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Dictionary of National Biography, volume 37, p 167 - "Returning to England at the close of 1854, Mayne was made a brevet-colonel and A.D.C. to the queen. He had just returned to India when a violent attack of dysentery sent him home again. He died at Cairo, 23 Dec. 1855."
"Death on a Pale Horse" http://www.britishempire.co.uk/article/palehorse.htm
Hardwicke's Annual Biography for 1856 , p176-177.
Annual Register 1855, p 330
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