3o6 HARVARD LAW REVIEW,
The doctrine of the case seems to be that a State police law which obstructs interstate commerce to a greater extent than is strictly necessary for the accomplishment of the purpose of the law, is an unconstitutional regulation of commerce. At the argu- ment, counsel were compelled to admit that Texas cattle kept for a certain time away from their native range — for example, wintered in Iowa or Nebraska — would not impart the disease, but would be excluded by the law.^ The principle of the case applies to quar- antine laws as well. The Missouri law seems indistinguishable from a quarantine law, save in the scope of its prohibitory pro- visions. Instead of only for a few days, the dangerous property was forbidden entrance during eight months ; instead of only a few ports, a large territory was included in the prohibition. To that extent the temporary and local character of quarantine regu- lations was lost. As the court points out, the law provided for no examination to determine what cattle were diseased. A quaran- tine to be effectual must exclude all persons or property danger- ously liable to impart the disease. Texas cattle, not themselves betraying any symptom of disease, it is said, can impart it. Moreover, an examination is material only because it diminishes to a minimum the prohibition of intercourse with the region quar- antined against. This reasoning of the court applies with equal force to State port regulations, pilotage, inspection, and quar- antine laws. The line must be drawn somewhere, and it is con- ceived that the rule in the Railroad Company v, Husen draws it just where the Constitution makers intended, and indeed at the only place possible in the nature of the subject, giving to the States all necessary power, but protecting foreign and interstate commerce from unnecessary interference. The conclusion we have reached from this line of cases is that a quarantine law whose provisions burden foreign or interstate commerce to an extent greater than the protection of health requires, is an unconstitutional regulation of commerce by the State.
The rule in Railroad Company v, Husen would seem to apply with equal force to a quarantine declared, it may be on account of a popular panic, under circumstances in which it was " so clear and palpable as to be perceptible to any mind at first blush " that there was no reason to apprehend danger from the place quar- antined against. It may fairly be said to be absolutely necessary 1 Note by counsel in 6 Cent. Law Jour. 217.