stood how, \frhen the stomach is empty, little biood enters into it, in that 

 state of contraction ; how at the same time, the spleen which is less com- 

 pressed, and the liver, must receive a larger supply of blood, and again a 

 smaller quantity, when the stomach is full. 



The gastric juice, the result of arterial exhalation, mixes with the mu- 

 cus poured out by the mucous follicles of the internal membrane of the 

 stomach. This mixture renders it viscous and ropy, like the saliva, to 

 which, in man, the gastric juice bears a-great analogy. It is very difficult 

 to obtain it pure, so as to analyze it, and even if by long fasting, the sto- 

 mach should be deprived of the alimentary residue, which might affect its 

 purity, (5ne could not prevent its being mixed with a certain quantity of 

 liquid bile, which always flows back through the pyloric orifice, turns 

 yellow the inner surface of the stomach, in the neighbourhood of that 

 orifice, and even imparts a certain degree of bitterness to the gastric 

 juice. The passage of the bile from the duodenum into the stomach, can- 

 not be looked upon as morbid; it occurs in the most perfect health, 

 which has led to a well founded opinion, that a small quantity of the bili- 

 ary fluid is a useful stimulus to the stomach. This opinion is confirmed 

 by an observation of Vesalius, who relates, that he found the ductus 

 communis choledochus, opening into the stomach, in the body of a con- 

 vict noted for his voracious appetite. It is further confirmed by what is. 

 observed in birds of prey, in the pike, Sec. who digest easily and with 

 great rapidity, because the termination into the duodenum of the ductus 

 communis choledochus, being very near to the pylorus, the biie easily 

 ascends into the stomach, and is always found there in considerable 

 quantity. 



To obtain some of this gastric juice, it is necessary, either to open a 

 living animal under the influence of hunger, or to oblige a night bird of 

 prey, as an owl, to swallow small spunges fastened to a long thrend. 

 When the spunge has remained for a s >ort time in the stomach, it is 

 withdrawn soaked with gastric juice, of which the secretion has been pro- 

 moted by its presence in the stomach. 



The gastric juice, in its natural state, is neither acid nor alkaline : it 

 does not turn red or green, vegetable blue colours*. Its most remarka- 

 ble quality is, its singularly powerful solvent faculty, the hardest bones 

 cannot withstand its action; it acts on those on which the dog feeds; it 

 combines with all their organized and gelatinous parts, reduced them to 

 a calcareous residue, forming those excrementitious substances so ab- 

 surdly called album graseujn, by the older chemists. The solvent energy 

 of the gastric juice, is in inverse ratio of the muscular strength of the 



* There is some difference of opinion on this point. Carminati declares that in car- 

 nivorous animals the gastric fluid is add, that in phytivorous it is alkaline, and that in 

 those which live indiscriminately on animal and vegetable food, it is neither acid nor 

 alkaline. By BrugnatelU it is said that, in all animals, it is uniformly acid. That the 

 gastric hquor is occasionally acid in the human species, cannot be denied. It has in- 

 deed been found so both by Reaumur and Hunter, and in subjects where there was no 

 reason to presume it had become vitiated by a disordered condition of the stomach. 



We are inclined to believe that the gastric fluid has pretty nearly the same proper- 

 ties in all animals. In support of this conclusion we may appeal to" the fact which has 

 been verified by repeated experiments, that both carnivorous and phytivorous animals 

 digest and thrive well on an exchange of food, the one being- made to feed exclusively 

 on vegetable, and the other on animal matter. Vide Experiments of J. Hunter and 

 Spallanzam. Chapman. 



