492 
CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903. 
[BULL.  225. 
Analysis  of  separated  material  caked  on  drier. 
Per  cent. 
Silica  (Si02 ) 0.  31 
Alumina   (A1203) 
Iron  oxide  (Fe203). 
Lime  (CaO). 
Magnesia  ( MgO) 
Potash  (K20) 
Soda(Na20) 
Sulphur  trioxide  (S03) 
Chlorine  (CI) 
Water  of  combination 
Moisture 
.10 
.67 
4.66 
2.41 
27.41 
13.11 
43.  05 
7.03 
1.58 
Total 100.33 
When  these  constituents  are  combined  in  the  most  probable  manner, 
it  will  be  seen  that  this  separated  material  contains  about  70  per  cent 
of  sodium  chloride  and  14  per  cent  of  magnesium  sulphate,  with  lesser 
amounts  of  potassium  sulphate,  etc. 
Composition  of  commercial  salt. — The  following  are  anatyses  of  salt 
manufactured  from  brine  of  Great  Salt  Lake: 
Analyses  of  commercial  salts,  Utah. 
5. 
Silica  (Si02),  etc 
Sodium  chloride  (NaCl) 
Calcium  chloride  (CaCl2) 
Magnesium  chloride  (MgCLJ. 
Calcium  sulphate  (CaSOJ  ... 
Magnesium  sulphate  (MgS04) 
Water 
1. 
2. 
3. 
4. 
Per  cent. 
Per  cent. 
Per  cent. 
Per  cent. 
0.214 
0.472 
0.201 
0.102 
98. 101 
98.  300 
98. 121 
98.  407 
.322 
.345 
.311 
.371 
.000 
.000 
.000 
.000 
.364 
.680 
.422 
.650 
.021 
.042 
.022 
.  030 
.952 
.158 
.911 
.442 
Per  cent. 
0.007 
99.  927 
Tr. 
Tr. 
.058 
.000 
.  008 
1.  Coarse  salt,  Jeremy  Salt  Company.     J.  E.  Talmage,  analyst. 
2.  Table  salt,  Jeremy  Salt  Company.     J.  E.  Talmage,  analyst. 
3.  Crude  salt,  Inland  Crystal  Salt  Company.     J.  E.  Talmage,  analyst. 
4.  Salt,  Inland  Crystal  Salt  Company.     J.  E.  Talmage,  analyst. 
5.  Table  salt  (refined),  Inland  Crystal  Salt  Company.     H.  Harms,  analyst. 
Early  history  of  the  industry. a — The  history  of  salt  manufacture 
from  the  waters  of  Great  Salt  Lake  begins  immediately  upon  the 
arrival  of  the  Mormons  in  Utah  in  1847.  In  the  earlier  years  of  the 
industry  the  only  salt  harvested  was  that  obtained  from  the  evapora- 
tion, during  summer,  of  the  water  contained  in  little  lagoons  or  natu- 
ral basins  along  the  shore  of  the  lake. 
The  early  settlers  were  supplied  in  this  way  until  about  1860,  when  the  idea  was 
conceived  of  making  dams  which  would  hold  large  quantities  of  water  in  low  places, 
for  evaporation.     These  ponds  were  flooded  in  the  spring  and  the  salt  deposited  dur- 
aA  more  detailed  .liscussion  will  be  found  in  the  Nineteenth  Ann.  Rept.  U.  S.  Geol.  Survey,  pt.  6, 
1898,  pp.  608-609. 
