McKIM v. THOMMOH

to be called in. Therefore, the proofs and exhibits that have been
taken and brought in under the order of the 10th of May last, must,
upon the present occasion, be laid aside as altogether inadmissible.

Having thus disposed of the proffered auxiliaries of the plain-
tiffs, let us now take a review of those tendered by the defendant
Thompson. He insists, that a certain paper he has presented as a
supplemental answer, ought to be considered as an amended answer,
or that he ought now to be permitted to file a supplemental answer
as prayed by his petition.

It is with great difficulty permitted to a defendant to make any
alteration in his answer, even upon a mistake. And there is no
instance of its having been allowed for the purpose of retracting a
clear and well understood admission, (p) It should appear due to
general justice to permit the issue to be altered. The rule upon
this subject is, that the defendant must move to put in a supple-
mental answer, and accompany the motion with an affidavit, in
which he must swear, that when he put in the answer, he did not
know the circumstances upon which he applies, or any other cir-
cumstances upon which he ought to have stated the fact otherwise,
or that when he swore to his original answer, he meant to swear
in the sense in which he now desires to be at liberty to swear.(q)

The paper tendered as an amended answer, comes within no
part of this rule. It is silent as to the causes which occasioned
him to omit mentioning the new matter, therein contained, in his
original answer; nor does it say any thing of his not knowing of
the new circumstances therein disclosed. It, in fact, purports to
be a mere additional or amended answer, proposed to be put on
file with the leave of the court, without any previous affidavit,
attempting to account for the mistakes or omissions proposed to
be corrected or supplied. It must, therefore, be altogether rejected.

But this defendant has now filed his petition, on oath, in a formal
manner, praying for leave to file a supplemental answer. This
petition points out, with sufficient certainty, that which the petitioner
alleges was a mistake as to the time of receiving the money first
spoken of in his answer. But that part of the answer, which is
thus designated as erroneous, is too indefinite, and obscure to lay
the foundation of such an older as is asked for by the present
motion. It speaks of " considerable payments," without specifying
whether they were made in bills3 or cash, or what was the amount

(p) Pearce v. Grove, 3 Atk. 522.(q)) Livesey v. Wilson, 1 Ves. & Bea, 149.