xx INTRODUCTION

phers credit him with being the first to use a sort of telescope.
He says, Ch. 8, "In observing the skies, if you place lenses
(specilla ocularia) one above another, you will see more clearly'.
But, as Dreyer observes, it is a long way from this discovery to
the telescope.

De Causis Criticorum Dierum

The treatise O. (he Causes of Crhcal. Days, published in
the same volume as Homocentrica, is a purely medical work,
and is his most direet attack on Galen,! of whom he says: / *In
other matters I reverence him as divine...he is so accurate
elsewhere, so philosophic, but he could not investigate every—
thing"'. Galen called those who do not follow the astronomers,
and especially the Egyptians, 'sophists', **but if an Egyptian
god told me this [about the celestial ceause of critical days],
I should not believe him...do not eall me a sophist till you
have read this treatise.... A crisis is a local movement of the
humors.... I have observed crises in countless cases . . . black
bile is usually the cause .. . look out for the meianchol/iae
motus . . . once I was ealled in late, but was able to calculate
from the patient's account of what days had been most pain—
ful, that the illness must have begun on March 1st.^ He gives
diagrams of the course of such fevers and their critical days,
and a study of the humors and their interaetion, which varies
according to their qualities. In Ch. 16 he exhorts all doctors
to rely, as he has done, on observation only. 'This treatise has
not, so far as I know, been translated.

Marguerite of Navarre

About 1534, he was asked by Fregoso, then military com—
mander of the Venetians at Verona, to write for him a poem
in honor of Marguerite of Navarre, to be sent with the present
of a bronze medallion, which showed on one side a head of
Minerva. 'This poem, in about 100 Latin hexameters, is a&
panegyric of the accomplished Marguerite and of her brother
Francis I, who had ^lost all save honor" at Pavia in 1525; as
the opponent of Charles V whom Fracastorius detested, he
could be flattered without insincerity.  'There is no certain evi—

: He could read Galen in the Latin translations published at
Venice 1490, 1541, etc.