A competent correspondent, residing at Antwerp, writes to the Washington Union that a machine for cleansing cotton seed has lately been invented and operated in that city. From two to three tuns of seed can be cleaned per day by a machine of four horse power, with the assistance of three persons. The cotton surrounding the sccd is taken clean off, and can be sold to carpet manufaqturers and paper makers at from thirty to fifty francs the one- hundred kilogrammesabout $10 the two hundred and twenty Ibs. After the oil is extracted, the cakes remrtining can be sold for the same price as other cakes of oleaginous seeds. The cost of the machinery is said not to be expensive. This is an important invention, and promises to be of great advantage to cot tQn growers.