COMMERCIAL VALUE OF SPIDER SILK. 89 
* 
Stillbers has made cloth of spider’s silk which has been employed for 
purposes of surgery. He only uses tropical spiders, from which, thanks to 
a scientific culture, he has obtained a much greater return than 
An Bng- was foreseen by Reaumur. The spiders which he uses are large 
lishman’s 5 ; : : 
Attempta SPecies from America and Africa. They are placed in octagonal 
cases, where a sufficiency of insects is served to them every day. 
In the room where the cases are kept a constant temperature of 60° Fahren- 
heit is maintained, and a liquid composed of chloroform, ether, and fusel 
oil is allowed slowly, to evaporate. That is to say, spiders spin best when 
they are under the influence of an anesthetic, as Professor Wilder had 
suggested, the reason for which has heretofore been alluded to. 
Mr. Stillbers is said to keep five thousand of these cases in a room forty 
yards long by twenty wide and five high. The spiders lay eggs of various 
colors, enclosed as usual with cocoons. These are gathered up and pre- 
pared by the same mechanical and chemical operations as the cocoons of 
the Bombyx moth. One cocoon yields one hundred and twenty to one 
hundred and fifty yards of thread by a process which is kept absolutely 
secret. The stuff obtained has a texture resembling ordinary silk, but 
thick, stiff, and a dirty color. It is all the more necessary to bleach it, 
because the color is by no means uniform. It is bleached by treatment 
with oxygenized water. hen it is tanned and softened, when it assumes 
a pretty yellow tint, and becomes brilliant and smooth. 
To make a thread say a mile in length requires between forty and fifty 
cocoons. This is a great advance on Reaumur’s calculations, but still 
falls far short of a practical industrial success. The stuff obtained must. 
be sold at a very high price in order to obtain the merest compensation 
for all this trouble and expense. Thus, the last attempt at economizing 
the silk product of spiders returns to the method of Bon, to utilize the 
cocoon, and abandons the reeling process of Termeyer and Wilder. 
