The fact that land is a free gift of Nature distinguishes it in various ways from commodities which are produced by man. The peculiarities which are most important from the economic standpoint are (1) that the supply of land is, broadly speaking, fixed and unalterable, and (2) that its quality and value vary, from piece to piece, with a variation which is immense in its range, but fairly continuous in its gradation. These are thus two aspects from which the phenomena of price and rent can be regarded; aspects which it is usual to call, (1) the scarcity aspect, (2) the differential aspect. §2. _The Scarcity Aspect_. The fact that the supply of land is fixed has the following significance. If the demand for land increases, the price will tend to rise. This is also true, for a short period at least, of an ordinary commodity. But, in the latter case, there would ensue an increase in supply which would serve to check the rise in price, and possibly, if production on a larger scale led to improved methods of production, bring the price down eventually below its original level. In the case of land, no such reaction is possible. There is nothing, therefore, to restrain the price (and the rent) of land from rising indefinitely, and without limit, if the demand for it should continue to increase. Conversely, if the demand for land falls off, there is nothing to check the consequent fall in price and rent. In the case of ordinary commodities, the supply would be diminished, because most things are either consumed by being used, or wear out in the course of time, and a regular annual production is therefore necessary to sustain their supply at the existing level. But land remains, whether it is used or not; and its supply is, broadly speaking, just as incapable of being diminished, as it is of being increased. Changes in the demand for land in either direction are thus likely to affect its price in a much greater degree than that in which the price of an ordinary commodity will be affected by a corresponding change in its demand.