This episode takes place in 1896.
During the station shift change, Chief Breckenridge holds up a color mug shot of a man he wants found. Color photography wasn't available until 1935.
When we first see Murdoch in bed, being treated by Dr. Ogden, she is injecting him with Mercury to presumably prevent infection. The introduction of mercury (sublimate solution) by means of intravenous injections was actually first recommended by Bacelli in 1892, though other drugs had been administered in this way several years earlier. Mercury was also a remedy of choice for syphilis in Protestant Europe even though it was regarded by some, as dangerous. Even after being included in vaccines for decades it has since been removed to prevent mercury poisoning