This, no doubt, correctly states the effect of the provision. When
it appears that, but for a particular promise or threat made by a
person in authority, the prisoner's confession would be voluntary, it
becomes necessary for the Judge at the trial to decide whether the
promise or threat in question was really calculated, that is, really
likely, to cause an untrue admission of guilt to be made. But a
promise of advantage and a threat of harm are not the only matters
which may deprive a statement of its voluntary character. For
instance, a confession which is extracted by violence or force, or
some other form of actual coercion is clearly involuntary, and, there-
fore, cannot be received in evidence. The enactment does not relate
to such cases. The position is well stated by Brandeis J. in delivering
the judgment of the Supreme Court of the United States in Wan
v. United States (2) : - The requisite of voluntariness is not satisfied
by establishing merely that the confession was not induced by a
promise or a threat. A confession is voluntary in law if, and only
if, it was in fact voluntarily made. A confession may have been
given voluntarily, although it was made to police officers, while in
custody, and in answer to an examination conducted by them.
But a confession obtained by compulsion must be excluded whatever
may have been the character of the compulsion, and whether the
compulsion was applied in a judicial proceeding or otherwise." The
notes to this case (3) give numerous examples where the compulsion
alleged takes the form of prolonged and sustained pressure by police
officers upon a prisoner in their hands, until, through mental and
physical exhaustion, to which want of sleep and food sometimes
contributes, he consents, in order to obtain relief, to make a confession
of the crime. If it is alleged that the confession is the outcome of