Page:Pure milk - a lecture delivered in the lecture room of the exhibition, July 30th, 1884 (IA b28525140).pdf/18

 process. The very worst adulteration in the products is of course the use of oleomargarine to mix with or substitute for pure butter. I have nothing to say personally against the use of good carefully made oleomargarine as a substitute for butter, if only it is sold under its own name and at a fair price, but I have the greatest objection to its substitution for butter, which is more valuable and a more digestible diet, and unquestionably more suitable for domestic use. Good oleomargarine is nothing but the very best of beef fat carefully refined and carefully churned with milk, and as such no one can dispute its suitability for use as food; bad oleomargarine, on the other hand, is a compound of vile refuse fats, clarified and refined in any way that will chemically fulfil the object in view; but, to say the least, such a mode of preparing refuse materials for food use is objectionable, and the sale of the inferior sample should be in every way discountenanced.

I want to point out next the means which are available for ascertaining whether any given sample of milk is pure or not. In some respects this problem is comparatively a simple one, but in other respects it presents great difficulty. At the outset we meet with this difficult feature, that milk is a perishable article, and must be consumed within, at the most, a few hours of the time it was obtained from the cow. It follows from this, that it is not practicable for each sample of milk, or, for the matter of that, not one out of one hundred, to be subjected to chemical analysis before its distribution to the consumer; it is obvious, therefore, that some readier and more rapid test must be used or the milk must be sold without any test at all.

A good many different kinds of tests have been proposed for this purpose, and various instruments, under the name of galactoscope and other similar names, have been suggested, by which the degree of opacity of the milk could be read off according to scale, the idea of the inventors being, that the poorer the milk, the fewer would be the number of fat globules contained in it, and therefore the less the opacity of the milk. In practice these instruments signally failed,