574  Practical  Notes. 
(        -i\OV.,  iool. 
PRACTICAL  NOTES  FROM  FOREIGN  JOURNALS. 
By  the  Editor. 
Chlorine  Water. — Berthelot  determined  the  solubility  of  chlorine  to 
be  at  12°C.  4  grams  of  the  gas  in  1  liter  of  water;  by  long  continued 
action  6  grams  of  chlorine  may  be  dissolved  in  consequence  of  the 
gradual  formation  of  oxy-acids  of  chlorine. 
Concentrated  solutions  of  metallic  chlorides  dissolve  much  less  chlo- 
rine than  pure  water,  but  the  solubility  increases  with  dilution. 
Strong  hydrochloric  acid  dissolves  a  much  larger  amount  of  chlo- 
rine to  an  orange  colored  liquid,  with  the  formation  of  a  hydrogen 
perchloride,  probably  of  the  formula  HCL. — Ami.  Chim.  Phys. 
Sodium  bicarbonate,  containing  ammonium  bicarbonate,  is  occasion- 
ally met  with,  if  prepared  from  soda  obtained  by  the  ammonia  pro- 
cess. Should  it  contain  more  than  traces  of  the  ammonium  salt,  a  layer 
of  it,  2  or  3  centimeters  (1  inch)  broad,  and  0'5  cm.  inch)  thick 
will  cause  white  vapors  to  appear,  if  a  glass  rod  moistened  with  con- 
centrated acetic  acid,  or  with  12'5  per  cent,  hydrochloric  acid,  be  held 
near  the  surface  of  the  powder.  For  the  detection  of  traces  of  the 
ammonium  salt,  about  2  grams  of  the  powder  is  heated  in  a  rather  long 
test  tube;  the  vapor  evolved  is  tested  with  a  glass  rod  as  above. — 
Ph.  Centralhalle,  1881,  p.  342. 
Foivler\s  Solution. — Dannenberg  does  not  regard  the  algaceous 
growth,  occasionally  observed  in  this  liquid,  as  being  of  any  import-' 
ance  concerning  the  arsenic  present ;  but  he  directs  attention  to  the 
gradual  oxidation,  in  partly  filled  bottles,  of  the  arsenious  to  arsenic 
acid,  as  was  shown  by  Fresenius  many  years  ago.  According  to 
Frerichs  and  Woehler  arsenic  acid  is  far  less  poisonous  than  arsenious 
acid,  and  it  is  obvious  that  it  cannot  be  immaterial  which  of  the  two 
compounds  is  present.  Fowler's  solution  should  be  prepared  only  in 
small  quantities  and  preserved  in  well  stopped  vials. — Phar.  Cen^ra^- 
Aa/^e,  1881,  p.  319. 
Preparation  of  Sodium  Ethylate.  —  Hager  gives  the  following 
directions :  100  grams  absolute  alcohol  are  placed  into  a  glass  flask  of 
350  ccm.  (about  12  oz.)  capacity;  small  pieces  of  the  metallic  sodium  of 
the  size  of  a  pea  or  bean  are  then  gradually  added,  and  the  flask  is 
closed  with  a  cork,  through  which  a  long  open  glass  tube  passes  for 
the  purpose  of  condensing  the  alcoholic  vapors  evolved  during  tla^  reac- 
tion. The  addition  of  sodium  is  continued,  until  12  grams  of  the  metal 
have  been  used,  repeated  agitation  being  required  towards  the  end  of 
