Rcvieiv of Recent Geological Literature. 391 
great mining industry. The chapter upon ore deposits occupies 240 
pages and, indeed, might have been named "The principles of ore de- 
position." From the author'-s point of view, the majority of ore de- 
posits are produced by metamorphic processes. Having worked out the 
general principles of metamorphism with reference to rocks, the author 
found that the application of these principles to ore deposition explained 
the majority of ore deposits. From his point of view the proper theory 
of ore deposition consists mainly in bringing the particular phenomena 
exhibited by ore deposits under the general principles of metamorphism. 
The chapter contains a new classification of ore deposits, the funda- 
mental divisions of which are the same as those of rocks. Thus ore 
deposits are divided into three classes, those of sedimentary origin, those 
of igneous origin, and those of metamorphic origm. Strictly the treatise 
on metamorphism should, perhaps, have considered only the third class. 
However, the first and second classes are sufficiently discussed so that 
the relations of these ores to those produced by metamorphic processes 
may be appreciated. The discussion upon ore deposits is too elaborate 
to be summarized in this general statement. But it may be remarked 
that for the metamorphic ores an attempt is made to trace out the solu- 
tion, transportation, and precipitation of each of the chief economic 
mietals. Also the alterations and further segregation of metals are fully 
considered. The conclusion is reached that in many cases an ore deposit 
does not represent a single siegregation. but is the result of repeated 
segregations by the same general processes which result in the depletion 
in certain elements of the various rock formations and their segregation 
elsewhere. In other words the principles of the development of ore 
deposits are the principles of the segregation of those elements which 
are of importance to man, but which, for the most part, are so rare 
that they are not included in the discussion in the chapter upon the re- 
distribution of chemical elements. 
It is not possible in a. summary to give anv adequate idea of the 
scope of this treatise on metamorphism. A very broad range of facts, 
extending far beyond what might at first be regarded as a part of a 
treati.se on metamorphism, is considered from the energy point of view. 
It is believed that the volume marks a. great stride in the reduction of 
the entire subject of physical geology to order under the principles of 
physics and chemistry, and points out the way for a treatment of the 
entire subject from this point of view. • h. c. r. 
Volcanoes and Seismic Centers of the Philippine Archipelago. By Re*.'. 
M". S.\derr.\ M.Jiso. Assistant Director of the Philippine Weather 
Bureau. Bulletin 3, Census of the Philippine Islands. Pages 80: 
with maps, outlines, and views from photographs. Washii'.gton. 
D. C. 1Q04. 
This report, written for the Philippine Census by Father Masn, 
who, during the past fifteen years has been connected with the fully 
equipped seismic observatory in Manila, presents descriptions. and \\i%-^ 
tory of the volcanoes and tracts of origin of earthquakes in this great 
