( 719 ) 
corpuscles, and as these have never shown themselves different 
as to permeability from the white ones it seemed advisable to make 
our investigations on the former. 
Various methods have been chosen for this purpose. In the first 
place red blood corpuscles after being mixed with an isotonic cane 
sugar solution were washed with NaCl solutions, and it was then 
found that Ca had entered into these salt solutions. It might however 
be objected to these experiments that the red blood corpuscles, after 
being washed in a sugar solution, are no longer in a physiological 
condition and on account of that had become permeable to Ca. 
Therefore the experiments were repeated in another way viz. by 
adding slight quantities of substances to the serum oceurring in it 
also under normal conditions. First we added to the blood 0.024°/, 
and 0.012°/, CaCl,. Then serum and blood corpuscles were examined 
as to the amount a Ca they contained, and this was compared with 
the amount of Ca found in serum and blood corpuscles of the blood 
used in our first experiment. If no Ca entered into the blood cor- 
puseles, all the Ca added would be found in the serum. If part of 
the Ca passed into the blood corpuscles, this would be discovered 
as well, and as a test it might be investigated to what extent the 
joint increase of Ca in blood corpuscles and serum corresponded 
with the Ca added. 
We subjoin a table which will need no further explanation. This 
table also contains the result of an experiment answering the question 
whether erythrocytes, having absorbed Ca from a serum containing 
Ca, lose their Ca again when brought back into their normal serum, 
in other words whether blood corpuscles also are ertrameadble to Ca. 
In explanation to this table must be added that the Ca determina- 
tions have been made by burning the dried masses and extracting 
the ashes with dil. HCl and adding alcohol and H, SO, to the clear 
filtrate, Ca being thus precipitated as Ca SO,. Finally we must 
add that in these experiments 80 cem. of cow’s blood were used 
consisting of 32.4 eem. blood corpuscles and 47.6 eem. serum. 
(1). 32.4 ce. blood corpuscles of blood mixed with 0.024°/, CaCl, supply 
after being washed with a canesugar solution 0.0458 gr. CaSO,,. 
(2). 32.4 ee. blood corpuscles of blood mixed with 0.024°/, Co ‚Cl, 
supply after being washed with serum and afterwards with a 
canesugar solution … rt 4 2 OOSEL sro Caso... 
3). 32.4 ce. blood eos | oy normal blood supply after Haine 
washed in a canesugar solution . . . 0.0854 gr. CaSO,. 
(4). 32.4 ce. blood corpuscles of blood mixed with 0.012°/, CaCl, 
| supply after being washed in a canesugar solution 0.0898 CasO 
49% 
