The law of sales is based upon the Roman law, in its later stage as modified by the praetors and by legislation. In the Roman law a sale meant originally only a barter; but the introduction of coined money converted the consideration of the purchaser into price (pretium) as distinguished from the article of sale (merx) contributed by the other.1

Far from being a matter of recent development, the law of sales, being an ancient form of contract, is naturally one of almost certain and fixed principles, though it is not possible to say that in a country as vast as ours, and made up of so many different state governments, that there is absolute accord of decision in the law of sales. There is not. We find however, today, that the law of sales has been little changed by any recent legislation and that the law today is for the most part made up of the Common law rules, and that English decisions on question of sales are frequently cited in American courts and are found of special value. It is true also, that our own institutions, and circumstances, have made it essential to make a peculiar application of certain common law principles, and to reject or render obsolete certain rules of the English law, that have not become a part of our jurisprudence.

1 Americanized Encyc. Brittanica, Vol. VIII.