NOTE  ON  OZONE. 
463 
The  process  adopted  in  the  manufacture  of  kelp  is  well  known 
to  have  two  very  serious  objections,  the  volatilization  of  a  por- 
tion of  the  iodine,  and  the  reduction  of  a  part  of  the  sulphuric 
acid,  giving  rise  to  the  presence  of  sulphides,  hyposulphites,  and 
sulphites  in  the  product.  The  following  process  has  been  tried 
on  the  small  scale  with  marked  success.  The  weeds  are  boiled 
with  a  small  quantity  of  water,  the  liquor  evaporated  to  dryness, 
and  the  residue  charred  very  carefully.  The  mass,  dissolved  in 
water,  gives  a  colorless  solution  which  is  quite  clear  from  sul- 
phides, and  may  be  at  once  boiled  down  to  extract  the  salts,  as 
in  an  iodine  work,  or  simply  evaporated  to  dryness,  and  sold  as 
kelp.  I  am  enabled,  by  the  kindness  of  Dr.  Wallace,  to  give 
an  analysis  of  kelp  so  prepared,  chiefly  from  Laminaria  digitata. 
Sulphate  of  potash 
14-35 
Chloride  of  potassium  . 
42-49 
Chloride  of  sodium 
36-47 
Sulphate  of  soda 
3-90 
Iodide  of  sodium  . 
L78 
Carbonate  of  soda 
1-01 
100 
London  Cliem.  Gaz.  June  1,  1859. 
NOTE  ON  OZONE. 
By  Thomas  Andrews  M.D.,  F.K.S.,  and  P.  G.  Tait,  M.A.,  F.C.P.S. 
Since  the  publication  of  their  "Note  on  the  Density  of 
Ozone"  (Chemical  Gazette  for  August  15,  1857),  the  authors 
have  been  occupied  with  an  extended  investigation  into  the  na- 
ture and  properties  of  that  body.  The  inquiry  having  proved 
more  protracted  than  they  anticipated,  they  have  thought  it 
proper  to  send  to  the  Royal  Society  a  brief  notice  of  some  of 
the  more  important  facts  which  they  have  already  observed, 're- 
serving a  description  of  the  methods  employed,  and  of  the  de- 
tails of  the  experiments,  for  a  future  communication. 
The  commonly  received  statement,  that  the  whole  of  a  given 
volume  of  dry  oxygen  gas  contained  alone  in  an  hermetically 
sealed  tube  can  be  converted  into  ozone  by  the  passage  of  elec- 
