1886.] NATURAL SCIENCES OF PHILADELPHIA. 35T 



readily with HCL. Tlie reduced permanganate was calculated as 

 Ti^O^. 



Spec. Gr. = 3-876 at 23C. 



Si02 = 25-80 : 60 = 0-430 "I ^.^gg 

 Ti02 = 12-46 : 80 = 0-156 j 

 Ti203= 4-44:144 = 0-031^ 

 AP03= 1-00 : 103 = 0-009 > 0-185 

 Fe^O^ 23-20 : 160 = 0-145 j 

 CaO =31-40 : 56 = 0-561^ 

 MgO = 1-22 : 40 = 0-030 V 0-597 

 MnO = 0-46 : 11 =0-006) 



99-98 

 This gives the ratio 



(Si, Ti)02 : (Fe, Ti, Al)203 : (Ca, Mg, Mn)0 

 3-16 1 : 3-22 



While not so near to the normal ratio, it is near enough, espe- 

 cially considering the difficulty of estimating Ti'O^, in warranting 

 the hypothesis that Schorlomite has the formula of garnet, is 

 isomorphous with it, and exists, as the writer hopes to establish, 

 in a complete series of intermediate members; so much so, that 

 it will be impossible to say where Melanite stops and Schorlomite 

 begins, even though every titanium Melanite be not called Schor- 

 lomite. 



