Page:Pure milk - a lecture delivered in the lecture room of the exhibition, July 30th, 1884 (IA b28525140).pdf/17

 washed away with the butter milk. Still the butter milk, as we see by the central bottle, retains fat, true butter fat, which of course represents so much waste in the process of butter-making.

Taking the other side of our case, where the skim milk heads the column, we have skim milk divided up into cheese and whey. The cheese is represented here by the proportions shown. One of these types is skim milk cheese, with its very small proportion of fat. These cheeses are common enough, and are usually consumed in this country, but there are many cases in which the use of whole milk cheese containing a large proportion of fat is desirable rather than cheeses containing so little fat.

The proportion of fat contained in these cheeses vary, from skim milk cheeses occasionally to be met with containing as little as three per cent, of fat, up to cream cheeses in which the proportion of fat is largely in excess of the proportion of caseine.

Now every one of these constituents we derive from pure milk is capable of being adulterated. There are one or two of these adulterations to which it is necessary I should refer. The most serious portion of adulteration unquestionably is the admixture of butter with foreign fats, and the substitution of inferior fats for the true butter present in cheese.

We will take the latter first. A large number of cheese consumers desire a cheese containing a considerable proportion of fatty matter. This fatty matter of course ought to be the butter natural to milk, but butter is far more valuable than oleomargarine, and therefore extensive manufactories have been established for the production of oleomargarine cheese. This cheese is made of skim milk, skimmed by separators, so that the butter is practically all abstracted, the deficiency of fat being replaced by the addition of oleomargarine or lard, in sufficient quantity to make the cheese a tolerably fat one. I look upon this as an exceedingly flagrant adulteration; the more so because it is one which is hardly likely to be detected by the consumer. There is no difficulty in detecting the fraud by an analytical