2745 balard's uesearciies concerning the nature of 



chloric acid. Altliougli this fact may be consistently explained by sup- 

 posing that the presence of a chloride of an oxide in the saturated so- 

 lution of chloride of potassium has diminished, in this case, the solvent 

 power of the liquid with respect to this compound, and that the salt 

 which is obtained is only a portion of that which previously existed in 

 the liquor, and thus is not produced by the action of the chlorine, as 

 supposed by Berzelius, the first explanation is yet the most probable, 

 and induces the belief that metallic chlorides exist ready formed in the 

 decolorizing compounds. 



M. Soubeiran has confirmed this fact by an experiment which 

 appears to me to be at present the only one not liable to objections. 

 After having determined, by a preliminary trial, the intensity of the 

 decolorizing power of a given volume of chloride of soda, he evaporated 

 it in vacuo to dryness. He has stated that during the e\;uporation 

 cubic crystals of chloride of sodium are formed, which may be sepa- 

 rated in a state of perfect purity ; and that the remaining solid residue 

 dissolved in water and tested with a coloured but not acid liquor, 

 possessed absolutely the same decolorizing power as the liquid from 

 which it was procured. This decolorizing power not liaving suffered any 

 diminution, it cannot be admitted that the chloride of sodium obtained 

 was the product of the decomposition of the decolorizing compound. 

 This chloride of sodium, therefore, existed in the solution of the alka- 

 line chloride before its evaporation. If, then, in acting upon an alkali,' 

 the chlorine had formed chloride of sodium, without the production of 

 a corresponding quantity of chlorate, of oxygenated water, or of gas- 

 eous oxygen, it necessarily follows that an oxygenated compound was 

 fonned, different from chloric acid. 



The crystallization of chlorite of soda in vacuo, led M. Soubeiran to 

 hope that he should succeed in isolating chlorous acid. But the con- 

 tinuation of his researches, although announced three years since, has 

 not yet been published. 



It will be observed, from ^hat has preceded, that there may still 

 exist among chemists some indecision as to the choice Avhich may be 

 made between the two hj^otheses proposed as to the nature of the 

 decolorizing compounds of chlorine. Although the hypothesis of 

 chlorites is by much the most probable, it is nevertheless true, that not 

 only chlorous acid has not been obtained in a free state, but even 

 chlorites also; they not having been yet procured, but in a state of 

 mixture with the metallic chlorides. 



Thus, although ^•ery probable, the existence of these salts is far 

 from being demonstrated, and the composition of chlorous acid, which 

 was supposed to be formed of two volumes of chlorine and three 

 volumes of oxygen, remains undecided. 



It appeared, tlierefore, to me desirable to attempt some fresh expe- 

 riments, with the endeavour of elucidating a tiieoretical chemical 



