998 
of the uranium salt, consequently considerably more than 15 m.Gr. 
which was found by the experiments. 
The same substitution could be carried out with bromide of radium 
solution. ° 
1 capsule of the Allgem. Radiogen Gesellschaft contains + X 10? 
milligrammes of Rabr,. It was dissolved by heating in 100 ee. of 
distilled water, which had been acidified with some HCl. This 
solution having been neutralized with some NaOH sol. containing 
no K, 24 ec. of the fluid obtained was put into 1 litre of RinGEr- 
solution which contained no K. Some glucose having been added, 
the fluid thus obtained could indeed retain 0.03 °/, of glucose. The 
fluid contained 5 > 10 ® mGr. of RBr, per litre, the same quantity 
as that which was found by ZWAARDEMAKER and Feenstra to keep 
up the contractions of the frog’s heart. 
The use of 710° instead of 510 6 mGr of RaBr, per 
litre, causes the retention of glucose to decrease; this is also the 
case when 34 & 10-® is used. 
If the RaBr, had acted in chemical equivalency the quantity of 
it being necessary to replace the 100 mGr. of KCl would have been 
ae X 100 = 259 mGr. of RaBr, per Litre instead of 5 X 10-6 mGr. 
Hence it follows that potassium, uranium and radium affect the 
retentive power of the glomerulus membrane for glucose, in equiradio- 
active doses, and not in chenically equivalent doses. 
Further experiments will probably show that the limits can be 
determined more closely than it has been done here. 
These investigations throw a light upon the uranium-glucosuria, 
which has hitherto not been explained. It is most likely caused by 
a disturbance in the relative percentages of the metal atoms in the 
bloodserum, the” potassium of which has been increased by the 
addition of a metal which is, in a certain sense, related to it (ura- 
nium or radium). 
The fact that glucosuria is caused by the injection of some nitrate 
of uranium is not contradicted by the salutary therapeutic effect of 
uranium in diabetes (Hvenes and West) *); but then it would have 
to be assumed that the potassium percentage had decreased. As to 
this, however, all data are wanting. 
Groningen, January 1917. Physiological Laboratory. 
1) Quoted from CAMMIDGE. Glucosuria and allied conditions. London, EpwARD 
ARNOLD 1913, p. 339, 
