456 
MANUFACTURE  OF  SULPHATE  OF  QUININE. 
which  it  is  digested  at  about  a  temperature  of  160°  for  one  hour 
or  more  in  a  mixture  of  hydrochloric  acid  and  water,  formed  by 
adding  two  fluid  pints  of  acid  to  50  gallons  of  water  ;  in  this  acid 
mixture  the  bark  is  kept  well  agitated.  After  boiling  for  a 
quarter  of  an  hour,  the  acid  liquor  is  run  off,  and  the  bark  strained. 
This  digesting  and  boiling  of  the  bark  in  acidulated  water  is 
repeated  a  second  and  a  third  time.  The  weak  acid  solutions 
from  the  second  and  third  boilings  are  kept  for  the  purpose  of 
exhausting  fresh  portions  of  bark.  The  strong  acid  solutions  are 
heated  very  gently  with  excess  of  cream  of  lime,  by  which  the 
quinine,  quinidine  and  cinchonine  are  thrown  out  of  solution,  and 
the  liquor  is  allowed  to  cool. 
To  this  mixture  is  then  added  fusel  oil,  turpentine,  camphine, 
or  other  hydrocarbon  insoluble  in  water  and  lighter  than  it;  the 
patentees  giving  the  preference  to  fusel  oil,  which  is  used  in  the 
proportion  of  one  pint  for  each  gallon  of  acid  solution,  and  the 
solution  of  the  alkaloids  is  assisted  by  well  agitating  the  mixture. 
By  this  process  the  alkaloids  (or  some  of  them  only,  according 
to  the  solvent  employed)  are  dissolved ;  and  on  repose,  the  solu- 
tion will  be  found  swimming  on  the  top  of  the  heavier  watery 
fluid  containing  the  chloride  of  calcium.  The  lighter  fluid  is  then 
drawn  off  by  means  of  a  syphon,  and  repeatedly  and  thoroughly 
well  agitated  with  a  solution  of  six  fluid  ounces  of  sulphuric  acid 
in  fourteen  gallons  of  water.  By  this  process  the  alkaloids  are 
transferred  from  the  original  solvent  to  the  diluted  sulphuric 
acid,  and  the  quinine  and  other  alkaloids  become  dissolved  in  the 
acid  solution.  The  two  fluids  separate  on  repose  in  consequence 
of  the  great  difference  in  the  specific  gravities,  and  should  be 
separately  syphoned  off.  The  solvent  having  rendered  up  the 
alkaloids  to  the  acid  may  again  be  used  as  a  solvent  for  fresh 
portions  of  the  alkaloids.  The  acid  liquor  containing  the  alka- 
loids in  solution  is  now  a  concentrated  mixed  solution  of  sulphates 
of  quinidine,  quinine  and  cinchonine,  with  slight  excess  of  sul- 
phuric acid  and  some  coloring  matter.  The  solution  is  next 
decolorized  by  boiling  with  animal  or  vegetable  charcoal,  taking 
the  necessary  precautions  to  prevent  any  loss. 
The  solution  is  then  divided  into  two  equal  parts,  to  one  of 
which  is  added  a  solution  of  caustic  soda  or  ammonia,  or  a  solu- 
tion of  the  carbonates  of  soda  or  ammonia,  in  quantity  sufficient 
