Three Hewitt's modification of Clover's portable ether inhalers, three g;ass bottles and two leather cases, made by Thackray, Leeds, 1901-1920

Joseph Clover (1825-1882) invented a portable ether inhaler in 1877. Frederick William Hewitt (1857-1916), a British anaesthetist, modified Clover’s invention in 1901. Hewitt’s modifications made the patient more comfortable and reduced the risks associated with anaesthesia. Risks include noisy breaths due to blockage of the upper airways (stertor), laboured breathing and cyanosis, a bluish discoloration caused by a lack of oxygen in the blood. Hewitt’s design meant more ether could be added to the inhaler during surgery without removing the mask from the patient’s face.