3 i2 THE POPULAR SCIENCE MONTHLY. 



starch in its respiratory equivalent of fat, i. e., 390 parts meat and 126 

 fat, he eliminates daily only 28.3 parts solid matter, with 2.6 of nitro- 

 gen; while on the contrary, the liquid excretion holds 14.2 'if nitrogen. 

 Consequently, though the amount of albumen in the two cases was the 

 same, still twice as much of it was absorbed by the intestine from the 

 ration of meat as from that of vegetables. The 800 parts of meat 

 yielded only 27 of dry residuum. 



This difference in absorption makes the essential difference be- 

 tween vegetable and animal food. Consequently, we are not jus- 

 tified in saying that 2.4 of starch is the equivalent of one part fat. 

 Further, 1 part fat and 2.4 albumen, both absorbed by the same or- 

 ganism, have not the same action on the transformation of albumen or 

 the admission of oxygen. Great caution must therefore be observed, 

 in treating of such equivalencies, even where the elements of nutrition 

 are analogous, but come from diverse sources. Their mutually differ- 

 ent behavior in digestion has not been always taken into account. 



Dr. Hoffmann has studied this subject for the human economy, as 

 regards various alimentary substances or nutritive elements. Bread, 

 potatoes, rice, maize, etc., taken in any quantity whatsoever, can 

 scarcely support the life of man or of carnivorous animals, communi- 

 cating to them no bodily strength. Too large a proportion of their 

 nutritive elements is eliminated in the excretion. Still, with the addi- 

 tion of a small quantity of albumen, whether animal or vegetable, they 

 may suffice. They are poor in albuminates, but rich in starch. Even 

 herbivorous animals often take in an excess of food, so as to get the 

 requisite amount of albumen. 



The same occurs with man, and therefore he will waste non-azotized 

 material. The quality of the food he takes may be told from the ex- 

 creta. It is Liebig who said that you might make out the boundary- 

 lines of those countries where the coarse brown bread of Westjmalia 

 is used, from certain indications found along the hedge-rows. An Irish 

 laborer, according to Buckle, consumes daily 9 lbs. of potatoes, a 

 weight too great for all the intestines to carry. These potatoes would 

 contain of water 3,200 parts, dry albumen 70, and of non-nitrogenous 

 substances 725. The latter quantity is far in excess of what is neces- 

 sary to nourish a strong man ; but there is a deficiency of albumen, to 

 say nothing of the amount lost in the excreta. As a consequence, the 

 body is capable of but little work, notwithstanding the great quantity 

 of potatoes taken in, and it is but ill provided with the means of resist- 

 ing disease, owing to the excess of water in the organs. The same is 

 to be said of rice, which is poor in nitrogen. According to Salvator 

 Thomassi, the farmers of the rice-fields in Italy, who enjoy liberal fare, 

 reach an advanced age, while the day-laborers who live on rice suc- 

 cumb prematurely to diseases caused by exhaustion. In Western 

 India, where rice is the chief food of the natives, they always add 

 feonie element of food which is richer in azote. Those Italian laborers 



