  In the geometric theory of defects, media with a spin structure, for example,
ferromagnet, is considered as a manifold with given Riemann--Cartan geometry.
We consider the case with the Euclidean metric corresponding to the absence of
elastic deformations but with nontrivial ${\mathbb S}{\mathbb O}(3)$-connection
which produces nontrivial curvature and torsion tensors. We show that the 't
Hooft--Polyakov monopole has physical interpretation in solid state physics
describing media with continuous distribution of dislocations and
disclinations. The Chern--Simons action is used for the description of single
disclinations. Two examples of point disclinations are considered: spherically
symmetric point "hedgehog" disclination and the point disclination for which
the $n$-field has a fixed value at infinity and essential singularity at the
origin. The example of linear disclinations with the Franc vector divisible by
$2\pi$ is considered.
