^^aSi^'issT™'}   Analytical  Researches  and  Investigations,  159 
The  Volatile  Oil  of  Angelica.  By  M.  Naudin. — ^From  the  fruit  of 
Angelica  Archangelica  by  distillation  with  water  a  volatile  oil  is 
obtained,  which  has  the  specific  gravity  0*872  and  an  agreeable  odor. 
By  exposure  to  the  light  it  soon  becomes  colored  yellow,  and  by 
exposure  to  the  air,  through  absorption  of  oxygen,  becomes  resin ified. 
Under  ordinary  pressure  it  has  no  constant  boiling  jjoint;  it  begins  to 
boil  at  I74°C,,  although  portions  ])ass  over  even  at  330°C.  By 
distillation  in  vacuo  75  per  cent,  of  distillate  is  obtained,  which  under 
a  presure  of  22  millimeters,  boils  at  precisely  87°C.  This  liquid  has 
the  formula  C^oH^g,  and  is  thus  isomeric  with  turpentine  oil,  but  is 
different,  however,  from  all  similarly  composed  hydrocarbons  ;  it  is 
colorless,  has  an  odor  reminding  of  hops,  and  an  injurious  effect  upon 
the  organs  of  respiration  which  is  similar  to  that  produced  by 
fusel  oil.  Its  boiling  point  is  175°C.,  the  specific  gravity  0'833,  and 
coefficient  of  rotation -j- 25°  16^;  the  latter  decreases  constantly  when 
•the  oil  has  been  heated  to  100°C.,  in  a  sealed  glass  tul)e,  until  it 
reaches  a  minimum  of  4-9°  44^  The  liquid  thereby  becomes  thick,  and 
■polymerized  -to  a  hydrocarbon,  resembling  the  /5-isoterebenthenes, 
which  is  already  contained  in  the  crude  angelica  oil,  and  for  which  the 
author  proposes  the  name  of  terebangelene.  By  the  action  of  the  halo- 
gens a  violent  reaction  ensues  with  the  formation  of  cymoX.—Ibid.,  No. 
4,  p.  68,  from  Compt  Rend.,  93,  p.  1146. 
The  Detection  of  Small  Amounts  of  Iodoform  and  Substances  yield- 
ing Iodoform. — On  heating  an  alkaline  solution  of  resorcin  with  even 
very  small  amounts  of  iodoform  a  red  coloration  is  produced,  which 
again  disappears  on  the  addition  of  an  acid.  This  reaction  may  be 
readily  employed  for  the  detection  of  small  amounts  of  substances 
yielding  iodoform,  as  alcohol,  acetone,  etc.  As  is  known  such  sub- 
stances are  recognized  by  warming  the  liquid  to  be  examined,  adding 
a  solution  of  iodine  in  potassium  iodide  or  potassium  carbonate,  and 
then  sufficient  solution  of  sodium  hydrate,  drop  by  drop,  until  the 
brownish-yellow  color  is  nearly  discharged.  On  agitation  and  stand- 
ing, the  iodoform,  separates  as  a  bright  yellow  crystalline  precipitate, 
which,  under  the  microscope,  appears  in  the  form  of  regular  six-sided 
tables  or  roundly-pointed  lamina?.  As  on  the  one  hand  small  amounts 
of  iodoform  remain  dissolved,  particularly  in  alcoholic  liquids,  and  on 
the  other  hand  tlie  microsco[)ic  examination  of  the  precipitate  is  some- 
what circumstantial,  it  is  recommended  to  gently  wai-ni  the  liquid  con- 
taining iodoform,  obtained  by  the  above  nuithod,  with  the  furtlicr  ad- 
I 
