SOUTH AMERICA.

The arrival of the steamer Georgia, on the 7th of September, put us in possession of later news from the Pacific coast of South America. In Guayaquil a military outbreak, excited, so far as appears, solely by personal resentments, has resulted in a complete change of the administration. The President, Gen. Neuva, left Querto on the 17th of July for the purpose of visiting his family at Guayaquil. On approaching that city he was met by a military cavalcade, ostensibly for the purpose of escorting him in: but he was immediately seized by them, and hurried off to sea in a vessel lying in the river; the destination of the vessel, and the fate of the captive were unknown. Gen. Urbina immediately entered upon the administration of affairs. In Chili, Don Manual Montt has been elected President by an overwhelming majority. He was understood to be in favor of internal improvements and of a more effectual promotion of education. The Copiapo Railroad was to be opened in September. Congress was in session the last of July, but no important business engaged its attention. In 1850 the public revenue amounted to $4,334,314, and the expenditures to $3,610,837, including over three hundred thousand dollars remitted to England to pay interest on the loan contracted there. The whole English debt is now about seven millions of dollars. A very severe storm swept the harbor of Valparaiso in the early part of July. The damage to shipping, both Chilian and American, was very considerable. In Bolivia, the decree allowing foreign goods to be entered at a lower duty from vessels that had not touched at other ports, has been revoked. In Peru, Congress was still in session. The legislative and executive branches of the government are represented as being on the best of terms with each other, so that affairs are conducted with a good degree of promptness and efficiency. A bill has been urged in Congress for the greater extension of the freedom of trade, and another to prohibit the circulation in that Republic of Bolivian money. Several bills of decided local importance engaged the attention of Congress. There has been during the past year a very large export from Chili, chiefly of wheat and flour, amounting to two hundred thousand dollars more than during the previous year. In New Grenada, it is said there are new disturbances. The government levied a forced loan, and further decreed that the friends of the government should be exempted from its payment. In several provinces the decree had the effect of converting nearly the whole population into a government party; but in Bogota and Carthagena it had the opposite effect. Arrangements were in progress for an extensive revolt, and it was said that it had commenced at Bogota, but with what result is not clear.

From Mexico later advices have been received,—to August 22d from the capital and the 29th from Vera Cruz. The hostility of the government to the fulfillment of its treaty stipulations concerning the Tehuantepec Canal continues unabated; and it is stated that two vessels sent from New Orleans to commence the work were seized by the Mexican authorities. The financial condition of the country continues to engross attention, but no one of the numerous projects offered for its relief seems likely to be adopted. The ministerial plan calling a convention of the Governors of the several Provinces, meets with very little favor. The appropriation of the Church property to the necessities of the Government has been warmly recommended by some of the public journals. The estates of the clergy and of various religious incorporations amount to $50,000,000. This sum, which has been accumulating in unproductive hands for the last three centuries, it was maintained, would save the country from bankruptcy and ruin.

The Mexican Senate has passed an act recommending a general Confederation among the Spanish American republics. A plan for accomplishing this object is detailed, of which the most marked features are a general Congress, a uniform political system, a general act of navigation and commerce, an alliance offensive and defensive, and a tribunal for the settlement of differences. The project is a good one, but there seems to be little chance of its being carried out. In Durango, a popular commotion occurred on the 17th of August, in consequence of the high price of corn, but it was quelled without bloodshed, by an order from the government compelling the holders of the article to reduce its price. In Vera Cruz, on the 21st, a very large number of the inhabitants, including some of the National Guard, assembled to ask of the local government relief from recent and very oppressive taxes. Some of the soldiers were ordered out to oppose them, when the people retired to their houses and prepared for defense. A brisk action ensued in which several were killed, but quiet was restored by the announcement that the local government had yielded to the popular demands. President Arista's birthday was celebrated on the 25th of July. He has dissolved a club formed for the purpose of regulating the annual celebration of Mexican Independence, as some of its regulations did not meet his approbation. An abortive attempt at a pronunciamiento in favor of Santa Anna has been made at Guanajuato. The plot, which probably had plunder for its chief object, was discovered before it had come to maturity, and the leaders were taken into custody. A revolution has broken out in Chiapas, aiming at the abolition of the internal Custom Houses. Col. Munoz, commanding the battalion of Guerrero in Tehuantepec, was ordered to proceed to Chiapas and aid the government party in the suppression of the rebellion. His men began to desert soon after the commencement of the march, and before he had advanced fifty miles from Tehuantepec he had not more then seventy men. The revolt is headed by Meldono, one of the wealthiest and most influential men in the State.

A good deal of excitement has been produced in Mexico by the publication of the letters of Payno, to the President of the Committee of Mexican bond-holders in London. It seems that the assertion of Payno that he was Chargé d'Affaires of the Mexican Legation in London, and was commissioned to adjust certain matters pending in Europe, was entirely destitute of foundation. On the publication of the letter containing these statements, and others equally untrue, a resolution was introduced into the Chamber of Deputies, inquiring by what authority Payno had received the appointment of chargé, and how much money was appropriated to his mission. The Minister replied that Payno had never received the commission from the Government, but that $20,000 had been applied to defraying the expense of the voyage. In consequence of this information, a complaint was lodged against the former Minister of Finance, and of Foreign Relations. The affair was also taken up by the Senate, which has recommended Lacunza as Minister to England.

From Montevideo we have intelligence to the first of July. The aspect of affairs in Brazil and Buenos Ayres was by no means pacific. The Brazilian force under Admiral Grenfell, the Commander-in-chief, had penetrated the waters of the Uraguay, and were stationed at commanding points along the north bank of the river. The disaffection of the province of Entre Rios had been followed by that of Corrientes, warlike preparations were in train; and every thing threatened a general outbreak. The mediation of Great Britain had been accepted by Gen. Rosas. The slave-trade on the coast of Brazil was at a low ebb, a deep laid scheme for its revival having been defeated by the British squadron. Only 1000 slaves were landed during the first six months of 1851, while no less than 20,000 were landed in the same period of 1848.

From the island of Hayti our advices are to the middle of August. Every thing was then quiet. The Emperor had returned to Cape Haytien from his tour, having crossed the Dominican frontier without being molested, and it was reported that the difficulties between the Dominican and Haytian governments have been amicably settled.

An eruption of the long dormant volcanoes of the Pellée Mountain, in Martinique, took place on the night of August 5. It was accompanied with a noise similar to the approach of thunder, and with a strong vibration that was felt to a considerable distance. The town of St. Pierre, as well as all the surrounding country, was covered over with gray ashes. The population of Prêcheur were obliged to flee from their homes, and to take refuge in St. Pierre. There was no shock of an earthquake.