Digest. competent witness against her 3. Right of defendant in an indict- 4. On the hearing of an issue as to whether an excavation in a city street was properly refilled, an expert witness who had heard the evidence as to such refilling, was asked and allowed to answer the following question: "How would you fill such an excavation?" Held, that while it was proper for the witness to state what would have been a proper manner of refilling the excavation, it was an error to allow him to testify how he would have refilled it. (Ayres agt. Water Commissioners, 22 Hun, 297.) 5. One who has personal knowledge of the facts of a case may give his opinion as an expert, but he cannot give such opinion when he possesses no knowledge of the facts except such as he derives from having heard the testimony of other witnesses. (Id.) 6. Where a witness, offered as an expert, has not personal knowl edge as to the facts, he can only testify in answer to hypothetical questions which assume the existence of the facts claimed by the party conducting the examination to have been proved. (Id.) The fact that one issue existed in the case, which might have been decided in favor of the successful party, does not justify the appelfate court in disregarding errors in the admission of testimony bearing upon a different issue, and holding that the evidence so admitted was harmless. (Id.) WRIT OF PROHIBITION. 1. The statute permitting summary proceedings founded upon an execution sale, affords the vendee of real estate a summary remedy against the judgment debtor in possession. It was not intended to extend the remedy to those in possession under the judgment debtor or his legal representatives. (The People ex rel. Higgins, agt. McAdam, ante, 139.) 2. Where the admitted facts take the litigation without the operation of the statute and, consequently, without the jurisdiction of the court, a writ of prohibition is the proper remedy (Affirming S. C., 59 How., 442). (Id.) |