In this case, which was assumpsit for selling an unsound horse, it was laid down and admitted by the bar and bench, that if unsound property be sold for a sound price, and the vendor knew of the unsoundness, the difference in value may be recovered in assumpsit. And that in estimating the difference, the jury ought to consider the real value of the property at the time of the sale, and deduct that from the price given by the vendor. Doug. 20, 2 Selw. 130.