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, 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, 



