LVI ROYAL SOCIETY OF CANADA 



" ment. Matter cannot so far as we know be transmuted from one 

 '• kind to another, though in some cases it assumes what is called au 

 " allotropie form. The great characteristic of energy, on the other 

 •^'hand, is that, in general, we can readily transform it, (in fact it is 

 ''of use solely because it can be transformed), but in all its transfor- 

 '' mations the quantity remams precisely the same.'' 



It will be observed that Tait is very cautious in Ms wording, " So 

 far as we yet know," he says. His caution is justified. For here a 

 distinct advance has been made in proving the transformation of some 

 lands of matter, and a vast field of inquiry has been opened. 



Dissipation of Matter. 



The inquiry itself suggests another companion principle whose cor- 

 relation may be indicated by the terra Dissipation of i\iiatter (a term I 

 have not yet come across), corresponding to what Lord Kelvin called the 

 '^ Dissipation of Energy." This latter prjnciple points out that "every 

 " time a transformation takes place, there is always a tendency to pass, at 

 "least in part, from a higher or more easily transformable to a lower 

 •'■' or less easily transformable form. 



" Thus the energy of tlie universe, is on tlie whole, constantly 

 "passing from higher to lower forms." The low form to which it 

 seems to tend being " that of uniformly dilfused heat." 



A quotation farther on, will again offer us a comparison of " then " 

 and '■' now." "' Thus," lie says, '" so far as we can yet determine in 

 " the far distant future of the universe, the quantities of matter and 

 '' energy Avill remain absolutely as they now are." ('■Then" and "Now" 

 agree in this ; they differ in the next clause, viz. ) — "' the matter un- 

 changed alike in quantity and quality; — the energy also unchanged in 

 quantity^ but entirely transformed in quality to the low form of uni- 

 formly diffused heat." 



Now the recent discoveries show that the transformations of matter 

 which lare going on in nature, are so far as observed, from " higher to 

 lower forms " to use Tait's terms. 



If then the principle, should, by a process of exhaustion, be proved 

 to be general and tlie lowest fonn be ascertained, we shall have the 

 companion principle and shall be able to say that in the far distant future 

 of the universe not only will all energy be reduced to uniformly diffused 

 heat but al] matter to its lowest form. 



This further permits the possibility of the supposition that some of 

 the nebulae visible to us, instead of being the beginnings of new suns or 

 planets, may, in fact, be the wreckage of worlds or world-systems like 

 our own floating m the illimitable ocean of space. 



