No person shall be excused or incapacitated from confessing or testifying touching any money or property, or thing in action, so wagered, bet or staked, or lent for such purpose, by reason of his having won, played, bet or staked upon any game, lot or chance, casualty, or unknown or contingent event aforesaid; but the confession or testimony of such person shall not be used against him, in any criminal prosecution, on account of such betting, wagering or staking. (R.C., c. 51, s. 3; Code, s. 2843; Rev., s. 1688; C.S., s. 2143.)