340 EXPLOSIBILITY OF COAL OILS. 



first shattered by explosions of the naphtha vapor and then burned 

 down. 



Petroleum contains a considerable percentage of naptha, and con- 

 sequently partakes in a degree of its dangerous properties. There 

 appears to be sufficient reason for classing these liquids as specially 

 hazardous. 



In making experiments with the tin vessel of the capacity of a 

 common lamp, (before described,) a single drop of naphtha was found 

 to yield sufficient vapor to produce as much explosive action as could 

 be produced by the most inflammable coal oil for sale in the market, 

 when similarly experimented with ; and after every experiment failed 

 to exhibit the slightest explosive tendency of the best kerosene oil, 

 a single drop mingled therewith rarely failed to yield sufficient vapor 

 to manifest its presence by a slight explosive puff when kindled by a 

 lighted match. The combustion in this case was confined to the 

 minute quantity of naphtha gas, without either kindling the kerosene 

 oil, or dangerous results. 



In all the accounts of the explosions of camphene and burning-fluid 

 lamps there appears to be no statements of any damage or injury to 

 life or property by the mere mechanical force developed. The prin- 

 cipal disastrous results are caused by the scattering about of highly 

 inflammable liquids, which instantaneously spread the conflagration 

 over surrounding combustible substances. It is sufficient to produce 

 the most disastrous consequences, if a lamp containing any of these 

 highly inflammable liquids produce only a sufficient gust of an ex- 

 plosive character to disperse the blazing contents over the dresses of 

 adjacent persons or surrounding combustible matter. The rapid 

 communication of the flames has in this way often proved fatal to life 

 and destructive to buildings. For this reason the rates of premium 

 for fire insurance have been enhanced on property jeopardized by the 

 use of camphene and burning fluid in lamps for lighting factory build- 

 ings. As the accidental fall and breakage of camphene or burning- 

 fluid lamps on a floor have often produced the loss of life and property 

 by communicating fire, as above stated, an experiment was made to 

 test the comparative results which might be anticipated from a simi- 

 lar accident to a burning lamp containing coal oil, which required to 

 be heated to 125° before it emitted sufficient gaseous vapor to be 

 kindled by a lighted match. Some coal oil of this quality was poured 

 out of a burning lamp upon a floor and the blazing wick dropped 

 therein. There it continued burning until the heat of it raised the 

 temperature of the surrounding coal oil to 125°, when the blaze be- 

 gan gradually to spread over the surface of the oil on the floor in an 

 enlarging circle, but no sudden flash of flame spread over the whole 

 surface at once, as was the case when burning-fluid and camphene 

 were similarly experimented upon. 



To represent the effect of accidentally spilling the kerosene oil from 

 a burning lamp upon a cotton dress, a piece of calico cloth was moist- 

 ened with the oil, and then held up in contact with the flame of a 

 lamp. The kerosene required a little time for its temperature to 

 become raised to the evaporative point of 125°, before the blaze 



