'^Veb:ri75""'}     Decomposition  of  Salts  by  JVater.  67 
tion  of  fungous  growth  upon  beer  exposed  to  the  air,  and  the  spoiling  of 
milk,  wine  and  eggs.  The  observations  of  Prof.  Thiersch,  made  in 
the  surgical  wards  of  the  Leipsic  Hospital,  justify  the  expectation  that 
sahcylic  acid  may  possess  the  desirable  properties  of  carbolic  acid  with- 
out the  disadvantages  of  the  latter.  On  account  of  its  antiseptic 
proporties,  H.  Kolbe  suggests  the  use  of  salicylic  acid  in  cholera,  etc., 
internally  as  well  as  in  subcutaneous  injection  and  in  the  form  of  clys- 
ters. The  author  has  published  a  process  whereby  this  acid  may  be 
easily  obtained  in  considerable  quantities,  by  heating  dry  carbolate  of 
sodium  in  a  current  of  dry  carbonic  acid  gas,  gradually,  from  100^  C.  to 
220*^  or  250^  C. — Journ.  f.prakt.  Chemie^  New  Ser.^  vol.     pp.  89-1 12. 
W.  Knop  affirms  the  antiseptic  properties  of  salicylic  acid  also  for 
the  germination  of  seeds  and  the  growth  of  young  plants  under  various 
conditions  ;  the  growth  of  mould  is  prevented  until  the  free  acid  has 
been  neutralized  by  the  ammonia,  generated  by  the  decomposition  of 
albuminous  bodies. — Ihid..^  pp.  351-355. 
RESEARCHES  ON  THE  DECOMPOSITION  OF  SOME  SALTS  BY 
WATER.^- 
BY   MR.  DITTE, 
In  a  first  note,  Mr.  Ditte  has  examined  the  action  of  water  on  mer- 
curic sulphate  HgO,S03.  In  contact  with  water  and  at  the  ordinary 
temperature,  the  mercuric  sulphate  becomes  immediately  colored  ;  the 
subsulphate  3HgO,S03  precipitates,  and  the  water  becomes  strongly 
acid.  This  reaction  continues  on  the  further  addition  of  the  neutral 
salt,  until  a  certain  proportion  of  sulphuric  acid  has  been  set  free, 
when  the  sulphate  will  be  simply  dissolved  until  the  liquid  is  entirely 
saturated. 
According  to  the  experience  of  Mr.  Ditte,  water  containing  less  than 
67  grams  of  free  sulphuric  acid  to  the  litre  will,  at  12°  C,  decompose 
the  salt  HgO,S03  ;  but  as  soon  as  it  contains  more  than  67  grams  of 
acid,  it  loses  all  its  chemical  action  on  the  neutral  salt,  and  dissolves  it 
without  decomposition.  In  the  presence  of  an  excess  of  subsulphate, 
some  neutral  salt  will  even  be  reproduced,  so  that^  whatever  the  start- 
ing point  was,  a  liquid  will  always  be  obtained  containing  67  grams  of 
acid,  provided  the  temperature  remains  the  same.     The  liquid,  which 
"'•'Translated  from  "  Journal  de  Pharmacie  et  de  Chimie,"  December,  1874,  p. 
448-450. 
