394 
Examination  of  Spruce- Gum. 
f  Am.  Jour.  Pharm. 
I       Aug.,  1886. 
"  named  two  species  of  lobelia,  gave  almost  identical  results  and  agreed 
with  those  obtained  by  Dr.  J.  Ofct  with  Procter's  lobeline  (see  Am. 
Jour.  Phak.,  1875,  p.  127),  though  the  author  differs  in  some  respects 
from  Dr.  Ott  in  the  explanation  of  the  effects  observed.     J.  M.  M. 
EXAMINATION  OF  THE  SO-CALLED  SPRUCE-GUM. 
By  ADOLrH  F.  Menges. 
The  so-called  spruce-^um  of  commerce  is  the  balsamic  exudation  of 
Abies  nigra,  Poiret,  the  black  or  double  spruce,  which,  according  to 
Gray,  ocours  in  swamps  and  cold  mountain  woods  from  New  England 
to  Wisconsin  and  northward,  and  southward  along  the  mountains. 
The  source  of  this  commercial  article  was  traced  by  Professor  E.  L. 
Patch  a  few  years  since,1  and  was  then  definitely  referred  to  the  above 
tree,  although  also  stated  that  a  much  smaller  quautity  is  produced  by 
Abies  alba,  Michx.,  the  so-called  white  spruce,  but  none  from  Abies 
canadensis,  Michx.,  or  the  hemlock  spruce,  which  affords  the  officinal 
Canada  pitch  or  hemlock  pitch. 
In  order  to  be  assured  of  the  true  botanical  origin  of  the  substance 
used  in  my  investigation,  some  twigs  and  cones  of  the  tree  affording 
the  so-called  gum  were  obtained  from  Vermont  and  submitted  to 
Professor  William  Trelease,  by  whom  they  were  readily  identified  as 
tha  above-mentioned  Abies  nigra. 
The  method  of  collecting  spruce-gum  has  already  been  quite  accu- 
rately described,2  but  the  following  information  relating  thereto  would 
seem  to  possess  some  interest,  and  for  which  I  am  indebted  to  Mr.  J. 
G.  Rich,  of  Bethel,  Maine,  who  has  been  engaged  in  the  collection  of 
this  substance  for  a  number  of  years.  Mr.  Rich  writes  substantial' y 
as  follows :  Spruce-gum  is  not  obtained  by  puncturing  the  trees, — at 
least,  not  to  any  great  extent;  the  causes  for  the  flow  of  sap  being 
natural  ones,  such  as  a  rotten  knot  or  a  seam  up  and  down  the  tree 
caused  by  extreme  heat  or  cold.  Therefore,  the  gum  does  not  occur 
on  any  particular  part  of  the  tree,  but  is  found  from  the  bottom  to 
the  top  on  such  as  are  injured  or  decayed.  Simply  bruising  the  tree 
will  not  cause  a  flow  of  sap — the  cavity  must  extend  through  the  bark 
and  sap-wood.    This  causes  a  good  flow,  which  is  at  first  transparent 
1  New  Remedies,  January,  1882,  p.  23. 
2  American  Druggist,  October,  1885;  also,  Pharm.  Journal  (London),  1885? 
p.  370. 
