7. _Chrome yellow._

Pad in a solution of bichromate of potash containing 8 ounces of it to

the gallon of water; then dry with moderate heat, and pad in a solution

of acetate or nitrate of lead, containing 6 or 8 ounces in the gallon of

water; wash, and dry. Or we may pad first in a solution of acetate of

lead containing a little glue; dry, and pad in solution of bichromate of

potash. Then rinse. The last process is apt to occasion cloudiness. To

obtain a light lemon tint, we must pad in a solution of acetate of lead

of double the above strength, or 16 ounces to the gallon, then wince the

pieces through weak milk of lime, rince, pad through bichromate of

potash, rinse, and dry.

A Dictionary of Arts, Manufactures and Mines containing a clear exposition of their principles and practice · 第 54 / 421 题