74 THE MICROSCOPIST. 



but it is not adapted to moist preparations. Colonel 

 Woodward, of Washington, uses a solution of dried or 

 evaporated Canada balsam in chloroform or benzole. 



Dammar Varnish. Dr. Klein and other German his- 

 tologists prefers this to -Canada balsam. Dissolve J to 1 

 ounce of gum Dammar in 1 ounce of turpentine ; also J 

 to 1 ounce *of mastic in 2 ounces of chloroform. Mix and 

 filter. 



Glycerin. This fluid is universally useful to the micros- 

 copist. (See Preparation in Viscid Media, page 65.) Vege- 

 table and animal substances may be preserved in glycerin, 

 but if it is diluted, camphor or creasote must be added 

 to prevent confervoid growths. It is said, however, to 

 dissolve carbonate of lime. 



Gelatin and Glycerin. Soak gelatin in cold water till 

 soft, then melt in warm water, and add an equal quantity 

 of glycerin. 



Gum and Glycerin. Dissolve 1J grains of arsenious 

 acid in 1 ounce of wafer, then 1 ounce of pure gum arabic 

 (without heat), and add 1 ounce of glycerin. 



Deane's Compound. Soak 1 ounce of gelatin in 5 ounces 

 of water till soft ; add 5 ounces of honey at a boiling heat. 

 Boil the mixture, and when cool, add <5 drops of creasote 

 in J ounce of alcohol; filter through flannel. To be used 

 warm. 



Carbolic Acid. 1 : 100 of water is a good preservative. 



Thwaite's Fluid. To 16 parts of distilled water, add 1 

 part of rectified spirit and a few drops of creasote ; stir in 

 a little prepared chalk, and filter. Mix an equal measure 

 of camphor-water, and strain before using. For preserva- 

 tion of algse. 



Solution of Naphtha and Creasote. Mix 3 drachms of 

 creasote with 6 ounces of wood naphtha ; make a thick, 

 smooth paste with prepared chalk, and add gradually, 

 rubbing in a mortar, 64 ounces of water. Add a few 

 lumps of camphor, and let it stand several weeks before 



