_Oleomargarine._--About 1868 M. Mege, a French chemist, commissioned by his government to investigate certain questions of domestic economy, was led into the study of beef fat, and to make comparisons of the same with butter. He found that when cows were deprived of food containing fat they still continued to give milk yielding cream or fatty products. He therefore concluded that the stored-up fat in the animal was then converted into cream, and that it was practicable, therefore, to convert beef fat into butter fat. Physiology taught that in the living animal the change was wrought through the withdrawal of the larger part of the stearine by respiratory combustion, while the oleomargarine was secreted by the milk glands, and its conversion into butyric oleomargarine effected in the udder under the influence of the mammary pepsin. In the process of making butter by the ordinary method of churning the cream, the finely divided butter fat globules are united into masses, containing by mechanical admixture from 12 to 14 per cent. of water or buttermilk carrying a fractional per cent. of cheese. This buttermilk contributes somewhat to the flavor, but at the same time furnishes a ferment which ultimately spoils the butter by making it rancid. It is a purely accidental ingredient, and one not at all desirable. To some extent the same may be said of the soluble fats which give to the butter its variable though characteristic flavor. They are unstable compounds, decomposing readily, and furnish the acrid products which make “strong” butter. M. Mege sought to imitate the natural process of butter-making, which was first to separate from the oily fat of suet the cellular tissue and excess of stearine or hard fat; second, to add to the oil a sufficient proportion of butyric compounds to give the necessary flavor, and third, to consolidate the butter fat without grain, and to add at the same time the requisite proportion of water, salt, and coloring matter, to make a compound substantially the same in composition, flavor, and appearance, as butter churned from the cream, and all this without adding to the original fat anything dietetically objectionable, and without submitting it to any process capable of impairing its wholesome quality. These objects were fairly obtained in the product known as oleomargarine, the United States patent for which was granted to Mege Dec. 30, 1873, No. 146,012.