*MMJayUi,'iwa*M'}  Formulas  from  Pharmacopcea  Germanica.  219 
Neither  iodine  or  mercury  is  set  free  during  any  stage  of  the  pre- 
cipitation, as  in  the  case  of  mercurous  nitrate  and  iodide  of  potassium. 
If  the  solution  of  pyrophosphate  of  sodium  and  mercurous  acetate 
contains  some  mercuric  acetate,  a  pale  red  coloration  of  the  liquid 
will  be  produced  towards  the  close  of  the  reaction  by  the  separation  of 
biniodide  of  mercury,  which  is  easily  removed  by  a  slight  excess  of 
potassium  iodide,  the  dilute  solution  of  this  salt  not  decomposing  the 
protiodide  of  mercury  while  it  readily  dissolves  the  biniodide.  It  is 
well  not  to  omit  the  precaution  of  testing  the  precipitate  for  this  con- 
tamination, by  washing  a  portion  with  hot  alcohol.  The  precipitate 
Is  washed  with  cold  water  by  decantation,  collected  upon  a  filter  and 
dried  at  a  moderate  temperature,  protected  from  the  light. 
It  is  true  that  this  process  is  more  costly  than  those  described  in 
standard  works,  but  the  quality  of  the  product  is  such  that  these  ob- 
jections amount  to  nothing. 
SELECTED  FORMULAS  FROM  PHARMACOPCEA  GERMANICA. 
By  the  Editor. 
(Continued  from  page  163  of  last  number.) 
Mixtura  gummosa.  Finely  powdered  gum  arabic  and  sugar,  each 
15  p.;  distilled  water  170  parts. 
Mixtura  oleoso-balsarnica,  s.  Balsamum  vitce  Hoffmanni.  3  parts 
of  balsam  of  Peru,  1  part  of  each  of  the  volatile  oils  of  lavender, 
cloves,  Chinese  cinnamon,  thyme,  lemon,  mace  and  orange-flowers, 
240  parts  of  90  per  cent,  alcohol. 
Mixtura  sulfurica  acida,  s.  Elixir  acidum  Halleri.  Add  gradually 
sulphuric  acid,  1  part,  to  90  per  cent,  alcohol,  3  parts. 
Mixtura  (Aqua)  vuhieraria  acida  s.  Thedenii.  Vinegar.  6  p.;  68 
per  cent,  alcohol,  3  p.;  dilute  sulphuric  acid  (sp.  gr.  1*113 — 1-117), 
1  p.;  purified  honey,  2  parts.    Mix  and  filter. 
Mucilago  Cydonice.  Quince  seed,  1  p.;  rose  water,  50  p.  Mace- 
rate for  half  an  hour,  with  frequent  agitation,  and  strain. 
Mucilago  (Decoctum)  Salep.  Put  1  part  of  powdered  salep  into  a 
flask  containing  10  parts  of  cold  water,  and  mix  well  by  agitation  ; 
then  add  90  parts  of  boiling  water,  and  shake  the  mixture  continu- 
ously until  cool. 
Oxymel  Colchici.  Mix  vinegar  of  colchicum,  1  part,  with  clarified 
honey,  2  parts.   Evaporate  to  2  parts,  and  strain. 
