84 DR. FARADAY'S EXPERIMENTAL RESEARCHES IN ELECTRICITY. 



all bodies subject to the law of liquido-conduction are decomposable. I incline, how- 

 ever, to believe, that a portion of protiodide of mercury is retained dissolved in the 

 periodide, and that to its slow decomposition the feeble conducting power is due, 

 Periodide would be formed, as a secondary result, at the anode ; and the mercury at 

 the cathode would also form, as a secondary result, protiodide. Both these bodies would 

 mingle with the fluid mass, and thus no final separation appear, notwithstanding the 

 continued decomposition. 



692. When perchloride of mercury was subjected to the voltaic current, it did not 

 conduct in the solid state, but it did conduct when fluid. I think, also, that in the 

 latter case it was decomposed ; but there are many interfering circumstances which 

 require examination before a positive conclusion can be drawn. 



693. When the ordinary protoxide of antimony is subjected to the voltaic current in 

 a fused state, it also is decomposed, although the effect from other causes soon ceases 

 (402. 802.). This oxide consists of one proportional of antimony and one and a half 

 of oxygen, and is therefore an exception to the general law assumed. But in working 

 with this oxide and the chloride, I observed facts which lead me to doubt whether 

 the compounds usually called the protoxide and the protochloride do not often con- 

 tain other compounds, consisting of single proportions, which are the true proto com- 

 pounds, and which, in the case of the oxide, might give rise to the decomposition 

 above described. 



694. The ordinary sulphuret of antimony is considered as being the compound with 

 the smallest quantity of sulphur, and analogous in its proportions to the ordinary 

 protoxide. But I find that if it be fused with metallic antimony, a new sulphuret is 

 formed, containing much more of the metal than the former, and separating distinctly, 

 when fused, both from the pure metal on the one hand, and the ordinary grey sul- 

 phuret on the other. In some rough experiments, the metal thus taken up by the 

 ordinary sulphuret of antimony was equal to half the proportion of that previously in 

 the sulphuret, in which case the new sulphuret would consist of single proportionals. 



695. When this new sulphuret was dissolved in muriatic acid, although a little 

 antimony separated, yet it appeared to me that a true protochloride, consisting of 

 single proportionals, was formed, and from that, by alkalies, &c., a true protoxide, 

 consisting also of single proportionals was obtainable. But I could not stop to ascer- 

 tain this matter strictly by analysis. 



696. I believe, however, that there is such an oxide ; that it is often present in 

 variable proportions in what is commonly called protoxide, throwing uncertainty 

 upon the results of its analysis, and causing the electrolytic decomposition above 

 described. 



697. Upon the whole, it appears probable that all those binary compounds of ele- 

 mentary bodies which are capable of being electrolyzed when fluid, but not whilst 

 solid, according to the law of liquido-conduction (394.), consist of single proportionals 

 of their elementary principles ; and it may be because of their departure from this 



