356 PROCEEDTNaS OF THE ACADEMY OP [1886. 



the loss by ignition is owing to CO^ and not to water, its equiva- 

 lent of CaO was subtracted. Tlius corrected the composition of 



60 = 0-5120 ) 



80 = 0-0560 j ^'^^^ 

 144 =0-0230^ 

 160 = 0-1420 >0-187 



56 = 0-5730 

 40 = 0070 



0-580 



99-47 

 This gives the ratio 



(Si, Ti)0^ : (Fe, Ti, A1)^0' : (Ca, Mg)0^ 

 3-03 : 1 : 3-102 



quite satisfactory to the formula of Garnet 



Ca'(Fe, Al)^ Si^O^^ 



The greenish yellow matrix shows under the microscope an 

 intimate mixture of three minerals, one of which is Calcite, one 

 a green and one a white Silicate. Its composition is given with- 

 out at present expressing an opinion as to its mineral nature. 



Spec. Gr. 3-137 



98-18 



A specimen of Schorlomite from Arkansas was analyzed with 



great care to test the hypothesis that Schorlomite is simply a 



titanium Melanite. The material was like anthracite in lustre 



and color, quite opaque, even in thinnest sections. It decomposes 



