It is contended by the Government that that part of the law under immediate consideration, which provides that no person, for the same offense, shall be twice put in jeopardy, must be construed in view of the system of laws prevailing in the islands before the same were ceded to the United States, and that the purpose of Congress was to make effectual the jurisprudence of the islands as known and established before American occupation, and that the provision against double jeopardy must be read in the light of the understanding of that expression in the civil law, or rather the Spanish law as it was then in force.