I was at a friend’s today and he pulled out an item he recovered from his dad’s office after dad died. It was a medical office, the private practice of an internist who became a physician in 1942 and practiced until some time in the 1970s.
The item in question is a wooden case with a hinged top with a metal clasp, approximate H x W x D being 6" x 3" x 1" and tapered slightly towards the top. Inside are two holes running almost the length of the thing that encase two glass tubes that are sealed and nippled at the top. One tube is ~2/3 filled with a clear liquid and the other is similarly filled with a dark amber liquid. Both liquids appear to have a viscosity similar to that of water (not rigorously checked, but neither was syrupy).
The tubes look like standards for an old colorimeter.
The pictures in the link are all for fancy setups, but at its simplest, a colorimeter can be nothing more test tube rack of standard colors for your reaction, and a light to compare them with your sample tubes.
I was going to say that perhaps these were reagents for simple blood or tissue screens done by the physician at the office, but Squink may be closer to the mark. Were the tubes or case labeled in any way?
It was used for titrations, but also for +/- type tests. Back in high school I got a job helping to clear out the analytical lab at an old county nursing home. They had dozens of cases containing standards like you pictured. Some consisted of just a couple sealed tubes, others came in sets of a dozen or more in carefully gradiated colors. Microwell plates have pretty much replaced test tubes in the medical lab, and spectrophotometers have mostly replaced eyeball driven colorimetery. Still, home pregnancy tests, with their little colored +/- indicators, are a distant cousin of these earlier visual methods.
There’s no telling exactly what assay your tubes were used in, but typically such pairs consisted of a positive and a negative standard.