I was at an antique and bric-a-brac store, and I found several pieces of glassware. They were pretty cheap, so I purchased some of the more interesting ones. Among them were a few somewhat strange "bulbous test tubes". I purchased 2 of them, and on sale for $2.50 each.(the blue line means half off).
After looking up "kimax 47121" I found an amazon listing for some, labeled as a "blood sugar tube". I could not find anything else besides this. Are they particularly useful, for anything besides stuff relating blood sugar? How are they used? Can I heat them without fear of it breaking? Would they be worth trying to sell if I cannot use them?
Answers to any of these questions would be great.