302 SCIENCE PROGRESS. 



sium acetate to electrolysis, and found that methyl (ethane) 

 was one of the products. Now, the formation of this sub- 

 stance was quite in accordance with the chemical theory of 

 that day which regarded acetic acid as a paired compound 

 of methyl and oxalic acid. Using the chemical symbols with 

 their modern value, we should write Kolbe's acetic acid 

 thus : C 2 H 6 'C 2 H 4 2 . It was expected that when this was 

 decomposed by electricity, the acid, which always plays the 

 part of an electronegative constituent, would travel to the 

 positive pole, and the methyl to the negative pole. But 

 oxygen, due as was then supposed to the direct electrolytic 

 decomposition of water, always appeared at the positive 

 pole, so that the oxalic acid which was there liberated 

 would be liable to oxidation ; « and since oxalic acid is a 

 readily oxidisable substance it might be expected that' its 

 oxidation product, carbonic acid, would appear in its 

 place, which was in fact found to be the case. But besides 

 these gases, methyl, or as we now say, ethane, was 

 also evolved at the same pole, in direct contradiction of 

 the above theory of the constitution of acetic acid, accord- 

 ing to which the ethane should have appeared at the 

 opposite pole. From this pole only hydrogen was lib- 

 erated. We shall presently see the modern way of ex- 

 plaining the reaction, but it is of some importance to 

 understand the older mode of conceiving the process which 

 went on at the positive pole, for it led to the erroneous 

 notion that the formation of synthetical products there was 

 due to oxidation, an idea which has not yet been wholly 

 abandoned, although all recent work on the subject is at 

 variance with it. 



At the present day, and on the basis of the researches 

 of Faraday and Hittorf, we conceive the phenomenon of 

 the passage of an electric current through an electrolytic 

 solution somewhat as follows. Whilst in a metallic con- 

 ductor the electricity flows through matter, in an electro- 

 lytic conductor it flows with, and is carried by, matter. We 

 imagine a continuous double procession of particles carrying- 

 electricity between the two poles or electrodes, the particles 

 with negative electricity moving towards the positive 



