156 BACTERIOLOGICAL DIAGNOSIS. 
degree of dilution. The other is graduated into a 
hundred parts, the graduation being such that when 
20 cubic millimetres of normal blood are diluted with 
water up to the 100 mark the colour of the two tubes 
should be exactly the same. A pipette measuring 20 
c.m. and a dropping bottle (which is to be filled with 
water) are also provided. 
Method of use—Place a few drops of water (preferably, 
but not necessarily, distilled) in the graduated tube. 
(Tiga eta aes | 
ng. 
Fic. 26.—Gowers’ Hzmoglobinometer.. 
Draw the blood in the usual way. Apply the tip of the 
measuring pipette to the drop and suck gently until the 
blood reaches up to the mark. Now put the tip of the 
pipette into the small quantity of water in the bottom 
of the graduated tube and blow out the blood; suck 
water up the pipette until it reaches above the mark 
and blow it out; repeat this process until the blood is 
thoroughly washed out from the tube. 
Place the two tubes side by side on a sheet of white 
paper in front of a well-lighted window which is not 
