nemo dat

It is a familiar rule that one who has no title to chattels cannot transfer title unless he has the owner's authority or the owner is estopped. It follows that, in the absence of circumstances creating an estoppel, one without title cannot transfer it by the simple device of warehousing the goods and indorsing the receipts. But if the owner of the goods has permitted another to be clothed with the apparent ownership through the possession of warehouse receipts, negotiable in form, there is abundant ground for protecting a bona fide purchaser for value to whom the receipts have been negotiated.