396 
Examination  of  Spruce-  Gum. 
( Am.  Jour.  Pharm. 
1        Aug.,  1886. 
acteristic,  terebiiithinous  and  rather  agreeable  odor,  and  the  specific 
gravity  0.85.  Its  boiling  point  is  160°  C.  (the  mercury  being  entirely 
in  the  vapor).  With  iodine  it  fulminates,  and  in  contact  with  a  mix- 
ture of  nitric  and  sulphuric  acids  it  takes  fire,  thus  evidently  consist- 
ing simply  of  a  terpene  C10H16,  as  was  also  indicated  by  its  boiling 
point.  With  hydrochloric  acid  it  did  not  form,  however,  a  crystalline 
compound,  nor  could  crystals  of  terpin  be  obtained  therefrom  by  the 
usual  process.  The  amount  of  oil  obtained  did  not  suffice  for  an  ex- 
amination of  its  optical  properties.1 
The  aqueous  distillate  from  the  gum,  from  which  the  volatile  oil 
had  been  separated,  had  an  acid  reaction  and  a  somewhat  acetous  odor, 
but  gave  no  reaction  with  ferric  chloride.  It  was  digested  with 
barium  carbonate,  and  the  solution  filtered  and  evaporated,  when  a 
white,  scale-like  residue  was  obtained.  The  salt  was  quite  freely 
soluble  in  water,  and  afforded  white  precipitates  with  silver  nitrate 
and  with  basic  lead  acetate.  When  mixed  with  sulphuric  acid  it  gave 
off  the  odor  of  butyric  acid,  and  when  this  mixture  was  heated  with  a 
little  alcohol  it  developed  the  very  characteristic  odor  of  butyric 
ether.  An  estimation  of  the  barium  was  made,  but  the  salt  had 
absorbed  a  little  carbonic  acid,  and  the  percentage  of  barium  found 
was,  therefore,  a  little  less  than  that  of  barium  butyrate,  with  which 
it  otherwise  appeared  to  agree. 
A  portion  of  the  resin  was  completely  exhausted  with  hot  water  to 
ascertain  the  presence  of  a  bitter  principle.  The  solution  so  obtained 
had  an  acid  reaction,  and  when  evaporated  to  dryness  left  an  amor- 
phous, blackish-brown  residue,  having  a  bitter,  somewhat  acrid  and 
astringent  taste.  When  dissolved  in  water  it  afforded  a  turbid  green- 
ish solution,  which  became  clear  when  heated,  but  gave  no  precipitate 
with  tannin. 
1  It  is  believed  that  this  is  the  first  examination  which  has  been  made  of 
the  volatile  oil  obtained  from  the  so-called  spruce-gum,  and  the  references  to 
this  subject  in  our  liter  iture  are  very  limited.  Mr.  F.  Stearns  (Amer.  Jouen. 
Pharm.,  January,  1859,  p.  29)  states  that  "the  commercial  oils  of  spruce  and 
hemlock  are  one  and  the  same  thing,  and  are  distilled  from  the  bonghs  of 
Abies  canadensis."  The  only  other  notice  relating  to  oil  of  spruce  that  I  have 
been  able  to  find  occurs  as  an  abstract  in  Amer.  Jo  urn.  Phar.,  April,  1844, 
which  has  been  kindly  afforded  me  by  Professor  J.  M.  Maisch.  The  latter 
investigation  was  made  by  Gottschalk,  under  Wohler's  supervision,  and  refers 
to  the  oil  obtained  fr  >m  the  young  twigs  of  Pinus  Abies,  Lin.,  or  the  Norway 
spruce  fir.  That  oil  was  found  to  consist  of  a  terpene,  boiling  at  160°  C, 
and  afforded  likewise  no  solid  compound  with  hydrochloric  acid. — F.  B.  Power. 
