Manufacturer and Builder 1, 1874
Gilding glass can not be patented—every one may do it; but the manner how is subject to a patent. Such is Schwarsenbach's method. He dissolves pure gold in aqua regia, and evaporates till crystallized, in order to free it from the acid. Then it is dissolved in pure water and filtered. The solution must contain 2 grains of metallic gold to the pint of water; add soda till alkaline. Then prepare the reducing solution by saturating alcohol with oliflant gas, and adding an equal volume of pure water. Take two glass plates, and clean them as carefully as a photographer does for a picture; place the cleaned surfaces together at a distance of oneeighth of an inch ill horizontal position, with the largest plate below; mix the two liquids and bring them between the plates, which is readily accomplished by their capillary action; leave them two or three hours, and when they are removed, the gold will be found reduced and deposited on the glass, washed, and varnished. Such is the method patented; but we would suggest to take a single plate well cleaned, placed perfectly horizontal, the edges greased so as to prevent the solution from running off, and then covered with the freshly mixed liquids to the bight of about oneeighth of an inch, in the same way as plated gloss mirrors are now silvered by means of a reducing silver solution.
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