I decided to test the eggs I just got and that had an embryo in one. I did the Float Test with the remaining 16 out of the initial 24.
-3 floated so I threw them out
-2 were starting to stand on their ends and were at a 45° angle
-11 stood on their ends but did not float
When my friend (Linda) gave them to me, she told me that the chicken owner had them in her fridge. I kinda got suspicious because that's not happened before, and I figured that they were getting old or she found them in the yard and was not sure how long they are been there. I'm gonna see Linda at a church Homecoming on Sunday. I'll have her get me another 2 dozen eggs and ask her neighbor to make sure they're fresh...then I'll test them (I've never done this before.)
Linda told me that the woman has 100 chickens and gives her eggs away through various local organizations, so I'm not surprised she has some stale inventory. If this doesn't work out, I got a couple of backup sources.