(152 ) 



which the increase of osmotic concentration often lasts longer than 

 half an hour. For this reason, the experiments in which the leucocytes 

 were exposed to an action of much longer duration, were made 

 with serum containing only 0.1 and 0.2°/ NaCl; higher osmotic 

 concentration does not occur in the bodyr The leucocytes were placed in 

 the serum of increased osmotic concentration for 2, 24 and 48 hours, 

 and then transferred into normal serum. 



The experiment showed that after an exposure of 24 and 48 hours, 

 the phagocy tarian power had been diminished; but an equal decrease 

 of vitality was also observed in phagocytes which had remained for 

 24 and 48 hours respectively in normal serum. This proved that, 

 the prolonged action of serum of increased osmotic concentration 

 had had no permanent injurious effect on the phagocytarian capacity. 



Thus toe may conclude that, in the living body an increase in the 

 osmotic concentration of the blood plasma, as well as a decrease of 

 the same, has a deleterious effect on the phagocytarian poioer, but 

 that the loss may be recovered; for as soon as the osmotic pressure 

 has been restored to the normal, the phagocytes also entirely regain 

 their inherent power. 



If from these experiments we may conjecture, that what we have 

 observed in the phagocytes, will also be applicable to other cells with 

 semipermeable walls, it is reasonable to conclude from the results shown 

 in tables II and III, that the vital functions of the cell are in a large 

 measure influenced by slight oscillations in the osmotic concentration 

 of the environment and consequently of the cells themselves. 



IV. Effect of simple solutions of Salt. 

 1. Solutions of Sodium Chloride. 



Now the question arises whether the loss of vitality described 

 above, must be attributed to the variations of the quantity of water 

 as such, or to the modification in the concentration of one or 

 more of the substances. 



In order to examine this question systematically, we might have 

 alternately reduced the several elements in the diluted serum to 

 their original concentration and then studied the extent of the improve- 

 ment. But as in the mean time it had been clearly demonstrated 

 to us that in a pure solution of Sodium Chloride of 0.9 % the 

 phagocytes take up carbon in equal or almost equal quantities as 

 in normal serum, we decided to abandon this mode of investigation. 



Here we must incidentally remark that, after all that has been said by 



