NATURAL SCIENCES OF PHILADELPHIA. 525 



The following remarks by Dr. Stewardson, on the Ailanthus Silk 

 Worm, are here introduced, having been accidentally omitted in their 

 proper place : 



At a meeting of the Academy, held March 5th, Dr. Stewardson called the 

 attention of the members to the subject of the recent introduction of the Ailan- 

 thus Silk Worm into France, aDd its probable adaptation to our own country. 

 Having been much interested in the short notices which he had met with in the 

 French journals, he mentioned the subject to his friend, G. Roberts Smith, of 

 this citv, who kindly obtained for him from Paris a case containing specimens 

 of this' new silk worm (Bombyx cynthia), of its cocoon, and of the silk ob- 

 tained from them, in the several states of crude silk, thread and woven cloth. 

 These specimens were exhibited for the inspection of the members. In the 

 month of June, through the kindness of the same gentleman, eggs of this 

 Bombyx were received from Paris. The first lot entirely failed, most of the 

 eggs having hatched before reaching their destinatiou. From a second im- 

 portation, which arrived a few days subsequently, Mr. Evans, an intelligent 

 manufacturer in the neighborhood of Philadelphia, who warmly interested him- 

 self in Dr. Stewardson's views of introducing the cultivation of this silk in our 

 country, succeeded in raising a few worms, which formed their cocoous in July. 

 Towards the middle of August the butterflys made their appearance, and the 

 eggs laid by them hatched their worms from the 30th of August to the 3d of 

 September. " A part of these worms were placed by Mr. Evans upon a copse of 

 Ailanthus in the neighborhood of his house. Another portion were placed by 

 Dr. Stewardson upon a large Ailanthus tree in a private garden iu Philadelphia. 

 The remainder were fed by Dr. S. in a room at his own house. Those placed 

 in the open air were exposed to violent rains and wind, but without injury. 

 Nearly all those placed upon the tree in the city came to maturity and spun their 

 cocoons, about eighty in number. Of those placed in the open air by Mr. 

 Evans, many were destroyed by birds, but in other respects the success was 

 perfect. About forty cocoons were obtained by Dr. S. from the worms raised 

 at his house. A specimen of one of the latter, feeding upon the leaf of the 

 Ailanthus, and on the eve of forming its cocoon, was exhibited to the members 

 of the Academy, by Dr. Stewardson, at their meeting, held October l3t, at 

 which time he gave a short history of his experiments and their results. 



The Ailanthus Silk Worm, brought from China to Turin, in 1857, was intro- 

 duced into France by M. Guerin-Meneville, in 1858, and already the results of 

 its cultivation have been so encouraging, that but little doubt is now enter- 

 tained that the production of this silk will soon become an extensive branch of 

 industry in that country. 



From a statement recently made to the French Academy, by M. Guerin-Mene- 

 ville, it appears that the cocoons, which at first had to be carded, have been 

 successfully unwound, but by what process he does not mention. This last 

 discovery adds most materially to the value of this silk, and the ease with 

 which the Ailanthus can be cultivated upon the poorest soils, together with 

 the comparatively small amount of labor required in raising the worms, which, 

 when a few days old, are placed upon hedges in the open air, and require 

 scarcely any further attention, render this culture particularly worthy of atten- 

 tion in this country. The experiments of Dr. Stewardson convince him that 

 our climate is well adapted to raising this worm, and that in this latitude two 

 crops can be obtained in a season. Having succeeded in raising upwards of 

 one hundred cocoons, he hopes, with the assistance of any gentlemen who may 

 feel an interest in the subject, during the coming season, to continue the ex- 

 periments upon this interesting subject on a more extensive scale. 



1861.] 



