From HAYTI we have the particulars of a conspiracy against the Emperor Soulouque, in which a number of officers of the Government were implicated. Many arrests and some executions have taken place in consequence. The attempt of the American Commissioner and the French and English Consuls to settle the controversy between the Haytians and Dominicans, is supposed to have been unsuccessful. The Government has declined to pay the claims of certain American merchants to which our Government has repeatedly called its attention. GREAT BRITAIN. The event of the month has been the opening of the Great Exhibition. As if to concentrate attention upon it, all other affairs of interest have been withdrawn from the stage. No little surprise and indignation were aroused by the announcement made on the 15th of April, that the Queen would open the Exhibition in person, but that the holders of tickets and exhibitors would be excluded from the ceremony. Those who had purchased tickets for the express purpose of being present at the opening, were naturally indignant at losing the most interesting part of the show. The press was unanimous in condemnation of the contemplated exclusion. It was denounced as an unworthy insinuation that the person of the Queen would not be secure in public; and as giving countenance to certain absurd rumors of a projected insurrection. The opposition was so general that the offensive announcement was withdrawn, and a new programme substituted, in accordance with which holders of season tickets were allowed to be present. The rush for these was so great, that the Commissioners immediately raised the price another guinea. The Queen proved a greater attraction than Jenny Lind had ever been. We can only glance at the opening ceremonies. Early in the morning the exhibitors took their places at their stands; and the spectators came trooping in. At half-past eleven the Commissioners, foreign and domestic, stationed themselves in front of a platform of state, under the arch of the transept. Upon the platform were the Archbishop of Canterbury, the Ministers and great Officers of State, the Embassadors and Ministers from foreign Powers, in full dress. At high noon, the royal cortège entered the Crystal Palace, the choir upraising the national anthem of "God save the Queen." Then came addresses to the Queen from the Commissioners and the foreign Embassadors, to which the Queen read answers handed to her by the Secretary of State; then followed a prayer pronounced by the Archbishop of Canterbury, and an anthem; a marching in procession along the nave; a return to the platform, and the announcement by the Queen that the Exhibition was opened, proclaimed to the thousands without by a flourish of trumpets and a royal salute from the park.