[Illustration]
Into a half-pint glass bottle, put some zinc, granulated by being
melted in a ladle, and then poured gradually into water. Add some
sulphuric acid, diluted with eight parts by weight of water. Then pass
a glass tube with a capillary bore, through a cork, which you have
previously made to closely fit the bottle, and cork the bottle well.
In a short time, the atmospheric air will be expelled, and hydrogen
gas will rise through the tube; you then apply a light, and the gas
will become ignited. If you now hold another glass tube, about eighteen
or twenty inches long over the flame sufficiently wide to enclose the
other tube very loosely (_see engraving_), the little speck of flame
will sport along the larger tube, and musical sounds will be produced,
which may be varied by using other tubes of different dimensions, and
made of different materials; the wide tubes forming the lower, and the
narrow tubes the upper notes.