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MINUTES OF PROCEEDINGS OF 
earlier days of tlie employment of these illuminating agents there were 
so many recorded in the newspapers, and of which one still hears oc¬ 
casionally, were, with very few exceptions, not correctly designated 
as explosions, and when they were so, were not caused by the employment 
of the volatile oils or petroleum spirit. As these vaporise very freely at 
the slightly elevated temperature which a reservoir of a lamp soon 
attains, air is either entirely expelled from the latter by the vapour, or 
so diluted by it that the mixture is not explosive. If, therefore, flame 
can have access to vapour escaping from any opening in the reservoir 
near the wick, in a badly-constructed lamp, it will merely burn as it 
escapes. If a lamp charged with petroleum spirit be carried incautiously, 
or accidentally jerked so that the liquid is suddenly brought into con¬ 
tact with the warmer portion of the lamp, near the flame, a very rapid 
volatilisation may thereby be caused, resulting in a considerable outburst 
of flame. In either case, a nervous person, holding the lamp at the 
time, may drop it in alarm, or the reservoir, if of glass, may be broken 
by the sudden burst of vapour and the resulting large flame; in such 
instances, the spirit will be scattered and at once inflamed, inflicting 
injuries more or less severe on the instigator of the accident, or setting 
fire to the premises.* A so-called petroleum-lamp explosion which 
occurred, quite recently, at Gloucester, resulting in the death, from 
burns, of a woman, was evidently brought about by the cause last 
described. 
If a petroleum oil which has been imperfectly refined, and which 
therefore contains some proportion of the very volatile products, or 
spirit, be employed in a lamp, a slight explosion may be caused by its 
yielding up a small amount of vapour at the temperature to which the 
reservoir becomes heated, and thus producing a feebly explosive mixture 
with the air in the latter, which may become ignited by the flame of the 
lamp. An explosion thus produced is not at all of violent character, 
being generally merely a feeble puff; it may, however, cause the 
cracking of the reservoir, and the consequent spilling and inflaming of 
the oil, and may at any rate lead to accident as already described, by the 
alarm which it occasions to nervous or ignorant persons. 
There is no doubt whatever that a very considerable proportion of 
the accidents which occur to persons using petroleum lamps are really 
traceable to the erroneous belief, which is still so very prevalent, in the 
explosive character of these liquids. The fact that they and their vapours 
are simply inflammable, and that the latter require to be mixed with a 
* The Reports by Captain Shaw to the Metropolitan Board of Works of the causes of fires in 
London, show a generally steady increase in the number of fires caused by lamps. 'Thus, there 
were 20 in 1866, 30 in 1869, 49 in 1871, 56 in 1872, 47 in 1873, and 67 in 1874, -These returns in¬ 
clude fires from lamps of all kinds (many not defined); but it may be reasonably assumed that three- 
fourths of the totals noted were caused by petroleum-lamps. From one to seven fires annually are 
reported as caused by upsetting, “ drawing off,” or explosion of naphtha, paraffin, crystal oil, or 
petroleum. The proportion which fires from the above causes bear to fires caused by candles is 
small, but has been on the increase in the last few years. From 1866 to 1870 inclusive, the fires 
caused by candles were from seven to ten times more numerous than those caused by lamps; but 
in 1872 they were only about five times; in 1872 and 1873, four times; and in 1874 only a little 
over three times more numerous. 
