^™junT"iS™"}     Ohatti,  and  other  Substances  for  Gim  Arabic.  303 
The  behavior  with  chemical  reagents  is  summarized  in  the  follow- 
ing table : 
Basic  lead  acetate  .  .  . 
Ammonium  oxalate  .  . 
Glassy  Am- 
rad. 
East  India 
Amrad. 
Pale  Am- 
rad. 
Oomra 
Whatti. 
Ghatti. 
Slight  ppt., 
not  gelatin- 
ous. 
White  ppt. 
Gelatinized 
Brownish 
color. 
Ppt. 
Brownish 
opaque 
thick  jelly. 
Slightly  col- 
ored ppt. 
Slight  dark- 
ening. 
Ppt. 
Curdy 
opaque  ppt. 
Slight  ppt. 
White  ppt. 
Curdy  white 
ppt. 
Slight  ppt. 
Ppt. 
No  ppt. 
White  ppt. 
Gelatinized. 
Slight  dark- 
ening. 
Slight  ppt. 
Ppt. 
Translucent 
gelatinous 
ppt. 
Slight  ppt. 
Gelatinized. 
Ppt. 
Mercuric  chloride  .  .  . 
The  oomra  whatti  and  amrad  gums  cannot  be  said  to  have  much 
value  in  practical  pharmacy,  though  they  may  be  well  adapted  for  the 
chief  uses  to  which  the  inferior  qualities  of  gum  arable  were  formerly 
exclusively  put.  They  contain  little  or  no  astringent  principles  to  af- 
fect the  mordants  in  calico  printing,  and  for  strong  adhesive  mucilages 
where  color  is  immaterial  glassy  amrad  and  "  oomra  seem  to  be 
very  suitable.    Concerning    ghatti^'  a  little  more  must  be  said. 
Another  supply  of  mucilage  was  made  according  to  the  formula  : 
Gum  ghatti  ..1  ounce. 
Distilled  water  '  3  fluid  ounces. 
On  straining,  a  few  grains  were  separated  which  had  swollen  to  a 
translucent  jelly,  and  these  remained  undissolved  when  treated  with 
more  water.  The  mucilage  thus  obtained  is  scarcely  as  bright  as  that 
from  picked  gum  arable,  but  quite  equal  to  that  given  by  ordinary 
good  samples  as  to  color,  and  at  the  same  time  more  viscid.  It  is  taste- 
less, inodorous,  and  of  superior  adhesive  properties  to  mucil.  acacise. 
The  emulsifying  power  was  tried  with  olive  oil,  this  being  selected 
in  preference  to  almond  or  castor  oils  as  a  more  crucial  test.  (Several 
emulsions  were  made  with  varying  proportions  of  oil  and  ghatti  mu- 
cilage as  above,  and  some  of  these  are  open  to  comparison  this  evening 
with  others  made  with  the  same  amounts  of  oil  and  acacia  mucilage 
prepared  from  selected  gum. 
No.  1. — Ghatti  mucilage  1,  olive  oil  1,  distilled  water  62. 
No.  2.— Acacia      "        1,      "        1,                "  62. 
No.  3.— Ghatti      "        1,      "        2,      "         "  61. 
No.  4— Acacia      "        1,      "        2,      "         "  61. 
It  will  be  noted  that  the  emulsions  afforded  by  ghatti  mucilage  are, 
