MALARIA. 417 



brity. The result of his efforts was, that new and nourishing towns 

 arose on the ruins of the ancient Volsciau cities. The civil wars, how- 

 ever, 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, espe- 

 cially 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 in- 

 dividual named Caecilius 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, how- 

 ever, 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 in- 

 volved 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 perma- 

 nent 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, Geor- 

 gia, 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 

 tne lowest mortality are the New England and Middle States, Wis- 

 consin, 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 Mid- 

 dle 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 



VOL. IX. 27 



