RESULTS FROM RECx\LCULATlON OF ANALYSES. 



855 



was retained by the residual clay, have arrived at very interesting, though 

 not absolutely accurate results ; this for the reason that alumina is not 

 wholly insoluble in meteoric waters. Indeed, in many instances which 

 might be cited, the iron oxides are apparently more refractory than 

 the alumina, as will be noted later. By a comparison of the analyses of 

 fresh and decomposed rock it is, however, evident that in this particular 

 case the alumina has remained most nearly constant. Recalculating, 

 then, the matter in columns 1 and 2 on the basis of 100 and considering 

 the alumina as a constant factor, we get the results given in columns 8, 

 9 and 10, the last representing, so far as it can be obtained by this method, 

 the actual percentage loss of materials attending the breaking down or 

 degeneration, as we may well call it.* 



Calculated Loss of Material. 





8 



9 



10 



11 



12 



Constituents. 



Recalculated on basis 

 of 100. 



m . 





 ^ 



(D 1—1 



a; 



-t-> .iH 



u 







Fresh 

 diabase. 



Decomposed 

 diabase. 





SiOa 



47.01 

 20.11 

 3.63 

 8.83 

 7.06 

 3.15 

 0.77 

 2.14 

 3.91 

 0.68 

 2.71 



44.51 

 23.24 



1 12.71 



6.04 

 2.85 

 0.52 

 1.75 

 3.94 

 0.70 

 3.74 



8.48 

 0.00 



2.42 



1.83 

 0.68 

 0.32 

 0.62 

 0.50 

 0.08 

 0.53t 



81.97 

 100.00 



81.90 



74.11 



78.30 

 58.43 



70.85 



87.17 



88.61 



lOO.OOt 



18 03 



ALO, 



00 



re.,Oo 





FeO 



18.10 



CaO 



MgO 



MnO 



25.89 

 21.70 

 41.57 



K2O 



29.15 



Na,0 



12.83 



P„0, 



11.39 



Ign 



0.00 









100.00 



100.00 



14.93% 





From these figures it appears that there has been a loss of some 14.93 

 per cent of all constituents. The increase in water, as indicated by the 

 ignition, is a natural consequence of hydration and the presence of a 



* Since tlie process is in part physical, the term decomposition is hardly applicable here, A 

 comprehensive term, noncommittal as to which force is operative, is needed. Rather than coin a 

 new word, and as preferable to " breaking down," I have used the term degeneration. 



tGain. 



X The calculation gives 119.49 per cent, showing a gain in volatile matter, as is to be expected. 



