delivered the opinion of the court.

It appears, from the record in this case, that it was originally begun by an information by the attorney-general, upon the relation of John Thompson, a person alleged to be of weak mind, and the said John Thompson himself, to avoid a deed to the said defendants which he and his wife sealed and delivered and acknowledged in due form; but which it was alleged he, by reason of his infirmity of mind, was incapacitated from executing so as to be bound by it. The solicitor for the complainant discovering, after the appearance of the defendants, that the proceeding ought to have been by bill and by a next friend, applied to the court for leave to amend the proceeding by making what was an information technically a bill, and also by substituting Clara Thompson as a next friend of the said John Thompson, instead of the attorney-general, acting ex relatione. This application *230 was granted, and the case proceeded to hearing upon proofs before the chancellor, and the decree against the respondents from which this appeal was taken.

There is but a single cause of appeal prosecuted by the appellants, the respondents below, and that is that the amendment ought not to have been allowed. The question, therefore, made in the argument, was upon the power of the chancellor to allow such an amendment; the appellants contending that there was no power in the chancellor to allow the amendment made, for the reason that a total change of parties complainant was made, and the information was turned into a bill. The answer made was, that John Thompson, the non compos was an original party, and so remained since the amendment, though now acting through a next friend, instead of relator to the attorney-general; and that informations and bills were, in all essential particulars, the same; and the change in this case was a proper one, and not unusual in chancery cases.

The subject of the appeal was thoroughly discussed by the learned counsel on both sides, with the aid of authorities— the respondent in this court contending also that the act of the chancellor, in allowing the amendment mentioned, was not subject to be reviewed in this court; and upon consideration of the subject we are of opinion that the objection to review of the leave granted to amend, is well taken ; and that is all we have need now to decide.

The power to grant amendments to proceedings in it, inheres in every judicial tribunal; and will always be exercised in the interest of justice. It is, however, a discretionary power, and not ex debito justitice ; though, practically, courts treat it almost as such. But being discretionary, it is not reviewable elsewhere, unless there be usage to that effect, or some positive provision of law. It was not made to appear in the course of the argument by the learned counsel for the appellant, that there was any such usage, nor do. we know of any ; in fact, he seemed to treat the act of the chancellor as in the light of an interlocutory decree, and we suppose that is the view he really took of it. *231 The 7th section of article 2 of the constitution of this State provides (speaking of this court) as follows:

“ The Court of Errors and Appeals shall have jurisdiction to issue writs of error to the Superior Court, and to receive appeals from the Court of Chancery, and to determine finally all matters in error in the judgments and proceedings of said Superior Court, and all matters of appeal in the interlocutory or final decrees and proceedings in chancery.”

We understand this language to mean that there shall be an appeal from chancery in the case of interlocutory decrees and final decrees, and the proceedings belonging to or connected with each; and not to all proceedings whatever in the course of the suit. If the leave given to amend is an interlocutory decree, then an appeal from it or from the final decree founded upon what grew out of it, would undoubtedly lie; because it comes within the provision of the 7th section of the 6th article of the constitution above quoted. What is an interlocutory decree, is stared in the first volume of Harrison’s Chancery at pp. in this language:

“A decree is interlocutory, when it happens that some material circumstance, or fact, necessary to be made known to the court, is either not stated in the pleading, or so imperfectly ascertained by them, that the court, by reason of that defect, is unable to determine finally between the parties; and therefore a reference, or an inquiry before, a master, on the trial of the facts before a jury becomes necessary to have the doubts occasioned by that defect removed; the court, in the meantime suspends its final judgment, until by the master’s report, or the verdict of a jury, it is enabled to decide finally.”

From this citation, it cannot be maintained that leave given to amend the pleadings in the suit is in any sense an interlocutory decree, but is an order made in the usual course of the practice of the court; and, therefore, not reviewable by another tribunal. If re-examination could be had, in another court, of the grounds or propriety of the exercise of discretion, there would virtually be no independent discretion at all; and courts of review would be overwhelmed with cases of mere practice. No writ of error *232 lies from ,the action of the Superior Court in granting or refusing an amendment except, when the permission, or refusal, to make such amendment, is during the trial of the cause: Vide § 17, of chap, xii., of the Revised Code, p. 692. For this exception to the general law on the subject of discretionary proceedings, there may be a good reason assigned, to wit: the want of time for consideration when a trial is progressing. It is, however, the only exception to the rule, that the discretion of a court, in a matter of practice in it, cannot be interfered with.

The opinion of this court therefore is, that the decree of the chancellor in this case be affirmed; and a decree is ordered to be drawn accordingly.