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Information on how to take care of your microscope.
Care of the Microscope
The Microscope Stand Every microscope regularly leaves the factory in a case made especially for it in which it fits securely. If it is to be carried any distance it should be carried in the case. It should be left in the case when not in use unless some other means are provided to protect it from dust. Dust settling upon the highly polished surfaces is apt to scratch them when it is removed. It works into the bearings of the instrument, making them work hard and unnecessarily wearing them. The microscope ought not to stand continually exposed to direct sunlight. When removing the microscope from the case, or in handling it in the laboratory, do not grasp it by the arm (see frontispiece), which is actuated by the delicate fine adjustment. Grasp it by the pillar below the stage or by the stage just where the pillar joins it. The best modern instruments are provided with a new fine adjustment at the side, permitting the introduction of a handle by which the microscope can be easily handled. All rough handling is so out of harmony with the. Use of such a delicate instrument that it is unnecessary to caution against it. Finger marks on the highly polished surfaces should be removed immediately with a soft cloth or clean chamois skin. If they do not remove easily, breathe on the surfaces and rub gently. If allowed to remain for any time they are removed with great difficulty. If the surfaces become soiled with material which gentle rubbing will not remove, dampen a cloth with water and rub gently. If this will not remove it use a very little xylol, ether or chloroform, being careful not to rub too hard, and to dry as soon as possible. Never use alcohol on lacquered parts. It will dissolve the lacquer, no matter how dilute it is. When the lacquer is gone nothing can be done for it outside of the factory. All reagents should be kept from the lacquer wherever possible. On most of the better modern microscopes the more exposed parts are so finished that they are not seriously affected by any of the above mentioned reagents, with the exception of the strong acids. All such reagents should be removed as soon as possible. This finish is generally a black enamel or a gray or black plating. Sometimes this finish is extended to the upper parts of the stand. Stage. On account of its exposed position the finish of the stage is worthy of special mention. The stages of the cheaper microscopes are finished with a preparation which gives the brass a dull black appearance. They are easily cleaned as directed above. When they become gray and dingy a very little of one of the heavier oils rubbed upon them will often make them black again, unless the finish be worn off. The stages of all the better microscopes are covered with hard rubber which is not permanently effected by any of the ordinary laboratory reagents. Should the stage become soiled with balsam, immersion oil, or anything which water will not remove, it can be cleaned with xylol or chloroform. The xylol will turn the black stage to a dull gray, but a little of some heavy oil rubbed upon it will restore the original black. If the gray color is of long standing it may be necessary to leave the oil on some time. Wipe off the oil thoroughly when it has done its work. Inclination Joint. All of the better microscopes are provided with the inclination joint by which the body can be inclined to any angle between perpendicular and horizontal. Once in a while this joint wears loose so that the microscope will not remain at the desired angle. This can be tightened by tightening the nuts on the ends of the inclination axis with a heavy screw driver if the nut is slotted, or with a "spanner" if the nut it provided with two small holes. A pair of round nosed pliers will serve the purpose nicely in the absence of the spanner. With any of the tools great care should be taken not to mar the nuts. On most of the modern instruments the pin which forms the axis is slightly conical and the necessary friction is obtained by drawing the cone tighter into its bearings. This necessitates the secure the pin and put it in place. This ought to be done by the maker or an experienced mechanic. In some cases, especially in microscopes (continental type) where the prism is used in the fine adjustment the lubricant in the prism becomes gummed so that the adjustment fails to respond promptly, and then jumps. The bearings should be thoroughly cleaned and oiled with paraffin oil or watch oil. This ought to be done by the manufacturers because the mechanism is so delicate that even though safely taken apart, it would be put together and adjusted with great difficulty. Draw Tube. The draw tube should work easily and smoothly. With those which are nickeled and sliding in a cloth lined sleeve, little trouble will be found. Where they are not nickeled, care must be given them similar to that described for the sliding tube coarse adjustment. In pushing in the draw tube be careful not to push down the body tube and thereby run the front of the objective into the cover glass. Substage. The rules given above apply to the parts of the substage in general. The threads on the quick acting screw on the instruments so provided are apt to become gummed, making it hard to focus the condenser. This gum is easily "cut" with xylol or chloroform, permitting the screw to work easily. If the leaves of the iris diaphragms become rusted or gummed, clean them with xylol, and oil them thoroughly by opening and closing the diaphragm several times to evenly distribute the oil over the leaves. Should the leaves become bent or misplaced, submit them to the maker or a skilled workman. Nosepiece. When bought at the same time the nosepieces and objectives of all the best makers are now so made that the objectives are parfocal: i. e., when one lens is in focus the others on the nosepiece will be in fairly good focus when they are swung into the optical axis. They are also approximately centered so that a poinf in the center of the field of one lens will be in the field of the others. To accomplish this, each set of objectives must be especially fitted to their particular nosepiece. Care should then be taken in the laboratory not to interchange objectives. Be careful not to bend the nosepiece in any way so that the objectives will be thrown out of center. Unless you are positive that your lenses are parfocal, always focus up slightly before turning from a lower to a higher power; otherwise you are apt to swing the front of your objective against the cover glass and injure both the specimen and objective. Remember that objectives made parfocal for one tube length arc not parfocal for a different length. If occasion occurs for screwing the objectives on or off from the nosepiece, always use both hands, never letting go of the objective entirely, so as to preclude any liability of injuring them by dropping.
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Microscope Equipment 
