402 PRICE v. TYSON.—3 BLAND.

such matters involved in the controversy to be determined by the
suit at common law, in relation to which dispute alone thej were
interrogated by the plaintiff. This copy of the account from the
Orphans' Court must therefore be expunged from this case.

The plaintiff has also objected to what the defendant Mary has
said in relation to the freight; because what she states could, at
most, amount only to a verbal agreement, and the contract of the
parties was in writing.

This allegation made by the defendant Mary, in the joint and
several answer of these defendants, is evidently introduced as an
avoidance of so much of the plaintiff's claim; and therefore, could
be of no weight on any prayer for relief here; unless sustained by
proof. And if offered to be so established, the question would
then arise, whether such proof should not be rejected so far as it
was attempted to be relied on as giving an interpretation to a
written contract; or whether it would not be admitted upon the
ground, not of construing, but as an addition to, or alteration of
a written agreement.

If the defendant Mary were offered as a witness, to prove the
facts she states, it might be objected, that she was incompetent;
because of having been, at the time she obtained a knowledge of
the facts of which she speaks, the wife of the party as to whose
contract she testifies; as husband and wife are incompetent wit-
nesses for or against each other, as to all matters occurring during
the marriage, as well after as during the coverture. Nelius v.
Brickell, 1 Hayirood's Rep. 19; Doker v. Hosler, 21 Com. Law Rep.
416. If, however, * this was a bill for relief here, and this
406 case was set down for hearing on bill and answer, then this
allegation, in the answer of the defendant Mary, would be taken
for true, although she might be deemed incompetent to testify to
the fact as a witness. Lenox v. Prout, 3 Wheat. 527. But as to
the relevancy, legality, and competency of any testimony brought
out by a bill of discovery, it does not belong to this Court to
decide; because such questions can only be determined, with pro-
priety, by the Court of common law for whose use the discovery
has been required. Bishop of London v, Eytche, 1 Bro. C. C. 98;
Hindman v. Taylor, 2 Bro. C. C. 8.

It is a general rule, that on a bill of discovery the plaintiff must
pay to the defendant all his costs in this Court: and that too, in-
cluding all expenses incurred by the defendant in resisting motions
made in the case by the plaintiff. And the defendant's right to
make his demand, accrues as soon as he has answered, allowing
to the plaintiff a reasonable time to look into the sufficiency of the
answer. But it has been thought that this rule is too general;
that it ought, at least, to be so modified, so that the plaintiff should
not be bound to pay costs where, upon demand, the defendant had
refused voluntarily to make the requisite disclosures, so as to com-