the mixed gases proceeding from the slow combustion of tallow and other
oily substances will produce dangerous symptoms. Dr. Blackadder remarked
in the course of his experiments on flame, that the vapour into which
oil is resolved, previous to its forming flame round the wick, excites
in minute quantities intense headache.[2088] The emanations from the
burning snuff of a candle, which are probably of the same nature, seem
to be very poisonous. An instance indeed has been recorded in which they
proved fatal. A party of iron-smiths, who were carousing on a festival
day at Leipzig, amused themselves with plaguing a boy, who was asleep in
a corner of the room, by holding under his nose the smoke of a candle
just extinguished. At first he was roused a little each time. But when
the amusement had been continued for half an hour he began to breathe
laboriously, was then attacked with incessant epileptic convulsions, and
died on the third day.[2089]—The effects of such emanations are probably
owing to empyreumatic volatile oil, which will be presently seen to be
an active poison.