278 On the Culture of Silk. 



and x'^ -{y^ -'4py^+2p^")x^-\-p^x*-\-c=0; (3) 



eliminating y and p from (3) and we have 



equations (1), (2), (4), and x^-\-yx- -{-px-{-q=0, are sufficient to 

 determine q. 



Art. XL — Practical Instructions on the Culture of Silk, and of the 

 Mulberry Tree in the United States; Vol. 1. and Vol. 11.214 

 pages, 8vo. with plates; hy Felix Pascalis, M. D., Honorar}'^ 

 Member of the Linnaean Society of Paris, &;c. — JVew York, J. 

 Seymour, 1830. 



Essay on Silk, by < 



Mr. D'HoMERGUE, he. and 

 Mr. P. S. DupoNCEAu, he. 



(Communicated.) 



Since the middle of the 18th century, there has never been a 

 greater excitement among commercial nations, towards the promo- 

 tion of the culture of silk, than that which seems to prevail at the 

 present time. Many ancient silk districts of France and Italy fur- 

 nish us with the works of distinguished agriculturalists and philoso- 

 phers, anxiously investigating, either new modes or systems of im- 

 provement, or experimenting on the natural laws which govern this 

 production, or which can command a better quality and greater 

 quantity of it. It is no longer supposed, that the success and 

 benefits derived from its growth can be depended upon, only in warm 

 or southern climates. They are now sought for in the northern lat- 

 itudes of Germany and France, whilst the factors of manufacturing 

 nations ransack all the corners of the world where raw silk can be 

 obtained. We are told also, of new and more perfect sorts of Mul- 

 berry trees, that have been discovered and imported from distant 

 regions, and which are to be authoritatively introduced, to replace an- 

 cient orchards of considerable silk establishments at Pondicherry in 

 Asia, and at Cayenne in South America. This general and simul- 

 taneous excitement has probably been kept up by the long and de- 

 stuctive war in Greece, and other portions of eastern and southern 

 Europe, which were the principal nurseries of silk for the manufac- 

 tories of England, of Lyons, and of Italy. Neverdieless, we rejoice 



