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