Have no idea what this box-on-legs is!

Old sterilisers, here, are basically enamel boilers with lids.

 

I think OBB suggestion of a dough box is most likely. The sloping sides on the liner makes that likely; classic dough box shape.

The pedal is strange; seems it would be easier to just remove the lid. But punching dough is easier done from above so a dough box resting on a table top would be too high (see last pic). So maybe move this to the floor and use pedal to raise lid so it can be punched down while sitting?

OP's made in early 20th century when enamel steel for hygiene was the new rage; previously dough boxes would have been just wood. (I have an earlier period Windsor dough trough with no lid).
http://www.homethingspast.com/dough-box-kneading-trough/

 

@PRB I'm in Santa Cruz... now you have me wondering what that is ! I have a lot of the late 1800's sears and wards repro catalogs...... I may have to start looking ! My thought was foot soaker but too small...... some sort of waste disposal is my guess, like for gauze, cotton in a doctors or dentist office.... was the back story of how you found it ???

 

Hi, @Firemandk! A neighbor whose mother died (the mother was a furniture finisher) asked me to come over and take any furniture pieces I might want. My house is small and I had virtually no room for anything, but I took this because I loved it so much! My neighbor has no idea what it was used for, and I've been so curious!

 

@PRB Hopefully we can get to the bottom of it .... there are Medical Catalogs online in the google book search , wish I could look right now but they are replacing the back fence in my mobile home park which meant I had to move my wood covered pump fountain ( which of course fell apart ) as well as an above ground wood planter with a Mock orange ( which of course fell apart ), so since I have lived here since 1986, and rebuilt them at least 4 times, I need to go find a huge pot ......wish me luck in my search tomorrow ....we have "pottery planet" here around the corner but I bet I am going to have to drop a $100 bill for a big enough pot !!!

 

@PRB as far as a nursery cooler , I actually have one from 1905, it is all metal like an old rectangular ice chest , it has a section for milk, a section for ice , an outside brass, nickle platted 1/4 turn valve, painted light green, wire handles, and for all purposes it looks exactly like an early ice chest, which is what I bought it for, as I have a 1919 copy camp trailer and a 1926 Model T Speedster..... found out what is really was using the old Sears catalogs.....