Nitre was unknown to the ancient Hindus. There is no recognized name for it in Sanskrit. The Bhάvaprakάsa mentions Suvarchikά as a variety of sarjikά or barilla, and gives sora as its vernacular equivalent. But suvarchika, according to standard lexicons, is a synonym of sarjikά and not a separate article. Some recent Sanskrit formulae for the preparation of mineral acids con-taing nitre, mention this salt under the name of Soraka. This word however is not met with in any Sanskrit dictionary and is evident-ly Sanskritized from the vernacular sora a term of foreign origin. The manufacture of nitre was therefore most probably introduced into India after the adoption of gunpowder as an implement of warfare. It is necessary to observe here that many writers have erroneously translated nitre into the Sanskrit term yavakshάra. This last however is not a nitrate but an impure carbonate of potash obtained by reduciug to ashes the spikes of the barley.

Chloride of ammonium is not mentioned by Susruta and the older writers. In recent Sanskrit works it is called narasara, a term apparently derived from the vernacular nausadar of Persian oirgin. Another salt mentioned in recent Sanskrit compilations is the impure sulphate of soda called Khάrinoon in the vernacular. It is called Kshάri lavana in Sanskrit, and is used in combination with other saline medicines.