Chop finely a small piece of meat, squeeze out the juice with a lemon squeezer and heat this juice in a saucepan. Observe the coagulation that takes place.
If possible, 2 glass beakers, 1 square wire net. If these are not available, use an ordinary tumbler and a small saucepan.
a. Put a small piece of meat in a beaker with cold water, and allow it to stand.
b. Bring water to the boiling point in the beaker on the net over the gas flame. Throw in a small piece of meat.
Compare the appearance of the two pieces of meat and the water in the two beakers.