Samuel Nelson, Packet Company v. Sickles (72 U.S. 580…
“ But it is proper to say, that the secret deliberations of the jury, or grounds of their proceedings while engaged in making up their verdict, are not competent or admissible evidence of the issues or finding. The jurors oftentimes, though they may concur in the result, differ as to the grounds or reasons upon which they arrive at it.The evidence should be confined to the points in controversy on the former trial, to the testimony given by the parties, and to the questions submitted to the jury for their consideration, and then the record furnishes the only proper proof of the verdict. ”
