200 NORTH AMERICAN INSECTS. 



oni y, eighteen miles below Pittsburg, on the Ohio, 

 -which were manufactured there out of silk of their 

 own raising. But this is like a drop of water to the 

 vast ocean, in a country of so immense an area, and 

 of a population that will soon reach fifty millions. It 

 is not a visionary project, or a " moras multicaulis" 

 speculation, that I would encourage ; but if our gov- 

 ernment would protect this branch of industry by a 

 suitable tariff, the cultivation of silk-worms and the 

 manufacture of silk, could be made a profitable busi- 

 ness. Families in the middle States of the Union, 

 might thus employ many old and infirm men and wo- 

 men, as well as children when not in school, and in 

 the southern States could do the same with negro 

 children, as well as with the old men and women who 

 have become incapacitated for hard work. 



To plant a large number of white mulberry trees, 

 for the purpose of raising silk-worms is neither diffi- 

 cult nor expensive, and whoever raises a large quanti- 

 ty of cocoons may be sure of a ready cash sale of them, 

 and at a great profit. 



All the silks and silk-stuffs of commerce orio-inate 

 from the common silk-worm, but there exist several 

 other species of nocturnal Lepidoptera in America 

 and in Asia, which produce silk of a different kind, of 

 which no use, or a very limited one is made : as for 

 instance, that of the Bombyx Madrono, mentioned in 

 Humboldt's travels, which is found in the province of 



