The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million — John Stuart Mill — John Shaqi
The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million
John Stuart Mill · en
When we gaze upon a rose it is not its beauty alone that should
impress us: every moment of that flower's life is devoted to
the fulfilment of its part in the grand scheme of the universe.
It decomposes the rays of solar light, and sends the red rays
only to our eyes. It absorbs or radiates heat, according to the
temperature of the ærial mantle that wraps alike the flower and
the man. It distills the gaseous vapours, and restores to man the
vital air on which he lives. It takes into its own substance, and
incorporates with its own frame, the carbon and the hydrogen of
which man has no immediate need. It drinks the dew-drop or the
rain-drop, and gives forth its sweet odour as a thanksgiving. And
when it dies, it preaches eloquently to beauty, pointing to the
end that is to come!
CHAPTER XII.
226. _How do we know that plants operate upon the solar and atmospheric
heat?_
A delicate thermometer, placed among the leaves and petals of flowers,
will at once establish the fact, not only that flowers and plants have
a temperature differing from that of the external air, but that the
temperature varies in different plants according to the hypothetical,
or supposed requirements, of their existences and conditions.
227. _What is the chief cause of variation in the temperature of
flowers?_
It is generally supposed that their temperature is affected by their
_colours_.
228. _Why is it supposed that the colour of a flower influences its
temperature?_
Because it is found by experiment that the _colours_ of bodies bear an
important relation to their properties respecting _heat_, and hold some
analogy to the relation of _colours_ to _light_.
If when the ground is covered with snow, pieces of woollen cloth,
of equal size and thickness, and differing only in colour, are
laid upon the surface of the snow, near to each other, it will
be found that the relation of _colour_ to temperature will be as
follows:--In a few hours the _black_ cloth will have dissolved so
much of the snow beneath it, as to sink deep below the surface;
the _blue_ will have proved nearly as warm as the black; the
_brown_ will have dissolved less of the snow; the _red_ less than
the brown; and the white the _least_, or none at all. Similar
experiments may be tried with reference to the _condensation
of dew_, &c. And it will be uniformly found that the _colour_
of a body materially affects its powers of _absorption_ and of
_radiation_.
[Verse: "And yet I say unto you, that even Solomon, in all his
glory, was not arrayed like one of these."--MATT. VI.]
229. _Why do we know that these effects are not the result of light?_
Because they would occur, in just the same order, in the absence of
light.
230. _Why are dark coloured dresses usually worn in winter, and light
in summer?_