202 NATURE 
(4) V. v. Richter’s Chemie der Kohlenstoffverbind- 
ungen oder organische Chemie. Elfte Auflage. 
Zweiter Band. Carbocyclische und _hetero- 
cyclische Verbindungen. Neu bearbeitet von 
Dr. Richard Anschutz. In Gemeinschaft mit 
Dr. Hans Meerwein. Pp xxii+1048. (Bonn: 
Friedrich Cohen, 1913.) Price 26 marks. 
(5) Traité Complet d’Analyse Chimique Appliquée 
aux Essais Industriels. By Prof. J. Post and 
Prof. B. Neumann. Deuxiéme Edition Fran- 
¢aise Entiérement Refondue par G. Chenu et M. 
Pellet. Tome Troisiéme. Second Fascicule. 
Pp. 465-903+v. (Paris: A. Hermann et Fils, 
1913.) Price 15 francs. 
(6) Traité de Chimie Minérale. By H. Erdmann. 
Ouvrage traduit sur la 5e édition allemande par 
Prof. A. Corvisy. Tome Premier. Introduction 
a la Chimie et Métalloides. Pp. iv+559. 
(Paris: A. Hermann et Fils, 1913.) Price 12 
francs. 
(7) Laboratory Text-Book of Chemistry. By V. 
Seymour Bryant. Part 1. Pp. vi+246. 
(London: J. and A. Churchill, 1913.) Price 4s. 
net. 
(1) HOSE who have read Dr. Findlay’s book 
on the phase rule will have formed 
great expectations of his promised monograph on 
osmotic pressure, and we believe they will not be 
disappointed. The expression osmotic pressure of 
a solution has become a familiar one both to 
chemists and biologists, though, as Dr. Findlay is 
careful to point out, it is incorrect. A solution 
does not in itself have any osmotic pressure, the 
term being loosely used to denote the mechanical 
pressure which would be produced if the solution 
were separated from the pure solvent by a mem- 
brane which was permeable only to the solvent. 
The confusion of thought which has arisen in 
connection with the subject, especially amongst 
the biologists, is unfortunately very considerable, 
so that Dr. Findlay’s clear treatise comes at an 
opportune moment and should be widely read. 
Although necessarily mathematical in parts, it is 
not unduly so, even for the biological reader. 
The author shows himself to be no bigot in 
favour of the extreme views of the German 
physical-chemical school, and his chapter on the 
cause of osmosis and the action of the semi- 
permeable membrane reaches a high standard. 
Regarded from the biological side, the subject 
of osmosis is one in which we are on the eve of 
important developments requiring interpretation in 
the broadest possible manner. In the past the 
tendency has been to give too little attention to 
the chemical meaning of the osmotic phenomena, 
but this error is avoided in the present work. 
The work of Lord Berkeley in this country and 
NO. 2296, VOL. 92] 
[OcToBER 30, 1913 
that by Morse in America is described at length 
and its bearing on the general theory of ideal 
solutions discussed‘in a separate chapter. Em- 
phasis is laid on the thermodynamic equation 
connecting the osmotic pressure with the vapour 
pressure of solutions. 
(2), (3) Chemical monographs are evidently 
fashionable, and the success of the biochemical 
series edited by Dr. Plimmer and the inorganic 
series for which Dr. Findlay is responsible has 
inspired others to imitate them. The new series 
for which Dr. Cumming is sponsor are, however, 
of a different type and can scarcely lay claim to 
the title monograph—indeed, the use of the term 
is misleading. They are essentially summaries 
intended for advanced students with the examina- 
tion bugbear in front of them, and though no 
doubt they will be very useful, they are in no 
way authoritative in the same sense as the other 
monographs to which reference has been made. 
However, they are well printed and convenient in 
size and price, and should prove very popular 
among students. 
No. 1 in the series is Dr. Wren’s essay on the 
organometallic compounds of zinc and magnesium. 
Though Grignard described the reaction which 
now bears his name so recently as 1g00, the 
method has proved so fruitful in effecting organic 
syntheses that their number is already legion, and 
the subject forms, we fear, a very favourite 
examination question—hence, no doubt, the motive 
and form of the present summary. The mode of 
using the reagent is first described, but the bulk 
of the book is devoted to the description, with 
copious formule, of the products formed by its 
aid. A few pages are devoted to the theory of 
the reaction. The final section deals with Blaise’s 
more recent applications of the organometallic 
derivatives of zinc, which afford reagents of less 
general activity and of greater ease of control. 
Dr. Wood’s summary of the chemistry of dye- 
ing is simply and clearly written and devoid: of 
technical terms, so that it should appeal to a 
wider public than the chemical student and, indeed, 
be in the hands of all practical dyers. The scheme 
followed is first to discuss the chemical composi- 
tion and properties of the textile fibres, then to 
deal with the classification and properties of dyes, 
and lastly with the nature of the dyeing processes. 
A small bibliography and index is attached. The 
author is to be congratulated on the clear way 
in which he has dealt with the rival theories of 
dyeing within a short space. 
(4) A new edition of Richter scarcely calls for 
criticism beyond the statement that the authors 
have maintained the standard of a work which has 
been indispensable to all students of organic 
