'^°'jun"e?im'°'*}      Vapor  Dendty  of  Ferric  Chloride.  297 
for  ferrous  salt.  Experiments  at  a  lower  temperature  were  out  of  the 
question,  as  even  in  these  the  vaporization  w^as  rather  slow. 
At  518°  (in  vapor  of  phosphorus  pentasulphide),  three  experi- 
ments gave  a  vapor-density  of  9*569 ;  about  to  of  the  iron  was  found 
to  be  in  the  ferrous  condition  after  the  estimation. 
At  606°  (in  vapor  of  zinc  chloride),  in  a  smaller  apparatus,  six  ex- 
periments gave  a  mean  vapor-density  of  8*383 ;  about  J  of  the  iron 
was  in  the  ferrous  state  at  the  close. 
The  determinations  at  higher  temperatures  were  effected  in  platinum 
apparatus  heated  in  a  Perrot's  gas  furnace.  The  mean  of  three  esti- 
mations at  about  750°  gave  a  vapor-density  of  5*406,  whilst  about  ^ 
of  the  iron  was  found  to  be  in  the  ferrous  state  at  the  close  of  the  ex- 
periments. At  about  1050°,  the  numbers  obtained  for  the  density 
were  5*3  and  4*9  ;  i  and  i  of  the  iron  being  respectively  found  in  the 
ferrous  state.  The  results  at  1300°  were  practically  identical  with 
those  at  1050°.  As  it  seemed  probable  that  the  lower  results  in  the 
higher  temperature  experiments  might  be  due  to  the  action  of  the  pla- 
tinum on  the  ferric  chloride,  experiments  were  made  in  platinum  appa- 
ratus at  about  600°,  but  the  results  obtained  were  in  agreement  with 
those  previously  got  in  glass. 
With  regard  to  the  amounts  of  ferrous  salt  observed  at  the  end  of 
the  experiments,  it  must  be  remembered  that  this  does  not  show  the 
amount  of  dissociation  that  occurred  at  the  temperature  of  the  experi- 
ment, inasmuch  as  recombination  occurs  on  cooling. 
Experiments  in  a  chlorine  atmosphere  at  the  temperature  of  boiling 
sulphur  and  boiling  phosphorus  pentasulphide  respectively,  gave 
practically  the  same  results  as  those  in  an  atmosphere  of  nitrogeu. 
From  these  results  it  follow^s  that  ferric  chloride  does  not  at  any  tem- 
perature show  a  vapor-density  sufficiently  high  for  the  molecular  for- 
mula EeaClg,  whilst  at  750°  and  1077°  numbers  were  obtained  not 
far  removed  from  5*6,  the  calculated  vapor-density  for  the  molecular 
formula  FeClg. 
€rucle  Sulpbo  Carbolic  Acid  as  a  Disinfectant.— Laplace, 
{Deutsche  medizinische  Wochenschrift,  No.  7,  1888,)  mixes  sulphuric  with  an  equal 
weight  of  crude  carbolic  acid  (twenty-five  per  cent,  in  strength)  which  yields  a 
blackish,  syrupy  liquid  soluble  in  water.  A  four  per  cent,  watery  solution  of  this 
compound  destroyed  the  virulence  of  anthrax  in  forty-eight  hours.  Creolin,  is  im- 
potent in  solutions  of  two  per  cent.,  to  destroy  anthrax  ;  the  acidified  solutions 
of  corrosive  sublimimate  (1  to  1000)  are  potent  against  anthrax,  but  are  not  so 
available  in  practice. 
