ELECTROLYSIS OF WATER WITH CARBON 

 ELECTRODES. 



By Edward Godfrey Bryant, B.A., B.Sc. 



It has been known for many years that when graphite is 

 treated for several days, with a mixture of nitric acid and 

 sulphuric acid or some other powerful oxidising mixture, at a 

 gentle heat, it i's partly converted into a substance known as 

 graphitic acid (C n H 4 5 ) This substance forms pale yellow 

 crystalline plates, somewhat soluble in water, and the solution 

 has an acid reaction, reddens litmus, and combines with bases. 

 Under the same conditions charcoal is converted into a brown 

 soluble substance of unknown or indefinite composition. 

 Berthelot proposed to found upon this a method for estimating 

 the amounts of charcoal and graphite respectively in any sample 

 of carbon. 



The object of this paper is to describe an entirely 

 different method of preparing the above compounds or others 

 very similar to them, for I have had no means of proving that 

 the compounds prepared by me have precisely the same com- 

 position as graphitic acid. If a high tension current is passed 

 between two pieces of carbon placed in a vessel of water, the 

 water soon begins to acquire a brown tint and to become a 

 fairly good conductor. This occuris even in distilled water, 

 though the action is then extremely slow, and many hours 

 elapse before any appreciable action begins. The negative 

 carbon is entirely unaffected, while the anode is gradually used 

 up ; fragments are torn off from it and collect at the bottom of 

 the vessel. The amount of oxygen given off at the anode is 

 notably less than it should be as compared with the hydrogen. 



In my experiments a voltage of 250 was used and the 

 current, inappreciable at first, gradually rose to an apparent 

 maximum of about -± T) ampere per sq. inch of carbon surface, 

 the carbon poles being 2 to 3 inches apart. After 24 hour- the 

 chemical action on the carbon almost ceased, judging from the 

 colour of the solution, which remained practically stationary 

 after that period. If the current was now stopped and the 

 positive carbon placed in fresh water the brown compound 

 could be dissolved out of it in small quantity for days after- 

 wards, seeming to show that it had been formed right inside 

 the carbon itself and formed, too, more quickly than the water 

 could dissolve it. 



The first trial was made on electric light carbons, which 

 had been placed in a vessel of water for the purpose of forming 

 a simple resistance arrangement. In order to ascertain whether 

 the substance thus formed was really due to electrical action 

 between carbon and water, two hard battery carbons were next 

 tried with precisely similar result. Afterwards gas carbon, 

 pure graphite, and wood charcoal were tried, and all were acted 

 upon, though not to the same extent. 



