An instrument in which any of the requirements mentioned in the preceding Article is wanting is invalid as a bill of exchange, except in the cases specified in the following paragraphs: 15 A bill of exchange in which the time of payment is not specified is deemed to be payable at sight. 16 In default of special mention, the place specified beside the name of the drawee is deemed to be the place of payment, and at the same time the place of the domicile of the drawee. 17 A bill of exchange which
