21 



substances between blood-corpuscles and inediiini remains absolutely 

 unaffected by the addition of chloroforin (see p. 1469). 



Yet we found that there are cases when a modification in the 

 nature of the surface, and consequently a modified permeability ??iz^5<; 

 be assumed. 



From considerations which cannot be detailed here, but which 

 are connected with the varying results obtained by Hamburger with 

 intravenous injections of salt mixed with acid, on horse and calf, 

 the following experiments were made. 



I. Ex-perimental modification of the chlorine-interchange 

 under the influence of acids. 



The experiments were carried out with horse's, cow's, and dog's 

 blood. In order to find a criterion for the normal permeability of 

 the blood-corpuscles, it was first investigated how chlorine behaved 

 if part of the serum was replaced by a Na^SO^-solution. It was 

 known that if all the serum of the blood was replaced by an isotonic 

 NajSO^-solution, chlorine passed from the blood-corpuscles into this 

 sulphale-solution: this is an osmotic process, dependent on the nor- 

 mal permeability of the blood-cells. In order not to deviate too far 

 from physiological conditions, only part of the serum was replaced 

 by Na^SO^-solution; then it was investigated if the chlorine-percen- 

 tage of the serum had been changed, owing to chlorine having 

 entered into the blood-corpuscles or having left them. 



In all the experiments, of 15 cm' of blood 1 cm' of serum was 

 replaced by 1 cm' of isotonic or 2 X hypertonic NajSO^-solution. 

 Since part of the serum is replaced by a solution containing no 

 chlorine, the chlorine in the serum must decrease. This decrease, 

 however, can be calculated beforehand from the amount of serum 

 contained in 15 cm' of blood. Supposing for instance, 15 cm' of 

 blood contain 9 cm' of serum, replacing I cm' of serum by the 

 sulphate-solution must, therefore, cause the chlorine of the serum to 

 fall to Yg of the original amount. It appears now that in the above- 

 mentioned kinds of blood, after + 12 7o of the serum has been 

 replaced by ]S1 a.^SO ^-solution, the chlorine in the serum falls just as 

 much as could be calculated beforehand from tlie dilution of the 

 serum with a solution containing no chlorine. 



It ma^' not be concluded from this that under these circumstances 

 no chloj-ine leaves the blood-corpuscles. The addition of the 2 X 

 hypertonic Na^SO^-solution causes the blood-corpusclus to shrink, 

 because water passes from the blood-corpuscles into the serum 



