y looking for
and devising methods of applying practical principles of science to
ordinary life. As we shall see in discussing his suggestion for the
estimation of the pulse rate later on, he made many other similar
suggestions for diagnostic purposes in medicine, and set forth other
applications of mathematics and mechanics to his generation.

Many of Cusanus' books have curiously modern names. He wrote, for
instance, a series of mathematical treatises, in Latin of course, on
"Geometric Transmutations," on "Arithmetical Complements," on
"Mathematical Complements," on "Mathematical Perfection," and on "The
Correction of the Calendar." In his time the calendar was in error by
more than nine days, and Cusanus was one of those who aroused sufficient
interest in the subject, so that in the next century the correction was
actually made by the great Jesuit mathematician, Father Clavius. Perhaps
the work of Cusanus that is best known is that "On Learned Ignorance--De
Docta Ignorantia," in which the Cardinal points out how many things that
educated people think they know are entirely wrong. It reminds one very
much of Josh Billings's remark that it is not so much the ignorance of
mankind that makes them ridiculous, as the knowing so many things that
ain't so. It is from this work that the astronomical quotations which we
have made are taken. The book that is of special interest to physicians
is his dialogue "On Static Experiments," which he wrote in 1450, and
which contains the following passages:

"Since the weight of the blood and the urine of a healthy and
of a diseased man, of a young man and an old man, of a German
and an African, is different for each individual, why would it
not be a great benefit to the physician to have all of these
various differences classified? For I think that a physician
would make a truer judgment from the weight of the urine
viewed in connection with its color than he could make from
its color alone, which might be fallacious. So, also, weight
might be used as a means of identifying the roots, the stems,
the leaves, the fruits, the seeds, and the juice of plants if
the various weights of all the plants were properly noted,
together with their variety, according to locality. In this
way the physician would appreciate their nature better by
means of their weight than if he judged them by their taste
alone. He might know,