Palace on the Via della
Longara, by draining the soil carefully and covering with a layer of very
close turf all the parts of the surface which could not be macadamized. It
would seem as if this system had been rather successful, since there has
not been this year a single case of fever in the _personnel_ of the new
military college, established in the Salviati Palace; while in the Corsimi
Palace, which is situated on the same side of the Via della Longara, but
which looks out upon that part of the Janiculum which is still uncovered,
there have been some fatal cases of fever.

Furthermore, we have had in Rome, during the past few years, some very
evident proofs of the efficacy of atmospheric methods of purification. I
will confine myself to the relation here only of the most striking
instance, one which has been furnished us in the building up of new
quarters of the city. There was much discussion at first as to whether the
improvements should be undertaken in the parts where they now are or in
the valley of the Tiber, for the uncovered lands of the Esquiline and of
the Quirinal were malarious, and, as nearly everybody then thought that
the malaria of Rome was carried into the city from the coast marshes, it
was supposed that this state of things was irremediable. We opposed to
this view the fact of the salubrity of the Viminal, which is situated
between the Esquiline and the Quirinal, and which ought to be as unhealthy
as the two other hills were the malaria of the latter imported into the
city instead of being indigenous. Believing it to be indigenous, we hoped
that by shielding the surface of these hills from the direct action of the
air (by building houses and paving the streets), the malaria would cease
to be produced there. That is precisely what has happened, for the new
quarters are very healthy. But the malaria is only held in abeyance, and
is not definitely overcome; for if an extensive excavation is made in
these hills, and the contact of the air with the malarious soil is thus
re-established, during a hot and damp season, the production of malaria
commences anew. A complete atmospheric purification is nevertheless the
most stable of all the methods of obtaining a suspension of malarial
production, but unfortunately its realization is very limited, for it is
restricted to inhabited localities and to sodded surfaces.

The ideal method of insuring freedom from malaria should be to obtain a
permanent immunity, t