132 
PRESERVATION  OF  VOLATILE  OILS. 
more  certainly  ensure,  this  desirable  result,  if  the  wholesale  drug- 
gists, importer,  or  manufacturer,  should  originally  put  up  the  va- 
rious oils  in  packages  of  bottles  of  small  capacity,  instead  of 
those  of  larger  bulk. 
The  only  method  that  suggests  itself  of  entirely  excluding  air 
from  the  dispensing  vessel,  would  be  to  employ  glass  syringe 
bottles  as  the  containing  vessels ;  the  points  of  the  syringes  to 
rest  in  conical  seats  of  glass  (forming  the  base  or  pedestal,)  and 
to  which  they  should  be  accurately  fitted  by  grinding.  By  this 
arrangement,  moreover,  the  first  tendencies  to  form  sediment 
would  be  checked  or  removed,  by  the  lower  portion  of  the  oils  being 
the  earliest  used.  How  far  this  device  presents  a  practicable  ex- 
pedient, could  perhaps  be  satisfactorily  determined  only  by  actual 
trial.  It  is  hardly  necessary  to  remark  that,  in  any  case,  the 
bottles  should  be  perfectly  dry,  as  water  appears  to  oxidise  the 
oils  quite  as  readily  as  air.  An  incidental  advantage  of  the  use  of 
syringe  bottles  is  the  facility  presented  for  graduation,  whereby 
the  quantity  on  hand  is  directly  indicated,  and  the  necessity  of 
as  intermediate  measure  entirely  avoided. 
In  regard  to  the  action  of  light,  it  has  long  been  recognized 
that  the  volatile  oils  are  much  better  preserved  by  being  kept  in 
a  dark  as  well  as  in  a  cool  place.  As  an  obvious  expedient, 
blackened  or  opaque  bottles  have  been  used,  and  with  very  de- 
cided advantage.  One  inconvenience,  however,  attending  the 
use  of  non-transparent  vessels,  is  the  impossibility  of  observing 
the  condition  of  the  contained  oil  or  other  fluid,— a  matter  some- 
times very  desirable. 
Inasmuch  as  the  orange  rays  of  light  (or  those  of  the  least  re- 
frangible end  of  the  solar  spectrum,)  have  been  found  to  exert 
no  actinic  action,  it  is  thought  that  the  employment  of  glass  bot- 
tles of  this  color  would  present  the  desideratum  of  entirely  pro- 
tecting the  oils  from  the  chemical  influence  of  light,  and  at  the 
same  time  of  allowing  their  amount  and  appearance  to  be  distinctly 
perceived.  Of  course,  all  those  preparations  of  the  essential  oils 
liable  to  change,  such  as  orange-flower  water,  rose  water,  &c, 
would  be  equally  well  shielded,  and  would,  indeed,  be  better  pre- 
served than  by  the  means  usually  employed  to  exclude  light.  The 
means  here  suggested  would  be  equally  advantageous  for  the 
