Unchanging teaching

Chemistry in the schoolroom: 1806, selections from Mrs Marcet’s ’conversations on chemistry’ 

Hazel Rossotti 

Milton Keynes, UK: Author House  2006 | 167pp | ?8.10 (SB) | ISBN 142590534X 

Reviewed by Alex Johnstone

In her introduction to this book, Hazel Rossotti provides the background, in an interesting and witty way, for this 1806 attempt to popularise chemistry. Nearly 160,000 copies of the book were eventually sold in the UK and North America and it has influenced many chemists down the years.  

Mrs Marcet was a well-to-do lady who developed an interest in and understanding of the science of the early 19th century and was bursting to share her insights with anyone who would pause and read. She invented two imaginary pupils, Emily and Caroline, to whom she was determined to impart her knowledge of chemistry in a tutorial format.  

Never was a tutor so blessed as Marcet. Her pupils are responsive, intelligent, thoughtful and willing to hypothesise out loud. Her teaching is firmly based on practical experience and her pupils constantly challenge her to show them proof. To begin with, the attitude of the girls is much the same as that of pupils today.  

Caroline says: ’To confess the truth Mrs B, I am not disposed to form a very favourable idea of chemistry, nor do I expect to derive much entertainment from it’. This also gives a flavour of the language used by the girls and their tutor: far removed from the standards of modern conversation.  

Despite their misgivings, the subject becomes fascinating to the girls and Caroline states, ’I am as desirous as Emily of prolonging the lesson today’. They deal with the properties of a few elements in a way that makes the modern reader wince. Marcet is a follower of Lavoisier and so there is scant mention of phlogiston, but caloric figures are prominent in her explanations for chemical reactions.  

For all her care in teaching, Marcet falls into the coils of circular argument. She uses observation to raise hypotheses and then uses these hypotheses to ’explain’ the observations. She observes that certain elements react readily and raises the idea of affinity. She then goes on to use affinity (or the lack of it) to explain why other elements do not combine. This is not unusual in modern chemistry teaching. One only has to listen to an undergraduate lecture or look at an elementary textbook, or even an advanced text, to see the same phenomenon today. 

The trio extend their thinking to the environmental consequences of chemistry and even surmise that the smoky (carbone [sic]) atmosphere of 19th century London is conducive to the luxuriant growth of vegetation in the city parks! 

Rossotti has done a service to the chemical community by blowing the dust off this almost forgotten work, but I fear that it will appeal only to the chemical historian and to aged chemists remembering the chemistry of their youth.