142 THE SILK-WORM. 



external injury. For this purpose, a room is chosen with a 

 southern aspect, the windows of which are so well glazed as not 

 to admit of the least air when it is cold. The walls are well 

 built, and the planks of the floor laid close, so as not to admit 

 the entrance of birds, mice, or even insects. In the middle of 

 the room four pillars or posts are erected, and placed so as to 

 form a pretty large square. Between these are diverse stories 

 constructed with ozier hurdles, and under each hurdle is a floor 

 surrounded with an upright border. These all hang upon pillars, 

 in such a manner as to be placed or taken down at pleasure. 



This is the mode of constructing a habitation for the silk- 

 worms generally used by the most skilful breeders of these val- 

 uable insects in European countries. Their food consists of 

 mulberry leaves, of which they must have a fresh supply every 

 morning, and the remainder of the old leaves must also be care- 

 fully taken away, and every thing must be kept very clean ; for 

 nothing is so hurtful to them as uncleanness and moisture. For 

 this reason the leaves must be gathered when dry, and kept in a 

 dry place, if it be necessary to lay in a store. If mulberry leaves 

 cannot be obtained, the leaves of lettuce or hollyoak will sustain 

 the worms ; but they will not thrive so well upon this diet ; their 

 silk will neither be so abundant nor of so good a quality. Al- 

 though the judicious choice and careful management of their 

 diet, with a strict attention to cleanliness, be absolutely necessary, 

 there is yet another precaution of equal importance, — which is, 

 to give them air, by opening the windows at such times as the 

 sun shines with the greatest heat and clearness. 



As the silk-worm has but a short time to live, it makes use of 

 every moment, and is almost constantly spinning, except at those 

 intervals when it changes it skin. The cone or ball of silk in 

 which it envelopes itself, and which Nature has taught it to form 

 with such exquisite art, is spun from two little longish bags, 

 placed above the intestines, and filled with a gummy fluid of a 

 marigold colour. This is the substance of which the threads are 

 formed ; and the little animal is furnished with a wonderful ap- 

 paratus for spinning it out to the degree of fineness, which its oc- 

 casions may require. This instrument in some measure resem- 

 bles a wire-drawer's machine, in which gold or silver threads 

 are drawn to any degree of minuteness. The whole length of 

 thread composing one of the cones will, if measured, be found 

 to be about three hundred yards ; and it is so very fine, that 

 eight or ten threads are generally reeled off into one by the 

 manufacturers. The cone appears to be of the size of a pigeon's 

 egg. When this is completed, and the worm appears ready to 

 burst out, the manufacturers generally take care to kill the 

 aurclia, by exposing it either to the sun or to an artificial heat- 



