i 5« ) 



When I firft examined the Silk-worni's thread by the niicrofcope, 

 k Teemed to me not to be of a round form but flat, for the fame 

 tin-ead appeared in fome places four times thicker or broader than 

 in others ; I alfo thought, that each of the threads \vas double, or 

 compofcd of two others, forafmuch as the middle of the thread 

 always feemcd darker than tlie reft, and the whole aj^peared, as if 

 one were to fuppolb, two tranf[)arent threads lying clofe and parallel 

 to each other, and glued or I'aftened together, and each of thefe two 

 threads not to be fo pellucid at the fides as in the middle. 



I next confidered with myfelf, whether thefe fmgle threads might 

 not be compofed of many fmaller ones, and having at length found 

 jneans to break or fcparate them into very fmall fragments, I plainly 

 percei\'ed each of tliem to be compofed of a number of exceirively mi- 

 jiute filaments. 



Farther, I placed a Silk-worm which was beginning to fpin its 

 ball or covering, in a glafs tube, large enough to give the animal 

 liberty to move and turn itfelf about, and I obferved it to fix the 

 thread in various places, fometimes to tlie glafs and afterwards to the 

 threads already fpun, by means of a certain glutinous or gummy 

 matter, with which the threads arc fmeared when they firft iilue 

 from the animal's body. In the progrefs of its fpinning or forming 

 its ball or cone, the Silk- worm frequently changed its pofition, and 

 carried the thread by various turnings and windings in every direc- 

 tion, it being implanted in this creature by nature, always to form its 

 cone or web of an equal fubftance and ftrength in every part next its 

 body. 



Upon examining this cone or ball of filk by the microfcope, I per- 

 ceived in hundreds of places, that the threads of which it was com- 

 pofed, were not fingle but double threads, and this was more parti- 

 ailarly dillinguifliable in thole places where they were bent in a very 

 Ihort elbow or turning in their fixure, either to the glafs or to one 

 another. This is explained at j^^g-. 28, ABCD, which reprefents 



