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.
No one is quite sure how lead got its name. The word has been traced to manuscripts that date to before the 12th century. Romans called the metal plumbum. It is from this name that the element's chemical symbol comes: Pb. Compounds of lead are sometimes called by this old name, such as plumbous chloride.