Analysis of Minerals. 177 



sulphuric acid had taken place. On testing the acidified 

 solution sulphuric acid was detected in large amount, con- 

 sequently sodium sulphate had been found. 



Simple silicates such as kaolin (china-clay), talc, cyanite, 

 &c, and double silicates such as tourmaline, hornblende, 

 garnet, &c, are split up and rendered soluble just as easily 

 as any of the other minerals mentioned above. I hope at 

 some future time to lay before the Society a more extended 

 series of analyses of metallic ores and silicates, also of some 

 minerals containing fluorine, by the new method, and in 

 concluding this communication I must express my thanks 

 to my young assistant, Mr. Gilbert Rigg, who has carried out 

 my instructions with great intelligence and enthusiasm. 



