ON  CHLOROFORM. 
301 
It  appears  from  these  experiments  as  if  the  presence  of  moist- 
ure, however  slight,  predisposes  chloroform  of  sp.  gr.  1*480  to 
1*484  to  a  rapid  decomposition ;  and  if  this  is  really  the  case, 
we  can  readily  understand  that  chloroform  of  a  higher  specific 
gravity,  if  filled  in  damp  bottles,  will  very  rapidly  change  under 
the  influence  of  light.  This  moisture  condenses  above  the  chloro- 
form, and,  absorbing  the  chlorinated  products  of  decomposition 
(free  chlorine  ?),  separates  in  the  form  of  yellow  drops. 
The  same  chloroform,  reduced  to  the  specific  gravity  1*459  to 
1*476,  kept  unaltered  in  the  presence  of  moisture  after  a  week's 
exposure  to  the  sunlight. 
It  is  due  to  my  friend,  Mr.  Augustus  Henkel,  now  of  Cincin- 
nati, to  state  that  quite  a  number  of  the  experiments  referred  to 
above  were  either  made  or  verified  by  him  during  the  summer  of 
1865. 
The  observations  and  experiments  with  chloroform  have  been 
quite  numerous  since  my  attention,  about  three  years  ago,  had 
been  directed  more  particularly  to  its  ready  spontaneous  decompo- 
sition, to  which,  contrary  to  the  direct  and  indirect  statements  of 
Stadeler,  Hager  and  others,  chloroform  prepared  from  good  alco- 
hol is  subject  if  its  density  exceeds  a  certain  point.  These  state- 
ments do  not  attempt  to  prove  that  chloroform  prepared  from 
other  material  is  alone  subject  to  decomposition,  but  merely  assert 
that,  made  from  alcohol,  it  was  found  to  keep  well,  which  fact 
may  be  readily  explained  by  low  specific  gravity  and  absolute 
dryness.  My  own  observations  prove  that  this  tendency  to 
change  increases  with  the  specific  gravity,  or,  in  other  words, 
with  the  absolute  chemical  purity  of  chloroform,  and  the  total 
absence  or  the  presence  of  minute  quantities  of  those  compounds 
imparting  a  brown  color  to  sulphuric  acid,  do  not  appear  to  make 
any  difference  whatever.  The  few  observations  made  on  this 
point  seem  to  indicate  that  moisture  will  hasten  the  decomposition 
in  the  light. 
The  practical  results  derived  from  the  foregoing  are  as  fol- 
lows : — 
1.  Chloroform  of  sp.  gr.  1*475  and  less  will  keep  in  dry  or 
damp  bottles,  in  diffused  daylight  and  direct  sunlight. 
2.  Chloroform  of  sp.  gr.  1*480 — 1*484  will  remain  unaltered 
