184 THE CULTURE 



The bed fituation for expofmg the balls to 

 the fun is before a foutli wall, or in the 

 angle between two walls which lies open 

 to the fouth, if fuch can be obtained, the 

 refleclion from the wails giving an addi- 

 tional heat. 



It is hard to determine the time which 

 is neceffary to kill the grubs ; in the more 

 temperate climates, the balls will require 

 to be thus expofed three or four fuceffive 

 days 5 the colder climates fuch as England^ 

 will not do it at all efreclually, and, even in 

 the hot ones, you may be difappointed in 

 the weather, and be obliged to repeat the 

 operation, or, at lafl:, to have recourfe to 

 the heat of the oven, or the fleam of fcald- 



ing water. 



The beft method to determine the leaft 

 time which is neceffary to kill them by the 

 heat of the fun, is by expofmg a few dur- 

 ing different lengths of time, and then ob- 

 lerving which is the leafl time which can 

 effectually prevent the moths from pierc- 

 ing, by opening the pod and feeing if the 

 grub is kili'd: you may make this tryal 

 while you are expofmg to the fan all your 

 filk-balls, but the experiment can only 

 be pf feiyice to you the enfuing feafon, for 



yoq 



