Page:Popular Science Monthly Volume 9.djvu/441

Rh. The result of his efforts was, that new and nourishing towns arose on the ruins of the ancient Volscian cities. The civil wars, however, and the devastation which accompanied them, again caused the hydraulic works of the Pontine Marshes to fall into neglect, until they were repaired by Augustus, who constructed several new canals, especially a navigable one skirted by the Appian Way. It was on this canal, at Forum Appii, that Horace embarked one evening, and at the same spot St. Paul first met his countrymen from Rome. Nerva and Trajan both contributed to the drainage of the Pontine Marshes, and left inscriptions, still extant, which testify to their great interest in the project. During the convulsions of the following centuries they were overflowed anew, until in the reign of Theodosius they were once more drained, with most beneficial effect, by a public-spirited individual named Cæcilius Decius. We have no subsequent account of the condition of this region until the end of the thirteenth century, when Pope Boniface VIII. constructed some works to drain it. Leo X. employed the engineer Giovanni Scotti to repair and enlarge the canal of Badino, the principal outlet of the marshes, and Sixtus V. built a large lateral canal. The most important improvements, however, were effected by Pius VI., and a system of effectual drainage was almost completed, when the low condition of the papal treasury and the confusion attendant upon the French Revolutionary invasion completely arrested the undertaking, which up to that time had involved an expense equal to $1,622,000. No new works have since been attempted, although the authorities endeavor to keep the canals clear and the dikes in repair. The greater part of the plain is covered with rich pastures; but, except the post-stations along the highway, and some scattered huts of herdsmen, it has and can have no permanent population.

Taking the United States census of 1870 as a guide for our own country, we find malarial fevers forming a very important feature of the mortality-tables. They are most fatal in Florida, Louisiana, and Texas. Next in order follow Arkansas, Mississippi, Alabama, Georgia, Missouri, Kansas, and Nevada. In another group distinguished by a somewhat less mortality we find New Mexico, the Carolinas, Virginia, Tennessee, Kentucky, Illinois, and Indiana. Those States marked by the lowest mortality are the New England and Middle States, Wisconsin, and Minnesota. In California there is a considerable ratio of mortality, diminishing easterly in Utah, and northerly in Oregon and Washington Territory, while it augments largely toward the south in New Mexico. Since the census was taken, however, that is, since about 1869, there has been noticed an evident extension of the subtile miasmatic agency over regions previously exempt from it, in the Middle and New England States. The increase of mortality by this cause in New York City has been notable, but can scarcely be attributed entirely to local influences. In 1868 there were registered in this city