The total liability to any association organized or doing business under the terms of this chapter by a person, company, corporation, or firm for money loaned shall not exceed fifty percent (50%) of the aggregate paid in capital and surplus of said association. The discount of bills of exchange drawn in good faith, against actual existing values of loans made on time secured by warehouse receipts or bills of lading, or actually existing values, shall not be restricted to, or considered as coming within, such limitation of fifty percent (50%).