SULPHATE OF COPPER.
This substance is also known by the names, “Blue Vitriol” and “Blue Stone.” It is a combination of sulphuric acid with oxide of copper, and may be made by uniting those substances; but what is used on a large scale for commercial purposes is obtained from the waters which flow into copper mines where “copper pyrites” abound; this water is evaporated, and the sulphate of copper crystallizes. Sulphate of copper has of late been in great demand for the electro-deposition of copper.