[ 175 ] Hii' 



Those who have the means of extending these allotted spaces, may do 

 so by some feet; because it is certain, that the more room silkworms 

 are allowed, the better they eat, dige^, breathe, perspire, and rest. 

 The spaces mentioned are sufficient, and present the advantage of fa- 

 cilitating the attendance on the silkworms, and economizing their 

 food. 



It may not be without advantage, exactly to know, what quantity 

 of the mulberry leaf the silkworm consumes in its four first ages. 



For the quantity of food fixed, the following circumstances must be 

 supposed to exist: 



That the silkworms are kept until the first casting or moulting, a.t 

 75° of temperature; between 73° and 75° until the second moulting; 

 between 71° and 73° until the third; and, lastly, between 68° and 71" 

 till the fourth moulting. 



One of the foundations of the art of rearing the silkworm, is to 

 know and determine the various degrees of heat in which, according 

 to their ages, the silkworms are to live. If this precept is not rigidly 

 enforced, nothing can be performed with exactness. 



Tlie writer of an article upon silkworms, inserted in Rosier's 

 " Cour dfJigriculture,'^ Pans, 1801, article Vers a Sole, thus ex- 

 presses himself on this subject: "A sudden change from moderate 

 heat to violent heat, or, in general, from heat to cold, and cold to heat, 

 is highly injurious to silkworms. In their native climate they are not 

 exposed to these vicissitudes, and therefore thrive well, without requi- 

 ring'- all the care we are obliged to bestow on them. With us, on 

 the contrary, the temperature of the atmosphere is so variable, that, 

 without artificial means, we could not fix it in our laboratories for 

 rearino- silkworms. If it should happen to be necessary to hasten the 

 worms, in consequence of the advanced state of the mulberry leaves, 

 it should be done gradually, so that they do not perceive the alteration. " 



All the practical writers, expressly consulted on this subject, are 

 go-reed. It is, moreover, conformable to the well known principle of 

 animal life, (which is always more or less atfected by sudden changes 

 of temperature,) to hatch the worms by the gradual exposure of them 

 to heat. The American cultivator must always, therefore, bear it in 

 mind, if he expects to be fully paid for the trouble, time, and expense 

 bestowed on silkworms. 



The English translator of Dandolo, has indeed inserted a note in 

 this place, containing a passage from the Abbe Sauvage, by which it 

 would seem that young silkworms will bear, with impunity, a much 

 greater heat than the highest degree to which Dandolo limits them, in 

 their early age. Sauvage says, that <'he gave them 100° of heat dur- 

 ing the two first days after hatching, and about 95° during the remain- 

 der of the first and second age, and yet had a most abundant crop.'' 

 But the translator has omitted to say that Sauvage does not recommend 

 the practice. On the contrary, this author expressly says, that " he 

 leaves to his readers to follow as they please the two modes of rearing 

 the worms pointed out by him;" one with a more gentle heat, and 

 the other with an increased degi-ee; and, in two places, (pages 22, 35/ 



