The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
    

concept

A lecture on pneumatics at the Royal Institution, London. Coloured etching by J. Gillray, 1802.

Chart of war gases / issued by the Ministry of Home Security.

Chemistry: a piece of steel wire burning in oxygen inside a glass jar. Mezzotint, 1809.

Chemistry: two versions of Woulfe's apparatus for washing gases. Engraving by W. Lowry, 1803.

Memoria sobre una nueva y metodica clasificacion de los fluidos elasticos permanentes y gaseosos de Juan Manuel de Arejula (1755-1830) / introduccion, transcripcion y notas por J. L. Carrillo y R. Gago.

Chemistry: equipment for measuring the volume of gases. Engraving by A. Bell.

A sense of commitment / British Gas.

Van Helmont e o conceito de gás : química e medicina no século XVII / Paulo Alves Porto.

Expériences qui prouvent démonstrativement que le vinaigre de vin neutralise le méphitisme qui s'exhale de toutes les matieres en putréfaction / Par m. Janin de Combe Blanche.

Gases

Images

Catalogue

Memoria sobre una nueva y metodica clasificacion de los fluidos elasticos permanentes y gaseosos de Juan Manuel de Arejula (1755-1830) / introduccion, transcripcion y notas por J. L. Carrillo y R. Gago.

Chemistry: equipment for measuring the volume of gases. Engraving by A. Bell.

A sense of commitment / British Gas.

Van Helmont e o conceito de gás : química e medicina no século XVII / Paulo Alves Porto.

Expériences qui prouvent démonstrativement que le vinaigre de vin neutralise le méphitisme qui s'exhale de toutes les matieres en putréfaction / Par m. Janin de Combe Blanche.