1876.] 



and Electrolysis in Chemical Compounds, 



323 



tution, and to ascertain if the presence of hydrogen in the compound 

 (and hj^drogen can easily be replaced by other substances, especially 

 metals) is connected with the liability to electrolysis. 



Though in former years some experiments were made in this way in 

 Germany, I hare now had the opportunity of extending them very much, 

 as I used the compounds which modern organic chemistry has taught us 

 since to prepare. It is also important to remark that I only tried sub- 

 stances which are in a fluid condition, or can be reduced to it without 

 requiring a solvent. It is sufficiently known that the solvent generally is 

 electrolyzed at the same time, and the results become very complicated ; 

 therefore the gases in their liquefied state were especially fit for exami- 

 nation, the more so because several of them are very often used in che- 

 mistry as powerful agents. The gases were liquefied by the method first 

 proposed by Faraday, in strong glass tubes, which had platinum wires 

 fused in at their extremities ; these ends were brought close together, at 

 a distance of 2, 3, or 4 millims., in the closed end of the tube ; this part 

 w^as, after the liquefaction took place, filled with the liquid gas. With 

 substances liquid at the ordinary temperature and pressure, the same 

 arrangement was made, but of course there was then no difficulty. I 

 successively caused a current of 10, 20, 40, and 80 galvanic cells (greatest 

 size of Bunsen's) to pass through the liquids, and connected them at the 

 same time with a very delicate galvanometer. I also used the spark of 

 an induction-coil, the length of which exceeded 75 millims. "With this 

 apparatus the condensed gases generally exploded, and the other sub- 

 stances were decomposed by the tliermal effect of the spark : it was a 

 case of dissociation. As to the galvanic current, even the strongest 

 did not pass in a perceptible way through the following compounds 

 (amongst others) : — liquid carbonic acid, liquid hydrochloric acid (nor any 

 other hydrogenated acid, as BrH, IH, with exception of CXH), liquid 

 cyanogen, bisulphide of carbon, benzine, tin tetrachloride, zinc-ethyl. 



Liquefied ammonia forms a remarkable exception; it conducts the 

 galvanic current even of a moderate battery very well, and it is at the same 

 time electrolyzed ; with a battery of 80 cells apparently a new body is 

 separated, because the liquid becomes of an intense blue colour, and much 

 gas is evolved. I shall communicate more particulars on this subject in 

 my aforesaid paper. 



Now, though it may be worthy of remark that a compound like hydro- 

 chloric acid, when in the liquid condition, opposes a formidable resistance 

 to a galvanic current, which may be called very strong in comparison with 

 those which are generally used for electrolytical purposes, I confess I was 

 not satisfied till I had tried the most powerful current that ever has 

 been produced : it is the current of the chloride-of-silver battery of Mr. 

 Warren De La Eue ; and as I proposed during my stay in London to 

 carry on this investigation, he not only most willingly consented to my 



