Polishing powders are advantageously prepared according to the following recipes:

I

Four pounds magnesium carbonate, 4 pounds chalk, and 4 pounds rouge are intimately mixed.

II

Four pounds magnesium carbonate are mixed with 1/4 pound fine rouge.

III

Five pounds fine levigated whiting and 2 pounds Venetian red are ground together.

IV

Kieselguhr......... 42 pounds

Putty powder...... 14 pounds

Pipe clay.......... 14 pounds

Tartaric acid....... 1.5 pounds

Powder the acid, mix well with the others. This is styled "free from mercury, poisonous mineral acids, alkalies, or grit." It may be tinted with 12 ounces of oxide of iron if desired.