60  ON  THE  REVISION  OF  THE  U.  S.  PHARMACOPCEIA. 
years  the  writer  has  examined  some  twelve  samples  of  opium, 
ten  of  which  were  purchased  for  the  army  and  navy,  where  profits 
were  not  at  stake,  and  price  a  secondary  object.  In  four  in- 
stances the  portion  examined  was  from  the  powder  resulting 
from  the  careful  drying  and  powdering  of  half  a  case ;  while  in 
all  the  remainder,  the  samples  were  selected  with  care  from  va- 
rious lumps,  whenever  such  selection  was  possible.  Several  other 
examinations  were  made  where  no  selection  was  possible,  but  the 
results  were  all  below  those  now  to  be  given.  In  no  instance  of 
these  examinations  did  the  yield  of  crude  morphia  exceed  8.1 
per  cent.,  whilst  the  average  of  the  specimens  was  scarcely  above 
7.6  per  cent.  If  this  may  be  taken  as  expressing  the  condi- 
tion of  the  general  market  for  this  drug,  the  common  statement 
of  authoritative  writers,  that  good  opium  contains  from  ten  to 
twelve  per  cent,  of  morphia,  now  needs  re-examination  and  re- 
vision. 
The  relative  expense  of  opium  and  salts  of  morphia  taken  in 
connection  with  the  troublesome  and  expensive  process  of  ex- 
traction and  manufacture  leads  to  the  inference  that  manufac- 
turers, to  be  able  to  sell  the  preparation  at  fair  profits,  must  ob- 
tain much  greater  yields  than  would  be  indicated  by  the  exami- 
nation of  any  opium  the  writer  has  ever  met  with. 
Zinci  Qhloridwm. 
The  writer  agrees  with  Dr.  Bache,  (see  U.  S*  Dispensatory, 
11th  eel.  p.  1351,)  that  the  fused  chloride  is  by  far  the  most 
eligible  preparation,  for  many  reasons.  First,  it  is  a  matter  of 
some  difficulty  to  dry  the  salt  as  directed  in  the  Pharmacopoeia, 
since  a  portion  of  it  is  very  liable  to  fuse  before  other  portions  are 
dry.  Again,  after  fusion  it  is  much  more  easily  managed,  col- 
lected and  preserved  without  material  deliquescence  ;  and  finally, 
it  is  far  more  easily  applied  to  the  ordinary  purposes  for  which 
it  is  used,  and  occupies  much  less  space.  The  fusion  is  easily 
effected  in  the  evaporating  basin  in  which  the  solution  has  been 
concentrated,  and  requires  only  a  gas  or  lamp  flame  to  effect  it. 
With  proper  care,  therefore,  it  becomes  quite  useless  to  transfer 
it  to  a  crucible. 
Should  the  chloride  become  colored  from  the  organic  matter 
of  filters,  from  dust  or  other  like  causes,  as  it  is  very  liable  to  do 
