"Don't buy a barrel of oil," the broker said. "It'll kill you."

Oil may be king of the commodities, but its physical form is tough to come by for a retail investor. Mom and pop can buy gold and silver. They can gather aluminum cans, grow soybeans, and strip copper wiring, if they choose, but oil remains elusive -- and for very good reason. Oil, as I would soon discover, is practically useless in its unrefined form. It is also highly toxic, very difficult to store, and it smells bad. [...]

"Could a barrel of crude really kill me?" I asked a petrochemical engineer captive to my persistent, doubtlessly annoying questions. It absolutely can, he said. Hydrogen sulfide gas -- H2S, for short -- has a terrible propensity to evaporate from crude, knock out your olfactory capabilities, and slowly suffocate you to death. [...] "If you inhale ethyl alcohol vapors in a concentration of 1,000 ppm (0.1 percent by volume) for eight hours, you may get drunk. If you inhale hydrogen sulfide in a concentration of 1,000 ppm (0.1 percent by volume) for only a few seconds, you will be dead." [...]

"That [is] all good and well until you learn it's not Bakken but Kurdish oil, under strict embargo. Well done [for] supporting ISIS," the consultant replied by e-mail. Adding insult, the consultant informed me that the glass bottle was worth more than the oil inside it, anyway.

Previously, previously, previously.