MOUNTING AND PREPARATION OF OBJECTS. 67 



or two and a little gentle agitation they will float off, 

 any that adhere being cautiously displaced with the 

 camel's hair brush. 



When a sufficient number of sections are cut, they 

 are taken from the spirit and water, and placed in the 

 staining solution ; a flat tin spoon having a hole in 

 the centre of its rounded extremity and its handle 

 bent at right angles, will be found useful for this 

 purpose. 



The best staining fluid for all preparations in- 

 tended for microscopical photography is Beale's 

 carmine solution. Klein recommends the following 

 modification, 



Powdered Carmine, 2 grammes, 

 rub up with, a few drops of distilled water and add 



Liquor Ammon. Fort., 4 c.c. 

 Distilled Water, 48 c.c. 



Shake up well and place in a bottle secured with 

 an india rubber or greased cork to prevent evapora- 

 tion . Glass stoppers are useless for this purpose and 

 should only be used for acids. 



When required one drop is added to 10 or 20 of 

 water. If the tissue is very hard or has been kept a 

 long time in Muller's fluid, a stronger solution will 

 be required, and the vessel containing the staining 

 fluid with the sections must be accurately closed, 

 as its penetration depends to a considerable degree 

 on the quantity of ammonia. If however the sec- 

 tions are fresh one drop is sufficient and the greater 

 part of the ammonia should be allowed to evaporate 



p2 



