462 
Preparation  of  Iheine. 
(  Ak.  Joue.  Pharw. 
t     Oct.  1, 1871. 
THE  PREPARATION  OF  THEINE. 
By  Chas.  Fredigke. 
In  the  Medical  Times  and  Gazette  Mr.  Lewis  Thompson  publishes 
an  article  entitled,  "  Use  of  Theine  as  a  Therapeutical  Agent,"  re- 
ported in  the  Druggists'  Circular  for  June,  page  96,  in  which  he 
described  a  convenient  method  for  the  preparation  of  this  agent ;  but 
the  writer  found  the  hollow  and  movable  axis  of  the  rotary  coffee- 
roaster  rather  awkward,  besides  its  length  of  three  feet  much  too  short 
to  insure  the  deposition  of  all  the  crystallizable  particles  of  the  vapor 
given  out  bj  two  pounds  of  coffee.  The  complete  utilization  of  that 
amount  of  vapor  would  require  a  tube  (being  one  inch  in  diameter) 
nine  to  twelve  feet  in  length,  and  even  longer.  To  obviate  these  dis- 
advantages, recourse  was  had  to  a  little  stationary  arrangement.  It 
consists  in  a  Linden's  patent  coffee-roaster,  a  thin  cast  iron  pot,  whose 
contents  may  be  turned  over  by  a  perforated  and  toothed  shovel.  To 
the  cover  a  tube  of  two  inches  in  diameter  was  fitted,  the  whole  length 
of  which  is  three  feet,  made  in  three  sections,  for  convenient  removal 
and  cleaning.  Put  on  a  stove  and  heat  the  pot  to  between  300°  and 
400°,  then  turn  in  the  coffee,  fit  on  the  cover  and  pipe,  passing  the 
free  end  of  the  latter  through  a  card  board  into  a  gallon  bottle,  then 
raise  and  continue  the  heat  for  15  or  20  minutes,  during  which  time 
the  crank  must  be  turned,  and  the  cover  now  and  then  raised  to  ex- 
amine the  color  of  the  beans,  though  this  is  not  necessary  after  two  or 
three  repetitions  of  the  process,  when  the  cover  may  be  luted  on  by  a 
cement  made  with  a  little  water  out  of  two  parts  of  linseed  meal  and 
one  part  plaster  of  Paris ;  besides,  with  a  brisk  fire  the  operation  of 
roasting  requires  but  ten  minutes,  when  the  coffee  will  have  assumed 
the  right  shade  of  color.  During  the  process  the  tube  and  the  bottle 
grow  rather  hot,  and  it  is  advantageous  to  cool  them  by  wet  rags,  but 
it  is  not  absolutely  necessary.  The  aqueous  portion  of  the  vapor  con- 
denses in  the  bottle  to  the  amount  of  two  ounces,  and  upon  removal 
of  the  cover  and  tube,  they  will  be  found  coated  with  a  thin  film, 
which  is  washed  off  by  eight  ounces  distilled  water,  with  which  the 
bottle  is  also  well  rinsed  ;  then  the  liquid  is  filtered  and  evaporated 
over  a  water  bath  to  two  ounces  ;  to  these,  two  ounces  of  dried  car- 
bonate of  potassa  is  added  (very  easily  made  by  exsiccating  2J  ounces 
of  salt  of  tartar  in  an  iron  ladle  [fitted  w^ith  a  cover],  one  of  three 
inches  diameter  by  one  inch  depth  is  large  enough,  or  a  Hessian  cru- 
cible will  answer  very  well),  the  mixture  set  aside  over  night  to  allow 
