Clover chloroform inhaler with case lacking lid, by Coxeter, London, 1862-1894

Joseph Thomas Clover (1825-1882) invented this inhaler, which was used for chloroform anaesthesia, in 1862. This inhaler was never popular despite Clover demonstrating its successful use for regulating dosage – incorrect doses of chloroform proved to be lethal.

Inhaling the fumes of anaesthetic was the preferred way of numbing the patient to perform painful surgical procedures. Using a syringe, 2.4 ml of liquid chloroform was injected into the chamber then heated by a vaporizer, which was attached to bellows that could pump sixteen litres of air at a time. This created a concentration of 4.5 per cent chloroform in air, enough to anaesthetise a patient within four minutes. The mixture filled a waterproof silk bag which was placed on the anaesthetist’s back so he could move around easily. The patient breathed in the vapour through a face mask.