on the Nature and Properties of Albumen, S^c, 89 



(17.) "1 two cups, connected by filaments of moistened cotton, 

 and placed, by means of platinum wires, in communication 

 with the battery of 30 pairs (16.) in the positive cup, which 

 I shall call A : a considerable deposit of albumen had appeared, 

 the contents being acid and smelling of chlorine, whilst the 

 contents of the negative cup, B, were limpid and alkaline. The 

 connexion with the battery was now reversed, so that B be- 

 came the positive, and A the negative cup. In a quarter of 

 an hour the contents of A were found to be alkaline and 

 limpid, the albumen that had been deposited having been taken 

 up, whilst the fluid in B had in its turn become turbid (from, 

 the coagulation of albumen) acid, and had acquired an odour 

 of chlorine. The rationale of this interesting experiment is too 

 obvious to require any explanation. 



20. The above experiments having been repeated many 

 times, and always with the same results, we may safely de- 

 duce from them the inference, that whenever albumen is 

 coagulated under electric agency, an acid (hydrochloric ?) 

 mixed with chlorine is always set free at the positive, whilst 

 an alkali (soda?) as constantly appears at the negative elec- 

 trode. Mr. Brande {Op. sup. cit., p. 315 el seq.) arrived at 

 nearly similar results, differing, however, in this, that he found 

 the coagulation of albumen to take place almost constantly at 

 the negative electrode ; on which circumstance, at the sugges- 

 tion of the late Sir Humphry (then Mr.) Davy, he founded a 

 theory of the coagulation of albumen. According to Mr. Brande 

 albumen owes its solubility in water solely to the presence of 

 soda ; and that in consequence of the separation of this alkali 

 at the negative electrode, the albumen is there deposited in 

 an insoluble form. Several and important objections might 

 be urged against this hypothesis, and amongst others, that 

 the proportion of soda existing combined with albumen in 

 white of egg or serous fluids is really so minute that it can 

 by no means be considered as the solvent body ; moreover, the 

 albumen of egg or serum coagulates, as is well known, by 

 heat, which is not the case with the same substance when com- 

 bined with soda ; added to which, the fact of albumen being 

 precipitated at the positive electrode by a very weak electric 

 power, is at once, I conceive, sufficient to demonstrate the un- 

 tenable nature of the position assumed by Mr. Brande ia 

 1809, and adopted by later authors. 



21. In offering an explanation of the coagulation of un- 

 combined albumen by electric currents of weak tension, I am 

 far from presuming that it is altogether unobjectionable ; but 

 still I think that it explains the circumstance of its coagula- 



Third Series, Vol. 10. No. 59. Feb. 1837. N 



