.556 ENTOMOLOGICAL INSTRUMENTS, &C. 



so completely as to cut off all communication with the 

 atmosphere : he next placed the egg under a hen that 

 had been sitting some days, who always kept it at the 

 side of the nest, where it nevertheless derived benefit 

 from her incubation. After the first day its interior 

 was covered with vapour* transpired by the chrysalises. 

 Upon this Reaumur took the egg, and removing the 

 linen plug it soon became dry again: he replaced it 

 under the hen, and no vapour afterwards appeared. In 

 about four days the first butterfly ever hatched under a 

 hen made its appearance ; it would probably have re- 

 quired fourteen under ordinary circumstances. He tried 

 the same experiment with some Dipterous pupae; but the 

 heat was too great for them, and they all perished a . 



Having properly prepared and set your specimens as 

 above directed, the next step, when they have remained 

 a sufficient time to be perfectly dry, is to place them in 

 your cabinet. If you collect foreign insects as well as 

 British, you may either preserve the latter in a separate 

 cabinet, or keep both in the same, distinguishing the in- 

 digenous species by a particular mark. The letter B in 

 red ink, if the pin which transfixes the insect be run 

 through it, or, in the case of Lepidoptera^ placed before 

 the specimen, would be a very distinct and sufficient in- 

 dication of them. The drawers of your cabinets should 

 be about 18 inches square, and from the glass to the 

 corked bottom about an inch and a half in depth : but 

 the larger Dynastida, as Megaso?na Actccon^ &c., will re- 

 quire two inches. The frame of the glass should be rab- 



Reaumur ii. 12 . 



