CRYSTALLIZATION  OF  SULPHUR. 
871 
vius,  and  Mr.  Sorby's  method  of  determining  the  temperature 
at  which  various  rocks  and  minerals  are  formed.  At  the  conclu- 
sion of  the  meeting,  crystals  containing  fluid  were  exhibited 
under  the  microscope,  and  the  expansion  of  the  fluid  by  eleva- 
ting the  temperature  of  the  crystal  whilst  under  examination. — 
Ohem.  News,  March,  1868. 
ON  CRYSTALLIZATION  OF  SULPHUR. 
An  interesting  experiment  has  been  made  by  M.  Schtitzen- 
berger  upon  the  crystallization  of  sulphur.  He  filled  a  mattrass 
of  a  capacity  of  150  or  200  grammes,  with  refined  sulphur,  com- 
mercially pure,  so  that  when  fused  the  liquid  occupied  the  whole 
of  the  space  below  the  neck ;  the  upper  part  of  the  neck  was 
drawn  out  into  a  capillary  tube  which  was  twisted  several  times, 
but  left  freely  open  to  the  atmosphere.  The  sulphur  being  melted 
in  a  bath  of  oil  heated  to  120°,  the  flask  was  placed  in  water 
heated  to  95°.  In  these  conditions  the  sulphur  remains  per- 
fectly fluid  for  hours,  even  when  occasionally  moved  and  drawn 
out  of  the  hot  water.  If  the  temperature  be  made  to  fall  very 
slowly,  transparent  crystals,  possessing  the  same  density  as  the 
melted  sulphur,  form  either  on  the  surface  or  in  the  midst  of  the 
fluid  at  about  90°.  The  mass  of  crystals  gradually  augments, 
but  with  great  slowness  ;  sometimes  they  are  isolated,  at  others 
united  in  groups  of  two,  three,  four,  &c.  The  amount  of  crystals 
being  considered  sufficient  to  separate  them,  the  mattrass  is 
slmrply  inverted,  so  as  to  cool  and  solidify  the  melted  sulphur  in 
the  neck.  Thus  the  crystals  are  separated  from  the  rest  of  the 
sulphur,  and  only  remain  suspended  by  their  peaks.  They  are 
transparent,  and  remain  so  indefinitely;  in  form  they  are  octa- 
hedral, and  bear  close  resemblance  to  natural  crystals.  Measure- 
ment of  the  angles  has  confirmed  their  identity.  The  experiment 
is  surer  when  two  or  three  drops  of  sulphide  of  carbon  are  added 
to  the  sulphur  before  fusion ;  the  phenomenon  takes  place,  how- 
ever, independently  of  this  admixture.  The  results  are  similar 
to  those  of  M.  Pasteur,  who  observed  the  formation  in  a  solution 
of  sulphur  in  a  hydrocarbon,  first  of  prismatic  crystals,  afterwards, 
when  the  temperature  was  sufficiently  low,  of  octahedra.  JBy 
