where the constant c means the ratio between the electro-magnet and the electrostatic unit of electricity.

From these equations we can deduce:

(α) For the interior of a body, the equations

Hz Hy= 1Cx,  Hx Hz= 1Cy,  Hy Hx= 1Cz
∂y ∂zc∂z∂xc∂x∂yc

(12)

Ez Ey= − 1 Bz,  Ex Ez= − 1 By,  Ey Ex= − 1 Bz;
∂y∂zc∂t∂z∂xc∂t∂x∂yc∂t

(13)

(ß) For a surface of separation, the continuity of the tangential components of E and H;

(γ) The solenoidal distribution of C and B, and in a dielectric that of D. A solenoidal distribution of a vector is one corresponding to that of the velocity in an incompressible fluid. It involves the continuity, at a surface, of the normal component of the vector.

(b) The relation between the electric force and the dielectric displacement is expressed by