COMPOUND  SYKUPS  OF  PHOSPHATES. 
19 
up  and  turn  on  more  spirit,  to  ensure  a  complete  saturation.  Let 
it  stand  four  or  five  days  covered.  Then  transfer  to  proper 
percolators,  and  pack  it  so  closely  that  percolation  shall  take 
place  slowly.  Continue  the  process,  adding  fresh  portions  of 
spirit  until  the  strength  is  extracted.  As  the  tincture  is  ob- 
tained, it  should  be  divided  into  different  portions ;  that  is,  the 
stronger  and  the  weaker  tincture  are  to  be  kept  separate. 
The  vacuum  pan  is  now  charged  with  twenty  gallons  of  the 
first  or  saturated  tincture,  and  fifty  pints  of  alcohol  carefully  dis- 
tilled off  through  the  rectifying  column,  at  a  heat  of  100°.  This 
will  be  of  88  per  cent.,  or  spec.  grav.  .827.  Set  this  aside  for 
future  use.  Now  withdraw  from  the  still  its  contents,  and  hav- 
ing placed  in  it  twenty  pounds  of  sugar,  charge  it  with  the  last 
or  weakest  tincture  and  proceed  with  the  evaporation,  adding 
the  successive  portions  of  tincture,  until  the  whole  is  reduced  to 
sixty-five  pints,  which  is  shown  by  a  graduated  scale  on  the 
vacuum  pan.  At  the  commencement  of  evaporation,  the  ther- 
mometer will  mark  110°  of  heat,  but  it  gradually  rises  as  the 
extract  acquires  consistence,  and  at  the  close  will  stand  at  120° 
to  125°.  Add  to  the  contents  of  the  still  thirty-five  pints  of  the 
alcohol  first  distilled  and  agitate  the  liquid  until  the  precipitates 
are  dissolved.  Draw  out  the  perfected  extract  into  a  close 
vessel.  When  cold,  stir  it  well,  let  it  stand  a  few  days,  decant  and 
bottle. 
In  send  you  a  sample  of  fluid  extract  of  ergot  and  fluid  ex- 
tract of  cinchona  made  by  this  process.  They  have  each  been 
bottled  about  five  months.  My  impression  concerning  age  in 
fluid  extracts  prepared  by  this  process,  is,  that  when  properly 
corked,  they  improve  by  age,  like  old  wine,  "  mellowing"  without 
injury  to  their  medicinal  effects. 
Cambridgeport,  Mass.,  Dec.  7th,  1857. 
ON  A  NEW  METHOD  OF  PREPARING  THE  COMPOUND  SYRUP 
OF  PHOSPHATES. 
By  Joseph  Gr.  Richardson. 
Being  induced,  at  the  request  of  a  neighboring  physician,  to 
attempt  the  preparation  of  a  syrup  of  the  phosphates  of  iron, 
lime,  soda  and  potassa,  I  was  led  to  a  series  of  experiments,  re- 
