Question for "B" Carb expert

[Russ/40]

The below are taken of a "B" carb. I am trying to determine the purpose and nature of the small brass object seen both in the venturi shot and the external shot. Is this part of the idle circuit? both ends of the same object are shown, and I am trying to determine if there should be a patent connection. I have not been able to get any fluids to pass through.