AN UNSETTLED POINT OF EVIDENCE. 233 giving the grounds on which his opinion rested, could not give the details of sales of property, not sufficiently similar to the property in question, to be otherwise admissible in evidence. In another case another judge ruled just the other way, and allowed the wit- ness to state all the details of such sales, even though he had no personal knowledge of the terms of some of them. In a case before county commissioners a witness was permitted to give the details of the appraisals of sundry pieces of property made by appraisers appointed by the Probate Court, and the valuations placed on sundry pieces of property by assessors. The reasons generally urged for the admissibility of such de- tails are that it is an " established rule of evidence that the witness may give the grounds for his opinions," or that " an expert may always give the details on which he founds his opinions." Both of which reasons are fallacious ; since a rule of evidence can not be said to be established until it is declared to be law by the high- est tribunals, however much it may be imbedded in the practice of the lower courts; and no court of final resort has decided that such details are admissible so far as I have been able to ascertain ; while in one jurisdiction such evidence has been adjudged inad- missible. 1 Again, witnesses-to-value are not allowed to testify to their opinions because they are experts, and have science or skill greater than the jurors, but because they have knowledge of the particular facts in the case which the jurors have not, and so by an exception to the general rule of evidence and of necessity they are not confined in their testimony to facts, but may also testify as to their opinions. 2 While, however, there is a wide difference between an expert and a witness-to-value in the difference of the qualifications which make them able to give this exceptional sort of evidence, it is to be observed that the evidence given by either of them is practi- cally the same ; that is to say, they are each of them allowed to testify as to their opinion, and therefore if an expert be allowed to state irrelevant facts, as the grounds and reasons upon which his opinion is founded, reasoning from analogy it might seem that a witness-to-value might do the same. 1 Bollman v. Lucas, 22 Neb. 796. 2 Shattuck v. Stoneham Br. Ry., 6 Allen, p. 115, Chapman, J., p. 117; Wyman v. Lexington & W. Camb. Rd., 3 Met. 316, p. 327 ; Swan v. Middlesex, 101 Mass. 177, Gray, C. J.
