Burden of proving fact especially within knowledge.

    When any fact is especially within the knowledge of any person, the burden of proving that fact is upon him.
     Illustration
     (a) When a person does an act with some intention other than that which the character and circumstances of the act suggest, the burden of proving that intention is upon him.
     (b) A is charged with travelling on a railway without a ticket. The burden of proving that he had a ticket is on him.