ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 583 



take the place of the water in a very few minutes, thence it may be 

 transferred to carbolic acid and boiled in it for fifteen or twenty 

 seconds, when the object will be ready for mounting at once. I use 

 this method for all moist specimens, and find it of great advantage in 

 enabling me to mount them without delay, besides which, the quantity 

 of acid used or spoiled is comparatively small, its place being partially 

 filled by the inexpensive methylated spirit." 



Moisture in Dry Mounts.* — Mr. W. M. Bale adopts the following 

 very simple plan of mounting objects to allow of the circulation of 

 air through the cell. Take an ebonite cell, and if necessary trim the 

 edge neatly with a file, then with a file or knife cut two opposite 

 broad, shallow notches on that side of the cell which is to be under- 

 neath ; then cement the cell to the slide, taking care not to allow the 

 cement to fill the notches, which, being shallow, are quite unnoticed 

 unless looked for. The object may be placed in the cell, and the 

 cover cemented on at leisure. If a bright edge be required to the 

 cell, it is only necessary to paint it with a tbin solution of balsam or 

 dammar, and no varnish ring on the cell is requisite (unless some 

 other colour than black be desired), as the ebonite cell supplies in 

 itself a sufficiently neat finish. Those who are in the habit of using 

 the excellent slides made by glueing perforated wooden slips to strips 

 of card, can easily provide for the circulation of air by making one or 

 two small slits in the card bottom of the cell. 



To obtain the freest circulation of air through the cells it will be 

 advisible to leave the slides in an open rack box till the cement is 

 hardened, rather than to close them up at once in a cabinet. 



Dammar Varnish, f — This being, according to W. Pfitzner, pre- 

 ferable to Canada balsam, he prepares the solution in the following 

 way : — Gum dammar, benzine, and turpentine, are mixed in equal 

 parts, and put in a warm place. As soon as complete solution has 

 taken place, the clear liquid is poured off, and allowed to evaporate 

 until of the required consistency. Dr. M. Flesch J adds that in 

 Wiirzburg, dammar varnish, as used by painters, is generally em- 

 ployed. 



Cleaning Used Slides and Covers. § — Mr. F. Barnard recom- 

 mends the warming of the slide over a spirit-lamp and removing the 

 cover, which is at once to be dropped into a bottle containing methy- 

 lated spirit of wine, to which has been added 25 per cent, of liquor 

 potassae. Then scrape off as much balsam as possible with an old 

 knife, and with a rag wetted with the above mixture clean the slide. 

 Afterwards, a second rag wetted with the same liquid is used if 

 necessary ; and while wet, the slides are dropped into a basin of water. 

 It will then only be necessary to thoroughly wipe them with a clean 

 cloth. Breathing on them will show at once whether they are clean 

 or not. 



* Joum. Micr. Soc. Victoria, i. (1882) pp. 101-3. 



t Morphol. Jahrb., vi. (1880) p. 469. 



j Zool. Jahreaber. Neapel fur 1880, p. 51. 



§ Journ. Micr. Soc. Victoria, i. (1882) pp. 106-7. 



