282 
Economic  Botany. 
Am.  Jour.  Pharm. 
June,  1894. 
Reagent.  Tannin  of  P.  Granatum.  Gallotanmc  Acid. 
Ferric  chloride,  .  .  .  .  ^  Blue-black  ppt.  Blue-black  ppt. 
and  l 
Ammon.  carbonate,  .  .  J  Purple  ppt.  Purple  ppt. 
Tartar  emetic,    .  .  .  .  \  Faint  cloudiness.  Faint  cloudiness, 
and  [■ 
Amnion,  chloride,    .  .  J  Pale  ppt.  Pale  ppt. 
Potassium  bichromate,  Brown  ppt.  Brown  ppt. 
Calcium  hydrate,      .  .'  \  Ivight-colored  ppt,  turn-  Light-colored  ppt.,  turn- 
J        ing  blue.  ing  blue. 
Bromine  water,  ....  No  ppt.  No  ppt. 
Ferric  acetate,    ....  Blue-black  ppt.  Blue-black  ppt. 
The  tannins  were  submitted  to  ultimate  analysis  with  the  following 
results : 
i.  ii.  in. 
Carbon,   50*60  50*52  50*34 
Hydrogen,   3*88  4-13  3*98 
Oxygen,    45-52  45*35  45*68 
100*00  IOO'OO  IOO'OO 
Average  of  Gallotannic  acid 
three  combustions.  C14H10O9. 
Carbon,   50*48  52*10 
Hydrogen,   3*99  3*52 
Oxygen,   45*53  44*38 
IOO'OO 
In  view  of  the  fact  that  the  qualitative  reactions  of  this  tannin 
agree  with  those  of  gallotannic  acid,  and  that  the  ultimate  composi- 
tion compares  quite  closely  for  a  substance  so  difficult  to  purify,  on 
account  of  its  amorphous  condition,  we  are  forced  to  conclude  that 
the  tannin  of  Punica  Granatum,  is  identical  with  that  of  galls. 
ECONOMIC  BOTANY. 
By  Edson  S.  Bastin,  A.M. 
Economic  Botany  may  be  briefly  defined  as  botany  applied  to 
useful  ends,  or  as  the  study  of  plants  in  relation  to  the  wants  of 
mankind.  That  plants  do  stand  in  very  close  relation  to  human 
happiness  and  welfare,  and  even  to  the  necessities  of  man's  exist- 
ence, is  a  fact  so  obvious  that  it  scarcely  needs  to  be  dwelt  upon. 
We  depend  upon  the  vegetable  world  for  the  greater  share  of  our 
food,  and,  if  we  take  into  account  the  fact  that  the  animals  we 
employ  for  food,  all  either  directly  or  indirectly  obtain  sustenance 
