60. Facts bearing upon opinions of experts. Facts, not otherwise relevant, are relevant is they support or are inconsistent with the opinions of experts, when such opinions are relevant.

Illustrations

(a) The question is, whether A was poisoned by a certain poison. The fact that other persons, who was poisoned by that poison, exhibited certain symptoms which experts a firm or deny to be the symptoms of that poisons, is relevant.

(b) The question is, whether an obstruction to a harbour is caused by a certain sea‑wall.

The fact that other harbours similarly situated in other respects, but where there were no such sea‑wall, began to be obstructed it about the same time, is relevant.