248 . Report oF THE CHEMIST OF THE 
rated in a mortar with water and finally allowed to drain on a fil- 
ter paper. It was then removed from the filter paper, mixed 
with water at 45° to 50° C., triturated again and filtered again. 
This was repeated four or five times a day and continued until 
the filtrate gave no test for chlorides. This required four days. 
When the precipitate had finally been drained, it was washed 
with 95 per ct. alcohol. Some of the proteid went into solution, 
owing to dilution of the alcohol by the water still present in the 
precipitate; and this partial solution stopped only after a large 
volume of alcohol had been used. The precipitate was finally 
washed with ether and dried at 100° C. The product thus pre- 
pared was a very friable white powder. It was still somewhat 
soluble in hot 50 per ct. alcohol and warm 5 per ct. salt solution. 
These solubilities are much more marked before treatment with 
strong alcohol and ether. The product was practically ash-free, 
5.28 grams yielding an ash of ,02 per ct. The preparation was 
quite free from chlorides, this being shown in the following man- 
ner:—We dissolved .5 gram in hot concentrated nitric acid, to 
which was added a crystal of silver nitrate. The whole was 
boiled until complete solution of the proteid had occurred. No 
precipitate of silver chloride was formed. 
Preparation 2, by Hanvmarsten’s method.—We used 2 liters of 
skim-milk in making this preparation and followed in exact 
detail the method described by Hammarsten.? Before treatment 
with alcohol, this preparation was readily soluble in warm dilute 
salt solution and in 50 per ct. hot alcohol. It contained 1.06 
per ct. of ash. It was shown to be free from acetates in the fol- 
lowing manner :—We dissolved .5 gram in dilute sodium hydrox- 
ide, then precipitated the proteid by hydrochloric acid and fil- 
tered. The filtrate was made alkaline and evaporated to dryness. 
The residue gave no evidence of ethyl acetate when heated with 
alcohol and sulphuric acid. 
Preparation 3, by use of hydrochloric acid.—We used 2 liters 
of skim-milk, diluting it with 15 liters of warm distilled water, 
and precipitating the casein by hydrochloric acid. The separated 
proteid was allowed to drain on. filter paper and then washed 
with water at 45° ©. It was then mixed with water and 
® Maly Jahresber, d. Thierchem., 7:159 (1877). 
