This term is used to designate the possession by one person of several estates or rights. For example, a right to an estate to which an easement is attached, or the dominant estate, and to an estate which an easement encumbers, or the servient estate, in such case the easement is extinguished. But a distinction has been made between a thing that has being by prescription, and one that has its being ex jure naturae; in the former case unity of possession will extinguish the easement; in the latter, for example, the case of a water course, the unity will not extinguish it. Poth. 166. 2. By the civil code of Louisiana, art. 801, every servitude is extinguished, when the estate to which it is due, and the estate owing it, are united in the same hands. But it is necessary that the whole of the two estates should belong to the same proprietor; for if the owner of one estate only acquires the other in part or in common with another person, confusion does not take effect.