OIL OF ANISEED CONGELATION MASS. 209 



glycerin ; a cover is put on, and the mount closed with any 

 suitable cement. In process of time the glycerin will per- 

 meate the gelatin and convert it into glycerin jelly; this 

 may be hastened by placing the slide in an oven kept at about 

 20 to 30 C. 



320. Gum- Gelatin Congelation Mass (JACOBS, Amer. Natural., 

 1885, p. 734; Journ. Roy. Hie. Soc., 1885, p. 900). Gum 

 arabic, 5 parts ; gum tragacanth, 1 part ; gelatin, 1 part. 

 Dissolve in enough warm water (containing one sixth of 

 glycerin) to give a mass of the consistency of thin jelly when 

 cold. 



321. White of Egg Congelation Mass (KOLLETT, DenJcschr. math, 

 naturw. KL k. Acad. Wiss. Wien, 1885 ; Zeit. f. wiss. Mik., 1886, p. 92). 

 Small portions of tissue brought in the white of a freshly laid egg on to the- 

 freezing stage, frozen, and cut. The knife must be well cooled. 



322. Oil of Aniseed Congelation Mass (KUHNE, Centralb. /. 

 Bakteriol., xii, 1892, p. 28 ; Journ. Eoy.Mic. Soc., 1892, p. 706). Soak in 

 oil of aniseed for twelve to twenty -four hours, freeze and cut, and remove- 

 the oil from the sections by means of alcohol. 



14 



