cause; but he recognised the approach of a pestilence,
independently of unusual natural phenomena, by the more frequent
occurrence of various kinds of fever, to which the modern
physicians would assign a nervous and putrid character. The
endemy originates, according to him, only in local telluric
changes--in deleterious influences which develop themselves in the
earth and in the water, without a corruption of the air. These
notions were variously jumbled together in his time, like
everything which human understanding separates by too fine a line
of limitation. The estimation of cosmical influences, however, in
the epidemy and pestilence, is well worthy of commendation; and
Santa Sofia, in this respect, not only agrees with the most
intelligent persons of the fourteenth and fifteenth centuries, but
he has also promulgated an opinion which must, even now, serve as
a foundation for our scarcely commenced investigations into
cosmical influences. Pestilence and epidemy consist not in
alterations of the four primary qualities, but in a corruption of
the air, powerful, though quite immaterial, and not cognoscible by
the senses--(corruptio aeris non substantialis, sed qualitativa)
in a disproportion of the imponderables in the atmosphere, as it
would be expressed by the moderns. The causes of the pestilence
and epidemy are, first of all, astral influences, especially on
occasions of planetary conjunctions; then extensive putrefaction
of animal and vegetable bodies, and terrestrial corruptions
(corruptio in terra): to which also bad diet and want may
contribute. Santa Sofia considers the putrefaction of locusts,
that had perished in the sea and were again thrown up, combined
with astral and terrestrial influences, as the cause of the
pestilence in the eventful year of the "Great Mortality."