24 SANSKRIT MATERIA MEPKA. 



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of soda; Sarvaksln'ra, mixed ashes of several plants ; Narasdra, 

 chloride of ammonium ; Soraka, nitrate of potash, and Tavkana, 

 borax. The term Ushara, is applied to saline earth. 



Metals and metallic compounds are subjested to a so-called 

 process of purification in order to get rid of their impurities or 

 deleterious qualities. If used in an unpurified state, they are suppo- 

 sed to induce certain diseases or morbid symptoms. The metals, 

 for the most part, are purified by repeatedly heating their plates 

 and plunging them in the following fluids, namely, oil, whey, sour 

 conjee, cow's urine and the decoction of a pulse called kulattha 

 (D oliclios uniflorus) . Another method o£ purification consists in soak- 

 ing the plates of heated metals in the juice of the plantain-tree. 



Metals and metallic compounds are reduced to powder by 



various processes. The operation is called mdrana, which literally 



means killing or destruction of metallic character but practically a 



reduction to powder, either in the metallic state, or after conversion 



into an oxide or a sulphide. Various processes for the calcination 



of different metals are described in Sanskrit works on the subject. 



I will not burden these pages with a detailed account of tl 



but shall only describe modes of preparation followed at the 

 present day. 



Although the Hindus had made some successful efforts in 

 preparing a certain number of chemical compounds such as per- 

 nhloride of mercury, sulphides of copper and silver, oxide of tin, 

 some acids, alkalies, etc., yet their chemical operations were of a 

 very rude and primitive character. The apparatus employed by 

 them consisted of [crucibles of different sorts, glass bottles and 

 earthen pots arranged for sublimation of volatile compounds, retorts 

 for distillation, sand and vapour baths, etc. The furnace for heat- 

 ing metals is usually a pit in the ground called nm^Z Gqjaputa. 

 It is made one and a quarter cubits in depth, length and breadth. 

 This is filled with dried balls of dbwdung. The metals or metallic 

 compounds to be roasted are enclosed in a covered crucible and 

 placed in the centre of the pit within the balls of cowdung, which 

 are then set fire to and allowed to burn till consumed to ashes. 



ij*TTO MwMytmtra or crucibles, are recommended to be 

 made of husks of rice two parts, earth from ant, hills, iron rust, 

 chalk and human hair cut into small bits, one part each, These 



