330 NATURAL HISTORY 
oped in a viscous substance, and loaded with black 
aphides, or smother-flies. ‘The occasion of this 
clammy appearance seems to be this, that in hot 
weather, the effluvia of flowers in fields, and 
meadows, and gardens are drawn up in the day by 
a brisk evaporation, and then in the night fall down 
again with the dews in which they are entangled ; 
that the air is strongly scented, and therefore im- 
pregnated with the particles of flowers in summer 
weather, our senses will inform us; and that this 
clammy sweet substance is of the vegetable kind 
we may learn from bees, to whom it is very grate- 
ful; and we may be assured that it falls in the 
night, because it is always first seen in warm, still 
mornings.* 
On chalky and sandy soils, and in the hot vil- 
lages about London, the thermometer has been 
often observed to mount as high as 83° or 84°; 
but with us, in this hilly and woody district, I have 
hardly ever seen it exceed 80°, nor does it often 
arrive at that pitch. ‘The reason, I conclude, is, 
that our dense clayey soil, so much shaded by 
trees, is not so easily heated through as those 
* Humming in the air.—There is a natural occurrence to be 
met with upon the highest part of our down in hot summer days, 
which always amuses me much, without giving me any sat- 
isfaction with respect to the cause of it; and that is, a loud, 
audible humming of bees in the air, though not one insect to be 
seen. Any person would suppose that a large swarm of bees 
was in motion, and playing over his head. 
‘‘ Resounds the living surface of the ground, 
Nor undelightful is the ceaseless hum 
To him who muses—at noon! 
Thick in yon streams of light, a thousand ways, 
Upward and downward, thwarting and convolved, 
The quivering nations sport.”—THomson’s Sgasons. 
Wuuite, Observations on Insects : 
