Our
experiments
We made some experiments:
- we took some milk and put
it in two glasses; a glass was put in the refrigerator and the second
was put at open. In the milk, left at environment temperature, a biological
procedure happened: it transformed the milk in acid milk while the milk,
inside the refrigerator, slowed its transformation for many days.
- the moulds: to observe
with the microscope different moulds we took some foods like a tangerine,
an apple, a wet bread and a dry bread. With the passing of time we saw
these facts: on the tangerine no moulds probably because the tangerine
was treated with some protecting substance; also on the dry bread no
moulds.
Instead on the wet bread grew a green and white moulds like a moquette
and spongy.
The moulds of the apple were gray-green like a net.
- Observation of sugar crystals,
onion cuticle and section of pine leaf.
The sugar crystals are white and with various shapes (the sugar crystals
seem cubes), the onion cuticle is like fish squamas or butterfly wings
while the section of pine leaf becomes large the triple of its length,
and inside we can see very small cells.
- The Spallanzani's infusions:
we took water, we heated it and then put in jars with seeds of: sunflower,
rice, maize, lentils. Immediately the water assumed various colors:
yellow (sunflower and maize), whith (rize), red (lentils).
A series of them was left
open, while an other series was closed down and with a large pot we boiled
them for half hour.
Spallanzani used a different
technique to protect the infusions because he did not possess jars
with
hermetic sealing hat exist now.
After the boiling the lids
did not unscrew more and they did not make more clik. This means that
the closing was perfectly watertight.
- The open infusions: after
a week we noticed that the jairs o had an unpleasant smell, they were
cloudy while the others hadn't no modifications. With the microscope
we observed some drops from the various jairs: we saw like an island
with inside some small moving dots. In an other infusion we saw some
moving ' animaletti'.
- With our microscopes the
drops were a little unclear. Sure in the infusions livings developed,
moving livings (the animaletti of Spallanzani) or fixed (similar to
moulds of the bread), however the smell were very strong!
- Obviously when we opened
the closed jairs, the infusions deteriorated.
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