172 EXPERIMENT STATION KECORD. 



in the body weight due to an increase in cell substances. This increase 

 of cell substance under favorable conditions can be induced until the 

 body weight is doubled. Metabolism and productive power of the 

 body increased in direct proportion to the increase in body weight 

 induced by protein. The highest metabolism and the greatest produc- 

 tive power can therefore be induced onl}" bv the most abundant supply 

 of nitrogen in the food. Each diminution of the daily supply of protein 

 caused a decrease in the metabolism and productive power, even if the 

 protein omitted was replaced hy an amount of fat and carbohydrates 

 calculated to supply the same amount of energy. An increase in the 

 amount of fat or carbohydrates in the diet did not cause an increase in 

 metabolism or in the power of the body considered as a machine. Pro- 

 tein added to the diet replaces in the metabolism of the body a quan- 

 tity of fat possessing the same force value, provided, of course, that 

 the diet to which the protein is added contains fat, etc., as well as pro- 

 tein. The laws of the metabolism of protein are the same in dogs and 

 cats. No formation of fat from protein in the animal body, as insisted 

 upon by Voit and Cramer, was observed. Man can not be nourished 

 b}" protein alone, since it would l)e impossible to digest the amount 

 which would be required. According to the investigations of the 

 author and his pupils, a 3"Oung man instinctively uses an amount of 

 protein which is .sufficient for about one-fifth of the total productive 

 power of the body. Man can digest much more protein, but it seems 

 necessary to assume that for omnivora the protein consumed should 

 not exceed a certain limit. This is not proven, but man instinctively 

 refrains from an exclusive meat diet. 



Concerning direct and indirect calorimetric measurements 

 vrith animals in a study of nitrogen equilibrium -when fasting and 

 fed after fasting, P. P. Avrorov {Buss. Arch. Patol. Klin, i Bcikt.., 

 7 {lS90),j>. 4.JO; abs. in PMjsiologiste Russe, 1 {1899), No. 15-W, 2'>P- 

 304-306). — A number of experiments with dogs are reported. Some 

 of the principal conclusions follow. The metabolism of matter and the 

 production of heat takes place in animals with remarkable regularity 

 and uniformity when the experimental conditions are as uniform as 

 possible. The intensity of the metabolism of matter and the produc- 

 tion of heat in dogs is inversel}' proportional to the size of the animal 

 and directly proportional to the surface area. On an average during 

 the period of fasting the cleavage of fat was greatly diminished, while 

 the cleavage of proteids was reduced to a minimum. The heat pro- 

 duced was diminished 15 or 16 per cent and the production of carbon 

 dioxid was diminished from 21 to 22 per cent. Gains in protein were 

 made after fasting with little or no efi'ect upon the production of heat. 

 The all)umin of the living tissues of the body did not differ as regards 

 its }K)tential energy from the albumin of the meat fed. The pro- 

 duction of heat was found to be closelv connected with the excretion 



