478 



ADVENTURES IN RADIOISOTOPE RESEARCH 



dSr 



dt 



= a(Sp — Si) 



As already mentioned, a is the coefficient of penetration. In an 

 early stage of the experiment the change of s^ and s^ with time is linear 

 and therefore, as far as we choose such experimental conditions that 

 most of the activity is still to be found in the plasma, we arrive at the 

 average value of s^ during the experiment 



Sp + i — Se 

 P 



and in analogous way on the average 



From which follows, considering that s^ increases linearly with time, 



S, = a(Sp+i — Se — iS,)t. 



We found in our best experiment — = 4 and, as we saw that Sj = 1.8 S^ 



P 

 we conclude that the end value of the specific activity of the corpuscles 



total acid-soluble P when the experiment, as was in our case, is of re- 

 restricted duration, 



Sc=a(Sp -f l.lSjt. 



The value of the penetration coefficient of the phosphate ions into the 

 corpuscles, a magnitude we shall make use of in our later calculations, 

 is given in Table 2. 



Table 2. — Calculation of the Penetbati on-Coefficient 

 OF Phosphate-Ions (a) into Corpuscles 



Sp denotes the specific activity of the total acid-soluble P in the 

 corpuscles; Sp that of the plasma at the end of the experiment 



Time in min. 



f 170 



Rabbit C { ■^,.^^ 



Rabbit G I ^^ 



\ 90 



Average value 



Average value (Rabbit C alone) 



0.0009 

 0.0010 

 0.0014 

 0.0019 

 0.0013 

 0.0010 



