Robert Tetro patented this gadget in 1930 to help prohibition-era enforcement agents surreptitiously take drink samples from establishments suspected of selling alcohol. It consisted of a tube that was clipped onto a drinking glass, and a rubber bulb that could be squeezed to suck a sample of the drink for analysis.
I'll bet the agents never actually used it. They probably just got drunk at a bar, then asked the speakeasy owner for hush money. If refused, they'd stagger into their car, use the bulb to draw some hootch from their hip pocket flask and give it to the boys in the lab.