A NEW EXPANDING MEDIUM.
I must mention here a newly discovered medium which has been found essential in the formation of beautiful veins in plain marble; take 1/10 quart of shellac orange, add 1/8 quart spirits of ammonia, allow the whole to boil for 5 minutes stirring repeatedly (by which a uniform solution of shellac in ammonia is obtained), take it from the fire and dilute the solution with about 2 quarts of water. Throw the fluid by means of the brush on the size and then throw on the body-color, see [plain gray marble]. In this way beautiful white veins will appear, which is explained by the fact, that the surface of the size is covered with an expanding medium, which can be forced together by the body-color, but is strong enough to hinder the union of the latter.