314 
15LECTRIC COLUMN. 
the disks were in the position above described j but the balls 
could be brought, by a silk thread, to meet together ; and then 
the positive disk, by a spark, was reduced to the same electrical 
state as the other. If, therefore, the same quantity of electric 
fluid remained in the disks afier the last operation, the positive 
compensating the defficiency of the negative, both electrometers 
would have been reduced to zero of their scale ; or the electric 
state of the ground ; but it was not so, both disks were 
negative of many degrees, as shewn by the electrometers. 
Being thus informed, that when the electric fluid emits light in 
sparks, a part of it is decomposed, we are certain that light 
enters into its composition. 
These facts, aided by the discoveries which almost daily 
increase in experimental philosophy, may, in time, lead to some 
explanation of the new phenomenon which is here my princi- 
pal object j that of the increase of power produced in the 
electric column by the sun’s rays falling upon it j since I have 
proved above, that this increase of power can only be attribut* 
ed to the formation of new quantity of electric fluid in the 
column itself j which quantity is soon distributed, through the 
air, to the surrounding bodies, when no more is produced in it 
by the sun’s retreat. But this being an essential phenomenon, 
which would not readily be admitted by experimental philoso- 
phers, if ascertained by only one observer, I shall adduce some 
observations even more striking than mine, made afterward by 
another experimental philosopher. 
Other facts by You have mentioned. Sir, in the same number of your 
res^pwting*toe 3^ Hanoverian gentleman, Mr. Haussmann, but only 
increase of on account of his having undertaken the construction of my 
dcctricitv bv 
tfie solar hygrometer, and published very useful hygroscopic tables, 
flsht. But as bis attention had been engaged by this instrument from 
its importance in meteorology, be wanted to study at the same 
time the phenomena of the electric column, and by degrees be 
has constructed one much more powerful than mine, being com- 
posed of 10,000 pairs of plates, inch square; and he has so 
settled the parts of that column on an insulating board, that the 
fpparatusmay be transported, without any disturbance, wbere- 
ever 
