Farinaceous food, such as rice, sago, arrow-root or gruel, is also rapidly assimilated, and proves less stimulating to the system than concentrated animal food; but as it affords no scope for the due action of the muscular coat of the stomach, its exclusive use for any length of time seldom fails to weaken that organ and impair digestion. For the same reason, however, it becomes a very appropriate aliment, where stomachic irritation already exists. When the stomach is in a healthy state, milk is digested almost as easily as farinaceous food and is equally unstimulating. The other kinds of vegetable substance are the slowest of all in undergoing digestion, and very frequently pass out of the stomach and through the bowels comparatively little changed; and hence the uneasiness which their presence so often excites in the intestinal canal, especially in persons of weak digestion, owing to the nerves of the intestines having a relation to _chyme_ or _digested_ food, and not to substances which resist the action of the gastric juice. In a given bulk they contain less nutriment, and excite the system less, than any other kind of food; so that they are well adapted for the diet of those in whom it is necessary to avoid every kind of stimulus, and who are not subjected to great muscular exertion; but to a person undergoing hard labour, they afford inadequate support. Liquids--soup, for example--do not call into play the muscular coat of the stomach, and are so slow of digestion where that organ is already weakened, that they often give rise to acidity; and hence they are unfit for most dyspeptic patients. Before the gastric juice can act upon them, the fluid part must be absorbed, and the mass thickened to a proper consistence for undergoing the usual _churning_ motion. On examining the contents of the stomach an hour after St Martin had dined on beef-soup, Dr Beaumont found that on one occasion the absorption of the watery part had been carried so far as to leave the remainder of even a thicker consistence than after an ordinary solid meal, but a similar result follows only when the digestive powers are very vigorous. When drink is swallowed, it also is carried off by absorption, and is not digested or allowed to pass through the pylorus. One purpose of this provision seems to be to prevent the gastric juice from being rendered inefficient by too much dilution.