444 
Aromatic  Waters. 
(  Am.  Jour.  Pharm. 
X  September,  1896. 
ciable  quantities  of  microscopical  fungi,  seven  were  made  according 
to  the  method  of  1890  and  only  one  by  the  pharmacopceial  process 
of  1880.  Hence  there  seems  some  reason  for  the  complaint  that 
the  waters  made  by  the  former  process  do  not  keep  as  well  as  those 
made  by  the  latter  method. 
The  expression  of  strength  of  samples  by  the  terms  "  strong," 
"  faint,"  etc.,  is  so  very  vague  that  the  writer  endeavored  to  find  a 
rational  method  of  estimation  of  quantity  of  volatile  oil  in  the  waters 
under  examination. 
Owing  to  the  complexity  of  the  constitution  of  the  several  oils 
employed,  any  effort  toward  quantitative  chemical  estimation  seemed 
useless,  and  the  writer  turned  his  attention  to  the  physical  separa- 
tion of  the  oil  from  the  water. 
At  first  glance  the  process  seems  simple  and  easy.  It  is  to  ex- 
tract the  oil  from  the  water  by  agitating  with  ether  or  other  suitable 
solvent;  but  difficulty  was  encountered  in  attempts  to  separate  the 
oil  from  the  extraction  solvent,  owing  to  the  tendency  of  volatile 
oils  to  spontaneous  evaporation. 
Taking  a  mixture  of  oil  of  peppermint  and  water  (2  to  1,000)  as 
a  type,  a  large  number  of  attempts  at  quantitative  extraction  were 
made.  As  solvents,  ether,  chloroform,  benzin  and  rhigolene  (B.  P. 
20°  C.)  were  employed,  and  the  separation  of  the  oil  from  the  sol- 
vent was  attempted  by  evaporation  between  30°-40°,  spontaneous 
evaporation  from  various  shaped  vessels,  evaporation  in  closed  ves- 
sels, under  gentle  passage  of  a  dried  current  of  air,  both  at  ordi- 
nary temperature  and  with  refrigeration,  and,  lastly,  suction,  with 
the  passage  of  the  air  over  sulphuric  acid. 
All  showed  loss  of  oil  save  the  process  last  mentioned,  in  which 
there  was  always  excess  of  the  theoretical  weight,  despite  the  total 
exclusion  of  moisture,  with  calcium  chloride,  soda-lime  and  sul- 
phuric acid  and  the  purification  of  solvents  by  redistillation  and 
drying  over  exsiccated  copper  sulphate  or  metallic  sodium,  as  occa- 
sion demanded.  Accordingly,  after  several  months'  work,  this  line 
was  reluctantly  abandoned,  and  means  of  indirect  estimation  were 
sought. 
In  surveying  the  field  of  volatile  oils,  there  is  one  which  stands 
distinct  by  reason  of  its  simple  composition — one  whose  quantita- 
tive estimation  is  a  matter  of  no  great  difficulty.  This  oil  is  that  of 
gaultheria — methyl  salicylate. 
