Accessories - Bresser BIOLUX NV Mode D'emploi

appear sharply.
7.2. Textile fibres
Objects and accessories:
1. Threads of different textiles: Cotton, line,
wool, silk, Celanese, nylon etc..
2. Two needles
Each thread is put on a glass slide and
frayed with the help of the two needles. The
threads are dampened and covered with
a cover glass. The microscope is adjusted
to a low magnification. Cotton staples are
of vegetable origin and look under the
microscope like a flat, turned volume. The
fibres are thicker and rounder at the edges
than in the centre. Cotton staples consist
primary of long, collapsed tubes. Linen fibres
are also vegetable origin; they are round and
run in straight lines direction. The fibres shine
like silk and exhibit countless swellings at the
fibre pipe. Silk is animal origin and consists
of solid fibres of smaller diameter contrary
to the hollow vegetable fibres. Each fibre
is smooth and even moderate and has the
appearance of a small glass rod. Wool fibres
are also animal origin; the surface consists of
overlapping cases, which appear broken and
wavy. If it is possible, compare wool fibres of
different weaving mills. Consider thereby the
different appearance of the fibres. Experts
can determine from it the country of origin
of wool. Celanese is like the name says,
20
artificially manufactured by a long chemical
process. All fibres show hard, dark lines on
the smooth, shining surface. The fibres ripple
themselves/crinkle after drying in the same
condition. Observe the thing in common and
differences.
7.3. Salt water prawns

Accessories:

1. Prawn eggs (Fig 2, 25d)
2. Sea salt (Fig 2, 25c)
3. Prawn breeding plant (Fig 2, 23)
4. Yeast (Fig 2, 25a)
CAREFUL!
Eggs and prawns are not fit
for human consumption.
7.3.1 The lifecycle of the saltwater prawn
The saltwater prawn or artimia salina to
scientists has an unusual and interesting
lifecycle. The female's eggs are hatched
without any male shrimp having to fertilise
them. The resultant baby prawns are all
female. Under unusual circumstances such
as when a swamp is drained the eggs may
produce male prawns. These males fertilise
the female's eggs, resulting in a specific
type of eggs. These are called winter eggs
and have a thick shell as protection. They're
pretty rugged and can survive the swamp or
lake drying out causing the death of the entire
prawn population for up to a decade in a form
of hibernation. The eggs hatch once again as
soon as the correct ambient conditions have
been obtained. The eggs supplied (Fig 2,
25d) are of this type.
7.3.2. Hatching of the salt water prawn
To hatch the prawn it is essential to first have
a saline solution suited to the prawn's needs.
Fill half a litre of rain- or fresh-water in a
container. Let it stand for about thirty hours.
As water evaporates over time it's a good idea
to have a second container of such water
left standing for thirty-six hours. Once stood
for this length of time pour half of the sea
salt supplied into one of the containers (Fig
2, 25c) and stir until it has dissolved. Then
pour some of it into the prawn breeding plant
(Fig 2, 23). Add a few eggs and close the lid.
Put it somewhere with plenty of light but not
in the direct sun. The temperature should be
approximately 25° C. The prawns will hatch in
two or three days at this temperature. Should
any water evaporate during this time replace it
from the second container.
7.3.3. The saltwater prawn under
the microscope
What comes out of the egg is known as
a nauplius larva. Use the pipette (Fig 2,
22a) to put some of them on a slide for