Early Science & Alchemy

Alchemical Reflection

Peter Dear reviews Glass of the Alchemists: Lead Crystal–Gold Ruby, 1650–1750, on view at the Corning Museum of Glass until January 4, 2009.

By Peter Dear | December 7, 2008

A ruby glass goblet (ca. 1690) on display in Glass of the Alchemists.

Corning Museum of Glass
1 Museum Way
Corning, NY 14830
(800) 732-6845

The latest exhibition at the Corning Museum of Glass in Corning, New York, presents examples of decorative glassware crafted using new glassmaking techniques that evolved in northern and central Europe between 1650 and 1750. The narrative thread for the exhibition is a strong one: rather than simply detailing the development of new processes and practices by glassmakers, the exhibition highlights the role of “alchemists” in this work of invention.

In the 17th century there was no clear distinction between the terms chemist and alchemist, just as there was no clear distinction between astrologer and astronomer; the astronomers Johannes Kepler and Galileo Galilei both cast horoscopes, and most of the historical figures we think of as 17th-century “chemists” credited the possibility of transmutation. Glass of the Alchemists focuses on the work of several such chemist–alchemists who produced new ways of making and coloring glass. Chemists such as Johann Rudolph Glauber (he of the salt) and Johann von Löwenstern-Kunckel (he of the phosphorus) wrote on and practiced chemical procedures involving not just transmutation but also, among many other things, the manufacture of glass. Glauber, von Löwenstern-Kunckel, and associates such as Johann Daniel Crafft devised commercially successful new products, such as Crafft’s milk glass (made with bone ash), and hard, carvable crystal glass that resembled quartz (made by adding such things as lead or ground flint). The latter was made in quantity by the Englishman George Ravenscroft in the late 17th century.

The most spectacular achievement of these alchemical glassmakers, however, was the glorious gold ruby glass, perfected by Kunckel in 1678, several examples of which appear on display in the exhibit. The gold is used to create a suspension within the glass that disperses light to create a color that no doubt resembles fine rubies but perhaps resembles nothing so much as blood. The best examples on show, from the late 17th and early 18th centuries, are from Brandenburg and Bohemia: goblets and vases beautifully carved. The use of gold in producing this red glass no doubt appealed strongly to Kunckel’s alchemical interests and before him to Glauber, who had also worked on making red glass. According to alchemical theory gold was the most perfected of the metals, although manufacturing high-end glassware was an astute way of making more of it.

Visitors to the exhibition can also view two rather more workmanlike examples of the alchemist’s art, both the work of Johann Friedrich Böttger, who was associated at one time with Kunckel and who, among other things, attempted to replicate the effect of Chinese porcelain. The pieces are lumps of metal, one silver and the other gold, that Böttger reportedly produced by transmutation in the presence of the king of Poland in 1713. They are, apparently, genuine enough. By the 18th century, however, attempts were well under way by some natural philosophers to establish a demarcation between alchemy and chemistry; the creation of that distinction is an important but still underexamined part of the history of early modern chemistry.

A curious feature of the exhibit is its use of quotations from Glauber, Kunckel, and others on walls or screens that emphasize the spiritual and purificatory work of alchemy. These often explicitly religious expressions are curious in that their relationship to the displayed objects is never explained; the details of the glassmaking techniques are associated with the writings of alchemical writers and practitioners without much indication of how these spiritual aspects of alchemy (which in many respects were essential to alchemy) made a difference. Practically speaking, alchemy might almost have been nothing more than a research-oriented art of manufacturing—which to some extent it was.

The exhibition has been assembled from many museums in Europe (especially Germany) and the United States; the biggest source of objects is, however, the astonishing Corning Museum of Glass itself. There is a splendid catalog of the exhibition, which includes essays by a variety of scholars concerning early modern alchemy and glassmaking, edited by Dedo von Kerssenbrock-Krosigk. The book, the exhibition, and the entire museum are all greatly to be recommended, especially to those who understand, or want to learn about, the special practical nature of chemical science.