This thing is massive. It stands 30 inches. The neck alone is 12+ inches long , with a radius of  9 1/2 inches. It weights a just shy of 30lbs. And half inch thick. I've been told it's ether Demijon or a very large and rare pharm mixing bottle

There is no embossing or writing on the piece which lead me to believe its early pyrex. Possibly French. There are very few small bubbles throughout and no seam lines to speak of.

The neck of the bottle ( in my opinion) is what makes it very rare. Most were broken r off. I have looked and researched for days and haven't found another one like it, not even close. As shown in the pictures the very top of the bottle is cleanly sheared off which also leads me to believe its supposed to be like that. Other than that this piece is flawless .