Extraction of Suits from Sea-Water. 99 



tioti, as well as of the method employed for the working of the 

 mother liquors. I have to express my great obligations to my 

 distinguished colleague, Mr. Balard, of the Academy of Sciences, 

 who most kindly furnished me with every information respecting 

 the processes of his invention which are there applied, and also Mr. 

 Agard, the enlightened and scientific director of the saline. 



The first condition for the establishment of a salt work is a low, 

 broad, level ground on the border of the sea, which can be protected 

 by dykes from the action of the tides, and as these are considerable 

 on the' Atlantic coast and insignificant in the Mediterranean, the 

 arrangements required in the two regions are somewhat different. 

 In both, cases however the high tides are taken advantage of to 

 fill large and shallow basins with the sea-water, which there de- 

 posits its sediments, becomes warmed by the sun's rays and begins 

 to evaporate. From these reservoirs it is led by a canal to a series 

 of basins from ten, to sixteen inches in depth, through which it 

 passes successively, and where by the action of the sun and wind 

 the water is rapidly evaporated, and deposits its lime in the form 

 of sulphate. It then passes to another series of smaller basins where 

 the evaporation is carried to such a point that the water becomes 

 a saturated brine, when its volume being greatly diminished, it is 

 transferred to still smaller shallow basins called salting-tables, 

 where the salt is to be deposited. In the salines of the Atlantic 

 coast, the different basins are nearly on the same plane, and the 

 water flows from one series to the other as its level is reduced by 

 ■evaporation. In the large establishments of the Mediterranean, 

 the system is different ; the basins are constructed at different 

 levels, and the waters having passed through one series, are raised 

 by wooden tympans or drums from eight to sixteen feet in diame- 

 ter (moved by steam or horse power), and conducted into the 

 other basins. These differences of level establish a constant cur- 

 rent, and in this way greatly promote the evaporation. 



But in whatever manner the process is conducted, the concen- 

 trated brines, making 25°of Beaume's areometer, are finally con- 

 ducted to the sa'ting tables, where they begin to depo^ite their 

 salt in the form of crystalline crusts, which are either collected 

 with rakes as soon as they form, or as at Berre, allowed to accu- 

 mulate at the bottom, until they form masses six or eight inches in 

 thickness. The concentration of the brines must be care- 

 fully watched, and their density never allowed to exceed 

 28°5, otherwise a deposit of sulphate of magnesia would 



