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MEDICAL  CONSTITUENTS  OE  THE  LEMON. 
MEDICINAL  CONSTITUENTS  OF  THE  LEMON. 
Dr.  Cogswell  read  before  the  Physiological  Society,  (March  13, 
1854),  a  paper  on  this  subject.  The  author's  attention  had  been 
drawn  to  the  subject  by  the  publications  of  Dr.  Owen  Rees,  and 
others,  on  the  treatment  of  rheumatism  by  lemon-juice.  The  remedy 
was  no  doubt  often  successful,  but  still  there  wTere  many  failures, 
and  these  did  not  seem  to  be  sufficiently  accounted"  for,  as  had 
been  attempted,  by  reference  to  the  different  forms  of  the 
disease.  But  there  was  much  uncertainty  as  to  what  con- 
stitutes lemonjuice.  Has  it  always  the  same  composition,  or 
are  there  not  various  accidental  circumstances  attending  its 
preparation,  calculated  to  render  one  specimen  different  from 
another.  Sometimes  the  fruit  is  ordered  to  be  squeezed  at  home  ; 
at  other  times,  the  prescription  is  sent  to  a  druggist,  or  the  juice 
is  allowed  to  be  purchased  where  it  is  cheapest.  When  obtained 
from  the  fresh  fruit,  by  depression,  without  removing  the  rind,  it 
is  a  turbid,  pale  yellow  fluid,  exhaling  a  grateful  odor  of  the  es- 
sential oil,  and  of  a  specific  gravity  in  different  specimens  between 
1043  and  1047.  By  distilling  a  fresh  specimen  which  had  not 
been  filtered,  the  author  had  obtained  half  a  drachm  of  essential 
oil  from  12  ounces  ;  but  from  another,  after  filtering,  only  five 
minims.  Some,  purchased  at  a  fruit-preserver's,  which  had  stood 
for  several  months  in  a  cask,  and  undergone  a  kind  of  fermenta- 
tion, was  bright  yellow  and  clear,  of  density  1037,  and  yielded 
scarcely  a  trace  of  oil.  It  had  received  an  impregnation  of  com- 
mon salt  from  the  former  contents  of  the  cask.  A  sample  of  lime- 
juice,  procured  from  the  stores  of  a  merchant-vessel,  smelt  of  rum, 
had  a  density  of  1010,  and  contained  a  multitude  of  torulse.  The 
effect  of  the  different  processes  for  preserving  the  juice,  mentioned 
by  Christison,  was  to  separate  one  or  more  of  the  ingredients 
which  might  be  of  consequence  to  its  remedial  efficacy.  Heat 
would  expel  the  essential  oil,  filtration  remove  the  solid  debris  of 
the  pulp,  and  the  addition  of  alcohol  with  filtration  withdraw  the 
mucilaginous  matter.  It  appeared  that  the  druggists  in  London 
do  not  make  a  practice  of  keeping  the  juice  ready  on  demand,  but 
that  they  generally  prepare  it  extemporaneously  wThen  ordered. 
The  dose  was  equally  a  matter  of  uncertainty;  for  although  it  seemed 
o  be  the  prevalent  idea  that  the  average  produce  of  a  lemon  was 
