
    Joy vs. Hopkins.
    The rule that a witness cannot, in general, speak to matters of opipion, does not apply where the value of property is in question.
    And in an action for a breach of warranty, a witness may be asked what the article would have been worth if it had been of the quality which it was warranted to be.
    Error to the Oneida common pleas, to review a judgment of that court affirming a judgment rendered by a justice of the peace. The action in the justice’s court was for the breach of a warranty in the sale of a cow—that the animal was good and young. After evidence as to the warranty and the breach, the plaintiff’s counsel inquired of a witness who had seen the cow, what she would have been worth if good and young, and also what she would have been worth provided she gave four quarts of milk a day. The questions were severally objected to on the ground that they called for matters of opinion, and in both instances the objections were overruled, and the witness gave material testimony on these points. The defendant having had judgment against him in both the courts below, brought error here.
    
      E. J. Richardson, for the plaintiff in error.
    
      W. O. Merrill, for the defendant in error.
   By the Court, McKissock, J.

There was no error in allowing the witness to state what the cow would have been worth if good and young.” The difference between the present value and what it would have been if as represented is the true measure of damages. (Voorhees v. Earl, 2 Hill, 288; Corey v. Gruman, 4 id. 625.) The rule that a witness must state facts and not opinions, does not apply to cases like the present. How else than by the opinion of witnesses could the difference between an article delivered and the sample by which it was sold be determined ? The value of personal property is constantly established by the opinion of witnesses; and so of facts in relation to many other matters. (Lincoln v. Saratoga R. R. 23 Wend. 433 ; Norman v. Wells, 17 id. 136; McKee v. Nelson, 4 Cowen, 355.) So also it was correct to allow the question put to the witness as to what the animal would be worth if it gave but four quarts of milk per day. " The question was, what that cow which the witness had seen and knew, was worth, giving four quarts; and not what an imaginary animal giving that quantity would be worth.

Judgment affirmed.  