544  New  Test  for  Morphia.  {^beTi,  w7t"* 
The  whole  of  the  resin  however  could  not  be  removed  by  water 
from  solutions  of  opium.  Thirty  grams  of  extract  which  no  longer 
gave  a  precipitate  upon  the  addition  of  water,  yielded  2*5  grams  of 
black  resin  when  treated  with  ammonia*  Although  in  this  case  the 
extract  was  the  product  of  a  fourth  maceration,  the  phenomenon 
occurred,  but  in  a  less  degree,  under  ordinary  conditions. 
It  thus  appears  that  the  same  matter  will  alternately  pass  through 
a  filter  without  residue  or  leave  an  enormous  residue,  according  as 
the  quantity  of  water  employed  is  small  or  large  ;  also  that  the  precipi- 
tation ceases  when  the  weight  of  the  menstruum  is  about  ten  times 
greater  than  that  of  the  substance.  It  is  even  possible  to  dissolve  in 
a  very  concentrated  cold  solution  a  deposit  that  has  not  been  obtained 
from  it.  Finally,  that  the  heat  of  a  water-bath  will  restore  the 
homogeneity  destroyed  by  an  excess  of  water,  an  observation  that  is 
not  in  accord  with  what  has  been  written  by  other  authors.  The 
constant  results  obtained  during  his  experiments  have  induced  M. 
Perier  to  formulate  his  conclusions  as  follows  : — 
(1)  The  quantity  of  distilled  water  at  15°  C.  in  which  extract  of 
opium  is  dissolved  has  a  direct  and  certain  influence  upon  the  partial 
elimination  of  the  resinoid  matter. 
(2)  Concentrated  aqueous  infusions  of  extract  of  opium  do  not 
give  any  notable  precipitate,  except  with  the  lapse  of  time  ;  dilute 
solutions,  where  the  weight  of  the  menstruum  exceeds  twice  that  of  the 
matter  dissolved,  give  as  much  more  residue  as  the  proportion  of 
water  is  increased  from  two  to  ten. 
(3)  Water,  in  whatever  quantity  does  not  precipitate  the  whole  of 
the  resinoid  matter ;  a  certain  portion  yields  only  to  ammonia. 
(4)  The  residue  of  extract  of  opium  treated  with  cold  water  re- 
dissolves  in  the  concentrated  mother  solution,  and  heat,  instead  of 
aiding  in  the  separation  of  the  resin,  oil  and  narcotina,  reconstitutes 
the  homogeneity  of  the  extract. — Phar.  Jour.  (Lond.)  Oct.  11,  1873, 
A  NEW  TEST  FOR  MORPHIA  * 
By  Louis  Siebold. 
In  conducting  a  series  of  experiments  on  organic  alkaloids,  I  dis- 
covered a  new  test  for  morphia,  which  greatly  exceeds  in  delicacy 
the  tests  hitherto  known  for  that  substance.    If  it  is  to  be  applied 
*  Read  be-fore  the  British  Pharmaceutical  Conference.. 
