234 
ON  ATROPIA. 
periments  for  the  purpose  of  investigating  the  action  of  caustic 
baryta  in  the  presence  of  water  on  such  substances  as  are  not 
affected  by  it  at  212°  F.,  but  which,  on  being  heated  with  other 
caustic  alkalies,  yield  various  products  of  decomposition.  Pre- 
liminary experiments  have  shown  me  that  glycina  begins  to  be 
decomposed  when  kept  at  a  temperature  of  311°  F.  with  concen- 
trated baryta-water  for  22  hours,  methylamina  being  one  of  the 
products  ;  nicotina  at  338°  F.  yields  a  base,  the  platinum-salt  of 
which  differs  from  the  double  chloride  of  nicotina  and  platinum; 
morphia  and  cinchonia,  at  480° — 505°  F.?  form  small  quantities 
of  volatile  bases.  One  of  the  secondary  products  of  the  reduction 
of  nitrobenzole  by  Bechamp's  method,  is  at  374°  F.,  split  entirely 
into  a  volatile  base  and  an  acid,  of  which  latter  I  have  now  the 
baryta-salt  under  examination. — Annalen  der  Chemie  u.  Pharm.y 
cxxviii,  p.  280—285. 
Note. — Richter  describes  as  atropic  acid  a  substance  closely 
resembling  benzoic  acid,  but  yielding  no  precipitate  with  ferric 
salts.  In  his  method  for  preparing  atropia,  by  setting  the  watery 
infusion  of  the  root  to  ferment  with  yeast,  and  treating  the  clari- 
fied extract  with  ammonia  and  ether,  this  acid  remains  in  combi- 
nation with  the  ammonia,  is  afterwards  combined  with  potassa, 
and  then  separated  by  means  of  sulphuric  acid.  It  is  more  than 
probable  that  the  acids  obtained  by  Richter  and  Pfeiffer,  as  well 
as  by  Kraut,  are  identical. 
The  proneness  of  atropia  to  undergo  a  change  or  decomposition 
when  exposed  to  moisture  or  at  a  higher  temperature,  or  in  con- 
tact with  alkalies,  has  been  noticed  by  Geiger  and  by  Berzelius,  and 
the  experiments  detailed  on  pp.  26 — 28  of  Yol.  xxxv.  of  this 
Journal  may  serve  as  illustrations  of  the  decomposition  which  the 
alkaloid  undergoes  under  such  circumstances  while  still  in  its 
natural  combination.  Berzelius  gave  the  name  tropia  (tropin) 
to  the  amorphous  substance  which  results  when  atropia  is  left 
for  some  time  in  its  mother-liquor.  This  varnish-like  matter,  a 
portion  of  which  only  forms  into  crystals  after  standing  for  some 
time,  retains  the  properties  of  an  alkaloid  only  in  part,  and  re- 
quires much  less  than  the  calculated  quantity  of  iodohydrargyrate 
for  precipitation.    It  possesses  a  peculiar  narcotic  odor,  and  its 
