In view of the economies possible from the practice of such a system as I have described, it is somewhat surprising that manufacturing firms should hesitate to include an oil-reclamation plant in the equipment of their establishments. It is likewise somewhat difficult to bring home to them what really can be achieved by the scientific treatment of their waste. In order to popularize the practice, and to further the observance of economies which are inseparable from industrial operations under contemporary conditions, more than one British firm is prepared to advance an attractive commercial proposal. This is that the equipment should be installed and its cost defrayed out of the actual savings effected. Thus, in the case of the installation to which I have made reference, and which deals with the rags accumulating from the maintenance of public service vehicles, such a procedure was initiated. The capital expenditure involved in this instance was approximately £2,200--$11,000, but as the plant recorded a net saving of £450--$2,250--as a result of three months’ work, which is equivalent to £1,800--$9,000--a year, it should be able to defray the whole of the initial outlay within about 16 months. However, all things being equal, it is computed that a reclamation plant submitted to the work which I have described should pay for itself within two years. Experience serves to support this contention, although, under the conditions which at present prevail, the possibility is that such a gratifying achievement would be fulfilled within a shorter period. FOOTNOTES: [1] From engine-room. [2] From blast-furnaces. [3] From power-station. [4] Axle-box waste. CHAPTER XIV BY-PRODUCTS FROM THE WASTE-BIN The exploitation of waste presents grand opportunities for pioneer research and investigation, not only to the chemist, but also to the layman who is fruitful of thought. In the praiseworthy determination to turn residues to advantage there is a tendency to follow the path of least resistance, and to apply them to the fields which most readily suggest themselves. This policy is regrettable. The true scientific solution to the problem lies not so much in the conversion of a refuse into a useful article, as the discovery of the precise province in which it is capable of giving the most lucrative and economic return. This may appear to be a simple issue, but, as a matter of fact, it is one bristling with perplexities, invariably involving the expenditure of appreciable time and profound study. Some of the difficulties to be overcome are of an extremely abstruse technical order, and so can only be resolved through the indefatigability of the chemist, which goes to prove that the scientist really dominates industry and commerce. This fact was advanced many years ago, but it is only really acknowledged to-day.