INTRODUCTION 



Rate of decrease = const, (concentration), 

 which gives the integrated formula 



(concentration) 



= const.! + const. 2 /, 



where t represents the time (after the maximum) that cor- 

 responds to the concentration in the formula. 



For the case with cholera agglutinin produced by goats, 

 Madsen found n = 3.5, const.j = 0.082 and 0.32 resp., and 

 const. 2 = o.i3 and 0.032 resp. for the first and the second 

 part of the curve represented above. 



As example we give the figures of the second part, 

 together with the results of the calculation. 



In this case the exponent n was rather high, higher than 

 in other cases examined by Madsen. 1 For goats with 

 typhoid agglutinin he found n = 1.3 and #=1.5. This 

 last figure was also found for typhoid agglutinin in the 

 blood of rabbits. The figures of Bomstein for the quan- 

 tity of diphtheria-antitoxin in the blood of dogs and guinea- 



1 Th. Madsen : " The Decrease of Antibodies in the Organism," Festskrift, 

 VIII, Copenhagen, 1902. 



