Note 425 — Chapter XX · THE LAW OF PROPERTY.

Under the head of material things we must class the qualities of matter, so far as they are capable in law of being in themselves the objects of rights. The qualities which thus admit of separate legal appropriation are two in number, namely force and space. Electricity is in law a chattel, which can be owned, sold, stolen, and otherwise rightfully and wrongfully dealt with. 45 & 46 Vict. c. 56, s. 23. Definite portions of empty space are capable of appropriation and ownership, no less than the material objects with which other portions of space are filled. The interior of my house is as much mine as are the walls and the roof. It is commonly said that the owner of land owns also the space above the surface usque ad coelum. Whether this is truly so is a doubtful point as the law stands, but there is no theoretical difficulty in allowing the validity of such a claim to the ownership of empty space.