REVIEWS 307 



of the essential minerals of granite — quartz, mica and acid feldspar. 

 The influence of the tungstic acid the author believes to be as follows : 

 after the temperature in the first melting has passed 1000 , neither 

 tridymite nor quartz can form, because at these high temperatures the 

 silica unites with alkalies to form a silicate, in which the tungstic acid 

 is absorbed; it is believed that on lowering the temperature (the posi- 

 tion of crucible which ultimately produced crystallization) the absorbed 

 tungstic acid has the effect of decomposing these alkaline silicates 

 and liberating the silica to form qaartz. It is not known what com- 

 pounds the tungstic acid finally forms. Dr. Morozewicz objects 

 strongly to the use of the term "mineralizer," and considers that 

 much harm has been done to the progress of synthetic mineralogy by 

 attributing all obscure reactions to the " mystical action of a mineral- 

 izer." He insists that "agent mineralisateur " has no scientific mean- 

 ing and should be banished from the vocabulary of the mineralogist. 

 This would seem a little unreasonable, in view of the fact that he him- 

 self acknowledges that his only success in obtaining crystallization of 

 the granitic minerals was due to the action of a small amount of 

 tungstic acid, which he explains by what at best is only an incomplete 

 hypothesis. Modern petrographers have not ascribed any "mystical" 

 power to the compounds of tungsten, zirconium, boron, fluorine, etc., 

 but have observed that these elements are minor but invariable accom- 

 paniments of the crystallization of coarse acid pegmatites. Moroze- 

 wicz has only added confirmatory evidence from synthesis of the actual 

 importance of these agents to promote crystallization in an acid magma, 

 and whatever they be called, their influence, whether chemical or physi- 

 cal, cannot be denied. Possibly the word " crystallizer " would be 

 more exact than "mineralizer." It is certainly true, on the other 

 hand, as Morozewicz points out, that this latter word has been much 

 abused, and simple reactions have been allowed to pass unexplained as 

 due to the action of a mineralizer, because a fluoride or a borate 

 chanced to be in the equation. 



The accompanying plates are reproduced to show the coarseness of 

 crystallization obtained with basic magmas. The basic magmas are 

 those still capable of dissolving free alumina, or, in other words, unsat- 

 urated. An enstatite basalt was produced from a mixture of three parts 

 olivine, three parts labradorite, and one part augite. A large mass of 

 this material was fused, a smaller quantity being separated for fusion 

 with iron oxide (hematite) alone, the principal mass having a little 



