ON  FERRATED  TINCTURE  OF  CINCHONA. 
305 
gradually  a  precipitate  in  which  the  presence  of  kinic  acid  can 
be  readily  proved,  but  which  is  free  from  alkaloids. 
Which  medicinally  important  organic  constituents  remain  now 
in  the  tincture?  Besides  a  minute  proportion  of  kinic  acid,  if 
that  be  important  at  all — only  the  alkaloids,  and  these  not  in  the 
same  combination  in  which  the  bark  originally  contained  them. 
Such  a  ferrated  tincture  of  bark  is  therefore  essentially  nothing 
but  an  alcoholic  solution  of  the  citrates  of  the  alkaloids  and 
iron,  together  with  minute  quantities  of  sugar  and  probably  of 
a  compound  of  iron  with  some  product  of  decomposition  of 
cinchotannic  acid,  to  which  it  owes  the  darker  color,  unless  that 
be  due  to  altered  alkaloids,  (chinoidine.) 
I  contemplated  at  one  time  to  use  a  lead  salt,  acetate  of  lead, 
for  precipitating  tannin;  but  all  the  other  soluble  acids  are 
likewise  precipitated  by  this  reagent,  and  more  completely  so, 
than  by  iron.    Such  a  process  is  therefore  likewise  unfeasible. 
Upon  the  whole,  I  have  come  to  the  conclusion  that  a  ferrated 
tincture  of  bark  is  a  preparation  deserving  neither  to  be  coun- 
tenanced by  pharmaceutists,  nor  the  confidence  of  the  physician. 
All  that  is  really  valuable  in  it  we  can  have,  in  more  definite  and 
consequently  more  reliable  form,  by  making  a  solution  of  citrate 
of  quinia  or  cinchonia  and  citrate  of  iron,  either  in  water,  in  wine 
or  some  other  alcoholic  liquid.  If  a  citrate  of  quinia,  and  per- 
haps also  a  citrate  of  cinchonia  was  officinal,  these  preparations 
might  be  employed  by  themselves,  and  if  the  physician  wished 
to  give  at  the  same  time  a  preparation  of  iron,  he  might  pre. 
scribe  with  one  of  the  former  salts,  either  citrate  or  ammonio- 
citrate  of  iron  in  any  proportion  to  suit  a  particular  case. 
It  must  be  remarked  yet,  that  16  grains  of  citrate  of  iron 
are  not  wholly  soluble  in  one  fluid  ounce  of  alcohol  of  '877, 
not  even  with  the  addition  of  some  free  citric  acid ;  and  when 
a  concentrated  aqueous  solution  of  this  salt  containing  the 
amount  stated  is  added  to  a  fluid  ounce  of  such  alcohol,  a  pre- 
cipitate is  gradually  deposited. 
Philadelphia,  May,  1861. 
20 
