New York AGRICULTURAL EXPERIMENT STATION. Tyo 
there is added about one gram of common salt, together with an 
excess of ten per ct. tannic acid solution. The precipitate 
formed is filtered and washed and the nitrogen determined in an 
aliquot part of the filtrate. From this amount of nitrogen is 
deducted the amount of nitrogen found as ammonia in (g) and 
the remainder is the amount of amide nitrogen. 
(c) Ammonia.—To an aliquot portion of the filtrate obtained 
in (f), magnesium oxide is eaded and the ammonia separated by 
distillation. 
DETERMINATION OF NITROGEN-COMPOUNDS IN MILK. 
Casein.—To 20 gms. of milk, diluted with water to about 
100 cc., are added 2 to 23 cc. of saturated alum solution. The 
determination is completed as under (b) in cheese extract, and 
the other determinations are made as described above in the 
cheese extract. 
DETERMINATION OF CHLOROFORM IN CHEESE AND MILE. 
About 5 gms. of milk or cheese are placed in a pressure bottle 
with about 10 cc. of alcohol and 5 gms. caustic potash. The 
bottle and contents are then heated 30 minutes at 230° F. 
(110° C.) in an autoclave. The resulting chloride is determined 
volumetrically as in case of chlorine in sodium chloride. 
FORM OF STATING RESULTS. 
The figures given in the various tables represent percentages 
of the total nitrogen in milk and cheese. This form of state- 
ment is usually preferable, as figures representing the actual 
percentages in milk and cheese are often very small. Hence, 
considerable variations, expressed in percentages of nitrogen, 
often represent very small variations when expressed in actual 
amounts present in cheese and milk. 
The soluble nitrogen in milk, as used in this bulletin, includes 
all nitrogen compounds except casein and albumin. The water- 
soluble nitrogen in cheese includes all the nitrogen soluble under 
the conditions indicated in preparing the water extract of 
cheese, 
