1. For working, select a northern window; this insures the greatest amount of reflected light possible from white clouds. Never use direct sunlight, and if possible avoid artificial light. If southern exposure alone is available, have window-blind, and that well drawn.

2. The instrument should be placed between the operator and the window, and, all working parts being in order, the mirror and lens to be used should be wiped with soft chamois leather.

3. The body of the microscope should be about vertical, so as not to interfere with mounting in fluid media; the mirror should be adjusted to reflect light through the instrument, using plane side for parallel rays and concave side for divergent rays.

4. Having inserted objectives into the nose-piece, place object for examination in the centre of the slide under the cover-glass, and this as near the middle of the stage as possible; adjust light by mirror and diaphragm, and focus with coarse adjustment.

5. Make all first examinations with low power and large diaphragm aperture, at least the one yielding distinct vision; then follow with higher powers and smaller apertures. The power should always be increased at the objective first, observing the following combination:

6. Hold and adjust slides with thumb and forefinger of left hand; manipulate coarse and fine adjustments with right hand.

7. To focus, turn the objective down toward slide by means of coarse adjustment, short of contact; then with eye over the ocular focus backward until object is in view; from this point the exact focus can be made by one turn of the fine adjustment. With high powers focus in the same way, never allowing lower end lens of objective to come in contact with cover-glass or any liquid, as such carelessness usually results in injury to object and objective. When properly focused, work fine adjustment slightly forward and backward during observations, to get a series of optical sections of the object; also move slide on stage to bring in view different parts.

8. Never lift slides from stage, but gently slide them off without upward movement. Previous to doing this the tube should be raised out of focus, especially with high powers.

9. Accustom yourself to use both eyes indifferently, and when one is in use keep the other open - never closed; this can soon be acquired with a Tittle practice.

10. In examining powdered specimens, a very small amount is placed upon a slide centrally, a drop of water or glycerin added with a pipette; now put over this with forceps (slantingly to avoid air-bobbles) a cover-glass, using slight pressure on it after it is in proper position, and absorb superfluous fluid with camel's-hair pencil or blotting-paper.

11. If specimen be tissues of which cross-sections are to be taken, use for this purpose a razor or microtome (the latter only in experienced hands). The razor should have lower surface flat, upper slightly hollow-ground; should be sharp, opened in straight line with handle, and sections made by pulling from heel to toe, using in the sliding cut considerable edge length. Both razor and object should be wet while cutting, to prevent adhesion and admission of air; if material is fresh, use for it water or diluted alcohol; if material has been hardened, employ same strength alcohol as used in the hardening process.

12. Hold objects between the forefinger and thumb, allowing the razor to rest upon the former, when the sliding cut can be made. Sections should be cut as thin as possible so as to include but one layer of cells, which proficiency can be acquired only after considerable practice. Remove sections with a camel's-hair pencil to a watch-glass containing water, and as desired arrange a section on the slide under the cover-glass with a drop of water, when it is ready for examination and the introduction of various reagents. If object be too small for such handling, it should be imbedded in some relatively hard substance - dried elder pith, cork, paraffin, etc., and then cross-sections taken as before, but through the combined mass.