Lambert Ormsby was a New Zealand surgeon who migrated to Ireland. He described his inhaler in a letter to the Lancet in 1877.Ormsby listed the advantages of his inhaler as simple, inexpensive, small quantity required to produce sleep, prevents evaporation of ether, portable and small (can be carried in pocket), short time to complete anaesthesia (two minutes) and safe. Disadvantages of this apparatus were that it had to be removed in order to recharge the sponge with ether or when anaesthesia becomes too deep. Considerable carbon dioxide accumulation developed and there would also be some oxygen lack. In thirty years of use, Ormsby's Inhaler underwent certain modifications, an exhalation valve was fitted to the mask and device for recharging the sponge with ether was later added. The Ormsby inhaler was modified by Carter Braine in 1898 with the aim of making it easier to clean. Essentially it is very similar except there is no net around the bag.The inhaler consists of an india-rubber flexible bag enclosed within a net bag to limit expansion. There is a soft metallic mouthpiece with india-rubber tubing around the edge. The tubing had to be purchased separately from the manufacturer. The body contains a wire cage with a similarly shaped hollow sponge into which ether was poured.Maker's details inscribed into metal ring around the bore: Barth Co. London.ormsby, new zealand, carbon dioxide, carbon accumulation, carter braine, portable