594       Recent  Literature  Relating  to  Pharmacy.  {ADe'cimbe^i9oom' 
emodin  also  forms  a  benzoyl  compound  melting  at  23 50  C,  and*  a 
propionyl  derivative  melting  at  1520  to  I53°C.  Frangula-emodin 
melts  at  2500,  gives  a  concentrated  sulphuric  acid  solution  that 
becomes  blue  on  dilution  with  water,  and  cherry  red  on  saturating 
with  ammonia.  The  emodin  turns  cherry  red  with  baryta  water, 
and  gives  a  benzoyl  compound  melting  at  2250  C,  and  a  propionyl 
compound  melting  at  121 0  to  1 220  C.  A  more  exact  differentiation 
between  these  emodins  and  that  from  rhubarb  is  being  studied. — 
(O.  A.  Oesterle,  Schw.  Woch.  Ch.  und  Ph.,  1900,  45.) 
H.  V.  A. 
PERFUMES — NATURAL  AND  ARTIFICIAL. 
Though  the  proceedings  at  the  annual  meetings  of  the  German 
Apotheker-Verein  are  chiefly  directed  to  the  discussion  of  pharma- 
ceutical affairs,  arrangement  is  generally  made  for  affording  an 
agreeable  relief  from  the  fatigue  o\  the  debates  by  the  delivery,  on 
one  or  both  days  of  meeting,  of  an  address  on  some  subject  of  gen- 
eral scientific  interest.  This  year,  at  the  Stuttgart  meeting,  one  of 
the  addresses  was  delivered  by  Professor  Schmidt,  of  that  town,  on 
the  very  interesting  subject  of  perfumes,  in  which  he  not  only  gave 
a  general  description  of  present  knowledge  as  to  the  chemistry  of 
perfumes  as  they  occur  naturally  and  for  the  most  part  as  constitu- 
ents of  plants,  as  well  as  a  sketch  of  the  ordinary  methods  of 
extracting  essential  oils  and  the  other  odorous  constituents  that  are 
used  in  perfumery,  but  also  an  account  of  the  more  recent  chemical 
discoveries  which  have  led  to  the  synthetical  production  of  odorous 
substances  upon  a  manufacturing  scale  of  such  magnitude  and  im- 
portance as  to  have  suggested  for  the  title  of  the  address  "  The 
Competition  Between  Chemical  Industry  and  Nature  in  the  Produc- 
tion of  Odorous  Materials."  Within  recent  years  the  improvement 
in  the  extraction  of  essential  oils  from  various  plants  has  been  very 
considerable,  and  German  manufacturers  have  been  conspicuous  in 
this  respect  by  the  adoption  of  vacuum  stills  of  immense  capacity 
— from  30,000  to  60,000  litres.  By  means  of  such  improved  appli- 
ances the  possibility  of  extracting  essential  oils  from  materials  con- 
taining only  a  very  small  amount  has  been  so  extended  that,  for 
instance,  H.  Hansel,  of  Pirna,  shows  at  the  Paris  Exhibition  a  flask 
containing  100  grammes  of  solid  oil  of  lime  blossom  of  the  value 
of  £50,  or  about  fifteen  times  as  much  as  that  of  otto  of  rose. 
