This portion of South America, in the summer of 1824-25, was most seriously annoyed by locusts; the memory of the oldest inhabitant cannot recollect such a swarm. The air was darkened, and the ground strewed, with the millions of those devouring insects: a north wind brought them down from the Parana, like a snow-storm. The fruit trees, plants, &c. dreadfully suffered. The inhabitants have an idea, that, by ringing bells, beating tin saucepans, and other noises of this description, locusts can be frightened away. An easterly wind, rain, and cold weather, are, I believe, their only destroyers. The months of December, 1824 and January, 1825, were foggy, dry months, the wind constantly from the north; and, for want of water, a great mortality took place in the country among the cattle. Mushrooms and water-cresses are not very plentiful: they are more found in the neighbourhood of Ensenada; as are also leeches, for which doctors give a good price. The flowers reared in this country must likewise yield, in beauty and sweetness, to our own: we do not see the polyanthus, moss rose, and many others that strew their beauties over the British isles. * * * * * POPULATION.--The province of Buenos Ayres, which extends nearly 500 miles in length, with a breadth undefined (perhaps equal to its length), has only a population of about 150,000 souls; and Patagonia, which is under the same government, 1000. It is estimated, that in the population of Buenos Ayres, there are five females to one male. If this be correct, some ladies are likely to come under the horrid list of old maids. That more female births take place in comparison with those of Europe cannot be doubted. I know families of eight, nine, and ten daughters, and perhaps one son. The causes of such disproportion, I must leave the natural philosophers to develope. * * * * * TRADE and MANUFACTURES.--From its extensive produce, Buenos Ayres will ever command attention in a mercantile point of view. The exports consist of ox hides of all descriptions, horse hides, horse hair, wool, tallow, nutria skins, horns, chinchilla skins, salted beef, and silver in hard dollars and bars. The quantity of European goods annually imported is very great: I am surprised how they find vent for them. The cargoes brought from Liverpool, of manufactured goods, of Manchester, Glasgow, &c. are of considerable value, often from 70 to 80, and £100,000. The following is a list of square-rigged merchant vessels that entered the port of Buenos Ayres in the years 1821, 1822, 1823, and 1824:-- In 1821. In 1822. In 1823. In 1824.