Corn also was an article of export from Buenos Ayres during the general war in Europe, and is again beginning to be exported to Brazil--as is shown by the account of the exports in 1837. It is of an excellent quality, and might be grown to any extent. Mules, horses, and asses have at times been shipped in large numbers for the West Indies and for the Isle of France, and have been sold there at an enormous profit. In the short notices given of the provinces of the interior, I have given such accounts of any other of their native productions as I could collect. The silver and gold mines of Cordova, La Rioja, Mendoza, San Juan, and Salta, may eventually become productive; and, when an intercourse is once more permitted with Bolivia through the interior, it may be expected that some portion of the precious metals produced there also will, as formerly, find their way to Buenos Ayres. In old times, not only were the rich and populous provinces of Bolivia exclusively supplied through the Rio de la Plata with all such articles as they wanted from Europe, but they took from the lower provinces a variety of useful productions of their own, for all which they paid in gold and silver. Of mules alone upwards of 60,000 were annually sent to Potosi from the provinces of Tucuman and Santa Fé. This internal trade, once of so much importance to the people of the intermediate provinces, was annihilated in the struggle for establishing the independency of the Republic; for, Bolivia remaining to the last in the hands of the Spaniards, of course all commercial intercourse was prohibited with the provinces of La Plata, which had thrown off the yoke of the mother-country. To this may be ascribed in great measure the extreme poverty and backwardness of many of those provinces at the present day. Salta, Tucuman, Cordova, Santa Fé, and Paraguay, lost the best markets for their native produce; whilst the people, dragged from their pastoral and agricultural pursuits in the first instance to fight against their old masters, and afterwards to destroy one another in support of the ephemeral authorities which succeeded them, naturally contracted such unsettled and disorderly habits as it will require many a year of domestic peace and better government to wean them from. To time, and a continuance of those blessings, as I have elsewhere said, we must, I believe, look for the remedy of these evils, and for any material improvement in the condition of the interior provinces of the republic. HORSES AND CATTLE. In connexion with what I have said upon the trade of Buenos Ayres, a brief notice of the origin and extraordinary increase of the vast herds of horses and cattle which at present constitute so large a portion of the riches of Buenos Ayres, may perhaps be not uninteresting to some of my readers.