348 REPoRT OF THE CHEMIST OF THE 
Results of different workers are usually within 0.2 per ct. 
of the official method. Variations greater than this have been 
found to be due to failure to observe with proper care the 
various precautions indicated. 
The method was placed in the hands of the dairy students 
of the College of Agriculture of Cornell University during the 
winter of 1908-9 for the purpose of ascertaining whether uni- 
form results could be obtained by different individuals. Satis- 
factory results were reported. Dr. Redfield, also of Cornell 
University, reports that the method gives excellent results in 
his hands. 
The following table contains data illustrating the results 
of casein determinations made in fresh milks and after 3 and 
7 days in the same milk containing mercuric chlorid. 
PERCENTAGES OF CASEIN IN MILK TREATED Witn MERCURIC CHLORID. 

Official method. Volumetric method. 
Fresh milk. Fresh milk. At 3 days. At 7 days. 

2.47 2.55 2.50 2.50 
2.60 2.40 2.65 2.55 
2.64 2.60 2.65 2.70 
2.78 2.80 2.70 2.75 
2.81 2.90 2.90 2.80 
2.81 2.85 2.70 2.75 
2.87 2.90 2.90 2.85 
3.00 3.00 3.00 3.05 
3.00 3.00 3.00 3.00 
3.03 3.05 3.05 3.05 
3.04 3.00 3.00 3.00 
3.12 3.05 3.05 3.00 
3.13 3.15 3.15 3.15 
3.16 3.10 3.10 3.10 
3.18 3.20 3.10 3 10 
3.29 3.30 3.30 3.30 
3.43 3.30 3.35 3.50 
3.59 3.60 3.50 3.55 
3.78 3.80 3.60 3 70 
3.86 3.80 3.80 3.70 
4.04 4.20 4.20 4.20 
