VMs: Bologna, bloodletting, moon phases, volvelles

[Luis Vélez <legal1@xxxxxxxxxxxxx>]

Interesting references to bloodletting, moon phases and astronomical
volvelles used by medical students in medieval Bologna, from David Harley's
website:
http://www.nd.edu/~dharley/HistIdeas/astron-astrol.html


> Bloodletting, a medical treatment intended to rectify the imbalance of bodily
> humours, was regulated by the position of
> the moon, which was considered to exert greatest influence over the human
> body. For instance, every sign of the zodiac was
> considered to rule a part of the human body: the Saggitarius ruled the thighs,
> Pisces the feet, and so on. When the moon was in
> the zodiac ruling a particular part of the body, bloodletting from that part
> was to be avoided, since the attraction of the moon
> might cause excessive bleeding. Numerous medical manuscripts and almanacs
> include the figure of the 'zodiac man' as a
> reminder of the specific influence of the moon. In addition, the power of the
> moon's pulling power varied by its phases, and thus
> almanacs usually showed the phases of the moon.

> Thus, students of medicine at Bologna, for instance, learnt astrology for four
> years, including grounding in Euclid's geometry and
> Ptolemy's Almagest. In addition, they learnt how to use instruments such as
> the astrolabe and the quadrant, and were taught how
> to use the Alfonsine Tables along with their canons. The instruction to use
> astronomical tables indicates that students, or future
> practitioners of medicine were not expected to calculate afresh planetary
> positions each time they needed to make a prognosis or
> conduct blood-letting. Several manuscripts for physicians contain short-cut
> tables or volvelles (paper discs) in order to
> establishing planetary positions and phases of the moon. More frequently,
> practitioners relied on calendars which listed the
> necessary astrological information. Thus mathematics professors at Bologna
> were required to compile the official prognostication
> in order to ensure the dissemination of proper and accurate astrological
> knowledge.