The Romance of Modern Chemistry

CHAPTER XXIV THE VALUE OF THE BY-PRODUCT IT is perhaps difficult for the outsider to realise that the manufacture of useful and valuable materials, which has been rendered possible only by the advance of chemical science, but which we now take so much as a matter of course, has meant at the same time the production of enormous quantities of rubbish. The raw material which Nature supplies may contain only a small proportion of the substance we wish to get from it; the rest is so much refuse, and, unless we can devise some way of using it, has to go on the dust- heap. We extract the gold, and the dross is left. Now rubbish-heaps there will be as long as the world lasts, but provided that they are not a public nuisance, and that they are kept out of our sight, we accept them as a necessary evil. It will be readily admitted, however, that a rubbish-heap which as late as 1888 covered 450 acres of ground, and was then receiving a trifling daily addition of 1000 tons, is no ordinary affair. This heap of alkali waste, about which we shall have more to say later on, was at the same time a public nuisance; the neighbourhood was, and still is, pervaded by a most objectionable odour. There are many other cases in which the waste pro- ducts of a chemical industry, although less obnoxious than alkali waste, accumulate at an altogether un- 269