A  NEW  ANAESTHETIC.  .  171 
ferred  to,  and  thus  renew  the  whole  process  continually,  which  of 
course  necessarily  increase  greatly  the  expense  of  working,  as 
well  as  loss  both  in  time  and  material ;  but  when  the  process  of 
purifying  referred  to  is  adopted,  it  is  found  practicable  to  work 
continuously  with  the  same  liquors  without  saturating,  (of  course 
depending  upon  the  amount  of  carefulness  in  the  manipulation), 
and  in  such  case  the  cost  of  production  is  lessened  nearly  one- 
half.  The  crystals  of  citric  acid  also  being  most  tenacious  of 
sulphate  of  lime  will  often  hold  it  so  as  to  render  them  contami- 
nated even  to  the  second  or  third  crystallization,  producing  an 
opacity,  which  when  dried  gives  them  an  appearance  of  efflores- 
cence, materially  affecting  their  commercial  value. 
This  difficulty,  which  is  also,  in  th^  opinion  of  the  writer,  to  be 
overcome,  will  form  part  of  a  future  paper. — Lond.  Chem.  News. 
Braintree,  Jan.  13,  1866. 
A  NEW  ANAESTHETIC. 
Bichloride  of  carbon,  the  new  anaesthetic,  was  first,  I  believe, 
discovered  by  M.  Regnault,  in  1839.  It  has  already  received 
various  appellations  from  various  chemists,  as  perchloroformene, 
perchlorinated  chloride  of  methyl,  bichloride  of  carbon,  carbonic 
chloride,  tetrachloride  of  carbon,  superchloride  of  carbon,  per- 
chloruretted  hydrochloric  ether,  and  perchloruretted  formene 
(see  Gmelin's  "  Handbook  of  Chemistry,"  vol.  vii,  p.  355,  and 
Watts'  "Dictionary  of  Chemistry,"  vol  L,  p.  765). 
If  it  becomes,  as  I  believe  it  will,  for  some  medicinal  purposes, 
an  article  of  the  Materia  Medica,  it  will  require  to  have  a  phar- 
maceutical name  appended  to  it,  and  perhaps  the  designation  of 
Perchloroformene,  or  the  shorter  term  Chlorocarbon,  may  prove 
sufficiently  distinctive.  In  its  chemical  constitution,  bichloride 
of  carbon,  or  chlorocarbon,  is  analogous  to  chloroform ;  with  this 
difference,  that  the  single  atom  of  hydrogen  existing  in  chloro- 
form is  replaced  in  chlorocarbon  by  an  atom  of  chlorine,  for  the 
relative  chemical  constitution  of  these  two  bodies  may  be  stated 
as  follows : — 
Chloroform     =  C2HC13 
Chlorocarbon  =  C2C1C13. 
