orange oil

I knew that orange oil exists - it is marketed in a variety of products. I never really thought about it, though. I was just standing over the sink pealing an orange and noticed that little anti-puddles appeared in the skim of water on the sink surface. Another section of peal pulled off, another spate of little circles. I looked more carefully and could see that not only do oil and water not mix in that context, but that the rainbow affect one gets from motor oil on wet pavement holds true for orange oil on wet steel. Cool.

grateful to be a native speaker of English

I was watching videos of the empty can/full can test for supraspinatus problems (no actual cans are involved. They are imaginary cans). I thought this one was good, but it seems to me that empty and can are regular words, not jargon terms - why do they still use the English words? This wasn't the only example. I guess for people who don't know any English, it's just like the tests that are named for the folks who invented them (or first described them in the literature).
http://www.youtube.com/watch?v=a7itYGBCwWo