Page:A History of Hindu Chemistry Vol 1.djvu/199

Rh the Susruta a crude and imperfect, but all the same potentially modern, process for the preparation of the metallic salts. The much reputed "potable gold" in the shape of the chloride of the metal was probably in this way obtained. It will be interesting to note the successive stages in the evolution of the chemical processes as we proceed. (See below especially under "Chemistry in Rasārnava," where the mixture of the salts is technically named "vida" and consists of green vitriol, alum, common salt, salt-petre, &c.).

The reader will find an analogy in the ancient Egyptian and Greek methods as preserved in the Leyden Parchment, one or two extracts from which cannot fail to be of interest. It may be added by way of explanation that mineral acids being unknown to the ancients they had often to take recourse to the roundabout way of heating metals in combination with a mixture of blue vitriol, copperas, common salt and so on (see under "Mineral Acids") in order to get their salts.

"Ayant pris quatre paillettes d'or, faites-en une lame, chauffez-la et trempez-la dans de la couperose broyée avec de l'eau et avec une autre (couperose) sèche, battez (une partie)...une autre avec la matière mélangée: déversez la rouille et jetez dans..."