SAND, OR SILEX.
In the manufacture of glass it is essential that the silex should be perfectly pure, as the slightest mineral taint affects the color.
At first the New England factories got their sand from Demerara, brought as ballast, and the quality was good. During the War of 1812 this source of supply was cut off, but Plymouth beach provided for the wants of the manufacturers, until a better sand was discovered at Morris River, N.J., though not up to the full requirement of the art. For ten years past, Berkshire County. Mass., has furnished sand; the best quality is owned by G. W. Gordon, Esq. By thorough washing, and passing it through fine sieves, and proper packing, he now commands the market, and delivers it ready for use. The purity has been tested, as shown by the following extract from a report by Professor A. A. Hayes, M.D., of Boston, Massachusetts State Assayer, of the result of analyses of three samples of Berkshire sand, taken from three different locations owned by Mr. Gordon, viz.:—
"For the manufacture of glass, the slight amount of earth, in mica and tourmaline, contained in these samples, is of no account, the impurity being such oxides as color glass. The analyses therefore give only the proportion of coloring oxides; and, for simplicity of statement, the total weight of coloring oxide in each sample is determined in one part or pound.
| "Sample B analyses: | 4000 parts of this sample contain one part of oxide of iron. |
| Sample C analyses: | 3333 parts of this sample contain one part of oxide of iron. |
| Sample P analyses: | 3460 parts of this sample contain one part of oxide of iron. |
"Sample B is equal in purity to the best sand known as a material for glass, in this or any other country."