504  PHARMACEUTICAL  NOTES  AND  GLEANINGS. 
PHARMACEUTICAL  NOTES  AND  GLEANINGS. 
Hydrocyanate  of  Iron. — It  has  been  stated  in  the  medical 
journals,  that  "  hydrocyanate  of  iron"  had  been  used  advantage- 
ously in  epilepsy.  Having  been  applied  to  for  the  salt,  and  be- 
ing at  a  loss  to  determine  what  compound  was  intended,  we 
consulted  several  athorities  without  satisfaction. 
The  dose,  one  or  two  grains,  would  indicate  a  more  active 
substance  than  prussian  blue.  Hydrocyanate  of  potassa  is 
synonymous  with  cyanide  of  potassium.  Why  not  hydrocyan- 
ate of  iron  then  be  cyanide  of  iron?  Gmelin  says,  (Handbook, 
vol  vii.,  p.  432,)  that  "  When  aqueous  cyanide  of  potassium  is 
mixed  with  a  ferrous  salt  free  from  ferric  oxide,  a  light  red  brown 
precipitate  is  obtained,  which  dissolves  in  acids.  The  composi- 
tion of  this  precipitate  requires  further  investigation,  but  it  is, 
perhaps,  the  true  protocyanide  of  iron  C2  N  Fe."  In  attempting 
to  dry  this  precipitate  it  assumes  the  color  of  prussian  blue,  by 
contact  with  the  air  during  this  process.  By  washing  this  pre- 
cipitate with  boiled  water,  and  afterwards  displacing  most  of  the 
water  from  the  particles  by  alcohol,  and  then  drying,  the  same  result 
occurred,  viz.,  the  whole  mass  gradually  assumed  a  blue  color,  but 
not  so  deep  as  prussian  blue.  Hydrocyanic  acid  shaken  with  solu- 
tion of  carbonate  of  iron  in  carbonic  acid  water,  forms  a  greenish 
oxide  of  iron,  which  turns  blue  by  exposure  to  the  air.  There 
is  a  white  cyanide  of  iron  formed  when  aqueous  sulphuretted 
hydrogen  is  agitated  with  finely-powdered  prussian  blue  which 
converts  it  into  protocyanide  of  iron  ;  it,  however,  becomes  blue 
by  exposure.  There  is  also  a  permanent  cyanide  of  iron  obtained 
when  the  ferrocyanide  of  ammonia  is  boiled  in  close  vessels  till 
the  hydrocyanate  of  ammonia  all  sublimes,  but  it  is  insoluble  in 
acids.  It  is  to  be  regretted  that  medical  writers,  in  referring  to 
the  therapeutic  powers  of  new  remedies,  do  not  take  more  pains 
to  identify  the  substances  they  have  employed  where  any  doubt 
may  arise.  We  supplied  the  compound  obtained  by  double  de- 
composition between  cyanide  of  potassium  and  protosulphate  of 
of  iron,  partially  washed  with  alcohol,  and  dried  in  a  jar  over 
sulphuric  acid,  but  have  not  yet  learned  whether  it  had  the  de- 
sired effect. — Ed. 
Sulphate  of  Quinldinia. — Last  year,  Dr.  William  Pepper, 
Physician  to  the  Pennsylvania  Hospital,  published  an  account  of 
