1022 Transactions of the Ameeican Institute. 



the idea that there might be materials in the air that were prcvju- 

 dicial to human health, was prevalent among the Jews and Greeks. 



AYe shall aim to illustrate the following points : 



1st. "What means have we of detecting malaria ? 



2d. WJiat are the conditions under which malaria is produced ? 



3d. "What are the nature and properties of it ? 



4th. The means nature has instituted to destroy it. 



5tli. The means artificially produced for its destruction. 



Before proceeding to the discussion, I shall be excused for intro- 

 ducing a case of personal experience, not because it is personal, but 

 from, to me, the impressive facts it contains. In 1835, 1 was residing 

 in Macon, Ga., connected with a literary institution. As was my 

 practice after the duties of the day were over, I wandered over the 

 country in pursuit of objects of natural history. I, one evening in 

 the early part of July, having been up the Ocmulgee, returned to a 

 boat yard, occupying a flat space between the river and the bluff on 

 which the city is located. I sat on a piece of timber, and at once felt 

 a strange sensation, as potential in its character as a puff of tobacco 

 smoke in my face would have produced. I immediately became sick, 

 the sickness accompanied by a violent headache. I returned home, 

 which was but a short distance, and was, in one hour from the time 

 of leaving the boat yard, in a violent fever, which assumed the type 

 of malignant bilious. It was an entire year before I entirely recov- 

 ered.' It will not appear strange, that I was deeply interested in the 

 cause of my sufferings. Thousands of times I mentally queried, 

 what was it that I breathed ? I made diligent inquiry for light on 

 the subject, but could gather nothing but the fact of th© existence of 

 a material called malaria, of which no one seemed to know anything. 

 The Annalles de Hj-giene had then been a few years in existence, 

 and nothing satisfactory could be learned from its interesting pages. 



Eigana collected bottles of condensed malaria from the Pontine 

 marshes; Bauquelin analyzed it, and found it to be a nitrogenous 

 body, highly putrescible. Thinard and Dupuytrin made the gas of 

 marshes to pass through water, and it deposited a floculent material 

 highly putrescible. 



Moscati condensed the vapors over rice fields in glass globes, and 

 at the end of a few hours, at a temperature of about 100 ^ Fahren- 

 heit, it putrefied, giving off an animal odor. 



Savi obtained from foitia emanations a substance which he culled 

 puterine. By our own experiments we substantiated the facts of the 



