DIGEST 
ee and produccs flatulence, acid eruGtations, &c, which 
re well-xnown fymptoms of indige Thefe fa&s, 
y all thofe at leaft who have che the trouble to examine 
ne ee 
With as little reafon has digeftion been confidered a {pecies 
of putrefadion, or fpontaneous change of imal and ve- 
Saar ood. Not to mention that dizeition never exhibit 
e of ammoniacal produéts, wien a) are the m 
hokiv, g Cae of putrefaétion, we fhali find 
th 
organs have the power of reltoring utrid meats to a fou 
ftate, or at lealt of arrefting the putrefaGion of fubftances 
{ubmitred to_ heir aétion Se me are enabled, by the 
than chem lve 
thefe; and, eee ae pees that p 
which is fubmitted to the aGion of the # ace is perfectly 
{weet, and in _a more of lefs advanced ftate of diffolution, 
M 
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os 
s 
OQ 
oo 
o 
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“t 
fa 
a 
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law) 
Mo a 
rat nes and other phy folegifs, have cand that sida 
taken accidentally, or given purpofely to — 
lott i een cence in the ftomach, previoufly to i 
geftion. 
Fermentation was the fyftem of the chemifts; trituration 
was that of the mathematical phy fiologifts ; who co ompared 
the changes effe&ted on a fubftance in a mortar by the peftle 
of the apothecary, to thofe a ee food undergoes in the 
ftomach. But what analogy co er have been conceived 
to exilt between the forcible attrition a a fub 
of the ttomach? ‘Th en held no longer, ¢ 
when it was perceived that chyme differed entirely from t 
food had been ns; that is to fay, th the fam 
that H 
food were triturated mechanically out of the body, and re- 
duced to pap of precifely the fame eonfiftence with chyme, 
it would not poffefs the fame properties with chyme. For, 
whenever this fact was known, it it mult be evident that the 
food had undergone changes in its compofition. The fa& 
that various fruits, as grapes, currants, ratfins, &c. which are 
eation, an 
ai 
re omach, s that food can €x 
perience only a very fight comprefling force in its paflage 
Bu i xperiments of y Reaumur, and 
Spallanzani, demontlrated that chyme is not owing to tritu- 
ration ; for, on enclofing different ct of food in metallic 
tubes and balls be: of holes, in fuch a manner as to fcreen 
them from the anical re of ne fiomach, they found 
thac thefe fubitavee, after having remained a fuffici ent time 
in the , Were CO averted into chyme, juft asif they had 
not been aed fuch 
de in which digeltion i is effected in the gizzard of 
the gallinaceous birds, is the moft plaufible argument in favour 
uration. In them the food, after being macerated in 
dcfcends into the gizzard, whofe vaft mufcular 
of mattica- 
“we 
uly furprifin 3 of glafs or cryftal 
are as ee cal or metallic ube are flattened, &c.. 
ION, 
Thefe effeAs are sr eae ky thofe of maftication in the 
human fubje&; an e digeftion is completed by- 
means of a fluid ae in an glands at the termination 
of the celophagus. ‘The wide difference of ftruture between: 
thefe gizzards and the human ftomach fhould have fhewn. 
the abfurdity of applying inferences drawn from what happens 
in the one, to the other. 
Pitcarne aan the povrer af the flomach as equal to 
12,95 tlbs.; and abdominal mufcks, 
whi ch conor ae aa. in He alc ternate motions of re-- 
351be. 
we bee! rh 
only erved to‘e 
force with which that organ ads on its contents does not. 
exceed a few ounces. 
The learned and laborious Haller fuppofed that the food’ 
was merely diluted and foftened by the galtric juice; he 
conceived that this maceration was favoured and accelerated “ 
y the warmth of the part encement of putre- 
fa€tion, and by the gentle, but continual motions, by whicl 
the aliment is § agitate ted. ac nfurmounts at length the 
ohefi ° u 
ftomach, or paunch, where it is truly macerated, and perhaps 
undergoes incipient fermentation. It is brought back from 
chewed, after which it 
Oo 
otally di t of the human fubje e may 
jal onl uk jabs any analogy between cite two 
"The formation of chyme, then, is owing to fome oa 
procefs taking place in the ftcmach ; and it has been con- 
cluded from the experiments of Stevens, Reaumur, Spallan- 
zani, Scopoli, Brugnateili, Carminati, and others, ak its: 
formation is brought about by the ation of a particular 
liquid fecreted by the ftomach, and for that reafon pei 
gafiric jui 
No erhaps receives a greater number of veffels, in- 
proportion i ulk, than the ftomach; end 
conclude, that this large fupply is not ad defigned for 
rnifh the materials 
of fome fecretion. The fluid thus force is the gaftric juice, 
which is probably poured out mcft abundantly when the 
prefence of tood in the ftomach irritates that organ, and in- 
vites an afflux of blood from its numerous arterial tubes. It 
feems to be produced dire&ly from the exhaling arteries, 
without any intermediate {ecretory apparatus. 
portion of bile, which, entering at the erie tinges the 
internal coat near that Openings aod imparts a certain bitter- 
nefs to the juices os the 
Dr. Thomion, in his fy ftem of chemiftry, Eanes to Place 
