RICHARDS. — SOURCE OF CHEMICAL HEAT. 409 



larked ; one, the continuity of the liquid and gaseous state, and the other, 

 the porosity of solids. 



In answer to the first, attention may be called to the fact that the con- 

 tinuity of the liquid and gaseous condition exists actually only at the 

 critical pressure ; below that point they are, as a matter of fact, discon- 

 tinuous and very different. Perhaps the critical pressure is simply the 

 point where the gas molecules at the critical temperature are pressed 

 into actual contact. The compressibilities of very compressed gases are, 

 in fact, of the same order of magnitude as those of liquids. 



Porosity is usually only manifest under very great pressure, which 

 might be enough to compress the atoms into smaller space, and thus 

 open orifices which previously did not exist. 



From these considerations it seems to me that the new kinetic concep- 

 tion of the solid and liquid state has no disadvantages which the old 

 conception does not possess, while it has many advantages which the old 

 theory has not. 



But it is not the intention of the present paper to enter into the detail 

 of so large a question. I hope that in the next few years I may be 

 permitted to study and report upon the possible consequences of the 

 significance of changing atomic volume. 



In the preceding paper and the present one, the following phenomena 

 have been suggested as capable of a new and plausible interpretation if 

 atoms are considered as capable of altering their volume through a wide 

 range ; namely, the heat of chemical reaction, adsorption, adhesion, 

 and cohesion ; ordinary solution ; electrolytic solution ; electrolytic dis- 

 sociation ; the passage of electricity through solids, liquids and gases ; 

 the nature of cathode rays (and probably also X rays and radium) ; the 

 laws of Faraday and Dulong and Petit ; false and true equilibrium ; 

 heat capacity and thermal expansion ; quantivalence ; stereo-chemistry 

 and crystal form ; and the critical phenomena. 



Following papers will be devoted to a development, quantitative 

 where possible, of these applications, as well as of many others. Unless 

 further study reveals discrepancies, which have hitherto been concealed, 

 I expect to be able to show : — 



1. That the conception is not inconsistent with the two laws of energy. 



2. That it conflicts with none of the quantitative conclusions of the 

 atomic hypothesis, nor with the kinetic theory of gases, if heat be assumed 

 to be due to mechanical energy operating upon atomic inertia. 



3. That it is able to interpret the actual deviations of gases from the 

 gas law better than any other theory, retaining the essential import of 



