16 



CHEMICAL AGENTS AND PROTOPLASM 



[Ch. I 



Diamid, or hydrazin (HjN — NHj) in the form of neutral 

 solutions of the sulphate is a rapid poison. A solution of — 



0.01 % kills various alga species in 1 to 2 days. 



0.02% is injurious to bacteria. 



0.05% kills various -water animals within 12 hours. (Loew, '93.) 



Phenylhydrazin 

 solution of — 



H / 



is more powerful. A 



0.0067% kills Infusoria and algse within 18 hours. 



0.05% prevents the development of bacteria and mucors. 



As free ammonia (NHg) is a far weaker poison than diamid 

 (HgN — NH,), so anilin (CgHgNHj) is far weaker than phenyl- 

 hydrazin (CgHg . NH . NH2). 



Passing now to the more complex nitrogenous compounds, 

 we find, first, that bodies which possess slight or no poisonous 

 power, and contain tertiary N, can become strong poisons by 

 addition of H and formation of imido-groups (i.e. groups which 

 can be derived from ammonia by the substitution for two H 

 atoms of bivalent acid radicals) ; thus, — 



/CH = CH\ 



pyridin (weaker poison V 



/HC = HC\ 



cr/ > 



CH 



/ \ 



CH3 CH3 



collidin (weak). 



/CH^ - CH^v 



ch/ )nh 



\CH2 - CH/ 



piperidin (stronger poison), 



/H,C - H^Cx 



ch/ )nh 



\CH2 - CH/ 



I 

 CH2 



I 

 CH2 



I 

 CH3 



coniin (violent). 



In the preceding and the two following cases it is seen that, 

 in general, when there is a hydrogen atom of the amid radical 

 (NH2) unreplaced by an alkyl, the substance is poisonous. 



