Cook H (2010). Testing the effects of Jesuit’s bark in the Chinese Emperor’s court.
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© Harold J. Cook, John F. Nickoll Professor of History, Brown University, Providence, RI 02912,

Cite as: Cook H (2010). Testing the effects of Jesuit’s bark in the Chinese Emperor’s court. JLL Bulletin: Commentaries on the history of treatment evaluation (

An early record of a successful clinical trial is due to the initiative of the Kangxi Emperor of China (ruled 1662-1722). Returning to France in 1703, the Jesuit Jean de Fontenay—leader of a group of Jesuit missionary scientists—mentioned the affair in a letter to father François de la Chaise, father confessor to Louis XIV (Fontaney 1703).

Fontenay wrote that at the end of 1692 he was called from Canton to the Chinese court in Bejing. Upon arriving, he discovered that the Emperor was ill with ‘a malignant fever’. The Kangxi Emperor had long had an interest in European science, and had recently become curious about European medicine, reportedly witnessing how several people who were apparently dying were cured by taking certain French medicinal lozenges brought by the Jesuits. Although his doctors wanted him to be treated differently, the Emperor decided to try half a dose of a lozenge, which made him better but left some residual episodes of ague. By proclamation he then announced that he wanted to be informed of any cure for ague, and that all people suffering from it should come to the palace to be cured. A great many trials of the reported remedies were made on the sick, some at least under the supervision of male members of the Emperor’s family.

Fontenay and his confrere Claude de Visdelou brought along a pound of the ‘Peruvian cortex’ (often known as ‘Jesuits bark’) that they had recently obtained from their brethren in India, offering it for trial. After discussion with the noble courtiers, they had the bark prepared according to instructions. On the following morning, three people suffering from ague took the bark, one whose ‘fits’ were no longer present, a second at a time when the fit had come upon him, and a third on a day when he was not suffering a fit. All three were kept under observation in the palace, and were pronounced cured. The four noblemen in charge of the trial then tried it themselves, to assure all that the remedy had no ill effects on the healthy, sleeping soundly afterward. The Emperor thereafter took the bark, and quickly got better. Following his cure by the use of the lozenge and bark, the grateful Kangxi Emperor granted the Jesuits new privileges, including the use of a house inside the walls of the palace.

The episode is worthy of remark not only because it shows the experimental attitude of many people in the early modern period, when many new medicines were both developed and tried out in circumstances far from their point of origin. It also demonstrates an awareness of the benefits of trying purported remedies at different stages of a disease’s progress, and of trying them out on those who were not ill to assess their safety. While this example is not an early example of a trial on a large sample of people, nor an example of a double-blind study, it does show how the cautionary principle could lead to relatively complex trials.

This James Lind Library article has been republished in the Journal of the Royal Society of Medicine 2014;107:326-327. Print PDF


de Fontaney F (1703). Letter to F de la Chaise, from Cheu-Chan (a port in the Province of ‘Chekian’), dated 15 February. In: Lettres Edifiantes et Curieuses, Écrites des Missions Etrangeres par Quelques Missionnaires de la Compagnie de Jesus. 34 vols. Paris: Chez Nicolas le Clerc, rue Saint Jacques, à l’Image Saint Lambert, 1703-1776. Vol. 7 (1707): p. 222-232.

An English translation of the relevant section of the letter appears in Travels of the Jesuits, Into Various Parts of the World, Particularly China and the East-Indies. Translated From the Celebrated Lettres Édifiantes & Curieuses [transl. by Mr. Lockman]. 2 vols. London: T. Piety, 1762, p. 112-119. A mention of this episode is also made, in the context of the Emperor’s interest in European medicine, in Joachim Bouvet, The History of Cang-Hy, the Present Emperour of China: Pesented [Sic] to the Most Christian King. London: F. Coggan, 1699, p. 62-68 (French original: Bouvet, Portrait historique de l’Empereur de la Chine. Paris, 1697).