494  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull. 225. 
Salt  production  of  Utah  and  entire  United  States,  1880-1902 — Continued. 
Year. 
Utah. 
United  States. 
l  sss                                   
Barrels. 
151,  785 
200,  000 
427, 500 
969, 000 
1,  292,  471 
189,  006 
268, 186 
294,  485 
279, 800 
405,179 
266,  250 
236, 135 
249, 128 
334,  484 
417,  501 
Barrels. 
8,  055,  881 
L889                   
8,  005, 565 
1890            
8,  876, 991 
1891            
9,  987,  945 
L892                   - 
11,698,890 
1893           
11,  897,  208 
1894 
12,967,147 
1895         
13,  669,  649 
13, 850, 726 
1897 
15, 973,  202 
17,612,634 
1899 
19,  708,  614 
20,  869,  342 
20,  566,  661 
23,849,221 
1901 
SALT  INDUSTRY  IN  CALIFORNIA. 
Rock  salt  or  brine  from  springs  and  lakes  is  utilized  in  several  Cal- 
ifornia counties,  but  the  greater  part  of  the  salt  production  of  the 
State  still  comes  from  the  solar-evaporation  plants,  working  on  sea 
water,  in  the  counties  of  Alameda  and  San  Diego.  In  recent  years 
almost  90  per  cent  of  the  total  production  has  come  from  Alameda 
Count}^  alone. 
Most  of  the  "  bay  salt"  plants  are  located  on  the  eastern  side  of  San 
Francisco  Bay,  near  its  southern  end  in  the  vicinity  of  Alvarado,  New- 
ark, and  Mount  Eden.  Attempts  have  been  made  to  manufacture  salt 
on  the  west  side  of  the  bay,  but  the  water  there  is  said  to  contain  more 
iron.  For  some  reason,  at  any  rate,  the  plants  on  the  west  side  have 
never  proved  successful. 
Chemical  composition  of  sea  water. — While  differing  slightly  in  vari- 
ous parts  of  the  ocean,  the  chemical  composition  of  sea  water  is  fairly 
uniform.  The  following  average,  given  by  Dittmar,  is  usually  accepted 
as  representative: 
Average  composition  of  the  solid  matter  of  sea  water. 
Per  cent. 
Sodium  chloride  (NaCl) 77.  758 
Magnesium  chloride  (MgCl2 ) 10.  878 
Magnesium  sulphate  (MgSO  J 4.  737 
Calcium  sulphate  (CaS04 ) 3.  (500 
Potassium  sulphate  (K2S04) 2.465 
Magnesium  bromide  (  MgBr) 217 
Calcium  carbonate  (CaC03) . . 345 
