In article ,
says...
It depends on the size of the dropper and the hole in it. Different
droppers have different size drops.

Not according to my little black book (No, not that one, Glover's Pocket
Ref).

And yes, it's a US teaspoon :-).

BTW, that's a great little book. Got it filed right next to the
"Standard Mathmatical Tables from the Journal of Chemistry and Physics"
which unfortunately is out of print.

--
Homo sapiens is a goal, not a description