476 



Transactions. 



The above analyses show that a concentration has taken 

 place. If we change their form slightly they show ns also 

 that the calcium-phosphate is not absolutely insoluble, and 

 that even in the process of concentration some of it has been 

 carried away in solution. In the concentration and solution 

 it is safe to assume that the silica (Si0 2 ) is not carried away 

 nor affected by any chemical action. We are thus enabled 

 to recalculate the analyses on the basis of constant Si0 2 : e.g., 

 if a body (x) contains 1 part per 100 of an unchangeable sub- 

 stance (m), and a quantity of it is partly dissolved away, result- 

 ing in a product (y) which contains 5 parts per 100 of m r then it 

 is clear that the product y results from 5 times its weight of 

 the original x. On recalculating thus from the analyses we 

 find that 186 parts of C 4 have weathered to 29 parts of C 2 , 

 which have differentiated into 14 parts C 3 and 15 parts C 4 . The 

 following table gives the amounts of the constituents of each 

 of these products : — 



