18S5.} M. Berxelius*s Hypothesis of the Atomic Theory. 39& 



manner of considering the compounds, the general law proposed 

 by Berzelius requires that the acid of one ot the salts should be 

 a multiple by a whole number of the acid of the other, which 

 may happen in different ways, but in consequence of the ten- 

 dency of glucina to form salts with excess of acid, the most 

 simple mode is to consider the silica as equally divided between 

 the two bases, which gives us a quadrisilicate of glucina and a 

 bisilicate of alumina. The first of these salts contains 4 atoms 

 of silica and 1 atom of glucina, forming 1 atom of quadrisihcate; 

 the second contains 4 atoms of silica, and 2 atoms of alumina, 

 forming 2 atoms of bisilicate, because all the oxides contain the 

 same number of atoms of oxygen. The composition of the 

 mineral on the first supposition is, 



Quadrisilicate of alumina 86*28 



Glucina 13-72 



100-00 

 And on the second, 



Quadrisilicate of glucina 47-71 



Bisilicate of alumina. .... .......... 52*29 



100-00 

 which are composed of 



Silica 33-99 



Glucina . 13-72 



Sihca 33-99 



Alumina 18-30 



100-00 

 Or, 



Silica \ 67-98 



Glucina 13-72 



Alumina 18-30 



100-00 



'" liCt ns take another example of a quaternary compound as a 

 ^ood specimen of the mode of reasoning adopted in these calcu- 

 lations. 

 The analysis of zoisite gives 



Ox. . Atoms- 

 Alumina 33 = 15-41 w 2 



Silica 43 = 21-62 = 3 



Lime 24 = 6-74 = I 



100 



In this case the silica must be so divided between the twp 

 bases as to form a silicate of alumina containing 2 atoms of 



z2 



