Dr, Kolbe on the oxidizing poiver of Oxtjgen, ^c. 335 



On decomposing a concentrated solution of sesquichloro- 

 carbohyposulphate of potash by a sti-ong voltaic current (ob- 

 tained by four elements of Bunsen's battery), at the com- 

 mencement no hydrogen can be observed at the negative 

 pole in consequence of the formation of the above-mentioned 

 copulated acids, whilst chlorine, carbonic acid, and afterwards 

 oxygen, are evolved at the positive pole. At the moment de- 

 composition commences a distinct acid reaction of the solu- 

 tion is perceptible, owing to the formation of free hydrochlo- 

 ric and sulphuiic acids ; in a later stage of the process, these 

 acids increasing in quantity, hydrogen appears at the negative 

 pole, until finally, after all the hydrochloric acid has been de- 

 composed, and the disengagement of chlorine has ceased, 

 small octahedral crystals of perchlorate of potash are deposited 

 from the solution, which now contains a large amount of free 

 sulphuric acid and bisulphate of potash. The formation how- 

 ever of perchloric acid in this process is always preceded by that 

 of chloric acid ; for on evaporating the solution in an earlier 

 stage of the decomposition, beside the befoi'e-mentioned oc- 

 tahedral crystals, the well-known rhombic plates of chlorate of 

 potash are obtained. 



The following foi'mula represents the most probable de- 

 composition sesquichloro-carbohyposulphuric acid undergoes 

 by the action of a voltaic current : — 



rK04ci07 



KO+C2C13S205J 2S03 

 1201 2C02 

 L2C1. 



The production of perchloric acid in an acid solution is 

 certainly a fact worthy of attention, for according to all the 

 observations hitherto made, combination between chlorine 

 and oxygen could only be effected in presence of a free alka- 

 line basis ready to unite with the newly-formed acid ; but 

 ascertained as it is by a great number of careful experiments, 

 it is another proof of the unpai'alleled negative power of 

 oxygen when evolved by means of voltaic action. 



These observations induced me to malce the following ex- 

 periments. 



A neutral solution of chloride of potassium was decomposed 

 in the same manner by a strong voltaic current; it imme- 

 diately became alkaline, whilst hydrogen and chlorine were 

 disengaged. The formation of chlorate of potash, which took 

 place under these circumstances, can evidently be considered 

 only as tlic result of the ordinary chemical action of chlorine 

 upon cau.sticpota.sh. On mixing however a solution of chloride 

 of potassium with suflicient sulphuric acid to set free all the 



