^ecimbeKoJ1'}    Recent  Literature  Relating  to  Pharmacy.  595 
Heine  &  Co.  have  likewise  in  that  way  been  enabled  to  obtain  and 
investigate  the  chemistry  of  the  odorous  constituent  of  jasmin. 
The  artificial  preparation  of  compounds  possessing  a  fragrant 
odor  has  been  cultivated  chiefly  by  the  German  firms  Haarmann  & 
Reimer,  at  Holtzminden  ;  Hansel,  at  Pirna;  Heine  &  Co.  and  Schim- 
mel  &  Co.,  of  Leipzig,  with  the  aid  of  a  number  of  chemists  who 
have  devoted  themselves  to  this  branch  of  investigation.  The 
result  has  been  the  synthetic  production  of  the  odorous  constituents 
of  several  kinds  of  fruit,  of  wintergreen  oil,  bitter  almond,  lilac, 
musk,  woodruff,  heliotrope,  vanilla,  rose,  violet  and  many  others. 
In  several  instances  the  methods  originally  adopted  were  either  too 
costly,  or,  from  some  other  reason,  the  products  were  regarded  with 
too  much  suspicion  to  admit  of  any  real  competition  with  natural 
products ;  but  with  improved  methods  of  production  and  better 
appreciation  of  the  identity  of  the  products  with  those  occurring 
naturally,  a  very  considerable  industry  has  been  created.  Among 
the  odorous  constituents  of  fruit — generally  consisting  of  esters — 
which  are  now  manufactured  on  a  large  scale  are  pear  oil,  acetic 
isoamyl  ester ;  pineapple  oil,  butyric  ethyl  ester,  and  apple  oil,  iso- 
valerianic  isoamyl  ester,  all  extensively  used  for  confectionery  pur- 
poses and  in  making  liqueurs.  Wintergreen  oil,  the  favorite 
American  perfume  of  Ganltheria  procumbens  and  allied  plants,  con- 
tains 90  per  cent,  of  salicylic  methyl  ester,  and  this  artificially  pre- 
pared compound  is  much  used  as  a  substitute  for  the  natural  oik 
Bitter  almond  oil,  or  benzaldehyde,  formed  naturally  from  amyg- 
dalin  by  the  action  of  emulsin,  is  now  produced  from  toluene, 
which  is  first  converted  into  benzal  chloride ;  by  treating  that  pro- 
duct with  water  or  alkalies  it  is  converted  into  benzaldehyde  free 
from  hydrocyanic  acid.  The  separation  of  some  residual  chlorine 
in  this  product  was  successfully  effected  in  1894  by  Heine  &  Co. 
Terpineol,  possessing  the  odor  of  lilac,  obtained  in  1888-91  by 
Wallach  from  turpentine  oil  by  treatment  with  acetic  acid  and  a 
mineral  acid,  was  introduced  into  commerce  by  Haarmann  &  Reimer 
and  Heine  &  Co.  in  1889.  Though  the  odorous  constituent  of 
musk  has  not  been  isolated,  tertiary  butyl  trinitrotoluene — a  yellow- 
ish crystalline  substance  discovered  by  Bauer — has  the  same  odor 
and  is  largely  manufactured  for  use  in  perfumery,  under  a  patent,  in 
Alsace.  Coumarin,  the  chief  odorous  constituent  of  woodruff  [As- 
perula  odorata)  occurs  in  many  plants  ;  formerly  it  was  obtained 
