820 THE POPULAR SCIENCE MONTHLY. 



heat, moreover, do not permit us to see in onr present simple bodies 

 polymers of the same substance comparable to known polymers. 

 The specific heat of the last increases, according to Woestyn's law, 

 with the complex structure of their molecule, while the specific 

 heat of simple bodies varies, according to Dulong and Petit's law, 

 inversely as their equivalents. 



We may, nevertheless, conceive the unity of matter in another 

 sense. Some chemists oppose to Prout's hypothesis a new and 

 more comprehensive one, which consists in regarding the elements 

 as states of stable equilibrium in which matter exhibits itself. 

 " In this order of thought," says M. Berthelot, " a body reputed 

 simple could be destroyed but not decomposed in the ordinary 

 sense. At the moment of destruction it would at once transform 

 itself into one or several other simple bodies, identical with or 

 resembling the existing elements. But the atomic weights of the 

 new elements could not offer any commensurable relation with 

 the atomic weight of the primary body from which they are pro- 

 duced by metamorphosis. More than this: by working under 

 different conditions we might see appear sometimes one system, 

 sometimes another, of simple bodies, developed by the transforma- 

 tion of another element. Only the absolute weight would remain 

 invariable in the course of the transmutations." 



Even under this hypothesis the hope of forming simple bodies 

 need not seem chimerical. Unfortunately, we have no more rea- 

 sons for encouraging it than for condemning it. All that can be 

 said respecting it is that the present condition of science does not 

 allow us to discern any method that will lead to the end. Would 

 it not be wiser, then, to make our theories more complete rather 

 than venture into this darkness without a guiding thread ? It is 

 no mystery to any one that they greatly need improvement. The 

 imponderable fluids have only just passed away ; the ether, too, 

 seems to be already withdrawing, taking along with it, perhaps, 

 the atom of the chemists ; and does it not seem that everything is 

 about to be explained by motion ? 



M. Berthelot discusses these questions with his well-known 

 vigor and originality. His work, erudite and pointed, is par- 

 ticularly instructive to the thinker. He in fact restores to our 

 view the affiliation of the systems that were conceived at the 

 birth of chemistry, and which have been revived at our time in 

 the effort to resolve the eternal problem of the constitution of 

 matter. — Translated for The Popular Science Monthly from the 

 Bevue Scientifique. 



