234 STITT. 



which show themselves in the form of more or less uniformly stained 

 blotches, the former leucocytic character of which can not be determined. 

 By checking the percentages obtained by the method I shall describe 

 and those secured by the usual means, I have found that in septic con- 

 ditions these disrupted cells are largely polymorphonuclear, while in 

 such conditions as malaria and dengue they are chiefly transitionals. 



The surgeon of the present day always demands a leucocyte count, 

 and the medical man in the Tropics finds it almost equally necessary in 

 differentiating diseases which show a leucocytosis from those which 

 present a leucopenia. Consequently, a distinct saving of time would 

 result if it were possible to obtain other findings in the same preparation 

 used for ascertaining the number of leucocytes per cubic millimeter. 



By employing the ordinary technique for making a count of the 

 white blood cells, with the exception that I use a diluting fluid made 

 by adding five drops of Giemsa's stain to 5 cubic centimeters of 2 per 

 cent formalin, I also am able quickly and, I am convinced, accurately to 

 make a polymorphonuclear percentage count, or a complete differential 

 count in addition to that of the leucocytes. 



Another advantage is that blood parasites are also perfectly stained, 

 are shown distinctly, and by reason of the larger amount of blood visible 

 in each field, the finding of them is far less tedious than where a stained, 

 dry film is used. 



In preparing the Giemsa stain I use the original method by dissolving 0.08 

 gram Azur II and 0.3 gram Azur II eosin in 25 cubic centimeters of glycerine 

 at 60°C, then adding 25 cubic centimeters of methyl alcohol, allowing the whole 

 to stand overnight and then filtering. 



The ordinary commercial formalin and distilled water are used in preparing the 

 2 per cent formalin solution. 



Better results are obtained when the Giemsa solution is added to the formalin 

 just prior to using. The staining power of the mixed formalin and Giemsa begins 

 to diminish after a few hours, therefore it is better to drop the Giemsa solution 

 from a dropping bottle into the formalin in a watch glass at about the time the 

 blood count is to be made. The best results are secured when the mixing in the 

 pipette bulb is done immediately after taking up the blood and diluent. 



The usual technique in making the hsemocytometer preparation is em- 

 ployed, a Tiirck ruling being used. I count the leucocytes in the' 3 

 upper or lower square millimeters, divide by 3 to obtain an average per 

 square millimeter, multiply by 10 for the content of a cubic millimeter 

 and then by 20 for the dilution. (Blood to 0.5, diluent to 11.) This 

 can be done mentally and requires no calculation on paper. Having 

 counted the leucocytes I again go over the same portion of the ruled 

 surface and determine the polymorphonuclears and estimate the per- 

 centage of these to the total leucocytes. 



It is unnecessary in such counts to have an assistant record the results. 

 Of course, in making a complete differential count it is preferable to have 

 some one tabulate them, or laboriously to do this personally. 



