TREMENDOUS MEETING OF THE SIOUXRESERVATION.After Eloquent Speeches by Their Chfefo They Vote to a Man to Refuse to Accede to the Recent Act of Congress—Chiefs* Speeches.Standing Rock Agency, Dak., July 24 —All is excitement on the Sioux reservation. Never since the granting of the great tract of land to the Indians at the close of the Sioux war, have the Indians been so thoroughly awakened or the white settlers so deeply interested. It has been supposed by a great majority of the reading: people that the Sioux reservation, containing 22,000,000 acres of land, was open for settlement by the recent act of congress, but the clause making it necessary to secure the consent of three-fourths of the Indians may keep the land from the public domain for many years. The commission appointed by President Cleveland to confer with the Indians has arrived.Nearly the entire 5000 Indians of this agency, are camped within two miles of Fort Yates, and additions to their numbers are arriving hourly. Without regard to the merits of the proposition made by the government and with no definite understanding of the proposed treaty, the tribes gathered here oppose the opening of the reservation. SittiDg Bull is the only well known Indian not present, and he will be brought. He left the agency for a hunt, but it is believed that the sly old trickster has been at work among the Indians of other agencies, sowing seeds of discord and urging them to oppose the measure.The Indians called a council Sunday, and in the center of their vast city of tents, which were pitched at daylight Sunday morning, they formed the circle, which was composed of wagons, ponies and nearly 5,000 Indians. The Indians selected Chiefs Gall, John Grass, Mad Bear, Big Head and Running Antelope for their orators at the commission conference.John Grass, one of the head chiefs, was the first to speak. He advised the Indians to be careful in what they say to the commission, and, no matter what is said, to make no decision until mature consideration. He said:“The treaties made before by the whites have been broken by them. I think these men sent out by the Great Father to make this treaty about our land have come for some purpose. The government will support us for twenty-five years, and after that time we will have to pay taxes and will be poor.”