PRESERVATION. 115 



small pieces, and criisli them quickly between two stones, 

 in a thin piece of paper ; screw up the produce in the lat- 

 ter, with as little exposure to the air as can be avoided, and 

 fix the mass by a pin in a corner of the collecting-box, in 

 which the living insects are to be previously placed ; keep 

 the box closely shut, and in about five minutes every spe- 

 cimen will have expired. It is necessary that the external 

 air should be excluded, otherwise the fumes of prussic acid 

 which are evolved from the crushed leaves, will become too 

 much attenuated to affect the respiratory organs of the in- 

 sects, and the latter will partially revive if too speedily ex- 

 posed to the vivifying influence of a purer atmosphere. I 

 have tried the experiment rather extensively upon insects of 

 various families ; Bomhi and Helophill die very rapidly, in 

 less than two minutes, and without any struggling, as is the 

 case when heat &c. is applied ; and moths, in a state of 

 repose, expire without a single previous motion : conse- 

 quently the process I have recommended is most admirably 

 adapted for killing the larger Lepidoptera almost immedi- 

 ately upon their capture, and thus fine specimens may be 

 conveyed home uninjured. I yesterday killed a gigantic 

 spider in less than half a minute ; and a specimen of He- 

 lops cccruleus, with one or two fresh-captured Philoiithi, 

 at liberty in the box, were also dead when it was opened. 

 I therefore strongly recommend the above process to the 

 notice of the practical entomologist, as being, from its con- 

 venience, better adapted for general application than any 

 hitherto proposed." 



Diptera and Hymenoptera are generally best carried 

 home alive in pill-boxes, vials, or quills, as recommended 

 in the previous chapter ; the same also with very minute 

 moths : Coleoptera of almost every kind may be safely im- 

 mersed in the vial of spirits : Orthoptera and Hemiptera, if 

 large, may be pinned ; if small, put in pill-boxes : dragon- 



