1260 
it was intimately connected. Neither by centrifugalizing in suitable 
tubes nor by hanging up vertically pieces of ligated cord did we 
succeed in this however in more than a few cases. The strong 
contortions of the most umbilical cords and the consequent twistings 
were the chief reasons for this. Only once up to this did we succeed 
in bringing about in a cord with few contortions, the division and 
comparing the plasma sugar with the quantity of sugar in the 
blood of the cord as a whole and the relative volume of the blood 
corpuscles. The concentration of the sugar in the plasma was found 
to be markedly higher that that of the blood in the cord. 
[t appeared that some of the large veins which are constantly 
found on the surface of the foetal side of the placenta could be 
more easily isolated and then centrifugalized. In these the blood 
remained fluid for a markedly long time. Also in these cases we 
can up to this boast of only one reliable determination for com- 
paring the plasma and the blood as a whole. This however also 
proved to be in favour of the plasma. We have not been able to 
make a sufficient number of determinations by this method to come 
to a conclusion through them whether human bloodeorpuscles are 
permeable or impermeable to sugar. 
We succeeded in doing this in the meantime by another method 
viz the paraffin method; one way of keeping blood uncoagulated 
without adding one of the known substances is by collecting it in 
tubes which have been thoroughly cleaned and then waxed to make 
them perfectly smooth. By using thus small and narrow waxed 
tubes the blood collected in them can by rapid centrifugalization 
be divided into its corpuscular and plasmatic parts which takes 
place without the occurrence of coagulation. In larger tubes coagu- 
lation took place fairly regularly during the process of centrifu- 
galization. The way in which plasma was obtained now was 
very simple. _ 
From a carefully cleaned finger tip in which a deep prick was 
made with a needle, we allowed a few drops of blood to fall into 
two tubes which had been waxed shortly before the experiment. 
These were then rapidly centrifugalized for a period of from one 
to two minutes and the plasma then sucked off by means of a waxed 
pipette and dropped on Bane’s paper. At the same time blood was 
collected for the determination of the total amount of bloodsugar 
and the relative volume of the bloodcorpuscles. 
From a number of these experiments conducted with different 
persons at different times of the day the following results were 
obtained : | 
