EXTINGUISHING FIRES. 49 



been the case had they had the presence of mind to lie down and 

 roll over trying to extinguish the flame. 



Expt. 41. To Extinguish Burning Spirit or Ether. Get a 

 small saucepan and warm it slightly and then pour into it a tea- 

 spoonful of strong alcohol or methylated spirit, or, better still, of 

 ether : the warmth of the pan will quickly vaporise the ether or 

 spirit, so that by applying a light to the mouth of the saucepan 

 a large flame will be produced. Put the flaming pan on a table 

 where there is nothing near that can be set on fire, and then 

 quickly put over the pan a wet towel or piece of blanket ; the 

 flame will be extinguished just as a candle is when an extinguisher 

 is dropped over it. Precisely the same result will be produced if 

 a little strong spirit be spilt over a brick or stone floor and set on 

 fire and a wet blanket cautiously dropped over the flame. 



Experiments of this sort must on no account be tried in an 

 ordinary room with a wooden floor ', as the burning spirit is liable 

 to run down under the boards through the crevices. Builders often 

 leave shavings lying about under the flooring when putting up 

 houses, and should such shavings be set on fire by the burning 

 spirit much damage may be done. Even in cases where there is 

 fire under the floor, however, it may often be extinguished by 

 covering up the spots where smoke issues from the crevices and 

 pouring water on the floor so as to smother the fire and at the 

 same time quench it with water. 



One of the most effective appliances for extinguishing small 

 fires is an ordinary siphon of soda water or lemonade, the valve 

 being opened so as to squirt the effervescing fluid on the flaming 

 object. Here it is not only the water which acts as a quenching 

 agent, but also the gas used as aerating material ; this keeps the 

 ordinary air away from the burning matter, and thus tends to put out 

 the flame just as a wet blanket would do. The fire extinguishing 

 appliances termed "extincteurs" work on much the same principle ; 

 they contain water and certain chemicals set in action by striking 

 a knob on the machine ; these chemicals generate a quantity of gas 

 which forces out the water in a jet and also acts like the gas of 

 the soda-water siphon, keeping off air from the flames. " Hand 

 grenades " for extinguishing fires are glass bottles filled with water 

 containing dissolved therein some saline matter which tends to 

 prevent substances burning readily when the solution is sprinkled 

 over them ; so that at the very commencement of a fire, if one or 

 more of these bottles are broken in the flames, the water and saline 

 matter jointly tend to put out the fire, or at least to prevent it 

 spreading. 



Expt. 42. To render Muslin Incombustible. This property 



