=Paraffin-ovens= and =drying-ovens= of suitable size, and constructed preferably of copper, are necessary for paraffin work. The water-space about the oven should be sufficiently large, and the temperature should be controlled by a thermo-regulator. Various models are offered in the trade, but they can be made more cheaply by the local tinsmith. The thermo-regulator can also be home-made by anyone who has the necessary training in glass-blowing usually given in courses in bacteriology. =Various instruments= and =utensils=, such as _razors_, _double-bladed knives_, _forceps_, _spatulas_, _section-lifters_, _needles_, _scalpels_, _scissors_, _glass rods_ and _tubing_, _test-tubes_, _graduates_, _flasks_, _funnels_, _bottles_, _staining dishes_, _reagent bottles_, _rubber tubing_, _water-bath_, _tripods_, _centrifuge_, _Bunsen burners_, _asbestos pads_, _gauze_, _filter-papers_, _absorbent paper_, _labels_, _oil_ and _wax colored pencils_, _slides_, _cover-glasses_, _slide-boxes_, _camel’s-hair brushes_, _glass droppers_, _platinum wire_, etc., are required for the pathologic laboratory, and can be chosen to suit the individual needs. The solid watch glasses make very good small staining dishes; the enamelled trays and glass dishes used in photographic work are especially adapted to the plate-method, particularly the size used for the 4 × 5 plate. Tea-strainers or small sieves can be used for staining a large number of celloidin sections; and there are different types of staining-dishes designed for the staining of slide- and cover-glass preparations in number. Slides should be of the best quality, colorless and with ground edges, and of medium thickness. Cover-glasses should be square or oblong, round covers having but little use in pathology. For ordinary work the No. 2 square, ¾ inch, is recommended; for work with the higher-power dry objectives a thinner cover must be used. Slides and covers may be cleaned by placing them in a solution of equal parts of one per cent sulphuric and chromic acids and then rinsing in distilled water. A good cleaning fluid is also made of one part acetic acid to three of 80 per cent alcohol. To clean old mounts melt the balsam by heat or dissolve in turpentine, separate slides and covers, boil in ten per cent lysol for half an hour, or for ten minutes in the sulphuric-chromic-acid mixture, rinse thoroughly, dry with cloth having no lint. The laboratory should be supplied with running water, a sink large enough for washing out specimens, numerous stop-cocks, and a drip-board. Distilled water in abundance must be available. The laboratory-table should have an alcohol- and xylol-proof finish, black on the whole being the most practical color. A portion of the table should be covered with glass beneath which there is laid a sheet of white paper. CHAPTER XVIII. THE EXAMINATION OF FRESH MATERIAL. I. METHODS OF EXAMINATION.