is said to have been formed by the decomposition of Chlorine . 171 
riatic acid gas on metals, it must have been the chlorine , or the 
metal , or both, that were decomposed. As chlorine can be 
freed from much of its aqueous vapour by dry muriate of lime, 
which is not the case with muriatic acid gas, it offers a much 
more unexceptionable substance for experiments of this kind. 
I passed 23 cubical inches of chlorine slowly through dry 
muriate of lime into a flint glass tube red hot, containing a 
green glass tube full of iron wire ; the chlorine combined with 
this iron wire with intense heat ; the bright sublimate formed 
was passed through more iron wire heated to redness, so as 
to form a considerable quantity of the first compound of chlo- 
rine with iron, which, when examined, was found exactly the 
same as that produced by the action of muriatic acid gas on 
iron. All the products were heated strongly, and the end of 
the glass tube kept very cool ; but not the slightest appearance 
of moisture was perceptible. 
In all these experiments I was assisted by Mr. Faraday 
of the Royal Institution. 
Muriate of ammonia is not altered by being passed through 
porcelain or glass tubes heated to redness, but if metals be 
present, it offers similar results to muriatic acid gas. In one 
experiment, in which muriate of ammonia recently sublimed 
was used, instead of muriatic acid gas, the appearance of 
moisture was less than in the experiment on muriatic acid 
gas, which has been just detailed, and yet there was a consi- 
derable action on the oxide of lead in the glass, not only by 
the muriatic acid, but likewise by the free hydrogen of the 
decomposed ammonia. 
