Page:A Short History of Aryan Medical Science.djvu/122

114 and vice versa, or otherwise the result would be disastrous. The general belief of the Hindoos in the hot and cold inherent qualities of medicines is fully shared by the Greek physician Galen, who teaches that, if a disease be hot or cold, a medicine with the opposite qualities is to be prescribed.

4. (consequence of action) is the change which a medicine undergoes in the organism under the influence of the internal heat. When a substance in the stomach is brought into contact with the digestive fire it is decomposed, and is sometimes recognisable in another form, with its medicinal activity greatly modified by the chemical changes that affect it. This converted state of the substance is called its Vipaka. The chemical effect on the six kinds of tastes is either sweet, sour, or pungent. The Vipaka of sweet, sour, and pungent agents remains unaltered as a general rule ; that of a saline substance becomes sweet ; and of astringent and bitter, pungent. To this (as to most other rules) there are exceptions. Rice, for instance, is sweet, but by the influence of the bodily temperature within, it turns sour. Chebulic myrobalans have an astringent taste, but by chemical action in the organism they become