49 



see that air is not entering. When the jelly has set, 

 it is advisable to paint over with a layer of some cement 

 or varnish. 



Glycerine- Alcohol. Make seventy per cent, alcohol. 

 Then make up five, ten, and twenty per cent, solutions 

 of glycerine respectively in this. 



To Mount Delicate Objects. - - Fix in the~ five 

 per cent, solution, heated to about 70 C., and 

 then transfer gradually (at intervals of a day) 

 from one solution to another. Allow the twenty per 

 cent, solution to evaporate slowly (in a dry climate) or 

 near the fire in a moist atmosphere. When the 

 object is permeated, remove excess of glycerine and 

 mount in glycerine jelly. This method is suitable for 

 fixing and mounting small worms, e.g., ankylostomes, 

 etc., which would become too transparent in balsam. 



Chlorine for Bleaching. Place a little chlorate 

 of potash in a test tube. Add some hydrochloric acid, 

 and then some water. Place the object (fly, section 

 of madura fungus, etc.) in, until sufficiently bleached. 

 Wash out thoroughly. 



PREPARING AND STAINING WET FILMS* 



1. Expose a slide for two minutes to the vapour 

 of 



Osmic acid, I % I c.c. 



Glacial acetic acid 4 drops. 



2. Take up a drop of the blood on the slide and 

 expose again to the vapour for thirty seconds. 



3. Spread the film and before it can dry expose 

 again to the vapour for fifteen to thirty seconds. 



4. Absolute alcohol, ten minutes. 



*These methods are employed where it is desired to avoid the distortion of 

 structures which arises from drying films. The films are never allowed to become 

 dry at any stage of the process. 



