362  Resin  from  Pinus  Silvestris.  {Amiu™,m*Tm^ 
COMPOSITION  OF  THE  RESIN  FROM  PINUS  SILVES- 
TRIS.1 
By  V.  Shkateloff. 
Owing  to  the  discrepancies  in  the  results  obtained  with  the  resin 
of  Pinus  maritima,  P.  Larix,  and  P.  Abies,  and  the  uncertain 
composition  of  pimaric,  sylvic,  pinic,  and  abietic  acids,  the  author 
has  investigated  the  crystalline  acid  from  the  Russian  resin  ob- 
tained from  Pinus  silvestris,  growing  in  the  Archangel  and  Wologda 
Governments.  In  order  to  remove  the  uncrystallizable  substances, 
the  resin,  ground  fine,  was  extracted  with  alcohol  of  50 — 60  per 
cent.  (Maly,  J.  pr.  Chem.,  lxxxvi,  111),  and  the  residue,  which 
was  much  whiter  than  before,  was  now  treated  with  boiling  spirit ; 
the  filtered  alcohol  solution,  after  remaining  some  time,  becomes 
almost  entirely  converted  into  a  crystalline  mass.  The  crystals 
were  Avashed  with  alcohol  of  85  per  cent,  and  again  recrystal- 
ized.  After  thrice  repeating  this  process,  30  per  cent,  of  a  perfectly 
white  product  was  obtained ;  whereas  on  repeating  the  same  process 
with  a  resin  that  had  been  exposed  to  the  action  of  air  for  one  year, 
only  20  per  cent,  was  obtained.  In  order  to  prevent  this  from 
becoming  yellow  and  oxidizing  in  the  air,  the  operations  have  to  be 
carried  on  as  quickly  as  possible;  finally  a  compound,  melting  at  143°, 
was  obtained.  The  acid,  C40H58O5,  is  insoluble  in  water,  but  easily 
soluble  in  alcohol,  ether,  acetic  acid,  and  liquid  hydrocarbons.  After 
fusion,  it  solidifies  to  an  amorphous,  transparent  mass,  and  when 
heated  above  360°,  a  colorless,  uncrystallizable  distillate  passes  over. 
The  rotatory  power  of  the  alcoholic  solution  was  found,  [a\j  — — 73.59°. 
It  decomposes  alkaline  carbonates  with  liberation  of  carbonic  an- 
hydride, and  the  original  acid  is  re  precipitated  from  the  solution  on 
adding  a  mineral  acid.  By  the  action  of  hydrogen  chloride  on  the 
alcoholic  solution,  the  acid  is  converted  into  an  isomeric  acid  of  the 
same  composition — but  of  different  properties,  as  it  melts  at  159 — 160°, 
and  the  rotatory  power  is  [«]i=  — 92*58°.  From  the  sodium  salt  of 
the  original  acid,  other  salts  of  the  following  composition  were 
obtained:  C20H29AgO3;  (C20H29O3)2Ba+2H2O ;  (C20H29O3)2Ca,  and 
(C20H29O3)2Cu.  The  acid  C40H58O5  appears  to  be  a  partial  anhydride 
of  an  acid  which  gives  the  above  salts,  and  whose  formation  may  be 
represented  as  follows: — C40H58O5-f-H2O  =  2C20II30O3.     The  ethyl 
1J.  Russ.  Chem.  Soc,  1888,  xx,  477—4.85;  reprinted  from  Jour.  Chem.  Soc.}. 
April,  p.  406. 
