676 



Bilt the state of things in the Ringer flnid is still more complicated 

 than in the system CaCl, and NaHCO,, especially because the fluid 

 contains a rather considerable quantity of NaCl. This renders the 

 determination of the cone, of free ions of Ca rather difficult. 



It seems that the equilibrium of the sj'Stem CaCla, NaHCOj and 

 NaCl, so important to life, has hitherto not been studied. We intend 

 to revert to this subject later on. At any rate we have now ohtained 

 a transmission fluid of which, of the 0.1 "/„ of glucose, on an 

 average 0.07 "/„ i-^ retained, and in which automatically that cone, 

 of ions of Ca' sets in ujhich causes ± 0.07 "/o of ^^^^ ^^-1 °/o (>f gl'^' 

 cose to he retained. 



It is this transmission-fluid which has enabled us to obtain a ?<rme 

 free from sugar, which had hitherto been found impossible. Accord- 

 ing to Bang') frogs' blood gives a reduction which corresponds to 

 0.03 — 0.05 7o of glucose. We accordingly found in September a 

 reduction value of 0.04— 0.06 "/o- Now the question was: will the 

 kidney be able to keep back all the sugar from a RiNGER-fluid of 

 the above composition and containing 0.05 "/„ of glucose. The una- 

 nimous result of our experiments proved that this was indeed the 

 case, 



All glucose was likewise retained, even when the RiNGER-fluid con- 

 tained 0.06 "/(, of glucose. 



Now it will be of importance to determine to what pitch hyper- 

 glycaemia can be raised before glycosuria sets in, in other words 

 how much sugar the kidney can bear. This question will be treated 

 in a subsequent paper. 



CONCLUSIONS. 



The fact that by modifying the composition of the RiNGER-fluid the 

 colloid slate of the glomerulus-epithelium can be regulated in such 

 a manner that it either admits or does not admit sugar, seems to 

 us of great importance, for now it has become superfluous to assume 

 as an explanation of physiological glucose-retention, that substances 

 are found in the serum which keep back the glucose in colloid 

 compounds and that the glucose cannot pass through the glomerukis- 

 membrane in that form. That this supposition is no longer necessary 

 will afford satisfaction, after Michaelis and Rona and also Abel by 

 dialysis-experiments and we by ultra-filtration have found that 

 parch men tpaper and ultra-filters of celloidin allow all glucose in the 



1) J. Bang, Der Blutzucker 1913. J. F. Bergmann, Wiesbaden. 



