TRANSACTIONS OF THE SECTIONS. 
Srction-A.—MATHEMATICAL AND PHYSICAL SCIENCE. 
PRESIDENT OF THE Section.—Professor E. RutHerrorp, M.A., 
D.Sc., E.B.S. 
THURSDAY, AUGUST 26. 
The President delivered the following Address :— 
It is a great privilege and pleasure to address the members of this Section 
on the occasion of the visit of the British Association to a country with 
which I have had such a long and pleasant connection. I feel myself in 
the presence of old friends, for the greater part of what may be called my 
scientific life has been spent in Canada, and I owe much to this country 
for the unusual facilities and opportunity for research so liberally pro- 
vided by one of her great Universities. Canada may well regard with 
pride her Universities, which have made such liberal provision for teaching 
and research in pure and applied science. As a physicist, I may be 
allowed to refer in particular to the subject with which I am most inti- 
mately connected. After seeing the splendid home for physical science 
recently erected by the University of Toronto, and the older but no less 
serviceable and admirably equipped laboratories of McGill University, one 
cannot but feel that Canada has recognised in a striking manner the 
great value attaching to teaching and research in physical science. In 
this, as in other branches of knowledge, Canada has made notable con- 
tributions in the past, and we may confidently anticipate that this is but 
an earnest of what will be accomplished in the future. 
It is my intention to-day to say a few words upon the present position 
of the atomic theory in physical science, and to discuss briefly the various 
methods that have been devised to determine the values of certain funda- 
mental atomic magnitudes. The present time seems very opportune for 
this purpose, for the rapid advance of physics during the last decade has 
not only given us a much clearer conception of the relation between elec- 
tricity and matter and of the constitution of the atom, but has provided 
us with experimental methods of attack undreamt of a few years ago. At 
a time when, in the vision of the physicist, the atmosphere is dim with 
flying fragments of atoms, it may not be out of place to see how it has fared 
with the atoms themselves, and to look carefully at the atomic foundations 
on which the great superstructure of modern science has been raised. 
Every physicist and chemist cannot but be aware of the great part the 
atomic hypothesis plays in science to-day. The idea that matter consists 
of a great number of small discrete particles forms practically the basis 
of the explanation of all properties of matter. As an indication of the 
importance of this theory in the advance of science it is of interest to read 
