114 M. BeudanCs Travels in Hungary. 



on the surface of the soil, and must be attributed to the de- 

 composition of muriate of soda. This takes place in different 

 ways, varying only in the promptitude with which the operation 

 is performed. Advantage has been taken of it, for the fabriea*- 

 tion of the sub-carbonate of artificial soda, and applicable 

 successively, to a number of processes, more or less profitable. 



So also it is, in the decomposition of muriate of soda, that 

 we are to look for the origin of nation. M. Berthollet accounts 

 for the daily formation of this salt, in the valley of natron lakes 

 in Egypt, in a probable manner. He imputes it to the reciprocal 

 action of muriate of soda, and carbonate of calx, aided by the 

 efflorescence, which determines the successive separation of the 

 carbonate of soda, and thus allows a continual and indefinite de- 

 composition to take place. Ocular inspection will show that the 

 lakes contain a great quantity of muriate of soda, lodged in 

 a calcareous soil, the rock of which pierces here and there the 

 sands which cover it. We meet, likewise, with strata of gypsum, 

 which probably accompany the depots of rock-salt, which the 

 waters perforate before they enter the lakes. This explication 

 very well cigrees with the nation lakes of Hungary, for the richest 

 are found in the eastern part of the great plain, at a little dis- 

 tance from the calcareous mountains that form the advanced 

 posts of the high mountains of Transylvania. In the middle of 

 those, or behind them, are considerable masses of salt ; more to 

 the west the plain is filled with rough calcareous depots, like 

 those in the environs of Paris. The carbonate of calx seems 

 very abundant through the whole plain, and forms daily deposits 

 of strata, more or less dense, at the bottom of the marshes. 



Every thing indicates that there is much muriate of soda in all 

 the plains of Hungary. Most of the saliferous argiles, that I 

 have had occasion to observe, as well as the argilous masses on 

 the borders of the natron lakes, contain a quantity of carbonate 

 of calx, and all are, more or less, sandy. These mixtures natu- 

 rally prepare the decomposition of muriate of soda ; one, by 

 directly furnishing the substance that is to produce it, and the 

 other, by rendering the mass more porous, and thereby facilitating 

 the efflorescence of the natron. Jf the decomposition does not 

 operate in the mines, it is from a scantier supply of heat and of 

 moisture, and especially of fresh air. It is evident, tl;at in tracing 

 the course of these plains, where muriate of soda is constantly 

 found in the waters, they lead, in an unvarying continuation, to 

 the masses of salt that form the object of considerable mineral 

 works. 



Another salt is also found in the plains of Hungary, more diffi- 

 cult still, perhaps, to explain, salt-petre, which is found in very 

 large quantities in the plains of Hungary. It effloresces, also, 



