599 



(1) (2) (3) 



Silex . 56.921 1.224 21.10 



Alumina and trace of Oxide 



of Chrome 2.980 0.058 1.00 



Magnesia 22.275 1.076 S 



Water 1.625 0.180 3.10 



Loss 2.049 



100.000 



From the numbers in columns (2) and (3), which, calcu- 

 lated in the ordinary manner, represent the relative numbers 

 of atoms of the various constituents, it is obvious that the 

 empirical formula of this mineral is 



21 SiOa + AC2O3 + 27 [^^^ + 3 HO. 



Novir, these atoms may be grouped so as to form a tersilicate 

 of alumina, and a subsesquisilicate of lime and magnesia ; so 

 that the following may be considered as the rational formula 

 of Chinese jade : 



Aca 03,3 Si 03+9(3 (ca^o'^^'^O "*" ^"^* 

 In looking into works on mineralogy, I find that nephrite 

 or jade has already been at least twice analysed, first, by 

 Saussure, and secondly by Kastner; and, from the account 

 given by Beudant, of the specimen examined by the latter, 

 it would appear to be the Chinese variety. The result, 

 however, obtained by these chemists are quite irreconcileable 

 with each other, and with mine. Thus, Saussure found his 

 specimen to contain 3 per cent, less silex than I have de- 

 tected in mine, to include no magnesia, but instead thereof, 

 the oxides of iron and manganese, and about 20 per cent, of 

 mixed soda and potash. Kastner obtained 6 per cent, less 

 silex, about 7 per cent, more alumina, and 8 per cent, more 



VOL. IT. 3 D 



