REARING SILKWORMS. 77 



But these weighted silks are, however, of so 

 combustible a nature, that some have been 

 known to take fire spontaneously, a result due 

 to the gradual decomposition of the substances 

 used for weighting, and disastrous fires have 

 been traced to this cause. Spontaneous combus- 

 tion is liable to break out, more especially in 

 black silks, that are stored in warm, dry places. 



Note 5. 



A very curious silk industry is carried on in 

 Spain since the people became too indolent and 

 careless to manufacture silk into fabrics. The 

 process is called gut-making, and is described as 

 follows: When silkworms are all ready to spin, 

 they take them, and with a sharp instrument cut 

 off both ends. Then they deftly take out both 

 silk-tubes, described fully under another head- 

 ing in this book, and stretch them to the 

 fullest extent, or at least several feet in length, 

 according as the worm is fine and vigorous, or 

 puny from being ill fed. They are handled very 

 carefully as they are unfolded from the convolu- 

 tions in which they were by nature arranged in 

 the body of the worm. They are then passed 

 through several chemical processes or prepara- 

 tions, that serve to cleanse and strengthen them. 

 They are then dried and tied together in bundles. 



