We have thus endeavored to give, in as simple a manner as possible, such information as will guide the microscopist to the acquisition of skill in this most important but generally despised department of his art. We are told by the biographer of Swammerdam that a great deal of his success was to be attributed to his skill in sharpening his fine knives and scissors. The same is also stated of other noted workers, and yet none give even the slightest directions to the novice who desires to follow in their footsteps. There is not to our knowledge a single book in the English language which treats fully of this subject, with perhaps the exception of Holtzapffel’s work on “Mechanical Manipulation,” and this has long been out of print. As previously stated, however, it is only by practice that the necessary finger-skill can be acquired, but this skill is well worth acquiring at any cost. The man who depends upon cutlers and knife grinders will never make satisfactory progress. NOTE H. We are inclined to believe that the difficulty of enclosing glycerine does not arise from the dissolving action of this liquid, so much as from the great adhesiveness which exists between it and glass. Oily cements are of course attacked by glycerine, but shellac and several other gums are insoluble, and drying oils, if well oxidized are also insoluble. Where cells are used they must be first firmly attached to the clean slide, and the cement should also be brought into direct contact with the clean cover. Glycerine does not evaporate at ordinary temperatures, and consequently wherever the slide or cover is soiled with it, no cement will ever adhere until the glycerine has been wiped off. There is no prospect of its drying. NOTE I. Page 48. The solution here referred to, and which is known as Kleinenberg’s solution, is made in the following way: (1.) Make a saturated solution of crystallized calcium chloride in 70 per cent. alcohol, and add alum to saturation. (2.) Make also a saturated solution of alum in 70 per cent. alcohol. Add (1) to (2) in the proportion of 1:8. To the mixture add a few drops of a saturated solution of hæmatoxylin in absolute alcohol. This solution may be used in very many cases for staining sections, in place of the ordinary watery solution of logwood alum. It may, if required, be diluted with the mixture of 1 and 2. The stained sections are placed at once in strong spirit. ------------------------------------------------------------------------ INDEX. Acetic acid, 38 Adipose tissue, 63 Æther microtome, 24 Air-bubbles, 40, 55, 62 Alcohol, 17, 19 absolute, 54 Balsam, Canada, 46, 51 to clean from slide, 55 Beale’s carmine fluid, 33 Bell’s cement, 41 Blue staining fluid, 60 Bone, 16, 57 decalcified, 58 Bottles for media, &c., 48 Brain, 59 Brunswick black, 41