34 Identity of Pyrochlore with Microlite. 



stores the brown color again ; these changes constitute a distinc- 

 tive character. With borax on a platina wire, the mineral fuses 

 with slight effervescence, the outer flame gives a glass which 

 while hot is reddish brown, but becomes pale yellow as it cools ; 

 the globule in the reducing flame remains clear, and when cold 

 is of a pale green color, when flamed a white enamel is produced. 

 The darkest colored fragments give a yellowish enamel, but the 

 reducing flame gives as before a light green glass. With a par- 

 ticle of oxide of iron the borax globule in the reducing flame 

 gives the characteristic reactions of ferruginous titanic acid. 



Phosphoric salt gives in the outer flame a reddish yellow glass 

 whilst hot, which becomes green on cooling; the reducing flame 

 gives a clear fine green glass. Tin does not develope the color 

 of titanic oxide. Soda does not show the presence of manga- 

 nese, but the mineral gives a deep green color to the fused mass 

 while hot, which becomes yellowish brown on cooling. One 

 grain of the mineral which had been dried was decomposed, the 

 titanic acid carefully separated and dried, it weighed 80 ; this 

 had the chemical characters of pure titanic acid. 



The solution of the oxides from the titanic acid gave a precip- 

 itate of sulphate of tin, when treated with sulpho-hydric acid, 

 and the sulphate oxidized before the blowpipe gave with soda a 

 globule of tin. Sulpho-hydrate of ammonia gave a black pre- 

 cipitate, which when roasted contained oxides of iron and ura- 

 nium, with traces of oxide of cerium. The fluid remaining gave 

 with oxalate of ammonia, a precipitate which was converted into 

 sulphate of lime, equivalent to O.OS lime. Thus, 



Titanic acid, 80. 



Oxide of tin, "^ 



i^*^"' I . . . . 11.8 



cermm, [ 



uranium, J 

 Lime, 08.2 



100.0 



This mineral is therefore identical with that analyzed by Woh- 

 ler. The absence of protoxide of manganese and water, and the 

 smaller proportion of oxide of iron in this specimen, as indicated 

 by the blowpipe experiments, w^ill account for the larger propor- 

 tion of titanic acid given in the analysis. 



