336 
SOLUBLE  SILICATE  OF  SODA,  EOT. 
animal,  the  dugong  {Kalicore  Australis  or  Halieore  Dugong  of 
Cuvier,)  inhabits  the  rivers  and  bays  of  the  eastern  coast  of 
Australia,  and  many  of  the  islands  of  the  Indian  Archipelago. 
It  feeds  on  the  submarine  algae  and  fuci  of  shallow  waters.  It 
attains  a  length  of  seven  or  eight  feet,  and  is  described  as  some- 
thing between  a  porpoise  and  a  seal.  The  flesh  is  highly  esteem- 
ed as  a  tender  food,  not  unlike  beef,  and  it  yields  an  oil  so  bland 
and  sweet,  so  free  from  disagreeble  flavor  or  odor,  that  it  may 
be  given  in  much  larger  doses  than  cod-liver  oil.  Mr.  W.  Hobbs, 
a  surgeon  practising  at  Brisbane,  Moreton  Bay,  has  used  the  oil 
extensively  in  many  chronic  diseases.  He  is  spoken  of  by  our 
correspondent  as  a  most  intelligent  man,  and  from  his  reports, 
we  should  certainly  conclude  that  the  oil  possesses  all  the  useful 
properties  of  cod-liver  oil.  The  evidence,  to  say  the  least,  is 
sufficient  to  encourage  a  trial  of  the  oil  in  this  country,  and  we 
trust  some  Australian  merchant  will  secure  a  supply  without 
delay. — London  Chemist,  May  1858,  from  Medical  Times  and 
Gazette. 
SOLUBLE  SILICATE  OF  SODA,  WATER  GLASS,  OR  MINERAL  GUM. 
Dr.  Edwards  introduced  specimens  of  "Water  Glass,"  and  a 
solution  of  the  same,  sold  as  "  Mineral  Gum,"  substances  which 
were  being  largely  manufactured  near  Liverpool,  and  applied  to 
several  important  purposes  of  commerce.  The  substance  is  a 
silicate  of  soda,  being  a  transparent  green  glass,  long  known  to 
Chemists  as  "  Soluble  Glass."  It  has  only  recently  attracted 
the  notice  of  manufacturers,  who  now  find  it  possesses  properties 
rendering  it  highly  useful,  and  indeed  remarkable  for  the  variety 
of  its  applications.  It  is  prepared  from  quartz  sand,  and  soda 
ash.  The  glass  is  very  finely  ground,  and  then  dissolved  by  the 
agency  of  hot  water  and  steam.  The  solution  is  then  concen- 
trated to  20°,  30°,  or  50°  of  Twaddle,  and  sold  of  the  strength 
best  adapted  for  the  purpose  contemplated.  A  large  demand 
has  recently  arisen  for  it  as  a  size  for  calicoes,  &c,  in  lieu  of 
British  gum,  the  glaze  being  superior,  and  the  price  (<£6  to  £7  a 
on)  being  lower. 
It  is  also  getting  in  demand  for  soap-making,  being  itself  a 
