Nürnberg, 1429. Genre: “iatromathematische Hausbücher” (medical-mathematical house-book), which links and systematizes medical and astrological knowledge to create a kind of everyday handbook for medical treatments, especially bloodletting, to be administered by laymen at home. It is based on the medieval idea of the influence of the planets on the health and character of human beings. The mixing of astrology and saints’ days in the calendar is evidence that medieval man saw the heavens as another revelation of God; thus astrology and faith are not at odds. This specimen - a “rich man’s” version, probably commissioned by a wealthy patron - is one of only a handful remaining in the world (1 of 2 by the same artist) and the only known specimen in the U. S. Physical description: parchment (vellum), 41 leaves (one single leaf (fol. 1) and 5 layers of 8 (4x2) leaves; 8 ½ in. 12 ½ in.; bound in modern (1930s?) dark blue buckram boards. Script: Franconian Bastarda, executed in a professional hand. Illuminations: 52 miniatures (some unfinished) by the “Erster Meister des Mendelschen Brüderbuches,” active in Nürnberg, 1425-1437. (Cf. Heinz Zirnbauer: “Geschichte des Mendelschen Brüderbuches und kunstgeschichtliches Würdigung seiner Bilding,” in Das Hausbuch der Mendelschen Zwoelfbrüderstiftung zu Nürnberg, Deutsche Handwerkerbilder des 15. und 16. Jahrhunderts (2 vols., Faksimile & Kommentar, ed. Wilhelm Treue, Karlheinz Goldmann, et al.), München, 1965; Kommentar, pp. 93-97. Painting technique: minor traces of preliminary drawing in black chalk, frequent pentimenti, followed by layers of watercolor, often highlighted in white. Faces and naked bodies show occasional traces of red chalk. Contours, lines, and details - in some cases shadow zones - are carefully sharpened by strokes of black ink. Condition: rather good; but many traces and marks of frequent use; some evidence of modern restoration.