218 Dr. Meyer Wilder man : Connexion between the 



wave-length of the aether- vibrations. All these detailed 

 conclusions, which here follow as a necessity from purely 

 thermodynamic considerations, find their experimental veri- 

 fication in the above-mentioned research, published in the 

 Philosophical Transactions of the Royal Society, Oct. 1902, 

 and will be further given in the author's research with 

 metallic plates, which will be communicated in due course. 



Since the introduction of light into the system with 

 independent variables of composition changes in any case 

 their chemical potentials, and with it their chemical energy, 

 it is evident that all those physical and chemical phenomena 

 which in one way or another are dependent upon the chemical 

 potentials of the components of a system, such as the electro- 

 motive force, the surface-tension, &c, will also undergo a 

 variation when the system is exposed to light. As all these 

 phenomena are either changed or created by the variation of 

 the chemical potentials of the components, they w T ill change 

 under the influence of light in the same manner as the 

 chemical potentials do, i. e., they will all have under the 

 action of light their induction and deduction periods, with all 

 the properties of the same which were mentioned above, and 

 after the induction period has passed they will all reach 

 a constant value corresponding to the maximum variation of 

 the kinetic energy absorbed by the system under the action 

 of light. 



C Chemical Statics and Dynamics under the 

 Influence of Light*. 

 It remains to he seen what are the results obtained for 

 equilibrium and for velocity of reaction when each of the 

 components of the system has not only a (new) chemical 

 potential, but also a light-kinetic potential. 

 If we integrate the equation 

 dE + dEi = dE' = t'drf -j'dv' + /ijdmj + XjdmJ. . .fijdmj + Udm n , (i.) 

 under the supposition that the quantity of the mass of the 

 given layer or system (under conditions mentioned on p. 209) 

 with independent variables of composition increases from zero 

 to a finite value, while the nature and state of the system 

 remain the same, we get 



E + E^=E' = t' V ' -p'v + (fr +\ i ym\.. + (fin +*n)mn\ (ii.) 



Differentiating the same in the most general way : 



dE' = t'drf' + v'dt ' —p'dc - v'dp + (^ + V) dm l ' 



-V m 1 , d(jx i + V). . . + (p,; + \ n ')dm n ' + m n 'd(p n ' + \ n '), 



* See author's paper under the same heading- in the Phil. Trans, of 

 the Royal Society, October 1902, pp. -376-80.5. 



