Complex sentence: In 1710, Hauksbee, who called it the "ratio of refraction", wrote it as a ratio with a fixed numerator, like "10000 to 7451.9" (human urin).
Split into simpler sentences: In 1710, Hauksbee called it the "ratio of refraction". He wrote its value as a ratio with a fixed numerator, like "10000 to 7451.9" (human urin).