When was oil discovered to be of biological origin?
If you look at a gas or liquid chromatogram of crude oil, you see a remarkable preponderance of (unbranched) even-numbered carbon compounds (re acetyl CoA homologation).  You also see traces of polycyclics that are net chiral - terpenoids, terpenes, pristane, phytane, cholestane, chlorins, and porphyrins.  Fischer-Tropsch gives a very different distribution and no net chirality.

Mikhailo V. Lomonosov, "Slovo o reshdenii metallov ot tryaseniya zemli" 
Proceedings of the Imperial Academy of Sciences, St. Petersburg, 1757.

(Mikhail Tsvet was born in 1872)