Page:A Physical and Topographical Sketch of the Mississippi Territory, Lower Louisiana, and a Part of West Florida.djvu/33



IT is generally not until the middle or latter end of June that the people settled on the Mississippi and Tombigby rivers begin to be visited by disease. The waters of these rivers, which had been rising for three or four months, now begin to recede from the face of the country, leaving huge surfaces of mud and water exposed to the influence of the solar heat which occasions an immense decomposition of water and vegetable substances, and consequently, a copious emission of a gas composed of some of the component principles of these articles. Some experiments performed on what I presume was a similar air gave the following results.

Having obtained in two separate bottles, in each above a pint of the air from the bottom of the Schuylkill, and from a marsh adjoining, it was subjected to the following tests to ascertain its nature.

I. A measure of the air was thrown over lime water in an eudeometer, which did not make it turbid.

II. A measure of pure nitrous air, obtained from the action of the nitrick acid on copper, being added to one measure of the air in the eudeometer, produced no absorption.