ECKEL.] 
SALT    INDUSTRY    IN    UTAH    AND    CALIFORNIA. 
495 
Sea  water  contains,  on  the  average,  about  3£  per  cent  of  such  solid 
matter. 
Manufacturing  methods. — While  the  processes  of  evaporating  and 
milling,  as  carried  out  at  the  best  equipped  California  plants,  closely 
resemble  those  already  described  as  in  use  in  Utah,  a  few  differences 
are  worthy  of  note. 
The  most  important  of  these  differences  of  practice  arises  from  the 
difference  in  strength  of  brine.  The  water  of  Great  Salt  Lake  carries 
20  per  cent  or  more  of  salts,  and  has  therefore  deposited  practically 
all  of  its  lime  carbonate  and  gypsum.  The  water  of  San  Francisco  Bay, 
on  the  other  hand,  is  a  relatively  weak  brine,  carrying  probably  about 
3  per  cent  of  salts.  In  evaporating,  it  is  therefore  necessary  to  provide 
for  the  precipitation  of  the  iron  oxide,  lime  carbonate,  and  gypsum. 
Analyses  of  commercial  salts,  California. 
Sodium  chloride  (NaCl) 
Lime  (CaO) 
Magnesia  (MgO) 
Sulphur  trioxide  (S03)  . 
Water 
1. 
Per  cent. 
97.31 
.10 
.48 
.36 
1.55 
1 
Per  cent. 
99.  655 
.125 
Tr. 
.17 
.05 
1.  Crude  salt,  first  evaporation,  1903  crop.     California  fait  Company,  Alvarado.     L.   Falkenau, 
analyst. 
2.  Table  salt,  refined.    Coward  mill,  Oakland  (not  now  in  operation).    L.  Falkenau,  analyst. 
