A nickel plated hypodermic syringe which would have been used for the administration of opiates.
The case reveals a hypodermic syringe with a metal plunger and solid metal barrel. The hypodermic needle (with a central wire to maintain patency) screws into the top of the plunger, which is marked Down Bros as is the outer casing. There is a safety pin on the casing allowing the syringe to be attached to a medical or nurses uniform. Down Bros were in business since 1874. The safety pin was invented in 1849.