Am'May?i893arm'}  Observations  on  Decomposing  Chloroform.  241 
an  alkali,  and  the  resulting  precipitate  washed  with  warm  water,  it 
is  found  that  after  dissolving  out  with  hot  spirit  the  bulk  of  the 
unchanged  narcotine,  a  portion,  which  is  much  less  soluble,  remains. 
This  residue,  after  complete  purification,  has  been  proved  to  be 
in  every  respect  identical  with  gnoscopine  as  prepared  from  original 
opium  liquids. 
OBSERVATIONS  ON  DECOMPOSING  CHLOROFORM.1 
By  David  Brown,  F.C.S. 
At  the  last  meeting  of  the  British  Pharmaceutical  Conference,  I 
withdrew  the  zinc  iodide  and  starch  test  in  favor  of  Professor  Ram- 
say's baryta  water  one,  for  the  first  indications  of  decomposition  in 
chloroform.  The  state  of  decomposition  which  the  chloroform  was 
in  at  the  time  the  experiments  were  made  justified  me  in  doing  so. 
I  now  find,  however,  after  carefully  watching  the  decomposition  in 
sunlight  from  the  first  indications  of  it  until  it  has  reached  a  point 
where  no  reaction  is  obtained  with  zinc  iodide  and  starch,  that  this 
reagent  deserves  the  first  place  as  an  indicator,  the  nose  the  second, 
and  that  baryta  water  may  be  dispensed  with  altogether.  The 
chlorine  reaction  had  almost  disappeared  from  the  chloroform 
employed  in  my  previous  experiments,  which  explains  how  I  was 
led  to  place  baryta  water  as  a  test  for  decomposition  in  such  a  fialse 
position.  It  was  invariably  observed  that  no  reliable  reaction  with 
baryta  water  was  obtained  until  decomposition  was  unmistakably 
recognized,  both  by  zinc  iodide  and  starch  and  by  the  sense  of 
smell,  and,  further,  that  the  carbonyl  chloride  reaction  was  obtained 
from  samples  in  the  most  advanced  stages  of  decomposition. 
Soon  after  zinc  iodide  and  starch  begins  to  indicate,  decomposi- 
tion may  easily  be  recognized  by  the  peculiar  odor  of  carbonyl 
chloride,  which  indication  renders  the  application  of  baryta  water, 
or  any  other  reagent,  quite  unnecessary  for  the  purpose  of  estab- 
lishing the  presence  of  decomposition. 
During  its  first  stages  a  distinct  reaction  is  obtained  with  zinc 
iodide  and  starch,  but  none  with  baryta  water,  a  separation  of  water 
being  also  observed.  After  further  decomposition  zinc  iodide  and 
starch  gives  a  more  marked  reaction  than  at  firsthand  baryta  water 
1  Read  before  the  Pharmaceutical  Society  of  Great  Britain  at  an  evening 
meeting  in  Edinburgh,  March  15  ;  Phar.  Jour,  and  Trans.,  March  25,  1893, 
p.  792. 
