222 [Octobei-, 



abandon the use of tragacantli altogether, they could sometimes use 

 it much more sparingly, so that insects carded with it do not appear 

 buried in a pulpy mess when placed for a short time in the relaxing 

 box. I use gum arabic, mixed with a little loaf sugar to give con- 

 sistency and prevent cracking, and an infinitesimal quantity of carbolic 

 acid (mixed with a small amount of spirit) to keep it from turning 

 mouldy. It should be made of such a consistence that it will just 

 pour from the bottle. A preparation of this kind has been used by 

 Dr. Sharp and myself for years, and we are quite satisfied with it. 

 Even if tragaeanth be used, a stronger gum is often required for the 

 bodies of many Sisteridce, Stnphijlinidce, &c., and this latter might 

 just as well be used for the legs and antennse as well. The objection, 

 of course, to many is that the gum tragaeanth, no matter how much 

 is used, is invisible when dry, whereas the preparation of gum arabic 

 leaves a conspicuous mark on the card. But this by no means follows, 

 as with a brush and a little cold water, or better still the mouth, the 

 superfluous portion of it can be washed away at the time. Moreover, 

 the card does not discolour so rapidly as with tragaeanth, for the gum 

 placed under the femora and tibiae is very often quite unnecessary. 

 If the gum arabic is put on in streaks with a brush or piece of fine 

 wire, and the body placed on this for a few moments, the antennse and 

 legs can then be extended if required and gummed down separately. 

 It is often much easier, too, to mount many wiry-legged beetles in this 

 way than with tragaeanth. For floating oif specimens carded with 

 tragaeanth the best method is to place them for a few hours in a very 

 slightly damped relaxing-box (instead of immersing in water, as is 

 usually done), and they can then be lifted off the card before the 

 gum has developed its objectionable property of absorbing moisture 

 to an indefinite extent. 



Dr. Sharp's recipe for the preparation of gum arabic, known as 

 Leprieur's gum, is as follows: — best gum arabic 60 parts, loaf sugar 

 30 parts, sti'ong spirits of wine 8 parts, and purified carbolic acid 2 

 parts. Dissolve the gum and the sugar separately in as little water 

 as possible, and then mix thoroughly together. Dissolve the carbolic 

 acid in the spirit and add it drop by drop to the larger mixture, 

 stirring thoroughly while doing so. 



Unfortunately, none of our dealers sell a preparation of the 

 kind described, or perhaps some of the rising generation might be 

 tempted to buy it. 



Horsell, Woking : 



September Zrd, 1896. 



