If a person having sold, mortgaged or pledged goods that are in the custody of a warehouseman and for which a negotiable receipt has been issued, continues in possession of the negotiable receipt, the subsequent negotiation of it by that person under any sale or other disposition of the goods to any person receiving the receipt in good faith, for valuable consideration and without notice of the previous sale, mortgage or pledge, has the same effect as if a previous purchaser, mortgagee or pledgee of the goods, as the case may be, had expressly authorised the subsequent negotiation.