1347 
sions') based on them, although this investigator, besides examining 
the total blood, has also tried to investigate bloodplasm. 
The bloodplasm required for our purpose was obtained in the 
way indicated by one of us’). Into a small paraffined tube one 
drops rapidly a small quantity of blood from a punctioned ear-vein 
of a rabbit, one centrifugates for a few moments and takes away 
the topmost fluid plasm with a paraffined glass-pipette. The sugar- 
percentage in this was determined by the latest method of Bane. 
This method was used by us for all sugar-analyses and gave complete 
satisfaction. The double-determinations agreed well. We believe that 
this method, used for a long time already in this laboratory, gives 
reliable results, provided some precautions are observed. These 
precautions were that with each experiment the reduction of a0.1°/, 
glucose-solution was determined and besides it a blind-determination 
in duplicate of all reagents used. This was done especially with a 
view to the varying titre of the thiosulfate-solution. 
Using this method with a number of rabbits we have first of all 
compared the sugar-percentage of the blood-plasm and that of the 
aqueus humour, which was taken at about the same time (difference 
in time 10 minutes at most). 
The chamber-liquid was obtained very easily (after cocain-anaesthesia) by 
inserting a glass capillary tube with ground point into the anterior eye-chamber. 
In general we performed (besides the sugar-determination) also a determination 
of the refraction of plasm and aqueus humour (refractometer of ABBE) to 
obtain an idea of the albumen-percentage of these liquids. 
In Table [ the values found for the sugar-percentage in blood- 
plasm and that in aqueus humour (examined at the same time) are 
laid down. 
In considering this table we must bear in mind the just-mentioned 
fact that the chamber-liquid flows very slowly under normal con- 
ditions, so that we can almost neglect filtration as a factor for 
establishing the equilibrium in the components of the liquids, but 
that this equilibrium is a consequence of the slower process of 
diffusion of the various dissolved components. It follows that (from 
this point of view) we can expect any change (increase or decrease) 
in sugar-percentage of blood-plasm to be followed somewhat more 
slowly by a similar change in the sugar-percentage of the chamber- 
liquid. Where it is known that important changes in blood-sugar- 
percentage may take place in a very short time, there may be 
1) We shall return to these conclusions in detail later on. 
ACS GREVELD."1.C. 
