Microtome

Microtome, an instrument for cutting thin sections of portions of plants and animals preliminary to their microscopic examination. The objects to be cut are imbedded in some material such as paraffin or celloidin, or frozen in gum, which makes the slicing of minute or delicate objects readily feasible. The cutting used to be done by holding the prepared object in one hand and wielding a razor in the other, but this method, apt to yield sections of unequal or insufficient thinness, has given place to the use of some form of microtome, which is at once quicker and more effective. These instruments are quite simple devices by which a sliding razor slices a fixed but adjustable object, or by which the object is made to move up and down across the edge of a razor. As typical forms may be noted the freezing microtomes of Rutherford and others; the sliding microtomes common on the Continent; the ingenious 'Rocker' of the Cambridge Instrument Company—a favourite instrument in British laboratories; and more elaborate and automatic machines manufactured by the same company.