Ill 



THE THEOKY OF HUMAN NUTEITION 



109 



an animal diet : 41 per cent albumen, 30 per cent fat, 3 per cent 

 carbohydrate. The daily balance of nitrogen was on an average 

 as follows : 



As will be seen from these data, perfect nitrogenous equilibrium 

 was not attained ; for this reason Voit declared the diet to be in- 

 sufficient and unsuitable, considering the large quantity of nitrogen 

 which is unabsorbed and is wasted in the faeces. We may, how- 

 ever, fairly claim that perfect nitrogenous equilibrium would have 

 been attained had the investigations lasted longer. 



In order to ascertain whether the vegetarian who had for long 

 been used to such a diet made better use of it than a person 

 accustomed to a mixed diet rich in nitrogen, Voit experimented 

 on the servant of the Institute, a man weighing 74 kgrms., for a 

 period of three days, giving him the same diet as that to which 

 the vegetarian was accustomed. The nitrogenous balance showed 

 on an average a loss of nitrogen amounting to 4'95 grms. per day 

 (on the third day 3 '74 grms.). Although the experimental period 

 was extremely short, the result obtained is important, showing, as it 

 did, that the servant who was not used to a purely vegetable diet 

 made the same use of it as the paper-hanger who had been 

 accustomed to it for years. 



At the same time as Voit's experiments a work on the nutri- 

 tion of the Japanese was published in Germany by Kellner and 

 Mori (1889). Mori himself, a strong young Japanese of 23 years 

 of age, weighing 52 kgrms., was the subject of these investigations. 

 The experiments on the exchange of material were divided into 

 three series ; during the first was tried a purely vegetable diet, 

 like that general amongst the poorest class of agricultural labourers 

 in the interior of Japan ; during the second period a mixed diet 

 with fish; during the third a mixed diet with meat and milk. 

 The results obtained were not favourable to the vegetable diet, 

 during which Mori lost nitrogen continually an average of 1'16 

 grms. a day during the last three days. During the other two 

 periods, on the contrary, he gained nitrogen. If, however, we take 

 into account the fact that during the first period he took only an 

 average of 70'80 grms. of protein, whereas the amount during the 



