56 Dr. Meyer Wilder man on the Velocity of 



be further shown that dp=—gydh, if 7 is the density, i.e., 

 that the pressure is a function of the height alone. 



Equations (7) give the condition of chemical equilibrium 

 and with it of all other forms of energy connected with matter ; 

 for this it is necessary and sufficient that 



fii + gh + X 1 -f- vi — const. 

 /jl 2 + gh + X 2 + v 2 = const. 



Hn+gh + \ n + v n = const (5) 



i. e., the sum of all the potentials of one and the same inde- 

 pendent variable must be through the ivhole system constant. 

 As can be perceived, this is not restricted to the further 

 condition that each potential taken separately should be through 

 the whole system constant, which ivould mean nothing else than 

 again the conclusion drawn jrom the second law of thermo- 

 dynamics in reference to the potentials when taken separately. 

 Because the potential of gravity gh cannot possibly be every- 

 where the same, changing with the height or distance from 

 the hoj^izontal plane, and so also the kinetic energy created 

 by light or electric waves in the system, depending as it 

 obviously does upon the intensity of light and its composition, 

 cannot be in the different layers of the system the same, the 

 light being changed in its intensity and composition on 

 passing through the different layers. It is further evident 

 from (D) that whenever the independent component will 

 contain the potential gh or X, or both, //, and v must also 

 change at the same time. Thus we arrive at the following 

 very remarkable and most general results : — 



1. If one and the same component is affected by two or 

 more potentials at the same time, the condition of equilibrium 

 is that the sum of all the potentials of the same component 

 shoidd be the same through the whole mass, while each of the 

 potentials separately may change in a different direction or 

 directions. 



2. If one and the same component is affected by two or 

 more potentials, unless they can by themselves be separately 

 constant through the whole system (/jl, v), the values of each of 

 the potentials, including (/a, v), is no constant quantity, but a 

 changeable quantity, conditioned in its value by the presence 

 and value of the other potentials. 



3. From this the quantitative connexion between the different 

 potentials and the different kinds of energy connected with one 

 and the same component of the system, (e. g. m^ follows : 



The difference between the values of one or more of the 



