O F S I L K. 223 



vantage of opening that aperture, which 

 is on the windward lide, when the room 

 wants to be fuddenly and thoroughly clear'd 

 of the foul air thus forced thro' the fun- 

 nel. 



If it be inconvenient to carry up a fun- 

 nel as mentioned above, then an aperture 

 made through the wall, clofe to the ciel- 

 ing, may ferve tolerably well to carry of 

 the unwholefome air, provided you ufe 

 fome of the apertures which I have men- 

 tioned, for the admiflion of frefh and whole- 

 fome air. Thus, if the proper cleaning of 

 the worms, and the due admillion of frefli 

 air be pradlifed, the diftempers arifmg from 

 dirt and putrefa6lion will be prevented, 

 fo, far as they arife from the manner in 

 which people are obliged to keep filk worms 

 in houfes j and, until fuch cleanlinefs and 

 airing of the rooms is obferved, theie will 

 be always complaints, as there are at pre- 

 fent in the countries which breed filk- 

 worms, of unaccountable mortality among 

 the worms of fome perfons, . while thofe 

 of others remain healthy. But the fmell of 

 the room will give warning of the danger, 

 and point out the bell cure, which is pre- 

 vention. ^^£jil 



4iir/ It 



