On the Fluctuations in tlie Number of white Blood Corpuscles etc. 61 



In the first series the pipettes were filled in two lots, one pre- 

 paration being spoilt in the mounting; there was plenty of liquid 

 in the mixing glass. In the second series the pipettes were also 

 filled in lots, the liquid being mixed by blowing air through it. 

 After I had filled the first two pipettes of the second lot, very little 

 liquid was left and I was therefore obliged to let the scum settle 

 and then mix with care. The result is shown in the greatly varying 

 values for the 7th and 8th pipettes. 



The question has not been solved, but it seems clear from the 

 above that the ordinary method of counting suffers from a great 

 difficulty which has not hitherto received attention. How far this 

 source of error can be corrected must be determined by continued 

 investigations. On the other hand, it seems certain that if we always 

 take a definite drop, we can show by this method even small varia- 

 tions in the number of leucocytes; working with a constant blood- 

 mixture the standard deviation barely exceeds 3 °/o of the average. 

 The absolute number of leucocytes in a cubic mm. remains in fact 

 unknown for the time being; but we can determine the variations 

 and it is the variations which are of the greatest interest. 



We know, that the number of leucocytes in a given quantity 

 of blood varies from day to day or in the course of the day and 

 even in samples taken immediately after one another; but the causes 

 of these variations are still far from clear. So much seems certain, 

 however, that the conditions of circulation, action of the heart, 

 blood-pressure, pulse etc., are of considerable importance as the 

 principal links in the chain of causes. 



It is maintained by Hasselbalch and Heyerdahl^ that mental 

 impressions influence the number of leucocytes. They hold, that 

 this "psychiske Leucocytose" is probably due to a simultaneous 

 change in the action of the heart and not to vasomotor changes; it 

 has been proved, namely by experiment, which they themselves 

 have made, that even a very strong dilatation of the dermal capil- 

 laries (light erythema) is without influence on the number of leu- 

 cocytes. In nervous individuals H. & H. have found very high 

 numbers on examination of the first samples of blood taken and 

 then a very distinct decrease in the number of leucocytes on the 

 nervous condition passing away. 



Ellermann and Erlandsen^ who took up the question later, 

 though they do not seem to have been aware of H. & H.'s work, 

 also remark that the first drop of blood very often — especially in 



1 1. с pp. 254—55. 



- Psychiske Forhold som Aarsag til Svingninger i Leucocyttallet. Hospitalstidende 

 No. 13, 1909. p. 406. 



