Page:Popular Science Monthly Volume 45.djvu/126

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THE POPULAR SCIENCE MONTHLY.

verdigris with, vinegar and copper—already described by Theophrastus and Dioscorides—of cadmies, impure oxides of lead and zinc, of burned copper (aes ustum), of litharge, of orpiment, of artificial cinnabar, etc. The writer mentions a few alloys, such as bronze, white copper, and gold-colored copper—a subject often treated of by the Greek alchemists, who passed from it to the idea of transmutation. The name of bronze (brundisium) appears for the first time. While its origin has been the subject of controversy among philologists, the accompanying facts given in the text show that bronze was in the beginning an alloy made at Brundisium for the manufacture of the mirrors of which Pliny speaks. The preparation of parchment and of varnish, the fabrication of vegetable colors for the use of painters and illuminators, and their employment on walls, wood, canvas, etc., in encaustic or with isinglass, are the subjects of separate articles.

A group of formulas for gilding follow: gilding of glass, wood, skins, clothing, lead, tin, and iron; and the preparation of golden wires, processes for writing in golden letters (chrysography) on parchment, paper, glass, or marble. Then come silver foil, tin foil, and processes for reducing gold and silver to powder, in which mercury and verdigris were employed—the powder obtained by amalgamation being employed in processes for silvering and gilding. The process has played its part in political economy; for it has been used to assist the passage of gold and silver from one country to another, in spite of the prohibition of the exportation of the precious metals.

The author goes on to say: "We have described everything relative to tinctures and decorations; we have spoken of the substances which are employed in them—stones, minerals, salts, and herbs; we have shown where they are found; whence are got resins, oleoresins, and earths; what are sulphur, black water, salt waters, glue, and all the products of wild and cultivated plants, domestic and marine; beeswax, axunge, all fresh and acid waters; among woods, the pine, fir, juniper, and cypress . . . . acorns and figs. Extracts are made of all these things with a water made of fermented urine and vinegar, mixed with rain water."

These enumerations and descriptions mark the nature of the knowledge sought by the writer, and preserve the trace of ancient treatises on drugs and medicines, similar to those of Dioscorides, but more especially devoted to industry. Unfortunately, we have here hardly else than titles and summary indications, such as would figure in a dyer's scrap-book, placing one after another indications drawn from different authors. Many of the specific names found in the treatise are wanting in the most complete dictionaries. The terms salt, fresh, and acid waters, water formed of fermented urine and vinegar, deserve special notice