To the Editor of the "Mobrh-ChrkA Dany New Sm—As an analytical chemist having had considerable experience in the analysis of fats, I have much pleasure in giving particulars of a method to distinguish margarine from butter, as is requested by one of your @rrespondents. The method in question consists in heating the sample and observing the results The details of the method are as follows:
A smal lump of the sample of margarine or butter about three grams) is heated in a large spoon over a small flame, The melting fat is stirred constantly during the heating with 4 splinter of wood, such as a match. After the fat pletely melted, the heat is in so that the liquid fat shall boil briskly During the boiling. the fat is stirred thoroughly several times, the outer edges of the spoon noi being neglected.
If the fat is margarine. it will boil noisily (usually sputtering like a mixture of grease and water when boiled), and little or no team will be produced. If the fat is genuine, it will boil with much less noise. and a considerable amount of foam will be produced: this foam often swells up over the sides of the spoon when the spoon is temporarily removed from the flame. The difference concerning the foam is very marked The appearance of the particles of curd after the boiling should also be noted. In the case of genuine butter. these particles of curd will be very small and finely divided (being hardly perceptible in fact), while with mar-gonne the curd will gather In much larger masses or lumps.
There are also other methods for distinguishing margarine from butter, but the writer's experience with the above-mentioned test has shown it to be very reliable, Cmbbk Wee.
Shanghai, Feb. 5
Text read from the printed page and cleaned; old type leaves the occasional error.