TOXIN SPECTRA. 



197 



Figure 4. 



Figures 1, 2, 3 and 4 are taken from Aschoff's "Ehr- 

 lich's Seitenkettentheorie, etc.," Ztschr. f. Allgem. Physiol., 

 vol. i, 1902. Figure 1 is a toxin spectrum worked out by 

 Madsen. Figures 2, 3 and 4 are spectra representing the 

 changes in qualitative and quantitative structure which a 

 toxin may undergo with age, as described in preceding para- 

 graphs. 



