Alexandria Gazette & Daily Advertiser

Boston, July 8.

On Thursday last the brig Rebecca, capt. Snow, arrived from the Cape de Verd Islands, and brought as passengers Midshipman James K. Vallette, and in his charge eighteen persons as prisoners who were taken by the U.S. sloop of war Cyane, from the schooners Plattsburgh, Science and Endymion.

Yesterday the prisoners were brought before the hon. Judge Davis, to be examined on the charge of being concerned in the slave trade. Among them were Joseph L. Smith, reputed master of the Plattsburgh, and Adolphus Lacoste, a Frenchman, but some time resident in the United States, reputed master of the Science. There were other persons, said to be Spaniards, who were nominally masters of these vessels. The prisoners appeared to be principally foreigners, of almost all nations and shades of complexion. Two of them were negroes, one of whom said he was born at sea; one called himself a Dane, one a Prussian; several appeared to be natives of the East and West Indies.

The vessels to which these men belonged were seized by the commander of the Cyane, under instructions of the government, in pursuance of the act of 1819, by which the president is authorised to employ the armed ships of the United States, to take and bring in vessels of the United States, that shall have taken any slaves, or that shall be intended to take any, and to bring in all persons on board such vessels, that they may be proceeded against according to law. By the law of April 20, 1818, the fitting out and being concerned in vessels for the purpose of being employed in the slave trade is prohibited, under penalty of from 1000 to 5000 dollars and imprisonment; and all persons concerned in transporting persons intended to be sold as slaves, are liable to the penalty of from 1000 to 5000 dollars, and imprisonment.

The master of the Endymion was Andrews, a midshipman in the United States Navy, on furlough, belonging to Baltimore. Andrews has been sent into New York. Southcomb, one of the prisoners, stated on his examination, that he was born in Virginia, that he shipped on board the Endymion at Matanzas, at 40 dollars per month. The mate, named Anderson, and five of the crew, were Americans. Among them were James Turner of R. Island, McKoy of Philadelphia, and Butler of New-York.

It was suggested that the boarding officer of all these vessels, and the principal testimony against them were now in New-York. The Hon. Judge, however, seemed to be of opinion, that the evidence against the prisoners was such as to require of him to hold them to bail. But at the request of the counsel for two of them, J. T. Austin, Esq. who had had no opportunity to consult with them on the grounds of their defence, he deferred a definite order respecting them, and adjourned the further examination to this day at 11 o'clock, to which time the marshal was ordered to keep the prisoners in custody.

We do not deem it proper to publish the details of the examination. But we beg leave to make one remark. The seamen as far as they were examined, professed ignorance of the objects of the voyages for which they shipped, and seemed to consider that it was no part of their business to know whether they were engaged in a lawful or an unlawful trade. John Thomas, a black, said that he did not know or inquire any thing about the object of the voyage, he shipped only as a seaman before the mast, and 'studied only what wages he was to have.' It is extremely important that seamen should be better instructed. They ought to know that they are all individually responsible for the enterprises they engage in—and that if these enterprises are unlawful, they are not only liable to suffer the penalties of a violation of the law, but that they are much less likely to escape detection and punishment than their employers.