When we have cut an exceptionally good section or when we have some specially interesting object we may wish to make a permanent slide. The exact method of doing so varies somewhat with the nature of our object and to describe all the methods of mounting microscopic objects permanently would require a book in itself. We will suppose that we wish to make a permanent slide of one of the sections floating in our watch glass of water. The first thing we must do is to get rid of the water with which our section by now is saturated. This may be accomplished by means of alcohol of various strengths, which we may put into three watch glasses. In the first watch glass we have half pure alcohol and half water; in the second three-quarters alcohol and one part water; in the third watch glass pure or absolute alcohol. The section is transferred on a brush to the first watch glass and left there for five minutes, then to the second watch glass for a similar time and finally to the third watch glass. The mountant may be either Canada Balsam or glycerine jelly. Should we decide on Canada Balsam, we put a small drop of the substance in the centre of a clean slide, place one section atop of it and then gently lower a cover slip upon it as already described. Then, without using any force, the cover slip is pressed down, but we must not fall into the all too common error of thinking that a thick section can be made thin by pressing upon the cover slip. If we have taken the correct amount of Canada Balsam it will just cover the area below the cover slip and no more, if we have used too much, it will flow out on all sides and perhaps on the top of the cover slip. A very little experience will teach how big a drop of Balsam to use. Should we decide to use glycerine jelly, we take a small globule of the jelly on one of our mounted needles and place it in the centre of a clean slide. Then we hold the slide a little above a lighted candle, or even a match will do, to melt the jelly. Directly it is melted the section is placed upon it, and we proceed as before. Whichever mountant we have used, the slides must be put away out of the dust, and they must be flat and not placed on edge. In a few days the mountant will set, and we need take no further precautions with the slides in which Balsam was used, but those mounted in glycerine jelly must be ringed, for the reason that glycerine absorbs moisture from the air and gradually liquifies.