51 



Stain for five to twenty minutes, according to the 

 depth of colour of the sections. 



(ii) Methylene blue, or gentian violet. 



(iii) Counterstain, if desired, with watery 

 eosin. P^or the detection of pigment it is well to 

 stain a section faintly with eosin alone. 



5. Pass through alcohol, oil of cloves, to 

 Canada balsam. In hot moist climates, the cold 

 produced by the evaporation of the alcohol 

 causes dew to be deposited upon the slide. When 

 the xylol or oil of cloves is added, this produces a 

 troublesome milkiness and may spoil the section. 

 To avoid this, all excess should be rapidly wiped 

 up after the use of alcohol, and the oil of cloves 

 added as quickly as possible. 



To stain sections with Romanowsky 



A — I, Fix and dehydrate small pieces of tissue, one to 

 two millimetres thick, in absolute alcohol (one to 

 four hours) Xylol, fifteen minutes. Hard para- 

 ffin, twenty minutes 



2, Cut sections as thin as possible. 



3, Stain with the undiluted eosin solution ten to 

 fifteen minutes. Blot off excess, 



4 Stain with the diluted methylene blue solution 

 fifteen to twenty minutes Pour off excess, 



5 . Pass rapidly through 70 per cent alcohol Place 

 at once in water, 



6. Treat with one in four hundred acetic acid 

 momentarily, and place at once in distilled 

 water. F2xamine with a low power, and when 

 the nuclei appear bright red, and the section con- 

 tains but little blue, blot off excess of water. 



7. Allow to dry on the slide 



8. Examine by placing oil on the section without a 

 coverglass. 



