Opinion by

In a proceeding to assess damages for lands appropriated for railroad purposes under the right of eminent domain, a witness produced by the landowner, was asked on preliminary cross-examination if his estimate of what the property was worth at the time of the entry, was based upon what it would bring if it had been laid out in building lots and all the lots had been sold at what the witness thought they were worth. The witness having answered in the affirmative, objection was made that he was not qualified to express an opinion, because his method of estimating the market value of the whole tract was improper and not in accordance with the rule of law governing such cases. The court admitted the testimony and this ruling is the basis of the only assignment of error. While it is *634proper to take into consideration the use to which the land is best adapted, it is improper to determine the value of the whole tract by computing the number of lots it could be divided into, what each lot was worth, and the value of the whole tract estimated on this basis. This is not a proper method of arriving at the value of the whole tract as has been repeatedly ruled by this court: Penna. Schuylkill Valley Railroad Company v. Cleary, 125 Pa. 442; Gorgas v. Railroad Company, 215 Pa. 501. Nor was this error corrected by the learned trial judge in his charge to the jury. Where evidence has been improperly admitted which tends to prejudice the minds of the jurors, the error is not cured by an instruction in the charge to disregard it or to withdraw it from their consideration: Delaware & Hudson Canal Co. v. Barnes, 31 Pa. 193; Penna. Railroad Co. v. Butler, 57 Pa. 335; Huntingdon, etc., Railroad & Coal Co. v. Decker, 82 Pa. 119; Erie, etc., Railroad Co. v. Smith, 125 Pa. 259.

Assignment of error sustained and a venire facias de novo awarded.