FOOD OF MAN. 547 



In the period that elapsed between the publication of the first and 

 second editions of his Precis Element air e de Physiologic, M. Magendie 

 found that his deductions were not, perhaps, as absolute or demonstra- 

 tive as he had at first imagined; and additional experiments induced 

 him to conclude, as Dr. Bostock 1 afterwards did, without being aware, 

 apparently, of his observation, "that variety and multiplicity of 

 articles of food constitute an important hygienic rule." " This," M. 

 Magendie 2 adds, "is indicated to us by our instinct, as well as by the 

 changes that wait upon the seasons, as regards the nature and kind of 

 alimentary substances." The additional facts, detailed by M. Magendie, 

 are the following : A dog, fed at discretion on pure wheaten bread, 

 and drinking common water, does not live beyond fifty days; whilst 

 another, fed exclusively on military bread pain de munition seems 

 to suffer hi no respect. Rabbits or Guinea-pigs, fed on a single sub- 

 stance, as wheat, oats, barley, cabbage, carrots, &c., commonly die, 

 with every mark of inanition, in a fortnight; and, at times, much 

 earlier. When the same substances are given together, or in succes- 

 sion, at short intervals, the animals continue in good keeping. An 

 ass, fed on rice, lived only fifteen days, refusing his food for the last 

 few days ; whilst a cock was fed upon boiled rice for several months 

 without his health suffering. Dogs, fed exclusively on cheese, and 

 others on hard eggs, lived for a long time ; but they were feeble and 

 lean, losing their hair, and their whole appearance indicated imperfect 

 nutrition. The substance, which, when given alone, appeared to sup- 

 port the rodentia 3 for the greatest length of time, was muscular flesh. 



Lastly, M. Magendie found, that if an animal had subsisted for a cer- 

 tain time on a substance, which, taken alone, is incapable of nourishing 

 it, on white bread, for instance, for forty days, it is useless, at the 

 end of that time, to vary his nourishment, and restore him to his ac- 

 customed regimen. He will feed greedily on the new food presented 

 to him; but continues to fall off; and dies at the same period as he 

 would probably have done, if maintained on his exclusive regimen. 

 That these effects are not owing to privation of nitrogen, the same ob- 

 server 4 has since been amply satisfied. As chairman of a committee 

 appointed to inquire into the nutritive properties of gelatin, he reported 

 that gelatin, albumen, and fibrin all of which are highly nitrogenized 

 when taken separately, nourish animals for a limited period only, 

 and imperfectly. They generally soon excite so insurmountable a dis- 

 gust that the animals would rather die than partake of them. These 

 experiments led to the too hasty conclusion, that the gelatinous tissues 

 are incapable of conversion into blood. "The gelatinous substance," 

 says Liebig, 5 "is not a compound of protein; it has no sulphur, no 



1 Physiology, 3d edit., p. 561, Lond., 1836. 2 Qp. chat., ii. 494. 



3 The rodentia are gnawing animals, having large incisors in each jaw, with which 

 they divide hard substances. They are the rongeurs of the French naturalists. The 

 squirrel, mouse, rat, Guinea-pig, hare, rabbit, beaver, kangaroo, porcupine, &c., belong to 

 this division. 



4 Comptes Rendus, Aout, 1841. Similar results were obtained by the Amsterdam Com- 

 mission, in Het Instituut, No. ii. 1843, pp. 97-114, cited by Mr. Paget, Brit, and For. Med. 

 Rev., April, 1845, p. 563. 



5 Animal Chemistry, Amer. edit., by Webster, p. 124, Cambridge, Mass., 1842. 



