890 Intelligence and Miscellaneous Articles, 



dehydrates the nitric acid so as to render it less stable and more fit 

 to give up its oxygen. The nitric acid employed in batteries becomes 

 too weak for use when it has reached a certain state of dilution ; by 

 means of sulphuric acid the last atom of actual nitric acid may be 

 made use of. Sulphuric acid can readily dehydrate about its volume 

 of nitric acid, added to it in small quantities as required. It is to 

 be observed that this sulphuric acid is not lost ; it may be employed 

 for the solution of the zinc of the pile, taking care to boil it for a 

 few moments so as to drive off any portions of nitric acid, the pre- 

 sence of which might dissolve the mercury and destroy the amalga- 

 mation. — Comptes Rendus, August 29, 1853, p. 355. 



ANALYSIS OF AURIFEROUS QUARTZ. BY A. B. NORTHCOTE, 

 ASSISTANT AT THE ROYAL COLLEGE OF CHEMISTRY. 



The specimen, the analysis of which is detailed below, was con- 

 signed to England by an Australian merchant among many other 

 pieces which came to him in the way of business, and nothing unfor- 

 tunately is therefore known respecting its origin. 



Its aspect was decidedly waterworn, and as regarded the quantity 

 of precious metal present, not at the first glance very promising. 

 Quartz was the predominating feature, with small nodular masses of 

 gold dispersed here and there over the surface. On breaking the 

 lump, however, a very different appearance presented itself ; these 

 masses were found to extend inwards, and, assuming the character 

 of veins, to run rather extensively throughout the mineral ; and so 

 much richer did it prove than was expected, that the gold separated 

 constituted about half the weight of the original specimen. The 

 whole of the gold existing in it was contained in these large veins, 

 there being no finely divided particles disseminated through the sub- 

 stance of the associated bodies. 



The matrix consisted almost entirely of quartz, with a little car- 

 bonate of lime and a trace of alumina ; but probably the true matrix 

 was quartz alone, the other matters being merely lodgements in the 

 crevices of the rock, — impurities contracted at some period subse- 

 quent to its formation. 



The analysis of the contained metal, conducted in the ordinary 

 way, the gold being reduced by means of oxalic acid, gave the fol- 

 lowing result in 100 parts : — 



Gold 99*283 



Silver -437 



Iron -203 



Copper -069 



Bismuth '008 



100-000 



