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JANUARY 22, 1914 | 
NATURE 
377 
THE CASE AGAINST RELATIVITY. 
Die Physik der bewegten Materie und die Rela- 
tivitatstheorie. By Dr. Max B. Weinstein. 
Pp. xii+424. (Leipzig: J. A. Barth, 1913.) 
Price 17 marks. 
ae general theories have suffered more at 
the hands of their own exponents than the 
principle of relativity. The call to reconsider our 
preconceptions as to the measurement of space 
and time, sounded by Einstein in 1905, was the 
signal for many self-confident minds to reconsider 
everything, and a flood of literature appeared in 
which it was difficult to find any real sense of 
physical reality. ; 
It was given to Minkowski to express the funda- 
mental idea of the principle in a form which, while 
severely mathematical and repulsive to many 
physicists’ minds, was concise and elegant, and 
furnished a powerful method of examining the 
consequences of the general hypothesis. It 
enabled him, for example, to modify the electro- 
magnetic equations for moving bodies as adopted 
by Lorentz in such a way as to conform exactly 
to the hypothesis of relativity, while agreeing with 
them to the degree of approximation to which 
they were experimentally verifiable. 
But beyond this Minkowski’s method opened the 
way for a rediscussion of the foundations of 
dynamical theory, and here its anticipations are 
beyond the. reach of experiment, and jn this 
region particularly have many writers lost touch 
with reality. 
In the work before us Dr. Weinstein tries to 
check this enthusiasm, and to compare critically 
the outcome of Minkowski’s theory, which may 
be looked upon as a descendant of the electro- 
dynamics of Lorentz, with the earlier work of | 
Maxwell and Hertz, and with what experimental 
evidence is avaiiable. 
His main conclusion is that the experimental 
basis of the principle of relativity is so meagre 
as scarcely to justify its adoption and application, 
although his admiration for the work of Minkowski 
is sO great that he dedicates the volume to his | 
memory. IT urther than this, Dr. Weinstein is not 
entirely prepared to admit the theory of Lorentz as 
a necessary correction to the Maxwell-Hertz theory, 
being dissatisfied with the conclusiveness of the 
experiments of Wilson and Ejichenwald in favour 
of the former, and while deprecating the multi- 
plication of theories, he suggests yet another modi- 
_ fication of the Hertz theory to explain the supposed 
_ discrepancy between it and the facts of aberration 
and of the Fizeau experiment. 
Some of the criticisms raised, however, are 
singularly unconvincing. The validity of the 
NO. 2308, VOL. 92] 
Michelson-Morley experiment is questioned on the 
ground that the origin of the interference figure 
which was actually observed is not explained, 
although no doubt is thrown on the fact that the 
figure did not change when the apparatus was 
rotated. The case made out against Einstein’s 
addition equation which is fundamental to the whole 
theory of relativity seems to the present writer to 
he lacking in logical accuracy, and tends to 
strengthen the impression that the author set out 
on the task of writing this large volume with a 
mind not entirely free from prejudice against what 
he terms ‘“‘an impatience which almost bars the 
progress of science.” 
But one is tempted to ask whether to cling tena- 
ciously to the conception of the azther formulated 
by Hertz, or even to the immovable zther of 
Lorentz, is not to place at least as great a barrier 
in the forward path as to search out with 
enthusiasm the consequences of an idea which 
is at least to an equal degree supported by, and 
the outcome of, experiment, and must in 
any case leave an enduring impression on our 
views as to the nature of physical magnitudes, in 
particular of space and time, as primary elements 
of thought. 
REFLEX ACTION. 
(1) Irritability: A Physiological Analysis of the 
General Effect of Stimuli in Living Substance. 
By Prof. Max Verworn. Pp. xii +264. (London : 
Oxford University Press; New Haven: Yale 
University Press, 1913.) Price 15s. net. 
(2) Studies on the Influence of Thermal Environ- 
ment on the Circulation and the Body-Heat. By 
| E.R. Lyth. Pp. vi+72. (London: John Bale, 
Sons and Danielsson, Ltd., 1913.) Price 2s. 6d. 
| net. 
Pin) HIS book is the outcome of the series 
of lectures given by Prof. Verworn 
under the Silliman Foundation of the University 
of Yale in 1911. Prof. Verworn has summarised 
the results of the investigations carried out by 
his co-workers and himself during the past twenty 
years, and in his preface he claims that he here 
presents “a uniform exposition of the general 
effects and laws of stimulation in the living sub- 
stance.” The book is certainly wide in scope, 
and is divided into nine chapters. The first of 
these is very interesting, as it deals with the his- 
torical aspects of the question, full credit being 
given to Francis Glisson as the founder of the 
doctrine of irritability. The subsequent lectures 
deal with the quality of the stimulus; ” the effects 
of stimulation, in which Prof. Verworn’s well- 
| known views on the so-called metabolic equi- 
i) 
