VI 
enemies. With this object he has for several 
yeai-s devoted liimself carefully to the observa- 
tion of the habits and history of those animals, 
and has tried a great number of experiments for 
their destruction, the result of which he now lays 
before the public. He has thought it necessary 
to give a description of the appearance and habits 
of the different insects to be destroyed, as well as 
a short history of their different changes and pro- 
cesses, that every one may be able to detect 
them, and may understand at what times the 
Recipes can be applied with effect, and when, 
from the state of the insect, they and all other 
remedies will be quite useless — ^a point of great 
importance, but one which has been hitherto 
altogether neglected. If the Recipes are found 
to be effectual, he will have effected all that he 
intended; he has not been in the habit of writ- 
ing, but ventures to hope that the usefulness of 
the information which he communicates, will 
apologize for the defects of the style and 
composition. 
Knostrop, near Leeds, 
Jan. 1, 1820. 
