1 7 6 



Or ascertain the average of the red blood cells in the 

 squares counted, and multiply this number by 400,000. 



In case it is desired to count only the white blood cor- 

 puscles, a -J % sol. of glacial acetic acid is used for diluting 

 the blood. This solution bleaches the red cells, and brings 

 out clearly the white corpuscles. 



The blood is diluted only 10 times, using for this pur- 

 pose, the Thoma-Zeiss pipette for counting white corpus- 

 cles. The formula then reads as follows : 



( The number of white ) 

 4000 x d ( 10) x n - l.lood co r p u s c 1 e s [ 



( counted. ) The number of \vhite 



1= blood (tells found in 

 n sq (Number of squares counted). cubic millimeter. 



Or multiply the average number of white corpuscles 

 in each square by 40,000. 



