ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 587 



pierced partiilly througli the plide, leaving a " floor " of the wood, 

 with sheets of wax, such as is used for making wax flowers (green 

 and white). 



To mount as an opaque object, say a portion of leaf with a para- 

 sitic fungus on it, cut a square, about an inch across, of the green 

 wax, and lay it over the aperture in the slide ; press it firmly down, 

 and it will line the whole cell smoothly, and leave a margin of wax 

 projecting round the upper surface. Having made sure that the leaf 

 has no foreign matter on it, cut it so as to nicely fit the sunken cell, 

 now lined with wax (if preferred leaving the wax showing all round), 

 and a very slight pressure with the forefinger will ensure its adher- 

 ence to the floor of wax, without in any way damaging the leaf or 

 fungus ; place the covering glass over the wax cell and press it firmly 

 but gently down, then remove with the penknife all superfluous 

 wax close to the edges of the covering glass ; j)lace over this the 

 covering paper, not applying too much moisture round the central 

 aperture, and the slide is complete. 



It will sometimes happen that a slide is bored so deeply that it is 

 necessary for the convenient illumination of the object that some- 

 thing more than one thickness of wax should be placed in the cell, 

 so as to bring the object nearer to the covering glass ; this can be 

 taken advantage of to produce a very pretty eff'ect. Before proceed- 

 ing to line the cell with the wax, place an ordinary wafer in the 

 bottom of it, moistening only the loioer surface, choosing one, say, of a 

 deep red colour ; place over this a square of the white wax, which is 

 always semi-transparent, and the result will be a delicate pink 

 ground, well calculated to show up to advantage many opaque objects ; 

 other coloured wafers will produce at pleasure grounds of different 

 tints, quite destitute of " glare " or " reflection," and soft and pleasing 

 to the eye. 



The advantages of this method, which is not new, except in slight 

 but not unimportant modifications, are the unfailing certainty of the 

 process, its celerity, total independence of turntables and varnishes, 

 the lightness of the slides, the non-liability to breakage (for there is 

 nothing frangible but the covering glass), and last, but not least, the 

 permanence of the preparation. As to Professor Hamilton Smith's 

 objection to wax cells on account of the covering glass becoming 

 covered inside with a dew-like deposit, Mr. Eoper has noticed this 

 occasionally in specimens mounted on glass slides, but very rarely 

 (not perhaps 1 per cent.) when mounted on wooden ones ; and then 

 no doubt the wax was used when too new, sufficient time not having 

 been allowed for its volatile properties to evaporate ; it is probable, 

 too, that the wood itself may absorb the slight moisture which, in the 

 case of the glass, can obtain no other refuge than the covering glass ; 

 at any rate, speaking from his own experience, he has found no 

 inconvenience on this score, after mounting many hundreds of slides, 

 extending over several years. The result of this very simple, quick, 

 and easy process is, that the object is enclosed in a cell at once air- 

 tight and water-tight, the adhesion of the wax to the wood, and the 

 covering glass to the wax, strengthened by the adhesive cover paper, 



