I remember going to school with a girl that used to go swimming at an indoor pool every morning before she came to school. She had done this for so long that her hair actually turned green, and her original hair color was blond. I guess she was exposed to a little too much chlorine.

Discovered in 1774 by Swedish pharmacist Carl Scheele chlorine can be found in a liquid, solid or as a greenish-yellow gas. Chlorine is of the most effective and economical germ-killers known today. Several years ago I had to evacuate a small town because of a chlorine leak. Chlorine can be extremely dangerous. Inhalation of high concentrations of chlorine gas can rapidly lead to respiratory distress with airway constriction and pulmonary edema.

This is one of the halogens and is among the most useful of the elements as far as humans are concerned. Clorine has many uses but disinfectant is a major use. Clorine is highly reactive and thus in certain quantities can be dangerous to living things. We therefore use it to kill organisms in drinking water, swimming pools etc. If you ever go camping, take a little bottle of household bleach with you, just a small bottle. If you need to drink untreated water, treat it with a few drops of bleach. Clorine gas was used as a weapon in WWI. It is a yellow cloud. Clorine is easy to make. Just get a big bottle of household bleach, pour it into a bucket, pour in some nitric or sulfuric acid and stand back. The clorine gas just rolls out of the bucket. (DON'T BREATHE IT!)