GASTRIC Juice, a thin pellucid liquor, which distills from certain glands in the stomach, for the digestion, &c. of the food.
From some late experiments it appears, that this juice is the chief instrument of digestion; but in what manner this operation is performed by it, remains yet a secret. It is not possessed of any corrosive acrimony, for this would act upon all substances indiscriminately; but the gastric juice is found to act only upon particular substances. The most remarkable particularity of this kind is, that though it very readily dissolves animal substances when deprived of the vital principle, it absolutely refuses to touch those which are alive. This would seem to favour the opinion formerly in vogue, that digestion was performed by means of a kind of fermentation induced into the substances swallowed for food; as very probably the parts of living animals may be capable of resisting those fermentations which readily take place in dead ones. But whether or not this is the case, must be determined by future experiments.