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The Green Bag

2. Comparative Tests. Chemical tests on papers other than the one in dispute, or standards — in fact, on entirely extraneous and dis connected papers — may be admitted in evidence for comparison of the results of such tests as between the papers in the case and those outside of the case. Reproduction of similarly made mi croscopic tests are, however, not ad missible. 3. Standards. No writings of other than the exact words or exact names in dispute are admissible. A writing four years distant in date from the one in question is too remote to be admitted. A letter from A to B is not admissible upon the testimony of C, who did not see it written, but to whom A recognized it as being his own writing. A writing admitted to be genuine is yet inadmissible if it be not part of the transaction involved in the suit. The party whose writing is in question may, just before the trial and for use therein, write similar words to them in dispute, and such writings are admissible, although made years after the writing in dispute. In an action on a paper alleged to be forged, where defendant's counsel in cross-examining plaintiff's witness uses writings purporting to be by the party whose writing is questioned, and where plaintiff's counsel at the close of such cross-examination asks defendant's coun sel to put those writings in evidence as standards and the request is refused, and where plaintiff's counsel thereupon calls on the defense for the production of those very papers, and on so obtain ing possession of them offers them in evidence himself as standards, they will be admitted.

4. Scope of Proof. Where it is alleged on one side and denied by the other that the body of a will, as well as the testator's signature thereto, was all in the handwriting of the testator, the proof will be confined to the signature alone, because, for sooth, "if the signature is genuine it does not matter who wrote the body of the will." Where the bone of contention is a writing which is alleged by the plaintiff to have been written by A, and this is denied by the defendant, the defense may, if able, show that A did not write it because he did not write it; but the proof cannot be carried further, to show that A did not write because B did write it. An expert witness may state his opinion, but cannot, even though per mitted by statute, give the facts on which he rests that opinion or his reasons therefor. "It would only con fuse the court and jury for him to give the details." Illustrations tending to explain the witness's testimony are not allowable, even though a statute does provide otherwise. An expert witness may not refer to the data contained in the written memoranda that he made when he examined the papers, but must testify (even in chief) wholly from memory, "otherwise no one could protect him self against such a witness." A diagram made by the witness and used in explaining his testimony is admissible in evidence generally, and its use is not limited to mere purposes of reference, and this even in a murder case. 5. Quality of Proof. Where an expert witness testifies, inter alia, that in his examination of