204 EXAMINATION AND PRESERVATION MEDIA. 



it will do if the temperature is only kept up long enough to dissolve the 

 crystals. Filter while hot. The index may be brought up to 1/525 if desired, 

 by evaporating the solution somewhat, or by adding more carbolate. 



384. Barff's Boroglyceride (see Journ. Roy. Mic. Soc., 1882, p. 124). 



385. Glycerin and Alcohol Mixtures. These most useful 

 fluids afford one of the best means of bringing delicate objects 

 gradually from weak into strong glycerin. The object is 

 mounted in a drop of the liquid, and left for a few hours or 

 days, the mount not 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 



Glycerin . . . . . .1 part 



Alcohol . . . . . . 1 



Water 1 



A most valuable examination fluid. 



2. I strongly recommend the following for very delicate 

 objects. 



Glycerin . . . . . .1 part 



Alcohol . . . . . 1 



Water 2 



3. ILENTSCH'S LIQUID 



Glycerin 1 part 



Alcohol 3 



Water 2 



4. JAGER'S LIQUID (quoted from YOGT and YUNG'S Traite 

 d'Anat. comp. prat., p. 16). 



Glycerin 1 part 



Alcohol . . . . . . 1 



Sea- water . . . . . . 10 



386. Deane's Glycerin Jelly (from FRET'S Le Microscope, p. 

 231). 120 grammes glycerin, 60 grammes water, 30 grammes 

 gelatin. Dissolve the gelatin in the water, and add the glycerin. 

 This, and the following glycerin- jellies, must of course be used 

 warm. 



387. Lawrence's Glycerin Jelly (DAVIES, Preparation and 

 Mounting of Microscopic Objects, p. 84). " He takes a quan- 

 tity of Nelson's gelatin, soaks it for two or three hours in cold 



