A History of Hindu Chemistry from the Earliest Times to the Middle of the Sixteenth Century A.D. v2.c34.216

v2.c34.216

Preparation of Chemical Compounds.—The knowledge of chemical compounds and of their preparation continued to make progress in the Charaka and Susruta Schools. The great metallurgist, Patañjali, in his treatise on Metallurgy (लोहशास्त्र) gave elaborate directions for many metallurgic and chemical processes specially the preparation of the metallic salts, alloys and amalgams, and the extraction, purification and assaying of metals. Probably it was Patañjali who discovered the use of the mixtures called Vidas, which contained aqua regia or other mineral acids in potentia. Unfortunately Patañjali’s *magnum opus* appears to have been lost, but extracts from it are frequently found in mediæval works on Medicine and Rasáyana, which leave no doubt as to its remarkable scientific value. The metallurgist Nágárjuna, advanced the knowledge of chemical compounds by his preparations of mercury. The Harshacharita, in the seventh century, relates a fable concerning this Nágárjuna, and speaks of him as a friend and contemporary of Sátaváhana. The relative priority of Patañjali and Nágárjuna is a vexed question in the history of metallurgy. That Nágárjuna’s Lohasástra was earlier than the final redaction of Patañjali will appear from the following circumstances :—(1) Chakradatta in his summary of Nágárjuna mentions that the chemical process of testing pure iron must be repeated twice before it can be regarded as decisive, whereas S'ivadása Sen’s extract from Patañjali shows that the latter directed the process to be repeated seven times ; (2) Patañjali in the Abhraka-vidhi (mica operation) adds mercury, which in this particular operation is wanting in Nágárjuna’s recipe (cf. Chakradatta, and Patañjali as reported in the Yogaratnákarasamuchchaya) ; and (3) Nágárjuna is quoted in the earlier compilations, Patañjali in the later.