Chemistry 1.The alkaline salts of fatty acids,chiefly palmitic,stearic,or oleicacids. Soft soaps contain the potassium salts,whereas the sodium salts are hard soaps. Metallic soaps, water-insoluble compounds of fatty acids with bases of copper,aluminium,lithium,calcium ect. are used as waterproofing agents and the bases of many greases. 2.The alkali salts of resins, so-called resin soaps.