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cles and that therefore the pheno.nenon remains restricted to an inter- 
change of water between the cells and the surrounding fluid.) 
Conversely it may be concluded that if two isosmotic solutions 
vive the same volume to the blood-corpuscles, the latter are imper- 
meable to these substances”). 
Therefore we have investigated to what extent a certain amount 
of blood-corpuscles in a solution of NaCl 1,2 °/, had the same volume 
as a solution, isosmotic with the former and which contained 0,9 °/, 
NaCl and 0.5 propionate of Na. 
If the volumes were equal then it might be concluded that pro- 
pionate did not penetrate or hardly into the cells. 
The experiments showed that only traces of propionate could have 
penetrated into the blood-corpuscles. 
Consequently Na-propionate acted upon the red blood corpuscles 
like for instance NaBr and othér anorganic Na-salts. 
Now it might be objected that the permeability of the red and 
the white blood-corpuscles need not be alike. As regards this we 
may observe that none of the many researches carried out in this 
direction, have established any difference. 
The agreement goes even so far that the same hyperisotonic salt 
solution causes the same relative decrease in volume in the red and 
in the white blood corpuscles*), And this also applies to the 
hypisotonie one. 
The analogy also appears from the way in which anisotonic salt- 
solutions act upon phagocytosis *). 
We arrive, therefore at the conclusion that 
until now we have discovered three causes which 
may increase phagocytosis. 
1. Traces of a calcium-salt; there can be hardly any doubt but 
here we have to do with an action of Ca on the cell-protoplasm. 
It has not been verified as yet whether the Ca also acts upon the 
surface. 
2. kat-dissolving substances such as iodoform, chloroform, chloral, 
(TREE, etc. When applied in homoiopathic quantities (e.g. Chlo- 
1) Per fectly equal when the isosmotie solutions are isotonic. Hedin, Priicer’s 
Archiy 60, 198, p. 300 
2) Only urea, as appears from investigations by Gruns and myself, makes an 
exception. 
3) Hampurcer. Archiv, f. (Anat u.) Physiol. 1898 S. 317; Osmot. Druck u. 
lonenlehre L S. 337, 
4) Hampurcer and Hexa. Biochem. Zeitschr. 7, 1907, 102. Further HAMBURGER, 
Physik. Chem. Unters. über Phagocyten u. s. w. Wiesbaden, J. F. Beramann. 1912, 
