What is the meaning of nonpermeable in Jackson's Section 5.10?

[Old Guy]

Homework Statement

I'm reading Jackson Section 5.10, where he solves for a uniformly magnetized sphere "embedded in a nonpermeable medium." I'm not looking for an example, but to understand what it means. It can't mean there is no B or H field external to the sphere; in fact, Jackson has a figure showing field lines. Does it perhaps mean that there is no source of B or H external to the sphere? But if that's the case, wouldn't the exterior region be free space which has a permeability?

Homework Equations

The Attempt at a Solution

 

[gabbagabbahey]

The definition of magnetically non-permeable is that the material has the same magnetic permeability of free space \mu=\mu_0, and hence will have zero magnetization.

 

[Old Guy]

Thanks, I can accept that. Just seems like an odd choice of words (or maybe my many years working with fluid flow in porous media . . .)