An American plan, sometimes known as the "Buffalo method," is described by Jackson Schultz. The hide is prepared in the usual way, and is then thrown into a strong lime for 8-10 hours, when it is taken out and immersed in water heated up to 110° F. (43° C.), in which it remains 24-48 hours. The warm water soaks, softens, and swells the roots of the hair, and much the same result is obtained as in "scalding" pigs. So little lime really permeates the inner fibre that, after a slight wheeling, the hides may be thrown into cold water, and allowed to cool and plump, preparatory to taking their places in the handlers. The process is strongly recommended for sole-leather, particularly where great firmness of fibre is desired. The tanner who tries it must be satisfied if he gets 20-30 sides a man unhaired and fully ready for the liquor per diem. Of course this process may be varied to any extent by giving more liming, and less hot water, and this is frequently done in America. About 3-4 days' cold liming in good limes, and with hauling if possible twice daily, followed by 12-24 hours in water at 86°-95° F. (30°-35° C.), which should be changed at least once, will give good results. The hides are of course less plump than usual, but if properly managed in the handlers will swell well in the tan-house. Grease is obviously less thoroughly "killed" than in the ordinary method, and especial care must be used that the hides are well worked on the beam, both on grain and flesh. In this method, and indeed in all liming processes, much is gained if the fat can be fleshed off green. [Illustration: Fig. 24.] On the Continent and in America, the prevalent mode of loosening the hair, at least for sole-leather purposes, is called "sweating," and consists in inducing an incipient putrefaction, which attacks the soft parts of the epidermis and root-sheaths, before materially injuring the hide-substance proper. The old European method of "warm-sweating" consisted simply in laying the hides in pile, and, if necessary, in supplying heat by covering them with fermenting tan; but as this crude and dangerous process is everywhere being supplanted by the American plan, where sweating at all is adhered to, it is not necessary to do more than describe the latter. This is called "cold sweating," but really consists in hanging the hides in a moist chamber, kept at a uniform temperature of 60°-70° F. (15°-21° C.); or in some cases slightly warmer.