261 



the ocean had made an irruption in 1726. After 

 great droughts, crystallized and very pure muriat 

 of soda, in masses of three or four cubic feet, are 

 still drawn from time to time from the bottom 

 of the mere. The salt waters of the lake, ex- 

 posed to the heat of the Sun, evaporate at their 

 surface; crusts of salt, formed in a saturated 

 solution, fall to the bottom : and by the attrac- 

 tion between crystals of a similar nature and 

 form, the crystallized masses daily augment. It 

 is generally observed, that the water is brackish 

 wherever meres are formed in clayey ground. 

 It is true, that for the new salt work, near the 

 battery of Araya, the seawater is received into 

 pits, as in the salt marshes of the south of 

 France ; but in the island of Margaretta, near 

 Pampatar, salt is manufactured by employing 

 only fresh water, with which the muriatiferous 

 clay has been lixivated. 



We must not confound the salt disseminated 

 in these clayey soils with that contained in the 

 sands of the seashore, which are advantageously 

 worked on the coasts of Normandy *. These 

 phenomena, considered in a geognostical point 

 of view, have scarcely any thing in common. 

 I have seen muriatiferous clay at the level of the 

 ocean at Punt a Araya, and at two thousand 

 toises height in the Cordilleras of New Grenada. 



* In the bay of Avranches, and in many other parts of 

 Europe. Chaptal, Chimie appliquee aux Arts, t. iv, p. 161. 



