Odger's English Common Law

88 CUSTOMS.
a binding rule within that trade or market, governing all
transactions to which it is applicable, unless it be expressly-
excluded by the parties. 1
It is not enough to prove that
such a practice has been adopted in many instances. It
must be shown to be the recognised and established rule,
which would be followed in cases of dispute. And then it will
bind not only those who are members of the particular trade
or who regularly attend the particular market, but also
any one who deals with those traders or in that market,
whether personally or by an agent, and whether he knows of
the custom or not, unless he expressly excludes it. 2
A trade custom will not be valid if it is contrary to the
express provisions of a statute or to the general policy of our
law ; as, for instance, if it disregards section 1 of the statute
known as Leeman's Act, 3 relating to the sale of bank shares. 4
A trade custom may, however, negative or vary any incident
attached by law to a contract, which the parties themselves
might have agreed to negative or vary. 5 Thus a trade custom
may render a third person liable on a contract, who would not
be liable under the ordinary law of the land. 6
Again, a trade
custom will not be valid if it destroys the real nature of the
contract into which the parties intended to enter, e.g., if it
converts a broker into a principal. 7
Lastly, it must be a
reasonable custom. If, however, the parties have expressly
agreed to incorporate a particular usage into their contract, it
is immaterial whether the usage is reasonable or not. 8 And
where a party knows that a custom prevails in a particular
market and yet chooses to deal there without expressly
excluding it, it will be very difficult for him subsequently to
contend that the custom is unreasonable.
i Per Jessel, M. E., in Nelson v. Dahl (1879), 12 Ch. D. at p. 576. A custom
will be excluded if the express terms of a written agreement between the parties
are inconsistent with it : Yates v. Pym (1816), 6 Taunt. 446.
2 Buckle v. Kemp (1867), L. E. 2 Ex. 125 ; Steamship Co. " Norden " v.
Dempsey (1876), 1 C. P. D. 662.
3 30 Vict. c. 29.
4 perry T . Barnett (1885), 15 Q. B. D. 388.
5 Sale of Goods Act, 1893 (56 & 57 Vict. c. 71), s. 55.
6 Humfrey v. Dale (1858), E. B. & E. 1004 ; Hutchinson v. Tatham (1873),
L. E. 8 C. P. 482 ; Pike v. Ongley (1887), 18 Q. B. D. 708.
' Robinson v. Mollett (1875), L. E. 7 H. L. 802.
8 Stewart v. West India SS. Co. (1873), L. E. 8 Q. B. 68, 362.