NOVEMBER 10, 1899. ] 
Professor Auwers one of the secretaries 
of the Berlin Academy, occupied the chair, 
and the success of the meeting was largely 
due to the extreme ability and tact, com- 
bined with judicious firmness, with which 
he conducted the proceedings. Besides 
showing himself a master of the three 
languages—German, French and English— 
used in the debates, he was thoroughly in- 
formed on every point which came up for 
discussion. Fortunately, all the delegates 
appeared to be actuated by the desire to 
cooperate, and there was little difficulty in 
framing statutes which all were prepared to 
accept. 
The immediate outcome of the conference 
has been that it is resolved to found an in- 
ternational union of the principal scientific 
and literary bodies of the world, the object 
of which will be to initiate or promote 
scientific enterprises of general interest re- 
commended by one or more of the asso- 
ciated bodies, and to facilitate scientific 
intercourse between different countries. It 
is to be known as the International Asso- 
ciation of Academies. A number of im- 
portant bodies besides those represented at 
Wiesbaden are to be invited to join. Gen- 
eral meetings of delegates from the various 
constituent academies are to take place, as 
a rule, at intervals of three years, but the 
interval may be varied and special meet- 
ings held, if necessary. The Royal Society 
had proposed, prior to the conference, that 
the first general meeting should be held in 
Paris next year. At the general meetings 
two sections will be constituted, one deal- 
ing with mathematics and the natural 
sciences, the other with arts and philosophy. 
A council is to be appointed which will 
carry on the business in the intervals be- 
tween meetings. The formation of com- 
mittees of experts to initiate and promote 
scientific investigations of international im- 
portance is also contemplated. 
It remains to be mentioned that the Ber- 
SCIENCE. 
685 
lin Academy had also arranged for the 
entertainment of the delegates at the close 
of the debates. On the Monday evening 
they were invited to attend a performance 
of Lortzing’s opera Undine, and on the 
Tuesday they were entertained at dinner in 
the Kurhaus. On the latter occasion Pro- 
fessor Virchow occupied the chair, and 
opened the proceedings by toasting the 
delegates generally ; he was followed by 
Professor Darboux, of Paris, who proposed 
the health of the Berlin Academy, and in the 
course of the evening numerous other toasts 
were proposed by the delegates. 
SCIENTIFIC BOOKS. 
The Kinetic Theory of Gases. By S. H. BURBURY. 
Cambridge University Press. 1899. Pp. 157. 
Mr. Burbury has long been known as an 
occasional contributor to the Kinetic Theory of 
Gases. The first edition of Watson’s treatise 
on this subject, published in 1876, acknowledged 
the indebtedness of its author to him; and in 
that very interesting discussion of the Kinetic 
Theory which was begun at the Oxford meeting 
of the British Association in 1894 and continued 
for months afterwards in Nature, Mr. Burbury 
took a conspicuous part, appearing as the ex- 
pounder and defender of Boltzmann’s H-the- 
orem in answer to the question which so many 
have asked in secret, and which Mr. Culver- 
well asked in print, ‘What is the H-theorem and 
what does it prove’? Thanks to this discussion, 
to the more recent publication of Boltzmann’s 
Vorlesungen tiber Gas-theorie, and finally to this 
treatise by Burbury, this question is not so diffi- 
cult to answer as it wasa few yearsago; butitis 
probable that some readers of SCIENCE, even to 
this day, know less about the H-theorem than 
is contained in the following sketch of its 
history, which will serve to bring out one of 
the most interesting features of the book be- 
fore us : 
In 1860 Maxwell deduced from the laws of 
probability an expression for the final distribu- 
tion of components of velocity among the par- 
ticles of a gas consisting of very small elastic 
spheres having no action upon each other ex- 
