Selecting a time for bleeding usually depended on the nature of the disease and the patient’s ability to withstand the process. Galen’s scheme, in contrast to the Hippocratic doctrine, recommended no specific days.[24] Hippocrates worked out an elaborate schedule, based on the onset and type of disease, to which the physician was instructed to adhere regardless of the patient’s condition.
Natural events outside the body served as indicators for selecting the time, site, and frequency of bloodletting during the Middle Ages when astrological influences dominated diagnostic and therapeutic thought. This is illustrated by the fact that the earliest printed document relating to medicine was the “Calendar for Bloodletting” issued in Mainz in 1457. This type of calendar, also used for purgation, was known as an Aderlasskalender, and was printed in other German cities such as Augsburg, Nuremberg, Strassburg, and Leipzig. During the fifteenth century these calendars and Pestblatter, or plague warnings, were the most popular medical literature. Sir William Osler and Karl Sudhoff studied hundreds of these calendars.[25] They consisted of a single sheet with some astronomical figures and a diagram of a man (Aderlassmann) depicting the influence of the stars and the signs of the zodiac on each part of the body, as well as the parts of the anatomy suitable for bleeding. These charts illustrated the veins and arteries that should be incised to let blood for specific ailments and usually included brief instructions in the margin. The annotated bloodletting figure was one of the earliest subjects of woodcuts. One early and well known Aderlassmann was prepared by Johann Regiomontanus (Johannes Müller) in 1473. It contained a dozen proper bleeding points, each suited for use under a sign of the zodiac. Other Aderlassmanner illustrated specific veins to be bled. The woodcut produced by the sixteenth-century mathematician, Johannes Stoeffer, illustrated 53 points where the lancet might be inserted.[26]
“Medicina astrologica” exerted a great influence on bloodletting. Determining the best time to bleed reached a high degree of perfection in the late fourteenth and fifteenth centuries with the use of volvella or calculating devices adopted from astronomy and navigation. These were carried on a belt worn around the waist for easy consultation. Used in conjunction with a table and a vein-man drawing, the volvella contained movable circular calculators for determining the accuracy, time, amount, and site to bleed for an illness. The dangers of bloodletting elicited both civic and national concern and control. Statutes were enacted that required every physician to consult these tables before opening a vein to minimize the chance of bleeding improperly and unnecessarily. Consultation of the volvella and vein-man was more important than an examination of the patient.[27] (Figure [3].)
For several centuries, almanacs were consulted to determine the propitious time for bleeding. The “woodcut anatomy” became a characteristic illustration of the colonial American almanac. John Foster introduced the “Man of Signs,” as it was called, into the American almanac tradition in his almanac for 1678, printed in Boston. Other examples of early American almanacs featuring illustrations of bleeding include Daniel Leed’s almanac for 1693, printed in Philadelphia, and John Clapp’s almanac for 1697, printed in New York.
As in many of the medieval illustrations, the woodcut anatomy in the American almanac consisted of a naked man surrounded by the twelve signs of the zodiac, each associated with a particular part of the body (the head and face with Aries, the neck with Taurus, the arms with Gemini, etc.). The directions that often accompanied the figure instructed the user to find the day of the month in the almanac chart, note the sign or place of the moon associated with that day, and then look for the sign in the woodcut anatomy to discover what part of the body is governed by that sign. Bloodletting was usually not specifically mentioned, but it is likely that some colonials still used the “Man of Signs” or “Moon’s Man” to determine where to open a vein on a given day.[28]
Figure 3.—Lunar dial, Germany, 1604. Concentric scales mark hours of the day, days, months, and special astrological numbers. In conjunction with other dials, it enables the user to determine the phases of the moon. (NMHT 30121; SI photo P-63426.)
The eighteenth-century family Bible might contain a list of the favorable and unfavorable days in each month for bleeding, as in the case of the Bible of the Degge family of Virginia.[29]
Barber-Surgeons