THE MODERN HISTORY OF SILK. 187 



manufacturing of silk are immensely advantageous, 

 one-fourth part of the price of silk being adjudged 

 enough to pay the whole expenses." 



Mr Swain makes the following judicious remarks 

 on the food of the Silk Worm : " That food," says 

 he, " I am confident will never be found in the leaves 

 of any other tree or plant than those of the mulberry. 

 For although Silk Worms will feed on the leaves of 

 lettuces, and will sometimes spin their web, and go 

 through their several metamorphoses without any 

 other food, when they have been accustomed to that 

 from their first exclusion from the eggs, yet they will 

 never thrive so well, become so large, or spin a web, 

 either so good in quality or so abundant in quantity, 

 as when they have been fed during their whole 

 existence in the larva state on their natural food, 

 mulberry leaves. And supposing the leaves of 

 lettuces to be an equally proper food for them, yet 

 the great extent of land necessary for the growth of 

 lettuces sufficient for the consumption of any con- 

 siderable number of worms, must surely render 

 ineffectual every attempt to raise silk upon that 

 plan." 



What necessity can there be for ranging in quest 

 of other nutriment, when the mulberry tree itself, the 

 acknowledged proper and natural food of these 

 insects, will thrive and prosper in this country as 

 well as most other trees ? In very poor soils, indeed, 

 they grow sparingly. But in soils tolerably rich, 

 either those that are naturally so, or enriched by art, 



