4 NATURE 
Mr. Phillips’s volume will be greatly appreciated 
not only by those who are connected with 
Alabama, but by all who are interested in the 
manufacture of iron and steel wherever it may be 
carried on. 
(2) Mr. Hudson’s book is one of a series of text- 
books which are described as “introductory to 
the chemistry of the national industries.” It is 
written in a clear and concise manner, and deals 
very ably with recent scientific investigations and 
theories regarding the constitution of iron and 
steel. The principles underlying the smelting of 
iron, the manufacture of wrought iron and steel, 
foundry practice, and such processes as case- 
hardening, welding, &c., are reviewed very briefly, 
but no attempt is made to treat these subjects 
from the manufacturing point of view, and this part 
of the book can scarcely be regarded as an intro- 
duction to the metallurgy of iron and steel, except 
for very elementary students. The book is in- 
tended primarily for those interested in the 
physico-chemical rather than the practical aspects 
of the subject, and this is clearly the intention 
of the author, who states in his preface that 
“practical details of the methods of production 
have been avoided almost entirely, in order that 
more attention may be devoted to such matters 
as an explanation of the constitution of steel and 
cast-iron, and the effects of mechanical and heat 
treatment on the properties of these alloys.” In 
the later chapters these subjects have been very 
completely dealt with, and, together with. the 
chapter on corrosion by Dr. Bengough, will be 
welcomed by many students of metallurgy. 
OUR BOOKSHELF. 
Ueber kausale und konditionale. Weltanschauung 
und deren Stellung sur Entwicklungsmechanik. 
By Wilhelm Roux, Pp. 66. (Leipzig: W. 
Engelmann, 1913.) Price 1.50 marks. 
Pror. Roux makes game of Prof. Verworn’s 
recent essay on the causal and the conditional out- 
look on the world, which was, we think, reviewed 
some months ago in Nature. What is true in 
Verworn’s essay is not new, and what is new is 
not true. The causal outlook, which has been in 
vogue “from the Stone age down to Verworn,”’ is 
not to be superseded by a crude ‘“conditionism.” 
What is sound in Verworn’s emphasis that the 
scientific task is to inquire into all the antecedent 
conditions is recognised by all investigators. The 
change proposed is verbal, for as soon as a process 
is set a-going, its conditions become active factors 
The complete conditions are the com- 
plete causes. Verworn lays great stress on what 
he calls the “effective equivalence” of the con- 
ditions of any process or result, but Roux cannot 
accept the phrase. Equally necessary the factors 
are, but certainly not equivalent. 
NO. 2288, VOL. 92| 
Or causes. 
[SEPTEMBER 4, I913 
In the study of development the specifitas 
potentiae of each of the various factors is well 
known. In vital processes the internal and the 
external conditions cannot be spoken of as equi- 
valent, as Verworn proposes. The constitution of 
an ovum includes factors which determine a 
certain, within limits, typical result; the external 
conditions of oxygen, warmth, moisture, and so 
on, activate and sustain the development. Thus 
Roux distinguishes between “determining” and 
“realising” factors, and says that it is nonsense 
to speak of their ‘‘ equivalence.” 
From time to time in his brilliant series of 
studies in “developmental mechanics’ Roux has 
given a causal analysis of the known factors in- 
volved, distinguishing, for instance, between in- 
ternal and external, determining and realising, 
necessary and “ 
is entirely opposed to the false simplicity which 
Verworn’s ‘‘conditionism” would suggest. 
There has been hard hitting on both sides, but 
perhaps it is instructive to remember that Ver- 
worn’s life has been largely spent in the study 
of metabolism, and Roux’s in the study of develop- 
ment—which is for him an “autopheenesis,” “a 
becoming-visible of ,manifoldness by the proper 
activity of the germ.’ J. °AGRES 
Brazil in 1912. By J. C. Oakenfull. Pp. viii+ 
498. (London: Robert Atkinson, Ltd., 1913.) 
Price 5s. = 
Tuis is the fourth annual edition of an excellent 
handbook on Brazil. As usual, it is well and pro- 
fusely illustrated, the large map of the country 
and the coloured frontispiece showing the precious 
stones of Brazil being especially good. The book 
deals in an interesting manner with the history 
and geography of Brazil; but the chapters on the 
anthropology and ethnography, the geology and 
paleontology, the mineralogy, and the agriculture 
of Brazil will appeal more directly to scientific 
readers. 
The book is intended for free distribution, but 
duplicate and trade copies can be obtained at aS : 
price stated. 
Teachers of geography will find it an interest- 
ing and valuable work of reference in the school — 
library. 
The Theory and Design of Structures. 
book for the Use of Students, Draughtsmen, 
and Engineers engaged in Constructional Work. 
By E. S. Andrews. Third edition. Pp. xii+ 
618. (London: Chapman and Hall, Ltd., 
1913.) Price 9s. net. 
Tue first edition of this book was reviewed at 
some length in the issue of Nature for March 18, 
1909 (vol. Ixxx., p. 64). The additions made to 
the present edition are incorporated in an appendix 
of some twenty-seven pages, and these include 
a note on Dr. Stanton’s experiments on wind 
pressure. The notation in the chapter on re- 
inforced. concrete has been made to agree with 
that proposed by the Concrete Institute, and 
numerous exercises have been added to the volume. 
not necessary” factors; and he 
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