Avoid all violent contact of the objective lens and the cover glass.
(10) Keep eyepieces in the microscope at all tines to keep free of dust.
(11) To remove dust, brush the lenses with a camel's hairbrush. Avoid hard
wiping, as dust is often hard and abrasive.
(12) Xylene is the only agent that should be used in cleaning lenses or
removing oil from objectives. Only small amounts of xylene are necessary and should
be used with care.
(13) When sewing machine oil is used to lubricate moving parts of the
microscope, all excess should be wiped off to prevent the collection of grit and dust.
(14) The microscope should be protected against direct sunlight and
(15) In very warm, humid climates, microscopes should be stored in dry
cabinets when not in use. Such cabinets should be reasonably airtight, equipped with a
light bulb to supply heat, and several cloth bags containing a hygroscopic salt, such as
calcium chloride, to absorb moisture. In warm, humid climates, the lenses of
unprotected microscopes can be attacked by certain fungi that etch glass and ruin the
(16) After use, always turn the nosepiece to a position, which brings the low
power objective into direct line with the opening in the substage condenser. If this
precaution is not taken, the longer, higher-powered objectives can accidentally come
(17) The entire microscope should be cleaned frequently to remove dust,
finger marks, oil, grease, and remnants of specimens. All parts of the microscope
should be kept scrupulously clean at all times.
(18) Never tamper with any of the parts of the microscope. If the instrument
does not seem to be functioning properly, immediately call the matter to the attention of
the laboratory supervisor.
(19) Maintenance of the microscope should be done in accordance with the
manufacturer's booklet of instruction.
(20) Immediately after use, the oil immersion objective must be wiped clean
of oil with a soft, absorbent lens paper.
(1) Binocular. This type of microscope is preferred since it gives a more
natural and restful condition of observation. A beam-dividing prism and three mirrors