contracts. An open or sealed letter, from a merchant in one place, directed to another, in another place or country, requiring him that if a person therein named, or the bearer of the letter, shall have occasion to buy commodities, or to want money to any particular or unlimited amount, either to procure the same, or to pass his promise, bill, or other engagement for it, the writer of the letter undertaking to provide him the money for the goods, or to repay him by exchange, or to give him such satisfaction as he shall require, either for himself or the bearer of the letter.