Almost every regular mail arrival from Europe furnishes information of meetings held, or measures taken, for an increased supply of cotton, and an extension of its cultivation in other regions than those whence the largest supplies are now obtained. Just previous to the late monetary panic, cotton had attained to such a high price that British manufacturers of coarse goods found themselves compelled to curtail their operations, and as a consequence, they were greatly incited to devise some other means for securing a larger supply at lower prices. Being dependent on the United States for four-fifths of that which they use, they felt that American cotton was their king, hence they looked to other regions for relief. The city of Manchester being the metropolis of the cotton trade, it has always been the most active in endeavors to widen the sources of its supply, so that its manufacturers should not be entirely under the sceptre, as they now are, of the American monarch. They had for quite a number of years contributed large sums for developing the cotton culture in Hindostan; and Americans experience4 in all the processes of its development—from planting the seed until it was baled for market— were employed to teach tJie natives, and establish its cultivation upon an extensive, economical and permanent basis. These efforts, in their most flattering aspect, never encroached on the power of the American Cotton King; in fact, they proved almost abortive; and the late rebellion in the East Indies has shut out all prospects of relief from the effeminate cotton raisers of Bombay and jBengal. The cotton fields of India, instead of looking white, as was at one time anticipated, are now dark and desolate; but it would seem that the hopes of English manufacturers, though cast down, are not destroyed. With that remarkable tenacity of pursuing a desired object under all difficulties, for which Uncle John is so much distinguished, he has turned his thoughts and eyes from India, and now fixes them upon Africa. The region of Abeokutah seems to attract the attention of the English cotton interest at present. tJon-siderable quantities of tolerable cotton have been raised there and imported to Liverpool; and the natives have beon stimulated in various ways to devote themselves to its cultivation. It might have been supposed that as the price of cotton at present is quite low, in comparison with what it was a year ago, the ardor of the " Cotton Supply Association " in Manchester would have been somewhat cooled in reference to efforts to render themselves independent of the American planters; such, however, is not the case. On the 9th of last month (April), a very large meeting of the society was held, and resolutions adopted, amid much applause, to extend the organization, with a view to more wide-spread and vigorous efforts. The late expedition fitted out with the famous Dr. Livingstone as its chief, has for one of its main objects the encouragement of cotton cultivation in Africa. It is intended to establish various trading stations, and induce the natives to practice agriculture, and the raising of useful native products for foreign export. There are on th&t continent, it is asserted? tracts of country thousands of miles in extent, on which the best qualities of short staple could be raised and sold at a cost far below American cotton. The attempt, therefore, is i to be made to carry the war against American King Cotton into Africa ; with what success the future alone can truly determine. When flax cotton was first made by Cheva- lier Claussen's process, great things were ex-( pected from it, and among others it was to g supersede cotton; but that speculation has not yet dethroned the Cotton King. India, it was also stated, was to break his sceptre, but that speculation has ended in failure also; and so we think will be the case with Africa. The culture of cotton in America is conducted with so much scientific and practical skill, and our inventors are so diligent in endeavors to improve the machines employed in every branch of its manipulation, that we have no doubt but for a great number of years to come, at least, America will be "Cotton King."