1835.] Decolourizing Comhinations of Chlorine. 431 



sist, and the number of atoms to be expressed by an entire 

 number. By multiplying the first formula by the entire 

 numbers, and arranging the atoms obtained so as to form 

 metallic chlorides and salts, with an oxide of chlorine, we 

 have the following results: — 



sidered similar in its composition to nitrous and sulphurous 

 acid. But why not admit the second, which is the most 

 simple, and consider chlorous acid similar to hypo-sulphur- 

 ous acid. Considered abstractly from all experiment, this 

 supposition is the most natural one, for the circumstances 

 in which chlorous acid is formed do not resemble those 

 under which phosphorous, nitrous acids, &c., are produced, 

 while they are identical with those which accompany the 

 formation of hypo-sulphurous acid. We know, indeed, that 

 it is in treating the alkaline oxides by sulphur, with the 

 access of water, that we obtain mixtures of one atom hypo- 

 sulphite, and one atom of hypo-sulphuret. If in this re- 

 action we substitute chlorine for the sulphur, we have one 

 atom chlorite and one atom of chloride. The only difference 

 between the two cases is that the number which expresses 

 the chemical equivalent of chlorine is double that which 

 expresses its atom, while, in sulphur, these two numbers 

 are equal. The formula of chlorous acid is Cl^, while that 

 of hypo-sulphurous acid is S. 



It is only since Soubeiran shewed the probability that the 

 protoxide of chlorine of Davy is only a mixture of protoxide 

 and deutoxide, that we could infer apriori the true composi- 

 tion of chlorous acid. 



What name ought to be given to this compound ? It is 

 evident that the term chlorous acid cannot be preserved. 

 It is better, therefore, to call it hypo-chlorous acid, which will 

 shew its analogy with hypo-sulphurous, hypo-phosphorous 

 acids, &c., composed of one atom of each element. The 

 name chlorous acid will thus be reserved for a compound 

 yet unknown, of 2 volumes chlorine -h 3 oxygen ; and that 



