On Malaria. 317 
‘for wood and water ; but when it is unavoidable, the ‘natives of such 
countries should be procured to perform the labor, and all communi- 
cation with the shore in boats should be in the day time,- at full wa- 
ter; as on the banks of rivers, or on the sea shore, at low watgg, the 
ehulations from the mud are of the most pestilential character. No 
man should go on shore after sun-set when in harbor, nor before 
breakfast, nor be on the decks at all in the night, and the watch should 
be limited to the smallest possible number of men, to whom “smoking 
constantly while in the open air,” should be recommended. Whenever 
‘any part of a crew are necessitated to engage in the dangerous em- 
ployment of wooding and watering, fires lighted at short distances 
would be of great value, and “ ought to be a standing order during 
such service.” No boat should, by any means, be out after sun-set. 
The consequences of inundation after the waters retire, are seen 
in every climate, producing diseases, differing in the degrees of sever- 
ity, from the mild tertian agues of cool climates, occasioned by a low 
meadow or a mill pond ; to the sudden and terrific fevers on the del- 
tas of the Nile and Oronoco, and other rivers of the tropics. In 
‘these regions the heat is continual for long periods; the effects are 
sometimes instant, and the mortality frightful. - 
It is on the rice plantations of our ‘southern Settle in Mobile, 
New Orleans, and the countries which form the deltas of the Missis- 
sippi and its tributaries, that malaria has raised its throne on this con- 
‘tinent ; and were it not for the mysterious ability of the negro to re- 
sist the influences which destroy the white or Caucasian race of 
men, those. vast alluvial regions would, of necessity, be resigned to 
their original denizens. It is a question interesting to naturalists, 
whether this capability of resisting the effects of malaria resides in 
the texture of the negro’s skin, or in'some more latent peculiarity of 
structure or functions; and it is important to medical science, to as- 
certain whether it is resisted by the’ pores of the external and internal 
surfaces, or by respiration, as we may hence discover some clue to 
€ mode of its attack. 
I will detain you with but one other cause of malaria, which I am 
bound not to omit, as it is one of extreme danger, from“its following 
closely upon a very extensively prevailing human oA gid aos 
that is, neglect. 
ere itnot that 1 might injure the value of real estates in some parts 
of this country, I could point out OY. name: several ‘excellent farms, 
