338.  The late Mr. Barry communicated a paper to the Royal Society[A] last year, so distinct in the details, that it would seem at once to prove the identity in chemical action of common and voltaic electricity; but, when examined, considerable difficulty arises in reconciling certain of the effects with the remainder.  He used two tubes, each having a wire within it passing through the closed end, as is usual for voltaic decompositions.  The tubes were filled with solution of sulphate of soda, coloured with syrup of violets, and connected by a portion of the same solution, in the ordinary manner; the wire in one tube was connected by a gilt thread with the string of an insulated electrical kite, and the wire in the other tube by a similar gilt thread with the ground.  Hydrogen soon appeared in the tube connected with the kite, and oxygen in the other, and in ten minutes the liquid in the first tube was green from the alkali evolved, and that in the other red from free acid produced.  The only indication of the strength or intensity of the atmospheric electricity is in the expression, “the usual shocks were felt on touching the string.”

  [A] Philosophical Transactions, 1831, p. 165.

339.  That the electricity in this case does not resemble that from any ordinary source of common electricity, is shown by several circumstances.  Wollaston could not effect the decomposition of water by such an arrangement, and obtain the gases in separate vessels, using common electricity; nor have any of the numerous philosophers, who have employed such an apparatus, obtained any such decomposition, either of water or of a neutral salt, by the use of the machine.  I have lately tried the large machine (290.) in full action for a quarter of an hour, during which time seven hundred revolutions were made, without producing any sensible effects, although the shocks that it would then give must have been far more powerful and numerous than could have been taken, with any chance of safety, from an electrical kite-string; and by reference to the comparison hereafter to be made (371.), it will be seen that for common electricity to have produced the effect, the quantity must have been awfully great, and apparently far more than could have been conducted to the earth by a gilt thread, and at the same time only have produced the “usual shocks.”

340.  That the electricity was apparently not analogous to voltaic electricity is evident, for the “usual shocks” only were produced, and nothing like the terrible sensation due to a voltaic battery, even when it has a tension so feeble as not to strike through the eighth of an inch of air.