rho

We might, therefore, take ρ as a unit of time, unless we prefer to consider this value as an imperishable standard of time.

We must, in particular, remember what is meant by the specific resistance, ρ of mercury in the electrostatic system.

In fact, ρ is not simply a quantity the measure of which is found to be in relation with the measure of time.

The heat produced will be proportional to S, to the density ρ, and to the cube of the velocity v.

Both ρ and χ are functions of z, the value of which remains the same when z − c is substituted for z.