- ‘THE BLEACHING COMPOUNDS OF CHLORINE. 295 
lime gradually during its preparation, in order that the heat which is 
generated during the solution of this salt should not be too strong. I 
have frequently seen chlorous acid gas detonate by the influence of this 
cause; and although this detonation is not in itself very dangerous,— 
for the receiver, which is projected vertically, is never broken into small 
fragments,—yet the chlorous acid being then dispersed in small drops, 
which are extremely corrosive, it is prudent to prevent it. 
An exposure of some hours to a weak diffused light did not appear 
to me susceptible of altering chlorous acid; but solar light decomposes 
it in a few minutes without detonation. 
The manner in which different bodies act upon the gaseous acid is 
similar to that upon liquid chlorous acid. 
Oxygen and chlorine cannot act upon chlorous acid: hydrogen, at 
common temperatures, exerts no action upon it; but if a lighted taper 
be put to a mixture of these two gases, a loud detonation is produced, 
and white thick vapours of hydrochloric acid gas are observable. 
I have not tried what effect boron and silicium produce upon this 
gas, but I have stated what bromine and iodine can do. Ifa small 
quantity of these substances be added to a proper volume of chlorous 
acid gas, it is quickly absorbed, and chloric and_bromic acids are a 
duced, and chlorides of bromine and iodine. 
This action of bromine and iodine takes place slowly and without 
detonation. This is not the case when sulphur, selenium, phosphorus, 
and arsenic are operated with. Scarcely do these bodies come into con- 
tact with the chlorous acid gas when they decompose it with a strong 
detonation and a vivid light. The arsenic and phosphorus are con- 
verted into arsenic and phosphoric acids ; the sulphur forms sulphurous 
acid. I have not determined whether selenious or selenic acid is pro- 
duced by selenium. One part of the chlorine combines with the com- 
bustible bodies, but a notable portion i is disengaged in the gaseous state. 
This gaseous chlorine is moreover always mixed with a quantity of oxy- 
gen. When charcoal is used, there is also immediate detonation; but 
the gas obtained is a mixture of oxygen and chlorine, and contains but 
very little carbonic acid. I believe that, in this case, the decomposition 
is effected less by the affinity of the carbon for oxygen, than by the heat 
which is developed by the absorption of the gas in the pores of the char- 
coal. 
The metals act differently with chlorous acid gas according to the 
circumstances under which they are brought into contact with it. If 
fragments of several of the metals, wrapped in sized paper to prevent 
amalgamation, be passed into a rather narrow jar containing a small 
quantity of chlorous acid, it is absorbed completely in a few moments, 
and without detonation. There are formed both an oxide and a chlo- 
ride. But if the quantity of chlorous acid employed measures several 
x2 
