MOUNTING OF MICROSCOPIC OBJECTS. 21 



These directions for mounting in balsam with cells of varying 

 depths, and made of sheet wax, are identically the same as though 

 we were using those of glass, metal or other substances. Further, 

 if our specimen, (instead of being dry, as were the supposed For- 

 aminifera,) has been carried through the preliminary stages of alcohol 

 and oil of cloves, it may be transferred directly from the latter, or 

 from benzole, care being taken merely to drain off all superfluity of 

 either, and to avoid air bubbles in the immersion. Whole insects, 

 large as blow flies, maybe thus mounted, without flattening or alter 

 ation in shape. Directions for so doing and for rendering them 

 sufficiently transparent may be given in a future paper. 



Even the simple wax cell may be beyond the immediate reach 

 of many workers, who may still find a necessity for employing some 

 substitute to prevent the crushing of a delicate object; or to hold the 

 cover parallel over a specimen too thick for the ordinary mode of 

 balsam mounting. For such, the following very simple contrivance 

 can be made to answer a most useful purpose, and at the same time 

 make a very neat appearance. Prepare a number of slips of paper 

 and card-board of various thicknesses, by gumming upon one side. 

 They may be placed in a convenient box for use when required. 

 Selecting a slip slightly thicker than the object we desire to mount, 

 we will proceed to cut four minute squares from it; then placing a 

 cleansed slide upon our mounting plate will stick these squares 

 thereon, at equal distances from the centre. These distances will, 

 of course, be regulated by the size of our object and the diameter 

 of the covering glass, as the latter must cover all the squares when 

 laid in position. The gum is to be moistened, of course, to attach 

 the squares to the slide, and when they are in proper position, the 

 whole must be warmed sufficiently to drive off all moisture, which 

 would otherwise cause a milky appearance in the balsam. A drop 

 of the latter having been placed in the centre of the slide and the 

 specimen properly arranged therein, a cover is to be warmed and 

 placed upon it according to former directions, pressing the same 

 down gently with the forceps until it rests equally upon all four of 

 the squares of paper or card-board. Should the object be decen- 

 tered during this operation, it may be pushed back into position by 

 a flattened needle introduced between the slide and the cover. This 

 useful little tool can be readily made by drawing the temper from a 

 large needle and hammering it out flat upon an anvil or any smooth 



