114 THE POPULAR SCIENCE MONTHLY. 



verdigris with vinegar and copper already described by Theo- 

 phrastus 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) ap- 

 pears 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 fabri- 

 cation 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 (chrysogra- 

 phy) 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 ob- 

 tained by amalgamation being employed in processes for silvering 

 and gilding. The process has played its part in political econ- 

 omy ; 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 sub- 

 stances 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 

 ferirented 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 



