There have been several arrivals from California, and by every one evidence has been furnished of a very unfortunate condition of affairs. Dissatisfied with the manner in which justice is executed, or perhaps with a view to the complete overthrow of the government, large numbers of men have associated themselves at San Francisco and elsewhere, and assumed all the functions of a magistracy, treating the constituted authorities with contempt, and, in secret assemblies, deciding questions of life and of all the highest interests of society. By their directions, several persons accused of crimes have been murdered, and all the officers of the law have been set at defiance. In other respects, the news from California and other parts of the Pacific coast is without remarkable features; the general prosperity continues in mining, agriculture, and trade; and such is the energy of the inhabitants of that city, that San Francisco has nearly recovered from the effects of the disastrous fires with which it has been visited. The arrival at New-York, on the 13th of August, of the steamer Prometheus, in 29 days from San Francisco, by the new route of Lake Nicaragua and the river San Juan, establishes the practicability and advantages of this route. The shortest trip ever made by the Panama route, it is said, was in 31 days. CUBA. The people of the United States have been kept in a state of excitement during a portion of the last month by reports of a revolution in the Island of Cuba. It is not yet possible to discover very clearly, what are the facts, but it is certain, that there were insurrectionary movements commencing about the 4th of July, in several parts of the Island; that they were badly planned, and inefficiently executed, and that the whole attempt, having caused the ruin of a vast number of persons, is at an end, and has resulted in the firmer establishment of the Spanish authority. BRITISH AMERICA. The Provincial Government persists in its refusal to concede the navigation of the St. Lawrence to foreign vessels till it obtains an equivalent from the United States. A motion against removing the Executive Government to Quebec, until after the expiration of four years from the time of its removal to Toronto, has been negatived the House of Commons by a vote of 48 to 12. It is believed that the removal will be decided on during the present season. MEXICO. The financial embarrassments of the government and people engross the general attention, and though it has been believed that a scheme of administration for augmenting the revenue would be successful, yet the country is so unsettled, and the dissatisfaction with the government so common, and the spirit of revolution so diffused, that only confusion and accelerated ruin can very reasonably be predicted of the country. Insurrectionary movements by parties having in view the recall and dictatorship of Santa Anna, have been put down in Chiapos and Tobasco. SOUTH AMERICA.