ON  CHLOROFORM. 
41 
ON  CHLOROFORM. 
By  W illiam  Huskisson,  Jr. 
A  process  appeared  some  time  since,  by  Dr.  Gregory,  on  the 
purification  of  chloroform  by  means  of  sulphuric  acid ;  a  short 
time  after  its  publication,  an  article  was  added  by  Professor 
Christison,  (in  the  absence  of  Br.  Gregory,}  stating  that  chloro- 
form, purified  by  sulphuric  acid,  had  speedily  undergone  decom- 
position,— had  become  loaded  with  chlorine,  and  thus  rendered 
quite  unfit  for  use, — and  that  the  manufacturer  had  failed,  in 
almost  every  instance,  in  obtaining  a  permanent  article.  Since 
that  period,  no  process  for  the  preparation  or  the  purification  of 
chloroform  has  been  published,  except  in  the  pharmacopoeia ;  it 
has  been  left  entirely  to  the  discretion  of  the  manufacturer. 
Kecently,  at  a  meeting  of  the  Pharmaceutical  Society,  Dr.  Pe- 
reira  exhibited  a  specimen  of  chloroform,  which  had  not  only 
undergone  change,  but  had  become  of  a  pink  color. 
Having  prepared  chloroform  on  a  large  scale,  and  having  had 
considerable  experience  in  the  changes  it  undergoes  when  puri- 
fied by  sulphuric  acid,  the  following  is  the  only  process  by  which 
I  have  always  obtained  a  permanent  article ;  and  one  which  I 
have  never  found,  under  any  circumstances,  undergo  change  or 
decomposition.  I  take  130  lbs.  of  chloride  of  lime  and  7  lbs.  of 
common  lime,  put  them  into  a  capacious  still,  with  sufficient 
water  to  make  a  thin  paste ;  when  well  stirred  together,  I  then 
add  more  water  with  25  lbs.  of  rectified  spirit;  (taking  care  that 
the  still  shall  not  be  more  than  half  full,}  lute  it  down  ;  load  it ; 
apply  a  gentle  heat  and  commence  distillation ;  separate  what 
comes  over  from  the  supernatant  liquor,  and  wash  it  several  times 
with  distilled  water ;  put  the  washings  and  supernatant  liquor 
again  into  the  still,  with  one-half  the  above  quantities,  and  proceed 
as  before  ;  then  introduce  the  chloroform  thus  obtained  into  an 
ordinary  still,  with  four  or  five  times  its  weight  of  distilled  water, 
with  a  small  quantity  of  lime ;  apply  heat,  and  let  the  chloroform 
bubble  through  the  water,  and  pass  over ;  separate  the  chloro- 
form from  the  water  that  comes  over  with  it,  by  means  of  a 
separatory  funnel,  and  agitate  it  with  a  little  highly  dried  car- 
bonate of  potash,  to  entirely  abstract  from  it  a  small  portion  of 
water  it  generally  contains. 
4* 
