JOSEPH BLACK
Joseph Black was born in Bordeaux, France, on 16 April 1728, one of
fifteen children. His father was John Black, an Ulster wine merchant of
Scots descent based in Bordeaux. When he was twelve, young Joseph
was sent off to school in Belfast to learn Latin and Greek. Four years
later, he enrolled at Glasgow University in 1744 to study arts. After four
years of this, his father persuaded Joseph to take up something more
useful, so he chose medicine. He was an assistant to William Cullen, Professor of
Medicine, who in 1747 had instituted the first lectures in Chemistry. Black moved to
Edinburgh in 1752 to further his medical studies and in June 1754 presented his
dissertation, On the Acid Humour Arising from Food and Magnesia alba. The thesis
dealt principally with value of magnesia as an antacid. Two years later, he returned to
Glasgow as Professor of Anatomy and Botany and Lecturer in Chemistry when William
Cullen was appointed Professor of Medicine in Edinburgh. The following year, Black
was appointed Professor of Medicine in Glasgow. He remained in Glasgow until 1766
when he succeeded Cullen to the chemistry and medicine chairs in Edinburgh.
It is during the early Glasgow years (1750-52) that Black began his work on the
chemistry of "magnesia alba" (a basic magnesium carbonate) and the discovery of what
he called it "fixed air" (carbon dioxide). These experiments involved the very first careful
gravimetric measurements on changes brought about when heating magnesia alba
(with release of CO2) and reacting the products with acids or alkalis. This foreshadowed
Lavoisier's work and laid the foundation for modern chemistry. On returning to Glasgow
as professor in 1756, Black met James Watt (of steam engine fame - then
"mathematical instrument maker to the University") and began his work involving the
concept of latent heat, and the first steps in calorimetry. Here again, it was the
quantitative aspects of his work, which led to his discoveries, particularly in the careful
measurement of heat. "He waited with impatience for the winter” in Glasgow so that he
could do experiments on the freezing and melting of water and water/alcohol mixtures
that led to the concept of latent heat of fusion. He did similar work establishing the idea
of latent heats of vaporization, leading to the general concept of heat capacity or
specific heat.
Black was a popular and effective teacher. Most of his Glasgow students
followed him to Edinburgh when he moved there in 1766. He was noted for his lecturedemonstrations, many of them based on his latest and ongoing researches on
magnesia alba and heat effects. Typically he lectured five times a week, about 128
lectures in all, from November to May each year, attracting students from across Europe
and America. The fact that his Edinburgh chemistry job was unsalaried, with income
derived from student fees, probably provided reasonable incentive for him to make his
lectures popular. He also practiced as a physician during his life.
Black himself was never particularly healthy, suffering lung problems from
childhood infections and rheumatic problems in later life. He became a vegetarian in
later life and seemed to suffer from vitamin D deficiency until he moved to the country,
where the milk from grass-fed, "free range" cows contained more vitamin D than those
raised in dark cow-byres in the city.
He never married, though it appears that he was popular with the ladies and
"performed on the flute with great taste and feeling". Black was a great frequenter of
clubs, usually suitable for "highly respectable literary gentlemen", though it was
apparently not unknown for him and his companions (who included Adam Smith, David
Hume, Alexander Carlyle, James Hutton, amongst other celebrities of the time)
occasionally, and accidentally, to visit less salubrious premises.3
He died, in Edinburgh, on December 6, 1799.
References:
http://www.liv.ac.uk/Chemistry/Links/refbiog.html
http://www.chem.gla.ac.uk/~alanc/dept/black.htm
http://mattson.creighton.edu/History_Gas_Chemistry/Black.html
© 2005, Leopold May
If you have any comments, corrections or suggestions, contact [email protected].
References and further reading...
3. Kent, A. (editor) "An Eighteenth Century Lectureship in Chemistry" (Jackson, Son
and Co., Glasgow, 1950)
3 from the only biography of Black, written by his successor Robison and
printed in A SShort History of Chemistry, J. R. Partington, 3rd edition, (1957)
1 from autobiographical memorandum, The Life and Letters of Joseph Black,
by Sir William Ramsay, Constable, (1918)
2 translation from Latin appears in J Chem Ed (1935), xii, 225, 268