A Guide To The Scientific Knowledge Of Things Familiar Part 61

Q. _Why does wine (poured from a bottle QUICKLY) SPIRT about without going into the decanter?_

A. The liquor fills the _top of the decanter_ (like a _cork_), and leaves _no room_ for the air inside _to escape_; therefore, the decanter (being _full of air_) refuses to admit the _wine_.

Q. _Why is BEER made STALE, by being exposed to the AIR?_

A. Because air _absorbs its carbonic acid_, which gave it "life."

Q. _Why is PORTER made STALE, by being exposed to the AIR?_

A. Because air _absorbs its carbonic acid_, which gave it "life."

Q. _Why does the EFFERVESCENCE of soda water and ginger beer so soon go off?_

A. Because air _absorbs the carbonic acid_, which produced the effervescence.

Q. _Why is BOILED WATER FLAT and insipid?_

A. Because the whole of the _carbonic acid is expelled_ by boiling, and _absorbed by the air_.

Q. _Why does WATER become FLAT and insipid, after it has been DRAWN some time?_

A. Because air _absorbs its carbonic acid_; and when its carbonic acid is absorbed, the water is flat and insipid.

Q. _Why should spring WATER (used for WAs.h.i.+NG) be exposed to the AIR?_

A. Spring water _contains carbonic acid_; but (by being exposed to the _air_) this carbonic acid is _absorbed_, and the water becomes _more soft_.

Q. _Why does YEAST make BREAD LIGHT?_

A. Flour contains a small portion of _saccharine matter_ (or sugar); and the yeast (mixing with this) produces _fermentation_, as it does in brewing.

Q. _How does FERMENTATION make the DOUGH RISE?_

A. During fermentation, _carbonic acid gas is evolved_; but the sticky texture of the dough will not allow it to _escape_, so it _forces up little bladders_ all over the dough.

Q. _Why is DOUGH placed BEFORE the FIRE?_

A. 1st--Because the heat of the fire _increases the fermentation_: and

2ndly--It _expands the gas_ which is confined in the little bladders; in consequence of which, the bladders are _blown up larger_, and the dough becomes lighter and more porous.

Q. _Why is BREAD HEAVY, if the dough be removed from the fire?_

A. Because the dough _gets cold_, and then the air in the bladders _condenses_,--the paste falls,--and the bread is close and heavy.

Q. _Whence does the HEAT of FIRE arise?_

A. The _carbon of fuel_ (when heated) _combines with the oxygen of the air_, and produces _carbonic acid gas_: again, the _hydrogen of the fuel_ combining with _other portions of oxygen_, condenses into _water_; by which chemical actions _heat is evolved_.

Q. _Whence does the HEAT of our own BODY arise?_

A. The _carbon of the blood_ combines with the _oxygen of the air inhaled_, and produces _carbonic acid gas_; which produces heat in a way similar to burning fuel.

Q. _Whence does the HEAT of a DUNGHILL arise?_

A. The _straw, &c. of the dunghill_ undergoes _fermentation_ as it decays: the fermentation produces _carbonic acid gas_, and heat is evolved by a species of combustion (as in the two former cases).

Q. _What changes do VEGETABLES undergo from PUTREFACTION?_

A. The _hydrogen of the vegetables_ combines with the _oxygen of the air_, and forms _water_: again, the _carbon of the vegetables_ combines with _oxygen of the air_, and forms _carbonic acid gas_. Putrefaction, therefore, is only another species of combustion.

Q. _What changes do ANIMAL bodies undergo from PUTREFACTION?_

A. The same as vegetables, with this addition--they give out _ammonia_, _sulphur_, and _phosphorus_ also; which causes the _offensive smell_ of putrefying animal bodies.

Q. _Why is LIME heated by a KILN?_

A. All marl and chalk abound _in carbonic acid_; and (when heated by a fire) the carbonic acid _flies off in gas_, producing great heat.

Q. _What is MORTAR?_

A. Lime mixed with sand and water.

Q. _What is LIME?_

A. _Lime-stone burnt_ produces lime.

Q. _Why is the lime-stone BURNT, in order to make it into LIME?_