100 Scientific Proceedings, Royal Dublin Society. 



The importance of Plattner's scheme, if it be generally applic- 

 able, cannot be exaggerated, for it permits the adoption of our 

 general method of procedure for the qualitative analysis of all 

 minerals, and avoids many of the difficulties attendant upon purely 

 wet methods, such for example as the solution of substances, &c. ; 

 and, owing to its comparative simplicity, it is quite possible to 

 teach the method to students in geology and engineering, who 

 ordinarily cannot afford to devote sufficient time to master purely 

 wet methods of mineral analysis. 



Some time ago one of us framed a complete scheme for the 

 analysis of minerals, based upon Plattner's methods. The substance 

 was to be fused with silver chloride, boras, and sodium carbonate 

 on charcoal in the manner described by Plattner. In cooling 

 the metallic end glass beads were to be carefully detached, one 

 from the other, and separately examined by wet methods in the 

 ordinary way. 



Complex minerals, such as tin pyrites and smaltine, were 

 analysed, as directed in this scheme by Mr. F. 0. Forth, a student 

 in the Faculty of Engineering in the Eoyal College of Science, 

 with excellent results. The following are the results of his 

 analysis of smaltine : — arsenic, bismuth, copper, nickel, cobalt, 

 iron, aluminium, manganese, calcium, magnesium, sodium, sili- 

 ceous matter, hydrosulphuric acid, and phosphoric acid. 



On comparing these results with those of an analysis by the 

 ordinary wet methods, it was found that potassium only had 

 escaped detection. 



When, however, the method was tried with iron and zinc ores, 

 unsatisfactory results were obtained — results which were in some 

 cases not what we had been led to expect from a perusal of 

 Plattner's book — for instance, with the ores mentioned, the glass 

 bead fused fairly easily, but the metallic bead immediately on 

 reduction became quite infusible, and could not be properly 

 separated from the glass. 



Plattner, in describing his process and the results obtainable 

 by it, makes no mention of such action. Egleston, too, in his 

 scheme makes no reference to it.^ 



1 Egleston, in his scheme, confines himself almost exclusively to dry methods. 

 His method of preparing the glass bead is different to that employed by Plattner. 

 He dissolves the substance in a borax bead on platinum wire, and, when saturated, 



