2512: serology and truth serums Oct 28, 2021

Serology is the study of blood, and especially pathogens in blood, but its etymology has nothing to do with that really. In Latin, 'serum'—which also led to the the English word 'serum'—which meant 'whey'. Blood has little to do with milky water, and what's more, this is related to other milky terms like Sanskrit सारण (sāraṇa) for 'buttermilk' and Ancient Greek ὁρός (horós) 'whey; curd'. This makes sense for the English 'serum', as this is a yellowish-liquid that's a component of blood. That said, 'serum' as in 'truth serum', while informal, is still a divergence from the original, presumably by association with injections generally. The association with blood in general is also an extension of the specificity of 'serum'.