174 AC1DIFIABLE COMBUSTIBLES. 



Silica 53J; 

 Lime 48-96 



Strom eyer's gives us 



Silica 53J 

 Lime 49'153 



Rose's gives us 



Silica 53^ 

 Lime 47-969 



BonsdorfFs gives us 



Silica 53 

 Lime 45-086 



In the three first analyses there is an excess 

 of lime ; because the mineral analyzed was found 

 in a limestone rock ; in the last analysis by Bons- 

 dorff, there is an excess of silica, because the 

 table spar was from a horneblende rock. If we 

 take a mean of all these analyses as likely to fur- 

 nish a near approximation to the true composi- 

 tion of table spar, we obtain 



Silica 53-333 or 3-905 

 Lime 47-792 3-5 



It is obvious that this mean cannot be correct, 

 because three of the specimens examined came 

 from a limestone rock, and therefore were likely 

 to contain an excess of lime, and only one from 

 a horneblende rock, and likely to contain an ex- 

 cess of silica. However, we see that even from 

 this mean, we get 3-908 for the weight of two 

 atoms of silica, or 1-9525 for the weight of one 

 atom. 



16 



