and the Mode of its Communication. i8i 
a pellisse would be warmest when worn with the hair outwards, 
as I have found it to be in fact. 
The point here in question is by no means a matter of small 
importance; for, until the principles of the warmth of clothing 
be understood, we shall not be able to take our measures with 
certainty, and with the least possible trouble and expence, for 
defending ourselves against the inclemencies of the seasons, and 
making ourselves comfortable in all climates. 
The fur of several delicate animals becomes white in winter, 
in cold countries ; and that of the bears which inhabit the polar 
regions, is white in all seasons. These last are exposed alter- 
nately, in the open air, to the most intense cold, and to the 
continual action of the sun’s direct rays during several months. 
If it should be true that heat, and cold, are excited in the manner 
above described, and that white is the colour most favourable 
to the reflection of calorific and frigorific rays, it must be ac- 
knowledged, even by the most determined sceptic, that these 
animals have been exceedingly fortunate, in obtaining clothing 
so well adapted to their local circumstances. 
The excessive cold which is known to reign, in all seasons, 
on the tops of very high mountains, and in the higher regions 
of the atmosphere, and the frosts at night, which so frequently 
take place on the surface of the plains below, in very clear and 
still weather, in spring and autumn, seem to indicate, that fri- 
gorific rays arrive continually at the surface of the earth, from 
every part of the heavens. 
May it not be by the action of these rays that our planet is 
cooled continually, and enabled to preserve the same mean 
temperature for ages, notwithstanding the immense quantities 
