Heat a bit of wood in a small test-tube and light the gas that is evolved. Note the charcoal left.
Cover a piece of wood with sand or earth; heat, and note that charcoal is formed. This illustrates the old method of charcoal-burning. This subject is closely related to industrial geography.
HYDROGEN
A convenient way to prepare hydrogen is to use zinc and hydrochloric acid with a test-tube for a generator. (Consult any Chemistry text-book.) Make the gas and burn it at the end of a tube, holding a dry, cold tumbler inverted over the flame. Note that water is formed. Conclude what water consists of, namely, oxygen and hydrogen. Water may be decomposed into oxygen and hydrogen, hence a use of hydrogen may be shown by attaching a clay pipe to the generator and filling soap bubbles with the gas. When freed these rise quickly.
MAGNETS
If bar magnets cannot be obtained, use a child's horse-shoe magnet.
Procure small pieces of cork, wood, iron, brass, glass, lead, etc., and let pupils discover which the magnet attracts.
Have pupils interpose paper, wood, slate, glass, iron, lead, etc., in sheets between the magnet and the iron and note the effect on the force exerted.
Note that when one end of a magnet touches or comes near the end of a nail, the nail becomes a magnet, but not a permanent one.
Magnetize a needle by drawing one of the poles of the magnet from end to end of the needle, always in the same direction, about twenty times. Suspend the needle horizontally with a piece of silk thread and note its position when at rest.