Marcu 14, 1907 | 
INA TO REE 
versity of Amsterdam, and this chair he held until 
the time of his death. 
In the Dutch universities seven years is the mini- 
mum period of study required for graduation, and 
the last of these is devoted to original research. 
The work undertaken by Roozeboom on the hydrates 
of the halogens and their hydrides led him at once 
to the problems with which his name will always be 
associated. 
In the course of his experiments he came upon 
phenomena which he was unable to explain. At that 
time the conditions which determine equilibrium in 
chemical systems were little understood by chemists. 
About ten years before, the American physicist, 
Willard Gibbs, had developed a theory of equilibrium 
between materials in contact which was completely 
independent of all assumptions as to the nature of 
matter or as to molecular structure. Given a system 
constituted of homogeneous portions (phases, as they 
are called, P in number) separated from each other 
bv definite surfaces of contact, and made up of con- 
stituents (components, as they are termed, C in 
number) the amounts of which present in the system 
can alter independently of the others, Gibbs had 
shown that, considering only the temperature and 
pressure under which the system exists and the con- 
centration of the components, the number F of the 
latter conditions (degrees of freedom, as they are 
called) to which arbitrary values must be assigned 
to describe the svstem perfectly are given by the 
expression F=C—P+2, this numerical relationship 
being known as the ‘“ phase rule.” 
Gibbs had published his results in a journal not 
widely circulated—the Transactions of the Connec- 
ticut Academy. They were, moreover, presented in a 
mathematical form unfamiliar to chemists, and had 
consequently remained scarcely noticed all these 
vears. Prof. van der Waals, to whom Gibbs's work 
was known, hearing of Roozeboom’s difficulty. sug- 
gested to him that this mode of regarding equilibrium 
might throw light upon it. Roozeboom’s  philo- 
sophical mind at once grasped the immense possi- 
bilities of this new method of regarding problems of 
equilibrium, and from that time he occupied himself 
with brilliant success in working out its application 
to chemistry. 
The investigations of Roozeboom and of those 
whom he interested in this branch of physical 
chemistry have cleared up our ideas in a surprising 
way, and opened out fresh paths of inquiry in the 
attractive region which connects chemistry and 
physics. The great merit of first apolyine the phase 
rule in chemistry must be attributed to Roozeboom, 
and gives him a high place among the founders of 
the new chemistry. 
An account of the many applications of the 
phase rule to chemical problems was written by 
Roozeboom in his well-known book ‘‘ Die hetero- 
genen Gleichvewichte vom Standpunkte der Phasen- 
lehre,’’ of which two parts only have vet appeared. 
He had prevared all the necessary material, and was 
about to begin writing the third and concluding part 
at the time of his death. 
Apart from scientific work his life was uneventiul. 
His simplicity of character and extreme desire to do 
justice to every fellow-worker won him the affection 
of all who came to know him well. In 1890 he was 
made a member of the Royal Academy of Science 
of Amsterdam. Totally devoid of any trace of the 
advertising spirit. he received fewer public honours 
than might have been expected to follow his notable 
achievements. and evervone must feel regret that the 
scientific world did not in his lifetime more adequately 
recognise his services. Be Di Crattaway. 
NOWIOSO: VOL. 75) 
NOTES. 
THERE is every likelihood that Lord Lister’s eightieth 
birthday, on April 4, will be suitably celebrated by his 
friends and admirers. A committee is being formed, con- 
sisting of representatives of medicine and science, with 
a view to carry into effect a suggestion made, we learn 
from the British Medical Journal, by Dr. C. J. Martin, 
F.R.S., the director of the Lister Institute. Dr. Martin 
has proposed that the best form in which to convey to 
Lord Lister the admiration and regard of his fellow- 
workers and followers would be the re-publication of all 
his scientific papers, prefaced by a biography of Lister 
containing an account of the part he took in the develop- 
ment of present knowledge of infectious processes, and of 
his efforts to avoid wound infection, the successful result 
of which revolutionised surgery. Dr. Martin will be glad 
to receive at the Lister Institute, Chelsea Gardens, S.W., 
the names of persons who desire to participate in this 
happy idea. 
Science announces that the Rumford medal of the 
American Academy of Arts and Sciences ‘‘ for discoveries 
in light and heat ’’ has been awarded to Prof. E. F. 
Nichols, of Columbia University. 
Tue death is announced, in his seventy-fifth year, 
of Sir Thomas Hanbury, K.C.V.O., at one time of 
Shanghai, the founder of the Hanbury Botanical Institute 
at the Royal University, Genoa, and of the Museum 
Prehistoricum, near Mentone. 
WE learn from the Athenaeum that the third congress 
of the Prehistoric Society of France will be held at Autun 
on August 13-18. Excursions will be made to Macon, to 
Mont-Auxois (the ancient Alesia), to Mont-Beuvray (the 
ancient Bibracte), and to Solutré. Dr. Marcel Baudouin, 
21 rue Linné, Paris, is the secretary. 
PETITIONS in support of the Metric Weights and 
Measures Bill, which is down for second reading on 
March 22, are being signed by many public bodies and 
institutions throughout the country. Among the petitions 
already received by the Decimal Association for present- 
ation to the House of Commons is one signed by the 
headmaster and the whole teaching staff of Eton College. 
Tue model of the Channel Tunne! which was on view 
at Caxton Hall, Westminster, during last week was 
well patronised, and the voting of those who have in- 
spected it has resulted in a large majority in favour of 
the scheme. Tlie model is well made in sections, which 
show clearly the positions of the proposed tunnels in the 
chalk and the direction of the strata. An interesting point 
is the very slight variation of level which occurs at this 
part of the Channel bed. 
Tue death 
the Moscow 
finishing his 
obtained the 
is announced of Prof. Y. Y. Tswetkoff, of 
Petroffsky Forestry Institute. Soon after 
studies at the St. Petersburg University he 
degree of Master of Mathematics by a dis- 
sertation on surfaces subject to change without rupture 
or bend of their component parts. In 1864 he was com- 
missioned by the Department of Agriculture abroad, and 
on his return he became extraordinary professor of the 
Moscow Institute of Forestry and Agriculture. In 1873 
he became professor of mathematics at the Lycée. He 
read lectures also on physics and meteorology, and his 
auditorium was always crowded. In 1885 he retired owing 
to illness. He was most generous in helping poor students 
and others, and only after his death was it found that 
he had given away several thousand roubles in this way. 
