Scienze e Viaggi

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.