A question often arises as to the advisability of using kitchen-waste fats in making soap at home. While some housekeepers may find such use an economy, the fact remains that home-made soaps are generally poorly made and of inferior quality. The inferiority of home-made soaps may have several causes. The so-called cold process is usually followed in making these soaps, and rarely is the union of the fat with the lye complete. The fat used in home-made soap is often filled with impurities and they are not always removed before the soap is made. As the fat in kitchen waste varies greatly in composition, it is impossible to give the exact amount of alkali required for home-made soap. It is evident, then, that home-made soap is likely to be filled with impurities and to be both greasy and excessively caustic, " eating," because of the presence of free fat and an undue amount of free alkali. For the benefit of those housekeepers who wish to try its manufacture, however, a formula is given on page 256.