When sections are cut they may be transferred singly to the slide (which should be lightly smeared beforehand with a saturated solution of celloidin in oil of cloves), or they may be cut so that the back of one section of the paraffin block adheres to the front of the next, and in this way a continuous delicate ribbon of serial sections is obtained. The ribbon is broken up into lengths of about two and a half inches and transferred to the slide, on which several ribbons may be placed side by side, and so a large number of sections kept in the order in which they are cut. A mark should be made on the slide to indicate where the series begins, and each slide should be numbered, so that the exact position of each section in the series can be recognised at once. Before mounting, the paraffin must be removed from the sections. This is easily done on the slide in the case of single sections and of ribbons. If the sections are curled, a little warmth will make them unbend and lie flat. The slide is warmed over a spirit lamp until the paraffin just melts. The sections will keep their places owing to the celloidin beneath. Xylol is then allowed to flow over the slide from a pipette, until the paraffin has been completely dissolved, which can be ascertained by glancing at the sections under the low power of the microscope. The slide is placed in an almost vertical position to let the xylol drain off, excess is wiped off from the edge of the slide with blotting paper, a drop of Canada balsam solution (p. 61) is run on the slide, and a cover-glass of suitable size is applied. *Microtomes.*--After a large amount of practice, persons with a fair amount of manual dexterity may acquire sufficient skill to be able to cut very satisfactory sections of specimens embedded in paraffin, &c., by hand. In the Pathological Laboratory of a large German University, until quite recently the use of a microtome was prohibited by the Professor, who is himself a most distinguished histologist. The amount of time expended before one acquires the necessary skill, and the cheapness and great convenience of the modern microtome have combined to throw hand cutting into the background, and some form of microtome is now almost universally adopted. [Illustration: Fig. 4.--Cathcart’s Ether Spray Microtome. A, B. Wooden frame and supports. C. Glass runners. G. Screw for raising the zinc plate H. J. Ether bottle. L. Tube from air bellows.] Of these there are a very large number in the market, each having special advantages, and often special drawbacks. A few of the more generally useful only will be described. We have microtomes for cutting in gum frozen by ether spray or ice, and those intended for cutting in paraffin or celloidin.