This sentence is distinguishable from those cited from the French courts in this: that there positive prohibitions existed against slavery, and the right to freedom was conferred on the immigrant slave by positive law; whereas here the consequences of slavery merely--that is, the public policy--were found to be contrary to the law of slavery. The case of the slave Grace, (2 Hagg.,) with four others, came before Lord Stowell in 1827, by appeals from the West India vice admiralty courts. They were cases of slaves who had returned to those islands, after a residence in Great Britain, and where the claim to freedom was first presented in the colonial forum. The learned judge in that case said: "This suit fails in its foundation. She (Grace) was not a free person; no injury is done her by her continuance in slavery, and she has no pretensions to any other station than that which was enjoyed by every slave of a family. If she depends upon such freedom conveyed by a mere residence in England, she complains of a violation of right which she possessed no longer than whilst she resided in England, but which totally expired when that residence ceased, and she was imported into Antigua." The decision of Lord Mansfield was, "that so high an act of dominion" as the master exercises over his slave, in sending him abroad for sale, could not be exercised in England under the American laws, and contrary to the spirit of their own. The decision of Lord Stowell is, that the authority of the English laws terminated when the slave departed from England. That the laws of England were not imported into Antigua, with the slave, upon her return, and that the colonial forum had no warrant for applying a foreign code to dissolve relations which had existed between persons belonging to that island, and which were legal according to its own system. There is no distinguishable difference between the case before us and that determined in the admiralty of Great Britain. The complaint here, in my opinion, amounts to this: that the judicial tribunals of Missouri have not denounced as odious the Constitution and laws under which they are organized, and have not superseded them on their own private authority, for the purpose of applying the laws of Illinois, or those passed by Congress for Minnesota, in their stead. The eighth section of the act of Congress of the 6th of March, 1820, (3 Statutes at Large, 545,) entitled, "An act to authorize the people of Missouri to form a State Government," &c., &c., is referred to, as affording the authority to this court to pronounce the sentence which the Supreme Court of Missouri felt themselves constrained to refuse. That section of the act prohibits slavery in the district of country west of the Mississippi, north of thirty-six degrees thirty minutes north latitude, which belonged to the ancient province of Louisiana, not included in Missouri.