Apjohn, John

John Apjohn (1796-1886)

Chemist and Mineralogist

John Apjohn was born in Limerick in 1796.  He was educated at Tipperary Grammar School and Trinity College Dublin (TCD) where he studied for an arts degree (1817). He then qualified in medicine in 1821 and completed an MD in 1837.

Apjohn became interested in experimental science while studying medicine and was appointed to the Royal College of Surgeons in Ireland (RCSI) as a chemistry lecturer, becoming Professor of Chemistry three years later. In a long career, he published 48 papers in chemistry. Apjohn also lectured in the school of engineering in TCD in applied chemistry and mineralogy, and was appointed Professor of Chemistry in 1850, a position he held for 25 years.

Apjohn’s research interests were varied.  He devised a formula for determining the dew point, which bears his name. He published a number of papers on the specific heat of gases. He became interested in mineralogy and described many new minerals, one of which bears his name, Apjohnite, a manganese alum, found in South Africa. He catalogued the mineral collection held in TCD and published a textbook, Manual of the Metalloids, in 1864.

Apjohn was elected a Fellow of the Royal Society in 1853.  He was a Vice-President of the Royal Irish Academy and he received the RIA Cunningham Gold Medal for an essay entitled ‘A new method of investigating gaseous bodies’ in 1837.  Apjohn died in Dublin in 1886.

References

It’s Part of What We Are,   (2007) Charles Mollan , Dublin, Royal Dublin Society.

More People and Places in Irish Science and Technology, (1985) C. Mollan et al. Dublin, Royal Irish Academy.