Am.  Jour.  Pharm. 
June,  1895. 
The  Tannin  of  Cloves. 
301 
After  allowing  sufficient  time  for  the  liquid  to  thoroughly  pene- 
trate the  hide,  the  flow  of  the  siphon  was  started  by  gentle  suction 
applied  to  the  long  arm.  The  hide  retained  the  tannin  and  coloring 
matter,  but  allowed  the  other  constituents  of  the  decoction  to  pass 
through  in  solution. 
The  first  30  c.c.  of  the  liquid  obtained  in  this  manner  were  con- 
sidered as  containing  the  soluble  matter  of  the  hide,  and  were  there- 
fore rejected.  The  succeeding  50  c.c.  that  were  received  from  the 
siphon  were  evaporated  to  a  constant  weight  on  a  water- bath  to 
ascertain  the  amount  of  solids  unabsorbed  by  the  hide.  50  c.c.  of 
the  original  decoction  were  likewise  evaporated  to  a  constant  weight 
to  determine  the  total  solids  present.  The  difference  between  the 
weights  of  the  solids  in  these  equal  volumes  was  taken  as  the 
amount  of  tannin  absorbed  by  the  hide,  and  from  this  quantity  the 
percentage  was  calculated  by  simple  proportion  to  the  weight  of 
air-dry  cloves  represented  by  this  volume  of  decoction. 
The  following  results  were  obtained  : 
Sample  Where  Percentage 
No.  Obtained.  of  Tannin. 
i   .  .  St.  Louis  10*50 
2   Philadelphia  11  '60 
3  *  Philadelphia  12*65 
4  New  York  10*03 
5  =  Philadelphia  ■  12*00 
6  St.  Louis  13-35 
7  •  •  •  •  St.  Louis  .  5-50 
The  samples,  with  the  exception  of  No.  7,  were  obtained  from 
the  better  wholesale  and  retail  stores.  No.  7  was  purposely  bought 
from  the  very  cheapest  trade  in  order  to  estimate  the  tannin  in  an 
adulterated  article, 
Based  upon  the  difference  in  percentage  of  tannin  found,  an  esti- 
mation of  that  principle  might  be  of  some  service  in  deciding 
whether  a  sample  of  cloves  was  of  good  quality. 
ISOLATION  AND  PURIFICATION. 
To  extract  the  tannin  in  order  that  an  investigation  of  its  chemi- 
cal characters  might  be  made,  a  quantity  of  powdered  cloves  of  good 
quality  was  exhausted  by  percolation  with  acetone.  The  solvent 
was  recovered  from  the  percolate  by  distillation,  the  residual  extract 
thoroughly  agitated  with  water,  and  the  resulting  mixture  filtered. 
The  filtrate  was  agitated  with  acetic  ether,  which  removed  some 
