260  Madura  Aurantiaca,  Nuttall.  {kVTi\mT' 
concentrated  and  again  set  aside.  A  second  deposit  was  thus  obtained, 
which  was  separated  and  mixed  with  the  first.  Upon  applying  some 
of  the  tests  as  laid  down  by  Wagner  for  moric  acid,  this  product  was 
found  to  agree  with  them.  The  mother  water  gave  strong  evidence 
of  containing  morintannic  acid.  The  substance  supposed  to  be  moric 
acid  was  then  purified  by  repeated  solution  in  alcohol  and  precipita- 
tion by  water.  After  this  treatment  the  product  was  quite  small,, 
being  less  than  one  gram.  It  was  of  a  dark-greenish  color,  readily 
soluble  in  alcohol,  giving  a  brown  red  solution,  sparingly  soluble  in 
cold  water,  more  so  in  hot.  To  litmus  it  gave  a  strong  acid  reaction* 
Upon  applying  the  tests  for  moric  acid,  it  was  found  to  agree  with 
them,  except  in  that  with  ferric  chloride.  This  test  should  give  a 
garnet-red  coloration,  but  the  color  produced  was  a  greenish-black. 
This  was  ascribed  to  the  presence  of  a  small  quantity  of  morin- 
tannic acid,  as,  according  to  Wagner,  ferric  chloride  produces  this 
coloration  with  moric  acid,  if  the  latter  is  contaminated  with  any 
morintannic  acid.  The  following  tests  for  moric  acid  proved  its  pres- 
ence in  the  substance  extracted : 
1st.  Sparing  solubility  in  cold  water. 
2d.  Free  solubility  in  alcohol  and  ether. 
3d.  Precipitation  from  its  alcoholic  solution  on  the  addition  of  water. 
4th.  Solubility  in  H2S04,  and  precipitation  on  the  addition  of 
water. 
5th.  Lemon  colored  precipitate  in  aqueous  solution  by  SnCl2. 
6th.  Non-precipitation  in  aqueous  solution  by  gelatin. 
7th.  Olive-green  color  of  aqueous  solution  by  FeS04. 
8th.  Yellow  color  by  alkalies  and  alkaline  carbonates. 
Upon  examination  of  the  substance  for  bases,  calcium  and  iron  in 
the  ferric  state  were  clearly  proven,  thus  showing  it  to  consist  of  these 
metals  with  excess  of  moric  acid.  The  presence  of  morintannic  acid 
in  combination  with  iron  would  explain  the  dark-green  color  of  the 
moric  acid. 
The  coloring  power  of  the  acid  was  tested  by  making  an  aqueous 
solution,  and  immersing  in  it  a  piece  of  mordanted  cotton  cloth.  A 
fine  yellow  color  was  acquired,  which,  however,  was  not  entirely  per- 
manent. * 
The  mother  liquor  from  which  the  moric  acid  was  obtained  showed, 
by  the  following  tests,  the  presence  of  morintannic  acid : 
1st.  Astringent  taste. 
