276 Silk Manufacture. 



* Some species of spiders are known to possess the power of not mere- 

 ly forming a web, but also of spinning, for the protection of their eggs, 

 a bag somewhat similar in form and substance to the cocoon of the 

 silkworm. At the commencement of the last century a method was 

 discovered in France by Monsieur Bon, of procuring silk from these 

 spiders' bags, and its use was attempted in the manufacture of sever- 

 al articles. The following particulars are gathered from a disserta- 

 tion published at the time by M. Bon, and also from papers on the 

 subject inserted in tlie volumes of the Royal Academy for tlie years 

 1710 and 1711. 



' Spiders are usually classed according to their difference of color, 

 whether black, brown, yellow, Stc, or sometimes by the number and 

 arrangement of their eyes : of these organs some possess no fewer than 

 ten, others eight, and others again six. M. Bon has, however, noticed 

 only two kinds of silk spiders, and these he has distinguished from 

 each other as having either long or short legs, the last variety produ- 

 cing the finest quality of raw silk. According to this ingenious obser- 

 ver, the silk formed by these insects is equally beautiful, strong, and 

 glossy with that formed by the bombyx. The spider spins minute 

 fibres from fine papillae, or small nipples, placed in the hinder part of 

 its body. These papillai serve the office of so many wire-drawing irons, 

 to form and mould a viscous liquor, which after being drawn through 

 them dries on exposure to the air, and forms die silk. 



' The celebrated naturalist M. Reaumur, who likewise bestowed 

 considerable attention on these insects, discovered that each of the 

 papillae consists of a number of-smaller ones, so minute as not to be 

 discernable, and only made evident by the effects produced. If the 

 body of the spider be pressed between the fingers, the liquor from 

 which the threads are formed flows into the papillae, by applying the 

 finger against which, distinct threads m?y then be drawn out through 

 the several perforations of each papilla. These threads are too fine 

 to be counted with any accuracy, but it is evident that very many 

 are sent forth from each of the larger papillae. This fact tends to ex- 

 plain the power possessed by the spider of producing threads having 

 different degrees of tenuity. By applying more or fewer of these pa- 

 pillae against the place whence it begins its web, the spider joins into 

 one thread the almost imperceptible individual filaments which it 

 draws from its body ; the size of this thread being dependant on the 

 number of nipples employed, and regulated by that instinct which 

 teaches the creature to make choice of the degree of exility most 

 appropriate to the work wherein it is about to engage. M. Bon was 

 able to distinguish fifteen or twenty fibres in a single thread, while 

 Reaumur relates that he has often counted as many as seventy or 

 eighty fibres through a microscope, and perceived that there were 



