Who Discovered Nitrogen

Joseph Black (1728-1799) was a professor of chemistry in Edinburgh and Glasgow. 

His large contributions to the development of chemistry and physics, and his discovery of magnesium, have been described in Chapter 14 Magnesium and Calcium. In his textbook Lectures on the Elements of Chemistry, Vol. 2, edited posthumously in 1803, he mentions the work of both Carl WiUiehn Scheele and Daniel Rutherford (Black s own student in Edinburgh) in the discovery of nitrogen. 

In fact two (or even three) further pretenders to the throne of priority should be mentioned. In March 1772 Joseph Priestley read a paperh to the Royal Society in London and mentioned the work of Henry Cavendish  

Priestley also accounts for other experiments, to aU appearances his own  

If common air is heated over a metal, instead of charcoal, the gas does not make limewater turbid. When the gas volume is measured (over mercury) before and after the high temperature reaction, the volmme diminishing is 1/5. The air residue, after burning, is somewhat lighter than common air. 

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