]; unless it be such a custom as the
corporation is itself interested in, as a right of taking toll, &c,
for then the law permits them not to certify on their own behalf[f].

[Footnote e: Cro. Car. 516.]

[Footnote f: Hob. 85.]

WHEN a custom is actually proved to exist, the next enquiry is into
the legality of it; for if it is not a good custom it ought to be no
longer used. "_Malus usus abolendus est_" is an established maxim of
the law[g]. To make a particular custom good, the following are
necessary requisites.

[Footnote g: Litt. Sec. 212. 4 Inst. 274.]

1. THAT it have been used so long, that the memory of man runneth not
to the contrary. So that if any one can shew the beginning of it, it
is no good custom. For which reason no custom can prevail against an
express act of parliament; since the statute itself is a proof of a
time when such a custom did not exist[h].

[Footnote h: Co. Litt. 113 _b._]

2. IT must have been _continued_. Any interruption would cause a
temporary ceasing: the revival gives it a new beginning, which will be
within time of memory, and thereupon the custom will be void. But this
must be understood with regard to an interruption of the _right_; for
an interruption of the _possession_ only, for ten or twenty years,
will not destroy the custom[i]. As if I have a right of way by custom
over another's field, the custom is not destroyed, though I do not
pass over it for ten years; it only becomes more difficult to prove:
but if the _right_ be any how discontinued for a day, the custom is
quite at an end.

[Footnote i: Co. Litt. 114 _b._]

3. IT must have been _peaceable_, and acquiesced in; not subject to
contention and dispute[k]. For as customs owe their original to common
consent, their being immemorially disputed either at law or otherwise
is a proof that such consent was wanting.

[Footnote k: Co. Litt. 114.]

4. CUSTOMS must be _reasonable_[l]; or rather, taken negatively, they
must not be unreasonable. Which is not always, as sir Edward Coke
says[m], to be understood of every unlearned man's reason, but of
artificial and legal reason, warranted by authority of law. Upon which
account a custom may be good, though the particular reason of it
cannot be assigned; for it sufficeth, if no good legal reason can be
assigned against it. Thus a custom in a parish, that no man shall put
his beasts into the common till the third of october, would be good;
and yet it would be hard to she