VARIABLE WEATHER. 
251 
region, in a frame-work of winter. All these things 
assuredly have their effects upon the products of the 
earth, and by their means upon the creatures that are 
nourished by them, carrying on that imperceptible line 
of influences and intelligences that is maintained 
throughout nature. We know that vegetation and the 
atmosphere are in a constant state of barter and ex- 
change, receiving and modifying; and possibly, from 
the unseen effects of a frosty morning, a fall of snow, 
or a few hours’ temperature of the air, a fruitful or an 
unproductive season may arise. We notice the effects 
of spring changes, because vegetation has so far ad- 
vanced as to render influences manifest ; but we cannot 
perceive the injuries of benefits accruing to a hidden 
circulation from particular events. Every person who 
has been conversant with cattle, must have remarked 
how uncertain their progress in improvement has been ; 
that the abundant provision of one year did not prove 
equally nutritive with the scanty product of some other : 
this fact originates probably from the effects of atmo- 
spheric impulse, either directly upon vegetation, or upon 
the soil which produced the food collaterally, or upon 
both collectively. In a wet season, water appears to 
nourish plants, 7 or to supply their requirements princi- 
pally : in a dry one, nutriment must be obtained from 
the soil by means of the fibre of the root, and hence 
particles are imbibed chemically different ; a dry or a 
drained soil, producing short and scanty herbage, will 
frequently improve the condition of cattle more than 
an adjoining meadow having a profusion of food, though 
probably no chemical analysis could indicate the differ- 
ence. These periodical winds again, violent and dis- 
tressing as they often prove, are yet unquestionably es- 
sential in the economy of nature : our two seasons, in 
which these commotions of the air most usually become 
manifest, are about the equinoxes of autumn and spring, 
periods which in many respects have a similarity with 
each other. In the autumn of our year, the foliage of 
trees and plants, &c., putrefy and decay ; marshes and 
dull waters, clogged by their own products, stagnate, 
and discharge large portions of hydrogen, carbonic gas, 
