445 



Art. XXI. Miscellaneous hUelligeme, 



I. Mechanical Science. 



§ Agriculture, the Arts, ^c. 



1. Prize Questions in Agriculture and the Arts. — The follow- 

 ing questions have been announced by the Haerlem Philosophi- 

 cal Society. Memoirs on them will be received till January I, 

 1822. 



i. " What information has been obtained respecting the na- 

 ture, habits, and production of those little insects which are so 

 injurious to plants cultivated in hot-houses ; and what method 

 would such information suggest for preventing the propagation 

 of such insects, or for extirpating them ?" 



ii. '* As extensive hot-houses are now heated by steam in 

 England, might not this method be adopted among us for small 

 hot-houses ; and what would be the most proper apparatus for 

 such a purpose ?" 



iii. '* Has experience clearly proved that there are certain trees 

 and plants, particularly of the most useful species, which cannot 

 vegetate when close to each other ? and, in this case, what ex- 

 periments can be adduced as proofs ? Can this antipathy be- 

 tween some species be any way accounted for by what we know 

 of the nature of plants, and what useful information does it 

 supply us with for the cultivation of trees and useful plants ?" 



iv. ** What are the insects most hurtful to trees and shrubs 

 in forests ? In what consists the injuries they produce ? What 

 are the remedies proper to prevent such injuries, or to remove 

 themr 



v. " How far are we acquainted with the (Economy of moles, 

 and what means does it suggest as most efficacious for ridding 

 lands of them where they prove destructive ? Are there, on the 

 contrary, any observations tending to prove that moles are ever 

 useful by destroying other vermin, and how may it be known 

 when moles ought to be tolerated ?" 



vi. " Dry yeast having been substituted for moist in brewing, 

 the society demands * a comparison founded upon chemical 



