When was oil discovered to be of biological origin? Is there an article, book, some account of the discovery that crude oil came from decayed biological material?
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)