WET LANDS OF SOUTHERN LOUISIANA. 5 



Outside of the city sanitary conditions nre naturally much hetter. The dwell- 

 ings of both owners and the tenants of the plantations stand on the higher land 

 along the Mississippi River, where there is adequate natural drainage \<>t 

 withstanding the proximity of the swamps and standing water, malaria, 

 though occasionally occurring, is not dreaded. Until within the last few years 

 epidemics of yellow fever caused frequent alarm, but this disease has now been 

 thoroughly eradicated, and with the methods of treating the disease and pre- 

 venting its spread it is not to be dreaded as formerly, even if it should again 

 appear. 



Since it has been demonstrated that malaria, like yellow fever, can be 

 transmitted to man only through the bite of a certain species of mosquito, it 

 may be expected that drainage, which destroys the breeding places of these 

 pests, will result in a decrease in whatever malaria now may exist. As a 

 matter of fact, malarial fever is very rare on the immediate coast line, and 

 the health of people who come from other sections seems to be fully as good as 

 that of those born there. 



SOILS. 



The area under discussion contains soils that are peculiar to the section, and 

 these now are being drained and cultivated for the first time. In the follow- 

 ing section are set forth the results of first-hand investigations, along with 

 the classification and general descriptive matter taken from publications of 

 the United States Bureau of Soils. 



Area East or the Atchafalaya River. 



ORIGIN AND FORMATION OF SOILS. 



The soil of the area east of the Atchafalaya River and in parts of St. Mary, 

 Iberia, and St. Martin Parishes is of alluvial origin and is largely the result 

 of deposits made by the Mississippi River and its branches. It has been built 

 up from a depth of several thousand feet to the present elevation above the 

 Gulf. In the very newest portions of the Delta at Port Eads, at the mouth of 

 the river, a considerable subsidence of the land still is going on, the measured 

 rate being about 0.11 foot per year. That this subsidence is due to a compact- 

 ing of the newer deposits is shown by the fact that permanent bench marks 

 along the Mississippi .River record a decreasing settlement as the distance 

 from the mouth of the river increases. Except in this relatively small 

 area near the mouth of the river, the remainder of this section of 

 the State shows no change in elevation. As is typical of delta regions, 

 ridges of sandy soil are found along the main river channel and along its 

 branching outlets. The manner in which these ridges were formed is well 

 brought out in the following from "A Preliminary Report upon the Bluff and 

 Mississippi Alluvial Lands of Louisiana," by W. W. Clendenin. 1 



1 Louisiana Stas. Rpt. Geology and Agriculture, Pt. IV, p. 263. 



With every flood the river now overflows its flood plain and deposits much 

 of the sediment from its headwaters. As with a slight increase in velocity 

 the transporting power is vastly increased, so with a slight checking of ve- 

 locity, as occurs over the flood plain outside of channel, deposit takes place. 

 As the greatest decrease in velocity takes place near the channel, there the 

 heaviest and coarsest sediment is deposited, and in greatest quantity. The 

 river banks are thus built higher -by each flood and a system of natural levees 

 is produced. There is thus a marked difference in the " front lands " and the 

 " back lands '•' along the river. The former are higher and coarser textured 

 than the latter, and therefore much more easily cultivated and drained. 



Drainage from the very channel margin is away from the river, and unless 

 forced by the topography of the land, will not reach the river proper, but 

 unite with some outlet of the river produced during some extraordinary flood 



