$8 Mr. Faraday on two new compounds 
When phosphorus is heated with the vapour of the sub- 
stance over mercury, so as not to inflame in it, there is gene- 
rally a small portion of muriatic acid gas formed. If great 
care be taken, this is in very minute quantity ; and its variable 
proportion sufficiently shows, that the hydrogen which forms 
it does not come from the substance. I am induced to believe 
that it is derived from moisture adhering to the phosphorus. 
The action of iodine on phosphorus shows, that it is very 
difficult to dry the latter substance perfectly. 
A stick of phosphorus put into the alcoholic or etherial 
solution of the perchloride did not exert any action upon it. 
Charcoal heated in the vapour of the substance appears to 
have no action upon it. 
Most of the metals decompose it at high temperatures. 
Potassium burns brilliantly in the vapour, depositing charcoal, 
and forming chloride of potassium. Iron, zinc, tin, copper and 
mercury, act on it at a red heat, forming chlorides of those 
metals, and depositing charcoal ; and when the experiments 
are made with pure substances, and very carefully, no other 
results are obtained. Some of the substance was passed over 
iron turnings heated in a glass tube. At the commencement 
of the sublimation of the chloride through the hot iron, the 
common air of the vessels was expelled, and received in 
different tubes ; but before one-third of the substance had 
been passed, all liberation of gas ceased, and the remainder 
was decomposed by the iron, without the production of any 
gaseous matters. The different portions of air that were 
thrown out being examined, the first proved to be common 
air, and the last carbonic oxide. This had resulted, probably, 
from the action of the chlorine on the lead of the glass tube. 
