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bility, being to keep tlie threads at their firft exit, before 

 they are yet hardened by the air, afunder. In fome fpiders 

 thofe protuberances are not fo fenfible ; but in lieu thereof 

 there are tufts of hair, which may ferve the fame office, viz. 

 to keep the threads apart. Be this as it will, there may 

 threads come out at above a thoufand different places in 

 every papilla ; confequently, the fpider having fix pa- 

 pillx, has holes for above fix thoufand threads. It is 

 not enough that thefe apertures are iramenfely fmall : but 

 the threads are already formed before they arrive at the 

 papilla, each of them having its little Iheath or duft, in 

 which it is brought to the papilla from a confiderable 

 di (lance. 



M. Reaumur traces them up to their fource, and Ihews 

 the mechanifm with which they are made. Near the origin 

 of the belly he finds two little foft bodies, which are the 

 firft fource of the filk. Their form and tranfparcncy re- 

 femble thofe of glafs-beads, by which name we fhall hereafter 

 denote them. The tip of each bead goes winding, and 

 makes an infinity of turns and returns towards the pa- 

 pilla. From the bafe, or root of the head, proceeds another 

 branch much thicker ; which winding varioufly, forms feve- 

 ral knots, and takes its courfe hke the other, towards the 

 hind part of the fpider. In thefe beads and their branches, 

 is contained a matter proper to form the filk, only that it is 

 too foft. The body of the bead is a kind of refervoir, and 

 the two branches two canals proceeding from it. A little 

 fai-ther backwards, there are two other lefler beads, which 

 only fend forth one branch a-piece, and that from the tip. 

 Belide thefe, there are three other larger vcfTels on each fide 

 of the fpider, which M. Reaumur takes for the laft refer- 

 voirs, where the liquor is coUefted. The biggeft is near the 

 head of the infeft, and the leaft near the anus. They all 

 terminate in a point ; and from the three points of thefe three 

 refervoirs it is, that the threads, at leaft the greateft part 

 of the threads drawn out at the three papillx, proceed. 

 Each refervoir fupplies one papilla. Laftly, at the roots of 

 the papillae, there are difcerned feveral flefhy tubes ; pro- 

 bably, as many as there are papillae. Upon lifting up the 

 membrane, or pellicle, that feems to cover thefe tubes, they 

 appear full of threads, all diftinft from each other, and 

 which, of confequence, under a common cover, have each 

 their particular one ; being kept like knives in ftieaths. The 

 immenfe quantity of threads contained here, M. Reaumur 

 concludes, upon tracing their courfe, does not wholly come 

 from the points of the refervoirs ; but fome from all the 

 turns, and angles ; nay, probably from every part of it. 

 But by what conveyances the liquor comes into the beads, 

 and out of the beads into the refervoirs, remains yet to be 

 difcovered. 



We have already obferved, that the tip of each papilla 

 may give paftage to above a thoufand thre.ids ; yet the dia- 

 meter of that papilla does not exceed a fmall pin's-head : 

 but we were there only confidering tiie largeft fpiders. 



If we examine the young growing fpiders produced by 

 thofe, we ftiall find, that they no fooner quit their egg, than 

 they begin to fpin. Indeed their threads can fcarce be per- 

 ceived ; but the webs may : they are frequently as thick, 

 and clofe, as thofe ot houfe-fpiders ; and no wonder : there 

 being often four or five hundred littl? fpiders concurring to 

 the fame work. How minute muft their holes be ? the 

 imagination can fcarce conceive that of their papillx ! The 

 whole fpider is, perliaps, lefs than a papilla of the parent 

 which produced it. 



This is eafily feen ; each big fpider lays four or five hun- 

 dred eggs ; thefe eggs are all wrapped up in a bag ; and as 



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foon as the young ones have broke through the bag, tl.ey 

 begin to fpin. How fine muft their threads at this time 

 be! 



Yet is not this tlie utmoft nature does : there are fome 

 kinds of fpiders fo fmall at their birth, that thev are not vi- 

 fible without a microfcope. There is ufually found an in- 

 finity of thefe in a clufter, and they only appear like a 

 number of red points. And yet there are webs found 

 under them, though well nigh imperceptible. What muft 

 be the tenuity of one of thefe threads ; the fmalleft hair 

 muft be to one of thefe what the moft maflive bar is to the 

 fineft gold-wire. 



The matter of which the threads are formed, v;e have ob- 

 ferved, is a vifcid juice. The beads are the firft receptacles 

 where it is gathered, and the place where it has the leaft con- 

 fiftcnce. Il is much harder when got into the fix great re- 

 fervoirs, whither it is carried by canals from the former ; 

 this confiftence it acquires in good meafure in its paflage ; 

 part of the humidity being diffipated in the way, or fecreted 

 by parts dcftined for that purpofe. 



Laftly, the liquor is dried ftill farther, and becomes 

 thread, in its progrefs through the refpeftive canals to the 

 papillx. When thefe firft appear out at the holes, they are 

 ftill glutinous ; fo that fuch as fpring out of neighbouring 

 holes ftick together. The air completes the drying. 



By boiling the fpider, more or lefs, the liquor is brought 

 to a greater or lefs confiftence, fit to draw out into threads ; 

 for it is too fluid for that purpofe while yet inclofed in its 

 refervoirs. 



The matter contained in thefe refervoirs, when well 

 dried, appears a tranfparent gum, or glue, which breaks 

 when much bent : like glafs, it only becomes flexible by 

 being divided into the fineft threads. And probably it was 

 on this account nature made the number of holes fo immenfe. 

 The matter of filk formed in the bodies of fpiders being 

 much more brittle than that formed in filk-worms, needed 

 to be wound fmaller. Othcrwife we do not conceive, why 

 they ftiould form a great number of threads, which were 

 afterwards to be re-united : a fingle canal might elfe have 

 done. 



The thread of a fpider being ftrong enough to bear five 

 or fix times the weight of the fpider's body, is cpmpofed of 

 feveral finer threads, that are drawn out feparately, but 

 unite together at the diftance of two or three hairs' breadth 

 from the body of the fpider. The threads are coarfer or 

 finer, according to the fize of the fpider that fpins them. 

 Mr. Lcewenhoeck computes that lOO of the fineft threads of 

 a full grown fpider, are not equal to the diameter of the 

 hair of his beard ; and confequently, if the hair be round, 

 lo,oco fuch threads are not bigger than fuch a hair. He 

 calculated farther, that when young fpiders firft begin to 

 fpin, 400 of them are not larger than one that is full-grown ; 

 and therefore the thread of inch a little fpider is 400 times 

 fmaller than the thread of a full-grown one ; allowing this, 

 four millions of a young fpider's threads are not fo big as 

 the fingle hair of a man's beard. 



Web, in Ship-BtiiUing, the thin partition on the infide of 

 the liin, and between the fpokes of an iron or brafs-ftieavc. 



Web of a Coulter, in ylgriculliire, that part of it which is 

 drawn out thin and fliarp, in order to cut and feparatc the 

 ground, in oppofitiou to the others which are thick and 

 blunt. In the fock, too, any thin (harp poj-t has the name 

 of web or wing. 



Web on the Eye, among Animals, a term fometimes ufed 

 to fignify a film on that part. See E^'e, Film, and Whitt 

 Film. 



Web- 



