mpany shall make it appear that its
agents exercised ordinary diligence, the presumption in all cases being
against the company, and which was construed by State courts as
permitting said presumption of evidence to be weighed against opposing
testimony and to prevail unless such testimony is found by a jury to be
preponderant.[789] On the other hand, a South Carolina statute which
raised a presumption of negligence against a railroad upon proof of
failure to give prescribed warning signals was sustained because the
presumption therein established gave rise merely to a temporary
inference which might be rebutted by contrary evidence and which is
thereafter to be excluded in determining proximate cause.[790]

Presumptions sustained as constitutionally tenable include those set out
in statutes providing that when distillery apparatus is found upon the
premises of an individual, such discovery shall be _prima facie_
evidence of actual knowledge of the presence of the same;[791] that the
flowing, release, or escape of natural gas into the air shall constitute
_prima facie_ evidence of prohibited waste,[792] and that prior
conviction of a felony shall be conclusive evidence of bad character
justifying refusal to issue a license to practice medicine.[793] Upheld,
consistently with the former, were two sections of the California alien
land law; one, which specified that the taking of title in the name of a
person eligible to hold land, where the consideration is furnished by
one ineligible to acquire agricultural land, shall raise a _prima facie_
presumption that the conveyance is made to evade the law;[794] and a
second, which cast upon a Japanese defendant the burden of proving
citizenship by birth after the State endeavored to prove that he
belonged to a race ineligible for naturalization.[795] In contrast with
the latter result, however, is a subsequent decision of the Court
holding unconstitutional another section of the same California law
providing that when an indictment alleges alienage and ineligibility to
United States citizenship of a defendant, the burden of proving
citizenship or eligibility thereto shall devolve upon the
defendant.[796] As a basis for distinguishing these last two decisions
the Court observed that while "the decisions are manifold that within
[the] limits" of fairness[797] and reason the burden of proof may be
shifted to the defendant even in criminal prosecutions, nevertheless, to
be justified,