What is a coefficient of resistance?

[diagopod]

I'm ready Maxwell's "On Faraday's Lines of Force." I'm able to follow most of it, but he keeps using the term k without explicitly defining it, at least in a way that I can follow, and I'm puzzled by it's place in his equations, which are otherwise very simple. At one point he refers to k as "the coefficient of resistance," and unless he's leaving a term out for simplicity, it seems like one could deduce what he means by it by solving one of the equations he uses, such as

pressure = k / (4pi x r)​

but that would indicate that k = (4pi x mr) / Volume, which isn't a combination of terms that I'm familiar with or can easily picture. Anyway, anyone familiar with this term and its general meaning?

 

[Greg Bernhardt]

The coefficient of resistance is a measure of the effectiveness of a material to resist the flow of an electric current. The resistance has units of Ohms. A material with a high co-efficient of resistance has a high resistance. The co-efficient of resistance of a material is defined as the ratio of the potential difference across the material to the current flowing through the material. The resistance of a material is defined as the ratio of the potential difference across the material to the current flowing through the material.