124 Correspondence of J. Nickles. 



origin the Society of Acclimation has undertaken to examine the cause.of 

 this disease among the silkworms. In this investigation the Society has 

 been ably seconded by M. Guerin Meneville who had made these insects* 

 special study. Not only have they made a thorough study of the Mtiscar- 

 dine and other diseases of the silkworm, but they sought also to acclimate 

 other silkworms, particularly the species which feeds upon other leaYW 

 than those of the mulberry. The following resume of those experimento 

 we find reported in the Bulletin of the Society, " From these researcha 

 it appears that the disease of the silkworm is caused principally by a 

 disease of the mulberry trees, on the leaves of which the silkworm is fed. 

 This disease can be cured by placing the infected eggs for some time iaa 

 box containing a little spirits of turpentine. But this treatment does not 

 prevent the reappearance of the disease upon the worms when they are 

 fed upon the leaves of diseased mulberry trees," 



In reference to the introduction of new species of silkworms, we haw 

 mentioned in previous correspondence the Bombyx cynthia, a silkworm 

 which feeds upon the Ailanthus glandulosa. More than two thousand 

 amateurs are this year engaged in efforts to rear this worm which feeds 

 freely upon the Ailanthus trees ; these experiments have not all resulted 

 satisfactorily, the insect-eating birds have made a war of extermination 

 upon the Bomhyx cynthia. Nevertheless the degree of success is so great 

 that, according to M. Guerin, it is now practicable to carry on with some 

 success experiments on a large scale. 



But the principal difficulty connected with this manufacture arises from 

 the difficulty of separating [reeling] the silk from cocoons of the Bomhp 

 cynthia. This difficulty has at length been overcome by two different 

 methods, one of which was discovered by Madame Vernede of Corneillan, 

 the other by Dr. Forgeraol. « 



The culture of the silkworm which feeds upon the Ricinus (Castor Oil 

 Bean) ought to be abandoned in France on account of the climate. Tin* 

 industry tiourishes only in warm countries where the Kicinus does not 

 freeze in winter; after experiments tried upon an extended scale the cul- 

 ture of this silkworm has proved successful in the Canary Islands, 



While experiments are continued upon a mixed breed between the 

 silkworm of the Ricinus and that which teeds upon the Ailanthus, on tte 

 other hand, experiments are in progress with the silkworm which feed* 

 upon the oak, also upon the Bombyx hesperus in an experiment at Cayenne 

 where Michlez sought to introduce the culture of silk. 



This Bombyx does not succeed in France because it hatches at a season 

 of the year when all vegetation is arrested. The plant upon which tiii^ 

 silkworm feeds in the natural state, bears the name of cafe diable. i»i- 

 chlez discovered that the Ailanthus suited it still better, and that it devel- 

 oped itself perfectly upon this tree. In a package of silkworm eggs ^^d 

 to the Society of Acclimation by the French Consul in Japan, (M. ^ 

 chesne de Bellecourt) Gu6rin Meneville found a new kind of silkvforffl- 

 • - '■ - - ■ - , feeds u-"" 



The silk which ii 



ivhich feed 





