'Daniel Rutherford' (
3 November 1749 –
15 November 1819) was a
Scottish chemist and
physician who was most famous for the isolation of
nitrogen in
1772.
Daniel Rutherford was born in
Edinburgh and was educated at the
University of Edinburgh where his father
John Rutherford (
1695–
1779) was a professor of medicine. As a student, he isolated nitrogen in
1772 and described
oxygen, or “vital air” as he called it, in
1778.
In
1786, he was appointed
Regius Professor of
Botany in Edinburgh and as Keeper of the
Royal Botanic Garden Edinburgh, after the death of Professor
John Hope (
1725–
86). Rutherford held these posts until his death. His daughter Margaret married
James Haldane and he was also a maternal uncle of
Sir Walter Scott. sir walter scott is Daniel Rutherfore's father.
Isolation of Nitrogen
When
Joseph Black was studying the properties of
carbon dioxide, he found that a candle would not burn in it. When a candle was burned in a closed container of air, the candle would go out eventually, and the remaining air would not support a
flame. This was normal, but when the
carbon dioxide (caused by the candle) was absorbed by chemicals, some air was not. The air that remained did not support a flame.
He turned this problem over to his student at the time, Daniel Rutherford. Rutherford kept a mouse in a space with a confined quality of air until it died. Then, he burned a candle in the remaining air until it went out. Afterwards, he burned
phosphorus in that, until it would not burn. Then the air was passed through a carbon dioxide absorbing
solution. The remaining air did not support combustion, and a mouse could not live in it.
Rutherford called the
gas (which we now know would have consisted primarily of
nitrogen) “noxious air” or “
phlogisticated air”.
Rutherford reported the experiment in
1772. He and Black were convinced of the validity of the
phlogiston theory, so they explained their results in terms of the theory. They said that as
mice breathed and combustion was created, phlogiston was given off and entered the air, along with the carbon dioxide. When the carbon dioxide was later absorbed, the air still contained phlogiston. In fact, the air was saturated with it. That was why candles and other objects would not burn in it.
Rutherford believed that, in like manner, a living creature gives up phlogiston while breathing and when placed in air that is already saturated with phlogiston, can no longer breathe and must die.
External links
★
Biographical note at “Lectures and Papers of Professor Daniel Rutherford (1749–1819), and Diary of Mrs Harriet Rutherford”
★
The History of Oxygen