TO FREEZE WATER WITH ETHER.
Fill a very thin glass tube with water. Close it at one end, and wrap muslin round it: then frequently immerse the tube in strong ether, allowing what the muslin soaks each time to evaporate, and in a short time the water will be frozen.
PRODUCTION OF NITRE.
Dip into the above solution a piece of paper: if its colour be changed to brown, a drop or two more acid must be cautiously applied: if, on the contrary, it reddens litmus paper, a small globule or two of potassium will be required; the object being to obtain a neutral solution: if it then be carefully evaporated to about half its bulk, and set aside, beautiful crystals will begin to form, which will be those of the nitrate of potash, commonly called nitre, or saltpetre.
CURIOUS TRANSPOSITION.
Take a glass of jelly, and place it mouth downward, just under the surface of warm water in a basin: the jelly will soon be dissolved by the heat, and, being heavier than the water, it will sink, while the glass will be filled with water in its stead.
ANIMAL BAROMETER.
Keep one or two leeches in a glass bottle nearly filled with water; tie the mouth over the coarse linen, and change the water every two or three days. The leech may then serve for a barometer, as it will invariably ascend or descend in the water as the weather changes from dry to wet; and it will generally come to the surface prior to a thunder-storm.
MAGIC SOAP.
Pour into a phial a small quantity of oil, with the same of water, and, however violently you shake them, they cannot be mixed, for the water and oil have no affinity for each other; but, if a little ammonia be added, and the phial be then shaken, the whole will be mixed into a liquid soap.