ARSENIFEROUS  SULPHUR,  ETC. 
443 
3As03-f3HO,  and  the  corresponding  soda  salts,  were  obtained 
in  a  similar  manner.  The  silver  salt  was  tribasic,  amorphous 
when  first  precipitated,  afterwards  becoming  crystalline.  There 
were  three  lead  salts,  a  monobasic  and  bibasic  salt,  and  a  third 
which  was  obtained  from  an  acid  solution  and  had  the  composi- 
tion, 3PbO,3HO,2As03.  The  zinc  salt  was  tribasic,  even  when 
deposited  from  an  acid  solution,  and  under  the  microscope  was 
seen  to  consist  of  a  number  of  spheres.  The  magnesia  salt, 
2MgO,HO,As03-fAq.  the  copper  salt,  2CuO,HO,  As03,  and  the 
baryta  salt,  BaO,2HO,  As03,  had  also  been  prepared — Chem. 
News,  London,  June  7,  1862. 
ON  THE  ARSENIFEROUS  SULPHUR  FROM  THE  SOLFATARA  OF 
NAPLES,  AND  PREPARATION  OF  SELENIUM. 
By  Dr.  T,  L.  Phipson,  F.C.S. 
This  sulphur  is  of  an  orange  color,  only  partially  soluble  in 
sulphide  of  carbon,  differing  in  this  respect  from  the  crystallised 
sulphur  of  Sicily,  which  I  find  to  be  totally  soluble  in  sulphide 
of  carbon.  It  contains  both  selenium  and  arsenic ;  the  latter 
in  considerable  quantity.  The  following  is  the  analysis  of  an 
average  sample : — 
Sulphur  ....  87-600 
Arsenic  ....  11-162 
Selenium     ....  0-264 
99-026 
Or, 
Sulphur  ....  80458 
Sulphide  of  arsenic,  AsS3  .  18-304 
Selenium      ....  0-264 
99-026 
When  heated  in  a  platinum  capsule  it  almost  entirely  dis- 
appears, leaving  only  a  slight  trace  of  a  black  substance,  in- 
soluble in  nitric  acid,  and  giving  the  reaction  of  silica  before  the 
blow-pipe. 
Of  the  87-600  of  total  sulphur  contained  in  this  substance, 
64.26  dissolve  readily  in  aqua  regia,  but  the  remaining  23-34 
