delivered the. opinion of the, Court.

Plaintiff in error was convicted in the court below qf the offense of concealing a quantity of smoking opium after importation, with knowledge that it had been imported in violation of the Act of February 9, 1909, c. 100, 35 Stat. 614, as amended by the Act of January 17, 1914, c. 9, 38 Stat. 275. Sections 2 and 3 of the, act as amended are challenged as unconstitutional, on the ground- that they contravene the due process of law and the compulsory self-incrimination clauses of the Fifth Amendment of the federal Constitution.

Section 1 of the act prohibits the importation into the United States of opium in any form after April 1, 1909, except that opium and preparations and derivatives thereof, other than smoking opium or opium prepared for *182 smoking, may be imported for medicinal purposes only, under regulations, prescribed by the Secretary of the Treasury. Section 2 provides, among other things, that if any person shall conceal or "facilitate the concealment of such opium, etc., after importation, knowing the same to have-been imported contrary to law, the offender shall be subject to fine or imprisonment or both. It further provides that whenever the defendant on trial is shown to have, or to have had, possession of such opium, etc., “ such possession shall be deemed sufficient evidence to authorize conviction unless the defendant shall explain the possesion to the satisfaction of the jury.” Section 3 provides that. on and after July 1, 1913, “ all smoking opium or opium prepared for smoking found within the United States shall be presumed to have been imported after the first day of April, nineteen hundred and nine, and the burden of proof shall be on the claimant or the accused to rebut such presumption.”

The plaintiff in error, at the time of his arrest in August, 1923, was found in possession of and concealing a quantity of smoking opium. The lower court overruled a motion for an instructed verdict. of not guilty, and, after stating the foregoing statutory presumptions, charged the jury in substance that the burden of proof was on the accused to rebut such presumptions; and that it devolved upon him to explain that he was rightfully in possession of the smoking opium, — “ at least explain it to the satisfaction of the jury.” The court further charged that the defendant was presumed to be innocent until the government had satisfied the minds of the jurors of his guilt beyond a reasonable doubt; that the burden to adduce such proof of guilt beyond the existence of a reasonable doubt rested on the government at all times and throughout the trial; and that a conviction could not be had “ while a rational doubt remains in the minds of the jury.”

*183 The authority of Congress to prohibit the importation of opium in any form and, as a measure reasonably calculated to aid in the enforcement of the prohibition, to make its concealment with knowledge of its unlawful importation a criminal offence, is not open to doubt. Brolan v. United States, 236 U. S. 216; Steinfeldt v. United States, 219 Fed. 879. The question presented is whether Congress has power to enact the provisions in respect of the presumptions arising from the unexplained possession of such opium and from its presence in this country after the time fixed by the statute.

In Mobile, etc., R. R. v. Turnipseed, 219 U. S. 35, 42, 43, this Court, speaking through Mr. Justice Lurton, said:

“ The law of evidence is full of presumptions either of fact or law. The former are, of course, disputable, and the strength of any inference of one fact from proof of another depends upon the generality of the experience upon which it is founded. . . .

“ Legislation providing that proof of one fact shall constitute prima facie evidence of the main fact in issue is but to enact a rule of evidence, and quite within the general power of government. Statutes, National and state, dealing with such methods of proof in both civil and criminal cases abound, arid the decisions upholding them are numerous. . . .

“ That a legislative presumption of one fact from evidence of another may not constitute a denial of due process of law or a denial of the equal protection of the law it is only essential that there shall be some rational connection between the fact proved and the ultimate fact presumed, and that the inference of one fact from proof of another shall not be so unreasonable as to be. a purely arbitrary mandate. So, also, it must not, under guise of regulating the presentation of evidence, operate to preclude the party from the right to present his defense to the main fact thus presumed.”

*184 See also, Luria v. United States, 231 U. S. 9, 25; State v. Moriarty, 50 Conn. 415, 417; Commonwealth v. Williams, 6 Gray 1, 3; State v. Sheehan, 28 R. I. 160.

The legislative provisions .here assailed satisfy these requirements in respect of due process. They have been upheld against similar attacks, without exception so far as we are advised, by the lower federal courts. Charley Toy v. United States, 266 Fed. 326, 239; Gee Woe v. United States. 250 Fed. 428; Ng Choy Fong v. United States, 245 Fed. 305; United States v. Yee Fing, 222 Fed. 154; United States v. Ah Hung, 243 Fed. 762 764. We think it is not an illogical inference that opium, found in this country more than four years (in the present case, more than fourteen years) after its importation had been prohibited, was unlawfully imported. Nor do we think the further provision, that possession of such Opium in the absence of a satisfactory explanation shall create a presumption of guilt, is “ so unreasonable as to be a purgly arbitrary mandate.” By universal sentiment, and settled policy as evidenced by state and local legislation for more than half a century, opium is an illegitimate commodity, the use of which, except as a medicinal agent, is. rigidly condemned. Legitimate possession, unless for medicinal use, is so highly improbable that -to say to any person who.obtains the outlawed commodity, “since you are bound to know that it cannot be brought into this country at all, except under regulation for médicinal use, you must at your peril ascertain and be .prepared to show the facts and circumstances which rebut, or tend to rebut, the natural inference of unlawful importation, or your knowledge of it,” is not such an unreasonable requirement as to cause it to fall outside the constitutional power of Congress.

Every accused person, of course, enters upon his trial, clothed with the presumption of innocence. But that presumption may be overcome, not only by direct proof, but, in many cases, when the facts standing alone; are *185 not enough, by the additional weight of a countervailing legislative presumption. If the effect of the legislative act is to give to the facts from which the presumption is drawn an. artificial value to some extent, it is no more than happens in respect of a great variety of presumptions not resting upon statute. See Dunlop v. United States, 165 U. S. 486, 502-503; Wilson v. United States, 162 U. S. 613, 619. In the Wilson case the , accused, charged with murder, was found, soon after the homicide, in possession of property that had belonged to the dead man. This Court upheld a charge of the trial court to the effect that such possession required the accused to account for it, to show that as far as he was concerned the possession was innocent and honest, and that if not so accounted for it became “ the foundation for a presumption of guilt against the defendant.”

The point that the practical effect of the statute creating the presumption is to compel the accused person to be a witness against himself may be put aside with slight discussion. The statute compels nothing. It does no more than to make possession of the prohibited article prima facie evidence of guilt. It leaves the accused entirely free to testify or not as he chooses. If the accused happens to be the Only repository of the facts necessary,to negative the presumption arising from his possession, that is a misfortune which the statute under review does not create but which is inherent in the case. The same situation might present itself if there were no statutory presumption and a prima facie case of concealment with knowledge of unlawful importation were made by the evidence. The necessity of an explanation by the accused would.be quite as, compelling in that case as in this; but the constraint upon him to give testimony would arise there, as it arises-here, simply from the force of circumstances and not from, any form of compulsion forbidden by the Constitution.

Judgment affirmed.