I04 REVIEWS 



The sequence of crystallization was uniform for all systems, and was 

 independent of the mineral proportions, and eutectics. Eutectic texture 

 was absent. The following was the observed order for all proportions in 

 the respective systems: 



I. Diopside, anorthite, diopside. 

 II. Diopside, olivine. 



III. Diopside, nepheline. 



IV. Magnetite, diopside, augite, and anorthite. 

 V. Magnetite, olivine, and augite. 



VI. Olivine, diopside, anorthite, and diopside. 

 VII. Olivine, diopside, and nepheline. 

 VIII. Olivine, diopside, and orthoclase. 



Freis believes that the crystallization sequence followed Rosenbusch's 

 law of increasing acidity of the magma, influenced by undercooling, the 

 force of crystallization, and the solubility law of Nernst. 



Differentiation phenomena consisting of local, ill-defined crystal aggre- 

 gations or schlieren; sharply defined segregations of certain mineral aggre- 

 gates; local variations in grain; and segregation in the inverse order of 

 specific gravity were observed. Magnetite seemed to be segregated near the 

 top of the melt. Forsterite or iron-free olivine, formed at the bottom, 

 while iron-bearing diopside occupied an intermediate zone. 



The order of crystallization and the differentiation phenomena observed 

 by Freis therefore differ in many ways from certain generally accepted theo- 

 retical views on magmas. 



E. S. 



