|3'4 Of INSECTS IN GENERA!,. 
life, would thus be more than half depopulated ; and that 
great vivifying principle by which nature is actuated, 
and by which life is multiplied and carried on in all th^ 
elements without a paufe, would then be exerted in a 
great meafure in vain. 
But befides the fupply of food which infects afford to 
the fuperior animals, and their proving the grand inflru- 
jnents in the hand of nature by which fhe fupports life 
throughout her dominions, they have always been deem- 
ed ferviceable in the general fyftem, by preferving the 
falubrity of the air. Over the whole furface of the earth, 
thofe numberlefs productions that enjoy either animal or 
vegetable life, are continually hilling in.to decay, and 
making room for that fucceffion of organized beings 
with which nature conftantly teems ; Hence, it has been 
fuppofed, that the atmofpherc would foon become unfit 
for the fupport of life, did not millions of infects con- 
tinually coufume the carrion, and other fubftances in a 
Bate of putrefaction, and purge the air of the noxious 
effluvia emitted from them. It is probably the office of 
thofe fmall infects who efcape our obfervation, to deftroy 
thofe noxious particles with which that element is im- 
pregnated, and which at certain feafons render it peflilen- 
tial. The operation of this clafs of animals upon putrid 
fubftances, is much more confiderable than a fuperficial 
examination might fuggelt. It has been afierted by the 
meft judicious and difeerning naturajifts, that the produce 
of a dozen of flies will confume a dead carcafe in a 
fflorter fpace than a hungry lion. If this be true, whac 
beneficial effeCls may be produced by that inconceivable 
■number of infeCts, which in warm countries continually 
fwarna in the air ? 
i 
