296  Finely  Divided  Metals  and  Ferric  Salts.  {^°'june?i^*'°'" 
Brown  is  also  of  opinion  that  the  whole  of  the  zinc  must  be  dis- 
solved before  titration,  but  he  does  not  state  his  grounds  for  that 
opinion. 
I  prepared  some  pulverized  zinc,  by  Hobson  and  Sylvester's  method, 
but  with  three  different  specimens  of  zinc.  I  uniformly  found  that  they 
did  not  become  brittle  at  205°  but  at  higher  temperatures,  and  also 
that  it  was  impossible  thus  to  obtain  anything  approaching  the  fine 
division  of  zinc-dust.  The  pulverized  zinc  obtained  reduced  neutral 
ferric  solutions  but  slowly. 
In  conclusion,  I  would  express  my  thanks  to  Mr.  Pattison  Muir  for 
the  kindly  suggestive  interest  he  has  taken  in  the  work  detailed. — 
Jbwr.  Chem.  Soc,  May,  1888,  468-473. 
YAPOK-DENSITY  OF  FERRIC  CHLORIDE  AT  VARIOUS 
TEMPERATURES. 
By  W.  Geunewald  and  V.  Meyer.* 
In  these  experiments,  sublimed  ferric  chloride  was  used.  The  esti- 
mations were  made  in  a  slightly  modified  form  of  V.  Meyer's  appara- 
tus, in  which  the  bulb,  45  mm.  in  diameter,  was  reduced  to  a  length 
of  only  1 25  mm.,  whilst  the  whole  apparatus  was  670  mm.  high ;  by 
this  means  the  whole  of  the  bulb  acquired  the  temperature  of  the  bath. 
For  greater  convenience  in  filling  with  nitrogen,  a  thin  tube  was  fused 
into  the  bottom  of  the  bulb,  bent  so  as  to  follow  the  shape  of  the  bulb 
and  stem  until  the  side  tubes  were  nearly  reached,  then  bent  at  right 
angles  to  connect  with  the  nitrogen  supply. 
A  new  device  of  Meyer  and  Biltz  for  the  introduction  of  the  sub- 
stance is  also  described :  On  the  stem,  opposite  to,  but  just  below  the 
delivery  tube,  a  short  side  tube  is  fused  ;  through  this  passes  a  glass 
rod  whose  end  projects  across  the  stem  ;  the  joint  between  rod  and  side 
tube  being  made  with  well- fitting  caoutchouc  tubing.  The  little  bot- 
tle containing  the  substance  rests  on  the  end  of  the  rod ;  when  the  bulb 
has  attained  the  required  temperature  the  rod  is  slightly  withdrawn, 
and  the  bottle  falls  into  the  bulb. 
Four  determinations  at  448°  (in  sulphur  vapor)  gave  a  density  of 
10-487,  whilst  that  required  by  the  formula  Fe2Cl6  is  11-2.  After  the 
estimation  the  contents  of  the  bulb  did  not  give  the  slightest  reaction 
*  Ber.  21,  687—701,  reprinted  from  "Jour.  Chem.  Soc,"  May,  1888,  p.  422. 
