330  Distillation  of  Peppermint  Plants.  {^""•juiv'iS^"'" 
steam-tiglit  cover,  and  the  other  charge  being  now  distilled,  the  entire 
amount  of  steam  is  turned  on  in  the  new  one.  The  steam  comes  up 
through  the  perforations  of  the  false  bottom,  and  is  diffused  evenly 
through  the  plants.  The  oil  is  contained  entirely  in  the  minute  cells 
of  the  leaves  and  blossoms.  The  action  of  the  steam  is  two-fold ;  it 
softens  the  tissues  of  the  cells  and  at  the  same  time,  by  its  heat,  causes 
an  expansion  of  the  particles  of  oil,  so  that  they  burst  forth  from  their 
miniature  prisons,  and  are  carried  off  with  the  current  of  steam.  The 
steam,  now  charged  with  the  essential  oil,  upon  reaching  the  top 
escapes  into  the  condensing  apparatus,  where  it  assumes  the  form  of 
oil  and  water.  Separation  takes  place  in  the  receiver  ;  the  water, 
being  heavier,  sinks  to  the  bottom,  and  is  forced  by  the  pressure  from 
within,  upward  and  out  through  the  exterior  pipe  referred  to.  The 
oil  collects  on  the  top  and  is  dipped  off  at  pleasure. 
As  stated,  distillation  can  be  effected  with  three-fold  the  rapidity 
from  the  dry  plants,  for  the  effect  of  drying  is  to  soften  the  plants, 
allowing  a  larger  quantity  to  be  used  for  a  charge,  while  such  large 
charge  can  also  be  distilled  in  one-half  the  time  required  for  a  smaller 
quantity  of  green  plants.  But  many  growers,  fearing  that  a  loss  of 
oil  results  from  drying,  by  diffusion  in  the  atmosphere,  cannot  be  pre- 
vailal  upon  to  bring  their  plants  to  the  distilleries  other  than  in  a 
green  state.  The  extremes  of  difference  I  have  noticed  are  as  follows : 
From  a  charge  of  two  thousand  pounds  of  dry  plants,  well  covered 
with  leaves  and  blossoms,  thoroughly  dried,  I  have  obtained  twenty 
pounds  of  oil  in  thirty  minutes,  an  hourly  rate  of  forty  pounds  of 
oil  and  two  tons  of  plants.  From  a  similar  charge  of  ver\^  coarse 
plants,  with  few  leaves  and  blossoms,  distilled  in  the  green  state,  less- 
than  two  pounds  were  obtained,  requiring  one  hour  for  their  distillation. 
Upon  a  clear  day  in  September,  in  the  middle  of  the  day,  two  loads 
of  plants  were  cut  down  side  by  side  at  the  same  time.  Both  loads 
were  immediately  raked  up  in  the  green  state,  containing  all  the  natu- 
ral juices  of  the  plant,  then  drawn  to  the  scales  and  weighed.  One 
load  was  immediately  distilled,  the  other  load  being  spread  upon  the 
ground  and  dried  for  two  days  in  the  sun.  At  this  time  the  plants 
had  become  freed  from  nearly  every  particle  of  moisture,  the  leaves 
being  so  dry  and  brittle  as  to  break  off  quite  readily  in  handling. 
This  second  load,  which  had  thus  been  dried  in  the  sun  and  open  air, 
was  now  spread  out  in  a  loft  and  exposed  to  a  further  drying  and  the 
action  of  the  atmosphere  for  a  little  over  six  months. 
