348 Mr. Children's Summary View of [May, 



The sum of all the atoms = 188*, and by the rule of simple 

 propoition,t we find the theoretical composition of the mineral 

 to be per cent. 



Silica 68-09 



Alumina 18-09 



Glucina 13-82 



100-00 

 Analysis of zoisite (p. 339). The atom of lime = 28. 



Atoms. 



^" = 268 = 3 of silica. 



lb 



—^ = 194 = 2 of alumina. 



-^ = 85 = 1 of lime. 



The sum of the atoms therefore = 1 10, and the theoretical 

 composition of zoisite is. 



Silica 43-63 



Alumina 30-90 



Lime , 25-45 



99-98 



It is needless to multiply instances, as any analyses compared 

 in the same way must obviously give the same results. 



Thus we see that all the complicated statements, and still 

 more complicated reasonings, on which they are founded, of 

 which we have given examples in the preceding pages, may be 

 just as well expressed with much greater simplicity, and that 

 the simple statements equally furnish us with a test of the accu- 

 racy of our analyses. Our after reasonings as to the mode in 

 which the elements are severally united in the actual mineral, 

 however probable, can only be conjectural, and we are just as 

 likely to form a correct estimate on the simplest as on the most 

 elaborate system. What good purpose then do these compli- 

 cated statements answer? Do they teach us more accurately the 

 true constitution of mineral substances, or the mode in which 

 their elements are combined ? We cannot perceive how. They 

 do indeed, as we have said of the formulae, give a detailed view 



* Ifi X 8 = 128 

 17 X 2 = 34 

 26 = 26 



188 



t 188 : 128 : 100 : a, and X = 68-09, and so with the other atomi. 



