Xew Yokk Agricultural Experiment Station. 



317 



alcohol, which was free from acid, until the calcium caseinate was 

 precipitated, after which the precipitate was washed with alcohol 

 and ether, and dried at 120° C. A weighed portion of this compound 

 was carefully ignited and the calcium in the resultmg ash was deter- 

 mined, with the following results : 



Table II. — Amount of Ca Combining With Casein When Reacting With CaCOs. 



Preparation of basic calcium caseinate by treating casein with an 

 excess of calcium hydroxide. — Weighed portions of casein were dis- 

 solved in an excess of lime-water. Phenolphthalein indicator was 

 then added to the solution and hydrochloric acid was run in until 

 the solution became neutral. The solution was then dialyzed to 

 remove the calcium chloride formed in neutralization. The dialyzed 

 solution was evaporated to dryness, the residue dried at 120° C. 

 and weighed. The determination of calcium was made after ignition, 

 with the following results: 



Table III. — Amount of Calcium Combining With Casein on Treatment With 



Calcium Hydroxide. 



The three sets of figures presented in Tables I, II, and III indicate 

 that casein combines with calcium to form a compound containing 

 about 2.50 per ct. CaO (equal to 1.78 per et. Ca); the compound in 



