EESEAKCHES UPON SPIDERS. 65 



take, both being of the same quality, and the difference con- 

 sisting in the threads of the second being more multiplied. 

 But, however this may be, it is of little importance, as I do 

 not purpose to draw any profit from the webs of the spi- 

 ders;^ The silk of the spider's cocoon is, according to Reau- 

 mur, five times more delicate, and therefore more weak than 

 that of the silk-worm, which he ascertained by experiment; 

 since while a thread of silk from the last sustained 180 

 grains, a thread from the first sustained only 36. He in- 

 ferred from that another defect, that is, the necessity of 

 combining many threads, in order that they may have any 

 strength whatever, which ought to and does injure their 

 brilliancy, which is still impaired by the impossibility of 

 spinning, and the necessity of carding the cocoons, reducing 

 the threads not to silk, but to floss, or to coarse sewing silk. 



But are these defects revealed by Reaumer in the silk 

 of the spider really such ? Are they truly defects ? The 

 fineness of the thread will not certainly be considered a 

 defect, since otherwise we ought to prefer to the cocoon of 

 the common silk-worm, that is the moth of the mulberry 

 tree (Phalana Mori L.), that of the Phaltena pavonia, which 

 has many threads, larger and of more consistency ; a state- 

 ment which no intelligent judge of silk will make. The 

 delicacy of the thread of the spider's silk should not there- 

 fore be considered a defect ; and if, on account of this deli- 

 cacy, the thread is weak, as it must be, we have only to 

 combine more threads in order to obtain the necessary firm- 

 ness. Are not the very threads of the silk-worm's cocoon 

 combined in order to produce a thread strong enough for 

 manufacturers ? 



I agree with Reaumer that by reducing the cocoons of 

 the spider to the state of ferret (coarse sewing silk ?), and 

 spinning them then with the distaff, they lost their native 

 brilliancy ; but here it is proper to note two things : — - 



8. I speak of the European since the great spiders of which I have 

 spoken make webs so strong that their threads sometimes incommode those 

 who walk in the roads occupied by them, and more than once they have 

 made me fall before the thread has broken. The same spider has been ob- 

 served in Mexico (see Blosin Busch) where there are also spiders which 

 make webs of many colored threads. 



COMMUNICATIONS ESSEX INSTITUTE, VOL. V. 10. JULY 31, 1866. 



