440 
Oil  of  Gauitheria. 
Am  Jour.  Pharm. 
Sept.,  1879. 
supply  of  leaves  is  exhausted.  This  generally  occurs  in  two  or  three 
years. 
The  first  point  in  locating,  after  finding  where  the  plant  grows  plen- 
tifully, is  to  secure  a  stream  of  water  with  enough  fall  to  allow  it  to 
be  carried  to  the  top  of  the  refrigerating  tub.  Under  a  rough  shed 
the  apparatus  is  erected,  consisting  generally  of  an  ordinary  copper 
whiskey  still  with  a  capacity  of  from  two  to  four  hundred  gallons, 
enclosed  in  brick  work,  and  with  the  head  only  projecting.  The  still 
is  connected  with  a  copper  worm,  and  a  cask  or  tub  to  receive  the 
distillate  completes  the  arrangement.  The  process  followed  is  the  one 
generally  used  in  distilling  volatile  oils.  The  leaves  are  placed  in  the 
still,  covered  with  water,  and  heated  by  an  open  fire  beneath.  The 
steam  carrying  the  volatile  oil  passes  through  the  worm,  is  condensed, 
and  the  product  is  collected  in  the  receiving  vessel.  The  oil  settling 
to  the  bottom,  most  of  the  water  is  dipped  out  and  used  again  with  the 
next  lot  of  leaves,  while  the  oil  is  collected  by  means  of  a  tin  separat- 
ing funnel.  The  advantage  of  using  the  same  water  in  each  succeed- 
ing operation  seems  to  be  understood  and  is  in  general  practice. 
The  above  method  is  the  one  nearly  always  followed,  and  the 
amount  of  volatile  oil  obtained  varies  from  *66  per  cent,  to  *8o  per 
cent.  This  is  the  percentage  as  given  to  me  by  a  number  of  manu- 
facturers. From  their  statements  I  believe  the  average  yield  to  be  about 
seven-tenths  of  one  per  cent.  From  certain  facts  given  to  me  by  one 
manufacturer,  I  believe  that  were  a  close  wooden  cask  or  vessel  sub- 
stituted for  the  metallic  still,  and  live  steam  introduced  and  passed 
through  the  leaves,  a  larger  product  would  be  obtained.  This  process 
was  the  only  exception  to  that  usually  followed.  He  made  his  still  of 
heavy  tin  plate  in  place  of  copper ;  this  would  be  of  the  usual  size  and 
shape,  and  one  would  last  five  or  six  months.  He  always  noticed  that 
when  the  still  was  new  and  first  used  the  amount  of  oil  produced  was 
very  large,  and  gradually  and  steadily  grew  less  as  the  still  became 
older.  Finally  he  would  hardly  get  '5  per  cent,  of  oil,  and  would  be 
obliged  to  throw  the  still  aside.  On  examining  it  then  he  would  find  it 
very  much  corroded  and  eaten  away  inside  where  the  steam  and  oil 
came  most  in  contact  with  the  metal.  He  also  noticed  that  a  brown 
spongy  mass  would  collect  in  the  bottom^of  the  receiving  vessel,  and 
that  the  amount  of  this  deposit  seemed  to  be  inversely  in  proportion  to 
the  yield  of  oil.    That  is,  when  the  still  was  new  it  would  be  almost 
