The Materia Medica of the Hindus, compiled from Sanskrit Medical Works c4.s8.3

c4.s8.3

Cast iron is purified by beating it into thin plates, heating the plates in fire and sprinkling them with cow's urine, sour conjee, oil, and a decoction of the pulse of Dolichos uniflorus (kulattha), seven times in succession. The plates are reduced to powder by pounding them in an iron mortar, rubbing them with cow's urine, and roasting the powder in a covered crucible repeatedly till it is reduced to a fine impalpable powder, that will float on water and will not irritate the eyes when applied to them. It is usual to rub the iron with cow's urine and roast it about a hundred times in succession. In some cases it is recommended that iron should be thus roasted repeatedly for a thousand times. Mandura is purified and prepared for uselike cast iron. Prepared iron is a fine impalpable powder of a reddish grey or brick-dust colour. On chemical analysis it is found to be a mixture of the proto and peroxide of iron. Dose grains six to twelve.