496  Compai'ison  of  Galenical  Preparations.  {'^^'oct^'^ss^^' 
50  parts  U.  S.  Senna  18,  glycyrrhiza  18,  fennel  9,  washed  sulphur  9, 
sugar  54  parts  P.  G. 
Fulvis  Ipecacuanhce  et  Opii,  U.  S.  Pulvis  Ipecacuanhse  opiatus, 
P.  G. — Identical,  except  that  the  opium  used  must  contain  between  12 
and  16  per  cent.  U.  S.,  not  less  than  10  per  cent.  P.  6r.,  of  morphine. 
Pulvis  Rhei  compositus,  U.  S.  Pulvis  Magnesise  cum  Rheo  P.  G. — 
Rhubarb  25,  magnesia  65  and  ginger  10  parts.  U.  S. — Rhubarb  15, 
magnesium  carbonate  60,  and  oil  sugar  of  fennel  40  parts.  P.  G, 
Resina  JalapcE,  U.  8.,  P.  G, — The  processes  are  identical,  except 
that  jalap  root  is  exhausted  by  percolation  U.  S.,  or  by  maceration  P. 
G. — The  test  of  the  U.  S.  Pharmacopoeia,  that  the  portion  of  the  resin 
insoluble  in  ether,  should  be  dissolved  by  potassa  solution  and  not  pre- 
cipitated by  an  acid,  is  correct.  But  the  next  test  which  is  also  that  of 
the  German  Pharmacopoeia  is  incorrect;  it  requires  that  1  part  of  the 
resin  be  soluble  in  50  parts  (5  parts,  P.  G.,  Avhich  is  not  quite  suffi- 
cient) of  warm  ammonia  water,  that  this  solution  on  cooling  do  not 
gelatinize  (absence  of  colophony)  and  on  being  supersaturated  with  an 
acid,  remain  clear.  This  last  requirement  is  correct  only  for  that  por- 
tion which  is  insoluble  in  ether,  but  not  for  the  small  portion  soluble 
in  ether. 
Resina  Podophylli^  U.  8,  Podophyllinum,  P.  G. — The  German 
Pharmacopoeia  gives  no  process,  but  merely  a  description  and  tests. 
Among  the  latter  may  be  mentioned,  that  the  preparation  on  being 
agitated  with  cold  water  and  filtered,  yields  a  colorless  bitter  liquid, 
which  is  without  action  on  litmus  paper,  is  colored  brown  by  ferric 
chloride  and  becomes  opalescent  with  subacetate  of  lead,  depositing 
after  some  hours,  reddish-yellow  floccules. 
Sodii  carbonas  exsiccatus,  U.  S.  Natrium  carbonicum  siccum,  P.  G. 
— The  processes  are  identical,  except  that  the  crystallized  sodium  car- 
bonate is  allowed  to  effloresce  by  exposure  to  warm  air,  U.  S.,  or  at  a 
temperature  not  exceeding  25°C.  (77°F.),  P.  (r.,  and  afterwards  dried 
to  one-half  its  original  at  a  temperature  of  about  45°C.  (113°F.),  U.  S.y 
or  between  40°  and  50°C.  (104°  and  122°F.),  P.  G. 
Spiritus  ^theris,  U.  S.  Spiritus  sethereus,  P.  G. — ^ther  spec.  grav. 
•750,  30  parts,  alcohol  70  parts,  U.  S. — ^ther  spec.  grav.  '726, 1  part, 
alcohol  3  parts,  P.  G. — The  percentage  of  absolute  ether  in  both  pre- 
parations is  very  nearly  alike. 
Spiritus  JEtheris  nitrosi,  U.  S.,  P.  G. — Mix  sulphuric  acid  7  parts 
with  alcohol  31  parts,  add  nitric  acid  9  parts,  and  distil  at  or  b^ow 
