The manufactures of this class include aerated waters, beer,.
Produced in non-aerated water it is probably an oxide.
Many substitutes have been proposed for cork as a stoppering agent; but except in the case of aerated liquids none of these has recommended itself in practice.
For aerated water bottles several successful devices have been introduced.
As a river-port and the terminus of railways from Varna and from Sofia via Trnovo, it has much commercial importance; and it possesses tobacco and cigarette factories, soap-works, breweries, aerated water factories, dyeworks, tanneries, sawmills, brick and tile works and a celebrated pottery.