SAN FRANCISCO, Aug. 14, 1855.

FREDERICK DOUGLASS: SIR:—I resume my pen to give you a sketch of our doings and sayings politically. Nothing has transpired since my last of importance. The Know Nothings held a Convention for the purpose of nominating State officers and erecting a platform. The latter is literally Know Nothing, and "say nothing." It is a platform of "flourishing sentences and idle words," devoid of meaning or common sense. The "Union saving plank" is weak. The common sense of it is, "they would stop all anti-slavery discussion." Their nominee for Governor, W. Neely Johnson, is their strongest man, and his strength consists (so the papers say) in his political obscurity and respectability of character; the latter was not, until recently, considered a necessary qualification for office.

The colored people celebrated the Anniversary of British Emancipation quite spiritedly in this city. The celebration took place at Russ Garden, a short distance from the city. The exercises were varied and appropriate—orations, recitations, reading of the emancipation act, dancing, &c. Dancing, although not in the programme, was evidently more enjoyed than anything else. With a majority of the colored people in this city, dancing is the acme of human happiness. It is impossible to draw out a respectable assembly in point of numbers, unless dancing is announced. It is time, circumstanced as we are, to stop this folly—that is, to the extent it is carried on among us. Every geography and spelling book gives us this characteristic, "When the sun goes down, all Africa dances." The negroes, as a race, are remarkably fond of dancing. Let us throw aside these senseless graces and frivolities, and expend the time and money in improving our minds and dignifying our characters.

In Placerville (a mining town) the colored people celebrated the day sensibly and appropriately—not with their heels, but with their heads. The Rev. Mr. Ward was the orator on the occasion, and acquitted himself most happily. The Sacramentans also celebrated the day with speaking and other exercises.

Scenes are being enacted in Amador and Calaveras counties of the most bloody characer. A band of Mexican banditti murdered some Americans, among them women and children. This so exasperated the people, that they have commenced a war of extermination against the Spaniards. Some thirty Mexicans have been hung without judge or jury. The Mexicans, on the other hand, retaliate fearfully. The Americans have sown the wind, and they are reaping the whirlwind. I apprehend the Americans will get the worse of it in the long run. Mexicans are not the forgetting and forgiving race the "blacks" are.

J. C. Woods (principal partner in the defunct concern of Adams & co.) has decamped for parts unknown. He left a card which stated that he had left for the East, for the purpose of setting his affairs; but this is known to be false. It is probably that visions of the State Prison troubled him. "How has the mighty fallen!" This man, a few months ago, was the most opulent banker in this State, and a condidate for Senatorial honors. Now he is a miserable fugitive, "fleeing when no man pursueth."

We are holding a series of meetings in this city, of political character, but no practical good can result from them. The time is consumed in idle and unprofitable discussion, and were it otherwise, the result would be the same. Remonstrances and prayers are futile. We cannot arouse their fears (the whites) by the one, and they have no hearts nor consciences to be affected by the other. The cold word "interest," is the "" that will move the world. All the colored people in the State have not as much political influence as one "naturalized Irishman." What, then, is to be done? We must acquire an influence that will purchase the removal of our disabilities. In a word, we must become moneyed people and purchase our rights. What is the use in demanding our rights unless we have the means to enforce the demand. If money fails, then we had better take the advice of the New York , and go to Africa; but this is an idle digression—Our rights will be given to us when it is no longer the interest of our oppressors to withhold them. This is so apparent, that it is useless to illustrate.

The steamer Sonora is several day over due, and it is feared some accident has happened her.

Respectfully,

NUBIA.