May 25, 1899] 
NATURE 77 
Further evidence of this appears in the tables of separ- 
ations, which are printed on parchmentised paper, and 
open out on each side of the stitching, 
“so that if anything is spilled on to the book as it lies 
open at any of the tables, the result will not be so 
disastrous as it otherwise might be,” 
and the underlying pages will be protected. This cer- 
tainly suggests scale practising. Taking the author’s 
purpose as he states it, we have carefully read the book 
and examined the methods prescribed. We believe cer- 
tainly that the analytical methods are sound ; but we 
should hesitate to say that, in this respect, this book is 
superior to a dozen others that could be named. It is 
written undoubtedly by one who has a mature knowledge 
of his subject, and the processes described satisfy all 
reasonable requirements in point of accuracy ; but we 
find hardly anything noteworthy in the mode of pre- 
senting the subject or in the details—nothing certainly 
that will warrant us in saying that this is conspicuously 
the book for a sound method. In other respects, it 
makes no special claim. The sections of “‘ Comparative 
Remarks” on the elements or radicals of a group are 
likely to be useful, but as an exposition of the theory of 
analysis as well as the practice the book leaves much to 
be desired. 
Mr. Chapman Jones’ second book is written to suit 
the syllabus of the Science and Art Department for 
practical inorganic chemistry in the advanced stage. 
The analytical part of it is adapted from the work just 
noticed. The rest includes the preparation of gases and 
some volumetric analysis. As all the topics of the 
syllabus are dealt with, the book will no doubt suit its 
immediate purpose. The mode of treatment calls for 
remark in one particular only. The preparations are 
grouped as follows :—Preparation of gases by the use 
of cold liquids, ditto by the use of hot liquids, ditto by 
the heating of dry substances, preparations involving 
distillation, preparations made in solutions. A protest 
must be entered against a mode of classification so 
entirely divorced from educational purpose. Even if 
there were practical convenience in it, which we do not 
admit, that would by no means justify a sequence of ex- 
periments dictated by considerations of merely having 
this or that piece of apparatus handy for use. 
A book entitled “ Advanced Inorganic Chemistry,” 
written for “The Organised Science Series,” and con- 
taining in the preface a statement that a certain liberality 
of treatment (of chemical physics) is justified by the im- 
portance attached in the syllabus to the subject, is 
calculated to raise prejudice in the mind of a reader. 
We make haste to say, therefore, that Dr. Bailey’s book 
contains very little evidence, if any, of having been 
written to conform toa syllabus, or to provide, information 
in that highly compressed and uninspiring form, which 
until recent times has seemed to prove most suitable for 
meeting the requirement of the Science and Art Depart- 
ment. The book begins with a short account of the 
properties of gases,including a good account of Avogadro’s 
hypothesis, of dissociation, and of the methods of de- 
termining the composition of gases. In stating that equal 
volumes of a/Z gases . . . contain the same number of 
molecules, the author, we think, underlines the wrong 
NO. 1543, VOL. 60] 
word. The whole advance made by Avogadro is surely 
embodied in the word molecudes: it was not the intro- 
duction of the idea of equal numbers (as beginners are so 
often taught), nor the mere extension of an existing 
generalisation. The chapter on the atomic weights of the 
elements is excellent in most respects, but we regret to see 
the statement that a measure of the chemical attraction 
or affinity exerted between two elements is afforded by 
the heat developed by their union. An unqualified state- 
ment of this kind is calculated to instil a fundamentally 
wrong idea of the relationship between heat and chemical 
affinity. In the main part of the book dealing with the 
elements and their compounds, the mode of treatment 
is broad and luminous, and the information is well 
selected. Some few deficiencies in detail are to be 
found ; but, on the other hand, there are many little 
features in which the book is an improvement on 
others of like scope. The following points are, perhaps, 
worth noting. Cryohydrates are mostly mixtures of ice 
and salt, and not definite compounds, as implied on pp. 
60 and 67. On p. 103, the production of iodine by the 
action of sulphuric acid on potassium iodide may be 
better explained by the reducing action of hydriodic acid 
on sulphuric acid than by the mere decomposition of the 
hydriodic acid fer se. The preparation of silicon from 
silicon dioxide and of boron from boron trioxide by means 
of magnesium, and also the preparation of silicon hydride, 
easily demonstrated in test-tubes, are not mentioned, nor 
is justice done to the energetic properties of boron. The 
preparation of potassium chlorate by electrolysis of 
potassium chloride is not mentioned ; and though the 
electrolytic preparation of sodium is described, the figure 
which illustrates the process is hardly comprehensible. 
Three useful appendixes on crystallography, spectrum 
analysis, and chemical calculations, and a series of 
chemical problems, conclude the book. Owing to some 
printing accident, the appendix on spectrum analysis ends 
prematurely in the middle of a sentence. IN) 1S} 
THE MODERN BICYCLE. 
La Bicyclette: sa Construction et sa Forme. Par Dr. 
C. Bourlet. Pp. 228. (Paris : Le Génie Civil ; Gauthier- 
Villars, 1899.) 
epee is a reproduction of a series of articles which 
appeared in vol. xxxiii. of Le Génie Civil, and forms, 
in some measure, a supplement to the author’s “ Nouveau 
Traité des Bicycles et Bicyclettes.” With the exception 
of an appendix on the theory of ball-bearings, the 
present work is non-mathematical in character, and is 
addressed to all cyclists who take an intelligent interest 
in their machines. The first chapter is devoted to an 
historical summary, then follow chapters on the frame, 
steering, bearings, gearing, change-speed gears, wheels 
and tyres, tricycles, accessories, and hygiene of touring. 
The work is to be warmly welcomed, as adding to the 
far too scanty independent literature on the construction 
of the bicycle. We feel somewhat at a loss, however, as 
to the standpoint to be taken in reviewing the book. In 
the historical portion many events which, on this side of 
the Channel at least, are regarded as of primary im- 
portance are not even referred to—e.g. Kirkpatrick 
