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this line of investigation, and it is from this standpoint in particular that 
the Handbuch will be considered the authoritative work of reference. 
Consequently it is not merely a treatise on mineral chemistry. It 
cannot fail to deal as well with the most fundamental problems of 
petrogenesis. 
Some difficulty has been experienced in arriving at an entirely satis- 
factory arrangement of the material. The older classification of Groth, 
in which the elements that occur as minerals are first disposed of, has 
been discarded, and an arrangement has been adopted which is based on, 
but does not follow in complete detail, the periodic classification of the 
elements. Thus in the volume now before us carbon and its compounds 
are first dealt with, and the treatment of silicon and of some of the general 
aspects of the silicates then follows. Out of some 150 articles it is 
perhaps invidious to single out any particular cases, as the selection 
inevitably depends materially on the subjects in which the reviewer is 
specially interested. Two of the features of the first volume to which the 
writer has given more careful attention are the articles on the carbonates 
by Leitmann, and Doelter’s paper on silicate melts. Leitmann in a long 
series of articles has dealt with the naturally occurring anhydrous car- 
bonates, and has handled a literature of enormous proportions with 
marked judgment and reserve. Particularly valuable are the discussions 
on synthesis and processes of formation in nature, and the physico- 
chemical treatment of the solubilities. It is part of the plan of the 
Handbuch to introduce a broad division of the minerals by an article 
dealing with the whole or part of the field from the comparative stand- 
point: and Linck’s suggestive article on the carbonates of lime, iron, and 
magnesia summarizes the work of the Jena school on the stability 
conditions of these compounds as they occur in nature. 
Doelter’s contributions to this volume deal with the formation of 
graphite, the carbonates, phosgenite, silicon, the synthesis of the silicates, 
and silicate fusions. The last is an article of almost 200 pages, which 
reviews the whole field and emphasizes the lines of investigation at present 
being pursued. On some points in this paper there will be a decided 
difference of opinion. While it cannot be doubted that Doelter’s 
insistence on the registration of two temperatures on the fusion curve 
gives a much-needed emphasis to the fact that silicates react with 
remarkable slowness, the methods on which he has chiefly relied can. 
hardly be considered to have been so fruitful in the interpretation of two- 
component systems as the methods of thermal analysis applied by 
Tammann and his school to the alloys and later to the silicates, or as used: 
