Old building washbasin has an extra "outlet". What is that?

Hello

I need some help with my sink connections.

A few weeks ago, I moved into an old Art Nouveau house of my great-aunt and want to renovate the bathroom here, or rather refurbish what is necessary.

The sink has an extra outlet/connection etc. that hangs just above the sink and used to drip into the sink from time to time, I think... because the sink is quite corroded at that spot. (See pictures)
I have already searched half of Google, but nowhere did I find information about such a construction...
My question therefore is... what kind of part is that, what function does it have, and can it be removed/converted relatively cheaply so that I can then install a "normal sink on the wall" and the function of this outlet basically disappears into the wall? ...or at least where it is not in the way and also does not ruin the sink... if this part has a certain necessary function...

I am really very grateful for any help!
Best regards

That could be a cold water connection for a boiling water device. People used to have those above the sink or in the kitchen above the sink for warm water. I also know it from earlier times.

Could for example have been used as a connection for a shower hose or to fill cleaning buckets. Since it seems that a tankless water heater was used here, the filling connection for cleaning buckets or washing machines is likely. Since the tiles will probably be replaced anyway, it should not be a problem to remove the connection.

I have so far (rarely) seen such things more often on bathtubs, mostly in bathrooms from the late 60s. To my knowledge, these are vents for the drainpipes to avoid pressure problems caused by standing columns of air. So absolutely no inflow, and only in rare cases affected by wastewater rising that high. To then divert this quasi reflux again, water flowing out runs over the tub or the sink via their drain, hence the shortest possible path to the regular drain, near which they are installed somewhat higher. Presumably, later on pipe systems were designed more cleverly because they are apparently obsolete in newer installations. Ask an older plumber.

On which floor is the bathroom?

At my boss's place, something like that was in the top bathroom in the 80s and was a heating overflow.

But it would only work for you if this were basically the highest heating point in the house...