A Guide To The Scientific Knowledge Of Things Familiar - LightNovelsOnl.com
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Q. _Why do all fruits, &c. (when severed from the tree) FALL to the EARTH?_
A. Because the earth _attracts them_.
Q. _Why do persons (who water PLANTS) very_
_often pour the water into the SAUCER, and not OVER the PLANTS?_
A. Because the water in the saucer is _supped up_ by the mould (through the hole at the bottom of the flower-pot), and is transferred to the stem and leaves of the plant by CAPILLARY ATTRACTION, (_See p. 84_).
Q. _Why is vegetation on the MARGIN of a RIVER more LUXURIANT than in an open FIELD?_
A. Because the porous earth on the bank _sups up water_ to the roots of the plants by CAPILLARY ATTRACTION.
Q. _Why is a LUMP of SUGAR (left at the bottom of a cup) so LONG in MELTING?_
A. Because _as it melts_, it makes the tea above it _heavier_; and (so long as it remains at the bottom) is surrounded by tea fully _saturated_ with sugar; in consequence of which, the _same_ portions of liquid will hold _no more sugar in solution_.
Q. _Why does the LUMP of SUGAR MELT more QUICKLY when STIRRED ABOUT?_
A. Because _fresh portions of unsaturated tea_ keep coming in contact with the lump, and soon dissolve it.
Q. _Why does a PIECE OF SUGAR (held in a spoon at the TOP of our tea) melt very RAPIDLY?_
A. Because as the tea becomes _sweetened_, it _descends to the bottom of the cup_ by its own gravity; and _fresh_ portions of unsweetened tea are brought constantly into contact with the sugar, till the lump is entirely dissolved.
Q. _How can a SICK ROOM be kept FREE from unhealthy EFFLUVIA?_
A. Vinegar boiled with myrrh, or camphor, sprinkled in a sick room, will _entirely correct putridity_.
Q. _Why does LIME destroy the offensive smells of BINS, SEWERS, &c.?_
A. Because it combines with the _carbonic acid_ of these places, and converts it into CARBONATE OF LIME, which is entirely _free from smell_.
Q. _Why does CHLORIDE of LIME fumigate a sick room?_
A. Because the chlorine absorbs the _hydrogen of the stale air_; and by this means removes both the _offensive smell_ and the _infection_ of a sick room.
Q. _How can the TAINT of MEAT be removed?_
A. Either by was.h.i.+ng with PYROLIGNEOUS ACID,--covering it for a few hours with common CHARCOAL,--or by putting a _few lumps of charcoal_ into the _water in which it is boiled_.
Q. _Why do these things DESTROY the TAINT of meat?_
A. Because they _combine_ with the _putrescent particles_, and neutralize their offensive taste and smell.
Q. _Why should BED-ROOMS, COTTAGES, HOSPITALS, and STABLES, be washed occasionally with LIME-WHITE?_
A. Because the lime _is very caustic_, and removes all organic matters adhering to the walls.
Q. _How can MOULDINESS be prevented?_
A. The perfume of _any essential oil_ will prevent mouldiness from ink, paste, preserves, &c.
Alum, salt of amber, borax, nitre, salt, camphor, charcoal, and pyroligneous acid, are all excellent antiseptics.
Salt, corrosive sublimates, copperas, and alum, all arrest the decay of timber. (_See p. 426._)
Q. _Why will strong SOUCHONG TEA POISON FLIES?_
A. Because it produces _prussic acid_, which destroys their _nervous system_.
Q. _Why is strong GREEN TEA UNWHOLESOME?_
A. Because it contains _prussic acid_, which destroys the _nervous system_.
Q. _Why is a DEAD man TALLER than a living man?_
A. Because at death the CARTILAGES are _relaxed_. So, also, after a night's rest, a man is _taller_ than when he went to bed.
Q. _What is SLEEP?_
A. Sleep is the _rest of the brain_ and _nervous system_.
Q. _Why can we not SEE, when we are asleep with our EYES OPEN?_
A. Because the "RET'INA of the eye" is _inactive_ and at rest.
