[103] 



COLLECTING AND PRESERVING INSECTS R1LEY. 



clean the glass, and replace the corks with new cement. From some cause, inexpli- 

 cable to me, a gradual separation takes place of the cork with its cement from the 

 glass, first appearing at the angles of the cork, and its progress indicated by an in- 

 creasing number of iridescent rings which form within until the center is reached, 

 when, if not previously detached, the insect falls with the cork, usually to its injury 

 and that of others beneath it. 



A number of years ago I happened to employ, in attaching a single piece of cork 

 in one of my cases, a cement originally made for other purposes, consisting of six 

 parts of resin, one of wax, and one of Venetian red. Several years thereafter my 

 attention was drawn to this piece by finding it as firmly united as when at first 

 applied, and at the present time (after the lapse of twelve years) it is without the 

 slightest indication of separation. Acting iipon this hint, I have, of late, used this 

 cement in the restoration of a number of my cases, and with the most satisfactory 

 results. It is important that the cement, when used, should be heated (by a spirit 

 lamp or gas flame) to as high a degree as it will bear without burning. An amount 

 sufficient to cover the bottom of the small, flat metal vessel containing it to the 

 depth of an eighth of an inch will suffice ami prevent the cork from taking up more 

 than its requisite quantity. It should be occasionally stirred to prevent the precip- 

 itation of its heavier portions. The cork may be conveniently dipped by the aid of 

 a needle inserted in a handle, when, as quickly as possible, it should be transferred 

 to the glass, for the degree of adhesion seems to depend upon the degree of fluidity 

 of the cement. From some experiments made by me, after the corks had beeii at- 

 tached as above, in heating the entire glass to such a degree as thoroughly to melt 

 the cement until it spreads outward from beneath the weight of the cork, and then 

 permitted to cool the glass meanwhile held horizontally, that the corks might not 

 be displaced the results appear to indicate that the above cement, applied in this 

 manner on glass properly cleaned, will prove a permanent one. It is scarcely neces- 

 sary to state that this method is not available where the glass has been bound as 

 above. 



Preparatory to corking the glass for the specimens assigned to it, the spaces re- 

 quired for them are to be ascertained by arranging them in order on a cork surface 

 or otherwise. On a sheet of paper of the size of the glass, perpendicular lines, of the 

 number of the rows and at their proper distances, are to be drawn, and cross lines 

 equal in number to the insects contained in the rows. The distances of these lines 

 will be uniform, unless smaller specimens are to occupy some portion of the case, 

 when they may be graduated to the required proportion. With the sheet ruled iu 

 this manner and placed beneath the glass, the points where the corks are to be ap- 

 plied are indicated by the intersections of the lines. The sheet, marked with the 

 family of the insects for which it was used and with the numbers designating its 

 divisions, may be laid aside for future use in the preparation of other cases for which 

 it may be suitable. In a series of unbound cases in my collection, in which the 

 glasses measure 11 by 14 inches, I have used for my Lepidoptera and laid aside the 

 following scales, the citation of which will also serve to show the capacity of the cases : 

 3 by 8, Catocalas ; 2 by 7 and 3 by 9, Sphingidae ; 4 by 11 to 4 by 14, Bombycidse ; 5 by 

 13 to 6 by 16, Noctuidse; 8 by 16 and 8 by 20, Lycsenidse and Tortricidae. 



The unbound cases above referred to are inexpensive frames, made by myself, of 

 quarter-inch white wood or pine, the corners mitered, glued, and nailed with three- 

 quarter inch brads, lined within with white paper (better with tin foil), and cov- 

 ered without with stout manila paper. The glasses are cut of the size of the frame, 

 and when placed in position thereon are appressed closely to it by laying upon them, 

 near each corner, a heavy weight, and strips of an enameled green paper, cut to the 

 width of 1 inch, are pasted over their edges, extending a little beyond the thickness 

 of the frame, and brought downward over the outside of the frame. On its back 

 two gum labels, indicating the insects inclosed, are placed at uniform heights (7 and 

 12 inches), when, if all has been neatly done, they present a tasteful appearance 

 upon a shelf. When there is reason to believe that the case will need to be opened 



