By the late eighteenth century, scientists had discovered certain types of gas, such as 'fixed air' (carbon dioxide), but their composition was little understood. Relatively few investigations into gases had taken place, and so the polymath Joseph Priestley (1733-1804) was able to make major breakthroughs in the field using a range of experimental techniques. While living near a brewery, he found that it was possible to outline the shape of the gas above fermenting beer with smoke, and that fire would burn with varying strength depending on the composition of the air. This three-volume collection first appeared between 1774 and 1777. Primarily an account of Priestley's early experiments, with details of apparatus including candles and live mice, Volume 1 is reissued here in its corrected 1775 second edition and also incorporates a brief history of the field of inquiry.