APRIL 21, 1904] 
INA T ORE: 
579 
logical conditions is duly considered, and Mr. Havelock 
Ellis summarises his conclusions as follows :— 
““We cannot, therefore, regard genius either as a 
purely healthy variation occurring within normal 
limits, nor yet as a radically pathological condition, not 
even as an alternation—a sort of allotropic form—of 
insanity. We may rather regard it as a highly sensi- 
tive and complexly developed adjustment of the nervous 
system along special lines, with concomitant tendency 
to defect along other lines. Its elaborate organisation 
along special lines.is often built up on a basis even less 
highly organised than that of the average man. It is 
no paradox to say that the real affinity of genius is 
with congenital imbecility rather than with insanity.” 
The criticism will doubtless be made that in many 
cases the individuals dealt with by Mr. Ellis are too 
few in number to give trustworthy results; but this 
is a matter that was beyond his control, and no one 
can say that he has not made the most of available 
material. 
LEXT-BOOKS OF. PHYSICAL CHEMISTRY. 
Introduction to the Study of Physical Chemistry. By 
Sir William Ramsay, K.C.B., F.R.S. Pp. 48. 
(London: Longmans, Green and Co., 1904.) Price 
Is. net. 
The Phase Rule and its Applications. By Alex. 
Bindlay, a VicAC bh Di DsSe.) Pp: Ixivi 313. 
(London: Longmans, Green and Co., 1904.) Price 
5S. 
T will be readily admitted that there is on the part 
especially of our younger chemists, a growing 
appreciation of the methods and results of physico- 
chemical investigation, and the issue of a series of 
text-books of physical chemistry under the able super- 
vision of Sir William Ramsay will be a welcome 
stimulus to the prosecution of study and research on 
these lines. Dr. Findlay’s book on the phase rule is 
the first of the series, and other volumes are promised, 
dealing respectively with stoichiometry, relation 
between chemical constitution and physical properties, 
electrochemistry, spectroscopy, thermodynamics, 
chemical dynamics and reactions. The advance being 
made in some of these departments is much more 
rapid than in others, and the plan of having a volume 
for each branch of the subject will make frequent re- 
vision possible where there is a call for it. 
Taken altogether, these volumes will be an accept- 
able addition to our chemical literature, for up to now 
the English student. of physical chemistry has been 
dependent chiefly on translated text-books for detailed 
treatment of certain advanced portions of the subject. 
One or two of the promised volumes, it is true, will 
cover well trodden ground, but they are requisite in the 
interests of the treatise as a whole, and the editor will 
doubtless see that harmony and uniformity are pre- 
served in the several parts. He has written a general 
introduction to the series, giving a rapid survey of the 
main lines along which the development of physical 
chemistry has proceeded, and indicating the scope of 
the subjects to be dealt with in the special volumes. 
The mere mention of the phase rule usually strikes 
dismay in the heart of the non-mathematical chemist, 
NO. 1799, VOL. 69] 
but it may be said at once that Dr. Findlay’s treat- 
ment of the subject is almost entirely descriptive. The 
phase rule can be formulated in a simple enough 
manner, and its application can be appreciated even by 
those who may not feel at home with Willard Gibbs. 
Its merit is that it has rendered possible the classifi- 
cation of the various kinds of equilibria on a rational 
and scientific basis. The parallelism between many 
cases of physical and chemical equilibrium becomes 
intelligible; the phenomena of polymorphism, as ex- 
hibited, for example, by sulphur, tin, and benzo- 
phenone, can be treated systematically, and the con- 
ditions of stability of various polymorphic forms can 
be definitely formulated; the equilibrium between solid 
and liquid in binary systems can be fully interpreted, 
even when the two components form mixed crystals. 
In the exposition of these and many other points Dr. 
Findlay has done excellent work, and he has succeeded 
in producing an interesting and comprehensive esti- 
mate of the value of the phase rule in the classification. 
and interpretation of equilibrium phenomena. ~ 
It is a very gratifying feature of the book that it 
contains full and up to date references to original. 
work, and it is to be hoped that this feature will be 
prominent also in the subsequent volumes. After all, 
the best text-book can serve only to introduce the 
student to the actual workers in his science, and the 
more of such contact the better. Dr. Findlay has very 
properly been liberal in the reproduction of figures, for 
the exposition of the phase rule would be a difficult task 
indeed without those graphical methods of represent- 
ation that have been so characteristic of its applica- 
tion. Tables of numerical data, taken from original 
papers, are abundant, and assist materially in the 
realisation of the actual experimental groundwork. 
As a result of the physicochemical activity of the last 
twenty years, and of the corresponding introduction of 
mathematical methods of treatment, more demands 
than formerly are made on the reasoning powers of 
the chemical student. This is probably true also in 
connection with the phase rule, but no one who con- 
siders the material collected by Dr. Findlay will doubt 
that the application of these exact methods has secured, 
a rich harvest of coordinated knowledge. 
Cares 
OUR BOOK SHELF. 
Notes on Electric Railway Economics and Preliminary: 
Engmeering. By W. C. Gotshall. Pp. iv+25r. 
(New York: McGraw Publishing Co., 1903.) 
Engineering Preliminaries for an Interurban Electric 
Railway. By E. Gonzenbach.- Pp. 71. (New 
York : McGraw Publishing Co., 1903.) 
THE economic side of engineering is one which the 
student is generally left to pick up as best he can on 
his way through life. Little attention is paid to it as 
a rule in the course of his technical training, and it 
is not until he starts on practical commercial worl: that 
he begins to realise that pounds, shillings and pence 
enter as much into the engineer’s formula as the 
fundamental units of length, mass and time. These 
two books should be very useful, therefore, not only to. 
the budding electric railway engineer, but also to all 
students of engineering, as serving to show the many 
