MEDICAL  CONSTITUENTS  OE  THE  LEMON. 
553 
about  half  an  ounce,  the  author  had  not  found  any  ordinary  speci- 
men yield  less  than  seven  drachms,  while  the  average  was  rather 
more  than  an  ounce.  Hence,  he  concluded  that  it  was  necessary 
to  fix  a  standard  for  the  composition  and  dose  of  the  juice,  before 
its  remedial  efficacy  could  be  fairly  tested.  In  the  rind,  besides 
the  essential  oil,  the  author  observed  granules  of  starch.  A  decoc- 
tion of  the  white  spongy  portion  afforded  pectine,  hesperidine,  and 
a  trace  of  tannin.  Hesperidine  was  discovered  by  M.  Lebreton, 
who  employed  orangettes  ;  but  his  process  was  complicated  and 
unproductive.  The  author  had  found  it  was  deposited  in  crystals 
by  evaporating  a  decoction  of  the  white  portion  of  the  rind,  while 
in  the  same  portion  of  the  shaddock,  it  was  separated  by  simple 
maceration  in  cold  water,  and  could  be  collected  in  a  filter.  A 
specimen  as  thus  obtained,  was  exhibited  to  the  Society.  It  had 
a  decidedly  bitter  taste,  bat  turned,  not  red,  as  commonly  stated, 
but  yellow  with  sulphuric  acid. 
Another  principle,  called  aurardiin,  was  supposed  to  be  the 
source  of  the  bitterness  of  the  lemon  tribe  ;  but  its  existence  had 
not  been  demonstrated,  and  the  author  was  disposed  to  regard  the 
hesperidine  as  the  true  bitter  principle.  The  essential  oil  belonged 
to  a  class  corresponding  to  the  formula  C5H4,  and  including  the 
other  oils  of  the  fruits  of  the  lemon  tribe,  the  oils  of  turpentine, 
juniper,  savine,  elemi,  copaiba,  cubebs,  and  pepper.  Some  of 
these  were  approved  remedies  in  rheumatism.  From  trials  made 
with  the  oil  of  lemon  in  this  disease,  in  flatulent  dyspepsia,  and 
leucorrhcea,  the  author  entertained  a  high  opinion  of  its  therapeu- 
tical value,  and  thought  that  the  chemical  fact  stated,  suggested 
the  possibility  of  bringing  together  the  various  scattered  evidences 
on  the  medicinal  effects  of  the  oils  of  the  same  class,  and  referring 
them  to  a  general  law.  The  fresh  juice,  when  evaporated  in  a 
water  bath,  yielded  about  8.5  grains  per  cent,  of  solid  extract,  and 
the  ash  obtained  by  incineration  amounted  to  0.27  per  cent.  The 
latter  contained  sulphuric  and  phosphoric  acids,  potash,  lime,  mag- 
nesia and  iron.  A  controversy  existed  as  to  whether  the  citric 
acid  or  the  potash,  in  lemon-juice,  was  the  true  medicinal  consti- 
tuent. In  reviewing  the  evidence,  the  author  conceived  that  it  was 
an  error  to  suppose  that  either  of  them  would  answer  so  well  se- 
parately. The  efficiency  of  the  juice  probably  depended,  not  on 
one  or  the  other  of  the  ingredients,  but  on  the  whole  combined.  In 
