BLOOD SMEARS 



2OO 



edge of the advancing slide. An angle less than 45 makes a thinner 

 film; one greater, a thicker film. 



Instead of a slide a square cover-glass may be used and if the edge be smooth it 

 makes a more satisfactory spreader than the slide. 



Instead of the Daniels method some prefer to take up the drop of blood on the 

 slide on which the smear is to be made, about Y 2 inch from the end. Then apply 

 the spreader slide and so soon as the drop runs along the end of the spreader slide 

 proceed as above described. 





FIG. 54. Blood technic. i, 2, 3, Method for making blood smear on slide; 4, 

 U tube for resting slides while staining; 5, slide showing grease pencil marking, 

 marking prevents stain from overflowing; 6, method for drawing apart cover-glasses 

 in making blood smear. 



Of the various methods of making smears by means of cigarette paper, rubber 

 tissue, needles, etc., the best seems to be to take a piece of capillary glass tubing and 

 use this instead of a needle in making the film. There is one advantage about the 

 strip of cigarette paper touched to the drop of blood and drawn out along the slide 

 or cover-glass, and that is that it is almost impossible not to make a working prepara- 

 tion by this method. 



In the making of smears the chief points are to make the smears as 

 soon after taking the blood as possible and to have slides and cover- 

 glasses scrupulously clean. It is well to flame all slides and cover- 

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