July following. The value of the domestic exports for the year ending June 30, 1851, show an increase of $43,646,322, which is owing to the high price of cotton during the first half of the year, and the price of which has since declined one-half. The value of the exports of breadstuffs is only $21,948,653 against $26,051,373 in 1850, and $68,701,921 in 1847--our largest year of export in that department of trade. In rice the decrease this as compared with last year in the export, is $460,917, which with the decrease in the value of tobacco exported, makes an aggregate decrease in the two articles of $1,156,751. From these premises the President draws the conclusion, that the favorable results anticipated by the advocates of free trade from the adoption of that policy have not been realized. The case of Mr. Thrasher, alluded to in our last, is the subject of a letter from the Secretary of State to our Minister in Madrid, under date of December 13. Mr. Webster directs efforts to secure Mr. Thrasher's release from imprisonment Mr. Thrasher was sent to Spain on the 24th November. An important violation of the stipulations of our last treaty with Great Britain occurred in the harbor of San Juan on the ---- of November. The steamship Prometheus, an American merchant vessel, plying between New York and San Juan de Nicaragua in the California trade, was levied on by the municipal authorities of San Juan or Greytown, for certain port charges established by direction of British agents, as under the government of the Indian or negro king of Mosquito. These charges the Captain of the Prometheus refused to pay. A British vessel of war, however fired on her twice, and after, under the peremptory orders of the Captain of the brig, the Prometheus had returned to her anchorage, he compelled her, under threats, to extinguish her fires, and place herself at his mercy. The pretended dues were at length paid under protest, and the facts in the case were communicated to Congress in a Message from the President on the 17th. Commodore Parker has been ordered to repair at once to the harbor of San Juan, with directions to protect all merchant vessels from such surveilance in future, of which he is to notify the British officers on his arrival. The trial of the persons arrested for taking part in the outrages at Christiana, in Pennsylvania, was commenced in Philadelphia on the 24th of November, before Judges Grier and Kane, in the United States Circuit Court, and on the 12th of December it was brought to a close by the acquittal of the prisoners. Information has been received at the State Department of the loss of the whale ships Arabella and America, of New Bedford; the Henry Thompson and Armada, of New London; the Mary Mitchell, of San Francisco, and the Sol Sollares, of Fall River.