There are several recipes for making one-bath liquors. A favourite mixture consists of chrome alum and sodium carbonate (common soda). Another method consists of reducing a solution of chromic acid with glucose or grape-sugar. This liquor has a greater plumping effect on the leather than the chrome alum liquor has. A third process of making a one-bath liquor combines the use of bichromate of potash and chrome alum, which, when dissolved, is converted into a basic chrome salt by means of a reducing agent. The one-bath liquor can be easily and safely applied to hides and skins, and is used in much the same manner as a vegetable tan liquor, beginning with a weak solution and gradually increasing the strength until the process is completed. The two-bath method needs great care, as a slight difference in the proportions of the ingredients used may alter the character of the leather produced. The formula now largely used is practically the same as that of the original patentee, Augustus Schultz, an American chemist. The first bath, the chromic acid solution, is made by treating bichromate of potash or soda with hydrochloric, sulphuric, or formic acids. Bichromate of potash and hydrochloric acid (commonly known as muriatic acid, or spirits of salts) are commonly used, and in the proportion of 5 per cent. and 2-1/2 per cent. of the weight of the drained pelts (5 lb. of bichromate and 2-1/2 lb. of acid for 100 lb. of pelts). The chemical reaction is represented by the following equation-- K_{2}Cr_{2}O_{7} + 2HCl = 2KCl + 2CrO_{3} + H_{2}O Bichromate of potash + Hydrochloric Acid = Potassium chloride + chromic acid + water.