336 REPORT OF THE CHEMIST OF THE 
acid used and that accounted for in the filtrate by titration 
with alkali represents the amount of acid corresponding to the 
casein present in the milk examined. 
Since one gram of free casein neutralizes 8.8378 ce. of tenth- 
normal sodium hydroxid (or 1 cc. of tenth-normal sodium 
hydroxid equals 0.11315 gram of casein),‘ we have a definite 
basis for estimating the amount of casein in any given case, 
when we know the amount of alkali it neutralizes, 
7 Ztschr. Analyt. Chem., 47.498. 
