natural history of soda.

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SOJDA.

PART LXVIII.

' SECT. I.

NATURAL HISTORY OF SODA.

The name of soda is given to the next alcali, which greatlyresembles potash. Hitherto we are not better acquainted withthe nature of soda than with that of potash, being equally un-certain whether it previously existed ready formed in the vegeta-ble ; or if it be a combination of certain radicals effected duringthe process for obtaining it.

Soda frequently occurs in the mineral kingdom, united withsulphuric, muriatic, and boracic acids ; it is also found in largequantities in Egypt, combined w-ith carbonic acid. It appears tobe deposited in large impure masses, under the surface of theearth, in various countries, from which it is extracted by run-ning water. Thus it is found after the spontaneous evaporationof the water, mixed with sand in the bottom of lakes in Hun-gary; in the neighbourhood of Bilin in Bohemia ; and in Swit-zerland. It occurs also in China, and near Tripoli in Syria,Egypt, Persia, and India. It frequently oozes out of walls andcrystallizes on their surface.