NEUTRALISATION OF SIMPLE POISONS 



201 



purposes of calculation as might have been. A recalcula- 

 tion in accordance with the rules valid in the exact sciences 

 (cf. page 13) gave a neutralisation curve which did not 

 show the presence of " prototoxoid " in the poison No. 471 

 in the experiments of November, 1902. I therefore made 

 a recalculation of all the data relative to the poisons exam- 

 ined by Madsen. For the poison No. 471 I obtained the 

 following results : 



The constant of equilibrium remained unchanged 

 ( = 0.012), in the whole time. No traces of prototoxoids 

 may be detected from the new calculation. This is also 

 the case for two other poisons, A and C, examined previ- 

 ously by Madsen, and in which he supposed large quan- 

 tities of prototoxoid to be present. If prototoxoid had 

 been present in the poison No. 471, it would have been 

 most evident in the later researches (of September, 1903), 

 since it was then rather old. But just in this case the 



