APl'EftDIX.

151

combination of oxygene and hydrogene, may dependupon this peculiar electrical property; and why foil ofplatinum should have its power of causing oxygeneand hydrogene to combine, increased by being placed*for a short time, in nitric acid, as MM. Dulong andThenard have shewn, may be owing to this, that theslight positive charge it acquires may, in being broughtinto equilibrium, be a first step in the operation; andthere are analogous instances.

Fine wire of platinum, I find, when conveying cur-rents of Electricity, as in a circuit, with zinc and sulphu-ric acid, or charcoal and nitromuriatic acid, has not itspower of acting upon gaseous mixtures sensibly in-creased.

No. 3.

The general inflammable air is only disengaged incoal mines ; yet the salt works of Styria, Salzburg, andUpper Austria are not exempt from accidents depend-ing upon carbonated hydrogene gas. An explosion hadhappened at Aussee, in 1818, a few weeks before Ivisited the salt works, by which several persons werekilled ; and the miners received the Safety Lamp, andwitnessed its operation with gratitude and surprise.

The inflammable air appeared to me, in these instances,to be derived from bituminous shist.