who has the absolute ownership of something has a right to reap the benefit of all that it is, of all its activities, and of all that it produces. And so if the field is mine, I have a right to the grass, wood, or other commodity which it produces. If the tree is mine, I have a right to the fruit; if the mare is mine, I have a right to the foal; in the latter case the maxim Partus sequitur ventrem is also applied.
Jurists and theologians divide fruits into natural, industrial, mixed, and civil. Natural are such as grass, which grows without human labour and care; industrial are the product of industry, as a book or a new invention; mixed are partly natural, partly industrial, as a crop of wheat or potatoes; civil are such artificial fruits as rent from houses and land, interest from money lent. In all these cases the maxim may be applied, Res fructificat domino. In the case of mixed fruits, if the material belongs to the labourer the whole produce will belong to him; if the material, the field for example, belongs to someone else, then the owner of the field and the labourer whose labour aided in the production of the crop have each their right to a portion of the produce. Whether the crop be divided, or a money equivalent be paid to one or the other, is immaterial.
With regard to improvements made on land or in houses, the general rule is that, Quidquid solo inaedificatur, plantatur, seritur, solo cedit. However, first of all by custom, and in modern times by statute, an outgoing tenant has a right to compensation for the improvements he has made on his holding, provided that certain conditions have been fulfilled.
2. When one thing is added to another, the general rule is that what is accessory becomes the property of the owner of what is principal. And so the owner of land has the property in gradual increments made to it by alluvion; an island formed in a river belongs to the owner of the bed. If a river suddenly changes its course, or the sea suddenly retires, the rule does not hold; the ownership remaining as before. If wood belonging to another has been used in a building, the property is transferred to the owner of the building, with the obligation of making compensation for the wood. Similarly a painting on another's canvas belongs to the painter, but he must pay for the canvas. When a new form has been introduced into the material, as by baking bread, making wine or oil, the product belongs to the workman, but compensation must be made for the material. The ownership is then said to be acquired by specification. When liquids or solids belong-
