Sentence:  As soon as the syrup passes into the coolers, and is met by the air, it grains, and the molasses at once escapes through the sieves into a cistern below. It is then white or loaf sugar of the finest kind—clear, clean, and as white as snow. When cool, it is taken out, packed into <WSD>hogsheads</WSD>, and is ready for market. 
Meaning of the word marked with <WSD> tags:  A large barrel or cask of indefinite contents, especially one containing from 100 to 140 gallons.