A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c13.s1.12

v1.c13.s1.12

“Rājputana, Khetri, and Singhana.—In connection with the copper mines at the above localities there are manufactories which turn out considerable quantities of blue vitriol (copper sulphate), copperas (iron sulphate), and alum. The process has been very fully described and illustrated by Colonel Brooke. In 1864 there were twenty of these factories at Khetri and about double the number at Singhana. The broken shale from the mine which contains the salts is placed in earthen *gharas*, together with the crusts from the refuse heaps of previous lixiviations and water is added. The *gharas* are arranged on ledges prepared for the purpose on the heaps of refuse, as will be seen by reference to the wood-cut (*vide illustrations*).