242  Practical  Notes  from  Foreign  Journals.  {^"^M^^-im^^' 
and  soluble  in  water ;  if  by  washing  with  water  the  amount  of  jS'aO 
has  not  been  decreased  to  less  than  about  1  NaO  for  100  FegOg,  then 
on  the  addition  of  sugar  and  drying,  a  water  soluble  ferric  saccharate 
with  excess  of  sugar  is  obtained. — Archiv  d.  Fhar.,  February  1888,  p. 
137-154. 
Pure  glacial  phosphoric  acid  may  be  obtained  from  sodium  pyro- 
phospate  by  treating  it  with  fuming  hydrochloric  acid,  spec.  grav. 
1.190,  filtering  through  platinum  sponge  from  the  sodium  chloride, 
removing  arsenic  by  means  of  sulphuretted  hydrogen,  and  evaporating 
in  a  platinum  vessel.  Sodium  chloride  is  almost  insoluble  in  hydro- 
chloric acid  of  the  above  strength  ;  a  weaker  acid  will  not  remove  the 
soda. — Zeitsch.  f.  anal.  Chem.,  1888,  p.  24. 
Salicylate  of  mercury  is  said  to  be  prepared  by  precipitating  mer- 
curic nitrate  with  alkali  salicylate,  washing  with  water  and  diluted 
alcohol,  and  drying  in  the  shade.  B.  Fischer  describes  it  (Phar.  Ztg., 
1888,  p.  146),  as  a  white  inodorous  and  tasteless  powder  of  neutral 
reaction,  very  sparingly  soluble  in  water  or  alcohol,  but  soluble  in 
solution  of  table  salt.  It  is  not  decomposed  by  acetic,  tartaric,  lactic 
or  carbonic  acid,  but  mineral  acids  liberate  salicylic  acid.  It  contains 
59  per  cent,  of  hydrogen,  and  its  formula  is  C6H4.C020Hg.  Its  com- 
plete solubility  in  caustic  soda  solution  may  serve  as  a  test  for  its 
purity.  A  solution  for  dispensing  may  be  prepared  by  triturating 
10  gm.  of  the  salt  with  15  or  20  gm.  of  sodium  chloride  dissolved  in 
water,  adding  about  150  gm.  water,  heating  in  a  water  bath  until 
solution  is  effected,  and  diluting  with  2500  cc.  hot  water. 
Magnesium  salicylate  has  been  recommended  by  Huchard  in  abdom- 
inal typhus  as  preferable  to  bismuth  salicylate.  According  to  B. 
Fischer  (Phar.  Ztg.,  1888,  p.  146),  the  salt  is  prepared  by  dissolving 
salicylic  acid  in  boiling  water,  saturating  the  solution  with  magnesium 
carbonate,  filtering  and  crystallizing.  It  forms  long,  colorless  needles, 
is  readily  soluble  in  water  and  alcohol  and  has  a  somewhat  bitter  taste. 
When  given  in  large  doses  of  3  to  6  gm.  daily  it  causes  no  unpleasant 
effects. 
Impure  potassium  iodide,  containing  sulphite,  has  been  met  with 
in  commerce  by  C.  Daudt  [Phar.  Ztg.,  1888,  p.  117).  The  sample 
responded  to  the  pharmacopoeial  tests  for.  iodate,  nitrate,  chloride  and 
thiosulphate ;  but  the  hydrogen  gas  evolved  on  testing  for  nitrate  with 
zinc  and  hydrochloric  acid,  produced  a  black  color  on  lead  paper,  due 
.  to  the  presence  of  sulphite,  soluble  sulphides  being  absent. 
