Copy 1, Volume 1

The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good].

  • Good, John Mason, 1764-1827
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good]. Source: Wellcome Collection.

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    in fact, in the whole division of the vulva; and who, to the age of fourteen, had regularly discharged her urine by the breasts, and her feces by a natural vomiting or rejection from the stomach. * Generally speaking, the extent of the digestive cavity bears a relation to the nature of the aliments by which the individual is designed to be nourished. The less analogous these aliments are to the substance of the animal they are to recruit, the longer they must remain in the body, to undergo the changes that are to assimilate them. Hence, the intestinal tube of herbivorous animals is for the most part (for we still meet with exceptions) very long ; or, in particular portions, exceedingly capacious; in various kinds remarkably complicated, and often double or triple. Thus, in the horse, the large-intestines are of enormous size, and dilated into sacculi, while the coecum is as capacious as the stomach. In the ruminant animals, besides the peculiar complexity of the stomach, the alimentary canal is twenty-seven times the length of the body. On the contrary, carnivorous animals have a short and straight canal; their food being already of their own nature, containing a larger quantity of nourishment in less bulk, and hence demanding a smaller proportion of time and space to become fit for use. [In them every circumstance concurs to accelerate the passage of the alimentary matter. It undergoes no mastication; it is retained but a short time in the stomach; the intestine has no folds, nor valves; its diameter is small; and the whole canal, when compared to the body, is extremely short, being only as three or five to one. Whales, however, have a longer canal, than other carnivorous mammalia, their stomach is complicated, and the. intestine has longitudinal folds. Indeed, carnivorous mammalia, of aquatic habits, generally possess a considerable length of intestine; a point, in which they differ from most other animals of that class. The shortness of the intestinal canal in the generality of fishes, is compensated by the length of time the food, which is usually animal, is detained in it. A perch has been observed to take food but once in ten days, or a fortnight.+ In omnivorous animals, the canal is not so long as it is in the herbivorous, nor so short as it is in the carnivorous. Thus, in the rat, its proportion to the body is as eight to one; in the pig, thirteen to one; and in man, six or seven to one. In him the diminution in length is compensated by the numerous valvulze conniventes and the preparation of the food by cookery.{ The domestic cat, which eats bread as well as’ flesh, has an alimentary canal considerably longer, than that of the wild cat.] The digestive canal of man is less capacious and complex, than that of most mammalia, which take only vegetable food ; yet, larger and more complicated, than that of other mammalia, which live entirely on flesh. Hence, man seems to be capable of subsisting digestive as well as of various other organs, is better qualified for every diversity of aliment and climate than any other animal. Thus, many nations in a savage state live almost, perhaps altogether, on fruits and roots; as those of the yam, beet, and * Samml. Med. Wahrnehm., b. viii. p. 29. + Home’s Lectures on Comparative Anat., p. 340. ¢ Blumenbach’s Comp. Anat., p. 178. BZ Relative extent of the ali- mentary cavity. Omnivor- ous power of human stomach.