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SCIENCE 



[N. S. Vol. XL. No. 1031 



This speaks well for the universities and 

 their staffs, who have so successfully set 

 the example of scientific investigation to 

 their pupils. 



Eadio activity and kindred phenomena 

 seem to have attracted them most of late 

 years, and it would perhaps have been ap- 

 propriate to have shortly reviewed in this 

 address our knowledge in these subjects, 

 to which the sons of Australasia have so 

 largely contributed. 



Twenty-five years ago FitzGerald and 

 others were speculating on the possibility 

 of unlocking and utilizing the internal 

 energy of the atom. Then came the epoch- 

 making discovery of Becquerel, to be fol- 

 lowed by the brilliant work of Eutherford 

 and others showing us that no key was re- 

 quired to unlock this energy ; the door lay 

 open. 



We have still facing us the analogous 

 case of a hitherto untapped source of 

 energy arising from our motion through 

 the ether. All attempts, it is true, to real- 

 ize this have failed, but nevertheless he 

 would be a brave prophet who would deny 

 the possibility of tapping this energy de- 

 spite the ingenious theories of relativity 

 which have been put forward to explain 

 matters away. There is no doubt but that 

 up to the present nothing hopeful has been 

 accomplished towards reaching this energy 

 and there are grave difficulties in the way ; 

 but "Relativity" is, as it were, merely try- 

 ing to remove the lion in the path by lay- 

 ing down the general proposition that the 

 existence of lions is an impossibility. The 

 readiness with which the fundamental 

 hypotheses of "Relativity" were accepted 

 by many is characteristic of present-day 

 physics, or perhaps, more correctly speak- 

 ing, is an exaggerated example of it. 



Such an acceptance as this could hardly 

 be thought of as taking place half a cen- 

 tury ago when a purely dynamical basis 



was expected for the full explanation of 

 all phenomena, and when facts were only 

 held to. be completely understood if amen- 

 able to such treatment; while, if not so, 

 they were put temporarily into a kind of 

 suspense acount, waiting the time when 

 the phenomenon would succumb to treat- 

 ment based on dynamics. 



Many things, perhaps not the least 

 among them radio-activity, have conspired 

 to change all this and to produce an atti- 

 tude of mind prepared to be content with 

 a much less rigid basis than would have 

 been required by the natural philosophers 

 of a past generation. These were the 

 sturdy protestants of science, to use an 

 analogy, while we of the present day are 

 much more catholic in our scientific be- 

 liefs, and in fact it would seem that nowa- 

 days to be used to anything is synonymous 

 with understanding it. 



Leaving, however, these interesting ques- 

 tions, I will confine my remarks to a rather 

 neglected corner of physics, namely, to the 

 phenomena of absorption and adsorption 

 of solutions. The term adsorption was in- 

 troduced to distinguish between absorption 

 which takes place throughout the mass of 

 the absorbing material and those cases in 

 which it takes place only over its surface. 

 If, for instance, glass, powdered so as to 

 provide a large surface, is introduced into 

 a solution of a salt in water, we have in 

 general some of the salt leaving the body 

 of the solution and adhering in one form 

 or other to the surface of the glass. It is 

 to this the term adsorption has been applied. 

 Physicists have now begun to take up the 

 question seriously, but it was to biologists 

 and especially physiological chemists that 

 most of our knowledge of the subject in the 

 past was due, the phenomenon being par- 

 ticularly attractive to them, seeing that so 

 many of the processes they are interested 

 in take place across surfaces. 



