5 



FEEDING EXPERIMENTS WITH ISOLATED FOOD SUBSTANCES. 



Rat 72. This rat was fed with the same mixtures as those fed 

 to rat 71 during the corresponding periods. 



Table XXIX. Summary of Data on Rat 72, fed for 141 Days on Mixtures 

 Containing Casein and Glutenin as the only Proteins. Daily Averages. 



Rat 73. This rat was fed during Period 1 on a mixture con- 

 taining casein 12, zein 6, sugar 15, starch 29.5, lard 30, agar 5, salt 

 mixture I 2.5 per cent, and nitrogen 2.38 per cent. In order to secure 

 good utilization of the zein it was necessary to hydrate it by incor- 

 porating in the food 10 cc. of water per 100 grams of the mixture. 

 The nitrogen content of the different batches therefore varied from 

 2.30 to 2.48 per cent. The actual nitrogen content of each batch 

 fed was used in calculating the nitrogen balance which is given in 

 table XXX. During Period 2, the diet contained pea legumin 18, 



