1835.] Decolourizing Combinations of Chlorine. 427 



filled with chlorous acid, and hermetically sealed, was in- 

 troduced into it. The flask was closed, and then agitated 

 so as to break the globe. When the chlorous and muriatic 

 acid came in contact, the decomposition took place with dis- 

 engagement of heat, and the interior of the flask assumed 

 a yellow colour. When the latter was preserved at the 

 temperature of the atmosphere, it was opened over mercury, 

 without a single drop of the liquid entering, or a bubble of 

 the gas escaping. The gas which filled it was completely 

 absorbed by the mercury. Muriatic acid, in its decomposi- 

 tion by chlorous acid, is transformed into a volume of chlo- 

 rine exactly equal to itself. Now, in this volume of muri- 

 atic acid, there was half a volume of hydrogen ; the chlo- 

 rous acid which had changed this hydrogen, into water, 

 had, therefore, yielded a fourth of its volume of oxygen. 

 On the other hand, the decomposed muriatic acid could 

 only give half a volume of chlorine, and as a whole volume 

 had been produced, the other half volume must have been 

 furnished by the chlorous acid. The latter was, therefore, 

 obviously, composed of two volumes of chlorine and one 

 volume of oxygen. 



It was possible, however, that this method of analysis, 

 which appears as simple as it is elegant, might have been 

 vitiated by a single circumstance, viz. that the heat deve- 

 loped might have disengaged, in the gaseous form, a portion 

 of chlorous acid, which would be completely absorbed by 

 the mercury. The gas disengaged would not, therefore, 

 be equal to that of the muriatic acid employed. 



It had been noticed that concentrated sulphuric acid, in 

 acting upon liquid chlorous acid, disengaged, besides pure 

 chlorous acid, gaseous products. It was considered proper 

 to determine in what proportion chlorine and oxygen were 

 disengaged. For this purpose, 50 parts, by volume, of this 

 gas, were submitted to the action of heat,in order to produce 

 detonation ; 72 parts were the result, which, on being 

 treated by an alkaline solution, were reduced to 25 parts 

 oxygen gas. 



If allowance is made for the mode of experiment in which 

 a small portion of the chlorine is necessarily absorbed by 

 the mercury, the loss sustained is easily accounted for : 



