In the Bible, Abraham attempted to sacrifice his son Isaac, but the sacrifice was halted by God.
Frankenstein by Mary Shelley (1797-1851) was published in 1818 (Lackington, Hughes, Harding, Mavor & Jones).
Nobility was never placed in asylums. For the purpose of the novel, and in order to dramatize Berd’s situation, artistic licence was taken.
The Strange Case of Dr Jekyll and Mr Hyde by Robert Louis Stevenson (1850-1894) was published in 1886 (Longmans, Green & Co.) so theoretically Berd should not have been aware of the novel.
Alice’s Adventures in Wonderland by Lewis Carroll (1832-1898) was published in 1865 (MacMillan)