428 M, Balard on the Nature of the [Dec. 



and we may conclude, from this as well as the preceding 

 experiments, that chlorous acid is composed of two volumes 

 of chlorine and one of oxygen. In another experiment, by 

 detonation, from 45 parts of the gas, 69 parts of a gaseous 

 mixture were obtained, which were reduced to 23 parts on 

 being agitated with an alkaline solution. This result not 

 only justifies the correctness of the other experiments, but it 

 enables us to appreciate the condensation which the chlo- 

 rine and oxygen undergo when they unite to form chlorous 

 acid. 



We see that this condensation is one-third of the whole 

 volume, and equal to that of the oxygen which enters into 

 its composition. 



The analysis of chlorous acid proves its composition to be 

 the same as the gas obtained by the chlorate of potash and 

 muriatic acid, which chemists have long considered as the 

 protoxide of chlorine. If it should be demonstrated that 

 this product is really distinct, as it differs much from chlo- 

 rous acid, which has been described, these two bodies will 

 afford a new example of isomerism. But the researches of 

 Soubeiran have rendered it probable that the protoxide is a 

 mixture of chlorine and deutoxide of chlorine. The com- 

 position of chlorous acid, as before deduced, differs much 

 from that assigned to it by chemists. Liebig, in determin- 

 ing the action of the decolourizing compounds of chlorine 

 upon the sulphurets of barium, lead, &c., has found them 

 immediately, changed into sulphurets, without disengage- 

 ment of chlorine or precipitation of sulphur. 



Now, in order to change one atom of these sulphurets 

 into a sulphate, four atoms of oxygen are necessary, three 

 to form the acid and one to form the base. Liebig supposed 

 that this effect was produced by one atom of chlorite ; and, 

 as the base of this chlorite could have only yielded one 

 atom, he concluded that the three were furnished by the 

 chlorous acid. On the other hand, the atom of the metallic 

 base exists in the liquid in the state of muriate ; two atoms 

 of chlorine are therefore required to form this compound. 



Chlorous acid would appear, therefore, to consist of two 

 atoms chlorine and three of oxygen. But we have only to 

 suppose that two atoms of this acid were required to convert 



