ot)2 Li: PI I) OPT ERA. 



over the edges to form a hollow, within which its cocoon 

 is concealed. 



The Luna, Polyphemus, Cecropia, and Promethea moths 

 are the only native insects belonging to the genus Attacus 

 which are known to me. Their larcje cocoons, consistiiiix 

 entirely of silk, the fibres of which far surpass those of the 

 silk-worm in strength, might perhaps be employed in the 

 formation of fabrics similar to those manufactured in India 

 from the cocoons of the tusseli and arrindy silk-worms, the 

 durability of which is such, that a garment of tusseh silk 

 " is scarcely worn out in the lifetime of one person, but 

 often descends from mother to daughter ; and even the cov- 

 ers of palanquins made of it, though exposed to the influ- 

 ence of the wcathei', last many years." The method cm- 

 ployed by the inhabitants of India for unwinding the cocoons 

 of their native silk-worms would probably apply equally 

 well to those of our country, which have not yet, that I am 

 aware of, been submitted to the same process. It is true 

 that experiments, upon a very limited scale, have been made 

 with the silk of the Cecropia, which has been carded and 

 spun and woven into stockings, that are said to wash like 

 linen. The Rev. Samuel Pullein was among the first to 

 attempt to unwind the cocoons of the Cecropia moth, an 

 account of which is contained in the " Philosophical Trans- 

 actions of the Poyal Society of London," for the year 1759.* 

 Mr. Pullein ascertained that twenty threads of this silk 

 twisted together would sustain nearly an ounce more in 

 weioht than the same number of common silk. j\Ir. Lloses 

 Bartram, of Philadelphia, in the year 1767, succeeded in 

 bringing up the caterpillars from the eggs of the Cecropia 

 moth, and obtained several cocoons from them.f In the 

 Paris " Journal des Debats," of the 23d of July, 1840, is 

 an account of the complete success of ]\Ir. Audouin in 



* Vol. LI. p. 54. 



t See " Transactions of the American Philosophical Society of Philadelphia," 

 Vol. I. p. 294. 



