| Operating method
Half-fill a test tube with finely crushed sulphur. First heat it very gently to melt the sulphur until a light yellow liquid is formed.
Then heat this liquid gradually: the colour turns brown and the viscosity increases until the tube can be turned upside down without the liquid running.
Continue heating until a brownish red liquid is obtained.
Pour the reddish-brown liquid quickly into a fine net in a beaker three-quarters full of cold water (this operation is known as dipping).
Using metal tongs, remove the mass of sulphur from the water and stretch it gently.
Between your thumb and your index finger, squeeze a small piece of plastic sulphur.
Compare the plastic sulphur obtained with the crushed sulphur. After the experiment, do not try to clean the test tube. Throw it away.
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