Vol. VI, No. 8.] Aurvedic Metallic Preparations. 387 



[N.S.] 



Methods of Preparation by Modern Aurvedic Physicians. 



As most Aurvedic physicians prepare their own medicines, 

 the methods of preparing the same medicine vary considerably. 

 So far as we have been able to collect information, there are 

 three different methods of preparing "lauhas. *' 



(1) Some physicians procure the best kind of iron, heat 

 it in a blacksmith's forge and take the rust formed on the sur- 

 face of the iron. 



(2) Others keep steel immersed in cow's urine for years 

 together and take the rust collected on the surface. 



(3) While some are reported to prepare their "lauhas ' ' 



by repeatedly heating powdered ferrous sulphate ( ^ftrara ). 



Of course the method given in Rasendra-shar-Shangraha is 

 followed by many orthodox physicians. In the methods Nos. 

 (1) and (2) the rusts obtained are purified in the usual way and 

 then formed into balls with cow's urine or a decoction of the 

 " three myrobalans." dried in the sun and calcined in the pit 

 by means of burning cow-dung cakes in the usual way. The 

 balling, powdering and calcining in an enclosed space are 

 repeated ten, hundred or thousand times. 



Experimental. 



We collected " lauhas' ' which have undergone different 

 number of " putas." The colour of these samples varied from 

 greyish black and grey to rouge red. It was observed that one 

 1 ' puta lauha ' ' was greatly attracted by a magnet, "lauha" 

 which has been calcined ten times was attracted to a less 

 degree, while samples of seventy-eight "puta lauha' ' were 

 very slightly attracted. As regards iron which has been 

 calcined hundred or thousand times, it was not in the least 

 attracted by a magnet. The magnetic character of the samples 

 which have undergone a smaller number of "putas " suggested 

 to us the possibility of the presence of free iron in them. The 

 oxides of iron, both ferrous and ferric, were also present. As 

 we were not acquainted with any method by means of which 

 free iron could be quantitatively determined in presence of 

 ferrous and ferric oxides, we tried the following method which 

 was found to be fairly satisfactory : 



Method of estimating Free Iron in the presence of Ferrous ami 



Ferric Salts. 



determined 



acid 



hydrogen evolved when actc K 



in an atmosphere of carbon dioxide. The total ferrous iron 



uan 



tity of ferrous salt present is determined by titration with 



