The Microscope. 89 



strongly flex the first and second joints which will cause the 

 finger below the handkerchief to be filled with blood. 



Previous to this procedure two cover-glasses should be cleaned 

 and be placed in a handy position, and also a cambric needle 

 whose point has been passed momentarily through the flame of 

 an alcohol lamp should be near by. By lightly pricking the 

 finger upon the dorsal surface between the first and second joints 

 a sufficient quantity of blood can be obtained and with scarcely 

 any discomfort. 



Now breathe upon one cover-glass and touch it to the drop of 

 fresh blood, and immediatel}^ breathe upon the other cover-glass 

 and lightly place it upon the first. Just enough moisture should 

 adhere to the cover-glass so that the blood will diff"use itself over 

 the entire surface of both. 



The glasses are now to be carefully separated by a sliding and 

 circular motion, and if properly done there will be two cover- 

 glasses with a single layer of corpuscles over each. Allow them 

 a few moments to dry, then pass two or three times quickly 

 through an alcohol flame and lay them with the coated side up- 

 permost upon a sheet of blotting-paper. With a drop-tube place 

 two or three drops of eosin solution upon each glass, spreading 

 it carefully over the whole surface ; let it it remain five minutes, 

 then wash the glass by waving it in water. The glass is again 

 placed upon the blotting-paper with the coated surface upper- 

 most, and with a hand-bulb, such as dentists use to dry the 

 cavity of the tooth, blow all the water from the surface so that it 

 may be immediately absorbed by the blotting-paper. If the 

 water which adheres to the surface of the cover-glass is not re- 

 moved at once, it will by dissolving and diff'using more of the 

 ■coloring matter, render the whole specimen worthless. Proceed 

 in the same way with anilin blue ; let it remain five minutes ; 

 wash and dry in the same manner, and finally mount in balsam. 



If properly prepared, the specimen will show under a power 

 •of from 600 to 1,000 diameters the red corpuscles colored a 

 heautiful pink, and the white a pale blue or light purple with 

 several dark blue nuclei in each. It affords an easy way to 

 oompare the number of each kind of corpuscles in a given speci- 

 men, because they are so sharply and so beautifully differen- 

 tiated. 



