The Portland daily press., 1890-05-31
OUR BOYS.
careIn Experlmentin @.

Popular Science News.l
There comes time in the life of many boys
when a passion for performing chemical ex-
periments develops itself; and If there is no
convenient out building to serve the purpose
of a laboratory, the lives of the other men,
bers of the family are rendered miserable by
nauseous and suffocating odors, and appre-
tensions Of dangerous explosions which are
not infrequently realized.
The study of chemistry is a most fasci-
mating and delightful one; but it must be
remembered that at the very beginning we
have to deal with powerful substances,
which require to be handled with great care,
or the most unpleasant consequences may
ensue. Many elementary textbooks OF
chemistry are, we think, seriously at fault
in not giving more attention to the pre-
cautions necessary in the experiments which
they describe Under the supervision of q
competent instructor, the young student is
taught how to take these precautions: but
in large class of pupils, personal attention
cannot be given to every one; and II the enter
prislDg amateur attempts to repeat the expert
ments which succeed so well under the mani
BILE that some little point will be overlooked
which may involve the entire difference
between danger and safety.
Perhaps the most common of all expert
ments is the making of hyd sc gas; this
is usually done by placing pieces of zinc in
glass flask fitted with cork and delivery
tube, and pouring in dilute sulphuric acid.
The hydrogen escapes from the end OF the
delivery tube, where it is ignited. This is
apparently simple enough; but the beginner
and air mixed together form very explosive
mixture, and attempts to Ignite the hydro
gen before it has entirely displaced the air
in the flask. A violent explosion ensues,
throwing the acid and fragments of glass
in all directions, not infrequentlY causing
college. was terribly injured BY the
explosion of glass flask in which be was
preparing carbonic-acid gas; the delivery
tube being DISTRACTED, and the pressure Of
the confined gas causing an explosion
An experiment frequently given in text
books is to rub few grains of chlorate of
potash and sulphur together in mortar,
when slight explosions will occur, Unless
very small quantities are used in this eXper
iment, the explosion is likely to be any thing
but slight" but this point Is rarely noticed
with sufficient emphasis: we know Of
Improve" upon this experiment, by substi-
tuting phosphorus for sulphur. The mixture
was made up into "torpedoes," and placed
in his pocket for safe keeping By good
luck, the explosion which resulted did no
serious injury; but the consequence might
A recent number of leading educational
journal suggests, as an experiment to Illus
trate the expansive power of steam, the ex
plOsion of "candle-bOmbs; i.e., small glass
bulbs containing water, and Theoretically
sealed. From personal experience with a
home made candle-bomb, we think we
should prefer to fire gun in a room filed
with scholars, rather than attempt to ex-
plode one of these miniature internal ma
chimes but nothing was said in the journal
above mentioned to indicate that the exper
iment was accompanied blythe slightest dan
ger.
a number Of experimeI ) with phospho-
HIS rare. rsVelrlv JfflIiant aud beautiful but
phosphorus is a substance which should
never be handled by inexperienced persons
1t is a treacherous and dangerous element
at the best.
We could give many more examples SINH
lar to the above, but enough has been said
to show that the beginners in chemistry
should confne himself to experiments that
are free from all possibility of danger, un-
less he has some experienced friend or teach
er to warn him against unforeseen emergen-
cies. OF course, to obtain any complete
knowledge of the science one must handle
both explosive and poisonous substances;
but the probable danger must always be
borne in mind, and if no personal instruc-
ton can be obtained, the risk should be re-
duced to minimum by working with the
smallest possible quantities.