420 
North  American  Conifer  ce. 
( Am.  Jour.  Pharrn. 
I     August,  1696. 
wavy-walled  cells,  which  abounded  in  tannin.  The  endodermis 
was  similar  to  that  of  the  other  species  described  ;  the  transfusion 
tissue  was  copious  and  of  the  usual  character ;  the  fibro- vascular 
bundle  was  double,  and  at  the  exterior  side  of  the  phloem  was  a 
mass  of  thickish-walled  and  lignified  fibres. 
CHEMICAL  COMPOSITION. 
The  specimen  from  which  the  barks  of  the  stem  and  root  were 
taken  was  collected  near  Philadelphia  in  May.  The  moisture,  ash 
and  tannin  were  estimated,  and  the  following  percentage  results 
obtained  : 
Ash  in 
Tannin  in 
Moisture. 
Absolutely 
Absolutely 
Dry  Bark. 
Dry  Bark. 
1 1  '37 
4-98 
i5'4o 
11-32 
6-n 
15 '39 
A  quantity  of  the  tannin  was  prepared  from  the  root  bark  by 
means  of  acetone,  and  purified.  Its  elementary  analysis  yielded  the 
following  percentage  results : 
Carbon  6o*8i 
Hydrogen   6'oo 
There  is  no  doubt  that  this  tannin  is  identical  with  those  obtained 
from  the  other  species  of  Picea,  as  well  as  with  that  from  oak  bark. 
The  percentages  of  hydrogen  found  in  all  the  spruce  tannins 
are  nearly  1  per  cent,  higher  than  the  average  found  in  most  other 
tannins  of  the  oak  bark  group,  but  this  is  accounted  for  by  the 
presence  of  adhering  resin,  which  it  is  almost  impossible  to  sepa- 
rate entirely,  and  which  contains,  in  many  cases,  nearly  twice  as 
much  hydrogen  as  exists  in  the  tannin. 
The  most  important  constituent  of  the  Norway  spruce  is  the 
resin,  known  as  Burgundy  pitch.  The  largest  proportion  of  this 
resin  is  collected  in  Finland,  smaller  quantities  are  produced  in 
southern  Germany  and  Switzerland.  None  was  ever  produced  in 
Burgundy.  It  is  collected  by  making  longitudinal  incisions,  some- 
what after  the  manner  of  turpentine.  The  products  consist  of 
resin,  volatile  oil,  similar  to  oil  of  turpentine,  and  water.    The  resin 
