26 POISONOUS PKOTEINS 



am strongly of the opinion that the bacterial 

 cellular substance as I have prepared and stud- 

 ied it, freed from the extractives soluble in wa- 

 ter, salt solution, alcohol and ether, is practi- 

 cally all nuclear material. 



Some years ago A. B. Macallum by micro- 

 chemical methods showed that nuclei are free 

 from chlorine. His statement is as follows: 

 "Intercellular material and structures, includ- 

 ing the so-called cement substance of von Eech- 

 linghausen are rich in chlorides but normal nu- 

 clei of animal and vegetable cells are absolutely 

 free from them." When my coworkers found 

 no chlorine in the ash of our cellular substance, 

 I thought that this must be due to careless work. 

 I could not believe that with the chlorides, espe- 

 cially sodium chloride, as abundantly distrib- 

 uted as they are, they could be wholly want- 

 ing in this material, but repeated examinations 

 confirmed the first finding. The finding of chlo- 

 rine would not have been a conclusive evidence 

 that the material is not wholly nuclear, but the 

 failure to find any trace of this element I re- 

 gard as most convincing evidence that it is 

 wholly nuclear. Furthermore, Macallum found 

 that the phosphorus and iron in nuclear mate- 

 rial are masked, that is, they cannot be detected 

 without more or less marked disruption of the 



