The treatise called Chakradatta-sangraha, describes in detail the treatment of diseases arranged in the order in which they are described in the Nidána of Mádhava Kara, and to which it is a companion volume. Its author deals chiefly with vegetable drugs. He gives a few prescriptions containing mercury, in which this metal is mixed with sulphur and vegetable substances, but the preparations of mercury produced by sublimation and chemical combination with salts, etc., were unknown to him. It would appear, therefore, that mercury was just coming into use in his time. He does not mention opium, so that his work, and consequently the Nidána, must have been composed before the introduction of this drug into India by the Mussulmans.
The last great work on Hindu Medicine is that called the Bhávaprakása, compiled by Bhava Misra. It is a comprehensive treatise, compiled from the works of preceding authors, with much additional information on the properties of drugs, accounts of new drugs, and of some new diseases, as for example the syphilis introduced into India by the Portugeese and described in this work under the name of Phiringi-roga. By the time this work was composed, opium had been largely employed in practice, the use of mercury had extended to almost all diseases, various preparations of gold, silver, tin, copper, orpiment, arsenic, etc., had come into fashion, superseding to a considerable extent the vegetable drugs of the older writers; in short Hindu pathology and therapeutics had reached their acme. Dr. Wise says that the Bhávaprakasa was composed about three hundred years ago. It cannot, at any rate, be a much older work. China root, called Chob-chini in the vernacular, is described in it. According to Fluckiger and Hanbury the use of this drug as a remedy for syphilis was made known to the Portugueese at Goa by Chinese traders, about (A. D. 1535). Hence the Bhávaprakasa must have been compiled after this period.
Besides the systematic treatises on the description and treatment of diseases above noticed, there are several works in Sanskrit devoted especially to the description of the synonyms and properties of individual medicines and articles of diet. The oldest treatise on this subject is the one called Rajanirghantu. It is generally
