586 ON CORAL REEFS AS A CAUSE OF THE FEVER 
nels in the Barrier reefs and Ehrenberg shews from microscopical 
observations that the beds of rivers are principally formed from the 
silicious remains of infusoria killed by the advent of fresh water 
and which the currents retain at the mouth of the rivers. 
Mr. Leisk who has lived for years in the Cocos Islands, and who 
is mentioned by Darwin as affording him much information, tells me, 
that when the living coral in the sides of the Lagoon was exposed 
to the atmosphere by the force of a peculiarly strong trade wind, 
driving back tlie sea, and rain having fallen at that time, it imme¬ 
diately died and blackened, and gave forth such a stench as to be 
intolerable, while the fish that were in the lagoon rose dead to the 
surface, poisoned by the decomposing polyps. This effect of rain 
on exposed coral reefs I have seen again, and again, and even the na¬ 
tives have noticed that after a shower of rain, a coral reef always 
emits a greater stench. Besides this decomposing living coral, my¬ 
riads of animals are to be noticed of the class of Zoophytes, soft 
sponges, Echinee of various shapes and sizes, some even gigantic, the 
length between each angle of the pentagon in one kind being near 8 
inches, as I have measured, all are incessantly in condition of being 
produced and dying, and from all this decomposing matter, of \ 
square mile in extent, I say you have the Malaria produced which 
generates the fever endemic on this part of Blakaug Math 
Nothing of an animal nature on the face of the earth exists to 
equal this coralline source of malaria in extent. Fresh water mar¬ 
shes, though of greater magnitude do not proportionally generate 
such virulent malaria, and if this source of miasm from coral was not 
confined in its operations to a few hours in the day, when the tide 
is at its ebb, the localities possessed of such reels would be more 
fatal than the fabulous valley of death, where the birds were wont to 
drop down dead as they flew over the spot. This being in a conti¬ 
nual state of decomposition, will, according to the theory I have ad¬ 
vocated in the introductory essay, be a source of malaria and also 
be the cause of fever. That decomposing animal matter will cre¬ 
ate fever I need scarcely say is an opinion universally believed in, 
so much so, that I will content myself with quoting a lew passages 
from Copeland’s Diet: of Medicine p. 569.* Such being the con^ 
* « When dead animal matters, or exuvial mix with vegetable substan¬ 
ces, and putrify along with them in a warm and moist air, the effluvium 
assumes a more noxious form, especially if the air stagnates, in the vicing 
