The Rev. S. Haughton's Notes on Mineralogy. 265 



the soluble mineral of the meteorite to be Chrysolith, having the 

 formula 



3RO,Si0 3 , 



in which RO denotes protoxide of iron and magnesia. 



The 42*10 grs. of mineral insoluble in muriatic acid were di- 

 vided into equal parts, of which one was fluxed with carbonate of 

 soda, and the other with lime and chloride of ammonium, with 

 the following results : — 



grs. 



Silica 12-45 



Alumina 0*35 



Peroxide of iron 1*64 



Oxide of manganese (Mn 3 O 4 ) . 0'16 

 Peroxide of chrome (Cr 2 O 3 ) . 051 

 Carbonate of lime .... 1*45 

 Pyrophosphate of magnesia . 12 '45 

 Potash and soda chlorides . . O80 

 Platinochloride of potassium . 0*90 



Assuming the chromium to be present as chrome-iron, and 

 making the necessary reductions in the other elements, we find — 



grs. 



Original weight . . . 21*05 

 Chrome-iron .... 0'75 



Insoluble mineral . . . 2030 



3. Insoluble Mineral. 



grs. Per cent. Oxygen. 



Silica ' 12-45 61-33 31-842 



Alumina 0'35 1'72 0803 



Protoxide of iron . . 1-23 6-06 1-344^ 



Protoxide of manganese. 0-16 0*78 0-174 j 



Lime 0*81 3'99 1-133 I , , Q4 „ 



Magnesia. . . . . 4-47 22'02 8-800 f 11 J ^ 



Soda 0-28 1-38 0-352 | 



Potash 0-17 0-83 0*140 J 



Loss 0-38 1-89 



20-30 100-00 



It is not possible to form any opinion as to the mineral com- 

 position of the insoluble portion of the meteorite, as it is doubt- 

 less composed of more than one unknown mineral substance. 



If we collect into one view the preceding results, taking a 

 mean of all, we obtain the following view of the mineralogical 

 composition of the Dundrum meteorite : — 



