One of the “Adjunct Scholars” of the Vatican Observatory is Dr. Michelle Francl, professor of chemistry at Bryn Mawr College, a noted women’s university near Philadelphia, Pennsylvania (USA). Along with her scientific research, she writes extensively on faith and science issues and as a popularizer of science. For example, in a recent podcast for the Vatican Observatory she told the story of tasting “heavy water” where the deuterium isotope of hydrogen replaces regular hydrogen in the water molecule.
Her latest work combines this sense of fun with solid scholarship… and a few Jesuit connections as well.
Her new book Steeped: The Chemistry of Tea, published in January by the Royal Society of Chemistry, explores the chemistry of traditional tea, that made by steeping leaves plucked from Camellia sinensis trees. The genus Camellia, which includes the familiar flowering camellia plants, was named by Carl Linnaeus in honor of the seventeenth-century Jesuit botanist Br. Georg Kamel.
Kamel was trained as a pharmacist at the Jesuit College in Brno (where Gregor Mendel would do his groundbreaking work). Missioned to the Philippines in 1686, Kamel undertook a systematic exploration of the local medicinal plants. Though he did not describe the tea plant in his writings, he did describe other plants in the same family. Kamel also described Saint Ignatius’s beans, a source of strychnine. This work would eventually lead to the isolation of quinine and caffeine from their plant sources a century later, and then to elegant methods for synthesizing new pharmaceuticals in the twentieth and twenty-first centuries.
Tea leaves expand dramatically in hot water, to almost five times their volume. Thus, tea bags or baskets must be able to accommodate this expansion. Dr. Francl measured the volumes of different tea infusers; many proved to be too small to be effective. Measuring the volume of an object that has holes in it presents a challenge, since the usual measuring methods require immersing the object in a liquid. Instead, she used a method pioneered at the Vatican Observatory for measuring the volume of meteorites, where small glass beads substitute for the liquid. (Br. Consolmagno was inspired to use beads for meteorite measurement by the large grain sugar used in Italy to sweeten coffee. The text on the jacket of Steeped notes that the only place Dr. Francl drinks coffee is in Rome!)
Steeped notes a role tea played on the International Space Station. Tea leaves were set adrift there in a last-ditch attempt to find an air leak. In this case, “reading the tea leaves” worked.
While tea contains thousands of different chemical compounds, the compound that is at the highest concentration is water. A section of the book is devoted to the chemistry of water. Some of the background information for that section derives from the 2016 Vatican Observatory Summer School on water in the solar system, which Dr. Francl attended.
The book also looks at the relevant work of two other religious scientists. Doctor of the Church, herbalist, and Benedictine nun Hildegard of Bingen advised taking special care with the source of water when preparing herbal infusions, advice also seen in eighth-century Chinese manuscripts. And the eighteenth-century Florentine priest and mycologist Pier Antonio Micheli characterized the mold that is used to produce pu’erh style tea. He named the mold Aspergillus niger for its resemblance to the aspergillum used in liturgical sprinkling rites.
The words on the Vatican Observatory’s telescope dome atop the papal palace in Castel Gandolfo (Deum creatorem venite adoremus) encourage us to look out into the universe and see the Creator’s hand in creation. For Dr. Francl, her deep dive into the beautiful molecular complexities of a cup of tea opened a similar door: God in all things, from the unimaginably large to the infinitesimally small.