RESEARCHES UPON SPIDERS. 69 



itories for silk of different colors and adopt now one and 

 now another, not interlacing the colors by design, but accord- 

 ing tp need and circumstances. Others have observed that 

 the silk of which they weave their circular webs, is of dif- 

 ferent kinds, the radii, stretching from the centre to the cir- 

 cumference, differing from the threads which form the con- 

 centric circles ; the second are viscous, but not the first. It 

 is also known to entomologists that the spider has six spin- 

 ners or mammulae, as we will call them, whence the silk issues. 

 Why may we not believe that from each comes a silk, differ- 

 ent either in color or in some other property ? g 



Another quality of spider's silk is the unchangeableness 

 of the original color ; the weight also is unalterable ; that is 

 it did not diminish by any washing or any application of 

 soap to which it was subjected, of which I have assured 

 myself by various experiments made upon different speci- 

 mens of my silk, and especially upon a pair of stockings 

 made of spider's silk and designed for his Majesty Charles 

 III, my beneficent sovereign of glorious memory. 10 



Beside the original color, the silk of spiders may be 

 dyed with whatever color one wishes to give it, excepting 

 that not having usually a white color in the beginning, like 

 the washed silk, the dyes show less clearly. 



I foresee that more than one will say if the silk of 

 your spiders is so adapted to manufactures, if it is so abun- 



g. A valuable suggestion which has been anticipated however, with 

 regard to the Nephila plumipes. [REVISER.] 



10. The silk obtained by carding the cocoons of the diadema spider 

 was spun in my house by Lucrezia Rasponi, who then made of it a pair of 

 stockings of proper size. Having intended them for the King, my Lord, of 

 whom I considered them not unworthy, not so much on account of their 

 value as on account of the novelty of the thing, I sent them to Sig. Car. 

 d'Azan, his Minister, who deigned to assure me that he had sent them to 

 Sig. Conti di Florida Blanca, then Prime Minister of the King, together 

 with my -letter. I cannot understand from what unfortunate combination of 

 circumstances I have never been able to discover if they were truly pre- 

 sented to the King in my name. I know that I was very sensible to the loss 

 of the fruit of so much long-continued investigation and hard work. My 

 many friends who saw them admired their fineness and consistence. They 

 weighed two ounces and a quarter. 



