A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c13.31

v1.c13.31

“Deribo.—The mine is situated on a sharp anticlinal bend in a thin band of black slates intercalated in the Alwar quartzites. There appears to be no true lode; the one, which is pyrites mixed with arsenical iron, occurs irregularly disseminated through the black slates, a few specks and stains only being seen in the quartzites; occasionally rich nests of ore were met with . . . . . From an interesting account by Major Cadell, the following facts regarding the manufacture have been extracted. The ore, as usual in the native process, is pounded, made up into balls with cow-dung, roasted, and then smelted in a closed furnace and refined in an open charcoal fire. Thirty pounds of ore require four times that quantity of charcoal and yield 5½ pounds of metal, or 16.6 per cent. During the last 12 years the average annual outturn has been only 3 tons 8 cwts., and it is diminishing owing to the influx of European copper.