Am'/a0a.ri£o.arm'}       Incompatibility  in  Prescriptions.  5 
phine  and  cocaine  salts,  but  on  the  addition  of  a  small  quantity  of  boric 
acid,  or  with  boric  acid  alone,  precipitation  does  not  take  place. 
Mercuric  chloride  with  acidulated  solutions  of  the  alkaloids  forms 
crystalline  double  salts  ;  potassium-mercuric  iodide  precipitates  alka- 
loidal  solutions.  Solutions  of  quinine  salts  with  those  of  the  alkaline 
acetates,  or  with  Basham's  mixture,  precipitate  the  sparingly  soluble 
quinine  acetate.  Morphine  solutions  give  the  phenol  reaction,  if  mixed 
with  tincture  of  ferric  chloride. 
Glucosides  are  decomposed  by  free  acids  and  precipitated  by  tannin ; 
tannic  and  gallic  acids  precipitate  alkaloids,  albumen,  gelatin  and  the 
majority  of  metallic  salts,  and  yield  inks  with  iron  solutions. 
Resinous  tinctures  and  fluid  extracts,  prescribed  with  aqueous  solu- 
tions, should  always  be  emulsified  with  acacia;  tinctures  and  fluid 
extracts  made  of  stronger  alcohol,  mixed  with  those  made  of  diluted 
alcohol,  become  turbid  and  precipitate,  since  the  special  solvent  power 
of  alcohol,  or  of  water,  for  a  substance  diminishes  in  proportion  to 
the  quantity  of  the  other  liquid  present.  A  "  shake "  label  should 
always  be  used. 
When  for  internal  use,  fixed  and  volatile  oils  and  oleo-resins,  and 
aqueous  solutions,  should  always  be  emulsified,  whether  ordered  or 
not,  and,  to  better  emulsify  the  volatile  oils,  they  should  have  mixed 
with  them,  prior  to  emulsification,  an  equal  volume  of  olive,  almond 
or  cottonseed  oil. 
Tincture  of  ferric  chloride  gelatinizes  mucilage  of  acacia;  free  acids 
separate  insoluble  carminic  acids  from  compound  tincture  of  carda- 
mom ;  free  acids  precipitate  glycyrrhizin  from  fluid  extract  of  licorice. 
Commercial  spirits  of  nitrous  ether  liberates  iodine  from  solutions 
of  iodides,  decomposes  antipyrine  solutions  to  form  a  green  nitro- 
derivative,  and  precipitates  mucilage  of  acacia,  but  if  it  be  well  diluted 
with  water  it  can  usually  be  added  last  without  precipitating.  Tinc- 
ture of  guaiac  and  spirits  of  nitrous  ether  are  stated  to.be  pharma- 
eeutically  incompatible  by  Potter  (although  they  are  often  prescribed 
together),  likewise  infusion  of  wild  cherry  with  compound  infusion  of 
gentian,  infusion  of  cinchona  with  compound  infusion  of  gentian,  and 
infusions  with  metallic  salts  generally. 
Sodium  salicylate  in  solution  precipitates  the  sparingly  soluble  sali- 
cylic acid  if  mixed  with  acids,  and  yields,  if  dispensed  in  powders 
with  potassium  acetate,  the  very  deliquescent  potassium  salicylate. 
Sodium  salicylate  in  strong  solution  is  decomposed  by  tincture  of  ferric 
