338 SeyberCs Ajialysis of the Maclureite. 



From the above analysis wc have the following result :- 

 Per 100 Parts. 



A. Water, - 01.000 containing oxygen 



B. Silica, - 30.333 - - - 15.257 



C. Peroxide of Iron, 01. 666 - - - 00.510 

 E. Maenesia. 56.666 - - - 21.935 



89.665 

 100.000 



10.335 Lo?s. 



Analysis, [No. 2.) 



The great deficiency in the above results, in regard to 

 the 100 parts of mineral employed, rendered it highly prob- 

 able that an alcali was an essential constituent of this sub- 

 stance. The analysis was then repeated in the following 

 manner : 



A. Three grammes of (he mineral were finely pulveri- 

 zed and exposed to a red heat ; the colour of the powder 

 was not materially altered ; the weight, after calcination, 

 was 2.98 grammes, therefore the moisture volatalized, by 

 calcination, was 0.02 grammes on 3 grammes, or 0.666 

 per 100. 



B. The residue of the calcination, (A) was treated as in 

 the preceding analysis, the silica, separated by filtration, 

 after exposure to a red heat, weighed 0.93 grammes on 3 

 grammes, or 31.0 per 100. The interior of (he crucible 

 again presented appearances similar to those stated in the 

 first analysis. 



C. The peroxide of iron obtained from the liquor (B,) 

 by the hydro-sulphat of ammonia, weighed 0.09 grammes 

 or 3 grammes, or 3.0 per 100. 



D. The liquor (C,) was treated with an excess of lime 

 water, the precipitate produced was very abundant; after 

 being perfectly edulcorated and strongly calcined, it gave 

 1.68 grammes of magnesia on 3 grammes, or 56.00 per 

 100. 



E. The liquor (D,) which was very voluminous, was con- 

 centrated by evaporation, and the lime was precipitated by 

 oxalate of ammonia : the liqiior was then filtered, and evap- 



