e able to choose the remedy and the dose required. If he
found in a healthy young man apparently the same weight as in
an old and decrepit individual, he might readily be brought to
the conclusion that the young man would surely die, and in
this way have some evidence for his prognosis in the case.
Besides, if in fevers, in the same way, careful studies were
made of the differences in the weight of water for pulse and
respiration in the warm and the cold paroxysms, would it not
be possible thus to know the disease better and, perhaps, also
get a more efficacious remedy?"

As will be seen from this passage, Cusanus had many more ideas than
merely the accurate estimation of the pulse frequency when he suggested
the use of the water-clock. Evidently the thought had come to him that
the specific gravity of the substances, that is, their weight in
comparison to the weight of water, might be valuable information.
Before his time, physicians had depended only on the color and the taste
of the urine for diagnostic purposes. He proposed that they should weigh
it, and even suggested that they should weigh, also, the blood, I
suppose in case of venesection, for comparison's sake. He also thought
that the comparative weight of various roots, stems, leaves, juices of
plants might give hints for the therapeutic uses of these substances.
This is the sort of idea that we are apt to think of as typically
modern. Specific gravities and atomic weights have been more than once
supposed to represent laws in therapeutics, which so far, however, we
have not succeeded in finding, but it is interesting to realize that it
is nearly five hundred years since the first thought in this line was
clearly expressed by a distinguished thinker and scientific writer.

There are many interesting expressions in Cusanus' writings which
contradict most of the impressions commonly entertained with regard to
the scholars of the Middle Ages. It is usually assumed that they did not
think seriously, but speculatively, that they feared to think for
themselves, neglected the study of nature around them, considered
authority the important source of knowledge, and were as far as possible
from the standpoint of modern scientific students and investigators.
Here is a passage from Nicholas, on knowing and thinking, that might
well have been written by a great intellectual man at any time in the
world's history, and that could