In another chapter we learn how coin and bullion are often sent by express. The same rules apply to shipments of other articles by express. Shippers should always address packages clearly and also put their own names on them. They should always get a receipt from the express company. Express companies are responsible for losses caused by the negligence of their agents. The recipient of an express package must sign a receipt on getting it from the express company's agent. The charges may be prepaid or not, as the sender prefers. If the goods are sent C. O. D. the sender makes out a bill of the goods (giving names of buyer and seller, date and place of sale, kind, quantity and price of the goods, and the terms of the sale). This bill is placed in an envelope called a C. O. D. envelope, which is sent with the goods. Before the goods are surrendered by the express company to the consignee, the express charges for carrying and delivering the goods and the amount of the bill are collected. Sometimes the express company collects charges for the return to the shipper of the money collected. If the company delivers goods, sent C. O. D., without collecting the money it will be liable for any injury suffered by the shipper.