FOOD OF MAN. 549 



on the subject. A great deal, doubtless, depends on the habits of the 

 particular animal or individual; and on the morbid effects excited by 

 completely changing the function of assimilation. It has been long 

 known, that if a man, previously habituated to both animal and vege- 

 table diet, be restricted exclusively to one or the other, he will fall off, 

 and become scorbutic; and yet, that he is capable of subsisting on 

 either one or the other exclusively, provided the restriction has been 

 enforced from early infancy, has been sufficiently shown by the refer- 

 ence made to carnivorous and herbivorous tribes existing in different 

 regions of our globe. The importance of variety of diet is illustrated 

 by the experiments made by Dr. Stark, 1 upon his own digestive powers, 

 and to which he ultimately became a martyr. His object was to dis- 

 cover the relative effect of various simple substances, when used exclu- 

 sively for a long space of time as articles of food. The system, he 

 found, was in all cases reduced to a state of extreme debility, and there 

 was not a single aliment, that was capable, of itself, of sustaining the 

 vigour of the body for any considerable period. By this kind of regi- 

 men Dr. Stark is said to have so completely ruined his own health, as 

 to bring on premature death. 



In accordance with his views, that nitrogenized food is alone capable 

 of forming organized tissue; and that the non-nitrogenized food is in- 

 servient to respiration only, Liebig thus classifies aliments: 



Nitrogenized Food or Plastic Elements of Non-nitrogenized Food or Elements of Respi~ 



Nutrition. ration. 



Vegetable Fibrin, Fat, Pectin, 



" Albumen, Starch, Bassorin, 



" Casein, Gum, Wine, 



Flesh, Cane Sugar, Beer, 



Blood. Grape Sugar, Spirits* 



Sugar of Milk, 



These views, however, demand further proof. They are not confirmed 

 by what is observed in chylification. In the small chyliferous vessels, 

 more fat, which is a non-nitrogenized substance, is found than can be 

 accounted for by the adipose matter in the food; and of the conver- 

 sion of the amylaceous and saccharine matters in the food to oil during 

 the digestive function a striking example has been published by M. 

 Koss. 2 A workman was killed on a railroad after having eaten a 

 full meal of bread and grapes only. On examining his body, the pro- 

 cess of chymification was found to have been in full activity; and in 

 those portions of the small intestine, which the chyme had reached, 

 the mucous membrane was dotted with white points, which, on closer 

 examination, were found to be owing to drops of oil in the epithelial 

 cells surrounding the extremities of the villi. As the chyle proceeds 

 along the lacteals, the proportion of fat becomes less and less, whilst 

 that of the nitrogenized matters increases; hence nitrogen must 

 have been obtained, and a conversion have taken place of non-nitro- 

 genized into nitrogenized matters. (See PHYSIOLOGY OF CHYLOSIS.) On 

 the other hand it has been shown, that the followers of Liebig maintain, 



1 The Works of the late Wm. Stark, M. D., &c., by Dr. J. C. Smyth., Lond., 1787. 

 * Cited in Londqn Med. Gazette, Oct., 1846. 



