Page 23 - General and Inorganic Chemistry for Advanced Secondary Schools Students Book Form Five and Six

Biology for Secondary Schools

For example, if the eyepiece (e) When the microscope is not in use
magnification is 5× and the for a long time, remove the lenses
objective lens magnification is and put them in a desiccator.
40×, then the total magnification is (f) Do not touch the microscope with
5 × 40 = 200× wet hands.
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(h) Rotate the nosepiece to a higher (g) Do not touch the surface of the
power objective lens, if you want mirror or the lenses with your
to observe more details of the fingers.
specimen. Figure 2.13 shows a (h) Lubricate the moving parts
student using the light microscope. regularly.
(i) Always use the coverslip in
order to protect the lenses of the
microscope from getting into
contact with the specimen.
(j) Remove the slides from the stage
immediately after use.
(k) Move the objective lenses up when
storing the microscope.
(l) When storing the microscope,
rotate the rotating nosepiece so
Figure 2.13: Student using the light that the low magnification lens is
microscope in line with the eyepiece lens.

How to care for the light microscope
Turn the adjustment knob slowly. Activity 2.1: Using the light microscope
Always start with the coarse adjustment
knob. Materials: Light microscope, microscope
(a) Lift the microscope using both slide and coverslip, razor blade, knife or
hands, one hand holding the arm scalpel, onion bulb, forceps, mounting
and the other holding the base. needle or glass rod, iodine solution,
(b) When not in use, cover the and blotting paper
microscope with clean cloth and
store it in a dry, dust-free place. Procedure
(c) Clean dirty lenses using lens tissue 1. Use the knife to cut the onion
or a soft cloth. bulb vertically or lengthwise into
(d) Do not place the microscope at four pieces.
the edge of the table or bench as it
could be knocked over.

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