RECENT PROGRESS IN PHYSICS. 389 



to the chloric or hyperchloric acid, by the long continued electrolysis 

 of cyan ate of potassa; neither did a solution of fluoride of potassium 

 yield an oxygen compound of fluorine. 



Kolbe also succeeded in obtaining products of oxydation from 

 sesquichloro-carbohypo-sulphuric acid, HO -\- C^ ^h ^2 O5) ^7 nieans of 

 the current, (Liebig's Ann., vol. 54, p. 157 ; Philos. Magaz., XXX, 

 334,) while this acid, under other circumstances, resists the most 

 powerful oxydizing agents, so that it may be boiled with chromic or 

 nitric acid, &c., without undergoing any change. 



When a concentrated solution of sesquichloro-carbohypo-sulphate of 

 potassa is exposed between platinum electrodes to the current from a 

 battery of 4 Bunsen's cups, at first no hydrogen is evolved at the 

 negative pole, while chlorine, carbonic acid, and, afterwards, oxygen, 

 are evolved at the positive pole. 



As soon as the decomposition commences, an acid reaction of the 

 solution is perceptible, owing to the formation of free muriatic and 

 sulphuric acids. In a later stage of the process, these acids increasing 

 in quantity, hydrogen appears at the negative pole_, until, finally, 

 after all the muriatic acid has been decomposed, and the evolution of 

 chlorine has ceased, small octahedral crystals of per-chlorate of potassa 

 are deposited from the solution, which now contains free sulphuric 

 acid and bi-sulphate of potassa. 



These results may be explained in the following manner : The 

 oxygen, liberated at the positive pole in consequence of the decompo- 

 sition of water, acts upon the acid, and causes its separation into 

 difterent compounds. Tbe oxydation of the acid is complete when it 

 has taken up 12 equivalents of oxygen; the decomposition may then be 

 represented as follows : 



f KO + CIO7 

 KO -f C2CI3S2O ' 2SO3 

 12 6 J 2 CO, 



[2 cr 



There are formed, therefore, per-chlorate of potassa^ sulphuric and 

 carbonic acid^ and free chlorine; but the formation of per-chloric acid 

 does not take place in the first instance, for in tlie beginning of the 

 process chloric acid is produced. If the fluid is evaporated in the 

 earlier stage of the decomposition before the crystalization of the per- 

 chlorate of potassa commences, the well known rhombic plates of 

 chlorate of potassa are obtained. 



While the oxygen evolved at the positive pole produces these 

 oxydizing eff'ects, no gas escapes at the negative, since the hydrogen 

 there liberated also enters into several combinations. One part of 

 this hydrogen replaces one or two equivalents of chlorine, and forms 



acids HO + ( ^ ) nf )^2 ^s) Chloro-formyl-hypo-sulphuricacid, and 



HO + ( ) C\}^^ ^^' Chloro-elayl-hypo-sulphuric acid — two acids 



which are described by Kolbe in vol. 54 of Liebig's Annals. Anotber 

 part of the hydrogen combines with the liberated chlorine and pro- 



