^""j^iyTis^ys""' }        Japanese  Oil  of  Peppermint.  3 1 5 
icine."  For  this  small  quantity  one  dollar  was  charged,  and  the  label 
had  printed  on  it  '-''Fook-chang-Tong^''  with  the  name  of  the  seller.  Prof. 
FlUckiger  believed  the  specimen  he  saw  to  be  good  American  or  Eng- 
lish oil,  although  the  dealers  in  San  Francisco  declared  it  to  be  imported 
direct  from  Canton,  which,  of  course,  it  might  have  been.  A  few  drops 
of  this  oil  Prof.  Fliickiger  placed  on  a  glass  slide,  and  in  a  few  hours 
it  yielded  crystals  of  camphor  in  all  respects  similar  to  those  he  had 
observed  in  the  Japanese  oil.  So  far,  then,  as  we  know,  there  is  but 
little  difference  between  these  two  foreign  oils,  Chinese  and  Japanese, 
although  it  is  alleged  that  in  California  the  former  becomes  solid  in 
cold  weather,  while  the  American  or  English  as  a  rule  do  not  alter, 
although  in  some  kinds  of  oil  there  may  be  separated,  when  subjected 
to  cold,  a  portion  of  camphor.  The  following  is  what  appears  on  this 
subject  in  the  "  Pharmacographia,"  by  Professor  Fliickiger  and  Mr.  D. 
Hanbury  : 
"When  oil  of  peppermint  is  cooled  to  4°  C.  it  sometimes  deposits 
colorless  hexagonal  crystals  of  peppermint  camphor  CiQHjg-l-H20, 
called  also  menthol.  This  camphor,  the  deposit  of  which  in  the  oil 
we  have  not  observed,  boils  at  210°  C.  and  possesses  the  color  of  the 
crude  oil.  The  properties  of  menthol  contained  in  oils  of  different 
origin  is  very  variable.  Pure  crystallized  menthol  is  sometimes  found 
in  commerce  under  the  name  of  Chinese  oil  of  peppermint." 
There  can,  therefore,  be  very  little  doubt  that  menthol,  a  solid  Chi- 
nese oil  of  peppermint,  resembles  in  all  its  properties  the  solid  portion 
of  Japanese  oil,  obtained  in  all  probability  by  submitting  the  oil  to  a 
low  temperature,  by  which  all  the  solid  portion  is  obtained.  Nor  can 
it  be  doubted  that  chemically  this  menthol  closely  resembles,  nay,  is  in 
all  respects  the  same  as  the  peppermint  camphor  obtained  from  our  own 
or  American  oil,  and  that  in  fact  both  may  be  named  a  monatomic 
alcohol,  menthylic  alcohol,  or  hydrate  of  menthyl,  being,  as  already 
stated,  represented  by  CjoHjg-f-H20. 
In  connection  with  the  use  of  the  oil  of  peppermint  in  neuralgic 
cases,  I  received  the  following  note  from  Messrs.  Frazer  &  Green,  of 
Glasgow,  which  will  tell  its  own  tale.  I  may  premise  the  note  was 
written  in  consequence  of  receiving  one  of  the  circulars  announcing 
that  this  paper  was  to  be  read  : 
113  Buchanan  Street,  Glasgow,  March  25th,  1875. 
John  Mackay^  Esq.: 
Dear  Sir, — We  had  an  order  some  weeks  since  for  three  bottles  of  medicine, 
which  we  have  now  no  doubt  but  that  it  is  the  Japanese  liquid  oil  of  peppermint. 
