^6 M. Beudant on the Natron Lakes of Hungary, 
a considerable quantity of sulphate of magnesia, the decom- 
position of which by the muriate, equally at a low temperature^ 
IS still more easy. Gren discovered that the great quantity 
of sulphate of soda, which formed in the salt basins of Saxony, 
during the winter of 1794, was chiefly owing to sulphate of 
magnesia. It is to be remarked, that there also in fact exists 
much sulphate of magnesia in the plains of Hungary, to which 
little attention is paid. 
Saltpetre . — There exists, in the plains of Hungary, another 
salt, whose origin is perhaps of more di:^cult explanation : this 
is saltpetre, which occurs, as it would appear, in very great 
quantities ; it effloresces also at the surface of the ground in the 
counties of Szathmar, Szabolez, and Bihar, as well as in the 
plains of Stulhweissenburg and Oldenburg : a sufficient quantity 
might be collected to supply all Hungary and Austria. 
In 1802, nearly 7000 quintals were extracted for government, 
although workhouses were not erected for collecting all that 
might be got. 
Huckert thought that this salt must be a mineral production, 
and he was led to believe that there existed a bed of more tlmn 
sixty leagues in length by twenty-five or thirty in breadth. The 
principal facts on which he founded this opinion were, that all 
the wells which have been dug in the eastern part of the great 
plain, afford only nitrous Avaters, and that the saltpetre which 
effloresces at the surface of the ground, occurs in places where 
it does not appear that animal substances could have contributed 
to its formation. I must still dissent from him with regard to 
this; for I observe, on the contrary, that there are in this 
country immense herds of oxen, of buffaloes and horses, which 
must contribute in a great degree to the production of this salt. 
It appears to me still, and even after Avhat Huckert says, that 
the waters of the subterranean springs contain but a very small 
quantity of this salt ; and it would not be surprising were it 
found to be the result of the infiltration of the surface-Avater. 
As to the rest, the existence of saltpetre in the midst of heaths, 
and in a multitude of other circumstances, is a phenomenon 
which still requires investigation. We know that this salt forma 
in abundance in all places where animal and vegetable matters 
in a state of decomposition are found united ; but it is not cer^ 
