ON THE ELECTRIC COLUMN. i y 4 



observations, which principally relates to the electric state oF 

 the ground. This state is here compared with that of thie 

 extremities of the column^ which I have called negative-^ 

 though it is sometimes neutral comparatively with the elec- 

 tric state of the ambient air; but it is never positive; On 

 the other haiidj the bead never moves but as positive com- 

 paratively with the same standard, and it moves the faster; 

 3s the bail 18 differs more from its electric state. Now it is 

 seen in the above observations, that sometimes the bead 

 moves faster when the ball is in communication with the 

 ground, than when it communicatees with thfe extrertiity of 

 the column called negative. This is a test of the electric 

 State of the ground whicn deserves to be deeply studied, in 

 order to understand it better. 



Were I younger, I ought not to publish these eXpevimientS 

 and obsiervations in their present state ; I should endeavour 

 fit-st, to improve the instrument, in order to meet with mor* 

 advantage a proper season ; then to follow the motion of the 

 aerial electroscope more regularly than hitherto I have been 

 able to do, being constantly employed in improving it; and 

 to study the connexion between these motions and the 

 changes in the electric state of the air near the ground, and Electric staU 

 of the ground itself: a course of observations, which is to be of the ground 

 followed from the time of the greatest effects of the column, connected 

 to that of their rapid diminution, coinciding with the time with vegcta- 

 when vegetation, the greatest terrestrial phenomenon, pre- 

 vails on all the ground, and in which it thus appears, that 

 the electric Jiuid h'as some influcmce. But though it is pos- 

 sible, that I may take up again these observations, I prefer , 

 an earlier communication to natural philosophisrs of tJ-.e be- 

 ginning of researches of this class ; because at any rate these 

 researches would advance morc-certainly, should they be- 

 come the object of many observers, not merely for assembling 

 scattered and unconnected phenomena, bat for considering 

 the light that they reflect upon each Other, which may help 

 to trace up their real causes. No spontaneous effects can 

 manifest in a more characteristic manner these remote con- 

 nexions between terrestrial phenomena by common cpusesy 

 than those offered to our view by the atmosphere, in which 

 therefore we muet endeavour to extend our knowledge by 



meteorological 



