Page:A Short History of Aryan Medical Science.djvu/124

116 The therapeutic effect of a medicinal agent is regulated, not by the nature of its inherent taste, but by that of the taste of its Vipaka.

5. (inherent nature) is the peculiar active force residing in a drug. There are certain drugs whose taste, property, power, and consequence of action are analogous, and yet the effects produced by them are quite dissimilar. For example, Madhusrava (Bassia latifolia) and Draksha (Vitis vinifera) are similar in taste, both being sweet ; similar in property, both being heavy ; similar in power, both being cold ; and similar in consequence of gastric action, both remaining sweet in their Vipaka, and yet the physiological effect of the former is costive and that of the latter laxative. This inherent peculiarity of the drugs is called their Prabhava. In like manner, Chitraka (Plumbago zeylanica) and Danti (Croton polyandrum) are both pungent to taste, light in property, hot in power, and pungent in consequence of gastric action. But Chitraka promotes digestion, while Danti operates as a powerful purgative. Certain substances show their Prabhava independently of the four conditions emunerated above. For instance, a herb called Sahadevi (Vernonia