100 
NATURE 
[JANUARY 20, 1923 


Reference was made to the possible connexion 
between the molecular structure and the exhibition 
of anisotropic properties, and to the various theories 
that have been advanced to explain the peculiar 
properties of these somewhat unfortunately named 
liquids. 
Thursday’s activities were inaugurated by a lec- 
ture by the Master of Trinity on ‘‘ The Electron in 
Chemistry.’’ Sir J. J. Thomson apologised, as a 
physicist, for encroaching on the domain of the 
chemist, but added that the difference between 
chemistry and physics was due to want of knowledge, 
and that the problem of chemical combination was 
one of the most outstanding problems in physics. 
Dalton’s Atomic Theory, as such, took no account 
of the intrinsic structure of discrete particles, and 
the modern conception of the internal arrangements 
of the atom dated from the discovery of the electron 
in 1897. The necessity of postulating a central 
positive nucleus and the possible arrangements of 
electrons around this was then discussed, and with 
the aid of diagrams and data thrown on the screen 
Sir Joseph reviewed existing knowledge of atomic 
structure, adequately deduced the existence of two 
forms of nitrogen, and showed that electrostatic con- 
siderations limited the number of electrons in a stable 
ring to eight. The latter part of his paper was 
devoted to the fascinating but somewhat intricate 
problem of chemical combination and the idea of 
“activated ’’ molecules. 
In addition to these lectures members of the 
Association divided to hear the very interesting and 
amusing lecture on ‘‘ The Acoustics of Public 
Buildings,” by Mr. A. Wood, and a lecture, equally 
attractive in its illustration, on ‘‘ Coral Reefs in the 
Pacific,” by Mr. F. A. Potts. 
The scientific interests of the members were further 
selectively absorbed on Thursday by a lecture in 
the Anatomical Department by Dr. H. Hartridge 
on “ Physiological Limits to the Accuracy of Visual 
Measurements ’’—a lecture of great interest to 
physicists among others—proceeding simultaneously 
with a lecture by Mr. E. K. Rideal on ‘“ Mole- 
cular Orientation on Plane Surfaces’’: in this, 
interesting deductions were made from the assumption 
that surface energy effects are restricted to a film 
of unimolecular thickness. 
The visitors to the Cavendish Laboratory enjoyed 
Dr. Searle’s demonstration of novel methods of 
determining physical quantities as well as the exhibit 
of apparatus used by Maxwell, Raleigh, Kelvin, 
Stokes, and other pioneer physicists. Prof. Marr pre- 
faced-his conducted tour of the Sedgwick Museum by a 
short lecture on some geological considerations suit- 
able for school treatment, while demonstrations of 
great interest to those engaged in the teaching of 
science were set up in the laboratories devoted to 
chemistry, physical chemistry, metallurgy, botany, 
physiology, experimental psychology, zoology, miner- 
alogy, and in the new Department of Engineering. 
A conversazione in the Large Examination Hall 
on Thursday evening officially terminated the meet- 
ing (although the laboratories were opening on the 
Friday to provide further opportunities for those 
desiring to visit them): on this occasion Mr. R. E. 
Priestley lectured on “‘ Antarctic Exploration with 
Shackleton and Scott.’ Mr. Priestley’s amusing 
and thrilling lecture, accompanied by lantern illus- 
tration that won frequent applause, provided an 
appropriate conclusion to a richly stimulating 
meeting. 
It remains to be mentioned that well-known firms 
held an exhibition of books and apparatus in the 
Arts School. 
ASSOCIATION OF WOMEN SCIENCE TEACHERS, 
At the annual meeting of the Association of Women 
Science Teachers held at University College, London, 
on January 6, a report was received from the sub- 
committee appointed to investigate the possibility of 
getting into touch with Colonial and foreign teachers 
of science. An appeal was made for members to corre- 
spond with teachers in other countries, and especially 
to send scientific journals to them. It is hoped that 
this movement may be further developed and become 
a useful part of international co-operation. 
In her presidential address Miss M. B. Thomas 
reviewed the criticisms which have recently been made 
against methods of teaching science in schools. She 
pointed out that it was impracticable, under existing 
conditions, to combine preparation for university 
entrance examinations with the wide and more 
generalised scientific instruction which was so gener- 
ally felt to be desirable, and pleaded for greater 
co-ordination between the subjects taught in schools. 
It was obvious that Science, and Languages, English, 
etc., could be mutually helpful, and that a closer 
co-operation between the mistresses teaching these 
subjects would result in advantage to all the sub- 
jects. 
: In the afternoon a large and appreciative audience 
heard a lecture by Dr. Dorothy Wrinch on “ Relativity 
and Scientific Method.”’ The lecturer gave an exposi- 
tion of this difficult subject which was so clear that 
even her non-mathematical hearers could follow the 
argument. She pointed out that the old dynamics 
had rested entirely upon the idea of measurement 
relative to a rigid and stationary standard, and that 
if the standard moved with a uniform velocity the 
position of affairs was altered. Examples were quoted 
in which the new equation for the composition of 
velocities has solved long-standing problems. Dr. 
Wrinch then proceeded to apply the principle to 
various kinds of scientific problems, which must not 
be approached on the assumption that the old laws 
would hold good but with the possibility in view that 
some law of the same nature as that of relativity 
might be the governing principle. To sum up, it 
must be remembered that if such apparent funda- 
mentals as time and distance have been shown to 
depend on velocity, then velocity is a relevant variable 
in all scientific method. 
Hail and Sleet in Meteorological Terminology. 
A? intervals there appears in the meteorological 
literature of various countries a discussion 
concerning the proper designation of the smaller 
and softer forms of hail which are common in all 
European countries during the winter or spring 
months. A recent contribution to the subject by 
R. Giacomelli, appearing in the issue for May and 
June of La Meteorologia pratica, the organ of the 
observatory of Montecassino, near Naples, is illuminat- 
NO. 2777, VOL. III] 
ing from certain points of view, without really 
settling the question. It is pointed out that the 
French and German terms, gvésil and gvdupel re- 
spectively, have the root idea of little pellets or 
grains, and that the real Italian equivalent, gragnola, 
is meteorologically a better descriptive term since it 
means “ little hail.’’ In full keeping, moreover, with 
the almost amusing richness of the Italian language 
in diminutive terms, one may use in place of gragnola 
