Am.  Jour.  Pnarm. 
July,  1900. 
Investigation  of  the  Tannins. 
341 
some  bark  from  the  branches  of  a  Larix  americana,  growing  in  the 
Adirondack  Mountains,  New  York.  This  was  examined  and  found 
to  yield  9/37  per  cent,  of  moisture;  2-56  per  cent,  of  ash  in  abso- 
lutely dry  bark ;  and  13*98  per  cent,  of  tannin  in  the  thoroughly 
dried  material. 
A  sample  of  bark  collected  from  the  branches  by  Professor 
Trimble  at  St.  David's,  Pa.,  on  July  29,  1895,  showed  moisture,  13  05; 
ash  in  absolutely  dry  bark,  2*78,  and  tannin  in  absolutely  dry  bark, 
8-79  per  cent. 
A  nursery  sample  of  the  tree  estimated  in  March,  1896,  gave  the 
following  results  : 
Ash  in  Tannin  in 
Absolutely  -Absolutely 
Moisture.         Dry  Material.       Dry  Material. 
Rootbark  8'8i  4'ii  i5'5o 
'  -  Stem  bark  7*47  2*51  12*48 
Leaves  6-51  573  8-89 
Latix  Europea. — Some  bark  of  Larix  europea  was  collected  from 
the  stem  of  a  tree  at  St.  David's,  Pa.,  on  January  30,  1896.  It 
showed  the  following  : 
Per  Cent. 
Moisture  575 
Ash  in  absolutely  dry  bark  2*39 
Tannin  in  absolutely  dry  bark  15*91 
Pseudotsuga  Taxifolia. — Two  samples  of  the  bark  of  Pseudotsuga 
taxifolia  were  estimated.  One  of  these  samples  was  from  Klamath 
Falls,  Ore.,  and  the  other  from  Forest  Grove,  in  the  same  State. 
The  former  was  collected  about  the  first  of  January,  1897,  and  the 
latter  on  February  13,  1895.    The  results  were  as  follows: 
Ash  in  Tannin  in 
Absolutely  Absolutely 
Sample.                                                   Moisture.      Dry  Bark.  Dry  Bark. 
Klamath  Falls  15 '41             1*06  8*15 
-Forest  Grove  5*34            1*49  14*05 
The  purified  tannin  from  one  of  the  samples  gave  the  following 
figures  when  submitted  to  combustion : 
Per  Cent. 
Carbon   .  6172 
Hydrogen  5  73 
Oxygen  3255 
Pinus  Ponderosa. — Two  samples  of  the  bark  of  Pinus  ponderosa, 
one  from  Klamath  Falls,  Ore.,  and  the  other  from  Colorado  Springs 
