122 THE MICROSCOPIST. 



fine pencils, the fat with which insects are plentifully sup- 

 plied. 



Sometimes he put into water the delicate viscera of the 

 insects he had suffocated; and then shaking them gently, he 

 procured himself an opportunity of examining them, especially 

 the air-vessels and trachese, which by this means he could 

 separate from all the other parts. Again, he has frequently 

 made punctures in other insects with a needle, and after 

 squeezing out all their moisture through the holes made in 

 this manner, he filled them with air, by means of slender glass 

 tubes, then dried them in the shade, and anointed them with 

 oil of spike, by which means they retained their proper forms 

 for a long time. He had a singular secret whereby he could 

 preserve the nerves of insects as limber and perspicuous as ever 

 they had been. Some insects he injected with wax instead of 

 air. 



He discovered that the fat of all insects was perfectly solu- 

 ble in oil of turpentine; thus he was enabled to show the 

 viscera plainly, only after this operation he used to cleanse and 

 wash them well and often in water. He frequently spent 

 whole days in thus cleansing a single caterpillar of its fat, in 

 order to discover the true construction of this insect's heart. 



His singular sagacity in stripping off the skin of caterpillars 

 that were on the point of spinning their cones deserves notice. 

 This he effected by letting them drop by their threads into 

 scalding water, and suddenly withdrawing them ; for by this 

 means the epidermis peeled off very easily ; and when this was 

 done, he put them into distilled vinegar and spirit of wine, 

 mixed together in equal proportions, which, by giving a proper 

 firmness to the parts, afforded an opportunity of separating 

 them, with very little trouble, from the exuviae, or skins, with- 

 out any danger to the parts ; so that by this contrivance the 



