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for cardinp ; which was pe-rformcd by the common filk- 

 carders, but with cards much tiner than ordinary. By tins 

 means, he had a filk, of a very particular afh-colour, which 

 was cafily fpun ; and the thread fpun fro:yi it was both 

 ftrongier and finer than that of common filk ; which ftiews, 

 that all forts of works may be made of it : nor is there any 

 reafon to fear, but it will Hand any trials of the loom, after 

 having patTcd that of the (locking-weavers. 



The only difHculty, now, is in procuring; a fufiicient 

 quantity of fpider-bags to make any confiderable work of 

 it ; which, M. Bon nbferves, would be no difficulty at all, 

 had we-but the art of breeding them, as we do filk-worms ; 

 for they multiply much more ; every fpider laying fix or 

 feven hundred egg?, whereas the filk-worms do not ky 

 above one hundred : yet are thcfe lad fo tender, &c. that 

 one half die without making any bags, or are hindered, by 

 fome little accident, from making them ; whereas the fpiders 

 hatch of themfelves, without any care, in the months of 

 Augull and September, in fifteen or fixteen days after they 

 are laid ; the old fpiders that lay them dying foon after. 

 The young ones thus bred live ten or twelve months with- 

 out eating, and continue in their bags without growing, 

 till the hot weather, putting their vifcid juices in motion, 

 induces them to come forth, fpin, and run about to fcek 

 food. Were a method, therefore, found of breeding young 

 fpiders in rooms, they would, doubtlefs, furnifh a much 

 greater quantity of bags than filk-worms do. For of feven 

 or eight hundred young fpiders, which M. Bon kept, hardly 

 one died in a year ; whereas of one hundred filk-worms, not 

 forty lived to make their bags. M. Bon, having ordered 

 all the fhort-legged fpiders that could be found in the 

 months of Augull and September to be brought to him, 

 fliut them up in paper coffins, and pots ; covering the pots 

 with papers, which he pricked full of pin-holes, as well as 

 the coffins, to give them air. He fed them with flies, and 

 found, fome time afterwards, that the greatefl part of them 

 had made their bags. The fame ingenious perfon found, 

 that fpiders' bags, with regard to their weight, afford 

 much more filk than thofe of the filk-worms : as a proof 

 of which, he obferves, that thirteen ounces yield near four 

 ounces of clear filk, two ounces of which will make a pair 

 of (lockings ; whereas (lockings of common filk weigh feven 

 or eight ounces. 



Nor is there any venom in the filk, or even in the fpider, 

 as many have imagined. M. Bon has been bit by them le- 

 vcral timeR, without any manner of harm ; and as for the 

 filk, it is ufed with very good fuccefs to (lop bleeding, and 

 cure wounds, the natural gluten of it afting as a kind of 

 balfam. It likewife yields, by dillillation, feveral fpecific 

 medicines, particularly great quantities of fpirit, and vola- 

 tile fait, which being prepared after the fame manner as 

 that drawn from the bags of filk-worms, in making the 

 gutto! Anglicanac, or Englifh drops, at one time fo famous 

 all over Europe, may ferve to make other drops of greater 

 efficacy, which M. Bon calle drop; of Montpelier, and ad- 

 vifes to be ufed in all (leepy difeafes.* 



M. Reaumur, being appointed by the Royal Academy 

 to make a farther inquiry into this new filk work, ha^ railed 

 feveral objections and difficulties againil it ; which are found 

 in the Memoirs of the Academy for the year 1710. The 

 fum of what he has urged amounts to this. The natural 

 fiercenefti of the fpiders renders them unfit to be bred and 

 be kept together : four or five thouf.md being diitributed 

 into cells, fifty in fome, one or two hundred in others, the 

 big ones foon killed and eat the lefs, fo that, in a (hort time, 

 there were fcarcely left one or two in each cell ; and to this 



inclination of mutually eating one another, M. Reaumur 

 alcribcs the fcarcity of fpiders, confidering the vatl number 

 of eggs they lay. 



But this is not all : he even affirms, th»t the fpider's bag 

 is inferior to that of the filk-worm, both in ludre and 

 (trcngth ; ard that it produces lefs matter to be manufac- 

 tured. The thread of the ipider's web, he fays, only bears 

 a weight of two grains without breaking; and that of the bag 

 bears tliirty-fix. The latter, therefore, in all probability, 

 is eighteen times thicker than the former ; yet it is weaker 

 than that of the filk-worm, which bears a weight of two 

 drachms and a half : fo that five threads of the fpider's bag 

 mull be put together, to equal one thread of the filk-worm's 

 bag. 



Now it is impoffible thefe (hould be applied fo judly over 

 one another, as not to leave little vacant fpaces between 

 them, whence the light will not be leflefted ; and of con- 

 fequence, a thread, thus compounded, mud fall (hort of 

 the ludre of a folid thread. Add to this, that the fpider's 

 thread cannot be wound o(F, as that of the filk-worm may, 

 but mud of neceffity be carded ; by which means, being 

 torn in pieces, its evennefs, which contributes much to its 

 ludre, is dedroyed. In effedl, this want of ludre was taken 

 notice of by M. de la Hire, when the dockings were pre- 

 fented to the Academy. 



Again : fpiders furnidi much lefs filk than the worm? ; 

 the largcll bags of thefe latter weigh four grains ; the 

 fn-.aller, three grains ; fo that 2304 worms produce a pound 

 of filk. The fpider-bags do not weigh above one grain ; 

 yet when cleared of their dud and filth, they lofe two- 

 thirds of their weight. The work of twelve fpiders, there- 

 fore, only equals that of one filk-worm ; and a pound of filk 

 will require at lead 27,648 fpiders. But as the bags are 

 wholly the work of the females, who (pin them to depofit 

 their eggs in, there mud be kept 55,296 fpiders to yield a 

 pound of filk. Yet will this only hold of the bell fpiders ; 

 tho(e large ones ordinarily feen in gardens, &c. fcarcely 

 yielding a twelfth part of the filk of the others : 280 of 

 thefe, he (hews, would not yield more than one filk-worm ; 

 663,552 of them would fcarcely yield a pound. 



Su.K-Gra/s, in Botany, a name ufed for two very dif- 

 ferent genera of plants, the aloe, and dog's bane. 



SlLK-'Inil, or Bohemian Chatterer, in Oi .lithology. See 

 RoLl.Eli. 



Sli.K, Virginian, in Botany. Sec Peiuploca. 

 SlI.K- /form, Bombyx. This infedl, which is a fpecies of 

 the phalxna, (fee Bo.mbvx,) coiifids of eleven rings, and 

 each of thefe of a great number of other (mailer ones, joined 

 to each other ; and the head, which terminates thcfe rings, 

 is furnifhed with two jaws, wliich work and cut the food, not 

 by a perpendicular but a lateral aftion. 



Tlie humours found in the body of this creature all fcem 

 approaching to the nature of the filk which it fpins ; for 

 on being rubbed in the hands, they leave a hard or (olid 

 crud behind them. Under the Ikiii there is always found a 

 mucous roly-coloured membrane, enveloping the animal, 

 and fuppofed to be the new flcin in which it i.s to appear, on 

 throwing oil the old one. The heart of this creature reaches 

 from the head to the tail, running the whole length of the 

 body ; it is, indeed, rather a feries of many hearts tonncded 

 together, than one : the motion of fydole and diadole is very- 

 evident in this whole chain of hearts ; and it is an elegant 

 fight to obferve the manner of the vital fluid's palling from 

 one of them to the other. The domach of this animal is at 

 long as the heart, reaching, like it, from one end of the body 

 to tlie other, This large receptacle for food, and the fnd- 

 4Y 2 den 



