Dissolve boracic acid and nitrate of baryta in spirits of wine, and supply the Bude lamp with this solution.
Sixteenth Experiment. A Yellow Light.
Dissolve common salt in spirits of wine, and burn it as already described in the Bude light apparatus.
Seventeenth Experiment. The Oxy-calcium Light.
This very convenient light is obtained in a simple manner, either by using a jet of oxygen as a blowpipe to project the flame of a spirit lamp on to a ball of lime; or common coal-gas is employed instead of the spirit lamp, being likewise urged against a ball of lime. By this plan one bag containing oxygen suffices for the production of a brilliant light, not equal, however, to the oxy-hydrogen light, which will be explained in the article on hydrogen. (Fig. 103.)
Fig. 103.
No. 1. a. Oxygen jet. b. The ball of lime, suspended by a wire. c. Spirit lamp. No. 2. d. Oxygen jet. e. Gas (jet connected with the gas-pipe in the rear by flexible pipe) projected on to ball of lime, f.
Eighteenth Experiment.
To show the weight of oxygen gas, and that it is heavier than air, the stoppers from two bottles containing it may be removed, one bottle may be left open for some time and then tested by a lighted taper, when it will still indicate the presence of the gas, whilst the other may be suddenly inverted over a little cup in which some ether, mixed with a few drops of turpentine, may be burning—the flame burns with much greater brilliancy at the moment when the oxygen comes in contact with it.