RATE OF PENETKATION OF IONS THROUGH THE CAPILLARY WALL 



427 



produced with the active halogens. We are much indebted to Dr. J. C. Jacobsen 

 and Mr. O. N. Lassen for preparing the radioactive substances by making use 

 of the Copenhagen cyclotron. 



About 3 cc. solution containing the radioactive substances of an activity of 

 about 1 microcurie was applied. The salt concentration of these solutions was 



3 4 



Min. 



Fig. 1. Rate of disappearance of various labelled ions from the plasma. 



brought up to a physiological level by adding non-active sodium chloride. The 

 solution was injected into the jugularis of the rabbit and blood samples of about 

 1 cc. were collected at intervals from the carotis. Plasma samples of known weight 

 were dried and their radioactivity was compared by using a Geiger counter. For 

 comparison of the radioactivity of plasma and muscle samples the samples were 

 ashed at about 400° and the plasma ash mixed with non-active muscle ash of the 

 same weight as the corresponding active muscle ash sample. Blood and muscle 

 samples were secured simultaneously from the narcotized rabbit. 



RESULTS 



The results obtained are seen in Tables 1 to 5 and Figs. 1 to 3. The 

 tables contain data on the percentage of the labelled element injected 

 still present in 1 cc. plasma at various intervals. The volume of diluting 

 lluid necessary to bring down the concentration of the substance in- 



