Eureka (word)
The exclamation 'Eureka!' is attributed to the ancient Greek scholar Archimedes. He reportedly proclaimed "Eureka! Eureka!" after he had stepped into a bath and noticed that the water level rose, whereupon he suddenly understood that the volume of water displaced must be equal to the volume of the part of his body he had submerged. (This relation is "not" what is known as Archimedes' principle—that deals with the "upthrust" experienced by a body immersed in a fluid.) He then realized that the volume of irregular objects could be measured with precision, a previously intractable problem. He is said to have been so eager to share his discovery that he leapt out of his bathtub and ran naked through the streets of Syracuse.
Birch
"Betula" species are organised into five subgenera.
"Note: many American texts have "B. pendula" and "B. pubescens" confused, though they are distinct species with different chromosome numbers."The common name "birch" comes from Old English "birce", "bierce", from Proto-Germanic *"berk-jōn" (cf. German "Birke", West Frisian "bjirk"), an adjectival formation from *"berkōn" (cf. Dutch "berk", Low German "Bark", Danish "birk", Norwegian "bjørk"), itself from the Proto-Indo-European root *"bʰerHǵ-" ~ "bʰrHǵ"-, which also gave Lithuanian "béržas", Latvian "Bērzs", Russian "beréza", Ukrainian "beréza", Albanian "bredh" ‘fir’, Ossetian "bærz(æ)", Sanskrit "bhurja", Polish "brzoza", Latin "fraxinus" ‘ash (tree)’. This root is presumably derived from *"bʰreh₁ǵ-" ‘to shine’, in reference to the birch's white bark. The Proto-Germanic rune "berkanan" is named after the birch.