180 MICROBES, FERMENTS, AND MOULDS. 
of the subjects of intermittent fever. By exposure 
during the night of little glass plates in marshy 
meadows, Salisbury was able to collect similar spores, 
which settled on the lower surface of the glass, an‘ 
were found floating in the drops of condensed dew.* 
On passing through these marshes in the evening, 
there was a peculiar sense of dryness in the throat, 
and expectoration revealed the presence of spores of 
Palmella. Finally, earth taken from these marshes 
was found to be full of the same organisms. 
When the marsh begins to dry up, the spores are 
produced in abundance, and intermittent fevers occur. 
Salisbury writes that “in 1862, the weather was very 
wet until about the Ist of July; but that during 
July, August, and September, there was hardly a drop 
of rain. The springs and water-courses were nearly 
dried up, the marshes and wet grounds also became 
dry, vegetation was almost completely arrested, and 
the whole country presented an arid appearance. 
Shortly after the drought began, intermittent fever 
made its appearance in all the unhealthy districts, and 
spread so rapidly during the months of July and 
August, that it attacked almost every family living 
on marshy ground. 
“A low, peaty meadow extends along the canal 
* We must repeat what has been said before, that the presence 
of these apores in the air is quite independent of that of the vapour 
which constitutes dew; in other words, the vapour does not transport 
these spores, which must, on the contrary, be perfectly dry before they 
can float in the air and settle on any dump object. 
