KLKCTRIC COLUMN. 
37 
V. 
On the Electric Column, By Geov.ok J*hn Singer, Z,<c- 
turer on Experimental Philosophy , iSfc. (From the Author. J 
S OON after the Invention of the electric column, 1 in- Explanation! 
stituted a series of experiments on its construction ai)^ between ihe*^ 
properties, which have been continued, at every interval of Electric Co- 
, . , . lumn, and it 
leisure, to the present tune. Pile or Volta 
The distinction between that Interesting instrument, and 
the voltaic apparatus, always appeared to me to aris« from the 
nature of the substance interposed between the different pairs 
of plates — a lujuid, whose parts have freedom of motion, beiag 
essential to the proper action of the voltaic apparatus, whilst 
that condition is unnecessary in the electric column, which re- 
quires only the combination of its pairs of metal plates by 
some conductor that does not counteract their electromotive 
power. 
The discs of paper nsually employed for this purpose owe 
their conducting faculty entirely to the water they contain, 
perfectly dry paper being a non-conductor. But this perfect 
dryness can only be obtained by exposing the papers to a heat 
nearly sufficient to scorch them, as those who endeavour to 
excite that substance by friction, will soon acknowledge. And 
the attraction of paper for that small quantity of water, which 
renders it conducting, is such, that in the ordinary state of the 
atmosphere it resumes its original conducting power in a few 
minutes after it is removed from the lire. 
The permanent action of the electric column appears to 
depend on the condition that there be no sensible change in 
the nature of the substances of which it is composed, and 
therefore, within certain limits, the drier the pieces of paper, 
the more completely will this object be accomplished, provided 
(hey still retain sufficient conducting power. I have found 
that they do so even when the column is put together under 
the full influence of the sun’s rays, and at a time when the 
beat they produce is sufficient to warp the paper discs consi- 
derably j 
