AmM°ayr;iSrm"}      Volatile  Oil  of  Cicuta  Metadata.  241 
compounds  called  terpenes,  we  might  almost  arrive  at  the  conclu- 
sion that  these  bodies  are  what  we  have  in  this  oil.  Five  cubic  cen- 
timetres of  No.  1  were  shaken  with  10  c.c.  of  a  mixture  of  strong 
sulphuric  acid  and  water  (2  :  1),  to  attempt  to  polymerize  the  ter- 
pene  if  possible.  The  mixture  was  then  distilled  in  a  current  of 
steam,  3  c.c.  of  a  yellow  oil  distilling  over  with  the  water.  This  oil 
was  again  shaken  with  about  10  c.c.  of  a  mixture  of  strong  sul- 
phuric acid  and  water  (4:1),  and  again  distilled  as  above.  The 
,  volume  of  oil  that  distilled  over  was  much  less  than  before.  That 
which  came  over  was  colorless  and  responded  to  the  tests  applied  to 
the  original  fraction,  except  that  its  action  with  nitric  acid  was  not 
violent,  although  the  oil  was  darkened  somewhat  by  the  acid.  Nos. 
I,  2,  4,  5  and  6  were  each  treated  with  an  equal  volume  of  a  strong 
solution  of  sodium  bisulphite  and  agitated  occasionally  during  two 
days,  and  then  allowed  to  stand  for  eighteen  hours.  Upon  careful 
examination,  no  crystals  indicative  of  the  presence  of  either  alde- 
hydes or  ketones  could  be  detected  in  any  of  the  samples.  Com- 
bustions were  now  made  upon  fractions  1,  2,  3  and  4,  in  order  to 
determine  their  chemical  compositions. 
The  results  justify  the  assertion  that  all  are  terpenes,  but  with 
slightly  different  boiling  points.  Vapor  densities  taken  of  portions 
of  No.  2  seemed  to  confirm  this  idea,  at  least  as  far  as  this  fraction 
is  concerned.  As  the  fractions  resembled  one  another  in  so  many 
other  points,  it  was  not  deemed  necessary  to  ascertain  the  vapor 
densities  of  more  than  this  one  fraction. 
The  following  were  the  results  of  the  eight  combustions  which 
were  made  : 
Fraction  I.  Fraction  II. 
Carbon   88  21       87-90  88-30  88*72 
Hydrogen  12-07       11*29  11*40       11  -77 
Fraction  III.  Fraction  IV. 
Carbon  85*84     86-86     87*17  82*46 
Hydrogen  10*91      11*45     10*14  10-33 
The  theoretical  percentages  of  carbon  and  hydrogen  in  the  ter- 
pene  C10H16  are  88  23  and  11-77,  respectively.  It  is  known  to  the 
author  that  the  amounts  of  carbon  found  in  fractions  3  and  4  are 
lower  than  the  truth.  The  wide  range  of  temperature  observed  in 
the  distillation  of  No.  4  tends  to  cause  a  doubt  in  my  mind  as  to  its 
being  a  distinct  fraction.  If  it  were  a  decomposition  product,  as  the 
