264 M. Beudant on the Natron Lakes of Hungary . 
probably accompany the deposits of rock-salt which the waters 
traverse before arriving at the lakes. This explanation appears 
to me also to agree perfectly with the nature of the lakes of Hun- 
gary ; for it is to be remarked, that the richest of them occur in 
the eastern part of the great plain, at a short distance from the foot 
of the calcareous mountains, which form the advanced posts of 
the great mountains of Transylvania; and in the middle, or at 
the back part of which, there are found considerable masses of 
salt. Farther to the west, the plain is filled with deposits 
of coarse marine limestone, similar to those of the neigh- 
bourhood of Paris, which are seen in many parts about Pest, 
and which, probably, extend deep beneath the sand, which covers 
them from observation. The carbonate of lime appears to be, 
. besides, very abundant through the whole plain, since it is daily 
deposited at the bottom of the marshes, where it forms beds of 
greater or less solidity. Lastly, In the plains of Sthulweissen- 
burgh ,and Oldenburg, where natron equally occurs, there still 
exists considerable mountains of compact limestone, or deposits 
of coarse marine limestone with shells. 
Thus, in order to explain the daily formation of natron, it is 
only necessary to admit, as every thing indicatesj that a great 
quantity of muriate of soda exists in all the plains of Hungary, 
But it is, perhaps, possible to go farther, and to trace these sa- 
liferous deposits to those which exist in so great abundance in 
Transylvania and on the frontiers of Marmaros. It is evident, 
in the first place, that the salt deposits of Sziget and of Rhonazek^ 
are prolonged into the valley of Theiss; that they are those which 
occur at Talaborfakoa^ at Sandofalva^ and which produce the 
salt springs of Huszt, Visk, &c. These same deposits occur in 
the valley of Szamos, as well in the mountains which form the 
right side, as in those which are seen on the left, and which 
stretch to the plains of Hungary. After this, it becomes almost 
impossible not to assent to the idea, that the marshes of the 
county of Szathmar, which are found in the same line, and at a 
short distance from the last works, should also have the property 
of furnishing both muriate and carbonate of soda to the same sa- 
liferous deposits, which would form in this place the soil of the 
plain, where they would be necessarily covered with sandy de- 
^ posits. The same necessarily applies to the counties of Szahdtz 
