The immense improvements and discoveries in the character of soils and fertilisers have already been alluded to. Hundreds of instruments have been invented for measuring, analysing, weighing, separating, volatilising and otherwise applying chemical processes to practical purposes. To the chemistry of the century the world is indebted for those devices and processes for the utilisation and manufacture of many useful products from the liquids and oils, sugar from cane and beets, revivifying bone-black, centrifugal machinery for refining sugar, in defecating it by chemicals and heat, in evaporating it in pans, in separating starch and converting it into glucose, etc. _Oils and Fats._--Up to within this century the vast amount of cotton seed produced with that crop was a waste. Then by the process, first of steaming the seed and expressing the oil, now by the process of extraction by the aid of volatile solvents, and casting off the solvents by distillation, an immensely valuable product has been obtained. The utilising of oils in the manufacture of oilcloth and linoleum and rubber, has become of great commercial value. Formerly sulphur was the vulcanising agent, now chloride of sulphur has been substituted for pure sulphur. Steam and the distillation processes have been applied with great success to the making of glycerine from fat and from soap underlye and in extracting fat from various waste products. _Bleaching and Dyeing._--Of course these arts are very old, but the old methods would not be recognised in the modern processes; and those who lived before the century knew nothing of the magnificent colours, and certain essences, and sweet savours that can be obtained from the black, hand-soiling pieces of coal. In the making of illuminating gas, itself a finished chemical product of the century, a vast amount of once wasted products, especially coal tar, are now extensively used; and from coal tar and the residuum of petroleum oils, now come those splendid aniline dyes which have produced such a revolution in the world of colours. The saturation of sand by a dye and its application to fabrics by an air blast; the circulation of the fluid colors, or of fluids for bleaching or drying, or oxidising, through perforated cylinders or cops on which the cloths are wound; devices for the running of skeins through dyes, the great improvements in carbon dyes and kindred colours, the processes of making the colours on the fibre, and the perfumes made by the synthetic processes, are among the inventions in this field. The space that a list of the new chemical products of this age and their description would fill, has already been indicated by reference to the great dictionary of Watts. Some of the electro-chemical products will be hereinafter referred to in the Chapter on Electricity, and the chemistry of Metallurgy will be treated under the latter topic.