Mr Beudant on the Natron Lake)} of Hungary. ^61 
ground, that it was with much difficulty I could proceed to ve- 
rify the principal circumstances which have been described. 
Situation and description of these Lakes. — It is between De- 
bretzin and Nagy-varad, and especially on the heaths in the 
neighbourhood of Kis Maria, that the lakes from which the na- 
tron is obtained may' be best seen. The whole ground about 
them is covered with salicornia^ salsola, and many other mari- 
time plants, which are also collected for the purpose of extract- 
ing the salt by burning. The soil in which these plants grow is 
a micaceous quartzy sand, of a whitish or greyish colour, im- 
pregnated with saline matters. At the margin of the lakes 
there is found a clayey substance, of a grey colour, becoming 
black when moistened, which is always more or less mixed with 
gravel. It appears that it is this matter which forms the soil 
of the parts where the waters are more particularly collected. 
It effervesces with acids, even after the carbonate of soda has 
been removed by lixiviation, which is caused by the presence of 
a little carbonate of lime, the quantity of which was six parts in 
the hundred in the specimens which I collected. These lakes 
or marshes, which in general are very shallow, dry up almost 
entirely in summer ; but when I visited them^ they were filled 
with water, in consequence of the rains which had taken place 
on the preceding days. These waters were turbid, of a greyish 
colour, and presented a slight tinge of red, when, on settling for 
some time, they had depbsited their mud* 
These are the only observations which I have been able to 
make, although I walked along the margins of these lakes du- 
ring a whole day ; but the surface is every where continuous, 
and not a single ravine occurs to enable one to study with more 
precision the composition of the soil. It will be necessary, in 
order to understand the phenomena presented by this soil, to 
dig some pits, or to take advantage of those which have occa- 
sionally been made for wells in the neighbourhood. Buckert, 
who was for a long time employed in extracting the natron, 
and who had opportunities of more particularly examining the 
soil, asserts that the sand sometimes includes pisiform iron- 
ore, that it is never more than four or five feet deep, and 
that it rests on a bed of blue clay. He informs us, al- 
VOL. VII. NO. 14. OCT. 18^^. s 
