Glass was often the preferred material for storing expensive oils, perfumes, and medicines in antiquity because it was not porous. The small body and mouth allowed the user to carefully pour and control the amount of liquid dispensed. By the 1st century AD, the technique of glass-blowing had revolutionised the art of glass-making, allowing for the production of small medicine, incense, and perfume containers in new forms. Glass vessels are found frequently at Hellenistic and Roman sites, especially in cemeteries, and the liquids, which filled them, would have been gathered from all corners of the expansive Roman Empire.
To learn more about Roman glass, visit our relevant post: How It Was Made: Roman Glass.