I 791* ON REARING STLK-WORMS I>f SCOTLAND. I 73 



the whole ftock, fo as not to leave a fingle individual 

 to propagate the fpecies. Thefe are grievous calami- 

 ties, which tend greatly to abridge the profits, and to 

 render the buiinels precarious and dangerous. For 

 thefe reafons, the worms dare not be entrufted with 

 fafety, without doors, in warm regions ; though nei- 

 ther can they be fo conveniently managed within doors. 

 But in Britain this inconvenience could not be expe- 

 rienced. Our heat?, are never fo excellive as to be in 

 danger of weakening this animal ; nor are our colds 

 during the fnmmer months ever fo intcnfe, .as to prove 

 in the fmalleil degree ' dangerous to them. And as to 

 thunder, it fo feldom happens, and it would be fo eafy 

 here to proteft them from danger wlien it did comej 

 that our advantage over others in this refpeA is very' 

 great. 



The efFe£ls of climate on this infe£t, as above repre- 

 fented, are fo different from what will be in general 

 apprehended, that I fliould not have dared to mention 

 them, except upon very good authority. The Rever- 

 end Mr. George Swayne of Pickle-chuixh near Briftol, 

 who obtained the filver medal from the Society of Arts 

 in London, for his communications refpecling the rear- 

 ing of filk-worms, invented a cheap portable caie for 

 keeping the worms (a defcription of which, with im- 

 provements, fliall be given in fome future number of 

 this work) with a view to enable the poor who might 

 engage in this employment to manage them with pro- 

 priety. To afcertain what may be the effects of keep- 

 ing them in the open air in this climate, he tried the 

 following experiments. 



" In the latter end of May lafl (the 28th 1788) I 

 put a number of filk-worms (fewer than a hundred) 

 which were then jull hatched in the frame (the frame 

 is quite open on all iides), and placed it in my garden. 

 The weather at that time was cold and windy : In the 

 vcning, the frame was removed into an out-houfe, 

 j'ud returned to the garden next morning. This was 



