Delivered in the House of Representatives, April 24, 1860. Mr. TOMPKINS said: Mr. Chairman : The charge is frequently made, that nothing but slavery occupies the attention of the National Legislature. That this charge is true to a great extent, that this subject is constantly kept before the country, and that there is constant excitement about it, is not the fault of the Republican party. In the first hour of the present session of Congress, it was thrust upon the House by a member of the slaver