ced the legislature to enact the
statute in the first place.[79] However, in Powell _v._
Pennsylvania,[80] decided the following year, the Court, being
confronted with a similar act involving oleomargarine, concerning which
it was unable to claim a like measure of common knowledge, fell back
upon the doctrine of presumed validity, and declaring that "it does not
appear upon the face of the statute, or from any of the facts of which
the Court must take judicial cognizance, that it infringes rights
secured by the fundamental law, * * *"[81] sustained the measure.

In contrast to the presumed validity rule under which the Court
ordinarily is not obliged to go beyond the record of evidence submitted
by the litigants in determining the validity of a statute, the judicial
notice principle, as developed in Mugler _v._ Kansas, carried the
inference that unless the Court, independently of the record, is able to
ascertain the existence of justifying facts accessible to it by the
rules governing judicial notice, it will be obliged to invalidate a
police power regulation as bearing no reasonable or adequate relation to
the purposes to be subserved by the latter; namely, health, morals, or
safety. For appraising State legislation affecting neither liberty nor
property, the Court found the rule of presumed validity quite
serviceable; but for invalidating legislation constituting governmental
interference in the field of economic relations, and, more particularly,
labor-management relations, the Court found the principle of judicial
notice more advantageous. This advantage was enhanced by the disposition
of the Court, in litigation embracing the latter type of legislation, to
shift the burden of proof from the litigant charging unconstitutionality
to the State seeking enforcement. To the latter was transferred the task
of demonstrating that a statute interfering with the natural right of
liberty or property was in fact "authorized" by the Constitution and not
merely that the latter did not expressly prohibit enactment of the same.

Liberty of Contract--Labor Relations

Although occasionally acknowledging in abstract terms that freedom of
contract is not absolute but is subject to restraint by the State in
the exercise of its police powers, the Court, in conformity with the
aforementioned theories of economics and evolution, was in fact
committed to the principle that freedom of contract is the general rule
and that legislative aut