The Roman Institutional Treatises, after giving their definition of the various forms and modifications of ownership, proceed to discuss the Natural Modes of Acquiring Property. Those who are unfamiliar with the history of jurisprudence are not likely to look upon these "natural modes" of acquisition as possessing, at first sight, either much speculative or much practical interest. The wild animal which is snared or killed by the hunter, the soil which is added to our field by the imperceptible deposits of a river, the tree which strikes its roots into our ground, are each said by the Roman lawyers to be acquired by us _naturally_. The older jurisconsults had doubtless observed that such acquisitions were universally sanctioned by the usages of the little societies around them, and thus the lawyers of a later age, finding them classed in the ancient Jus Gentium, and perceiving them to be of the simplest description, allotted them a place among the ordinances of Nature. The dignity with which they were invested has gone on increasing in modern times till it is quite out of proportion to their original importance. Theory has made them its favourite food, and has enabled them to exercise the most serious influence on practice. It will be necessary for us to attend to one only among these "natural modes of acquisition," Occupatio or Occupancy. Occupancy is the advisedly taking possession of that which at the moment is the property of no man, with the view (adds the technical definition) of acquiring property in it for yourself. The objects which the Roman lawyers called _res nullius_--things which have not or have never had an owner--can only be ascertained by enumerating them. Among things which _never had_ an owner are wild animals, fishes, wild fowl, jewels disinterred for the first time, and lands newly discovered or never before cultivated. Among things which _have not_ an owner are moveables which have been abandoned, lands which have been deserted, and (an anomalous but most formidable item) the property of an enemy. In all these objects the full rights of dominion were acquired by the _Occupant_ who first took possession of them with the intention of keeping them as his own--an intention which, in certain cases, had to be manifested by specific acts. It is not difficult, I think, to understand the universality which caused the practice of Occupancy to be placed by one generation of Roman lawyers in the Law common to all Nations, and the simplicity which occasioned its being attributed by another to the Law of Nature. But for its fortunes in modern legal history we are less prepared by _a priori_ considerations. The Roman principle of Occupancy, and the rules into which the jurisconsults expanded it, are the source of all modern International Law on the subject of Capture in War and of the acquisition of sovereign rights in newly discovered countries. They have also supplied a theory of the