Reviews. 



A Treatise on Metamorphism. By Charles Richard Van Hise. 

 (Monograph XL VII, U. S. Geological Survey.) Washington, 

 D. C. Pp. 1,286; 13 plates. $1.50. 



This treatise is an attempt to reduce the phenomena of metamorphism 

 to order under the principles of physics and chemistry, or, more simply, 

 under the laws of energy. Metamorphism is broadly defined to include all 

 alterations of all rocks by all processes. The metamorphism of the sedi- 

 mentary rocks was the first subject studied by the author, and metamor- 

 phism has been a chief line of investigation with him for more than twenty 

 years. Finding that the alteration of rocks was nowhere systematically 

 treated, he took up the task of preparing such a work. It was supposed 

 that this work would occupy two or three years, but, as a matter of fact, it 

 required seven years, and an eighth year has been needed to put the volume 

 through the press. 



The book consists of twelve chapters. Chapter i discusses the geologi- 

 cal principles upon which a classification of metamorphism may be based. 

 From this discussion it is concluded that the only practicable classification 

 of metamorphism is geological. It is found that the alterations of the outer 

 zone of the earth are radically different from those of the deep-seated zone. 

 Moreover, it is shown that the alterations in the upper zone result in the 

 production of simpler compounds from more complex ones, while those in 

 the deep-seated zone result in the production of complex compounds from 

 more simple ones. The upper zone is called that of katamorphism, and the 

 lower zone that of anamorphism. 



Chap. 2, upon the forces of metamorphism, discusses chemical energy, 

 gravity, heat, and light. The manner in which each of the classes of 

 energy produces various mechanical and chemical effects upon rocks is set 

 forth. 



Chap. 3 treats of the agents of metamorphism. The agents of meta- 

 morphism are gaseous solutions, aqueous solutions, and organisms. Under 

 aqueous solutions the chemical and physical principles controlling the action 

 of ground water and the circulation of ground water are fully discussed. 

 This involves a full resume of the science of physical chemistry, so far as 

 applicable to the alterations of rocks. This resume is not simply a summary 



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