Why should the general reader take an interest in the Dutch medical teacher Herman Boerhaave (1668-1738)? The most important reason is that in his day, the medical faculty at the University of Leiden was an international hub and a book on its most popular teacher allows us a glimpse of buzzing Enlightenment culture. It was Boerhaave who turned the faculty into a centre of excellence in the early 18th century, attracting students from all over Europe. If you wanted to learn state-of-the-art medicine, Leiden was the place to be. Of all medical teachers, Boerhaave taught the most comprehensive medical courses, based on a clever fusion of the scientifically relevant ideas of others. Of course, his popularity was also helped by the fact that the university welcomed students of all religious affiliations and that Leiden offered excellent facilities for extracurricular activities, as well as tax-free alcohol for its students. Plus ca change: where would Oxbridge be nowadays without the booze?
In the past decade, quite a lot of research has been done on Boerhaave's teaching. It is well known that his pedagogical method was based on the idea that students had to truly understand the basic principles of medicine, which meant that rather than teaching them standard prescriptions and cures, Boerhaave encouraged them to find out for themselves what nature did and how it aided the practice of medicine. Rather than allowing them to slavishly follow a specific medical handbook, he told students to experiment, to think about the causes of disease and to invent new cures. At the same time, he adopted chemistry as an important basis for medicine, since chemistry, in his view, offered the best strategies to investigate the hidden properties of natural bodies.
Here, John Powers elaborates on this story by analysing in more detail the didactics of Boerhaave's chemical teaching, and argues that he transformed chemistry from an artisanal practice into an academic discipline. Powers structures his book around two defining characteristics of Boerhaave's teaching: first, the philosophical rhetoric that he employed to systematise his investigations into nature; and second, his instrument theory as a novel way of understanding chemical action (the last being the most interesting part of the book).
I was very interested to read Powers' opinions on Boerhaave's alchemy, since his interpretation is based on access to Boerhaave's manuscripts, which Boerhaave's nephew took with him to Russia, where he worked as physician for Peter the Great, and which are now kept in the military academy in St Petersburg. In the course of my own research, I never managed to get into the archive, not even by offering bribes of vodka and money. Powers has become the first historian since G.A. Lindeboom (who saw the manuscripts in the 1960s) to study this material.
The 18th century is generally seen as the era in which dodgy alchemy transformed into "acceptable" academic chemistry. In this vein, Powers argues that Boerhaave became very sceptical about transmutational alchemy: he no longer believed it possible to change base metals into gold or to make the philosopher's stone. It is a pity that Powers leaves it at that. He employs a narrow definition of alchemy, which prevents him from recognising that although transmutational alchemy was increasingly frowned upon, alchemical materials and methods were still widely used in medicine, including by Boerhaave and his followers.
This critique notwithstanding, Powers' book offers a rich description of Boerhaave's chemistry that is perhaps not novel on all counts, but will help readers understand why he was the early 18th-century Nestor of academic teaching.
Inventing Chemistry: Herman Boerhaave and the Reform of the Chemical Arts
By John C. Powers. University of Chicago Press. 2pp, £26.00. ISBN 9780226677606. Published April 2012