268 The Rev. S. Haughton's Notes on Mineralogy. 

 Adding together the oxygen of the protoxides, we find — 



RO . . . 19-537 



SiO 3 . : . 20-637" 



}■ 



A1 2 3 . . 0-135/ ; 



From the preceding result, it is evident that the soluble mineral 

 in this meteorite is Chrysolith, or the silicate of magnesia and 

 iron represented by the formula 



3RO, SiO 3 , 

 in which magnesia preponderates greatly over the iron. 



The 38*3 grs. of mineral insoluble in muriatic acid and in 

 carbonate of soda were now divided into two equal portions, of 

 which one was fluxed with carbonates of soda and potash, and the 

 other with lime and chloride of ammonium, with the following- 

 results : — 



grs. 



Silica 10-85 



Alumina 0'23 



Peroxide of iron . . . . . . 2'51 



Oxide of manganese (Mn 3 O 4 ) . 0-30 

 Oxide of chrome (Cr 2 O 3 ) . . . 1*42 



Carbonate of lime none 



Pyrophosphate of magnesia . . 11-50 

 Potash and soda chlorides . . . 0*30 

 Platinochloride of potassium . . 0*50 

 Assuming the chrome to be present as chrome-iron, 

 FeO,Cr 2 3 , 

 we find grs. 



Original weight . . . 19*15 

 Chrome-iron .... 2"08 



Earthy insoluble . . \ 17*07 

 If we now omit the chrome-iron and make the necessary re- 

 ductions in the foregoing results, we obtain — 



3. Earthy Mineral {insoluble). 



grs. Per cent. Oxygen. 



Silica 10-85 63-56 33*000 



Alumina 0'23 1-34 0-525 



Protoxide of iron . . . 1-60 9*37 2*078 



Protoxide of manganese . 0*30 1*75 0*392 



Lime none 



Magnesia ..... 4*13 24-19 9*666 



Soda 008 0*47 0*119 



Potash 0-09 0-52 0087 



[Gain] [0-21 ] [1*20 ] 



17*07 100*00 45*867 



