226 S. GREEN ON PREPARING INSECTS FOR THE MICROSCOPE. 



pin out as before and put it into the turpentine bath, where it 

 should remain until it is fit for mounting in balsam. I keep two 

 or three dozen pin points stuck in a piece of cork ready for imme- 

 diate use. They should be about one quarter of an inch long and 

 tolerably fine. In setting ants on the film of Canada balsam I 

 find their jaws will not always remain open. To prevent their 

 closing I sometimes place a small splinter of wood between the 

 points of them, which, if carefully done, keeps them well open. 

 This precaution is not necessary while they are in the turpentine 

 bath. 



I have lately returned from a seven weeks' tour up country, and 

 during that time I visited five localities, spending a few days at 

 each place. I carried with me all that was necessary to prepare 

 insects for mounting, so far as the spirits-of-wine process was con- 

 cerned. I collected all interesting insects that I came across 

 while hunting for objects, and I brought them back to Columbo 

 in little bottles of spirits of wine, with the hardened balsam adher- 

 ing to them. I have since examined them and they appear to 

 have received no damage at all by the shaking they underwent, 

 while my box was being carried about from place to place, over a 

 rough and broken country. I have also mounted a few of them 

 with perfect success. 



If it is desirable to keep insects for any length of time before 

 mounting them in Canada balsam, or if they have to be sent to a 

 distance by post, the preparation of them should be stopped 

 after they have been in spirits of wine on the film of Canada 

 balsam. The film, with the insect on it, can be detached from the 

 piece of glass by cutting the former with the point of a fine needle 

 drawn round the insect. Remove the detached piece of film and 

 place it in a small glass bottle full of clean spirits of wine. The 

 hardened balsam can at any time be dissolved away from the insect 

 by spirits of turpentine. I find that it is sometimes easier to set 

 small insects in position by placing them on their backs upon the 

 film of balsam. Their legs can be arranged in that position with 

 greater facility. 



One of the advantages of the poison bottle is that it kills insects 

 apparently without much inconvenience to themselves. They seem 

 to go to sleep in the cyanide of potassium. 



