METABOLISM AND FOOD 75 



ducted. A further deduction had to be made for 

 the fat (26-1 gr.) which might, according to Henne- 

 berg's figures (p. 65) be formed from the 49 gr. of 

 flesh in the food. So a total deduction of 26-1 x 5 = 

 I 3°'5 g r - na( i to be added to the 150 gr. present in 

 the body at the beginning of the experiment. 

 Subtracting these two amounts 280-5 from 13527, 

 the fat added to the body, there is left 1072.2 gr. 

 which could only have come from the food fat. 

 This divided by five gives the daily addition of 

 214-4 gr. of fat from the 370-8 gr. of fat (and the 

 small quantity of flesh) in the food. 



Numerous other experiments, in which the 

 materials going into and leaving the body were 

 carefully measured by means of a respiration ap- 

 paratus (p. 46), confirm these results. An example 

 is seen in experiment III of the table on page 72. 



The determination of the quantity of body fat 

 which can arise from a known quantity of food fat 

 has been carried out on fattening oxen, and it has 

 been shown that 1 kilo emulsified earth-nut oil 

 causes an increase of 598 gr. in the fat of the body. 

 Thus 64-4% of the energy of the digested oil has 

 been retained as newly-created body fat, and 35-6% 

 has been lost. The fat from the different kinds of 

 hay or straw possesses a considerably smaller energy 

 value (p. 70), and a kilogram of it would only pro- 

 duce 474 gr. body fat. The cereal grains and their 

 by-products yield fats which take a medium posi- 



