1870.] Proceedings of the Asiatic Society. 277 



the method of cwpellation. He explained the principle of this 

 method, what skilP* and experience it required on the part of 

 the operator, and how it still fell short of accuracy in its results. 



Its shortcomings led to the invention of another process by 

 Gay Lussac, known as the volumetric, or humid, method, which is 

 much more accurate, and is now practised very generally on the 

 Continent. Its principles were briefly glanced at. Its introduction, 

 however, into the Indian Mints was not considered desirable by 

 their assay officer, for certain reasons, a few of which were given. 

 The method of cupellation, therefore, being not accurate enough for 

 the purposes of buying and selling bullion, and that by the French 

 process being considered not well suited to Indian Mints, it became 

 necessary to look out for, and introduce into the Mints of this 

 country, a process more likely to answer all the ends in view. 



This object was attained by the adaptation and introduction of 

 the process now in use, viz., the " Chloride process of assaying sil- 

 ver." Hitherto it had never been resorted to, except on a very 

 small scale. Assayers appear to have shrunk from the manifest 

 difficulties of manipulation in collecting, drying, and weighing the 

 precipitated chloride of silver. The credit is due to Mr. James 

 Dodd, a former Assay Master of the Calcutta Mint, of having so 

 simplified, modified, and systematized the details of this method, 

 as to render its application to the assaying of silver on a large 

 scale easy and accurate. The principles and an outline of the 

 details of the process were then given, an understanding of some 

 of the chief appliances and steps in the manipulations being as- 

 sisted to by suitable photographs. The system of weights in use 

 and the quantity of the sample taken for assay were also explained, 

 as well as the points wherein this system might fairly be considered 

 better suited to a Mint in India than the other methods. 



In conclusion, Dr. B. alluded to the vast amount of silver bullion 

 which this process enabled the assay officers of the Indian Mints 

 to deal with confidently and accurately, during the past 15 years. 

 In one year alone, that of 1865-66, the importation of silver bullion 

 reached to the immense amount of over 14 millions sterling, — so put- 

 ting to a crucial test the system of assay used for its valuation. 



