256 



SCIENCE PROGRESS 



great proportions as the lime. The alumina proportion culminates 

 in the syenites. 



CaO -256 



MgO -142 

 A1 2 3 -13 



«2 0+Na 2 -096 



Ka,0 -06 

 KjO -056 



FeO -OS 7 



Fig. 4. — Diagram of the Molecular Proportions of the Potash Series. 



The Soda Division of the Alkali Series 

 Table of Analyses of Rock- types 



ioo"66 



101-37 



100-76 



99-92 



I. Soda-granite (" Natron-granit " of Brogger), Hougnatten, Lougenthal 

 Norway. L. Schmelck. Quoted in Washington's Chemical Analyses, 

 p. 155. 



