^'oc^isw1!™-}  Two  New  Allotropic  States  of  Sulphur.  505 
the  same  time  sulphurous  acid  is  disengaged.  When  the  yellow  tint 
has  become  very  pronounced  and  before  the  liquid  has  become 
cloudy  from  the  precipitation  of  sulphur,  the  filtered  solution  is 
shaken  with  an  equal  volume  of  chloroform.  The  chloroform  is 
separated  in  a  separatory  funnel  and  left  for  spontaneous  crystalli- 
zation. There  are  thus  rapidly  obtained  some  crystals  of  sulphur, 
which  are  absolutely  different  from  octahedral  sulphur.  The  sp.  gr. 
of  these  crystals  is  2-135.  Their  crystallographic  nature  has  been 
studied  by  Friedel.1 
These  crystals  belong  to  the  rhombohedric  type  as  manifested  by 
the  deportment  with  polarized  light  and  crystalline  measurements 
and  are  absolutely  different  from  any  other  form  of  sulphur 
known. 
At  the  moment  of  their  preparation  they  are  transparent  and 
remain  so  for  3  or  4  hours.  Then  they  commence  to  increase  in 
volume  and  pass  little  by  little  into  a  state  of  insoluble  amorphous 
sulphur.  They  melt  below  ioo°.  The  coloration  of  these  crystals 
is  orange  yellow  and  not  lemon  yellow  as  are  those  of  octahedral 
sulphur  and  their  analysis  shows  that  they  are  composed  entirely  of 
sulphur. 
A  solution  of  hyposulphurous  acid  in  HC1,  prepared  as  directed 
above,  when  left  gives  a  precipitate  of  sulphur  which,  on  cooling, 
unites  into  yellow  flakes.  In  this  state,  the  sulphur  is  entirely 
soluble  in  water.  Not  only  does  it  dissolve  when  water  is  added  to 
the  liquid  which  holcfs  it  in-  suspension,  but  when  spread  rapidly 
upon  a  filter,  it  preserves  in  toto  its  solubility  in  water.  The  solu- 
tion in  water  is  rapidly  decomposed,  giving  the  ordinary  amorphous 
sulphur. 
The  explanation  of  the  formation  of  these  two  allotropic  forms  of 
sulphur  appears  to  be  the  following  :  hyposulphurous  acid  in  the 
conditions  before  mentioned  undergoes  a  progressive  decomposition 
into  sulphurous  acid  and  sulphur.  This  sulphur  is  now  in  the  atomic 
state  or  at  least  in  the  state  but  little  removed  therefrom.  .  Little  by 
little  the  sulphur,  after  separation,  is  condensed  to  the  molecular  form. 
This  condensation  takes  place  in  two  different  manners  according  as 
the  sulphur  n'as  been  dissolved  or  not,  from  the  liquor  in  which  it  is 
generated,  by  chloroform.    In  the  first  case  the  sulphur  passes  at 
1  Comptes  Rendus,  Vol.  112,  No.  16,  p.  834. 
