104 PREPARATION AND MOUNTING 



any cleaning process, as they are quite free from animal 

 matter. 



In the former chapter were noticed those insects or parts 

 of them whbh are usually mounted dry. When they are 

 large and too opaque to admit of the dry treatment, they 

 must be preserved in Canada balsam or fluid. The first of 

 these may now be considered. 



It may be here mentioned, that with these objects much 

 heat must not be employed, as it would in some instances 

 give rise to a cloudiness, and almost invariably injure them. 



In killing the insect it is necessary not to rub or break 

 any part of it. This may be performed by placing it in a 

 small box half filled with fragments of fresh laurel-leaves, 

 by immersion in turpentine or strong spirit, as also in solu- 

 tions of various poisonous salts. After which it may be 

 preserved for some time in turpentine or other preservative 

 liquid (Chapter Y.) until required. As an assistance to the 

 student, I believe that I can do no better than give him the 

 plan pursued by my friend Mr. Hepworth, whose specimens 

 are in every way satisfactory; but when his method is used, 

 the insects must not have been placed in turpentine for 

 preservation : 



" After destroying the insects in chloroform or sulphuric 

 ether (methylated being cheaper), wash them thoroughly in 

 a wide-necked bottle, half-filled, with two or three waters; 

 the delicate ones requiring great care. Then immerse them 

 in liquid potash (or Brandish's solution, which is stronger 

 than the usual preparation), and let them remain a longer 

 or shorter time according to their texture. When ready to 

 remove, put one by one into a small saucer of clear water, 

 and with a camel-hair pencil in each hand press them flat 

 to the bottom, holding the head and thorax with the left- 

 hand brush, and applying pressure with the other from above, 

 downwards, giving the brush a rolling motion, which gene- 

 rally expels the contents of the abdomen from the thorax. 

 A minute roller of pith or cork might be used instead of the 

 brush. In larger objects, use the end of the finger to flatten 



