DURING recent years there has been much incentive to the study of natural resources of every description. The manifold and complex needs of industrial civilisation are such as to make it invidious to select any aspect of natural resources as being of more vital significance than the rest; but it requires only a little consideration to realise how very important to any country its reserves of mineral wealth must be. These reserves have been described very aptly as “wasting assets,” in contrast with those yielded by the soil, which are reproductive. The quantities of minerals available are limited, and are so small as to justify the suspicion that in two or three generations from the present time it may be difficult, if at all possible, to obtain supplies of many important minerals at a rate sufficiently cheap to ensure industrial expansion, or even to maintain industries at their present level of prosperity. The importance of this prospective impoverishment of resources as regards base metals has been duly emphasised on various occasions recently by Sir Richard Redmayne, Sir Thomas Holland, and Prof. Thomas Turner.