The Microscope. 283 



to leave too much clove oil on the lifter. Drjang of objects in 

 ovens, etc., seems to me a nuisance, except in cases of mounts 

 without pressure, and even here I do not advocate it. The 

 formula that I use for balsam ma}^ l)e useful, as it is colorless 

 when mounted and is easily made ; otherwise the Palmer Slide 

 Co.'s balsam is the whitest that I have bought of late years, and 

 is a quick drying medium, more so than the one I use. In fact, 

 I am anxious to find some solvent which will evaporate faster, 

 and yet, if possible, at the same time, to avoid much contraction. 

 Obtain a white sample of balsam in liquid form and take by 

 weight in all cases, in a wide-mouthed bottle, balsam, 3 ounces ; 

 turpentine,! ounce; chloroform (pure), 1 ounce; gently turn 

 the bottle several times to mix well and let it stand till free from 

 air bubbles and is thoroughly mixed. Pour out a small quantity 

 at a time in a one dram bottle, and keep it covered with a cork, 

 with a glass rod drawn to a point passed through it, or take a piece 

 of glass rod and heat till soft, and press the two ends together so 

 as to pi'oduce a flange. It is then easily wiped and cleaned with 

 a rag moistened in turpentine. Care is taken to lower the cover 

 very slowly. As a question, may I ask if any one who has been 

 to Europe and returned here with specimens, has noticed how the 

 climate causes great shrinkage to balsam mounts ? As an in- 

 stance, I have mounts of Cole's Studies, and special mounts of 

 his, and I find now that the zinc white has let air pass through 

 and has ruined the mounts ; in many cases I have had to remount 

 them. I may say here that I am not in favor of the usual white 

 zinc cement, and recommend either brown varnish (Ward's, 

 Manchester, Eng.), or Hollis's glue. The last is the best, for ib 

 may be used with immersion lenses, and "it renders ringing un- 

 necessary afterwards, which is a bug bear if you should be in a 

 hurry to examine a specimen, which is often the case in medical 

 work. 



