Vegetable and animal foods alike are, then, capable of solution by the gastric fluid, provided that their "organization or vital principle be previously destroyed." One could thus believe the further evidence that "a respectable gentleman" had seen two polar bears "that had subsisted on vegetable food alone, from the time that they were taken from their mother's breasts; and that they were more than half grown, and very fat." On the other hand, he cites the case of the Italian naturalist who "by dint of hunger learnt a pigeon to eat meat of which it became so excessively fond, that it preferred it to every other kind of food, even to wheat, which in their natural state, they eat before anything else."
Will simple solution by the powerful action of the gastric fluid explain the conversion of "aliment into chyle?" asks Dr. Young. Many earlier teachers had assumed that activities which we now know to be associated with microorganisms play a part. The warmth and moisture of the body would facilitate this fermentation and putrefaction. Our author writes:
In order to ascertain whether a vinous fermentation could take place in the human stomach the following experiment was performed. My friend, Mr. Mitchell, avoided his usual breakfast, in the place of which he took, between the hours of eight and ten, twelve ounces of sugar. Nothing more was taken until one o'clock. Having the power to ruminate, it was at this hour thrown up; the mass was sweet: upon being put to rest no intestine motion or disengagement of air was to be perceived. It was then submitted to distillation: a limpid fluid passed over into the receiver, which was sweetish, but had none of the properties of a vinous spirit. Carbonic acid gas is constantly evolved during the vinous fermentation; Mr. Mitchell, therefore, paid particular attention to this, as long as the sugar was on his stomach; but there was not the least eructation of air during the whole period the experiment was going on. If ever a vinous fermentation took place in the stomach, we expected to have found it in this experiment; as this viscus was plentifully supplied with saccharine matter, which passes so readily to this state; but as nothing of the kind occurred, we conclude the vinous fermentation has nothing to do with the digestive process.