A'u.  Jour.  Phirm. 
June,  1901. 
}     Developments  in  Organic  Compounds. 
265 
selective  influence  upon  exposed  groups  of  the  molecule,  thereby 
anchoring  the  entire  complex  in  certain  tissues  where  they  break 
up  and  exert  their  action.  This  is  especially  noticeable  through 
changing  terminal  or  exposed  groups  when  the  action  fails  entirely, 
although  the  nucleus  remains  intact, 
The  theory  of  Loew,1  which  aims  to  explain  the  chemical  consti- 
tution of  living  protoplasm,  claims  that  all  substances  which  in 
great  dilution  react  with  aldehyde  or  amido  groups,  are  toxic  to  all 
forms  of  lite,  and  the  greater  the  reactive  ability  of  a  substance  with 
reference  to  these  groups,  the  greater  its  activity  and  toxicity. 
Such  bases  as  hydroxylamine 
N 
H- 
OH 
and  diamid  H2N  —  NH2  which  react  readily  with  aldehydes  and 
ketones  are  active  poisons  for  plants  and  animals.  Phenylhydra- 
zine  (C6H5MH  —  NH2),  which  is  especially  reactive  towards  alde- 
hydes (R  —  CHO),  and  the  Keto  (R  —  CO  —  R)  groups  is  on  the 
same  ground  a  violent  blood  poison. 
Bodies  containing  a  tertiary  nitrogen  and  possessing  slight  or  no 
toxic  properties,  become  very  poisonous  through  reduction  and  for- 
mation of  an  imido  group. 
H. 
H3C 
CH 
H, 
H. 
Ho 
N  N  NH 
Collidin  Pyridin  Pipendin 
Thus  pyridin  is  more  toxic  than  collidin,  and  piperidin  more  than 
either  of  the  others. 
Tetrahydro  quinolin  is  far  more  energetic  than  quinolin,  likewise 
pyrrol 
HC  =  CH 
^  NH  Pyrrol 
;  =  ch 
is  more  poisonous  than  pyridin. 
1  Die  chemische  Energie  der  lebeuden  Zellen. 
