422 
ON  THE  PREPARATION  OF  CHLOROFORM. 
On  distilling  chloroform  in  larger  quantities,  particularly  on 
heating  rapidly  and  continuing  the  heat  after  the  formation  of 
chloroform  is  in  progress,  a  peculiar  odor  of  chlorine  is  fre- 
quently observed,  interfering  with  the  respiration,  and  the  pro- 
duct has  then  a  more  or  less  greenish  color  ;  its  temperature 
rises  spontaneously  to  30—45^  R.  (100  to  134^  F.,)  and  gene- 
rates gas  of  an  acrid  chlorine  odor.  If  thrown  into  water,  the 
chloroform  becomes  colorless,  and  the  wash-water  contains 
hydrochloric  acid.  In  the  direct  sunlight,  such  chloroform  loses 
its  coloration  instantly  with  more  or  less  elevation  of  tempera- 
ture. The  more  of  this  chlorine-compound  is  contained  in  the 
chloroform,  the  smaller  is  the  yield. 
If  the  mixture  has  been  heated  sufficiently,  the  chemical 
reaction  increases  the  heat  to  the  boiling  point  of  water,  all  the 
chloroform  distils  over,  and  it  is  merely  necessary  to  return  the 
supernatant  alcoholic  liquid  to  the  still,  to  obtain  the  chloroform 
contained  in  it,  by  a  moderate  heat.  Two  pounds  chlorinated 
lime  were  intimately  mixed  with  two  gallons  water  of  90^  C, 
when  the  temperature  fell  to  80*^  C. ;  after  adding  four  fluid- 
ounces  of  90  per  cent,  alcohol,  the  temperature  was  75,  but  rose 
without  any  external  heat  in  fifteen  minutes  to  87^,  in  twenty 
minutes  to  9P,  in  twenty-five  minutes  to  95°,  in  thirty-five 
minutes  to  97*^,  and  in  forty-two  minutes  to  98^^  C.,  without 
rising  any  higher.  The  mixture  boiled  with  little  foaming 
nearly  half  an  hour,  the  chloroform  vapors  being  condensed  in 
the  long  neck  of  the  flask.  In  seventy  minutes  the  temperature 
fell  to  94^,  and  in  one  hundred  and  twenty  minutes  to  60^  C. 
A  number  of  experiments  were  made  at  diff"erent  temperatures 
with  alike  quantities  of  chloride  of  lime,  alcohol  and  water. 
The  alcohol  had  a  spec.  grav.  =  .834 ;  the  chloride  of  lime 
contained  from  27  to  28  per  cent,  active  chlorine.  The  distil- 
lation was  carried  on  in  a  tubulated  copper  still  of  eight  cubic 
feet  capacity,  with  a  flat  tin  head  and  tin  condensing  pipe,  kept 
in  water  of  50^  F.  The  supernatant  stratum  of  the  distillate 
was  repeatedly  returned  into  the  still  as  long  as  chloroform  was 
separated  by  distillation.  The  chloroform  was  agitated  with 
water,  removed  by  a  separating  funnel  and  weighed. 
The  experiments  may  be  divided  into  four  distinct  groups. 
