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



Weight in air . . 



grs. 



. 299-6 



Weight in water . 



. 201-9 



Difference . . 



. 97-7 



from which data the specific gravity is 



found to be 



3 ". 6 -3-06. 





977 



Other portions of the stone gave a specific gravity of 3"57. 



From 100 grs. acted on with iodine*, which dissolved out the 

 alloy of iron and nickel, there were obtained of peroxide of iron 

 27*95 grs., and of protoxide of nickel 1'20 gr. 



The portion insoluble in iodine was now acted on with dilute 

 muriatic acid, and gave the following results : — 



Silica . 12-92 



Alumina 015 



Peroxide of ironf . " . . . 9*87 



Carbonate of lime . . . . 0'50 



Pyrophosphate of magnesia. 38*00 



Potash and soda chlorides . 0*45 



Platinochloride of potassium. 0*42 



Oxide of manganese (Mn 3 O 4 ) 0*05 



On treating another 100 grs. of the stone for sulphur, with 

 muriatic acid, and conducting the sulphuretted hydrogen into 

 ammoniacal solution of sulphate of copper so as to form a black 

 precipitate of sulphuret of copper, there were found, by the usual 

 methods, 10*7 grs. of sulphate of barytes. 



There were left, after the treatment with iodine and dilute 

 muriatic acid, 42-1 grs. of mineral insoluble in these reagents. 



From the solution by iodine, and the determination of sulphur 

 as sulphate of barytes, we obtain — 



grs. grs. 



Peroxide of iron . . 27'95 19*57 iron. 



Protoxide of nickel . 1*20 0*94 nickel. 



Sulphate of barytes . 10*70 4*05 protosulphuret of iron. 



Hence we obtain, as our primary analysis of the Dundrum 

 meteoric stone, — 



* This method of investigation was suggested by Mr. William Early, 

 assistant in the laboratory of Trinity College. The process consists in di- 

 gesting the powdered mineral in iodine with water for twelve hours, and 

 proved to be completely successful, as was shown by comparative trials on 

 different portions of the powdered mineral. 



t Present originally as protoxide and protosulphuret of iron. 



