298 
ON  THE  VOLATILE  OIL  OF  MYRCIA  ACRIS. 
reaction ;  the  liquid  assumes  the  consistency  of  thin  honey  and 
a  brown  iodine  color;  odor  scarcely  modified. 
Ethereal  solution  of  iodine  produces  little  spreading ;  the 
mixture  has  at  first  an  iodine  color,  which  changes  through 
brownish  carmine  into  a  bright  yellowish  red,  and  gradually 
assumes  a  browner  tint ;  consistence  after  24  hours,  syrupy ; 
odor  as  before. 
Bromine  produces  a  hissing  noise,  efi'ervescence  and  a  dark 
yellow  resin. 
Ethereal  solution  of  bromine  occasions  spreading  and  a  green- 
ish black  color,  altering  to  blackish  brown,  with  deeper  colored 
streaks,  the  whole  readily  miscible  to  a  pale  brownish  black  thin 
liquid,  which,  after  24  hours  has  the  consistence  of  honey;  odor 
little  altered. 
Nitroprusside  of  copper. — The  color  passes  through  greenish, 
greenish  brown,  and  blackish  brown  into  brown  black ;  the  odor 
remains  unaltered. 
The  sparing  solubility  in  strong  alcohol  and  the  precipitation 
from  the  ethereal  solution  by  alcohol  of  -835  is  a  very  peculiar 
behaviour  of  Oleum  myrciae,  and  its  coloration  by  nitroprusside 
of  copper  appears  to  be  its  most  important  reaction,  it  being,  so 
far  as  known,  the  only  volatile  oil,  which,  during  the  change  of 
color,  has,  for  a  second  or  two,  a  greenish  hue.  Oil  of  cloves 
with  its  violet  and  cherry  red,  and  oil  of  cassia  with  its  hyacin- 
thine  red  coloration,  are  readily  detected,  if  added  in  small 
quantity.  Oil  of  allspice  has  not  been  examined  yet.  The  car- 
bohydrogens  show  their  presence  by  preventing  the  reaction. 
If  Oleum  myrcise  should  become  an  article  of  commerce,  no 
adulteration  could  be  practised  without  the  certainty  of  detection 
by  this  valuable  reagent.  At  my  earliest  opportunity,  I  shall 
likewise  investigate  the  behaviour  of  Oleum  pimentse. 
My  attention  has  been  drawn  to  the  fact,  that  a  well  known 
English  pomatum,  sold  under  the  name  of  Myrtle  Pomatum,  has 
an  odor  closely  analogous  to  this  oil,  which  has  probably  been  de- 
rived from  Myrcia  acris,  De  C,  or  an  allied  species.  This  pomatum 
keeps  well  for  a  long  time  without  becoming  rancid  ;  it  is  possible 
that  this  may  partly  at  least  be  the  result  of  the  flavoring  in- 
gredients. 
