148 



HARDWICKE'S SCIENCE-GOSSIP. 



under side, except at tlie trouble of extra manipula- 

 tion in floating off and reversing, and that the gum 

 used clogs the smaller portions of the insect that 

 come in contact with it. Specimens larger than 

 those mentioned should be pinned through the 

 centre of the upper third of the right wing-case, and 

 the limbs extended in position with pins on a setting- 

 board, made of a flat strip of cork glued on deal. 

 Both these and the mounted examples must be left 

 to dry, for a week at least, in the open air; if the 

 boards are fitted to a frame, let them be so placed 

 that the specimens are bottom upwards. Specimens 

 'dry more rapidly in spring and summer tliau at any 

 -other lime, and of course more readily in dry 

 -\Teathcr. 



Tor mounting specimens, five or six small pieces 

 of the finest and most transparent gum tragacantli, 

 or " gum dragon," with the same number of pieces 

 of clear gum arabic, are to be put in a wide-mouthed 

 bottle with about a large wine-glassful of cold 

 water. In a short time (twenty-four hours at most) 

 the gum absorbs the fluid and swells; then add 

 half as much more water, and stir the mixture, wliich, 

 on being left for another twenty-four hours at most, 

 will be ready for use. The gum should be dull white, 

 of even texture, and not quite fluid. Never make a 

 Jarge quantity at one time, or be persuaded to put 

 amjtldng else into it. Card for mounting should be 

 the whitest, smoothest, and best that can be pro- 

 cured. " Four-sheet Bristol board " for large spe- 

 cimens, and three-sheet for ordinary use, are about 

 the proper degrees of thickness. Robersons, of 

 Long Acre, artists' colourmeu, have promised the 

 writer to turn out cardboard of this kind with an 

 extra milling, to insure a good surface. Upon strips 

 of this card, pinned on a setting-board, the insects 

 to be set out are mounted, one at a time, and not 

 too close to each other, each on a separate " dab " 

 of the gum, the limbs being duly set out with a fine 

 pin or needle mounted in a paint-brush stick. A pin 

 with the point very finely turned, so as to form a 

 minute hook, is very useful; and for extremely 

 minute work a " bead-needle " is valuable. The 

 gum-brush should not be used in setting, but one 

 or two very fine-pointed camel's-hair brushes may 

 be found of advantage. Before mounting, reverse 

 the specimen on the blotting-paper, and brush out 

 its limbs as far as practicable M'ith a damp flat 

 brush. Very refractory individuals may require to 

 be gummed on their backs ; as soon as the gum is 

 dry, their limbs can be more easily got into position, 

 and they can then be gently damped off their tem- 

 porary mount, and treated as above. 



A small pair of brass microscope-forceps, ground 

 or cut to a minute point, will often materially assist 

 in getting refractory limbs into position. Erench 

 white liquid glue (not made of shell-lac) is useful 

 for fastening down larger specimens, as it is very 

 strong and dries readily; and with a very small 



quantity of it rows of specimens can quickly and 

 securely be rouglily mounted, in the continental way^ 

 which is preferable in many cases to leaving the 

 insects for a long time in laurel before setting them 

 out. Such specimens can afterwards, if desired, be 

 relaxed by leaving them on damp sand, or in the 

 cyanide- or laurel-bottle, and be then set in the way 

 above indicated. 



Care must be' taken, in setting, not to put the 

 specimen lop-sided on the card, or to distort its 

 segments unnaturally by pulling them out of posi- 

 tion, &c., and not to allow gum to lodge anywhere 

 on the upper surface. It is easy, soon after a spe- 

 cimen is securely mounted, to remove with clean 

 M'ater and brush any superfluous gum. In preparing 

 such insects as are liable to " run up " in drying 

 [e.g. the StapliyVmidce), the abdomen should be duly 

 pulled out by a bead-needle inserted at its apex; 

 and, to prevent the contraction of the internal mus- 

 cles in drying, this part may be held with the 

 liquid glue above mentioned. Usually, by putting 

 these insects as soon as mounted into a box and 

 keeping it closed for a few hours, while the first 

 drying takes place, the proper dimensions of the 

 abdomen may be preserved, and thus the natural 

 facies of the insect retained. The contents of the 

 bodies of very large insects may well be removed, 

 either by the anal orifice, or by an incision on the 

 lower side of the abdomen. The Oil-beetles {Meloe) 

 alone require careful stuffing. This is best done by 

 separating the entire abdomen from the metathorax, 

 beneath the elytra, and close to their point of inser- 

 tion : the body is then easily emptied and washed 

 out, and may be filled with cut-up wool, which 

 packs closely : when gummed on again, the junc- 

 tion is not visible, and the entire insect preserves 

 its M'onderfuUy obese appearance. 



To save time, in mounting many specimens, it is 

 better to merely gum straight on the strip of card 

 as many specimens as can be managed at a sitting. 

 The left side of each of these can then be slightly 

 damped with cletir cold water, 'and its left limbs set 

 out : when all are thus done, the first one will be 

 nearly, if not quite, ready to have its right side 

 treated in like manner ; and so on to the end. Very 

 refractory specimens will sometimes require to be 

 even held down with little braces of card on pins, 

 and to have each liuib damped and set out by a 

 separate operation. The card of large specimens 

 will often curl upwards in drying, owing to the 

 amount of damp ; to counteract this, the loicer face 

 of the card may be washed with a wet brush, just 

 before gumming its surface. 



Before putting insects away, when dry, the indi- 

 vidual specimens should be cut off the strips of card 

 by a straight cut ou each side, one at right angles 

 to the sides in front, and another behind, all (ex- 

 cept the last) close to the tips of the limbs as set 

 out, so that the whole card forms a parallelogram : 



