4 
Incompatibility  in  Prescriptions. 
Aru.  Jour.  Pharm. 
Jan.,  1890. 
Phosphates  (ortho)  are  insoluble,  except  those  of  the  alkali  metals. 
Sulphates  are  soluble,  except  those  of  barium^  strontium,  calcium  (s), 
antimony,  lead,  mercurous  (s)  and  silver  (s). 
Sulphides  are  insoluble,  except  those  of  barium,  calcium  («),  stron- 
tium, and  the  alkali  metals. 
Sulphites  are  soluble,  except  those  of  aluminium,  antimony,  barium, 
bismuth,  calcium  (s),  cobalt  (s),  copper,  ferrous  (s),  lead,  manganese  (s), 
nickel  (s),  silver,  stannous,  strontium  and  zinc  (s). 
Tartrates  are  soluble,  except  those  of  antimony,  barium,  bismuth, 
cadmium  (s),  calcium  (s),  copper  (s),  ferrous  (s),  lead,  manganese  (s), 
mercuric,  mercurous,  nickel  (s),  silver,  strontium  (s)  and  zinc  (s). 
Acids  decompose  hydrates,  carbonates  and  acid  carbonates  to  form 
salts ;  the  stronger  acids,  which  are  largely  inorganic,  set  free  the 
weaker  acids,  which  are  largely  organic,  or,  brought  in  contact  with 
alcohol  or  alcoholic  solutions,  form  ethers ;  alkaline  hydrates,  car- 
bonates and  acid  carbonates  neutralize  free  acids,  decompose  some 
glucosides  and  precipitate  all  alkaloids,  some  of  which  precipitates  are 
soluble  in  excess  of  the  precipitant,  or  in  alcohol,  if  that  liquid  be 
present  in  sufficient  amount  to  dissolve  them. 
Oxidizing  agents  such  as  nitric,  hydrochloric,  nitro-hydrochloric, 
picric  and  chromic  acids,  and  potassium  bichromate  and  permanga- 
nate, with  readily  oxidizable  substances,  such  as  carbohydrates,  alco- 
hols, ethers,  sulphur,  phosphorus,  sulphides,  and  organic  matter  in 
general,  form  explosive  compounds.  Potassium  permanganate,  if 
ordered  in  pill  form,  can  best  be  made  with  cacao  butter,  and  cosmo- 
line  in  very  small  quantity,  and  enclosed  in  gelatin  capsules.  Silver 
nitrate  is  reduced  by  organic  matter  to  oxide,  with  the  exception,  it  is 
said,  of  opium  and  extract  of  hyoscyamus.  A  very  good  way  of 
making  pills  of  it  is  with  cacao  butter  and  cosmoline,  etc.,  as  men- 
tioned above,  under  potassium  permanganate;  syrup  of  ferrous  iodide 
and  potassium  chlorate  form  a  poisonous  compound,  and  potassium 
iodide  and  potassium  chlorate  form  a  mixture  which  yields  the  poison 
ous  iodate  on  being  taken  internally.1 
Iodine  and  the  iodides  yield  precipitates  with  the  alkaloids ;  bro- 
mides precipitate  morphine  and  strychnine  salts  on  standing,  but  a 
few  drops  of  dilute  hydrochloric  acid  added,  after  the  addition  of  the 
alkaloid,  prevents  the  change.    Sodium  biborate  precipitates  mor- 
(s)  means  sparingly  soluble. 
1  Am.  Jour.  Phar.,  1876,  p.  277. 
