"Shale oil, produced at Rifle, Colorado, by the Bureau of Mines through NTU retorting of oil shale, has been examined by a combination of the following techniques: distillation, extraction with a solution consisting of a metal chloride dissolved in concentrated hydrochloric acid, silica-gel percolation, extraction with urea, and infrared spectrometry. Hydrocarbons constitute 39% of the shale oil, and compounds of nitrogen, sulfur, and oxygen account for the remaining 61%. The hydrocarbons are 6% normal paraffin, 6% normal olefins, 5% isoparaffins plus naphthenes, 12% isoolefins plus cycloolefins, 4% monocyclic aromatics, and 6% polycyclic aromatics. The non-hydrocarbons are 36% nitrogen compounds, 6% sulfur compounds, and 19% oxygen compounds. The composition data suggest that some hydrocarbons are formed during retorting of oil shale via the steps: kerogen--) nitrogen compounds--)isoparaffins plus naphthenes --)isoolefins plus cycloolefins --)aromatics."