By the word "sale" we mean the transfer of ownership of personal property from one person to another for a consideration called the price. By a contract to sell we mean a contract to make such a sale. When ownership passes from one person to another, we say that title passes. There are a number of rules for determining when this title passes, the two basic rules being that title to future goods and to unascertained goods cannot pass; and that when the goods are ascertained, title passes according to the intention of the parties; there being a number of rules designed to arrive at that intention. As a separate volume in this series is devoted to Sales of Personal Property, further discussion is not made here.