Bresser Junior 8851300GSF000 Mode D'emploi page 13

When you do so, note that the sharpness of the picture must be adjusted
again for the higher magnification. Also, the higher the magnification, the
more light you will need for good illumination of the picture. The wheel
with pinhole apertures (13) below the microscope stage (4) will help you
in viewing very bright or clear-sighted preparations. Turn the wheel (13)
till the best contrast is achieved.
4. Observation (electronic light source)
For observation with the electronic light source (6) you need to insert 3
AA batteries 1.5 V, in the battery compartment (8) on the base of the mi-
croscope (7). The battery compartment is opened using a Phillips screw-
driver. Insert the batteries with the correct polarity (+/- indication). Put
the battery cover first into the small opening so that the lid fits perfectly.
Now you can tighten the screw.
The lighting is switched on when you turn the switch on the microscope
base.
Now you can observe in the same way as described in the previous section.
TIP: The higher the magnification you use the more light is required for a
good illumination of the picture. Therefore, always start your experiments
with a low magnification.
5. Condition and prepare viewed objects
5.1. Condition
This microscope features transmitted light, so that transparent speci-
mens can be examined.
If opaque specimens are being examined, the light from below goes
through the specimen, lens and eyepiece to the eye and is magnified en
route (direct light principle).
Some small water organisms, plant parts and animal components are
transparent by nature, but many others require pretreatment — that is,
you need to make a thinnest possible slice of the object by hand cutting
or using a microtome, and then examine this sample.
5.2. Creation of thin preparation cuts
Specimens should be sliced as thin as possible. A little wax or paraffin is
needed to achieve the best results. Put the wax into a heat-safe bowl and
heat it over a flame until the wax is melted. You can use a candle flame
to melt the wax.
DANGER!
Be exremely carfeful when dealing with hot wax, as there is
a danger of being burned.
Then, dip the specimen several times in the liquid wax. Allow the wax that
encases the specimen to harden. Use a MicroCut or other small knife or
scalpel to make very thin slices of the object in its wax casing.
EN
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