Unfortunately for our health and comfort, the teachings of science are
too often disregarded, if they interfere with our habits. Science,
when not practically applied, loses its value; it wants fixedness,
stability. Its application is its embodiment; without it, it is a mere
figment of the brain. Its business is to inform the mind, and remove
erroneous impressions; and its highest aim is usefulness. The popular
belief with respect to dress, that a black dress is warmer, both in
winter and summer, than a white one, is erroneous. The truth is that,
the material being the same, a black dress is cool in winter and warm
in summer--while a white one is warm in winter and cool in summer;
that is to say, the one is cool when we require warmth, and warm when
we require to be cooled; while the other is warm when we are cool, and
cool when we are warm, and thus answers the purpose of dress, which
is, to protect the body from the influence of the weather.
Science teaches that dark colours absorb heat, and part with it much
more rapidly than light ones; black and white being the two extremes.
How strange that this knowledge has not been applied to dress! If the
bowls of two spoons, the one polished, and the other smeared with
soot, be held near a fire, it will be found that the blackened one
becomes hot much sooner than the other; and if now they be both made
hot by holding them against the bars of the grate, and then removed
from the fire, and suspended in the air, it will be seen that the
blackened one will get cool much sooner than the other. It is true
that the difference in this case is chiefly due to the polish on one
of the spoons, but it is not altogether due to it. Again: if hot water
be poured into two vessels, the one white and the other black, the
water in the latter will cool before the other. So likewise if two
persons, one dressed in black and the other in white--all other
conditions being the same--were to go from the cold external air into
a heated room, the one in black would feel the heat sooner than the
other, and on leaving the room would feel the cold sooner;
consequently, would be more likely to take cold than the other. It is
therefore evident that a light-coloured dress is more conducive to
health and comfort than a dark one, since it prevents the external
heat or cold from too suddenly reaching the body, and prevents the
body from too suddenly parting with its heat; and thus, that it keeps
it in a more equable temperature.
We may now understand the reason why animals in the polar regions are
white--their whiteness preserves the heat of their bodies much better
than any other colour. So likewise the earth, in consequence of the
whiteness of snow, is prevented from parting with its heat. It is not
so much by snow protecting the earth from the external cold, that it
does such valuable service, as by its preventing the _radiation of the
internal heat_. This whiteness of snow, and of the polar animals, must
not be looked upon as the result of blind chance: it strikingly
exemplifies the wisdom and goodness of the Creator.
The above observations are peculiarly applicable to the case of men
engaging in arctic expeditions. I do not know what dress they usually
wear, but it is quite clear that a white woollen one would be the most
appropriate; and if it had a gloss upon it, it would be so much the
better. This they might have learned from observing the animals in
those regions.