Account of some farther Electrical Experiments. 129 



?K)die« have to attract the ignited bases which they have lost 

 either by fermentation, friction, or simple contact. I am glad 

 therefore that I had delayed putting the finishing hand to the 

 account of my experiments, because the theory of the Leyden 

 phial by the action of a single fluid l.'ecomes thereby much sini- 

 p!er, as well as many otlier facts. I think I shall he able by the 

 end of October to send a full account of my principal experi- 

 ments. In llie mean time I shall describe the way in which I 

 arrange a non-insulated apparatus. 



I .place a v. ine bottle or flask on an insulator having two stalks 

 and kncbs bent inward, to charge on one hand the interior coat- 

 ing, and on the other to detonate on the knob of a third stalk 

 screwed into the metallic stand of the insulator. Instead of 

 placing there a tube with metal wires and water, place in con- 

 tact a copper rod to which a chain is to be fixed to draw away 

 the fluid on a laminated plate of lead tv.'o or three feet long. 

 At the end of this plate fix with wax a large copper knob as 

 high as the rod of a Leyden jar, of the same size with the first, 

 in such a way that its knob may present itself facing that of the 

 roil of lead. We begin by searcliiug for the distance, in order 

 to obtain the strongest detonations iiom that which commuri- 

 cates with the first conductor: afterwards, haviiig attached with 

 soft wax a gold or silver wire to the metal of the rubber, iii order 

 to fix in the same way the other end against the exterior coathig 

 of the second bottle ; we leave a separation of about a line be- 

 tween the interior knob and that of the roll of lead This ar- 

 rangement establishes the circle, which I obtained by my two 

 hands. 



If we turn the disk or the non-insulated cylinder of a com- 

 mon apparatus with a supporter and a vv-oodcn table, on which 

 the roll of lead is placed, the fluid which we shall see incessantly 

 passing along the chain will not pass to the floor, but will pro- 

 ceed by aflfinity or elective attraction by the metallic circle, al- 

 though the latter is interrupted in the first place by the space 

 between the two copper knoljs, and afterwards by the thickness of 

 the glass of the second coated botlle. This passage charges it 

 witli suflicient strength to exhibit the spark set out by an ex- 

 citer, and to gi\c tlic commodon to make it be felt with force. 

 It appears to me, that this experiment is one of the best adapted 

 /or demonstrating the elective allinities. There is at every jet 

 a stronger .spark between the two knobs ; but it apjiears to ine 

 worthy of remark, that after a feeljle charge, the attractive force 

 can no longer o\ercome tlie lesistance which the glass of this 

 bottle opposes to the current by the gold or silver wire, and that 

 it takes its ordinary course by the wood of the table, and that 

 which supports the disk. I'loni that instant not the least fluid 



Vol. 4«. No. 220. Aii>i7iit 181G. I is 



