On 7 April,1853, Dr John Snow administered chloroform during labour to Queen Victoria for the birth of Prince Leopold: The inhalation lasted fifty three minutes. The chloroform was given on a handkerchief
in fifteen minim doses, and the Queen expressed herself as greatly relieved by the administration.
It was not, however revealed to the public that the Queen had received chloroform. This may have been because her medical advisors disapproved of chloroform and that it was used only on the insistance of the Queen. It is said that Her Majesty declared 'It is we who are having the baby; and we will have chloroform!'.
The figure on the right shows a John Snow Chloroform inhaler from 1858.
Diagram to show how nitrous oxide reaches the brain. Note that the concentration rises quite quickly but there is still some time lag in reaching the maximum concentration - because the gas is diluted by the blood and is also taken up by other tissues. Hence the importance of starting to breathe gas from the very beginning of a contraction if it is to have optimal effect. This is obviously beneficial because it means that it takes effect quickly. Likewise, once the face mask is removed, the gas is eliminated from the body equally quickly. This relationship is shown in the graph below
