NOTES  ON  BENZOIC  ACID  AND  SOME  BENZOATES. 
207 
introduced  into  a  sand  bath  of  260°,  and  kept  at  this  tempera- 
ture until  aqueous  vapors  ceased  to  be  condensed  in  the  upper 
part,  it  now  weighed  50.85  grs.;  the  loss  therefore  amounted  to 
51.18— 50.85,  =0.33  grs.  or  10.71  per  cent. 
From  these  data,  the  following  formula  is  calculated  for  this 
ter-benzoate  of  iron. 
Fe203  80        16.91  16.50 
3C14H503  339       71.67       71.44  (see  below.) 
6  HO  54       11.42  10.71 
Fe203,3C14H503-f6HO     473  100.00 
Ter-benzoate  of  iron,  as  thus  obtained,  is  in  a  light  powder, 
of  a  beautiful  orange  color,  permanent  in  the  air,  turning  brown 
between  270  and  280°  ;  it  fuses  and  yields  when  carefully 
heated,  at  first  pure  benzoic  acid,  afterwards  an  empyreumatic 
liquid  of  an  acid  reaction,  which  appears  to  be  principally  the 
same  acid,  and  congeals  in  scales.  Water  and  alcohol  dissolve 
a  portion  of  it,  probably  an  acid  salt,  and  leave  a  basic  salt 
behind. 
Benzoic  acid  is  scarcely  used  in  medicine,  except  in  paregoric 
and  occasionally  in  ointments  ;  when  taken  internally,  it  is  stated 
to  act  as  a  stimulant.  Combined  with  iron  as  in  the  above  salt, 
it  might  perhaps  prove  useful  in  the  hands  of  the  physician.  The 
salt  has  very  little  taste,  not  at  all  ferruginous,  and  would  certain- 
ly be  preferable  to  the  acid,  or  the  alkaline  salts  which  possess 
a  marked  acrimony. 
When  the  above  ter-benzoate  is  desired,  the  directions  above 
given  for  its  preparation  should  be  closely  followed;  the  filtrate 
from  the  precipitate  separates  in  the  course  of  two  days, 
another  precipitate,  which  dries  upon  the  filter  in  a  yellowish 
powder,  and  in  orange  brown  scales,  evidently  a  mixture  of  dif- 
ferent compounds;  and  after  three  weeks,  more  of  the  light  pow- 
der is  deposited.  The  drying  is  to  be  accomplished  in  thin 
layers  upon  a  brick  tile.  .  . 
Bibenzoate  of  Ammonia.— In  order  to  determine  as  near  as  possi- 
ble the  quantity  of  benzoic  acid  in  the  iron  salt,  the  above  filtrate 
from  the  treatment  of  the  ferric  benzoate  with  ammonia  was 
evaporated,  and  kept  at  a  temperature  of  below  190°  F.,  until 
a  dry  mass  remained  behind  and  the  loss  of  weight  ceased.  The 
