When Murdoch builds a two story diorama of the Jenkins mansion with chess pieces to simulate the suspects, Crabtree remarks that it would make a great board game, an obvious reference to the as yet non-existent game of "Cluedo." The game was originally invented to while away the time in the bomb shelters during the Battle of Britain. Anthony E. Pratt applied for a patent for the game, which was originally called "Murder." When the game was sold to Waddingtons, the name was changed to "Cluedo" ("Clue" in the US) and was released in 1949, fifty years after Crabtree's inspiration. Pratt's original playing rules called for ten players, the number of suspects that Murdoch has represented by chess pieces.
Dr. Ogden uses Jell-o to make a mold of a wound and explains to Murdoch, who is unfamiliar with it, that it's all the rage in Buffalo. Gelatin is manufactured from collagen extracted from boiled bones and animal by-products such as connective tissue and was used to make desserts in since the 15th Century. Gelatin became popular Victorian era when it was presented in attractive molds, but it was used more for its eye appeal than its taste. Because it was time-consuming and costly to make, it was almost exclusively used by the upper classes. However in 1845, a patent for powdered gelatin was obtained by industrialist Peter Cooper. This powdered gelatin was easy to manufacture, easier to use in cooking, and relatively inexpensive. In 1897, in LeRoy, New York, carpenter and cough syrup manufacturer, Pearle Bixby Wait trademarked a gelatin dessert, called Jell-O. He and his wife May added strawberry, raspberry, orange and lemon flavoring to granulated gelatin and sugar. The formula was sold to the Genesee Pure Food Company, which marketed it under the eponymous Jell-o brand name, evidently coinciding with Dr. Ogden's use of it in making a mold of the wound.
At about 17:55, a blackboard in the morgue shows Maxwell's equations governing electromagnetism. High level physics in those days, and a strange topic for a medical examiner.
This episode takes place in 1898.