104 ON THE EXPLOSIBILITY OP COAL OILS. 



blaze with a slight flame above the open orifice. Indeed with the sample 

 of oil which did not emit sufficient gaseous vapour to become kindled at 

 a temperature below 125 deg., it required dexterous manipulation to so 

 apportion the gaseous vapour and the atmospheric air as to exhibit the 

 faintest action of an explosive character. 



Continuing the experiment with the kerosene at a still higher tem- 

 perature than 212 deg., by pouring it into an iron ladle over a hot fire, 

 the gaseous vapour arose therefrom still more rapidly, until it became 

 a visible smoke ascending regularly in a column from the ladle even 

 whilst heated red-hot, without becoming kindled into flame until a 

 lighted taper was brought into contact with it ; then the gaseous vapours 

 became resolved into a bright column of steady flame without any 

 evidence of an explosive tendency. 



Whale oil, tallow, rosin, and pine sawdust were similarly exposed 

 in the same heated ladle with precisely similar results, showing that the 

 kerosene was no more explosive than either of these substances, and 

 that they all alike became decomposed at a high temperature, into their 

 constituent elements of carbon and hydrogen, or carburetted hydrogen 

 gas. One measure of this inflammable gas is found to form a new 

 chemical combination with about three measures of atmospheric air 

 when kindled, and to exhibit the phenomenon of an elongated flame 

 whilst the combination is taking place between the ascending particles 

 of the surface of the gas and the particles of air in immediate contact 

 therewith. This result is manifested in the form of the flame of a 

 lamp or gas-burner. But if one measure of carburetted hydrogen be 

 thoroughly mixed with four or five of atmospheric air, so that the 

 particles be all brought into intimate contact with each other, then the 

 combination takes place simultaneously throughout, producing the 

 sudden and violent expansive action denominated an " explosion." 

 In order, therefore, to produce an explosion of a lamp or of any other 

 vessel, it is only necessary to mix the gases of decomposed oil, coal, 

 or wood with this combining portion of atmospheric air, and then to 

 apply a lighted match to the mixture. 



Dangerous explosions are thus often produced in common stoves on 

 suddenly decomposing the wood, shavings, or paper used therein for 

 kindling, by throwing red hot coals upon them. The carburetted 

 hydrogen, rising in the form of a dense smoke, becomes commingled 

 with the atmospheric air occup\dng the chamber of the stove, and on 

 being kindled the whole simultaneously flashes into flame. In " air- 

 tight stoves" these explosions have often proved destructively violent 

 to persons and property. 



Thus there may ensue dangerous explosions even in lighting a fire 

 in a stove ; and most fearful explosions have often taken plaoe in 

 apartments of dwelling-houses, when about one-fifth part of the space 

 therein becomes occupied by coal gas escaping from leakages of gas- 

 pipes. The difference in the extent of the violence in such cases is 



