The agreed statement presents the naked question whether, after the execution of a sealed instrument, a material blank can be filled by a third person, in the absence of the obligor, and without his express authority, under hand and seal. An immaterial blank, as of the date, or the name of the obligor, may be inserted. Such interlineations do not affect the obligation. It is valid without them. But, without the sum is inserted, the bond is of no validity. In the case at bar, the obvious intention of all the defendants was, that this bond should be filled up by some one, and that it should be used for the purposes to which it was applied. This state of facts presents strong reasons why the instrument should be sustained. It makes a case of great hardship if it cannot be sustained. Looking very much like adhering to form, at the expense of justice. What originated the distinction between sealed and unsealed instruments in this respect, ■ is a question that is not useful now to inquire into. There are many rules of established law for which, at this day, it would be difficult to assign a good reason, were the question presented for the first time whether they should be adopted or not, and yet, because they have been rules for centuries, have become known, and have been acted upon in all the varied transactions of business, no prudent jurist would be willing to see their authority shaken for light causes. Where the law is uncertain, no man knoweth when he is safe. And it is, therefore, generally better to adhere to well settled, long established and well understood rules of Saw, though some small inconvenience arise from them, until *517the supreme power of the State sees proper to change them. A legislative enactment may make any change in the common law that even convenience requires, and it is to be presumed that the change will be made whenever the Legislature become satisfied that a rule of the common law works public inconvenience. Courts of justice can scarcely ever anticipate the full effect of a change made by them. In the case before them, they may possibly be able to say, the departure from the law subserves the ends of justice. They may prove that it will operate well in future transactions, but how it may affect past transactions, what may be the extent of the mischief of its retrospective operation, is often more than would be even imagined. For these reasons, we-look to the law for a solution of this question — and we find the course of decision uniform, in this Court, in the Courts of our sister States, of the United States, and Great Britain. They all concur in holding that such a blank could not be filled as this was filled. There is not a case to be found that supports this bond. The researches of counsel have superseded the necessity of any quotation on our part for authority to condemn the practice.

Judgment fan' Defendant.