242 CHAPTER XIX. 



being closed. By the evaporation of the alcohol the liquid 

 gradually increases in density, and after some time the mount 

 may be closed, or the object brought into pure glycerin or 

 glycerin jelly. 



1. CALBERLA'S LIQUID (Zeit. wiss. Zool., xxx, 1878, p. 

 442). Glycerin 1 part, alcohol 2, water 3. 



2. I strongly recommend the following for very delicate 

 objects: Glycerin 1 part, alcohol 1, water 2. 



3. HANTSCH'S LIQUID. Glycerin 1 part, alcohol 3, water 2. 



4. JAGER'S LIQUID (VoGT and YUNG'S Traite d'Anat. comp. 

 prat. } p. 16). Glycerin 1 part, alcohol 1, sea water 10. 



Glycerin Jellies. 



432. Glycerin Jellies have a higher index than pure glycerin, 

 and set hard enough to make luting unnecessary, though it 

 is well to varnish the mount. To use them, you melt a small 

 portion on a slide, introduce the object (previously soaked in 

 water or glycerin), and cover. They seem very plausible, 

 but for delicate work I do not recommend them, and should 

 advise instead either pure glycerin or euparal. 



433. LAWRENCE'S Glycerin Jelly (DAVIES, Preparation and 

 Mounting of Microscopic Objects, p. 84). Soak some gelatin 

 for two or three hours in cold water, pour off the superfluous 

 water, and heat until melted. To each fluid ounce of the 

 gelatin, whilst it is fluid but cool, he adds a fluid drachm of 

 the white of an egg. Boil until the albumen coagulates and 

 the gelatin is quite clear, and to each ounce of the solution 

 add 6 drachms of a mixture composed of 1 part of glycerin 

 to 2 parts of camphor water. 



434. BRANDT'S Glycerin Jelly (Zeit. wiss. H-ik., ii, 1880, p. 

 69). Melted gelatin 1 part, glycerin 1^ parts. The gelatin 

 to be soaked in water and melted as above. After incor- 

 porating the glycerin, filter through spun glass pressed into 

 the lower part of a funnel. He describes a simple arrange- 

 ment for keeping the funnel warm during the filtering (see 

 early editions). Some drops of carbolic acid should be 

 added. 



435. KAISER'S Glycerin Jelly has been given 155, 



