In an exceptionally remarkable lecture by Professor A. W. von Hofmann, in 1890, before the Congress of German Natural Science held in Bremen, he gave, in concluding, a short description of the life of an inhabitant of a town in the year 1822. He shows us a student of science who at that date is arriving with the coach from Bremen to Leipzig. The journey has lasted four days and four nights, and the traveller is naturally stiff and bruised. His friends receive him, and he wishes to refresh himself a little. But there is yet no Munich beer in Leipzig. After a short interview with his comrades, he goes in search of his inn. This is no easy task, for in the streets an Egyptian darkness reigns, broken only at long distances by the smoky flame of an oil-lamp. He at last finds his quarters, and wishes for a light. As matches do not yet exist, he is reduced to bruising the tips of his fingers with flint and steel, till he succeeds at last in lighting a tallow candle. He expects a letter, but it has not come, and he cannot now receive it till after some days, for the post only runs twice a week between Frankfort and Leipzig.[59] But it is unnecessary to go back to the year 1822, chosen by Professor Hofmann. Let us stop, for purposes of comparison, at the year 1840. This year has not been arbitrarily selected. It is about the date when that generation was born which has witnessed the irruption of new discoveries in every relation of life, and thus personally experienced those transformations which are the consequences. This generation reigns and governs to-day; it sets the tone everywhere, and its sons and daughters are the youth of Europe and America, in whom the new æsthetic tendencies gain their fanatical partisans. Let us now compare how things went on in the civilized world in 1840 and a half-century later.[60] In 1840 there were in Europe 3,000 kilometres of railway; in 1891 there were 218,000 kilometres. The number of travellers in 1840, in Germany, France and England, amounted to 2-1/2 millions; in 1891 it was 614 millions. In Germany every inhabitant received, in 1840, 85 letters; in 1888, 200 letters. In 1840 the post distributed in France 94 millions of letters; in England, 277 millions; in 1881, 595 and 1,299 millions respectively. The collective postal intercourse between all countries, without including the internal postage of each separate country, amounted, in 1840, to 92 millions; in 1889, to 2,759 millions. In Germany, in 1840, 305 newspapers were published; in 1891, 6,800; in France, 776 and 5,182; in England (1846), 551 and 2,255. The German book trade produced, in 1840, 1,100 new works; in 1891, 18,700. The exports and imports of the world had, in 1840, a value of 28, in 1889 of 74, milliards of marks. The ships which, in 1840, entered all the ports of Great Britain contained 9-1/2, in 1890 74-1/2, millions of tons. The whole British merchant navy measured, in 1840, 3,200,000; in 1890, 9,688,000 tons.