OBSERVATIONS ON DISSECTING, ETC. 247 



condition. Again, he has frequently made punctures in 

 other insects with a fine needle, and after squeezing out 

 all their moisture through the holes made in this manner, 

 he filled them with air, by means of very slender glass 

 tubes ; then dried them in the shade ; and, last of all, 

 anointed them with oil of spike, in which a little rosin 

 had been dissolved, by which means they retained their 

 proper forms for a long time. He had a singular secret 

 whereby he could so preserve the nerves of insects that 

 they used to continue as limber and perspicuous as ever 

 they had been. 



He used to make a small puncture or incision towards 

 the tail ; and after having gently and with great patience 

 squeezed out all their humours, and great part of their 

 viscera, he then injected them with wax, so as to give 

 and continue to them all the appearance of healthy, 

 vigorous living creatures. He discovered that the fat of 

 all insects was perfectly soluble in oil of turpentine : 

 thus he was enabled to shew 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 cater- 

 pillars that were on the point of spinning their cones, 



account given by Swammerdam is not sufficiently explicit to point out the 

 mode of applying it. 



