Joseph Black

Black, Joseph 

Born Apr. 16, 1728, in Bordeaux, France; died Dec. 6, 1799, in Edinburgh. Scotch chemist and physicist. Became a professor in Glasgow in 1756 and in Edinburgh in 1766. Honorary member of the Academy of Sciences in St. Petersburg (1783) and Paris (1789).

In 1754, Black discovered (and published the data in 1756) that when magnesia alba (magnesium carbonate) is heated, “bound air” (carbon dioxide) is released from it, forming burned magnesium (magnesium oxide), with a loss of mass. Black noticed at the same time that the burning of limestone involves the removal of bound air. He concluded from these experiments that the difference between “soft” alkalis (that is, carbonate) and caustic alkalis is that bound air is part of the former. Black’s discovery of carbon dioxide laid the foundation of pneumatic chemistry. In 1757 Black discovered melting heat and heat of evaporation (not published until 1779). During 1759–63, Black pointed out the difference between the quantity of heat and its intensity (that is, temperature) and introduced the concept of heat capacity.

REFERENCES

Ramsei, U. “Dzhozef Blek, ego zhizn’ i deiatel’nost’.” In U. Ramsei and V. Ostval’d, Iz istorii khimii. St. Petersburg, 1909.
Partington, J. R. A History of Chemistry, vol. 3. New York, 1962.