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NATURE 
[May 12, 1923 
Current Topics and Events. 
THe growth of our knowledge of stellar physics 
during the present century has been surprisingly rapid. 
It has arisen by combining the results of researches 
of most varied kinds. The older astronomy of position 
has afforded the data for the positions, distances, and 
motions of the stars, which were a preliminary to the 
establishment of the theory of giant and dwarf stars, 
and also to the detection of the possibility of finding 
parallaxes by the spectroscope, and so distinguishing 
the giants from the dwarfs. In another field, the 
discovery of radium, and radio-activity generally, has 
revolutionised ideas on the nature of the atom, and 
led to the detection of analogies between chemistry 
and dynamics. Prof. Eddington, whose lecture on 
‘“The Interior of a Star,’ delivered at the Royal 
Institution on February 23, is printed as a supplement 
to the present issue, is one of the leading pioneers in 
this field. His earliest astronomical work was con- 
cerned with stellar distances and proper motions ; 
but he has recently worked more on the physical 
side. Prof. Eddington was one of the first to point 
out the importance of light pressure in causing the 
distension of giant stars, and also to suggest that 
the immense duration of their output of energy is 
explicable by their drawing on the store of energy 
in the atom. This was first offered as a tentative 
explanation, but Prof. Eddington now makes it 
definitely. A remarkable confirmation of the correct- 
ness of the accepted views on stellar physics was 
afforded by the close agreement of the diameter of 
Betelgeuse, as given by the interferometer, with that 
deduced from the study of the distribution of energy 
in the spectrum, which led to a value of the tempera- 
ture and surface brightness. 
THE approaching visit to London of Prof. H. A. 
Lorentz, of the Teyler Institute at Haarlem, and 
the University of Leyden, is being eagerly awaited 
by physicists. Prof. Lorentz is the doyen of mathe- 
matical physicists. In 1880 he developed from 
electromagnetic theory a connexion between re- 
fractive index and density (known by his name), 
which holds good through great ranges of density, 
though requiring a small correction for extreme states 
as recent experiments on carbon dioxide have demon- 
strated. At the present time, Prof. Lorentz is 
acclaimed in the main for the fundamental work he 
has done in connexion with the electromagnetics of 
moving bodies. In this work he has served as an 
intermediary between the old electromagnetics and 
the modern doctrine of relativity. Einstein’s results 
agree mainly (though not exactly) with those which 
Prof. Lorentz had obtained, ‘‘the chief difference 
being that Einstein simply postulates what I have 
deduced with some difficulty and not altogether 
satisfactorily from the fundamental equations of 
the electromagnetic field’ (Lorentz). Prof. Lorentz 
contributed to the explanation of the magneto optic 
phenomena discovered by Zeeman and others. “I 
may refer in the first place to the intensely stimulating 
influence of H. A. Lorentz’s theories. It is difficult 
to find adequate words to express my indebtedness to 
NO. 2793, VOL. 111 | 



Lorentz’s personal inspiration and to his theories” 
(Zeeman). Prof. Lorentz visited the British Associa- 
tion at the Birmingham meeting in 1913, and made 
important and guarded contributions to the discussion 
on radiation and the quantum theory. His first lecture 
in London is at 5.30 P.M. on May 17, at University 
College, Gower Street. Admission is free, without 
ticket. Three other lectures by Prof. Lorentz, at the 
same place, have been arranged to be-delivered in the 
early part of June. He is also lecturing at Cambridge 
(Reid Lecture), at Manchester, and elsewhere. 
SHORTLY after the death of Dr. W. H. R. Rivers in 
June last, it was suggested that the eminence of his 
services to science should be recognised by some form 
of memorial; but it was not found possible to take 
any further steps at the time. A few of Dr. Rivers’s 
friends have now formed a small committee with the 
view of giving the proposal practical effect. Among 
those serving are: Sir Charles Sherrington, Sir William 
Ridgeway, Sir Humphry Rolleston, Sir James Frazer, 
Dr. Henry Head, Dr. A. C. Haddon, Mr. Henry 
Balfour, Prof. G. Elliot Smith, Dr. C. S. Myers, and 
Prof. C. G. Seligman. 
an appeal for subscriptions to a fund of which Dr. 
L. E. Shore of St. John’s College, Cambridge, acts as 
treasurer. The fund will be devoted to the pro- 
motion of those sciences in which Dr. Rivers was 
particularly interested, but the decision as to the 
manner in which this will be effected will rest with 
the subscribers, of whom a meeting will be summoned 
in due course. It is permissible to express a hope 
that the committee and subscribers will decide to 
devote the fund to some object which it is known 
that Dr. Rivers had closely at héart, such as, for 
example, the assistance of the publication of scientific 
memoirs for which ordinary scientific or commercial 
channels are not available on the ground of cost. 
DurinG the summer of 1922 a member of the 
Cambridge Natural History Society was in Vienna 
and made the acquaintance of Dr. Kammerer, who 
appeared to be willing to visit England, should an 
opportunity occur. After further correspondence 
with Dr. Kammerer, the matter was placed before 
the council of the society in March last, and it was 
then decided that Dr. Kammerer should be invited 
in the name of the society to give a lecture at Cam- 
bridge. The invitation was accepted by Dr. Kammerer, 
and the lecture is published elsewhere in this issue. 
All expenses of the journey were provided for by 
contributions from members of the society, and on 
April 25 Dr. Kammerer arrived in England, and has 
since been the guest of the society. 
Tue Croonian lecture of the Royal Society will be 
delivered on June 21 by Dr. F. F. Blackman, who 
will take as the title of his lecture ‘‘ Plant Respira- 
tion as a Catalytic Process.”’ 
Dr. Joun Patipin, director of the Botanical 
Garden at Batoum, has accepted the post of assistant 
to the museum director in the principal botanical 
This committee has now issued 
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