62 president's address — section b. 



may bring' into operation the vigorous action of the httle 

 chlorine molecule — an instance of the phenomenon of that 

 subject of solution which is profoundly interesting the minds 

 of the chemists of the present day. 



Now, as the source of the world's chlorine supply is the 

 common salt we see on our dinner-tables every day, this 

 familiar and salutary article must become an object of 

 absorbing interest. Strange as it may appear to many, it is 

 hardly too much to say that the phenomenon presented to us 

 of a spoonful of salt dissolving in a tumbler of water is under 

 close observation and forms the subject of investigation of 

 the best chemical philosophers of our age. 



It may also seem a strange and far-fetched idea, yet the 

 attention now bestowed on the physical and chemical pro- 

 perties of the molecule in solution must eventually contribute 

 to the perfecting of new methods of separating metals from 

 other elements with which they are associated in the ore. 

 Leaving the practical side of the subject for a time, let us see 

 what is being done in this interesting domain of molecidar 

 mechanics, — let us track the chlorine molecule into space. 



He who surveys the ever-widening boundary of modern 

 chemistry cannot fail to be impressed with the increasing 

 amount of attention bestowed on physical and general 

 chemistry. It would seem as though a reaction had set in : 

 instead of the appalling host of carbon derivatives, Avhich 

 no man can number, endless as they seem in their protean 

 permutations, we see a desire on all hands to know more of 

 the varying phases of matter which were formerly passed by 

 as trivial or commonplace ; to picture the atom in space ; to 

 form clearer conceptions of the rushing together of atoms in 

 the act of combination, — in a word, to know something more 

 definitely about chemical action. Thus am I led on to the 

 subject of the molecule per 'se — the free ion — the whirling, 

 eddying, ether-embedded molecule. 



Our present position finds us in possession of the well- 

 established — may I not say, the impregnable — theory of an 

 all-pervading ether describable as an elastic solid endowed 

 with a great degree of rigidity. From the time of Young 

 onwards this working hypothesis has commanded the assent 

 of all thinking men, confirmed and strengthened as it is by 

 the classic and firmly-founded work of Sir William Thomson, 

 and others who have approached the subject from all sides. 



Clearer perceptions also prevail with regard to the dis- 

 continuous or heterogeneous nature of matter even of those 



