William Cullen and the early teaching of chemistry #oldtimechem

They don’t make student satisfaction quotes like they used to in the old days:

“Dr Cullen was always at pains to examine his students from time to time on those parts of his course that had already been delivered; and wherever he found any one at a loss, he explained it anew, in a clear, familiar manner, suited to the capacity of the student.”

This quote was from a former student of William Cullen, who took up the Chemical Lectureship at Glasgow in 1747. He held the first independent chemistry lectureship in Britain and Ireland, with chemistry previously being what we today consider a service course to medicine. Funding for the post came by delaying the appointment of a Professor of Oriental Languages. Cullen was provided with money to set up his laboratory, and spent £52 “building furnaces and fitting up a laboratory and furnishing the necessary vessels for it”. The vessels were identified in a letter from Cullen’s brother-in-law who was trying to source a suitable glass-blower: a tabulated retort, a double-necked receiver; a quilled receiver, a funnel, and a connecting tube. Books requested by Cullen at the same time included Johann Heinrich Pott’s Excertitationes Chymicae, published in Berlin in 1738.

What did Cullen teach? A syllabus from 1748 survives, and shows that this was an exciting time for chemistry. Lavoisier was only 4 years old when Cullen took up his Lectureship, and the subject was still in its infancy. Cullen wished to expand it from the narrow confines of application to medicine, instead highlighting its application to a variety of areas of importance.  He wrote in one lecture: “it has been taught with very narrow view”.  Alluding to the agricultural and industrial relevance of chemistry, he continued:

It is the chemist who from these stones and earths procures malleable metals. It is the chemist who gives to these metals the degree of hardness, ductility, elasticity, or other property that fits the several purposes.

The syllabus contained an introduction to the history and use of chemistry, followed by a consideration of the doctrines of the primary causes of chemical reactions (“changes in bodies occurring in chemical operations”) and discussion on solution, distillation and fusion.  Particular emphasis was then given to three major subdivisions: salts (considering acid and alkalis), sulphurs (considering natural products), and waters (with mineral waters).

There was a strong emphasis on practical chemistry. Lectures often opened with a demonstration. Alarmingly, one included the preparation of nitric acid, and the regenerating of potassium nitrate, to illustrate the nature of ‘mixts’. Unusually, and probably uniquely, he encouraged inquiry by students, introducing voluntary practical classes. But Cullen learned a lesson then that chemistry lecturers have been learning ever since: if you don’t assess it, they don’t do it. He lamented in his final lecture to students that:

I proposed that during the course you should have acquired some knowledge [of experimental manipulation] in this way. The laboratory has been open to you, but I am sorry to find that so few of you have frequented it.

After a time at Glasgow, Cullen moved to Edinburgh, starting a course there on 12 January 1756.  Initially he was meant to take the Chair held by Plummer, but Plummer decided to hold on a little longer, and it wasn’t until illness struck him in 1755, that the way was paved for Cullen to become Chair of Medicine and Chemistry. His appointment was controversial: other names had been suggested for Plummer’s replacement, including joseph Black, who was Cullen’s stellar assistant at Glasgow.  But the Town Council, who had over-riding power of the University in accordance with the Charter of James VI, gave Cullen the nod. At Edinburgh, he continued expanding the breadth of the subject he taught. Indeed, his work on fermentation gives credit to the claim that he was one of the pioneers of biochemistry. As the opening quote illustrates, he was a popular teacher at Edinburgh, with student numbers in his classes growing from 17 in his first year, to 59 in the second. Up to 145 students attended his sessions.

Cullen was eventually replaced by Joseph Black, who had acted as his assistant for a course in Glasgow, and had moved to Edinburgh to complete his medical studies in 1752. After Cullen’s appointment to the Chair, Black went to Glasgow as a lecturer in chemistry, and returned to Edinburgh in 1766, replacing Cullen as Professor of Chemistry. Cullen himself was promoted to the Chair of Institutes of Medicine at Edinburgh. His two decades of teaching chemistry at Glasgow and Edinburgh were characterised by an interest in conveying the breadth of the subject and its variety of applications. He had the hallmarks of what we would today consider a reflective practitioner. In 1760 he wrote:

It will only be when the languor and debility of age shall restrain me that I shall cease to make some corrections of my plan or some additions to my course.

Published for the #oldtimechem theme running for the 2015 #Realtimechem week

Sources:

1. G. W. Anderson (1978) The Playfair Collection and the Teaching of Chemistry at the University of Edinburgh 1713 – 1858, The Royal Scottish Museum: Edinburgh.
2. P.D. Wightman (1955) William Cullen and the teaching of chemistry, Annals of Science, 11(2), 154-165.
3. P.D. Wightman (1956) William Cullen and the teaching of chemistry—II, Annals of Science, 12:3, 192-205

Web sources:

Glasgow Chemistry: http://www.gla.ac.uk/schools/chemistry/aboutus/history/williamcullen/

Edinburgh Chemistry: http://www.chem.ed.ac.uk/about-us/history-school/professors/william-cullen

The Cullen Project: http://www.cullenproject.ac.uk/