418 Experiments on the variable Action of the Electric Colunin. 
I have by means of a long wire insulated on Mr. Singer’s plan, 
when a copious dew was falling, collected pungent sparks when 
the height of the wire did not exceed five feet above the surface 
of the earth in any part of it. Hence it is concluded, that we 
cannot measure the electricity of the higher strata of the atmo- 
sphere until that of the lower, which may be excited by the eva- 
poration or condensation of moisture, or by position, has been 
first measured. Now, if this electricity of the lower strata could 
be proved to exist in a very small degree in closer situations, 
there would be no reason why it should not influence the column. 
Mr. Read has in my opinion done much towards this, by the 
aid of the doubler. 
The signs which the doubler produced were certainly strongly 
analogous to those of his rod, and there are several other ex- 
periments which appear to me to prove that what is called the 
Adhesive Electricity of such-like instruments is occasionally no 
other than that of the ambient air, which their peculiar structure 
is caleulated to collect and display. 
P. S.—Since writing the above, I have shown the tables to 
Mr. Singer, and was glad to find that he not only coincided in 
the conclusions drawn from them, but also in the idea that the 
electric state of the ambient air may be sufficiently powerful to 
influence the column: but I wished to ascertain the effeet of heat. 
upon a column not inclosed in a tube, as it might be objected, 
that the air immediately in contact with the pile I used, and the. 
inner surface, was not dried by the acid, although the hygrome- _ 
tric equilibrium might have been varied by heat. I therefore 
borrowed from Mr. Singer a pile consisting of 800 groups of 
zinc, silver, and paper supported between three pillars of glass 
covered with sealing-wax, and placed it in a very large receiver, 
together with an hygrometer, thermometer, and electrometer : 
the receiver was now placed over mercury. 
The divergence of the gold-leaves was estimated as nearly as 
T could guess by the.eye, and the following results were obtained 
Time. Hygrom. Therm. Electrom. 
June 2d. 11 40 A.M. 45 564 divergence 1:5 inch 
3.0 — 42 76£ struck 3 times per mimute 
10 0 — 45 64 ‘1-2 — per minute 
June 8d. 1 0 P.M. 44 58 divergence 1-5 inch 
Receiver taken off, 
3.30 — 464 58 idem 
3 37 receiver replaced and acid introduced 
437 — 3821 591 idem 
6 0 — 294 591 idem 
6 30.acid removed and potash substituted 
8 0 — 36 59. idem 
*s 
June 
