| 摘要 |
A magnet for catching thereon by magnetic attraction metallic foreign bodies within the reticulum of a ruminant is manufactured by preparing an instrument which comprises metallic members (2) having higher magnetic permeability than that of a material (1) to be magnetized, fitting the instrument snugly on the material, putting the material within a yoke (6) for magnetization, and applying direct current to an excitation coil (5) within the yoke. The magnet thus obtained has a plurality of magnetic poles in an optional position thereof except the opposite ends to effectively catch the metallic foreign bodies within the reticulum of the ruminant. |
