570  Iodine  Absorption  of  Essential  Oils.  {Am-^;1f£frm- 
but  a  few  millions  of  the  population,  who  consume  the  22^  million 
pounds. 
The  import  of  opium  into  the  United  Kingdom  has  been  declining 
the  last  few  years.  In  1885,  the  imports  were  710,100  lbs.;  in 
1889,  they  had  dropped  to  492,115  lbs.  Of  last  year's  imports  the 
great  bulk,  425,255  lbs.,  was  received  from  Turkey  and  19,570  lbs. 
from  Persia.  Of  the  imports  of  opium  in  1889,  409,738  lbs.  were 
re-exported,  leaving  82,377  lbs.  for  home  consumption,  which  is 
about  twice  the  quantity  used  in  1 850. 
THE  IODINE  ABSORPTION  OF  ESSENTIAL  OILS  AS  A 
CRITERION  OF  PURITY. 
A  Volunteer  Paper. 
By  H.  W.  Snow,  Ph.C. 
Read  at  Meeting  of  the  Michigan  State  Pharmaceutical  Association,  September,  1890. 
In  the  "  New  Idea  "  for  March,  1889,  p.  19,  the  writer  presented 
the  results  of  some  work  performed  on  the  absorption  of  iodine  by 
essential  oils.  The  work  included  the  examinations  of  twenty-one 
essential  oils  and  three  stearoptens.  These  results  were  meagre,  but 
interesting,  and  at  that  time  no  similar  work  had  appeared  in  English. 
Unknown  to  the  writer,  however,  Mr.  C.  Barenthin  had  published, 
in  the  Archiv  der  Pharm.,  for  October,  1886,  the  results  of  determi- 
nations for  eighteen  oils,  though  no  translation  had  appeared  in 
English.  The  next  month,  Mr.  R.  H.  Davies  published  an  interest- 
ing paper  on  the  same  subject,  giving  the  results  of  determinations 
of  twenty-nine  essential  oils  and  four  stearoptens.  Mr.  Davies  was 
likewise  unaware  of  the  work  done  by  previous  investigators,  though 
he  afterwards  traced  the  work  of  the  German  pharmacist,  and  was 
able  to  compare  it  with  his  own.  Six  months  later,  Mr.  Rowland 
Williams,  strange  to  say,  wholly  unaware  of  the  work  done  by 
pharmacists,  notwithstanding  the  discussion  it  had  created  in  his 
own  country,  gave  in  the  Chem.  News,  October  11,  1889,  p.  175, 
the  results  of  his  own  work,  saying  :  "  To  the  best  of  my  knowl- 
edge, this  test  has  never  before  been  applied  to  essential  oils."  Four 
papers  have  therefore  appeared  on  this  subject,  and  it  is  the  object 
of  this  one  to  compare  the  work  of  the  different  investigators,  to 
add  some  further  results  obtained  by  the  writer,  and  to  draw  such 
conclusions  as  seem  to  be  warranted  from  its  present  status.  The 
