MOUNTING OF MICROSCOPIC OBJECTS. 29 



quantities as wanted, since it will not keeo. It is tough and very 

 tenacious, and does not dry too quickly, excellent qualities in a 

 cement for such purposes. Use only a sufficient quantity to attach 

 the specimen firmly; any superfluity makes an unsightly blotch in 

 the mount. The cleansed glass cover is now to be cemented on, 

 with the same paste, when we are ready for the finishing. 



The best colors for the covering papers are a bright canary for 

 the black, and a red with gold bronze figures for the front, and 

 these are the kind usually found on sale at the opticians.* The 

 back should be pasted on the under side of the glass slip and 

 turn up over the sides and ends on to the upper side of the same, 

 over which it should extend for an eighth of an inch all around. 

 Then the red and gold front with a y% in. hole previously punched 

 in the centre is to be pasted smoothly over the whole, equi-dis- 

 tant from the edges all around. The labels usually plain white 

 ovals, are to be placed upon each end, when the appearance of 

 the whole mount will be extremely neat and handsome, and the 

 maker's mind need bear no troubles as to its future. Should any 

 appearance of moisture under the cover be seen (which is not at all 

 likely), a slight warming over the lamp will dispel the same, and 

 leave all in pristine brightness. 



Should our specimen be too bulky or thick to be contained 

 within the shallow depths of a cell made of the thickest blotting 

 pad, we must have recourse to the wooden slips, which will be found 

 to form a cell deep enough for any mounting one may ever desire 

 to make. The method of so doing is precisely the same as that fol- 

 lowed with the glass slip, excepting that we must paste a strip of 

 cardboard, covered with the dead black paper, on the under side of 

 the slip to form the bottom of the cell. The slide is to be covered 

 with the papers, and labeled exactly the same as though it were of 

 glass. 



Should the black paper not be readily procurable, a very excel- 

 lent dead black for the bottom of the cell may be made with com- 

 mon lampblack water color, which dries with a dead surface very 

 agreeable and pleasant for mounting foraminifera and similar objects 

 upon. If a little gum arabic be mixed with the water, and the 

 specimen placed upon the surface of the paint whilst still moist, it 

 will be found that the latter will form an excellent cement, as well 

 as background for holding the preparation. 



* The writer regrets that the illustrations intended for this article have not been finished 

 by the engraver in season to appear with the letter press. 



