THE  COMPASS  PLANT. 
37 
served  in  the  manner  I  am  about  to  mention,  but  it  is  quite  cer- 
tain that  in  very  many  it  is  not ;  and  they  either  follow  one  of 
the  above  practices,  or  make  the  necessary  delay  of  procuring 
and  pressing  lemons,  and  straining  the  juice  when  required. 
The  process  Mr.  Alsop  recommends,  and  Dr.  Redwood  has 
frequently  advocated  for  the  preservation  of  infusions,  applies 
equally  to  lemon-juice,— viz. :  heating  to  the  boiling-point,  and 
excluding  the  air  by  carefully  closing  the  full  bottles  at  this 
temperature.  Thus  prepared  it  keeps  well  for  more  than  twelve 
months,  but  early  last  winter  I  made  some  experiments  to  as- 
certain if  ebullition  were  really  necessary,  and  I  find  it  is  not ; 
juice  heated  only  to  150°  and  excluded  from  the  air  at  that 
temperature,  is  now  in  a  perfect  state  of  preservation.  I  cannot 
say,  however,  that  this  holds  good  if  it  be  bottled  during  the 
summer  months ;  in  fact,  my  experience  indicates  otherwise. 
This  might  arise  from  the  juice,  when  expressed,  being  in  an 
incipient  state  of  change,  as  it  is  well  known  that  lemons  are 
very  prone  to  decay  at  this  season,  and  microscopic  organisms 
being  in  a  more  vitally  active  condition  than  during  the  winter, 
are  probably  capable  of  sustaining  a  high  temperature  for  a 
short  period  ;  and  thus,  although  the  heat  applied  might  retard, 
it  does  not  totally  destroy  the  tendency  to  decomposition. 
If  a  little  care  is  exercised,  stoppers  or  perforated  corks  are 
unnecessary,  common  corks  answer  quite  well ;  and  for  cover- 
ing the  tops  of  these  (when  cut  off),  I  think  bees'-wax  will  be 
found  superior  to  sealing-wax,  as  it  adheres  firmly  and  is  not  so 
liable  to  crack. 
I  would  then  suggest,  that  if  a  ten  or  twelve  months'  stock 
of  lemon-juice  is  thus  bottled  at  a  temperature  not  necessarily 
above  150°  during  the  winter,  the  dispenser  would  be  enabled 
without  delay  to  send  it  out  in  a  state  even  superior  to  that 
freshly  obtained  from  the  fruits ;  and  this  being  generally 
adopted  would  give  satisfaction  both  to  prescriber  and  patient. 
— Pharm.  Jour.,  London,  Oct.,  1863. 
THE  COMPASS  PLANT. 
By  T.  Hill. 
Riding  near  Chicago,  August  8,  1863,  I  saw,  for  the  first 
time,  Silphium  laoiniatum  growing  wild.    The  field  had  once 
