The Herald this morning puts forth an ominous announcement :
it is to be hoped that it will prove to be only a little newspaper spice to sea- son the political dulness of the time-
" We have reason to believe that a very serious misunderstanding now exists between the British Government and the United States, arising on the one hand from the unwillingness of the American President to apologize for the detention of a British subject (M'Leod) on an unfounded charge, and on the other, from the alleged fact that vessels engaged in the slave-trade are noto- riously fitted out in American ports. Lord Aberdeen, as we learn, has written repeated and decided notes on both these subjects, without as yet receiving satisfactory answers; and, considering the fresh obligations imposed on this country by the new Anti-Slave treaty, it is much to be feared that something unpleasant may occur between both Governments. Our information on this subject is derived from a most authentic source."