--Boston Post.Some excitement was created by two rumors--one of which was to the effect that he had purchased tickets over the Boston and Worcester Railroad for two slaves accompanying him, and the other, that the lieutenant had uttered treasonable sentiments in State-street. The first was unfounded, but it caused considerable excitement in the streets, and an excited mob rushed to the Worcester deot to prevent the slaves from being carried away. Others rushed to the State House to ask Governor Andrew to have Lieutenant Brown arrested, but they were unable to obtain an interview with his Excellency. While in State-street, Lieutenant Brown is charged with having stated that he was going to his plantation, and should fight for the, flag he found flying over it, and for his native State. His remarks caused some angry feelings, but he was not molested. Application was made to District Attorney Woodbury for a warrant for the arrest of Brown, but after hearing the statements of witnesses, he said he had no authority to issue a warrant under the proclamation of the President, as rebels by that proclamation were allowed thirty days to lay down their arms. He advised Mr. W. L. Burt, who was acting in the case, to apply to Governor Andrew, who at once commanded his arrest, and by the following note from the Mayor it appears that Lieutenant Brown was placed under arrest:
Before his arrest, Lieutenant Brown removed his baggage from the Tremont House, and was taken in a coach to unknown quarters. In the meantime, a crowd visited the Worcester depot, where a portion of Lieutenant Brown's baggage was, and broke it open, but finding no materials of war, disturbed it no farther.
