1835.] Decolourizing Combinations of Chlorine. 349 



Although it is more difficult of decomposition than the 

 oxides of chlorine, I have seen it detonate while conveying 

 it from one vessel to another. It is proper to add the nitrate 

 of lime cautiously, in order that the heat developed during 

 the solution of the salt be moderate. I have seen the gas 

 detonate from this cause. 



Exposure to a weak light for some hours did not affect it, 

 but the solar light decomposes it in a few minutes, without 

 detonation. 



Oxygen and chlorine have no action upon chlorous acid 

 gas. Hydrogen does not act upon it at common tempera- 

 tures, but if a lighted candle is brought in contact with a 

 mixture of these gases, a strong detonation is produced, and 

 white vapours of muriatic acid gas appear. 



I have not tried the effect of boron and silicon upon it, 

 but I have determined the action of bromine and iodine, 

 which form with it chloric and bromic acids, and chlorides 

 of bromine and iodine, without detonation. 



Sulphur, selenium, phosphorus, and arsenic, have the same 

 action, but are decomposed violently with much light, and 

 give rise to sulphurous, selenious, or selenic, phosphoric 

 and arsenic acids, with some free chlorine. When we 

 operate with charcoal there is a detonation, but the gas 

 produced is a mixture of oxygen and chlorine, and contains 

 very little carbonic acid. This decomposition appears to be 

 produced by the absorption of the gas in the pores of the 

 charcoal. 



The metals act differently with chlorous acid gas, according 

 to the circumstances in which they are brought in contact. 

 If fragments of different metals, enveloped in varnished 

 paper, be introduced into a narrow vessel containing a 

 small quantity of chlorous acid, complete absorption takes 

 place in the course of a few minutes, without detonation. 

 An oxide and chloride are formed at the same time. But, 

 if the quantity of chlorous acid amounts to some cubic inches, 

 the absorption, which begins very gently, terminates by a 

 detonation with disengagement of light, and in the upper 

 part of the vessel we find a mixture of chlorine and oxygen. 

 It is probable that the heat developed in this case by the 

 chemical action, produces the decomposition of that portion 

 of the gas which has not yet been absorbed. Silver leaf 

 acts also in a certain time upon chlorous acid. The metal 



