168 SALMON v. CLAGETT.—3 BLAND.

the defendant who has omitted or failed, by a demurrer, or plea,
to protect himself from making the discovery required by the bill,
shall, in any or what case, be allowed to do so by means of this
defence of a negation or matter in avoidance relied upon only by
way of answer. Consequently, the question now to be decided is,
whether this new use can, before the hearing, be made of this an-
cient mode of defence.

Where the bill sets forth various facts as to the constituent parts
of that case, which entitles the plaintiff to the relief he asks, it is
obvious that if the defendant, by plea, denies and invalidates any
material one of them, he breaks up the plaintiff's whole case, and
destroys his right to recover. Thus, if the plaintiff' avers his right
to a share in a certain trade as a partner; and, as such, calls for a
discovery and account. The fact of his being a partner is an es-
sentially constituent part of his case; it is the first or principal
* point to be tried; and if that be denied, and shewn to be
150 untrue, his whole case is broken up, his right destroyed;
and therefore, he cannot have the discovery and account he calls
for, A plea which denies the fact of partnership, in such case, is
called a negative plea; and it will protect the defendant from the
discovery or account; the right to call for which having been
founded upon that which is denied.

Upon a like ground, where a defendant, in his answer, positively
denies the fact of partnership, his answer, ir is said, must be
deemed sufficient; and consequently, that he cannot be compelled
to go on and discover and account as required by the bill. This
denial in the answer, it is obvious, m this respect, performs the
office of a negative plea. It is one of the alleged exceptions to
the general rule, that a defendant who submits to answer, shall
answer fully as the bill requires. This, and all similar negations
in answers may be called negative exceptions.

Where a defendant, admitting all the facts in the bill to be true,
advances and affirms other facts not mentioned in the bill, in the
shape of a plea, as an avoidance and bar of the whole claim of the
plaintiff; such a plea affords to the defendant a protection from the
discovery sought by the bill. As where the plaintiff sets out his
right to an estate, and prays a discovery of some particulars re-
specting the title, and the defendant, by plea, avers, that he is a
bonafide purchaser for a valuable consideration without notice, he
will be protected by such plea from the required discovery. In
like manner, if the defendant, by his answer, avers, that he is such
a purchaser; it is said, that such matter, so alleged, in his answer,
must be deemed a sufficient answer; and allowed to protect him
from the discovery called for. This is another of the alleged ex-
ceptions to the general rule. It is evidently lounded on an aver-
ment of a new fact, in avoidance, which might have been made
the subject of a plea; and gives a protection from discovery in like