330 THE SCIENTIFIC PAPERS OF 



In the. discussion of the Paper 



"OX SOME RECENT METALLURGICAL PROCESSES," 

 By J. A. PHILLIPS, 



THE Chair was taken by Mr. C. W. SIEMENS,* who in closing 

 said : The process which Mr. Phillips had brought before them was 

 one of many which distinguished the metallurgy of the present 

 day. Ancient methods were always found to be very wasteful, 

 both in fuel and materials, because it never occurred to the ancient 

 metallurgist to separate the silver or gold from the copper, or to 

 make use of the iron as a secondary process. He selected his ore 

 for the one purpose he had in view, whether it was copper, silver, 

 or iron, and used his fuel very wastefully in extracting it. This 

 process was conducted at the expense of the iodide, which had 

 only lately come into use mostly through photography, and at 

 first sight he had been struck by the apparently great expense 

 attaching to it. The discussion, however, had shown that this 

 was really of very little importance, because, though iodine was 

 relatively expensive, the process was so perfect that it was used 

 over and over again. This reminded him of another process 

 lately come into use for the production of soda, where another 

 expensive material, ammonia, was used over and over again to 

 produce carbonate of soda directly from common salt, without the 

 intermediate stages of soda ash, soda cake, and so forth. The 

 question had been asked whether the extraction of silver dete- 

 riorated the value of the copper, and the answer was that it did 

 not, but rather enhanced its value, and he could fully believe that. 

 Lord Palmerston once defined dirt as "matter in the wrong 

 place," and certainly silver in the copper must be reckoned as 

 dirt, and those who dealt with copper as a metallic conductor of 

 electricity regarded it as dirt of a very objectionable character, for 

 a very slight admixture of silver or any other foreign matter in 

 the copper would reduce its conductivity to perhaps one-fourth of 

 the proper amount. There could be no question, therefore, that 



* Excerpt Journal of the Society of Arts, Vol. XXIV. 1875-1876, p. 291. 



