ON  CHLOROFORM. 
43 
tated  with  the  purest  sulphuric  acid,}  has  caused  decomposition 
of  the  chloroform  as  well  as  of  the  oil.  It  occurred  to  me,  that 
the  sulphuric  acid  converted  the  chloroform  into  formic  acid  by 
affording  it  sufficient  oxygen,  and  the  free  chlorine  combined 
with  hydrogen,  thus  forming  hydrochloric  gas.  When  chloro- 
form has  been  treated  with  sulphuric  acid,  it  is  usually  agitated 
with  oxide  of  manganese,  which  decomposes  any  free  sulphurous 
acid  that  might  be  present. 
i  Another  remarkable  phenomenon  in  decomposed  chloroform,  is 
the  formation  of  a  number  of  crystals  round  the  upper  surface  of 
the  chloroform,  and  after  the  lapse  of  a  few  weeks,  its  becoming 
a  delicate  pink  color,  which  is  sometimes  fugitive,  owing,  no 
doubt,  to  a  salt  of  manganese,  most  probably  a  sulphate  ;  and 
this  opinion  is  strengthened  by  the  fact  of  its  being  observable 
in  the  following  preparations  : 
When  acetic  acid  is  obtained  by  decomposing  acetate  of  soda 
by  sulphuric  acid,  the  sulphurous  acid  that  is  formed  passes  over 
with  the  acetic  acid ;  to  remove  this  mineral  acid,  it  was  usual  to 
add  oxide  of  manganese  ;  after  a  short  time,  the  acetic  acid  that 
has  been  thus  deprived  of  its  sulphurous  acid  will  frequently 
become  pink,  and  deposit  pink  crystals ;  also  in  the  preparation 
of  chlorate  of  potash,  if  the  heat  applied  to  the  mixture  be  too 
great,  and  the  mixture  boils  over,  the  mother  liquors  will  fre- 
quently be  of  a  rich  pink  color.  From  these  results  I  think  we 
may  safely  infer,  that  it  is  a  salt  of  manganese,  like  the  mineral 
chameleon,  which  gives  rise  to  the  formation  of  crystals  in,  and 
to  the  changing  color  of  chloroform,  when  subjected  to  Dr. 
Gregory's  process. 
I  have  tested  and  examined  large  quantities  of  Edinburgh  and 
Dublin  chloroform,  but  have  never  met  with  any  to  supersede, 
or  even  equal  in  its  general  characters,  that  prepared  from  the 
spirit  obtained  from  the  best  London  distillers ;  I  regret  that 
many  scientific  journals  should  have  stated  that  the  Edinburgh 
manufacturers  have  devoted  more  care  and  attention  to  its  pre- 
paration, and  have  produced  the  best  chloroform.  The  fact  is, 
while  the  London  manufacturers  were  using  every  effort  to  cover 
the  actual  expenses  of  materials,  &c,  to  say  nothing  of  profit, 
owing  to  the  great  difference  in  the  duty  on  spirit  or  whiskey  in 
England,  and  Scotland,  and  Ireland,  {chloroform  is  admitted  free 
