Staining Blood and Epithelium, etc. 153 



lated spirit, drain away the spirit, and apply a drop of 

 clove-oil to clear the specimen. When clear, drain away 

 as much of the oil as possible, add a drop of Canada 

 balsam, and apply the cover-glass. 



LESSON IV. 



STAINING BLOOD AND EPITHELIUM, TEAS- 



ING-OUT TISSUES, AND MOUNTING IN 



AQUEOUS MEDIA. 

 STAINING WITH PICROCARMINE, GOLD 



CHLORIDE, SILVER NITRATE, AND OSMIC 



ACID. 



Double-staining Nucleated Blood Corpuscles. 



Stain A. — Dissolve 5 grains of eosin in ^ ounce of dis- 

 tilled water and add J ounce of rectified alcohol. 



Stain B. — Dissolve 5 grains of methyl green in an ounce 

 of distilled water. 



Place a drop of frog's blood on a slide, and with the edge 

 of another slide spread it evenly over the centre of the 

 slip ; now put it away out of reach of dust to dry. When 

 quite dry, flood the slide with stain A for three minutes. 

 Then wash with water, and flood the slide with stain B for 

 five minutes. Wash again with water, and allow the 

 slide to dry. Apply a drop or two oi Canada balsam and a 

 cover-glass. 



Blood of Mammals, Non-nucleated Corpuscles. 



Spread a drop of blood on a slide and let it dry for twelve 

 hours, then stain in a strong alcoholic solution of eosin for 

 about five minutes, drain away the eosin, rinse the slide in 

 methylated spirit, let it dry, apply a drop of Canada balsam 

 and the cover-glass. 



Both of the above processes should be carried out during 



