HEAT OK CALORIC. 



A 



ADDITIONAL EXPERIMENTAL ILLUSTRATIONS OF THE NATURE OF 

 AERIFORM BODIES. 



1. Aeriform bodies can displace gross fluids or pre- 

 vent their entrance into cavities which they occupy. 

 The figure represents a cylindrical glass containing a 

 colored fluid, upon which is a taper floating upon a 

 wide, flat and thin cork ; a narrow and tall bell glass 

 is placed carefully over the light, and depressed as far 

 as it can be, without making the fluid overflow ; the 

 light is then seen at b b which is the surface of the 

 fluid, within the jar, while a a, shows its position on the 

 outside. It is hardly necessary to mention that this is 

 the principle of the diving bell. 



2. The candle bomb is a spherule of glass contain- 

 ing a little alcohol, ether or water ; it has a stem, which 

 is stuck into a candle, so that the ball shall be in, or 

 just above the wick, which is touched with oil of tur- 

 pentine, that it may be lighted promptly ; when this is done, the fluid 

 is vaporized, and the glass soon explodes ; it should be placed behind 

 a screen. 



3. A glass flask containing water over an Jlrgand or spirit lamp. 

 or over a few burning coals, shews the phenomena of boiling. 



4. The Eolipile. A copper ball with a recurved tube, shews the 

 force of steam, issuing from a capillary orifice ; it will vigorously 

 blow a burning brand, or the entire fire, if placed on the hearth. If 

 ether, or alcohol, or oil of turpentine be substituted for the water, the 

 jet of vapor is then inflammable. The fluid is introduced as it is 

 into the thermometer ball. 



5. Ether is easily vaporized. 



(a.) In a flaccid bladder, furnished with a stop cock and tube, let 

 a little ether be heated by contact with hot water ; it will soon in- 

 flate the bladder, which being compressed, will give a jet of inflam- 

 mable vapor ; or cold water applied to the bladder will condense it. 



(b.) A tall thin glass jar, filled with water, and standing in the pneu- 

 matic cistern, has a little ether introduced, by turning up beneath it, a 

 vial filled with that fluid : the jar should be 

 secured by recurved tongs, of this form, 

 or by a ring on a stand : boiling hot water, 

 from a tea kettle, being poured on the top 

 of the jar, the ether boils, and drives the water out ; if the jar be 

 quickly lifted out of the water, the etherial vapor 'may be inflamed 

 by a candle, or if allowed to stand, the water will condense the vapor 

 and will again fill the jar, except a small space occupied by extract- 

 ed air. 



