be worth trying, although it would have a very unpleasant smell. In this connection may be mentioned the fact that, when bran drenches are used, in which lactic acid is developed, the butyric fermentation is liable, in hot weather, to take its place, and as butyric acid is a powerful solvent of gelatinous tissue, and the dissolved tissue itself feeds the fermentation, rapid destruction of the skins is the result. Cleanliness, scalding out of the drench vats, and washing the bran before using with cold water to remove adhering flour, are useful precautions. If the removal of the lime be the only object aimed at in bating, the ordinary process is most wasteful, as well as disgusting, from the loss of pelt it entails. It is easy to find chemical reagents which will remove the lime; but the resultant leather has been found wanting in softness, and it is probable that the solution of the inter-fibrillar matter is in many cases advantageous. Probably one reason for the non-use of such chemicals is their expense. Maynard has patented the use of sulphurous acid for the purpose. If sugar, glucose, or ammonia salts be used, and the alkalinity of the solution nearly neutralised after each lot of hides by common vitriol, the same liquor may be used again and again. In this case, if iron is contained in the acid it will be precipitated by the ammonia and must be settled out. The writer is convinced, from his own experience, that with suitable tannage such bating would yield better weights and quite as satisfactory leather for many purposes as the ordinary mode. French tanners, by the free use of water, and careful working at the beam, and the employment of very weak liquors at the commencement of tanning, make excellent dressing leather without bating and this is also true of the celebrated French calf. The bating required may be shortened, and probably with advantage, by washing the hides with warm water in a "tumbler," or rotating drum, Fig. 49, prior to putting them into the bate, or the whole bating may be done in the tumbler. After a short bating, also, the hides may be softened and cleansed by stocking for 15-20 minutes. Warm bates act much more rapidly than cold ones. [Illustration: Fig. 49.] Various machines have been proposed to take the place of hand-labour in the beam work, and, at least as regards the smaller skins, with considerable success. As a type of these, may be mentioned Molinier's hide-working machine, Fig. 29, which consists of a drum covered with helical knives, rotating at a speed of about 500 rev. a minute, over a cylinder coated with india-rubber. The skin is allowed to be drawn in between these drums, and the two being pressed together by a treadle, it is drawn out by a mechanical arrangement in a direction contrary to the rotation of the knives, which scrape off the flesh, or work off the hair.