An atomizer is a device that allows for the application of a medication in a spray of tiny droplets. They would be used to dissolve cocaine in an oil base as an anesthetic to both numb and coat the nasal cavity and throat, which was a common treatment in the late 19th century. The design of the atomizer was later adapter for use as perfume bottles and spray guns for fine paint application.
This glass atomizer bottle has the original rubber bulb used to apply pressure, and the Defender brand name stamped into the glass. This design would have likely been used sometime between 1887 and 1950, but the idea of such a product is still used in select medical situations today, though much less frequently.
The less frequent use of these products may be explained by the products warning: “Caution: When spraying the nose keep mouth open to avoid undue pressure. Do not spray excessive quantities of solution, and do not use an atomizer over long periods except under your physicians supervision.”