540 
Laboratory  Notes. 
Am.  Jour.  Pharm. 
Nov.,  1886. 
shape.  Some  of  the  commercial  menthol  pencils  consist  of  pure  men- 
thol, melt  at  44°  C,  are  freely  and  completely  soluble  in  hot  alcohol, 
chloroform,  ether,  carbon  bisulphide  and  oil  of  peppermint,  and  on 
being  gently  heated  are  completely  volatilized.  Wm.  G.  JNebig,  Ph. 
G.,  has  found  the  pencils  of  three  manufacturers  to  be  always  of  this 
behavior,  and  to  consist  of  pure  menthol. 
The  product  of  four  other  manufacturers  contained  between  30'5 
and  69*25  per  cent,  of  paraffin,  began  to  melt  between  39°  and  41  °C, 
and  was  completely  liquefied  at  from  43°  to  59°  C.  These  cones 
were  soluble  in  benzin,  benzol,  carbon  bisulphide,  chloroform  and  fixed 
oils ;  also  in  boiling  alcohol,  a  white  mass  being  deposited  on  cooling. 
The  cones  from  another  manufacturer,  No.  8,  after  having  been 
repeatedly  treated  with  hot  chloroform,  left  behind  a  white  crystalline 
powder,  which  was  inodorous,  very  bitter,  of  neutral  reaction,  soluble 
in  water  and  alcohol,  and  with  strong  sulphuric  acid  turned  blood- 
red,  showing  it  to  be  salicin,  amounting  to  37  per  cent. 
Occasionally  the  cones  of  the  last  five  manufacturers  were  found  to 
consist  of  pure  or  nearly  pure  menthol ;  this  is  attributed  to  the  low 
melting  point  of  menthol,  and  to  the  difficulty  of  uniformly  mixing 
large  amounts  of  it  with  the  other  substances,  owing  to  the  volatility 
of  the  former. 
Fuchsin  was  recommended  by  H.  Zeise  (see  Am.  Jour.  Phar., 
1867,  p.  320)  as  a  test  for  the  presence  of  alcohol  in  certain  volatile 
oils.  Jas.  P.  Mallon,  Ph.  G.,  has  examined  the  behavior  of  aniline 
red  to  the  volatile  oils  of  bergamot,  cajeput,  caraway,  cinnamon,  cit- 
ronella,  cloves,  coriander,  cubeb,  juniper,  lavender,  lemon,  myrcia, 
neroli,  pennyro}7al,  peppermint  and  sassafras,  and  found  it  to  be  soluble 
in  all  the  oils  named  in  sufficient  quantity  to  communicate  its  color. 
The  oil  of  peppermint  had  been  recently  distilled  and  was  known  to 
be  pure;  it  was  freed  from  water  by  treatment  with  calcium  chloride 
and  rectification,  when  it  was  not  colored  by  aniline  red,  but  in  about 
twenty  minutes  this  was  seen  to  become  soluble  in  the  presence  of  1 
per  cent,  of  alcohol;  in  the  presence  of  5  per  cent,  or  more  of  alcohol 
the  oil  at  once  became  pink  and  rapidly  of  a  deeper  color. 
The  effect  of  dehydration  and  rectification  was  not  tried  with  the 
other  oils  mentioned  above.  It  may  be  noted  here  that  Zeise  found 
the  oils  of  cubeb  and  sassafras,  among  several  others,  to  be  unaffected 
by  fuchsin,  and  that  these  and  other  oils  tested  had  been  prepared  by 
himself. 
