THEBOLACTIC  ACID. 
467 
liquid  is  digested  with  levigated  litharge  at  a  heat  of  about 
140°  Fahr.,  with  frequent  stirring. 
The  thinned  and  filtered  liquid,  having  been  then  concen- 
trated to  a  thick  consistency,  is  mixed  up  with  a  large  quantity 
of  S.  V.  R.  From  the  filtered  spirituous  liquid  the  bases  are 
carefully  thrown  down  as  sulphates  by  the  addition  of  sulphuric 
acid  (of  which,  to  do  this,  a  large  quantity  is  necessary).  The 
filtered  liquid,  after  careful  neutralization  with  milk  of  lime,  is 
distilled  to  recover  the  spirit. 
On  the  contents  of  the  still  being  then  brought  to  a  syrupy 
consistence,  and  laid  aside  for  a  week  or  so,  the  syrupy  liquid 
sets  into  a  crystalline  mass  of  thebolactate  of  lime. 
Having  obtained  the  lime  salt,  it  is  easily  purified  by  repeated 
crystallization  and  the  use  of  charcoal.  After  bringing  the  salt 
to  a  snowy  whiteness,  the  acid  can  then,  by  the  addition  of  the 
equivalent  quantity  of  sulphuric  acid  and  the  use  of  S.  V.  R., 
or  other  obvious  means,  be  obtained  in  a  separate  state. 
From  the  unvarying  occurrence  of  this  acid  in  opium,  and  its 
abundance,  there  cannot  be  any  more  doubt  of  its  pre-existence 
there  than  of  meconic  acid,  codeia,  thebia,  or  morphia  itself. 
Since  its  discovery,  the  general  yield  from  Turkey  opium  of  the 
thebolactate  of  lime  has  been  about  two  per  cent. 
The  circumstance  of  the  quantity  of  meconic  acid  obtained 
from  opium  being  decidedly  less  than  corresponds  to  the  mor- 
phia and  other  organic  bases,  is  a  strong  argument  in  itself  for 
the  pre-existence  of  thebolactic  acid,  and  from  this  conviction 
arose  the  search  for,  and  discovery  of,  this  new  acid  in  opium. 
Though  we  have  some  reason  to  think  Mr.  Watts  rather  loose, 
our  object  here  is  not  to  complain,  but  to  draw  attention  to  an 
interesting  matter. 
Our  belief  that  thebolactic  acid  exists  as  a  constituent  ingre- 
dient of  opium  is  founded  on  the  fact  that  it  was  separated  from 
at  least  twenty  different  consignments  of  opium  of  different  sea- 
sons, and  that  the  yield  was  uniform,  and,  as  nearly  as  could  be 
judged,  invariable  in  quantity.  Altogether,  we  prepared  about 
one  hundredweight  of  thebolactate  of  lime,  most  of  which  we 
purified  to  a  snowy  whiteness. 
Dr.  Anderson,  in  his  present  letter  to  us,  says — "I  think  fur- 
