A simplified presentation of the relation between motion (space transformation) of a set of objects with spin and the induced (nonrelativistic) spinor transformation by development of quaternions from certain four-dimensional rotation matrices. These are interpreted as conformal transformations in three-space. Quaternions are essentially equivalent to Pauli spin matrices which can be generated by regarding a quaternion matrix as compound—i.e., a 2×2 matrix with 2×2 matrix elements. Explicit formulas with instructions for their use are given.