94 



parietes of the stomach, and in those animals in which the parietes of 

 that viscus arc very thin, and almost entirely membranous, it has most 

 power and activity. In the numerous class of zoophytes, it alone suffices 

 to effect decomposition of the food, always more prompt, when accom- 

 panied by warmth of the atmosphere, as \vas observed by du Trembly, in 

 the polypi, which in summer, dissolve in twelve hours, what in colder 

 weather it would take three days to digest. In the actinia, in the holo- 

 thuda, the gastric juice destroys even the shells of the muscles which 

 they swallow. Are we not all acquainted with the peculiar flavour of 

 oysters, how much they tend to whet the appetite ? this sensation de- 

 pends less on the salt water contained in the shell, than on the' gastric 

 juice which acts on the tongue, which softens its tissue, and quickens its 

 sensibility*. This mucous substance, when received into the stomach, 

 promotes the digestion of the food which is afterwards taken into it, for 

 the oyster itself is very little nutritious, and is used rather as a condi- 

 ment, than as affording nourishment. 



The gastric juice not only pervades and dissolves the food received in- 

 to the stomach, but it unites and intimately combines with it, completely 

 alters its nature, and changes its composition. The gastric juice acts, in 

 a manner peculiar to itself, on the food exposed to its action, and far from 

 inducing a beginning of putrefaction, suspends on the contrary, and cor- 

 rects putrescency. This antiseptic quality of the gastric juice, suggest- 

 ed the practice of moistening ulcers with it to accelerate their cure, and 

 the experiments made at Geneva and in Italy, have, it is said, been fully 

 successful. I have made similar experiments with saliva, which, there 

 is every reason to consider, is very similar to the gastric juice, and I have 

 seen old and foul ulcers assume a better appearance, the granulations be- 

 come healthy, and the affection rapidly advance towards a cure, from the 

 use of that irritating fluid. I had under my care an obstinate sore on the 

 inner ankle of the left leg of an adult; notwithstanding the external ap- 

 plication of powdered bark, and of compresses soaked in the most deter- 

 gent fluids, this sore was improving very slowly, when I bethought my- 

 self of moistening it every morning with my saliva, the secretion of which 

 was increased by the hideous aspect of the sore. From that time, the 

 patient evidently mended, and his wound contracting daily, at last became 

 completely cicatrized. 



However powerful the efficacy of the gastric juice, to dissolve the ali- 

 mentary substances, it does not direct against the coats of the stomach 

 its active solvent faculty. These parietes endowed with life, powerfully 

 resist solution. The lumbrici so tender and delicate, for the same rea- 

 son, can exist within it, without being in the least affected by it, and such 

 is this power of vital resistance, that the polypus rejects unhurt its arms, 

 when it happens to swallow them among its foodf. But when the stomach 

 and the other organs have lost their vitality, its parietes yield to the sol- 

 vent power of the juices which it may contain, they become softened, and 



* The whole of this sentence, and the subsequent one, is inapplicable. When we 

 swallow raw oysters, we do not wait for them to soften tlie tongue , and in this country, 

 at least, daily experience teaches that they are extremely nutritious. Godman. 



j- It had been thought, that no animal could live on the flesh of his own kind, and 

 this circumstance was explained on the same principle ; but to refute it, we need only 

 quote the instance of cannibals, and of several tribes of carniverous animals, who, in the 

 absence of other prey, devour one another. Author's Note. 



