164 
On  Peppermint  Oil 
/  Am.  Joub.  Pharm. 
\    April  1, 1871. 
respect  to  brightness  and  fire,  does  not  sustain  comparison  with  the 
latter ;  therefore,  the  latter  constantly  gains  more  ground.  The  dif- 
ferent shades,  from  a  deep  red  almost^to  an  almost  light  orange,  are 
simplj  a  consequence  of  the  size  of  the  crystals  ;  the  larger  the 
crystals,  the  deeper  the  color,  and  vice  versa^  so  that  large  crystals 
resemble,  in  their  cochineal  color,  the  native  cinnabar. 
Until  a  few  years  ago,  all  the  Vermillion  used  in  the  United  States 
was  imported  mostly  from  Europe,  and  some  from  China,  but  now 
our  own  manufacturers  have  defeated  foreign  competition,  when  taking 
into  account  the  high  price  of  labor,  kc.  The  protection  by  duty  is 
very  small,  but  not  only  have  our  manufacturers  successfully  com- 
peted with  Europe,  but  they  have  even  reduced  the  price  considerably, 
thereby  again  increasing  the  use  of  their  product.  It  may  be  safe  to 
say,  that  the  annual  production  in  America  amounts  to  500,000  lbs., 
and  may,  before  long,* reach  1,000,000  lbs.  The  precarious  condition 
of  the  California  mercury  mines  may  place  our  manufacturers  in  a 
dangerous  position,  compelling  them  to  obtain  their  supply  of  mer- 
cury from  Spain,  at  a  greatly  increased  cost.  Already,  within  the 
last  six  months,  the  price  of  mercury  has  risen  fully  35  per  cent.,' 
and,  as  the  mercury  trade  is  a  monopoly,  it  may  go  higher  still. — 
Olmnical  News^  Lo7ido7i,  Fehmary  llthj  1870,  from  the  American 
Chemist. 
MAGNIFICENT  FLUORESCENCE  OF  PEPPERMINT  OIL. 
By  Professor  Flucktger. 
50  to  70  drops  of  peppermint  oil  shaken  with  one  drop  of  nitric 
acid,  about  1-2  sp.  gr.,  turn  faintly  yellowish,  brownish,  and,  after  an 
hour  or  two,  exhibit  a  most  beautiful  blue-violet,  or  greenish- blue 
color,  when  examined  in  transparent  light.  When  observed  in  re- 
flected light,  the  liquid  is  of  a  copper  color,  and  not  transparent.  If 
the  mixture  is  warmed,  the  green  or  blue  coloration  takes  place 
speediij^  ;  it  may  also  be  immediately  provoked  by  adding  a  greater 
amount  of  nitric  acid,  say  1  drop  to  19,  or  9  drops  of  the  essential 
oil. 
Bisulphide  of  carbon  contributes  in  no  way  to  improve  the  test. 
All  the  various  specimens  of  peppermint  oil  at  my  command  show  the 
same  behavior,  but  the  blue  or  greenish-blue  hue  exhibits  very  appre- 
ciable differences,  which  ought  to  be  further  examined  by  chemists 
