On a New Method of Testing Milk. 589 
100 measures of the same milk, the following results were 
obtained : — 
Milk v?itb 
10 Per Cent, 
added Water. 
20 Per Cent, 
added Water. 
30 Per Cent, 
added Water. 
Feser's lactoscope indicated : — 
per cent. 
3 
per cent. 
2^ 
per cent. 
1-030 
1-027 
1-025 
In this case, again, the indications by Feser's lactoscope were 
satisfactory. 
It will further be seen that the admixture of water to milk in 
any considerable degree is at once detected by the lowering of 
its specific gravity, which in genuine good milk seldom falls 
below 1-029 or 1-028. 
The skim-milk from the July sample of milk on analysis 
gave the following results : — 
Com])osition of Skim-Milk. 
Water .. .. 87-50 
Butter-fat 2-86 
*Solidsnotfat 9-64 
100-00 
♦Including ash 0-72 
Specific gravity at 20° C 1-034 
Feser's lactoscope indicated 2i per cent, of butter-fat, a result 
which agrees very well with the real amount of fat in this 
sample. 
Diluted with 10, 20, and 30 per cent, of added water, the same 
skim-milk, when tested by Feser's lactoscope, gave the following 
results : — 
Skim-Milk diluted with 
10 Per Cent, 
of added 
Water. 
20 Per Cent, 
of added 
Water. 
3D Per Cent, 
of added 
Water. 
per cent. 
2 to 2i 
per cent. 
per cent. 
Specific gravity at 21° C 
1-032 
1-029 
1-027 
In these experiments the results obtained both by Feser's 
lactoscope and the hydrometer, showing the specific gravity, 
are satisfactory and useful in clearly showing in a most expe- 
