26 
PREPARATION  OP  CHLOROPORM,  ETC. 
The  advantage  derived  from  this  arrangement  is  the  saving  of 
the  labor  and  expense  of  elevating  the  chloride  of  lime  to  the 
second  storj,  which  would  be  necessary  were  the  still  above 
ground. 
The  ^ t ill  is  constructed  of  boiler  iron,  is  about  six  feet  in  di- 
ameter, and  eight  feet  high,  surmounted  by  a  dome-shaped  top 
of  cast  iron,  the  apex  of  which  is  extended  vertically  by  a  coni- 
cal leaden  neck  to  the  height  of  five  feet,  when  it  bends  and 
connects  with  the  condensing  worm.  This  consists  of  150  feet 
of  inch  and  a  quarter  lead  tube  coiled  in  a  large  cask  six  feet 
in  diameter,  the  water  in  which  is  constantly  renewed  by  a 
hydrant.  There  are  several  lateral  faucets  to  the  still  at  various 
heights  to  ascertain  the  elevation  of  the  contents  during  the  re- 
action. The  dome  is  penetrated  by  a  manhole  through  which 
the  charge  is  introduced,  and  which  is  closed  afterwards  by  a 
clamp  and  screw  pressing  on  a  cast  iron  plate  with  gum-elastic 
cloth  beneath.  A  shower  jet  is  placed  within  the  base  of  the  neck, 
connected  with  the  hydrant,  by  means  of  which  an  excessive 
reaction  may  be  moderated,  though  it  is  rarely  needed.  The 
"charge"  of  chlorinated  lime  is  500  pounds.  At  the  side  nearly 
over  the  still  a  platform  scale  is  placed,  on  which  a  large  wooden 
tube  is  supported.  Into  this  the  chloride  of  lime  is  put  and 
mixed  by  a  stirrer  with  sufficient  water  to  give  it  fluidity  and  to 
break  up  the  lumps,  when  it  is  run  into  the  still,  by  removing 
a  plug  in  the  bottom  of  the  tub  directly  over  the  manhole  of  the 
still.  Seven  and  a  half  gallons  of  95  per  cent,  alcohol  are  then 
introduced,  and  immediately  after  the  remainder  of  200  gallons 
of  water  requisite  for  the  charge.  The  opening  is  now  closed, 
and  steam  admitted  so  as  to  blow  directly  into  the  still  from  the 
pipe  which  enters  near  the  bottom,  so  that  in  its  exit  the  ingredi- 
ents shall  be  thoroughly  agitated.  As  soon  as  the  reaction  com- 
mences, which  with  good  chloride  and  steam  of  45  to  50  pounds 
pressure  is  in  about  half  an  hour,  the  steam  is  stopped  off,  and 
the  operative  gives  his  chief  attention  to  the  condensing  ar- 
rangement. The  greater  part  of  the  chloroform  comes  over  in 
the  first  ten  minutes,  but  to  get  the  last  portion,  half  an  hour 
is  requisite.  The  workman  stands  at  the  exit  tube,  out  of  which 
a  stream  of  distillate  pours  sufficient  to  fill  a  gallon  bottle  in 
less  than  a  minute  at  first,  and  changes  the  bottles  as  fast  as 
