SALESMAN AND CUSTOMER 265 are found for example in Colombia, at Barran- quilla, Savanilla, Santa Marta, and along the seaboard. It is unwise to send mail in care of the General Delivery. Later on after you have been over the territory and established friendly relations with some dealer or mer chant, mail may be sent in his care. Passports are unnecessary in Latin America. Funds should be carried in the form of Let ters of Credit. It is wise to take one of these in Dollars and Cents and the other in Pounds Sterling, as there will be many opportunities to use one of these advantageously in selling exchange when the other cannot be so em ployed. This all depends of course on the local demands for foreign exchange, and be fore buying money, it is wise to ascertain which letter of credit can be used more profit ably. The saving which can be made in the course of a long trip in closely watching the price of money and buying when conditions favor you, is worthy of your best attention.