22 



FARMERS' REGISTER— ON MALARIA. 



hood. In such situations they too often become 

 tlie reservoirs of oifal matter of ever}' descnption; 

 which either by gradual accumulation, maj" finally 

 rise above t)ie sui-face of tlie water, as happened 

 in tlie instance related by Senac, or by evaporation 

 of the water, may become exposed to the action 

 of a hot sun, and in either event may exhale mi- 

 asmata in abundance. 



" But as we have before observed, marshes, 

 strictly so called, are the most fruitful souixes of 

 miasmata. These abodes of this pestiferous air, 

 from their great extent and other circumstances, 

 will often not admit even of any attempt to 

 change their nature; and all that is left us in such 

 cases, is to interpose between them and us, the 

 barriers to the progress of malaria witli which na- 

 ture lias kindly turni'shed us, and which will be 

 mentioned in a future part of this lecture. 



"Though, however, in many cases no favora- 

 ble change can be effected, in numerous other in- 

 stances much has been done to redeem marshes 

 from their noxious state. The experience and 

 industry of man have often triumplied over these 

 laboratories of malaria, and from having been 

 shunned as the foci of disease, they have been 

 converted into the abodes of health and plenty. 

 By a judicious use of ditcliing, so as to drain the 

 soil of its superabundant Avater and subsequent 

 cultivation, by wliich the earth, being frequently 

 turned up to the drying action of tlie sun and air, 

 wonderful changes have been effected. " With 

 the aid of the purifying sea breeze, this course, 

 (says Ferguson,) at the British colony of Dema- 

 rara, within six degrees of the equator, has suc- 

 ceeded in rendering the cultivated portion of the 

 deepest and most extensive morass probably in 

 the world, a healthy, beautiful, and fertile settle- 

 ment."* 



" The Campagna tU Roma, now the abode of 

 pestilence, was once comparatively healthy, and 

 ivas indebted for it in a great measure to the 

 " constant tillage," and " to the extreme attention 

 paid to draining the de])osites of stagnant water," 

 and to the aqueducts wliich then traversed it in eve- 

 ry direction. " These, however, being broken 

 down and destroyed by the Goths, by which the 

 country became overflowed, it soon became exces- 

 sively sicld}'. 



"In the neck below Philadelphia, since it has 

 been drained, its agues have disappeared." 



" The clearing of wet land, should be followed 

 up immediately by cultivation. Land of this de- 

 scription having on it a growth of timber, should 

 never have its wood cut down without the specific 

 purpose and power immediately to devote the soil 

 so cleared to agricultural uses; because experience 

 has tauglit tliat the mere clearing of marshy land, 

 is almost certain to be followed by disease in its 

 neighborhood. In proof of this, Dr. Rush says, 

 " it lias often been observed, that families enjoy 

 good health, for many years in the swamps of 

 Delaware and North Carolina, while they are in 

 their natural state, but that sickness alwa3-s fol- 

 lows the action of the sun upon the moist surface 

 of the earth, after they are cleared. Fortius rea,- 

 son the cultivation of a country should always fol- 

 low the cutting down of its timber, in order to 



"Phil. Journal, No. 13, p. 20. 



prevent the new ground becoming, by its exhala- 

 tions?, a source of disease." 



"Dr. Robert Jackson also eays, that "in this 

 country, (America,) the unhealthiness of a place 

 is often obviously increased by cutting down the 

 woods of the neighboring swamps; therefore, no 

 rule is more liable to exceptions, than that Avhich 

 lias been so generally enforced, namely, that clear- 

 ing a country of its woods invariably renders it 

 healthy; unless the grounds be drained and cul- 

 tivated as well as cleared, the efl'ect is likely to 

 he tlie reverse." 



" Many places, previously healthy, have become 

 immediately sickly upon cutting down an inter- 

 vening Avood between them and the marsh, and 

 on the other hand, many situations before sickly 

 have been rendered liealthy from the growth of 

 trees between them and marshy g'ounds. Dr. 

 Jackson says, " histories aboimd ■\vith examples 

 of destructive epidemics, which have followed the 

 cutting down on the groves which covered mo- 

 rasses or intercepted the approach of malaria."J 



Dr. Lisle in his memoir on malaria, translated 

 by Dr. Johnson, and incorporated in his work on 

 tropical climates, says "upon Mount Argintal, 

 above the village of St. Stephano, there is a con- 

 vent wliich has lost all the reputation lor salubrity 

 it once enjoyed, since the lofty trees by which it 

 was surrounded have been cut down." 



" He also says, " I have been informed by per- 

 sons worthy of credit, that in consequence of fell- 

 ing the wood before Asterna, near the Pontine 

 marshes, Veletri was visited for three successive 

 years by disease which made much greater havoc 

 than usual throughout the whole country." 



"We will now mention those means of obviating 

 the eftects of malaria, which are furnished us by 

 our knoAvledge of some of its properties. The first 

 rule we would suggest under this head, and it is 

 one of cardinal importance too, is by all means 

 to avoid the evening or night air, as well as an 

 exposure to the atmosphere of the morning pre- 

 vious to sunrise. The reason of this rule Avill be 

 obvious, when it is recollected that miasma is dis- 

 persed by heat of the sun, during the day, and that 

 as soon as he withdraws his beams and sinks be- 

 low the horizon, it begins to descend, and remains 

 in the lower strata of atmosphere, until it is again 

 rarifted and dispersed by his kindly rays. The 

 instances already cited, show conclusively this 

 characteristic of malaria, and wiU impress more 

 strongly than any words of mine can do, the ne- 

 cessity and advantage of the caution suggested," 



"Deiiisle says, "the evening dew is so much 

 dreaded at-Rome, that as soon as it begins to be 

 perceived, all the inhabitants shut themselves up 

 in their houses:" and-again, "the people of Italy, 

 and I supi;!ose of all countries Avhere the air is bad, 

 never go abroad, unless absolutely obliged, till 

 after sun rise, when the heat has disjiersed the 

 pernicious vapors that have fldlen during the 

 night." 



"In file next place we would recommend, that 

 the upper apartments of houses should be used 

 fijr sleeping; experience clearly establishing the 

 fact, "that the lotvcr you are the denser are the strata 



