Opinion of the Court. The statute of Minnesota upon the validity of which the decision of the case depends is as follows: Laws of 1889, c. 8, P. 51. "An act for the protection of the public health by providing for inspection, before slaughter, of cattle, sheep and swine designed for slaughter for human food. "SECTION 1. The sale of any fresh beef, veal, mutton, lamb or pork for human food in this State, except as hereinafter provided, is hereby prohibited. "SEC. 2. It shall be the duty of the several local boards of health of the several cities, villages, boroughs and townships within this State to appoint one or more inspectors of cattle, sheep and swine, for said city, village, borough or township, who shall hold their offices for one year, and until their successors are appointed and qualified, and whose authority and jurisdiction shall be territorially coëxtensive with the board. so appointing them; and said several boards shall regulate the form of certificate to be issued by such inspectors and the fees to be paid them by the person applying for such inspection, which fees shall be no greater than are actually necessary to defray the costs of the inspection provided for in section three of this act. "SEC. 3. It shall be the duty of the inspectors appointed hereunder to inspect all cattle, sheep and swine slaughtered for human food within their respective jurisdictions within twenty-four hours before the slaughter of the same, and if found healthy and in suitable condition to be slaughtered for human food, to give to the applicant a certificate in writing to that effect. If found unfit for food by reason of infectious disease, such inspectors shall order the immediate removal and destruction of such diseased animals, and no liability for damages shall accrue by reason of such action.` "SEC. 4. Any person who shall sell, expose or offer for sale for human food in this State, any fresh beef, real, mutton, lamb or pork whatsoever, which has not been taken from an animal inspected and certified before slaughter, by the proper local inspector appointed hereunder, shall be deemed guilty of Opinion of the Court. a misdemeanor, and upon conviction thereof shall be punished by a fine of not more than one hundred dollars, or by imprisonment not exceeding three months for each offence. "SEC. 5. Each and every certificate made by inspectors under the provisions of this act shall contain a statement to the effect that the animal or animals inspected, describing them as to kind and sex, were, at the date of such inspection, free from all indication of disease, apparently in good health, and in fit condition, when inspected, to be slaughtered for human food; a duplicate of which certificate shall be preserved in the office of the inspector. "SEC. 6. Any inspector making a false certificate shall be liable to a fine of not less than ten dollars nor more than fifty dollars for each animal falsely certified to be fit for human food under the provisions of this act. "SEC. 7. This act shall take effect and be in force from and after its passage." The presumption that this statute was enacted, in good faith, for the purpose expressed in the title, namely, to protect the health of the people of Minnesota, cannot control the final determination of the question whether it is not repugnant to the Constitution of the United States. There may be no purpose upon the part of a legislature to violate the provisions of that instrument, and yet a statute enacted by it, under the forms of law, may, by its necessary operation, be destructive of rights granted or secured by the Constitution. In such cases, the courts must sustain the supreme law of the land by declaring the statute unconstitutional and void. This principle of constitutional interpretation has been often announced by this court. In Ilenderson &c. v. New York &c., 92 U. S. 259, 268, where a statute of New York imposing burdensome and almost impossible conditions on the landing of passengers from vessels employed in foreign commerce, was held to be unconstitutional and void as a regulation of such commerce, the court said that "in whatever language a statute may be framed, its purpose must be determined by its natural and reasonable effect." In People v. Compagnie Générale Transatlantique, 107 U. S. 59, 63, where the question was as to the Opinion of the Court. validity of a statute of the same State, which was attempted to be supported as an inspection law authorized by section 10 of article 1 of the Constitution, and was so designated in its title, it was said: "A State cannot make a law designed to raise money to support paupers, to detect or prevent crime, to guard against disease and to cure the sick, an inspection law, within the constitutional meaning of that word, by calling it so in the title." So, in Soon Hing v. Crowley, 113 U. S. 703, 10: " "The rule is general, with reference to the enactments of all legislative bodies, that the courts cannot inquire into the motives of the legislators in passing them, except as they may be disclosed on the face of the acts, or inferrible from their operation, considered with reference to the condition of the country and existing legislation. The motives of the legislators, considered as the purposes they had in view, will always be presumed to be to accomplish that which follows as the natural and reasonable effect of their enactments." In Mugler v. Kansas, 123 U. S. 623, 661, the court, after observing that every possible presumption is to be indulged in favor of the validity of a statute, said that the judiciary must obey the Constitution rather than the law making department of the government, and must, upon its own responsibility, determine whether, in any particular case, the limits of the Constitution have been passed. It was added: "If, therefore, a statute purporting to have been enacted to protect the public health, the public morals or the public safety, has no real or substantial relation to those objects, or is a palpable invasion of rights secured by the fundamental law, it is the duty of the courts to so adjudge, and thereby give effect to the Constitution." Upon the authority of those cases, and others that could be cited, it is our duty to inquire, in respect to the statute before us, not only whether there is a real or substantial relation between its avowed objects and the means devised for attaining those objects, but whether by its necessary or natural operation it impairs or destroys rights secured by the Constitution of the United States. Underlying the entire argument in behalf of the State is the proposition, that it is impossible to tell, by an inspection of Opinion of the Court. fresh beef, veal, mutton, lamb or pork, designed for human food, whether or not it came from animals that were diseased when slaughtered; that inspection on the hoof, within a very short time before animals are slaughtered, is the only mode by which their condition can be ascertained with certainty. And it is insisted, with great confidence, that of this fact the court must take judicial notice. If a fact, alleged to exist, and upon which the rights of parties depend, is within common experience and knowledge, it is one of which the courts will take judicial notice. Brown v. Piper, 91 U. S. 37, 42; Phillips v. Detroit, 111 U. S. 604, 606. But we cannot assent to the suggestion that the fact alleged in this case to exist is of that class. It may be the opinion of some that the presence of disease in animals, at the time of their being slaughtered, cannot be determined by inspection of the meat taken from them; but we are not aware that such is the view universally, or even generally, entertained. But if, as alleged, the inspection of fresh beef, veal, mutton, lamb or pork will not necessarily show whether the animal from which it was taken was diseased when slaughtered, it would not follow that a statute like the one before us is within the constitutional power of the State to enact. On the contrary, the enactment of a similar statute by each one of the States composing the Union would result in the destruction of commerce among the several States, so far as such commerce is involved in the transportation from one part of the country to another of animal meats designed for human food, and entirely free from disease. A careful examination of the Minnesota act will place this construction of it beyond question. The first section prohibits the sale of any fresh beef, veal, mutton, lamb or pork for human food, except as provided in that act. The second and third sections provide that all cattle, sheep and swine to be slaughtered for human food within the respective jurisdictions of the inspectors, shall be inspected by the proper local inspector appointed in Minnesota, within twenty-four hours before the animals are slaughtered, and that a certificate shall be made by such inspector, showing (if such be the fact) that the animals, when slaughtered, were VOL. CXXXVI-21 Opinion of the Court. found healthy and in suitable condition to be slaughtered for human food. The fourth section makes it a misdemeanor, punishable by fine or imprisonment, for any one to sell, expose or offer for sale, for human food, in the State, any fresh beef, veal, mutton, lamb or pork, not taken from an animal inspected and "certified before slaughter, by the proper local inspector" appointed under that act. As the inspection must take place within the twenty-four hours immediately before the slaughtering, the act, by its necessary operation, excludes from the Minnesota market, practically, all fresh beef, veal, mutton, lamb or pork-in whatever form, and although entirely sound, healthy, and fit for human food — taken from animals slaughtered in other States; and directly tends to restrict the slaughtering of animals, whose meat is to be sold in Minnesota for human food, to those engaged in such business in that. State. This must be so, because the time, expense and labor of sending animals from points outside of Minnesota to points in that State to be there inspected, and bringing them back, after inspection, to be slaughtered at the place from which they were sent the slaughtering to take place within twentyfour hours after inspection, else the certificate of inspection becomes of no value will be so great as to amount to an absolute prohibition upon sales, in Minnesota, of meat from animals not slaughtered within its limits. When to this is added the fact that the statute, by its necessary operation, prohibits the sale, in the State, of fresh beef, veal, mutton, lamb or pork, from animals that may have been inspected carefully and thoroughly in the State where they were slaughtered, and before they were slaughtered, no doubt can remain as to its effect upon commerce among the several States. It will not do to say-certainly no judicial tribunal can, with propriety, assume that the people of Minnesota may not, with due regard to their health, rely upon inspections in other States of animals there slaughtered for purposes of human food. If the object of the statute had been to deny altogether to the citizens of other States the privilege of selling, within the limits of Minnesota, for human food, any fresh beef, veal, mutton, lamb or pork, from animals slaugh |