when joseph priestley came to birmingham in 1780, he found an able assistant in keir, who had discovered the distinction between carbon dioxide gas and atmospheric air. keir worked closely with priestley to investigate the properties of gases. on 3 may 1787 keir communicated to the royal society some "experiments on the congelation of the vitriolic acid", and on 1 may 1788 "remarks on the principle of acidity, decomposition of water, and phlogiston". another paper, on "fossil alkali", appeared in 1788 in the "transactions of the society of arts". keir published the first part of his "dictionary of chemistry" in 1789. he discontinued it upon becoming convinced of the weakness of his theory of phlogiston.