Part 12 (1/2)
It is thus with animals of every kind; even minute microscopical insects cannot live without air.
_Experiments with Sparrows._
Count Morozzo placed successively several full-grown sparrows under a gla.s.s receiver, inverted over water. It was filled with atmospheric air, and afterwards with vital air. He found,
First.--That in _atmospheric_ air, HOURS MIN.
The first sparrow lived 3 0 The second sparrow lived 0 3 The third sparrow lived 0 1
The water rose in the vessels eight lines during the life of the first; four during the life of the second; and the third produced no absorption.
Second.--In _vital_ air or _oxygen_, HOURS MIN.
The first sparrow lived 5 23 The second 2 10 The third 1 30 The fourth 1 10 The fifth 0 30 The sixth 0 47 The seventh 0 27 The eighth 0 30 The ninth 0 22 The tenth 0 21
The above experiments elicit the following conclusions:--1. That an animal will live longer in vital than in atmospheric air.--2. That one animal can live in air, in which another has died.--3. That, independently of air, some respect must be had to the const.i.tution of the animal; for the sixth lived 47 minutes, the fifth only thirty.--4.
That there is either an absorption of air, or the production of a new kind of air, which is absorbed by the water as it rises.
AMUSING EXPERIMENTS IN ELECTRICITY.
_The Animated Feather._
Electrify a smooth gla.s.s tube with a rubber, and hold a small feather at a short distance from it. The feather will instantly fly to the tube, and adhere to it for a short time; it will then fly off, and the tube can never be brought close to the feather till it has touched the side of the room, or some other body that communicates with the ground. If, therefore, you take care to keep the tube between the feather and the side of the room, you may drive it round to all parts of the room without touching it; and, what is very remarkable, the same side of the feather will be constantly opposite the tube.
While the feather is flying before the smooth tube, it will be immediately attracted by an excited rough tube or a stick of wax, and fly continually from one tube to the other, till the electricity of both is discharged.
_The Candle lighted by Electricity._
Charge a small coated phial, whose k.n.o.b is bent outwards so as to hang a little over the body of the phial; then wrap some loose cotton over the extremity of a long bra.s.s pin or wire, so as to stick moderately fast to its substance. Next roll this extremity of the pin, which is wrapped up in cotton, in some fine powdered resin; then apply the extremity of the pin or wire to the external coating of the charged phial, and bring, as quickly as possible, the other extremity, that is wrapped round with cotton, to the k.n.o.b; the powdered resin takes fire, and communicates its flame to the cotton, and both together burn long enough to light a candle. Dipping the cotton in oil of turpentine will do as well, if you use a larger sized jar.
_Candle Bombs._
Procure some small gla.s.s bubbles, having a neck about an inch long, with very slender bores, by means of which a small quant.i.ty of water is to be introduced into them, and the orifice afterwards closed up.
This stalk being put through the wick of a burning candle, the flame boils the water into a steam, and the gla.s.s is broken with a loud explosion.
_The Artificial Spider._
Cut a piece of burnt cork, about the size of a pea, into the shape of a spider; make its legs of linen thread, and put a grain or two of lead in it to give it more weight. Suspend it by a fine line of silk between an electrified arch and an excited stick of wax; and it will jump continually from one body to the other, moving its legs at the same time, as if animated, to the great surprise of the unconscious spectator.
_The Miraculous Portrait._
Get a large print (suppose of the king) with a frame and gla.s.s. Cut the print out at about two inches from the frame all round; then with thin paste fix the border that is left on the inside of the gla.s.s, pressing it smooth and close; fill up the vacancy, by covering the gla.s.s well with leaf-gold or thin tin-foil, so that it may lie close.
Cover likewise the inner edge of the bottom part of the back of the frame with the same tin-foil, and make a communication between that and the tin-foil in the middle of the gla.s.s; then put in the board, and that side is finished. Next turn up the gla.s.s, and cover the fore-side with tin-foil, exactly over that on the back part; and when it is dry, paste over it the panel of the print that was cut out, observing to bring the corresponding parts of the border and panel together, so that the picture will appear as at first, only part of it behind the gla.s.s, and part before. Lastly, hold the print horizontally by the top, and place a little moveable gilt crown on the king's head.