j. 0,1 c position, given in the third and fifth parts of these Research^ The expressions I would now alter are those which conce: the independence of the evolved elements in relation to t] poles or electrodes, and the reference of their evolution • powers entirely internal (260, 273, 397). The present pa,p fully shows my present views; and I would refer to paragrap] 626, 639, 645, 652, 653, 682, 698, 743, 767, etc., as stating whj they are. I hope this note will be considered as sufficient : the way of correction at present; for I would rather def< revising the whole theory of electro-chemical decompositic until I can obtain clearer views of the way in which the pow< under consideration can appear at one time as associated wit particles giving them their chemical attraction, and at anotlic as free electricity (229, 692).—M. F. March 31,1834. VII1 § 9. ON THE SOURCE OF POWER IN THE VOLTAIC PILE. *f[ EXCITING ELECTROLYTES, ETC.,, BEING CONDUCTORS O THERMO AND FEEBLE CURRENTS. ^f ii. INACTIVE CO IS DUCTING CIRCLES CONTAINING AN ELECTROLYTIC FI/LJir ^f iii. ACTIVE CIRCLES EXCITED BY SOLUTION OF SULPHITRE1 OF POTASSIUM, ETC. § 9. On the Source of Power in the Voltaic Pile 78:j. WHAT is the source of power in a voltaic pile? Tlii question is at present of the utmost importance in the theory and to the development of electrical science. The opinion held respecting it are various; but by far the most importarr are the two which respectively find the source of power ii contact, and in chemical force. The question between then touches the first principles of electrical action; for the opinion: .are in such contrast, that two men respectively adopting their are thenceforward constrained to differ, in every point, respect- ing the probable and intimate nature of the agent or force or which all the phenomena of the voltaic pile depend. 785. The theory of contact is the theory of Volta, the greal discoverer of the voltaic pile itself, and it has been sustained since his day by a host of philosophers, amongst whom, in 1 Sixteenth Series, original edition, vol. ii. p. 18, igation of the theory of the voltaic pile than a