III. GREENS. Brilliant-greens are produced with great difficulty. In Switzerland, they have a method
Crayon. of making them far superior to ours. We usually take yellow ochre, and after grinding it with spirits, mix it with the powder of Prussian blue, then temper it with a knife, and lay the crayons on the chalk, without rolling them. Instead of this, some use king's yellow mixed with Prussian blue, and others brown ochre and Prussian blue. The crayons made of the two last may be rolled. Various teints may be produced by these colours, according to fancy or necessity; some to partake more of the blue, and others of the yellow.