CONVERSION OF FLUIDS INTO THE GAZEOUS STATE. QS

The water during boiling becomes converted into vapour, thisvapour expels the air of the vessel and occupies its place; ondiminishing the heat, it condenses ; when the retort is stopped, apartial vacuum is formed; the pressure becomes diminished, anda less degree of heat is sufficient to cause an ebullition.

For the same reason water may be made to boil under the ex-hausted receiver at 94° Fahr. or even at a much lower degree ;alcohol at 56°, and ether at — 20°.

On the conversion of fluids into gases is founded the. followingexperiment:

Experiment III.

To freeze water ly means of sulphuric ether.

Take a thin glass tube 4 or 5 inches long and about two orthree eighths of an inch in diameter, and a two ounce bottle fur-nished with a capillary tube fitted to its neck. In order to makeice, pour a little water into the tube, taking care not to wet theoutside, nor to leave it moist. Having done this, let a stream ofsulphuric ether fall through the capillary tube upon that part ofit containing the water, which by this means will be convertedinto ice in a few minutes, and this it will do even near a fire otin the midst of summer.

If the glass tube containing die water be exposed to the briskthorough air, or free draught of an open window, a large quan-tity of water may be frozen in a shorter time; and if a thin spiralwire be introduced previous to the congelation of the water, theice will adhere to it, and may thus be drawn out conveniendy.

A person might be easily frozen to death during very warmweather, by merely pouring upon his body for some time sul-phuric edier, and keeping him exposed to a thorough draughtof air.