Page:A Treatise on Painting.djvu/267

 same method you may go on with two glasses, or three, till you have found what will best answer your purpose.   green, which is made of copper, though it be mixed with oil, will lose its beauty, if it be not varnished immediately. It not only fades, but, if washed with a sponge and pure water only, it will detach from the ground upon which it is painted, particularly in damp weather; because verdegris is produced by the strength of salts, which easily dissolve in rainy weather, but still more if washed with a wet sponge.   you mix with the Verdegris some Caballine Aloe, it will add to it a great degree of beauty. It would acquire still more from Saffron, if it did not fade. The quality and goodness of this Aloe will be proved by dissolving it in warm Brandy. Supposing the Verdegris has already been used, and the part finished, you may then glaze it thinly with this dissolved Aloe, and it will produce a very fine colour. This Aloe may be ground also in oil by itself, or with the Verdegris, or any other colour, at pleasure.  Rh