190 The American Geologist. March, 1891 
erature. The only text-books available until recently have been mere 
primers, containing the barest outline of description and some tables 
of statistics. 
The book before us is intended to supply this deficiency and to fur- 
nish also an accurate account of our mines and valuable rocks and 
minerals, and their importance as compared with other countries. Be- 
ginning with a clear and readable presentation of the geological truths 
necessary for an understanding of the various deposits described 
later, the first 70 pages are devoted to a discussion of common minerals 
and rocks and the influence of physical geography and topography on 
the distribution and extent of ore deposits. The origin of ore deposits, 
and the methods of mining are treated in the next 40 pages of Part i. 
Part ii discusses the metalliferous deposits in the order of their im- 
portance to man, beginning with iron. This occupies nearly 200 pages; 
while 150 pages are devoted in Part in to the non -metallic mineral 
products. 
There is an appendix consisting of a list of treatises on economic geol- 
ogy and ore deposits in general or upon particular subjects. This is 
very poor, and will be of almost no value to a reader unfamiliar with 
the subject. He would not know where to procure many of the works 
listed nor what their size, or value. Such a list should contain com- 
plete data as to the name of the author, date and place of publication, 
together with the names of the publishers and size and cost of the 
volume. There is a good index which adds to the usefulness of the 
work. The illustrations are well-drawn and clearly printed. 
A treatise of this sort might be written from many points of view, 
geological, chemical, mining, statistical or metallurgical. This is evi- 
dently from the standpoint of a geologist, and it is not strange there- 
fore that it is strongest and most explicit in its statement of geological 
facts, although the statistical side is also very well cared for, and there 
is a fund of varied information on all branches of the subject treated. 
The style of the work is easy and entertaining, but the statements 
are not always made with perfect accuracy. At the risk of appearing 
hypercritical regarding a work which contains so much that is com- 
mendable, we shall mention a few points where there is a chance for 
improvement, or, at least, for difference of opinion. On page 2, for ex- 
ample, we find that "upon the surface (of the earth) nearly all of the 
elements are in chemical combinations of greater or less definiteness, 
and these are called minerals." The definition is loose. The majority 
of combinations of elements on the surface of the earth are not miner- 
als. Again, on page 80, ore deposits are divided into three main classes: 
1. Eruptive; 2. Mechanical; and 3. Chemical. But since all the opera- 
tions of nature are primarily chemical or the result of chemical action, 
the classification evidently refers to the kind of action which has had 
for its direct and immediate result the production of the ore in the 
place where we find it. If this view be taken, it seems that the division 
"eruptive" is not coordinate with "mechanical' 1 and "chemical,"' but 
ehould rather be a division under "mechanical." of equal rank with 
