103 [ 175 ] 



£d. When the worms are near rising, the air should be kept a's dry 

 ^s possible, that the paper on the wicker may dry when it is wet with 

 fhe moisure of the evacuations; and that the vapor which exhales from 

 the body of the insect, may be absorbed and carried off: the quantity 

 ©f this is very considerable. 



.'k(. Should any of the worms drop off that had risen, they should 

 be taken up, and carried into the apartment where the other later worms 

 were put, to prevent the late worms from weaving in the large labora 

 tory, when the early ones have finished their cocoons. 



4th. When the silkworm has cast out the down which precedes 

 the silk, and it has just begun to wind its cocoon, as the air does no;. 

 then directly strike upon them, the air may be freely admitted now 

 and then. 



5th. When the cocoon has acquired a certain consistency, the labora- 

 tory may be left quite open, without fearing the variations of the at- 

 mosphere. The tissue of the cocoon is so close, that the agitation of 

 the air, far from being detrimental to the silkworms, agrees with them 

 even if it should be colder than the temperature fixes for the labora- 

 tory. 



Mr. Stephenson directs that all diseased and dead worms should be 

 removed immediately, as the first will infect the healthy worms, and 

 the last, by causing a bad smell, would annoy tiiose which are at work 

 in making their cocoons. 



Although it may seem needless to those who inhabit warm climates, 

 ^hat such minute details should have been gone into, yet, as in an ele- 

 mentary work, rules should be laid' down applicable to all cases and to 

 all places, in the art of which it treats — the endeavor has been made to 

 speak of every circumstance that might occur, and to provide for it-,- 

 All the care hitherto recommended, has tended — 



1st. To preserve the silk, contained in the reservoirs of the silk- 

 worms, in a constantly fluid state. 



2d. To keep the skin or surface of the silkworm sufficiently dr)'-., 

 and constantly in the degree of contraction necessary, and without 

 vvhich the silkworm would perish. 



3d. To' prevent the air from ever being corrupt, and which mio-ht 

 make the silkworm ill, ci* suffocate it, at those \'ery periods when it 

 most needs its highest vigor to pour out all the silk it contains. 



If these rules are not observed with exactitude, there is danger of 

 the accidents occurring which it may be useful here to state, 



1st. Too cold or agitated an air, introduced into the laboratory, maj*' 

 instantly harden, more or less, the silky substance of those worms on 

 xvhich it may blow. This substance thus not being fit to pass through 

 tlie silk-spinning tubes, the insect is soon obliged to cease drawing; 

 aut its cocoon, and safiers. Then will many of those worms that are 

 not sufticiently wrapt in the silk, be liable to drop ofi' at any momenl^- 

 and lessen the abundance of cocoons. 



2d- Too damp an atmosphere, preventing the contraction of the 

 skin of the v\^orras, which enables it to evacuate itself, and to exude 

 .lie silk through tho si'k-rli^a^ving; tube:, ctiu^^^s them to ■^.ifTpr^v.-oaken* 



