 
in the alimentary canal by a ball of hardened ex- 
crementi {Hoffmann^ Henry de Hears,') or by a large 
calculus, a flrangulated hernia, a callofity, a fcir- 
rhus, (jCerkring, Baillou,) a cartilaginous ring, the; 
torfion of a part of the inteftines, their intus-fuf- 
ception, a ball of worms entwifted together {Henry 
de Heers). 

This difeafe is a conftant lymptom of hypochon- 
driafis. It frequently fucceeds alfo fome eflential 
afFedlions, accompanies others, and appears to be 
the refult of every caufe which produces a fudden 
derangement in the ufual progrefs of a phenome- 
non of health or of difeafe. 

It fucceeds an interruption o( the gout, men- 
ftrual and haemorrhoidal fuppreffions, &c. It ac- 
companies the exigence of a calculus in fome parts 
of the urinary or hepatic tjflem, the labour of 

dentition, &c. * / 


* The coilc which fucceeds or accompanies any derangement may 
arife from the caufe of that derangement, or from fome foreign 
caufe, and in either cafe the irritation produced ori the inteftines 
may be too ftrong to put an end to the concomitant difeafe. 
Colic may be produced alfo by every caufe which difturbs the 
ufual progrefs of a phaenomenon of health or of difeafe. But, in 

c 2 ' all 


Colics differ very much from each other, in cori- 
iequence of the different caufes by which they are 
produced ; of the feat of the pain, and the feverity 
ofthe fymptoms. On thefe bafes, however, no 
very flriking diilindtions can be eftabhfhed ; but 
there is one which exhibits a prominent character, 
and a conftant progrefs^ which renders it of im- 
portance to give a detailed hiftory of it. 

1 68. This colic, which has been known at Paris 
for more than two centuries, has been obferved in 
Germany, and defcribed by Dehaen and by Stoll ; 
it has been obferved alfo at Madrid, at different 
periods, and recently by Luruiiaga. In all thefe 
places, and at all times, the defcription of it has 
been fundamentally the fame. It has always been 
afcribed to a certain aciion of preparations of lead, 
fwallowed, or received into the bronchias. Citois 
has defcribed a colic which took place in Poitou in 
i6i6, and Huxham another, which took place in 

• all thefe circumftances, the difappearance of the firft afFeftion 
ought not to be afcribed to the tranfportation of a material and 
morbific afFedion to the inteftines, but to an interruption of the 
nervous affe6lions, occafioned the one by the other : and it is as 
ridiculous to fay that a colic is produced by the tranfportation to 
the inteftines of a gout which has difappeared, as It would be to 
aifert, that the colic which follows or accompanies fuppreflion of 
the menllrual fliix^ or the prefence of a calculus, is produced by 
the tranfportation to the inteftines of the uterine flux, or of the 
urinary and bilious calculus. 



Devonfhire in 1724, both very analogous to the 
one in queftion. The former of thefe writers af- 
cribes the one in Poitou to the four wines of that 
country j and the latter, the one in Devonfhire, to 
the cider, which that year had been exceedingly 
abundant. Sir George Baker, however, haslince 
aflerted, that the colic of Devonfhire ought rather 
to be afcribed to the lead employed in the mills and 
cifterns being diflTolved by the acid of the apples, 
and becoming mixed with the cider. Journal des 
Savans, Jan. 1768. 

This difeafe, however, attacks in particular work- 
men employed in lead manufadtories, who are ex- 
pofed to the fumes arifing from that metal; and thofe 
who drink liquors which hold it in folution. But 
it appears certain that, independently of the influ- 
ence of the lead, a peculiar difpofition or aptitude, 
which it is impoffible to determine, is alfo required. 
Stoll fays, he remarked in almoft all the patients 
attacked by this difeafe a certain appearance in the 
face and eyes, which prefented fomething maniac, 
an air of fliupor, an habitual thoughtfulnefs, he. 

This afFeftion announces itfelflliddenly, or in a 
flow manner, by extraordinary dejedion, languorj 
watchfulnefs, loiathing, a derangement in the ftools ; 
wandering pains take place in the epigaftrium, 
v/ith a fen fat ion of heavinefs in the ftomach imme- 
diately after meals; the ftools are rare, hard, and 
m fraall bits» There are obferved afterwards an 

C3 3ir 


air of intoxication, vertigo, ftupor, and dimnefs of 
iight : all thefe fyinptoms are temporary, and fre- 
quently recur, &c. 

Soon after the conflipation increafes ; in which 
cafe the perfon experiences excruciating pains in 
the abdomen, a fenfation of tearing and twifling 
in the inteftines, which is renewed at fhort inter- 
vals. The pains, which in general are fixed to- 
wards the cefophagian orifice, or the whole abdo* 
minal region, follow the diredlion of the ureters to^ 
wards the bladder; alfe£t the fcrotum, the thojax, 
and even the limbs, like an acute rheumatifm. The 
pains for the moflpart are not increafedby touch^ 
ing ; and prefTure of the abdomen very often gives 
relief. At other times, however, the epigaflrium can 
fcarcely endure the lightefl; covering. Sometimes 
the belly is foft ; but in general it is hard, dif- 
tended and uneven : the navel is turned round, 
and fhrinks towards the fpine, with hardnefs and 
tetanic contraction of the abdominal mufcles. A 
fpafmodic confi;ri6tion of the inteftines, which, 
under the integuments, exhibit the appearance of 
hard rolls, is obferved ; often a velical tenefmus ; 
fometimes a fhortening or almofl fudden difap- 
pearance of the penis; the fcrotum becomes al- 
ternately contrafted and relaxed ; the teflicles ex- 
perience a retraction, or fort of painful rotjition. 

During a great part of the difeafe the patient 
9 ^"^7 


very often experiences vomiting, fometimes with 
hiccup. He has no ftools, notwithftanding the 
ulc of injeftions or purgative draughts; or thereare 
voided only a few very hard globules, with exceed- 
ingly painful tenefmus, and a little bloody mucous 
matter. When frequent and copious ftiools take 
place, they always afford relief. 

During almoll the whole courfe of the difeafe 
the patient exhibits an aftonifhed, thoughtful, or 
even maniac air ; his mind is reftlefs, turbulent, 
impatient and fickle. 

■ At the commencement the pulfe is nearly in its 
natural ftate ; during the progrefs of the difeafe, it 
is fometimes frequent and unequal, and the dimi- 
nution of the pain is always preceded by a flight 
febrile paroxyfm, which terminates in a copious 
fweat. Towards the termination, a gentle motion, 
followed by the dejection of hard globular excre- 
ment, or even of vifcid matter, mixed with mucous 
flakes, is perceived in the abdomen. The pains 
then flowly decreafe ; the appetite is reftored only 
gradually ; the flomach becomes confiderably 
fwelled after meals ; and the nights continue to be 

Sometimes the difeafe produces a fenfation of 
curvature accompanied with weaknefs, cramps, 
or fhooting pains in the limbs, tremors, or even 
mufcular impotence, pains in the breafl, and tranfi- 
ent difficulty of refpiration. 

c 4 In 


In fome very fevere cafes the vomiting is alarm* 
ing, and produces the rejedion of ftcrcoraceous 
matters, ivith hiccup : fyncope, cold fweats, partial 
or epileptic convulfions, take place ; and if the pa- 
tient efcapes death, the pains are then continued 
forfeveral vi^eeks, with intervals of remifiion. 

In the courfe of the difeafe, paliy very often 
takes place in fome of the limbs =^, particularly in 
the arms, the handsj and in fome of the fingers, 
but rarely in the pelvian limbs, and never un- 
lefs the thoracic be affected alfo. The palfy only 
fufpends the mufcular adtion^ without injuring fen- 
fation, and in different cafes exhibits fhades ex- 
ceedingly varied, from fimple tremor, heavinefs 
and inaptitude for motion^ to complete paralyfis. 
In general, there always remains a flight degree 
of contradilityj at leaft in the flexors. In cer- 
tain. cafes a weaknefs of the voice is obferved, with 
hoarfenefs, aphonia, difficulty of refpiration, amau- 
rolis, deafnefs, &c. and various tranfient but re- 
peated fymptoms. 

The palfy may take place at different periods of 

the difeale t. 


* According to Stoll, fifteen patients exhibit only one example 
of palfy, and it is a little obftinatc only once in twenty-five 

t It was after this palfy that Dehaen obferved a deltoid muf- 
cle which to the touch prefented nothing but a membranous 
fubflance, and all the raufcles of the arm and fore-arm, with the 


in a confiderable number of patients, and efpe- 
cially thofe who have been already feverely afFed:- 
ed at different times, there arife on the backs of the 
hands tubercles as large as peafe, at firft painful^ 
which yield to the prelTure of the finger, and fpeed- 
ily refume their former flate. Thefe tubercles, 
which afterwards acquire hardnefs, and a chara6:er 
of indolence, appear generally on the attack of the 
difeafe, and fometimes even before the appearance 
pf any other fymptom. 

This difeafe varies in regard to its duration, from 
a few days, for example, to feveral months ; fome- 
times it continues years, and in this cafe it is more 
troublefome by its obflinacy than its violence. In 
general it is not very mortal. 

The body, when opened, exhibits organic alter- 
ations, which may throw feme light on the nature 
of the difeafe. Conflriclions or flrangulations are 
found in feveral partsof the inteflinal canal, of the 
duodenum, the ilium, the coscum, and the re£lum. 

fat, the ikin, the tendons, and nerves, were converted into a fort 
of pulpy ligament. At the fame time, feveral perfons aflfcfted 
by the fame palfy had the fle{h of the arm more or lefs flaccid. 
'- In the body of a man who had died of the leaden colic, Hun- 
t-er found the mufcles of the arm and hand, which before death 
had been emaciated, as v/hite as cream j the fibres of them were 
diltin6t, but drier than ufual, Zalzmann, in the Journal des 
Savaiis for 1735, gives an account of a man forty years of 
agC;, in whom a great many mufcular portions of the right th'gh' 
aiid leg were found converted into fat. 



Thefe Urangulations are often feparated by very 
ample dilatations. Sometimes thele contraftions 
difappear immediately after death ; at other times 
they continue two or three days. It evidently ap- 
pears that, on the termination of the malady, they 
are entirel}/ diffipated, fince a relapfe feldom occurs 
without a new caufe. It is, however, to be pre- 
fumed that they fubfifl, or are renewed, when the 
patients continue to be frequently fubjed to flight 
colics and hard globular llools. In fome cafes, 
portions of the inteftines are found fhrunk, and al- 
moft converted into ligament. In a word, phlo- 
gofcs have been found in the mcfentery, in the in-r 
teftines, in the ftomach, in feveral of the abdominal 
and thoracic vifcera, &c, with extravafated blood, 
echymofes, and vibices. (See Bordeu). There is 
reafon, however, to believe that thele alterations 
have no relation to the moll common cafesj but 
only to thofe rare circumftances under which the 
difeafe, when carried to an extreme degree of 
violence, brings on phlegmafia, and perhaps even 
a gangrenous and fphacelous ftate. 

It is evident that this difeafe has its principal 
feat in the inteftines, and the intenftty of the local 
lymptoms gives rife to the other remote accidents. 

The particles of lead (in all probability oxidated) 
which produce this afFedion, feem to exercife an 
immediate a6tion on the organs of digeftion in per- 
fons who drink, licjuors holding this metal in folu- 



tion. When workmen, however, are habitually 
expofed to refijire air in which fome of it is {-jf- 
pended, it is not probable that the difeafe arifes 
from particles introduced into the ftomach by 
deglutition : it is much more probable that the 
firft a6iion of the lead is exercifed on the bron- 
chial furfaces; and that it proceeds to the in- 
teftines, on which this metal feems to have a 
fpecific adion. Several fubftances exercife a fiOii- 
lar a6lion, and in a fimilar manner, on the fame 
organs, whatever be the parts which they aiFe61:. 
The vifcera of the breaft are often afFedled in this 
difeafe,iince there are obferved hoarfenefs, aphonia, 
cough, a fpafmodic difficulty of breathing, &c. 
'Two methods, which feem to be diametrically 
oppofitCj and which have been attended withequal 
faccefs, are employed in the treatment of this dif^ 
eafe. This peculiarity is worthy of notice, as it is 
of importance to the hiftory of the organization. 

169. Oneofthele methods, founded on the ge- 
neral principles, of medical obfervation, fees in this 
difeafc, as well as in others, a progrefs which it is 
proper to refpe£t ; and employs only mild and 
fimple means, calculated to promote a favourable 

The other, entirely empiric, which is more 
adive and decifive, conlifts in violent emetics, ex- 
ppedingly fi:rong purgatives, repeated without di- 



ftinftion every two days. This method is that 
followed at prefent in the Hopiial de la CharitS, 
only that a flight dofe of opium has been added. 
It is fuppofed that this method mull be attended 
withipeedier fuccefs, as violent emetics and purga- 
tiveSj the principal adion of which, in regard to 
the inteftinal conftriftion, can be exercifed only 
on the llomach, produce in it an irritation fuffi- 
ciently ftrong to remove the fpafm of the inteflines, 
which oppofes the evacuations. .But it may be 
readily feen what opinion ought to be formed of 
this method, when it is known that it is employed 
with th,e abfurd and ridiculous intention of opening 
the heJly and forcing theharrier % and whether there 
is not more reafon to be alarmed on account of 
the accidents it may produce, than to be confident 
in the advantages likely to refult from it. Stoll 
having oblerved that momentary fuccefs only was 
obtained, in flight cafes, by emetics and purgatives, 
and that the difeafe was alraofl always exafperated 
by them, had at length recourfe, in the moil de- 
fperate cafes, to opium, contrary to the advice of - 
Dehaen : he obtained a cefiation of the pains and 
vomiting ; had fpontaneous flools, and then opium 
became his purgative*. Metallic colic ^ Colic a pic- 
tomim, Rachialgia metallica. 

170. The 

* In this difeafe opium, as we have feen in tetanus, may be ad- 
ininifiercd in ftrong dofes without producing ileep. Stoll gava 


170. The different organs of motion may expe- 
rience a convulfive affection, which takes place by 
iparoxyfms, and continues a (liort time. This af- 
fection, for the moft Tp?LX\ifymptomatiCi is fometimes 

In the firft place, it accompanies fbme conlider- 
able derangements. It comes on, therefore, after 
an irritation produced in any pai"t in confequencc 
of wounds, fra61ures, luxations, tumours, &c. ; by 
tenlion, compreflion, the pun(9:uring or laceration 
of fome of the nervous reticulations; after an or- 
ganic Iseiion of the brain, the collc6lion of any fluid 
in its cavity ; an affe61ion of the uterus ; the exift- 
ence of calculus. This difeafe may be the effe6l 
alfo of a firfi: difficult menflruation, of parturition, 
of the prefence of poifon in the ftomach or elfe- 
where, and of worms in the inteftines. In chil- 
dren it frequently accompanies the attack of erup- 
tive fevers and dentition ; in adults it precedes, 
and fometimes follows, the fiidden fuppreffion of a 
natural or morbific* fecretion ; that of all organic 
functions which are habitual'^, or which have be- 

•fix French grains with fix grains of camphor in twenty-four hours. 
He even carried the dofe to thirteen grains- Dr. Gendron gave fo 
much as ninety-fix grains with fix ounces of fyrup of diacodium 
in three days, without producing fleep. Rcc. period, de la Soc, 
dc Medecine, vol, ii. 

• Supprelfion of the menftrual flux; of difeafes of the ikin of a 
long Handing ; of old ulcers and emunftorles, &c. 

f Tndigeftion, difappearance of the gout, &c. 

. come 


come fo ; In a word, any fudden interruption \n 
the natural progrefs of the vital operations^ and in 
that of acquired habits. It is then probable, that 
what is here called difeafe Is, in many cafes, only 
an effort of vitality to recover from fome fudden 
derangement, and to attain to the complete ufe of 
its fun6lions. 

When this difeafe is elTential, it afFe£ls chiefly 
the feeble and delicate children of cities, defcended 
from parents of a highly irritable conftitution, and 
long expofed to the empire of violent paffions. It 
is common alfo to adults, and particularly womew 
endowed with an excefs of fenfibility, and ealily 
agitated by the flighteft caufesi always extrava- 
gant in their affeftions, and who proceed with afto- 
nifhing rapidity from one very flrlking emotion to 
■one diredlly oppofite. (Mutatur in horas. Horat.) 

Perfons fubjedt to this difeafe are generally 
loaded with a great deal of flabby and entirely lym- 
phatic corpulency. Sometimes, however, they are 
pale, meagre, dry, and, as we may fay, all ner- 
vous ; their fleep is generally reftlefs j they are 
troubled with frightful dreams ; have a variable 
appetite, rare flools, and much rarer fweats* 

The paroxyfms feem often to be determined by 
fome violent mental affeftion ; at other times they 
come on fpontaneoufly, without any apparent 
caufe : their duration, as well as the length of the 
intervals, is exceedingly various. 



Some authors think they have fometimes ob- 
ferved, in the return of the paroxyfms, a regular 
periodicity, and even a coincidence with the phales 
of the moon. 

On the approach of the paroxyfms arc obfcrved: 
fleep not profound, interrupted by groundlefs fears; 
fudden movements in the fingers, the arms,and legs; 
the eyes fixed or wandering ; the pupils dilated, 
and fome mufcles of the face agitated by con- 
vulfive motions : fbon after, coldnefs, a pricking 
in the exterior parts, and particularly in the 
feet, a fenlation of cold water running along 
the back, yawning, palpitation of the heart, 
anxiety in the prascordia, abdominal fpafms, uni- 
verfal tremor, pulfe hard, unequal and confined. 
All thefe Ij'mptoms exhibit great anomalies, and 
the attack is often fadden. 

The paroxyfm announces itfelf by fudden agi- 
tation in different parts of the body ; contorlion in 
various directions ; extenfion, but oftener flexion 
of the limbs, which proceed a great way beyond 
the ufual limits ; fometimes by luxations or frac- 
tures. The eyes are fometimes clofed, fometimes 
open and projefting, fixed or violently agitated ; 
fpafmodic movements of the jaw, cheeks, and 
mouth take place ; the tongus is thrull out between 
the teeth, and in that flate is often bitten. The 
vocal organs exhibit convulfive affections alfo, and 



jn this cnfc lofs of fpeech, and even of volcej i$ 
the confcquence ; refpiration is fometimes fl^^rt, 
with lymptoms of fuffocation : at length palpita- 
tion of the heart and violent cardialgia are obfervedj 
fevere griping pains in the belly, and coftivenefs; 
the urine ceafes to flow, or becomes highly limpid. 

There is no part of the body which may not be 
.afFe6led, either fingly, or in conjun6lion with a 
greater or lefs number of others. In fome cafes 
the fpafms are confined to one part only ; in others 
they proceed fuddenly from one part to another, 
without any regular or certain progrefs. Some in- 
dividuals remain in the fame pofition in which they 
were when attacked by the difcafe, or at leaft af- 
fume that nearly which gives them mofi: fatisfac- 
tion ; others fall down, and exhibit every appear- 
ance ofepilepfy, — only that the intelleciuai faculty 
remainSj and fenfation is not annihilated. In ge- 
neral, there is no foam at the mouth ; the patient 
is confcious of what takes place around him, and 
remembers it, at leaft in a confufed manner. 

In general, the mufcles poilefs a contra^ile 
force, which refifts the greateft efforts ; but at the 
end of the paroxyfm they fall into a ftate of per- 
feS: relaxation ; the patient experiences extreme 
languor, a fort of fainting, and fometimes pro- 
found drowfinefs. In fom.e the tei-mination of the 
paroxyfm is announced by flatulent eru6lations, 



abundant vomiting of mucous matter ; bloody or 
mucous evacuations from the nofe, uterus, haemor- 
rhoidal veins, &c. 

In many individuals of a conflitution exceed- 
ingly weak and fenfible, this difeafe feems often to 
arife from the fudden impreffion produced by the 
fight of a fimilar ftate; by the dread of the fame 
evil ; or by the remembrance of this afFeflion in a 
perfon fubje6t to it, but chiefly from the irrefifti- 
ble tendency to imitation. 

A paroxyfm of convulfion, in general, exhibits 
nothing in itfelf dangerous, efpecially when the 
conftitution is found, and when it arifes from an 
accidental caufe. But if the individual is weak, or 
if the firfl: caufe continues, and is frequently re- 
peated, the multiplicity of the paroxyfms renders 
the malady in fome meafure habitual. Thefe 
paroxyfms, frequently repeated in this manner, 
progreffively exalt the fenfibility, and difpofe the 
individual for receiving the influence of a multi- 
tude of new caufes ; fo that the paroxyfms approach 
each other more and more, merely for this reafon, 
that the individual has already experienced a great 
many. It is thus that repeated eftbrts to fham con- 
vulfions at length give rife to real and fometimes 
incurable movements of this kind. 

This convulflve habit often brings on, and is ac- 
companied with, hypochondriafis, melancholy, ma- 

voL. Ill, D nia. 

34 HISTORY oy disease's, 

nia, &c,; and death at length takes place by a fit 
of apoplectic epilepfy, 

Convulfions which fucceed a violent haemor- 
rhagy, any immoderate evacuation, or fevers, are 
much to be apprehended. On the other hand, when 
they precede eruptive fevers, and fome other dif- 
eafes, they appear to be advantageous* Convulfions, 

171. There is one difeafe which confilts eflen- 
tially in a fpafmodic contradion of the mufcles. 

It attacks individuals of both fexes, of all ages, 
and in all climates, but particularly in warm coun- 
tries, near the fea, expofed to damp winds ; in 
marfhy difi;ri6l3, where the temperature is fubje6l 
to great and fudden variations ; at feafons when 
thefe variations are more fenfible, and in the time 
of ftorms accompanied with cold rains. 

It is veiy common, violent^ and mortal in Ame- 
rica, where it frequently attacks the negroes, and 
particularly the children, foon after birth. 

An aCe(Slion very analogous is found in the 
cramp, which is common and as it were endemial 
in Java and Ceylon. 

This difeafe, which is very prevalent at Surinam, 
feems often to arife from a violent mental afFe6lion, 
or concentrated anger. This fpecies, common at 
Beziers, and in part of the fouth of France, is 
diftinguiflied thereby the name oi Mai deVdme, 



Obfervation feems to indicate as the caufes of 
this difeafe : ftrong mental afFe(5lions ; the fudden 
impreffion of intenfe. and particularly damp cold 
after a hot temperature ; the prefence of worms in 
the inteftines: it comes on alfo in confequence 
of wounds or chirurgical operations, and in this 
cafe does not manifeft itfelf till the end of feme 

The development of this difeale is, for the moft 
part, flow and gradual. There firll comes on a 
fenfation of ftiffnefs towards the nape of the neck, 
which by degrees increales, accompanied with con- 
Uraint and pain in moving the neck. Deglutition 
afterwards becomes difficult, and then impoffible : 
in this cafe there is often a violent pain at the bot- 
tom of the fternum, which extends thence to the 
back, with a fudden contradlion of the cervical 
mufcles, which (Irongly pull the head backwards. 
At the fame time the jaws have an infuperable 
tendency to approach each other. The difeafe 
fometimes remains at this degree, and is known by 
the name of a locked-jaiv. Trifmus, 

In other cafes are obferved frequent returns of 
fternal pain, cervical and maxillary fpafms ; and 
during the further courfe of the difeafe a fpafmodiq 
-rigidity of the doifal mufcles takes place, and thq 
whole body is thrown backwards {Opfilfotoms)* 
The limbs then become ftiff and inflexible; th§ 
(ides of the abdomen appear very hard, and as if 
drawn back by the contraction of the mufgles of 

D 2 that 


that cavity. In the lall place, a violent contra6tion 
takes place in the flexor mufcles of the head, the 
neck, and the trunk {emprcjflhotonos), an exten- 
lion and uniform rigidity of the trunk and limbs, (o 
that, in railing the feet or head, the whole body 
flands ere61 like a plank : the arms and lingers are 
the laft parts which become llifF. Towards the end 
of the difeafc, the tong-ue is fometimes thrufi: with 
violence between the teeth ; all the mufcles feem 
then to be afFcfted ; the forehead becomes corru- 
gated ; the eyes turn round, and in general remain 
fixed ; the note fhrinks, and the cheeks are drawn 

^ When the general tpalin has continued fomc 
minutes at the higheft degree of force, with ex- 
cruciating pains and piercing cries, there comes 
on a certain ftatc of remifl^on and calmnefs, but 
which does not lafi: a quarter of an hour ; and 
the fpafms and pains foon recur with their for- 
mer violence. In the courfe of the difeafe, ob- 
flinate watchfulnefs takes place ; the individual 
for the mofi part retains the free ufe of his in- 
telle6l and fenfes : fometimes, however, his ideas 
feem confufed, and his mind is even completely de- 
ranged. Refpiration is difficult, the voice hoarfe, 
third infatiable, with an impoflibility of fwallow- 
ing. The urine, fometimes ilipprefl^d, iiiues with 
difficulty, or in jets, when the bladder is com- 
prefied: conflipation is habitual. 

In the laft place, towards the end; a fort of prii- 
. -. ritus. 


rltus, or pricking, is experienced in the fpine ; a 
fenfation analogous to that of a liquid flowing tO' 
wards the facrum ; a gradual diminution of the 
iymptoms, or a cold, abundant, and univerfal fweat, 
convulfions, and death. 

The difeafe^ fometimes partial, confines itfelf to 
the mufcles of the jaw and neck, either anterior, 
pofterior, or lateral. At other times it is univerfal, 
and keeps the body in a ftate of perfect rigidity, 
extended, or bent backwards, forwards, or towards 
the fides. The pains are often confined to certain 
parts, fuch as the head, the bottom of the mouth, 
one fide of the breall:, the epigallrium, the loins, 
and the limbs. In the lafl place, Salivation, fyn- 
cope, tremor of the limbs, &c. may take place. 

In fome cafes, the progrefs of the difeafe is ra- 
pid, and produces death in thirty or thirty-lix 
hours ; and, for the mofl part, before the fourth 
day. It is when the difeafe comes on in confe-^ 
quence of wounds (traumatic) that its progrefs is 
moll rapid. After the fourth day the danger de- 
creafes; but there is always reafon to apprehend 
new paroxyfms as fatal as the firft. The fymptoms 
never difappear fuddenly : they decreafe gradu- 
ally, and fometimes require a conliderable time be- 
fore they ceafe entirely. 

Sometimes the progrefs is flower: the convul- 
iive movements, which are traniitory, come on by 
repeated paroxyfms, and at intervals which vary 

D 3 from 


from one hour to feveral minutes; the jaws are 
never forced exadtly together ; deglutition, though 
difficult, is always poffible j the body is flightly 
bent forwards; the patient cannot bear to re- 
main in a recumbent pofture, and can enjoy no 
reft but by placing himfelf in a tranfverfc poiition, 
with his belly on the edge of the bed^ and his feet 
on the floor. According to Bajon, this variety, 
which fcarcely ever proves mortal, continues feve- 
ral months, and fonnetimes four or five. Towards 
the end there comes on a pretty acute fever, with 
an abundant fweat, and a cure is then effe(51ed. 
Hippocrates confiders fever as falutary when it 
takes place in this difeafe. {A^h. Ivii.yf^. 4.) 

172. In America, the negro children who corTi-» 
monly refide in huts badly Iheltered from the in- 
clemency of the weather, and from fudden vari- 
ations of the temperature, are very fubje^ to 
this malady. It is much more common on the 
borders of the fea, and in elevated places, than iq 
diftri6ts fheltered by the lofty woods. To fecure 
the children from it, they are kept in c|ofe warm 
apartments, and frequently fubjet^ed to dry fric- 
tion. This difeafe has become lefs common in 
^t. Domingo fince the female negroes have been 
made to lie-in in the hofpitals. It generally makes 
its attack in the firlt nine or ten days after birth, 
§n4 rarely beyon4 that period, Som^ are afFe6ted 


-almoft the moment they come into the world, an^ 
die in a very fhort time. 

The child jfirft experiences a difficulty of taking 
the breaft, which it incefTantly quits and refumes ; 
it continually emits difficult and plaintive cries, 
and exhibits a ftiffnefs in the jaw, the neck, and 
along the fpine. The n^ck remains ftraight ; but 
the trunk becomes bent either forwards or back- 
wards ; the mufcles of the limbs are lefs ftrongly 
extended than thofe of the trunk; the compreffion 
of the jaws becomes complete ; the tears and cries 
decreafe. Irregular movements in the limbs, the 
trunk, and jaws, llarting of the mufcles of the 
cheeksare then obferved, and a (limy falivation takes 
place. The fkin after certain intervals afTumes fome- 
times a red and fometimes a violet tint. This difeafe 
always terminates in death, and very often in the 
courfe often or twelve hours; but, for the moft 
part, towards the fecond, and fometimes not till the 
tenth or twelfth day. In general, its progrefs is 
flower, according as its attack commences longer 
after birth. 

173. A variety of this difeafe, characlerized by 
a rigidity of the jaws, difficulty of fwal lowing, in-» 
duration of the cutaneous tilTue, convexity of the 
foles of the feet, and an apparent curvature of the 
limbs, has been obferved in the Foundling Hofpi- 
tal at Paris, It appears to have been produced 
04 by 


by the impreffion of cold. {See Soc. Roy, de Med. 
Sept emir e^ ly^J-) 

The ufe of opium in ftrong dofes feems to have 
been attended with ftriking fucceis in this difeafe*, 
which is diftinguifhed by the name of Tetanus. 

1 74. There is one general afFedtion of the ner-^ 
vous fyftem, which manifefls itfelf by alarming 
iymptoms; it is always dangerous, and, for the 
moft part, mortal. It is communicated by the faliva 
of an animal in a ftate of madnefs brought into 
conta(5]: with a part deftitute of epidermis. It is in 
the faliva only that the infe(5lious quality relides ; 
and animals who have died of this difeafe may be 
touched with fafety. 

In general, it is more to be apprehended that 
infedlion will take place when the animal has bitten 
a naked part, than when the wound has been in- 
fli6ted through tbe clothes. It is probable, alfo, 
that the ad ion of the faliva is ftronger or weaker, 
according to the flate of the animal, which may be 
either melancholy mad, or entirely furious. The 
greater or lefs fenfibility of the perfons bitten, and 
the particular (late in which they are, render them 
more or lefs difpofed to be afFedled ; the power of 
imagination, which heightens fear, and the dread * 
of being attacked by fo horrid a difeafe, contribute 

* Opium has been given in very large dofes in tetanic affeftions 
without producing fleep.. 

. 6 alfo. 


alfo, in a great degree, to aggravate the fj'mptoms. 
The period between the time of being bitten and 
the comnaenceinent of the difeafe is exceedingly 
various : it generally takes place on the third or the 
foarth day ; fometimes fooner, and at others not 
till the end of feveral months j fome authors even 
fay feveral years. 

The commencement of the madnefs is always 
announced by ibme phasnomena in the wounded 
part ; the fear becomes red, or blueifh, and fome- 
times opens and difcharges a reddifh lerous matter. 
If the wound is not cicatrized, its edges are invert- 
ed, the flefh fwells, afllimes a redder colour, and 
furnifhes only reddifh and ferous mucus. The 
fleep is then troubled, and agitated vi'ith ftarting 
and frightful dreams ; the patient falls into a deep 
melancholy, from which he cannot be roufed ; ex- 
periences heavinefs and great depreffion ; heat 
comes on from time to time, with fliivering, which, 
commencing at the wound, is extended to the 
whole body, and feems to terminate at the breafl 
and the throat : the pulfe, in general, is fmall, 
hard, and clofe. 

At the end of three or four days all the fymptoms 
incrcafe: the patient experiences pain in the head, 
loathing, watchfulnefs, a general fenfation of lati- 
tude, a painful conftri€tion at the breaft and throat, 
which prevents him from f\valIowing ; refpiration is 
difficult, interrupted by involuntary fobs and deep 

' fighs ; 


lighs ; convulfions, renewed by the leall: caufe, 
from time to time take place. The patient, at 
intervals, lofes his reafon, becomes furious, does 
not know his nioft intimate friends, attempts to 
bite them, and fometimes even tears himfelf. Every- 
thing irritates and provokes him ; bright colours, 
the fplendour of the light, the leaft motion, the 
flighteil found, the agitation of the air, excite his 
fury. Burnt up by internal heat and ardent thirft, 
he is afraid to drink j the very idea even of water 
makes him fnudder *. The face becomes red, and 
the eyes haggard, fixed, and fparklingj he has an 
air of ferocity, and at the fame time of fear ; the 
voice is hoarfe ; and fpumous faliva flows from his 
mouth. Retaining fometirnes his intelled^ual fa- 
culties, he. remains peaceable, immerfed in deep 
melancholy; is fenfible of his unhappy ftate ; fore-^ 
fees the return of the paroxyfms, and advifes his 
friends to be on their guard. Sometimes he re- 
mains in filent ftupor j at others emits loud cries 
and dreadful bowlings. Sometimes he acquires 

* The dread of water, and a propenfity to bite, ai^e fymptoma 

not peculiar to this difeafe alone. An averfion to liquids has beeq 

obferved in fome fevers attended with phkgmafia of the throat 

or ftoraach, in fome cafes of hyfteric affeflion, &c. The furor 

and irrefiftible propenfity to bite and tear, form the charafter of 

certain kinds of mania ; it is fometimes feen during parou^yfrns of 

epilepfy ; and thefe fymptoms are not always obferved in perfons 

labouring ur\der canine rnadnefs ; v/e mj^y even fay thait tbey are 




an extraordinary increafe of phyfical ftrength ; at 
others is thrown into a ftate of the utmoft timidity, 
a fort of lethargy or palfy. Trifmus, and a fpaf-' 
modic tenfion of the mufcles of the belly, often 
take place. Some experience a very painful pria- 
pifm, accompanied fomctimes with ejaculation. At 
length, after four or five days, the patient is 
feized with extreme agony; his pulfe becomes 
unequal and intermittent; vomitings, with a uni- 
verfal cold fweat, come on, and he dies in coq- 

This difeafe is very rare : all the individuals bit-^ 
fen by mad animals do not experience the fym- 
ptoms of hydrophobia ; and it is probable, that very 
often after a bite by an animal fuppofed to be in 
that ftate, nervous ()'mptoms, more or lefs ftrong, 
produced by a fervid imagination, a fatal terror, or 
the laceration of the parts, have taken place. It 
jpnay be readily conceived alfo, that the faliva of 
an animal irritated in a greater or lefs degree 
may acquire a certain quality proper for exciting 
fome flight fymptoms, which imagination and ter- 
ror increafe, and perhaps render fatal. It is, there- 
fore, of great importance, that a fufpe^ied animal 
fhould never be killed until the nature of its ma- 
lady has been accurately afcertained. 

The carnivorous marnmalia are thofe only whicli 
appear to be fufceptible of fpontaneous madnefs : 
\\ip lierbiyorous are apt to receive it^, but have not 



the power of tranfmitting it. It manifefts itfelf 
particularlyamong dogs, during hot fummers and 
very dry winters. This difeafe is afcribed, in ge- 
neral, to the want of drink, and to extreme fatigue 
while expofed to fcorching heat. 

175. The fymptoms at firil obferved in a mad 
dog are : fadnefs, dejection, a defire of folitude, 
flartings at intervals ; tlie animal does not bark, 
but often fnarls, and without any known caufej 
refufcs food and drink ; his eyes feem dead ; he has 
a wild look, ftaggers in walking, drags his tail be- 
tween his legs, appears as if alleep, and obeys with 
difficulty. At the end of two or three days he 
does not know his mafter ; abruptly quits his habi- 
tation, and wanders about with uncertain fleps, his 
hair ereel, and his eye threatening, which is conti-- 
Dually in motion, or remains entirely fixed; his head 
hangs down, his mouth remains open, and his 
tongue, dependent, is covered with fpumous flaver. 
Other dogs flee on feeing him. Sometimes he 
{buns water, fhudders, and is irritated on feeing it ; 
at other times he fwims acrofs it. 

In this flate he attacks and bites, without di- 
ftin6lIon, every perfon or animal that falls in his 
ways it is then that his bite is exceedingly fatal ; 
but, in general, after thirty or thirty fix hours he 
dies in convulfions. The body foon pafies to a 
ftate of putrefadion. 



It-does not appear that canine madnefs ever took 
place fpontaneOLifly in man*. 

This difeafe, when once fully charadlerized^ is 
conftantly mortal -f-. 

After deathj no traces of alteration that can be 
exclufively afcribed to the difeafe are obferved in 
the organs ; which feems to prove that it conlifls in 
a great perturbation of the nervous fyftem. 

If canine madnefs confifts in a deranged move- 
ment communicated to the a6lion of the nerves by 
the poifonous faliva^ and if this movement, height- 
ened by the fymptoms it produces, increafes fo far 
as to annihilate'thc whole vital force, there is rea- 
fon to believe, that the moft proper mean for op- 
pofing the development of the malady is to imprefs 
fpeedily a foreign a61ion on the whole fyftem, and 
to maintain it for fome time ;|:. 

Hence the utility of cauterizing the wound 
flrongly with a hot iron, or cauftics, and of main- 
taining in the part a violent and long-continued ir- 
ritation. It is necellary alfo, at the fame time, to 

* The reader, however, may fee two cafes of this kind by Galet 
Dupleffis in the Mcmolrcs d- la Sac. Roy ah de Mklcdne. 

t See the fingle cafe of Nagent, given alfo in the Memoires de 
la Soc. Royals de Medeclne. 

X C. Pmel learned from fome perfon who refiJed at Laiifanne 
at the time, that Tiffot and Haller having caufcd a man labour- 
ing under hydrophobia to be bitten by two vipers, a calmnefs im- 
mediately toofe place, with a certain degree of infenfibility ; and 
the wounds being afterwards drcffcd^ the patient recovered. 


A6 tllStbRV op btSEASEg. 

port the general energy by powerful ftimulants, and 
in particulartooccupy the imagination, in orderthat 
the perfon may entertain no fear of a certain cure. 

176. There is another con vulflve affeflion which 
manifefts itfelf by paroxyfms of iTiort diiration,fome- 
times periodical, but, for the moft part, irregular. 
It feems to confid in a fudden interruption of the 
functions of the intellectual organ, and of the or- 
gans of the fenfes, with a convullive movement of 
the mufcles. 

In many cafes the acceffion of this difeafe takes 
place fudderJy, without any anterior fymptoms : it 
is frequently announced by a peculiar fenfation, like 
that of fome body moving, often from the extremity 
of a limb, and gradually afcending, without exadlly 
following the courfe of any principal nerve, as far 
as the head ; after which the paroxyfm fuddenly 
comes on. Sometimes the fenfation is like that of 
a cold vapour, or fluid, running along, or of the 
creeping of an infect ; fometimes the fenfation can 
hardly be defcribed. In certain cafes, this fenfation 
arifes from prcfTure, from the irritation of a nerve, 
from a wound, a contufion ; but, for the moll: part, 
no Isefion whatever in the part can be difcovered. 

This movement may fometimes be interrupted 
by ligatures, or by fire, occafionally applied. To 
prevent an attack, and cure the difeafe radically, 
extirpation of the part is recommended. 

7 Indepen- 

Convulsive affections. aJ 

Independently of this vapour, which in certain 
individuals always precedes, but for a very fhort 
time, the paroxyfms. they are announced alfo, in 
(bme, at longer or fhorter intervals, and fometimes 
every other day, by nervous fymptoms exceed- 
ingly various and inconftant : torpor, drowtinefs, 
vertigo, fvvelling of the eye-lids, watering of the 
eyes, tinging in the ears, rednefsofthe upper part 
of the nofe, betvi^een the eye-brows, turgency of 
the veins of the forehead, frightful dreams, agi- 
tated fleep, violent pains in the head^ accelerated 
pulfation of the temporal arteries, &c. 

This difeafe exhibits numerous varieties, in re- 
gard to the violence of the paroxyfms, and the 
number and intenfity of the fymptoms. Some- 
times the paroxyfm is a mere ftupor, a few mi- 
nutes of vertigo, a fufpenlion, or at lead momen- 
tary alteration, of the intelledlual fundions, with a 
flight convulfion of fome particular part. At other 
times the face becomes red ; the whole body is 
ftifF, and fome convulfive movements are obferved 
in the eyes. 

For the moft part, a fudden and repeated aboli- 
tion of the mental faculties of fenfation and volun- 
tary motion takes place: the patient falls down, 
and often with a piercing cry. In this cafe, ilrong 
contortions of the limbs, of the head, and of the 
trunk, are obferved, and generally ftronger on one 
iidethan on the others diftorfion of the mouth, face, 
and eyes; the tongue, which itTues from the mouth, 



isfubjeffl to be feverely wounded, and even cut, by 
the convulfive collifion of the jaws; the pulfe is 
fmall ; refpiration precipitate and irregular ; the 
penis in a ftate of erection ; and the paroxyfm thus 
pafles with conftant alternations of calmnefs and 
new convullions. 

After a certain period, a matter, commonly vif- 
cid and fpumous, is reje6ied from the mouth. In 
the flightefi: paroxyfms, a few bubbles only appear 
towards the angle of the lips. Sometimes there is 
alfo an involuntary evacuation of urine, of faecal 
matters, and even of fperm. 

The duration of the paroxyfrn varies from fome 
minutes to about half an hour*. 

Towards the end, the patient remains fome mo- 
ments motionlefs, with the appearance of profound 
lleep ; at length he fpeedily recovers, and often 
gradually, both fenfation and mufcular fbrength, 
without any recolleftion of the paft. The pulfe 
and retpiration return to their ufual flate. 

* I have feen a young woman between the feventh and eighth 
rnonth of her pregnancy, who after a violent mental affcftion ex- 
perienced headache, a fenfe of fufFocation, pain in the epigaf- 
trium, and at length a fit of epllepfy, which continued fome mi- 
nutes, and which left her infenfible, in a ftate of torpor and pro- 
found (jeep. The paroxyfrn returned in an hour, with the fame 
intenfity. This dreadful ftate of continual torpor and epileptic 
fits, which recurred at the end of one or more hours, continued 
thirty-fix hours, and was not removed but by the application of 
twenty-four leeches to the temples. 



After a firft paroxyfin takes place, it leaves be- 
hind it fo great a fufceptibility, that the llighteft 
caufe very often produces a fecond ; and it at length 
appears, that there is eftablifhed a fort of habit 
which renews the paroxyfms without the interven- 
tion of any known caufe. Many variations occur 
during the intervals between the paroxyfms. Some- 
times the periodicity is very regular; but, for the 
raoft part, there is no conftancy in the returns. It 
appears, in general, that they follow each other 
tjuicker, according as the difeafe is of longer Hand- 
ing. Some have imagined that they could fometimes 
difcover a certain relation between thefe returns 
and the phafes of the moon. It is obferved alfo 
that they take place, in particular, during fleep, or 
immediately after awaking. 

When the paroxyfms have recurred for a long 
time, the difeafe often terminates by producing a 
debility of the mental faculties. It gives rife to a 
greater mobility, a more decided aptitude for all 
mental afFedlions, joy, anger, &c. It occafions a 
lofs of memory, and a ftate of ftupor, or even mad- 
hefs*. It alters alfo the features of the face, en- 
larges the inferior eye-lids, and the alae of the nofe. 
After a flight or violent paroxyfm there fometimes 
remain : deafnefs, blindnefs, paify. See. Sometimes 
a flight paroxyfm is converted into apoplexy. 

* Among two hundred maniacs C. PInel counted twelve or 
fifteen epileptics. 

VOL. III. ' E This 


This difeafe is more peculi'ar to infanc}'', apd 
even in the firfl: years of lifej to youth, to fe- 
males, and in general to individuals of great ner- 
vous irritability, who are as eatily animated by hope 
as deprefled by fear ; who are moved by the flight- 
eft affe6tions; and in whom the impreffions of for- 
row, anger, or joy, excited by the moft trifling 
caufes, fubfide with the fame facility. It attacks 
plethoric perfons in preference to others. 

It is often impoflible to determine the caufes by 
which this difeafe is produced. The moft fre- 
quent, however, are deep-roottd mental affei5lions, 
violent'iri^VbnexpB^te4 impreiiions, great forrow, 
feve^.'difappSirifment%:i.aSonifliing news, the de- 
feat of @:gpr^ a.ftnang' lenfe of horror and aver- 
fioia j- but, in particuMy a fright in infancy*. 
ManyN4ti4iviiduals Is^^^^Joeen attacked by this dif- 
eafe merely in comequence of having feen par- 
oxyfms of it in others ; and this appears to arife^ 
from that irrefiftible propenfity to imitation which 
is exceedingly ftrong in debilitated perfons. It takes 
place alfo fomctimes after a wound or frafture in 
the head ; a depreffion of the bones of the cranium ; 
exceflive hasmorrhames, &c. 

This difeafe, efpecially during the firlt years of 

* In recapitulating the manlfeft caufes which Teem to have 
produced the firft acceffion among the numerous epileptics of the 
Hofpital de Bicctre, C Pinel obferved that tlic lall-mentioned 
caufe was the moft common. 



life, may be produced by fo many caufes, that it is 
difficult to afcertain whether children may not be 
born with it. All tbofe almoll who experience fre- 
quent paroxyfms during their earlieft years fall a fa-' 
crifice to it before they attain to the age of puberty. 
When it commences between the age of five and 
ten, it may fometimes be cured. That which ap- 
pears about the commencement of puberty (from 
twelve to thirteen) without any manifeft caufe, 
generally ceafes when puberty is fully ellablifhed. 
Sometimes it is cured by marriage ; at others^ 
its fymptoms are increafed by it. 

When it declares itfelf before the eftablifhmentj 
or during a fuppreffion, of the menftrual flux, it is 
always cured as foon as the flux becomes regular. 
Though it comes on after puberty, it does not ap- 
pear to be incurable. It feldom attacks old per- 
fons i and thofe attacked by it at a younger age 
are either cured or die before they become old. 

On opening the body no organic alterations are 

in general found, and even when laefion of the vil- 

cera* occurs, it is often diflicult to conceive how 

it could have been the caufe of the difeafe. 


* There have been found in the head: carles of the interior la- 
mina of the bones ;/^ exoftofis ; fharp offeous excrefcences, of 
greater or lefs length, proceeding from different parts of the bafe 
of the cranium, and penetrating the encephalic organ j an ulcer 
in the membranes, the effufion of afiuid. In other parts : an ulcer 
at the cefophagian orifice of the ftoraach, phlogofis, vibices, or 

's. ^ " ' gangrenous 


The age, fex, and particular conftitution which 
are mofi: fufceptible of this difeafe, and the caufes 
by which it is moft frequently produced, feem to 
indicate that it may be referred to a weaknefs or 
too great irritability of the nervous a6lion. 

Some examples are quoted, which feem to fhow, 
that when a violent impreflion, ftronger than that 
which produces the difeafe, and capable of break- 
ing the force of habit which maintains it, is made 
on the nervous {yUern, a cure is efFeded*j but thefe 
particular inilances are not fufficient to eilablifh 
any general precept for the treatment of this dif- 
eafe, which has been diftinguifhed by the name of 

• gangrenous fpots in the pharynx, the oefophagus, the flomach, 
the Inteftinal canal, and in other places j biliary calculi j fcirrho- 
fities in the fpleen, greater fluidity of the blood, flaccidity of the 
folids, and a greater tendency of the body to putrefaftion when 
the patient has died of a long continued paroxyfm. 

* What Kaaw Boerhaave did at the Hofpital for Orphans at 
Haerlem to check the progrefsof this difeafe, which was propa- 
gated by imitation, is well known. 


[ 53 ] 

177- The peculiar affections in which the intel- 
ledlual fundions are eflentiaily deranged are ex- 
ceedingly numerous and varied. They are never 
obferved, in general, but in perfons who make a 
bad ufe of the vital powers, and whofe intelledual 
organ is habitually in a greater or lefs degree of 

In individuals of a weak conllitution, when the 
function of the intellectual organ is highly exalted 
in regard to objects of the imagination, when the 
action of the genitals is flrongly excited, when the 
gaftric organs are continually overcharged with 
too fucculent nourifhment, highly feafbned, and 
almoft wholly digefbed, and when the mufcular 
adion is annihilated ; this concurrence of cir- 
cumftances, which forms fo (Iron g a contraft to the 
mode of life for which man feems by his organiza- 
tion to have been deftined, produces, efpecially in 
large cities, a highly varied feries of phaenomena 
of difeafe; but to give a detailed hiflory of them 
would be tedious and difficult. 

A great number of them, however, are compre- 
hended under the two general forms which we are 
here going to defcribe. 

E 3 178. The 


178. The firft often occurs in mature age, that is 
to fay, between thirty and fifty. It is more common 
among men than among women, is often hereditary, 
and attacks in preference perlbns debilitated by ir- 
regularities, or by long difeafes, thofe who lead a 
fedentary life, and fuch as are addicted to too clofe 
fiudy : it is in fome meafare the difeafe of men of 
letters. It arifes, for the moft part, from a con- 
currence of caufes, more or lefs multiplied, which 
exercife a long continued action : excefs in the la- 
bours of the cloiet, fudden tranfition from an ac- 
tive to a fedentary life ; the abufe of narcotics; ex- 
cefs in the pleafares of love ; fometimes from an 
acute affe6lion experienced in the epigaflrium ; a 
great fright ; deep grief; and in vi'omen, accidents 
during pregnancy, or during parturition, &c. 

A fingular atlemblnge of varied and extraordi- 
nary fymptoms are then obferved to take place. 
Thofc obferved in re2:ard to the mental faculties 
are: unfteadinefs of character, ficklenefs of tem- 
per, irafcibility, reftleffnefs, fadnefs, timidity, and 
languor. The individual pays minute attention to 
the ftate of his health ; every change of fenfation 
makes him apprehend danger, and even death ; he 
becomes unfit for labour; a derangement of memory 
and tranfient delirium take place ; his fleep is dif- 
turbed; he experiences pains in the head, vertigo, 
confulion of fight, tinging in the ears, dullnefs of 



hearing, an irregular fenfation of ardor in the 
face, fudclen alternations of heat and of cold fweats. 
Thefe fymptoms become exafperated at irregular 
periods, and fometimes in a conftant manner after 
meals : in general, the patient is much afFe6led by 
every change in the ftate of the atmofphere. 

The gaftric fyftem, in particular, exhibits varied 
fymptoms of derangement : fuch as loathing, depra- 
vation oftafle, naufea; irregular appetite, fometimes 
none, and at others a voracious one ; tenlion and 
heavy pain in the flomach, efpecially after meals j 
bad digeflion, frequent vomiting, belching up of 
burning and highly acid matters, hiccup, (hooting 
pains in the abdomen, flatulencies, borborygmu?, 
confiipation or diarrhoea. 

Sometimes fwelling or even a very hard tumour 
is felt tov^'ards the hypochondria ; the patient ex- 
periences a fort of con{l;ri6lion at the breaft, op- 
preflion, palpitation, irregular throbbing in fome 
parts of the abdomen. 

Thefe affecSlions, which often continue for feve- 
ral years, occafion a flow and gradual confump- 
tion, that in the end always becomes mortal. 

Very often, on opening the body, no organic 
alteration is obferved. A fcirrhus, however, is 
fometimes found in the colon, an enormous fwell- 
ing of the fpleen, ulcers in the pancreas, varices in 
the meferaic veins ; and it is probable that thefe 
derangements have at firft often been the confe- 

E 4 qiience 


quence of a nervous affeclion of the organs of di- 
geflion^ and that they have afterwards become the 
caufe of a part of the confecutive accidents. The 
aggregate of thefe fymptoms is generally diftin- 
guiflied by the name of hypochondria/is. 

179. The fecond form is met with, for the moil 
part, among females, rarely among the other fex^ 
and chiefly among young women of an ardent 
cohflitution, who have a ftrong propenfity to ve- 
nereal pleafure ; among women of all ages who. 
live in a ftate of voluntary or forced continence; 
among young widows, who, fuddenly deprived of 
the enjoyments to which they were in fome mea- 
fure accuftomed, abandon themfelves to high liv- 
ing, to indolence, to lafcivious ideas, and to the 
reading of books calculated to excite them; among 
thofe whofe menfi:raation is difficult ; in a word, 
among all perfons who make a bad ufe of their 
HJicllediual, digeftive, mufcular and generative 

With thefe difpofitions, the fight of a handfome 
young man on the ftage, or in a cheerful com- 
pany, a diiappointment, a tit of paffion, peculiar 
odours and favours, accidents during pregnancy, 
and very often caufes which cannot be difcovered^ 
may produce the following feries of fymptoms^ 
which fometimes come on gradually, but for the 
molt part by paroxyfms„ 



The individual firfl experiences drowfinefs, agi- 
tated fleep, intervals of fadnefs, aftonifhment, and 
ftupidity, often accompanied with the effulion of 
tears, or incoercible laughter, for whole hours. The 
organs of the fenfes are in fuch a ftate of debiHty and 
irritation, that they are painfully affected by a 
ftrong light, a fhrill found, ftrong odours and fa- 
vours, fudden touching, and every unexpedled 
movement. The limbs remain in a ftate of torpor. 
Sometimes a heavy pain takes place in the fore- 
head, in the temples, and the eyes, with a confu- 
lion of light, and, at intervals, aphonia. The pa- 
tient experiences, in the left fide of the abdomen, 
or towards the hypogaftrium, a pain and tumefac- 
tion : a fenfation like that of a globular body mov- 
ing in various dire61:ions, proceeds towards the llo- 
mach, and gradually afcends thence to the larynx. 
In all thefe cafes afpafmodic conjiridion is felt in the 
throaty with a fort of fuffocation. A fpafmodic af- 
fection of the inteftines is obferved, with borbo- 
rygmi exceedingly noity, and very irregular agita- 
tions. Sometimes tenfion and tightnefs of the 
l^elly take place, accompanied with a conftric- 
tio'n of the anus ; the urine is often abundant and 
limpid ; refpiration, Ihort and precipitate, is per- 
formed by ftarts ; at other times it is fufpended j 
and in this cafe the pulfe becomes infenfible. Al- 
ternations of rednefs and palenefs are obferved in 
the face,- in fome cafes the vifageand neck are red 



and fvvelled, with a (Irong pulfation of the arteries. 
At length the trunk becomes ftifF, is twifted round 
in different directions ; the limbs experience a 
fpafmodic contraction ; a cold fweat is diffufed 
over the whole body, and the patient remains in a 
ilate of apparent death, which may continue forty- 
eight hours, rarely more. Sometimes all thefe ac-^ 
cidents terminate in real death. 

On the decline of the paroxyfm a gradual re- 
turn of the natural heat, and of the ufe of the 
fenfes, is effedled; the ilrength is progreffively 
reftored, and the fpafmodic lymptoms at length 
ceafe. Repeated fobs and fighs take place, with 
flatulent emulations ; a relaxation of the genital 
parts, and a difcharge of mucous matter. The 
perfon awakes as from a profound ileep, for the 
mod part with a pain in the head, and general lari- 
guor, and a remembrance or no recolle6lion of 
what occurred during the paroxyfm. 

The intenfity and nature of the fymptoms, th? 
alternation of fome of them with each other, their 
greater or lefs exacerbation, their lono;er or fhorter 
duration, produce all the varieties of this difeafe; 
which may be more ealily conceived than de- 

Very often, on opening the bodies, no organic 
derangements of the abdomen are obferved : fome- 
times, however, an alteration is found in fome of 
the vifcera \ but in this cafe they appear to be ra- 


ther the efFedl of the long feries of nervous affec- 
tions which conftitiited the paroxyfms,. than the 
primitive caiife of them*. It is, however, certain 
that thefe derangements, when they exiti, mnft 
afterwards render more conrrplex and increafe the 
gravity of the fymptoms of this difeafe, which has 
been di'ilinguifhed by the name o{ hyjierics, 

180. Medicine has very little power over this 
difeafe or the preceding ; or can only produce 
fome flight remiffion in the paroxyfms. As thefe 
affe6lions evidently arife from a bad ufe of the 
fun<5lion of the intellectual, mufcular, digeftive, 
and generating organs, they cannot ceafe till thefe 
functions are employed in the proper manner: 
hence occupations agreeable either in point of 
tafte or of intereft, travelling, exercife faited to 
the ftrength, wholefome nourifhment not too fuc- 
culent, and which may afford occupation to the 
flomach, moderate ufe of venereal pleafures, are 
the only means of reftoring health. 

* Vefalius often fouiid the ovaria larger than a tennis ball, and 
filled wltll^ yellow liquid highly fetid ; Riolan found an ova- 
rium indurated, and larger than the fill ; BInninger obferved a 
lleatomatous ftate of the ovaria and the uterine tubes containiiig 
a white, thick, and almoftfolid humour ; Diemerbroeck, a certain 
increafe of fize in the uterus, and ayellowifh humour in its cavity; 
Mager found the uterus voluminous, entirely ollified, and filled 
with a whitlih, purulent, and fomewhat thick liquid, &c. 

181. The 


1 8 1. The intelledlual organ is fometimes de- 
ranged in confequence of the too great aftion ex- 
crcifed on it by the uterus, or of the reelprocal 
a6lion of thefe two organs^ which mutually exalt 
each other. 

In young women of premature paflions, who are 
deeply in love, and whofe inclinations have been 
thwarted by infarmoun table obftacles ; in debauch- 
ed females, efpecially when fuddenly torn from 
their antient habits by forced feclnfion j in ardent 
females united to cool hufbands infenfible to the 
enjoyments of love, or whofe weak conftitution 
commands temperance; in young widows fud- 
denly deprived of flrong and vigorous hufbands, 
in their intercourfe with whom they had acquired 
the habit and need of pleafure, and the remem- 
brance of which occafions bitter regret^ when thefe 
firft difpofitions are much increafed by forrow and 
difappointment, by reading lafcivious romances or 
poetry, or looking at lafcivious pidlures, with which 
their imaginations are continually heated ; by the 
life of fucculent, delicate food, generous wines, 
ftrong liquors, idlenefs, and particularly a habit of 
folitary pleafures, a feries of very extraordinary fym- 
ptoms fometimes takes place. 

There is firll obferved a Angular inclination to 
diredl: the converfation to one favourite fubje6l; 
rreat languor and ennui when it turns on any thing 
©Ife ; a great readinefs to liften to flattery ; an 



averfion to all occupations, even of the eafieftkind. 
Thefe phEenomena are foon fucceeded by dejedlion, 
uneafinefsj a love of repofe, folitude^ and filence. 
All the thoughts are entirely confined to obfcene 
obje6ls ; appetite and fleep are both loft. The in- 
dividual becomes fubje<5t to inordinate defires^ of 
the turpitude of which fhe is fully fenfible ; fhe 
makes efforts to retiirn to a ftate of reafon, or at 
leaft to conceal from others her condition ; fhe 
even hopes to be able to conceal it from the per- 
fon who is the caufe of it. 

Soon after the becomes entirely abandoned to 
lafcivious thoughts, which fhe defpairs of being 
able to refifl ; a laft attack is made on modefl:y, 
which is now compelled to yield ; the flrength is 
exhaufted; deep melancholy comes on, and effron- 
tery alTumes the place of decency. The leaft flat- 
tery is received with an impaffioned tone of voice 
and geflures ; (he is lavifh of her careffes, prayers, 
folicitations, and even threats, to induce the firfl 
perfon fhe meets to gratify her defires ; and if he 
refifts, fhe infults him with the mofl calumnious 
reproaches, and befiows on him every opprobrious 
name that anger and revenge can fuggelt. 

At length a complete alienation of the mental fa- 
cullies is announced by difgufting obfcenity, cries,- 
tranfportsof paflion, lafcivious gcdures, an afFefta- 
tion of nudity ; all males are folicited, urged, and ^ 
followed with a blind fury, and beaten or torn if they 



refifl. The patient experiences continual watch* 
fiilnefs, an univerfal burning heat, without fever or 
thirft ; inlenfibility to the moft fevere cold. 

In all thele periods, but particularly the third, 
there is often experienced a very diilreffing itch- 
ing towards the vulvo-uterine conduit and the 
uterus. Thefe parts, which are fometinaes in- 
flamed, excrete a thick, vifcid, fanious liquor, and 
the clitoris becomes lengthened or tumid. In 
this cafe, on opening the body, there are found an 
ulcer in the uterus, Iwellingofthe ovaria, &c. 

This peculiar alienation, known under the name 
of the fiymphomania, belongs, in a great meafure, to 
moral medicine. ' 

182. Men are fbmetimes fubjeS: to a dlfeafc 
which has fome refemblance to the nymphomania. 
It announces itfelf by an infatiable defire for vene- 
real pleafures, while ere(51ion is neither weakened 
nor diminifhed by enjoyment. A general fpafm or 
tenfion prevails in the groin, with pain in the ge- 
nitals, an itching or titillation in the fides and arm- 
pits ; the face is red, and covered with fweat j 
the patient bends his body, fqueezes his belly with 
his hands, and falls into a ftate of fadnefs and de- 
jeftion. The progrefs of the difeafe is announced 
by obfcene difcourfe, indecent adlions, lafcivious 
motions, and an impoffibility of reftraining them. 
The patient, much altered, has a horror of food, 


devours it with avidity ; he vomits up a vifcld 
matter, and foams at the mouth, like a Hag in rut- 
ting- time. 

If the termination becomes fatal, a painful ten- 
iion is obferved in the abdomen ; a ftifFnefs or con- 
tra6lion of the limbs ; bodily motion is difficult; 
the pulfe is fmall, weak, and irregular ; and the 
difeale, become exceedingly rapid, may produce 
death in feven days. A cure is fometimes pro- 
duced after abundant mucous or bilious ftools, and 
vomiting of the fame nature. 

This difeafe, called fa Pyriq^s, is more common 
in warm countries, at the period of adolefcence, 
and among individuals who have a ftrong propen- 
fity to venereal pleafures. Aretasus, from whom this 
defcription is borrowed, appears to have had fome 
opportanities of feeing this afFeclion. He lived in 
a warm country, and among the Greeks^ a people 
who fcem to have carried to the utmoft extent 
every thing that could inflame the imiagination, 
and raife it to the higheft degree of exaltation. In 
our climates this difeafe is uncommon. 

183. The intelle6lual function, without appear- 
ing to be totally deranged, often exhibits evi- 
dent characters of exaltation, weaknefs, and very 
great mobility, which conftitutes a particular ftate, 
which we are now going to defcribe. 

During the firft period it announces itfelf by ha- 


bitual ladnefs, irafcibility, and watchfulnefs. The 
patient afterwards becomes fubjed to continual 
fears and fudden terror; his flcep is difturbsd by 
frightful dreams. He is rendered uneafy by the 
leafl trifle; falls into violent fits of paffion, fol- 
lowed by fpeedy repentance; exhibits traits of for- 
did avarice, and afterwards of the mofl lavifh pro- 
digality ; a taciturnity, interrupted fometimes by 
buriis of convulfive laughter; and, in a word, every 
thin^ that cbara6lerizes the utmofl ficklenefs and 

During the further progrefs of the difeafe, h^ 
entertains continual fufpicion and fear of poifon ■ 
his terror is every moment renewedj with conftant 
hefitation, averfion to mankind, abje6lion, love of 
folitude, whimfical, fantaflical, and fiiperftitious 
ideas 5 ridiculous complaints, wild flights of the 
imagination ; the delirium is fixed to one objedlj, 
which the mind purfues with the moft ardent per- 
feverance; and this delirium carries to the utmoft 
degree of exaltation the aiFe6tions which it pro- 
duces. Sometimes the patient fhows a deter- 
mined difgull to exiftence, and an irrefilitible pro- 
penfity to fuicide. This ftate is often the e£Fe61 
of an exaggerated idea of the misfortunes of lifcj of 
difappointment, and forrow : at other times it 
feems to __be the refult of too advantageous a fltil- 
ation in point of fortune, which places the indivi- 
dual in a flate where he has nothing further to 



hopCj or to fear ; which prefents no obflacle to be 
furmounted, and affords no field for new enjoy- 

Independently of thefe fymptoms, or of others 
eqiiall)/ lingular^ fome inciividuals exhibit an ex- 
alted fenfibility, fometimes perverted, and irregular 
returns of fpafms or convulfions, with an habitual 
delirium more or lefs flriking. Thefe paroxyfms, 
fufpended fometimes by other difeafes, re-appear 
during convalefcence ; they terminate fometimes 
in mortal fpafms, and at others in general con- 
fumption. ' 

Thefe fymptoms of alteration chiefly afFe6l per- 
fons who have a peculiar conflitution of body and 
mind: fuch as a meagre and withered appearance; 
pale, leaden, or yellowifh colour ; harfh and for- 
bidding gravity; chara6^er unequal and capricious; 
fquinting look, ftudied referve, ferious and thought- 
ful mien ; air of timidity and circumfpedlion, diffi- 
cult temper ; good appetite, but attenuation by 
watchfulnefs ; fometimes abftinence through the 
fear of poifon, withering and drying of the body, 
premature old age ; morofenefs ftrengthened by 
the progrefs of years. 

This, ftateis remarked, for the moft part, in tl]p 
age of virility ; it commonly begins in the fummer 
and autumn, and ends in the fpring. It is pro- 
duced by a concurrence of caufes highly various, 

VOL, III. w , as : 


as : exceffive fludy, religious fear, violent or un- 
fortunate love, profound grief, reverfe of fortune, 
the abufe of intoxicating narcotics, folitude, the 
interruption of an active life, idlenefs, luxury, efFe- 
minacy, and fatiety of all the pleafures of life. 

This Itate does not render confinement necef- 
fary, or produce a profound and acute alteration, 
which foon brings on death, or flowly terminates 
in real confumption. This afFedlion is often cured 
by a reverfe or an amelioration of fortune, a pow- 
erful diftradion, and by every thing that can ex- 
cite a lively intereft beyond the ordinary habits. 

This difeafe, the aggregate of the lymptoms of 
which conftitutes melancholy, fhows a great relation 
to that which remains to be defcribed, and with 
which it is often confounded. 

184. In a great number of alterations of which 
the intelledual functions are fufceptible, the moll 
ftriking iymptoms of derangement come on inftan- 
taneoufly by fits: their return, for the moft part, 
is irregular, and fometimes periodical. 

Mania, whether during the paroxyfras or dur- 
ing the ftateof calmnefsj prefents itfelf under dif- 
ferent forms, which depend on the mode of alter- 
ation in the fundlion of the intellectual organ. 
In general, the violent paroxyfms are never of 
long duration ; they always terminate, at the end 



of a longer or fliorter period, by a fort of calm, or 
milder mania : others exhibit a conftant ftateof in- 
fanity, or abfolute idiotifm. 

On the approach of a paroxyfm of mania, the firfl: 
effeS. which rcfults from the derangement of the 
cerebral organ manifefls itfelf, in particular, to- 
wards the abdominal region. A confliridion is 
obferved of the epigaflrimn ; loathing of food, ob- 
fttnate collivenefs, fenfation of burning heat in the 
inteftines, then in the breaft, and at length in the 
face, with a deiire for cooling liquors. 

Soon after, the individual exhibits extraordinary 
gefiiures, with lingular looks and movements. 
Sometimes there is an elevation of the head, with 
the eyes fixed on the heavens ; the lunatic fpeaks 
with a low voice, walks about, fuddenly flops, with 
an air of admiration, or of profound recolleclion. 
Sometimes he indulges in excefs of mirth, mani- 
fellcd by immoderate burlls of laughter ; at other 
times he falls into profound lilence, accompanied 
with an efFulion of tears, great fadnefs, and ex- 
treme anguifh. Very often he exhibits fudden al- 
ternations of immoderate joy and of the deepeft 
grief. In certain individuals, the eyes almofl; of a 
fudden become fiery and fparkling, and the cheeks 
colouredi which announces the neceffity of fpeedy 
confinement. In others, a fudden and incoherent 
flow of words is obferved, with frequent fits of 
laughter, torrents of tears, and foon after fury, and 
F 2 an 

63 llISTOlli' OF DISEASED. . 

an irrefiftible propenfity to violent and fangillnary 
adlions. In almofl all maniacs a fort of tranfient 
efFervefcence, and a real exacerbation, take place on 
the approach of ftorms, or in confequence of a very 
warm temperature of the atmofphere. They are 
then feen to run along with precipitate fteps, de- 
claiming without order or connection ; falling into 
a violent rage, without any caufe, or on the 
flighteft provocation, emitting loud and confufed 

The paroxyfms of religious mania are often pre- 
ceded by ecftatic vifions. Thofc of mania from 
love are preceded fometimes by enchanting reve- 
ries, and a fuppofed appearance of the beloved, 

Mania, in general, manifefls itfelf under the ap- 
pearance of a continued tranfport of anger more 
or lefs impetuous ; and it is much better charac- 
terized by thefe emotions of an irafcible mind, 
than by confufed or whimiical ideas. 

Some maniacs fhow a wonderful confi:ancy and 
facility in enduring the mofl rigorous and long con- 
tinued cold; fomeeven experience an evident enjoy- 
ment by the application of ice to the epigaftrium j 
but in many cafes their fenfibility for cold is exceed- 
ingly great, and inftances of the hands and feet of 
fome of them being frozen have at times otcurred. 
Some remain obftinately awake. In mofl: of them 
& nervous excitement, marked by a confiderable 



augmentation of raufcular force, with a ftrong 
convidlion that nothing can refift them, takes 
place ; they then difplay the utmoft intrepidity, 
and give full fcope to the moil extravagant ca- 

On many occalions they refufe all nourifhment 
for four, five, and even for fifteen days, provided 
they are amply fbpplied with drink. On the other 
• hand, they often experience a mofi fingular vo- 
racity, and fpeedily become faint when deprived 
of the ufual quantity of food. 

Warm feafons have a firiking influence on the 
return of the pqroxyfms, the duration of which is 
pretty generally confined within a certain period 
of from three to five months. They commence in 
that which follows the fummer folftice, continue, 
^ith more or lefs violence, during the beats, and 
terminate towards the end of autumn. In fome 
maniacs, however, the paroxyfms renewed at the 
end of autumn are continued throughout the win- 
ter, with remifiions or exacerbations according to 
the degrees of cold. Some cafes have occurred 
alfo, where the paroxyfms taking place in fummer 
have been renewed on the commencement of the 
cold weather. It may be readily conceived that the 
following caufes muft contribute to the renewal of 
the paroxyfms : tranfports of paffion excited ; the 
prefence of objedts calculated to revive in the mind 

r 3 the 


the original caufe of the madnefs ; the abufe of in- 
toxicating liquors, forced abflinence from food, &c. 

But fome paroxyfms are renewed at fixed pe- 
riods, without feeraing to be determined by any 
"known caufes*. 

Mania prefents itfelf under different forms, ac- 
cording to the nature and intenfity of the derange- 
ment of the intellectual fundlions. Thefe different 
forms may be arranged under the following four ' 
principal heads : 

ift. Weaknefs or exaltation of the hit ell eSlual fa- 
culties. The individual, in this cafe, difplays great 
levity, flupid abfence, impoflibility of keeping the 
mind fixed a few minutes on the fame objeCf ; lin^ 
gular inconfiftency and giddinefs ; continual mo- 
bility, attention to childifh occupations, weaknefs 
of memory, fudden flights, loquacity or tacitui-nity, 
a rapid feries of incoherent ideas, premature do- 
tage; and incoercible tranfports of 
paffion, ariUng from the nature of the organiza- 

* At the Bicetre a maniac every year experienced an attack 
which lafted three months, and which terminated towards the 
middle of fummer. Another was feized with a paroxyfm every 
two days in three, being always one day in a ftateof tranquillity. 
A third was in a ftate of the mofl; furious madnefs for fifteen 
days, and then remained in perfeft calmnefs eleven months and a 
half. Three others continued eighteen months without any con- 
fufion of ideas, or wildnefs of imagination j but for fix months 
after that period they were raving mad, 




tion, or a vicious education. During the par©x- 
yfms there are frequently obferved an exaltation of 
the ihtelle6lual faculties, great fertility of imagi- 
nation, a fort of infpiration and enthuiiafm for the 
greateft virtues, public and private. 

2d. Partial or injiantaneous aUeration of the in-r 
telleSlual faculties. In this cafe the imagination is 
exalted in an extravagant manner, or ftrongly im- 
prefled with fome erroneous idea ; the fenfes feem 
to receive the impreffion of obje^ls which do not 
cxifl*: in other refpe6ts the judgement is found, 
and the ideas coherent, even in regard to the erro- 
neous object. Childifh fear is often obferved, with 
great timidity ; and the utmoft miftruft, which in^ 
duces the individual to refufe every kind of food, 
and to remain awake ; alfo fanaticifm, and fond- 
nefs for the marvellous. During the parox^fms, 
the deranged movement and con fu fed agitation of 
the brain excite a propensity to deflruclive and 
even to fanguinary a(5i;ioris. Some individuals then 
imagine that they have an irreliftib.le delire to com- 
mit murder, confirm themfelves in this idea, iand 
deplore their condition -j". 

3d. Com- 

* Frequent inftances of this kind may be found in myftic \i*- 
fionaries, and perfons who imagine they every where fee poifon, 
monfters, ferpents, &c. ; who think their legs are of wax, qr- 
tb^j: pofteriors of glafs 5 who believe thenrfelves converted inta 
gnimals, prophets, deities, &c. 

f C. Pinel, io his ingenious work on madnefsj^from which wc 
F i^ have. 


^d. CompJele alteration of the intelleBual faculties^ 
In this cafe, the individual betrays a want of judg- 
ment in regard to all obje^ls, accompanied with 
aberration of memory. This ftate affedls different 
forms: the mania often feemsto confift in, a ftrong 
nervous excitement, a turbulent reftlefFnefs which 
admits of no repofe ; agitation^ cries, fparkling 
appearance of the eyes, obftinate watchfulnefs^ fu-? 
periority of phyfical firength^ ardour- for venereal 
pleafure \ a blind tendency to derange, break, tear^ 
and deftroy every thing, and even to commit fan- 
guinary adiions ; delirium of happinefs and joy, 
illuiions, extravagant flights of pride, in thofe who 
fuppofe themfelves to be generals, prophets, and 
deities ; fantaftic viiions. The maniac imagines 

have taken tlie materials of what has been here faid on this fub- 
je£l, is of opinion that the functions of the luill are difanct from, 
thofe of the underfanding; which is contrary to the opinion gene- 
rally eutertained refpefting the analyfis of the intelleftual func- 
tions. He gives the hiflory of a lunatic whofe periodical mad- 
nefs was announced by the mofi: fanguinary fury, which the. indi- 
vidual faid he was not able to reftrain. During his lucid interval? 
he deplored his miferable ftate ; continually fpoke of it, and be- 
came more and more confirmed in the idea that he had an irrefift- 
ible propenfity to murder : but this ftate was, no doubt, the 
ftffeft of a deranged inteile£t, and it is not more extraordinary to, 
fee a maniac with a perfuafion that he has an irrefiftible propen- 
iity to fanguinary a6tions, than to fee another impreiTed with a 
belief that he is a prophet or a king. In our opinion, this kjnd 
of maduefs may be affigned alfo to the province of moral me- 


he every where fees daemons, ferpents, poifon ; has 
a rapid fucceffion of ideas whicbfeem to arife from 
the firong excitement of the brain, without any 
relation to the impreffions made on thefenfes; 
with exuberance of words; tirefome loquacity; 
continual fucceffion of incoherent ideas ; tumul- 
tuous concurrence of different affediions and fen- 
fations, of joy, iadnefs and anger. 

4th. Annihilation of the mental faculties. In this 
cafe are obferved ; an inanimate figure, air of 
idiotifm, habitual fl:upor, infuperable ina6livity, 
-automatic motions ; foolifh and filly laughter, con- 
tioiial filence, or a few inarticulated founds; life 
merely aninnal ; no memory j the ideas and lan- 
guage confined to objecls calculated to fatisfy the 
pommon neceffities of life. 

In maniacs who have been expofed to violent 
^nd long continued paroxyfms, there are obferved, 
at the period when thefe paroxyfms terminate (for 
the moft.part towards the end of antumn), great 
vveaknefSi a fenfation of general Iafiitude,a faintnefs 
which often produces fyncope, great -corifufion of 
ideas; fometimes a real flate of ftupor, and almoft 
of infenfibility, with morofenefs of temper and 
deep melancholy. The unfortunate individual re- 
mains in bed, flretched out motionlefs, with the 
features altered, and a weak deprefled pulfe. In 
this iiate of atonia he runs the rifk of periiliing, 



efpecially if the cold be fevere, and unlefs the vital 
heat be maintained by cordials and the accumula- 
tion of bed-clothes. 

Obfervation induces us to clafs among thofe 
fubjccl to mania, perfons who fhow an ardent ima- 
gination and great fenlibility, energetic paffions, 
and the mod eftimable moral virtues. This affec- 
tion takes place equally at all ages. It is much 
more .frequent among vi^omen than among men, 
and fcarely ever is obferved among thofe who cul- 
tivate the exadl fciences. 

According to information acquired in regard to 
the former ftate of maniacs, it appearsthat we may 
coniider as the moft common caufes of this difeafe : 
a violent and unfortunate paffion, inordinate am- 
bition, reverfes of fortune, fanatical devotion, the 
delirium of ardent patriotifm. Aretasus includes 
alfc too liberal facrifices to Bacchus and Venus j 
and among the women, forced abftinence from 
the enjoyments of love, he, 

But, in general, there exifls no conftant rela- 
tion between the type, the fpecific chara61:er, or 
the intenlity of the mania, and the caufe or na- 
ture of the objedl which has primitively given rite 
to it. Thefe variations fecm. to depend more on 
the degree of fenfibility of the individual, and on 
numerous fortuitous caufes which affe6l his in^ 
telle6lual organ, exalted or Vvcakened. In gene- 



ral, a more irafcible difpolition, and tranfports 
which often border on raadnefs, are obferved 
among, thofe vigorous men, whom Cabanis de- 
fcribes with fo much truth and energy in the fol- 
lowing iketch*:—" Bolder and more ftriking 
looks, fparkling eyes, a dry and often yellov/ vifage, 
jet-black hair, fometimes frizzled j ftrong limbs, but 
is/ithout corpulency ; great mufcularftrength though 
in appearance llender; a meagre body, and pro- 
jelling bones; ftrong, hard pulfe. Thefe men," 
fays the author, " are continually hurried awaj 
by the torrent of their imagination and paffions. 
They wifli to carry every thing by force, violence, 
and impetuofity." On the other hand, more mo- 
deration is obferved in the mania of perfons with 
ehefnut-coloured hair, and of a mild and moderate 
character. Among fuch perfons, in particular, it 
is found under the appearance of a calm and peace- 
ful reverie, which often terminates in idiotifm, or 
3 fort of imbecility often incurable. 

Mania does not feem to arife from any known 
derangement of . the cerebral organ. The bodies 
gf maniacs, when opened, rarely exhibit any traces 
of very evident alteration in the brain. This dif- 
eafe feems rather to conlift in a diforderly move- 
ment, a weaknefs or too great mobility of the 
uervous adtion ; a real alteration in the intelle6lual 

* Memoires de I'lnftitut, an. vf, 

fundlions ; 


functions ; and it is proper to fee, with Stahl, fince 
imitated by Pinel, in the development and progrefs 
of the paroxyfms, all the phsenomena of falutary 
rea6lion. Vv e indeed obferve : abdominal fpafms, 
coloration of the face, accelerated circulation, ex- 
alted energy of the mental and bodily powers; the 
excitement of blind impetuofity, incoercible agita- 
tion. The underil:anding is hurried away by thc5 
force of thefe combined movements ; and after a 
certain duration, the extent of which is variable, 
there come on : a diminution of thefe phssno* 
mena, a depreffion of all the faculties of the indivi- 
dual, a progreliive return to reafon ; and the cure, 
in general, is the more probable as the paroxyfni 
has been more violent. It feems to be proved by 
obfervation, that of all the varieties of mania the 
moft obftinate are thofe which exhibit pure idiotifm, 
the imbecility and flupidity of the Cretins ; that we 
nDuit place in the next clafs continued mania, 
which does not prefent any ftriking exacerbation % 
in a word, that the hope of cure is at the higheft 
degree in periodical mania, and particularly in in- 
dividuals from the age of eighteen to that of 
twenty-five, v/ho pofiefs the greateft force of 
nervous rea61ion. Inftances of cure at an ad- 
vanced age rarely occur ; as if a fhock fo violent 
were above the powers of nature after the pe- 
pod of the greateft vigour. Sometimes the par- 


exyfrns gradualiy increafe, and at length become 

185. Will it Hill be the pra6iice to employ in- 
difcriminately bleeding, bathing, camphor, opium, 
&c. in the treatment of mania, notwithflanding the 
bad effe<5]:s which they are daily known to pro- 
duce ? 

" Madmen muft not be confidered as entirely 
deprived of reafon, and as inacceffible to every 
motive of hope or fear ; to every fentiraent of ho- 
nour. They muft firft be fubdued, and then en- 
couraged." Bihliotheque Briiannique, vol. viii. 

Tdconfole lunatics, to fjjeak to them with kind- 
nefs, to avoid by evafive anfwers a refafal. which 
might irritate them ; to overcome their obftinacy 
by inflexible firmnefs, without any a6l of violence; 
to guard againil exceflive complacency as well as 
ill-timed contradiction ; to infpire them with falu- 
tary fear, but always connected vv'ith a fentiment of 
efteem ; to remove every circumftance that might 
recall to their minds the primitive caufe of their 
madnefs, and which confequently might produce 
an exacerbation, or perpetuate its duration : fuch, 
perhaps, is the fum of the general means afforded 
by what may be called moral regimen. But the 
firft of all, no doubt, is to remove the lunatic from 
his ufual refidence, from the bofom of his family, 



where he might be conflantly fiirrounded by ob» 
je6ls connedled with all his habits, and from per- 
fons whole prefence might continually remind him 
of his misfortunes, of the caufes of his unhappinefs^ 
Sec. none of whom could fecond the exertions of 
the phyfician, and much lefs acquire Over the ma- 
niac, in an efFetlual manner, that abfolute empire 
which commands obedience. It is, therefore, in- 
difpenfably nccelTary, that fuch perfons fhould be 
,conveyed to public eltablifhments, where the bell 
poflible means are provided for putting in praflice 
ihis mode of moral treatment : fuch as very fpa- 
cious, folitary, and well fecured accommodations, 
where the maniacs when attacked by the par- 
oxyfms may be feparated, and be thus prevented 
from irritating each other, or from dilturbing 
thole who are in a flate of convalefcence ; and 
where they may be carefully watched under the 
infpedion of men who have acquired by pra6lice 
the proper methods of reftraining lunatics with- 
out violence, and without danger to them- 

Bat when it is known that moft of the public 
hofpitals for the reception of lunatics are ella- 
blilhed on the fame plan, and adopt the general 
method of fubjedting them to a uniform mode of 
treatment, by employing bleeding, the cold bath, 
and pretended calmers ; and that others are pro- 


vided for receiving them afterwards as incurable, 
and for locking them up like fo many favage ani- 
mals, it may readily he conceived how far fuch 
eftablilhments fall fhort of the perfc6lion to which 
they might be carried in confequence of the en- 
lightened ftate of the prefent period. 


[ 80 ] 





1 86. A MINUTE hiftory of the numerous dlfl 
eafes to which man in a ftate of fociety is fubjedl, 
and a knowledge of the caufes by which they are 
produced, evidently prove that the whole of them 
almoft have had their origin among individuals 
crowed together ; and that they are the refult of 
local influence, of the manner in which people 
are lodged, clothed, and fed, and of the varied em- 
ployment of the different fundlions. 

The human race are not fubjedl: to more dif» 
eafes than the other animals ; and every well-or- 
ganized perfon who refides in a falubrious coun- 
try, who enjoys a fufiiciency of wholefome nou- 
rifliment, who makes a proper ufe of his fun6lions, 
and who is fecured from every accident, experi- 
ences no difeafe, and dies of old age. 

Man in the favage and hunter ftate exhibits the 

type of the moft energetic organization. Being 

continually employed in exercifes -which call forth 

6 his 


his flrength and agility, and fed on the f]e(h of the 
animals he has caught, he finds himfelf under the 
two circumftances nioil favourable for acquiring an 
athletic conQitutiorii 

Though man, in confequence of the general; 
conftitution of his digeftive lyflem, is polyphagoils, -. 
animal food is that moll agreeable to him^ and the 
kind which he naturally prefers. The carnivorous 
favage acquires thofe habits of cruelty which are 
the neceffary refult of his mode of life^ and which 
are found among all animals that^ like him, feed 
on the produce of the chace. 

Ichthyophagi, fuch as are the greater part of the 
Finns, exhibit an organization much lefs robuft ; 
they employ patience and dexterity, father than 
ftrengttf and courage, to catch their prey^ and their 
food is lefs nourifhing and lefs falubrious. 

Nomades, employed alone in guarding the herds 
and flocks which fupply them with a milk diet, 
fuch as the fmall number of Tartars, who abftairi 
from flefh, do not polTefs that ftrength and dex- 
terity acquired by the exercife of hunting ; and in 
the wars carried on againft them by the hunter 
hordes, they always Ihow a very great inferiority 2 
in a word, confidering the exercife they take, 
milk to them is a fufficient and proper nourifli- 

In the laft place, thofe who live on|y on vegeta* 
bles, like the Indians, exhibit, at the fame degree 

VOL. Ill, Q of • 


of civilization, weaker conftitutions and mildef 

In thefe different ftates of ftrength and energy, 
if men are not crowded together in too great con- 
fufion; if they refide in temperate climates, habi- 
tually dry and free from marOiy exhalations, they 
all enjoy perfedl health, and arrive almoll uni- 
formly at death by old age. 

Bat, in proportion as men unite in fociety, dif- 
ferent difeafes, to which they afterwards remain 
fubje6l, are developed amongft them. 

187. Scurvy is one of the affe6lions firll ob- 
ferved amon^; riverian people, or thole who in- 
habit countries partly covered by Vv'ater. 

The continued adlion of cold moiftur^^ debili- 
tates their nervous llrength, and produces in them 
a fort of death at the furface of their bodies; the 
ildn grows pale, and' is covered with livid fpots ; 
exudations take place in the cellular tifllie ; it be- 
comes choked up, or decays ; the gums fwell, and 
are ulcerated ; they experience pains more or lefs 
acute, their limbs often fhrink, and they perifh in a 
fort of confumption. 

Men are the lefs capable of refifting the influ- 
ence of this humidity the more they are weakened 
by reft or fatigue, by the vi^ant of nourifhment, by 
the bad quality of their food, and by all thofe 
caiifes which tend to debilitate. 



That weak and debilitated conftitution which 
produces fcurvy is afterwards tranfinitted, in part, 
by generation. 

The fatal influence of continual humidity in a 
cold marfhy country may, in a great meafure, be 
corrected by human induftry : hence, to dig canals 
for the purpofe of giving motion to the ftagnant wa- 
ters ; to provide elevated habitations, better cloth- 
ing, found nourifhnnent, alcoholized beverages; to 
pay attention to cleanlinefsjand ufe proper exercife, 
are the beft means for preventing, almoft entirely, 
fcorbutic afFedlion in the dampefi; countries, as may 
be fecn in Holland. It is by employing a part of 
thefe means that navigators are enabled to prevent 
the fcurvy on board fhip during long voyages. 

W^xm-blooded animalsj and even a great num- 
ber of plants, experience affections analogous to 
tire fcurvy, by the continued atftion of exc^ffive 

i88. In the infancy of fociety, when men, as 
we may fay, are wanderers on the earth, without 
proper habitations; continually expofed to the in- 
temperance of the feafons in different climates; 
forced to an incetlant adiivity to infure their fafety 
and to provide for their wants, the organization 
becomes habituated to the impreffion of heat and 
cold, drynefs and moifture. 

The fkin, by its continual expofure 'to the air, 
G 2 and 


and by fucceffive fridlion againft different bodies, 
becomes indurated. The mufcular fyftem, by va- 
ried and extenfu'e exercife, acquires great force j 
and the lungs are habituated to inhale atmofpheric 
air at different degrees of heat and moifture. The 
fiiomach receives coarfe aliments, which require 
great labour to be digefled ; and it can bear 
without difficulty either an excefs of food or long 

In a word, a being who is thus continually fti- 
mulated by abrupt and frequent changes of his con- 
dition, and who isnot fubje^tedto the influence of 
any habit, acquires a conliderable force of organi- 
zation. In this ftate blows, falls, privation of every 
kind, heat, cold, and humidity, though carried to 
a very great degree, produce only very flight in» 
difpofitions. Every part poflefles a firong power 
of reaction; and all thefe organs, fo fine and fo de- 
licate, which feem fo eafily deranged, form by their 
pliability and adion a whole capable of refilling 
the moil powerful caufes of deftrudion- 

189. On the other hand, at a degree of civili- 
zation pretty far advanced, when men united in 
cities begin to have well built habitations which con- 
tinually fhelter them from the injuries of the air^ 
when their ildn is fecured by good clothing from 
the contaft of exterior bodies, and from the im- 
preflion of cold and dampnefs j when habit or do- 



meftic occupations withdraw them from the influ- 
ence of atmofpheric variations, their parts acquire 
a great fufceptibiHty for being affedled by every 
abrupt change. Their organization does not 
poflefs that power of readlion which oppofes the 
firft caufes of derangement, or which fpeedily re- 
moves any interruption that may have taken place 
in the fun6lions. Each organ is eaiily thrown into 
diforder, and the derangement which continues, 
for v/ant of the ftrength necefTary to repair it, foon 
becomes itfelf the caufe of a new afFe6lion ; and 
hence we often fee a fucceffion of different de- 
rangements produced by each other, all arifing 
from one flight caufe, which nature had not power 
to overcome, and which art is not able to prevent. 

190. The violent and unufual impreffion of any 
caufe whatever on organs eafily irritated, produces 
numerous ^blegma/ice. 

The phlegmafia of any organ always confifls In 
a change in the flate of the fun6lion peculiar to it, 
with an alteration*in its intimate ftrudure. 

It may be readily conceived that every part of 
the body is fufceptible of this mode of affection ; 
that each muft exhibit it in a manner peculiar to 
itfelf; and that the fame organ may prefent a great 
number of varieties in this order of difeafes. 

The greatefl: and mofi: important difference in 
the phlegmafies arifes from their progrefs. Some 

G 3 proceed 


proceed in a rapid manner, foon produce a general 
derangement, and either terminate at the end of a 
fhort and hmited period, or are changed into 
chronic afFe(5lions. Others are exceedingly flow 
in their progrefs, and in the courfe of time often 
produce very great alterations, without having 
been obferved at their commencement. It may 
be eafily conceived, that between thefe two ex- 
tremes there mufl be a great many intermediate 

Phlegmafias vary in the different organs, and in 
the analogous parts are the fame ; fo that the dif- 
ferent anatomical fyftems of organ sfurnifh the na- 
tural divilions of this clafs of difeafes. 

It may, indeed, be readily conceived that a mu- 
cous membrane, for example, mufl be affected in 
an analogous manner, whether it ferves to form 
part of the aerian, alimentary, or genito-urinary 
pallages. The cafe will be the fame in regard to 
the ferous membranes, the cellular tifTue, the bones, 
the mufcles, the fkin, &c, 

191. We fhall here take a curfory view of the 
different kinds of phlegmafias ; beginning with 
thofe which appear to be fimplefl. 

When, the fkin has been divided or cut, the 
edges of the wound tumefy, and become red and 
painful ; the heat and circulation in the part are 
increafed„ Thefe firfl phsenomena refull from the 



laceration of the nerves. Soon after the e(lo;es of 
the wound Jecrete a vifcous fluid, which is efFufed 
between the lips of it, and caufes them to ad- 

When the divifion is very fmall, and does not 
reach beyond the Ikin, the union nnay be effedied 
in a few hours. On the other hand, when large 
and deep a much longer time is required j but, in 
all cafes, it is fooner eifedled according as the 
union of the edges has been more exa6l, and as 
the individual enjoys a better ftate of health. 

The edges of the wound may unite, even though 
they have fuftained a violent contufion ; though 
they have remained feparate for feveral days, and 
though they retain between them .coagulated blood : 
fo that it is always proper to try to efFe£l an union 
by the means which the art of furgery indicates in 
fuch cafes, as long as the part is not afFeded by a 
general phlegmafia. 

Almoft all thofe topics which are employed to 
favour the union of wounds are at leaft ufelefs. 

When it has not been poffible to unite a folu- 
tion, the edges fecrete a vifcous fluid.; cicatriza- 
tion takes place flowly, and in the manner of 
wounds with a lofs of fubftance. In the latter, 
as in cafes of fimple diviiion, the phcenomena 
arifing from la^fion of the nerves, and their expo- 
fure to the air, firft take place ; the fecretion then 
becomes more abundant, and the wound grado- 

G 4 ally 


ally cicatrizes from the circumference to thecentre, 
by the formation of a new epidermis. 

When nothing but the epidermis has been re- 
movedj as is the cafe in flight burns, cicatrization. 
is fpontaneoufly effedled in every point at the fame 

The method mod proper for favouring the cica- 
trization of a wound is to apply nothing to it. This 
iTiethod, which is certainly the lirapleft, is perhaps 
Ihe only one which has never beeq thought of. I 
have obtained yery rapid cicatrization by covering 
ulcers with a pierced dreffing. By thefe means 
they are defended from the contadl of every body, 
and from the impreffion of the atmofphere^ while 
the air is allowed to circulate at their furface : the 
air carries off the hurnidity difengaged^ and which 
by remaining oppofes cicatrization. 

The ^us^ called laiidahle, which is formed In all 
deep wounds^ is not produced at the fiirface of 
thofe which are left expofed to the air. The for- 
mation of this pus is. promoted and maintained by 
the application of the foreign body which covers 
it. Thofe which remain expofed to the air fufFer 
to e'^ude from them a fmall quantity of vifcid. fe- 
rous matter, which becomes dry, and below which 
the epidermis is formed. 

There are a great number of cafes in which it 
is found necefTary to cover wounds. The laws of 
phyliology, like thofe of philofophy, can rarely be 



applied In their whole extent; but whatever method 
be adopted, thefe laws mull always be employed 
as a guide. 

Thus, in every cafe where dreffing is requifitc, 
it muft never be forgotten that the moft beneficial 
Gourfe, when poflible to be followed, is to apply 
nothing to the wound ; and therefore the leafl 
irritating fubflances ought to be ufed, thofe befl 
calculated to abforb the pus which is formed muft 
be chofen, and care fhouid be taken that they do 
not adhere to the edges where cicatrization is 
taking place. 

No topics have the property of battening, in a 
dire6l manner, the cicatrization of wounds, and the 
beft vulneraries are thofe which do the leafl hurt. 
However, when the wounded part is in a ftate of 
weaknefs which retards the procefs of cicatrization, 
all flimulants may become ufeful vulneraries. 

Wounds cicatrize the fpeedier the frefher they 
are, and the founder the conflitution of the indivi- 
dual. It will therefore be proper, in all cafes, to 
endeavour to bring them back to the recent ftate, 
and to refiore firength to the organization. The 
appearance of a wound may always ferve to indi- 
cate the ftate of the individual's health. 

When an ulcer has been of long ftanding, either 

in confequence of the individual's bad health, of 

the peculiar weaknefs of the wounded part, or of 

any local irritation whatever^, nothing is fecreted 

J but 


but fanious and fetid pus 3 its edges become hard 
and callous, the adjacent part aflumes a violet co- 
lour, and at length lofes its former fcnfibility» In 
this ftate of things, it will fometimes be proper to 
make a new wound in the old one, in order to pro- 
duce cicatrization, 

192. Phlegmafia of the cellular tifiue exhibits, 
in the formation of phlegmon (tumour), a feries 
of phaenomena the progrefs of which may be 
eafily followed. 

When a thorn is introduced beneath the fkin, 
the individual immediately experiences an acute 
pain, which gradually ceafes ; but fome days after 
there comes on around the prick a flight rednefs, 
with fwelling and heat, and the pain is renewed. 
Sometimes, alfo, a general derangement of a flight 
and tranfient nature takes place. 

If this new mode of a61ion continue, the fwell- 
ing increafes and fpreads; a flight tumefadion of 
the neighbouring lymphatic glands takes place : 
a fmall tumour then arlfes, which becomes white, 
breaks in the moil prominent part, and affords an 
ilTue to the pus, which carries with it the thorn. 

The prefence of the thorn was not neceflary to 
give rife to all this feries of phasnomena ; the 
prick alone would have been fufHcient to produce 

Hence, the prick of a needle often produces 



plilegmon, efpecially in perfons highly irritable, 
weak, or difeafed, and who, in this cafe, are faid 
to have hadflejh. 

Inoculation with the vaccine matter produces 
alfo the fame feries of general phaenomena, and 
the phlegmon arifing from it exhibits a conftant and 
invariable progrefs j becaufe the fubftance which 
occafions its development is always of the fame 
nature. The cafe of the thorn, that of a fimple 
pundlure, and of the vaccine inoculation, exhibit 
nothing common or efTential but the prick, or the 
impreffion made by conta6l on the nerves of the 
wounded part. 

Every prick in a nerve produces a change of 
ftate, more or lefs continued, in the general adion 
of the nervous fyftem : when this new mode of 
action is continued on the wounded part, it gives 
rife to phlegmon. This change of ftate is often 
only momentary, and fo tranfient as fcarcely to be 
perceptible. But in many cafes it manifefls itfelf in 
an evident manner by a general indifpoiition, and 
the peculiar derangement of diffei^ent functions. 

In all cafes of pricking, as the prefence of the 
foreign body in the part, and its tranfmiffion into 
the mafs of the blood, are not necefTary to produce 
the general derangement and particular formation 
of the phlegmon, the hypothefis .of abforption is 
entirely unfupported by proofs. 



Of the numerous caufes of phlegmafiae, tbofe 
which exercife the greateft a6lion on the nerves 
are, in general, the fubftances fecreted or difen- 
gaged from organized bodies in a ftate of difeafe or 
of putrefacflion. 

Hence, after a prick made in diilecling a dead 
body in a high flate of putrefadion, that is to fay, 
by the contaft of the cadaverous moleculas, at a 
certain period of decompoiition, with fome of the 
nerves of the hand, there may take place in the 
courfe of a few days rednefs, fwelling, heat around 
the wounded part, and then ihooting pains, which 
gradually increafe in a continued manner, fo as at 
length to become infupportable. 

Thefe firft local pha^nomena are foon followed 
by a general derangement of the fundions. Hence, 
there come on : pain in the head, weaknefs and 
confufion of the fenfes, tranfient delirium, pro- 
ftration of ftrength, fhivering, acceleration of the 
pulfe and of refpiration by paroxyfms; greater 
heat of thefkin, fweats, lofs of appetite, new mode 
ofa6iion in moft of the organs of fecretion, &c. 

This feries of phsenomena, which affume the 
name of fever, vary indefinitely, according to the 
caufes, and to the difpolition of the individual. 

After the fwelling has acquired a certain degree 
of intenfity, it gradually fubfides, as well as the 
febrile fymptoms : if the latter continue to in- 


creafe there is formed a co]Ie(5lion of pus, which is 
fometimesre-abforbed, or which diftends the fkin, 
burfts it, and is difcharged. 

But when the weaknefs is exceffive no purulent 
colle6lion is formed ; the progrefs of the phlegmon 
is fufpended, and it may happen that the wounded 
part will gradually lofe its a6lion. It then afTumes 
a blueifh, livid tint, becomes indolent, and falls 
into a ftate of gangrene. 

In the laft place, if the flrength is re-eftabli(hed, 
and if th^ febrile fymptoms ceafe, the wounded 
part gradually refumes its vitality, the dead parts 
detach themfelves, and there remains an ulcer 
which cicatrizes ilovvly from the circumference to- 
wards the centre. 

Phlegmon being an afFedion peculiar to the 
cellular tiffiie, it may take place in all the organs 
provided with it. Its fize varies, from the puflule 
fcarcely perceptible, to the tumour which contains 
- fometimes more tlian a pint of pus. When the 
phlegmon pafles through all its ftages it termi- 
nates in an abfcefs ; but it may flop at any of its 
periods : abfcefJes which already contain a large 
quantity of pus. are often feen to difappear in a 
fhort time. In this cafe, the purulent matter has 
been decompofed or digefled, and transformed into 
moleculae fufccptible of returning into the torrent 
of circulation, or of being thrown out by the ufual 
excretory pafiages. 



The progrefs of phlegmon is generally ftopped 
when there comes on a fudden derangement in 
ibme other part : the coincidence of thefe twp 
phsenomena has given reafon to think that the 
pus proceeds to the part newly affe^ledj to produce 
there, by its prefence, the fymptoms before ob- 
ferved. From this circumftance the whole theory 
of metaftafis has originated. 

Thus, for example, a man has on his thigh a 
phlegmon which begins to enter into a ftate of fup-- 
puration j boiling water falls upon one of his legSj 
and the tumour difappears. The latter may be 
diffipated alfo, if he experiences a violent cold, or 
meets with any unexpe<5ted event in which he is 
deeply interefted, and which engages his attention 
for fome time. In all thefe cafes, the pus of the 
phlegmon has not proceeded to the legs, nor to 
the breaft, nor to the intelle6lual organ : thefe 
are only varied phsenomena of the nervous adlion, 
which fucceed each other, and afTume each other's 
place according to the ratio of their intenfity. 

In all cafes of phlegmon, the produ6^ of the fe= 
cretion becomes an irritant, Vvbich may at length 
give rife to further ace icier ts : thus its continued 
prefence around a bone p;-: - profluce caries, Sec. 

From thefe obfervatior : it is clearly {een how 
ridiculous it is to be cor:" nually endeavouring to 
make a phlegmon fupp;jrate; which always pro- 
longs tfie difeafe, and cnen produces ugly-cica- 
trices, without any advantaf^e, 

8 ^ Pretended 


Preiended refolvents and difcutients, habitually 
employed, feldom produce any adlion. A phleg- 
mon may be checked in its progrefs by all thole 
means which are proper for determining a flrong 
and continued a6lion towards another part. 

In' a word, it often happens that nature fports 
with all our means, and brings to fuppuration 
thofe tumours which we are defirous of fufpend- 
ing, and fufpends^thofe which we wiHi to bring to 
a ftate of fuppuration. 

A phlegmon may take place not only in the cel- 
lular tiffue furrounding the different parts, but alfo 
in the parenchymatous fubftance of fome of the 
organs, fuch as the lungs, the liver, the kidneys, 
&c. It then exhibits numerous varieties which 
depend on the ftruclure of the aiFedied organ, on 
the difpolition of the individual, on the rapid or 
flow progrefs of the phlegmon, &c. 

A part may be afFe6lcd without any diredl im- 
prcflion, and merely by means of its relation with 
other organs. Hence phlegmonous tumours are 
not always the refult of the acftion diredlly exer- 
cifed on the nerves of the part where they take 
place ; they often arife from a remote caufe : of 
this kind are thofe formed around the glands at 
the end of feveral acute difeafes, fach as buboes in 
iyphilis, &c. 

In all cafes of phlegmon the termination is the 



fpeedier as the conflitution of the Individual af- 
fe(5ted is (Ironp-er. 


In the different clailes of yertebral animals, the 
cicatrization of wounds, the development and pro- 
grefs of phlegmonous tumours, are abfolutely the 
fame as in man, and exhibit no eflential difFerence.- 

193. The ferous membrane which lines the tho- 
rax, the abdomen, the cranium, and the articular 
capfules ; which covers the Tungs, and forms the 
exterior tunic of the Homach, the inteftines, the 
bladder, the matrix, &c. exhibits in its phlegmalic 
afFedlion peculiar phaenomena. 

This affedion, in its rapid progrefs, produces 
excruciating pain, and fuddenly gives rife to a 
leries of febrile phaenomena exceedingly violent 
and almofl continued. 

The afFe(5^ed membrane fwells ; and, inf^ead of 
the fluid which habitually exudes from it, fecretes 
in abundance a thick albuminous fluid, which coa- 
gulates into flakes or lumps that float in the fero- 
lity, or into a thick membrane, which produces ad- 
hefion between the contiguous furfaces of the fe^ 
rous membrane. 

The albuminous fluid fecreted in phlegrnafia of 
the peritoneum is found in curds araidll: the ferous 
fluid of the abdomen, and refembles, in fome mea- 
fure, the concrete cafeous part of milk floating in 



the ferum. After difficult births, the matrix fomeif 
times experiences a fort of phlegmafia, which 
fpreads along the peritonaeum, and gives rife to a 
fever which often proves mortal {puerperal fever). 
Several phyficians have confidered the albuminous 
fubftance then found in the abdomen as effufed 
milk ; but this fuppofed milk is found in men as 
well as in women, after all thofe phlegmafiae of the 
ferous membranes of the abdomen which have had 
9. fatal termination, and particularly after the ope- 
ration for a ftrangulated hernia. 

It feems probable that the vulgar error of milk 
difFufed throughout all the parts of the body, has 
arifen from this erroneous idea, that milk is fufr 
ceptible of being effufed into the abdomen. It is 
aftoni{hing to find perfons of good fenfe who con- 
flder rheumatic pains as the efFe6l of effufed milk, 
and who ferioufly believe that there are remedies 
capable of cauling the milk in its curdled ftate to 
be evacuated by flool, even a great number of years 
after the individual has been delivered. 

Acute phlegmafise of the ferous membranes are 
always dangerous, and often fatal. It is of great 
importance, therefore, to difcover them at their 
commencement, in order that 4he means proper 
for eradicating them may be employed. The 
principal means on which a dependance can be 
placed are, to weaken the general a6tion of the 
nervous (}ftem, when the fever exhibits no perni- 

VOL. iir, H cious 


clous character, like that called the puerperal j and 
to excite ftrong, continued, and varied irritation 
in other parts than that which is afFe61ed. 

The ferous membranes may alfo be the feat of 
chronic phlegmafias, which increafe very llovvly ; 
which are ■ almoil always miflaken at their com- 
mencement, and over which art has very little 
power. ' ■ ' 

Domeftic animals are iubjedl to acute afFetftions 
of the ferous membranes, which exhibit a feries of 
iymptoms analogous to thofe obferved in man. 

^-^ 194, The white fibrous tifllies which terminate 
the mufcles and furround the articulations experi- 
ence a fort of phlegmafia, which for the moft part 
feems to be produced by the long continued a6lion 
of a particular damp cold. It rarely attacks ro- 
buft perlbns continually expbfed to the incle- 
mency of the feafons ; but more readily the 
inhabitants of large cities, of a weak conftitution, 
and who are feldom expofcd to the adion of the 

This, rheumatic afFe61ion announces . itfelf by 
a fort of painful torpor in a certain part, which 
increafes fometimes to fuch a degree as to be- 
come a lacerating pain. It is often accompa- 
nied by fwelling with rednefs, great fenlibility of 
the Ikin, and difficulty in the mufcular adlion. 
Thefe firft fymptoms are frequently attended 
4 with 


With a feries of febrile phacnomenaj which are 
often exceedingly violent. r..-, 

One peculiar charadter of this' a'^'^^idn is, that 
it iiiddeniy ihifts, or ceafesiii -one part to re-ap- 
pear i'n aiiother. It thus often fiiovvs itfelf alter- 
nately' in iall' the-EPPtieulatio'ns^ and even returns to- 
the firft. 

Rheumatifra varies, both in regard to its dura- 
tion and to its intenfity, from a' limple fleeting 
pain, which fcarcely lafts^afeyv^ days,- t-O a general 
afFe6lion which cotifih'fes thfe itidividtt&l to bed for 
iive or fix weeks. 

After parturition^ women being weak and-ex- 
cieedirigly ferifible to cold, frequently experience 
rheumatic affe61ions, which by fome are confi- 
dered as effh/hd milk i' 

• Rheamatifm often takes place without febrile 
iymptoms, and without fwelling of the parts. In 
this cafe, it announces itfelf by pains, more or lefs 
acute, which return by paroKyfms, and fometimes 
become intolerable* 

In fome cafes thefe pains give rife to a fwelling 
of the periofteum of fome of the parts, and are then 
generally confidered as lymptoms of fyphilis. 

It is to be remarked,, that it is always to fyphilis, 
01* to the pretended ejfufed irulk^ that all thofe dif- 
eafes the character of which cannot be ealily de- 
termined are afcribed ; and when cured by the 
means ufed for fuch affedlions phyficians think 

H 2 themfelves 


themfelves authorized to fay: ''Such a difeafc 
yielded to mercurials, confequently it was vene- 
real ; fuch another difappeared in confequence of 
ufing thofe purgatives called antila^ics, and there- 
fore it arofe from effvfed milk." Thofe who reafon 
in this manner evidently fhow that they are ba4 

When rheumatifm afFe6ls the articulation of the 
ribs and the intercoftal ligaments, the movements 
of the thorax are impeded, and the difficulty of 
refpiration frequently becomes very great ; which 
often occafions error, and excites apprehejnfionQf 
a difeafe of the lungs. 

The fmall articulations exhibit in the gout an 
affedlion analogous to rheumatifm ; but which, 
however, is very different from it in the aggregate^ 
of its accefibry phaenomena, of its caufes, &c. It 
contracts a fort of regular or irregular periodicity, 
with an uniform or anomalous progrefs. 

The adtion of the damp cold which excites 
phlegmafife of the white fibrous membranes, often 
produces thofe alfo of the mucous membranes ; fo 
that thefe two orders of phlegmaliae fometimes 
take place by alternatiooj and reciprocally fufpend 
each other : which occalions a belief that in this 
cafe alfo the humour proceeds from one part to 
another. Thus it has been fuppofed that the gout 
can afcend to the llomach, or proceed to the blad- 

derj 8cc. 



Acute rheumatirm is fometimes checked at its 
commencement by means proper for diminifhing 
the powers, and by exciting in the gaftric organ 
a point of irritation frequently renewed. 

The pains of chronic rheumatifm are diffi- 
cult to be removed. They appear, however, to 
have been diminifhed by an increafed a(9:ion of 
the fkin, and of perfpiration, by means of dry fric- 
tion, clothes of waxed tafFety, &c. 

In a word, this order of difeafes exhibits alfo 
feveral very ohfcure points, which are deferving of 
farther obfervation. 

As this order of difeafes is excited, for the moft- 
part, by the unaccuftomed adion of damp cold on 
feeble individuals, animals which, in general^ exhi- 
bit more vitality, and which are habituated to all 
the variations of the atmofphere, do not feem to 
be fubjed to them. 

195. As the eflential ufe of the mucous mem- 
branes is to fecrete fluids proper for lubricating 
the pneumo-gallric and genito-urinary paflages, 
and to furnifh digeftive juices, the phlegmatic of 
thefe parts muft manifeft themfelves chiefly by 
a change in this mode of fecretion. 

When a part of the mucous fyftem has received 
the impreffion of any foreign caufe whatever, either 
dire6t or indireft, a fenfation of flraitnefs, drynefs, 
and ardour, is experienced in that part. The habi- 
tual fecretion is fufpended, the tides of the mucous 
H 3 organ 


organ fwell, febrile fymptoms appear, and in a few 
days tbere is fecreted a large quantity of a ne\y, 
limpid, and higbly irritating fluid. 

As the other febrile fymptoms difappear, the pro- 
du61; of this new mode of adlion becomes infenfibly 
thicker, and Igfs irritating; the mucous organ 
gradually rdlimes its uilial fun<51ion, and fecretion 
its natural chara61er. 

In this order of difeafes the new fecretion always 
itrongly irritates the organs on which it is eifuled, 
and produces further accidents, variable according 
to the ufes of thefe organs. It is this fecretion 
which ocpalions fneezing in coryza ; cough and 
difficulty of breathing in colds; tenefmus in dy- 
fentery ; frequent deiire of voiding urine in gonor- 
rhoea, &c. 

The peculiar fecretion which refults from this 
new mode of adlion was long confidered by phy- 
licians as the direct caufe of the difeafe, while 
it evidently appears that it is only the prpduft 
of it. 

They were of opinion that the difeafe arofe from' 
a. humour which infected the mafs of the fluids, 
and that nature endeavoured in this manner to 
free itfelf from it. 

This hypothefis miaft have firft been formed at 
a time when phyfiological knowledge was very 
limited : on it was founded humoral medicine, 
which was eafily applicable to all difeafes. It was 
indeed fuppolcd, that as a humour evidently ap^ 



peared .to be the caufe of difeafe in catarrhs, ; it 
might exlft alfo in all other cafes, though in .a 
manner lefs apparent ; and every time that a fpon- 
taneous alteration took place in the ftruStiire or 
fundlioti of an organ, it was faid that the morhljic 
humour had proceeded thither. 

This theory foon obtained credit, and at length 
became popular, becaufe it was exceedingly con- 
venient to account for every thing to perfons who 
had no idea of the laws of organization, and be- 
caufe the means of cure moft commonly employed 
feemed very often to fupport it. 

In the fuppofition of a humour which proceeds 
to a certain part and deranges its action, it was 
natural for phylicians to endeavour to divert it, by 
making it ifTue through the Ikin, or by evacuating 
it by ftool or by urine ; and as they were obliged, in 
order to produce this effe^, to irritate very ftrongly 
fome other part, they in this manner often deflroy- 
ed the foreign action which conftitutcd the difeafe. 
But it riiay be readily conceived that this practice, 
founded on a falfe theory, muft have as often proved 
fatal as beneficial. 

The new mode of a6tion which is efiablifhed in 
catarrh may be fufpended, in the commencement, 
by all thofe means capable of exciting a powerfql 
and continued atSlion in Ibme other part than the 
affected membrane. For this reafon, emetics em- 
ployed fo as to produce naufea, and repeated feve- 

H 4 ral 


ral times, fucceed fo often in catarrhs of the aerlaa 

* ; This new mode of a6lion may be changed alfo 
hf applying to the affeded membrane a new irri- 
tant, more energetic or frequently repeated. In 
perfons of a good conflitution, catarrh terminates 
fpontaneouily at the end of a period which varies 
from fome days to fome months, according to the 
organ affedled, the nature of the irritant, and the 
difpofition of the individuals, &c. 

Catarrhs may be indefinitely continued by the 
repeated application of the fame irritants which 
produced them ; by local or individual weaknefs, 
and by the force of habit. 

The caufe which for the moft part produces 
catarrhs of the aerian paflages (colds), is the fud- 
den impreflion of damp cold air, in a ftate yet un- 
known, on the nerves of thefe parts. Perlbns of a 
weak conftitution, and not accuflomed to breathe 
this air, receive the impreflion of it fooner than 

The a£Hon of this damp and cold air on the 
aerian paflages is flronger, according as the tempe- 
rature of the Ikin is higher ; fo that people will 
more certainly be attacked, the more they endea- 
vour to fecure themfelves by the common means. 

To remain, therefore, in winter continually fliut 

lip, to be always warmly clothed, or to go abroad 

when heated, are the fure means of acquiring tlie 

8 difeafe 


difeafe by the firfl impreffion of cold damp air on 
the lungs. On the other hand, thofe thinly clothed, 
thofe habitually expofed to the air, and thofe who 
avoid overheating themfelves, are fcarcely evef 
fubjedl to colds. 

Theadlion of the cold damp atmofphere may 
jifFe(5l a ^art of the mucous fyftem, without mak- 
ing a direct impreffion on it, but by exercifing an 
adion on a diftant part. Hence, damp cold in 
the feet produces catarrh of the aerian paflages, 
and often alfo of the inteftinal furfaces. 

We are taught by obfervation, that the oftener 
people have been attacked by catarrh, the more 
readily they are alfeded by it ; and that the lon- 
ger a catarrhal difpofilion has continued, the more 
difficult it is to be deftroyed. 

In gonorrhoea, the produd of thfe fecretion is 
contagious, iand the application of it to the genito- 
urinary membrane of another individual produces 
the fame affedlion : the latter, in like manner, may 
be propagated indefinitely by means of contad. 

It is, in all probability, the contagious charader 
of this fort of catarrh that renders its progrefs fo 
tedious,, and its termination often, fo difficult, 
when left to itfelf, in individuals of a weak con- 

This urethral catarrh may be cured pretty foon 
by means of ftimulatifig injedions, which change 



the contagious mofje offecretion into anotljer not 

When catarrhs are frequently renewed, or have 
continued a very long time, they often give rife to 
chronic affedlions exceedingly troublelome : of 
this kind are callofities in the urethra, leucorrhoea, 
vefical catarrh, catarrh of the aerian paffages, 
phthifis pplmonaris. 

In thp Jaft mentioned cafe, when continued 
emundories are eftabhfhed (cauteries, veficatories), 
with the intention of producing a derivation of a 
humour^ the only effe6l obtained in general is, to 
have two difeafes inftead of one ; and both tend 
equally to weaken, by drawing off juices rich in 
nutritive parts, and more fpeedily bring on con- 
fumption . 

Domestic animals are pot much ful^jedl to ca- 
tarrhal afFedtions, becaufe they are more habitually 
cxpofed to the variations of the atmofphere ; but 
thofe which, by a peculiar firu61ure of their nof- 
trils, are apt to have the glanders, exhibit in that 
fort of coryza a catarrh much more troublefome 
than any of thofe which affedt the human fpecies. 

196. The mucous membranes which line the 
pneumo-gadric and genito-urinary paflages, arp 
continued with the fiiin on the edges of different 
natural apertures \ and it might be faid^ that in 



thefe part? the Jatter is folded back to line thefe 
different cavities. . It is obferved, alfo, that the 
cutaneous and mucous fyftems have a> great rela- 
tion in their reciprocal fun<51ions. 

It cannot, however^ be denied, that tliefe tw^o 
l}'ftems of organs exhibit very flriking differences 
in their intimate flfu6iure, efpecially during va- 
rious difeafes to which they are fubje6l. 

Affedlions of the ildn exhibit a new mode of 
a6lion and fecretion, with or without alteration ia 
the intimate flru6lure of that organ. 

They may arife merely from the fecretion of the 
ikin being increafed or changed ; or they exhibit 
themfelves under the form of eruptions, of divers 
forms and fizes ; of phlegmonous pullules ; furfu- 
raceous, fquamous, fcabby, or ulcerated fpots. 

In fome cafes, the produdt of the morbific fecre- 
tion is contagious. 

In robuft individuals,, whofe Ikin is continually 
expofed to the air, this organ becomes brown and 
, tanned, infenlible to all imprcffions of the atmo- 
fphere, and is iiibje(5l to no difeafe. 

Qn the other hand, cutaneous affections are 
pumerous among the civilized nations of tempe- 
j-ate or warm countries, who live in a luxurious 
manner, and whofe Ikin habitually Ineltered is 
highly feniible to the adlion of all irritants which 
come in contact with it. They are more fre- 
(juent, alfo, among individuals who, being born 



with thefe difpofitions, remain in a date of po- 
verty and dirtinefs. The latter are expofed to a 
great number of foreign irritants, and to the re- 
action on the cutaneous organ of the produds of 
its fecretion. In fome cafes of denudation, or of 
difeafe, this produce often exhibits an exceedingly 
acrid and highly irritating chara(5ter. It is pro- 
bable, that a concurrence of analogous circum- 
iflanccs has given rife to the greater part of cuta- 
tJeous difeafes. 

It appears that the Greeks preferved themfelves 
from difeafes of the fkin, which among them were 
exceedingly frequent and fevere, merely by the 
habitual ufe of bathing and of un<5lions. 

Bathing ilrengthens the Ikin by habituating it to 
the conta(5l of a fluid eight hundred times denfer 
than atmofpheric air, and cleanfes it from the 
produ6^s, more or lefs irritating, of its fecretion. 
Ointments, like a light varnifli, preferve it from 
the too immediate conta6t of a great number of 
foreign and Simulating fubftances, without in any - 
manner impeding its excretion. 

It is well known that the Grecian baths were 
eftablifhments exceedingly magnificent, and that 
they conftituted the mofl remarkable of their 
public monuments. 

Cutaneous afFedions, in fome cafes, are the 
necelTary confequisnce of an epidemic or fporadic 
fever ; in others, they are the refult of a foreign 



mode of adlion excited in fome of the or- 
gans * : but, for the moft part, they arife from 
the immediate adlion of fome irritants on the 
£kin ; and in all thefe cafes they vary as the 
caufes which produce them. 

Moft cutaneous afFedions terminate fpontane- 
oufly at the end of a certain time, and require no 
treatment. Others are indefinitely continued, 
during an unlimited time, either by the force of 
habit, or by the repeated contadl of the contagi- 
ous produ6l of fecretion. In fuch cafes, the phyfi- 
cian endeavours to fubftitute in the place of thefe 
obftinate afFe6lions, others which do not exhibit 
that character, and which cure themfelves fponta- 
neoufly, and to produce in another organ, fuch as 
that of digeftion, a ftrong and frequently renewed 

The itch is an eruption without fever, the pro- 
duct of which is contagious. It is readily pro- 
pagated by means of contadl, efpecially among 
perfons a prey to wretchednefs and dirt, among 
whom it becomes, in fome meafure, endemial. 
It is cured by all thofe means proper for excit- 
ing in the fkin another mode of adlion, fuch as 
friction, and all irritating fubftances. A recent 
itch may be fpecdily removed ; but the longer it 
has continued the more difficult is the cure. 

* Dr. Lorry always experienced a cutaneous eruption whcii 
he ate rice. 


llO REFLEcflONo ON Til£ 

Among pcrfons who have a deihcate fkin, fric- 
tion for the itch foon produces another eruptioflj 
which' the furgeons cOnfidcr as pforic. This new 
eruption, which may be afterwards rhaintained by 
dirtinefs and ufelefs friiiions, has often been cOn- 
fidered as an obfl;inate itch, and as fuch has been 
feveral times treated without fuccefs ; but it al- 
ways yields to means proper for allaying the irri- 
tation of the fliin, fuch as reft^ bathing, unQ;ions,'_ 
the ufe of fine linen, &c. 

No eruption but that the prodiK^i: of which is 
contagious ought to be confidered as the itch.' 
When this difeafe has continued a long time, it 
leaves in the fidn a difpofition for producing, at 
certain periods, and often for feveral years, a hevr 
eruption, which is not contagious, and which 
ought not to be confidered as pforic. _ In the puf^ 
tales of the itch there is often found an animal- 
culum (acarus fcab'iei)^ which has been differently 
defcribed by naturalilis, and to which are afcribed 
the produdlion and propagation of the difeafe ; 
but this aflertion has never been properly proved. 

Tinea is cured by a pitch-plafter, in the form 
of a cap, which tearing up the whole fcabby 
flratum forms a new wound, the cicatrizing of 
which is then fpontaneoufly effedted. This dif- 
eafe would, in all probability, yield to a lefs vio- 
lent remedy. 



Herpes, which ha^ To great a fimllarity to ti- 
nea, yields ortl}'- to analogous rheans. 

In a word,' the cafe 'is the fame with all old 
ulcers, which are continued by the force of habit, 
and whofe hard and oallous- edges' oppofe cicatrl-' 
zation. When transforrried-into a recent wound 
they often heal very fpeedily. 

An afFe^lion of the ikin may fuddenly difap- 
pear, when a ftronger derangement takes place 
in another organ. In thefe cafes, the vulgar be- 
lieve, that the difeafc of the Ikin has been driven 
inwards, and that it has proceeded to the, part 
newly affedled ; but this difappearance bught'to be 
confidered merely as the confequence of the fti-ong 
a6lion of an organ which fufpends a {lighter in 
another part. When the eruption is recalled, an 
efFe(5l analogous to that of a veficatory is ob- 

Animals in the favage ftatfe do hot feem to be 
fubjecSl to any difeafes of the fkin ; but among 
thofe which we fubdue, and confine together in 
clofe, damp, and gloomy places, -or which re- 
ceive an infufficient quantity of food, or aliment 
of a bad quality, cutaneous aife6lions of a very 
noxious charadler foon manifeft themfelves. 

197. The glands of the lymphatic fyftem, the 
other glandular organs, and ' the white fibrous 



tiflues, are fufceptible of a peculiar phlegmafia, 
the progrefs of which is, in general, very flow. 

When a gland is irritated, either diredllj by 
the contadt of a foreign body, or indiret^ly by 
the adlion of another part upon it, the gland tu- 
mefies, and gradually becomes indurated. At 
firfl, a fmall round indolent body is felt, which 
progreffively increafes ; others arife around it ; and 
the tumour otlen becomes very large, hard, and 
unequal ; it remains a long time moveable, and 
produces no other inconvenience than that which 
refults from its weight and its polition : but at 
length it forms adhcfion with the neighbouring 

The cellular tifTue^ which furrounds the gland, 
often enters into adion, and exhibits the whole 
,feries of the phaenomena of phlegmon. Some- 
times, during this operation, the glandular affec- 
tion ceafes. When it perfifts, it continues its pro- 
grefs as if the phlegmon had not taken place. 

By opening the bodies at different periods 
of glandular tumours, it has been found that 
they have acquired the confiftence of concrete al- 
bumen j of lard more or lefs hardened j or of a 
cartilage, in the midft of which a few offified 
points are fometimes obferved. 

Scrophula is an atfe61ion of this kind, which 
{eems to arife from a certain ftate of weaknefs, a 



peculiar conflitution, for the moft part heredi-* 
tary : its lymptoms feem to fhow themfelves more 
readily on thofe organs lead fufceptible of re- 
adtion, and which may be faid to be endowed 
with lefs vitality. 

A fcrophuIoLis conflitution is announced by a 
delicate white fkin, flabby fulinefs of the fiefhs 
blue and often watery eyes, bufliy chefnut-co* 
loured hair^ the alae of the lips and nofe thicks 
the lower jaw broad, a particular acutenefs and 
delicacy of the fenfes, and often a premature in- 

This conflitution appears chiefly in large ilU 
built cities, damp, and looking towards the 
north. Among children it feetns to be the refult 
©f an excefs of nourifhment with want of exercife. 

When this peculiar -difpofition exifi:s, a point 
of irritation is foon obferved to be developed in 
Ibme of the glands ; thofe, for the moft part, of 
the neck and . mefentery in children; thofe of 
the lungs in adults, and fometimes in feveral of 
the articulations. In all thefe cafes, the irritation 
determines the ferics of phsenomena peculiar to 
the glands, and to the white organs. 

A fcrophulous conflitution, when it begins to 
manifefi itfelf, may. be eafily changed by the ufeof 
different ftimulants, wholefome nourifliment, ex- 
crcife, and good air ; bitters, tonics, Sec. frequently 

VOL. Ill, i Scrophalous 


Scropbalous fymptoms often difappear in con- 
fequence of fome acnte difeafe^ fmall-pox, he. 
They frequently difappear at the age of puberty, 
when the vital force aifumes a new a6lion and a 
greater degree of energy : if they perlill after this 
period, they generally continue for life. 

Rachitifm is a peculiar flate of the conftitution, 
which feems to have the greateft analogy and often 
to be confounded with fcrophula. It, however, 
differs from it in this refpedl, that it affeds in a 
more eflential manner the f)'ftem of the bones. 
In this difcafe the bones become foft and fwelled, 
and the motion and weight of the body bend them, 
and often produce the mofi: frightful deformity. 

This difeafe yields fometimes to the ufe of the 
general means indicated for fcrophula. The 
fle6lion of the bones even may be corredled, when 
not very great, by the continuance of any adlion 
that tends to ftraighten them, 

198. Syphilis in its hiftory flill prefents a great 
number of obfcurities. To have a clear idea of 
them, it will firft be proper to take into confidera- 
tion the primitive chancre. We fhall, therefore, 
fuppofe that an ulcer in the genitals may have af- 
fumed, by a concurrence of very extraordinary cir- 
cumftances, fuch a character, that the product of 
its fecretion, depofited afterwards on a part defti- 
lute of epidermis, in another individual, gives rife 

• to 


to the formation of a limilar ulcer, and that this 
kind of'ulcer may then be propagated indefinitely 
by the means of contact. 

An ulcer, in confequence of its being conta- 
gious, muft be perpetuated in the individual in 
whom it exifts, producing that ravage which is pe- 
culiar to it, and mull occaiion, in the whole of the 
nervous f)'ftem, a particular change of its ftate. 

In lyphilisthis change is fuch, that it gives rife to 
fubfequent accidents, which appear more readily in 
fome of the mucous membranes, in the lympha- 
tic fyllem, and in that of the bones. 

In fyphilis, therefore, we ought to confider: 

ift. The primitive chancre, whatever be its 
form, which varies according to the place where it 

2d. The peculiar a6lion of the nervous lyftem 
which it maintains. 

3d. The confecutive fymptoms produced by 
this adtion. 

The primitive chancre may be eafily cured at its 
commencement, by all thofe means which are ca- 
pable of changing the nature of an ulcer. Thus, 
profound cauterization of a recent chancre is fuffi- 
cient to deftroy it. When of long (landing, mer- 
curials, violent fudorifics, draffic purgatives, the 
ufe of fome mineral acids, of fome alkalies, and in 
general of all thofe means capable of producing 

1 % and 

llQ Reflections on the 

and maintaining a great change in the fyllem, 
caufe a termination of this morbific affection. 

But fyphih's which has not been checked in its 
progrefs often produces fiibfequent accidents ex- 
ceedingly troublefome ; fucb as confecutive chan- 
cres in different diftant parts, buboes, perioftofis, 
exoftofiSj debility, with pains in the limbs, caries, 
general atrophia, and a fort of confumption which 
may become fatal. 

It is probable that the product of the primitive 
chancre canalone propagate the contagion. In 
the different ftates of lyphilis all the means capa- 
ble of exciting in the fyikem a f^rong and con- 
tinued adion, during a period proportioned to the 
time the difeafe has exifted, always cure the pri- 
mitive chancre, and deflroy the fpecific a6lion 
which maintained it ; but the fubfequent acci- 
dents can be cured only by purfuing a courfe pe- 
culiar to them, and as if they had been produced 
by fome other caufe, Thefe accidents often per- 
liff, becaufe improper regimen and remedies main- 
tain the patient in a flate of debility which does 
not allov? the organization to make the effort ne- 
ceffary for effecting a cure ; and they frequently 
ceafe when all treatment is abandoned, and when 
a regimen proper for reftoring the ftrength is ob- 

This fimple explanation of the common pro- 



grefs of ij'philis is fufiicient to account for ali the 
forms it affiimes, for the nature of the accidents it 
produces, and for the caufe of the fuccefs or failure 
of all the means employed to counteradl it. 

A great number of chronic afFe^lions, which 
, take place at a longer or fhorter period after the 
appearance of fyphilis, are frequently confidered as 
maintained by this difeafe, and confequenlly are 
treated with mercurials. For the moft part they 
do not yield to this improper treatment ; but even 
when a cure is effedied it is ridiculous to conclude 
that the malady was of a ()'philitic nature. Mer- 
curials produce their efFe6l on the organization by 
exciting an energetic mode of aftion, which may 
be ufeful in a great many difeafes. 

199, Syphilitic blennorrhagia (gonorrhoea) feems 
to have the fame origin as fyphilis : it however 
exhibits acharader fo diftindt that it may be con- 
iidered as an afFeftion of a peculiar kind. It con- 
fiflsof a catarrh of the urethral membrane, or of 
the vulvo-uterine conduit. The product of this 
catarrh is contagious, and when applied to the ge- 
nital parts of another individual produces the fame 

This blennorrhagia, after continuing about a 
month or two, fpontaneoufly ceafes; or, if it con- 
tinues longer, the fecretion gradually lofes its con- 
I 3 . tagious 


fagious property, and the difeafe is changed into a 
fimple chronic catarrh. 

In feme women, however, blennorrhagiae of a 
long Handing become, under certain circumftances, 
contagions in the a6l of coition. 

Syphilitic blennorrhagia, in general, ceafesfpon- 
taneoufly at the end of a limited period ; but it 
may be cured much more fpeedily by ftimulating 
injeftions, which change the contagious nature of 
the fecretion. 

Syphilitic blennorrhagia, like all catarrhs, pro- 
duces a general derangement, which, after the 
commencement, is often exceedingly violent. It 
fometimes gives rife to derangements, which take 
place chiefly in parts having a very intimate rela- 
tion with the organ afFecled, fuch as the glands of 
the groin and the tefticles. 

When gonorrhoea is fucceeded by a fwelling 
of the tefticles, this new afFedlion is fometimes fo 
flrong that the running is immediately fufpended. 
In this cafe it may be proper to renew the fecre- 
tion of the urethra, which is always free from 
danger, in order to remove the difeafe of the tefti- 
cle, which, is much more fevere • but it is entirely 
ufelefs to endeavour to revive for this purpofe a 
fyphilitic blennorrhagia: the fame refult may be 
obtained from a fimple catarrh excited by any 
irritating injection. 


It is highly probable, that the fecretion of a 
chancre applied to the membrane of the urethra, 
or of the vulvo-uterine conduit, may fometimes 
produce a fyphilitic blennorrhagia ; but it is not 
probable that the produ6l of a gonorrhcea can occa- 
lion a chaacre. 

200. The tiflue of the lymphatic glands, and that 
of the glands appropriated for fpecial fecretioiis ; 
the tiffue of the white fibrous organs ; that of the 
bones, and even the fkin, in confequence of any 
irritation, are fufceptible of experiencing a fort 
of phlegmafia, the progrefs of which is generally 
very flow, and the refult always uniform. 

This chronic afFcftion of the glandular or white 
fibrous tifilies manifefis itfelf, for the moft part, 
after an acute phlegmafia of the other cellular, mu- 
cous or ferous tiffiies by which they are furrounded. 
Sometimes it is produced dire<5lly by any irritation 
whatever. In all thefe cafes, there firfi: appears a 
hard, indolent tumour, which increafes very fiowly, 
and at the commencement produces no other in- 
convenience than that which naturally refults from 
its pofition and its fize, and from the derangement 
in the fundtion peculiar to the part afFeded. 

Thefe tumours, when examined at diff^erent 
periods of their formation, exhibit a homogeneous 
fubftance, the confidence of which has a refem- 
blance to that of concrete albumen, indurated 

I 4 lard^ 


lard, or a cartilage more or lefs compact, in the 
midft of which there are fometimes developed a 
few offified points*, or in which are found fome 
cretaceous matters ; and on this account thefe 
tumours have been dillinguifhed by the name of 
fcirrhiis. Of this kind are thofe tumours formed 
in the glands of the breafl, after external laefion ; 
thofe which take place in the lymphatic glands 
of various parts, in the cafe offcrophula; thofe 
fmall tumours which are obferved in different 
points of the fubftance of the lungs, in phthificky 
perfons ; the fwellings which arife in the oefopha- 
gian and pyloric orifices of the llomach ; in the 
uterus, the ovaria, the proftate gland, at the 
neck of the bladder, in the reftum ; the tume- 
fa£tions of the white tifTues which furround the 
articulations; the different exof^ofes with a foft- 
ening of the bones ; the tumours in the cellular 
tifTue, after phlegmons which are faid to termi- 
iiate by induration ; and, in the lall? place, thofe 
tuberculous pullules which arife on the fkin, and 
chiefly on the lips, the als of the nofe, &c. 

All thefe affedlions, which appear to be fo differ- 
ent, and which feem to have no relation with each 
other, are however of the fame order ; they fol- 
low the fame progrefs, and exhibit the fame mode 

* An analogous ftate, but without increafe of fize, takes 
place in almoft all the fpft parts expofed to long-continued 
conipreirion or fr'iftion. Old age alfo frequently brings on 3 
fiRiilaj: ftate in the tiffue of the arteries, tendons, 3fc. 



of termination. Notwithftanding the varied f)'m- 
ptoms which neceflarily refult from the peculiar 
ilru6ture and numeroas ufes of the injured parts, 
the fcirrhous afFedion feems to bring them all 
back, to the fame ftate, by giving them the con- 
fiftence of concrete albumen. 

Thefe different tumours, when they attain to 
the fcirrhous ftate, may remain feveral years with- 
out making any progrefs, without increafi ng in 
fize, and even without producing much inconve' 

Sometimes, after remaining for a very long pe- 
riod in a. Itate of repofc, they may again ac- 
quire a progreffive ftate, if excited by any new 

Thefe tumours fometimes difappear when re- 
cent and not voluminous, in individuals of a 
ftrong conflitution ; but when they have once at- 
tained to a certain fize, when of lon^ Handing, 
and if the perfons be debilitated, they are no 
longer fufceptible of a fpontaneous cure. 

In this cafe, the other parts of the famp 
fyftem of organs, or of an analogous fyflem, con^ 
traft a great difpofition to a fimilar mode of af- 
fedlion, which eftablifhes a peculiar conflitution 
or diathelis. Thus the fcirrhus of the glands of 
one of the breafis, when of long flan ding, is 
generally accompanied with that of the neigh- 
feouring lymphatic glands, and with fcirrhus of 



the oppofite breafl ; and when the tumour has 
made a conliderable progrefs, the whole glandular 
fyftem is in general affected. 

The medical art can furnifh no other means of 
checking the progrefs of this evil, but extirpa- 
tion of the tumour when practicable, and the dif- 
ferent perturbing modes of excitement, capable 
of changing the fcirrhous conditution, when not 
too inveterate^ and when its effeds have not been 
far extended. 

The pretended diffolvents are fcarcely ever of 
any life ; and cauftics, fur the mo ft part, are 

When the fcirrhous tumour has attained to a 
certain degree of in creafe, it frequently happens 
that a nev\f mode of a61ion is excited, in confe- 
quence of a blow, the application of a caufticj of 
a phlegmon which takes place in the neighbour- 
ing parts of the tumour, and of any other irri- 
tating caufe. This hard homogeneous and indo- 
lent mafs, which feemed to have loft its whole 
organic ftructure, acquires then great fenftbility, 
and experiences a feries of very remarkable phae- 
nomena. There firft comes on a flight titilla- 
tion, with a troublefome itching, followed by 
more acute pains, which return by paroxyfms ; 
in a little time the heat of the part increafes ; the 
tumour becomes more voluminous and unequal ; 
the fkin alTumes a reddiih brown tint, and at 



length there is formed an accumulation of pus, 
fometimes thick, but for the mofl part of a recl- 
difli fluid, which is difcharged by the burfling of 
the fkin. Soon after the fecretion, when it comes 
into conta6l with the atmofpheric air, changes its 
nature, and there are then evidently obferved all 
the phaenomena of real putrefii6lion, which the 
vveaknefs of the part does not permit to be fuf- 
pended, but which is modified by a remainder of 

The j)ains, however, increafe with the fize of 
the tumour ;. the ulcer is enlarged, exhibits an 
unequal furface of a livid brown colour, and its 
edges become hard, proje61ing, and inverted, &c. 
The fkin which circumfcribes the tumour is of a 
violet colour, and covered with varicofe veins. 

In the courfe of the difeafe, the cancer flowly 
deflroys all the parts which it afFedis, and even 
the bones ; the deftru6lion of the venous tiflue 
produces frequent haemorrhagies. When the can- 
cer fpreads to the neighbouring parts, the one pri- 
mitively afFed:ed exhibits fometimes an ugly fear, 
rough and deprefled. 

It may be readily conceived that an affection fb 
terrible, accompanied, for the mofi: part, with 
excruciating pains, cannot long continue without 
producing diforder in all the other fundions ; 
they indeed all become deranged in fucceflion, 



and the patient, at lengtb, falls into a llatc of 
confumption, which terminates in death. 

The animals, which we render fubfervient to 
our wants, are not exempted from afFe6lions of 
this kind ; but they are more rarely attacked by 
them, as they are better calculated to refift thofe 
caufes by which they are produced. 

20I. The bones arc fufceptible of phlfgmafls, 
as well as the foft parts ; but in the bones their 
progrefs is much flower. 

In fra6lures, as well as in wounds, the broken 
extremities grow foft, fwell, become painful, and fe- 
crete at firfl a bloody and ferous matter, and then 
a thick gelatinous fluid, which forms an incrufla- 
tion on the fradlured ends. This fluid, in ex- 
uding from the two feparated furfaces, is con- 
founded with them, and forms a cartilaginous 
fubflance which produces a ring, always apparent 
in the place of the fra6lure, and which Alls up 
the cavity of the long bones. This cartilagi- 
nous fubflance then pafles to the ofleous ftate, 
according to the habitual mode of the develop- 
ment of the bones ; and thus produces a confo- 
lidation of the fracture. 

Fractures, as well as wounds, are confolidated 
more fpeedily, according as the feparated furfaces 
are more carefully preferved in a fl:ate of reft in 



their rerpe(?live fituatlons, and as the individuals 
enjoy a better ftate of hcalrh. 

The time neceflary for the formation of the 
callus varies from a fortnight to feveral months, 
according to the nature of the fradlure, the age 
and difpofition of the individual, &c.; but the 
mean term is from thirty to forty days. In fome 
difeafed or highly debilitated perfons, the confo- 
lidation of fradurcs may not take place; it may 
alfo be prevented or retarded when any powerful 
aSion, maintained on the organ, fufpends the 
procefs of offiScation, 

When the fradured parts have remained fepa- 
rated for a long time, they both become in- 
cruiled with a cartilaginous fubftance, which 
acquires an ofleous nature ; and Ihe two ends, re- 
tained by an intermediate ligamentous fubftance, 
form a fort of articulation. In this ftate the 
fra6iure cannot he confolidated but by excifion 
of the ends of the bone. 

When a bone has received a violent contufion, 
or when it remains fome time expofed to the air, 
it becomes dead in a greater or lefs extent of its 
furface and depth ; a vafcular apparatus under the 
form of granulated and carneous puftules is deve- 
loped at the furface of the found bone ; the dead 
part gradually detaches itfelf, and at length is 
completely feparated at the end of a certain time, 



the duration of which in general is In propof- 
tion to the thicknefs of the part which has ex- 

Thofe fubftances, to Vv'hich the property of 
haftening the exfoliation of a bone has been 
afcribed, are fcarcely of any utility. 

When the bone of a limb is mortified through- 
out its whole extent, the circulation between the 
perioflenm and the medullary reticulation is in- 
terrupted ; the bone, become a foreign body, 
produces feveral phlegmons in the neighbouring 
cellular tiffue : thefe tumours fuppurate, and 
remain fiftulous. The phofphaie of lime, which 
can no longer diftribute itfelf in a uniform man- 
ner at the furface of this bone, difFufes itfelf irre- 
gularly around it ; gradually afFumes its place, and 
produces a new fhapelefs bone, in the middle of 
which the old one is inclofed. This dead bone 
occafions by its prefence, in the middle of the 
new ofleous produdlion, pains which are often 
excruciating, and which render the extra6lion of 
it neceflary when poffible. During the whole 
courfe of the difeafe, the mortified part produces 
and always maintains fiftulous ulcers, even through 
the new bone, which is thus perforated with feveral 

This mortification may be produced artificially 
in an animal, by making an aperture in a long 



bone, in confequencc of which the liru^iure of 
the medullary reticulation may be altered. (See 
Les Experiences de Troja.) 

When the mode of a61ion of the vafcular tilTue 
of a bone has been changed by any caufe what- 
ever, this organ may become altered and fwelled 5 
in which cafe the fecretion of the phofphate of 
lime is increafed or diminifned. 

Thus the violent contufion of a bone; the pre- 
fence of fome phlegmons or chronic ulcers in the 
neighbourhood ; the general a<5lion maintained 
by lyphilitic, fcrophulous, fcorbutic, and cancerous 
afFedions, and all difeafes which, by their long 
duration, have greatly exhaufted the vital forces, 
may produce a change in the natural a6lion of 
the vafcular tifTue of one or more bones. 

Sometimes the fecretion of the phofphate of 
lime is diminiflied ; the bone bends, and is eafily 
broken : at other times its vafcular tifTue is gra- 
dually weakened or deftroyed ; in which cafe 
the folid part of the bone becomes brittle and 

In fome cafes, the bone fwells, and the fecre- 
tion of the phofphate of lime increafes to fuch a 
degree, that the accumulation of it may give to 
the bone the confidence of ivory. 

This eburneous exoftolis may produce no other 
inconvenience than that which refults from its 
iize and pofition. 



In other circumftanceSj the vafcular part fwellsj 
and is fometimes conliderably puffed up ; the fe- 
cretion of the calcareous fait decreafes, and the 
bone gradually lofes its confiftence, and affumes 
that of cartilage. At other times, ^e vafcular 
tiflue, by increafing in volume, feparates and dif- 
tends'the laminae of the bones ; and the refult is 
a large carniform mafs, which fupports in part 
a light cavernous Skeleton formed by the oiTe- 
ous fragments and afperities. 

Sometimes the fwelling of the bone takes place 
very fpeedily, with rednefs, heat, acute pains in 
the part, and febrile fymptoms. At other times 
it is produced flowly and with very little inconve- 
nience. The difeafe may fufpend its progrefs 
even for a very long time, fuch as feveral years, 
and afterwards refume it. 

When the ofleous tiifue has attained to a cer- 
tain ftate of weaknefs, with a peculiar mode of ac- 
tion, whether the bone be in the neighbourhood 
of chronic phlegmons or ulcers, or only in contact 
with the atmofpheric air ; or, whether it has in- 
creafed in (izie, efpecially by afluming a cartila- 
ginous confidence, this ofleous tiffue may acquire 
an a6lion analogous to that acquired by the foft 
parts, during the phaenomena of gangrene or ul- 
cerated cancer ; and may produce ichorous or 
fanious pus, which will effe6l a folution or de- 
compofition of tke ofleous organ. 

^ • Carhi 


Caries makes a more rapid progrefs when it 
affects the fpongy bones, and when it takes 
place in contadl with the atmofpheric air. It is 
the more difficult to be checked as the indivi- 
dtJlal is more debilitated. 

The progrefs of caries may fometimes be 
checked by complete excifion of the difeafed part, 
or by cauterization ; and by all thofe means ca- 
pable of reftoring ftrength and energy. 

In all difeafes of the bones it mud always be 
remembered, that it is the vafcular tifTue alone 
which exhibits the phenomena oi difeafe, fince it 
alone is the living organ, and becaufe the alter- 
ations which take place in the fecretion of the 
phofphate of lime are merely the refult of the 
mode of afFedion of that tilTue of vellels. 

Draught animals, whofe mufcular exertion we 
continually employ, are expofed to violent efforts 
which may often give rife to difeafes in their 
oflfeous parts ; and we indeed find among them all 
thofe modes of alteration of which that fyftem 
of organs is fufceptible. 

202. From this curfory view of the numerous 
phlegmafiaD to which the different parts of the 
organization are fubjedl, feveral important truths 
may be deduced. 

They are all produced by an impreffion made 
diredly or indiredlly on the organ afFe<Sed, by an 

'VOL. m. K irritating 

laO kEFLEdTio^^s OJr the: 

irritating: caufe, which altering, more or lefs^ itg 
organic ftru61ure, gives rife to a change in its 
mode of adtion. 

Robuft men and animals refift the greater part 
of the caufes of phlegmafise ; and thofe which in 
fuch men and animals refult from violent external 
Isfion are aKvays Ipeedily cnred. 

An organ yields more eafily to the I'mpref- 
lion of pblegmalic caufes, according as it is 
weaker, and as it has oftencr experienced their 

Phlegmatic affections are the more troubleforae, 
and the more difficult to be healed, the older they 
are, and the weaker the conftitution of the indi- 
viduals attacked by them. 

All thefe afFe61ionSi in the fucceffion of their 
phaenomena, exhibit a flower or more rapid pro- 
grefs. Almoil all the anatomical. fyftems of or- 
gans are fufceptible of thefe two modes of a6tion^ 
which reftore health, or bring on death by a feries 
of condant phcsnomena. 

The organs affedled by phlegmada experience 
derangements, Vv'hich are particularly remarkable 
in the exercife of the funclions peculiar to them. 
Thus the iecretory organs experience changes in 
the mode of their fecretion. The new produdf:, 
which is evidently the rcfult of the difeafe, has 
bcea conlidered as the caufe of it, and has given 
rife to the theory q{ hmnours. 



th fome cafes, the produ6l of the morbific f6- 
cretion, applied to a fimilar organic part of. an- 
other individual, produces the fame afFeciionj which 
is thus propagated by the way of contadl. 

The greater part of the phlegmafise may be 
checked at their cOmfflcncement, and often fuf- 
pended in their pfogrefs : Ibme teduce the art to 
mere expe^latiOn. 

A violent phlegitiaiic afFctftion feiTiOves, in ge- 
neral, one that is lefs fo. 

The alternation which often fpon t an eoufly takes 
place between phlegmaliEE of different degrees of 
ftrength in different organs, has induced fome to 
believe in a tranfpoi'tation of hurnours, and given 
rife to the theory of metajiajis. 

The principal means, employed with advantage 
in thefe difcafes, tend either to excite irritation in 
a part different, from that which is afFe6ied, or to 
change the mode of action which conftitutes the 
difeafe, or to remove the produces of the fecretion, 
the prefence of which may maintain the derange- 
ment and produce further accidents. 

In acute phlegmafia it is, for the moft part, pro- 
per to diminifh the general or local powers, while 
it is almoft always neceHary to maintain or to in- 
creafe them in thofe which are chronic. 

Acute phlegmafiss foon difappear, produce deaths 
or are converted into chronic. The latter almoft 

K a always 


always lead flowly to a ftate of confumption, which 
at length proves fatal. 

Acute phlegmafiae difappear by a feriesof phse- 
nomena, which fucceed each other regularly in the 
fame order. Art, in general, ought to refpedl this 
progrefs ; and its only obje<5l fhould be to remove 
every thing that might derange it. In many cafes, 
however, and particularly in men of a robuft con- 
ftitution, thefe difeafes may be checked at their 
commencement, or even fufpended in their pro- 
grefs, without any danger. 

Art, therefore, may check fome of the phleg- 
mafiae, and favour the progrefs of the greater part 
of them ; but it cannot cure any of them. 

Acute phlegmafice bring on death, in confe- 
quence of the derangement which the local affec- 
tion produces in all the functions, and the patient 
dies by the confecutive efFe6l of the febrile fym- 
ptoms. An acute phlegmafia produces, with more 
efficacy, a general derangement of the fun6lions 
or fever, according as the conftitution of the pa- 
tient is weaker, or more irritable. 

In the acute afFc^lion, the part may be fo far 
debilitated and enervated as to prefent only a weak 
refiflance to the laws of chemical affinity: it then 
exhibits, in the rapid phaenomena of gangrene, a 
real putrefadlion modified by a remainder of vi- 



The chronic afFe(9:ion may maintain in the mu- 
cous membranes, or in the cellular tifTue, a more 
abundant morbific fecretion, which continually 
weakens the individual. Befides, the injured part 
deranges the funAions of the fyftesn to which it 
belongs ; the diforder fpreads from one funtlion 
to another, and the patient is carried gradually 
to a ftate of confumption, which terminates in 
death. In other fyftems of organs, and particu- 
larly the glands, the white fibrous tifTues, thefkin, 
and even the bones, it happens, in confequence of 
a flow and gradual alteration, that the part fwells, 
becomes indurated, and aflumes the confiflence of 
concrete albumen or of cartilage. 

Chronic phlegmafia often remains in this flate 
without producing much inconvenience; but if it 
again enters into a61ion, it exhibits a termination 
analogous to that of acute phlegmafia : the debili- 
tated part prefents only a weak refi fiance to the 
chemical action ; and, in the flate of cancer and 
caries, experiences all the phsenomena of a very 
flow putrefaction, 

203. It has been feen that acute phlegmafise 
often produce by their acutenefs a general derange- 
ment in the order of the fundions. But there are 
fome other phlegmafiae which, inflead of being the 
caufe of this derangement, feem to be the efFcd 

K 3 of 


of it : of this kind are eryfipelas, fcarlatina, rube* 
ola, and vanoiae. 

In thefe diJeafes fyniptoins are developed which 
announce thp general derangement of the nervous 
adion ; fuch as pain in the heid, debility of the 
fenfes, proftration ortlrength, lofs of appetite^ ac- 
celerated circulation, derangement in the fecre- 
tions^ at length fever \ and towards the fourth 
day there comes on a ci^taneoias phlcgmafiaj ge- 
Dpral or partial. 

In variolous fever, th^ iluid contained in the 
mature puftule^, either frefh or dried, becomes a 
liimulant proper for producing the fame fever in 
another individual, when applied, though in the 
fmallcft quantity imagipable, to a part defiitut^ of 

As this pus, for tlie mofl: part, is fecreted in 
abundance from the whole furface of the body of 
each patient • as it is of fuch a nature that it may 
be kept a long time in a llate of deficcation, on the 
fpales of the puftules, without loiing its fpeqific vir- 
tue; and as it may be reduced to very fine powder, 
fo as to be tranfported to a difiance by the winds, 
and introduced into the aerian paflages; it may be 
readily conceived that this difeafe, when once dc* 
¥eloped by accidental circumftanccs, mufl be after^ 
wards propagated without interruption. 

It is therefore the action produced by tl^e pon« 



tacl of this fubftance on the nerves of the touched 
part, which occalions in the whole fyflem that fe- 
ries of general phasnomcna which conftltuie va- 
riolas, and not the abforption of it, and its being 
conveyed into the general mafs of the blood, as is 
commonly fuppofed, 

The moil fingular phaenomenon obferved in this 
difeafe is, that, when the individual has once exhi- 
bited the feries of phsenomena which it produces, 
the organization lofes its fitncfs for being again af- 
fedeU by the variolous flimulant. We are entirely 
ignorant in regard to this peculiarity, and to the 
nature of the change which has been effected in 
the fyftem, 

But, fince the organization is fufceptible of 
lofing its difpofition for being afFefted by the virus 
of variolas^ it may be readily conceived that other 
qaufes than the difeafe may produce the fame ef- 
feft; and this caufe has fortunately been difco- 
vered in the virus of the vaccina. 

Thefe plain obfervations are fufficient to fhow 
the folly and abfurdity of the objeftions which have 
been made againfl employing the vaccine inocula- 
tion as a prefervative from the fmall-pox. The 
fear of a poifon introduced into the blood, capable 
of producing future derangements, can be enter^^- 
tained only by perfons entirely unacquainted witl:| 
fne laws of the organization. 

yhe fmall-pox, communicated to nuiTtcrous 
K 4 tribes 



tribes of people, has often occafioned the moft 
dreadful ravage, by fweeping off a part of the in- 
habitants, or by rendering them maimed and de- 

The caufes which have chiefly contributed to 
increafe its ravage are thofe proper for favouring 
the eruption : thefe depend on local circumflances, 
poverty, ignorance, and prejudice. 

As the fmall-pox confifts eflentially in that fever 
by which it is charafterized, it is highly defirable 
that the eruption, vi/hich is merely a confecutive 
accident, thould be as little confluent as poffible. 
Some phyficians are even of opinion that an indi- 
vidual may have the variolous fever vi^ithout erup« 
lion, and be no lefs fecure from a relapfe : it is 
poffible that fome of thofe who believe that they 
never experienced this difeafe, may have had the 
fever without any eruption. But the vulgar ima- 
gine there can be no fmall-^pox without pullules : 
they believe that every thing which comes out 
was formed in the body, and that the more con- 
fluent the eruption, the more certain the cure. 
This popular error, which on the whole is very 
pardonaUe, has been the caufe of the great ra- 
vage of the fmall-pox ; becaufe all the means of 
cure have been applied in fuch a manner as to 
favour the quantity of the eruption, while the 
9bje&. iliould have been to diminifh it. 

g A more 


A more rational mode of treatment, among 
enlightened nations, has very much leflened the 
ravages of this difeafe ; the pradice of inocula- 
tion has alfo contributed to render it milder ; and 
it is poffible that the vaccine inoculation may 
extirpate it entirely ^ but it never will produce 
this efFedl unlefs the practice be enforced by a 
law, fo as to oblige parents to have their children 
inoculated within a certain period after they are 
born. Such a regulation, which would tend to 
prevent the twentieth part of mankind from being 
fwept off at an early period of life, or from being 
maimed and deformed, would be of the utmoft 
importance to fociety. 

204. In phlegmafiss, and particularly thole, 
which are acute, the local alteration often prOr 
duces the general derangement of the fun61ions 
which conftitutes fever, and the caufe of this 
afFedlion is then evident. But it frequently 
happens that the impreliion, made on an organ 
by any caufe whatever, produces the general 
derangement of the fun6tions or fever, without 
leaving any traces of local alteration ; which has 
rendered the etiology of this difeafe very obfcure. 

Fever confifts in a derangement, more or lefs 
complete, of the different fun61:ions, with a feries 
of phsenomena which tend to bring back to 
health. This a|Fe6liorj may be produced by a 



great variety of caufcs ; thus, the too long contU 
nued imprefTion of heat, of dry or damp cold ; 
iTfarfliy exhalations, and all thofe which proceed 
from vegetable and animal fubftances iii a ftatc of 
putrefadlion ; violent and forced cxercife, a tranf- 
port of paffion ; derangement in the gaftric organ 
by excefs or privation of food^ &c. may occafion 

In this difeafe, each fanclion is deranged in a 
manner peculiar to itfelf, as may be proved by a 
careful examination. We indeed obferve : con- 
fufion^ exalted fenfibility or vt'eaknefs of the 
fcnfes ; pain in the head ; proflration of the muf- 
cular ftrength, or fubfultus tendinum ; irregu- 
larity in the movements of refpiration and circu- 
lation i fhivering or great heat ; derangement of 
the fyfiiem of digeftion : hence lofs of appetite, 
thirfi^ mouth dry or clammy, &c. a new mode 
©f a(5lion in all the fecretory organs, but mofl ftn- 
fible in the fecretion of tvveat, urine, hc^ 

Though fever always confiils in a derangement 
of the different fun(51ions, accompanied with a 
feries of phasnomena which tend to bring every 
thing back to the natural order, it is evident that 
this derangement may vary in an indefinite man- 
ner, according to the caufes by which it is pro- 
duced, the conftitution or difpofition of the indi- 
vidual, and to the combinations pollible in the 
numerous tymptoms which conftitute the difeafe; 


.aiid hence have arifen the thoufand and one vari- 
eties of fever defcribed hy nof ilogifts- 

The moil ftriking difference e hibited by fever 
arifes from its progrefs, which may be either con<- 
tinued with remijfnns^ more or lefs fenfible ; or 
xeturn by paroxyfms with covn^Aeie intermijfwns : 
\yhich eftab'ifhes the natural divifion of this affec-*' 
tion into remittent and mter^uittmt. 

Remittent fever may be diflinguifhed alfb, ac- 
cording to thfr feverity of its i}mptoms, into_/»j- 
'ble remittent, which is never mortal of iifelf, 
taind jpern cious rem:te?it^ which Irequenily becomes 

205. Simple remittent exhibits an indefinite 
feries of tranfient fhades of little importance, 
and difficult to be defined. Among thefe fhades, 
however, it is poffible to eftablifh three difiindl 
forms, with which the different particular cafes 
are conneded in a more or lefs direcl manner. 

ift. In a young man of a fangaine and robuft 
conftitution, the fadden imprefl[ion of dry cold, 
violent and forced exercife, a firong tranfport of 
pafiion, ike. may produce a {Q,\'Qr, which is lud- 
denly announced by a flight fhivering, and in- 
creafes in a continued manner, with rednefs of the 
face and eyes ; beating of the carotid arteries ; 
llight pain in the head ; moift univerfal heat $ 



ample and frequent pulfe, &c, Thefe fymptoras 
gradualij increafe, and terminate at the end of 
the firft, fourth, ninth, or fourteenth day. Sy- 

ad. In adults of a llrong arid conftitution, a 
firm and irafcible charafter, with a predominance 
of bile, the fame caufes as in the preceding cafe, 
a derangiement of the gailric ij'fiem, or ftrong 
marfhy exhalations, may produce a fever, which 
after fome days' indifpoiition maiaifeils itfelf by a 
fudden attack ; violent pain in the head ; rednefs 
in the face, with a greenifh yellow tint around the 
noie and lips ; great fenlibility in the epigaftrium, 
auiea, vomiting; pulfe frequent and full; dry 
beat ; exceiTive thirll, &c. This fever terminates 
ipontaneoufly towards the end of the fecood qr 
third week. Bilious fever. 

3d. Men of a weak conftitution, but for the 
moll part females, and all perfons of a pale com- 
plexion, relaxed fibres, and a flow character, are 
differently afFedled. The fame caufes, as in the 
preceding cafe, produce in them a fever, which 
announces itfelf by a long feries of phenomena, 
and which commences its attack in a lefs fenlible 
manner. The lymptoms are : palenefs of the face^ 
flight pain in the head; fenfibility of the whole 
abdomen ; dry cough ; mucous excretions ; pulfe 
little accelerated ; nights more painful than the 

days ; 


days J flow progrefs of all the iymptoms ; infen- 
fible ten iVi nation towards the end of the third, 
fourth, or fifth week. Mucous fever. 

' Thefe three forts of fever, eftabliflied only by 
abftradion, and which nature rarely exhibits in 
that Hate of fimplicity, conftitute three principal 
kinds, which have diftind chara6lers, and to which 
may be eafily referred the numerous varieties of 
fimple remittent fever. All the varieties of this 
form of difeafe are fcarcely ever mortal, and are 
cured fpontaneoufly at the end of a limited time. 

Remittent fevers, like moil other afFe61ions, 
may be often prevented or checked at their com^ 
mencement ; but, in general, they ought to be 
refpedled in their progrefs, which feems to be the 
flow method employed by the organization to re- 
flore the deranged order of the functions. The 
medicines and powerful topics employed with (b 
much profufion during the progrefs of febrile 
iymptoms, are for the moft part very prejudicial. 

When a remittent fever has made its attack 
completely, it requires the expe61ant mode of treat- 
ment, and will not admit the application of any 
means but fuch as are proper for favouring its na- 
tural progrefs. 

Simple remittent fevers, which are not cured 
fpontaneoufly, are flowly changed into chronic 
afFe6iions, or afllime the pernicious remittent form, 
©f which we- are now about to fpeak. 

206. Men 


2,06. Men who inhabit a falubrious countf}'^ 
who take fufficient exercife, and who are properly 
lodged, clothed, and fed, are rarely attacked by 
fever. That which takes place, approaches more 
or lefs to one of the three ty[)€s we have indi- 
cated, according to the conilitution of the indivi- 
dual, the ftate of the atrnofphere, &c. ; and is 
never mortal. But in very po[Hilous cities, where 
amidft poverty on the one hand, and opulence 
on the other, a great many individuals are ener- 
vated by exceflive fatigue, want of food, or food 
of a bad quality, or by habitual idlenefs, and ex- 
cefs of too fucculent noiirifhrnent j when the per- 
Ibna debilitated by thefe caufe«, or in confequence 
of a conftitution naturally feeble, of melancholy 
mental aifedlions, &c. are attacked by a fimple 
remittent fever, it is not uncommon to fee it airuine 
the pernicious form» This form is charadlerized by 
a weakened f3:ate of the functions of the fenfes; 
proft ration of mufcular ftrength ; lofs of tone in 
all the titTues ; an air of intoxication and ftupor, 
delirium, &c. It generally terminates by the 
return of health, or by death at the end of the 
fecond, third, or fourth week. (Adynamic fever., 
Futrid fever.) 

This fever is attended fometimes with Sfreat de- 

rangement in the whole nervous action •, the func* 

tionsof the various fyftems of organs are fomelimea 

exalted, and fonjetimes almoft annihilated. All 

4. the 


the iymptoms of this difeafe exhibit anomalies and 
fudden changes. (Ataxic fever. Malignant fever.) 

Pernicious remittent, like limplc fevers, may 
be prevented on their approach, or checked after 
their attack, by all thofe means capable of produ- 
cing a fiirong fhockj or a powerful and continued 
diftradlion* But when their progrefs is once com* 
pletely eftablifhed, they ought to be refpedled. 
All the aflive remedies, fo often employed, are 
almoft always fatal : it will only be proper to 
maintain the flrength by fome varied or tonic fti- 
mulants, in order that the difeafe m<iy fpeedily 
arrive at its termination. 

The cauffe which mofl efFe(51ually contributes 
to produce remittent pernicious fever is the exha- 
lation of vegetable or animal matters in a llate of 
putrefadlion, efpecially in debilitated and ener- 
vated perfons, or perfons of a weak conltitution. 
When this caufe is very extenfive, and has exer- 
cifed its aciion on a great number of individuals, 
it renders the difeafe epidemic. \x\ this cafe, the 
iDJafmata difengnged from the furface, or from the 
interior part of the bodies of the fick, reduced to 
a ftate of extreme vveaknefs, become b. nev/ and 
very powerful caufe of propagation ; and the 
fever, which at fir ft was only epidemic, at length 
becomes contagious. ^ 

In countries where the population is very great, 
or where men are fubjeded to forced labour, by 



ignorance and defpotirm, and often under a 
fcorching atmofphere, or amidfl continual damp- 
nefs ; thefe beings, who have food of a bad qua- 
lity, or infufficient in quantity, without alkoho- 
lized beverage, who are badly clothed, and who 
refide in gloomy, damp, and confined huts, often 
in the neighbourhood of vegetable or animal fub- 
ftances in a flate of putrefa6lion, acquire a difpo- 
fition highly favourable for the development of 
this difeafe. It is obferved that it manifefts it- 
felf more particularly in confequence of this 
warVn, damp temperature, in which the body re- 
mains without ftrength and without energy. 

When it has given birth to a certain number 
of pernicious fevers, they are then rapidly multi- 
plied by the exhalations which proceed from thet. 
difeafed bodies. 

Thefe miafmata, when received into the lungs 
of the furrounding perfons, produce in them an 
attack of the fame difeafe, with the more facihty 
as they are more difpofed to receive it 3 and thus 
favour the progrefs of the contagion, which fpreads 
with alarming rapidity. 

In the courfe of this fever, the vital forces are 
weakened to fuch a degree that the body feems 
to refill only in an imperfe6l manner the laws of 
chemical affinity ; and it indeed fhows fome figns 
of decompolition differently modified by a rem- 
nant of vital adion. In this point of view, the 



plisenomena which take place in the whole organi- 
zation may be compared to thpfe which occur in 
a gangrened limb. 

Pernicious fever, though at all times efientially 
the fame, exhibits very diflindl charadters^ ac- 
cording to the climate where it takes place, the 
difpolition of the individuals whom it afFeds, the 
infalubrity of the countries, the feverity of the 
fymptoms, the greater or lefs rapidity of their pro- 
grefs, &c. which produces differences obferved in 
the different forms denoted under the names of 
the Jail or hofpital fever ^ yellow fever ^ and plague t. 
Thefe difeafes, efientially the fame, differ only 
by fymptoms of little importance, and by compa- 
rable degrees of intenfity. The hiftory of the 
different peflilential epidemiae, and a more exadt 
knowledge of the nature of this difeafe, fhow that 
the plague cannot develop itfelf fpontaneoufly, 
but in cities the wretched, ignorant and fuperfi:!- 
tious inhabitants of which are confined in damp, 
gloomy habitations, a prey to poverty and dirt j 
fuch iis the inhabitants of fome countries of Afia, 
Africa, and America. It may fhow itfelf, alfo, in 
any country after famine, in towns in a fta-ie of 
fiege, overcrowded hofpitals, occ. 

The chemical compofition of the miafmata ex- 
haled by pulmonary and cutaneous perfpiration, 
and by the other excretions of bodies affefted 

VOL. Hi. I. with 

140 REFLEeTlrONS: O^^- •J'jajEf ,; 

with this kind pf f^ver,4s -llill,;un.kno\vn j but,^iit, 
is not probable that thefe mialiData can commu- 
nicate the difeafe by their contaft with the fkin ; 
nor does it appear that they remain long fixed to 
articles which hayq been u fed by the infeded j 
on the contrary,, they ^^eenirltQ evaporate with, the 
greatefl facility. o 'bs^tb 

If the miafmata of the plague could eafily re- 
main attached to different articles, and be con- 
veyed from one place to another, which is far 
from being proved, it is probable that they might 
be expofed, without danger, among civilized peo- 
ple, who can procure by eafy labour the necef-. 
laries and comforts of life, gDoiB'H^ 

The fpontaneous development of the epidemiae 
of the jail fever, the yellow fever, and plague,, 
which have taken place at different period^, 
in .various eountrie.s of Europe, may. b^i. .mc)i:^,, 
ealjly con ceiv:ed than fbe tranfportation from di-, 
ftanjtj-egion^ of .^.fp^cific? virus capably of, produ- 
cing them. 

But there is no need of fuppofing this tranl^ 
portation, lince it is evident that the development 
of a pernicious fever has taken place under a va- 
riety -vQf.,circumflances. This fever may theu 
afTume a very high degree of intenfity, by fpreading 
itfelf to individuals weakened by every debilitating 
caufe. The miafmata which then arife, from thefe 
vx r ' ;, , , _y bodies^ 


bodies, enervated by wretchednefs and difeafe, 
exHibit a charadler highly contagious, and pro-' 
pagate the fever with great rapidity. '" '"' r 

When the plague begins then to ri^aKe^^f^pici' 
progrefs in countries where it does not frequently 
ofccur, a general confternation prevails ; and the 
dread of an evil, confidered as unavoidable and 
mortal, difpofes the body for receiving the conta- 
gion, and occafions more ravage than the dif- 

It refults from thefe confiderations, that the 
fureft and fpeedieft means of checking the con- 
tagion of an epidemic fever, which becomes in- 
fedlious by the lungs, is to remove the lick imme- 
diately from the city, and to place them under 
tents, where there is a free circulation of air, 
that the contagious exhalations may evaporate 
with more facility, and be prevented from infe(5t- 
ing thofe in the neighbourhood. Thefe confider- 
ations lead us alfo to fome refle(5iions on quaran- 
tine and lazarettoes. ^" 

Thefe eftablifhments and inftitutibn^ wefeYoVfn- 
ed at a period when there was juft reafon for 
being alarmed by a horrid difeafe, the caufe of 
which was unknown, and wtfjr* the progrefs of 
which phyficians were very little acquainted, in 
confequence of the imperfedt knowledge they 
had at that time acquired of the organization. It 
was therefore natural that people ihould fearch 

L 2 for 


for and employ fuch means as were thought pro- 
per for preventing a dlfeafe, which they believed 
muft necefTarily be brought from places where it 
frequently appeared, to others. where it v/as rarely 
found. But it is very probable that fuch pre- 
cautions are entirely ufelefs in regard to the ob- 
ject propofed ; and that they would be rendered 
fo by the manner in which they are employed, 
even if what is apprehended could take place : 
that is to fay, if the principles of the plague were 
capable of adhering to merchandife, and of being 
thus preferved for a long time in bales, in order 
to be afterwards communicated by contaS:. 

The government which, by exa(ft experiments, 
which at prefent may be eafily made, fhall clear 
up the qiieftion refpe61ing contagion, and by thefe 
means convince the raofl incredulous and moH 
timid, that no danger of this kind is to be appre- 
hended, will be freed from a very great reftraint, 
and may give new vigour to its commerce. 

207. Intermittent fever exhibits different types, 
according to the intervals by which the different 
paroxyfms are feparated. The paroxyfrns return 
periodically at the commencement of the fecond, 
third, or fourth day, and furnifli the quotidian, 
tertian, and quartan types. 

Phyficians have obferved, that tertian fever 
takes place under the fame circumiiances which 



produce bilious fever, and in individuals who are 
mofl fabjecl to it, and that quartan or quotidian 
f6Ve>' prefents a ftriking analogy with mucous 
fester '; but this relation does not render it necef- 
fery that internnittent fevers fhould be united 
with the remittent. 

Intermittent fevers Teem to be compofed of as 
many Ihort difeafes as there are paroxyfms. They 
may be checked at the commencement of each 
paroxyfm, and thus fufFer much better hold to 
be taken of them. It is in thefe fevers, therefore, 
that cinchona has been attended with the moll 
decided fuccefs.^ 

A paroxyfm of fever may be prevented, or im- 
peded, by all thofe means which are capable of 
profducing in the organization a new mode of 
energetic action, continued for fome time : fuch 
as a flrong dole of cinchona, opium, or wine, 
given during the remiffion, or a little time before 
the paroxyfm ; a very ftrong and acute dillrac- 
tion, Sec. 

During fummer, and in young perfons of a 
ftrong conllitution, thefe fevers difappear fponta- 
iieoufly after a fmall number of paroxyfms ; in 
perfons of a weak conflitution, and during the 
cold damp feafons, they are exceedingly obftinate. 
When thefe fevers continue for half a year or a 
year, they frequently induce chronic afFe61ions, 

L 5 which 


which flowly lead to a fiate of confumptipn that 
in the end becomes mortal. iiixforfi n pi • 

Intermittent fever has its pernicious form as 
well as the continued. Its pernicious character 
arifes from a peculiar and predominant fymptom, 
the continued exacerbation of which produces 
death at the end of the third, fourth, or fifth par- 
oxyfm. It is in this form of fever in particular, 
defcribed fo well by Torti, that it is proper to 
make an early ufe of cinchona, to prevent a par»- 
oxyfm which may become mortal. 

Pernicious intermittent fever, as well as perni- 
cious tertian and quartan, is epidemic, when in- 
duced by exhalations from marfhes dried up toO' 
fuddenly by the heat. The miafmata which arife 
from thefe muddy bottoms, received into the 
lungs with the atmofpheric air, produce on the 
nerves of that organ an impreffion which .gives 
rife to the ieries of febrile phaenomena. ? t^t -^d 

The aftion of th^fe miafmata is more powerful 
'6^ individuals not accuflomed to it, and who are 
^ifi a weak flate of health. :Ji£9iib 

'^ '^^Si' Anfinials ^fe fbfceptible ofl^experiencing 
that general derangement of the fimftions which 
conftitutes fever, with all that feries of fymptoms 
which tend to bring back health. The fever, com- 
monly renaittent or Qontinued, afTumes various 

HlSTt)I«ri QF! !j>ISE A S E S, ] 5 1 

forms accordi rig to their peculiar organization, 
^nd to a thoufand other accedory cireumftances. 
->: Among animals coll e(3;ed into herds or flocks, 
as well as among men crowded together, the 
fever aflTumes a pernicioas character, and becomes 
epizootic, 'imiieonrequence of the fame general 
caufes^iof infel^hrity. When it ,h§se#ade lome 
progrefs, the miafmata which evaporate from a 
great number of difeafed animals may in like 
manner exercife a very flriking contagious influ- 
ence on the lungs of thofe which, not b^ing yet 
infeded, are much difpofed to become fori^ir-tP 

The belief that the progrefs of epizootics could 
be checked only by a general Jlaughter of the dif- 
eafed animals muft, no doubt, have arifen from 
ignorance in regard to this difeafe ; to its caufes, 
and to its mode of propagation ; and the dread of 

>Tnfe<^ion; has -been carried fo far. ^as to produce 
orders for, the deftrud^ioH, of the hides, and of 
dvery thing applied to the ujfe pf. the, eattl^j^ 
' It does not appear that animals experience the 
difeafe under the remittent type, with paroxyfms 
\vhich regularly recur ; and it is a very Angular 

:^ecaliarity, that neither t^rtiajn jiprqviartatj 'fever 
is obferved among theiD.3ra3gnBi^b fBt^nog isrft 

smolqra,^) lQ.«t,noi ieriJ Ha dtiw, .-isva^ astmiilnbo. 
'^^ -209^ AlmoU all the difeafe§i erf which a iliprt 
view ftill remains to be given are^ owing to the 

' circumftances of civilization, Thev confift in g 

1. 4 derange- 


derangement of the nervous adlion/which may be 
fafpended, weakened, increafed^ or changed. 

Some of thefe afFedlions are produced by the 
impreffion of foreign caufes ; but the greater 
number are the refiilt of a bad ufe of the differ- 
ent fundions. All thefeataxiie fhow themfelves, 
for the moft part, without febrile fy mptoms. 

210. The nervous adion is fufpended, in a 
great liieafure, in afphyxia, catalepfy, fyncope, 
and apoplexy, which conllitute the comatofe af- 
fedlions. ' Corttata. 

The afphyxiae arife, for the moft part, from 
gafeous ^fubflancesj which when introduced into 
the lungs produce on the nerves of tbatorgan an 
a61ion ftill more violent thanihat of the miafma 
of the plague ; and occafion'a general derange- 
ment of the nervous a6lion, without' leaving any 
traces of the affeftion on the organ iirft attacked, 
Hence, in large cities, where fo man^"' caufes of 
infedtion are accumulated,- the mialrnata which 
arife under certain peculiar circumftances from 
privies, tombs, common fewers, &c. ; the dif- 
engagement of carbonic acid gas, which fo often 
takes place in fermentation, combuftion, and, cal- 
cination ; the nitrous and ammoniacal, &c. gafes, 
received into the lungs, fuddenly produce vertigo, 
convulfions, fainting, and apparent death, which 
without fpeedy afliftance foon becomes real. 



Thefe difeafes, which are real polfoning by the 
lungs, muft be diftinguifhed (torn the afphyxiae, 
which take place in confequence of- the mere 
privation of the oxygen of the air ; as when one 
is immerfed in a medium in which none of it is 
contained, and which however exercifes no pre- 
judicial aftion on the organ of refpiratign : fuch 
are the cafes of immerlion in water, in azotic gas, 
or in hydrogen gas. 

In the lafi: place, afphyxia may be produced by 
the continued aftion of cold. 

In every cafe of afphyxia, whether the difeate 
has been produced by the interception of atmo- 
fpheric air from the lungs ; by, the infpiration of 
any gas not, proper for refpiration, or by that of 
poifonous vapours ; or by the continued ad:ion of 
cold ; it is always proper to remove the indivi- 
duals, as fpeedily as poffible, from the 'caufes of 
the afphyxise, and then to recall the vital aftion 
by different ftimulants. 

In afphyxia, the a6lion of the fenfes is fuA 
pended ; refpiration and circulation are inter- 
rupted, and the body differs from a carcafe only 
vby the remains of heat. An individual may 
fometimes be reftored to life after being in this 
flate an hour, and even much more j but after at 
longer period refufcitation is impoffible. 

211. It appears that, in fome very rare cafes, a 



violent mental affedion, a great dirappointment, 
flrong indignation, ecilaiies and myftic contem- 
plation, and particularly among women, may 
lead to a ftate of ftupor and complete inleniibi- 
lity, with permanency in the attitude in which the 
iizdividuah were when attacked, or in that in which 
they are placed hy others. It appears that this ftate 
may continue twenty-four hours ; after which 
fenfation and motion gradually return, as if after 
Heep, without any remembrance of what took 
placq during the catalepjy, 

111. The ftate of fyncope, by which the indf-* 
vidual is inftantaneoufly deprived of fenfation atM 
motion, with a weaknefs and even complete fuf- 
penfion of refpiration and circulation, feems to 
arife from an interruption of the afflux of blood 
towards the brain. 
'-IThis interruption may be produced by a fudden 
lofs of blood in a perfon while ftanding ; and 
after all exceffive evacuations. It frequently re- 
ftilts, alfo, from a fudden impreffion capable of 
weakening or fufpending the adlion of the heart 
and arteries ; which takes place in fome indivi- 
duals debilitated by long difeafe, and particularly 
in Ibme women, whofe weak Mhd irritable nei*ves 
difpofe them for being ftrongly affedled by all 
ftidden impreffions. . .i^- 1 i-^-; .i> . ..^^ - c . . 

- 213. WeaK- 


213. Weaknefs of the aAion of the brain feems 
to produce apoplexy, which varies in its intenfity 
from that announced a long time before by de- 
rangement or palfy of feveral organs, to that 
wfeif^hi' takes place fuddenly, and which ftrikes 
like lightning. 

t>'*jiVpoplexy frequently takes place in old age, 
and feems to fhow itfelf in preference during 
cold, damp weather, in individuals who have 
fuffered by exceffive labour, and by the privation 
of the neceflaries of life. Under certain circum* 
fiances it has appeared epidemic, and in certain 
places endemial. A difpofition to this malady 
feeftis to he communicated by generation. It 
frequently attacks men loaded with obefity j who 
have a fhort neck and a large head ; who take 
little exercifcj and who habitually indulge in an 
excefs of food. 

. Apoplexy may be produced alfo by compreffion, 
agitation, and laefion of the encephalic organ. 

This difeafe being for the moft part pi*o- 
duced by weaknefs of the cerebral organ, blee,d- 
ing and evacuants, fo frequently employ ed^ aye 
almoil always hurtful, p^^st dfoiffw rR^iTeih" 

Though the medical art furnifhes few refources 
capable of oppofing an afFeftion generally followed 
by relapfes, which at length become mortal, to- 
nics and varied fiiimulants are the propereft means 
for preventing the return of the difeafe. 



Even if apoplexy were produced by an eiTuiion 
of blood in the brain, bleeding would ftill be 
hurtful, fmcc it could have no ciFed in regard to 
the efFulion, and would deprive the patient of the 
ilrength neceflTary to produce a reforption of any 
effofed matter. 

Bleeding is proper only in thofe few cafes 
where apoplexy is produced by an afflux of 
felood towards the head ; in forne adults of a 
plethoric habit and ftrong conititution : in this 
cafe it ought to be copious, and fpeedily em- 

The diftinftion of apoplexy into fanguine and 
ferous is of no lignification. The ferous or fan- 
guine efFufionSj obferved fometimes in the cra- 
nium, are much rather the effecfl of the difeafe 
than its caufe. Mofl of the other organic altera- 
tions which have been found on opening the 
bodies of perfons who died of apoplexy, either in 
the cra,niumj the thorax, or the abdomeuj are 
produced by the general caufes which conduft 
llowly to apoplexy. 

214. There is no iyftem of organs in which 
the nervous aftion may not be interrupted, or 
weakened, to fuch -a' degree as to be deprived of 
the force necefiary for difcharging, in a proper 
manner, the fundions affigned to it. This 
Itaie of afilmla varies from flight debility to com- 

' pleta 


plete palfy, and exhibits peculiar phenomena ac- 
cording to the organs affefted. 

In the mufcnlar fyflem, aflhenia produces 
debility, tremor, and palfy ; and, according to 
the parts attacked, St. Vitus's dance, torticollis, 
aphonia, &c. 

In the fyitem of the nerves, the eye exhibits 
all the intermediate degrees between weaknefs 
and paliy of the optic nerve ; which according 
to fome peculiar charafters gives amblyopia, heme- 
'ralopia,. nydlalopia, and amaurofis or blindnefs. 

In the ear, the different ftates of afthenia of 
the acouftic nerve give .various affeftions of that 
organ, from dullnefs of hearing, in a greater or 
lefs degree, to complete deafnefs. 

The cafe may be the fame in regard to the 
fenfes of fmelling, tafling, and touching. 

Weaknefs of th6 nervous a6i;ion, in the fytlem 
of digeftion, produces lofs of appetite, or ano- 
rexia ; in the pulmonary organs, difficulty of re- 
fpiration, or dyfpnea and afthma : in the fyftem of 
generation, this weaknefs varies from dyfpsrma- 
tifmus to impotence or anaphrodifia. 

Pal fies are always incurable: the weaknefs re- 
quires the aid of varied exciting medicines and 
tonics, either applied to the organization in ge- 
neral, or to the d§bilitated part. 

215. The nervous a(fl;ian of our prgans, inde- 
5 pendently 

15S REFLECTIGN"^ ON tilt: 

pendently of the different flates bf weaknefs of 
which it is fufceptible, may contra6l alfo a griilt' 
degree of mobility ; it may want proper fteadinefs, 
and be habitually exercifed only with derange- 
ment and di(()rder. It then gives rife to a ferisg ' 
of convulfive afte6\ions, fometimes continued, but' 
almoft for the moft part intermittent, and always 
fubjeft to periodical returns. Thefe affections ge- 
nerally refult from a natural weaknefs of c6nll:i- 
tution, a vicious education, and the improper ufc 
of the voluntary fun6tions. 

This particular flate of nervous action pro- 
duces in the fyftem of circulation and refpi- 
ration: palpitations of the heart, convulfions of 
the larynx, cramp of the thorax, convulfive 

In the fv'flem of digef1:ion it produces convuU 
lions of the oefophagus, hiccup, vomiting, pains in 
the f^omach (cardialgia) ; it gives rife to convul- 
lions properly fo called, and totetanus; in the 
mufcular fyflem this mode of derangement appears 
in the whole of the organization, during par- 
oxyfms of madnels, epilepfy, and byflerics. 

In the lafl place, deVa:ngement of the nervods 
a<5tion produces different diforders which are ob- 
ferved in the intellet5lual fan6lidti^^''":^^K/V. 

Moft of the convulfive xlifeafes have been cori- 
lidered as local afFe6tions ; they however depend; 
for the moft part, on a general derangement, 



which fhovvs itfelf, ia preference, in fome parti- 
cular organs. ., 

It is of. importance that we fhould here defcrlbe> 
"vvith fome mlnutenefs, thofe general caufes ca- 
pable of producing thefe nervous affe6tions, which 
are become fo frequent in large cities among one 
clafs of fociety. To comprehend thefe caufes, it 
mull always be remembered that health is the re- 
fult of a proper difcharge of the different func- 
tipnsr.that thefe fundions mud be habitually 
performed, as if each organ ought to confume a 
determinate quantity of nervous action, which ab- 
folutely requires to be ufed ; that the organs are 
ftrengthened by moderate exercife, and weakened ^ 
by forced exercife and _ by reft, &c. In a vvordy 
it mull be remembered that all particular affec- 
tions, are jcapable of being tranfraitted, at leafl 
in part, by the means of generation. ft-^§noi. 

Thus, in the opulent clafs, women of a delicate- 
conftitution, whofe weak and unfteady nervous ,; 
adlion renders them fubjedl to what are called- 
nervous affeiflions, experience in general difHcult- 
parturition,, are. fubjeft ,.iOc,fcquent mifcarriages, 
and. bring forth. weak. deUcate children like, them- 
felves^^^^^.^^^, ^^^^^^-^-j^ j^g^g-jj-j^ 293uboiq uoit'^z 

It is obferved, thatf/uch rchi-ldren are fubje^l. ta • 
interruptions-in their fleep,fubfultustendinum3 and 
frejqueiit colics; and that. their.dentition, : always 
difficult, is, accompanied with convullVopSff &c. . 



It is not advantageous for thefe children to be 
fuckled by their mothers, who aflbciating them 
to their manners an^J habits, ftipply them with milk 
which affords little nourifnment, and which pof- 
fefles the irritating charafter of the produfts of all 
the fecretions, in a certain flate of weaknefs or 

It would be much better if they were fent to 
the country, and committed into the hands of 
nurfes whofe limple manners and mode of life, 
more agreeable to the laws of the organization, 
would gradually corre6t their primitive dangerous 

But if they remain with their parents, the latter^ 
through a miftaken fondnefs, never fuffer them to 
be abfent from their fight ; they do not allow them 
a moment of liberty to take that exercife which 
is neceflary for the complete development of their 
organization. Being always near them, they ma- 
nifefi; a continual uneaiinefs left their health 
iliould be deranged. Thefe children, overloaded 
with clothes, and particularly on the head, fed 
in an improper manner, and deprived of exercife, 
are expofed to frequent colds and often to horrid 
eruptions. In confequence of an oppofite abufe, 
we often fee other children equally delicate and 
weak, kept habitually naked under a damp, cold 
temperature, become fubjeft to catarrhal affec- 
tions, and to rheumatifms exceedingly troublefome. 



When thefe children begin to grow up, the 
parents, who never fuffer them to be out of their 
fight, calculate with fcrupulous minutenefs the 
refult of every ftep they make, and of ev6ry mor- 
fel they eat. They repeat to them a thoufand 
times a day, to take care of their health ; that 
they will be hurt j that they are going to die of 
hunger, or pcrifb by indigeftion. Thefe beings, 
perpetually ftunned in this manner, gradually ac- 
quire a habit of fear, and, notwithftanding the 
pliability of their age, often become weak and 

On the other hand, through a fear Of dif- 
pleafing or vexing them, they are never checked 
in their extravagant whims ; they are fufFered to 
gratify all their caprices, even at the expenfe of 
thofe around them ; and they thus acquire a habit 
of obftinacy and domineering, to which they are 
all ftrongly inclined* 

Far happier are the children who are not reared 
Under the immediate eye cf their parents ; nature 
with lefs trouble fucceeds much better in deve* 
loping their organs, and in forming their under- 

In another clafs of fociety, among the indigent 
inhabitants of townSj children are aflbciated, 
during their earlieft years, in the wretchednefs of 
their parents, and the difeafes it brings along with 
it. Thefe children are then educated under a 

VOL. III. H • continual 


^OBtiniial fear of brutal and b-Iind feverlty, fur- 
, rounded by vulgar prejudices aiad the, moll abfurd 

Thefe two kinds of education though in ap- 
pearance diametrically oppofite, produce almoft 
the fanye general refults. 

As the children here alliuded to grow up, and 
their intelle^lual powers- begin to expand, they" 
aj?e foon coinpelled to remeniber things which 
they do not underfland ; their minds are occupied 
with nothing but the wonderful events of hiftory, 
the abfurd fables of mythology, and the H3,yfi:eries 
of religion. They are neven allowed to think, 
for themfelves J and in this manner they are gra- 
dually accuUonied to believe in things i-nconceiv- 
ai)le and fupernatural. 

During the firfl period of youth, childrren of 
both /exes receive nearly the fame mode of edu- 
cation ; but when they begin to approach the agie 
of puberty their fituations are changed. 

Boys are allowed, more liberty, and by proper? 
exercife correcl, ia fome meafure, the vicious^ r^ 
fults of their firft education. 

In a word, the inftru6iion given to them, relates 
chiefly to literature and the fine arts; they com- 
plete their ftudies v,?ithout having an idea of tlier 
exacl fciences ; they are unacquainted with, the 
reafon of any of the phaenomena. which daily take 
place before their eyes, and in their organiza- 
tion ; 


tioh ; they reftiain perfe6l ftrangers to every thing 
aronrtd them ; fpericJ their lives like blind perfons 
groping their way through farrounding objedls, 
and ferve a contintral and unfruitful apprentice- 

Thefe" menv however, who are niot deftined to' 
th^ rt^echsmrcal aVts,- piwfue in foeiety different 
dife^lions^-M' ^hiob it is of inhpoftance to follow 

Thofe who apply to. commerce and butinefs are 
m a -fitCiatibn where they may enjoy pretty g6od? 
health, if their occupations obligS" them to take' 
proper daily exercife, and if they live with fobri'-' 
dty a^rid temperance ; but xi/h'^ri they pafs the 
greater part of their lives' iti' the connfing-houfe^ 
or in the clofer, and when th6ir principal enjoy- 
rni6nts coniilt i'n the pleafutes of the table, they 
always at lettg^th becorfte fubjedl^ to fome of thofe 
nervous affe(5^ions of which we have already 
fpoken. The ilow and continued progrCls of 
thefe difeafes induces them to Confult all the 
medical men with whom they arc, acquainted ; 
and they generally follow the advice 6{ thofe who 
give them the mod extravagant prefcriptibn^, and 
thus often render their lituation much more dan- 

Thofe who purfue a military career in the 
time of war, lead a kind of life exceedingly pro- 
per fbf producing a ftrorig conliitution, provided 

M 2 they 


they are able to fupport the fird fatigues, and if 
thej live with temperance. Taking frequent and 
ftrong exercife,, by which all the faculties may be 
expanc!ed ; living alternately in different climates; 
iifing all kinds of food ; ileeping often under 
tents or in the open air ; and having no fixed 
hours for repofe or for meals ; they are fubje6l to 
no habits, and give to their organs all that ftrength 
of which they are fufceptible. 

This mode of life approaches very near to that 
©f people in the hunter flate ; who have always 
exhibited a very linking fuperiority of organiza- 

, Thofe who devote themfelves to literature and 
the fine arts are expofed to nearly the fame kind 
of life as merchants, or perfons in office, and, 
like them, are fubjecl to the fame affections ; for 
the cure of which they are often feen to employ 
the mofl improper means, while they negle(5t the 
moft fimple and falutary. 

It is very afionifliing, that thofe who produce 
the mofi: admirable v^rorks in the imitative arts 
fhould be entirely ftrangers to the principles of 
philofophy, and often flaves to the moil ridiculous 

Among fuch perfons, we often find fome whofe 
luxuriant imaginations are always producing a 
whimfical mixture of ingenious fi6f ions and agree- 
able chimeras^ embellilhed by the beauties of 
a dieiion.. 


di<5i:ion. Thefe amiable fook are received and 
encouraged by the numerous clafs of the idle 
and ignorant, whom nothing pleafes fo much as 
the wildeft flights of the imagination, which they 
confider as the flrongeft marks of genius. 

In the laft place, there is a fmall clafs of idle 
perfons, who, through a defe61 in their early edu- 
cation, are left in a fituation ftill more difagree- 
able ; they are gloomy, reftlefs, and continually 
occupied with the feeble ftate of their health j a 
prey to melancholy mental afFe(5lions : in this 
manner they languifh for a long time, and at 
length become hypochondriac. 

Thefe unfortunate confequences of a bad early 
education feem to have been felt only in a very 
flight manner ; and it appears that the quefl:ion. 
What is the befb education ? remains ftill to be 
folved, for want of having been properly pro- 

The obje(5l of the flrfl: education oitght to be 
to produce that development which is befl; fuited 
to the whole of the functions, and to teach thofe 
things which may be of the greatefl: utility 
throughout life to the majority of citizens of the" 
different clafl^s. 

Thus, with the fiudy of one's mother tongue 
and of the mathematics, a knowledge of natural 
philofophy, chemiftry, and phyfiology, ought to 
form the bafis of every good education, 

M 3 During 


Dunng eduGation, care fhpujd be takerij by 
varied exercifes, to favour, iii a proper proportion, 
the development and llreMgtli of the mufcular 
fyftem, of the organs of the fences, .^nd of the in- 
telledual fun (9: ions; and it ought never to be for- 
gotten that the predominance of a fuiicFtion alvvays 
takes place at the expenfe of foms.e of the relt. 

It will be proper in the different exercifes, as 
well as in regard to meals and to fleep, to avoid 
that daily regularity which, in the courfe of time, 
renders men (imilar to thofe machines which can 
be kept in motion only by winding them up 
every day, at the fame hour, and in the fame 

The bcft habit to be contradled is that of hav- 
ing none. The empire of habit difpofes people 
for being afFe^ied by every change and by all 
fudden variations ; it Hkewife becomes an ob- 
ftacie to new difcoveries, by confining thofe fub- 
je<£l to its influence to the comnjon hackneyed 

a 1 6. Yptjng women, in the opulent clafs of 
fociety, h^ve often fewer opporiunitjes of elcap- 
ing from the baneful influence of a rxiijlakpn pdn? 
cation : iq general, they are under much greater 
reftrajnt than boys, and cannot fo eafily indulge 
in that exercife which their ^ge requires. The 
chief part of their attention i§ turned to the or- 
6 nam.ental 


namentaJ parts of educati<jn ;f4h^^/;i"ienfibly ac- 
quire a habit of indoience^aiad at length are 
reduced to fuch a Itate that it is impoffible 
for them (o be active. Their \\^k and delicate 
organs acquire a high degree^of tifrritability, and 
become exceedingly fenfible to the flighted im- 
preffions. Some of them, even in their earlleft 
youth, feel the confequences of this kind of life : 
they are fubje^: to frequent indifpofitionj to flight 
nervous affedlions, to frequent irregularities in 
theexercife of their diiFerent funciions. Thefe 
individuals, however, feem to enjoy good 
health ,• have a frefh complexion, difplay perfonal 
graces and talents ; poflefs great livelinefs, and 
feem to unite all thofe qualities which are calcu- 
lated to pleafe : but, in general, they refemble 
plants cultivated at great expenfe in hot-houfes: 
they often exhibit the fame glowing colours as 
thofe which grow in the natural ftate; but they 
have neither the fame vigour nor the fame per- 

The exiftence, in fortie meafure artificial, of a 
great number of thefe women, who have acquired 
a habit of living in a date of the moft complete 
idlenefs, is a circum fiance exceedingly curious in 
phyfiology. If their fituation be minutely ex- 
amined, even at a time when they do not appear 
to be in bad health, it will be found that the 
greater part of their functions are reduced to a 
M 4 minimum 


minimum of a6lion, and that fome of them ex- 
hibit wonderful alternations of extraordinary de« 
bility and exertion. Thus the mufcular fyflem, 
which is incapable of habitually enduring very 
gentle and continued exercife, is capable of over-!' 
coming the greatefl; efforts in paroxyfms of hy^ 
flerics. The intellectual organ appears to be ex-? 
ceedingly delicate ; it can fpeedily give birth to 
the moft ingenious failles and repartees ; but the 
attention cannot long remain fixed to the fame 
object. The organs of the fenfes, pofTefling great 
irritability, are difagreeably afFedled by all violent 
imprellions ; by hideous forms, ftrong odours, 
a harfh found, or the flightefl touch. All 
fudden and unufual fenfations produce fyn- 
copes, or other nervous afFedions exceedingly 

Such females have fcarcely any appetite j they 
take very little food, and prefer highly feafoned 
aliments deflitute of nourifhment. In a word, 
they are fubje(Sl to habitual coflivenefs ; the urln? 
is fcarce, pellucid, and often inodorous ; perfpi- 
ration is hardly fenfible ; the fkin is cool and 
pale, and either void of odour, or emits a very 
peculiar one; refpiration is fhort; the pulfe is flow 
or accelerated, but habitually weak. The delire 
of venery is either annihilated or tranlient ; there 
exifi:s, for th^ moft part^ a habitual leucorrhcea. 



If this ftate be compared with that of a young 
female whofe organs have acquired proper ex- ' 
panfion, a difference fo great will be obferved, 
that it will fcarcely be poffible to conceive how 
the phyfical faculties, among the former, could 
be reduced to a permanent flate of debility lb 
near a-kin to death. 

The varied derangements, produced by the 
want of occupation, or the bad dire6iion of the 
nervous power in general, have been very frequent, 
efpecially among the female fex, at a period not 
very remote, when the numerous clafs of the 
nobility, and thofe devoted to monaftic feclufion, 
were condemned, by their lituations, to a ftate of 
indolence, and when a fort of infamy was attach- 
ed to bufinefs. This ridiculous prejudice induced 
a great number of individuals to expofe them- 
felves to great toil and labour during a part of 
their lives, in order to acquire fpeedily, with opu- 
lence, the noble privilege of flowly peri(hing by 
languor, difeafe, and confumption. 

It was among this clafs of the rich and the in- 
dolent that the moft complete abufe of all th^ 
organic funfbions was obferved. 

Hence the mufcular fyftem, which fo imperi- 
oufly requires that its fundions Ihould be exer- 
cifed, is condemned to abfolute reft in indivi- 
duals who do not even take the trouble to walk. 



Th€ table, decked out with profufion, prefents 
highly flicculent food, proper for repairing the 
lo(ies .they have not fuftained. Spiceries, which 
ought to be united only with fubftances difficult 
of digeftion, are combined with the extradls of 
nutritive parts ; and yet thefe ftimulants become 
necetTary for exciting the enfeebled organs, and 
for procuring a few new fenfations. 

The llomach, thus Simulated beyond meafure, 
receives ufelefs aliment, on which it exercifes a 
continual and laborious effort j while all thefe dif- 
orders are increafed by the abufe of generous 
wines and of fpiritous liquors. 

In fome, the organ of reproduclion is incef- 
fantly fiimulated by all the means which nature 
or art can fupply ; and an immoderate ufe is 
made of it, which tends fpecdily to confume life : 
in others, a continence determined by civil or re- 
ligious confiderations is engaged in a continual 
llruggle Vv'ith all thofe means which are calculated 
to excite venereal defires. 

In a great many, the intelleclual organ is con- 
tinually difordered by different pafiions, and by 
the arts of imitatron or of the imagination. In 
this ftate it may acquire an immoderate exaltation, 
approaching near to madnefs, when not checked 
by a fenfe'of focial duty, and by the prefent boun- 
dAry_,.Qf,hiJi|}^|^. knowledge in ihe exact fciences. 
"""'"'" ' '' - it 


It needs excite no aftonifhment, that fo de- 
prived a Life of the iinoft Important of all the func- 
tions fhoqld in the cpjurTe of tiijjg. produce to 
great 4 era ngejTi e n ts. ■I'r'fi -id 

Thele nerv',ou,s iafTediions, 3 part of which are 
commonly dillingui(hed by the vulggr appellation 
of th^e vapows, have by many bten confidered as 
merely imaginary *, becaufe they often occur in 
individuals who exhibit every appearance o( being 
in perfect health. They however conftitnte very 
painful difeafes, which at firft exift without any 
organic alterations ; but which at length give 
rife to changes of this kind, and thus become 
combined with the afFe^ions which they produce. 

Nervous affedions, in general, attack perfons 
only whofe intelle61ual fundlions are kept in an 
habitual ftate of adivity; which fuppofes the 
cjontinaed adion of the different organs of the 
fenfes, lince the intelle6lual organ ran combine 
only fenfations which have been received. 

Continual and almoft exclufive exercife of the 
organs of the fenfes, and of the intelledtual func- 
tions, tends to raife them to the higheft degree 
c)f improvement ; but the other fyfreme of fonc- 
tipnpj and particularly thofe of motion and digef- 

* Young females, either from a defire of being fafliionable, 
or of attracting more notice, have bceri feen to iinitate all 
the manners of thofe really affefted with hyfterids, andby thefe 
means become much fooner hjftericaL 



tion, if not fubjedled to proper exercife, become 
weaketled ; and as all the organic lyftems are 
conncifled, and have a mutual dependence on' 
each other, it thence follows that as thefe organs 
are weakened and deranged, the organs which 
receive the fenfations, and that which combines 
them, are deranged in the fame ratio, and at length 
become incapable of performing their functions 
with that regularity which they muft acquire by 
long and continual exercife. 

On the other hand, men who live in a conti-, 
Dual ftate of apathy, without curiolity, without 
fear, and without ambition ; who make only a 
very limited ufe of the organs of fenfe and of the 
intelledlual fundlions ; who place their whole en- 
joyment in the pleafures of the table, and in in- 
tercourfe with the female fex, are not fiibje6l to 
thefe affeflions ; and may fpend the greater part 
of their lives in a ftate of inaftivity without 
any bad confequence to the organization : exer- 
cife of the organ of generation is that which 
fupplies, with moft advantage, a deficiency of 
employment to the organs of loco-motion. When 
fuch men have a ftrong gaftric fyftem, and employ 
a great part of their time in digefling properly, 
by leading in the lap of abundance a life merely 
vegetative, they generally become loaded with 
flefh, which is attended with all the inconve- 
i^^iences peculiar to obetity. 



During the courfe of the French revolution, 
numerous examples occurred, which evidently 
prove that all this order of di^eafes was merely 
the refult of that idlenefs which prevails amidft 
opulence and luxury ; and that exercife, ufeful 
occupation, and a temperate life, are fufficient 
to check its progrefs, and to bring back health. 
Among the perfons crufhed amidft that na- 
tional fhock were a great many debilitated fe- 
males habitually fubjeft to difeafe : thefe indo- 
lent females, compelled to fly, to take exercife, 
to attend to the care of their exiftence and to 
their fafety, and who were even conftrained to 
begin to work that they might procure the ne^ 
ceiiaries of life, acquired in this aftive and labo- 
rious ftate ftrength and energy, and ceafed to be 
a prey to nervous afFe6lions. 

It was from this order of difeafes that phyfi- 
cians derived the grcateft benefit : thofe in vogue 
maintained their carriages by the nervous affec- 
tions of the opulent. 

It was alfo by this order of difeafes that t/je art 
of writing pref cript ions ^ which had become almofi: 
entirely the whole art of medicine, was mofl: ex- 
ercifed and improved. To be daily obliged to fee 
patients, who conf|antly recited the highly varied 
feries of the fymptoms of the fame affedion, and at 
each vifit to prcfcribe fomething whi^h fhould have 
the appearance of novelty, and which* at the 
■ ^ fame 


fame time, fliduld afford a certain degree of re- 
lief, was a tallt which requifed a confiderable 
fhare of fagacity. The prefcriptions, however, 
for the refpedl paid to them were irfdebted to the 
firange language in which they Were written, 
and to the chara6iers which rendered them unin- 



' <.5[r!iJ ^rm. 






3. We have examined the material ftru(5ture 
of the lyftems of the different fundlions, in organ- 
ized beings in general, and in man in particular, 
giving a detailed defcnption of the forms, relation, 
and ufes of the different parts of which they con- 
lifl:, and we have added various phyfical obfer- 
vations, with the refult of the chemical analyfis 
made of them. 

We have al fo given a hiflory of the deratige- 
ments to which the different anatomical fyflems 
of organs, the various fundi ions, and the organiza- 
tion in general, are fubje(5l:. It therefore re- 
mains that we flioald exhibit a view of the vital 
phicnomena, in the organization in general, and 
confider the peculiar fqnftions and reciprocal ac- 
tion of each fyftem of organs, 

a. In taking a general furvey of the whole 

organization, we every where obferve veffels and 

70L, iir, N nerves 


nerves in fuch quantity, that it appears that the 
whole organic flrudhire is compofed of only two 
orders of parts_, which by their different interfec- 
tions form numerous tiifues. In the cells or are- 
olae of all thefe tifllies are depofited the albumi- 
nous, gelatinous, adipofe, faline, Sec. juices, of 
which the veflels and nerves themfelves are com- 

The vefTels form almoftthe whole of the tifllies 5 
they convey the materials intended to ferve for the 
nutrition of all the parts, and carry back the re- 
fidue of all the fecretions. The nerves diftribute 
the principle of adlion to every part, fo that the 
heart and the brain, the principal centres of thefe 
parts, are evidently the moft important organs. 
The cerebral fyfiera and the nerves ought, how- 
ever, to be coniidered as the organs mofl eflential 
to life ; lince they diftribute the principala^lion 
to every pait of the body. 

It refults from thefe principles, that the dif- 
ferent fyftems of organs which efTentially confill 
of tiiTaes, formed by the veilels, may be conii- 
dered, in general, as infiruments ; and the nerves 
which are diftributed thither as the power which 
puts them into a£lion. 

We fliall lirfl: confider the general povv^er of the 
organ v»'hich communicates- motion ; and then 
examine the a6lion of the different infiruments 
which it puts in motion, 

' ' j.The 

Action of the brain and nerves, jyg 

3. The cerebral and nervous fyflem are efTen- 
tially compoled of the encephalon, the rachidian. 
prolongation^ the trifplanchnic, and the nerves '. 
which are continued with thefe parts, and which 
are diflributed to all the organs. 

The perfedibility of the cerebral organ Teems 
to depend on the fize of the encephalon, and on 
the tenuity of the nerves. We obferve, indeed, 
that the encephalon of man is proportionally 
larger than that of other animals ; and that his 
nerves are fmaller and more numerous. The lize 
of the furface of the brain is increafed by its nu- 
merous and profound anfra6luofities. The differ-, 
ent fe6lions made in that organ exhibit a great 
many eminences, cavities, and flrata of various 
forms and colours, with the ufes of which w« are 
unacquainted, but which are evidently more nu- 
merous than in that of other animals. In a word, 
it is obferved that the cerebrum, the cerebellum, 
and the mefencephalon of man are lefs diftin6l, 
and feem tD be more confounded, than thofe of 
other animals. 

The encephalon is not„ a pulpy mafs, and 
every tbjng feems to give us reafon to believe 
that it is a vSry important organ of fecretion; 
It is indeed obferved that it receives about a fixth 
part of the blood, which is conveyed from the 
lungs by a very fhort paflage ; the cerebral arte- 

K 2 ries 

'■*..-'v ^vi 


rles are uncovered, that is to fay, have no cellular 
tunics i they exhibit frequent anaftomofes; arc 
indefinitely ramified over the large furface of the 
brain, then enter the interior part of it, and im- 
mediately difappear. 

It is not improbable that thefe arteries, by their 
indefinite divifion, are foon changed into ferous 
veflels exceedingly fmall. The blood then returns 
from the encephalon by numerous tortuous veins, 
which depofit it at certain intervals in finufes, 
where it remains for a longer or fhorter period. 

The encephalon gives birth to twelve pairs of 
nerves, which are diftributed to the face, to the 
cranium, to the neck, to the breafl:, and as far 
as the flomach. Of thefe nerves the optic and 
the ethmoidal arife from the brain, and the refl 
from the mefencephalon : none are furnifhed by 
the cerebellum. 

The rachidian prolongation gives thirty pairs 
of nerves, which ifTue through the vertebral holes, 
and are diftributed to the neighbouring parts. 

The trifplanchnic gives birth to the nerves 
which are eflentially diilributed to the organs of 
circulation, of digeftion, and of refpiration. The 
encephalic and rachidian nerves form, by their 
union, the nerves of the limbs. 

In the laft place, the nerves of all the parts 
have a communication with each other, and 



with the encephalon, in a manner more or lefs 

This lliort view, though very incomplete, Ts 
fufficient to fhow by analogy, that the brain 
mufl perform a very important fundiion, lince it 
is furnifhed with every thing neceffary for the 
moft perfe6l organ of fecretion ; that its fecre- 
tion muft be efFefted by means of veflels fo 
fine, that the long capillary canal of the tefticle 
exhibits only a very coarfe model of them, and 
that the refult of this fecretion mull be a fluid 
exceedingly rare. 

Thefe few obfervations, refpeding the anato- 
mical fi:ru6lure and diftribution of the cerebral 
and nervous organ, though not fufficiently fatis- 
faftory, may ferve, when united to accurate obfer- 
vation of the phjEUomena of life, to give a pretty 
extenfive idea of the function which it performs, 

4. Every part of the organisation confifts of 
a tifTueof veflels and nerves, in the interftices of 
which are depofited liquid or folid fubftances of 
different natures ; and under this point of view 
they may be coniidered as fo many organs of fe- 
cretion and excretion. The moleculae of matter 
which enter into their compofition are continually 
dillipated, and their place is fapplied by others 
which infenfibly afiume a peculiar arrangement. 
Paring this procels, the organic and living part 

N g always 


always jofes, by the inert matter depofited in thefe 
interftices,, fo that at length the latter impedes 
the vital a61ion, the organ then dies, and becomes 
fubjedl to the empire of general affinity. 
■ This vegetative or animal life, peculiar to every 
part of the organization, is performed by means 
of veflels which convey to them the materials of 
nutrition, and carry back the products of the fe- 
■ cretions. The a61ion of the veffels is maintained 
by the prefence of the nerves which accompany 
them, and which proceed in a particular manner 
from the trifplanchnic. ^ch feems to be the ge- 
neral mode of the vitality of a great number of 
vegetables and animals, each part of which is en- 
dowed with its own peculiar kind of life, without 
forming a necetfary and conftituent part of a 
whole, and may feparately procure to itfelf the 
materials of its nutrition. Thefe beings are fuf- 
ceptible of divifion, and are eafily reproduced 
from flips. 

But in bodies of a more compound organiza«. 
tion, and particularly in man, each living part 
forms a portion of the whole, and contributes to 
the formation of tho. d\&Q.vQntJ}Jiems of organs. 

The f)fl;ems of organs perform the fundlions 
peculiar to them, by means of particular nerves, 
and thus enjoy a new life. This organic life is 
that Vvhich is of the greateft importance. Thus a 
mufcle is compofed of a tiflue of veiTels^ v;hich has 



its proper life of nutrition. Thefe vefTels, by their 
contexture, form bundles of fibres fufceptible of 
contradlion ; and this contraction is performed by 
means of particular nerves. If thefe nerves are cut, 
contraction no longer takes place ; bat the muf- 
cle continues to live. 

The nerves which give vitality to the vefiels are 
furnifhed to them by the trifplanchnic : thefe 
nerves expand in the abdomen, over the principal 
trunks, and accompany them in all theif divifions 
and fubdivifions. The vefiels then can no longer 
be feparated from the nerves ; and carry every 
where with them, their principle of adlion. 

The nerves diftributed to the different fyftems 
of the organs come from the encephalon, or its ra- 
chidian prolongation, in large trunks Cufceptible 
of accidents, and on which experiments can be 

It has indeed been obferved, that as foon as a 
nerve has been cut, or a ligature has been formed 
on it, the fundion of the organ to which it is dif- 
tributed immediately ceafes. 

A nerve Vv'hich has been cut is captible of cica-» 
trizing like other parts, and of gradually reluming 
its a6lion *. 

If the mufcles of an animal, recently killed, be 

* See Haifjhton's experiments on this fubjeft in the Tranf- 
aftions of the Royal Society of London for 1795. 

jsr 4 irritated 


irritated by the point of a fcajpel, they contrad for 
a lonp-er or fhorter lime, and then ceafe to nnove j 
if they be fuffbred to remain at reft during a certain 
period, and be then irritated, they again contra£t, 
but in a weaker manner, and at length ceafe to be 
afFeded by the point of the inftrument : but if ex- 
cited by any other irritant, fuch as the Galvanic 
fluid, by making them form part of a Galvanic 
chain, they are once more feeri to exhibit contrac- 
tions : but at laft they become entirely motionlefs. 

It vi^ould appear from this feries of phasnomena, 
which the mufcles exhibit while irritated, that irri- 
tation makes them gradually lofefomething, which 
at length becomes completely exhaufted. 

It is obferved, in animals, that the contraction is 
in general more fenfible, as death has been fpee- 
dier ; and there is no contraflion when they die 
flowly after long fufFerings or violent convulfions, 
during which the nervous a61ion has been com- 
pletely exhaufted, 

5. The regular and fimultaneous exercife.of 
the adlion peculiar to each tiflue {a?iimal life), and 
of the action peculiar to the different fyftems of 
organs, which form thefe tifTues {organic life), con- 
ftitute life and health. 

It appears as if the cerebral lyftem, in the ex- 
ercife of its fundlions, fecreted a fluid analogous 
to the eledric fluid j as if it diftrihuted this fluid 



to every part of the body, by means of the nerves, 
which ferve it as condudlors ; and as if it commu- 
nicated to this fluid a peculiar movement, in con- 
fequence of which each organ performs the func- 
tion afligned to it. 

The hypotheiis of a nervous fluid, though high- 
ly probable, and as we may fay necefTary, ought 
to be conlidered only as a convenient method of 
explaining fa61s which cannot be difputed. 

In the exercife of its fundion, each organ feems 
to draw off, and to confume a part of this fluid. 

This fluid, deflined to be employed in an uni- 
form manner by all the fyftems of organs, may 
be employed by the forced exercife of one : in 
this cafe, the reft, without having been expofed 
to any exercife, are reduced to a Hate of inftan- 
taneous laflitude. • 

The nervous fluid, confumed during the exer- 
cife of the funftions, is repaired by reft. 

The nervous fluid, which is fecreted, abfolutely 
requires to be employed : when not habitually 
confumed, its readlion produces, in the different 
organs, derangements more or lefs ferious. 

The imprefiion made on the organs by the 
eontadl of foreign fubftances produces a change 
of aflion, more or lefs ftriking, according to the 
nature of thefe fubftances, and the ftrucilure of 
the organ which has been touched. 

The impreftion received gives to the nervous 



fluid of the part a movement, which is propagated 
as far as the brain : the a6iion of the latter is then 
augmented or changed. 

The movement of the reaction of the brain is 
immediately tranfmitted to the part which has re- 
ceived the impreffiqn, or to any other particular 
organ, or to the whole of the organization^ and 
produces varied phaenomena. 

When the natural a6lion of the parts is pro- 
perly Itimaiated, a fenfation of ea[& is the refalt % 
and when the fandlions are deranged a fenfation 
id{ pain is experienced. 

This fenfation appears always to be the refult of 
a reaction of the encephalic organ. 

The phenomena of life arc maintained by the 
prefence of different natural ftimulants, fuch as 
heat, the air, food, &c. Thefe fabftances, by 
Simulating the nervous a6}:ion of the organs, fup- 
ply them with the materials neceflary for the exer- 
cife of their functions. 

When an organ has been fubjeded to the ac- 
tion of a flimulant, the refult may be two. phasno- 
mena very diftin6l : ifl. The part performs; in a 
manner more or lefs apparent, the fundlion pecu- 
liar to it : 2d. The individual is confcious of tiie 
impreflion received. 

Every organ which is ftimulated tends to per^ 
form the func^tion peculiar to it. 

When the different organs of an animal, re- 



cently killed, are irritated by a powerful ftiinu- 
lant, each of them receives the impreffion, and 
anfvvers to it, according to its own manner. When 
the irritated organ, in confequence of the relation 
between its parts being deftroyed, cannot dif- 
charge the fundion for which it is deftined, it al« 
ways receives the impreffion, and the latter is then 
tranfmitted to diftant organs, where it may be- 
come apparent. 

The organic fvilem, on which the a6lion of 
ftimalants is exhibited in the moft evident man- 
ner, is that of the mufcles, becaufe its fundion 
is to produce motion. 

If an animal, recently killed, be placed in fuch 
a fituation that its different organs are interpofed 
in the chain of a ilrong Galvanic pile, the muf- 
cles become convulfed, the bladder contradls, the 
inteftines perform a fort of periftaltic motion, the 
motion of the heart is accelerated, &c. In organs 
which cannot execute the fun6lion peculiar to 
them, or which perform that function without any 
apparent motion, fuch as the liver, the fpleen, the 
kidneys, the ovaria, the matrix, &c. the impref- 
fion is alfo received, and when ftrong is tranfmit- 
ted to the mufcles of the pelvian limbs, which, 
in this cafe, are violently contrafted. Thefe ge- 
neral truths are fufficient to enable us to form a 
jufl eftimation of every thing that has been faid on 
the fubjedl of irritability, 

Co ijCioufjiefs 


Confcionfnejs of the impreffion received, or ^^n-' 
fation, appears, as already faid, to be the refuit 
of a readiion of the cerebral iyftem. Hence, when 
the natural relation is not interrupted, and when 
an organ is ftimulated, the impreffion is tranfmit- 
ted to this iyftem of organs; and according as the 
movement of reaction is regular, or as it is per- 
formed with trouble and diforder, the individual 
experiences a flate of eafe or of pain. Thefe 
obfervations may ferve to account for the aume" 
rous phcenorioena o( fen/ihility,^ 


[ 1S9 ] 


6„ The folid fupport of the body is formed by 
the bones, the arrangement of which determines 
the form of the individual, in the ftrudlure of the 

The flceleton is effentially formed by the trunk 
and the limbs. The trunk is compofed of three 
diftincl parts, the thorax, the head, and the 
pelvis : thefe three parts are united by the verte- 
bral column. 

The thorax contains the principal organ of cir- 
culation and thofe of refpiration ; the head con- 
tains the cerebral organ, which is continued along 
the rachidian cavity ; and the pelvis receives or 
fupports the principal organs of digeflion and 
thofe of geftat ion. The bones of the limbs, as 
well as thofe of the trunk, afford points to which^ 
the mufcles deflined to move them are attached. 

7. The different pieces of tlie ikeleton are 
united different ways : fome are fitted into each 
other by indentations ; others are united by plane 
furfaces j but the greater number are articulated 
by fmooth, round, and excavated furfaces. 



In tbefe different modes of connection, tlie 
furfaces are fometimes covered only by a thin 
membrane, as in the bones of the cranium, fome 
bones of the face, and the teeth* For the moft 
part, they are incrufted by a cartilaginous fub- 
Hance of greater or lefs thicknefs, and exceed- 
ingly elaftic ; as is the cafe with all the moveable 
articulations : in the laft place, a cartilaginous 
plate is found between the articular furfaces of 
the bones of the (boulder, of the knee, of the 
jaw, &c. 

The bones joined by indentations or by plane 
furfaces, without cartilaginous incruftation, are 
entirely motionlefs ; others perform movements^ 
which vary from the very obfcure motion of the 
-iones of the pelvis, of the vertebral column, of 
the tarllts. and metatarfus, to the very extenfiv* 
movements, in all diredions, performed by the 
bones of the arm on the fhoulder. 

The moveable articular furfaces are enveloped 
by a membranous capfule, and fecured by m^ans 
of ligaments. 

The articular and capfular furfaces fecrete a 
vifcid albumino«s liquor (fynovia), which renders 
the motion fofter and eafier. This liquid is takeu 
up by the abforbing vefTcls, and is continually re- 

The fecretion and abforption of this liquid are 



jnaintalned arid excited by motion : perfe6l and 
long continued repofe produces, at length, an 

8. The {yCtem of the bones is compofed of 
the bones properly fo called, the membrane by 
which they are enveloped, and the marrow con- 
tained in their cavity. 

The half of the mafs of the bones is compofed 
of veflels, nerves, gelatine, fibrous matter, Src. 
The veflels, by their interfedlion, form cells or 
areola, in which the hard part is depofited. 

The marrow is compofed of a vafcular and 
membranous reticulation, the vacuities of \vhichi 
are filled by a greafy and albuminous fluid. 

The vefTels and the nerves which proceed from 
the periofteum, and thofe which traverfe that 
membrane, penetrate into the fubftance of the 
bones, and are continued with the vefiels of that 
part, thofe of the interior periofleum, and thofe 
of the marrow. 

The organic and living part' is compofed of the 
aggregate of all thefe vefTels and nerves; and the 
phaenomena of oflification refult from the circu- 
lation, the fecretion and abforption which they 
continually exercife. 

The hard part of the bones is compofed of 
phofphate and.- carbonate of lime : the latter fait 
is in the proportion of a tenth. 

7 Tbe- 


The gelatinous or albuminous bones in the 
germ, pafs like all the other parts to the fibrous 
or filamentous ftate in the embryo^ and become 
cartilaginous in the foetus. 

The cartilaginous fiibfiiance gradually difap- 
pears during the lafi: months of geftation, and 
during the firft year of life, to give place to the 
faline matter^ from which the bones derive their 

The cartilaginous or ofi^ous ftate begins by 
points, like a kind of nuclei, around uhich are 
accumulated moleculce of the fame nature : thefe 
cartilaginous or ofleous points, by increafing, 
reach each other, unite, and are at length con- 

There are three points of offification for the 
long bones ; one, and frequently feveral, for the 
fhort bones. 

9. The bones when they become folid do not 
remain in that ftate : the molecule of the phof- 
phate and carbonate of lime, or their elementary 
parts, are continually difllpated, and replaced by 
others, which always afilime a different arrange- 
ment ; and in the courfe of this procefs the ac- 
cumulation of calcareous falts encroaches on the 
vafcular tifiue of the bones. 

It is indeed obferved, in infancy, that the bones 
are reddifh and pretty flexible ; at the adult age 



they become more compafl:,.and aflume a bluiih 
colour ; in old age they are dry and brittle, and 
exhibit a yellow afii colour, 

If an animal, the bo:v- 1 of which are flill in a 
ilate of growth, be t'cd *'ov forne time on mfidder, 
the bones bejoose covered with a rofe-coloured 
ftraturn on the outiide ; if the i^fe of this food 
be afterwards fufpended, they become covered 
with a new white ftratum, aiid the rofe-coloured 
llratum is more and more covered in the courfe 
of years. 

On the other hand, it is obferved, that the ca- 
vities of the long bones increafe in fize as the in- 
dividual grows older. 

It has hence been fuppofed that there is reafon 
to conclude, that bones which increafe in length 
and in breadth by development, increafe alfo 
in thicknefs by concentric flrata on the outiide, 
and that the long bones are dellroyed in like 
manner by concentric ftrata in the intide of their 
cavities, which confcquently increafe in fize. 

lo. In the phaenomenon of the coloration of 
the bones by madder, we muft not imagine that 
the coloured moleculae of that plant are depofited 
on the bones to give them a rofe' colour; nor 
rnuti we believe it to be abfolutely necefiary that 
thefe moleculae fhould be conveyed to the bones 
to change their habitual mode of adlion. 

VOL. III. o Foreigin 


Foreign fubflances do not circulate in tni^ 
manner in the organization ; and thdfe bodies 
fuppofed to be lufc^ptible of penetrating thither 
fb eafil)', are not found in the different parts. 

The a(5lion of the madder on the digeflive or- 
gans produces a rnode of adlion, psrticularly re- 
maikoblej li tLa fecretion of "ihe ofieous fub- 
flance, ?.r ^ ■ . 3n in the fecfetion of milk ; but the 
chyle 'lie ought to be the natural medium for 
conveying the madder into the mafs of ihe hloodj, 
and thence into the bones or the udder, aillimes 
no colour by the ufe of this root, 

II. The bones become difplaced, or are fub- 
je6^ to luxation, with greater or lefs facility, ac- 
cording to the nature of their articulation. 

A knowledge of the relation of the articular 
furfaces and of the foft parts by which they are 
furrounded, is fufficient to determine in what di- 
reftion luxations may take place : they are fuf. 
ficicnt alfo to determine the forces proper for re- 
ducing them. 

Luxations are .reduced with greater eafe the 
more recent they are : they may however be re- 
duced even when of long ilanding, but with 
much more difRcalty. 

When a bone remains in a ftats of luxatioOj, 
th-e preiTure and motion of its head give rife 
ibmetimes to the formation of a new articular 



capfule, at the expenfe of the neighbouring foft 
parts, which in the courfe of time aflumes a car- 
tilaginous and even ofleous texture : in this man- 
ner there is formed a new articulation, which ad- 
mits only of very confined movements. 

o 2s ACTION 

[ 196 ] 


12. 1 HE mufcles are formed of fibres in bun- 
dles : each fibre is compofed of feveral fmall 
fibres, and the fmall fibres are fubdivided into 
others ffill more minute. This indefinite fubdi- 
vifion, the termination of which cannot be per- 
ceived hy the beft infiruments, renders it impof- 
fible for us to know v/hat the nature of a fimple 
fibre is. 

The mufcles^ the bundles of fibres, the fibres 
and fmall fibres, are feparated by a covering of 
cellular tifi^ie, in which are accumulated thofe 
albuminous, gelatinous, and adipofe juices, a 
greater or fmaller quantity of which conftitutes 
the ftate of leannefs or fatnefs. 

The mufcular fibres, when flripped of all their 
coverings, exhibit, in their decompofition, a great 
deal of gluten or fibrous matter, a fubftance found 
only in the red part of the blood. 

The,mufcle§ are of a reddifli colour, and are 
terminated towards the point Vv'here they are at- 
tached by a very clofe fibrous tiflue,, of an en- 
amelly white colour, exceedingly elaftic, much 
lefs voluminous than the body of the mufcle, and 
which aiTumes the form of cords or bands. 

* * • ■ ^ Theie 


Thefe white fibrous parts, which conftitute 
the tendons and the aponeurofes, are eflentially 
formed of gelatinous fubftance ; and by decom- 
polition they do not furnilli gluten. 

13. When a mufcle is irritated, its fibres be- 
come fhortened, contrail, carry with them the 
moveable points to which they are attached, and 
thus produce the different motions. 

The mufcles begin to contra61 in the firfl: pe- 
riods of life, by the irrefiftible tendency to mo- 
tion which is experienced in the different flates 
of unealinefs, or of want ; but they gradually 
affume the habit of a more regular ■ exercife, 
and their being kept in continual ufe gradu- 
ally develops that force, pliablenefs and dexte- 
rity of motion to which they are capable of 

The force of the mufcles, in general, is in 
the ratio of their t hicknefs and of the length of 
their fibres. 

The mufcles, for the mofl: part, a6l in a very 
unfavourable manner ; they have a dire6lion al- 
moft parallel to that of the limbs ; they are at- 
tached very near to the centres of the articula- 
tions, and their power being frequently placed 
between the point of fupport and the refiftance, 
they form a lever of the moil difadvantageous 
kind. ' , 

o 3 The 


The ordinary force of the mufcular allien has 
been meafured in a pretty precife manner *; but 
under fome circumftances this a6lion exhibits 
inconceivable energy, which it is impoffible to 
appreciate. ~ 

The mufcles, under fome circumftances of life, 
overcome a refiftance by v^^hich they would be 
broken in the ftate of death. It is aftoni(hing to 
fee weak, delicate women, who are habitually 
without energy, exercife, during paroxyfms of the 
hyfterics, convulfive motions which can fcarcely 
be moderated by the mofl vigorous men. A 
llender delicate arm has frequently broken the 
Urongeft cords, dragged the heaviefl bodies, and 
thus produced efforts which could not have been 
performed by the robuft arm of a man in a ftate 
of coolnefs. 

The ftrength of the mufcles, the pliability and 
dexterity of their movements, are increafed by 
moderate exercife and the power of habit. Every 
body knows to what a degree of perfection the 
mobility and precifion of the movements of the 

* It refults from experiments made with the dj'nanometer, by 
C. Regnier, that a man of mean ftrength, when ftanding per- 
feftly ereft, can raife a vt'eight of 265 pounds, and that he can 
fqueeze any thing between his hands with a power equal to 10a 

Men and horfes may labour a whole day and exert one fifth 
of their abfolute ftrength. 

' ' mufcles 


mufcles of the limbs, and of the throat, may be 
carried' in tumblers, rope-dancers, and in parti- 
cular fingers ; and it may be readily conceived 
how unfatisfac^ory every chemical or mechanical 
explanation of this at^ion mud be. 

The mufcles fcarcely ever act fingly j and their 
different motions are always owing to the fimul- 
taneous or rapidly fucceflive adlion of a greater 
or lefs number. The indefinite combinations, of 
which their adlion is fufceptible, give to the limbs, 
by long exercife and the force of habit, the faculty 
of moving with an agility and a precifion truly 

Almofl: all thefe movements are thofe of fle6iion 
or extenfion : the flexor mufcles are called the 
antagonifi:s of the extenfors ; and the former are 
always ftronger than the latter, fo that the fi:ate 
of reli, of relaxation, or of equilibrium, is found 
in femi-fle£tion, a ftatc which the limbs naturally 
afibme during fleep. 

When the flexor mufcles contrail, the adVion 
of the extenfors ceafes, and vice verfd: during 
their concradlion, the mufcles become (horter and 
thicker, and form a projection which refills the 
preiTure of the hand. 

The mufcles, which are habitually exercifed, 
become more voluminous, alTume greater cQnfiit- 
ence and tenuity, and their colour becomes 
darker. Thefe organs, like all the reft, exercife 

p 4 their 


their fun(5ions by the influence of the nerves 
which feeni to convey to them the principle of 
a6^ion4 By long continued exercife the mufcles 
tonfume this principle of a6lion ; it even appears 
il.j-i they can draw it off from the other organs, 
and thus reduce them to an inftantaneous ftate 
of laffitude, which renders it impoffible for them 
to ad. 

14. The greateft proof that men are eflentially 
bipedes is. that they all walk on their two feet. 
We muft not, however, believe that this exercife 
is lo natural and fo familiar to them, that they 
can alL perform it with the fame facility. This 
excrcilbj as well as that of the other organs, re- 
quires a fort of ftudy, before it can be performed 
with all the advantage poffible. 

Standing is not a ftate of repofe^. but the effedl 
of continual extenfion. In this polition the bead, 
which has a flight tendency to incline forwards, 
requires to be kept back, and the whole body 
fixes itfelf in. fuch a manner that the centre of 
gravity falls between the two feet ; the fhoulders 
are thrown fo much the more backwards as the 
abdomen forms a more conliderable projection : 
this is particularly obferved in the ftate of preg- 

During the firft year of life, children cannot 
fland upright, becaufe their pelvian limbs are 



mil weakj fhort, and proportionally ilender ; be- 
caiife their head and abdomen, which, compara- 
tively fpeaking, are exceedingly voluminous, in- 
cline more ftrongly forwards; and becaufe their 
vertebral colnmn has fcarcely any curvature; 
but in the fecond year this difpoiition gradually 
decreafes, the child makes an effort to Hand^ 
keeps itfelf upright, and tries to walk. 


[ 202 ] 


15. Before we proceed further in explaming 
the phasnomena of our different fun(^ions, it will 
be proper to examine the general adlion which 
foreign fubftances have on our organization ; and 
this will naturally lead us to the organs of the 
fenfes, which bring us into relation with fur- 
rounding objedls. 

The bodies which touch us excrcife an action 
on our organs in proportion to their mafs, their 
velocity, and the chemical affinity of their mo- 
Jeculae j and according to the peculiar ilru61ure 
of the parts fufccptible of being alleded in a 
direct or an indirefl manner. 

The firfi: body which exercifes, an aftion on os 
by its weight, and which continues to a6l at every 
moment, is the atmofpheric air : its preffure on 
the whole furface of the body is enormous. But 
we are not fenfible of this preffure, becaufe it is 
continued ; becaufe the air which furrounds us is 
in equilibrio with that in the interior of our or- 
gans, and becaufe the fluids which, in a great 
meafure, compote the material part of our organi- 
zation, have need of the preffure of the atmo- 



iphere to keep them in the ftate of liquidity which 
renders them fit for that purpofe. 

The atmofpheric air, as well as all other fluids^ 
exercifes an equal preflure in every diredlion ; 
and its weight is in the ratio of its perpendi- 
cular height and the breadth of its bafe. The 
furface of the body has been efti mated at about 
1400 fquare feet ; confequently we experience 
from the atmofphere a prelTure equal to that of 
a column of mercury twenty-eight inches in 
height, and having a bafe of 1400 fquare feet, 
which makes about 30,000 pounds : an enormous 
weight, which, were it not for the reafons already 
nientioned, would crufh us to pieces. 

16. This preffure, to which we are habituated, 
becomes to neceffary, that we find ourfelves much 
indifpofed when we afcend to the top of a moun- 
tain, where it is much diminifhed. 

When the prefTnre of the atmofphere has been 
confiderably increafed, it produces a reftraint 
which cannot be long refifted : this is what takes 
place under the diving bell,- when a perfon de- 
fcends to a confiderable depth. 

17. All other heavy mafles, which exercife on 
our bodies an accidental action, may, according 
to their weight, bruife, crufli, or deftroy us ; and 
thus produce accidents more or lefs dangerous. 



Bodies which ftrike us exercife a Wronger ac- 
tion, according as their velocity is greater, and 
as the parts are lefs fitted or have had lefs time to 
yield to the fhock. 

All the molcculae of bodies exercife an a6tion 
on each other, called the force of affinity. This 
force exercifes a greater a(5lion according as the 
bodies are more divided, and as they mtuually 
touch each other in a greater number of points. 

The molecule of bodies which touch us in a 
flate of great divifion tend with greater or lets 
force to combine with our parts ; and this combi- 
nation is always a fort of alteration or deftrudlion, 
which the organization makes an effort to refifti 
This effort is exercifed by an increafed a6lion of 
the different organs ; fo that every fubfi:ance which 
tends to combirie with our parts, begins by fli- 
mulating them with more or lefs force, 

18. It is neceffary that our organs fhould habi- 
tually retain that temperature amidfl which they 
were developed. 

The organs, in a great meafure, are formed of 
tiffues of veflels, and the fum of the capillary vef- 
fels is much more confiderable than that of the 
large veilels. 

If the fluids contained in all thefe veffels fol- 
low^ed the different degrees of the temperature 
of the atmofphere, very confiderable changes 



would take place in the whole organization, by 
their ereater or lefs condenfation and rarefaftion ; 
and all thefe aqueous or adipofe fluids would 
freeze at a temperature below zero, and would 
melt or be evaporated at the ufual temperature of 
warm countries. 

Butj every organized being has the faculty of 
maintaining itfelf at the temperature proper for 
it 5 and when it is overcome by excefs of heat, or 
the violence of cold, it dies before its fluids ac- 
quire the temperature of the atmofphere. Hun- 
ter found this faculty even in vegetables. 

Man can endure changes of temperature much 
better perhaps than animals: he is found in the 
mofl different climates ; under the torrid zone, 
and on the borders of the frozen ocean. During 
long voyages, the fame men have experienced a 
variation in temperature of more than loo de- 
grees, during which the blood remains between 
38 and 40° (100 and 104" Fabren.) 

We are acquainted with no degree of tempe- 
rature under which man may not exift. The 
enormous degree of heat which Dr. Fordyce was 
gradually able to fupport is well known ; and we 
know, on the other hand, what extreme cold the 
natives of our climates have withftood, during: 
the very fevere winters in Canada, Siberia, Nova 
Zembla, and Spitzbergen. It appears, that with 
good clothing, abundance of food, vinous and 
5 alko- 

2G6 vital FUNCTIONPS. 

alkobolized liquors, but in particular proper ex* 
ercife, man in all climates may retain his habitual 

19. The organization affords different means 
for refifling cold and for fupporting heat. 

When a man is expofed to a low tempera- 
ture, the atmofphere draws off from him his 
caloric, and this lofs of heat reduces him to a 
fiate of uneafinefs, which excites him to motion. 
If he obeys this impulfe, he walks or labours 
with energy ; his refpiration and circulation are 
Jncreafed ; he has a greater appetite ; digeftion is 
fpeedier, and the difengagement of heat, which 
refults from thefe different fun 6f ions, is much 
more confiderable. On the other hand, the ac- 
tion of cold tends to thicken the texture of the 
Ikin ; cutaneous perfpiration is diminifhed, and 
the lofs of heat occafioned by its evaporation is 
much lefs. 

But, if the abflradlion of heat, effe6led by the 
atmofpheric air, be conliderably increafed, and if 
the vital a6fion is not fufHciently powerful to de- 
velop caloric, in proportion to the lofs of it which 
is occafioned, the individual is gradually weak- 
ened and exhaufled by the efforts of long re- 
a6tion, and falls^into a ilate of deep, which, un- 
lefs he receives fpeedy afliflance, foon becomes 
fatal. ' . 



In the moft northern climates, the favages go 
out to hunt during the fevereft cold ; and of thofe 
who are threatened with a flow and painful death, 
forne know that they can die in an eafier manner, 
by remaining expofed to the cold in a ftate of 
perfe<9: reft. 

Of the Dutch failors^ who wintered at Spitz- 
bergen, the greater part of thofe who remained 
fhut up in thdr wooden hut perifhed j while thofe 
who went out into the open air, and who em- 
ployed themfelves in hunting and other exercifes, 
furvived.and fuffered very little inconvenience. 

20. On the other hand, when a man is ex- 
pofed to a very high tefinperature, he experiences 
an uneafinefs of another kind : refpiration, in con* 
fequence of inhaling air very much rarefied, is 
rendered more difficult and lefs energetic j he ex- 
periences a tendency to repofe ; his appetite de- 
creafes ; he eats little and drinks more ; the fkin, 
dire6lly flimulated by the contadl of the warm air, 
becomes relaxed ; a fecretion of fweat takes place 
in greater abundance ; the evaporation produced 
at the furface of the body carries with it a great 
quantity of heat; and the individual is thus 
maintained at his ufual temperature : but if the 
heat of the air continues or increafes, in an ex- 
celfive proportion, he neceffarily finks under it, 
and becomes exhaufl:ed, not only by the employ- 
8 ment' 


ment of the force neceflary to free him from the 
excefs of the heat, but alfo by the real lofs of 
the juices carried off by an abundant perfpiration. 

To whatever natural temperature, therefore, a 
man may be expofed, the heat of his blood, when 
in a fliate of health, always remains at 38 or 40 
degrees of the centigrade thermometer (104° of 

Every time that the atmofpheric air takes from 
him, or fupplies him with caloric in excefs, the 
whole of the organization makes an effort to re- 
turn to and maintain itfelf at the habitual tempe- 
rature. In either cafe, the vital power is at firil 
exalted ; and it may be faid that the abdraftion 
or addition of a certain quantity of heat is always 
in the commencement a ftimulant to the organi- 

When the ftimul:.::n,^ a61ion of the heat or 
cold is too violent, or continues too long, it 
waRes the flrength and leaves the body in a 
ftate of feeblenefs or exhaufiion more or lefs 

When a body ftrongly heated is applied to any 
organ, a great part of the heat communicated to 
it fuddenly deftroys its texture j the reft is con- 
veyed to a greater depth, and a61s as a very ac- 
tive irritant. The impreffion received is tranf- 
miited by the nerves to the brain ; this organ in- 
ilantly reads on the afFefted part, as well as on 



the whole, of the organization, and produces that 
mode of adion which conftitutes the fenfation of 

When aduftion takes place in a paKied limb, 
the impreffioii is not tranfmitted^ becaufe the 
nerves of the organic life are deftroyed, and the 
fenfation of pain does not enfue ; but the other 
phaenomena are the-fame, though flower in their 
progrefs, and take place by means of the nerves 
which accompany the veflels. 

When a part is inftantaneoufly diforganized by 
a very great degree of heat, fuch as the applica- 
tion of a piece of iron brought to a white heat, the 
fenfation is duller and lefs painful : it fometimes 
happens that a patient, when a nerve has been 
deftroyed in this manner, thinks he experienced 
a very intenfe degree of cold. 

When a part has been diforganized by heat, 
thofe in the neighbourhood enter into a new mode 
of adlion. (See Phlegmafia.) The dead part de- 
taches itfelf ; and there remains an excoriation or 
a wound, which cicatrifcs in the ufual manner. 

ai. Light exercifes a very liriking a£^ion oti 
organized beings. Every living body, when ex- _ 
pofed to light, expands in a vigorous manner, and 
afllimes a darker tint; the colour, fmell, and 
tafte of the different produces of fecretion have a 
more ftriking charader : while beings which grow 

VOL. in. P up 


up in the (hade remain pale, ftunted, and aque- 
ous, and exhibit all the iyrnptoms of feeble and 
languilning life. 

The long continued acTtion of light and heat 
on the human fldn, in the mod loulhern coun- 
tries, renders it brown, and caufes its mucous 
membrane to affume a black colour. This colo- 
ration may have been heightened and propagated 
by generation, and may thus have produced, a 
variation in the human fpecies. 

2 2. The eleclric fluid, univerfally diffufed 
throughout the atmofphere, feems to have a great 
influence on the organization. Every perfon may 
have obferved, during ftormy weather, efpecially 
when the atmofphere is damp and warm, that the 
body fometimes feems to be opprefied, without 
force and without energy, and that the limbs are 
as if exhaufled with fatigue. This difpolition does 
not correfpond exactly with the fiate of the ther- 
mometer and of the hygrometer ; but it might 
perhaps be marked by a proper ele61rometer. It 
would appear, that in this cafe the damp air, 
which is a very good conda(51or of the ele<Elric 
fluid, draws off that fluid from living bodies, 
and on this account they remain enervated and 
wirhout reaction. 

23. Every organized body^, which is continii- 

5 a'Jy 


ally Immerfed in an atmofphere latarated with 
water in a ftate of vapour, becomes pale, relaxed, 
and without energy *. This is the cafe with forne 
fpecies of animals, fuch as fheep ; with vege- 
tab1'-\ in general ; and in particular with herba- 
ceous plants. 

34. Independently of fubftances univerfally 
diffufed throughout the atmofphere, to the influ- 
ence of which man is continually fubjedled, there 
are a great many others, with which he is inti- 
mately conneded by nutrition, by his artificial 
w^ants, and by his health ; or with which he is ac- 
cidentally brought into contadl. All thefe fnb- 
flances exercife on the organization an action, a 
careful cbfervation of which is of fome import- 

When foreic:n fubflances are in immediate 
conta6l with our organs, the following phseno- 
mena are, in general, obferved : 

ill. Thefe fubuances tend to combine with the 
living body in the ratio of their chemical afnnity; 
and thus make an effort to defi:roy the organic 
ftrufture of the part to which they are applied. 

* The afFedlion produced by the long coiitinued Influence of 
dampnefs, added to want of food, or to food of a bad quality, 
is diftinguifhed in man by the name of the fcurvy ; in fiieep and 
plants it is called the roi j in fwine the hfrofy^ &c« 

p 2 ad. 


2d. On the other hand, the living organs 
tend to decompofe or to digeji thefe fubflances, 
and to reduce them to a ftate which renders 
them fufceptible of entering into the circulation, 
and of thus ferving to repair the nutritive fluids. 
The organs alfo make a continual effort to expel 
all thofe fubflances which are improper for nutri- 

3d. In the laft place, the foreign fubflances, by 
their contad: with the organs, produce an imprel- 
lion which may be tranfmitted by the nerves to 
the brain ; and the refult is a change in the ge- 
neral flate, which zoxv^\i\x\&'ifenfation. 

When a foreign fubftance tends to unite itfelf 
to the organic parts, with a force greater than 
that with which the organs are endowed to re- 
flft, the refult is a real chemical combination. 
This combination does not completely take 
place, except when the nerves of the part have 
been entirely diforganized ; but if vitality ilill 
cxercifes an a6lion, this chemical phacnomenon is 
more or lefs modified. 

When the foreign body, applied to an organ, 
poffeffes a great force of affinity, the phaeno- 
menon has a perfe6l refemblance to that which 
refults from the a6iion of heat : the nerves are 
fpeedily deflroyed, and the chemical combination 
is then efle^ted to faturation. Such is the a6lion of 
cauftic alkalies, of alkaline earths, of concentrated 



mineral acids, of feme oxides, and of feveral 
faline fubftances. 

Thefe different fubflances are employed in far- 
gery to defiiroy difeafed parts, or to open caute- 
ries. Thus a bit of caufiiic pot-aflT, applied to a 
portion of tfee fkin, has a ftrong tendency to 
attract all its humidity ; and the organ is foon 
dried up and deftroyed. The alkaline fubftance 
then combines with the fat fubflances, and the 
refult is a fort of foap ; the living parts in the 
neighbourhood of the fear, and which have been 
irritated, enter into a new aclion ; the fear de- 
taches itfelf, and a common wound remains. 

Thefe different mineral fubftances, introduced 
into the alimentary pafTages, deftroy in like man- 
ner the parts with which they come into contad, 
and produce accidents which often prove mortal. 
In fuch cafes the wound made in the gaflric or- 
gans, and the fubfequent accidents to which it 
gives rife, are an evident caufe of the perfon's death. 
Thefe phenomena are altogether different from 
thofe obferved in cafes of poiloning j after whicji 
no trace of alteration is obferved in the parts which 
received the poifon. 

When the vital power offers a partial refinance to 
the chemical action the phsenomenon is modified. 
Thus, in a man whofe organization is confider- 
ably weakened, a limb affected by a wound, or 
exhauHed by long fuppuration, prefents but a 

p 3 feeble 


feeble refiftance to ihc force of chemical affinity. 
The gangrene which, in fome cafes, enfues is the 
refult of the chennical adion of heat, of moiaure, 
and of atmofpheric air, on the hmb half dead, 
which indeed exhibits all the 'phenomena of pu~ 
trefadion, raoditied by a remainder of life. 

In the laft place, if the foreign body exercifcs 
only a very feeble adlion on the organs, it may 
remain in contacl with them, and yet produce 
no accident. Thus, a mulket ball remains with- 
out any inconvenience amidft parts, the aftion of 
which it neither confines nor impedes. 

2,5. When the fubflances brought into contaft 
with the organs are fafceptible of an eafv decom- 
poiition, as is the cafe with all thofe which arife 
from organized bodies, or which form a part of 
them, they are then digeited by thefe organs, and 
reduced to fimpler compounds, fufceptible of be- 
ing taken up by the abforbing veilels, and con- 
veyed into the torrent of the circulation to form 
part of the nutritive fluid : the relidue is thrown 
out by different paflages. 

Thefe fubftances are digeflied not only at the 
furface of the alimentary paiTages, but alfo by all 
the organs. Thus the produ6l of the fccretions 
depofited in the fplanchnic and articular cavities, 
the purulent colle6iions, fmguinolent efFufions, 
lumefaflions^ concretions^ and urinary or bilious 



calcuHi may be digejled\ and being then reduced 
to their iirft principles they enter into the circa- 

The digeftive power of the different parts does 
not depend on the diflblving action of the animal 
fluids. This diftipd a6lion is exceedingly weak, 
even in the digeflive juices. But thefe fubftances 
are digefted by a force peculiar to vitality, and 
which has no relemblance to chemical affinity. 

If ofleous concretions, calculous tophi, "and the 
different kinds of calculi, are evidently digefted 
by the a6liou of the organs, under certain circum- 
ftances, there can be no doubt that the various 
liquids effufed are alfo digelled before they enter 
into circulation. It is, indeed, hardly to be be- 
lieved, that the pus, urine, bile, &c. are taken 
up without alteration by the abforbing veffels, and 
thus conveyed into the blood. Befides, this hy- 
pothefis is deflroyed by the ingenious experiments 
of Dupuytren. This anatomifi: afcertained that 
the injedion of thefe fubflances into the veins 
always produces accidents more or lefs dangerous, 
and very often fudden death. It may alfo be 
added, that chemifts have never found in the 
blood any of thofe foreign fubftances, which were 
fuppofed to be fufceptible of pafiing into it with. 
fo much facility. 

When a foreign body, depofited in an organ, 
cannot be digefted in it, and if it form an incon- 

p 4 venient 


venient ftimulant, it gives rife to the development 
of a phlegmon, which fuppurates ; and the fo- 
reign body is then thrown out by the aperture 
along with the pus. 

That the organs may be able to exercife on 
the different foreign fubftances that force which 
is neceflary to digefl; or to expel them, they muft 
enter into a new mode of a6:ion. This change of 
ftate in the organs is produced by the prefence of 
the.foreign body, and by the impreffion of contadl 
which it exercifes on the nerves of the part with 
which it is in relation. 

a5. After birth, the firfl: fenfations which the 
organs experience are q\w ays pa hrful ; and children 
give external figns of them by cries : they either 
cry or feem indifferent. But the organs, by 
their gradual expanfion, acquire improvement, 
and the individual is at length able to appreciate 
a change of ftatc which takes place in any part, 
though it be very trifling, and though it does not 
interrupt the natural order. 

When this change of ftate tends to facilitate 
the execution of the different fun6lions, and thus 
contributes to the completion of life, \.h& fenfation 
is agreeable. 

The rea^lion, casteris paribus, of the centre of 
the nerves, when an impreflion is received, is di- 
recled in particular to the part which has been 

touched ; 


touched ; and if this part has experienced an al- 
teration in its organic ftrudlure, the impreffion is 
continued, and always produces a painful fenfa- 

The impreffion made on an organ is the more 
lively, as the nerves are more immediately ex- 
pofed to the contacl of the foreign bodies, and 
as their pulpy part prefents a greater development 
at its termination. 

The fe.nfation which refults from the impref- 
fion made on an organ is the ftropger, as its 
nerves proceed more dire61Iy to the centre of the 
cerebral organ (the brain). Under this point of 
view, the parts .leafi: proper for producing fenfa- 
tions are thofe, the nerves of which proceed to 
the trilplancbnio ; and thofe mod conveniently 
difpofed for producing lively and fpeedy fenfa- 
tions are the fyllems of organic life, and even 
thofe of relative Hfe, or the organs of the fenfes, 
the nerves of which terminate directly at the en- 
cephalon. . 

A flight impreffion made on any part, the nerves 
of which correfpond with the trifplanchnic, pro- 
duces a change of ftate more or lefs ftriking, but 
does not occafion any fenfation. When this 
change of ftate is continued or increafed, and 
if it , deranges the natural order of the organic 
fyllem^ of which it forms a part, the derangement 
becomes a new impreffion. This impreffion is 



propagated by the nerves of the organic fydem 
as far as the cerebral centre, the reaction of which 
on this fyflem confiitutes lenfation. 

Thus, the impreffion made on the macous 
membrane of the genito-iirinary pafri5ges, by the 
conta6l of the fecretion of a blenorrhagia, or on 
that of the aerian paf!ages, by the contadl of cold, 
damp air, produces very often no fenfation. A 
very ftriking new^ mode of adlion, however, is 
developed in thefe parts, the membranes of which 
fwell up and fecrete a new produ61. Thefe 
changes foon become a new impreffion, and the 
refult is a painful fenfation, which takes iplace in 
confequence of a derangement in the fundions of 
the genito-urinary and the relpiratory organs. 

After an imprefHon made on a point of the 
vifcera of the abdomen, there often takes place 
a new mode of aftion, which gradually increafes, 
v.'ith an alteration in the organic fi:ru(5iure of the 
part, but without producing Jen/a/ ion. Thefe dif- 
orders are not felt except when of contidcrable 
extent, and when they produce flriking derange- 
ments in the funcflion of the fyftem of digeftion. 
This is what takes place in all the flow phlegma- 
lise, commonly called ohJlruBlons. 

27. A foreign body, to produce a new mode of 
a'5lion in the whole organization, does not need 
to be abforbedj and to be conveyed to all the 



parts, to occaiion in them the different diforders 
which refult from its prefence. Nothing is ne- 
ceflary but that there (hould be an impreffion by 
contaft on' the nerve^ and that this impreiiion 
fhould be tranfmitted to tlie nervous centre. 

All the inllances quoted, in fiipport of the opi- 
nion that morbiiic fubfiances are abforbed, only 
prove that they may be fo, but do not prove that 
they really are Cibforbcd; while, in many cafes, it 
is evident that nothing is abforbed, and yet the 
fame effects have been produced. Thus, when 
the variolous npatter has been introduced below 
the epidermis of the hand, there come on, in the 
courfe of a few dajs, rednefs, pain, heat, and 
Iweliing in the part which has been pun(5iured j 
the pain is continued along the arm, with a red- 
difh ftreak, which feems to mark the progrefs of 
the virus ; and a fwelhng takes place in the glands 
of the arm-pit. At the end of fome days the 
individual experiences a pain in. the head, fever, 
and a general derangement, which feems to indi- 
cate that the i^ifedtion has been univerfal, and that 
the virus has been conveyed, as is faid^ into the 
whole mafs of the blood. 

But an evident proof that this progrefs of the 
virus is not neceffiiry for the production of all 
this feries of phaenoraena is, that the lame fym- 
ptoms are exhibited when a thorn is introduced 
into the finger, though it is very certain, in this 



cafe, that the thorn has not been abforbed. The 
prefence of the thorn, under the epidermis, is not 
even necelTary to occafion all thele accidents ; 
they might be produced by the prick alone. Thus 
a woman, whofe fingers are very clean, pricks 
berfelf with a needle, which is alfo very clean ; 
and the confequence fometimes is the fame feries 
of phsenomena. Nothing indeed is neceffiiry but 
the picky it is it alone which produces all thefe 

It is well known that many perfons expe- 
rience violent colics, and are attacked by diar- 
rhoea, when expofed to cold in the feet, la 
this cafe, the impreffion of the cold reprefents the 
prick ; and ftill an effedl is produced on a diftant 
part, though nothing has been ablbrbe^'. 

After a blow or a fall, &c. there often come 
on fevere diforders in organs very far diftant 
from thofe which have been injured. 

Hence it is evident^ that the ablbrption of fo- 
reign fubftances, virus, &c. and the conveyance 
of them into the blood, to produce different dif- 
eafes, is an hypothelis fupported by no certain 
proofs ; which is contrary to the general laws of 
organization, and which, inftead of throwing light 
on thefe fadts, tends rather to obfcure them. 
The continual application of fo great an error in 
the treatment of difeafes cannot fail of being 
often dangerous. 



The Impreffion of certain foreign bodies is of 
fach a nature, that the rea6lIon is always effected 
on the fame organ, whatever be the part where 
they have been apphed. Thus cantharides al- 
ways produce a rea£lion on the genito-urinary 
or2:ans : fubftances of this kind are faid to have a 
Jpecific a6fion. 
' Some fubftances caufe an increafe of general 
ac^lion, without producing derangement in any 
organ in particular, as is the cafe with opiumi and 
alcoholic beverages. When this intoxicating ac- 
tion has been long continued, or powerfully excited, 
the organs experience great weaknefs, and the 
exhausted individuals tumble down or fall afleep. 

la the lafl: place, fo'Vne fubftances occafion a 
fudden derangement, or a general diforder, which 
produces inftant death, after a few convulfions, 
without leaving any traces of alteration in the 
part which received the impreffion. Of this kind 
are thofe poifons called narcotic, the afphyxiating 
gafes, and the poifons of feme animals. 

a8. Thefe obfervations on the phsenomena of life 
give rife to feveral important confiderations, which 
ought always to be kept in view. 

Thus, the refult of every impreffion made on 
a part provided with nerves, is a change of ftate, 
or new mode of adlion, in one or more organs, or 
in the whole of the organization. 

7 Con- 


Confcioufnefs of a chonse of (iaie, which has 
fuddenly taken place in the whole of the organi- 
zation^ conftitntes fc-nfation. 

The irnpreiiion made on the organs v/hich re- 
ceive their nerves only from the trifplanchnic, 
occalions in thcfe parts a How aheration, which 
very often produces no dlrcLl j'ciifalion. 

The aheration of thefe organs may then be- 
come the caufe of fenfation, when it is llrong 
enough to didorb the organic fyiiera of which it 
forms a part. 

The changes which take place fuddenly in thofe 
lyfiems of organs, the nerves of which proceed 
dire611y to the encephalonj or to its prolongatioB, 
slways produce fenfations. 

The fenfations are painful when the new mode 
of adlion tends to difturb the jnatural order of 
the functions ; and they are agreeable when it 
contributes to caafe them to' be performed witb 
more force and energy. 


[ 223 ] 


29. The organs of tlie fenles almoil all receive 
their nerves from the encepbalorij by a very fhurt 
paflage. Thefe nerves exhibit, at their termina- 
tion, a peculiar ftrudlure, which renders them fit 
for receiving the impreffion of every thing 
around them, or which ftrikes them. By this dif- 
poiition, the organs of the fenfes bring man into 
relation with every thing without him, by making 
him experience very nrong fen^ations. The func- 
tion of thefe organs will be the fabject of the fol- 
lowing obfervations. 

30. Touching, The fenfe of touching rciides 
in the pulpy termination of the nerves of the Ikin. 

The cutaneous lyflem is compofed of the dermis 

and the epidermis. The dermis, or fldn properly 

fo called (cor'mm), is a thick membrane, of a clofe 

and elaftic texture. The numerous nerves which 

proceed thither traverfe this m.embrane, and tbrm 

at its furface a pulpy expaniion difficult to be 

obferved. This nervous termination is accom- 

. panied by a reticular tifTue of fanguiferous vetTels, 

exceedingly fine, and the whole is covered by a 

mucous ftratum or coating, in which the colour of 

the fliin refides. 



The epidermis is a thin dry pellicle, which 
feems to be inorganic : it appears to be formed by 
the jundion of fmall imbricated laminae. 

The difpofition of the cutaneous fyftem is ex- 
ceedingly well calculated to maintain the nerves 
of touching in a proper ftate of moiflure and pli- 
ability. The epidermis ferves to fecure thefe 
nerves from the immediate contact of external 

The whole furface of the body poflefles the 
tadlile faculty, and may receive the impreflion re-~ 
fulting from the mafs, from the volume, and even 
from the figure of the refilling bodies, as well as 
from their thermometric and hygrometric ftate ; 
but it is chiefly by means of the hand, and by long 
and continued exercife, that man is enabled to 
appreciate properly thefe pbyfical qualities of 

The admirable difpofition of this organ allows 
it to yield to \heir figures j to touch them in all 
their points ; to pafs over their whole furface with 
great facility ; to lay hold of them, to prefs 
them, and to raife them up ; and thus to bring 
itfelf into relation with them in the moft intimate _ 

The hand of man, which may be exclufively 
employed in the contadl of bodies, is fufceptible of 
acquiring, by long habit, an inconceivable degree 
of perfedion and of delicacy, as has been obferved 



In fome blind perfons, who by the touch could 
diftinguifh even colours. 

The hand, confidered as an organ not employed 
for^walking, is an attribute peculiar to the human 
fpccies; and it has juftly been confidered as the 
principal inftrument of his fuperiority over ani- 

ThQ organ of touching is that alone which 
brings us into immediate relation with the whole 
of the furrounding bodies. The other organs of 
the fenfes only receive the impreffion of conta6i, 
which refults from fome of their particular proper- 
ties. Thefe organs can be improved and become 
ufeful to us, only io far as Ihey begin to be exer- 
eifed in concurrence with the organ of touching. 

31. Taji'ing, The fenfe of tafting is only a 
more;exqui{ite organ of touching, exercifed by the 
membrane which envelops the mufcular body of 
the tongue, and by that which covers the infide of 
the mouth. 

Thefe parts have the faculty of perceiving the 
impreffion made on them by fome particular fub- 
fianccs, and efpecially by thofe fulceptible of af- 
fuming the grcatefi: degree of divifibility, by dif- 
folving in the faliva. 

It is chiefly the upper part of the tongue, and 
the lips, that poflefs the faculty of tailing in the 
higheft degree ; bccaufe they are the firft which 

VOL. II f. Q^ prcfent 

prefent themfelves ta receive the favoury Tub* 
ilances, and becaufe^ tbey are more habitually exi 
ercifed in that operation. 

The part of the tongue, on which the fenfe of 
tafting is more particularly exercifed, exhibits a 
peculiar ftrufbure ; it is covered with papillae of 
different forms and fizes, which, when in con- 
ta6l with fapid bodiesj enter into a kind of erec^ 

32. Smelling. The organ of fmelling is com- 
pofcd of the membrane that covers the interior 
part of the noftrils. 

This membrane has the property of receiving 
the impreffion, made on it by the contact of cer- 
tain molecule of matter, in a ilate of great te- 

Before a fubiiance can afFe^i: the olfaiclory mem- 
brane, it muft be in the ftate of gas, or fufficiently 
divided to keep itfelf in folution or in fufpenfion 
in-an aeriform fuhftance. FJence it may be feen, 
that all bodies are fufceptibleof ailuming that ftate 
which i« proper for affecting the organ of fmell ; 
and that all fubflances,. very much divided, may 
become odorous bodies. 

; Bodies are not odorous in confequence of any- 
peculiar property inherent in their nature, but 
only by the common faculty of affecting the organ 
©f fmell ; foihai certain bodies are odorous \X> one 

-■ ^ and 


and not to another. A great number of fub- 
Itances are odorous to the dog and the Twine ; but 
are not Co to man. 

r Though, in general, a very fraall number of 
fubftances only are odorous, the greater part of 
bodies afFedl the fenfe of fmelling, when in a ftate 
of extreme divifion, and conveyed to the oI'a(5tory 
nerve in fufficient quantity and for a certain time. 
It even appears that to fome animals, fuch as dogsj 
every body whatever is odorous. The power of 
fmelling appears, in general, to be in the ratio of 
the extent of the nafal fofTae. 
• When fubftances produce analogous tenfation? 
in the olfactory organ, they are faid to have the 
fame odour; and fubftances which exhibit very 
little phyfical, chemical, or organic relation, very 
often afFeiSl the olfadlory organ in the fame man- 
ner; Co that it is difficult to determine whether 
the impreffion produced on the olfacSlory mem- 
brane, by the moleculae of the odorous bodies, de- 
pends on the form of thefe moleculee, or on their 
chemical compofition. 

The azotic and oxygen gas of which the atmo- 
fphere is effentially compofed, and which are in 
continual contadl with the olfadlory membrane, 
make no impreiTion upon it ; but thefe gafes ferve 
as an excipient to odorous fubftances, which they 
hold in folution or in fufpenfion. 

Atmofpheric air conveys odorous, fubftances, to. 
Q^a the 

'lis ■ -iriTAL FUNCTIONS. 

the noflrils, while it pafles through them to pro- 
ceed to the lungs duriiig refpiration; fo that thofe 
defirous of fmelling with more force, muft fhut 
the mouth and make a ftrong infpiration through 
the noftrils. 

The odorous moleculas, thus depolited on the 
olfa61ory organ, make en it an impreffion of con- 
ta61, which is propagated as far as the brain, and 
determines that organ to produce a movement of 
Efcneral and inftantaneous readiion, which confii- 
tutes the fenlation of fmell. This movement of 
reaQion is fomctimes fo violent that, in fome wo- 
men of exceffive fenfibility, it occafions vertigo or 

The organ of fmell, like all the other organs, is 
flrengthened by exercife, and is weakened by too 
fbrong or too frequent adiion. 
' A man who is habitually in the midft of certain 
odours, • even exceedingly ftrong, becomes at 
length infenfible to their aclion ; but he who is 
frequently in relation with odorous bodies of a 
different nature, and who continually Iludies their 
a6iion, may acquire the faculty of fmelling in an 
emJnent degree, and perceive odours exceedingly 

The membrane which lines the finufes is thin 
and fmooth ; and' its ft ru61ure has no refemblance 
to that which lines the natal fotiee : it is therefore 
probable that it does not lerve for perceiving 



odours. The ufe of the finuffes feems to be, to re- 
tain a larger quantity of air. 

33. Seeing, The vifual fyftem confiUs efTcn- 
tially of a very thin membrane, which lines the 
bottom of the eye, and which has the property of 
perceiving the imprefiion made on it by the con- 
tadl of the light, either direct or rcfleded, from 
external bodies, and refracted on it by the tranf- 
parent fluids of the eye. 

The eye is compofed of three tranfparent bodies 
of different denflties, placed one within the other j 
and each contained in a thin pclhcle, which per-? 
ceives the conta6l of the lighl, 

This apparatus is enclofed in a double covering;, 
thick and blackifh in the infide, having in the fore- 
part a contra6iile aperture, before which is placed 
a cartilaginous and tranfparent fegment of a 

This dioptric arrangement has fome refemblance 
to that of an achromatic telefcope, or of a camera 
obfcura. It feems to have acquired all its develop- 
ment at the period of birth. 

In the fundlion ot the vifual organ, if the lumi- 
nous rays which proceed diredtly from the fun 
reach the eye, a bundle of them, equal in fize to 
the aperture of the pupil, penetrates into it. This 
|:mndle is refraded by the humours of the eye; 

<^3 i^nd 


and the parallel rays, which compofe it, approach- 
ing each other, from the perpendicular diredion, 
converge on the retina. 

The contac^l of this luminous point produces, 
on the retina, a ftrong impi^effion, which is propa- 
gated to the brain, and occations a fudden and in- 
Hantaneous change of ftate. This change of Hate 
excites in the eye a movement of rea61ion ; the 
iris expands, the aperture of the pupil is contra<5l- 
ed, and the eye-lids approach each other. Thefc 
parts oppofe, in this manner, the introduction of 
the luminous rays, the impreffion of which pro- 
duces a painful and vague fenfation. 

The luminous rays which fall on bodies are re- 
flected from every part of them in a diverging 
form, and the angle of their refie6iion is equal to 
that of their incidience. 

To have a proper idea of the aSi of vifion, we 
mufl fuppofe that a cone of light proceeds from 
each point of an illuminated body, and that all 
thefe luminous cones are propagated, in a diverg- 
ing form, without being confounded. 

The light proceeding from a body which falls 
on the apefture of the pupil, is compofed of por- 
tions of all thefe luminous cones, which have their 
fummits in different points of the illuminated 
body. But the whole of thefe portions of lumi- 
nous cones form another inverted cone^ the bafe 



jof which Is meafurcd by the fize cf the. bady, aad 
its truncated fummit is equal to the aperture of 
the pupil. 

To conceive the progrefs of reflected and re- 
fra(5ied light on the retina, it will be proper to fol- 
low the courfc of a luminoLis cone, procfeeding 
from one lingle point of a body ; and what has 
been faid of this cone of light may afterwards be 
applied to tKofe which proceed from all the other 
illuminated points. 

A luminous cone^, which proceeds, from any 
point of an illuminated objec?!, reaches the eye in 
a diverging form. The rays of this cone, which 
fall upon the tranfparent cornea^ pafs through it, 
and are refradled from tlie perpendicular dirediou, 
in the ratio of the denlity and convexity of that 
cartilage. Thefe rays continue to be refradled in 
pafling through the aqueous humour, and reach 
the iris, which affords a paflagc to a quantity..of 
light, meafured by the aperture of the pupil: the 
reft are refle6ied. The rays of the luminous cone, 
which pafs through the aperture of the pupil, foon 
reach the lens of the cryftalline humour, ^nd are 
more ftrongly refraded in the ratio of its convexi- 
ty and of its denfity, which is greater than that of 
the other humours. Thefe rays afterwards pafs 
through the vitreous humour, and experience a 
third mode of refradlion, in the ratio of the denlity 
of the vitreous body. Thi's rcfradiion then is 

0^4 weaker 


weaker than that produced by the cryftalHne hu- 
mour, but ftronger than that occafioned by the 
aqueous : fo that the luminous rays, in pafiing 
through the three tranfparent bodies of the eye, 
are differently refracled, in a fort of zig-zag form. 
By thcfe means, the rays which in traverfing the 
aqueous humour began to be decompofed and to 
be feparated, as in the prifm, are again confounded 
or mixed in paffing through the cryllalline hu- 
mour; and the decompoiition produced by the 
cryftalhne is dcftroyed by the vitreous humour. 
In confequence of this arrangement, the rays tra- 
verfc the eye without experiencing any alteration, 
retain all their purity, and are never tinged with 
the prifmatic colours. 

To avoid coloration with the prifmatic colours 
in telefcopes, feveral glaiies of different denfities 
are applied to each other; and this difpolition, 
analogous to that of the eye, is diilinguiOied by 
the nameof^r^^'/^row^^'i^. 

In the lall place, all the rays of the luminous 
cone, continuing to be refradiied through the vi- 
treous body, unite in one point, which iirikes the 
retina; and it may therefore be faid that the light, 
which proceeds from an illuminated point of any 
objc6l:, proceeds to the retina, forming two cones 
oppofed to each other by their bafes. 

What has been here faid, in regard to the pro- 
grefs of this cone, proceeding from one illumi- 


liated point of an object, may be applied to thofc 
which proceed from all the other illuminated 
points of that body, and which alfo proceed to the' 
eye. All thefe cones of light traverfe the eye in 
different direfllons, crofs each other without being; 
confounded, and converge on different points of 
the retina, preferving the fame refpe<5tive polition,- 
which they had when they proceeded from the 
illuminated objed. All thefe luminous points de- 
fcribe, in this manner, the image of the objedl oil 
a fmall fpace of the retina, producing on that 
nervous membrane an impreffion, more or leis 
lively, and of greater or lefs extent. The rays 
which fall in a dire6lion perpendicular to the axis 
of the eye, are propagated in a (Iraight line, and 
experience no refraction. 

The rays which diverge and fall on the choroid, 
are abforbed by ihe black coating of that mqm-» 

As the luminous cone, which proceeds from 
each point of an illuminated objefl, converges on 
the retina in the direction of its axis, it mufl occu- 
py on that membrane a pofition, the reverfe of 
that which it had in the obje6l, and the image is 
confequently inverted j but to fee obje6ls in the 
diredion of the axis of the luminous cones pro- 
ceeding from them, is the difpofition proper for 
making them appear to us upright. Befides, we 



have not the faculty of perceiving the top or th^ 
bottom, the right or the left, of our retina. 
. When the light which falls on the furfacfe of a 
body is refleded entirely, it produces a deter- 
minate impreffion (white) ; but the impreffioq 
changes when the body decompofes the light, 
abforbs one part of its rays, and refle6ls the other. 
. Light is decompofed into feven rays, which, 
being refledled in all the combinations poffible to 
|brm the di^rent images, produce on the retina 
an indefinite feries of particular impreOlons. 
; Of the points which refled the light, thofe 
which abforb it entirely produce a negative fenfa- 
tion (black). 

, It is not as an image painted on the retina th^t vi^e 
have a fenfation of obje6^s ; for this image would 
be of no utility. Another eye would be neceflary 
to look at it. But it is becaufe the luminous rays, 
in delineating that image, produce on the retina 
an impreffion of contadl, more or lefs lively, and 
of greater or lefs extent. 

. The imprefiion made on the retina, by the con- 
tact of the light receded from objeds, produces 
at firft a very uncertain fenfation: it announces 
.that the bodies exifi and are different^ tince they 
produce variable impreffions; but thefe impreffions 
give no idea of th^ form, fize, or diftance of thef 

. Though bodies of the fame form produce fimi- 



tar fen rations, the impreflion produced by the re- 
fiedion of the light could never have ferved for 
determining thefe forms; and if men had not beeri 
endowed with the faculty of touching, they could 
nevei' have been able to tell whether bodies vverds 
round or fquare, according to the ideas which we 
affix to thefe words: they would only have faid, the 
Jx)dies, the refledted light of which produces the 
ienfations A B. 

A perfon born blind, when cured by couching 
for the cataract, does not all at once enjoy the fa- 
culty of feeing the light. When fhown the cat 
which he has been accuftomed to carefs, he does 
not know what it is. When made to touch it, he 
immediately exclaims, " it is my cat, I fhail no 
longer require the aid of touching to diflinguiili 
it." But this contact is abfolutely neceiTary, and 
he might continue to touch it without feeing it, 
and to view it without touching it, and confider it 
as two different objects. 

The imprdlion produced by the light refle6led 
from any body cannot enable a perfon to judge of 
its dillance. The man born blind, who was re- 
ftored to fight by Chefelden *, imagined that all 
bodies fhown to him were in contadt with his eye ; 
becaufe he had been accuftomed to receive imprel^ 
iions of touching by immediate contadt, and not 
by the intervention of a refledled fiuid. 

* Philofophical Tranfaftions for ijaS. 



Since light refledled by a body cannot enable us 
to judge of its diftance. rt can as little give us any 
idea of its volume: the fize of bodies, indeed, 
forms the fonrce ofthemofl frequent optic ill u- 
lions which we experience, and which we often 
cannot prevent, though we previoully know that 
they will take place. 

If an obje6t, completely detached from others, 
be viewed through a hole, the perfon who looks at 
it has no means to enable him to judge of its 
magnitude and diftance. He, however, forms an 
opinion of thefe two relations; and this opinion, 
in regard to diftance, is alv/ays founded on the 
manner in which the object is illuminated; and, 
in regard to fize, on a comparifon of it with other 
bodies the fize of which is known. 

Bodies produce on the eye a flronger impref- 
fion, according to the greater quantity of light re-, 
ficfled from them. ( A fmall body, not much illu- 
minated and fituated at a fmall diftance from the 
eye, may be confounded with another of the fame 
form, which fubtending the fame angle may be 
firongly illuminated, of a very large fize, and 
placed at a great diftance. Hence the eye alone 
affords no means to enable us to form a judg- 
ment of the diftance of an infulated body, placed in 
infinite fpace, and with which we are unacquaint- 
ed. It, however, cannot be faid that in all thefe 
cafes the fenfe of fight leads us into an error, but 



Only that it leaves us in uncertainty. This organ 
cannot be improved and acquire the faculties pe- 
culiar to it unlefs exercifed in conjun(Slion with 
the organs of touching. 

Were the eye merely a machine, there would be 
only one point of fight out of which vilion would 
ceafe ; but it is a living organ in all its parts, 
which accommodates itfelf to a feries of diftances, 
of greater or lefs extent ; which becomes longer or 
Shorter ; renders the cornea flat or convex, pullies 
it backwards or forwards, &c. ; and the bell eye is 
that which pofleffes, in the higheft degree, the fa- 
culty of varying its forms in fuch a manner, as 
always to unite; in the fame point of the retina the 
moft diverging rays, and thofe which approach 
nearell to a flate of paralielifm. 

When wc look very near at an illuminated ob- 
je(9;, the iris extends and fends back the mofl di- 
vergent rays. On the other hand, uhen we look 
at a diflant object not much illuminated, tb.e iris 
refumes its former flate ^ the pupil dilates, and re- 
ceives a luminous cone much broader, but which is 
compofed of rarer light and of rays more diver- 

The quantity of light is diminifhed by propaga- 
tion, in the dire6l ratio of the fquare of the di- 

Though we look with two organs we do noi {gq 
two obje6b, becaufe the luminous rays falling on 



both the eyes in the fame diredlion, converge at 
the fame time on both the retinas, and produce 
two impreffions, perfe(9:ly fimilar, which are con- 
founded. But, if th'fe difpofition be deranged ; if 
the two eyes be not direded towards the objedl in 
the fame axis ; if one be turned to one fide, or if a 
perfdn voluntarily places them in a fquinting poli- 
tion, obje6^s are feen double. In this cafe, it is 
. obferved that one of the images feems always to be 
more illuminated or nearer than the other, which 
then produces two fenfations. 

To render vifion diftin^t, the luminous cones re^ 
fracfted by the tranfparent fluids of the eye mufl: 
reach the retina at the moment of their converg- 
ing; for if they converge beyond or on this lide 
of that membrane, the vifion is neceflarily con* 
fuied. This precifion of convergency on the re- 
tina is the refult of the degree of the convexity of 
the cornea, of the refra61ing power of the hu- 
raours of the eye, and of the diftance between the 
cornea and the retina. When the natural proper^ 
tions do not exifi, and when the mobility of the eye 
cannot refiore them, the point of fight is neceflirily 
changed, as in the cafe of the myopes and pref^ 

The iifual point of fight enables a perfon tt^^' 
read middle fized print difi.inclly at the diftanpi^- 
of eight inches. , 

Objedls to be diftin6lly fcen mull be placed at 

a diftance 


a diflance proportioned to^heir lize: thus to fee a 

painting, one mull remove from it to a diftance 

double to its fize. 

■ Some perfons, to fee diftin(5ily, do not'turn the 

axes of both eyes towards the objed in an equal 

manner ; this produces a deformity of fight called 

fquinting. (Strabiftnus), 

. For the moll part, one of the eyes only is not 

direded towards : the objedl ; but Ibmetimes this is 

the cafe with both. ■ 

Children, who begin to move their eyes about at 
random, before they look at any thing with preci- 
fion, or who look at objeds very near, cpntrad ^ 
habit of fquinting; but this deformity gradually 
difappears. Strabifm may arife alfo from a weakr- 
nefsoffomeof the mufcles, which produces am 
irregularity of their adlion. 

In this cafe, when it is not of long Handing, it 
may be corre6led by placing on the eye which 
fquints a conical tube, blackened in the infide, 
and which ought to be gradually turned towards 
that lide to which the eye can with difficulty be 
dire<5led : this method mud be often employed and 
for a long time. 

Strabifm may be likewife occalioned by an al- 
teration of fome parts of the eye. Perfons fquint 
alfo inftantaneoully when they look at objedl^- 
yery near, or with diftradion, or when they are in 
an ecllafy. 



Some perfons do nOt fee ol)je6ls di(lin6lly but 
at a very fm all diftance. In this cafe, the eye ball, 
for the moit part, is elongated and projecting, and 
the cornea very convex. Perfons who exhibit this 
difpolition are obliged to place the objects near to 
their eyes ; but they have the advantage of poffelP- 
Ing good fight and, of feeing diftindlly the fmalleft 
obje^is. It may, indeed, be readily conceived that 
the objedl being placed nearer to the eye, muft 
fend out a more confiderable bundle of luminous 
rays; and fince the eye receives thefe rays under 
a greater angle, they are refracted with more difl 
ficulty and are longer in uniting. This difpofition 
is neceflary, becaufe the retina is further diftant 
from the cornea, on account of the greater elon- 
gation of the eye-ball, or of the greater convexity 
of the cornea. 

If the rays which fall upon a convex and elon- 
gated cornea were more convergent, or aim oft 
parallel, like thofe proceeding from diftant objefts, 
they would be too foon refrafled ; their conver- 
gency would take place before they reached the 
retina, and villon would be indiflinct. 

Shortnefs of fight, which varies from half a foot 
to half an inch, is diilinguiflied by the name of 

This affection exifis in all infants, and gradually 
decreafes : fometimes it exifts till the period of 
manhood, and is gradually corre<51ed by the de- 

-preffion . 


preflion of the eye-ball, efpecially in perfons who 
fatigue their eyes a. great deal, by continual occu- 
pationn at a very faint h'gbt. Perfons very fhorU 
lighted- appear, in general, to fquint, becaufe ihey 
are obliged to incline to one fide in order that the 
objedl may remain illuminated ;^4ind becaufe they 
often look with one eye^ while the other rolls about 
at random, 

Short-fighted peopie acquire a habit of not 
looking at thofe to whom they fpeak, becaufe they 
can fee nothing in their face. 

Old men often exhibit a difpoiition contrary to 
that of myopia ; they do not fee objeds but at a 
very great diftance; and their eyes aregenerally fiat* 

Long fight, known by the name of -prefbyofia^ 
and which extends even to three {^tX, is always 
very weak ; it feems to arife from a flattening of 
the ball of the eye, which diminifhes the'power of 

As the eye has lefs refractive power, and as tha 
retina is brought nearer to the cornea, by the flat- 
tening of the eye-ball, the rays mufl neceffarily 
be lefs divergent. Thefc rays then being nearly 
parallel, are more eafily refradfed, and their conver- 
gency being fpeedier, may take place on the retina 
brought nearer to the cornea. But if the rays are 
exceedingly divergent, they aire refracted with more 
difficulty; their convergency takes place behind 
the retina, and vifion is indiftind. 

In prefbyopia, the fight is neceffarily weak, fince 
VOL. III. R -. th$ 


the objedl muft be didant, and becaufe the mafs 
of the luminous rays decreafes in the ratio of the 
fquare of the diftance ; fo that an obje6l three feet 
from the eye fends to it a quantity of light nine 
times lefs than if it were placed at the diftance of 
a foot. The difference between a myope and a 
prefbyta is, that the former fees only by very di- 
vergent rays ; while the other fees by rays almofi: 

Myopia is corre6led by placing before the cor- 
nea a double concave glafs, which refra61s the rays 
proceeding in a parallel direftion from a diftiant ob- 
ject, and gives them that degree of divergency 
which they would acquire if the objed: v^ere at the 
natural point of fight. Each cavity ought to be 
a fegment of a fphere, the radius of which is equal 
to the diftance between the cornea and the point 
where the objed would be vifible. 

Prefbyopia is corrected by placing before the 
cornea a double convex glafs ; this glafs colledls; 
the divergent rays, and makes them to fall in a pa- 
rallel diredion on the cornea, which refracts them 
with more eafe on the retina. The rays which the 
pye then receives in a parallel direction are as nu- 
merous as thofe which it would receive obliquely 
from the fame point of diftance ; the objedl isfeeii 
very much illuminated, very diftind;, and appears 

That viiion may be perfecfl, every part of the 
eye rnult be in a found ftate ; the membranes and 



their humours mufl poflefs great tranfparency, 
^nd the nerves muft be endowed with their full 

The fight is weakened or impeded by fpots on 
the cornea (fpecks); by opacity of the cryftalline 
humour (a catara3) ; by palfy of the optic nerve 
(amaurofts) ; by confufion of the vitreous humour 
(glaucoma) ; and by all other alterations of which 
the different parts of the eye are fufceptible. 

The retina, confidered as the efTential feat of 
vifion, is an organ endowed with a very fine and 
dehcate fenfe of touching ; fince it perceives th'e 
impreflion of all the modifications of the light re- 
flected from the bodies, and refra<5led on it by the 
humours of the eye. 

This organ, which cannot enable us to judge of 
the magnitude and difi:ance of bodies but by the 
aid of touching, is that however which recalls the 
greatcft number of fenfations in a given time ; it 
brings the individual foohefl into relation with ex- 
ternal objefts, by inflantly pafling over very large 
fpaces*. This organ, in confequence of habitual 
and continued exercife, acquires fo high a degree 
of utility and perfection that it is exceedingly diffi- 
cult to determine what is its real natural mode of 

This field of action is more than fufficient to 
fatisfy all our wants; but its extent is too limited 

* Light is faid to pafs over 164,000 miles in a fecond. 

R a to 


to gratify our curiofity : the eye, indeed, keeps us 
as far diflant from the infinitely fraall objetl which- 
is "near us, as from the infinitclv ereat one which it 
is impofIib]e for us to reach. 

34. Hearing. The organ of hearing contifls 
eHentially in a nervous expanfion, proper for re- 
ceiving the impreffion made on it by thecontadlof 
the air, in a lliate of vibration. 

The auditory nerve is expanded in the middle of 
a vifcous fluid, contained in a membranous cover- 
ing, and enclofcd by the ofleous labyrinth, 

The labyrinth is compofed of three femicircular 
canals, fhaped like the fiiell of a fnail, which have 
a communication with each other through the 
veflibulum, by means of fix apertures, five of 
which belong to the three canals. 

The labyrinth has a communication with the 
tympanic cavity by two apertures, one of which 
is round and correfponds to the bottom of the in- 
terior fcala of the cochlea ; and the other proceeds 
into the veftibuium. The firil is clofed by a mem- 
brane, and the fecond by a fmall bone. 

The tympanic cavity communicates with the 
bottom of the mouth by a long narrow canal (the 
Eufiachian tube). This cavity is fhut externally by 
the raembrana tympani. 

The membrana tympani correfponds with the 

hole of the veilibulum by-iiferies of four fmall 

^ boneS;, 


bones, Avhlch are moved by a few fmall mufcles. 
It is the bafe of the ftapes which is. applied to the 
hole of the viflibulum, where it is faftened by the 
periGileum ; the handle of the malleus is fixed to 
the centre of the membrana tympani. All this 
apparatus is preceded externally by the auditory 
conduit of the ear^ and by its concha, 

Elaftic bodies/ ftruck or diilended,jchange their 
figure, and return to their nrft ftiate, by vibrations 
more or lefs manifefi:. Darins: thefe vibrations, 
the integrant moleculce of the bodies experience a 
particular movement, a fort of quivering or vi- 
bration, which is communicated to thefurroundins: 
air, and is propagated to a gi eater or lefs diflancc. 

The column of air, thus in a ftate of vibration, 
which ftrikes the "ear, produces on the expanfion 
of the auditory nerve an impreffion of contadl, 
which is comiTiunicated to the brain. 

The vibrations of bodies which take place in- 
flantaneoufly, or in a confufed and inappreciable 
itianncr, confliitute no'ife ; thole which regularly 
fucceed each other produce /oK7z.i. 

Noife or found always arifes from the entrance 
of air into the vacuity, left inftantaneoufly by bo- 
dies flruck or diftended. 

Air may enter into a ftate of vibration by an 
immediate fhock ; and it then produces noife, 
found, voice, fpeech. 

Sound is propagated in every direcftion with an 
R 3 uniform 


uniform velocity, of about 1 142 feet per fecond, 
plus or minus the velocity of the wind, according 
as it is in a contrary or a favourable dire<ftion. 

Sounds which flrike elaftic bodies are refle61ed 
• at an angle equal to that of their incidence. Reflect- 
ed found exhibits the fame phaenomena as diredl 
found, and conflitutes echo. Sound is ftronger, 
and is propagated to a greater diftance, according 
as the air is more condenfed. 

The inteniity and propagation of found increafe^ 
as the fquare of the denfity of the air, 

Tfie force of found is weakened by the hu- 
midity of the atmofphere; fo ihat it is propagated 
more eatily as the air is colder and drier^ 

Sound, by being propagated, decreafes in inten- 
fity, as the area of the bafe of the cone which it 
forms increafes. This intenfity, therefore, is four 
times as weak when the diftance is double. 

Sound is flronger as the vibrations are greater; 
but it remains the fame. Sound does not change, 
but when the vibrations are more or lefs numerous 
in a given time. 

In grave or low, founds, the firings perform fewer 
vibrations in the fame time than acute or loud 
founds. When the number of the vibrations is 
too fmall or too great, the found is not perceptible 
by our organs. 

' According to Euler, we cannot appreciate a 
grave found which has lefs than thirty vibrations, 



nor an acute found which makes more than 7552 
in a fecond. 

Thefe limits offound, appreciable by the human 
ear, are included in the octave. 

The number of the vibrations depends on the 
fize, length, and lenfion of the fonorous firings. 
This number of vibrations is in the inverfe ratio of 
the length and (ize of the firings ; and in the di- 
rect ratio of the flretching forces. 

Two firings are in unifon when they perform 
exadly the fame number of vibrations in the fame 
time, and produce the fimplefl concord. 

When an acute found produces exadlly twice 
as many vibrations as a grave found, it is faid to 
be its o6lave ; and the double octave when it pro- 
duces four times as many. 

If the acute found produces three times as many 
as the grave found, it conftitutes its fifth ; and its 
double fifth when it produces fix times as many, 

All the aliquot divifions of a firing give the 
harmonic founds of fundamental bafs. 

A found is flrong or weak, according to the 
greatnefs of the vibrations; grave or acute accord- 
ing to their velocity ; and harfh or foft according 
to the particular nature of the inftrument. 

The quality of the found depends on the nature 
of the inflrument, and verv often it is not known 
in what it confifts, 

R 4 The 


The tone depends on the manner in which the 
inflrunient is played, and varies with the artifts. 

Sound, }Todnccd either by ftriking a bell or a 
ftring, the vibrations of which are communicated 
to the furrounding air, or by the immediate 
collifion of the column of air, as is the cafe in 
wind inftrumcnts, is propagated in a diverging 
manner in every dire6!ion. 

The fonoroLis rays which fall on the concha of 
the ear, are dire£ted towards the auditory conduit, 
and ilrike againfl the membrana tympani. The 
vibrations are communicated to the air contained 
in the tympanum, and arc thence tranfmitted to 
the fluid in which the acouftic nerve expands; 
and the nerve receives an imprefiion of contad. 

This impreffion is propagated as far as the brain^ 
and iniiantaneoufly produces a general change of 
Hate, which is called thefenfation of found. 

The movement of rea6tion, which the brain 
produces in all the organs, in confequence of the 
impreffion made on it by the auditory nerve, is 
often very remarkable. Thus a fudden and un- 
expeded noife produces a new mode of a61ion, 
which is particularly obferved in the mufcles, in 
the organs of circulation and refpiration, in the 
gaftric fyftem, and even in the Ikin, 

In children, a weak found produces very little 
imprefTion, though the ear has already acquired 
Its whole development. This organ muft be long 



' ( 

exercifecl before it can acquire that degree of per- 
fedion of which it is fafceptible ; and to many 
perfons the fineft mufic is nothing but flunning 

But, when a tender and harmanious found fud-^ 
deply ftrikes an experienced ear, it immediately 
produces a particular change in the whole Ij'ftem; 
a fenfation is experienced, as if fomething were 
ilowing through every part of the body ; a pecu- 
liar flate of fpafm is produced ; circulation and re- 
fpiration feem to be flackened ; a fenfe of con- 
ftri(9aon towards the epigafcrium is felt, and the 
ikin becomes corrugated. ' 

IMone but perfons feniibleto the charms of har- 
mony can be fully acquainted with the change 
which may inftantaneoufly take place in the 
whole organization, in confequence of enchanting 

The peculiar cWgSl produced on the organiza- 
tion by mufic depends, on the one hand, on the 
nature of its compofition, and on the other, on the 
feniibility and peculiar difpofition of thote who hear 
it ; and in ell thefe points of view it exhibits re- 
fults very different. 

Mufic has fo powerful an a61ion on the organi- 
zation, that it has often been propofed and even 
employed with fucccfs in the cure of fonie difeafes. 

It is infiirumental mufic, in particular, vvhen 
performed in an afFecling manner, which pro- 


duces the greateft effed on man. This mufic 
feems to maintain, in every part of the body, a 
regular motion, which is renewed at each beat of 
the meafure ; and as we may fay exalts the or- 
ganization to fuch a degree as to make it overcome 
the greatefl efpDrts. It is well known how much 
the found of the drum faciHtates marching, and 
what a degree of courage has often been produced 
during the time of a battle by a martial air. 

It is in large cities, in particular, that the in- 
fluence of mulic feems to be molt remarkable. 
A young delicate female, who could not walk a 
few miles to a ball, when conveyed thither in a 
carriage, is fometimes able to dance four or live 
hours without intermiffion. 

Were Ihe to fnut herlelf up in a room alone, 
and try to jump about in this manner, at the end 
of a quarter of an hour fhe would fall down on 
the floQr exhaufted with fatigue. It is the muiicj 
in a great meafure, which renews and maintains 
this a61ion ; the fplendour of the lights and drefles, 
and the prefence of a handibme young man, con- 
tribute alfo to exalt it. 

35. Some have often found it difficult to con- 
ceive how feveral founds can be propagated fimuU 
taneoufly in the air, and how the ear can perceive 
them at the fame time. 

When two founds are produced together, they 



are either propagated fucceflively in the moft di- 
vitible parts of time, or they combine, unite, and 
form only one found, which the mutician always 
knows to be the refult of two inftruments 3 or 
both founds are diflurbed, become confounded, 
and produce only noife, which the ear is not able 
to appreciate. 

What has been here faid in regard to the fi- 
multaneous propagation of two ibunds, may be ap- 
plied to that of fifty, and ferves to explain their 
mode of a(51ion on the organ of hearing. Two 
founds, indeed, produced together, may necefla- 
rily reach the ear at periods the nearelt to each 
other poffible, and are then perceived one after 
the other; or they reach it at the fame time, and 
in this cafe produce only a fingle impreffion, 
which is neither that of the found A, nor of the 
found B, but which refults from the combination 
of both, and which often a muiician only can di- 
ftinguifh, becaufe he is acquainted with the- for- 
mation of them. 

It is very difficult to determine what is the ac- 
tion of each part of the ear during the perception 
of found. The fmall mufcles attached to the 
chain of fmall bone?, which extends from the mem- 
brana tympani to the aperture of the vellibulnm, 
may by their adlion Itretch or relax that membrane; 
remove from or bring nearer to the aperture of the 



veftibulum the bafeof the flapes, and thus favour 
cr oppofe the propagation of found in the labyrinth : 
but all this apparatus is not indifpenfably neceffary 
for hearing. 

The eflcntial part of hearing, which is found 
in all aninials^ and which in a great number is the 
only one that cxifts, is the membranous capfule, 
containing the vifcous fluid in which the auditory 
nerve expands. This nervous espanfion alone 
can even tranfinit to the brain the imorefiion 
made on it by the contadt of a body in a Itate of 
vibration, and caufethat or^^-an to produce tire ge- 
neral and inilantaneous mode of aifl'lon which con- 
ftitutesthe fenfation of found. The external part 
of the ear in man may be removed vidthout great 
inconvenience; and the ears of dop-s and horfes, 
which are much larger, are daily cropped without 
doing them much injury. ' Obiiru6lion of theau- 
dito'.y conduit docs not occafion complete furdity j 
and though people flop their ears as clofely as 
poiiibrej they can ftill hear ibunds of a certain de- 
gree of firength. 

Hearing relults from a vibratory motion com- 
rnunicated to the fluid contained in the labyrinth ; 
and this motion may be tranfmitled even through 
tiie bones of the,; head, as is the cafe in iifhes, 
which have no auditory conduit, and whofe organ 
of hearing is enclofed in the cranium. 



The membrana tympani is often found dedroyeda 
even with the lofs of fome fmali bones, and yet 
deafnefs is not neceflarily the refiilt* 

Perfons who have the membrana tympani pierced, 
can in fmoking a pipe make the fmoke ilTue from 
the ear : in this cafe the fmoke pafies through the 
Euftachian tube. 

This guttural conduit of the ear, which has 
been fuppofed to contribute, in an edential man- 
ner, to hearing, becaufe people often liden with 
their mouth open *, feems to be deftined for the 
purpofe of affording a free entrance to the air 
into the tympanic cavity. 

Though all the acccffory parts of the ear are 
not abfolutely neceiiliry foi; hearing, they together 
Contribute a great deal tou-ards Ihe perfeftion of 
that fenfe ; and the deftruclion of them tends al- 
ways, more or lefs, to weaken it. Deafnefs is the 
neceffiiry refult of the lofs of that fluid contained 
in the m.embranous labyrinth : in the bodies of 
fome old men, who had continued deaf for feveral 
years, the ofTeous labyrinth has been found empty. 

The fluid of the labyrinth may be effufed into 
the tympanum, by the deftru61ion of the mem- 
brane which flints the aperture of the concha, or 
by the removal of the flapes, the bafe of which 
fliuts the aperture of the veftibulum ; and thefc 
accidents mult neceiTarily produce deafnefs. 

* Conticuere omnes, intentique ora tenebant. 



Weaknefs of the auditory nerve occafions dull- 
nefs of hearing ; a pallied Hate of it gives rife to 
complete deafnefs. 

The fpiral of the two fcalas, which the concha 
exhibits, has induced fome to beheve that it ferves 
for receiving nervous cords, of different fizes, in a 
flateoftenfion, and fufceptible of entering into vi- 
bration and of putting themfelves in unifon with 
different tones ; and that under this point of view 
the ear refembles a harpfichord. But this fyflem 
of extended cords, which would be ufelefs in the 
midft of a fluid, is not to be found. The concha, 
which does not exifb in all animals, and which 
varies in its form in different claffes, feems to be 
deftined only for the purpofe of prefenting a 
greater furface to the expaniion of the auditory 

The only condition neceffary for having the fen- 
fation of found is, the impreffion of contact made 
on the nervous expanfion^ by the vibrations of the 
medium in which it is placed. 

The organ of hearing, which alone leaves only 
the vague fenfation of a change having taken place 
in the ear, becomes of the greatefl utility by its 
fimultaneoiis exercife with the other fenfes, and 
concurs in an eflential manner towards the pro- 
grefs of civilization, as it makes men to communi- 
cate, in a direct manner, with each other, by means 
of the voice. 

S6, To 


36. To comprehend properly the progrefs fol- 
lowed by the organs of the fenfes, and by the 
mufcular fyfiem in the development of their func- 
tions, and in their individtial orfimultaneous a<5tion, 
thefe organs muft be obferved in children at the 
period of birth ; and their progrefs muft be traced 
during the firft years of life and to the age of man- 

At the nrtoment of birth the foetus, habituated 
to a refidence in the matrix, where it is furrounded 
by a fluid at the fame degree of temperature, and 
in continual reft, without refpiration and digeftion, 
receives at its birth a fudden and lively impreflion, 
by the contaS: of folid bodies, by that of the light, 
by the change of temperature, and from the air 
which ftrikes it externally, and which is introduced 
into the lungs. The general change which is 
.thus efFedled in all the organs, reduces it to a ftate 
of unealinefs,' which determines the firft move- 
ments it makes and the firft cries it emits. 

Soon after, the gaftric fyftem makes it experience 
an uneafinefs which arifes from- a new want. All 
the parts of this fyftem enter into adlion, and re- 
quire the prefence of that aliment on which they 
are deftined to be exercifed. 

The mufcular fyftem, at firft, performs only fud- 
den and uncertain movements. The aftion of 
the flexor mufcles, whicli is ftronger than that of 
the extenfors, keeps the limbs in an habitual ftate 



of flexion. If the child be placed upright, its ab- 
dominal limbs perform alternate movcmeais of 
fiedion and ezreniion, and ftretch themfelves 
againil the reliflance of the ground. Th&ir arms 
move in every dire6iion, and their fingers, habi- 
tually bent, grafp with violence every body that 
falls in their way, were it even a piece of hot iron. 
All thefe trials develop the function of the muf- 
cular tj^ftem, and prepare it for more regular move- 

The eyeSj at firft, troubled and confufed, become 
brighter, and begin to be ftruck. by the impreffion 
of the ilrong light, and then by very luminous 
bodies and by fplendid colours: this impreffion 
gradually becomes diftindl, and the hands, already 
habituated to grafp, make further efforts for that 
purpofe ; the child then extends Its arms towards 
the luminous object, and feems delirous to touch 
it, at whatever diftance it may be. 

In this cafe, the eye only learns that an objedl 
exills in the direftioji of the vifvial axis ; the hand 
is direcied thither, reaches it, touches it, and thus 
afcertains its diftance, its form, and its volume, S:c, 
The cafe is the fame with the organs of the 
other fenfes I they all mutually affift each other? 
and their individual perfediion is the refult of their 
fimiultaneous adlion. 

3 7. The apparatus of locomotion, and the diiFerent 

fy items 


fyftenis of the fenfes, the fundlions of which we 
have examined, are the organs which in an effen- 
tial manner eftablifh a relation between us and 
external objefts. The aggregate of them, which 
conflitutes relative life, gives for refult a feries of 
very remarkable phaenomena. The central fyftem, 
by means of the nerves, diftributes to them the 
efTential principle of life. The impreflion made 
on thefe nerves is tranfmitled to the centre of the 
cerebral fyflem and modifies its adlion ; fo that the 
adlion of the organs of motion and of the fenfes 
is fubordinate to that of the cerebral lyftem, as 
that of this fyflem is fiibjecSled to different impref- 
fions, communicated to it by the nerves of thefe 

The impreffion made on the nerves of any part, 
by the contacSt of fome foreign fubftances, may be j 
tranfmitted to the centre of the cerebral fyltem, 
^nd modify its natural adlion. 

For the moft part, the new mode of action is 
particularly remarkable in the funftion of the or-^ 
gan which has received the impreflion. At other 
times, it appears in a diftant part, and fometimes 
it announces itfelf by an univerfal and uniform de- 

The new mode of adion which refults from 
every change in the brain may become the caufe 
of a new a6lion, which continues i fo that the de- 
rangement is continued by the confequence of 

VOL. Ill, s iti 


its firfl rcfult : fuch is the cafe in almoft all 

38. Senfations being the refult of every fudden 
change which takes place in the whole of the or- 
ganization, it is obferved thcit children do not be- 
gin to give apparent figns of them, until this 
change is fufficiently ftrong to reduce them to a 
ftate of uneafinefs. All their firft fenfations, indeed, 
are painful, and are announced by cries and move- 
ments. This (late of fufFering, in which the child 
is 'placed in confequence of its firft fenfations, is 
neceffary to excite it to adts which mud contribute 
to its prefervation, othervvife, after being born, it 
would fufFer itfelf, through indifference, to perifli. 
But there (bon take place in its organization changes 
of fuch a nature, that they are capable of deftroying 
it, and which reduce it to a fiate of uneafinefs it is 
incapable of fupporting. It moves at random to 
change its pofition, in order to fatisfy its wants, and 
pain becomes to it the firfi caufe of all its a6lions. 

Inftead, therefore, of pitying in a ridiculous 
manner the fate of the human race, who are faid 
to be born to fuffer, and whofe firfi figns of life 
are announced by cries, we ought to confider thefe 
cries, and the pain which produces them, as the 
firft caufe of the rapid development of all our fa- 

One of the mofi: afionifhing phenomena of the 



organization prefents itfelf even at this early pe- 
riod : the living being has a ftrufture which muft 
develop itfelf in a determinate order. When this 
order is effentially deranged, all the fyftems of 
organs experience an extraordinary movement ; a 
peculiar rea6lion, v^^hich lafts till calmncfs is re-- 
liored, or until the equilibrium be entirely de- 

The general orparticularftateofdiforder, of which 
the whole of the orgaiiization is confcious, and which 
conftitutes ihc fenfation of fain^ is indeed the jnofl 
important and mofl wonderful phEenomenon of 
life. The impreffion of contadi:, made on the or- 
gans of the fenfes, is tranfmitted to the brain by 
means of the nerves, and produces there a new- 
mode of adion, the refult of which is a certain 
change of ftate in the whole organization. This 
change of ftate, which conflitutes fenfation, may 
be inftantaneous or continued for a longer or 
(horter time ; and in either cafe it eflentially varie;s 
in three ways, ift. It tends to derange the natu- 
ral order of the fundlions, and conflitutes the 
gainful fenfation. ad. It tends to ftimulate the or- 
gans in a proper manner, and to exalt their habitual 
adlion, which it caufes to be exerted in a fuller 
manner, and conftitutes the agreeable feffailon, 
jjd. It does not fenftbly difturb the natural order, 
and yet conftitutes an appreciable change of ftate, 
which is the ftmpk fenfation. The painful fenfa- 

s 2 tions 


tions are the ftrongeft and the firft felt ; the agree- 
able fenfations cannot be well appreciated but by 
repeatedcontraft with the painful fenfations; without 
the latter the agreeable fenfations would be merely 
the natural a6tion of the functions, exerciling it- 
felf with more or lefs intenlity. In the lafl place^ 
the frequent and fully-perceived alternation of the 
changes of ftate, refulting from a perturbation of 
the tun61ions and from their natural a^ciorj;, per- 
formed with more or lefs energy, gradoally en- 
. ables us to appreciate changes of ftate^ though in- 
different in regard to t lie organic order. 

As the child grows up, and its organs are de- 
veloped, it is enabled, by habit, to appreciate bet- 
ter the new modes of a6iion which take place in 
its different functions ; and it at length becomes 
fenfible to the flighlefi: changes which are pro- 
duced in its organization. 

After a certain period, the child finds that it has 
experienced agreeable and painful fenfations ; it 
makes an effort to avoid every thing which has al- 
ready reduced it to a ftate of fuffering, and endea- 
vours to replace itfelf in thofe pofitions which it 
before found favourable. 

Thus, to avoid pain and to obtain eafe are the 
firft elements of its education. 

At this period, one begins to obferve that thefe 

lenfations are renevi-'ed without the prefence of all 

thofe objects which at firft produced them. This 

_ phse- 


phenomenon, which is undoubtedly the moft im- 
portant, and the moft neceflary to improvement, 
requires to be carefully confidered. 

39. In order to comprehend properly how a 
fenfation may be entirely renewed, merely by the 
prefence of a part of the objects which firll pro- 
duced it, we mull keep in mind that the apitude 
Oi the organs to difcharge their functions increafes 
by exercife ; that they have all a great tendency 
to habit, to perform the fame a(5lions, and are en- 
dowed with a great force of imitation. 

We, indeed, know that the organs are 
ftr-:nglhened arid improved by a proper exer- 
cife of their funftions ; and that at the end of a cer- 
tain period they all perform with- eafe thofe actions 
which at firfl were attended with a great deal of 
diiiiculty.. Thus, the mufcles which, at firft, per^ 
form only fudden and irregular motions, give by 
long habit and continued exercife movements, the 
variety* agility, and fafety of which are inconceiv- 
able, as is obferved to be the cafe, in tumblers^ 
dancers, organills, &c.; and it is to be remarked, 
cseteris paribus, that the muiician, for example, 
who performs bed a piece of mufic on the piano- 
forte and the violin, is always he who has exer- 
cifed himfelf moft on thefe inftruments ; and that 
in this department, as well as in others, it is al- 
ways by long exercife that people are able toover- 
§ 3 coms 


come great difficulties, independently of the 
greater or lefs faculty which refults from an advan- 
tageous prganic difpofition. 

What has been here faid refpeding the mufcu- 
lar apparatus, may be applied to all the reft, and in 
particular to the cerebral fyftem, the functions of 
which I fhall here endeavour to explain. 

Of all the iyftems of fundions, that moft habi- 
tually in a6lion, no doubt, is the cerebral fyftem, 
fince it is continually diftributing to all the parts 
the principles of life, by means cf the nerves; 
and is continually receiving the impreffion made 
on thefe nerves by foreign bodies. I have already 
faid that the change of ftate, refulting from an im- 
preffion tranfmitted to the cerebral organ, and 
which conftitutes fenfation, does not appear to be 
felt by the child until this change is fufficiently 
ftrong to produce a confiderable derangement in 
its organization ; that the child then becomes fenft- 
ble to the impreffion of objeds which tend to fa- 
tisfy its wants, and to caufe its funtlions to be per- 
formed with more energy ; and that it at length 
becomes able to appreciate a change of ftate which 
does not difturb the order of the fundllons. 

When the child begins to receive thefe three 
orders of fenfations (painful, agreeable^ Q.ndjimple)y 
it is obferved that the fimple fenfations are at firft 
few in number, but that they embrace fimultane-^ 
oufly a great number of particularities, not per- 


ceived, which gives reafon to believe that children 
generalize: in proportion however as the fenfa- 
tions are repeated they become complex by an ana- 
lyjis of the principal obje£b. 

Thus a child begins to fee in its mother a wo- 
man, and all women make it experience the fame 
fenfation ; but it fees its mother every day, and 
almoll during the whole day : this fenfation, there- 
fore, which is fo often repeated, allows the child 
to receive particular fenfations by obferving her 
height, her features, her drcfs, the found of her 
voice, the care five pays to it, &c. All thefe par- 
ticular fenfations remain united to the general fen- 
fation, and arc fimultaneoufly repeated. 

The cafe is the fame in regard to all the objedls 
with which the child is continually in relation: their 
prefence, at firtl, makes it experience only ona 
fenfation, but which is afterwards rendered complex 
by the fucceflive difcrimination of the different 
parts which conftitute it. All thefe particular fen- 
fations are always connected with the principal 
objed, and are conllantly renewed in the order 
in which they are acquired,. 

A feries of fenfations, produced by an object and 
its attributes, is then renewed entirely by the force 
of habit, on feeing one of the fm al left circum fiances 
which were conneded with it, or merely by the 
light of an objeft which exhibits any refemblance 
or analogy to the firfl. 

s 4 Thus 


Thus a fcries of lenfations mull be confidered 
as a peculiar aft of the funftion of the cerebral {yf- 
tern, and of which the individual is confcious by 
the dire6l relation which this fyftem has with the 
whole organization. This feries of fenfations is 
then repeated with the more facility, the oftener 
they have been excited. They may be entirely re- 
newed, not only by the prefencc of the principal 
obje6l which contributed to their formation, but 
by all its accefibry circumftances j by every thing 
which has a more or lefs dire6l relation with it, gr 
a certain refemblance and fort of analogy to it ; 
and as there is no feries of fenfations, a part of 
which is not connected in fome points with another 
feries, it thence follows that they may all be re- 
newed by each other, according to the relation- 
which exifts between them. 

At the end of Tome years, the child which, by 
exercifing its organs of the fenfes and of motion 
on all the objedls around it, has already experienced 
a numerous feries of fenfations, fulceptible of being 
renewed with great facility, and which, on the 
other hand, isirrefiltibly excited to adion in order 
to withdraw itfelf from pain, and to fatisfy its 
wants, is foon capable of comparing its prefent fen- 
fations with fenfations recolledied, and of com- 
bining them in a manner mod proper for its pre- 
fervation. It is thus that the firll operations* of 
the underftanding feem to be performed. When 



the development of tbefe operations is well under- 
ftood, it will be eafy to trace the progrefs of thofe 
which refult from the fucceffive improvement of 
the intelle£lua,l organ ; for it is not fo difficult to 
determine in what manner man has attained to the 
higheft degree of improvement, as to conceive 
how he began to combine the iirfl two fenfations. 

40. Among people lefs advanced in civilization, 
as the inhabitants of New Holland or the favages 
of America, the child during the firft year of its 
life muft exhibit nearly the fame feries of phaeno- 
mena as among more enlightened nations; but the 
further development of their organization is very 
limited, efpecially in regard to intelligence ; and 
man, in thefe countries, has only that degree of 
fuperiority over other animals which naturally re- 
fults from an organization evidently more advan- 

The people of thefe countries, indeed, notwith- 
ftanding their antiquity, have ftiil a language ex- 
ceedingly limited ; they are fcarcely acquainted 
with the art of conftruding huts ; they feed on fifh, 
game, and the natural produdions of the earth ; 
and none of them have carried their induftry fo 
far as to preferve animals for increafing their breed : 
in a word, the inftruments of the greater part of 
thefe tribes are as yet exceedingly rude. 

It is to be remarked, that thefe people inhabit 



the fined: countries on the earth ; and it is pro- 
bable, that this circumftance has been an obftacle 
to the progrefs of their improvement. I have aU 
ready faid, that in a child the firll excitement to 
a^lion^ the firft thing that promotes its education, 
is the neceffity it experiences of withdrawing itfelf 
from ^ain, and of fatisfying its*wants. 

The man continues to experience the fame prin- 
ciples of adion, and is ftill excited to induftry by 
the neceffity of preventing or repelHng the attack 
of his neighbours, or by the delire of invading 
them to feize on the fruits of their induftry. But, 
in a fertile country, which furnifhes for its few in- 
habitants abundance of food without much labour, 
and which being of a mild temperature does not 
reduce them to the neceffity of fecuring them- 
felves either from intenfe cold or exceffive heat, 
man has no motives fufficiently powerful to induce 
him to make a rapid progrefs towards improve- 

Among thefe people, the progrefs of the de- 
velopment of the different organs being very in- 
confiderable may be readily conceived ; but in 
feme countries of Europe man, during a great 
number of ages and continual revolutions, ac- 
quires fuch a degree of improvement, that he can 
no longer difcover the point from which he pro- 
ceeded, nor trace out the path which he purfued. 

41. I flial! 


41. I fhall not here enter into a long detail of 
the ilow and facceffive progrcfs which nnan muft 
liaye made before he could attain to his prefent 
degree ; of in telle6lual improvement; this labour 
v/ouid be tirefome and ufelefs. Having exhibited 
a vie'A' of the manner in which the intelle6lual fa- 
culties are tirft developed among different orders, 
and having given a Abort defcription of the ftatc 
of man among the moft ignorant tribes, I (hall 
purfue the further development of the humaa 
mind among the mofl civilized nations. 

The child which is educated among an enlighten- 
ed people learns, at an early period, to employ that 
inilrument which becomes to him the grand means 
of communication and of improvement. Lan- 
guage has not been given to man, like hearing and 
feeing, as is commonly fuppofed ; it is the floMT 
and laborious refult of his induftry ; it is one of 
the great difficulties which he has been able ta 

I/O fpeak is a thing fo difficult, that children, if 
not early acculiomed to it, are fcarcely able after- 
wards to acquire the faculty of fpeech, as has' often 
been obferved in individuals educated alone in the 
woods, and as may be feen at prefent in regard to 
the favage of Aveyron. This child, who poiTefTes 
a good common underflanding, finds it exceed- 
ingly difficult to pronounce a few words ; it wa« 



much eafier to make him comprehend that we ex- 
prefled things by written figns, and to teach him 
thefe figns, than to make him pronounce the founds 
which exprefled them. Thus, when he is about 
to walk to the obfervatory, where he fometimes 
receives milk, he takes his copper letters in his 
pocket, and combines, before the perfon w ho gives 
him the milk, the four letters which reprefent that 
fubftance. Speech rcfults from the fucceffive 
and limultaneous adlion of a great number of fnnsl! 
mufcles. This adion is exerciled in fpeaking v/ith 
a mobility and preciiion which can be acquired 
only by long exercife ; fo that it muil be as diffi- 
cult to teach a perfon to fpeak, who has fpent the 
firft twenty years of his life alone in the woods, as 
to make him play on the harpfichord. 

What itill further proves that language is merely 
3 human acquifition, and that man does not na- 
turally fpeak with facility is, that perfons born deaf 
are always dumb. 

What valuable advantage the child derives from 
its intimate relation with its mother, who is con- 
tinually under theneceffity of fpeaking to it, and 
who always points to the obje6l when (he pto- 
nounces the word which exprellesit? The child is 
thus irrefiftibly ejjcited, by its propenfity to imita- 
tion, to make an effort to pronounce the lame found. 
The organ in developing itfelf is properly modi- 


fied for that exercife, infeniibly contrails a 
habit of it, and at length appears to have acquired 
it without difficuly. 

The propenlity to imitation, which in children 
is very great, would be continued with age, as in 
apes, were not its place occupied, fooner or later, 
by a defire of a6ling according to the dictates of 
the will. 

This tendency appears to be merely an exten- 
iion of the faculty and of the need of involuntarily 
repeating actions which are familar to us ; and is 
extended even to aftions which we fee performed. 

At the end of fome years, when the child has 
beard pronounced, and has itfelf repeated, a great 
number of times, the words which reprefent all the 
obje6ls with which it is in relation, and when it 
has contra61:ed the habit of applying them fpeedily, 
and with eafe, to the things represented ; in aivord, 
when it begins to fpeak, its inftruftors do not fail 
to teach it that all thefe words are reprefeated by 
conventional figns. By long exercife it at length 
becomes able to diftinguifh them with eafe, and to 
follow with rapidity theircombination in the forma- 
tion of phrafes ; and at laft acquires the habit of 
delineating them itfelf: that is to fay, it ;can read 
and write. When potlelled of thefe inftruments> 
and when they have become very familiar to it, 
the fun6lion of its intelletilual organ loon becomes 
extended, and in the development of it all the 



principal phagnomena of intelligence may be ob- 

42. It has been already repeated feveral times, 
and it ought never to be forgotten, ibat fenfations 
are the refult of an imprefiion tranilxiittpcl by the 
nerves to thebraiDj which experiences a Dew mode 
of a6{:ion, followed by a general and inftantaneous 
change of ftate in the whole of the organization. 

Senfations are dire6l or recolle6led. Recol- 
ledled fenfations are more particularly diflinguiHied 
by the name of /V/^^j. 

Ideas are always renewed in confequence of 
fome direfl: fenfations which recall them. The fa- 
culty of recalling a more or lefs extenlive feries 
of ideaSj in confequence of a fmall number of fen- 
fations, confiiitutes memory. 

When we have acquired a great number of differ- 
ent fenfations, every thing which furrounds us may 
recall them every moment; and we may continu- 
ally experience a thoufand incoherent and incon- 
gruous fenfations. This, indeed, is the cafe with 
manyperfons, and particularly with children, who 
are then faid to be fubje^l to diJtraBlon. 

The faculty of recalling all thofe ideas which 
have been acquired, in regard to any obje61:, ex- 
clulively of thofe which have only a very diftant 
relation to it, conllitutes attention. 

This faculty is one of the moft difficult io be 



obtained. It is acquired by long habit and clofe 
application to one particular fubjedl ; it is one of 
the conditions mofi: neceflary to the improvement 
of the underftanding. Vicq-d'Azyr is of opinion, 
that the greateft obftacles to the improvement of 
apes, arifes from their di fraction and great mo- 

43. When a child has feveral times experienced 
a certain number of fenfations, he foon begins to 
comh'me them, and to a£i agreeably to the refult of 
that combination. The development of the faculty 
of combining^ which is properly that of the under- 
ftanding, is the moft important to be obferved. 

I have already faid that the firft fenfations of a 
child are painful. By thefe fenfations it is irrefifti- 
bly excited to ad^ and to cry. It then begins to 
move at random, and to fend forth cries until the 
pain be allayed or the want fatisfied. 

After the painful fenfitions, it is foon obferved 
that it experiences fenfations of eafe ; and that it 
finds in the means proper for fatisfying its wants s 
fource of enjoyment and happinefs. 

At the end of fome time^ when the fame adions 
have been often repeated, it is obferved that fen- 
fations begin to be renewed in the child, without 
the concurrence of all thofe circumftances by 
which they were at firft produced. Thus the 



fight of the mother, who has often fatisfied its 
hunger, by exciting an agreeable fenfation, recalls 
to the child a feries of fenfations already expe- 
rienced. It dwells ii^on thefe renewed fenfations ; 
becrins to have attention, and thus learns to th'nik. 
While it thus dwells on its firft fenfations, others 
relating to the circumftances which accompany 
the a(fl of la61:ation are renewed ; it endeavours 
to fatisfy a want, to place itfelf again in an agree- 
able fitiiation : after this period it combines fenfa- 
tions with ideas j it judges and reafons j it then 
determines in confequence of its judgment, and 
thus produces an adl o( volition. It is iiadeed ob- 
ferved that it wiflies to approach its mother, and 
that it makes an effort to lay hold of the breafl 
with its lips. 

If the firft ads of intelligence in the child be 
thus carefully and minutely obferved, and if the 
connedion of them be properly followed, it will 
be feen that they are the neceflary refult of diffe- 
rent known properties. Thus it is remarked that 
the child a£ts, becaufe it is irreliflibly excited to 
do fo for its prefervation, by the ftimulus of pain ; 
and that it combines the prcfent fenfations with the 
pad, becaufe fenfations are renewed without the 
prefence of the principal objeft, and merely in 
confequence of fome circumftances connefted with 
it, and which recall it. But if, inftead of following 



this pro^efs, we take the flrongcft a6l of the hu- 
man intelligence, and endeav^our to difcover there 
the formation of the operations of thought, we 
fhall find nothing but an immmfe ahyfs^ and lofe 
ourfelves in conjedUire. 

44. Having followed, in the child, the con- ' 
ne6lion and fucceffion of thefirfi: aftsof the func- 
tion of its intellectual organ, employed almoft 
exclufively in fatisfying the firft wants of life, 
we dt' length come to the period at which it be- 
gins to feiijdy'all the advantages of fadtitious ligns, 
and to employ language with facility. We may 
then eafily judge in what ratio the progrefs of its 
intelligence muit increafe. 

By purfuing our examination of the organic 
phsenomena fiill further, we fhall find the firft 
caufe of action which^ as already faid, is' the ir- 
refiftibfe tendency to avoid pain, to fatisfy wants, 
and to obtain eafe, joined in fucceffion by many 
other principles of adion, in fondnefs for power 
or for refpe6l ; in the defire of acquiring know- 
fedge, arid in that of gratifying all our fa6titious 
wants,' ail habits. Sec' It is obferved, that the 
means of fatisfying thefe wants are developed 
along with them, and that they are merely an 
cxtenfiori of the firft faculty of providing for our 
prefervation, by a concurrence of adtions more oc 
lefs ftrongly combined. 

VOL. III. T ' A more 


A more profound examination of the phseno- 
mena which refiilt from a combination df fenfa- 
tions and ideas belongs to metaphyfics, and does 
not fall within the plan of this work. 

Metaphyfics ought to be only a neceflary con- 
fequence and continuation of phyfiology; and 
when not founded on a knowledge acquired in 
regard to the organization^ it will be unintelligible 
to all thofe who cultivate the exa6l fciences. 

45. It has been already faid that fenfations al- 
ways confifl in a new mode of action, produced in 
the cerebral organ, the refult of which is a general 
and inftantaneous change in the whole of the or- 
ganization, and fenfations have been diftinguifhed 
into three kinds. In the firft two, the change of ftate 
tends to difturb the habitual order of the func- 
tions^ or to favour it (gainful and agreeable fenfa- 
'iions)\ and in both thefe cafes an adlion is pro- 
duced on a part. A fenfation of pain or of ea- 
linefs is experienced in an organ. \x\ ftm^U Jen- 
fation there is {lill a general and inftantaneous 
change of flate ; but without perceptible altera*- 
tion in the natural order of the fundlions^ and 
though a fenfation is produced, the nature of the 
change which has taken place cannot be appre- 
ciated, nor is the feat of the fenfation known. 

There however can be no doubt that fimple 
fenfations arife frorn a general and inftantaneous 


pilGAlTS OP THE SEIfSfiS. 275 

^liange of ftatej and this change, which is not habir 
tually perceptible, becomes very appreciable when it 
has more intenfity. Thus, of the fenfations which 
we, receive by the eyes and the ears, when foine of 
them fuddenly recall a feries of ideas which intereft 
us in a lively manner, this change of ftate then be- 
comes condderable, and eafy to be appreciated. 

Under thefe different circumdances, a fenfation 
as if fomething liquid or cold were circulating 
throughout all the parts of the body is experi- 
enced ; a fenfation of fudden cold, of violent 
heat with perfpiration, or an oppreffion towards 
the epigaftrium are felt. Sometimes this derange- 
ment is fo fudden and ftrong, during extreme 
joy or a tranfport of paflion, that it may produce 
lyncope and even death. 

The phsenomena refulting from the habitual 
exercife of limple fenfations are commonly indir 
cated by faying : the influence of the moral part 
on the phyfical, which in regard to many perfons 
denotes the influence of nothing on fomething j 
but it is evidcjit that Ample fenfations, or fenfa-* 
lions unaccompanied with any remarkable de- 
rangement of the funftions, are of the fame 
order as thofe which are accompanied by changes 
in thefe fun61ions: they are all equally the refult 
of a new mode of action, excited in the .cere- 
bral organ, which product a general and in-^ 

T % ftantaneous 

27^ Vital functions. 

ftanlaneous change of flate in the whole of the or- 

46. To experience a fenfation, ' which may be 
conveniently compared and produce confcioufnefs 
of the change of ftate which has taken place in 
the organization, it is necellary, ift. That the 
cerebral fyllem fliould be found, and in full vi- 
gour : no diftindl fcnfation indeed is experienced 
in difeafes accompanied with a derangement of 
the cerebral organs. 2d. That the nervous com- 
munication, eftablifhed between this fyftem and 
the organ which receives the impreffion, fhould 
not be interrupted ; for if the nerves of one part 
be tied, cut, or palfied, the imprellions made on 
them produce no fenfations. 3d. That the organ 
fhould be in a particular Hate of adion which 
conftitutcs 'vigilance ; for to make a perfon hear, it 
is not fufficient that you fpeak to him, he muft 
alfo hear : it is to hear that the part enters into a 
fort of tenlion proper for that purpofe ; the cafe is 
the fame with the other organs, though in a 
manner lefs fenfible. When the organs of a 
perfon are not fufficiently diftended to perceive, 
it is faid that he is inattentive. 

All perceptions, experienced without thefe con- 
ditions, cannot produce confcioufnefs ; and the 
movements they occafion are not the refult of 



volition, but of the force of habit, in confequence 
of the new mode of aftion tranfmitted to the 

47. When the organs of the fenfes^ after long 
and fevere exercife, can no longer preferve that 
degree of tenfion necefiary for^ perception, they 
fall into a fort of collapfiis, and- pafs to a Hate of 
reft which conflitutes fleep. 

Sleep is not produced by the repofe of fome 
organs exclufively, but is the more complete ac- 
cording as a greater number are in that ftate of 
collapfus ; and it is to be obferved that almofl 
all the organs may be in a6lion in different Hates 
of lleep. 

Thus, the organs of loco-motion are in a6lioii 
during fomnambulifm ; and a perfon during fleep 
may be affected by the fenfes of fmelling, tailing, 
and touching. Some fpeak in their fleep, and if 
aflced any queftion they fometimes give a direft 
anfwer, which proves that they hear. The fenfe 
of feeing is the only one which does not per- 
form its fundlions during fleep in regard to ex- 
ternal objedls. The caufe of this feems to be, 
that the organ of feeing fuddenly procures a very 
great number of fenfalions at a time, which al- 
ways tend to awaken. It is well known that the 
organs of generation are often put into a£lion in 

T 3 the 


the time of fleep, efpecially during lafcivious 
dreams, and in the feafon of love. 

It is ahnoll needlefs to mention that the fanc- 
tions of the organs of circulation, refpiration, 
^nd digeflion, as well as of thofe of fecretion, are 
liot interrupted in the time of fleep. 
' Thofe adtions, which are the habitual refult of 
Recalled fenfations, may be produced daring fleep, 
by the force of habit, when that change or ftate, 
which generally conftitutes thefe fenfatlons, is re- 
newed in the brain by certain circumftaDces. 

Thefe adions. confift in a combination of re-* 
called ideas ; and foraetimes in the exercifes na- 
turally refulting from thefe ideas, as is oblerved in 
the Cafe of fomnambulifm and of dreams. 

7f the change of ftate, reproduced in the brain, 
be analogous to that which the optic nerves have 
made it already experience by the fight of any 
obj'cft, the individual will believe that he Itill 
fees it. The fame thing may take place in re- 
gard to the other fenfes. 

As a fenfation renewed may recall many others 
which have accompanied it, a fingle one may re- 
produce a feries of ideas, fometimes well arranged, 
and often very incoherent or ridiculous. 

If the change of ftate in the brain happens fud- 
denly to vary, the individual will immediately ex- 
perience another order of fenfations, ^hich may 



have no relation with the former ; and if thefe 
new fenfations are of fuch a nature as to affe6t 
him in a lively manner, they wmII determine the 
habitual a6lion of the organs : he will fpeak and 
even rile up to perform things agreeably to the 
ideas which are renewed. 

When a perfbn agitated by lively affections is 
afleep, the heat of the bed, an uneafy pofition, or 
difficult digeftion, may occafion a change of ftate 
in the brain, which will be fufficient to produce 

. It is obferved, casteris paribus, that fenfations 
which arc moft frequently renewed during fleep, 
are livelier and make a ftronger impreffion than 
thofe experienced while awake. 

48. To combine, properly, fenfations acquired 
in a ftate of watchfulnefs, the organs which per- 
peive, and the cerebral fyflem to which the im- 
preffion is tranfmitted, muft be in that perfect 
ftate of equilibrium which conftitutes health. 

If the fundlion of the cerebral fyftem be de- 
ranged or difturbed, it cannot properly perceive 
the fenfations received by the foundeft organ j 
and every thing will appear to have the im- 
preffion of that difordcr which prevails in the 

Such, in all probability, is the very fimple rea* 

fan of the derangements of the intelledual organ 

T 4 obferved 


obferved during paroxyfms of hyflerics, hypo- 
chondriafis, melancholy and mania; andofthofe 
obferved in a great number of difeafes. from the 
flighted dehrium to the mofl dreadful convul- 


49. It is to be obferved, that the changes of ftate 
which take place in the whole organization, in 
~ confequence of impreffions received, and the dif- 
ferent movements which thence refult, are of two 
forts : \ye have a confcioufnefs of the one ; and 
the others take place^ as we may fay, without our/ 

The changes of date of which we are confcious, 
are thofe only which can be agreeable or painful 
to us. 

Thofe which take place without our knowledge, 
are exceedingly numerous : fomeof them depend 
on the natural a(?i:ion of the parts ; of this kind 
are the movements of the different organs of cir- 
culation, refpiration, and nutrition ; but if we 
have no confcioufnefs of the habitual adion of 
Ihefe organs, we experience a very fpeedy fenfa- 
tion of their derangement : the reft comprehend 
thofe diforders which depend on a derangement 
of the cerebral f){lem ; they often produce acci- 
dents exceedingly dangerous, and even death, 
without our being confcious of them, as in the 
eafe of epilepfy, afphyxiee, apoplexy, &;c. 

" Thefe 


Thefe general conliderations on the fundlion 
of the cerebral fj-ftem, and on the different 
modes of fenfation, are fufficient to give a pretty 
corre(?i: idea of them. I fhall therefore not ana- 
lyie thein any further, as this would lead me to 
details in the more obftrufe parts of phyfialogy, 
which would be improper in an elementary work 
of this nature. ' 


[ 282 ] 


5©. 1 HE human body increafes, develops itfelf, 
is fupported and modified every moment, at the 
cxpence of the blood, which, in the uninterrupted 
courfe of circulation, furnifhes to every part of 
the organization the materials proper for the dif- 
ferent changes which are continually taking place 
in it. 

The blood repairs its lofles by the produd of 

The aliments, introduced into the digeftive 
organs, make their way through them in a flow 
manner. During their flay and their paflage 
they become penetrated with the juices fecreted 
by the mucous furfaces of the alimentary canals, 
and furniQied by the glands ; and they are gra- 
dually converted into a pafle of a homogeneous 
appearance, which contains the chyle. 

The chyle, taken up by the abforbent or chyli- 
ferous vellels of the famiC furfaces, becomes after- 
v;ards mixed with the venous blood. 

The fubftances fufceptible of being digefled^ 
are all thofc which arife from organized beings ; 
vegetable and animal fubilances, and thofe which 

7 "^- 


enter into the compofitlon of the fame fubftances j 
fuch as water^ atmofpheric air, &c. 

The exercife of the gaftric lyftem is excited by 
the painful fenfations of hunger and of thirft. 

When the need of ahments begins to be (dtf 
the individual firft experiences a difagreeable fen- 
fation, which announces that the gaftrio organ re- 
quires to be exercifed, and that it is difpofed to 
perform its function in a complete manner. This 
firft fenfation (appetite) is the beft feafoning for 
every kind of food. 

But if a perfon remains feveral days' without 
eating, he gradually experiences a fenfation of 
ardour and twitching towards the epigaftrium ; 
perfpiration decreafes, circulation and refpiration 
become flower, and the individual falls into a 
ftate of great weaknefs acconnpanied with anxiety. 
At length, if this ftate continue, it produces death 
after dreadful convulflons, and the body pafles 
Ipeedily to a ftate of putrefadtion. 

That need, called hunger, is ftronger the more 
active the life, and the more confiderable the lofles 
which the body fuftains : it is increafed at the ufual 
hour of meals, and by all thofe obje6ls which re- 
call the remembrance of aliments. It decreafes, or 
is inflantaneoufly fufpended, by every poMierful 
diftradlion ; by the prefence in the ftomach of in-r 
digeftible fubftances, and by compreffion of the 



. During hung-er, the ftomach, completely einpty, 
is contradtedj and becomes reduced to a very 
fmall volume» This ftate muft check circulation, 
^nd produce a painful reftraint in the nerves ; the 
jrefult alfo is that the liver and fpleen, being lef^ 
fupported, will twitch the diaphragm, and all 
ibefe changes '{till contribute to incrcafe the un- 

, A great many inftances are mentioned of abfii* 
Ijence continued for feveral months, and even 
for feveral years. This may be conceived in the 
following manner : When a perfon dies of hun- 
"gerj be does not perifh by being exhaufted in the 
fame manner as a lamp is cxlinguifhed for want 
©foil ; hut the ftomach^ the fun6tion of which 
requires to be exercifcd, produces during hunger 
a general diforder, which becomes fatal if it con- 
tinues. When the fenfation of hanger is not 
called forth, life may be continued a very long 
time without nouriOiment, as has been obferved 
in perfons who remain in a ftate of abfjlute reft, 
as hypochondriacs, maniacs, &c. The digeftive 
fyftem then fufpends its fundions, like a limb 
which is at reft; the fecretion of the fkin ftops ; 
and the flight lofs of heat and pulmonary perfpi- 
ration which takes place is fpeedily repaired, at 
the expence of the infpired air, and of a fmall 
quantity of drink. 
When thirft is fuddenly excited by exceffive 



lieat and abundant perfpiration, wben the animal 
fluids have not that quantity of aqueous parts 
which belongs to them, the fenfation experienced 
is much more painful and more infupportable than 
that of hunger. 

Third produces a ftrong fenfation of drynefi, 
of ardor, and of conftrid^ion in the fauces, with a 
burning fever, and fooner proves fatal than hunger. 
It is quenched with much more certainty by aci- 
dulous or alcoholized beverages than by pure 
water, even when iifed in a large quantity. 

In forced marches, during very hot weather, 
thirft mav be prevehted or allayed by moderate 
and frequent dofes of alcoholized liquors, vvhicli 
fupport the ftrcngth and excite the lecretion of k 
greater quantity of faliva. 

51. It has been obferved, that the hour of 
fneals, the fmell of ragouts, the appearance of. a 
covered table, or the noife of the diihes and the 
mention of favory aliments, excite and put ia 
play the gadric organs of gluttons and great eaters; 
the falivary glands already enter into ad:ion j fe- 
cretion commences, and their mouths begin to 

The aliments are firft cut and pounded by th<? 
teeth, and at the fame time are penetrated by the 
faliva, which flows in abundance, and the fecre* 



tion of which is maintained by the aS. of malli-' 
cation, and by the favour of the alimentary fub-* 

It is of importance here to remark, that mafli-* 
cation is effedled amidft a volume of atmofpheric 
air, which is compreiled and mixed with the ali- 
ments by the fides of the mouth ; the faliva by its 
vifcidity is exceedingly proper for retaining a cer^ 
tain quantity of it, and the albumen which enters 
into the compofitlon of the faliva abforbs alfo a 
part of its oxygen, fo that the alimentary fub- 
Hances are neceflarily mixed, during maftication, 
with a certain portion of air j and when people 
fwallow only their faliva it muft neceflarily carry 
with it into the ftomach a very large quantity of 

The aliments, properly pounded by maftication, 
and mixed with faliva and air, are afterwards col- 
le6led into a ball by the a6lion of the tongue. 
This alimentary bolus, comprefled by the lateral, 
parts of the mouth and the upper fide of the 
tongue againft the velum palati, is thrown back- 
wards, and pafies through the narrow part of the 
gullet, by pufhing the uvula againll the pofterior 
aperture of the nofirils. When it reaches the 
'hack part of the mouth, it experiences a- new 
prefilire ; it is comprefi!ed by the pharynx, and by 
acombine^ a^ion of the differeat mufcles of the 

throat : 


throat: it defcends behind the larynx, lower- 
ing the epiglottis, and pafles through the oefb- 
phagus, from which it is conveyed into the fto- 

The aliments when conveyed into the ftomach 
ceafe to be rubje6l to the laws of chemical affi- 
nity : they become entirely obedient to the vital 
powers, and exhibit in their digeftion a very re- 
markable feries of phcenomena. 

By their prefence in the gaftric organ they a6i 
as a particular irritant, which excites lecretion of 
the digeflive juices, and produces a contra(5lion of 
the ftomach ; fo that the gaftric juices, the preA 
fure of the lides of the ftomach, the heat and 
their refidence in a living organ, are the princi- 
pal caufes which concur to transform the alimen- 
tary fubftances into a homogeneous pulp, already 
in fome meafure animalized. 

Certain alimentary fubftances are more difficult 
to be digefted than others ; and though different 
ftomachs exhibit great variety in this refpec^, there 
are fome aliments, fuch as fat, which are ge- 
nerally of difficult digeftion. On this fubje6l 
we muft refer to the curious experiments which 
Gofie, of Geneva, made upon hi mfelf. 

When an obftrudion takes place in the pylorus^^ 

' the aliments which pafs only with difficulty into 

the duodenum, are often rejected by vomiting • 

the calibre of the inteftines then decreafes, and 



the fmall quantity of chymous matter, which flows 
thither, is generally well digefted. 

I have obferved, in the cafe of an obftraftion 
of the pylorus with vomiting, that as long as the 
intedines continue to perform their funftions, 
the upper part only of the patient's body becomes 
attenuated, while the lower half retains almoft its 
ufual plumpnefs. On the other hand, we fre- 
quently fee the lower parts of children, during 
a long continued loofenefs, though the ftomach 
digefts well, become conliderably wafled, while 
the upper parts retain their ufual Hate. Thefe 
two contrary obfervations are very remarkable in 
the hiftory of digeftion. 

The ftomach, after digefting the aliments it 
contains, is no longer llimulated in fo lively a man- 
ner by their prefence : its acflion then changes, 
and inflead of that ftrong contra61ion which it 
exercifed on them, it performs a regular motion 
(the ferijialtic), which diredls them towards the 
orifice of the pylorus, and makes them pafs into 
the duodenum. This large and fhort inteftine, 
affixed to the vertebral column only by a loofe 
cellular tiffiie, and no ways fecured by the peri- 
tonfeal membrane, is fufceptible of very great 
extenfion : it may with great propriety be con- 
lidered as a fecond fi;omach, in which is perform-, 
ed a digeftive atStion, no lefs important than that 
which takes place in the real ftojmach. 



- ' 'The chymous matter, accumulated in the duor 
denum, irritates this inteftine, which contrads and 
■fecretes an abundance of digeilive juices. 

The prefence of the alimentary fubliances in 
the duodenum excites the adlion of the panc.reas, 
as well as that of the liver; the produ6l of their 
lecretion is efFufed in greater abundance in this 
inteflinCj and being mixed with the aliments con- 
tributes to complete digeftion. 
. , Xhe fluid fecreted i^y the pancreas is entirely 
fimilar to faliva. 

The bile ought to be confidered as a parti- 
cular excretion of the liver, which in being eva- 
cuated ferves for digeftion, rather than as a fluid 
fpecially produced for the fervice of that func- 

The veflels which bring back the blood from 
the ftomach, the epiploon, the inteflines, the mc- 
fentery, the pancreas, and the fpleen, unite into^ 
three principal trunks (the great and Jmall fplenic and 
the mef enteric), which are foon confounded into one 
vein (the Juh -hepatic or 'Vena portce). This arterial 
vein penetrates into the liver towards the middle 
of its tranfverte fciffurej divides and fubdivides it- 
felf there in an indefinite manner, and the blood 
which it thus conveys to all the parts of that organ, 
begins to afTume the qaaliuea necetlary for be- 
coming again arterial blood : it fiees itfelf from a 

VOL. m. u part 


part of the hydrogen and carbon which are con- 
tained in it. 

The refult of this particular excretion is thfe 
bile^ a fat fluid, which by its mixture with a fmall 
quantity of foda forms a faponaceous liquor, eva- 
cuated by peculiar veflels. 

The liver, therefore, mufl: not be confidered as 
peculiarly deftined to fecrete the bile, but as an 
organ in which the blood begins to refume new 
vital properties, by freeing itfelf from the fuper- 
fluous matters it contains. How, indeed, is it 
poffible to conceive that a moft voluminous organ, 
which occupies a great part of the abdomen, 
fhould be deftined merely for the fecretion of a 
fluid, much lefs in quantity than that produced 
by a kidney or by one of the breafts ? 

This produft of excretion, however, is not 
evacuated without contributing towards the or- 
■ ganic fundions, and il becomes one of the moft 
powerful inftruments of digeftion. The bile is 
fo neccflary, that when it ceafes to flow digeftion 
is completed with difficulty ; the chymous fub- 
flance becomes dry, remains colourlefs, obftrudts 
the inteftines, and an obflinate tenefmus takes 

The bile is formed by the venous blood which 
returns from the greater part of the vifcera of the 
abdomen; but as this blood does not circulate 



with great a(5livlty, and as its progrefs is checked 
during different circumftances of digeftion, it ap- 
' pears that the fpleen is deftincd to fupply the liver 
Ipeedily with venous blood, which enfures the 
fecretion of the bile. 

Hence it is feen, that every thingin the or- 
ganization is employed in an economical manner,- 
and that no power is lofi:. The excretion of the? 
bileferves for digeftion, as the excretion of the 
Ikin for lowering the temperature by evaporation ; 
and as air expelled from the lungs ferves for pro- 
ducing voice, &c. 

The biliary veflels decreafe in number, increafe 
in fize, and at length unite into a du6l f:(be he- 
patic), which proceeds towards the duodenum. 
In its paflage, this du6l communicates with ano- 
ther, called the cyjiic^ which proceeds into the 
gall bladder, where the bile may be accumulated, 
and remain a longer or a fhortcr time. 

The prefence of the aliments in the duodenum 
excites the a6lion of the liver, and even that of 
the gall bladder ; the bile flows from the hepatic 
du(?t and from the cyftic ; thefe two du61s termi- 
nate at a common du6t (ihe duBus choledoclms)^ 
\vhich proceeds into the duodenum, two inches 
from the pyloruF, and very near the apeiture oi 
the pancreatic ^wS, : thefe two duels often unite, 
and are confounded before they enter into the 

u 2 The. 


The chyfnous matter, prefTed by the fides of the 
duodenum, penetrated by its juices, and moiften- 
6d by the pancreatic liquor, and by the bile which 
ftimulatcs that organ, acquires at length the ul- 
timate degree of animalization, and forms a pulp 
^vhich contains the chyle completely formed. 

The alimentary fubftances, after this duodenal 
Sigeflion, proceed flowly along the fmall intef- 
tines by the perifialtic adlion o{ thefe parts. Dur- 
ing this paffage, the digeflive a6l;ion continues 
to operate ; and the chyle, which is feparated 
from the reft of the chymous mafs, is abforbed by 
the numerous open mouths of the chyliferous 
veffels, with which the fur faces of thefe inteftines 
are covered. 

At length, the alimentary fubflanccs pafs into 
the large inteftines ; the abforption of the chyle 
and of the aqueous parts, which they contain, 
continues to take plp.ce ; they acquire more con- 
ftftence, are moulded into the form of the intef- 
tines, and reach the rciflum, from which they 
are afterwards protruded. This pfotrufion is ef- 
fe6ted by the combined adiion of the fides of the 
re6ium, and of the abdominal and diaphragma- 
tical mufcles, which overcome the refiftance of the 
iphin6ler, and expel thefe ufeltfs fx^ces. 

52. The chyle, after being abforbed by the 
mouths of the chyliferous ve(iels, foon proceeds 



into the glands, where it ftill undergoes a peculiar 
affimilation. It iflaes from thefe glands by larger 
and lefs numerous veflels, which afterwards proceed 
into a duel (the thoracic), fituated in the pofterior 
part of the thorax, and communicating with the 
left fub-clavian vein. This du(5l for the mod part 
has a dilatation (refervoir of the chyle), at the 
place where the lymphatic and chyliferous veflels 
terminate. That on the right fide is much fmaller 
than the one on the left. 

It mufl: not be imagined that the whole pro- 
duct of nutrition proceeds into the thoracic du6l : 
this pafTage is very apparent, but there are a thou- 
fand which efcape our eyes, and through which 
the chyle may be conveyed to mix with the blood. 
It is well knovi^n alfo, that nutrition is not inter- 
rupted by a ligature of the thoracic du6l. This 
du6l mufi: be confidered as the principal artery of 
a limb, the lize of which is much lefs than that of 
all the collateral arteries united. 

53. Digefiion is one of thofc organic functions 
which has the greateft refcmblance to a chemical 
operation ; yet it differs eficntially from it in its 
principal phienomena. Whatever, therefore, be 
the nature of the alimentary fubftances employed^ 
whether thefe fubflances be vegetable or animal, 
green, frefh, or in an advanced ftate of putre- 
fadioUj boiled or raw^ dry or exceedingly fluid, 

u 3 mixed 


mixed with aqueous, acid, or alcoholic liquids ; 
whether one fort of aliment or a great number 
be ufed, and though -mixed in all proportions pof- 
fible, they always give for refult, in a found and 
"vigorous ftomach, a chymous fubftance, nearly of 
the fame quality ; and in this fubftance the nature 
of the aliments, which have concurred to produce 
itj c^n no longer be known. 

Digeltion, conlidcrcd under this eflential point 
of view, has no refemblance to any of the knov^'n 
phaenomena of chemiftry ; it is entirely owing to 
the particular vital powers, and to that affimi- 
lating power which is found only in organized 

The operation of digeflion produces in the fto- 
mach a very energetic centre of aftion, where all 
the powers fcem to terminate. During this pro- 
cefs, circulation and refpiration are increafed ; 
and a very remarkable fliivering is experienced. 
The other lyftems of organs remain then in a fort 
of proftration, and exhibit great inaptitude for the 
exercife of their Cundlions. Reft', therefore, is 
the ftate moft proper to be in during this opera- 
tion ; and it is that indeed which, on this occa- 
iioo, all animals aftlime. 

When ftomachic digeftion is nearly terminated 
the fhivering ceafes, the pulfe becomes flower 
and fuller, and a flight perfpiration takes place. 
During the procefs of digeftion, the principal 



phaenomena of a febrile paroxyfm are, ther^forcj, 

It is not merely in the gaflric organs and along 
t|;^e inteftinal canal that digeftion may be efFe6led; 
fubflances fufceptible of being digefted underga 
that procefs in every part of the organization. 

Thus, a portion of animal or vegetable matter, 
introduced below the fkin, or into the fubftance 
of the fleth, may be there digelled, and at length 
entirely difappear ; air injefted into the cellular 
tifTue, and liquids introduced into or effufed in 
the cavities, may alfo be digefted and abforbed. 
It is by a real digeftion that bloody, purulent, and 
lymphatic colledlions, emphyfemala, different tu- 
mours, and even calculi difappear. In all thefe 
cafes, the a(51ion of the living liquids and of the af- 
limilating power is every where obferved. The 
organs make a continual effort to decompofe the 
foreign fubftances with which they are in contact; 
lince they abforb the materials fuited to them, 
and reject the relt, either by the ufual paffages 
of excretion, or by a feries of phlegmalic phe- 

It is probable, that when fubftances are reduced 
to a very minute ilata the digeRion of them is 
much eafier : thus it is well known, that but*, 
chers who lead a life of repofe amidfl frefh meat 
are in general fat and florid. The moleculas of 
the animal fubftances, which evaporate^ are con- 

u 4 ' veyed 


veyed with the infpired air into the lungs, where 
they experience an cafy digeftion. 

We fhall have occafion more than once to fliow, 
that a funsftion which is exclulively afcribed to 
one 1} flem of organs, may be performed in feveral 
other parts. 

54. When digeftion is completely effecled in 
vigorous gafiric organs, no difengagement, of gas 
or development of acid or alkalies are obferved : 
the aliments are completely digefted, without 
emitting a putrid odour ; and the breath retains 
its natural fweetnefs. But in a weak individual, 
the gaftric fjtiem, being more or lefs debilitated, 
does not perform its fundlions with the fame 
energy. The aliments then, which are not en- 
tirely fubjeQ:ed to the vital influence, are in the 
fame flate as if they were enclofed in any other 
place equally humid and warm ; and chemical 
phjsnomena, more or lefs modified by the exifting 
vital aftion, are obferved : hence there is a difen- 
gagement of carbonic acid gas, of the gafeous 
oxide of carbon, of fulphurated hydrogen, &c. 
and a development of acid or alkaline matter. 

Thefe phenomena are frequently obferved in 
febrile difeafes, and in a peculiar manner in ady- 
namic fevers^ attended with extreme profiration 
of ftrength ; and when the powers are very much 
cxbaufled. The aliments, left almofl entirely to 



themfelves, fpeedily become putrid, emitting an 
odour fo infcflious, that this phaenomenon has 
been confidered as an eflential lymptom and- a 
caufe of thofe fevers, which have retained the 
nanae o^ putrid; but this putrefaction is only a 
natural confequence of the flate of debility to 
which the gaftric organ is reduced, and of the re^ 
lidence of the aliments in a humid and warm 

55. Having.conlidered the aliments as a fub- 
ftance proper for furnifhing a repairing produd:, 
and having examined the principal phaenomena 
by which the digeftion of them is charaderized, 
it will be proper to examine them under a point 
of view no lefs important, and to obferve what 
is their a6lion, in general, on the whole nervous 

The fubftances introduced into the ftomach al- 
ways produce on the nerves of that organ an im- 
preffion of contact, which may occafion a general 
or peculiar change of fiiate, more or lefs appre- 
ciable. Hence fubfiiances introduced into the 
alimentary paflages, all aft as particular Simulants, 
whether they be fufccptible of digeition or not. 

In regard to their ftimulating action, the na- 
ture of the aliments is not a matter of indiirer- 
cnce ,to the organization. On the contrary, the 
aliments produce confiderable changes in the 



whole lyftern, according to their peculiar quality, 
independently of the quantity of nutritive parts 
which they furoifh. What a difi^rence therefore 
muft exift between people who feed on vegetable 
fubftances and who drink water, and thofe whs 
live upon flefli and who ufe fermented liquors I 
The latter always poflefs more ftrength and more 

It may be readily conceived that the action of 
medicines is founded entirely on this property, 
which foreign fubftances have, of producing a 
change of Hate in the organization. 

A great part of medicines are nothing but ali- 
ments, the ftimulating aftion of which is more or 
lefs energetic, as is the cafe with all medicinal 
preparations extrafted from vegetable or animal 
fubftances. Others are obtained from bodies little 
fufccptible of being digefted, but which pofiels a 
greater or lefs irritating aftion, as faline fubftances, 
metallic oxides, &c. : in a word, fome nutritive 
fubftances produce their medicinal efte£l only 
when they cannot be digefted, as is the cafe with 
manna, oils, &c. which purge merely by indigcf-^ 
tion : when the ftomach has fufficient power to 
digefl: them, they no longer produce the fame 

Subftances introduced into the alimentary paf- 
fages exercife their aftion in one general modej 
ibat isj by ftimulating the nervous adion. This 



flimulating afliion is then varied, according to the 
nature and dofe of the fubftance employed ; ac- 
cording to the peculiar difpotition, habits, and 
greater or lefs fenfibility of the gaftric lyflem, in 
particular, and of the nervous fyflem, in general. 

The caufe of the particular action of fubftances 
on the nerves, which depends on their nature or 
intimate compoiition, is entirely unknown; and 
we are unacquainted with the relation which exifts 
between the compoiition of a fubflance and its ac- 
tion on our organs. 

The a&ion of fubftances is fufceptible of varia- 
tion according to the dofe. A glafs of wine gives 
a very agreeable ftimulus to the whole iyftem, and 
facilitates digeftion ; while feveral pints derange 
entirely the nervous adlion. 

The action of a fubftance is very different, ac- 
cording as we are in a ftate of health or of difeaie, 
and according to the nature of the derangement 
with which we are afFedcd. Opium, which pro- 
duces violent efFefts in moft acute difeates, though 
admmiftered in fmall quantity, may be given in 
very large dofes in tetanic afFedlions. 
^ The habit which the gaftric lyftem contra6^s of 
receiving the fame fubftances, greatly diminifhes 
their a6lion, and people, by continued ufe, may 
accuftom themfelves to the ftrongefi things. 

The a6tion, which depends on the compoiition 
of fubilances, ceafes in proportion as they are de- 



compofed by the digeftive force of the ftorhach ; 
and this a(5Jion is null when they are fpeedily di- 
gefted : hence the reafon why a great number of 
fubtlances, which produce a (Irong a6^ion on a 
part deftitute of epidermis, exercife none on the 
itomach . 

In general, the refult of the a61ion of a fab- 
ilance is conlidered as its primitive or dire6l ac- 
tion. Hence it is faid that the warm water which 
excites vomiting, and opium which produces an 
agitation often very ftrong, weaken and debilitate; 
becaufe the confecutive efFe6l of the firil ftimu- 
lating action is to leave the organs in a fiate of 
extreme debility. 

The impreffion mj^de on the llomacb produces' 
the fame teries of phsenomena, as if it were made 
on any other organ : it oecations a change of ftatCj 
for the moft part remarkable in the gaftric fj'flem, 
fometimes more fhriking in a diftant organ, or 
fenfible in the whole of the organization. Thus, 
fome fubfiances exercife their principal action on 
the ftomach itfelf, and favour its function ; of 
this kind are alcoholized liquors : others manifeft 
their acilion on particular organs, fuch as the kid- 
neys, the Ikin, Sec. and on that account are faid 
to have a fpecific a6tion ; fome alfo produce a de- 
rangement in the whole of the parts, as is the 
cafe' with thole which are poifonous. 

From thefe general conii derations it may be 
5 readily 


readily conceived how difficult it is to determine 
the adlion of the different fubftances conveyed 
into the ftomach, the -number of the caufes by 
which it may be varied, and what opinion. ought 
to be entertained, in general, of medical fuh^ 

56. What relates to medical fubdances is an 
€bje6l of too much importance not to engage our 
attention for a fevv moments. Medicines, in ge- 
neral, are ciafied according to the efifec^ which 
they produce, and a great number even accord- 
ing to that which they do not produce. 

A man void of medical knowledge, who only 
cafls his eye over the properties aferibed to medi- 
cines in a Materia Meclica^ muft believe that the 
medical art has attained to the higheil degree of 
perfeclion ; fince it pofielTes remedies which ex- 
ercifc an aftion in every manner poffible. But 
thofe who have pradiifeci for tome time will ibon 
be convinced, that the wonderful qualities of thefe 
medicines very often exill only in the pompous 
names with which they have been decorated. To 
be convinced of this truth, nothing will be necef- 
fary but to run over the claffification in fome of 
the beft works on the Materia Medica, fuch as 
that of Cullen. 

This phyfician has arranged all the. medical 
■fubiiances into twenty-GlaiTes, fome of which com- 


prebend fubftances faid to a61 on tbe fluids, and 
others on tbe foHds ; as if fabftances could afl 
in any other manner than on tbe nerves and 

I ft. The mdrittve, are common aliments, and 
every thing that can be digefted is nutritive. 

2d. The ajirlngent^ are particular ftimulants, 
which produce a conftridtion of the parts to 
which they are applied. 

3d. Emollients, which eflentially are warm 
aqueous fubftances. It cannot be faid that their 
iirft a6lion is debilitating, fince the prefence of 
warm water in the llomach excites vomiting or 
occalions perfpiration j but when thefe fubflances 
have exercifed an action for fome time, they pro- 
duce a ftate of relaxation and of evident weak- 

4th. Slimulauts, are all thofe fubftances which, 
when applied to the organs, exalt their ai5iion. 

5th. Sedatives, are alfo ftimulants, which firft 
produce a confiderable exaltation of the nervous 
adlion, and exhauft or derange it to fuch a degree 
as to bring on fleep. Of this kind arc opium, 
wine in ftrong dofes, poifons, epidemic miafmata, 
and cold. 

6th. Antifpafmodics. Spafms being the confe- 

quence of exalted nervous a61ion, every thing that 

tends to put an end to that exaltation is antifpafmo- 

dic. Exaltation of the nervous adlion, in any fyftem 

7 ^^ 


of organs, Tiiay be deftroycd either by changing 
that adion, or by producing a ftronger in fomfc 
other part; and in all thefe cafes the antifpafmodics 
muft be flimulants. 

Bleeding is the beft antifpafmodic ; but it is 
not a medicine. 

7th and 8th. Attenuanfs and mfpijfayits, are me- 
dicines fuppofed to have an exclulive adion on 
the fluids, to give them more li<|uidity or confift- 
ence. It is certain that drinking for a long time 
•in profulion, or the contrary excefs, mull caufe 
the conliftence of the fluids to vary ; but this 
efFe<5t is only a very unimportant refult of the 
ufe of liquid or folid medicines, the principal ac- 
tion of which is exercifed on the nervous lyftem. 

9th. Lenhnts mean nothing, and ought to be 
confounded with emollients. 

loth and nth. Anti-acids and anfi-aJkalks 
produce the effedt afcribed to them, merely by 
adling on the products of fecretion, and not on 
the fecretory organs. Thus pure magnefia, con- 
veyed into the ftomach when it contains acidities, 
can combine with them and form a fait, which 
afts afterwards as a flimulant. But the real anti- 
acids and anti-alkalies are all thofe ftimulants pro- 
per for reftoring to the organs the ftrength ne- 
cefll^ry to enable them to perform their fun^lions 
completely, and to prevent the development of 
acid or alkaline productions. 



■ iiXh. ^htifeptics. Septicity depends in ge- 
neral on a vveaknefs of the vital aflion, which 
permits the parts of our bodies to exhibit fome 
phcenomena of decompofirion ; and it may ftill be 
readily conceived that the only efficacious anti- 
feptics are Xhejiimuhnts. 

The lad eight clafles, denoted under the name 

of errhines, Jialagogues^ expedorants, emetics, ca" 

iharlicsy diuretics, diaphoretics y enienagogues, are 

.merely ftimulants conveyed to a particular part, or 

which exercife a fpecific a6lion on certain organs. 

From this curfory view it is feen, that all thefa 
twenty clafles of medicines may be reduced to 
flimulants, the mode of a6iion of which is ex- 
ceedmgly varied^ and fome of which indirectly 

Though medicines are thus reduced to a ge- 
neral a£tion, the choice of the moll proper reme- 
dies in the different cafes of difeafe is never a 
matter of indifference, and none but the fkilful 
pra6litioner can determine properly in what man- 
ner they ought to be employed. 

57. To fum up in a few words the whole of 
what has been faid, we muft confider, in the func- 
tion of the gaftric apparatus, ift. The digef- 
tive adion of the organs on the aliments: 2d. 
The (limulating aclion of the aliments on the 




in regard to the digeftive aflion, we obferve 
that the aliments are digefted by their mixture 
with the fecretlons of the falivary glands ; of thofe 
of the ftomach, of the inteftines, of the liver and 
the pancreas, and by their relidencfe in a living 

When this funftion is completely difcharged^ 
it exhibits no analogy to chemical operations : 
but when the ftomach begins to be weakened real 
chemical phaenomena^ which refult from the fimul-' 
taneous influence of the vital and of chemical ac- 
tion, take place. The chyle contained in the 
produ6l of digeftion is abforbed by the mouths of 
the chyliferous veflels, and pafles into the glands, 
where it undergoes an ultimate affimilatioh : it 
then proceeds to niix with the blood through dif- 
ferent pafTages, the moft remarkable of which is 
the thoracic dud, coilneded with the left fub- 
clavian vein. 

In regard to the ftimulating aclion of the ali- 
ments, feveral priucipar fads are obferved. The 
aliments have a great influence ori the whole of 
the organization ; and hence it happens that peo- 
ple who feed upon flefli, and who life fermented 
liquors, are much ftronger and more vigorous 
than thofe who live' only on vegetable llibfl:ances^ 
and who drink nothing but water. 

The whole adlion of medicines is founded 
merely on the ftimulating property of the fab- 

VOL, III. S ftans^ 


fiances conveyed into the alimentary pafTages * 
this action continues until the fubftance is digefted j 
or thrown out. *€!- 

The Materia Medica poflefles ftimulants ex- 
ceedingly various, fome of which indiredlly de- 


[ 307 ] 


58. The blood, taken at Its departure from the 
heart, is diftributed to ail the parts of the body 
by means of the arteries, and returns by the veins, 
to the right fid^ of that organ. To be conveyed 
then from the right to the left fide of the heart, it 
diftributes itfelf entirely to the lungs. 

In this manner the blood continually performs 
a double circulation ; namely, a general circulation 
in all the parts of the body, and a particular cir- 
culation in the pulmonary organs. 

We (hall examine the pheenomena it exhibits 
in this progrefs. 

59. The blood returns from the lungs by four 
veins, which proceed into the left auricle of the 
heart ; this auricle, by its contra6lion, drives it in. 
part into the ventricle on the fame lide, and this | 
ventricle forces it into the aorta. The blood can- 
not return from the ventricle to the auricle on 
account of a valve (the mUral) which oppofes it; 
and it cannot flow back from the aorta to the ven- 
tricle, becaufe it is ftill prevented by the iygmoid 

X 2 The. 


The blood which returns from the lungs is of 
a beautiful fcarlet red colour; it is florid, fpumous, 
Ibniewhat warmer than the venous blood, and 
therefore exhibi.ts all the charaiflers of arterial 
blood. Being continually expelled from the ven- 
tricle and the aorta, by the adtion of the auricle, 
it is diftnbuted to every part of the body, where 
its circulation is continued by the contra6lion of 
the arteries through which it pafles. 

The contra<5^ile force of the heart and of the 
arteries is maintained by the nervous a61ion of 
thefe organs, and by the prefence of the blood 
which flows thither. 

The force with which the heart contrafls has 
never been eftimated in a fatisfa6lory manner. 

The movements of the arteries are ifochronous 
with thofe of the heart ; thefe movements feem to 
be inflantaneoufly tranfmitted by the fluid of the 

The beats of the heart and of the arteries are, 
owing to alternate movements of dilatation (dia- 
JloJe), and of contra61ion (Jvfiole). 

The motion of diaftole feems to arife not only 
from the development of the tides of the arteries, 
but alfo from a flight difplacement of thefe 
veflels. - 

The motion of the heart and arteries is per- 
formed with fo great velocity, that in adults they 
make about 80 pulfations in a minute. This 



nurabep varies afterwards at the different periods 
of life, and in the date of difeafe. During the firli 
years of lifcj the pulfe beats- 130 and 140 times 
in.a minute; but this number decreafes with age;, 
and in old perfons it fcarcely gives 60 beats. In 
difeafes, when the whole body is affected, ' it may 
be readily conceived ^ that the nervous a6lion of 
the iyftem of circulation muft be deranged, and 
that this derangement manifefts itfelf in the ftate 
of the pulfation. 

The pulfe, in general, exhibits the fame cha- 
racter in the fame afFeCiions, and may ferve as ah 
indication of them to the phylician, who has been 
long habituated to this kind of obfervation. But 
the advantages derived from confulting the pulfe, 
in difeafes, has certainly been much exaggerated. 
The arteries, in diftributing themfelves to every 
part of the body, ar© divided and fubdivided in 
an indefinite manner, exhibiting frequent anafto-^ 

The fum of the fmall arteries is always m_uch 
fuperior in capacity to the aperture of the trunk 
which furnifhes them ; fb that the circulation 
mufl be lefs rapid in the rarni than in the ar- 
terial trunks. 

If the courfe of the arteries be traced out, they 
will always be feen to furnifh fubdiviiions ; the 
blood gradually feems to lofe its red colour, and 
nothing is obferved, but white veflels of the ut- 

X 3 vnoi\ 


moft tenuity, which at laft efcape the eye, even 
when aflifled by the beft microfcope ; fo that the 
mode of termination of the arteries is Itill un- 

It is proper here to remark, that animalcula, 
,the fize of which does not exceed the three or 
four hundredth part of a line, may be diftindtly 
ifeen by the microfcope. Thefe animalcula, which 
increafe, feed, and propagate, have in all probabi- 
lity veflels, the fubdiviiion of which is very great. 

If we fuppofe that each point of our body ex- 
hibits an organization equally perfect, and as com- 
plex as that of thefe animalcula, which is confirm- 
ed by microfcopical obfervation, we fhall then be 
enabled to form fome opinion refped^ing the ter- 
mination of the arteries ; the fubdiviiion of their 
capillary tubes ; and the ftate of divifion in which 
the blood mull be when it attains to that point. 

From various obfervations, however, there feems 
to be reafon for believing, that the arteries unite 
diredlly with the veins, and that the termination 
of the one is confounded with the origin of the 
other. What feems to be certain is, that the ar- 
terial blood may eafily pafs into the veins, and it 
proceeds thither with more eafe according as the 
life is lefs adive. ThuS, when blood is drawn 
from an animal by an aperture made in a vein, this 
fluid iffues, at firft, with all its charaders c-' venous 
blood ; but in proportioa as the animal becomes 



weaker, the blood gradually aflumes the arterial 
charadler, and feems at length to pafs from the 
arteries into the veins, without having undergone 
any change. 

But, however this may be, it is in the interval 
between the period when the blood efcapes oiir 
eyes through the arteries, and that when we begin 
to fee it return by the veins and the lymphatic 
veflels, that the mod important phaenomena of 
life take place. It is during this infinitely fmall 
fpace, that- the different changes, continually 
going on in every part of the organization, are 

The arterial blood, which is in a Hate of ex- 
treme divifion, reduced to vapour diiiclved in ca- 
loric, exhibits in this manner materials proper for 
all the fecretions. 

If the nerves continue to diflribute to the or- 
gans the principle of adion, neceflary for the ex- 
ercife of their fun6tions, the phaenomena of life 
may then be completely performed, and in differ- 
ent manners,- according to the particular flrudlare 
of each organ of fecretion. Thus the faliva is 
lecreted in the falivary glands, the milk in the 
breafts, the urine in the kidneys, the fluids at the 
furface of the ferous and mucous membranes, the 
fat in the cellular tifTue of all the parts : it is pro- 
bable allb, that the fluid which circulates in the 
■.::v;:-;-i '';. • X4 nerves. 


nerves, and which conveys every where Hfe an4 
fenlation, is fecreted in the brain ; and hence the 
vafcular and nervous fyftems are continually in a 
ilate of mutual dependence. 

The blood contains none of thefe produ6ls 
completely formed ; but it prefents materials pro- 
per for eompoiing them. 

When the arterial blood is difiiribated to an or- 
gan, the fun6iion of which is active, it undergoes 
very ftriking changes, and returns to the fiate of 
venous blood and of lymph ; but if the nervous 
a6lion on this organ be fo weak that it does not 
properly difcharge its function, the blood then 
pafTcs from the arteries, into the veins, almoit 
without having undergone any changes. 

It is well known that all the organs are com- 
pofed of a tilTne of veifels and nerves differently 
arranged, and in the interfaces of which are depo= 
fited fubftances of different natures and denfities, 
and that the veflels and nerves themfelves exhibit 
the fame compofition. 

The iiiollecuiss of matter, which compofe all 
thefe organic tiffoes, are continually experiencing 
changes : one part are inceffantly removed, and 
their place is fupplied by others^ which gradually 
afiiime a different arrangement. During thefe 
continual changes, the repairing molleculse in- 
creafe always in denlitj and number ; fo that the 

5 . 


©rgans gradually lole. their pliablenefs andytheir 
mobility, which in the courle of time neceflarily 
becomes a caufe of death. 

60. Amidft the continual changes which ia%^ 
place in every part of the organization, it mufl be 
oblerved that the fubllances excreted exhibit, in 
general, a greater denfity than that of the materials 
which ferved Xo produce them ; or, in other words, 
that the fubflances which iflue from our bodies 
have more confiflence than thofe which enter 

Thus we are continually lofing by pulmonary 
and cutaneous perfpiration, by urine and the other 
particular excretions ; and thefe lofles are repaired 
by the organs of digeilion and refpiration. 

The materials which efcape by the different 
paflages are, in general, carbonic acid gas (the 
heavieft of all. the gafes) ; liquids charged with 
falts, acids, albumen, gelatin, &c. and fat fub- 

The materials abforbed are: in the lungs, oxy- 
gen, and probably a little azote ; in the gaflric 
fyftem, the chyle, the product of digeft ion properly 
fo called, a great deal of water in the ftate of va- 
pour, and confequently very pure, and probably 
air alfo introduced into the ftomach. 

But it is evident that, lince the fubflances ab- 


ibrbed have much lefs denfity than thofe excreted, 
there muft be a difengagement from them of ca- 
loric ; and this difengagement is the caufe of ani- 
mal heat. 

Thus the heat difengaged from the different 
parts is a refult of the changes of denfity which 
the fluids continually experience in the different 

The quantity of caloric difengaged is in the ratio 
of the adivity of the organic funftions ; and this 
activity depends on the intenlity of the vital force, 
©r nervous aftion, to vi^hich all the phsenomena of 
the organization may be referred. 

The nervous a6lion of the organs of fecretion is 
maintained or excited by all flimalants, and even 
hy the exercife of their fundions. 

When an organ is ftrongly excited, it becomes 
St centre of adlion ; the blood flows thither in abun- 
dance, and fecretion is ef?'e(?tcd with great a6livity. 
When the organs of fecretion are not thus excited, 
or put into a6iion, their functions flag and may 
©ven ceafe entirely. 

6i. The blood, after being diftributed to every 
part, and after having furnifhed to each point of 
the oganiz^ation the materials neceffary for its par- 
ticular fecretion, returns by two orders of veflels, 
the veins and the lymphatics. 



The veins bring back all that part of the blood 
which has undergone the leaft change: that which 
retains a red colour. 

The lymphatics colle6l the products of all the 
feroiis fecretions, which are continually renewed, 
and all the aqueous parts, which hold in folutioa 
or in lufpenfion the remains refulting from the 
continual changes efFe6led in all the organs. 

The vemSj at firA exceedingly fmall, foon unite 
to form more apparent ones, and thefe continue to 
join, exhibiting frequent anaftomofes. The ra- 
raufculi by their union form rami, the rami 
branches, aod the branches trunks, which termi- 
nate in two large veins. One brings back the 
blood from inferior parts of the body (the vena 
cava inferior J, the other brings back that from the 
upper part (vena cava fuperior), and both proceed 
into the right auricle of the heat. 

The veins, as they unite, always decreafe a little 
in lize ; {o that the diameter of a venous trunk is 
always fmaller than that of the rami which con- 
curred to produce it. By this difpofition, the 
blood muft circulate quicker in the trunks than in 
the branches. 

The veins, at certain diftances, are furnifhed 
with valves, formed by folds of their interior tunic: 
thefe valves are generally difpofed in pairs ; they 
prevent the return of the blood, and interrupt the 
continuity of the fluid in thefe veflels. 

7 Th« 


The veins which bring back the blood from any 
jpart, are ahvays more numerous and of a larger 
fize than the arteries which carried it thither; an4 
this necefTarily renders the- venous circulation 
ipuch flower than the arterial. 

The blood circulates in the veins by the con- 
traftile force of their fides, affifted by the tonic 
a6lion of all the neighbouring parts. This circu- 
lation is maintained by the nervous a6tion of the 
veins, and by the prefence of the blood which 
Sows. into their cavities. 

The lymphatic veflels, much more numerous 
and fma.ller than the veins, are difperfed in abun- 
dance throughout all the parts, and particularly in 
the white organs, of vi'hich they feem to form the. 
whole tiiTue. They abforb the ferous liquids con- 
tinually fecreted in the different parts. 

The lymphatics, by their numerous diflribution, 
form an inextricable fort of reticulation: they 
unite like the veins to form larger and lefs numer- 
ous veflels. Like the veins, they are provided with 
valvular folds, generally difpofed in pairs, which 
oppofe the return of the lymph. 

After a certain pafTage, the lymphatics proceed 
into the glands, the aggregate of which forms an 
effential part of the abforbing 1}' Item. 

Thefe glands are fmall, round,^ or ovoid bodies, 
reddifhj arranged in groupes, and which have the. 
appearance of grains or feeds united. The lym- 


pliatic glands are obfervcd, in particular, in the 
bend of the great articulations, on the mefentery, 
and along the large blood veffeis. 

The lymphatics which proceed to thefe gland's 
lofe themfelves in their fubftance. The lyraph- 
vvhich they carry thither undergoes a particular 
kind of affimilation ; it then begins to refuma 
thofe charaders of animalization which it feemed 
to have left, and iiTues from them by another 
order of veflels, lefs numerous and larger. 

The lymphatics' thus continue to advance to- 
wards the thoracic du6l, uniting to Yorm larger 
veflels, and traverfing the glands which they meet 

All the lymphatic veffeis proceed, in this man- 
ner, to the thoracic .dud:. Thofe which come 
from the lower part of the body proceed into the 
abdomen^ unite with the chyliferous velTels, and 
proceed together to the lower part of the thoracic 
dudt. in this place, which is fituated near to the 
upper part of the abaomen, this du<Sl often exhi- 
bits a dilatation, more or lefs flrikiijg (refervoir of 
the chyle): it then traverfesthe diaphragm with the 
aorta, and afcends on the right lide of that artery, 
as far as the fummit of the thorax ; it then runs on 
the left, pailing before tke vertebral column, and 
proceeds into the left fubclavian vein. 

The lymphatics which come from the upper 
part of the body proceed fo different points of the 



thoracic du6l, near Its inferlion into the fub-cla- 
vian vein. . 

A thoracic dti6l is frequently found on the 
right fide, but much fmaller than that on the left, 
and formed by the union of the lymphatics, which 
come from the upper part of the right fide of the 

Circulation feems to be performed very flowly 
in the lymphatics ; and this fyftem, without doubt, 
is that which fhows the lead a6livity in its func- 
tions : the pafiage of the lymph through the glands 
contributes a great deal to check its progrefs. 

The ufe of the lymphatic fyfiem evidently is to 
bring again into circulation the ^efidue of all the 
fecretions, after making them undergo a particular 
afiimilation or fort of digeftion. 

This important funiSlion is performed flowly 
and without interruption ; and is maintained by 
the aftion of the nerves, which are diftributed to 
the lymphatics and their glands, and by the pre- 
fence of the fluids abforbed and brought into cir- 

' When the nervous action of this fyftem is dimi- 
nifhed, its fundion is checked ; and the ferous 
fluids, being no longer properly abforbed, remain 
in the large cavities or in all the tifllies, which 
gives rife to dropfies of different kinds and to 

Phyficians believed that they had found in the 



difcovery of the lymphatic veflels an explanation 
of a great number of the phcenomena of difeafe ; 
and they began to make a falfe application of thii 
knowledge, as is the cafe rwith almoft every new 

It was to the humorifl phyficians, in particular, 
that this difcovery feemed to be of the greateft 
utility. As they afcribed almotl all difeafes to hu- 
mours circulating in the fluids, they faw in the 
lymphatic fyftem a convenient way of conveying 
them to every part of the body, and of making 
them proceed with rapidity from one place to 

As the lymphatic fyftem abforbs the fluids ef- 
fufed in every point of the organization, they ima- 
gined that it ought to abforb alfo all thofe foreign 
fubftances fubje6ted to its a6lion ; and that it con- 
veyed them to different parts to produce in them 
accidents more or lefs fevere, or that it poured 
them into the blood to infe3 its whole mafs. 

But all thefe fuppolitions were mere conjedlures, 
fupported by no real proofs, and contrary to the 
progrefs of that function and to the common , 
phsenomena of life. 

It has never been proved, by any dire^ experi- 
ment, that foreign fubftances can be taken up by 
the lymphatic veflels and conveyed to diftant parts. 
The experiments made on purpofe to afcertein the 
-f * af bfT'-o} ^sd ^r-^d+tedt b^^^'.^hrf sokIc truth 


Htruth of this fad prove^ in an evident manner, thS 

Thus Dupuytren, in his ingenious experiments 
on the chyle> tried, but without fuccefs, to pro- 
duce an alteration in that fluid. He caufed dogs 
to fwallovv animal, vegetable, and mineral fub- 
ftances of every kind, which he thought likely td 
ieffedl changes in the quality of the chyle ; but he 
was never able to alter, in a ienfible manner, its 
tiature, its colour, or its odour. The gailric or- 
gans, by their vital energy, bppofe all thefe altera- 
tions: thiey digeft every thing fufceptible of di- 
geftion J ahforb what is proper for them, and rejedl 
what might prove hurtful to thiem. 

The cafe is the fame with the lymphatic fyfteni 
of all the parts of the body. The foreign fubftances 
introduced beneath the fkin, or conveyed into thia^ 
fubllance of the organs, are not abforbed, without 
being digeiied and reduced to principles fufcepti- 
ble of entering into circulation ; and fubftance^ 
taken up by the lymphatics, after this firft digeA 
tion, do not pafs into the venous blood until they 
have undergone a fecond aflimilation in the lym- 
phatic glands. 

But the nerves of the different parts cannot 
withdraw themfelves from the impreffion of thei 
foreign bodies which come in contact with them= 
This impreffion may change the mode of a(5iion 



bf the part, and produce a local pblegmaiiaj or 
he propagated as far as the cerebral centre, and 
give rife to general •demngements, more or lefs 
ferious, and which are afcribed to circulating hu- 

6i, We have already fhovvn that the arterial 
blood proceeds from the left fide of the heart to 
diflribute itfelf to every part of the body, and to 
carry thither the materials for the different fecre- 
tions; and that it returns by the veins, ta the 
right fide of that organ, from which it pafles tO/ 
its left fide by traverfing the lungs. 

The arterial blood maiiitains itfelf always at the 
fame temperature^ and at the fame degree of flu- 
idity, by means of perfpiration, and the fecretion 
0:f the urine; andlhus frees itfelf from the heat 
and water which it receives in excefs. 

The blood, which returns-by the veins, refumes 
the qualities of arterial bloody chiefly during its 
paflage through the liver and the iungs. 

We fhall here examine more minutely thefe 
important pbcenomena. 

6;j^. The heat bf the blood is maintained by the 
continual fecretions which take place in every part 
iof the organization. 

As the produ6is of the different fecretions have 
always more denfity than the materials which 

TOL. Ill, T f^rved 


ferved towards their formation, the refult muft ne- 
ceflarily be a continual difengagement of heat. 
This difengagement of heat is proportioned to the 
adivity of the fecretory functions : it is exceed- 
ingly weak when thefe funclions are performed in 
a flow, manner; and Itrong when they take place 
with great energy. A woman who iifes little ex- 
ercife, and only a very froall quantity of food, has 
always a cool dry fkin, and the greateft lofs of heat 
is fuftained by pulmonary perfpiration. On the 
other hand, a man employed in fevere labours, 
and who eats a great deal, has the Ikin humid and 
warm ; and an abundant perfpiration continually 
carries off a large quantity of his caloric. 

Thus animal heat is one of the pr6du6is of fe- 
cretion; its excefs read:s on the organs as a fiimu- 
lant ; and excites, in a particular manner, fecre- 
tion and fweat. The evaporation of this fluid, 
fecreted in excefs, carries off from the furface of 
the body a great quantity of caloric, and by thefe 
means the temperature is lowered. 

In proportion as the temperature of the body is 
lowered, neither fecretion nor fweat are fo power- 
fully excited, and the lofs of heat ceafes to be to 
great. It is by this organic regulator, that animal 
heat is always maintained nearly at the fame tem- 
perature of 40 degrees of the centigrade thermo- 
meter (104° Fahr.) 

In local phlegmaiise, when a thorn, for example, 



has been introduced beneath the fkin, the nervous 
adiion of the part is violently excited; circulation' 
is accelerated ; the fecretions take place v;ith more 
intenlity^ and the local heat is fenfibly increafed. 
But this augmentation of heat never extends be- 
yond two degrees, and if its intenfity appears to 
be greater, during the burning ardour which is 
experienced, this painful fenfation ought to be 
afcribed, in a great meafure, to the too ftrong 
nervous excitement, and to the derangement in 
the habitual order of the fundions of the injured 

Belides thelofs of caloric, difengaged by perfpi- 
ration, the body habitually lofes a great quantity 
of fluids by the ikin and the lungs. The fum of 
the fubftances which efcape by thefe two ways 
^exceeds the half of the weight of the whole ali- 
ments ; and pulmonary perfpiration is equal to 
that which takes place by the Ikin. 

The product of an abundant perfpiration is 
much more aqueous than that of the habitual per- 
fpiration, called infenfible : the latter is clammy 
and greafy, and affedls a peculiar odour, which 
varies in the different parts in the two fexes, and 
even in diflerent individuals. 

Heat and labour greatly increafe this excretion ; 
cold and reft can entirely fufpend it. 

The fecretion of fweat and that of urine feem 
mutually to fupply each other's places and the 

y 3, adtivity 


acclivity of their fundions is always in the inverfe 
ratio of each other. When fecretion of urine is. 
impeded, an analogous excretion takes place by 
the Ikin, and the fweat afTurxies a urinary cha- 

64'. The arterial blood throws out the quantity 
of aqueous parts, which it receives in excels, 
chiefly by the urinary pafTages. 

A raan, daring the whole day, may do nothing 
but drink and void urine ; and it is inconceivable 
what a large quantity of liquid may be thus made 
to pafs through the body in a given time. 

That a perfon may be able to drink a large 
quantity, without being injured, the water muil 
contain ftimulating fubllances, fuch as alcohol or 
acids ; thefe beverages then folicit the organs to 
diffeil them, and at the fame time excite the kid- 
neys to feparate from the blood a quantity of wa- 
ter, proportioned to that which has been drunk. 

If the beverage is nrierely aqueous^ and if taken 
in too great abundance, the gaftric and urinary 
lyftems are not properly Simulated ; the beverage 
is digefied only with extreme difficulty, or cannot 
be (o completely 1 and, in this cale, a vomiting- 
takes -place, or even indigeilion, which is often 
very dangerous. 

This important conxideration ought never to be 
loll fight of in difeafes, in which it is neceflary to 



avoid overchar^incf the weak and debilitated fto- 
mach with aqueous beverages. In this point of 
view the abufe of ptifans is much greater than is 

Fermented liquors are neceflliry to men who 
feed on coarfe aliments^ with Httle or no feafoning, 
becaufe it is always requifite that the ftomach 
fhould be properly ftimulated, either by -the drink 
or the food. But when the aliments are llrongly 
feafoned by the ftimulating produdions of warm 
countries, there is not much need for alcoholized 
liquors ; and people will fufFer much lefs inconve- 
nience by abftaining from them entirely, than by 
contrading the habit of ufing them to excefs. 

The need of fermented liquors is felt in a much 
fironger manner in warm and cold countries, 
where the organization is continually ftruggling 
againft the temperature, than in the moderate 

The arteries which proceed to the kidneys are 
very large ; it has been eflimated that their capa- 
city is fuch as to afford a paffage to the eighth 
part of the blood. 

The quantity of urine feparated in a given 
time, and' the fpeed with which it is fecreted in 
confequence of drink received into the ftomach, 
has induced fome to believe that there may exift a 
more direft mode of conveyance, than that by the 
blood, for tranfmitting liquors from, the gaftric 

y 3 organs 


organs to the bladder, and this funftion has been 
afcribed alfo to the lymphatic velTels; but this af- 
fertion is unfupported by proofs, and it is from not 
properly nnderftanding the limultaneous adlion of 
feveral organs, in confequence of the fame ftimu- 
lant, that it has been thought necelTary to recur 
to this hypothefis. ' 

The urine fometimes afTumes a colour analo- 
gous to that of certain fubftances received into 
the flomach; it has been fuppofed that this colour 
ariles from the prefence of thefe fubftances con- 
veyed^nto the blood, and tranfmitted thence to 
the urinary fyftem : thus the urine becomes fome- 
times red by the ufe of beet-root ; yellow by that 
of faffron or jalap, but without containing any of 
thefe fubftances ; for urine coloured yellow by the 
a6lion of faffron has not the leaft fmell of the fta- 
mina of that plant. 

If the urine fometimes aftiimes the colour of 
certain aliments or medicines, it often exhibits one 
very different : thus it becomes green by tama- 
rinds, blackithor puriform by oil of fweet almonds. 
Sec. If an aliment or medicine could communi- 
cate to urine a part of its fubftance, it woulcl 
doubtlefs be its odorous molecule j which, as ap- 
pears, ought to penetrate every where with great 
facility ; but this is never obferved to be the cafe, 
Thus afparagus, which has an agreeable odour, 
occaftons a very fetid fmell in the urine; and tur- 



pentine^ the odour of which Js, very. penetrating, 
gives to urine the fvveet ,and agreeable. odQUT of 

' In all thefe cafes, the changes which take place 
in the urine are the relult of a new mode of acr 
tion, con)fnunicatcrl to the renal fyftem. -There 
is no organ of fecretion, the product of which may 
not be changed, when a new mode of a6lion is 
thus excited in it; and it is well known how va- 
rious the fecretion of the mucous membranes is in 
catarrhal affedlions, and what a dreadful chara6ier 
the faliva afllimes in the hydrophobia. 

Hence the changes which take place in the 
urine, in confequence of certain fubflances being 
digefted, do not arite from thefe fubftances having 
palled into the urine in their naturaL flate, but 
from the fpecinc adlion which they particularly 
exercife 6n the kidneys, which changes their habir- 
tual mode of a6lion, and alters the ufual product of 
their fecretion, • 

It is chiefly in acute difeafes that the urine ex- 
hibits characters highly varied. Every time that 
the organization experiences a general derange- 
ment, the kidneys are afFefted in a manner pecu- 
liar to th'emfelves. Their mode of fecretion is 
changed ; and the urine aflTumes a particular cha- 
rafber, which may be indefinitely varied.^ vAkLjiA 
^ Urine vari^^ in particulary- iar^g^f^ilo -C[uan- 


tity, according as the a6lIon of the kidneys is in- 
creaied or diminished. 

The numerous changes of colour, confidence, 
and fmell, and the varied fediment which urine 
exhibits in difeafeSj have induced the vulgar to 
believe that the infpe6lion of it may be, of great 
utility in medical pra6iice ; and there have even 
been phyficians who confulted the urine of their 

Changes in the nature and quantity of the 
urine only announce that there has been a change 
of adlion in the kidneys. 

The urine generally ailumes the fame charac- 
ters in iirailar aftedlions; and the infpe6iion of it 
may then affill the prognofis. But unlcfs the 
phyfician be a good chemiil, and examine it by re- 
agents, it will be impoffible, in fuch cafes^ to de- 
rive from it mud^h benefit of importance. 

There is one particular affoShn of the kidneys, 
in which thefe organs rapidly fecrete an exceflive 
quantity of urine (diaheUsJ. All the nutritive juices 
are confumed in this way ; and the patient be- 
comes weakened as by a diarrhoea. This affe6lion 
does not arife from a relaxation of the kidneys, as 
is generally believed ; for an organ relaxed or de- 
bilitated does not perform its funfbions with more 
energy ; but it arifes from an increafed a'dlion^ a 
continued irritation in thefe organs^ 



Urine, by treeing the blood from a quantity of 
aqiieoiis part^. which it contains in excefs, takes 
from it aifo a great deal of other principles. The 
ilf>w of urinCj however, rnufl not be confidered as 
a Uxiviation, during which acid, faline, and earthy 
llibftances are carried off; but rather as a real le- 
c^etion, a peculiar organic operation, during which 
the greater part ofthe fubftances found, in urine 
are formed. Thus uric acid, the prefence of which 
forms the principal charafter of urine, is not found 
in the blood, but has been formed in the kidneys. 

In proportion as the urine is fecreted in the 
tifTue of the kidneys, it exudes from the mam- 
inellous tubercles rnto the calices, by which they 
are enveloped: it is thence colle6led into fmall 
bafons, from which it flows along the ureter, and 
is thus conveyed into the bladder. 

The urine colledted in the bladder gradually 
diftends it. When this organ has acquired a cer- 
tain degree of tenfion, it contrails ; and by the 
iimultaneous adion of its fides and of the mufcles 
of the abdomen and of the diaphragm, the refift- 
anceof its neck is overcome, and the urine is ck- 
pelled with more or lefs force. 

The bladder has been called the animal cham- 
ber-pot : it miift not be imagined that the urine 
remains there as in a veffel ; it is fubjeded to the 
continual aftipn of the fides which contain it; thefe 
iides make an effort to digefl: it, and incefTantly 



zMorh its aqueous parts, on which account the 
urine in the morning is much thicker and more 
charged than when voided a httle time after it has 
arrived in that organ. In regard to the unne of 
drink, of digeftion, and of the blood, it may be 
readily conceived how erroneous ail thefe diftinc- 
tions are : there is only one kind of urine, that of 
the kidneys, 

65. The arterial blood, in its circulation, dif- 
tributes itfelf to the organs of motion, to thofe of 
the fenfes and of fecretion, and carries thither the 
materials proper for the changes continually efFed,- 
ed in all thefe parts. But it diftributes hfelf alfo 
to fome organs, with the ufe of which we are not 
yet acquainted : of this kind are the thyroid gland, 
the thymus, and the fpleen. 

The thyroid gland, larger and of a darker co- 
lour in children than in adults, in the female 
than in the male, is fituated in the middle part of 
the neck, before the bottom of the larynx. It 
feems to be compofed of an afleinblage of lobes, 
divided into lobules : in the interior part it exhi- 
bits fmall veficles, which contain a yellow vifcous 
fiuid. It is a fwelling of this gland that produces 
the goitre. This afFedion, peculiar to women of 
certain countries^ is the refult of caufes hitherto 

The thymus is a glandalous body^ fituated be- 


bind the fternum, between the two laminae of 
the pleura. It is of a large fize, flabby, arid of 
a pale yellow colour in the fcetus ; it decreafes, 
affiimes more conflftence, and acquires a darker 
colour with age ; and in old age difappears entirely. 

In the foetus, the thymus, compofed of two 
lobes divided into lobules, exhibits in the infide 
an albuminous, whitifh fluid, and has no apparent 
excretory dudls. 

The fpleen, fituated in the left hypochondrium, 
is of a foft confiftence, x^ellular, and has a blueifli 
red colour : it receives a very large artery of the 
coeliac trunk. 

The arterial blood, after diftributing itfelf to 
every part of that organ, returns by veins which^ 
by their union, forms a trunk that proceeds into 
the liver. Hence it appears that* the ufe of the 
fpleen is to give its blood to the liver, after it has 
undergone a change, which renders it analogous 
to the venal blood. 

66, The blood, after being diftributed to every 
point of the organization, and having thus dif- 
charged the fundlions peculiar to it, returns from 
all thefe points, in the ftate of venous blood and 
lymph, to repair its lofl!es ; to refume again the 
qualities of arterial blood, and to be fitted to ferve 
for a new dillribution. 

The lofles which th^ venous blood has fuflained, 


$S% Vital functions. 

daring its diftributionj are repaired by the pro- 
duct of digeftion. 

The chyle and the lymph, before they mix 
wfth the venous blood, begin to experience 
changes in their paiTage through the lymphatic 
glands ; thefe fluids undergo a peculiar affimila- 
tion, and again acquire charadlers of animaliza- 
tion, which render them proper to form confti- 
tuent parts of the organic fubftances. 

The venous blood fcems to return to the fcaie 
of arterial blood, by freeing itfelf from fome fub- 
flaoces and by taking up others. 

In its pafTage into the liver and the lungs it 
abandons thofe materials, by which it is conftituted 
venous blood, and abforbs new principles in the 
refpiratory organ. 

A part of the' venous blood, before it returns to 
the right tide of the heart, patles through the 
Jiver. Thus the veins, which bring back the blood 
froni the ftomach, the inteftines, the epiploon, 
the mefentery, the pancreas, and the fpleen, 
unite into two trunks f^he fplenic and mefera'ic), 
which are foon confounded into one vein (thefiih- 
hepatic or vena-port^). This arterial vein, which 
is very largej penetrates into the liver tovt'ards the 
Biiddle of its tranfverfe fcifTure ; the blood, which 
it .carries thither, is diftributed to every part of 
that voluminous organ, and difappears in the very 
fine divifions of the capillary ramufculi. 

- The 


The venous blood, which travedes the vifcera 
and the. abdomen, and particularly the mefentery 
and the epiploon, is overcharged with> a great 
deal of fat parts, from which it feems to be freed 
chiefly in the fecretion of the liver. The liver by 
its a^iion fecretes the bile, wliich is evacuated by 
a peculiar order of velTels ; and which procee^ls 
into the duodenum, where it becomes one of th® 
moil powerful agents of digefticn. 

In the fecretion of the bile, the blood is rie- 
cefTarily freed from the hydrogen and carbon of 
which that uncliious humour is corapofed; and 
by thefe means is difpofed for refiwning the quali- 
ties of arterial blood. 

It is of fo much importance to the organic order 
that the blood {hould free itfelf from the princi- 
ples which form the bile, that when the fecretion 
of this fluid cannot take place in the liver, in con- 
fequence of fome peculiar affcclion of this organ, 
it appears that it is produced in other diftant parts. 
Thus in the jaundice an analogous fecretion of 
bile takes place in the kidneys, in the cellular 
tifliie, and in the flcin. 

It is not, therefore, for the parpofe of digef- 
tion alone that the bile is produced ; becaufe 
when it cannot be feparated in the liver it is fe- 
cretcd fomewhere elfe. In this cafe, the efl^ntial 
phasnomenon always takes place j the blood aban- 

534 VlfAC FtTNCTlOMS; 

dons the materials of the bile from which it waS 
neceflary it fhould be freed, and it is the acceflbry 
phaenomenon, the peculiar ufe of the bile in di- 
geftion, which is for a. moment impeded. 

We have here another infi:ance of the facility 
with which the organs can mutually fupply the 
place of each other in their fund^ions. 

The humorifts, according to their hypothefiSj 
did not fail to afcribe the jaundice to bile conveyed 
into the blood ; but the folly of this aflertion may 
be eafily conceived. 

If We fuppofe, that the bile fecreted by the 
liver is abforbed by the lymphatic veffels of that 
organ, in order to proceed into the blood, it muft 
firfl pafs into the thoracic du6t, then into the fub- 
clavian vein, then into the right fide of the heart, 
then into the lungs, then into the left fide of the 
heart, and thencfe into the aorta to be uniformly 
diftributed by the arteries. 

It is much more reafonable to think that the 
venous blood, not being able in the liver to aban- 
don the materials of the bile, from which it ought 
to be freed before it pailes into the lungs, depofits 
them in the cellular tiffiie of the different organs, 
where they are afterwards digefted ; and that their 
elements are taken up by the lymphatics, or ex- 
pelled by perfpiration. 

In acute difeafes-^ where there is a general de* 




rangement, the adion of the liver, like that of the 
other organs, is interrupted. In this cafe, if the 
aiFedlion of the liver be of fuch a nature that its 
fundion is weakened or impeded, and if the fe- 
cretion of the bile cannot take place in that organ, 
it will be feparated elfewhere, and there will be 
fymptotns of jaundice, which are not defervingof 
particular attention. 

It refults from thefe conliderations, that the 
blood undergoes in the liver changes analogous 
to tbofe which it experiences in the lungs ; and 
that under this point of view the liver and the 
lungs are two organs which have analogous fane- 
lions, as Fourcroy announced feveral years ago. 

It evidently appears that the liver difcharges the 
fundtion of the lungs, in circumftances when re- 
fpiration has very little a<5livityi hence it is pro- 
portionally very large in the foetus, which does 
not yet fefpire ; it is in general very voluminous 
in reptiles and fiOies, in which refpiration is ex- 
ceedingly flow ; and it is exceedingly fmall in 
birds, which have the pulmonary organ very large 
and energetic. 

In fome cafes of difeafe, fuch as phthifis, the 
liver fometimes becomes exceedingly voluminous 
and fat ; but it is very doubtful whether its a6tioti 
be then increafed : it is much more probable, that 
the fwelling of this organ is a ftate of difeafe, 



during which the fecretion of the. bile is pei* 
formed only with difficulty. 

6j> When the venous blood has undergone a 
fird affimilation in its pallage through the liver^^ 
as the Ijuiph and the chyle do in traverfing the 
lymphatic glands, it returns from all the parta 
hy means of the veins, which unite into two largd 
1:runks : one of them brings back the blood from 
the lower parts (the abdominal venacuva), and 
the other from the upper parts (the thoracic vena- 
cava). Thefe two veins proceed to the right 
fide of the heart with the fmall cororiary vein i 
the blood penetrates into the right auricle and 
dilates it j when this auride has acquired a cer- 
tain degree of dilatation it contra6^s, and the 
blood pafles into the ventricle, except that part 
which flows back. The blood accumulated in 
the right ventricle diiiends it alfo j the fides of 
this cavity contradl., and force the blood into the 
pulmonary artery, from which it is expelled, to- 
wards the lungs. 

The blood cannot flow back from the ventricle 
to the auricle on accouat of a valve (vajvuld 
tr'icufpis)\ which oppofes it ,• and it cannot return 
from the pulmonary artery to the ventricle, be- 
caufe it is prevented by the fygmoid valves. 

It is to be remarkcdj in the motion of the hearty 


that the right auricle contrafts at the fame time 
as the left, and that the contraction of the two 
ventricles is effefted at the fame moment ; fo that 
the motion of the auricles and ventricles takes 
place fucceffively. 

68. The blood which pafles into the lungs is 
blackifh, lefs warm (by two degrees), and a little 
heavier than arterial blood : it exhibits, therefore, 
the charadlers of venous blood. 

The venous artery, Nvhich diftributes this blood 
in the pulmonary organ, foon divides into two 
trunks, one for each lung. Thefe arteries then 
feparate into branches and rami : thefe rami into 
ramufculi much fmailer, and the ramufculi fub- 
divide into capillary velTcIs which elude the fight. 
The venous blood is thus difperfed throughout 
every part of the lung ; being reduced to a ftate 
of extreme tenuity, it undergoes there, during the 
a<5l of refpiration, certain changes, which make it 
refume all the qualities of arterial blood ; it be- 
comes red, florid, fpumous, warmer, and lighter. 
It then returns to the left tide of the heart by 
veins, which arife from every part of the lungs ; 
which unite into rami and branches, and at lafl: 
terminate in four large trunks, which proceed 
into the left auricle. 

The blood pafles thence into the ventricle of 
the fame tide, and into the aorta, from which it 

VOL. in. 2 is 


is expelled by the arteries, to be again diftributed 
to every part of the body. 

69. The changes which the blood undergoes, 
in paffing from the venous to the arterial ftate, 
take place in the interval between the moment 
when that fluid eludes our refearchcs by the arte- 
ries, and that when we begin to fee it return by 
the veins. It is in this infinitely fmall fpace, 
which our eyes, aflifted by the beft inftruments, 
cannot penetrate, that the phssnomena of refpi- 
ration are efFedled. 

It is proper here to remind the reader, that the 
lung, in its intimate ftru6lure, exhibits ramifica- 
tions of the bronchic cavities. The air, which pe- 
netrates into this organ, enters by the mouth or the 
iiofi:rils, pafles through the aperture of the glot- 
tis, Iraverfes the larynx and the trachea, and en- 
ters into all the divifions of the bronchise. 

The bronchiss mufi: be confidered as aerian 
vefiels, which divide, in the interior of the pal- 
monary organ, into branches and rami; which 
are fubdivided .into capillary raraufcuH of extreme 
finenefs, and at length terminate in fmall cells, 
which communicate with each other. All thefe 
aerian pafTages are lined by a mucous membrane. 

The arteries accompany the bronchic divifions, 
fubdivide in the fame manner, and expand on 
the fides of their cells ; the veins arife from thefe 

, . fides. 


fides, and in their paflage follow alfo, in an in- 
verfe order, the divifions of the aerian paflages. 

The air enters into the cavities of the bronchiae, 
and ifluies from them alternately daring the move- 
mentS' of infpirat-ion and expiration. Infpiration 
takes place by the dilatation of the fides of the 
breaft and the depreffion of the diaphragm. 
The dilatation is efFe6ted by the a6lion of the 
interCoftal mtifcles, which carry forwards and to- 
wards the ribsj the fides of the breaft, and par- 
ticularly towards the bottom of them. During 
flrong infpirationSj this movement is affifi:ed by 
the ax^ion of the mufcles attached to the fides of 
the thorax, which extend to the bones of the 
neckj of the flioulder, and of the arm. 

The diaphragm, which in its natural fi:aie is 
convex towards the breaft, finks down, becomes 
horizontal by the conlra6tion of its mulcular fibres^ 
and increafes the capacity of the thorax. 

' Expiration takes [)lace by the mere relaxation 
of the mufcles which contributed to dilate the 
breaft ; when the adlion of theie mufcles ceafes, 
the parts refume their former ftate. Complete 
expiration is favoured by the contra6iion of the 
abdominal mufcles, and particularly thofe which 
are attached to the bottom of the thorax. Thefe 
rnufcies, in contrafting, lower the breaft, and 
comprefs the inteftines, which deprefs again the 
diaphraj^n, in the interior part of the thorax. 

2 2 During 


During the dilatation of the cavity of the tho- 
rax, the lungs flre diftended 5 a fort of vacuity is 
formed in the bronchic cavities, and the external 
air immediately rufhes into them. This air then 
jifues by the depreffion of the fides of the thorax, 
and the relaxation of the diaphragm. 

Refpiration, when once begun, never ceafes but 
with life ; it is maintained by the a6lion of the 
nerves, which diftriiDute themtelves to every part of 
the organ of refpiration, and by the continual 
neceffity which the blood has of experiencing 
the changes it undergoes by the fund:ion of the 

The movements df the breaft are fuch, that 
about eighteen infpirations take place in a mi- 

From this iliort view of the movements of the 
bread and of the llrudure of the aerian cavities 
of the lungs, it may be readily conceived that the 
air, vvhich penetrates into the bronchia^, follows 
their ultimate divifions ; and that when it reaches 
the laft bronchic cells it muft be almoft in imme- 
diate contact with the blood. 

It is now proper toi examine the changes which 
the infpired air and the blood experience, in order 
that we may thence deduce the nature of the 
phagnomena which muft have taken place. 

The atmofpheric air infpired is compofed of 
about four-fifths of azote, and one fifth of oxygen. 



The expired air contains almoft the Tame quan- 
tity of azote, but it now retains no more than 
about the half of its oxygen, with a quantity of 
carbonic acid gas, lefs than that of the oxygen, 
which is wanting. 

This important obfervation, for which we are 
indebted to the pneumatic chemillry, has given 
rite to various hypothefes. 

The authors of the modern cheraiftry are of 
opinion, that the carbonic acid gas produced is 
formed in the lungs, by the combination of the 
carbon, difengaged from the blood, with the oxy- 
gen of the atmofphere ; but I afTured myfelf of 
the fallacy of this opinion by the following ex- 
periment. I placed fome Guinea pigs under a 
bell glafs, filled alternately with atmofpheric air, 
oxygen gas, azotic gas, and hydrogen gas ; and 
in all thefe cafes there was nearly the fame quan- 
tity of carbonic acid gas difengaged : its forma- 
tion then is not owing to the prefence of oxygen 
in the lungs. 

Ghemifts have imagined alfo that a part of the 
oxygen infpired is combined, in the lungs, with 
the hydrogen difengaged from the blood ; and 
that the v^ater emitted, during expiration, in the 
flate of vapour, is the refult of their combina- 
tion i but it is much more reafonable to fuppofe 
that this vapour expired, is fecreted by the mu- 

a 3 * cous 


cous furfaces cf the bronchic cells, like all the 
liquids which moiften the other organic furfaces. 

The fuppofed formation of carbonic acid ga§ 
and water, by mecnns of the oxygen of the air, the 
carbon, and the hydrogen of the blood, ought 
neceflarily to be accompanied with a difengage- 
ment of caloric; and it is to this driengagement 
that animal heat and the habitual elevation of the 
temperature were afcribed ; but the premifes be- 
ing erroneous, the confequence deduced from them 
muft be erroneous alfo. 

Chauffier has iincc propofed an opinion, which 
appears to be more probable. The carbonic acid 
gas, he fays, is completely formed in the venous 
blood; it is only difengaged by expiration, and 
the oxygen gas is abforbed by the lymphatic 

This afiertion, much more agreeable to the 
common phsenomena of the organization, appears 
to me, however, in one of its points, to require 
fome modification. Experiments made with great 
care (hew, that this gas does not exifl: in 
-the blood. Befides, it is a general obfervation, 
that the blood contains no products of fecretion 
completely formed ; it only pofleiies the princi- 
ples of them which it aiiimilates in the organs of 

Thus it is probable, that in the ad of refpira- 



tibn, the blood frees itfelf from the conftituent 
principles of the carbonic acid gas, in ihc/ecre^ 
tion of that gas : as it frees itfelf from the confti- 
tuent principles of the bile, in the fecretion of 
that fluid. On the other hand, the lungs are a 
real Organ of digeftion : they aflimilate oxygen 
gas, and probably a fmall quantity of azotic gas-; 
thefe materials enter into the circulation, and 
ferve for general nutrition and for the produ^ioo 
of heat. , ; :^ ;-: t 

The caloric, which maintains the habitual tecn-» 
perament, and which is continually difengaged, 
feemsfo pafs into the organization .by the pulmo- 
nary organ, where it is abforbed V^ith a portion of 
atmofpheric air. 

In the different claiTes of animals with lungs, 
it is indeed obferved, that the animal heat follows 
the ratio of the extent and adivity of the organ 
of refpiration . Hence it is at the higheft degree 
in birds ; lefs in the mammalia, and very incon- 
liderable in reptiles. 

The blood which proceeds to the lungs has 
a blackifh colour ; and it returns from that organ 
with a beautiful red tint. Chemifts afcribe the 
beautiful red colour of the arterial blood to the 
abforption of oxygen ; becaufe the venous blood 
becomes red when in contact with that gas ; but 
it aflbmes the fame colour by warmth, and ani- 

z 4 mals 


mals reduced to a ftate of afphyxia, by carbonic 
acid gas and the gafeous oxide of carbon, have 
very red blood alfo. 

It is probable that the venous blood lofes its 
blackifh colour in the lungs, by freeing itfelf from 
thofe principles which form carbonic acid gas. 
But, however this may be, a difference of colour 
is, in general, a matter of very little importance. 
It- is well known, that different arrangements of 
the fame moleculse of a body are fufficient to pro- 
duce changes, exceedingly various, in the reflec- 
tion of the luminous rays, and confequently in 
its coloration. We know that the arterial blood 
is reddey, more fpumous, and warmer than the 
venous blood ; but chemical analyfis fhews no 
efiential difference between thefe two kinds of 
bloodj in regard to their compofition. 

70. When refpiration has been fuddenly fuf- 
.pended, death takes place in a few minutes. It 
was natural, therefore, that attempts fhould be 
made to account for this extraordinary phaeno- 

Chemifts have fuppofed, that as the abforption 
•of oxygen by the blood is the principal pheno- 
menon of refpiration, death enfues when this ab- 
forption cannot take place ; becaufe the bloody 
being .deprived of its habitual ftimulantj can no 
■Z-i ■'■ longer 


longer excite, in a proper manner, the lef*" ven- 
tricle of the heart, which then ceafes to contract. 

But, in the different kinds of afphyxia, it is 
obferved, in general, that the aortic ventricle is 
always empty, while the pulmonary ventricle Is 
full ; which evidently proves, that the left lide of 
the heart did not ceafe to contrail till it ceafed 
to receive blood, ■' 

On the other hand, Guinea pigs expofed to 
azotic gas, and very pure hydrogen gas, live a 
confiderable time, and their death feems to be 
occalioned, in part, by the prefence of the car- 
bonic acid gas expectorated ; fo that the want of 
oxygen, in refpiratibn, does not become fatal fo 
fpeedily as has been fuppofed. 

Afphyxiae may be diftinguifhed into three forts: 
ifl. Thole which take place in confequence of the 
entrance of air into the lungs being fuddenly in- 
tercepted : zd. Thofe which take plac^ when the 
lungs, inflead of receiving atmofpheric air, receive 
a foreign gas, which however exercifes no perni- 
cious adlion : 3d. Thofe which refult from the 
introduction into the air-paflages of any fu|?- 
flance which exercifes a fpeedy and fatal adlion. 

Afphyxiee, which take place in confequence of 
the air being prevented from entering the lungs, 
are thofe which refult from the different modes of 
itrangulation, fuffocation, and fubmerfion. It is 



probable that in all thefe cafes death enfues, be- 
caufe the play of the lungs is neceflary to pro- 
mote the circulation of the bloody the whole of 
which paffes through that organ : refpiration be- 
ing fuddenly fufpended, circulation may be pre- 
vented ; and death, which at firft is only appa- 
rent, >foon becomes real, if fpeedy relief be not 
applied. Death, in all probability, takes place fo 
foon, merely becaufe the organization has not 
time to accommodate itfelf to fo great and fo ab- 
rupt a derangement. It is well known that divers 
gradually habituate themfcK^es to remain under 
water for a longer time than is fufficient to drown 
,ibme perfons completely. 

When an animal is immeifed in very pure azo- 
tic or hydrogen gas, the play of refpiration is not 
fofpended ; infpiration and expiration continue to 
take place J circulation is not interrupted, and life 
continues. The lungs, however, are deprived of 
their habitual aliment ; and when this privation is 
fuddcn, and continues too long, the animal at 
length perifhes. But, if it be flowly habituated to 
refpire in one of thefe gafes, and if care be taken 
to ablorb the carbonic acid gas expectorated, the 
reaction of which on the lungs is fo fatal, it may 
readily be conceived that the privation of oxygen 
gas may be endured for a very confiderable time. 
Azotic and hydrogen gas, therefore^ do not kill, 



but fufFer the animal to die flowly, becaufe they 
merely maintain the play of refpiration, without 
fupplying the aliment necefTary for life. 

The afphyxiaj 'vhich take place in confequence 
of deleterious fabftances conveyed into the lungs 
are the mod numerous. They are thofe occa* 
lioned by the infpiration of the carbonic acid gas, 
difeneraffed from wine or beer calks in a ftate offer- 
mentation^ from lime-kilns, &c.; by the infpiration 
of the carbonated hydrogen gas produced by char- 
coal, when it begins to burn with a flightly blue- 
ifh flame, and by the infpiration of the vapours* 
exhaled under certain circumflances from privies^ 
drains, burying grounds, &c. Thefe fubftances, 
conveyed into the lungs with the infpired air, 
produce, fometimes, on the nerves of that part, an 
impreffion fufficiently violent to occafion a ge- 
neral derangement of the nervous adiion and fud- 
den death. Thefe afphyxiae exhibit a phseno- 
menon analogous to poifoning, by thofe fubftances 
called narcotics. 

When the deleterious fubftances conveyed into 
the. lungs are not fufficiently ftrong to produce 
afphyxia, they may give rife to a highly varied 
feries of morbific phaenomena. Thus the greater 
part of epidemic fevers feem to be produced by 
emanations from vegetable or animal fubftances, in 
a ftate of putrefa6lion, conveyed iqto the lungs, 



and efpecially of individuals who have a difpoii- 
tion fuited to them. In the plague^ thefe Tub- 
fiances introduced in a larger quantity into thefe 
organs of a weak individual, already altered by 
fear and defpair, may produce fudden death ; as 
has been obferved in all cafes where the plague 
has been epidemical. Deaths on fuch occafions, 
is a real afphyxia. 

^i. The venous blood, after pafling through 
the lung,^^ and having refumed there the qualities 
of arterial blood, proceeds into the left fide of the 
heart by four large veins, which depofits it in the 
auricle, whence it pailes into the ventricle, and 
thence into the aorta, to be again diftributed to 
all the organs by means of the arteries. 

The atmofpheric air infpircd, after remaining 
in the lungs, and lofing there a part of its oxy- 
gen, and perhaps a fmall quantity of azote, is in 
part expelled at each expiration along with the 
carbonic acid gas which has been excreted. 

But air vv^hich enters and continually iiTues 
through a narrow aperture, furnifhed with a 
moveable appendage, and which may be driven 
with greater or lefs force into a cavity where the 
found produced is modified before it ifTues from 
it, furnifhes all the conditions neccflary for a wind 
inftrument. Thus the air, after conveying into 



the lungs one of the principal aliments of life 
and the Iburce of heat, may in its return receive 
a vibratory movement, which is trarafmitied to a 
diftance; and, in the formation of the voice, con- 
liitutes an artificial lign exceedingly proper for 
the improvement of the mind, and the means 
which have the greateft tendency to unite men in 
the bonds of fociety. 

The vocal organ is an apparatus, the fund:ion 
of which is difficult to be underftood ; and the 
phyfiologift who hears the harmonious founds 
which proceed from fome throats, is much more 
aftonifhed by the difficulty overcome, than by 
the efFed: produced ; for it is perhaps hardly pof- 
fible to conceive an inflrument more refradory 
than the vocal organ of man. But this proves 
how far the parts of the body, by their furprifing 
flexibility, can overcome the greatefl difficulties, 
and furmount every obftacle. 

The fimplefi and moft perfect vocal organ is, 
no doubt, that of birds. Thefe animals, at the 
union of the bronchlse, on the fides of the lower 
part of their trachea, have two membranous folds, 
which in part clofe the aperture of the latter. 
The air expelled from the lungs makes thefe 
membranes vibrate ; their vibrations are commu- 
nicated to the air, and a found is thus produced. 
This' inferior hrj?w is, for the moit part, fur- 



niflied with fmall mufcles, fufceptible of caufing 
a variation in its movements. The trachea, v/hich 
confifts of very fine cartilaginous rings united by a 
membrane, is capable of being lengthened or 

' In the laft place, the fuperior larynx has an 
aperture fufceptible of contracting or dilating, fo 
that the vocal organ of thefe animals is a wind in- 
ilrument, entirely analogous to thofe of the order 
of horns ; its mouth is towards the lungs *. 

If the theory of ftringed inflruments be applied 
to this wind inftrument, according to the method 
of Euler, it maybe fubjeded to calculation ; and 
the length of the ftring, its degree of tenlion, and 
its vibrating force, may be appreciated. 

The length of the ftring is meafured by that of 
the trachea ; its degree of tenfion by the aper- 
ture of the fuperior larynx ; and the vibrating force 
by the expulfion of air from the lungs. 

In man, the vocal organ exhibits another ar- 
rangement ; there is no larynx at the bottom of 
the trachea ; the air expelled from the lungs by 
the bronchise traverfes the trachea, as in a 
conducting tube, and at its paflage through the 
larynx meets with the epiglottis. This naoveable 
cartilage, when ftruck with force, vibrates, and 

"* Sec the Memoir of C. Cuvier. 



makes the furrounding air enter into a ftate of 
vibration alfo. The found, therefore, is only 
produced on its ilTuing from the larynx, and is 
afterwards modified in its paiTage through the 
mouth and noftrils. 

To judge of the value of the vocal organ in its 
natural fiate, and of the quality of its tone, no- 
thing is neceflary but to hear the cries of an in- 
fant ; and when we reflect that means have been 
devifed to produce from this inftrument the mod 
harmonious founds, it is hardly poffible to con- 
ceive how fo great a difficulty could be ovo*- 

The founds produced at the aperture of the 
larynx, when accented by the different parts of 
the moutji, form j^^^^:^', and modulated founds 
con^hutQ Jlnging. 

The vocal organ of man, though attended with 
lefs advantage than that of birds, exhibits an ana- 
logous ftruclure, and may be referred alfo to the 
theory of flringed iniiruments. 

The lenglh of the cord is meafured by the dif- 
tance comprehended between the aperture of the 
glottis and that of the mouth or noftrils ; this 
length may be varied by the elevation or depref- 
lion of the larynx, and even by the pofition of 
the lips. 

The vibrating force depends on that of the 



lungs, by which the air is expelled; and the 
degree of tenlion on the variable aperture of the 

Though the voeal organ of man be a wind in- 
Urument, not very advantageous, it affords a great 
many refource^ in regard to its innprovement ; 
thus the found produced, on the air iffuing from 
the larynx, may pafs from grave to acute, accord- 
ing as the aperture of the glottis is greater or 
fmaller ; as the larynx is deprefled or elevated, 
and the neck more oi* lefs elongated 5 and accord- 
ing as the mouth is more or lefs open. Sounds 
when once formed, may be modified a great 
many ways, by the varied movements of the 
tongue, the cheeks, the teeth, the lips, &c., and 
by its paffage through the noftrils. Sounds, ac- 
cording as they have been modified by any of 
thefe organs, are diftinguiflied by the names of 
labial, dento-lingual, palato-lingual, &c. articu- 
lations, &c. {^ee. Lexicograplne de'Butet.) 

Man has employed the found which may be 
produced by air expired with velocity as a con- 
ventional lign, merely becaufe pain obliged him 
to emit cries, which induced him to think that 
he might render thefe cries of utility ; for if the 
air, in iffuing from the lungs, had not been ac- 
companied with found, he would have remained 
as dumb as a perfon born deaf. 



When children hurry too much in the accentu- 
ation of founds, they repeat the fame lyllables 
foveral times, which is called ftammering. This 
defe6^, when not of too long {landing, may be 
corredled, by making the child acquire a habit of 
pronguncing each lyllable difl:in<5tly, one after 
the oth^r. 

VOL. in. % h . AGTION 

V 334 . J- 

JlCtion of the organs of re:. 

72. xLvERY organized being is prodoced by aw- 
other fimilar to itj and from which it is feparated, 
after having formed a part of it. 

Organized beings, whofe mode of reproduction 
is known, exhibit two ways by which they may 
completely attain to this fmiClion. 

When a part of an organized being is fufcep- 
tible of being detached from it to form a limilar 
being, this mode of reprodudion is called that by 
flips ; thus the germs of fojne plants detach them- 
felves from the Rem, and being received in the 
earthj, produce other plants, as is the' cafe with 
the ornithogalus. Some bulbous plants produce 
fmall bulbs, which increafe, fend forth roots, and 
detach Ihemfelves from the parent bulb to form 
new ones. Polypes fend cut gems from every 
part of their bodies, whicb increaTe in fizG, detach 
themfelves, and form entire polypes. The lafi: ar- 
ticulation of the naides increafes and detaches it^ 
felf to form a perfeCl animal. 

For the fame reafon, v.'e ought to be able to 
divide an organized being into feveral parts .fuf- 
- ceptible- 


ceptlble of reproclucriig itfelf^ provided each of 
them contains a bud or germ. Thus a twig de*- 
tached from the root of a tree may produce an- 
other tree, provided this twig contaifTS a bud. A 
polype may be ciit into a great number of parts, 
^hich produce entire polypes. 

But what appears to be very extraordinary is, 
that a worm which has a head, a trunk, and a 
iail, atll very diftind, fhould be fufceptible of di- 
vifion into feveral pieces, capable of reproducing 
the parts whith are wariting to them ; though in 
this animal the head contains a cerebral f}ftem, 
and though the apparatus of generation is in- 

^3. The feeds and the ova, like the buds and 
germs, are fmall bodies'vvhich detach themfelves, 
and by their development produce beings fimilar 
to thofe from which they proceeded ; but they 
differ from them in this refpe6l, that they have 
jieed of being ^Yev\ai\{[yfecu?idated. Living beings, 
which multiply by flips, reproduce themfelves alio 
from feeds and from ova. 

The individual which bears the feed or the esfo: 
may alfo bear the fecundating organ ; or thefe two 
organs may be in feparate individuals. 

The union, in the fame individual, of the feed 

or the ovum, and the organ proper for fecundating 

kj, conftitutes hermaphrodifm. The feparation 

2 A 2 of 


of them in two diftind: individuals efiablifhes 
difference of fex. 

The greater number of vegetables are herma- 
phrodites. Thre male parts may be united in the 
fame flower with the female parts, or both thefe 
parts tnay be found in feparate flowers. 
'Moll fhell animals arc hermaphrodites; the 
eggs are fecundated by the male organ, in de- 
fcending along the oviduA. Some of thefe ani- 
mals, though provided with male and female or- 
gans, have ftill need of copulation ; of this kind 
are the fnail and the Aug. It does not, however, 
appear that in the copulation of thefe animals the 
male organ of the one can ferve to fecundate th6 
egg of the other ; there is more reafon to think 
that their copulation is a Simulant proper for fa- 
vouring their individual fecundation. 

74. The feeds and the eggs are compbfed of 
the germ, and the nutritive apparatus which is 
deflined to promote its firft development. 

In plants and the greater number of animals, 
the nutritive apparatus, which envelops the germ, 
is fupplied, at the expenfe of the mother, with a 
quantity of nutritive fubftance fufficient for its firft 
increafe, and for enabling it to break the (hell, ii;! 
order to live by its own flrength. 

In the mammalia, the nutritive apparatus is 
fixed to the fides of the matrix, and draws from 



it juiees which it aflimilates and diftributes to the 
embryo. ; •. j^r^r-y. , 

The ovarium muft have acquired its oolnplete 
development, before the feeda or the eggs, which 
it contains, can be fulceptible of fecundation.^ . 

The feeds or the eggs may detach themfelves 
from the ovarium before or after their fecui^aT 

lion* rt f^fljK;!'?*;. ■.^!; , 

The eggs detached from the ovarium, before 
fecundation, may be afterwards fecundated, or 
may not be fufceptible of it. 

Some feeds ripen without having been fecun- 
dated ; but they remain barren. 

The eggs of birds often come to maturity with.- 
out having been fecundated, and in that cafe are 
no longer fufceptible of it *. 

In all thefe cafes, the nutritive apparatus afTumes 
a proper increafe at the expenfe of the mother, in 
order to ferve for the nutrition of the germ, whe- 
ther the latter is to be developed or not. 

The ova feparated and ejecSted from the ova- 
rium of certain ofTeous fifhes may be fecundated ; 
and thofe of feveral reptiles> fuch as frogs, are. 

* It Is probable that when thefc feeds or eggs have acquired 
their full increafe before fecundationi 'the thick ftrdng covering 
which furrourtdi the gertti is aft obftacli to their future foiun- 

a A 3 The 


The liquor of the male organ fufpends this putre- 
fadion, even when in an advanced ftate, and car? 
air© produce fecundation. 

76. Though the prefence of the organ of gene- 
ration in the male and in the female is not necef- 
fary to the life of the individuals, and though 
thefe organs appear, as we may fay, to have been 
fuperadded, they exercife a v6ry ftriking influ- 
ence on the whole of the organization, as is ob- 
ferved by the difference which exifts between in-, 
dividuals provided with thefe organs and thofe 
which are deprived of them. 

In organized beings, which exhibit two different 
fexes, the a6l of fecundation is performed by 
a complex apparatus of organs ; life is exalted, 
acquires more energy, and feems to be prepared 
as for an important aft. All the powers are di- 
rected to and concentrated in the generating -or- 
gans ; and after fecundarion the individuals expe- 
rience a manifeft ftate of lano-uor. The male 


feems to have made the greateft effort, and (hews 
a more remarkable depreffion ; but at that pe- 
riod his iaik is finifned, and a new one begins 
for the female. 

Some plants, fuch as pinks and the lychnis, 
when forced to llerility, live longer and refifl the 
cold better. 



Butterflies exift under the winged form, only 
ki., order to reproduce themfelveSj and after fatis- 
fy'mg this law they foon die. 

In order that fome animals may fatten, they 
are deprived of the eflential organs of genera- 

76. The male, of almoft all animals which 
copulate, places himfelf on the back of the female 
during coition ; in fome, however, there are cer- 
tain difpoiitions, fuch as a broad thick tail, which 
prevent this mode of copulation : the female of 
the hedge-hog and porcupine places herfelf on her 
back. This mode of copulation is that of ceta- 
ceous animals, the rays, fquali, and the crocodile. 
The female elephant only bends her fare legs ; 
the oftrieh lies down on its belly ; ferpents entwiffc 
themfelves with each other, &;c. Some reptiles, 
fuch as toads, adhere fo flrongly to the female, 
that they will rather fufTer themfelves to be torn 
than to feparale from them. 

Infe^ls almoft always exhibit in their fore claws 
the means proper for keeping themfelves Hxed on 
the female; and the femnles^alfo have frequently 
hooks by which they lay hold of the male daring 
their long copulation. The duration of this acl 
varies in the different clafles: in birds it fcarcely 
continues a few feconds ; it is longer among the 
mammalia, and particularly thofe which have no- 
2 A 4 feminal 


feminal veflel, as is the cafe with the dog j in 
the laft place, it is exceffively long among fome 
reptiles, fuch as frogs, which continue in a Hate of 
copulation even forty days. 

'^ All organiaed beings continually reproduce 
themfelves in this manner, amidft languor and 
tranfports of pleafure." 

77. Among the mammalia, the firil period of 
conception is indeed very obfcure j but generation 
has been too much conlidered as a myjiery. This 
phaenomenon is no more obfcure, and perhaps is 
lefs fo than many others that take place in organs, 
the fmallnefs or tranfparency of which makes 
them elude all our means of obfervation. 

In reprodu(5lion by flips, the adlion of life is 
continued without interruption, from one race to 
another, by means of buds or germs. Thefe are 
fmall bodies, which by their fpontaneous develop- 
ment produce beings (imilar to thofc from which 
they detach themfelves. 

In reprodu6lion, by nieans of femen or ova, the 
germs contained in thefe fmall bodies attain only 
to a certain degree of development by the influ- 
ence of the vital atflion of the mother ; and whe*- 
ther they remain attached to her, or are depofited, 
they acquire no further increafe. But if at that 
period they, receive the fecundating impreffion of 
the produd of the male organ, they again enter 



into aftion ; the (emen and ova are then exactly 
in the fame fituation as buds and germs : they ex- 
hibit different ways which lead to the fame end, 
and which produce the fame refults. 

78. In what manner does the prolific fubftance 
vivify the germ ? And what takes place at the 
moment of conception? 

This phasnomenon is not, as fome philofo- 
phers imagine, above human comprehenlion 5 but 
merely below the reach of our light ^ and we caa 
form no judgment but of things which ftrike fome 
of our fenfes. 

If one of the animalcula of the femen could 
come and tell u« what is obferved in the ovarium 
at the moment of fecundation, and during the 
iirft days of geftation, it would relate a feries o( 
fadls, which certainly would not exceed the limits 
of the human comprehenfion ; but our coarfe 
Icyes cannot perceive the hundredth part of a line, 
■ while there are organized beings, much fmaller, 
which are endowed with the powers of per- 
ception, digef^ion, and reproduflion. As we have 
no data, therefore, in regard to tbefe firfl phse- 
nomena, we fhall not attempt to give any ex- 
planation of them. 

79. Was it neceflary that the whole feries of 
beings, paft and to come, fhould cxiit in the firft 



feeds and the firft ova ? One might as well alk, 
whether the fmall vegetables, which fcarcely cover 
the naked fides of a chain of mountains, contain 
within them the immgnfe foreft which is to exift 
there a thoufand years after ^ or, whether all the 
flames by which Troj' was confumed exifted in 
the firft fpark Aruck from a piece of flint ? Iq 
all thefe phaenomena \ve ought to fee only a con- 
tinuity of adion, 

80. The germs contained in feeds and in dva, 
when once fecundated by coming into conta<5l 
>vith the lecretion of the ftialc organ, develop 
themfelves afterwards by means of a nutritive ap- 
paratus furqiOied by the female. This apparatus 
exhibits numerous varietie?, in the different clafles 
of living beings. It, however, always confifls of 
a vafcular and membranous .reticulation, which 
affords he means of circulation between it and 
the germ. Thefe two fvflems are fo connected 
thac it can hardly be conceived how they could 
have been feparated. This arrangement is one of 
the ftrongefi: proofs of the pre-exifi:ence of the 
germs in the female. The nutritive apparatus of 
the germ is developed by a continuity of the vital 
aflion of the mother. 

In oviparous animals, properly fo called, this 
apparatus may acquire its full expanfipn, whether 
the germ is to be developed or not: it then de- 


^sches itfelf from the mother, to ferve for the fur- 
ther development of the fecundated germ. 

In vegetables this apparatus does not, in ge- 
neral, attain to maturity till after the fecundation 
of the germ j it then detaches itfelf, and ferves for 
the iame purpofe as in the preceding cafe. 
, Among the mammalia, the nutritive apparatus is 
not developed till after conception ; and does not 
ferve for the increafe of the embryo, but fo far 
as it remains attached to the mother. 

In all cafes a circulation is eftabliflied between 
the embryo and the nutritive apparatus, by the 
new vital ai5iion which the germ receives at the 
moment of fecundation, 

8 1. The nutritive apparatus of the feed con- 
lifts eflentially of one or two cotyledons, which 
are continued with the germ. The cotyledons, for 
the moil part, are furrounded by a perifpcrma, 
which furnifhes them with the firft materials of 
nutrition. The whole is enclofed in a triple co- 

After fecundation, the germ and the obtyledons 
expand and increafe in the fame proportion. The 
cotyledons derive from the perifperma the fiF{l: 
nutritive juices; the covering of the feed then 
burfts J the cotyledons increafe in fize, and ac- 
quire from the earth and the air other alimentary 
fubflances, which they continue to affimilate and 


^04 riTAL FUffCTIONS^ 

to diflribute to the embryo. The radiculae and 
plumula are then feen gradually to develop them- 
felves ; and when the fmall plant is in a ftate ca- 
pable of appropriating to itfelf the nutritive mole- 
culae fuited to it, the cotyledons wither and de- 
tach themfelves. 

82. The nutritive apparatus of the ovunn of 
birds exifts chiefly in the membrane of the yolk, 
which is continued with the inteftines of the em- 
bryo. This membrane gradually abforbs the white 
fubflance of the egg, which pafTes through the 
yolk ; it then abforbs the yellow fluid itfelf; afTi- 
milates thefe materials, and tranfmits them to the 
embryo to ferve for its firfl increafe. 

In this mode of growth^ the nutritive apparatus 
isdiminifhcd in proportion as the animal increafes. 
When the latter has acquired a certain degree of 
iirength, it makes a continued vertical motion 
with its head; breaks in this manner its fhell^ 
by means of a fmall, fharp, and very hard body 
"which is above its beak; and at length ilTues forth j 
to enjoy a new life. 

As the bird, freed from its fhell, is as yet inca- 
pable of providing for its wants, it is not aban- 
doned by its mother. The latter begins to nourifh 
it with a whitifh liquor fecreted from her crop ; 
ihe then fupplies it with more nutritive aliments, 
of which (he goes in feareh. When the young 
' animal 


animal, is iirong enough to make ufe of its wings, 
it deferts its mother, and feeksfor its nouriilament 
wherever it can. 

Among birds, it is obferved, in general, that the 
male which has fecundated the ova does not aban- 
don the female, and participates in the care of 
educating the young ; he affifts in the conftruc- 
tion of the neft ; fits on the eggs in the abfenee of 
the female, and brings nourilhment to the young* 
When the education is finithed, the male and fe- 
male feparate, and the next feafon form new con-^ 

Though the development of the ova among 
reptiles, fifhes, and animals, without vertebras, has 
not been obferved with the fame care, every thing 
fpems to announce that it takes place, in general^ 
in a manner analogous to that of the ova of birds. 

Sj. Seeds and ova, in order to be developed, 
require to b^ placed in atmofpheres at different 
degrees of heat^ moifture, and perhaps of elecSlri- 

The ova of fifhes and ferpents are developed at 
the ufual temperature of the climates where they 
exift. Thofe of fome infedls, fuch as the filk* 
worm, require a flight heat; and thofe of birds re-^ 
quire a heat at leafl of 85 degrees. 

The feeds of all vegetables, and the ova of fbme 
microfgopic animals, require heat and moiflure. 



The life of Ibme fmall vegetables, and of certaiii 
inicrofcopie animals, which requires the continual 
' prefcBce of humidity, may, when deprived of it^ 
he fufpended for a period, often of corifiderable 
length, and it may refume its adivity when hu- 
midity is reltored to them, as h obferved in the 
confervtfe and the wheel infedls. 

Seeds and ova, which are developed only at $. 
♦jcertain degree of heat, can often be preferved for 
a long time, and even a great ntimber of years^- 
and again enter into action when fabje6led to that 
temperament which is fuited to them. 

This difpoiition may ferve to account for the 
ftidden appearance, as is often the cafe, of a great 
T-umber of infedls and fmall vegetables, in places 
where the prefence of organized beings v/as not 

84. Among reptiles with a naked Ikin, and the 
greater part of infedls, the animal which begins to 
develop itielf has no refemblance to that whicfif 
.gave it life :' it exhibits a different form, and other 
fyftems of organs. Thus the tadpoles df molt 
aquatic reptiles lofe their bfanchiss, their tail, and 
their whole fein j acquire four legs; refpire by 
means of lungs ; and at length exhibit an aniiiial 
entirely different, which fucceeds the firft. 

Infeds, brought forth under the form of cater-^ 
pillars, pafs. afterwards to the iiate of chryfalide ; 



and at length expand into a butterfly. This ani- 
mal, indeed, exhibits all the parts proper for un- 
dergoing thefe jtrjetarnorphofes; and it appears as if 
three different animals were developed in fuceef- 
lion. The organs of generattap are obferved pnly 
in the ftate of butterfly. 

^^, The nutritive apparatus of the germ of the 
mammalia conflfl:s, like that of feeds, in one or 
mpr^ cotyledons. Thefe organs remain attached 
to the uterus, and derive from it juices which they 
aflimilate for their development, and fof that of 
the embryo. 

In this apparatus, as in that of birds, the germ 
is immerfed jn a fecreted fluid, and retained by s 
membrane, amnios. 

In the lad place, this apparatus does not efleo- 
tially difl'er'from that of feeds and ova, but by 
being attached to the uterus. 

%6^ At the moment of fecundation, the tube 
enters into a fort of erecflipn, and its wide end is 
applied to a part of the ovarium. This organ ex- 
hibits then, in that part, a fmall tumour, which lu-* 
creafes and gradually fwells up. 

This tumour feeras :to contain only a mucous 

matter, firft whitifli and then of a redd i{|i yellow 

colour ; it aftei'wards flnks down, and the ovarium 

retains a fmaii fear.: Durmg the firfl; day^ of cpn- 

2 qeption. 


eeption, nothing is obferved in the tube but a 
fhapelefs mafs of mucous matter, which gradually 
increafes, and is conveyed Into the matrix, where 
it acquires more volume ; and which, after a pe- 
riod of greater or lefs duration, fufFers its different 
parts to be diftinguifbed. 

57. The fundion of the cotyledons or placenta 
is to draw off from the mother the nutritive juices 
•which ferve for their increafe and for that of the 
foetus, \)y means of the circulation which is efta- 
blilhed between them. 

The blood, which proceeds to the foetus, feems 
ia undergo, in its paflage through the placenta, 
changes analogous to thofe which it experiences 
in its paflage through the liver or the lungs of 
adults : it refumes there new vital properties. 

When the placenta has acquired a certain in- 
creafe or fort of maturity, and when the foetus is 
fufficiently llrong to be able to refpire, the matrix 
violently, diftended experiences pains, which forces 
it to contrail and to expel both. 

Among the mammalia, the young animal, wheg 
it ifliies from the matrix, remains attached to the 
mother by the need of ladlation ; and the mother 
herfelf is excited to empty her dugs, and beftow 
care and attention on her young. 

8S. Daring gcftation, the dugs fwell and be- 
3 - come 


come fenfible. Some days after parturition, a 
new mode of adlion takes place in thefe organs ; 
fecretion of milk is eftablifhed, and continues in 
confeqLience of the animal being fuckled. 

89. The teats differ bot4i jn regard to their 
number and poiition, in the different dafies of 
animals : in the bat, elephant, and apes, they are 
in the bread ; in moil quadrupeds on the abdo- 
men ; in cetaceous animals on the fides of the 
anus, &c. 

The teats are at leaft two in number : ruminat- 
ing animals have four, and the fow has even four- 

90. All the mammalia," as well as the other 
clafles of animals, find themfelves urged, at certain 
periods, by a defire of reproducing themfelves; 
their genital parts are then more voluminous, 
and they experience a fort of turgefcence : it 
is obferved alfo that fome females have a run- 
ning, fometimes of a reddifti colour, ft-om the 
vagina. - ; ,. 

Among raofl of the mammalia, the male re- 
mains very little attached to the female after copu- 
lation. It is however obferved ^tbat the carnive- 
rous fpecies, which experie-nce, the greateil diffi- 
culty in procuring their nourifhment, continue 
longer united ; and^mong thefe fpecies the males 
rvoL. HI. 2 B , even 


even often participate in the firft cares beftowed on 
the education of the young. 

91. Organized beings, in general, reproduce 
themfelves only by means of individuals of the 
fame fpecies : it is however not uncommon to fee 
different fpecies copulate and produce young. 
This baftard fecundation takes place, for the moft 
part, among fpecies which approach neareft to the 
fame genus ; and the individuals refulting from it, 
in the vegetable kingdom, are diftinguithed by the 
name of hyhrides ; and in the animal, by that of 
mules. Individuals produced by the copulation of 
different varieties, in the fame fpecies, are called 

It is very often remarked that hyhrides, mules ^ 
and mejlefe, are Wronger than the individuals 
which produced them ; and this circumftance has 
fhown the advantage of croffing the breed. 

Hybrid plants are fruitful and multiply their va- 
rieties. Several botaniils, however, ailert that the 
germinating property of feeds which arife from hy- 
brid plants does not extend beyond the fecond' 
generation - 

Mules, "among birds, are generally capable of 
reprodu61ion. Among the mammalia, they lofe 
this property, and remain barren. 

Meftefe reproduce themfelves, with the pecu-s 
liar charaders of their variety. 



Hybrides, mules, and meftefe, generally have a 
relemblance to the mother in their interior and 
fundamental parts j and to the male in their ex- 
terior and acceflbry parts j which tends to prove, 
that the germs pre-exifted in the female, and that 
the male, by fecundating them^ could only modify 
them faperficially. 

Every peculiarity of fl:ru(5lurej every defeiSl of 
conformation, and even every organic difpofition 
or aptitude for certain faculties, is fufceptible of 
being at length tranfmitted by t/he way of genera- 
tion. It is in confequence of this property that 
the fame forms and the fame qualities are preferved 
in plants, and in teveral races of animals, as dogs 
and hories ; and that certain organic maladies 
are perpetuated, fuch as the bunch of the ele- 
phant, &c. 

The crofiing of breeds, efpecially if the moll 
beautiful females be chofen for that purpofe, is the 
beft means to correct, in the fpeediefi: manner 
poflible, eflential organic defeats, and to obtain 
races Wronger and more beautiful. 

Culture or education, by which organized beings 
are continually modified, and generation which 
tends to propagate the changes produced, are the 
two means which may powerfully concur towards 
the improvement, as well as the degradation of 
fpecies, according to the manner in which they ar$ 
dire(5led. ^ 

2 B 2 92. What; 


92. What has been faid, in general, on the 
reprodu6lion of all organized beings, and on that 
of the mammalia in particular, is applicable to the 
human fpecies. In the examination, therefore, 
of that funcftion, we fhall take notice only of the 
principal, fa6ls which feem more particularly to 
demand our attention. 

The period of puberty is announced, in both 
fexes, by very remarkable changes: in girls who 
have attained to the age of 14 or 15, or fooner or 
later according to the climate, it is obferved that 
the giddinefs and livelinefs of early youth de- 
creafe, and that they become more thoughtful. 
The bofom begins to fvvell, and gradually 
acquires a greater volume ; the pubis is covered 
with down ; the pelvis completing its expantion, 
aflumes its proper form, and menflruation com- 

In boys, the period of puberty takes place two 
or three years later ; they become lefs boiflerous, 
and acquire a more ferious turn ; the voice pafles 
from acute to grave, and becomes an odave 
lower ; the quality of the tone often entirely 
changes ; the genitals are covered with hair, and 
experience a fort of inflahtaneous atid painful tur- 
gefce nee, 

Man is irrefifiibly urged to reproduction, as 
well as to felf-prefervation, by the painful fenfation 
of rieed ; and the plcafure he experiences in fatis- 



fying that need induces hiril to repeat often the 
a6t of reprodu6lion. 

If young perfons of a ftrong conftitution, unin- 
formed, and who live in a flate of idlenefs, be 
carefully obferved at the epoch of puberty, when 
the organs of reprodudlion begin to acquire their 
full development, it will be found that they ex- 
perience a fort of tranfient languor, dejeftion, and 
exaltation ; this ftate is continually renewed, and 
foon becomes very painful. They experience inf 
the genitals a fort of heat and uneafy pruritus, 
which obliges them to fix their attention on this< 
i)'flem of organs ; this uneafmefs, which becomes 
more and more infupportable, induces the fexes to 
approach each other, and the painful fi:ate which 
they experience, and which they naturally wifh to 
get rid of, condu(fl:s them at length to the a6t, of 

In the human fpecies, it is not obferved that the 
delire of reproduction is renewed at certain periods. 

It is however probable that this peculiarity is a 
refult of civilization ; that in the ftate of nature 
there are fome periods more ftriking in this re- 
fpe6l, and that, in women, they correfpond with 
thofe of menftruatLon. 

93. According to numerous experiments and 
obfervations ijiade by Haller and others on ani- 
mals, for the purpofe of throwing more light on 
2 B 3 the 


the pbsenomenon of reprodu6lion, it rcfnlts that, 
during copulation, the uterine tube experiences a 
fort of eredion, and that the broad end of it is ap- 
plied to the ovarium. 

It is probable that in this fl:ate the prolific fluid 
proceeds to the ovarium, traverfing the uterus and 
the tube, and that it effects the fecundation of one 
or more germs, contained in the fmall veticles 
correfponding to the part of the ovarium to which 
the wide end of the tube is applied. 

The quantity of fperm neceflary to efFeft fecun- 
dation muft be infinitely fmall ; for under fome fa- 
vourable circumftances the vapour or even odour 
of that fubflance, conveyed into the ovarium, 
feems to be fofficient to communicate to the germs 
a vital movement. 

Some days after conception it is obferved, that 
one of the.veftcles of the ovarium fwells ; it then 
buriis, and the vifcous fluid it contained' enters 
the tube. The cicatrix refulting from this rup- 
ture is gradually formed, and-always leaves a fort 
of tubercle with a yellow fpot. 

The cicatrix and the yellow fpot -indicate, in 
general, that fecundation has taken place. . Thcfe 
figns, however, are obferved fometimes in young 
women, who have remained barren. Swammer- 
dam afcribes this phsenomenon to fterile carefles 
or folitary enjoyments : this ftimulus of pleafure 
mull make the germ Jburfi: its flrli. -covering and 



enter the tube, where It foon withers, in confe- 
quence of not having received the impreffion of 
its fpecific irritant. 

The germ which enters the tube, and which as 
yet appears under the form of a mucous body, de- 
fcends along the tube, and proceeds into the 
uterus, where it remains and acquires develop- 

Sometimes the fecundated germ, inftead of en- 
tering the tube, defcends into the abdomen and 
there expands : the germs have been found alfo to 
develop themfelves fometimes in the ovarium, or 
•in the uterine tube ; and in all thefe cafes parturi- 
tion, by the ufual parages, becomes impoffible. 

The development of the foetus appears at firft to 
be flow J but it feems afterwards to increafe in the 
ratio of the volume which it acquires. At the end 
of the firft month, it is fcarcely a few lines in 
length ; but towards the end of the fecond it is 
nearly two inches ; at three months it is three or 
four ; at four months five or fix; at five months 
fix or feven ; at fix months eight or nincj at feven 
months nearly half a foot ; at eight months from 
fourteen to fifteen inches ; and at the period of 
birth it is eighteen inches. All thefe dimenfions, 
however, are liable to much variation. 

The chorion, which at firft has a cottony ap- 
pearance, the amnios which fecretes and contains 
the liquid in which the embryo floats, the placenta 

B 4 which 

376 VITAL Functions. 

which is attached to the fides of the uterus ta eix- 
tra6l juices from it, the umbilical cord which efla- 
b])fhes a communication between the fcetus and 
the placenta, all expand fimultaneoufly, and in- 
creafe in the fame proportion as the fcetus. 

As the embryo develops itfelf, the parts which 
compofe it can be diftinguifhed. Thus when it is 
nearly an inch in length the head forms the half of 
its volume J the eyes are marked by two black 
points, and the place of the mouth is indicated by 
a broad tranfverfe fifTurci the four limbs arife 
from a fmall fhort trunk, and are very near each 
other; but as it increafes, the form of the parts is 
better defined, and they gradually approach that 
type which they are deiiined to retain. 

When the foetus has acquired a certain fize, 
and the placenta has attained to a fort of maturity, 
the uterus which is flrongly diftended contra(5is; 
and by a fimultaneous ad ion of that organ, of the 
diaphragm, and of the mufcles of the abdomen, tlj^ 
child burfts its coverings, and ifilies, in general, 
with the head forcmofi:, and the face towards the 
facrum. After it comes forth, the uterus, which 
flill continues to contract, expels^the placenta and 
its appendages. 

After deli\ery, the uterus flowly returns to its 
former (late; its tides. decreafe in thickr.efs ; dur- 
ing its contradiion it excretes a liquid at lirft fan- 
guinolent and then ferous, which gradually dimi- 

nifhes ; 


nifties; and this organ by little and little is reflorcd 
to its former condition. 

94. But towards the breads another feries of 
phaendmena, no lefs important, foon takes place. 
Thefe organs, which during geftation remained in. 
a fort of continued turgefcence, fwell up, become 
painful, and a fecretion of milk begins to be efta- 

The relation which ex ifts between the uteruS 
and the breafts can be explained neither "by the 
diflribution of. the nerves nor by that of the veflels, 
Thefe organs, in their refpe6live functions, tend 
towards the fame end ; that is, the nourifhment of 
the child. This common property renders them 
dependent on each other, and when they enter 
into ad^ion, caufes them to have a reciprocal in- 

The arteries diftributed to'^the breafts fur nidi 
the materials neceliary for the fecretion of the 
milk. There is no fufficient reafon for believing 
that the organization here follows its habitual 
courfe, and that this fluid arifes from the chyle. 

At the period of lactation the breails fwell ; the 
arteries are dilated, and eaiily fupply the quantity 
of blood neceflary for the fecretion of the milk; 
and the materials which have not been employed 
for that fecretion return by the fanguiferous veins 
and the lymphatic veiTels, the latter of which are 



exceedingly numerous, as in all the fecretory 

On the lecond or third day after delivery, the 
fecretion of the milk is completely eftablifhed. 
This new fundiion is announced by a general 
change of ftate, a fort of febrile crifis, more re- 
markable in women of a weak conftitution. 

The fecretion of the milk, in general, takes 
place fpontaneoufly ; but the greater part of this 
fluid is fecreted while the child fucks. 

That the milk may be fecreted in abundance 
and with facility, the mother muH: be placed in a 
particular and habitual fituation ; the muft have an 
affedion for the child ; and the latter muft: have 
acquired the habit of ftimulating the breaft by a 
proper mode of fucking*. 

When a nurfe prepares to fuckle the child, (he 
Ibmetimes experiences in the breads a fort of or- 
gafm or turgefcence; and fhe has a fenfation as if 
fbmething were proceeding towards them^ which 
induces her to ftiy that the milk afcends. 

In young women, and even in men, a fecretion 
of a fort of ferous matter, more or lefs abundant, 
but which does not exhibit the qualities of good 
milk, has been fometimes produced in the breails 
by repeated fucking. The quantity of milk fecret- 
ed is not proportioned to the fize of the brcafts, 

^ See BordcUi TrakS de^s Glandes, 



but to the vital energy of the gland which effects 
the fecretion. 

The beft milk is that fumifhed by a healthy 
nurfe of a gentle difpofilion, who leads a tranquil 
life and ufes proper food. 

All fudden derangements which take place in 
the organization, produce changes in the quality 
of the milk. Whenever the fecretion of the breafts 
is diiiurbed by any caufe whatever, it is obferved 
that its produdl becomes aqueous, and that it ac- 
quires a ftimulating property, often very remark- 
able, on the digefrive organs of the child : the 
latter then experiences colics, or is feized with 

I have often had occafion to remark, that when 
the fun(5tion of a fecretory organ is deranged, its 
proda<5t exhibits ftimulating properties of greater 
or lefs ftrength. 

Several phyficians have imagined that the pur- 
gative property of certain rriedicines is conveyed 
from the mother to the child, becaufe the latter is 
fometimes purged when the nurfe takes any laxa- 
tive fubftance; but this phaenomenon arifes merely 
from the fecretion of the milk being difturbed in 
confequence of the general derangement produced 
by the purgative. The child may be purged 
when the mother has experienced great fatigue, 
a violent fit of paffion, or any caufe of derange- 



ment whatever. The child is the more fenfible to 
the different alterations of the rnilkj the vve*ker 
and more irritable it is ; but when robuft, and 
when its gatiric organs are in a good ftate, it is 
Bot eafily afFedled by the changes which may 
take place in the quahty of that i^uid. 

The fecretion of the breafts is difiurbed alfo 
when the uterus experiences a new mode of ac- 
tion. It frequently happens that a fiirong nurfe, 
of a fanguine temparament, experiences the men- 
Urual flux during iacStation : it is then firft ob- 
ierved that the milk flows more abundantly ; that 
it is clearer, and that it produces an irritating ac- 
tion in the digeftive apparatus of the child : but 
this effe£b is only momentary, and the milk foon 
refumes its former qualities. 

When a nurfe becomes pregnant, her milk is 
at firft fomewhat turbid^ but it foon returns to its 
former ftate ; it is only obferved that it decreafes 
in quantity as geftation advances, fo that a nurfe 
may, without inconvenience. Continue to fuckle 
during her pregnancy, as long as fhe is able to 
undergo the labour without fatigue. 

When any coniiderable derangement is pro- 
duced in the organization, or in the nervous ac- 
tion, or when a febrile ftate takes place, the 
breafts fink down, and the fecretion of fhe milk 
is often fuddenly fufpended. 

95. PhilO"' 


95. Philofophers have at all times made re- 
fearches to afcertain whether the human race has 
dercended from one fpecies, or whether there were 
originally feveral ; and if this was the cafe, of 
what kind they were. It is probable, that a great 
deal will be written on this queftion, before it be 
reiblved. I fhall therefore only offer a few re- 
fiedrions on the fiibje£t, which will ferve to give 
the reader fome idea of vvhat nature it is. 

The claffification of organized beings is not a 
matter of abftradlion and convention: orders and 
genera exiil for plants, independently of all fyfl:emi 
and method, iti what botanifts call the natural fa- 
milies ; and the greater number of vegetables are 
arranged in thefe families. 

Naturalifts ought to enter into an agreement to 
comprehend, under the denomination of genus, all 
individuals /i{fceptiMe of co^puJatmi and reproduc- 
tion, as the etymology of the word feems to in- 
dicate. There could then be no difpute in re- 
gard to the fignification of this tei'm, fince it would 
only be the expreflion of a fa<5l which might 
cafily be verified. 

The individuals of a genus, which exhibit parti- 
cular chara6lers, and which are fufceptible of 
.being preferved by means of generation, compoie 
a fpecie&s 

When individuals of two fpecies of the fame 



genus copulate, the refult may be a proda6l with- 
out a perfedl refemblance either to the father or 
to the mother, and having new characters. If 
thefe characters are preferved by generation, the 
individuals which exhibit them conftitute a new 
Ipecies. On the other hand, if they be effaced, 
and if the individuals of the fecond race refume 
the chara6ters peculiar to the firil: progenitors, 
they are called varieties, or nmjiefe. in the lafl 
place, when the products of two different fpecies 
cannot be perpetuated they are called hyhrides or 
mules. Thus man, in regard to the colour of the 
fkin, exhibits three diftinft fpecies (the white, th& 
yellow, and the black), fufceptible of being pre- 
ferved in all climates. 

It is known that certain peculiarities of organi- 
zation, , which have taken place accidentally or 
in confequence of the long continued influence of 
climate, of nourifhment, of habits, or of many other 
unknown circumftances, may be afterwards perpe- 
tuated by generation ; fo that it is poflible there 
may originally have been only one human fpecies, 
and we are difpofed to believe that it was ex- 
ceedingly beautiful ; but the man of nature, like 
the pear-tree of nature, was a wild being, fuccef- 
iively improved by culture and grafting. 

96. In my opinion, it would be difficult to de- 


termme, at prefent, which was the firft breed of 
the canine race ; and I do not think that any one 
ever ventured to fay, that we may fee it in the 
fineft dog of the Daniih breed. The fineft and 
moft beautiful dogs and horfes refemble the cul- 
tivated pear*»lree and the civilized man. 

The promptitude with •which all thofe fpecies 
or varieties of dogs which we daily fee have been 
produced, is a circumftance very remarkable. A 
moment's refledion on the caufes which concurred 
to produce them will furnifli valuable fads, for 
enabling us to comprehend what may take place 
by the effed of croffing breeds. 

In a large city, fuch as Paris, there is an immente 
multitude of dogs of all kinds, which are modified 
in a thoufand ways by varied mutilations, by the 
life made of them, and by the kind of life t0 
which they are fubjededj, &c. Thefe dogs are 
always wandering about, and copulate without 
regard to colour, fize, or quality. Thefe conti- 
nual mixtures, fo often repeated, have produced 
numerous fpecies and varieties, the primitive types 
of which it is now impoflible to diftinguifh. Among 
thefe numerous fpecies, fome remarkable for the 
greatnefs or fmallnefs of their fize, their plump 
or flender form, and the great variety of their co- 
lour, have foon been obferved. It would be re- 
marked, alfo, that fome of them fhewed more 
3 ' aptitude 


aptitude for certain things, and greater intelli- 
gence in certain exercilt.\'<. - Thole which people 
withed to procure would then be feparated, and 
made to copulate with their fellows ; the qualities 
for which they leenied to have the greateft apti- 
tude would be cultivated ; and in this manner 
would be obtained the fhepherd's dog, the dif- 
ferent dogs for hunting, and even fmall lap- 
dogs. The fame number of fpecies arc not to be 
found among horfes, becaule the breeds have not 
been crofled in fo varied a manner. 

By continued copulation between fele6l indi- 
Yiduals, that apparent equality which feemed to 
prevail between thofe of the fame genus is foon 
deftroyed ; and every fine fpecies, fulceptible of 
being preferved without alteration, when care is 
taken that they may not be degraded by any mix- 
ture with individuals of an inferior quality, are 
obtained. Thefe fine fpecies really form noble 
breeds ; and it is always obferved, that it is chiefly 
by the females that the qualities of thefe fine 
breeds are perpetuated. 

Thus, in Arabia, between Bagdad and BafTorah, 
feveral breeds of horfes, diftinguiflied by charac- 
ters well known to amateurs, are carefully pre- 
ferved, without any mixture. The birth of the 
individuals produced from thefe breeds is attefted 
by a public adlj which particularly mentions all 



the maternal genealogy, and ferves as a patent of 
nobility to the animal ; but this nobility is tranf- 
mitted and preferved only by the females, the no- 
bility of the males being merely individual *. 

Species ftill finer would, in all probability, be 
obtained by croffing the moft diftinguithed breeds; 
for by preferving them without mixture, they are 
not only prevented from being improved, but 
muft even be fenfibly altered in the courfe of 
time, in confequence of many particular circum- 

But, however this may be, all thefe ideas, in 
regard to the nobility of horfes, are much more 
rational than thofe which ferve as a bafis to the 
nobility eftabliihed among animals of a fuperior 

97. Among men analogous circumftances have 
produced timilar efFedls. The inhabitants of the 
different countries have been flowly modified by 
the influence of climate, nourifhment, exercife, 
habits, civil and religious cuftoms, &c. When 
the population in a diflri($l became too numerous, 
men united in fociety, and when they attained to a 
certain degree of civilization, they attempted emi- 
grations, and made war on diflant tribes, who by 

* See jfournal de Ph^jijique, torn. 1. 

VOL. Ill, 2 c circum- 


circum fiances, often very different, had been mo- 
dified in another manner. Individuals of different 
varieties would thus be united, and their mix- 
ture muft have produced a new fpecies. Events of 
this kind were fo often renewed, that the numer- 
ous fpecies and varieties now exifting mull have 
been the neceffary refult. But among thefe dif- 
ferent fpecies, fome were found to polTefs a very 
evident fuperiority of organization, and fhewed ^ 
more rapid progrefs towards improvement : others 
retained remarkable charadlers of inferiority and 
degradation ; fome alfo feem to have been check- 
ed by circumfiances of climate, food, drefs, &Co 
and are nearly in the fame ftate as that in which 
they exifiied a thoufand years ago. 
- Amons: the different races of men, there are 
three, in particular, which exhibit very diflin(5t 
chara<2ers and a very remarkable organization. 

lit. The v>?hite race, which have a white {km, 
tall ftature, head oval, cranium well expanded, 
the nofc lengthened, the facial angle eighty- five 
degrees, the hair fine, commonly of a chettnut co- 
lour, and which are in an advanced flate of im- 

ad. The tawny race (Mogul),- which have the 

ikvn of a copper-yellow colour or tanned, the face 

broad, the eyes a littk towards the fides, the 

cheek bones proje{3ing, the nofe flat, the chin 

^ {harp- 


ftiarp-pointed, the hair thick, flat, and black, 
Hature fliort, cultivation lefs advanced. This race 
inhabit the greater part of the globe, and are 
found in almoft all climates ; but more particu- 
larly in a great part of Alia, in America, in the 
iflands of the South Seas, and as far as the frigid 

3d. The black race, which have the Ikin of a jet 
black colour, the flature long and flender, the 
hair fhort and woolly, the forel/ead flat, the nofe 
flat, the jaw bones proje£ling the lips thick, a 
great mobility of face. They inhabit Africa. 

The colour of the flcin, which Turn ifl:ies the 
moft fl:riking charader of thefe three races, may 
have been the fefult of the long continued influ- 
ence of climate ; but, in the courfe of time, it 
aflTumed an organic charadler, which is preferved 
without alteration in all latitudes. 

98. The mofl: remarkable phasnomenon in the 
a<5l of reprodudlion is the tendency which the 
generating individuals have to tranfmit, not only 
the peculiarities of their organization, but alfb 
a difpofition to certain difeafes to which they 
were fubjedl, or an aptitude for certain facul- 
ties, which they had acquired. This property 
daily contributes to the degradation and improve- 
ment of the fpecies according to alliances. , 

51 C 2 It 


It is of importance to repeat, alfo, that the in*- 
fluence of the mother is more remarkable on the 
eflential and interior organs of the child; that 
the influence of the father appears chiefly in the 
exterior and acceflxDry parts ; and that, in general, 
the fpccies is improved by croffing the breed. 


[ 389 ] 



99. The vital power, like that of affinity and 
attradlion, is univerfally difFufed. It is completely 
exercifed only on organized bodies at a certain 
degree of thermometric, hygrometric, and elec- 
tric, &c. temperature j and by a continuity of ac- 
tion on flips or fecundated germs arifing from 
thefe bodies. 

When an organized body is thus properly fub- 
jefled to the vital power, it pailes through a le- 
ries of phenomena which conda6l to a fort of 
maturity. At this period, its parts, which are no 
longer in a proper relation of organic ftrudldre, 
remain completely fabje-l to the power of affinity, 
which combines them according to its peculiar 
manner, and caufes the remains of its decompo- 
fition to return into the general grand circula- 

Organized and Hving bodies are not completely 

free from the influence of the force of affinity ; 

but the latter being lefs powerful than the vital 

a6lion, does not begin to manifeft itfelf by any 

205 pbasnemena 


phaenomena of decompofition, until the vital ' 
power becomes too weak^to retain the moleculae 
of matter in a proper ilate of organic ftru(5lure. 

The fi:rr.6lure of every organized body feems 
to confift in a vafcular reticulation, in the midft 
of which matter^ by circulating, may afTume that 
indefinite degree of divifibility, necellary for main- 
taining the phacnomena of nutrition. 

Thofe organized beings which appear to be 
limpleft, fuch as vegetables and zoophites, have 
at leail: fyflems of nutrition and of reproduc- 
tion. Thefe two fyflems are not concentrated, 
but multiplied and difleminated throughout all 
their different parts. This difpofition permits 
thefe beings to be divided into feveral portions, 
which increafe and multiply feparately. 

But in proportion as we afcend towards be«. 
ings of a more compound organization, it is ob- 
ferved that the fyftems of the organs increafe, that 
they ceafe to be multiplied, that they are con- 
centrated and diflind, and that the living body 
can no longer be divided without perifhing. Of 
all animals, man appears to have the centres of 
his organs moft clofely connc6ted. 

Iji living bodies the vital power caufes parti- 
cular functions, which depend on their organic 
mode of ftru dure, to be executed; but it main- 
tains in them all a common and uniform a(Siion, 



which conftitutes the efletitial pbeenomenon of 
life. It is indeed obferved, that all the molecule 
of matter which compofe thefe beings are in a con- 
tinual flate of motion, during which they are 
driven off, and their place is gradually fupplied 
by others, which afTuine a different arrangement, 
remarkable at the different periods of their life. : 

The extreme degree of divifibility or decom- 
poiition to which matter may be brought in the 
organs;, its converfion into the proper fubflance 
of thefe organs, the place of which it continu- 
ally fupplies "with different modifications, are phse- 
n.omena, the mode of which is unknqwn to us 
becaufe it efcapes our obfervalion. 

If we reflect, for a moment, that we obferv€ 
animalcula not mor^ than the two or three hun- 
dredth part of a line in magnitude^ which are ge- 
nerated, ir^creafe, move, and reproduce them- 
felves; that it is probable that in each j?oint of 
the organization of thefe beings changes are ef- 
fedted, in a manner analogous to thofe of the 
greatell living bodies ; that it appears that matter 
in both affumes the fame degree of divifibility, 
^nd that nutrition is pei:forraed with organic in- 
flruments of the (ame fize,:_U, may readily be 
conceived how far our eye, armed with the belt 
inftrument yet knov/n, is from being able to pene- 
trate thither in order to obferve what is taking 
place. Thus, the phasnomenon of nutritition is 

2 c 4 con-' 


concealed from us in that infinite minutencfs, 
which is beyond the reach of our coarfe organs, 
fo that we are acquainted only with the refults of 
that operation. 

Living bodies, independently of their organs 
of nutrition, are provided alfo with parts fpeci- 
a1]y defl:ined for receiving the impreffion of ex- 
ternal objects. Thefe fyftems of the fenfes, the 
form of which varies, always conftirute an organ 
of touch, more or lefs extenfive and delicate; 
and this organ is conftantly found even in plants. 

Every organized being has the power of placing 
itfelf, in the furrounding medium, in that pofi- 
tion which is moft favourable to its organization ; 
and it is indeed obferved that vegetables pufh 
their roots towards the moid earth, and turn 
their ftems towards the lights as animals fearch 
for thofe fubflances which are propereft for their 
nouriQiment. * 

A flate of fuffering or of eafe is remarked in 
all living bodie?, and even in plants : to the ob- 
ferving naturalift, the appearance of a vegetable 
which fufl^ens, or which acquires a vigorous deve- 
lopment, is as exprcffive as the cry of fatisfaftion 
or of pain e?nitted by an animal. 

When the functions are not performed in a 
proper manner, for want of thofe things which 
are nrceflary to the fupport of life, there takes 
place in the organization a ftate of change, which 



conftitutes the painful fenfation : it is the fii ft 
which animals feem to experience. 

This fenfation of uneafinefs or of want excites 
animals, in an irreliftible manner, to adiofi, for 
the fike of their own prefervation, and for the 
propagation of their fpecies. ' The fenfation of 
eafe which they experience, in fatisfying this want, 
becomes afterwards a itimulus, which excites them 
to the repetition of the fame ad. 

The adion of foreign bodies on the oi'ganiza- 
tion may produce a change of ftate analogous to 
want, and thus give rife to a .painful fenfation, 
which the animal is powerfully incited to free it- 

feif from. 

In proportion as an animal expands, experi- 
encing alternately painful and agreeable lenfa- 
tions, it becomes fit to appreciate flight and 
tranfient changes of ftate, which in fome mea- 
fure are indifferent to the order of the fun<5lions. 
Every thing that ftrikes'the organs of the fenfes 
may prqduce fenfations of this nature. 

In animals, the organic fyfi:ems, by habitual 
^xercife foon contra(il a great aptitude for dif- 
charg'ng the functions peculiar to them. This 
aptitude is flill increafed by the reciprocal aid 
which they lend to each other in their indivi- 
dual and fimuUaneous adtion. 

The faculty which the organs have of receiv- 
ing external irnpreilions, capable of producing a 



change of ftate which conftitutes fenfation, is an 
organic function, which by exercife and the force 
of habit becomes ftill fufceptible of being per- 
formed with more facihty or fpeed. 

Thus a fenfation produced feveral times in 
au organ of the ienfes, by the impreflion of an 
external body, may be afterwards completejy 
renewed, without the prefence of that objedl, 
merely by that of any accefibry circumftance^ 
which accompanied it and which is renewed. 
From this it refults, that the fenfations experi' 
enced are not entirely loft, though they be ef- 
faced, lince they can be thus renewed by aeeef- 
fory circumftances, and even be recalled in fuc- 
ceffion, according as they are more or lefs inti- 
mately connected. This faculty, which is ob- 
ferved in all animals, in a greater or lefs degree, 
furnifhes the principal means of improvement. 

An animal, indeed, which is continually excited 
to a(^ion, in order to fatisfy its wants, and whofe 
paft fenfations may be repeated in confcquence of 
new fenfations, finds itfelf poflefied of futScient 
means for comparing thefe different fenfations, for 
comhining them, and for thus forming a judgment , 
in confequence of which it determines to ad in a 
manner belt fuited to its prefervation. 

If to this be ftill added, that the animal has a 
ilrong tendency to a(Sl by imitation and by the force 
of habit, and that the modifications which refult 



from the varied ufe of thefe faculties may be 
tranfmitted, at leafl in part, by the way of gene- 
ration, we {hall have the fa m of the means which 
concur to the produ61ion of organic phsenomena, 
and which tend^tp the progrefs of improvement. 
Every animal, indeed, is fufeeptible of individual 
improvement, more or lefs extenlive, and in this 
manner acquires a fort of experience. 

I GO. The different iyftems of organs in man, 
taken together, form a being, who can move 
from one place to another, and place himfelf in 
relation with every thing around him. His organs 
of the fenfes render him fentible to the impreffion 
of the light, either diredl or reficdled ; to that of 
the air in a ftale of vibration, and of odorous and 
iapid moleculse ; and to the contatl of all bodies 
of a certain mafs and denfity. By means of a 
Very extenlive fyflem of organs, he affimilates to 
his owtf fuhftance atmofpheric air, water, and all 
materials ariiing from organized bodies, in the 
laft place, he reproduces hunfeltj by the con^ 
courfe of a collection of parts, which are in two 
feparate individuals. 

AH thefe fyftems of organs, exceedingly various, 

are effenlially formed of veflels aud nerves, having 

commdn centres on which their continual a(51ion 

depends J 1<) that the organization is compofcd 

.'4*iS/ '^n* of 


of parts, which conftitute a whole necefTarily 
continued. The veflels and nerves, by their varied 
and numerous interfeclions, form different tiffues 
of organs. 

The interior parts of the vefTels and the cells, 
refulting from their different tiflues, contain ferous 
and fanguine fluids ; albuminous, gelatinous, 
adipofe, faline, &g. fubftances ; and, in general, 
every organic material of which the veffels and 
nerves themfelves are formed. All thefe fub- 
ftances are continually penetrated and traverfed 
by eleftriciiy, light, caloiic, &c. 

Each point of the organization may be confi- 
dered as a fecretory organ ; the parts in their con- 
tinued adion experience a change of ftate more 
or lefs remarkable: after having acquired their 
full development, they gradually lofe their pliabi- 
lity ; matter is accumulated in them ; the conti- 
nued motion of fecretion and abforption is no 
longer performed with the fame aflivity ; the or- 
ganic moleculss move in them only in a flow 
manner, and at length arrive at that f^ate of reft 
which conftitutes death. 

The whole of thci organization may thus be 
conceived as confined to a life merely vegetative 
or animal, in which each point arrives at a certain 
degree of development, of maturity and death, 
by a continuity of motion and fJicretion. Thus, 



in fome cafes of very exrenfive palfy, attended 
with imbecility, man is reduced to an analogous 
exiftence, entirely deprived of relative life. 

In this cafe, the exiftence feems to be main- 
tained only by the ganglions of the trifplanchnic, 
by means of the nerves of that apparatus, which 
accompany all the veflels, and which are diftri- 
buted to the principal organs, not fubjed to the 
empire of the will. 

But each point of the organization, independ- 
ently of its particular life, enters into the compo- 
lition of a lyftem, which performs its fun6lions 
only by means of the particular nerves which pro- 
ceed to it from the brain, or from its vertebral 
prolongation. In a word, the fimultaneous ac5lion 
of the different fundions produces the beautiful 
phaenomenon of the human organization. 

In this phaenomenon, it is of importance not to 
forget, that each organ is elientially an inftru- 
ment of fecretion ; and that in the exercife of 
this funftion, the arteries fupply the materials and 
the nerves the principle of a6lion. The heart 
and the arteries, by their continual contradion, 
propel the blood to every part of the body ; this 
movement is maintained by the prefence of the 
blood in thefe parts, and by the influence of the 
nerves which are diftributed to them. The ce- 
rebral organ, being itfelf an organ of fecretion, 
requiresvfor the exercife of its fun6tion a conti- 


Dual fupply of arterial blood ; fb that thefe two 
principal organs of life have evidently a mutual 
dependence on each other. 

The organs, in confequence of the different 
excretions, are continually fullaining a lofs : this 
lofs is repaired by means of fubflances conveyed 
to them from without ; and for this purpofe the 
organs are in relation with all external bodies. 
Hence it is obferved, that they are differently 
affected according as the objedls which ftrike 
them are favourable or hurtful to the whole phas- 
nomena of the functions. 

In man, as well as in animals, the change of 
flate which takes place in the organs, by the im- 
preffion of objects, which tend to difturb or to 
maintain the order of the functions, conftitutes 
the painful or agreeable fenfations. The impref- 
fions he receives may be completely renewed, 
without the prefence of the objeft from which 
they were firft received, but only by that of fome 
acceilbry circumftances connected with it. By 
thefe means, he acquires the faculty of avoiding 
obje6ls which have produced in him fenfations 
deftru6live of his organization, and of placing 
himfelf in circumflcinces favourable to his prefer- 
vation. The combined exercife of thefe firtt fa- 
culties, and the exteniion of them, give rife to 
the development of the underftanding. 
'■ The fyllems of organs are of three orders : ift. 



Of relation : 2d. Of nutrition : 3d. Of repro- 

1 01. Man^ in confequence of the ftrudure of 
his limbs, tranfports himfelf from one place to 
another ; removes from objedls which hurt him, 
and aproaches thofe which are favourable to him.- 

Of all the mammalia, he has, without doubt, 
the mod advantageous form, as properly fpeakirlg 
he is the only biped, which enables him to pre- 
ferve with facility a vertical pofition, by placing 
the whole fole of his foot on the ground, and ex- 
tending completely his ham. His pelvian limbs 
are provided with large mufcles, and the fwelling 
or dilatation produced by thefe mufcles exclufiveiy 
in him, add to the beauty of his fhape and to the 
flrength of the parts. 

The thoracic linibs are not impeded by walk- 
ing ; and may hie employed for the nobleft and 
moft important purpofes. 

His head is almoft in eqUilibrio on the vertebral 
column, and his eyes are turned dire6lly forwards. 

The difpofition of the mufcles allows the limbs 
to perform the moft varied and moft ejttenfive 
motions; and it is aftonifhing to fee with what 
force and agility thefe motions are performed by 
fome perfons, in confequence of a peculiar or- 
ganic difpolition and proper exercifs, 

3 Th» 


The ilrength and pliablenefs of tumblers, tlie 
lightnefs and agility of dancers, the furpriling 
quicknefs of the fingers of the organifi:, are al- 
ways the more aftonifhing, as the anatomical 
iftrudiire is not fufficient to account for it. 

The mufcular Itrength, difplayed by fome in- 
dividuals of an athletic conformation, and the vio- 
lent action of the mufcles in certain ftates of 
paffion or of difeafe, evidently fhow that an ex- 
planation of the phaenomena of life are not to be 
fought for in the laws of natural philofophy. 
Meao;re and debilitated females are often feen 
to break the ftrongefl cords, and to drag after 
them enormous mafles, during paroxyfms of hy- 
fterics, or of mania. A mufcle may then over- 
come a refiilance by which it would be broke in 
the ftate of death. 

The mufcular tyflem abfolutely requires employ- 
ment : it appears to be that vihich confumes, in the 
manner moll proper for health, the quantity of that 
principle of a6lion which the brain diflributes to 
every part of the body by means of the nerves. 
The habitual inactivity of this fyftem always pro- 
duces greater or lefs derangements; it is one of the 
moft frequent caufes of the chronic difeafes which 
prevail among the idle claffes in large cities. The 
habitual exercife of the mufcular fyllem confumes 
the llrength more than that of any other ; and 
* therefore 


therefore men continitally employed In fevere la- 
bours are the lead proper for any other funftion. 

The mufcleSj like the other organs, have a great 
tendency to exercife the funclion peculiar to them, 
at the fame time, in the fame manner, with the 
fame degree of intenfity, and in confequence of 
the fame recolle(51ed objeSs : this couditutes 

The tendency to habit, which allows the repe- 
tition of the fame a61ions with more promptitude, 
addrefs, and facility, is one of the great (iaufes of 


102. As the -organs, of the fenfes bring us into 
a more dire6l relaitiein with the furrounding ob- 
jeds, thefe objects, by their varied a6lion on our 
organs, unveil to us a part of their properties. 

103. Man fees illuminated objed^s of a certain ' 
lize, and at. a certain diliance, by means of an or- 
ga'n, the conftrnftion of which is lim.ilar to that of 
the camera obfcura. The luminous rays refle<5ledi 
from objects and refrad:ed by the humours of the 
eye, proceed to the retina, and there trace out the 
image of it, in an inverted polition. 

The fenfation which the individual experiences 
by the impreffion made on the retinp, is not that of 
an image painted in the bottom of the eye ; for in 
that cafe another eye would be neceflary to look at 

YOL. HI. ID it; 


it ; nor of an objecfl inverted which i^ places in its 
proper pofilion ; for he has no idea of up or of 
down, nor of right and left of his retina ; but a 
fenfation of touching, which refuUs from the con- 
ta6l of the different luminous points with the 
retina, in an order determined by the form of the 

The fenfation of fight is the moft important, 
lince it brings man -inftantaneoufly into relation 
with very diftant objedls ; but it is alfo the mod 
uncertain fenlation. 

Sight indicates only the form and colour of bo- 
dies : it is by approaching and touching them that 
we can judge of their diftance and magnitude ? 
and, notwithftanding our daily experience in this 
refpec^, it often leaves us in a ftate of uncertainty, 
from which it is impoilible for us to free our- 
felves. , 

The rays of light, in their progrefs to the eye, 
follow all the common laws of dioptrics ; and there 
is no difference between the eye and an achroma- 
tic telefcppe, except that the former is a living in- 
ftrument, lufceptible of being moved in every di- 
rection, and of being lengthened or fhortened to 
change its focus. . 

At the moment when the impreiTion of the rays 
of light on the- rctjpa- begins to be felt, the eye 
can no longer be compared to an optical inftru- 
m.ent, It is not becaufe an image of the objed. is 



painted in miniature on this nervous membrane 
that wehaveafenfationofitjbutbecaufein painting 
itfelf there^ each luminous point produces an im- 
preffion of conta<51, which is communicated to the 
common centre of fenfations in a particular order, 
and with a degree of intenlity which varies ac- 
cording- to the form of the bodies and the reiiedl- 
ing property of their furface : in this refped: the 
exceffive fenfibility of the retina is inconceivable. 

The organ of fight feems to have a more ex- 
tenlive field of view in carnivorous birds than 
in man. 

104. The organ of hieafing confifts etientially 
of a nervous pulp, which perceives the conta61 of 
the air in a ftate of vibration. This pulp is found 
in the midft of a vifcous fluid, contained in the 
membranous labyrinth. 

The membranous labyrinth is enclofed in an 
ofleous labyrinth, formed in the petrous portion of 
the temporal bone. It communicates with the 
tympanum by two apertures, one of v/hich is 
clofed by a membrane, and the other by a fmall 
moveable bone. 

This fmall bone is articulated with three others, 

the laft of vyrhich is applied to the membrana tym- 

pani, and adheres to it. Thefe fmall bones have 

attached to them the mufcles by which they are 

2 D 2 moved; 


moved ; and they flretch the membranes to which 
they are affixed. 

The membrana tympani fcparates the tympa- 
num from the auditory conduit, which terminates 
in the exterior part of the ear. 

Ail this apparatus, which is very complex, feems 
deitined to facihtate the entrance of the vibrating 
air into the ear, as well as its contact with the 
nervous pulp of that organ, and of fecuring the 
1-atler from violent and abrupt impreflions. 
■ The impreffion made on the expanfion of the 
labyrintbic nerve, by the contaft of the air in a 
Hate of vibration, is continued to the brain, and 
produces in it the feniation of Ibund. 

The fenlibility of the nervous fyilem, which ap- 
preciates all the modifications of the air in a Itate 
of vibration, is no lets exquiiite than. that of the 
retina, which perceives refradled light ; and it is 
difficult to conceive how the ear can be fo delicate 
as to enable the mufician to diftinguifli feveral in- 
termediate degrees between two tones. 

105. The f}dlem of fmelling confifts in a mem- 
brane of a mucous nature, fiifceptible of being af- 
fected by the moleculas of certain bodies held in 
folution, or in fufpenlion in the air. 

The flrength of fmelling feems to be' in the 
ratio of the extent of the olfactory membrane: in 



Ibme'carhivofdus animals'this fenfe is exceedingly 

1 06. The organs of tafte are contained in a 
mucous membrane, which perceives the imprefJion 
produced on it by the contav51 of the moleculfe of 
certain bodies, and particularly of thofe which are 
foluble in water. 

The organ of tafte and that of fmell, in man, 
are far from perceiving the impreffion of all the 
molecule of bodies which come into conta£t with 
them : there are even many which have a very 
greaf a61ion on the nervous fyttem, and whofe 
contaft with thefe organs produces no fenfation. 
The moft violent poifons are frequently infipid ; 
and the air charged with miafmata, which produce 
epidemic dileafes, is often inodorous. 

The fyftems of the fenfes, of which we have 
here fpoken, are evidently organs of touching ; 
they however differ from that of touching, pro- 
perly fo called, in this ref[je<5l, that the latter re- 
ceives only the impreflion which refults from the 
refiftance, temperature, and form of the bodies ; 
while the former experience itnpreffions, which de- 
pend on other properties of thcfe bodies. 

All parts of the body arefufceptible of being af- 

fe^ed by the 'eohtaft of foreign fnbfiMnces, and 

tiiufl; be confidered-'as organs of touching; but 

' 3 D 3 that 

406 VITAL functions; 

that which fcems really to deferve this appellation 
is the hand, as its ftrufture allows it to accommo- 
date itfelf to the form of all bodies, and to exa- 
mine with eafe all their prominences. The Ikia 
of this part, by the continual exercife of touching, 
acquires a great aptitude for perceiving the llight- 
eft changes in the form, the contiftence, and the 
temperature of bodies. How far the delicacy of 
this organ can be carried, when not diftrafted by 
the fenfe of feeing, and when continually exer- 
cifed in a proper 'manner, may be obferved, in 
pfirticular, in fome blind perfons. 

As every part of the organization is fufceptible 
of being affe61,ed by the contadl: of foreign bodies, 
in this point of view they may all be confidered 
as organs of the fenfes. 

The difference which exifls between the various 
parts of the body, depends on the fundions which 
refult from their organic itrufture, and from the 
nature of the nerves diftributed to them ; according 
to thefe differences, the organs anfwer, different 
ways, to the impreffions made on them. 

When a change takes place in the Hate of an 
organ, in confequence of an impreffion received, 
this change is always manifefted in the particular 
exercife of the function of that organ, which may 
be increafed, diminiflied, or altered. 

Bodies which hffeh the afbion of an organ may 



be called deh'iiitants ; thofe which increafe it may 
be diftinguifhed by the appellation of excitants ; 
and thofe which alter it may be called irritants, 

107. The action of the numerous fubftances, 
fufceptible of affecting our different organs, pro- 
duces phoenomena exceedingly various. 

The impreflion may be confined to the part 
which is touched, or be propagated to thfe centre 
of the nervous action. If it be confined to the 
part touched, it produces only a very flight and 
tranfient change of ftate, which takes place, as we 
may fay, without the knowledge of the reft of the 
organizationi If it be tranfmitted to the centre 
of the nervous adion, the change of .fi:ate which 
thence refults may occafion a fudden fenfation, or 
produce none capable of being appreciated. 

In the laft place, the refult of an impreflion re- 
ceived by an organ may be fpecially manifefled, 
either in the part affe<Sed, or in a diftant organ, or 
in the whole of the organization. 

But to convey a better idea of thefe different 
modes of affection, we fhail here illufbrate them 
by examples. 

Slight local affedlions, altogether indolent^, and 
which feem to have a relation only to the part 
which exhibits them, often take place. 

Every ftrong and unufual ^impreflion on a part 
which receives nerves from the encephalon, or its 

2 D 4 vertebral 


vertebral prolongation^ gives rife to a fudden fen- 

But if the afFeclion takes place in an organ to 
which no nerves proceed from the encephalon or 
'its prolongation, the impreffion may ttill be re- 
ceived, and produce in the organization a change 
of (late, often very confiderable, without the indi- 
vidual experiericiri'g at firft any very fenfible fenfa- 
tion. Almoft all catarrhal difeafes begin in a fimi- 
lar manner; the a65:ion of the virus which produces 
gonorrhoea is not felt in the urethral membrane at 
the moment of infe6tion. Moft epidemic, conta- 
gious, and eruptive fevers^ and fev^eral kinds of 
afphyxiae, produced by the'adion of m.iafmata con- 
veyed into the aerian pafFages, belong to the fame 

An organ may be afFefted alfo by a body, Vvdth- 
out being diredly ilruck by it, in confequence of 
the communication ellablifhed between the nerves 
and every part of the organization : thus fridion 
with mercury excites fecretion of the falivary 
glands, without exercifing a perceptible action on 
the fkin. 

From thefe different confiderations it refults, 
that an orsan anfwers to different excitants, in the 
ratio of the fun61ion peculiar to it; of the nerves 
which are diftributcd thither, and of the nature of 
the excitants. 

¥/hea a mufcle is irritated, it anfwers by 



oiotion, as a gland does by the produdl of fecre- 

The ' fyliems of organs which receive nerves 
• from the eriG^phalon or from its rachidian prolon- 
gation, are eafily" excited, and experience a lively 
'and Hidden len'fation. Thofe which have thek 
nerves onlv from the ganglions of the trifplancb- 
nic are ienfible in a weak manner to the impref- 
lions received. 

When a f^ftem of organs, eafily excitable, is 
ftimulated in a manner proper to the exercife of 
that function, the refult is a fenfation of -eafci if 
the irritation is of fuch a nature as to diliurb the 
order of that fun'ftion, the fenfation is painful. 

Organs habituated to painful and agreeable fenfa- 
tionSj perceive alfo timple ones, which are, in fome 
tneafure, indifferent to the organic order. In a 
word, the uneafinefs experienced by organs wh-en 
their fun(5iions ftand in need of being exercifed, 
and that which refults from various internal de- 
rangements, are fo many particular fenfations. 

An organ reads with the more facility on an 
irritant, when it has already received the imprel- 
lion of it feveral times. Thus the mucous mem- 
brane of the aerian patTages is ealily affeflicd, when 
it has already experienced frequent colds. 

The cafe is the fame with the fyftems of the 
fenfes : the impreffion produced on them by ex- 
ternal obJQcis, is repeated with more facility, wdien 



they have already been fubjeffted to them feveral 
times. ^ 

Hence, the organs of the ienfes, the organs of 
motion, and thofe even of the different lecretions, 
acquire, by habitual exercife, a great aptitude for 
repeating, with facility, the acts peculiar to them, 
in confequence of the fame excitants. 

This force of habit, in regard to the repetition 
of the fame a6ls, becomes fo great that a d'lreB Jen- 
fatioiz, produced by an objed, may be entirely re- 
newed, without the prefence of the obje<5l by 
which it was originally communicated, but only 
by that of fome circumftances connected with it. 

The combination of dire£i fenfatians with recoi- 
led edfenfationSj or ideas, is at firll produced by 
the irrefiftible impulfe to a5i, in order to withdraw 
from pain, and to fatisfy wants. An aptitude for 
combination may then be extended to obje6ls lefs 
neceffary for prefervatiog. 

It is the extenfion of this power of combining 
fenfations, which gives rife to the development of 
the intellcGLual faculties. la a word, it is by the 
almoil exciufive employment of this faculty, that 
man attains to tliehigbefl degree of intelligence. 

The particular hiftory of the development and 
extenfion of the intellectual faculties muft be 
foil" 'el on phyfiological knowledge, which can 
alone afrbrd a rational balls and fixed point of de- 
parture to the metaphyfician. 

io8. The 


io8. The changes, which are continually ef- 
fefted in every part of the organization, conftitute 
nutrition, properly fo called. The blood furnifhes 
the materials neceflary to the exercife of this 

The bjood, during its continual circulation, is 
diftributed by the arteries to every part of the 
body ,- it then returns by the veins and lymphatic 
veffels, to repair its lofTes, to refume its former 
qualities, and ^o be fitted for a new circulation. 

The blood repairs its lolTes, at the expence of 
the prodiiiSl of digeftion : it frees itfelf from its 
excefs of aqueous parts by urinary excretion ; it 
refumes its former qualities by its pailages through 
fome glandulous organs, and particularly through 
the lungs. In the laft place, the elevated tem- 
perature of the lungs, which is the refult of the 
phaenomenon of nutrition, is maintained by means 
of the cutaneous organ. 

The blood, propelled from the left fide of the 
heart, iffues through the aorta, and ditlributes it- 
felf, by the arteries, to every part of the organiza- 
tion, to which it conveys the arterial blood, the 
common principle of all lecretion. 

The. blood, in tnis patTage, having experienced 
2ilofs and alteration, more or lefs confiderable, re- 
turns by the veins and the lymphatics. 

The chyle, which mixes itfelf with the venous 



blood, to rep^ii" its lofles, is the prod u 61 of di- 

Digeftlon comprehends the phienomena exhr- 
bited by the"a1im(irits introduced into the digefiive 
iyftem, from the time they enter the mouth till 
the period when they iffue from the body, at the 
extremity of the large inteftines. 

The alimen.tary fubtlances, which are always 
procured from animals or vegetables, are maltr- 
eated in the mouth and penetrated by the faliva. 
By degkition they are conveyed along the cBfopha- 
gus into the Itomach, where they are mixed with 
new juices, and by the action of the iiomack and 
their retidence in a living organ they are tranf- 
formed into a chymous pulp. The aliments then 
pafs into the duodenum, where they are penetrated 
by the bile, the pancrealic liquor, and the intefti- 
nal juice, and are transformed into a homogeneous 
fubflance, which contains the chyle. 

While this fubflance is proceeding along the 
intellines, the mouths of the numerous chyliferous 
veflels, with which their tides are covered, abforb 
the chyle it contains i and when it reaches the ex- 
tremity of the large inteftines, the reliduum of the 
digeftion is thrown out. 

The abforbent veflels of the chyle proceed, af- 
ter a fhort palTage, into the glands of the mefen- 
tery, where the chyle fiill experiences a particular 



change, and then ifTues from thefe glands by 
larger and lefs numerous veffels, whieh proceed 
in<o glands of a ftill greater fize. At length, 
thefe chyliferous veflels are confounded with the 
lymphatics, and terminate along with them in two 
thoracic du(Sls, which proceed into the fubclavi^ii 
veins: the left thoracic du^ is ' always much 
fironger than the right, which is fometimes want- 

Such are the pbaenomena of chylous abforption, 
perceptible by the fight ; but it is very probable, 
that thofe which efcape our researches are much 
more important and extenfive. 
. There are feveral reafons for believing that the 
whole proda6l of digell ion does not proceed into 
the fubciavian feins, but that a part is dire6ily 
mixed with the blood in fome other way. 

The transformation of the aliments into a ho- 
mogeneous pulp has at firft a refenjblance to a 
chemical operation : it however differs from it in 
many points of view. 

"When vegetable fubfiances, whether green, 
ripe, or already putrid, and animal fubilances, 
either raw, boiled, or even in an advanced ftate of 
putrefaction, are introduced into the ftomach, th^ 
action peculiar to them is immediately fufpended ; 
their fermentation or putrefaction is checked, and 
the vital power makes them pafs through a feries 
®f ph;£nomena, the refult of which is the forma- 


tion of a chymous pulp, that in the fame animal- 
always contains chyle of the fame nature. 

Dupiiiytren, in his ingenious experiments on 
the chyle, tried to communicate colour or fmell to 
this fluid, by mixing with the aliments colouring 
and odorous fubftances of every kindj mineral, ve- 
getable, and animal, but his attempts were fruitlefSj 
as he was never able to produce the leaft fenlible 

When the gaftric lyftem enjoys its full vital 
energy, none of the phtenomena peculiar to the 
fermentation and putrefa6lion of animal or vegeta* 
ble fubltances are obferved. 

But if this fyftem is gradually weakened, phse- 
nomena which evidently belong to the lavs of 
chemiftry are manifefled. There are then obferv- 
ed a difengagement of carbonic acid gas ; of 
falphurated and phofphorated hydrogen gas; of 
gafeous oxide of carbon, &c. ; the formation of 
acids and alkalies j and, during fome difeafes, the 
fmell of the faeces indicates a very evident com» 
mencement of putrefa6lion in the intefiiines. 

Digeftion is neceffarily a very important func- 
tion, (ince it comprehends the acftion of the mouth 
and of its glands, of the osfophagus, of the fto- 
mach, of all the intellines, of the liver, of the 
fpleen, and of the pancreas. All thefe organs ex- 
ercife an almoft limultaneous adiion, and with d 
great exertion of power^ Hence it happens that 



-people after meals experience To often drowfinefs 
and fatigue. 

Children, who in general are exceedingly vora-^ 
cious, lleep when their flomachs are full ; and it 
is obferved that great eaters generally take a nap 
after dinner. 

As digeftion affords a very lively mode of gra- 
tification, it was natural for men to make this 
fbnclion a fource of pleafure ; and it is indeed re- 
marked, that the table, among all nations, forms 
one of the greateil fources of enjoyment. 

It may here be obferved, that the whole of the 
organization, in the three orders of organs of 
which it is compofed, exhibits three very different 
fources of enjoyment. 

The firfl is found in the fyllem of the fenfes, in 
conjun6lion with the intellcdtual organ ; the fe-f 
cond in the digeftive organ ; and the third in the 
organ of generation. 

The firft order of organs do not become a 
fource of happinefs till the period of mature age; 
and only among civilized nations, who have given 
them a proper direction and cultivated the ufe of 

The lafl develops itfelf at the adult age, often 
with great force, and imperioufly requires to be 
exercifed ; but in old age, the action of the geni- 
tals becomes weakened^ and is often completely 

I The 


The digeflivc fyflcm affords pleafnrc at all sges: 
it is the only fource ofenjojinent in children^ who 
feera to live only to eat. In the adult age, the 
intelledlual funcSiions and thofeof the genitals im- 
perioLiIly require to be exercifedj ihe fun(?tion of 
thefe tyftems, which is then executed with great 
intenfit)^ renders that of the gadric fjiiem of little 
i-mpoi-tance ; but in the courfe of years the ftomach 
refumes the afcendancy, and it is the only enjoy- 
iTient of many oid perfons, who appear in various 
refpe6ls to return to the ftate of childhood, and 
to-acquire again its prevailing talles. 

The intelledual fim^lions are thofe^ in general^ 
vjfhieh continue longefl; they can retain their 
vigour and even acquire ftrength during the- 
whole courfe of life, when properly cultivated and 
in a continued raanner. 

If is however obferved that a derangennent of 
the princi'pal vital organs always produces a pro- 
portional weaknefs in the intelledlual funftions. 

The object of digeftion is to furnifh the quan- 
tity cf chyle, necelTary for repairing the lofles 
which the blood experiences in the courfe of its 
continual circulation, by fupplying materials for 
ditlerent fecretions. 

In perfons who lead a very active life thefe lofles 
are coniiderable : cutaneous and pulmonary per- 
fpiration, urine, and other excretions are always 
very abundant. Such perfons have an extra- 


Ortiinary appetite, and eat a great deal without 
being incommoded. 

On the other hand, there are found In large 
cities women of an indolent charadler, brought 
up amidft luxury and eafe, who have fcarcely any 
excretions. All their organs are reduced to a 
fiate of inadiion and debility, which feems to be a 
mean term between life and death. Thefe per- 
fons have habitually very little appetite, and ufe 
only a fmall quantity of food. 

The flomach, like the other parts, is ilrengtben- 
ed by exercife ; habitual excefs of aliments may 
caufe it to acquire great amplitude, and In this 
manner render it the predominant organ. It is 
not uncommon to meet with men who eat a great 
deal, though they take little exercife ; the greater 
part of the vital powers In fuch perfons are em- 
ployed in digeftion. Perfons, in general, who are 
exceedingly corpulent, are feldom endowed with 
great llrength of intelleft. 

When the ilomach is overcharged, it makes a 
continual effort to digeft the aliments which fur- 
nifh ufelefs chyle. If its weaknefs be fuch as to 
prevent it from efFe6ling digefiion, the alimentSj, 
being then abandoned to the laws of affinity, be- 
come to the alimentary canal a ftimulus, which 
excites vomitins: or diarrhoea with violent efforts 
and dreadful colic Sometimes they produce fpaf- 

voL. III. 2 E modic 


modic afFedions of different kinds, convulflons, 
and even death. 

Too frequent abufe of the gaftric organ and 
ina61ivity of the mufcular fyftem are the mofi: 
common caufes of the chronic difeafes which are 
obferved in large citie&. 

109. The blood is freed from its excels of 
aqueous parts and from different faline fubftances 
bj the urinary fyftem. 

The mod extraordinary phsenomenon which 
occurs in the function of the veins is, the promp- 
titude with which drink feems to be converted 
into urine, and particularly in man, who ufes a 
large quantity of it. 

The impoffibility of conceiving bow drink can 
be fo fpeedily converted into blood, and this blood 
into urine, has induced fome phyfiologifts to be- 
lieve that there muft be fome more dire6t way than 
circulation for transforming drink into urine ; 
but this hypothecs is not fupported by our anato- 
mical knowledge. 

The phenomenon of the fecretion of urine ap- 
pears extraordinary, merely becaufe it has not 
been confidered under its real point of view. 

The beverages which men ufe to excefs con- 
tain, in general, alcohol or acids. Thefe fub- 
ftances equally Simulate the (iomach and the 

kidneys ; 


kidneys ; and the limultaneous adlion of thefe 
two organs maintains the continual excretion of 

The ftomach, itimulated in a proper manner by 
the prefence of liquors, digells thefe fluids; and 
the aqueous part, taken up by the abforbing vef- 
fels, becomes fpeedily mixed with the blood. 

The kidneys, flimulated alfo by the aition of 
liquors on the nerves of the ftomach, foon enter 
into aftion, and the two large renal arteries do not 
fail, in a fhort time, to convey to them blood over- 
charged with aqueous parts. Thefe two circum- 
llances produce the fecretion of urine, which is 
effedled with activity, and the blood frees itfelf in 
the kidneys from the water which it receives in 
excefs from another quarter. 

It is here feen that the drink, in this manner, 
is not diret^ly transformed into blood, but that it 
becomes mixed with it in the flate of water, and 
that it is feparated from it by the continued and 
heightened adlion of the kidneys. 

Phylicians, therefore, have reafon for laying, 
that thofe who drink abundantly ibajh their blood; 
but it does not clearly appear what the blood can 
gain by being wajhed in this rhanner. 

Another very furpriling phenomenon exhibited 
by blood, is the promptitude with which it acquires 
certain odours, after a perfon has eaten or even 
infpired certain fubflances.' Every one knows that 

2 E 2- urine 


urine acquires a very fetid fmell after eating af- 
paragus, dnd that it finells of violets after fwallow- 
ing turpentine, or only infpiring the eflence of it 
for fome time. Thefe infiiances are commonly 
quoted, as a proof of the rapidity with which the 
aliments are transformed into blood ; but it is 
probable that thefe fubftances aft only as particu- 
lar itimulants of the kidneys, v.^hich produce a 
change in the mode of fecretion of thefe organs. 
This change is announced by a peculiar odour, 
which for the moft part is not that of the fub- 
ilance which produces it ; for the fmell of violets 
lias no relation to that of turpentine, 

no. From the different ads of life there refults 
a phaenomenon, which forms one of the principal 
cbara6lers of organized beings : namely, that of re- 
taining a temperature nearly conftant, whatever be 
the medium in which they live. 

In man this temporature is about 4a degrees 
of the centigrade thermometer (104° Fahren.) : it 
neceflariiy refults from the a6iion of the different 
lyftems of organs, and from the changes which 
are continually effe*51ed in all parts of the body. 
It may be obferved, that in the execution of thefe 
different phasnomena, the fubftances which iffiie 
from the body have more denfity than thofe which 
-enter it; fo that the refult muft neceffarily be the 
difengagement.of caloric; and it is to it, in all 
" ' - probabilityj 


probability, that the habitual elevation of the tem- 
perature is owing. 

Our aliments, indeed, confift of atmofpheric 
air, and animal or vegetable fubftances, wif.h which 
we, in general, unite a great quantity of water; 
whereas the materials which efcape from our 
bodies are, hardened excrements ; urine charged 
with faline matters; un6luous fweat; thick excre- 
tions, charged with albuminous, gelatinous, greafy, 
faline, Sec, fubftances ^ and in the laft place car- 
bonic acid gas. As all thefe produdts are evi- 
dently more confiftent than the materials which 
ferved to furnifh them, the tranfmutation of the 
latter, which is continually effedled in every part, 
of the organization, muft necefiarily be accom- 
panied with a difengagement of caloric. 

It is the air, in particular, digefted in the lungs, 
which is the fubft:ance moft proper for furnifhing 
caloric ; and it is indeed obferved, that the ca- 
loricity of animals is greater, according as the 
iyftem of refpiration is more extenlive, and as the 
exercife of that fan<5lion takes place with more 

In an individual who ufes violent and continued 
exercife, all the fecretions are accelerated, and the 
difeno;ao:ement of heat becomes conftderable. Per- 
fpiration, which is then proportioned to the quan-. 
tity of caloric difengaged, carries off the excefs of 
heat ; the temperature of the body is lowered, and 
2 £ 3 remains 


remains at the fame degree, by means of the cii- 
taneous organ, which thus becomes the regulator 
of caloricity. 

Whqji a man is expofed to a very high atmo- 
fpheric temperature, he feels himfelf oppreffedj 
he experiences a ftrong tendency to repofe ; has 
jio appetite, and is thus in a flate which difen- 
gages very little caloric. At the fame time the 
cutaneous organ, being ftrongly ftimulated by the 
external heat, excretes an abundant fweat, the 
evaporation of which, at the furface of the body, 
carries off a great quantity of caloric. 

In this ftate the want of alcoholic liquors, and 
of different ftimulants, is ftrongly experienced. 
It is almoft inconceivable what a degree of heat a- 
robuft man is capable of, fuftaining for fome time. 
But if the heat increafes or is maintained, he at 
length falls into a flate of oppreffion, which may 
become mortal. 

On the other hand, when a perfon is expofed to 
intenfe cold, he experiences an unealinefs which 
excites him to motion ; circulation and refpirafion 
are accelerated ; the air he infpires is more con- 
denfed ; perfpiration is almoft annihilated; the 
appetite is proportioned to the exercife, and all 
the means which produce heat are put into adlion 
to maintain the habitual temperature. The de- 
gree of cold which a man refifts with good clothes, 
exercife, and fpiritaous liquors^ is no lefs aftonifliing 



tlian the degree of heat he is able to endure. But, 
if he abandons himfelf to reft, the a61:ion of the 
cold provokes fleepj and if he fleeps, in this fitua- 
tion, he muft infallibly perifh. 

III. The florid, fpiimous, arterial blood, which 
is of a bright red colour, proceeds with rapidity to 
every part of the organization, by an order of vef- 
fels not very tortuous, the fides of which are ex- 
ceedingly thick. Thefe vefTels are divided and 
fubdivided in an indefinite manner, and lofe them- 
felves in very minute ramufculi. As they divide, 
their refpeiftive capacity is increafed, and the blood 
circulates with lefs adivity in the rami than in the 

The blood acquires and retains a temperature 
of 40 degrees of the centigrade thermometer*, by 
the refult of the different fecretions, the materials 
of which it furnifhes: it frees itfelf from the heat 
which exceeds this temperature, by means of per- 
fpiration ; and from its excefs of aqueous parts by 
urinary fecretion. 

The blood, in diilributing itfelf to all parts of 
the organization, to fupply them with the materials 

*The tranflator muft here obferve, that the author in different 
parts of this work makes the heat of the blood to be 40 degrees 
of the centigrade thermoaleter, or (04° of Fahrenheit, which is 
7 degrees more than it is commonly-fuppofed to 'be) as mod 
writers on phyfiology eftlmate this heat at 97 degrees of Fah- 

2 E 4 neceffary 


neceffary foreffe^^ling the different changes which 
are there continually tiiking place, undergoes a 
very manifcft alteration. It then returns from ^he 
different parts by two orders of veffels, the veins 
and the lymphatics. The veins convey back the 
greater part of the blood, that which has under- 
gone the lead alteration, and which ftill retains a 
brownifh red colour. The lymphatics collect the 
refiduums of the different fecretions, and in gene- 
ral all the fluids difFufed throughout the lar^e ca- 
vities, or depofited in the cells of the different 

The venous blood and the lymph proceed, flowly 
in tortuous veflels, the thin lines of which are 
furnifhed internally with valvular folds, which 
prevent the return of the fluids. Thefe veffels 
arife in imperceptible capillary ramufcuh, and 
their fucceffive union forms rami, branches, and 
trunks. Thefe vefTcls, in uniting, decreafe in re- 
gard to their rcfpedtive capacity, and the fluids 
they contain accelerate their progrefs as they ad- 
vance from the rami into the branches. In the 
laft place, the lymph receives the produ6l of di- 
geftion, and mixes with the venous biood ; and 
the latter, after pafling through feveral organs, re- 
turns to the point fronri which it proceeded, in the 
flate of arterial blood. 

The lymphatics, in their pailage, traverfe the 
j^umerous glands, in which the lymph experiences; 

ji repeate4 


a repeated affimilation, or fort of digct1:ion, which 
gives to this tiuid chara6lers of vitality, and ren- 
ders it proper for forming a part of the blood. It 
is not until they have been thus properly affimi- 
lated in the glandulous organs, that the fluids 
abf^rbed by the lymphatics pafs into circulation. 
By this dilpofition the blood can receive none of 
thofe foreign fubflances which it is vulgarly be- 
lieved can pafs into it with lb much facility, in' 
order to infeft sts whole mafs. 

The venous blood, which returns from the dif- 
ferent parts of the abdomen, feems more particu- 
larly to be charged with heterogenous fubftances. 
The veins which bring it back unite into a large 
trunk which proceeds into the liver. This blood, 
in traverfing the hepatic organ, frees it felf from 
the adipofe and albuminous fabftances which it 
contains in excefs ; thefe fubftances, united to a 
fmail quantity of foda, form in the bile a fapona- 
ceous liquor, the excretion of which by the duo- 
denum becomes one of the moft powerful agents 
of digeftion. 

The veins of all the parts unite into two large 
trunks, which convey the blood to the right fide 
of the heart, from which it pafles into the pul- 
monary organ. 

Jt is in pafling through this organ, in parti- 
cular, during the a6l of refpiration, that the blood 
experience? the moft remarkable changes, and 



completely refumes all its qualities of arterial 

By the indefinite expanfion of the pulmonary 
arteries, the blood is uniformly diffufed throughout 
every part of the refpiratory organ, where it finds 
itfelf, as we may fay, in immediate contacl with 
atmofpheric air, introduced into the bronchial cells, 
by paffing through the aerian canals, the fubdivi- 
iions of which feem to equal thofe of the arteries. 

During the adt of refpiration, the blood affumes 
a beautiful fcarlet colour,, and becomes fpumous, 
warmer and lighter than the venous blood ; the 
atmofpheric air lofes a part of its oxygeuj perhaps 
even a little azot, and becomes charged with nearly 
the fame quantity of carbonic acid gas. 

In the fun(5lion of the refpiratory organ, it is 
probable that the part of atmofpheric air which is 
wanting, has been digefted and abforbed in order 
to fcrve for the general nutrition, and that the car- 
bonic acid gas is the produd of the particular 
fecretion which the blood efFe6ls in the lungs, 
as the bile refults from that efFeded in the 

In a word, the fides of the bronchial cavities 
fecrete an abundant ferofity, which is continually 
evaporating by expiration, and which becomes 
one of the grand caufes of lofs. 

1X2. The air expelled from the lungs becomes 
I , ilill 


fiill ufeful to the organization : this elaftic fluid, 
driven oat with greater or lefs force, may give rife 
to the formation of found. 

The lungs, which continually receive and ex- 
pel air, are proper for producing noife. Cries are 
the firft language of pain in all the mammalia ; 
and they afterwards become that iof joy and of 
€?ery other fenfation. 

Air put into a ftate of vibration, in its pailage 
through the glottis, produces found by means of 
the epiglottis, which ads the part of a pipe. 

The fundamental found is furnifhed by the 
larynx, the fhortening of which gives the odlaves, 
and the con trad ion the harmonics. 

The varied articulations of fpeech are produced 
by the different parts of the mouth. 

But thefe data are far from accounting for the 
effeds of finging and of fpeech. It may be faid 
tlTat the ae'rian paflages forni a very bad wind 
inftrument, which man has found means to turn 
to great advantage. 

It mufl not be believed that fpeech, like an ear, 
is the gift of nature: voice and fpeech are the refult 
of overcoming a great difficulty ; and to this ob- 
jecl the progrefs of civilization has contributed. 

The children in civilized nations learn to fpeak 
with facility, becaufe they inherit a fort of pecu- 
liar difpolition for learning the language of their 
fathers ; becaufe all thofe around them fpeak and 



employ every method proper for making them ac- 
centuate ; and becaiife the firft years of life are 
entirely devoted to that exercife. 

But the ufe of fpeech is fo difficult to be ac- 
quired, that it is fcarcely poffible to teach it to a 
child who has palled the firft fifteen years of life 
without hearing others fpeak. 

Singing, perhaps, is attended with lefs diffi* 
culty in the execution than fpeech ; and if all the 
means employed to teach articulation vi^ere em- 
ployed to teach modulation to the children of 
good fingers, there can be no doubt that mufic 
would become an art familiar to almoft every in- 

113. The reproduction of the human fpecies 
feemstobe efi^e(51ed in a manner analogous to that 
of all other organized beings. An egg, which 
confifts of its germ and placenta, acquires in the 
ovarium a certain increafe, beyond which it does 
not proceed, until by the contaft of the fecun- . 
dating fubftance it has received the impulfe of a 
new life. 

At this period it increafes, detaches itfelf from 
the ovarium, traverfes the uterine tube, and fixes 
itlelf in the uterus, where it remains nine months. 
During this time the placenta, which is attached 
to a part of the fides of the uterus, extrads from 
it juices, which it ailimilatcs^ and which ferve for 



its increafe, as well as for that of the germ, by 
means of the circulation eftablifhed between thefe 
two parts. 

When the foetus has acquired a certain growth, 
and the placenta has attained to a certain degree 
of maturity, both are expelled from the uterus by 
the contraftile action of its fides. The child 
then enjoys a new life, and ftill remains attached 
to the mother, for fome time, by the need of 

The fyflem of generation feems to be indif- 
ferent to and little connedled with the whole of 
the individual organization : during the firft years 
of life it has no influence ; it lofes its a6tion at 
an advanced period, and may be fuppreiled with- 
out great inconvenience : however, when its func- 
tion is exercifed with great energy, it borrows 
aid from all the other fyftems of organs, which 
are entirely fubordinate to it ; and each concurs, 
in its own manner, to favour its acS^ion. 

The danger of employing this organ has been 
too much exaggerated j like all the others, it is 
lirengthened and maintained by moderate exer- 
cife ; it is deftroyed by long inadlivity ; and yet 
it may, with truth, be faid, that by excellive ufe 
it is deftroyed much fooner than any other organ. 
This function, highly important, fince it perpe- 
tuates the fpecies, is one the ufe of which is ex- 
cited by the mofl exquifite pleafure. 



The exercife of this fundion ptocures a fenfa- 
tion the more lively, as its duration is fhort : it 
can therefore ferve only for employing a very 
fmall portion of time. Among idle perfons, who 
have acquired a habit and contra61ed a need of 
this enjoyment, it is foon deftroyed by abufe ; 
and the deiireof renewing a pleafure, which they 
can no longer difpenfe with, leads to the mod ex- 
traordinary expedients ; and moft inconceivable 
extravagances, the refult of an exalted imagi- 
nation, which varies all its refources, and tries 
every mean proper for renewing a fenfation, be- 
come neceflary, and for which the organ is more 
or lefs completely unfit. 

A great many lingular things have been faid 
to explain thefe flights of the imagination, which 
have been conlidered as peculiar tafles, natural 
to fome individuals ; but they are merely the re- 
fult of an ever-a6tive deiire to reproduce fenfa- 
tions, which have become wants. 

At the period of puberty, in perfons of a ftrong 
conftiiution, who live in towns amidft eafe and 
idlehefs, furrounded by objects which excite amo- 
rous defires, the organ of reproduftion imperioufly 
requires to be employed, and if completely prevent* 
ed very ferious accidents may be theconfequencei 

No liate, perhaps, is more painful, and no fitu-^ 
ation is worfe underftood, than that of a perfon. 
who is continually employed- with a want which 



he endeavours to reprefs. This condu6l main- 
tains a fort of perpetual irritation in the genital 
parts, which, in the end, generally produces very 
fevere chronic affe6lions, and particularly among 
the vt'omen. 

The only rational and fure means of extiUf- 
guifbing the action of this organ is, to give great 
exercife to the reft, but efpecially to the mufcular 
fyftem and the intellecfluai faculties, vi^hich always 
occalions a falutary diveriion, arxi affords great 
employment to the vital powers. 

The moft important confideration, fuggetted 
by the fyftem of reprodudlion, is that which re- 
lates to the means it affbrds of tranfmitting to 
children the general, and even the particular 
difpofitions of the parents. This faculty leems 
to belong to all organized beings ; and is obferved 
in plants as well as in animals. 

Experience has proved that there is no altera- 
tion or affedtion, no phyfical difpolition or apti-^ 
tude for certain intellectual qualities, which are 
not more or lefs fufceptible of being tranfmitted 
by generation. 

Reproduction, exhibits alfo one of the grand 
means of the improvement as well as of the 
deterioration of the human race. In this refpedt, 
it muft always be recomembered that children, 
caeteris paribus, have a greater refemb'ance to 
their mother, in the eftcntial -^nd fundamental^ 



interior parts, and to the father in regard to the 
acceflbry or fuperficial parts. 

1 14. Life and health are the eflential refult of a 
proper adlion of the different funftions. Under 
this point of view, it is proved by experience and 
obfervation that the organs are ftrengthened by 
moderate and habitual exercife ; that they are 
weakened by repofe or forced exercife ; and that 
the weaknefs or derangement of a fundlion has 
always a greater or lefs influence on the whole of 
the organization. 

From our knowledge acquired in regard to the 
organic ftru6iure it refults, that the bell com- 
bination of the powers for rendering the organi- 
zation mofl conducive to the happinefs of the 
individual, and to the progrefs of civilization, is 
when children receive an education founded on 
a proper development of the phyfical and intel- 
lectual faculties, and the ftudy of the exa(9: fci- 
ences, and when they purfue the fameobjedl du- 
ring the remainder of their lives, by diredling 
their attention to one part of fcience or of art, 
which they endeavour to improve. . ^ 


[ 433 ] 


115. Man enjoys a certain number of facul- 
ties, the combined employment of which render 
him fufceptible of indefinite improvement. 

ill. He is provided with organs of loco-motion, 
nutrition, and reprodu6lion. 

2d. He is in relation with external objeifts by 
means of the organs of the fenfes. 

3d. He is excited to adt and to exercife his 
different functions by the flimulas of pain; and 
induced to fatisfy his Vv^ants by the defire of ob- 
taining eafe. 

4th. The fenfations he experiences may be re- 
newed, without the prefence of the objedts which 
at firft produced them, but merely by that of ob- 
jects which were connected with the firfi:, and 
which recall them. 

5th. The organs are flrengthened by exercife, 
and by repeated adlion acquire a great tendency 
to habit. 

6th. The peculiar difpofitions of the organiza- 
tion are tranfmitted by generation. 

In the exercife of his faculties, it is obferved, 
that man is irrefiflibly excited to aB^ for the fake 
of his own prefervation, and for the propagation 

v®L. III. 2 ? of 


of his fpecies ; that he continually experiences 
direct fenfations, which recall others, and that he 
is forced to combine dire6l fenfations with recalled 
fenfat'wns, to deduce from them refults favourable 
to his prefervation. 

The faculty of aB'ing and comlnn'mg, for his 
prefervation, may have been afterwards extended 
to the fadlitious wants which were fncceffively 

This faculty agqoires great extent among men 
who unite together in fociety. Daring the flow 
progrefs of civilization, they are gradually feen to 
increafe their means of exigence and of happinefs. 
They fubflitute artificial for natural figns ; they 
employ their cries as figns, and gradually tranf- 
form them into language. By little and little 
they acquire the habit of more continued atten- 

The continual employment of fa6iitious figns 
gives great extent to the faculty of having re- 
called fenfatiuns. Through the neceffity of pro- 
viding for urgent wants, and fatisfying ardent 
dcfires, man foon forms combinations, more or lefs 
extenfive, of the fenfations v^'hich he experiences. 
The propenfity to rule is gradually changed into 
a defire of. obtaining refped:. In a word, among 
men in a fiate of civilization, who find them- 
felves without employment, amidft all the means 
of exiitence, this defire of refpedf, and the necef- 

3 ^ fity 


iity of obtaining new fenfations, which always be- 
comes flronger, makes all the faculties acquire an 
extenlion, which increafes as the produ6l of their 

Under thefe favourable circumftances, man be- 
comes a being who has no refemblance to his ori- 
ginal type : the point from which he fet out can 
no longer be difcovered ; the path which he has 
purfaed can fcarcely be traced out ; and his new 
moral exiftence feems to be .^Uoo-pther divine. 


. K. WilXs, rriiiter, Chaiitciy-lane» 


Vol. I. page 373, line 10 from the bottom, for tracheal nrtert/t 
read trachea. 

Vol. II. page 147, line 5 from the bottom, after the word suc- 
cessful, add hooping cough. 

page 291, line 8 from the top, for synoche, read 

page 398, last line, for obsfipite, read obstipitas. 

page 206, line 2 from the bottom, for mammill'*, read 
breasts ; and, 

page 207* line 4 from the top, for mammilla, read breast.