Proceedings of the Royal Society of Edinburgh, 375 
Indies, that the universally received opinions of aqueous and 
vegetable putrefaction, single or combined, being the sources 
of this poison, were unfounded ; that putrefaction under any 
shape had no effect in producing it; that it never emanates 
from water in bulk, however putrid that water may be, nor is 
necessarily an exhalation from marshes, but some modification 
of the state of the atmosphere by heat and moisture, being the 
product of a highly advanced stage of the drying process in ab- 
sorbent soils, that had previously and recently been saturated 
with water. The illustrations were principally taken from the 
countries where the author had served with the British armies 
during the last twenty-five years, and exhibited a great variety 
of facts and observations in support of the opinions the paper 
professed to advocate. Other properties of the marsh poison, 
such as its particular adherence to and attraction for lofty um- 
brageous trees and rising grounds in the neighbourhood of 
swamps ; its concentration in ravines, hollows, or leeward loca- 
lities ; its absorption from passing over water, and rarefaction 
or dissipation by the sun’s heat, and regular currents of wind, 
were also pointed out and illustrated. In the course of the 
paper, the author, while treating of the effects of the marsh 
poison, was led to consider its extreme and most baleful pro- 
duct, — the yellow fever of the tropics ; — and the non-conta- 
gious nature of that disease, was established by a series of facts 
and arguments that appeared to be incontestible. It concluded 
with some observations on the mode of reception of the marsh 
poison into the human constitution, whether by the lungs, the 
stomach or the skin, which last the author seemed to think 
was the most probable channel, and supported his opinion by 
some illustrations taken from the plague of the Levant, and 
the peculiar idiosyncracy of the African or Creole Negroes. 
Ja7i. 26.-— At a General vMeeting of the Society, the follow-- 
ing members were elected : — 
Honorary Members. 
His Royal Highness the Prince Leopold. His Royal Highness the Archduke Maxi- 
His Imperial Highness the Archduke milian. 
John. M. le Chevalier Delambre, Perpetual Se- 
cretary of the Academy of Sciences. 
