Am.  Jour.  Pharm.") 
November,  1896.  / 
The  Tannin  of  Some  Acorns. 
603 
In  order  to  refresh  the  memory  of  the  reader,  a  sectional  illustra- 
tion of  a  chestnut  oak  acorn  is  shown  in  Fig.  2. 
The  several  parts  of  the  chestnut  oak  acorns  were  assayed  for 
tannin,,  commencing  September  first,  when  they  had  reached  their 
full  size,  and  continued  at  intervals  until  the  first  of  October,  when 
they  had  fallen.  The  acorns  of  this  species  were  taken  for  investi- 
gation because  of  their  large  size  and  abundance,  also  because  they 
are  the  fruit  of  the  species  of  oak  whose  bark  is  the  most  highly 
prized  for  its  tanning  value. 
The  estimations  of  tannin  were  made  as  soon  after  the  collection 
of  the  fruit  as  possible.  It  was  necessary,  therefore,  to  determine 
the  moisture,  and  make  a  calculation  of  the  amount  of  tannin  in  the 
Fig.  2. — Section  of  Acorn,  c,  cupule  ;  p>  pericarp  ;  t,  testa  ;  e,  embryo  ; 
cty  cotyledon. 
absolutely  dry  substance,  so  that  in  the  following  results  the  tannin 
and  ash  are  both  based  on  the  absolutely  dry  substance : 
ACORNS  OF  OUERCUS  PRINUS, 
Iv. 
Ash  in 
Tannin  in 
Part 
Date  of 
Dry 
Dry- 
Estimated. 
Collection. 
Moisture. 
Substance. 
Substance. 
•    •  50-56 
1 73 
18-20 
.    .  14-24 
1 '49 
19-00 
1-32 
i3'37 
Pericarp  .  . 
•   •  I3-57 
i-66 
i5'96 
i-94 
42-10 
Testa    .  .  . 
.  .  September  20  .  . 
.  .  iroi 
2'62 
48-09 
Cotyledons  . 
.  .  34-90 
I'07 
8-75 
It  will  be  seen  from  these  figures  that  the  testa  is  exceedingly 
rich  in  tannin,  but  the  small  amount  of  this  coating  in  each  acorn 
and  the  difficulty  of  separating  it  preclude  the  possibility  of  it  be- 
coming a  profitable  source  of  that  compound. 
