496 
and the climates of the earth’s surface; V., 
the difficulties in the way of navigation due to 
storms, head winds, calms and fog; VI., the 
movements of the ocean, viz., waves and tides. 
Of these chapters the fifth seems to us perhaps 
the most generally useful inthe book. It deals 
with the nature, seasons, tracks and character- 
istics of cyclones in the different oceans, and 
the rules for navigating when in the vicinity of 
a cyclone. The relation of the prevailing winds 
and calm belts to various sailing routes are 
clearly presented, and the prevalence of fog in 
different regions is briefly discussed. 
In connection with the sailing directions, 
Koppen makes use of an ingenious device, 
modelled after Piddington’s famous transparent 
storm cards in his classic ‘ Sailors’ Horn Book 
for the Law of Storms.’ K6ppen’s storm card 
consists of a transparent sheet of paper, on 
which are three figures. The first shows the 
winds around a cyclone in the Northern Hemis- 
phere; the second shows the winds around an 
anticyclone in the Northern Hemisphere ; and 
the third shows the characteristic isobaric 
types and accompanying wind changes during 
the easterly movement of ordinary weather con- 
ditions. By turning the transparent paper 
over, the same diagrams serve for the Southern 
Hemisphere. 
Such a book as Koéppen’s Grundlinien der 
Maritimen Meteorologie should be translated into 
English, and it is to be hoped that the author 
will arrange to have an English edition pub- 
lished shortly. R. DEC. WARD. 
Descriptive General Chemistry. By 8S. BE. TILu- 
MAN, Professor in the U. 8. Military Acad- 
emy. New York, John Wiley & Sons. 1899. 
2d Ed., p. 429. 
This new aspirant for chemical honors has 
been written mainly for the use of the cadets of 
the U. 8. Military Academy. In the language 
of the author ‘‘it has generally been the con- 
clusion of those charged with this instruction 
at the Academy in the past that the laboratory 
method alone, or mainly, in so short a course, 
could not be made of as much value to the pu- 
pils as the method of making the acquisition of 
knowledge the essential feature, and that the 
best results could be reached through careful 
SCIENCE. 
[N. S. Vou. X. No. 249. 
study of the proper text, well-conducted reci- 
tations, accompanied by experimental and 
explanatory Jectures.’? Accordingly ‘‘ this 
book has been prepared to embody the sub- 
stance and arrangement of a short chemical 
course for the general student. It aims to give 
a concise statement of the more fundamental 
principles of chemistry, together with that class 
of chemical information most essential to cul- 
tured men, and which will enable them to 
comprehend many ordinary natural phenomena, 
as well as to understand the more important 
applications of the science which are now so 
frequently met with. The book is not fitted 
nor intended for laboratory guidance.’’ 
It is an interesting production and merits 
high praise and a cordial reception from all 
interested in the promulgation of chemical 
science. EpGAr F, SMITH. 
Elementary Studies in Chemistry. By JOSEPH 
Torrey, Jr., Harvard University. New 
York, Henry Holt & Co. 1899. Pp. 487. 
Nearly every teacher of chemistry in time 
feels that even the best text-books which have 
been prepared are not just exactly what he de- 
sires. He is imbued with the idea that what he 
wishes the student to derive from a course of 
chemical instruction can be better obtained by 
some other method or plan than any previously 
proposed. In other words, he wishes to reach 
the goal in his own peculiar way. He knows 
what that goal represents, how he reached it, 
and is firmly convinced that by his method 
those placed in his charge can also gain it. 
The usual result of this reasoning is eventually 
anew book on chemistry. The author of the 
present volume, ‘dedicated to my students, 
past and present,’ has doubtless had his own 
experience in getting young men to profit by 
careful drill in chemical experimentation, etc., 
and in this new contribution outlines his method 
of instruction. 
The reviewer has had great pleasure in fol- 
lowing the different steps of the development, 
and is happy to add that in his humble judg- 
ment, Mr. Torrey has prepared a most valuable 
student guide, and deserves the congratulations 
of both students and teachers of the science. 
EpGar F, SMITH. 
