606  Medicinal  Plants  at  Hitchin.  {Am^x^m 
Mr.  Ransom  produces  at  his  extensive  laboratory  a  very  large  num- 
ber of  extracts,  essential  oils  and  liquors,  and  many  of  these  in  very 
large  quantity,  using  as  much  as  40  tons  of  dandelion  root  per  annum. 
Some  of  the  extracts  are  such  as  are  rarely  asked  for  in  retail  shops, 
but  for  which  there  must  be  local  demands.  Among  these  were  notice- 
able the  extracts  of  sarsaparilla,  Actcea  racemosa,  Ghelidonium  majus, 
Datura  Tatula,  Saponaria  officinalis,  wormwood  (Artemisia  Absinthium), 
angelica  (Arcbangelica  officinalis),  centaury  [Erythrcea  Centaurium), 
Pulsatilla  [Anemone  Pulsatilla),  blessed  thistle  (Carduus  benedictus),  wal- 
nut (Juglans  regia),  white  horehound  [Marrubium  vulgare),  buckbean 
(Menyanthes  trifoliata),  St.  Ignatius'  bean  (Strychnos  amara),  senega,  and 
the  alcoholic  extract  of  belladonna  and  ipecacuanha.  The  extract  of 
Ignatius'  bean  is  used  for  epilepsy  and  goes  chiefly  to  Australia  and 
China.  To  give  an  idea  of  the  extent  to  which  some  of  these  uncom- 
mon extracts  are  used,  it  may  be  stated  that  as  much  as  thirty  or  forty 
pounds  of  extract  of  Ignatia  amara  is  turned  out  annually.  All  these 
extracts  are  made  in  steam  evaporating  pans,  the  juice  being  in  many 
cases  expressed  from  the  plants  or  roots  under  an  hydraulic  pressure  of 
300  tons. 
A  prominent  feature  in  the  laboratory  is  the  apparatus  for  making 
scammony  resin  from  the  root.  This  is  obtained  by  percolating  hot 
spirit  through  the  powdered  root.  As  expression  of  the  root  after  per- 
colation would  involve  considerable  loss,  and  the  last  portion  of  spirit 
has  to  be  displaced  with  water,  considerable  trouble  has  to  be  taken  in 
freeing  the  resin  from  aqueous  extract.  In  dissolving  the  resin  of 
scammony  of  commerce  in  ether  a  small  amount  of  insoluble  matter 
will  often  be  found,  which  is  probably  matter  of  this  kind.  Economy 
of  fuel  is  provided  for  as  far  as  possible  by  causing  the  hot  water  from 
the  steam  pans,  etc.,  to  pass  into  a  large  tank  from  which  it  is  pumped 
by  the  engine  into  the  boiler,  etc.,  as  required.  The  latest  improve- 
ments have  been  adopted,  even  to  the  use  of  a  patent  for  preventing 
the  escape  of  steam  while  allowing  the  hot  water  to  escape. 
In  conclusion,  one  word  of  caution  is  necessary  to  those  who  may 
feel  inclined  to  visit  Hitchin.  The  lavender  fields  are  a  sight  well 
worth  seeing  when  in  full  flower  ;  the  handsome  red  admiral  [Vanessa 
atalanta),  the  tortoiseshell  (V.  urticte),  the  gorgeous  peacock  [V.  Io), 
the  brimstone  (Gonepteryx  rhamni),  and  even  the  clouded  yellow  butter- 
fly (Colias  edusa),  as  well  as  many  commoner  species,  are  to  be  seen  in 
