lead. Fill a decanter with pure water; suspend the bar in it
easily by means of a fine brass wire running through the centre of
the cork; pour in the sugar of lead, and cork tightly. Let it
stand without being moved, and watch the formations.

Our boy took a quart glass fruit jar, and bought a cork to fit it
for a few cents. He could not get a solid bar of zinc, but had a
piece of zinc folded which answered the purpose. Then following
the rest of the directions, he placed the jar on the mantel-piece.
The next day; the formations began, and are constantly changing.

L. E. K.

* * * * *

I send some simple experiments for the chemists' club. Put into a
small chemist's mortar as much finely powdered potassium chlorate
as will lie upon the point of a penknife blade, and half the
quantity of sulphur; cover the mortar with a piece of paper having
a hole cut in it large enough for the handle of the pestle to pass
through. When the two substances are well mixed, grind heavily
with the pestle, when rapid detonations will ensue; or after the
powder is mixed, you can wrap it with paper into a hard pellet,
and explode it on an anvil with a sharp blow of a hammer.

To make iodide of nitrogen, cover a few scales of iodine with
strong aqua-ammonia. After it has stood for half an hour, pour off
the liquid, and place the brown precipitate, or sediment, in small
portions on bits of broken earthenware to dry. When perfectly dry,
the particles may be exploded with the touch of a rod, or even of
a feather.

I would like to exchange crystallized quartz or gold ore for zinc
or silver ore.

JOHN R. GLEN,
Nacoochee, White County, Georgia.

We would advise our young chemists to buy some good work on the elements
of chemistry, and study it well before they undertake any experiments,
as handling reagents, when one is not aware of their true composition
and behavior under all conditions, is a very dangerous pastime, by which
absolutely nothing can be learned, and a great deal of mischief done to
face, eyes, hands, and clothing, to say nothing of mamma's table-cloths
and carpets.

* * * * *

NEWPORT, RHODE ISLAND.

I thought I would write to the Post-office Box about my white
mice. At one time I had fourteen, and they did many funny