THE BLOOD. 



25 



CHAPTER I. 



THE BLOOD. 



Preparation 1. A drop of blood may be most 

 conveniently obtained for examination from the fin- 

 ger. It is generally sufficient to give the end of the 

 forefinger of the left hand a smart prick with a clean 

 sewing-needle, in the thin part of the skin adjoining 

 the root of the nail, squeezing firmly with the right 

 hand above the point pricked, to cause a drop to 

 exude. If necessary, the finger may first be con- 

 gested by tying a piece of string tightly round it. 

 As soon as a small drop of blood has been pressed 

 out, take up a previously cleaned cover-glass by one 

 edge with forceps, let the drop come in contact with 

 the lower surface of the glass near the opposite ed;e, 

 so that a little adheres ; and then, letting this edge 

 come first in contact with the upper surface of the 



Fig. 5. 



Glass slide and cover-glass, natural size. 



The figure shows the mode of letting down the cover-glass (with a drop of blood 

 on its under surface) gently ou to the middle of the slide. 



slide near its middle, gradually lower the other 

 edge, which is still held in the forceps, on to the 

 3 



