Use two glass cups of the same capacity, the left cup is filled with tap water, and the right is Yamizu water. After breaking an egg, put half of the egg into the left cup, and other half of the egg yolk into the right cup, let it stand for a few days and see what happen after some days. .
After 7 days, the egg yolk water in the glass on the left smells very foul, and the one on the right. The egg yolk water in the glass has only a slight smell, it is obviously not as bad as the egg yolk water on the left cup.