Am.  Jour.  Pharm.  ) 
Sept.  1,  1874.  J 
The  Vanilla. 
417 
acquires  an  acid  reaction,  nitrous  and  nitric  acid  being  formed,  after 
which  valerianic  acid  and  amylic  valerianate  appear ;  amylic  alcohol 
is  likewise  found  among  the  products  of  decomposition,  but  hydro- 
cyanic acid  could  not  be  detected.  Moisture  does  not  prevent  the 
decomposition,  and  the  author  suggests  to  preserve  the  amylic  nitrite 
by  the  addition  of  a  little  fused  pure  chloride  of  calcium  and  calcined 
magnesia. 
E.  Rennard  likewise  rejects  the  use  of  nitric  acid  in  preparing  this 
nitrite,  and  recommends  the  employment  of  nitrous  acid  ;  he  gives 
*877  as  the  specific  gravity  of  amylic  nitrite,  which,  however,  accord- 
ing to  Hilger  is  not  correct. — Ar'cliiv  d.  Ph.,  1874,  June,  485-489. 
Mercuric  Oleate. —  Prof.  Hilger  found  that  precipitated  and  rapidly 
dried  mercuric  oxid  is  easily  dissolved  in  oleic  acid  at  a  temperature 
not  exceeding  60°  or  70°  C.  ;  a  higher  temperature  causes  decompo- 
sition of  the  acid  and  separation  of  mercury.  With  15  or  16  per  cent, 
of  mercuric  oxide  the  oleate  constitutes  a  thick  liquid  ;  with  more 
•oxide  it  becomes  solid.  A  solution  of  30  per  cent,  mercuric  oxide 
in  oleic  acid  is  possible  under  the  above  precautions  ;  a  larger  quantity 
causes  decomposition.  Chemically  pure  oleate  of  mercury  could  not 
be  obtained  by  double  decomposition  of  either  aqueous  or  alcoholic 
solutions.  To  obtain  the  oleate  of  a  firmer  consistence,  the  author 
recommends  the  addition  of  a  little  palmitic  or  stearic  to  the  oleic 
acid.— Ifo'd.,  490-493. 
Decoction  of  Salep  is  best  prepared  and  the  formation  of  lumps 
completely  avoided,  if  the  powdered  salep  is  first  moistened  with  a 
few  drops  of  alcohol,  before  it  is  submitted  to  the  action  of  water. — 
Depaifve  in  Jour,  de  Phar.  a"  Anvers,  1874,  p.  264. 
THE  VANILLA.* 
The  vanilla  is  remarkable  for  its  climing  habit,  which  is  not  com- 
mon among  orchids.  There  are  several  species,  most  of  which 
are  natives  of  the  hot  and  damp  regions  of  South  and  Central  Amer- 
ica ;  the  genus  is  also  represented  in  tropical  Asia  and  Africa.  The 
stems  climb  to  the  height  of  twenty  or  thirty  feet,  twining  round  the 
trunks  of  trees,  and  throwing  out  a  profusion  of  aerial  roots,  some  of 
which  eventually  reach  the  ground,  as  is  the  case  with  the  banyan, 
From  the  Gardener's  Chronicle  for  May  23d,  1874. 
26 
