VOL. I.J PHILOSOPHICAL TRANSACTIONS. 31 



particularly in the metropolis of that kingdom, and round about it ; and that 

 for that end the whole way concerning that work and trade should be fully and 

 punctually communicated in print ; which has also been executed by one Mon- 

 sieur Isnard, in a treatise published at Paris, in French, entitled. Instructions 

 for the Planting of White Mulberries, the Breeding of Silkworms, and the Or- 

 dering of Silk in Paris, and the circumjacent Places ; in which book, the me* 

 thod being represented, which that great prince Henry IV. used in establishing 

 the said work and trade, together with the success thereof, and the advantages 

 thence derived to his subjects, the author, from his own experience and long 

 practice, delivers (and seems to do it candidly) all what belongs in this business 

 in four main heads. First, he teaches the means of sowing, planting, and 

 raising white mulberries (as the foundation of silkworks) showing how many 

 several ways that may be done. Secondly, The breeding of silkworms, the 

 choosing of good eggs, and their hatching, as also the feeding of the worms, 

 and preserving them from sickness, and curing them of it, together with the 

 way of making them spin to best advantage. Thirdly, The manner of wind- 

 ing their silk from their bottoms, adding the scheme of the instrument serv- 

 ing for that purpose. Fourthly, The way of keeping silkworms' eggs for the 

 ensuing year. 



Through the whole book are scattered many not inconsiderable particulars, 

 though perhaps known to most. The white mulberry-tree, as it is in other 

 qualities preferable to the black, so this author esteems it the best, not only for 

 the durableness of the wood, and its large extent of usefulness in carpenters' and 

 joiners* work ; but also for the fitness of its leaves (besides their principal use 

 for the food of silkworms) to fatten sheep, goats, cows, and hogs, only by 

 boiling and mingling them with bran. The berries themselves he commends 

 as very excellent to fatten poultry, and to make them lay eggs plentifully. 



Silkworms, before they begin to spin, and about the latter end of their feed- 

 ing, Vnust, says the author, be often changed, and have air enough, by open- 

 ing the windows of the room they are in, if it be not too severe weather ; else, 

 says he, the silk that is in their belly will cause so extraordinary a heat in 

 them, that it will burn their guts, and sometimes burst them ; and the same 

 (being a substance that resembles gum or Burgundy pitch) will putrefy and 

 turn into a yellowish matter. 



As for their working, he gives this account of it : that the first day they 

 make only a web ; the second, they form in this web their cases, and cover 

 themselves all over with silk ; the third day, they are no longer seen ; and the 

 days following they thicken their cases, always by one end or thread, which 

 they never break off themselves. This, he affirms, they put out with so 



