green), with a powerful and suffocating odor, and is wholly irrespirable.
Even when much diluted with air, it produces the most annoying irritation
of the throat, with stricture of the chest and a severe cough,
which continues for hours, with the discharge of much thick mucus.
The attempt to breathe the undiluted gas would be fatal; yet, in a very
small quantity, and dissolved in water, it is used with benefit by patients
suffering under pulmonary consumption.

Under a pressure of about four atmospheres, it becomes a limpid
fluid of a fine yellow color, which does not freeze at zero,
and is not a conductor of electricity. It immediately returns
to the gaseous state with effervescence on removing the pressure.

Water recently boiled will absorb, if cold, about twice its bulk
of chlorine gas, acquiring its color and characteristic properties.
The moist gas, exposed to a cold of 32 deg., yields beautiful yellow crystals,
which are a definite compound of one equivalent of chlorine and ten of water.
If these crystals are hermetically sealed up in a glass tube, they will,
on melting, exert such a pressure as to liquefy a portion of the gas,
which is distinctly seen as a yellow fluid, not miscible with the water
which is present. chlorine is one of the heaviest of the gases,
its density being 2.47, and 100 cubic inches weighing 76.5 grains.

Chlorine Water.--This combination, which is used in conducting
M. Neipce's process, can be readily prepared by conducting
the gas into a bottle containing distilled water.
One part water dissolves two parts of chlorine.

Chlorides.--The metallic chlorides are nearly all soluble in water;
that of silver and protochloride of mercury being the only exceptions.