temperature of the oven must be quite low. If too much heat is applied, great injury is sure to result. Only a careful and expert operator should resort to the use of the oven, a temperature above 120°F. being sure to work mischief. [Illustration FIG. 57.--Setting-board with moth expanded upon it (Riley).] [Illustration FIG. 58.--Butterfly pinned on board, showing method of holding up body and pinning down antennæ.] [Illustration FIG. 59.--Drying-box: _a_, setting-board partly pulled out; _b_, T-shaped strip working in groove on setting-board; _c_, front door, sliding down by tongue, _d_, working in a groove at side in front.] _Relaxing Specimens._--When butterflies or moths have been put up in papers or mounted on pins without having their wings expanded and set it becomes necessary, before setting them, to relax them. This may be accomplished in several ways. If the specimens have been pinned it is best to place them on pieces of sheet-cork on a tray of sand which has been thoroughly moistened and treated with a good dose of carbolic acid. Over all a bell-glass is put. A tight tin box will serve the same purpose, but a broad sheet of bibulous paper should always be put over the box, under the lid, before closing it, and in such a way as to leave the edges of the paper projecting around the edges of the lid. This is done to absorb the moisture which might settle by condensation upon the lid and drop upon the specimens. In a bell-glass the moisture generally trickles down the sides. Earthenware crocks with closely fitting lids are even better than tin boxes, but they must have paper put over them, before closing, in the same way as is done when tin boxes are used. When specimens have been preserved in papers or envelopes these should be opened a little and laid upon damp, carbolized sand under a bell-glass or in a closed receptacle of some kind. Papered specimens may also be placed in their envelopes between clean towels, which have been moistened in water to which a little carbolic acid has been added. The towels should be wrung out quite dry before using them. The method of placing between towels should never be used in the case of very small and delicate species and those which are blue or green in color. Great care must be exercised not to allow the insects to become soaked or unduly wet. This ruins them. They should, however, be damp enough to allow the wings and other organs to be freely moved. When the insects have been relaxed they may be pinned and expanded on setting-boards like freshly caught specimens. It is well in setting the wings of relaxed specimens, after having thrust the pin through the body, to take a small forceps and, seizing the wings just where they join the body, gently move them so as to open them and make their movement easy before pinning them upon the setting-board. The skilful manipulator in this way quickly ascertains whether they have been sufficiently relaxed to admit of their being readily set.