37 



abdominal transudate; the pH of serum was slightly less than 7,6 

 and that of normal abdominal transudate 7,6. 



When fluids were injected into the abdominal cavity, a pH of 

 7,2 invariably occurred in the exudation after a short time (+ *l^ 

 hour), no matter whether the injected fluid was acid or alkaline 

 beforehand. This was the same for all injected substances, also for 

 strongly buffered fluids, such as serum. Only the interval before a 

 pH of 7,2 is reached, is somewhat longer. This also applied to oil 

 and paraffin-injections, the centrifugalized fluid then presented a 

 pH of 7,2. 



It appears, then, that a difference of pH from 0,3 to 0,4 exists 

 betioeen the blood and the exudation. At the same time it appeared 

 that emigration of polynuclear leukocytes results from the injection 

 of the same fluids. 



There is noiu every reason for correlating the constant occurrence 

 of emigration luiih this constant phenomenon of the changed pH, 

 lühich also always manifests itself, however dijferent the injected fluids 

 may be. 



The question may be asked : in how far this differing H-ion con- 

 centiation may be answerable for the emigration. 1 have endeavoured 

 to solve this [uoblem by maintaining artificially in the injected fluid 

 a pH of 7,6 or a little higher, through the addition of alkali, and 

 comparing the result obtained with a control-animal, in which the 

 injected fluid was left to itself. I found from three such experiments 

 that in the first case no emigration of polynuclear leukocytes ensued, 

 which, however, revealed itself with the control-animal. 



It is evident from these experiments that the degree of acidity is, 

 indeed, the causative factor of the emigration of the polynuclear 

 leukocytes; it being the only factor which has altered in the experi- 

 ments mentioned. 



We now have to go into the question in what manner this esta- 

 blished difference in H-ion concentration with the blood can bring 

 about the emigration. Presumable potential differences between fluids 

 with various H-ion concentration are the first to suggest themselves; 

 such potential difference might well effect a movement of cells in 

 one direction, in casu an emigration. I am analogously reminded 

 here of the well-known cataphoretical phenomejia found i.a. by Höber 

 and his pupils especially in red blood-corpuscles. 



1 thought it desirable by following the example of Höbek to 

 perform cataphoretic experiments with red bloodcorpuscles, with 

 polynuclear leukocytes and with mononuclear leukocytes of the 

 rabbit in order to ascertain whether they behaved differently towards 



