No single compound has been identified as a good predictor of odor sensation across situations in the field. Because of this, human panelists conduct odor measurements and quantify odor intensity and unpleasantness.Manure sniffer-and-ranker! My future author-bio could put all those bricklaying, fish-gutting, sex-working writers to shame.
Based on psychological tests, seven primary classes of olfactory stimulants have been found to preferentially excite separate olfactory cells. These classes are: 1) ethereal, 2) camphoraceous, 3) musky, 4) floral, 5) minty, 6) pungent, and 7) putrid.
Ethereal in this case refers to Ethylene Dichloride (which the EPA says has a "pleasant chloroform-like odor"), but it's more magical to think of it as that heavenly part of the cow poop. Dirt to dirt and all of that.