52 Mr. Faraday on two new compounds 
posed, muriatic acid will be liberated, and charcoal left. The 
sublimed portion is then to be dissolved in alcohol, and 
poured into a weak solution of potash, by which the substance 
is thrown down, and the muriatic acid neutralized and sepa- 
rated : then wash away the potash and muriate by repeated 
affusions of water, until the substance remains pure ; collect 
it on a filter, and dry it, first between folds of paper, and 
afterwards by sulphuric acid in the exhausted receiver of the 
air-pump. 
It will now appear as a white pulverulent substance ; and 
if perfectly pure, will not, when a little of it is sublimed in a 
tube, leave the slightest trace of carbon, or liberate any mu- 
riatic acid. A small portion of it dissolved in ether, should 
give no precipitate with nitrate of silver. If it be not quite 
pure, it must be re-sublimed, washed, and dried until it is 
pure. 
This substance does not require the direct rays of the sun 
for its formation. Several tubes were filled with a mixture 
of one part of olefiant gas with five or six parts of chlorine, 
and placed over water in the light of a dull day ; in two or 
three hours there was very considerable absorption, and 
crystals of the substance were deposited on the inside of the 
tubes. I have also often observed the formation of the 
crystals in retorts in common day light. 
A retort being exhausted, had 12 cubic inches of olefiant 
gas introduced, and 24.75 cubic inches of chlorine : as soon 
as the condensation occasioned by the formation of the fluid 
had taken place, 21.5 cubic inches more of chlorine were 
passed in, and the retort set aside in a dark place for two 
days. At the end of that time muriatic acid gas and the solid 
