Page:Cyclopedia of Painting-Armstrong, George D (1908).djvu/409



Alabaster, To Clean. Make a paste with quick-lime and water, spread this well over the discolored article, and leave it on for about twenty-four hours, then remove with soap and water, applying some friction on parts which are worse than others. Alabaster, if not too much discolored, may be cleansed with a strong lye of soap and water, or, the superficial dirt and grease having been removed, it may be washed with diluted muriatic acid.

Glass, To Remove Grease From. Dissolve carbonate of soda in water, in the proportion of 1 of the former to 10 of the latter, and let the liquid boil in a clean untinned iron pot. Slake 8 parts of quick-lime in a covered vessel, and add the hydrate thus formed to the boiling liquid, stirring it meanwhile. Great care must be exercised in using this caustic solution, which must not be allowed to touch the hands, the glass must therefore be dipped in it by the aid of tongs or pliers. When the grease is dissolved the glass is to be well brushed and subsequently rinsed in water.

Gold Size. Heat $1/2$ pound linseed oil in a flask, and gradually add 2 ounces of powdered gum animi, stirring the oil continuously until the whole of the gum is dissolved. Continue boiling until the mixture becomes a little thicker than tar, when it must be strained through a coarse cloth. Previous to use, it is to be ground up with sufficient vermilion to render it opaque, and turpentine must be added in order that it may work freely.

The following method of making gold size is derived from a very old source, and is given in the words of the original: