A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v1.c13.s1.17

v1.c13.s1.17

“It is then spread in squares resembling salt pans and sprinkled with water. After about 12 days it consolidates into efflorescing mammillated crystalline plates or crusts called *phitkari-ka-bij* or seed of alum. These crusts are boiled in large iron vessels (luted inside with lime), together with saltpetre (or other potash salt), in the proportion of 15 of ‘alum seed’ to 6 of the latter; when it has settled, the liquor is placed in small earthen vessels somewhat the shape of flower-pots, and crystallization takes place in three days. These crystals are again boiled one or more times to concentrate the solution, which is finally ladled into large thin bladder-shaped earthen *mutkās* or *gharās* with small mouth; these are sunk into the ground to prevent their breaking, and in five days the alum is found crystallized in masses. The vessels are then broken and the alum is stored.