28 
NADORE 
[May 11, 1899 
canoes,” contains succinct descriptions of a number of 
celebrated volcanic outbursts, including that of Vesuvius 
in A.D. 79, and later eruptions, of Monte Nuovo in 1538, 
of Stromboli, Bandai-san in Japan, Galoongoon in Java, 
Krakatoa, Kilauea'in the Sandwich Islands, Skaptar J6kull 
in Iceland, Cotopaxi, Graham Island, and Bogosloff in 
Behring’s Sea ; lastly, of the mud volcanoes of Baku, and 
of Krabla in Iceland, and the geysers of the Yellowstone 
Park. These examples are admirably chosen to illustrate 
the varied manifestations, andsuccessive phases of volcanic 
activity, and serve at the outset to give the student a clear 
idea of the nature and sequence of the phenomena, which 
it is the object of the work to explain. 
The second chapter deals with “The products of 
volcanoes,” and init the author has evidently experienced 
some difficulty in maintaining the popular character of 
the work, while at the same time supplying accurate 
petrographical information. The explanation of mineral 
and rock names being relegated to a glossary, a fairly 
complete sketch is given of the classification and nomen- 
clature of the igneous rocks. The admirable photo- 
graphs of rock-sections in this part of the work serve to 
make the descriptions more intelligible. 
In the third chapter, on ‘‘ The dissection of volcanoes,” 
an account is given of the results obtained from the study 
of volcanic piles in various stages of degradation under the 
agencies of denudation. Commencing with the “puys ” 
of Auvergne, which Prof. Bonney describes from per- 
sonal observation, and going on to the Eifel with its 
crater lakes, the great lakes of Central Italy and 
Oregon are alluded to, and then the more or less ruined 
volcanic cones, and crater rings of Santorin, Etna, and 
other districts are referred to, to illustrate the salient 
features of volcanic structures ; and in the end illustra- 
tions are taken from the still more ruined volcanoes of 
central Scotland and Hungary, and from the structures 
which have received the name of laccolites im the 
western territories of the United States, and the midland 
district of England. 
The next chapter is on ‘The geological history of 
British volcanoes,” and attempts a chronological sketch 
of volcanic activity in the British Islands. Prof. Bonney 
in the main adopts the results arrived at on this subject 
by the officers of the Geological Survey, though he points 
out that many of their conclusions are not free from 
doubt. The sixth chapter, which gives a sketch of “ The 
distribution of volcanoes,” brings the descriptive portion 
of the book toa close. In this part of the work, much 
information has been incorporated which has _ been 
obtained by travellers and others during the last twenty 
years, and since the time at which most of the earlier 
English treatises on vulcanology have appeared. The 
general account of volcanoes all over the globe, with the 
discussion of the main features of their geographical dis- 
tribution, is as complete and full as could be expected in 
some eighty pages, and enables the author to marshal a 
number of facts which are of the greatest service in lead- 
ing up tothe theoretical speculations to which the seventh 
and last chapter are devoted. 
In referring to Prof. Bonney’s remarks upon volcanic 
theories, it is only fairto point out that he himself admits 
that he is unable to supply “any complete theory of 
vulcanicity,” and that he thinks we must wait for some 
NO. 1541, VOL. 60] 
time before any such theory, which will satisfy all the 
conditions of the problem, will be found. To use his 
own words :— 
“We are, I think, in this position: We have ascer- 
tained a number of important facts; many of these 
suggest conclusions, but some of the latter seem at pre- 
sent difficult to reconcile and harmonise. Indeed it is 
my opinion that either some link in the chain of evidence 
still remains to be discovered, or the relation of those 
which we know is not yet fully understood. In other 
words, we do not seem to be in a position to put forward 
a complete explanation of vulcanicity. Nevertheless, I 
am sanguine that, to borrow an appropriate phrase from 
a child’s game, ‘ we are getting warm,’ and that our suc- 
cessors, by the end of the first quarter of the coming 
century, will have got much nearer to the solution of 
the problem.” 
In spite of this disclaimer on the author’s part of any 
ability to propound a complete theory of vulcanicity, the 
concluding chapter of the work may be scanned alike by 
the general reader and the student of science with much 
profit. An account is given of numerous speculations 
upon the various portions of the question of vulcanicity, 
which have of late years attracted considerable attention, 
and the author’s criticisms and suggestions are well 
worthy of perusal and consideration. 
The volume, which is one of the handsome “ Pro- 
gressive Science Series,” is admirably printed and fully 
illustrated ; it constitutes a valuable addition to the 
popular books of science of the day. eee 
OUR BOOK SHELF. 
Recueil de données numeriques publié par la Société 
Jrancaise de Physique, Optigue. Par H. Dufét. 
Deuxiéme Fascicule. Propriétés optiques des Solides. 
Pp. vi + 367. (Paris: Gauthier-Villars, 1899.) 
THE data collected in this volume should prove of value 
in physical and chemical laboratories. The first section 
contains the indices of refraction, and their variation with 
temperature, of calcite, quartz, fluorine, rock-salt, sylvine 
(potassium chloride), and common alum. The second 
collection of tables comprises determinations of the re- 
fractive indices, at ordinary temperatures and for various 
wave-lengths, of glasses of known chemical composition. 
The optical properties of solid inorganic substances are 
tabulated in the third section, and of organic bodies in 
the fourth. These two sections occupy the greater part of 
the volume, and they should be of particular service to 
mineralogists and chemical crystallographers. Tables 
on the influence of temperature on the optical properties 
of solids, and on the indices of some metals and metallic 
compounds conclude the work. 
The Natural Mineral Waters of Harrogate. By F. W. 
Smith, M.D. Pp. ror. (London: Dawbarn and 
Ward, 1899.) 
Dr. SMITH considers the natural waters of Harrogate 
chemically, therapeutically, and clinically, with reference 
to their suitability for drinking and bathing purposes. He 
maintains that the springs of Harrogate compare very 
favourably with those of Baden-Baden, Homburg and 
Kissingen, and that there is no need for invalids to run 
the risk of a journey to the Continent. Full analyses, by 
trustworthy chemists, are given of all the varieties of 
mineral waters with which this Yorkshire spa is endowed, 
and much valuable information concerning the local rain- 
fall, temperature and mortality should cause this well- 
illustrated volume to take its place as a handy guide for 
“the doctors of this country,’ to whom Dr. Smith 
dedicates his work. 
