306 
PROFESSOR J. H. POYNTING ON ELECTRIC CURRENT, ETC. 
r , da _ d^a 0 
4 ^ c ,^+K^ = -v-«- 
d /da d/3 dy 
clx \dx ' dy ' dz 
with corresponding equations for /3 and y. 
Differentiating the second of these with respect to z, and the third with respect to 
y, and subtracting, we obtain 
dhb _ 
dt?~ 
— V 2 w 
with corresponding equations for v and w. 
These correspond to Maxwell’s equations (7), p. 395. 
In conclusion it may be remarked that the equations found in this paper give the 
same expression for the rate of Transfer of Energy as that in my previous paper 
derived from Maxwell’s equations involving F, G, and H. 
