SALT ANALYSES 63 



Wyoming; Genesee 



Valley Brine. Valley Brine. 



Specific gravity 1.20446 1.1S91 



Calcium sulphate 0.4430 0.3780 



Calcium chloride 0.1380 0.1913 



Magnesium chloride 0.0530 0.1897 



Pure salt 25.7110 24.1221 



Water 73-655Q 75-"8g 



99.9500 100.0000 



The following two analyses of the same brines after the 

 lapse of considerable time exemplify the above statement: 



Wyoming Genesee 



Valley Brine Valley Brine 



Specific gravity 1.1924 1.20446 



Calcium sulphate 0.433 percent. 0.407 percent. 



Calcium chloride..., 0.069 " 0.140 " 



Magnesium chloride Q-I43 " 0.322 " 



Pure salt 25.008 " 25.564 " 



Water 74-347 " 73-567 



100.000 100. 000 



Before considering the special advantages of the various 

 methods it is but proper to offer a few general remarks on 

 evaporation. Water when it comes in contact with air 

 yields vapor and the amount of the latter is always depend- 

 ent on the temperature of the former. The formation of 

 vapor always takes place on the surface of the water so 

 long as the boiling point is not reached. If spontaneous 

 or assisted by artificial means and it can only occur with 

 the assistance of heat, and if there is not a direct outside 

 source for this heat it is extracted either from the parts sur- 

 rounding the water or from the latter, thereby reducing its 

 temperature. 



When the formation of vapor takes place, not only on the 

 surface of the liquid but also within it at the bottom and 

 sides of the vessel exposed to a source of heat, the liquid 

 boils. In evaporation the formation of vapor takes place 

 on the surface ; in boiling within the liquid. The former 

 is a slow, the latter a quick method of evaporation. When 

 water is heated in an open vessel to its boiling point, its 



