| 摘要 |
<p>Method in a microtome, especially an ultramicrotome, in which a knife edge, turnable around its longitudinal axis, is used to cut sections from a specimen by making the specimen downwardly pass over the knife edge. The distance between the knife edge and the specimen before cutting is made extremely narrow without the specimen touching the knife. The slit is lit up from below by a light waveguide, one end of which is located under the knife edge and is turned with this and the other end of which is lit up by a light source movable in relation to the turning of the knife edge. The light from the waveguide is reflected against the surfaces of the knife as well as of the specimen which are turned towards the slit. The image of the knife surface reflected in the specimen surface, the size of which is proportional to the breadth of the slit, is viewed from at least one point located in a vertical plane outside of the vertical plane of the slit and on the same side of this as the knife.</p> |
