'Walton Minnit' Gas and Air apparatus, London, England, 1932-1942

1936-1950 in London

Buy this image as a print 

License this image for commercial use at Science and Society Picture Library

Science Museum Group Collection
© The Board of Trustees of the Science Museum

Portable "Walton Minnitt" apparatus for nitrous oxide and air analgesia, by Coxeter, 1936-1950

R J Minnit (1889-1974), with the help of Arthur Charles King (1888-1965), developed a modification of an existing anaesthetic apparatus to replace chloroform as a pain reliever for mothers during childbirth. Once the potentially toxic nature of chloroform had become apparent, it was used far more cautiously.

In this device, nitrous oxide fills the rubber bag underneath the glass, which as it expands lifts the metal plate to close off the supply of gas. As the patient inhales through the mask, the nitrous oxide is mixed with air. The portable box was designed so mothers could self-administer the gas and air. Gas and air are still used today. This model is known as the ‘Walton-Minnit’ and was first sold in 1936.

Related people


Object Number:
apparatus, metal, apparatus, rubber, case, glass and case, wood
anaesthetic machine
  • furnishing and equipment
  • tools & equipment
Hypher, T.J.

Cite this page


We encourage the use and reuse of our collection data.

Data in the title, made, maker and details fields are released under Creative Commons Zero

Descriptions and all other text content are licensed under a Creative Commons Attribution 4.0 licence

Using our data


Download catalogue entry as json

View manifest in IIIF viewer

Add to Animal Crossing Art Generator

Download manifest IIIF

Our records are constantly being enhanced and improved, but please note that we cannot guarantee the accuracy of any information shown on this website.