It is not known exactly when humankind first used petroleum. It is known, however, that ancient peoples worshipped sacred fires that were fuelled by natural gas seeping to the surface through pores and cracks. It is also known that asphalt, a very viscous form of petroleum, was used to waterproof boats and heat homes as early as 6,000 BC. Asphalt was also used as an embalming agent for mummies …