( 107 ) 



It is thus only the fluid contents which produce the expansion and 

 contraction of the cell by hypisotonic and hyperisotonic solutions. 



If this conjecture is correct, then in the amount of expansion and 

 contraction of the cells there must lie a measure for the compara- 

 tive volume of the two ingredients, and the result must then depend 

 to a great extent on the concentration of the salts employed. 



Under this impression we began to effect a number of determi- 

 nations of the volumes of the network-substance in white blood 

 corpuscles. 



The white corpuscles used for this purpose were almost entirely 

 freed from the red by simply leaving the fluid rich in leucocytes 

 which was obtained by the method above described at rest for an 

 hour. The red corpuscles were then precipitated and in the fluid 

 above were only the white. 



Let us discuss tlie first series of experiments somewhat more in 

 detail. Equal quantities of white corpuscles are mixed with Na CI 

 solutions of 0.7, Ü.94 (isotonic with the serum) and 1.5°/o. After 

 centrifugalizing equal quantities of these solutions, the volume of 

 the white corpuscles respectively amounts to 41, 35.5 and 29.5. 

 In order to calculate the volume of the protoplasmatic net by means 

 of these two last figures, we may reason as follows : Suppose p to 

 be the volume of the protoplasm of the network substance, then the 

 volumes of intra-cellular fluid amounts respectively to (35.5 — p) 

 (29.5 — p). Seeing we must take for granted that the percentage of 

 hygroscopic matter in the intra-cellular fluid remains the same, the 

 following equation must hold. 



(35.5—^) 0.94 = (29.5— ^j) 1.5 

 p = \^A 



From the following figures obtained with the NaCl solutions 0.7 

 and l-SVo the equation results 



(41-^j)0.7 = (29.5— iO 1.5 

 p = 1 9.5 



It appears, therefore, that the quantity of protoplasmic network 

 in both cases is nearly equal. 



The mean is 19.45. 



If we now take into consideration that the total volume of the 

 white blood-corpuscles in the solution of 0.94 which is isotonic with 

 serum, amounted to 35.5, we then find a percentage of 



-^^^^^5^X100 = 54.570, 



taken up by the protoplasmic network. 



