There are also large breweries, and the Hop Exchange is a centre of the hop trade.
The "stinking fermentations" occasionally experienced in breweries probably arise from this, the free sulphur being derived from the hops.
In a top fermentation - typical of English breweries - the yeast rises, in a bottom fermentation, as the phrase implies, it settles in the vessel.
Large markets and fairs are held for corn, hops, cattle and sheep; and the town contains some highly reputed ale breweries, besides paper mills and iron foundries.
The main industries are cotton-spinning, flax-spinning, cottonprinting, tanning and sugar refining; in addition to which there are iron and copper foundries, machine-building works, breweries and factories of soap, paper, tobacco, &c. As a trading centre the city is even more important.