Classic XKCD Web Comic #282: Organic Fuel (described)

A web comic of romance, sarcasm, math, and language.

Scene: Drawing of a stick figure sitting at desk with a computer. Another stick figure is standing nearby.
Figure at Computer: Wow – Engines can burn vegetable oil.
Standing Figure: Well, sure. You can burn most any organic matter. Corn, leaves, spices…
Figure at Computer: Spices? Really?
Standing Figure: Sure – Mussolini made the trains run on thyme.
Figure at Computer: …
Figure at Computer: We are no longer friends.

Hover text: I have nothing to apologize for.

Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors).

Comic by xkcd.com. Described by BlindGadget under the Creative Commons license.