155. The credit of a witness may be impeached in the following ways by the adverse party, or, with the consent of the Court, by the party who calls him:-

(1) by the evidence of persons who testify that they, from their knowledge of the witness, believe him to be unworthy of credit;

(2) by proof that the witness has been bribed, or has accepted the offer of a bribe, or has received any other corrupt inducement to give his evidence;

(3) by proof of former statements inconsistent with any part of his evidence which is liable to be contradicted;

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Explanation.–A witness declaring another witness to be unworthy of credit may not, upon his examination-in-chief, give reasons for his belief, but he may be asked his reasons in cross-examination, and the answers which he gives cannot be contradicted, though, if they are false, he may afterwards be charged with giving false evidence.

Illustrations

(a) A sues B for the price of goods sold and delivered to B. C says that A delivered the goods to B.

Evidence is offered to show that, on a previous occasion, he said that he had not delivered the goods to B.

The evidence is admissible.

(b) A is indicted for the murder of B.

C says that B, when dying, declared that A had given B the wound of which he died.

Evidence is offered to show that, on a previous occasion, C said that the wound was not given by A or in his presence. The evidence is admissible.