390 
NATURE 
[Marcu 24, 1923 

although there are several plates showing the power 
houses of Continental works. The account of the 
economic position of the industry is also too meagre 
to be of much use. The valuable part of the book 
consists of a long series of diagrams of mechanical 
properties of metal that has been subjected to various 
thermal and mechanical treatments, and of a corre- 
sponding series for certain of the light alloys and for 
the aluminium bronzes. Tensile strengths are given 
in metric and British units—an excellent practice. 
The lack of any theoretical discussion deprives 
these sections of much of their value. The ageing 
of duralumin and similar alloys is a puzzling pheno- 
menon when presented in the form of a mere record 
of tensile and hardness tests, but becomes comprehen- 
sible when considered in the light of microscopical 
and electrical evidence, and interpreted by means ot 
the theory of solid solutions. Most of the photo- 
micrographs represent the copper-aluminium alloys, 
commonly called aluminium bronzes. The writer 
appears to be unaware of the work that has been done 
in this country, at the National Physical Laboratory 
and at the Royal School of Mines, which has thrown 
so much light on the properties of this metal and of 
the light alloys. The book will be found useful chiefly 
for reference, when information is sought as to the 
strength, hardness, cupping quality, etc., of the alloys 
with which it deals. 
(2) The latest report of the Alloys Research Com- 
mittee is of a very different standard. The recent 
work carried out at the National Physical Laboratory 
has led to the preparation of several new alloys of 
technical importance, the most remarkable being the 
alloy “ Y,” which retains its strength and resistance 
to alternating stresses at elevated temperatures, and 
is also resistant to corrosion. This alloy contains 
copper, nickel, and magnesium. The report includes 
studies of the constitutional diagrams of several of 
the binary and ternary systems, and an investigation 
of the causes of age-hardening in aluminium alloys. 
In this connexion the importance of magnesium silicide 
as a hardening agent is shown, and the changes of 
hardness with time and temperature are correlated 
with the changes in solubility of this compound in the 
solid solution. The principal casting alloys are found, 
from measurements extending over long periods, to be 
stable in dimensions, and there is no doubt that these 
researches have added to the range of structural 
materials of high quality available to the engineer, 
and that a great future lies before light alloys, suitably 
heat-treated. The photo-micrographs illustrating the 
volume are remarkably clear, and their beauty will 
be appreciated by all who have had occasion to prepare 
these alloys for examination. Gre ae 
NO. 2786, VOL. I11] 

Our Bookshelf. 
Handbuch der biologischen Arbeitsmethoden. Heraus- 
gegeben von Prof. Dr. E. Abderhalden. Abt. V: 
Methoden zum Studium der Funktionen der einzelnen 
Organe des tierischen Organismus. Teil 3A, Heft 3, 
Lieferung 69: Entwicklungsmechanik. Pp. 441- 
538. 630marks. Abt.IX: Methoden zur Erfor- 
schung der Leistung des tierischen Organismus. Teil 
1, Heft 2, Lieferung 71: Allgemeine Methoden. 
Zoologische allgemeine Methoden. Pp. 97-438. 
2160 marks. (Berlin und Wien: Urban und 
Schwarzenberg, 1922.) 
Tue number of subjects included in these two parts of 
Abderhalden’s great “* Handbuch ” precludes, in a short 
notice such as the present, anything beyond a mention 
of the chief topics discussed. 
Lieferung 69 is devoted to ‘‘ Entwicklungsmechanik.” 
Here Herbst discusses methods of artificial partheno- 
genesis ; Giinther Hertwig, the method of irradiation of 
the germ-cells by radium and Réntgen rays ; Romeis, 
the technique of investigations on the action of organic 
extracts, such as muscle, thyroid, and suprarenal ex- 
tracts, on invertebrates, anuran tadpoles and urodele 
larve ; and Braus, the methods of tissue cultures im 
vitro. 
Lieferung 71 is more extensive. Przibram is re- 
sponsible for a chapter of about 90 pages on “ Living 
Material for Biological Investigations.” In this he 
considers the choice of species to be employed in bio- 
chemical researches, how and whence to obtain them, 
their transport and maintenance, the terrarium, the 
aquarium (including the setting up and aeration of sea- 
water aquaria), and the insectarium. In addition, 
there is given some account of the application of 
chemical agencies, the means of obtaining and main- 
taining various degrees of moisture and of pressure, the 
application of mechanical agencies, and the alteration of 
the action of gravity. The subjection of the animals 
to the action of electricity and of magnetism, the 
application of heat and of light (measurement of the 
degrees of light, coloured light, ultra-red and ultra-violet 
rays), and the isolation and marking of the subjects of 
the experiments are also dealt with. 
Two sections of 4o pages each are devoted to 
methods of preservation of zoological preparations 
and to zootomical technique. The methods of re- 
construction by means of wax or paper plates are 
fully explained, while shorter but useful sections deal 
with the preparation of simple text-figures by the 
author, and with the production of transparent museum 
preparations. 
Oxidations and Reductions in the Animal Body. By 
Dr. H. D. Dakin. Second edition. (Monographs on 
Biochemistry.) Pp. ix+176. (London: Longmans, 
Green and Co., 1922.) 6s. net. 
THE complex chemical compounds taken as food by 
animals are not brought by a single reaction of oxida- 
tion to their final states of water, carbon dioxide, and 
urea, They pass through many intermediate stages, 
which are of great interest and importance, not only 
from the purely chemical aspect, but also on account of 
the fact that many of them play a part in the production 
ed 
