1835.] Decolourizing Combinations of Chlorine. 269 



before we have time to filter it. The gas disengaged is 

 oxygen. I have ascertained in working directly with the 

 chlorites and oxide of silver, that chloride of silver is formed 

 and oxygen disengaged ; the latter proceeding from the 

 chlorous acid and decomposed oxygen. A portion of the 

 oxygen, is, however, absorbed by the excess of oxide in the 

 liquid, and is converted into peroxide. In order to obtain 

 the chlorites free, it is necessary, therefore, to avoid the 

 precipitation of the oxide of silver, and to operate with the 

 decolourizing chlorides without excess of alkali, the neu- 

 tralization being affected by nitric acid, carefully added, 

 however ; for, if an excess is used, the precipitate of chloride 

 of silver is speedily raised by the copious disengagement of 

 bubbles of chlorine, and the bleaching property disappears 

 in a great measure. If we attempt to separate the chloride 

 of silver quickly from the liquid, and press it in linen, a 

 very intense discharge of heat takes place. Direct experi- 

 ment has proved that chlorous acid, which in this case is 

 set at liberty, exercises on the chloride of silver the same 

 action which it produces on the other chlorides, and the 

 presence of a small excess of nitric acid increases this decom- 

 position. Hence, perfect neutrality, it is obvious, is essen- 

 tial. When this has been attained, the metallic chlorine 

 and alkaline chlorite are decomposed, the chloride of silver 

 precipitates, and the liquid possesses strong decolourizing 

 properties, owing, undoubtedly, to the chloride of silver 

 which remains in the solution. But this substance is very 

 easily decomposed, and it is impossible, even with frequent 

 filtration, to obtain a limpid solution. As chloride of silver 

 is continually depositing, the liquid diminishes in its bleach- 

 ing powers, and chlorate of potash remains. 



This process having failed, it appeared to promise success 

 to try the action of the oxide of silver upon chlorine itself. 

 Accordingly, pure oxide of silver was suspended in distilled 

 water, and agitated with chlorine. The latter was absorbed, 

 aud the portion of the oxide in contact with the chlorine 

 formed a white compound, the other portion assuming a 

 deep black tint. The first was chloride of silver ; the 

 second, peroxide of silver. In this experiment heat was 

 given out, but no perceptible quantity of oxygen. The 

 liquid, immediately after filtration, was limpid, and strongly 



