Hayes St Leger, 4th Viscount Doneraile (1 October 1818 – 26 August 1887) was a member of the Peerage of Ireland who was an Irish representative peer in the British House of Lords between 1855 and his death.
[2] Their daughter Emily Ursula Clare St Leger married Bernard FitzPatrick, later 2nd Baron Castletown; their other children, Hayes and May, died as infants in 1852 and 1867.
[9] At the urging of his son-in-law, Castletown, Doneraile and Barrer travelled to the Pasteur Institute in Paris to receive an experimental post-exposure vaccine.
Doneraile's doubts over the vaccine's risk caused him to vacillate further before allowing Jacques-Joseph Grancher to administer two doses, on 24 January and 21 February.
[15] Pasteur in the British Medical Journal blamed its failure on the delay in starting and the fact that Doneraile accepted only a "simple treatment" rather than the recommended "intensive course".