Analysis of Minerals. lyi 



On some applications of Caustic Soda or Potash and 

 Carbon in the qualitative and quantitative Analysis 

 of Minerals. By Charles A. Burghardt, Ph.D. 



{Received March fth, 1890.) 



To those chemists who are brought much into contact 

 with minerals and metallic ores, it has been for a long time a 

 desire that the processes by which such minerals are made 

 available for analysis should be rendered short, accurate, 

 and simple. The minerals I refer to, of course, are those 

 which are insoluble in acids. As is only too well known to 

 chemists, a considerable expenditure of time and much 

 patience is often required before the desired splitting up of 

 the mineral and its solution is arrived at. There are, 

 generally speaking, three kinds of fusing-mixtures or fluxes 

 which the chemist has at his disposal (for it is necessary to 

 fuse the refractory mineral at a high temperature for a long 

 time with one or more of these fusing mixtures), the 

 commonest fusing mixture being one consisting of carbonate 

 of sodium and nitrate of potassium, and most minerals can 

 be eventually split up by its action. Some minerals are 

 only acted upon by being fused with hydrogen potassium 

 sulphate, it sometimes being necessary to split up partially 

 with the first-mentioned fusing mixture, the process being 

 finished by fusing the insoluble still refractory residuum with 

 the hydrogen potassium sulphate. With many minerals 

 these reactions are not complete even after several fusions 

 at a long sustained very high temperature. This entails 

 much labour at the blowpipe-table, and annoyance if the 

 results obtained are not satisfactory. I am aware that many 

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