It may be that the glycerine of the fat we eat is assimilated like sugar, while the fatty acids act directly as fuel. This view may reconcile some of the conflicting facts (such as the existence of fat in the carnivora) that stand in the way of the theory of the uses of fat food above referred to, according to which fat is not fattening, and those who would ‘Bant’ should eat fat freely to maintain animal heat, while very abstemious in the consumption of sugar and farinaceous food. The difference between tallow and dripping is instructive. Their origin is the same; both are melted fats—beef or mutton fats—and both contain the same fatty acids and glycerine, but there is a visible and tangible difference in their molecular condition. Tallow is smooth and homogeneous, dripping decidedly granular. I attribute this difference to the fact that in rendering tallow, the heat is maintained no longer than is necessary to effect the fusion; while, in the ordinary production of dripping, the fat is exposed in the dripping-pan to a long continuance of heat, besides being highly heated when used in basting. Therefore the dissociation is carried farther in the case of the dripping, and the result becomes sensible. I have observed that home-rendered lard, that obtained in English farmhouses, where the ‘scratchings’ (_i.e._ the membranous parts) are frizzled, is more granular than the lard we now obtain in such abundance from Chicago and other wholesale hog regions. I have not witnessed the lard rendering at Chicago, but have little doubt that economy of fuel is practised in conducting it, and therefore less dissociation would be effected than in the domestic retail process. Some of the early manufacturers of ‘bosch’ purified their fat by the process recommended and practised by the French Academicians MM. Dubrunfaut and Fua (see page 102). I wrote about it in 1871, and consequently received some samples of artificial butter thus made in the Midlands. It was pure fat, perfectly wholesome, but, although coloured to imitate butter, had the granular character of dripping. Since that time great progress has been made in this branch of industry. I have lately tasted samples of pure ‘bosch’ or ‘oleomargarine’ undistinguishable from churned cream or good butter, though offered for sale at 8½_d._ per lb. in wholesale packages. In the preparation of this the high temperatures of the process of the Academicians are carefully avoided, and the smoothness of pure butter is obtained. I mention this now merely in confirmation of my theory of the _rationale_ of fat cookery, but shall return to this subject of ‘bosch’ or butterine again, as it has considerable intrinsic interest in reference to our food supplies, and should be better understood than it is.