Iwpregnation. 



Have plants 

 lolilion. 



EFfECX OF GAI»VAMI3H IN METALLIC ARBORIZATION. 



Impregnation, -Even when tlie flower first opens, the 

 anthers are bursl, and their burluce \* covered with pollen ; 

 but \ iamgine, lliat impregnation is not accomplij^hed, till 

 tii«- period when the stigmata hang amonj^ the aiuliers, 

 whicli, as 1 have formerly stated, happens during the 

 anthcsist or lin)e that the flower is expanded. If this be the 

 ctise, we have certainly a very striking iMustratioo of the 

 muDoer, in which thepi.vfi/A" accommodate themselves to the 

 antkerSt in order that they may be ftcundated ; and conse- 

 quently of the sexual system. —i *^ - n 



Manj' disquisitions have been instituted, regarding the 

 volition o^ plants; some admitting, while others deny, that 

 they are capable of exerting such a faculty, IJere I would 

 v^ish to ask the abettors and opponents of both hypotheses, 

 X'l the pas sio)i' flower y while performing the motiot^. de- 

 Jicribed, does not exhibit, as it were, a design to accomplish 

 certain purposes by slow but regularly continued exer- 

 tions — and of course an eifort, at least, analogous to volition ? 

 At present I leave the determinatioTJ of the question to 

 gthers. Probably at a future period I m^y recur to this 

 subject. 



I^rec'ipitatlorx 

 Qf one metal 

 ty another. 



"FoTmat'on of 

 ;lie leaUtri 



Shown to ^e 



VF. 



On the Injiuence of Galvanic Electricity in Metallic Arlori- 

 zations : by C.J.Theodore de Grottkuss.* 



Sect,\. ii HE precipitation of metals in solution, occasion- 

 ed by the, presence of .certain oiher metals, Qihibits sucl^u. 

 striking analqgy to. the chemical tvTe.ts ot\ galvanic ele^j 

 tricity, tlmt we cannot avoid the idea of one and the saqti^ 

 cause. in all tjiese phenomena. . / ,. 



Let. c y, PI. ly, fi'r. 7, be a glass tube filled , with an 

 aqueous solution of acetate. of lead ;; and 3; a piece' of zinc, 

 the lower end of which js immersed in the solution, and 

 which is fastened so as to be retained at the top of the tube. 

 Suppose the ramificationK of the arbor saturni to have 

 reached as far as wt, I ghall prove, that it increases by the 



♦ T\ntial(« de Chiniie, vol. LXIH, p 



immf^dialc 



