PRESIDENT'S ADDRESS. 1 5 



CHEMISTRY. 



A good deal of experimental work has lately been done in 

 connection with the structure of the atom and similar subjects, 

 but the exceedingly small size of the objects dealt with makes 

 the experiments very delicate and the results perhaps rather 

 theoretical. The sort of size of the constituent parts of the 

 atom, which is supposed to be made up of hydrogen atoms 

 and electrons, is a fraction of an inch represented by unity as 

 the numerator and a number of about 17 figures as the 

 denominator, a smallness immensely beyond the power of the 

 strongest microscope. The basis of these experiments is the 

 observation of the particles thrown off by radium and their 

 movements in connection with other particles. The a particles 

 which proceed from radium are the nuclei of atoms of helium, 

 the ft particles being electrons. It is now reported that the 

 Chilian supply of nitrate of soda upon which we have hitherto 

 relied for the nitrates we required, is not nearly exhausted as 

 stated, but sufficient for 200 years, which fact if confirmed may 

 prevent the development of methods of nitrate production 

 which are carried out in some countries where much more 

 water power is available for the purpose than in Great Britain. 

 This would be a disadvantage, as it is most desirable that we 

 should be self-supporting in all important things, as far as 

 possible. The passing of the Dye stuffs bill will it is hoped 

 give an impetus to the manufacture of dyes in this country. 

 An agent greatly used during the war for sterilising water, was 

 chloride of lime. I have used this for many years for destroying 

 the small crustaceans and insect larvae which are often so 

 abundant in rain water. The former are killed by a small 

 dose, the latter require a considerably stronger one. 



ENGINEERING. 



One of the most wonderful inventions that has lately come 

 into notice is the optophone, an instrument by means of which 

 the blind are enabled to read ordinary print. In this, by the 

 use of selenium cells, different sounds are produced by different 



