October 9, 1896.] 



SCIENCE. 



519 



the systematic and careful amassing of ex- 

 perimental data for building up or verifying 

 these theories, was done by a few European 

 workers, mostly chemists ; since Willard 

 Gibbs's theoretical work bearing upon this 

 subject, scarcely a single addition of impor- 

 tance has come from American workers ; in 

 fact, it seems that much of the work done 

 abroad is scarcely known to American 

 physicists. It is to be regretted that in the 

 history of the development of this branch 

 of electrical science hardly an Aruerican 

 name will appear. 



There, however, remains much to be 

 done, and contributions from this side will 

 I trust be made. 



Whether electrolytic action ever occurs 

 in solids, is a question which I do not be- 

 lieve has been definitely settled. If such 

 action ever does take place, the theories just 

 considered will have to be modified. Some 

 very curious phenomena in glass, subjected 

 to the action of the electric currents, have 

 been noticed; the claim has been made that 

 glass has actually been electrolyzed, though 

 the evidence so far is not conclusive. The 

 very interesting changes of conductivity 

 with variation in temperature, exhaustively 

 studied by Thomas G-ray, indicate molecu- 

 lar changes which may be due to dissocia- 

 tion. The form of the equation for change 

 in conductivity with temperature shows a 

 maximum with reversal, considerably be- 

 low the fusing point. A similar peculiarity 

 is noticed in alloys. The systematic study 

 of this seems important. 



Careful study of heat absorption when 

 salts are dissolved should be made. Much 

 work has been done in this direction. A 

 careful examination and comparison of re- 

 sults, however, convinces one that the 

 methods and manner of conducting the in- 

 vestigation must have been widely different, 

 for the results vary in a most astonishing 

 manner; at any rate, definite conclusions 

 cannot be based upon them. If ionization 



requires energy, it is more than likely that 

 some will be taken from the solution in the 

 form of heat. In very dilute solutions 

 dissociation of the electrolyte seems com- 

 plete, while in concentrated solutions it is 

 incomplete. A careful determination of 

 the heat absorption per molecule, when the 

 salt is dissolved in concentrated or dilute 

 solutions, might give valuable results. The 

 problem is very complicated, yet it should 

 be attacked. 



That gases can conduct electrolytically 

 seems fairly certain. This field is scarcely 

 entered and may well be studied. 



The peculiar behavior of charged plates 

 under the influence of violet light seems 

 likely to involve electrolytic action and 

 bear upon dissociation questions. 



So multitudes of problems suggest them- 

 selves, the study of which may tend to crys- 

 tallize the theories of dissociation and solu- 

 tion, so promising at this time, into more 

 perfect form. It can scarcely be doubted that 

 the remarkable connection, evident when 

 the phenomena of solution, modification of 

 freezing and boiling point, osmotic pressure, 

 optical rotation, chemical equilibrium and 

 stability, metathetical reaction, thermal 

 neutrality, electrical conductivity and elec- 

 trolysis are considered, taking the molecu- 

 lar equivalent mass as the unit, indicates a 

 very near relationship of these processes. 

 The power of Arrhenius ' s dissociati on theory, 

 Van't Hoft's solution theory, together with 

 the conceptions of Hittorf, Clausius, ISTernst 

 and Ostwald in explaining the dynamics 

 of molecular action, is most promising. 

 Whether more accurate and more plentiful 

 quantitative studies of these so closely re- 

 lated phenomena will lead to closer con- 

 cordance or greater divergence of the nu- 

 merical values obtained, and thus strengthen 

 or reveal weaknesses in the theories, must 

 remain to be seen. 



These theories, if fastened, will have a 

 marked influence both upon the chemical 



