190 TREATISE UPON THE 



take care to choose rainy weather to make them hatch, and 

 the neighborhood of water to raise them. A much more 

 important remark of P. D'Incarville is, that they can be fed, 

 as he fed them from necessity, when the leaves of the chest- 

 nut-oak fails, on leaves of the common oak. We insist 

 upon this point, because the oak tree of the East is uncom- 

 mon in France, and because it will, perhaps, be possible 

 to find on our common oak trees the true wild caterpillar of 

 China, which gives silk of the second kind. P. D'Incarville 

 says " that it is of the first class, according to the system 

 of M. de Reaumur, like that of thefagara and of the ash ; 

 viz : that it has sixteen legs. The six in front are covered 

 with a sort of shell or scale. Eight are pectoral, and two 

 caudal. The pectoral legs or holders, are furnished with 

 hooks, which assist the insect in climbing. Its greatest 

 singularity is a species of brilliant scales, resembling bur- 

 nished silver. Some have them over each stigmate ; others 

 have fewer or even none at all ; but these last have, upon 

 the tops of the tubercles of the third row, from the spot 

 where the hairs grow, a crown or circle of brilliant gold." 

 The worms of the oak tree are slower in making their 

 cocoons than those of the fagara and ash trees, and they 

 proceed differently. Instead of bending a leaf in the form 

 of a cup, they put two or three together, shut themselves up 

 in them, and there spin their cocoon, which, though larger, 

 is of a very inferior silk ; for it must not be omitted, a great 

 difference exists between the silk of thefagara, ash, and oak 

 trees. That of the first is most valued : the siao-kien is 

 made of it, which is very beautiful and costly. It is, how- 

 ever, but a species of drugget, though very fine, and of 

 admirable use. The tsiao-kien is made of that of the 

 caterpillars of the ash tree, and the ta-kien of the oak. If 

 our merchants wish to buy at Canton these three species 



