Among the various instruments unpacked from the box, Monsieur Roger chose a round tube of glass, closed at one end, tapering, and open at the other end. He introduced into this tube a certain quantity of water so as to half fill it. Then he placed the tube above a little alcohol lamp, and made the water boil.
"Remark," said he, "how fully and completely the vapors from the water, which are formed by the influence of heat, force out the air which this tube encloses in escaping by the open end of the tube."
When Monsieur Roger judged that there no longer remained any air in the tube, he begged Monsieur Dalize to hand him the blowpipe. Monsieur Dalize then handed to his friend a little instrument of brass, which was composed of three parts,--a conical tube, furnished with a mouth, a hollow cylinder succeeding to the first tube, and a second tube, equally conical, but narrower, and placed at right angles with the hollow cylinder. This second tube ended in a very little opening.
Monsieur Roger placed his lips to the opening of the first tube, and blew, placing the little opening of the second tube in front of the flame of a candle, which Monsieur Dalize had just lit. A long and pointed tongue of fire extended itself from the flame of the candle. Monsieur Roger placed close to this tongue of fire the tapering and open end of the tube in which the water had finished boiling. The air, forced out of the blowpipe and thrust upon the flame of the candle, bore to this flame a considerable quantity of oxygen, which increased the combustion and produced a temperature high enough to soften and melt the open extremity of the tube, and so seal it hermetically.
"I have," said Monsieur Roger, "by the means which you have seen, expelled the air which was contained in this tube, and there remains in it only water. In a few moments we will make use of it. But it is good to have a comparison under your eyes. I therefore ask Miss Miette to take another tube similar to that which I hold."
"Lastly, I ask her to turn it over quickly, with her little hand placed against its lower side in order to prevent the water from falling upon the floor."
Miss Miette did as she was commanded. The water fell in the tube, dividing itself into drops of more or less size. It was like rain in miniature.