A specific trade yields a conspicuous volume of residue of a distinctive character. From its composition and general characteristics it appears to be eminently adapted to a certain duty. But the chemist attached to the industry for which the waste is provisionally ear-marked delves into the problem, only to find that it is totally unfitted for what seemed to be an obvious application. He may even go so far as to assert his doubts as to the material possessing qualifications for any known use, owing to its unfavourable nature, or because application may prove to be too costly. In such an event that residue must remain an apparently redundant product until a possible field for its utilization happens to be found. A case in point may be cited. In the manufacture of boots for the Services enormous quantities of trimmings accumulated, owing to the specifications relative to the selection of skins for official needs being more rigid than obtains for footwear designed for civilian use. These trimmings proved to be quite useless to the trade, and so endeavour became concentrated upon the discovery of some other attractive utilitarian duty for them. The main objection to this residue--curried leather--was the grease. It was decided to remove it--a relatively simple and commercially practicable operation. But in solving the one problem another, every whit as perplexing, was precipitated. The degreased leather could be used, but what was to be done with the extracted grease, the contribution of which was imposing? In appearance this grease resembles the dubbin used for dressing footwear. Seeing that it was recovered from _new_ leather the thought was entertained that this grease might be used in lieu of, or at least to supplement the supplies of, the conventional dubbin. When the chemist took the proposal in hand he speedily shattered all hopes of turning the grease to such account. He produced an analysis which proved that the grease, instead of being a leather preserver as had been anticipated, was really a leather destroyer. The fatty acids were too predominant. Forthwith that grease had to be abandoned as a potential dubbin substitute. Yet the chances are a thousand to one that the chemist will succeed in indicating a profitable use for this reclaimed fat from unused curried leather, because with war we have acquired wisdom. We are not so ready to throw away a substance just because we happen to be ignorant of an immediate industrial application therefor. Rather are we disposed to put forth a little exertion to strive to adapt, or to create, some useful range of service for it. There are hundreds of heads at work throughout the country attacking just such problems as the recovered grease from leather, and, consequently, from such a distribution and concentration of fertility of thought, it is only reasonable to suppose that such issues will ultimately be fathomed satisfactorily to one and all.