From the sugar:—
4·40: sugar found = 100 : x.
From the specific gravity:—
1·030 : sp. gr. = 100 : x.
In most cases the determination of the total milk-solids and the fat (the difference being the solids not fat) furnishes all the data required for determining the amount of watering which a sample of milk has undergone. The Society of Public Analysts use 9 as the average percentage of solids not fat in pure milk (which is generally considered as too low) and adopt the formula:—
100 9 S = x,
in which x represents the percentage of genuine milk, and S the solids not fat.
PLATE IV.
Cream × 420.