After the word protoplasm was coined in the mid-19th century for the jellylike material that is the main substance of a cell, it began to be used widely, especially by scientists and others who imagined that the first life-forms must have arisen out of a great seething protoplasmic soup. Since protoplasm includes all the cell's living material, inside and outside the nucleus, it is a less useful scientific word today than more precise terms such as cytoplasm, which refers only to the living material outside the nucleus. But many remain fascinated by the image of that soup bubbling away as the lightning flashes and the volcanoes erupt.