If you've noticed that your car has thick smoke coming out of the exhaust pipe, it may be a sign that your engine needs some attention. Just like you can examine an animal's stool to get an idea of its health, you can pay attention to the quality of your car's exhaust to get an idea of what's going on inside the engine.
The word sulfur has old roots. It comes from the ancient Latin word for sulfur, sulpur, which later changed to sulphur, perhaps under the influence of the Arabic word for yellow, sufra.
Perhaps this is why many people of previous centuries associated sulphur (also known as brimstone) with the unpleasant afterlife known as Hell. In the New Testament, Hell is described as a lake that burns with fire and brimstone.