Page:Popular Science Monthly Volume 3.djvu/38

28 the dominant language, and will be almost exclusively used in scientific works.

There are also short but very interesting essays on methods of teaching drawing and developing the observing powers of children, on statistics and free-will, and on a few other subjects of less importance, all of which are treated in a thoughtful manner, and illustrate one of the views on which much stress is laid in this work, viz., that the mental faculties which render a man great in any science are not special, but would enable him to attain equal eminence in many other branches of science or in any professional or political career.—Nature.



HE ancient leprosy, the red plague, and the disease known in Europe as the Black Death, have ceased to afflict mankind. They seem to belong to the evils of the past; their banishment is due to human progress, to a better knowledge of hygiene, and a clearer understanding of the causes that develop infection and produce contagious and epidemic diseases. It is an interesting question to ask, "Will not the small-pox and the cholera, whose effects science has already modified, become extinct diseases?"

The disease known as the black death made its first appearance in Europe at Constantinople in 1347. It was brought there from Asia, probably from the northern coasts of the Black Sea. From Turkey it gradually spread over Europe, almost depopulating whole districts as it travelled north. Florence was terribly smitten. Boccaccio, in the preface to his "Decameron," has left us an account of the sweeping destruction of the Florentines by the scourge, which one who reads can never forget. From Florence it travelled into Spain, swept over France, and crossed the Straits of Dover.

It made its appearance in England late in the summer of 1348. From June to December of that year there was an almost incessant fall of rain. The ground was continually damp, and the streams were polluted by surface drainage. When the sun shone, it was through a misty sky, producing a vapory heat, particularly unhealthy and enervating. In August, a few cases of a disease supposed to be the black death were reported. In September the plague was surely among the people. In November it reached London, and from the capital it rapidly spread into all parts of the kingdom.

The symptoms of this terrible disease, which usually proved fatal, were inflammatory boils and swelling of the glands, similar to those 