‘ 
1825.) 
OxsEervations on the Causus of, Ru- 
MITTENT Fever, as it occurs on the 
Coasts of the MEDITERRANEAN} with 
Sucerstions for PREVENTING their 
Errects. By HH. Rozerrson, ™.p., 
Author of ‘a’ Work on the “ Natural 
History of the Atmosphere,” &c.* 
(WN the Straits of Gibraltar, and along 
the coasts of the Mediterranean, 
there commonly prevails, during the 
‘spring and autumn, but particularly in 
the latter season, a fever in every re- 
‘spect similar to the endemic yellow fever 
of the West-Indies, and of other coun- 
tries within the tropics; it having been 
found, by repeated observation, that 
wherever the remittent fever is met with, 
it originates uniformlyfrom the influence 
of similar causes ; and it is to the greater 
or less activity of these causes, that this 
disease is more or less prevalent in 
certain situations ;—as their powers 
admit of modification, not only from 
the influence of climate, but also ac- 
cording to local circumstances. 
It is to be premised, that the causes 
of remittent fever likewise give origin, 
in certain circumstances, to intermittent 
fevers; and which causes are generally 
imagined to exist in the exhalations 
arising from stagnant water. It has been 
with much probability supposed, that 
the water giving off this exhalation, 
besides being stagnant, necessarily con- 
tains the decaying remains of animal and 
vegetable matters; these being thought 
essential to the excitation of the noxi- 
ous vapour. It is this vapour that is 
denominated “ Marsh Miasma,” in the 
writings of physicians. ~ 
I am, however, inclined to believe, 
that stagnant water, even when com- 
paratively free from such accidental 
impurities, gives off, in the course of its 
decomposition, a vapour very pernici- 
ous to health ; and which, according to 
circumstances, produces the fevers men- 
* A very imperfect copy of Dr. Robert- 
son’s Observations was printed, about 
eleven years ago, in the “Annals of Philoso- 
phy.” The paper itself, after having been 
submitted to the authorities at home, and 
approved by physicians of the highest re- 
spectability, was,translated into Italian and 
modern Greek, and circulated through the 
medium of the government press, at Corfu, 
in the summer of 1815. It has since been 
reyised by the author; and recent discus- 
sions having given particular interest to a 
subject, in itself of such high importance, 
we are happy in being permitted to present 
itia its improved state to our readers.—=' 
Evry. - 
Dr. Robertson on Remittent Fever. 
1205 
tioned above: Nevertheless, there can- 
not be a doubt that the noxious quality 
of this gas is increased in virtlence, in 
proportion to the quantity of animal 
and vegetable matters existing in the 
-water from which it is-exhaled; and it 
-is, therefore, very probable, that when 
the miasma is derived from waters fully 
impregnated with these decaying mat- 
ters, it is so much more ready to pro- 
duce the severest forms of remittent 
feyer., In like manner, all humid situa- 
tions, and soils that, from their level or 
low positions, do not freely allow the 
rain or water from the higher grounds to 
pass freely off, and which thereby suffer 
periodical inundations, give rise to this 
vapour : as the Pontine Marshes, &c. 
But, besides these circumstances, heat 
is the principal agent in the extrication 
of marsh miasma. It has, accordingly, 
been observed, that exhalations from 
stagnant water, although full of impu- 
rity, are much, less pernicious, or al- 
together innoxious, in cold climates, or 
during the cold season; but which 
manifest their effects during the hot 
season, and seem to increase in yiru- 
lence as we approach the tropics, 
where the diseases occasioned by raarsh 
vapour are met with under the most 
severe forms. 
However, in situations otherwise 
favourable for the production of marsh 
vapour, it is observed, that during the 
hottest season the remittent fever more 
rarely occurs: and this is probably to 
be attributed to the greater force of the 
sun’s rays, thereby producing an exha- 
lation proportionably more rapid, and 
‘by which the decomposition of water 
exposed to their influence is in great 
part, if not altogether, prevented ; and 
by which, in.a corresponding degree, 
the evolution of the noxious vapour 
from that source is diminished: —be- 
cause (as vapour is only water under 
another form, in consequence of being 
united with a greater proportion of 
heat than it combines with in its liquid 
State,) it, therefore, cannot be in any 
manner noxious to health. For this 
reason, the exhalations derived from 
rivers and great masses of water, as 
from spacious lakes, and particularly 
from the ocean—where, in consequence 
of the saline matters dissolved in it, the 
decomposition of the water is, with more 
difficulty, effected by heat—are conse- 
quently rarely pernicious to health, 
The exhalation giving origin to re- 
mittent fever seems to be a peculiar 
fluid, generated by a new abet eth 
) 
