316 PRESENT STATE OF OllGANlC ELECTlllGlTY. 



development of tlie carpellary leaf, but of the cortical layer of 

 the receptacle, and of the end of the peduncle) it is not due to 

 the same causes ^\•hich produce the general superficial, or 

 cortical axial current in the phant. 



Are the Currents ivhicli affect the Galvanometer derived from 

 Currents which actually exist in the Plant ? or are tliey j^ro- 

 duced ly the Insertion of the Electrodes ? — M. Becquerel ex- 

 presses himself very cautiously on this point ; and blames 

 certain physicists for entertaining inexact ideas regarding the 

 currents obtained from organised bodies by the galvanometer 

 platinum wires ; and for assuming that such currents are 

 necessarily derived from other currents which actually exist 

 in the plant. But M. Becquerel adds,* somewhat inconsist- 

 ently with his own admissions in other parts of his memoirs, 

 that nothing at present authorises an induction of this kind. 

 The effects, he states, appear to be due, at least in most cases, 

 to the reaction of different liquids in contact with the elec- 

 trodes ; from which results such a disengagement of electricity, 

 as that the liquid, which comports itself as an acid in relation 

 to the other, sets free positive electricity. 



At the same time, M. Becquerel admits that the two neces- 

 sary conditions for the production of primary currents exist 

 in the plant. The first is, that two liquids capable of acting 

 chemically on one another should be arranged so as to do so 

 gradually and continuously, or that there should be, as M. 

 Becquerel expresses it, "le contact des deux liquides per 

 transition insensible." The other is the intermedium of a 

 conducting texture, or substance to complete the circuit. M. 

 Becquerel, accordingly, both in his memoirs f and in his 

 abridgments in the Comptes Bendus,X seems inclined to admit 

 the two axial currents, and the horizontal system in the stem 

 and branches of the dicotyledonous plant. Beyond this he 



* Mem. dc I'Acad. des Sciences, torn, xxiii. t Ibid. 



+ Comjites Rendus, torn. xxxi. xxxii. 



