Am.  Jour.  Pharm."! 
February,  1897.  J 
North  American  Coniferce. 
91 
color  and  it  possessed  the  characteristic  odor  of  hemlock.  The 
specific  gravity  of  the  dried  oil  at  20°  C.  was  0-9288,  [«]D  =  — 
18-399°  at  the  same  temperature.  His  conclusion  was  that  this  oil 
of  hemlock  was  very  similar  in  composition  to  that  examined  by 
Bertram  and  Walbaum,  and  also  to  the  oil  of  black  spruce,  Picea 
nigra,  previously  examined  by  himself. 
Our  own  experiments  on  the  leaves  have  been  limited  to  an  esti- 
mation of  the  tannin,  resin  and  ash.  For  this  work  the  leaves  were 
collected  in  November,  and,  after  a  short  exposure  to  dry  air,  were 
found  to  still  contain  12-80  per  cent,  of  moisture.  The  ash  esti- 
mated on  absolutely  dry  substance  was  found  to  be  3-78  per  cent., 
and  tannin,  similarly  calculated,  amounted  to  1-48  per  cent.  The 
ash  contained  calcium  and  potassium  sulphates,  phosphates  and 
traces  of  carbonates  and  chlorides.  The  leaves  submitted  to  the 
action  of  absolute  alcohol  yielded  22-97  per  cent,  of  their  weight  to 
that  solvent.  From  the  residual  extract,  after  recovery  of  the  alco- 
hol, petroleum  ether  removed  5-83  per  cent,  of  the  weight  of  the 
leaves,  consisting  of  fat,  volatile  oil,  wax,  chlorophyll  and  resin. 
Water  then  removed  from  the  residual  alcohol  extract  14-70  per 
cent,  of  the  weight  of  the  leaves,  which  consisted  of  tannin,  sugar 
and  extractive,  leaving  2-44  per  cent,  of  resinous  matter  and  chlo- 
rophyll. 
The  Root  Bark. — This  portion  of  the  hemlock  was  collected  for 
examination  on  the  first  day  of  August,  and  yielded  the  following 
results : 
This  large  amount  of  tannin  was  equivalent  to  21-57  per  cent,  in 
the  air-dry  sample. 
The  Trunk. — The  wood  portion  of  the  hemlock  tree  supplies  the 
chief  amount  of  the  resin,  which  is  found  in  commerce  under  the 
name  of  Canadian  pitch. 
Probably  the  first  pharmaceutical  literature  concerning  this  resin 
was  by  Charles  Ellis,1  in  1 830,  and  the  full  title  of  the  paper,  as 
1  "Pinus  Canadensis,  Willd.;  Abies  Canadensis,  Mich.  Sylv.  A  large  tree 
belonging  to  the  natural  order  Coniferae,  Monoecia,  Monodelphia  of  Iyinnaeus. 
Officinal  Resin  Pini  Canadensis.  Hemlock  Resin.  By  Charles  Ellis."  Jour- 
nal of  the  Philadelphia  College  of  Pharmacy,  Vol.  2,  p.  18. 
Per  Cent. 
Moisture  
Ash  in  dry  bark 
Tannin  in  dry  bark 
11-83 
3'96 
24-46 
