New Process of Silvering Glass and other Surfaces.

Scientific American 45, 28.7.1849

We learn from our able and most valuable foreign exchange, the "London Patent Journal," that Mr. Thomas Drayton, of Regent street, London, a practical chemist, has recently secured a patent for improvements for silvering glass and other substances. The glass is silvered by causing the silver to be precipitated on the glass and causing it to adhere thereto, without previously coating its surface with any material. First, one ounce of hartshorn or ammonia, two ounces of the nitrate of silver, 3 ounces of water, and 3 ounces of the spirit of wine, are all mixed together and allowed to stand for 3 hours, when it is filtered.

To use this mixture, to every ounce of it add an ounce of saccharine matter, (sugar,) dissolved in half a pint of water and alcohol (half and half) and this is allowed to stand three hours to dissolve. It is then fit to silver glass or other surfaces. The fluid will deposit the silver on the surface of the article, and the glass during the process should be kept at 190° Fahrenheit. This method of silvering is stated by Mr. Diayton, not to emit any unhealthy or disagreeable effluvia, and that it is more durable than the ordinary silvering, not being affected by heat or damp and therefore well adapted to any climate. It is good to give the surface a coat of mastic varnish afterwards. It is stated to be as applicable to the silvering of metals as glass. It is certainly a wonderful discovery and improvement over the old system, or other systems at present in use.

In 1841, we think it was that Mr. Drayton made his first discovery for improvements in silvering glasses. By his first process, he used naphtha, oil of cassia, and a mixture of the oil of cloves. The other ingredients were the some as that described in his new patent with the exception of the sugar. This is a new ingredient, and it seems to answer the purpose of three old ones, which are left out. In 1840, we believe that Dr. Stenhouse first called attention to this subject, by precipitating a pure coat of silver by means of aldehyde, &c. The old quicksilvering process was very unhealthy.

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