INSTRUCTIONS FOR COLLECTING IN.SECTS. 171 



"bet. Rome persons, in addition, fasten the cover down by means of 

 brass hooks, to prevent warping, (fig. 7.) Fig. 7. 



The boxes may be made of any well seasoned 

 wood. The bottom of the boxes should be 

 made of wood cut liorizontally from the trunk 

 in plates one-fourth to one-third of an inch 

 thick, and in this case we may use the harder 

 kinds of wood from deciduous leaved trees, 

 except when the rings making the last growth 

 of the year are very hard, or else a very soft wood may be used, such 

 as the partially decayed wood of dead linden or poplar trees ; but the 

 pieces are cut out lengthwise in the ordinary way. In both cases the 

 finest pins can be easily inserted into the wood without risk of injuring 

 their j'oints and hold very well. But in the latter mentioned kind of 

 bottom a fine pin readily takes a wrong direction, and after having 

 been taken out it is difficult to insert it again in a perpendicular posi- 

 tion. The use of soft material for lining the bottom of the boxes has 

 been generally abandoned in the best collections. It is only when 

 perfectly tight boxes cannot be procured that the lining is used, and 

 then not so much with reference to the insertion of the pin as to facili- 

 tate the poisoning of the box and to exclude the acari, psoci, and other 

 insects. The best material for this purpose is blotting paper spread 

 over with mercurial ointment, and over this is laid a fine oiled silk of 

 light color. The oiled silk may be faintly ruled with cross lines to 

 facilitate the symmetrical arrangements of the S2)ecimens. If the oiled 

 silk is fine enough it offers no perceptible resistance to the finest pin. 

 But a more serious inconvenience is, that it prevents us from seeing 

 the texture of the wood at the place where the pin is to be inserted, 

 and hence the points of the very fine pins are liable to injury. On 

 this account it is much better to use wooden boxes without any lining, 

 and these when neatly made look well enough. But if it is deemed 

 desirable to still further improve the appearance of the boxes, a sheet 

 of thin paper may be spread over the bottom, provided the texture of 

 the wood is very uniform or very fine pins are not to be used. This 

 paper may be renewed from time to time, and should be fastened by 

 glue and not by paste, which only furnishes a bait for destructive 

 insects. 



If it is deemed advisable to poison the boxes, it is most conveniently 

 done by means ot bits of felt smeared with mercurial ointment, which 

 are fastened in the covers. During the examination of the insects the 

 covers may be set aside, if any injury to the health is apprehended ; 

 but of this there is not the slightest danger. 



In securing the insects in the collection there is one indispensable 

 rule : nothing should touch the bottom. The labels of genera and 

 species, as well as those on the pin, with each specimen, should be as 

 high as possible ; the first being nearly on a level in the specimen. 



The labels are best made of stout paper, as they are then better 

 kept in position on pins of moderate thickness. 



