90 Mr. Golding Bird's Experimental llesearcfics 



tion in a manner more consistent with known facts than any 

 other I have yet met with. 



22. I conceive it will be granted by every one at all ac- 

 quainted with the true nature of electro-chemical decomposi- 

 tion, that a solution oF albumen free from the minutest trace 

 of saline or other admixture, would not be affected by a cur- 

 rent of electricity (premising that all sources of error arising 

 from the evolution of heat are avoided) of any degree of ten- 

 sion insufficient for its disintegration and resolution into its 

 ultimate atoms ; for, like sulphuric acid, soda, or other ions^, 

 when wicombined it can have no possible tendency to pass to 

 either electrode ; but when combined with an alkali, and 

 playing the part of an electro-negative or acid body, and be- 

 coming an anion, we should expect it to pass to the positive 

 electrode [aiiode) ; or when acting as a base, becoming a cat- 

 ion, to pass to the negative electrode [cathode). How then 

 does an electric current effect the coagulation of albumen ? 

 Not at all, I believe, by a primary action upon it, but solely 

 by secondary effects, and in the following manner. Fluid al- 

 bumen can never be obtained perfectly free from chlorides, 

 for common salt always exists intimately mixed with it; and 

 even if this could be entirely removed, still, as Raspail has 

 shown [Nouv. Syst. de Chim» Org., p. 195), the hydrochlorateof 

 ammonia is always present. Then on submitting fluid and as 

 far as we can obtain it, uncombined albumen to voltaic action 

 (by means of platinum electrodes), the saline matter present 

 is decomposed, and this consisting chiefly of chlorides of the 

 alkaline metals, the chlorine' passes to the positive, the bases 

 to the negative electrodes. As soon as the chlorine is set free 

 in the positive cup (when two are used, or in the proximity 

 of the positive electrode when one cup only is employed,) it 

 precipitates the albumen, a very minute pordon of chlorinef 

 being sufficient to precipitate a considerable quantity of albu- 

 men ; whilst the bases in the negative cup combine with the 

 albumen ; so that at the termination of every experiment of this 

 kind, chlorine (as indicated by the odour), hydrochloric acid, 



• It may not be altogether irrelevant to remind those who may happen 

 to be not very conversant with the researches of Faraday, that by an ion is 

 understood a body not itself composed of other ions, and having, when un- 

 combined, no tendency to pass to either electrode, being quite indifferent 

 to the passage of the current. Thus iodine, sulphuric acid, chlorine, acetic 

 acid, soda, ammonia, &c. are ions. [See Lond. and Edinb. Phil. Mag., vol. v. 

 p. 164.— Edit.] 



f Chlorine is undoubtedly the most delicate chemical reagent for the 

 detection of albumen that we possess, and I may remark that to its pre- 

 tence nitro-hydrochloric acid owes its value as a test for albumen (5.). 



