Sir Frederick William Hewitt was a great advocate of nitrous oxide anaesthesia, mainly for short procedures. In 1885, he reviewed the methods of administration and concluded that accurately fitting valves were essential at the commencement of the inhalation, in order to ensure the rapid washout of air from the lungs; and there was a distinct advantage in allowing some rebreathing of nitrous oxide towards the end of inhalation. He thus devised the stopcock. The stopcock consists of a cylinder with two rotating sleeves and two rubber flap valves. The arrangement allows air to be breathed either through the valves or rebreathed to and from the bag; nitrous oxide to be breathed either through the valves from the bag and out to the atmosphere or rebreathed to and from the bag. Soon after the introduction of this stopcock, there was an increased interest in administering oxygen in combination with nitrous oxide.Amber coloured ether inhaler, with leather mask, celluloid shield and inflatable cushion with attached Hewitt's stopcock.hewitt, stopcock, celluloid, ether, inhaler, mask, rebreathing

This is a large metal framework covered in gauze, the whole mask completely enclosing the patient's face excluding any possibility of carbon dioxide being excreted. This object was found in the possession of the Italian Army in Libya in 1940, and donated to the museum by Dr Geoffrey Kaye. Gustave Julliard, of Geneva, after a death from chloroform had occurred in his practice, abandoned the use of that anaesthetic and adopted ether. He administered it from a large, wire frame, the outside of which was covered with waxed cloth to make it impermeable to air, the inside with surgical gauze on to which the ether was poured. Large metal wire frame mask, covered in waxed paper, with gauze wrapped around the rim to prevent ether leaking out, effectively forming a rebreathing apparatus.ether, carbon dioxide, italian army, libya, 1940

Black and white photograph of a drawing of a portable drawover apparatus. There are two vaporisers with metal valves, one made of glass, connected to the ends of two corrugated tubes which are connected to a face mask at the other ends. A small rebreathing bag is connected to the underside of one of the vaporisers.Handwritten in black ink on surface of photograph the letters A - H, J, labelling each part of the apparatus.drawover apparatus, vaporiser, anaesthetic apparatus

In 1896 Robert James Probyn-Williams was appointed first honorary anaesthetist to the London Hospital and joined a select band of fulltime anaesthetists (26) in Great Britain. The Probyn Williams inhaler was a further modification of the Clover inhaler with narrow airways and rebreathing. The metal inhaler is ovoid shaped. The rotating gauge has a series of numbers engraved onto the inhaler for measurement. There is an elbow joint leading to a connector for attaching a re-breather bag, and at the other end is tap-style mechanism. There is a small glass bulb encased in a metal housing. The facemask is completely made of metal as well.Stamped into handle of tap: COEXTER & SONjoseph clover, frederick hewitt, robert probyn williams

In 1896 Robert James Probyn-Williams was appointed first honorary anaesthetist to the London Hospital and joined a select band of fulltime anaesthetists (26) in Great Britain. The Probyn Williams inhaler was a further modification of the Clover inhaler with narrow airways and rebreathing.Ovoid shaped metal ether inhaler device with a dark brown leather fask mask attached.Moulded into inhaler: MAYER & MELTZER / LONDON

The Renton circle valve absorber has been sectioned to show the valve connection points. The inside is a creamy brown colour, encased in black on the outside. A larger silver metal valve runs through the centre, and to it attaches a flat, reflective silver metal disc as a dial indicating "EXH", "ABS", and "REB", with a black needle. The system includes tubes and valves for oxygen entry, gas expiration, connection to soda lime cannister, rotary valve, and rebreather bag, with a broken, deteriorated segment of the bag still attached.valve, anaesthesia, soda lime, rebreathing

A Weller-Ash nitrous oxide apparatus that has been sectioned, complete with a brown fabric Cattlin's rebreather bag, stopcock, rubber tubing, and celluloid mask, on an iron stand that has been decorated with a natural, gold-coloured leaf motif. The base of the stand is black, and has a brown foot pedal which controlled gas flow to fill the bag. Much of the stand and the dials on either side are a brassy gold colour.nitrous oxide, rebreathing, anaesthesia, dentistry, surgery

The apparatus sits on a four-legged stand with castors. There is a fabric mesh bag affixed to the top of the apparatus which hangs down half the length of the stand. There are two metal arms protruding out from halfway down the length of the stand; one of the arms has a rubber tube attached to it and the other has a fine braided rope, both of which connect to the top of the apparatus. The top of the apparatus has been sectioned.anaesthesia, rebreathing, carbon dioxide, ether, oxygen

Black and white photograph of anaesthetic apparatus inside a portable case which is standing upright and open. Inside the right half of the case is a flowmeter connected to several rubber tubes and a small Vinyl Ether vaporiser with a lever switched to ON. The left half of the case has four shelves with equipment on each shelf. The top shelf has an oropharyngeal airway tube. The second shelf has a metal facemask inhaler and a glass vaporiser. The third and fourth shelves hold metal cylindrical inhalers. In front of the case is a metal inhaler with face mask, attached to a rebreathing bag.Handwritten in grey pencil on reverse: Fig 17 new bookanaesthetic equipment, portable case, flowmeter, inhaler, vinyl ether

The Coxeter-Mushin carbon dioxide absorber consists of the main metal body, painted aquamarine, fixed to a stand. The cylindrical silver metal cannister on the left was used to contain ether, while that on the right contained soda lime. The apparatus has been sectioned to show the inside of the two cannisters, the right of which has an arrow drawn inside to indicate the flow of air breathed out by a patient. The front cover over the control dials has also been removed to show the mechanism. The two circular holes above the dials, facing forward, are where two corrugated tubes would attach; both of these tubes attached to the mask of the patient. The round yellow knob in the centre controls the Compensating Valve, which allowed the anaesthetist to raise or lower the rebreathing bag to allow air into the circuit or expel anaesthetic gas.anaesthesia, carbon dioxide, ether, soda lime