340 
Investigation  of  the  Tannins. 
Am.  Jour.  Pharm. 
July,  1900. 
situated  about  three  to  four  miles  northwest  of  Media,  Pa.  The 
bark  was  taken  from  the  "  knees;"  it  peeled  easily.  An  estimation 
revealed  the  following  quantities  : 
Per  Cent. 
Moisture  13- 17 
Ash  in  absolutely  dry  bark  4-20 
Tannin  in  absolutely  dry  bark  ."  10*45 
Juniperus  Communis. — A  nursery  sample  of  Juniperus  communis 
obtained  near  Philadelphia  on  March  15,  1896,  showed  the  following 
percentages  of  tannin  : 
Ash  in  Tannin  in 
Absolutely  Absolutely 
Moisture.         Dry  Material.     Dry  Material. 
Root  bark  5*97  677  771 
Stem  bark  5-95  6-49  5*66 
Leaves  6*21  4*18  4'i8 
The  ashes  of  the  barks  contained  potassium  and  calcium  as  carbo- 
nates, phosphates  and  sulphates  ;  the  ashes  of  the  leaves  were  free 
from  sulphates,  but  in  other  respects  they  were  the  same  as  those 
from  the  barks. 
Juniperus  Virginiana. — The  following  collections  of  the  stem  bark 
of  Juniperus  virginiana  were  made  at  St.  David's,  Pa. 
Date  of  Collection. 
May  12,  1894  . 
June  17, 1894  . 
July  29,  1894  . 
August  28,  1894 
October  3,  1894 
December  3,  1894 
January  14,  1895 
February  25,  1895 
Moisture. 
5  '50 
8-64 
25-28 
25-27 
8-24 
II'IO 
9"oo 
7-5i 
Ash  in 
Absolutely 
Dry  Bark. 
5'30 
6  30 
6  86 
7-48 
4*06 
9-90 
978 
7'57 
Tannin  in 
Absolutely 
Dry  Bark. 
5-60 
7'30 
8-28 
8-59 
3 '59 
3'93 
3  56 
2-05 
Inner  bark. 
The  purified  tannin  of  this  bark  gave  the  qualitative  reactions  of 
oak-tannin,  and  showed  a  composition  of: 
Per  Cent. 
Carbon  .  .  .  60*87 
Hydrogen  •   5 '47 
Oxygen   33 '66 
Larix  Americana. — On  August  1 5, 1895,  Professor  Bastin  gathered 
