INDIRECT CALORIMETRY 31 



hydrates ; the closer the ratio comes to unity the more carbo- 

 hydrates are being oxidised, and vice versa. 



(VIII) Now, knowing the proportion of carbohydrate and fat 

 in the diet, one may calculate the amount of energy set free 

 from the two following figures : 



(a) If carbohydrate alone is used each litre of O 2 =5-047 cals. 



(b) If fat -4-686 cals. 



Intermediate values may be obtained by interpolation. The 

 results obtained by indirect calorimetry are within 2 per cent, 

 of results from the respiration calorimeter. 



In a series of twenty-two different experiments with a dog, 

 Murlin and Lusk obtained the following results : 



Indirect calorimetry - - 2244 cals. 



Direct 2230 



Difference - 14 ,, 



Percentage - 0-6 



