MANUFACTURE,  IMPURITIES  AND  TESTS  OF  CHLOROFORM.  439 
The  addition  of  eight  drops  of  alcohol  to  each  fluid  ounce  of 
decomposing  chloroform,  or  .53  per  cent,  of  its  weight,  is  the 
minimum  proportion  which  has  been  successfully  used,  though 
this  is  not  probably  the  limit  in  that  direction.  Such  an  addition, 
namely,  .53  per  cent.,  reduces  the  s.  g.  by  .0055,  or  reduces 
chloroform  of  s.  g.  1.4989  to  s.  g.  1.4934.  A  better  proportion 
of  alcohol  is,  however,  10  drops  to  each  fluid  ounce,  or  .66  per 
cent.,  reducing  the  s.  g.  by  .0069,  or  from  1.4989  to  s.  g.  1.492. 
The  writer  has  on  two  occasions,  at  least,  administered  without 
any  unusual  effect,  chloroform  that  gave  an  acid  reaction  not 
only  with  suspended  litmus  paper,  but  also  with  that  which  was 
immersed  in  the  liquid.  But  it  was  first  ascertained  by  solution 
of  nitrate  of  silver,  that  the  acid  was  not  hydrochloric. 
He  has  also  used  portions  that  were  undergoing  slow  decom- 
position, as  indicated  by  the  bleaching  effect  upon  suspended 
litmus  paper,  and  equally  without  bad  effects. 
These  circumstances  greatly  strengthen  the  position  assumed, 
that  it  is  not  chloroform,  nor  its  legitimate  elements  or  constitu- 
ents, that  produce  the  bad  effects,  but  foreign  substances  of  very 
different  nature  and  composition. 
The  specimens  before  the  Academy  are  : — 
First.  Chloroform  that  is  undergoing  the  slow  decomposition. 
S.  G.  1.4989.  This  is  the  product  of  the  described  process, 
without  the  addition  of  alcohol. 
Second.  A  portion  of  the  same  chloroform  in  which  the  de- 
composition has  been  arrested  by  the  addition  of  .66  per  cent,  of 
alcohol.  The  watery  looking  fluid  and  opalescence  produced  is 
distinctly  visible.    S.  G.  1.492. 
Third.  A  portion  of  the  second  specimen  completely  renova- 
ted by  rectification  from  powdered  quick  lime.    S.  G.  1.492. 
Fourth.  Chloroform  made  at  the  same  time,  and  by  the  same 
process  as  the  first  specimen,  but  of  a  little  lower  density,  from 
being  a  later  portion  of  the  distillate  in  the  rectification.  This 
having  undergone  no  perceptible  change.  S.  G.  1.4984. 
Fifth.  Chloroform  made  in  1853,  exhibiting  the  strongly  acid 
reaction  of  the  vapor,  while  the  liquid  is  neutral,  or  very  nearly 
so.    S.  G.  1.492. 
Sixth.  Chloroform  in  the  condition  ordinarily  dispensed  in 
the  Navy.    S.  G.  1.492. 
