Facts which are the occasion, cause or effect of facts in issue
7.  Facts which are the occasion, cause or effect, immediate or otherwise, of relevant facts or facts in issue, or which constitute the state of things under which they happened or which afforded an opportunity for their occurrence or transaction, are relevant.
Illustrations
     (a)  The question is whether A robbed B.
     The facts that shortly before the robbery B went to a fair with money in B’s possession, and that B showed or mentioned the fact that B had it to third persons, are relevant.
     (b)  The question is whether A murdered B. Marks on the ground produced by a struggle at or near the place where the murder was committed are relevant facts.
     (c)  The question is whether A poisoned B. The state of B’s health before the symptoms ascribed to poison and habits of B known to A which afforded an opportunity for the administration of poison, are relevant facts.