i  w.  Jour.  Phariu. 
June,  1896. 
Tannins  of  Some  Ericaccce. 
319 
liquids,  which  were  filtered  from  the  insoluble  substances  deposited 
during  the  treatment  with  hot  hydrochloric  acid,  were  shaken  with 
ether  in  order  to  remove  any  decomposition  products  which  might 
be  present.  The  several  portions  of  ether,  which  were  employed 
for  this  purpose,  were  mixed,  the  excess  recovered  by  distillation, 
and  the  remainder  allowed  to  evaporate  spontaneously.  Upon  the 
evaporation  of  the  ether,  there  was  left,  from  each  of  the  tannins,  a 
residue  which  was  soluble  in  water.  The  following  table  shows  the 
reactions  given  by  the  water  solutions  of  these  residues : 
Product  from 
Tannin  of 
Potassium 
Cyanide. 
Ferric  Chloride  and 
Sodium  Carbonate. 
Ferrous 
Sulphate. 
Iyead  Acetate. 
Chimaphila  .... 
J  Red   color,  \ 
\    fading.  j 
Green  ppt. ,  red  color. 
• 
rch  ocolate] 
<    brown  > 
I         ppt-  ) 
Yellowish  ppt. 
Trailing  arbutus  .  . 
Red  color. 
f  Dark  green  ppt. .  red 
\  color. 
C  Green  i  sh-] 
<      brown  > 
I         ppt.  j 
Yellowish  ppt. 
Red  color. 
flight  green  ppt.,) 
]    red  color.  j 
Blue  ppt. 
Yellowish  ppt. 
Mountain  laurel  .  . 
Red  color. 
Green  ppt.,  red  color. 
Green. color. 
Yellowish  ppt. 
Red  color. 
(Brown   ppt.,  red-] 
I    brown  ppt.  / 
Brown  ppt. 
Yellowish  ppt. 
(  Red  color, 
\  fading. 
f  Green  color  and  ppt., 
(    deep  claret  color. 
J  Gre enishl 
1      color.  j 
Yellowish  ppt. 
Protocatechuic  acid 
f  Bluish-green  color,  ) 
\    red  color.  ) 
Violet  color. 
White  ppt. 
Gallic  acid  ....  . 
Red  color. 
Deep  blue  ppt. 
No  reaction. 
White  ppt. 
Pine  Wood 
and  Hydro- 
chloric Acid. 
f  Slight  red 
Action  of  Heat. — To  obtain  the  decomposition  products  which 
result  from  the  heating  of  the  tannins  to  such  an  extent  that  their 
chemical  compositions  are  altered,  a  portion  of  the  principle  from 
each  of  the  plants  was  stirred  into  a  few  cubic  centimetres  of 
glycerin  and  the  resulting  mixture  heated  to  1800  C,  for  about  half 
an  hour.  The  temperature  was  then  raised  to  1900  C,  at  which 
point  it  was  maintained  for  ten  minutes.  The  mixtures  were 
allowed  to  become  cold,  and  were  subsequently  dissolved  in  water. 
The  water  solutions  were  shaken  with  successive  portions  of  ether, 
which  were  separated  and  allowed  to  evaporate  spontaneously.  The 
residues  which  were  thus  obtained  were  dissolved  in  water  and 
submitted  to  the  reactions  expressed  in  the  following  chart : 
