ACTION  OF  PHOSPHATE  OF  SODA  ON  FLUOR  SPAR.  529 
ON  CHLOROFORM. 
Bremon  gives  the  following  reactions  by  which  the  impurities 
of  chloroform  are  determined.    It  boils  at  45Q  C. ;  at  all  tem- 
peratures it  is  very  volatile  ;  it  does  not  produce  so  strong  a  sen- 
sation of  cold  as  ether  in  its  evaporation  from  the  hand. 
Entirely  free  from  alcohol  and  water,  it  should  have,  at  least,  a 
specific  gravity  1.494  at  15°  C.    Potassium  does  not  decompose 
it,  the  surface  of  the  metal  being  only  covered  with  small  gas 
bubbles,  but  when  alcohol  is  present,  the  entire  mixture  becomes 
quite  colored,  attended  with  the  liberation  of  sharp  acid  fumes. 
On  the  addition  of  1  to  5  per  cent,  of  90  per  cent,  alcohol,  it 
becomes  cloudy,  and  it  only  regains  its  transparency  when  10 
per  cent,  is  added.    Pure  chloroform  on  being  shaken  with  a 
small  portion  of  bi-chromate  of  potash,  sulphuric  acid  and  water, 
and  allowed  to  remain  quietly  for  a  time,  assumes  a  light  green- 
ish yellow  color ;  the  presence  of  5  per  cent,  of  alcohol  is  im- 
mediately detected,  the  mixture  separating  in  two  sharply  divided 
layers,  the  lowest  of  which  being  of  a  green  color.    The  same 
occurs  when  ether  is  present.    By  the  addition  of  water,  the 
specific  gravity  of  chloroform  can  be  reduced  to  1.40;  potassium 
in  such  chloroform  is  rapidly  oxidized. 
Alcohol,  the  most  common  adulterating  menstruum,  lowers  the 
specific  gravity  in  the  following  proportions  : 
Vol.  of  Alcohol.       S.  G.  Vol.  of  Alcohol.       S.  G. 
0  1.4945  5  1.4772 
1  1.4908  10  1.4602 
2  1.4874  20  1.4272 
3  1.4845  25  1.4090 
S.  S.  Garrigues. 
ON  THE  ACTION  OF  PHOSPHATE  OF  SODA  ON  FLUOR  SPAR, 
By  H.  Briegleb. 
Combinations  of  fluorine  will  certainly  become  of  technical 
importance ;  their  mode  of  preparation  is  at  present  so  very  dif- 
ficult, and  they  can  be  made  only  in  such  small  quantities  at  a 
time,  that  the  author  was  induced  to  experiment  on  the  changes 
which  take  place  at  an  elevated  temperature,  between  phosphate 
of  soda  and  fluoride  of  calcium,  hoping  to  arrive  thus  at  a  prac- 
tical method  for  obtaining  fluoride  of  sodium. 
34 
