AmOc°tUri921larm"  }  °f  C(lde  719 
oil  may  be  as  low  as  0.955.  The  limits  given  in  the  United  States 
Pharmacopoeia  are  0.980  to  1.055  at  25°>  and  up  to  the  last  few 
years  most  commercial  samples  have  fallen  within  these  limits.  It 
seems,  however,  that  the  minimum  figure  will  have  to  be  lowered. 
Possibly  the  variation  is  due  to  the  method  of  distillation  and  the 
amount  of  tar  present  in  the  oil. 
Genuine  cade  oil  must  be  derived  exclusively  from  the  wood 
of  Juniperus  oxycedrus  by  dry  distillation.  Juniperus  oxycedrus  is 
a  bushy  shrub,  differing  from  the  other  Juniper  species  by  the  simul- 
taneous occurrence  of  needle-shaped  leaves  and  of  fruits  which  are 
orange-red  when  ripe.  It  grows  on  a  chalky  marly  soil,  and  thrives 
best  in  a  southern  aspect.  It  occurs  abundantly  in  the  wild  state  in 
Provence  and  in  the  waste  lands  of  Sommeres  and  Lussan.  The 
woodcutters  distinguish  two  kinds  of  wood,  "cades  gras"  and  "cades 
maigres" ;  only  the  former  is  used  for  distillation,  the  latter  serving! 
as  fuel.  The  heart-wood  is  richest  in  oil,  and  the  oil-content  is  said 
to  increase  towards  the  roots.  For  the  purpose  of  distillation  the 
bark  is  removed  and  the  wood  is  then  cut  as  small  as  possible.  The 
preparation  of  the  wood  is  very  important,  as  the  yield  of  oil  is 
much  greater  from  shavings  than  from  larger  chips.  The  distilla- 
tion is  carried  on  throughout  the  year,  but  preferably  from  Sep- 
tember to  May. 
According  to  Pepin  ("Recherches  sur  l'Huile  de  Cade  Vraie," 
Paris,  1908)  the  oil  is  obtained  by  two  methods  in  France — "dis- 
tillatio  per  descensum"  and  by  "combustion  en  milieu  confine."  The 
former  method  is  used  only  in  the  manufacture  on  a  small  scale.  AS 
cast-iron  boiler  is  filled  with  shavings,  then  turned  upside  down  on 
to  its  cover  or  a  hollowed-out  stone  slab,  and  cemented  up.  In  the 
centre  of  the  bottom  is  a  hole,  which  is  connected  with  a  delivery 
tube.  A  brisk  fire  is  lighted  so  that  the  boiler  is  surrounded  by  the 
flames.  Distillation  commences  with  evolution  of  thick  vapors,  and 
soon  afterwards  a  blackish  viscid  liquid  flows  off.  The  process 
lasts  from  half  an  hour  to  several  hours,  according  to  the  quantity  of 
wood.  In  place  of  a  boiler  a  pit  is  sometimes  used,  with  a  stone  slab 
at  the  bottom  provided  with  a  delivery  pipe.  The  chips  are  heaped! 
up  in  fhe  centre  of  the  cavity  and  covered  over  with  bricks,  which 
are  luted  together  with  clay.  The  rest  of  the  pit  is  used  for  firing 
material. 
