300 On Malaria. 



Abt. V. — On Malaria. 



TO PROFESSOR SILLIMAN. 



Dear Sir — The cause of remitting and intermitting fevers, and 

 of the chronic maladies which hang upon the constitution after it has 

 resisted the first attacks, is a subject of the deepest concern, and 

 worthy of the strictest scrutiny. It is of the more importance to 

 pursue it to the most certain issues, because the treatment of diseases 

 similar in appearance, but of diflerent origin, is injurious or sanitive 

 according to the cause of the complaint. This class of disorders has 

 been attributed to marsh effluvia, and to various other sources, in- 

 volving the subject in obscurity and error. Few people are aware 

 of the prevalence of this noxious principle : and when I state, that 

 it is believed by several experimental physiologists to be the cause, 

 in some form or other, of nearly half the diseases which visit the hu- 

 man race, and that its existence, or the means of averting its effects 

 are scarcely known, — I need not urge the importance of awakening 

 public attention, and of appealing to the feelings of interest, patriot- 

 ism, and humanity to unite with science in the investigation. 



Presuming that the plan of your Journal embraces every branch 

 of physical science, I take the liberty to request a place for some 

 observations upon the phenomena of marsh exhalations or malaria. 



It will be my object to shew 



I. That the fever and ague, intermitting and remitting fevers, and 

 some other complaints which afflict different sections of this country, 

 result from those poisonous exhalations called by the Italians maVaria, 

 which are peculiar to the vicinity of marshes. 



II. That this insalubrity may arise from morasses, salt marsh, 

 ponds, canals, swamps, wet pastures and meadows, bogs, newly clear- 

 ed lands, neglected gardens and ruins, and inundated plantations. 



III. That it is practicable to control this deleterious influence, and 

 in most instances to subdue it, by human skill and industry — and that 

 by ascertaining those situations where it is impracticable, the waste 

 of human life at present experienced, may, by suitable defences, be 

 prevented. 



I. There are various opinions of the nature and origin of malaria. 

 Many have attributed the origin of the specific poison to unknown 

 gases, — some to volcanic fumes — electrical agencies — or the myste- 



