EXAMINATION AND PRESERVATION MEDIA 223 



GLYCERIN JELLIES 



471. 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. 



Glycerin jelly mounts will last perfectly if properly sealed ; some, 

 now fifty-four years old, and in splendid condition, are in the possession 

 of Mr. G. T. Harris of the Queckett Microscopical Club. 



For preparing objects to nioinit in glycerin or jelly refer to 

 § 1188, p. 600. 



472. 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. 



473. Brandt's Glycerin Jelly {Zeit. wiss. Mik., ii, 1880, p. 69). 

 Melted gelatin 1 part, glycerin \\ parts. The gelatin to be soaked 

 in water and melted as above. After incorporating the glycerin, 

 filter through spun glass pressed into the lower part of a funnel. 

 He describes a simple arrangement for keeping the funnel warm 

 during the filtering (see early editions). Some drops of carbolic 

 acid should be added. 



474. Zwemer's " Glychrogel " Mounting Solution is primarily 

 intended for mounting frozen sections. It is made up as follows : — 



Glycerin . . . . . .20 c.c. 



Gelatin, granulated .... 3 grm. 



Chrome alum . . . . . 0-2 ,, 



Distilled water . . . . .80 c.c. 



Dissolve separately the chrome alum in 30 c.c. of water and the 

 gelatin in 50 c.c. of water, using heat in both cases. Combine the 

 glycerin with the gelatin solution while the latter is still warm 

 and then, while stirring, add the warm chrome alum solution. 

 After thoroughly mixing, filter and add a bit of camphor as a 

 preservative. Keep the bottle well stoppered to prevent evapora- 

 tion. To use, warm the solution in an oven to about 30° to 37° C, 

 when it will flow freely. 



475. Kaiser's Glycerin Jelly has been given § 180. 



476. Squire's Glycerin Jelly (Squire's Methods and Formula', 

 etc., p. 84), Soak 100 grm. of PVcnch gelatin in chloroform 

 water, drain when soft, and dissolve with heat in 750 c.c. of 

 glycerin. Add 400 c.c. of chloroform water with which has 



