DETERMINATION OP ALKALIES IN MINERALS. 221 



have been arrived at from more than two years' experience 

 and over a hundred alkali determinations by myself and others 

 made on minerals of the most varied composition. In my 

 laboratory an accurate alkali determination is one of the most 

 simple and speedy analytical processes now conducted, and 

 the presence of magnesia in no degree complicates the result. 

 A little experience will no doubt bring others to the same 

 conclusions. Many singular decompositions of salts have been 

 noticed in the course of these researches; but as they do not 

 bear directly on the object of this article they will be made 

 known on another occasion. 



Many analytical processes mentioned in this article can be 

 applied when operating on soluble silicates, 



