Mechanical Assay of Quartz. 139' 



Art. XLVI. — On Siemens Universal Galvanometer for 

 testing Telegraijliic Lines. 



By R. L. J. Ellery, Esq. 



[Contributed 12th August, 1872.] 



The President exhibited a Siemens Universal Galvano- 

 meter, and gave an oral description of its use and the 

 method of testing with it telegraphic lines. 



Art. XLVII. — Notes on the Mechanical Assay of 

 Quartz. By G. Foord, Esq. 



[Read 9tli September, 1872.] 



The brief note, concerning the mechanical assay of quartz, 

 which I am now prepared to read, was entered in our 

 Secretary's list as part of the business of the Society's last 

 general meeting. It was intended to fulfil a requirement 

 which similar brief explanations of mine have on former 

 occasions fuUilled : namely, to come in, after the regular 

 paper of the evening had been read and discussed, as a 

 supplement, extending the proceedings of an otherwise short 

 evening to a suitable length. The course of events, how- 

 ever, gave occasion for its postponement, and now, to 

 prevent undue expectations and consequent disappointment, 

 I think it best to explain, at the outset, that I cannot claim 

 a very great importance or novelty for what I have to 

 advance, nor can I say that I have devoted any amount of 

 workmanship to the notes themselves, now offered to your 

 notice. On the other hand, I feel some confidence in making 

 a statement concerning the assay of quartz for gold, because 

 it is a subject which has engaged my particular attention. 

 Moreover, I trust that the point which I am about to 

 urge, is one of practical significance, which it would be 

 useful to promulgate ; and, although the facts themselves 

 may be familiar enough to the metallurgist, it seems to me 

 that they may yet possess a degree of novelty to some at 

 least of the members whom I meet here this evening. In 

 this light, I ask you, Mr. Pi'esident and gentlemen, to receive 

 what I have to say, as a mere brief note,' embodying 

 a point of useful application. 



The assay of auriferous quartz is the key to the extraction 

 of the precious metal on the great scale ; and there are two 



