115 [ 175 ] 



We may conclude, that the silkworm, in forming this cocoon, draws 

 a thread of half a mile in length.* 



It requires 12, SCO cocoons, with healthy chrysalides, to weigh 1000 

 ounces. 



Seven pounds and a half of " calcined worms" contain about 44 

 ounces of pure cocoons. As these cocoons yield about 12 ounces of 

 spun silk, out of 21 ounces of pure cocoons, it is evident, that from 

 500 ounces of pure cocoons, may be drawn — 



In spun silk, about . - . . osh oz. 



Coarse flos - - - - -21i 



50 



Seven pounds and a half of stained cocoons, containing calcined 

 fhrysalides, that is, 120 ounces, contain about 50 ounces of pure co- 

 coons; but, as in stained cocoons, there is always a part of the sub- 

 stance spoilt, the spinner cannot foretcl whether from seven pounds and 

 a half of cocoons, he will obtain one-half of the quantity that the 

 liealthy cocoons would yield him; the less the silk, the gi'eater will be 

 the proportion of coarse fios, and the flos is worth less than the co- 

 coons of the healthy chrysalis; one thousand of these stained cocoons 

 weigh a pound and a half. 



. Generally, it is not possible to separate the decayed chrysalis from 

 the cocoon, the worm being turned into a black soapy substance, 

 sticking to the inside of the cocoon, sometimes the mummy is black, 

 and sometimes detached. A part of these cocoons may be spun; but 

 the silk is never so fine as that from healthy cocoons. Eight hundred 

 and sixty of these cocoons weigh a pound and a half. 



Facts relative to the production of eggs. 



Three hundred and sixty cocoons, of the finest quality, weigh aboui 

 25 ounces. If we suppose half of these to be females, these will be 

 about ISO. Each impregnated moth will laj'', on an average, 510 

 eggs. This number is equivalent to Ih grains, as 68 eggs weigh a 

 grain. The ISO female moths, consequently, lay 91,800 eggs, which 

 weigh 1,350 grains, or about two ounces and one-third. If the 91,800 

 eggs yielded an equal number of silkworms, and if well managed, and 

 they each formed a cocoon, we should obtain 382 lbs. S ounces of co- 

 coons, which the following year would yield eggs sufficient to produce 

 97,537 lbs. 8 ounces.t Bonafous says, J that 14 ounces of cocoons will 

 produce, on an average, an ounce of eggs. According to Pullein, a 

 hundred pair of moths will produce about an ounce. 



* In the Abbe Rosier's Corns d' Agriculture, it is stated tliat one single thread, 

 forming' a whole cocoon, i% three miles long-. 



I Dandolo. t lie I.'Educatian dea Vers a Soie;^ p. 85 



