AGRICULTURE WITH CHEMISTRY. 



139 



plants ; thus rendering them unfit for the food of such 

 insects. The effedts of soot are not confined to the de- 

 stru6tion of inse6ls alone ; for the resinous bituminous 

 oil, dissolved by the saline matters, promotes the growth 

 of plants in a very high degree, and by rapidly pushing 

 them to an advanced state of maturity, allows no time 

 for the ravages of inserts on the young and tender roots 

 and leaves of plants, on which, in general, they princi- 

 pally feed. 



The quantity of soot that can be collected, is so incon- 

 siderable, in proportion to its uses, and .the demand 

 there might be for it, were its powers more generally 

 known, that a method of procuring a greater supply of 

 this essential article, or of any substance that would pro- 

 duce similar good effects, is an object of very great im- 

 portance to Agriculture. This is to be accomplished by 

 different preparations, amongst which coal-tar is to be in- 

 cluded. The chemical analysis, and deleterious or poison- 

 ous effects of coal-tar on insefts, prove its identity to soot ; 

 the only difference being, that of its containing less fuligi- 

 nous, or carbonaceous and earthy matters : in which re- 

 spects, as carbonaceous and earthy matters arc not soluble 



s 2 m 



