This is some laboratory glassware used in Pasteur’s experiments, as illustrated in Les merveilles de l’industrie, an 1873 science book that has a marvelous gallery on Flickr.
It’s a “sinuous-neck flask employed by M. Pasteur in his experiments against spontaneous generation” – in other words, a device used to prove that germs did things, that microbes caused decay rather than mold and maggots spontaneously springing forth from materials.
What Pasteur did was boil some beef broth inside the bottle with the neck arranged so that particles from the air couldn’t fall inside. The stuff didn’t go bad right away. When he tilted it so particles could fall in, the stuff went off. Something in the air was causing it – spores, microbes, the things we now know cause disease and decay.