160 QUARTERLY JOURNAL. 



ought not to be so thick as to prevent the sun from reaching their 

 leaves, and the air to circulate freely among them." 



2. As regards the Jd?ids of worms, the preference is very deci- 

 dedly given to the peanut variety, and next to the sulphur. The 

 sulphur are larger than the other. One person mentions that in a 

 trial he made, he found that it took four thousand four hundred 

 peanut cocoons, or two thousand two hundred of the sulphur, to 

 make a bushel. The former gave twenty-two ounces, and the lat- 

 ter fourteen ounces of raw silk. The peanut bushel weighed fif- 

 teen pounds — the sulphur nine and a half pounds ; and it took 

 three hundred peanuts, or two hundred and forty sulphur, to 

 weigh a pound. The four thousand four hundred peanut gave 

 twenty-two ounces, and the four thousand four hundred sulphur 

 twenty-eight ounces of raw silk. He says he generally obtains 

 one hundred pounds of cocoons from an ounce of eggs. The 

 number of cocoons for the pound varies from two hundred up to 

 four hundred : the peanut variety is said to require three hundred. 

 By another, the peanut is said to take four thousand to make a 

 bushel w^eighing fourteen pounds ; of the Nankin peanut three 

 thousand six hundred, weighing thirteen pounds ; and of the mam- 

 moth sulphur three thousand, weighing ten pounds nine ounces. 

 The thread of the silkworm has been found to be from eight 

 hundred to nine hundred yards on a single cocoon. 



3. The causes of faihcre in raising the silkworm are generally 

 attributed to the want of ventilation, as one writer remarks : " The 

 failures in feeding, that came under my observation, in a propor- 

 tion of ninety-nine to one hundred, have been for the want of suf- 

 ficient ventilation." Another says, " I consider the diseases of 

 silkworms to be produced by vicissitudes in the weather operating 

 upon the moist effluvia from the worms and the litter. The reme- 

 dy is the free circulation of air, and the free use of lime." Again, 

 another observes : " I have seen all the diseases that the silkworm 

 is subject to ; and I believe the nearer we get them to a state of 

 nature the greater the success." Another likewise says : " I am 

 more convinced than ever that water does not hurt the worms. I 

 believe if I had sprinkled my leaves with water this season, when 

 the weather was very dry and hot, I should have saved my 

 worms." And yet another : "I am inclined to think the cause of 

 failure in many, perhaps in most cases, where the multicaulis is 

 used for feeding, arises from using leaves that have not sufficient 

 growth or thickness, and are not ripe. The young and under 

 leaves have not sufficient nutriment, or in other words, not suffi- 

 cient material to produce silk. The worm fed on such leaves 

 passes through its various and wondrous changes, lives the time 

 prescribed by nature for its existence, then either stretches itself 

 out and dies, or winds a thin indifferent cocoon, because it has not 



