Oleo-Margarine, a substance produced from tallow and resembling butter, so called by Mége-Mouriez, according to the idea that, as asserted by Chevreul, butter contains margarine; but this opinion has been generally abandoned. Mege-Mouriez had observed that the milk of cows was not deprived of butter long after they were subjected to extremely scanty feeding; from which he concluded that the fat of the animal was converted into butter. Taking suet, which contains less oleine than butter, he extracted a certain proportion of palmitine and stearine, until the proportion of oleine was sufficient to give it the consistence of butter. Fresh meat cut fine, a small portion of carbonate of soda, and sheep's stomachs, also cut fine, are put into a vessel with water and heated to 113° F.; this causes the fat to separate from the cellular tissue, and being subjected to great pressure it separates into a firm stearine and palmitine, and an oil which on cooling has the consistence of butter. This substance (oleo-mar-garine), while liquid, is combined with about its own volume of a mixture of equal parts of milk and water.

Some water, in which cows' udders containing milk glands have been digested, is added, with a little annotto for coloring, and the mixture is then churned; on cooling the fatty matter collects in a manner resembling that when cream is churned to butter. The artificial butter is washed with cold water and salted like natural butter.