absorbs heat from the bodies in its vicinity. And as the air which
creeps along the plains, expands itself by a part of the pressure being
taken off when it ascends the sides of mountains; it at the same time
attracts heat from the summits of those mountains, or other bodies which
happen to be immersed in it, and thus produces cold. Hence he concludes
that the hot air at the bottom of the Andes becomes temperate by its own
rarefaction when it ascends to the city of Quito; and by its further
rarefaction becomes cooled to the freezing point when it ascends to the
snowy regions on the summits of those mountains. To this also he
attributes the great degree of cold experienced by the aeronauts in
their balloons; and which produces hail in summer at the height of only
two or three miles in the atmosphere.]

[_Diffuse phosphoric light_. l. 177. I have often been induced to
believe from observation, that the twilight of the evenings is lighter
than that of the mornings at the same distance from noon. Some may
ascribe this to the greater height of the atmosphere in the evenings
having been rarefied by the sun during the day; but as its density must
at the same time be diminished, its power of refraction would continue
the same. I should rather suppose that it may be owing to the
phosphorescent quality (as it is called) of almost all bodies; that is,
when they have been exposed to the sun they continue to emit light for a
considerable time afterwards. This is generally believed to arise either
from such bodies giving out the light which they had previously
absorbed; or to the continuance of a slow combustion which the light
they had been previously exposed to had excited. See the next note.]

[_Beccari's shells_. l. 182. Beccari made many curious experiments on
the phosphoric light, as it is called, which becomes visible on bodies
brought into a dark room, after having been previously exposed to the