140 METHODS OP MICROSCOPICAL RESEARCH. 



two days, immerse it in turpentine until it is not 

 only completely permeated therewith and all air 

 removed, but let it remain until it is sufficiently 

 bleached or decolourised in other words, rendered 

 transparent and in order to ensure this result it 

 should be placed in a strong light. Select a cell of 

 the requisite depth, of pure tin or vulcanite, which 

 affix to the centre of a slip with the French liquid 

 glue ; when this is dry, having cleaned the interior 

 of the cell, place within it the insect, and fill the 

 cell with fairly thick balsam until it presents a 

 slightly convex surface above the cell, lay it aside, 

 as previously recommended, under cover for twelve 

 to twenty-four hours, so that all air may escape, put 

 a minute drop of fresh balsam upon the surface of 

 the balsam which fills the cell, and carefully place a 

 cover, slightly warmed, upon it, close the cell by 

 gentle and equable pressure, at once remove, by 

 means of a soft brush and benzol, all balsam which 

 has exuded under the pressure, let the "mount" 

 harden for a day or two, and then apply white zinc 

 cement or asphalt. 



Cells are to be obtained of various sizes, having 

 pure tin caps to fit exactly over them after the 

 cover is applied, and these not only impart great 

 strength and security to the cell, but ensure the 

 neatest possible finish to the mount. Mr. F. Enock, 

 whose exquisite entomological preparations are 

 altogether unrivalled, is to be credited with this 

 admirable device, as well as with various other 

 improvements in the special branch of the art to 

 which he has devoted himself with such singular 

 success. Insects may be mounted "without pres- 

 sure " in suitable cells filled with pure glycerine 



