In testimony whereof I afix my signature.

, 2. The herein-described process for manufacturing lithopone of various grades and a by-product of sodium hydrosulfid, which consists in preparing separate solutions of zinc sulfate and barium sulfid, which solutions are mixed with each other and with that of sodium bisulfate, all in equivalent and calculated amounts to produce and precipitate the desired grade of lithopone and leave the so dium hydrosulfid in solution, substantially as described.