ADDITIONS. 393 



Place the gelatine with the water in a porcelain cap- 

 sule, heat the mixture in a small water-bath over a 

 Bunsen burner, until the gelatine is dissolved, stirring 

 the while and taking care that the gelatine does not 

 stick to the capsule. The water should not be 

 allowed to boil, or at any rate for a short time 

 only. To the hot solution add the glycerine and a 

 drop or two of a strong alcoholic solution of thymol. 

 If necessary cool the mixture to about 40 C., add 

 the beaten up white of an egg and well mix. Then 

 heat as before to about 90 C. stirring continuously. 

 Filter through a hot water filter. 



The gelatine may be left for a day in the cold water to swell up, 

 then dissolved by warming to about 40 C. The glycerine, 

 warmed to about the same temperature, is added. Then 

 proceed as above. 



To mount a section in glycerine jelly, place a small 

 bottle containing glycerine-jelly in a warm chamber. 

 Remove the section from water to a slide, sop up 

 the excess of water, and let fall on it a drop of the 

 melted glycerine-jelly. Place the slide and a cover- 

 slip in the warm chamber for a minute or two, if the 

 section rises to the top of the fluid press it down 

 with a needle so that it lies on the glass. Then 

 cover with the warm cover-slip. 



If a warm chamber is not at hand melt the glycerine- 

 jelly in the flame of a Bunsen burner, warm a slide 

 in the flame and place a drop of the melted jelly on 

 it. With a needle transfer a section to the jelly, 

 and spread it out flat on the glass. Pass a cover- 

 slip through the flame, and cover the section. 



Before surrounding with Canada balsam or other 

 cement the specimen should be examined with a 



