H. MORLAND ON MOUNTING OPAQUE OBJECTS WITH BEES-WAX. 197 



it is not heated to any extent, in proof of which I always hold the 

 slip in my fingers when warming it. 



"Whilst melting the wax I sometimes find it advisable to stir 

 it on the slip so as to evenly distribute any colom-ing matter 

 employed ; it is always a good plan to lift out with a penknife the 

 last portion of wax melted in the cell, as otherwise there will occa- 

 sionally be left a sort of soil spot on the surface of the wax. 



Having prepared my cells, which ought to be done only at the 

 last moment, so as to ensure perfect freedom from dust, I then place 

 the object or objects in the same. When this has been done to my 

 satisfaction, I proceed to the fixing, which is efi'ected, not by means 

 of any cement, turpentine or benzole, but merely by placing the slide 

 upon a block of iron, heated to about 140° Faht. ; this gradually 

 softens the wax and fixes the object ; if, however, the object be 

 large, it may require to be pressed slightly into the wax, whilst the 

 same is still soft. 



Immediately the object is fixed, I cool the slide on a cold surface; 

 when cold, to test the fixing, 1 reverse the slide and. rap it on a table 

 or otiier substance. 



I fix on the covers by soldering them down with wax, using a 

 piece of brass wire, about \ inch thick, beaten out at one end, as a 

 soldering " bit." The slides I afterwards finish off with white 

 cement, &c., in the ordinary manner. 



Each method of mounting has its own advantages. I claim the 

 following for the present plan : — 



1st. A particularly clean and uniform surface free from dust, the 

 cell being prepared only at the last moment. 



2nd. Provided the object be dry, perfect freedom from damp, heat 

 being applied throughout the whole process. 



3rd. The objects appear, even under the microscope, to be merely 

 laid on the surface of the wax ; there is no danger of a *' wall " 

 ever appearing round the object if the cover has been hermetically 

 sealed with the wax. I may here mention that this objectionable 

 ''wall" round an object is generally caused either by the back- 

 ground not being sufficiently dry or by the vapour of the solvents 

 of the cements used for fixing down the covering-glass passing under 

 it into the cell, and re-dissolving the background ; a good plan to 

 meet this latter contingency is to employ a background having a 

 solvent different to the cement used for fixing down the cover. 



In arranging a number of objects in one of these wax cells, I 



