158 INSECT MANUFACTURES. 



over the vapour of boiling vinegar, which kills 

 them ; or the cloth in which they are collected 

 may be folded loosely up and dipped in vinegar, 

 which has the same effect. Another method is to 

 boil a quantity of vinegar under the tree where they 

 are collected, and the ascending vapour kills them. 



The particles emitted by these insects are so very 

 corrosive that persons are liable to be violently 

 affected who attempt to gather them with bare hands 

 during the heat of the day. It is also dangerous 

 to be under a tree where a swarm has gathered. 

 Persons who collect them should always wear a 

 mask and gloves. 



After the insects are killed they must be dried ; 

 this is done in the sun or in a heated room, upon 

 tiles covered with cloth or paper. They are moved 

 about from time to time with a stick, or with the 

 hands furnished with gloves. When properly dry 

 they are so light that fifty weigh scarcely a drachm. 



They are packed in boxes or barrels lined with 

 paper and perfectly dry. If damp gets to them they 

 contract a detestable odour, and are unfit for use. 



A portion of our supply of cantharides is from 



