INVISIBLE COMBUSTION.
Pour a very little liquid ether into a half-gallon bottle, and the ether, in evaporating, will, of course, fill the bottle with its vapour. Then make a glass rod very hot, but not red-hot, and dip it for half a minute into the neck of the large bottle, and although no smoke, fire, flame, or mist is to be seen, an invisible combustion of the ether vapour does go on inside the bottle. This is proved by inserting a thermometer in the neck of the bottle, when a high temperature is very soon indicated by the instrument.