Experimenting with chymical bodies: Reinier de Graaf's investigations of the pancreas

In the late seventeenth century, traditions in anatomy and chymistry came together to ground new theoretical and experimental approaches to understanding the animal body. The researches of Dutch experimenters Reinier de Graaf and his mentor Franciscus Sylvius provide keen insight into the ways experiments were constructed, negotiated, and thought about by leading anatomists and physicians of the time. The objects and approaches de Graaf used in the laboratory--ligature, inflation, injection, tubes, vessels, tasting--were derived from broadly Harveian anatomical and Helmontian chymical traditions. Experimental traditions and a comprehensive and materialistic chymical theory of acid-alkali interactions unified the artificial and the natural and allowed de Graaf to create and use hybrid animal-apparatus constructions as tools to collect and assay the key ingredients of digestion and disease.