“ Possession is of the essence of a pledge in order to raise a privilege against third persons. Casey v. Cavaroc, 96 U.S. 467, 24 L. ed. 779; Wilson v. Little, 2 N. Y. 443, 51 Am. Dec. 307.'
We may, therefore, at once lay out of view the provisions of § 5201, Revised Statutes, prohibiting a national bank from making any loan or discount on the security of its shares of stock, and forbidding the purchase or holding by a national bank of such shares of stock, unless necessary to prevent loss on a debt previously contracted in good faith. ”

“ This brings us to the real question in the case, which is, the validity and effect of the provisions of the charter and by-law of the bank forbidding a transfer of stock where the stockholder was indebted to the bank, and the insertion of a condition to the same effect in the certificates of stock which were held by Levi, and which he delivered to the insurance company, as collateral, when he borrowed money from that company. If those provisions were valid it is obvious that the insurance company took the stock subject to the paramount right which the bank possessed. ”

“ And the doctrine was applied to a by-law adopted prior to the passage of the act of 1864, because it was held that the continued operation of such a by-law was prevented by the act of 1864, as the right to continue it was not saved by the proviso to the repealing clause of that act. ”