ADecimb^i8a^m-}         Analysis  of  Essential  Oils.  581 
by  mere  fractional  distillation,  and  furthermore,  because  then  the 
fractions  are  sufficiently  pure  to  render  their  identification  by  other 
processes  possible.  To  describe  these  processes  would  be  quite 
beyond  the  limit  of  this  essay  ;  that  which  is  required  for  the  pur- 
pose  is  a  careful  study  of  the  corresponding  literature.  I  restrict 
myself  here  to  giving  a  review  over  the  more  frequently  occurring 
constituents  of  essential  oils,  arranged  according  to  their  boiling 
points  under  ordinary  pressure,  together  with  those  of  their  deriva- 
tives which  are  advantageously  used  for  their  identification. 
Boiling  Point.  Melting  Point. 
2i°           Acetaldehyd                                        .  .  .  — 
Aldehyde  resin    — 
56'5°           Acetone   — 
920           i-Valeraldehyde                                           .  — 
i-Valeriauic  acid   — 
1460           Sty  vol  ,  — 
Styroldibromid     .  '   74°-74'5° 
1510           Methytamylketone   — 
(Oxidation  with  Cr,03)   — 
1 55°- 156°    Pinene    .   — 
Nitrosopinene   1320 
Nitrolpiperidin                        :   Ii8°-ii9° 
Nitrolbenzylamin   I22°-I23° 
i54°-i56°    Fenchene    — 
i-Fenchylalcohol   61 '5°-  620 
i-Fenchylurethane   jo6°-io7° 
i58-5°-i6i°    Camphehe   480-  540 
i-Borneol   2120 
1610           Furfurol   — 
Color  with  aniline  and  acetic  acid   — 
Pyromucic  acid                                      .  .  I32°-I33° 
1670  Myrcene,  d15  =  0*8023 
nD  =  1-4673 
i7o°-i7i°   Methylheptenone   —  ' 
Semicarbazone   I36°-I38° 
I7i°-i72°    Phellandrene   — 
Nitrite   1050 
i730-i76°  p-Cymol   _ 
p-Oxy-i-propylbenzoic  acid   I55°-I56° 
p-i-propenylbenzoic  acid   255°-26o° 
I75°-I76°    Limonene   — 
Tetrabromide  104*5° 
I75°-I76°    Dipentene   — 
Tetrabromid   I24°-I25° 
I750_I77°   Sylvestrene .  .   — 
Benzylnitrolamin   710-  720 
Dichlorhydrate   72° 
