22 Spirazines 



amino acid molecules could be possessed by both 

 ends alike. The fact that the physiological effects 

 of different substances when injected into the 

 blood stream are due almost entirely to the posi- 

 tive kations seems to indicate that assimilation 

 takes place at the acid carboxyl ends, although the 

 acid character of the chemically active portions of 

 living matter may also be due to phosphoric acid 

 radicles clinging to the positive amino groups at 

 either end of the spiral, and acting catalytically 

 as intermediaries to facilitate the assimilation of 

 amino acid molecules, just like sulphuric acid acts 

 catalytically to facilitate the combination of alco- 

 hols with organic acids to form esters. The fact 

 that phosphorus occurs principally in the nuclear 

 materials where such assimilation is known to 

 take place, and even there only in comparatively 

 small amounts, seems to indicate that it does not 

 enter permanently into the molecular structure of 

 proteins but is associated only Avith the actively 

 growing portions thereof. 



The successive nitrogen atoms along each side 

 of the spiral will increase the basicity of the ter- 

 minal nitrogen atom, just like the two nitrogen 

 atoms in diazo compounds increase the basicity of 

 each other. Similarly the carbonyl groups along 

 each side of the spiral will increase the acidity of 

 the terminal carbonyl group. We thus have a 



