EXPERIMENTS. N OTHING tends to imprint chemical facts upon the mind so much as the exhibition of interesting Experiments. With this view the following Selection has been made, in which such experiments as may be performed with ease and safety, have uniformly been preferred. No. 1. Take a small phial about half full of cold water; grasp it gently in the left hand, and from another phial pour a little sulphuric acid very gradually into the water. A strong SENSATION OF HEAT will immediately be perceived. This, by the continued addition of the acid, may be increased to many degrees beyond that of boiling water. See pages 73 and 84. 2. Take a small phial, in one hand, containing some pulverized muriate of ammonia; pour a little water upon it, and shake the mixture. In this instance a SENSATION OF COLD will immediately be felt. See page 76. 3. Into a tea-cup, placed upon a hearth, and containing about a table spoonful of oil of turpentine, pour about half the quantity of strong nitrous acid, previously mixed with a few drops of sulphuric acid. The moment the acids come in contact with the turpentine, FLAME will be produced. In performing this experiment it is advisable to mix the acids in a phial, to tie the phial to the end of a stick, and at arm's length, to pour its contents into the oil; as the sudden combustion sometimes occasions a part of the liquids to be thrown out of the vessel. See note, page 74. 4. Put about an ounce of marble grossly pulverized into an eight-ounce phial, with about an equal quantity of water. Pour upon it a little sulphuric acid, and CARBONIC ACID GAS will be evolved.* See page 284. 5. Put about an ounce of iron filings into a phial with about three or four ounces of water; pour a little sulphuric acid upon the contents, and HYDROGEN GAS will be evolved. See notes, page 104. 6. Pour water into a small glass retort so as to occupy about one third of its capacity, lute its beak into the end of a gun barrel, the middle of which must be kept red-hot in a furnace, or by a chaffing-dish; then if a lamp be applied to the retort so as to cause the water to boil, the steam will pass through the red-hot iron tube, and in this case also will be decomposed; for, as the oxygen combines with the iron, the HYDROGEN GAS will be liberated, and may be collected in the usual way. See page 101. 7. Put some sulphuret of iron into a phial, pour a little diluted sulphuric acid over it, and attach a bladder, prepared as directed for experiment No. 4, to the phial. SULPHURETTED HYDROGEN, a gas extremely fetid and disagreeable, will immediately be evolved; though the ingredients here employed were destitute of smell. See page 253. 8. Put an ounce or two of the black oxide of manganese into a small glass retort, pour a little concentrated sulphuric acid upon it, and apply the heat of a lamp. OXYGEN GAS will be disengaged in abundance. See Additional Notes, No. 7. 9. Into a small glass retort put a mixture of two parts of quicklime, and one of muriate of ammonia, both in powder. Apply the heat of a lamp, and AMMONIACAL GAS will come over. See page 164. *The cheapest receiver for the collection of this and other gases is a moistened bladder, with a piece of tobacco pipe-firmly tied into its neck, and twisted in such a manner as to expel all the common air. This may easily be adapted to any vessel by means of the pipe, which may be fixed in the cork, and closely luted in the usual way. |