6. Agada — Antidotes for poisons — mineral, vegetable, and animal.
7. Rasayana — Treats of medicines preserving vigour, restoring youth, improving memory, and curing and preventing diseases in general.
8. Vajikarana — Describes the means of increasing the virile power by giving tone to the weakened organs of generation.
Brahma taught Ayur Veda to Dakshprajapati, who in turn expounded it to Ashvini Kumars, "the twin sons of the Sun." The twin brothers wrote important works on medicine and surgery, and were the divine physicians. Many hymns in the Rig Veda are addressed to these twin gods, from which it appears that medicine and surgery were fully appreciated by the ancients, and held in high esteem by them. Some of the wonderful operations performed by them are also recorded. A legend in the Rig Veda thus describes their skill : A certain sage named Dadhyanchi had learnt the science of Brahma-vidya from Indra under an interdiction not to teach it to any one else, the preceptor threatening to cut off his pupil's head in case of any infringement of the compact. The Ashvins, anxious to learn the
