This is the entire communication, no other subjects being touched upon; but the matter seems of so much importance and of so great national interest as to warrant the sapient Mr. Nelson in making it the basis of a special official despatch. Is this gentleman the envoy of the United States, or a commissioner appointed by some Bible or tract society to report on the “spread of Protestantism” in the neighboring republic, or does he unite the two characters in his own person? Does he receive the public money for puffing the Rev. H. Chauncey Reilly, and transmitting his diatribes and the effusions of a certain M. Altamirano for preservation in the archives of the nation? If so, it is time the public should know it. Mr. Nelson’s letter, however, explains an incident that occurred in Washington a few years since. It was this: the mission to Mexico was vacant, and it was applied for by a gentleman every way qualified for the post. He was thoroughly educated, knew the Spanish language well, and had served with high rank and marked distinction during the late war. He was appointed by the President, and his nomination by the Senate was urged by several influential citizens, including the then Secretary of State, the late Mr. Seward. The committee of the Senate refused to report his name favorably, and, in reply to the query of the writer what objection could be urged against the applicant, a leading senator replied that “he understood him to be a very violent (meaning practical) Catholic!” The policy of this gentleman, like that of many others at the national capital, was not to send a Catholic to a Catholic country, but one who would report on the “spread of Protestantism,” and doubtless, find materials for his despatches. Nor must we blame the government too severely for their injudicious sectarian appointments. Its views are but the reflex of popular opinion, and, as long as we tolerate bigotry and proscription in our popular elections, we must expect that those who are supposed to represent us will follow the bad example thus set them. The fault hitherto has been partly ours, and the remedy is in our own hands. This remedy consists in discountenancing all subsidized newspaper writers and demagogues whose abuse and slanders prevent good men from filling the national and state councils; in trampling under foot all party and religious prejudices, and invariably voting against those who would maintain them; and by supporting for offices, both at home and abroad, only those who will attend to the public business, and let sectarian missionaries and the “spread of Protestantism” alone. A LEGEND OF S. MARTIN. AFTER many strifes and battles, and after having been for years Administrator of Thrace, Asia, and Egypt, with Dacia and Macedonia, to which the dethroned and executed Emperor of the West, Gratian, had appointed him, Theodosius I., the Roman emperor, returned from Thessalonica, his former headquarters, to Constantinople.