Ttalian Malaria. 339 
an energy which, by rendering the Campagna very sickly, has un- 
peopled the city to the extent which we now behold. 
Before we terminate these considerations, we should say some- 
thing of the diseases which at different epochs, visited the ancient 
Romans, and which they denominated plagues. Plutarch, Livy, 
Dionysius and others speak of those pestilential diseases which over- 
took the city of Rome under its kings and during the republic, and 
which must have occasioned a frightful mortality. But though we 
may not admit the term plague in its most rigorous sense ; some of 
those diseases, which manifested themselves at distant intervals, came 
from Egypt by passing through Greece, as that in the year 573, and 
ravaged not only Latium, but the whole of Italy ; other plagues men- 
tioned by Livy were evidently camp diseases, as those of 287 and 
that of 365 when the Gauls beseiged the Capitol. In short, they 
might be other epidemic diseases which manifest themselves every 
_where under certain conditions. But they were certainly not those 
intermittent fevers which now afflict Rome every year with greater 
or less severity. 
From the preceding observations, we obtain. the following result. 
The first inhabitants of Latium, who established themselves on the 
hills of that desert and marshy country, and who had to struggle 
against many obstacles in order to reduce the soil, were shielded 
against the unwholesome atmosphere by their woolen clothing which 
maintained a continual perspiration, whilst their assiduous and im- 
proved culiuré of the land, contributed to purify the atmosphere it- 
self. But as this culture was again neglected on account of the nu- 
merous devastations which desolated Rome and the Campagna, the 
unhealthy exhalations of the soil were again multiplied, and the intro- 
duction of a lighter dress gave to this unhealthy air an influence 
which it had never before possessed. Brocchi relates that in 1818 
there were admitted into the Hospital du St. Esprit, in the course of 
the months of July, August, and September, above 6000 patients 
attacked with fever by reason of the Malaria. The soldiers who oc- 
cupied the forts on the borders of the sea, had to be relieved every 
three or four days, and nobody was willing to reap the harvest which 
covered the fields. 
Opinions are very various with respect to the cause of this foul 
air. Some attribute it to exhalations of sulphuretted hydrogen,— 
others to those of carbonic acid gas; but as Brocchi observes those 
reasoners seem to have forgotten that all these gases are exhaled in 
