Crises took place on what were called critical days.
It is a commonplace that a disease tends to reach a
crisis on a fixed day from the commencement,
although the day is not absolutely fixed, nor is it
the same for all diseases. The writer of Prognostic
and Epidemics I. lays it down as a general law that
acute diseases have crises on one or more fixed days
in a series.
In Prognostic Chapter XX the series for fevers is
given thus:--4th day, 7th, 11th, 14th, 17th, 20th,
34th, 40th, 60th.
In Epidemics I. XXVI. two series are given:--
(a) diseases which have exacerbations on even
days have crises on these even days: 4th, 6th, 8th,
10th, 14th, 20th, 24th, 30th, 40th, 60th, 80th,
(b) diseases which have exacerbations on odd days
have crises on these odd days: 3rd, 5th, 7th, 9th,
11th, 17th, 21st, 27th, 31st.
A crisis on any other than a normal day was
supposed to indicate a probably fatal relapse.
Galen thought that Hippocrates was the first to
discuss the critical days, and there is no evidence
against this view, though it seems more likely that
it gradually grew up in the Coan school.
|On the other hand, critical days are not discussed at all
in Coan Prenotions, the supposed repository of pre-Hippocratic
What was the origin of this doctrine? Possibly
it may in part be a survival of Pythagorean magic,
numbers being supposed to have mystical powers,
which affected medicine through the Sicilian-Italian