Recently, the Cruijdeboeck by the South Netherlandish physician and botanist Rembert Dodoens (1517–1585) was digitised. This extensive work, printed in 1554, comprises 952 pages and 964 illustrations. The digitisation is closely connected to the future development of the Hortus Medicus at the Allard Pierson, where the Cruijdeboeck will serve as one of the key works.

Work is currently underway on the creation of a medicinal garden, which is thought to have been located between 1665 and 1682 in the vicinity of what is now the Allard Pierson and the University Library. The planting plan for this garden is based on various works from the Allard Pierson collections. Once completed, the Hortus Medicus, organised into different plant and period sections, will offer extensive information on the role of plants in medicine and the history of gardens.

Humoral theory and medicinal plants

In the earliest section of the garden, which focuses on humoral theory, the Cruijdeboeck plays an important role. Throughout the Middle Ages and for a long time thereafter, European medicine was largely based on this theory. It was assumed that disease arose from a disturbance in the balance between the four “humours” or bodily fluids: blood, phlegm, black bile and yellow bile. These fluids were associated with various temperaments, such as irritability or lethargy, and with qualities like hot, cold, moist and dry, which formed the basis for diagnosing patients. Someone might, for instance, be considered melancholic—literally “black bile-ish”—if believed to have an excess of black bile.

Dodoens’ substantial Cruijdeboeck contains a large number of descriptions of herbs, flowers and other plants that were found primarily in the Low Countries. Almost all plants are depicted in detailed woodcuts. In addition to information on the plants’ names and locations, Dodoens provides an overview of their medicinal properties, explained in terms of humoral theory.

On great burdock (Arctium lappa), a plant that will also be featured in the Hortus Medicus, Dodoens writes: “Groote Clissen zijn verdrooghende ende verteerende. Die cleyne zijn van ghelijcker natueren ende daer en boven noch werm.” In modern terms: warming and drying. Dodoens, himself also a physician, adds several applications for the plants he describes: “Tsap van den grooten Clissen met huenich [honey] ghedroncken, doet water maken, en die urina lossen, ende es seer goet teghen die pijne en weedom der blasen. Met ouden wijn ghedroncken eest goet teghen alle beten en steken van alle fenijnnighe ghedierten.”

Whether these remedies are truly effective is open to question from a modern medical perspective, but the plant is certainly edible and was historically used in cooking more often than today. The young flower stalks are said to taste similar to artichoke. When fully grown, the plant becomes considerably more bitter, as was the case for many medicines of the time. This tradition survives in the expression “to swallow a bitter pill.”