Extra compensation to officers and contractors forbidden

The Legislature shall have no power to grant, or authorize any county or municipal authority to grant, any extra compensation, fee or allowance to any public officer, agent, servant or contractor, after service has been rendered or a contract has been entered into and performed in whole or in part, nor pay or authorize the payment of any claim hereafter created against the State, or any county or municipality of the State, under any agreement or contract made without authority of law: Provided, That this section shall not apply to claims incurred by public officers in the execution of the laws of the State.