The girls are enrolled in the Tepes School for Girls. Vlad (the Impaler) Tepes of Wallachia is the historical foundation for the fictional Dracula.
Attempts at animal to human blood transfusions date back to the 17th Century. The first human to human transfusions were attempted in the early 19th Century, and the first successful attempt to use transfusions for hemophilia was done in 1840, but most attempts were unsuccessful until blood type differences were discovered in 1901 with the first successful transfusion based on matched blood type followed in 1906.
School girl sisters Olivia and Dorothy Cornell are played by real-life sisters Vivian Endicott-Douglas and Hannah Endicott-Douglas.
This episode takes place in 1898.