278 
Sir James Dewar, F.R.S. (Copley Medal). 
The scientific work of Sir James Dewar covers a 
wide field. By applying his ingenuity to problems of 
practical and theoretical importance, he has obtained 
results which have contributed. largely to modern pro- 
gress in physics. His early work dealt with organic 
chemistry, the nature and properties of the picoline 
and quinoline bases, and he investigated the properties 
of Graham’s hydrogenium. He made a study of the 
explosion of gaseous compounds, and he was asso- 
- ciated with Sir Frederick Abel in the introduction of 
cordite. Experiments on electro-photometry at one 
time engaged his attention, and he carried through 
some researches on the physiological and chemical 
efficiency of light, In conjunction with Prof. Liveing 
he published many results of spectroscopic investiga- 
tions, and afterwards devoted considerable time to the 
spectroscopic examination of the various gaseous con- 
stituents separated from the atmosphere. 
Sir James Dewar’s best-known recent work is con- 
nected with low temperatures and the liquefaction of 
gases, His introduction of the vacuum flask and his 
discovery of the power of gaseous absorption of char- 
coal at low temperatures rendered possible his investi- 
gation of the properties of many liquefied gases. He 
was the first to succeed in solidifying hydrogen. 
Helium was then the only gas which had resisted 
liquefaction. Sir James Dewar foretold how this 
refractory gas might be obtained in liquid form, and 
the efficacy of the method was verified by Dr. H. 
Kamerlingh Onnes, who, in 1908, obtained liquid 
helium, and reached the lowest known temperature 
(about 3° abs.). Sir James Dewar’s experiments in 
calorimetry and the electrical resistance of metal at 
low temperatures have opened a wide field of research. 
Prof, William Henry Bragg, F.R.S. (Rumford Medal). 
Prof. Bragg has been continuously engaged since 
1904 in researches into the nature and properties of the 
rays from radio-active bodies of other ionising radia- 
tions. Using new methods in the study of the ionisa- 
tion of gases by @ rays which greatly simplified the 
experimental conditions, he investigated the distribu- 
tion of the ions produced along the path of an a particle 
through a gas. These experiments threw an entirely 
new light.on the nature of the absorption of @ rays 
by matter, and proved that the a rays resulting from 
each radio-active transformation have a definite char- 
acteristic range, depending on the initial velocity. 
These investigations (in which he was assisted by 
Kleeman) formed one of the most important advances 
in our knowledge of the properties of these rays since 
their discovery. 
Prof. Bragg also made important contributions to 
‘our knowledge of the nature and properties of 8 rays 
and kathode rays, and especially of their relation to 
y rays and Rontgen rays. He attacked the problem of 
the nature of the process of ionisation by X-rays and 
y rays and put forward the view, now generally 
accepted, that the ionisation is entirely secondary and 
due to the corpuscular rays produced by the primary 
radiations. His Bakerian lecture (1915) contains an 
investigation on the reflection of X-rays from crystals, 
which has led to most important and novel results. 
Dr. John Scott Haldane, F.R.S. (Royal Medal). 
Dr. Haldane is awarded a Royal medal on account 
of the important contributions he has made to physio- 
logy, especially on the subject of respiration. ~ His 
study of the conditions of combination of carbon 
monoxide with hemoglobin have been fruitful in many 
directions. They led him to the investigation of gas 
-explosions in coal mines, which has had important 
NO. 2458, vor. 98] 
NATURE 
[DECEMBER 7, 1916 
results in the saving. of life in mines. They also. led 
to the discovery of methods for the determination of 
the oxygen tension in the blood afd of the total volume 
of the circulating blood in man, which have had wide 
clinical applications. , 
Dr. Haldane has also studied the effect of high 
temperatures under varying conditions of moisture on 
the human body, and was the first to lay down the 
definite conditions under which it is possible to with- 
stand or to work in high temperatures. The greater 
number of his papers, and those of his pupils, refer 
to the conditions of activity of the respiratory centre. 
He was the first to demonstrate beyond disput the all- 
important part played by the tension of carbonic acid 
in the blood in the regulation of the respiratory move- 
ments, and to elucidate the chemical  self-steering 
mechanism by means of which the pulmonary ventila- 
tion is adjusted to the respiratory needs of the body 
and to the activities of the animal. The knowledge 
obtained in these researches has enabled him to lay 
down the conditions which must be observed for the 
preservation of life among divers, and to elucidate the 
phenomena of mountain sickness and of acclimatisa- 
tion-to high altitudes. . 
Prof, Hector Munro Macdonald, F.R.S, (Royal Medal). 
A Royal medal is awarded to Prof. H. M. Macdonald 
on the ground of his contributions to mathematical 
physics. Prof, Macdonald has been engaged continu- 
ously in original research for the last twenty-five years, 
and in that time has produced many notable memoirs 
and one remarkable book (‘‘ Electric Waves,’? Cam- 
bridge, 1902). His work extends over a wide tange: 
hydrodynamics, elasticity, electricity, and optics, and 
branches of pure mathematical analysis which have 
applications to these subjects, especially the theory of 
Bessel’s functions, Among the papers of more dis- 
tinctly physical character, perhaps the most important 
are the series of papers treating of the theory of diffrac- 
tion, and especially the diffraction of electric 
waves by a large spherical obstacle, a problem 
which is of especial importance in connection 
with the theory of the transmission over the earth’s 
surface of the waves utilised in wireless telegraphy. 
He was the first mathematician to attaclx this problem, 
and also the first to obtain the correct solution. The 
interval between the first attack and the final conclu- 
sion was about eleven years (1903-14), and the discus- 
sion which took place in the meantime attracted con- 
tributions from some of the most eminent mathe- 
maticians of the dav, including such authorities as 
Lord Rayleigh and the late Henri Poincaré. . 
Henri Louis le Chatelier, For. Mem. R.S. (Davy 
Medal), 
M. le Chatelier, successor to Moissan at the Sor- 
bonne, is the most distinguished living French chemist. 
His name will always remain associated with impor- 
tant discoveries in several divisions of chemistry. In 
co-operation with M. Mallard, he was the author of 
an elaborate investigation on the ignition and explo- 
sion of gaseous mixtures, in which several principles 
of fundamental importance were established. As the 
result of much investigation he introduced the le 
Chatelier thermo-couple, and inaugurated a new period 
in the measurement of high temperatures. M. le 
Chatelier was one: of the pioneers of micrometallo- 
graphy, and one of the first to introduce exact methods 
and clear ideas into the science of industrial. silicates. 
His views on the relation of science to industry and 
on the teaching of chemistry, which command great 
attention in France, are exemplified in his highly 
| original book ‘*‘Le Carbone.” 
