176 Oscar Riddle 



had failed to satisfy- Six plymouth rock hens in good condition, 

 not laying, were isolated for the experiment. Quite at random 

 three of these hens were taken arid given food + Sudan capsules 

 for two days; the other three were given food but no Sudan. The 

 birds were then all removed to a pen where they could get no 

 trace of food; only water was given them. The weight of each 

 bird was taken at the beginning and on each third day of the ex- 

 periment during its fifteen days of duration; the object of all this 

 being to learn which group of birds would lose weight faster. It 

 was thought that those using most fat would lose least weight and 

 vice versa; viz., that energy must be supplied to the birds during 

 life, that if they secure this energy from the fats of their bodies 

 instead of from their protein, they will need to use fewer grams 

 to obtain any desired amount of energy since the energy content 

 of fats is to that of proteins as about 9.3 to 4.1. An important 

 part of the records of the weighings unfortunately has been mis- 

 placed and the writer cannot give the exact figures; but the 

 net result showed that each of the Sudan-fed birds had lost, at the end 

 of the period, a higher percentage of its initial zveight than had cither 

 of the non-fed birds. 



Chemical Evidence 



{']) It was thought that if the stained fat were less available 

 to the organism, as seems to be the case, this might be connected 

 with a decreased power of the fat-splitting ferment to split such fat. 

 The following attempt was made to determine this point; lipase 

 was prepared from the castor bean and equal quantities of this 

 was put into flasks, one set containing oil +Sudan, the other pure 

 oil only. Flasks of the two sets, left on the shaking machine and 

 given time for hydrolysis, were then titrated with n 10 Na O H, 

 and compared. It was found, however, that the strong and per- 

 sistent color of the Sudan so obscured the expression of the indi- 

 cators that it was quite impossible to determine the neutral point 

 in the Sudan-containing flasks. The titration method of estimat- 

 ing the rate of hydrolysis of the fat, therefore, had to be given up. 

 An attempt was next made to determine the rate or amount of 

 digestion in the two sets of flasks by measurements of their elec- 



