NATURE 
337 

THURSDAY, MAY 27, 10915. 
THE SCIENCE OF VULCANOLOGY. 
The Problem of Volcanism. By Dr. J. P. Iddings. 
Pp. xvi+273. (New Haven: Yale University 
Press; London: Oxford University Press, 
1914.) Price 21s. net. 
HIS work is the latest published of a series 
issued by the Yale University, acting as 
trustees for the Silliman Memorial Fund; the fund 
consists of the sum of 85,000 dollars left to pro- 
vide for the delivery and publication of annual 
courses of lectures ‘to illustrate the presence and 
providence, the wisdom and goodness of God, as 
illustrated in the natural and moral world.” A\I- 
though the terms of the bequest strikingly recall 
those of the once-celebrated “Bridgewater Trea- 
tises,” yet the testators of the Silliman Fund 
qualify the statement of terms by a declaration 
of a belief that “any orderly presentation of the 
facts of nature or history contributed to the ends 
of this foundation more effectively than any 
attempt to emphasise elements of doctrine or of 
creed.” In the end they conclude that dogmatic 
and polemical theology should be excluded, and 
that “the subjects should be selected from the 
domains of natural science and history, giving 
special prominence to astronomy, chemistry, geo- 
logy, and anatomy.’’ A comparison of the terms 
. of the Bridgewater and Silliman foundations give 
a by no means unsatisfactory impression of the 
improved relations between the representatives of 
natural science and’ theology which have arisen in 
the course of the last century. 
With characteristic impartiality the authorities 
of Yale University have invited representatives of 
various branches of science to give clear and up- 
to-date presentments of the condition of our 
knowledge on the subjects selected by them. The 
successive courses of lectures have been given by 
Profs. J. J. Thomson, Sherrington, Rutherford, 
Bateson, and Sir W. Osler from this country; 
by Profs. Nernst and Max Verworn from Ger- 
many; and by Arrhenius from Sweden; only three 
of the published courses, indeed, are by American 
men of science. 
For the science of vulcanology no better repre- 
sentative could possibly have been found than Dr. 
Iddings, and no more striking illustration of the 
progress of investigation and theory could be 
given than his discussion of the problem. Fifty 
years ago the question was thought to be virtually 
settled by the assumption of a molten central mass 
constituting the earth’s interior, or at least of 
pockets of such heated material at moderate 
depths; granted this, it was believed that all the 
NO. 2378, VOL. 95| 



explosive and eruptive actions of volcanoes cou!d 
be accounted for by the access of sea-water to 
these incandescent materials through fissures in 
the earth’s solid “‘crust.’”’ Now, after a full dis- 
cussion of the astronomical, physical, chemical, 
and geological evidence involved, the author shows 
that there are no valid grounds against the conclu- 
sion that the earth’s interior is solid and cold, and 
that all thermal action may be attributed to radio- 
activity, whilst many problems of far greater com- 
plexity than were ever thought of in the past 
await solution. 
Although every outstanding branch of the in- 
quiry meets with full and sympathetic treatment 
at the hands of the author, yet it is on the char- 
acteristics and relations of voleanic rocks that he 
writes with special authority, and more particu- 
larly on the light which has been thrown on 
petrology by microscopic research, the branch of 
study with which Dr. Iddings has been so long 
identified. But whether dealing with such 
problems as those belonging to his own studies 
or such varied questions as are suggested by the 
characters of nebula, Dr. Iddings is equally at 
home; and nowhere, to our knowledge, can there 
be found an account, so complete and illuminat- 
ing, of all the varied lines of research bearing on 
the subject under discussion. A word of praise 
must be added for the numerous and_ beautiful 
illustrations, while the printing of the work 
exhibits all those excellences which we are accus- 
tomed to find issued in the 
United States. Ne No ile 
in scientific works 
LIQUIDS UNMATHEMATICALLY TREATED. 
(1) The Dynamics of Surfaces: an Introduction to 
the Study of Biological Surface Phenomena. 
By Prof. L. Michaelis; translated by W. H. 
Perkin: Pp. viii; 118. (London: E. and F. N. 
Spon, Ltd., 1914.) Price 4s. net. 
(2) Motion of Liquids. By Lieut.-Col. R. De 
Villamil. Pp. xiv+210. (London: E. and 
F. N. Spon, Ltd., 1914.) Price 7s. 6d. net. 
(3) Liquid Drops and Globules: Their Formation 
and Movements. By C. R. Darling. Pp. x+ 
83. (London: E. and F. N. Spon, Ltd., 1914.) 
Price 2s. 6d. net. 
(1) HE first part of the title of Dr. Michaelis’s 
elk book is erroneous and misleading, for 
a mathematical physicist will fail to find anything 
whatever in these pages dealing with the dynamics 
of surfaces. It treats entirely of certain physico- 
chemical and electrical phenomena connected 
mainly with surfaces of separation of different 
media, and it makes no attempt at a rigorous 
theoretical investigation of these. As an illustra- 
O 

