316 On Malaria. 



as has has ah'eady been shewn, are productive of disease ; and this 

 sufficiently accounts for the distresses often suffered by the pioneers 

 in new settlements, while the disappearance of those endemic mala- 

 dies after the country has changed its aspect by cultivation, proves 

 that we have not mistaken the cause.* 



Another source of malaria remarked by Dr. McCulloch, is bilge 

 water, to which be charges a great proportion of the sickness expe- 

 rienced on shipboard since the disappearance of the scurvy. It is 

 his opinion, that the noxious effluvia are generated in hot climates by 

 the action of the bilge water upon the wood of the ship itself, often 

 augmented by corn, coffee and sugar cargoes, and sometimes by the 

 quality of the ballast. It is notorious that grain and sugar, by sifting 

 through the seams, render the bilge water excessively offensive, and 

 Dr. McCulloch instances the most destructive fevers, proceeding 

 from that cause. Gravel and mud ballast are also conducive to simi- 

 lar results, while iron ballast is safe. The simple and easy remedies 

 for this evil are ventilation, and washing the ship every day by the 

 plug, until the water drawn by the pumps is as clear, as that in the 

 sea outside of the ship. A most thorough attention to ventilating the 

 hold is also essential, because there is the origin and residence of the 

 evil. The efficacy of this practice has been tested by experiment 

 in the British naval and merchant service. -j- Another exposure of 

 ships to this class of diseases, is from communication with the har- 

 bors and shores of tropical climates. Although it is not practicable 

 to bring this set of dangers under as positive regulations as the for- 

 mer, yet great perils may be avoided, which are now thoughtlessly or 

 ignorantly incurred by ships' companies in tropical regions. It has 

 been ascertained that malaria has been distinctly propagated to a 

 ship at anchor, five miles distant, and that a fatal cholera occurred 

 instantly three miles from the land, upon a shift of wind. J It is there- 

 fore extremely desirable that ships should not approach such shores 



* " The longfevei', one form of the bilious remittent, is nearly extinct ia the mar- 

 atime states, although eighty years ago, it was one of the most terrible diseases of 

 this climate. Where the country has been cleared one hundred and fifty ye-.rs, the 

 long fever is unknown." — ^Vebster on Pestilence. 



t From what is known of the astonishing powers of chlorine in destroying poisons, 

 it is not too much to hope, that it may prove an efficient auxiliary in extinguishing 

 or counteracting (he '' malaria of ships," perhaps even of superjeciing (he necessity 

 of any other application, although it should never be substituted for thorough clean- 

 liness. ! JMcCuIloch on Malaria oa shipboard. 



