156 Litelligence and Miscdhmeons Articles, 



do not destroy colour, except by tlie intervention of an acid, but 

 the others decolorize instantly, like free chlorine. 



4th. The chlorites, even when mixed with metallic chlorides, 

 possess all the characteristic properties which distinguish them from 

 the decolorizing chlorides of oxides ; and, amongst others, that of 

 the disengagement of chlorous acid, on the addition of acids, instead 

 of chlorine, which, under these circumstances, is evolved from the 

 chlorides of oxides. 



5th. The chlorites are analogous to the hypochlorites of M. 

 Balard as regards their decolorizing and oxidizing power, but are 

 much more stable. 



6th. Although the hypochlorites, mixed with metallic chlorides, 

 disengage only chlorine by the addition of acids, as M. Balard has 

 rightly observed, and are in this respect analogous to the decolor- 

 izing chlorides of oxides, it need not necessarily be inferred that 

 their chemical constitution is the same, since hypochlorous acid 

 itself, acting on a metallic chloride, evolves only chlorine. We may, 

 moreover, compare this phjenomenon to that of many other ana- 

 logous chemical actions, and, amongst others, to the fact stated 

 long since by Gay-Lussac, that a mixture of iodate and iodide of 

 potas^sium, when acted on by even the weakest acids, disengages 

 iodine ; that also which is presented to us by a mixture of chlorate 

 and chloride of potassium, whic h readily decomposes with the si- 

 multaneous evolution of chlorous acid and chlorine, by the ac- 

 tion of acids so much diluted that they had no action on either of 

 the compounds of the mixture taken separately. All these actions 

 may be easily represented and explained by atoniic formulae, 



7th. By dii'tilling the chlorides of soda and potash supersaturated 

 with chlorine, hypochlorous acid is produced, the residue being a 

 neutral metallic chloride. This is a new and simple method of ob- 

 taining this acid, which has hitherto only been obtained by the ac- 

 tion of certain insoluble metallic oxides on chlorine with the inter- 

 vention of water. 



8lh. Red oxide of mercury does not present so many advantages 

 for the preparation of hypochlorous acid, because it may form an 

 insoluble oxichloride, which renders the chloride of oxide of mer- 

 cury, though easy to obtain, unstable, and readily causes its con- 

 version into hypochlorous acid and an insoluble oxichloride j so 

 that this chloride of an oxide may give rise to hypochlorous acid 

 without heing supersaturated with chlorine. 



9th. The dec(^lorizing chlorides of potash and soda, when they 

 have excess of base, may be evaporated without decomposing, and 

 even heated to 212° Fahr., without losing their decolorizing power, 

 which is not the case with the hypochlorites, and indicates a differ- 

 ent composition. 



10th. The production of hypochlorous add, by the distillation of 

 the chlorides of potash and soda, supersaturated with chlorine with- 

 out an alkaline residue, can be but little understood by the hypo- 

 thesis that these decolorizing chlorides consist of hypochlorites 

 mixed with metallic chlorides, although it may be easily deduced 



