SPECIFIC  GRAVITY  OF  MEDICINAL  CHLOROFORM. 
75 
was  drawn  to  the  presence  of  moisture  in  some  of  the  bottles, 
and  it  was  determined  to  try  its  effects  on  chloroform ;  accord- 
ingly, chloroform  of  1492,  dried  by  standing  oyer  chloride  of 
calcium,  was  kept  in  absolutely  dry  bottles  and  in  bottles 
slightly  moist,  and  both  *kinds  exposed  to  diffused  daylight  and 
direct  sunlight.  The  bottle  containing  the  moisture  always 
showed  the  presence  of  free  chlorine  much  sooner  than  the  dry 
one,  though  the  entire  absence  of  moisture  would  not  be  sufficient 
to  preserve  the  chloroform  unaltered.  Bat,  if  the  chloroform 
had  been  reduced  in  specific  gravity  to  1*475  or  less,  the  presence 
of  several  drops  of  water  in  the  bottle  would  not  induce  the 
liberation  of  chlorine  after  an  exposure  of  two  weeks  to  the 
direct  sunlight. 
No  difference  in  the  preservation  and  decomposition  of  chloro- 
form could  be  observed  if  the  bottles  were  stoppered  with  glass 
or  cork. 
Commercial  chloroform  was  afterwards  procured  from  several 
manufacturers,  and  in  all  cases  it  was  found  to  have  a  specific 
gravity  less  than  1-480,  or  barely  exceeding  it. 
I  have  not  found  the  time  yet  to  prepare  absolutely  pure 
chloroform  that  is  absolutely  free  from  water  and  alcohol,  to 
study  the  effect  of  light  upon  it  when  preserved  in  absolutely 
dry  bottles.  But  even  if  light  should  then  have  no  influence  on 
it,  it  would,  for  pharmaceutical  and  medicinal  purposes,  be  of  no 
avail  whatever,  since  the  condensation  of  moisture  upon  the 
bottle  in  damp  weather  could  not  be  prevented,  and  would  render 
the  chloroform  again  prone  to  change. 
The  practical  results  of  these  experiments  are  the  proof  that 
chloroform,  to  keep  it  from  getting  acid,  should  be  reduced  in 
specific  gravity  to  about  1*475.  This  is  effected  by  adding  to 
one  pound  of  chloroform  of  sp.  gr,  1*492  two  fluidrachms  of  pure 
95  per  cent,  alcohol ;  the  water  which  collects  upon  the  surface, 
on  standing,  can  be  easily  separated.  But  since,  according  to 
my  experience,  manufacturers  always  make  it  of  about  that 
specific  gravity,  the  addition  of  alcohol  to  the  chloroform,  as  met 
with  in  commerce,  is  unnecessary. 
For  medicinal  purposes,  that  is,  for  inhalation,  this  amount  of 
alcohol  would  be  unobjectionable,  since  it  amounts  in  one  fluid- 
ounce  only  to  about  forty  drops. — Proc.  Am.  Pharm.  Ass. 
