THE BLEACHING COMPOUNDS OF CHLORINE. 29S 



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 diiferent 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. If a small 

 quantity of these substances be added to a proper volume of clilorous 

 acid gas, it is quickly absorbed, and chloric and bromic acids are pro- 

 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 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 



