Huygens ING and Leiden University present an online edition-in-progress of the Letters of Carolus Clusius

Huygens ING and the Scaliger Institute (Leiden University Libraries) present an ‘edition-in-progress’ of the correspondence of Carolus Clusius, using the collaborative editing tool eLaborate. Carolus Clusius (1526-1609) was one of the central figures of the so-called botanical renaissance of the sixteenth century. His vast correspondence has already gained considerable attention from biologists and historians, but a complete edition was never realized.

Huygens ING and the Scaliger Institute made a big step towards a complete digital edition of the Clusius correspondence by assembling and digitizing all existing transcriptions of the letters in eLaborate (an online transcription tool developed by Huygens ING).

Online edition

The edition, under direction of dr. Esther van Gelder (Huygens ING), now includes metadata belonging to all known 1600 letters, scans of 1170 letters and transcriptions at different stages of completion of almost 1000 letters. Most of these are written by Clusius and a range of persons from all social layers with an interest in natural history, gardening, literature, travel, politics, religion and everyday life. The edition can be viewed at

This web edition is not a scholarly edition in the traditional sense. Due to the many different sources of the (published and unpublished) transcriptions, the quality of the edition is not uniform. Furthermore, virtually no annotation has been added (yet). But by publishing this edition as a work-in-progress, we expect to offer an invaluable source that can be searched, improved and elaborated by everyone.

Researchers and students are invited to browse and search the  online edition and to join the project with new transcriptions, translations, improvements of existing transcriptions, annotations etc. Those interested are most welcome to join the Clusius Community 2.0 and to contribute to this edition! Contact us via