JUNE 7, 1901.] 
freezing of the beet be brought about slowly, 
water may be drawn into the cavity from a 
considerable distance from cell to cell within 
the tissue. 
Certain strong non-poisonous solutions, when 
applied to the cut ends of the petioles of leaves, 
produce a similar translucent effect in the tissue 
of the blades of leaves, as is shown by the writer 
in a paper now in process of publication. 
JAMES B. DANDENO. 
BoTANICAL MusEUM oF HARVARD UNI- 
VERSITY, May 22, 1901. 
THE AMERICAN MATHEMATICAL SOCIETY. 
A PRELIMINARY circular, which has just ap- 
peared, describes the arrangements which have 
been made for the summer session of the Am- 
erican Mathematical Society to be held at 
Cornell University, Ithaca, N. Y., during the 
week beginning on August 19th. The meeting 
proper, for the transaction of business and the 
presentation of papers, will take place on the 
first two days, while the remainder of the 
week will be occupied by a colloquium. Two 
courses of lectures by Professor Oskar Bolza, 
of the University of Chicago, and Professor E. 
W. Brown, of Haverford College, are announced 
as. the basis for this colloquium, which will be 
the third organized by the society in connection 
with its summer meetings. Professor Bolza’s 
subject is ‘The calculus of variations, in par- 
ticular Weierstrass’s discoveries.’ The principal 
object of the course is to give a detailed ac- 
count of the solution of the simplest type of 
problems, in its historical development, with 
special emphasis upon the contributions of 
Weierstrass and his followers. A summary re- 
view of the peculiar features of the more general 
problems is also intended. Professor Brown 
will lecture on ‘Modern methods of treating 
dynamical problems and in particular the prob- 
lem of three bodies.’ The object of this course 
is to set forth some of the later attempts to 
introduce more rigor into the methods of solv- 
ing dynamical problems, mainly the researches 
of Poincaré. The course will be chiefly descrip- 
tive, in showing the principles of the methods, 
the mathematical difficulties which arise, and 
the results which have been obtained. Among 
the subjects treated will be the following: the 
SCIENCE. 
917 
various forms of the differential equations of 
dynamics, the existence of integrals, solutions 
by infinite series, periodic solutions, stability 
and instability. In neither course will special 
knowledge of the subject be presupposed. 
SCIENTIFIC NOTES AND NEWS. 
Dr. IRA REMSEN, professor of chemistry in 
the Johns Hopkins University since its founda- 
tion in 1876, has been elected president of the 
University. 
A COMMITTEE, consisting of Professors Ira 
Remsen, J. S. Ames and W. H. Welch, has 
been appointed at the Johns Hopkins Univer- 
sity to arrange a memorial to the late Professor 
Henry A. Rowland. 
M. LAvERAN, the French army surgeon who 
discovered the malaria parasite, has been 
elected a member of the Paris Academy of 
Sciences in the section of medicine, filling the 
vacaney caused by the death of M. Potain. In 
the third ballot M. Laveran received forty, and 
M. Ch. Richet twenty-six, votes. 
AT a recent meeting of the National Geo- 
graphic Society, the by-laws were so changed 
as to merge into the single class of ‘members’ 
the two classes hitherto designated ‘resident 
members’ and ‘non resident members,’ and 
also to increase the board of managers from 18 
to 24, including six not resident in the District 
of Columbia. The board has now been com- 
pleted by the election of the following non- 
resident members: Professor William M. Davis, 
Cambridge; Mr. Russell Hinman, New York 
Professor Angelo Heilprin, Philadelphia; Dr. 
Daniel C. Gilman, Baltimore; Professor Rollin 
D. Salisbury, Chicago, and Professor George 
Davidson, San Francisco. 
Dr. G. A. HANSEN, of Bergen, the discoverer 
of the bacillus of leprosy, will celebrate his 
sixtieth birthday in July, and it is proposed to 
present him with an international testimonial 
made up of small subscriptions. These may 
be sent to Dr. Sandberg, Bergen. 
PROFESSOR EDWARD F. Mor ey, of Adelbert 
College, has been appointed a delegate from 
the United States to the International Confer- 
ence of Weights and Measures, which is to be 
held in Paris during September. 
