THE PRESIDENTIAL ADDRESS. 7 
Lorentz; Hertz’s discovery of electro-magnetic waves ; the investigation 
of cathode rays by Lenard, and the elucidation of crystal structure by 
Bragg. 
It has seen, moreover, the invention of the telephone, the establish- 
ment of incandescent lighting, the electric transmission of force, the 
invention of the cinematograph, of wireless telegraphy, the application 
of the Réntgen rays, and the photographic reproduction of colour. 
In physical chemistry it has witnessed the creation of stereo- 
chemistry by Van t’Hoff and Le Bel, Gibbs’ work on the phase rule, 
Van t’Hoff’s theory of solutions, Arrhenius’s theory of ionic dissocia- 
tion, and Nernst’s theory of the galvanic cell. 
Such a list is far from complete, and might be greatly extended. 
But it will at least serve to indicate the measure of progress which the 
world owes to the development and application during the last fifty 
years of the two sciences—physics and chemistry—to which Lord 
Kelvin specially referred. 
The more rapid dissemination of information concerning the results 
of recent or contemporary investigation, which Lord Kelvin so strongly 
urged as ‘an object to which the powerful action of the British Asso- 
ciation would be thoroughly appropriate,’ has been happily accomplished. 
The timely aid of the Association in contributing to the initial expense of 
preparing and publishing monthly abstracts of foreign chemical 
literature by the Chemical Society is gratefully remembered by British 
chemists. The example has been followed by the greater number of 
our scientific and technical societies, and the results of contemporary 
inquiry in every important branch of pure and applied science are now 
quickly brought to the knowledge of all interested workers. In fact, 
as regards the particular branch of science with which I am more 
directly concerned, the arrangements for the preparation and dissemina- 
tion of abstracts of contemporary foreign chemical literature are 
proving to be a veritable embarrassment of riches, and there is much 
need for co-operation among the various distributing societies. This 
need is especially urgent at the present time owing to the greatly 
increased cost of paper, printing, binding, and indeed of every item 
connected with publication, which expense, of course, ultimately falls 
upon the various societies and their members. The problem, which 
has already received some attention from those entrusted with the 
management of the societies referred to, is not without its difficulties, 
but these are not insoluble. There is little doubt that a resolute and 
unanimous effort to find a solution would meet with success. 
The present high cost of book production, which in the case of 
specialised books is about three times what it was in 1914, is exercising a 
most prejudicial effect upon the spread of scientific knowledge. Books 
on science are not generally among the ‘ best sellers.’ They appeal to a 
