I have found that if the acid titanium cake is first slowly added to the barium sulphide solution and rapidly stirred, this discoloration will be avoided in the'sub sequent steps em loyed inthe manufacture of lithopone.

Lithopone, I may state, is a mixture of zinc sulfid and barium sulfate which has lately been placed upon the market as a very desirable material for use in the manufacture of paints or as a substitute for white lead. The standard grade of this product contains 29.4 per cent. of zinc sulfid, which, as will be seen, is a molecular mixture of the two ingredients named.