476 PHYSIOLOGICAL CHEMISTRY. 



nutritive Bodies which must be taken in, and not those which are 

 really absorbed. The figures for the calories, which here and in the 

 following pages are so-called gross calories are, on the contrary, net 

 results. 



The various foods are, as is well known, not equally digested 

 and absorbed, and in general the vegetable foods are less completely 

 used up than animal foods. This is especially true of the proteids. 

 When, therefore, VOIT, as above stated, calculated the daily amount 

 of proteids needed by a laborer as 118 grms., he starts with the 

 supposition that the diet is a mixed animal and vegetable one, and 

 also that of the above 118 grms. about 105 grms. are absorbed. 

 The results obtained by PFLUGER and his school, BLEIBTREU and 

 BOHLAND, for the extent of the metabolism of proteids in man with 

 a diet optional and sufficient correspond well with the above figures 

 when the unequal weight of the body of the various persons 

 experimented upon is sufficiently considered. 



As a rule, as a more exclusively vegetable food is employed, the 

 amount of proteids in the same is also habitually smaller. The 

 strictly vegetable diet of certain people as of the Japanese and 

 that of the so-called vegetarians is therefore a proof that a person, 

 if the quantity of food be sufficient, may exist on considerably 

 smaller quantities of proteids than VOIT suggests. It follows from 

 the investigations of HIRSCHFELD and KUMAGAWA that a nearly 

 complete or indeed a complete nitrogenous equilibrium may be 

 attained by the sufficient administration of non-nitrogenized nutri- 

 tive bodies with relatively very small amounts of proteids. Hirsch- 

 feld, who weighed 73 kilos, could maintain nitrogenous equilibrium 

 very nearly with a diet containing 43.5 grms. nitrogeriized bodies, 

 165 grms. fat, 354 grms. carbohydrates, and 42.7 grms. alcohol. 

 Kumagawa made experiments on himself with a purely vegetable 

 diet, consisting mainly of boiled rice. On an average 50.5 grms. 

 proteids and 569.83 grms. carbohydrates were daily introduced, and 

 of this 37.82 grms. proteids and 566.7 grms. were daily used up 

 By this food he was not able with a bodily weight of 48 kilos to 

 attain nitrogenous equilibrium, but he found indeed that a part of 

 the nitrogen was retained in the body. The weight of the body 

 increased and the general condition was good. The total amount 

 of calories in the absorbed food was in this case 2500 in round num- 



